AREA FORECAST DISCUSSION...UPDATED
NWS PUEBLO CO
1122 AM MST FRI DEC 30 2011
.UPDATE...
UPDATED TO BOOST TEMPERATURES IN THE LEE OF THE MTS WHERE READINGS
ALREADY APPROACHING FCST HIGHS OF MID 50S. COULD SEE A RIBBON OF 60
DEGREE READINGS IN THESE AREAS. ALSO FINE TUNED WIND GRIDS IN THE
UPPER ARKANSAS RIVER AND NRN EL PASO COUNTY WHERE GUSTY SOUTHWEST
WINDS HAVE ALREADY MIXED DOWN THE SURFACE.
AS FOR HIGH WIND HIGHLIGHTS LATER TONIGHT INTO SATURDAY...WILL
LIKELY BE TAKING MOST OF THE AREA TO WARNINGS WITH NEXT FORECAST
UPDATE/ISSUANCE. MTN TOP WINDS INCREASE TO 50-60 KTS
OVERNIGHT...AND TO 65 TO 70 KTS BY SATURDAY MORNING WHICH SHOULD
EASILY MEET HIGH WIND CRITERIA FOR THE ZONES ABOVE 11KFT. WILL
PROBABLY ADD HIGHER ELEVATIONS OF CHAFFEE/LAKE COUNTIES AS
WELL...WHERE STRONG WINDS WILL LIKELY CAUSE BLOWING SNOW ISSUES. CHALLENGE
WILL BE HOW FAR DOWN THE SLOPES THE STRONGEST WINDS WILL DESCEND.
IT WILL BE WINDY ALL AREAS TOMORROW...HOWEVER MTN WAVE PARAMETERS
ARE NOT THAT FAVORABLE. BUT WITH STRONG DOWNWARD FORCING MOVING
ACROSS THE AREA SAT MORNING BEHIND TROF AXIS...NAM12 HAS 50 KT
WINDS DESCENDING TO 800 MB ACROSS PORTIONS OF PUEBLO...AND KIOWA
COUNTIES. MIXING SHOULD BE DEEP ENOUGH TO TAP THESE WINDS FOR
POTENTIAL WIND GUSTS. WILL WAIT FOR LOCAL 4 KM WRF MODEL RUN
BEFORE DECIDING TO THROW IN THESE ZONES ALONG WITH SRN EL PASO
COUNTY INTO HIGHLIGHT AREA. -KT
&&
.PREV DISCUSSION... /ISSUED 1041 AM MST FRI DEC 30 2011/
AVIATION...
LIGHT SOUTHEAST WINDS WILL PERSIST THROUGH THE EARLY AFTERNOON FOR KCOS
AND KPUB BEFORE WINDS INCREASE FROM THE SOUTH TO SOUTHWEST 10-15
KTS. WINDS AT KCOS WILL SHIFT AROUND FROM THE NORTH BY EARLY
EVENING...WITH KPUB MAINTAINING A WEST WIND AROUND 10KTS THROUGH
THE OVERNIGHT HOURS. AT THIS TIME...WITHOUT STRONG MTN WAVE
PARAMETERS IN PLACE...THINK ANY LOW LEVEL WIND SHEAR WILL STAY TO
THE WEST OF THE TAF SITES...BUT THIS WILL HAVE TO BE MONITORED
CLOSELY OVERNIGHT...ESPECIALLY AT KCOS. EXPECT THAT WINDS WILL
INCREASE ABRUPTLY AT KCOS AROUND 15Z ON SAT...AND AT 16-17Z AT
KPUB WITH GUSTS TO AROUND 40 KTS. WINDS WILL REMAIN LIGHT AT KALS
THROUGH THE PERIOD. GUSTY WINDS AT MTN TOP LEVELS ALONG WITH A
ROUND OF SNOW TOMORROW MORNING WILL PRODUCE MTN OBSCURATIONS AT
TIMES WITH BLOWING SNOW. WINDS AT MTN TOP LEVEL WILL BE SUSTAINED
AROUND 50-60 KTS STARTING AROUND 06Z TONIGHT AND CONTINUING
THROUGH TOMORROW. -KT
PREV DISCUSSION... /ISSUED 350 AM MST FRI DEC 30 2011/
SHORT TERM...
(TODAY AND TONIGHT)
CURRENTLY...COLORADO WAS UNDER BRISK NW FLOW ALOFT...WITH SOME MTN
WAVE CLOUDS SHOWING UP ON SATELLITE OVER THE SW MTS AND THE SANGRES.
CONUS IR SATELLITE IMAGERY ALONG WITH H5 RUC ANALYSIS SHOWED THAT
THE NEXT UPPER SHORTWAVE THAT WILL AFFECT THE REGION BEGINNING LATER
TONIGHT WAS JUST MOVING ONSHORE ACROSS THE PAC NW. CLOSER TO
HOME...WINDS HAVE FINALLY DIMINISHED AND DECOUPLED FOR THE LOWER
ELEVATIONS MAKING FOR A WIDE ARRAY OF SFC TEMPS. GENERALLY...AS OF 3
AM TEMPS HAD DROPPED INTO THE 30S TO UPPER 20S FOR MOST
LOCATIONS...AND IN THE SINGLE DIGITS FOR THE SLV.
TODAY...RELATIVELY QUIET AND MILD DAY FOR THE CWA TODAY UNDER
SHORTWAVE RIDGING...WITH TEMPS WARMING INTO THE UPPER 40S AND 50S
FOR THE PLAINS...AND IN THE 40S FOR THE SLV. WINDS ACROSS THE HIGHER
ELEVATIONS WILL START TO PICK UP THROUGH LATE AFTN AS THE UPPER
DISTURBANCE APPROACHES.
TONIGHT...LATEST MODEL RUNS HAVE SEEMED TO SLOW EVERYTHING DOWN BY
ABOUT 6 HRS OR SO...AND ARE NOW PLACING THE AXIS OF THE UPPER
DISTURBANCE OVER W MONTANA AND IDAHO AT 06Z THIS EVE. THE PRES
GRADIENT TIGHTENS AND THE H5 PLAN VIEW PAINTS THE STANDARD HIGH WIND
SIGNATURE. MODEL CROSS SECTIONS DO SHOW ABOUT 55 TO 60 KTS AT MT
TOP...THEN INCREASE TO 70 KTS BY 12Z. INTERESTING THING IS THAT THE
REVERSE SHEAR IS NOW MORE PROMINENT EARLIER IN THE EVENING...WHEN
WINDS ARE NOT FORECAST TO BE AS STRONG...THEN AFTER MIDNIGHT WHEN
WINDS START TO INCREASE THE REVERSE SHEAR DISAPPEARS. WITH THESE
LINGERING QUESTIONS...AND AFTER TALKING TO OUR NEIGHBORS TO THE
NORTH...HAVE DECIDED TO KEEP THE WATCH AS IS FOR NOW.
HOPEFULLY...THE 12Z RUN WILL BE ENLIGHTENING FOR THE NEXT SHIFT.
REGARDLESS...IT WILL GET WINDY ACROSS THE HIGHLIGHT AREAS LATE
TONIGHT THROUGH AT LEAST MIDDAY SAT...BUT WHETHER WINDS WILL MEET
WARNING CRITERIA IS STILL A QUESTION. 27
LONG TERM...
.WINDY SATURDAY...
MAIN CONCERN THIS FCST PERIOD IS WINDS FOR SATURDAY. STRONG
DISTURBANCE WILL MOVE TO THE NORTH OF THE REGION DURING THIS DAY.
STRONG GRADIENT WILL CAUSE STRONG WEST WINDS TO OCCUR DURING THE
LATE MORNING AND AFTERNOON. STRONGEST WINDS WILL OCCUR OVER THE
HIGHER ELEVATIONS OF THE MTNS AND ACROSS THE N SECTIONS OF THE
PLAINS. AS FOR WIND HILITES...DID NOT MAKE ANY CHANGES ATTM AS
SIMULATIONS SHOW THE STRONGEST FLOW WHERE CURRENT HILITES ARE IN
PLACE. THERE IS A POSSIBILITY THAT WIND HILITES MAY NEED TO BE
EXTENDED A BIT FARTHER SOUTH TO COVER PUEBLO...S EL PASO AND
POSSIBLY KIOWA COUNTY...AND WILL MAKE THE DAY SHIFT AWARE OF THIS
WHEN THEY ARRIVE LATER THIS MORNING.
FLOW RAPIDLY DECREASES LATE IN THE DAY ACROSS MOST OF THE REGION
EXCEPT THE FAR NE PLAINS. WINDS ARE FCST TO BE NEAR CALM BY 00Z
SUNDAY OVER THE I-25 CORRIDOR REGION ON BOTH THE GFS AND NAM.
WX AFTER SAT WILL BE RATHER TRANQUIL. A WEAK DISTURBANCE WILL MOVE
ACROSS THE REGION DURING THE MID WEEK TIME FRAME...WED-ISH...BUT
THIS SYSTEM APPEARS TO BE DRY WITH ONLY A SLIGHT COOLING. THE NEXT
CHANCE OF ANY PRECIP WILL LIKELY BE NEXT WEEKEND. /34
AVIATION...
VFR CONDITIONS EXPECTED AT THE THREE MAIN TAF SITES OF KCOS...KPUB
AND KALS FOR THE NEXT 24 HRS. HOWEVER...WINDS ALOFT WILL STAY BRISK
THROUGH THE DAY. 700 MB WINDS WILL BEGIN TO STRENGTHEN TONIGHT AFTER
06Z AND BE WNW 50 KTS...WITH 70 KTS AND POTENTIALLY HIGHER AT MTN
TOP EXPECTED. THIS WILL CAUSE BLOWING SNOW AND SOME RESTRICTED VSBLY
OVER THE PASSES LATE TONIGHT.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WATCH FROM SATURDAY MORNING THROUGH SATURDAY AFTERNOON
FOR COZ077-078-083-084.
HIGH WIND WATCH FROM LATE TONIGHT THROUGH SATURDAY AFTERNOON FOR
COZ072-073-075-076-079>082.
&&
$$
31/23
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1041 AM MST FRI DEC 30 2011
.AVIATION...
LIGHT SOUTHEAST WINDS WILL PERSIST THROUGH THE EARLY AFTERNOON FOR KCOS
AND KPUB BEFORE WINDS INCREASE FROM THE SOUTH TO SOUTHWEST 10-15
KTS. WINDS AT KCOS WILL SHIFT AROUND FROM THE NORTH BY EARLY
EVENING...WITH KPUB MAINTAINING A WEST WIND AROUND 10KTS THROUGH
THE OVERNIGHT HOURS. AT THIS TIME...WITHOUT STRONG MTN WAVE
PARAMETERS IN PLACE...THINK ANY LOW LEVEL WIND SHEAR WILL STAY TO
THE WEST OF THE TAF SITES...BUT THIS WILL HAVE TO BE MONITORED
CLOSELY OVERNIGHT...ESPECIALLY AT KCOS. EXPECT THAT WINDS WILL
INCREASE ABRUPTLY AT KCOS AROUND 15Z ON SAT...AND AT 16-17Z AT
KPUB WITH GUSTS TO AROUND 40 KTS. WINDS WILL REMAIN LIGHT AT KALS
THROUGH THE PERIOD. GUSTY WINDS AT MTN TOP LEVELS ALONG WITH A
ROUND OF SNOW TOMORROW MORNING WILL PRODUCE MTN OBSCURATIONS AT
TIMES WITH BLOWING SNOW. WINDS AT MTN TOP LEVEL WILL BE SUSTAINED
AROUND 50-60 KTS STARTING AROUND 06Z TONIGHT AND CONTINUING
THROUGH TOMORROW. -KT
&&
.PREV DISCUSSION... /ISSUED 350 AM MST FRI DEC 30 2011/
SHORT TERM...
(TODAY AND TONIGHT)
CURRENTLY...COLORADO WAS UNDER BRISK NW FLOW ALOFT...WITH SOME MTN
WAVE CLOUDS SHOWING UP ON SATELLITE OVER THE SW MTS AND THE SANGRES.
CONUS IR SATELLITE IMAGERY ALONG WITH H5 RUC ANALYSIS SHOWED THAT
THE NEXT UPPER SHORTWAVE THAT WILL AFFECT THE REGION BEGINNING LATER
TONIGHT WAS JUST MOVING ONSHORE ACROSS THE PAC NW. CLOSER TO
HOME...WINDS HAVE FINALLY DIMINISHED AND DECOUPLED FOR THE LOWER
ELEVATIONS MAKING FOR A WIDE ARRAY OF SFC TEMPS. GENERALLY...AS OF 3
AM TEMPS HAD DROPPED INTO THE 30S TO UPPER 20S FOR MOST
LOCATIONS...AND IN THE SINGLE DIGITS FOR THE SLV.
TODAY...RELATIVELY QUIET AND MILD DAY FOR THE CWA TODAY UNDER
SHORTWAVE RIDGING...WITH TEMPS WARMING INTO THE UPPER 40S AND 50S
FOR THE PLAINS...AND IN THE 40S FOR THE SLV. WINDS ACROSS THE HIGHER
ELEVATIONS WILL START TO PICK UP THROUGH LATE AFTN AS THE UPPER
DISTURBANCE APPROACHES.
TONIGHT...LATEST MODEL RUNS HAVE SEEMED TO SLOW EVERYTHING DOWN BY
ABOUT 6 HRS OR SO...AND ARE NOW PLACING THE AXIS OF THE UPPER
DISTURBANCE OVER W MONTANA AND IDAHO AT 06Z THIS EVE. THE PRES
GRADIENT TIGHTENS AND THE H5 PLAN VIEW PAINTS THE STANDARD HIGH WIND
SIGNATURE. MODEL CROSS SECTIONS DO SHOW ABOUT 55 TO 60 KTS AT MT
TOP...THEN INCREASE TO 70 KTS BY 12Z. INTERESTING THING IS THAT THE
REVERSE SHEAR IS NOW MORE PROMINENT EARLIER IN THE EVENING...WHEN
WINDS ARE NOT FORECAST TO BE AS STRONG...THEN AFTER MIDNIGHT WHEN
WINDS START TO INCREASE THE REVERSE SHEAR DISAPPEARS. WITH THESE
LINGERING QUESTIONS...AND AFTER TALKING TO OUR NEIGHBORS TO THE
NORTH...HAVE DECIDED TO KEEP THE WATCH AS IS FOR NOW.
HOPEFULLY...THE 12Z RUN WILL BE ENLIGHTENING FOR THE NEXT SHIFT.
REGARDLESS...IT WILL GET WINDY ACROSS THE HIGHLIGHT AREAS LATE
TONIGHT THROUGH AT LEAST MIDDAY SAT...BUT WHETHER WINDS WILL MEET
WARNING CRITERIA IS STILL A QUESTION. 27
LONG TERM...
..WINDY SATURDAY...
MAIN CONCERN THIS FCST PERIOD IS WINDS FOR SATURDAY. STRONG
DISTURBANCE WILL MOVE TO THE NORTH OF THE REGION DURING THIS DAY.
STRONG GRADIENT WILL CAUSE STRONG WEST WINDS TO OCCUR DURING THE
LATE MORNING AND AFTERNOON. STRONGEST WINDS WILL OCCUR OVER THE
HIGHER ELEVATIONS OF THE MTNS AND ACROSS THE N SECTIONS OF THE
PLAINS. AS FOR WIND HILITES...DID NOT MAKE ANY CHANGES ATTM AS
SIMULATIONS SHOW THE STRONGEST FLOW WHERE CURRENT HILITES ARE IN
PLACE. THERE IS A POSSIBILITY THAT WIND HILITES MAY NEED TO BE
EXTENDED A BIT FARTHER SOUTH TO COVER PUEBLO...S EL PASO AND
POSSIBLY KIOWA COUNTY...AND WILL MAKE THE DAY SHIFT AWARE OF THIS
WHEN THEY ARRIVE LATER THIS MORNING.
FLOW RAPIDLY DECREASES LATE IN THE DAY ACROSS MOST OF THE REGION
EXCEPT THE FAR NE PLAINS. WINDS ARE FCST TO BE NEAR CALM BY 00Z
SUNDAY OVER THE I-25 CORRIDOR REGION ON BOTH THE GFS AND NAM.
WX AFTER SAT WILL BE RATHER TRANQUIL. A WEAK DISTURBANCE WILL MOVE
ACROSS THE REGION DURING THE MID WEEK TIME FRAME...WED-ISH...BUT
THIS SYSTEM APPEARS TO BE DRY WITH ONLY A SLIGHT COOLING. THE NEXT
CHANCE OF ANY PRECIP WILL LIKELY BE NEXT WEEKEND. /34
AVIATION...
VFR CONDITIONS EXPECTED AT THE THREE MAIN TAF SITES OF KCOS...KPUB
AND KALS FOR THE NEXT 24 HRS. HOWEVER...WINDS ALOFT WILL STAY BRISK
THROUGH THE DAY. 700 MB WINDS WILL BEGIN TO STRENGTHEN TONIGHT AFTER
06Z AND BE WNW 50 KTS...WITH 70 KTS AND POTENTIALLY HIGHER AT MTN
TOP EXPECTED. THIS WILL CAUSE BLOWING SNOW AND SOME RESTRICTED VSBLY
OVER THE PASSES LATE TONIGHT.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WATCH FROM SATURDAY MORNING THROUGH SATURDAY AFTERNOON
FOR COZ077-078-083-084.
HIGH WIND WATCH FROM LATE TONIGHT THROUGH SATURDAY AFTERNOON FOR
COZ072-073-075-076-079>082.
&&
$$
31/23
AREA FORECAST DISCUSSION
NWS PUEBLO CO
350 AM MST FRI DEC 30 2011
.SHORT TERM...
(TODAY AND TONIGHT)
CURRENTLY...COLORADO WAS UNDER BRISK NW FLOW ALOFT...WITH SOME MTN
WAVE CLOUDS SHOWING UP ON SATELLITE OVER THE SW MTS AND THE SANGRES.
CONUS IR SATELLITE IMAGERY ALONG WITH H5 RUC ANALYSIS SHOWED THAT
THE NEXT UPPER SHORTWAVE THAT WILL AFFECT THE REGION BEGINNING LATER
TONIGHT WAS JUST MOVING ONSHORE ACROSS THE PAC NW. CLOSER TO
HOME...WINDS HAVE FINALLY DIMINISHED AND DECOUPLED FOR THE LOWER
ELEVATIONS MAKING FOR A WIDE ARRAY OF SFC TEMPS. GENERALLY...AS OF 3
AM TEMPS HAD DROPPED INTO THE 30S TO UPPER 20S FOR MOST
LOCATIONS...AND IN THE SINGLE DIGITS FOR THE SLV.
TODAY...RELATIVELY QUIET AND MILD DAY FOR THE CWA TODAY UNDER
SHORTWAVE RIDGING...WITH TEMPS WARMING INTO THE UPPER 40S AND 50S
FOR THE PLAINS...AND IN THE 40S FOR THE SLV. WINDS ACROSS THE HIGHER
ELEVATIONS WILL START TO PICK UP THROUGH LATE AFTN AS THE UPPER
DISTURBANCE APPROACHES.
TONIGHT...LATEST MODEL RUNS HAVE SEEMED TO SLOW EVERYTHING DOWN BY
ABOUT 6 HRS OR SO...AND ARE NOW PLACING THE AXIS OF THE UPPER
DISTURBANCE OVER W MONTANA AND IDAHO AT 06Z THIS EVE. THE PRES
GRADIENT TIGHTENS AND THE H5 PLAN VIEW PAINTS THE STANDARD HIGH WIND
SIGNATURE. MODEL CROSS SECTIONS DO SHOW ABOUT 55 TO 60 KTS AT MT
TOP...THEN INCREASE TO 70 KTS BY 12Z. INTERESTING THING IS THAT THE
REVERSE SHEAR IS NOW MORE PROMINENT EARLIER IN THE EVENING...WHEN
WINDS ARE NOT FORECAST TO BE AS STRONG...THEN AFTER MIDNIGHT WHEN
WINDS START TO INCREASE THE REVERSE SHEAR DISAPPEARS. WITH THESE
LINGERING QUESTIONS...AND AFTER TALKING TO OUR NEIGHBORS TO THE
NORTH...HAVE DECIDED TO KEEP THE WATCH AS IS FOR NOW.
HOPEFULLY...THE 12Z RUN WILL BE ENLIGHTENING FOR THE NEXT SHIFT.
REGARDLESS...IT WILL GET WINDY ACROSS THE HIGHLIGHT AREAS LATE
TONIGHT THROUGH AT LEAST MIDDAY SAT...BUT WHETHER WINDS WILL MEET
WARNING CRITERIA IS STILL A QUESTION. MOORE
.LONG TERM...
...WINDY SATURDAY...
MAIN CONCERN THIS FCST PERIOD IS WINDS FOR SATURDAY. STRONG
DISTURBANCE WILL MOVE TO THE NORTH OF THE REGION DURING THIS DAY.
STRONG GRADIENT WILL CAUSE STRONG WEST WINDS TO OCCUR DURING THE
LATE MORNING AND AFTERNOON. STRONGEST WINDS WILL OCCUR OVER THE
HIGHER ELEVATIONS OF THE MTNS AND ACROSS THE N SECTIONS OF THE
PLAINS. AS FOR WIND HILITES...DID NOT MAKE ANY CHANGES ATTM AS
SIMULATIONS SHOW THE STRONGEST FLOW WHERE CURRENT HILITES ARE IN
PLACE. THERE IS A POSSIBILITY THAT WIND HILITES MAY NEED TO BE
EXTENDED A BIT FARTHER SOUTH TO COVER PUEBLO...S EL PASO AND
POSSIBLY KIOWA COUNTY...AND WILL MAKE THE DAY SHIFT AWARE OF THIS
WHEN THEY ARRIVE LATER THIS MORNING.
FLOW RAPIDLY DECREASES LATE IN THE DAY ACROSS MOST OF THE REGION
EXCEPT THE FAR NE PLAINS. WINDS ARE FCST TO BE NEAR CALM BY 00Z
SUNDAY OVER THE I-25 CORRIDOR REGION ON BOTH THE GFS AND NAM.
WX AFTER SAT WILL BE RATHER TRANQUIL. A WEAK DISTURBANCE WILL MOVE
ACROSS THE REGION DURING THE MID WEEK TIME FRAME...WED-ISH...BUT
THIS SYSTEM APPEARS TO BE DRY WITH ONLY A SLIGHT COOLING. THE NEXT
CHANCE OF ANY PRECIP WILL LIKELY BE NEXT WEEKEND. /HODANISH
&&
.AVIATION...
VFR CONDITIONS EXPECTED AT THE THREE MAIN TAF SITES OF KCOS...KPUB
AND KALS FOR THE NEXT 24 HRS. HOWEVER...WINDS ALOFT WILL STAY BRISK
THROUGH THE DAY. 700 MB WINDS WILL BEGIN TO STRENGTHEN TONIGHT AFTER
06Z AND BE WNW 50 KTS...WITH 70 KTS AND POTENTIALLY HIGHER AT MTN
TOP EXPECTED. THIS WILL CAUSE BLOWING SNOW AND SOME RESTRICTED VSBLY
OVER THE PASSES LATE TONIGHT.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WATCH FROM SATURDAY MORNING THROUGH SATURDAY AFTERNOON
FOR COZ077-078-083-084.
HIGH WIND WATCH FROM LATE TONIGHT THROUGH SATURDAY AFTERNOON FOR
COZ072-073-075-076-079>082.
&&
$$
27/34
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
353 AM EST SUN JAN 1 2012
.UPDATE...
THE SYNOPSIS...NEAR TERM...SHORT TERM AND LONG TERM SECTIONS HAVE
BEEN UPDATED BELOW.
&&
.SYNOPSIS...
A STRONG COLD FRONT WILL SWEEP ACROSS CENTRAL INDIANA THIS
MORNING...USHERING IN MUCH COLDER ARCTIC AIR FOR THE FIRST FEW DAYS
OF THE NEW YEAR ALONG WITH STRONG WINDS. SOME LIGHT PRECIPITATION
MAY ACCOMPANY THE FRONTAL PASSAGE. CHANCES FOR FLURRIES AND LIGHT
SNOW SHOWERS COME MONDAY INTO EARLY TUESDAY ACROSS NORTHERN AND
EASTERN PORTIONS OF THE FORECAST AREA AS A STRONG UPPER LEVEL
DISTURBANCE OVER THE GREAT LAKES PULLS AWAY SLOWLY. HIGH PRESSURE
WILL RETURN ON TUESDAY BRINGING DRY COLD WEATHER. A SLOW WARMING
TREND DURING THE SECOND HALF OF THE WEEK WILL BRING TEMPERATURES
BACK TO ABOVE NORMAL LEVELS BY FRIDAY.
&&
.NEAR TERM /TODAY/...
SURFACE ANALYSIS AS OF 08Z PLACES LOW PRESSURE OVER FAR EASTERN IOWA
WITH A COLD FRONT EXTENDING SOUTH THROUGH CENTRAL ILLINOIS. WARM
ADVECTION AND ISENTROPIC LIFT AHEAD OF THE FRONT HAD ENABLED
STRATOCU TO FORM OVER THE EASTERN HALF OF THE FORECAST AREA.
TEMPERATURES HAVE WARMED STEADILY SINCE MIDNIGHT IN THE WARM
ADVECTION...WITH MUCH OF THE FORECAST AREA IN THE 40S.
FOCUS FOR TODAY IS ON TEMPS AND WIND GUSTS AS THE FRONT SWEEPS
ACROSS THE REGION THIS MORNING. EXTRAPOLATION TO CURRENT OBS BRINGS
THE FRONT ACROSS THE STATE LINE AND INTO THE WABASH VALLEY AROUND
1130-12Z...PROGRESSING EASTWARD ACROSS THE FORECAST AREA THROUGHOUT
THE MORNING. STRONGER GUSTS ARE POST-FRONTAL AND WITH THAT IN
MIND...WILL BE DELAYING THE START TIME OF THE WIND ADVISORY ACROSS
THE WABASH VALLEY BACK TO 12Z TO MATCH UP WITH THE REST OF THE
HEADLINE ACROSS CENTRAL INDIANA. SEEING LIGHT PRECIP EARLY THIS
MORNING ACROSS CENTRAL MISSOURI WITHIN AREA OF DEEPER MOISTURE RIGHT
BEHIND THE FRONT. SHORT RANGE MODEL GUIDANCE FAIRLY CONSISTENT IN
BRINGING THIS AREA OF MOISTURE ACROSS THE FORECAST AREA THROUGH
18Z...WITH POTENTIAL FOR LIGHT RAIN OR SPRINKLES. AS THE COLDER AIR
STEADILY SPILLS INTO THE REGION...MAY SEE A FEW SNOWFLAKES MIX IN
WITH THE RAIN BEFORE THE PRECIP CHANCES END. WILL CONTINUE TO CARRY
LOW CHANCE POPS ACROSS NORTHERN HALF OF THE FORECAST AREA THROUGH
18Z WHERE DEEPEST MOISTURE WILL RESIDE.
MUCH GREATER FOCUS WILL BE ON THE GUSTY WINDS...ESPECIALLY BY THIS
AFTERNOON AS LOW LEVEL MIXING MAY EXTEND ALL THE WAY UP TO AROUND
5-6KFT AS COLD ADVECTION INTENSIFIES INTO THE REGION. THINK POTENTIAL
FOR STRONGEST WIND GUSTS WITHIN THE ADVISORY CATEGORY WILL TAKE
PLACE AFTER 16Z...PARTICULARLY IF CLOUDS CAN SCATTER FOR A PERIOD OF
TIME WHICH WOULD ENHANCE THE MIXING HEIGHTS INTO THE BOUNDARY LAYER.
THIS SEEMS PLAUSIBLE AS THE DRIER ARCTIC AIRMASS SURGES INTO THE
FORECAST AREA THIS AFTERNOON AND MODEL SOUNDINGS ARE SUPPORTIVE OF A
FEW HOURS WITH PARTLY CLOUDY OR POSSIBLY EVEN MOSTLY SUNNY SKIES.
POTENTIAL CONTINUES FOR WESTERLY SUSTAINEDS AT 20-30MPH WITH MAX
WIND GUSTS AROUND 50MPH.
TEMPS...HIGHS WILL TAKE PLACE DURING THE MORNING PRIOR TO FRONTAL
PASSAGE. UTILIZED RUC GUIDANCE TO GET THE NON-DIURNAL TREND FOR THE
DAY AND CAPTURE TEMPS THIS MORNING AHEAD OF THE FRONT. ENDED UP
SEVERAL DEGREES ABOVE GUIDANCE FOR HIGHS AS MOST LOCATIONS SHOULD BE
IN THE MID AND UPPER 40S BEFORE THE FRONT PASSES. MORE SUBSTANTIAL
TEMP FALLS INTO THE LOWER AND MID 30S SHOULD HOLD OFF UNTIL THE
AFTERNOON AS STRONGER COLD ADVECTION ARRIVES.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
FORECAST CHALLENGES FOCUS ON POTENTIAL FOR FLURRIES/LIGHT SNOW
SHOWERS THROUGH EARLY TUESDAY AS UPPER TROUGH DEEPENS OVER THE GREAT
LAKES AND MOVES ONLY SLOWLY OFF TO THE EAST.
WINDS WILL CONTINUE TO HOWL THIS EVENING WITH THE UPPER LEVELS
AMPLIFYING AS ADDITIONAL ENERGY DIVES INTO THE TROUGH. MODEL
SOUNDINGS CONTINUE TO SHOW MODEST MIXING THROUGH THE LOWER LEVELS
WELL INTO THE EVENING...WITH STRONGER WINDS WITHIN THE BOUNDARY
LAYER NOT SHIFTING EAST OF THE REGION UNTIL CLOSER TO MIDNIGHT. HAVE
THEREFORE CHOSEN TO EXTEND THE WIND ADVISORY THROUGH 03Z AS MAX
GUSTS MAY LINGER NEAR ADVISORY CRITERIA. GUSTS SHOULD SLOWLY WEAKEN
TO CLOSER TO 30-35MPH AFTER MIDNIGHT AS THE MIXING LEVEL DROPS. THE
AMPLIFICATION OF THE TROUGH ALOFT WILL ENABLE DEEPER LOW LEVEL
MOISTURE TO SPILL BACK SOUTH INTO THE FORECAST AREA WITH STRATOCU
EXPANDING ACROSS THE NORTHERN HALF OF THE FORECAST AREA.
PERSISTENT FORCING WITHIN THE MID LEVELS WILL FURTHER AMPLIFY THE
UPPER TROUGH INTO CENTRAL INDIANA ON MONDAY...BRINGING A VERY COLD
BLUSTERY DAY WITH AN ABUNDANCE OF CLOUD COVER. LOW LEVEL FLOW
LARGELY OUT OF THE W/NW SHOULD KEEP MORE PERSISTENT SNOW SHOWERS
CONFINED TO JUST FAR NORTHEAST COUNTIES OR POSSIBLY EVEN COMPLETELY
NORTH OF THE FORECAST AREA FOR MUCH OF THE DAY. WILL MAINTAIN
MENTION OF SCATTERED FLURRIES BACK WEST TO NEAR THE I-65 CORRIDOR
WITH THE FORCING ALOFT PRESENT. LOW LEVEL FLOW DOES VEER TO A MORE
NW DIRECTION MONDAY NIGHT...BUT OVERALL WIND PROFILES ARE NOT AS
FAVORABLE AS PREVIOUS MODEL GUIDANCE INDICATED IN BRINGING MORE
PERSISTENT SNOW SHOWERS INTO A LARGER PORTION OF THE FORECAST AREA.
MODELS CONTINUE TO ADVERTISE THE DEVELOPMENT OF A SINGLE DOMINANT
BAND OFF LAKE MICHIGAN MONDAY NIGHT/EARLY TUESDAY. LOW LEVEL WIND
TRAJECTORIES SUGGESTIVE OF BRINGING REMNANTS OF THE BAND INTO
DELAWARE/MADISON/RANDOLPH COUNTIES AND WILL CONTINUE WITH LOW CHANCE
POPS THROUGH TUESDAY MORNING IN THESE AREAS. AM NOT AS CONFIDENT IN
WESTERN EXTENT TO FLURRIES/LIGHT SNOW SHOWERS WITH TRAJECTORIES NOT
AS VEERED. WHILE PRESENCE OF THE FORCING ALOFT AND BACK SIDE UPPER
JET DIVING INTO THE TROUGH COULD BOTH BE FACTORS IN KEEPING FLURRIES
GOING FOR MUCH OF THE NIGHT ALL THE WAY BACK TO THE I-65 CORRIDOR...
HAVE ELECTED TO KEEP ANY MENTION OF PRECIP TO THE NORTHEAST OF THE
INDY METRO AND LAFAYETTE AREAS AT THIS TIME.
HIGH PRESSURE RIDGE FINALLY BUILDS IN TUESDAY WITH LOW LEVEL FLOW
BACKING AND WEAKENING. THIS WILL END ANY FLURRIES AND ALLOW LOW
CLOUDS TO SCATTER BY TUESDAY AFTERNOON. MAINLY CLEAR SKIES WILL
CONTINUE INTO TUESDAY EVENING BEFORE CLOUDS RETURN AS A WEAK
DISTURBANCE ALOFT MOVES INTO THE GREAT LAKES. NOT EXPECTING ANY
PRECIPITATION WITH THIS FEATURE AS FORCING REMAINS CONFINED WELL
NORTH OF THE REGION.
TEMPS...LEANED TOWARDS MET GUIDANCE THROUGH MONDAY NIGHT AS NAM
TRADITIONALLY SAMPLES ARCTIC AIRMASS BETTER THAN OTHER MODELS.
LEANED TOWARDS COOLER MOS FOR HIGHS ON TUESDAY AS TEMPS WILL LIKELY
HOLD IN THE MID 20S ACROSS MUCH OF THE REGION. TEMPS NOT LIKELY TO
FALL MUCH LOWER THAN 20 DEGREES TUESDAY NIGHT AS INCREASING CLOUDS
AND WARM ADVECTION TAKES ROOT AHEAD OF THE UPPER LEVEL DISTURBANCE
MOVING INTO THE GREAT LAKES.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
STRONG RIDGING ALOFT WILL DOMINATE THE MAJORITY OF THE EXTENDED
FORECAST. AS A RESULT...DRY CONDITIONS WILL PREVAIL FROM WEDNESDAY
THROUGH FRIDAY. THE NEXT CHANCE FOR ANY PRECIP WILL BE AT THE END
OF THE LONG TERM PERIOD WHEN A SYSTEM TRACKS ACROSS THE GREAT LAKES
REGION. HOWEVER...MODELS ARE STILL KEEPING THE BEST LIFT AND PRECIP
NORTH OF CENTRAL INDIANA. INITIALIZATION IS ONLY SHOWING SLIGHT
CHANCE POPS ON SATURDAY...WHICH STILL LOOKS REASONABLE. FURTHER
OUT...THE NEXT SYSTEM TO WATCH WILL BE COMING OUT OF THE PLAINS ON
SUNDAY. AT THIS TIME...INITIALIZATION NUMBERS ARE FAVORING THE GFS.
THE EURO IS NOT EVEN HINTING AT A DISTURBANCE AT THIS TIME AND
CONTINUES WITH ZONAL FLOW UNTIL DAY 9.
TEMPS WILL CLIMB BACK TO ABOVE NORMAL AND REMAIN THAT WAY FOR THE
DURATION OF THE EXTENDED PERIOD. HIGHS WILL TOP OFF IN THE 40S...AND
EVEN LOW 50S BY FRIDAY. OVERNIGHT LOWS WILL ALSO BE ABOVE NORMAL
WITH READINGS IN THE UPPER 20S/LOW 30S.
&&
.AVIATION /DISCUSSION FOR THE 01/09 TAF UPDATE/...
UPDATE...
INCREASED CLOUD COVER...BUT HAD TO BACK UP THE TIMING OF WIND
GUSTS BY A FEW HOURS. FRONT SEEMS TO BE LAGGING A BIT.
PREVIOUS DISCUSSION...
A STRENGTHENING LOW PRESSURE SYSTEM WILL MOVE ACROSS THE GREAT
LAKES THROUGH TOMORROW CREATING A VERY STRONG PRESSURE GRADIENT
ACROSS THE AREA WHICH WILL THEN MAKE FOR VERY WINDY CONDITIONS
FOR ALL TERMINALS FROM EARLY THIS MORNING AND CONTINUING
THROUGHOUT TODAY AND EVEN SUN NIGHT. HOWEVER...FORECAST SOUNDINGS
INDICATE AN INVERSION WILL BE IN PLACE ATTM AS WINDS ALOFT
INCREASE AND THUS WIND SHEAR IS/WILL BE IN PLACE OVER THE AREA AND
CONTINUING UNTIL THE INVERSION BREAKS AND THOSE WINDS CAN MIX
DOWN...WHICH IN THE SOUNDINGS STILL LOOKS LIKE AROUND 9-10Z.
EXPECTING SUSTAINED WINDS ABOVE 20 KTS WITH GUSTS AROUND (OR
NEARING) 40 KTS BY MID MORNING AND THROUGH THE REST OF THE DAY.
BREEZY TO WINDY CONDITIONS WILL BE IN STORE FOR SUNDAY NIGHT AS
WELL...WITH GUSTS AROUND 30 KTS STILL POSSIBLE.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 7 AM THIS MORNING TO 10 PM EST THIS EVENING
FOR INZ021-028>031-035>049-051>057-060>065-067>072.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...RYAN
SHORT TERM...RYAN
LONG TERM....TDUD
AVIATION...TDUD
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1200 PM CST FRI DEC 30 2011
.UPDATE...
STARTING TO GET REPORTS OF THE RAIN TURNING NOW TO LIGHT
SLEET/SNOW AT EDGEWOOD AND STANLEY IN OUR FAR NORTHWEST CWA.
TEMPERATURES THERE HAD DROPPED TO THE FREEZING MARK BUT OBSERVERS
MENTIONED THE SNOW/SLEET WAS MELTING UPON CONTACT WITH THE GROUND.
HOWEVER BE CAREFUL ON BRIDGES/OVERPASSES AS THEY ARE COLDER. ELSEWHERE
ACROSS THE DVN CWA LIGHT RAIN WAS STILL FALLING WITH TEMPERATURES
IN THE MID 30S TO LOWER 40S. HAVE ALREADY UPDATED THE FORECAST TO
REDUCE SNOW ACCUMULATIONS IN OUR FAR NORTHWEST TO LESS THAN ONE-
HALF INCH. RADAR LOOPS SUGGEST PRECIPITATION RETURNS WERE
DIMINISHING AS THE MOISTURE GETS CUT OFF DUE TO THE OCCLUDING
STAGE OF THE CYCLONE THAT IS LOCATED EAST OF GENESEO IL IN HENRY
COUNTY. LATEST RUC STILL INDICATES A TRANSITION TO A MIX OF LIGHT
RAIN AND SNOW ACROSS OUR NORTH AS THE AFTERNOON PROGRESSES WITH
PRECIPITATION ENDING IN OUR IL COUNTIES THIS EVENING.
&&
.AVIATION...
IFR CONDS IN -RA/BR/FG THROUGH THE AFTERNOON WITH THE RAIN
CHANGING TO -SN/-IP AT KDBQ AND POSSIBLY KCID. PRECIPITATION TO
END EARLY THIS EVENING THEN CIGS BECOMING MVFR. SKIES WILL BE
CLEARING OVERNIGHT AS HIGH PRESSURE BUILDS INTO THE AREA. VFR
CONDS EXPECTED ON SATURDAY. NORTHWEST WINDS GUSTING TO 20 KNOTS
THIS AFTERNOON THEN WINDS DIMINISHING TO LESS THAN 10 KNOTS THIS
EVENING. VARIABLE WINDS LESS THAN 5 KNOTS LATE TONIGHT THEN
TURNING SOUTH AND INCREASING TO 15 TO 25 KNOTS BY SATURDAY AFTERNOON.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
HAASE
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
813 AM CST FRI DEC 30 2011
.UPDATE...
SFC LOW IS NOW MOVING INTO KEOKUK COUNTY BASED ON A WEST WIND AT
KOOA. SFC LOW IS 1MB DEEPER THAN DEPICTED BY THE RUC. PRESSURE
FALLS INDICATE THE SFC LOW WILL CONTINUE MOVING JUST SOUTH OF EAST
AND SHOULD PASS BETWEEN KPIA AND KC75 EARLY THIS AFTERNOON.
BASED ON SFC AND 925MB WBZ TEMPERATURES ANY RASN MIX IS GENERALLY
ALONG AND NORTH OF A KOLZ TO KUGN LINE. RUC TRENDS INDICATE A
CHANGE OVER TO ALL RAIN IS COMPLETE. THE QUESTION IS WHAT HAPPENS
WITH PTYPE LATER THIS MORNING AND AFTERNOON SINCE THE LOW IS
SLIGHTLY STRONGER THAN PROGGED AND THE FACT AN INVERTED TROF WILL
BE MOVING THROUGH THE AREA.
RUC TRENDS INDICATE 925MB WBZ TEMPERATURES DROPPING BELOW 32 BY
MID DAY OVER THE WESTERN THIRD OF THE CWFA AND ROUGHLY THE WESTERN
HALF BY MID AFTERNOON. SFC WBZ TEMPERATURES HOWEVER REMAIN AT OR
ABOVE 32 DEGREES. MORE IMPORTANTLY...SFC WBZ TEMPERATURES REMAIN
AT 34 DEGREES OR HIGHER ALONG OVER ALL BUT THE NORTHWEST QUADRANT
OF THE CWFA THROUGH MID AFTERNOON. BY LATE AFTERNOON WBZ
TEMPERATURES ARE DROPPING BELOW 34 DEGREES IN THE HWY 20 CORRIDOR
EAST OF DUBUQUE.
ANOTHER CONCERN IS THE INVERTED TROF IN CENTRAL IOWA. SFC OBS SHOW
SNOW IS DEVELOPING WEST OF THE INVERTED TROF WHERE WBZ ARE BELOW
32 DEGREES AT 925MB AND AT OR BELOW 34 DEGREES AT THE SFC.
THUS IS APPEARS THAT A RASN MIX WILL MOVE INTO THE NORTHWEST
QUADRANT OF THE CWFA STARTING LATE THIS MORNING AND CONTINUING
INTO THE AFTERNOON. THERE MAY OR MAY NOT BE A COMPLETE CHANGE OVER
IN THIS AREA BUT FCST SOUNDINGS DO SUPPORT A CHANGE OVER TO ALL
SNOW. BY LATE AFTERNOON A RASN MIX SHOULD DEVELOP IN THE HWY 20
CORRIDOR FROM DUBUQUE ON EAST WITH A CHANGE OVER POSSIBLE.
AN UPDATE REFLECTED ALL THIS WILL BE AVAILABLE SHORTLY.
..08..
&&
.PREV DISCUSSION... /ISSUED 541 AM CST FRI DEC 30 2011/
AVIATION...
SURFACE LOW NEAR KPEA WILL MOV EAST SOUTHEAST AND PASS NEAR KC75
ARND 21Z/30. MVFR TO VFR CONDITIONS WILL BE SEEN AT ALL TAF SITES
WITH BRIEF PERIODS OF IFR LIKELY AT KCID/KDBQ/KMLI. COLD AIR ON
THE BACKSIDE OF THE STORM IS EXPECTED TO ALLOW A RASN MIX AT ALL
TAF SITES AFT 20Z/30 THAT MAY CHANGE TO ALL SN AT KCID/KDBQ. MVFR
CONDITIONS ARND 00Z/31 WILL IMPROVE TO VFR BY 06Z/31.
.08..
PREV DISCUSSION... /ISSUED 316 AM CST FRI DEC 30 2011/
SYNOPSIS...
06Z SFC ANALYSIS HAS A SFC LOW BETWEEN KDNS AND KADU WITH A WARM
FRONT RUNNING EAST TO KC75 AND KPNT. A INVERTED TROF RAN INTO
ANOTHER WARM FRONT IN NORTHEAST SOUTH DAKOTA AND THEN ANOTHER SFC
LOW NORTHEAST OF KBIS. DEW POINTS WERE GENERALLY IN THE 30S WITH
40S FROM THE LOWER MISSISSIPPI VALLEY INTO THE LOWER OHIO VALLEY.
RADAR TRENDS SHOW A BAND OF WAA PRECIPITATION FROM NORTHEAST
IOWA INTO NORTHERN ILLINOIS WITH ANOTHER DEVELOPING FROM CENTRAL
IOWA INTO CENTRAL ILLINOIS.
SHORT TERM...TODAY AND TONIGHT
A COMBINATION OF NOWCASTING TOOLS AND RUC TRENDS WERE USED TO
HANDLE FOR TODAY.
THE RUC 300K THETA SFC IN FORCING AND CONDENSATION PRESSURE
DEFICITS DEPICTS QUITE WELL WHAT IS CURRENTLY GOING ON. THE
INITIAL BAND OF WAA PRECIPITATION WILL ROTATE OUT OF THE CWFA BY
12Z. A NEW BAND OF WAA PRECIPITATION DEVELOPING OVER THE CWFA WILL
MOVE ACROSS THE NORTHERN THIRD OF THE CWFA BETWEEN 6 AND 9 AM. WBZ
TEMPERATURES AT THE SFC AND 925MB RISE THE REMAINDER OF THE NIGHT
AND DURING THE MORNING SO THE PRECIPITATION WILL BE ALL RAIN
EXCEPT IN THE HWY 20 CORRIDOR WHERE A MIX IS EXPECTED TO PERSIST
DURING THE MORNING.
LIFT TOOL INDICATES CONVECTIVE PRECIPITATION DEVELOPING ALONG AND
SOUTH OF I-80 THIS MORNING AND RADAR TRENDS DO SUGGEST THIS IS
OCCURRING.
BY MID DAY THE SFC LOW SHOULD BE OVER THE EASTERN CWFA JUST SOUTH
OF I-80 WITH A DEFORMATION ZONE SETTING UP ACROSS THE NORTHERN
THIRD OF THE CWFA. WBZ TEMPERATURES AT THE SFC AND 925MB FROM MID
DAY THROUGH MID AFTERNOON ARE ABOVE 34 DEGREES SO PRECIPITATION
WILL BE ALL RAIN ACROSS THE CWFA.
WRF TRENDS...ASSUMING THEY ARE CORRECT...INDICATE WBZ TEMPERATURES
DROPPING BACK TO 32 DEGREES OR LOWER FROM 3 TO 6 PM INDICATING A
MIX REDEVELOPING NORTH OF HWY 30 WITH A POSSIBLE CHANGE OVER TO
ALL SNOW IN THE HWY 20 CORRIDOR. SNOW ACCUMULATIONS TODAY ARE
EXPECTED TO BE AN INCH OR LESS.
TONIGHT...WRF TRENDS INDICATE PRECIPITATION LINGERING INTO THE
EVENING HOURS ACROSS THE EASTERN CWFA. WBZ TEMPERATURES INDICATE A
MIX WITH POSSIBLY SOME LIGHT SNOW IN THE HWY 20 CORRIDOR EAST OF
DUBUQUE. HOWEVER...CONDENSATION PRESSURE DEFICITS RISE RAPIDLY
DURING THE EVENING WITH THE FORCING SHUTTING DOWN. THUS ANY SNOW
ACCUMULATION SHOULD BE A DUSTING AT BEST.
08..
LONG TERM...SATURDAY THROUGH THURSDAY...
THE UPS AND DOWNS MORE ASSOCIATED WITH FALL WEATHER WILL DOMINATE
THE EXTENDED FORECAST. SATURDAY SHOULD BE VERY MILD ONCE AGAIN...AS
A VERY STRONG SHORT WAVE DIGS INTO THE PLAINS AND RAPIDLY DROPS THE
SURFACE PRESSURE OVER THE MIDWEST. THIS WILL DRAW SOUTHERLY WINDS UP
OVER THE CWA...WHICH WILL BE MOST CERTAINLY GUSTY AT TIMES. THE DAY
SHOULD SHOULD SEE PASSING MID CLOUDS...BUT WITH THE GUSTY WINDS AND
SEASONALLY DEEP MIXING...IT SEEMS PRUDENT TO GO ABOVE GUIDANCE FOR
HIGHS. THUS...WILL STAY CLOSE TO THE PREVIOUS FORECAST AND GO MID
40S NORTHEAST TO MID 50S SOUTHWEST FOR HIGHS. LOW PRESSURE SHOULD
RAPIDLY SHIFT NORTHEAST INTO THE GREAT LAKES...WITH STRONG HIGH
PRESSURE RAPIDLY MOVING INTO THE GREAT PLAINS. WINDS JUST ALOFT WILL
INCREASE TO 40 TO 50 KTS FROM THE NORTHWEST...BRINGING IN STRONG CAA
SATURDAY NIGHT AND SUNDAY. WINDS SHOULD BE PUSHING ADVISORY DURING
THIS PERIOD...WITH SUSTAINED WINDS EASILY SEEING AROUND 25
MPH...POSSIBLY 30...AND GUSTS OF 40 TO 45 LIKELY. WILL HIGHLIGHT
THIS IN THE HWO. AFTER A SLIGHT TO LOW CHANCE FOR RAIN...POSSIBLY
MIXING WITH SNOW NORTHWEST SATURDAY NIGHT...ALL OF WHICH SEEMS LIGHT
AND NON HAZARDOUS...WE WILL ONCE AGAIN GO INTO A DRY PATTERN THE
REMAINING EXTENDED FORECAST. THUS...THE WIND AND COLD AIR IS THE
MAIN STORY FOLLOWING TODAYS PCPN EVENT. WITH TEMPERATURES ALOFT
CRASHING DOWN INTO THE -12 TO -17 RANGE AT 850MB...WE WILL BE SEEING
THE COLDEST WEATHER IN MANY WEEKS. LOOK FOR SLOWLY FALLING
TEMPERATURES IN THE LOWER TO MID 30S SUNDAY...THEN LOWS IN THE TEENS
SUNDAY NIGHT. TEMPS WILL ONLY LIKELY RISE TO THE LOWER 20S NORTH TO
UPPER 20S SOUTHWEST MONDAY WHICH WILL BE THE COLDEST DAY IN THIS
STRETCH. WHILE SHARPLY COLDER THAN LATELY...THESE TEMPERATURES ARE
CLOSER TO NORMAL THAN THE RECENT MILD TEMPERATURES. A CHILLY NIGHT
MONDAY NIGHT WITH LOWS IN THE 11 TO 18 RANGE FROM NORTH TO SOUTH IS
EXPECTED TO GIVE WAY TO WIDESPREAD MILDER AIR AGAIN NEXT WEEK.
GLOBAL MODELS AGREE ON SHIFTING THE COLD HIGH PRESSURE EAST
TUESDAY...ALLOWING SEVERAL DAYS OF SOUTHWEST FLOW FOR THE MID TO
LATE WEEK. THUS...LOOK FOR ANOTHER STAIR STEP UPWARD ON
TEMPERATURES...LEADING TO ANOTHER MILD WEDNESDAY AND THURSDAY. WE
HAVE GONE WITH MID 30S TO AROUND 40 WEDNESDAY AND AND LOWER TO MID
40S THURSDAY. IT DOES APPEAR THAT WE MAY NEED TO INCREASE THESE
TEMPERATURES EVEN FURTHER...AS WE WILL LIKELY HAVE LITTLE MIDWESTERN
SNOW COVER AROUND TO HOLD SHALLOW COLD AIR IN PLACE.
ERVIN..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
541 AM CST FRI DEC 30 2011
.AVIATION...
SURFACE LOW NEAR KPEA WILL MOV EAST SOUTHEAST AND PASS NEAR KC75
ARND 21Z/30. MVFR TO VFR CONDITIONS WILL BE SEEN AT ALL TAF SITES
WITH BRIEF PERIODS OF IFR LIKELY AT KCID/KDBQ/KMLI. COLD AIR ON
THE BACKSIDE OF THE STORM IS EXPECTED TO ALLOW A RASN MIX AT ALL
TAF SITES AFT 20Z/30 THAT MAY CHANGE TO ALL SN AT KCID/KDBQ. MVFR
CONDITIONS ARND 00Z/31 WILL IMPROVE TO VFR BY 06Z/31.
..08..
&&
.PREV DISCUSSION... /ISSUED 316 AM CST FRI DEC 30 2011/
SYNOPSIS...
06Z SFC ANALYSIS HAS A SFC LOW BETWEEN KDNS AND KADU WITH A WARM
FRONT RUNNING EAST TO KC75 AND KPNT. A INVERTED TROF RAN INTO
ANOTHER WARM FRONT IN NORTHEAST SOUTH DAKOTA AND THEN ANOTHER SFC
LOW NORTHEAST OF KBIS. DEW POINTS WERE GENERALLY IN THE 30S WITH
40S FROM THE LOWER MISSISSIPPI VALLEY INTO THE LOWER OHIO VALLEY.
RADAR TRENDS SHOW A BAND OF WAA PRECIPITATION FROM NORTHEAST
IOWA INTO NORTHERN ILLINOIS WITH ANOTHER DEVELOPING FROM CENTRAL
IOWA INTO CENTRAL ILLINOIS.
SHORT TERM...TODAY AND TONIGHT
A COMBINATION OF NOWCASTING TOOLS AND RUC TRENDS WERE USED TO
HANDLE FOR TODAY.
THE RUC 300K THETA SFC IN FORCING AND CONDENSATION PRESSURE
DEFICITS DEPICTS QUITE WELL WHAT IS CURRENTLY GOING ON. THE
INITIAL BAND OF WAA PRECIPITATION WILL ROTATE OUT OF THE CWFA BY
12Z. A NEW BAND OF WAA PRECIPITATION DEVELOPING OVER THE CWFA WILL
MOVE ACROSS THE NORTHERN THIRD OF THE CWFA BETWEEN 6 AND 9 AM. WBZ
TEMPERATURES AT THE SFC AND 925MB RISE THE REMAINDER OF THE NIGHT
AND DURING THE MORNING SO THE PRECIPITATION WILL BE ALL RAIN
EXCEPT IN THE HWY 20 CORRIDOR WHERE A MIX IS EXPECTED TO PERSIST
DURING THE MORNING.
LIFT TOOL INDICATES CONVECTIVE PRECIPITATION DEVELOPING ALONG AND
SOUTH OF I-80 THIS MORNING AND RADAR TRENDS DO SUGGEST THIS IS
OCCURRING.
BY MID DAY THE SFC LOW SHOULD BE OVER THE EASTERN CWFA JUST SOUTH
OF I-80 WITH A DEFORMATION ZONE SETTING UP ACROSS THE NORTHERN
THIRD OF THE CWFA. WBZ TEMPERATURES AT THE SFC AND 925MB FROM MID
DAY THROUGH MID AFTERNOON ARE ABOVE 34 DEGREES SO PRECIPITATION
WILL BE ALL RAIN ACROSS THE CWFA.
WRF TRENDS...ASSUMING THEY ARE CORRECT...INDICATE WBZ TEMPERATURES
DROPPING BACK TO 32 DEGREES OR LOWER FROM 3 TO 6 PM INDICATING A
MIX REDEVELOPING NORTH OF HWY 30 WITH A POSSIBLE CHANGE OVER TO
ALL SNOW IN THE HWY 20 CORRIDOR. SNOW ACCUMULATIONS TODAY ARE
EXPECTED TO BE AN INCH OR LESS.
TONIGHT...WRF TRENDS INDICATE PRECIPITATION LINGERING INTO THE
EVENING HOURS ACROSS THE EASTERN CWFA. WBZ TEMPERATURES INDICATE A
MIX WITH POSSIBLY SOME LIGHT SNOW IN THE HWY 20 CORRIDOR EAST OF
DUBUQUE. HOWEVER...CONDENSATION PRESSURE DEFICITS RISE RAPIDLY
DURING THE EVENING WITH THE FORCING SHUTTING DOWN. THUS ANY SNOW
ACCUMULATION SHOULD BE A DUSTING AT BEST.
.08..
LONG TERM...SATURDAY THROUGH THURSDAY...
THE UPS AND DOWNS MORE ASSOCIATED WITH FALL WEATHER WILL DOMINATE
THE EXTENDED FORECAST. SATURDAY SHOULD BE VERY MILD ONCE AGAIN...AS
A VERY STRONG SHORT WAVE DIGS INTO THE PLAINS AND RAPIDLY DROPS THE
SURFACE PRESSURE OVER THE MIDWEST. THIS WILL DRAW SOUTHERLY WINDS UP
OVER THE CWA...WHICH WILL BE MOST CERTAINLY GUSTY AT TIMES. THE DAY
SHOULD SHOULD SEE PASSING MID CLOUDS...BUT WITH THE GUSTY WINDS AND
SEASONALLY DEEP MIXING...IT SEEMS PRUDENT TO GO ABOVE GUIDANCE FOR
HIGHS. THUS...WILL STAY CLOSE TO THE PREVIOUS FORECAST AND GO MID
40S NORTHEAST TO MID 50S SOUTHWEST FOR HIGHS. LOW PRESSURE SHOULD
RAPIDLY SHIFT NORTHEAST INTO THE GREAT LAKES...WITH STRONG HIGH
PRESSURE RAPIDLY MOVING INTO THE GREAT PLAINS. WINDS JUST ALOFT WILL
INCREASE TO 40 TO 50 KTS FROM THE NORTHWEST...BRINGING IN STRONG CAA
SATURDAY NIGHT AND SUNDAY. WINDS SHOULD BE PUSHING ADVISORY DURING
THIS PERIOD...WITH SUSTAINED WINDS EASILY SEEING AROUND 25
MPH...POSSIBLY 30...AND GUSTS OF 40 TO 45 LIKELY. WILL HIGHLIGHT
THIS IN THE HWO. AFTER A SLIGHT TO LOW CHANCE FOR RAIN...POSSIBLY
MIXING WITH SNOW NORTHWEST SATURDAY NIGHT...ALL OF WHICH SEEMS LIGHT
AND NON HAZARDOUS...WE WILL ONCE AGAIN GO INTO A DRY PATTERN THE
REMAINING EXTENDED FORECAST. THUS...THE WIND AND COLD AIR IS THE
MAIN STORY FOLLOWING TODAYS PCPN EVENT. WITH TEMPERATURES ALOFT
CRASHING DOWN INTO THE -12 TO -17 RANGE AT 850MB...WE WILL BE SEEING
THE COLDEST WEATHER IN MANY WEEKS. LOOK FOR SLOWLY FALLING
TEMPERATURES IN THE LOWER TO MID 30S SUNDAY...THEN LOWS IN THE TEENS
SUNDAY NIGHT. TEMPS WILL ONLY LIKELY RISE TO THE LOWER 20S NORTH TO
UPPER 20S SOUTHWEST MONDAY WHICH WILL BE THE COLDEST DAY IN THIS
STRETCH. WHILE SHARPLY COLDER THAN LATELY...THESE TEMPERATURES ARE
CLOSER TO NORMAL THAN THE RECENT MILD TEMPERATURES. A CHILLY NIGHT
MONDAY NIGHT WITH LOWS IN THE 11 TO 18 RANGE FROM NORTH TO SOUTH IS
EXPECTED TO GIVE WAY TO WIDESPREAD MILDER AIR AGAIN NEXT WEEK.
GLOBAL MODELS AGREE ON SHIFTING THE COLD HIGH PRESSURE EAST
TUESDAY...ALLOWING SEVERAL DAYS OF SOUTHWEST FLOW FOR THE MID TO
LATE WEEK. THUS...LOOK FOR ANOTHER STAIR STEP UPWARD ON
TEMPERATURES...LEADING TO ANOTHER MILD WEDNESDAY AND THURSDAY. WE
HAVE GONE WITH MID 30S TO AROUND 40 WEDNESDAY AND AND LOWER TO MID
40S THURSDAY. IT DOES APPEAR THAT WE MAY NEED TO INCREASE THESE
TEMPERATURES EVEN FURTHER...AS WE WILL LIKELY HAVE LITTLE MIDWESTERN
SNOW COVER AROUND TO HOLD SHALLOW COLD AIR IN PLACE.
.ERVIN..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
952 PM CST SAT DEC 31 2011
.AVIATION...
FOR THE 06Z TAF ISSUANCE...
VFR CONDITIONS WILL PREVAIL THROUGH SUNDAY. AN UPPER LEVEL RIDGE
OVER THE WESTERN UNITED STATES WILL PROPAGATE SLOWLY EAST TOWARD
THE CENTRAL ROCKIES BY MONDAY. AT THE SURFACE, HIGH PRESSURE WILL
BUILD FROM THE NORTHERN ROCKIES INTO THE CENTRAL PLAINS SUNDAY AND
SUNDAY NIGHT. NORTHWEST WINDS WILL DIMINISH TO AROUND 10 KNOTS
BEFORE SUNRISE. PATCHY THIN CIRRUS CLOUDS AOA 250 WILL SPILL OVER
THE WESTERN UNITED STATES RIDGE INTO THE CENTRAL PLAINS SUNDAY.
&&
.PREV DISCUSSION... /ISSUED 659 PM CST SAT DEC 31 2011/
SYNOPSIS...
300 HPA 12Z MAP ANALYSIS SHOWS A STRONG 140-145 KT JET EXTENDING ACROSS
THE PACIFIC NORTHWEST AND EASTWARDS ACROSS THE GREAT BASIN. AT 500 HPA,
STRONG COLD AIR ADVECTION WITH TEMPERATURES CHANGES IN THE 5 TO 10 DEGREE
C RANGE WERE NOTED IN COMPARING THE 00Z TO 12Z MAPS ACROSS THE ROCKIES.
THE COLDEST AIR AT 500 HPA - AROUND -35 DEG C - EXTENDED FROM BRITISH
COLUMBIA SOUTH INTO MONTANA. SIMILAR CHANGES IN TEMPERATURES WERE ALSO
NOTED AT 700 AND 750 HPA WELL UPSTREAM OF KANSAS. ACROSS THE PLAINS,
A WARM AND DRY PLUME PREVAILED AT 700/850 HPA. AT THE SURFACE, A COLD
FRONT WAS PUSHING ACROSS THE HIGH PLAINS WITH VERY STRONG WINDS (SEVERE,
IN FACT) WERE NOTED IN THE WAKE OF THE BOUNDARY. -SUGDEN
DISCUSSION...
DAYS 1-2...
NEW YEARS EVE:
SHORT TERM CONCERN IS WINDS. SEVERAL REPORTS OF 58+ MPH WINDS WERE NOTED
ACROSS NE COLORADO/NW KANSAS EARLY THIS AFTERNOON. HRRR GUIDANCE STILL
SUPPORTS WINDS (EITHER SUSTAINED OR GUSTS) MEETING WARNING CRITERIA
LATE THIS AFTERNOON AND INTO THE EARLY EVENING. WINDS SHOULD DECREASE
SIGNIFICANTLY IN THE 8-9 PM CST TIME RANGE. SECOND CONCERN WAS PRECIPITATION.
HAVE 15 POPS IN THE GRIDS AS COLD POOL MOVES ACROSS NORTH CENTRAL KANSAS
AND THERE COULD BE ENOUGH INSTABILITY FOR A FEW SHOWERS. HRRR FORECAST
COMPOSITE RADAR IMAGERY AS ALSO SUGGESTING AS SUCH. WITH THE EXCEPTION
OF CLOUDS ACROSS THE INTERSTATE 70 CORRIDOR, RELATIVELY CLEAR SKY CONDITIONS
ARE EXPECTED. TEMPERATURES OF UPPER TEENS DEG F WEST TO AROUND 30 DEG
F EAST ARE EXPECTED THROUGH THE OVERNIGHT HOURS.
NEW YEARS DAY:
COOLER TEMPERATURES BUT SEASONABLE OVERALL WILL RING IN NEW YEAR TOMORROW.
WITH THE AFOREMENTIONED STRONG COLD AIR ADVECTION, 850 HPA TEMPERATURES
WILL DECREASE TO THE -1 TO -2 DEG C RANGE. THIS SUPPORTS LOW 40S DEG
F ACROSS MUCH OF WEST CENTRAL AND SOUTHWEST KANSAS. THE EXCEPTION IS
TOWARDS SOUTH CENTRAL KANSAS WHERE A LARGER MIXING LAYER WILL SUPPORT
SURFACE TEMPERATURES IN THE UPPER 40S TO AROUND 50 DEG F. WITH DRY NORTHWEST
FLOW ALOFT PREVAILING IN THE WAKE OF A DEPARTING TROUGH, POPS WILL REMAIN
AT ZERO THROUGH THE FIRST DAY OF 2012.
SUNDAY EVENING:
STRONG HIGH PRESSURE OF AROUND 1040 HPA WILL SLIDE ACROSS THE PLAINS
OVERNIGHT SUNDAY. THIS WILL ALLOW FOR LIGHT WINDS. FORECAST SOUNDINGS
SHOW A FAIRLY DRY PROFILE, SO THINK A GOOD RADIATIONAL COOLING NIGHT
WILL OCCUR. LOW TEENS DEG F IS EXPECTED ACROSS THE NORTHWEST COUNTIES
TOWARDS SCOTT CITY WITH AROUND 20 DEG F EXPECTED TOWARDS MEDICINE LODGE.
AGAIN, NOT EXPECTING ANY PRECIPITATION WITH INCREASING 500 HPA ALOFT
AND HIGH PRESSURE AT THE SURFACE.
MONDAY:
500 HPA HEIGHTS OF AROUND 575-580 DM ARE EXPECTED MONDAY. SFC WINDS
WILL TURN MORE SOUTHERLY MONDAY AFTERNOON ON THE WESTERN SIDE OF THE
DEPARTING SURFACE HIGH. TEMPERATURES WILL REMAIN SEASONABLE MONDAY WITH
HIGHS IN THE 40S DEG F FOR MUCH OF SOUTHWEST KANSAS. WILL KEEP POPS
AT ZERO MONDAY WITH HIGH PRESSURE ALOFT/SUBSIDENCE OCCURRING ACROSS
WESTERN KANSAS. -SUGDEN
DAYS 3-7...
MUCH OF THE SENSIBLE WEATHER ACROSS SOUTHWEST KANSAS IN THE MEDIUM RANGE
WILL BE INFLUENCE BY SUBSTANTIAL RIDGING AS AN ANOMALOUS 585 DAM H5
HIGH BUILDS ACROSS THE SOUTHWEST. THIS WILL LEAD TO A FAIRLY SIGNIFICANT
WARMING OF THE LOWER TROPOSPHERE YIELDING HIGHS IN THE 50S TO LOWER
60S WEDNESDAY AND THURSDAY. BY THE END OF THE WEEK...THE GLOBAL MODELS
SUGGEST AN EROSION OF THE RIDGE WITH LOWERING HEIGHTS ACROSS THE NORTHWESTERN
CONUS. THE DETAILS OF THE PATTERN CHANGE ARE STILL RATHER UNCLEAR...BUT
AS WE HEAD INTO THE DAY 7 PORTION OF THIS FORECAST...THERE ARE SOME
SIGNALS IN THE GLOBAL MODELS (PARTICULARLY THE ECMWF) OF STORM DEVELOPMENT
OVER THE ROCKIES/PLAINS. FOR THIS UPDATE CYCLE...A DRY FORECAST IS
IN THE CARDS THROUGH SATURDAY. -UMSCHEID
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 55 22 43 18 / 0 0 0 0
GCK 53 22 40 16 / 0 0 0 0
EHA 59 19 42 19 / 0 0 0 0
LBL 62 20 42 18 / 0 0 0 0
HYS 55 25 43 16 / 20 20 0 0
P28 68 28 49 21 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
FN01/01/01
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
659 PM CST SAT DEC 31 2011
.AVIATION...
FOR THE 00Z TAF ISSUANCE...
A STRONG UPPER LEVEL TROUGH IN NORTH CENTRAL KANSAS WILL MOVE
RAPIDLY EAST INTO THE UPPER MIDWEST BY SUNRISE SUNDAY, AND SURFACE
HIGH PRESSURE WILL BUILD IN THE CENTRAL PLAINS. VERY STRONG
NORTHWEST WINDS WITH GUSTS IN EXCESS OF 50 KNOTS WILL DIMINISH TO
LESS THAN 25 KNOTS BY 03Z LESS THAN 10 KNOTS BY 11Z. CEILINGS NEAR
020 IN HYS AND DDC WILL IMPROVE TO ONLY A FEW CLOUDS AOA 100 BY
01Z IN DDC AND 03Z IN HYS. VFR CONDITIONS WILL PREVAIL SUNDAY WITH
ONLY A FEW CIRRUS CLOUDS AROUND 250.
&&
.PREV DISCUSSION... /ISSUED 222 PM CST SAT DEC 31 2011/
SYNOPSIS...
300 HPA 12Z MAP ANALYSIS SHOWS A STRONG 140-145 KT JET EXTENDING ACROSS
THE PACIFIC NORTHWEST AND EASTWARDS ACROSS THE GREAT BASIN. AT 500 HPA,
STRONG COLD AIR ADVECTION WITH TEMPERATURES CHANGES IN THE 5 TO 10 DEGREE
C RANGE WERE NOTED IN COMPARING THE 00Z TO 12Z MAPS ACROSS THE ROCKIES.
THE COLDEST AIR AT 500 HPA - AROUND -35 DEG C - EXTENDED FROM BRITISH
COLUMBIA SOUTH INTO MONTANA. SIMILAR CHANGES IN TEMPERATURES WERE ALSO
NOTED AT 700 AND 750 HPA WELL UPSTREAM OF KANSAS. ACROSS THE PLAINS,
A WARM AND DRY PLUME PREVAILED AT 700/850 HPA. AT THE SURFACE, A COLD
FRONT WAS PUSHING ACROSS THE HIGH PLAINS WITH VERY STRONG WINDS (SEVERE,
IN FACT) WERE NOTED IN THE WAKE OF THE BOUNDARY. -SUGDEN
DISCUSSION...
DAYS 1-2...
NEW YEARS EVE:
SHORT TERM CONCERN IS WINDS. SEVERAL REPORTS OF 58+ MPH WINDS WERE NOTED
ACROSS NE COLORADO/NW KANSAS EARLY THIS AFTERNOON. HRRR GUIDANCE STILL
SUPPORTS WINDS (EITHER SUSTAINED OR GUSTS) MEETING WARNING CRITERIA
LATE THIS AFTERNOON AND INTO THE EARLY EVENING. WINDS SHOULD DECREASE
SIGNIFICANTLY IN THE 8-9 PM CST TIME RANGE. SECOND CONCERN WAS PRECIPITATION.
HAVE 15 POPS IN THE GRIDS AS COLD POOL MOVES ACROSS NORTH CENTRAL KANSAS
AND THERE COULD BE ENOUGH INSTABILITY FOR A FEW SHOWERS. HRRR FORECAST
COMPOSITE RADAR IMAGERY AS ALSO SUGGESTING AS SUCH. WITH THE EXCEPTION
OF CLOUDS ACROSS THE INTERSTATE 70 CORRIDOR, RELATIVELY CLEAR SKY CONDITIONS
ARE EXPECTED. TEMPERATURES OF UPPER TEENS DEG F WEST TO AROUND 30 DEG
F EAST ARE EXPECTED THROUGH THE OVERNIGHT HOURS.
NEW YEARS DAY:
COOLER TEMPERATURES BUT SEASONABLE OVERALL WILL RING IN NEW YEAR TOMORROW.
WITH THE AFOREMENTIONED STRONG COLD AIR ADVECTION, 850 HPA TEMPERATURES
WILL DECREASE TO THE -1 TO -2 DEG C RANGE. THIS SUPPORTS LOW 40S DEG
F ACROSS MUCH OF WEST CENTRAL AND SOUTHWEST KANSAS. THE EXCEPTION IS
TOWARDS SOUTH CENTRAL KANSAS WHERE A LARGER MIXING LAYER WILL SUPPORT
SURFACE TEMPERATURES IN THE UPPER 40S TO AROUND 50 DEG F. WITH DRY NORTHWEST
FLOW ALOFT PREVAILING IN THE WAKE OF A DEPARTING TROUGH, POPS WILL REMAIN
AT ZERO THROUGH THE FIRST DAY OF 2012.
SUNDAY EVENING:
STRONG HIGH PRESSURE OF AROUND 1040 HPA WILL SLIDE ACROSS THE PLAINS
OVERNIGHT SUNDAY. THIS WILL ALLOW FOR LIGHT WINDS. FORECAST SOUNDINGS
SHOW A FAIRLY DRY PROFILE, SO THINK A GOOD RADIATIONAL COOLING NIGHT
WILL OCCUR. LOW TEENS DEG F IS EXPECTED ACROSS THE NORTHWEST COUNTIES
TOWARDS SCOTT CITY WITH AROUND 20 DEG F EXPECTED TOWARDS MEDICINE LODGE.
AGAIN, NOT EXPECTING ANY PRECIPITATION WITH INCREASING 500 HPA ALOFT
AND HIGH PRESSURE AT THE SURFACE.
MONDAY:
500 HPA HEIGHTS OF AROUND 575-580 DM ARE EXPECTED MONDAY. SFC WINDS
WILL TURN MORE SOUTHERLY MONDAY AFTERNOON ON THE WESTERN SIDE OF THE
DEPARTING SURFACE HIGH. TEMPERATURES WILL REMAIN SEASONABLE MONDAY WITH
HIGHS IN THE 40S DEG F FOR MUCH OF SOUTHWEST KANSAS. WILL KEEP POPS
AT ZERO MONDAY WITH HIGH PRESSURE ALOFT/SUBSIDENCE OCCURRING ACROSS
WESTERN KANSAS. -SUGDEN
DAYS 3-7...
MUCH OF THE SENSIBLE WEATHER ACROSS SOUTHWEST KANSAS IN THE MEDIUM RANGE
WILL BE INFLUENCE BY SUBSTANTIAL RIDGING AS AN ANOMALOUS 585 DAM H5
HIGH BUILDS ACROSS THE SOUTHWEST. THIS WILL LEAD TO A FAIRLY SIGNIFICANT
WARMING OF THE LOWER TROPOSPHERE YIELDING HIGHS IN THE 50S TO LOWER
60S WEDNESDAY AND THURSDAY. BY THE END OF THE WEEK...THE GLOBAL MODELS
SUGGEST AN EROSION OF THE RIDGE WITH LOWERING HEIGHTS ACROSS THE NORTHWESTERN
CONUS. THE DETAILS OF THE PATTERN CHANGE ARE STILL RATHER UNCLEAR...BUT
AS WE HEAD INTO THE DAY 7 PORTION OF THIS FORECAST...THERE ARE SOME
SIGNALS IN THE GLOBAL MODELS (PARTICULARLY THE ECMWF) OF STORM DEVELOPMENT
OVER THE ROCKIES/PLAINS. FOR THIS UPDATE CYCLE...A DRY FORECAST IS
IN THE CARDS THROUGH SATURDAY. -UMSCHEID
AVIATION...
FOR THE 18Z TAF ISSUANCE...HIGH WIND EVENT WILL AFFECT GCK, DDC, HYS THIS
AFTERNOON THROUGH THIS EVENING. THE THINKING IS THAT THE PEAK OF THE
HIGH WIND EVENT WILL BE FROM ROUGHLY 21Z TO 00Z WHEN FREQUENT GUSTS
OF 45 TO 50 KNOTS CAN BE EXPECTED FROM THE NORTHWEST. A FEW SCATTERED
SHOWERS WILL LIKELY DEVELOP BEHIND THE LOW AFFECTING THE HYS TERMINAL
AND AS SUCH HAVE INSERTED VCSH EARLY THIS EVENING FOR A FEW HOURS.
THERE IS NOT EXPECTED TO BE A REDUCTION IN VISIBILITY/CEILING INTO
THE VFR CATEGORY...BUT SOME STRATUS WITH A 2000 TO 3000 FOOT CEILING
IS EXPECTED AT HYS AND PERHAPS DDC FOR A FEW HOURS. LATE TONIGHT
WINDS WILL DECREASE TO BELOW 15 KNOTS REMAINING OUT OF THE
NORTHWEST. -UMSCHEID
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 55 22 43 18 / 0 0 0 0
GCK 53 22 40 16 / 0 0 0 0
EHA 59 19 42 19 / 0 0 0 0
LBL 62 20 42 18 / 0 0 0 0
HYS 55 25 43 16 / 20 20 0 0
P28 68 28 49 21 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING UNTIL 9 PM CST /8 PM MST/ THIS EVENING FOR
KSZ030-031-043>046-061>066-074>081-084>090.
&&
$$
FN01/01/01
AREA FORECAST DISCUSSION
NWS CARIBOU ME
500 AM EST SUN JAN 1 2012
.SYNOPSIS...
HIGH PRESSURE WILL BUILD BRIEFLY ACROSS THE REGION TODAY. AN OCCLUDED
FRONT WILL APPROACH FROM THE WEST THIS EVENING AND CROSS THE
REGION EARLY MONDAY MORNING...FOLLOWED BY A STRONG ARCTIC FRONT
LATE MONDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
CHALLENGE WILL BE TONIGHT W/THE POTENTIAL FOR ANOTHER ROUND OF
FREEZING PRECIP.
CLOUDS HANGING ON ACROSS MUCH OF THE CWA THIS MORNING AS EVIDENT
FROM THE LATEST IR SATL IMAGERY. MOISTURE HANGING ON BELOW 925MBS
W/AIRMASS DRY ABOVE THIS LAYER. INVERSION IS IN PLACE AND IS SHOWN
TO HANG ON FOR A WHILE THIS MORNING PER THE LATEST RUC SOUNDINGS
WHICH IS SUPPORT BY THE 00Z NAM. A W FLOW TAKES OVER LATER THIS
MORNING HELPING TO ERODE CLOUDS ACROSS THE CENTRAL AND DOWNEAST
REGION. ACROSS THE NORTH AND WEST, CLOUDS COULD HANG ON LONGER
W/INVERSION HANGING AS SHOWN BY THE SOUNDINGS SHOWING MOISTURE
STAYING TRAPPED AT AROUND 900MBS. DECIDED TO HANG ON TO SOME
CLOUDS LONGER ACROSS THE NORTHERN AND WESTERN AREAS INTO EARLY
AFTERNOON W/MORE SUN ACROSS THE CENTRAL AND DOWNEAST AREAS.
OBVIOUSLY THIS WILL PLAY INTO THE MAX TEMPERATURE FCST TODAY.
ADJUSTED THE DAYCREW/S MAXES FOR TODAY UPWARD ACROSS THE CWA
W/UPPER 20S TO LOWER 30S ACROSS THE NORTH AND WEST AND UPPER 30S
TO LOWER 40S FOR CENTRAL AND DOWNEAST AREAS.
TONIGHT COULD BE INTERESTING AS AN OCCLUDED FRONT APCHS FROM THE W
LATER TONIGHT W/PRECIP MOVING IN LATER TONIGHT. LATEST MDL
SOUNDINGS SHOW TEMPERATURES TO BE WARM ENOUGH ACROSS THE CENTRAL
AND DOWNEAST AREAS FOR MAINLY RAIN. ACROSS THE NORTHERN AND
WESTERN AREAS, THINGS LOOK TO BE DIFFERENT AS TEMPERATURES COOL
OFF EARLY TONIGHT AND THEN LEVEL OFF BEFORE RISING WELL AFTER
MIDNIGHT. WX ELEMENT IN THESE AREAS WILL BE IN THE FORM OF SOME
SNOW BUT A TRANSITION TO FREEZING PRECIP IS POSSIBLE. THE NAM AND GFS
BOTH SHOW A WARM LAYER SETTING UP AGAIN FROM 925-850MBS W/A COLD
LAYER AT THE SFC. THIS WILL SET THE STAGE FOR ANOTHER FRZA EVENT.
THE TIMING LOOKS TO BE BRIEF W/FZRA/FZDZ. THERE ALSO LOOKS TO BE A
PERIOD OF SLEET POSSIBLE. BEST SNOW ACCUMULATION WILL BE ACROSS
THE FAR NORTH AND WEST MAINLY NORTH AND WEST OF CAR,PQI & HUL. THE
PRECIP FROM THICKNESS TOOL WAS USED FOR THE WX ELEMENT. QPF IS A
BLEND OF HPC/GFS AND THE NAM WHICH SHOWS THE HIGHEST AREAS ACROSS
DOWNEAST AND AND EASTERN SECTIONS. ADDED SOME ICE ACCUMULATION
MAINLY FOR THE NORTH AND WEST W/<.10". DECIDED TO HOLD OFF ON ANY
WINTER WEATHER ADVISORIES AS THIS LOOKS TO BE LATE 2ND PERIOD INTO
THE 3RD PERIOD. THE DAYCREW CAN ASSESS THIS FURTHER W/LATER MODEL
RUNS. THE HWO WILL ADDRESS THIS POTENTIAL.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
THE OCCLUDED FRONT MOVES EAST EARLY MONDAY MORNING WITH STEADY
PRECIPITATION ENDING EARLY. EXPECT MAX TEMPERATURES TO OCCUR EARLY
IN THE DAY BEFORE FALLING A FEW DEGREES DURING THE AFTERNOON AS
SLIGHTLY COOLER FILTERS IN BEHIND THE OCCLUSION. ONCE THE STEADY
PRECIPITATION ENDS MONDAY MORNING IT WILL REMAIN MOSTLY CLOUDY. AN
ARCTIC COLD FRONT WILL APPROACH LATER MONDAY AFTERNOON AND THEN
SWEEP EAST ACROSS THE FA MONDAY NIGHT. THERE WILL BE THE CHANCE
FOR SNOW SHOWERS ACROSS NORTHERN PORTIONS OF THE FA WITH THE
PASSAGE OF THE ARCTIC BOUNDARY...HOWEVER THE BIG STORY WILL BE
THE STRONG COLD ADVECTION LATER MONDAY NIGHT AND TUESDAY.
TEMPERATURES WILL FALL TO ZERO TO 5 ABOVE ZERO ACROSS MUCH OF
NORTHERN MAINE AND LOW TO MID TEENS ACROSS MOST OF DOWNEAST MAINE
BY EARLY TUESDAY MORNING. TEMPERATURES ON TUESDAY WILL NOT RECOVER
MUCH FROM THE EARLY MORNING LOWS WITH HIGHS ONLY EXPECTED TO BE IN
THE SINGLE DIGITS ABOVE ZERO TO AROUND 10 ABOVE NORTH AND 15 TO 20
DOWNEAST. ALONG WITH THE COLD TEMPERATURES WILL COME THE CHANCE
FOR SOME SNOW SHOWERS OR FLURRIES ACROSS THE NORTH WITH PARTLY
CLOUDY SKIES DOWNEAST.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
IT STILL LOOKS RELATIVELY QUIET THROUGH THE LONG TERM WITH NO BIG
STORMS IN SIGHT. TEMPERATURES WILL REMAIN BELOW NORMAL THROUGH
MUCH OF THE PERIOD. BRISK NORTHWEST FLOW WILL CONTINUE TUESDAY
NIGHT AND WEDNESDAY WITH MAINLY DRY CONDITIONS AS HIGH PRESSURE
MOVES EAST. A WEAK DISTURBANCE WILL CROSS THE REGION THURSDAY
FOLLOWED BY HIGH PRESSURE THURSDAY NIGHT. A CLIPPER TYPE SYSTEM
COULD BRING SOME SNOW SHOWERS TO THE REGION BY THE END OF THE
PERIOD.
&&
.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
NEAR TERM: IFR/MVFR CONDITIONS WILL GO TO VFR LATER THIS MORNING
W/THE NORTHERN TERMINALS HANGING ONTO MVFR CIGS A WHILE LONGER
W/THE INVERSION. VFR THIS EVENING DROPPING BACK TO MVFR LATER
TONIGHT ACROSS THE NORTHERN TERMINALS W/IFR CONDITIONS FOR BGR AND
BHB NEAR OR AFTER 06Z.
SHORT TERM: MVFR CONDITIONS POSSIBLE IN ANY SCATTERED SNOW SHOWERS
MAINLY ACROSS NORTHERN SECTIONS MONDAY AND TUESDAY OTHERWISE
MAINLY VFR.
&&
.MARINE...
NEAR TERM: DECIDED TO GO TO A GALE WARNING STARTING AFTER 06Z AND
CONTINUING INTO MONDAY AS LLVL JET OF 45-50KT HITS THE WATERS.
GUSTS TO HIT 35KTS. WINDS WILL BE TOUGH TO MIX DOWN W/WAA INITIALLY
AND THEN AS THE OCCLUSION MOVES THROUGH SW WINDS WILL HAVE A CHC
TO MIX DOWN AS LLVLS BEGIN TO COOL. DAYCREW/S WAVE HEIGHTS WERE
MATCHING CLOSE THE LATEST SWAN AND WNAWAVE AND DECIDED TO STAY
CLOSE THE CURRENT FCST OF SEAS BUILDING TO 3-6 FT.
SHORT TERM: GALE FORCE CONDITIONS MONDAY INTO MONDAY NIGHT THEN
SCA CONDITIONS ARE EXPECTED TUESDAY INTO WEDNESDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...GALE WARNING FROM 3 AM TO 7 PM EST MONDAY FOR ANZ050>052.
&&
$$
NEAR TERM...HEWITT
SHORT TERM...DUDA
LONG TERM...DUDA
AVIATION...HEWITT
MARINE...HEWITT/DUDA
AREA FORECAST DISCUSSION
NWS CARIBOU ME
415 PM EST FRI DEC 30 2011
.SYNOPSIS...
LOW PRESSURE OVER THE GREAT LAKES WILL WEAKEN TONIGHT WITH
REDEVELOPMENT OFF OF CAPE COD ON SATURDAY. THIS NEW LOW PRESSURE
WILL TRACK EASTWARD THROUGH THE GULF OF MAINE AND THEN SOUTH OF
NOVA SCOTIA BY SATURDAY EVENING. A HIGH PRESSURE RIDGE WILL BUILD
ACROSS THE REGION ON SUNDAY.
&&
.NEAR TERM /THROUGH SATURDAY/...
SHORTWAVE TROUGH FLATTENING UPPER RIDGE ACROSS THE STATE IS
PRODUCING AN AREA OF LIGHT SNOW SHOWERS ACROSS WESTERN MAINE THIS
AFTERNOON. HRRR MODEL INDICATES AS THIS SHORTWAVE TROUGH MOVES
ACROSS DOWNEAST LATE THIS AFTERNOON INTO THIS EVENING, A PERIOD OF
SNOW SHOWERS CAN BE EXPECTED WITH ANY ACCUMULATION LESS THAN AN
INCH.
MODELS IN GOOD AGREEMENT WITH LOW PRESSURE OVER THE GREAT LAKES
FILLING TONIGHT WITH REDEVELOPMENT JUST EAST OF CAPE COD BY SATURDAY
AFTERNOON. THE LOW PRESSURE WILL THEN TRACK EASTWARD AND MOVE SOUTH
OF NOVA SCOTIA BY SATURDAY NIGHT. WITH HIGH PRESSURE EAST OF THE
REGION INSTEAD OF NORTH OF THE STATE, WARM ATLANTIC AIR IN THE
LOWER LEVELS WILL BE ALLOWED TO FLOW NORTHWARD ACROSS THE FORECAST
AREA PRODUCING ANOTHER WINTRY MIX FOR THE REGION. CRITICAL THICKNESS
NOW INDICATING MORE MIX THAN SNOW SO HAVE REDUCE SNOW ACCUMULATION
ACROSS CENTRAL AND NORTHERN SECTIONS BY AROUND AN INCH AND
INCREASE ICE ACCUMULATIONS BY A TENTH OF AN INCH ACROSS CENTRAL
PORTIONS. AT THIS TIME, EXPECT THE AXIS OF HEAVIEST ICE TO OCCUR
30 MILES ON EITHER SIDE OF A LINE FROM GREENVILLE TO HOULTON WHERE
UP TO A QUARTER OF AN INCH MAY ACCUMULATE. MODELS ALSO INDICATING
TEMPERATURES WILL BE SLOW TO RISE ACROSS DOWNEAST SO WILL EXTEND
ADVISORY FROM 7 AM TO NOONTIME SATURDAY.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
THINGS WILL BE WINDING DOWN SATURDAY NIGHT AS THE LOW MOVES OUT OF
THE GULF OF MAINE AND SOUTH OF NOVA SCOTIA. THERE WILL BE SOME
LINGERING FREEZING RAIN IN NORTHERN SECTIONS DURING THE EVENING BUT
COLDER AIR WRAPPING AROUND THE DEPARTING SYSTEM WILL CHANGE THE
PRECIPITATION TO ALL SNOW FROM NORTH TO SOUTH THROUGH THE NIGHT.
SNOWFALL AMOUNTS WILL BE LIGHT...GENERALLY A DUSTING TO AROUND HALF
AN INCH WITH ANOTHER TRACE OF ICE ACCUMULATION.
HIGH PRESSURE WILL BRIEFLY BUILD IN SUNDAY BEFORE ANOTHER LOW
PRESSURE SYSTEM MOVES BY TO OUR NORTH SUNDAY NIGHT AND MONDAY. THIS
WILL BRING ANOTHER ROUND OF SNOW AND RAIN TO THE REGION. THE
RAIN/SNOW LINE WILL BE SOUTH OF HOULTON AND MILLINOCKET WITH THE
IMMEDIATE COAST ALL RAIN BY MONDAY AFTERNOON. EXPECT TEMPERATURES TO
REACH INTO THE 30S DUE TO INCREASING SOUTH FLOW AHEAD OF THE
SYSTEM...BUT A STRONG COLD FRONT WILL PUSH THROUGH THE REGION DURING
THE DAY MONDAY USHERING IN MUCH COLDER AIR FOR THE WORK WEEK.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
COLDER AIR WILL FILTER INTO THE REGION FOR MONDAY NIGHT AND
TUESDAY ACCOMPANIED BY MAINLY CLOUDY SKIES ALONG WITH SCATTERED
SNOW SHOWERS AND FLURRIES DUE TO AN UPPER LEVEL TROUGH LINGERING
IN THE REGION. PRECIPITATION WILL BE CONFINED MAINLY TO NORTHERN
AREAS WHERE A FEW HEAVIER SNOW SHOWERS WILL BE POSSIBLE DUE TO
BANDS SETTING UP OFF THE ST. LAWRENCE. HIGH PRESSURE WILL BRIEFLY
MOVE IN FOR WEDNESDAY RESULTING IN MAINLY SUNNY SKIES AND DRY
CONDITIONS REGION WIDE. HOWEVER TEMPERATURES WILL STRUGGLE TO MAKE
IT OUT OF THE LOW TO MID TEENS NORTH WITH HIGHS DOWNEAST REACHING
THE LOW 20S. HIGH PRESSURE WILL SLIDE OFF TO THE EAST THURSDAY AS
THE NEXT UPPER LEVEL TROUGH APPROACHES THE EAST COAST RESULTING IN
INCREASING CLOUDS ALONG WITH THE SLIGHT CHANCE FOR A FEW FLURRIES
FOR THE END OF THE WEEK. AT THIS POINT ANY SURFACE CYCLOGENESIS
ASSOCIATED WITH THIS TROUGH LOOKS TO TAKE PLACE TOO FAR SOUTH AND
EAST TO AFFECT THE REGION WITH SIGNIFICANT PRECIPITATION.
&&
.AVIATION /21Z FRIDAY THROUGH WEDNESDAY/...
NEAR TERM: VFR CONDITIONS TONIGHT WILL LOWER TO IFR IN A WINTRY
MIX ON SATURDAY. THERE MAY BE A BRIEF PERIOD OF MVFR/IFR IN SNOW
AT KBGR AND KBHB BETWEEN 21Z-02Z AS AN AREA OF SNOW SHOWERS MOVES
ACROSS DOWNEAST.
SHORT TERM: IFR CONDITIONS IN SNOW AND RAIN THROUGH THE FIRST
PART OF SATURDAY NIGHT. PERIODS OF FREEZING RAIN WILL BE POSSIBLE
THROUGH 06Z SUNDAY. CONDITIONS WILL GRADUALLY IMPROVE AFTER
MIDNIGHT AND EXPECT ALL TERMINALS TO BE VFR BY 12Z SUNDAY. A
RETURN TO IFR COMES SUNDAY NIGHT AS SNOW SPREADS OVER THE REGION.
IFR IN SNOW AND RAIN SUNDAY NIGHT AND MONDAY.
BRIEF PERIODS OF MVFR/IFR CONDITIONS WILL BE POSSIBLE MONDAY
NIGHT AND TUESDAY FOR THE NORTHERN SITES DUE TO LINGERING SCATTERED SNOW
SHOWERS AND FLURRIES WITH VFR CONDITIONS PREDOMINATING FOR KBGR
AND KBHB. HIGH PRESSURE WILL BUILD IN WEDNESDAY WITH VFR
CONDITIONS EXPECTED FOR ALL SITES.
&&
.MARINE...
NEAR TERM: AS LOW PRESSURE MOVES THROUGH THE GULF OF MAINE, MINIMAL
SCA CONDITIONS POSSIBLE OVER OUR OUTER WATERS ON SATURDAY.
SHORT TERM: NO HEADLINES ANTICIPATED SATURDAY NIGHT AND SUNDAY AS
HIGH PRESSURE BRIEFLY BUILDS OVER THE WATERS. LOW PRESSURE WILL
MOVE BY TO THE NORTH SUNDAY NIGHT AND MONDAY SO EXPECT WINDS AND
SEAS TO INCREASE THROUGH THE PERIOD. A SMALL CRAFT ADVISORY WILL
LIKELY BE NEEDED WITH GALES A POSSIBILITY. WINDS AND SEAS WILL
CONTINUE TO BE AT SCA LEVELS FOR MONDAY NIGHT AND TUESDAY. SEAS
WILL DIMINISH WEDNESDAY BUT WINDS WILL CONTINUE TO REMAIN NEAR SCA
LEVELS BEFORE DIMINISHING FOR WEDNESDAY NIGHT AND THURSDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY FROM 1 AM TO 7 PM EST SATURDAY FOR
MEZ001>006-010.
WINTER WEATHER ADVISORY FROM 1 AM TO NOON EST SATURDAY FOR
MEZ011-015>017-031-032.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM TO 6 PM EST SATURDAY FOR ANZ050-
051.
&&
$$
NEAR TERM...FOSTER
SHORT TERM...HASTINGS
LONG TERM...FITZSIMMONS
AVIATION...FOSTER
MARINE...FOSTER/HASTINGS
AREA FORECAST DISCUSSION
NWS CARIBOU ME
350 PM EST FRI DEC 30 2011
.SYNOPSIS...
LOW PRESSURE OVER THE GREAT LAKES WILL WEAKEN TONIGHT WITH
REDEVELOPMENT OFF OF CAPE COD ON SATURDAY. THIS NEW LOW PRESSURE
WILL TRACK EASTWARD THROUGH THE GULF OF MAINE AND THEN SOUTH OF
NOVA SCOTIA BY SATURDAY EVENING. A HIGH PRESSURE RIDGE WILL BUILD
ACROSS THE REGION ON SUNDAY.
&&
.NEAR TERM /THROUGH SATURDAY/...
SHORTWAVE TROUGH FLATTENING UPPER RIDGE ACROSS THE STATE IS
PRODUCING AN AREA OF LIGHT SNOW SHOWERS ACROSS WESTERN MAINE THIS
AFTERNOON. HRRR MODEL INDICATES AS THIS SHORTWAVE TROUGH MOVES
ACROSS DOWNEAST LATE THIS AFTERNOON INTO THIS EVENING, A PERIOD OF
SNOW SHOWERS CAN BE EXPECTED WITH ANY ACCUMULATION LESS THAN AN
INCH.
MODELS IN GOOD AGREEMENT WITH LOW PRESSURE OVER THE GREAT LAKES
FILLING TONIGHT WITH REDEVELOPMENT JUST EAST OF CAPE COD BY SATURDAY
AFTERNOON. THE LOW PRESSURE WILL THEN TRACK EASTWARD AND MOVE SOUTH
OF NOVA SCOTIA BY SATURDAY NIGHT. AS HAS BEEN THE CASE THIS
WINTER, A LOW PRESSURE TRACKING SOUTH OF THE STATE WILL STILL
ALLOW FOR WARM AIR TO RIDE SOUTHWARD IN ADVANCE OF THE LOW
PRESSURE. THIS WARM AIR ALOFT WILL PRODUCE ANOTHER WINTRY MIX FOR
THE FORECAST AREA. CRITICAL THICKNESS NOW INDICATING MORE MIX THAN
SNOW SO HAVE REDUCE SNOW ACCUMULATION ACROSS CENTRAL AND NORTHERN
SECTIONS BY AROUND AN INCH AND INCREASE ICE ACCUMULATIONS BY A
TENTH OF AN INCH ACROSS CENTRAL PORTIONS. AT THIS TIME, EXPECT THE
AXIS OF HEAVIEST ICE TO OCCUR 30 MILES ON EITHER SIDE OF A LINE
FROM GREENVILLE TO HOULTON WHERE UP TO A QUARTER OF AN INCH MAY
ACCUMULATE. MODELS ALSO INDICATING TEMPERATURES WILL BE SLOW TO
RISE ACROSS DOWNEAST SO WILL EXTEND ADVISORY FROM 7 AM TO NOONTIME
SATURDAY.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
THINGS WILL BE WINDING DOWN SATURDAY NIGHT AS THE LOW MOVES OUT OF
THE GULF OF MAINE AND SOUTH OF NOVA SCOTIA. THERE WILL BE SOME
LINGERING FREEZING RAIN IN NORTHERN SECTIONS DURING THE EVENING BUT
COLDER AIR WRAPPING AROUND THE DEPARTING SYSTEM WILL CHANGE THE
PRECIPITATION TO ALL SNOW FROM NORTH TO SOUTH THROUGH THE NIGHT.
SNOWFALL AMOUNTS WILL BE LIGHT...GENERALLY A DUSTING TO AROUND HALF
AN INCH WITH ANOTHER TRACE OF ICE ACCUMULATION.
HIGH PRESSURE WILL BRIEFLY BUILD IN SUNDAY BEFORE ANOTHER LOW
PRESSURE SYSTEM MOVES BY TO OUR NORTH SUNDAY NIGHT AND MONDAY. THIS
WILL BRING ANOTHER ROUND OF SNOW AND RAIN TO THE REGION. THE
RAIN/SNOW LINE WILL BE SOUTH OF HOULTON AND MILLINOCKET WITH THE
IMMEDIATE COAST ALL RAIN BY MONDAY AFTERNOON. EXPECT TEMPERATURES TO
REACH INTO THE 30S DUE TO INCREASING SOUTH FLOW AHEAD OF THE
SYSTEM...BUT A STRONG COLD FRONT WILL PUSH THROUGH THE REGION DURING
THE DAY MONDAY USHERING IN MUCH COLDER AIR FOR THE WORK WEEK.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
COLDER AIR WILL FILTER INTO THE REGION FOR MONDAY NIGHT AND
TUESDAY ACCOMPANIED BY MAINLY CLOUDY SKIES ALONG WITH SCATTERED
SNOW SHOWERS AND FLURRIES DUE TO AN UPPER LEVEL TROUGH LINGERING
IN THE REGION. PRECIPITATION WILL BE CONFINED MAINLY TO NORTHERN
AREAS WHERE A FEW HEAVIER SNOW SHOWERS WILL BE POSSIBLE DUE TO
BANDS SETTING UP OFF THE ST. LAWRENCE. HIGH PRESSURE WILL BRIEFLY
MOVE IN FOR WEDNESDAY RESULTING IN MAINLY SUNNY SKIES AND DRY
CONDITIONS REGION WIDE. HOWEVER TEMPERATURES WILL STRUGGLE TO MAKE
IT OUT OF THE LOW TO MID TEENS NORTH WITH HIGHS DOWNEAST REACHING
THE LOW 20S. HIGH PRESSURE WILL SLIDE OFF TO THE EAST THURSDAY AS
THE NEXT UPPER LEVEL TROUGH APPROACHES THE EAST COAST RESULTING IN
INCREASING CLOUDS ALONG WITH THE SLIGHT CHANCE FOR A FEW FLURRIES
FOR THE END OF THE WEEK. AT THIS POINT ANY SURFACE CYCLOGENESIS
ASSOCIATED WITH THIS TROUGH LOOKS TO TAKE PLACE TOO FAR SOUTH AND
EAST TO AFFECT THE REGION WITH SIGNIFICANT PRECIPITATION.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
NEAR TERM: VFR CONDITIONS TONIGHT WILL LOWER TO IFR IN A WINTRY
MIX ON SATURDAY. THERE MAY BE A BRIEF PERIOD OF MVFR/IFR IN SNOW
AT KBGR AND KBHB BETWEEN 21Z-02Z AS AN AREA OF SNOW SHOWERS MOVES
ACROSS DOWNEAST.
SHORT TERM: IFR CONDITIONS IN SNOW AND RAIN THROUGH THE FIRST
PART OF SATURDAY NIGHT. PERIODS OF FREEZING RAIN WILL BE POSSIBLE
THROUGH 06Z SUNDAY. CONDITIONS WILL GRADUALLY IMPROVE AFTER
MIDNIGHT AND EXPECT ALL TERMINALS TO BE VFR BY 12Z SUNDAY. A
RETURN TO IFR COMES SUNDAY NIGHT AS SNOW SPREADS OVER THE REGION.
IFR IN SNOW AND RAIN SUNDAY NIGHT AND MONDAY.
BRIEF PERIODS OF MVFR/IFR CONDITIONS WILL BE POSSIBLE MONDAY
NIGHT AND TUESDAY FOR THE NORTHERN SITES DUE TO LINGERING SCATTERED SNOW
SHOWERS AND FLURRIES WITH VFR CONDITIONS PREDOMINATING FOR KBGR
AND KBHB. HIGH PRESSURE WILL BUILD IN WEDNESDAY WITH VFR
CONDITIONS EXPECTED FOR ALL SITES.
&&
.MARINE...
NEAR TERM: AS LOW PRESSURE MOVES THROUGH THE GULF OF MAINE, MINIMAL
SCA CONDITIONS POSSIBLE OVER OUR OUTER WATERS ON SATURDAY.
SHORT TERM: NO HEADLINES ANTICIPATED SATURDAY NIGHT AND SUNDAY AS
HIGH PRESSURE BRIEFLY BUILDS OVER THE WATERS. LOW PRESSURE WILL
MOVE BY TO THE NORTH SUNDAY NIGHT AND MONDAY SO EXPECT WINDS AND
SEAS TO INCREASE THROUGH THE PERIOD. A SMALL CRAFT ADVISORY WILL
LIKELY BE NEEDED WITH GALES A POSSIBILITY. WINDS AND SEAS WILL
CONTINUE TO BE AT SCA LEVELS FOR MONDAY NIGHT AND TUESDAY. SEAS
WILL DIMINISH WEDNESDAY BUT WINDS WILL CONTINUE TO REMAIN NEAR SCA
LEVELS BEFORE DIMINISHING FOR WEDNESDAY NIGHT AND THURSDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY FROM 1 AM TO 7 PM EST SATURDAY FOR
MEZ001>006-010.
WINTER WEATHER ADVISORY FROM 1 AM TO NOON EST SATURDAY FOR
MEZ011-015>017-031-032.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM TO 6 PM EST SATURDAY FOR ANZ050-
051.
&&
$$
NEAR TERM...FOSTER
SHORT TERM...HASTINGS
LONG TERM...FITZSIMMONS
AVIATION...FOSTER
MARINE...FOSTER/HASTINGS
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
443 AM EST SUN JAN 1 2012
.SYNOPSIS...
AN INTENSIFYING LOW PRESSURE SYSTEM WILL PUSH INTO THE GREAT LAKES
TODAY, BRINGING A STRONG COLD FRONT AND GUSTY WINDS ACROSS THE
UPPER OHIO VALLEY. THE COLDEST AIR OF THE SEASON WILL PUSH IN
BEHIND THE FRONT WITH SNOW SHOWERS EXPECTED TONIGHT INTO TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE LATEST RUC MID-LEVEL ANALYSIS INDICATES A 500MB TROUGH AXIS
EXTENDING FROM THE UPPER MIDWEST INTO THE MISSOURI VALLEY. AHEAD OF
THIS FEATURE, A WEAK RIDGE IS SHIFTING EAST OF THE UPPER OHIO
VALLEY. A DEEP LAYER OF DRY AIR IS IN PLACE, WITH STRATOCUMULUS
ASSOCIATED WITH A 1000-900MB LAYER MOISTURE PUSHING NORTHEAST OF
THE AREA. AT THE SURFACE, AS 1000MB LOW IS CENTERED ACROSS
NORTHERN ILLINOIS. WITH A 1021MB SURFACE HIGH CENTERED OFF THE
CAROLINA COAST, THE PRESSURE GRADIENT IS TIGHTENING ACROSS THE
OHIO VALLEY. IN ADDITION, A COLD FRONT EXTENDS SOUTHWARD OF THE
LOW ACROSS THE MISSOURI VALELY.
TODAY...THE TROUGH WILL DIG INTO THE OHIO VALLEY AND THE SURFACE LOW
WILL MOVE NORTHEASTWARD ACROSS THE LP OF MICHIGAN, SWINGING THE
FRONT ACROSS THE UPPER OHIO VALLEY AND TIGHTENING THE PRESSURE
GRADIENT ACROSS THE AREA. THE FRONT WILL MOSTLY BE DRY WITH ITS
PASSAGE, ALTHOUGH WITH A TIGHT THERMAL GRADIENT AND HIRES MODELS
INDICATING SUFFICIENT FORCING, CHANCE POPS ARE FORECAST WITH ITS
PASSAGE.
THE MAIN WEATHER IMPACT TODAY WILL BE GUSTY WINDS WITH THE
FRONTAL PASSAGE AND DIURNAL MIXING IN CAA IN THE WAKE OF THE FRONT.
NAM/WRF-NMM SOLUTIONS SUPPORT SUSTAINED WINDS OF 20-25KTS WITH GUSTS
OF 35-40KTS AND THE ONGOING WIND ADVISORY. EXPECT THE GUSTS TO PICK
UP LATE THIS MORNING ACROSS EASTERN OHIO AND ACROSS THE REST OF THE
AREA BY EARLY AFTERNOON. FOR TEMPS, HIGHS WILL BE REACHED MOSTLY BY
18Z, AS CAA KICKS IN. TEMPS ARE A MAV/MET BLEND, RANGING FROM NEAR
50 ACROSS NORTHERN WV AND SOUTHWEST PA TO THE MID 40S FOR AREAS
NORTHWEST OF PITTSBURGH AND ACROSS THE EASTERN RIDGES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
THERE IS NAM/GFS AGREEMENT THAT THE MID-LEVEL TROUGH WILL DEEPEN AND
BECOME MORE AMPLIFIED AS IT MOVES ACROSS THE OHIO VALLEY TO THE EAST
COAST SUNDAY NIGHT THROUGH TUESDAY.
SUNDAY NIGHT...THE MID-LEVEL TROUGH WILL INSTIGATE SHOWERS ACROSS
THE AREA WITH LOW-LEVEL THICKNESSES QUICKLY DECREASING AND TURNING
PRECIPITATION OVER TO ALL SNOW SHOWERS. THE SURFACE LOW WILL PUSH
NORTHEAST INTO ONTARIO WITH GUSTS WEAKENING WITH THE DECREASE OF
MIXING WITH THE LOSS OF DIURNAL HEATING. WITH A TIGHTENED PRESSURE
GRADIENT, WINDS WILL STILL GUST AT 20-30KTS OVERNIGHT. FOR LOWS,
ONGOING CAA WILL BE IN PLACE, ALTHOUGH CLOUD COVERAGE WILL SERVE TO
COUNTER COLDER AIR ALOFT. LOWS WILL RANGE FROM THE LOWER 20S ACROSS
THE EASTERN RIDGES TO THE MID 20S ELSEWHERE. A LOW-LEVEL FLOW OUT OF
290 DEGREES WILL LIMIT LAKE EFFECT INITIALLY WITH AN INCH
FORECAST OVERNIGHT FOR THE I-80 CORRIDOR.
MONDAY AND MONDAY NIGHT...850MB FLOW WILL SHIFT TO
WEST-NORTHWESTERLY BY 18Z MONDAY AND TAP INTO A HURON FETCH AS IT
SHIFTS TO NORTHWESTERLY BY 00Z TUESDAY. THIS WILL ALLOW FOR LAKE
EFFECT SNOW SHOWERS AND UPSLOPING EVENT TO BEGIN IN EARNEST. WITH
850MB TEMPS NEAR -13C AND A WARM LAKE ERIE WITH TEMPS NEAR 4C, THE
TEMP DIFFERENTIAL WILL BE SUFFICIENT ALONG WITH A DEEP ISOTHERMAL
PROFILE. THUS, ACCUMULATIONS ARE FORECAST OF 4 TO 8 INCHES WITH BANDING OF
SNOWFALL ACROSS THE LAKE EFFECT ZONES AND UPSLOPING FOR THE
RIDGES. EXPECT 2 TO 4 INCHES SOUTH OF I-80 AND NORTH OF PITTSBURGH
WITH 1 TO 3 INCHES FOR AREAS SOUTH AND WEST OF PITTSBURGH.
TUESDAY...ONGOING LAKE EFFECT SNOW EVENT WILL BEGIN TO WIND DOWN
AS A SURFACE HIGH AND LOW-LEVEL RIDGING BUILD INTO THE UPPER OHIO
VALLEY. A LOWERING SUBSIDENCE INVERSION WILL MOSTLY DIMINISH THE
MORE PERSISTENT ACCUMULATING SNOW SHOWERS FOR THE RIDGES AND I-80
CORRIDOR BY THE AFTERNOON HOURS WITH SNOW SHOWERS COMING TO AN END
ELSEWHERE. THE CORE OF THE COLDEST AIR WILL HAVE BUILT IN, WITH
HIGHS STRUGGLING TO REACH THE LOWER 20S ACROSS MUCH OF THE AREA.
GUSTY WINDS OF 20-25KTS ALONG WILL YIELD WIND CHILLS IN THE
SINGLE DIGITS ACROSS THE LOWLANDS AND BELOW ZERO ACROSS THE HIGHER
ELEVATIONS MONDAY THROUGH TUESDAY.
BY THE END OF THIS EVENT, STORM TOTAL ACCUMULATIONS OF 8 TO 12
INCHES WILL BE POSSIBLE FOR THE RIDGES WITH THE I-80 CORRIDOR
GETTING 6 TO 10 INCHES. THUS, LAKE EFFECT SNOW AND WINTER STORM
WATCHES HAVE BEEN UPGRADED TO WARNINGS. THE NEXT TIER OF COUNTIES
SOUTH OF I-80 AND NORTH OF PITTSBURGH MAY NEED ADVISORIES, HOWEVER
AT THIS TIME, CONFIDENCE IN ACCUMULATIONS REACHING 12-HOUR/24-HOUR
CRITERIA IS TOO LOW THERE. THUS, THE WINTER STORM WATCH FOR
JEFFERSON AND CLARION COUNTIES REMAINS IN EFFECT.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THERE IS REASONABLE NAEFS/ECMWF MEAN AGREEMENT THAT HIGH PRESSURE WILL
CROSS THE AREA ON TUESDAY NIGHT, BRINGING A DRY FORECAST AND A
RESPITE FROM SNOW SHOWERS. WITH THE COLDEST AIR OF THE SEASON SET IN
AND RADIATIONAL COOLING POSSIBLE, LOWS TUESDAY NIGHT WILL RANGE FROM
THE SINGLE DIGITS ACROSS THE EASTERN RIDGES TO THE LOWER TEENS
ACROSS THE REMAINDER OF THE AREA.
GFSE/ECMWF BLEND WAS USED FOR THE REMAINDER OF THE PERIOD. A ZONAL
MID-LEVEL FLOW WILL BE IN PLACE FOR WEDNESDAY WITH THE SLIGHT CHANCE
OF SNOW SHOWERS. A SHORT WAVE WILL CROSS THE AREA ON WEDNESDAY NIGHT
INTO THURSDAY BRINGING A BETTER CHANCE OF SNOW SHOWERS. WEAK SURFACE
RIDGING IS PROGGED TO DRY THE FORECAST OUT FOR THURSDAY NIGHT INTO
FRIDAY. A FRONT IS THEN PROGGED TO CROSS THE UPPER OHIO VALLEY FOR
THE EARLY WEEKEND. TEMPS WILL BE PROGRESSIVELY WARMER MID-WEEK INTO
THE WEEKEND, AT AROUND 5 DEGREES BELOW NORMAL ON WEDNESDAY AND
WARMING EACH DAY TO 10 DEGREES ABOVE NORMAL BY FRIDAY AND SATURDAY.
&&
.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
CLEARING LINE WORKING NORTHEAST ACROSS REGION AND SHOULD PASS KFKL
AND KDUJ BY 09-10Z. A STRONG COLD FRONT APPROACHES WILL APPROACH
TODAY AND THE PRESSURE GRADIENT WILL TIGHTEN SIGNIFICANTLY AHEAD OF
THE FRONT WITH WINDS SHIFTING FROM SOUTH TO SOUTHWEST AND GUSTS OVER
30KTS. AS UPPER LEVEL TROUGH ADVANCES EAST FROM THE GREAT LAKES THIS
AFTERNOON EXPECT GENERAL MVFR CIGS WITH A FEW LIGHT SHOWERS AND
WINDS BECOMING WEST AND GUSTING 30-35KTS ESPECIALLY NORTHERN
TERMINALS. STRONG COLD ADVECTION WILL BRING LIGHT SNOW SHOWERS LATE
AFTERNOON OR EVENING AND CONTINUE INTO THE OVERNIGHT WITH WEST WINDS
REMAINING GUSTY.
OUTLOOK...MONDAY THROUGH THURSDAY
GUSTY WINDS WILL REMAIN MONDAY AND TURN NORTHWEST WITH IFR
RESTRICTIONS POSSIBLE WITH SNOW SHOWERS MONDAY THROUGH TUESDAY
NIGHT. VFR CONDITIONS WILL RETURN WEDNESDAY BEFORE THE NEXT
DISTURBANCE BRINGS THE CHANCE OF SNOW SHOWERS WITH RESTRICTIONS ON
THURSDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WIND ADVISORY FROM 11 AM THIS MORNING TO 10 PM EST THIS
EVENING FOR MDZ001.
WINTER STORM WARNING FROM 1 AM MONDAY TO 4 PM EST TUESDAY FOR
MDZ001.
OH...WIND ADVISORY FROM 8 AM THIS MORNING TO 7 PM EST THIS EVENING
FOR OHZ039>041-048>050-057>059-068-069.
PA...WIND ADVISORY FROM 11 AM THIS MORNING TO 10 PM EST THIS
EVENING FOR PAZ007>009-013>016-020>023-029-031-073>076.
WINTER STORM WARNING FROM 1 AM MONDAY TO 4 PM EST TUESDAY FOR
PAZ074-076.
LAKE EFFECT SNOW WARNING FROM 1 AM MONDAY TO 4 PM EST TUESDAY
FOR PAZ007>009.
WINTER STORM WATCH FROM LATE TONIGHT THROUGH TUESDAY EVENING
FOR PAZ015-016.
WV...WIND ADVISORY FROM 8 AM THIS MORNING TO 7 PM EST THIS EVENING
FOR WVZ001>004-012.
WIND ADVISORY FROM 11 AM THIS MORNING TO 10 PM EST THIS
EVENING FOR WVZ021>023-041.
WINTER STORM WARNING FROM 1 AM MONDAY TO 4 PM EST TUESDAY FOR
WVZ023-041.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
127 AM EST SUN JAN 1 2012
.SYNOPSIS...
AN INTENSIFYING LOW PRESSURE SYSTEM WILL PUSH INTO THE GREAT LAKES
TODAY, BRINGING A STRONG COLD FRONT AND GUSTY WINDS ACROSS THE
UPPER OHIO VALLEY. THE COLDEST AIR OF THE SEASON WILL PUSH IN
BEHIND THE FRONT WITH SNOW SHOWERS EXPECTED TONIGHT INTO TUESDAY.
&&
.NEAR TERM /THROUGH TODAY/...
THE LATEST RUC MID-LEVEL ANALYSIS INDICATES A 500MB TROUGH AXIS
EXTENDING FROM THE UPPER MIDWEST INTO THE SOUTHERN PLAINS. AHEAD OF
THIS FEATURE, A WEAK RIDGE IS MOVING ACROSS THE UPPER OHIO VALLEY. A
DEEP LAYER OF DRY AIR ALOFT IS IN PLACE, WITH STRATOCUMULUS ASSOCIATED
WITH 1000-900MB LAYER MOISTURE QUICKLY LIFTING NORTHWARD OF THE AREA.
AT THE SURFACE, A 1000MB LOW IS CENTERED ACROSS IOWA. WITH A
1021MB SURFACE HIGH CENTERED IN THE CAROLINAS, THE PRESSURE
GRADIENT ACROSS THE OHIO VALLEY IS TIGHTENING BETWEEN THESE TWO
FEATURES. IN ADDITION, A COLD FRONT EXTENDS SOUTHWARD OF THE LOW
AND INTO THE SOUTHERN PLAINS.
TODAY...THE TROUGH WILL DIG INTO THE OHIO VALLEY AND THE SURFACE LOW
WILL SLIDE NORTHEAST ACROSS THE LP OF MICHIGAN, BRINGING THE FRONT
ACROSS THE UPPER OHIO VALLEY AND TIGHTENING THE PRESSURE GRADIENT
ACROSS THE AREA. THE FRONT WILL BE MOSTLY DRY BUT MAY PRODUCE A
FEW SHOWERS WITH ITS PASSAGE AS INDICATED BY THE HIRES MODELS.
WITH THIS IN CONSIDERATION, CHANCE POPS ARE FORECAST
THE SIGNIFICANT WEATHER IMPACT TODAY WILL BE GUSTY WINDS WITH THE
FRONTAL PASSAGE AND DIURNAL MIXING IN CAA IN THE WAKE OF THE FRONT.
NAM/WRF-NMM SOLUTIONS SUPPORT SUSTAINED WINDS OF 20-25KTS WITH GUSTS
OF 35-40KTS AND THE ONGOING WIND ADVISORY. EXPECT THE GUSTS TO PICK
UP LATE THIS MORNING ACROSS EASTERN OHIO AND ACROSS THE REST OF THE
AREA BY EARLY AFTERNOON. FOR TEMPS, HIGHS WILL BE REACHED MOSTLY BY
18Z, AS CAA KICKS IN. TEMPS ARE A MAV/MET BLEND, RANGING FROM NEAR
50 ACROSS NORTHERN WV AND SOUTHWEST PA TO THE MID 40S FOR AREAS
NORTHWEST OF PITTSBURGH.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY/...
ALTHOUGH GUSTS WILL BEGIN TO DECREASE SUNDAY EVENING...SUSTAINED
WINDS WILL REMAIN STRONG OVERNIGHT...AND EXPECT THAT SOME LAKE
EFFECT/UPSLOPE SNOW WILL BEGIN TO FALL. WITH WINDS REMAINING
WEST-SOUTHWESTERLY SUNDAY NIGHT INTO MONDAY...THIS SHOULD DELAY
HEAVIER SNOW FROM DEVELOPING ACROSS THE I-80 CORRIDOR. BY MONDAY
AFTERNOON...WESTERLY WINDS WILL ALLOW SNOW TO INCREASE IN INTENSITY
ACROSS THE NORTHERN COUNTIES. THERE SHOULD BE ENOUGH MOISTURE TO
ALLOW ALL LOCATIONS TO SEE SOME SNOWFALL ACCUMULATIONS. 12Z NAM
INDICATES THAT FETCH COULD LINE UP FOR FLOW FROM LAKE HURON ACROSS
LAKE ERIE AND INTO THE RIDGES LATE MONDAY INTO EARLY TUESDAY...WHICH
WOULD ONLY INTENSIFY SNOWFALL. HAVE DECIDED TO GO WITH LAKE EFFECT
AND WINTER STORM WATCHES FOR COUNTIES NEAR INTERSTATE 80 AND ALONG
THE RIDGES FOR SUNDAY NIGHT INTO TUESDAY. SNOWFALL AMOUNTS MAY NOT
HIT TRUE 24 HOUR CRITERIA...BUT FEEL WATCH IS JUSTIFIED CONSIDERING
EXTENDED PERIOD OF SNOWFALL. INVERSION LEVELS AND MOISTURE AMOUNTS
WILL BEGIN TO DECREASE TUESDAY AFTERNOON...ALLOWING FOR A REDUCTION
IN SNOW SHOWERS. OTHER MAIN STORY WILL BE THE COLDEST TEMPERATURES
SO FAR THIS WINTER SEASON. HIGHS WILL NOT REACH 30 DEGREES ON
MONDAY...WITH SOME LOCATIONS NOT REACHING THE 20S ON TUESDAY. LOWS
MONDAY NIGHT WILL DROP INTO THE TEENS AND POSSIBLY SINGLE DIGITS.
WITH SUSTAINED WINDS REMAINING 10-20 MPH...THIS WILL BRING SOME OF
THE COLDEST WIND CHILLS SO FAR...BETWEEN 0 AND 5 ABOVE.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THERE IS REASONABLE NAEFS/ECMWF MEAN AGREEMENT THAT HIGH PRESSURE WILL
CROSS THE AREA ON TUESDAY NIGHT, BRINGING A DRY FORECAST AND A
RESPITE FROM SNOW SHOWERS. WITH THE COLDEST AIR OF THE SEASON SET IN
AND RADIATIONAL COOLING POSSIBLE, LOWS TUESDAY NIGHT WILL RANGE FROM
THE SINGLE DIGITS ACROSS THE EASTERN RIDGES TO THE LOWER TEENS
ACROSS THE REMAINDER OF THE AREA.
GFSE/ECMWF BLEND WAS USED FOR THE REMAINDER OF THE PERIOD. A ZONAL
MID-LEVEL FLOW WILL BE IN PLACE FOR WEDNESDAY WITH THE SLIGHT CHANCE
OF SNOW SHOWERS. A SHORT WAVE WILL CROSS THE AREA ON WEDNESDAY NIGHT
INTO THURSDAY BRINGING A BETTER CHANCE OF SNOW SHOWERS. WEAK SURFACE
RIDGING IS PROGGED TO DRY THE FORECAST OUT FOR THURSDAY NIGHT INTO
FRIDAY. A FRONT IS THEN PROGGED TO CROSS THE UPPER OHIO VALLEY FOR
THE EARLY WEEKEND. TEMPS WILL BE PROGRESSIVELY WARMER MID-WEEK INTO
THE WEEKEND, AT AROUND 5 DEGREES BELOW NORMAL ON WEDNESDAY AND
WARMING EACH DAY TO 10 DEGREES ABOVE NORMAL BY FRIDAY AND SATURDAY.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
GENERAL MVFR CIGS NORTH AND EAST OF A KMGW TO KHLG LINE WITH
CLEARING LINE ACROSS EASTERN OHIO AND NORTHERN WEST VIRGINIA AT 06Z.
THIS LINE WILL PROGRESS NORTH AND STALL TODAY AS A STRONG COLD
FRONT APPROACHES. THE PRESSURE GRADIENT WILL TIGHTEN SIGNIFICANTLY
AHEAD OF THE FRONT WITH WINDS SHIFTING FROM SOUTH TO SOUTHWEST AND
GUSTS OVER 30KTS. AS UPPER LEVEL TROUGH ADVANCES EAST FROM THE GREAT
LAKES THIS AFTERNOON EXPECT GENERAL MVFR CIGS WITH A FEW LIGHT
SHOWERS AND WINDS BECOMING WEST AND GUSTING 30-35KTS ESPECIALLY
NORTHERN TERMINALS. STRONG COLD ADVECTION WILL BRING LIGHT SNOW
SHOWERS LATE AFTERNOON OR EVENING AND CONTINUE INTO THE OVERNIGHT
WITH WEST WINDS REMAINING GUSTY.
OUTLOOK...MONDAY THROUGH THURSDAY
GUSTY WINDS WILL REMAIN MONDAY AND TURN NORTHWEST WITH IFR
RESTRICTIONS POSSIBLE WITH SNOW SHOWERS MONDAY THROUGH TUESDAY
NIGHT. VFR CONDITIONS WILL RETURN WEDNESDAY BEFORE THE NEXT
DISTURBANCE BRINGS THE CHANCE OF SNOW SHOWERS WITH RESTRICTIONS ON
THURSDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WIND ADVISORY FROM 11 AM THIS MORNING TO 10 PM EST THIS
EVENING FOR MDZ001.
WINTER STORM WATCH FROM LATE TONIGHT THROUGH TUESDAY EVENING
FOR MDZ001.
OH...WIND ADVISORY FROM 8 AM THIS MORNING TO 7 PM EST THIS EVENING
FOR OHZ039>041-048>050-057>059-068-069.
PA...WIND ADVISORY FROM 11 AM THIS MORNING TO 10 PM EST THIS
EVENING FOR PAZ007>009-013>016-020>023-029-031-073>076.
WINTER STORM WATCH FROM LATE TONIGHT THROUGH TUESDAY EVENING
FOR PAZ015-016-074-076.
LAKE EFFECT SNOW WATCH FROM LATE TONIGHT THROUGH TUESDAY
EVENING FOR PAZ007>009.
WV...WIND ADVISORY FROM 8 AM THIS MORNING TO 7 PM EST THIS EVENING
FOR WVZ001>004-012.
WIND ADVISORY FROM 11 AM THIS MORNING TO 10 PM EST THIS
EVENING FOR WVZ021>023-041.
WINTER STORM WATCH FROM LATE TONIGHT THROUGH TUESDAY EVENING
FOR WVZ023-041.
&&
$$
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
958 AM EST FRI DEC 30 2011
.SYNOPSIS...
LOW PRESSURE WILL STRENGTHEN OVER THE CENTRAL MIDWEST REGION THROUGH
TONIGHT...BEFORE MOVING INTO NEW ENGLAND ON SATURDAY. A COLD
FRONT WILL CROSS THE REGION SATURDAY MORNING. HIGH PRESSURE WILL
RETURN TO THE REGION SATURDAY NIGHT BEFORE MOVING OFF THE COAST
SUNDAY. A STRONG COLD FRONT WILL ARRIVE LATE SUNDAY NIGHT AND WILL
USHER IN BLUSTERY ARCTIC AIR MONDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
LATEST WV SAT LOOP SHOWS AN UPPER LOW SPINNING OVER ERN IA THIS
MRNG. A POTENT ULVL JET STREAK DIGGING ON THE WRN SIDE OF THE LOW
WILL LEAD TO AMPLIFICATION OF THE TROUGH AS IT MOVES TOWARD THE
OH VLY BY LATE TDA. SYNOPTIC-SCALE FLOW AHEAD OF THE LOW WILL
BACK AND STRENGTHEN OVER THE ERN CONUS. DOWNSTREAM IMPACTS IN THE
MID-ATLANTIC FROM THE DEVELOPING S-SW FLOW INCLUDE ADVECTION OF
MILDER AIR AND AN INCREASE IN MID-HI CLOUDS THRUOUT THE DAY. CLOUD
COVER WILL VARY ACROSS THE CWA...BUT ON AVG WILL RANGE FROM PARTLY
SUNNY ACROSS SRN MD TO CLOUDY ALONG THE ALLEGHENY FRONT. DESPITE
LIMITED DAYTIME HEATING FROM THE CLOUD COVER...MAX TEMPS WILL
STILL REACH THE LOW/MID 50S AS A WARM AIRMASS IS IN PLACE /12Z IAD
RAOB SHOWS 9C LAYER AT THE TOP OF THE NOCTURNAL INVERSION/.
LATEST RADAR LOOP OVERLAID WITH RUC ANALYSIS SHOWS LGT RETURNS
CROSSING THE APPALACHIANS IN ASSOCIATION WITH A BAND OF LOW-MID
LVL ISENTROPIC LIFT/CONVERGENCE WELL AHEAD OF THE LOW AND IN THE
LEFT-EXIT REGION OF AN UPPER JET STREAK. HAVE ADDED ISO LGT RAIN
SHOWERS AND SPRINKLES INTO THE FCST FOR THE POTOMAC HIGHLANDS
FROM LATE THIS MRNG THRU THE ERY AFTN.
TONIGHT...UPR TROUGH ASSOCIATED WITH THE MIDWEST LOW CROSSES THE CWA
AFTER MIDNIGHT. DPVA ASSOCIATED WITH THIS TROUGH WILL PRODUCE LOW/MID-
LEVEL CLOUDS. THEREFORE...LOW CHANCES FOR LIGHT RAIN SHOWERS WERE
EXPANDED ACROSS THE CWA. HOWEVER...LIMITED MOISTURE AND
DOWNSLOPING LOW-LEVEL FLOW WILL KEEP ANY DEVELOPMENT AS
LIGHT/SPRINKLES. LIKELY POPS FOR THE FAR WRN SLOPES OF THE
HIGHLANDS. MILD NIGHT FOR LATE DECEMBER...WITH SLY FLOW AND
CLOUDS...SO PTYPE TNGT WILL BE RAIN. MIN TEMPS MID/UPPER 30S WEST
OF THE BLUE RIDGE...UPR 30S TO LOW 40S EAST /IN URBAN AND NEAR-
SHORE LOCALES/...ABOUT 10 DEGREES ABOVE NORMAL.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
UPR RDG WILL BE FOUND OVER MID-ATLC RGN ON SAT. SHRTWV TROF OVER
CNTRL PLNS AND A SECOND SHRTWV TROF OVER S-CNTRL CANADA WILL PHASE
IN GRTLKS RGN SAT NGT...LEADING TO DP CLOSED LOW OVER MI.
LOW-LVL JET WILL STRENGTHEN OVER MID-ATLC RGN ON SUN IN RESPONSE
TO STRENGTHENING LOW IN GRTLKS. WARM AIR ADVCTN WILL ENSURE THAT
ANY PCPN ON SUN FALLS AS RAIN. BUT WINDS WILL BCM WLY AND QUITE
GUSTY AS SFC TROF CROSSES THE RGN. BY LATE AFTN...COLDER AIR MAY
BE BANKED AGAINST THE APLCNS.
MAXIMA THIS WKEND WILL CONT TO BE QUITE MILD IN THE MID-UPR 50S.
MINIMA SAT NGT WILL BE NR NRML...IN THE LOW-MID 30S.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
CLOSED UPR LOW ON SUN WILL BE LOCATED JUST N OF GRTLKS RGN AND
WILL SPAN MUCH OF THE ERN CONUS. H5 RDG WILL AMPLIFY OVER WRN
CONUS. A SHRTWV TROF WILL MOVE SWD INTO THE CONUS AHD OF THIS RDG
AND WILL DISLODGE ARCTIC AMS. THIS COLD AMS WILL MOVE INTO THE
GRTLKS RGN ON MON AND INTO NEW ENGLAND BY TUE.
MODEST MSTR AHEAD OF THIS APRCHG SHRTWV TROF AND COLD ADVCTN ALOFT
ASSOCIATED WITH THE WAVE WILL LEAD TO SGFNT INSTBY ALONG WRN
SLOPES OF POTOMAC HIGHLANDS FOR A PROLONGED PD MON-TUE MRNG. WITH
MAXIMA XPCD TO RMN BLW FRZG IN THESE ZONES...SGFNT SNOW ACCUMS
XPCD...LKLY WARRANTING WINTER HEADLINES AS THE TIME NRS. WINDS
ALSO WILL BE OF CONCERN DURG THIS EVENT...LEADING TO HAZARDOUS
WIND CHILLS AND POOR VSBYS. ANY PCPN THAT CROSSES THE MTNS WILL BE
VERY LGT OWING TO DOWNSLOPING FLOW.
STRONG COLD ADVCTN WILL OCCUR ON TUE AS ARCTIC AMS OVERTAKES THE
NERN CONUS. H9 TEMPS AS LOW AS 10 TO 15 BLW ZERO COULD LEAD TO
MAXIMA IN THE MID-UPR 20S AND MINIMA IN TEENS...WITH SINGLE DIGIT
TEMPS XPCD AT HIGHER ELEVATIONS. ANY ONGOING SNOW SHWRS ON WRN
SLOPES WILL COME TO AN END AS SFC HIPRES BUILDS INTO THE RGN. SFC
RDG WILL BE LOCATED IN MID- ATLC RGN ON WED.
MAXIMA WERE UNDERCUT BY SVRL DEG F ON TUE. MINIMA TUE NGT IN
PARTICULAR WILL BE VERY COLD AS SFC HIPRES BUILDS.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
VFR WITH SLY FLOW 5-10 KT TODAY. MID AND HIGH CLOUDS DURING THE
DAY WILL GRADUALLY LOWER TO 3-6 KFT OVNGT AS A COLD FRONT
APPROACHES FROM THE WEST. SHRA POSSIBLE DURING THIS TIME AS THE
FRONT MOVES THRU. ANY SHOWER ACTIVITY WILL BE ISO AND LGT.
VFR CONDS WILL CONT THRU NEXT WK. BUT SGFNT WIND WILL BE OF
CONCERN TO AVIATION INTERESTS AS SFC TROF AND CDFNT ARRIVE EARLY
NEXT WK. SGFNT TURBULENCE CAN BE ANTICIPATED.
&&
.MARINE...
SLY/SSWLY FLOW INCREASES TODAY AHEAD OF A COLD FRONT THAT MOVES
THRU EARLY SATURDAY. SMALL CRAFT ADVISORY GOES INTO EFFECT AT 2PM
SOUTH OF DRUM PT...THEN UP THE MAIN CHANNEL OF THE BAY /SOUTH OF
POOLES ISLAND/ AND LOWER TIDAL POTOMAC RIVER FOR TONIGHT. MAX
GUSTS EXPECTED AROUND 20 KT.
SMALL CRAFT ADZY WAS EXPANDED TO ALL ZONES ON SAT AS CDFNT CROSSES
THE RGN. WINDS WILL SUBSIDE SAT NGT AS HIPRES BUILDS.
SFC TROF AND SUBSEQUENT CDFNT ASSOCIATED WITH ARCTIC AMS WILL
IMPACT THE WATERS EARLY NEXT WK. SMALL CRAFT ADZY WILL BE NEEDED.
GALE WRNG MAY BE NEEDED DURG THIS TIME.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM TO 6 PM EST SATURDAY FOR ANZ530-
535-536-538-539-542.
SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 6 PM EST
SATURDAY FOR ANZ534-543.
SMALL CRAFT ADVISORY FROM 5 PM THIS AFTERNOON TO 6 PM EST
SATURDAY FOR ANZ531>533-537-540-541.
&&
$$
UPDATE...KLEIN
PREV DISC...JACKSON/KRAMAR
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1254 PM EST FRI DEC 30 2011
UPDATED AVIATION DISCUSSION FOR 18Z TAFS
.UPDATE...
NOT A WHOLE LOT OF WEATHER OF SIGNIFICANCE TODAY BUT STILL A TRICKY
UPDATE. CURRENTLY...LOW PRESSURE SYSTEM IS BRINGING MIXED PRECIPITATION
TO SOUTHERN PORTIONS OF WISCONSIN...BUT THIS SYSTEM WILL REMAIN TO
THE SOUTH OF THE CWA THROUGH THE DAY. LOW PRESSURE TROUGH EXTENDS
NORTH OF THE SFC LOW ACROSS CNTRL UPR MI. CONDITIONS ARE MAINLY DRY
THOUGH WITH EVEN SOME SUNSHINE THROUGH HIGHER CLOUDS OVR CNTRL CWA
THIS MORNING. LOW-LEVELS REMAIN VERY SATURATED OVR EASTERN CWA AND
ALONG WITH LOW CLOUDS AND FOG THERE IS LIKELY SOME FZDZ/MIST OCCURRING
AS WELL. LK EFFECT IS RESTRICTED TO CNTRL AND EASTERN LK SUPERIOR
BASED ON VISIBLE SATELLITE.
AS THE LOW TO THE SOUTH HEADS INTO LOWER MICHIGAN LATER TODAY...
EXPECT WINDS OVR MOST OF LK SUPERIOR INTO UPR MI TO BECOME MORE
NORTHERLY. THIS SHOULD ALLOW FOR SOME LK EFFECT SNOW SHOWERS TO WORK
ONSHORE OVR KEWEENAW AND ALSO IN NCNTRL UPR MI. TEMPS AT INVERSION
TOP AROUND 900MB ONLY STRUGGLE TO REACH -7C...SO FZDZ COULD OCCUR.
SEEMS LIKE THERE IS ENOUGH DRY AIR IN BLYR BASED ON SFC DEWPNT
DEPRESSIONS UP TO 4F AT KCMX/KP59 TO LIMIT THAT RISK THOUGH...AND
PROBABLY WOULD JUST SEE FLURRIES IF SNOW SHOWERS CAN NOT REALLY ADVECT
ONSHORE. TEMPS TODAY SHOULD REACH INTO THE 27-32 RANGE...COLDEST IN
THE CNTRL CWA WHERE THE CLEARING LATE LAST NIGHT ALLOWED LOWS TO DIP
TOWARD 10 ABOVE.
ALL LIGHT PRECIPITATION WILL CEASE OVERNIGHT TONIGHT AS WINDS BECOME
MORE SOUTHERLY IN ADVANCE OF STRONGER LOW PRESSURE SYSTEM MOVING
INTO THE PLAINS.
&&
.SYNOPSIS...
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW WNW FLOW ALF OVER
THE GRT LKS BTWN LO AMPLITUDE RDGING OVER THE W AND A TROF N JUST
OFF THE E COAST. SHRTWV RESPONSIBLE FOR SN ON THU IS PUSHING EWD
TOWARD SE ONTARIO...BUT WEAK SFC-H85 TROF REMAINS OVER ERN UPR MI.
BUT WITH DNVA/DEEP LYR QVECTOR DVGC/SUBSIDENCE/DRYING ALF IN THE
WAKE OF THE SHRTWV...THE PCPN OVER THE CWA HAS PRETTY MUCH ENDED.
THE MQT 88D DOES SHOW HIER RADAR RETURNS OVER ECNTRL LK SUP NEAR
WEAK SFC LO CENTER. 00Z INL RAOB SHOWS SHARP INVRN BASE NEAR H875
WITH TEMP JUST BLO THE INVRN DOWN TO -14C...LO ENUF TO SUPPORT LES.
ALTHOUGH THE 00Z INL RAOB INDICATES MODEST DRYING IN THE SUB INVRN
LYR...SKIES ARE GENERALLY CLDY AT MOST LOCATIONS FM THE MN ARROWHEAD
SEWD THRU UPR MI...BUT SOME BREAKS IN THE CLDS ARE EVIDENT. FARTHER
TO THE W/SW IN MN/WI...SKIES ARE MOCLR CLOSER TO WEAK SFC RDG AXIS
ASSOCIATED WITH INCOMING SHRTWV RDG MOVING E THRU MN. ANOTHER PAIR
OF SHRTWVS ARE NOTED IN THE NRN/CNTRL PLAINS...BUT THESE APPEAR TO
BE DIGGING TO THE SE. MUCH FARTHER TO THE W...A STRONG SHRTWV IS
APRCHG THE PAC NW. UPSTREAM HI TEMPS YDAY SUG MAX TEMPS WL GENERALLY
BE ARND 30.
&&
.DISCUSSION...
MAIN FCST CONCERNS THIS PACKAGE SHIFT TO POTENTIAL SN EVENT ON NEW
YEARS DAY/MON RELATED TO SHRTWV NOW APRCHG THE PAC NW.
TDAY...LOOKS LIKE A RELATIVELY QUIET DAY ON TAP WITH WEAK HGT
RISES/DRYING ALF IN THE WAKE OF DEPARTING SHRTWV. SHRTWV COMPLEX IN
THE PLAINS IS FCST TO CONSOLIDATE IN THE LOWER GRT LKS...WITH
ACCOMPANYING DEEP LYR QVECTOR CNVGC/PCPN PASSING S OF UPR MI. FCST
SDNGS SHOW INVRN BASE SINKING TO H9-925 OVER THE CWA IN THE AFTN...
WITH INVRN BASE TEMPS NO LOWER THAN ABOUT -8C. CONSIDERING
THE WEAK SFC WINDS FCST THAT WOULD NOT SUPPORT ORGANIZATION OF LES
BANDS...THE MARGINAL NATURE OF THE CHILL/DGZ ABV THE SUB INVRN
LYR...AND SOME LLVL DRYING...SUSPECT THERE WL BE LTL IN THE WAKE OF
LES. BUT SINCE THE 00Z INL RAOB DID SHOW -14C AIR AT THE H875 INVRN
BASE AND THE GFS/NAM MODEL ANALYSIS WAS ABOUT 3C TOO WARM AT THAT
SITE...WL MAINTAIN GOING POPS NEAR LK SUP...ESPECIALLY E OFMQT WHERE
WEAK SFC TROF IS FCST TO PERSIST THRU THE DAY. ALSO ADDED A MENTION
OF FZDZ IN THIS AREA WHERE THE LLVL MSTR REMAINS A BIT MORE
RESILIENT AND THE LLVL TEMPS ARE NOT LIKELY TO BE AS LO AS OBSVD AT
INL.
TNGT...SHRTWV RDGING WL BE DOMINATING WITH WEAK SFC HI PRES RDG
AXIS BLDG OVHD. MAINTAINED LO CHC POPS IN THE EVNG OVER THE E WHERE
THE SFC LO PRES TROF WL LINGER WHILE SLOWLY WEAKENING WITH TIME.
EXPECT THE LOWEST MIN TEMPS OVER THE INTERIOR SCNTRL WHERE SKIES WL
TREND MOCLR UNDER LIGHT SFC ACYC FLOW.
SAT...AS SHRTWV COMPLEX NOW MOVING TOWARD THE PAC NW SPLITS AND
DEEPENS TROFS IN SCNTRL CAN AND THE CENTRAL PLAINS...INCRSG SW FLOW
WL DVLP OVER THE UPR LKS AND RETURN DEEPER MSTR TO THE UPR LKS. WITH
INITIAL LLVL DRY AIR...RESTRICTED POPS MAINLY ON SAT AFT TO THE NW
HALF OF THE CWA WHERE GUIDANCE SHOWS DEEPER MOISTENING ON CYC SIDE
OF UPR JET AXIS ROTATING NEWD TOWARD THE UPR LKS BY 00Z SUN. SFC
TEMPS ARE PROGGED TO RISE AOA 32 IN THE AFTN AS H85 TEMPS RISE TO
ARND 0C...BUT NAM/SREF FCST WBLB ZERO HGT BLO 500 AGL WITH LINGERING
LLVL DRY AIR SUG VERY LTL CHC RA MAY BE MIXED WITH THE PCPN AT THE
ONSET.
SAT NGT INTO MON...MODELS HAVE BEGUN TO CONVERGE ON A SCENARIO
SHOWING A DEEPENING UPR TROF/SFC LO AS SEPARATE SHRTWVS IN SCNTRL
CAN AND THE CENTRAL PLAINS PHASE. THE GFS IS MOST AGGRESSIVE AT
DEEPENING A CLOSED LO...SHOWING A 984MB SFC LO OVER NRN LK MI BY 12Z
SUN. PER NCEP DISCUSSION...USED A BLEND OF THE INTERMEDIATE STRENGTH
00Z NAM/00Z CNDN/21Z SREF/12Z ECMWF FOR FCST PREPARATION. THESE
MODELS SHOW SFC LO TRACKING ACRS LK SUP/SRN ONTARIO SAT NGT AND
DRAWING ENUF LLVL MSTR OVER UPR MI TO SUPPORT LIKELY POPS UNDER UPR
DVGC ON CYC SIDE OF JET AXIS WHERE 12HR H5 FALLS APRCH 200M. WITH
THE ARRIVAL OF MORE LLVL MSTR OVER THE E...FCST THKNS/WBLB ZERO HGT
SUPPORT AT LEAST A MIX WITH RA IN THAT AREA. ONCE THE LO SHIFTS TO
THE NE LATE SAT NGT/SUN...STRONG NW WINDS WITH H85 WINDS AOA 50KT
ADVECT MUCH COLDER AIR INTO THE UPR LKS...SETTING UP A LK ENHANCED
SN EVENT WITH FCST SDNGS SHOWING DEEP MSTR UNDER LO HGTS AND OMEGA
WITHIN THE LOWERING DGZ AND SHARP CYC FLOW. GUSTY NW WINDS WL ALSO
RESULT IN CONSIDERABLE BLSN. THIS LK ENHANCED SN WL THEN PERSIST
INTO MON BEFORE THE DEEPER MSTR SLOWLY EXITS AND PCPN TENDS TOWARD
PURE LES BY MON NGT. CONSIDERED DOING A WATCH FOR THE NW WIND SN
BELTS...ESPECIALLY OVER THE W WHERE MOST RECENT NCEP GUIDANCE SHOWS
UP TO A FOOT OF SN THRU 12Z MON. BUT SINCE THE BULK OF THE MOST
SGNFT WX WL OCCUR IN THE 5TH TO 7TH PERIODS...OPTED TO ISSUE AN SPS
TO COVER THIS POTENTIAL WINTER STORM.
EXTENDED...LATEST GUIDANCE IN GOOD AGREEMENT SHOWING DEEP UPR TROF
GIVING WAY TO A MORE ZONAL FLOW AFT MID WEEK WITH A WARMING TREND.
DID LOWER FCST MIN TEMPS A FEW DEGREES FM THE ALLBLEND FCST OVER THE
INTERIOR W HALF ON MON NGT GIVEN ARRIVAL OF SFC RDG AXIS/LGT
WINDS/PWAT AS LO AS 0.1 INCH.
&&
.AVIATION /FOR THE 18Z TAF ISSUANCE/...
VARIABLE WINDS OVER THE AREA ARE MAKING FOR A DIFFICULT AVIATION
FCST THIS AFTN. EXPECT MOST SITES TO REMAIN WITH/OR DEVELOP MVFR
CIGS THROUGH THIS EVENING AS WINDS BECOME MORE NORTHERLY OFF LK
SUPERIOR. COULD BE SOME LGT SNOW SHOWERS/FLURRIES LATE THIS AFTN
INTO THE EVENING BUT ANY VSBY REDUCTION WOULD BE BRIEF. ONCE
CLEARING OCCURS LATE TONIGHT...MAY SEE FOG DEVELOP AT KCMX. FAIRLY
QUIET CONDITIONS WILL SETUP ON SATURDAY WITH JUST SOME HIGHER CLOUDS
STREAMING IN FM THE WEST AHEAD OF STRONG SYSTEM THAT IS FORECAST TO
BLAST INTO THE UPPER GREAT LAKES SATURDAY NIGHT.
OUTLOOK...DUE TO STRONG WINDS/HEAVY LK EFFECT SNOW...FLYING
CONDITIONS ARE EXPECTED TO BECOME VERY POOR LATE SATURDAY NIGHT
INTO NEW YEARS DAY. ADVERSE CONDITIONS...POSSIBLY AT OR BLO
AIRPORT MINS...SHOULD CONTINUE INTO MONDAY.
&&
.MARINE /FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE/...
WINDS WILL DIMINISH TODAY AS LOW PRESSURE TROUGH LINGERS OVER LAKE
SUPERIOR. A WEAK RIDGE WILL THEN SLIDE ACROSS LAKE SUPERIOR INTO
SATURDAY BEFORE A STRONG LOW DEVELOPS OVER THE PLAINS AND MOVES
NORTH OF LAKE SUPERIOR FOR NEW YEARS DAY. HIGH END GALES ARE LOOKING
LIKELY FROM THIS SYSTEM...BEGINNING ON NEW YEARS DAY AND CONTINUING
THROUGH MONDAY AS COLDER AIR PLOWS INTO THE GREAT LAKES. HEAVY
FREEZING SPRAY ALSO MAY OCCUR SUNDAY NIGHT INTO MONDAY. GALE AND
HEAVY FREEZING SPRAY WATCHES WILL LIKELY NEED TO BE ISSUED IN THE
NEXT COUPLE DAYS. WINDS DIMINISH SIGNIFICANTLY BY NEXT TUESDAY WITH
ARRIVAL OF HIGH PRESSURE RIDGE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...JLA
SYNOPSIS...KC
DISCUSSION...KC
AVIATION...JLA
MARINE...TITUS
AREA FORECAST DISCUSSION...UPDATED
NWS MARQUETTE MI
1112 AM EST FRI DEC 30 2011
.UPDATE...
NOT A WHOLE LOT OF WEATHER OF SIGNIFICANCE TODAY BUT STILL A TRICKY
UPDATE. CURRENTLY...LOW PRESSURE SYSTEM IS BRINGING MIXED PRECIPITATION
TO SOUTHERN PORTIONS OF WISCONSIN...BUT THIS SYSTEM WILL REMAIN TO
THE SOUTH OF THE CWA THROUGH THE DAY. LOW PRESSURE TROUGH EXTENDS
NORTH OF THE SFC LOW ACROSS CNTRL UPR MI. CONDITIONS ARE MAINLY DRY
THOUGH WITH EVEN SOME SUNSHINE THROUGH HIGHER CLOUDS OVR CNTRL CWA
THIS MORNING. LOW-LEVELS REMAIN VERY SATURATED OVR EASTERN CWA AND
ALONG WITH LOW CLOUDS AND FOG THERE IS LIKELY SOME FZDZ/MIST OCCURRING
AS WELL. LK EFFECT IS RESTRICTED TO CNTRL AND EASTERN LK SUPERIOR
BASED ON VISIBLE SATELLITE.
AS THE LOW TO THE SOUTH HEADS INTO LOWER MICHIGAN LATER TODAY...
EXPECT WINDS OVR MOST OF LK SUPERIOR INTO UPR MI TO BECOME MORE
NORTHERLY. THIS SHOULD ALLOW FOR SOME LK EFFECT SNOW SHOWERS TO WORK
ONSHORE OVR KEWEENAW AND ALSO IN NCNTRL UPR MI. TEMPS AT INVERSION
TOP AROUND 900MB ONLY STRUGGLE TO REACH -7C...SO FZDZ COULD OCCUR.
SEEMS LIKE THERE IS ENOUGH DRY AIR IN BLYR BASED ON SFC DEWPNT
DEPRESSIONS UP TO 4F AT KCMX/KP59 TO LIMIT THAT RISK THOUGH...AND
PROBABLY WOULD JUST SEE FLURRIES IF SNOW SHOWERS CAN NOT REALLY ADVECT
ONSHORE. TEMPS TODAY SHOULD REACH INTO THE 27-32 RANGE...COLDEST IN
THE CNTRL CWA WHERE THE CLEARING LATE LAST NIGHT ALLOWED LOWS TO DIP
TOWARD 10 ABOVE.
ALL LIGHT PRECIPITATION WILL CEASE OVERNIGHT TONIGHT AS WINDS BECOME
MORE SOUTHERLY IN ADVANCE OF STRONGER LOW PRESSURE SYSTEM MOVING
INTO THE PLAINS.
&&
PREV DISCUSSION...ISSUED AT 636 AM EST FRI DEC 30 2011...
.SYNOPSIS...
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW WNW FLOW ALF OVER
THE GRT LKS BTWN LO AMPLITUDE RDGING OVER THE W AND A TROF N JUST
OFF THE E COAST. SHRTWV RESPONSIBLE FOR SN ON THU IS PUSHING EWD
TOWARD SE ONTARIO...BUT WEAK SFC-H85 TROF REMAINS OVER ERN UPR MI.
BUT WITH DNVA/DEEP LYR QVECTOR DVGC/SUBSIDENCE/DRYING ALF IN THE
WAKE OF THE SHRTWV...THE PCPN OVER THE CWA HAS PRETTY MUCH ENDED.
THE MQT 88D DOES SHOW HIER RADAR RETURNS OVER ECNTRL LK SUP NEAR
WEAK SFC LO CENTER. 00Z INL RAOB SHOWS SHARP INVRN BASE NEAR H875
WITH TEMP JUST BLO THE INVRN DOWN TO -14C...LO ENUF TO SUPPORT LES.
ALTHOUGH THE 00Z INL RAOB INDICATES MODEST DRYING IN THE SUB INVRN
LYR...SKIES ARE GENERALLY CLDY AT MOST LOCATIONS FM THE MN ARROWHEAD
SEWD THRU UPR MI...BUT SOME BREAKS IN THE CLDS ARE EVIDENT. FARTHER
TO THE W/SW IN MN/WI...SKIES ARE MOCLR CLOSER TO WEAK SFC RDG AXIS
ASSOCIATED WITH INCOMING SHRTWV RDG MOVING E THRU MN. ANOTHER PAIR
OF SHRTWVS ARE NOTED IN THE NRN/CNTRL PLAINS...BUT THESE APPEAR TO
BE DIGGING TO THE SE. MUCH FARTHER TO THE W...A STRONG SHRTWV IS
APRCHG THE PAC NW. UPSTREAM HI TEMPS YDAY SUG MAX TEMPS WL GENERALLY
BE ARND 30.
&&
.DISCUSSION...
MAIN FCST CONCERNS THIS PACKAGE SHIFT TO POTENTIAL SN EVENT ON NEW
YEARS DAY/MON RELATED TO SHRTWV NOW APRCHG THE PAC NW.
TDAY...LOOKS LIKE A RELATIVELY QUIET DAY ON TAP WITH WEAK HGT
RISES/DRYING ALF IN THE WAKE OF DEPARTING SHRTWV. SHRTWV COMPLEX IN
THE PLAINS IS FCST TO CONSOLIDATE IN THE LOWER GRT LKS...WITH
ACCOMPANYING DEEP LYR QVECTOR CNVGC/PCPN PASSING S OF UPR MI. FCST
SDNGS SHOW INVRN BASE SINKING TO H9-925 OVER THE CWA IN THE AFTN...
WITH INVRN BASE TEMPS NO LOWER THAN ABOUT -8C. CONSIDERING
THE WEAK SFC WINDS FCST THAT WOULD NOT SUPPORT ORGANIZATION OF LES
BANDS...THE MARGINAL NATURE OF THE CHILL/DGZ ABV THE SUB INVRN
LYR...AND SOME LLVL DRYING...SUSPECT THERE WL BE LTL IN THE WAKE OF
LES. BUT SINCE THE 00Z INL RAOB DID SHOW -14C AIR AT THE H875 INVRN
BASE AND THE GFS/NAM MODEL ANALYSIS WAS ABOUT 3C TOO WARM AT THAT
SITE...WL MAINTAIN GOING POPS NEAR LK SUP...ESPECIALLY E OFMQT WHERE
WEAK SFC TROF IS FCST TO PERSIST THRU THE DAY. ALSO ADDED A MENTION
OF FZDZ IN THIS AREA WHERE THE LLVL MSTR REMAINS A BIT MORE
RESILIENT AND THE LLVL TEMPS ARE NOT LIKELY TO BE AS LO AS OBSVD AT
INL.
TNGT...SHRTWV RDGING WL BE DOMINATING WITH WEAK SFC HI PRES RDG
AXIS BLDG OVHD. MAINTAINED LO CHC POPS IN THE EVNG OVER THE E WHERE
THE SFC LO PRES TROF WL LINGER WHILE SLOWLY WEAKENING WITH TIME.
EXPECT THE LOWEST MIN TEMPS OVER THE INTERIOR SCNTRL WHERE SKIES WL
TREND MOCLR UNDER LIGHT SFC ACYC FLOW.
SAT...AS SHRTWV COMPLEX NOW MOVING TOWARD THE PAC NW SPLITS AND
DEEPENS TROFS IN SCNTRL CAN AND THE CENTRAL PLAINS...INCRSG SW FLOW
WL DVLP OVER THE UPR LKS AND RETURN DEEPER MSTR TO THE UPR LKS. WITH
INITIAL LLVL DRY AIR...RESTRICTED POPS MAINLY ON SAT AFT TO THE NW
HALF OF THE CWA WHERE GUIDANCE SHOWS DEEPER MOISTENING ON CYC SIDE
OF UPR JET AXIS ROTATING NEWD TOWARD THE UPR LKS BY 00Z SUN. SFC
TEMPS ARE PROGGED TO RISE AOA 32 IN THE AFTN AS H85 TEMPS RISE TO
ARND 0C...BUT NAM/SREF FCST WBLB ZERO HGT BLO 500 AGL WITH LINGERING
LLVL DRY AIR SUG VERY LTL CHC RA MAY BE MIXED WITH THE PCPN AT THE
ONSET.
SAT NGT INTO MON...MODELS HAVE BEGUN TO CONVERGE ON A SCENARIO
SHOWING A DEEPENING UPR TROF/SFC LO AS SEPARATE SHRTWVS IN SCNTRL
CAN AND THE CENTRAL PLAINS PHASE. THE GFS IS MOST AGGRESSIVE AT
DEEPENING A CLOSED LO...SHOWING A 984MB SFC LO OVER NRN LK MI BY 12Z
SUN. PER NCEP DISCUSSION...USED A BLEND OF THE INTERMEDIATE STRENGTH
00Z NAM/00Z CNDN/21Z SREF/12Z ECMWF FOR FCST PREPARATION. THESE
MODELS SHOW SFC LO TRACKING ACRS LK SUP/SRN ONTARIO SAT NGT AND
DRAWING ENUF LLVL MSTR OVER UPR MI TO SUPPORT LIKELY POPS UNDER UPR
DVGC ON CYC SIDE OF JET AXIS WHERE 12HR H5 FALLS APRCH 200M. WITH
THE ARRIVAL OF MORE LLVL MSTR OVER THE E...FCST THKNS/WBLB ZERO HGT
SUPPORT AT LEAST A MIX WITH RA IN THAT AREA. ONCE THE LO SHIFTS TO
THE NE LATE SAT NGT/SUN...STRONG NW WINDS WITH H85 WINDS AOA 50KT
ADVECT MUCH COLDER AIR INTO THE UPR LKS...SETTING UP A LK ENHANCED
SN EVENT WITH FCST SDNGS SHOWING DEEP MSTR UNDER LO HGTS AND OMEGA
WITHIN THE LOWERING DGZ AND SHARP CYC FLOW. GUSTY NW WINDS WL ALSO
RESULT IN CONSIDERABLE BLSN. THIS LK ENHANCED SN WL THEN PERSIST
INTO MON BEFORE THE DEEPER MSTR SLOWLY EXITS AND PCPN TENDS TOWARD
PURE LES BY MON NGT. CONSIDERED DOING A WATCH FOR THE NW WIND SN
BELTS...ESPECIALLY OVER THE W WHERE MOST RECENT NCEP GUIDANCE SHOWS
UP TO A FOOT OF SN THRU 12Z MON. BUT SINCE THE BULK OF THE MOST
SGNFT WX WL OCCUR IN THE 5TH TO 7TH PERIODS...OPTED TO ISSUE AN SPS
TO COVER THIS POTENTIAL WINTER STORM.
EXTENDED...LATEST GUIDANCE IN GOOD AGREEMENT SHOWING DEEP UPR TROF
GIVING WAY TO A MORE ZONAL FLOW AFT MID WEEK WITH A WARMING TREND.
DID LOWER FCST MIN TEMPS A FEW DEGREES FM THE ALLBLEND FCST OVER THE
INTERIOR W HALF ON MON NGT GIVEN ARRIVAL OF SFC RDG AXIS/LGT
WINDS/PWAT AS LO AS 0.1 INCH.
&&
.AVIATION /FOR THE 12Z TAF ISSUANCE/...
LIGHT LOW-LEVEL WIND REGIME THRU THIS FCST PERIOD SUGGESTS
CONDITIONS PROBABLY WILL NOT CHANGE MUCH AT KIWD/KCMX/KSAW.
SO...GIVEN THE LOW-LEVEL MOISTURE OVER THE AREA AND GENERAL MVFR
CIGS...MVFR CIGS WILL LIKELY PREVAIL THRU THE FCST PERIOD.
HOWEVER...THERE MAY BE SOME PERIODS WHERE CLOUDS SCATTER OUT OR CIGS
RISE TO VFR AS INDICATED BY CURRENT REGIONAL SFC OBS AND SATELLITE
IMAGERY.
FG AS SAW SHOULD BURN OFF THIS MORNING AS SURFACE TEMPS INCREASE.
FG MAY FORM AT CMX TONIGHT GIVEN ABUNDANT LOW LEVEL MOISTURE...IF
CLOUDS CAN CLEAR OUT ENOUGH. THE EXACT TIMING IS STILL IN QUESTION.
&&
.MARINE /FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE/...
WINDS WILL DIMINISH TODAY AS LOW PRESSURE TROUGH LINGERS OVER LAKE
SUPERIOR. A WEAK RIDGE WILL THEN SLIDE ACROSS LAKE SUPERIOR INTO
SATURDAY BEFORE A STRONG LOW DEVELOPS OVER THE PLAINS AND MOVES
NORTH OF LAKE SUPERIOR FOR NEW YEARS DAY. HIGH END GALES ARE LOOKING
LIKELY FROM THIS SYSTEM...BEGINNING ON NEW YEARS DAY AND CONTINUING
THROUGH MONDAY AS COLDER AIR PLOWS INTO THE GREAT LAKES. HEAVY
FREEZING SPRAY ALSO MAY OCCUR SUNDAY NIGHT INTO MONDAY. GALE AND
HEAVY FREEZING SPRAY WATCHES WILL LIKELY NEED TO BE ISSUED IN THE
NEXT COUPLE DAYS. WINDS DIMINISH SIGNIFICANTLY BY NEXT TUESDAY WITH
ARRIVAL OF HIGH PRESSURE RIDGE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...JLA
SYNOPSIS...KC
DISCUSSION...KC
AVIATION...TITUS
MARINE...TITUS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
636 AM EST FRI DEC 30 2011
UPDATED AVIATION DISCUSSION FOR 12Z TAFS
.SYNOPSIS...
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW WNW FLOW ALF OVER
THE GRT LKS BTWN LO AMPLITUDE RDGING OVER THE W AND A TROF N JUST
OFF THE E COAST. SHRTWV RESPONSIBLE FOR SN ON THU IS PUSHING EWD
TOWARD SE ONTARIO...BUT WEAK SFC-H85 TROF REMAINS OVER ERN UPR MI.
BUT WITH DNVA/DEEP LYR QVECTOR DVGC/SUBSIDENCE/DRYING ALF IN THE
WAKE OF THE SHRTWV...THE PCPN OVER THE CWA HAS PRETTY MUCH ENDED.
THE MQT 88D DOES SHOW HIER RADAR RETURNS OVER ECNTRL LK SUP NEAR
WEAK SFC LO CENTER. 00Z INL RAOB SHOWS SHARP INVRN BASE NEAR H875
WITH TEMP JUST BLO THE INVRN DOWN TO -14C...LO ENUF TO SUPPORT LES.
ALTHOUGH THE 00Z INL RAOB INDICATES MODEST DRYING IN THE SUB INVRN
LYR...SKIES ARE GENERALLY CLDY AT MOST LOCATIONS FM THE MN ARROWHEAD
SEWD THRU UPR MI...BUT SOME BREAKS IN THE CLDS ARE EVIDENT. FARTHER
TO THE W/SW IN MN/WI...SKIES ARE MOCLR CLOSER TO WEAK SFC RDG AXIS
ASSOCIATED WITH INCOMING SHRTWV RDG MOVING E THRU MN. ANOTHER PAIR
OF SHRTWVS ARE NOTED IN THE NRN/CNTRL PLAINS...BUT THESE APPEAR TO
BE DIGGING TO THE SE. MUCH FARTHER TO THE W...A STRONG SHRTWV IS
APRCHG THE PAC NW. UPSTREAM HI TEMPS YDAY SUG MAX TEMPS WL GENERALLY
BE ARND 30.
&&
.DISCUSSION...
MAIN FCST CONCERNS THIS PACKAGE SHIFT TO POTENTIAL SN EVENT ON NEW
YEARS DAY/MON RELATED TO SHRTWV NOW APRCHG THE PAC NW.
TDAY...LOOKS LIKE A RELATIVELY QUIET DAY ON TAP WITH WEAK HGT
RISES/DRYING ALF IN THE WAKE OF DEPARTING SHRTWV. SHRTWV COMPLEX IN
THE PLAINS IS FCST TO CONSOLIDATE IN THE LOWER GRT LKS...WITH
ACCOMPANYING DEEP LYR QVECTOR CNVGC/PCPN PASSING S OF UPR MI. FCST
SDNGS SHOW INVRN BASE SINKING TO H9-925 OVER THE CWA IN THE AFTN...
WITH INVRN BASE TEMPS NO LOWER THAN ABOUT -8C. CONSIDERING
THE WEAK SFC WINDS FCST THAT WOULD NOT SUPPORT ORGANIZATION OF LES
BANDS...THE MARGINAL NATURE OF THE CHILL/DGZ ABV THE SUB INVRN
LYR...AND SOME LLVL DRYING...SUSPECT THERE WL BE LTL IN THE WAKE OF
LES. BUT SINCE THE 00Z INL RAOB DID SHOW -14C AIR AT THE H875 INVRN
BASE AND THE GFS/NAM MODEL ANALYSIS WAS ABOUT 3C TOO WARM AT THAT
SITE...WL MAINTAIN GOING POPS NEAR LK SUP...ESPECIALLY E OFMQT WHERE
WEAK SFC TROF IS FCST TO PERSIST THRU THE DAY. ALSO ADDED A MENTION
OF FZDZ IN THIS AREA WHERE THE LLVL MSTR REMAINS A BIT MORE
RESILIENT AND THE LLVL TEMPS ARE NOT LIKELY TO BE AS LO AS OBSVD AT
INL.
TNGT...SHRTWV RDGING WL BE DOMINATING WITH WEAK SFC HI PRES RDG
AXIS BLDG OVHD. MAINTAINED LO CHC POPS IN THE EVNG OVER THE E WHERE
THE SFC LO PRES TROF WL LINGER WHILE SLOWLY WEAKENING WITH TIME.
EXPECT THE LOWEST MIN TEMPS OVER THE INTERIOR SCNTRL WHERE SKIES WL
TREND MOCLR UNDER LIGHT SFC ACYC FLOW.
SAT...AS SHRTWV COMPLEX NOW MOVING TOWARD THE PAC NW SPLITS AND
DEEPENS TROFS IN SCNTRL CAN AND THE CENTRAL PLAINS...INCRSG SW FLOW
WL DVLP OVER THE UPR LKS AND RETURN DEEPER MSTR TO THE UPR LKS. WITH
INITIAL LLVL DRY AIR...RESTRICTED POPS MAINLY ON SAT AFT TO THE NW
HALF OF THE CWA WHERE GUIDANCE SHOWS DEEPER MOISTENING ON CYC SIDE
OF UPR JET AXIS ROTATING NEWD TOWARD THE UPR LKS BY 00Z SUN. SFC
TEMPS ARE PROGGED TO RISE AOA 32 IN THE AFTN AS H85 TEMPS RISE TO
ARND 0C...BUT NAM/SREF FCST WBLB ZERO HGT BLO 500 AGL WITH LINGERING
LLVL DRY AIR SUG VERY LTL CHC RA MAY BE MIXED WITH THE PCPN AT THE
ONSET.
SAT NGT INTO MON...MODELS HAVE BEGUN TO CONVERGE ON A SCENARIO
SHOWING A DEEPENING UPR TROF/SFC LO AS SEPARATE SHRTWVS IN SCNTRL
CAN AND THE CENTRAL PLAINS PHASE. THE GFS IS MOST AGGRESSIVE AT
DEEPENING A CLOSED LO...SHOWING A 984MB SFC LO OVER NRN LK MI BY 12Z
SUN. PER NCEP DISCUSSION...USED A BLEND OF THE INTERMEDIATE STRENGTH
00Z NAM/00Z CNDN/21Z SREF/12Z ECMWF FOR FCST PREPARATION. THESE
MODELS SHOW SFC LO TRACKING ACRS LK SUP/SRN ONTARIO SAT NGT AND
DRAWING ENUF LLVL MSTR OVER UPR MI TO SUPPORT LIKELY POPS UNDER UPR
DVGC ON CYC SIDE OF JET AXIS WHERE 12HR H5 FALLS APRCH 200M. WITH
THE ARRIVAL OF MORE LLVL MSTR OVER THE E...FCST THKNS/WBLB ZERO HGT
SUPPORT AT LEAST A MIX WITH RA IN THAT AREA. ONCE THE LO SHIFTS TO
THE NE LATE SAT NGT/SUN...STRONG NW WINDS WITH H85 WINDS AOA 50KT
ADVECT MUCH COLDER AIR INTO THE UPR LKS...SETTING UP A LK ENHANCED
SN EVENT WITH FCST SDNGS SHOWING DEEP MSTR UNDER LO HGTS AND OMEGA
WITHIN THE LOWERING DGZ AND SHARP CYC FLOW. GUSTY NW WINDS WL ALSO
RESULT IN CONSIDERABLE BLSN. THIS LK ENHANCED SN WL THEN PERSIST
INTO MON BEFORE THE DEEPER MSTR SLOWLY EXITS AND PCPN TENDS TOWARD
PURE LES BY MON NGT. CONSIDERED DOING A WATCH FOR THE NW WIND SN
BELTS...ESPECIALLY OVER THE W WHERE MOST RECENT NCEP GUIDANCE SHOWS
UP TO A FOOT OF SN THRU 12Z MON. BUT SINCE THE BULK OF THE MOST
SGNFT WX WL OCCUR IN THE 5TH TO 7TH PERIODS...OPTED TO ISSUE AN SPS
TO COVER THIS POTENTIAL WINTER STORM.
EXTENDED...LATEST GUIDANCE IN GOOD AGREEMENT SHOWING DEEP UPR TROF
GIVING WAY TO A MORE ZONAL FLOW AFT MID WEEK WITH A WARMING TREND.
DID LOWER FCST MIN TEMPS A FEW DEGREES FM THE ALLBLEND FCST OVER THE
INTERIOR W HALF ON MON NGT GIVEN ARRIVAL OF SFC RDG AXIS/LGT
WINDS/PWAT AS LO AS 0.1 INCH.
&&
.AVIATION /FOR THE 12Z TAF ISSUANCE/...
LIGHT LOW-LEVEL WIND REGIME THRU THIS FCST PERIOD SUGGESTS
CONDITIONS PROBABLY WILL NOT CHANGE MUCH AT KIWD/KCMX/KSAW.
SO...GIVEN THE LOW-LEVEL MOISTURE OVER THE AREA AND GENERAL MVFR
CIGS...MVFR CIGS WILL LIKELY PREVAIL THRU THE FCST PERIOD.
HOWEVER...THERE MAY BE SOME PERIODS WHERE CLOUDS SCATTER OUT OR CIGS
RISE TO VFR AS INDICATED BY CURRENT REGIONAL SFC OBS AND SATELLITE
IMAGERY.
FG AS SAW SHOULD BURN OFF THIS MORNING AS SURFACE TEMPS INCREASE.
FG MAY FORM AT CMX TONIGHT GIVEN ABUNDANT LOW LEVEL MOISTURE...IF
CLOUDS CAN CLEAR OUT ENOUGH. THE EXACT TIMING IS STILL IN QUESTION.
&&
.MARINE /FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE/...
WINDS WILL DIMINISH TODAY AS LOW PRESSURE TROUGH LINGERS OVER LAKE
SUPERIOR. A WEAK RIDGE WILL THEN SLIDE ACROSS LAKE SUPERIOR INTO
SATURDAY BEFORE A STRONG LOW DEVELOPS OVER THE PLAINS AND MOVES
NORTH OF LAKE SUPERIOR FOR NEW YEARS DAY. HIGH END GALES ARE LOOKING
LIKELY FROM THIS SYSTEM...BEGINNING ON NEW YEARS DAY AND CONTINUING
THROUGH MONDAY AS COLDER AIR PLOWS INTO THE GREAT LAKES. HEAVY
FREEZING SPRAY ALSO MAY OCCUR SUNDAY NIGHT INTO MONDAY. GALE AND
HEAVY FREEZING SPRAY WATCHES WILL LIKELY NEED TO BE ISSUED IN THE
NEXT COUPLE DAYS. WINDS DIMINISH SIGNIFICANTLY BY NEXT TUESDAY WITH
ARRIVAL OF HIGH PRESSURE RIDGE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...KC
DISCUSSION...KC
AVIATION...TITUS
MARINE...TITUS
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
535 PM CST SAT DEC 31 2011
.AVIATION... /00Z TAF ISSUANCE/
PRECIPITATION DEVELOPING QUICKLY ACROSS SW MN ATTM BEHIND INVERTED
SURFACE TROF STRETCHING NORTH TO SOUTH ACROSS THE CENTER OF MN.
20Z HRRR HAS A GOOD HANDLE ON THE REFLECTIVITY TREND. THIS WOULD
SUGGEST THAT KRWF WILL HAVE PRECIPITATION STARTING AT TAF ISSUANCE
WITH KSTC AROUND 01Z. KAXN LOOKS TO STAY DRY WITH CEILINGS
IMPROVING TO MVFR AS NW WINDS INCREASE. SOME SLEET WAS NOTED EARLIER
AT KFSD AND LAPS PROFILE SUPPORTED A +2 DEG C LAYER AT 800 MB
WITH NEARLY A -2 DEG C LAYER AT 875 MB. SIMILAR SET UP DOWN STREAM
THIS EVENING WITH SLEET POSSIBLE OUT THE GATE FOR AN HOUR AT KRWF.
THE PROFILES COOL TO THE NORTHEAST WITH A BRIEF PERIOD OF RAIN
CHANGING TO SNOW. THE BAND OF SNOW SHOULD LAST UP TO 4 HOURS WITH
3/4 INCH PER HOUR SNOW RATES LIKELY...IF NOT HIGHER...FROM THE
TWIN CITIES ON EAST. THE BAND OF SNOW SHOULD BE EAST OF KEAU BY
09Z. IN THE WAKE OF THE TROF...NORTHWEST WINDS WILL RISE OVERNIGHT
WITH 25-30 KNOT SUSTAINED WINDS LATE IN THE NIGHT AND ON SUNDAY
WITH GUSTS IN THE 35 TO 40 KNOT RANGE. THE DIRECTION REMAINS FROM
300 TO 310 DEGREES. MVFR CEILINGS LIKELY THROUGH THE DAY ON SUNDAY
WITH OVC015-020 IN MORNING AND OVC020-025 IN THE AFTERNOON.
KMSP...LATEST GUIDANCE WOULD HAVE PRECIPITATION INTO THE AIRFIELD
BETWEEN 01Z AND 02Z. IT WOULD START AS RAIN...BUT CHANGE TO SNOW
WITHIN AN HOUR. SNOW EXPECTED FROM 02Z TO 06Z WITH RATES AROUND
3/4 INCH PER HOUR. CEILINGS DROPPING BELOW 010 IN THE SNOW WITH
VISIBILITY A 1/2 MILE. RAPID IMPROVEMENT AFTER 06Z ALONG WITH
INCREASING NORTHWEST WINDS. NORTHWEST 20 TO 25 KNOTS SUSTAINED LATE
IN THE NIGHT INCREASING TO 25 TO 30 KNOTS ON SUNDAY. GUSTS RIGHT
NOW INDICATED IN THE 35 KNOT RANGE ON SUNDAY WITH POTENTIAL FOR
45 TO 50 KNOT GUSTS AFTER 16Z THROUGH THE END OF THE TAF (02/06Z).
DIRECTION OF 300 TO 310 STILL FAVORED.
&&
.DISCUSSION... /ISSUED 309 PM CST SAT DEC 31 2011/
RATHER TRICKY FORECAST FOR THE OVERNIGHT WITH SUCH A FAST
MOVING SYSTEM AND A NARROW WINDOW OF OPPORTUNITY FOR FOR SNOW
ACCUMS AND STRONG WINDS TO COME TOGETHER. WILL CONTINUE WITH THE
WINTER STORM WARNINGS/ADVISORIES...MAIN ISSUE IS THE CONCERN OF A
VERY RAPID WX CHANGE FROM MILD TEMPS AND DRY CONDS THIS AFTN TO
RAPID ONSET OF PCPN DURING NEXT FEW HOURS AND THEN VERY RAPID
TRANSISTION TO SNOW WITH NW WINDS PICKING UP. SNOW AMOUNTS WILL
NOT BE ALL THAT GREAT...IN THE 1 TO 4 INCH RANGE WITH MOST OF THE
ACCUMULATION IN ONLY A FEW HOURS.
WV IMAGERY SHOWS ONE VORT NOW MOVING ACRS N MN PRODUCING SOME MDT
SNOW NEAR THE CNDN BORDER. MORE POTENT VORT NOW DIVING SE ACROSS
NEBRASKA PANHANDLE INTO NW KS. THIS TROF HAD 200 METER 500 MB
HEIGHT FALLS AT 12Z IN RIK WITH MODELS MAINTAINING THIS STRENGTH
AT IT THEN MOVES EAST TONIGHT ACRS IA/MO INTO WI/IL BY 12Z AND
BECOMES MORE NEGATIVELY TILTED. 12Z NAM WAS SHOWING 700 MB LOW
BECOMING CLOSED AS IT MOVED ACROSS IA TONIGHT...WITH 18Z RUNS NOW
MORE OF AN OPEN WAVE CLOSER TO GFS/EC. 18Z NAM ALSO SHOWING
SURFACE LOW AND 500 MB HEIGHT FALL CENTER TRACKING A BIT FARTHER
S. THIS POSES SOME CONCERN WITH SNOW AMOUNTS...BUT HEADLINES ARE
AS MUCH FOR COMBO OF STRONG WINDS AS WITH THE SNOW AMOUNTS.
SURFACE LOW CURRENTLY IN SW MN WILL WILL CONTINUE TO FILL AS THE
LOW IN SW IA TAKES OVER AHEAD OF UPPER TROF. NW WINDS HAVE BEGUN
TO INCREASE IN SW MN WITH GUSTS NOW 25 TO 30 MPH AND TEMPS
BEGINNING TO FALL ON THE SODAK BORDER. PCPN SHOULD STILL BEGIN TO
EXPAND IN SW INTO CENTRAL MN DURING THE NEXT FEW HOURS AND THEN
REACH THE MSP AREA AROUND 03Z. TRANSITION TO SNOW SHOULD OCCUR
RAPIDLY AS NW WINDS INCREASE ON BACKSIDE OF IOWA LOW PRESSURE. 600
MB FULL WIND FRONTOGENESIS REMAINS PRETTY IMPRESSIVE AT 00Z ACROSS
SW INTO CENTRAL MN AND INTO THE EC AN SE BY 06Z. BY 06Z THE
ACCUMULATING SNOW SHOULD BE CONFINED TO SE/EC MN INTO WI AND DONE
ACROSS THE AREA BY 12Z.
WILL CONTINUE WITH THE WIND ADVISORY HEADLINES AS WELL. THE
STRONGEST BLAST OF WINDS WILL PROBABABLY BE ACROSS IA WHERE
PRESSURE RISE CENTER SWEEPS ACROSS AS WELL AS STRONG NVA IN WAKE
OF UPPER TROF. STILL LOOKS GOOD FOR 30 MPH SUSTAINED WITH SOME GUSTS
40 TO 50 MPH....ESPECIALLY IN SC MN.
STILL A SMALL CHANCE OF -SN MAINLY IN WC WI TUESDAY NIGHT AS
MODELS STILL PRETTY CONSISTENT ON BRINGING FAST MOVING SHORT WAVE
DOWN EAST SIDE OF UPPER RIDGE. WARMING TREND BEGINNING MID WEEK
WITH TEMPS FALLING CLOSER TO NORMAL AGAIN LATE IN WEEK AS FLOW
BECOMES MORE NW.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WINTER STORM WARNING FROM 9 PM THIS EVENING TO 6 AM CST SUNDAY
FOR ANOKA-CHISAGO-DAKOTA-HENNEPIN-ISANTI-LE SUEUR-RAMSEY-
RICE-SCOTT-STEELE-WASECA-WASHINGTON.
WIND ADVISORY FROM 6 AM SUNDAY TO MIDNIGHT CST SUNDAY NIGHT FOR
ANOKA-BENTON-BLUE EARTH-CARVER-CHISAGO-DAKOTA-GOODHUE-
HENNEPIN-ISANTI-KANABEC-LE SUEUR-MCLEOD-MEEKER-MILLE LACS-
NICOLLET-RAMSEY-RICE-SCOTT-SHERBURNE-SIBLEY-STEELE-WASECA-
WASHINGTON-WRIGHT.
WIND ADVISORY UNTIL MIDNIGHT CST SUNDAY NIGHT FOR CHIPPEWA-
DOUGLAS-LAC QUI PARLE-POPE-STEVENS-SWIFT-YELLOW MEDICINE.
WINTER WEATHER ADVISORY UNTIL 3 AM CST SUNDAY FOR KANDIYOHI-
MORRISON-REDWOOD-RENVILLE-STEARNS-TODD.
WIND ADVISORY FROM 3 AM SUNDAY TO MIDNIGHT CST SUNDAY NIGHT FOR
BROWN-FARIBAULT-FREEBORN-KANDIYOHI-MARTIN-MORRISON-REDWOOD-
RENVILLE-STEARNS-TODD-WATONWAN.
WINTER STORM WARNING UNTIL 6 AM CST SUNDAY FOR BENTON-BLUE EARTH-
BROWN-CARVER-FARIBAULT-KANABEC-MARTIN-MCLEOD-MEEKER-MILLE
LACS-NICOLLET-SHERBURNE-SIBLEY-WATONWAN-WRIGHT.
WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 6 AM CST
SUNDAY FOR FREEBORN-GOODHUE.
WI...WINTER STORM WARNING FROM 9 PM THIS EVENING TO 6 AM CST SUNDAY
FOR BARRON-POLK-ST. CROIX.
WIND ADVISORY FROM 6 AM SUNDAY TO MIDNIGHT CST SUNDAY NIGHT FOR
BARRON-CHIPPEWA-DUNN-EAU CLAIRE-PEPIN-PIERCE-POLK-RUSK-ST.
CROIX.
WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 6 AM CST
SUNDAY FOR CHIPPEWA-DUNN-EAU CLAIRE-PEPIN-PIERCE-RUSK.
&&
$$
RAH/BAP
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
1153 PM CST SAT DEC 31 2011
...UPDATE TO AVIATION...
.UPDATE...
/ISSUED 940 PM CST SAT DEC 31 2011/
THERE IS A LITTLE LULL IN THE WINDS RIGHT NOW WITH PRESSURE THE
GRADIENT WEAKENING SOMEWHAT CLOSE TO A PREFRONTAL TROUGH OVER THE
AREA. THE TRUE EDGE OF COLDER AIR IS NOW JUST GETTING READY TO
MOVE INTO OUR WESTERN COUNTIES. MADE SOME UPWARD ADJUSTMENT ON
TEMPERATURES OVERNIGHT BASED ON TRENDS. USED THE RUC AND NAM AS
GENERAL GUIDANCE.
ADDED A BRIEF PERIOD OF POST FRONTAL CLOUDS TO THE GRIDS OVERNIGHT
FOR MOST OF THE CWFA WITH THE EXCEPTION OF THE FAR SOUTHERN CWFA.
SPRINKLES/VERY LIGHT RAIN NOT OUT OF THE QUESTION IN CNTRL MO AS
WELL.
WINDS ARE EXPECTED TO PICK UP WITH POST FRONTAL PRESSURE RISES
OVERNIGHT. THE STRONGEST WINDS WILL LIKELY OCCUR OVER THE NORTHERN
HALF OF THE CWFA AND ALONG THE MO OZARK PLATEAU AND POINTS NORTH
CLOSER TO SFC LOW PRESSURE AND STRONGER SFC PRESSURE RISES. NO
CHANGES PLANNED TO THE ADVISORY.
DSA
&&
.SHORT TERM (LATE THIS AFTERNOON THROUGH TONIGHT)...
/314 PM CST SAT DEC 31 2011/
SURFACE PRESSURE GRADIENTS CONTINUE TO TIGHTEN ACROSS THE REGION
AS LOW PRESSURE IN THE CENTRAL PLAINS DEEPENS AHEAD OF AN
APPROACHING MID/UPPER LEVEL WAVE. EXPECT TO SEE SOUTHERLY WINDS
STAY QUITE GUSTY THIS AFTERNOON...ESPECIALLY ALONG AND WEST OF
U.S. 71. WENT AHEAD WITH A WIND ADVISORY STARTING 18Z FOR THE
SOUTHEASTERN KS AND WESTERN MOST TIER OF MISSOURI COUNTIES TO
ACCOUNT FOR THE STRONG SOUTHERLY WINDS. IN ADDITION...A RED FLAG
WARNING REMAINS IN EFFECT FOR AREAS GENERALLY ALONG AND NORTHWEST
OF A KIMBERLING CITY TO HOUSTON TO ROLLA LINE THROUGH 00Z. SEE THE
FIRE WEATHER DISCUSSION BELOW FOR MORE DETAIL.
AROUND SUNSET...DO EXPECT TO SEE A MARGINAL DECREASE IN
WINDS...THOUGH THEY WILL REMAIN GUSTY FROM THE SOUTH AHEAD OF AN
APPROACHING COLD FRONT. RIGHT NOW...EXPECT THAT FRONT TO BEGIN TO
MAKE IT INTO THE WESTERN MOST PORTIONS OF THE CWA BETWEEN 23Z AND
01Z...THE CENTRAL PORTIONS...INCLUDING SGF...BETWEEN 02Z AND
05Z...AND THE EASTERN CWA AROUND MIDNIGHT. THAT BEING SAID...WILL
NEED TO WATCH FOR A FASTER FROPA WITH SUCH STRONG PRESSURE RISES
BEHIND THE FRONT.
ONCE THE FRONT PASSES...WINDS WILL RAPIDLY TURN TO THE WEST AND
NORTHWEST...AND SPEEDS WILL INCREASE SUBSTANTIALLY...WITH
SUSTAINED WINDS 30 TO 35 MPH...AND GUSTS OVER 45 MPH EXPECTED. A
WIND ADVISORY IS IN EFFECT FOR THE ENTIRE CWA THIS EVENING
THROUGH MOST OF THE OVERNIGHT TO ACCOUNT FOR THIS. WE WILL HAVE TO
WATCH ISALLOBARIC TRENDS CLOSELY TONIGHT. IF THE MAIN PRESSURE
FALL/RISE COUPLET SHIFTS SLIGHTLY FURTHER SOUTH...IT IS FEASIBLE
THAT PORTIONS OF CENTRAL MISSOURI COULD APPROACH HIGH WIND
CRITERIA.
AS THE PARENT LOW PRESSURE SYSTEM REALLY WINDS UP ACROSS THE
SOUTHERN GREAT LAKES TONIGHT...WE WILL HAVE TO WATCH FOR WRAP
AROUND MOISTURE GETTING INTO CENTRAL MISSOURI. AT THIS
TIME...THINK THIS WILL MAINLY RESULT IN A FEW HOURS OF INCREASED
CLOUDS ACROSS THIS REGION. OTHERWISE...WENT FAIRLY CLOSE TO MOS
NUMBERS FOR OVERNIGHT LOWS.
BOXELL/SCHAUMANN
&&
.LONG TERM (SUNDAY THROUGH FRIDAY)...
/314 PM CST SAT DEC 31 2011/
COLD AND BLUSTERY CONDITIONS WILL THEN CONTINUE FROM SUNDAY INTO
MONDAY AS STRONG HIGH PRESSURE BEGINS TO BUILD IN FROM THE
NORTHWEST. TEMPERATURES WILL ACTUALLY BE BELOW NORMAL FOR A
CHANGE...ESPECIALLY FROM MONDAY INTO MONDAY NIGHT. LOW
TEMPERATURES MONDAY NIGHT ARE EXPECTED TO FALL WELL INTO THE TEENS
OVER THE EASTERN OZARKS. AREAS OUT WEST MAY NOT GET AS COLD...BUT
THAT WILL DEPEND HEAVILY ON WHERE THAT SURFACE HIGH AND ASSOCIATED
RIDGE AXIS END UP.
SOUTHERLY WINDS WILL THEN KICK BACK IN STARTING ON TUESDAY AS THAT
RIDGE AXIS SLIDES ON BY. THIS WILL ALSO MARK THE START OF A
MODEST WARMING TREND...AT LEAST INITIALLY. ONE THING WE WILL ALSO
HAVE TO WATCH TOWARDS THE MIDDLE OF NEXT WEEK IS FIRE WEATHER AS
THE LOW LEVEL AIRMASS WILL BE AWFULLY DRY.
LONG WAVE CHARTS CONTINUE TO INDICATE A NORTHWEST FLOW ALOFT
LOSING ITS GRIP BY LATE NEXT WORK WEEK...WITH A ZONAL FLOW TAKING
OVER. THIS WILL RESULT IN A MUCH MORE PRONOUNCED WARMING TREND AS
WE GET INTO THURSDAY AND FRIDAY. TEMPERATURES WELL INTO THE
50S...OR EVEN THE 60S LOOK LIKE A GOOD BET.
MEDIUM RANGE MODELS CONTINUE TO GIVE AT LEAST A WEAK SIGNAL FOR AN
UPPER LEVEL SYSTEM PASSING THROUGH THE REGION FROM LATE FRIDAY
INTO SATURDAY. HAVE INCLUDED SOME TOKEN SLIGHT CHANCE POPS FOR
FRIDAY NIGHT...BUT CONFIDENCE IN MOISTURE AVAILABILITY IS LOW.
SCHAUMANN
&&
.AVIATION...
/ISSUED 1141 PM CST SAT DEC 31 2011/
FOR THE 01/0600Z KSGF/KJLN/KBBG TAFS...LOW PRESSURE OVER EASTERN
IOWA WITH A TRAILING COLD FRONT OVER THE WESTERN MO OZARKS WILL
SHIFT EAST OVERNIGHT. AS THE WINDS VEER WNW-NW...GUSTS OF 30-40KTS
WILL BE POSSIBLE FOR A BRIEF PERIOD BEFORE GRADUALLY DIMINISHING
TOWARD DAYBREAK 11Z-12Z. MODERATELY GUSTY WINDS WILL CONTINUE
THROUGH MUCH OF THE DAY SUNDAY BEFORE DIMINISHING SOMEWHAT LATE IN
THE TAF PERIOD AS SFC RIDGING OVER THE PLAINS APPROACHES FROM THE
WEST.
DSA
&&
.FIRE WEATHER...
WILL LET THE RED FLAG WARNING GO AT 6 PM. A BRIEF LULL IN THE WIND
WILL OCCUR EARLY THIS EVENING WITH PRESSURE GRADIENT RELAXING
SOMEWHAT NEAR A DRY COLD FRONT...BUT WNW WINDS WILL PICK UP AGAIN
LATER THIS EVENING AND OVERNIGHT BEHIND THE FRONT. TEMPERATURES
WILL COOL OVERNIGHT BEHIND THE FRONT AND AS A RESULT WE WILL SEE A
DECENT...BUT NOT GREAT...HUMIDITY RECOVERY OVERNIGHT.
EXPECT A BUSY WEEK FOR FIRE WEATHER WITH A LACK OF SIGNIFICANT
MOISTURE AND A COUPLE OF ESSENTIALLY DRY FRONTAL PASSAGES.
DSA
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...WIND ADVISORY UNTIL 6 AM CST SUNDAY FOR MOZ055>058-066>071-
077>083-088>098-101>106.
KS...WIND ADVISORY UNTIL 6 AM CST SUNDAY FOR KSZ073-097-101.
&&
$$
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
951 PM CST SAT DEC 31 2011
.UPDATE...
/ISSUED 940 PM CST SAT DEC 31 2011/
THERE IS A LITTLE LULL IN THE WINDS RIGHT NOW WITH PRESSURE THE
GRADIENT WEAKENING SOMEWHAT CLOSE TO A PREFRONTAL TROUGH OVER THE
AREA. THE TRUE EDGE OF COLDER AIR IS NOW JUST GETTING READY TO
MOVE INTO OUR WESTERN COUNTIES. MADE SOME UPWARD ADJUSTMENT ON
TEMPERATURES OVERNIGHT BASED ON TRENDS. USED THE RUC AND NAM AS
GENERAL GUIDANCE.
ADDED A BRIEF PERIOD OF POST FRONTAL CLOUDS TO THE GRIDS OVERNIGHT
FOR MOST OF THE CWFA WITH THE EXCEPTION OF THE FAR SOUTHERN CWFA.
SPRINKLES/VERY LIGHT RAIN NOT OUT OF THE QUESTION IN CNTRL MO AS
WELL.
WINDS ARE EXPECTED TO PICK UP WITH POST FRONTAL PRESSURE RISES
OVERNIGHT. THE STRONGEST WINDS WILL LIKELY OCCUR OVER THE NORTHERN
HALF OF THE CWFA AND ALONG THE MO OZARK PLATEAU AND POINTS NORTH
CLOSER TO SFC LOW PRESSURE AND STRONGER SFC PRESSURE RISES. NO
CHANGES PLANNED TO THE ADVISORY.
DSA
&&
.SHORT TERM (LATE THIS AFTERNOON THROUGH TONIGHT)...
/314 PM CST SAT DEC 31 2011/
SURFACE PRESSURE GRADIENTS CONTINUE TO TIGHTEN ACROSS THE REGION
AS LOW PRESSURE IN THE CENTRAL PLAINS DEEPENS AHEAD OF AN
APPROACHING MID/UPPER LEVEL WAVE. EXPECT TO SEE SOUTHERLY WINDS
STAY QUITE GUSTY THIS AFTERNOON...ESPECIALLY ALONG AND WEST OF
U.S. 71. WENT AHEAD WITH A WIND ADVISORY STARTING 18Z FOR THE
SOUTHEASTERN KS AND WESTERN MOST TIER OF MISSOURI COUNTIES TO
ACCOUNT FOR THE STRONG SOUTHERLY WINDS. IN ADDITION...A RED FLAG
WARNING REMAINS IN EFFECT FOR AREAS GENERALLY ALONG AND NORTHWEST
OF A KIMBERLING CITY TO HOUSTON TO ROLLA LINE THROUGH 00Z. SEE THE
FIRE WEATHER DISCUSSION BELOW FOR MORE DETAIL.
AROUND SUNSET...DO EXPECT TO SEE A MARGINAL DECREASE IN
WINDS...THOUGH THEY WILL REMAIN GUSTY FROM THE SOUTH AHEAD OF AN
APPROACHING COLD FRONT. RIGHT NOW...EXPECT THAT FRONT TO BEGIN TO
MAKE IT INTO THE WESTERN MOST PORTIONS OF THE CWA BETWEEN 23Z AND
01Z...THE CENTRAL PORTIONS...INCLUDING SGF...BETWEEN 02Z AND
05Z...AND THE EASTERN CWA AROUND MIDNIGHT. THAT BEING SAID...WILL
NEED TO WATCH FOR A FASTER FROPA WITH SUCH STRONG PRESSURE RISES
BEHIND THE FRONT.
ONCE THE FRONT PASSES...WINDS WILL RAPIDLY TURN TO THE WEST AND
NORTHWEST...AND SPEEDS WILL INCREASE SUBSTANTIALLY...WITH
SUSTAINED WINDS 30 TO 35 MPH...AND GUSTS OVER 45 MPH EXPECTED. A
WIND ADVISORY IS IN EFFECT FOR THE ENTIRE CWA THIS EVENING
THROUGH MOST OF THE OVERNIGHT TO ACCOUNT FOR THIS. WE WILL HAVE TO
WATCH ISALLOBARIC TRENDS CLOSELY TONIGHT. IF THE MAIN PRESSURE
FALL/RISE COUPLET SHIFTS SLIGHTLY FURTHER SOUTH...IT IS FEASIBLE
THAT PORTIONS OF CENTRAL MISSOURI COULD APPROACH HIGH WIND
CRITERIA.
AS THE PARENT LOW PRESSURE SYSTEM REALLY WINDS UP ACROSS THE
SOUTHERN GREAT LAKES TONIGHT...WE WILL HAVE TO WATCH FOR WRAP
AROUND MOISTURE GETTING INTO CENTRAL MISSOURI. AT THIS
TIME...THINK THIS WILL MAINLY RESULT IN A FEW HOURS OF INCREASED
CLOUDS ACROSS THIS REGION. OTHERWISE...WENT FAIRLY CLOSE TO MOS
NUMBERS FOR OVERNIGHT LOWS.
BOXELL/SCHAUMANN
&&
.LONG TERM (SUNDAY THROUGH FRIDAY)...
/314 PM CST SAT DEC 31 2011/
COLD AND BLUSTERY CONDITIONS WILL THEN CONTINUE FROM SUNDAY INTO
MONDAY AS STRONG HIGH PRESSURE BEGINS TO BUILD IN FROM THE
NORTHWEST. TEMPERATURES WILL ACTUALLY BE BELOW NORMAL FOR A
CHANGE...ESPECIALLY FROM MONDAY INTO MONDAY NIGHT. LOW
TEMPERATURES MONDAY NIGHT ARE EXPECTED TO FALL WELL INTO THE TEENS
OVER THE EASTERN OZARKS. AREAS OUT WEST MAY NOT GET AS COLD...BUT
THAT WILL DEPEND HEAVILY ON WHERE THAT SURFACE HIGH AND ASSOCIATED
RIDGE AXIS END UP.
SOUTHERLY WINDS WILL THEN KICK BACK IN STARTING ON TUESDAY AS THAT
RIDGE AXIS SLIDES ON BY. THIS WILL ALSO MARK THE START OF A
MODEST WARMING TREND...AT LEAST INITIALLY. ONE THING WE WILL ALSO
HAVE TO WATCH TOWARDS THE MIDDLE OF NEXT WEEK IS FIRE WEATHER AS
THE LOW LEVEL AIRMASS WILL BE AWFULLY DRY.
LONG WAVE CHARTS CONTINUE TO INDICATE A NORTHWEST FLOW ALOFT
LOSING ITS GRIP BY LATE NEXT WORK WEEK...WITH A ZONAL FLOW TAKING
OVER. THIS WILL RESULT IN A MUCH MORE PRONOUNCED WARMING TREND AS
WE GET INTO THURSDAY AND FRIDAY. TEMPERATURES WELL INTO THE
50S...OR EVEN THE 60S LOOK LIKE A GOOD BET.
MEDIUM RANGE MODELS CONTINUE TO GIVE AT LEAST A WEAK SIGNAL FOR AN
UPPER LEVEL SYSTEM PASSING THROUGH THE REGION FROM LATE FRIDAY
INTO SATURDAY. HAVE INCLUDED SOME TOKEN SLIGHT CHANCE POPS FOR
FRIDAY NIGHT...BUT CONFIDENCE IN MOISTURE AVAILABILITY IS LOW.
SCHAUMANN
&&
.AVIATION...
/ISSUED 542 PM CST SAT DEC 31 2011/
FOR THE 01/0000Z KSGF/KJLN/KBBG TAFS...A COLD FRONT WILL MOVE
THROUGH THE TAF SITES EARLY IN THE TAF PERIOD. GUSTY WINDS WILL
CONTINUE...ESPECIALLY BEHIND THE FRONT. WILL CONTINUE TO CARRY LOW
LEVEL WIND SHEAR AT ALL TAFS SITES THROUGH 15Z.. A BRIEF PERIOD OF
POST FRONTAL MVFR CEILINGS WILL BE POSSIBLE TONIGHT...BUT EXPECTED
THAT TO BE SHORT LIVED. MODERATELY GUSTY WINDS WILL CONTINUE
DURING THE DAY SUNDAY WITH A DECENT PRESSURE GRADIENT OVER THE
REGION BETWEEN EXITING LOW PRESSURE OVER THE GREAT LAKES AND A
RIDGE OF HIGH PRESSURE OVER THE PLAINS.
DSA
&&
.FIRE WEATHER...
WILL LET THE RED FLAG WARNING GO AT 6 PM. A BRIEF LULL IN THE WIND
WILL OCCUR EARLY THIS EVENING WITH PRESSURE GRADIENT RELAXING
SOMEWHAT NEAR A DRY COLD FRONT...BUT WNW WINDS WILL PICK UP AGAIN
LATER THIS EVENING AND OVERNIGHT BEHIND THE FRONT. TEMPERATURES
WILL COOL OVERNIGHT BEHIND THE FRONT AND AS A RESULT WE WILL SEE A
DECENT...BUT NOT GREAT...HUMIDITY RECOVERY OVERNIGHT.
EXPECT A BUSY WEEK FOR FIRE WEATHER WITH A LACK OF SIGNIFICANT
MOISTURE AND A COUPLE OF ESSENTIALLY DRY FRONTAL PASSAGES.
DSA
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...WIND ADVISORY UNTIL 6 AM CST SUNDAY FOR MOZ055>058-067>071-
078>083-089>092-094>098-102>106.
WIND ADVISORY UNTIL 3 AM CST SUNDAY FOR MOZ066-077-088-093-101.
KS...WIND ADVISORY UNTIL 3 AM CST SUNDAY FOR KSZ073-097-101.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS GLASGOW MT
930 AM MST FRI DEC 30 2011
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH SUNDAY...
SENT AN UPDATE THIS MORNING TO ADJUST...ADD...AND FINE TUNE THE
PLACEMENT AND TIMING OF SPRINKLES AND LIGHT RAIN ACCORDING TO
CURRENT RADAR TRENDS AND HRRR MODEL DEPICTIONS LEADING INTO THE
TONIGHT TIME FRAME. IT LOOKS LIKE THERE COULD BE SOME SCATTERED
SPRINKLES AS THE SYSTEM GET ORGANIZED AHEAD OF THE LINEAR
PRECIPITATION FEATURE TONIGHT. ALSO LOWERED TEMPERATURES JUST A
BIT DUE TO MORE EXPECTED CLOUD COVER. BMICKELSON
PREVIOUS SHORT TERM DISCUSSION...WINDS HAVE FINALLY DIMINISHED TO
10 KNOTS OR LESS ACROSS NORTHEAST MONTANA AT 10Z. THE LIGHT WINDS
WILL BE SHORT LIVED AS THE NEXT COLD FRONT MOVES THROUGH TONIGHT
WITH A CHANCE OF RAIN OR SNOW. THE FRONT WILL BE FOLLOWED BY
STRONG WEST TO NORTHWEST WINDS ON SATURDAY. HAVE ISSUED A HIGH
WIND WATCH FOR THE ENTIRE FORECAST AREA FOR SATURDAY AND SATURDAY
EVENING.
SHORTWAVE RIDGE WILL BRING MILD WEATHER TO THE AREA TODAY BUT IT
WILL NOT BE AS WARM AS IT WAS YESTERDAY. CLOUDS WILL INCREASE
AHEAD OF A COLD FRONT THAT WILL MOVE THROUGH EASTERN MONTANA
TONIGHT. DEEPER MOISTURE MOVES INTO THE AREA THIS EVENING ON
SOUTHWEST FLOW ALOFT. THIS WILL BRING A CHANCE OF RAIN STARTING
THIS EVENING WITH THE BEST CHANCE OF RAIN SOUTH OF THE MISSOURI
RIVER. AS TEMPERATURES COOL ALOFT TONIGHT...RAIN MAY MIX WITH SNOW
BEFORE IT MOVES TO THE EAST SATURDAY MORNING.
UPPER TROUGH MOVES THROUGH THE AREA ON SATURDAY WITH DECENT COLD
AIR ADVECTION. 850 MB WINDS INCREASE TO AROUND 50 KNOTS (GFS
SOMEWHAT STRONGER, ECMWF SOMEWHAT WEAKER) SATURDAY MORNING AND
REMAIN THERE INTO SATURDAY EVENING. WITH GOOD MIXING AND MOMENTUM
TRANSFER EXPECTED ALONG WITH OVER 20 MB PRESSURE RISE...WINDS HAVE A
GOOD CHANCE OF REACHING WARNING CRITERIA OF 40 MPH SUSTAINED WITH
GUSTS TO 58 MPH. THE STRONGEST WINDS WILL BE IN THE EAST BUT NOT
READY TO RULE OUT THE WEST REACHING HIGH WIND CRITERIA. WILL
INCLUDE THE ENTIRE FORECAST AREA IN THE HIGH WIND WATCH FOR
SATURDAY AND SATURDAY EVENING. COLD AIR ADVECTION WILL LIMIT
TEMPERATURE RISES ON SATURDAY AND THE NORTHERN ZONES MAY SEE A FEW
FLAKES OF WRAP AROUND SNOW FROM AN UPPER LOW MOVING THROUGH SASKATCHEWAN.
HIGH PRESSURE WILL MOVE INTO THE AREA SATURDAY NIGHT. SKIES WILL
GRADUALLY CLEAR AND WINDS WILL SLOWLY DIMINISH. TEMPERATURES WILL
BE COLDER THAN THEY HAVE BEEN FOR SEVERAL DAYS. THE COLD AIR WILL
LINGER INTO SUNDAY WHILE THE NEXT RIDGE BUILDS IN FROM THE WEST. FORRESTER
.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY...
THE EXTENDED PERIOD BEGINS WITH AN UPPER LEVEL RIDGE AXIS OVER THE
ROCKY MOUNTAINS AND NORTHWESTERLY FLOW ALOFT OVER EASTERN MONTANA.
THE APPROACHING RIDGE SENDS A WARM FRONT INTO THE FORECAST AREA
SUNDAY NIGHT AND MONDAY. THIS WILL ONCE AGAIN RAMP TEMPERATURES
ABOVE NORMAL ON MONDAY.
MONDAY NIGHT...THE GFS...AND TO A LESSER EXTENT THE EC...PICK UP A
DRY SHORTWAVE TROUGH THAT WILL KNOCK DOWN THE RIDGE AND RAMP UP
WINDS A BIT THROUGH TUESDAY MORNING.
TUESDAY...THE RIDGE RE-ESTABLISHES ITSELF WITH TEMPERATURES
TRENDING WELL ABOVE NORMAL...WITH POSSIBLY RECORD HIGHS. THIS
RIDGE WILL MAINTAIN RELATIVELY WARM AND DRY CONDITIONS THROUGH
THURSDAY.
THURSDAY NIGHT AND FRIDAY...AN EASTERN PACIFIC UPPER TROUGH AND
STORM SYSTEM SLAMS INTO THE WEST COAST WEDNESDAY NIGHT...THEN
SWINGS EAST ACROSS THE DIVIDE BY FRIDAY. 850MB TEMPERATURES
QUICKLY FALL TO AROUND -10*C. WITH PRECIPITATION A POSSIBILITY
THERE SHOULD BE A TRANSITION FROM RAIN TO SNOW WITH THIS WAVE.
THIS WILL BECOME A WINTER STORM OVER WESTERN AND CENTRAL
MONTANA...SOME OF WHICH MAY AFFECT OUR WESTERN ZONES FOR A SHORT
PERIOD. THIS WAVE WILL ALSO TREND TEMPERATURE DOWN TOWARDS NORMAL.
SCT
&&
.AVIATION...
VFR TODAY. A SHORT PERIOD UPPER RIDGE WILL BE INTERRUPTED BY A
SHORTWAVE TROUGH THIS AFTERNOON WHICH COULD INTRODUCE RAIN AND
SNOW SHOWERS THIS EVENING...AFFECTING MAINLY KGDV AND KSDY. THIS
COULD PRODUCE MVFR CEILINGS. EXPECT NW WINDS TO BECOME SOUTHERLY
THIS AFTERNOON...THEN SOUTHWESTERLY THIS EVENING...ALL AROUND
5-10KTS. SCT
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WATCH FROM SATURDAY MORNING THROUGH SATURDAY EVENING
FOR CENTRAL AND SOUTHEAST PHILLIPS...CENTRAL AND SOUTHERN
VALLEY...DANIELS...SHERIDAN...WESTERN ROOSEVELT...PETROLEUM...
GARFIELD...MCCONE...RICHLAND...DAWSON...PRAIRIE...WIBAUX...
NORTHERN PHILLIPS...SOUTHWEST PHILLIPS...NORTHERN VALLEY...
EASTERN ROOSEVELT.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1130 PM CST SAT DEC 31 2011
.AVIATION...
WINDS WILL BE MAIN CONCERN FOR AVIATION OVER WESTERN NEBRASKA
TONIGHT. STRONG NORTHWEST WINDS OF 20 TO 30 MPH WITH GUSTS TO AROUND
40 MPH WILL CONTINUE OVER NORTH CENTRAL NEBRASKA THROUGH THE EARLY
MORNING BETWEEN KANW AND KONL. CLEAR SKIES AND VFR CONDITIONS ARE
EXPECTED OVER WESTERN NEBRASKA THROUGH SUNDAY.
&&
.PREV DISCUSSION... /ISSUED 850 PM CST SAT DEC 31 2011/
UPDATE...
UPDATED TO REMOVE WIND ADVISORY AND REDUCE CLOUD COVER OVER
WESTERN AND NORTH CENTRAL NEBRASKA. STILL BREEZY OVER NORTH
CENTRAL NEBRASKA BUT WILL CONTINUE TO DIMINISH THROUGH THE EARLY
MORNING HOURS. TEMPERATURES LOOK TO BE ON TRACK.
PREV DISCUSSION... /ISSUED 659 PM CST SAT DEC 31 2011/
UPDATE...
UPDATING FORECAST TO DROP HIGH WIND WARNING AND CUT BACK ON WIND
ADVISORY. WINDS HAVE FALLEN OFF OVER THE WEST WILL CONTINUE
ADVISORY OVER NORTH CENTRAL NEBRASKA EAST OF A LINE FROM AINSWORTH
TO BROKEN BOW. TOOK PRECIPITATION OUT OF THE FORECAST AND
INCREASED CLOUD COVER OVER NORTH CENTRAL NEBRASKA THROUGH 6Z. THIS
ALL REFLECTS TRENDS.
PREV DISCUSSION... /ISSUED 545 PM CST SAT DEC 31 2011/
AVIATION...
WINDS WILL BE MAIN CONCERN FOR AVIATION OVER WESTERN NEBRASKA
TONIGHT. WINDS WILL DIMINISH AFTER MIDNIGHT. SKIES WILL SLOWLY CLEAR
FORM WEST TO EAST.
PREV DISCUSSION... /ISSUED 243 PM CST SAT DEC 31 2011/
DISCUSSION...
IT LOOKS LIKE THE BEST WINDS ARE PASSING SOUTH AND WEST OF THE
FCST AREA THIS AFTERNOON. THE PV15 PRESSURE SFC IS NOTICEABLY
FARTHER SOUTH ON SATELLITE AND IN THE RUC THAN PREVIOUS MODEL
SOLNS SUGGESTED. IT APPEARS THE ENTIRE WIND FIELD HAS SHIFTED
SOUTHWEST ACROSS THE FAR SRN NEB PANHANDLE...NERN COLO AND WRN KS. THUS
THE HIGH WIND WARNING AND PARTS OF THE WIND ADVISORY MAY BE
CANCELLED EITHER LATE THIS AFTERNOON OR EARLY THIS EVENING.
THE MODELS ALSO MOVE A PRETTY GOOD AREA OF RAIN AND SNOW FARTHER
SOUTH THROUGH SWRN NEB. THIS PCPN SHOULD EXIT THE FCST AREA BY
AROUND 03Z ACCORDING TO THE HRRR WHICH HAS SHOWN GOOD SKILL TODAY
WITH PCPN FCSTS BUT NOT HIGH WIND GUSTS WHICH NEVER MATERIALIZED
AS EXPECTED.
GENERALLY CLEAR SKIES ARE EXPECTED AREA WIDE BY ROUGHLY 03Z-06Z
AND STRONG PACIFIC HIGH PRESSURE WILL BUILD SLOWLY INTO THE NRN
AND CNTL PLAINS SUNDAY. ANOTHER WINDY DAY IS EXPECTED ALONG AND
EAST OF HIGHWAY 83 AND THE BEST GUESS USING MET/MAV GUIDANCE AND
500M AGL WINDS IS SPEEDS WILL BE 25 TO 30 MPH WITH GUSTS TO 40
MPH...JUST BELOW WIND ADVISORY CRITERIA.
PACIFIC HIGH PRESSURE WILL STRENGTHEN DIRECTLY ACROSS THE FCST
AREA SUNDAY NIGHT AND MONDAY MORNING PRODUCING LOWS IN THE SINGLE
DIGITS IN MANY AREAS. THIS HIGH WILL MOVE SOUTH AND EAST MONDAY
WITH A NEW LOW PRESSURE TROF DEVELOPING ACROSS THE NRN HIGH
PLAINS. THIS TROF MOVES EAST TUESDAY WITH A WARMING TREND AND
HIGHS IN THE 40S TO NEAR 50.
LONG TERM...
WEDNESDAY THROUGH SATURDAY. AN UPPER LEVEL RIDGE OF HIGH
PRESSURE WILL TRANSLATE EAST FROM THE ROCKIES INTO THE CENTRAL
PLAINS DURING THE PERIOD. THIS WILL KEEP THE MILD AND MAINLY DRY
WEATHER PATTERN IN PLACE. MODELS CONTINUE TO AGREE THAT THURSDAY
WILL BE THE WARMEST DAY...AS 850 MB TEMPERATURES OF +15C COMBINE
WITH A WESTERLY DOWNSLOPE WIND AND BRING POSSIBLE RECORD HIGHS /IN
THE 60S/ TO PARTS OF THE AREA. MODELS AGREE THAT A COLD FRONT WILL
BRING COOLER WEATHER TO THE AREA FRIDAY AND SATURDAY AS A TROUGH OF
LOW PRESSURE DEVELOPS ACROSS THE WESTERN CONUS.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM/EXTENDED...POWER/CDC
AVIATION...POWER
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
850 PM CST SAT DEC 31 2011
.UPDATE...
UPDATED TO REMOVE WIND ADVISORY AND REDUCE CLOUD COVER OVER
WESTERN AND NORTH CENTRAL NEBRASKA. STILL BREEZY OVER NORTH
CENTRAL NEBRASKA BUT WILL CONTINUE TO DIMINISH THROUGH THE EARLY
MORNING HOURS. TEMPERATURES LOOK TO BE ON TRACK.
&&
.PREV DISCUSSION... /ISSUED 659 PM CST SAT DEC 31 2011/
UPDATE...
UPDATING FORECAST TO DROP HIGH WIND WARNING AND CUT BACK ON WIND
ADVISORY. WINDS HAVE FALLEN OFF OVER THE WEST WILL CONTINUE
ADVISORY OVER NORTH CENTRAL NEBRASKA EAST OF A LINE FROM AINSWORTH
TO BROKEN BOW. TOOK PRECIPITATION OUT OF THE FORECAST AND
INCREASED CLOUD COVER OVER NORTH CENTRAL NEBRASKA THROUGH 6Z. THIS
ALL REFLECTS TRENDS.
PREV DISCUSSION... /ISSUED 545 PM CST SAT DEC 31 2011/
AVIATION...
WINDS WILL BE MAIN CONCERN FOR AVIATION OVER WESTERN NEBRASKA
TONIGHT. WINDS WILL DIMINISH AFTER MIDNIGHT. SKIES WILL SLOWLY CLEAR
FORM WEST TO EAST.
PREV DISCUSSION... /ISSUED 243 PM CST SAT DEC 31 2011/
DISCUSSION...
IT LOOKS LIKE THE BEST WINDS ARE PASSING SOUTH AND WEST OF THE
FCST AREA THIS AFTERNOON. THE PV15 PRESSURE SFC IS NOTICEABLY
FARTHER SOUTH ON SATELLITE AND IN THE RUC THAN PREVIOUS MODEL
SOLNS SUGGESTED. IT APPEARS THE ENTIRE WIND FIELD HAS SHIFTED
SOUTHWEST ACROSS THE FAR SRN NEB PANHANDLE...NERN COLO AND WRN KS. THUS
THE HIGH WIND WARNING AND PARTS OF THE WIND ADVISORY MAY BE
CANCELLED EITHER LATE THIS AFTERNOON OR EARLY THIS EVENING.
THE MODELS ALSO MOVE A PRETTY GOOD AREA OF RAIN AND SNOW FARTHER
SOUTH THROUGH SWRN NEB. THIS PCPN SHOULD EXIT THE FCST AREA BY
AROUND 03Z ACCORDING TO THE HRRR WHICH HAS SHOWN GOOD SKILL TODAY
WITH PCPN FCSTS BUT NOT HIGH WIND GUSTS WHICH NEVER MATERIALIZED
AS EXPECTED.
GENERALLY CLEAR SKIES ARE EXPECTED AREA WIDE BY ROUGHLY 03Z-06Z
AND STRONG PACIFIC HIGH PRESSURE WILL BUILD SLOWLY INTO THE NRN
AND CNTL PLAINS SUNDAY. ANOTHER WINDY DAY IS EXPECTED ALONG AND
EAST OF HIGHWAY 83 AND THE BEST GUESS USING MET/MAV GUIDANCE AND
500M AGL WINDS IS SPEEDS WILL BE 25 TO 30 MPH WITH GUSTS TO 40
MPH...JUST BELOW WIND ADVISORY CRITERIA.
PACIFIC HIGH PRESSURE WILL STRENGTHEN DIRECTLY ACROSS THE FCST
AREA SUNDAY NIGHT AND MONDAY MORNING PRODUCING LOWS IN THE SINGLE
DIGITS IN MANY AREAS. THIS HIGH WILL MOVE SOUTH AND EAST MONDAY
WITH A NEW LOW PRESSURE TROF DEVELOPING ACROSS THE NRN HIGH
PLAINS. THIS TROF MOVES EAST TUESDAY WITH A WARMING TREND AND
HIGHS IN THE 40S TO NEAR 50.
LONG TERM...
WEDNESDAY THROUGH SATURDAY. AN UPPER LEVEL RIDGE OF HIGH
PRESSURE WILL TRANSLATE EAST FROM THE ROCKIES INTO THE CENTRAL
PLAINS DURING THE PERIOD. THIS WILL KEEP THE MILD AND MAINLY DRY
WEATHER PATTERN IN PLACE. MODELS CONTINUE TO AGREE THAT THURSDAY
WILL BE THE WARMEST DAY...AS 850 MB TEMPERATURES OF +15C COMBINE
WITH A WESTERLY DOWNSLOPE WIND AND BRING POSSIBLE RECORD HIGHS /IN
THE 60S/ TO PARTS OF THE AREA. MODELS AGREE THAT A COLD FRONT WILL
BRING COOLER WEATHER TO THE AREA FRIDAY AND SATURDAY AS A TROUGH OF
LOW PRESSURE DEVELOPS ACROSS THE WESTERN CONUS.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM/EXTENDED...POWER/CDC
AVIATION...POWER
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
545 PM CST SAT DEC 31 2011
.AVIATION...
WINDS WILL BE MAIN CONCERN FOR AVIATION OVER WESTERN NEBRASKA
TONIGHT. WINDS WILL DIMINISH AFTER MIDNIGHT. SKIES WILL SLOWLY CLEAR
FORM WEST TO EAST.
&&
.PREV DISCUSSION... /ISSUED 243 PM CST SAT DEC 31 2011/
DISCUSSION...
IT LOOKS LIKE THE BEST WINDS ARE PASSING SOUTH AND WEST OF THE
FCST AREA THIS AFTERNOON. THE PV15 PRESSURE SFC IS NOTICEABLY
FARTHER SOUTH ON SATELLITE AND IN THE RUC THAN PREVIOUS MODEL
SOLNS SUGGESTED. IT APPEARS THE ENTIRE WIND FIELD HAS SHIFTED
SOUTHWEST ACROSS THE FAR SRN NEB PANHANDLE...NERN COLO AND WRN KS. THUS
THE HIGH WIND WARNING AND PARTS OF THE WIND ADVISORY MAY BE
CANCELLED EITHER LATE THIS AFTERNOON OR EARLY THIS EVENING.
THE MODELS ALSO MOVE A PRETTY GOOD AREA OF RAIN AND SNOW FARTHER
SOUTH THROUGH SWRN NEB. THIS PCPN SHOULD EXIT THE FCST AREA BY
AROUND 03Z ACCORDING TO THE HRRR WHICH HAS SHOWN GOOD SKILL TODAY
WITH PCPN FCSTS BUT NOT HIGH WIND GUSTS WHICH NEVER MATERIALIZED
AS EXPECTED.
GENERALLY CLEAR SKIES ARE EXPECTED AREA WIDE BY ROUGHLY 03Z-06Z
AND STRONG PACIFIC HIGH PRESSURE WILL BUILD SLOWLY INTO THE NRN
AND CNTL PLAINS SUNDAY. ANOTHER WINDY DAY IS EXPECTED ALONG AND
EAST OF HIGHWAY 83 AND THE BEST GUESS USING MET/MAV GUIDANCE AND
500M AGL WINDS IS SPEEDS WILL BE 25 TO 30 MPH WITH GUSTS TO 40
MPH...JUST BELOW WIND ADVISORY CRITERIA.
PACIFIC HIGH PRESSURE WILL STRENGTHEN DIRECTLY ACROSS THE FCST
AREA SUNDAY NIGHT AND MONDAY MORNING PRODUCING LOWS IN THE SINGLE
DIGITS IN MANY AREAS. THIS HIGH WILL MOVE SOUTH AND EAST MONDAY
WITH A NEW LOW PRESSURE TROF DEVELOPING ACROSS THE NRN HIGH
PLAINS. THIS TROF MOVES EAST TUESDAY WITH A WARMING TREND AND
HIGHS IN THE 40S TO NEAR 50.
LONG TERM...
WEDNESDAY THROUGH SATURDAY. AN UPPER LEVEL RIDGE OF HIGH
PRESSURE WILL TRANSLATE EAST FROM THE ROCKIES INTO THE CENTRAL
PLAINS DURING THE PERIOD. THIS WILL KEEP THE MILD AND MAINLY DRY
WEATHER PATTERN IN PLACE. MODELS CONTINUE TO AGREE THAT THURSDAY
WILL BE THE WARMEST DAY...AS 850 MB TEMPERATURES OF +15C COMBINE
WITH A WESTERLY DOWNSLOPE WIND AND BRING POSSIBLE RECORD HIGHS /IN
THE 60S/ TO PARTS OF THE AREA. MODELS AGREE THAT A COLD FRONT WILL
BRING COOLER WEATHER TO THE AREA FRIDAY AND SATURDAY AS A TROUGH OF
LOW PRESSURE DEVELOPS ACROSS THE WESTERN CONUS.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...HIGH WIND WARNING UNTIL 9 PM CST/
8 PM MST/ THIS EVENING FOR NEZ004-022-023-035-056>059-069>071.
WIND ADVISORY UNTIL 9 PM CST /8 PM MST/ THIS EVENING FOR
NEZ005>010-024>029-036>038-094.
&&
$$
SHORT TERM/EXTENDED...TAYLOR/CDC
AVIATION...POWER
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1035 PM MST SAT DEC 31 2011
.AVIATION...06Z TAFS
BREEZY NORTHWEST WINDS WILL CONTINUE THROUGH SUNDAY ACROSS THE
PLAINS OF WESTERN SOUTH DAKOTA. BKN CIGS OF 6000-9000FT AGL ACROSS
PORTIONS OF NORTHEAST WYOMING AND WESTERN SOUTH DAKOTA WILL
GRADUALLY DISSIPATE OVERNIGHT.
&&
.PREV DISCUSSION... /ISSUED 705 PM MST SAT DEC 31 2011/
UPDATE...WINDS HAVE DROPPED BELOW ADVISORY CRITERIA ACROSS ALL OF
THE AREA. HAVE UPDATED FORECAST TO DROP WIND ADVISORY.
PREV DISCUSSION... /ISSUED 443 PM MST SAT DEC 31 2011/
UPDATE...CURRENT SURFACE MAP SHOWS HIGH PRESSURE ACROSS WESTERN
MONTANA INTO WYOMING. PRESSURE GRADIENT ACROSS WESTERN SOUTH
DAKOTA GRADUALLY WEAKENING. CURRENT WINDS AT OR JUST BELOW THE LOW
END OF ADVISORY CRITERIA ACROSS MUCH OF WESTERN SOUTH DAKOTA.
18Z NAM/21Z RUC CONTINUE TO SHOW SOME DECREASE IN WINDS OVERNIGHT.
WILL UPDATE FORECAST TO DOWNGRADE HIGH WIND WARNING TO ADVISORY.
PREV DISCUSSION... /ISSUED 229 PM MST SAT DEC 31 2011/
DISCUSSION...18Z SURFACE ANALYSIS HAS COLD FRONT RACING EAST
INTO MINNESOTA AND IOWA WITH HIGH PRESSURE BUILDING INTO THE
NORTHERN ROCKIES. TEMPERATURES ARE MAINLY IN THE 30S AND LOWER 40S
WITH STRONG NORTHWEST WINDS. REGIONAL RADAR HAS PRECIPITATION
ENDING ACROSS MUCH OF WESTERN SOUTH DAKOTA NORTH OF INTERSTATE 90.
LIGHT RAIN AND SNOW STILL FALLING ACROSS SOUTH CENTRAL SOUTH
DAKOTA. UPPER LEVEL ANALYSIS HAS TROF SWINGING THROUGH THE
NORTHERN PLAINS WITH RIDGE BUILDING OVER THE WESTERN CONUS.
LATE THIS AFTERNOON AND TONIGHT...RAIN AND SNOW WILL PUSH EAST OF
THE AREA BY EARLY EVENING WITH ONLY SOME ISOLATED SNOW SHOWERS
PERSISTING OVER THE NORTHERN BLACK HILLS THROUGH MID EVENING.
WINDY CONDITIONS WILL CONTINUE ACROSS THE SOUTH DAKOTA PLAINS THIS
EVENING DECENT MIXING...CONTINUED COLD AIR ADVECTION...AND 5-7 MB
PRESSURE RISES SLIDE SOUTH OUT OF NORTH DAKOTA. LATEST GUIDANCE
HAS BACKED OFF ON WIND SPEEDS OVERNIGHT AND INTO SUNDAY
MORNING...SO ANTICIPATE HIGH WIND WARNING TO BE CONVERTED OVER TO
A WIND ADVISORY SOMETIME THIS EVENING...AND PERSIST THROUGH SUNDAY
MORNING. BY LATE SUNDAY MORNING...HIGH PRESSURE WILL MOVE SLOWLY
EAST INTO THE REGION...WITH WINDS DECREASING FROM WEST TO EAST
DURING THE AFTERNOON. SKIES WILL BE MOSTLY SUNNY WITH SEASONABLY
COLD TEMPERATURES...HIGHS IN THE UPPER 20S TO MID 30S AT MOST
LOCATIONS. A COLD SUNDAY NIGHT CAN BE EXPECTED AS HIGH PRESSURE
SETTLES OVER THE NORTHERN PLAINS. LOWS WILL GENERALLY BE IN THE 5
TO 15 DEGREE RANGE.
AS HIGH MOVES EAST OF THE AREA ON MONDAY...WINDS WILL BECOME
SOUTHERLY ACROSS THE AREA...ALLOWING WARMER AIR TO MOVE IN. HIGHS
WILL RANGE FROM THE 40S OVER NORTHEASTERN WY AND THE BLACK HILLS
AREA...TO THE MID 30S OVER CENTRAL SD. MILDER AIR WILL PUSH EAST
ACROSS THE REST OF THE AREA MONDAY NIGHT...WITH LOWS ONLY IN THE
20S AND LOWER 30S.
EXTENDED...AN UPPER LEVEL RIDGE WILL DOMINATE THE WEATHER TUESDAY
THROUGH THURSDAY...LEADING TO SIGNIFICANTLY WARMER THAN AVERAGE
TEMPERATURES. THE RIDGE WILL BREAK DOWN ON FRIDAY LEADING TO COOLER
TEMPERATURES AND SMALL CHANCES FOR PRECIPITATION OVER PARTS OF
NORTHEASTERN WYOMING AND THE BLACK HILLS...ALTHOUGH MODEL SOLUTIONS
CONTINUE TO DIVERGE FOR FRIDAY THROUGH THE WEEKEND LEADING TO LOW
FORECAST CONFIDENCE FOR THOSE PERIODS.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...07
LONG TERM....WFO UNR
AVIATION...07
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1033 PM CST SAT DEC 31 2011
.DISCUSSION.../ISSUED AT 850 PM CST/
AREA OF LIGHT SNOW CONTINUES TO PULL OFF TO OUR EAST LATE THIS
EVENING. SNOWFALL REPORTS IN OUR SOUTHERN MOST MINNESOTA AND
NORTHERN MOST IOWA ZONES HAVE BEEN RUNNING AROUND 1 TO 2 INCHES.
TEMPERATURES THROUGH THE EVENING HAVE REMAINED JUST AT OR ABOVE
FREEZING WHEN SNOWFALL WAS OCCURRING...THEN RISING A DEGREE OR TWO
WHEN SNOWFALL CEASES. AS A RESULT...SNOW THAT FELL REMAINED VERY
SLUSHY...AND EVEN WITH WINDS PICKING UP WILL HAVE A HARD TIME
BLOWING AROUND. IN LIGHT OF THAT...REMOVED NORTHERN ROW OF OUR
MINNESOTA COUNTIES FROM THE HEADLINES WHERE LITTLE SNOW FELL...AND
ALSO REMOVED SOUTHERN IOWA COUNTIES AS LITTLE PRECIPITATION HAS
FALLEN...AND MUCH OF THAT IN THE FORM OF RAIN. DOWNGRADED WINTER
STORM WARNING TO AN ADVISORY OVER THE REMAINDER OF THE COUNTIES
UNDER HEADLINES...WHERE AROUND 2 INCHES HAVE ACCUMULATED AND ROADS
HAVE BECOME SLUSHY AND SLICK. CURRENT RADAR TRENDS WOULD INDICATE
THAT MOST OF THE PRECIPITATION WILL EXIT OUR FAR EAST BY AROUND 10
PM...THOUGH KEPT HEADLINES GOING THROUGH MIDNIGHT WITH SOME SLUSHY
ROADS AND NEW YEARS EVE TRAVELERS. UPDATES OUT.
&&
.AVIATION.../FOR THE 06Z TAF ISSUANCE/
SNOW HAS MOVED EAST OF THE AREA AND ANY LINGERING MVFR-IFR CEILINGS
IN SOUTHWEST MN/NORTHWEST IOWA SHOULD IMPROVE TO VFR BY 07Z. STRONG
NORTHWEST WINDS ARE GREATER AVIATION CONCERN THROUGH THE NEXT 24
HOURS. FREQUENT GUSTS OF 25-35KT LIKELY OVERNIGHT THROUGH 15Z-17Z
SUNDAY. THEREAFTER...COOLING ALOFT WILL ALLOW FOR STRONGER GUSTS OF
35-40KTS...WITH THESE STRONG WINDS PERSISTING THROUGH 02/00Z ACROSS
SOUTHEAST SD. FARTHER EAST IN SOUTHWEST MN/NORTHWEST IOWA...WIND
GUSTS OF 25-35KT WILL CONTINUE INTO SUNDAY EVENING. /JH
&&
.PREV DISCUSSION.../ISSUED AT 335 PM CST/
LATEST RUC...NAM AND HRRR CONTINUE TO BE IN FAIRLY CLOSE AGREEMENT
WITH PRECIPITATION DEVELOPING LATE THIS AFTERNOON AND EVENING...
ESPECIALLY ALONG AND EAST OF INTERSTATE 29 ALONG AXIS OF STRONG H85
FRONTOGENESIS...WITH VERY LITTLE PRECIPITATION TO THE WEST. CURRENT
RADAR STARTING TO SHOW PRECIPITATION DEVELOPING OVER SOUTHEAST SOUTH
DAKOTA AHEAD OF SHORT WAVE AND WOULD EXPECT PRECIPITATION TO BECOME
MORE WIDESPREAD. COLD FRONT ALREADY MOVING EAST OF I29 AND SHOULD
MOVE THROUGH NORTHWEST IOWA AND SOUTHWEST MINNESOTA BY 01Z. LOOKS
LIKE DYNAMIC COOLING OF THE LAYER SHOULD NOT BE A PROBLEM AND RAIN
SHOULD CHANGE OVER TO SNOW FAIRLY QUICKLY AS UPPER WAVE APPROACHES.
LIKE TO SEE A QUICK 2 TO 4 INCH SNOW OVER FAR EASTERN CWA WITH AN 1
TO 2 INCHES BETWEEN I29 AND THE HEAVIEST SNOW. ADD THE STRONG WINDS
WITH THE SNOW AND WILL SEE SOME PRETTY BACK CONDITIONS FROM 00Z TO
06Z AND WILL KEEP WARNING GOING ACROSS THE FAR EAST WITH WINTER
WEATHER ADVISORY CONTINUING JUST TO THE WEST. EVEN THROUGH SNOWFALL
WILL NOT REACH WINTER STORMS CRITERIA...THE COMBINATION OF WIND AND
SNOW...PLUS THE HOLIDAY EVE MAKES IT REASONABLE TO ISSUE SINCE THERE
WILL BE PLENTY PEOPLE TRAVELING. SNOW SHOULD QUICKLY END AFTER 05Z
OR 06Z AS SYSTEM PULLS AWAY. WILL ALSO KEEP THE WIND ADVISORIES
GOING THROUGH SUNDAY WITH WIND GUST TO 35 TO 45 MPH TONIGHT AS
SYSTEM GETS WOUND UP.
WITH THESE CONTINUED STRONG WINDS SUNDAY WILL COME SOME LOW CLOUDS
IN THE COOLER AIR...MAINLY TO THE NORTHEAST HALF OF THE FORECAST
AREA. WHILE A FEW FLURRIES ARE NOT OUT OF THE QUESTION...HAVE
ELECTED TO GO WITHOUT FOR NOW. UPPER SYSTEM WILL BE PULLING EAST
STEADILY AND THE LOW CLOUD DECK IS EXPECTED TO GET PRETTY THIN.
ANOTHER THOUGHT IS WILL THERE BE ANY LINGERING BLOWING SNOW IN THE
FAR EAST AND HAVE LEFT THAT OUT AS WELL WITH MARGINAL ACCUMULATIONS
AND AT LEAST 6 HOURS WITHOUT ANY FALLING SNOW BEFORE THE START OF
THE DAY.
CLEARING LOOKS STRONG FOR SUNDAY NIGHT. KEEPING WIND ADVISORY IS
MARGINAL BUT AS EVENING WINDS SHOW A VERY SMALL DECREASE ON MODELS
WILL KEEP AS IS FOR SOME MN AND IA COUNTIES THROUGH MIDNIGHT.
COLDER...BUT YES STILL A LITTLE ABOVE NORMAL...TEMPERATURES SUNDAY
WILL COOL MODESTLY SUNDAY NIGHT WITH THE SLOW WIND DECREASE. MONDAY
SHOULD THEN BE FAIRLY SUNNY WITH SOME INCREASING HIGH THIN CLOUDS
AND A TAD COOLER THAN SUNDAY ON HIGHS...BUT OF COURSE WITH MUCH
LIGHTER WINDS AS SURFACE RIDGE MOVES OVER AREA. WARMING STARTS
MONDAY NIGHT AND CONTINUES THROUGH PASSAGE OF WEAK TUESDAY SHORT
WAVE WHICH WILL BRING ONLY SOME ASSOCIATED CLOUD COVER AND NO
PRECIPITATION. WARMING WITH FAIRLY CLEAR SKIES WILL CONTINUE
WEDNESDAY AND PEAK THURSDAY WITH A POTENTIAL FOR RECORD HIGH
TEMPERATURES THURSDAY...AT LEAST HERE AT FSD WHERE WE HAVE OUR
CURRENTLY LATEST SUB 50 DAILY RECORD HIGH FOR THAT DATE. FRIDAY AND
SATURDAY LOOKS LIKE COOLING AND PROBABLY UNEVENTFUL...WITH LITTLE OR
NO PRECIPITATION AND WINDS BEHIND FRIDAY COLD FRONT FOR NOW
PROJECTED TO BE LESS THAN CURRENT SYSTEM. / WILLIAMS
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...WIND ADVISORY UNTIL 6 PM CST SUNDAY FOR IAZ001-012-020-031.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR IAZ002-
003-013-014.
WIND ADVISORY UNTIL MIDNIGHT CST SUNDAY NIGHT FOR IAZ002-013-021-
032.
WIND ADVISORY FROM MIDNIGHT TONIGHT TO MIDNIGHT CST SUNDAY NIGHT
FOR IAZ003-014-022.
MN...WIND ADVISORY UNTIL 6 PM CST SUNDAY FOR MNZ098.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR MNZ081-
089-090.
WIND ADVISORY UNTIL MIDNIGHT CST SUNDAY NIGHT FOR MNZ071-072-080-
089-097.
WIND ADVISORY FROM MIDNIGHT TONIGHT TO MIDNIGHT CST SUNDAY NIGHT
FOR MNZ081-090.
NE...WIND ADVISORY UNTIL 6 PM CST SUNDAY FOR NEZ013-014.
SD...WIND ADVISORY UNTIL 6 PM CST SUNDAY FOR SDZ038>040-050-052>071.
&&
$$
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
705 PM MST SAT DEC 31 2011
.UPDATE...WINDS HAVE DROPPED BELOW ADVISORY CRITERIA ACROSS ALL OF
THE AREA. HAVE UPDATED FORECAST TO DROP WIND ADVISORY.
&&
.AVIATION...00Z TAFS
WINDS WILL CONTINUE TO DECREASE OVERNIGHT. VFR CONDITIONS
EXPECTED WITH SOME BKN050-080 CLOUDS SPREADING INTO NORTHEAST
WYOMING AND WESTERN SOUTH DAKOTA.
&&
.PREV DISCUSSION... /ISSUED 443 PM MST SAT DEC 31 2011/
UPDATE...CURRENT SURFACE MAP SHOWS HIGH PRESSURE ACROSS WESTERN
MONTANA INTO WYOMING. PRESSURE GRADIENT ACROSS WESTERN SOUTH
DAKOTA GRADUALLY WEAKENING. CURRENT WINDS AT OR JUST BELOW THE LOW
END OF ADVISORY CRITERIA ACROSS MUCH OF WESTERN SOUTH DAKOTA.
18Z NAM/21Z RUC CONTINUE TO SHOW SOME DECREASE IN WINDS OVERNIGHT.
WILL UPDATE FORECAST TO DOWNGRADE HIGH WIND WARNING TO ADVISORY.
PREV DISCUSSION... /ISSUED 229 PM MST SAT DEC 31 2011/
DISCUSSION...18Z SURFACE ANALYSIS HAS COLD FRONT RACING EAST
INTO MINNESOTA AND IOWA WITH HIGH PRESSURE BUILDING INTO THE
NORTHERN ROCKIES. TEMPERATURES ARE MAINLY IN THE 30S AND LOWER 40S
WITH STRONG NORTHWEST WINDS. REGIONAL RADAR HAS PRECIPITATION
ENDING ACROSS MUCH OF WESTERN SOUTH DAKOTA NORTH OF INTERSTATE 90.
LIGHT RAIN AND SNOW STILL FALLING ACROSS SOUTH CENTRAL SOUTH
DAKOTA. UPPER LEVEL ANALYSIS HAS TROF SWINGING THROUGH THE
NORTHERN PLAINS WITH RIDGE BUILDING OVER THE WESTERN CONUS.
LATE THIS AFTERNOON AND TONIGHT...RAIN AND SNOW WILL PUSH EAST OF
THE AREA BY EARLY EVENING WITH ONLY SOME ISOLATED SNOW SHOWERS
PERSISTING OVER THE NORTHERN BLACK HILLS THROUGH MID EVENING.
WINDY CONDITIONS WILL CONTINUE ACROSS THE SOUTH DAKOTA PLAINS THIS
EVENING DECENT MIXING...CONTINUED COLD AIR ADVECTION...AND 5-7 MB
PRESSURE RISES SLIDE SOUTH OUT OF NORTH DAKOTA. LATEST GUIDANCE
HAS BACKED OFF ON WIND SPEEDS OVERNIGHT AND INTO SUNDAY
MORNING...SO ANTICIPATE HIGH WIND WARNING TO BE CONVERTED OVER TO
A WIND ADVISORY SOMETIME THIS EVENING...AND PERSIST THROUGH SUNDAY
MORNING. BY LATE SUNDAY MORNING...HIGH PRESSURE WILL MOVE SLOWLY
EAST INTO THE REGION...WITH WINDS DECREASING FROM WEST TO EAST
DURING THE AFTERNOON. SKIES WILL BE MOSTLY SUNNY WITH SEASONABLY
COLD TEMPERATURES...HIGHS IN THE UPPER 20S TO MID 30S AT MOST
LOCATIONS. A COLD SUNDAY NIGHT CAN BE EXPECTED AS HIGH PRESSURE
SETTLES OVER THE NORTHERN PLAINS. LOWS WILL GENERALLY BE IN THE 5
TO 15 DEGREE RANGE.
AS HIGH MOVES EAST OF THE AREA ON MONDAY...WINDS WILL BECOME
SOUTHERLY ACROSS THE AREA...ALLOWING WARMER AIR TO MOVE IN. HIGHS
WILL RANGE FROM THE 40S OVER NORTHEASTERN WY AND THE BLACK HILLS
AREA...TO THE MID 30S OVER CENTRAL SD. MILDER AIR WILL PUSH EAST
ACROSS THE REST OF THE AREA MONDAY NIGHT...WITH LOWS ONLY IN THE
20S AND LOWER 30S.
EXTENDED...AN UPPER LEVEL RIDGE WILL DOMINATE THE WEATHER TUESDAY
THROUGH THURSDAY...LEADING TO SIGNIFICANTLY WARMER THAN AVERAGE
TEMPERATURES. THE RIDGE WILL BREAK DOWN ON FRIDAY LEADING TO COOLER
TEMPERATURES AND SMALL CHANCES FOR PRECIPITATION OVER PARTS OF
NORTHEASTERN WYOMING AND THE BLACK HILLS...ALTHOUGH MODEL SOLUTIONS
CONTINUE TO DIVERGE FOR FRIDAY THROUGH THE WEEKEND LEADING TO LOW
FORECAST CONFIDENCE FOR THOSE PERIODS.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...07
LONG TERM....WFO UNR
AVIATION...07
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
443 PM MST SAT DEC 31 2011
.UPDATE...CURRENT SURFACE MAP SHOWS HIGH PRESSURE ACROSS WESTERN
MONTANA INTO WYOMING. PRESSURE GRADIENT ACROSS WESTERN SOUTH
DAKOTA GRADUALLY WEAKENING. CURRENT WINDS AT OR JUST BELOW THE LOW
END OF ADVISORY CRITERIA ACROSS MUCH OF WESTERN SOUTH DAKOTA.
18Z NAM/21Z RUC CONTINUE TO SHOW SOME DECREASE IN WINDS OVERNIGHT.
WILL UPDATE FORECAST TO DOWNGRADE HIGH WIND WARNING TO ADVISORY.
&&
.AVIATION...00Z TAFS
WINDS WILL CONTINUE TO DECREASE OVERNIGHT. VFR CONDITIONS
EXPECTED WITH SOME BKN050-080AGL CLOUDS SPREADING INTO NORTHEAST
WYOMING AND WESTERN SOUTH DAKOTA.
&&
PREV DISCUSSION... /ISSUED 229 PM MST SAT DEC 31 2011/
DISCUSSION...18Z SURFACE ANALYSIS HAS COLD FRONT RACING EAST
INTO MINNESOTA AND IOWA WITH HIGH PRESSURE BUILDING INTO THE
NORTHERN ROCKIES. TEMPERATURES ARE MAINLY IN THE 30S AND LOWER 40S
WITH STRONG NORTHWEST WINDS. REGIONAL RADAR HAS PRECIPITATION
ENDING ACROSS MUCH OF WESTERN SOUTH DAKOTA NORTH OF INTERSTATE 90.
LIGHT RAIN AND SNOW STILL FALLING ACROSS SOUTH CENTRAL SOUTH
DAKOTA. UPPER LEVEL ANALYSIS HAS TROF SWINGING THROUGH THE
NORTHERN PLAINS WITH RIDGE BUILDING OVER THE WESTERN CONUS.
LATE THIS AFTERNOON AND TONIGHT...RAIN AND SNOW WILL PUSH EAST OF
THE AREA BY EARLY EVENING WITH ONLY SOME ISOLATED SNOW SHOWERS
PERSISTING OVER THE NORTHERN BLACK HILLS THROUGH MID EVENING.
WINDY CONDITIONS WILL CONTINUE ACROSS THE SOUTH DAKOTA PLAINS THIS
EVENING DECENT MIXING...CONTINUED COLD AIR ADVECTION...AND 5-7 MB
PRESSURE RISES SLIDE SOUTH OUT OF NORTH DAKOTA. LATEST GUIDANCE
HAS BACKED OFF ON WIND SPEEDS OVERNIGHT AND INTO SUNDAY
MORNING...SO ANTICIPATE HIGH WIND WARNING TO BE CONVERTED OVER TO
A WIND ADVISORY SOMETIME THIS EVENING...AND PERSIST THROUGH SUNDAY
MORNING. BY LATE SUNDAY MORNING...HIGH PRESSURE WILL MOVE SLOWLY
EAST INTO THE REGION...WITH WINDS DECREASING FROM WEST TO EAST
DURING THE AFTERNOON. SKIES WILL BE MOSTLY SUNNY WITH SEASONABLY
COLD TEMPERATURES...HIGHS IN THE UPPER 20S TO MID 30S AT MOST
LOCATIONS. A COLD SUNDAY NIGHT CAN BE EXPECTED AS HIGH PRESSURE
SETTLES OVER THE NORTHERN PLAINS. LOWS WILL GENERALLY BE IN THE 5
TO 15 DEGREE RANGE.
AS HIGH MOVES EAST OF THE AREA ON MONDAY...WINDS WILL BECOME
SOUTHERLY ACROSS THE AREA...ALLOWING WARMER AIR TO MOVE IN. HIGHS
WILL RANGE FROM THE 40S OVER NORTHEASTERN WY AND THE BLACK HILLS
AREA...TO THE MID 30S OVER CENTRAL SD. MILDER AIR WILL PUSH EAST
ACROSS THE REST OF THE AREA MONDAY NIGHT...WITH LOWS ONLY IN THE
20S AND LOWER 30S.
EXTENDED...AN UPPER LEVEL RIDGE WILL DOMINATE THE WEATHER TUESDAY
THROUGH THURSDAY...LEADING TO SIGNIFICANTLY WARMER THAN AVERAGE
TEMPERATURES. THE RIDGE WILL BREAK DOWN ON FRIDAY LEADING TO COOLER
TEMPERATURES AND SMALL CHANCES FOR PRECIPITATION OVER PARTS OF
NORTHEASTERN WYOMING AND THE BLACK HILLS...ALTHOUGH MODEL SOLUTIONS
CONTINUE TO DIVERGE FOR FRIDAY THROUGH THE WEEKEND LEADING TO LOW
FORECAST CONFIDENCE FOR THOSE PERIODS.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY UNTIL NOON MST /1 PM CST/ SUNDAY FOR BENNETT-BUTTE-
CUSTER CO PLAINS-HAAKON-HARDING-HERMOSA FOOT HILLS-JACKSON-
MELLETTE-NORTHERN FOOT HILLS-NORTHERN MEADE CO PLAINS-
PENNINGTON CO PLAINS-PERKINS-RAPID CITY-SOUTHERN MEADE CO
PLAINS-STURGIS/PIEDMONT FOOT HILLS-TODD-TRIPP-ZIEBACH.
WY...NONE.
&&
$$
SHORT TERM...07
LONG TERM....WFO UNR
AVIATION...07
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
540 PM CST SAT DEC 31 2011
.DISCUSSION.../ISSUED AT 335 PM CST/
LATEST RUC...NAM AND HRRR CONTINUE TO BE IN FAIRLY CLOSE AGREEMENT
WITH PRECIPITATION DEVELOPING LATE THIS AFTERNOON AND EVENING...
ESPECIALLY ALONG AND EAST OF INTERSTATE 29 ALONG AXIS OF STRONG H85
FRONTOGENESIS...WITH VERY LITTLE PRECIPITATION TO THE WEST. CURRENT
RADAR STARTING TO SHOW PRECIPITATION DEVELOPING OVER SOUTHEAST SOUTH
DAKOTA AHEAD OF SHORT WAVE AND WOULD EXPECT PRECIPITATION TO BECOME
MORE WIDESPREAD. COLD FRONT ALREADY MOVING EAST OF I29 AND SHOULD
MOVE THROUGH NORTHWEST IOWA AND SOUTHWEST MINNESOTA BY 01Z. LOOKS
LIKE DYNAMIC COOLING OF THE LAYER SHOULD NOT BE A PROBLEM AND RAIN
SHOULD CHANGE OVER TO SNOW FAIRLY QUICKLY AS UPPER WAVE APPROACHES.
LIKE TO SEE A QUICK 2 TO 4 INCH SNOW OVER FAR EASTERN CWA WITH AN 1
TO 2 INCHES BETWEEN I29 AND THE HEAVIEST SNOW. ADD THE STRONG WINDS
WITH THE SNOW AND WILL SEE SOME PRETTY BACK CONDITIONS FROM 00Z TO
06Z AND WILL KEEP WARNING GOING ACROSS THE FAR EAST WITH WINTER
WEATHER ADVISORY CONTINUING JUST TO THE WEST. EVEN THROUGH SNOWFALL
WILL NOT REACH WINTER STORMS CRITERIA...THE COMBINATION OF WIND AND
SNOW...PLUS THE HOLIDAY EVE MAKES IT REASONABLE TO ISSUE SINCE THERE
WILL BE PLENTY PEOPLE TRAVELING. SNOW SHOULD QUICKLY END AFTER 05Z
OR 06Z AS SYSTEM PULLS AWAY. WILL ALSO KEEP THE WIND ADVISORIES
GOING THROUGH SUNDAY WITH WIND GUST TO 35 TO 45 MPH TONIGHT AS
SYSTEM GETS WOUND UP.
WITH THESE CONTINUED STRONG WINDS SUNDAY WILL COME SOME LOW CLOUDS
IN THE COOLER AIR...MAINLY TO THE NORTHEAST HALF OF THE FORECAST
AREA. WHILE A FEW FLURRIES ARE NOT OUT OF THE QUESTION...HAVE
ELECTED TO GO WITHOUT FOR NOW. UPPER SYSTEM WILL BE PULLING EAST
STEADILY AND THE LOW CLOUD DECK IS EXPECTED TO GET PRETTY THIN.
ANOTHER THOUGHT IS WILL THERE BE ANY LINGERING BLOWING SNOW IN THE
FAR EAST AND HAVE LEFT THAT OUT AS WELL WITH MARGINAL ACCUMULATIONS
AND AT LEAST 6 HOURS WITHOUT ANY FALLING SNOW BEFORE THE START OF
THE DAY.
CLEARING LOOKS STRONG FOR SUNDAY NIGHT. KEEPING WIND ADVISORY IS
MARGINAL BUT AS EVENING WINDS SHOW A VERY SMALL DECREASE ON MODELS
WILL KEEP AS IS FOR SOME MN AND IA COUNTIES THROUGH MIDNIGHT.
COLDER...BUT YES STILL A LITTLE ABOVE NORMAL...TEMPERATURES SUNDAY
WILL COOL MODESTLY SUNDAY NIGHT WITH THE SLOW WIND DECREASE. MONDAY
SHOULD THEN BE FAIRLY SUNNY WITH SOME INCREASING HIGH THIN CLOUDS
AND A TAD COOLER THAN SUNDAY ON HIGHS...BUT OF COURSE WITH MUCH
LIGHTER WINDS AS SURFACE RIDGE MOVES OVER AREA. WARMING STARTS
MONDAY NIGHT AND CONTINUES THROUGH PASSAGE OF WEAK TUESDAY SHORT
WAVE WHICH WILL BRING ONLY SOME ASSOCIATED CLOUD COVER AND NO
PRECIPITATION. WARMING WITH FAIRLY CLEAR SKIES WILL CONTINUE
WEDNESDAY AND PEAK THURSDAY WITH A POTENTIAL FOR RECORD HIGH
TEMPERATURES THURSDAY...AT LEAST HERE AT FSD WHERE WE HAVE OUR
CURRENTLY LATEST SUB 50 DAILY RECORD HIGH FOR THAT DATE. FRIDAY AND
SATURDAY LOOKS LIKE COOLING AND PROBABLY UNEVENTFUL...WITH LITTLE OR
NO PRECIPITATION AND WINDS BEHIND FRIDAY COLD FRONT FOR NOW
PROJECTED TO BE LESS THAN CURRENT SYSTEM. / WILLIAMS
&&
.AVIATION.../FOR THE 00Z TAF ISSUANCE/
BAND OF HEAVIEST SNOW WILL MOVE ACROSS PARTS OF SOUTHWEST MINNESOTA
AND NORTHWEST IOWA THIS EVENING...PRODUCING OCCASIONAL IFR-LOCALLY
LIFR CEILINGS/VISIBILITIES IN -SN. LINGERING PRECIPITATION FARTHER
WEST IS EXPECTED TO END AT I-29 TAF LOCATIONS BETWEEN 00Z-03Z...WITH
MVFR CEILINGS OVER CENTRAL AND EASTERN PARTS OF THE AREA GRADUALLY
IMPROVING TO VFR FROM WEST TO EAST THROUGH 07Z. STRONG NORTHWEST
WINDS WILL SPREAD ACROSS THE REGION TONIGHT/SUNDAY. FREQUENT GUSTS
OF 25-35KT LIKELY OVERNIGHT THROUGH 15Z SUNDAY...WITH THE STRONGEST
WINDS EXPECTED SOUTH OF INTERSTATE 90 THROUGH THE MISSOURI VALLEY.
AFTER 15Z SUNDAY...COOLING ALOFT WILL ALLOW FOR STRONGER GUSTS OF
35-40KTS...WITH THESE STRONG WINDS PERSISTING THROUGH 02/00Z. /JH
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...WIND ADVISORY UNTIL 6 PM CST SUNDAY FOR IAZ001-012-020-031.
WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO MIDNIGHT
CSTTONIGHT FOR IAZ002-013-021-032.
WIND ADVISORY FROM 3 PM THIS AFTERNOON TO MIDNIGHT CST SUNDAY
NIGHT FOR IAZ002-013-021-032.
WINTER STORM WARNING FROM 6 PM THIS EVENING TO MIDNIGHT CST
TONIGHT FOR IAZ003-014-022.
WIND ADVISORY FROM MIDNIGHT TONIGHT TO MIDNIGHT CST SUNDAY
NIGHT FOR IAZ003-014-022.
MN...WIND ADVISORY UNTIL 6 PM CST SUNDAY FOR MNZ098.
WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO MIDNIGHT
CST TONIGHT FOR MNZ071-072-080-089.
WIND ADVISORY FROM 3 PM THIS AFTERNOON TO MIDNIGHT CST SUNDAY
NIGHT FOR MNZ071-072-080-089-097.
WINTER STORM WARNING FROM 6 PM THIS EVENING TO MIDNIGHT CST
TONIGHT FOR MNZ081-090.
WIND ADVISORY FROM MIDNIGHT TONIGHT TO MIDNIGHT CST SUNDAY
NIGHT FOR MNZ081-090.
NE...WIND ADVISORY UNTIL 6 PM CST SUNDAY FOR NEZ013-014.
SD...WIND ADVISORY UNTIL 6 PM CST SUNDAY FOR SDZ038>040-052>056-
058>062-064>071.
WIND ADVISORY UNTIL 6 PM CST SUNDAY FOR SDZ050-057-063.
&&
$$
AREA FORECAST DISCUSSION
NWS MIDLAND/ODESSA TX
1142 PM CST SAT DEC 31 2011
.DISCUSSION...
SEE AVIATION DISCUSSION BELOW
&&
.AVIATION...
A COLD FRONT WILL CONTINUE TO RESULT IN BREEZY NORTH NORTHEAST WINDS
AT MOST TERMINALS LATE THIS EVENING. THE STRONGEST GUSTS...NEAR 30
KT...WILL ONLY PERSIST ANOTHER HOUR OR SO AT MAF. THE FRONT WILL
PASS OVER FST AROUND 07Z. THE WINDS WILL BEGIN TO SUBSIDE THROUGH
THE EARLY MORNING HOURS AND BECOME MORE EASTERLY AFTER SUNRISE.
CLEAR SKIES ARE ANTICIPATED.
&&
.PREV DISCUSSION... /ISSUED 818 PM CST SAT DEC 31 2011/
UPDATE...
A MINOR UPDATE HAS BEEN SENT TO INCREASE WINDS SLIGHTLY WITH FROPA.
DISCUSSION...
THE COLD FRONT IS NOW ENTERING THE NORTHERN PERMIAN BASIN AND
NORTHERN LEA COUNTY THIS EVENING...WITH SIGNIFICANT 3 HR PRESSURE
FALLS (~11 MB) STILL BEING OBSERVED OVER THE EASTERN PANHANDLE.
ESTIMATES FROM RADAR INDICATE THE FRONT IS MOVING AROUND 40 MPH.
THIS SHOULD RESULT IN FROPA FOR MAF AROUND 03-04Z. ALTHOUGH
PRESSURE RISES WILL LIKELY DECREASE A BIT AS THE FRONT SLIDES
SOUTH...THE RUC13 STILL SUGGESTS A TIGHT PRESSURE GRADIENT WILL BE
DRAPED ACROSS THE PERMIAN BASIN AROUND 06Z. A STRONG NORTHERLY LLJ
WILL ALSO BE PRESENT OVER THE LATTER REGION. WE HAVE INCREASED
WINDS SLIGHTLY FROM SE NM THROUGH THE PERMIAN BASIN...AND THE
WESTERN LOW ROLLING PLAINS. GUSTS MAY BRIEFLY EXCEED 40 MPH BEHIND
THE FRONT ACROSS THE PERMIAN BASIN AND WESTERN LOW ROLLING PLAINS
FROM 04-07Z. ALL UPDATED PRODUCTS HAVE BEEN SENT.
&&
.MAF WATCHES/WARNINGS/ADVISORIES...
NM...NONE.
TX...NONE.
&&
$$
76
AREA FORECAST DISCUSSION...UPDATED
NWS MIDLAND/ODESSA TX
818 PM CST SAT DEC 31 2011
.UPDATE...
A MINOR UPDATE HAS BEEN SENT TO INCREASE WINDS SLIGHTLY WITH FROPA.
&&
.DISCUSSION...
THE COLD FRONT IS NOW ENTERING THE NORTHERN PERMIAN BASIN AND
NORTHERN LEA COUNTY THIS EVENING...WITH SIGNIFICANT 3 HR PRESSURE
FALLS (~11 MB) STILL BEING OBSERVED OVER THE EASTERN PANHANDLE.
ESTIMATES FROM RADAR INDICATE THE FRONT IS MOVING AROUND 40 MPH.
THIS SHOULD RESULT IN FROPA FOR MAF AROUND 03-04Z. ALTHOUGH
PRESSURE RISES WILL LIKELY DECREASE A BIT AS THE FRONT SLIDES
SOUTH...THE RUC13 STILL SUGGESTS A TIGHT PRESSURE GRADIENT WILL BE
DRAPED ACROSS THE PERMIAN BASIN AROUND 06Z. A STRONG NORTHERLY LLJ
WILL ALSO BE PRESENT OVER THE LATTER REGION. WE HAVE INCREASED
WINDS SLIGHTLY FROM SE NM THROUGH THE PERMIAN BASIN...AND THE
WESTERN LOW ROLLING PLAINS. GUSTS MAY BRIEFLY EXCEED 40 MPH BEHIND
THE FRONT ACROSS THE PERMIAN BASIN AND WESTERN LOW ROLLING PLAINS
FROM 04-07Z. ALL UPDATED PRODUCTS HAVE BEEN SENT.
&&
.PRELIMINARY POINT TEMPS/POPS...
BIG SPRING TX 31 53 27 51 / 0 0 0 0
CARLSBAD NM 28 50 23 51 / 0 0 0 0
DRYDEN TX 38 58 30 56 / 0 0 0 0
FORT STOCKTON TX 31 53 29 53 / 0 0 0 0
GUADALUPE PASS TX 29 41 29 52 / 0 0 0 0
HOBBS NM 26 47 23 49 / 0 0 0 0
MARFA TX 26 50 17 52 / 0 0 0 0
MIDLAND INTL AIRPORT TX 27 51 24 51 / 0 0 0 0
ODESSA TX 30 51 26 51 / 0 0 0 0
WINK TX 28 53 23 53 / 0 0 0 0
&&
.MAF WATCHES/WARNINGS/ADVISORIES...
NM...NONE.
TX...NONE.
&&
$$
78/49
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1134 PM CST SAT DEC 31 2011
.SHORT TERM...TONIGHT THROUGH TUESDAY
315 PM CST SAT DEC 31 2011
MAIN FORECAST CONCERNS ARE HIGH WIND POTENTIAL TONIGHT THROUGH
SUNDAY NIGHT AND WINTER WEATHER CONCERNS ON TOP OF THESE WINDS.
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS
SHOWED RIDGING BUILDING UP ALONG THE WEST COAST OF THE U.S. INTO
BRITISH COLUMBIA...A SPLIT TROUGH OVER THE CENTRAL PORTION OF NORTH
AMERICA...AND RIDGING OVER THE WESTERN GREAT LAKES AND OHIO VALLEY
REGIONS. WITHIN THE SPLIT TROUGH...A VERY POTENT SHORTWAVE WAS NEAR
GOODLAND KANSAS...AN UPPER LOW OVER SOUTHERN MANITOBA...AND A
SHORTWAVE ON ITS BACK SIDE IN SOUTHERN ALBERTA. MUCH FOCUS IN ON
THAT POTENT SHORTWAVE FOR THIS FORECAST. AT 12Z...WHEN IT WAS BACK
NEAR RIVERTON WYOMING...THE SOUNDING SHOWED A DROP IN THE TROPOPAUSE
OF 200MB AND A 500MB TEMP THAT COOLED 13C FROM THE PREVIOUS 00Z
SOUNDING. MODELS HAVE STRUGGLED WITH THIS SHORTWAVE WITH ALL OF THEM
NEEDING TO SHIFT MORE SOUTH AND DEEPER...ESPECIALLY THE NAM IN WHICH
ITS 30.12Z RUN FORECASTED THE SHORTWAVE TO BE IN EASTERN SOUTH
DAKOTA AT THIS TIME. AHEAD OF THE POTENT SHORTWAVE...A 995MB LOW WAS
LOCATED OVER SOUTHEAST NEBRASKA. SOUTH WINDS OF 35 TO 50 KT WERE
OCCURRING AT 925MB PER PROFILER DATA AHEAD OF THIS SURFACE
LOW...ADVECTING WARMER AIR INTO THE FORECAST AREA. TEMPERATURES HAVE
CLIMBED INTO THE 30S AND 40S...WARMEST IN NORTHEAST IOWA. ON THE
BACK SIDE OF THE SURFACE LOW ACROSS WESTERN PORTIONS OF NEBRASKA...
KANSAS AND ADJACENT STATES...SURFACE WINDS HAVE BEEN BLOWING HARD.
PEAK GUSTS OF 40-50 KT AND EVEN A FEW UP AROUND 60 KT HAVE BEEN
REPORTED. ALSO ON THE BACK SIDE OF THE LOW...PRECIPITATION HAS BEEN
FORMING OVER NEBRASKA IN THE DEFORMATION AXIS.
TONIGHT...FOCUS AGAIN IS MOSTLY ON THE POTENT SHORTWAVE. GOOD
MODEL AGREEMENT EXISTS THAT THIS SHORTWAVE LIFTS RAPIDLY NORTHEAST
INTO SOUTHERN LAKE MICHIGAN BY 12Z SUNDAY. THIS TRACK PLACES THE
BEST 500MB HEIGHT FALLS TO OUR SOUTH...HOWEVER...PLENTY OF DPVA
STILL OCCURS NORTH OF IT OVER THE FORECAST AREA. NEXT CONCERN IS THE
DEFORMATION PRECIPITATION DEVELOPING OVER NEBRASKA. VERY GOOD
AGREEMENT EXISTS THAT THIS PRECIPITATION WILL FORM INTO A
SOUTHWEST-NORTHEAST BAND FROM WESTERN IOWA INTO NORTHWEST WISCONSIN
THIS EVENING. IN FACT...THE BAND SHOULD INTENSIFY AS AN UPPER JET
STREAK DEVELOPS OVER NORTHERN MINNESOTA...PLACING THE BAND IN THE
FAVORABLE RIGHT ENTRANCE REGION. AS THIS JET CORE LIFTS INTO
NORTHERN ONTARIO LATE IN THE EVENING THROUGH THE OVERNIGHT...THE
DEFORMATION BAND OF PRECIPITATION LOOKS TO WEAKEN AS IT PUSHES EAST
INTO THE FORECAST AREA. MEANWHILE...A NEW DEFORMATION BAND AIDED BY
THE STRONGER 500MB HEIGHT FALLS IS FORECAST TO FORM FROM EASTERN
IOWA INTO NORTHEAST WISCONSIN AFTER MIDNIGHT. BOTH BANDS CERTAINLY
GIVE A GOOD OPPORTUNITY FOR PRECIPITATION...SO PRECIPITATION CHANCES
ARE AT 100. HOWEVER...HAVE HAD TO DELAY SOME OF THE PRECIPITATION
THIS EVENING BECAUSE OF THE FARTHER SOUTH TRACK WITH THE
SHORTWAVE/SURFACE LOW. SNOWFALL AMOUNTS ARE TRICKY TOO. WITH A
SLOWER MOVEMENT DUE TO THE SHORTWAVE BEING MORE AMPLIFIED...THE
PRECIPITATION MAY END UP AS RAIN OR RAIN/SNOW MIX FOR A COUPLE
HOURS. ONCE THE COLD AIR COMES IN...THERE MAY BE AN HOUR OF SOME
HEAVIER SNOW...BUT THEN THE DEFORMATION BANDS PUSH EAST. COMBINE
THAT WITH THE FACT THAT SNOW TO WATER RATIOS MAY ONLY END UP 10-15
TO 1...KEPT DOWN TOO AS A RESULT OF STRONGER WINDS DEVELOPING
BREAKING THE SNOW CRYSTALS APART. HAVE REDUCED SNOWFALL AMOUNTS SOME
TONIGHT...WITH NOW ONLY LESS THAN AN INCH SOUTH OF I-90 TO 1-2
INCHES ALONG AND NORTH OF THERE. NEXT CONCERN IS THE WINDS. AS THE
SURFACE LOW ASSOCIATED WITH THE SHORTWAVE LIFTS INTO SOUTHEAST
WISCONSIN AFTER MIDNIGHT...WINDS SHOULD KICK UP DRAMATICALLY IN ITS
WAKE. A TIGHT PRESSURE GRADIENT...COLD AIR ADVECTION FOR MIXING...
SUBSIDENCE AND RAPID PRESSURE RISES ARE ALL PRESENT...WHICH SHOULD
ALLOW WINDS TO CRANK UP. WITH A 50-60KT CORE OF WINDS FORECAST
BETWEEN 900-850MB...MUCH OF THIS SHOULD MIX DOWN. GREATEST POTENTIAL
TO SEE HIGH WIND WARNING IS OVER NORTHEAST IOWA WHERE ISALLOBARIC
FORCING IS MAXIMIZED. HAVE ISSUED THE WARNING IN THIS AREA. THE
COMBINATION OF THE WINDS AND SNOW WILL RESULT IN SOME BLOWING
SNOW...BUT THE EXTENT IS UNCERTAIN DUE TO AMOUNT OF SNOWFALL AND A
WARMER GROUND FROM THE EVENING HOURS. BECAUSE OF THIS...DID NOT
UPGRADE ANY WINTER WEATHER ADVISORIES TO WARNINGS.
SUNDAY INTO SUNDAY NIGHT...POTENT SHORTWAVE IS PROGGED TO LIFT
QUICKLY AWAY FROM THE AREA...WHILE THE SHORTWAVE OVER ALBERTA IS
FORECAST TO SLIDE ACROSS WESTERN PORTIONS OF THE FORECAST AREA
DURING THE DAY SUNDAY. INTERESTING FACT WITH THIS NEXT SHORTWAVE IS
THAT THE TROPOPAUSE DROPS TO 600MB OR SO. WITH THIS SHORTWAVE COMING
THROUGH...ALONG WITH THE SURFACE PRESSURE GRADIENT REMAINING TIGHT
AND DURING PEAK HEATING...FELT IT WAS PRUDENT TO KEEP THE HIGH WIND
WARNING GOING RIGHT THROUGH SUNDAY. ELSEWHERE...WIND ADVISORIES ARE
STILL APPROPRIATE...AND KEPT THE WINTER WEATHER ADVISORY GOING FOR
EASTERN PORTIONS OF THE FORECAST AREA UNTIL 15Z TO HANDLE ANY
LINGERING DEFORMATION PRECIPITATION AS WELL AS BLOWING SNOW. BLOWING
SNOW IS POSSIBLE ELSEWHERE...ESPECIALLY IN THE MORNING BEFORE SNOW
PROBABLY BECOMES COMPACTED ENOUGH TO NOT RESTRICT VISIBILITIES AS
MUCH. DID ALSO MAINTAIN 20-30 PERCENT CHANCES THROUGHOUT THE DAY
SUNDAY FOR ISOLATED-SCATTERED SNOW SHOWERS...PRODUCED BY WEAK LIFT
INDICATED IN THE LEFT-OVER STRATUS DECK BEHIND THE SYSTEM. DECIDED
TOO TO HAVE A MENTION OF FLURRIES SUNDAY NIGHT WITH THE STRATUS DECK
STILL AROUND...AS WELL AS NEUTRAL TO VERY WEAK LIFT IN THE CLOUDS.
NOTE THAT MUCH OF SUNDAY NIGHT SHOULD END UP IN SUBSIDENCE WITH THE
GENERAL UPPER TROUGH HEADING EAST. WITH COLD ADVECTION OCCURRING
THROUGHOUT SUNDAY AND SUNDAY NIGHT...TEMPERATURES LOOK TO PRETTY
MUCH HOLD STEADY OR SLIGHTLY FALL ON SUNDAY...FOLLOWED BY DROPPING
INTO THE TEENS AND POSSIBLY SINGLE DIGITS FOR NORTH CENTRAL
WISCONSIN. WINDS LOOK TO DIMINISH BELOW ADVISORY CRITERIA AROUND THE
CURRENT END TIME IN THE FORECAST...06Z MONDAY...THOUGH IT IS
POSSIBLE IT MAY NEED EXTENSION TO 12Z. WILL LET LATER SHIFTS TACKLE
THIS MORE.
MONDAY INTO MONDAY NIGHT...500MB HEIGHTS ARE FORECAST TO RISE QUITE
A BIT DURING THIS TIME PERIOD...IN RESPONSE TO UPPER RIDGING BEING
PUSHED EASTWARD INTO THE PLAINS. SUBSIDENCE ASSOCIATED WITH THE
BUILDING HEIGHTS SHOULD RESULT IN A DRY FORECAST WITH GRADUAL
CLEARING OF CLOUDS. WINDS LOOK TO ALSO GRADUAL DIMINISH...LIKELY
GOING TO CALM MONDAY NIGHT WHEN THE SURFACE RIDGE MOVES THROUGH.
DESPITE THE CLEARING OF CLOUDS...ANTICIPATING TEMPERATURES TO STILL
STRUGGLE TO RISE MUCH...GIVEN 850MB TEMPS FORECAST BETWEEN -14 TO
-18C MUCH OF THE DAY. GENERALLY FOLLOWED A BLEND OF GUIDANCE FOR
HIGHS. COULD SEE SOME BELOW ZERO TEMPERATURES MONDAY NIGHT...
ESPECIALLY IN THE TYPICAL COLD SPOTS OF WISCONSIN WITH SNOW LIKELY
ON THE GROUND...COMBINED WITH THE CLEARING SKIES AND DIMINISHING
WIND. IF THINGS SPEED UP A LITTLE MORE THAN WHAT IS FORECAST...A
RISING TEMPERATURE TREND MAY NEED TO BE INCLUDED OVER WESTERN
PORTIONS OF THE FORECAST AREA MONDAY NIGHT.
TUESDAY...THE FEATURE MODELS HAVE PUSHING THE UPPER RIDGE EASTWARD
INTO THE PLAINS IS A SHORTWAVE TROUGH...FORECAST OVER FAR EASTERN
MONTANA AT 12Z TUESDAY. THIS TROUGH WILL HEAD EAST INTO MINNESOTA BY
00Z WEDNESDAY...INITIATING A WARM ADVECTION PATTERN OVER THE
FORECAST AREA. AS A RESULT OF THIS WARM ADVECTION...LIKELY TO SEE
DEVELOPMENT/TRANSLATION OF MID AND HIGH CLOUDS INTO THE FORECAST
AREA. RAISED SKY COVER SOME...BUT MORE INCREASES MAY BE NECESSARY.
PRECIPITATION IS NOT EXPECTED DUE TO DRIER LOW LEVEL AIR AND MUCH OF
THE DPVA/THERMODYNAMIC FORCING PROGGED NORTHWEST OF THE FORECAST
AREA. CERTAINLY SOMETHING TO WATCH. 850MB TEMPS DO CLIMB UP TO -4 TO
-8C BY 00Z...SO HIGH TEMPERATURES SHOULD GET BACK UP INTO THE 20S
FOR MOST LOCATIONS.
.LONG TERM...TUESDAY NIGHT THROUGH SATURDAY
315 PM CST SAT DEC 31 2011
31.12 MODELS SHOWING A SHORTWAVE TROUGH MOVING ACROSS NORTHERN
MINNESOTA AND INTO CENTRAL WISCONSIN TUESDAY NIGHT. THIS TROUGH HAS
BEEN A FAIRLY CONSISTENT SIGNAL IN THE MODELS SO HAVE DECIDED TO
EXPAND PRECIPITATION CHANCES FURTHER SOUTH...MAINLY TO ALONG THE
I-94 CORRIDOR. TEMPERATURES WILL BE COLD ENOUGH TO ALLOW THE
PRECIPITATION TO FALL AS SNOW. LOOK FOR LOW TEMPERATURES TO RANGE
FROM THE MID TEENS ACROSS NORTH CENTRAL WISCONSIN TO AROUND 20
ACROSS NORTHEAST IOWA. A BROAD UPPER RIDGE IS EXPECTED TO SLIDE FROM
THE NORTHERN PLAINS AND INTO THE UPPER MISSISSIPPI RIVER VALLEY
WEDNESDAY INTO THURSDAY...WITH A GRADUAL WARMING TREND EXPECTED
ACROSS THE FORECAST AREA. 850 MB TEMPERATURES WILL START OUT AROUND
NEGATIVE 2 C EARLY WEDNESDAY AFTERNOON...WARMING TO AROUND PLUS 10 C
BY THURSDAY AFTERNOON. HAVE NUDGED TEMPERATURES TOWARDS THE ECMWF
WHICH SEEMS TO BE HANDLING TEMPERATURES BETTER OVERALL. QUIET
WEATHER IS ANTICIPATED WEDNESDAY THROUGH THURSDAY WITH HIGH PRESSURE
IN CONTROL. LOOK FOR HIGH TEMPERATURES MAINLY IN THE 30S ON
WEDNESDAY...WARMING INTO THE 40S BY THURSDAY. FRIDAY COULD BE EVEN
WARMER WITH TEMPS CLIMBING INTO THE UPPER 40S IN SOME LOCATIONS.
HAVE INCREASED HIGH A COUPLE OF DEGREES ON FRIDAY...BUT IF TRENDS
CONTINUE THEY WILL HAVE TO BE INCREASED FURTHER. THE RIDGE WILL PUSH
EAST THROUGH THE DAY ON FRIDAY AS A COLD FRONT SWINGS SOUTH FROM
CANADA AND THROUGH THE UPPER MIDWEST. THE OVERALL UPPER PATTERN
LOOKS TO TRANSITION TO A NORTHWEST FLOW SCENARIO IN THE WAKE OF THE
FRONT WITH A BROAD UPPER TROUGH SETTING UP ACROSS THE REGION. A
SHORTWAVE TROUGH IS EXPECTED TO MOVE ACROSS THE REGION ON SATURDAY
BRINGING A CHANCE OF LIGHT SNOW TO THE AREA.
&&
.AVIATION...THROUGH 06Z MONDAY
1134 PM CST SAT DEC 31 2011
STRONG LOW PRESSURE MOVING INTO EASTERN IOWA...WITH COLD FRONT
EXTENDING NORTHWARD INTO WESTERN WISCONSIN. WINDS HAVE ALREADY
COME AROUND TO THE NORTHWEST AT BOTH KLSE AND KRST. A BAND OF
PRECIPITATION WILL PASS ACROSS THE TAF SITES THROUGH THE OVERNIGHT
HOURS...WITH MAINLY SNOW AT KRST AND RAIN CHANGING TO SNOW AT
KLSE. THE PRESSURE GRADIENT TIGHTENS IN THE WAKE OF THE LOW AND
BUFKIT SOUNDINGS SHOW POTENTIAL FOR SUSTAINED NORTHWEST WINDS OF
25 TOP 30 KNOTS WITH GUSTS TO 45 KNOTS. THESE WINDS COMBINED WITH
THE FALLING SNOW WILL RESULT IN BLOWING SNOW AND A PERIOD OF
VISIBILITIES IN THE IFR CATEGORY THROUGH 14Z SUNDAY. GRADIENT DOES
REMAIN TIGHT THROUGH 06Z MONDAY SO EXPECT WINDS TO REMAIN GUSTING
TO NEAR 40 TO 45 KNOTS THROUGH THE PERIOD. IFR/LIFR CEILINGS WILL
BE COMMON THROUGH 14Z..WITH MVFR CEILINGS THEN AFTER THAT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
315 PM CST SAT DEC 31 2011
WI...WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 6 AM CST SUNDAY
FOR WIZ041-053>055-061.
WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 6 AM CST
SUNDAY FOR WIZ032-033.
WIND ADVISORY FROM 6 AM SUNDAY TO MIDNIGHT CST SUNDAY NIGHT FOR
WIZ032-033-041-053>055-061.
WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM CST SUNDAY
FOR WIZ042>044.
WIND ADVISORY FROM 9 AM SUNDAY TO MIDNIGHT CST SUNDAY NIGHT FOR
WIZ017-029-034-042>044.
WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 9 AM CST
SUNDAY FOR WIZ017-029-034.
MN...WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 6 AM CST SUNDAY
FOR MNZ096.
WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 6 AM CST
SUNDAY FOR MNZ079-086>088-094-095.
WIND ADVISORY FROM 6 AM SUNDAY TO MIDNIGHT CST SUNDAY NIGHT FOR
MNZ079-086>088-094>096.
IA...HIGH WIND WARNING FROM MIDNIGHT TONIGHT TO MIDNIGHT CST SUNDAY
NIGHT FOR IAZ008-018-019-029-030.
WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 6 AM CST SUNDAY
FOR IAZ010-011-019-029-030.
WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 6 AM CST
SUNDAY FOR IAZ008-009-018.
WIND ADVISORY FROM 6 AM SUNDAY TO MIDNIGHT CST SUNDAY NIGHT FOR
IAZ009>011.
&&
$$
SHORT TERM...AJ
LONG TERM...WETENKAMP
AVIATION...RABERDING
AREA FORECAST DISCUSSION...UPDATED
NWS GREEN BAY WI
1037 PM CST SAT DEC 31 2011
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.UPDATE...IMPRESSIVE SYSTEM WITH STG DYNAMICS BEARING DOWN ON THE
AREA. BUT MOISTURE SOMEWHAT LIMITED...AND ADDING COMPLICATIONS TO
THE FCST.
PERHAPS STARTING TO GET A BETTER IDEA OF HOW SYSTEM WL EVOLVE
TNGT. BAND OF PCPN IN ZONE OF STG FRONTOGENETIC FORCING HAS BEEN
INCRG FM SWRN MN TO FAR NW WI. SEVERAL LTG STRIKES WITHIN THIS
BAND DURING THE PAST HR OR SO. THE BAND WL PROBABLY BE DIRECTED
INTO THE NW PART OF THE FCST AREA LATER TNGT...WHERE IT WL SLOWLY
WEAKEN LATE TNGT AND EARLY SUN.
MEANWHILE..EXPECT ANOTHER BAND OF PCPN TO DEVELOP A LITTLE LATER
TNGT FARTHER SE IN ASSOC WITH THE MAIN SHRTWV ITSELF. MIGHT BE
SEEING THE START OF THAT NOW WITH BLOB OF PCPN DEVELOPING BTWN OMA
AND DSM. THAT WL PROBABLY EXPAND INTO THE SE PART OF THE FCST AREA
LATE TNGT...AND THEN LINGER AND POSSIBLY PIVOT ACRS THE ERN PART
OF THE FCST AREA SUN MORNING. IT/S STARTING TO LOOK LIKE WE MAY
GET A RELATIVE MIN IN THE PCPN IN THE AREA BTWN THE 2 MAIN BANDS.
CURRENT FCST SEEMS TO HAVE A DECENT HANDLE ON THE OVERALL
SCENARIO. MAIN CHGS WITH THE UPCOMING UPDATE WL BE TO TWEAK PCPN
TIMING A BIT IN THE GRIDS...AND TO MOVE THE QPF/SNOWAMT GRIDS
TOWARD SCENARIO DESCRIBED ABOVE.
WON/T BE MAKING ANY CHGS TO HEADLINE TYPES. ONLY CHG WL BE TO
START CALUMET/BROWN COUNTY WW.Y AT 09Z SINCE CURRENT 12Z START
LOOKS A LITTLE LATE. NPW FOR THE WI.Y ALREADY OUT. REST OF UPDATED
PRODUCE SUITE WL BE OUT ASAP.
SKOWRONSKI
&&
.PREV DISCUSSION...ISSUED AT 640 PM CST SAT DEC 31 2011...
UPDATE...IMPRESSIVE SYSTEM CONTS TO EVOLVE IN THE PLAINS TNGT.
INTENSE VORT APPEARS TO HAVE FINALLY FINISHED DIGGING. IT/S MOVG
EWD ACRS N-C KS RIGHT NOW. IT SEEMS DESTINED TO SWING ARND INTO A
NEGATIVE TILT AS IT EJECTS OUT TOWARD LAKE MICHIGAN LATE TNGT AND
EARLY SUN. TREND ON GUID SEEMS TO BE TO SHIFT BETTER FORCING MORE
TOWARD E-C WI...WITH COMMA HEAD STRUCTURE POSSIBLY EVOLVING AND
PIVOTING ACRS THAT AREA VERY LATE TNGT AND EARLY SUN. THAT
CERTAINLY FITS WITH THE SRN POSN OF THE VORT RIGHT NOW...BUT WOULD
LIKE TO FOLLOW EVOLUTION OF SYSTEM A LITTLE MORE AND GET A PEEK AT
THE 00Z GUIDANCE PKG BEFORE TOTALLY COMMITTING TO THAT CHG IN THE
FCST. AS THINGS STAND RIGHT NOW...WL PROBABLY BE ADJUSTING FCST
TO HAVE A LITTLE MORE SN IN ERN WI AND A LITTLE LESS IN C/NC WI
/OTHER THAN THE SNOWBELT AREAS/.
DON/T ANTICIPATE ANY CHG TO HEADLINE TYPES...THOUGH WL NEED TO
TAKE A LOOK AT START TIMES WITH EVENING UPDATE. TARGET IS TO HAVE
UPDATED PRODUCT SUITE OUT BTWN 900 PM AND 930 PM.
SKOWRONSKI
DISCUSSION ISSUED AT 226 PM CST SAT DEC 31 2011...
SHORT TERM...TONIGHT THROUGH NEW YEARS DAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A DEVELOPING
LOW PRESSURE SYSTEM MOVING EAST OVER SOUTHEAST NEBRASKA THIS
AFTERNOON...JUST AHEAD OF A VIGOROUS SHORTWAVE. WEAK SHORTWAVE
IMPULSE TRAVELING NORTHEAST OVER MINNESOTA HAS GENERATED A BAND OF
SLEET/FREEZING RAIN OVER NORTHERN WISCONSIN WHICH HAS BEEN REACHING
THE GROUND...BUT IS NOT ACCUMULATING...ACCORDING TO A SPOTTER AT
LAKE TOMAHAWK. OTHERWISE...MID AND HIGH CLOUDS CONTINUE TO PASS
OVER THE STATE...AND LOW CLOUDS CONTINUE TO BE A NUISANCE OVER
CENTRAL AND NORTHEAST WISCONSIN...JUST NORTH OF A SURFACE WARM
FRONT. AHEAD OF THE LOW...PLENTY OF CLEAR SKIES AND DRY AIR EXISTS
OVER KANSAS...MISSOURI...AND SOUTHERN ILLINOIS WHERE DEWPOINTS ARE
IN THE 20S AND 30S. BUT FARTHER NW...AN FGEN BAND IS DEVELOPING
OVER NE NEBRASKA AND SE SOUTH DAKOTA...WHICH WILL BE THE FEATURE TO
WATCH HEADING INTO TONIGHT. ALSO...BEEFY WINDS OF 45-60 KTS ARE
IMPACTING THE FRONT RANGE OF THE ROCKIES. AS THE SURFACE LOW TRACKS
NE...HEADLINES FOR BOTH SNOW AND WIND ARE THE MAIN FORECAST CONCERNS.
TONIGHT...BEEFY SHORTWAVE OVER THE PLAINS WILL BECOME NEGATIVELY
TILTED AS IT DRIVES A SURFACE LOW TO THE NORTHEAST TO CENTRAL OR
SOUTHERN LAKE MICHIGAN. MODELS DIDNT INITIALIZE ALL THAT WELL THIS
MORNING (TOO WEAK WITH THE SHORTWAVE...AND THERMAL PROBLEMS)...SO
ITS TOUGH TO HAVE CONFIDENCE IN ANY ONE PARTICULAR MODEL. TRIED TO
BLEND THE NAM AND GFS...BUT CONFIDENCE IS NO BETTER THAN AVERAGE
WITH THE DETAILS. ALTHOUGH WILL HAVE SE WINDS AT THE
SURFACE...WINDS TURN TO THE SW ALOFT AND DRAW IN WARMER AIR FROM THE
CENTRAL PLAINS. HOWEVER...THE AIR FROM THE PLAINS IS ALSO QUITE DRY
AS DEPICTED BY THE 12Z RAOBS (PWATS LESS THAN 0.4 INCHES INTO
NORTHERN TEXAS AND LOUISIANA)...AND PRECIP MAY BE SLOW TO MOVE INTO
THE REGION DESPITE INCREASING FORCING. AS A RESULT...HAVE DELAYED
PRECIP UNTIL AFTER MIDNIGHT. AS THE LOW MOVES OVER SOUTHEAST
WISCONSIN TONIGHT...A TIGHTENING THERMAL GRADIENT ON THE NW FLANK OF
THE LOW WILL LEAD TO AN FGEN CIRCULATION MOVING FROM SW TO NE ACROSS
THE STATE. PTYPE IS LIKELY TO START OUT AS ALL SNOW OVER N-C
WISCONSIN...WHERE EVAPORATION INTO A DRY LAYER ALOFT YIELDS WET BULB
TEMPERATURES BELOW ZERO. NOT AS CLEAR CUT OVER CENTRAL WISCONSIN
WHERE WET BULB TEMPERATURES APPROACH 0C AT MIDNIGHT SO LEFT A
RAIN/SNOW MIX THERE. ENOUGH WARM AIR LOOKS TO SURGE INTO THE FOX
VALLEY AND LAKESHORE WHERE PTYPE COULD START OUT AS ALL
RAIN...BEFORE TRANSITIONING TO A MIX OR ALL SNOW BY 12Z. BECAUSE
OF THE MIX...SNOW ACCUMS LOOK TO BE QUITE A BIT HIGHER OVER CENTRAL
AND NORTH-CENTRAL WISCONSIN...ON THE ORDER OF 1 TO 3
INCHES...COMPARED TO LESS THAN AN INCH OVER THE FOX VALLEY AND LAKE
SHORE. WINDS WILL ALSO BE BEGINNING TO STRENGTHEN LATE
TONIGHT...BUT THE REAL PUSH WONT BE UNTIL SUNDAY MORNING.
NEW YEARS DAY...LOW PRESSURE WILL CONTINUE TO STRENGTHEN AS IT LIFTS
OVER NORTHERN LOWER MICHIGAN AND LAKE HURON ON SUNDAY. ONGOING
PRECIP WILL HAVE CHANGED TO ALL SNOW EXCEPT OVER DOOR COUNTY EARLY
SUNDAY MORNING. ARCTIC AIR WILL BE ROTATING AROUND THE LOW...WHICH
WILL STEEPEN LOW LEVEL LAPSE RATES...AND ALLOW MIXING OF 900MB WINDS
OF 40 TO 50 KTS. BECAUSE OF THE WINDS AND SNOWFALL...SUNDAY MORNING
LOOKS TO HAVE THE MOST IMPACT FROM THE STORM...AS THERE COULD BE A
2-3 HR PERIOD OF FAIRLY NASTY CONDITIONS. THE SNOW WILL BE WINDING
DOWN OVER CENTRAL AND NORTHEAST WISCONSIN POST 15Z WITH TOTAL
ACCUMULATIONS OF 2-4 INCHES AND 1-3 INCHES RESPECTIVELY.
HOWEVER...NW WINDS AND GROWING INSTABILITY OVER WESTERN LAKE
SUPERIOR WILL SET UP GOOD CONDITIONS FOR LAKE EFFECT SNOW. SOME
QUESTIONS ON THE EXACT WIND DIRECTION...AS 1000-850MB WINDS BACK
AROUND TO THE 320-330 DEGREE DIRECTION LATE SUNDAY MORNING AND INTO
THE AFTERNOON. AS A RESULT...BEST CONDITIONS FOR BEEFY SNOW
ACCUMULATIONS MAY HAVE TO WAIT UNTIL SUNDAY NIGHT WITHIN THE SNOW
BELT. WILL STILL KEEP 2-4 INCHES IN THE FORECAST THOUGH. ONCE THE
SNOW DIMINISHES OUTSIDE THE SNOW BELT...WIND GUSTS WILL REMAIN AN
ISSUE FOR THE REST OF THE DAY. GUSTS WILL LIKELY FALL IN THE 40-50
MPH RANGE...AND THE HIGHEST GUSTS SHOULD FALL OVER CENTRAL AND
NORTHEAST WISCONSIN. HAVE POSTPONED THE START OF THE WIND ADVISORY
UNTIL 18Z EVERYWHERE...FIGURING THE MORNING SNOW WILL HAVE POTENTIAL
TO BLOW AROUND THROUGH AT LEAST MIDDAY. WILL SEE MORNING HIGHS IN
THE MID 20S TO LOWER 30S FALL THROUGH THE DAY.
AS FOR HEADLINES...ALREADY MENTIONED THE WIND ADVISORY. HAVE
DELAYED THE WINTER HEADLINES UNTIL 06Z TONIGHT FOR NORTH-CENTRAL
WISCONSIN AND UNTIL 09Z FOR NORTHEAST WISCONSIN (EXCEPT FOR THE DOOR
WHICH STARTS AT 12Z). STUCK WITH THE WINTER WEATHER ADVISORY
BECAUSE FIGURING SNOW AMOUNTS WILL BE IN THE 2-4 INCH RANGE AT THE
HIGHEST END...AND THE SNOW WILL BE WINDING DOWN AS THE WINDS CRANK
UP SUNDAY MORNING. THERE MAY BE A SHORT WINDOW OF A COUPLE HOURS OF
LOW VSBYS (SAY A HALF MILE OR LESS)...BUT FELT THE MARGIN OF ERROR
IS TOO HIGH FOR AN UPGRADE TO A WINTER STORM WARNING. COMBINED WITH
UNCERTAINTY IN MODEL PERFORMANCE...HAVE STUCK WITH A WINTER WEATHER
ADVISORY FOR NOW.
LONG TERM...SUNDAY NIGHT THROUGH NEXT SATURDAY.
CYCLONIC UPPER FLOW WILL PRODUCE LAKE EFFECT SNOW IN FAR
NORTHCENTRAL WISCONSIN AND SNOW SHOWERS OR FLURRIES SUNDAY NIGHT
THROUGH MONDAY. MONDAY SHOULD BE THE COLDEST DAY OF THE WINTER SO
FAR WITH HIGHS IN THE HIGH SINGLE NUMBERS AND TEENS ALONG WITH A
GUSTY WIND PRODUCING WIND CHILLS BELOW ZERO. 850 MB TEMPERATURES
FORECAST TO FALL TO NEAR -20C LATE SUNDAY NIGHT AND MONDAY MORNING
CREATING IMPRESSIVE INSTABILITY OVER LAKE SUPERIOR. WIND DIRECTIONS
ARE NOT IDEAL (A LITTLE TOO MUCH WESTERLY COMPONENT) FOR VILAS
COUNTY AND THE WIND SPEEDS ARE ACTUALLY STRONGER THAN IDEAL (WINDS
MORE THAN 40 KNOTS DOES NOT PERMIT DRY AIR TO PICK UP MUCH
MOISTURE IF IT TRAVEL SO FAST ACROSS THE LAKE). SO THINK THAT WE
WILL SEE ANOTHER 3 TO 5 INCHES ACROSS VILAS COUNTY FOR THE SUNDAY
EVENING THROUGH MONDAY NOON WITH LOCALLY HIGHER AMOUNTS NEAR THE
MICHIGAN BORDER.
UPPER RIDGING BEGINS TO ARRIVE MONDAY EVENING WHICH WILL CAUSE
WINDS TO BACK SUFFICIENTLY TO DIMINISH THE LAKE EFFECT SNOW TO
JUST FLURRIES. A CLIPPER SYSTEM WILL BRING INCREASING CLOUDS
TUESDAY AND MAYBE SOME SNOW SHOWERS TUESDAY NIGHT. NO MUCH
EXPECTED DUE TO VERY DRY AIR IN PLACE BEFORE IT/S ARRIVAL. THEN
MORE UPPER RIDGING FOR WEDNESDAY NIGHT THROUGH FRIDAY WITH MAINLY
DRY AND MILD WEATHER. A BIG DIFFERENCE IN THE MODELS FOR NEXT
SATURDAY OVER THE WESTERN GREAT LAKES SO MADE NO CHANGES TO
PREVIOUS FORECAST FOR THAT PERIOD.
MARINE...SOUTH WINDS AHEAD OF AN APPROACHING ARCTIC FRONT COULD
CAUSE HAZARDOUS CONDITIONS FOR SMALL CRAFTS THIS AFTERNOON AND
TONIGHT. AS THE ARCTIC COLD FRONT SWEEPS EAST OF THE AREA LATE
TONIGHT....WEST TO NORTHWEST GALES WILL DEVELOP SUNDAY MORNING
WHICH WILL CONTINUE INTO MONDAY AFTERNOON. THERE IS AN OUTSIDE
CHANCE THAT GUSTS COULD APPROACH OR REACH STORM FORCE OVER
NORTHERN DOOR COUNTY SUNDAY NIGHT.
&&
.AVIATION...FOR 06Z TAF ISSUANCE. PCPN WORKING IN A LITTLE MORE
QUICKLY THAN EARLIER EXPECTED.
SKOWRONSKI
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 3 AM TO NOON CST SUNDAY FOR WIZ013-
020-021-031-037>039-045-048-049-073-074.
WIND ADVISORY FROM NOON SUNDAY TO MIDNIGHT CST SUNDAY NIGHT FOR
WIZ010>013-018>021-030-031-035>040-045-048>050-073-074.
WINTER WEATHER ADVISORY FROM 6 AM TO NOON CST SUNDAY FOR WIZ022-
040-050.
WINTER WEATHER ADVISORY UNTIL NOON CST SUNDAY FOR WIZ010>012-018-
019-030-035-036.
WIND ADVISORY FROM NOON SUNDAY TO 6 PM CST MONDAY FOR WIZ022.
WINTER STORM WARNING UNTIL 3 PM CST MONDAY FOR WIZ005.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS GREEN BAY WI
908 PM CST SAT DEC 31 2011
.UPDATE...IMPRESSIVE SYSTEM WITH STG DYNAMICS BEARING DOWN ON THE
AREA. BUT MOISTURE SOMEWHAT LIMITED...AND ADDING COMPLICATIONS TO
THE FCST.
PERHAPS STARTING TO GET A BETTER IDEA OF HOW SYSTEM WL EVOLVE
TNGT. BAND OF PCPN IN ZONE OF STG FRONTOGENETIC FORCING HAS BEEN
INCRG FM SWRN MN TO FAR NW WI. SEVERAL LTG STRIKES WITHIN THIS
BAND DURING THE PAST HR OR SO. THE BAND WL PROBABLY BE DIRECTED
INTO THE NW PART OF THE FCST AREA LATER TNGT...WHERE IT WL SLOWLY
WEAKEN LATE TNGT AND EARLY SUN.
MEANWHILE..EXPECT ANOTHER BAND OF PCPN TO DEVELOP A LITTLE LATER
TNGT FARTHER SE IN ASSOC WITH THE MAIN SHRTWV ITSELF. MIGHT BE
SEEING THE START OF THAT NOW WITH BLOB OF PCPN DEVELOPING BTWN OMA
AND DSM. THAT WL PROBABLY EXPAND INTO THE SE PART OF THE FCST AREA
LATE TNGT...AND THEN LINGER AND POSSIBLY PIVOT ACRS THE ERN PART
OF THE FCST AREA SUN MORNING. IT/S STARTING TO LOOK LIKE WE MAY
GET A RELATIVE MIN IN THE PCPN IN THE AREA BTWN THE 2 MAIN BANDS.
CURRENT FCST SEEMS TO HAVE A DECENT HANDLE ON THE OVERALL
SCENARIO. MAIN CHGS WITH THE UPCOMING UPDATE WL BE TO TWEAK PCPN
TIMING A BIT IN THE GRIDS...AND TO MOVE THE QPF/SNOWAMT GRIDS
TOWARD SCENARIO DESCRIBED ABOVE.
WON/T BE MAKING ANY CHGS TO HEADLINE TYPES. ONLY CHG WL BE TO
START CALUMET/BROWN COUNTY WW.Y AT 09Z SINCE CURRENT 12Z START
LOOKS A LITTLE LATE. NPW FOR THE WI.Y ALREADY OUT. REST OF UPDATED
PRODUCE SUITE WL BE OUT ASAP.
SKOWRONSKI
&&
.PREV DISCUSSION...ISSUED AT 640 PM CST SAT DEC 31 2011...
UPDATE...IMPRESSIVE SYSTEM CONTS TO EVOLVE IN THE PLAINS TNGT.
INTENSE VORT APPEARS TO HAVE FINALLY FINISHED DIGGING. IT/S MOVG
EWD ACRS N-C KS RIGHT NOW. IT SEEMS DESTINED TO SWING ARND INTO A
NEGATIVE TILT AS IT EJECTS OUT TOWARD LAKE MICHIGAN LATE TNGT AND
EARLY SUN. TREND ON GUID SEEMS TO BE TO SHIFT BETTER FORCING MORE
TOWARD E-C WI...WITH COMMA HEAD STRUCTURE POSSIBLY EVOLVING AND
PIVOTING ACRS THAT AREA VERY LATE TNGT AND EARLY SUN. THAT
CERTAINLY FITS WITH THE SRN POSN OF THE VORT RIGHT NOW...BUT WOULD
LIKE TO FOLLOW EVOLUTION OF SYSTEM A LITTLE MORE AND GET A PEEK AT
THE 00Z GUIDANCE PKG BEFORE TOTALLY COMMITTING TO THAT CHG IN THE
FCST. AS THINGS STAND RIGHT NOW...WL PROBABLY BE ADJUSTING FCST
TO HAVE A LITTLE MORE SN IN ERN WI AND A LITTLE LESS IN C/NC WI
/OTHER THAN THE SNOWBELT AREAS/.
DON/T ANTICIPATE ANY CHG TO HEADLINE TYPES...THOUGH WL NEED TO
TAKE A LOOK AT START TIMES WITH EVENING UPDATE. TARGET IS TO HAVE
UPDATED PRODUCT SUITE OUT BTWN 900 PM AND 930 PM.
SKOWRONSKI
DISCUSSION ISSUED AT 226 PM CST SAT DEC 31 2011...
SHORT TERM...TONIGHT THROUGH NEW YEARS DAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A DEVELOPING
LOW PRESSURE SYSTEM MOVING EAST OVER SOUTHEAST NEBRASKA THIS
AFTERNOON...JUST AHEAD OF A VIGOROUS SHORTWAVE. WEAK SHORTWAVE
IMPULSE TRAVELING NORTHEAST OVER MINNESOTA HAS GENERATED A BAND OF
SLEET/FREEZING RAIN OVER NORTHERN WISCONSIN WHICH HAS BEEN REACHING
THE GROUND...BUT IS NOT ACCUMULATING...ACCORDING TO A SPOTTER AT
LAKE TOMAHAWK. OTHERWISE...MID AND HIGH CLOUDS CONTINUE TO PASS
OVER THE STATE...AND LOW CLOUDS CONTINUE TO BE A NUISANCE OVER
CENTRAL AND NORTHEAST WISCONSIN...JUST NORTH OF A SURFACE WARM
FRONT. AHEAD OF THE LOW...PLENTY OF CLEAR SKIES AND DRY AIR EXISTS
OVER KANSAS...MISSOURI...AND SOUTHERN ILLINOIS WHERE DEWPOINTS ARE
IN THE 20S AND 30S. BUT FARTHER NW...AN FGEN BAND IS DEVELOPING
OVER NE NEBRASKA AND SE SOUTH DAKOTA...WHICH WILL BE THE FEATURE TO
WATCH HEADING INTO TONIGHT. ALSO...BEEFY WINDS OF 45-60 KTS ARE
IMPACTING THE FRONT RANGE OF THE ROCKIES. AS THE SURFACE LOW TRACKS
NE...HEADLINES FOR BOTH SNOW AND WIND ARE THE MAIN FORECAST CONCERNS.
TONIGHT...BEEFY SHORTWAVE OVER THE PLAINS WILL BECOME NEGATIVELY
TILTED AS IT DRIVES A SURFACE LOW TO THE NORTHEAST TO CENTRAL OR
SOUTHERN LAKE MICHIGAN. MODELS DIDNT INITIALIZE ALL THAT WELL THIS
MORNING (TOO WEAK WITH THE SHORTWAVE...AND THERMAL PROBLEMS)...SO
ITS TOUGH TO HAVE CONFIDENCE IN ANY ONE PARTICULAR MODEL. TRIED TO
BLEND THE NAM AND GFS...BUT CONFIDENCE IS NO BETTER THAN AVERAGE
WITH THE DETAILS. ALTHOUGH WILL HAVE SE WINDS AT THE
SURFACE...WINDS TURN TO THE SW ALOFT AND DRAW IN WARMER AIR FROM THE
CENTRAL PLAINS. HOWEVER...THE AIR FROM THE PLAINS IS ALSO QUITE DRY
AS DEPICTED BY THE 12Z RAOBS (PWATS LESS THAN 0.4 INCHES INTO
NORTHERN TEXAS AND LOUISIANA)...AND PRECIP MAY BE SLOW TO MOVE INTO
THE REGION DESPITE INCREASING FORCING. AS A RESULT...HAVE DELAYED
PRECIP UNTIL AFTER MIDNIGHT. AS THE LOW MOVES OVER SOUTHEAST
WISCONSIN TONIGHT...A TIGHTENING THERMAL GRADIENT ON THE NW FLANK OF
THE LOW WILL LEAD TO AN FGEN CIRCULATION MOVING FROM SW TO NE ACROSS
THE STATE. PTYPE IS LIKELY TO START OUT AS ALL SNOW OVER N-C
WISCONSIN...WHERE EVAPORATION INTO A DRY LAYER ALOFT YIELDS WET BULB
TEMPERATURES BELOW ZERO. NOT AS CLEAR CUT OVER CENTRAL WISCONSIN
WHERE WET BULB TEMPERATURES APPROACH 0C AT MIDNIGHT SO LEFT A
RAIN/SNOW MIX THERE. ENOUGH WARM AIR LOOKS TO SURGE INTO THE FOX
VALLEY AND LAKESHORE WHERE PTYPE COULD START OUT AS ALL
RAIN...BEFORE TRANSITIONING TO A MIX OR ALL SNOW BY 12Z. BECAUSE
OF THE MIX...SNOW ACCUMS LOOK TO BE QUITE A BIT HIGHER OVER CENTRAL
AND NORTH-CENTRAL WISCONSIN...ON THE ORDER OF 1 TO 3
INCHES...COMPARED TO LESS THAN AN INCH OVER THE FOX VALLEY AND LAKE
SHORE. WINDS WILL ALSO BE BEGINNING TO STRENGTHEN LATE
TONIGHT...BUT THE REAL PUSH WONT BE UNTIL SUNDAY MORNING.
NEW YEARS DAY...LOW PRESSURE WILL CONTINUE TO STRENGTHEN AS IT LIFTS
OVER NORTHERN LOWER MICHIGAN AND LAKE HURON ON SUNDAY. ONGOING
PRECIP WILL HAVE CHANGED TO ALL SNOW EXCEPT OVER DOOR COUNTY EARLY
SUNDAY MORNING. ARCTIC AIR WILL BE ROTATING AROUND THE LOW...WHICH
WILL STEEPEN LOW LEVEL LAPSE RATES...AND ALLOW MIXING OF 900MB WINDS
OF 40 TO 50 KTS. BECAUSE OF THE WINDS AND SNOWFALL...SUNDAY MORNING
LOOKS TO HAVE THE MOST IMPACT FROM THE STORM...AS THERE COULD BE A
2-3 HR PERIOD OF FAIRLY NASTY CONDITIONS. THE SNOW WILL BE WINDING
DOWN OVER CENTRAL AND NORTHEAST WISCONSIN POST 15Z WITH TOTAL
ACCUMULATIONS OF 2-4 INCHES AND 1-3 INCHES RESPECTIVELY.
HOWEVER...NW WINDS AND GROWING INSTABILITY OVER WESTERN LAKE
SUPERIOR WILL SET UP GOOD CONDITIONS FOR LAKE EFFECT SNOW. SOME
QUESTIONS ON THE EXACT WIND DIRECTION...AS 1000-850MB WINDS BACK
AROUND TO THE 320-330 DEGREE DIRECTION LATE SUNDAY MORNING AND INTO
THE AFTERNOON. AS A RESULT...BEST CONDITIONS FOR BEEFY SNOW
ACCUMULATIONS MAY HAVE TO WAIT UNTIL SUNDAY NIGHT WITHIN THE SNOW
BELT. WILL STILL KEEP 2-4 INCHES IN THE FORECAST THOUGH. ONCE THE
SNOW DIMINISHES OUTSIDE THE SNOW BELT...WIND GUSTS WILL REMAIN AN
ISSUE FOR THE REST OF THE DAY. GUSTS WILL LIKELY FALL IN THE 40-50
MPH RANGE...AND THE HIGHEST GUSTS SHOULD FALL OVER CENTRAL AND
NORTHEAST WISCONSIN. HAVE POSTPONED THE START OF THE WIND ADVISORY
UNTIL 18Z EVERYWHERE...FIGURING THE MORNING SNOW WILL HAVE POTENTIAL
TO BLOW AROUND THROUGH AT LEAST MIDDAY. WILL SEE MORNING HIGHS IN
THE MID 20S TO LOWER 30S FALL THROUGH THE DAY.
AS FOR HEADLINES...ALREADY MENTIONED THE WIND ADVISORY. HAVE
DELAYED THE WINTER HEADLINES UNTIL 06Z TONIGHT FOR NORTH-CENTRAL
WISCONSIN AND UNTIL 09Z FOR NORTHEAST WISCONSIN (EXCEPT FOR THE DOOR
WHICH STARTS AT 12Z). STUCK WITH THE WINTER WEATHER ADVISORY
BECAUSE FIGURING SNOW AMOUNTS WILL BE IN THE 2-4 INCH RANGE AT THE
HIGHEST END...AND THE SNOW WILL BE WINDING DOWN AS THE WINDS CRANK
UP SUNDAY MORNING. THERE MAY BE A SHORT WINDOW OF A COUPLE HOURS OF
LOW VSBYS (SAY A HALF MILE OR LESS)...BUT FELT THE MARGIN OF ERROR
IS TOO HIGH FOR AN UPGRADE TO A WINTER STORM WARNING. COMBINED WITH
UNCERTAINTY IN MODEL PERFORMANCE...HAVE STUCK WITH A WINTER WEATHER
ADVISORY FOR NOW.
LONG TERM...SUNDAY NIGHT THROUGH NEXT SATURDAY.
CYCLONIC UPPER FLOW WILL PRODUCE LAKE EFFECT SNOW IN FAR
NORTHCENTRAL WISCONSIN AND SNOW SHOWERS OR FLURRIES SUNDAY NIGHT
THROUGH MONDAY. MONDAY SHOULD BE THE COLDEST DAY OF THE WINTER SO
FAR WITH HIGHS IN THE HIGH SINGLE NUMBERS AND TEENS ALONG WITH A
GUSTY WIND PRODUCING WIND CHILLS BELOW ZERO. 850 MB TEMPERATURES
FORECAST TO FALL TO NEAR -20C LATE SUNDAY NIGHT AND MONDAY MORNING
CREATING IMPRESSIVE INSTABILITY OVER LAKE SUPERIOR. WIND DIRECTIONS
ARE NOT IDEAL (A LITTLE TOO MUCH WESTERLY COMPONENT) FOR VILAS
COUNTY AND THE WIND SPEEDS ARE ACTUALLY STRONGER THAN IDEAL (WINDS
MORE THAN 40 KNOTS DOES NOT PERMIT DRY AIR TO PICK UP MUCH
MOISTURE IF IT TRAVEL SO FAST ACROSS THE LAKE). SO THINK THAT WE
WILL SEE ANOTHER 3 TO 5 INCHES ACROSS VILAS COUNTY FOR THE SUNDAY
EVENING THROUGH MONDAY NOON WITH LOCALLY HIGHER AMOUNTS NEAR THE
MICHIGAN BORDER.
UPPER RIDGING BEGINS TO ARRIVE MONDAY EVENING WHICH WILL CAUSE
WINDS TO BACK SUFFICIENTLY TO DIMINISH THE LAKE EFFECT SNOW TO
JUST FLURRIES. A CLIPPER SYSTEM WILL BRING INCREASING CLOUDS
TUESDAY AND MAYBE SOME SNOW SHOWERS TUESDAY NIGHT. NO MUCH
EXPECTED DUE TO VERY DRY AIR IN PLACE BEFORE IT/S ARRIVAL. THEN
MORE UPPER RIDGING FOR WEDNESDAY NIGHT THROUGH FRIDAY WITH MAINLY
DRY AND MILD WEATHER. A BIG DIFFERENCE IN THE MODELS FOR NEXT
SATURDAY OVER THE WESTERN GREAT LAKES SO MADE NO CHANGES TO
PREVIOUS FORECAST FOR THAT PERIOD.
MARINE...SOUTH WINDS AHEAD OF AN APPROACHING ARCTIC FRONT COULD
CAUSE HAZARDOUS CONDITIONS FOR SMALL CRAFTS THIS AFTERNOON AND
TONIGHT. AS THE ARCTIC COLD FRONT SWEEPS EAST OF THE AREA LATE
TONIGHT....WEST TO NORTHWEST GALES WILL DEVELOP SUNDAY MORNING
WHICH WILL CONTINUE INTO MONDAY AFTERNOON. THERE IS AN OUTSIDE
CHANCE THAT GUSTS COULD APPROACH OR REACH STORM FORCE OVER
NORTHERN DOOR COUNTY SUNDAY NIGHT.
&&
.AVIATION...FOR 00Z TAF ISSUANCE. MAIN CHGS WAS TO SHIFT AXIS OF
BEST SNOWS MORE TOWARD E-C WI.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 3 AM TO NOON CST SUNDAY FOR WIZ013-
020-021-031-037>039-045-048-049-073-074.
WIND ADVISORY FROM NOON SUNDAY TO MIDNIGHT CST SUNDAY NIGHT FOR
WIZ010>013-018>021-030-031-035>040-045-048>050-073-074.
WINTER WEATHER ADVISORY FROM 6 AM TO NOON CST SUNDAY FOR WIZ022-
040-050.
WINTER WEATHER ADVISORY UNTIL NOON CST SUNDAY FOR WIZ010>012-018-
019-030-035-036.
WIND ADVISORY FROM NOON SUNDAY TO 6 PM CST MONDAY FOR WIZ022.
WINTER STORM WARNING UNTIL 3 PM CST MONDAY FOR WIZ005.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS GREEN BAY WI
640 PM CST SAT DEC 31 2011
.UPDATE...IMPRESSIVE SYSTEM CONTS TO EVOLVE IN THE PLAINS TNGT.
INTENSE VORT APPEARS TO HAVE FINALLY FINISHED DIGGING. IT/S MOVG
EWD ACRS N-C KS RIGHT NOW. IT SEEMS DESTINED TO SWING ARND INTO A
NEGATIVE TILT AS IT EJECTS OUT TOWARD LAKE MICHIGAN LATE TNGT AND
EARLY SUN. TREND ON GUID SEEMS TO BE TO SHIFT BETTER FORCING MORE
TOWARD E-C WI...WITH COMMA HEAD STRUCTURE POSSIBLY EVOLVING AND
PIVOTING ACRS THAT AREA VERY LATE TNGT AND EARLY SUN. THAT
CERTAINLY FITS WITH THE SRN POSN OF THE VORT RIGHT NOW...BUT WOULD
LIKE TO FOLLOW EVOLUTION OF SYSTEM A LITTLE MORE AND GET A PEEK AT
THE 00Z GUIDANCE PKG BEFORE TOTALLY COMMITTING TO THAT CHG IN THE
FCST. AS THINGS STAND RIGHT NOW...WL PROBABLY BE ADJUSTING FCST
TO HAVE A LITTLE MORE SN IN ERN WI AND A LITTLE LESS IN C/NC WI
/OTHER THAN THE SNOWBELT AREAS/.
DON/T ANTICIPATE ANY CHG TO HEADLINE TYPES...THOUGH WL NEED TO
TAKE A LOOK AT START TIMES WITH EVENING UPDATE. TARGET IS TO HAVE
UPDATED PRODUCT SUITE OUT BTWN 900 PM AND 930 PM.
SKOWRONSKI
&&
.PREV DISCUSSION...ISSUED AT 226 PM CST SAT DEC 31 2011...
SHORT TERM...TONIGHT THROUGH NEW YEARS DAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A DEVELOPING
LOW PRESSURE SYSTEM MOVING EAST OVER SOUTHEAST NEBRASKA THIS
AFTERNOON...JUST AHEAD OF A VIGOROUS SHORTWAVE. WEAK SHORTWAVE
IMPULSE TRAVELING NORTHEAST OVER MINNESOTA HAS GENERATED A BAND OF
SLEET/FREEZING RAIN OVER NORTHERN WISCONSIN WHICH HAS BEEN REACHING
THE GROUND...BUT IS NOT ACCUMULATING...ACCORDING TO A SPOTTER AT
LAKE TOMAHAWK. OTHERWISE...MID AND HIGH CLOUDS CONTINUE TO PASS
OVER THE STATE...AND LOW CLOUDS CONTINUE TO BE A NUISANCE OVER
CENTRAL AND NORTHEAST WISCONSIN...JUST NORTH OF A SURFACE WARM
FRONT. AHEAD OF THE LOW...PLENTY OF CLEAR SKIES AND DRY AIR EXISTS
OVER KANSAS...MISSOURI...AND SOUTHERN ILLINOIS WHERE DEWPOINTS ARE
IN THE 20S AND 30S. BUT FARTHER NW...AN FGEN BAND IS DEVELOPING
OVER NE NEBRASKA AND SE SOUTH DAKOTA...WHICH WILL BE THE FEATURE TO
WATCH HEADING INTO TONIGHT. ALSO...BEEFY WINDS OF 45-60 KTS ARE
IMPACTING THE FRONT RANGE OF THE ROCKIES. AS THE SURFACE LOW TRACKS
NE...HEADLINES FOR BOTH SNOW AND WIND ARE THE MAIN FORECAST CONCERNS.
TONIGHT...BEEFY SHORTWAVE OVER THE PLAINS WILL BECOME NEGATIVELY
TILTED AS IT DRIVES A SURFACE LOW TO THE NORTHEAST TO CENTRAL OR
SOUTHERN LAKE MICHIGAN. MODELS DIDNT INITIALIZE ALL THAT WELL THIS
MORNING (TOO WEAK WITH THE SHORTWAVE...AND THERMAL PROBLEMS)...SO
ITS TOUGH TO HAVE CONFIDENCE IN ANY ONE PARTICULAR MODEL. TRIED TO
BLEND THE NAM AND GFS...BUT CONFIDENCE IS NO BETTER THAN AVERAGE
WITH THE DETAILS. ALTHOUGH WILL HAVE SE WINDS AT THE
SURFACE...WINDS TURN TO THE SW ALOFT AND DRAW IN WARMER AIR FROM THE
CENTRAL PLAINS. HOWEVER...THE AIR FROM THE PLAINS IS ALSO QUITE DRY
AS DEPICTED BY THE 12Z RAOBS (PWATS LESS THAN 0.4 INCHES INTO
NORTHERN TEXAS AND LOUISIANA)...AND PRECIP MAY BE SLOW TO MOVE INTO
THE REGION DESPITE INCREASING FORCING. AS A RESULT...HAVE DELAYED
PRECIP UNTIL AFTER MIDNIGHT. AS THE LOW MOVES OVER SOUTHEAST
WISCONSIN TONIGHT...A TIGHTENING THERMAL GRADIENT ON THE NW FLANK OF
THE LOW WILL LEAD TO AN FGEN CIRCULATION MOVING FROM SW TO NE ACROSS
THE STATE. PTYPE IS LIKELY TO START OUT AS ALL SNOW OVER N-C
WISCONSIN...WHERE EVAPORATION INTO A DRY LAYER ALOFT YIELDS WET BULB
TEMPERATURES BELOW ZERO. NOT AS CLEAR CUT OVER CENTRAL WISCONSIN
WHERE WET BULB TEMPERATURES APPROACH 0C AT MIDNIGHT SO LEFT A
RAIN/SNOW MIX THERE. ENOUGH WARM AIR LOOKS TO SURGE INTO THE FOX
VALLEY AND LAKESHORE WHERE PTYPE COULD START OUT AS ALL
RAIN...BEFORE TRANSITIONING TO A MIX OR ALL SNOW BY 12Z. BECAUSE
OF THE MIX...SNOW ACCUMS LOOK TO BE QUITE A BIT HIGHER OVER CENTRAL
AND NORTH-CENTRAL WISCONSIN...ON THE ORDER OF 1 TO 3
INCHES...COMPARED TO LESS THAN AN INCH OVER THE FOX VALLEY AND LAKE
SHORE. WINDS WILL ALSO BE BEGINNING TO STRENGTHEN LATE
TONIGHT...BUT THE REAL PUSH WONT BE UNTIL SUNDAY MORNING.
NEW YEARS DAY...LOW PRESSURE WILL CONTINUE TO STRENGTHEN AS IT LIFTS
OVER NORTHERN LOWER MICHIGAN AND LAKE HURON ON SUNDAY. ONGOING
PRECIP WILL HAVE CHANGED TO ALL SNOW EXCEPT OVER DOOR COUNTY EARLY
SUNDAY MORNING. ARCTIC AIR WILL BE ROTATING AROUND THE LOW...WHICH
WILL STEEPEN LOW LEVEL LAPSE RATES...AND ALLOW MIXING OF 900MB WINDS
OF 40 TO 50 KTS. BECAUSE OF THE WINDS AND SNOWFALL...SUNDAY MORNING
LOOKS TO HAVE THE MOST IMPACT FROM THE STORM...AS THERE COULD BE A
2-3 HR PERIOD OF FAIRLY NASTY CONDITIONS. THE SNOW WILL BE WINDING
DOWN OVER CENTRAL AND NORTHEAST WISCONSIN POST 15Z WITH TOTAL
ACCUMULATIONS OF 2-4 INCHES AND 1-3 INCHES RESPECTIVELY.
HOWEVER...NW WINDS AND GROWING INSTABILITY OVER WESTERN LAKE
SUPERIOR WILL SET UP GOOD CONDITIONS FOR LAKE EFFECT SNOW. SOME
QUESTIONS ON THE EXACT WIND DIRECTION...AS 1000-850MB WINDS BACK
AROUND TO THE 320-330 DEGREE DIRECTION LATE SUNDAY MORNING AND INTO
THE AFTERNOON. AS A RESULT...BEST CONDITIONS FOR BEEFY SNOW
ACCUMULATIONS MAY HAVE TO WAIT UNTIL SUNDAY NIGHT WITHIN THE SNOW
BELT. WILL STILL KEEP 2-4 INCHES IN THE FORECAST THOUGH. ONCE THE
SNOW DIMINISHES OUTSIDE THE SNOW BELT...WIND GUSTS WILL REMAIN AN
ISSUE FOR THE REST OF THE DAY. GUSTS WILL LIKELY FALL IN THE 40-50
MPH RANGE...AND THE HIGHEST GUSTS SHOULD FALL OVER CENTRAL AND
NORTHEAST WISCONSIN. HAVE POSTPONED THE START OF THE WIND ADVISORY
UNTIL 18Z EVERYWHERE...FIGURING THE MORNING SNOW WILL HAVE POTENTIAL
TO BLOW AROUND THROUGH AT LEAST MIDDAY. WILL SEE MORNING HIGHS IN
THE MID 20S TO LOWER 30S FALL THROUGH THE DAY.
AS FOR HEADLINES...ALREADY MENTIONED THE WIND ADVISORY. HAVE
DELAYED THE WINTER HEADLINES UNTIL 06Z TONIGHT FOR NORTH-CENTRAL
WISCONSIN AND UNTIL 09Z FOR NORTHEAST WISCONSIN (EXCEPT FOR THE DOOR
WHICH STARTS AT 12Z). STUCK WITH THE WINTER WEATHER ADVISORY
BECAUSE FIGURING SNOW AMOUNTS WILL BE IN THE 2-4 INCH RANGE AT THE
HIGHEST END...AND THE SNOW WILL BE WINDING DOWN AS THE WINDS CRANK
UP SUNDAY MORNING. THERE MAY BE A SHORT WINDOW OF A COUPLE HOURS OF
LOW VSBYS (SAY A HALF MILE OR LESS)...BUT FELT THE MARGIN OF ERROR
IS TOO HIGH FOR AN UPGRADE TO A WINTER STORM WARNING. COMBINED WITH
UNCERTAINTY IN MODEL PERFORMANCE...HAVE STUCK WITH A WINTER WEATHER
ADVISORY FOR NOW.
LONG TERM...SUNDAY NIGHT THROUGH NEXT SATURDAY.
CYCLONIC UPPER FLOW WILL PRODUCE LAKE EFFECT SNOW IN FAR
NORTHCENTRAL WISCONSIN AND SNOW SHOWERS OR FLURRIES SUNDAY NIGHT
THROUGH MONDAY. MONDAY SHOULD BE THE COLDEST DAY OF THE WINTER SO
FAR WITH HIGHS IN THE HIGH SINGLE NUMBERS AND TEENS ALONG WITH A
GUSTY WIND PRODUCING WIND CHILLS BELOW ZERO. 850 MB TEMPERATURES
FORECAST TO FALL TO NEAR -20C LATE SUNDAY NIGHT AND MONDAY MORNING
CREATING IMPRESSIVE INSTABILITY OVER LAKE SUPERIOR. WIND DIRECTIONS
ARE NOT IDEAL (A LITTLE TOO MUCH WESTERLY COMPONENT) FOR VILAS
COUNTY AND THE WIND SPEEDS ARE ACTUALLY STRONGER THAN IDEAL (WINDS
MORE THAN 40 KNOTS DOES NOT PERMIT DRY AIR TO PICK UP MUCH
MOISTURE IF IT TRAVEL SO FAST ACROSS THE LAKE). SO THINK THAT WE
WILL SEE ANOTHER 3 TO 5 INCHES ACROSS VILAS COUNTY FOR THE SUNDAY
EVENING THROUGH MONDAY NOON WITH LOCALLY HIGHER AMOUNTS NEAR THE
MICHIGAN BORDER.
UPPER RIDGING BEGINS TO ARRIVE MONDAY EVENING WHICH WILL CAUSE
WINDS TO BACK SUFFICIENTLY TO DIMINISH THE LAKE EFFECT SNOW TO
JUST FLURRIES. A CLIPPER SYSTEM WILL BRING INCREASING CLOUDS
TUESDAY AND MAYBE SOME SNOW SHOWERS TUESDAY NIGHT. NO MUCH
EXPECTED DUE TO VERY DRY AIR IN PLACE BEFORE IT/S ARRIVAL. THEN
MORE UPPER RIDGING FOR WEDNESDAY NIGHT THROUGH FRIDAY WITH MAINLY
DRY AND MILD WEATHER. A BIG DIFFERENCE IN THE MODELS FOR NEXT
SATURDAY OVER THE WESTERN GREAT LAKES SO MADE NO CHANGES TO
PREVIOUS FORECAST FOR THAT PERIOD.
MARINE...SOUTH WINDS AHEAD OF AN APPROACHING ARCTIC FRONT COULD
CAUSE HAZARDOUS CONDITIONS FOR SMALL CRAFTS THIS AFTERNOON AND
TONIGHT. AS THE ARCTIC COLD FRONT SWEEPS EAST OF THE AREA LATE
TONIGHT....WEST TO NORTHWEST GALES WILL DEVELOP SUNDAY MORNING
WHICH WILL CONTINUE INTO MONDAY AFTERNOON. THERE IS AN OUTSIDE
CHANCE THAT GUSTS COULD APPROACH OR REACH STORM FORCE OVER
NORTHERN DOOR COUNTY SUNDAY NIGHT.
&&
.AVIATION...FOR 00Z TAF ISSUANCE. MAIN CHGS WAS TO SHIFT AXIS OF
BEST SNOWS MORE TOWARD E-C WI.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 3 AM TO NOON CST SUNDAY FOR WIZ013-
020-021-031-037-038-045-048-073-074.
WIND ADVISORY FROM NOON SUNDAY TO MIDNIGHT CST SUNDAY NIGHT FOR
WIZ010>013-018>021-030-031-035>040-045-048>050-073-074.
WINTER WEATHER ADVISORY FROM 6 AM TO NOON CST SUNDAY FOR WIZ022-
039-040-049-050.
WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST SUNDAY
FOR WIZ010>012-018-019-030-035-036.
WIND ADVISORY FROM NOON SUNDAY TO 6 PM CST MONDAY FOR WIZ022.
WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 3 PM CST MONDAY
FOR WIZ005.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
543 PM CST SAT DEC 31 2011
.SHORT TERM...TONIGHT THROUGH TUESDAY
315 PM CST SAT DEC 31 2011
MAIN FORECAST CONCERNS ARE HIGH WIND POTENTIAL TONIGHT THROUGH
SUNDAY NIGHT AND WINTER WEATHER CONCERNS ON TOP OF THESE WINDS.
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS
SHOWED RIDGING BUILDING UP ALONG THE WEST COAST OF THE U.S. INTO
BRITISH COLUMBIA...A SPLIT TROUGH OVER THE CENTRAL PORTION OF NORTH
AMERICA...AND RIDGING OVER THE WESTERN GREAT LAKES AND OHIO VALLEY
REGIONS. WITHIN THE SPLIT TROUGH...A VERY POTENT SHORTWAVE WAS NEAR
GOODLAND KANSAS...AN UPPER LOW OVER SOUTHERN MANITOBA...AND A
SHORTWAVE ON ITS BACK SIDE IN SOUTHERN ALBERTA. MUCH FOCUS IN ON
THAT POTENT SHORTWAVE FOR THIS FORECAST. AT 12Z...WHEN IT WAS BACK
NEAR RIVERTON WYOMING...THE SOUNDING SHOWED A DROP IN THE TROPOPAUSE
OF 200MB AND A 500MB TEMP THAT COOLED 13C FROM THE PREVIOUS 00Z
SOUNDING. MODELS HAVE STRUGGLED WITH THIS SHORTWAVE WITH ALL OF THEM
NEEDING TO SHIFT MORE SOUTH AND DEEPER...ESPECIALLY THE NAM IN WHICH
ITS 30.12Z RUN FORECASTED THE SHORTWAVE TO BE IN EASTERN SOUTH
DAKOTA AT THIS TIME. AHEAD OF THE POTENT SHORTWAVE...A 995MB LOW WAS
LOCATED OVER SOUTHEAST NEBRASKA. SOUTH WINDS OF 35 TO 50 KT WERE
OCCURRING AT 925MB PER PROFILER DATA AHEAD OF THIS SURFACE
LOW...ADVECTING WARMER AIR INTO THE FORECAST AREA. TEMPERATURES HAVE
CLIMBED INTO THE 30S AND 40S...WARMEST IN NORTHEAST IOWA. ON THE
BACK SIDE OF THE SURFACE LOW ACROSS WESTERN PORTIONS OF NEBRASKA...
KANSAS AND ADJACENT STATES...SURFACE WINDS HAVE BEEN BLOWING HARD.
PEAK GUSTS OF 40-50 KT AND EVEN A FEW UP AROUND 60 KT HAVE BEEN
REPORTED. ALSO ON THE BACK SIDE OF THE LOW...PRECIPITATION HAS BEEN
FORMING OVER NEBRASKA IN THE DEFORMATION AXIS.
TONIGHT...FOCUS AGAIN IS MOSTLY ON THE POTENT SHORTWAVE. GOOD
MODEL AGREEMENT EXISTS THAT THIS SHORTWAVE LIFTS RAPIDLY NORTHEAST
INTO SOUTHERN LAKE MICHIGAN BY 12Z SUNDAY. THIS TRACK PLACES THE
BEST 500MB HEIGHT FALLS TO OUR SOUTH...HOWEVER...PLENTY OF DPVA
STILL OCCURS NORTH OF IT OVER THE FORECAST AREA. NEXT CONCERN IS THE
DEFORMATION PRECIPITATION DEVELOPING OVER NEBRASKA. VERY GOOD
AGREEMENT EXISTS THAT THIS PRECIPITATION WILL FORM INTO A
SOUTHWEST-NORTHEAST BAND FROM WESTERN IOWA INTO NORTHWEST WISCONSIN
THIS EVENING. IN FACT...THE BAND SHOULD INTENSIFY AS AN UPPER JET
STREAK DEVELOPS OVER NORTHERN MINNESOTA...PLACING THE BAND IN THE
FAVORABLE RIGHT ENTRANCE REGION. AS THIS JET CORE LIFTS INTO
NORTHERN ONTARIO LATE IN THE EVENING THROUGH THE OVERNIGHT...THE
DEFORMATION BAND OF PRECIPITATION LOOKS TO WEAKEN AS IT PUSHES EAST
INTO THE FORECAST AREA. MEANWHILE...A NEW DEFORMATION BAND AIDED BY
THE STRONGER 500MB HEIGHT FALLS IS FORECAST TO FORM FROM EASTERN
IOWA INTO NORTHEAST WISCONSIN AFTER MIDNIGHT. BOTH BANDS CERTAINLY
GIVE A GOOD OPPORTUNITY FOR PRECIPITATION...SO PRECIPITATION CHANCES
ARE AT 100. HOWEVER...HAVE HAD TO DELAY SOME OF THE PRECIPITATION
THIS EVENING BECAUSE OF THE FARTHER SOUTH TRACK WITH THE
SHORTWAVE/SURFACE LOW. SNOWFALL AMOUNTS ARE TRICKY TOO. WITH A
SLOWER MOVEMENT DUE TO THE SHORTWAVE BEING MORE AMPLIFIED...THE
PRECIPITATION MAY END UP AS RAIN OR RAIN/SNOW MIX FOR A COUPLE
HOURS. ONCE THE COLD AIR COMES IN...THERE MAY BE AN HOUR OF SOME
HEAVIER SNOW...BUT THEN THE DEFORMATION BANDS PUSH EAST. COMBINE
THAT WITH THE FACT THAT SNOW TO WATER RATIOS MAY ONLY END UP 10-15
TO 1...KEPT DOWN TOO AS A RESULT OF STRONGER WINDS DEVELOPING
BREAKING THE SNOW CRYSTALS APART. HAVE REDUCED SNOWFALL AMOUNTS SOME
TONIGHT...WITH NOW ONLY LESS THAN AN INCH SOUTH OF I-90 TO 1-2
INCHES ALONG AND NORTH OF THERE. NEXT CONCERN IS THE WINDS. AS THE
SURFACE LOW ASSOCIATED WITH THE SHORTWAVE LIFTS INTO SOUTHEAST
WISCONSIN AFTER MIDNIGHT...WINDS SHOULD KICK UP DRAMATICALLY IN ITS
WAKE. A TIGHT PRESSURE GRADIENT...COLD AIR ADVECTION FOR MIXING...
SUBSIDENCE AND RAPID PRESSURE RISES ARE ALL PRESENT...WHICH SHOULD
ALLOW WINDS TO CRANK UP. WITH A 50-60KT CORE OF WINDS FORECAST
BETWEEN 900-850MB...MUCH OF THIS SHOULD MIX DOWN. GREATEST POTENTIAL
TO SEE HIGH WIND WARNING IS OVER NORTHEAST IOWA WHERE ISALLOBARIC
FORCING IS MAXIMIZED. HAVE ISSUED THE WARNING IN THIS AREA. THE
COMBINATION OF THE WINDS AND SNOW WILL RESULT IN SOME BLOWING
SNOW...BUT THE EXTENT IS UNCERTAIN DUE TO AMOUNT OF SNOWFALL AND A
WARMER GROUND FROM THE EVENING HOURS. BECAUSE OF THIS...DID NOT
UPGRADE ANY WINTER WEATHER ADVISORIES TO WARNINGS.
SUNDAY INTO SUNDAY NIGHT...POTENT SHORTWAVE IS PROGGED TO LIFT
QUICKLY AWAY FROM THE AREA...WHILE THE SHORTWAVE OVER ALBERTA IS
FORECAST TO SLIDE ACROSS WESTERN PORTIONS OF THE FORECAST AREA
DURING THE DAY SUNDAY. INTERESTING FACT WITH THIS NEXT SHORTWAVE IS
THAT THE TROPOPAUSE DROPS TO 600MB OR SO. WITH THIS SHORTWAVE COMING
THROUGH...ALONG WITH THE SURFACE PRESSURE GRADIENT REMAINING TIGHT
AND DURING PEAK HEATING...FELT IT WAS PRUDENT TO KEEP THE HIGH WIND
WARNING GOING RIGHT THROUGH SUNDAY. ELSEWHERE...WIND ADVISORIES ARE
STILL APPROPRIATE...AND KEPT THE WINTER WEATHER ADVISORY GOING FOR
EASTERN PORTIONS OF THE FORECAST AREA UNTIL 15Z TO HANDLE ANY
LINGERING DEFORMATION PRECIPITATION AS WELL AS BLOWING SNOW. BLOWING
SNOW IS POSSIBLE ELSEWHERE...ESPECIALLY IN THE MORNING BEFORE SNOW
PROBABLY BECOMES COMPACTED ENOUGH TO NOT RESTRICT VISIBILITIES AS
MUCH. DID ALSO MAINTAIN 20-30 PERCENT CHANCES THROUGHOUT THE DAY
SUNDAY FOR ISOLATED-SCATTERED SNOW SHOWERS...PRODUCED BY WEAK LIFT
INDICATED IN THE LEFT-OVER STRATUS DECK BEHIND THE SYSTEM. DECIDED
TOO TO HAVE A MENTION OF FLURRIES SUNDAY NIGHT WITH THE STRATUS DECK
STILL AROUND...AS WELL AS NEUTRAL TO VERY WEAK LIFT IN THE CLOUDS.
NOTE THAT MUCH OF SUNDAY NIGHT SHOULD END UP IN SUBSIDENCE WITH THE
GENERAL UPPER TROUGH HEADING EAST. WITH COLD ADVECTION OCCURRING
THROUGHOUT SUNDAY AND SUNDAY NIGHT...TEMPERATURES LOOK TO PRETTY
MUCH HOLD STEADY OR SLIGHTLY FALL ON SUNDAY...FOLLOWED BY DROPPING
INTO THE TEENS AND POSSIBLY SINGLE DIGITS FOR NORTH CENTRAL
WISCONSIN. WINDS LOOK TO DIMINISH BELOW ADVISORY CRITERIA AROUND THE
CURRENT END TIME IN THE FORECAST...06Z MONDAY...THOUGH IT IS
POSSIBLE IT MAY NEED EXTENSION TO 12Z. WILL LET LATER SHIFTS TACKLE
THIS MORE.
MONDAY INTO MONDAY NIGHT...500MB HEIGHTS ARE FORECAST TO RISE QUITE
A BIT DURING THIS TIME PERIOD...IN RESPONSE TO UPPER RIDGING BEING
PUSHED EASTWARD INTO THE PLAINS. SUBSIDENCE ASSOCIATED WITH THE
BUILDING HEIGHTS SHOULD RESULT IN A DRY FORECAST WITH GRADUAL
CLEARING OF CLOUDS. WINDS LOOK TO ALSO GRADUAL DIMINISH...LIKELY
GOING TO CALM MONDAY NIGHT WHEN THE SURFACE RIDGE MOVES THROUGH.
DESPITE THE CLEARING OF CLOUDS...ANTICIPATING TEMPERATURES TO STILL
STRUGGLE TO RISE MUCH...GIVEN 850MB TEMPS FORECAST BETWEEN -14 TO
-18C MUCH OF THE DAY. GENERALLY FOLLOWED A BLEND OF GUIDANCE FOR
HIGHS. COULD SEE SOME BELOW ZERO TEMPERATURES MONDAY NIGHT...
ESPECIALLY IN THE TYPICAL COLD SPOTS OF WISCONSIN WITH SNOW LIKELY
ON THE GROUND...COMBINED WITH THE CLEARING SKIES AND DIMINISHING
WIND. IF THINGS SPEED UP A LITTLE MORE THAN WHAT IS FORECAST...A
RISING TEMPERATURE TREND MAY NEED TO BE INCLUDED OVER WESTERN
PORTIONS OF THE FORECAST AREA MONDAY NIGHT.
TUESDAY...THE FEATURE MODELS HAVE PUSHING THE UPPER RIDGE EASTWARD
INTO THE PLAINS IS A SHORTWAVE TROUGH...FORECAST OVER FAR EASTERN
MONTANA AT 12Z TUESDAY. THIS TROUGH WILL HEAD EAST INTO MINNESOTA BY
00Z WEDNESDAY...INITIATING A WARM ADVECTION PATTERN OVER THE
FORECAST AREA. AS A RESULT OF THIS WARM ADVECTION...LIKELY TO SEE
DEVELOPMENT/TRANSLATION OF MID AND HIGH CLOUDS INTO THE FORECAST
AREA. RAISED SKY COVER SOME...BUT MORE INCREASES MAY BE NECESSARY.
PRECIPITATION IS NOT EXPECTED DUE TO DRIER LOW LEVEL AIR AND MUCH OF
THE DPVA/THERMODYNAMIC FORCING PROGGED NORTHWEST OF THE FORECAST
AREA. CERTAINLY SOMETHING TO WATCH. 850MB TEMPS DO CLIMB UP TO -4 TO
-8C BY 00Z...SO HIGH TEMPERATURES SHOULD GET BACK UP INTO THE 20S
FOR MOST LOCATIONS.
.LONG TERM...TUESDAY NIGHT THROUGH SATURDAY
315 PM CST SAT DEC 31 2011
31.12 MODELS SHOWING A SHORTWAVE TROUGH MOVING ACROSS NORTHERN
MINNESOTA AND INTO CENTRAL WISCONSIN TUESDAY NIGHT. THIS TROUGH HAS
BEEN A FAIRLY CONSISTENT SIGNAL IN THE MODELS SO HAVE DECIDED TO
EXPAND PRECIPITATION CHANCES FURTHER SOUTH...MAINLY TO ALONG THE
I-94 CORRIDOR. TEMPERATURES WILL BE COLD ENOUGH TO ALLOW THE
PRECIPITATION TO FALL AS SNOW. LOOK FOR LOW TEMPERATURES TO RANGE
FROM THE MID TEENS ACROSS NORTH CENTRAL WISCONSIN TO AROUND 20
ACROSS NORTHEAST IOWA. A BROAD UPPER RIDGE IS EXPECTED TO SLIDE FROM
THE NORTHERN PLAINS AND INTO THE UPPER MISSISSIPPI RIVER VALLEY
WEDNESDAY INTO THURSDAY...WITH A GRADUAL WARMING TREND EXPECTED
ACROSS THE FORECAST AREA. 850 MB TEMPERATURES WILL START OUT AROUND
NEGATIVE 2 C EARLY WEDNESDAY AFTERNOON...WARMING TO AROUND PLUS 10 C
BY THURSDAY AFTERNOON. HAVE NUDGED TEMPERATURES TOWARDS THE ECMWF
WHICH SEEMS TO BE HANDLING TEMPERATURES BETTER OVERALL. QUIET
WEATHER IS ANTICIPATED WEDNESDAY THROUGH THURSDAY WITH HIGH PRESSURE
IN CONTROL. LOOK FOR HIGH TEMPERATURES MAINLY IN THE 30S ON
WEDNESDAY...WARMING INTO THE 40S BY THURSDAY. FRIDAY COULD BE EVEN
WARMER WITH TEMPS CLIMBING INTO THE UPPER 40S IN SOME LOCATIONS.
HAVE INCREASED HIGH A COUPLE OF DEGREES ON FRIDAY...BUT IF TRENDS
CONTINUE THEY WILL HAVE TO BE INCREASED FURTHER. THE RIDGE WILL PUSH
EAST THROUGH THE DAY ON FRIDAY AS A COLD FRONT SWINGS SOUTH FROM
CANADA AND THROUGH THE UPPER MIDWEST. THE OVERALL UPPER PATTERN
LOOKS TO TRANSITION TO A NORTHWEST FLOW SCENARIO IN THE WAKE OF THE
FRONT WITH A BROAD UPPER TROUGH SETTING UP ACROSS THE REGION. A
SHORTWAVE TROUGH IS EXPECTED TO MOVE ACROSS THE REGION ON SATURDAY
BRINGING A CHANCE OF LIGHT SNOW TO THE AREA.
&&
.AVIATION...TONIGHT AND SUNDAY
543 PM CST SAT DEC 31 2011
BIGGEST CONCERN IS ON WINDS AND VISIBILITIES WITH ANY FALLING OR
BLOWING SNOW. STRONG LOW PRESSURE WILL STRENGTHEN ACROSS IOWA THIS
EVENING AND THEN PUSH INTO SOUTHERN LAKE MICHIGAN BY SUNDAY
MORNING. A BAND OF PRECIPITATION WILL PUSH ACROSS THE TAF SITES
BETWEEN 05Z-14Z. WITH THE WARMER LOWER LAYERS..THE PRECIPITATION
WILL INITIALLY FALL AS RAIN OR A RAIN SNOW MIX BEFORE CHANGING
OVER TO ALL SNOW. THE PRESSURE GRADIENT WILL TIGHTENING LATE
TONIGHT...WITH WINDS INCREASING BEHIND THE ASSOCIATED COLD FRONT.
EXPECT NORTHWEST WINDS TO GUST TO 40 TO 50 KNOTS AT BOTH KLSE AND
KRST BEGINNING BETWEEN 07Z-10Z AND CONTINUING THROUGHOUT THE DAY
SUNDAY. IN ADDITION TO CAUSING STRONG CROSS WINDS ON NORTH SOUTH
RUNWAYS...VISIBILITIES WILL DROP INTO THE IFR CATEGORY WITH THE
EXPECTED SNOWFALL AND WINDS. THE LOWEST VISIBILITIES LOOK TO BE
FROM 08Z-14Z...WITH IMPROVING CONDITIONS AFTER THAT.
HOWEVER...SOME BLOWING SNOW WILL STILL BE POSSIBLE THROUGHOUT MUCH
OF THE DAY...BUT VISIBILITIES SHOULD BE IN THE 3SM TO 5SM RANGE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
315 PM CST SAT DEC 31 2011
WI...WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 6 AM CST SUNDAY
FOR WIZ041-053>055-061.
WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 6 AM CST
SUNDAY FOR WIZ032-033.
WIND ADVISORY FROM 6 AM SUNDAY TO MIDNIGHT CST SUNDAY NIGHT FOR
WIZ032-033-041-053>055-061.
WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM CST SUNDAY
FOR WIZ042>044.
WIND ADVISORY FROM 9 AM SUNDAY TO MIDNIGHT CST SUNDAY NIGHT FOR
WIZ017-029-034-042>044.
WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 9 AM CST
SUNDAY FOR WIZ017-029-034.
MN...WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 6 AM CST SUNDAY
FOR MNZ096.
WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 6 AM CST
SUNDAY FOR MNZ079-086>088-094-095.
WIND ADVISORY FROM 6 AM SUNDAY TO MIDNIGHT CST SUNDAY NIGHT FOR
MNZ079-086>088-094>096.
IA...HIGH WIND WARNING FROM MIDNIGHT TONIGHT TO MIDNIGHT CST SUNDAY
NIGHT FOR IAZ008-018-019-029-030.
WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 6 AM CST SUNDAY
FOR IAZ010-011-019-029-030.
WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 6 AM CST
SUNDAY FOR IAZ008-009-018.
WIND ADVISORY FROM 6 AM SUNDAY TO MIDNIGHT CST SUNDAY NIGHT FOR
IAZ009>011.
&&
$$
SHORT TERM...AJ
LONG TERM...WETENKAMP
AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
930 AM EST SUN JAN 1 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
A STRONG COLD FRONT WILL SWEEP ACROSS CENTRAL INDIANA THIS
MORNING...USHERING IN MUCH COLDER ARCTIC AIR FOR THE FIRST FEW DAYS
OF THE NEW YEAR ALONG WITH STRONG WINDS. SOME LIGHT PRECIPITATION
MAY ACCOMPANY THE FRONTAL PASSAGE. CHANCES FOR FLURRIES AND LIGHT
SNOW SHOWERS COME MONDAY INTO EARLY TUESDAY ACROSS NORTHERN AND
EASTERN PORTIONS OF THE FORECAST AREA AS A STRONG UPPER LEVEL
DISTURBANCE OVER THE GREAT LAKES PULLS AWAY SLOWLY. HIGH PRESSURE
WILL RETURN ON TUESDAY BRINGING DRY COLD WEATHER. A SLOW WARMING
TREND DURING THE SECOND HALF OF THE WEEK WILL BRING TEMPERATURES
BACK TO ABOVE NORMAL LEVELS BY FRIDAY.
&&
.NEAR TERM /TODAY/...
SURFACE ANALYSIS AS OF 08Z PLACES LOW PRESSURE OVER FAR EASTERN IOWA
WITH A COLD FRONT EXTENDING SOUTH THROUGH CENTRAL ILLINOIS. WARM
ADVECTION AND ISENTROPIC LIFT AHEAD OF THE FRONT HAD ENABLED
STRATOCU TO FORM OVER THE EASTERN HALF OF THE FORECAST AREA.
TEMPERATURES HAVE WARMED STEADILY SINCE MIDNIGHT IN THE WARM
ADVECTION...WITH MUCH OF THE FORECAST AREA IN THE 40S.
FOCUS FOR TODAY IS ON TEMPS AND WIND GUSTS AS THE FRONT SWEEPS
ACROSS THE REGION THIS MORNING. EXTRAPOLATION TO CURRENT OBS BRINGS
THE FRONT ACROSS THE STATE LINE AND INTO THE WABASH VALLEY AROUND
1130-12Z...PROGRESSING EASTWARD ACROSS THE FORECAST AREA THROUGHOUT
THE MORNING. STRONGER GUSTS ARE POST-FRONTAL AND WITH THAT IN
MIND...WILL BE DELAYING THE START TIME OF THE WIND ADVISORY ACROSS
THE WABASH VALLEY BACK TO 12Z TO MATCH UP WITH THE REST OF THE
HEADLINE ACROSS CENTRAL INDIANA. SEEING LIGHT PRECIP EARLY THIS
MORNING ACROSS CENTRAL MISSOURI WITHIN AREA OF DEEPER MOISTURE RIGHT
BEHIND THE FRONT. SHORT RANGE MODEL GUIDANCE FAIRLY CONSISTENT IN
BRINGING THIS AREA OF MOISTURE ACROSS THE FORECAST AREA THROUGH
18Z...WITH POTENTIAL FOR LIGHT RAIN OR SPRINKLES. AS THE COLDER AIR
STEADILY SPILLS INTO THE REGION...MAY SEE A FEW SNOWFLAKES MIX IN
WITH THE RAIN BEFORE THE PRECIP CHANCES END. WILL CONTINUE TO CARRY
LOW CHANCE POPS ACROSS NORTHERN HALF OF THE FORECAST AREA THROUGH
18Z WHERE DEEPEST MOISTURE WILL RESIDE.
MUCH GREATER FOCUS WILL BE ON THE GUSTY WINDS...ESPECIALLY BY THIS
AFTERNOON AS LOW LEVEL MIXING MAY EXTEND ALL THE WAY UP TO AROUND
5-6KFT AS COLD ADVECTION INTENSIFIES INTO THE REGION. THINK POTENTIAL
FOR STRONGEST WIND GUSTS WITHIN THE ADVISORY CATEGORY WILL TAKE
PLACE AFTER 16Z...PARTICULARLY IF CLOUDS CAN SCATTER FOR A PERIOD OF
TIME WHICH WOULD ENHANCE THE MIXING HEIGHTS INTO THE BOUNDARY LAYER.
THIS SEEMS PLAUSIBLE AS THE DRIER ARCTIC AIRMASS SURGES INTO THE
FORECAST AREA THIS AFTERNOON AND MODEL SOUNDINGS ARE SUPPORTIVE OF A
FEW HOURS WITH PARTLY CLOUDY OR POSSIBLY EVEN MOSTLY SUNNY SKIES.
POTENTIAL CONTINUES FOR WESTERLY SUSTAINEDS AT 20-30MPH WITH MAX
WIND GUSTS AROUND 50MPH.
TEMPS...HIGHS WILL TAKE PLACE DURING THE MORNING PRIOR TO FRONTAL
PASSAGE. UTILIZED RUC GUIDANCE TO GET THE NON-DIURNAL TREND FOR THE
DAY AND CAPTURE TEMPS THIS MORNING AHEAD OF THE FRONT. ENDED UP
SEVERAL DEGREES ABOVE GUIDANCE FOR HIGHS AS MOST LOCATIONS SHOULD BE
IN THE MID AND UPPER 40S BEFORE THE FRONT PASSES. MORE SUBSTANTIAL
TEMP FALLS INTO THE LOWER AND MID 30S SHOULD HOLD OFF UNTIL THE
AFTERNOON AS STRONGER COLD ADVECTION ARRIVES.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
FORECAST CHALLENGES FOCUS ON POTENTIAL FOR FLURRIES/LIGHT SNOW
SHOWERS THROUGH EARLY TUESDAY AS UPPER TROUGH DEEPENS OVER THE GREAT
LAKES AND MOVES ONLY SLOWLY OFF TO THE EAST.
WINDS WILL CONTINUE TO HOWL THIS EVENING WITH THE UPPER LEVELS
AMPLIFYING AS ADDITIONAL ENERGY DIVES INTO THE TROUGH. MODEL
SOUNDINGS CONTINUE TO SHOW MODEST MIXING THROUGH THE LOWER LEVELS
WELL INTO THE EVENING...WITH STRONGER WINDS WITHIN THE BOUNDARY
LAYER NOT SHIFTING EAST OF THE REGION UNTIL CLOSER TO MIDNIGHT. HAVE
THEREFORE CHOSEN TO EXTEND THE WIND ADVISORY THROUGH 03Z AS MAX
GUSTS MAY LINGER NEAR ADVISORY CRITERIA. GUSTS SHOULD SLOWLY WEAKEN
TO CLOSER TO 30-35MPH AFTER MIDNIGHT AS THE MIXING LEVEL DROPS. THE
AMPLIFICATION OF THE TROUGH ALOFT WILL ENABLE DEEPER LOW LEVEL
MOISTURE TO SPILL BACK SOUTH INTO THE FORECAST AREA WITH STRATOCU
EXPANDING ACROSS THE NORTHERN HALF OF THE FORECAST AREA.
PERSISTENT FORCING WITHIN THE MID LEVELS WILL FURTHER AMPLIFY THE
UPPER TROUGH INTO CENTRAL INDIANA ON MONDAY...BRINGING A VERY COLD
BLUSTERY DAY WITH AN ABUNDANCE OF CLOUD COVER. LOW LEVEL FLOW
LARGELY OUT OF THE W/NW SHOULD KEEP MORE PERSISTENT SNOW SHOWERS
CONFINED TO JUST FAR NORTHEAST COUNTIES OR POSSIBLY EVEN COMPLETELY
NORTH OF THE FORECAST AREA FOR MUCH OF THE DAY. WILL MAINTAIN
MENTION OF SCATTERED FLURRIES BACK WEST TO NEAR THE I-65 CORRIDOR
WITH THE FORCING ALOFT PRESENT. LOW LEVEL FLOW DOES VEER TO A MORE
NW DIRECTION MONDAY NIGHT...BUT OVERALL WIND PROFILES ARE NOT AS
FAVORABLE AS PREVIOUS MODEL GUIDANCE INDICATED IN BRINGING MORE
PERSISTENT SNOW SHOWERS INTO A LARGER PORTION OF THE FORECAST AREA.
MODELS CONTINUE TO ADVERTISE THE DEVELOPMENT OF A SINGLE DOMINANT
BAND OFF LAKE MICHIGAN MONDAY NIGHT/EARLY TUESDAY. LOW LEVEL WIND
TRAJECTORIES SUGGESTIVE OF BRINGING REMNANTS OF THE BAND INTO
DELAWARE/MADISON/RANDOLPH COUNTIES AND WILL CONTINUE WITH LOW CHANCE
POPS THROUGH TUESDAY MORNING IN THESE AREAS. AM NOT AS CONFIDENT IN
WESTERN EXTENT TO FLURRIES/LIGHT SNOW SHOWERS WITH TRAJECTORIES NOT
AS VEERED. WHILE PRESENCE OF THE FORCING ALOFT AND BACK SIDE UPPER
JET DIVING INTO THE TROUGH COULD BOTH BE FACTORS IN KEEPING FLURRIES
GOING FOR MUCH OF THE NIGHT ALL THE WAY BACK TO THE I-65 CORRIDOR...
HAVE ELECTED TO KEEP ANY MENTION OF PRECIP TO THE NORTHEAST OF THE
INDY METRO AND LAFAYETTE AREAS AT THIS TIME.
HIGH PRESSURE RIDGE FINALLY BUILDS IN TUESDAY WITH LOW LEVEL FLOW
BACKING AND WEAKENING. THIS WILL END ANY FLURRIES AND ALLOW LOW
CLOUDS TO SCATTER BY TUESDAY AFTERNOON. MAINLY CLEAR SKIES WILL
CONTINUE INTO TUESDAY EVENING BEFORE CLOUDS RETURN AS A WEAK
DISTURBANCE ALOFT MOVES INTO THE GREAT LAKES. NOT EXPECTING ANY
PRECIPITATION WITH THIS FEATURE AS FORCING REMAINS CONFINED WELL
NORTH OF THE REGION.
TEMPS...LEANED TOWARDS MET GUIDANCE THROUGH MONDAY NIGHT AS NAM
TRADITIONALLY SAMPLES ARCTIC AIRMASS BETTER THAN OTHER MODELS.
LEANED TOWARDS COOLER MOS FOR HIGHS ON TUESDAY AS TEMPS WILL LIKELY
HOLD IN THE MID 20S ACROSS MUCH OF THE REGION. TEMPS NOT LIKELY TO
FALL MUCH LOWER THAN 20 DEGREES TUESDAY NIGHT AS INCREASING CLOUDS
AND WARM ADVECTION TAKES ROOT AHEAD OF THE UPPER LEVEL DISTURBANCE
MOVING INTO THE GREAT LAKES.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
STRONG RIDGING ALOFT WILL DOMINATE THE MAJORITY OF THE EXTENDED
FORECAST. AS A RESULT...DRY CONDITIONS WILL PREVAIL FROM WEDNESDAY
THROUGH FRIDAY. THE NEXT CHANCE FOR ANY PRECIP WILL BE AT THE END
OF THE LONG TERM PERIOD WHEN A SYSTEM TRACKS ACROSS THE GREAT LAKES
REGION. HOWEVER...MODELS ARE STILL KEEPING THE BEST LIFT AND PRECIP
NORTH OF CENTRAL INDIANA. INITIALIZATION IS ONLY SHOWING SLIGHT
CHANCE POPS ON SATURDAY...WHICH STILL LOOKS REASONABLE. FURTHER
OUT...THE NEXT SYSTEM TO WATCH WILL BE COMING OUT OF THE PLAINS ON
SUNDAY. AT THIS TIME...INITIALIZATION NUMBERS ARE FAVORING THE GFS.
THE EURO IS NOT EVEN HINTING AT A DISTURBANCE AT THIS TIME AND
CONTINUES WITH ZONAL FLOW UNTIL DAY 9.
TEMPS WILL CLIMB BACK TO ABOVE NORMAL AND REMAIN THAT WAY FOR THE
DURATION OF THE EXTENDED PERIOD. HIGHS WILL TOP OFF IN THE 40S...AND
EVEN LOW 50S BY FRIDAY. OVERNIGHT LOWS WILL ALSO BE ABOVE NORMAL
WITH READINGS IN THE UPPER 20S/LOW 30S.
&&
.AVIATION /DISCUSSION FOR THE 01/15Z KIND TAF UPDATE/...
MINOR TWEEKS MADE IN KIND TAF PER OBSERVATIONS. OTHERWISE...NO OTHER
CHANGES NEEEDED AT THIS TIME. PREVIOUS AVIATION DISCUSSION FOLLOW...
THE MAIN CONCERN OF TAF PERIOD CONTINUES TO BE THE STRONG WINDS.
CONDITIONS WILL GENERALLY BE VFR CATEGORY FOR ENTIRE PERIOD EXCEPT
FOR SOME BRIEF MVFR CEILINGS THIS MORNING WITH FRONTAL PASSAGE.
SO...FOCUS TURNS TO THE GUSTY WINDS. WINDS ARE VEERING TO THE WEST
AT THIS TIME AS COLD FRONT APPROACHES KLAF...AND WILL REMAIN
WESTERLY FOR DURATION OF TAF PERIOD. WINDS WILL REALLY RAMP UP BY
MID MORNING AND WILL BE THE STRONGEST THROUGH THIS AFTERNOON WITH
SUSTAINED SPEEDS OF 24 TO 28 KTS AND GUSTS AS HIGH AS 40 KTS.
THERE COULD STILL BE SOME WIND SHEAR ISSUES AT FIRST...BUT THIS
SHOULD BE PRETTY SHORT-LIVED AS SURFACE WINDS INCREASE QUICKLY.
WINDS WILL WEAKEN A TAD THIS EVENING...BUT WILL REMAIN STRONG
THROUGH TOMORROW MORNING.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR INZ021-028>031-
035>049-051>057-060>065-067>072.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...RYAN
SHORT TERM...RYAN
LONG TERM....TDUD
AVIATION...TDUD/JH
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
639 AM EST SUN JAN 1 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
A STRONG COLD FRONT WILL SWEEP ACROSS CENTRAL INDIANA THIS
MORNING...USHERING IN MUCH COLDER ARCTIC AIR FOR THE FIRST FEW DAYS
OF THE NEW YEAR ALONG WITH STRONG WINDS. SOME LIGHT PRECIPITATION
MAY ACCOMPANY THE FRONTAL PASSAGE. CHANCES FOR FLURRIES AND LIGHT
SNOW SHOWERS COME MONDAY INTO EARLY TUESDAY ACROSS NORTHERN AND
EASTERN PORTIONS OF THE FORECAST AREA AS A STRONG UPPER LEVEL
DISTURBANCE OVER THE GREAT LAKES PULLS AWAY SLOWLY. HIGH PRESSURE
WILL RETURN ON TUESDAY BRINGING DRY COLD WEATHER. A SLOW WARMING
TREND DURING THE SECOND HALF OF THE WEEK WILL BRING TEMPERATURES
BACK TO ABOVE NORMAL LEVELS BY FRIDAY.
&&
.NEAR TERM /TODAY/...
SURFACE ANALYSIS AS OF 08Z PLACES LOW PRESSURE OVER FAR EASTERN IOWA
WITH A COLD FRONT EXTENDING SOUTH THROUGH CENTRAL ILLINOIS. WARM
ADVECTION AND ISENTROPIC LIFT AHEAD OF THE FRONT HAD ENABLED
STRATOCU TO FORM OVER THE EASTERN HALF OF THE FORECAST AREA.
TEMPERATURES HAVE WARMED STEADILY SINCE MIDNIGHT IN THE WARM
ADVECTION...WITH MUCH OF THE FORECAST AREA IN THE 40S.
FOCUS FOR TODAY IS ON TEMPS AND WIND GUSTS AS THE FRONT SWEEPS
ACROSS THE REGION THIS MORNING. EXTRAPOLATION TO CURRENT OBS BRINGS
THE FRONT ACROSS THE STATE LINE AND INTO THE WABASH VALLEY AROUND
1130-12Z...PROGRESSING EASTWARD ACROSS THE FORECAST AREA THROUGHOUT
THE MORNING. STRONGER GUSTS ARE POST-FRONTAL AND WITH THAT IN
MIND...WILL BE DELAYING THE START TIME OF THE WIND ADVISORY ACROSS
THE WABASH VALLEY BACK TO 12Z TO MATCH UP WITH THE REST OF THE
HEADLINE ACROSS CENTRAL INDIANA. SEEING LIGHT PRECIP EARLY THIS
MORNING ACROSS CENTRAL MISSOURI WITHIN AREA OF DEEPER MOISTURE RIGHT
BEHIND THE FRONT. SHORT RANGE MODEL GUIDANCE FAIRLY CONSISTENT IN
BRINGING THIS AREA OF MOISTURE ACROSS THE FORECAST AREA THROUGH
18Z...WITH POTENTIAL FOR LIGHT RAIN OR SPRINKLES. AS THE COLDER AIR
STEADILY SPILLS INTO THE REGION...MAY SEE A FEW SNOWFLAKES MIX IN
WITH THE RAIN BEFORE THE PRECIP CHANCES END. WILL CONTINUE TO CARRY
LOW CHANCE POPS ACROSS NORTHERN HALF OF THE FORECAST AREA THROUGH
18Z WHERE DEEPEST MOISTURE WILL RESIDE.
MUCH GREATER FOCUS WILL BE ON THE GUSTY WINDS...ESPECIALLY BY THIS
AFTERNOON AS LOW LEVEL MIXING MAY EXTEND ALL THE WAY UP TO AROUND
5-6KFT AS COLD ADVECTION INTENSIFIES INTO THE REGION. THINK POTENTIAL
FOR STRONGEST WIND GUSTS WITHIN THE ADVISORY CATEGORY WILL TAKE
PLACE AFTER 16Z...PARTICULARLY IF CLOUDS CAN SCATTER FOR A PERIOD OF
TIME WHICH WOULD ENHANCE THE MIXING HEIGHTS INTO THE BOUNDARY LAYER.
THIS SEEMS PLAUSIBLE AS THE DRIER ARCTIC AIRMASS SURGES INTO THE
FORECAST AREA THIS AFTERNOON AND MODEL SOUNDINGS ARE SUPPORTIVE OF A
FEW HOURS WITH PARTLY CLOUDY OR POSSIBLY EVEN MOSTLY SUNNY SKIES.
POTENTIAL CONTINUES FOR WESTERLY SUSTAINEDS AT 20-30MPH WITH MAX
WIND GUSTS AROUND 50MPH.
TEMPS...HIGHS WILL TAKE PLACE DURING THE MORNING PRIOR TO FRONTAL
PASSAGE. UTILIZED RUC GUIDANCE TO GET THE NON-DIURNAL TREND FOR THE
DAY AND CAPTURE TEMPS THIS MORNING AHEAD OF THE FRONT. ENDED UP
SEVERAL DEGREES ABOVE GUIDANCE FOR HIGHS AS MOST LOCATIONS SHOULD BE
IN THE MID AND UPPER 40S BEFORE THE FRONT PASSES. MORE SUBSTANTIAL
TEMP FALLS INTO THE LOWER AND MID 30S SHOULD HOLD OFF UNTIL THE
AFTERNOON AS STRONGER COLD ADVECTION ARRIVES.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
FORECAST CHALLENGES FOCUS ON POTENTIAL FOR FLURRIES/LIGHT SNOW
SHOWERS THROUGH EARLY TUESDAY AS UPPER TROUGH DEEPENS OVER THE GREAT
LAKES AND MOVES ONLY SLOWLY OFF TO THE EAST.
WINDS WILL CONTINUE TO HOWL THIS EVENING WITH THE UPPER LEVELS
AMPLIFYING AS ADDITIONAL ENERGY DIVES INTO THE TROUGH. MODEL
SOUNDINGS CONTINUE TO SHOW MODEST MIXING THROUGH THE LOWER LEVELS
WELL INTO THE EVENING...WITH STRONGER WINDS WITHIN THE BOUNDARY
LAYER NOT SHIFTING EAST OF THE REGION UNTIL CLOSER TO MIDNIGHT. HAVE
THEREFORE CHOSEN TO EXTEND THE WIND ADVISORY THROUGH 03Z AS MAX
GUSTS MAY LINGER NEAR ADVISORY CRITERIA. GUSTS SHOULD SLOWLY WEAKEN
TO CLOSER TO 30-35MPH AFTER MIDNIGHT AS THE MIXING LEVEL DROPS. THE
AMPLIFICATION OF THE TROUGH ALOFT WILL ENABLE DEEPER LOW LEVEL
MOISTURE TO SPILL BACK SOUTH INTO THE FORECAST AREA WITH STRATOCU
EXPANDING ACROSS THE NORTHERN HALF OF THE FORECAST AREA.
PERSISTENT FORCING WITHIN THE MID LEVELS WILL FURTHER AMPLIFY THE
UPPER TROUGH INTO CENTRAL INDIANA ON MONDAY...BRINGING A VERY COLD
BLUSTERY DAY WITH AN ABUNDANCE OF CLOUD COVER. LOW LEVEL FLOW
LARGELY OUT OF THE W/NW SHOULD KEEP MORE PERSISTENT SNOW SHOWERS
CONFINED TO JUST FAR NORTHEAST COUNTIES OR POSSIBLY EVEN COMPLETELY
NORTH OF THE FORECAST AREA FOR MUCH OF THE DAY. WILL MAINTAIN
MENTION OF SCATTERED FLURRIES BACK WEST TO NEAR THE I-65 CORRIDOR
WITH THE FORCING ALOFT PRESENT. LOW LEVEL FLOW DOES VEER TO A MORE
NW DIRECTION MONDAY NIGHT...BUT OVERALL WIND PROFILES ARE NOT AS
FAVORABLE AS PREVIOUS MODEL GUIDANCE INDICATED IN BRINGING MORE
PERSISTENT SNOW SHOWERS INTO A LARGER PORTION OF THE FORECAST AREA.
MODELS CONTINUE TO ADVERTISE THE DEVELOPMENT OF A SINGLE DOMINANT
BAND OFF LAKE MICHIGAN MONDAY NIGHT/EARLY TUESDAY. LOW LEVEL WIND
TRAJECTORIES SUGGESTIVE OF BRINGING REMNANTS OF THE BAND INTO
DELAWARE/MADISON/RANDOLPH COUNTIES AND WILL CONTINUE WITH LOW CHANCE
POPS THROUGH TUESDAY MORNING IN THESE AREAS. AM NOT AS CONFIDENT IN
WESTERN EXTENT TO FLURRIES/LIGHT SNOW SHOWERS WITH TRAJECTORIES NOT
AS VEERED. WHILE PRESENCE OF THE FORCING ALOFT AND BACK SIDE UPPER
JET DIVING INTO THE TROUGH COULD BOTH BE FACTORS IN KEEPING FLURRIES
GOING FOR MUCH OF THE NIGHT ALL THE WAY BACK TO THE I-65 CORRIDOR...
HAVE ELECTED TO KEEP ANY MENTION OF PRECIP TO THE NORTHEAST OF THE
INDY METRO AND LAFAYETTE AREAS AT THIS TIME.
HIGH PRESSURE RIDGE FINALLY BUILDS IN TUESDAY WITH LOW LEVEL FLOW
BACKING AND WEAKENING. THIS WILL END ANY FLURRIES AND ALLOW LOW
CLOUDS TO SCATTER BY TUESDAY AFTERNOON. MAINLY CLEAR SKIES WILL
CONTINUE INTO TUESDAY EVENING BEFORE CLOUDS RETURN AS A WEAK
DISTURBANCE ALOFT MOVES INTO THE GREAT LAKES. NOT EXPECTING ANY
PRECIPITATION WITH THIS FEATURE AS FORCING REMAINS CONFINED WELL
NORTH OF THE REGION.
TEMPS...LEANED TOWARDS MET GUIDANCE THROUGH MONDAY NIGHT AS NAM
TRADITIONALLY SAMPLES ARCTIC AIRMASS BETTER THAN OTHER MODELS.
LEANED TOWARDS COOLER MOS FOR HIGHS ON TUESDAY AS TEMPS WILL LIKELY
HOLD IN THE MID 20S ACROSS MUCH OF THE REGION. TEMPS NOT LIKELY TO
FALL MUCH LOWER THAN 20 DEGREES TUESDAY NIGHT AS INCREASING CLOUDS
AND WARM ADVECTION TAKES ROOT AHEAD OF THE UPPER LEVEL DISTURBANCE
MOVING INTO THE GREAT LAKES.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
STRONG RIDGING ALOFT WILL DOMINATE THE MAJORITY OF THE EXTENDED
FORECAST. AS A RESULT...DRY CONDITIONS WILL PREVAIL FROM WEDNESDAY
THROUGH FRIDAY. THE NEXT CHANCE FOR ANY PRECIP WILL BE AT THE END
OF THE LONG TERM PERIOD WHEN A SYSTEM TRACKS ACROSS THE GREAT LAKES
REGION. HOWEVER...MODELS ARE STILL KEEPING THE BEST LIFT AND PRECIP
NORTH OF CENTRAL INDIANA. INITIALIZATION IS ONLY SHOWING SLIGHT
CHANCE POPS ON SATURDAY...WHICH STILL LOOKS REASONABLE. FURTHER
OUT...THE NEXT SYSTEM TO WATCH WILL BE COMING OUT OF THE PLAINS ON
SUNDAY. AT THIS TIME...INITIALIZATION NUMBERS ARE FAVORING THE GFS.
THE EURO IS NOT EVEN HINTING AT A DISTURBANCE AT THIS TIME AND
CONTINUES WITH ZONAL FLOW UNTIL DAY 9.
TEMPS WILL CLIMB BACK TO ABOVE NORMAL AND REMAIN THAT WAY FOR THE
DURATION OF THE EXTENDED PERIOD. HIGHS WILL TOP OFF IN THE 40S...AND
EVEN LOW 50S BY FRIDAY. OVERNIGHT LOWS WILL ALSO BE ABOVE NORMAL
WITH READINGS IN THE UPPER 20S/LOW 30S.
&&
.AVIATION /DISCUSSION FOR THE 01/12Z TAF ISSUANCE/...
THE MAIN CONCERN OF TAF PERIOD CONTINUES TO BE THE STRONG WINDS.
CONDITIONS WILL GENERALLY BE VFR CATEGORY FOR ENTIRE PERIOD EXCEPT
FOR SOME BRIEF MVFR CEILINGS THIS MORNING WITH FRONTAL PASSAGE.
SO...FOCUS TURNS TO THE GUSTY WINDS. WINDS ARE VEERING TO THE WEST
AT THIS TIME AS COLD FRONT APPROACHES KLAF...AND WILL REMAIN
WESTERLY FOR DURATION OF TAF PERIOD. WINDS WILL REALLY RAMP UP BY
MID MORNING AND WILL BE THE STRONGEST THROUGH THIS AFTERNOON WITH
SUSTAINED SPEEDS OF 24 TO 28 KTS AND GUSTS AS HIGH AS 40 KTS.
THERE COULD STILL BE SOME WIND SHEAR ISSUES AT FIRST...BUT THIS
SHOULD BE PRETTY SHORT-LIVED AS SURFACE WINDS INCREASE QUICKLY.
WINDS WILL WEAKEN A TAD THIS EVENING...BUT WILL REMAIN STRONG
THROUGH TOMORROW MORNING.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR INZ021-028>031-
035>049-051>057-060>065-067>072.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...RYAN
SHORT TERM...RYAN
LONG TERM....TDUD
AVIATION...TDUD
AREA FORECAST DISCUSSION
NWS CARIBOU ME
913 AM EST SUN JAN 1 2012
.SYNOPSIS...
HIGH PRESSURE WILL BUILD BRIEFLY ACROSS THE REGION TODAY. AN OCCLUDED
FRONT WILL APPROACH FROM THE WEST THIS EVENING AND CROSS THE
REGION EARLY MONDAY MORNING...FOLLOWED BY A STRONG ARCTIC FRONT
LATE MONDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...NO MAJOR CHANGES NEEDED FOR THIS UPDATE. HAVE ADJUSTED
SKY COVER A BIT FOR CURRENT CONDITIONS BUT NO OTHER CHANGES
NEEDED.
PREVIOUS DISCUSSION...CLOUDS HANGING ON ACROSS MUCH OF THE CWA
THIS MORNING AS EVIDENT FROM THE LATEST IR SATL IMAGERY. MOISTURE
HANGING ON BELOW 925MBS W/AIRMASS DRY ABOVE THIS LAYER. INVERSION
IS IN PLACE AND IS SHOWN TO HANG ON FOR A WHILE THIS MORNING PER
THE LATEST RUC SOUNDINGS WHICH IS SUPPORT BY THE 00Z NAM. A W FLOW
TAKES OVER LATER THIS MORNING HELPING TO ERODE CLOUDS ACROSS THE
CENTRAL AND DOWNEAST REGION. ACROSS THE NORTH AND WEST, CLOUDS
COULD HANG ON LONGER W/INVERSION HANGING AS SHOWN BY THE SOUNDINGS
SHOWING MOISTURE STAYING TRAPPED AT AROUND 900MBS. DECIDED TO HANG
ON TO SOME CLOUDS LONGER ACROSS THE NORTHERN AND WESTERN AREAS
INTO EARLY AFTERNOON W/MORE SUN ACROSS THE CENTRAL AND DOWNEAST
AREAS. OBVIOUSLY THIS WILL PLAY INTO THE MAX TEMPERATURE FCST
TODAY. ADJUSTED THE DAYCREW/S MAXES FOR TODAY UPWARD ACROSS THE
CWA W/UPPER 20S TO LOWER 30S ACROSS THE NORTH AND WEST AND UPPER
30S TO LOWER 40S FOR CENTRAL AND DOWNEAST AREAS.
TONIGHT COULD BE INTERESTING AS AN OCCLUDED FRONT APCHS FROM THE W
LATER TONIGHT W/PRECIP MOVING IN LATER TONIGHT. LATEST MDL
SOUNDINGS SHOW TEMPERATURES TO BE WARM ENOUGH ACROSS THE CENTRAL
AND DOWNEAST AREAS FOR MAINLY RAIN. ACROSS THE NORTHERN AND
WESTERN AREAS, THINGS LOOK TO BE DIFFERENT AS TEMPERATURES COOL
OFF EARLY TONIGHT AND THEN LEVEL OFF BEFORE RISING WELL AFTER
MIDNIGHT. WX ELEMENT IN THESE AREAS WILL BE IN THE FORM OF SOME
SNOW BUT A TRANSITION TO FREEZING PRECIP IS POSSIBLE. THE NAM AND GFS
BOTH SHOW A WARM LAYER SETTING UP AGAIN FROM 925-850MBS W/A COLD
LAYER AT THE SFC. THIS WILL SET THE STAGE FOR ANOTHER FRZA EVENT.
THE TIMING LOOKS TO BE BRIEF W/FZRA/FZDZ. THERE ALSO LOOKS TO BE A
PERIOD OF SLEET POSSIBLE. BEST SNOW ACCUMULATION WILL BE ACROSS
THE FAR NORTH AND WEST MAINLY NORTH AND WEST OF CAR,PQI & HUL. THE
PRECIP FROM THICKNESS TOOL WAS USED FOR THE WX ELEMENT. QPF IS A
BLEND OF HPC/GFS AND THE NAM WHICH SHOWS THE HIGHEST AREAS ACROSS
DOWNEAST AND AND EASTERN SECTIONS. ADDED SOME ICE ACCUMULATION
MAINLY FOR THE NORTH AND WEST W/<.10". DECIDED TO HOLD OFF ON ANY
WINTER WEATHER ADVISORIES AS THIS LOOKS TO BE LATE 2ND PERIOD INTO
THE 3RD PERIOD. THE DAYCREW CAN ASSESS THIS FURTHER W/LATER MODEL
RUNS. THE HWO WILL ADDRESS THIS POTENTIAL.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
THE OCCLUDED FRONT MOVES EAST EARLY MONDAY MORNING WITH STEADY
PRECIPITATION ENDING EARLY. EXPECT MAX TEMPERATURES TO OCCUR EARLY
IN THE DAY BEFORE FALLING A FEW DEGREES DURING THE AFTERNOON AS
SLIGHTLY COOLER FILTERS IN BEHIND THE OCCLUSION. ONCE THE STEADY
PRECIPITATION ENDS MONDAY MORNING IT WILL REMAIN MOSTLY CLOUDY. AN
ARCTIC COLD FRONT WILL APPROACH LATER MONDAY AFTERNOON AND THEN
SWEEP EAST ACROSS THE FA MONDAY NIGHT. THERE WILL BE THE CHANCE
FOR SNOW SHOWERS ACROSS NORTHERN PORTIONS OF THE FA WITH THE
PASSAGE OF THE ARCTIC BOUNDARY...HOWEVER THE BIG STORY WILL BE
THE STRONG COLD ADVECTION LATER MONDAY NIGHT AND TUESDAY.
TEMPERATURES WILL FALL TO ZERO TO 5 ABOVE ZERO ACROSS MUCH OF
NORTHERN MAINE AND LOW TO MID TEENS ACROSS MOST OF DOWNEAST MAINE
BY EARLY TUESDAY MORNING. TEMPERATURES ON TUESDAY WILL NOT RECOVER
MUCH FROM THE EARLY MORNING LOWS WITH HIGHS ONLY EXPECTED TO BE IN
THE SINGLE DIGITS ABOVE ZERO TO AROUND 10 ABOVE NORTH AND 15 TO 20
DOWNEAST. ALONG WITH THE COLD TEMPERATURES WILL COME THE CHANCE
FOR SOME SNOW SHOWERS OR FLURRIES ACROSS THE NORTH WITH PARTLY
CLOUDY SKIES DOWNEAST.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
IT STILL LOOKS RELATIVELY QUIET THROUGH THE LONG TERM WITH NO BIG
STORMS IN SIGHT. TEMPERATURES WILL REMAIN BELOW NORMAL THROUGH
MUCH OF THE PERIOD. BRISK NORTHWEST FLOW WILL CONTINUE TUESDAY
NIGHT AND WEDNESDAY WITH MAINLY DRY CONDITIONS AS HIGH PRESSURE
MOVES EAST. A WEAK DISTURBANCE WILL CROSS THE REGION THURSDAY
FOLLOWED BY HIGH PRESSURE THURSDAY NIGHT. A CLIPPER TYPE SYSTEM
COULD BRING SOME SNOW SHOWERS TO THE REGION BY THE END OF THE
PERIOD.
&&
.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
NEAR TERM: IFR/MVFR CONDITIONS WILL GO TO VFR LATER THIS MORNING
W/THE NORTHERN TERMINALS HANGING ONTO MVFR CIGS A WHILE LONGER
W/THE INVERSION. VFR THIS EVENING DROPPING BACK TO MVFR LATER
TONIGHT ACROSS THE NORTHERN TERMINALS W/IFR CONDITIONS FOR BGR AND
BHB NEAR OR AFTER 06Z.
SHORT TERM: MVFR CONDITIONS POSSIBLE IN ANY SCATTERED SNOW SHOWERS
MAINLY ACROSS NORTHERN SECTIONS MONDAY AND TUESDAY OTHERWISE
MAINLY VFR.
&&
.MARINE...
NEAR TERM: DECIDED TO GO TO A GALE WARNING STARTING AFTER 06Z AND
CONTINUING INTO MONDAY AS LLVL JET OF 45-50KT HITS THE WATERS.
GUSTS TO HIT 35KTS. WINDS WILL BE TOUGH TO MIX DOWN W/WAA INITIALLY
AND THEN AS THE OCCLUSION MOVES THROUGH SW WINDS WILL HAVE A CHC
TO MIX DOWN AS LLVLS BEGIN TO COOL. DAYCREW/S WAVE HEIGHTS WERE
MATCHING CLOSE THE LATEST SWAN AND WNAWAVE AND DECIDED TO STAY
CLOSE THE CURRENT FCST OF SEAS BUILDING TO 3-6 FT.
SHORT TERM: GALE FORCE CONDITIONS MONDAY INTO MONDAY NIGHT THEN
SCA CONDITIONS ARE EXPECTED TUESDAY INTO WEDNESDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...GALE WARNING FROM 3 AM TO 7 PM EST MONDAY FOR ANZ050>052.
&&
$$
NEAR TERM...HASTINGS/HEWITT
SHORT TERM...DUDA
LONG TERM...DUDA
AVIATION...HASTINGS/HEWITT
MARINE...HASTINGS/HEWITT/DUDA
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
1028 AM EST SUN JAN 1 2012
.SYNOPSIS...
A STRONG COLD FRONT IN THE OHIO VALLEY WILL MOVE EAST TODAY AND
CROSS THE REGION LATE THIS AFTERNOON AND THIS EVENING. BEHIND THE
FRONT HIGH PRESSURE WILL BUILD BRINGING GUSTY NORTHWESTERLY WINDS
AND COLDER TEMPERATURES ON MONDAY AND TUESDAY...WITH SOME OF THE
COLDEST READINGS OF THE SEASON EXPECTED TUESDAY NIGHT. HIGH
PRESSURE CROSSES THE REGION ON WEDNESDAY...WITH MODERATING
TEMPERATURES EXPECTED FOR THE LATTER PORTION OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
CLEAR SKIES ATTM ACROSS THE CWA AT 14Z WITH WEAK HIGH PRESSURE
ACROSS THE REGION. VSBL SATL IMAGERY SHOWS EXTENSIVE AREA OF
CLOUDS JUST TO THE WEST HEADING EAST. SOME DISSIPATION OF CLOUD
COVER IS EXPECTED AS THE AREA CROSSES THE MOUNTAINS...BUT HAVE
KEPT SOME CLOUDS IN FOR THIS AFTN.
WATER VAPOR IMAGERY SHOWING INTENSE SHRTWV TROUGH EXTENDING FROM
CNTRL IN INTO THE WRN TN. A DECENT 50 HPA SPEED MAX OF NEARLY 100
KT EXTENDS JUST EAST OF THE TROUGH AXIS. THIS WILL ALLOW DECENT
WAA TO OCCUR THIS AFTERNOON ACROSS THE CWA...WHICH IS REFLECTED
IN UNSEASONABLY WARM TEMPS IN THE GRIDS OF MID 50S TO LWR 60S. 12Z
LWX SOUNDING SUPPORTS AROUND 60F IN DC/BALT METRO REGION THIS AFTN.
HI RES MDL GUIDANCE SHOWING QUITE A SPREAD IN PRECIP CHANCE ACROSS
THE CWA THIS AFTERNOON. THE INITIAL BAND OF REFLECTIVITY THAT WAS
LOCATED ACROSS ERN OH-WRN PA AND CNTRL WV IS BREAKING UP AS IT
MOVES EAST. THE MDLS SEEM TO HAVE A HANDLE ON THAT.
ANOTHER AREA OF PRECIP HAS BROKEN OUT ACROSS CNTRL TN-KY THIS
MORNING. THE 00Z NCEP-HIRES 4KM NMM WRF MODEL ACTUALLY SHOWS THIS
BETTER THAN THE 00Z NCEP-HIRES 4KM ARW WRF...AND LATER RUNS OF
THE 3KM HRRR FROM 11Z SUPPORT THE NMM-WRF SOLN. BOTH THE NCEP 4KM
WRF-NMM AND GSD EXPERIMENTAL 3KM HRRR RUNS SUGGEST SCATTERED COVERAGE
OF SHOWERS ACROSS MAINLY THE NRN PORTION OF THE CWA BETWEEN 18Z
AND 00Z/2ND. THE 4KM WRF-ARW IS DRY THOUGH FOR THIS SAME PERIOD.
OUR LOCAL 4KM WRF NMM AND ARW RUNS ARE SIMILAR TO THE NCEP RUNS.
WITH THE STEEPENED LAPSE RATES EXPECTED LATER THIS AFTERNOON...SOME
SHOWERS COULD PRODUCE GUSTY WINDS OF 30-35 KT AND SMALL HAIL...
SOMETHING THAT WAS REPORTED EARLIER IN INDIANAPOLIS AS THE SYSTEM
MOVED THROUGH THERE. WILL KEEP EYE ON THIS POTENTIAL...SINCE SPCL
MARINE WARNINGS COULD BE NEEDED LATE THIS AFTERNOON/EARLY EVENING.
ATTM...DO NOT THINK THERE IS SUFFICIENT INSTABILITY FOR THUNDER WITH
THIS ACTIVITY.
WILL CONTINUE TO EVALUATE NEED FOR WIND ADVSRY. ATTM...AM NOT
CONFIDENT OF THE AREA...BUT EXPECT SOMETHING MIGHT BE NEEDED FOR
THE WESTERN 5 COUNTIES FOR TONIGHT.
FOR THE WESTERN 5 UPSLOPE COUNTIES...AM STILL THINKING THE TRANSITION
FROM RAIN TO SNOW SHOWER ACTIVITY WILL BE BETWEEN 21Z AND 00Z.
INITIAL SNOW ACCUM TONIGHT WILL DEPEND ON HOW MUCH SNOW CAN FALL
BEFORE DRYING TAKES PLACE. INSTABILITY IS PRETTY INTENSE STARTING
THIS EVENING OUT WEST...SO INTENSE SNOW SHOWER ACTIVITY AFTER 00Z
COULD PRODUCE A QUICK SEVERAL INCHES IN AN HOUR OR SO BEFORE
DRYING WINS OUT. OTHERWISE...HEADLINES REMAIN AS IS FOR NOW.
PREVIOUS DISCUSSIONS FOLLOW.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
ERY WK WX WILL BE DOMINATED BY INTENSE CAA IN STRONG NW FLOW.
MID-ATLC WILL RESIDE BENEATH DEEP UPR TROF AND BTWN LOPRES OVR
CANADIAN MARITIMES AND HIPRES BUILDING IN FROM MS VLY. COOLER...
YET STILL SEASONABLE...TEMPS ARE XPCD MON/MON NGT BEFORE H8 TEMPS
PLUMMET TO AOB -15C TUE...TRANSLATING TO MAXIMA RNGG FROM TEENS AT
HIGHER ELEVATIONS TO M30S CENTRAL FOOTHILLS/PIEDMONT AND SRN MD.
MINIMA TUE NGT SHUD BE COLDEST OF SEASON THUS FAR...TEENS MOST
LOCATIONS.
STEEP LLVL LAPSE RATES/GOOD INSTABILITY...DEEP MOIST LYR...AND
UPSLOPE FLOW SHUD LEAD TO SIGNIFICANT SNOWFALL IN FAVORED AREAS...
AND WSW IN EFFECT THRU TUE WHERE ACCUMS IN EXCESS OF 6IN/12HR AND
8IN/24HR LIKELY. E OF ALLEGHENY FRONT...DOWNSLOPING WILL RESTRICT
PRECIP TO SCATTERED -SNSH ACRS THE POTOMAC HIGHLANDS...WITH ONLY
FLURRIES ACRS SHENANDOAH VLY AND BLUE RIDGE. ELSEWHERE...BKN/OVC
CONDS IN SC. UPSLOPE SN SHUD TAPER OFF LATE TUE AS MOIST LYR
BECOMES QUITE SHALLOW AND WINDS BCM MORE WLY.
GUSTY NW WINDS MON/TUE...AT LEAST 35 KTS ACRS MTNS...WILL CREATE
BLOWING/DRIFTING SN IN WRNG AREA...AND NEAR BLIZZARD CONDS/ZERO VSBY
PSBL. WIND CHILL VALUES ALSO OF CONCERN...XPCD TO DROP TO AS LOW AS
-10F ON HIGHER RIDGES. WIND CHILLS IN TEENS/SOME SINGLE DIGITS/
FCST FOR REMAINDER OF CWA...WITH LOWEST VALUES MON NGT AND ERY
TUE.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
SFC RDG PASSES S OF RGN ON WED...WITH CONTD BLW-NRML TEMPS FOR
MID-ATLC. WED NGT/THU...SHRTWV TROF PASSES N OF RGN...PROVIDING
ANOTHER OPPORTUNITY FOR UPSLOPE SNSH...MOSTLY LGT...ACRS WRN
ZONES. ZONAL FLOW ESTABLISHES FOR THU THRU SAT...ALLOWING TEMPS TO
MODERATE AND RISE TO ABV NRML. NEXT SHRTWV TROF/CDFNT POISED TO
IMPACT RGN NEXT WKEND.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
CLEAR SKIES WILL GIVE WAY TO MORE SCT CLOUDS THIS AFTERNOON.
SOUTHERN WINDS INCREASE AS WELL WITH GUSTS IN THE L20 KT RANGE
STARTING 17-18Z ACRS DC/BALT TAF SITES. SCT SHOWER ACTIVITY LATE
THIS AFTERNOON...WITH A FEW SHOWERS CAPABLE OF PRODUCING BRIEF
GUSTS TO 35KT AND BREIF MVFR CIGS.
FOR TONIGHT...AT DCA-BWI-IAD...EXPECT SCT-BKN CIGS 040-060
THROUGH 04Z...THEN SOME CLEARING. BKN040 HANGS MOST OF THE NIGHT
AT MRB. VFR CONDS SHUD PREVAIL MUCH OF THE WEEK. GUSTY NW WINDS...IN
EXCESS OF 30 KTS AT TIMES...FCST FOR MON/TUE...BEFORE HI PRESSURE BUILDS
IN WED...BRINGING LIGHTER WINDS.
&&
.MARINE...
EXPECT GUSTY WINDS TO COMMENCE AROUND NOON TIME FROM THE SOUTH.
WILL CONTINUE SCA.
SHWRS EXPECTED FROM LATE THIS AFTN ESPECIALLY ACROSS THE NORTHERN
THIRD OF THE WATERS. GIVEN DYNAMIC WIND FIELD ALOFT...ANY SHWRS MAY BE
ACCOMPANIED BY GUSTS IN EXCESS OF 34 KT. IF SHWRS FORM AND APRCH
THE WATERS...SPCL MARINE WRNGS MAY BE NEEDED.
ADZY EXTDD FOR WATER THRU MON AS TIGHT PRES GRADIENT WILL SUPPORT 25
KT GUSTS. GUSTS AT LEAST AS INTENSE WILL CONT INTO TUE NGT AND SCA
WILL BE NECESSARY DURG THIS PERIOD. RISK FOR GALES INCR OVNGT MON
AND TUE...AND MAY PERSIST INTO TUE NGT. HIPRES BUILDS IN
WED...LEADING TO DIMINISHED WINDS.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...WINTER STORM WARNING FROM 1 AM MONDAY TO 5 PM EST TUESDAY FOR
MDZ501.
VA...WINTER STORM WARNING FROM 1 AM MONDAY TO 5 PM EST TUESDAY FOR
VAZ503.
WV...WINTER STORM WARNING FROM 1 AM MONDAY TO 5 PM EST TUESDAY FOR
WVZ501-503-505.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST MONDAY FOR ANZ530>543.
&&
$$
SYNOPSIS...SMZ
NEAR TERM...SMZ
SHORT TERM...MRK
LONG TERM...SBK
AVIATION...CJL/SMZ
MARINE...SMZ/MRK
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
731 AM EST SUN JAN 1 2012
.SYNOPSIS...
AN INTENSIFYING LOW PRESSURE SYSTEM WILL PUSH INTO THE GREAT LAKES
TODAY, BRINGING A STRONG COLD FRONT AND GUSTY WINDS ACROSS THE
UPPER OHIO VALLEY. THE COLDEST AIR OF THE SEASON WILL PUSH IN
BEHIND THE FRONT WITH SNOW SHOWERS EXPECTED TONIGHT INTO TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WITH 730AM UPDATE...MADE SOME MINOR TWEAKS TO CLOUD COVER AND
TIMING OF PRECIPITATION BASED ON RADAR/SATELLITE TRENDS...WHICH
SLIGHTLY SPEEDS UP ARRIVAL OF SHOWERS. OTHERWISE...GOING FORECAST
LOOKS GOOD. PREVIOUS DISCUSSION FOLLOWS.
THE LATEST RUC MID-LEVEL ANALYSIS INDICATES A 500MB TROUGH AXIS
EXTENDING FROM THE UPPER MIDWEST INTO THE MISSOURI VALLEY. AHEAD OF
THIS FEATURE, A WEAK RIDGE IS SHIFTING EAST OF THE UPPER OHIO
VALLEY. A DEEP LAYER OF DRY AIR IS IN PLACE, WITH STRATOCUMULUS
ASSOCIATED WITH A 1000-900MB LAYER MOISTURE PUSHING NORTHEAST OF
THE AREA. AT THE SURFACE, AS 1000MB LOW IS CENTERED ACROSS
NORTHERN ILLINOIS. WITH A 1021MB SURFACE HIGH CENTERED OFF THE
CAROLINA COAST, THE PRESSURE GRADIENT IS TIGHTENING ACROSS THE
OHIO VALLEY. IN ADDITION, A COLD FRONT EXTENDS SOUTHWARD OF THE
LOW ACROSS THE MISSOURI VALLEY.
TODAY...THE TROUGH WILL DIG INTO THE OHIO VALLEY AND THE SURFACE LOW
WILL MOVE NORTHEASTWARD ACROSS THE LP OF MICHIGAN, SWINGING THE
FRONT ACROSS THE UPPER OHIO VALLEY AND TIGHTENING THE PRESSURE
GRADIENT ACROSS THE AREA. THE FRONT WILL MOSTLY BE DRY WITH ITS
PASSAGE, ALTHOUGH WITH A TIGHT THERMAL GRADIENT AND HIRES MODELS
INDICATING SUFFICIENT FORCING, CHANCE POPS ARE FORECAST WITH ITS
PASSAGE.
THE MAIN WEATHER IMPACT TODAY WILL BE GUSTY WINDS WITH THE
FRONTAL PASSAGE AND DIURNAL MIXING IN CAA IN THE WAKE OF THE FRONT.
NAM/WRF-NMM SOLUTIONS SUPPORT SUSTAINED WINDS OF 20-25KTS WITH GUSTS
OF 35-40KTS AND THE ONGOING WIND ADVISORY. EXPECT THE GUSTS TO PICK
UP LATE THIS MORNING ACROSS EASTERN OHIO AND ACROSS THE REST OF THE
AREA BY EARLY AFTERNOON. FOR TEMPS, HIGHS WILL BE REACHED MOSTLY BY
18Z, AS CAA KICKS IN. TEMPS ARE A MAV/MET BLEND, RANGING FROM NEAR
50 ACROSS NORTHERN WV AND SOUTHWEST PA TO THE MID 40S FOR AREAS
NORTHWEST OF PITTSBURGH AND ACROSS THE EASTERN RIDGES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
THERE IS NAM/GFS AGREEMENT THAT THE MID-LEVEL TROUGH WILL DEEPEN AND
BECOME MORE AMPLIFIED AS IT MOVES ACROSS THE OHIO VALLEY TO THE EAST
COAST SUNDAY NIGHT THROUGH TUESDAY.
SUNDAY NIGHT...THE MID-LEVEL TROUGH WILL INSTIGATE SHOWERS ACROSS
THE AREA WITH LOW-LEVEL THICKNESSES QUICKLY DECREASING AND TURNING
PRECIPITATION OVER TO ALL SNOW SHOWERS. THE SURFACE LOW WILL PUSH
NORTHEAST INTO ONTARIO WITH GUSTS WEAKENING WITH THE DECREASE OF
MIXING WITH THE LOSS OF DIURNAL HEATING. WITH A TIGHTENED PRESSURE
GRADIENT, WINDS WILL STILL GUST AT 20-30KTS OVERNIGHT. FOR LOWS,
ONGOING CAA WILL BE IN PLACE, ALTHOUGH CLOUD COVERAGE WILL SERVE TO
COUNTER COLDER AIR ALOFT. LOWS WILL RANGE FROM THE LOWER 20S ACROSS
THE EASTERN RIDGES TO THE MID 20S ELSEWHERE. A LOW-LEVEL FLOW OUT OF
290 DEGREES WILL LIMIT LAKE EFFECT INITIALLY WITH AN INCH
FORECAST OVERNIGHT FOR THE I-80 CORRIDOR.
MONDAY AND MONDAY NIGHT...850MB FLOW WILL SHIFT TO
WEST-NORTHWESTERLY BY 18Z MONDAY AND TAP INTO A HURON FETCH AS IT
SHIFTS TO NORTHWESTERLY BY 00Z TUESDAY. THIS WILL ALLOW FOR LAKE
EFFECT SNOW SHOWERS AND UPSLOPING EVENT TO BEGIN IN EARNEST. WITH
850MB TEMPS NEAR -13C AND A WARM LAKE ERIE WITH TEMPS NEAR 4C, THE
TEMP DIFFERENTIAL WILL BE SUFFICIENT ALONG WITH A DEEP ISOTHERMAL
PROFILE. THUS, ACCUMULATIONS ARE FORECAST OF 4 TO 8 INCHES WITH BANDING OF
SNOWFALL ACROSS THE LAKE EFFECT ZONES AND UPSLOPING FOR THE
RIDGES. EXPECT 2 TO 4 INCHES SOUTH OF I-80 AND NORTH OF PITTSBURGH
WITH 1 TO 3 INCHES FOR AREAS SOUTH AND WEST OF PITTSBURGH.
TUESDAY...ONGOING LAKE EFFECT SNOW EVENT WILL BEGIN TO WIND DOWN
AS A SURFACE HIGH AND LOW-LEVEL RIDGING BUILD INTO THE UPPER OHIO
VALLEY. A LOWERING SUBSIDENCE INVERSION WILL MOSTLY DIMINISH THE
MORE PERSISTENT ACCUMULATING SNOW SHOWERS FOR THE RIDGES AND I-80
CORRIDOR BY THE AFTERNOON HOURS WITH SNOW SHOWERS COMING TO AN END
ELSEWHERE. THE CORE OF THE COLDEST AIR WILL HAVE BUILT IN, WITH
HIGHS STRUGGLING TO REACH THE LOWER 20S ACROSS MUCH OF THE AREA.
GUSTY WINDS OF 20-25KTS ALONG WILL YIELD WIND CHILLS IN THE
SINGLE DIGITS ACROSS THE LOWLANDS AND BELOW ZERO ACROSS THE HIGHER
ELEVATIONS MONDAY THROUGH TUESDAY.
BY THE END OF THIS EVENT, STORM TOTAL ACCUMULATIONS OF 8 TO 12
INCHES WILL BE POSSIBLE FOR THE RIDGES WITH THE I-80 CORRIDOR
GETTING 6 TO 10 INCHES. THUS, LAKE EFFECT SNOW AND WINTER STORM
WATCHES HAVE BEEN UPGRADED TO WARNINGS. THE NEXT TIER OF COUNTIES
SOUTH OF I-80 AND NORTH OF PITTSBURGH MAY NEED ADVISORIES, HOWEVER
AT THIS TIME, CONFIDENCE IN ACCUMULATIONS REACHING 12-HOUR/24-HOUR
CRITERIA IS TOO LOW THERE. THUS, THE WINTER STORM WATCH FOR
JEFFERSON AND CLARION COUNTIES REMAINS IN EFFECT.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THERE IS REASONABLE NAEFS/ECMWF MEAN AGREEMENT THAT HIGH PRESSURE WILL
CROSS THE AREA ON TUESDAY NIGHT, BRINGING A DRY FORECAST AND A
RESPITE FROM SNOW SHOWERS. WITH THE COLDEST AIR OF THE SEASON SET IN
AND RADIATIONAL COOLING POSSIBLE, LOWS TUESDAY NIGHT WILL RANGE FROM
THE SINGLE DIGITS ACROSS THE EASTERN RIDGES TO THE LOWER TEENS
ACROSS THE REMAINDER OF THE AREA.
GFSE/ECMWF BLEND WAS USED FOR THE REMAINDER OF THE PERIOD. A ZONAL
MID-LEVEL FLOW WILL BE IN PLACE FOR WEDNESDAY WITH THE SLIGHT CHANCE
OF SNOW SHOWERS. A SHORT WAVE WILL CROSS THE AREA ON WEDNESDAY NIGHT
INTO THURSDAY BRINGING A BETTER CHANCE OF SNOW SHOWERS. WEAK SURFACE
RIDGING IS PROGGED TO DRY THE FORECAST OUT FOR THURSDAY NIGHT INTO
FRIDAY. A FRONT IS THEN PROGGED TO CROSS THE UPPER OHIO VALLEY FOR
THE EARLY WEEKEND. TEMPS WILL BE PROGRESSIVELY WARMER MID-WEEK INTO
THE WEEKEND, AT AROUND 5 DEGREES BELOW NORMAL ON WEDNESDAY AND
WARMING EACH DAY TO 10 DEGREES ABOVE NORMAL BY FRIDAY AND SATURDAY.
&&
.AVIATION /13Z SUNDAY THROUGH THURSDAY/...
SKIES WILL BE CLEAR EARLY THIS MORNING AHEAD OF A STRONG COLD
FRONT APPROACHING FROM THE GREAT LAKES. VFR CIGS WITH SHOWERS
AHEAD OF AND BEHIND THE FRONT. PRESSURE GRADIENT WILL TIGHTEN
SIGNIFICANTLY AHEAD OF THE FRONT WITH WINDS SHIFTING FROM SOUTH TO
SOUTHWEST AND GUSTS OVER 30KTS. AS UPPER LEVEL TROUGH ADVANCES
EAST FROM THE GREAT LAKES THIS AFTERNOON EXPECT GENERAL MVFR CIGS
WITH A FEW LIGHT SHOWERS AND WINDS BECOMING WEST AND GUSTING
30-35KTS. STRONG COLD ADVECTION WILL BRING LIGHT SNOW SHOWERS
LATE AFTERNOON OR EVENING AND CONTINUE INTO THE OVERNIGHT WITH
WEST WINDS REMAINING GUSTY.
OUTLOOK...MONDAY THROUGH THURSDAY
GUSTY WINDS WILL REMAIN MONDAY AND TURN NORTHWEST WITH IFR
RESTRICTIONS POSSIBLE WITH SNOW SHOWERS MONDAY THROUGH TUESDAY
NIGHT. VFR CONDITIONS WILL RETURN WEDNESDAY BEFORE THE NEXT
DISTURBANCE BRINGS THE CHANCE OF SNOW SHOWERS WITH RESTRICTIONS ON
THURSDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WIND ADVISORY FROM 11 AM THIS MORNING TO 10 PM EST THIS
EVENING FOR MDZ001.
WINTER STORM WARNING FROM 1 AM MONDAY TO 4 PM EST TUESDAY FOR
MDZ001.
OH...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR OHZ039>041-
048>050-057>059-068-069.
PA...WIND ADVISORY FROM 11 AM THIS MORNING TO 10 PM EST THIS
EVENING FOR PAZ007>009-013>016-020>023-029-031-073>076.
WINTER STORM WARNING FROM 1 AM MONDAY TO 4 PM EST TUESDAY FOR
PAZ074-076.
LAKE EFFECT SNOW WARNING FROM 1 AM MONDAY TO 4 PM EST TUESDAY
FOR PAZ007>009.
WINTER STORM WATCH FROM LATE TONIGHT THROUGH TUESDAY EVENING
FOR PAZ015-016.
WV...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR WVZ001>004-012.
WIND ADVISORY FROM 11 AM THIS MORNING TO 10 PM EST THIS
EVENING FOR WVZ021>023-041.
WINTER STORM WARNING FROM 1 AM MONDAY TO 4 PM EST TUESDAY FOR
WVZ023-041.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
634 AM EST SUN JAN 1 2012
.SYNOPSIS...
AN INTENSIFYING LOW PRESSURE SYSTEM WILL PUSH INTO THE GREAT LAKES
TODAY, BRINGING A STRONG COLD FRONT AND GUSTY WINDS ACROSS THE
UPPER OHIO VALLEY. THE COLDEST AIR OF THE SEASON WILL PUSH IN
BEHIND THE FRONT WITH SNOW SHOWERS EXPECTED TONIGHT INTO TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE LATEST RUC MID-LEVEL ANALYSIS INDICATES A 500MB TROUGH AXIS
EXTENDING FROM THE UPPER MIDWEST INTO THE MISSOURI VALLEY. AHEAD OF
THIS FEATURE, A WEAK RIDGE IS SHIFTING EAST OF THE UPPER OHIO
VALLEY. A DEEP LAYER OF DRY AIR IS IN PLACE, WITH STRATOCUMULUS
ASSOCIATED WITH A 1000-900MB LAYER MOISTURE PUSHING NORTHEAST OF
THE AREA. AT THE SURFACE, AS 1000MB LOW IS CENTERED ACROSS
NORTHERN ILLINOIS. WITH A 1021MB SURFACE HIGH CENTERED OFF THE
CAROLINA COAST, THE PRESSURE GRADIENT IS TIGHTENING ACROSS THE
OHIO VALLEY. IN ADDITION, A COLD FRONT EXTENDS SOUTHWARD OF THE
LOW ACROSS THE MISSOURI VALLEY.
TODAY...THE TROUGH WILL DIG INTO THE OHIO VALLEY AND THE SURFACE LOW
WILL MOVE NORTHEASTWARD ACROSS THE LP OF MICHIGAN, SWINGING THE
FRONT ACROSS THE UPPER OHIO VALLEY AND TIGHTENING THE PRESSURE
GRADIENT ACROSS THE AREA. THE FRONT WILL MOSTLY BE DRY WITH ITS
PASSAGE, ALTHOUGH WITH A TIGHT THERMAL GRADIENT AND HIRES MODELS
INDICATING SUFFICIENT FORCING, CHANCE POPS ARE FORECAST WITH ITS
PASSAGE.
THE MAIN WEATHER IMPACT TODAY WILL BE GUSTY WINDS WITH THE
FRONTAL PASSAGE AND DIURNAL MIXING IN CAA IN THE WAKE OF THE FRONT.
NAM/WRF-NMM SOLUTIONS SUPPORT SUSTAINED WINDS OF 20-25KTS WITH GUSTS
OF 35-40KTS AND THE ONGOING WIND ADVISORY. EXPECT THE GUSTS TO PICK
UP LATE THIS MORNING ACROSS EASTERN OHIO AND ACROSS THE REST OF THE
AREA BY EARLY AFTERNOON. FOR TEMPS, HIGHS WILL BE REACHED MOSTLY BY
18Z, AS CAA KICKS IN. TEMPS ARE A MAV/MET BLEND, RANGING FROM NEAR
50 ACROSS NORTHERN WV AND SOUTHWEST PA TO THE MID 40S FOR AREAS
NORTHWEST OF PITTSBURGH AND ACROSS THE EASTERN RIDGES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
THERE IS NAM/GFS AGREEMENT THAT THE MID-LEVEL TROUGH WILL DEEPEN AND
BECOME MORE AMPLIFIED AS IT MOVES ACROSS THE OHIO VALLEY TO THE EAST
COAST SUNDAY NIGHT THROUGH TUESDAY.
SUNDAY NIGHT...THE MID-LEVEL TROUGH WILL INSTIGATE SHOWERS ACROSS
THE AREA WITH LOW-LEVEL THICKNESSES QUICKLY DECREASING AND TURNING
PRECIPITATION OVER TO ALL SNOW SHOWERS. THE SURFACE LOW WILL PUSH
NORTHEAST INTO ONTARIO WITH GUSTS WEAKENING WITH THE DECREASE OF
MIXING WITH THE LOSS OF DIURNAL HEATING. WITH A TIGHTENED PRESSURE
GRADIENT, WINDS WILL STILL GUST AT 20-30KTS OVERNIGHT. FOR LOWS,
ONGOING CAA WILL BE IN PLACE, ALTHOUGH CLOUD COVERAGE WILL SERVE TO
COUNTER COLDER AIR ALOFT. LOWS WILL RANGE FROM THE LOWER 20S ACROSS
THE EASTERN RIDGES TO THE MID 20S ELSEWHERE. A LOW-LEVEL FLOW OUT OF
290 DEGREES WILL LIMIT LAKE EFFECT INITIALLY WITH AN INCH
FORECAST OVERNIGHT FOR THE I-80 CORRIDOR.
MONDAY AND MONDAY NIGHT...850MB FLOW WILL SHIFT TO
WEST-NORTHWESTERLY BY 18Z MONDAY AND TAP INTO A HURON FETCH AS IT
SHIFTS TO NORTHWESTERLY BY 00Z TUESDAY. THIS WILL ALLOW FOR LAKE
EFFECT SNOW SHOWERS AND UPSLOPING EVENT TO BEGIN IN EARNEST. WITH
850MB TEMPS NEAR -13C AND A WARM LAKE ERIE WITH TEMPS NEAR 4C, THE
TEMP DIFFERENTIAL WILL BE SUFFICIENT ALONG WITH A DEEP ISOTHERMAL
PROFILE. THUS, ACCUMULATIONS ARE FORECAST OF 4 TO 8 INCHES WITH BANDING OF
SNOWFALL ACROSS THE LAKE EFFECT ZONES AND UPSLOPING FOR THE
RIDGES. EXPECT 2 TO 4 INCHES SOUTH OF I-80 AND NORTH OF PITTSBURGH
WITH 1 TO 3 INCHES FOR AREAS SOUTH AND WEST OF PITTSBURGH.
TUESDAY...ONGOING LAKE EFFECT SNOW EVENT WILL BEGIN TO WIND DOWN
AS A SURFACE HIGH AND LOW-LEVEL RIDGING BUILD INTO THE UPPER OHIO
VALLEY. A LOWERING SUBSIDENCE INVERSION WILL MOSTLY DIMINISH THE
MORE PERSISTENT ACCUMULATING SNOW SHOWERS FOR THE RIDGES AND I-80
CORRIDOR BY THE AFTERNOON HOURS WITH SNOW SHOWERS COMING TO AN END
ELSEWHERE. THE CORE OF THE COLDEST AIR WILL HAVE BUILT IN, WITH
HIGHS STRUGGLING TO REACH THE LOWER 20S ACROSS MUCH OF THE AREA.
GUSTY WINDS OF 20-25KTS ALONG WILL YIELD WIND CHILLS IN THE
SINGLE DIGITS ACROSS THE LOWLANDS AND BELOW ZERO ACROSS THE HIGHER
ELEVATIONS MONDAY THROUGH TUESDAY.
BY THE END OF THIS EVENT, STORM TOTAL ACCUMULATIONS OF 8 TO 12
INCHES WILL BE POSSIBLE FOR THE RIDGES WITH THE I-80 CORRIDOR
GETTING 6 TO 10 INCHES. THUS, LAKE EFFECT SNOW AND WINTER STORM
WATCHES HAVE BEEN UPGRADED TO WARNINGS. THE NEXT TIER OF COUNTIES
SOUTH OF I-80 AND NORTH OF PITTSBURGH MAY NEED ADVISORIES, HOWEVER
AT THIS TIME, CONFIDENCE IN ACCUMULATIONS REACHING 12-HOUR/24-HOUR
CRITERIA IS TOO LOW THERE. THUS, THE WINTER STORM WATCH FOR
JEFFERSON AND CLARION COUNTIES REMAINS IN EFFECT.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THERE IS REASONABLE NAEFS/ECMWF MEAN AGREEMENT THAT HIGH PRESSURE WILL
CROSS THE AREA ON TUESDAY NIGHT, BRINGING A DRY FORECAST AND A
RESPITE FROM SNOW SHOWERS. WITH THE COLDEST AIR OF THE SEASON SET IN
AND RADIATIONAL COOLING POSSIBLE, LOWS TUESDAY NIGHT WILL RANGE FROM
THE SINGLE DIGITS ACROSS THE EASTERN RIDGES TO THE LOWER TEENS
ACROSS THE REMAINDER OF THE AREA.
GFSE/ECMWF BLEND WAS USED FOR THE REMAINDER OF THE PERIOD. A ZONAL
MID-LEVEL FLOW WILL BE IN PLACE FOR WEDNESDAY WITH THE SLIGHT CHANCE
OF SNOW SHOWERS. A SHORT WAVE WILL CROSS THE AREA ON WEDNESDAY NIGHT
INTO THURSDAY BRINGING A BETTER CHANCE OF SNOW SHOWERS. WEAK SURFACE
RIDGING IS PROGGED TO DRY THE FORECAST OUT FOR THURSDAY NIGHT INTO
FRIDAY. A FRONT IS THEN PROGGED TO CROSS THE UPPER OHIO VALLEY FOR
THE EARLY WEEKEND. TEMPS WILL BE PROGRESSIVELY WARMER MID-WEEK INTO
THE WEEKEND, AT AROUND 5 DEGREES BELOW NORMAL ON WEDNESDAY AND
WARMING EACH DAY TO 10 DEGREES ABOVE NORMAL BY FRIDAY AND SATURDAY.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
SKIES WILL BE CLEAR EARLY THIS MORNING AHEAD OF A STRONG COLD
FRONT APPROACHING FROM THE GREAT LAKES. VFR CIGS WITH SHOWERS
AHEAD OF AND BEHIND THE FRONT. PRESSURE GRADIENT WILL TIGHTEN
SIGNIFICANTLY AHEAD OF THE FRONT WITH WINDS SHIFTING FROM SOUTH TO
SOUTHWEST AND GUSTS OVER 30KTS. AS UPPER LEVEL TROUGH ADVANCES
EAST FROM THE GREAT LAKES THIS AFTERNOON EXPECT GENERAL MVFR CIGS
WITH A FEW LIGHT SHOWERS AND WINDS BECOMING WEST AND GUSTING
30-35KTS. STRONG COLD ADVECTION WILL BRING LIGHT SNOW SHOWERS
LATE AFTERNOON OR EVENING AND CONTINUE INTO THE OVERNIGHT WITH
WEST WINDS REMAINING GUSTY.
OUTLOOK...MONDAY THROUGH THURSDAY
GUSTY WINDS WILL REMAIN MONDAY AND TURN NORTHWEST WITH IFR
RESTRICTIONS POSSIBLE WITH SNOW SHOWERS MONDAY THROUGH TUESDAY
NIGHT. VFR CONDITIONS WILL RETURN WEDNESDAY BEFORE THE NEXT
DISTURBANCE BRINGS THE CHANCE OF SNOW SHOWERS WITH RESTRICTIONS ON
THURSDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WIND ADVISORY FROM 11 AM THIS MORNING TO 10 PM EST THIS
EVENING FOR MDZ001.
WINTER STORM WARNING FROM 1 AM MONDAY TO 4 PM EST TUESDAY FOR
MDZ001.
OH...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR OHZ039>041-
048>050-057>059-068-069.
PA...WIND ADVISORY FROM 11 AM THIS MORNING TO 10 PM EST THIS
EVENING FOR PAZ007>009-013>016-020>023-029-031-073>076.
WINTER STORM WARNING FROM 1 AM MONDAY TO 4 PM EST TUESDAY FOR
PAZ074-076.
LAKE EFFECT SNOW WARNING FROM 1 AM MONDAY TO 4 PM EST TUESDAY
FOR PAZ007>009.
WINTER STORM WATCH FROM LATE TONIGHT THROUGH TUESDAY EVENING
FOR PAZ015-016.
WV...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR WVZ001>004-012.
WIND ADVISORY FROM 11 AM THIS MORNING TO 10 PM EST THIS
EVENING FOR WVZ021>023-041.
WINTER STORM WARNING FROM 1 AM MONDAY TO 4 PM EST TUESDAY FOR
WVZ023-041.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
947 AM CST SUN JAN 1 2012
.UPDATE...INCREASE POPS ACROSS MN ZONES THIS MORNING AS AREA OF
ENHANCED MOISTURE WITHIN 85/70H LATER ADVECTS SOUTHEASTWARD.
LATEST RUC13 ANALYSIS SHOWS -35C/50H COLD POOL IS MOVING ACROSS
CWA THIS MORNING. ACCUMULATIONS OF AN INCH OR LESS ARE POSSIBLE.
VERY WEAK OMEGA EVIDENT IN FCST ACROSS MOST OF CWA TODAY...EXCEPT
ERN WISC ZONES WHERE LES WARNING CONTINUES. WIND ADV WILL BE LOW
END FOR THE MOST PART WITH GUSTS OF 40 MPH POSSIBLE...SUSPECT
HIGHER GUSTS MAY BE ISOLATED IN AREAL COVERAGE.
LAKE EFFECT...LATEST RUC ANALYSIS SHOWS 85H TEMPS AT -10C ACROSS LAKE
SUPERIOR SO LAKE SFC/85H TEMP DELTA T IS NEAR EMPIRICAL THRESHOLD
FOR INCREASING LAKE INDUCED CONVECTION. FCST STILL PUSHES 85H
THERMAL TROUGH OVER LAKE IN NEXT 24 HRS SO WILL MAINTAIN LES
WARNING. SPATIAL AND TEMPORAL TRENDS IN LAKE SNOW PARAMETER
SUGGESTS ACTIVITY SHOULD INCREASE SIGNIFICANTLY THIS AFTERNOON AND
CONTINUE OVERNIGHT.
&&
.PREV DISCUSSION... /ISSUED 700 AM CST SUN JAN 1 2012/
AVIATION...01012Z ISSUANCE...
VLIFR IN SCATTERED SNOW SHOWERS ALONG THE WISCONSIN SOUTH SHORE
FROM BAYFIELD PENINSULA EAST AND INLAND ABOUT 30 MILES. ELSEWHERE
MVFR IN COLD ADVECTION CLOUDS AND ISOLATED FLURRIES GOES BACK TO
THE RED RIVER VALLEY AND WILL PERSIST ACROSS MOST OF THE AREA INTO
THE EVENING. VFR IN LIFTING AND SCATTERING CLOUDS FROM WEST TO
EAST LATE TONIGHT.
PREV DISCUSSION... /ISSUED 426 AM CST SUN JAN 1 2012/
SHORT TERM...LATEST KDLH RADAR IMAGERY SHOWS THE SYNOPTICALLY
FORCED SNOW WINDING DOWN ACROSS THE NORTHLAND EARLY THIS
MORNING...WITH THE COLD FRONT NOW EAST OF OUR CWA. WINDS HAVE
TURNED OUT OF THE WEST/NORTHWEST AND HAVE STRENGTHEN ACROSS MOST
OF OUR FCST AREA. THIS TREND WILL CONTINUE TODAY AS MIXING
INCREASES CREATING BLUSTERY CONDITIONS. BECAUSE THE SNOW IS COMING
TO AN END...WE HAVE CANCELLED MANY OF THE WINTER WEATHER
ADVISORIES AND WARNINGS. HOWEVER BECAUSE OF THE STRENGTHENING
WINDS...WE HAVE ISSUED A WIND ADVISORY ALONG AND SOUTH OF THE
HIGHWAY 2 CORRIDOR. THE ADVISORY MAY NEED TO BE EXPANDED NORTHWARD
IF OBSERVATIONS WARRANT. HOWEVER THE MAIN FORECAST CONCERN FOR
THE SHORT TERM WILL BE THE POTENTIAL FOR LAKE EFFECT SNOW ALONG
THE SOUTHSHORE THROUGH MONDAY. NWP MODEL GUIDANCE CONTINUES TO
SUGGEST AN ADDITIONAL 6 TO 12 INCHES OF SNOW ACCUMULATION IS
POSSIBLE...WITH THE HEAVIER AMOUNTS ACROSS THE GOGEBIC RANGE.
THEREFORE WILL KEEP THE WARNING GOING FOR BAYFIELD...ASHLAND AND
IRON COUNTIES UNTIL 6PM MONDAY. BECAUSE OF THE STRONG WINDS...WE
WILL ALSO MENTION THE POSSIBILITY OF BLOWING SNOW. ELSEWHERE
CONDITIONS WILL BE MAINLY DRY ALTHOUGH COLD.
LONG TERM...MONDAY NIGHT THROUGH NEXT SUNDAY.
THE SEVERAL-MONTH-OLD PATTERN OF A DEEP AND STRONG PACIFIC FLOW
ACROSS THE NORTHERN HALF OF THE UNITED STATES AND THE SOUTHERN
HALF OF CANADA WILL CONTINUE THROUGH THE WEEK AND COMING WEEKEND.
STRONG WARM AND DRY CHINOOKS WILL PERIODICALLY DEVELOP OVER THE
CENTRAL CANADIAN THROUGH THE MONTANA ROCKIES AND SPREAD ACROSS OUR
AREA... BRINGING SPRING LIKE WARMTH AND A DRY COLUMN. THE CURRENT
INTERRUPTION...COLD WEATHER WITHIN THE SEASONAL RANGE...THROUGH
TUESDAY...WILL BE FOLLOWED BY ABOVE FREEZING AFTERNOONS WEDNESDAY
THROUGH FRIDAY...WITH TEMPERATURES REMAINING IN THE 20S ACROSS THE
ENTIRE AREA THURSDAY NIGHT. A TEMPORARY SHOT OF LOWER TEMPERATURES
WILL FOLLOW THIS COMING WEEKEND. LITTLE IF ANY PRECIPITATION WILL
FALL DURING THIS PERIOD.
AVIATION...
MODERATE SNOW MOVING ACROSS NW WI AT FCST TIME. THE
WEST EDGE OF SNOW SHOULD CLEAR HYR BY 00Z. T THE OTHER TAF
SITES...MVFR TO IFR CIGS WITH MVFR VSBYS WILL BE COMMON TONIGHT
AND SUNDAY MORNING. ALSO...WINDS WILL INCREASE OVERNIGHT TO 20-30
MPH OUT OF THE NORTHWEST. THE HIGH WINDS WILL REMAIN ACROSS THE
AREA BEFORE TAPERING OFF LATE SUNDAY.
&&
.POINT TEMPS/POPS...
DLH 27 3 13 -4 / 60 10 0 0
INL 28 0 8 -12 / 60 20 0 0
BRD 26 6 16 1 / 60 10 0 0
HYR 27 7 14 -11 / 50 30 10 0
ASX 29 10 16 -3 / 70 60 40 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WIND ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR MNZ033>038.
WI...WIND ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR WIZ001-006>009.
WINTER STORM WARNING UNTIL 6 PM CST MONDAY FOR WIZ002>004.
LS...GALE WARNING UNTIL 4 PM CST MONDAY FOR LSZ121-140>148.
&&
$$
SHORT TERM...CANNON
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
405 PM EST Sun Jan 1 2012
...Significant freeze events developing for Monday and Tuesday
nights...
.SYNOPSIS...
20Z water vapor and H4 RUC analysis shows an amplifying upper level
pattern across the CONUS this afternoon with longwave ridging across
the west and longwave troughing across the east. The main feature
for our forecast will be the longwave trough digging into the
eastern half of the nation, and its evolution over the next 24 to 36
hours. Shortwave energy dropping out of central Canada tonight into
Monday will act to further amplify/sharpen this trough and help
propel a significant arctic cold front through our forecast area.
At the surface,
A cold front currently crossing central/southern AL will enter our
far western zones during the next hour or so, and then quickly cross
the forecast area this evening. Just a few sprinkles seen on
regional radar along this front, however this activity is fighting
and losing the battle against a fairly dry atmospheric column seen
in this morning`s KTLH sounding profile. Temperatures are very
pleasant this afternoon with the forecast area situated within the
thermal ridge ahead of the surface trough. Most locations have
reached the middle to even upper 70s this afternoon...although
locations along the immediate coast of Apalachee Bay are holding in
the 60s with the flow off the relatively cooler shelf waters.
&&
.SHORT TERM (Tonight through Tuesday Night)...
Tonight,
The cold front will move south of the forecast area during the
overnight hours with skies clearing from NW to SE. Still just a
slight chance of a few isolated sprinkles along the frontal boundary
itself...however moisture is really lacking to support measurable
rainfall. The last of these sprinkles should be exiting south of
Cross City by midnight. Thereafter, a cooler and drier airmass will
be arriving on NW flow. Not expecting any freezing temperatures
overnight. Low temperatures by sunrise will range from the mid/upper
30s north of the I-10 corridor, to the mid 40s along the coast and
down across the SE FL Big Bend zones. For those far northern zones
that do reach the middle 30s, the gradient will remain tight enough,
and the dewpoint depressions will be large enough to likely prevent
any frost potential.
Monday/Monday Night,
A dry and cool day on tap with abundant sunshine. We will be saying
goodbye to the 70s as the new post-frontal airmass only supports
high temperatures in the middle/upper 50s. Aloft, the mid/upper
level trough will continue to amplify through the day. A strong
shortwave impulse shown by the ECMWF/GFS will round the base of this
trough Monday evening pushing an arctic cold front through the
region. This secondary front will deliver a significant surge of
cold air to the region (likely the coldest air most of us have seen
so far this winter). The arriving airmass is really quite impressive
for this part of the country. The GFS is showing 850mb temps over
the area down to between -6C to -10C by sunrise Tuesday, and the
ECMWF is between -8 to -13C. The true arctic nature of this airmass
can be seen in the profile below 850mb where temps of -6C to -9C are
progged down to 925 and below. Have issued a freeze watch for the
entire forecast area Monday night with the anticipation of low
temperatures by sunrise in the middle 20s inland and upper 20s to
around 30 at the coast. In addition, NW winds will drop wind chills
down into the upper teens. Confidence is increasing that wind chill
advisories will become necessary with future forecast packages.
Tuesday/Tuesday night,
Arctic airmass will be fully entrenched across the forecast area.
Will see significant recovery of the temps at 850mb, however both
ECMWF/GFS show much slower recovery below this level (which again
shows the arctic nature of the airmass). This trend eventually ends
up with an inverted low level profile by the afternoon hours. This
profile will significantly hinder diurnal mixing, and Tuesday is
going to end up a COLD day. With morning CAA and the low sun angle,
would not be surprised to see some of our northern zones stay below
freezing into the later morning hours. Even after midday, high
temps are likely to struggle into the lower 40s north, and middle
40s south. Have undercut the MAV numbers by several degrees as
statistical guidance often has difficulty with the true degree of
shallow arctic air. In fact, would also not be surprised if a few
spots up toward Albany and Tifton struggle to get out to the 30s.
Add in a NW wind and wind chill values are likely to remain in the
mid 30s to near 40 for much of the day. Surface high pressure will
then settle directly overhead Tuesday night. This high position
along with very dry low level air...a cold start to the evening and
long nights will set up excellent radiational cooling conditions. A
long duration, widespread freeze (and likely hard freeze) seems
probable. Once again have undercut the MAV numbers by a few degrees.
Temperatures inland are forecast to reach the upper teens/low 20s,
with middle to upper 20s for the immediate coast and for more
urbanized inland centers (like downtown Tallahassee).
&&
.LONG TERM (Wednesday through next Sunday)...
The large scale upper level pattern will continue to be anchored by
a negative anomaly over Alaska and a large positive anomaly across
the eastern Pacific, and will evolve toward a mean trough extending
from Hudson Bay to the southwest U.S., and another over the western
Atlantic. A very vigorous short wave will be moving rapidly eastward
away from the east coast Tuesday night and Wednesday, to be followed
by another much weaker one on Thursday. The upper level flow then
rapidly flattens out across the eastern U.S. by the end of the week,
in between the mean troughs over the southwest U.S. and the western
Atlantic. A weak short wave is forecast to move rapidly eastward
across the southeast U.S. on Saturday, bringing increased clouds and
possibly a few showers. Think the GFS overdoes the moisture
associated with this weak system, and prefer the drier Euro
solution. Temperatures will start out much below normal, with a hard
freeze likely for most areas Wednesday morning, as a cold dry
airmass remains centered over the southeast. After another frosty
morning Thursday, temperatures will begin to moderate steadily.
Heights will rise across the southeast in response to a strong short
wave dropping into the bottom of the mean trough over the southwest,
while the low level flow becomes more southerly as surface high
pressure weakens and moves into the western Atlantic. By the
weekend, temperatures will rise to above normal most areas. A weak
front is forecast to lie somewhere near or just north of the
Tri-State Area by Saturday. Prefer the EURO solution keeping the
front to the north of the area through the weekend, because the GFS
looks too fast and progressive with the next short wave , given the
expected mean trough position over the southwest.
&&
.MARINE...
Northwest and northerly winds will increase to advisory levels from
west to east this evening behind a passing cold front. These winds
will build the seas to cautionary levels over the nearshore legs,
and advisory levels offshore by Monday morning. Winds may briefly
drop below advisory levels for a period Monday afternoon, but will
increase once again Monday evening with the passage of a secondary
cold front. High end advisory conditions are expected Monday night
into early Tuesday, with a period of near gale force gusts becoming
more likely. Winds and seas will then gradually diminish Tuesday
afternoon and night as high pressure builds over the Northeast Gulf
of Mexico.
&&
.AVIATION (through 18Z Monday)...
A very sharp and dry cold front is moving rapidly southeast through
central Alabama. Southwest winds with gusts up to 20kts is occurring
ahead of the front. Behind the front winds are 15kts gusting to
20-26kts. CIGS have risen to VFR across Southeast Alabama and the
Florida Panhandle/Big Bend at KDHN, KECP and KTLH. Further east,
KABY and KVLD just now climbed out of IFR to VFR/MVFR levels.
Expect periods of CIGS around 5 to 6kft ahead of the cold front this
afternoon. This evening, the cold front will clear the clouds out
with gusty northwesterly winds that taper off overnight. Tomorrow
afternoon, strong gusty winds from the northwest will reappear by
late morning.
&&
.FIRE WEATHER...
A cold front will cross the forecast area this evening bringing a
cooler and drier airmass in its wake. Relative humidity values will
drop into the upper teens to middle 20s across the area during
Monday afternoon, along with gusty northwest winds. A secondary
arctic cold front will cross the area Monday evening delivering even
colder and drier air for Tuesday. Those with outdoor activities
planned for early Tuesday morning should anticipate widespread
sub-freezing temperatures, with wind chill values in the teens. Wind
chill values are likely to not climb out of the 30s Tuesday
afternoon over much of the area. Despite high temperatures only in
the lower to middle 40s on Tuesday, very dry low level air will
still allow relative humidity values to fall into the middle and
upper teens for much of the region. Another long duration and
widespread freeze or hard freeze is anticipated for Tuesday night
into Wednesday morning.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 42 57 26 46 19 / 20 0 0 0 0
Panama City 43 58 32 48 28 / 20 0 0 0 0
Dothan 39 56 27 45 23 / 10 0 0 0 0
Albany 38 56 25 43 20 / 20 0 0 0 0
Valdosta 40 56 25 45 19 / 20 0 0 0 0
Cross City 43 59 27 47 18 / 20 0 0 0 0
Apalachicola 43 58 30 48 24 / 20 0 0 0 0
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
AL...Freeze Watch from late Monday night through Tuesday morning for
Coffee-Dale-Geneva-Henry-Houston.
Fire Weather Watch from Monday morning through Monday afternoon
for Coffee-Dale-Geneva-Henry-Houston.
GA...Freeze Watch from late Monday night through Tuesday morning for
Baker-Ben Hill-Berrien-Brooks-Calhoun-Clay-Colquitt-Cook-
Decatur-Dougherty-Early-Grady-Irwin-Lanier-Lee-Lowndes-
Miller-Mitchell-Quitman-Randolph-Seminole-Terrell-Thomas-
Tift-Turner-Worth.
Fire Weather Watch Monday afternoon for Baker-Ben Hill-Berrien-
Brooks-Calhoun-Clay-Colquitt-Cook-Decatur-Dougherty-Early-
Grady-Irwin-Lanier-Lee-Lowndes-Miller-Mitchell-Quitman-
Randolph-Seminole-Terrell-Thomas-Tift-Turner-Worth.
FL...Freeze Watch from late Monday night through Tuesday morning for
Calhoun-Central Walton-Coastal Bay-Coastal Dixie-Coastal
Franklin-Coastal Gulf-Coastal Jefferson-Coastal Taylor-
Coastal Wakulla-Gadsden-Holmes-Inland Bay-Inland Dixie-
Inland Franklin-Inland Gulf-Inland Jefferson-Inland Taylor-
Inland Wakulla-Inland Walton-Jackson-Lafayette-Leon-Liberty-
Madison-South Walton-Washington.
Fire Weather Watch Monday afternoon for Calhoun-Central Walton-
Coastal Bay-Coastal Dixie-Coastal Franklin-Coastal Gulf-
Coastal Jefferson-Coastal Taylor-Coastal Wakulla-Gadsden-
Holmes-Inland Bay-Inland Dixie-Inland Franklin-Inland Gulf-
Inland Jefferson-Inland Taylor-Inland Wakulla-Inland Walton-
Jackson-Lafayette-Leon-Liberty-Madison-South Walton-
Washington.
GM...Small Craft Advisory from 7 PM this evening to 10 AM EST Tuesday
for Apalachee Bay-Coastal waters From Ochlockonee River to
Apalachicola FL out to 20 NM-Coastal waters from Suwannee
River to Keaton Beach FL out 20 NM-Coastal waters from
Apalachicola to Destin FL out 20 NM-Waters from Suwannee
River to Apalachicola FL from 20 to 60 NM-Waters from
Apalachicola to Destin FL from 20 to 60 NM.
&&
$$
SYNOPSIS/SHORT TERM/MARINE...MROCZKA
AVIATION/FIRE WEATHER...LANIER/MROCZKA
LONG TERM...DUVAL
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1124 AM CST SUN JAN 1 2012
.DISCUSSION...
ISSUED 1020 AM CST SUN JAN 1 2012
COLD FRONT IS APPROACHING THE INDIANA/OHIO BORDER LATE THIS
MORNING. TRAILING STRATOCUMULUS DECK IS QUICKLY PUSHING THROUGH
THE CWA...AND IS CURRENTLY MAINLY CLEAR WEST OF I-57. REMAINING
CLOUD COVER FROM THIS DECK WILL MOVE OUT SHORTLY. HOWEVER...SOME
MORE DIURNAL CUMULUS IS QUICKLY DROPPING SOUTH OUT OF
WISCONSIN/NORTHEAST IOWA. AREAS NORTH OF I-74 MOST LIKELY TO BE
IMPACTED BY THOSE CLOUDS BY EARLY AFTERNOON. SOME SNOW SHOWERS
CURRENTLY APPEARING ON RADAR MOSAICS ACROSS WESTERN WISCONSIN.
LATEST HRRR APPEARS TO HAVE A GOOD HANDLE ON IT...AND TRACKS THESE
JUST TO OUR NORTHEAST THIS AFTERNOON...SO WILL NOT ADD ANY TO OUR
GRIDS AT THIS TIME. HOWEVER...CANNOT RULE OUT A STRAY FLURRY.
HAVE KEPT WIND ADVISORY GOING...ALTHOUGH WE ARE SEEING A FEW LULLS
IN SOME AREAS AT THE MOMENT. BUFKIT MOMENTUM TRANSFER OFF THE
LATEST NAM STILL SHOWING AROUND 45 KNOTS AROUND 900 MB...WHICH
SHOULD BE MIXED DOWN WITH THE ABUNDANT SUNSHINE. WITH THIS
SUNSHINE...HAVE UPDATED HOURLY TEMPERATURE TRENDS TO KEEP THINGS
STEADY OR RISING A COUPLE DEGREES THROUGH MIDDAY...BEFORE FALLING
THIS AFTERNOON AS 850 MB TEMPERATURES DROP TO NEAR -10C ACROSS THE
NORTHERN CWA.
UPDATED ZONES/GRIDS HAVE BEEN SENT.
GEELHART
&&
.AVIATION...
ISSUED 1123 AM CST SUN JAN 1 2012
LINGERING MVFR CEILINGS AT KCMI HAVE MOVED EASTWARD. WILL SEE A
COUPLE MORE HOURS OF CLEAR SKIES AT MOST OF THE TAF SITES...BEFORE
AN AREA OF CEILINGS AROUND 4000 FEET DROPS SOUTHWARD. AWIPS
TIME-OF-ARRIVAL TOOL HAS THIS ARRIVING FROM KPIA-KCMI IN THE 21Z
TIME FRAME. CYCLONIC CIRCULATION OVER THE GREAT LAKES WILL KEEP
PERIODS OF VFR CEILINGS LINGERING INTO MONDAY IN THESE
AREAS...WITH MAINLY SCATTERED CLOUDS FURTHER SOUTH. WIND-WISE...
STILL WILL SEE SOME 30-40 KNOT WIND GUSTS FOR A FEW MORE
HOURS...BEFORE SOME DIMINISHING TAKES PLACE LATER THIS AFTERNOON
AND OVERNIGHT. HOWEVER...WE WILL LIKELY SEE GUSTS AGAIN OVER 30
KNOTS ON MONDAY MORNING.
GEELHART
&&
.PREV DISCUSSION...
ISSUED 325 AM CST SUN JAN 1 2012
BIGGEST FORECAST CONCERN IS HOW STRONG WINDS GET TODAY AND HOW
LONG TO HAVE WIND ADVISORY. STRONG WINDS TODAY DUE TO 1000 MB LOW
PRESSURE OVER FAR NW IL DEEPENS AS IT MOVES NE ACROSS THE CENTRAL
GREAT LAKES REGION AND INTO FAR EASTERN ONTARIO BY 00Z/6 PM. MUCH
COLDER AIR TO USHER INTO IL ON STRONG WNW BEHIND A COLD FRONT
TODAY. 00Z MODELS ARE IN FAIR AGREEMENT NEXT FEW DAYS AND USED A
BLEND. QUIET WEATHER EXPECTED FROM TONIGHT THROUGH FRIDAY AS COLD
TEMPERATURES EARLY THIS WEEK MODERATE BACK ABOVE NORMAL DURING THE
SECOND HALF OF THE WORK WEEK.
SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
09Z/3 AM SURFACE MAP SHOWS 1000 MB LOW PRESSURE OVER FAR NW IL
WITH ITS COLD FRONT THROUGH WESTERN IL INTO SE MO AND EASTERN AR.
SSW WINDS AHEAD OF COLD FRONT TURN WNW BEHIND THE FRONT. WIND
GUSTS AHEAD OF COLD FRONT GENERALLY 20 TO 32 MPH AND INCREASE TO
25 TO 37 MPH BEHIND THE COLD FRONT. NARROW BAND OF POST FRONTAL RAIN
SHOWERS NEAR THE IA/IL MS RIVER BORDER AND A FEW MORE RAIN SHOWERS
BETWEEN ST LOUIS AND JACKSONVILLE MOVING EAST. MILD TEMPS IN THE
40S OVER CENTRAL AND SE IL EARLY THIS MORNING. DEWPOINTS WERE IN
THE MID TO UPPER 30S. WILL CARRY A 20-40% CHANCE OF RAIN SHOWERS
OVER CENTRAL IL THIS MORNING AND COULD MIX WITH LIGHT SNOW BUT NO
ACCUMULATIONS. KEEPING IN DRY IN FAR SE IL BY LAWRENCEVILLE TODAY.
MODELS SWEEP COLD FRONT QUICKLY EAST TOWARD THE IL/IN BORDER BY
12Z/6 AM THIS MORNING WITH 1000 MB LOW PRESSURE OVER NW IL
DEEPENING NE TO 995 MB OVER FAR NW LOWER MI BY 18Z/NOON AND TO 990
MB OVER FAR EASTERN ONTARIO BY 00Z/6 PM. MEANWHILE 1037 MB HIGH
PRESSURE OVER THE ROCKIES TO STRENGTHEN TO 1042 MB INTO THE HIGH
PLAINS BY EARLY EVENING. THIS TO GENERATE A VERY TIGHT PRESSURE
GRADIENT OVER IL BEHIND THE COLD FRONT TODAY WITH MIXING UP TO
5-6K FT AS SKIES BECOME PARTLY TO MOSTLY SUNNY FOR A TIME AND WNW
WINDS OF 20 TO 30 MPH AND GUSTS OF 40 TO 50 MPH FROM LATE MORNING
INTO THE AFTERNOON. EARLY MORNING HIGHS TO RANGE FROM THE UPPER
30S AND LOWER 40S...WITH MID 40S ALONG THE WABASH RIVER. TEMPS
COOL INTO THE LOW TO MID 30S BY SUPPER TIME TODAY.
WILL CONTINUE THE WIND ADVISORY TODAY AND THIS EVENING ACROSS
CENTRAL AND SE IL WITH STRONGEST WINDS EXPECTED LATE MORNING AND
AFTERNOON. INCREASED WIND SPEEDS MONDAY WITH PRESSURE GRADIENT
REMAINING QUITE STRONG WITH WINDS GUSTS OF 30 TO 40 MPH EXPECTED.
ALSO INCREASE CLOUD COVER ESPECIALLY OVER EASTERN IL WITH STRONG
UPPER LEVEL TROF DIGGING OVER THE EASTERN STATES LATE TONIGHT AND
MONDAY AND THEN SHIFTING EASTWARD MONDAY NIGHT AS SURFACE RIDGE
SETTLES EAST INTO THE MS RIVER VALLEY BY DAWN TUE. LOW CLOUDS AND
WINDS TO DECREASE FROM WEST TO EAST DURING MONDAY NIGHT. LOWS
TONIGHT MOSTLY IN THE LOWER 20S WITH SUBFREEZING HIGHS MON OF 25
TO 30F. LOWS MONDAY NIGHT IN THE LOW TO MID TEENS WITH SUBFREEZING
HIGHS AGAIN ON TUE IN THE UPPER 20S TO AROUND 30F. HIGH PRESSURE
RIDGE SHIFTING EAST OF IL BY TUE EVENING TO START MODERATING TEMPS
WITH SOUTHERLY FLOW SETTING UP FOR A FEW DAYS. A NORTHERN STREAM
SHORT WAVE TO MOVE ACROSS NORTHERN IL OVERNIGHT TUE NIGHT KEEPING
ITS LIGHT PRECIPITATION AND MORE CLOUDS NORTH IN THE GREAT LAKES
REGION. MOSTLY SUNNY SKIES EXPECTED TUE AND WED WITH HIGHS
MODERATING ABOUT 10 DEGREES TO UPPER 30S AND LOWER 40S WED.
LONG TERM...THURSDAY THROUGH SATURDAY NIGHT
DRY CONDITIONS GENERALLY EXPECTED LATE THIS WEEK WITH ABOVE NORMAL
TEMPERATURES WITH MILDEST READINGS ON FRIDAY WITH LOWER 50S. THIS
DUE TO UPPER LEVEL RIDGING INTO THE MS VALLEY AND WEATHER
DISTURBANCES PASSING NORTH OF IL ALONG THE US/CANADIAN BORDER AND
SOUTH OF IL TOO IN A SPLIT UPPER LEVEL FLOW.
HUETTL
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR ILZ027>031-036>038-
040>057-061>063-066>068-071>073.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1021 AM CST SUN JAN 1 2012
.DISCUSSION...
ISSUED 1020 AM CST SUN JAN 1 2012
COLD FRONT IS APPROACHING THE INDIANA/OHIO BORDER LATE THIS
MORNING. TRAILING STRATOCUMULUS DECK IS QUICKLY PUSHING THROUGH
THE CWA...AND IS CURRENTLY MAINLY CLEAR WEST OF I-57. REMAINING
CLOUD COVER FROM THIS DECK WILL MOVE OUT SHORTLY. HOWEVER...SOME
MORE DIURNAL CUMULUS IS QUICKLY DROPPING SOUTH OUT OF
WISCONSIN/NORTHEAST IOWA. AREAS NORTH OF I-74 MOST LIKELY TO BE
IMPACTED BY THOSE CLOUDS BY EARLY AFTERNOON. SOME SNOW SHOWERS
CURRENTLY APPEARING ON RADAR MOSAICS ACROSS WESTERN WISCONSIN.
LATEST HRRR APPEARS TO HAVE A GOOD HANDLE ON IT...AND TRACKS THESE
JUST TO OUR NORTHEAST THIS AFTERNOON...SO WILL NOT ADD ANY TO OUR
GRIDS AT THIS TIME. HOWEVER...CANNOT RULE OUT A STRAY FLURRY.
HAVE KEPT WIND ADVISORY GOING...ALTHOUGH WE ARE SEEING A FEW LULLS
IN SOME AREAS AT THE MOMENT. BUFKIT MOMENTUM TRANSFER OFF THE
LATEST NAM STILL SHOWING AROUND 45 KNOTS AROUND 900 MB...WHICH
SHOULD BE MIXED DOWN WITH THE ABUNDANT SUNSHINE. WITH THIS
SUNSHINE...HAVE UPDATED HOURLY TEMPERATURE TRENDS TO KEEP THINGS
STEADY OR RISING A COUPLE DEGREES THROUGH MIDDAY...BEFORE FALLING
THIS AFTERNOON AS 850 MB TEMPERATURES DROP TO NEAR -10C ACROSS THE
NORTHERN CWA.
UPDATED ZONES/GRIDS HAVE BEEN SENT.
GEELHART
&&
.AVIATION...
ISSUED 520 AM CST SUN JAN 1 2012
STRONG WINDS THE MAIN CONCERN THIS FORECAST PERIOD WITH A
SECONDARY CONCERN BEING THE DURATION OF THE MVFR AND LOCAL
IFR CIGS THIS MORNING JUST BEHIND THE COLD FRONT. STRONG
LOW PRESSURE OVER SOUTHEAST WISCONSIN WILL SHIFT WELL OFF
TO OUR EAST TODAY BUT THE TIGHT PRESSURE GRADIENT ASSOCIATED
WITH THE STORM SYSTEM WILL PRODUCE THE GUSTY WEST TO NORTHWEST
WINDS INTO TONIGHT. WIND GUSTS AS HIGH AS 45 KTS WILL BE
POSSIBLE AT TIMES TODAY...WITH ONLY A GRADUAL DECREASE IN
SPEEDS EXPECTED TONIGHT. BASED ON CURRENT TRENDS IN SATELLITE
IT APPEARS THE INITIAL BAND OF MVFR/IFR CIGS WILL PUSH INTO
EAST CENTRAL IL BY 16Z...WITH VFR CONDITIONS INTO EARLY THIS
AFTN...FOLLOWED BY ANOTHER BAND OF LOW VFR CIGS FOR THIS
AFTN AND THIS EVENING AS THE STRONGER PUSH OF COLD AIR SHIFTS
SOUTHEAST INTO OUR AREA. A NARROW BAND OF RAIN WITH A FEW
REPORTS OF SLEET WEST OF PIA WILL TRACK QUICKLY ACRS THE
TAF SITES THIS MORNING. HAVE EVEN HAD SOME LIGHTNING WITH
THE BAND OF SHOWERS PUSHING EAST OF I-57. MOST OF THE PRECIP
SHOULD PUSH EAST OF THE AREA BY 15Z.
SMITH
&&
.PREV DISCUSSION...
ISSUED 325 AM CST SUN JAN 1 2012
BIGGEST FORECAST CONCERN IS HOW STRONG WINDS GET TODAY AND HOW
LONG TO HAVE WIND ADVISORY. STRONG WINDS TODAY DUE TO 1000 MB LOW
PRESSURE OVER FAR NW IL DEEPENS AS IT MOVES NE ACROSS THE CENTRAL
GREAT LAKES REGION AND INTO FAR EASTERN ONTARIO BY 00Z/6 PM. MUCH
COLDER AIR TO USHER INTO IL ON STRONG WNW BEHIND A COLD FRONT
TODAY. 00Z MODELS ARE IN FAIR AGREEMENT NEXT FEW DAYS AND USED A
BLEND. QUIET WEATHER EXPECTED FROM TONIGHT THROUGH FRIDAY AS COLD
TEMPERATURES EARLY THIS WEEK MODERATE BACK ABOVE NORMAL DURING THE
SECOND HALF OF THE WORK WEEK.
SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
09Z/3 AM SURFACE MAP SHOWS 1000 MB LOW PRESSURE OVER FAR NW IL
WITH ITS COLD FRONT THROUGH WESTERN IL INTO SE MO AND EASTERN AR.
SSW WINDS AHEAD OF COLD FRONT TURN WNW BEHIND THE FRONT. WIND
GUSTS AHEAD OF COLD FRONT GENERALLY 20 TO 32 MPH AND INCREASE TO
25 TO 37 MPH BEHIND THE COLD FRONT. NARROW BAND OF POST FRONTAL RAIN
SHOWERS NEAR THE IA/IL MS RIVER BORDER AND A FEW MORE RAIN SHOWERS
BETWEEN ST LOUIS AND JACKSONVILLE MOVING EAST. MILD TEMPS IN THE
40S OVER CENTRAL AND SE IL EARLY THIS MORNING. DEWPOINTS WERE IN
THE MID TO UPPER 30S. WILL CARRY A 20-40% CHANCE OF RAIN SHOWERS
OVER CENTRAL IL THIS MORNING AND COULD MIX WITH LIGHT SNOW BUT NO
ACCUMULATIONS. KEEPING IN DRY IN FAR SE IL BY LAWERNCEVILLE TODAY.
MODELS SWEEP COLD FRONT QUICKLY EAST TOWARD THE IL/IN BORDER BY
12Z/6 AM THIS MORNING WITH 1000 MB LOW PRESSURE OVER NW IL
DEEPENING NE TO 995 MB OVER FAR NW LOWER MI BY 18Z/NOON AND TO 990
MB OVER FAR EASTERN ONTARIO BY 00Z/6 PM. MEANWHILE 1037 MB HIGH
PRESSURE OVER THE ROCKIES TO STRENGHTHEN TO 1042 MB INTO THE HIGH
PLAINS BY EARLY EVENING. THIS TO GENERATE A VERY TIGHT PRESSURE
GRADIENT OVER IL BEHIND THE COLD FRONT TODAY WITH MIXING UP TO
5-6K FT AS SKIES BECOME PARTLY TO MOSTLY SUNNY FOR A TIME AND WNW
WINDS OF 20 TO 30 MPH AND GUSTS OF 40 TO 50 MPH FROM LATE MORNING
INTO THE AFTERNOON. EARLY MORNING HIGHS TO RANGE FROM THE UPPER
30S AND LOWER 40S...WITH MID 40S ALONG THE WABASH RIVER. TEMPS
COOL INTO THE LOW TO MID 30S BY SUPPER TIME TODAY.
WILL CONTINUE THE WIND ADVISORY TODAY AND THIS EVENING ACROSS
CENTRAL AND SE IL WITH STRONGEST WINDS EXPECTED LATE MORNING AND
AFTERNOON. INCREASED WIND SPEEDS MONDAY WITH PRESSURE GRADIENT
REMAINING QUITE STRONG WITH WINDS GUSTS OF 30 TO 40 MPH EXPECTED.
ALSO INCREASE CLOUD COVER ESPECIALLY OVER EASTERN IL WITH STRONG
UPPER LEVEL TROF DIGGING OVER THE EASTERN STATES LATE TONIGHT AND
MONDAY AND THEN SHIFTING EASTWARD MONDAY NIGHT AS SURFACE RIDGE
SETTLES EAST INTO THE MS RIVER VALLEY BY DAWN TUE. LOW CLOUDS AND
WINDS TO DECREASE FROM WEST TO EAST DURING MONDAY NIGHT. LOWS
TONIGHT MOSTLY IN THE LOWER 20S WITH SUBFREEZING HIGHS MON OF 25
TO 30F. LOWS MONDAY NIGHT IN THE LOW TO MID TEENS WITH SUBFREEZING
HIGHS AGAIN ON TUE IN THE UPPER 20S TO AROUND 30F. HIGH PRESSURE
RIDGE SHIFTING EAST OF IL BY TUE EVENING TO START MODERATING TEMPS
WITH SOUTHERLY FLOW SETTING UP FOR A FEW DAYS. A NORTHERN STREAM
SHORT WAVE TO MOVE ACROSS NORTHERN IL OVERNIGHT TUE NIGHT KEEPING
ITS LIGHT PRECIPITATION AND MORE CLOUDS NORTH IN THE GREAT LAKES
REGION. MOSTLY SUNNY SKIES EXPECTED TUE AND WED WITH HIGHS
MODERATING ABOUT 10 DEGREES TO UPPER 30S AND LOWER 40S WED.
LONG TERM...THURSDAY THROUGH SATURDAY NIGHT
DRY CONDITIONS GENERALLY EXPECTED LATE THIS WEEK WITH ABOVE NORMAL
TEMPERATURES WITH MILDEST READINGS ON FRIDAY WITH LOWER 50S. THIS
DUE TO UPPER LEVEL RIDGING INTO THE MS VALLEY AND WEATHER
DISTURBANCES PASSING NORTH OF IL ALONG THE US/CANADIAN BORDER AND
SOUTH OF IL TOO IN A SPLIT UPPER LEVEL FLOW.
HUETTL
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR ILZ027>031-036>038-
040>057-061>063-066>068-071>073.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1112 AM CST SUN JAN 1 2012
.UPDATE...
STRONG SHORT WAVE OVER MN IN CYCLONIC FLOW ALOFT...AS SEEN ON WATER
VAPOR...DROPPING ACROSS THE AREA THIS AFTERNOON SUPPORTS POTENTIAL
FOR FLURRIES OVER NORTHERN PORTIONS OF THE CWFA THROUGH 00Z.
WITH RESPECT TO WINDS...PEAK MIXING ONGOING NOW. MAIN QUESTION FOR
THE AFTERNOON AND EVENING WILL BE DURATION OF STRONG WINDS. NAM
AND RUC TROP PRESSURE FIELDS INDICATE TROP FOLD TO CROSS NORTHERN
ILLINOIS THIS AFTERNOON AND PEAK WINDS EXPECTED IN NORTHWEST
ILLINOIS COUNTIES BETWEEN 18Z AND 22Z. CURRENT THINKING IS THAT
WHILE SUSTAINED WINDS CONTINUE...ENCROACHING CLOUDS WILL TEMPER
MIXING AND THUS THE INTENSITY OF THE GUSTS BY LATE AFTERNOON AND
SIMILARLY WITH THE LOSS OF HEATING THIS EVENING.
WIND HEADLINES WILL CONTINUE FOR THE AFTERNOON WITH ADJUSTMENTS
POSSIBLE FOR THIS EVENING AND OVERNIGHT DEPENDING ON HOW THE
AFTERNOON EVOLVES.
&&
.AVIATION...
A STRONG STORM SYSTEM CROSSING THE MIDWEST HAS LIFTED INTO THE
GREAT LAKES. IN ITS WAKE...STRONG NORTHWESTERLY LOW LEVEL WINDS
ARE BATTERING THE ENTIRE UPPER MIDWEST. IN EASTERN IOWA AND
WESTERN ILLINOIS...SUSTAINED WINDS OF 30 TO 40 MPH WILL CONTINUE THROUGH
THE DAY WITH PEAK WINDS EXPECTED TO OCCUR THIS AFTERNOON WITH
GUSTS IN SOME SPOTS TOPPING 50 MPH. GUSTS WILL DIMINISH AFTER
SUNSET...ALTHOUGH SUSTAINED WINDS WILL REMAIN HIGH THROUGH THE
NIGHT AND BEGIN TO GRADUALLY DIMINISH MONDAY. WITH DAYTIME HEATING...WIND
GUSTS WILL RETURN MONDAY ALTHOUGH NOT AS STRONG AS TODAY.
OTHERWISE...AN AREA OF MVFR CIGS WILL OVERSPREAD THE AREA FROM
THE NORTH THIS AFTERNOON AND LINGER INTO THE EVENING BEFORE
SHIFTING OFF TO THE EAST OVERNIGHT.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...WIND ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR CLINTON-DES MOINES-
JACKSON-LEE-SCOTT.
HIGH WIND WARNING UNTIL MIDNIGHT CST TONIGHT FOR BENTON-BUCHANAN-
CEDAR-DELAWARE-DUBUQUE-HENRY IA-IOWA-JEFFERSON-JOHNSON-
JONES-KEOKUK-LINN-LOUISA-MUSCATINE-VAN BUREN-WASHINGTON.
IL...WIND ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR BUREAU-CARROLL-
HANCOCK-HENDERSON-HENRY IL-JO DAVIESS-MCDONOUGH-MERCER-
PUTNAM-ROCK ISLAND-STEPHENSON-WARREN-WHITESIDE.
MO...WIND ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR CLARK-SCOTLAND.
&&
$$
DMD/SHEETS/DMD
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1159 AM EST SUN JAN 1 2012
.SYNOPSIS...
HIGH PRESSURE WILL BUILD BRIEFLY ACROSS THE REGION TODAY. AN OCCLUDED
FRONT WILL APPROACH FROM THE WEST THIS EVENING AND CROSS THE
REGION EARLY MONDAY MORNING...FOLLOWED BY A STRONG ARCTIC FRONT
LATE MONDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...LOW CLOUDS ARE HANGING TOUGH ACROSS MUCH OF THE FORECAST
AREA...AND IN FACT STRATOCUMULUS HAVE REDEVELOPED ACROSS PORTIONS
OF DOWNEAST MAINE THAT HAD CLEARED EARLIER. HAVE THEREFORE
INCREASED CLOUD COVER THROUGH MUCH OF THIS AFTERNOON AND THEN
BEGIN TO CLEAR THINGS OUT LATE. OTHERWISE NO OTHER CHANGES NEEDED.
PREVIOUS DISCUSSION...CLOUDS HANGING ON ACROSS MUCH OF
THE CWA THIS MORNING AS EVIDENT FROM THE LATEST IR SATL IMAGERY.
MOISTURE HANGING ON BELOW 925MBS W/AIRMASS DRY ABOVE THIS LAYER.
INVERSION IS IN PLACE AND IS SHOWN TO HANG ON FOR A WHILE THIS
MORNING PER THE LATEST RUC SOUNDINGS WHICH IS SUPPORT BY THE 00Z
NAM. A W FLOW TAKES OVER LATER THIS MORNING HELPING TO ERODE
CLOUDS ACROSS THE CENTRAL AND DOWNEAST REGION. ACROSS THE NORTH
AND WEST, CLOUDS COULD HANG ON LONGER W/INVERSION HANGING AS SHOWN
BY THE SOUNDINGS SHOWING MOISTURE STAYING TRAPPED AT AROUND
900MBS. DECIDED TO HANG ON TO SOME CLOUDS LONGER ACROSS THE
NORTHERN AND WESTERN AREAS INTO EARLY AFTERNOON W/MORE SUN ACROSS
THE CENTRAL AND DOWNEAST AREAS. OBVIOUSLY THIS WILL PLAY INTO THE
MAX TEMPERATURE FCST TODAY. ADJUSTED THE DAYCREW/S MAXES FOR TODAY
UPWARD ACROSS THE CWA W/UPPER 20S TO LOWER 30S ACROSS THE NORTH
AND WEST AND UPPER 30S TO LOWER 40S FOR CENTRAL AND DOWNEAST
AREAS.
TONIGHT COULD BE INTERESTING AS AN OCCLUDED FRONT APCHS FROM THE W
LATER TONIGHT W/PRECIP MOVING IN LATER TONIGHT. LATEST MDL
SOUNDINGS SHOW TEMPERATURES TO BE WARM ENOUGH ACROSS THE CENTRAL
AND DOWNEAST AREAS FOR MAINLY RAIN. ACROSS THE NORTHERN AND
WESTERN AREAS, THINGS LOOK TO BE DIFFERENT AS TEMPERATURES COOL
OFF EARLY TONIGHT AND THEN LEVEL OFF BEFORE RISING WELL AFTER
MIDNIGHT. WX ELEMENT IN THESE AREAS WILL BE IN THE FORM OF SOME
SNOW BUT A TRANSITION TO FREEZING PRECIP IS POSSIBLE. THE NAM AND GFS
BOTH SHOW A WARM LAYER SETTING UP AGAIN FROM 925-850MBS W/A COLD
LAYER AT THE SFC. THIS WILL SET THE STAGE FOR ANOTHER FRZA EVENT.
THE TIMING LOOKS TO BE BRIEF W/FZRA/FZDZ. THERE ALSO LOOKS TO BE A
PERIOD OF SLEET POSSIBLE. BEST SNOW ACCUMULATION WILL BE ACROSS
THE FAR NORTH AND WEST MAINLY NORTH AND WEST OF CAR,PQI & HUL. THE
PRECIP FROM THICKNESS TOOL WAS USED FOR THE WX ELEMENT. QPF IS A
BLEND OF HPC/GFS AND THE NAM WHICH SHOWS THE HIGHEST AREAS ACROSS
DOWNEAST AND AND EASTERN SECTIONS. ADDED SOME ICE ACCUMULATION
MAINLY FOR THE NORTH AND WEST W/<.10". DECIDED TO HOLD OFF ON ANY
WINTER WEATHER ADVISORIES AS THIS LOOKS TO BE LATE 2ND PERIOD INTO
THE 3RD PERIOD. THE DAYCREW CAN ASSESS THIS FURTHER W/LATER MODEL
RUNS. THE HWO WILL ADDRESS THIS POTENTIAL.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
THE OCCLUDED FRONT MOVES EAST EARLY MONDAY MORNING WITH STEADY
PRECIPITATION ENDING EARLY. EXPECT MAX TEMPERATURES TO OCCUR EARLY
IN THE DAY BEFORE FALLING A FEW DEGREES DURING THE AFTERNOON AS
SLIGHTLY COOLER FILTERS IN BEHIND THE OCCLUSION. ONCE THE STEADY
PRECIPITATION ENDS MONDAY MORNING IT WILL REMAIN MOSTLY CLOUDY. AN
ARCTIC COLD FRONT WILL APPROACH LATER MONDAY AFTERNOON AND THEN
SWEEP EAST ACROSS THE FA MONDAY NIGHT. THERE WILL BE THE CHANCE
FOR SNOW SHOWERS ACROSS NORTHERN PORTIONS OF THE FA WITH THE
PASSAGE OF THE ARCTIC BOUNDARY...HOWEVER THE BIG STORY WILL BE
THE STRONG COLD ADVECTION LATER MONDAY NIGHT AND TUESDAY.
TEMPERATURES WILL FALL TO ZERO TO 5 ABOVE ZERO ACROSS MUCH OF
NORTHERN MAINE AND LOW TO MID TEENS ACROSS MOST OF DOWNEAST MAINE
BY EARLY TUESDAY MORNING. TEMPERATURES ON TUESDAY WILL NOT RECOVER
MUCH FROM THE EARLY MORNING LOWS WITH HIGHS ONLY EXPECTED TO BE IN
THE SINGLE DIGITS ABOVE ZERO TO AROUND 10 ABOVE NORTH AND 15 TO 20
DOWNEAST. ALONG WITH THE COLD TEMPERATURES WILL COME THE CHANCE
FOR SOME SNOW SHOWERS OR FLURRIES ACROSS THE NORTH WITH PARTLY
CLOUDY SKIES DOWNEAST.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
IT STILL LOOKS RELATIVELY QUIET THROUGH THE LONG TERM WITH NO BIG
STORMS IN SIGHT. TEMPERATURES WILL REMAIN BELOW NORMAL THROUGH
MUCH OF THE PERIOD. BRISK NORTHWEST FLOW WILL CONTINUE TUESDAY
NIGHT AND WEDNESDAY WITH MAINLY DRY CONDITIONS AS HIGH PRESSURE
MOVES EAST. A WEAK DISTURBANCE WILL CROSS THE REGION THURSDAY
FOLLOWED BY HIGH PRESSURE THURSDAY NIGHT. A CLIPPER TYPE SYSTEM
COULD BRING SOME SNOW SHOWERS TO THE REGION BY THE END OF THE
PERIOD.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
NEAR TERM: IFR/MVFR CONDITIONS WILL GO TO VFR LATER THIS MORNING
W/THE NORTHERN TERMINALS HANGING ONTO MVFR CIGS A WHILE LONGER
W/THE INVERSION. VFR THIS EVENING DROPPING BACK TO MVFR LATER
TONIGHT ACROSS THE NORTHERN TERMINALS W/IFR CONDITIONS FOR BGR AND
BHB NEAR OR AFTER 06Z.
SHORT TERM: MVFR CONDITIONS POSSIBLE IN ANY SCATTERED SNOW SHOWERS
MAINLY ACROSS NORTHERN SECTIONS MONDAY AND TUESDAY OTHERWISE
MAINLY VFR.
&&
.MARINE...
NEAR TERM: DECIDED TO GO TO A GALE WARNING STARTING AFTER 06Z AND
CONTINUING INTO MONDAY AS LLVL JET OF 45-50KT HITS THE WATERS.
GUSTS TO HIT 35KTS. WINDS WILL BE TOUGH TO MIX DOWN W/WAA INITIALLY
AND THEN AS THE OCCLUSION MOVES THROUGH SW WINDS WILL HAVE A CHC
TO MIX DOWN AS LLVLS BEGIN TO COOL. DAYCREW/S WAVE HEIGHTS WERE
MATCHING CLOSE THE LATEST SWAN AND WNAWAVE AND DECIDED TO STAY
CLOSE THE CURRENT FCST OF SEAS BUILDING TO 3-6 FT.
SHORT TERM: GALE FORCE CONDITIONS MONDAY INTO MONDAY NIGHT THEN
SCA CONDITIONS ARE EXPECTED TUESDAY INTO WEDNESDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...GALE WARNING FROM 3 AM TO 7 PM EST MONDAY FOR ANZ050>052.
&&
$$
NEAR TERM...HASTINGS/HEWITT
SHORT TERM...DUDA
LONG TERM...DUDA
AVIATION...HASTINGS/HEWITT
MARINE...HASTINGS/HEWITT/DUDA
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1109 AM EST SUN JAN 1 2012
.SYNOPSIS...
AN INTENSIFYING LOW PRESSURE SYSTEM WILL PUSH INTO THE GREAT LAKES
THIS AFTERNOON, BRINGING A STRONG COLD FRONT AND GUSTY WINDS ACROSS
THE UPPER OHIO VALLEY. THE COLDEST AIR OF THE SEASON WILL PUSH IN
BEHIND THE FRONT WITH SNOW SHOWERS EXPECTED TONIGHT INTO TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATE INCLUDES MINOR ADJUSTMENTS TO TEMPERATURES...AS WELL AS TIMING
OF PRECIPITATION AND CLOUD COVER OVER EASTERN SECTIONS BASED ON
RADAR/SATELLITE TRENDS. PREVIOUS DISCUSSION FOLLOWS.
THE LATEST RUC MID-LEVEL ANALYSIS INDICATES A 500MB TROUGH AXIS
EXTENDING FROM THE UPPER MIDWEST INTO THE MISSOURI VALLEY. AHEAD OF
THIS FEATURE, A WEAK RIDGE IS SHIFTING EAST OF THE UPPER OHIO
VALLEY. A DEEP LAYER OF DRY AIR IS IN PLACE, WITH STRATOCUMULUS
ASSOCIATED WITH A 1000-900MB LAYER MOISTURE PUSHING NORTHEAST OF
THE AREA. AT THE SURFACE, AS 1000MB LOW IS CENTERED ACROSS
NORTHERN ILLINOIS. WITH A 1021MB SURFACE HIGH CENTERED OFF THE
CAROLINA COAST, THE PRESSURE GRADIENT IS TIGHTENING ACROSS THE
OHIO VALLEY. IN ADDITION, A COLD FRONT EXTENDS SOUTHWARD OF THE
LOW ACROSS THE MISSOURI VALLEY.
TODAY...THE TROUGH WILL DIG INTO THE OHIO VALLEY AND THE SURFACE LOW
WILL MOVE NORTHEASTWARD ACROSS THE LP OF MICHIGAN, SWINGING THE
FRONT ACROSS THE UPPER OHIO VALLEY AND TIGHTENING THE PRESSURE
GRADIENT ACROSS THE AREA. THE FRONT WILL MOSTLY BE DRY WITH ITS
PASSAGE, ALTHOUGH WITH A TIGHT THERMAL GRADIENT AND HIRES MODELS
INDICATING SUFFICIENT FORCING, CHANCE POPS ARE FORECAST WITH ITS
PASSAGE.
THE MAIN WEATHER IMPACT TODAY WILL BE GUSTY WINDS WITH THE
FRONTAL PASSAGE AND DIURNAL MIXING IN CAA IN THE WAKE OF THE FRONT.
NAM/WRF-NMM SOLUTIONS SUPPORT SUSTAINED WINDS OF 20-25KTS WITH GUSTS
OF 35-40KTS AND THE ONGOING WIND ADVISORY. EXPECT THE GUSTS TO PICK
UP LATE THIS MORNING ACROSS EASTERN OHIO AND ACROSS THE REST OF THE
AREA BY EARLY AFTERNOON. FOR TEMPS, HIGHS WILL BE REACHED MOSTLY BY
18Z, AS CAA KICKS IN. TEMPS ARE A MAV/MET BLEND, RANGING FROM NEAR
50 ACROSS NORTHERN WV AND SOUTHWEST PA TO THE MID 40S FOR AREAS
NORTHWEST OF PITTSBURGH AND ACROSS THE EASTERN RIDGES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
THERE IS NAM/GFS AGREEMENT THAT THE MID-LEVEL TROUGH WILL DEEPEN AND
BECOME MORE AMPLIFIED AS IT MOVES ACROSS THE OHIO VALLEY TO THE EAST
COAST SUNDAY NIGHT THROUGH TUESDAY.
SUNDAY NIGHT...THE MID-LEVEL TROUGH WILL INSTIGATE SHOWERS ACROSS
THE AREA WITH LOW-LEVEL THICKNESSES QUICKLY DECREASING AND TURNING
PRECIPITATION OVER TO ALL SNOW SHOWERS. THE SURFACE LOW WILL PUSH
NORTHEAST INTO ONTARIO WITH GUSTS WEAKENING WITH THE DECREASE OF
MIXING WITH THE LOSS OF DIURNAL HEATING. WITH A TIGHTENED PRESSURE
GRADIENT, WINDS WILL STILL GUST AT 20-30KTS OVERNIGHT. FOR LOWS,
ONGOING CAA WILL BE IN PLACE, ALTHOUGH CLOUD COVERAGE WILL SERVE TO
COUNTER COLDER AIR ALOFT. LOWS WILL RANGE FROM THE LOWER 20S ACROSS
THE EASTERN RIDGES TO THE MID 20S ELSEWHERE. A LOW-LEVEL FLOW OUT OF
290 DEGREES WILL LIMIT LAKE EFFECT INITIALLY WITH AN INCH
FORECAST OVERNIGHT FOR THE I-80 CORRIDOR.
MONDAY AND MONDAY NIGHT...850MB FLOW WILL SHIFT TO
WEST-NORTHWESTERLY BY 18Z MONDAY AND TAP INTO A HURON FETCH AS IT
SHIFTS TO NORTHWESTERLY BY 00Z TUESDAY. THIS WILL ALLOW FOR LAKE
EFFECT SNOW SHOWERS AND UPSLOPING EVENT TO BEGIN IN EARNEST. WITH
850MB TEMPS NEAR -13C AND A WARM LAKE ERIE WITH TEMPS NEAR 4C, THE
TEMP DIFFERENTIAL WILL BE SUFFICIENT ALONG WITH A DEEP ISOTHERMAL
PROFILE. THUS, ACCUMULATIONS ARE FORECAST OF 4 TO 8 INCHES WITH BANDING OF
SNOWFALL ACROSS THE LAKE EFFECT ZONES AND UPSLOPING FOR THE
RIDGES. EXPECT 2 TO 4 INCHES SOUTH OF I-80 AND NORTH OF PITTSBURGH
WITH 1 TO 3 INCHES FOR AREAS SOUTH AND WEST OF PITTSBURGH.
TUESDAY...ONGOING LAKE EFFECT SNOW EVENT WILL BEGIN TO WIND DOWN
AS A SURFACE HIGH AND LOW-LEVEL RIDGING BUILD INTO THE UPPER OHIO
VALLEY. A LOWERING SUBSIDENCE INVERSION WILL MOSTLY DIMINISH THE
MORE PERSISTENT ACCUMULATING SNOW SHOWERS FOR THE RIDGES AND I-80
CORRIDOR BY THE AFTERNOON HOURS WITH SNOW SHOWERS COMING TO AN END
ELSEWHERE. THE CORE OF THE COLDEST AIR WILL HAVE BUILT IN, WITH
HIGHS STRUGGLING TO REACH THE LOWER 20S ACROSS MUCH OF THE AREA.
GUSTY WINDS OF 20-25KTS ALONG WILL YIELD WIND CHILLS IN THE
SINGLE DIGITS ACROSS THE LOWLANDS AND BELOW ZERO ACROSS THE HIGHER
ELEVATIONS MONDAY THROUGH TUESDAY.
BY THE END OF THIS EVENT, STORM TOTAL ACCUMULATIONS OF 8 TO 12
INCHES WILL BE POSSIBLE FOR THE RIDGES WITH THE I-80 CORRIDOR
GETTING 6 TO 10 INCHES. THUS, LAKE EFFECT SNOW AND WINTER STORM
WATCHES HAVE BEEN UPGRADED TO WARNINGS. THE NEXT TIER OF COUNTIES
SOUTH OF I-80 AND NORTH OF PITTSBURGH MAY NEED ADVISORIES, HOWEVER
AT THIS TIME, CONFIDENCE IN ACCUMULATIONS REACHING 12-HOUR/24-HOUR
CRITERIA IS TOO LOW THERE. THUS, THE WINTER STORM WATCH FOR
JEFFERSON AND CLARION COUNTIES REMAINS IN EFFECT.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THERE IS REASONABLE NAEFS/ECMWF MEAN AGREEMENT THAT HIGH PRESSURE WILL
CROSS THE AREA ON TUESDAY NIGHT, BRINGING A DRY FORECAST AND A
RESPITE FROM SNOW SHOWERS. WITH THE COLDEST AIR OF THE SEASON SET IN
AND RADIATIONAL COOLING POSSIBLE, LOWS TUESDAY NIGHT WILL RANGE FROM
THE SINGLE DIGITS ACROSS THE EASTERN RIDGES TO THE LOWER TEENS
ACROSS THE REMAINDER OF THE AREA.
GFSE/ECMWF BLEND WAS USED FOR THE REMAINDER OF THE PERIOD. A ZONAL
MID-LEVEL FLOW WILL BE IN PLACE FOR WEDNESDAY WITH THE SLIGHT CHANCE
OF SNOW SHOWERS. A SHORT WAVE WILL CROSS THE AREA ON WEDNESDAY NIGHT
INTO THURSDAY BRINGING A BETTER CHANCE OF SNOW SHOWERS. WEAK SURFACE
RIDGING IS PROGGED TO DRY THE FORECAST OUT FOR THURSDAY NIGHT INTO
FRIDAY. A FRONT IS THEN PROGGED TO CROSS THE UPPER OHIO VALLEY FOR
THE EARLY WEEKEND. TEMPS WILL BE PROGRESSIVELY WARMER MID-WEEK INTO
THE WEEKEND, AT AROUND 5 DEGREES BELOW NORMAL ON WEDNESDAY AND
WARMING EACH DAY TO 10 DEGREES ABOVE NORMAL BY FRIDAY AND SATURDAY.
&&
.AVIATION /16Z SUNDAY THROUGH THURSDAY/...
BKN-OVC SKIES SHOULD PREVAIL IN ADVANCE OF AN APPROACHING COLD
FRONT...WITH SITES BOUNCING BETWEEN MVFR/VFR DUE TO CEILINGS VARYING
BETWEEN 2500 AND 3500 FT. LOW LEVEL WIND SHEAR IS ALSO PRESENT AT
TAF SITES. ALTHOUGH SOME SHOWERS HAVE MOVED THROUGH AHEAD OF THE
COLD FRONT (NEAR THE INDIANA-OHIO BORDER AROUND 11AM)...ADDITIONAL
SHOWERS AND A SHARP RISE IN WINDS CAN BE EXPECTED WHEN THE FRONT
MOVES THROUGH. HAVE CONTINUED TO AMEND TAFS TO TRY AND BETTER
HIGHLIGHT TIMING OF FRONT...WITH WINDS SHIFTING FROM SOUTHERLY TO
WESTERLY AND GUSTS UP TO 40 KTS. EXPECT GENERAL MVFR CIGS BEHIND THE
FRONT. STRONG COLD ADVECTION WILL BRING LIGHT SNOW SHOWERS LATE
AFTERNOON OR EVENING AND CONTINUE INTO THE OVERNIGHT WITH WEST WINDS
REMAINING GUSTY.
OUTLOOK...MONDAY THROUGH THURSDAY
GUSTY WINDS WILL REMAIN MONDAY AND TURN NORTHWEST WITH IFR
RESTRICTIONS POSSIBLE WITH SNOW SHOWERS MONDAY THROUGH TUESDAY
NIGHT. VFR CONDITIONS WILL RETURN WEDNESDAY BEFORE THE NEXT
DISTURBANCE BRINGS THE CHANCE OF SNOW SHOWERS WITH RESTRICTIONS ON
THURSDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR MDZ001.
WINTER STORM WARNING FROM 1 AM MONDAY TO 4 PM EST TUESDAY FOR
MDZ001.
OH...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR OHZ039>041-
048>050-057>059-068-069.
PA...WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR PAZ007>009-
013>016-020>023-029-031-073>076.
WINTER STORM WARNING FROM 1 AM MONDAY TO 4 PM EST TUESDAY FOR
PAZ074-076.
LAKE EFFECT SNOW WARNING FROM 1 AM MONDAY TO 4 PM EST TUESDAY
FOR PAZ007>009.
WINTER STORM WATCH FROM LATE TONIGHT THROUGH TUESDAY EVENING
FOR PAZ015-016.
WV...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR WVZ001>004-012.
WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR WVZ021>023-041.
WINTER STORM WARNING FROM 1 AM MONDAY TO 4 PM EST TUESDAY FOR
WVZ023-041.
&&
$$
AREA FORECAST DISCUSSION
NWS DULUTH MN
1212 PM CST SUN JAN 1 2012
.AVIATION...18Z ISSUANCE...
WIDESPREAD MVFR/VFR CEILINGS AND VSBYS WITH STRONG NORTHWEST
WINDS GUSTING AROUND 30 KNOTS WILL PREVAIL THROUGH 04Z. A FEW
GUSTS TO 40 KTS WILL BE POSSIBLE THROUGH 02Z...MAINLY NEAR KBRD
AND KDLH. BRIEF PERIODS OF LIFR VSBYS WILL BE FOUND IN HEAVIER SNOW
SHOWERS DUE TO BLSN. CONDITIONS WILL IMPROVE EARLY MONDAY MORNING
AS WINDS DIMINISH AND SKIES SCATTER FROM THE WEST. THE EXCEPTION
WILL BE OVER WISCONSIN AREAS AND THE KHYR TERMINAL WHERE
ADDITIONAL LAKE EFFECT SNOW SHOWERS AND CLOUDS WILL LINGER THROUGH
MONDAY AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 947 AM CST SUN JAN 1 2012/
UPDATE...INCREASE POPS ACROSS MN ZONES THIS MORNING AS AREA OF
ENHANCED MOISTURE WITHIN 85/70H LATER ADVECTS SOUTHEASTWARD.
LATEST RUC13 ANALYSIS SHOWS -35C/50H COLD POOL IS MOVING ACROSS
CWA THIS MORNING. ACCUMULATIONS OF AN INCH OR LESS ARE POSSIBLE.
VERY WEAK OMEGA EVIDENT IN FCST ACROSS MOST OF CWA TODAY...EXCEPT
ERN WISC ZONES WHERE LES WARNING CONTINUES. WIND ADV WILL BE LOW
END FOR THE MOST PART WITH GUSTS OF 40 MPH POSSIBLE...SUSPECT
HIGHER GUSTS MAY BE ISOLATED IN AREAL COVERAGE.
LAKE EFFECT...LATEST RUC ANALYSIS SHOWS 85H TEMPS AT -10C ACROSS LAKE
SUPERIOR SO LAKE SFC/85H TEMP DELTA T IS NEAR EMPIRICAL THRESHOLD
FOR INCREASING LAKE INDUCED CONVECTION. FCST STILL PUSHES 85H
THERMAL TROUGH OVER LAKE IN NEXT 24 HRS SO WILL MAINTAIN LES
WARNING. SPATIAL AND TEMPORAL TRENDS IN LAKE SNOW PARAMETER
SUGGESTS ACTIVITY SHOULD INCREASE SIGNIFICANTLY THIS AFTERNOON AND
CONTINUE OVERNIGHT.
PREV DISCUSSION... /ISSUED 426 AM CST SUN JAN 1 2012/
SHORT TERM...LATEST KDLH RADAR IMAGERY SHOWS THE SYNOPTICALLY
FORCED SNOW WINDING DOWN ACROSS THE NORTHLAND EARLY THIS
MORNING...WITH THE COLD FRONT NOW EAST OF OUR CWA. WINDS HAVE
TURNED OUT OF THE WEST/NORTHWEST AND HAVE STRENGTHEN ACROSS MOST
OF OUR FCST AREA. THIS TREND WILL CONTINUE TODAY AS MIXING
INCREASES CREATING BLUSTERY CONDITIONS. BECAUSE THE SNOW IS COMING
TO AN END...WE HAVE CANCELLED MANY OF THE WINTER WEATHER
ADVISORIES AND WARNINGS. HOWEVER BECAUSE OF THE STRENGTHENING
WINDS...WE HAVE ISSUED A WIND ADVISORY ALONG AND SOUTH OF THE
HIGHWAY 2 CORRIDOR. THE ADVISORY MAY NEED TO BE EXPANDED NORTHWARD
IF OBSERVATIONS WARRANT. HOWEVER THE MAIN FORECAST CONCERN FOR
THE SHORT TERM WILL BE THE POTENTIAL FOR LAKE EFFECT SNOW ALONG
THE SOUTHSHORE THROUGH MONDAY. NWP MODEL GUIDANCE CONTINUES TO
SUGGEST AN ADDITIONAL 6 TO 12 INCHES OF SNOW ACCUMULATION IS
POSSIBLE...WITH THE HEAVIER AMOUNTS ACROSS THE GOGEBIC RANGE.
THEREFORE WILL KEEP THE WARNING GOING FOR BAYFIELD...ASHLAND AND
IRON COUNTIES UNTIL 6PM MONDAY. BECAUSE OF THE STRONG WINDS...WE
WILL ALSO MENTION THE POSSIBILITY OF BLOWING SNOW. ELSEWHERE
CONDITIONS WILL BE MAINLY DRY ALTHOUGH COLD.
LONG TERM...MONDAY NIGHT THROUGH NEXT SUNDAY.
THE SEVERAL-MONTH-OLD PATTERN OF A DEEP AND STRONG PACIFIC FLOW
ACROSS THE NORTHERN HALF OF THE UNITED STATES AND THE SOUTHERN
HALF OF CANADA WILL CONTINUE THROUGH THE WEEK AND COMING WEEKEND.
STRONG WARM AND DRY CHINOOKS WILL PERIODICALLY DEVELOP OVER THE
CENTRAL CANADIAN THROUGH THE MONTANA ROCKIES AND SPREAD ACROSS OUR
AREA... BRINGING SPRING LIKE WARMTH AND A DRY COLUMN. THE CURRENT
INTERRUPTION...COLD WEATHER WITHIN THE SEASONAL RANGE...THROUGH
TUESDAY...WILL BE FOLLOWED BY ABOVE FREEZING AFTERNOONS WEDNESDAY
THROUGH FRIDAY...WITH TEMPERATURES REMAINING IN THE 20S ACROSS THE
ENTIRE AREA THURSDAY NIGHT. A TEMPORARY SHOT OF LOWER TEMPERATURES
WILL FOLLOW THIS COMING WEEKEND. LITTLE IF ANY PRECIPITATION WILL
FALL DURING THIS PERIOD.
&&
.POINT TEMPS/POPS...
DLH 27 3 13 -4 / 60 10 0 0
INL 28 0 8 -12 / 60 20 0 0
BRD 26 6 16 1 / 60 10 0 0
HYR 27 7 14 -11 / 50 30 10 0
ASX 29 10 16 -3 / 70 60 40 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WIND ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR MNZ033>038.
WI...WIND ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR WIZ001-006>009.
WINTER STORM WARNING UNTIL 6 PM CST MONDAY FOR WIZ002>004.
LS...GALE WARNING UNTIL 4 PM CST MONDAY FOR LSZ121-140>148.
&&
$$
SHORT TERM...CANNON
LONG TERM....GRANING
AVIATION...GRANING
AREA FORECAST DISCUSSION
NWS HASTINGS NE
200 PM CST SUN JAN 1 2012
.UPDATE...KGRI...KAUH AND KJYR AND HAVE EITHER BEEN CLOSE OR EXCEEDED
WIND ADVISORY CRITERIA THROUGH THE PAST HOUR OR SO. LATEST RUC
GUIDANCE SUGGESTS THE WESTERN PERIPHERY OF STRONGEST 850-700MB
WINDS HAVE PUSHED A TAD FARTHER SOUTH/SOUTHWEST THAN PREVIOUSLY
ANTICIPATED AND AS A RESULT...STRONGER WIND GUSTS AT THE SURFACE
ARE ALSO BEING OBSERVED FARTHER SOUTH/SOUTHWEST. RUC GUIDANCE
SUGGESTS THE AXIS OF STRONGEST 850-700MB WINDS SHOULD DIMINISH
AND PUSH EAST SOME THROUGH THE NEXT 2-3 HOURS...BUT FEELING
CONFIDENT ENOUGH TO EXPAND THE WIND ADVISORY CLOSER TO THE I-80
CORRIDOR. WINDS WILL ALSO RAPIDLY DIMINISH TOWARDS SUNSET AS THE PBL
DECOUPLES FROM THE STRONGER WINDS JUST ABOVE THE SURFACE...THUS
KEPT THE ADVISORY EXPIRATION TIME SET AT 00Z.
&&
.PREV DISCUSSION... /ISSUED 1158 AM CST SUN JAN 1 2012/
UPDATE...MIDDAY SURFACE ANALYSIS INDICATES A RIDGE OF HIGH
PRESSURE CONTINUES WORKING INTO THE REGION FROM THE NORTHWEST. THE
LOW LEVEL WIND FIELD ACROSS OUR AREA REMAINS FROM THE NORTHWEST AS
A RESULT. THESE WINDS HAVE INCREASED SOME THROUGH THE PAST HOUR OR
TWO AND WITH AFTERNOON PBL MIXING EXPECTED TO CLIMB TO NEAR
800MB...CURRENTLY EXPECT THE GUST POTENTIAL TO INCREASE TO NEAR
35KTS ACROSS MUCH OF THE CWA DURING THE AFTERNOON...WITH SLIGHTLY
STRONGER WINDS POSSIBLE ACROSS OUR EXTREME NORTH/NORTHEAST. GIVEN
THIS WILL KEEP THE CURRENT WIND ADVISORY GOING AS IS.
PREV DISCUSSION... /ISSUED 1116 AM CST SUN JAN 1 2012/
AVIATION...18Z KGRI TAF. VFR CONDITIONS TO CONTINUE THROUGH THE
NEXT 24 HOURS. HIGH LEVEL CLOUDS NO LOWER THAN 20000FT AGL ARE
EXPECTED AT TIMES. SURFACE WINDS WILL INCREASE IN INTENSITY THIS
AFTERNOON AS THE LOW LEVEL PRESSURE GRADIENT INCREASES SOMEWHAT.
AFTERNOON PBL MIXING TO NEAR 800MB WILL ALSO PROMOTE A GUST POTENTIAL
NEAR 35KTS. SURFACE WINDS WILL SUBSIDE TOWARDS SUNRISE AS THE LOW
LEVEL PRESSURE GRADIENT WEAKENS AND THE PBL HEIGHT DECREASES.
VISIBILITY RESTRICTIONS ARE NOT EXPECTED THROUGH THE NEXT 24 HOURS.
PREV DISCUSSION... /ISSUED 315 AM CST SUN JAN 1 2012/
SHORT TERM...TODAY THROUGH 12Z WEDNESDAY. THE MAIN CONCERN WILL BE
WINDS TODAY. NORTHWESTERLY FLOW WILL BE IN PLACE ALOFT ACROSS THE
CENTRAL PLAINS TODAY WITH A LARGE RIDGE OVER THE WESTERN UNITED
STATES. AT THE SURFACE...LOW PRESSURE OVER EASTERN IOWA WILL
CONTINUE TO MOVE NORTHEAST...WHILE HIGH PRESSURE BUILDS INTO THE
HIGH PLAINS. THIS WILL KEEP A FAIRLY TIGHT SURFACE PRESSURE
GRADIENT IN PLACE...WITH THE TIGHTEST GRADIENT EXPECTED TO BE IN
THE NORTHEAST PORTION OF THE FORECAST AREA. NAM BUFR SOUNDINGS
SHOW GOOD MIXING TODAY AS LOW LEVEL LAPSE RATES STEEPEN...AND
MOMENTUM TRANSFER POINTS TO THE STRONGEST WINDS FROM KOFK TO
KODX. AFTER COORDINATION WITH SURROUNDING OFFICES...HAVE DECIDED
TO GO AHEAD AND HOIST A WIND ADVISORY FOR VALLEY...GREELEY AND
NANCE COUNTIES. THOSE AREAS APPEAR TO HAVE THE BEST CHANCE OF
SEEING GUSTS TO AROUND 45 MPH...THOUGH IT COULD BE MARGINAL AT
TIMES. IN REGARDS TO HIGHS...HAVE GENERALLY GONE WITH READINGS IN
THE UPPER 30S TO MID 40S.
COLD HIGH PRESSURE WILL BE IN PLACE TONIGHT. THIS WILL BRING CLEAR
SKIES AND LIGHT WINDS...WHICH WILL HELP TEMPERATURES FALL NICELY
OVERNIGHT. A BLEND OF GUIDANCE BRINGS LOWS INTO THE 8 TO 18
DEGREE RANGE...AND SEE NO REASON TO STRAY TOO FAR FROM THOSE
VALUES.
THE UPPER RIDGE SLIDES EAST ON MONDAY WHICH WILL HELP BRING WARMER
AIR ALOFT BACK INTO THE CENTRAL PLAINS. H85 TEMPERATURES RISE
APPROXIMATELY 6 DEGREES CELSIUS...BUT MIXING IS WORSE THAN TODAY
AND THE COOL START TO THE DAY WILL ALSO HAVE AN IMPACT ON HIGHS.
WILL SHOW MAX TEMPERATURES IN THE MID 30S TO LOWER 40S.
H85 WARM AIR ADVECTION CONTINUES THROUGH MONDAY NIGHT. THIS
SHOULD HELP TEMPERATURES STEADY OUT OVERNIGHT AFTER THE INITIAL
DROP DURING THE EVENING. HAVE GONE WITH LOWS IN THE TEENS AND
LOWER 20S ACROSS THE FORECAST AREA.
A WAVE TOPS THE H5 RIDGE ON TUESDAY WHICH WILL PUSH A COLD FRONT
THROUGH THE AREA. DESPITE THE COLD AIR ADVECTION THAT TAKES
HOLD...TEMPERATURES SHOULD WARM UP SOME FROM MONDAY WITH A GOOD
DOWNSLOPE COMPONENT TO THE WINDS. WILL AIM FOR HIGHS IN THE MID
40S TO LOWER 50S.
LONG TERM...WEDNESDAY THROUGH SATURDAY. WITH THE MAJORITY OF THIS
TIME FRAME CARRYING ESSENTIALLY ZERO RISK FOR PRECIPITATION...THE
PRIMARY CHALLENGE IS JUST HOW WARM TO GO WITH HIGH TEMPERATURES AS
THIS FAIRLY NOTABLE STRETCH OF EARLY-MID WINTER MILDNESS CONTINUES.
FOR WEDNESDAY/WEDNESDAY NIGHT...00Z ECMWF/GFS RUNS ARE IN GOOD
AGREEMENT THAT THIS REMAINS THE TIME FRAME OF THE ENTIRE 7-DAY
FORECAST WITH THE HIGHEST MID LEVEL HEIGHTS/MOST PRONOUNCED RIDGING
OVER THE CENTRAL CONUS...IN BETWEEN A TROUGH OVER THE NORTHEAST AND
AN INCOMING SHORTWAVE INTO THE PAC NORTHWEST REGION. AT THE
SURFACE...BROAD FAIRLY LIGHT BUT STEADY WESTERLY DOWNSLOPE FLOW IS
THE STORY...AS H85 TEMPS RISE INTO THE 7-10C RANGE DURING THE
AFTERNOON. ALTHOUGH FULL MIXING WILL LIKELY FALL SHORT OF THIS
LEVEL...SAW NO REASON NOT TO NUDGE UP HIGH TEMPS 1-2 DEGREES FROM
PREVIOUS FORECAST...NOW DEPICTING AT LEAST LOW 50S EVERYWHERE...AND
MID 50S IN SOME WESTERN/SOUTHERN COUNTIES. ULTIMATELY...MID 50S
MIGHT PROVE TO BE MORE WIDESPREAD THAN ADVERTISED...ASSUMING PASSING
CIRRUS ISN/T THICK ENOUGH TO INTERFERE. FOR LOWS WED NIGHT...HELD
ALL AREAS UP IN THE LOW 30S.
THURS/THURS NIGHT...THIS STILL LOOKS LIKE THE OVERALL WARMEST DAY
OF THE FORECAST PERIOD. ALTHOUGH THE MID LEVEL RIDGE GETS FLATTENED
BY LOW AMPLITUDE DISTURBANCES TRACKING FROM THE PAC NORTHWEST ACROSS
THE NORTHERN ROCKIES/NORTHERN PLAINS...THE SITUATION IN THE LOW
LEVEL REMAINS MUCH THE SAME WITH PERSISTENT WESTERLY FLOW. THE
ECMWF/GFS BOTH CONTINUE TO ADVERTISE 850MB TEMPS SOARING INTO THE
+13-15C RANGE DURING THE DAY...WHICH IS QUITE NOTABLE FOR EARLY
JANUARY. AGAIN...NOT EXPECTING FULL MIXING UP TO THIS LEVEL...BUT
STILL BUMPED HIGHS ANOTHER DEGREE OR SO ABOVE PREVIOUS FORECAST WITH
UPPER 50S MOST AREAS...AND INTRODUCED 60 IN THE FAR SOUTHWEST.
AGAIN...THIS COULD ULTIMATELY PROVE TO BE A SOMEWHAT CONSERVATIVE
FORECAST...WITH POTENTIAL CERTAINLY THERE FOR WIDESPREAD LOW 60S OR
EVEN HIGHER...WHICH COULD EVEN THREATEN RECORD HIGHS FOR JAN 5TH IN
PARTS OF THE CWA.
FRIDAY/FRIDAY NIGHT...IN THE WAKE OF A COLD FRONT THAT PUSHES SOUTH
ACROSS THE AREA THURS NIGHT...FRIDAY HIGHS LOOK TO AVERAGE 5-10
DEGREES COOLER THAN THURS...BUT STILL WELL-ABOVE NORMAL...AND KEPT
SIMILAR TO PREV FORECAST WITH UPPER 40S NORTHWEST TO LOW 50S SOUTH.
IF THE ECMWF ENDS UP MORE CORRECT WITH ITS LESS ROBUST COLD AIR
ADVECTION THAN THE GFS...THIS MIGHT BE YET ANOTHER DAY WE ARE
UNDER-FORECASTING HIGHS...AS IT MIGHT END UP MORE LIKE MID 50S MOST
AREAS. BY FRIDAY NIGHT...MODELS START TO DIVERGE A BIT WITH EXACTLY
WHAT HAPPENS WITH INDIVIDUAL SHORTWAVES DROPPING THROUGH THE NORTH
CENTRAL/NORTHWEST CONUS...WITH THE ECMWF ACTUALLY DEPICTING SOME
LIGHT PRECIP POSSIBLY FLIRTING WITH MAINLY THE SOUTHWEST CWA LATE
FRIDAY NIGHT WITHIN A SOUTHWARD-SAGGING UPPER LEVEL JET AXIS. FOR
NOW CONFIDENCE IN PRECIP IS WAY TOO LOW TO INTRODUCE A MENTION.
SATURDAY...MODELS CONTINUE TO DIVERGE WITH THE DETAILS...BUT GENERAL
CONSENSUS IS THAT GREATEST FORCING FOR PRECIP PRODUCTION REMAINS
TIED TO SHORTWAVES WELL EAST OF THE CWA...AND ALSO TO THE SOUTHWEST
PER THE ECMWF. WILL CONTINUE TO KEEP IT DRY FOR NOW. CONFIDENCE IN
HIGH TEMPS IS NOT GREAT...SO STUCK WITH CONSENSUS BLEND WITH UPPER
30S NORTH TO MID 40S SOUTH. LOOKING OUT THROUGH ROUGHLY JAN
10TH...ALTHOUGH THERE ARE NO ANOMALOUSLY WARM DAYS EVIDENT...LOOKS
LIKE MORE DAYS IN THE 40S OR 30S...AND NO SIGNS OF A MAJOR PRECIP
EVENT.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR NEZ039>041-046>049-
062>064.
KS...NONE.
&&
$$
UPDATE/AVIATION...BRYANT
SHORT TERM...KING
LONG TERM...PFANNKUCH
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1159 AM CST SUN JAN 1 2012
.UPDATE...
SFC OBS FROM KVTN...KANW AND NEDOR HAVE COME UP TO WIND ADVISORY
CRITERIA. THE RUC SUGGESTS WIND ADVISORY SPEEDS THIS AFTN IN THAT
AREA SO THE ADVISORY HAS BEEN PUSHED FARTHER WEST TO INCLUDE
EASTERN CHERRY COUNTY.
&&
.PREV DISCUSSION... /ISSUED 540 AM CST SUN JAN 1 2012/
AVIATION...
FOR THE KLBF AND KVTN TERMINALS THROUGH 12Z MONDAY.
WITH THE EXCEPTION OF SOME MID LEVEL CLOUDINESS OVER NORTHERN
NEBRASKA THIS MORNING...MOSTLY CLEAR SKIES ARE EXPECTED TODAY AND
TONIGHT ACROSS WESTERN AND NORTH CENTRAL NEBRASKA. NORTHWESTERLY
WINDS WILL BE GUSTY TODAY...ESPECIALLY EAST OF A LINE FROM KANW TO
KBBW. IN THESE AREAS...SURFACE WIND GUSTS UP TO 40 KTS ARE POSSIBLE
BETWEEN 16Z AND 00Z TODAY. ELSEWHERE...WIND GUSTS UP TO 30 KTS ARE
POSSIBLE TODAY WITH WINDS DIMINISHING TO UNDER 10 KTS TONIGHT.
PREV DISCUSSION... /ISSUED 338 AM CST SUN JAN 1 2012/
SYNOPSIS...
STRONG LOW PRESSURE SYSTEM...THAT BROUGHT THE GUSTY WINDS
YESTERDAY...HAS PUSHED INTO THE MID MISS RVR VALLEY. MEANWHILE
HIGH PRESSURE AND MOSTLY CLEAR SKIES MOVING EAST ACROSS THE
CENTRAL/NORTHERN ROCKIES. SKIES HAVE CLEARS OVER THE
CWA...HOWEVER STILL GETTING SOME MIXING WITH TIGHT PRESSURE
GRADIENT BETWEEN THE HIGH AND LOW...HELPING TO HOLD TEMPS IN 20S
FOR THE MOST PART AT 09Z...EVEN A FEW LOW 30S OVER CENTRAL NEB.
DISCUSSION...
NEW YEAR TO START OFF SEASONAL TEMPS...DRY...AND
WINDY...ESPECIALLY OVER NORTH CENTRAL. 500 MB RIDGE ANCHORED OVER
THE WESTERN STATES WITH A DEEP TROUGH OVER THE EAST. THIS
CONTINUES NORTHWEST FLOW OVER THE CWA TODAY. COLD AIR BEHIND
YESTERDAYS COLD FRONT HAS BROUGHT 850 TEMPS DOWN TO AROUND -2C IN
SW NEB TO NEAR -10C IN N CENTRAL. LIMITED RELIEF IN TEMPS EXPECTED
TODAY...HOWEVER RANGE OF TEMPS TODAY NOT EXPECTED TO BE AS
GREAT AT 850 MB TEMPS WOULD SUGGEST...DUE TO BETTER MIXING OVER
NORTH CENTRAL. AS A RESULT OF THE MIXING...EXPECT WINDS TO PUSH
NEAR ADVISORY CRITERIA. MODELS IN GOOD AGREEMENT WITH 850 MB WINDS
AROUND 40KTS OVER N CENTRAL. MOS GUIDANCE HIGHEST FOR ONL AND WILL
ISSUE AN ADVISORY TO COVER THE NE 4 COUNTIES. POSSIBLE EXPANSION
MAYBE NEEDED FOR THE NEXT TIER TO THE WEST OF COUNTIES...HOWEVER
WINDS HAVE DIMINISHED MORE THERE ALREADY AND EXPECT THIS TO
CONTINUE THROUGH THE DAY. ANOTHER LIMITING FACTOR WILL BE AN
INCREASE OF MID/HIGH CLOUDS. WATER VAPOR HAS DECENT PLUM OF
MOISTURE ROUNDING THE RIDGE AND WILL ATTEMPT TO CROSS THE ROCKIES.
SO FAR MOISTURE HAS STRUGGLES TO CROSS THE DIVIDE...HOWEVER...AS
WAS THE CASE MUCH OF LAST WEEK...EXPECT SOME MOISTURE/CLOUDS TO
MAKE IT OVERHEAD DURING THE AFTERNOON. THIS WILL ALSO PUT A DAMPER
ON THE MIXING FROM WEST TO EAST AS TEMPS FAIRLY UNIFORM OVER NORTH
CENTRAL IN THE MID 30S.
HIGH PRESSURE SETTLES OVERHEAD TONIGHT WITH WINDS EXPECTED TO
DECOUPLE AND TEMPS TO PLUMMET. TEMPS IN THE SINGLE DIGITS TO LOW
TEENS ARE EXPECTED.
COLD TEMPS ARE SHORT LIVED AS HIGH QUICKLY SLIDES SOUTH WITH SE
WINDS DEVELOPING FOR MONDAY. HIGHS ON MONDAY NOT TOO FAR FROM
TODAY...BUT THE WARM AIR IS BUILDING TO THE SW. WARM FRONT SURGES
ACROSS THE AREA BY TUESDAY WITH HIGHS TUESDAY INTO THE 50S FOR
MOST OF THE AREA. UNSEASONABLE WARM TEMPS AND DRY CONTINUES
THROUGH MID WEEK. WARMEST DAY LOOKS TO BE THURSDAY WHERE SOME
HIGHS IN THE 60S LIKELY. RECORDS ARE IN THE MID 60S AND WILL
CONTINUE TO MONITOR. CURRENT FORECAST IS STILL BELOW RECORDS...BUT
NOT BY MUCH.
NEXT COLD FRONT ARRIVES FRIDAY WITH TEMPS ON THE DOWNWARD
SLIDE...BUT NO BITTER ARCTIC COLD YET. HIGHS BEHIND THE FRONT ON
SATURDAY AND SUNDAY IN THE 30S TO AROUND 40...CLOSE TO NORMAL THIS
TIME OF YEAR. LIMITED MOISTURE WITH FRONTAL PASSAGE...AND BEST
ENERGY IN THE NORTHERN STREAM...NEAR THE US/CAN BORDER AND WILL
CONTINUE A DRY FORECAST.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...WIND ADVISORY UNTIL 6 PM CST
THIS EVENING FOR NEZ005>010-027>029.
&&
$$
SHORT TERM...CDC
AVIATION/EXTENDED...TAYLOR
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
306 PM CST SUN JAN 1 2012
.SHORT TERM...TONIGHT AND MONDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW LOW PRESSURE
MOVING TO THE NORTHEAST OVER LAKE HURON THIS AFTERNOON WHILE HIGH
PRESSURE HAS SETTLED OVER THE FRONT RANGE OF THE ROCKIES. STRONG
SHORTWAVE OVER SOUTHERN WISCONSIN IS CONTRIBUTING TO WIDESPREAD SNOW
SHOWERS AND FLURRIES ACROSS THE REGION...BUT THE SNOW SHOWERS EXIST
ALL THE WAY BACK TO NORTHERN MINNESOTA AND SW ONTARIO. LAKE EFFECT
SNOWS REMAIN NORTH OF THE U.P. BORDER SO FAR...BUT WITH SOME
IMPRESSIVE BANDS ON THE MQT RADAR. MEANWHILE...WIND GUSTS THIS
AFTERNOON HAVE REMAINED WELL BELOW ADVISORY CRITERIA SO FAR. HAVE
HAD A FEW GUSTS IN THE 34-37 KT RANGE OVER CENTRAL WISCONSIN LATE
THIS MORNING...BUT HAVE SINCE DIMINISHED. HEADLINES AND SNOW
AMOUNTS REMAIN THE MAIN FORECAST CONCERN IN THE SHORT TERM.
TONIGHT...LOW PRESSURE WILL EXIT THE REGION INTO QUEBEC WHILE ARCTIC
HIGH PRESSURE MOVES EAST OVER THE GREAT PLAINS. A TIGHT PRESSURE
GRADIENT WILL REMAIN IN PLACE BETWEEN THESE TWO FEATURES WITH 0-1KM
AGL WIND SPEEDS AROUND 35 KTS. DESPITE THE COLD ADVECTION
TODAY...WIND GUSTS HAVE BEHAVED AND HAVE ONLY BRIEFLY APPROACHED
ADVISORY CRITERIA OVER CENTRAL WISCONSIN. WILL MONITOR WIND GUSTS
UNTIL THE LAST MINUTE BEFORE MAKING HEADLINE DECISIONS ON THE WIND
ADVISORY. AFTER COORDINATION...WILL LEAVE WIND HEADLINES IN PLACE
AS A TIGHT PRESSURE GRADIENT UPSTREAM AND COLD ADVECTION CONTINUES.
STILL PLENTY GOING ON BESIDES THE GUSTY WINDS. SHORTWAVE TROUGH
NEAR MSN WILL BE EXITING OVER SOUTHERN LAKE MICHIGAN DURING THE
EVENING. ANOTHER SHEARED WAVE OVER LAKE WINNIPEG WILL DIVE
SOUTHEAST OVER THE NORTHERN MISSISSIPPI VALLEY TONIGHT AND KEEP WEAK
QG FORCING IN PLACE. COMBINED WITH 1-3SM SNOW OBS ALL THE WAY NORTH
OF INTERNATIONAL FALLS AND SATURATION OF THE COLUMN ABOVE THE -10C
LINE IN PROGGED SOUNDINGS...WILL LEAVE A SCATTERED SNOW SHOWER
MENTION ACROSS THE FORECAST AREA FOR THE DURATION OF THE EVENING.
THE BIGGEST IMPACT WILL BE THE LAKE EFFECT SNOW OVER NORTH-CENTRAL
WISCONSIN. CONDITIONS WILL BE IMPROVING FOR SIGNIFICANT
ACCUMULATIONS THROUGH THE NIGHT. MAY NOT BE A WHOLE LOT OF IMPACT
THIS EVENING...AS WIND DIRECTIONS OF 320-330 ARE NOT CONDUCIVE FOR
ACCUMS EXCEPT ALONG THE U.P. BORDER. BUT TRAJECTORIES WILL VEER
SLIGHTLY TO 340 DEGREES BY 12Z MONDAY. WITH DELTA T/S IN THE UPPER
TEENS AND 850-700MB MOISTURE OF 80 PCT...SHOULD SEE GOOD DENDRITIC
SNOW GROWTH TO GENERATE A HALF INCH TO ONE INCH PER HOUR SNOWFALL
RATES BY THIS TIME. WILL LOWER SNOW AMOUNTS IN THE EVENING...BUT
KEEP THEM AROUND 2-3 INCHES DURING THE OVERNIGHT PERIOD. THIS WILL
YIELD 3-5 INCH AMOUNTS...HIGHEST OVER THE NORTHERN PART OF VILAS
COUNTY.
MONDAY...THE LAKE EFFECT SHOW WILL CONTINUE OVER N-C WISCONSIN
DURING THE MORNING. BUT CONDITIONS WILL TURN INCREASINGLY HOSTILE
DURING THE 15-18Z TIMEFRAME AS DRY ARCTIC AIR FLOWS OVER WESTERN
LAKE SUPERIOR. AS A RESULT...SNOWFALL RATES SHOULD BE DIMINISHING
BY MIDDAY AND THROUGH THE AFTERNOON...AS THE DRY AIR SURGES
SOUTHEAST. WILL GO WITH AN ADDITIONAL 2-4 INCHES IN THE FORECAST.
CLOUDY TO MOSTLY CLOUDY CONDITIONS WILL EXIST ELSEWHERE. LEFT AN
ISOLATED FLURRY MENTION GOING FOR THE MORNING BEFORE THE DRIER AIR
ARRIVES. SOME BREAKS IN THE CLOUDS ARE LIKELY MID TO LATE
AFTERNOON. HIGHS RANGING FROM THE LOWER TEENS TO LOWER 20S.
.LONG TERM...MONDAY NIGHT THROUGH SATURDAY.
SURFACE RIDGE WILL GRADUALLY DRIFT INTO THE FORECAST AREA MONDAY
NIGHT. SUBSTANTIAL DRYING AND STRONG SUBSIDENCE SHOULD PRETTY
MUCH PUT AN END TO ANY LAKE EFFECT SNOW FOR VILAS COUNTY BY EARLY
MONDAY EVENING. JUST KEPT A FEW LINGERING FLURRIES FOR FAR
NORTHERN VILAS BEFORE 06Z THEN DRY THERAFTER. STILL APPEARS MONDAY
NIGHT WILL BE THE COLDEST NIGHT WE HAVE SEEN THIS SEASON WITH MIN
TEMPS EASILY FALLING INTO THE MIDDLE NEGATIVE TEENS ACROSS
NORTHCENTRAL OVERNIGHT GIVEN FRESH SNOW COVER THAT WAS RECEIEIVED EARLY
SUNDAY.
SHORTWAVE DISTURBANCE THEN QUICKLY DIVES SOUTHEAST INTO THE
WESTERN GREAT LAKES BY 00Z WEDNESDAY. AFTER A SUNNY AND COLD
START...WARM ADVECTION AHEAD OF THIS SYSTEM WILL LIKELY BRING IN
SOME MID TO HIGH-LEVEL CLOUDS DURING THE DAY ON TUESDAY. GIVEN THE
COLD START AND INCREASING CLOUDS LATER IN THE DAY...MAX TEMPS WILL
LIKELY NOT BE ABLE RISE MUCH PAST THE MIDDLE TEENS. AS PER
PREVIOUS FORECAST...STILL APPEARS LOW CHANCE POPS ARE WARRANTED
FOR FOR AT LEAST THE NORTHERN HALF OF THE FORECAST AREA. APPEARS
SYSTEM MAY BE A BIT FASTER THAN PREVIOUS MODEL RUNS THUS FOCUSED
HIGHEST POPS IN THE 00Z TO 06Z TIME FRAME. PRECIP AMOUNTS APPEAR
MINIMAL WITH LIGHT SNOW OR SNOW SHOWERS PROVIDING LITTLE IF ANY
ACCUMULATION OVERNIGHT.
DURING THE LATER HALF OF THE WORK WEEK BROAD RIDGE OVER THE
WESTERN CONUS GRADUALLY FLATTENS AND BECOMES MORE ZONAL AS SEVERAL
PIECES OF ENERGY MOVE ONSHORE OVER THE WEST COAST OF THE U.S. THIS
SHOULD LEAD TO A GENERAL BENIGN PERIOD WITH TEMPERATURES AT OR
ABOVE NORMAL STARTING WEDNESDAY...AND MODERATING FURTHER TO NEAR
40 BY WEEKS END. FAIRLY LARGE DESCREPANCY IN THE MEDIUM RANGE
MODELS FOR FRIDAY INTO THE WEEKEND ON SYSTEM MOVING ACROSS
SOUTHERN CANADA. PREFER MUCH WEAKER AND MORE ZONAL-LOOKING
ECMWF/CANADIAN. THUS KEPT FORECAST MAINLY DRY AND LEANED SLIGHTLY
WARMER THAN MODEL BLEND ESPECIALLY FOR SATURDAY.
&&
.AVIATION...STRONG LOW PRESSURE WILL EXIT TOWARDS QUEBEC OVER THE
TAF PERIOD. HOWEVER...PLENTY OF LOW STRATUS AND LIGHT SNOW SHOWERS
UPSTREAM WHICH WILL PLAGUE THE TAF SITES THROUGH AT LEAST THIS
EVENING. SCATTERED SNOW SHOWERS WILL HANG AROUND LONGER AT RHI AS
THE LAKE EFFECT MACHINE CRANKS UP TONIGHT. MAY SEE CIGS REACH LOW
END VFR TONIGHT BASED ON OBS UPSTREAM...BUT PLAYED IT CONSERVATIVE
AND STAYED WITH HIGH END MVFR. PARTIAL CLEARING LOOKS TO OCCUR
MONDAY AFTERNOON. WINDS WILL REMAIN GUSTY THROUGH THE TAF
PERIOD...WITH A FEW GUSTS UP TO 35-40KTS. WIND GUSTS WILL PROBABLY
SETTLE DOWN FOR A PERIOD TONIGHT.
MPC
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR WIZ010>013-018>021-
030-031-035>040-045-048>050-073-074.
WIND ADVISORY UNTIL 6 PM CST MONDAY FOR WIZ022.
WINTER STORM WARNING UNTIL 3 PM CST MONDAY FOR WIZ005.
&&
$$
MPC/ESB
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
304 PM CST SUN JAN 1 2012
.SHORT TERM...TONIGHT THROUGH WEDNESDAY
304 PM CST SUN JAN 1 2012
MAIN FORECAST CONCERNS ARE WINDS THIS EVENING AND PRECIPITATION
CHANCES TONIGHT AS WELL AS TUESDAY EVENING.
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS
SHOWED RIDGING OVER THE WESTERN U.S. INTO SOUTHWEST CANADA...AND
TROUGHING FROM HUDSON BAY SOUTH INTO THE OHIO VALLEY. WITHIN THIS
TROUGH...THE MOST IMPORTANT SHORTWAVES/PV ANOMALIES OF NOTE INCLUDE
ONE OVER SOUTHERN WISCONSIN AND THE OTHER IN SOUTHERN MANITOBA.
NEITHER OF THESE FEATURES ARE PROVIDING MUCH LIFT...NOTED BY
850-700MB AND 500-300MB QG PLOTS. HOWEVER...THEY ARE HELPING TO
LOWER THE TROPOPAUSE AND STEEPEN UP THE LOW TO MID LEVEL LAPSE
RATES. THE LAPSE RATES ARE NOTED BY HAVING 850MB TEMPS AROUND -11C
AT MPX...INL AND BIS...WHICH ARE ADVECTING SOUTHEAST ON 40-60 KT
WINDS PER 12Z RAOBS. WITH STILL PLENTY OF MOISTURE LINGERING IN THE
WAKE OF LAST NIGHTS SYSTEM AND SURFACE TEMPERATURES IN THE MID TO
UPPER 20S F...SCATTERED TO NUMEROUS SNOW SHOWERS COVER MUCH OF
WISCONSIN AND MINNESOTA. THE STEEP LAPSE RATES AND A TIGHT SURFACE
PRESSURE GRADIENT OVER THE FORECAST AREA IS ALSO LEADING TO WINDY
CONDITIONS. FOR THE MOST PART...WIND GUSTS HAVE STAYED BETWEEN 35
AND 50 MPH...STRONGEST SOUTH OF I-90 WHERE SOME SUN OCCURRED
EARLIER TODAY. FOR LOOKING AHEAD TO WHEN SKIES MIGHT CLEAR...BACK
EDGE OF THE STRATUS IS OVER THE FAR EASTERN DAKOTAS...WELL EAST OF
A 1039MB SURFACE HIGH LOCATED OVER EASTERN MONTANA.
TONIGHT AND MONDAY...SHORTWAVE/PV ANOMALY OVER SOUTHERN MANITOBA IS
FORECAST TO DROP SOUTHEAST INTO THE FORECAST AREA AFTER MIDNIGHT
TONIGHT. AGAIN...THIS FEATURE DOES NOT LOOK LIKE IT WILL PROVIDE
MUCH LIFT. HOWEVER...COLDER AIR ASSOCIATED WITH IT...NOTED BY 850MB
TEMPS FALLING TO -16 TO -18C BY 12Z MONDAY...SHOULD HELP TO KEEP THE
LOW LEVEL LAPSE RATES STEEP AND PROVIDE THE OPPORTUNITY FOR AT LEAST
SOME FLURRIES OUT OF THE STRATUS. SINCE THE LAPSE RATES REMAIN STEEP
AND THE PRESSURE GRADIENT REALLY DOES NOT RELAX THAT MUCH FROM
TODAY...EXPECTING GUSTS TO AT LEAST STAY UP IN WIND ADVISORY
CRITERIA THIS EVENING. LOSS OF DAYTIME HEATING MAY HINDER SOME OF
THE DOWNWARD TRANSPORT OF WINDS...SO HAVE NOT EXTENDED THE HAZARDS
BEYOND THE 06Z END TIME. CERTAINLY THE WINDS WILL NEED TO BE
MONITORED THROUGHOUT THE EVENING FOR POSSIBLE EXTENSION OF GOING
HAZARDS. WITH THE COLD ADVECTION...LOOK FOR TEMPERATURES TO CONTINUE
TO FALL THROUGH THE NIGHT...BOTTOMING OUT MOSTLY IN THE TEENS. 500MB
HEIGHT RISES ARE THEN PROGGED FOR MONDAY...ON THE ORDER OF 100-200
METERS BETWEEN 12-00Z...AS THE NORTHERN PART OF THE WESTERN NORTH
AMERICA RIDGING GETS PUSHED EAST. WITH SUCH STRONG SUBSIDENCE
ALOFT...NOT ANTICIPATING MUCH PRECIPITATION. IN FACT...WE SHOULD SEE
CLEARING OF THE STRATUS AS THE HIGH PRESSURE AREA IN EASTERN MONTANA
SHIFTS EAST INTO WESTERN MINNESOTA...BRINGING THE DRY AIR FROM
CANADA WITH AND AHEAD OF IT. 850MB TEMPS DO NOT WARM UP MUCH DURING
THE DAY MONDAY...ONLY TO -14 TO -16C. THEREFORE...MONDAY WILL LIKELY
BE THE COLDEST DAY WE HAVE SEEN IN AWHILE...AND ABOUT 5 DEGREES OR
SO BELOW NORMAL. A BLEND OF GUIDANCE SEEMS REASONABLE AT THIS TIME.
MONDAY NIGHT THROUGH WEDNESDAY...A SHORTWAVE TROUGH...CURRENTLY
SITTING OVER THE EAST PACIFIC...IS PROGGED TO MOVE INTO THE NORTHERN
PLAINS TUESDAY MORNING. THE TROUGH IS THEN WELL AGREED UPON TO DROP
SOUTHEAST ACROSS WISCONSIN TUESDAY EVENING...REPLACING THE BRIEF
PERIOD OF RIDGING THAT WILL HAVE BEEN IN PLACE OVER THE FORECAST
AREA ON TUESDAY. ALTHOUGH DPVA FORCING OCCURS ACROSS THE ENTIRE AREA
LATE TUESDAY INTO TUESDAY EVENING WITH THE SHORTWAVE TROUGH...MUCH
OF THE MOISTURE AND ISENTROPIC LIFT FORCING LOOKS TO STAY NORTH OF
THE FORECAST AREA. HAVE MAINTAINED SOME 20 PERCENT CHANCES FOR
TUESDAY EVENING ALONG AND NORTHEAST OF I-94...SINCE THERE IS SOME
WEAK ISENTROPIC LIFT IN THIS AREA THEN. OTHERWISE...THE ENTIRE TIME
PERIOD IS DOMINATED MOSTLY BY SUBSIDENCE...YIELDING DRY CONDITIONS.
THIS LEAVES CLOUD COVER AND TEMPERATURES THE ONLY CONCERNS. LEFTOVER
STRATUS FROM MONDAY SHOULD QUICKLY CLEAR IN THE EVENING AS THE
SURFACE HIGH MOVES IN. THIS SETS THE STAGE FOR A CHILLY NIGHT...
ESPECIALLY ACROSS WISCONSIN WHERE SNOWPACK EXISTS. BELOW ZERO
READINGS ARE LIKELY THERE. MID AND HIGH CLOUDS WILL THEN BE ON THE
INCREASE FOR TUESDAY AHEAD OF THE APPROACHING SHORTWAVE TROUGH. LOOK
FOR THESE TO CLEAR AFTER MIDNIGHT TUESDAY NIGHT...WITH A BRIEF
PERIOD OF POSSIBLE LOW STRATUS MOVING ACROSS WISCONSIN IN THE COLD
ADVECTION. THIS LOWER STRATUS LOOKS TO CLEAR WEDNESDAY
MORNING...WITH ONLY SOME HIGH CLOUDS POSSIBLE THEREAFTER. A GRADUAL
WARMING TREND IN TEMPERATURES IS FORECAST FOR TUESDAY AND
WEDNESDAY...RESULTING FROM 850MB TEMPS CLIMBING TO -4 TO -8C BY 00Z
WEDNESDAY AND 0 TO -4C BY 00Z THURSDAY. CERTIANLY SNOW FREE AREAS
SUCH AS NORTHEAST IOWA WILL HAVE AN EASIER TIME WARMING UP...WHICH
ALSO HAPPENS TO BE WHERE THE WARMEST 850MB AIR IS PROGGED. A BLEND
OF GUIDANCE STILL LOOKS REASONABLE FOR TEMPERATURES.
.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY
304 PM CST SUN JAN 1 2012
01.12Z ECMWF/GFS/CANADIAN AND GFS ENSEMBLES ARE GENERALLY IN GOOD
AGREEMENT THROUGH THE ENTIRE LONG TERM PERIOD. UPPER RIDGING THAT
HAS BEEN PRESENT OVER THE WESTERN U.S. IS STILL SHOWN TO FLATTEN OUT
AND PUSH EAST...IN RESPONSE TO A FAIRLY POTENT TROUGH COMING INTO
SOUTHWEST CANADA AROUND 00Z FRIDAY. THIS UPPER RIDGING WILL BRING
WITH IT 850MB TEMPS THAT ARE AROUND 2 STANDARD DEVIATIONS ABOVE
NORMAL INTO THE FORECAST AREA FRIDAY MORNING. THE SURFACE WARM FRONT
LEADING THE WARMER AIR LOOKS TO MOVE THROUGH THE AREA THURSDAY
NIGHT. MAY SEE SOME MID AND HIGH CLOUDS AHEAD OF THE WARM FRONT FOR
WEDNESDAY NIGHT AND THURSDAY...BUT NO PRECIPITATION IS ANTICIPATED
DUE TO PLENTY OF LOW LEVEL DRY AIR. COLD FRONT MOVES THROUGH DURING
THE DAY FRIDAY WITH LITTLE FANFARE. THE FRONT WILL BRING IN SOME
COOLER AIR...KNOCKING 850MB TEMPS DOWN FROM THE 8-10C READINGS AT
12Z FRIDAY TO PERHAPS AS COOL AS 2-6C BY 00Z SATURDAY. HOWEVER...THE
FRONT MAY ACTUALLY HELP TO PRODUCE BETTER MIXING. WITH MOSTLY SUNNY
SKIES ANTICIPATED ON FRIDAY...READINGS IN THE 40S ARE LIKELY WITH
50S CERTAINLY NOT OUT OF THE QUESTION. COLDEST READINGS EXPECTED
OVER NORTH CENTRAL WISCONSIN...WHILE WARMEST READINGS WOULD OCCUR
OVER NORTHEAST IOWA.
FOR NEXT WEEKEND...BROAD TROUGHING DEVELOPS FROM THE SOUTHWESTERN
U.S. INTO ONTARIO...WITH SOME INDICATIONS THAT IT MAY SPLIT INTO TWO
PIECES. MUCH OF THIS TROUGHING FORMS FROM THAT POTENT TROUGH...WHICH
IS DIGGING INTO THE NORTHERN PLAINS AND SOUTH CENTRAL CANADA ON
FRIDAY. THIS TROUGHING COMING INTO THE FORECAST AREA WILL ALLOW FOR
COLDER AIR TO MOVE INTO THE AREA. 850MB TEMPS ARE PROGGED TO DROP TO
-6 TO -10C BY 00Z SUNDAY AND AT LEAST -10 TO -14C BY 00Z MONDAY.
NOTE...THE 01.12Z ECMWF NOW SHOWS WARMER CONDITIONS...WITH 850MB
TEMPS ONLY DROPPING TO 0 TO -3C BY 00Z SUNDAY AND -4 TO -8C BY 00Z
MONDAY. THEREFORE...IT IS POSSIBLE THAT THE WEEKEND MIGHT BE A
LITTLE WARMER THAN FORECAST. DESPITE THE COOLING...NOT A LOT OF
MOISTURE LOOKS TO ACCOMPANYING THE TROUGH...SO DRY CONDITIONS ARE
FORECAST AT THIS TIME.
&&
.AVIATION...THROUGH 18Z MONDAY
1120 AM CST SUN JAN 1 2012
STRONG NORTHWEST WINDS AND SCATTERED SNOW SHOWERS WILL
PERSIST THROUGH LATE THIS AFTERNOON. PLAN ON MVFR TO VFR
CONDITIONS WITH CLOUD BASES IN THE 2000 TO 4000 FT RANGE. LOWER
CEILINGS AS THE SNOW SHOWER ACTIVITY MOVES THROUGH. MUCH OF THE
SNOW SHOWER ACTIVITY SHOULD OCCUR AT KLSE. IN ADDITION...VISIBILITIES
MAY BE REDUCED BRIEFLY TO AROUND 2 SM IN ANY SNOW SHOWERS THAT
DEVELOP. LOOK FOR NORTHWEST WINDS AT 20 TO 30 KTS...WITH GUSTS
RANGING FROM 35 TO 45 KTS. THE SNOW SHOWERS AND STRONG WINDS WILL
SUBSIDE THIS EVENING WITH MVFR/VFR CONDITIONS EXPECTED OVERNIGHT.
SCATTERED TO BROKEN STRATUS WILL LINGER ACROSS THE AREA OVERNIGHT
WITH CLOUD BASES OF 2500 TO 3500 FT. LOOK FOR WINDS TO FALL INTO
THE 15 TO 25 KT RANGE TONIGHT WITH GUSTS TO AROUND 30 KTS
POSSIBLE. THE STRATUS IS EXPECTED TO GRADUALLY CLEAR FROM WEST TO
EAST ACROSS THE AREA LATE MONDAY MORNING INTO MONDAY AFTERNOON.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
304 PM CST SUN JAN 1 2012
WI...WIND ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR WIZ017-029-032>034-
041>044-053>055-061.
MN...WIND ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR MNZ079-086>088-
094>096.
IA...WIND ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR IAZ008>011-018-019-
029-030.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...WETENKAMP