IMPROVE II Status Report

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December 14 2 PM IMPROVE II PROJECT UPDATE

    At the 1 PM meeting today an IOP was called for tomorrow (Saturday).  A warm front will move through the study area around noon, followed by a moist southwesterly flow and considerable orographic precipitation.

Closed door time for the aircraft will be 11 AM.  The P3 should plan on a full duration flight at this point and the Convair should plan on one flight.

Ice crystal observers should be in place from 1 PM through 9 PM.  Freezing levels will be hightso it might be time to hit the Hoodoo chair again.

The SPOL should be turned asap into unmanned mode and be left on through today and tomorrow.

IMPROVE soundings should be planned for 21, 00, and 03 UTC.

There is good chance of another IOP on Sunday.  Only about one week left!

The next update will be at 9 PM tonight.

December 13 9 PM IMPROVE II PROJECT UPDATE

    Today's IOP will be completed within the next 1-2 hours.

    Friday will be a down day for aircraft, ice crystal observers, and radiosonde launches.  The SPOL should continue in unmanned operation.  Bob Houze can make further adjustments to the SPOL scheduling

Saturday looks promising for the next IOP.

A meeting will take place tomorrow at 1 PM with an update at 2 PM tomorrow.

December 13 10 AM IMPROVE II PROJECT UPDATE

        Today's IOP is on track and should be wonderful.  A very moist system has sped up and is now approaching the Oregon Coast.

    Closed door time for both aircraft remain 1 PM.  The P3 should be prepared for a full duration flight and the Convair will have a dual flight mission.

The Convair flight track will be southwest-northeast.

IMPROVE soundings should be taken at 21,  00,  03, and 06 UTC

Ice crystal observations should be taken from 1 PM  and 10 PM--although the freezing levels will be so high there probably won't be any ice to sample!

The spol should be on during the period.

Tomorrow--FRIDAY-- will be a hard down day for both aircraft.

An update will be available

December 12  9 PM IMPROVE II PROJECT UPDATE

    Today's IOP is  finishing up. The Convair is now completing its mission.  The P3, which was unable to fly today, should be back in line tomorrow.

    At today's 1 PM meeting an IOP was called for tomorrow afternoon and evening. A very wet system will come in later tomorrow afternoon and tomorrow evening...potentially one of the best IMPROVE IOPs.

    Closed door time for both aircraft remain 1 PM.  The P3 should be prepared for a full duration flight and the Convair may need to go on two flights..

The Convair flight track will be southwest-northeast.

IMPROVE soundings should be taken at 21,  00,  03, and 06 UTC

Ice crystal observations should be taken from 1 PM  and 10 PM--although the freezing levels will be so high there probably won't be any ice to sample!

The spol should be on during the period.

An update will be available at 10 AM tomorrow morning.

December 12  2 PM IMPROVE II PROJECT UPDATE

    An IOP is occurring today.  The warm front is through and there will be a break in the precipitation until approximately 4-5 PM.  Both aircraft should depart at 3 PM (7-7.5 h for P3),  single duration flight for the convair.

The Convair flight track will be east-west.

IMPROVE soundings should be taken at 21,  00,  03, and 06 UTC

Ice crystal observations should be taken from 1 PM  and 9 PM

The spol should be on during the period.

Tomorrow, a very wet system is forecast to move through the area--or so the models indicate.  At the 1 PM meeting today, an IOP was called for tomorrow.

Both aircraft will participate with a closed door time of 1 PM.  Except an extended duration flight of the P3 and single flight of the Convair.

IMPROVE soundings should be taken at 21, 00, 03, and 06 UTC
Ice crystal observers from 2 PM until 10 PM
SPOL should be on.

An update will be available at 9:00 PM tonight.

December 12  12:30 PM IMPROVE II PROJECT UPDATE

    An IOP is occurring today.  The warm front is through and there will be a break in the precipitation until approximately 4-5 PM.  Both aircraft should depart at 3 PM (7-7.5 h for P3),  single duration flight for the convair.

The Convair flight track will be east-west.

IMPROVE soundings should be taken at 21,  00,  03, and 06 UTC

Ice crystal observations should be taken from 1 PM  and 9 PM

The spol should be on during the period.

The next update will be at 2:30 PM.

December 11  9 PM IMPROVE II PROJECT UPDATE

    An IOP has been called for tomorrow (Wednesday).  A warm front will be moving eastward through the study area between noon  and 2 PM tomorrow, followed  by a vigorous cold front a few hours later.  Substantial orographic precipitation is expected tomorrow night.  Late Thursday also looks excellent.

Both the P3 and Convair will be flying.  The P3 should prepare for a maximum duration flight and the Convair should prepared  for dual flights.

Closed door time for both planes  has been changed to 12 noon and may be delayed for an hour or two.

The Convair flight track will be east-west.

IMPROVE soundings should be taken at 21,  00,  03, and 06 UTC

Ice crystal observations should be taken from 1 PM  and 9 PM

The spol should be on during the period.

The next update will be a 9 AM tomorrow.

December 11  2 PM IMPROVE II PROJECT UPDATE

    An IOP has been called for tomorrow (Wednesday).  A warm front will be moving eastward through the study area between 11 AM and 2 PM tomorrow, followed  by a vigorous cold front a few hours later.

Both the P3 and Convair will be flying.  The P3 should prepare for a maximum duration flight and the Convair should prepare for dual flights of 6 hr duration.

The Convair flight track will be east-west.

IMPROVE soundings should be taken at 18,  21,  00 and 03 UTC

Ice crystal observations should be taken from 11 AM through 8 PM

The spol should be on during the period.

The next update will be at 9 PM tonight.
 

December 10 9 PM IMPROVE II PROJECT UPDATE

    The aircraft portion of the IOP is cancelled for tomorrow.  The surface-based data collection will continue.

IMPROVE soundings should be taken at 18, and 21  and 00 UTC

Ice crystal observations should be taken from 11 AM through 6  PM

The spol should be on during the period.

December 10 2 PM IMPROVE II PROJECT UPDATE

    An IOP has been called for tomorrow (Tuesday).  A modest system will be moving southward through the study area tomorrow afternoon.  There is a  chance this IOP will be cancelled, so be sure to check the update tonight at 9 PM.

Only the P3 will be flying on Tuesday.  Prepare for a 7-h flight.

IMPROVE soundings should be taken at 18, and 21  and 00 UTC

Ice crystal observations should be taken from 10 AM through 6 PM

The spol should be on during the period.

The next update will be at 9 PM tonight.
 

December 9, 9 PM IMPROVE II PROJECT UPDATE

    The IOP for MONDAY has been CANCELLED.  An IOP is now being considered for Tuesday morning. Next update at 2 PM on Monday.
 

December 9, 2 PM IMPROVE II PROJECT UPDATE

    An IOP has been called for tomorrow (Monday).  A modest system will be moving southward through the study area tomorrow morning.  There is a significant chance this IOP will be cancelled, so be sure to check the update tonight at 9 PM.

Closed doors for both the Convair and P3 will be 7 AM.

This would be a single flight for the Convair and a roughtly 6 hour duration flight for the P3.

IMPROVE soundings should be taken at 15, 18, and 21 UTC

Ice crystal observations should be taken from 7 AM through 2 PM

The spol should be on survelliance mode by 3 AM (can be left unmanned overnight).

The next update will be at 9 PM tonight.  Remember, there is a significant chance this IOP will be cancelled, so keep tuned.

December 8, 6 AM IMPROVE II PROJECT UPDATE

    A cold front will pass through the study region during the day and we will attempt to observe all phases of its passage. The front has  recently passed 130W and its precipitation should reach the study area around 10 AM. Last night's timing seems realistic.

The closed door time for both the Convair and P3 will be 9 AM. .  This time may be delayed further to insure the study region is in precipitation when the aircraft get there.  The  P3 should be prepared for a full duration (9.5)  flight.  Convair may need two flights.

The Convair should be on the SW-NE track. At 700 mb, xpect sw (240) winds at 45 knots , followed by a transition to westerly winds at 35 knots between 2 and 3 PM.

The SPOL should be on survelliance mode no later than 6 AM

 IMPROVE soundings should be taken at 16, 18, 21,  00, and 03 z

Ice crystal observers should be in the field from 9AM to 8PM; however, with an initial high freezing level the opportunities for ice crystal evaluation will be limited during the first part of the IOP.

A further update will be made at 8:15 AM on the telephone message  to provide guidance for aircraft departure.

December 7, 9 PM IMPROVE II PROJECT UPDATE

    At the meeting at 1 PM an IOP was called for tommorrow (Saturday). A cold front will pass through the study region during the day and we will attempt to observe all phases of its passage.

The closed door time for both the Convair and P3 will be 9 AM.  (Two hours later than the 2 PM update).  This time may be delayed further to insure the study region is in precipitation when the aircraft get there.  The  P3 should be prepared for a full duration (9.5)  flight

The Convair should be on the SW-NE track.

The SPOL should be on survelliance mode no later than 6 AM

 IMPROVE soundings should be taken at 16, 18, 21,  00, and 03 z

Ice crystal observers should be in the field from 9AM to 8PM; however, with an initial high freezing level the opportunities for ice crystal evaluation will be limited during the first part of the IOP.

An update will be made at  6 AM tomorrow (Saturday) morning
 
 

December 7, 2 PM IMPROVE II PROJECT UPDATE

    At the meeting at 1 PM an IOP was called for tommorrow (Saturday). A cold front will pass through the study region during the day and we will attempt to observe all phases of its passage.

The closed door time for both the Convair and P3 will be 7 AM.  This time may be delayed a few hours to insure the study region is in precipitation when the aircraft get there.

The Convair will be on the SW-NE track.

The SPOL should be on survelliance mode no later than 6 AM

Additional IMPROVE soundings should be taken at 15, 18, 21, and 00 z

Ice crystal observers should be in the field from 8 AM to 6 PM; however, with an initial high freezing level the opportunities for ic crystal evaluation will be limited for the first part of the IOP.

An update will be made at 9 PM tonight.
 

December 5, 2 PM IMPROVE II PROJECT UPDATE

An IOP is  set tonight to begin 4 PM and will run through midnight..  A Pacific frontal system is rapidly approaching the coast, with rain spreading into the study area after 00z.

Soundings should be taken at 00, 03 and 06 UTC.

Ice crystal observers should begin at 00z or as soon as precipitation begin.  They can quit at 08z (midnight).

The availability of the Convair is not clear at this time.  If available, closed doors should occur at 5 PM for a full duration flight.

The sPol should run throughout the period.

There will be an update at 4:30 PM
 

December 5, 10 AM IMPROVE II PROJECT UPDATE

    An IOP is still set tonight, but the start time has been delayed until 4 PM.  There is considerable uncertainty about the timing of the system tonight--which hopefully will be resolved by early afternoon.  The P3 will not be available for tonight or tomorrow and the Convair is currently in Eugene after experiencing a failure of the air speed indicators. The convair may be available for tonight.

If the IOP goes forward tonight, it would run from 00z to 07-08z, with vertical soundings and ice crystal observations taken during that period.

An update will be available at 2 PM today.

December 4, 9 PM IMPROVE II PROJECT UPDATE

    An IOP has been set for later tomorrow afternoon and tomorrow evening.  A vigorous frontal zone will be
moving in during Wednedsay evening, with precipitation reaching the study area around dinner time.
There is some uncertainty about the exact timing of this system, but clearly the bulk of the IOP will be
during the evening.

At this time, a closed door time of 3 PM has been set for both the Convair and P3 to handle the
uncertainty...however, there is a good chance that aircraft departure time will be delayed. If the system is too late, the mission may have to be scrubbed.

A major question is the status of the Convair, which was forced to land in Eugene by the failure of both air speed indicators.

S-Pol should continue operations, but can be in unmanned mode after 9 PM tonight.

At this time we expect that the IMPROVE soundings and ice crystal observations should begin around 4
PM tomorrow and run through midnight.

An update will be provided at 10 AM tomorrow morning..

December 4, 2 PM IMPROVE II PROJECT UPDATE

    An IOP has been set for later tomorrow afternoon and tomorrow evening.  A vigorous frontal zone will be moving in during Wednedsay evening, with precipitation reaching the study area around dinner time.  There is some uncertainty about the exact timing of this system, but clearly the bulk of the IOP will be during the evening.

At this time, a closed door time of 3 PM has been set for both the Convair and P3 to handle the uncertainty...however, there is a good chance that aircraft departure time will be delayed.

S-Pol should continue operations, but can be in unmanned mode after 9 PM tonight.

At this time we expect that the IMPROVE soundings and ice crystal observations should begin around 4 PM tomorrow and run through midnight.

An update will be proved at 9:30 PM tonight.
 

December 4, 12 PM ...noon.... IMPROVE II PROJECT UPDATE

    The IOP today, Tuesday, Dec 4, will start at 3 PM or as soon as observations can begin.

The Convair and P3 should leave as soon as possible. This will be a single convair flight and the P3 should fly as late as the duty day allows.

The convair should run on an E-W track

S-Pol should continue operations.

All soundings and ice crytals observations should commence as soon as possible and run through 9 PM tonight.
 

December 4, 9 AM IMPROVE II PROJECT UPDATE

    The IOP today, Tuesday, Dec 4, has been DELAYED UNTIL AT LEAST 3 PM AND MAY BE  SCRUBBED.   The S-Pol should continue operation and all sonde launches and ice crystal observations should be held until further notice.  A more vigorous system looks likely for Wednesday night.

An update will be made at 12 noon today.
 

December 3, 9 PM IMPROVE II PROJECT UPDATE

    The IOP on Tuesday has been DELAYED UNTIL AT LEAST 1 PM AND MAY BE DELAYED FURTHER OR SCRUBBED.   The frontal system is moving faster than originally progged and the following convection on satellite imagery appears weak.   New models suggest more vigorous conditions later in the day.  An update will be made available at 10 AM tomorrow morning.  The S-Pol should continue operation and all sonde launches and ice crystal observations should be held until further notice.  A more vigorous system looks likely for Wednesday night.

Dec 3, 2 PM  IMPROVE II Project Update

    At the 1 PM meeting today (Monday), an IOP was called for tomorrow, starting at 7 AM.  A front  will move through around 7 AM and the area will be in postfrontal showers during the day.  At this point it appears that the orographic precipitation will be strongest in the morning and later in the day during the evening.  There is considerable uncertainty about the strength and timing of the convection, so check the updates tonight and tomorrow morning.

The Convair-580 will operate on the W-E flight track.

The S-Pol radar should be turned on in unmannded mode at 6 PM tonight (Monday)

Snow crystal observers should plan to operate from 7AM until 3 PM Tuesday.

Upstream  and leeside sondes should plan to operate from 7 AM until 3 PM Tuesday, with launches at 15, 18, and 21 z

Special NWS sondes should be launched from Salem at 15 Z , 18 Z , and 21Z on Tuesday
 

Dec 2, 2 PM  IMPROVE II Project Update

    Tomorrow , Monday Dec 3 will be a down day.  However, a front with substantial post-frontal precipitation will be coming through on Tuesday morning  Thus, there is a high likelihood that an IOP will be called for 7 AM on Tuesday.  Wednesday also looks good.  There will be no update tonight at 9 PM--the next one will be at 2 PM tomorrow.

It appears that the Convair has been repaired and thus all observing assets should be ready on Tuesday.  Get a lot of sleep.
 

Dec 1, 4 AM  IMPROVE II Project Update

 The front is moving across the coast at around 4-5 AM and we will be in posfrontal orographic convection after that time.  An enhanced area of convection will reach the study area around  8- 9 AM.  This convection should top out around 10,000-14,000 ft and will weaken after noon.  There will be a 2 PM update on Saturday

The Convair and P3 closed door times will be 7 AM Saturday.  Right now we expect a single Convair flight and a moderate (~6 h P3 flight)..  At 700 mb expect SW (235) winds at 70 knots.  The freezing level should be around 4500-5000 ft.  at 10 AM on both sides of the Cascades.

The Convair-580 will operate on the SW-NE flight track.

The S-Pol radar should be on during the event,.  It can be in unmanned mode overnight.

Snow crystal observers should plan to operate from 7AM until 3 PM Saturday.

Upstream  and leeside sondes should plan to operate from 7 AM until 3 PM Saturday, with launches at 15, 18, and 21 z

Special NWS sondes should be launched from Salem at 15 Z , 18 Z , and 21Z on Saturday
 
 

November 30, 9 PM:  IMPROVE II Project Update

At the 1 PM meeting an IOP was called for tomorrow (Saturday).  A  front should be moving through the IMPROVE area around 7 AM and we will be in posfrontal orographic convection after that time.  This convection should top out around 10,000 ft and will weaken during the morning.  There will also be an update on the phone around 4 AM Saturday, but it is very doubtful anything will be changed.   Sunday will be down day, so there will be no 1 PM meeting at the UW on Saturday.

The Convair and P3 closed door times will be 7 AM Saturday.  Right now we expect a single Convair flight and a moderate (~6 h P3 flight)..  At 700 mb expect SW (235) winds at 70 knots.  The freezing level should be around 4500-5000 ft.  at 10 AM on both sides of the Cascades.

The Convair-580 will operate on the SW-NE flight track.

The S-Pol radar should be on during the event,.  It can be in unmanned mode overnight.

Snow crystal observers should plan to operate from 7AM until 3 PM Saturday.

Upstream  and leeside sondes should plan to operate from 7 AM until 3 PM Saturday, with launches at 15, 18, and 21 z

Special NWS sondes should be launched from Salem at 15 Z , 18 Z , and 21Z on Saturday
 
 
 

November 30, 2 PM:  IMPROVE II Project Update

At the 1 PM meeting an IOP was called for tomorrow (Saturday).  A vigorous front should be moving through the IMPROVE area around 7 AM and we will be in posfrontal orographic convection after that time.  There is some uncertainty about the frontal passage time, so check the 9 PM update.  There will also be an update on the phone around 4 AM Saturday.  It appears that the P3 will be back in service by tomorrow am.   Sunday will be down day, so there will be no 1 PM meeting at the UW on Saturday.

The Convair and P3 closed door times will be 7 AM Saturday.  Right now we expect a single Convair flight and a moderate (~7h P3 flight)...but keep tuned.

The Convair-580 will operate on the SW-NE flight track.

The S-Pol radar should be on during the event, starting tonight and running into tomorrow evening.  It can be in unmanned mode overnight.

Snow crystal observers should plan to operate from 7AM until 5PM Saturday.

Upstream sondes should plan to operate from 7 AM until  5 PM Saturday.

Special NWS sondes should be launched from Salem at 15 Z , 18 Z , and 21Z on Saturday

Lee-side ISS sondes should plan to operate from 7 AM until  5PM Saturday
 

November 29, 2 PM:  IMPROVE II Project Update

   At the 1 PM meeting it was confirmed that FRIDAY will be a down day for aircraft, snow crystal observations, and soundings.  Today's IOP will be over at 3PM and the Spol can go down after that time until tomorrow.  Because of a weak weather disturbance moving through tomorrow, the S-Pol should be on from 12z Friday through 03z  Saturday .

November 28, 9 PM:  IMPROVE II Project Update

IOP 1 has been completed.  IOP 2, which will look at orographic precipitation under northwesterly flow, will take place tomorrow morning.  It is expected that the windward convection will remain below 10,000 feet and will rapidly weaken during the late morning.  It is expected that the IOP will be over by 2 PM.

The freezing level should be approximately 2500 ft during the IOP  on both sides of the Cascades with 700 mb flow from the NW (290) at approximately 30 knots.

The Convair closed door timeis 8 AM.  The P3 is not operational at this time.

The Convair-580 will operate on the W-E flight track.

The S-Pol radar should remain on during the event, but can be in unmmaned mode during the night.

Snow crystal observers should plan to operate from 7AM until 3 PM Thurs.

Upstream sondes should plan to operate from 7 AM until 3PM Thursday.

Special NWS sondes should be launched from Salem at 15 Z , 18 Z , and 21Z on Thursday

Lee-side ISS sondes should plan to operate from 7 AM until 3PM Thursday

FRIDAY WILL BE A DOWN DAY FOR IMPROVE.
 

November 28, 2 PM:  IMPROVE II Project Update

IOP 1 is now underway, with the P3 and Convair airborne and all data collection proceeding.  The cold front has moved through the Willamette Valley and we have transitioned to an unstable convective regime.

At the 1 PM meeting an IOP was called for tomorrow,with close-doors for the aircraft  at 8 AM or as early as the P3 and Convair duty cycles allow.  This would be a shorter IOP--one flight of the Convair and approximately 6 hours for the P3.

The Convair-580 will operate on the W-E flight track.

The S-Pol radar should remain on during the event, but can be in unmmaned mode during the night.

Snow crystal observers should plan to operate from 7AM until 4 PM Thurs.

Upstream sondes should plan to operate from 7 AM until 4 PM Thursday.

Special NWS sondes should be launched from Salem at 15 Z , 18 Z , and 21Z on Thursday

Lee-side ISS sondes should plan to operate from 7 AM until 4 PM Thursday (15, 18, 21, and 00 ).

Coord: CM   Fcst: EG

November 28, 7 AM:  IMPROVE II Project Update

The storm looks very good and is on track with last night's forecast. The warm front has just pushed north of Salem and the new MM5 and eta are consistent with last night's progs.

The Convair 580 and NOAA P3 should close-doors at 8 AM and be in the study area by approximately 9 AM on Wednesday.  The P3 should plan on a full duration flight--9 to 9.5 h--returning at 5-5:30 PM.
The Convair 580 should be prepared for a double legged flight--flying from 8 am to 1 PM, refueling, and then flying from 2:30 PM to approximately 5:30 PM.

The Convair-580 will operate on the SW-NE flight track.

Study area forecast parameters during the flights are:
- 700-mb wind from 240 degrees at 80 knots
- S-Pol freezing level  and Redmond freezing levels will range from appoximate 7000 ft near 10 am to 5000 ft by the end of the IOP (4 PM).  Early in the IOP (7-9 AM) the freezing level will be lower on the eastern side of the Cascades (around 2500 ft), resulting in significant snow.

The S-Pol radar should be switched on at  6 PM today (Tuesday).

Snow crystal observers should plan to operate from 7AM until 6 PM Wednesday.

Upstream sondes should plan to operate from 7 AM until 7 PM Wednesday.

Special NWS sondes should be launched from Salem at 15 Z , 18 Z , 21Z and 03Z.

Lee-side ISS sondes should plan to operate from 7 AM until 7 PM Wednesday (15, 18, 21, 00 and 03Z).

Coord: CM   Fcst: ER
 

November 27, 10 PM:  IMPROVE II Project Update

The 00Z cycle model runs are in general agreement and suggest that substantial orographic precipitation will be occurring over the study area between 18 and 00 UTC tommorrow (10 AM and 4 PM).

The Convair 580 and NOAA P3 should close-doors at 8 AM and be in the study area by approximately 9 AM on Wednesday.  The P3 should plan on a full duration flight--9 to 9.5 h--returning at 5-5:30 PM.
The Convair 580 should be prepared for a double legged flight--flying from 8 am to 1 PM, refueling, and then flying from 2:30 PM to approximately 5:30 PM.

The Convair-580 will operate on the SW-NE flight track.

Study area forecast parameters during the flights are:
- 700-mb wind from 235 degrees at 80 knots
- S-Pol freezing level  and Redmond freezing levels will range from appoximate 8000 ft near 10 am to 5000 ft by the end of the IOP (4 PM)

The S-Pol radar should be switched on at  6 PM today (Tuesday).

Snow crystal observers should plan to operate from 7AM until 6 PM Wednesday.

Upstream sondes should plan to operate from 7 AM until 7 PM Wednesday.

Special NWS sondes should be launched from Salem at 15 Z , 18 Z , 21Z and 03Z.

Lee-side ISS sondes should plan to operate from 7 AM until 7 PM Wednesday (15, 18, 21, 00 and 03Z).

There will be updates to this message until 7AM Wednesday morning.

Coord: CM   Fcst: ER
 

  November 27,  2  PM:  At the meeting today IOP 1 was scheduled to begin tomorrow morning.  A weak warm front will pass through the region overnight, followed by a cold front around 1-3PM tomorrow afternoon.  The winds will turn more southwesterly after the frontal passage, potentially leading to significant orographic precipitation.  Serious consideration was given to the possibility of a second IOP on Thursday morning to study orographic convection in the cold, unstable post frontal flow.  There is considerable uncertainty in the forecast, including the timing of frontal passage.  An update will be available at 10 PM tonight.

Tenative Aircraft Close-Door Time:  8 AM Wednesday
S-Pol Survelliance Mode Start Time:  6 PM today (Tuesday)

   November 26, 2 PM:  At the meeting today it was decided that there will NOT be an IOP tomorrow Tuesday 27November.  It is HIGHLY PROBABLE that there will be an IOP on Wednesday, starting first thing in the morning.  A strong warm front approaches the coast Wednesday morning, followed by a cold/occluded front later that day.   On Thursday the progs suggest a moist, instable situation with considerable precipitation on the windward slopes of the Cascades....thus, the distinct possibility of an IOP on Thursday as well.

Tentative Aircraft Close-Door Time:  7 AM Wednesday
Tentative S-Pol Survelliance Mode Start Time:  6 PM Tuesday

    November 25, 2 PM:  At the daily meeting today it was decided that there will NOT be an IOP tomorrow 26 November.  Tomorrow will be a relatively dry day, with upper level ridging and northwesterly flow dominating.  Current model output suggests a strong warm front approaching the coast Wednesday morning, followed by a cold front later that day.  Thus, it looks highly probable at this point that Wednesday will be the first IOP day of IMPROVE II.  On Thursday the progs suggest a moist, instable situation with considerable precipitation on the windward slopes of the Cascades....thus, the distinct possibility of an IOP on Thursday as well.