Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 11/19/12
AREA FORECAST DISCUSSION
NWS FLAGSTAFF AZ
915 AM MST SAT NOV 17 2012
.SYNOPSIS...INCREASING CLOUDS WILL LEAD TO SCATTERED SHOWERS THIS
AFTERNOON AND EVENING. THE BEST CHANCE FOR SHOWERS WILL BE
THROUGH EASTERN YAVAPAI COUNTY NORTHWARD INTO COCONINO COUNTY THIS
AFTERNOON...MOVING TOWARDS THE FOUR CORNERS THIS EVENING. COOLER AND
DRIER CONDITIONS WILL RETURN SUNDAY...THEN A WARMING TREND THROUGH
NEXT WEEK.
&&
.DISCUSSION...
SATELLITE IMAGERY INDICATES DENSE MID AND HIGH LEVEL CLOUD COVER
SOUTH OF A LINE FROM CHAMBERS THROUGH PAYSON TO YUMA THIS MORNING.
TODAYS SKY COVER GRIDS WERE INCREASED TO MATCH THIS FEATURE.
WE MAY BE INCREASING SHOWER CHANCES TONIGHT NORTH OF INTERSTATE 40
AS THIS IS WHEN THE CALIFORNIA SHORTWAVE MENTION BELOW CROSSES OUR
AREA. STILL EXPECTING ONLY LIGHT PRECIP AMOUNTS.
&&
.PREV DISCUSSION 410 AM...A PRONOUNCED SUB-TROPICAL JET STREAK WILL
MOVE INTO CENTRAL ARIZONA TODAY...AHEAD OF A WEAK S/WV NOW ENTERING
SOUTHERN CALIFORNIA. LOW AND MIDDLE CLOUDS OVER WESTERN ARIZONA
INDICATE THAT LIFT AND MOISTURE LEVELS MAY BE A LITTLE BETTER THAN
MODELS ARE FORECASTING THIS MORNING. THIS MOISTURE WILL BE AIDED BY
IMPROVING DYNAMICS THIS AFTERNOON AS HGHTS FALL AND THE JET STREAK
PLACES CENTRAL AND NORTHERN ARIZONA UNDER MORE FAVORABLE DYNAMICS.
THE RAP13 AND HRRR MODELS SEEM TO BE HANDLING THIS SCENARIO BEST AS
BOTH MODELS GENERATE SHOWERS IN CENTRAL ARIZONA BY THE EARLY
AFTERNOON. THEN...THE BEST FORCING SHIFTS NORTH AND EAST...TOWARD
THE FOUR CORNERS INTO THE EARLY EVENING. DRIER AIR AND SUBSIDENCE
WILL TRAIL THIS WAVE LATER TONIGHT INTO SUNDAY...DESPITE A COLDER
AIRMASS ALOFT. EXPECT POPS TO END BY LATER SUNDAY...WITH WARMING AND
DRY CONDITIONS EXPECTED FOR MUCH OF NEXT WEEK AS RIDGING REDEVELOPS.
&&
..AVIATION...FOR THE 18Z PACKAGE...A WEAK WEATHER DISTURBANCE WILL
BRUSH NORTHERN ARIZONA TODAY AND TONIGHT. THE MAIN IMPACT WILL BE
ISOLATED CEILINGS OF 2-4 KFT AGL OVER THE MOUNTAINS. OTHERWISE...
VFR CONDITIONS WILL PREVAIL UNDER SCATTERED TO BROKEN SKY CONDITIONS
AND A FEW LIGHT SHOWERS. AVIATION SECTION NOT UPDATED FOR AMENDMENTS.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC.........DL / PETERSON
AVIATION.......MCCOLLUM
FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF
AREA FORECAST DISCUSSION
NWS FLAGSTAFF AZ
410 AM MST SAT NOV 17 2012
.SYNOPSIS...INCREASING CLOUDS WILL LEAD TO SCATTERED SHOWERS LATER
TODAY...LASTING INTO THIS EVENING. THE BEST CHANCE FOR SHOWERS WILL
BE THROUGH EASTERN YAVAPAI COUNTY AND NORTHWARD INTO COCONINO COUNTY
THIS AFTERNOON...MOVING TOWARD THE FOUR CORNERS BY THIS EVENING.
COOLER...BUT DRIER CONDITIONS WILL DEVELOP SUNDAY...WITH A WARMING
TREND AND CONTINUED DRY CONDITIONS INTO NEXT WEEK.
&&
.DISCUSSION...A PRONOUNCED SUB-TROPICAL JET STREAK WILL MOVE INTO
CENTRAL ARIZONA TODAY...AHEAD OF A WEAK S/WV NOW ENTERING SOUTHERN
CALIFORNIA. LOW AND MIDDLE CLOUDS OVER WESTERN ARIZONA INDICATE THAT
LIFT AND MOISTURE LEVELS MAY BE A LITTLE BETTER THAN MODELS ARE
FORECASTING THIS MORNING. THIS MOISTURE WILL BE AIDED BY IMPROVING
DYNAMICS THIS AFTERNOON AS HGHTS FALL AND THE JET STREAK PLACES
CENTRAL AND NORTHERN ARIZONA UNDER MORE FAVORABLE DYNAMICS. THE
RAP13 AND HRRR MODELS SEEM TO BE HANDLING THIS SCENARIO BEST AS BOTH
MODELS GENERATE SHOWERS IN CENTRAL ARIZONA BY THE EARLY AFTERNOON.
THEN...THE BEST FORCING SHIFTS NORTH AND EAST...TOWARD THE FOUR
CORNERS INTO THE EARLY EVENING. DRIER AIR AND SUBSIDENCE WILL TRAIL
THIS WAVE LATER TONIGHT INTO SUNDAY...DESPITE A COLDER AIRMASS
ALOFT. EXPECT POPS TO END BY LATER SUNDAY...WITH WARMING AND DRY
CONDITIONS EXPECTED FOR MUCH OF NEXT WEEK AS RIDGING REDEVELOPS.
&&
.AVIATION....AVIATION...FOR THE 12Z PACKAGE...VFR AND ISOLATED MVFR
CONDITIONS ARE EXPECTED. SCT-BKN CLOUDS ARE FORECAST WITH A FEW
LIGHT SHOWERS TODAY AND TONIGHT...MAINLY OVER THE HIGHER ELEVATIONS.
AVIATION SECTION NOT UPDATED FOR AMENDMENTS.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC.........PETERSON
AVIATION.......BOHLIN
FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
1040 AM EST SAT NOV 17 2012
.DISCUSSION...
MID LEVEL REX BLOCKING PATTERN EXTENDING FROM THE GREAT LAKES TO THE
ERN GOMEX THIS MORNING. CUT-OFF H85-H50 LOW OVER THE DEEP SOUTH/ERN
GOMEX WILL REMAIN NEARLY STATIONARY THIS AFTN...KEEPING THE FL
PENINSULA ON ITS ASCENDING ERN FLANK. IN THE H100-H70 LYR...A LARGE
ANTICYCLONE EXTENDING FROM THE ST. LAWRENCE SEAWAY TO THE RIO GRANDE
VALLEY WILL COMBINE WITH AN INVERTED TROF E OF THE FL PENINSULA TO
GENERATE A STEADY NE BREEZE ACRS CENTRAL FL.
MORNING SOUNDINGS SHOW MODEST PWATS OF 1.1"-1.3" ACRS CENTRAL/S
FL...DECREASING TO 0.9" AT KJAX...NEARLY SATURATED THRU THE H100-H75
LYR. KXMR HAD A LOW LVL DRY SLUG...CONFIRMED BY LATEST RAP RH
ANALYSIS THRU THE H100-H70 LYR. KTBW/KXMR TEMP TREND OVER THE PAST
24HRS REVEALS MODERATE CAA ABV H80...WEAK WAA BLO H80...CONVECTIVE
TRIGGER TEMP ARND 80F AT KXMR.
THE LATTER MAY BE DIFFICULT TO REACH GIVEN THE DEEP E/NE FLOW.
HOWEVER...GIVEN THE POSITION OF THE MID LVL TROF OVER THE GOMEX...
MID/UPR LVL DYNAMIC SUPPORT MAY BE JUST STRONG ENOUGH TO COMPENSATE
FOR THE LACK OF SFC HEATING. INDEED...ISENTROPIC ANALYSIS SHOWS
STRONG LIFT OCCURRING ACRS THE NRN/WRN PENINSULA...WEAK TO MODERATE
OVER THE SRN PENINSULA. THIS MATCHES UP WELL WITH THE CURRENT POP
CONFIGURATION. MORNING UPDATES MAINLY TO REFRESH THE TEXT...NO
SUBSTANTIVE CHANGES NECESSARY.
&&
.AVIATION...
VFR ALL SITES UNLESS OTHERWISE NOTED. BTWN 17/18Z-17/24Z...SCT MVFR
SHRAS/ISOLD IFR TSRAS...MAINLY N OF KVRB/KISM. BTWN 18/00Z-18/03Z...
SHRA/TSRAS ENDING INTERIOR SITES...CONTG THRU 18/12Z COASTAL SITES N
OF KMLB.
&&
.MARINE...
LATEST OBS FROM BUOY SHOWING FULL BLOWN SCA WINDS/SEAS...
DIMINISHING TO SCA SEAS AT BUOY...NEARSHORE SCRIPPS BUOYS
MEASURING SEAS IN THE 4-6FT RANGE. INVERTED TROF JUST E OF THE LCL
ATLC WILL GENERATE A MODERATE TO FRESH NE BREEZE N OF SEBASTIAN
INLET...GENTLE TO MODERATE S OF THE INLET. CURRENT SCA CONFIGURATION
LOOKS GOOD...NO SIG CHANGES NECESSARY.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY UNTIL 10 PM EST SUNDAY FOR COASTAL WATERS
FROM FLAGLER BEACH TO VOLUSIA BREVARD COUNTY LINE OUT 20 NM-
COASTAL WATERS FROM VOLUSIA BREVARD COUNTY LINE TO
SEBASTIAN INLET OUT 20 NM-WATERS FROM FLAGLER BEACH TO
VOLUSIA BREVARD COUNTY LINE 20 TO 60 NM OFFSHORE-WATERS
FROM VOLUSIA BREVARD COUNTY LINE TO SEBASTIAN INLET 20 TO
60 NM OFFSHORE.
&&
$$
SHORT TERM/AVIATION...BRAGAW
LONG TERM/IMPACT WX...GLITTO
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1006 AM MST SAT NOV 17 2012
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 151 AM MST SAT NOV 17 2012
05Z WATER VAPOR IMAGERY RUC ANALYSIS INDICATED RIDGE AXIS IN PLACE
ACROSS THE MISSOURI VALLEY WITH STRONG SHORT WAVE TROUGH NEARING THE
PAC NORTHWEST. 00Z SOUNDINGS INDICATED A FAIRLY LARGE DIFFERENCE IN
THE LARGE SCALE AIR MASS BETWEEN DNR AND LBF/DDC. AT
LBF/DDC...STRONG INVERSION WAS NOTED BETWEEN H8 AND H7 MAKING
OVERALL AIR MASS VERY STABLE. IN ADDITION TO THE STABLE
LAYER...MIXING RATIOS INDICATED A FAIRLY DEEP MOIST LAYER ENDING
AROUND H8. AT DNR...NEARLY DRY ADIABATIC LAPSE RATES NOTED BETWEEN
H75 AND H55 WITH MIXING RATIOS DROPPING RAPIDLY ABOVE THE SFC LAYER.
AT THE SFC...TROUGH AXIS WAS LOCATED ACROSS EASTERN COLORADO.
TODAY-TOMORROW...SEVERAL WEAK/LOW AMPLITUDE SHORT WAVE TROUGHS WILL
MOVE ACROSS THE REGION THROUGH THE PERIOD EACH BRINGING A BRIEF
PERIOD OF FORCED ASCENT ACROSS THE CWA. FOR THE MOST PART...SEEMS
UNLIKELY THAT LIFT WELL BE ABLE TO SATURATE AND NEAR SFC OR MID
LEVEL LAYERS THROUGH TONIGHT AND WHILE ELEVATED THETA E LAPSE RATES
SUPPORT THE POSSIBILITY OF POTENTIAL INSTABILITY...THINK VERTICAL
MOISTURE PROFILES MAKE THIS VERY UNLIKELY. MODELS DIVERGE A BIT MORE
ON SUNDAY WITH HANDLING OF NEXT TROUGH WHICH WILL PROVIDE NOTICEABLY
STRONGER FORCING AS IT MORE DIRECTLY MOVES OVER CWA. MAJORITY OF
MODELS AND GEFS ENSEMBLES SUPPORT PRECIPITATION THREAT ACROSS
EASTERN KANSAS...WHILE NAM AND SREF SUGGESTING POCKET OF ELEVATED
CAPE WILL DEVELOP ACROSS SOUTHEASTERN CWA AS TROUGH PASSES. BASED ON
MODEL CONSENSUS WILL WEIGHT FORECAST MORE TOWARDS THE EASTERN KS
SOLUTIONS...BUT DID UP POPS TO AROUND 10 PERCENT IN THE EAST SINCE
LAPSE RATES WOULD SUPPORT INSTABILITY DEVELOPMENT SHOULD ANY
MEANINGFUL MOISTURE ADVECTION OCCUR. THE OTHER POTENTIAL FOR SENSIBLE
WEATHER WILL BE THE THREAT OF FOG/STRATUS EARLY THIS MORNING AND
AGAIN SUNDAY MORNING. WITH WINDS STAYING IN THE 5 TO 10 KT RANGE
AHEAD OF SFC TROUGH...NOT REALLY CONFIDENT IN FOG FORMATION. HOWEVER
BASED ON OBSERVED SOUNDINGS SHOWING A FAIRLY DEEP NEAR SFC MOIST
LAYER...WILL LEAVE A PATCHY MENTION IN AREAS MOST LIKELY TO DECOUPLE.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 151 AM MST SAT NOV 17 2012
SUNDAY NIGHT-MONDAY NIGHT...ZONAL FLOW ALOFT WILL GRADUALLY SHIFT
TO SHORT WAVE RIDGING TOWARDS THE END OF THE PERIOD...WITH DRY AND
OVERALL QUIET CONDITIONS EXPECTED TO CONTINUE. TEMPERATURES WILL
GRADUALLY WARM THROUGH THE PERIOD...WITH A FEW LOCATIONS NEARING
70 BY MONDAY.
TUESDAY-FRIDAY...
PROGRESSIVE ZONAL PATTERN WITH MAIN STORM TRACK WELL NORTH OF CWA
ALONG CANADIAN BORDER AND WEAKER SOUTHERN TRACK ACROSS SOUTHERN
PLAINS IS EXPECTED THROUGH THE EXTENDED PERIOD. RESULT OF THIS
PATTERN WILL BE ABOVE NORMAL TEMPERATURES AND DRY CONDITIONS
PERSISTING OVER THE CWA. A SHORTWAVE RIDGE BEGINS TO BUILD INTO THE
INTER-MOUNTAIN WEST TUESDAY AND THEN ACROSS THE PLAINS ON
WEDNESDAY...WHEN HIGH TEMPS IN THE UPPER 60S/NEAR 70 ARE EXPECTED.
RH VALUES ON WEDNESDAY COULD APPROACH CRITICAL LEVELS...HOWEVER
WINDS SHOULD REMAIN WELL BELOW RED FLAG CRITERIA. WHILE THERE WILL
BE A SLIGHTLY COOLER AIR MASS BEHIND A WEAK COLD FRONT WE SHOULD
STILL SEE ABOVE NORMAL TEMPS THURSDAY AND FRIDAY WITH HIGHS IN THE
UPPER 50S/LOW 60S AND LOWS IN THE 30S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1004 AM MST SAT NOV 17 2012
VFR EXPECTED AT BOTH KGLD AND KMCK THROUGH 06Z TONIGHT. AFTER THAT
TIME...PATCHY FOG EXPECTED TO DEVELOP ONCE AGAIN TOWARDS SUNRISE
SUNDAY MORNING WITH LIGHT WINDS AND CLEAR SKIES. TEMPORARY
VISIBILITY REDUCTIONS MAY OCCUR AT EITHER SITE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...JRM
LONG TERM...JRM/DR
AVIATION...024
AREA FORECAST DISCUSSION
NWS GOODLAND KS
420 AM MST SAT NOV 17 2012
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 151 AM MST SAT NOV 17 2012
05Z WATER VAPOR IMAGERY RUC ANALYSIS INDICATED RIDGE AXIS IN PLACE
ACROSS THE MISSOURI VALLEY WITH STRONG SHORT WAVE TROUGH NEARING THE
PAC NORTHWEST. 00Z SOUNDINGS INDICATED A FAIRLY LARGE DIFFERENCE IN
THE LARGE SCALE AIR MASS BETWEEN DNR AND LBF/DDC. AT
LBF/DDC...STRONG INVERSION WAS NOTED BETWEEN H8 AND H7 MAKING
OVERALL AIR MASS VERY STABLE. IN ADDITION TO THE STABLE
LAYER...MIXING RATIOS INDICATED A FAIRLY DEEP MOIST LAYER ENDING
AROUND H8. AT DNR...NEARLY DRY ADIABATIC LAPSE RATES NOTED BETWEEN
H75 AND H55 WITH MIXING RATIOS DROPPING RAPIDLY ABOVE THE SFC LAYER.
AT THE SFC...TROUGH AXIS WAS LOCATED ACROSS EASTERN COLORADO.
TODAY-TOMORROW...SEVERAL WEAK/LOW AMPLITUDE SHORT WAVE TROUGHS WILL
MOVE ACROSS THE REGION THROUGH THE PERIOD EACH BRINGING A BRIEF
PERIOD OF FORCED ASCENT ACROSS THE CWA. FOR THE MOST PART...SEEMS
UNLIKELY THAT LIFT WELL BE ABLE TO SATURATE AND NEAR SFC OR MID
LEVEL LAYERS THROUGH TONIGHT AND WHILE ELEVATED THETA E LAPSE RATES
SUPPORT THE POSSIBILITY OF POTENTIAL INSTABILITY...THINK VERTICAL
MOISTURE PROFILES MAKE THIS VERY UNLIKELY. MODELS DIVERGE A BIT MORE
ON SUNDAY WITH HANDLING OF NEXT TROUGH WHICH WILL PROVIDE NOTICEABLY
STRONGER FORCING AS IT MORE DIRECTLY MOVES OVER CWA. MAJORITY OF
MODELS AND GEFS ENSEMBLES SUPPORT PRECIPITATION THREAT ACROSS
EASTERN KANSAS...WHILE NAM AND SREF SUGGESTING POCKET OF ELEVATED
CAPE WILL DEVELOP ACROSS SOUTHEASTERN CWA AS TROUGH PASSES. BASED ON
MODEL CONSENSUS WILL WEIGHT FORECAST MORE TOWARDS THE EASTERN KS
SOLUTIONS...BUT DID UP POPS TO AROUND 10 PERCENT IN THE EAST SINCE
LAPSE RATES WOULD SUPPORT INSTABILITY DEVELOPMENT SHOULD ANY
MEANINGFUL MOISTURE ADVECTION OCCUR. THE OTHER POTENTIAL FOR SENSIBLE
WEATHER WILL BE THE THREAT OF FOG/STRATUS EARLY THIS MORNING AND
AGAIN SUNDAY MORNING. WITH WINDS STAYING IN THE 5 TO 10 KT RANGE
AHEAD OF SFC TROUGH...NOT REALLY CONFIDENT IN FOG FORMATION. HOWEVER
BASED ON OBSERVED SOUNDINGS SHOWING A FAIRLY DEEP NEAR SFC MOIST
LAYER...WILL LEAVE A PATCHY MENTION IN AREAS MOST LIKELY TO DECOUPLE.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 151 AM MST SAT NOV 17 2012
SUNDAY NIGHT-MONDAY NIGHT...ZONAL FLOW ALOFT WILL GRADUALLY SHIFT
TO SHORT WAVE RIDGING TOWARDS THE END OF THE PERIOD...WITH DRY AND
OVERALL QUIET CONDITIONS EXPECTED TO CONTINUE. TEMPERATURES WILL
GRADUALLY WARM THROUGH THE PERIOD...WITH A FEW LOCATIONS NEARING
70 BY MONDAY.
TUESDAY-FRIDAY...
PROGRESSIVE ZONAL PATTERN WITH MAIN STORM TRACK WELL NORTH OF CWA
ALONG CANADIAN BORDER AND WEAKER SOUTHERN TRACK ACROSS SOUTHERN
PLAINS IS EXPECTED THROUGH THE EXTENDED PERIOD. RESULT OF THIS
PATTERN WILL BE ABOVE NORMAL TEMPERATURES AND DRY CONDITIONS
PERSISTING OVER THE CWA. A SHORTWAVE RIDGE BEGINS TO BUILD INTO THE
INTER-MOUNTAIN WEST TUESDAY AND THEN ACROSS THE PLAINS ON
WEDNESDAY...WHEN HIGH TEMPS IN THE UPPER 60S/NEAR 70 ARE EXPECTED.
RH VALUES ON WEDNESDAY COULD APPROACH CRITICAL LEVELS...HOWEVER
WINDS SHOULD REMAIN WELL BELOW RED FLAG CRITERIA. WHILE THERE WILL
BE A SLIGHTLY COOLER AIR MASS BEHIND A WEAK COLD FRONT WE SHOULD
STILL SEE ABOVE NORMAL TEMPS THURSDAY AND FRIDAY WITH HIGHS IN THE
UPPER 50S/LOW 60S AND LOWS IN THE 30S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 411 AM MST SAT NOV 17 2012
MAIN FORECAST CONCERN FOR THE PERIOD WILL BE FOG POTENTIAL THIS
MORNING AND TOMORROW MORNING...ESPECIALLY AT MCK. 00Z SOUNDINGS
INDICATED A DEEP NEAR SFC MOIST LAYER IN PLACE ACROSS THE AREA AND
WITH WINDS DECOUPLING...SKIES CLEARING AND COOLER AIR WORKING ITS
WAY DOWN THE REPUBLICAN RIVER VALLEY...A PERIOD OF REDUCED FLIGHT
CATEGORIES POSSIBLE. NOT INCREDIBLY CONFIDENT IN VISIBILITY
REDUCTIONS...BUT THINK INCLUDING AN OPERATIONALLY SIGNIFICANT
CATEGORY APPROPRIATE. SIMILAR SET UP TOMORROW NIGHT WITH PERIOD OF
LIGHT WINDS AND MOSTLY CLEAR SKIES ALONG THE KANSAS AND NEBRASKA
BORDER. WITH NO AIR MASS CHANGE EXPECTED...THINK FOG POTENTIAL
WILL INCREASE IN SIMILAR AREA AFTER 09Z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...JRM
LONG TERM...JRM/DR
AVIATION...JRM
AREA FORECAST DISCUSSION
NWS GOODLAND KS
155 AM MST SAT NOV 17 2012
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 151 AM MST SAT NOV 17 2012
05Z WATER VAPOR IMAGERY RUC ANALYSIS INDICATED RIDGE AXIS IN PLACE
ACROSS THE MISSOURI VALLEY WITH STRONG SHORT WAVE TROUGH NEARING THE
PAC NORTHWEST. 00Z SOUNDINGS INDICATED A FAIRLY LARGE DIFFERENCE IN
THE LARGE SCALE AIR MASS BETWEEN DNR AND LBF/DDC. AT
LBF/DDC...STRONG INVERSION WAS NOTED BETWEEN H8 AND H7 MAKING
OVERALL AIR MASS VERY STABLE. IN ADDITION TO THE STABLE
LAYER...MIXING RATIOS INDICATED A FAIRLY DEEP MOIST LAYER ENDING
AROUND H8. AT DNR...NEARLY DRY ADIABATIC LAPSE RATES NOTED BETWEEN
H75 AND H55 WITH MIXING RATIOS DROPPING RAPIDLY ABOVE THE SFC LAYER.
AT THE SFC...TROUGH AXIS WAS LOCATED ACROSS EASTERN COLORADO.
TODAY-TOMORROW...SEVERAL WEAK/LOW AMPLITUDE SHORT WAVE TROUGHS WILL
MOVE ACROSS THE REGION THROUGH THE PERIOD EACH BRINGING A BRIEF
PERIOD OF FORCED ASCENT ACROSS THE CWA. FOR THE MOST PART...SEEMS
UNLIKELY THAT LIFT WELL BE ABLE TO SATURATE AND NEAR SFC OR MID
LEVEL LAYERS THROUGH TONIGHT AND WHILE ELEVATED THETA E LAPSE RATES
SUPPORT THE POSSIBILITY OF POTENTIAL INSTABILITY...THINK VERTICAL
MOISTURE PROFILES MAKE THIS VERY UNLIKELY. MODELS DIVERGE A BIT MORE
ON SUNDAY WITH HANDLING OF NEXT TROUGH WHICH WILL PROVIDE NOTICEABLY
STRONGER FORCING AS IT MORE DIRECTLY MOVES OVER CWA. MAJORITY OF
MODELS AND GEFS ENSEMBLES SUPPORT PRECIPITATION THREAT ACROSS
EASTERN KANSAS...WHILE NAM AND SREF SUGGESTING POCKET OF ELEVATED
CAPE WILL DEVELOP ACROSS SOUTHEASTERN CWA AS TROUGH PASSES. BASED ON
MODEL CONSENSUS WILL WEIGHT FORECAST MORE TOWARDS THE EASTERN KS
SOLUTIONS...BUT DID UP POPS TO AROUND 10 PERCENT IN THE EAST SINCE
LAPSE RATES WOULD SUPPORT INSTABILITY DEVELOPMENT SHOULD ANY
MEANINGFUL MOISTURE ADVECTION OCCUR. THE OTHER POTENTIAL FOR SENSIBLE
WEATHER WILL BE THE THREAT OF FOG/STRATUS EARLY THIS MORNING AND
AGAIN SUNDAY MORNING. WITH WINDS STAYING IN THE 5 TO 10 KT RANGE
AHEAD OF SFC TROUGH...NOT REALLY CONFIDENT IN FOG FORMATION. HOWEVER
BASED ON OBSERVED SOUNDINGS SHOWING A FAIRLY DEEP NEAR SFC MOIST
LAYER...WILL LEAVE A PATCHY MENTION IN AREAS MOST LIKELY TO DECOUPLE.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 151 AM MST SAT NOV 17 2012
SUNDAY NIGHT-MONDAY NIGHT...ZONAL FLOW ALOFT WILL GRADUALLY SHIFT
TO SHORT WAVE RIDGING TOWARDS THE END OF THE PERIOD...WITH DRY AND
OVERALL QUIET CONDITIONS EXPECTED TO CONTINUE. TEMPERATURES WILL
GRADUALLY WARM THROUGH THE PERIOD...WITH A FEW LOCATIONS NEARING
70 BY MONDAY.
TUESDAY-FRIDAY...
PROGRESSIVE ZONAL PATTERN WITH MAIN STORM TRACK WELL NORTH OF CWA
ALONG CANADIAN BORDER AND WEAKER SOUTHERN TRACK ACROSS SOUTHERN
PLAINS IS EXPECTED THROUGH THE EXTENDED PERIOD. RESULT OF THIS
PATTERN WILL BE ABOVE NORMAL TEMPERATURES AND DRY CONDITIONS
PERSISTING OVER THE CWA. A SHORTWAVE RIDGE BEGINS TO BUILD INTO THE
INTER-MOUNTAIN WEST TUESDAY AND THEN ACROSS THE PLAINS ON
WEDNESDAY...WHEN HIGH TEMPS IN THE UPPER 60S/NEAR 70 ARE EXPECTED.
RH VALUES ON WEDNESDAY COULD APPROACH CRITICAL LEVELS...HOWEVER
WINDS SHOULD REMAIN WELL BELOW RED FLAG CRITERIA. WHILE THERE WILL
BE A SLIGHTLY COOLER AIR MASS BEHIND A WEAK COLD FRONT WE SHOULD
STILL SEE ABOVE NORMAL TEMPS THURSDAY AND FRIDAY WITH HIGHS IN THE
UPPER 50S/LOW 60S AND LOWS IN THE 30S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1000 PM MST FRI NOV 16 2012
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD AT KGLD WITH
MVFR/POSSIBLY IFR AT KMCK. A NARROW NEARLY NORTH TO SOUTH RIBBON
OF PATCHY FOG/STRATUS IS EXPECTED TO DEVELOP IN SOUTHWESTERN
NEBRASKA SOUTHWARD EARLY SATURDAY MORNING...WHICH MAY CAUSE MVFR/IFR
VISIBILITIES AT KMCK. OTHERWISE...A FEW MID TO HIGH LEVEL CLOUDS
THROUGH THE PERIOD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...JRM
LONG TERM...JRM/DR
AVIATION...99
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
516 PM CST Sun Nov 18 2012
...UPDATED AVIATION DISCUSSION...
.DISCUSSION...
Tonight - Monday:
The main challenges through this period are the timing/onset of
precipitation and the duration into the Monday period. Water vapor
imagery was showing the weak upper level disturbance moving out of
the Southern Rockies and into the Plains. Radar and visible/IR
imagery show what also may be a weak baroclinic zone across south
central to eastern Nebraska with a few light returns showing up on
radar. The GFS does indicate a slightly tighter theta-e gradient
aloft through this area. The radar returns are consistent with the
latest HRRR run, albeit a few hours delayed, which develops
precipitation in this area this afternoon. Precipitation should
increase in coverage across the eastern half of Kansas this evening
as the support from the upper wave moves into the region. Think that
the timing of precipitation in our western zones will be in the 2-3Z
window and persist for 4-6 hours as the whole area moves into our
eastern zones. It still looks like coverage will be in the 50% range
and precipitation totals will be less than a quarter inch for those
that do pick up rain. Precipitation still looks to be coming to end
by mid day Monday. There could potentially be a few sprinkles Monday
afternoon as another weak wave will be tracking into the area. But
models are in good agreement moving any QPF away from the area
during the afternoon so the chances of precipitation look too small
to mention at this time.
High temperatures on Monday will be restrained a bit in our eastern
zones as cloud cover will be exiting the area preventing a warm up
like our western zones are expected to see. Overall, highs will
range from the low to mid 60s in our west to the middle 50s in our
east.
Tuesday - Tuesday Night:
Quiet weather with above normal temperatures are expected this
period. High temperatures should climb into the 60s across the area
but may be inhibited by weak flow and limited mixing. Overnight lows
should be mild for this time of year with lows generally in the low
to mid 40s. With light winds overnight, some of our typical low
lying/ drainage areas may fall into the 30s.
CDB
Wednesday - Sunday:
Model consensus is a continuation of near to above average
temperatures during this period with little in the way of
precipitation. Travel day on Wednesday looks outstanding with
temperatures nearing the 70 degree mark possible in the far western
CWA.
Most of the focus is on Thursday/Thanksgiving. An upper level ridge
will exit the region on Wednesday as another impulse within the
southern stream lifts northeast from the Southern Rockies on
Thanksgiving. Despite a lack of low level moisture there is
increasing support from the GFS and ECMWF that sufficient mid level
Pacific moisture will be available for scattered light showers as a
weak cold front drops southeast through MO Thursday night. Have
nudged Thursday night pops up to chance category for the far
southern counties.
A large vortex over the Gulf of Alaska is expected to eject a
significant piece of energy eastward at the start of the period. The
resulting shortwave trough will dig/deepen southeast through the
Upper MS Valley and Great Lakes Thursday night/Friday. Any weather
with this feature will track to the north but a secondary cold front
will pass through on Friday and reinforce an intrusion of colder
air. Have gone along with model consensus on temperatures but the
trend is towards more cooling and can envision later forecasts
tweaking Friday`s temperatures downward some more.
Zonal flow through the mid levels and warm air advection in the
boundary layer will return for the dry weekend.
MJ
&&
.AVIATION...
As the upper wave moves across the area tonight it should produce
scattered showers. The duration of the showers should be brief, and
it is doubtful that cigs or vsbys will drop below VFR. Showers should
be long gone by Monday morning.
Bailey
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
WFO EAX
AREA FORECAST DISCUSSION
NWS HASTINGS NE
554 PM CST SUN NOV 18 2012
.AVIATION...00Z KGRI TAF. VFR CONDITIONS WILL CONTINUE AT THE
TERMINAL FOR THE NEXT 24 HOURS. EXPECT SOUTHERLY WINDS NEAR 10KTS
THIS EVENING TO BECOME LIGHT AND VARIABLE OVERNIGHT AS A SURFACE
TROUGH TO THE WEST NUDGES EASTWARD. AS THIS TROUGH SHIFTS FURTHER EAST
ON MONDAY...WINDS WILL EVENTUALLY BECOME WEST TO NORTHWESTERLY
AFT 19/13Z. OTHER THAN A FEW HIGH CLOUDS THIS EVENING...SKIES ARE
EXPECTED TO BE CLEAR THE REMAINDER OF THE TAF PERIOD.
&&
.PREV DISCUSSION... /ISSUED 305 PM CST SUN NOV 18 2012/
SHORT TERM...THROUGH MONDAY AFTERNOON. OVERALL THE BENIGN WEATHER
PATTERN OF LATE CONTINUES THROUGH THE NEXT 24 HOURS...WITH THE
MAIN FAIRLY MINOR ISSUE CONSISTING OF THE POSSIBILITY OF SPRINKLES
ACROSS SOUTHEAST ZONES LATE THIS AFTERNOON INTO THIS EVENING.
20Z OBJECTIVE SURFACE ANALYSIS PLACES A GENERALLY NORTH-SOUTH
TROUGH AXIS RUNNING FROM WESTERN SD THROUGH THE NEB PANHANDLE AND
DOWN ALONG THE KS/CO BORDER...TRAILING SOUTH FROM A 1005MB LOW AT
THE WY/MT/SD INTERSECTION. MEANWHILE...AN EXPANSIVE RIDGE AXIS
CONTINUES TO DOMINATE MUCH OF THE EASTERN CONUS. THE CWA LIES
ALONG THE INTERFACE BETWEEN THESE TWO FEATURES...WITH A MODEST
PRESSURE GRADIENT AND DIURNAL MIXING GENERALLY INTO THE 900-875MB
RANGE DRIVING SOUTHERLY SUSTAINED BREEZES TYPICALLY 13-23 MPH WITH
GUSTS MAINLY 20-25 MPH. VISIBLE SATELLITE CONFIRMS A RATHER
HEALTHY COVERAGE OF MID-HIGH CLOUDS STREAMING
OVERHEAD...ESPECIALLY ACROSS THE SOUTHEAST 2/3 OF THE CWA. RADAR
EVEN SUGGESTS A FEW SPRINKLES MAY HAVE ALREADY FALLEN THIS
AFTERNOON ACROSS PARTS OF NUCKOLLS/THAYER/FILLMORE COUNTIES. THESE
CLOUDS SEEM TO BE HAVING A VARYING EFFECT ON TEMPS THIS
AFTERNOON...WITH BOTH KS ZONES AND NORTHERN ZONES IN NEB VERY MUCH
ON TRACK TO NEAR FORECAST HIGHS IN THE LOW-MID 60S...WHILE CENTRAL
AREAS INCLUDING THE TRI-CITIES MAY FALL A BIT SHORT AND STRUGGLE
TO REACH 60. THE CLOUDS HAVE LIKELY ALSO REDUCED MIXING SOMEWHAT
AND HELD DOWN WIND SPEEDS SLIGHTLY. WATER VAPOR IMAGERY AND SHORT
TERM MODEL DATA DEPICTS BROAD QUASI-ZONAL/SLIGHTLY SOUTHWESTERLY
FLOW ACROSS THE CENTRAL/WESTERN CONUS...WITH A PAIR OF FAIRLY
VIGOROUS SHORTWAVE TROUGHS TRANSLATING THROUGH THE NORTHERN
ROCKIES AND OFF THE PACIFIC NORTHWEST COAST. CLOSER TO HOME...A
MORE SUBTLE LOW AMPLITUDE MID LEVEL WAVE IS CURRENTLY LIFTING OUT
OF CO/WY...INTO NEB/KS...WITH THE MID-HIGH CLOUDS STREAMING OUT
AHEAD OF THIS WAVE LARGELY ASSOCIATED WITH A MODEST 70+KT 300MB
JET STREAK.
LATE THIS AFTERNOON INTO THIS EVENING...THIS LOW AMPLITUDE MID
LEVEL WAVE WILL CONTINUE TRACKING ACROSS THE HEART OF THE CENTRAL
PLAINS...WITH THE ONGOING BATCH OF MID-HIGH CLOUDS GRADUALLY
CLEARING THE CWA FROM WEST-EAST AND PAVING THE WAY FOR A CLEAR
OVERNIGHT. PRIOR TO THIS HOWEVER...THE MOISTURE-STARVED
DISTURBANCE WILL CONTINUE TO PROMOTE MODEST THETA-E ADVECTION
EVIDENT IN THE 850-700MB LAYER MAINLY OVER THE EASTERN HALVES OF
NEB/KS. DESPITE PLENTIFUL DRY AIR ESPECIALLY BELOW 700MB...WILL
MAINTAIN A CHANCE OF SPRINKLES THROUGH 10 PM FOR LOCATIONS
GENERALLY EAST OF A LINE FROM YORK-NELSON-OSBORNE...WITH
ESSENTIALLY ZERO RISK OF PRECIP ACROSS THE REMAINDER OF THE CWA.
DESPITE VARIOUS MODELS SUCH AS THE NAM/ECMWF/GFS KEEPING ALL QPF
EAST OF THE CWA INTO THIS EVENING...THE WEAK RADAR RETURNS ALREADY
OBSERVED WITHIN THE FAR SOUTHEAST CWA THIS AFTERNOON ALONG WITH
THE 1KM REFLECTIVITY PROGS FROM THE LATEST HRRR MAKE ME UNWILLING
TO COMPLETELY IGNORE SPRINKLE POTENTIAL...ALTHOUGH AGREE WITH
PREVIOUS FORECASTER THAT ANYTHING MEASURABLE SHOULD FOCUS WELL
EAST/SOUTHEAST OF THE LOCAL AREA. AS MENTIONED...THE OVERNIGHT
WILL FEATURE CLEAR SKIES...WHILE AT THE SURFACE...A WEAK TROUGH
WILL MOVE EASTWARD ACROSS MAINLY THE WESTERN 1/2 OF THE
CWA...TURNING LIGHT BREEZES NORTHWESTERLY IN ITS WAKE. TEMPS
OVERNIGHT COULD BE A BIT TRICKY...AS THE NORTHWEST COMPONENT
BEHIND THE SURFACE TROUGH COULD ACT TO HOLD THINGS UP...WHILE JUST
AHEAD OF THE TROUGH THE COMBINATION OF NEAR-CALM TO LIGHT
SOUTHERLY BREEZES AND CLEAR SKIES SHOULD PROMOTE AN EFFICIENT
DROP. FEEL THAT A BLEND OF 12Z MET/MAV GUIDANCE IS PROBABLY THE
BEST COMPROMISE...AND THUS WILL LOWER MOST OF THE CWA 2-3 DEGREES
FROM PREVIOUS FORECAST...BUT STILL KEEPING ALL BUT A FEW NORTHWEST
COUNTIES ABOVE FREEZING AND IN THE 33-37 RANGE. ALTHOUGH SUPPOSE
SOME HAZE OR LIGHT FOG IS NOT OUT OF THE QUESTION AROUND SUNRISE
ESPECIALLY ALONG THE TROUGH AXIS...AM NOT EXPECTING FOG TO BE
WORTHY OF A FORMAL MENTION IN THE FORECAST.
FOR THE MONDAY DAYTIME PERIOD...TRANQUIL...MOISTURE-STARVED QUASI-
ZONAL FLOW WILL CONTINUE ALOFT OVER THE CENTRAL PLAINS...AS THE
SHORTWAVE CURRENTLY AFFECTING THE AREA MOVES WELL OFF EAST TOWARD
THE GREAT LAKES...WHILE THE SOUTHERN FRINGES OF ANOTHER MID LEVEL
WAVE CENTERED OVER THE CANADIAN BORDER BRUSHES INTO WESTERN NEB
DURING THE AFTERNOON. WHILE THE MAJORITY OF THE DAY SHOULD REMAIN
QUITE SUNNY WITH ONLY A FEW PASSING SPLOTCHES OF HIGH CIRRUS...THE
MID-LATE AFTERNOON HOURS COULD FEATURE A BIT GREATER INCOMING
CIRRUS COVERAGE MAINLY OVER NORTHWEST ZONES ASSOCIATED WITH THE
APPROACHING SHORTWAVE TROUGH. AT THE SURFACE...THE TROUGH AXIS
ESSENTIALLY BISECTING THE AREA AT SUNRISE WILL CONTINUE PUSHING
SOUTHEAST THROUGH THE DAY. IN ITS WAKE...FAIRLY LIGHT BREEZES OF
ONLY AROUND 10 MPH FROM THE NORTH-NORTHWEST WILL PREVAIL. THESE
LIGHT WINDS WILL MAKE FOR PLEASANT CONDITIONS THANKS TO THE NEXT
IN A LONG STRETCH OF SEASONABLY WARM DAYS. MADE VERY LITTLE
CHANGE TO HIGH TEMPS...AND IF ANYTHING NUDGED SOME PLACES UP
ANOTHER DEGREE...AIMING FOR LOW 60S NORTHEAST...MID 60S CENTRAL
INCLUDING TRI-CITIES...AND UPPER 60S KS ZONES. THE OVERALL BIGGEST
CHANGE TO THE MONDAY GRIDS WAS TO DEWPOINTS...WHICH WERE LOWERED
4-7 DEGREES...WITH VALUES ONLY EXPECTED TO AVERAGE IN THE LOW-MID
30S IN MOST AREAS. EVEN SO...RELATIVE HUMIDITY VALUES SHOULD STILL
DROP NO LOWER THAN THE UPPER 20S...KEEPING FIRE DANGER QUITE LOW
THANKS TO THE LIGHT WINDS.
LONG TERM...STARTING 00Z TUESDAY. GUIDANCE FROM THE
OPERATIONAL GFS...GEFS-MEAN AND EC ALL CONTINUE TO SUGGEST MID
AND UPPER LEVEL JET ENERGY WILL REMAIN TO THE NORTH OF THE CENTRAL
PLAINS THROUGH THE LONG TERM FORECAST PERIOD. A MID LEVEL SHORT
WAVE IS EXPECTED TO PUSH ACROSS SOUTHERN CANADA AND THE NORTHERN
PLAINS DURING THE DAY THURSDAY...ALONG WITH A WEAK MID LEVEL
PERTURBATION WHICH IS EXPECTED PUSH ACROSS THE SOUTHERN PLAINS
ALSO ON THURSDAY. ALTHOUGH THESE MID LEVEL DISTURBANCES WILL
REMAIN NORTH AND SOUTH OF OUR REGION...AN ASSOCIATED LOW LEVEL
BAROCLINIC ZONE IS EXPECTED TO PUSH ACROSS OUR AREA DURING THE DAY
THURSDAY. THE OPERATIONAL GFS AND EC BOTH CONTINUE TO SUGGEST LOW
LEVEL CONVERGENCE AND RESULTANT FORCING WILL REMAIN WEAK ALONG
THIS BAROCLINIC ZONE. ALTHOUGH THERE COULD BE AN INCREASE IN MID
TO HIGH LEVEL CLOUDS AS THE MID LEVEL PERTURBATION PUSHES ACROSS
THE SOUTHERN PLAINS...AN OVERALL LACK IN KINEMATIC FORCING SHOULD
KEEP OUR AREA DRY THROUGHOUT THE LONG TERM FORECAST PERIOD.
LITTLE CHANGE IN THE LOW LEVEL AIRMASS TUESDAY THROUGH THURSDAY WILL
PRESENT SIMILAR TEMPERATURES EACH DAY...WITH HIGHS GENERALLY IN THE
60S AND LOWS IN THE 30S AND 40S...WHICH IS WELL ABOVE NORMAL FOR
THIS TIME OF YEAR. WEAK LOW LEVEL COLD AIR ADVECTION POST FROPA
BEGINNING THURSDAY NIGHT WILL THEN PRESENT SOMEWHAT COOLER WEATHER
TO FINISH OUT THE WEEK...WITH HIGHS GENERALLY IN THE 50S AND LOWS IN
THE 30S...STILL ABOVE NORMAL FOR THIS TIME OF YEAR.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...PFANNKUCH
LONG TERM...BRYANT
AVIATION...ROSSI
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1227 AM EST SAT NOV 17 2012
.SYNOPSIS...
A RIDGE OF HIGH PRESSURE WILL REMAIN ACROSS THE REGION THROUGH THE
WEEKEND. LOW PRESSURE WILL SLOWLY MAKE ITS WAY NORTH ALONG AND
EAST COAST OF THE UNITED STATES THROUGH THE MIDDLE OF NEXT WEEK.
AN UPPER LEVEL DISTURBANCE WILL MOVE THROUGH THE OHIO VALLEY INTO
OUR REGION ON TUESDAY.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 845 PM EST FRIDAY...
A DRY UPPER LEVEL SHORTWAVE TROF SEEN ON WATER VAPOR SATELLITE
IMAGERY JUST TO WEST THIS EVENING WILL WEAKEN TONIGHT AS A RIDGE
OF HIGH PRESSURE AT THE SURFACE BUILDS INTO OUR AREA.
THIS SHOULD ALLOW FOR GOOD RADIATIONAL COOLING CONDITIONS IN THE
VALLEYS TONIGHT. A FEW HIGH CLOUDS ACROSS NW NC INTO FAR SOUTHWEST
VA SHOULD ERODE PER FORECAST SOUNDINGS AND RAP UPPER LEVEL RH
FORECAST. TRIED TO ILLUSTRATE A LARGER DIFFERENCE IN LOWS FROM
RIDGES TO VALLEYS WITH FCX VWP SHOWING NORTHEAST WINDS HAVE
INCREASED TO 25KTS. AS A RESULT...PUSHED UP LOW AT ROA AND
BLF...BUT CONTINUE TO GO BELOW GUIDANCE FOR LOWS IN VALLEY
LOCATIONS.
ON SATURDAY...HIGH PRESSURE AND PLENTY OF SUNSHINE WILL PREVAIL.
HIGH TEMPERATURES ARE EXPECTED TO BE COMPARABLE OR SLIGHTLY MILDER
THAN THOSE REALIZED TODAY.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY/...
AS OF 305 PM FRIDAY...
RATHER DRY AIRMASS WILL REMAIN IN PLACE EARLY SAT EVENING BUT THE
LOW LVL FLOW WILL INCREASE OFF THE ATLANTIC AS UPPER LOW SHIFTS EAST
OVER THE SOUTHEAST U.S. THIS IS THE MAIN ISSUE FOR THE FORECAST TO
FINISH OUT THE WEEKEND AND GOING INTO EARLY NEXT WEEK. MODELS ARE
SIMILAR IN THE WEDGE REMAINING IN PLACE BUT DIFFER IN TERMS OF HOW
FAR WEST THE LOWER CLOUDS MOVE IN. THINK THE NAM IS ON THE RIGHT
TRACK WITH INCREASING ATLANTIC MOISTURE MOVING INTO THE PIEDMONT
AREA BY DAWN SUNDAY...WITH THE CMC/GFS FOLLOWING SUIT ON SUNDAY. THE
WWD EXTEND THRU SUNDAY WILL BE UP TO THE BLUE RIDGE AND HOW MUCH DRY
AIR IS DISPLACED WILL BE THE DIFFERENCE BETWEEN LESS CLOUDS AND
COLDER LOWS TO THE WEST AND BKN SKIES AND SOMEWHAT WARMER TEMPS IN
THE EAST. THIS HAS THE POTENTIAL TO BUST ONE WAY OR THE OTHER IF THE
CLOUDS DO NOT ADVECT IN/DEVELOP AS FORECAST...MEANING COLDER LOWS.
CONFIDENCE IS LOW ON THE OTHER SCENARIO OF SEEING OVC SKIES ALL THE
WAY TO THE WV BORDER PER NAM.
SUNDAY SHOULD BE MAINLY DRY WITH CLOUDS TRYING TO ERODE FROM THE
SOUTHWEST OUTSIDE THE HIGH PRESSURE WEDGE...BUT THINK THE EASTERN
FORECAST AREA SHOULD STAY MOSTLY CLOUD ALL DAY. COULD EVEN SQUEEZE
OUT SOME LIGHT RAIN EAST OF DANVILLE. HIGHS WILL BE AFFECTED AGAIN
WITH THE WEDGE. WENT BELOW MOS GUIDANCE OUT EAST WHERE HIGHS MAY
STRUGGLE TO REACH 50...WHILE THE SW MTNS OVER BLF-RICHLANDS SEE
TEMPS RISE TOWARD 60. SHARP GRADIENT IN CLOUDS VS SUN IS EXPECTED.
HEADING INTO SUNDAY NIGHT INTO MONDAY WILL CONTINUE TO SEE THE UPPER
LOW SHIFT OFF THE SOUTHEAST COAST WITH SFC LOW FORMING WELL EAST OF
THE COASTLINE. STILL MOISTURE WILL STREAM WEST ON THE NORTH SIDE OF
THE SYSTEM AND WILL SEE POTENTIAL FOR LIGHT RAIN AND/OR DRIZZLE
SOUTHEAST OF THE BLUE RIDGE. KEPT POPS ONLY IN THE SLIGHT CHANCE
RANGE MONDAY EAST OF A LYH/DAN LINE AND ACROSS THE SRN BLUE RIDGE
PER SOME UPSLOPE. ADDED DRIZZLE AS WELL FURTHER NORTH OVER THE NEW
RIVER VALLEY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 314 EST FRIDAY...
PERSISTENT LLVL NORTHERLY FLOW AND MOISTURE WILL LEAD TO CLOUDS AND
LIGHT SHOWERS AT TIMES EARLY NEXT WEEK. AFTER AN UPPER LEVEL TROUGH
PASSES THROUGH MIDWEEK...WINDS WILL SHIFT TO A DOWNSLOPING
DIRECTION...SUCH THAT CLEARING AND WARMING WILL ENSUE. WITH H85
TEMPS AROUND +8C BY THE END OF THE WEEK WITH A VERY DRY
PROFILE...THANKSGIVING DAY LOOKS WARM AND CLEAR...WITH SOME OF THE
CITIES MAKING A RUN TOWARDS 70F THURSDAY AND FRIDAY. THERE SHOULD BE
ZERO TRAVEL CONCERNS FOR THIS PART OF THE COUNTRY.
&&
.AVIATION /05Z SATURDAY THROUGH WEDNESDAY/...
AS OF 1220 AM EST SATURDAY...
VFR CONDITIONS AND LIGHT SURFACE WINDS ARE EXPECTED THIS EVENING AS
HIGH PRESSURE REMAINS ACROSS THE REGION.
AREAS OF MVFR AND IFR CIGS AND VSBYS POSSIBLE LATE TONIGHT INTO
MONDAY WITH A STRONG INVERSION SURFACE WEDGE ACROSS THE
REGION...ESPECIALLY ALONG AND EAST OF THE CREST OF THE BLUE RIDGE.
EXPECT ANY LOWER CEILINGS WILL NOT DEVELOP UNTIL AFTER THE 06Z END
OF THE TAF FORECAST PERIOD.
AN UPPER DISTURBANCE ON TUESDAY WILL WEAKEN THE WEDGE...BUT WILL ALSO
INTRODUCE THE POTENTIAL FOR ISOLATED SHOWERS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...DS
NEAR TERM...PH
SHORT TERM...WP
LONG TERM...KM
AVIATION...AMS/DS/KM
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1001 AM PST Sat Nov 17 2012
.SYNOPSIS...
Today through next week expect a progressive and wet weather
pattern to return with periods of mountain snow and valley rain
this weekend and through next week. Higher snow levels Sunday
Night through Tuesday morning will combine with the heaviest
expected precipitation in this forecast cycle to produce rises on
the areas small stream or creeks...especially for North Idaho.
&&
.DISCUSSION...Based on radar and latest HRRR (Rapid Refresh)model
runs showing substantial precipitation activity drifting northeast
through the forecast area have increased pops with update. HRRR
does hint at a lull in KGEG vicinity as that area is between area
of rain exiting to the northeast and has a few hours before a
second larger and more intense area of rain approaching in similar
fashion from the southwest is overhead near 00Z but I`m not sure I
can get grid forecast timing to depict this well so will just
leave the rather high pops in place for the remainder of today.
/Pelatti
&&
.AVIATION...
18Z TAFs: Moist airmass remains overhead as flow from the south
along and ahead of approaching low pressure system continues to
influence Eastern Washington and Northern Idaho aviation area. As
such will continue to keep mostly MVFR ceilings and visibilities
with a snow level generally above 4000 FT MSL which means it is
above all TAF sites so rain is what is expected with the most
significant quantity falling near and after 00Z /Pelatti
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 48 37 45 38 42 40 / 70 100 50 100 100 100
Coeur d`Alene 48 37 45 36 42 40 / 70 100 50 90 100 100
Pullman 52 37 47 38 44 42 / 50 100 30 80 100 100
Lewiston 53 40 53 42 50 45 / 30 100 30 60 80 90
Colville 45 37 43 38 41 38 / 80 100 50 100 100 100
Sandpoint 47 37 44 35 41 38 / 70 100 100 90 100 100
Kellogg 48 37 41 34 39 39 / 60 100 100 60 100 100
Moses Lake 46 36 47 39 47 40 / 60 80 10 60 80 70
Wenatchee 42 37 45 38 44 39 / 60 60 20 90 80 70
Omak 42 35 42 37 42 39 / 90 100 30 100 100 70
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS SPOKANE WA
9581 AM PST Sat Nov 17 2012
.SYNOPSIS...
Today through next week expect a progressive and wet weather
pattern to return with periods of mountain snow and valley rain
this weekend and through next week. Higher snow levels Sunday
Night through Tuesday morning will combine with the heaviest
expected precipitation in this forecast cycle to produce rises on
the areas small stream or creeks...especially for North Idaho.
&&
.DISCUSSION...Based on radar and latest HRRR (Rapid Refresh)model
runs showing substantial precipitation activity drifting northeast
through the forecast area have increased pops with update. HRRR
does hint at a lull in KGEG vicinity as that area is between area
of rain exiting to the northeast and has a few hours before a
second larger and more intense area of rain approaching in similar
fashion from the southwest is overhead near 00Z but I`m not sure I
can get grid forecast timing to depict this well so will just
leave the rather high pops in place for the remainder of today. /Pelatti
&&
.AVIATION...
18Z TAFs: Moist airmass remains overhead as flow from the south
along and ahead of approaching low pressure system continues to
influence Eastern Washington and Northern Idaho aviation area. As
such will continue to keep mostly MVFR ceilings and visibilities
with a snow level generally above 4000 FT MSL which means it is
above all TAF sites so rain is what is expected with the most
significant quantity falling near and after 00Z /Pelatti
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 48 37 45 38 42 40 / 70 100 50 100 100 100
Coeur d`Alene 48 37 45 36 42 40 / 70 100 50 90 100 100
Pullman 52 37 47 38 44 42 / 50 100 40 80 100 100
Lewiston 53 40 53 42 50 45 / 30 100 40 60 80 90
Colville 45 37 43 38 41 38 / 80 100 50 100 100 100
Sandpoint 47 37 44 35 41 38 / 70 100 80 90 100 100
Kellogg 48 37 41 34 39 39 / 60 100 80 60 100 100
Moses Lake 46 36 47 39 47 40 / 60 80 10 60 80 70
Wenatchee 42 37 45 38 44 39 / 60 60 20 90 80 70
Omak 42 35 42 37 42 39 / 90 100 30 100 100 70
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS SPOKANE WA
741 AM PST Sat Nov 17 2012
.SYNOPSIS...
Today through next week expect a progressive and wet weather
pattern to return with periods of mountain snow and valley rain
this weekend and through next week. Higher snow levels Sunday
Night through Tuesday morning will combine with the heaviest
expected precipitation in this forecast cycle to produce rises on
the areas small stream or creeks...especially for North Idaho.
&&
.DISCUSSION...Based on radar and latest HRRR (Rapid Refresh)model
runs showing substantial precipitation activity drifting northeast
through the forecast area have increased pops with update. HRRR
does hint at a lull in KGEG vicinity as that area is between area
of rain exiting to the northeast and has a few hours before a
second larger and more intense area of rain approaching in similar
fashion from the southwest is overhead near 00Z but I`m not sure I
can get grid forecast timing to depict this well so will just
leave the rather high pops in place for the remainder of today. /Pelatti
&&
.AVIATION...
06Z TAFs: The air mass over the region will become increasingly
moist at all levels this morning...with light rain beginning by
18z at KEAT and KMWH...spreading eastward to encompass the KGEG
area TAF sites buy 21Z. This will be mainly light isentropic rain
with ceilings predominantly VFR or occasional MVFR. Exception will
be KEAT where stubborn low level IFR stratus will be slow to erode
as precipitation begins. A strong cold front along the Cascade
Crest at 00Z will move to the Idaho Panhandle by 12Z Sunday.
Along this front dense shower coverage with MVFR ceilings and vis
are expected at all TAF sites immediately ahead of and along the
front. /MJF
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 48 37 45 38 42 40 / 70 100 50 100 100 100
Coeur d`Alene 48 37 45 36 42 40 / 70 100 50 90 100 100
Pullman 52 37 47 38 44 42 / 50 100 40 80 100 100
Lewiston 53 40 53 42 50 45 / 30 100 40 60 80 90
Colville 45 37 43 38 41 38 / 80 100 50 100 100 100
Sandpoint 47 37 44 35 41 38 / 70 100 80 90 100 100
Kellogg 48 37 41 34 39 39 / 60 100 80 60 100 100
Moses Lake 46 36 47 39 47 40 / 60 80 10 60 80 70
Wenatchee 42 37 45 38 44 39 / 60 60 20 90 80 70
Omak 42 35 42 37 42 39 / 90 100 30 100 100 70
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1122 AM CST SAT NOV 17 2012
.SHORT TERM...THROUGH MONDAY NIGHT
200 AM CST SAT NOV 17 2012
MAIN FORECAST CONCERNS ARE ON RAIN CHANCES SUNDAY NIGHT INTO MONDAY
NIGHT AS WELL AS TEMPERATURES THROUGHOUT.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED TROUGHING OFF BRITISH COLUMBIA...SUBTROPICAL RIDGING FROM
NORTHERN MEXICO TO LAKE ERIE...AND SHORTWAVES RIDING IN THE
SOUTHWEST SUBTROPICAL FLOW JUST OFF THE CALIFORNIA COAST AND NEAR
THE WY/SOUTH DAKOTA BORDER. THIS LATTER SHORTWAVE WAS PRODUCING A
MASS OF CIRRUS ACROSS THE DAKOTAS INTO NORTHWEST MINNESOTA. DRY LOW
TO MID LEVELS SEEN ON THE 00Z MPX...ABR AND UNR SOUNDINGS HAS
PREVENTED ANY LOWER CLOUD DEVELOPMENT. REGARDING THE DRYNESS...BOTH
MPX AND ABR SOUNDINGS ONLY HAD PRECIPITABLE WATER VALUES OF 0.20
INCHES. FARTHER TO THE EAST...AN AREA OF LOW STRATUS WAS PRESENT
ACROSS MUCH OF GRBS FORECAST AREA INTO LOCATIONS ALONG/NORTHEAST OF
I-94 IN OUR AREA. THIS STRATUS FORMED FROM SOUTHEAST ADVECTION OF
MOISTURE OFF LAKE MICHIGAN UNDERNEATH A SUBSIDENCE INVERSION...
COMBINED WITH LIGHT WINDS AND CLEAR SKIES EARLIER IN THE EVENING. A
STRONGER SOUTH FLOW ON THE BACK SIDE OF HIGH PRESSURE OVER LOWER
MICHIGAN HAS HELPED KEEP THE REST OF THE AREA LOW CLOUD FREE. THIS
FLOW...WHICH STRENGTHENS HEADING WEST TOWARDS THE DAKOTAS...HAS BEEN
BRINGING WARMER AIR INTO THE REGION. RAP ANALYSIS SHOWED 925MB TEMPS
OF 7C AT MPX COMPARED TO 2C ON THE 00Z SOUNDING. SURFACE
TEMPERATURES HAVE REFLECTED THE WARM ADVECTION WITH READINGS FROM
THE MID 20S TO MID 30S...WARMEST WEST OF THE MISSISSIPPI RIVER.
TODAY AND TONIGHT...THE SHORTWAVE ALONG THE WYOMING/SOUTH DAKOTA
BORDER IS PROGGED TO LIFT INTO NORTHERN MINNESOTA TONIGHT. THE TRACK
IS SLIGHTLY FARTHER NORTH THAN 24 HOURS AGO. WITH THE FARTHER NORTH
TRACK...THERE SHOULD BE A LITTLE LESS CLOUDS. SOME OF THE CIRRUS
STILL LOOKS SLATED TO CROSS THE FORECAST AREA LATE THIS AFTERNOON
INTO THIS EVENING...WITH SOME ALTOSTRATUS PRODUCED BY ISENTROPIC
LIFT AFTER MIDNIGHT. PLENTY OF LOW LEVEL DRY AIR WILL RESULT IN A
CONTINUATION OF THE DRY FORECAST. ONLY OTHER CLOUD COVER OF NOTE IS
THE EARLY MORNING STRATUS OVER THE NORTHEAST PORTION OF THE FORECAST
AREA...WHICH SHOULD SHIFT NORTHEAST DURING THE MORNING WITH THE
INCREASING SOUTH TO SOUTHWEST 950-925MB FLOW. THIS FLOW IS PROGGED
TO REACH 25-30KT TODAY AS THE GRADIENT TIGHTENS. WITH PLENTY OF
SUN...EXPECT BREEZY CONDITIONS...PARTICULARLY ON THE HIGHER TERRAIN
WEST OF THE MISSISSIPPI RIVER WHICH IS MORE EXPOSED AND IN THE
TIGHTEST GRADIENT. THE BREEZE SHOULD PERSIST INTO TONIGHT WITH THE
STRENGTHENING OF THE LOW LEVEL JET...NOTED TOO BY 950-925MB WINDS
INCREASING TO 30-45KT. THESE WINDS WILL CONTINUE TO BRING WARMER AIR
INTO THE REGION WITH 925MB TEMPS INDICATED BETWEEN 4-6C AT 18Z.
THESE SUPPORT HIGHS IN THE LOW TO MID 50S. FOLLOWED A BLEND OF
GUIDANCE FOR LOWS TONIGHT WITH THE BREEZE AND PASSING CLOUDS HELPING
TO PRODUCE A WARMER NIGHT.
SUNDAY INTO SUNDAY NIGHT...ATTENTION FOCUSES TO THE SHORTWAVE OFF
THE CALIFORNIA COAST. GOOD MODEL AGREEMENT EXISTS THAT THIS
SHORTWAVE WILL LIFT INTO THE CENTRAL PLAINS BY LATE SUNDAY...THEN
INTO WESTERN PORTIONS OF MINNESOTA AND IOWA BY 12Z MONDAY. RIDGING
LOOKS TO DEVELOP OVER THE FORECAST AREA FOR A TIME AHEAD OF THIS
SHORTWAVE AND IN THE WAKE OF THE SHORTWAVE LIFTING OUT OF NORTHERN
MINNESOTA. SUBSIDENCE UNDER THE RIDGE SHOULD THIN CLOUDS OUT SOME
FOR MUCH OF THE DAY UNTIL LATE. THIS IS WHEN THE AREA BEGINS TO FEEL
THE MOISTURE ADVECTION EFFECTS AHEAD OF THE SHORTWAVE...WHICH WILL
START PRODUCING AN ALTOSTRATUS DECK IN THE EVENING ACROSS THE AREA.
FURTHER LOWERING OF CEILINGS WILL OCCUR THROUGH THE NIGHT AS
PRECIPITABLE WATER VALUES CLIMB FROM AROUND 0.5 INCH AT 00Z TO NEAR
0.75 INCHES AT 12Z MONDAY. ALTHOUGH MOISTURE INCREASES...THE
ISENTROPIC LIFT IS QUITE WEAK...FOCUSED MAINLY WEST OF A LINE FROM
MEDFORD TO LA CROSSE AND OELWEIN BETWEEN 06-12Z. HAVE MAINTAINED A
20-30 PERCENT CHANCE FOR THIS AREA AND TIME PERIOD...BUT GIVEN THE
WEAK LIFT SIGNATURE IT IS POSSIBLE ANY PRECIPITATION HOLDS OFF UNTIL
AFTER 12Z MONDAY AS SUGGESTED BY THE 17.00Z GFS/NAM. 17.00Z ECMWF IS
MORE ROBUST...THOUGH. WARMER 925MB TEMPS IN THE 5-7C RANGE AT 18Z
SUNDAY PLUS THE SOUTHERLY BREEZE AND SUN SHOULD YIELD HIGHS IN THE
MID TO UPPER 50S. A FEW LOCATIONS MAY REACH OR EXCEED 60...
ESPECIALLY IF MORE SUN OCCURS. EVEN A WARMER NIGHT SHOULD OCCUR
SUNDAY NIGHT WITH MORE MOISTURE...CLOUDS AND THE BREEZE. LOWS WEST
OF THE MISSISSIPPI RIVER MAY NOT DIP BELOW 40.
MONDAY AND MONDAY NIGHT...THE SHORTWAVE TROUGH OVER THE PLAINS
MODELS AGREE ON BRINGING IT ACROSS THE FORECAST AREA MONDAY EVENING.
AS THE TROUGH APPROACHES MONDAY...THE ISENTROPIC LIFT LOOKS TO
INCREASE A LITTLE...ENOUGH TO WARRANT PRECIPITATION CHANCES AS HIGH
AS 40 PERCENT. KEPT THESE CHANCES LOW BECAUSE BOTH THE 17.00Z GFS
AND NAM SHOW A DRY LOOK TO THEIR QPF FIELDS. THE ECMWF REMAINS THE
MOST ROBUST...THOUGH ITS LATEST 17.00Z RUN HAS A SLIGHTLY DRIER LOOK
THAN ITS PREVIOUS 16.12Z RUN. MUCH OF THE RAIN...IF IT OCCURS...
SHOULD BE EAST OF THE AREA BY 00Z. HOWEVER...HAVE MAINTAINED A 20
PERCENT CHANCE OVER FAR EASTERN AREAS FROM 00-06Z SINCE THERE IS
STILL WEAK ISENTROPIC LIFT INDICATED ON THE 290-295K SURFACES.
PLENTY OF CLOUDS ON MONDAY WILL PREVENT TEMPERATURES FROM RISING AS
MUCH COMPARED TO THE WEEKEND. HAVE FOLLOWED A BLEND OF GUIDANCE FOR
HIGHS. CLOUDS GRADUALLY CLEARING OUT WEST TO EAST MONDAY NIGHT PLUS
LIGHTER WINDS RESULTING FROM A WEAKER PRESSURE GRADIENT SHOULD ALLOW
TEMPERATURES TO DIP INTO THE 30S TO AROUND 40 AT MOST LOCATIONS.
.LONG TERM...TUESDAY THROUGH FRIDAY NIGHT
200 AM CST SAT NOV 17 2012
THE MAIN ISSUE IN THE LONG TERM FORECAST IS A VERY POTENT SHORTWAVE
COMING OUT OF THE NORTHEAST PACIFIC TROUGH AND ENTERING THE PACIFIC
NORTHWEST TUESDAY EVENING. ALL MODELS AGREE ON UPPER RIDGING
BUILDING AHEAD OF THE POTENT SHORTWAVE INTO THE FORECAST AREA
TUESDAY NIGHT...RESULTING IN A SURGE OF WARM AIR ADVECTING INTO THE
AREA. 925MB TEMPS CLIMB FROM AROUND 6C AT 18Z TUESDAY TO 10-12C AT
18Z WEDNESDAY. 850MB TEMP ANOMALIES ON WEDNESDAY ARE 1.5 STANDARD
DEVIATIONS ABOVE NORMAL. PLENTY OF SUN LOOKS TO OCCUR AT LEAST ON
WEDNESDAY...AND PERHAPS TUESDAY TOO DEPENDING ON WHEN LOW CLOUDS
CLEAR ASSOCIATED WITH THE MONDAY/MONDAY NIGHT SHORTWAVE.
THEREFORE...THERE SHOULD BE DECENT MIXING DESPITE THE SHORTER DAY
LENGTH. HAVE LEANED ON THE WARM SIDE OF GUIDANCE AS A RESULT...
ESPECIALLY WEDNESDAY WHEN HIGHER CONFIDENCE EXISTS OF FULL SUN AND A
SOUTHERLY BREEZE IS PRESENT. HIGHS WEDNESDAY COULD REACH OR EXCEED
60...ABOUT 20 DEGREES ABOVE NORMAL. DRY AIR IN PLACE WILL PREVENT
ANY PRECIPITATION WITH THE WARM ADVECTION...AND PERHAPS CLOUDS TOO.
AS WE HEAD INTO THANKSGIVING AND THROUGH FRIDAY NIGHT...THE 17.00Z
CANADIAN/ECMWF/GFS AND GFS ENSEMBLES ALL POINT TO THE POTENT
SHORTWAVE DIGGING SOUTHEAST THROUGH THE UPPER MISSISSIPPI RIVER
VALLEY REGION. THIS IS DIFFERENT FROM THE 16.12Z ECMWF AND 16.00Z
GFS WHICH HAD MORE OF A FLATTER...ZONAL FLOW. THUS...WE WILL SEE IF
THIS IDEA OF THE SHORTWAVE DIGGING INTO THE AREA CONTINUES WITH
LATER RUNS. NOTE THAT THE 17.00Z GFS ENSEMBLES ARE ALL OVER THE
PLACE WITH THIS FEATURE. IN ANY EVENT...RIGHT NOW THERE IS GOOD
AGREEMENT ON IT OCCURRING FROM THE DETERMINISTIC MODELS...BUT TIMING
VARIES FROM THANKSGIVING DAY TO FRIDAY. FOR NOW HAVE STUCK WITH A
CONSENSUS APPROACH WHICH BRINGS THE POTENT TROUGH IN THANKSGIVING
DAY NIGHT. THUS...THANKSGIVING STILL LOOKS WARM AHEAD OF A COLD
FRONT MOVING IN. HIGHS MOST LOCATIONS SHOULD END UP IN THE 50S.
COOLER CONDITIONS ARE LIKELY ON FRIDAY IN THE WAKE OF THE COLD FRONT
AS 850MB TEMPS PLUMMET DOWN TO AT OR BELOW 0C BY 00Z SATURDAY.
REGARDING THE COLD FRONTAL PASSAGE FOR PRECIPITATION...RIGHT NOW IT
APPEARS STILL THAT THE AIRMASS IS TOO DRY BOTH BEHIND AND AHEAD OF
THE FRONT TO ALLOW FOR ANYTHING TO OCCUR. ANY PRECIPITATION SHOULD
STAY TO THE NORTH...CLOSER TO THE BETTER DYNAMICS...AND TO THE
SOUTHEAST WHERE A LONGER PERIOD OF MOISTURE RETURN CAN OCCUR.
&&
.AVIATION...THROUGH 18Z SUNDAY
1122 AM CST SAT NOV 17 2012
MAIN CONCERN THROUGH THE NEXT 24 HOURS WILL BE THE WINDS. THIS IS
A RESULT OF INCREASING PRESSURE GRADIENT BEHIND DEPARTING HIGH
PRESSURE OVER THE GREAT LAKES AND A TROUGH OF LOW PRESSURE MOVING
INTO THE NORTHERN PLAINS. SOUTH WINDS WILL BE IN THE 15 TO 25KT
RANGE THIS AFTERNOON ACROSS THE HIGHER-OPEN TERRAIN OF SOUTHEAST
MINNESOTA AND IN THE 10-20KT RANGE ELSEWHERE. LOOK FOR THE
GUSTINESS TO SUBSIDE TONIGHT AS THE ATMOSPHERE DECOUPLES WITH
SUNSET. HOWEVER...WINDS AROUND 1KFT AGL ARE EXPECTED TO REMAIN
AROUND 30-35KT WHICH COULD MAKE FINAL APPROACH/TAKE OFFS A BIT
BUMPY. WAS CONTEMPLATING INCLUDING SOME LLWS OVERNIGHT...BUT WILL
BE JUST A BIT SHY OF CRITERIA. AN INCREASE IN ALTOCUMULUS WILL
ALSO BE NOTED THIS EVENING/OVERNIGHT...THEN SCATTERING OUT BY LATE
SUNDAY MORNING. OTHERWISE...LOOK FOR SURFACE WINDS TO BECOME GUSTY
AGAIN AFTER SUNRISE. PLAN ON SOUTH WINDS AT 15-25KT ONCE AGAIN
ACROSS THE HIGHER TERRAIN OF SOUTHEAST MN...AND IN THE 10-20KT
RANGE ELSEWHERE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
200 AM CST SAT NOV 17 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...DAS
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1013 AM CST SAT NOV 17 2012
.UPDATE...QUIET WEATHER AND MILD TEMPS IN STORE FOR THE CWA...AS
HIGH PRESSURE IN THE EASTERN GREAT LAKES AND NE U.S. CONTINUES TO
INFLUENCE SOUTHERN WI. MINOR CHANGES MADE IN THIS UPDATE WITH THE
MAIN CONCERNS BEING HIGH TEMPS AND SKY COVER. THE LATTER IS MORE SO
IN REGARD TO LOW VIS AND LOW CLOUD DISSIPATION/IMPROVEMENT IN THE
NORTHWEST QUAD OF THE CWA THIS MORNING...WHERE VIS AND SKIES
CONTINUES TO IMPROVE FROM WHERE THE DENSE FOG ADVISORY WAS ALLOWED
TO EXPIRE AT 9 AM.
VIS SAT SHOWS CIRRUS OVER MUCH OF THE CWA...WITH FOG AND LOW CLOUDS
STILL EVIDENT IN PORTIONS NW. AT 9 AM...VIS WAS 3/4 SM AT
WAUTOMA...1 1/2 SM AT CAMP DOUGLAS...AND 5 SM AT THE WISCONSIN DELLS
AND FOND DU LAC. VIS SAT TRENDS CONTINUE TO SHOW FOG/LOW CLOUDS
MOVING NORTH/DISSIPATING AS EXPECTED...SHOULD BE OUT OF THE CWA
BETWEEN 10 AND 11 AM. ELSE...MOSTLY SUNNY SKIES CAN BE EXPECTED
TODAY AS BUFKIT SOUNDINGS SHOW DRY COLUMNS WITH ANY RESIDUAL
LOW-LEVEL MOISTURE FROM THIS MORNING DRYING OUT. 925 HPA TEMPS ARE
GENERALLY IN GOOD AGREEMENT WITH A RANGE FROM 7-5 C FROM SOUTHWEST TO
NORTHEAST. IF 925 TEMPS WERE MIXED DOWN DRY ADIABATICALLY...THIS
WOULD YIELD HIGHS AROUND 56-52 F. CURRENT FCST HIGHS ARE 53 FAR SW
TO 50 NE. HOWEVER...CONCERNS EXIST RELATED TO A COOL ON-SHORE FLOW
IN THE EAST AT THE SURFACE AND WHETHER MIXING WILL BE ADEQUATE.
BUFKIT RAP AND NAM SOUNDINGS SHOW THAT LOCATIONS IN THE CWA DO NOT
QUITE MIX OUT THAT HIGH...WITH JUST THE NAMS MSN AND MKX SOUNDINGS
SHOWING MIXING UP TO/NEAR 925 HPA. AS SUCH...DID NOT CHANGE TODAYS
HIGHS...BUT WILL MONITOR TO SEE HOW THE TEMPERATURE TREND FARES THE
REST OF THE MORNING BEFORE RULING OUT ANY CHANGES.
&&
.AVIATION/18Z TAFS/...CONDITIONS HAVE RETURNED TO VFR ACROSS MOST
OF SOUTHERN WISCONSIN THIS MORNING...WITH VFR CONDITIONS EXPECTED
TO PREVAIL THROUGH SUNDAY. WILL BE DRIER TONIGHT...WITH MORE MID
AND HIGH LEVEL CLOUDS AND HIGHER LOW LEVEL WINDS...SO NOT
EXPECTING A REPEAT OF THE FOG FROM LAST NIGHT.
&&
.PREV DISCUSSION... /ISSUED 332 AM CST SAT NOV 17 2012/
TODAY AND TONIGHT...FORECAST CONFIDENCE IS MEDIUM TO HIGH.
TODAY...EXPANDED DENSE FOG ADVISORY TO COVER THE REMAINDER OF
SOUTHEAST WISCONSIN AND NORTHERN SOUTH CENTRAL WISCONSIN AS
STRATUS IS SPREADING NORTHEAST. ALSO EXTENDED END TIME TO 9 AM CST
AS FORECAST SOUNDINGS SHOW LITTLE MIXING UNTIL THEN.
TIMING OF FOG AND LOW CLOUD DISSIPATION THIS MORNING WILL HAVE AN
IMPACT ON HIGH TEMPERATURES TODAY. MODELS IN GOOD AGREEMENT THAT
925 MB TEMPERATURES WILL BE IN THE +5C TO +6C RANGE...WITH +7C IN
THE FAR WEST...BY MID TO LATE AFTERNOON. NAM/GFS MODEL SOUNDINGS
MIXING DRY ADIABATICALLY TO THESE TEMPS ARE YIELDING LOW TO MID
50S HIGHS.
HOWEVER...WITH WARM AIR ADVECTION ON SOUTHWEST WINDS INCREASING TO
20-25 KNOT WINDS AT/ABOVE 1K FT OVER WEAKER SOUTHEAST WINDS THAT
WILL BE KEEPING THE NEAR SURFACE AIR COOLER...THE RAP SOUNDINGS
NEVER FULLY MIX OUT THE BOUNDARY LAYER INVERSION TO REACH 925 MB.
WENT WITH A BLENDED SOLUTION THAT LEANS TOWARD THE WARM SIDE IN
THE CURRENT FOG-FREE AREAS IN THE WEST...AND IS COOLER EAST WHERE
THE COMBINATION OF EARLY FOG...AND SOUTHEAST WINDS OFF THE MID-
UPPER 40 DEGREE LAKE WATER WILL LIMIT HIGHS.
TONIGHT...GRADIENT SHOULD BE SUFFICIENT FOR SOUTHERLY WINDS TO
KEEP THE BOUNDARY LAYER MIXED AND PREVENT FOG TONIGHT. EXPECT ONLY
SOME MID-HIGH LEVEL CLOUDS WITH A WEAK SHORT WAVE CROSSING REGION
OVERNIGHT.
SUNDAY THROUGH MONDAY NIGHT...FORECAST CONFIDENCE IS HIGH.
SOUTHWEST 500MB FLOW IS DEPICTED BY THE SHORT TERM MODELS ACROSS
THE REGION SUNDAY INTO MONDAY. SHORTWAVE TROUGH MOVES THROUGH THE
AREA FROM THE SOUTHWEST LATE SUNDAY NIGHT AND MONDAY...WITH A
TRAILING SHORTWAVE THEN SHIFTING EAST SOUTHEAST INTO THE AREA
MONDAY NIGHT. AT THE SURFACE...MILD SOUTHERLY FLOW CONTINUES
ACROSS THE REGION SUNDAY INTO MONDAY...WITH A SURFACE TROUGH
MOVING EASTWARD INTO THE AREA MONDAY NIGHT.
AREA FORECAST SOUNDINGS FROM NAM/GFS SHOW SOME MID TO HIGH CLOUDS
SUNDAY INTO SUNDAY NIGHT...WITH MORE CLOUDS MONDAY/MONDAY NIGHT
WITH PASSAGE OF SHORTWAVES AND SURFACE TROUGH. SOUNDINGS DO
INDICATE AIR COLUMN BECOMING MOIST IN THE LOW LEVELS MONDAY
NIGHT...BUT THE MID TO UPPER LEVELS DRY OUT. LIGHT QPF IS SEEN
ACROSS PORTIONS OF THE AREA MONDAY AND MONDAY NIGHT.
CONTINUED TO MENTION LOW END POPS FOR MONDAY AND MONDAY NIGHT.
TEMPERATURES WILL REMAIN ABOVE NORMAL...WITH HIGHS WELL INTO THE
50S SUNDAY AND MONDAY PER NAM 925MB TEMPERATURES. LOWS WILL
MODERATE FROM THE 30S SUNDAY NIGHT TO THE LOWER TO MID 40S MONDAY
NIGHT.
TUESDAY THROUGH WEDNESDAY NIGHT...FORECAST CONFIDENCE IS HIGH.
GFS AND ECMWF SHOW GOOD AGREEMENT WITH FEATURES TUESDAY THROUGH
WEDNESDAY NIGHT. THEY SHOW THE SHORTWAVE TROUGH PUSHING THROUGH
AND EAST OF THE AREA TUESDAY. AREA GFS FORECAST SOUNDINGS SHOW
SOME LOW LEVEL MOISTURE LINGERING...BUT A DRY AIR COLUMN ABOVE IT.
KEPT LOW POPS TUESDAY MORNING IN THE FAR EAST/SOUTHEAST COUNTIES
IN THE MORNING...THEN DRY IN THE AFTERNOON.
BOTH MODELS THEN SHOW A 500MB RIDGE AXIS PASSING THROUGH THE AREA
TUESDAY NIGHT AND WEDNESDAY...WITH SOUTHWEST FLOW IN PLACE
WEDNESDAY NIGHT. SOUTH TO SOUTHWEST FLOW IN THE LOW LEVELS WITH
WARM AIR ADVECTION WILL OCCUR ACROSS THE REGION. AREA GFS FORECAST
SOUNDINGS REMAIN DRY DURING THIS TIME.
THUS...QUIET WEATHER IS EXPECTED TUESDAY NIGHT THROUGH WEDNESDAY
NIGHT...WITH ABOVE NORMAL TEMPERATURES CONTINUING. GIVEN THE
EXPECTED NAM 925MB TEMPERATURES...MAY REACH AS HIGH AS AROUND 60
ON WEDNESDAY.
THANKSGIVING DAY THROUGH FRIDAY...FORECAST CONFIDENCE IS MEDIUM.
GFS AND ECMWF THEN DIFFER SOMEWHAT WITH FEATURES THURSDAY THROUGH
FRIDAY. THE GFS AND ECMWF BRING DEVELOPING LOW PRESSURE EAST FROM
NORTHERN MINNESOTA TO LAKE SUPERIOR THURSDAY...THEN NORTHEAST AS
IT BECOMES STRONGER THURSDAY NIGHT AND FRIDAY.
THE GFS HAS A COLD FRONT WITH LIGHT QPF MOVING EAST THROUGH THE
AREA THANKSGIVING DAY...FOLLOWED BY A STRONG VORTICITY MAXIMUM
PASSING THROUGH THURSDAY NIGHT INTO FRIDAY. THEY BOTH DO SHOW
BRISK WEST/NORTHWEST WINDS BRINGING COLDER AIR INTO THE REGION
THURSDAY NIGHT INTO FRIDAY. THE ECMWF BRINGS A DRY COLD FRONTAL
PASSAGE THURSDAY NIGHT. IT ALSO BRINGS A SECONDARY VORTICITY
MAXIMUM THROUGH THE AREA FRIDAY.
FOR NOW...WILL USE BLENDED POPS AND TEMPERATURES FOR THANKSGIVING
DAY THROUGH FRIDAY. THIS WILL MEAN DRY CONDITIONS AND CONTINUED
MILD TEMPERATURES. HIGHS THANKSGIVING DAY SHOULD REACH WELL INTO
THE 50S BEFORE THE FRONT MOVES THROUGH.
AVIATION/12Z TAFS/...WILL KEEP IFR/LIFR CONDITIONS AT AREA TAF
SITES UNTIL AT LEAST 13Z...AND POSSIBLY 14-15Z IN THE EAST...UNTIL
DAYTIME MIXING INCREASES WINDS AND RAISES CIGS AND VISIBILITIES.
SHOULD SEE VFR CONDITIONS ACROSS THE FORECAST AREA BY MID TO LATE
MORNING...WITH QUIET WEATHER THEN EXPECTED THROUGH THE REST OF THE
FORECAST PERIOD WITH VFR CONDITIONS.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...ET
TODAY/TONIGHT AND AVIATION/MARINE...REM
SUNDAY THROUGH FRIDAY...WOOD
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
551 AM CST SAT NOV 17 2012
.SHORT TERM...THROUGH MONDAY NIGHT
200 AM CST SAT NOV 17 2012
MAIN FORECAST CONCERNS ARE ON RAIN CHANCES SUNDAY NIGHT INTO MONDAY
NIGHT AS WELL AS TEMPERATURES THROUGHOUT.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED TROUGHING OFF BRITISH COLUMBIA...SUBTROPICAL RIDGING FROM
NORTHERN MEXICO TO LAKE ERIE...AND SHORTWAVES RIDING IN THE
SOUTHWEST SUBTROPICAL FLOW JUST OFF THE CALIFORNIA COAST AND NEAR
THE WY/SOUTH DAKOTA BORDER. THIS LATTER SHORTWAVE WAS PRODUCING A
MASS OF CIRRUS ACROSS THE DAKOTAS INTO NORTHWEST MINNESOTA. DRY LOW
TO MID LEVELS SEEN ON THE 00Z MPX...ABR AND UNR SOUNDINGS HAS
PREVENTED ANY LOWER CLOUD DEVELOPMENT. REGARDING THE DRYNESS...BOTH
MPX AND ABR SOUNDINGS ONLY HAD PRECIPITABLE WATER VALUES OF 0.20
INCHES. FARTHER TO THE EAST...AN AREA OF LOW STRATUS WAS PRESENT
ACROSS MUCH OF GRBS FORECAST AREA INTO LOCATIONS ALONG/NORTHEAST OF
I-94 IN OUR AREA. THIS STRATUS FORMED FROM SOUTHEAST ADVECTION OF
MOISTURE OFF LAKE MICHIGAN UNDERNEATH A SUBSIDENCE INVERSION...
COMBINED WITH LIGHT WINDS AND CLEAR SKIES EARLIER IN THE EVENING. A
STRONGER SOUTH FLOW ON THE BACK SIDE OF HIGH PRESSURE OVER LOWER
MICHIGAN HAS HELPED KEEP THE REST OF THE AREA LOW CLOUD FREE. THIS
FLOW...WHICH STRENGTHENS HEADING WEST TOWARDS THE DAKOTAS...HAS BEEN
BRINGING WARMER AIR INTO THE REGION. RAP ANALYSIS SHOWED 925MB TEMPS
OF 7C AT MPX COMPARED TO 2C ON THE 00Z SOUNDING. SURFACE
TEMPERATURES HAVE REFLECTED THE WARM ADVECTION WITH READINGS FROM
THE MID 20S TO MID 30S...WARMEST WEST OF THE MISSISSIPPI RIVER.
TODAY AND TONIGHT...THE SHORTWAVE ALONG THE WYOMING/SOUTH DAKOTA
BORDER IS PROGGED TO LIFT INTO NORTHERN MINNESOTA TONIGHT. THE TRACK
IS SLIGHTLY FARTHER NORTH THAN 24 HOURS AGO. WITH THE FARTHER NORTH
TRACK...THERE SHOULD BE A LITTLE LESS CLOUDS. SOME OF THE CIRRUS
STILL LOOKS SLATED TO CROSS THE FORECAST AREA LATE THIS AFTERNOON
INTO THIS EVENING...WITH SOME ALTOSTRATUS PRODUCED BY ISENTROPIC
LIFT AFTER MIDNIGHT. PLENTY OF LOW LEVEL DRY AIR WILL RESULT IN A
CONTINUATION OF THE DRY FORECAST. ONLY OTHER CLOUD COVER OF NOTE IS
THE EARLY MORNING STRATUS OVER THE NORTHEAST PORTION OF THE FORECAST
AREA...WHICH SHOULD SHIFT NORTHEAST DURING THE MORNING WITH THE
INCREASING SOUTH TO SOUTHWEST 950-925MB FLOW. THIS FLOW IS PROGGED
TO REACH 25-30KT TODAY AS THE GRADIENT TIGHTENS. WITH PLENTY OF
SUN...EXPECT BREEZY CONDITIONS...PARTICULARLY ON THE HIGHER TERRAIN
WEST OF THE MISSISSIPPI RIVER WHICH IS MORE EXPOSED AND IN THE
TIGHTEST GRADIENT. THE BREEZE SHOULD PERSIST INTO TONIGHT WITH THE
STRENGTHENING OF THE LOW LEVEL JET...NOTED TOO BY 950-925MB WINDS
INCREASING TO 30-45KT. THESE WINDS WILL CONTINUE TO BRING WARMER AIR
INTO THE REGION WITH 925MB TEMPS INDICATED BETWEEN 4-6C AT 18Z.
THESE SUPPORT HIGHS IN THE LOW TO MID 50S. FOLLOWED A BLEND OF
GUIDANCE FOR LOWS TONIGHT WITH THE BREEZE AND PASSING CLOUDS HELPING
TO PRODUCE A WARMER NIGHT.
SUNDAY INTO SUNDAY NIGHT...ATTENTION FOCUSES TO THE SHORTWAVE OFF
THE CALIFORNIA COAST. GOOD MODEL AGREEMENT EXISTS THAT THIS
SHORTWAVE WILL LIFT INTO THE CENTRAL PLAINS BY LATE SUNDAY...THEN
INTO WESTERN PORTIONS OF MINNESOTA AND IOWA BY 12Z MONDAY. RIDGING
LOOKS TO DEVELOP OVER THE FORECAST AREA FOR A TIME AHEAD OF THIS
SHORTWAVE AND IN THE WAKE OF THE SHORTWAVE LIFTING OUT OF NORTHERN
MINNESOTA. SUBSIDENCE UNDER THE RIDGE SHOULD THIN CLOUDS OUT SOME
FOR MUCH OF THE DAY UNTIL LATE. THIS IS WHEN THE AREA BEGINS TO FEEL
THE MOISTURE ADVECTION EFFECTS AHEAD OF THE SHORTWAVE...WHICH WILL
START PRODUCING AN ALTOSTRATUS DECK IN THE EVENING ACROSS THE AREA.
FURTHER LOWERING OF CEILINGS WILL OCCUR THROUGH THE NIGHT AS
PRECIPITABLE WATER VALUES CLIMB FROM AROUND 0.5 INCH AT 00Z TO NEAR
0.75 INCHES AT 12Z MONDAY. ALTHOUGH MOISTURE INCREASES...THE
ISENTROPIC LIFT IS QUITE WEAK...FOCUSED MAINLY WEST OF A LINE FROM
MEDFORD TO LA CROSSE AND OELWEIN BETWEEN 06-12Z. HAVE MAINTAINED A
20-30 PERCENT CHANCE FOR THIS AREA AND TIME PERIOD...BUT GIVEN THE
WEAK LIFT SIGNATURE IT IS POSSIBLE ANY PRECIPITATION HOLDS OFF UNTIL
AFTER 12Z MONDAY AS SUGGESTED BY THE 17.00Z GFS/NAM. 17.00Z ECMWF IS
MORE ROBUST...THOUGH. WARMER 925MB TEMPS IN THE 5-7C RANGE AT 18Z
SUNDAY PLUS THE SOUTHERLY BREEZE AND SUN SHOULD YIELD HIGHS IN THE
MID TO UPPER 50S. A FEW LOCATIONS MAY REACH OR EXCEED 60...
ESPECIALLY IF MORE SUN OCCURS. EVEN A WARMER NIGHT SHOULD OCCUR
SUNDAY NIGHT WITH MORE MOISTURE...CLOUDS AND THE BREEZE. LOWS WEST
OF THE MISSISSIPPI RIVER MAY NOT DIP BELOW 40.
MONDAY AND MONDAY NIGHT...THE SHORTWAVE TROUGH OVER THE PLAINS
MODELS AGREE ON BRINGING IT ACROSS THE FORECAST AREA MONDAY EVENING.
AS THE TROUGH APPROACHES MONDAY...THE ISENTROPIC LIFT LOOKS TO
INCREASE A LITTLE...ENOUGH TO WARRANT PRECIPITATION CHANCES AS HIGH
AS 40 PERCENT. KEPT THESE CHANCES LOW BECAUSE BOTH THE 17.00Z GFS
AND NAM SHOW A DRY LOOK TO THEIR QPF FIELDS. THE ECMWF REMAINS THE
MOST ROBUST...THOUGH ITS LATEST 17.00Z RUN HAS A SLIGHTLY DRIER LOOK
THAN ITS PREVIOUS 16.12Z RUN. MUCH OF THE RAIN...IF IT OCCURS...
SHOULD BE EAST OF THE AREA BY 00Z. HOWEVER...HAVE MAINTAINED A 20
PERCENT CHANCE OVER FAR EASTERN AREAS FROM 00-06Z SINCE THERE IS
STILL WEAK ISENTROPIC LIFT INDICATED ON THE 290-295K SURFACES.
PLENTY OF CLOUDS ON MONDAY WILL PREVENT TEMPERATURES FROM RISING AS
MUCH COMPARED TO THE WEEKEND. HAVE FOLLOWED A BLEND OF GUIDANCE FOR
HIGHS. CLOUDS GRADUALLY CLEARING OUT WEST TO EAST MONDAY NIGHT PLUS
LIGHTER WINDS RESULTING FROM A WEAKER PRESSURE GRADIENT SHOULD ALLOW
TEMPERATURES TO DIP INTO THE 30S TO AROUND 40 AT MOST LOCATIONS.
.LONG TERM...TUESDAY THROUGH FRIDAY NIGHT
200 AM CST SAT NOV 17 2012
THE MAIN ISSUE IN THE LONG TERM FORECAST IS A VERY POTENT SHORTWAVE
COMING OUT OF THE NORTHEAST PACIFIC TROUGH AND ENTERING THE PACIFIC
NORTHWEST TUESDAY EVENING. ALL MODELS AGREE ON UPPER RIDGING
BUILDING AHEAD OF THE POTENT SHORTWAVE INTO THE FORECAST AREA
TUESDAY NIGHT...RESULTING IN A SURGE OF WARM AIR ADVECTING INTO THE
AREA. 925MB TEMPS CLIMB FROM AROUND 6C AT 18Z TUESDAY TO 10-12C AT
18Z WEDNESDAY. 850MB TEMP ANOMALIES ON WEDNESDAY ARE 1.5 STANDARD
DEVIATIONS ABOVE NORMAL. PLENTY OF SUN LOOKS TO OCCUR AT LEAST ON
WEDNESDAY...AND PERHAPS TUESDAY TOO DEPENDING ON WHEN LOW CLOUDS
CLEAR ASSOCIATED WITH THE MONDAY/MONDAY NIGHT SHORTWAVE.
THEREFORE...THERE SHOULD BE DECENT MIXING DESPITE THE SHORTER DAY
LENGTH. HAVE LEANED ON THE WARM SIDE OF GUIDANCE AS A RESULT...
ESPECIALLY WEDNESDAY WHEN HIGHER CONFIDENCE EXISTS OF FULL SUN AND A
SOUTHERLY BREEZE IS PRESENT. HIGHS WEDNESDAY COULD REACH OR EXCEED
60...ABOUT 20 DEGREES ABOVE NORMAL. DRY AIR IN PLACE WILL PREVENT
ANY PRECIPITATION WITH THE WARM ADVECTION...AND PERHAPS CLOUDS TOO.
AS WE HEAD INTO THANKSGIVING AND THROUGH FRIDAY NIGHT...THE 17.00Z
CANADIAN/ECMWF/GFS AND GFS ENSEMBLES ALL POINT TO THE POTENT
SHORTWAVE DIGGING SOUTHEAST THROUGH THE UPPER MISSISSIPPI RIVER
VALLEY REGION. THIS IS DIFFERENT FROM THE 16.12Z ECMWF AND 16.00Z
GFS WHICH HAD MORE OF A FLATTER...ZONAL FLOW. THUS...WE WILL SEE IF
THIS IDEA OF THE SHORTWAVE DIGGING INTO THE AREA CONTINUES WITH
LATER RUNS. NOTE THAT THE 17.00Z GFS ENSEMBLES ARE ALL OVER THE
PLACE WITH THIS FEATURE. IN ANY EVENT...RIGHT NOW THERE IS GOOD
AGREEMENT ON IT OCCURRING FROM THE DETERMINISTIC MODELS...BUT TIMING
VARIES FROM THANKSGIVING DAY TO FRIDAY. FOR NOW HAVE STUCK WITH A
CONSENSUS APPROACH WHICH BRINGS THE POTENT TROUGH IN THANKSGIVING
DAY NIGHT. THUS...THANKSGIVING STILL LOOKS WARM AHEAD OF A COLD
FRONT MOVING IN. HIGHS MOST LOCATIONS SHOULD END UP IN THE 50S.
COOLER CONDITIONS ARE LIKELY ON FRIDAY IN THE WAKE OF THE COLD FRONT
AS 850MB TEMPS PLUMMET DOWN TO AT OR BELOW 0C BY 00Z SATURDAY.
REGARDING THE COLD FRONTAL PASSAGE FOR PRECIPITATION...RIGHT NOW IT
APPEARS STILL THAT THE AIRMASS IS TOO DRY BOTH BEHIND AND AHEAD OF
THE FRONT TO ALLOW FOR ANYTHING TO OCCUR. ANY PRECIPITATION SHOULD
STAY TO THE NORTH...CLOSER TO THE BETTER DYNAMICS...AND TO THE
SOUTHEAST WHERE A LONGER PERIOD OF MOISTURE RETURN CAN OCCUR.
&&
.AVIATION...TODAY AND TONIGHT
540 AM CST SAT NOV 17 2012
THE COMBINATION OF LIGHT WINDS AND MOSTLY CLEAR SKIES ALLOWED
AREAS OF MVFR FOG TO DEVELOP ACROSS THE UPPER MISSISSIPPI RIVER
VALLEY OVERNIGHT. THE FOG WAS LOCALLY DENSE IN THE WISCONSIN AND
KICKAPOO RIVER VALLEYS AND IN CENTRAL WISCONSIN. THE SURFACE
PRESSURE GRADIENT IS EXPECTED TO TIGHTEN UP BETWEEN 17.12Z AND
17.14Z. AS THIS OCCURS...THE FOG WILL QUICKLY DISSIPATE.
FOR THE REMAINDER OF THE TODAY...SKIES WILL BE MAINLY CLEAR...AND
THEN THE MID AND HIGH CLOUDS WILL INCREASE TONIGHT AS A LOW
PRESSURE SYSTEM MOVES THROUGH NORTHERN MINNESOTA.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
200 AM CST SAT NOV 17 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...BOYNE
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
332 AM CST SAT NOV 17 2012
.TODAY AND TONIGHT...FORECAST CONFIDENCE IS MEDIUM TO HIGH.
TODAY...EXPANDED DENSE FOG ADVISORY TO COVER THE REMAINDER OF
SOUTHEAST WISCONSIN AND NORTHERN SOUTH CENTRAL WISCONSIN AS
STRATUS IS SPREADING NORTHEAST. ALSO EXTENDED END TIME TO 9 AM CST
AS FORECAST SOUNDINGS SHOW LITTLE MIXING UNTIL THEN.
TIMING OF FOG AND LOW CLOUD DISSIPATION THIS MORNING WILL HAVE AN
IMPACT ON HIGH TEMPERATURES TODAY. MODELS IN GOOD AGREEMENT THAT
925 MB TEMPERATURES WILL BE IN THE +5C TO +6C RANGE...WITH +7C IN
THE FAR WEST...BY MID TO LATE AFTERNOON. NAM/GFS MODEL SOUNDINGS
MIXING DRY ADIABATICALLY TO THESE TEMPS ARE YIELDING LOW TO MID
50S HIGHS.
HOWEVER...WITH WARM AIR ADVECTION ON SOUTHWEST WINDS INCREASING TO
20-25 KNOT WINDS AT/ABOVE 1K FT OVER WEAKER SOUTHEAST WINDS THAT
WILL BE KEEPING THE NEAR SURFACE AIR COOLER...THE RAP SOUNDINGS
NEVER FULLY MIX OUT THE BOUNDARY LAYER INVERSION TO REACH 925 MB.
WENT WITH A BLENDED SOLUTION THAT LEANS TOWARD THE WARM SIDE IN
THE CURRENT FOG-FREE AREAS IN THE WEST...AND IS COOLER EAST WHERE
THE COMBINATION OF EARLY FOG...AND SOUTHEAST WINDS OFF THE MID-
UPPER 40 DEGREE LAKE WATER WILL LIMIT HIGHS.
TONIGHT...GRADIENT SHOULD BE SUFFICIENT FOR SOUTHERLY WINDS TO
KEEP THE BOUNDARY LAYER MIXED AND PREVENT FOG TONIGHT. EXPECT ONLY
SOME MID-HIGH LEVEL CLOUDS WITH A WEAK SHORT WAVE CROSSING REGION
OVERNIGHT.
.SUNDAY THROUGH MONDAY NIGHT...FORECAST CONFIDENCE IS HIGH.
SOUTHWEST 500MB FLOW IS DEPICTED BY THE SHORT TERM MODELS ACROSS
THE REGION SUNDAY INTO MONDAY. SHORTWAVE TROUGH MOVES THROUGH THE
AREA FROM THE SOUTHWEST LATE SUNDAY NIGHT AND MONDAY...WITH A
TRAILING SHORTWAVE THEN SHIFTING EAST SOUTHEAST INTO THE AREA
MONDAY NIGHT. AT THE SURFACE...MILD SOUTHERLY FLOW CONTINUES
ACROSS THE REGION SUNDAY INTO MONDAY...WITH A SURFACE TROUGH
MOVING EASTWARD INTO THE AREA MONDAY NIGHT.
AREA FORECAST SOUNDINGS FROM NAM/GFS SHOW SOME MID TO HIGH CLOUDS
SUNDAY INTO SUNDAY NIGHT...WITH MORE CLOUDS MONDAY/MONDAY NIGHT
WITH PASSAGE OF SHORTWAVES AND SURFACE TROUGH. SOUNDINGS DO
INDICATE AIR COLUMN BECOMING MOIST IN THE LOW LEVELS MONDAY
NIGHT...BUT THE MID TO UPPER LEVELS DRY OUT. LIGHT QPF IS SEEN
ACROSS PORTIONS OF THE AREA MONDAY AND MONDAY NIGHT.
CONTINUED TO MENTION LOW END POPS FOR MONDAY AND MONDAY NIGHT.
TEMPERATURES WILL REMAIN ABOVE NORMAL...WITH HIGHS WELL INTO THE
50S SUNDAY AND MONDAY PER NAM 925MB TEMPERATURES. LOWS WILL
MODERATE FROM THE 30S SUNDAY NIGHT TO THE LOWER TO MID 40S MONDAY
NIGHT.
.TUESDAY THROUGH WEDNESDAY NIGHT...FORECAST CONFIDENCE IS HIGH.
GFS AND ECMWF SHOW GOOD AGREEMENT WITH FEATURES TUESDAY THROUGH
WEDNESDAY NIGHT. THEY SHOW THE SHORTWAVE TROUGH PUSHING THROUGH
AND EAST OF THE AREA TUESDAY. AREA GFS FORECAST SOUNDINGS SHOW
SOME LOW LEVEL MOISTURE LINGERING...BUT A DRY AIR COLUMN ABOVE IT.
KEPT LOW POPS TUESDAY MORNING IN THE FAR EAST/SOUTHEAST COUNTIES
IN THE MORNING...THEN DRY IN THE AFTERNOON.
BOTH MODELS THEN SHOW A 500MB RIDGE AXIS PASSING THROUGH THE AREA
TUESDAY NIGHT AND WEDNESDAY...WITH SOUTHWEST FLOW IN PLACE
WEDNESDAY NIGHT. SOUTH TO SOUTHWEST FLOW IN THE LOW LEVELS WITH
WARM AIR ADVECTION WILL OCCUR ACROSS THE REGION. AREA GFS FORECAST
SOUNDINGS REMAIN DRY DURING THIS TIME.
THUS...QUIET WEATHER IS EXPECTED TUESDAY NIGHT THROUGH WEDNESDAY
NIGHT...WITH ABOVE NORMAL TEMPERATURES CONTINUING. GIVEN THE
EXPECTED NAM 925MB TEMPERATURES...MAY REACH AS HIGH AS AROUND 60
ON WEDNESDAY.
.THANKSGIVING DAY THROUGH FRIDAY...FORECAST CONFIDENCE IS MEDIUM.
GFS AND ECMWF THEN DIFFER SOMEWHAT WITH FEATURES THURSDAY THROUGH
FRIDAY. THE GFS AND ECMWF BRING DEVELOPING LOW PRESSURE EAST FROM
NORTHERN MINNESOTA TO LAKE SUPERIOR THURSDAY...THEN NORTHEAST AS
IT BECOMES STRONGER THURSDAY NIGHT AND FRIDAY.
THE GFS HAS A COLD FRONT WITH LIGHT QPF MOVING EAST THROUGH THE
AREA THANKSGIVING DAY...FOLLOWED BY A STRONG VORTICITY MAXIMUM
PASSING THROUGH THURSDAY NIGHT INTO FRIDAY. THEY BOTH DO SHOW
BRISK WEST/NORTHWEST WINDS BRINGING COLDER AIR INTO THE REGION
THURSDAY NIGHT INTO FRIDAY. THE ECMWF BRINGS A DRY COLD FRONTAL
PASSAGE THURSDAY NIGHT. IT ALSO BRINGS A SECONDARY VORTICITY
MAXIMUM THROUGH THE AREA FRIDAY.
FOR NOW...WILL USE BLENDED POPS AND TEMPERATURES FOR THANKSGIVING
DAY THROUGH FRIDAY. THIS WILL MEAN DRY CONDITIONS AND CONTINUED
MILD TEMPERATURES. HIGHS THANKSGIVING DAY SHOULD REACH WELL INTO
THE 50S BEFORE THE FRONT MOVES THROUGH.
&&
.AVIATION/12Z TAFS/...WILL KEEP IFR/LIFR CONDITIONS AT AREA TAF
SITES UNTIL AT LEAST 13Z...AND POSSIBLY 14-15Z IN THE EAST...UNTIL
DAYTIME MIXING INCREASES WINDS AND RAISES CIGS AND VISIBILITIES.
SHOULD SEE VFR CONDITIONS ACROSS THE FORECAST AREA BY MID TO LATE
MORNING...WITH QUIET WEATHER THEN EXPECTED THROUGH THE REST OF THE
FORECAST PERIOD WITH VFR CONDITIONS.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR WIZ046-047-
051-052-057>060-063>066-068>072.
LM...NONE.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...REM
SUNDAY THROUGH FRIDAY...WOOD
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
200 AM CST SAT NOV 17 2012
.SHORT TERM...THROUGH MONDAY NIGHT
200 AM CST SAT NOV 17 2012
MAIN FORECAST CONCERNS ARE ON RAIN CHANCES SUNDAY NIGHT INTO MONDAY
NIGHT AS WELL AS TEMPERATURES THROUGHOUT.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED TROUGHING OFF BRITISH COLUMBIA...SUBTROPICAL RIDGING FROM
NORTHERN MEXICO TO LAKE ERIE...AND SHORTWAVES RIDING IN THE
SOUTHWEST SUBTROPICAL FLOW JUST OFF THE CALIFORNIA COAST AND NEAR
THE WY/SOUTH DAKOTA BORDER. THIS LATTER SHORTWAVE WAS PRODUCING A
MASS OF CIRRUS ACROSS THE DAKOTAS INTO NORTHWEST MINNESOTA. DRY LOW
TO MID LEVELS SEEN ON THE 00Z MPX...ABR AND UNR SOUNDINGS HAS
PREVENTED ANY LOWER CLOUD DEVELOPMENT. REGARDING THE DRYNESS...BOTH
MPX AND ABR SOUNDINGS ONLY HAD PRECIPITABLE WATER VALUES OF 0.20
INCHES. FARTHER TO THE EAST...AN AREA OF LOW STRATUS WAS PRESENT
ACROSS MUCH OF GRBS FORECAST AREA INTO LOCATIONS ALONG/NORTHEAST OF
I-94 IN OUR AREA. THIS STRATUS FORMED FROM SOUTHEAST ADVECTION OF
MOISTURE OFF LAKE MICHIGAN UNDERNEATH A SUBSIDENCE INVERSION...
COMBINED WITH LIGHT WINDS AND CLEAR SKIES EARLIER IN THE EVENING. A
STRONGER SOUTH FLOW ON THE BACK SIDE OF HIGH PRESSURE OVER LOWER
MICHIGAN HAS HELPED KEEP THE REST OF THE AREA LOW CLOUD FREE. THIS
FLOW...WHICH STRENGTHENS HEADING WEST TOWARDS THE DAKOTAS...HAS BEEN
BRINGING WARMER AIR INTO THE REGION. RAP ANALYSIS SHOWED 925MB TEMPS
OF 7C AT MPX COMPARED TO 2C ON THE 00Z SOUNDING. SURFACE
TEMPERATURES HAVE REFLECTED THE WARM ADVECTION WITH READINGS FROM
THE MID 20S TO MID 30S...WARMEST WEST OF THE MISSISSIPPI RIVER.
TODAY AND TONIGHT...THE SHORTWAVE ALONG THE WYOMING/SOUTH DAKOTA
BORDER IS PROGGED TO LIFT INTO NORTHERN MINNESOTA TONIGHT. THE TRACK
IS SLIGHTLY FARTHER NORTH THAN 24 HOURS AGO. WITH THE FARTHER NORTH
TRACK...THERE SHOULD BE A LITTLE LESS CLOUDS. SOME OF THE CIRRUS
STILL LOOKS SLATED TO CROSS THE FORECAST AREA LATE THIS AFTERNOON
INTO THIS EVENING...WITH SOME ALTOSTRATUS PRODUCED BY ISENTROPIC
LIFT AFTER MIDNIGHT. PLENTY OF LOW LEVEL DRY AIR WILL RESULT IN A
CONTINUATION OF THE DRY FORECAST. ONLY OTHER CLOUD COVER OF NOTE IS
THE EARLY MORNING STRATUS OVER THE NORTHEAST PORTION OF THE FORECAST
AREA...WHICH SHOULD SHIFT NORTHEAST DURING THE MORNING WITH THE
INCREASING SOUTH TO SOUTHWEST 950-925MB FLOW. THIS FLOW IS PROGGED
TO REACH 25-30KT TODAY AS THE GRADIENT TIGHTENS. WITH PLENTY OF
SUN...EXPECT BREEZY CONDITIONS...PARTICULARLY ON THE HIGHER TERRAIN
WEST OF THE MISSISSIPPI RIVER WHICH IS MORE EXPOSED AND IN THE
TIGHTEST GRADIENT. THE BREEZE SHOULD PERSIST INTO TONIGHT WITH THE
STRENGTHENING OF THE LOW LEVEL JET...NOTED TOO BY 950-925MB WINDS
INCREASING TO 30-45KT. THESE WINDS WILL CONTINUE TO BRING WARMER AIR
INTO THE REGION WITH 925MB TEMPS INDICATED BETWEEN 4-6C AT 18Z.
THESE SUPPORT HIGHS IN THE LOW TO MID 50S. FOLLOWED A BLEND OF
GUIDANCE FOR LOWS TONIGHT WITH THE BREEZE AND PASSING CLOUDS HELPING
TO PRODUCE A WARMER NIGHT.
SUNDAY INTO SUNDAY NIGHT...ATTENTION FOCUSES TO THE SHORTWAVE OFF
THE CALIFORNIA COAST. GOOD MODEL AGREEMENT EXISTS THAT THIS
SHORTWAVE WILL LIFT INTO THE CENTRAL PLAINS BY LATE SUNDAY...THEN
INTO WESTERN PORTIONS OF MINNESOTA AND IOWA BY 12Z MONDAY. RIDGING
LOOKS TO DEVELOP OVER THE FORECAST AREA FOR A TIME AHEAD OF THIS
SHORTWAVE AND IN THE WAKE OF THE SHORTWAVE LIFTING OUT OF NORTHERN
MINNESOTA. SUBSIDENCE UNDER THE RIDGE SHOULD THIN CLOUDS OUT SOME
FOR MUCH OF THE DAY UNTIL LATE. THIS IS WHEN THE AREA BEGINS TO FEEL
THE MOISTURE ADVECTION EFFECTS AHEAD OF THE SHORTWAVE...WHICH WILL
START PRODUCING AN ALTOSTRATUS DECK IN THE EVENING ACROSS THE AREA.
FURTHER LOWERING OF CEILINGS WILL OCCUR THROUGH THE NIGHT AS
PRECIPITABLE WATER VALUES CLIMB FROM AROUND 0.5 INCH AT 00Z TO NEAR
0.75 INCHES AT 12Z MONDAY. ALTHOUGH MOISTURE INCREASES...THE
ISENTROPIC LIFT IS QUITE WEAK...FOCUSED MAINLY WEST OF A LINE FROM
MEDFORD TO LA CROSSE AND OELWEIN BETWEEN 06-12Z. HAVE MAINTAINED A
20-30 PERCENT CHANCE FOR THIS AREA AND TIME PERIOD...BUT GIVEN THE
WEAK LIFT SIGNATURE IT IS POSSIBLE ANY PRECIPITATION HOLDS OFF UNTIL
AFTER 12Z MONDAY AS SUGGESTED BY THE 17.00Z GFS/NAM. 17.00Z ECMWF IS
MORE ROBUST...THOUGH. WARMER 925MB TEMPS IN THE 5-7C RANGE AT 18Z
SUNDAY PLUS THE SOUTHERLY BREEZE AND SUN SHOULD YIELD HIGHS IN THE
MID TO UPPER 50S. A FEW LOCATIONS MAY REACH OR EXCEED 60...
ESPECIALLY IF MORE SUN OCCURS. EVEN A WARMER NIGHT SHOULD OCCUR
SUNDAY NIGHT WITH MORE MOISTURE...CLOUDS AND THE BREEZE. LOWS WEST
OF THE MISSISSIPPI RIVER MAY NOT DIP BELOW 40.
MONDAY AND MONDAY NIGHT...THE SHORTWAVE TROUGH OVER THE PLAINS
MODELS AGREE ON BRINGING IT ACROSS THE FORECAST AREA MONDAY EVENING.
AS THE TROUGH APPROACHES MONDAY...THE ISENTROPIC LIFT LOOKS TO
INCREASE A LITTLE...ENOUGH TO WARRANT PRECIPITATION CHANCES AS HIGH
AS 40 PERCENT. KEPT THESE CHANCES LOW BECAUSE BOTH THE 17.00Z GFS
AND NAM SHOW A DRY LOOK TO THEIR QPF FIELDS. THE ECMWF REMAINS THE
MOST ROBUST...THOUGH ITS LATEST 17.00Z RUN HAS A SLIGHTLY DRIER LOOK
THAN ITS PREVIOUS 16.12Z RUN. MUCH OF THE RAIN...IF IT OCCURS...
SHOULD BE EAST OF THE AREA BY 00Z. HOWEVER...HAVE MAINTAINED A 20
PERCENT CHANCE OVER FAR EASTERN AREAS FROM 00-06Z SINCE THERE IS
STILL WEAK ISENTROPIC LIFT INDICATED ON THE 290-295K SURFACES.
PLENTY OF CLOUDS ON MONDAY WILL PREVENT TEMPERATURES FROM RISING AS
MUCH COMPARED TO THE WEEKEND. HAVE FOLLOWED A BLEND OF GUIDANCE FOR
HIGHS. CLOUDS GRADUALLY CLEARING OUT WEST TO EAST MONDAY NIGHT PLUS
LIGHTER WINDS RESULTING FROM A WEAKER PRESSURE GRADIENT SHOULD ALLOW
TEMPERATURES TO DIP INTO THE 30S TO AROUND 40 AT MOST LOCATIONS.
.LONG TERM...TUESDAY THROUGH FRIDAY NIGHT
200 AM CST SAT NOV 17 2012
THE MAIN ISSUE IN THE LONG TERM FORECAST IS A VERY POTENT SHORTWAVE
COMING OUT OF THE NORTHEAST PACIFIC TROUGH AND ENTERING THE PACIFIC
NORTHWEST TUESDAY EVENING. ALL MODELS AGREE ON UPPER RIDGING
BUILDING AHEAD OF THE POTENT SHORTWAVE INTO THE FORECAST AREA
TUESDAY NIGHT...RESULTING IN A SURGE OF WARM AIR ADVECTING INTO THE
AREA. 925MB TEMPS CLIMB FROM AROUND 6C AT 18Z TUESDAY TO 10-12C AT
18Z WEDNESDAY. 850MB TEMP ANOMALIES ON WEDNESDAY ARE 1.5 STANDARD
DEVIATIONS ABOVE NORMAL. PLENTY OF SUN LOOKS TO OCCUR AT LEAST ON
WEDNESDAY...AND PERHAPS TUESDAY TOO DEPENDING ON WHEN LOW CLOUDS
CLEAR ASSOCIATED WITH THE MONDAY/MONDAY NIGHT SHORTWAVE.
THEREFORE...THERE SHOULD BE DECENT MIXING DESPITE THE SHORTER DAY
LENGTH. HAVE LEANED ON THE WARM SIDE OF GUIDANCE AS A RESULT...
ESPECIALLY WEDNESDAY WHEN HIGHER CONFIDENCE EXISTS OF FULL SUN AND A
SOUTHERLY BREEZE IS PRESENT. HIGHS WEDNESDAY COULD REACH OR EXCEED
60...ABOUT 20 DEGREES ABOVE NORMAL. DRY AIR IN PLACE WILL PREVENT
ANY PRECIPITATION WITH THE WARM ADVECTION...AND PERHAPS CLOUDS TOO.
AS WE HEAD INTO THANKSGIVING AND THROUGH FRIDAY NIGHT...THE 17.00Z
CANADIAN/ECMWF/GFS AND GFS ENSEMBLES ALL POINT TO THE POTENT
SHORTWAVE DIGGING SOUTHEAST THROUGH THE UPPER MISSISSIPPI RIVER
VALLEY REGION. THIS IS DIFFERENT FROM THE 16.12Z ECMWF AND 16.00Z
GFS WHICH HAD MORE OF A FLATTER...ZONAL FLOW. THUS...WE WILL SEE IF
THIS IDEA OF THE SHORTWAVE DIGGING INTO THE AREA CONTINUES WITH
LATER RUNS. NOTE THAT THE 17.00Z GFS ENSEMBLES ARE ALL OVER THE
PLACE WITH THIS FEATURE. IN ANY EVENT...RIGHT NOW THERE IS GOOD
AGREEMENT ON IT OCCURRING FROM THE DETERMINISTIC MODELS...BUT TIMING
VARIES FROM THANKSGIVING DAY TO FRIDAY. FOR NOW HAVE STUCK WITH A
CONSENSUS APPROACH WHICH BRINGS THE POTENT TROUGH IN THANKSGIVING
DAY NIGHT. THUS...THANKSGIVING STILL LOOKS WARM AHEAD OF A COLD
FRONT MOVING IN. HIGHS MOST LOCATIONS SHOULD END UP IN THE 50S.
COOLER CONDITIONS ARE LIKELY ON FRIDAY IN THE WAKE OF THE COLD FRONT
AS 850MB TEMPS PLUMMET DOWN TO AT OR BELOW 0C BY 00Z SATURDAY.
REGARDING THE COLD FRONTAL PASSAGE FOR PRECIPITATION...RIGHT NOW IT
APPEARS STILL THAT THE AIRMASS IS TOO DRY BOTH BEHIND AND AHEAD OF
THE FRONT TO ALLOW FOR ANYTHING TO OCCUR. ANY PRECIPITATION SHOULD
STAY TO THE NORTH...CLOSER TO THE BETTER DYNAMICS...AND TO THE
SOUTHEAST WHERE A LONGER PERIOD OF MOISTURE RETURN CAN OCCUR.
&&
.AVIATION...
1030 PM CST FRI NOV 16 2012
LOW LEVEL MOISTURE REMAINS TRAPPED UNDER AN INVERSION OVER PARTS OF
CENTRAL/EASTERN WI LATE THIS EVENING...WITH HIGH PRESSURE CENTERED
OVERHEAD. RAP13/NAM12 SUGGEST EXPANSION OF A FOG/STRATUS LAYER
TONIGHT AS A RESULT....AND LATEST SATELLITE IMAGERY DEPICTS
THIS...BUT KEEPS IT ACROSS NORTHEAST WI. DON/T EXPECT AN IMPACT AT
KLSE.
THE HIGH WILL MOVE OFF TO THE EAST ON SATURDAY...LEADING TO A
TIGHTENING PRESSURE GRADIENT ACROSS THE UPPER MISSISSIPPI RIVER
VALLEY. WINDS WILL INCREASE AS A RESULT...WITH AFTERNOON MIXING
RESULTING IN SOME GUSTINESS. WINDS LOOK SIMILAR FOR SUNDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
200 AM CST SAT NOV 17 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS LINCOLN IL
327 AM CST MON NOV 19 2012
.DISCUSSION...
ISSUED 256 AM CST MON NOV 19 2012
OVERALL...NOT A LOT OF CHANGES IN THE FORECAST. MAIN ISSUES ARE
TWO PERIODS OF POTENTIAL PRECIP...AND UNSEASONABLY WARM
TEMPERATURES. PREDOMINANTLY ZONAL FLOW THROUGH THE FORECAST...WITH
A COUPLE OF WAVES ALTERING THE FLOW BRIEFLY. UPPER LOW MOVING JUST
OFF THE SERN ATLANTIC COAST...AND ANOTHER WAVE PUSHING SOME
SHOWERS OVER THE MISSISSIPPI RIVER VALLEY. FIRST ISSUE WILL BE THE
PROGRESSION OF THE SHOWERS INTO ILLINOIS TODAY. OTHER THAN
THAT...WARM TEMPS THROUGH THE FIRST HALF OF THE WEEK PUSHING THE
MAXES OVER GUIDANCE. NOT A LOT OF DISSENSION BETWEEN THE
MODELS...JUST WITH THE MOS. PUSHING FORECAST MORE TOWARDS RAW
SOLUTIONS AS A RESULT. NEXT SHOT AT SHOWERY PRECIP ON TRACK FOR
THANKSGIVING DAY.
SHORT TERM...TODAY AND TONIGHT...
SHOWERS MOVING INTO THE MISS RIVER VALLEY THIS MORNING. A BIT OF
CONFLICT IN HIGH RES MODELS AS TO WHETHER OR NOT IT WILL MAKE IT
INTO CENTRAL IL. HRRR SAYS YES...WITH A SECOND ROUND APPROACHING
FROM THE SW FOR A SECONDARY ENHANCEMENT MID MORNING. 4KM WRF IS A
BIT MORE CONSERVATIVE...NAM AND ECMWF ARE DRY. AS A RESULT...AND
AT LEAST TO COVER FOR SPRINKLES THROUGH THE MORNING WITH
REMNANTS...SLIGHT POPS DOMINATE THE WESTERN THIRD OF THE CWA. WILL
HAVE TO MONITOR CLOSELY...BUT SO FAR THE SOLUTION SEEMS PLENTY AS
THE COVERAGE OF THE SHOWERS IS REDUCING ON RADAR. SHORT LIVED
PRECIP NOT ENOUGH TO COUNTER THE WARM UP THAT CONTINUES TODAY AS
SOUTHERLY WINDS GET A BIT MORE ESTABLISHED THIS AFTERNOON. MILD
TEMPS CONTINUE INTO THE OVERNIGHT YET AGAIN.
LONG TERM...TUESDAY THROUGH SUNDAY...
HIGH PRESSURE RIDGE SLOWLY DRIFTS EASTWARD...OR AT LEAST BECOMES
FAR MORE DIFFUSE FROM THE MIDWEST TO THE SOUTHERN PLAINS...AND
THE CLOSED UPPER LOW KICKS OUT OF THE SE. THE WARMING TREND
CONTINUES THROUGH MID WEEK...BRINGING TEMPS UP A DEGREE OR SO EACH DAY.
850MB TEMPS AT 6-7C WILL HAVE THE POTENTIAL TO TRANSLATE INTO
UPPER 50S/LOWER 60S. GUIDANCE HAS NOT COMPLETELY LATCHED ONTO THE
WARMING TREND...THOUGH THE MODEL FIELDS CLEARLY SHOW THE THERMAL
RIDGE IN THE WESTERN CONUS DEEPENING AND SLOWLY CREEPING INTO THE
MIDWEST. HAVE BUMPED MAX TEMPS A FEW DEGREES AHEAD OF ALLBLEND FOR
MON- WED...AND A BIT ON THURSDAY. THURSDAY MAY BE COMPLICATED BY
AN APPROACHING STORM SYSTEM AND ASSOCIATED CLOUD COVER...BUT
SYSTEM STILL HAS A BIT OF UNCERTAINTY AS FAR AS MID AND LOW LEVEL
MOISTURE FIELDS. ALLBLEND PUSHING POPS TO CHANCE CAT.
HJS
&&
.AVIATION...
ISSUED 1143 PM CST SUN NOV 18 2012...FOR THE 06Z TAFS
VFR CONDITIONS ARE EXPECTED OVER THE NEXT 24 HOURS...WITH CLOUD
HEIGHTS GRADUALLY LOWERING WITH TIME BUT REMAINING ABOVE 3K FT
THROUGH 06Z TOMORROW NIGHT. AN UPPER LEVEL SHORTWAVE ARRIVING
LATER MONDAY AFTERNOON AND MON EVE WILL COINCIDE WITH INCREASING
LOWER LEVEL MOISTURE. HOWEVER...LITTLE IN THE WAY OF PRECIP IS
EXPECTED AS MID AND UPPER LEVEL MOISTURE DEPART EASTWARD AT THAT
SAME TIME. SPRINKLES MAY DEVELOP LATER MON AFTN/MON EVE...BUT
CONFIDENCE IS NOT HIGH ENOUGH TO INCLUDE A MENTION OF RAIN AT THIS
POINT.
WINDS WILL BE LIGHT SOUTHEAST THE REST OF THE NIGHT...THEN
INCREASE TO 10-13KT OUT OF THE SOUTH ON MONDAY...IN RESPONSE TO
A TIGHTENING PRESSURE GRADIENT.
NO REDUCTIONS TO VISIBILITY ARE EXPECTED OVER THE NEXT 24 HOURS.
SHIMON
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
326 AM CST MON NOV 19 2012
.SHORT TERM /TODAY/...
LIGHT SHOWERS THAT TRAVERSED THE AREA OVERNIGHT ARE ABOUT TO CLEAR
OUT TO THE EAST AND SHOULD BE OVER IN OUR CWA BEFORE 12Z. WILL
HANDLE THESE WITH A PRE FIRST PERIOD AND GO DRY TODAY.
OTHERWISE...SATELLITE IMAGERY INDICATES THAT THE CLOUDS OVERHEAD
WILL CLEAR MORE QUICKLY AND THOROUGHLY THAN IS INDICATED BY MOST
SHORT RANGE MODELS. HAVE THUS ACCELERATED CLEARING SKIES THIS
MORNING AND INCREASED FORECAST HIGH TEMPERATURES BY A COUPLE OF
DEGREES. DESPITE THE RELATIVELY LIGHT SOUTHERLY FLOW WE SHOULD WARM
UP PRETTY NICELY...ESPECIALLY GIVEN THAT 09Z TEMPERATURES ARE IN THE
MID 40S TO LOWER 50S ACROSS THE AREA...AND MAY STILL BE A LITTLE TOO
COOL TODAY BUT AT THE HIGH END OF OR ABOVE MOS GUIDANCE WILL NOT GET
TOO AGGRESSIVE WITH THE WARMING.
.LONG TERM /TONIGHT THROUGH SUNDAY/...
WARM PATTERN WILL CONTINUE WITH DRY CONDITIONS TUE AND WED. LITTLE
CHANGE IN THE THINKING OF THE PAST FEW DAYS WITH H8 TEMPS STILL
EXPECTED TO GET INTO THE +11 TO +14 RANGE ON WED. GIVEN CURRENT
FORECAST HIGHS FOR WED IN THE UPPER 60S TO LOW 70S...HAVE HEADLINED
THE NEAR RECORD HIGHS FOR WED. THU CONTINUES TO BE TRICKY WITH THE
APPROACHING COLD FRONT AND SOME MOISTURE PUSHING IN AHEAD OF IT.
MODELS HAVE BEEN CONSISTENT WITH THE CLOUD COVER AND EVEN SOME
SHOWERS ACROSS THE SOUTHEAST. TAKING THAT INTO ACCOUNT HAVE TEMPS
LAID OUT IN ACCORDANCE WITH THE ECMWF DEPICTION WITH WARMER TEMPS
RELATIVE TO SURROUNDING IN A BAND FROM THE SOUTHWEST INTO THE NORTH
CENTRAL. FIRST COLD FRONT WILL PUSH THROUGH LATE THU AND THU NIGHT.
GEM AND ECMWF BOTH DEPICT A GOOD SECONDARY COLD FRONT PUSHING SOUTH
ACROSS THE STATE ON FRI. THE GFS MISSED THIS FEATURE. FOR THAT
REASON WILL MAKE ADJUSTMENTS DOWN ON TEMPS FOR FRI...FRI NIGHT...AND
SAT. RETURN TO WARMER WEATHER HEADING INTO SUN AND MON...BUT DON`T
THINK IT WILL LAST ALL THAT LONG THIS TIME. HIGH LAT BLOCKING IS
BEGINNING TO TAKE PLACE IN THE KARA SEA AREA AND IS LIKELY TO BRIDGE
WITH THE EASTERN PACIFIC RIDGE...ALLOWING FOR DEVELOPMENT OF MORE
CROSS POLAR FLOW AND COLDER TEMPS FOR MUCH OF CONUS.
&&
.AVIATION...19/06Z
SHOWER ACTIVITY WILL CONTINUE TO PRESS EAST NORTHEAST OVERNIGHT AND
LOOKS TO END AT DSM BY 07Z AT THE LATEST. ALO/OTM WILL BE AFFECTED
BY THE SHOWERS PAST 08Z AND NOT ANTICIPATING MUCH AFTER 12Z MONDAY
MORNING. THE LATEST HRRR HAS SHOWERS ENDING BY 11Z.
OTHERWISE...EXPECT VFR CONDITIONS THROUGHOUT THE FORECAST WITH A
WIND SHIFT TO THE WEST NORTHWEST LATE MONDAY AFTERNOON INTO THE
EVENING AS A WEAK TROUGH MOVES THROUGH THE STATE.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...JUNGBLUTH
LONG TERM...MS NOV 12
AVIATION...PODRAZIK
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1143 PM CST SUN NOV 18 2012
...UPDATED AVIATION DISCUSSION...
.SHORT TERM /TONIGHT/...
SOUTH FLOW WILL CONTINUE AT THE SURFACE TONIGHT OVER IOWA AS A SHORT
WAVE TROUGH CURRENTLY ALONG THE EASTERN COLORADO AND NEW MEXICO
BORDERS LIFTS RAPIDLY INTO IOWA. A BAND OF UPWARD MOTION AHEAD OF
THE SHORT WAVE WILL QUICKLY DEVELOP CLOUD COVER AND A BAND OF LIGHT
SHOWERS THIS EVENING. LOW TO MID LEVEL MOISTURE WILL TAP INTO THE
SYSTEM AS WELL...BUT IT APPEARS TO BE A LITTLE LATE TO PRODUCE MUCH
IN THE WAY OF PRECIPITATION...ESPECIALLY IN THE NORTH AND WEST OF
I-35. FORECAST SOUNDINGS INDICATE INSTABILITY WILL BE SLIM TO
NONE...SO ONLY LIGHT SHOWERS ARE EXPECTED. LOOKING AT A NUMBER OF
HIGH-RESOLUTION MODEL SOLUTIONS...IT APPEARS THAT SOUTHEAST PORTIONS
OF THE FORECAST AREA HAVE THE HIGHEST LIKELIHOOD OF SEEING THE
SHOWERS...SO THE HIGHEST POPS ARE LOCATED THERE BEFORE THE FORCING
ALOFT BEGINS TO EXIT TO THE EAST TOWARD MORNING. DUE TO THE SOUTH
FLOW...CLOUD COVER AND INCREASING MOISTURE...OVERNIGHT LOWS SHOULD
BE UNIFORMLY WARMER THAN LAST NIGHT.
.LONG TERM /MONDAY THROUGH SUNDAY/...
LITTLE CHANGES THROUGHOUT THE EXTENDED WITH DRY CONDITIONS EXPECTED
THROUGHOUT THE ENTIRE FORECAST PERIOD...WITH THE EXCEPTION OF ANY
LIGHT LINGERING PRECIP INITIALLY MONDAY MORNING ACROSS THE EXTREME
EASTERN CWA. OTHERWISE UPPER RIDGING STILL EXPECTED TO BUILD INTO
THE AREA WITH H85 TEMPS CLIMBING INTO THE TEENS CELSIUS WEDNESDAY
IN SOUTHERLY FLOW THROUGHOUT THE LOW LEVELS. STILL ANTICIPATE
TEMPERATURES WELL ABOVE AVERAGE FOR WED...WITH UPPER RIDGE
FLATTENING INTO THE THANKSGIVING DAY AND A BIT OF A COOL DOWN. WEAK
SHORTWAVE TROUGH DIVE SOUTHEAST INTO MINNESOTA AND THE GREAT LAKES
REGION BY FRIDAY...BRINGING A BACK DOOR COLD FRONT INTO THE CWA WITH
ANY ASSOCIATED PRECIPITATION REMAINING NORTH AND EAST OF THE CWA.
FLOW REMAINS LESS AMPLIFIED INTO THE WEEKEND AND NEXT WEEK...BUT A
WEAK RIDGE EXPECTED TO BUILD BACK INTO THE REGION FOR SUNDAY WITH
TEMPS ALOFT APPROACHING +10C OR HIGHER AGAIN. THEREFORE EXPECT
ANOTHER WARMER DAY FOR SUNDAY...WITH THE UPPER LEVELS TRANSITIONING
TO MORE OF A WEST COAST TROUGH INTO NEXT WEEK SUGGESTING A TREND
TOWARD A MORE ACTIVE PATTERN JUST BEYOND THE CURRENT FORECAST
PERIOD.
&&
.AVIATION...19/06Z
SHOWER ACTIVITY WILL CONTINUE TO PRESS EAST NORTHEAST OVERNIGHT AND
LOOKS TO END AT DSM BY 07Z AT THE LATEST. ALO/OTM WILL BE AFFECTED
BY THE SHOWERS PAST 08Z AND NOT ANTICIPATING MUCH AFTER 12Z MONDAY
MORNING. THE LATEST HRRR HAS SHOWERS ENDING BY 11Z.
OTHERWISE...EXPECT VFR CONDITIONS THROUGHOUT THE FORECAST WITH A
WIND SHIFT TO THE WEST NORTHWEST LATE MONDAY AFTERNOON INTO THE
EVENING AS A WEAK TROUGH MOVES THROUGH THE STATE.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...JUNGBLUTH
LONG TERM...BEERENDS
AVIATION...PODRAZIK
AREA FORECAST DISCUSSION
NWS GOODLAND KS
225 AM MST MON NOV 19 2012
.SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 225 AM MST MON NOV 19 2012
LATEST WV IMAGERY AND RUC H5 ANALYSIS SHOW WESTERLY ZONAL FLOW IN
PLACE ACROSS THE US...WITH SEVERAL LOW AMPLITUDE SHORTWAVE TROUGHS
EMBEDDED WITHIN MEAN FLOW. NEAREST SHORTWAVE TROUGH CURRENTLY
EXTENDS ACROSS EASTERN KS...WITH SUBSIDENCE IN PLACE BEHIND THIS
FEATURE OVER WESTERN KS. A SURFACE TROUGH AXIS CURRENTLY EXTENDS FROM
THE DAKOTAS AND ACROSS WESTERN KS...JUST EAST OF THE CWA BORDER.
OVERALL PATTERN WILL REMAIN QUIET THROUGH THE SHORT TERM...WITH MAIN
STORM TRACK WELL NORTH OF THE CWA AND WEAK SOUTHERN TRACK FAVORING
AREAS SOUTH AND EAST OF OUR CWA. PROGRESSIVE ZONAL PATTERN
TRANSITIONING TO SHORTWAVE RIDGING BY TUE...AND A RETURN TO W-SW FLOW
BY WED NIGHT AS THIS RIDGE SHIFTS EAST AND A SHORT WAVE TROUGH MOVES
WITHIN THE VICINITY OF THE CWA. THERE IS GOOD LARGE SCALE ASCENT
ACROSS CENTRAL KS WITH THIS FEATURE...CLOSE TO OUR EASTERN CWA BORDER.
HOWEVER...MOISTURE PROFILES ARE VERY DRY ESPECIALLY THROUGH ABOUT
600MB. I DECIDED TO KEEP FORECAST DRY FOR NOW IN OUR EASTERN CWA
WITH A FEW SPRINKLES POSSIBLE AT MOST.
UNSEASONABLY WARM TEMPERATURES IN THE UPPER 60S/LOW 70S ARE EXPECTED
THE NEXT THREE DAYS...WITH THE WARMEST ON WED AS LEE TROUGH
STRENGTHENS ALONG KS/CO BORDER. WITH INCREASED AFTERNOON MIXING...WE
SHOULD SEE VERY LOW RH VALUES WED AFTERNOON. CURRENT TROUGH POSITION
KEEPS THE STRONGEST WINDS OVER THE EASTERN CWA WHERE HIGHER RH
VALUES SHOULD BE...SO IT STILL LOOKS LIKE WE WONT NEED A RFW. THIS
WILL PROBABLY NEED TO BE WATCHED SINCE IT COULD BE CLOSE.
.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 225 AM MST MON NOV 19 2012
THURSDAY THROUGH SUNDAY...NORTHERN STREAM SYSTEM WILL PUSH A COLD
FRONT THROUGH EARLY ON THANKSGIVING DAY. WINDS MAY NEED TO BE A
LITTLE STRONGER THAT WHAT THE CRH_INIT GAVE ME ON THURSDAY BUT
APPEAR IN THE BALL PARK. THIS WILL BE SOMETHING THAT UPCOMING SHIFTS
WILL NEED TO WATCH. THERE WILL BE COME COOL DOWN ON THURSDAY WITH
THE COOLEST TEMPERATURES TO ARRIVE ON FRIDAY. AFTER THAT...
TEMPERATURES WILL MODERATE UNTIL LATE SUNDAY WHEN THE NEXT COLD
FRONT WILL ARRIVE. MAIN STORM TRACK/LIFT/MOISTURE REMAIN WELL NORTH
OF THE AREA SO THE DRY FORECAST LOOKS FINE AS DOES ALL THE INIT
GRIDS THAT I WAS GIVEN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1000 PM MST SUN NOV 18 2012
VFR THROUGH THE PERIOD AT KGLD AND KMCK. SFC TROUGH TO MOVE
THROUGH WITH LIGHT W/NW WINDS BEHIND IT UNDER SCATTERED MID LEVEL
CLOUDINESS. FOR MONDAY N/NW WINDS 10KTS OR SO AT BOTH SITES BY
LATE MORNING AS TROUGH MOVES THROUGH. SOME HIGH LEVEL CLOUDS MOVE
IN DURING THE AFTERNOON.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...BULLER
AVIATION...99
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1111 PM CST Sun Nov 18 2012
...UPDATED AVIATION DISCUSSION...
.DISCUSSION...
Tonight - Monday:
The main challenges through this period are the timing/onset of
precipitation and the duration into the Monday period. Water vapor
imagery was showing the weak upper level disturbance moving out of
the Southern Rockies and into the Plains. Radar and visible/IR
imagery show what also may be a weak baroclinic zone across south
central to eastern Nebraska with a few light returns showing up on
radar. The GFS does indicate a slightly tighter theta-e gradient
aloft through this area. The radar returns are consistent with the
latest HRRR run, albeit a few hours delayed, which develops
precipitation in this area this afternoon. Precipitation should
increase in coverage across the eastern half of Kansas this evening
as the support from the upper wave moves into the region. Think that
the timing of precipitation in our western zones will be in the 2-3Z
window and persist for 4-6 hours as the whole area moves into our
eastern zones. It still looks like coverage will be in the 50% range
and precipitation totals will be less than a quarter inch for those
that do pick up rain. Precipitation still looks to be coming to end
by mid day Monday. There could potentially be a few sprinkles Monday
afternoon as another weak wave will be tracking into the area. But
models are in good agreement moving any QPF away from the area
during the afternoon so the chances of precipitation look too small
to mention at this time.
High temperatures on Monday will be restrained a bit in our eastern
zones as cloud cover will be exiting the area preventing a warm up
like our western zones are expected to see. Overall, highs will
range from the low to mid 60s in our west to the middle 50s in our
east.
Tuesday - Tuesday Night:
Quiet weather with above normal temperatures are expected this
period. High temperatures should climb into the 60s across the area
but may be inhibited by weak flow and limited mixing. Overnight lows
should be mild for this time of year with lows generally in the low
to mid 40s. With light winds overnight, some of our typical low
lying/ drainage areas may fall into the 30s.
CDB
Wednesday - Sunday:
Model consensus is a continuation of near to above average
temperatures during this period with little in the way of
precipitation. Travel day on Wednesday looks outstanding with
temperatures nearing the 70 degree mark possible in the far western
CWA.
Most of the focus is on Thursday/Thanksgiving. An upper level ridge
will exit the region on Wednesday as another impulse within the
southern stream lifts northeast from the Southern Rockies on
Thanksgiving. Despite a lack of low level moisture there is
increasing support from the GFS and ECMWF that sufficient mid level
Pacific moisture will be available for scattered light showers as a
weak cold front drops southeast through MO Thursday night. Have
nudged Thursday night pops up to chance category for the far
southern counties.
A large vortex over the Gulf of Alaska is expected to eject a
significant piece of energy eastward at the start of the period. The
resulting shortwave trough will dig/deepen southeast through the
Upper MS Valley and Great Lakes Thursday night/Friday. Any weather
with this feature will track to the north but a secondary cold front
will pass through on Friday and reinforce an intrusion of colder
air. Have gone along with model consensus on temperatures but the
trend is towards more cooling and can envision later forecasts
tweaking Friday`s temperatures downward some more.
Zonal flow through the mid levels and warm air advection in the
boundary layer will return for the dry weekend.
MJ
&&
.AVIATION...
As the upper disturbance moves through overnight, I expect the area
of precipitation over southeast Kansas to spread northeast. Out of
the three TAF sights, precipitation chances will be greatest at MKC,
less at MCI, and low enough not to mention at STJ. Still looks like
precipitation will end prior to sunrise. Expect VFR conditions to
prevail even in the light rain.
Bailey
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
WFO EAX
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1056 PM CST SUN NOV 18 2012
.AVIATION...06Z KGRI TAF. VFR CONDITIONS WILL CONTINUE AT THE
TERMINAL FOR THE NEXT 24 HOURS. EXPECT WINDS TO BECOME LIGHT AND
VARIABLE OVERNIGHT AS A SURFACE TROUGH TO THE WEST NUDGES
EASTWARD. AS THIS TROUGH SHIFTS FURTHER EAST DURING THE DAY ON
MONDAY...WINDS WILL EVENTUALLY BECOME WEST TO NORTHWESTERLY AFT
ABOUT 19/13Z. OTHER THAN THIS WIND SHIFT...CLEAR SKIES AND NO
VISIBILITY OBSTRUCTIONS ARE EXPECTED.
&&
.PREV DISCUSSION... /ISSUED 305 PM CST SUN NOV 18 2012/
SHORT TERM...THROUGH MONDAY AFTERNOON. OVERALL THE BENIGN WEATHER
PATTERN OF LATE CONTINUES THROUGH THE NEXT 24 HOURS...WITH THE
MAIN FAIRLY MINOR ISSUE CONSISTING OF THE POSSIBILITY OF SPRINKLES
ACROSS SOUTHEAST ZONES LATE THIS AFTERNOON INTO THIS EVENING.
20Z OBJECTIVE SURFACE ANALYSIS PLACES A GENERALLY NORTH-SOUTH
TROUGH AXIS RUNNING FROM WESTERN SD THROUGH THE NEB PANHANDLE AND
DOWN ALONG THE KS/CO BORDER...TRAILING SOUTH FROM A 1005MB LOW AT
THE WY/MT/SD INTERSECTION. MEANWHILE...AN EXPANSIVE RIDGE AXIS
CONTINUES TO DOMINATE MUCH OF THE EASTERN CONUS. THE CWA LIES
ALONG THE INTERFACE BETWEEN THESE TWO FEATURES...WITH A MODEST
PRESSURE GRADIENT AND DIURNAL MIXING GENERALLY INTO THE 900-875MB
RANGE DRIVING SOUTHERLY SUSTAINED BREEZES TYPICALLY 13-23 MPH WITH
GUSTS MAINLY 20-25 MPH. VISIBLE SATELLITE CONFIRMS A RATHER
HEALTHY COVERAGE OF MID-HIGH CLOUDS STREAMING
OVERHEAD...ESPECIALLY ACROSS THE SOUTHEAST 2/3 OF THE CWA. RADAR
EVEN SUGGESTS A FEW SPRINKLES MAY HAVE ALREADY FALLEN THIS
AFTERNOON ACROSS PARTS OF NUCKOLLS/THAYER/FILLMORE COUNTIES. THESE
CLOUDS SEEM TO BE HAVING A VARYING EFFECT ON TEMPS THIS
AFTERNOON...WITH BOTH KS ZONES AND NORTHERN ZONES IN NEB VERY MUCH
ON TRACK TO NEAR FORECAST HIGHS IN THE LOW-MID 60S...WHILE CENTRAL
AREAS INCLUDING THE TRI-CITIES MAY FALL A BIT SHORT AND STRUGGLE
TO REACH 60. THE CLOUDS HAVE LIKELY ALSO REDUCED MIXING SOMEWHAT
AND HELD DOWN WIND SPEEDS SLIGHTLY. WATER VAPOR IMAGERY AND SHORT
TERM MODEL DATA DEPICTS BROAD QUASI-ZONAL/SLIGHTLY SOUTHWESTERLY
FLOW ACROSS THE CENTRAL/WESTERN CONUS...WITH A PAIR OF FAIRLY
VIGOROUS SHORTWAVE TROUGHS TRANSLATING THROUGH THE NORTHERN
ROCKIES AND OFF THE PACIFIC NORTHWEST COAST. CLOSER TO HOME...A
MORE SUBTLE LOW AMPLITUDE MID LEVEL WAVE IS CURRENTLY LIFTING OUT
OF CO/WY...INTO NEB/KS...WITH THE MID-HIGH CLOUDS STREAMING OUT
AHEAD OF THIS WAVE LARGELY ASSOCIATED WITH A MODEST 70+KT 300MB
JET STREAK.
LATE THIS AFTERNOON INTO THIS EVENING...THIS LOW AMPLITUDE MID
LEVEL WAVE WILL CONTINUE TRACKING ACROSS THE HEART OF THE CENTRAL
PLAINS...WITH THE ONGOING BATCH OF MID-HIGH CLOUDS GRADUALLY
CLEARING THE CWA FROM WEST-EAST AND PAVING THE WAY FOR A CLEAR
OVERNIGHT. PRIOR TO THIS HOWEVER...THE MOISTURE-STARVED
DISTURBANCE WILL CONTINUE TO PROMOTE MODEST THETA-E ADVECTION
EVIDENT IN THE 850-700MB LAYER MAINLY OVER THE EASTERN HALVES OF
NEB/KS. DESPITE PLENTIFUL DRY AIR ESPECIALLY BELOW 700MB...WILL
MAINTAIN A CHANCE OF SPRINKLES THROUGH 10 PM FOR LOCATIONS
GENERALLY EAST OF A LINE FROM YORK-NELSON-OSBORNE...WITH
ESSENTIALLY ZERO RISK OF PRECIP ACROSS THE REMAINDER OF THE CWA.
DESPITE VARIOUS MODELS SUCH AS THE NAM/ECMWF/GFS KEEPING ALL QPF
EAST OF THE CWA INTO THIS EVENING...THE WEAK RADAR RETURNS ALREADY
OBSERVED WITHIN THE FAR SOUTHEAST CWA THIS AFTERNOON ALONG WITH
THE 1KM REFLECTIVITY PROGS FROM THE LATEST HRRR MAKE ME UNWILLING
TO COMPLETELY IGNORE SPRINKLE POTENTIAL...ALTHOUGH AGREE WITH
PREVIOUS FORECASTER THAT ANYTHING MEASURABLE SHOULD FOCUS WELL
EAST/SOUTHEAST OF THE LOCAL AREA. AS MENTIONED...THE OVERNIGHT
WILL FEATURE CLEAR SKIES...WHILE AT THE SURFACE...A WEAK TROUGH
WILL MOVE EASTWARD ACROSS MAINLY THE WESTERN 1/2 OF THE
CWA...TURNING LIGHT BREEZES NORTHWESTERLY IN ITS WAKE. TEMPS
OVERNIGHT COULD BE A BIT TRICKY...AS THE NORTHWEST COMPONENT
BEHIND THE SURFACE TROUGH COULD ACT TO HOLD THINGS UP...WHILE JUST
AHEAD OF THE TROUGH THE COMBINATION OF NEAR-CALM TO LIGHT
SOUTHERLY BREEZES AND CLEAR SKIES SHOULD PROMOTE AN EFFICIENT
DROP. FEEL THAT A BLEND OF 12Z MET/MAV GUIDANCE IS PROBABLY THE
BEST COMPROMISE...AND THUS WILL LOWER MOST OF THE CWA 2-3 DEGREES
FROM PREVIOUS FORECAST...BUT STILL KEEPING ALL BUT A FEW NORTHWEST
COUNTIES ABOVE FREEZING AND IN THE 33-37 RANGE. ALTHOUGH SUPPOSE
SOME HAZE OR LIGHT FOG IS NOT OUT OF THE QUESTION AROUND SUNRISE
ESPECIALLY ALONG THE TROUGH AXIS...AM NOT EXPECTING FOG TO BE
WORTHY OF A FORMAL MENTION IN THE FORECAST.
FOR THE MONDAY DAYTIME PERIOD...TRANQUIL...MOISTURE-STARVED QUASI-
ZONAL FLOW WILL CONTINUE ALOFT OVER THE CENTRAL PLAINS...AS THE
SHORTWAVE CURRENTLY AFFECTING THE AREA MOVES WELL OFF EAST TOWARD
THE GREAT LAKES...WHILE THE SOUTHERN FRINGES OF ANOTHER MID LEVEL
WAVE CENTERED OVER THE CANADIAN BORDER BRUSHES INTO WESTERN NEB
DURING THE AFTERNOON. WHILE THE MAJORITY OF THE DAY SHOULD REMAIN
QUITE SUNNY WITH ONLY A FEW PASSING SPLOTCHES OF HIGH CIRRUS...THE
MID-LATE AFTERNOON HOURS COULD FEATURE A BIT GREATER INCOMING
CIRRUS COVERAGE MAINLY OVER NORTHWEST ZONES ASSOCIATED WITH THE
APPROACHING SHORTWAVE TROUGH. AT THE SURFACE...THE TROUGH AXIS
ESSENTIALLY BISECTING THE AREA AT SUNRISE WILL CONTINUE PUSHING
SOUTHEAST THROUGH THE DAY. IN ITS WAKE...FAIRLY LIGHT BREEZES OF
ONLY AROUND 10 MPH FROM THE NORTH-NORTHWEST WILL PREVAIL. THESE
LIGHT WINDS WILL MAKE FOR PLEASANT CONDITIONS THANKS TO THE NEXT
IN A LONG STRETCH OF SEASONABLY WARM DAYS. MADE VERY LITTLE
CHANGE TO HIGH TEMPS...AND IF ANYTHING NUDGED SOME PLACES UP
ANOTHER DEGREE...AIMING FOR LOW 60S NORTHEAST...MID 60S CENTRAL
INCLUDING TRI-CITIES...AND UPPER 60S KS ZONES. THE OVERALL BIGGEST
CHANGE TO THE MONDAY GRIDS WAS TO DEWPOINTS...WHICH WERE LOWERED
4-7 DEGREES...WITH VALUES ONLY EXPECTED TO AVERAGE IN THE LOW-MID
30S IN MOST AREAS. EVEN SO...RELATIVE HUMIDITY VALUES SHOULD STILL
DROP NO LOWER THAN THE UPPER 20S...KEEPING FIRE DANGER QUITE LOW
THANKS TO THE LIGHT WINDS.
LONG TERM...STARTING 00Z TUESDAY. GUIDANCE FROM THE
OPERATIONAL GFS...GEFS-MEAN AND EC ALL CONTINUE TO SUGGEST MID
AND UPPER LEVEL JET ENERGY WILL REMAIN TO THE NORTH OF THE CENTRAL
PLAINS THROUGH THE LONG TERM FORECAST PERIOD. A MID LEVEL SHORT
WAVE IS EXPECTED TO PUSH ACROSS SOUTHERN CANADA AND THE NORTHERN
PLAINS DURING THE DAY THURSDAY...ALONG WITH A WEAK MID LEVEL
PERTURBATION WHICH IS EXPECTED PUSH ACROSS THE SOUTHERN PLAINS
ALSO ON THURSDAY. ALTHOUGH THESE MID LEVEL DISTURBANCES WILL
REMAIN NORTH AND SOUTH OF OUR REGION...AN ASSOCIATED LOW LEVEL
BAROCLINIC ZONE IS EXPECTED TO PUSH ACROSS OUR AREA DURING THE DAY
THURSDAY. THE OPERATIONAL GFS AND EC BOTH CONTINUE TO SUGGEST LOW
LEVEL CONVERGENCE AND RESULTANT FORCING WILL REMAIN WEAK ALONG
THIS BAROCLINIC ZONE. ALTHOUGH THERE COULD BE AN INCREASE IN MID
TO HIGH LEVEL CLOUDS AS THE MID LEVEL PERTURBATION PUSHES ACROSS
THE SOUTHERN PLAINS...AN OVERALL LACK IN KINEMATIC FORCING SHOULD
KEEP OUR AREA DRY THROUGHOUT THE LONG TERM FORECAST PERIOD.
LITTLE CHANGE IN THE LOW LEVEL AIRMASS TUESDAY THROUGH THURSDAY WILL
PRESENT SIMILAR TEMPERATURES EACH DAY...WITH HIGHS GENERALLY IN THE
60S AND LOWS IN THE 30S AND 40S...WHICH IS WELL ABOVE NORMAL FOR
THIS TIME OF YEAR. WEAK LOW LEVEL COLD AIR ADVECTION POST FROPA
BEGINNING THURSDAY NIGHT WILL THEN PRESENT SOMEWHAT COOLER WEATHER
TO FINISH OUT THE WEEK...WITH HIGHS GENERALLY IN THE 50S AND LOWS IN
THE 30S...STILL ABOVE NORMAL FOR THIS TIME OF YEAR.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...PFANNKUCH
LONG TERM...BRYANT
AVIATION...ROSSI
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
437 AM EST MON NOV 19 2012
.SYNOPSIS...
A STRONG RIDGE OF HIGH PRESSURE OVER THE EASTERN UNITED STATES WILL
KEEP THE REGION FAIR AND DRY FOR MOST OF THIS WEEK. IN GENERAL...
SUNNY DAYS AND COOL NIGHTS ARE EXPECTED WITH SOME PATCHY FOG. MUCH
COLDER WEATHER IS EXPECTED BY NEXT WEEKEND AS A POOL OF COLD
CANADIAN AIR SPILLS ACROSS THE GREAT LAKES AND ACROSS THE
NORTHEASTERN UNITED STATES.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LOW CLOUDS HAVE EXPANDED TO COVER MOST OF THE LAUREL HIGHLANDS AND
PORTIONS OF THE SOUTH CENTRAL MOUNTAINS THIS MORNING. PATCHY LOW
CLOUDS HAVE ALSO PROPOGATED INTO PARTS OF THE CENTRAL AND NORTHERN
MOUNTAINS AS WELL. THE EASTERLY FLOW AROUND THE CANADIAN MARITIME
STRONG SFC RIDGE CENTER AND LOW PRESSURE ORGANIZING ALONG THE
SOUTHEAST ATLANTIC COAST IS SHUNTING ENOUGH LOW LEVEL MOISTURE
WESTWARD AND UP AGAINST THE HIGHER TERRAIN OF SOUTH CENTRAL AND
CENTRAL PA IN THE PRESENCE OF WEAK VERTICAL MIXING TO PRODUCE THE
LOW CLOUDS. TEMPS UNDER THE STRATUS MODERATE TO THE LOWER TO
MIDDLE 30S...WHILE AREAS AWAY FROM THE STRATUS ARE IN THE UPPER
20S. PATCHY FOG IS ALSO PREVALENT IN THE CLEAR AREAS...WITH VSBYS
BETWEEN 3 AND 5 MILES THIS MORNING.
STRATO CU CLOUDS SHOULD PERSIST ACROSS THE CENT MTNS AND LAURELS
THROUGH LATE MORNING THE EASTERLY UPSLOPE FLOW OF LLVL MARINE AIR
CONTINUES. EARLY MORNING FOG WILL DECREASE BY MID MORNING...WHILE
THE STRATUS LARGELY DISSIPATES BY LATE MORNING. PARTLY TO MOSTLY
SUNNY SKIES WILL DEVELOP BY THE LATE MORNING NEAR AND TO THE EAST
OF A LINE FROM KIPT TO KSEG AND KMDT. HOWEVER...NAM12 OUTLIER
SOLUTION SHOWS STRATUS PERSISTING OVER THE LOWER SUSQ THROUGH THIS
AFTERNOON...WHILE LCL 3KM HRRR SHOWS DISSIPATING AFT 15Z. TEMPS
WILL HAVE TO BE WATCHED CLOSELY AS MORE EXPANSIVE AND PERSISTENT
LOW CLOUDS COULD HOLD DOWN MAXES ACROSS CENTRAL AND SOUTHWEST
PORTIONS OF CENTRAL PA.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
EXPECT MORE OF THE SAME TONIGHT INTO TUESDAY MORNING WITH AT LEAST
A COMPONENT OF RETURN/UPSLOPE FLOW ACTING TO PRODUCE AREAS OF LOW
CLOUDS WITH TIES TO THE LAUREL HIGHLANDS AND SOUTH CENTRAL
MOUNTAINS. SFC RIDGE AXIS REMAINS ANCHORED OVER EASTERN THIRD OF
PENNSYLVANIA TONIGHT AND TUESDAY...AND IT APPEARS THE EASTERLY
ATLANTIC FETCH WILL BECOME MORE NE TO SW ORIENTED BY 12Z TUE...
SO EXTENT OF STRATUS IS EXPECTED TO BE FAR LESS ON TUESDAY MORNING
THAN THIS MORNING...BUT WITH THE TYPICAL RIVER VALLEY FOG THAT
ACCOMPANIES STABLE STRATIFICATION OVER CENTRAL AND EASTERN PA.
MINS TONIGHT SHOULD RANGE FROM THE MID TO UPPER 20S ACROSS THE
NORTH TO THE LOWER 30S OVER THE SOUTHEAST. GENERALLY STAYED A FEW
TICKS ABOVE MOS...WHICH MAY BE UNDERDOING THE EXTENT OF FOG AND
LOW CLOUDS EARLY TUESDAY MORNING. HIGHS SHOULD MODERATE TO THE 50S
EVERYWHERE TUESDAY AFTERNOON.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
EXPECT A DIGGING TROUGH TO MOVE THROUGH EARLY WEDNESDAY. THIS
WILL BRING SOME SLIGHT CLOUDINESS AND THE RETURN FLOW OF MOISTURE
AROUND THE RIDGE MAY ADVECT ENOUGH MOISTURE NORTHWARD UP THE SPINE
OF THE APPALACHIANS TO PRODUCE A LIGHT SHOWER OVER PARTS OF THE
REGION TUESDAY NIGHT. HOWEVER ANY DOWNSLOPING SHOULD REDUCE THIS
MOISTURE AND ANY PRECIPITATION REMAINS A LOW PROBABILITY. HAVE
CONTINUED TO REDUCE POPS ACCORDINGLY. EXPECT MILD AND DRY WEATHER
WITH WARMER THAN NORMAL TEMPERATURES THROUGH THE WORK WEEK...WITH
MAX TEMPERATURES 5 TO 10 DEGREES WARMER THAN NORMAL.
THE NEXT CHANCE FOR MEASURABLE PRECIPITATION WILL BE LATE THIS
COMING WEEK AS A DEEP TROUGH MOVES IN FROM THE NORTHWEST. THE
MODELS CONTINUE TO BRING DEEP COLD AIR IN BEHIND THE FRONT...WITH
-7C 850MB TEMPS POSSIBLE NEXT SATURDAY NIGHT. EXPECT TEMPERATURES
NEXT WEEKEND TO BE BELOW NORMAL...WITH RAIN SHOWERS POSSIBLE OUT
AHEAD OF THE FRONT...FOLLOWED BY A RIBBON OF MIXED
PRECIPITATION...AND SNOW SHOWERS BEHIND. THERE IS TO MUCH
VARIABILITY TO GIVE A GOOD QUANTIFICATION OF SNOW AMOUNTS.
HOWEVER...CURRENTLY ANY ACCUMULATIONS SEEM TO BE LIGHT. THE EC
CONTINUES TO SLOWS THE SYSTEM DOWN...ABOUT 12 HRS SLOWER THAN THE
GFS. HOWEVER BOTH MODELS HAVE A SIMILAR ORIENTATION..THOUGH THE EC
HAS A DEEPER LOW THAT IS FURTHER SOUTH.
&&
.AVIATION /10Z MONDAY THROUGH FRIDAY/...
SOME LOWER CIGS OVER SOUTHERN PA...STILL CLEAR TO THE NORTH.
LOW CLDS MAY MOVE A LITTLE FURTHER NORTH...BEFORE BURNING OFF
BETWEEN 14 AND 15Z.
OTHERWISE...HIGH PRESSURE ACROSS EASTERN CANADA AND THE NEW
ENGLAND STATES WILL REMAIN NEARLY STATIONY FOR THE NEXT FEW
DAYS...BRINGING MAINLY CLEAR SKIES TO THE AREA.
OUTLOOK...
WED...PATCHY AM VALLEY FOG POSSIBLE ACROSS THE ALLEGHENIES.
THU-FRI...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DEVOIR
NEAR TERM...DEVOIR/LAMBERT
SHORT TERM...DEVOIR/LAMBERT
LONG TERM...DEVOIR/CERU
AVIATION...FITZGERALD/MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
403 AM EST MON NOV 19 2012
.SYNOPSIS...
A STRONG RIDGE OF HIGH PRESSURE OVER THE EASTERN UNITED STATES WILL
KEEP THE REGION FAIR AND DRY FOR MOST OF THIS WEEK. IN GENERAL...
SUNNY DAYS AND COOL NIGHTS ARE EXPECTED WITH SOME PATCHY FOG. MUCH
COLDER WEATHER IS EXPECTED BY NEXT WEEKEND AS A POOL OF COLD
CANADIAN AIR SPILLS ACROSS THE GREAT LAKES AND ACROSS THE
NORTHEASTERN UNITED STATES.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LOW CLOUDS HAVE EXPANDED TO COVER MOST OF THE LAUREL HIGHLANDS AND
PORTIONS OF THE SOUTH CENTRAL MOUNTAINS THIS MORNING. PATCHY LOW
CLOUDS HAVE ALSO PROPOGATED INTO PARTS OF THE CENTRAL AND NORTHERN
MOUNTAINS AS WELL. THE EASTERLY FLOW AROUND THE CANADIAN MARITIME
STRONG SFC RIDGE CENTER AND LOW PRESSURE ORGANIZING ALONG THE
SOUTHEAST ATLANTIC COAST IS SHUNTING ENOUGH LOW LEVEL MOISTURE
WESTWARD AND UP AGAINST THE HIGHER TERRAIN OF SOUTH CENTRAL AND
CENTRAL PA IN THE PRESENCE OF WEAK VERTICAL MIXING TO PRODUCE THE
LOW CLOUDS. TEMPS UNDER THE STRATUS MODERATE TO THE LOWER TO
MIDDLE 30S...WHILE AREAS AWAY FROM THE STRATUS ARE IN THE UPPER
20S. PATCHY FOG IS ALSO PREVALENT IN THE CLEAR AREAS...WITH VSBYS
BETWEEN 3 AND 5 MILES THIS MORNING.
STRATO CU CLOUDS SHOULD PERSIST ACROSS THE CENT MTNS AND LAURELS
THROUGH LATE MORNING THE EASTERLY UPSLOPE FLOW OF LLVL MARINE AIR
CONTINUES. EARLY MORNING FOG WILL DECREASE BY MID MORNING...WHILE
THE STRATUS LARGELY DISSIPATES BY LATE MORNING. PARTLY TO MOSTLY
SUNNY SKIES WILL DEVELOP BY THE LATE MORNING NEAR AND TO THE EAST
OF A LINE FROM KIPT TO KSEG AND KMDT. HOWEVER...NAM12 OUTLIER
SOLUTION SHOWS STRATUS PERSISTING OVER THE LOWER SUSQ THROUGH THIS
AFTERNOON...WHILE LCL 3KM HRRR SHOWS DISSIPATING AFT 15Z. TEMPS
WILL HAVE TO BE WATCHED CLOSELY AS MORE EXPANSIVE AND PERSISTENT
LOW CLOUDS COULD HOLD DOWN MAXES ACROSS CENTRAL AND SOUTHWEST
PORTIONS OF CENTRAL PA.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
EXPECT MORE OF THE SAME TONIGHT INTO TUESDAY MORNING WITH AT LEAST
A COMPONENT OF RETURN/UPSLOPE FLOW ACTING TO PRODUCE AREAS OF LOW
CLOUDS WITH TIES TO THE LAUREL HIGHLANDS AND SOUTH CENTRAL
MOUNTAINS. SFC RIDGE AXIS REMAINS ANCHORED OVER EASTERN THIRD OF
PENNSYLVANIA TONIGHT AND TUESDAY...AND IT APPEARS THE EASTERLY
ATLANTIC FETCH WILL BECOME MORE NE TO SW ORIENTED BY 12Z TUE...
SO EXTENT OF STRATUS IS EXPECTED TO BE FAR LESS ON TUESDAY MORNING
THAN THIS MORNING...BUT WITH THE TYPICAL RIVER VALLEY FOG THAT
ACCOMPANIES STABLE STRATIFICATION OVER CENTRAL AND EASTERN PA.
MINS TONIGHT SHOULD RANGE FROM THE MID TO UPPER 20S ACROSS THE
NORTH TO THE LOWER 30S OVER THE SOUTHEAST. GENERALLY STAYED A FEW
TICKS ABOVE MOS...WHICH MAY BE UNDERDOING THE EXTENT OF FOG AND
LOW CLOUDS EARLY TUESDAY MORNING. HIGHS SHOULD MODERATE TO THE 50S
EVERYWHERE TUESDAY AFTERNOON.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
EXPECT A DIGGING TROUGH TO MOVE THROUGH EARLY WEDNESDAY. THIS
WILL BRING SOME SLIGHT CLOUDINESS AND THE RETURN FLOW OF MOISTURE
AROUND THE RIDGE MAY ADVECT ENOUGH MOISTURE NORTHWARD UP THE SPINE
OF THE APPALACHIANS TO PRODUCE A LIGHT SHOWER OVER PARTS OF THE
REGION TUESDAY NIGHT. HOWEVER ANY DOWNSLOPING SHOULD REDUCE THIS
MOISTURE AND ANY PRECIPITATION REMAINS A LOW PROBABILITY. HAVE
CONTINUED TO REDUCE POPS ACCORDINGLY. EXPECT MILD AND DRY WEATHER
WITH WARMER THAN NORMAL TEMPERATURES THROUGH THE WORK WEEK...WITH
MAX TEMPERATURES 5 TO 10 DEGREES WARMER THAN NORMAL.
THE NEXT CHANCE FOR MEASURABLE PRECIPITATION WILL BE LATE THIS
COMING WEEK AS A DEEP TROUGH MOVES IN FROM THE NORTHWEST. THE
MODELS CONTINUE TO BRING DEEP COLD AIR IN BEHIND THE FRONT...WITH
-7C 850MB TEMPS POSSIBLE NEXT SATURDAY NIGHT. EXPECT TEMPERATURES
NEXT WEEKEND TO BE BELOW NORMAL...WITH RAIN SHOWERS POSSIBLE OUT
AHEAD OF THE FRONT...FOLLOWED BY A RIBBON OF MIXED
PRECIPITATION...AND SNOW SHOWERS BEHIND. THERE IS TO MUCH
VARIABILITY TO GIVE A GOOD QUANTIFICATION OF SNOW AMOUNTS.
HOWEVER...CURRENTLY ANY ACCUMULATIONS SEEM TO BE LIGHT. THE EC
CONTINUES TO SLOWS THE SYSTEM DOWN...ABOUT 12 HRS SLOWER THAN THE
GFS. HOWEVER BOTH MODELS HAVE A SIMILAR ORIENTATION..THOUGH THE EC
HAS A DEEPER LOW THAT IS FURTHER SOUTH.
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
HIGH PRESSURE PROVIDING SKIES AND LGT WINDS ACROSS MOST OF CENTRAL
PA LATE THIS EVENING.
HOWEVER...SATL LOOP SHOWS AN AREA OF STRATOCU EXPANDING WESTWARD
ACROSS SOUTHERN PA...THE RESULT OF AN EASTERLY FLOW OF RELATIVELY
MOIST AIR FROM THE ATLANTIC. LATEST NARRE/SREF DATA BOTH INDICATE
MOISTURE FROM THIS EASTERLY FLOW WILL BANK AGAINST THE ALLEGHENY
MTNS OVERNIGHT...CREATING THE LIKELIHOOD OF EITHER IFR CIGS OR FOG
OVR PORTIONS OF THE LAUREL HIGHLANDS AND SC MTNS. BOTH JST AND AOO
COULD POTENTIALLY SEE IFR CONDS EARLY MON AM...MAINLY BTWN 08Z-
14Z.
ADDED LOWER CIGS AT LNS...ALREADY IN THAT AREA.
ELSEWHERE ACROSS CENTRAL PA...PATCHY VALLEY FOG IS LIKELY AFTER
MIDNIGHT...BUT ESP BTWN 09Z-14Z. HOWEVER...CURRENT DWPT DEPRESSIONS
AND CONDITIONAL CLIMATOLOGY SUGGEST PREDOMINATE VSBYS AT
BFD...IPT...UNV...MDT AND LNS WILL REMAIN ABV 3SM.
ANY VALLEY FOG /OR LOW CIGS ACROSS THE LAURELS/ SHOULD LIFT BY
LATE MORNING...TYPICALLY 14Z-15Z THIS TIME OF YEAR. BY AFTN...THE
ENTIRE REGION SHOULD BE UNDER VFR CONDS AND LIGHT WINDS.
OUTLOOK...
TUE...PATCHY AM VALLEY FOG POSSIBLE ACROSS THE ALLEGHENIES.
WED-FRI...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DEVOIR
NEAR TERM...DEVOIR/LAMBERT
SHORT TERM...DEVOIR/LAMBERT
LONG TERM...DEVOIR/CERU
AVIATION...FITZGERALD/MARTIN
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1149 PM CST SUN NOV 18 2012
.DISCUSSION...
SEE THE 12Z AVIATION DISCUSSION BELOW.
&&
.AVIATION...
PATCHY MVFR CIGS HAVE DEVELOPED AT KSOA AND KSJT IN THE PAST HOUR
BUT REMAIN TRANSIENT FOR THE MOST PART AS THE DEVELOPING LOW LEVEL
JET WORKS TO MIX THE BOUNDARY LAYER. I DO EXPECT THE CURRENT
STRATUS OVER THE CWA TO DISSIPATE WITH TIME AS IT ADVECTS NORTH.
ADDITIONAL LOW CIGS ARE EXPECTED TO DEVELOP LATER TONIGHT AND
SPREAD NORTH INTO THE MORNING HOURS. WE MAY SEE SOME BRIEF IFR
CIGS AROUND OR AFTER 12Z BUT I THINK THE PREVAILING CIG TYPE WILL
BE MVFR. CIGS WILL ERODE BY LATE MORNING...GIVING WAY TO VFR
CONDITIONS THROUGH THE REMAINDER OF THE TAF PERIOD. LIGHT SOUTH
WINDS TONIGHT WILL INCREASE TO 10-12 KTS ON MONDAY WITH OCCASIONAL
GUSTS NEAR 20 KTS AROUND MIDDAY.
JOHNSON
&&
.PREV DISCUSSION... /ISSUED 1018 PM CST SUN NOV 18 2012/
UPDATE...
THE LATEST MODEL AND RADAR DATA INDICATE THE POTENTIAL FOR SHOWERS
HAS ENDED ACROSS WEST CENTRAL TEXAS FOR THE REMAINDER OF TONIGHT.
THE LATEST WSR-88D DATA INDICATE SHOWERS HAVE ENDED ACROSS WEST
CENTRAL TEXAS. PLUS...THE LATEST RUC SHOWS LITTLE IF ANY CHANCE
FOR CONTINUED SHOWERS TONIGHT. THUS...I HAVE REDUCED POPS GRIDS
FOR THE REMAINDER OF TONIGHT TO 10 PERCENT...AND I REMOVED ALL
WEATHER FROM THE TONIGHT WEATHER GRIDS. IN ADDITION...I ADJUSTED
SKY GRIDS FOR THE REMAINDER OF TONIGHT BASED ON SATELLITE IMAGERY
AND MODELS DATA. RECENT PRODUCT UPDATES REFLECT THESE CHANGES.
OTHERWISE...NO OTHER CHANGES TO THE FORECAST.
HUBER
PREV DISCUSSION... /ISSUED 537 PM CST SUN NOV 18 2012/
DISCUSSION...
SEE THE 00Z AVIATION DISCUSSION BELOW.
AVIATION...
VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH AT LEAST 06Z
TONIGHT WITH LOW CLOUDS DEVELOPING AROUND 08-09Z AND PERSISTING
INTO THE LATE MORNING TO EARLY AFTERNOON HOURS. AS USUAL...THE NAM
IS THE MOST PESSIMISTIC MODEL REGARDING CEILING HEIGHTS /SHOWING
IFR/. BASED ON THE NAM/S BIAS OF BEING TO AGGRESSIVE WITH CIGS...
I RAISED THE FORECAST CATEGORIES TO LOW END MVFR EVERYWHERE
EXCLUDING KSOA /WHERE IFR CIGS WERE MAINTAINED/. LOW CLOUDS WILL
HANG ON THE LONGEST AT KBBD/KJCT AS VEERING LOW LEVEL DRIES OUT
KSJT/KSOA BY LATE MORNING. AT THIS TIME...IT LOOKS LIKE KABI MAY
AVOID LOW CIGS AGAIN TONIGHT. WINDS WILL BE PREDOMINANTLY FROM THE
SOUTH AT 12 KTS OR LESS...ALTHOUGH A FEW GUSTS NEAR 20 KTS WILL BE
POSSIBLE MONDAY AFTERNOON.
JOHNSON
PREV DISCUSSION... /ISSUED 404 PM CST SUN NOV 18 2012/
SHORT TERM...
FOR THE MOST PART I MADE ONLY MINOR CHANGES TO THE FORECAST. AS I
MENTIONED IN THE UPDATE EARLIER I INCREASED THE AFTERNOON HIGH
TEMPERATURES AS CLOUD COVER ARRIVED LATER THAN WE THOUGHT IT
WOULD. THIS CLOUD COVER WILL HAVE A TWO FOLD EFFECT ON THE
TEMPERATURES. AFTERNOON HIGHS ARE EXPECTED TO BE MILD AND THE
OVERNIGHT LOWS WILL ONLY DROP TO NEAR 50 DEGREES WHICH IS ABOUT 10
DEGREES ABOVE NORMAL.
PRECIPITATION CHANCES END TONIGHT AS THE SHORTWAVE TROUGH EXITS
WEST CENTRAL TEXAS. WITH THE DEPARTURE OF THE SHORTWAVE AN UPPER
LEVEL ZONAL PATTERN EMERGES AND DOMINATES THE FORECAST AREA. AS
THE CLOUDS BEGIN TO CLEAR TOMORROW MORNING...THE AFTERNOON HIGHS
ARE EXPECTED TO BE NEAR 70 DEGREES AREA WIDE.
18
LONG TERM...
GFS AND EC MODELS ARE IN GOOD AGREEMENT...WITH AN UPPER SHORTWAVE
MOVING EAST ACROSS WEST CENTRAL TEXAS...WEDNESDAY NIGHT AND
THURSDAY. A WEAK COLD FRONT FRIDAY THEN MOVES THROUGH FRIDAY.
ISOLATED SHOWERS AND PERHAPS AN ISOLATED THUNDERSTORM POSSIBLE
DURING THIS PERIOD. WITH ONLY WEAK INSTABILITY HOWEVER...GFS HAS
MUCAPES OF 100 TO 300 J/KG FRIDAY AND NONE EARLIER ON THURSDAY...
AND LIMITED MID LEVEL LAPSE RATES OF 6.5 TO 7.5 C/KM...NOT
EXPECTING MUCH THUNDER. RAINFALL AMOUNTS EXPECTED TO BE LIGHT
THURSDAY AND THURSDAY NIGHT...BUT MAY SEE HEAVIER AMOUNTS AS COLD
FRONT MOVES THROUGH SOUTHERN SECTIONS FRIDAY...MAINLY CONCHO
VALLEY AND SOUTHWARD.
GFS AND EC MODELS DIFFER THIS WEEKEND. GFS BRINGS IN AN BROAD
UPPER TROUGH WHILE THE EC HAS A BROAD WEAK RIDGING. WHILE THE GFS
PRECIPITATION ALGORITHM SOME RAIN...WILL HOLD ON MENTIONING
RAINFALL CHANCES WITH MODEL DIFFERENCES AND NORMAL LOWER CONFIDENCE
IN THE LONG TERM.
04
&&
.PRELIMINARY POINT TEMPS/POPS...
ABILENE 51 70 49 73 50 / 10 5 10 5 0
SAN ANGELO 50 72 51 73 50 / 10 5 10 5 5
JUNCTION 53 70 52 75 51 / 10 5 10 5 5
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
25
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1018 PM CST SUN NOV 18 2012
.UPDATE...
THE LATEST MODEL AND RADAR DATA INDICATE THE POTENTIAL FOR SHOWERS
HAS ENDED ACROSS WEST CENTRAL TEXAS FOR THE REMAINDER OF TONIGHT. THE
LATEST WSR-88D DATA INDICATE SHOWERS HAVE ENDED ACROSS WEST CENTRAL
TEXAS. PLUS...THE LATEST RUC SHOWS LITTLE IF ANY CHANCE FOR
CONTINUED SHOWERS TONIGHT. THUS...I HAVE REDUCED POPS GRIDS FOR THE
REMAINDER OF TONIGHT TO 10 PERCENT...AND I REMOVED ALL WEATHER
FROM THE TONIGHT WEATHER GRIDS. IN ADDITION...I ADJUSTED SKY GRIDS
FOR THE REMAINDER OF TONIGHT BASED ON SATELLITE IMAGERY AND MODELS
DATA. RECENT PRODUCT UPDATES REFLECT THESE CHANGES. OTHERWISE...NO
OTHER CHANGES TO THE FORECAST.
HUBER
&&
.PREV DISCUSSION... /ISSUED 537 PM CST SUN NOV 18 2012/
DISCUSSION...
SEE THE 00Z AVIATION DISCUSSION BELOW.
AVIATION...
VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH AT LEAST 06Z
TONIGHT WITH LOW CLOUDS DEVELOPING AROUND 08-09Z AND PERSISTING
INTO THE LATE MORNING TO EARLY AFTERNOON HOURS. AS USUAL...THE NAM
IS THE MOST PESSIMISTIC MODEL REGARDING CEILING HEIGHTS /SHOWING
IFR/. BASED ON THE NAM/S BIAS OF BEING TO AGGRESSIVE WITH CIGS...
I RAISED THE FORECAST CATEGORIES TO LOW END MVFR EVERYWHERE
EXCLUDING KSOA /WHERE IFR CIGS WERE MAINTAINED/. LOW CLOUDS WILL
HANG ON THE LONGEST AT KBBD/KJCT AS VEERING LOW LEVEL DRIES OUT
KSJT/KSOA BY LATE MORNING. AT THIS TIME...IT LOOKS LIKE KABI MAY
AVOID LOW CIGS AGAIN TONIGHT. WINDS WILL BE PREDOMINANTLY FROM THE
SOUTH AT 12 KTS OR LESS...ALTHOUGH A FEW GUSTS NEAR 20 KTS WILL BE
POSSIBLE MONDAY AFTERNOON.
JOHNSON
PREV DISCUSSION... /ISSUED 404 PM CST SUN NOV 18 2012/
SHORT TERM...
FOR THE MOST PART I MADE ONLY MINOR CHANGES TO THE FORECAST. AS I
MENTIONED IN THE UPDATE EARLIER I INCREASED THE AFTERNOON HIGH
TEMPERATURES AS CLOUD COVER ARRIVED LATER THAN WE THOUGHT IT
WOULD. THIS CLOUD COVER WILL HAVE A TWO FOLD EFFECT ON THE
TEMPERATURES. AFTERNOON HIGHS ARE EXPECTED TO BE MILD AND THE
OVERNIGHT LOWS WILL ONLY DROP TO NEAR 50 DEGREES WHICH IS ABOUT 10
DEGREES ABOVE NORMAL.
PRECIPITATION CHANCES END TONIGHT AS THE SHORTWAVE TROUGH EXITS
WEST CENTRAL TEXAS. WITH THE DEPARTURE OF THE SHORTWAVE AN UPPER
LEVEL ZONAL PATTERN EMERGES AND DOMINATES THE FORECAST AREA. AS
THE CLOUDS BEGIN TO CLEAR TOMORROW MORNING...THE AFTERNOON HIGHS
ARE EXPECTED TO BE NEAR 70 DEGREES AREA WIDE.
18
LONG TERM...
GFS AND EC MODELS ARE IN GOOD AGREEMENT...WITH AN UPPER SHORTWAVE
MOVING EAST ACROSS WEST CENTRAL TEXAS...WEDNESDAY NIGHT AND
THURSDAY. A WEAK COLD FRONT FRIDAY THEN MOVES THROUGH FRIDAY.
ISOLATED SHOWERS AND PERHAPS AN ISOLATED THUNDERSTORM POSSIBLE
DURING THIS PERIOD. WITH ONLY WEAK INSTABILITY HOWEVER...GFS HAS
MUCAPES OF 100 TO 300 J/KG FRIDAY AND NONE EARLIER ON THURSDAY...
AND LIMITED MID LEVEL LAPSE RATES OF 6.5 TO 7.5 C/KM...NOT
EXPECTING MUCH THUNDER. RAINFALL AMOUNTS EXPECTED TO BE LIGHT
THURSDAY AND THURSDAY NIGHT...BUT MAY SEE HEAVIER AMOUNTS AS COLD
FRONT MOVES THROUGH SOUTHERN SECTIONS FRIDAY...MAINLY CONCHO
VALLEY AND SOUTHWARD.
GFS AND EC MODELS DIFFER THIS WEEKEND. GFS BRINGS IN AN BROAD
UPPER TROUGH WHILE THE EC HAS A BROAD WEAK RIDGING. WHILE THE GFS
PRECIPITATION ALGORITHM SOME RAIN...WILL HOLD ON MENTIONING
RAINFALL CHANCES WITH MODEL DIFFERENCES AND NORMAL LOWER CONFIDENCE
IN THE LONG TERM.
04
&&
.PRELIMINARY POINT TEMPS/POPS...
ABILENE 51 70 49 73 50 / 10 5 10 5 0
SAN ANGELO 50 72 51 73 50 / 10 5 10 5 5
JUNCTION 53 70 52 75 51 / 10 5 10 5 5
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
HUBER
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
200 AM CST MON NOV 19 2012
.SHORT TERM...THROUGH WEDNESDAY NIGHT
200 AM CST MON NOV 19 2012
MAIN FORECAST CONCERNS ARE ON PRECIPITATION CHANCES TODAY AND HOW
WARM WE WILL GET ON WEDNESDAY.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED A DEEP TROUGH JUST OFF BRITISH COLUMBIA...THEN A
WEST-SOUTHWEST FLOW FROM CALIFORNIA INTO THE WESTERN GREAT LAKES
REGION. WITHIN THIS FLOW...A WEAK SHORTWAVE TROUGH STRETCHED FROM
WESTERN IOWA INTO CENTRAL KANSAS. AHEAD OF THIS SHORTWAVE TROUGH...A
PLUME OF PRECIPITABLE WATER VALUES OF 0.75 INCHES OR SO CAN BE SEEN
ON GOES DERIVED IMAGERY...STREAMING NORTH FROM OKLAHOMA INTO NORTH
CENTRAL IOWA. PROFILER AND VWP DATA SHOWED 850MB WINDS OF 30-40 KT
WITHIN THIS PLUME OF MOISTURE...HELPING TO ADVECT IT NORTHEAST
TOWARDS THE FORECAST AREA. THE COMBINATION OF THIS MOISTURE
TRANSPORT AND WEAK DPVA AHEAD OF THE SHORTWAVE TROUGH HAS BEEN
SUPPORTING A BAND OF SHOWERS JUST EAST OF I-35 IN IOWA. IN
ADDITION TO THE ADVECTION OF MOISTURE...THE WINDS AS WELL AS
CLOUDS ARE HELPING TO KEEP TEMPERATURES UP IN THE 40S AND EVEN
AROUND 50 AT SOME LOCATIONS. LAST ITEM OF NOTE WAS ANOTHER WEAK
SHORTWAVE TROUGH OVER EASTERN MONTANA. DRIER AIR PRESENT OVER THE
NORTHERN PLAINS...AS SEEN ON THE 00Z BIS AND GGW SOUNDINGS...HAS
KEPT ANY CLOUD COVER TO SCATTERED HIGH BASED ALTOSTRATUS AND
CIRRUS WITH THIS SHORTWAVE TROUGH.
TODAY AND TONIGHT...THE SHORTWAVE TROUGH JUST OFF TO OUR SOUTHWEST
IS PROGGED TO LIFT NORTHEAST AND MOVE THROUGH MUCH OF THE FORECAST
AREA BY 21Z TODAY. MEANWHILE...THAT NEXT SHORTWAVE TROUGH OVER
MONTANA LOOKS TO DROP DOWN INTO THE FORECAST AREA AFTER 06Z TONIGHT
IN THE WAKE OF THE FIRST TROUGH. MOST OF THE FOCUS IS ON THE
SHORTWAVE TROUGH TODAY AS IT HAS THE MOST MOISTURE TO WORK WITH.
PRECIPITABLE WATER FORECASTS SHOW THE AREA OF MOISTURE IN CENTRAL
IOWA SPREADING NORTHEAST THROUGH THE FORECAST AREA...THEN SLOWLY
SHIFTING EAST THIS AFTERNOON THROUGH TONIGHT AS THE SHORTWAVE TROUGH
EXITS THE FORECAST AREA. SEEING THAT THE WEAK DPVA AND ISENTROPIC
LIFT HAS BEEN ABLE TO PRODUCE THE BAND OF SHOWERS NEAR I-35 IN
IOWA...FEEL CONFIDENT THAT SHOWERS WILL AFFECT THE FORECAST AREA
TODAY. HRRR RUNS SINCE 19.01Z HAVE HAD A GOOD HANDLE ON THE SHOWERS
AND THUS THE FORECAST PRECIPITATION CHANCES ARE CLOSE TO IT. THERE
MAY NOT BE MUCH RAIN...GIVEN WEAK FORCING...BUT RAIN NONETHELESS.
BEST CHANCES ARE THIS MORNING OVER THE EASTERN TWO THIRDS OF THE
AREA. SKIES LOOK TO STAY CLOUDY THROUGH MUCH OF THE DAY TODAY...
WITH PERHAPS SOME CLEARING COMING IN WESTERN SECTIONS DURING THE
AFTERNOON AS SUBSIDENCE ALONG WITH DRIER AIR FROM THE DAKOTAS
BEGIN TO ADVECT IN. A BETTER CLEARING TREND IS EXPECTED TONIGHT...
ESPECIALLY AFTER MIDNIGHT...ONCE THAT NEXT SHORTWAVE TROUGH MOVES
IN. APPEARS TO BE SOME PRETTY STRONG SUBSIDENCE AND DRYING IN THE
WAKE OF THAT SHORTWAVE TROUGH. ALTHOUGH THERE WILL BE PLENTY OF
CLOUDS AROUND TODAY...ADVECTION AND LIMITED INSOLATION SHOULD BE
ENOUGH FOR ALL LOCATIONS TO CLIMB INTO THE 50S. WESTERN SECTIONS
COULD EVEN REACH THE UPPER 50S GIVEN THAT THEY HAVE POTENTIAL FOR
SOME SUN. COMBINATION OF CLEARING TONIGHT AND A WEAK PRESSURE
GRADIENT SHOULD ALLOW TEMPERATURES TO FALL INTO THE 30S...
ESPECIALLY IN WESTERN SECTIONS WHERE CLEARING IS MOST LIKELY TO
OCCUR.
TUESDAY THROUGH WEDNESDAY NIGHT...THE DEEP UPPER TROUGH OFF THE
BRITISH COLUMBIA IS FORECAST BY ALL MODELS TO MOVE ACROSS THE
PACIFIC NORTHWEST AND NORTHERN U.S. ROCKIES DURING THIS PERIOD...AS
A FAIRLY POTENT SHORTWAVE TROUGH...RESULTING IN THE FORMATION OF A
LOW PRESSURE SYSTEM DOWNSTREAM IN THE NORTHERN PLAINS. AS THIS
TROUGH MOVES ACROSS...STRONG UPPER RIDGING DEVELOPS DOWNSTREAM INTO
THE FORECAST AREA BY 12Z WEDNESDAY. WITH THIS RIDGING COMES A PLUME
OF DOWNSLOPED WARM AIR OFF THE ROCKIES. INITIALLY 850MB TEMPS ARE ON
THE RELATIVELY COOL SIDE ON TUESDAY...ONLY 4-6C OR SO AT 18Z...
CAUSED BY THAT SHORTWAVE DROPPING INTO THE AREA TONIGHT. STILL...
PLENTY OF SUN THANKS TO STRONG SUBSIDENCE AND DRYING IN THE WAKE OF
THE SHORTWAVE SHOULD ALLOW FOR GOOD MIXING...WITH HIGHS CLIMBING
INTO THE UPPER 40S TO MIDDLE 50S. WINDS WILL BE LIGHT TOO WITH A
SURFACE HIGH PRESSURE RIDGE CROSSING. COULD SEE A DECENT TEMPERATURE
DROP TUESDAY EVENING WITH FAVORABLE RADIATIONAL COOLING CONDITIONS
IN PLACE...ESPECIALLY ACROSS WISCONSIN WHERE THE RIDGE LINGERS
LONGEST. THE SOUTHERLY WINDS THEN PICK UP AFTER MIDNIGHT AND
ESPECIALLY FOR WEDNESDAY INTO WEDNESDAY NIGHT AS THE PRESSURE
GRADIENT TIGHTENS. 850MB TEMPS RESPOND BY WARMING TO AT LEAST 9-12C
PER MODEL CONSENSUS...OR CLOSE TO 2 STANDARD DEVIATIONS ABOVE
NORMAL. 925MB TEMPS ARE SIMILAR TO THOSE AT 850MB. SUBSIDENCE AND
DRY AIR ASSOCIATED WITH THE UPPER RIDGE WILL ALLOW FOR SUNNY
SKIES...SO CONDITIONS ARE FAVORABLE FOR MIXING. BIGGEST QUESTION
MARK IS CAN WE MIX TO 925MB. 00Z GFS/NAM SOUNDINGS SAY THE BEST WE
CAN DO IN OUR AREA IS 950MB...WHILE FARTHER WEST SAY IN SOUTH
CENTRAL AND SOUTHWEST MINNESOTA...MIXING ENDS UP BEING TO 925-900MB.
THE CAUSE FOR THE DIFFERENCE IN MIXING IS DUE TO HOW COLD WE GET
TUESDAY NIGHT. THINK THE NAM IS TOO COLD...PLUS THE WINDS PICKING UP
AFTER MIDNIGHT ESPECIALLY IN SOUTHEAST MINNESOTA MAY EVEN CAUSE
TEMPERATURES TO CLIMB. THE GFS LOOKS A LITTLE MORE REPRESENTATIVE
AND THUS IS A LITTLE WARMER THAN THE NAM FOR HIGHS. FOR NOW HAVE
LEFT THE PREVIOUS FORECAST HIGHS ALONE...THOUGH IT IS POSSIBLE THEY
NEED TO BE LOWERED. IN ANY EVENT...WEDNESDAY NIGHT LOOKS MILD
WITH THE AREA IN THE WARM SECTOR AND A PERSISTENT SOUTHERLY BREEZE
HELPING TO HOLD TEMPERATURES UP. STAYED TOWARDS THE WARM SIDE OF
GUIDANCE FOR LOWS.
.LONG TERM...THANKSGIVING THROUGH SUNDAY NIGHT
200 AM CST MON NOV 19 2012
MAIN HEADLINE HERE IS THE DRAMATIC TEMPERATURE FALL POSSIBLE
BETWEEN THANKSGIVING AND FRIDAY.
19.00Z ECMWF/CANADIAN/UKMET/GFS AND GFS ENSEMBLES ARE IN MUCH BETTER
AGREEMENT THAN YESTERDAY. ALL MODELS NOW HAVE THAT POTENT TROUGH
DIGGING INTO OUR REGION FOR THURSDAY NIGHT INTO FRIDAY...BRINGING
WITH IT A PORTION OF COLD CANADIAN AIR THAT HAS BEEN BUILDING UP IN
THE YUKON TERRITORY. THE POTENT TROUGH IS VERY PROGRESSIVE...DUE TO
NEW TROUGHING DEVELOPING OVER THE PACIFIC NORTHWEST BY THE END OF
THE WEEKEND...PUSHING UPPER RIDGING TOWARDS THE AREA. NOTE THAT THE
19.00Z GUIDANCE SUGGESTS THIS UPPER RIDGING IS FLATTER...THUS THE
WARM UP IS NOT AS INTENSE AS WHAT THE 18.12Z ECMWF SUGGESTED. PLENTY
OF TIME FOR THIS CHANGE ONE WAY OR THE OTHER OVER THE NEXT FEW
DAYS...THOUGH.
THE BIGGEST ISSUE WITH THE UPPER TROUGH ENTERING THE AREA EARLY IN
THE PERIOD IS TIMING OF THE MAIN COLD FRONT WITH IT...WITH THE
UKMET/GFS FASTER THAN THE CANADIAN/ECMWF. AT 00Z FRIDAY...THE FORMER
HAS THE FRONT THROUGH THE AREA WHILE THE LATTER HAS THE FRONT COMING
INTO WESTERN SECTIONS OF THE AREA. THIS HAS SIGNIFICANT IMPLICATIONS
ON TEMPERATURES FOR THANKSGIVING DAY...GIVEN THAT READINGS WILL
START OFF MUCH WARMER THAN THOSE ON TUESDAY NIGHT...THUS ALLOWING
FOR BETTER MIXING POTENTIAL. PLUS...925MB TEMPS MAY NOT COOL MUCH
UNTIL LATE IN THE DAY. FOR NOW HAVE STAYED CLOSE TO THE PREVIOUS
FORECAST FOR HIGHS UNTIL THE FRONTAL TIMING CAN BE IRONED OUT.
ONE OTHER ISSUE FOR THANKSGIVING DAY IS THAT THE GFS/CANADIAN
PRODUCE QPF OVER THE SOUTHEAST HALF OF THE FORECAST AREA. THIS QPF
IS RELATED TO A SUBTROPICAL SHORTWAVE EJECTING OUT OF AN UPPER LOW
CROSSING NORTHERN MEXICO ON WEDNESDAY. EVERY MODEL SUGGESTS A PLUME
OF HIGHER MOISTURE STREAMING UP INTO THE FORECAST AREA ON
THANKSGIVING...AHEAD OF THE WARM FRONT...NOTED BY 850MB DEWPOINTS
CLIMBING TO 4C OR SO. NEW 19.00Z ECMWF NOW PRODUCES QPF TOO BY
BRINGING THAT SHORTWAVE UP...THOUGH LIGHTER AND OUTSIDE FOR THE
FORECAST AREA. WITH GOOD AGREEMENT ON THE SHORTWAVE COMING UP
THROUGH THE MOISTURE STREAM...KEPT THE CONSENSUS APPROACH ADDITION
OF 20 PERCENT CHANCES FOR THE SOUTHEAST HALF ON THANKSGIVING.
AFTER THE MAIN FRONTAL PASSAGE...ATTENTION TURNS TO WINDS AND
TEMPERATURES AS COLD AIR FILTERS IN. IT APPEARS THE COLDEST AIR
WAITS UNTIL FRIDAY...ASSOCIATED WITH A SECONDARY COLD FRONTAL
PASSAGE. FOR EXAMPLE...850MB TEMPS AT 06Z FRIDAY ARE GENERALLY IN
THE RANGE OF -3C WEST TO 1C EAST. BY 18Z FRIDAY...EVERYONE IS SEEING
850MB TEMPS BETWEEN -10 AND -13C. THUS...TEMPERATURES PROBABLY ARE
NOT GOING TO RISE MUCH ABOVE MORNING LOWS...AND IF ANYTHING POSSIBLY
FALL. GOOD MIXING SETUP TOO GIVING COLD ADVECTION DURING THE DAYTIME
AND UNIDIRECTIONAL LOW LEVEL WINDS. SUSTAINED 15-20 KT WINDS LOOK
REASONABLE WITH GUSTS OF 30-35 KT AT LEAST WEST OF THE MISSISSIPPI
RIVER.
THINGS CALM DOWN FOR FRIDAY NIGHT AND THE WEEKEND AS A RIDGE OF HIGH
PRESSURE CROSSES THE AREA AND BEGINS A WARM UP.
&&
.AVIATION...
1105 PM CST SUN NOV 18 2012
AN UPPER LEVEL SHORTWAVE TROUGH WILL DRIVE NORTHEAST ACROSS THE
REGION TONIGHT. CLOUDS WERE INCREASING AND LOWERING AHEAD OF THE
SHORTWAVE...WHILE 88-D RADAR RETURNS POINTING TO SOME LIGHT SHOWERS
ADVANCING NORTHEAST FROM SOUTHWEST IA. VSBYS WERE GENERALLY P6SM
WITH THE SHOWERS...WITH ONLY T/0.01 AMOUNTS. HRRR DOING A GOOD JOB
CAPTURING THE PCPN...AND WILL REFINE TIMING AT KLSE USING IT.
ALSO...WILL ADD VCSH FOR A SHORT PERIOD AT KRST BASED ON RADAR
TRENDS AND THE HRRR. MEANWHILE...MODELS CONTINUE TO SUGGEST THE
POTENTIAL FOR A FURTHER LOWERING OF CLOUD BASES MONDAY AFTERNOON AS
MOISTURE CONTINUES TO RIDE NORTHWARD AHEAD OF THE SHORTWAVE/S SFC
COLD FRONT. MVFR CAN/T BE RULED OUT FOR A FEW HOURS...BUT CONFIDENCE
NOT HIGH ENOUGH TO INCLUDE IN THE FORECAST AT THIS TIME. THE FRONT
WILL MOVE IN MONDAY NIGHT...LIKELY PASSING KRST NEAR 04Z TUE
AND AFTER 06Z AT KLSE.
&&
.CLIMATE...
200 AM CST SUN NOV 18 2012
RECORD HIGH TEMPERATURES FOR WEDNESDAY/21ST AND THURSDAY/22ND. COOP
SITES ARE 6AM-6AM HIGHS...THUS 22ND HIGHS ARE 21.12Z TO 22.12Z. LA
CROSSE AND ROCHESTER ARE ONLY NON-COOP SITES.
FORECAST HIGH TEMPERATURES SUGGEST SOME OF THE RECORDS BELOW MAY
BE TIED OR BROKEN.
LOCATION WEDNESDAY/21ST THURSDAY/22ND
LA CROSSE WI 72/1990 59/1963
SPARTA WI 65/1990 70/1990
MEDFORD WI 59/1913 65/1990
LANCASTER WI 66/2003 66/1898
MAUSTON WI 67/2003 66/1990
ROCHESTER MN 69/1990 65/1913
AUSTIN MN 70/1990 58/1966
WINONA DAM 5A MN 60/2003 60/2001
WABASHA MN 61/1908 59/1908
CHARLES CITY IA 71/1990 62/1966
OELWEIN IA 71/1990 62/1966
DECORAH IA 71/1990 62/1908
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
200 AM CST MON NOV 19 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION.....RIECK
CLIMATE......JONES/DB/AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1105 PM CST SUN NOV 18 2012
.SHORT TERM...TONIGHT THROUGH WEDNESDAY
332 PM CST SUN NOV 18 2012
THE MAIN WEATHER CHALLENGES FOR THIS FORECAST WERE A LIGHT
SCATTERED RAIN SHOWER DAY FOR MONDAY FOLLOWED BY POSSIBLY NEAR
RECORD WARMTH ON WEDNESDAY.
GOES WATER VAPOR IMAGERY SHOWING A WEAK DARKENING SIGNAL
ASSOCIATED WITH A SHORTWAVE TROUGH OVER NRN MN SHIFTING SLOWLY
NORTHEAST. IN COMBINATION WITH WEAK ISENTROPIC LIFT THIS HAS
PROVIDED SOME 7KFT CLOUD COVER OVER WRN WI. THIS ALL AHEAD OF
SHORTWAVE RIDGING IN AN INCREASING MID-HIGHER LEVEL MOIST
SOUTHWEST FLOW WITH ROOTS TO THE TROPICS. NEXT SHORTWAVE TROUGH
HEADING TOWARD THE AREA IS CLEAR IN THE GOES WATER VAPOR TOO IN
NERN NM...WITH A TROPOPAUSE FOLD DOWN TO ABOUT 350 MB...NOT TOO
IMPRESSIVE. 18.12Z RAOB SOUNDINGS SHOWING A VERY DRY AIR MASS
BELOW 15KFT TO THE SOUTHWEST...WITH SOME SMALL INCREASES UPSTREAM
IN TOPEKA KS AND NORMAN OK. STILL...NOT A VERY MOIST AIR MASS IN
THE RETURN FLOW FROM THE GULF IN THE LOWEST LEVELS.
SHORTWAVE TROUGH OVER NERN MN WILL CONTINUE NORTHEAST..AND
ARRIVES IN THE AREA LATE TONIGHT. THICK CLOUDS MOVING IN AND
SOUTHERLY WINDS WILL KEEP OVERNIGHT LOWS ABOVE NORMAL HIGH
TEMPERATURES FOR THIS TIME OF YEAR. 18.06Z AND 18.12Z HI-RES WRF
RUNS ARE SUGGESTING THE MID-LEVEL CLOUDS WILL HANG AROUND IN THE
EVENING BEFORE SHIFTING NORTHEAST BUT OVERALL AN INCREASE IN CLOUD
IS FORECAST OVERNIGHT. SOUTHERLY FLOW CONTINUES WITH WEAK
ISENTROPIC LIFT AND ONLY 1 TO 2 UB/S UPWARD VERTICAL MOTION ALOFT
FROM 500-300MB QG DIAGNOSTICS WITH CONSENSUS 18.12Z GUIDANCE RUNS.
HI-RES WRF MODELS SUGGESTING SOME REFLECTIVITY TO BE AROUND BY
12Z MONDAY MOVING IN FROM THE SOUTH BUT STRUGGLES CONTINUE WITH
DRY LOWER LEVELS AND PRECIPITATION MAKING IT TO THE GROUND. STILL
THINK SOME VERY LIGHT SHOWERS OR SPRINKLES WILL BE AROUND FOR
MONDAY WITH CLOUDS AND MILD TEMPERATURES. FORECAST CHANGES WERE
MINOR FOR THIS WEATHER PERIOD BUT DID SLOW THE TIMING OF ONSET AND
MOVED THE WEATHER EAST MONDAY LATER AFTERNOON.
SHORTWAVE TO SHIFT EAST OVERNIGHT MONDAY NIGHT IN COMBINATION WITH
NORTHERN STREAM TROUGH...AND SUBSIDENCE KICKS IN TUESDAY THROUGH
WEDNESDAY FOR CLEAR WEATHER.
RIDGE BUILDING AND WARMING KICKS IN TUESDAY NIGHT AND WEDNESDAY
WITH A WARM FRONT AND WARM TONGUE MOVING IN OFF THE HIGH PLAINS
WEDNESDAY. THE 18.12Z NAM....ECMWF AND 18.09Z SREF MEAN 850MB
TEMPERATURES SHOWING VERY NEAR 2 STANDARD DEVIATIONS ABOVE NORMAL
OVER THE AREA FOR WEDNESDAY. THIS WOULD SUGGEST WE ARE GETTING
NEAR RECORD WARMTH. MODEL GUIDANCE CONSENSUS IS ALSO VERY DRY
THROUGH THE COLUMN SUGGESTING FULL SUN IS LIKELY. WITH THE LOW-
LEVEL PRESSURE GRADIENT IN PLACE...VERTICAL MIXING WILL BE
ENHANCED AS WELL. THE CONSENSUS 925MB TEMPERATURES ARE ABOUT 12C
BY LATE AFTERNOON...SLIGHTLY WARMER IN THE WEST. WITH TODAYS HIGHS
55-60F TODAY UNDER 7-8C AT 925MB...BELIEVE UPPER 60S TO 70F IS NOT
OUT OF THE QUESTION WITH 12C AT 925MB WEDNESDAY. HAVE AGAIN INCREASED
HIGHS TO ABOVE ALL MODEL GUIDANCE VALUES AND CLOSER TO RECORDS.
HOWEVER...RECORD HIGHS ARE QUITE WARM WEDNESDAY FROM A 1990 PRE-
FRONTAL DAY THAT WAS VERY SIMILAR TO THIS YEAR /SEE CLIMATE SECTION
BELOW/. HAVE MID-60S NOW IN THE FORECAST...COOLER IN CENTRAL WI.
MOS HIGHS HAVE BEEN IGNORED FOR WEDNESDAY.
.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY
332 PM CST SUN NOV 18 2012
THIS PERIOD WILL BE DRY IT APPEARS AND CHARACTERIZED BY A RETURN
TO NORMAL TEMPERATURES AS A COLD FRONT MOVES THROUGH LATER
THURSDAY. THIS TIMING IS IN PRETTY GOOD AGREEMENT AMONG THE LATEST
MODEL GUIDANCE. THE 18.12Z ECMWF IS NOW STRONGER WITH THIS SHORTWAVE
TROUGH AND HAS A POOL OF -15C AT 850MB MOVING SWIFTLY ACROSS THE
AREA FRIDAY. IF THIS SOLUTION VERIFIES...A COLDER AND WINDIER
BLACK FRIDAY IS IN STORE THAN IS CURRENTLY FORECAST. COLD WOULD
LAST INTO SATURDAY BEFORE LARGER SCALE RIDGING AND WARMING ENSUES
INTO NEXT WEEK. SIGNALS IN THE LONGER RANGE SUGGESTING A LONGER
WAVE TROUGH MOVING INTO THE WEST AND AN ABOVE NORMAL WARM PERIOD
INTO EARLY NEXT WEEK ACROSS THE CENTRAL U.S. /HIGHS IN THE 50S/.
&&
.AVIATION...
1105 PM CST SUN NOV 18 2012
AN UPPER LEVEL SHORTWAVE TROUGH WILL DRIVE NORTHEAST ACROSS THE
REGION TONIGHT. CLOUDS WERE INCREASING AND LOWERING AHEAD OF THE
SHORTWAVE...WHILE 88-D RADAR RETURNS POINTING TO SOME LIGHT SHOWERS
ADVANCING NORTHEAST FROM SOUTHWEST IA. VSBYS WERE GENERALLY P6SM
WITH THE SHOWERS...WITH ONLY T/0.01 AMOUNTS. HRRR DOING A GOOD JOB
CAPTURING THE PCPN...AND WILL REFINE TIMING AT KLSE USING IT.
ALSO...WILL ADD VCSH FOR A SHORT PERIOD AT KRST BASED ON RADAR
TRENDS AND THE HRRR. MEANWHILE...MODELS CONTINUE TO SUGGEST THE
POTENTIAL FOR A FURTHER LOWERING OF CLOUD BASES MONDAY AFTERNOON AS
MOISTURE CONTINUES TO RIDE NORTHWARD AHEAD OF THE SHORTWAVE/S SFC
COLD FRONT. MVFR CAN/T BE RULED OUT FOR A FEW HOURS...BUT CONFIDENCE
NOT HIGH ENOUGH TO INCLUDE IN THE FORECAST AT THIS TIME. THE FRONT
WILL MOVE IN MONDAY NIGHT...LIKELY PASSING KRST NEAR 04Z TUE
AND AFTER 06Z AT KLSE.
&&
.CLIMATE...
332 PM CST SUN NOV 18 2012
RECORD HIGH TEMPERATURES FOR WEDNESDAY/21ST AND THURSDAY/22ND. COOP
SITES ARE 6AM-6AM HIGHS...THUS 22ND HIGHS ARE 21.12Z TO 22.12Z. LA
CROSSE AND ROCHESTER ARE ONLY NON-COOP SITES.
LOCATION WEDNESDAY/21ST THURSDAY/22ND
LA CROSSE WI 72/1990 59/1963
SPARTA WI 65/1990 70/1990
MEDFORD WI 59/1913 65/1990
LANCASTER WI 66/2003 66/1898
MAUSTON WI 67/2003 66/1990
ROCHESTER MN 69/1990 65/1913
AUSTIN MN 70/1990 58/1966
WINONA DAM 5A MN 60/2003 60/2001
WABASHA MN 61/1908 59/1908
CHARLES CITY IA 71/1990 62/1966
OELWEIN IA 71/1990 62/1966
DECORAH IA 71/1990 62/1908
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
332 PM CST SUN NOV 18 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BAUMGARDT
LONG TERM....BAUMGARDT
AVIATION.....RIECK
CLIMATE......JONES/DB
AREA FORECAST DISCUSSION
NWS LINCOLN IL
559 AM CST MON NOV 19 2012
.DISCUSSION...
ISSUED 256 AM CST MON NOV 19 2012
OVERALL...NOT A LOT OF CHANGES IN THE FORECAST. MAIN ISSUES ARE
TWO PERIODS OF POTENTIAL PRECIP...AND UNSEASONABLY WARM
TEMPERATURES. PREDOMINANTLY ZONAL FLOW THROUGH THE FORECAST...WITH
A COUPLE OF WAVES ALTERING THE FLOW BRIEFLY. UPPER LOW MOVING JUST
OFF THE SERN ATLANTIC COAST...AND ANOTHER WAVE PUSHING SOME
SHOWERS OVER THE MISSISSIPPI RIVER VALLEY. FIRST ISSUE WILL BE THE
PROGRESSION OF THE SHOWERS INTO ILLINOIS TODAY. OTHER THAN
THAT...WARM TEMPS THROUGH THE FIRST HALF OF THE WEEK PUSHING THE
MAXES OVER GUIDANCE. NOT A LOT OF DISSENSION BETWEEN THE
MODELS...JUST WITH THE MOS. PUSHING FORECAST MORE TOWARDS RAW
SOLUTIONS AS A RESULT. NEXT SHOT AT SHOWERY PRECIP ON TRACK FOR
THANKSGIVING DAY.
SHORT TERM...TODAY AND TONIGHT...
SHOWERS MOVING INTO THE MISS RIVER VALLEY THIS MORNING. A BIT OF
CONFLICT IN HIGH RES MODELS AS TO WHETHER OR NOT IT WILL MAKE IT
INTO CENTRAL IL. HRRR SAYS YES...WITH A SECOND ROUND APPROACHING
FROM THE SW FOR A SECONDARY ENHANCEMENT MID MORNING. 4KM WRF IS A
BIT MORE CONSERVATIVE...NAM AND ECMWF ARE DRY. AS A RESULT...AND
AT LEAST TO COVER FOR SPRINKLES THROUGH THE MORNING WITH
REMNANTS...SLIGHT POPS DOMINATE THE WESTERN THIRD OF THE CWA. WILL
HAVE TO MONITOR CLOSELY...BUT SO FAR THE SOLUTION SEEMS PLENTY AS
THE COVERAGE OF THE SHOWERS IS REDUCING ON RADAR. SHORT LIVED
PRECIP NOT ENOUGH TO COUNTER THE WARM UP THAT CONTINUES TODAY AS
SOUTHERLY WINDS GET A BIT MORE ESTABLISHED THIS AFTERNOON. MILD
TEMPS CONTINUE INTO THE OVERNIGHT YET AGAIN.
LONG TERM...TUESDAY THROUGH SUNDAY...
HIGH PRESSURE RIDGE SLOWLY DRIFTS EASTWARD...OR AT LEAST BECOMES
FAR MORE DIFFUSE FROM THE MIDWEST TO THE SOUTHERN PLAINS...AND
THE CLOSED UPPER LOW KICKS OUT OF THE SE. THE WARMING TREND
CONTINUES THROUGH MID WEEK...BRINGING TEMPS UP A DEGREE OR SO EACH DAY.
850MB TEMPS AT 6-7C WILL HAVE THE POTENTIAL TO TRANSLATE INTO
UPPER 50S/LOWER 60S. GUIDANCE HAS NOT COMPLETELY LATCHED ONTO THE
WARMING TREND...THOUGH THE MODEL FIELDS CLEARLY SHOW THE THERMAL
RIDGE IN THE WESTERN CONUS DEEPENING AND SLOWLY CREEPING INTO THE
MIDWEST. HAVE BUMPED MAX TEMPS A FEW DEGREES AHEAD OF ALLBLEND FOR
MON- WED...AND A BIT ON THURSDAY. THURSDAY MAY BE COMPLICATED BY
AN APPROACHING STORM SYSTEM AND ASSOCIATED CLOUD COVER...BUT
SYSTEM STILL HAS A BIT OF UNCERTAINTY AS FAR AS MID AND LOW LEVEL
MOISTURE FIELDS. ALLBLEND PUSHING POPS TO CHANCE CAT.
HJS
&&
.AVIATION...
ISSUED 559 AM CST MON NOV 19 2012
PREDOMINANTLY VFR CONDITIONS EXPECTED ACROSS THE CENTRAL ILLINOIS
TERMINALS THROUGH THE 12Z TAF VALID TIME. HOWEVER...THE GRADUAL
PASSAGE OF AN UPPER LEVEL DISTURBANCE WILL CAUSE CIGS TO
THICKEN/LOWER WITH TIME. SOME OF THE MODEL GUIDANCE SUGGESTS MVFR
CIGS WILL DEVELOP BY LATE TONIGHT...BUT THIS IS NOT A UNANIMOUS
AGREEMENT. SOME VERY LIGHT RAIN/SPRINKLES ARE POSSIBLE AS THE
DISTURBANCE STARTS TO PUSH THROUGH...BUT DO NOT EXPECT MUCH IN THE
WAY OF MEASURABLE RAINFALL AT ANY ONE TERMINAL. FOR NOW...HAVE
LIMITED VCSH MENTION TO KPIA/KSPI WHERE THE POTENTIAL RAINFALL
WILL ARRIVE FIRST...WITH A DRYING TREND EXPECTED AS THE PATCHY
RAIN MOVES FURTHER EAST. SOUTHERLY WIND AOB 10 KTS ARE EXPECTED
FOR MOST OF THE PERIOD...BUT THE PASSAGE OF A SURFACE TROF LATER
TONIGHT WILL HAVE WINDS SHIFTING TO THE NORTHWEST.
BAK
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
851 AM CST MON NOV 19 2012
.UPDATE...
A QUICK REVIEW OF 12Z UA DATA AND RAP TRENDS INDICATE THE
PRECIPITATION WILL BE SHUTTING DOWN RATHER QUICKLY DURING THE
MORNING HOURS DUE TO DRY AIR AND WEAKENING FORCING.
RAP TRENDS ON THE 305K SFC DEPICT REASONABLY WELL WHAT IS
CURRENTLY GOING ON. THESE TRENDS INDICATE DECREASING PRECIP
CHANCES ACROSS THE NORTHERN CWFA WITH BETTER CHANCES OVER THE
SOUTHEAST HALF DUE TO WEAKER BUT RELATIVELY STRONGER. THE BACK
EDGE OF THE PRECIPITATION SEEMS TO BE REASONABLY TIED TO THE 10MB
CONDENSATION PRESSURE DEFICIT ON THE 305K SFC. USING THIS AND THE
OVERALL FORCING SUGGESTS MOST PRECIPITATION SHOULD END BY MID DAY
WITH PERHAPS A FEW SPRINKLES/ISOLD SHRA IN THE FAR EAST EARLY THIS
AFTERNOON.
CLOUDS WILL CONTINUE TO DECREASE AS WELL DURING THE LATE MORNING
AND AFTERNOON FROM WEST TO EAST. THIS DECREASE WILL LIKELY AFFECT
TEMPERATURES AS WELL WITH THE WESTERN THIRD OF THE CWFA
POTENTIALLY WARMER THAN FCST. ..08..
&&
.PREV DISCUSSION... /ISSUED 541 AM CST MON NOV 19 2012/
UPDATE...
RADAR TRENDS HAVE SHOWN A STEADY WEAKENING OF THE RAIN BAND AS IT
WORKS ACROSS THE WESTERN PORTIONS OF THE FORECAST AREA. HAVE
RAISED POPS FOR THE EARLY MORNING HOURS...AS THE AREAS THAT ARE
RAINING ARE ACTUALLY PRODUCING SEVERAL HUNDREDTHS OF RAINFALL.
STILL NOT MUCH...BUT NOTICEABLE. THE BACK EDGE OF THE CLOUD COVER
IS ALSO STEADILY MARCHING EAST. THE TIMING OF THIS IS
CONSIDERABLY FASTER THAN PREVIOUSLY FORECAST...AND HAVE ADJUSTED
SKY COVER IN THE FORECAST TO ACCOUNT FOR AN AFTERNOON CLEARING
TREND. LE
AVIATION...
CURRENT RAIN BAND HAS VFR CIGS AND VSBYS...AND WILL GRADUALLY WORK
ACROSS THE TERMINALS THIS MORNING. A TRAILING RAIN AREA NOW IN
MISSOURI TO MOVE NORTHEAST AND CAUSE PRECIPITATION CHANCES TO
LINGER FOR KBRL INTO THE EARLY AFTERNOON HOURS. THIS PRECIPITATION
IS AHEAD OF A COLD FRONT THAT IS EXPECTED TO MOVE ACROSS THE
TERMINALS TONIGHT...GENERALLY BETWEEN LATE EVENING AND EARLY
TUESDAY MORNING. WINDS AHEAD OF THE FRONT TO BE SOUTH...GENERALLY
BETWEEN 5 AND 10 KTS. AS THE FRONT MOVES THROUGH THEY WILL GO
LIGHT AND VARIABLE FOR A WHILE BEFORE TURNING NORTHWEST...STILL 5
TO 10 KTS. SOME MODELS IMPLYING SOME MVFR CIGS TO ACCOMPANY THE
FRONT ITSELF...BUT NO LOW CLOUD FORMATION HAS APPEARED WHERE THEY
IMPLY IT SHOULD ALREADY BE FORMING AND HAVE LEFT OUT OF FORECAST. WILL
BE WATCHING FOR THIS POTENTIAL WITH LATER FORECASTS. LE
PREV DISCUSSION... /ISSUED 303 AM CST MON NOV 19 2012/
SYNOPSIS...
A BAND OF LIGHT RAIN IS MOVING ACROSS THE FORECAST AREA THIS
MORNING...FOLLOWED BY ANOTHER MASS OF RAIN IN WESTERN MISSOURI.
ALL THIS IS BEING DRIVEN BY A SHORTWAVE MOVING ACROSS THE
MIDWEST...WITH VORT MAXES OVER WESTERN IOWA...AND ANOTHER OVER
EASTERN KANSAS. THESE ARE MOVING ACROSS A NARROW PLUME OF GULF
MOISTURE EXTENDING FROM WEST TEXAS UP INTO WESTERN IOWA AS OF THE
00Z ANALYSIS LAST NIGHT. AT THE SURFACE...THERE IS A SURFACE LOW
OVER EASTERN SOUTH DAKOTA...WITH A TROUGH AXIS/WEAK COLD FRONT
EXTENDING SOUTH ACROSS NEBRASKA AND INTO KANSAS.
SHORT TERM...
THE SHORTWAVE WILL CONTINUE TO MOVE ACROSS THE AREA
TODAY...BRINGING THE CURRENT BAND ACROSS THE FORECAST AREA...
MAINLY THIS MORNING. RADAR RETURNS ARE RELATIVELY WEAK AND CIELING
HEIGHTS HAVE REMAINED MOSTLY ABOVE 5KFT. ALSO...AS THE BAND HAS
MOVED ACROSS LOCATIONS ONLY SOME HAVE REPORTED ANY PRECIPITATION...
AND NOT MORE THAN A FEW HUNDRETHS OF AN INCH OF RAIN AT ANY ONE
LOCATION. THUS...HAVE KEPT POPS IN THE CHANCE CATEGORY FOR
THIS MORNING. AS THIS WAVE CONTINUES EAST IT MOVES OUT OF THE
PLUME OF MOISTURE...EVEN THOUGH IT WILL DRAG SOME OF IT ALONG TO
CONTINUE SOME PRECIPITATION CHANCES. IN FACT...BY THE TIME THE
WAVE GETS TO THE EASTERN CWA THIS AFTERNOON HAVE LOWERED POPS TO
SLIGHT CHANCES. BY THIS EVENING WE SHOULD BE MAINLY DRY. CLOUD
COVER IS GOING TO KEEP TEMPERATURES FROM GETTING AS WARM AS WE DID
ON SUNDAY...BUT WE WILL HAVE HAD A WARMER START AND THE CONTINUED
WARM AIR ADVECTION AHEAD OF THE COLD FRONT. THUS...HAVE HIGH TEMPS
IN THE MID TO UPPER 50S. TONIGHT THE COLD FRONT ITSELF MOVES
THROUGH...BRINGING COLDER AIR TO THE REGION. EXPECT SOME LOWER
CLOUDS TO ACCOMPANY THE FRONT...BUT THE WESTERN HALF TO CLEAR OUT
ENOUGH FOR MIN TEMPS IN THE MID 30S...BUT STAYING IN THE 40S IN
THE EAST UNDER THE CLOUD COVER. LE
LONG TERM...TUESDAY THROUGH SUNDAY...
MILD TEMPERATURES THROUGH THANKSGIVING THEN COLDER.
TUESDAY THROUGH THANKSGIVING DAY...ABOVE NORMAL TEMPERATURES AS
RIDGE ALOFT BUILDS INTO THE CENTER OF THE COUNTRY. THIS WILL BE
AHEAD OF A STRONG STORM SYSTEM THAT WILL MOVE INTO THE NORTHERN
PLAINS BY THANKSGIVING DAY. HIGHS ARE EXPECTED TO BE IN THE 60S THIS
PERIOD WITH THE POTENTIAL FOR 70 IN OUR SOUTHERN CWA ON WEDNESDAY.
ECM/GFS/GEM STARTING TO INCREASE THE POTENTIAL FOR SHOWERS ON
THANKSGIVING AHEAD OF STRONG COLD FRONT. FOR NOW WILL HAVE SMALL
POPS ACROSS THE CWA AND IF MODELS ARE CONSISTENT WITH THIS SIGNAL
THEN POPS MAY NEED TO BE RAISED.
THURSDAY NIGHT THROUGH SATURDAY NIGHT...COLDER WEATHER RETURNS AS A
DEEPENING UPPER LEVEL LOW TRACKS FROM THE NORTHERN PLAINS TO THE
NORTHERN GREAT LAKES. 850 MB TEMPS DROP TO -12C IN THE CWA FRIDAY
INTO FRIDAY NIGHT. ANY SNOW SHOWERS ASSOCIATED WITH THIS STORM SYSTEM
SHOULD REMAIN NORTH OF THE DVN CWA. HIGHS WILL BE IN THE 40S WITH
LOWS IN THE 20S THIS PERIOD.
SUNDAY INTO EARLY NEXT WEEK...TEMPERATURES MODERATE AHEAD OF A MUCH
STRONGER TROUGH AND ARCTIC COLD FRONT THAT WILL BE ARRIVING INTO THE
DVN CWA ABOUT NOVEMBER 28.
HAASE
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
919 AM CST MON NOV 19 2012
...UPDATED FORECAST FOR LOCALLY DENSE FOG THIS MORNING...
.UPDATE...
ISSUED AT 918 AM CST MON NOV 19 2012
HAVE UPDATED THE FORECAST TO INCLUDE SOME LOCALLY DENSE FOG IN
THE AREA AROUND PRATT, COLDWATER AND ASHLAND FOR A FEW HOURS THIS
MORNING. TEMPERATURE/DEWPOINT SPREADS HAVE NARROWED CLOSELY IN THAT
AREA EARLY THIS MORNING. THE FOG SHOULD BURN OFF BY AROUND 10 AM
TO 11 AM AS RUC MODEL SOUNDINGS FOR THAT AREA SHOW THE LOW LEVEL
INVERSION AND BOUNDARY LAYER SATURATION DISSIPATING FAIRLY QUICKLY
THIS MORNING.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 212 AM CST MON NOV 19 2012
THE GOING FORECAST SEEMS TO BE ON TRACK, IN LINE WITH CURRENT SHORT
TERM MODELS, AND WELL WITHIN TOLERANCE OF SURROUNDING ISC GRIDS.
TODAY WILL START OFF WITH A WEAK SURFACE TROUGH ORIENTED FROM NORTH-
NORTHEAST TO SOUTH-SOUTHWEST FROM NEAR WAKEENEY TO HUGOTON. WINDS
EAST OF THE TROUGH WILL BE SOUTH TO SOUTHWEST AT 7 TO 10 MPH THIS
MORNING, AND WEST OF THE TROUGH WILL BE FROM THE WEST TO
NORTHWEST AT SIMILAR SPEEDS. THE TROUGH SHOULD WORK EAST LATE
THIS MORNING, AND SHIFT WINDS TO THE NORTH BEHIND THE TROUGH
PASSAGE. AN EXITING SHORT WAVE ALOFT WILL BRING NORTHWEST FLOW
INITIALLY, BUT SHIFT TO MORE OF A ZONAL FLOW THIS AFTERNOON. A
FEW CIRRUS CLOUDS MAY STREAM ACROSS IN THE ZONAL FLOW, BUT ARE
EXPECTED TO BE THIN CLOUDS AND NOT HAVE MUCH INFLUENCE ON THE
SOLAR HEATING. MAXIMUM TEMPERATURES TODAY WILL BE CLOSE TO
YESTERDAY OR A BIT WARMER, RANGING FROM NEAR 70F DEGREES ALONG THE
OKLAHOMA BORDER TO THE UPPER 60S NORTH OF I-70 INTERSTATE.
TONIGHT, AN UPPER LEVEL RIDGE WILL BUILD IN FROM THE WEST, AND BRING
CLEAR SKIES TO SOUTHWESTERN KANSAS. WINDS WILL BE LIGHT AND FROM
THE NORTH. SOME COLD AIR WILL FILTER IN AT LOWER LEVELS, PRODUCING
MINIMUM TEMPERATURES IN THE LOWER 30S NORTHWEST OF A HAYS TO JOHNSON
CITY LINE, RANGING TO MINIMUMS AROUND 40F DEGREES IN THE MEDICINE LODGE
AREA. AS FOR MODEL GUIDANCE, THE GFS MOS IS WARMER, AND THE NAM
MODEL COOLER. I LEANED CLOSER TO THE COOLER NAM MODEL GUIDANCE,
AS IT HAS BEEN CLOSER TO REALITY LATELY THAN THE GFS MODEL HAS BEEN.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 351 AM CST MON NOV 19 2012
UPPER-LEVEL RIDGING WILL BE SITUATED ACROSS THE HIGH PLAINS ON
TUESDAY, WITH WEAK SURFACE LEE TROUGHING ACROSS THE NORTHERN PLAINS.
TEMPERATURES SHOULD REACH INTO THE UPPER 60S TO LOWER 70S.
BY WEDNESDAY, A WEAK SHORTWAVE TROUGH WILL BE EJECTING FROM BAJA
CALIFORNIA INTO THE TEXAS BIG BEND. A STRONGER SHORTWAVE TROUGH WILL
MOVE ONSHORE INTO THE NORTHWESTERN UNITED STATES. LEE TROUGHING WILL
INTENSITY IN RESPONSE TO MID-LEVEL SOUTHWESTERLY FLOW ACROSS THE
ROCKIES. HIGH TEMPERATURES OUGHT TO REACH INTO THE LOWER TO EVEN
MIDDLE 70S. VERY MILD TEMPERATURES CAN BE EXPECTED WEDNESDAY NIGHT
AS LOW-LEVEL MOISTURE INCREASES FROM THE GULF OF MEXICO (DEWPOINTS
IN THE LOWER TO MID 40S) AND WINDS REMAIN AT LEAST 10 KTS.
TEMPERATURES MAY NOT FALL BELOW THE LOWER 50S FROM DODGE CITY
EASTWARD TO MEDICINE LODGE.
BY THURSDAY, THE SOUTHERN STREAM SYSTEM WILL BE MOVING ACROSS THE
SOUTHERN PLAINS WHILE THE STRONGER NORTHERN STREAM SHORTWAVE TROUGH
PROGRESSES ACROSS THE NORTHERN PLAINS. A COLD FRONT ASSOCIATED WITH
THE NORTHERN SYSTEM WILL BE PASSING THROUGH SOUTHWEST KANSAS DURING
THE LATE MORNING AND EARLY AFTERNOON. CONTINUED RETURN FLOW FROM
THE GULF OF MEXICO AHEAD OF THE FRONT WILL LEAD TO DEWPOINTS IN THE
LOWER 50S IN SOUTH CENTRAL KANSAS BY AFTERNOON. SURFACE BASED CAPE
VALUES MAY APPROACH 500 J/KG BY AFTERNOON GIVEN HIGH TEMPERATURES IN
THE LOWER 70S. A FEW NON-SEVERE THUNDERSTORMS MAY DEVELOP. THE EXACT
PLACEMENT OF THE STORMS WILL DEPEND ON THE SPEED OF THE FRONT. THE
BEST CHANCE OF STORMS WILL BE FROM MEDICINE LODGE EASTWARD.
TEMPERATURES WILL BE FAIRLY MILD EVEN BEHIND THE FRONT AS THE MUCH
COOLER AIR WILL BE TRAILING WELL BEHIND THE WIND SHIFT.
COOLER AIR WILL MOVE INTO WESTERN KANSAS BY THURSDAY NIGHT AND
FRIDAY BEHIND THE FRONT. TEMPERATURES WILL LIKELY DROP INTO THE
40S BY MIDNIGHT, WHICH WOULD PRECLUDE DODGE CITY FROM HAVING
A RECORD HIGH MINIMUM TEMPERATURE FOR THURSDAY THE 22ND. THE RECORD
VALUE IS 46 DEGREES SET IN 1885. HIGHS FRIDAY WILL BE COOLER IN THE
MID TO UPPER 50S. HIGHS SHOULD RECOVER INTO THE 60S BY SATURDAY AS
LEE TROUGHING DEVELOPS ACROSS THE HIGH PLAINS IN RESPONSE TO WESTERLY
FLOW ACROSS THE ROCKIES.
BIG DIFFERENCES START TO APPEAR IN THE MODELS BY SUNDAY NOVEMBER
25TH INTO THE 27TH. THE ECMWF AND GEM DEVELOP AN UPPER-LEVEL RIDGE
TO THE WEST OF ALASKA AND A TROUGH FROM SOUTHWESTERN CANADA INTO THE
NORTHWESTERN UNITED STATES. THE AMPLITUDE OF THIS RIDGE-TROUGH
COMBINATION IS THE KEY TO THE FORECAST. MORE AMPLIFICATION WOULD MEAN
THAT ARCTIC HIGH PRESSURE WOULD SLIDE SOUTHEASTWARD INTO THE
NORTHERN AND CENTRAL PLAINS BY THE 26TH OR 27TH. IF THE PATTERN IS
LESS AMPLIFIED, THEN TEMPERATURES WOULD STAY CLOSER TO CLIMATOLOGY.
THE ECMWF HAS BEEN OSCILLATING BACK AND FORTH BETWEEN A MORE
AMPLIFIED AND LESS AMPLIFIED PATTERN, SO CONFIDENCE IN THE ARRIVAL
OF ARCTIC AIR AND PRECIPITATION CHANCES ARE VERY LOW.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 554 AM CST MON NOV 19 2012
A WEAK COLD FRONT WAS PASSING ACROSS SOUTHWEST KANSAS THIS MORNING.
WINDS WILL GRADUALLY SHIFT FROM THE WEST TO THE NORTH THROUGH 00Z,
WITH SPEEDS 10 KTS OR LESS. IN THE ABSENCE OF LOW LEVEL MOISTURE, VFR
CONDITIONS WILL PERSIST.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 69 36 68 40 / 0 0 0 0
GCK 69 33 68 38 / 0 0 0 0
EHA 68 35 68 38 / 0 0 0 0
LBL 69 32 69 39 / 0 0 0 0
HYS 68 32 69 41 / 0 0 0 0
P28 69 41 72 42 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GERARD
SHORT TERM...BURKE
LONG TERM...FINCH
AVIATION...FINCH
AREA FORECAST DISCUSSION
NWS GOODLAND KS
413 AM MST MON NOV 19 2012
.SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 225 AM MST MON NOV 19 2012
LATEST WV IMAGERY AND RUC H5 ANALYSIS SHOW WESTERLY ZONAL FLOW IN
PLACE ACROSS THE US...WITH SEVERAL LOW AMPLITUDE SHORTWAVE TROUGHS
EMBEDDED WITHIN MEAN FLOW. NEAREST SHORTWAVE TROUGH CURRENTLY
EXTENDS ACROSS EASTERN KS...WITH SUBSIDENCE IN PLACE BEHIND THIS
FEATURE OVER WESTERN KS. A SURFACE TROUGH AXIS CURRENTLY EXTENDS FROM
THE DAKOTAS AND ACROSS WESTERN KS...JUST EAST OF THE CWA BORDER.
OVERALL PATTERN WILL REMAIN QUIET THROUGH THE SHORT TERM...WITH MAIN
STORM TRACK WELL NORTH OF THE CWA AND WEAK SOUTHERN TRACK FAVORING
AREAS SOUTH AND EAST OF OUR CWA. PROGRESSIVE ZONAL PATTERN
TRANSITIONING TO SHORTWAVE RIDGING BY TUE...AND A RETURN TO W-SW FLOW
BY WED NIGHT AS THIS RIDGE SHIFTS EAST AND A SHORT WAVE TROUGH MOVES
WITHIN THE VICINITY OF THE CWA. THERE IS GOOD LARGE SCALE ASCENT
ACROSS CENTRAL KS WITH THIS FEATURE...CLOSE TO OUR EASTERN CWA BORDER.
HOWEVER...MOISTURE PROFILES ARE VERY DRY ESPECIALLY THROUGH ABOUT
600MB. I DECIDED TO KEEP FORECAST DRY FOR NOW IN OUR EASTERN CWA
WITH A FEW SPRINKLES POSSIBLE AT MOST.
UNSEASONABLY WARM TEMPERATURES IN THE UPPER 60S/LOW 70S ARE EXPECTED
THE NEXT THREE DAYS...WITH THE WARMEST ON WED AS LEE TROUGH
STRENGTHENS ALONG KS/CO BORDER. WITH INCREASED AFTERNOON MIXING...WE
SHOULD SEE VERY LOW RH VALUES WED AFTERNOON. CURRENT TROUGH POSITION
KEEPS THE STRONGEST WINDS OVER THE EASTERN CWA WHERE HIGHER RH
VALUES SHOULD BE...SO IT STILL LOOKS LIKE WE WONT NEED A RFW. THIS
WILL PROBABLY NEED TO BE WATCHED SINCE IT COULD BE CLOSE.
.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 225 AM MST MON NOV 19 2012
THURSDAY THROUGH SUNDAY...NORTHERN STREAM SYSTEM WILL PUSH A COLD
FRONT THROUGH EARLY ON THANKSGIVING DAY. WINDS MAY NEED TO BE A
LITTLE STRONGER THAT WHAT THE CRH_INIT GAVE ME ON THURSDAY BUT
APPEAR IN THE BALL PARK. THIS WILL BE SOMETHING THAT UPCOMING SHIFTS
WILL NEED TO WATCH. THERE WILL BE COME COOL DOWN ON THURSDAY WITH
THE COOLEST TEMPERATURES TO ARRIVE ON FRIDAY. AFTER THAT...
TEMPERATURES WILL MODERATE UNTIL LATE SUNDAY WHEN THE NEXT COLD
FRONT WILL ARRIVE. MAIN STORM TRACK/LIFT/MOISTURE REMAIN WELL NORTH
OF THE AREA SO THE DRY FORECAST LOOKS FINE AS DOES ALL THE INIT
GRIDS THAT I WAS GIVEN.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 413 AM MST MON NOV 19 2012
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD WITH ONLY PASSING
HIGH CLOUDS. WINDS WILL SHIFT FROM THE WEST TO THE NORTHWEST AS A
SURFACE TROUGH SHIFTS EAST...REMAINING BELOW 12KT THROUGH THE
PERIOD. WINDS WILL BECOME LIGHT AND VARIABLE AROUND SUNSET AS
DAYTIME MIXING ENDS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...BULLER
AVIATION...DR
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
822 AM EST MON NOV 19 2012
.SYNOPSIS...
ABOVE NORMAL TEMPERATURES ARE THE THEME THIS HOLIDAY WORK WEEK.
WEATHER WILL NOT BE OBSTACLE FOR THOSE TRAVELING BEFORE...DUE TO THE
ONLY SYSTEM THROUGH THANKSGIVING BEING ONE WHICH WILL PRODUCE
SPRINKLES AT BEST TUESDAY INTO EARLY WEDNESDAY. A STRONG FRONT
CROSSES FRIDAY NIGHT INTO SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AREA OF STRATOCU EAST OF THE MOUNTAINS IS SLOWLY CREEPING INTO THE DUJ
VICINITY AND IT HAS REACHED GARRETT COUNTY. UPDATED SKY GRIDS TO
REFLECT THESE TRENDS AND ALLOW THEM TO BURN OFF AROUND 15Z BASED
ON LLVL RH PROGS FROM THE HRRR AND NAM12. CIRRUS ADVANCING IN FROM
THE WEST WILL HINDER SUNSHINE A LITTLE...BUT WITH H8 TEMPS 1C
WARMER THAN YDY...STILL FEEL CONFIDENT THAT MAXT WILL MIRROR
SUNDAY`S VALUES.
TWEAKED HOURLY TEMPS TONIGHT TO REFLECT FASTER DROP OFF AFTER
SUNSET.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
THE MAIN FEATURE OF THE SHORT TERM PERIOD WILL BE THE AMPLIFIED
FLOW ALOFT AS THE AFOREMENTIONED SHORTWAVE TROUGH DEEPENS WITH
PROGRESSION ACROSS THE GREAT LAKES. THAT DISTURBANCE IS NOT
PROGGED TO TAP A DEEP MOISTURE SOURCE AND MEASURABLE PRECIPITATION
CHANCES ARE SMALL WITH ITS CROSSING LATER ON TUESDAY AND EARLY WEDNESDAY.
CURRENT EXPECTATIONS ARE THAT SUFFICIENT MID LEVEL MOISTURE WILL
ACCOMPANY THE SYSTEM FOR SOME SPRINKLES TO MAR THE LATE AFTN AND
AFTER DARK WEATHER PICTURE. HAVE INTRODUCED A SLIGHT SHOWER CHANCE
FOR THAT TIME PERIOD...BUT AGAIN...THINK DRIER AIR IN THE LOW
LEVELS WL INHIBIT MEASURABLE RAIN.
THEREAFTER...THE MODEL FORECAST IS FOR SHORTWAVE...BUT STILL
FAIRLY AMPLIFIED...RIDGING TO BUILD FOR WEDNESDAY AND THURSDAY.
DRY...AND WARMER WEATHER IS THUS FORECAST FOR THE HOLIDAY...WITH
TEMPS APPROXIMATELY 10 DEGREES ABOVE THE AVERAGES.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
THE GFS AND ECMWF MODEL FORECAST IS OF ANOTHER DEEP TROUGH
DIGGING ACROSS THE GREAT LAKES BY LATE WEEK. HENCE...THE POST-
THANKSGIVING PROGNOSIS IS OF INCREASED PRECIP CHANCES AND MORE
SEASONABLE TEMPERATURES.
&&
.AVIATION /13Z MONDAY THROUGH FRIDAY/...
MVFR/IFR VIS RESTRICTIONS WILL LIFT BY 14Z OWING TO VFR WEATHER.
MID AND HIGH CLOUDS WILL BE THE THEME TODAY WITH LIGHT WINDS. DUJ
COULD SEE A PERIOD OF BKN025 THROUGH 15Z AS STRATOCU TRIES TO
ADVECT IN FROM THE EAST.
.OUTLOOK.../TUESDAY THROUGH FRIDAY/...
PREVALENT VFR WITH ONLY MORNING FOG POSING POTENTIAL RESTRICTIONS.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
SYNOPSIS...98
NEAR TERM...98
SHORT TERM...15
AVIATION...98/34
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
525 AM CST MON NOV 19 2012
.SHORT TERM...
ISSUED AT 314 AM CST MON NOV 19 2012
(TODAY)
MAIN CONCERN TODAY WILL BE PRECIPITATION CHANCES. THIN BAND OF
-SHRA EXTENDING FROM SERN IA INTO CNTRL MO HAS BEEN SHOWING SOME
DECREASE IN INTENSITY IN THE LAST HALF HOUR. SURFACE OBS HAS SHOWN
NO MORE THAN A BRIEF PERIOD OF TRACE -RA WITH CEILINGS REMAIN ABOVE
6000FT AGL. THIS LINE IS BEING FORCED BY A THIN AREA OF LOW LEVEL
MOISTURE CONVERGENCE UNDER A SUBTLE SHORTWAVE TROUGH. THE RAP IS
SHOWING THIS FORCING WEAKENING THE NEXT FEW HOURS AS IT MOVES
NORTHEAST...SO WILL SHOW SCT POPS DIMINISHING TO ISOLD OVER NERN
MO/W CNTRL IL BETWEEN 12-15Z. A MORE SUBSTANTIAL AREA OF -RA IS
CURRENTLY ENTERING SWRN MO AHEAD OF SHORTWAVE NOW OVER THE CENTRAL
PLAINS. RAP/GFS/WRF MODELS ARE SHOWING THIS WAVE DAMPENING OUT
TODAY AS A STRONGER SHORTWAVE BEGINS TO DIG SOUTHEASTWARD OUT OF
THE NORTHERN PLAINS. NET EFFECT WILL BE THAT LOW-MID LEVEL FORCING
FOR THIS SECOND AREA OF RAIN WILL DIMINISH THROUGH THE DAY AS IT
MOVES NORTHEAST INTO THE CWA. TIME CROSS SECTIONS FROM THE VARIOUS
MODELS ARE SHOWING A NOTABLE LAYER OF DRY AIR REMAINING AT AND
BELOW 850MB OVER THE SOUTHERN AND EASTERN PART OF THE CWA. THE
DIMINISHING FORCING AND DRY AIR CALL FOR MAINLY CHANCE POPS OVER
CNTRL/NERN MO AND W CNTRL IL WITH JUST SLIGHT CHANCES ELSEWHERE.
EXPECT MOSTLY CLOUDY/CLOUDY SKIES OVER MOST OF THE CWA TODAY...SO
WILL GO WITH A BLEND OR LEAN TOWARD THE COOLER NAM MOS TO
TEMPERATURES TODAY.
BRITT
&&
.LONG TERM...
ISSUED AT 314 AM CST MON NOV 19 2012
(TONIGHT THROUGH SUNDAY)
A SHORTWAVE WILL DROP SEWD THROUGH THE REGION TGT AND TUE SENDING A
WEAK COLD FRONT THROUGH OUR FORECAST AREA LATE TGT AND TUE MRNG.
ALTHOUGH MOST OF THE PRECIPITATION WILL SHIFT E OF THE AREA BY THIS
EVNG...IT APPEARS THAT THERE MAY STILL BE SOME SPRINKLES ACROSS
MAINLY SERN MO AND IL WITH WEAK LOW LEVEL WAA AHEAD OF THE FRONT
AND LINGERING LOW-MID LEVEL MOISTURE. SHOULD SEE GRADUAL CLEARING
FROM NW TO SE LATE TGT AND TUE AS THE LOW LEVEL MOISTURE GETS
SHUNTED TO THE SE WITH WEAK CAA ON TUE BEHIND THE COLD FRONT/850
MB TROUGH. TEMPERATURES WILL STILL BE ABOVE NORMAL ON TUE. COOLER
LOW TEMPERATURES CAN BE EXPECTED TUE NGT DUE TO A CLEAR SKY AND
LIGHT SFC WIND WITH A RELATIVELY WEAK SFC RIDGE OVER OUR AREA. AN
UPPER LEVEL RIDGE OVER MO...ALONG WITH FULL SUNSHINE AND SFC WINDS
BECOMING SLY WILL LEAD TO UNSEASONABLY WARM CONDITIONS FOR NERN
AND CNTRL MO ON WED. THESE WARM CONDITIONS WILL CONTINUE WED NGT
AND THANKSGIVING DAY DUE TO INCREASING S-SWLY LOW LEVEL WINDS.
ALTHOUGH THE ECMWF AND GFS MODELS STILL HAVE DIFFERENCES FOR THU
AND FRI THERE SOLUTIONS HAVE BECOME MORE SIMILAR THAN THEY WERE
THE PAST COUPLE OF DAYS. IT APPEARS THAT THE GFS HAS SOME FEEDBACK
PROBLEMS WED NGT AND THU AND IS LIKELY BRINGING PRECIPITATION
INTO OUR AREA A LITTLE TOO EARLY ON THU. PREFER THE ECMWF MODEL
WHICH HAS MOST OF THE PRECIPITATION THU NGT AS AN UPPER LEVEL LOW
MOVES SEWD THROUGH THE NRN PLAINS SENDING A STRONG COLD FRONT
SEWD THROUGH OUR AREA THU NGT. THE GFS IS NOW COLDER THAN THE
ECMWF MODEL THU NGT INTO FRI MRNG AND BRINGS THE ZERO DEGREE C
850 MB ISOTHERM SEWD TO STL BY 12Z FRI. THE ECMWF MODEL THOUGH IS
A LITTLE SLOWER AND DEEPER WITH THE UPPER LEVEL LOW MOVING THROUGH
THE NRN PORTION OF THE GREAT LAKES REGION ON FRI AND BRINGS
COLDER AIR INTO OUR REGION FRI AFTN THAN THE GFS. WILL TREND
COLDER WITH TEMPERATURES FRI AND FRI NGT ALTHOUGH NOT AS COLD AS
THE ECMWF MODEL WOULD IMPLY. A WARMING TREND WILL BEGIN ON SAT OR
SAT NGT ALTHOUGH WILL TRY TO FOLLOW THE SLOWER WARMING OF THE
ECMWF MODEL. NEXT CHANCE OF PRECIPITATION SHOULD HOLD OFF TIL SUN
NGT AS A STORM SYSTEM TAKES SHAPE OVER THE SRN PLAINS.
GKS
&&
.AVIATION...
ISSUED AT 524 AM CST MON NOV 19 2012
AREA OF RAIN OVER MO WILL CONTINUE TO MOVE NORTHEAST THE NEXT FEW
HOURS...BUT IS EXPECTED TO GRADUALLY DECREASE IN AREAL COVERAGE.
THERE ARE A FEW LOCATIONS WITH MVFR CIGS WITHIN THE AREA OF RAIN
OVER SWRN MO...BUT MOST LOCATIONS ARE REPORTING VFR SO WILL GO
WITH A FEW HOURS OF VFR -RA AT KCOU AND KUIN THIS MORNING. THE
AREAL EXTENT OF THE RAIN IS EXPECTED TO DIMINISH ENOUGH TO NOT
INCLUDE IN THE STL METRO TAF SITES. MID LEVEL CIGS ARE EXPECTED TO
SLOWLY FALL DURING THE DAY...BUT THE CLEARING LINE WILL MOVE INTO
KCOU OVERNIGHT AND AT KUIN AND STL METRO TAF SITES AFTER 12Z
TUESDAY. THERE MAY BE AREAS OF FOG DEVELOP AFTER 09Z TONIGHT AS
WINDS BECOME LIGHT AHEAD OF AN APPROACHING COLD FRONT.
SPECIFICS FOR KSTL...WHILE THERE IS A SLIGHT CHANCE FOR THE -RA
OVER CENTRAL MO TO MAKE IT INTO THE TERMINAL LATER THIS MORNING/
AFTERNOON...I DO NOT THINK THE CHANCE IS HIGH ENOUGH TO INCLUDE IN
THE TAF AT THIS POINT. OTHERWISE...EXPECT MAINLY DRY AND VFR
CONDITIONS THROUGH THE PERIOD.
BRITT
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
800 AM EST MON NOV 19 2012
.SYNOPSIS...
A STRONG RIDGE OF HIGH PRESSURE OVER THE EASTERN UNITED STATES WILL
KEEP THE REGION FAIR AND DRY FOR MOST OF THIS WEEK. IN GENERAL...
SUNNY DAYS AND COOL NIGHTS ARE EXPECTED WITH SOME PATCHY FOG. MUCH
COLDER WEATHER IS EXPECTED BY NEXT WEEKEND AS A POOL OF COLD
CANADIAN AIR SPILLS ACROSS THE GREAT LAKES AND ACROSS THE
NORTHEASTERN UNITED STATES.
&&
.NEAR TERM /UNTIL 7 PM THIS EVENING/...
UPDATE DONE TO COVER EXPANDING AREA OF LOWER CLDS. STILL EXPECT
THESE CLDS TO BREAK UP BY LATE MORNING.
EARLIER DISCUSSION BELOW.
LOW CLOUDS HAVE EXPANDED TO COVER MOST OF THE LAUREL HIGHLANDS AND
PORTIONS OF THE SOUTH CENTRAL MOUNTAINS THIS MORNING. PATCHY LOW
CLOUDS HAVE ALSO PROPOGATED INTO PARTS OF THE CENTRAL AND NORTHERN
MOUNTAINS AS WELL. THE EASTERLY FLOW AROUND THE CANADIAN MARITIME
STRONG SFC RIDGE CENTER AND LOW PRESSURE ORGANIZING ALONG THE
SOUTHEAST ATLANTIC COAST IS SHUNTING ENOUGH LOW LEVEL MOISTURE
WESTWARD AND UP AGAINST THE HIGHER TERRAIN OF SOUTH CENTRAL AND
CENTRAL PA IN THE PRESENCE OF WEAK VERTICAL MIXING TO PRODUCE THE
LOW CLOUDS. TEMPS UNDER THE STRATUS MODERATE TO THE LOWER TO
MIDDLE 30S...WHILE AREAS AWAY FROM THE STRATUS ARE IN THE UPPER
20S. PATCHY FOG IS ALSO PREVALENT IN THE CLEAR AREAS...WITH VSBYS
BETWEEN 3 AND 5 MILES THIS MORNING.
STRATO CU CLOUDS SHOULD PERSIST ACROSS THE CENT MTNS AND LAURELS
THROUGH LATE MORNING THE EASTERLY UPSLOPE FLOW OF LLVL MARINE AIR
CONTINUES. EARLY MORNING FOG WILL DECREASE BY MID MORNING...WHILE
THE STRATUS LARGELY DISSIPATES BY LATE MORNING. PARTLY TO MOSTLY
SUNNY SKIES WILL DEVELOP BY THE LATE MORNING NEAR AND TO THE EAST
OF A LINE FROM KIPT TO KSEG AND KMDT. HOWEVER...NAM12 OUTLIER
SOLUTION SHOWS STRATUS PERSISTING OVER THE LOWER SUSQ THROUGH THIS
AFTERNOON...WHILE LCL 3KM HRRR SHOWS DISSIPATING AFT 15Z. TEMPS
WILL HAVE TO BE WATCHED CLOSELY AS MORE EXPANSIVE AND PERSISTENT
LOW CLOUDS COULD HOLD DOWN MAXES ACROSS CENTRAL AND SOUTHWEST
PORTIONS OF CENTRAL PA.
&&
.SHORT TERM /7 PM THIS EVENING THROUGH 6 PM TUESDAY/...
EXPECT MORE OF THE SAME TONIGHT INTO TUESDAY MORNING WITH AT LEAST
A COMPONENT OF RETURN/UPSLOPE FLOW ACTING TO PRODUCE AREAS OF LOW
CLOUDS WITH TIES TO THE LAUREL HIGHLANDS AND SOUTH CENTRAL
MOUNTAINS. SFC RIDGE AXIS REMAINS ANCHORED OVER EASTERN THIRD OF
PENNSYLVANIA TONIGHT AND TUESDAY...AND IT APPEARS THE EASTERLY
ATLANTIC FETCH WILL BECOME MORE NE TO SW ORIENTED BY 12Z TUE...
SO EXTENT OF STRATUS IS EXPECTED TO BE FAR LESS ON TUESDAY MORNING
THAN THIS MORNING...BUT WITH THE TYPICAL RIVER VALLEY FOG THAT
ACCOMPANIES STABLE STRATIFICATION OVER CENTRAL AND EASTERN PA.
MINS TONIGHT SHOULD RANGE FROM THE MID TO UPPER 20S ACROSS THE
NORTH TO THE LOWER 30S OVER THE SOUTHEAST. GENERALLY STAYED A FEW
TICKS ABOVE MOS...WHICH MAY BE UNDERDOING THE EXTENT OF FOG AND
LOW CLOUDS EARLY TUESDAY MORNING. HIGHS SHOULD MODERATE TO THE 50S
EVERYWHERE TUESDAY AFTERNOON.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
EXPECT A DIGGING TROUGH TO MOVE THROUGH EARLY WEDNESDAY. THIS
WILL BRING SOME SLIGHT CLOUDINESS AND THE RETURN FLOW OF MOISTURE
AROUND THE RIDGE MAY ADVECT ENOUGH MOISTURE NORTHWARD UP THE SPINE
OF THE APPALACHIANS TO PRODUCE A LIGHT SHOWER OVER PARTS OF THE
REGION TUESDAY NIGHT. HOWEVER ANY DOWNSLOPING SHOULD REDUCE THIS
MOISTURE AND ANY PRECIPITATION REMAINS A LOW PROBABILITY. HAVE
CONTINUED TO REDUCE POPS ACCORDINGLY. EXPECT MILD AND DRY WEATHER
WITH WARMER THAN NORMAL TEMPERATURES THROUGH THE WORK WEEK...WITH
MAX TEMPERATURES 5 TO 10 DEGREES WARMER THAN NORMAL.
THE NEXT CHANCE FOR MEASURABLE PRECIPITATION WILL BE LATE THIS
COMING WEEK AS A DEEP TROUGH MOVES IN FROM THE NORTHWEST. THE
MODELS CONTINUE TO BRING DEEP COLD AIR IN BEHIND THE FRONT...WITH
-7C 850MB TEMPS POSSIBLE NEXT SATURDAY NIGHT. EXPECT TEMPERATURES
NEXT WEEKEND TO BE BELOW NORMAL...WITH RAIN SHOWERS POSSIBLE OUT
AHEAD OF THE FRONT...FOLLOWED BY A RIBBON OF MIXED
PRECIPITATION...AND SNOW SHOWERS BEHIND. THERE IS TO MUCH
VARIABILITY TO GIVE A GOOD QUANTIFICATION OF SNOW AMOUNTS.
HOWEVER...CURRENTLY ANY ACCUMULATIONS SEEM TO BE LIGHT. THE EC
CONTINUES TO SLOWS THE SYSTEM DOWN...ABOUT 12 HRS SLOWER THAN THE
GFS. HOWEVER BOTH MODELS HAVE A SIMILAR ORIENTATION..THOUGH THE EC
HAS A DEEPER LOW THAT IS FURTHER SOUTH.
&&
.AVIATION /13Z MONDAY THROUGH FRIDAY/...
ADJUSTED 12Z TAFS FOR EXPANDING AREA OF LOWER CLDS. STILL
EXPECT THESE CLDS TO BREAK UP BY LATE MORNING.
OTHERWISE...HIGH PRESSURE ACROSS EASTERN CANADA AND THE NEW
ENGLAND STATES WILL REMAIN NEARLY STATIONY FOR THE NEXT FEW
DAYS...BRINGING MAINLY CLEAR SKIES TO THE AREA.
OUTLOOK...
WED...PATCHY AM VALLEY FOG POSSIBLE ACROSS THE ALLEGHENIES.
THU-FRI...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DEVOIR
NEAR TERM...DANGELO/MARTIN
SHORT TERM...DEVOIR/LAMBERT
LONG TERM...DEVOIR/CERU
AVIATION...FITZGERALD/MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
647 AM EST MON NOV 19 2012
.SYNOPSIS...
A STRONG RIDGE OF HIGH PRESSURE OVER THE EASTERN UNITED STATES WILL
KEEP THE REGION FAIR AND DRY FOR MOST OF THIS WEEK. IN GENERAL...
SUNNY DAYS AND COOL NIGHTS ARE EXPECTED WITH SOME PATCHY FOG. MUCH
COLDER WEATHER IS EXPECTED BY NEXT WEEKEND AS A POOL OF COLD
CANADIAN AIR SPILLS ACROSS THE GREAT LAKES AND ACROSS THE
NORTHEASTERN UNITED STATES.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATE DONE TO COVER EXPANDING AREA OF LOWER CLDS. STILL EXPECT
THESE CLDS TO BREAK UP BY LATE MORNING.
EARLIER DISCUSSION BELOW.
LOW CLOUDS HAVE EXPANDED TO COVER MOST OF THE LAUREL HIGHLANDS AND
PORTIONS OF THE SOUTH CENTRAL MOUNTAINS THIS MORNING. PATCHY LOW
CLOUDS HAVE ALSO PROPOGATED INTO PARTS OF THE CENTRAL AND NORTHERN
MOUNTAINS AS WELL. THE EASTERLY FLOW AROUND THE CANADIAN MARITIME
STRONG SFC RIDGE CENTER AND LOW PRESSURE ORGANIZING ALONG THE
SOUTHEAST ATLANTIC COAST IS SHUNTING ENOUGH LOW LEVEL MOISTURE
WESTWARD AND UP AGAINST THE HIGHER TERRAIN OF SOUTH CENTRAL AND
CENTRAL PA IN THE PRESENCE OF WEAK VERTICAL MIXING TO PRODUCE THE
LOW CLOUDS. TEMPS UNDER THE STRATUS MODERATE TO THE LOWER TO
MIDDLE 30S...WHILE AREAS AWAY FROM THE STRATUS ARE IN THE UPPER
20S. PATCHY FOG IS ALSO PREVALENT IN THE CLEAR AREAS...WITH VSBYS
BETWEEN 3 AND 5 MILES THIS MORNING.
STRATO CU CLOUDS SHOULD PERSIST ACROSS THE CENT MTNS AND LAURELS
THROUGH LATE MORNING THE EASTERLY UPSLOPE FLOW OF LLVL MARINE AIR
CONTINUES. EARLY MORNING FOG WILL DECREASE BY MID MORNING...WHILE
THE STRATUS LARGELY DISSIPATES BY LATE MORNING. PARTLY TO MOSTLY
SUNNY SKIES WILL DEVELOP BY THE LATE MORNING NEAR AND TO THE EAST
OF A LINE FROM KIPT TO KSEG AND KMDT. HOWEVER...NAM12 OUTLIER
SOLUTION SHOWS STRATUS PERSISTING OVER THE LOWER SUSQ THROUGH THIS
AFTERNOON...WHILE LCL 3KM HRRR SHOWS DISSIPATING AFT 15Z. TEMPS
WILL HAVE TO BE WATCHED CLOSELY AS MORE EXPANSIVE AND PERSISTENT
LOW CLOUDS COULD HOLD DOWN MAXES ACROSS CENTRAL AND SOUTHWEST
PORTIONS OF CENTRAL PA.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
EXPECT MORE OF THE SAME TONIGHT INTO TUESDAY MORNING WITH AT LEAST
A COMPONENT OF RETURN/UPSLOPE FLOW ACTING TO PRODUCE AREAS OF LOW
CLOUDS WITH TIES TO THE LAUREL HIGHLANDS AND SOUTH CENTRAL
MOUNTAINS. SFC RIDGE AXIS REMAINS ANCHORED OVER EASTERN THIRD OF
PENNSYLVANIA TONIGHT AND TUESDAY...AND IT APPEARS THE EASTERLY
ATLANTIC FETCH WILL BECOME MORE NE TO SW ORIENTED BY 12Z TUE...
SO EXTENT OF STRATUS IS EXPECTED TO BE FAR LESS ON TUESDAY MORNING
THAN THIS MORNING...BUT WITH THE TYPICAL RIVER VALLEY FOG THAT
ACCOMPANIES STABLE STRATIFICATION OVER CENTRAL AND EASTERN PA.
MINS TONIGHT SHOULD RANGE FROM THE MID TO UPPER 20S ACROSS THE
NORTH TO THE LOWER 30S OVER THE SOUTHEAST. GENERALLY STAYED A FEW
TICKS ABOVE MOS...WHICH MAY BE UNDERDOING THE EXTENT OF FOG AND
LOW CLOUDS EARLY TUESDAY MORNING. HIGHS SHOULD MODERATE TO THE 50S
EVERYWHERE TUESDAY AFTERNOON.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
EXPECT A DIGGING TROUGH TO MOVE THROUGH EARLY WEDNESDAY. THIS
WILL BRING SOME SLIGHT CLOUDINESS AND THE RETURN FLOW OF MOISTURE
AROUND THE RIDGE MAY ADVECT ENOUGH MOISTURE NORTHWARD UP THE SPINE
OF THE APPALACHIANS TO PRODUCE A LIGHT SHOWER OVER PARTS OF THE
REGION TUESDAY NIGHT. HOWEVER ANY DOWNSLOPING SHOULD REDUCE THIS
MOISTURE AND ANY PRECIPITATION REMAINS A LOW PROBABILITY. HAVE
CONTINUED TO REDUCE POPS ACCORDINGLY. EXPECT MILD AND DRY WEATHER
WITH WARMER THAN NORMAL TEMPERATURES THROUGH THE WORK WEEK...WITH
MAX TEMPERATURES 5 TO 10 DEGREES WARMER THAN NORMAL.
THE NEXT CHANCE FOR MEASURABLE PRECIPITATION WILL BE LATE THIS
COMING WEEK AS A DEEP TROUGH MOVES IN FROM THE NORTHWEST. THE
MODELS CONTINUE TO BRING DEEP COLD AIR IN BEHIND THE FRONT...WITH
-7C 850MB TEMPS POSSIBLE NEXT SATURDAY NIGHT. EXPECT TEMPERATURES
NEXT WEEKEND TO BE BELOW NORMAL...WITH RAIN SHOWERS POSSIBLE OUT
AHEAD OF THE FRONT...FOLLOWED BY A RIBBON OF MIXED
PRECIPITATION...AND SNOW SHOWERS BEHIND. THERE IS TO MUCH
VARIABILITY TO GIVE A GOOD QUANTIFICATION OF SNOW AMOUNTS.
HOWEVER...CURRENTLY ANY ACCUMULATIONS SEEM TO BE LIGHT. THE EC
CONTINUES TO SLOWS THE SYSTEM DOWN...ABOUT 12 HRS SLOWER THAN THE
GFS. HOWEVER BOTH MODELS HAVE A SIMILAR ORIENTATION..THOUGH THE EC
HAS A DEEPER LOW THAT IS FURTHER SOUTH.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
ADJUSTED 12Z TAFS FOR EXPANDING AREA OF LOWER CLDS. STILL
EXPECT THESE CLDS TO BREAK UP BY LATE MORNING.
OTHERWISE...HIGH PRESSURE ACROSS EASTERN CANADA AND THE NEW
ENGLAND STATES WILL REMAIN NEARLY STATIONY FOR THE NEXT FEW
DAYS...BRINGING MAINLY CLEAR SKIES TO THE AREA.
OUTLOOK...
WED...PATCHY AM VALLEY FOG POSSIBLE ACROSS THE ALLEGHENIES.
THU-FRI...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DEVOIR
NEAR TERM...DEVOIR/LAMBERT/MARTIN
SHORT TERM...DEVOIR/LAMBERT
LONG TERM...DEVOIR/CERU
AVIATION...FITZGERALD/MARTIN
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
550 AM CST MON NOV 19 2012
.SHORT TERM...THROUGH WEDNESDAY NIGHT
200 AM CST MON NOV 19 2012
MAIN FORECAST CONCERNS ARE ON PRECIPITATION CHANCES TODAY AND HOW
WARM WE WILL GET ON WEDNESDAY.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED A DEEP TROUGH JUST OFF BRITISH COLUMBIA...THEN A
WEST-SOUTHWEST FLOW FROM CALIFORNIA INTO THE WESTERN GREAT LAKES
REGION. WITHIN THIS FLOW...A WEAK SHORTWAVE TROUGH STRETCHED FROM
WESTERN IOWA INTO CENTRAL KANSAS. AHEAD OF THIS SHORTWAVE TROUGH...A
PLUME OF PRECIPITABLE WATER VALUES OF 0.75 INCHES OR SO CAN BE SEEN
ON GOES DERIVED IMAGERY...STREAMING NORTH FROM OKLAHOMA INTO NORTH
CENTRAL IOWA. PROFILER AND VWP DATA SHOWED 850MB WINDS OF 30-40 KT
WITHIN THIS PLUME OF MOISTURE...HELPING TO ADVECT IT NORTHEAST
TOWARDS THE FORECAST AREA. THE COMBINATION OF THIS MOISTURE
TRANSPORT AND WEAK DPVA AHEAD OF THE SHORTWAVE TROUGH HAS BEEN
SUPPORTING A BAND OF SHOWERS JUST EAST OF I-35 IN IOWA. IN
ADDITION TO THE ADVECTION OF MOISTURE...THE WINDS AS WELL AS
CLOUDS ARE HELPING TO KEEP TEMPERATURES UP IN THE 40S AND EVEN
AROUND 50 AT SOME LOCATIONS. LAST ITEM OF NOTE WAS ANOTHER WEAK
SHORTWAVE TROUGH OVER EASTERN MONTANA. DRIER AIR PRESENT OVER THE
NORTHERN PLAINS...AS SEEN ON THE 00Z BIS AND GGW SOUNDINGS...HAS
KEPT ANY CLOUD COVER TO SCATTERED HIGH BASED ALTOSTRATUS AND
CIRRUS WITH THIS SHORTWAVE TROUGH.
TODAY AND TONIGHT...THE SHORTWAVE TROUGH JUST OFF TO OUR SOUTHWEST
IS PROGGED TO LIFT NORTHEAST AND MOVE THROUGH MUCH OF THE FORECAST
AREA BY 21Z TODAY. MEANWHILE...THAT NEXT SHORTWAVE TROUGH OVER
MONTANA LOOKS TO DROP DOWN INTO THE FORECAST AREA AFTER 06Z TONIGHT
IN THE WAKE OF THE FIRST TROUGH. MOST OF THE FOCUS IS ON THE
SHORTWAVE TROUGH TODAY AS IT HAS THE MOST MOISTURE TO WORK WITH.
PRECIPITABLE WATER FORECASTS SHOW THE AREA OF MOISTURE IN CENTRAL
IOWA SPREADING NORTHEAST THROUGH THE FORECAST AREA...THEN SLOWLY
SHIFTING EAST THIS AFTERNOON THROUGH TONIGHT AS THE SHORTWAVE TROUGH
EXITS THE FORECAST AREA. SEEING THAT THE WEAK DPVA AND ISENTROPIC
LIFT HAS BEEN ABLE TO PRODUCE THE BAND OF SHOWERS NEAR I-35 IN
IOWA...FEEL CONFIDENT THAT SHOWERS WILL AFFECT THE FORECAST AREA
TODAY. HRRR RUNS SINCE 19.01Z HAVE HAD A GOOD HANDLE ON THE SHOWERS
AND THUS THE FORECAST PRECIPITATION CHANCES ARE CLOSE TO IT. THERE
MAY NOT BE MUCH RAIN...GIVEN WEAK FORCING...BUT RAIN NONETHELESS.
BEST CHANCES ARE THIS MORNING OVER THE EASTERN TWO THIRDS OF THE
AREA. SKIES LOOK TO STAY CLOUDY THROUGH MUCH OF THE DAY TODAY...
WITH PERHAPS SOME CLEARING COMING IN WESTERN SECTIONS DURING THE
AFTERNOON AS SUBSIDENCE ALONG WITH DRIER AIR FROM THE DAKOTAS
BEGIN TO ADVECT IN. A BETTER CLEARING TREND IS EXPECTED TONIGHT...
ESPECIALLY AFTER MIDNIGHT...ONCE THAT NEXT SHORTWAVE TROUGH MOVES
IN. APPEARS TO BE SOME PRETTY STRONG SUBSIDENCE AND DRYING IN THE
WAKE OF THAT SHORTWAVE TROUGH. ALTHOUGH THERE WILL BE PLENTY OF
CLOUDS AROUND TODAY...ADVECTION AND LIMITED INSOLATION SHOULD BE
ENOUGH FOR ALL LOCATIONS TO CLIMB INTO THE 50S. WESTERN SECTIONS
COULD EVEN REACH THE UPPER 50S GIVEN THAT THEY HAVE POTENTIAL FOR
SOME SUN. COMBINATION OF CLEARING TONIGHT AND A WEAK PRESSURE
GRADIENT SHOULD ALLOW TEMPERATURES TO FALL INTO THE 30S...
ESPECIALLY IN WESTERN SECTIONS WHERE CLEARING IS MOST LIKELY TO
OCCUR.
TUESDAY THROUGH WEDNESDAY NIGHT...THE DEEP UPPER TROUGH OFF THE
BRITISH COLUMBIA IS FORECAST BY ALL MODELS TO MOVE ACROSS THE
PACIFIC NORTHWEST AND NORTHERN U.S. ROCKIES DURING THIS PERIOD...AS
A FAIRLY POTENT SHORTWAVE TROUGH...RESULTING IN THE FORMATION OF A
LOW PRESSURE SYSTEM DOWNSTREAM IN THE NORTHERN PLAINS. AS THIS
TROUGH MOVES ACROSS...STRONG UPPER RIDGING DEVELOPS DOWNSTREAM INTO
THE FORECAST AREA BY 12Z WEDNESDAY. WITH THIS RIDGING COMES A PLUME
OF DOWNSLOPED WARM AIR OFF THE ROCKIES. INITIALLY 850MB TEMPS ARE ON
THE RELATIVELY COOL SIDE ON TUESDAY...ONLY 4-6C OR SO AT 18Z...
CAUSED BY THAT SHORTWAVE DROPPING INTO THE AREA TONIGHT. STILL...
PLENTY OF SUN THANKS TO STRONG SUBSIDENCE AND DRYING IN THE WAKE OF
THE SHORTWAVE SHOULD ALLOW FOR GOOD MIXING...WITH HIGHS CLIMBING
INTO THE UPPER 40S TO MIDDLE 50S. WINDS WILL BE LIGHT TOO WITH A
SURFACE HIGH PRESSURE RIDGE CROSSING. COULD SEE A DECENT TEMPERATURE
DROP TUESDAY EVENING WITH FAVORABLE RADIATIONAL COOLING CONDITIONS
IN PLACE...ESPECIALLY ACROSS WISCONSIN WHERE THE RIDGE LINGERS
LONGEST. THE SOUTHERLY WINDS THEN PICK UP AFTER MIDNIGHT AND
ESPECIALLY FOR WEDNESDAY INTO WEDNESDAY NIGHT AS THE PRESSURE
GRADIENT TIGHTENS. 850MB TEMPS RESPOND BY WARMING TO AT LEAST 9-12C
PER MODEL CONSENSUS...OR CLOSE TO 2 STANDARD DEVIATIONS ABOVE
NORMAL. 925MB TEMPS ARE SIMILAR TO THOSE AT 850MB. SUBSIDENCE AND
DRY AIR ASSOCIATED WITH THE UPPER RIDGE WILL ALLOW FOR SUNNY
SKIES...SO CONDITIONS ARE FAVORABLE FOR MIXING. BIGGEST QUESTION
MARK IS CAN WE MIX TO 925MB. 00Z GFS/NAM SOUNDINGS SAY THE BEST WE
CAN DO IN OUR AREA IS 950MB...WHILE FARTHER WEST SAY IN SOUTH
CENTRAL AND SOUTHWEST MINNESOTA...MIXING ENDS UP BEING TO 925-900MB.
THE CAUSE FOR THE DIFFERENCE IN MIXING IS DUE TO HOW COLD WE GET
TUESDAY NIGHT. THINK THE NAM IS TOO COLD...PLUS THE WINDS PICKING UP
AFTER MIDNIGHT ESPECIALLY IN SOUTHEAST MINNESOTA MAY EVEN CAUSE
TEMPERATURES TO CLIMB. THE GFS LOOKS A LITTLE MORE REPRESENTATIVE
AND THUS IS A LITTLE WARMER THAN THE NAM FOR HIGHS. FOR NOW HAVE
LEFT THE PREVIOUS FORECAST HIGHS ALONE...THOUGH IT IS POSSIBLE THEY
NEED TO BE LOWERED. IN ANY EVENT...WEDNESDAY NIGHT LOOKS MILD
WITH THE AREA IN THE WARM SECTOR AND A PERSISTENT SOUTHERLY BREEZE
HELPING TO HOLD TEMPERATURES UP. STAYED TOWARDS THE WARM SIDE OF
GUIDANCE FOR LOWS.
.LONG TERM...THANKSGIVING THROUGH SUNDAY NIGHT
200 AM CST MON NOV 19 2012
MAIN HEADLINE HERE IS THE DRAMATIC TEMPERATURE FALL POSSIBLE
BETWEEN THANKSGIVING AND FRIDAY.
19.00Z ECMWF/CANADIAN/UKMET/GFS AND GFS ENSEMBLES ARE IN MUCH BETTER
AGREEMENT THAN YESTERDAY. ALL MODELS NOW HAVE THAT POTENT TROUGH
DIGGING INTO OUR REGION FOR THURSDAY NIGHT INTO FRIDAY...BRINGING
WITH IT A PORTION OF COLD CANADIAN AIR THAT HAS BEEN BUILDING UP IN
THE YUKON TERRITORY. THE POTENT TROUGH IS VERY PROGRESSIVE...DUE TO
NEW TROUGHING DEVELOPING OVER THE PACIFIC NORTHWEST BY THE END OF
THE WEEKEND...PUSHING UPPER RIDGING TOWARDS THE AREA. NOTE THAT THE
19.00Z GUIDANCE SUGGESTS THIS UPPER RIDGING IS FLATTER...THUS THE
WARM UP IS NOT AS INTENSE AS WHAT THE 18.12Z ECMWF SUGGESTED. PLENTY
OF TIME FOR THIS CHANGE ONE WAY OR THE OTHER OVER THE NEXT FEW
DAYS...THOUGH.
THE BIGGEST ISSUE WITH THE UPPER TROUGH ENTERING THE AREA EARLY IN
THE PERIOD IS TIMING OF THE MAIN COLD FRONT WITH IT...WITH THE
UKMET/GFS FASTER THAN THE CANADIAN/ECMWF. AT 00Z FRIDAY...THE FORMER
HAS THE FRONT THROUGH THE AREA WHILE THE LATTER HAS THE FRONT COMING
INTO WESTERN SECTIONS OF THE AREA. THIS HAS SIGNIFICANT IMPLICATIONS
ON TEMPERATURES FOR THANKSGIVING DAY...GIVEN THAT READINGS WILL
START OFF MUCH WARMER THAN THOSE ON TUESDAY NIGHT...THUS ALLOWING
FOR BETTER MIXING POTENTIAL. PLUS...925MB TEMPS MAY NOT COOL MUCH
UNTIL LATE IN THE DAY. FOR NOW HAVE STAYED CLOSE TO THE PREVIOUS
FORECAST FOR HIGHS UNTIL THE FRONTAL TIMING CAN BE IRONED OUT.
ONE OTHER ISSUE FOR THANKSGIVING DAY IS THAT THE GFS/CANADIAN
PRODUCE QPF OVER THE SOUTHEAST HALF OF THE FORECAST AREA. THIS QPF
IS RELATED TO A SUBTROPICAL SHORTWAVE EJECTING OUT OF AN UPPER LOW
CROSSING NORTHERN MEXICO ON WEDNESDAY. EVERY MODEL SUGGESTS A PLUME
OF HIGHER MOISTURE STREAMING UP INTO THE FORECAST AREA ON
THANKSGIVING...AHEAD OF THE WARM FRONT...NOTED BY 850MB DEWPOINTS
CLIMBING TO 4C OR SO. NEW 19.00Z ECMWF NOW PRODUCES QPF TOO BY
BRINGING THAT SHORTWAVE UP...THOUGH LIGHTER AND OUTSIDE FOR THE
FORECAST AREA. WITH GOOD AGREEMENT ON THE SHORTWAVE COMING UP
THROUGH THE MOISTURE STREAM...KEPT THE CONSENSUS APPROACH ADDITION
OF 20 PERCENT CHANCES FOR THE SOUTHEAST HALF ON THANKSGIVING.
AFTER THE MAIN FRONTAL PASSAGE...ATTENTION TURNS TO WINDS AND
TEMPERATURES AS COLD AIR FILTERS IN. IT APPEARS THE COLDEST AIR
WAITS UNTIL FRIDAY...ASSOCIATED WITH A SECONDARY COLD FRONTAL
PASSAGE. FOR EXAMPLE...850MB TEMPS AT 06Z FRIDAY ARE GENERALLY IN
THE RANGE OF -3C WEST TO 1C EAST. BY 18Z FRIDAY...EVERYONE IS SEEING
850MB TEMPS BETWEEN -10 AND -13C. THUS...TEMPERATURES PROBABLY ARE
NOT GOING TO RISE MUCH ABOVE MORNING LOWS...AND IF ANYTHING POSSIBLY
FALL. GOOD MIXING SETUP TOO GIVING COLD ADVECTION DURING THE DAYTIME
AND UNIDIRECTIONAL LOW LEVEL WINDS. SUSTAINED 15-20 KT WINDS LOOK
REASONABLE WITH GUSTS OF 30-35 KT AT LEAST WEST OF THE MISSISSIPPI
RIVER.
THINGS CALM DOWN FOR FRIDAY NIGHT AND THE WEEKEND AS A RIDGE OF HIGH
PRESSURE CROSSES THE AREA AND BEGINS A WARM UP.
&&
.AVIATION...TODAY AND TONIGHT
545 AM CST MON NOV 19 2012
WATER VAPOR IMAGERY SHOWING A SHORT WAVE MOVING THROUGH NORTHEAST
IOWA. THIS SYSTEM WILL PRODUCE SHOWERS IN THE KLSE AREA THROUGH
19.15Z. IN ITS WAKE...EXPECT CEILINGS TO REMAIN AROUND 5K FEET FOR
THE REMAINDER OF THIS MORNING.
FOR THIS AFTERNOON AND TONIGHT...THE MAIN CONCERN WILL BE THE
CLOUD COVER. THE INFRARED SATELLITE SHOWS SOME CLEARING IN THE
WAKE OF THIS SHORTWAVE. IF IT CONTINUES ON CURRENT SPEED...THE
CLEARING WOULD REACH KRST AROUND 19.18Z AND KLSE AROUND 19.21Z.
WITH ALL OF DETERMINISTIC MODELS INSISTENT THAT THE CLOUDS WILL
REMAIN ACROSS THE AREA THROUGH THE NIGHT...DECIDED TO COMPROMISE A
BIT AND HAVE THE CLEARING TAKE PLACE AT KRST AROUND 20.00Z AND AT
KLSE AROUND 20.03Z.
FOR LATE TONIGHT...THE MODELS SHOW THAT A COLD FRONT WILL MOVE
THROUGH THE AREA. THIS FRONT WILL SHIFT THE WINDS FROM THE SOUTH
TO WEST. IN ADDITION...THE MODELS ARE INSISTENT THAT THERE WILL BE
MVFR CEILINGS IN ITS WAKE. THE MODELS SEEM TO BE OVERDOING THESE
CLOUDS...BECAUSE THERE ARE NO LOW CLOUDS ANYWHERE ACROSS THE
DAKOTAS. DUE TO THIS...JUST WENT WITH A SCATTERED DECK OF CLOUDS.
&&
.CLIMATE...
200 AM CST SUN NOV 18 2012
RECORD HIGH TEMPERATURES FOR WEDNESDAY/21ST AND THURSDAY/22ND. COOP
SITES ARE 6AM-6AM HIGHS...THUS 22ND HIGHS ARE 21.12Z TO 22.12Z. LA
CROSSE AND ROCHESTER ARE ONLY NON-COOP SITES.
FORECAST HIGH TEMPERATURES SUGGEST SOME OF THE RECORDS BELOW MAY
BE TIED OR BROKEN.
LOCATION WEDNESDAY/21ST THURSDAY/22ND
LA CROSSE WI 72/1990 59/1963
SPARTA WI 65/1990 70/1990
MEDFORD WI 59/1913 65/1990
LANCASTER WI 66/2003 66/1898
MAUSTON WI 67/2003 66/1990
ROCHESTER MN 69/1990 65/1913
AUSTIN MN 70/1990 58/1966
WINONA DAM 5A MN 60/2003 60/2001
WABASHA MN 61/1908 59/1908
CHARLES CITY IA 71/1990 62/1966
OELWEIN IA 71/1990 62/1966
DECORAH IA 71/1990 62/1908
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
200 AM CST MON NOV 19 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...BOYNE
CLIMATE......JONES/DB/AJ
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1034 AM CST MON NOV 19 2012
.DISCUSSION...
ISSUED 1035 AM CST MON NOV 19 2012
UPDATED THE FORECAST TODAY TO INCREASE CHANCES OF SHOWERS OVER THE
IL RIVER VALLEY INTO MIDDAY TO 50% AND ALSO TO INCREASE CLOUD
COVER ACROSS AREA TODAY. GENERALLY A MOSTLY CLOUDY DAY WITH CHANCE
OF SHOWERS WEST OF I-55 INTO EARLY AFTERNOON. HIGHS IN THE UPPER 50S
OVER CENTRAL IL AND AROUND 60F SE OF I-70. SOUTH WINDS 5 TO 15 MPH.
1034 MB HIGH PRESSURE OVER NEW ENGLAND WAS STILL RIDGING SW INTO
THE MID/LOWER MS VALLEY WHILE A COLD FRONT WAS FROM NW MN INTO SE
NEBRASKA. RADAR MOSAIC SHOWS A SMALL BAND OF MAINLY LIGHT RAIN
SHOWERS OVER WESTERN IL INTO EASTERN MO AND FAR SE IA LIFTING NE
TOWARD THE IL RIVER LATE THIS MORNING. THESE LIGHT SHOWERS
ASSOCIATED WITH A WEAK UPPER LEVEL DISTURBANCE EMBEDDED IN AN
UPPER LEVEL TROF OVER THE MIDWEST. THIS FEATURE SHOULD EXIT
CENTRAL/NORTHERN IL DURING THE AFTERNOON WITH LIGHT SHOWERS
DIMINISHING OVER THE IL RIVER VALLEY. TEMPS CURRENTLY RANGE FROM
45 TO 55F AND CLOUDS WILL LIMIT WARMING WITH HIGHS IN THE UPPER
50S CENTRAL IL AND NEAR 60F IN SE IL.
07
&&
.AVIATION...
ISSUED 559 AM CST MON NOV 19 2012
PREDOMINANTLY VFR CONDITIONS EXPECTED ACROSS THE CENTRAL ILLINOIS
TERMINALS THROUGH THE 12Z TAF VALID TIME. HOWEVER...THE GRADUAL
PASSAGE OF AN UPPER LEVEL DISTURBANCE WILL CAUSE CIGS TO
THICKEN/LOWER WITH TIME. SOME OF THE MODEL GUIDANCE SUGGESTS MVFR
CIGS WILL DEVELOP BY LATE TONIGHT...BUT THIS IS NOT A UNANIMOUS
AGREEMENT. SOME VERY LIGHT RAIN/SPRINKLES ARE POSSIBLE AS THE
DISTURBANCE STARTS TO PUSH THROUGH...BUT DO NOT EXPECT MUCH IN THE
WAY OF MEASURABLE RAINFALL AT ANY ONE TERMINAL. FOR NOW...HAVE
LIMITED VCSH MENTION TO KPIA/KSPI WHERE THE POTENTIAL RAINFALL
WILL ARRIVE FIRST...WITH A DRYING TREND EXPECTED AS THE PATCHY
RAIN MOVES FURTHER EAST. SOUTHERLY WIND AOB 10 KTS ARE EXPECTED
FOR MOST OF THE PERIOD...BUT THE PASSAGE OF A SURFACE TROF LATER
TONIGHT WILL HAVE WINDS SHIFTING TO THE NORTHWEST.
BAK
&&
.PREV DISCUSSION...
ISSUED 256 AM CST MON NOV 19 2012
OVERALL...NOT A LOT OF CHANGES IN THE FORECAST. MAIN ISSUES ARE
TWO PERIODS OF POTENTIAL PRECIP...AND UNSEASONABLY WARM
TEMPERATURES. PREDOMINANTLY ZONAL FLOW THROUGH THE FORECAST...WITH
A COUPLE OF WAVES ALTERING THE FLOW BRIEFLY. UPPER LOW MOVING JUST
OFF THE SERN ATLANTIC COAST...AND ANOTHER WAVE PUSHING SOME
SHOWERS OVER THE MISSISSIPPI RIVER VALLEY. FIRST ISSUE WILL BE THE
PROGRESSION OF THE SHOWERS INTO ILLINOIS TODAY. OTHER THAN
THAT...WARM TEMPS THROUGH THE FIRST HALF OF THE WEEK PUSHING THE
MAXES OVER GUIDANCE. NOT A LOT OF DISSENSION BETWEEN THE
MODELS...JUST WITH THE MOS. PUSHING FORECAST MORE TOWARDS RAW
SOLUTIONS AS A RESULT. NEXT SHOT AT SHOWERY PRECIP ON TRACK FOR
THANKSGIVING DAY.
SHORT TERM...TODAY AND TONIGHT...
SHOWERS MOVING INTO THE MISS RIVER VALLEY THIS MORNING. A BIT OF
CONFLICT IN HIGH RES MODELS AS TO WHETHER OR NOT IT WILL MAKE IT
INTO CENTRAL IL. HRRR SAYS YES...WITH A SECOND ROUND APPROACHING
FROM THE SW FOR A SECONDARY ENHANCEMENT MID MORNING. 4KM WRF IS A
BIT MORE CONSERVATIVE...NAM AND ECMWF ARE DRY. AS A RESULT...AND
AT LEAST TO COVER FOR SPRINKLES THROUGH THE MORNING WITH
REMNANTS...SLIGHT POPS DOMINATE THE WESTERN THIRD OF THE CWA. WILL
HAVE TO MONITOR CLOSELY...BUT SO FAR THE SOLUTION SEEMS PLENTY AS
THE COVERAGE OF THE SHOWERS IS REDUCING ON RADAR. SHORT LIVED
PRECIP NOT ENOUGH TO COUNTER THE WARM UP THAT CONTINUES TODAY AS
SOUTHERLY WINDS GET A BIT MORE ESTABLISHED THIS AFTERNOON. MILD
TEMPS CONTINUE INTO THE OVERNIGHT YET AGAIN.
LONG TERM...TUESDAY THROUGH SUNDAY...
HIGH PRESSURE RIDGE SLOWLY DRIFTS EASTWARD...OR AT LEAST BECOMES
FAR MORE DIFFUSE FROM THE MIDWEST TO THE SOUTHERN PLAINS...AND
THE CLOSED UPPER LOW KICKS OUT OF THE SE. THE WARMING TREND
CONTINUES THROUGH MID WEEK...BRINGING TEMPS UP A DEGREE OR SO EACH DAY.
850MB TEMPS AT 6-7C WILL HAVE THE POTENTIAL TO TRANSLATE INTO
UPPER 50S/LOWER 60S. GUIDANCE HAS NOT COMPLETELY LATCHED ONTO THE
WARMING TREND...THOUGH THE MODEL FIELDS CLEARLY SHOW THE THERMAL
RIDGE IN THE WESTERN CONUS DEEPENING AND SLOWLY CREEPING INTO THE
MIDWEST. HAVE BUMPED MAX TEMPS A FEW DEGREES AHEAD OF ALLBLEND FOR
MON- WED...AND A BIT ON THURSDAY. THURSDAY MAY BE COMPLICATED BY
AN APPROACHING STORM SYSTEM AND ASSOCIATED CLOUD COVER...BUT
SYSTEM STILL HAS A BIT OF UNCERTAINTY AS FAR AS MID AND LOW LEVEL
MOISTURE FIELDS. ALLBLEND PUSHING POPS TO CHANCE CAT.
HJS
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
315 PM CST MON NOV 19 2012
.SYNOPSIS...
12Z UA ANALYSIS HAS SEVERAL WEAK TROFS FROM THE WESTERN GREAT LAKES
INTO THE ROCKIES. AT 850MB A MOISTURE PLUME EXTENDED FROM THE BAY OF
CAMPECHE UP INTO CENTRAL IOWA. RADAR TRENDS THROUGH EARLY AFTERNOON
SHOW A CONTINUED DECREASE OF THE PRECIPITATION AS THE OVERALL FORCING
WEAKENS. AT THE SAME TIME...LOW CLOUDS HAD DEVELOPED ON THE EASTERN
EDGE OF THE CLEARING AND WERE NOW OVER THE MID MISSISSIPPI VALLEY.
18Z SFC ANALYSIS HAS A VERY WEAK LOW ALONG THE OK/TX BORDER EAST OF
KAMA WITH A TROF EXTENDING NORTH FROM THE LOW INTO NORTHERN
MINNESOTA. A WEAK COLD FRONT RAN FROM NORTHWEST MINNESOTA INTO SOUTH
DAKOTA. DEW POINTS WERE IN THE 40S AND 50S IN A BROAD MOISTURE PLUME
FROM TEXAS INTO IOWA WITH 30S ACROSS THE REMAINDER OF THE MIDWEST
AND PLAINS.
&&
.SHORT TERM...TONIGHT AND TUESDAY...
THE ONLY EXPLANATION FOR THE RAPID DEVELOPMENT OF THE LOW CLOUDS
ACROSS THE CWFA SINCE LATE MORNING IS CONVERGENT FLOW AHEAD OF THE
TROF. THIS CONVERGENCE CONTINUES THIS AFTERNOON SO THE CLOUDS ARE
EXPECTED TO REMAIN ACROSS THE AREA. RADAR TRENDS SUGGEST THE
POTENTIAL FOR SOME SPRINKLES/VERY LIGHT SHRA TO CONTINUE INTO THE
LATE AFTERNOON HOURS AS WELL IN THE EASTERN CWFA.
GOING ON THE ASSUMPTION THAT THE RAP TRENDS ARE CORRECT...THE
OVERALL CONVERGENCE IS PROGGED TO WEAKEN THIS EVENING WHICH SHOULD
ALLOW THE CLOUDS TO PARTIALLY BREAK UP IN THE WESTERN CWFA. IN THE
EASTERN CWFA LINGERING SPRINKLES ARE POSSIBLE EARLY THIS EVENING.
THE RAP TRENDS AFTER MIDNIGHT ARE DISTURBING. THE CONVERGENT FLOW IS
PROGGED TO INCREASE AGAIN AND THE RAP IS INDICATING THAT A WEAK LOW
WILL MOVE ALONG THE TROF INTO THE CWFA PRIOR TO SUNRISE. WITH
PLENTIFUL LOW LEVEL MOISTURE IN PLACE THE CLOUDS ARE EXPECTED TO
RE-DEVELOP OR FOG/STRATUS WILL DEVELOP IN THE CLEAR AREAS. THUS WILL
ADD AREAS OF FOG IN THE WESTERN CWFA AND PATCHY FOG EAST WHERE THE
CLOUDS ARE EXPECTED TO LINGER LONGER.
I CANNOT RULE OUT THE POSSIBILITY OF A HEADLINE FOR THE FOG LATE
TONIGHT INTO TUESDAY MORNING. HOW THE CLOUDS AND POTENTIAL FOG
DEVELOP/EVOLVE LATE TONIGHT WILL BE THE KEY. IF ONE HAD TO ASSIGN A
PROBABILITY IT IS CURRENTLY 1 IN 5 OR 1 IN 4 REGARDING A HEADLINE.
ASSUMING THAT LOW CLOUDS/FOG DEVELOP LATE TONIGHT THEY WILL CONTINUE
INTO TUESDAY MORNING. THE FOG SHOULD LIFT BY LATE MORNING WITH THE
CLOUDS EXPECTED TO CLEAR OUT DURING THE AFTERNOON. THE RATE OF
CLEARING ON TUESDAY IS A CONCERN GIVEN THE WEAK SUN. IT IS ENTIRELY
POSSIBLE THAT THE CLOUDS MAY NOT CLEAR OUT UNTIL CLOSE TO SUNSET
TUESDAY. IF THAT OCCURS...THE CURRENT MAX TEMPERATURES FOR TUESDAY
ARE TOO WARM. ..08..
.LONG TERM...TUESDAY NIGHT THROUGH NEXT MONDAY...
TUESDAY NIGHT AND WEDNESDAY...BOTH SFC AND UPPER RIDGING STILL ON
TRACK TO GET PRESSED ACRS THE REGION THIS PERIOD AS WELL AS
UNSEASONABLY MILD TEMPS. LIGHT WINDS AND CLEAR OUT OF CLOUDS WILL
MAKE FOR A COOLER NIGHT TUE NIGHT WITH LOWS WELL DOWN IN THE 30S.
DEPENDING ON TUE AFTERNOON CLOUD CLEAR OUT...THE LATER THE CLEARING
TREND AND THUS REDUCING THE SFC MIX OUT DRYING...TUE NIGHT MAY BE AN
IDEAL RADIATIONAL FOG SET UP ESPECIALLY ALONG AND EAST OF THE MS RVR.
WILL HOLD OFF MENTION FOR NOW BUT FOLLOWING SHIFTS WILL HAVE TO
ASSESS THIS POTENTIAL. AS FOR WED...TEMPORARY OMEGA BLOCK OVER
STRENGTHENING WARMING LLVL RETURN FLOW STILL APPEAR ON TAP. EXTENT OF
AVERAGED LLVL THERMAL DRAW BY THE MAJORITY OF THE NEW 12Z RUN MODELS
AND MIXING UP INTO BASE ON BUILDING WARM WEDGE ALOFT SUPPORTS
WIDESPREAD HIGHS IN THE UPPER 50S IN THE FAR NORTHEAST...TO THE MID
60S IN THE SOUTHWEST. UNSEASONABLY MILD WED NIGHT AND IF SOUTHERLY
SFC WINDS CAN MAINTAIN AT 5-10 KTS...MANY AREAL TEMPS WILL BE HELD UP
FROM DIPPING BELOW THE MID-UPPER 40S. BUT MAY PLAY IT COOLER IN CASE
OF ANY SFC WIND DECREASE EVEN IF TEMPORARY.
THURSDAY AND FRIDAY... INCOMING PACIFIC NW WAVE ENERGY/DEVELOPING
CYCLONE ACRS THE NORTHERN PLAINS AND ASSOCIATED SFC FRONT PROJECTED
BY LATER RUNS TO SWEEP THROUGH THE DVN CWA THU EVENING. ACTUAL FROPA
OCCURRING ACRS THE MS RVR FROM THE WEST PROGGED BY ENSEMBLE MEAN NOW
LOOKS TO OCCUR AROUND OR JUST AFTER 00Z FRI...THUS THE BULK OF THU
THE DVN CWA TO BE IN BREEZY PRE-FRONTAL WARM SECTOR. STOUT INVERSION
ALOFT AND INCREASE IN LOW-TO-MID LEVEL MOISTURE/CLOUDS COULD BE THE
LIMITING FACTOR AND PREVENT A RECORD MILD THANKSGIVING. IF IT WERE
NOT FOR THOSE FACTORS...SOME AREAS WOULD HIT 70 OR HIGHER. BUT
WILL WITH A MORE CONSERVATIVE LOW TO MID 60S. STRENGTH OF LLVL FRONT
ITSELF AND MID-UPPER LOW ROLLING ACRS THE UPPER MS RVR VALLEY SHOULD
BE ENOUGH TO DEVELOP SOME SHOWERS JUST AHEAD OF THE FRONT THU
AFTERNOON AND EVENING EVEN TAKING INTO ACCOUNT SOMEWHAT LIMITED
MOISTURE RETURN INTO THE FROPA PROCESS. BUT IF LATER RUNS TREND
WETTER...SOME MODERATE SHOWERS AN POSSIBLY EVEN A THUNDERSTORM MAY BE
POSSIBLE THU AFTERNOON/EVENING. IT ALL DEPENDS ON ANY BUILD UP OF
INSTABILITY IF IT CAN AS THU PROGRESSES. DEPENDING ON THE FRONTAL
TIMING...LATE NIGHT SWITCH OVER TO LLVL COLD CONVEYOR COULD PLUNGE
MUCH OF THE NORTHWEST HALF OF THE LOCAL FCST AREA INTO THE LOW TO MID
30S. FRIDAY STILL ON TRACK TO BE A MUCH COLDER BLUSTERY DAY IN
SUBSIDING DRY SLOT OFF GRT LKS CYCLONE...WITH HIGHS HAVING TROUBLE
GETTING OUT OF THE UPPER 30S TO LOWER 40S AS NORTHWEST WINDS GUST
OVER 30 MPH. WRAP AROUND SNOW FLURRIES/SHOWERS MAY NOT BE ALL THAT
FAR AWAY FROM THE LOCAL AREA ACRS SOUTHERN WI. IF SFC WINDS DECOUPLE
UNDER CLEAR SKIES FRI NIGHT...LOWS COULD DIP INTO THE LOWER 20S TO
EVEN UPPER TEENS IN SOME LOCATIONS BY EARLY SAT MORNING.
SATURDAY THROUGH NEXT MONDAY...LATEST RUN OF THE MEDIUM RANGE
SOLUTIONS AND ENSEMBLES SUGGEST A QUICK RETURN TO PROGRESSIVE
WESTERLIES/ FLATTENED FLOW PATTERN ACRS MUCH OF THE CONUS...THUS DRY
AND THERMALLY MODERATING WX INTO SUNDAY AND SUNDAY NIGHT. HIGHS BY
SUNDAY BACK INTO THE MID 40S TO NEAR 50 WITH SOME RETURN FLOW MIXING
AND INSOLATION. AS FOR EARLY TO MID NEXT WEEK...NORTHERN HEMISPHERIC
TELECONNECTIONS SUGGEST ENOUGH WAVE ENERGY/UPPER JET INFLUX DIGGING
INTO THE WEST FOR AN EVENTUAL L/W TROF COMPLEX ACRS THE SOUTHWESTERN
ROCKIES AND GRT BSN. MANY COMPLEX PHASING ISSUES TO BE RESOLVED THAT
FAR OUT...BUT THE GENERAL SIGNAL OF A LOADED SOUTHWEST FLOW PATTERN
ACRS THE WESTERN TO MID CONUS WITH COLD AIR TRYING TO DUMP DOWN THE
PLAINS AND UPPER MIDWEST WHILE A WARM MOIST CONVEYOR STREAMS UP
NORTHWARD TO THE LEE OF THE L/W TROF...COULD MAKE FOR A VERY
INTERESTING MID TO LATE WEEK PERIOD. STAY TUNED. ..12..
&&
.AVIATION...
MVFR CIGS ARE EXPECTED TO PERSIST THROUGH 00Z/20 AND POSSIBLY BEYOND
BEFORE LIFTING TO VFR. THE RAP MODEL TRENDS SHOW CONVERGENCE BECOMING
STRONGER AFT 06Z/20 WITH PLENTIFUL MOISTURE IN PLACE. THUS THERE IS
NOW A REAL CONCERN OF IFR/LIFR CONDITIONS DEVELOPING AFT 06Z/20 WITH
THE POTENTIAL FOR VLIFR CONDITIONS. THIS POSSIBILITY IS CURRENTLY NOT
IN THE TAFS THAT WERE ISSUED AT 18Z/19. THE 18Z TAFS WILL BE AMENDED
TO SHOW MVFR CONDITIONS DEVELOPING AFT 06Z/20 WITH POTENTIAL MARGINAL
IFR. ..08..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
08/12
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1149 AM CST MON NOV 19 2012
.UPDATE...
BASED ON CURRENT RADAR AND RAP TRENDS THE FCST HAS BEEN ADJUSTED
SLIGHTLY TO REFLECT WHAT IS CURRENTLY HAPPENING. THE BULK OF THE
PRECIPITATION IS EXITING THE CWFA BUT LINGERING SHRA AND POSSIBLE
SPRINKLES REMAIN. MOST OF THIS LINGERING PRECIPITATION SHOULD END
EARLY THIS AFTERNOON.
MORE CLOUDS DEVELOPED MID TO LATE MORNING ACROSS IOWA AT THE START
OF THE CLEARING. THIS CLOUD DEVELOPMENT APPEARS TO BE RELATED TO
SOME INCREASED LIFT AND STEEP MID LEVEL LAPSE RATES. AS SUCH
CLOUDS MAY LINGER A LITTLE LONGER THAN EXPECTED. TEMPERATURES HAVE
BEEN ADJUSTED SOMEWHAT TO REFLECT CLOUDS STICKING AROUND A LITTLE
LONGER THAN PREVIOUSLY THOUGHT. ..08..
&&
.AVIATION...
VFR WX IS EXPECTED THROUGH 06Z/20 AS SHRA DEPART THE AREA. AFT
06Z/20 GUIDANCE IS DEVELOPING IFR/LIFR CONDITIONS. HOWEVER...THE
AMOUNT OF MOISTURE IN THE LOWEST LEVELS OF THE MODELS AT THAT TIME
IS SUSPECT. PRIOR TO SUNRISE TODAY THERE WERE ONLY SPOTTY MVFR/IFR
CONDITIONS IN THE PLAINS. THE 18Z TAFS WERE WRITTEN TO REFLECT
POSSIBLE MVFR CONDITIONS DEVELOPING AFT 06Z/20 WITH 6SM. ..08..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1019 AM MST MON NOV 19 2012
.SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 225 AM MST MON NOV 19 2012
LATEST WV IMAGERY AND RUC H5 ANALYSIS SHOW WESTERLY ZONAL FLOW IN
PLACE ACROSS THE US...WITH SEVERAL LOW AMPLITUDE SHORTWAVE TROUGHS
EMBEDDED WITHIN MEAN FLOW. NEAREST SHORTWAVE TROUGH CURRENTLY
EXTENDS ACROSS EASTERN KS...WITH SUBSIDENCE IN PLACE BEHIND THIS
FEATURE OVER WESTERN KS. A SURFACE TROUGH AXIS CURRENTLY EXTENDS FROM
THE DAKOTAS AND ACROSS WESTERN KS...JUST EAST OF THE CWA BORDER.
OVERALL PATTERN WILL REMAIN QUIET THROUGH THE SHORT TERM...WITH MAIN
STORM TRACK WELL NORTH OF THE CWA AND WEAK SOUTHERN TRACK FAVORING
AREAS SOUTH AND EAST OF OUR CWA. PROGRESSIVE ZONAL PATTERN
TRANSITIONING TO SHORTWAVE RIDGING BY TUE...AND A RETURN TO W-SW FLOW
BY WED NIGHT AS THIS RIDGE SHIFTS EAST AND A SHORT WAVE TROUGH MOVES
WITHIN THE VICINITY OF THE CWA. THERE IS GOOD LARGE SCALE ASCENT
ACROSS CENTRAL KS WITH THIS FEATURE...CLOSE TO OUR EASTERN CWA BORDER.
HOWEVER...MOISTURE PROFILES ARE VERY DRY ESPECIALLY THROUGH ABOUT
600MB. I DECIDED TO KEEP FORECAST DRY FOR NOW IN OUR EASTERN CWA
WITH A FEW SPRINKLES POSSIBLE AT MOST.
UNSEASONABLY WARM TEMPERATURES IN THE UPPER 60S/LOW 70S ARE EXPECTED
THE NEXT THREE DAYS...WITH THE WARMEST ON WED AS LEE TROUGH
STRENGTHENS ALONG KS/CO BORDER. WITH INCREASED AFTERNOON MIXING...WE
SHOULD SEE VERY LOW RH VALUES WED AFTERNOON. CURRENT TROUGH POSITION
KEEPS THE STRONGEST WINDS OVER THE EASTERN CWA WHERE HIGHER RH
VALUES SHOULD BE...SO IT STILL LOOKS LIKE WE WONT NEED A RFW. THIS
WILL PROBABLY NEED TO BE WATCHED SINCE IT COULD BE CLOSE.
.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 225 AM MST MON NOV 19 2012
THURSDAY THROUGH SUNDAY...NORTHERN STREAM SYSTEM WILL PUSH A COLD
FRONT THROUGH EARLY ON THANKSGIVING DAY. WINDS MAY NEED TO BE A
LITTLE STRONGER THAT WHAT THE CRH_INIT GAVE ME ON THURSDAY BUT
APPEAR IN THE BALL PARK. THIS WILL BE SOMETHING THAT UPCOMING SHIFTS
WILL NEED TO WATCH. THERE WILL BE COME COOL DOWN ON THURSDAY WITH
THE COOLEST TEMPERATURES TO ARRIVE ON FRIDAY. AFTER THAT...
TEMPERATURES WILL MODERATE UNTIL LATE SUNDAY WHEN THE NEXT COLD
FRONT WILL ARRIVE. MAIN STORM TRACK/LIFT/MOISTURE REMAIN WELL NORTH
OF THE AREA SO THE DRY FORECAST LOOKS FINE AS DOES ALL THE INIT
GRIDS THAT I WAS GIVEN.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1014 AM MST MON NOV 19 2012
VFR CONDITIONS EXPECTED AT BOTH KGLD AND KMCK THROUGH THE TAF
PERIOD. WINDS WILL BE LIGHT AS HIGH PRESSURE SETTLES INTO THE
REGION BEHIND A WEAK COLD FRONT. A FEW HIGH CLOUDS WILL SPILL
ACROSS THE ROCKIES AND INTO THE PLAINS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...BULLER
AVIATION...024
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1137 AM CST MON NOV 19 2012
.SHORT TERM...
ISSUED AT 314 AM CST MON NOV 19 2012
(TODAY)
MAIN CONCERN TODAY WILL BE PRECIPITATION CHANCES. THIN BAND OF
-SHRA EXTENDING FROM SERN IA INTO CNTRL MO HAS BEEN SHOWING SOME
DECREASE IN INTENSITY IN THE LAST HALF HOUR. SURFACE OBS HAS SHOWN
NO MORE THAN A BRIEF PERIOD OF TRACE -RA WITH CEILINGS REMAIN ABOVE
6000FT AGL. THIS LINE IS BEING FORCED BY A THIN AREA OF LOW LEVEL
MOISTURE CONVERGENCE UNDER A SUBTLE SHORTWAVE TROUGH. THE RAP IS
SHOWING THIS FORCING WEAKENING THE NEXT FEW HOURS AS IT MOVES
NORTHEAST...SO WILL SHOW SCT POPS DIMINISHING TO ISOLD OVER NERN
MO/W CNTRL IL BETWEEN 12-15Z. A MORE SUBSTANTIAL AREA OF -RA IS
CURRENTLY ENTERING SWRN MO AHEAD OF SHORTWAVE NOW OVER THE CENTRAL
PLAINS. RAP/GFS/WRF MODELS ARE SHOWING THIS WAVE DAMPENING OUT
TODAY AS A STRONGER SHORTWAVE BEGINS TO DIG SOUTHEASTWARD OUT OF
THE NORTHERN PLAINS. NET EFFECT WILL BE THAT LOW-MID LEVEL FORCING
FOR THIS SECOND AREA OF RAIN WILL DIMINISH THROUGH THE DAY AS IT
MOVES NORTHEAST INTO THE CWA. TIME CROSS SECTIONS FROM THE VARIOUS
MODELS ARE SHOWING A NOTABLE LAYER OF DRY AIR REMAINING AT AND
BELOW 850MB OVER THE SOUTHERN AND EASTERN PART OF THE CWA. THE
DIMINISHING FORCING AND DRY AIR CALL FOR MAINLY CHANCE POPS OVER
CNTRL/NERN MO AND W CNTRL IL WITH JUST SLIGHT CHANCES ELSEWHERE.
EXPECT MOSTLY CLOUDY/CLOUDY SKIES OVER MOST OF THE CWA TODAY...SO
WILL GO WITH A BLEND OR LEAN TOWARD THE COOLER NAM MOS TO
TEMPERATURES TODAY.
BRITT
&&
.LONG TERM...
ISSUED AT 314 AM CST MON NOV 19 2012
(TONIGHT THROUGH SUNDAY)
A SHORTWAVE WILL DROP SEWD THROUGH THE REGION TGT AND TUE SENDING A
WEAK COLD FRONT THROUGH OUR FORECAST AREA LATE TGT AND TUE MRNG.
ALTHOUGH MOST OF THE PRECIPITATION WILL SHIFT E OF THE AREA BY THIS
EVNG...IT APPEARS THAT THERE MAY STILL BE SOME SPRINKLES ACROSS
MAINLY SERN MO AND IL WITH WEAK LOW LEVEL WAA AHEAD OF THE FRONT
AND LINGERING LOW-MID LEVEL MOISTURE. SHOULD SEE GRADUAL CLEARING
FROM NW TO SE LATE TGT AND TUE AS THE LOW LEVEL MOISTURE GETS
SHUNTED TO THE SE WITH WEAK CAA ON TUE BEHIND THE COLD FRONT/850
MB TROUGH. TEMPERATURES WILL STILL BE ABOVE NORMAL ON TUE. COOLER
LOW TEMPERATURES CAN BE EXPECTED TUE NGT DUE TO A CLEAR SKY AND
LIGHT SFC WIND WITH A RELATIVELY WEAK SFC RIDGE OVER OUR AREA. AN
UPPER LEVEL RIDGE OVER MO...ALONG WITH FULL SUNSHINE AND SFC WINDS
BECOMING SLY WILL LEAD TO UNSEASONABLY WARM CONDITIONS FOR NERN
AND CNTRL MO ON WED. THESE WARM CONDITIONS WILL CONTINUE WED NGT
AND THANKSGIVING DAY DUE TO INCREASING S-SWLY LOW LEVEL WINDS.
ALTHOUGH THE ECMWF AND GFS MODELS STILL HAVE DIFFERENCES FOR THU
AND FRI THERE SOLUTIONS HAVE BECOME MORE SIMILAR THAN THEY WERE
THE PAST COUPLE OF DAYS. IT APPEARS THAT THE GFS HAS SOME FEEDBACK
PROBLEMS WED NGT AND THU AND IS LIKELY BRINGING PRECIPITATION
INTO OUR AREA A LITTLE TOO EARLY ON THU. PREFER THE ECMWF MODEL
WHICH HAS MOST OF THE PRECIPITATION THU NGT AS AN UPPER LEVEL LOW
MOVES SEWD THROUGH THE NRN PLAINS SENDING A STRONG COLD FRONT
SEWD THROUGH OUR AREA THU NGT. THE GFS IS NOW COLDER THAN THE
ECMWF MODEL THU NGT INTO FRI MRNG AND BRINGS THE ZERO DEGREE C
850 MB ISOTHERM SEWD TO STL BY 12Z FRI. THE ECMWF MODEL THOUGH IS
A LITTLE SLOWER AND DEEPER WITH THE UPPER LEVEL LOW MOVING THROUGH
THE NRN PORTION OF THE GREAT LAKES REGION ON FRI AND BRINGS
COLDER AIR INTO OUR REGION FRI AFTN THAN THE GFS. WILL TREND
COLDER WITH TEMPERATURES FRI AND FRI NGT ALTHOUGH NOT AS COLD AS
THE ECMWF MODEL WOULD IMPLY. A WARMING TREND WILL BEGIN ON SAT OR
SAT NGT ALTHOUGH WILL TRY TO FOLLOW THE SLOWER WARMING OF THE
ECMWF MODEL. NEXT CHANCE OF PRECIPITATION SHOULD HOLD OFF TIL SUN
NGT AS A STORM SYSTEM TAKES SHAPE OVER THE SRN PLAINS.
GKS
&&
.AVIATION...
ISSUED AT 1127 AM CST MON NOV 19 2012
DRY LOW LEVEL AIR HAS TAKEN ITS TOLL ON BATCH OF RAIN SHOWERS THAT
MOVED IN FROM CENTRAL MISSOURI THIS MORNING. ONLY ISOLATED
SHOWERS OR SPRINKLES REMAIN AND RADAR TRENDS CONFIRM THAT EVEN
THIS CONTINUES TO DIMINISH AS IT PROGRESSES INTO ILLINOIS. CLOUD
BASE GENERALLY VFR...OTHER THAN A SWATH OF MVFR FROM NORTHEAST
MISSOURI TO WEST CENTRAL ILLINOIS. CLOUD COVER SLOWLY MOVING
EAST...WITH CLEARING LINE ALREADY IN CENTRAL MISSOURI. BELIEVE
CLOUD COVER WILL HOLD TOUGH ACROSS EASTERN MISSOURI AND ILLINOIS
TONIGHT WITH MODEL GUIDANCE SHOWING LOWERING OF CEILING HEIGHTS
INTO MVFR CATEGORY. NOT READY TO COMPLETE BITE OFF ON THIS GIVEN
SIGNIFICANT TEMPERATURE/DEWPOINT SPREADS OF +20 ALONG AND EAST OF
THE MISSISSIPPI RIVER. SHOULD SEE IMPROVEMENT TOMORROW AND
CLEARING AS WIND SHIFTS TO THE NORTHWEST WITH FROPA.
SPECIFICS FOR KSTL...
VFR CONDITIONS PREVAIL AS DRY LOW LEVELS HAVE PROHIBITED RAINFALL.
TREND IS FOR CEILING TO GRADUALLY LOWER THIS EVENING AS LOW LEVEL
MOISTURE CONTINUES TO MOVE INTO THE AREA FROM THE SOUTH. NOT SURE
THAT WE WILL SEE MVFR CEILINGS AS MODEL GUIDANCE SUGGESTS.
CLEARING EXPECTED ON TUESDAY MORNING AS WIND SHIFTS TO THE
NORTHWEST BEHIND A COLD FRONT.
CVKING
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1048 AM PST Mon Nov 19 2012
.SYNOPSIS...
Expect a progressive and wet weather pattern with periods of mountain
snow and valley rain this week. Higher snow levels through the middle
of the work week will combine with the heaviest expected
precipitation in this forecast cycle to produce rises on the area
small streams or creeks...especially for North Idaho and the
Cascades. Windy conditions will develop over portions of the Inland
Northwest on Monday.
&&
.DISCUSSION...
Updated much of today`s forecast to reflect the current
radar/satellite/observation trends. Rain shadow is keeping much of
the western Basin dry but HRRR and NAM suggest that a ripple in
the southwesterly flow could offset the shadow for a few hours
of rain this afternoon. Same goes for the L-C valley remaining
mostly dry. Elsewhere rain and mountain snow will continue through
today and then taper off northwest to southeast overnight. The
southeast areas (e.g. southern Palouse, southern Panhandle) will
probably not see an end to the rain as the pseudo-cold front will
stall out over that area tonight.
Also adjusted many of the high temperatures upward for today.
Already into the lower 60s in the lower Columbia Basin and lower
50s into the upper basin.
On the wind front, we decided to downgrade the High Wind Warning
over the Palouse and Pomeroy areas to a Wind Advisory. The winds
aloft certainly support a warning, but mixing that wind down to
the surface is very difficult in this situation of warm advection
and rain-cooled air. Gusts to 40 mph will be fairly common but
damaging winds should remain in the upper elevations, so left the
warning in place for the Blue Mountains.
&&
.AVIATION...
18Z TAFs: Strong warm front will bring periods of -RA/RA to most of
the sites at least through 00z Tue. The exceptions will be in the
lee of the Cascades, KEAT and KWMH, as well as KLWS due to
downslope wind influence. The remaining sites which will see the
precipitation will generally experience VFR cigs...however during
heavier spurts of rain...brief MVFR cigs will be psbl. The threat
was not great enough to list as a prevailing condition. Much of
the precipitation threat will wane during the evening. A weak cold
front will sweep through the area overnight and will likely bring
another batch of rain and lower cigs to most of the sites.
Confidence is fair as most of the MOS data was hinting at MVFR
cigs and psbly IFR ones developing aft 09z or so. The other
concern through the day will be winds. Strong winds of 40-50 kts
will remain poised about 1k above the ground. Whether these can
mix down is the big question. Typically warm fronts accompanied by
widespread precipitation do not allow the atmosphere to fully mix
and this is the way we will trend the forecast. Even so breezy
conditions with sustained speeds of 15-22kts are expected at most
sites with gusts in the 28-35kt range. Winds will decrease before
midnight. fx
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 47 42 46 39 44 32 / 100 100 80 80 80 40
Coeur d`Alene 47 41 46 38 44 33 / 100 100 90 90 80 40
Pullman 50 42 50 40 44 34 / 100 100 90 80 80 30
Lewiston 57 46 55 43 51 38 / 20 100 80 60 70 20
Colville 46 39 47 39 43 33 / 100 80 80 90 80 40
Sandpoint 44 38 45 37 43 34 / 100 100 100 100 100 70
Kellogg 43 40 44 37 41 33 / 100 100 100 100 100 60
Moses Lake 56 42 49 38 47 33 / 30 40 50 40 50 10
Wenatchee 56 40 47 38 44 35 / 70 30 60 50 50 20
Omak 48 40 45 36 42 31 / 100 50 60 60 60 20
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Flood Watch through late Tuesday night for Central Panhandle
Mountains-Coeur d`Alene Area-Idaho Palouse-Northern
Panhandle.
Winter Storm Warning until 4 PM PST this afternoon for Central
Panhandle Mountains-Northern Panhandle.
Wind Advisory until 10 PM PST this evening for Coeur d`Alene
Area-Idaho Palouse-Lewis and Southern Nez Perce Counties-
Lewiston Area.
WA...Flood Watch through late Tuesday night for Northeast Mountains-
Okanogan Highlands-Spokane Area-Washington Palouse.
Winter Storm Warning until 4 PM PST this afternoon for Northeast
Mountains-Okanogan Highlands.
High Wind Warning until 10 PM PST this evening for Northeast
Blue Mountains.
Wind Advisory until 10 PM PST this evening for Lower Garfield
and Asotin Counties-Moses Lake Area-Spokane Area-Upper
Columbia Basin-Washington Palouse.
Flood Watch through late tonight for East Slopes Northern
Cascades.
Winter Storm Warning until 10 PM PST this evening for East
Slopes Northern Cascades.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
250 PM CST MON NOV 19 2012
.SHORT TERM...
250 PM CST MON NOV 19 2012
MAIN FORECAST CONCERN IS ON SKY CONDITIONS TONIGHT AND THEN
TEMPERATURES THROUGH THE REMAINDER OF THE PERIOD.
18Z WATER VAPOR IMAGERY SHOWS A SHORTWAVE OVER NORTHERN
ILLINOIS/EASTERN IOWA...WHILE ANOTHER SHORTWAVE WAS LOCATED OVER
NORTH DAKOTA. THIS LEAD SHORTWAVE IS SPREADING THE SCATTERED
SHOWERS INTO EASTERN WISCONSIN. MEANWHILE...VISIBLE SATELLITE
IMAGERY SHOWS BACK EDGE OF CLOUDS EXTENDING FROM NEAR THE TWIN
CITIES TO CHARLES CITY IOWA AND MOVING STEADILY EASTWARD.
19.12Z MODELS IN GOOD AGREEMENT THROUGH THE PERIOD WITH THE OVERALL
PATTERN. STILL SOME TIMING DIFFERENCES WITH FRONT THE MOVES THROUGH
THE AREA THANKSGIVING DAY...BUT LOOK TO HAVE MINIMAL IMPACT ON THE
SENSIBLE WEATHER.
IN THE NEAR TERM...LEAD SHORTWAVE WILL PUSH NORTHEAST AWAY FROM THE
AREA THIS EVENING...WITH CLEARING SKIES IN ITS WAKE ACROSS MAINLY
THE WESTERN COUNTIES. HOWEVER...SECOND WAVE DROPPING FROM THE
NORTHERN PLAINS WILL PUSH A COLD FRONT TOWARDS THE AREA THIS
EVENING. 19.12Z NAM/19.16Z RAP BUFKIT SOUNDINGS INDICATING THE
DEVELOPMENT OF STRATUS ACROSS THE AREA TONIGHT...THIS ALSO IN LINE
WITH INCREASING PROBABILITIES IN THE 19.09Z SREF. THUS AFTER SOME
CLEARING EARLY THIS EVENING IN THE WEST...EXPECT STRATUS TO DEVELOP
THROUGH THE OVERNIGHT HOURS BEFORE DRIER AIR ADVECTS INTO THE AREA
AFTER 09Z-12Z. DID INCREASE SKY COVER TONIGHT FROM PREVIOUS FORECAST.
STRATUS WILL BREAK UP TUESDAY MORNING..WITH ATTENTION THEN TURNING
TO UPPER RIDGE BUILDING IN AND ITS AFFECT ON TEMPERATURES. 925MB
TEMPERATURES CLIMB FROM 7 TO 9 DEGREES ON TUESDAY...TO 10 TO 13
DEGREES ON WEDNESDAY. WITH PLENTY OF SUNSHINE EXPECTED ALONG WITH
MIXING TO BETWEEN 925MB-950MB...EXPECT TEMPERATURES TO WARM TO WELL
ABOVE GUIDANCE VALUES. 850MB TEMPERATURE ANOMALIES ARE NEARLY 2
STANDARD DEVIATIONS ABOVE NORMAL ON WEDNESDAY AND THUS EXPECT
TEMPERATURES NEAR RECORDS IN SOME LOCATIONS (SEE CLIMATE SECTION
BELOW FOR A LIST OF RECORDS). WITH A CONTINUED SOUTHERLY FLOW
WEDNESDAY NIGHT...MILD TEMPERATURES WILL CONTINUE WITH LOWS ONLY IN
THE 40S.
ON THURSDAY...RIDGE BREAKS DOWN AS SHORTWAVE ROTATES ACROSS THE
PLAINS PUSHING A COLD FRONT ACROSS THE AREA THROUGH THE DAY. STILL
SOME SLIGHT TIMING DIFFERENCES BETWEEN THE MODELS...BUT THE COLDER
AIR LOOKS TO LAG BEHIND THE FRONT...NOT ARRIVING UNTIL THURSDAY
NIGHT. A PLUME OF LOW LEVEL MOISTURE AHEAD OF IT STREAMING INTO
SOUTHWEST AND CENTRAL WISCONSIN. 19.12Z GFS IS SHOWING 100 TO 150
J/KG OF MOST UNSTABLE CAPE WITH THE MOISTURE PLUME AND DOES GENERATE
SOME SHOWERS. DID KEEP THE LOWER END PROBABILITIES WITH THIS FEATURE
ACROSS MAINLY THE SOUTHEASTERN HALF OF THE FORECAST AREA.
BY THURSDAY NIGHT FRONT WILL BE EAST OF THE AREA..WITH THE UPPER
LEVEL TROUGH SWINGING THROUGH NORTHERN WISCONSIN. DID ADD LOWER END
PRECIPITATION CHANCES TO THE FAR NORTH FOR A CHANCE OF RAIN/SNOW.
.LONG TERM...
250 PM CST MON NOV 19 2012
SYSTEM DEPARTS ON FRIDAY...WITH CYCLONIC FLOW ACROSS THE AREA.
TEMPERATURES WILL BE BELOW NORMAL WITH HIGHS MAINLY IN THE 30S. MAIN
PRECIPITATION CHANCE WILL BE ACROSS THE FAR NORTH.
OTHERWISE...REMAINDER OF THE PERIOD WILL BE DOMINATED BY SEASONAL TO
BELOW NORMAL TEMPERATURES. BEST CHANCE FOR ANY PRECIPITATION LOOKS BE
ON MONDAY...BUT MODELS SHOWING SOME DIFFERENCES WITH A DEVELOPING
TROUGH ACROSS THE CENTRAL CONUS. 19.12Z ECMWF SHOWS THIS FEATURE
WITH CYCLOGENESIS OCCURRING...WHILE THE GFS KEEPS FLOW MORE ZONAL. IF
THE ECMWF DOES VERIFY WILL HAVE TO WATCH THIS SYSTEM FOR PERIODS
BEYOND MONDAY.
&&
.AVIATION...THROUGH 18Z TUESDAY
1156 AM CST MON NOV 19 2012
CURRENTLY WATCHING A MID-LEVEL TROUGH AND WEAK SURFACE COLD FRONT
MOVING THROUGH THE REGION. MOST OF THE SCATTERED RAIN SHOWER
ACTIVITY TIED TO THIS MID-LEVEL TROUGH AND FRONT WAS NOW OVER
CENTRAL AND EASTERN WI WITH MID-CLOUD LINGERING ACROSS THE REST OF
THE AREA. SIGNAL IS SHOWING UP TONIGHT FOR STRATUS/FOG POTENTIAL
GIVEN WEAK PRESSURE GRADIENT/LIGHT WINDS AND FAIRLY MOIST LOWER
BOUNDARY LAYER FROM TODAYS SCATTERED RAINFALL. HAVE INCLUDED IFR
STRATUS AT KLSE FROM 06-09Z. NOT AS CONFIDENT AT KRST THOUGH WHERE
LIGHT NORTHWEST WINDS AFTER 06Z AND LACK OF RAINFALL/DRIER LOWER
BOUNDARY LAYER MAY PREVENT WIDESPREAD DEVELOPMENT. THIS WILL HAVE
TO BE MONITORED CLOSELY. LOOKING FOR IMPROVING/VFR CONDITIONS BY
LATE TUESDAY MORNING AS DRIER AIR SPREADS INTO THE AREA.
&&
.CLIMATE...
200 AM CST SUN NOV 18 2012
RECORD HIGH TEMPERATURES FOR WEDNESDAY/21ST AND THURSDAY/22ND. COOP
SITES ARE 6AM-6AM HIGHS...THUS 22ND HIGHS ARE 21.12Z TO 22.12Z. LA
CROSSE AND ROCHESTER ARE ONLY NON-COOP SITES.
FORECAST HIGH TEMPERATURES SUGGEST SOME OF THE RECORDS BELOW MAY
BE TIED OR BROKEN.
LOCATION WEDNESDAY/21ST THURSDAY/22ND
LA CROSSE WI 72/1990 59/1963
SPARTA WI 65/1990 70/1990
MEDFORD WI 59/1913 65/1990
LANCASTER WI 66/2003 66/1898
MAUSTON WI 67/2003 66/1990
ROCHESTER MN 69/1990 65/1913
AUSTIN MN 70/1990 58/1966
WINONA DAM 5A MN 60/2003 60/2001
WABASHA MN 61/1908 59/1908
CHARLES CITY IA 71/1990 62/1966
OELWEIN IA 71/1990 62/1966
DECORAH IA 71/1990 62/1908
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
250 PM CST MON NOV 19 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RABERDING
LONG TERM...RABERDING
AVIATION...DAS
CLIMATE......JONES/DB/AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1156 AM CST MON NOV 19 2012
.SHORT TERM...THROUGH WEDNESDAY NIGHT
200 AM CST MON NOV 19 2012
MAIN FORECAST CONCERNS ARE ON PRECIPITATION CHANCES TODAY AND HOW
WARM WE WILL GET ON WEDNESDAY.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED A DEEP TROUGH JUST OFF BRITISH COLUMBIA...THEN A
WEST-SOUTHWEST FLOW FROM CALIFORNIA INTO THE WESTERN GREAT LAKES
REGION. WITHIN THIS FLOW...A WEAK SHORTWAVE TROUGH STRETCHED FROM
WESTERN IOWA INTO CENTRAL KANSAS. AHEAD OF THIS SHORTWAVE TROUGH...A
PLUME OF PRECIPITABLE WATER VALUES OF 0.75 INCHES OR SO CAN BE SEEN
ON GOES DERIVED IMAGERY...STREAMING NORTH FROM OKLAHOMA INTO NORTH
CENTRAL IOWA. PROFILER AND VWP DATA SHOWED 850MB WINDS OF 30-40 KT
WITHIN THIS PLUME OF MOISTURE...HELPING TO ADVECT IT NORTHEAST
TOWARDS THE FORECAST AREA. THE COMBINATION OF THIS MOISTURE
TRANSPORT AND WEAK DPVA AHEAD OF THE SHORTWAVE TROUGH HAS BEEN
SUPPORTING A BAND OF SHOWERS JUST EAST OF I-35 IN IOWA. IN
ADDITION TO THE ADVECTION OF MOISTURE...THE WINDS AS WELL AS
CLOUDS ARE HELPING TO KEEP TEMPERATURES UP IN THE 40S AND EVEN
AROUND 50 AT SOME LOCATIONS. LAST ITEM OF NOTE WAS ANOTHER WEAK
SHORTWAVE TROUGH OVER EASTERN MONTANA. DRIER AIR PRESENT OVER THE
NORTHERN PLAINS...AS SEEN ON THE 00Z BIS AND GGW SOUNDINGS...HAS
KEPT ANY CLOUD COVER TO SCATTERED HIGH BASED ALTOSTRATUS AND
CIRRUS WITH THIS SHORTWAVE TROUGH.
TODAY AND TONIGHT...THE SHORTWAVE TROUGH JUST OFF TO OUR SOUTHWEST
IS PROGGED TO LIFT NORTHEAST AND MOVE THROUGH MUCH OF THE FORECAST
AREA BY 21Z TODAY. MEANWHILE...THAT NEXT SHORTWAVE TROUGH OVER
MONTANA LOOKS TO DROP DOWN INTO THE FORECAST AREA AFTER 06Z TONIGHT
IN THE WAKE OF THE FIRST TROUGH. MOST OF THE FOCUS IS ON THE
SHORTWAVE TROUGH TODAY AS IT HAS THE MOST MOISTURE TO WORK WITH.
PRECIPITABLE WATER FORECASTS SHOW THE AREA OF MOISTURE IN CENTRAL
IOWA SPREADING NORTHEAST THROUGH THE FORECAST AREA...THEN SLOWLY
SHIFTING EAST THIS AFTERNOON THROUGH TONIGHT AS THE SHORTWAVE TROUGH
EXITS THE FORECAST AREA. SEEING THAT THE WEAK DPVA AND ISENTROPIC
LIFT HAS BEEN ABLE TO PRODUCE THE BAND OF SHOWERS NEAR I-35 IN
IOWA...FEEL CONFIDENT THAT SHOWERS WILL AFFECT THE FORECAST AREA
TODAY. HRRR RUNS SINCE 19.01Z HAVE HAD A GOOD HANDLE ON THE SHOWERS
AND THUS THE FORECAST PRECIPITATION CHANCES ARE CLOSE TO IT. THERE
MAY NOT BE MUCH RAIN...GIVEN WEAK FORCING...BUT RAIN NONETHELESS.
BEST CHANCES ARE THIS MORNING OVER THE EASTERN TWO THIRDS OF THE
AREA. SKIES LOOK TO STAY CLOUDY THROUGH MUCH OF THE DAY TODAY...
WITH PERHAPS SOME CLEARING COMING IN WESTERN SECTIONS DURING THE
AFTERNOON AS SUBSIDENCE ALONG WITH DRIER AIR FROM THE DAKOTAS
BEGIN TO ADVECT IN. A BETTER CLEARING TREND IS EXPECTED TONIGHT...
ESPECIALLY AFTER MIDNIGHT...ONCE THAT NEXT SHORTWAVE TROUGH MOVES
IN. APPEARS TO BE SOME PRETTY STRONG SUBSIDENCE AND DRYING IN THE
WAKE OF THAT SHORTWAVE TROUGH. ALTHOUGH THERE WILL BE PLENTY OF
CLOUDS AROUND TODAY...ADVECTION AND LIMITED INSOLATION SHOULD BE
ENOUGH FOR ALL LOCATIONS TO CLIMB INTO THE 50S. WESTERN SECTIONS
COULD EVEN REACH THE UPPER 50S GIVEN THAT THEY HAVE POTENTIAL FOR
SOME SUN. COMBINATION OF CLEARING TONIGHT AND A WEAK PRESSURE
GRADIENT SHOULD ALLOW TEMPERATURES TO FALL INTO THE 30S...
ESPECIALLY IN WESTERN SECTIONS WHERE CLEARING IS MOST LIKELY TO
OCCUR.
TUESDAY THROUGH WEDNESDAY NIGHT...THE DEEP UPPER TROUGH OFF THE
BRITISH COLUMBIA IS FORECAST BY ALL MODELS TO MOVE ACROSS THE
PACIFIC NORTHWEST AND NORTHERN U.S. ROCKIES DURING THIS PERIOD...AS
A FAIRLY POTENT SHORTWAVE TROUGH...RESULTING IN THE FORMATION OF A
LOW PRESSURE SYSTEM DOWNSTREAM IN THE NORTHERN PLAINS. AS THIS
TROUGH MOVES ACROSS...STRONG UPPER RIDGING DEVELOPS DOWNSTREAM INTO
THE FORECAST AREA BY 12Z WEDNESDAY. WITH THIS RIDGING COMES A PLUME
OF DOWNSLOPED WARM AIR OFF THE ROCKIES. INITIALLY 850MB TEMPS ARE ON
THE RELATIVELY COOL SIDE ON TUESDAY...ONLY 4-6C OR SO AT 18Z...
CAUSED BY THAT SHORTWAVE DROPPING INTO THE AREA TONIGHT. STILL...
PLENTY OF SUN THANKS TO STRONG SUBSIDENCE AND DRYING IN THE WAKE OF
THE SHORTWAVE SHOULD ALLOW FOR GOOD MIXING...WITH HIGHS CLIMBING
INTO THE UPPER 40S TO MIDDLE 50S. WINDS WILL BE LIGHT TOO WITH A
SURFACE HIGH PRESSURE RIDGE CROSSING. COULD SEE A DECENT TEMPERATURE
DROP TUESDAY EVENING WITH FAVORABLE RADIATIONAL COOLING CONDITIONS
IN PLACE...ESPECIALLY ACROSS WISCONSIN WHERE THE RIDGE LINGERS
LONGEST. THE SOUTHERLY WINDS THEN PICK UP AFTER MIDNIGHT AND
ESPECIALLY FOR WEDNESDAY INTO WEDNESDAY NIGHT AS THE PRESSURE
GRADIENT TIGHTENS. 850MB TEMPS RESPOND BY WARMING TO AT LEAST 9-12C
PER MODEL CONSENSUS...OR CLOSE TO 2 STANDARD DEVIATIONS ABOVE
NORMAL. 925MB TEMPS ARE SIMILAR TO THOSE AT 850MB. SUBSIDENCE AND
DRY AIR ASSOCIATED WITH THE UPPER RIDGE WILL ALLOW FOR SUNNY
SKIES...SO CONDITIONS ARE FAVORABLE FOR MIXING. BIGGEST QUESTION
MARK IS CAN WE MIX TO 925MB. 00Z GFS/NAM SOUNDINGS SAY THE BEST WE
CAN DO IN OUR AREA IS 950MB...WHILE FARTHER WEST SAY IN SOUTH
CENTRAL AND SOUTHWEST MINNESOTA...MIXING ENDS UP BEING TO 925-900MB.
THE CAUSE FOR THE DIFFERENCE IN MIXING IS DUE TO HOW COLD WE GET
TUESDAY NIGHT. THINK THE NAM IS TOO COLD...PLUS THE WINDS PICKING UP
AFTER MIDNIGHT ESPECIALLY IN SOUTHEAST MINNESOTA MAY EVEN CAUSE
TEMPERATURES TO CLIMB. THE GFS LOOKS A LITTLE MORE REPRESENTATIVE
AND THUS IS A LITTLE WARMER THAN THE NAM FOR HIGHS. FOR NOW HAVE
LEFT THE PREVIOUS FORECAST HIGHS ALONE...THOUGH IT IS POSSIBLE THEY
NEED TO BE LOWERED. IN ANY EVENT...WEDNESDAY NIGHT LOOKS MILD
WITH THE AREA IN THE WARM SECTOR AND A PERSISTENT SOUTHERLY BREEZE
HELPING TO HOLD TEMPERATURES UP. STAYED TOWARDS THE WARM SIDE OF
GUIDANCE FOR LOWS.
.LONG TERM...THANKSGIVING THROUGH SUNDAY NIGHT
200 AM CST MON NOV 19 2012
MAIN HEADLINE HERE IS THE DRAMATIC TEMPERATURE FALL POSSIBLE
BETWEEN THANKSGIVING AND FRIDAY.
19.00Z ECMWF/CANADIAN/UKMET/GFS AND GFS ENSEMBLES ARE IN MUCH BETTER
AGREEMENT THAN YESTERDAY. ALL MODELS NOW HAVE THAT POTENT TROUGH
DIGGING INTO OUR REGION FOR THURSDAY NIGHT INTO FRIDAY...BRINGING
WITH IT A PORTION OF COLD CANADIAN AIR THAT HAS BEEN BUILDING UP IN
THE YUKON TERRITORY. THE POTENT TROUGH IS VERY PROGRESSIVE...DUE TO
NEW TROUGHING DEVELOPING OVER THE PACIFIC NORTHWEST BY THE END OF
THE WEEKEND...PUSHING UPPER RIDGING TOWARDS THE AREA. NOTE THAT THE
19.00Z GUIDANCE SUGGESTS THIS UPPER RIDGING IS FLATTER...THUS THE
WARM UP IS NOT AS INTENSE AS WHAT THE 18.12Z ECMWF SUGGESTED. PLENTY
OF TIME FOR THIS CHANGE ONE WAY OR THE OTHER OVER THE NEXT FEW
DAYS...THOUGH.
THE BIGGEST ISSUE WITH THE UPPER TROUGH ENTERING THE AREA EARLY IN
THE PERIOD IS TIMING OF THE MAIN COLD FRONT WITH IT...WITH THE
UKMET/GFS FASTER THAN THE CANADIAN/ECMWF. AT 00Z FRIDAY...THE FORMER
HAS THE FRONT THROUGH THE AREA WHILE THE LATTER HAS THE FRONT COMING
INTO WESTERN SECTIONS OF THE AREA. THIS HAS SIGNIFICANT IMPLICATIONS
ON TEMPERATURES FOR THANKSGIVING DAY...GIVEN THAT READINGS WILL
START OFF MUCH WARMER THAN THOSE ON TUESDAY NIGHT...THUS ALLOWING
FOR BETTER MIXING POTENTIAL. PLUS...925MB TEMPS MAY NOT COOL MUCH
UNTIL LATE IN THE DAY. FOR NOW HAVE STAYED CLOSE TO THE PREVIOUS
FORECAST FOR HIGHS UNTIL THE FRONTAL TIMING CAN BE IRONED OUT.
ONE OTHER ISSUE FOR THANKSGIVING DAY IS THAT THE GFS/CANADIAN
PRODUCE QPF OVER THE SOUTHEAST HALF OF THE FORECAST AREA. THIS QPF
IS RELATED TO A SUBTROPICAL SHORTWAVE EJECTING OUT OF AN UPPER LOW
CROSSING NORTHERN MEXICO ON WEDNESDAY. EVERY MODEL SUGGESTS A PLUME
OF HIGHER MOISTURE STREAMING UP INTO THE FORECAST AREA ON
THANKSGIVING...AHEAD OF THE WARM FRONT...NOTED BY 850MB DEWPOINTS
CLIMBING TO 4C OR SO. NEW 19.00Z ECMWF NOW PRODUCES QPF TOO BY
BRINGING THAT SHORTWAVE UP...THOUGH LIGHTER AND OUTSIDE FOR THE
FORECAST AREA. WITH GOOD AGREEMENT ON THE SHORTWAVE COMING UP
THROUGH THE MOISTURE STREAM...KEPT THE CONSENSUS APPROACH ADDITION
OF 20 PERCENT CHANCES FOR THE SOUTHEAST HALF ON THANKSGIVING.
AFTER THE MAIN FRONTAL PASSAGE...ATTENTION TURNS TO WINDS AND
TEMPERATURES AS COLD AIR FILTERS IN. IT APPEARS THE COLDEST AIR
WAITS UNTIL FRIDAY...ASSOCIATED WITH A SECONDARY COLD FRONTAL
PASSAGE. FOR EXAMPLE...850MB TEMPS AT 06Z FRIDAY ARE GENERALLY IN
THE RANGE OF -3C WEST TO 1C EAST. BY 18Z FRIDAY...EVERYONE IS SEEING
850MB TEMPS BETWEEN -10 AND -13C. THUS...TEMPERATURES PROBABLY ARE
NOT GOING TO RISE MUCH ABOVE MORNING LOWS...AND IF ANYTHING POSSIBLY
FALL. GOOD MIXING SETUP TOO GIVING COLD ADVECTION DURING THE DAYTIME
AND UNIDIRECTIONAL LOW LEVEL WINDS. SUSTAINED 15-20 KT WINDS LOOK
REASONABLE WITH GUSTS OF 30-35 KT AT LEAST WEST OF THE MISSISSIPPI
RIVER.
THINGS CALM DOWN FOR FRIDAY NIGHT AND THE WEEKEND AS A RIDGE OF HIGH
PRESSURE CROSSES THE AREA AND BEGINS A WARM UP.
&&
.AVIATION...THROUGH 18Z TUESDAY
1156 AM CST MON NOV 19 2012
CURRENTLY WATCHING A MID-LEVEL TROUGH AND WEAK SURFACE COLD FRONT
MOVING THROUGH THE REGION. MOST OF THE SCATTERED RAIN SHOWER
ACTIVITY TIED TO THIS MID-LEVEL TROUGH AND FRONT WAS NOW OVER
CENTRAL AND EASTERN WI WITH MID-CLOUD LINGERING ACROSS THE REST OF
THE AREA. SIGNAL IS SHOWING UP TONIGHT FOR STRATUS/FOG POTENTIAL
GIVEN WEAK PRESSURE GRADIENT/LIGHT WINDS AND FAIRLY MOIST LOWER
BOUNDARY LAYER FROM TODAYS SCATTERED RAINFALL. HAVE INCLUDED IFR
STRATUS AT KLSE FROM 06-09Z. NOT AS CONFIDENT AT KRST THOUGH WHERE
LIGHT NORTHWEST WINDS AFTER 06Z AND LACK OF RAINFALL/DRIER LOWER
BOUNDARY LAYER MAY PREVENT WIDESPREAD DEVELOPMENT. THIS WILL HAVE
TO BE MONITORED CLOSELY. LOOKING FOR IMPROVING/VFR CONDITIONS BY
LATE TUESDAY MORNING AS DRIER AIR SPREADS INTO THE AREA.
&&
.CLIMATE...
200 AM CST SUN NOV 18 2012
RECORD HIGH TEMPERATURES FOR WEDNESDAY/21ST AND THURSDAY/22ND. COOP
SITES ARE 6AM-6AM HIGHS...THUS 22ND HIGHS ARE 21.12Z TO 22.12Z. LA
CROSSE AND ROCHESTER ARE ONLY NON-COOP SITES.
FORECAST HIGH TEMPERATURES SUGGEST SOME OF THE RECORDS BELOW MAY
BE TIED OR BROKEN.
LOCATION WEDNESDAY/21ST THURSDAY/22ND
LA CROSSE WI 72/1990 59/1963
SPARTA WI 65/1990 70/1990
MEDFORD WI 59/1913 65/1990
LANCASTER WI 66/2003 66/1898
MAUSTON WI 67/2003 66/1990
ROCHESTER MN 69/1990 65/1913
AUSTIN MN 70/1990 58/1966
WINONA DAM 5A MN 60/2003 60/2001
WABASHA MN 61/1908 59/1908
CHARLES CITY IA 71/1990 62/1966
OELWEIN IA 71/1990 62/1966
DECORAH IA 71/1990 62/1908
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
200 AM CST MON NOV 19 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...DAS
CLIMATE......JONES/DB/AJ
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1025 AM CST MON NOV 19 2012
.UPDATE...MAIN CONCERNS TODAY ARE WX/POPS AND TEMPERATURES. S/W
TROUGH IS EVIDENT IN THE WV LOOP PUSHING THROUGH NORTHERN KS. VIS
SAT SHOWING OVERCAST SKIES WITH A FEW BREAKS...PRETTY RAGGED CLOUD
ELEMENTS. SFC MAP IS SHOWING CLOUD BASES AROUND 100 HFT...WITH
ONLY LONE ROCK IN S WI WITH A REPORT OF PRECIP...WITH A TRACE.
KMKX RADAR AND MOSAIC SHOWING LIGHT RETURNS ACROSS PORTIONS OF THE
WEST HALF OF CENTRAL AND SOUTHERN WI...THAT ARE GENERALLY AROUND
15-20 DBZ WITH HIGHER VALUES IN THE MID 20S TO 30S IN THE FAR NW
OF THE CWA AND OUTSIDE THE CWA. UPSTREAM AND SOUTH IN WESTERN
IL...RADAR RETURNS ARE STRONGER...AND ARE LIKELY WHAT COULD BE THE
BEST CHANCE FOR MEASURABLE PRECIP LATER TODAY.
WITH THE HIGH CLOUD BASES AND DRY AIR IN PLACE...THE LATTER VERY
NOTICEABLE FROM 850 HPA ISODROSOTHERM ANALYSES AND BUFKIT MODEL
SOUNDINGS...MOST OF THE RETURNS ARE LIKELY ASSOCIATED WITH VIRGA
INSTEAD OF PRECIP. 12 UTC DVN SOUNDING PROVIDES FURTHER EVIDENCE OF
THE DRY AIR IN PLACE...WITH DRY AIR/LOW RH IN PLACE FROM 700 HPA ON
DOWN AND PWAT OF .39 INCHES.
850-300 HPA MEAN FLOW IS OUT OF THE SOUTHWEST...WITH THE CURRENT
TRACK OF PRECIP UPSTREAM APPEARING TO BE HEADING FOR SOUTH OF
MADISON AND MORE TOWARDS THE SE OF THE CWA. LATEST HI-RES MODEL
REFLECTIVITY FIELDS...LOCAL WRF AND HRRR...ALTHOUGH MATCH WELL WITH
REFLECTIVITY UPSTREAM...NOT SO MUCH WITH WHATS OCCURRING IN THE
CWA. HRRR DEPICTS SHOWERY AND VERY LIGHT PRECIP BEGINNING THIS
AFTERNOON WITH A BREAK OCCURRING NOW UNTIL THEN...AFTER 21 UTC. THIS
COINCIDES WELL WITH CURRENT THINKING...AFTER LOOKING AT THE LATEST
RADAR TRENDS AND MODEL SOUNDINGS. THUS LOWERED POPS THIS AFTERNOON
TILL 21 UTC...WITH THE MAIN ISSUE WHETHER TO GO WITH DRIZZLE MENTION
WITH A SLIGHT CHANCE OF MEASURABLE PRECIP AT THE MOMENT.
HIGHS WERE LEFT AS IS. WILL BE TRICKY...IF SOME SUN CAN BREAK
THROUGH/HOLES APPEAR. NOT MUCH CONFIDENCE AT THE MOMENT. SO LEFT AS
IS AND WILL WAIT A BIT MORE TO ASSESS SKY AND TEMP TRENDS.
&&
.AVIATION/18Z TAFS/...MAY SEE A SHOWER OR SPRINKLE THROUGH THE
REMAINDER OF THE DAY...BUT OTHERWISE WILL JUST BE BKN TO OVC MID
AND HIGH LEVEL CLOUDS. WILL SEE AN INCREASE IN LOW LEVEL MOISTURE
LATE AFTERNOON AND EVENING...SO SOME MVFR CIGS POSSIBLE FOR A TIME
AFTER 00Z. WILL CONSIDER ADDING INTO NEXT TAF PACKAGE. COULD BE A
FEW SHOWERS/SPRINKLES TONIGHT TOO...OR MAYBE DRIZZLE. SOUNDINGS
GET PRETTY SATURATED IN THE LOWEST LEVELS AFTER MIDNIGHT...SO MAY
SEE SOME LOWER VSBYS AS WELL. WILL AT LEAST MAINTAIN MVFR VSBYS
IN TAFS AND CONSIDER GOING LOWER.
MODEL SOUNDINGS AND TIME HEIGHTS SHOW THAT DRIER AIR WILL BE SLOW
TO MOVE IN TOMORROW...SO COULD HOLD ONTO SOME LOWER CIGS THROUGH
AT LEAST THE MORNING...MAYBE EVEN THE AFTERNOON IN THE EAST.
&&
.PREV DISCUSSION... /ISSUED 330 AM CST MON NOV 19 2012/
TODAY AND TONIGHT...FORECAST CONFIDENCE IS MEDIUM TO HIGH
COOLEST CLOUD TOPS OVER CENTRAL IOWA INTO NRN MO ON IR SATELLITE
LOOPS IN REGION OF BEST LIFT AHEAD OF SHORT WAVE OVER ERN
NEB/KS...THAT MODELS WEAKEN ALONG WITH THE 250 MB JET-LET DRIVING
THIS VORT AS IT LIFTS TO THE NORTHEAST. PLENTY OF SCATTERED LIGHT
RETURNS OVER SW WI AND WRN IL ON REGIONAL RADARS...BUT MAINLY TIED
TO ISENTROPIC LIFT AT/ABOVE 700 MB WITH NO SURFACE REPORTS UNDER
7K TO 10K FT CEILINGS. INITIAL ISENTROPIC LIFT ONLY SATURATES
COLUMN DOWN TO AROUND 700 MB...WITH DRY AIR HOLDING IN BELOW INTO
THE EARLY AFTERNOON PER MODEL FORECAST SOUNDINGS AND TIGHT 850 MB
DEW POINT GRADIENT ON MODELS OVER CENTRAL WI AT 18Z.
LOCATIONS CURRENTLY REPORTING PRECIPITATION AT THE SURFACE FARTHER
TO THE SOUTHWEST IN LINE WITH NARROW CHANNEL OF DEEPER MOISTURE
AND STRONGER 700 MB OMEGA WITH BETTER LAYER Q-VECTOR CONVERGENCE
AHEAD OF DEVELOPING BROAD MID LEVEL TROUGH THAT CROSSES SOUTHERN
WI TODAY INTO THIS EVENING....WITH BEST LIFT EAST OF THE STATE
AROUND 06Z TUE ON EASTERN FLANK OF BROAD MID-LEVEL TROUGH.
THUS MOST OF SOUTHERN WI CLOUDY BUT DRY THROUGH THE
MORNING...EXCEPT IN THE FAR WEST WHICH RAPID UPDATE/HI RES MODELS
CLIP WITH CURRENT BAND OF SHOWERS IN EASTERN IOWA WHERE BETTER
LAYER FRONTOGENETIC FORCING LIFTS THROUGH FROM SOUTHWEST TO
NORTHWEST THIS MORNING INTO EARLY THIS AFTERNOON.
WILL TIME GENERALLY ISOLATED LIGHT RAIN SHOWERS/SCATTERED
SPRINKLES WITH LAYER Q-VECTOR CONVERGENCE AND 700 MB OMEGA. WILL
ALSO CARRY ISOLATED SPRINKLES AFTER MIDNIGHT IN THE FAR EAST WITH
WEAK FORCING AHEAD OF SURFACE TROUGH.
WENT WITH A CONSENSUS BLEND FOR TEMPERATURES WHICH LEAN TOWARD
PREVIOUS FORECAST...AND BETWEEN MAV/MET NUMBERS. CLOUDS AND
EVENTUAL LIGHT PRECIPITATION WILL PREVENT REACHING WARM MET
NUMBERS...BUT RELATIVELY WARM START TO THE DAY SHOULD ALLOW
SURFACE TEMPERATURES TO REACH THE MID 50S.
TUESDAY THROUGH WEDNESDAY NIGHT...FORECAST CONFIDENCE IS HIGH.
SHORT TERM MODELS SHOWING 500MB SHORTWAVE TROUGH SLIDING
SOUTHEAST ACROSS THE AREA MAINLY TUESDAY MORNING...WITH THE NAM
SLOWER AND BRINGING IT THROUGH IN THE AFTERNOON. WEAK SURFACE COLD
FRONT MOVES EAST THROUGH THE AREA TUESDAY MORNING. AREA FORECAST
SOUNDINGS SHOWING SOME MOISTURE IN THE LOWER LEVELS DURING THE
MORNING...MORE SO ON THE GFS THAN THE NAM. BOTH HAD THE MID TO
UPPER LEVELS DRY.
GIVEN THE WEAK UPWARD VERTICAL MOTION FIELDS IN THE AREA WITH
THESE FEATURES...WILL KEEP FORECAST DRY TUESDAY. HIGHS WILL REMAIN
MILD...INTO THE MID 50S PER NAM 925MB TEMPERATURES AND EXPECTED
MIXING TO THAT LEVEL.
500MB RIDGE AXIS THEN SLIDES SOUTHEAST ACROSS THE REGION TUESDAY
NIGHT AND WEDNESDAY...THEN TO THE SOUTHEAST WEDNESDAY NIGHT.
SURFACE HIGH PRESSURE SLOWLY SLIDES SOUTHEAST DURING THIS TIME AS
WELL...WITH SOUTH WINDS GRADUALLY INCREASING. PATCHY FOG IS
EXPECTED TUESDAY NIGHT...WITH LIGHT WINDS AND CLEAR SKIES WITH
RADIATIONAL COOLING.
WARM AIR ADVECTION KICKS IN TUESDAY NIGHT AND WEDNESDAY...WHICH
SHOULD BRING 925MB TEMPERATURES INTO THE 8 TO 11 DEGREE CELSIUS
RANGE PER NAM. SHOULD SEE HIGHS REACH THE UPPER 50S TO LOWER
60S...DEPENDING ON IF MIXING REACHES THE 925MB LEVEL. LOWS IN THE
30S TUESDAY NIGHT SHOULD WARM INTO THE LOWER TO MID 40S WEDNESDAY
NIGHT.
THANKSGIVING DAY THROUGH SUNDAY...FORECAST CONFIDENCE IS MEDIUM.
GFS/ECMWF SHOWING SOME DIFFERENCES WITH FEATURES DURING THIS
PERIOD. THE GFS AND ECMWF BOTH NOW HAVE MORE QPF ACROSS THE AREA
IN THE AFTERNOON THANKSGIVING DAY...AS A STRONG COLD FRONT MOVES
TOWARD THE AREA. THE FRONT MOVES THROUGH THE AREA THURSDAY
EVENING...AND EXITS LATER IN THE NIGHT.
A STRONG SHORTWAVE TROUGH AT 500MB THEN MOVES THROUGH THE
AREA...ABOUT 6 HOURS QUICKER ON THE GFS THAN THE ECMWF. SECONDARY
SHORTWAVE THEN MOVES SOUTHEAST THROUGH THE AREA FRIDAY ON BOTH
MODELS. ECMWF KEEPS 500MB CYCLONIC FLOW IN THE AREA FRIDAY NIGHT
INTO EARLY SATURDAY...WITH THE GFS ALREADY OUT OF THE REGION.
AREA FORECAST SOUNDINGS FROM THE GFS SHOW MODEST MOISTURE IN THE
AIR COLUMN...WITH WEAK TO MODEST UPWARD VERTICAL MOTION. FOR
NOW...WILL ADD SLIGHT CHANCE POPS FOR LIGHT RAIN SHOWERS
THANKSGIVING DAY...LINGERING IN THE FAR SOUTHEAST THURSDAY NIGHT.
MILD TEMPERATURES WILL CONTINUE THANKSGIVING DAY...BEFORE STRONG
COLD AIR ADVECTION BEHIND THE FRONT KICKS IN THURSDAY NIGHT AND
FRIDAY FROM BOTH THE GFS AND ECMWF. THIS SHOULD BRING COOLER
TEMPERATURES TO THE AREA.
THE GFS CONTINUES TO BE QUICKER WITH FEATURES THAN THE ECMWF
SATURDAY INTO SUNDAY. THE GFS HAS WARM AIR ADVECTION DEVELOPING
SATURDAY INTO SUNDAY...WITH THE ECMWF HOLDING OFF UNTIL SATURDAY
NIGHT AND SUNDAY. KEPT THIS PERIOD DRY...WITH LACK OF DEEP
MOISTURE IN GFS FORECAST SOUNDINGS ACROSS THE AREA. COOL
TEMPERATURES SHOULD CONTINUE DURING THIS TIME.
AVIATION/12Z TAFS/...EXPECT VFR CIGS AND VSBYS FOR MOST OF THE
PERIOD...WITH BIGGEST QUESTION HOW HARD TO HIT PRECIPITATION.
INITIALLY...BEST CHANCE TO SEE PRECIP WILL BE AT KMSN AROUND MID-
MORNING IF CURRENT BAND OF SHOWERS IN EASTERN IOWA HOLDS TOGETHER.
MOST OF THE RAPID UPDATE MODELS KILL THIS PRECIP OFF...WITH WIDELY
SCATTERED LIGHT SHOWERS/SPRINKLES AHEAD OF MID-LEVEL TROUGH THIS
AFTERNOON AND EVENING. WILL KEEP VICINITY SHOWERS FOR MOST LIKELY
PERIODS...WITH VFR CIGS AND VSBYS. MAV GUIDANCE WANTS TO LOWER
CIGS TO MVFR BEHIND THE SURFACE TROUGH...WITH NAM INDICATING SOME
POTENTIAL FOR MVFR VSBYS IN FOG. WILL LEAVE OUT FOR NOW AND AWAIT
UPSTREAM INDICATORS.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...ET/DDV
TODAY/TONIGHT AND AVIATION/MARINE...REM
TUESDAY THROUGH SUNDAY...WOOD