Forecast Discussions mentioning any of
"HRRR" "RR" "RUC13" "RUC" received at GSD on 12/12/11
AREA FORECAST DISCUSSION
NWS DENVER CO
902 PM MST SUN DEC 11 2011
.UPDATE...NO CHANGES TO THE ONGOING FORECAST AT THIS TIME.
&&
.AVIATION...NO BIG ADJUSTMENTS EXPECTED IN THE NEXT TAF ISSUANCE.
THE RUC INDICATES A NORTHERLY WIND SHIFT AROUND 12Z AS A FRONT
SLOWLY BACKDOORS ITS WAY INTO THE AREA MONDAY SO THAT WILL NEED TO
BE ADDRESSED AT 06Z.
&&
.PREV DISCUSSION... /ISSUED 300 PM MST SUN DEC 11 2011/
SHORT TERM...TODAY THE LEE TROUGH HAS HELPED BOOST TEMPERATURES
INTO THE 40S OVER MOST OF EASTERN COLORADO. THIS LEE TROUGH WILL BE
SLIDING EAST TOMORROW...AND HIGH PRESSURE WILL BE SLIDING ACROSS THE
HIGH PLAINS. AS A RESULT TEMPERATURES WILL BE A FEW DEGREES COOLER
ON MONDAY OVER THE PLAINS. ALOFT WE HAVE A WEAK RIDGE ALOFT TODAY
WHICH SLIDES EAST MONDAY AS A STRENGTHENING SOUTHWEST FLOW ALOFT
MOVES INTO THE STATE. AHEAD OF AN UPPER LOW ON THE COAST OF
SOUTHERN CALIFORNIA...MOISTURE WILL BEGIN TO SPREAD INTO THE
SOUTHWESTERN PART OF COLORADO ON MONDAY...BUT NOT REACH OUR AREA.
WE EXPECT JUST AN INCREASE IN HIGH LEVEL MOISTURE.
LONG TERM...MODELS CONTINUE TO SLOW THE EASTWARD PROGRESSION OF THE
NEXT UPPER TROUGH. THEY SHOW INCREASING SOUTHWESTERLY FLOW ALOFT
OVER THE CWA MONDAY NIGHT. STRONG SOUTHWESTERLY FLOW ALOFT IS IN
PLACE ALL DAY TUESDAY. THIS GRADUALLY DECREASES TUESDAY NIGHT INTO
WEDNESDAY...WITH THE UPPER TROUGH AXIS LOCATED FROM THE SOUTHWEST
CORNER OF COLORADO TO THE NORTHEAST CORNER AT 00Z LATE WEDNESDAY
AFTERNOON. WEAK NORTHWESTERLY FLOW ALOFT MOVES INTO THE FORECAST
AREA WEDNESDAY NIGHT. FOR THE MOST PART...WEAK UPWARD QG VERTICAL
VELOCITY IS PROGGED FOR THE CWA MONDAY NIGHT THROUGH MID DAY
WEDNESDAY. THE UPWARD MOTION GETS A BIT STRONGER OVER THE EAST AND
SOUTHEAST FORECAST AREA WEDNESDAY MORNING. THE PROGGED BOUNDARY
LAYER FLOW IS FAIRLY WEAK AND SOUTHEASTERLY FOR THE PLAINS AND LOWER
FOOTHILLS. ON TUESDAY...THE ONLY DECENT BOUNDARY LAYER FLOW IS
PROGGED OVER THE EASTERN BORDER...WHERE SOUTHEASTERLIES ARE
PROGGED. THE REST OF THE CWA HAS BENIGN LOW LEVEL FLOW. FAIRLY
WEAK FLOW CONTINUES TUESDAY NIGHT INTO WEDNESDAY...THEN
NORTHWESTERLY DOWNSLOPING KICKS IN WEDNESDAY AFTERNOON INTO THE
EVENING. FOR MOISTURE...MODELS HAVE IT INCREASING MONDAY NIGHT...
WITH CONSIDERABLY MORE INDICATED ON THE NAM. ON TUESDAY...THE NAM
HAS DEEP MOISTURE IN PLACE OVER MUCH OF THE CWA...THE LEAST OVER THE
FAR WEST. ON THE OTHER HAND...THE GFS IS WAY DRIER...ESPECIALLY IN
THE LOWER AND MID LAYERS OF ALL THE FORECAST AREA. BY TUESDAY NIGHT
..THE TWO MODELS GET INTO BETTER AGREEMENT WITH MOISTURE...THE EAST
DRYING OUT AND MOISTURE DEEPENING OVER THE MOUNTAINS AS THE TROUGH
AXIS NEARS. ON WEDNESDAY...THE EAST IS FAIRLY DRY...WITH SOME
MOISTURE OVER THE MOUNTAINS...IT`S NOT REALLY DEEP. THE ECMWF
MOISTURE SOLUTIONS LOOK MORE LIKE THE GFS`. THE QPF FIELDS HAVE NO
MEASURABLE PRECIPITATION OVER THE CWA MONDAY NIGHT. ON TUESDAY...
THE NAM HAS DECENT AMOUNTS...ESPECIALLY OVER THE SOUTH AND SOUTHEAST
FORECAST AREAS. THE GFS HAS BARELY ANY. THE NAM HAS A TAD TUESDAY
NIGHT...NOTHING ON THE GFS. FOR WEDNESDAY...BOTH HAVE A TAD IN THE
MOUNTAINS WEST OF THE DIVIDE. SO FOR POPS ON TUESDAY OVER THE
PLAINS...THERE IS A BIT OF A JET MAX AROUND TUESDAY...SOME UPWARD
SYNOPTIC SCALE ENERGY...AND A LOT OF MOISTURE (AT LEAST ON ONE OF
THE MODELS)...SO WILL GO WITH 10-20%S FOR THE WESTERN PLAINS. WILL
GO WITH 30%S OVER THE SOUTHEAST AND EASTERN BORDER PLAINS. WILL GO
WITH FREEZING DRIZZLE OVER THE NORTHEAST CORNER...SOUNDINGS POINT TO
THAT POSSIBILITY. WILL GO WITH "SLIGHT CHANCE" IN THE MOUNTAINS
TUESDAY. WILL UP POPS TO 30%S IN THE MOUNTAINS TUESDAY NIGHT AND
WEDNESDAY...MOISTURE IS A BIT BETTER...AND HELP FROM OROGRAPHICS
LOOKS A TAD BETTER. FOR TEMPERATURES...TUESDAY`S HIGHS ARE CLOSE TO
MONDAY`S. WEDNESDAY`S HIGHS ARE 1-2 C WARMER. FOR THE LATER DAYS
..THURSDAY THROUGH SUNDAY...MODELS HAVE THE FLOW ALOFT BECOMING
ZONAL ON THURSDAY...THEN STRONG SOUTHWESTERLY ON FRIDAY WITH THE
NEXT UPPER TROUGH AXIS OVER WESTERN COLORADO BY 00Z LATE FRIDAY.
MODEL SHOW THE UPPER TROUGH WEAKENING AND MOVING LITTLE THROUGH THE
DAY SATURDAY...WITH AN UPPER CLOSED LOW SOMEWHERE FROM THE NORTHERN
BAJA CALIFORNIA COAST TO SOUTH OF THE FOUR CORNERS. THE GFS BRINGS
WHAT`S LEFT OF THE UPPER TROUGH ACROSS THE CWA ON SUNDAY...THE ECMWF
DOESN`T EVEN HAVE A TROUGH TO PUSH ACROSS US. HARD TO SAY AT THIS
TIME WHAT IT WILL ALL LOOK LIKE. THE CREXTENDEDFCST_INIT GRIDS ON
GFE SHOW MINIMAL POPS FOR THE CWA WITH THIS SYSTEM...SO THE
UNCERTAINTY IS FORECAST PRETTY WELL. TEMPERATURES DON`T LOOK LIKE
THEY WILL GET ABOVE SEASONAL NORMALS THROUGH THE PERIOD.
$$
AVIATION...DRY VFR CONDITIONS WILL CONTINUE THROUGH MONDAY. LIGHT
DRAINAGE WINDS TONIGHT WILL BECOME LIGHT EAST OR SOUTHEAST WINDS
MONDAY AFTTERNOON.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...99
LONG TERM....99
AVIATION...99
AREA FORECAST DISCUSSION
NWS PUEBLO CO
306 PM MST SAT DEC 10 2011
.SHORT TERM...
(TONIGHT AND SUNDAY)
WE WILL CONTINUE TO SEE CLEAR SKIES TONIGHT. THE FLOW ALOFT TONIGHT
IS EXPECTED TO BECOME MORE WESTERLY WITH A LEE SFC TROF DEVELOPING.
THE WESTERLY WINDS NEAR THE MTS SHOULD KEEP TEMPS A BIT WARMER THAN
THEY WERE LAST NIGHT. TEMPS OVR THE SERN PLAINS WL ALSO BE A LITTLE
WARMER MOST AREAS. THE SAN LUIS VALLEY HOWEVER SHOULD STILL SEE
SINGLE DIGITS ABOVE AND BELOW ZERO FOR LOW TEMPS TONIGHT. THE NAM
BUFKIT SOUNDING FOR KALS SHOWS THE POTENTIAL FOR STRATUS AND FOG
DEVELOPING. WE DIDN`T SEE THAT HAPPEN THIS MORNING AND I HAVE LOW
CONFIDENCE THAT IT WILL HAPPEN TONIGHT. THE RUC AND NAM SOUNDINGS
FOR KLHX AND KLAA ALSO SHOW THE POTENTIAL FOR STRATUS/FOG DEVELOPING
AGAIN. I AM NOT REAL CONFIDENT IN THIS EITHER. SO FOR NOW WL LEAVE
OUT THE MENTION OF CLOUDS AND/OR FOG.
ANOTHER DRY DAY IS EXPECTED SUNDAY WITH BEING A LITTLE WARMER THAN
TODAY IN MOST AREAS...ALTHOUGH THE SAN LUIS VALLEY MAY SEE SIMILAR
OR JUST SLIGHTLY WARMER TEMPS THAN TODAY. THE NAM IS SHOWING LOW
LEVEL MOISTURE WORKING ITS WAY NORTHWARD SUNDAY AFTERNOON...AND INTO
THE FAR SERN CORNER OF THE STATE (MOSTLY BACA COUNTY)...SO WE WL
PROBABLY SEE AN INCREASE IN CLOUDS OVR THAT AREA.
.LONG TERM...
(SUNDAY NIGHT THROUGH SATURDAY)
METEOROLOGICAL ISSUES THIS LONGER TERM CYCLE INCLUDE BUT ARE NOT
LIMITED TO POPS...POTENTIAL SNOW AMOUNTS(ESPECIALLY OVER SECTIONS
OF THE CENTRAL AND SOUTHWESTERN MOUNTAINS)...GUSTY WINDS AT TIMES
AND TEMPERATURES.
RECENT LONGER TERM MODEL SOLUTIONS SUGGEST THAT THE DRY SOUTHWEST
UPPER FLOW OF SUNDAY NIGHT INTO AT LEAST EARLY MONDAY AFTERNOON
WILL GIVE WAY TO INCREASING PRECIPITATION CHANCES(AS CLOSED UPPER
LOW DEVELOPS OVER FAR SOUTHERN CALIFORNIA BY 06Z TUESDAY AND THEN
MOVES INTO THE 4-CORNERS REGION BY TUESDAY NIGHT) FROM LATER
MONDAY AFTERNOON INTO AT LEAST TUESDAY EVENING(ESPECIALLY OVER
ZONE 68/EASTERN SAN JUAN MOUNTAINS WHERE LATEST MODEL PROJECTIONS
INDICATE THAT SNOW AMOUNTS IN EXCESS OF 12 INCHES MAY OCCUR FROM
MONDAY NIGHT INTO TUESDAY...I.E. MY 5TH AND 6TH PERIODS).
AT THIS TIME...WILL HOLD OFF ON ANY WINTER HIGHLIGHTS FOR NOW SINCE
EVENT IS STILL A BIT TOO FAR OUT IN TIME...HOWEVER IF LATEST
COMPUTER MODEL TRENDS PERSIST...WFO PUEBLO WILL LIKELY BE ISSUING
WINTER WEATHER HIGHLIGHTS...ESPECIALLY FOR AREAS SUCH AS ZONE 68
DURING THE NEXT DAY OR TWO...PLEASE STAY TUNED.
ELSEWHERE...AS INITIAL UPPER SYSTEM PUSHES ACROSS THE REGION FROM
TUESDAY NIGHT INTO WEDNESDAY...ANTICIPATE INCREASED CLOUD/SHOWER
ACTIVITY IN COMBINATION WITH COOLER TEMPERATURES.
FORECAST DISTRICT THEN RECEIVES A BRIEF RESPITE THURSDAY BEFORE NEXT
CLOSED LOW TRAVELS FROM THE PACIFIC NORTHWEST ON THURSDAY AND
SETTLES OVER FAR SOUTHERN CALIFORNIA FROM FRIDAY EVENING INTO
SATURDAY.
THIS NEXT UPPER SYSTEM SHOULD AGAIN IMPACT WESTERN AND NORTHERN
PORTIONS OF THE CWFA WITH UNSETTLED CONDITIONS FROM LATER THURSDAY
INTO AT LEAST FRIDAY...ALTHOUGH PRIMARY PRECIPITATION FOCUS WITH
THIS SYSTEM APPEARS TO REMAIN WELL SOUTH THROUGH SOUTHWEST OF THE
CWFA DURING THIS TIME-FRAME.
IN ADDITION...TEMPERATURES GENERALLY RUNNING NEAR OR BELOW MID-DECEMBER
SEASONAL AVERAGES ARE ANTICIPATED DURING THE LONGER TERM.
FINALLY...GUSTY WINDS WILL BE POSSIBLE AT TIMES FROM TUESDAY INTO
TUESDAY NIGHT AND THEN AGAIN BY NEXT FRIDAY(ESPECIALLY EASTERN
SECTIONS).
&&
.AVIATION...
EXPECT VFR CONDITIONS FOR THE NEXT 24 HOURS AT KCOS AND KPUB. KALS
WL LIKELY HAVE VFR CONDITIONS DURING THIS PERIOD AS WELL...HOWEVER
ONE MODEL SOUNDING IS SHOWING THE POTENTIAL FOR THE DEVELOPMENT OF
STRATUS/FOG TONIGHT. SINCE IT DIDN`T HAPPEN THIS MORNING AND THE
MODEL HAD FORECAST IT YESTERDAY...MY CONFIDENCE IN THE STATUS/FOG
DEVELOPING IS LOW AND WL LEAVE IT OUT OF THE TAF.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1047 PM MST FRI DEC 9 2011
.AVIATION...
WESTWARD EXTENT OF STRATUS AND FOG AGAIN THE CONCERN
OVERNIGHT...ESPECIALLY ACROSS THE LOWER ARKANSAS VALLEY.
PERSISTENT AREA OF STRATUS AND FOG FROM JUST EAST OF KPUB THROUGH
KLHX AND KLAA HAS SHOWN VERY LITTLE WESTWARD MOTION SO
FAR...THOUGH AREAL COVERAGE OF STRATUS HAS EXPANDED SLIGHTLY NEAR
THE KS BORDER. LATEST RUC SUGGESTS FOG/STRATUS AREA WILL REMAIN
RELATIVELY UNCHANGED THROUGH SATURDAY MORNING...WHILE HRRR SNEAKS
A NARROW RIBBON OF FOG WESTWARD ALONG THE ARKANSAS THROUGH PUEBLO
COUNTY AFTER 09Z. THUS FOR THE KPUB TAF...BACKED OFF THE ONSET OF
IFR/LIFR CONDITIONS UNTIL 10Z...THEN KEPT ONLY A BRIEF PERIOD OF
IFR CIGS IN THE 10Z-14Z PERIOD BEFORE IMPROVING TO VFR BY 16Z. AT
KALS...GIVEN LITTLE CHANGE FROM LAST NIGHTS CONDITIONS...SUSPECT
AT LEAST SOME SHALLOW DENSE FOG IS LIKELY NEAR THE TERMINAL BY
SUNRISE...AND THUS KEPT A BRIEF PERIOD OF LIFR HERE FROM 09Z-15Z
BEFORE IMPROVING. KCOS SHOULD STAY OUT OF THE FOG/CLOUDS AND
REMAIN VFR OVERNIGHT INTO SAT MORNING. EXPECT FOG TO LIFT ALL
AREAS BY MIDDAY SAT...WITH VFR CONDITIONS INTO SAT NIGHT.
--PETERSEN
&&
.PREV DISCUSSION... /ISSUED 612 PM MST FRI DEC 9 2011/
UPDATE...
WILL BE UPDATING MOST GRIDS/PRODUCTS TO ADD MENTION OF FOG FOR THE
REST OF THE NIGHT ALONG THE ARKANSAS RIVER FROM PUEBLO
EASTWARD...AS VISIBILITY HAS DROPPED TO AROUND A QUARTER MILE AT
BOTH LAMAR AND LA JUNTA. MAY EVENTUALLY NEED A DENSE FOG ADVISORY
FOR A FEW HOURS...THOUGH WILL WAIT TO SEE HOW FAR WEST FOG/STRATUS
DEVELOPS OVER THE NEXT 1-2 HOURS BEFORE ISSUING ANYTHING. ALSO
ADDED A MENTION OF FOG TO PORTIONS OF THE SAN LUIS VALLEY LATE
TONIGHT...AS ANOTHER ROUND OF DENSE FOG IS POSSIBLE AROUND SUNRISE
ALONG THE RIO GRANDE FROM ALAMOSA SOUTHWARD. --10
PREV DISCUSSION... /ISSUED 313 PM MST FRI DEC 9 2011/
SHORT TERM...
(TONIGHT AND SATURDAY)
SOME LOW CLOUDS HAVE REMAINED OVR THE LOWER ARKANSAS RIVER VALLEY
THRU THE DAY...EAST OF PUEBLO TO THE KANSAS BORDER. AS A
RESULT...TEMPS HAVE BEEN ONLY IN THE 20S.
NW FLOW ALOFT WL REMAIN OVR THE AREA TONIGHT AND SATURDAY...WITH A
WEAK SHORTWAVE TROF MOVING THRU THE AREA ON SATURDAY.
TONIGHT...ALTHOUGH THE AREA OF STRATUS OVR THE SERN PLAINS HAS BEEN
SLOWLY SHRINKING...IT LOOKS LIKE IT WL PROBABLY EXPAND AGAIN AS WE
WL AGAIN SEE AREAS OF STRATUS ACRS PORTIONS OF THE SERN PLAINS ONCE
THE SUN GOES DOWN AND TEMPS COOL. THE SAN LUIS VALLEY SHOULD ALSO
SEE AREAS OF LOW CLOUDS/FOG DEVELOP AGAIN.
TEMPS ALOFT ARE EXPECTED TO WARM A COUPLE OR A FEW DEGREES ON
SATURDAY AND WE SHOULD GENERALLY SEE WARMER TEMPS THAN TODAY...WITH
THE MOST NOTICEABLE CHANGES BEING OVR THE SOUTHEAST PLAINS.
OTHERWISE...THE WEATHER WILL REMAIN DRY WITH GENERALLY LIGHT WINDS.
LONG TERM...
(SATURDAY NIGHT THROUGH FRIDAY)
QUIET METEOROLOGICAL PATTERN TO CONTINUE OVER THE FORECAST DISTRICT
INTO AT LEAST MONDAY EVENING WITH MORE ACTIVE UNSETTLED CONDITIONS
RETURNING TO THE REGION AT TIMES FROM TUESDAY INTO LATE WEEK.
LATEST COMPUTER PROJECTIONS CONTINUE TO INDICATE THAT DRY
UPPER RIDGING PERSISTS INTO SATURDAY EVENING. DRY ZONAL TO
SOUTHWESTERLY UPPER FLOW SHOULD BE THEN BE NOTED OVER THE CWFA
FROM LATER SATURDAY EVENING INTO MONDAY EVENING IN ADVANCE OF
CLOSED UPPER LOW INITIALLY CENTERED OVER SOUTHERN CALIFORNIA AT
18Z TUESDAY. THIS UPPER SYSTEM THEN ROTATES ACROSS THE FORECAST
DISTRICT FROM TUESDAY INTO WEDNESDAY PROVIDING UNSETTLED AND
COOLER CONDITIONS DURING THIS TIME-FRAME.
ANOTHER UPPER SYSTEM IS PROJECTED TO IMPACT THE FORECAST DISTRICT BY
LATE WEEK ALLOWING BELOW SEASONAL COOL MID-DECEMBER TEMPERATURES AND
UNSETTLED CONDITIONS TO CONTINUE.
WARMEST TEMPERATURES OF THE LONGER TERM ARE STILL ANTICIPATED FROM
THIS WEEKEND INTO MONDAY WITH BELOW SEASONAL TEMPERATURES THEN
RETURNING TO THE CWFA DURING THE REMAINDER OF NEXT WEEK.
ALSO...GUSTY WINDS ARE EXPECTED AT TIMES FROM MONDAY NIGHT INTO
THURSDAY...ESPECIALLY EASTERN SECTIONS.
AVIATION...
IFR CIGS AND VSBYS ARE EXPECTED TO DEVELOP AGAIN AT KALS
TONIGHT...PROBABLY AFTER 03Z AND DISSIPATING BY ABOUT 16Z. IT LOOKS
LIKE KCOS SHOULD CONTINUE TO HAVE CLEAR OR MOSTLY CLEAR SKIES AND
THUS VFR CONDITIONS TONIGHT AND SATURDAY. IT LOOKS LIKE KPUB WILL
SEE THE RETURN OF MVFR OR IFR CONDITIONS...PROBABLY AFTER 02Z. THERE
IS SOME INDICATION IN THE FORECAST MODEL THAT THE LOW CLOUDS WL
DISSIPATE AROUND 10Z AS SOME WEAK WESTERLY WINDS DEVELOP...WITH VFR
CONDITIONS RETURNING.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
10/44
AREA FORECAST DISCUSSION
NWS TOPEKA KS
613 PM CST SUN DEC 11 2011
...UPDATE TO AVIATION...
.DISCUSSION...
LATEST WATER VAPOR LOOP AT 20Z WAS SHOWING THE UPPER TROUGH MOVING
SLOWLY ACROSS THE HIGH PLAINS FROM NEBRASKA INTO THE TEXAS
PANHANDLE. SHOWERS HAVE DEVELOPED OUT AHEAD OF THE WAVE IN OKLAHOMA
TODAY AND HAVE BEEN MOVING NORTHEAST SLOWLY THROUGH THE DAY.
SOUNDING FROM 12Z AT TOP AND SGF SHOWED PLENTY OF DRY AIR OFF THE
DECK THIS MORNING. SOME DRY AIR CONTINUES TO BE ENTRAINED THIS
EVENING IN THE EASTERN CWA PER MODEL TIME SECTIONS. LATEST RUN OF
THE RUC DOES NOT BRING ANY MEASURABLE PRECIPITATION AS FAR NORTH
INTO THE SOUTHERN CWA TONIGHT. THE UPPER WAVE WILL MOVE SLOWLY MOVE
ACROSS THE CENTRAL PLAINS TONIGHT WITH THE UPPER TROUGH AXIS MOVING
THROUGH THE EASTERN CWA BY 09Z MONDAY. 925-850 MB WINDS BECOME SOUTH
EARLY THIS EVENING THEN SOUTHWEST OVERNIGHT AND BY MORNING WILL
FOCUS MOISTURE TO THE EAST. EXPECT CLOUDS TO REMAIN THROUGH THE
NIGHT WITH SOME PATCHY FOG AND DRIZZLE POSSIBLE IN THE NORTHWEST
WHILE SPRINKLES ARE MORE LIKELY IN THE EAST. LOWS TONIGHT WILL
REMAIN ABOVE FREEZING SO NO FREEZING OR FROZEN PRECIPITATION IS
EXPECTED.
MONDAY SOME EARLY MORNING PATCHY DRIZZLE OR FOG IS POSSIBLE OFF THE
SNOW PACK TO THE WEST IN NORTH CENTRAL KANSAS. BY MID MORNING A
FRONTAL BOUNDARY WILL APPROACH FROM THE WEST BUT MAKES SLOW PROGRESS
THROUGH THE DAY AND BECOMES STATIONARY FROM SOUTHEAST NEBRASKA INTO
SOUTHWEST KANSAS. SOUTHERLY FLOW AHEAD OF THE FRONT WILL BRING
TEMPERATURES AGAIN IN THE MID AND UPPER 40S TO THE AREA.
53
MODELS ARE SIMILAR IN TAKING UPPER TROUGH OFF THE SOUTHERN CA COAST
MONDAY EVENING AND EJECTING IT NORTHEASTWARD INTO THE CENTRAL HIGH
PLAINS BY MIDDAY WEDNESDAY...THEN RAPIDLY INTO THE WESTERN GREAT
LAKES BY LATE WEDNESDAY NIGHT. THE MODELS ARE IN LESS AGREEMENT ON
HOW FAR SOUTHEAST THE COLD FRONT WILL PUSH SOUTHEAST INTO THE
NORTHWEST COUNTY WARNING AREA (CWA) MONDAY NIGHT BEFORE
STALLING...WITH THE NAM/SREF THE MOST AGGRESSIVE INTO THE NORTHWEST
1/3 OF THE CWA AND THE GFS/EC NOT BRINGING IT INTO THE NORTHWEST
CORNER AT ALL. WILL COMPROMISE FOR NOW WITH SOME
FREEZING/SUBFREEZING TEMPS IN THE FAR NORTHWEST CORNER BEHIND THE
FRONT AND WARMER ABOVE FREEZING TEMPS ELSEWHERE. WITH A CHANCE FOR
DRIZZLE/LIGHT RAIN INCREASING LATER IN THE NIGHT AND NO NON DIURNAL
TREND EXPECTED...CANNOT RULE OUT A WINDOW FOR SOME LIGHT FREEZING
PRECIP IN THE FAR NORTHWEST CORNER OF THE CWA 06-12Z
TUES...OTHERWISE EXPECT THE PRECIP WITH THIS SYSTEM TO BE A RAIN
EVENT TUESDAY THROUGH WEDNESDAY BEFORE ENDING WEDNESDAY NIGHT.
ELEVATED INSTABILITY AND FORCING LOOK SUFFICIENT FOR SOME THUNDER
POTENTIAL AHEAD OF THE FRONT IN THE DEEPER MOISTURE AXIS ACROSS THE
SOUTHEAST HALF OF THE CWA WHERE THE WARMER MORNING LOWS WEDNESDAY
WILL BE IN THE LOW TO MID 40S. AFTER HIGHS IN THE LOW TO MID 40S ON
TUESDAY...SHOULD SEE HIGHS RISE INTO THE LOW TO MIDDLE 50S FOR
WEDNESDAY.
AFTER THIS SYSTEM EXITS...MODELS DIVERGE THROUGH THE END OF THE WEEK
AND INTO NEXT WEEKEND ON HOW QUICKLY THE NEXT SHORTWAVE TO DIG INTO
THE SOUTHWEST CONUS WILL EJECT OUT INTO THE PLAINS. THE ECMWF MODEL
IS ABOUT 2 DAYS SLOWER WITH ITS ARRIVAL AND ASSOCIATED PRECIP THAN
THE GFS. WITH SUCH LOW CONFIDENCE ON ITS ARRIVAL TIME AND CURRENT
DRY FCST THROUGH SATURDAY...OPTED TO KEEP FCST DRY UNTIL SATURDAY
NIGHT/SUNDAY WITH LOW CHANCES FOR RAIN/FREEZING RAIN OR A SNOW
POTENTIAL. AFTER LOWS IN THE 20S AND HIGHS IN THE 30S BOTH FRIDAY
AND SATURDAY...HIGHS TEMPS SHOULD SLOWLY MODERATE AHEAD OF THE NEXT
UPPER TROUGH INTO THE 40S FOR HIGHS ON SUNDAY. 63
&&
.AVIATION...
VFR CONDITIONS WILL CONTINUE THROUGH MOST OF THE OVERNIGHT HOURS
WITH BKN/OVC CEILINGS OF 4-6KFT. ACCOUNTED FOR POTENTIAL FOR BRIEF
PERIOD OF SPRINKLES OR LIGHT RAIN SHOWERS IMPACTING TOP/FOE
BETWEEN 02-05Z. OTHERWISE...EXPECT CEILINGS TO LOWER DURING THE
MORNING HOURS AND BECOME MVFR/NEAR MVFR FOR THE REMAINDER OF THE
PERIOD.
BLAIR
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
336 PM CST SAT DEC 10 2011
.DISCUSSION...
WATER VAPOR SHOWING UPPER LEVEL HIGH PRESSURE OVER THE ROCKIES WITH
DRY NORTHWEST FLOW ALOFT ACROSS THE COUNTY WARNING AREA (CWA). AS THE
RIDGE ADVANCES EASTWARD AND FLATTENS...THE FLOW ACROSS THE CWA WILL
BECOME MORE ZONAL. THIS WILL ALLOW LEESIDE SFC TROUGHING TO THE WEST
TO REMAIN IN PLACE AND KEEP SOUTH/SOUTHWESTERLY FLOW IN THE LOWER
LEVELS IN PLACE ACROSS THE CWA THROUGH SUNDAY. STRATUS DECK AT MID
AFTERNOON ACROSS PORTIONS OF CENTRAL/SOUTH CENTRAL KS CONTINUES TO
ERODE AND DO NOT EXPECT MUCH IF ANY OF IT TO MAKE IT INTO THE CWA
THIS AFTERNOON OR EVENING...ALTHOUGH THIS MOISTURE AXIS WILL REMAIN
IN PLACE AND BY SUNDAY AFTERNOON EXPECT MORE CLOUDS TO DEVELOP
ACROSS THE WESTERN CWA AS 850 DEWPOINTS STEADILY INCREASE WITHIN
THIS AXIS.
EXPECT MIXING TONIGHT TO BE AN OFFSETTING FACTOR FOR SIGNIFICANT FOG
TONIGHT...SO WILL LEAVE IT OUT OF GRIDS FOR NOW. WITH PERSISTENT
SOUTH/SOUTHWEST FLOW ON SUNDAY...WEAK WARM AIR ADVECTION AND MOSTLY
SUNNY SKIES THROUGH PEAK HEATING...MIDDLE TO UPPER 40S STILL LOOK ON
TARGET FOR THE CWA. 63
WARM MOIST ADVECTION BEGINS IN EARNEST SUNDAY NIGHT INTO FRIDAY
MORNING. THERE IS SOME WEAK ISENTROPIC LIFT ON THE 290K SURFACE
SUNDAY NIGHT INTO MONDAY MORNING. FORECAST SOUNDING SATURATE IN THE
LOWER LEVELS BUT LIFT IS MINIMAL. SOME SUPPORT FOR FORCING WILL COME
FROM A PASSING WAVE LATE SUNDAY NIGHT WHICH MAY SPIT OUT SOME LIGHT
RAIN IN THE NORTHEAST CORNER. FURTHER WEST SOUNDINGS A BIT MORE
FAVORABLE FOR SOME DRIZZLE AND FOG SO WILL MAINTAIN FROM PREVIOUS
FORECAST. MONDAY LOOKING MAINLY DRY AS THE UPPER WAVE MOVES OFF AND
850 MB FLOW BECOMES MORE SOUTHWESTERLY FOCUSING MOISTURE TO THE
NORTHEAST OF THE CWA HOWEVER COULD HAVE SOME EARLY MORNING DRIZZLE.
TEMPERATURES WARM INTO THE MID 40S.
IN THE TUESDAY THROUGH THURSDAY PERIOD AN AMPLIFIED UPPER TROUGH
WILL MOVE OUT OF THE SOUTHWEST U.S AND ACROSS THE CENTRAL PLAINS.
TEMPERATURE PROFILES SUGGEST THAT PRECIPITATION WILL BE IN THE FORM
OF RAIN FOR THE PERIOD. WARM ADVECTION LATE MONDAY NIGHT INTO
TUESDAY MORNING WITH INCREASING MOISTURE AND ISENTROPIC LIFT ALONG
WITH SOME ENERGY EJECTING FROM THE UPPER TROUGH TO BRING SOME
CHANCES FOR LIGHT RAIN. THE UPPER TROUGH WILL MOVE ACROSS THE PLAINS
WEDNESDAY AND WEDNESDAY NIGHT. SOME ELEVATED INSTABILITY MAY BE
PRESENT ON WEDNESDAY INTO WEDNESDAY EVENING SO KEPT MENTION OF
ISOLATED THUNDERSTORMS ALONG WITH SHOWERS. ON THE BACK SIDE OF THE
SYSTEM WEDNESDAY NIGHT SOUNDINGS NOT CONDUCIVE TO PRECIPITATION
AFTER 06Z THURSDAY IN THE NORTHWEST SO DID NOT INCLUDE ANY FROZEN
PRECIPITATION LATE IN THE NIGHT. UPPER WAVE MOVES OFF BY EARLY
THURSDAY THEN MODELS DIVERGE IN SOLUTIONS NEAR THE END OF THE PERIOD
FOR FRIDAY AND SATURDAY. GIVEN MODEL UNCERTAINTY LEFT FORECAST DRY
FOR FRIDAY AND SATURDAY. TEMPERATURES WILL BE COLDER FOR THE END OF
THE WEEK WITH ARCTIC AIR IN PLACE OVER THE REGION.
53
&&
.AVIATION...
CURRENT SATELLITE TRENDS SHOWS THE NORTHEASTWARD TRACK OF THE
FOG/STRATUS DECK OVER SW KANSAS. WHILE KMHK IS THE CLOSEST
AFFECTED TERMINAL...THE DEWPOINT DEPRESSIONS HAVE INCREASED ENOUGH
TO BELIEVE STRATUS DECK WILL NOT REACH THE TERMINALS AND HAVE
THEREFORE KEPT VFR CONDITIONS. SOUTHWEST WINDS OVER 10KTS THROUGH
THE AFTERNOON WILL CALM AFTER SUNSET WITH THE NAM AND RUC MODELS
INDICATING THE FOG/STRATUS TO DEVELOP OVER KTOP AND KMHK SATURDAY
EVENING. AT THIS TIME...HIGHER ELEVATION OVER KFOE MAY HOLD BACK
FOG WITH SOUTH WINDS SUSTAINED ABOVE 5 KTS. WILL CONTINUE TO
MONITOR STRATUS/FOG DECK AND AMEND AS NECESSARY.
BOWEN
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
333 PM CST SAT DEC 10 2011
.DISCUSSION...
MAIN CONCERN WILL BE STRATUS/FOG TONIGHT INTO SUN...THEN CHANCE OF
SHOWERS FOR TUE THROUGH THU.
TONIGHT:
SFC WINDS HAVE GRADUALLY SHIFTED AROUND TO THE SW TODAY AS THE UPPER
FLOW BECOMES MORE ZONAL. THIS RETURN FLOW HAS ALSO ADVECTED IN A LOW
CLOUD DECK FROM THE PANHANDLE OF TX/OK INTO SOUTH CENTRAL KS...WITH
THIS LOW CLOUD DECK EXPECTED TO BE PROBLEMATIC THIS EVE/TONIGHT.
NONE OF THE SHORT TERM MODELS ARE HANDLING THIS CLOUD DECK
WELL...BUT NOT REAL SURE WE WILL SEE THIS DECK DISSIPATE MUCH
OVERNIGHT...AS WEAK WARM ADVECTION CONTINUES ACROSS THE AREA..WITH
LITTLE OR NO MIXING. COULD ALSO SEE SOME PATCHY FOG ASSOCIATED WITH
IT...AS LOW LEVEL MOISTURE REMAINS TRAPPED UNDER THE CLOUD DECK..SO
WILL MENTION THIS AS WELL.
SUN-MON:
FAIRLY CERTAIN STRATUS DECK WILL BE AROUND ON SUN...WHICH WILL KEEP
MAX TEMPS DOWN SOME...BUT WEAK WARM ADVECTION WILL LEAD TO TEMPS A
LITTLE WARMER THAN TODAY. NAM/WRF AND GFS SEEM TO HAVE A LITTLE
BETTER HANDLE ON CLOUDS AND POSSIBLE DRIZZLE/FOG FOR SUN
NIGHT...ESPECIALLY ACROSS CEN KS. WILL HAVE TO KEEP A CLOSE EYE ON
TEMPS NORTH OF INTERSTATE 70...AS THIS AREA MAY SEE TEMPS HOVER NEAR
FREEZING...WHICH COULD LEAD TO FREEZING DRIZZLE THREAT. FOR NOW
THINK WEAK WARM ADVECTION WILL KEEP TEMPS JUST ABOVE FREEZING AND
ALL LIQUID. CERTAINLY LOOKS LIKE A GREY COOL DAY FOR MOST AREAS ON
SUN INTO MON. COULD ALSO SEE SOME OF THIS DRIZZLE REMAIN ACROSS MOST
OF CEN KS EARLY ON MON AS WELL.
TUE-THU:
MODELS STILL DIFFER ON HOW THE SHORTWAVE...THAT WILL BE CENTERED IN
THE SW US...WILL LIFT OUT INTO THE PLAINS FOR THE MIDDLE OF THE
WEEK. BOTH THE GFS AND ECMWF HAVE BEEN CONSISTENT IN STICKING WITH
THEIR DIFFERING SOLUTIONS. WITH THE ECMWF MORE PROGRESSIVE...WHILE
THE GFS IS DEEPER/STRONGER AND HAS MORE NEGATIVE TILT AS IT COMES
INTO THE PLAINS. WITH THAT SAID...THE LATEST ECMWF MY BE TRENDING
TOWARDS THE FURTHER SOUTH GFS SOLUTION. TIMING OF THE SYSTEM IN THE
TWO MODELS SEEMS TO BE THE THING THEY AGREE ON THE MOST...WITH THE
CONTINUED LOW LEVEL MOISTURE RETURN AND WARM ADVECTION EXPECTED TO
LEAD TO A CHANCE OF LIGHT RAIN FOR MOST OF THE AREA TUE. THE MAIN
PRECIP SHOW STILL LOOKS TO BE ON WED...AS SYNOPTIC LIFT FROM THE
MAIN SHORTWAVE LIFTS NORTHEAST ACROSS THE PLAINS...WITH LOTS OF LIFT
AND MOISTURE AROUND FOR A SOLID SHOWER CHANCE...FOR MOST AREAS. WILL
CONTINUE TO MENTION A FEW RUMBLES OF THUNDER ACROSS SRN/SERN KS AS
THIS SYSTEM MOVES THROUGH...WITH ALL THE PRECIP IN THE FORM OF
LIQUID. SYSTEM WILL MAKE ITS WAYS TO THE EAST OF THE AREA FOR LATE
WED NIGHT WITH COLDER AIR FILTERING INTO THE AREA FOR THU.
REST OF THE EXTENDED:
SOME UNCERTAINTY ON HOW THE BEGINNING OF THE WEEKEND WILL PLAY
OUT...WITH THE GFS DROPPING A COLD CANADIAN AIRMASS INTO THE AREA.
BUT THE ECMWF SHOWS QUITE A BAROCLINIC ZONE ACROSS THE AREA FOR
FRI...WHICH COULD LEAD TO A LIGHT SNOW CHANCE. MODEL CONSENSUS
SUGGESTS KEEPING THIS CHANCE IN FOR NOW.
KETCHAM
.AVIATION...18Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
IFR CIGS CONTINUE TO IMPACT MUCH OF THE AREA EARLY THIS AFTERNOON
AND RECENT SATELLITE TRENDS SUPPORT THIS AREA EXPANDING TO INCLUDE
ALL TERMINALS WITH THE EXCEPTION OF KCNU. BY 20-21Z...LOW CLOUDS MAY
START TO BECOME SCATTERED BUT MVFR/IFR MAY RAPIDLY RETURN THIS
EVENING WITH LIGHT SOUTHERLY WINDS AND VERY LOW TEMPERATURE-
DEWPOINT SPREADS. THE LATEST HRRR SUPPORTS MAINTAINING LOW CIGS
AND REDUCTIONS IN VISIBILITY INTO THE OVERNIGHT HOURS AND UPCOMING
AMENDMENTS MAY BECOME NECESSARY AS CONFIDENCE INCREASES.
MCGUIRE
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 26 46 35 49 / 0 10 10 10
HUTCHINSON 26 44 34 50 / 0 10 10 10
NEWTON 26 43 35 47 / 0 10 10 10
ELDORADO 27 45 35 47 / 0 10 10 10
WINFIELD-KWLD 27 47 35 49 / 0 10 10 10
RUSSELL 23 43 34 47 / 0 10 10 10
GREAT BEND 24 45 34 48 / 0 10 10 10
SALINA 25 46 35 48 / 0 10 10 10
MCPHERSON 26 44 34 48 / 0 10 10 10
COFFEYVILLE 27 48 33 46 / 0 10 10 10
CHANUTE 26 46 34 45 / 0 0 10 10
IOLA 26 45 34 45 / 0 0 10 10
PARSONS-KPPF 26 47 34 45 / 0 0 10 10
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
1211 PM CST SAT DEC 10 2011
.UPDATE...
WIDESPREAD STRATUS AND FOG CONTINUE TO IMPACT MUCH OF SOUTH
CENTRAL AND CENTRAL KANSAS. THIS AREA OF REDUCED VISIBILITIES AND
LOW CLOUDS WILL CONTINUE TO SPREAD SLOWLY NORTHEAST BEFORE MIXING
OUT BY MID-LATE AFTERNOON. TRENDED HIGHS DOWN ACROSS MUCH OF THE WESTERN
ZONES WHERE TEMPERATURES WILL STRUGGLE TO GET OUT OF THE 30S.
MCGUIRE
&&
.AVIATION...Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
IFR CIGS CONTINUE TO IMPACT MUCH OF THE AREA EARLY THIS AFTERNOON
AND RECENT SATELLITE TRENDS SUPPORT THIS AREA EXPANDING TO INCLUDE
ALL TERMINALS WITH THE EXCEPTION OF KCNU. BY 20-21Z...LOW CLOUDS MAY
START TO BECOME SCATTERED BUT MVFR/IFR MAY RAPIDLY RETURN THIS
EVENING WITH LIGHT SOUTHERLY WINDS AND VERY LOW TEMPERATURE-
DEWPOINT SPREADS. THE LATEST HRRR SUPPORTS MAINTAINING LOW CIGS
AND REDUCTIONS IN VISIBILITY INTO THE OVERNIGHT HOURS AND UPCOMING
AMENDMENTS MAY BECOME NECESSARY AS CONFIDENCE INCREASES.
MCGUIRE
&&
.PREV DISCUSSION... /ISSUED 959 AM CST SAT DEC 10 2011/
UPDATE...
WIDESPREAD DENSE FOG ACROSS SOUTHWEST KANSAS AND PORTIONS OF
WESTERN OKLAHOMA CONTINUES TO DRIFT NORTHEASTWARD IMPACTING
PORTIONS OF CENTRAL AND SOUTH CENTRAL KANSAS. ALTHOUGH CONTINUED
MIXING SHOULD RESULT IN A GRADUAL INCREASE IN VISIBILITIES/CEILINGS
THE FORECAST WAS ADJUSTED TO TO MAINTAIN AREAS OF FOG/CLOUDY
WORDING THROUGH THE MORNING HOURS.
MCGUIRE
PREV DISCUSSION... /ISSUED 525 AM CST SAT DEC 10 2011/
AVIATION...12Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
THE ONLY PERIOD OF CONCERN IS EARLY THIS MORNING WHEN PATCHY FOG MAY
REDUCE VSBYS TO 4-5SM TIL 14Z-15Z. SHOULD BE EXCELLENT FLYING WEATHER
THEREAFTER...HOWEVER SW WINDS WILL INCREASE TO ~13KTS/15MPH OVER ALL
5 TERMINALS ~15Z AS BROAD WRN PLAINS SFC TROF GRADUALLY ASSERTS
ITSELF.
PREV DISCUSSION... /ISSUED 258 AM CST SAT DEC 10 2011/
DISCUSSION...
MAIN FORECAST CHALLENGE WILL BE PRECIP CHANCES FOR NEXT WEEK.
SYNOPSIS:
UPPER TROUGH EXTENDS FROM THE EASTERN GREAT LAKES INTO THE LOWER
MISSISSIPPI VALLEY. AT THE SURFACE HIGH PRESSURE IS CENTERED OVER
THE OZARK REGION AND ENCOMPASSES ALL OF EASTERN KS AND OK. THE LOW
CLOUDS QUICKLY DISSIPATED AROUND 10PM WITH CLEAR SKIES REMAINING
OVER THE AREA. THE GOOD RADIATIONAL COOLING CONDITIONS HAVE RESULTED
IN SOME PATCHY FOG ACROSS PORTIONS OF THE AREA WITH WIDESPREAD DENSE
FOG NOT EXPECTED THIS MORNING.
TODAY-TONIGHT:
THE UPPER TROUGH TO OUR EAST WILL CONTINUE TO QUICKLY PUSH EAST WITH
THE SURFACE HIGH EXPECTED TO EXTEND FROM THE OHIO VALLEY INTO THE
ARKLATEX REGION BY LATE THIS AFTERNOON. THIS WILL FLIP OUR WINDS
AROUND TO THE SW PROVIDING A SLIGHT WARM-UP. WATER VAPOR IMAGERY IS
SHOWING A WEAK UPPER IMPULSE OVER EASTERN WY AND SLIDING SLOWLY
SOUTHEAST. THIS FEATURE IS EXPECTED TO SLIDE OVER WEST-CENTRAL KS
TONIGHT BUT DUE TO THE DRY AIRMASS IN PLACE NO PRECIP IS EXPECTED
WITH THIS FEATURE. THE MAIN IMPACT THIS WAVE WILL HAVE WILL BE TO
TIGHTEN-UP THE PRESSURE GRADIENT OVER THE AREA ALLOWING FOR STRONGER
SOUTH WINDS.
SUN-MON:
THE MAIN THEME THROUGH THESE PERIODS WILL BE INCREASING RETURN FLOW
AND ASSOCIATED MOISTURE. GUSTY SOUTH WINDS WILL BE IN PLACE ON SUN
WHICH WILL ALLOW LOW LEVEL MOISTURE TO RAPIDLY INCREASE. BOTH THE
GFS AND NAM AGREE ON LOW CLOUDS QUICKLY PUSHING INTO THE WESTERN HALF
OF THE FORECAST AREA BY SUN AFTERNOON WITH THESE LOW CIGS HERE TO
STAY. WENT AHEAD AND INSERTED SOME DRIZZLE AND LIGHT FOG FOR CENTRAL
KS ON SUN NIGHT. EVEN THOUGH MOISTURE QUICKLY INCREASES...LACK OF
DEEP LIFT WILL LIMIT CHANCES FOR MEASURABLE PRECIP WITH DRIZZLE THE
MAIN PRECIP MODE. IF WE WOULD HAVE A COLDER AIRMASS IN PLACE WE
WOULD BE LOOKING AT A CLASSIC FREEZING DRIZZLE SETUP. LUCKILY TEMPS
ARE EXPECTED TO REMAIN ABOVE FREEZING THROUGH THIS TIME PERIOD.
TUE-FRI:
THROUGH THIS TIME FRAME IS WHEN THE SHORT WAVE IS STILL EXPECTED TO
DIRECTLY IMPACT THE AREA. EVEN THOUGH THE GFS IS SLIGHTLY DEEPER AND
NOT AS POSITIVELY TILTED AS THE ECMWF...THEY AGREE MUCH BETTER ON THE
TIMING OF THIS FEATURE COMPARED TO LAST NIGHT`S RUNS. WILL START
PRECIP CHANCES ON TUE WITH CHANCES INCREASING FOR WED AS THE UPPER
WAVE KICKS OUT OF THE SOUTHERN ROCKIES AND INTO THE HIGH PLAINS.
THIS WAVE IS EXPECTED TO RAPIDLY LIFT OFF OT THE NORTHEAST ONCE IT
GETS OUT INTO THE PLAINS WITH THE PRECIP CHANCES COMING TO AN END BY
EARLY THU MORNING. ONCE AGAIN IT LOOKS LIKE THE TEMP PROFILE WILL
REMAIN WARM ENOUGH TO KEEP ALL OF THE PRECIP IN LIQUID FORM.
LAWSON
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 40 26 48 35 / 0 0 10 10
HUTCHINSON 40 26 47 34 / 0 0 10 10
NEWTON 42 26 47 35 / 0 0 10 10
ELDORADO 43 27 48 35 / 0 0 10 10
WINFIELD-KWLD 40 27 49 35 / 0 0 10 10
RUSSELL 40 23 44 34 / 0 0 10 10
GREAT BEND 40 24 45 34 / 0 0 10 10
SALINA 44 25 47 35 / 0 0 10 10
MCPHERSON 43 26 47 34 / 0 0 10 10
COFFEYVILLE 45 27 49 33 / 0 0 10 10
CHANUTE 45 26 49 34 / 0 0 0 10
IOLA 44 26 48 34 / 0 0 0 10
PARSONS-KPPF 45 26 49 34 / 0 0 0 10
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1152 AM CST SAT DEC 10 2011
...UPDATE TO AVIATION...
.DISCUSSION...
SHORT RANGE FORECAST (TODAY AND SUNDAY)...
09Z WATER VAPOR IMAGERY AND ASSOCIATED 500 MB RUC ANALYSIS INDICATES
A BROAD 500 MB TROUGH CENTERED OVER EASTERN CANADA WITH ITS AXIS
RUNNING SOUTHWESTWARD THROUGH THE OHIO RIVER VALLEY...LEAVING
NORTHWEST FLOW OVER THE CENTRAL PLAINS. AT THE SURFACE THE RIDGE OF
HIGH PRESSURE IS MOVING OFF TO THE EAST ALLOWING FOR SOUTHERLY FLOW
TO RETURN TO THE AREA...ESPECIALLY ACROSS WESTERN AND CENTRAL
KANSAS. SOME AREAS ACROSS WESTERN/CENTRAL KANSAS HAS SEEN SOME FOG
DEVELOPMENT OVERNIGHT...BUT NORTHEAST KANSAS HAS THUS FAR BEEN
SPARED ANY WIDESPREAD FOG ISSUES...AND EXPECT THAT TO CONTINUE
THROUGH THE MORNING HOURS...SAVE A FEW AREAS OF PATCHY FOG WEST A
MARYSVILLE TO EMPORIA LINE. EXPECT SOUTHWESTERLY FLOW TO PICK UP
TODAY WHICH WILL ACT TO BRING A GRADUAL WARMING TREND THROUGH THE
WEEKEND. BY LATE IN THE WEEKEND THE SURFACE PRESSURE GRADIENT
BETWEEN THE SLOWLY DEPARTING SURFACE HIGH TO THE EAST AND A
DEVELOPING LOW ON THE LEE SIDE OF THE ROCKY MOUNTAINS WILL ALLOW
FOR THE SOUTHERLY FLOW TO PICK UP FOR SUNDAY AND MONDAY...BRINGING
GUSTY CONDITIONS FOR SUNDAY AND CONTINUING THE GRADUAL WARMING
TREND INTO MONDAY.
MID-RANGE AND EXTENDED FORECAST (MONDAY THROUGH FRIDAY)...
WITH A STRONG PUSH OF WARM/MOIST AIR INTO THE AREA FOR THE FIRST
PART OF THE WEEK EXPECT CLOUDS TO BUILD-IN. SATURATION IS EXPECTED
TO OCCUR AROUND 800 MB AS PARCELS ARE LIFTED ISENTROPICALLY. GIVEN
THE LACK OF DEEP MOISTURE DO NOT EXPECT ANYTHING MORE THAN SOME
AREAS OF DRIZZLE IN NORTH CENTRAL KANSAS...AND POSSIBLY A FEW
SPRINKLES IN FAR NORTHEAST KANSAS ON MONDAY WHERE ENHANCED LIFT
WOULD OCCUR IN RESPONSE TO A QUICKLY MOVING SUBTLE SHORTWAVE
TROUGH MOVING THROUGH THE PLAINS.
BY MID WEEK A DEEPLY AMPLIFIED SOUTHERN STREAM UPPER TROUGH WILL DIG
SOUTHWARD ALONG THE PACIFIC COASTLINE BEFORE EJECTING EASTWARD
ACROSS THE INTERIOR WESTERN CONUS. DECIDED TO SIDE WITH THE 00Z
ECMWF REGARDING THE TIMING OF THE EFFECTS FROM THIS SYSTEM. ON
TUESDAY A LEADING IMPULSE WILL PUSH OUT AHEAD OF THE MAIN WAVE
BRINGING A CHANCE FOR RAIN ON TUESDAY AFTERNOON. RAIN CHANCES
SHOULD CONTINUE AS THE MAIN UPPER TROUGH WILL PUSH INTO THE AREA
BY MID DAY ON WEDNESDAY. THERMAL PROFILES STILL SUGGEST THIS
SYSTEM WILL BE PRIMARILY RAIN. SOME MEAGER ELEVATED INSTABILITY
MAY BE PRESENT ONCE SHOWERS COMMENCE ON WEDNESDAY SO KEPT A
MENTION OF ISOLATED THUNDER WITHIN THE STRATIFORM RAIN. ASIDE FROM
AN ISOLATED THUNDER THREAT AREAS OF MODERATE RAIN MAY OCCUR WITHIN
THOSE POCKETS OF MODEST INSTABILITY. GIVEN THE WARM 850 MB TEMPS AND
THE PROGRESSION OF THE SYSTEM...THE ONLY REAL CHANCE FOR ANY
WINTRY TYPE OF PRECIPITATION WILL BE A MIX OF RAIN AND SNOW ACROSS
NORTH CENTRAL KANSAS ON THE WESTERN EDGE OF THE PRECIPITATION ONCE
THE COLDER AIR MOVES IN BEHIND THE PRECIP. EXPECT THE UPPER WAVE
AND ITS SUBSEQUENT RAINY CONDITIONS TO BE CLEAR OF NORTHEAST KANSAS BY
THURSDAY. ECMWF THEN PROGS A FAIRLY POTENT COLD FRONT MOVING INTO
THE CENTRAL PLAINS ALONG THE SOUTHERN EDGE OF A SOUTHWARD DIVING
RIDGE OF HIGH PRESSURE. EXPECT TEMPS TO BE QUITE COOLER FOR THE
END OF THE WEEK AS THE ARCTIC AIR MASS SETTLES INTO THE AREA.
JL
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
.AVIATION...
CURRENT SATELLITE TRENDS SHOWS THE NORTHEASTWARD TRACK OF THE
FOG/STRATUS DECK OVER SW KANSAS. WHILE KMHK IS THE CLOSEST
AFFECTED TERMINAL...THE DEWPOINT DEPRESSIONS HAVE INCREASED ENOUGH
TO BELIEVE STRATUS DECK WILL NOT REACH THE TERMINALS AND HAVE
THEREFORE KEPT VFR CONDITIONS. SOUTHWEST WINDS OVER 10KTS THROUGH
THE AFTERNOON WILL CALM AFTER SUNSET WITH THE NAM AND RUC MODELS
INDICATING THE FOG/STRATUS TO DEVELOP OVER KTOP AND KMHK SATURDAY
EVENING. AT THIS TIME...HIGHER ELEVATION OVER KFOE MAY HOLD BACK
FOG WITH SOUTH WINDS SUSTAINED ABOVE 5 KTS. WILL CONTINUE TO
MONITOR STRATUS/FOG DECK AND AMEND AS NECESSARY.
BOWEN
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
539 AM CST SAT DEC 10 2011
...UPDATE TO AVIATION...
&&
.AVIATION...
VFR CONDITIONS EXPECTED THROUGH THE PERIOD. SMALL POCKET OF 9000FT
CLOUD DECK TO PASS OVER IN EARLY TAF PERIOD. OTHERWISE WINDS
BECOME SOUTHWESTERLY NEAR 12 KTS BY AFTERNOON HOURS THEN
DIMINISHING AGAIN OVERNIGHT LATE IN THE PERIOD. 67
&&
.PREV DISCUSSION...
/ISSUED 353 AM CST SAT DEC 10 2011/
SHORT RANGE FORECAST (TODAY AND SUNDAY)...
09Z WATER VAPOR IMAGERY AND ASSOCIATED 500 MB RUC ANALYSIS INDICATES
A BROAD 500 MB TROUGH CENTERED OVER EASTERN CANADA WITH ITS AXIS
RUNNING SOUTHWESTWARD THROUGH THE OHIO RIVER VALLEY...LEAVING
NORTHWEST FLOW OVER THE CENTRAL PLAINS. AT THE SURFACE THE RIDGE OF
HIGH PRESSURE IS MOVING OFF TO THE EAST ALLOWING FOR SOUTHERLY FLOW
TO RETURN TO THE AREA...ESPECIALLY ACROSS WESTERN AND CENTRAL
KANSAS. SOME AREAS ACROSS WESTERN/CENTRAL KANSAS HAS SEEN SOME FOG
DEVELOPMENT OVERNIGHT...BUT NORTHEAST KANSAS HAS THUS FAR BEEN
SPARED ANY WIDESPREAD FOG ISSUES...AND EXPECT THAT TO CONTINUE
THROUGH THE MORNING HOURS...SAVE A FEW AREAS OF PATCHY FOG WEST A
MARYSVILLE TO EMPORIA LINE. EXPECT SOUTHWESTERLY FLOW TO PICK UP
TODAY WHICH WILL ACT TO BRING A GRADUAL WARMING TREND THROUGH THE
WEEKEND. BY LATE IN THE WEEKEND THE SURFACE PRESSURE GRADIENT
BETWEEN THE SLOWLY DEPARTING SURFACE HIGH TO THE EAST AND A
DEVELOPING LOW ON THE LEE SIDE OF THE ROCKY MOUNTAINS WILL ALLOW
FOR THE SOUTHERLY FLOW TO PICK UP FOR SUNDAY AND MONDAY...BRINGING
GUSTY CONDITIONS FOR SUNDAY AND CONTINUING THE GRADUAL WARMING
TREND INTO MONDAY.
MID-RANGE AND EXTENDED FORECAST (MONDAY THROUGH FRIDAY)...
WITH A STRONG PUSH OF WARM/MOIST AIR INTO THE AREA FOR THE FIRST
PART OF THE WEEK EXPECT CLOUDS TO BUILD-IN. SATURATION IS EXPECTED
TO OCCUR AROUND 800 MB AS PARCELS ARE LIFTED ISENTROPICALLY. GIVEN
THE LACK OF DEEP MOISTURE DO NOT EXPECT ANYTHING MORE THAN SOME
AREAS OF DRIZZLE IN NORTH CENTRAL KANSAS...AND POSSIBLY A FEW
SPRINKLES IN FAR NORTHEAST KANSAS ON MONDAY WHERE ENHANCED LIFT
WOULD OCCUR IN RESPONSE TO A QUICKLY MOVING SUBTLE SHORTWAVE
TROUGH MOVING THROUGH THE PLAINS.
BY MID WEEK A DEEPLY AMPLIFIED SOUTHERN STREAM UPPER TROUGH WILL DIG
SOUTHWARD ALONG THE PACIFIC COASTLINE BEFORE EJECTING EASTWARD
ACROSS THE INTERIOR WESTERN CONUS. DECIDED TO SIDE WITH THE 00Z
ECMWF REGARDING THE TIMING OF THE EFFECTS FROM THIS SYSTEM. ON
TUESDAY A LEADING IMPULSE WILL PUSH OUT AHEAD OF THE MAIN WAVE
BRINGING A CHANCE FOR RAIN ON TUESDAY AFTERNOON. RAIN CHANCES
SHOULD CONTINUE AS THE MAIN UPPER TROUGH WILL PUSH INTO THE AREA
BY MID DAY ON WEDNESDAY. THERMAL PROFILES STILL SUGGEST THIS
SYSTEM WILL BE PRIMARILY RAIN. SOME MEAGER ELEVATED INSTABILITY
MAY BE PRESENT ONCE SHOWERS COMMENCE ON WEDNESDAY SO KEPT A
MENTION OF ISOLATED THUNDER WITHIN THE STRATIFORM RAIN. ASIDE FROM
AN ISOLATED THUNDER THREAT AREAS OF MODERATE RAIN MAY OCCUR WITHIN
THOSE POCKETS OF MODEST INSTABILITY. GIVEN THE WARM 850 MB TEMPS AND
THE PROGRESSION OF THE SYSTEM...THE ONLY REAL CHANCE FOR ANY
WINTRY TYPE OF PRECIPITATION WILL BE A MIX OF RAIN AND SNOW ACROSS
NORTH CENTRAL KANSAS ON THE WESTERN EDGE OF THE PRECIPITATION ONCE
THE COLDER AIR MOVES IN BEHIND THE PRECIP. EXPECT THE UPPER WAVE
AND ITS SUBSEQUENT RAINY CONDITIONS TO BE CLEAR OF NORTHEAST KANSAS BY
THURSDAY. ECMWF THEN PROGS A FAIRLY POTENT COLD FRONT MOVING INTO
THE CENTRAL PLAINS ALONG THE SOUTHERN EDGE OF A SOUTHWARD DIVING
RIDGE OF HIGH PRESSURE. EXPECT TEMPS TO BE QUITE COOLER FOR THE
END OF THE WEEK AS THE ARCTIC AIR MASS SETTLES INTO THE AREA.
JL
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
500 AM CST SAT DEC 10 2011
.AVIATION...
FOR THE 12Z TAF ISSUANCE...
LOW LEVEL STRATUS/FOG WILL MOVE EAST ACROSS SOUTHWEST KANSAS EARLY
THIS MORNING WITH IFR CIGS/VSBYS LIKELY EARLY THIS MORNING IN THE
VICINITY OF KGCK, KDDC, AND POSSIBLY AS FAR NORTH AS KHYS. IFR
CIGS/VSBYS ARE EXPECTED TO PERSIST THROUGH LATE MORNING WITH
CONDITIONS BEGINNING TO GRADUALLY IMPROVE WEST TO EAST ACROSS
WESTERN PORTIONS OF THE FORECAST AREA BY THIS AFTERNOON. A LEE
SIDE TROUGH WILL CONTINUE TO STRENGTHEN ACROSS EASTERN COLORADO
TODAY INFLUENCING SOUTH TO SOUTHWESTERLY WINDS 10 TO 20KT THROUGH
TONIGHT.
&&
.PREV DISCUSSION... /ISSUED 313 AM CST SAT DEC 10 2011/
DISCUSSION...
DAYS 1-2...
THE MAIN FORECAST CHALLENGES ARE HOW FAR EAST DENSE FOG CAN GET THIS
MORNING AND TEMPERATURES AND CLOUD COVER ON SUNDAY.
AS AN UPPER LEVEL TROUGH MOVES EAST TODAY DRY WEST TO NORTHWEST
UPPER LEVEL FLOW WILL PREVAIL. LIGHT SOUTHWEST WINDS ON THE BACKSIDE
OF A DEPARTING RIDGE OF SURFACE HIGH PRESSURE WAS ADVECTING HIGHER
DEWPOINTS BACK INTO FAR SOUTHWEST KANSAS WITH AREAS OF DENSE FOG.
THE NEWEST RUN OF THE HRRR MODEL SHOWS THE DENSE FOG AND STRATUS MAY
BE CLOSE TO DODGE CITY AND MEADE BY SUNRISE. WILL HAVE TO CONTINUE
TO MONITOR TRENDS TO SEE IF WE NEED TO EXPAND THE CURRENT DENSE FOG
ADVISORY MORE EAST. DEPENDING ON STRATUS SOME AREAS WILL NOT BE ABLE
TO SEE AN ALMOST TOTAL LUNAR ECLIPSE BY SUNRISE AND MOONSET. LATER
IN THE MORNING ANY SHALLOW FOG AND STRATUS SHOULD LIFT WITH SKIES
BECOMING SUNNY. SOUTHWEST WINDS WILL PICK UP A BIT TO 10 TO 15 MPH
WITH HIGHS FROM NEAR 40 OVER THE SNOW PACK IN THE FAR NORTHWEST FA
TO THE MID 40S ELSEWHERE.
FOR TONIGHT AN UPPER LEVEL DRY SHORTWAVE TROUGH MOVES THROUGH THE
PLAINS. A LEE TROUGH DEEPENS BY MORNING IN THE LEE OF THE ROCKIES
WITH A TIGHTENING PRESSURE GRADIENT OVER WESTERN KANSAS. SOUTH WINDS
SHOULD STAY MIXED IN THE 10 TO 20 MPH RANGE. MODEL BUFFER SOUNDINGS
SHOW SOME SHALLOW GROUND FOG BUT WITH A WELL MIXED BOUNDARY LAYER DO
NOT EXPECT STRATUS AT THIS TIME. WILL GO WITH LOWS FROM AROUND 20
FAR NORTHWEST TO THE MID 20S ELSEWHERE IN THE FA.
FOR SUNDAY WE TRANSITION TO SOUTHWEST UPPER LEVEL FLOW OVER THE
PLAINS WITH A 60 TO 70 KNOT JET OVER THE COLORADO ROCKIES. THE
STRONG FLOW WILL INDUCE A DEEPENING LEE LOW AND AN INCREASING
SURFACE PRESSURE GRADIENT OVER WESTERN AND CENTRAL KANSAS. BY MID TO
LATE MORNING AS MIXING OCCURS SOUTH WINDS WILL PICK UP TO 25 TO 35
MPH AND THIS MAY BE CLOSE TO A WIND ADVISORY. ALSO HIGHER DEWPOINTS
INTO THE MID 30S MOVE INTO WESTERN KANSAS. BUFFER SOUNDINGS SHOW LOW
LEVEL MOISTURE DEPTH INCREASING WITH STRATUS DEVELOPING IN THE
AFTERNOON. WILL SLOWLY INCREASE CLOUDS TO MOSTLY CLOUDY BY LATE
AFTERNOON. HIGH TEMPERATURES WILL BE TRICKY IF STRATUS DEVELOPS
HOWEVER STRONG MIXING MAY OFFSET THE STRATUS. FOR NOW WILL KEEP
HIGHS IN THE LOW TO MID 40S GOING.
ON SUNDAY NIGHT AN UPPER LEVEL JET MOVES OVER KANSAS WITH A LEE
TROUGH PUSHING A BIT EAST INTO EXTREME SOUTHWESTERN KANSAS. BUFFER
SOUNDINGS SHOW A SATURATED MOIST BOUNDARY LAYER UP TO AROUND 850MB
ALONG WITH SOUTH WINDS OF 15 TO 25 MPH. WINDS WILL BE LOWER CLOSER
TO THE TROUGH IN FAR SOUTHWEST KANSAS. ALSO HIGH CLOUDS WILL BECOME
THICKER TOWARDS MORNING. WILL GO WITH INCREASING CLOUDS WITH MOST OF
THE FA UNDER STRATUS EXCEPT FOR THE FAR WEST. LOWS WILL BE AROUND 30
FAR WEST TO THE MID TO UPPER 30S EAST WITH GOOD MIXING AND LOW
CLOUDS.
DAYS 3-7...
MEDIUM RANGE MODELS INDICATE AN UPPER LEVEL TROUGH OF LOW PRESSURE
PUSHING ASHORE IN EXTREME SOUTHERN CALIFORNIA MONDAY NIGHT INTO
TUESDAY BRINGING THE POSSIBILITY FOR PRECIP TO CENTRAL AND PORTIONS
OF WESTERN KANSAS LATE TUESDAY INTO WEDNESDAY. AS THE TROUGH ALOFT
APPROACHES, THE GEM, GFS, AND ECMWF SHOW A STRONG +130KT UPPER LEVEL
JET DEVELOPING ACROSS THE SOUTH PLAINS OF FAR WEST TEXAS NORTHEAST
INTO WESTERN KANSAS BY TUESDAY EVENING. MEANWHILE, AMPLE LOW LEVEL
MOISTURE IS PROJECTED TO NOSE NORTHWARD INTO SOUTH CENTRAL AND
PORTIONS OF SOUTHWEST KANSAS DURING THE DAY TUESDAY WITH H85
DEWPOINTS NEAR TO JUST ABOVE 5C. ALONG WITH STRONG UPPER LEVEL
DYNAMIC SUPPORT INCREASING, SURFACE LOW PRESSURE IS EXPECTED TO
DEVELOP GENERALLY IN EAST CENTRAL TO SOUTHEASTERN COLORADO BY
TUESDAY EVENING. COMBINED WITH SURFACE HIGH PRESSURE SET UP IN THE
EASTERN CONUS, THIS WILL HELP INCREASE LOW LEVEL FORCING ACROSS THE
CENTRAL PLAINS. AS A RESULT, RAIN WILL BE POSSIBLE IN SOUTH CENTRAL
KANSAS WHERE AVAILABLE MOISTURE WILL BE BEST WITH LESSER CHANCES
EXTENDING WEST INTO SOUTHWESTERN KANSAS. ISOLATED THUNDER CANNOT
BE COMPLETELY RULED OUT FOR FAR EASTERN PORTIONS OF THE CWA ON
WEDNESDAY.
TEMPERATURES WILL BE AT LEAST SEASONAL IF NOT SLIGHTLY ABOVE ON
MONDAY AS SURFACE LOW PRESSURE SET UP JUST OUR WEST AND SOUTHWEST
CONTINUES TO INFLUENCE MARGINAL WARM AIR ADVECTION INTO WESTERN
KANSAS. THE GEM, GFS, AND ECMWF SHOW H85 TEMPERATURES AROUND 2C TO
4C ACROSS THE CWA BY MONDAY AFTERNOON WITH THE WARMEST TEMPERATURES
IN OUR SOUTH. SHOULD SEE HIGHS UP INTO THE 40S(F) ACROSS THE
FORECAST AREA WITH LOWER TO MID 50S(F) POSSIBLE IN OUR SOUTHEAST.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 45 25 45 36 / 0 0 0 10
GCK 44 24 44 32 / 0 0 0 0
EHA 44 25 44 28 / 0 0 0 0
LBL 44 25 45 34 / 0 0 0 0
HYS 42 24 44 34 / 0 0 0 10
P28 46 26 47 37 / 0 0 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 9 AM CST /8 AM MST/ THIS MORNING FOR
KSZ030-031-043>046-061>065-075>080-085>088.
&&
$$
FN32/99/99
AREA FORECAST DISCUSSION
NWS TOPEKA KS
353 AM CST SAT DEC 10 2011
.DISCUSSION...
SHORT RANGE FORECAST (TODAY AND SUNDAY)...
09Z WATER VAPOR IMAGERY AND ASSOCIATED 500 MB RUC ANALYSIS INDICATES
A BROAD 500 MB TROUGH CENTERED OVER EASTERN CANADA WITH ITS AXIS
RUNNING SOUTHWESTWARD THROUGH THE OHIO RIVER VALLEY...LEAVING
NORTHWEST FLOW OVER THE CENTRAL PLAINS. AT THE SURFACE THE RIDGE OF
HIGH PRESSURE IS MOVING OFF TO THE EAST ALLOWING FOR SOUTHERLY FLOW
TO RETURN TO THE AREA...ESPECIALLY ACROSS WESTERN AND CENTRAL
KANSAS. SOME AREAS ACROSS WESTERN/CENTRAL KANSAS HAS SEEN SOME FOG
DEVELOPMENT OVERNIGHT...BUT NORTHEAST KANSAS HAS THUS FAR BEEN
SPARED ANY WIDESPREAD FOG ISSUES...AND EXPECT THAT TO CONTINUE
THROUGH THE MORNING HOURS...SAVE A FEW AREAS OF PATCHY FOG WEST A
MARYSVILLE TO EMPORIA LINE. EXPECT SOUTHWESTERLY FLOW TO PICK UP
TODAY WHICH WILL ACT TO BRING A GRADUAL WARMING TREND THROUGH THE
WEEKEND. BY LATE IN THE WEEKEND THE SURFACE PRESSURE GRADIENT
BETWEEN THE SLOWLY DEPARTING SURFACE HIGH TO THE EAST AND A
DEVELOPING LOW ON THE LEE SIDE OF THE ROCKY MOUNTAINS WILL ALLOW
FOR THE SOUTHERLY FLOW TO PICK UP FOR SUNDAY AND MONDAY...BRINGING
GUSTY CONDITIONS FOR SUNDAY AND CONTINUING THE GRADUAL WARMING
TREND INTO MONDAY.
MID-RANGE AND EXTENDED FORECAST (MONDAY THROUGH FRIDAY)...
WITH A STRONG PUSH OF WARM/MOIST AIR INTO THE AREA FOR THE FIRST
PART OF THE WEEK EXPECT CLOUDS TO BUILD-IN. SATURATION IS EXPECTED
TO OCCUR AROUND 800 MB AS PARCELS ARE LIFTED ISENTROPICALLY. GIVEN
THE LACK OF DEEP MOISTURE DO NOT EXPECT ANYTHING MORE THAN SOME
AREAS OF DRIZZLE IN NORTH CENTRAL KANSAS...AND POSSIBLY A FEW
SPRINKLES IN FAR NORTHEAST KANSAS ON MONDAY WHERE ENHANCED LIFT
WOULD OCCUR IN RESPONSE TO A QUICKLY MOVING SUBTLE SHORTWAVE
TROUGH MOVING THROUGH THE PLAINS.
BY MID WEEK A DEEPLY AMPLIFIED SOUTHERN STREAM UPPER TROUGH WILL DIG
SOUTHWARD ALONG THE PACIFIC COASTLINE BEFORE EJECTING EASTWARD
ACROSS THE INTERIOR WESTERN CONUS. DECIDED TO SIDE WITH THE 00Z
ECMWF REGARDING THE TIMING OF THE EFFECTS FROM THIS SYSTEM. ON
TUESDAY A LEADING IMPULSE WILL PUSH OUT AHEAD OF THE MAIN WAVE
BRINGING A CHANCE FOR RAIN ON TUESDAY AFTERNOON. RAIN CHANCES
SHOULD CONTINUE AS THE MAIN UPPER TROUGH WILL PUSH INTO THE AREA
BY MID DAY ON WEDNESDAY. THERMAL PROFILES STILL SUGGEST THIS
SYSTEM WILL BE PRIMARILY RAIN. SOME MEAGER ELEVATED INSTABILITY
MAY BE PRESENT ONCE SHOWERS COMMENCE ON WEDNESDAY SO KEPT A
MENTION OF ISOLATED THUNDER WITHIN THE STRATIFORM RAIN. ASIDE FROM
AN ISOLATED THUNDER THREAT AREAS OF MODERATE RAIN MAY OCCUR WITHIN
THOSE POCKETS OF MODEST INSTABILITY. GIVEN THE WARM 850 MB TEMPS AND
THE PROGRESSION OF THE SYSTEM...THE ONLY REAL CHANCE FOR ANY
WINTRY TYPE OF PRECIPITATION WILL BE A MIX OF RAIN AND SNOW ACROSS
NORTH CENTRAL KANSAS ON THE WESTERN EDGE OF THE PRECIPITATION ONCE
THE COLDER AIR MOVES IN BEHIND THE PRECIP. EXPECT THE UPPER WAVE
AND ITS SUBSEQUENT RAINY CONDITIONS TO BE CLEAR OF NORTHEAST KANSAS BY
THURSDAY. ECMWF THEN PROGS A FAIRLY POTENT COLD FRONT MOVING INTO
THE CENTRAL PLAINS ALONG THE SOUTHERN EDGE OF A SOUTHWARD DIVING
RIDGE OF HIGH PRESSURE. EXPECT TEMPS TO BE QUITE COOLER FOR THE
END OF THE WEEK AS THE ARCTIC AIR MASS SETTLES INTO THE AREA.
JL
&&
.AVIATION...
STRATUS IS RAPIDLY ON THE DECREASE OVER THE AREA AND EXPECT VFR
CONDITIONS TO PERSIST THROUGH THE TAF PERIOD. LIGHT WINDS
OVERNIGHT WILL BECOME SOUTHERLY BY MID MORNING...WITH SUSTAINED
SPEEDS REACHING 10-12KTS BY AFTERNOON.
BLAIR
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
313 AM CST SAT DEC 10 2011
.DISCUSSION...
DAYS 1-2...
THE MAIN FORECAST CHALLENGES ARE HOW FAR EAST DENSE FOG CAN GET THIS
MORNING AND TEMPERATURES AND CLOUD COVER ON SUNDAY.
AS AN UPPER LEVEL TROUGH MOVES EAST TODAY DRY WEST TO NORTHWEST
UPPER LEVEL FLOW WILL PREVAIL. LIGHT SOUTHWEST WINDS ON THE BACKSIDE
OF A DEPARTING RIDGE OF SURFACE HIGH PRESSURE WAS ADVECTING HIGHER
DEWPOINTS BACK INTO FAR SOUTHWEST KANSAS WITH AREAS OF DENSE FOG.
THE NEWEST RUN OF THE HRRR MODEL SHOWS THE DENSE FOG AND STRATUS MAY
BE CLOSE TO DODGE CITY AND MEADE BY SUNRISE. WILL HAVE TO CONTINUE
TO MONITOR TRENDS TO SEE IF WE NEED TO EXPAND THE CURRENT DENSE FOG
ADVISORY MORE EAST. DEPENDING ON STRATUS SOME AREAS WILL NOT BE ABLE
TO SEE AN ALMOST TOTAL LUNAR ECLIPSE BY SUNRISE AND MOONSET. LATER
IN THE MORNING ANY SHALLOW FOG AND STRATUS SHOULD LIFT WITH SKIES
BECOMING SUNNY. SOUTHWEST WINDS WILL PICK UP A BIT TO 10 TO 15 MPH
WITH HIGHS FROM NEAR 40 OVER THE SNOW PACK IN THE FAR NORTHWEST FA
TO THE MID 40S ELSEWHERE.
FOR TONIGHT AN UPPER LEVEL DRY SHORTWAVE TROUGH MOVES THROUGH THE
PLAINS. A LEE TROUGH DEEPENS BY MORNING IN THE LEE OF THE ROCKIES
WITH A TIGHTENING PRESSURE GRADIENT OVER WESTERN KANSAS. SOUTH WINDS
SHOULD STAY MIXED IN THE 10 TO 20 MPH RANGE. MODEL BUFFER SOUNDINGS
SHOW SOME SHALLOW GROUND FOG BUT WITH A WELL MIXED BOUNDARY LAYER DO
NOT EXPECT STRATUS AT THIS TIME. WILL GO WITH LOWS FROM AROUND 20
FAR NORTHWEST TO THE MID 20S ELSEWHERE IN THE FA.
FOR SUNDAY WE TRANSITION TO SOUTHWEST UPPER LEVEL FLOW OVER THE
PLAINS WITH A 60 TO 70 KNOT JET OVER THE COLORADO ROCKIES. THE
STRONG FLOW WILL INDUCE A DEEPENING LEE LOW AND AN INCREASING
SURFACE PRESSURE GRADIENT OVER WESTERN AND CENTRAL KANSAS. BY MID TO
LATE MORNING AS MIXING OCCURS SOUTH WINDS WILL PICK UP TO 25 TO 35
MPH AND THIS MAY BE CLOSE TO A WIND ADVISORY. ALSO HIGHER DEWPOINTS
INTO THE MID 30S MOVE INTO WESTERN KANSAS. BUFFER SOUNDINGS SHOW LOW
LEVEL MOISTURE DEPTH INCREASING WITH STRATUS DEVELOPING IN THE
AFTERNOON. WILL SLOWLY INCREASE CLOUDS TO MOSTLY CLOUDY BY LATE
AFTERNOON. HIGH TEMPERATURES WILL BE TRICKY IF STRATUS DEVELOPS
HOWEVER STRONG MIXING MAY OFFSET THE STRATUS. FOR NOW WILL KEEP
HIGHS IN THE LOW TO MID 40S GOING.
ON SUNDAY NIGHT AN UPPER LEVEL JET MOVES OVER KANSAS WITH A LEE
TROUGH PUSHING A BIT EAST INTO EXTREME SOUTHWESTERN KANSAS. BUFFER
SOUNDINGS SHOW A SATURATED MOIST BOUNDARY LAYER UP TO AROUND 850MB
ALONG WITH SOUTH WINDS OF 15 TO 25 MPH. WINDS WILL BE LOWER CLOSER
TO THE TROUGH IN FAR SOUTHWEST KANSAS. ALSO HIGH CLOUDS WILL BECOME
THICKER TOWARDS MORNING. WILL GO WITH INCREASING CLOUDS WITH MOST OF
THE FA UNDER STRATUS EXCEPT FOR THE FAR WEST. LOWS WILL BE AROUND 30
FAR WEST TO THE MID TO UPPER 30S EAST WITH GOOD MIXING AND LOW
CLOUDS.
DAYS 3-7...
MEDIUM RANGE MODELS INDICATE AN UPPER LEVEL TROUGH OF LOW PRESSURE
PUSHING ASHORE IN EXTREME SOUTHERN CALIFORNIA MONDAY NIGHT INTO
TUESDAY BRINGING THE POSSIBILITY FOR PRECIP TO CENTRAL AND PORTIONS
OF WESTERN KANSAS LATE TUESDAY INTO WEDNESDAY. AS THE TROUGH ALOFT
APPROACHES, THE GEM, GFS, AND ECMWF SHOW A STRONG +130KT UPPER LEVEL
JET DEVELOPING ACROSS THE SOUTH PLAINS OF FAR WEST TEXAS NORTHEAST
INTO WESTERN KANSAS BY TUESDAY EVENING. MEANWHILE, AMPLE LOW LEVEL
MOISTURE IS PROJECTED TO NOSE NORTHWARD INTO SOUTH CENTRAL AND
PORTIONS OF SOUTHWEST KANSAS DURING THE DAY TUESDAY WITH H85
DEWPOINTS NEAR TO JUST ABOVE 5C. ALONG WITH STRONG UPPER LEVEL
DYNAMIC SUPPORT INCREASING, SURFACE LOW PRESSURE IS EXPECTED TO
DEVELOP GENERALLY IN EAST CENTRAL TO SOUTHEASTERN COLORADO BY
TUESDAY EVENING. COMBINED WITH SURFACE HIGH PRESSURE SET UP IN THE
EASTERN CONUS, THIS WILL HELP INCREASE LOW LEVEL FORCING ACROSS THE
CENTRAL PLAINS. AS A RESULT, RAIN WILL BE POSSIBLE IN SOUTH CENTRAL
KANSAS WHERE AVAILABLE MOISTURE WILL BE BEST WITH LESSER CHANCES
EXTENDING WEST INTO SOUTHWESTERN KANSAS. ISOLATED THUNDER CANNOT
BE COMPLETELY RULED OUT FOR FAR EASTERN PORTIONS OF THE CWA ON
WEDNESDAY.
TEMPERATURES WILL BE AT LEAST SEASONAL IF NOT SLIGHTLY ABOVE ON
MONDAY AS SURFACE LOW PRESSURE SET UP JUST OUR WEST AND SOUTHWEST
CONTINUES TO INFLUENCE MARGINAL WARM AIR ADVECTION INTO WESTERN
KANSAS. THE GEM, GFS, AND ECMWF SHOW H85 TEMPERATURES AROUND 2C TO
4C ACROSS THE CWA BY MONDAY AFTERNOON WITH THE WARMEST TEMPERATURES
IN OUR SOUTH. SHOULD SEE HIGHS UP INTO THE 40S(F) ACROSS THE
FORECAST AREA WITH LOWER TO MID 50S(F) POSSIBLE IN OUR SOUTHEAST.
&&
.AVIATION...
DEVELOPING LOW LEVEL STRATUS/FOG WILL SPREAD NORTHEAST ACROSS
SOUTHWEST KANSAS EARLY THIS MORNING LOWERING CIGS DOWN TO IFR
CONDITIONS. AREAS OF FREEZING FOG WILL SPREAD NORTHEAST ACROSS THE
SAME GENERAL AREA LOWERING VSBYS DOWN TO A QUARTER MILE OR LESS IN
THE VICINITY OF KGCK AND KDDC BY SUNRISE WITH LOW VSBYS POSSIBLY
REACHING AS FAR NORTHEAST AS KHYS LATER THIS MORNING. IFR CIGS/VSBYS
ARE EXPECTED TO PERSIST THROUGH LATE MORNING BEFORE CONDITIONS BEGIN
TO IMPROVE WEST TO EAST ACROSS THE FORECAST AREA BY THIS AFTERNOON.
A LEE SIDE TROUGH WILL CONTINUE TO STRENGTHEN ACROSS EASTERN
COLORADO TODAY INFLUENCING SOUTH TO SOUTHWESTERLY WINDS 10 TO
20KT THROUGH TONIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 45 25 45 36 / 0 0 0 10
GCK 44 24 44 32 / 0 0 0 0
EHA 44 25 44 28 / 0 0 0 0
LBL 44 25 45 34 / 0 0 0 0
HYS 42 24 44 34 / 0 0 0 10
P28 46 26 47 37 / 0 0 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 9 AM CST /8 AM MST/ THIS MORNING FOR
KSZ030-031-043>046-061>065-075>080-085>088.
&&
$$
FN06/32/32
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1116 PM CST FRI DEC 9 2011
.UPDATE...
.AVIATION... /FOR THE 06Z TAF ISSUANCE/
TERMINAL AERODROME FORECASTS PRESENT A SIGNIFICANT CHALLENGE THIS
EVENING AS THE ACTUAL EXTENT OF THE CURRENT DEVELOPING FOG IS
LARGELY UNCERTAIN. A LARGE AREA OF EXPANDING FOG NEAR EXISTS
THROUGH THE ARKANSAS AND SMOKY HILL VALLEYS, AND LIFR/VLIFR FOG
CATEGORIES MAY BE LIKELY AT GARDEN CITY WITHIN THE NEXT 3-4 HOURS.
WE HAVE MUCH LESS CERTAINTY AT HAYS AND DODGE CITY AS THE NAM
CONFLICTS WITH THE VERY AGGRESSIVE RUC RAPID REFRESH MODEL WHICH
ENVELOPES THE ENTIRE FORECAST AREA IN DENSE FOG BY SATURDAY MORNING.
MOST PESSIMISTIC CONDITIONS WILL BE FORECAST AT GARDEN CITY IN THE
CRITICAL TAF PERIOD. - RUSSELL
&&
.PREV DISCUSSION... /ISSUED 1036 PM CST FRI DEC 9 2011/
UPDATE...
WE HAVE HOISTED A DENSE FOG ADVISORY GENERALLY ALONG AND WEST OF
THE HIGHWAY 83 CORRIDOR THROUGH 15Z. THIS IS BASED ON CURRENT
TRENDS AS WELL AS MODEL TRENDS OF THE OVERNIGHT. DENSE FREEZING
FOG HAS DEVELOPED THROUGH THE ARKANSAS RIVER VALLEY OF KEARNEY
COUNTY THROUGH SYRACUSE, AND IS EXPANDING NORTHWARD THROUGH THE
SMOKY HILL VALLEY. FOLLOWING THE TRENDS OF THE NAM AND HRRR,
VISIBILITIES PROBABLY WILL RAPIDLY DROP SOUTHWARD AS WELL TO THE
PANHANDLE BY MIDNIGHT. EXPANSION OF THE ADVISORY EASTWARD MAY ALSO
BE NEEDED OVERNIGHT IF FOG EXPANDS FARTHER EAST WHICH IS WHAT
THE VERY AGGRESSIVE RAPID UPDATE INDICATES (AN OUTLIER TO THE
LESS AGGRESSIVE NAM). -RUSSELL
PREV DISCUSSION... /ISSUED 351 PM CST FRI DEC 9 2011/
SYNOPSIS...
CURRENTLY...SKIES ARE MOSTLY CLEAR WITH THE EXCEPTION OF ALONG THE
OKLAHOMA BORDER WHERE A FEW LOW CLOUDS REMAIN FROM THIS MORNING.
WINDS ARE GENERALLY FROM THE NORTHWEST AT 5 TO 10 MPH. TEMPERATURES
ARE IN THE LOWER TO MID 30S WITH THE EXCEPTION OF THE SOUTHWEST
CORNER OF THE CWA WHERE UPPER 20S ARE FOUND. THE CURRENT WEATHER
PICTURE CONSISTS OF AN UPPER LEVEL TROUGH ACROSS THE GREAT LAKES
EXTENDING SOUTHEAST ACROSS THE CENTRAL PLAINS AND AN UPPER LEVEL
HIGH ACROSS THE WESTERN UNITED STATES. HIGH PRESSURE IS FOUND ACROSS
THE NORTHERN PLAINS AT THE SURFACE WITH IT`S RIDGE AXIS EXTENDING
SOUTHWARD ACROSS THE HIGH PLAINS. INFORMATION FROM THIS MORNING`S
SOUNDING SHOW A SATURATED LAYER FROM THE SURFACE TO AROUND 850 MB
THEN BECOMES VERY DRY ABOVE THAT LAYER. THE SOUNDING ALSO SHOWS
NORTHERLY WINDS AT THE SURFACE SHIFTING TO THE WEST IN THE MID AND
UPPER PARTS OF THE ATMOSPHERE.
DISCUSSION...
DAYS 1-2...
THE SURFACE RIDGE OF HIGH PRESSURE MENTIONED IN THE SYNOPSIS WILL
MOVE EAST TODAY INTO TONIGHT SHIFTING NORTHERLY WINDS TO THE
SOUTHWEST BY TOMORROW MORNING. BEFORE TOMORROW MORNING...WINDS
SHOULD BECOME LIGHT AND VARIABLE OVERNIGHT ALLOWING FOR PATCHY FOG
TO REDEVELOP ACROSS WESTERN PORTIONS OF THE FORECAST AREA AFTER
MIDNIGHT. SOUTHWEST WINDS WILL INCREASE IN INTENSITY TOMORROW AS LEE
TROUGHING DEVELOPS ACROSS EASTERN COLORADO. SOUTHWEST WINDS CONTINUE
TOMORROW NIGHT INTO SUNDAY WITH BREEZY CONDITIONS EXPECTED SUNDAY
AFTERNOON. MOSTLY SUNNY SKIES AND DRY CONDITIONS SHOULD PREVAIL
THROUGH TOMORROW NIGHT DUE TO SURFACE HIGH PRESSURE TO OUR EAST AND
NORTHWEST FLOW ALOFT. CLOUDS ARE EXPECTED TO INCREASE ACROSS EASTERN
PORTIONS OF OUR FORECAST AREA ON SUNDAY AS MOISTURE FROM THE GULF OF
MEXICO ADVECTS NORTHWARD INTO CENTRAL KANSAS. LOWS TONIGHT ARE
ANTICIPATED TO BE IN THE UPPER TEENS TONIGHT THEN WARMING INTO THE
LOWER TO MID 20S TOMORROW NIGHT. HIGHS TOMORROW ARE EXPECTED TO BE
IN THE LOWER TO MID 40S WITH HIGHS IN THE MID TO UPPER 40S ON
SUNDAY.
DAYS 3-7...
AN ACTIVE WEATHER PATTERN WILL PERSIST THROUGH DECEMBER 19TH, WITH
A SERIES OF UPPER-LEVEL TROUGHS DROPPING SOUTHWARD INTO THE DESERT
SOUTHWEST AND THEN EJECTING NORTHEASTWARD ACROSS THE PLAINS. THIS
PATTERN WILL LEAD TO AMPLE GULF MOISTURE RETURN INTO THE SOUTHERN
AND CENTRAL PLAINS ALONG WITH PERIODIC CHANCES FOR PRECIPITATION.
ONE UPPER-LEVEL SYSTEM WILL MOVE SOUTHWARD TO JUST OFF THE
CALIFORNIA COAST BY MONDAY, PROGRESS INTO THE DESERT SOUTHWEST BY
TUESDAY, AND THEN EJECT ACROSS THE CENTRAL PLAINS ON WEDNESDAY.
AHEAD OF THIS SYSTEM THERE WILL BE A WEAK SURGE OF ARCTIC AIR THAT
WILL STALL OUT ACROSS NORTHERN OKLAHOMA OR SOUTHERN KANSAS. THIS
OUGHT TO SET UP A LOW-LEVEL THERMAL GRADIENT ACROSS OUR FORECAST AREA
BY TUESDAY MORNING. HAVING BEEN DRAWN INTO THE SOUTHERN AND CENTRAL
PLAINS SUNDAY AND MONDAY AHEAD OF A WEAKER UPPER-LEVEL DISTURBANCE,
LOW-LEVEL MOISTURE WILL BE PLENTIFUL BY TUESDAY. THEREFORE, AS MOIST
ISENTROPIC LIFT INCREASES WELL AHEAD OF THE UPPER-LEVEL SYSTEM ON
TUESDAY, WIDESPREAD STRATUS CLOUDS CAN BE EXPECTED ALONG WITH
INCREASING CHANCES FOR LIGHT RAIN AND DRIZZLE. THE EXACT
PLACEMENT OF THIS PRECIPITATION IS UNCERTAIN. THE 12Z SUITE OF
MODELS SHOW SURFACE TEMPERATURES ABOVE FREEZING EVEN AS FAR NORTH AS
INTERSTATE 70 BY TUESDAY AFTERNOON AS THE PRECIPITATION STARTS.
HOWEVER, SINCE THESE SHALLOW ARCTIC AIR INTRUSIONS ARE OFTEN
STRONGER THAN PROGGED, I WOULD NOT RULE OUT LIGHT FREEZING RAIN OR
FREEZING DRIZZLE ALONG THE INTERSTATE 70 CORRIDOR BY TUESDAY
AFTERNOON. EVEN THOUGH THE CENTRAL REGION COLLABORATED GRIDS
CURRENTLY SHOW UPPER 30S TO NEAR 40F NEAR WAKEENEY AND DIGHTON ON
TUESDAY AFTERNOON, DON`T BE TOO SURPRISED IF IT IS COLDER. RAIN
CHANCES WILL INCREASE BY TUESDAY NIGHT AND WEDNESDAY AS THE WARM
CONVEYOR BELT AHEAD OF THE UPPER-LEVEL SYSTEM BRINGS COPIOUS AMOUNTS
OF LOW-LEVEL MOISTURE INTO WESTERN KANSAS ALONG WITH MILDER
TEMPERATURES. SINCE THIS STRONG SYSTEM IS PROGGED TO BE SOMEWHAT
PROGRESSIVE AND PERHAPS EVEN A STRONG OPEN WAVE, THE CHANCES FOR
HEAVY RAINFALL LOOK LOWER IN FAR WESTERN KANSAS COMPARED TO
LOCATIONS FURTHER EAST SUCH AS STAFFORD, PRATT AND MEDICINE LODGE.
IN SIMPLIFIED TERMS, THIS IS DUE TO THE ALL TOO FAMILIAR RAIN SHADOW
EFFECT IN THE LEE OF THE ROCKIES. DEPENDING ON THE EXACT TRACK OF
THE SYSTEM AND ASSOCIATED FRONTAL PLACEMENTS, A WIDE RANGE OF HIGH
TEMPERATURES ARE POSSIBLE ON WEDNESDAY FROM THE 40S UP TO THE 60S.
THERE IS TREMENDOUS UNCERTAINTY IN THE EVOLUTION OF THE LARGE SCALE
PATTERN ACROSS THE EASTERN PACIFIC AND NORTH AMERICA AFTER
WEDNESDAY. AND THERE IS LITTLE CONSISTENCY FROM MODEL TO MODEL AND
FROM MODEL RUN TO MODEL RUN. HOWEVER, DESPITE ALL OF THESE
DIFFERENCES, THERE IS STILL A GENERAL THEME THAT CAN BE GLEANED
AMID ALL THE NOISE. THIS THEME SHOWS RENEWED UPPER-LEVEL TROUGHING
ACROSS THE SOUTHWESTERN UNITED STATES BY SATURDAY, A COLD SURGE DOWN
THE PLAINS AHEAD OF THE SYSTEM, AND ABUNDANT LOW-LEVEL MOISTURE
ADVECTING NORTHWARD FROM THE GULF OF MEXICO. SO PRECIPITATION
CHANCES WILL BE ON THE INCREASE BY SATURDAY INTO MONDAY. THERE IS FAR
TOO MUCH UNCERTAINTY TO DETERMINE WHETHER ENOUGH WARM AIR WILL SURGE
INTO WESTERN KANSAS BEFORE ANY PRECIPITATION STARTS TO PRECLUDE FROZEN
PRECIPITATION.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 19 44 25 45 / 0 0 0 10
GCK 17 42 23 44 / 0 0 0 0
EHA 22 44 26 44 / 0 0 0 0
LBL 19 44 24 45 / 0 0 0 10
HYS 15 41 25 44 / 0 0 0 10
P28 18 46 27 46 / 0 0 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 9 AM CST /8 AM MST/ SATURDAY FOR KSZ043-
044-061>063-074>076-084>086.
&&
$$
FN99/99
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
139 AM EST SAT DEC 10 2011
.SYNOPSIS...
A COLD FRONT MOVES ACROSS THE AREA LATE TONIGHT...THEN OFF THE
COAST SATURDAY MORNING. HIGH PRESSURE BUILDS IN FROM THE WEST
SATURDAY AFTERNOON...THEN SETTLES ACROSS THE AREA SATURDAY NIGHT
AND SUNDAY. A TROUGH OF LOW PRESSURE WILL DEVELOP OFF THE SOUTHEAST
COAST MONDAY AND TUESDAY. HE HIGH SLOWLY MOVES OFF TO THE
NORTHEAST.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
FIRST WAVE OF SHWRS NOW MOVG NE ALONG ERN SHORE AREAS. SECOND WAVE
OF SHWRS MOVG NE FROM ERN NC AND BOTH RUC AND WRF MODELS HAVE THESE
MOVG NE ALONG VA / MD CSTL SCTNS THRU THE OVERNIGHT HRS. ALL THIS
AHEAD OF STRNG CDFRNT PROGGED TO PUSH THE LOW OFFSHORE SAT MORNING.
UPDATE WAS TO BUMP UP CLOUD COVERAGE TO M CLDY W AND CLDY E. KEPT
CHC POPS ALONG CSTL COUNTYS WITH A BUFFER ZONE OF SLGHT CHC POPS W
OF CHES BAY GIVEN CRNT RADAR TRENDS AND MODEL TRENDS.
UPR JET STRENGTHENS LATE TONITE AS THE MID/UPPER LEVEL FLOW AMPLIFIES
ACRS THE GREAT LAKES. THIS HELPS LOW PRESSURE DEEPEN OFF THE COAST
EARLY SAT...AND MAY SEE SOME LINGERING SHOWERS INTO SAT MORNING (MAINLY
ALONG THE COAST). DEEP MSTR WILL NOT BE PRESENT ABOVE -10C...SO QPF
AMOUNTS OF A FEW HUNDREDS PSBL. LOWS STAY ABOVE FREEZING...MAINLY IN
THE M30S-M40S. XCPTN BEING FROM ARND LKU-FVX WHERE IT MAY DROP TO 32
BY SUNRISE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY/...
HAVE SLOWED DOWN THE CLEARING SKY A BIT ON SAT AS LOW LEVEL FLOW
IS MORE N RATHER THAN NW. OVERALL...EXPECT MOSTLY CLOUDY SKIES IN
THE EAST IN THE MORNING...BECOMING PARTLY SUNNY IN THE AFTN
(CLEARING EARLIER ALONG/W OF I-95). HIGHS MAINLY IN THE UPPER 40S
TO LOWER 50S.
SAT NIGHT-MON...MODELS IN GOOD AGREEMENT WITH STRONG MODIFIED
ARCTIC (1035-1040 MB) SFC HIGH PRESSURE BECOMING CENTERED FROM THE
OHIO VALLEY INTO THE MID ATLC STATES SAT NIGHT THROUGH SUNDAY.
THIS WILL BRING A COLD AND VERY DRY AIRMASS INTO THE REGION...LOWS
SAT NIGHT INTO THE 20S OVER MOST AREAS..30S ALONG THE COAST. SUNNY
AND COLD SUNDAY WITH HIGHS IN THE 40S ALL AREAS. AS HIGH RETREATS
NE ON MON...COULD SEE SOME INCREASING CLOUDS/MSTR W/ SFC TROUGH
DEVELOPING OFF THE SE COAST. FOR NOW...KEEPING IT PARTLY SUNNY AND
CONTINUED COOL WITH HIGHS IN THE 40S TO LWR 50S.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
THE EXTENDED PERIOD BEGINS MONDAY NIGHT AND TUESDAY WITH MID-LEVEL
RIDGING OVER THE GULF COAST AND SOUTHEAST...WITH SURFACE HIGH
PRESSURE ANCHORED OVER THE MID ATLANTIC REGION. THIS SHOULD PRODUCE
DRY CONDITIONS AND SEASONAL TEMPERATURES ACROSS THE LOCAL AREA. A
WEAK DRY COLD FRONT IS EXPECTED TO PASS ACROSS THE AREA TUESDAY
NIGHT FOLLOWED BY A RETURN OF HIGH PRESSURE WEDNESDAY. ANY
TEMPERATURE CHANGE BEHIND THIS FRONT APPEARS MINIMAL AT THIS POINT.
A WARMING TREND IS EXPECTED TOWARD THE END OF NEXT WEEK AHEAD OF A
COLD FRONT THAT SLOWLY SAGS TOWARD THE AREA FROM THE NORTHWEST. THE
CHANCE OF RAIN WITH THIS FRONT APPEARS VERY LOW AT THIS TIME.
&&
.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
PREDOMINATE VFR CONDITIONS ACROSS TERMINALS THIS MORNING. WEAK
PREFRONTAL SURFACE TROUGH OVER EASTERN VA AND NC...ALONG WITH A
WEAK LOW OFF THE NC COAST...ARE HELPING TO PRODUCE MVFR STRATUS
AND STRATOCU CLOUDS ALONG THE COASTAL AREAS UP THRU THE EASTERN
SHORE...WITH SOME SCT SHRAS/MVFR CONDS ACROSS SE COASTAL SITES. A
COLD FRONT TO THE WEST HAS STARTED TO MAKE SOME HEADWAY INTO
WESTERN VA EARLY THIS MORNING AND WILL PASS OFF THE COAST BY
SUNRISE. LOOK FOR A NW WIND SHIFT AND SOME GUSTY NNW WINDS LATER
TODAY THROUGH 20-22Z OR SO. OTHERWISE...BUILDING SFC HIGH
PRESSURE AND VFR CONDITIONS EXPECTED ACROSS THE TAF SITES.
OUTLOOK: HIGH PRESSURE OVER THE REGION WILL ALLOW FOR DRY WX AND VFR
WX FOR TONIGHT THROUGH THE MIDDLE OF NEXT WEEK.
&&
.MARINE...
A WEAK AREA OF LOW PRESSURE MOVES UP THE COAST TONIGHT AHEAD OF A
COLD FRONT APPROACHING FROM THE NORTHWEST. THE COLD FRONT CROSSES
THE COAST LATE TONIGHT FOLLOWED BY A STEADY CAA SURGE SLOWLY
TAPERING OFF N-S LATE SATURDAY INTO EARLY SUNDAY...WITH SEAS
REMAINING AROUND 5 FT INTO SUNDAY AFTERNOON. INHERITED (LOW-END
CRITERIA) SCA FLAGS FOR THIS SURGE REMAIN ON TRACK. SURFACE HIGH
PRESSURE STEADILY BUILDS ACROSS THE NORTHERN MID ATLANTIC THROUGH
EARLY NEXT WEEK AS LOW PRESSURE LINGERS OVER THE SUBTROPICAL WESTERN
ATLANTIC. THIS WILL MAINTAIN NNE FLOW ACROSS THE LOCAL AREA WITH THE
STRONGEST SPEEDS (AROUND 15 KT) S. SEAS WERE CAPPED AROUND 4 FT AT
THIS POINT...BUT THE FLOW PATTERN COULD KEEP SEAS AROUND 5 FT OFF
THE NC OUTER BANKS.
&&
.HYDROLOGY...
FLOOD WARNINGS REMAIN IN EFFECT FOR JAMES RIVER AT WESTHAM (MODERATE
FLOODING) AND RICHMOND CITY LOCKS (MINOR FLOODING). SEE FLSAKQ FOR
DETAILS.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM THIS MORNING TO 4 PM EST SUNDAY
FOR ANZ634.
SMALL CRAFT ADVISORY FROM 6 AM THIS MORNING TO 1 PM EST SUNDAY
FOR ANZ631-632.
SMALL CRAFT ADVISORY FROM 6 AM THIS MORNING TO 6 PM EST SUNDAY
FOR ANZ633-650-652-654.
SMALL CRAFT ADVISORY FROM 6 AM THIS MORNING TO 6 PM EST THIS
EVENING FOR ANZ630.
SMALL CRAFT ADVISORY FROM 9 AM THIS MORNING TO 6 PM EST SUNDAY
FOR ANZ656-658.
&&
$$
SYNOPSIS...LKB
NEAR TERM...MPR
SHORT TERM...LKB
LONG TERM...AJZ
AVIATION...MAM/JEF
MARINE...AJZ/JEF
HYDROLOGY...
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
629 PM EST SUN DEC 11 2011
UPDATED AVIATION DISCUSSION FOR 00Z TAFS
.SYNOPSIS...
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A SPLIT FLOW ACRS
NAMERICA WITH NRN BRANCH RDGING BLDG INTO THE UPR GRT LKS. THESE
RISING HGTS...WITH 00Z-12Z H3 RISES UP TO 150M AT APX...ARE BEING
FORCED BY VIGOROUS WAD IN THE STRONG WSW FLOW /12Z H85 WIND SPEED AT
INL WAS 50KT/ BTWN SFC-H85 HI PRES IN THE MID ATLANTIC STATES AND LO
PRES JUST N OF THE BORDER MOVING E INTO NW ONTARIO THAT IS
ASSOCIATED WITH A SHRTWV NEAR LK WINNIPEG. THIS STRONG WAD HAS
PUSHED H85 TEMPS IN THE UPR MS VALLEY/GREAT LKS TO UNSEASONABLY HI
LVLS...WITH 12Z H85 TEMPS AT INL/MPX UP TO 7C VS 0C AT APX AND 3C AT
GRB TOWARD THE RETREATING COLD AIR. LO CLDS OVER THE E HALF OF THE
CWA THAT FORMED AS THIS WARMER AIR PUSHED OVER MORE RESILIENT NEAR
SFC COLD AIR IN THE PRESENCE OF RADIATIONAL COOLING LAST NGT ARE
ONLY GRDLY DISSIPATING EARLY THIS AFTN. OTRW...THE OVERALL DRYNESS
OF THE LOCAL 12Z RAOBS IS ALLOWING A MOSUNNY DAY. BUT MORE LO CLDS
ARE PUSHING NEWD THRU IOWA TOWARD THE UPR MIDWEST IN THE SW LLVL
FLOW ARND THE HI IN THE MID ATLANTIC. A DISTURBANCE IN THE SRN
BRANCH FLOW IS NOW IN KANSAS AND MOVING NEWD AS WELL.
&&
.SHORT TERM DISCUSSION /TNGT AND MON/...
MAIN FCST CONCERNS THIS PACKAGE ARE LO CLD TRENDS AND THE POTENTIAL
FOR MIXED PCPN ON MON AS DISTURBANCE NOW IN KANSAS RIDES TO THE NE.
TNGT...EXPECT THE LINGERING LO CLDS OVER THE E TO BE GONE BY FCST
ISSUANCE...WITH MOCLR SKIES/WELL ABV NORMAL TEMPS DOMINATING.
ALTHOUGH THE LO CLDS HEADING NE FM IOWA ARE LIKELY TO MIX OUT WITH
DAYTIME TEMPS RISING INTO THE 30S/40S THIS AFTN...EXPECT THE ST/SC
TO REDVLP WITH LOSS OF DAYTIME HEATING AFT SUNSET. 12Z MODEL
GUIDANCE SHOWS THE HIER LLVL RH ARRIVING NEAR THE WI BORDER W OF IMT
THIS EVNG...SO EXPECT EXPANDING LO CLDS SW-NE. THE COMBINATION OF
THE LO CLDS/STEADY SW FLOW OF MILD AIR WL GREATLY REDUCE DIURNAL
FALL OF TEMPS...BUT MIN TEMPS WL STILL FALL BLO 32 EVERYWHERE.
LOCATIONS NEAR LK SUP WHERE THE SW FLOW DOWNSLOPES WL BE WARMEST.
OPTED TO RETAIN MENTION OF SOME -FZDZ OVER THE INTERIOR W LATE AWAY
FM THE DOWNSLOPING NEAR LK SUP AS SHALLOW MSTR INFLUX GROWS A BIT
DEEPER WITH SOME DPVA/OMEGA/DEEPER MSTR ADVCTN AHEAD OF APRCHG
KANSAS SHRTWV. BUT SINCE THE HIER RH WL REMAIN WELL BLO THE DGZ AND
STILL BE RELATIVELY SHALLOW /BLO ABOUT H85/...ANY PCPN SHOULD REMAIN
IN THE FORM OF SMALL WATER DROPLETS.
MON...COMBINATION OF ARRIVAL OF LO PRES TROF ATTENDANT TO SHRTWV/SFC
LO NOW IN NW ONTARIO...DEEPER MSTR FM THE SW...AND SHRTWV NOW IN
KANSAS/ACCOMPANYING DYNAMICS WL RESULT IN EXPANDING PCPN CHCS. THE
12Z NAM/GFS/LOCAL WRF-ARW RUNS ALL EXHIBIT THE HIEST QPF UP TO ARND
0.20 INCH OVER THE SE CWA...WHERE GFS SHOWS AN AXIS OF SHARPER H85-7
FGEN AND THE ALL MODELS INDICATE DEEPER MSTR/OMEGA EXTENDING THRU
THE DGZ. SO OPTED TO RETAIN GOING LIKELY POPS IN THIS AREA. PTYPE WL
BE A SGNFT CONCERN. SUSPECT ONLY -FZDZ/FLURRIES WL BE ARND EARLY
WITH RELATIVELY SHALLOW MSTR YET...BUT EITHER RA...SN...OR A MIX IS
MORE LIKELY BY THE AFTN AT LEAST OVER OVER THE SE HALF WITH DEEPER
MSTR/LARGER PCPN PARTICLES. FOR THE PAST SEVERAL RUNS...THE NAM HAS
BEEN WARMEST WITH LLVL TEMPS AND THUS INDICATES RA WL BE THE
PREDOMINANT PTYPE AT LEAST OVER THE SE. THE 12Z CNDN MODEL SUPPORTS
THIS WARMER RUN AS WELL. ALTHOUGH THE UNSEASONABLE WARMTH TDAY WOULD
SUG THESE MODELS ARE ON THE RIGHT TRACK...RELATIVELY DRY NATURE OF
THE AIRMASS/POTENTIAL FOR EVAP COOLING HINTS THE COOLER GFS/WRF-ARW/
09Z SREF ARE ON THE RIGHT TRACK. BLENDED IN THAT DIRECTION FOR LLVL
TEMPS FIELDS FOR NOW TO DETERMINE PTYES.
.LONG TERM /00Z TUESDAY THROUGH NEXT SUNDAY/...
MAIN FOCUS FOR THE EXTENDED IS WITH PTYPES AND CHANCES FOR FREEZING
PRECIP FROM MON NIGHT THROUGH WED MORNING...THEN WITH A SYSTEM
MOVING THROUGH WED NIGHT/THU.
A SFC TROUGH/FRONT WILL BE STALLED OVER UPPER MI FROM THE CENTRAL
PLAINS FROM THE START OF THE PERIOD MON NIGHT...THROUGH TUE. A WEAK
UPPER WAVE WILL BE MOVING THROUGH THE ERN CWA PRIOR TO 06Z
TUE...PRODUCING SOME RAIN EAST. THE HARDEST PART OF THIS FORECAST
PERIOD IS THAT SHALLOW MOISTURE WILL EXIST ALONG AND SOUTH OF THE
FRONT...WITH DRY MID LEVELS KEEPING ICE CRYSTALS FROM FORMING. THE
TEMP PROFILE WILL BE SUB-FREEZING THROUGH WEDNESDAY MORNING /EXCEPT
NEAR SFC TEMPS DURING THE DAY TUE/...WHICH WILL KEEP PRECIP WITH THE
DEEPER MOISTURE AND LIFT OVER THE EAST MON NIGHT AS SNOW...AND
DRIZZLE/FREEZING DRIZZLE DIFFERENTIATION ELSEWHERE WILL BE DEPENDENT
ON SFC TEMPS. AT THIS POINT...IT LOOKS LIKE THERE IS POTENTIAL FOR
UP TO A TENTH OF AN INCH OF ICE ACCUMULATION FROM 00Z TUE INTO TUE
MORNING...MAINLY OVER THE WEST HALF OF UPPER MI. SOME UNCERTAINTY
STILL EXISTS WITH HOW MUCH FREEZING DRIZZLE WILL FALL...AND WHERE
THE HEAVIEST AMOUNTS WILL BE.
ATTENTION THEN TURNS TO THE NEXT SYSTEM MOVING IN AS AN UPPER TROUGH
FROM CENTRAL CANADA EXTENDS OVER THE PLAINS AT 00Z THU...MOVES
ACROSS UPPER MI THU...THEN INTO QUEBEC FRI NIGHT. MODELS SEEM TO BE
COMING INTO BETTER AGREEMENT WITH THIS SYSTEM BUT THERE ARE STILL
SOME BIG DIFFERENCES BETWEEN THEM...AND THOSE DIFFERENCES PLAY A
HUGE ROLE IN THE FORECAST. THE GEM AND NAM LOOK ANOMALOUS WITH THE
SYSTEM...SO THEY WERE NOT USED. THE 11/00Z ECMWF...WHICH HAS SHOWN
BETTER RUN TO RUN CONTINUITY THAN THE GFS...HAS A DEEPER UPPER WAVE
CO-LOCATED WITH THE CLOSED SFC LOW THAN THE GFS. THE MAIN DIFFERENCE
BETWEEN THE MODEL STEMS FROM THE STRENGTH OF THE UPPER TROUGH MOVING
IN...WHICH LEADS TO /AMONG OTHER THINGS/ TIMING DIFFERENCES IN THE
LOW LEVELS. THE 11/12Z GFS BRINGS THE SFC LOW INTO THE CWA AROUND
06Z THU...WHILE THE 11/00Z ECMWF LAGS UNTIL AROUND 15Z THU. BOTH
MODELS BRING IN MID LEVEL TEMPS THAT WOULD LEAD TO LIQUID PRECIP
UNTIL THE LOW PASSES AND COLDER AIR COMES IN. SFC TEMPS WED NIGHT
WILL FALL TO AROUND 30F OVER THE WEST HALF OF UPPER MI...BUT SHOULD
STAY NEAR OR ABOVE FREEZING OVER THE EAST HALF. TEMPS OVER THE W
LOOK TO STAY NEAR OR ABOVE FREEZING THROUGH AROUND 03Z THU...AND
STAY THERE UNTIL MID TO LATE MORNING THU. THE GFS BRING THE BULK OF
THE SYNOPTIC QPF /EASILY GREATER THAN 0.25 INCHES IN SOME SPOTS FROM
BOTH THE ECMWF AND GFS/ BETWEEN 00Z AND 12Z THU...WHILE THE ECMWF IS
BETWEEN 12Z AND 18Z THU...SO REGARDLESS OF MODEL THERE IS POTENTIAL
FOR SIGNIFICANT FREEZING RAIN IF ALL THE INGREDIENTS COME TOGETHER.
IT NEEDS TO BE STRESSED AGAIN THAT THERE IS STILL A CONSIDERABLE
AMOUNT OF UNCERTAINTY WITH THIS SYSTEM...ESPECIALLY WITH THE SMALL
SCALE DETAILS NEEDED FOR FREEZING RAIN. DUE TO THE POTENTIAL FOR
SIGNIFICANT FREEZING RAIN ACCUMULATIONS...PAY EXTRA ATTENTION AND
KEEP UP TO DATE WITH LATER FORECASTS ON THIS SYSTEM.
MODELS ARE IN DECENT GENERAL AGREEMENT FROM FRI THROUGH SUN. NW
WINDS AND 850MB TEMPS FALLING TO AOB -12C BY AT LEAST 12Z FRI WILL
MAKE FOR POTENTIAL FOR LES...BUT DRY AIR IS ALSO MOVING IN. A SFC
RIDGE WILL MOVE THROUGH SAT AFTERNOON AND EAST BY LATE
SAT...BRINGING SWLY WINDS. SW FLOW BEHIND THE DEPARTING HIGH E AND
LOW PRESSURE W...ALONG WITH AN UPPER RIDGE BUILDING IN FROM THE
W...WILL LEAD TO 850MB TEMPS INCREASING TO AOA 0C BY LATE SUNDAY.
&&
.AVIATION /FOR THE 00Z TAF ISSUANCE/...
LLWS TO END OVER THE WESTERN TAF SITES AS APPROACHING TROUGH RELAXES
THE PRESSURE GRADIENT. LLWS TO PERSIST AT KSAW PAST 6Z UNTIL TROUGH
MOVES CLOSER THERE. VFR CONDITIONS THIS EVENING TO GIVE WAY TO
IFR/MVFR CONDITIONS OVERNIGHT AS SURGE OF LOW LEVEL MOISTURE MOVES
IN FROM THE SOUTHWEST. SOME FREEZING DRIZZLE POSSIBLE AT ALL THREE
TAF SITES BY MONDAY MORNING. A WINTRY MIX WILL PREVAIL OVER KIWD
AND KCMX WITH PERIODS OF DRIZZLE AND LIGHT SNOW THROUGH THE
AFTERNOON. WITH A SLIGHTLY WARMER TEMPERATURE PROFILE AND BETTER
FORCING NEARBY...KSAW SHOULD SEE -RASN THROUGH THE AFTERNOON. -FZDZ
MAY REAPPEAR AT ALL THREE SITES AFTER 21Z MONDAY BUT HAVE LEFT THIS
OUT OF THE TAFS FOR NOW.
&&
.MARINE /FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE/...
EXPECT SW WINDS UP TO 30 KTS LATE THIS AFTN TO DIMINISH TONIGHT WITH
THE APPROACH OF A LO PRES TROF AND WEAKER PRES GRADIENT. ALTHOUGH
THERE WILL BE A WSHFT TO THE N FOLLOWING THE PASSAGE OF THIS TROF ON
MON...RELATIVELY LIGHT WINDS UNDER 20 KTS WILL PERSIST INTO WED BUT
SLOWLY VEER TO THE S AS A LO PRES SYSTEM DEVELOPING IN THE PLAINS
BEGINS TO MOVE NE TOWARD THE UPPER GREAT LKS. SE WINDS AHEAD OF THIS
LO MAY INCREASE TO 25 KTS ESPECIALLY OVER THE E HALF. THE MAIN
HAZARD WILL BE AFTER THE LO MOVES TO THE NE ON THU...WHEN NW GALES
IN ITS WAKE ENHANCED BY THE ARRIVAL OF VERY COLD AIR/MIXING WILL
PREVAIL. EXPECT THESE STRONG WINDS TO DIMINISH ON FRI WITH THE SLOW
APPROACH OF HI PRES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...KC
SHORT TERM...KC
LONG TERM...TITUS
AVIATION...RJT
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
313 PM EST SAT DEC 10 2011
.SYNOPSIS...
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW PROGRESSIVE WRN
RDG/ERN TROF PATTERN OVER NAMERICA. 12Z H85 TEMPS RANGE FM -18C AT
APX TO 7C AT GLASGOW MT. STRONG SFC-H85 SW FLOW OVER THE NRN PLAINS/
UPR MS RIVER VALLEY BTWN HI PRES IN THE OH VALLEY AND LO PRES NEAR
LK WINNIPEG IS CAUSING WAD AND ALLOWING THE UPR RDG TO BUILD TO THE
E PER 00Z-12Z 100-200M H3 HGT RISES OBSVD TO THE E OF THE UPR RDG
AXIS. THE BACKING LLVL FLOW TO SW OVER THE CWA HAS PUSHED THE SHSN
THAT WERE IMPACTING THE KEWEENAW AND AREAS E OF MUNISING OUT INTO
THE OPEN LK. THE STRONG WAD HAS ALSO CAUSED AN EXPANSIVE AREA OF MID
CLD STRETCHING FM LK WINNIPEG INTO THE UPR GRT LKS/UPR MS VALLEY
WELL APPROXIMATED BY THE HIER RH DEPICTED FM H8-6 ON THE 12Z INL
RAOB AND ON THE NAM 285K ISENTROPIC SFC. HOWEVER...DRY NATURE OF THE
LLVLS PER LARGE SFC-H85 DWPT DEPRESSIONS AND UPSTREAM 12Z RAOBS AS
WELL AS LACK OF ANY OTHER FORCING MECHANISM UNDER THE UPR HGT RISES
IS PREVENTING ANY PCPN EXCEPT OVER FAR NE MN. FARTHER TO THE W...THE
ADVECTION OF MUCH WARMER AND DRIER AIR SHOWN ON THE 12Z BISMARCK
RAOB IS PUSHING THE WRN EDGE OF THE MID CLD STEADILY TO THE E THRU
MN.
&&
.SHORT TERM DISCUSSION /TNGT AND SUN/...
MAIN FCST CONCERNS DURING THIS RELATIVELY QUIET PERIOD WL BE TEMPS
IN WAD PATTERN THAT WL DOMINATE.
TNGT...STRONG WARM/DRY ADVECTION WITH WSW H925-85 FLOW WL DISSIPATE
LINGERING LO/MID CLD SW-NE AS MODELS SHOW STEADILY RISING H85 TEMPS
AND LOWERING RH...INDICATING THE WAD IS BEING MANIFEST AS HORIZONTAL
ADVECTION/EROSION OF COLD AIR AND NOT UPWARD MOTION OVER THE COLD
DOME. IN FACT...NAM/GFS SHOW H85 TEMPS REACHING 7C AT IWD BY 12Z.
ANY PCPN WL BE OVER THE NE HALF OF LK SUP MAINLY THIS EVNG... AND
THIS WL DIMINISH WITH TIME. ALTHOUGH THE DEEPER COLD AIR WL BE
RETREATING...SUSPECT POCKETS OF NEAR SFC COLD AIR WL BE MORE
RESILIENT OVER THE INTERIOR. SO TENDED TOWARD THE LO END OF GUIDANCE
IN THESE AREAS. THE WARMEST LOCATIONS ARE LIKELY TO BE IN THE
DOWNSLOPE AREAS NEAR LK SUP.
SUN...THE CWA WL BE DOMINATED BY THE WARM...DRY WSW FLOW BTWN HI
PRES SINKING INTO THE OH VALLEY AND LO PRES CROSSING NW ONTARIO.
LOOKING UPSTREAM...SKIES ARE MOSUNNY AS THE DRY AIRMASS SHOWN ON THE
12Z BISMARCK RAOB IS DOMINATING. WITH H85 TEMPS FCST TO BE ABOUT
7C...EXPECT TEMPS TO RECOVER WELL ABV NORMAL. HOWEVER...EXACTLY HOW
HI TEMPS CAN RISE WL BE TRICKY WITH RESIDUAL ARCTIC AIR LIKELY TO BE
LINGERING NEAR THE SFC. CONSIDERING THE HI STABILITY SHOWN ON FCST
SDNGS AS WELL AS LO SUN ANGLE...TENDED TOWARD THE LOWER END OF
GUIDANCE. ONCE AGAIN...EXPECT THE HIEST TEMPS ARND 40 IN THE
DOWNSLOPE AREAS NEAR LK SUP WHERE ANY LINGERING NEAR SFC COLD AIR IS
MOST LIKELY TO BE ERODED.
.LONG TERM /00Z MONDAY THROUGH NEXT SATURDAY/...
A WEAK SFC TROUGH WILL EXTEND FROM THE CENTRAL PLAINS STATES THROUGH
PART OF THE CWA FROM LATE SUNDAY THROUGH TUESDAY. MODELS ARE IN
PRETTY GOOD AGREEMENT WITH THIS AND BRINGING AN UPPER SHORTWAVE OVER
THE CWA MONDAY. THE SHORTWAVE COMBINED WITH ISENTROPIC ASCENT WILL
BRING PERIODS OF PRECIP TO THE CWA EARLY MONDAY THROUGH
TUESDAY...WITH THE PRECIP TYPE BEING COMPLEX. THERMAL AND MOISTURE
PROFILES WILL BE THE COMPLICATING FACTOR...AND WILL LEAD TO CHANCES
FOR FREEZING DRIZZLE BEFORE SFC TEMPS WARM UP ON MONDAY...BECOMING
CHANCES FOR A RAIN AND SNOW MIX THROUGH TUESDAY THAT WILL BE MORE
DOMINATED BY SNOW OVER TIME AS COLDER AIR MOVES IN FROM N TO S. MID
LEVEL MOISTURE WILL BE SOMEWHAT LACKING...ESPECIALLY OVER THE SRN
CWA...WHICH FURTHER LOWERS CONFIDENCE ON PTYPE SINCE MOISTURE WILL
BE MINIMAL IN...ABOVE...AND BELOW THE DGZ.
OVERALL CONFIDENCE DECREASES STARTING WEDNESDAY AS MODELS WAIVER
WITH THE HANDLING OF THE NEXT SYSTEM. THE GEM AND ECMWF HAVE BETTER
RUN TO RUN CONTINUITY THAT THE GFS DURING THIS TIME PERIOD...BUT ARE
STILL NOT THAT GREAT. USED A MODEL BLEND FROM WEDNESDAY OUT AS
CONFIDENCE IN ANY MODEL OR SET OF MODELS IS JUST TOO LOW.
LARGE SCALE PATTERN WISE...MODELS SEEM TO HAVE THE SAME GENERAL
IDEA. A 500MB LOW WILL MOVE FROM THE ACTIC CIRCLE FROM WEDNESDAY TO
HUDSON BAY THURSDAY AS A SERIES OF UPPER LEVEL DISTURBANCES MOVE
INTO THE NWRN CONUS FROM THE NRN PACIFIC. THIS WILL KICK A DEEP
500MB LOW ALREADY IN PLACE OVER SRN CA INTO THE PLAINS WEDNESDAY
NIGHT. THE UPPER LOW WILL WEAKEN TO A WEAK TROUGH AND MOVE UP THE E
SIDE OF A NEW DEEP TROUGH OVER THE W CENTRAL CONUS...WITH THE
SHORTWAVE MOVING OVER THE CWA DURING THE LATTER HALF OF THURSDAY.
MODELS IN THE PAST WERE SHOWING THE UPPER SYSTEM MOVING OVER AS A
DEEPER CLOSED LOW...BUT HAVE BEEN TRENDING WEAKER AND IN MORE OF AN
OPEN WAVE ALOFT.
THIS WHOLE PATTERN WOULD RESULT IN MIXED PRECIP MOVING INTO THE CWA
ON WEDNESDAY AS A WEAK SHORTWAVE MOVE OVER WITH ISENTROPIC ASCENT
ALSO HELPING OUT. THEN AS THE UPPER TROUGH TROUGH MOVES THROUGH
THURSDAY...A CLOSED SFC LOW WILL DEVELOP AND MOVE OVER OR NEAR THE
CWA. THE ECMWF AND GEM BRING THE SFC LOW RIGHT ALONG THE SERN EDGE
OF THE CWA...WHILE THE GFS MOVES IT OVER FARTHER SE OVER CENTRAL
LOWER MI. GIVEN A MODEL BLEND...THE BEST CHANCES FOR PRECIP WILL BE
OVER THE SERN CWA...WHICH IS ALSO WHERE THE CONFIDENCE IN THE
FORECAST WITH THIS SYSTEM IS HIGHEST. PTYPE IS MORE IN
QUESTION...BUT WOULD LEAN TOWARD A RAIN/SNOW MIX OVER THE SERN CWA
AND MORE SNOW OVER THE NWRN CWA. THERE IS POTENTIAL FOR SIGNIFICANT
SNOWFALL ACCUMULATIONS SOMEWHERE IN THE REGION...BUT THAT IS HIGHLY
DEPENDENT ON THE TRACK OF THE SYSTEM. IF THE SYSTEM MOVES SOMEWHERE
BETWEEN THE TRACKS SHOWN BY THE GFS AND ECMWF...IT WOULD BE A
TYPICAL TRACK FOR HEAVY SNOW ACROSS PORTIONS OF THE CWA...BUT
CONFIDENCE IS WA TOO LOW TO PINPOINT THAT AT THIS TIME.
THE SFC LOW EXITS EAST AND HIGH PRESSURE MOVES IN FROM THE W FRIDAY
AND SATURDAY...AS 850MB TEMPS FALL TO AOB -15C. WITH W-NW
WINDS...LES WOULD APPEAR A LIKELY RESULT...BUT MOISTURE...WIND
DIRECTIONS AND OTHER FINICKY ENGREDIENTS WILL HAVE TO BE SORTED AS
TIME GOES ON.
&&
.AVIATION /FOR THE 18Z TAF ISSUANCE/...
ALTHOUGH THERE WL BE PLENTY OF MID CLD ARND THIS AFTN INTO THE EARLY
EVNG...EXPECT VFR CONDITIONS AT ALL 3 SITES THIS FCST PERIOD WITH
DRY LLVL SW FLOW DOMINATING. THERE WL BE SOME LLWS AT MAINLY IWD/SAW
TNGT WHERE THE WINDS WL BE STRONGEST AT THE TOP OF STABLE COLD AIR
NEAR THE SFC. DAYTIME HEATING/MIXING ON SUN WL DIMINISH THIS THREAT
BY NOON.
&&
.MARINE /FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE/...
EXPECT INCREASING WSW WINDS TO 30 KTS LATE TONIGHT AND SUN UNDER
SHARPENING PRES GRADIENT BETWEEN HI PRES IN THE OH RIVER VALLEY AND
LO PRES CROSSING ONTARIO. BEST CHANCE FOR MARGINAL GALES TO 35 KTS
WILL BE ON SUN IN THE SWATH OVER THE W BETWEEN ISLE ROYALE AND THE
KEWEENAW...WHERE TERRAIN FUNNELING CAN ENHANCE WSW WIND SPEEDS. BUT
GIVEN HI STABILITY...OPTED TO MAINTAIN JUST MENTION OF GALE FORCE
GUSTS ATTM. WITH A LO PRES TROF/WEAKER GRADIENT SINKING ACROSS LK
SUP ON MON/MON NIGHT...LOOK FOR WINDS TO DIMINISH AND SHIFT TO THE
N. LIGHT WINDS SHIFTING TO THE S WILL THEN BE THE RULE INTO WED AS A
HI PRES RIDGE SLIDES OVER THE LK AND TO THE E. ANOTHER LO PRES WILL
MOVE NE TOWARD THE UPPER LKS ON THU...BUT GALES DO NOT APPEAR LIKELY
ATTM.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...KC
SHORT TERM...KC
LONG TERM...TITUS
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1214 AM EST SAT DEC 10 2011
UPDATED AVIATION DISCUSSION FOR 06Z TAFS
.UPDATE...
LAKE EFFECT SNOW CONTINUES TO FALL OVER LOCATIONS FAVORED BY A WEST
WIND THIS EVENING. RUC ANALYSIS HAS H850 TEMPS AROUND -15C E AND
-17C WEST...PUTTING MUCH OF THE LLVL OMEGA IN THE DGZ. WITH A SFC
RIDGE OVER MN...DRIER AIR HAS BEEN FILTERING OVER WRN LK SUPERIOR
AND HAS LIKELY BEEN KEEPING LES IN CHECK WITH INVERSION HEIGHTS AOB
5KFT...ALTHOUGH LATEST RADAR SHOWING SOME RETURNS NEAR TWIN LAKES OF
5.5KFT. DECIDED TO LET HEADLINES EXPIRE OVER THE WEST SINCE CALLS
INDICATED ONLY AN INCH OR TWO HAD FALLEN OVER 3-4HRS PRIOR TO THE
ENDING TIME. DID TOY WITH THE IDEA OF EXTENDING THE LES WARNING FOR
NRN HOUGHTON SINCE THERE WILL LIKELY STILL BE A PERIOD OF MODERATE
SNOW OVER THE NEXT FEW HOURS. THIS COULD DROP ANOTHER 1 TO 4 INCHES
FROM TWIN LAKES TOIVOLA BEFORE WINDS TURN TO THE SW OVERNIGHT AND
PUSH THE MAIN BAND N.
OVER THE EAST...HAD SOME INITIAL CONCERN ON THE ADVY DUE TO THE
PERSISTENT SW WINDS OVER NCNTRL UPPER MI AND SCNTRL LK SUPERIOR.
HIGH RES MODELS STILL SHOWING WEAK SFC TROUGH SHIFTING WINDS MORE
OUT OF THE WNW OVER THE NEXT COUPLE OF HOURS WITH THE SFC TROUGH
DROPPING THROUGH...WHICH IS ALREADY SEEN AT ISLE ROYALE AND LATEST
OBS AT KCMX/STDM4 ARE STARTING TO SHOW. THIS HAS FINALLY STARTED TO
PUSH THE LES BAND FARTHER S AND NEAR NE LUCE COUNTY. WITH LONGER
FETCH...LLVL CONVERGENCE AND INVERSION HEIGHTS NEAR 10KFT...EXPECT
MODERATE TO HEAVY SNOW TO OCCUR ONCE THE BAND MOVES ON SHORE. KMQT
RADAR ESTIMATES THIS EVENING IN THE MAIN BAND HAVE HAD 1-2 INCH PER
HOUR SNOWFALL RATES. FEEL FAIRLY CONFIDENT ON ADVISORY FOR LUCE
COUNTY WITH LATEST TRENDS...BUT ALGER MAY BE A LITTLE IFFY...SINCE
DOWNSLOPE SW WINDS OVER MARQUETTE COUNTY ARE HELPING INJECT DRIER
AIR INTO THE SRN EDGE. WILL LEAVE ADVISORY AS IS AND ONLY MADE SOME
MINOR TWEAKS TO THE GOING SNOWFALL FORECAST...MAINLY TO FOCUS MORE
OVER LUCE COUNTY. EXPECT THE LES TO DIMINISH AND PUSH OFF SHORE LATE
TONIGHT INTO TOMORROW MORNING.
&&
.SHORT TERM /THROUGH 00Z SUNDAY/...
WITH A DEEP UPPER TROUGH OVER THE REGION THIS AFTERNOON...THE
COOLEST AIR OF THE SEASON IS CHILLING OUT OVER THE CWA. LOWS LAST
NIGHT FELL INTO THE SINGLE DIGITS AND TEENS OVER LAND AREAS...AND
LIKELY BELOW ZERO IN TYPICAL COLD SPOTS OVER THE INTERIOR WEST.
HIGHS TODAY SHOULD BE IN THE TEENS TO LOW 20S. WEST WIND LES THAT
HAS BEEN HITTING THE WRN AND OCCASIONALLY FAR NERN CWA IS CHANGING
ORIENTATION TODAY AS A RIDGE OF HIGH PRESSURE SLOWLY MOVES TOWARD
THE CWA FROM THE W. THIS IS CAUSING WINDS TO BE MORE FROM THE
WNW...WHICH IS ACTING TO BRING LES BANDS INTO THE FAR NERN CWA EAST
OF MUNISING.
THE SFC RIDGE AXIS WILL MOVE TO WRN LAKE SUPERIOR BY 06Z SAT...AND
TO CENTRAL LAKE SUPERIOR BY 18Z SAT. THIS WILL PUSH MOST LES
OFFSHORE FROM A SW WIND SATURDAY MORNING...EXCEPT OVER THE KEWEENAW
WHICH MAY SEE SOME LINGERING PATCHY LES THROUGH SAT.
THE TRICKIEST PART OF THE SHORT TERM IS WITH LES EAST OF MUNISING.
FINE SCALE MODELS SHOW THE STRONG LES BAND...CURRENTLY MAKING
LANDFALL OVER THE NERN CWA...LINGERING LONG ENOUGH TO PRODUCE
ADVISORY SNOWFALL AMOUNTS OF 5 TO 8 INCHES IN 12 HOURS NEAR LAKE
SUPERIOR. HAD HIGH ENOUGH CONFIDENCE TO ISSUE LES ADVISORY FOR ALGER
AND LUCE COUNTIES GIVEN RADAR AND SAT TRENDS SHOWING THE BAND
MOVING S FROM WNW WINDS...BUT UNCERTAINTY REMAINS AS TO HOW LONG THE
BAND WILL SIT OVER ANY ONE AREA BEFORE IT MOVES OUT SAT MORNING.
TONIGHT LOOKS TO BE PRETTY COLD AS THE HIGH MOVES IN BRINGING CLEAR
SKIES AWAY FROM LAKE SUPERIOR. MAJORITY OF GUIDANCE SHOWS TEMPS
FALLING BELOW ZERO TONIGHT INLAND. UPSTREAM TEMPS OVER MN FELL TO
THE MID SINGLE DIGITS BELOW ZERO LAST NIGHT...WHICH SEEMS QUITE
REASONABLE FOR INLAND AREAS OF UPPER MICHIGAN TONIGHT.
.LONG TERM DISCUSSION /SAT NGT THRU FRI/...
SAT NGT/SUN...CWA WL BE DOMINATED BY STRONG WSW FLOW BTWN HI PRES IN
THE OH RIVER VALLEY/MID ATLANTIC STATES AND LO PRES CROSSING SCNTRL
CAN/NW ONTARIO TOWARD JAMES BAY BY LATE SUN. EXPECT AN AREA OF WAD
CLD ASSOCIATED WITH H85 WINDS INCRSG TO NEAR 50KTS/SHARP ISENTROPIC
ASCENT ON THE 280-290K SFCS /H85-7/ OVER THE E ON SAT EVNG TO SHIFT
AWAY THE AREA AS THE WAD CONTRIBUTES TO HORIZONTAL WARMING INSTEAD
OF UPWARD MOTION. IN FACT...H85 TEMPS ARE FCST TO RISE FM -3C/-10C
AT IWD/ERY AT 00Z SUN TO 6C/0C AT 12Z SUN. H85 TEMPS ARE FCST TO
LINGER ARND 5C THE WHOLE DAY ON SUN. SINCE THE INCOMING WARMER
AIRMASS WL ALSO BE QUITE DRY...SKIES SHOULD TREND MOCLR AFT THE WAD
CLD EXITS TO THE E. HOW MUCH OF THE H85 WARMING GETS MIXED TO THE
SFC IS CRITICAL IN DETERMINING HOW TEMPS RISE AT THE SFC ON SUN.
WITH HI STABILITY SHOWN ON FCST SDNGS AND LO SUN ANGLE...TENDED
TOWARD THE LOWER END OF GUIDANCE FOR TEMPS ON SAT NGT AND SUN. EVEN
SO...MOST PLACES WL LIKELY SEE THE MERCURY CLIMB WELL INTO THE
30S...WARMEST IN THE DOWNSLOPE AREA NEAR LK SUP. BUT THE STIFF WSW
WIND WL MAKE THE AIR FEEL COLDER.
SUN NGT...WITH APRCH OF LO PRES TROF/COLD FNT ATTENDANT TO SFC LO
MOVING INTO QUEBEC...THE STRONGER SW WINDS WL DIMINISH ON SUN NGT.
BUT MODELS BEGIN TO SHOW LLVL MSTR RETURNING AHEAD OF THIS TROF...
SO EXPECT LO CLDS TO ARRIVE. SINCE THE MID LVLS ARE FCST TO REMAIN
DRY WITH AN ABSENCE OF MID LVL FORCING UNDER A BIT OF AN H5 RDG
AXIS...ANY PCPN WOULD LIKELY BE IN THE FORM OF FZDZ AS FCST SDNGS
SHOW MSTR WELL BLO THE DGZ.
MON/MON NGT...WITH THE APRCH OF LO PRES TROF AND A SHRTWV FM THE W
AS WELL AS INCRSG AND DEEPER MSTR RETURN...EXPECT AN INCRSG CHC OF
PCPN ON MON. PCPN INTENSITY WL BE LIMITED BY RELATIVELY SHALLOW
NATURE OF DEEPER MSTR THAT REMAINS FOR THE MOST PART BLO A HIER DGZ
CENTERED ARND 12K FT. A FAIRLY WARM BLYR MAY SUPPORT AT LEAST A MIX
WITH RA OVER PORTIONS OF THE E HALF ON MON PER SOMEWHAT WARMER
NAM...BUT ANY PCPN WL TURN TO SN ON MON NGT WITH THE ARRIVAL OF
SOMEWHAT COLDER AIR IN THE CYC NLY FLOW LEFT IN THE WAKE OF THE
SLOWLY DEPARTING DISTURBANCE. AS THE SHRTWV/DEEPER MSTR EXIT TO THE
E ON MON NGT...PCPN CHCS WL DIMINISH W-E BUT NOT END COMPLETELY WITH
LINGERING CYC FLOW. H85 TEMPS FALLING INTO THE -6C TO -8C WL BE
MARGINAL FOR LES...BUT CYC FLOW MAY ACT AS A WEAK ENHANCEMENT
MECHANISM.
EXTENDED FCST...THIS PERIOD WL BE DOMINATED BY A BLDG RDG OVER THE
SE CONUS...WHICH WL FORCE A HEALTHY NEGATIVELY TILTED SHRTWV/SFC LO
TO RIDE NEWD FM THE PLAINS INTO THE GRT LKS ON WED-THU. PER NCEP
DISCUSSION...FAVORED THE FARTHER W TRACK FOR THIS LO AS SHOWN BY 12Z
GFS/ECMWF. THIS TRACK WOULD SUPPORT A WINTRY MIX OF PCPN FOLLOWED BY
SOME LES ON FRI AS COLDER AIR RETURNS IN THE WAKE OF THE DEPARTING.
OVERALL...TEMPS WL AVG WELL ABV NORMAL FOR THE SEASON DURING THIS
TIME.
&&
.AVIATION /FOR THE 06Z TAF ISSUANCE/...
ONGOING WESTERLY LAKE EFFECT SNOW WILL CONTINUE TO AFFECT KCMX
THROUGH THE NIGHT...BEFORE ENDING TOMORROW MORNING AS WINDS SHIFT TO
THE SW AND PUSH THE SNOW BANDS NORTH OF THE SITE. EXPECT MAINLY MVFR
CONDITIONS THROUGH THE NIGHT...BUT COULD REACH IFR VSBY LATE TONIGHT
AS THE DOMINATE BAND OVER CENTRAL HOUGHTON COUNTY SHIFTS N ACROSS
THE KEWEENAW PENINSULA. OTHERWISE...EXPECT VFR CONDITIONS AT THE
OTHER TWO SITES...DUE TO UNFAVORABLE LES WIND DIRECTIONS. A WEAK LOW
PRESSURE SYSTEM MOVING INTO THE NRN PLAINS WILL BRING INCREASING
CLOUDS TO ALL SITES ON SAT...BUT EXPECT CIGS TO BE VFR.
&&
.MARINE /FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE/...
WITH STRONG WINDS AND COLD TEMPERATURES...FREEZING SPRAY WILL REMAIN
POSSIBLE INTO SATURDAY MORNING. A HIGH PRESSURE SYSTEM WILL DIVE SE
FROM THE PLAINS STATES TO THE MID MISSISSIPPI VALLEY BY
SATURDAY...BEFORE EXITING TO THE CENTRAL APPALACHIANS AND MID
ATLANTIC SUNDAY. THE RESULT ACROSS LS WILL BE A RIDGE THROUGH
SATURDAY. EVEN WITH A RIDGE OF HIGH PRESSURE OVERHEAD...THE PRESSURE
GRADIENT BETWEEN THE LOW TO OUR NORTH AND HIGH PRESSURE ROUNDING THE
AREA TO THE SOUTH WILL KEEP STRONG WINDS OF 20 TO 30KTS IN THE
FORECAST THROUGH SUNDAY NIGHT. SW GALE FORCE GUSTS TO 35KTS WILL BE
POSSIBLE SATURDAY MAINLY OVER WESTERN LAKE SUPERIOR AS THE HIGH
EXITS TO OUR SE AND LOW PRESSURE NEARS FROM CANADA. THIS LOW OVER
SOUTH CENTRAL CANADA SATURDAY NIGHT WILL SLIDE ACROSS EASTERN
ONTARIO SUNDAY NIGHT...WITH A TROUGH EXTENDING SOUTHWESTWARD FROM
THE LOW. EXPECT THE TROUGH TO STALL OUT ACROSS THE UPPER GREAT LAKES
MONDAY THROUGH TUESDAY MORNING...BEFORE A RIDGE BUILDS BACK IN FROM
THE WEST LATE IN THE DAY TUESDAY. A LOW PRESSURE SYSTEM WILL BEGIN
TO MOVE TOWARD THE AREA FROM THE CENTRAL PLAINS STATES...BUT THERE
REMAINS UNCERTAINTY AS TO THE EXACT TRACK AND STRENGTH OF THE SYSTEM.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 9 AM EST THIS MORNING FOR MIZ006-
007.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...SRF
SHORT TERM...TITUS
LONG TERM...KC
AVIATION...SRF
MARINE...TITUS
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
330 PM CST Sat Dec 10 2011
.DISCUSSION...
Brisk southwest winds coupled with abundant sunshine have allowed
afternoon temperatures to climb into the mid to upper 30s across
northeast Missouri to the middle 40s across eastern Kansas and
western Missouri. While gusty conditions are expected to subside this
evening, moderate southwesterly sfc flow is expected to persist
overnight as a sfc low slides across the northern tier of the country
while sfc ridging moves into the Ohio valley. Stubborn stratus has
been slow to erode across southwestern Kansas this afternoon with
models doing a poor job resolving the feature. Uncertainty remains
high as to whether additional stratus will develop overnight and
advect northeastward. There appears to be some support of this idea
from the latest RUC and VSREF outputs after 03-04z. Will hold off on
stratus mention at the moment although may have to be added by later
shifts should stratus development show signs of coming to fruition.
Southerly low level flow will be maintained tomorrow as the
aforementioned sfc low skirts across southern Canada. This coupled
with increasing thicknesses should yield temperatures climbing a few
degrees higher than seen today. By Sunday night, 35-40kt LLJ may
support a few showers across far northwest Missouri as isentropic
ascent increases across this area.
Vigorous upper level trough will begin translating across the
southwestern US during the beginning of the week spreading height
falls across the plains. This will maintain WAA regime Monday and
Tuesday keeping afternoon temperatures in the 40s to near 50
degrees. The amount of warming will likely be offset to some extent by
increasing cloud cover during this time frame. Guidance has come into
better agreement on a lead wave ejecting across the plains during the
day Tuesday bringing the first round of rain the region. Have
increase POPs to the high chance category during the day Tuesday with
likely wording for Tuesday night across portions of central Missouri.
The main upper system then moves into the plains and Midwest on
Wednesday keeping high rain chances in place through Wednesday night. In
addition, sufficient moisture and ascent should be in place for at
least an isolated chance of thunderstorms as well. This system slides
east of the area by Thursday with the next upper trough diving into
the desert southwest by Friday. Uncertainty increases thereafter and
have went with a dry forecast through the remainder of the forecast
to account.
DEROCHE
&&
.AVIATION...
VFR conditions expected through this evening across all three taf
sites with clear skies and moderate southerly winds. Models continue
to suggest stratus/fog development across portions of central Kansas
by tomorrow morning. Condensation pressure deficits suggest this
activity to remain west of the terminals so will exclude from
mentioning in the taf. However, if this trends further east then a
mention may be needed in later taf issuances.
DEROCHE
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
WFO EAX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1139 PM CST FRI DEC 9 2011
.UPDATE...
/812 PM CST FRI DEC 9 2011/
AREA OF CLOUDS ARE MOVING SOUTHEAST INTO CENTRAL MO...SO HAVE
INCREASED CLOUD COVER OVER CENTRAL MISSOURI THIS EVENING. LAST
SEVERAL RUNS OF THE RUC HAVE BEEN CONSISTENT THAT 900-850MB
RELATIVE HUMIDITY WILL REMAIN HIGH ALONG I-70 TOWARD THE ST. LOUIS
METRO AREA INTO EARLY SATURDAY MORNING. SO HAVE GONE WITH MOSTLY
CLOUDY SKIES OVER THE SOUTHWESTERN PART OF THE CWA THROUGH 12Z.
HAVE KEPT LOW TEMPS THE SAME FOR NOW AS TEMPERATURES HAVE FALLEN
QUICKLY UNDER CLEAR SKIES THIS EVENING AND WEAK LOW LEVEL COLD AIR
ADVECTION SHOULD CONTINUE THROUGH MIDNIGHT.
BRITT
&&
.DISCUSSION...
/259 PM CST FRI DEC 9 2011/
NOT A LOT GOING ON IN THE SHORT TERM...JUST DEALING WITH
TEMPS...BEYOND THAT MODELS CONTINUE TO BRING IN A DECENT SYSTEM BY
MIDWEEK NEXT WEEK.
FOR TONIGHT...AS RIDGE OF HIGH PRESSURE SETTLES INTO THE AREA...WILL
SEE CLOUDS CLEAR OUT AND WINDS REMAINING LIGHT AND FROM THE NORTH.
IT WILL BE THE COLDEST NIGHT SO FAR WITH LOWS NEAR 10 DEGREES FAR
NORTH TO THE UPPER TEENS FAR SOUTH AND EAST.
ON SATURDAY...RIDGE OF HIGH PRESSURE TO SLOWLY MOVE OFF TO THE EAST
ALLOWING SOUTHERLY WINDS TO RETURN. CAN EXPECT A WARMUP OVER THE
WEEKEND AND INTO EARLY NEXT WEEK. HIGHS ON SATURDAY WILL REMAIN
RATHER CHILLY...IN THE 30S...THEN TEMPS TO WARM UP INTO THE 40S ON
SUNDAY AND MONDAY. ONE FLY IN OINTMENT WILL BE A WEAK FRONTAL
BOUNDARY THAT WILL APPROACH AREA MONDAY NIGHT AND TUESDAY. WILL
MAINLY JUST SEE AN INCREASE IN CLOUD COVER WITH SYSTEM AS IT STALLS
OUT OVER FORECAST AREA. DEPENDING ON WHERE THE FRONT STALLS
OUT...TEMPS COULD VARY QUITE A BIT ON TUESDAY. FOR NOW HAVE HIGHS IN
THE LOW TO MID 40S.
TUESDAY NIGHT MODELS HAVE FRONTAL BOUNDARY MOVING BACK NORTH AS WARM
FRONT...SO WILL SEE COLDEST TEMPS EARLY ON...THEN TEMPS TO REMAIN
STEADY OR SLOWLY RISE OVERNIGHT. LOW LEVEL MOISTURE WILL BE ON THE
INCREASE AS WELL...SO WILL SEE SOME SHOWERS DEVELOPING...MAINLY OVER
CENTRAL AND SOUTHERN MO.
BEYOND THAT...STRENGTHENING WEATHER SYSTEM OVER THE TEXAS
PANHANDLE...SLIDING NORTHEAST ALONG FRONTAL BOUNDARY INTO THE
FORECAST AREA BY WEDNESDAY NIGHT. SHOULD SEE DECENT CHANCES OF PCPN
IN THE FORECAST AREA WEDNESDAY THROUGH THURSDAY. SOME LOW TO
MODERATE INSTABILITY WITH THIS SYSTEM...SO COULD SEE SOME
THUNDERSTORMS WEDNESDAY AFTERNOON AND NIGHT. AS FOR TEMPS...RATHER
MILD MIDWEEK WITH HIGHS IN THE MID 40S TO LOW 50S WEDNESDAY AND IN
THE UPPER 40S TO MID 50S ON THURSDAY. AS SYSTEM EXITS LATE ON
THURSDAY...COLDER AIR TO SLOWLY FILTER IN WITH HIGHS IN THE UPPER
30S TO UPPER 40S ON FRIDAY.
BYRD
&&
.AVIATION...
/1132 PM CST FRI DEC 9 2011/
VFR FLIGHT CONDITIONS AND LIGHT AND VARIABLE WINDS WILL PREVAIL
ACROSS THE BI-STATE AREA FOR THE REST OF THE NIGHT. A 4000-5000FT
DECK WILL CONTINUE TO MOVE ACROSS CENTRAL MISSOURI...AND CIGS MAY
FALL TO NEAR MVFR VALUES TOWARD SUNRISE...BUT CLOUDS MUCH BELOW
3000FT DO NOT APPEAR LIKELY. WIND WILL BECOME SOUTHWESTERLY ON
SATURDAY AS HIGH PRESSURE MOVES EAST OF THE AREA...AND VFR FLIGHT
CONDITIONS WILL CONTINUE TO PREVAIL.
SPECIFICS FOR KSTL...
VFR FLIGHT CONDITIONS AND LIGHT/VARIABLE WINDS WILL PREVAIL AT
LAMBERT FOR THE REMAINDER OF THE NIGHT. WILL LIKELY SEE
INTERMITTENT FEW CLOUDS AROUND 5000FT DRIFT BY THE TERMINAL...BUT
CIGS OVER CENTRAL MISSOURI SHOULD NOT AFFECT LAMBERT. WIND WILL
BECOME SOUTHWESTERLY LATE SATURDAY MORNING AS HIGH PRESSURE DRIFTS
EAST OF THE TERMINAL. VFR CONDITIONS WILL CONTINUE TO PREVAIL.
CARNEY
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1218 PM EST SAT DEC 10 2011
.SYNOPSIS...
COLD AND DRY CONDITIONS WILL DEVELOP TODAY AND PERSIST THROUGH
TUESDAY AS ARCTIC HIGH PRESSURE MOVES TO OUR NORTH. WARMING
TEMPERATURE ARE EXPECTED WEDNESDAY THROUGH FRIDAY AS HIGH PRESSURE
MOVES OFFSHORE.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1230 PM SATURDAY...LOW CLOUDS CONTINUE TO ERODE FROM WEST TO
EAST PRETTY MUCH ON SCHEDULE. TEMPERATURES ARE RISING INTO THE 52-54
RANGE WHICH MAKES OUR PREVIOUS HIGHS LOOK REASONABLE. WE DID
INCREASE WIND SPEEDS BY A COUPLE MPH...ESPECIALLY IN THE ILM
VICINITY...BASED ON LATEST OBSERVATIONS. PREVIOUS DISCUSSION FROM
930 AM FOLLOWS...
THE NORTHERN AND SOUTHERN BRANCHES OF THE JET STREAM ARE COMBINING
FORCES ACROSS THE EASTERN U.S. THIS MORNING AS A STRONG UPPER TROUGH
MOVES EAST ACROSS THE GREAT LAKES. A WEAKER SOUTHERN STREAM VORT
MOVING JUST AHEAD OF THE STRONG NORTHERN STREAM FEATURE IS CROSSING
THE CAROLINAS CURRENTLY...HELPING TO INDUCE A FEW LIGHT SPRINKLES
ACROSS THE EASTERN CAROLINAS. THESE SPRINKLES SHOULD LARGELY
DISSIPATE AND/OR MOVE OFF THE COAST WITHIN THE NEXT HOUR AS THE
TROUGH EXITS TO THE EAST.
PLENTY OF LOW CLOUDS WILL LINGER THROUGH THE AFTERNOON ALONG THE
COAST...BUT INLAND AREAS SHOULD CLEAR OUT AS THE WESTERLY FLOW ABOVE
850 MB BRINGS DRIER AIR IN. JET STREAM CIRRUS WILL LINGER THROUGH
THE DAY AS WELL...BUT MODELS SHOW EVEN THAT MOISTURE PLUME EXITING
THE COAST (TEMPORARILY) THIS EVENING.
THE LARGEST FORECAST CONCERN TODAY IS HIGH TEMPERATURES. INCREASING
COLD ADVECTION WILL COUNTER MOST OF THE SUNSHINE THAT CAN SNEAK
THROUGH THE CLOUDS TODAY...CREATING ONLY A SLOWLY RISING TEMPERATURE
CURVE FOR MOST AREAS. HIGHS WILL PROBABLY ONLY REACH THE MID TO
UPPER 50S TODAY...NOT EVEN A 10 DEGREE RISE FROM CURRENT READINGS.
THE LATEST HRRR DID NOT INITIALIZE TOO PARTICULARLY WELL WITH
TEMPERATURES SO WE HAVE MADE NO SIGNIFICANT CHANGES TO THE HIGH TEMP
FORECAST NOW...BUT WILL MONITOR HOURLY TEMPERATURES CLOSELY FOR
LATER UPDATES.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 AM FRIDAY...HIGH PRESSURE WILL EXTEND INTO THE AREA
THROUGH THE PERIOD WHILE AN OLD FRONTAL BOUNDARY LINGERS OFF THE
COAST. THE FRONT WILL BE CLOSE ENOUGH SUNDAY NIGHT INTO MONDAY TO
YIELD AN INCREASE IN CLOUDS. THERE IS ALSO AN OUTSIDE SHOT FOR
LIGHT RAIN BUT THE PROBABILITY IS LOW ENOUGH PRESENTLY THAT NO
MENTION OF RAIN WILL BE MADE IN THE FORECAST. DECREASING CLOUDS ARE
ON TAP FOR MONDAY AFTERNOON AND NIGHT. BELOW NORMAL TEMPERATURES
EXPECTED BOTH DAYS WITH HIGHS IN THE LOW TO MID 50S SUNDAY AND MID
TO UPPER 50S MONDAY. LOWS EACH NIGHT WILL BE IN THE 30S.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 3 AM FRIDAY...IN GENERAL...HIGH PRESSURE WILL CONTROL AREA
WEATHER THROUGH THE PERIOD. THE RESULT WILL BE FAIR WEATHER AND A
WARMING TREND. ONE POTENTIAL FLY IN THE OINTMENT WILL TAKE THE FORM
OF A COLD FRONT APPROACHING FROM THE NORTH ALONG ABOUT THURSDAY
AFTERNOON. LATEST GUIDANCE KEEPS THIS FRONT WELL TO OUR NORTH BUT
IT IS POSSIBLE THAT IT COULD GET CLOSE ENOUGH TO INCREASE CLOUD
COVER AND BRING A CHANCE OF SHOWERS THURSDAY NIGHT.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 18Z...HIGH CONFIDENCE IN VFR THROUGH THE VALID PERIOD.
MID LEVEL TROUGH AS EVIDENCED BY SIGNIFICANT WIND SHIFT AT 850 MB
WILL CONTINUE TO ROTATE EAST ACROSS THE AREA THROUGH THIS EVE. MUCH
DRIER AIR WORKS IN BEHIND THIS TROUGH...SO BY TONIGHT ALL TERMINALS
WILL EXPERIENCE SKC. NORTH WINDS OF 9-12 KTS WILL DECREASE AFTER
SUNSET...BUT TIGHTENED PG AHEAD OF ADVANCING HIGH PRESSURE WILL KEEP
THEM FROM DECOUPLING. THIS SUGGESTS WINDS REMAINING 4-8 KTS
OVERNIGHT.
AFTER SUNRISE E/NE WINDS WILL INCREASE...GUSTING UP TO 20 KTS BY
LATE MORNING. THIS WILL ADVECT MOISTURE INTO THE COLUMN...WHICH MAY
DEVELOP INTO A 5-6 KFT CLOUD LAYER IF FORECAST SOUNDINGS ARE
CORRECT. HOWEVER...SIGNIFICANT DRY AIR JUST ABOVE THE INVERSION WILL
LIKELY MIX OUT MUCH OF THE MOISTURE SO HAVE ONLY SCT AT THE COAST
WITH SKC CONTINUING INLAND THROUGH 18Z SUNDAY.
EXTENDED OUTLOOK...LOW CONFIDENCE IN SHOWERS AND STRATUS SUNDAY
NIGHT INTO MONDAY MORNING...ESPECIALLY NEAR THE COAST. VFR MONDAY
THROUGH WEDNESDAY. LOW CONFIDENCE IN FOG THURSDAY MORNING.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM SATURDAY...WINDS AND SEAS CONTINUE TO SLOWLY INCREASE
AS COLD AIR POURS OFFSHORE AND THE PRESSURE GRADIENT TIGHTENS WITH
THE APPROACH OF THE ARCTIC HIGH. ALL FORECAST ELEMENTS LOOK TO BE ON
TRACK AND NO CHANGES WERE NECESSARY TO THE FORECAST. PREVIOUS
DISCUSSION FROM 930 AM FOLLOWS...
COLD AIR IS BUILDING INTO THE AREA THIS MORNING AS ARCTIC HIGH
PRESSURE OVER MISSOURI/SOUTHERN ILLINOIS BUILDS EAST. THE PRESSURE
GRADIENT WILL REALLY INCREASE TONIGHT AS THE HIGH MOVES INTO THE
OHIO VALLEY...CAUSING OUR WIND SPEEDS TO INCREASE TO A SOLID 25 KT
AWAY FROM SHORE WITH HIGHER GUSTS. UNTIL THEN...NORTH WINDS 15-20 KT
ARE EXPECTED DURING THE DAYLIGHT HOURS TODAY...WITH A SHORT PERIOD
WIND CHOP GRADUALLY BUILDING THROUGH THE AFTERNOON. SPECTRAL WAVE
PLOTS FROM FRYING PAN SHOALS SHOW THAT THE SHORT PERIOD WAVES NOW
"OUTWEIGH" THE MODEST SOUTHEAST SWELL WE HAVE BEEN RECEIVING SINCE
YESTERDAY...MAKING CONDITIONS QUITE ROUGH ALREADY FOR MARINERS. THE
SMALL CRAFT ADVISORY REMAINS IN EFFECT BEGINNING AT 4 PM TODAY.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 AM SATURDAY...PERIOD WILL BEGIN WITH NE WINDS RUNNING 20
TO 25 KT AS HIGH PRESSURE BUILDS IN FROM THE NW. WINDS WILL
GRADUALLY DIMINISH TO AROUND 15 KT THROUGH THE PERIOD AND TURN
TOWARD THE NORTH MONDAY NIGHT. SEAS OF 5 TO 7 FEET SUNDAY WILL
SUBSIDE TO 3 TO 4 FT BY MONDAY NIGHT WITH A FEW 5 FOOTERS STILL
POSSIBLE NEAR FRYING PAN SHOALS. SMALL CRAFT FLAGS WILL BE FLYING
FOR SUNDAY AND MAY NEED EXTENDED INTO SUNDAY NIGHT.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 3 AM SATURDAY...LIGHT N TO NW WINDS TUESDAY WILL CONTINUE
INTO WEDNESDAY BEFORE BECOMING W-SW BY WEDNESDAY NIGHT. SEAS WILL
SUBSIDE FROM 3 TO 4 FT TUESDAY MORNING TO 3 FT OR LESS BY WEDNESDAY
NIGHT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 7 PM EST
SUNDAY FOR AMZ250-252-254-256.
&&
$$
SYNOPSIS...31
NEAR TERM...TRA
SHORT TERM...31
LONG TERM...31
AVIATION...JDW
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
944 AM EST SAT DEC 10 2011
.SYNOPSIS...
COLD AND DRY CONDITIONS WILL DEVELOP TODAY AND PERSIST THROUGH
TUESDAY AS ARCTIC HIGH PRESSURE MOVES TO OUR NORTH. WARMING
TEMPERATURE ARE EXPECTED WEDNESDAY THROUGH FRIDAY AS HIGH PRESSURE
MOVES OFFSHORE.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM SATURDAY...THE NORTHERN AND SOUTHERN BRANCHES OF THE
JET STREAM ARE COMBINING FORCES ACROSS THE EASTERN U.S. THIS MORNING
AS A STRONG UPPER TROUGH MOVES EAST ACROSS THE GREAT LAKES. A WEAKER
SOUTHERN STREAM VORT MOVING JUST AHEAD OF THE STRONG NORTHERN
STREAM FEATURE IS CROSSING THE CAROLINAS CURRENTLY...HELPING TO
INDUCE A FEW LIGHT SPRINKLES ACROSS THE EASTERN CAROLINAS. THESE
SPRINKLES SHOULD LARGELY DISSIPATE AND/OR MOVE OFF THE COAST WITHIN
THE NEXT HOUR AS THE TROUGH EXITS TO THE EAST.
PLENTY OF LOW CLOUDS WILL LINGER THROUGH THE AFTERNOON ALONG THE
COAST...BUT INLAND AREAS SHOULD CLEAR OUT AS THE WESTERLY FLOW ABOVE
850 MB BRINGS DRIER AIR IN. JET STREAM CIRRUS WILL LINGER THROUGH
THE DAY AS WELL...BUT MODELS SHOW EVEN THAT MOISTURE PLUME EXITING
THE COAST (TEMPORARILY) THIS EVENING.
THE LARGEST FORECAST CONCERN TODAY IS HIGH TEMPERATURES. INCREASING
COLD ADVECTION WILL COUNTER MOST OF THE SUNSHINE THAT CAN SNEAK
THROUGH THE CLOUDS TODAY...CREATING ONLY A SLOWLY RISING TEMPERATURE
CURVE FOR MOST AREAS. HIGHS WILL PROBABLY ONLY REACH THE MID TO
UPPER 50S TODAY...NOT EVEN A 10 DEGREE RISE FROM CURRENT READINGS.
THE LATEST HRRR DID NOT INITIALIZE TOO PARTICULARLY WELL WITH
TEMPERATURES SO WE HAVE MADE NO SIGNIFICANT CHANGES TO THE HIGH TEMP
FORECAST NOW...BUT WILL MONITOR HOURLY TEMPERATURES CLOSELY FOR
LATER UPDATES.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 AM FRIDAY...HIGH PRESSURE WILL EXTEND INTO THE AREA
THROUGH THE PERIOD WHILE AN OLD FRONTAL BOUNDARY LINGERS OFF THE
COAST. THE FRONT WILL BE CLOSE ENOUGH SUNDAY NIGHT INTO MONDAY TO
YIELD AN INCREASE IN CLOUDS. THERE IS ALSO AN OUTSIDE SHOT FOR
LIGHT RAIN BUT THE PROBABILITY IS LOW ENOUGH PRESENTLY THAT NO
MENTION OF RAIN WILL BE MADE IN THE FORECAST. DECREASING CLOUDS ARE
ON TAP FOR MONDAY AFTERNOON AND NIGHT. BELOW NORMAL TEMPERATURES
EXPECTED BOTH DAYS WITH HIGHS IN THE LOW TO MID 50S SUNDAY AND MID
TO UPPER 50S MONDAY. LOWS EACH NIGHT WILL BE IN THE 30S.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 3 AM FRIDAY...IN GENERAL...HIGH PRESSURE WILL CONTROL AREA
WEATHER THROUGH THE PERIOD. THE RESULT WILL BE FAIR WEATHER AND A
WARMING TREND. ONE POTENTIAL FLY IN THE OINTMENT WILL TAKE THE FORM
OF A COLD FRONT APPROACHING FROM THE NORTH ALONG ABOUT THURSDAY
AFTERNOON. LATEST GUIDANCE KEEPS THIS FRONT WELL TO OUR NORTH BUT
IT IS POSSIBLE THAT IT COULD GET CLOSE ENOUGH TO INCREASE CLOUD
COVER AND BRING A CHANCE OF SHOWERS THURSDAY NIGHT.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 12Z...HIGH CONFIDENCE IN VFR THROUGH THE VALID PERIOD.
WIDESPREAD 5-7 KFT CLOUDINESS AND SOME VERY LIGHT SHOWERS CURRENTLY
IMPACTING THE EASTERN CAROLINAS. THESE CLOUDS AND PRECIP ARE
ASSOCIATED WITH A MID LEVEL TROUGH WHICH WILL ROTATE ACROSS THE AREA
THROUGH THIS AFTN. HAVE MENTIONED TEMPO -SHRA FOR THE FIRST FEW
HOURS AT ALL THE TERMINALS...BUT INTENSITY WILL BE LIGHT ENOUGH THAT
VFR WILL PERSIST EVEN DURING ANY RAINFALL. AS THE TROUGH MOVE EAST
THROUGH THE DAY...SKY CONDITIONS WILL IMPROVE...BECOMING SKC TONIGHT
INLAND...WITH JUST REMAINING CI AT THE COAST.
WINDS THROUGH THE DAY WILL BE PREDOMINANTLY FROM THE NORTH AT 8 TO
12 KTS. PG TIGHTENS OVERNIGHT AHEAD OF ADVANCING HIGH PRESSURE FROM
THE NORTH...SO N WINDS OF 4-8 KTS WILL PERSIST THROUGH 12Z SUNDAY.
EXTENDED OUTLOOK...LOW CONFIDENCE IN SHOWERS AND STRATUS SUNDAY
NIGHT INTO MONDAY MORNING...ESPECIALLY NEAR THE COAST. OTRW...VFR
THROUGH THE EXTENDED.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM SATURDAY...COLD AIR IS BUILDING INTO THE AREA THIS
MORNING AS ARCTIC HIGH PRESSURE OVER MISSOURI/SOUTHERN ILLINOIS
BUILDS EAST. THE PRESSURE GRADIENT WILL REALLY INCREASE TONIGHT AS
THE HIGH MOVES INTO THE OHIO VALLEY...CAUSING OUR WIND SPEEDS TO
INCREASE TO A SOLID 25 KT AWAY FROM SHORE WITH HIGHER GUSTS. UNTIL
THEN...NORTH WINDS 15-20 KT ARE EXPECTED DURING THE DAYLIGHT HOURS
TODAY...WITH A SHORT PERIOD WIND CHOP GRADUALLY BUILDING THROUGH THE
AFTERNOON. SPECTRAL WAVE PLOTS FROM FRYING PAN SHOALS SHOW THAT THE
SHORT PERIOD WAVES NOW "OUTWEIGH" THE MODEST SOUTHEAST SWELL WE HAVE
BEEN RECEIVING SINCE YESTERDAY...MAKING CONDITIONS QUITE ROUGH
ALREADY FOR MARINERS. THE SMALL CRAFT ADVISORY REMAINS IN EFFECT
BEGINNING AT 4 PM TODAY.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 AM SATURDAY...PERIOD WILL BEGIN WITH NE WINDS RUNNING 20
TO 25 KT AS HIGH PRESSURE BUILDS IN FROM THE NW. WINDS WILL
GRADUALLY DIMINISH TO AROUND 15 KT THROUGH THE PERIOD AND TURN
TOWARD THE NORTH MONDAY NIGHT. SEAS OF 5 TO 7 FEET SUNDAY WILL
SUBSIDE TO 3 TO 4 FT BY MONDAY NIGHT WITH A FEW 5 FOOTERS STILL
POSSIBLE NEAR FRYING PAN SHOALS. SMALL CRAFT FLAGS WILL BE FLYING
FOR SUNDAY AND MAY NEED EXTENDED INTO SUNDAY NIGHT.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 3 AM SATURDAY...LIGHT N TO NW WINDS TUESDAY WILL CONTINUE
INTO WEDNESDAY BEFORE BECOMING W-SW BY WEDNESDAY NIGHT. SEAS WILL
SUBSIDE FROM 3 TO 4 FT TUESDAY MORNING TO 3 FT OR LESS BY WEDNESDAY
NIGHT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 7 PM EST
SUNDAY FOR AMZ250-252-254-256.
&&
$$
SYNOPSIS...31
NEAR TERM...TRA
SHORT TERM...31
LONG TERM...31
AVIATION...JDW
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
449 PM EST SAT DEC 10 2011
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE REGION THIS WEEKEND AND PROVIDE
FAIR AND DRY WEATHER THROUGH TUESDAY. SHOWERS ARE POSSIBLE DURING
THE MIDDLE OF THE WEEK. HIGH PRESSURE SHOULD RETURN BY NEXT
WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
WIDESPREAD BKN /ALBEIT RATHER SHALLOW/ STRATO CU PRODUCING SCATTERED
FLURRIES SEEN ACROSS THE NRN HALF OF PENN LATE THIS MORNING VIA A
FAIRLY WELL ALIGNED 290 MEAN BLYR FLOW.
THE SCENT VALLEYS WILL STAY MOSTLY SUNNY THIS AFTERNOON AS THE
COOLEST 850-500 MB TEMPS /AND BEST FETCH OF MOISTURE OFF LAKE ERIE/
SLIDE EAST ACROSS NRN PENN AND NEW YORK STATE.
LOCAL LAKE EFFECT TOOL AND LATEST 15Z RUC INDICATES THE
CURRENT...BKN WEAK LES BANDS CONSOLIDATING SOMEWHAT AND MOVING
FURTHER INLAND ON MORE OF A 27O DEG AXIS. THIS WILL BRING UP TO A
FEW INCHES OF ACCUM TO NWRN WARREN COUNTY...WHILE SURROUNDING
LOCATIONS THROUGHOUT WARREN...MCKEAN AND POTTER COUNTIES SEE JUST
A LIGHT COATING TO ONE INCH.
MAX TEMPS THIS AFTERNOON RANGING FROM THE MID TO UPPER 20S ACROSS
THE NW MTNS...TO AROUND 40 IN THE SE ZONES WILL BE 3-5F BELOW
NORMAL ACROSS THE SUSQ VALLEY...AND UP TO 7 OR 8F BELOW NORMAL
ACROSS THE MTNS.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
LAKE EFFECT SHSN SHOULD DIMINISH AND HALT BEFORE A POSSIBLE RE-
DEVELOPMENT THIS EVENING/EARLY TONIGHT. THIS WILL BE DUE TO THE
BACKING FLOW AT THE LOW LEVELS WHILE 8H FLOW STAYS WNW FOR MOST OF
THE NIGHT. THIS IS KIND OF TYPICAL...AS PAST EXPERIENCE INDICATES
THAT WE OFTEN GET A LAST GASP BAND AS THE WAA BEGINS AND PINCHES
THE LINGERING MOISTURE IN A NARROW BAND OF CONVERGENCE LIFTING
NEWRD. ANY SHSN TONIGHT SHOULD BE NORTH OF ROUTE 6. THE CLEARING
THAT BECOMES NEARLY COMPLETE BY SUNRISE SUN AM WILL HELP THE TEMPS
DROP INTO THE TEENS EVERYWHERE ACROSS THE CWA. THE TYPICAL COLD
AIR DRAINAGE SITES LIKE KSEG/KTHV COULD BE 2-5F LOWER THAN
NEIGHBORING SITES.
THE NEXT FEW DAYS ARE THEN ABSOLUTELY UNEVENTFUL...WITH ABUNDANT
SUNSHINE THANKS TO THE GIANT 1038MB HIGH WHICH KEEPS ALL MOISTURE
AT BAY UNTIL LATER TUESDAY. THE TEMPS ON SUNDAY WILL ONLY REBOUND
TO A FEW DEGS MILDER THAN SAT AS WEAK WAA BEGINS. OVERNIGHT MINS
WILL MOST LIKELY BE MILDER ON THE RIDGES IN THE W WHERE WINDS MAY
STAY UP JUST A BIT VS THE CALM WINDS TO THE EAST. MONDAY LOOKS
LIKE NORMAL MAXES DESPITE ANOTHER CHILLY START. HIGH CLOUDS MAY
TRY TO MOVE OVERHEAD ON TUESDAY...BUT IT WILL STILL BE MOSTLY
SUNNY AND A FEW MORE DEGS WILL BE ADDED TO THE MAXES.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
NRN STREAM FRONT DROPS DOWN THROUGH NY STATE ON TUES NIGHT...AND
MAY MAKE IT INTO PA. BUT...THE HIGH WILL BE SITTING OVER THE
ENTIRE EASTERN SIDE OF THE CONTINENT AND SHOULD FEND IT OFF.
NO REAL MOISTURE WITH THAT BACKDOOR FRONT ANYWAY. WAA AND
INCREASING GULF MOISTURE TO OUR WEST WILL BRING AT LEAST SOME
LOWERED CLOUDS OVERHEAD TUES NIGHT/WED AS WARM FRONT WORKS TO THE
NORTH THROUGH THE OH VALLEY AND INTO THE LOWER GREAT LAKES. SO WE
SHOULD SEE SOME CHC OF A BRIEF SHOWER FROM TUES NIGHT INTO
WED...BUT BULK OF THE TIME WILL BE DRY.
GIANT STORM WILL DEEPEN OVER THE MS VALLEY AND GO INTO THE UPPER
GREAT LAKES ON THURS. THIS WILL LEAD TO ANOTHER ROUND OF RATHER
STRONG SW FLOW LOCALLY ON THU...BUT SHOWERS SHOULD HOLD OFF UNTIL
THU NIGHT WITH COLD FRONT.
THE AIRMASS BEHIND THE FRONT IS NOT REAL COLD...HEIGHTS ARE QUITE
HIGH...THUS NOT SEEING MUCH IF ANY LAKE EFFECT WITH SW FLOW BEHIND
THE COLD FRONT. PATTERN DIFFS BETWEEN GFS AND ECMWF AT LONGEST
RANGES WILL KEEP UNCERTAINTY HIGH AND SLIGHT/LOW CHC POPS IN FOR
DAY7.
&&
.AVIATION /22Z SATURDAY THROUGH THURSDAY/...
HIGH PRESSURE OVER THE OHIO VALLEY WILL BUILD INTO CENTRAL PA
OVERNIGHT...BRINGING DIMINISHING WINDS AND CLEAR SKIES TO MOST OF
THE AREA. A WEST FLOW OFF OF LK ERIE COULD PRODUCE MVFR CIGS AND A
FEW FLURRIES AT BFD THROUGH LATE EVENING. HOWEVER...EVEN THERE
SKIES SHOULD CLEAR BY 06Z...AS FLOW SHIFTS TO THE WSW.
A HIGH CONFIDENCE FORECAST OF VFR AND LIGHT WINDS CONTINUES
THROUGH SUNDAY...AS HIGH PRESSURE PASSES OVER THE STATE.
OUTLOOK...
SUN-TUE...NO SIG WX/VFR.
WED...CHC OF A SHOWER...VFR/MVFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT/CERU
SHORT TERM...LAMBERT/CERU
LONG TERM...LAMBERT
AVIATION...FITZGERALD/CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
232 PM EST SAT DEC 10 2011
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE REGION THIS WEEKEND AND PROVIDE
FAIR AND DRY WEATHER THROUGH TUESDAY. SHOWERS ARE POSSIBLE DURING
THE MIDDLE OF THE WEEK. HIGH PRESSURE SHOULD RETURN BY NEXT
WEEKEND.
&&
.NEAR TERM /UNTIL 7 PM THIS EVENING/...
WIDESPREAD BKN /ALBEIT RATHER SHALLOW/ STRATO CU PRODUCING SCATTERED
FLURRIES SEEN ACROSS THE NRN HALF OF PENN LATE THIS MORNING VIA A
FAIRLY WELL ALIGNED 290 MEAN BLYR FLOW.
THE SCENT VALLEYS WILL STAY MOSTLY SUNNY THIS AFTERNOON AS THE
COOLEST 850-500 MB TEMPS /AND BEST FETCH OF MOISTURE OFF LAKE ERIE/
SLIDE EAST ACROSS NRN PENN AND NEW YORK STATE.
LOCAL LAKE EFFECT TOOL AND LATEST 15Z RUC INDICATES THE
CURRENT...BKN WEAK LES BANDS CONSOLIDATING SOMEWHAT AND MOVING
FURTHER INLAND ON MORE OF A 27O DEG AXIS. THIS WILL BRING UP TO A
FEW INCHES OF ACCUM TO NWRN WARREN COUNTY...WHILE SURROUNDING
LOCATIONS THROUGHOUT WARREN...MCKEAN AND POTTER COUNTIES SEE JUST
A LIGHT COATING TO ONE INCH.
MAX TEMPS THIS AFTERNOON RANGING FROM THE MID TO UPPER 20S ACROSS
THE NW MTNS...TO AROUND 40 IN THE SE ZONES WILL BE 3-5F BELOW
NORMAL ACROSS THE SUSQ VALLEY...AND UP TO 7 OR 8F BELOW NORMAL
ACROSS THE MTNS.
&&
.SHORT TERM /7 PM THIS EVENING THROUGH TUESDAY/...
LAKE EFFECT SHSN SHOULD DIMINISH AND HALT BEFORE A POSSIBLE RE-
DEVELOPMENT THIS EVENING/EARLY TONIGHT. THIS WILL BE DUE TO THE
BACKING FLOW AT THE LOW LEVELS WHILE 8H FLOW STAYS WNW FOR MOST OF
THE NIGHT. THIS IS KIND OF TYPICAL...AS PAST EXPERIENCE INDICATES
THAT WE OFTEN GET A LAST GASP BAND AS THE WAA BEGINS AND PINCHES
THE LINGERING MOISTURE IN A NARROW BAND OF CONVERGENCE LIFTING
NEWRD. ANY SHSN TONIGHT SHOULD BE NORTH OF ROUTE 6. THE CLEARING
THAT BECOMES NEARLY COMPLETE BY SUNRISE SUN AM WILL HELP THE TEMPS
DROP INTO THE TEENS EVERYWHERE ACROSS THE CWA. THE TYPICAL COLD
AIR DRAINAGE SITES LIKE KSEG/KTHV COULD BE 2-5F LOWER THAN
NEIGHBORING SITES.
THE NEXT FEW DAYS ARE THEN ABSOLUTELY UNEVENTFUL...WITH ABUNDANT
SUNSHINE THANKS TO THE GIANT 1038MB HIGH WHICH KEEPS ALL MOISTURE
AT BAY UNTIL LATER TUESDAY. THE TEMPS ON SUNDAY WILL ONLY REBOUND
TO A FEW DEGS MILDER THAN SAT AS WEAK WAA BEGINS. OVERNIGHT MINS
WILL MOST LIKELY BE MILDER ON THE RIDGES IN THE W WHERE WINDS MAY
STAY UP JUST A BIT VS THE CALM WINDS TO THE EAST. MONDAY LOOKS
LIKE NORMAL MAXES DESPITE ANOTHER CHILLY START. HIGH CLOUDS MAY
TRY TO MOVE OVERHEAD ON TUESDAY...BUT IT WILL STILL BE MOSTLY
SUNNY AND A FEW MORE DEGS WILL BE ADDED TO THE MAXES.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
NRN STREAM FRONT DROPS DOWN THROUGH NY STATE ON TUES NIGHT...AND
MAY MAKE IT INTO PA. BUT...THE HIGH WILL BE SITTING OVER THE
ENTIRE EASTERN SIDE OF THE CONTINENT AND SHOULD FEND IT OFF.
NO REAL MOISTURE WITH THAT BACKDOOR FRONT ANYWAY. WAA AND
INCREASING GULF MOISTURE TO OUR WEST WILL BRING AT LEAST SOME
LOWERED CLOUDS OVERHEAD TUES NIGHT/WED AS WARM FRONT WORKS TO THE
NORTH THROUGH THE OH VALLEY AND INTO THE LOWER GREAT LAKES. SO WE
SHOULD SEE SOME CHC OF A BRIEF SHOWER FROM TUES NIGHT INTO
WED...BUT BULK OF THE TIME WILL BE DRY.
GIANT STORM WILL DEEPEN OVER THE MS VALLEY AND GO INTO THE UPPER
GREAT LAKES ON THURS. THIS WILL LEAD TO ANOTHER ROUND OF RATHER
STRONG SW FLOW LOCALLY ON THU...BUT SHOWERS SHOULD HOLD OFF UNTIL
THU NIGHT WITH COLD FRONT.
THE AIRMASS BEHIND THE FRONT IS NOT REAL COLD...HEIGHTS ARE QUITE
HIGH...THUS NOT SEEING MUCH IF ANY LAKE EFFECT WITH SW FLOW BEHIND
THE COLD FRONT. PATTERN DIFFS BETWEEN GFS AND ECMWF AT LONGEST
RANGES WILL KEEP UNCERTAINTY HIGH AND SLIGHT/LOW CHC POPS IN FOR
DAY7.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
12Z TAFS ADJUSTED FOR CURRENT CONDITIONS.
THE NW FLOW OF COLDER AIR CONTINUES TO ADVECT IN...THE LAKE EFFECT
CONTINUES TO MOVE IN SHORE WHICH WILL ALLOW FOR SEVERAL HOURS OF
SNOW SHOWERS AND FLURRIES. THESE WILL PERSIST UNTIL EARLY
EVENING...IN WHICH THE FLOW WILL BE ABATED AND THE MIXING CUT
OFF. EXPECT ANY LIGHT SNOW TO BE DONE BY 00Z. VFR CONDITIONS WILL
CONTINUE THROUGHOUT THE PERIOD.
HIGH PRESSURE WILL BUILD OVER PA LATE TODAY INTO SUNDAY. VFR
CONDITIONS WILL THEN PREVAIL THROUGH EARLY NEXT WEEK.
OUTLOOK...
SUN-TUE...NO SIG WX/VFR.
WED...CHC OF A SHOWER...VFR/MVFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO/LAMBERT
NEAR TERM...DANGELO/LAMBERT
SHORT TERM...DANGELO/CERU
LONG TERM...DANGELO/MARTIN
AVIATION...CERU/MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1101 AM EST SAT DEC 10 2011
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE REGION THIS WEEKEND AND PROVIDE
FAIR AND DRY WEATHER THROUGH TUESDAY. SHOWERS ARE POSSIBLE DURING
THE MIDDLE OF THE WEEK. HIGH PRESSURE SHOULD RETURN BY NEXT
WEEKEND.
&&
.NEAR TERM /UNTIL 7 PM THIS EVENING/...
WIDESPREAD BKN /ALBEIT RATHER SHALLOW/ STRATO CU PRODUCING SCATTERED
FLURRIES SEEN ACROSS THE NRN HALF OF PENN LATE THIS MORNING VIA A
FAIRLY WELL ALIGNED 290 MEAN BLYR FLOW.
THE SCENT VALLEYS WILL STAY MOSTLY SUNNY THIS AFTERNOON AS THE
COOLEST 850-500 MB TEMPS /AND BEST FETCH OF MOISTURE OFF LAKE ERIE/
SLIDE EAST ACROSS NRN PENN AND NEW YORK STATE.
LOCAL LAKE EFFECT TOOL AND LATEST 15Z RUC INDICATES THE
CURRENT...BKN WEAK LES BANDS CONSOLIDATING SOMEWHAT AND MOVING
FURTHER INLAND ON MORE OF A 27O DEG AXIS. THIS WILL BRING UP TO A
FEW INCHES OF ACCUM TO NWRN WARREN COUNTY...WHILE SURROUNDING
LOCATIONS THROUGHOUT WARREN...MCKEAN AND POTTER COUNTIES SEE JUST
A LIGHT COATING TO ONE INCH.
MAX TEMPS THIS AFTERNOON RANGING FROM THE MID TO UPPER 20S ACROSS
THE NW MTNS...TO AROUND 40 IN THE SE ZONES WILL BE 3-5F BELOW
NORMAL ACROSS THE SUSQ VALLEY...AND UP TO 7 OR 8F BELOW NORMAL
ACROSS THE MTNS.
&&
.SHORT TERM /7 PM THIS EVENING THROUGH TUESDAY/...
LAKE EFFECT SHSN COULD DIMINISH OR HALT BEFORE A POSSIBLE RE-
DEVELOPMENT THIS EVENING/EARLY TONIGHT. THIS WILL BE DUE TO THE
BACKING FLOW AT THE LOW LEVELS WHILE 8H FLOW STAYS WNW FOR MOST OF
THE NIGHT. THIS IS KIND OF TYPICAL...AS PAST EXPERIENCE INDICATES
THAT WE OFTEN GET A LAST GASP BAND AS THE WAA BEGINS AND PINCHES
THE LINGERING MOISTURE IN A NARROW BAND OF CONVERGENCE LIFTING
NEWRD. ANY SHSN TONIGHT SHOULD BE NORTH OF ROUTE 6. THE CLEARING
THAT BECOMES NEARLY COMPLETE BY SUNRISE SUN AM WILL HELP THE TEMPS
DROP INTO THE TEENS EVERYWHERE ACROSS THE CWA. THE TYPICAL COLD
AIR DRAINAGE SITES LIKE KSEG/KTHV COULD BE 2-5F LOWER THAN
NEIGHBORING SITES.
THE NEXT FEW DAYS ARE THEN ABSOLUTELY UNEVENTFUL...WITH ABUNDANT
SUNSHINE THANKS TO THE GIANT 1038MB HIGH WHICH KEEPS ALL MOISTURE
AT BAY UNTIL LATER TUESDAY. THE TEMPS ON SUNDAY WILL ONLY REBOUND
TO A FEW DEGS MILDER THAN SAT AS WEAK WAA BEGINS. OVERNIGHT MINS
WILL MOST LIKELY BE MILDER ON THE RIDGES IN THE W WHERE WINDS MAY
STAY UP JUST A BIT VS THE CALM WINDS TO THE EAST. MONDAY LOOKS
LIKE NORMAL MAXES DESPITE ANOTHER CHILLY START. HIGH CLOUDS MAY
TRY TO MOVE OVERHEAD ON TUESDAY...BUT IT WILL STILL BE MOSTLY
SUNNY AND A FEW MORE DEGS WILL BE ADDED TO THE MAXES.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
NRN STREAM FRONT DROPS DOWN THROUGH NY STATE ON TUES NIGHT...AND
MAY MAKE IT INTO PA. BUT...THE HIGH WILL BE SITTING OVER THE
ENTIRE EASTERN SIDE OF THE CONTINENT AND SHOULD FEND IT OFF.
NO REAL MOISTURE WITH THAT BACKDOOR FRONT ANYWAY. WAA AND
INCREASING GULF MOISTURE TO OUR WEST WILL BRING AT LEAST SOME
LOWERED CLOUDS OVERHEAD TUES NIGHT/WED AS WARM FRONT WORKS TO THE
NORTH THROUGH THE OH VALLEY AND INTO THE LOWER GREAT LAKES. SO WE
SHOULD SEE SOME CHC OF A BRIEF SHOWER FROM TUES NIGHT INTO
WED...BUT BULK OF THE TIME WILL BE DRY.
GIANT STORM WILL DEEPEN OVER THE MS VALLEY AND GO INTO THE UPPER
GREAT LAKES ON THURS. THIS WILL LEAD TO ANOTHER ROUND OF RATHER
STRONG SW FLOW LOCALLY ON THU...BUT SHOWERS SHOULD HOLD OFF UNTIL
THU NIGHT WITH COLD FRONT.
THE AIRMASS BEHIND THE FRONT IS NOT REAL COLD...HEIGHTS ARE QUITE
HIGH...THUS NOT SEEING MUCH IF ANY LAKE EFFECT WITH SW FLOW BEHIND
THE COLD FRONT. PATTERN DIFFS BETWEEN GFS AND ECMWF AT LONGEST
RANGES WILL KEEP UNCERTAINTY HIGH AND SLIGHT/LOW CHC POPS IN FOR
DAY7.
&&
.AVIATION /16Z SATURDAY THROUGH WEDNESDAY/...
12Z TAFS ADJUSTED FOR CURRENT CONDITIONS.
THE NW FLOW OF COLDER AIR CONTINUES TO ADVECT IN...THE LAKE EFFECT
CONTINUES TO MOVE IN SHORE WHICH WILL ALLOW FOR SEVERAL HOURS OF
SNOW SHOWERS AND FLURRIES. THESE WILL PERSIST UNTIL EARLY
EVENING...IN WHICH THE FLOW WILL BE ABATED AND THE MIXING CUT
OFF. EXPECT ANY LIGHT SNOW TO BE DONE BY 00Z. VFR CONDITIONS WILL
CONTINUE THROUGHOUT THE PERIOD.
HIGH PRESSURE WILL BUILD OVER PA LATE TODAY INTO SUNDAY. VFR
CONDITIONS WILL THEN PREVAIL THROUGH EARLY NEXT WEEK.
OUTLOOK...
SUN-TUE...NO SIG WX/VFR.
WED...CHC OF A SHOWER...VFR/MVFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO/LAMBERT
NEAR TERM...DANGELO/LAMBERT
SHORT TERM...DANGELO
LONG TERM...DANGELO/MARTIN
AVIATION...CERU/MARTIN
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
634 PM CST SUN DEC 11 2011
.UPDATE...
LIGHT RAIN/SPRINKLES CONTINUE MAINLY NORTH OF INTERSTATE 20 AND
EAST OF INTERSTATE 35 THIS EVENING. ADDED THE MENTION OF ISOLATED
LIGHT RAIN WITH A 10 POP OVERNIGHT TO COVER THE EXPECTED LIGHT
PRECIP.
85/NH
&&
.AVIATION...
FOR THE 00Z TAFS...POTENTIAL FOR MVFR CIGS MONDAY IS THE PRIMARY
AVIATION WEATHER CONCERN.
EAST TO SOUTHEASTERLY WINDS NEAR THE SURFACE WILL CONTINUE TO
REINFORCE A SHALLOW DRY AIRMASS IN PLACE OVER MUCH OF NORTH TX.
MOISTURE AND WARM AIR ADVECTION ALOFT WILL CONTINUE TO SPREAD EAST
OVERNIGHT. THIS WILL BRING IN A LOW VFR STRATA CU DECK OVER MUCH
OF NORTH TX BY EARLY MONDAY MORNING. LATEST NAM AND RUC FORECAST
SOUNDINGS INDICATE THAT MOIST ISENTROPIC LIFT WILL EXIST OVER
NORTH TX FROM MONDAY MORNING THRU THE EARLY AFTERNOON HRS IN THE
H850 TO H700 LAYER. THIS WILL LIKELY PROMOTE THE DEVELOPMENT OF
VERY LIGHT RAINFALL THROUGHOUT THE DAY. SHALLOW DRY AIRMASS WILL
REMAIN IN PLACE HOWEVER...SO MUCH OF THIS LIGHT PRECIPITATION WILL
EVAPORATE BEFORE REACHING THE GROUND. EVAPORATING PRECIP WILL
LIKELY LOWER CLOUD BASES TO MVFR LEVELS BEGINNING MONDAY MORNING.
ISENTROPIC LIFT SHIFTS WEST MONDAY AFTERNOON...AND WE SHOULD SEE A
RISE IN CIGS BACK TO VFR LEVELS AS A RESULT. WILL NOT MENTION RAIN
IN THE TAFS AT THIS TIME AS THERE IS LOW CONFIDENCE IN
PRECIPITATION REACHING THE GROUND AT AREA AIRPORTS.
CAVANAUGH
&&
.PREV DISCUSSION... /ISSUED 329 PM CST SUN DEC 11 2011/
CLOUDS CONTINUE TO INCREASE FROM WEST TO EAST AS WEAK ISENTROPIC
LIFT SPREADS ACROSS THE REGION. A FEW ELEVATED SHOWERS ARE
OCCURRING WITH THIS ASCENT...BUT DRY AIR IN THE LOW LEVELS IS
PREVENTING THIS FROM REACHING THE SURFACE AS ANYTHING MORE THAN
SPRINKLES. THE ISENTROPIC LIFT WILL CONTINUE THROUGH THE NEXT
COUPLE OF DAYS AND ENSURE GENERALLY CLOUDY SKIES. RAIN CHANCES
WILL REMAIN MINIMAL THROUGH TUESDAY AS THE ISENTROPIC UPGLIDE WILL
BE CONFINED TO A RATHER SHALLOW AND STABLE LAYER. ALSO A STUBBORN
LAYER OF DRY AIR WILL EXIST IN THE LOWEST FEW THOUSAND FEET. HIGH
TEMPS WILL REMAIN COOL DUE TO THE CLOUD COVER...BUT LOWS WILL
MODERATE EACH NIGHT. BY LATE TUESDAY...A WARM FRONT WILL HAVE
MOVED THROUGH THE CWA...WITH STEADY OR RISING TEMPS EXPECTED
TUESDAY NIGHT. SOME WEAK SHOWERS/DRIZZLE ARE POSSIBLE TUESDAY
NIGHT AS LOW LEVEL SATURATION FINALLY OCCURS.
AN UPPER LEVEL LOW OFF THE COAST OF CALIFORNIA WILL MOVE INTO THE
PLAINS ON WEDNESDAY. MODEL GUIDANCE HAS UNANIMOUSLY TRENDED THE
UPPER TROUGH WEAKER WHEN IT MOVES THROUGH THE PLAINS...AS INTENSE
SUBTROPICAL HIGH MAINTAINS OVER THE GULF OF MEXICO. 500 MB HEIGHT
FIELDS EXHIBIT LITTLE CYCLONIC CURVATURE AND DYNAMIC FORCING WILL
BE VERY WEAK ACROSS NORTH TEXAS. IN ADDITION THE TRAILING PACIFIC
COLD FRONT LOOKS MUCH WEAKER...AND THUS LOW LEVEL CONVERGENCE IS
NOT IMPRESSIVE EITHER. STILL EXPECT SOME CONVECTION TO DEVELOP
WEDNESDAY ALONG THE WIND SHIFT...BUT THE LINE MAY BE THIN OR
BROKEN INITIALLY. HAVE LOWERED POPS A BIT AS A RESULT OF THESE
CONCERNS. SHEAR IS IMPRESSIVE...BUT INSTABILITY IS WEAK...AND
THUS SEVERE WEATHER THREAT STILL APPEARS LOW. RAIN CHANCES WILL BE
BETTER OVER THE EAST WEDNESDAY EVENING AS LINE TEMPORARILY STALLS.
RAIN SHOULD CLEAR THE EASTERN CWA BY THURSDAY MORNING...WITH
SLIGHTLY DRIER AND COOLER AIR MOVING IN FROM THE WEST THURSDAY.
FORECAST BEYOND THURSDAY IS VERY UNCERTAIN WITH TREMENDOUS MODEL
VARIABILITY IN THE PRIMARY SYNOPTIC FEATURES. WHAT IS CERTAIN IS
THAT A LARGE TROUGH WILL DEVELOP OVER THE ROCKIES WITH AN UPPER
LEVEL LOW CUTTING OFF ACROSS THE DESERT SOUTHWEST. MODELS DO NOT
AGREE ON WHEN THIS UPPER LOW WILL EJECT EASTWARD OR THE TRACK
THAT IT WILL TAKE. AT THE SAME TIME...THERE IS MODEL SPREAD WITH
RESPECT TO A CANADIAN COLD FRONT...AND WHETHER THE CORE OF THE
HIGH WILL TRAVEL EAST INTO THE GREAT LAKES OR MORE SOUTH INTO THE
MIDWEST. ALL IN ALL...THE CANADIAN MODEL REPRESENTS THE SOLUTION
THAT IS IN THE MIDDLE OF THE PACK WITH THESE FEATURES AND GIVES US
CONFIDENCE THAT FRIDAY THROUGH SUNDAY SHOULD BE WET AND COOL.
WILL UNDERCUT THE MEX FOR HIGHS DUE TO EXPECTED RAIN...AND AM ALSO
BETTING ON THE COLD FRONT TO BE STATIONARY SOUTH OF THE REGION AS
SUPPORTED BY THE CANADIAN AND ECMWF. STRONG ISENTROPIC LIFT AHEAD
OF THE UPPER LOW ON THE COLD SIDE OF THE FRONT WOULD MEAN A
PROLONGED RAIN EVENT. RIGHT NOW IT APPEARS THERMAL PROFILES WILL
STAY WARM ENOUGH FOR ALL RAIN...BUT DYNAMIC COOLING ASSOCIATED
WITH THE UPPER LOW WHEN IT COMES ACROSS WILL NEED TO BE MONITORED.
TR.92
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 41 51 44 59 58 / 5 5 10 10 20
WACO, TX 41 54 45 63 60 / 5 5 10 10 20
PARIS, TX 32 49 41 61 54 / 10 5 10 10 10
DENTON, TX 40 49 42 59 57 / 10 5 10 10 20
MCKINNEY, TX 36 50 43 60 57 / 10 5 10 10 20
DALLAS, TX 41 51 45 60 58 / 5 5 10 10 20
TERRELL, TX 36 51 43 62 57 / 10 5 10 10 10
CORSICANA, TX 38 53 45 63 59 / 5 5 10 10 10
TEMPLE, TX 42 54 45 63 60 / 5 5 10 10 20
MINERAL WELLS, TX 40 51 42 59 57 / 5 5 20 20 20
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
85/85
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
608 PM CST SUN DEC 11 2011
.AVIATION...
FOR THE 00Z TAFS...POTENTIAL FOR MVFR CIGS MONDAY IS THE PRIMARY
AVIATION WEATHER CONCERN.
EAST TO SOUTHEASTERLY WINDS NEAR THE SURFACE WILL CONTINUE TO
REINFORCE A SHALLOW DRY AIRMASS IN PLACE OVER MUCH OF NORTH TX.
MOISTURE AND WARM AIR ADVECTION ALOFT WILL CONTINUE TO SPREAD EAST
OVERNIGHT. THIS WILL BRING IN A LOW VFR STRATA CU DECK OVER MUCH
OF NORTH TX BY EARLY MONDAY MORNING. LATEST NAM AND RUC FORECAST
SOUNDINGS INDICATE THAT MOIST ISENTROPIC LIFT WILL EXIST OVER
NORTH TX FROM MONDAY MORNING THRU THE EARLY AFTERNOON HRS IN THE
H850 TO H700 LAYER. THIS WILL LIKELY PROMOTE THE DEVELOPMENT OF
VERY LIGHT RAINFALL THROUGHOUT THE DAY. SHALLOW DRY AIRMASS WILL
REMAIN IN PLACE HOWEVER...SO MUCH OF THIS LIGHT PRECIPITATION WILL
EVAPORATE BEFORE REACHING THE GROUND. EVAPORATING PRECIP WILL
LIKELY LOWER CLOUD BASES TO MVFR LEVELS BEGINNING MONDAY MORNING.
ISENTROPIC LIFT SHIFTS WEST MONDAY AFTERNOON...AND WE SHOULD SEE A
RISE IN CIGS BACK TO VFR LEVELS AS A RESULT. WILL NOT MENTION RAIN
IN THE TAFS AT THIS TIME AS THERE IS LOW CONFIDENCE IN
PRECIPITATION REACHING THE GROUND AT AREA AIRPORTS.
CAVANAUGH
&&
.PREV DISCUSSION... /ISSUED 329 PM CST SUN DEC 11 2011/
CLOUDS CONTINUE TO INCREASE FROM WEST TO EAST AS WEAK ISENTROPIC
LIFT SPREADS ACROSS THE REGION. A FEW ELEVATED SHOWERS ARE
OCCURRING WITH THIS ASCENT...BUT DRY AIR IN THE LOW LEVELS IS
PREVENTING THIS FROM REACHING THE SURFACE AS ANYTHING MORE THAN
SPRINKLES. THE ISENTROPIC LIFT WILL CONTINUE THROUGH THE NEXT
COUPLE OF DAYS AND ENSURE GENERALLY CLOUDY SKIES. RAIN CHANCES
WILL REMAIN MINIMAL THROUGH TUESDAY AS THE ISENTROPIC UPGLIDE WILL
BE CONFINED TO A RATHER SHALLOW AND STABLE LAYER. ALSO A STUBBORN
LAYER OF DRY AIR WILL EXIST IN THE LOWEST FEW THOUSAND FEET. HIGH
TEMPS WILL REMAIN COOL DUE TO THE CLOUD COVER...BUT LOWS WILL
MODERATE EACH NIGHT. BY LATE TUESDAY...A WARM FRONT WILL HAVE
MOVED THROUGH THE CWA...WITH STEADY OR RISING TEMPS EXPECTED
TUESDAY NIGHT. SOME WEAK SHOWERS/DRIZZLE ARE POSSIBLE TUESDAY
NIGHT AS LOW LEVEL SATURATION FINALLY OCCURS.
AN UPPER LEVEL LOW OFF THE COAST OF CALIFORNIA WILL MOVE INTO THE
PLAINS ON WEDNESDAY. MODEL GUIDANCE HAS UNANIMOUSLY TRENDED THE
UPPER TROUGH WEAKER WHEN IT MOVES THROUGH THE PLAINS...AS INTENSE
SUBTROPICAL HIGH MAINTAINS OVER THE GULF OF MEXICO. 500 MB HEIGHT
FIELDS EXHIBIT LITTLE CYCLONIC CURVATURE AND DYNAMIC FORCING WILL
BE VERY WEAK ACROSS NORTH TEXAS. IN ADDITION THE TRAILING PACIFIC
COLD FRONT LOOKS MUCH WEAKER...AND THUS LOW LEVEL CONVERGENCE IS
NOT IMPRESSIVE EITHER. STILL EXPECT SOME CONVECTION TO DEVELOP
WEDNESDAY ALONG THE WIND SHIFT...BUT THE LINE MAY BE THIN OR
BROKEN INITIALLY. HAVE LOWERED POPS A BIT AS A RESULT OF THESE
CONCERNS. SHEAR IS IMPRESSIVE...BUT INSTABILITY IS WEAK...AND
THUS SEVERE WEATHER THREAT STILL APPEARS LOW. RAIN CHANCES WILL BE
BETTER OVER THE EAST WEDNESDAY EVENING AS LINE TEMPORARILY STALLS.
RAIN SHOULD CLEAR THE EASTERN CWA BY THURSDAY MORNING...WITH
SLIGHTLY DRIER AND COOLER AIR MOVING IN FROM THE WEST THURSDAY.
FORECAST BEYOND THURSDAY IS VERY UNCERTAIN WITH TREMENDOUS MODEL
VARIABILITY IN THE PRIMARY SYNOPTIC FEATURES. WHAT IS CERTAIN IS
THAT A LARGE TROUGH WILL DEVELOP OVER THE ROCKIES WITH AN UPPER
LEVEL LOW CUTTING OFF ACROSS THE DESERT SOUTHWEST. MODELS DO NOT
AGREE ON WHEN THIS UPPER LOW WILL EJECT EASTWARD OR THE TRACK
THAT IT WILL TAKE. AT THE SAME TIME...THERE IS MODEL SPREAD WITH
RESPECT TO A CANADIAN COLD FRONT...AND WHETHER THE CORE OF THE
HIGH WILL TRAVEL EAST INTO THE GREAT LAKES OR MORE SOUTH INTO THE
MIDWEST. ALL IN ALL...THE CANADIAN MODEL REPRESENTS THE SOLUTION
THAT IS IN THE MIDDLE OF THE PACK WITH THESE FEATURES AND GIVES US
CONFIDENCE THAT FRIDAY THROUGH SUNDAY SHOULD BE WET AND COOL.
WILL UNDERCUT THE MEX FOR HIGHS DUE TO EXPECTED RAIN...AND AM ALSO
BETTING ON THE COLD FRONT TO BE STATIONARY SOUTH OF THE REGION AS
SUPPORTED BY THE CANADIAN AND ECMWF. STRONG ISENTROPIC LIFT AHEAD
OF THE UPPER LOW ON THE COLD SIDE OF THE FRONT WOULD MEAN A
PROLONGED RAIN EVENT. RIGHT NOW IT APPEARS THERMAL PROFILES WILL
STAY WARM ENOUGH FOR ALL RAIN...BUT DYNAMIC COOLING ASSOCIATED
WITH THE UPPER LOW WHEN IT COMES ACROSS WILL NEED TO BE MONITORED.
TR.92
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 41 51 44 59 58 / 5 5 10 10 20
WACO, TX 41 54 45 63 60 / 5 5 10 10 20
PARIS, TX 32 49 41 61 54 / 5 5 10 10 10
DENTON, TX 40 49 42 59 57 / 5 5 10 10 20
MCKINNEY, TX 36 50 43 60 57 / 5 5 10 10 20
DALLAS, TX 41 51 45 60 58 / 5 5 10 10 20
TERRELL, TX 36 51 43 62 57 / 5 5 10 10 10
CORSICANA, TX 38 53 45 63 59 / 5 5 10 10 10
TEMPLE, TX 42 54 45 63 60 / 5 5 10 10 20
MINERAL WELLS, TX 40 51 42 59 57 / 5 5 20 20 20
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
528 PM CST SUN DEC 11 2011
.SHORT TERM...TONIGHT THROUGH WEDNESDAY
250 PM CST SUN DEC 11 2011
AMPLE CHALLENGES TO THE FORECAST FOR THE NEXT FEW DAYS...WITH THE
FOCUS ON THE PCPN TYPE.
TONIGHT AND MONDAY NOT LOOKING AS CLEAR-CUT AS THE PAST FEW DAYS
SUGGESTED IT WOULD BE...WITH FREEZING DRIZZLE TO DRIZZLE AND BACK
OVER TO FREEZING DRIZZLE. PCPN WILL OCCUR FOR THE REGION...BUT WHAT
FALLS IS MORE HAZY NOW.
LATEST FOG/STRATUS SATELLITE IMAGERY INDICATES AN EXPANSIVE AREA OF
STRATUS MOVING NORTHEAST ACROSS THE PLAINS...SURGING ACROSS THE
LOCAL AREA. THIS WAS IN RESPONSE TO A WARM/MOIST PUSH OF LOW LEVEL
AIR RIDING ACROSS A SNOW PACK. DESPITE WINDS OF 10 KTS OR
GREATER...VSBYS WITH THE STRATUS ARE 2-4 MILES...BRINGING AN ASPECT
OF ADVECTION FOG TO THE FORECAST.
THE FAVORABLE LOW LEVEL MOISTURE TRANSPORT/WARM AIR ADVECTION NOSES
ACROSS THE FORECAST AREA TONIGHT...PERSISTING THROUGH MUCH OF
MONDAY. THIS IS ASSOCIATED WITH AN UPPER LEVEL SHORTWAVE THAT WILL
SPIN FROM THE CENTRAL PLAINS TO ACROSS THE UPPER MISSISSIPPI RIVER
VALLEY BY 18Z MON. THE SATURATION IS ALL IN THE LOW LEVELS
THOUGH...AS EVIDENCED BY TIME/HEIGHT X-SECTIONS AND BUFKIT
SOUNDINGS. AS SUCH...THE DEPTH OF THE SATURATION AND TEMPS AT THE
TOP OF THE ANTICIPATED CLOUD LAYER WILL HAVE AN IMPACT ON THE PCPN
TYPE. PREVIOUS MODEL RUNS POINTED TO NO ICE IN THE CLOUD...THUS
LIQUID AND LIKELY DRIZZLE. HOWEVER...INDICATIONS NOW ARE THAT -10 TO
-12 C COULD BE REALIZED IN CLOUD TOPS...MAKING ICE MORE LIKELY AND
POTENTIALLY SNOW IF THE REST OF THE THERMAL PROFILE WOULD SUPPORT
IT. IN ADDITION...THE SATURATION COULD BECOME DEEP ENOUGH FOR A
PERIOD ON SAT WHERE RAIN WOULD BE MORE LIKELY RATHER THAN DRIZZLE.
ACCUMULATION WOULD STILL BE MINOR...AND BELIEVE DRIZZLE WILL BE THE
MORE PREDOMINANT LIQUID TYPE...SO WILL STAY WITH DRIZZLE FOR NOW.
ANOTHER QUESTION THAT HAS BECOME PROBLEMATIC ARE SFC TEMPS.
PREVIOUSLY FREEZING TEMPERATURES OVERNIGHT/MONDAY MORNING LOOKED
LIKE A SURE THING FOR THE ENTIRE FORECAST AREA. LATEST MODELS RUNS
BRING THIS INTO QUESTION. THE LOW LEVEL WARM AIR ADVECTION WILL NOT
ONLY GO INTO CLOUD/PCPN PRODUCTION LATE TONIGHT...BUT IT SHOULD ALSO
SERVE TO HELP STEADY...OR EVEN RISE...TEMPERATURES OVERNIGHT. IF
THIS OCCURS...WESTERN PARTS OF THE FORECAST AREA HAVE A
PRETTY GOOD CHANCE OF STAYING ABOVE FREEZING. LATEST RUC13 TEMPS AND
LAMP GUIDANCE SUPPORTS THIS...AND HAVE TAILORED TEMPS TONIGHT THIS
WAY. AS A RESULT...THE WESTERN 1/2 OF THE FORECAST AREA WILL LIKELY
MISS OUT ON ANY FREEZING DRIZZLE. FARTHER EAST THOUGH TEMPS HAVE A
MUCH BETTER CHANCE TO COOL TO FREEZING...AND THUS AN ICING THREAT
WHEN THE DRIZZLE MOVES IN. WILL GO WITH A FREEZING RAIN ADV FOR THE
COUNTIES IN THE EAST...ESPECIALLY IN THE I-94 CORRIDOR...FROM 09-15Z
MON.
THIS SCENARIO WILL HAVE TO BE MONITORED VERY CLOSELY TONIGHT...AS
THE AMOUNT OF WARMING AND ONSET OF THE DRIZZLE WILL OBVIOUSLY PLAY
KEY ROLES IN WHERE THE FREEZING DRIZZLE THREAT WILL BE HIGHEST.
AN UPPER LEVEL TROUGH WILL LIFT OUT OF THE DESERT
SOUTHWEST...BRINGING THE TROUGH AXIS ACROSS THE REGION ON WED. THIS
SYSTEM LOOKS LIKE IT COULD PACK A PRETTY GOOD PUNCH WITH GOOD QG
CONVERGENCE...SLOPING FRONTOGENETIC LIFT...AND THE ENERGY FROM THE
UPPER LEVEL SHORTWAVE. TIMING AND POSITIONING WILL PLAY AN IMPORTANT
ROLE AS WARM AIR WILL BE A FACTOR FOR PCPN TYPE.
UNFORTUNATELY...EACH MODEL HAS A DIFFERENT IDEA ON WHAT WILL
OCCUR...AND BRINGS THE FORECAST CONFIDENCE DOWN AS A RESULT. NAM IS
THE QUICKEST OF ALL...TAKING THE SFC LOW TO LAKE SUPERIOR BY 00Z
THU. THE GFS IS OVER SOUTHWEST IA...THE EC THE CENTRAL PLAINS...AND
THE GEM EASTERN IA. A LOT OF INCONSISTENCY WITHIN THE MODELS
TOO...EXCEPT FOR THE EC WHICH SHOWS A BIT BETTER RUN TO RUN
AGREEMENT. WILL LEAN ON THE EC AS A RESULT...BLENDING IT WITH THE
CONSENSUS SOLUTION.
BEFORE THE HEART OF THE SYSTEM MOVES IN WED
AFTERNOON/NIGHT...ANOTHER GOOD SURGE OF LOW LEVEL MOISTURE
TRANSPORT/WARM AIR ADVECTION TUE NIGHT/WED MORNING WILL LIKELY LEAD
TO A BROAD AREA OF PRECIPITATION SPREADING ACROSS PORTIONS OF THE
REGION. SATURATION LOOKS DEEP ENOUGH TO SUPPORT ICE IN THE
CLOUD...BUT WARMING IN THE NEAR SFC LAYER SUGGESTS MELTING AND THE
POTENTIAL FOR RAIN OR FREEZING RAIN. THE WARMING CONTINUES FOR THE
REST OF WED AS THE MAIN PART OF THE STORM MOVES IN...WITH RAIN THE
LIKELY PCPN TYPE AS A RESULT. LOOKS LIKE ANY SNOW BAND WITH THIS
STORM WILL HANG WELL WEST/NORTH. OVERALL...CONFIDENCE IS HIGH THAT
PRECIPITATION WILL OCCUR. WHEN ITS MOST LIKELY IS NOT. CONFIDENCE IS
ALSO RISING THAT IT WILL LIKELY BE RAIN FOR THE MAJORITY OF THE
EVENT.
.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY
250 PM CST SUN DEC 11 2011
MODEL DIFFERENCES CONTINUE...LOWERING CONFIDENCE IN SOME OF THE
DETAILS. WHILE THE GFS HAS MOVED TO A NORTHWEST STORM TRACK ALA THE
ECMWF AND GEM...STILL LOTS OF TIMING VARIANCE ON HOW QUICKLY THE
SYSTEM WILL KICK NORTHEAST. THE GFS IS THE FAST SOLUTION...WITH THE
EC SLOWER AND THE GEM IN BETWEEN. THE EC WOULD LINGER PCPN LONGER
OVER THE FORECAST AREA...CONTINUING INTO THU. ALSO...WITH THE EC
STAYING THE FARTHEST WEST...ITS ALSO MUCH WARMER MAKING RAIN A
MORE LIKELY PCPN TYPE FOR A LONGER STRETCH OF TIME. PCPN TYPE WILL
BE A DIFFICULTY WITH THIS STORM. WILL CONTINUE TO LEAN ON THE
EC/CONSENSUS SOLUTION FOR NOW.
HIGH PRESSURE STARTS TO BUILD IN FROM THE WEST THU NIGHT...MOVING
OVERHEAD FOR SAT WHILE THE UPPER LEVEL FLOW TAKES ON A MORE ZONAL
SHAPE FOR THE WEEKEND. FRI/SAT SHOULD BE DRY WITH SEASONAL TEMPS.
&&
.AVIATION...TONIGHT AND MONDAY
528 PM CST SUN DEC 11 2011
MOISTURE CONTINUES TO WORK INTO THE AREA AND IS RESULTING IN A
BAND OF IFR/MVFR CLOUDS. CEILINGS AT KRST HAVE ALREADY GONE DOWN
TO IFR AND FOR THE MOST PART ARE EXPECTED TO REMAIN THERE THROUGH
THE FORECAST PERIOD. THERE COULD BE A BRIEF BREAK IN THE IFR
CEILINGS THIS EVENING AS DOWNSTREAM SITES HAVE TEMPORARILY GONE UP
TO MVFR. KLSE IS EXPECTED TO GO DOWN TO IFR CEILINGS EARLY THIS
EVENING AS WELL. AS A SHORT WAVE TROUGH COMES IN LATE
TONIGHT...THIS WILL PROVIDE ENOUGH LIFT TO PRODUCE SOME LIGHT
DRIZZLE AT BOTH TAF SITES WITH TEMPERATURES EXPECTED TO STAY ABOVE
FREEZING. CAN NOT TOTALLY RULE OUT AN HOUR OR TWO OF SOME FREEZING
DRIZZLE OVERNIGHT AT KRST BUT CONFIDENCE IS NOT HIGH ENOUGH WHEN
THIS MAY OCCUR TO INCLUDE IN THE FORECAST AT THIS TIME. ONCE THE
DRIZZLE BEGINS...EXPECT THE VISIBILITY AT BOTH SITES TO GO DOWN TO
IFR. SOME MODEST IMPROVEMENT MAY OCCUR MONDAY AFTERNOON AS THE
DRIZZLE BEGINS TO WIND DOWN ALLOWING THE VISIBILITY TO COME UP TO
MVFR.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
250 PM CST SUN DEC 11 2011
WI...FREEZING RAIN ADVISORY FROM 3 AM TO 9 AM CST MONDAY FOR WIZ017-
029-034-042>044-053>055-061.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM... RIECK
LONG TERM.... RIECK
AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1158 AM CST SAT DEC 10 2011
.SHORT TERM...
955 AM CST SAT DEC 10 2011
UPDATED SKY TRENDS TODAY TOWARD CLOUDIER CONDITIONS GIVEN
SOUTHWEST WINDS/WARM AIR ADVECTION OVER THE EXISTING SNOW PACK.
LATEST IR IMAGERY SHOWING STRATUS WITH BASES IN THE 1500-3000FT
RANGE ADVECTING EAST/NORTHEAST ACROSS IA TOWARD THE FORECAST AREA.
MEANWHILE ...MID-LEVEL CLOUDS WERE ADVECTING SOUTHEASTWARD ACROSS
NORTHERN MN TOWARD THE AREA IN ISENTROPIC LIFT AHEAD OF A WARM
FRONT ACROSS THE EASTERN PART OF THE DAKOTAS. RUC MODEL SHOWING
EXPANDING RH IN THE 0.5-1KM LAYER BELOW AN INVERSION THROUGH
TODAY. RESULT IS EXPECTED TO BE AN INCREASE IN STRATUS IN ADDITION
TO THE INCREASE IN ALTOCUMULUS ACROSS THE AREA AS THE DAY WEARS
ON.
.LONG TERM...TUESDAY THROUGH FRIDAY
300 AM CST SAT DEC 10 2011
STILL LOTS OF UNCERTAINTY IN THIS TIME WITH REGARDS TO THE SYSTEM
IN THE WEDNESDAY/THURSDAY TIME FRAME. MODEL TRENDS IN BOTH THE GFS
AND ECMWF IS A SHIFT SOUTHEAST WITH THE SURFACE LOW TRACK. ALONG
WITH SOME TIMING DIFFERENCES. GFS FURTHEST SOUTH TAKING THE LOW
CROSS CENTRAL ILLINOIS...WHILE THE ECMWF LIFTS THE LOW THROUGH IOWA
AND ACROSS SOUTHWEST WISCONSIN. 10.00Z GEM SIDES CLOSER WITH THE
ECMWF WITH LOW TRACKING FROM IOWA INTO SOUTHERN WISCONSIN. OBVIOUSLY
WITH THESE DIFFERENCES THERE IS STILL A QUESTION ON PRECIPITATION
TYPE AND WILL CONTINUE TO MENTION RAIN/SNOW. ACCUMULATING SNOW QUITE
LIKELY FROM THIS...BUT WHERE WILL IT BE IS THE MILLION DOLLAR
QUESTION. MODEL CONSENSUS IS FOR THE HIGHEST PROBABILITIES
WEDNESDAY NIGHT AND THURSDAY. SYSTEM WILL LIFT AWAY FROM THE AREA
FRIDAY WITH COLDER AIR RETURNING TO THE REGION...WITH HIGHS IN THE
20S.
&&
.AVIATION...THROUGH 18Z SUNDAY
1158 AM CST SAT DEC 10 2011
CURRENTLY KEEPING A WATCH ON A MVFR STRATUS DECK MOVING EAST
ACROSS NORTHEAST IA/SOUTHEAST MN. NAM12/RUC MODELED RH FIELDS HAVE A
GOOD HANDLE ON THIS STRATUS DECK AND HAVE IT ADVECTING EAST OF THE
AREA BY LATER THIS AFTERNOON. OTHERWISE...A BAND OF ALTOCUMULUS
WITH CIGS AOA 7KFT WAS MOVING EAST ACROSS NORTHER/CENTRAL WI.
MODELS ALSO HAVE THIS PUSHING EAST OF THE AREA BY LATER THIS
AFTERNOON. WILL THEN SEE A WARM FRONT PUSH EAST ACROSS THE AREA
TONIGHT WITH WINDS STAYING OUT OF THE SOUTH/SOUTHWEST AROUND 15KT
AT KRST...AND AROUND 10KT DOWN IN THE MISSISSIPPI RIVER VALLEY AT
KLSE. THIS RAISES ANOTHER CONCERN AT KLSE ABOUT LOW LEVEL WIND
SHEAR AS WINDS AOA 1000 FEET ARE DEPICTED BY BUFKIT MODEL
SOUNDINGS TO BE AROUND 30-35KT FROM THE WEST/SOUTHWEST. ALTHOUGH
TECHNICALLY NOT ENOUGH CRITERIA FOR WIND SHEAR...PILOTS STILL MAY
EXPERIENCE SOME BUMPINESS ON FINAL APPROACH OR TAKING OFF FROM
KLSE. OTHERWISE...LOOKS LIKE VFR CONDITIONS WILL PREVAIL OVERNIGHT
THROUGH SUNDAY MORNING. LOOKING FURTHER...APPEARS IFR/FREEZING
DRIZZLE THREAT IS INCREASING FOR SUNDAY NIGHT AFTER MIDNIGHT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
300 AM CST SAT DEC 10 2011
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM....RABERDING
AVIATION...DAS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
955 AM CST SAT DEC 10 2011
.SHORT TERM...
955 AM CST SAT DEC 10 2011
UPDATED SKY TRENDS TODAY TOWARD CLOUDIER CONDITIONS GIVEN
SOUTHWEST WINDS/WARM AIR ADVECTION OVER THE EXISTING SNOW PACK.
LATEST IR IMAGERY SHOWING STRATUS WITH BASES IN THE 1500-3000FT
RANGE ADVECTING EAST/NORTHEAST ACROSS IA TOWARD THE FORECAST AREA.
MEANWHILE ...MID-LEVEL CLOUDS WERE ADVECTING SOUTHEASTWARD ACROSS
NORTHERN MN TOWARD THE AREA IN ISENTROPIC LIFT AHEAD OF A WARM
FRONT ACROSS THE EASTERN PART OF THE DAKOTAS. RUC MODEL SHOWING
EXPANDING RH IN THE 0.5-1KM LAYER BELOW AN INVERSION THROUGH
TODAY. RESULT IS EXPECTED TO BE AN INCREASE IN STRATUS IN ADDITION
TO THE INCREASE IN ALTOCUMULUS ACROSS THE AREA AS THE DAY WEARS
ON.
.LONG TERM...TUESDAY THROUGH FRIDAY
300 AM CST SAT DEC 10 2011
STILL LOTS OF UNCERTAINTY IN THIS TIME WITH REGARDS TO THE SYSTEM
IN THE WEDNESDAY/THURSDAY TIME FRAME. MODEL TRENDS IN BOTH THE GFS
AND ECMWF IS A SHIFT SOUTHEAST WITH THE SURFACE LOW TRACK. ALONG
WITH SOME TIMING DIFFERENCES. GFS FURTHEST SOUTH TAKING THE LOW
CROSS CENTRAL ILLINOIS...WHILE THE ECMWF LIFTS THE LOW THROUGH IOWA
AND ACROSS SOUTHWEST WISCONSIN. 10.00Z GEM SIDES CLOSER WITH THE
ECMWF WITH LOW TRACKING FROM IOWA INTO SOUTHERN WISCONSIN. OBVIOUSLY
WITH THESE DIFFERENCES THERE IS STILL A QUESTION ON PRECIPITATION
TYPE AND WILL CONTINUE TO MENTION RAIN/SNOW. ACCUMULATING SNOW QUITE
LIKELY FROM THIS...BUT WHERE WILL IT BE IS THE MILLION DOLLAR
QUESTION. MODEL CONSENSUS IS FOR THE HIGHEST PROBABILITIES
WEDNESDAY NIGHT AND THURSDAY. SYSTEM WILL LIFT AWAY FROM THE AREA
FRIDAY WITH COLDER AIR RETURNING TO THE REGION...WITH HIGHS IN THE
20S.
&&
.AVIATION...TODAY AND TONIGHT
535 AM CST SAT DEC 10 2011
VFR CONDITIONS ARE EXPECTED THROUGH THE FORECAST PERIOD. HIGH
PRESSURE WILL SLIDE EAST OF THE REGION TODAY AS A SURFACE TROUGH
DEVELOPS ACROSS THE NORTHERN PLAINS. LOOK FOR SOUTHWEST WINDS TO
INCREASE INTO THE 12 TO 15 KT RANGE...WITH GUSTS TO AROUND 21 KTS
POSSIBLE. A SCT-BKN CLOUD DECK WITH BASES RANGING FORM 8 TO 12
KFT...WILL MOVE FROM NORTHWEST TO SOUTHEAST ACROSS THE TAF SITES
THIS MORNING INTO THE EARLY AFTERNOON HOURS. LOOK FOR SKIES TO
CLEAR LATE THIS AFTERNOON. FORECAST SOUNDINGS ARE SHOWING LOW
LEVEL MOISTURE INCREASING ACROSS THE AREA THIS EVENING INTO THE
OVERNIGHT HOURS...WITH THE POTENTIAL FOR A LOW STRATUS DECK TO
DEVELOP. WINDS FROM JUST ABOVE THE SURFACE THROUGH 1KFT AT 13 TO
25 KTS...SHOULD PROMOTE ENOUGH MIXING TO INHIBIT LOW STRATUS
DEVELOPMENT BUT WILL HAVE TO CLOSELY MONITOR THIS LATE THIS
AFTERNOON INTO THIS EVENING. VFR CONDITIONS ARE ANTICIPATED DURING
THE OVERNIGHT HOURS...UNLESS THE LOW STRATUS DEVELOPS THEN
MVFR/IFR CONDITIONS WOULD BE POSSIBLE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
300 AM CST SAT DEC 10 2011
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM....RABERDING
AVIATION.....WETENKAMP
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1146 PM CST SUN DEC 11 2011
...UPDATE TO AVIATION...
.DISCUSSION...
LATEST WATER VAPOR LOOP AT 20Z WAS SHOWING THE UPPER TROUGH MOVING
SLOWLY ACROSS THE HIGH PLAINS FROM NEBRASKA INTO THE TEXAS
PANHANDLE. SHOWERS HAVE DEVELOPED OUT AHEAD OF THE WAVE IN OKLAHOMA
TODAY AND HAVE BEEN MOVING NORTHEAST SLOWLY THROUGH THE DAY.
SOUNDING FROM 12Z AT TOP AND SGF SHOWED PLENTY OF DRY AIR OFF THE
DECK THIS MORNING. SOME DRY AIR CONTINUES TO BE ENTRAINED THIS
EVENING IN THE EASTERN CWA PER MODEL TIME SECTIONS. LATEST RUN OF
THE RUC DOES NOT BRING ANY MEASURABLE PRECIPITATION AS FAR NORTH
INTO THE SOUTHERN CWA TONIGHT. THE UPPER WAVE WILL MOVE SLOWLY MOVE
ACROSS THE CENTRAL PLAINS TONIGHT WITH THE UPPER TROUGH AXIS MOVING
THROUGH THE EASTERN CWA BY 09Z MONDAY. 925-850 MB WINDS BECOME SOUTH
EARLY THIS EVENING THEN SOUTHWEST OVERNIGHT AND BY MORNING WILL
FOCUS MOISTURE TO THE EAST. EXPECT CLOUDS TO REMAIN THROUGH THE
NIGHT WITH SOME PATCHY FOG AND DRIZZLE POSSIBLE IN THE NORTHWEST
WHILE SPRINKLES ARE MORE LIKELY IN THE EAST. LOWS TONIGHT WILL
REMAIN ABOVE FREEZING SO NO FREEZING OR FROZEN PRECIPITATION IS
EXPECTED.
MONDAY SOME EARLY MORNING PATCHY DRIZZLE OR FOG IS POSSIBLE OFF THE
SNOW PACK TO THE WEST IN NORTH CENTRAL KANSAS. BY MID MORNING A
FRONTAL BOUNDARY WILL APPROACH FROM THE WEST BUT MAKES SLOW PROGRESS
THROUGH THE DAY AND BECOMES STATIONARY FROM SOUTHEAST NEBRASKA INTO
SOUTHWEST KANSAS. SOUTHERLY FLOW AHEAD OF THE FRONT WILL BRING
TEMPERATURES AGAIN IN THE MID AND UPPER 40S TO THE AREA.
53
MODELS ARE SIMILAR IN TAKING UPPER TROUGH OFF THE SOUTHERN CA COAST
MONDAY EVENING AND EJECTING IT NORTHEASTWARD INTO THE CENTRAL HIGH
PLAINS BY MIDDAY WEDNESDAY...THEN RAPIDLY INTO THE WESTERN GREAT
LAKES BY LATE WEDNESDAY NIGHT. THE MODELS ARE IN LESS AGREEMENT ON
HOW FAR SOUTHEAST THE COLD FRONT WILL PUSH SOUTHEAST INTO THE
NORTHWEST COUNTY WARNING AREA (CWA) MONDAY NIGHT BEFORE
STALLING...WITH THE NAM/SREF THE MOST AGGRESSIVE INTO THE NORTHWEST
1/3 OF THE CWA AND THE GFS/EC NOT BRINGING IT INTO THE NORTHWEST
CORNER AT ALL. WILL COMPROMISE FOR NOW WITH SOME
FREEZING/SUBFREEZING TEMPS IN THE FAR NORTHWEST CORNER BEHIND THE
FRONT AND WARMER ABOVE FREEZING TEMPS ELSEWHERE. WITH A CHANCE FOR
DRIZZLE/LIGHT RAIN INCREASING LATER IN THE NIGHT AND NO NON DIURNAL
TREND EXPECTED...CANNOT RULE OUT A WINDOW FOR SOME LIGHT FREEZING
PRECIP IN THE FAR NORTHWEST CORNER OF THE CWA 06-12Z
TUES...OTHERWISE EXPECT THE PRECIP WITH THIS SYSTEM TO BE A RAIN
EVENT TUESDAY THROUGH WEDNESDAY BEFORE ENDING WEDNESDAY NIGHT.
ELEVATED INSTABILITY AND FORCING LOOK SUFFICIENT FOR SOME THUNDER
POTENTIAL AHEAD OF THE FRONT IN THE DEEPER MOISTURE AXIS ACROSS THE
SOUTHEAST HALF OF THE CWA WHERE THE WARMER MORNING LOWS WEDNESDAY
WILL BE IN THE LOW TO MID 40S. AFTER HIGHS IN THE LOW TO MID 40S ON
TUESDAY...SHOULD SEE HIGHS RISE INTO THE LOW TO MIDDLE 50S FOR
WEDNESDAY.
AFTER THIS SYSTEM EXITS...MODELS DIVERGE THROUGH THE END OF THE WEEK
AND INTO NEXT WEEKEND ON HOW QUICKLY THE NEXT SHORTWAVE TO DIG INTO
THE SOUTHWEST CONUS WILL EJECT OUT INTO THE PLAINS. THE ECMWF MODEL
IS ABOUT 2 DAYS SLOWER WITH ITS ARRIVAL AND ASSOCIATED PRECIP THAN
THE GFS. WITH SUCH LOW CONFIDENCE ON ITS ARRIVAL TIME AND CURRENT
DRY FCST THROUGH SATURDAY...OPTED TO KEEP FCST DRY UNTIL SATURDAY
NIGHT/SUNDAY WITH LOW CHANCES FOR RAIN/FREEZING RAIN OR A SNOW
POTENTIAL. AFTER LOWS IN THE 20S AND HIGHS IN THE 30S BOTH FRIDAY
AND SATURDAY...HIGHS TEMPS SHOULD SLOWLY MODERATE AHEAD OF THE NEXT
UPPER TROUGH INTO THE 40S FOR HIGHS ON SUNDAY. 63
&&
.AVIATION...
VFR CONDITIONS WILL CONTINUE THROUGH MOST OF THE OVERNIGHT HOURS
WITH BKN/OVC CEILINGS OF 4-6KFT. EXPECT CEILINGS TO LOWER BY THE
MORNING HOURS AND BECOME MVFR/NEAR MVFR FOR THE REMAINDER OF THE
PERIOD.
BLAIR
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1121 PM CST SUN DEC 11 2011
.AVIATION...
FOR THE 06Z TAF ISSUANCE...
STATUS CONTINUES TO SPREAD NORTH ACROSS ALL OF THE TAF SITES AS OF
05Z WITH THE 00Z NAM BUFR SOUNDINGS ALSO SUPPORTING A THICKENING
AND LOWERING TREND OF THESE LOW CLOUDS THROUGH THE EARLY MORNING
HOURS. AS THIS STATUS THICKENS AND LOWERS SOME HIGH LEVEL CLOUD
COVER WILL BEGIN TO SPREAD INTO SOUTHWEST KANSAS AS AN UPPER LEVEL
SHORT WAVE TROUGH APPROACHES THE AREA FROM THE SOUTHWEST. AS A
RESULT THIS STATUS WILL BE SLOW TO ERODE SO HAVE DECIDED TO FOLLOW
THE LATEST NAM GUIDANCE, HRRR AND BUFR SOUNDINGS IN KEEPING THESE
LOW CIGS IN PLACE THROUGH AT LEAST LATE MORNING. WINDS WILL
CONTINUE AROUND 20KTS THROUGH MUCH OF THE NIGHT BUT WILL BEGIN TO
SUBSIDE AT OR SHORTLY AFTER 12Z AS A TROUGH OF LOW PRESSURE AT THE
SURFACE STARTS TO MOVE INTO WESTERN KANSAS. GIVEN THESE WINDS SOME
LIGHT FOG WILL BE POSSIBLE BUT AREAS OF DENSE FOG IS NOT
ANTICIPATED. THE POSSIBLE EXCEPTION WILL BE NEAR THE GCK WHERE
WIND SPEEDS ARE EXPECTED BE LIGHTER GIVEN THE CLOSER PROXIMITY TO
THE SURFACE LEE TROUGH EARLY MONDAY MORNING. WILL THEREFORE BE A
LITTLE MORE PESSIMISTIC IN THE VSBYS BETWEEN BETWEEN 12 AND 15Z AT
GCK THAN AT DDC OR HYS. -RB
&&
PREV DISCUSSION... /ISSUED 326 PM CST SUN DEC 11 2011/
DISCUSSION...
DAYS 1-2...
BREEZY SOUTH TO SOUTHWEST WINDS THIS EVENING WILL DECREASE TO AROUND
10 TO 15 MPH BY MORNING. DEWPOINTS ARE ANTICIPATED TO INCREASE A FEW
DEGREES ACROSS EASTERN PORTIONS OF THE CWA AND STRATUS IS EXPECTED
TO REDEVELOP OR CONTINUE, MAINLY ACROSS AREAS EAST OF WAKEENEY TO
LIBERAL. A FEW PLACES MAY EXPERIENCE REDUCED VISIBILITIES DUE TO FOG
AFTER MIDNIGHT, HOWEVER, IT SHOULD NOT BE WIDESPREAD LIKE YESTERDAY.
SOME CIRROSTRATUS IS POSSIBLE ACROSS WESTERN KANSAS AS UPPER LEVEL
MOISTURE MOVES INTO THE PLAINS AHEAD OF THE UPPER LEVEL TROUGH OVER
CALIFORNIA. A COLD FRONT IS EXPECTED TO MOVE SOUTH ACROSS NEBRASKA
INTO NORTHERN KANSAS TOMORROW. MODELS THEN HAVE THIS FRONT STALLING
OUT AND BISECTING OUR CWA IN THE AFTERNOON. LOWER TO MID LEVEL
MOISTURE WILL CONTINUE TO INCREASE ACROSS OUR AREA ALLOWING FOR
MOSTLY CLOUDY SKIES TO PREVAIL. THE FRONTAL BOUNDARY THEN MOVES
NORTH AS A WARM FRONT TOMORROW NIGHT. SOME LIGHT DRIZZLE OR LIGHT
RAIN WILL BE POSSIBLE ACROSS THE EASTERN THIRD OF THE CWA WITH
FREEZING FOG OR FREEZING DRIZZLE POSSIBLE ACROSS THE NORTHWESTERN
PORTION OF THE CWA. MODELS CONTINUE TO INDICATE AN UPPER LEVEL
SHORTWAVE MOVING ACROSS NEW MEXICO AND INTO THE HIGH PLAINS ON
TUESDAY. A STRONG 250MB JET WILL BE FOUND ACROSS OUR AREA AT THIS
TIME ENHANCING LIFT ACROSS THE AREA. THESE FEATURES ARE ANTICIPATED
TO BRING A CHANCE OF RAIN ACROSS MUCH OF THE FORECAST AREA.
OTHERWISE EXPECT MOSTLY CLOUDY SKIES. LOWS TONIGHT ARE ANTICIPATED
TO RANGE FROM THE MID TO UPPER 20S IN THE WEST TO MID 30S ACROSS
EASTERN PORTIONS OF THE CWA. LOWS TOMORROW NIGHT ARE EXPECTED TO
RANGE FROM THE LOWER 30S NORTHWEST TO UPPER 30S SOUTHEAST. HIGHS
MONDAY AND TUESDAY ARE ANTICIPATED TO RANGE FROM THE UPPER 30S
NORTHWEST TO UPPER 40S SOUTHEAST.
DAYS 3-7...
THE MEDIUM RANGE FORECAST WILL START WITH A WARM FRONT STRADDLING
THE CWA ON WEDNESDAY, WITH A SHORT WAVE ALOFT PASSING FROM WEST TO
EAST. RAIN WILL MOSTLY LIKELY FALL WEDNESDAY OVER MOST OF THE CWA.
A FEW THUNDERSTORMS WILL BE POSSIBLE ACROSS THE EXTREME SOUTHEAST
CWA WEDNESDAY AFTERNOON, WITH EITHER FREEZING DRIZZLE OR LIGHT SNOW
MORE POSSIBLE IN OUR EXTREME NORTHWESTERN COUNTIES. THIS SHORT WAVE
IN THE 500MB LEVEL IS SMALL BUT POTENT, AND IT SHOULD KEEP SOME
PRECIP ACROSS OUR EAST UNTIL EARLY WEDNESDAY NIGHT. THURSDAY AND
FRIDAY WILL BE BETWEEN UPPER SYSTEMS AND SHOULD BE DRY. IT WILL
COOL DOWN THURSDAY AND FRIDAY FROM THE HIGHS ON WEDNESDAY IN THE
UPPER 40S NORTHWEST TO THE UPPER 50S IN THE SOUTHEAST. HIGHS BY
FRIDAY WILL ONLY RANGE FROM THE UPPER 30S IN OUR NORTH TO THE MIDDLE
40S ACROSS OUR SOUTH. SATURDAY WILL COOL DOWN DUE TO INCREASING
CLOUDS AND A SLIGHT FOR SNOW MOVING IN FROM THE SOUTH. THE TRACK OF
THE ASSOCIATED UPPER LOW WILL PLAY HEAVILY ON IF AND WHERE WE GET
ANY SNOW. BUT, IT DOES LOOK LIKE THE GEM AND GFS BOTH TRACK THE
UPPER 500 MB LOW DOWN INTO SOUTHWESTERN NEW MEXICO BY SATURDAY, AND
THEN BRING THE LOW NORTHEASTWARD INTO NORTH CENTRAL OKLAHOMA BY
SUNDAY NIGHT. THE EC MODEL IS SLOWER AND A BIT FARTHER SOUTH WITH
THE SYSTEM. ANYWAY, THE CREXTENDED MODEL INITIALLY PLACED 60 POPS
IN MY SOUTHEAST SUNDAY, GRADUATING DOWNWARD TO 30 POPS ACROSS OUR
WEST. I DID LOWER THE POPS TO 40 PERCENT IN OUR SOUTHEAST AND 30
PERCENT IN OUR WEST SUNDAY. THESE POPS CAN BE ADJUSTED UPWARDS OR
DOWNWARDS LATER, AS MODEL TRENDS BECOME MORE RELIABLE. FOR NOW, IF
THE GFS MODEL IS RIGHT, 2 TO 4 INCHES COULD FALL ACROSS A PORTION OF
OUR CWA SATURDAY NIGHT INTO SUNDAY. IF THE EC MODEL IS MORE
CORRECT, THEN JUST OUR SOUTHERN CWA WILL SEE SOME SNOW AND IT WILL
BE LATER THAN SUNDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 35 44 35 46 / 10 20 50 50
GCK 32 42 32 45 / 0 10 40 50
EHA 27 43 37 48 / 10 10 40 40
LBL 34 45 37 49 / 10 10 40 40
HYS 34 41 32 43 / 10 10 40 50
P28 35 47 39 48 / 10 20 50 50
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1240 AM EST MON DEC 12 2011
UPDATED AVIATION DISCUSSION FOR 06Z TAFS
.SYNOPSIS...
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A SPLIT FLOW ACRS
NAMERICA WITH NRN BRANCH RDGING BLDG INTO THE UPR GRT LKS. THESE
RISING HGTS...WITH 00Z-12Z H3 RISES UP TO 150M AT APX...ARE BEING
FORCED BY VIGOROUS WAD IN THE STRONG WSW FLOW /12Z H85 WIND SPEED AT
INL WAS 50KT/ BTWN SFC-H85 HI PRES IN THE MID ATLANTIC STATES AND LO
PRES JUST N OF THE BORDER MOVING E INTO NW ONTARIO THAT IS
ASSOCIATED WITH A SHRTWV NEAR LK WINNIPEG. THIS STRONG WAD HAS
PUSHED H85 TEMPS IN THE UPR MS VALLEY/GREAT LKS TO UNSEASONABLY HI
LVLS...WITH 12Z H85 TEMPS AT INL/MPX UP TO 7C VS 0C AT APX AND 3C AT
GRB TOWARD THE RETREATING COLD AIR. LO CLDS OVER THE E HALF OF THE
CWA THAT FORMED AS THIS WARMER AIR PUSHED OVER MORE RESILIENT NEAR
SFC COLD AIR IN THE PRESENCE OF RADIATIONAL COOLING LAST NGT ARE
ONLY GRDLY DISSIPATING EARLY THIS AFTN. OTRW...THE OVERALL DRYNESS
OF THE LOCAL 12Z RAOBS IS ALLOWING A MOSUNNY DAY. BUT MORE LO CLDS
ARE PUSHING NEWD THRU IOWA TOWARD THE UPR MIDWEST IN THE SW LLVL
FLOW ARND THE HI IN THE MID ATLANTIC. A DISTURBANCE IN THE SRN
BRANCH FLOW IS NOW IN KANSAS AND MOVING NEWD AS WELL.
&&
.SHORT TERM DISCUSSION /TNGT AND MON/...
MAIN FCST CONCERNS THIS PACKAGE ARE LO CLD TRENDS AND THE POTENTIAL
FOR MIXED PCPN ON MON AS DISTURBANCE NOW IN KANSAS RIDES TO THE NE.
TNGT...EXPECT THE LINGERING LO CLDS OVER THE E TO BE GONE BY FCST
ISSUANCE...WITH MOCLR SKIES/WELL ABV NORMAL TEMPS DOMINATING.
ALTHOUGH THE LO CLDS HEADING NE FM IOWA ARE LIKELY TO MIX OUT WITH
DAYTIME TEMPS RISING INTO THE 30S/40S THIS AFTN...EXPECT THE ST/SC
TO REDVLP WITH LOSS OF DAYTIME HEATING AFT SUNSET. 12Z MODEL
GUIDANCE SHOWS THE HIER LLVL RH ARRIVING NEAR THE WI BORDER W OF IMT
THIS EVNG...SO EXPECT EXPANDING LO CLDS SW-NE. THE COMBINATION OF
THE LO CLDS/STEADY SW FLOW OF MILD AIR WL GREATLY REDUCE DIURNAL
FALL OF TEMPS...BUT MIN TEMPS WL STILL FALL BLO 32 EVERYWHERE.
LOCATIONS NEAR LK SUP WHERE THE SW FLOW DOWNSLOPES WL BE WARMEST.
OPTED TO RETAIN MENTION OF SOME -FZDZ OVER THE INTERIOR W LATE AWAY
FM THE DOWNSLOPING NEAR LK SUP AS SHALLOW MSTR INFLUX GROWS A BIT
DEEPER WITH SOME DPVA/OMEGA/DEEPER MSTR ADVCTN AHEAD OF APRCHG
KANSAS SHRTWV. BUT SINCE THE HIER RH WL REMAIN WELL BLO THE DGZ AND
STILL BE RELATIVELY SHALLOW /BLO ABOUT H85/...ANY PCPN SHOULD REMAIN
IN THE FORM OF SMALL WATER DROPLETS.
MON...COMBINATION OF ARRIVAL OF LO PRES TROF ATTENDANT TO SHRTWV/SFC
LO NOW IN NW ONTARIO...DEEPER MSTR FM THE SW...AND SHRTWV NOW IN
KANSAS/ACCOMPANYING DYNAMICS WL RESULT IN EXPANDING PCPN CHCS. THE
12Z NAM/GFS/LOCAL WRF-ARW RUNS ALL EXHIBIT THE HIEST QPF UP TO ARND
0.20 INCH OVER THE SE CWA...WHERE GFS SHOWS AN AXIS OF SHARPER H85-7
FGEN AND THE ALL MODELS INDICATE DEEPER MSTR/OMEGA EXTENDING THRU
THE DGZ. SO OPTED TO RETAIN GOING LIKELY POPS IN THIS AREA. PTYPE WL
BE A SGNFT CONCERN. SUSPECT ONLY -FZDZ/FLURRIES WL BE ARND EARLY
WITH RELATIVELY SHALLOW MSTR YET...BUT EITHER RA...SN...OR A MIX IS
MORE LIKELY BY THE AFTN AT LEAST OVER OVER THE SE HALF WITH DEEPER
MSTR/LARGER PCPN PARTICLES. FOR THE PAST SEVERAL RUNS...THE NAM HAS
BEEN WARMEST WITH LLVL TEMPS AND THUS INDICATES RA WL BE THE
PREDOMINANT PTYPE AT LEAST OVER THE SE. THE 12Z CNDN MODEL SUPPORTS
THIS WARMER RUN AS WELL. ALTHOUGH THE UNSEASONABLE WARMTH TDAY WOULD
SUG THESE MODELS ARE ON THE RIGHT TRACK...RELATIVELY DRY NATURE OF
THE AIRMASS/POTENTIAL FOR EVAP COOLING HINTS THE COOLER GFS/WRF-ARW/
09Z SREF ARE ON THE RIGHT TRACK. BLENDED IN THAT DIRECTION FOR LLVL
TEMPS FIELDS FOR NOW TO DETERMINE PTYES.
.LONG TERM /00Z TUESDAY THROUGH NEXT SUNDAY/...
MAIN FOCUS FOR THE EXTENDED IS WITH PTYPES AND CHANCES FOR FREEZING
PRECIP FROM MON NIGHT THROUGH WED MORNING...THEN WITH A SYSTEM
MOVING THROUGH WED NIGHT/THU.
A SFC TROUGH/FRONT WILL BE STALLED OVER UPPER MI FROM THE CENTRAL
PLAINS FROM THE START OF THE PERIOD MON NIGHT...THROUGH TUE. A WEAK
UPPER WAVE WILL BE MOVING THROUGH THE ERN CWA PRIOR TO 06Z
TUE...PRODUCING SOME RAIN EAST. THE HARDEST PART OF THIS FORECAST
PERIOD IS THAT SHALLOW MOISTURE WILL EXIST ALONG AND SOUTH OF THE
FRONT...WITH DRY MID LEVELS KEEPING ICE CRYSTALS FROM FORMING. THE
TEMP PROFILE WILL BE SUB-FREEZING THROUGH WEDNESDAY MORNING /EXCEPT
NEAR SFC TEMPS DURING THE DAY TUE/...WHICH WILL KEEP PRECIP WITH THE
DEEPER MOISTURE AND LIFT OVER THE EAST MON NIGHT AS SNOW...AND
DRIZZLE/FREEZING DRIZZLE DIFFERENTIATION ELSEWHERE WILL BE DEPENDENT
ON SFC TEMPS. AT THIS POINT...IT LOOKS LIKE THERE IS POTENTIAL FOR
UP TO A TENTH OF AN INCH OF ICE ACCUMULATION FROM 00Z TUE INTO TUE
MORNING...MAINLY OVER THE WEST HALF OF UPPER MI. SOME UNCERTAINTY
STILL EXISTS WITH HOW MUCH FREEZING DRIZZLE WILL FALL...AND WHERE
THE HEAVIEST AMOUNTS WILL BE.
ATTENTION THEN TURNS TO THE NEXT SYSTEM MOVING IN AS AN UPPER TROUGH
FROM CENTRAL CANADA EXTENDS OVER THE PLAINS AT 00Z THU...MOVES
ACROSS UPPER MI THU...THEN INTO QUEBEC FRI NIGHT. MODELS SEEM TO BE
COMING INTO BETTER AGREEMENT WITH THIS SYSTEM BUT THERE ARE STILL
SOME BIG DIFFERENCES BETWEEN THEM...AND THOSE DIFFERENCES PLAY A
HUGE ROLE IN THE FORECAST. THE GEM AND NAM LOOK ANOMALOUS WITH THE
SYSTEM...SO THEY WERE NOT USED. THE 11/00Z ECMWF...WHICH HAS SHOWN
BETTER RUN TO RUN CONTINUITY THAN THE GFS...HAS A DEEPER UPPER WAVE
CO-LOCATED WITH THE CLOSED SFC LOW THAN THE GFS. THE MAIN DIFFERENCE
BETWEEN THE MODEL STEMS FROM THE STRENGTH OF THE UPPER TROUGH MOVING
IN...WHICH LEADS TO /AMONG OTHER THINGS/ TIMING DIFFERENCES IN THE
LOW LEVELS. THE 11/12Z GFS BRINGS THE SFC LOW INTO THE CWA AROUND
06Z THU...WHILE THE 11/00Z ECMWF LAGS UNTIL AROUND 15Z THU. BOTH
MODELS BRING IN MID LEVEL TEMPS THAT WOULD LEAD TO LIQUID PRECIP
UNTIL THE LOW PASSES AND COLDER AIR COMES IN. SFC TEMPS WED NIGHT
WILL FALL TO AROUND 30F OVER THE WEST HALF OF UPPER MI...BUT SHOULD
STAY NEAR OR ABOVE FREEZING OVER THE EAST HALF. TEMPS OVER THE W
LOOK TO STAY NEAR OR ABOVE FREEZING THROUGH AROUND 03Z THU...AND
STAY THERE UNTIL MID TO LATE MORNING THU. THE GFS BRING THE BULK OF
THE SYNOPTIC QPF /EASILY GREATER THAN 0.25 INCHES IN SOME SPOTS FROM
BOTH THE ECMWF AND GFS/ BETWEEN 00Z AND 12Z THU...WHILE THE ECMWF IS
BETWEEN 12Z AND 18Z THU...SO REGARDLESS OF MODEL THERE IS POTENTIAL
FOR SIGNIFICANT FREEZING RAIN IF ALL THE INGREDIENTS COME TOGETHER.
IT NEEDS TO BE STRESSED AGAIN THAT THERE IS STILL A CONSIDERABLE
AMOUNT OF UNCERTAINTY WITH THIS SYSTEM...ESPECIALLY WITH THE SMALL
SCALE DETAILS NEEDED FOR FREEZING RAIN. DUE TO THE POTENTIAL FOR
SIGNIFICANT FREEZING RAIN ACCUMULATIONS...PAY EXTRA ATTENTION AND
KEEP UP TO DATE WITH LATER FORECASTS ON THIS SYSTEM.
MODELS ARE IN DECENT GENERAL AGREEMENT FROM FRI THROUGH SUN. NW
WINDS AND 850MB TEMPS FALLING TO AOB -12C BY AT LEAST 12Z FRI WILL
MAKE FOR POTENTIAL FOR LES...BUT DRY AIR IS ALSO MOVING IN. A SFC
RIDGE WILL MOVE THROUGH SAT AFTERNOON AND EAST BY LATE
SAT...BRINGING SWLY WINDS. SW FLOW BEHIND THE DEPARTING HIGH E AND
LOW PRESSURE W...ALONG WITH AN UPPER RIDGE BUILDING IN FROM THE
W...WILL LEAD TO 850MB TEMPS INCREASING TO AOA 0C BY LATE SUNDAY.
&&
.AVIATION /FOR THE 06Z TAF ISSUANCE/...
LOW MVFR CIGS CONTINUE TO SPREAD ACROSS THE REGION THIS MORNING AND
WILL GRADUALLY LOWER TO IFR AT ALL THREE TAF SITES BY 10Z. CLOUD
PRODUCING LAYER IS QUITE SHALLOW SO DEVELOPMENT OF -DZ/FZDZ WILL BE
DELAYED UNTIL SOME DEEPER MOISTURE ARRIVES CLOSER TO 12Z. NOT
CONFIDENT ON THE DEVELOPMENT OF -FZDZ AS SFC TEMPERATURE TRENDS
WARMER THAN BUFKIT SOUNDINGS BY A FEW DEGREES. ONCE TROUGH SWINGS
THOUGH THE AREA EXPECT BETTER LIFT/FORCING TO PRODUCE LIGHT SNOW
DURING THE DAYTIME HOURS. KSAW TO HAVE A LITTLE WARMER TEMPERATURE
PROFILE AND SHOULD SEE -RASN IN THE AFTERNOON. AREAS OF SNOW
EXPECTED OVER ALL THREE SITES BY 0Z TUESDAY AS COLDER AIR FILTERS IN.
&&
.MARINE /FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE/...
EXPECT SW WINDS UP TO 30 KTS LATE THIS AFTN TO DIMINISH TONIGHT WITH
THE APPROACH OF A LO PRES TROF AND WEAKER PRES GRADIENT. ALTHOUGH
THERE WILL BE A WSHFT TO THE N FOLLOWING THE PASSAGE OF THIS TROF ON
MON...RELATIVELY LIGHT WINDS UNDER 20 KTS WILL PERSIST INTO WED BUT
SLOWLY VEER TO THE S AS A LO PRES SYSTEM DEVELOPING IN THE PLAINS
BEGINS TO MOVE NE TOWARD THE UPPER GREAT LKS. SE WINDS AHEAD OF THIS
LO MAY INCREASE TO 25 KTS ESPECIALLY OVER THE E HALF. THE MAIN
HAZARD WILL BE AFTER THE LO MOVES TO THE NE ON THU...WHEN NW GALES
IN ITS WAKE ENHANCED BY THE ARRIVAL OF VERY COLD AIR/MIXING WILL
PREVAIL. EXPECT THESE STRONG WINDS TO DIMINISH ON FRI WITH THE SLOW
APPROACH OF HI PRES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...KC
SHORT TERM...KC
LONG TERM...TITUS
AVIATION...RJT
MARINE...KC
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
402 AM CST MON DEC 12 2011
.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
PRIMARY FORECAST CHALLENGE WILL BE CLOUD COVER AND CORRESPONDING
TEMPERATURES. GFS/NAM/ECMWF/GEM MASS/THERMAL FIELDS ARE IN GOOD
AGREEMENT...BUT ONLY THE RUC AND HRRR BEST RESEMBLE CURRENT CLOUD
TRENDS. WILL FOLLOW HIGH RESOLUTION MODELS FOR THE NEAR TERM...
TRANSITIONING TO A MODEL BLEND THEREAFTER.
09 UTC SURFACE ANALYSIS SHOWS A WEAK TROUGH EXTENDING FROM SOUTH
CENTRAL SD INTO THE MN ARROWHEAD WITH LOW STRATUS ALONG AND
SOUTHEAST OF THE TROUGH AXIS. A SECOND AREA OF LOW CLOUDS IS
TRAPPED BENEATH CANADIAN HIGH PRESSURE AND EXTENDS ALONG AND
NORTHWEST OF A LINE FROM HALLOCK TO DEVILS LAKE TO BISMARCK.
BETWEEN THESE CLOUDS SKIES ARE CLEAR...BUT THE TWO CLOUD DECKS
ARE CRAWLING TOWARD EACH OTHER. RUC/HRRR SUGGEST DRY LOW-LEVEL
NORTHEAST FLOW WILL KEEP SOUTHEAST ND INTO NORTH CENTRAL MN CLOUD
FREE THROUGH AT LEAST EARLY MORNING...BUT MAY BEGIN TO FILL IN
THEREAFTER. AS A RESULT...AREAS NOT IN THE NORTHWEST OR SOUTHEAST
FORECAST AREA WILL START THE DAY SUNNY WITH A GRADUAL INCREASE IN
CLOUDS...POSSIBLY BECOMING MOSTLY CLOUDY BY LATE THIS AFTERNOON.
WILL KEEP FORECAST DRY TODAY...BUT SOME LIGHT DRIZZLE IS POSSIBLE
GIVEN VERY DRY AIR ATOP NEAR SURFACE SATURATED LAYER. AS CLOUD COVER
EXPANDS...DO NOT EXPECT MUCH MOVEMENT IN TEMPERATURES WITH A
GENERAL GRADIENT FROM THE UPPER TEENS ACROSS PORTIONS OF THE
DEVILS LAKE BASIN TO THE UPPER 20S TO NEAR 30 DEGREES ACROSS WEST
CENTRAL MN. LIGHT NORTHEAST WIND WILL BE THE RULE THROUGH THE DAY.
TUESDAY WILL BE DRY AND SLIGHTLY WARMER AS SURFACE HIGH PRESSURE
AXIS DRIFTS ACROSS THE FORECAST AREA AND LIGHT RETURN FLOW DEVELOPS.
HIGHS WILL RANGE FROM THE MID 20S TO LOWER 30S.
DID NOT CHANGE POPS MUCH WEDNESDAY AND WEDNESDAY NIGHT...KEEPING
CHANCES FOR SNOW ALONG AND EAST OF A LINE FROM LISBON TO FARGO TO
BAUDETTE. MODELS ARE NOW IN GOOD AGREEMENT SHOWING A NORTHERN STREAM
SHORT-WAVE KICK MORE POTENT ENERGY FROM SOUTHWEST CONUS CUT-OFF
LOW FARTHER SOUTH AND EAST ACROSS IA AND WI. ACCUMULATIONS...IF
ANY...SHOULD BE MINIMAL. TEMPERATURES WEDNESDAY WILL RISE INTO THE
UPPER 20S TO LOWER 30S BEFORE COOLING OFF THE LATTER HALF OF THE
WEEK.
.LONG TERM...THURSDAY THROUGH SUNDAY NIGHT
THE MAIN CHALLENGE WILL CONTINUE TO BE TEMPS WITH NO STORMS IN
SIGHT. A COLD FRONT WILL USHER IN MUCH COLDER AIR ON THURSDAY ALONG
WITH BRISK/BREEZY CONDITIONS. TEMPS WILL MODERATE ABOVE NORMAL
BY NEXT WEEKEND WITH UPPER RIDGE BUILDING AND 850MB TEMPS CLIMBING
OVER 0C ONCE AGAIN.
&&
.AVIATION...
HIGH DEGREE OF UNCERTAINTY CONCERNING CEILING FORECAST TODAY AS
THE REGION IS SANDWICHED BY IFR/LOW MVFR CLOUDS TO THE NORTHWEST
AND SOUTHEAST. KDVL AND KBJI ARE CLOUDY WITH CLEARING JUST TO
THEIR SOUTHEAST AND NORTHWEST RESPECTIVELY. IFR/MVFR CEILINGS
LIKELY TO IMPACT THESE TWO AIRFIELDS FOR MUCH OF THE DAY. DUE TO
DRY NORTHEAST LOW-LEVEL FLOW...DIFFICULT TO KNOW THE EXTENT TO
WHICH CLOUDS MAY IMPACT VALLEY TAF SITES. KGFK...KFAR AND KTVF
SHOULD STAY CLOUD-FREE THROUGH AT LEAST 12 UTC...WITH LOW CLOUDS
POSSIBLY IMPACTING AIRFIELDS LATER THIS MORNING OR EARLY AFTERNOON.
WILL UPDATE TAFS AS GREATER CERTAINTY IS REALIZED.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
ROGERS/DK
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
356 AM EST MON DEC 12 2011
.SYNOPSIS...
HIGH PRESSURE WILL DOMINATE THE REGIONS WEATHER INTO TUESDAY. THE
HIGH WILL MOVE EAST TUESDAY NIGHT AS A WARM FRONT APPROACHES THE
AREA FROM THE SOUTHWEST. THE WARM FRONT WILL PUSH ACROSS THE
REGION ON WEDNESDAY...FOLLOWED BY A COLD FRONT WEDNESDAY NIGHT
INTO THURSDAY. TEMPERATURES WILL WARM TO ABOVE NORMAL READINGS
THROUGH THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SURFACE HIGH PRESSURE EXTENDED FROM THE NEW ENGLAND COAST
TO THE THE OHIO AND TENNESSEE VALLEYS THIS MORNING. THE HIGH IS
EXPECTED TO MOVE LITTLE TODAY. AFTER A COLD START...TEMPERATURES
ARE EXPECTED TO MODERATE UNDER ABUNDANT SUNSHINE. HIGHS WILL RANGE
FROM THE LOWER 40S NORTH TO THE UPPER 40S SOUTH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
SURFACE HIGH PRESSURE WILL REESTABLISH ITSELF OVER THE OHIO VALLEY
TONIGHT INTO TUESDAY. MEANWHILE...WEAK UPR LVL ENERGY WILL TRACK
ACROSS THE GREAT LAKES. RETURN LOW LEVEL FLOW MAY BRING SOME LOWER
CLOUDS TO OUR SE CWFA THIS EVENING/OVERNIGHT WHILE MID LVL
MOISTURE STREAMS IN FROM THE WEST. CLOUD COVER WILL PREVENT
TEMPERATURES FROM COOLING OFF TOO MUCH AND SHOULD RANGE FROM THE
MID 20S TO THE LOWER 30S. SKIES ON TUESDAY WILL RANGE FROM
PARTLY TO MOSTLY CLOUDY AS MID LVL MOISTURE CONTINUES TO ADVECT
ACROSS THE REGION FROM THE WEST. HIGHS WILL VARY FROM THE MID 40S
NORTH TO NEAR 50 SOUTH.
MODELS ARE IN GOOD AGREEMENT FOR TUESDAY NIGHT INTO WEDNESDAY.
SURFACE HIGH WILL MOVE EAST AS A WARM FRONT DEVELOPS TO OUR
SOUTHWEST. THE WARM FRONT WILL MOVE ACROSS THE AREA ON WEDNESDAY.
DEEP MOISTURE WILL INCREASE OVER THE REGION THROUGH THE PERIOD.
THIS MOISTURE WILL COINCIDE WITH A STRONG LOW LEVEL JET AND UPR
LVL DIVERGENCE FROM THE RR QUAD OF AN UPR LVL JET. THIS WILL
RESULT IN SHOWERS WITH THE HIGHEST THREAT POISED FOR THE NRN
ZONES. HAVE RAISED POPS TO CATEGORICAL ACRS NRN AREAS TUESDAY
NIGHT INTO WEDNESDAY. PCPN CHANCES WILL DIMINISH TO LOW CHANCE
SOUTH OF THE OHIO RIVER.
THE WARM FRONT WILL LIFT NORTH OF THE AREA WEDNESDAY NIGHT. THE
WARM FRONT WILL BE FOLLOWED BY A COLD FRONT WHICH WILL PUSH
SOUTHEAST ACROSS THE REGION ON THURSDAY. DEEP MOISTURE COUPLED
WITH DECENT LOW LEVEL FORCING AHEAD OF THE FRONT WILL BRING
ANOTHER ROUND OF SHOWERS. HAVE GONE WITH CATEGORICAL POPS. THE
FRONT WILL PUSH SOUTHEAST THURSDAY NIGHT AS HIGH PRESSURE BUILDS
INTO THE WESTERN GREAT LAKES. THIS WILL BRING AN END TO THE PCPN.
TEMPERATURES TUESDAY NIGHT INTO THURSDAY NIGHT WILL EXHIBIT NON
DIURNAL TRENDS AND HAVE RELIED ON A BLEND OF RAW 2 M GFS AND ECMWF
FOR THE MOST PART.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
HIGH PRESSURE WILL BUILD INTO THE AREA FOR THE WEEKEND. A WEAK
SHORT WAVE MAY DROP DOWN ACROSS THE GREAT LAKES ON SATURDAY...BUT
IT LOOKS LIKE BETTER FORCING WITH THIS WILL REMAIN OFF TO OUR
NORTH SO WILL THEREFORE MAINTAIN A DRY FORECAST THROUGH THE
REMAINDER OF THE LONG TERM PERIOD. COOLER AIR WILL FILTER IN
BEHIND THE FRONT LATE IN THE WEEK...LEADING TO A RETURN TO MORE
SEASONABLE TEMPERATURES THROUGH THE WEEKEND.
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
HIGH PRESSURE WILL MEANDER OVER THE UPPER OHIO VALLEY REGION
THROUGH THE NEXT DAY OR SO. THIS WILL BRING LIGHT TO CALM WINDS
(OCCASIONALLY UP TO AROUND 5 KNOTS OUT OF THE SOUTH). SOME CIRRUS
WILL SPILL INTO THE REGION TODAY...BUT NO LOW CLOUDS ARE EXPECTED
AT THIS TIME.
OUTLOOK...NO SIGNIFICANT WEATHER EXPECTED.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HICKMAN
NEAR TERM...HICKMAN
SHORT TERM...HICKMAN
LONG TERM...HICKMAN/JGL
AVIATION...HATZOS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
331 AM CST MON DEC 12 2011
.SHORT TERM...TODAY THROUGH WEDNESDAY
331 AM CST MON DEC 12 2011
FORECAST CONCERNS ARE ON DRIZZLE/FREEZING DRIZZLE THIS MORNING AND
AGAIN TONIGHT AND THE POTENTIAL FOR AREAS OF FOG LATE TONIGHT INTO
TUESDAY MORNING. FOCUS THEN TURNS TO STORM SYSTEM EXPECTED TO
IMPACT THE AREA TUESDAY NIGHT INTO WEDNESDAY...WITH PRECIPITATION
TYPE CONCERNS.
CURRENT RADAR AND SURFACE OBSERVATIONS SHOWED DRIZZLE FALLING
ACROSS MUCH OF THE FORECAST AREA. AREAS OF FREEZING DRIZZLE HAVE
BEEN REPORTED ACROSS NORTH CENTRAL WISCONSIN THROUGH SOUTHWEST
WISCONSIN...WITH SOME SECONDARY ROADWAYS VERY SLICK.
DRIZZLE WILL CONTINUE ACROSS THE AREA THIS MORNING AS LOW LEVEL
MOISTURE CONTINUES TO STREAM INTO THE REGION FROM THE SOUTHERN
PLAINS. ISENTROPIC LIFT ON THE 280-300K SURFACE ALONG WITH A WEAK
SHORTWAVE TROUGH MOVING ACROSS THE REGION...WILL ACT TO PRODUCE
DRIZZLE ACROSS MUCH OF THE FORECAST AREA THROUGH THIS AFTERNOON.
SURFACE TEMPERATURES HAVE WARMED ABOVE FREEZING ACROSS MUCH OF THE
FORECAST AREA EARLY THIS MORNING. HOWEVER...SOME SECONDARY ROADWAYS
AND SHADED LOCATIONS WILL LIKELY HAVE SURFACE TEMPERATURES AROUND
FREEZING AND SHOULD EXPERIENCE SOME LIGHT ICING. WILL CONTINUE THE
FREEZING DRIZZLE ADVISORY THROUGH 9 AM FOR THIS LIGHT ICING
POTENTIAL. DRIZZLE AND CLOUDY SKIES CAN BE EXPECTED INTO THIS
EVENING...WITH THE DRIZZLE GRADUALLY TAPERING OFF DURING THE LATE
EVENING INTO THE OVERNIGHT HOURS. SOME PATCHY FREEZING DRIZZLE CAN
BE EXPECTED ACROSS WESTERN AND CENTRAL WISCONSIN...WHERE A FEW
LOCATIONS WILL DROP TO FREEZING. AT THIS TIME IT APPEARS ICING WILL
BE MINIMAL BUT WILL HAVE TO CLOSELY MONITOR TEMPERATURES THROUGH THE
DAY TODAY. IF TEMPERATURES COOL FURTHER THAN WHAT IS CURRENTLY
ANTICIPATED...A FREEZING RAIN ADVISORY MAY BE NEEDED THIS EVENING
INTO TONIGHT...ESPECIALLY ALONG AND NORTH OF THE I-94 CORRIDOR. LOOK
FOR LOW TEMPERATURES TO FALL INTO THE LOWER 30S TONIGHT UNDER CLOUDY
SKIES.
LOW LEVEL MOISTURE WILL REMAIN IN PLACE ACROSS THE AREA ON TUESDAY
WITH WEAK RIDGING ALOFT MOVING OVERHEAD. WITH LIGHT AND VARIABLE
WINDS ACROSS THE REGION AND ANY REMAINING SNOW MELTING...AREAS OF
FOG MAY DEVELOP AND COULD POTENTIALLY BE DENSE EARLY TUESDAY MORNING.
HAVE ADDED AREAS OF FOG TO THE FORECAST LATE MONDAY NIGHT THROUGH
MID MORNING TUESDAY. STRATUS LOOKS TO PERSIST ACROSS MUCH OF THE
FORECAST AREA WITH MOSTLY CLOUDY SKIES EXPECTED. ANY VERTICAL MOTION
MOVING ACROSS THE REGION COULD TRIGGER SOME LIGHT DRIZZLE.
TEMPERATURES SHOULD BE ABOVE FREEZING ON TUESDAY...WITH HIGHS IN THE
MID 30S TO AROUND 40 SO ICING SHOULD NOT BE A CONCERN.
AN UPPER LEVEL TROUGH IS EXPECTED TO MOVE FROM THE SOUTHWEST CONUS
INTO THE CENTRAL PLAINS LATE TUESDAY NIGHT. WARM AIR ADVECTION ALOFT
WILL SPREAD ACROSS THE REGION...WITH RAIN AND SNOW DEVELOPING ACROSS
MUCH OF THE FORECAST AREA. AT THIS TIME FORECAST SOUNDINGS APPEAR
WARM ENOUGH FOR THE PRECIPITATION TO FALL AS RAIN. TEMPERATURES LOOK
TO FALL INTO THE 33 TO 36 DEGREE RANGE LATE TUESDAY EVENING THEN
GRADUALLY WARM AFTER MIDNIGHT. WILL HAVE TO CLOSELY MONITOR THE NEXT
FEW MODEL RUNS...IF TEMPERATURES DO NOT WARM AS ANTICIPATED A BRIEF
PERIOD OF FREEZING RAIN MAY DEVELOP LATE TUESDAY NIGHT. HAVE KEPT
PRECIPITATION TYPES AS RAIN/SNOW TUESDAY NIGHT GIVEN THE EXPECTED
TEMPERATURES. FORECAST SOUNDINGS ARE SHOWING SOME ELEVATED CAPE
ACROSS MUCH OF THE FORECAST AREA...WITH AROUND 150 J/KG LIFTING
FROM 730 MB. IF THE ELEVATED CAPE CONTINUES IN THE NEXT SET OF
MODEL RUNS...ISOLATED THUNDER MAY NEED TO BE ADDED TO THE FORECAST
LATE TUESDAY NIGHT INTO EARLY WEDNESDAY MORNING.
12.00 GFS AND ECMWF ARE IN REASONABLE AGREEMENT ON WEDNESDAY SHOWING
RAIN PERSISTING THROUGH THE DAY ACROSS THE FORECAST AREA AS THE
UPPER LEVEL TROUGH MOVES FROM THE CENTRAL PLAINS INTO THE UPPER
MISSISSIPPI RIVER VALLEY. THE NAM KEEPS THE BULK OF THE PRECIPITATION
ACROSS SOUTHEAST IOWA THROUGH NORTHERN ILLINOIS. HAVE LEANED MORE
TOWARD THE GFS AND ECMWF SOLUTION. FELT THE GFS WAS A BIT OVERDONE
ACROSS SOUTHEAST MINNESOTA INTO NORTHWEST WISCONSIN...PAINTING MUCH
HEAVIER PRECIPITATION ACROSS THE AREA WITH A DEEPER SURFACE LOW OVER
THE OTHER MODELS. A COLD FRONT IS EXPECTED TO MOVE ACROSS THE
FORECAST AREA LATE WEDNESDAY NIGHT INTO EARLY THURSDAY MORNING WITH
TEMPERATURES FALLING. RAIN SHOULD GRADUALLY CHANGE OVER TO SNOW FROM
NORTHWEST TO SOUTHEAST AS COOLER AIR FILTERS INTO THE AREA. LIGHT
SNOW ACCUMULATION IS POSSIBLE...BUT EXACTLY HOW MUCH WILL FALL WILL
DEPEND ON THE TRACK OF THE LOW AND WHEN THE COOLER AIR WRAPS INTO
THE REGION. LOOK FOR LOW TEMPERATURES TO OCCUR LATE IN THE
NIGHT...WITH TEMPS FALLING INTO THE UPPER 20S ACROSS SOUTHEAST
MINNESOTA THOUGH NORTH CENTRAL WISCONSIN TO THE MID 30S ACROSS FAR
SOUTHWEST WISCONSIN.
.LONG TERM...THURSDAY THROUGH SUNDAY
331 AM CST MON DEC 12 2011
MUCH COLDER AIR WILL PUSH INTO THE AREA ON THURSDAY IN THE WAKE OF A
COLD FRONT...WITH 850 MB TEMPERATURES FALLING FROM 1 C EARLY
THURSDAY MORNING...TO -8 C BY EARLY THURSDAY EVENING. LOOK FOR
TEMPERATURES TO FALL THROUGH THE DAY...WITH READINGS IN THE MID
20S BY LATE THURSDAY AFTERNOON. SOME LIGHT SNOW MAY LINGER ACROSS
THE AREA ON THURSDAY BUT SHOULD QUICKLY TAPER OFF INTO THE
AFTERNOON AS COLD HIGH PRESSURE STARTS TO BUILD IN. LOOK FOR LOWS
TO FALL INTO THE TEENS THURSDAY NIGHT. THE HIGH IS EXPECTED TO
REMAIN OVER THE AREA INTO THE WEEKEND WITH COOL AND QUIET WEATHER
ANTICIPATED. HIGHS WILL BE MAINLY IN THE 20S WITH LOWS IN THE
TEENS. MODELS ARE SHOWING A WARM UP FOR SUNDAY WITH HIGHS CLIMBING
BACK INTO THE MID TO UPPER 30S.
&&
.AVIATION...THROUGH 06Z TUESDAY
1135 PM CST SUN DEC 11 2011
CEILINGS HAVE ACTUALLY LIFTED ACROSS THE AREA THIS EVENING AND
WILL START THE TAFS OUT WITH EITHER MVFR OR VFR CEILINGS BUT WITH
MVFR VISIBILITIES FROM SOME LIGHT FOG. STILL EXPECTING CONDITIONS
TO DETERIORATE LATER TONIGHT AS THE SHORT WAVE TROUGH APPROACHES
AND INCREASES THE LIFT. THE 12.03Z RUC AND 12.00Z NAM NOW SUGGESTS
THE LOWER CEILINGS...VISIBILITY AND DRIZZLE WILL BE SLOWER TO
ARRIVE AND PUSHED THIS BACK TO AROUND 10Z BUT THERE ARE SOME
INDICATIONS IT COULD EVEN HOLD OFF LONGER. TEMPERATURES STILL TO
BE WARM ENOUGH TO KEEP THE PRECIPITATION AS DRIZZLE WITH LITTLE
THREAT FOR ANY FREEZING DRIZZLE AT THE TAF SITES. THE DRIZZLE
SHOULD BEGIN TO TAPER OFF DURING THE AFTERNOON AND HAVE PUSHED
BOTH THE VISIBILITY AND CEILING UP A LITTLE AS THIS OCCURS. THE
LOW LEVEL MOISTURE DOES NOT GET CLEANED OUT OF THE AREA WITH THE
FLOW REMAINING OUT OF THE SOUTH OR SOUTHWEST THROUGH 06Z MONDAY SO
VERY POSSIBLE THAT THE CEILINGS WILL START TO GO DOWN AGAIN MONDAY
EVENING WITH SOME COOLING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
331 AM CST MON DEC 12 2011
WI...FREEZING RAIN ADVISORY UNTIL 9 AM CST THIS MORNING FOR WIZ017-
029-034-042>044-053>055-061.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM....WETENKAMP
AVIATION.....04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1135 PM CST SUN DEC 11 2011
.SHORT TERM...TONIGHT THROUGH WEDNESDAY
250 PM CST SUN DEC 11 2011
AMPLE CHALLENGES TO THE FORECAST FOR THE NEXT FEW DAYS...WITH THE
FOCUS ON THE PCPN TYPE.
TONIGHT AND MONDAY NOT LOOKING AS CLEAR-CUT AS THE PAST FEW DAYS
SUGGESTED IT WOULD BE...WITH FREEZING DRIZZLE TO DRIZZLE AND BACK
OVER TO FREEZING DRIZZLE. PCPN WILL OCCUR FOR THE REGION...BUT WHAT
FALLS IS MORE HAZY NOW.
LATEST FOG/STRATUS SATELLITE IMAGERY INDICATES AN EXPANSIVE AREA OF
STRATUS MOVING NORTHEAST ACROSS THE PLAINS...SURGING ACROSS THE
LOCAL AREA. THIS WAS IN RESPONSE TO A WARM/MOIST PUSH OF LOW LEVEL
AIR RIDING ACROSS A SNOW PACK. DESPITE WINDS OF 10 KTS OR
GREATER...VSBYS WITH THE STRATUS ARE 2-4 MILES...BRINGING AN ASPECT
OF ADVECTION FOG TO THE FORECAST.
THE FAVORABLE LOW LEVEL MOISTURE TRANSPORT/WARM AIR ADVECTION NOSES
ACROSS THE FORECAST AREA TONIGHT...PERSISTING THROUGH MUCH OF
MONDAY. THIS IS ASSOCIATED WITH AN UPPER LEVEL SHORTWAVE THAT WILL
SPIN FROM THE CENTRAL PLAINS TO ACROSS THE UPPER MISSISSIPPI RIVER
VALLEY BY 18Z MON. THE SATURATION IS ALL IN THE LOW LEVELS
THOUGH...AS EVIDENCED BY TIME/HEIGHT X-SECTIONS AND BUFKIT
SOUNDINGS. AS SUCH...THE DEPTH OF THE SATURATION AND TEMPS AT THE
TOP OF THE ANTICIPATED CLOUD LAYER WILL HAVE AN IMPACT ON THE PCPN
TYPE. PREVIOUS MODEL RUNS POINTED TO NO ICE IN THE CLOUD...THUS
LIQUID AND LIKELY DRIZZLE. HOWEVER...INDICATIONS NOW ARE THAT -10 TO
-12 C COULD BE REALIZED IN CLOUD TOPS...MAKING ICE MORE LIKELY AND
POTENTIALLY SNOW IF THE REST OF THE THERMAL PROFILE WOULD SUPPORT
IT. IN ADDITION...THE SATURATION COULD BECOME DEEP ENOUGH FOR A
PERIOD ON SAT WHERE RAIN WOULD BE MORE LIKELY RATHER THAN DRIZZLE.
ACCUMULATION WOULD STILL BE MINOR...AND BELIEVE DRIZZLE WILL BE THE
MORE PREDOMINANT LIQUID TYPE...SO WILL STAY WITH DRIZZLE FOR NOW.
ANOTHER QUESTION THAT HAS BECOME PROBLEMATIC ARE SFC TEMPS.
PREVIOUSLY FREEZING TEMPERATURES OVERNIGHT/MONDAY MORNING LOOKED
LIKE A SURE THING FOR THE ENTIRE FORECAST AREA. LATEST MODELS RUNS
BRING THIS INTO QUESTION. THE LOW LEVEL WARM AIR ADVECTION WILL NOT
ONLY GO INTO CLOUD/PCPN PRODUCTION LATE TONIGHT...BUT IT SHOULD ALSO
SERVE TO HELP STEADY...OR EVEN RISE...TEMPERATURES OVERNIGHT. IF
THIS OCCURS...WESTERN PARTS OF THE FORECAST AREA HAVE A
PRETTY GOOD CHANCE OF STAYING ABOVE FREEZING. LATEST RUC13 TEMPS AND
LAMP GUIDANCE SUPPORTS THIS...AND HAVE TAILORED TEMPS TONIGHT THIS
WAY. AS A RESULT...THE WESTERN 1/2 OF THE FORECAST AREA WILL LIKELY
MISS OUT ON ANY FREEZING DRIZZLE. FARTHER EAST THOUGH TEMPS HAVE A
MUCH BETTER CHANCE TO COOL TO FREEZING...AND THUS AN ICING THREAT
WHEN THE DRIZZLE MOVES IN. WILL GO WITH A FREEZING RAIN ADV FOR THE
COUNTIES IN THE EAST...ESPECIALLY IN THE I-94 CORRIDOR...FROM 09-15Z
MON.
THIS SCENARIO WILL HAVE TO BE MONITORED VERY CLOSELY TONIGHT...AS
THE AMOUNT OF WARMING AND ONSET OF THE DRIZZLE WILL OBVIOUSLY PLAY
KEY ROLES IN WHERE THE FREEZING DRIZZLE THREAT WILL BE HIGHEST.
AN UPPER LEVEL TROUGH WILL LIFT OUT OF THE DESERT
SOUTHWEST...BRINGING THE TROUGH AXIS ACROSS THE REGION ON WED. THIS
SYSTEM LOOKS LIKE IT COULD PACK A PRETTY GOOD PUNCH WITH GOOD QG
CONVERGENCE...SLOPING FRONTOGENETIC LIFT...AND THE ENERGY FROM THE
UPPER LEVEL SHORTWAVE. TIMING AND POSITIONING WILL PLAY AN IMPORTANT
ROLE AS WARM AIR WILL BE A FACTOR FOR PCPN TYPE.
UNFORTUNATELY...EACH MODEL HAS A DIFFERENT IDEA ON WHAT WILL
OCCUR...AND BRINGS THE FORECAST CONFIDENCE DOWN AS A RESULT. NAM IS
THE QUICKEST OF ALL...TAKING THE SFC LOW TO LAKE SUPERIOR BY 00Z
THU. THE GFS IS OVER SOUTHWEST IA...THE EC THE CENTRAL PLAINS...AND
THE GEM EASTERN IA. A LOT OF INCONSISTENCY WITHIN THE MODELS
TOO...EXCEPT FOR THE EC WHICH SHOWS A BIT BETTER RUN TO RUN
AGREEMENT. WILL LEAN ON THE EC AS A RESULT...BLENDING IT WITH THE
CONSENSUS SOLUTION.
BEFORE THE HEART OF THE SYSTEM MOVES IN WED
AFTERNOON/NIGHT...ANOTHER GOOD SURGE OF LOW LEVEL MOISTURE
TRANSPORT/WARM AIR ADVECTION TUE NIGHT/WED MORNING WILL LIKELY LEAD
TO A BROAD AREA OF PRECIPITATION SPREADING ACROSS PORTIONS OF THE
REGION. SATURATION LOOKS DEEP ENOUGH TO SUPPORT ICE IN THE
CLOUD...BUT WARMING IN THE NEAR SFC LAYER SUGGESTS MELTING AND THE
POTENTIAL FOR RAIN OR FREEZING RAIN. THE WARMING CONTINUES FOR THE
REST OF WED AS THE MAIN PART OF THE STORM MOVES IN...WITH RAIN THE
LIKELY PCPN TYPE AS A RESULT. LOOKS LIKE ANY SNOW BAND WITH THIS
STORM WILL HANG WELL WEST/NORTH. OVERALL...CONFIDENCE IS HIGH THAT
PRECIPITATION WILL OCCUR. WHEN ITS MOST LIKELY IS NOT. CONFIDENCE IS
ALSO RISING THAT IT WILL LIKELY BE RAIN FOR THE MAJORITY OF THE
EVENT.
.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY
250 PM CST SUN DEC 11 2011
MODEL DIFFERENCES CONTINUE...LOWERING CONFIDENCE IN SOME OF THE
DETAILS. WHILE THE GFS HAS MOVED TO A NORTHWEST STORM TRACK ALA THE
ECMWF AND GEM...STILL LOTS OF TIMING VARIANCE ON HOW QUICKLY THE
SYSTEM WILL KICK NORTHEAST. THE GFS IS THE FAST SOLUTION...WITH THE
EC SLOWER AND THE GEM IN BETWEEN. THE EC WOULD LINGER PCPN LONGER
OVER THE FORECAST AREA...CONTINUING INTO THU. ALSO...WITH THE EC
STAYING THE FARTHEST WEST...ITS ALSO MUCH WARMER MAKING RAIN A
MORE LIKELY PCPN TYPE FOR A LONGER STRETCH OF TIME. PCPN TYPE WILL
BE A DIFFICULTY WITH THIS STORM. WILL CONTINUE TO LEAN ON THE
EC/CONSENSUS SOLUTION FOR NOW.
HIGH PRESSURE STARTS TO BUILD IN FROM THE WEST THU NIGHT...MOVING
OVERHEAD FOR SAT WHILE THE UPPER LEVEL FLOW TAKES ON A MORE ZONAL
SHAPE FOR THE WEEKEND. FRI/SAT SHOULD BE DRY WITH SEASONAL TEMPS.
&&
.AVIATION...THROUGH 06Z TUESDAY
1135 PM CST SUN DEC 11 2011
CEILINGS HAVE ACTUALLY LIFTED ACROSS THE AREA THIS EVENING AND
WILL START THE TAFS OUT WITH EITHER MVFR OR VFR CEILINGS BUT WITH
MVFR VISIBILITIES FROM SOME LIGHT FOG. STILL EXPECTING CONDITIONS
TO DETERIORATE LATER TONIGHT AS THE SHORT WAVE TROUGH APPROACHES
AND INCREASES THE LIFT. THE 12.03Z RUC AND 12.00Z NAM NOW SUGGESTS
THE LOWER CEILINGS...VISIBILITY AND DRIZZLE WILL BE SLOWER TO
ARRIVE AND PUSHED THIS BACK TO AROUND 10Z BUT THERE ARE SOME
INDICATIONS IT COULD EVEN HOLD OFF LONGER. TEMPERATURES STILL TO
BE WARM ENOUGH TO KEEP THE PRECIPITATION AS DRIZZLE WITH LITTLE
THREAT FOR ANY FREEZING DRIZZLE AT THE TAF SITES. THE DRIZZLE
SHOULD BEGIN TO TAPER OFF DURING THE AFTERNOON AND HAVE PUSHED
BOTH THE VISIBILITY AND CEILING UP A LITTLE AS THIS OCCURS. THE
LOW LEVEL MOISTURE DOES NOT GET CLEANED OUT OF THE AREA WITH THE
FLOW REMAINING OUT OF THE SOUTH OR SOUTHWEST THROUGH 06Z MONDAY SO
VERY POSSIBLE THAT THE CEILINGS WILL START TO GO DOWN AGAIN MONDAY
EVENING WITH SOME COOLING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
250 PM CST SUN DEC 11 2011
WI...FREEZING RAIN ADVISORY FROM 3 AM TO 9 AM CST MONDAY FOR WIZ017-
029-034-042>044-053>055-061.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM... RIECK
LONG TERM.... RIECK
AVIATION...04
AREA FORECAST DISCUSSION...UPDATED
NWS TALLAHASSEE FL
945 AM EST Mon Dec 12 2011
.UPDATE...Latest RUC analysis shows most of the shortwave energy has
moved east of the CWA along with the bulk of the rainfall. Other
than patches of very light rain, there was only a scattering of
showers over the southeast Big Bend and coastal waters. Patchy light
rain or drizzle may remain possible into the afternoon but will
update grids and zones shortly to trim back PoPs based on radar
coverage. Abundant low level moisture will remain in place today and
the low cloudiness extends through most of Mississippi and spreading
to the west. The clouds will keep max temperatures today below
seasonal levels for all but Dixie county where low 70s are forecast.
&&
.MARINE (Today through Friday)...
High pressure over the Mid-Atlantic states will slowly weaken over
the next several days with conditions gradually improving over the
coastal waters. Winds and seas have diminished to exercise caution
levels this morning and the headline for today will be maintained.
Winds and seas will remain elevated at caution levels, especially
away from the coast through Wednesday before the gradient breaks
down and winds drop below 10 knots for the end of the week.
&&
.AVIATION...(Through 12z Tuesday)...
This set of TAFs remains very similar to the previous set. In
general, ceilings were either in the low end of the MVFR range, or
down into IFR, at TAF issuance time. Ensemble probabilities and MOS
guidance all suggest a prevailing IFR stratus ceiling for most of
the day, with some periods of LIFR possible tonight. Given the
rainfall over the past 12 hours adding a bit more moisture to the
surface, it`s also possible we will see some light fog at the
various terminals after 00z Tuesday, with the best chances being at
TLH and VLD (where winds are likely to be lightest).
&&
.HYDROLOGY...A few corridors of heavy rain overnight prompted the
issuance of several Flood Advisories, the last of which is scheduled
to expire at 7am EST. The Tallahassee area was directly impacted by
one area of heavy rain, with widespread 3 to 5 inch totals across
various parts of the city (heaviest totals generally south and
west). The airport ASOS (KTLH) picked up 3.57 inches through 5:50am
EST, and this is the highest 2-day rainfall total measured at
Tallahassee since January 20-21, 2010. Flooding issues around the
city were mainly related to some minor urban flooding and some
shallow water over a few roads. Another corridor of heavy rain
developed from NC Taylor County into C Madison County, FL. The KTLH
radar estimated 4 to 7.5 inches of rain in a narrow band in this
area, and radar rainfall estimates were pretty reliable overnight
based on observed rainfall. This is also similar to the Q2 estimates
(4-6 inches).
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 62 51 70 49 72 / 60 20 10 0 0
Panama City 61 50 67 50 68 / 40 10 0 0 0
Dothan 54 47 67 48 72 / 50 20 10 0 0
Albany 54 47 66 45 71 / 70 20 10 0 0
Valdosta 61 51 70 49 74 / 70 20 10 0 0
Cross City 73 53 73 50 75 / 60 20 10 0 0
Apalachicola 63 52 69 54 68 / 40 10 10 0 0
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
AL...None.
GA...None.
FL...None.
GM...None.
&&
$$
UPDATE...Barry
MARINE...Wool
AVIATION...Barry/Lamers
HYDROLOGY...Camp/Lamers
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1013 AM EST MON DEC 12 2011
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN IN CONTROL AT THE SURFACE THROUGH THE
MIDDLE OF THE WEEK. ONSHORE LOW LEVEL FLOW AND WARM ADVECTION
PROVIDE INCREASED CHANCES OF LIGHT RAIN TODAY ALONG WITH COOLER
TEMPERATURES. UPPER LEVEL RIDGING WILL BRING WARMING TEMPERATURES
MID WEEK WITH A FRONTAL BOUNDARY EXPECTED TO PUSH INTO THE REGION
LATE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATED FORECAST...TEMPERATURES RUNNING COOLER THAN FORECAST SO
LOWERED MAXIMUM TEMPS INTO THE UPPER 40S SOUTHWEST TO CENTRAL AND
LOWER 50S NORTHEAST...WHERE CHANCES OF PRECIPITATION IS LESS AND
CLOUD COVER THINNER. RAIN COOLED AIR AND A DRY NORTHEAST FLOW WILL
IMPEDE TEMPERATURE RISES. THE REST OF THE FORECAST WAS LEFT UNCHANGED.
PRECIPITATION FORECAST IS EXCELLENT IN DEPICTING EXTEND AND
MOVEMENT OF THE RAINFALL SHIELD WHICH COVERS THE SOUTHERN HALF OF
THE FORECAST AREA.
SHORT WAVE CAUSING THIS ACTIVITY IS NOW IN SOUTHWEST SOUTH
CAROLINA AS DEPICTED BY THE WATER VAPOR SATELLITE LOOP. RUC MODEL
TOO FAST...WENT WITH THE SLOWER NAM MODEL, CLOUDS SHOULD BEGIN
LIFTING LATER THIS AFTERNOON AND THE RAIN WILL END FROM THE
SOUTHWEST AS THE SHORT WAVE LIFTS NORTHEAST TAKING THE ISENTROPIC
LIFT WITH IT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
A BUILDING UPPER RIDGE SETS UP OVER THE FORECAST AREA TUESDAY
INTO WEDNESDAY IN RESPONSE TO A DEEP UPSTREAM TROUGH EJECTING FROM
THE DESERT SOUTHWEST. THIS WILL BRING SOME WEAK DOWNSLOPING FLOW
OFF THE MOUNTAINS AND HELP ERODE THE CLOUDS AND ALLOW FOR A
WARMING TREND THROUGH MID WEEK. TEMPERATURES SHOULD CLIMB ABOVE
NORMAL WITH HIGHS IN THE 60S AND LOWS IN THE UPPER 30S TO LOWER
40S WITH NO CHANCE FOR PRECIPITATION.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
NO LARGE CHANGES TO THE EXTENDED FORECAST. INCREASING CONFIDENCE
REGARDING THE PASSAGE OF A COLD FRONT THROUGH THE FORECAST AREA
LATE WEEK. LATEST GFS AND ECMWF BOTH SHOWING SHORTWAVE ENERGY
LIFTING THROUGH THE GREAT LAKES REGION AND DEVELOPING WESTERLY
ZONAL FLOW BEHIND THE SHORTWAVE WHICH PUSHES THE FRONT NEAR THE
FORECAST AREA ON FRIDAY AND LIKELY STALLS OR SLOWLY PUSHES THROUGH
THE REGION. DELAYED THE ONSET OF POPS TO THURSDAY NIGHT AND FRIDAY
AND GOING WITH A DRY FORECAST ON THURSDAY AND WARMER TEMPERATURES
AHEAD OF THE FRONT. TEMPERATURES FALL BACK TO NORMAL OVER THE
WEEKEND WITH THE FRONT NEARBY.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
CEILINGS LIFTING OVER THE NORTHERN TERMINALS...STAYING THE SAME OR
LOWERING OVER AGS...DNL...OGB. WEAK ISENTROPIC LIFT ASSOCIATED
WITH SHORTWAVE CURRENTLY OVER WESTERN SOUTH CAROLINA WILL SHIFT
EAST BY THIS EVENING...12 Z NAM AND 06Z GFS ARE IN AGREEMENT IN ENDING
ISENTROPIC LIFT BY TONIGHT. IMPROVED CONDITIONS TO VFR AT BOTH CAE
AND CUB WITH THE BULK OF THE PRECIPITATION EXPECTED TO REMAIN
SOUTH OF THESE LOCATIONS.
LOWERED CEILING AT OGB WHERE WITH THE BEST CHANCE OF RAIN IS AND
KEPT THE FORECAST THE SAME AT AGS AND DNL. MADE MINOR CHANGES TO
THE WIND FORECAST. IN ALL LOCATIONS..HOWEVER NORTHEAST WINDS ARE EXPECTED
THROUGH THE REMAINDER OF THIS AFTERNOON. REST LEFT UNCHANGED FOR
NOW. LOW CEILINGS EXTEND BACK INTO WESTERN ALABAMA. WITH THE LACK
OF A STRONG COLD FRONT TO SCOUR OUT THE MOISTURE...MVFR TO IFR
CEILINGS MAY COME BACK ACROSS THE REGION THIS EVENING. THIS WILL
BE MORE CLOSELY LOOKED AT WITH LATER MODEL RUNS.
EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
709 AM CST MON DEC 12 2011
.UPDATE...
UPDATED TO INCLUDE 12Z AVIATION DISCUSSION BELOW.
&&
.DISCUSSION...
SUMMARY...STILL A CONCERN FOR SOME SLICK ROADS IN WESTERN
WISCONSIN...BUT OVERALL FREEZING DRIZZLE WILL NOT BE MUCH OF A
FACTOR THIS MORNING. MIXED PRECIPITATION IS EXPECTED TUESDAY NIGHT
THROUGH WEDNESDAY...BUT WE SHOULD SEE MOSTLY RAIN IN THE TWIN
CITIES METRO.
ALL THE AIRPORT OBSERVATIONS THIS MORNING RANGING BETWEEN 34-39
DEGREES IN MN AND WI. TEMPERATURES HAVE BEEN STEADY ALL NIGHT...SO
DON`T EXPECT MUCH OF A CHANGE THROUGHOUT THE MORNING HOURS. MADE
SOME CALLS TO COUNTIES IN WESTERN WI THIS MORNING. THERE HAVE
BEEN SOME SLICK SPOTS ON ROADS IN RUSK...PRICE...AND TAYLOR
COUNTIES THIS MORNING. EVEN WITH THE AIR TEMPERATURE ABOVE
FREEZING...ROAD PAVEMENT TEMPERATURES ARE RANGING BETWEEN 30-33
DEGREES GIVEN THE FROST IN THE GROUND. UNTREATED ROADS ARE SLICK
WHERE PRECIP IS FALLING IN WESTERN WI. SO FAR EASTERN MN HAS
REMAINED MAINLY DRIZZLE FREE AND TEMPERATURES IN MN ARE A COUPLE
DEGREES WARMER...SO THE SKIN TEMP ON THE ROADS MAY ALSO BE JUST
ABOVE FREEZING. WE`LL LET THE CURRENT FREEZING RAIN ADVISORY IN WI
RIDE FOR NOW AND THE 15Z EXPIRATION IS STILL REASONABLE AT THIS
TIME. 06-09Z RUNS OF THE HRRR HAVE BEEN HANDLING THE CURRENT LIGHT
PRECIP QUITE WELL...EVEN HIGHLIGHTING THE MORE CELLULAR NATURE TO
THE LIGHT RAIN ECHOES IN ARX`S AREA OF SOUTHWEST WI. THE HRRR DOES
SPREAD A MORE UNIFORM AREA OF LIGHT RETURNS FURTHER NORTHWEST INTO
EASTERN MN AND WESTERN WI BETWEEN 11-14Z AND LINGERS IT UNTIL THE
EARLY THIS AFTERNOON. AS A RESULT...HAVE KEPT REASONABLY HIGH POPS
AND MENTION OF DRIZZLE GOING FOR MOST OF THE DAY. THIS ALSO AGREES
WELL WITH THE SATURATION ON THE 280-295K ISENTROPIC SURFACES FROM
THE RUC AND NAM THIS MORNING.
REALLY DIDN`T CHANGE A WHOLE LOT FROM THE PREVIOUS FORECAST WITH
RESPECT TO THE MID WEEK SYSTEM. YESTERDAY`S FORECAST ALREADY
INTRODUCED 70-80% IN MANY LOCATIONS...AND HARD TO GO MUCH HIGHER
WITH THE 12.00Z ECMWF SHOWING A SLIGHTLY SLOWER TREND AND THE
LEADING WAVE OF PRECIP BRACKETING THE 12Z TIME FRAME WEDNESDAY
MORNING. IT`S BECOMING LESS LIKELY THAT WE`LL HAVE MUCH RAIN ON
THE FRONT SIDE OF THIS SYSTEM TUESDAY NIGHT INTO WEDNESDAY
MORNING. 925-850MB TEMPS JUST SEEM TO WARM TOO FAST WHEN THE
ISENTROPIC LIFT KICKS IN. 2M TEMPS ARE STILL NEAR FREEZING DURING
THIS TIME...WITH MOST OF THE GUIDANCE SHOWING 31-35 DEGREES BY
WEDNESDAY MORNING. MUCH LIKE TODAY...WITH AIR TEMPERATURES NEAR
FREEZING AND FROST IN THE GROUND...A LIGHT ICE ACCUMULATION IS
POSSIBLE ON UNTREATED SURFACES. HAVE INCLUDED A MIXTURE OF
RAIN/FREEZING RAIN IN THE FORECAST...AND EVENTUALLY TREND TOWARD
ALL RAIN BY WEDNESDAY AFTERNOON. THE ACTUALLY PV ANOMALY DOESN`T
SWING THROUGH AT THE BASE OF THE 500MB TROF UNTIL 06-12Z THURSDAY.
THE 12.00Z GFS AND ECMWF HAVE SOME SLIGHT TIMING DIFFERENCES WITH
STRENGTHENING AND PROPAGATION OF THE SURFACE REFLECTION BUT THE
OVERALL TRACK IS IN REASONABLE AGREEMENT...ALTHOUGH THE 12.06Z GFS
I SEE IS NOW COMING IN MUCH MORE AGGRESSIVE IN TERMS OF QPF. THE
06-12Z THURSDAY WINDOW IS LIKELY OUR BEST WINDOW FOR ACCUMULATING
SNOWFALL. IT ALL DEPENDS ON HOW FAST THE TEMPERATURE PROFILE
COLLAPSES AND WHERE THE DEFORMATION PRECIP SETS UP ACROSS
SOUTHEAST MN AND WESTERN WI.
OVERALL...THE MID WEEK SYSTEM AT LEAST HAS THE POTENTIAL TO BRING
THE MOST PRECIP WE`VE SEEN IN A COUPLE MONTHS...WHICH REALLY ISN`T
SAYING MUCH GIVEN HOW DRY IT`S BEEN. AFTER A FEW MORE MILD MID
DECEMBER TEMPERATURE DAYS...WE`LL GET A COOL DOWN FOR THURSDAY AND
FRIDAY...BUT HEIGHTS BUILD AGAIN FOR THE WEEKEND.
&&
.AVIATION.../12Z TAF ISSUANCE/
PLENTY OF LOW LEVEL MOISTURE BEING ADVECTED IN FROM THE SOUTH
AHEAD OF A SLUGGISH COLD FRONT DRAPED OVER NRN MN INTO ERN SD
MAKING FOR WIDESPREAD LOW CLOUDS AND PATCHY REDUCED CIGS. WEAK
PRECIP ECHOES ARE BECOMING MORE PREVALENT ON KMPX RADAR THIS
MORNING...PRIMARILY SOUTH AND EAST OF KMSP WHERE PRECIP IS
EXPECTED TO REMAIN THROUGH THE DAY. NOT EXPECTING -FZDZ AS AIR
TEMPS ARE EXPECTED TO REMAIN ABOVE FREEZING...BUT WILL LOOK FOR
PERIODS OF -DZ THROUGH EARLY AFTN. EVEN IF PRECIP DOES NOT REACH
ANY OF THE TERMINALS...MVFR/IFR CIGS WILL BE A PRIMARY CONCERN
WITH MVFR VSBYS SECONDARY. LOW CLOUDS WILL REMAIN IN PLACE THROUGH
THE DAY. WINDS BETWEEN 5-10 KT WILL MAINLY MAKE FOR LOW STRATUS
WITH DECKS THROUGH EARLY AFTN IN THE LOWER RANGE OF MVFR ALTHOUGH
PERIODS OF IFR ARE POSSIBLE. BY THIS EVENING...IFR CIGS WILL BE
PREVALENT WITH MVFR VSBYS. AT TIMES...CIGS MAY DROP TO LIFR BUT
CONFIDENCE IS NOT HIGH ENOUGH ATTM TO GO THAT LOW WHEREAS
CONFIDENCE IS RATHER HIGH OF SEEING IFR...IF NOT LOWER...CIGS.
DEGRADED CONDITIONS WILL REMAIN THROUGH DAYBREAK TUESDAY MORNING.
MSP...MVFR CIGS WILL PREVAIL THROUGH LATE AFTN BUT THE 1700 FT
THRESHOLD WILL BE A TRICKY PROPOSITION TODAY. AM EXPECTING CIGS TO
WOBBLE BETWEEN 1500-1900 FT WHICH MAY CAUSE ISSUES WITH TRAFFIC
MANAGEMENT. AS FOR PRECIP THROUGH THE DAY...-FZDZ IS NOT EXPECTED
WITH A SHALLOW ENOUGH LOW LEVEL LAYER AND SFC TEMPS WELL ABOVE
FREEZING. THEREFORE...ANY PRECIP IS EXPECTED TO BE LIQUID AND NOT
A LOT AT THAT /ONLY UP TO A TENTH OF AN INCH ACCUMULATION/. MVFR
CIGS WILL PREVAIL THROUGH LATE AFTN THEN WILL LOOK FOR CIGS TO
DROP TO IFR WHICH WILL THEN PREVAIL TONIGHT THROUGH TUE MORNING.
LIFR CIGS ARE POSSIBLE DURING THE EARLY MORNING HOURS...BUT
CONFIDENCE NOT THAT HIGH ATTM FOR ITS INCLUSION.
OUTLOOK...MVFR CIGS MAY LINGER THROUGH TUESDAY AS THE FRONT
SETTLES NEAR THE IA/MN BORDER. COMPLEX SYSTEM MOVING SOUTHWEST TO
NORTHEAST ALONG THE FRONT TUE NIGHT THROUGH WED NIGHT WILL BRING
A VARIETY OF FROZEN AND/OR LIQUID PRECIPITATION WITH A HIGH
PROBABILITY OF DEGRADED FLIGHT CATEGORIES. VFR CONDITIONS RETURN
THU AND FRI AS HIGH PRESSURE RETURNS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...FREEZING RAIN ADVISORY UNTIL 9 AM CST THIS MORNING FOR BARRON-
CHIPPEWA-EAU CLAIRE-RUSK.
&&
$$
JPC
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
449 AM CST MON DEC 12 2011
.DISCUSSION...
SUMMARY...STILL A CONCERN FOR SOME SLICK ROADS IN WESTERN
WISCONSIN...BUT OVERALL FREEZING DRIZZLE WILL NOT BE MUCH OF A
FACTOR THIS MORNING. MIXED PRECIPITATION IS EXPECTED TUESDAY NIGHT
THROUGH WEDNESDAY...BUT WE SHOULD SEE MOSTLY RAIN IN THE TWIN
CITIES METRO.
ALL THE AIRPORT OBSERVATIONS THIS MORNING RANGING BETWEEN 34-39
DEGREES IN MN AND WI. TEMPERATURES HAVE BEEN STEADY ALL NIGHT...SO
DON`T EXPECT MUCH OF A CHANGE THROUGHOUT THE MORNING HOURS. MADE
SOME CALLS TO COUNTIES IN WESTERN WI THIS MORNING. THERE HAVE
BEEN SOME SLICK SPOTS ON ROADS IN RUSK...PRICE...AND TAYLOR
COUNTIES THIS MORNING. EVEN WITH THE AIR TEMPERATURE ABOVE
FREEZING...ROAD PAVEMENT TEMPERATURES ARE RANGING BETWEEN 30-33
DEGREES GIVEN THE FROST IN THE GROUND. UNTREATED ROADS ARE SLICK
WHERE PRECIP IS FALLING IN WESTERN WI. SO FAR EASTERN MN HAS
REMAINED MAINLY DRIZZLE FREE AND TEMPERATURES IN MN ARE A COUPLE
DEGREES WARMER...SO THE SKIN TEMP ON THE ROADS MAY ALSO BE JUST
ABOVE FREEZING. WE`LL LET THE CURRENT FREEZING RAIN ADVISORY IN WI
RIDE FOR NOW AND THE 15Z EXPIRATION IS STILL REASONABLE AT THIS
TIME. 06-09Z RUNS OF THE HRRR HAVE BEEN HANDLING THE CURRENT LIGHT
PRECIP QUITE WELL...EVEN HIGHLIGHTING THE MORE CELLULAR NATURE TO
THE LIGHT RAIN ECHOES IN ARX`S AREA OF SOUTHWEST WI. THE HRRR DOES
SPREAD A MORE UNIFORM AREA OF LIGHT RETURNS FURTHER NORTHWEST INTO
EASTERN MN AND WESTERN WI BETWEEN 11-14Z AND LINGERS IT UNTIL THE
EARLY THIS AFTERNOON. AS A RESULT...HAVE KEPT REASONABLY HIGH POPS
AND MENTION OF DRIZZLE GOING FOR MOST OF THE DAY. THIS ALSO AGREES
WELL WITH THE SATURATION ON THE 280-295K ISENTROPIC SURFACES FROM
THE RUC AND NAM THIS MORNING.
REALLY DIDN`T CHANGE A WHOLE LOT FROM THE PREVIOUS FORECAST WITH
RESPECT TO THE MID WEEK SYSTEM. YESTERDAY`S FORECAST ALREADY
INTRODUCED 70-80% IN MANY LOCATIONS...AND HARD TO GO MUCH HIGHER
WITH THE 12.00Z ECMWF SHOWING A SLIGHTLY SLOWER TREND AND THE
LEADING WAVE OF PRECIP BRACKETING THE 12Z TIME FRAME WEDNESDAY
MORNING. IT`S BECOMING LESS LIKELY THAT WE`LL HAVE MUCH RAIN ON
THE FRONT SIDE OF THIS SYSTEM TUESDAY NIGHT INTO WEDNESDAY
MORNING. 925-850MB TEMPS JUST SEEM TO WARM TOO FAST WHEN THE
ISENTROPIC LIFT KICKS IN. 2M TEMPS ARE STILL NEAR FREEZING DURING
THIS TIME...WITH MOST OF THE GUIDANCE SHOWING 31-35 DEGREES BY
WEDNESDAY MORNING. MUCH LIKE TODAY...WITH AIR TEMPERATURES NEAR
FREEZING AND FROST IN THE GROUND...A LIGHT ICE ACCUMULATION IS
POSSIBLE ON UNTREATED SURFACES. HAVE INCLUDED A MIXTURE OF
RAIN/FREEZING RAIN IN THE FORECAST...AND EVENTUALLY TREND TOWARD
ALL RAIN BY WEDNESDAY AFTERNOON. THE ACTUALLY PV ANOMALY DOESN`T
SWING THROUGH AT THE BASE OF THE 500MB TROF UNTIL 06-12Z THURSDAY.
THE 12.00Z GFS AND ECMWF HAVE SOME SLIGHT TIMING DIFFERENCES WITH
STRENGTHENING AND PROPAGATION OF THE SURFACE REFLECTION BUT THE
OVERALL TRACK IS IN REASONABLE AGREEMENT...ALTHOUGH THE 12.06Z GFS
I SEE IS NOW COMING IN MUCH MORE AGGRESSIVE IN TERMS OF QPF. THE
06-12Z THURSDAY WINDOW IS LIKELY OUR BEST WINDOW FOR ACCUMULATING
SNOWFALL. IT ALL DEPENDS ON HOW FAST THE TEMPERATURE PROFILE
COLLAPSES AND WHERE THE DEFORMATION PRECIP SETS UP ACROSS
SOUTHEAST MN AND WESTERN WI.
OVERALL...THE MID WEEK SYSTEM AT LEAST HAS THE POTENTIAL TO BRING
THE MOST PRECIP WE`VE SEEN IN A COUPLE MONTHS...WHICH REALLY ISN`T
SAYING MUCH GIVEN HOW DRY IT`S BEEN. AFTER A FEW MORE MILD MID
DECEMBER TEMPERATURE DAYS...WE`LL GET A COOL DOWN FOR THURSDAY AND
FRIDAY...BUT HEIGHTS BUILD AGAIN FOR THE WEEKEND.
&&
.AVIATION.../06Z TAF ISSUANCE/
WIDESPREAD MVFR CIGS WERE PREVALENT ALONG WITH FEW POCKETS OF IFR
CONDITIONS OVER SOUTH CENTRAL MN AT THIS TIME. SURFACE WINDS HAVE
STAYED UP FOR THE MOST PART ACROSS THE TAF SITES...KEEPING THE
BOUNDARY LAYER WELL MIXED. WATER VAPOR FROM THE SNOW MELT ACROSS THE
PARTS OF NORTHERN IOWA AND SOUTHERN MN...WAS ALSO KEEPING SURFACE
TEMPERATURES FROM LOWERING BELOW THE FREEZING MARK SO FAR. EXPECT
SOME PATCHY LIGHT DRIZZLE TO DEVELOP OVERNIGHT. LIGHT FREEZING
DRIZZLE APPARENTLY MORE LIKELY OVER PARTS OF WEST CENTRAL WISCONSIN
THAN OVER MN...BUT STILL SOMEWHAT OF CONCERN FOR AVIATION INTEREST
WITH NO DEICING EQUIPMENT THE REST OF TONIGHT AND MONDAY MORNING.
STRONG INVERSION ALOFT OVER THE TAF SITES...PRECIP SHOULD BE MAINLY
LIQUID THE REST OF THE DAY(MONDAY). AS THE COLD FRONT THAT IS DRAPED
OVER NORTHERN HALF OF MN...SLOWLY SAGS SOUTH DURING THE
PERIOD...EXPECT MORE WIDESPREAD IFR OR LIFR FLYING CONDITIONS
DEVELOPING OVER THE UPPER MIDWEST LATE IN THE DAY AND OVERNIGHT
MONDAY.
KMSP...MVFR CONDITIONS WILL PERSIST OVERNIGHT WITH CEILINGS OR
VISIBILITIES LOWERING BELOW 1000 FEET AGL AND 3 MILES IN PATCHY MIST
AND FOG. WEATHER CONDITIONS ARE EXPECTED TO LOWER AS A COLD FRONT
DIPS SOUTH LATE IN THE DAY MONDAY/MONDAY NIGHT WITH CEILING LOWERING
BELOW 1000 FEET AND VISIBILITIES 3 MILES IN FOG.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...FREEZING RAIN ADVISORY UNTIL 9 AM CST THIS MORNING FOR BARRON-
CHIPPEWA-EAU CLAIRE-RUSK.
&&
$$
CLF/JVM
AREA FORECAST DISCUSSION
NWS HASTINGS NE
726 AM CST MON DEC 12 2011
.AVIATION...12Z KGRI TAF. GENERALLY POOR AVIATION CONDITIONS ARE
EXPECTED AT KGRI FOR MUCH OF THE NEXT 24 HOURS. THE WIDESPREAD LOW
LEVEL STRATUS ACROSS THE REGION THIS MORNING IS EXPECTED TO
THICKEN OVER THE NEXT FEW HOURS...WITH LOW MVFR CIGS AND VSBY
LIKELY TO RETURN AND PERSIST AT KGRI THROUGH ABOUT 12/18Z.
CEILINGS AND VSBYS WILL EVENTUALLY IMPROVE TO MORE ELEVATED MVFR
LEVELS BY EARLY AFTERNOON...HOWEVER THIS MINOR IMPROVEMENT IS
EXPECTED TO BE VERY SHORT LIVED...WITH LOW MVFR...OR EVEN
IFR...VISIBILITIES AND CEILINGS EXPECTED TO DEVELOP AFTER THE SUN
SETS. IN ADDITION...AN APPROACHING SYSTEM WILL BRING THE CHANCE
FOR SOME LIGHT FREEZING DRIZZLE OR LIGHT FREEZING RAIN LATE IN THE
TAF PERIOD...BUT KEPT AS -DZ FOR CURRENT TAF ISSUANCE AS ONSET IS
VERY NEAR THE END OF CURRENT VALID PERIOD. LIGHT SOUTHERLY WINDS
NEAR 10 KTS THIS MORNING WILL SHIFT MORE WESTERLY THROUGH THE
PERIOD...EVENTUALLY TRANSITIONING FULL CIRCLE OVERNIGHT...BECOMING
NORTHEASTERLY OVERNIGHT TONIGHT.
&&
.PREV DISCUSSION... /ISSUED 556 AM CST MON DEC 12 2011/
SHORT TERM...THROUGH WEDNESDAY NIGHT. PLENTY OF ISSUES TRYING TO
NAIL DOWN PRECIP TYPES/AMOUNTS ETC. DURING THE NEXT FEW DAYS HAS
LED TO A CHALLENGING NIGHT ON THE FORECAST DESK. MAIN CONCERNS
DURING THE NEXT FEW DAYS INVOLVE WHETHER THE CWA WILL SEE ANY
APPRECIABLE RISK OF GENERALLY LIGHT ICING...ALTHOUGH GENERAL
WARMING TREND OF SURFACE TEMPERATURES DURING LAST SEVERAL MODEL
RUNS SEEMS TO BE CONFINING THE MAIN RISK ZONE TO A SMALLER AND
SMALLER AREA OF THE NORTHWEST CWA.
STARTING OFF EARLY THIS MORNING...BEEN AN INTERESTING NIGHT FROM A
TEMP PERSPECTIVE...AS WIDESPREAD STRATUS AND SOUTHERLY BREEZES
HAVE KEPT READINGS SEVERAL DEGREES ABOVE FREEZING ACROSS THE VAST
MAJORITY OF THE CWA...RESULTING IN A SOMEWHAT RARE MODEST
OVERNIGHT SNOW MELT FOR THIS TIME OF YEAR. MAIN CONCERNS
OVERNIGHT...AND THROUGH THE NEXT FEW/SEVERAL HOURS ARE ACROSS THE
FAR WESTERN PORTIONS OF THE CWA...WHERE WEB CAMS AND AUTOMATED OBS
HAVE SUGGESTED THAT THERE IS A NARROW CORRIDOR OF LOCALLY DENSE
FOG LIKELY LURKING NEAR/WITHIN WESTERN PORTIONS OF DAWSON...GOSPER
AND FURNAS COUNTIES. THIS FOG IS GENERALLY TIED TO THE EDGE OF THE
EXPANSIVE LOW CLOUD DECK COVERING MUCH OF THE REGION...ALONG WHICH
THERE IS QUITE A TEMP GRADIENT INCLUDING A STRIKING 26 DEGREE
DIFFERENCE BETWEEN HOLDREGE AND MCCOOK AT 11Z. WITH ANY DENSE FOG
SEEMINGLY AFFECTING SUCH A SMALL PORTION OF THE AREA...HAVE OPTED
AGAINST AN ADVISORY...BUT HAVE IT MENTIONED IN THE GRIDS AND ALSO
IN THE HWO. AS FOR ANY LIGHT FREEZING DRIZZLE CONCERNS FROM 12-24
HOURS AGO...THESE HAVE APPARENTLY BEEN AVOIDED FOR NOW GIVEN THE
SEASONABLY MILD OVERNIGHT TEMPS...AND EVEN PLAIN LIGHT DRIZZLE HAS
APPARENTLY BEEN QUITE SCANT OVERNIGHT ACROSS THE AREA.
A QUICK LOOK AT 11Z OBJECTIVE SURFACE ANALYSIS PLACES A WEAK
TROUGH AXIS NEAR THE EDGE OF THE STRATUS/NEAR THE WESTERN EDGE OF
THE CWA...WITH STEADY SOUTH BREEZES 5-15 MPH AFFECTING NEARLY ALL
OF THE CWA TO THE EAST OF THIS AXIS. ALOFT...WATER VAPOR IMAGERY
AND SHORT TERM MODEL DATA CONFIRM THE PRESENCE OF A FAIRLY WEAK
MID LEVEL SHORTWAVE STARTING TO DEPART EASTERN NEB TO THE EAST-
NORTHEAST...WITH LOW STRATUS CEILINGS ACTUALLY RISING QUITE A BIT
IN MUCH OF THE CWA IN ITS WAKE. UPSTREAM...THE MAIN LARGE-SCALE
TROUGH OF CONCERN IS STILL CENTERED NEAR THE PACIFIC COAST.
FOR TODAY...THE MAIN CONCERN THIS MORNING IS WHETHER ANY DENSE
FOG ALONG THE STRATUS EDGE CAN WORK A BIT FARTHER EASTWARD INTO
THE AREA. FOR NOW HAVE DENSE FOG MENTION CONFINED SOLELY TO PARTS
OF DAWSON...GOSPER...FURNAS. AS FOR SKY COVER...LATEST SUGGESTIONS
FROM HRRR MODEL IS THAT STRATUS SHOULD HOLD FIRM ACROSS MOST OF
THE CWA THROUGH THE DAY...ALTHOUGH ROUGHLY THE WESTERN 1/4 OF THE
AREA COULD SEE SOME PARTIAL CLEARING ALONG/WEST OF THE WEAK LOW
LEVEL TROUGH AXIS. DEFINITELY SOMETHING TO WATCH. TEMP
WISE...GIVEN THE WARM START RAISED HIGHS ROUGHLY 3-4 DEGREES OVER
PREVIOUS FORECAST MOST AREAS...AND POSSIBLY NOT ENOUGH. WILL AIM
FOR A GRADIENT FROM MID 30S NORTHWEST TO LOW 40S SOUTHEAST...AND
MAYBE EVEN UPPER 40S IN THE MITCHELL COUNTY KS AREA. LIMITED LIFT
SHOULD KEEP ANY POTENTIAL DRIZZLE AT BAY TODAY.
TONIGHT...MAIN CHANGE WAS TO RAISE LOW TEMPS A NOTABLE 4-8 DEGREES
OVER PREVIOUS FORECAST MOST AREAS...ALTHOUGH THIS IS VERY
DEPENDENT ON WIDESPREAD CLOUD COVER HOLDING FIRM. ASSUMING THIS
OCCURS...AM NOW TALKING A GRADIENT FROM LOW-MID 20S NORTHWEST TO
LOW-MID 30S SOUTHEAST. WITH LIGHT WINDS...CANNOT RULE OUT PATCHY
TO AREAS OF FOG OVERNIGHT...BUT NOTHING THAT CAN REALLY BE PINNED
DOWN FOR POSSIBLE DENSE DEVELOPMENT. KEPT THEME FROM PREVIOUS
FORECAST INTACT...WITH SLIGHT CHANCE OF DRIZZLE IN THE SOUTH
BEFORE MIDNIGHT...AND THEN BETTER CHANCES FOR LIGHT MEASURABLE
PRECIP AFTER MIDNIGHT MAINLY ACROSS THE SOUTHERN HALF OF THE CWA
AS FIRST LEAD SHORTWAVE MOVES INTO THE REGION. COULD SEE LIGHT
ICING MAINLY ACROSS NEB ZONES...BUT NOT ANTICIPATING MAJOR ISSUES
AND DAY SHIFT SHOULD BE ABLE TO BETTER PIN DOWN THE SURFACE TEMP
TREND.
TUESDAY...RAISED POPS 10-20 PERCENT OVER PREVIOUS FORECAST MAINLY
FOR THE AFTERNOON...WITH 60-80 POPS NOW OVER MUCH OF THE
CENTRAL/SOUTHEAST CWA. ALSO RAISED HIGHS 2-4 DEGREES MOST
AREAS...WITH ANY RISK FOR FREEZING RAIN DURING THE DAY LARGELY
CONFINED TO LOCATIONS NORTHWEST OF A GREELEY-ELWOOD LINE...AND
EVEN THIS AREA MAY BE OVERDONE IF THE ECMWF/GFS HAVE A DECENT
HANDLE ON SURFACE TEMPS. HAVE HIGHS RANGING FROM THE MID 30S
NORTHWEST TO LOW-MID 40S IN KS ZONES AND AROUND HEBRON.
TUESDAY NIGHT...FORCING FROM INCOMING MID LEVEL WAVE AND UPPER
LEVEL JET INCREASE...AND HAVE AT LEAST 50 POPS CWA-WIDE...AND
LIKELIES MAINLY ACROSS THE EASTERN 1/3. COULD EASILY SEE SLIGHTLY
RISING/AT LEAST STEADY TEMPS THROUGH THE NIGHT...WITH ANY MENTION
OF FREEZING RAIN NOW CONFINED MAINLY TO VALLEY...SHERMAN...DAWSON
COUNTIES. WITH BOTH THE NAM/GFS PULLING AT LEAST 100-300 J/KG OF
MUCAPE INTO THE CWA...AND THE SREF PROBABILITIES INCREASING FOR
GENERAL THUNDER...EVEN INTRODUCED AN ISOLATED THUNDER MENTION TO
ROUGHLY THE SOUTHEAST 1/2 OF THE CWA OVERNIGHT...WHICH MAY OR MAY
NOT EXTEND INTO WED AS WELL BUT DON/T HAVE IT IN THERE YET.
WED INTO WED NIGHT...THE MAIN MID LEVEL WAVE MOVES DIRECTLY
THROUGH THE REGION...WITH ALL PRECIP LIKELY OVER BY MIDNIGHT. HAVE
LIKELY POPS ALREADY IN PLACE ACROSS ROUGHLY THE EASTERN 1/2 OF THE
CWA ALREADY...WHICH MAY NEED EXTENDED WESTWARD IN LATER UPDATES.
UNLESS MODELS SUDDENLY START TRENDING COLDER...THIS SHOULD BE A
FAIRLY WIDESPREAD LIGHT-MODERATE RAIN EVENT...WITH ONLY THE
SMALLEST CHANCE OF FREEZING RAIN IN FAR NORTHWEST ZONES WED
MORNING. AS THE SYSTEM DEPARTS WED EVENING...CAN`T RULE OUT A VERY
BRIEF PERIOD OF SNOW OR RAIN/SNOW MIX IN THE NORTHEAST. RAISED WED
HIGHS 2-3 DEGREES ON AVERAGE...NOW RANGING FROM UPPER 30S
NORTHWEST TO LOW 50S FAR SOUTHEAST.
IN SUMMARY...MAIN CONCERN OVER NEXT FEW DAYS IS WHETHER OR NOT
FREEZING RAIN WILL AMOUNT TO ANYTHING. DESPITE RECENT WARMING
TRENDS IN MODELS...CURRENTLY HAVE 1-2 HUNDREDTHS OF ICE POTENTIAL
IN MANY AREAS...AND LOCATIONS GENERALLY NORTHWEST OF A GREELEY TO
ELWOOD LINE UP TO AROUND 5 HUNDREDTHS TOTAL. ALTHOUGH THIS WOULD
BE ENOUGH TO CAUSE AT LEAST MINOR ISSUES...CONFIDENCE IN WHETHER
IT WILL OCCUR AT ALL IS STILL LOW ENOUGH TO PRECLUDE ANYTHING
BEYOND AN HWO MENTION. BESIDES...WOULD GENERALLY PREFER TO SEE
TEMPS INTO THE 20S VERSUS LOW 30S/AROUND 30 FOR ICING TO REALLY
TAKE HOLD...AND FOR MOST OF THE NEXT FEW DAYS THIS IS NOT THE CASE
DURING ANTICIPATED TIMES OF PRECIPITATION.
LONG TERM...12Z THURSDAY THROUGH SUNDAY...A RELATIVELY QUIET
WEATHER PATTERN APPEARS TO BE IN STORE FOR THE END OF THE WORK WEEK
AS A SPLIT UPPER LEVEL FLOW PATTERN WILL RESULT IN SHORT WAVE
RIDGING ACROSS THE CENTRAL PLAINS BEHIND WEDNESDAYS DEPARTING
DISTURBANCE. UNDER THIS PATTERN...NORTHWESTERLY FLOW ALOFT WILL
CARRY MULTIPLE UPPER LEVEL DISTURBANCES ACROSS THE NORTHERN PLAINS
AS A CUT OFF LOW MEANDERS ACROSS THE DESERT SOUTHWEST...RESULTING IN
DRY AND SEASONABLE CONDITIONS LOCALLY. QUESTION WILL BE LATE IN THE
EXTENDED WHEN THE AFOREMENTIONED LOW EJECTS INTO THE PLAINS...AS THE
EC AND GFS HAVE DISTINCTLY DIFFERENT SOLUTIONS FOR EARLY NEXT
WEEK...WITH THE GFS TAKING A MUCH MORE NORTHERLY AND WETTER TRACK
LOCALLY WITH THIS LOW AND THE EC KEEPING THE SYSTEM FURTHER SOUTH.
DUE TO THE UNCERTAINTY IN TRACK AND TIMING OF THIS NEXT SYSTEM AS
WELL AS PER COORDINATION WITH SURROUNDING OFFICES...MENTIONED MAINLY
SLIGHT CHANCES FOR PRECIP LATE IN THE UPCOMING WEEKEND AS MOISTURE
ADVECTS NORTHWARD AHEAD OF THE MAIN AREA OF LOW PRESSURE...MOST
LIKELY IN THE FORM OF RAIN OR A RAIN SNOW MIX.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...PFANNKUCH
LONG TERM/AVIATION...ROSSI
AREA FORECAST DISCUSSION
NWS HASTINGS NE
556 AM CST MON DEC 12 2011
.SHORT TERM...THROUGH WEDNESDAY NIGHT. PLENTY OF ISSUES TRYING TO
NAIL DOWN PRECIP TYPES/AMOUNTS ETC. DURING THE NEXT FEW DAYS HAS
LED TO A CHALLENGING NIGHT ON THE FORECAST DESK. MAIN CONCERNS
DURING THE NEXT FEW DAYS INVOLVE WHETHER THE CWA WILL SEE ANY
APPRECIABLE RISK OF GENERALLY LIGHT ICING...ALTHOUGH GENERAL
WARMING TREND OF SURFACE TEMPERATURES DURING LAST SEVERAL MODEL
RUNS SEEMS TO BE CONFINING THE MAIN RISK ZONE TO A SMALLER AND
SMALLER AREA OF THE NORTHWEST CWA.
STARTING OFF EARLY THIS MORNING...BEEN AN INTERESTING NIGHT FROM A
TEMP PERSPECTIVE...AS WIDESPREAD STRATUS AND SOUTHERLY BREEZES
HAVE KEPT READINGS SEVERAL DEGREES ABOVE FREEZING ACROSS THE VAST
MAJORITY OF THE CWA...RESULTING IN A SOMEWHAT RARE MODEST
OVERNIGHT SNOW MELT FOR THIS TIME OF YEAR. MAIN CONCERNS
OVERNIGHT...AND THROUGH THE NEXT FEW/SEVERAL HOURS ARE ACROSS THE
FAR WESTERN PORTIONS OF THE CWA...WHERE WEB CAMS AND AUTOMATED OBS
HAVE SUGGESTED THAT THERE IS A NARROW CORRIDOR OF LOCALLY DENSE
FOG LIKELY LURKING NEAR/WITHIN WESTERN PORTIONS OF DAWSON...GOSPER
AND FURNAS COUNTIES. THIS FOG IS GENERALLY TIED TO THE EDGE OF THE
EXPANSIVE LOW CLOUD DECK COVERING MUCH OF THE REGION...ALONG WHICH
THERE IS QUITE A TEMP GRADIENT INCLUDING A STRIKING 26 DEGREE
DIFFERENCE BETWEEN HOLDREGE AND MCCOOK AT 11Z. WITH ANY DENSE FOG
SEEMINGLY AFFECTING SUCH A SMALL PORTION OF THE AREA...HAVE OPTED
AGAINST AN ADVISORY...BUT HAVE IT MENTIONED IN THE GRIDS AND ALSO
IN THE HWO. AS FOR ANY LIGHT FREEZING DRIZZLE CONCERNS FROM 12-24
HOURS AGO...THESE HAVE APPARENTLY BEEN AVOIDED FOR NOW GIVEN THE
SEASONABLY MILD OVERNIGHT TEMPS...AND EVEN PLAIN LIGHT DRIZZLE HAS
APPARENTLY BEEN QUITE SCANT OVERNIGHT ACROSS THE AREA.
A QUICK LOOK AT 11Z OBJECTIVE SURFACE ANALYSIS PLACES A WEAK
TROUGH AXIS NEAR THE EDGE OF THE STRATUS/NEAR THE WESTERN EDGE OF
THE CWA...WITH STEADY SOUTH BREEZES 5-15 MPH AFFECTING NEARLY ALL
OF THE CWA TO THE EAST OF THIS AXIS. ALOFT...WATER VAPOR IMAGERY
AND SHORT TERM MODEL DATA CONFIRM THE PRESENCE OF A FAIRLY WEAK
MID LEVEL SHORTWAVE STARTING TO DEPART EASTERN NEB TO THE EAST-
NORTHEAST...WITH LOW STRATUS CEILINGS ACTUALLY RISING QUITE A BIT
IN MUCH OF THE CWA IN ITS WAKE. UPSTREAM...THE MAIN LARGE-SCALE
TROUGH OF CONCERN IS STILL CENTERED NEAR THE PACIFIC COAST.
FOR TODAY...THE MAIN CONCERN THIS MORNING IS WHETHER ANY DENSE
FOG ALONG THE STRATUS EDGE CAN WORK A BIT FARTHER EASTWARD INTO
THE AREA. FOR NOW HAVE DENSE FOG MENTION CONFINED SOLELY TO PARTS
OF DAWSON...GOSPER...FURNAS. AS FOR SKY COVER...LATEST SUGGESTIONS
FROM HRRR MODEL IS THAT STRATUS SHOULD HOLD FIRM ACROSS MOST OF
THE CWA THROUGH THE DAY...ALTHOUGH ROUGHLY THE WESTERN 1/4 OF THE
AREA COULD SEE SOME PARTIAL CLEARING ALONG/WEST OF THE WEAK LOW
LEVEL TROUGH AXIS. DEFINITELY SOMETHING TO WATCH. TEMP
WISE...GIVEN THE WARM START RAISED HIGHS ROUGHLY 3-4 DEGREES OVER
PREVIOUS FORECAST MOST AREAS...AND POSSIBLY NOT ENOUGH. WILL AIM
FOR A GRADIENT FROM MID 30S NORTHWEST TO LOW 40S SOUTHEAST...AND
MAYBE EVEN UPPER 40S IN THE MITCHELL COUNTY KS AREA. LIMITED LIFT
SHOULD KEEP ANY POTENTIAL DRIZZLE AT BAY TODAY.
TONIGHT...MAIN CHANGE WAS TO RAISE LOW TEMPS A NOTABLE 4-8 DEGREES
OVER PREVIOUS FORECAST MOST AREAS...ALTHOUGH THIS IS VERY
DEPENDENT ON WIDESPREAD CLOUD COVER HOLDING FIRM. ASSUMING THIS
OCCURS...AM NOW TALKING A GRADIENT FROM LOW-MID 20S NORTHWEST TO
LOW-MID 30S SOUTHEAST. WITH LIGHT WINDS...CANNOT RULE OUT PATCHY
TO AREAS OF FOG OVERNIGHT...BUT NOTHING THAT CAN REALLY BE PINNED
DOWN FOR POSSIBLE DENSE DEVELOPMENT. KEPT THEME FROM PREVIOUS
FORECAST INTACT...WITH SLIGHT CHANCE OF DRIZZLE IN THE SOUTH
BEFORE MIDNIGHT...AND THEN BETTER CHANCES FOR LIGHT MEASURABLE
PRECIP AFTER MIDNIGHT MAINLY ACROSS THE SOUTHERN HALF OF THE CWA
AS FIRST LEAD SHORTWAVE MOVES INTO THE REGION. COULD SEE LIGHT
ICING MAINLY ACROSS NEB ZONES...BUT NOT ANTICIPATING MAJOR ISSUES
AND DAY SHIFT SHOULD BE ABLE TO BETTER PIN DOWN THE SURFACE TEMP
TREND.
TUESDAY...RAISED POPS 10-20 PERCENT OVER PREVIOUS FORECAST MAINLY
FOR THE AFTERNOON...WITH 60-80 POPS NOW OVER MUCH OF THE
CENTRAL/SOUTHEAST CWA. ALSO RAISED HIGHS 2-4 DEGREES MOST
AREAS...WITH ANY RISK FOR FREEZING RAIN DURING THE DAY LARGELY
CONFINED TO LOCATIONS NORTHWEST OF A GREELEY-ELWOOD LINE...AND
EVEN THIS AREA MAY BE OVERDONE IF THE ECMWF/GFS HAVE A DECENT
HANDLE ON SURFACE TEMPS. HAVE HIGHS RANGING FROM THE MID 30S
NORTHWEST TO LOW-MID 40S IN KS ZONES AND AROUND HEBRON.
TUESDAY NIGHT...FORCING FROM INCOMING MID LEVEL WAVE AND UPPER
LEVEL JET INCREASE...AND HAVE AT LEAST 50 POPS CWA-WIDE...AND
LIKELIES MAINLY ACROSS THE EASTERN 1/3. COULD EASILY SEE SLIGHTLY
RISING/AT LEAST STEADY TEMPS THROUGH THE NIGHT...WITH ANY MENTION
OF FREEZING RAIN NOW CONFINED MAINLY TO VALLEY...SHERMAN...DAWSON
COUNTIES. WITH BOTH THE NAM/GFS PULLING AT LEAST 100-300 J/KG OF
MUCAPE INTO THE CWA...AND THE SREF PROBABILITIES INCREASING FOR
GENERAL THUNDER...EVEN INTRODUCED AN ISOLATED THUNDER MENTION TO
ROUGHLY THE SOUTHEAST 1/2 OF THE CWA OVERNIGHT...WHICH MAY OR MAY
NOT EXTEND INTO WED AS WELL BUT DON/T HAVE IT IN THERE YET.
WED INTO WED NIGHT...THE MAIN MID LEVEL WAVE MOVES DIRECTLY
THROUGH THE REGION...WITH ALL PRECIP LIKELY OVER BY MIDNIGHT. HAVE
LIKELY POPS ALREADY IN PLACE ACROSS ROUGHLY THE EASTERN 1/2 OF THE
CWA ALREADY...WHICH MAY NEED EXTENDED WESTWARD IN LATER UPDATES.
UNLESS MODELS SUDDENLY START TRENDING COLDER...THIS SHOULD BE A
FAIRLY WIDESPREAD LIGHT-MODERATE RAIN EVENT...WITH ONLY THE
SMALLEST CHANCE OF FREEZING RAIN IN FAR NORTHWEST ZONES WED
MORNING. AS THE SYSTEM DEPARTS WED EVENING...CAN`T RULE OUT A VERY
BRIEF PERIOD OF SNOW OR RAIN/SNOW MIX IN THE NORTHEAST. RAISED WED
HIGHS 2-3 DEGREES ON AVERAGE...NOW RANGING FROM UPPER 30S
NORTHWEST TO LOW 50S FAR SOUTHEAST.
IN SUMMARY...MAIN CONCERN OVER NEXT FEW DAYS IS WHETHER OR NOT
FREEZING RAIN WILL AMOUNT TO ANYTHING. DESPITE RECENT WARMING
TRENDS IN MODELS...CURRENTLY HAVE 1-2 HUNDREDTHS OF ICE POTENTIAL
IN MANY AREAS...AND LOCATIONS GENERALLY NORTHWEST OF A GREELEY TO
ELWOOD LINE UP TO AROUND 5 HUNDREDTHS TOTAL. ALTHOUGH THIS WOULD
BE ENOUGH TO CAUSE AT LEAST MINOR ISSUES...CONFIDENCE IN WHETHER
IT WILL OCCUR AT ALL IS STILL LOW ENOUGH TO PRECLUDE ANYTHING
BEYOND AN HWO MENTION. BESIDES...WOULD GENERALLY PREFER TO SEE
TEMPS INTO THE 20S VERSUS LOW 30S/AROUND 30 FOR ICING TO REALLY
TAKE HOLD...AND FOR MOST OF THE NEXT FEW DAYS THIS IS NOT THE CASE
DURING ANTICIPATED TIMES OF PRECIPITATION.
.LONG TERM...12Z THURSDAY THROUGH SUNDAY...A RELATIVELY QUIET
WEATHER PATTERN APPEARS TO BE IN STORE FOR THE END OF THE WORK WEEK
AS A SPLIT UPPER LEVEL FLOW PATTERN WILL RESULT IN SHORT WAVE
RIDGING ACROSS THE CENTRAL PLAINS BEHIND WEDNESDAYS DEPARTING
DISTURBANCE. UNDER THIS PATTERN...NORTHWESTERLY FLOW ALOFT WILL
CARRY MULTIPLE UPPER LEVEL DISTURBANCES ACROSS THE NORTHERN PLAINS
AS A CUT OFF LOW MEANDERS ACROSS THE DESERT SOUTHWEST...RESULTING IN
DRY AND SEASONABLE CONDITIONS LOCALLY. QUESTION WILL BE LATE IN THE
EXTENDED WHEN THE AFOREMENTIONED LOW EJECTS INTO THE PLAINS...AS THE
EC AND GFS HAVE DISTINCTLY DIFFERENT SOLUTIONS FOR EARLY NEXT
WEEK...WITH THE GFS TAKING A MUCH MORE NORTHERLY AND WETTER TRACK
LOCALLY WITH THIS LOW AND THE EC KEEPING THE SYSTEM FURTHER SOUTH.
DUE TO THE UNCERTAINTY IN TRACK AND TIMING OF THIS NEXT SYSTEM AS
WELL AS PER COORDINATION WITH SURROUNDING OFFICES...MENTIONED MAINLY
SLIGHT CHANCES FOR PRECIP LATE IN THE UPCOMING WEEKEND AS MOISTURE
ADVECTS NORTHWARD AHEAD OF THE MAIN AREA OF LOW PRESSURE...MOST
LIKELY IN THE FORM OF RAIN OR A RAIN SNOW MIX.
&&
.PREV DISCUSSION... /ISSUED 945 PM CST SUN DEC 11 2011/
AVIATION...12Z KGRI TAF. GENERALLY POOR AVIATION CONDITIONS ARE
EXPECTED AT KGRI FOR MUCH OF THE NEXT 24 HOURS. THE WIDESPREAD LOW
LEVEL STRATUS ACROSS THE REGION THIS MORNING IS EXPECTED TO
THICKEN OVER THE NEXT FEW HOURS...WITH LOW MVFR CIGS AND VSBY
LIKELY TO RETURN AND PERSIST AT KGRI THROUGH ABOUT 12/18Z.
CEILINGS AND VSBYS WILL EVENTUALLY IMPROVE TO MORE ELEVATED MVFR
LEVELS BY EARLY AFTERNOON...HOWEVER THIS MINOR IMPROVEMENT IS
EXPECTED TO BE VERY SHORT LIVED...WITH LOW MVFR...OR EVEN
IFR...VISIBILITIES AND CEILINGS EXPECTED TO DEVELOP AFTER THE SUN
SETS. IN ADDITION...AN APPROACHING SYSTEM WILL BRING THE CHANCE
FOR SOME LIGHT FREEZING DRIZZLE OR LIGHT FREEZING RAIN LATE IN THE
TAF PERIOD...BUT KEPT AS -DZ FOR CURRENT TAF ISSUANCE AS ONSET IS
VERY NEAR THE END OF CURRENT VALID PERIOD. LIGHT SOUTHERLY WINDS
NEAR 10 KTS THIS MORNING WILL SHIFT MORE WESTERLY THROUGH THE
PERIOD...EVENTUALLY TRANSITIONING FULL CIRCLE OVERNIGHT...BECOMING
NORTHEASTERLY OVERNIGHT TONIGHT.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...PFANNKUCH
LONG TERM/AVIATION...ROSSI
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
933 AM EST MON DEC 12 2011
.SYNOPSIS...
HIGH PRESSURE WILL DOMINATE THE REGIONS WEATHER INTO TUESDAY. THE
HIGH WILL MOVE EAST TUESDAY NIGHT AS A WARM FRONT APPROACHES THE
AREA FROM THE SOUTHWEST. THE WARM FRONT WILL PUSH ACROSS THE
REGION ON WEDNESDAY...FOLLOWED BY A COLD FRONT WEDNESDAY NIGHT
INTO THURSDAY. TEMPERATURES WILL WARM TO ABOVE NORMAL READINGS
THROUGH THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SURFACE HIGH PRESSURE EXTENDED FROM THE NEW ENGLAND COAST
TO THE THE OHIO AND TENNESSEE VALLEYS THIS MORNING. THE HIGH IS
EXPECTED TO MOVE LITTLE TODAY. AFTER A COLD START...TEMPERATURES
WILL MODERATE UNDER ABUNDANT SUNSHINE. CIRRUS WILL INCREASE IN
COVERAGE BUT IT WILL REMAIN MOSTLY SUNNY. HIGHS WILL RANGE FROM
THE LOWER 40S NORTH TO THE UPPER 40S SOUTH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
SURFACE HIGH PRESSURE WILL REESTABLISH ITSELF OVER THE OHIO VALLEY
TONIGHT INTO TUESDAY. MEANWHILE...WEAK UPR LVL ENERGY WILL TRACK
ACROSS THE GREAT LAKES. RETURN LOW LEVEL FLOW MAY BRING SOME LOWER
CLOUDS TO OUR SE CWFA THIS EVENING/OVERNIGHT WHILE MID LVL
MOISTURE STREAMS IN FROM THE WEST. CLOUD COVER WILL PREVENT
TEMPERATURES FROM COOLING OFF TOO MUCH AND SHOULD RANGE FROM THE
MID 20S TO THE LOWER 30S. SKIES ON TUESDAY WILL RANGE FROM
PARTLY TO MOSTLY CLOUDY AS MID LVL MOISTURE CONTINUES TO ADVECT
ACROSS THE REGION FROM THE WEST. HIGHS WILL VARY FROM THE MID 40S
NORTH TO NEAR 50 SOUTH.
MODELS ARE IN GOOD AGREEMENT FOR TUESDAY NIGHT INTO WEDNESDAY.
SURFACE HIGH WILL MOVE EAST AS A WARM FRONT DEVELOPS TO OUR
SOUTHWEST. THE WARM FRONT WILL MOVE ACROSS THE AREA ON WEDNESDAY.
DEEP MOISTURE WILL INCREASE OVER THE REGION THROUGH THE PERIOD.
THIS MOISTURE WILL COINCIDE WITH A STRONG LOW LEVEL JET AND UPR
LVL DIVERGENCE FROM THE RR QUAD OF AN UPR LVL JET. THIS WILL
RESULT IN SHOWERS WITH THE HIGHEST THREAT POISED FOR THE NRN
ZONES. HAVE RAISED POPS TO CATEGORICAL ACRS NRN AREAS TUESDAY
NIGHT INTO WEDNESDAY. PCPN CHANCES WILL DIMINISH TO LOW CHANCE
SOUTH OF THE OHIO RIVER.
THE WARM FRONT WILL LIFT NORTH OF THE AREA WEDNESDAY NIGHT. THE
WARM FRONT WILL BE FOLLOWED BY A COLD FRONT WHICH WILL PUSH
SOUTHEAST ACROSS THE REGION ON THURSDAY. DEEP MOISTURE COUPLED
WITH DECENT LOW LEVEL FORCING AHEAD OF THE FRONT WILL BRING
ANOTHER ROUND OF SHOWERS. HAVE GONE WITH CATEGORICAL POPS. THE
FRONT WILL PUSH SOUTHEAST THURSDAY NIGHT AS HIGH PRESSURE BUILDS
INTO THE WESTERN GREAT LAKES. THIS WILL BRING AN END TO THE PCPN.
TEMPERATURES TUESDAY NIGHT INTO THURSDAY NIGHT WILL EXHIBIT NON
DIURNAL TRENDS AND HAVE RELIED ON A BLEND OF RAW 2 M GFS AND ECMWF
FOR THE MOST PART.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
HIGH PRESSURE WILL BUILD INTO THE AREA FOR THE WEEKEND. A WEAK
SHORT WAVE MAY DROP DOWN ACROSS THE GREAT LAKES ON SATURDAY...BUT
IT LOOKS LIKE BETTER FORCING WITH THIS WILL REMAIN OFF TO OUR
NORTH SO WILL THEREFORE MAINTAIN A DRY FORECAST THROUGH THE
REMAINDER OF THE LONG TERM PERIOD. COOLER AIR WILL FILTER IN
BEHIND THE FRONT LATE IN THE WEEK...LEADING TO A RETURN TO MORE
SEASONABLE TEMPERATURES THROUGH THE WEEKEND.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
HIGH PRESSURE WILL MEANDER OVER THE UPPER OHIO VALLEY REGION
THROUGH THE NEXT DAY OR SO. THIS WILL BRING LIGHT TO CALM WINDS
(OCCASIONALLY UP TO AROUND 5 KNOTS OUT OF THE SOUTH). SOME CIRRUS
WILL SPILL INTO THE REGION TODAY...WITH MID CLOUDS POSSIBLE
OVERNIGHT AND EARLY TUESDAY.
OUTLOOK...NO SIGNIFICANT WEATHER EXPECTED.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HICKMAN
NEAR TERM...CONIGLIO/HICKMAN
SHORT TERM...HICKMAN
LONG TERM...HICKMAN/JGL
AVIATION...HATZOS
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
627 AM EST MON DEC 12 2011
.SYNOPSIS...
HIGH PRESSURE WILL DOMINATE THE REGIONS WEATHER INTO TUESDAY. THE
HIGH WILL MOVE EAST TUESDAY NIGHT AS A WARM FRONT APPROACHES THE
AREA FROM THE SOUTHWEST. THE WARM FRONT WILL PUSH ACROSS THE
REGION ON WEDNESDAY...FOLLOWED BY A COLD FRONT WEDNESDAY NIGHT
INTO THURSDAY. TEMPERATURES WILL WARM TO ABOVE NORMAL READINGS
THROUGH THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SURFACE HIGH PRESSURE EXTENDED FROM THE NEW ENGLAND COAST
TO THE THE OHIO AND TENNESSEE VALLEYS THIS MORNING. THE HIGH IS
EXPECTED TO MOVE LITTLE TODAY. AFTER A COLD START...TEMPERATURES
ARE EXPECTED TO MODERATE UNDER ABUNDANT SUNSHINE. HIGHS WILL RANGE
FROM THE LOWER 40S NORTH TO THE UPPER 40S SOUTH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
SURFACE HIGH PRESSURE WILL REESTABLISH ITSELF OVER THE OHIO VALLEY
TONIGHT INTO TUESDAY. MEANWHILE...WEAK UPR LVL ENERGY WILL TRACK
ACROSS THE GREAT LAKES. RETURN LOW LEVEL FLOW MAY BRING SOME LOWER
CLOUDS TO OUR SE CWFA THIS EVENING/OVERNIGHT WHILE MID LVL
MOISTURE STREAMS IN FROM THE WEST. CLOUD COVER WILL PREVENT
TEMPERATURES FROM COOLING OFF TOO MUCH AND SHOULD RANGE FROM THE
MID 20S TO THE LOWER 30S. SKIES ON TUESDAY WILL RANGE FROM
PARTLY TO MOSTLY CLOUDY AS MID LVL MOISTURE CONTINUES TO ADVECT
ACROSS THE REGION FROM THE WEST. HIGHS WILL VARY FROM THE MID 40S
NORTH TO NEAR 50 SOUTH.
MODELS ARE IN GOOD AGREEMENT FOR TUESDAY NIGHT INTO WEDNESDAY.
SURFACE HIGH WILL MOVE EAST AS A WARM FRONT DEVELOPS TO OUR
SOUTHWEST. THE WARM FRONT WILL MOVE ACROSS THE AREA ON WEDNESDAY.
DEEP MOISTURE WILL INCREASE OVER THE REGION THROUGH THE PERIOD.
THIS MOISTURE WILL COINCIDE WITH A STRONG LOW LEVEL JET AND UPR
LVL DIVERGENCE FROM THE RR QUAD OF AN UPR LVL JET. THIS WILL
RESULT IN SHOWERS WITH THE HIGHEST THREAT POISED FOR THE NRN
ZONES. HAVE RAISED POPS TO CATEGORICAL ACRS NRN AREAS TUESDAY
NIGHT INTO WEDNESDAY. PCPN CHANCES WILL DIMINISH TO LOW CHANCE
SOUTH OF THE OHIO RIVER.
THE WARM FRONT WILL LIFT NORTH OF THE AREA WEDNESDAY NIGHT. THE
WARM FRONT WILL BE FOLLOWED BY A COLD FRONT WHICH WILL PUSH
SOUTHEAST ACROSS THE REGION ON THURSDAY. DEEP MOISTURE COUPLED
WITH DECENT LOW LEVEL FORCING AHEAD OF THE FRONT WILL BRING
ANOTHER ROUND OF SHOWERS. HAVE GONE WITH CATEGORICAL POPS. THE
FRONT WILL PUSH SOUTHEAST THURSDAY NIGHT AS HIGH PRESSURE BUILDS
INTO THE WESTERN GREAT LAKES. THIS WILL BRING AN END TO THE PCPN.
TEMPERATURES TUESDAY NIGHT INTO THURSDAY NIGHT WILL EXHIBIT NON
DIURNAL TRENDS AND HAVE RELIED ON A BLEND OF RAW 2 M GFS AND ECMWF
FOR THE MOST PART.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
HIGH PRESSURE WILL BUILD INTO THE AREA FOR THE WEEKEND. A WEAK
SHORT WAVE MAY DROP DOWN ACROSS THE GREAT LAKES ON SATURDAY...BUT
IT LOOKS LIKE BETTER FORCING WITH THIS WILL REMAIN OFF TO OUR
NORTH SO WILL THEREFORE MAINTAIN A DRY FORECAST THROUGH THE
REMAINDER OF THE LONG TERM PERIOD. COOLER AIR WILL FILTER IN
BEHIND THE FRONT LATE IN THE WEEK...LEADING TO A RETURN TO MORE
SEASONABLE TEMPERATURES THROUGH THE WEEKEND.
&&
.AVIATION /11Z MONDAY THROUGH FRIDAY/...
HIGH PRESSURE WILL MEANDER OVER THE UPPER OHIO VALLEY REGION
THROUGH THE NEXT DAY OR SO. THIS WILL BRING LIGHT TO CALM WINDS
(OCCASIONALLY UP TO AROUND 5 KNOTS OUT OF THE SOUTH). SOME CIRRUS
WILL SPILL INTO THE REGION TODAY...WITH MID CLOUDS POSSIBLE
OVERNIGHT AND EARLY TUESDAY.
OUTLOOK...NO SIGNIFICANT WEATHER EXPECTED.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HICKMAN
NEAR TERM...HICKMAN
SHORT TERM...HICKMAN
LONG TERM...HICKMAN/JGL
AVIATION...HATZOS
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
947 AM EST MON DEC 12 2011
.SYNOPSIS...
HIGH PRESSURE WILL BE CENTERED OVER THE MID ATLANTIC THROUGH MUCH OF
THE FIRST HALF OF THE WEEK. A MOIST FLOW OFF THE ATLANTIC AND NORTH
ACROSS FLORIDA AND GEORGIA WILL RESULT IN CLOUDY SKIES AND SOME RAIN
TODAY AND THEN DRIER WEATHER WILL RETURN INTO MID WEEK. A COLD
FRONT WILL APPROACH TOWARD THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM...WATER VAPOR IMAGERY AND RUC 500 MB HEIGHT FIELDS SHOW
A SHORTWAVE LIFTING NE THROUGH THE THE CENTRAL CAROLINAS MID
MORNING. THIS FEATURE SHOULD LIFT ANY LINGERING LIGHT PIEDMONT
PRECIPITATION EAST OF THE AREA BY NOON. LOW LEVEL WARM AND MOIST
ADVECTION WILL CONTINUE FROM THE SW...HOWEVER...SO THE CLOUDS SHOULD
BE HERE TO STAY OVER THE NOSE OF SFC HIGH PRES...WITH SLIGHT CHC TO
CHC POPS STILL WARRANTED FOR THE SW PART OF THE AREA THROUGH THE
AFTN. WILL MAINTAIN A DECENT GRADIENT ON MAX T FROM MID TO UPPER 40S
IN NE GA/WRN UPSTATE TO LOWER 50S INTERSTATE 77 AREA THIS AFTN.
THE SFC HIGH WILL RETROGRADE WWD TONIGHT AS HEIGHTS RISE ALOFT. 850
MB FLOW WILL STEADILY VEER W THEN NW THROUGH THE OVERNIGHT HOURS.
ANY SPRINKLES SHOULD BE CONFINED MAINLY TO MTN AREAS...WITH
DOWNSLOPING POSSIBLY ALLOWING SOME SCATTERING IN THE
FOOTHILLS/PIEDMONT CLOUDS. LINGERING CLOUDS AND LIGHT MIXING SHOULD
ALLOW MIN TEMPS TO RUN 5 TO 10 DEGREES ABOVE NORMAL MOST AREAS.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 200 AM MONDAY...UPPER LEVEL HEIGHTS ATOP THE SE CONUS WILL BE
RISING ON TUESDAY. THE COOLISH NORTHERLY LLVL FLOW IS PROGGED TO
WEAKEN...AND AN ACCOMPANYING RISE IN 100-85H THICKNESS SHOULD BOOST
MAX TEMPS TO ABT 8 DEG F ABOVE CLIMO...AS PER THE LATEST MOS BLEND.
UPPER LEVEL RIDGE AXIS WILL CONTINUE TO BUILD EAST THRU WEDNESDAY...
ALIGNING ITSELF ATOP THE CWFA AND AIDING IN THE CONTINUATION OF FAIR
WX CONDITIONS. MILD LLVL RETURN FLOW INCREASES AND SHOULD SUPPORT
MAX TEMPS A FEW DEG F WARMER THAN PERSISTENCE.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 230 AM MONDAY...THE MEDIUM RANGE MODELS AGREE ON THE UPPER
RIDGE BREAKING DOWN OVER THE SOUTHEAST WITH THE AXIS FROM FLORIDA TO
EASTERN VIRGINIA EARLY THURSDAY. BY 00Z FRIDAY...THE RIDGE WILL
HAVE SIGNIFICANTLY FLATTENED OUT WITH THE STRONG SHORTWAVE CROSSING
THE GREAT LAKES. THE SLOW MOVING COLD FRONT WILL DRAPE SW TO NE
ACROSS THE SOUTHERN APPALACHIANS. FROM THURSDAY INTO THURSDAY NIGHT
WAVES OF LOW PRESSURE WILL ENHANCE PRECIP ALONG THE FRONT. THE
SUPPORTING ENERGY WILL MOVE OUT FRIDAY WITH VERY LITTLE RAIN OVER
THE AREA. THE NEW ECMWF BRINGS ANOTHER SHORTWAVE RAPIDLY ACROSS THE
PLAINS AND MISS VALLEY SATURDAY INDUCING THE SURFACE RESPONSE ACROSS
THE SOUTHEAST ALONG THE FRONT. THIS LAST BATCH OF RAIN WILL MOVE
EAST OF OUR AREA SATURDAY NIGHT. HIGH PRESSURE WILL BE IN CONTROL
SUNDAY AND SUNDAY NIGHT WITH DRY WEATHER. TEMPERATURES WILL BE
ABOVE NORMAL IN THE MEDIUM RANGE...MUCH ABOVE THURS AND FRI...THEN
ONLY A FEW DEGREES ABOVE NORMAL OVER THE WEEKEND FOR HIGH TEMPS.
WITH CLOUDINESS...LOWS WILL BE MUCH ABOVE NORMAL.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
AT KCLT AND ELSEWHERE...A SURFACE RIDGE STRETCHING FROM THE DELMARVA
TO THE WESTERN CAROLINAS WILL MAINTAIN NE WINDS IN THE 5 TO 10 KT
RANGE THROUGHOUT TODAY...EXCEPT SOUTHEAST AT KAVL. THE SFC RIDGING
WILL ACTUALLY BUILD WWD TOWARD THE MTN CHAIN TONIGHT AS HEIGHTS RISE
FROM THE WEST ALOFT. WINDS WILL DIMINISH THIS EVENING. LOW VFR TO
MVFR STRATOCUMULUS WILL PERSIST ACROSS THE REGION IN MOIST...WARM
ADVECTION FLOW THROUGH THE DAY...BUT ANY LIGHT LINGERING PRECIP
SHOULD MOVE EAST OF THE AREA WITH AN UPPER LEVEL SHORTWAVE BY 18Z.
SOME LIGHT PRECIP COULD RETURN THIS EVENING FROM THE SW...BUT THIS
APPEARS UNLIKELY TO IMPACT ANY OF THE TAF SITES. WILL KEEP
CONDITIONS VFR THROUGH THE EVENING...WITH SCATTERING OVERNIGHT AS
850 MB FLOW TURNS A WESTERLY DOWNSLOPE.
OUTLOOK...GENERALLY DRY CONDITIONS SHOULD PERSIST UNTIL AT LEAST
THURSDAY...WHEN A COLD FRONT WILL APPROACH FROM THE WEST.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...DEO
NEAR TERM...HG
SHORT TERM...CSH
LONG TERM...DEO
AVIATION...HG
AREA FORECAST DISCUSSION
NWS AMARILLO TX
443 AM CST MON DEC 12 2011
.DISCUSSION...
TODAY-TONIGHT: HAVE SEEN SOME PATCHY AREAS OF FOG ACROSS THE
PANHANDLES THIS MORNING...BUT STRONGER SURFACE WINDS HAVE PRECLUDED
ANY DENSE FOG CONCERNS. EXPECT PATCHY FOG TO CONTINUE THROUGH MOST
OF THE MORNING HOURS SOUTH AND EAST OF A LINE FROM DALHART TO GUYMON.
MUCH LOWER VISIBILITIES HAVE BEEN NOTED ACROSS THE SOUTH PLAINS WHERE
SURFACE/LOW-LEVEL WINDS HAVE WEAKENED...PER KLBB VAD DATA. RUC DATA
INDICATES WINDS ACROSS THE PANHANDLES MAY ALSO WEAKEN...AND IF THIS
OCCURS...VISIBILITIES WILL LIKELY DETERIORATE. STILL NOT EXPECTING
ANY DENSE FOG ISSUES AS SURFACE WINDS SHOULD REMAIN ABOVE 10
MPH...BUT WILL MONITOR CLOSELY. WOULDN/T BE SURPRISED TO SEE SOME
DRIZZLE ACROSS THE FAR SOUTHEAST TEXAS PANHANDLE THROUGH 9 AM WHERE
FORECAST SOUNDINGS INDICATE THE LOW-LEVEL MOISTURE WILL REMAIN
AROUND 2000 FT DEEP...BUT SINCE THIS IS ON THE MARGINAL END FOR
DRIZZLE...LEFT OUT OF THE FORECAST FOR NOW. OTHERWISE...EXPECT MOST
OF THE AREA TO REMAIN GRUNGED IN WITH LOW CLOUDS FOR MOST OF THE DAY.
AS A RESULT...HIGH TEMPERATURES WILL CONTINUE TO REMAIN BELOW
SEASONAL NORMS. IT IS INTERESTING TO NOTE THAT THE AVERAGE DAILY
TEMPERATURE AT AMARILLO...BORGER...DALHART...AND GUYMON HAS NOT BEEN
ABOVE NORMAL SINCE NOVEMBER 30. AS ISENTROPIC ASCENT INCREASES THIS
EVENING AND OVERNIGHT...PRECIPITATION CHANCES WILL ALSO INCREASE. QPF
AMOUNTS WILL BE LIGHT WITH MOST LOCATIONS SEEING LESS THAN 0.10"
THROUGH SUNRISE ON TUESDAY. EXPECTING THE PRECIPITATION TYPE TO BE
ALL LIQUID AS WARM AIR ADVECTION...MOISTURE ADVECTION...AND LOW
CLOUDS SHOULD KEEP TEMPERATURES ABOVE FREEZING. ONCE AGAIN...ANOTHER
ROUND OF PATCHY FOG IS EXPECTED DEVELOP AREAWIDE...BUT THE RAIN SHOULD
KEEP THE NEAR GROUND AIR MIXED ENOUGH TO LIMIT ANY DENSE FOG
CONCERNS.
TUESDAY-TUESDAY NIGHT: PATCHY FOG MAY LINGER INTO THE LATE MORNING
HOURS ON TUESDAY. OTHERWISE...ANOTHER DREARY DAY IS EXPECTED WITH LOW
CLOUDS AND INCREASING PRECIPITATION CHANCES...ESPECIALLY AFTER NOON.
MAX TEMPS WILL ONCE AGAIN BE ON THE COOL SIDE. MET AND MAV GUIDANCE
APPEAR TOO HIGH...SO FOLLOWED RAW NAM TEMPERATURES CLOSELY. BY
TUESDAY AFTERNOON...FORECAST SOUNDINGS INDICATE SOME WEAK ELEVATED
INSTABILITY DEVELOPING ACROSS MOST OF THE PANHANDLES AS LOW-LEVEL
MOISTURE INCREASES AND MID-LEVEL LAPSE RATES STEEPEN. KEPT
THUNDERSTORMS IN THE FORECAST AND SHIFTED THEM SLIGHTLY WESTWARD.
STRONGER MOISTURE ADVECTION IS EXPECTED ACROSS MOST OF THE AREA ON
TUESDAY NIGHT....AND IN FACT...THE ECMWF...GGEM...AND GFS ALL SHOW
SURFACE DEW POINTS IN THE MID TO UPPER 50S ACROSS THE SOUTHEAST TEXAS
PANHANDLE! IT/S AMAZING TO REALIZE THAT WE STRUGGLED TO SEE DEW
POINTS THAT HIGH DURING THE SPRING AND SUMMER...BUT IT/S POSSIBLE
THEY MAY REACH THAT HIGH IN DECEMBER. REGARDLESS...AS FORCING FOR
ASCENT IMPINGES ON THE MOIST AND WEAKLY UNSTABLE AIR
MASS...PRECIPITATION AND THUNDERSTORM CHANCES WILL REALLY RAMP UP
TUESDAY EVENING AND NIGHT. WITHIN THE LAST COUPLE OF WEEKS...HAVE
NOTICED THAT THE SUBTROPICAL JET HAS HAD A CONNECTION TO THE
TROPICS...AND THIS LOOKS TO BE THE CASE AGAIN WITH THIS SYSTEM. AS A
RESULT...WON/T BE SURPRISED TO SEE RAINFALL AMOUNTS OVERACHIEVE IN
SOME LOCATIONS. REGARDING THUNDERSTORM POTENTIAL...FORECAST
SOUNDINGS ARE SHOWING UP TO 300 J/KG OF MUCAPE ALONG WITH DEEP LAYER
SHEAR AROUND 70 KT. AS A RESULT...MAY SEE A FEW STRONG STORMS PRODUCE
SMALL HAIL TUESDAY AFTERNOON THROUGH TUESDAY NIGHT. NOT EXPECTING ANY
WINTRY PRECIPITATION AS SURFACE AND LOW-LEVEL TEMPERATURES WILL
REMAIN ABOVE FREEZING.
WEDNESDAY-WEDNESDAY NIGHT: THE DRY SLOT WILL QUICKLY SWEEP ACROSS THE
FORECAST AREA DURING THE DAY. THERE MAY BE ENOUGH LINGERING LOW-
LEVEL MOISTURE ACROSS THE FAR EASTERN PANHANDLES DURING THE MORNING
FOR A CHANCE OF PRECIPITATION. KEPT THUNDERSTORMS IN THE
FORECAST...BUT FORECAST SOUNDINGS INDICATING LESS THAN 50 J/KG OF
MUCAPE. THANKS TO THE DRY SLOT...THE SUN WILL MAKE AN APPEARANCE
ACROSS THE REGION. HIGH TEMPERATURES SHOULD BE ABLE TO RISE INTO THE
50S AND POSSIBLY 60S AS STRONG DOWNSLOPING WINDS DEVELOP. SPEAKING OF
THE WINDS...EXPECT THEM TO STRENGTHEN BY LATE WEDNESDAY MORNING INTO
THE MID-AFTERNOON HOURS. FORECAST SOUNDINGS INDICATE MIXING HEIGHTS WILL
BE RELATIVELY SHALLOW AND WILL NOT BE ABLE TO TAP INTO THE HIGH
MOMENTUM MID-LEVEL AIR. NONETHELESS...FORECAST SOUNDINGS ARE SHOWING
30-35 KT FLOW AT THE TOP OF THE BOUNDARY LAYER. CONTINUED TO KEEP
WINDS BELOW ADVISORY CRITERIA...ESPECIALLY SINCE MET WINDS ARE
TRENDING LOWER. HOWEVER...IF THE GFS IS CORRECT...COULD SEE ADVISORY
LEVEL WINDS...ESPECIALLY ON THE CAPROCK. AS THE UPPER TROUGH AND
ATTENDANT SURFACE LOW MOVE INTO THE UPPER MISSISSIPPI VALLEY...A COLD
FRONT WILL PUSH SOUTHWARD ACROSS THE PANHANDLES WITH MUCH COOLER AND
DRIER AIR FILTERING INTO THE AREA. AS THE AFOREMENTIONED SYNOPTIC
FEATURES PULL AWAY FROM THE AREA...THE PRESSURE GRADIENT WILL ALSO
RELAX...ALLOWING WINDS TO QUICKLY SUBSIDE UNDER 10 MPH BY SUNRISE
THURSDAY.
THURSDAY-THURSDAY NIGHT: DRY AND SUB-SEASONAL TEMPERATURES ARE
EXPECTED AS NNE UPSLOPE WINDS PREVAIL THROUGH THE DAY. DUE TO THE
UPSLOPE WINDS...LOWERED HIGHS IN ALL AREAS. A CHILLY NIGHT IS
EXPECTED WITH LOWS IN THE 20S AND LOWER 30S.
FRIDAY-MONDAY: STILL A LOT OF UNCERTAINTIES DURING THIS TIME PERIOD.
THE DGEX AND GFS CONTINUE TO REMAIN FASTER WITH THE CUTOFF LOW THAN
THE ECMWF AND GGEM. JUST NOTICED THE NEW 06 UTC GFS HAS NOW TRENDED
SLOWER WITH THE CLOSED LOW AND IS MORE SIMILAR TO THE ECMWF AND
GGEM. EXPECT PRECIPITATION TO DEVELOP ACROSS THE SOUTHWEST TEXAS
PANHANDLE SATURDAY EVENING BEFORE SPREADING ACROSS ALL OF THE
FORECAST AREA SATURDAY NIGHT. RAIN IS LIKELY SATURDAY EVENING AND
THEN POSSIBLY MIXING WITH OR CHANGING TO SNOW SATURDAY NIGHT. SOME
INDICATIONS THAT LOW-LEVEL THERMAL PROFILES MAY BE A LITTLE WARM FOR
SNOW...BUT DUE TO THE UNCERTAINTY...KEPT A RAIN/SNOW MIX IN THE
FORECAST. BEYOND SUNDAY...CONSIDERABLE UNCERTAINTY EXISTS...BUT
FOLLOWED MORE CLOSELY TO THE ECMWF FOR NOW. IF IT DOES VERIFY...WE
COULD BE LOOKING AT MORE WINTER MISCHIEF BY EARLY NEXT WEEK. STILL
PLENTY OF TIME TO WATCH THIS SYSTEM SO STAY TUNED.
JACKSON
&&
.FIRE WEATHER...
RELATIVE HUMIDITY VALUES ARE EXPECTED TO REMAIN ABOVE 30 PERCENT
ACROSS ALL OF THE PANHANDLES FOR THE NEXT SEVEN DAYS. AS A
RESULT...NO ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMARILLO TX 48 40 49 43 58 / 5 30 50 50 5
BEAVER OK 50 39 49 45 55 / 5 30 50 60 20
BOISE CITY OK 44 36 45 36 51 / 5 20 50 50 10
BORGER TX 50 42 48 45 58 / 5 30 50 60 10
BOYS RANCH TX 50 40 49 43 57 / 5 30 50 50 5
CANYON TX 48 41 49 43 60 / 5 30 50 50 5
CLARENDON TX 50 41 50 48 61 / 10 30 50 60 20
DALHART TX 49 36 49 35 54 / 5 30 50 50 5
GUYMON OK 48 36 48 41 55 / 5 20 50 60 10
HEREFORD TX 48 42 49 43 58 / 5 30 50 50 5
LIPSCOMB TX 50 41 49 47 57 / 5 30 50 60 20
PAMPA TX 48 41 48 45 57 / 5 30 50 60 20
SHAMROCK TX 51 40 50 49 63 / 10 30 50 60 20
WELLINGTON TX 51 41 52 49 65 / 10 30 50 60 20
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
17/13
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
534 AM CST MON DEC 12 2011
.SHORT TERM...TODAY THROUGH WEDNESDAY
331 AM CST MON DEC 12 2011
FORECAST CONCERNS ARE ON DRIZZLE/FREEZING DRIZZLE THIS MORNING AND
AGAIN TONIGHT AND THE POTENTIAL FOR AREAS OF FOG LATE TONIGHT INTO
TUESDAY MORNING. FOCUS THEN TURNS TO STORM SYSTEM EXPECTED TO
IMPACT THE AREA TUESDAY NIGHT INTO WEDNESDAY...WITH PRECIPITATION
TYPE CONCERNS.
CURRENT RADAR AND SURFACE OBSERVATIONS SHOWED DRIZZLE FALLING
ACROSS MUCH OF THE FORECAST AREA. AREAS OF FREEZING DRIZZLE HAVE
BEEN REPORTED ACROSS NORTH CENTRAL WISCONSIN THROUGH SOUTHWEST
WISCONSIN...WITH SOME SECONDARY ROADWAYS VERY SLICK.
DRIZZLE WILL CONTINUE ACROSS THE AREA THIS MORNING AS LOW LEVEL
MOISTURE CONTINUES TO STREAM INTO THE REGION FROM THE SOUTHERN
PLAINS. ISENTROPIC LIFT ON THE 280-300K SURFACE ALONG WITH A WEAK
SHORTWAVE TROUGH MOVING ACROSS THE REGION...WILL ACT TO PRODUCE
DRIZZLE ACROSS MUCH OF THE FORECAST AREA THROUGH THIS AFTERNOON.
SURFACE TEMPERATURES HAVE WARMED ABOVE FREEZING ACROSS MUCH OF THE
FORECAST AREA EARLY THIS MORNING. HOWEVER...SOME SECONDARY ROADWAYS
AND SHADED LOCATIONS WILL LIKELY HAVE SURFACE TEMPERATURES AROUND
FREEZING AND SHOULD EXPERIENCE SOME LIGHT ICING. WILL CONTINUE THE
FREEZING DRIZZLE ADVISORY THROUGH 9 AM FOR THIS LIGHT ICING
POTENTIAL. DRIZZLE AND CLOUDY SKIES CAN BE EXPECTED INTO THIS
EVENING...WITH THE DRIZZLE GRADUALLY TAPERING OFF DURING THE LATE
EVENING INTO THE OVERNIGHT HOURS. SOME PATCHY FREEZING DRIZZLE CAN
BE EXPECTED ACROSS WESTERN AND CENTRAL WISCONSIN...WHERE A FEW
LOCATIONS WILL DROP TO FREEZING. AT THIS TIME IT APPEARS ICING WILL
BE MINIMAL BUT WILL HAVE TO CLOSELY MONITOR TEMPERATURES THROUGH THE
DAY TODAY. IF TEMPERATURES COOL FURTHER THAN WHAT IS CURRENTLY
ANTICIPATED...A FREEZING RAIN ADVISORY MAY BE NEEDED THIS EVENING
INTO TONIGHT...ESPECIALLY ALONG AND NORTH OF THE I-94 CORRIDOR. LOOK
FOR LOW TEMPERATURES TO FALL INTO THE LOWER 30S TONIGHT UNDER CLOUDY
SKIES.
LOW LEVEL MOISTURE WILL REMAIN IN PLACE ACROSS THE AREA ON TUESDAY
WITH WEAK RIDGING ALOFT MOVING OVERHEAD. WITH LIGHT AND VARIABLE
WINDS ACROSS THE REGION AND ANY REMAINING SNOW MELTING...AREAS OF
FOG MAY DEVELOP AND COULD POTENTIALLY BE DENSE EARLY TUESDAY MORNING.
HAVE ADDED AREAS OF FOG TO THE FORECAST LATE MONDAY NIGHT THROUGH
MID MORNING TUESDAY. STRATUS LOOKS TO PERSIST ACROSS MUCH OF THE
FORECAST AREA WITH MOSTLY CLOUDY SKIES EXPECTED. ANY VERTICAL MOTION
MOVING ACROSS THE REGION COULD TRIGGER SOME LIGHT DRIZZLE.
TEMPERATURES SHOULD BE ABOVE FREEZING ON TUESDAY...WITH HIGHS IN THE
MID 30S TO AROUND 40 SO ICING SHOULD NOT BE A CONCERN.
AN UPPER LEVEL TROUGH IS EXPECTED TO MOVE FROM THE SOUTHWEST CONUS
INTO THE CENTRAL PLAINS LATE TUESDAY NIGHT. WARM AIR ADVECTION ALOFT
WILL SPREAD ACROSS THE REGION...WITH RAIN AND SNOW DEVELOPING ACROSS
MUCH OF THE FORECAST AREA. AT THIS TIME FORECAST SOUNDINGS APPEAR
WARM ENOUGH FOR THE PRECIPITATION TO FALL AS RAIN. TEMPERATURES LOOK
TO FALL INTO THE 33 TO 36 DEGREE RANGE LATE TUESDAY EVENING THEN
GRADUALLY WARM AFTER MIDNIGHT. WILL HAVE TO CLOSELY MONITOR THE NEXT
FEW MODEL RUNS...IF TEMPERATURES DO NOT WARM AS ANTICIPATED A BRIEF
PERIOD OF FREEZING RAIN MAY DEVELOP LATE TUESDAY NIGHT. HAVE KEPT
PRECIPITATION TYPES AS RAIN/SNOW TUESDAY NIGHT GIVEN THE EXPECTED
TEMPERATURES. FORECAST SOUNDINGS ARE SHOWING SOME ELEVATED CAPE
ACROSS MUCH OF THE FORECAST AREA...WITH AROUND 150 J/KG LIFTING
FROM 730 MB. IF THE ELEVATED CAPE CONTINUES IN THE NEXT SET OF
MODEL RUNS...ISOLATED THUNDER MAY NEED TO BE ADDED TO THE FORECAST
LATE TUESDAY NIGHT INTO EARLY WEDNESDAY MORNING.
12.00 GFS AND ECMWF ARE IN REASONABLE AGREEMENT ON WEDNESDAY SHOWING
RAIN PERSISTING THROUGH THE DAY ACROSS THE FORECAST AREA AS THE
UPPER LEVEL TROUGH MOVES FROM THE CENTRAL PLAINS INTO THE UPPER
MISSISSIPPI RIVER VALLEY. THE NAM KEEPS THE BULK OF THE PRECIPITATION
ACROSS SOUTHEAST IOWA THROUGH NORTHERN ILLINOIS. HAVE LEANED MORE
TOWARD THE GFS AND ECMWF SOLUTION. FELT THE GFS WAS A BIT OVERDONE
ACROSS SOUTHEAST MINNESOTA INTO NORTHWEST WISCONSIN...PAINTING MUCH
HEAVIER PRECIPITATION ACROSS THE AREA WITH A DEEPER SURFACE LOW OVER
THE OTHER MODELS. A COLD FRONT IS EXPECTED TO MOVE ACROSS THE
FORECAST AREA LATE WEDNESDAY NIGHT INTO EARLY THURSDAY MORNING WITH
TEMPERATURES FALLING. RAIN SHOULD GRADUALLY CHANGE OVER TO SNOW FROM
NORTHWEST TO SOUTHEAST AS COOLER AIR FILTERS INTO THE AREA. LIGHT
SNOW ACCUMULATION IS POSSIBLE...BUT EXACTLY HOW MUCH WILL FALL WILL
DEPEND ON THE TRACK OF THE LOW AND WHEN THE COOLER AIR WRAPS INTO
THE REGION. LOOK FOR LOW TEMPERATURES TO OCCUR LATE IN THE
NIGHT...WITH TEMPS FALLING INTO THE UPPER 20S ACROSS SOUTHEAST
MINNESOTA THOUGH NORTH CENTRAL WISCONSIN TO THE MID 30S ACROSS FAR
SOUTHWEST WISCONSIN.
.LONG TERM...THURSDAY THROUGH SUNDAY
331 AM CST MON DEC 12 2011
MUCH COLDER AIR WILL PUSH INTO THE AREA ON THURSDAY IN THE WAKE OF A
COLD FRONT...WITH 850 MB TEMPERATURES FALLING FROM 1 C EARLY
THURSDAY MORNING...TO -8 C BY EARLY THURSDAY EVENING. LOOK FOR
TEMPERATURES TO FALL THROUGH THE DAY...WITH READINGS IN THE MID
20S BY LATE THURSDAY AFTERNOON. SOME LIGHT SNOW MAY LINGER ACROSS
THE AREA ON THURSDAY BUT SHOULD QUICKLY TAPER OFF INTO THE
AFTERNOON AS COLD HIGH PRESSURE STARTS TO BUILD IN. LOOK FOR LOWS
TO FALL INTO THE TEENS THURSDAY NIGHT. THE HIGH IS EXPECTED TO
REMAIN OVER THE AREA INTO THE WEEKEND WITH COOL AND QUIET WEATHER
ANTICIPATED. HIGHS WILL BE MAINLY IN THE 20S WITH LOWS IN THE
TEENS. MODELS ARE SHOWING A WARM UP FOR SUNDAY WITH HIGHS CLIMBING
BACK INTO THE MID TO UPPER 30S.
&&
.AVIATION...TODAY AND TONIGHT
534 AM CST MON DEC 12 2011
ABUNDANT LOW LEVEL MOISTURE ALONG WITH A SHORTWAVE TROUGH MOVING
THROUGH MINNESOTA HAS RESULTED IN WIDESPREAD DRIZZLE ACROSS THE
AREA. MOST OF THE PRECIPITATION THUS FAR HAS BEEN AFFECTING THE
KLSE TAF SITE...BUT EXPECT DRIZZLE AT KRST AT TIMES THROUGH MUCH
OF THE DAY ALSO. CEILINGS HAVE REMAINED IN THE UPPER MVFR TO LOWER VFR
CATEGORIES. HOWEVER....BOTH THE 12.07Z RUC AND 13.06Z NAM BUFKIT
SOUNDING CONTINUE TO INDICATE LOWERING CEILINGS THIS MORNING
BETWEEN 12Z-15Z. DID LOWER CEILINGS INTO THE LOWER MVFR
CATEGORY...BUT WILL HAVE WATCH CLOSELY FOR ANY IFR CONDITIONS.
PRECIPITATION WILL COME TO AN END THIS EVENING...WITH A FEW POCKET
OF FREEZING DRIZZLE STILL POSSIBLE. HOWEVER...FELL BETTER CHANCES WILL
BE TO THE EAST OF THE TAF SITES. PRESSURE GRADIENT DOES RELAX
TONIGHT AND WITH THE CONTINUATION OF LOW LEVEL MOISTURE...EXPECT
CEILINGS TO ONCE AGAIN LOWER INTO THE IFR CATEGORY. WITH AN
ADDITIONAL INFLUX OF MOISTURE FROM MELTING SNOW WOULD EXPECT FOG
FORMATION TO OCCUR. DID LOWER VISIBILITIES INTO THE IFR CATEGORY
AFTER 05Z AT BOTH SITES...BUT CANNOT RULE OUT DENSE FOG WITH
VISIBILITIES UNDER ONE QUARTER OF A MILE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
331 AM CST MON DEC 12 2011
WI...FREEZING RAIN ADVISORY UNTIL 9 AM CST THIS MORNING FOR WIZ017-
029-034-042>044-053>055-061.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM....WETENKAMP
AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
112 PM EST MON DEC 12 2011
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN IN CONTROL AT THE SURFACE THROUGH THE
MIDDLE OF THE WEEK. ONSHORE LOW LEVEL FLOW AND WARM ADVECTION
PROVIDE INCREASED CHANCES OF LIGHT RAIN TODAY ALONG WITH COOLER
TEMPERATURES. UPPER LEVEL RIDGING WILL BRING WARMING TEMPERATURES
MID WEEK WITH A FRONTAL BOUNDARY EXPECTED TO PUSH INTO THE REGION
LATE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
RADAR TRENDS SHOW THE BULK OF THE RAIN MOVING NORTHEAST SOUTHEAST
OF A WILLISTON TO LYNCHBURG LINE. ONLY WIDELY SCATTERED SHOWERS
ARE PRESENT ON RADAR ACROSS EAST CENTRAL GEORGIA AND CENTRAL SOUTH
CAROLINA AS THE SHORTWAVE WORKS ITS WAY ACROSS SOUTH CAROLINA. AS A
RESULT...MOVED PRECIPITATION NORTHEAST AND OUT OF THE AREA BY 00Z
THIS EVENING. LOW CLOUDS WILL CONTINUE ACROSS MUCH OF THE
AREA...EXCEPT FAR NORTH WHERE THERE ARE SOME BREAKS IN THE LOW
CLOUDS THIS AFTERNOON. NO OTHER CHANGES WERE MADE..
UPDATED FORECAST 10 AM EST...TEMPERATURES RUNNING COOLER THAN
FORECAST SO LOWERED MAXIMUM TEMPS INTO THE UPPER 40S SOUTHWEST TO
CENTRAL AND LOWER 50S NORTHEAST...WHERE CHANCES OF PRECIPITATION
IS LESS AND CLOUD COVER THINNER. RAIN COOLED AIR AND A DRY
NORTHEAST FLOW WILL IMPEDE TEMPERATURE RISES. THE REST OF THE
FORECAST WAS LEFT UNCHANGED. PRECIPITATION FORECAST IS EXCELLENT
IN DEPICTING EXTEND AND MOVEMENT OF THE RAINFALL SHIELD WHICH
COVERS THE SOUTHERN HALF OF THE FORECAST AREA.
SHORT WAVE CAUSING THIS ACTIVITY IS NOW IN SOUTHWEST SOUTH
CAROLINA AS DEPICTED BY THE WATER VAPOR SATELLITE LOOP. RUC MODEL
TOO FAST...WENT WITH THE SLOWER NAM MODEL, CLOUDS SHOULD BEGIN
LIFTING LATER THIS AFTERNOON AND THE RAIN WILL END FROM THE
SOUTHWEST AS THE SHORT WAVE LIFTS NORTHEAST TAKING THE ISENTROPIC
LIFT WITH IT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
A BUILDING UPPER RIDGE SETS UP OVER THE FORECAST AREA TUESDAY
INTO WEDNESDAY IN RESPONSE TO A DEEP UPSTREAM TROUGH EJECTING FROM
THE DESERT SOUTHWEST. THIS WILL BRING SOME WEAK DOWNSLOPING FLOW
OFF THE MOUNTAINS AND HELP ERODE THE CLOUDS AND ALLOW FOR A
WARMING TREND THROUGH MID WEEK. TEMPERATURES SHOULD CLIMB ABOVE
NORMAL WITH HIGHS IN THE 60S AND LOWS IN THE UPPER 30S TO LOWER
40S WITH NO CHANCE FOR PRECIPITATION.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
NO LARGE CHANGES TO THE EXTENDED FORECAST. INCREASING CONFIDENCE
REGARDING THE PASSAGE OF A COLD FRONT THROUGH THE FORECAST AREA
LATE WEEK. LATEST GFS AND ECMWF BOTH SHOWING SHORTWAVE ENERGY
LIFTING THROUGH THE GREAT LAKES REGION AND DEVELOPING WESTERLY
ZONAL FLOW BEHIND THE SHORTWAVE WHICH PUSHES THE FRONT NEAR THE
FORECAST AREA ON FRIDAY AND LIKELY STALLS OR SLOWLY PUSHES THROUGH
THE REGION. DELAYED THE ONSET OF POPS TO THURSDAY NIGHT AND FRIDAY
AND GOING WITH A DRY FORECAST ON THURSDAY AND WARMER TEMPERATURES
AHEAD OF THE FRONT. TEMPERATURES FALL BACK TO NORMAL OVER THE
WEEKEND WITH THE FRONT NEARBY.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
HIGH PRESSURE WILL CONTINUE BUILDING IN ACROSS THE AREA OVER THE
NEXT 24 HOURS. SHORT WAVE WHICH BROUGHT THE RAIN IS NOW OVER
CENTRAL SOUTH CAROLINA AND MOVING EAST. MVFR CEILINGS COVER SOUTH
CAROLINA AND EAST CENTRAL GEORGIA WITH IFR CONDITIONS IN SOUTHEAST
GEORGIA. TRENDS INDICATE THAT THE CLOUDINESS IS ERODING FROM THE
NORTH AS THE HIGH BUILDS IN. MODEL GUIDANCE SHOW ONE MORE VERY
WEAK SHORT WAVE OVER THE TENNESSEE VALLEY. THIS MAY REINFORCE THE
CLOUD COVER LATER THIS AFTERNOON. THE HIGH WILL CONTINUE
STRENGTHENING AS RIDGE BUILDS INTO THE AREA FROM THE WEST TONIGHT.
WITH LOW CLOUDINESS EXTENDING ACROSS MUCH OF THE AREA THIS
AFTERNOON...KEPT MVFR CEILINGS THROUGH THE REST OF THE
DAY...FAVORING THE 17Z GFS LAMP GUIDANCE. VFR CEILINGS WILL RETURN
ACROSS THE ENTIRE AREA BETWEEN 23Z AND 00Z THIS EVENING.
WITH CLEARING SKIES LATER TONIGHT...EXPECT SOME FOG DEVELOPMENT
IN AREAS WHERE THERE WAS RAIN...AGS...OGB.
EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTED EXPECTED AT THIS
TIME.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1148 AM EST MON DEC 12 2011
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN IN CONTROL AT THE SURFACE THROUGH THE
MIDDLE OF THE WEEK. ONSHORE LOW LEVEL FLOW AND WARM ADVECTION
PROVIDE INCREASED CHANCES OF LIGHT RAIN TODAY ALONG WITH COOLER
TEMPERATURES. UPPER LEVEL RIDGING WILL BRING WARMING TEMPERATURES
MID WEEK WITH A FRONTAL BOUNDARY EXPECTED TO PUSH INTO THE REGION
LATE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
RADAR TRENDS SHOW THE BULK OF THE RAIN MOVING NORTHEAST SOUTHEAST
OF A WILLISTON TO LYNCHBURG LINE. ONLY WIDELY SCATTERED SHOWERS
ARE PRESENT ON RADAR ACROSS EAST CENTRAL GEORGIA AND CENTRAL SOUTH
CAROLINA AS THE SHORTWAVE WORKS ITS WAY ACROSS SOUTH CAROLINA. AS A
RESULT...MOVED PRECIPITATION NORTHEAST AND OUT OF THE AREA BY 00Z
THIS EVENING. LOW CLOUDS WILL CONTINUE ACROSS MUCH OF THE
AREA...EXCEPT FAR NORTH WHERE THERE ARE SOME BREAKS IN THE LOW
CLOUDS THIS AFTERNOON. NO OTHER CHANGES WERE MADE..
UPDATED FORECAST 10 AM EST...TEMPERATURES RUNNING COOLER THAN
FORECAST SO LOWERED MAXIMUM TEMPS INTO THE UPPER 40S SOUTHWEST TO
CENTRAL AND LOWER 50S NORTHEAST...WHERE CHANCES OF PRECIPITATION
IS LESS AND CLOUD COVER THINNER. RAIN COOLED AIR AND A DRY
NORTHEAST FLOW WILL IMPEDE TEMPERATURE RISES. THE REST OF THE
FORECAST WAS LEFT UNCHANGED. PRECIPITATION FORECAST IS EXCELLENT
IN DEPICTING EXTEND AND MOVEMENT OF THE RAINFALL SHIELD WHICH
COVERS THE SOUTHERN HALF OF THE FORECAST AREA.
SHORT WAVE CAUSING THIS ACTIVITY IS NOW IN SOUTHWEST SOUTH
CAROLINA AS DEPICTED BY THE WATER VAPOR SATELLITE LOOP. RUC MODEL
TOO FAST...WENT WITH THE SLOWER NAM MODEL, CLOUDS SHOULD BEGIN
LIFTING LATER THIS AFTERNOON AND THE RAIN WILL END FROM THE
SOUTHWEST AS THE SHORT WAVE LIFTS NORTHEAST TAKING THE ISENTROPIC
LIFT WITH IT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
A BUILDING UPPER RIDGE SETS UP OVER THE FORECAST AREA TUESDAY
INTO WEDNESDAY IN RESPONSE TO A DEEP UPSTREAM TROUGH EJECTING FROM
THE DESERT SOUTHWEST. THIS WILL BRING SOME WEAK DOWNSLOPING FLOW
OFF THE MOUNTAINS AND HELP ERODE THE CLOUDS AND ALLOW FOR A
WARMING TREND THROUGH MID WEEK. TEMPERATURES SHOULD CLIMB ABOVE
NORMAL WITH HIGHS IN THE 60S AND LOWS IN THE UPPER 30S TO LOWER
40S WITH NO CHANCE FOR PRECIPITATION.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
NO LARGE CHANGES TO THE EXTENDED FORECAST. INCREASING CONFIDENCE
REGARDING THE PASSAGE OF A COLD FRONT THROUGH THE FORECAST AREA
LATE WEEK. LATEST GFS AND ECMWF BOTH SHOWING SHORTWAVE ENERGY
LIFTING THROUGH THE GREAT LAKES REGION AND DEVELOPING WESTERLY
ZONAL FLOW BEHIND THE SHORTWAVE WHICH PUSHES THE FRONT NEAR THE
FORECAST AREA ON FRIDAY AND LIKELY STALLS OR SLOWLY PUSHES THROUGH
THE REGION. DELAYED THE ONSET OF POPS TO THURSDAY NIGHT AND FRIDAY
AND GOING WITH A DRY FORECAST ON THURSDAY AND WARMER TEMPERATURES
AHEAD OF THE FRONT. TEMPERATURES FALL BACK TO NORMAL OVER THE
WEEKEND WITH THE FRONT NEARBY.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
CEILINGS LIFTING OVER THE NORTHERN TERMINALS...STAYING THE SAME OR
LOWERING OVER AGS...DNL...OGB. WEAK ISENTROPIC LIFT ASSOCIATED
WITH SHORTWAVE CURRENTLY OVER WESTERN SOUTH CAROLINA WILL SHIFT
EAST BY THIS EVENING...12 Z NAM AND 06Z GFS ARE IN AGREEMENT IN ENDING
ISENTROPIC LIFT BY TONIGHT. IMPROVED CONDITIONS TO VFR AT BOTH CAE
AND CUB WITH THE BULK OF THE PRECIPITATION EXPECTED TO REMAIN
SOUTH OF THESE LOCATIONS.
LOWERED CEILING AT OGB WHERE WITH THE BEST CHANCE OF RAIN IS AND
KEPT THE FORECAST THE SAME AT AGS AND DNL. MADE MINOR CHANGES TO
THE WIND FORECAST. IN ALL LOCATIONS..HOWEVER NORTHEAST WINDS ARE EXPECTED
THROUGH THE REMAINDER OF THIS AFTERNOON. REST LEFT UNCHANGED FOR
NOW. LOW CEILINGS EXTEND BACK INTO WESTERN ALABAMA. WITH THE LACK
OF A STRONG COLD FRONT TO SCOUR OUT THE MOISTURE...MVFR TO IFR
CEILINGS MAY COME BACK ACROSS THE REGION THIS EVENING. THIS WILL
BE MORE CLOSELY LOOKED AT WITH LATER MODEL RUNS.
EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...07
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1247 PM CST MON DEC 12 2011
.DISCUSSION...
18Z TAF PACKAGE.
&&
.AVIATION...
CHALLENGING AVIATION FORECAST THIS CYCLE...WITH NEAR TERM CONCERN
THE LOW STRATUS DECK OVER THE ACADIANA TERMINALS. VISIBLE
SATELLITE IMAGERY SHOWING STEADY EROSION OF THIS CLOUD DECK...SO A
TEMPO GROUP WAS USED AT KLFT AND KARA FOR THE NEXT 1 TO 2 HOURS
RESPECTIVELY. VFR WILL PREVAIL HERE THE REST OF THE AFTERNOON INTO
THE EARLY EVENING...BUT MODEL GUIDANCE IS INDICATING A RETURN OF
LOW CLOUDS/VISIBILITY RESTRICTIONS LATER TONIGHT. WILL BRING
PREVAILING LIFR HERE AND ALSO KAEX WHERE ADVECTI0N OF THE LOWER
CLOUD DECK IS EXPECTED. MORE UNCERTAINTY EXISTS FARTHER WEST AS MID LEVEL
CLOUDS AND HIGHER BOUNDARY LAYER WINDS COME INTO PLAY. WILL LOWER
TO MVFR FOR NOW...BUT THIS MAY PROVE OPTIMISTIC IN LIGHT OF
VISIBLE SATELLITE LOOP SHOWING WESTWARD PROGRESSION OF MARINE
STRATUS ALONG THE LA COAST.
13
&&
.PREV DISCUSSION... /ISSUED 1116 AM CST MON DEC 12 2011/
UPDATE...STRATUS NOW OVER ACADIANA/EAST CENTRAL LOUISIANA HAS
STALLED ITS WESTWARD MIGRATION AND IS IN THE PROCESS OF ERODING.
RAPID WARMUP THEN EXPECTED OVER ACADIANA. BULK OF WIDESPREAD
ALTOCUMULUS OVER EAST TEXAS/NORTH LOUISIANA SHOULD REMAIN PRIMARILY
OVER THIS AREA PER LATEST RUC 850-700 MB RH. WILL MAINTAIN CURRENT
FORECAST. NO UPDATE COMING.
MARCOTTE
PREV DISCUSSION... /ISSUED 520 AM CST MON DEC 12 2011/
DISCUSSION...
12Z TAF ISSUANCE.
AVIATION...
MID LEVEL BKN/OVC DECK ~9000FT MOVING ACROSS SE TX...EXPECTED TO
GRADUALLY MOVE EAST ACROSS C AND SC LA TODAY...OTHERWISE VFR
EXPECTED THROUGH THE PERIOD. NE WINDS EXPECTED TO GRADUALLY
BECOME MORE E BY LATE AFTERNOON AND EVENING.
DML
PREV DISCUSSION... /ISSUED 438 AM CST MON DEC 12 2011/
DISCUSSION...
SFC ANALYSIS SHOWS HIGH PRESSURE CENTERED OFF THE MID-ATLANTIC
COAST CONTINUING TO RIDGE OVER THE FORECAST AREA WITH LIGHT NERLY
LOW-LEVEL LOW PREVAILING AGAIN THIS MORNING. WATER VAPOR IMAGERY
SHOWS A DECENT SHORTWAVE CROSSING THE SRN PLAINS/WRN GULF COAST
STATES WHICH HAS HELPED PRODUCED A FEW SPRINKLES OR VERY LIGHT
SHOWERS MAINLY OVER THE WRN 1/2 OF THE FORECAST AREA SO FAR
OVERNIGHT. MEANWHILE WRLY FLOW ALOFT FROM THE PACIFIC CONTINUING
TO SPREAD PLENTY OF MID/UPPER-LEVEL MOISTURE AND ASSOCIATED CLOUDINESS
OVER THE REGION. TEMPS HAVE DIPPED JUST BELOW FREEZING ACROSS THE
NERN EXTREME OF THE FORECAST AREA WHERE CLOUDS HAVE YET TO
ENCROACH AND CUT OFF THE GOOD RADIATIVE COOLING...OTHERWISE TEMPS
GENERALLY IN THE MID/UPPER 30S ALONG/EAST OF THE SABINE AND
LOWER/MID 40S OVER SERN TX.
NO SIGNIFICANT CHANGES TO THE EARLY PART OF THIS FORECAST PACKAGE.
ANOTHER DAY OF LIGHT ERLY/NERLY FLOW EXPECTED TODAY AS THE SFC
HIGH LINGERS NEAR THE ERN SEA BOARD. MEANWHILE SRLY FLOW WILL
BEGIN TO DEVELOP ALOFT AS STRONG STORM SYSTEM CRASHES ASHORE ALONG
THE SRN CALIFORNIA COAST. RISING HEIGHTS/WARMING ALOFT WILL LEAD
TO THE BEGINNINGS OF A WARMING TREND WITH MAX TEMPS TODAY
GENERALLY 10 DEGREES WARMER THAN YESTERDAY. MEANWHILE MINS TONIGHT
FORECAST TO JUMP ALL THE WAY TO THE MID/UPPER 40S...WITH LOWER 50S
COASTAL LA AND GOLDEN TRIANGLE REGION.
MOISTURE WILL CONTINUE TO INCREASE THROUGH THE EARLY PART OF THE
WEEK AS LOW-LEVEL FLOW VEERS AROUND TO THE SOUTHEAST. DEWPOINTS
WILL CLIMB TO THE 50S/LOWER 60S THROUGH TUESDAY WHICH WILL ALLOW
FOR SOME FOG DEVELOPMENT...ESPECIALLY NEAR THE COAST WITH SST
CURRENTLY RUNNING IN THE LOWER/MID 50S.
THE SYSTEM MOVING ASHORE OVER SRN CA TODAY WILL EJECT NEWD THROUGH
MID-WEEK SPAWNING SFC LOW DEVELOPMENT OVER THE LEE OF THE ROCKIES
ON WEDNESDAY. THE LOW WILL PUSH NEWD...GRADUALLY PULLING A SFC
FRONTAL BOUNDARY TOWARD THE REGION. MODELS THIS MORNING ARE IN
BETTER AGREEMENT WITH OOZING THE FRONT ACROSS THE FORECAST AREA
LATE THURSDAY/EARLY FRIDAY TIME FRAME. NOT MUCH LIFT EXPECTED
ALOFT WITH BEST ENERGY PULLING WELL NE OF THE AREA BY FROPA...
INSTABILITY FAIRLY NEGLIGIBLE AS WELL SO ATTM EXPECTING MAINLY
JUST SCATTERED SHOWERS WITH THE FRONT WITH MAYBE SOME ISOLATED
THUNDER OVER THE FAR NERN ZONES. DUE TO THE SLOW-MOVING NATURE OF
THE FRONT AND FAIRLY NON-PROGRESSIVE PATTERN ALOFT WE COULD SEE A
FEW DAYS OF LINGERING SHOWERS AND THUS HAVE KEPT SMALL POPS IN THE
FORECAST THROUGH THE WEEKEND.
MARINE...
MAINLY LIGHT FLOW EXPECTED TODAY AND TONIGHT WITH HIGH PRESSURE
REMAINING IN CONTROL. WINDS WILL BEGIN TO INCREASE GRADUALLY
STARTING TOMORROW WITH LOW PRESSURE DEVELOPING OFF THE ROCKIES
ALTHOUGH SPEEDS SHOULD REMAIN BELOW ANY FLAGS. WINDS WILL STEADILY
VEER TO A SERLY DIRECTION THROUGH MID-WEEK...BECOMING MORE SRLY ON
THURSDAY AS THE FRONT APPROACHES...THEN FINALLY SHIFT TO AN
OFFSHORE FLOW POST-FROPA FRIDAY. SPLIT THE DIFFERENCE ON SPEEDS
BEHIND THE FRONT AS THE GFS GOES SCA WITH ITS NRLY WINDS...WHILE
THE EC IS A BIT MORE SLUGGISH WITH WINDS TOPPING OUT AROUND 10
KNOTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
KLCH 48 69 59 73 / 0 10 10 10
KBPT 52 69 61 73 / 0 10 10 20
KAEX 44 69 54 74 / 0 10 10 20
KLFT 48 69 57 74 / 0 10 10 10
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1116 AM CST MON DEC 12 2011
.UPDATE...STRATUS NOW OVER ACADIANA/EAST CENTRAL LOUISIANA HAS
STALLED ITS WESTWARD MIGRATION AND IS IN THE PROCESS OF ERODING.
RAPID WARMUP THEN EXPECTED OVER ACADIANA. BULK OF WIDESPREAD
ALTOCUMULUS OVER EAST TEXAS/NORTH LOUISIANA SHOULD REMAIN PRIMARILY
OVER THIS AREA PER LATEST RUC 850-700 MB RH. WILL MAINTAIN CURRENT
FORECAST. NO UPDATE COMING.
&&
MARCOTTE
&&
.PREV DISCUSSION... /ISSUED 520 AM CST MON DEC 12 2011/
DISCUSSION...
12Z TAF ISSUANCE.
AVIATION...
MID LEVEL BKN/OVC DECK ~9000FT MOVING ACROSS SE TX...EXPECTED TO
GRADUALLY MOVE EAST ACROSS C AND SC LA TODAY...OTHERWISE VFR
EXPECTED THROUGH THE PERIOD. NE WINDS EXPECTED TO GRADUALLY
BECOME MORE E BY LATE AFTERNOON AND EVENING.
DML
PREV DISCUSSION... /ISSUED 438 AM CST MON DEC 12 2011/
DISCUSSION...
SFC ANALYSIS SHOWS HIGH PRESSURE CENTERED OFF THE MID-ATLANTIC
COAST CONTINUING TO RIDGE OVER THE FORECAST AREA WITH LIGHT NERLY
LOW-LEVEL LOW PREVAILING AGAIN THIS MORNING. WATER VAPOR IMAGERY
SHOWS A DECENT SHORTWAVE CROSSING THE SRN PLAINS/WRN GULF COAST
STATES WHICH HAS HELPED PRODUCED A FEW SPRINKLES OR VERY LIGHT
SHOWERS MAINLY OVER THE WRN 1/2 OF THE FORECAST AREA SO FAR
OVERNIGHT. MEANWHILE WRLY FLOW ALOFT FROM THE PACIFIC CONTINUING
TO SPREAD PLENTY OF MID/UPPER-LEVEL MOISTURE AND ASSOCIATED CLOUDINESS
OVER THE REGION. TEMPS HAVE DIPPED JUST BELOW FREEZING ACROSS THE
NERN EXTREME OF THE FORECAST AREA WHERE CLOUDS HAVE YET TO
ENCROACH AND CUT OFF THE GOOD RADIATIVE COOLING...OTHERWISE TEMPS
GENERALLY IN THE MID/UPPER 30S ALONG/EAST OF THE SABINE AND
LOWER/MID 40S OVER SERN TX.
NO SIGNIFICANT CHANGES TO THE EARLY PART OF THIS FORECAST PACKAGE.
ANOTHER DAY OF LIGHT ERLY/NERLY FLOW EXPECTED TODAY AS THE SFC
HIGH LINGERS NEAR THE ERN SEA BOARD. MEANWHILE SRLY FLOW WILL
BEGIN TO DEVELOP ALOFT AS STRONG STORM SYSTEM CRASHES ASHORE ALONG
THE SRN CALIFORNIA COAST. RISING HEIGHTS/WARMING ALOFT WILL LEAD
TO THE BEGINNINGS OF A WARMING TREND WITH MAX TEMPS TODAY
GENERALLY 10 DEGREES WARMER THAN YESTERDAY. MEANWHILE MINS TONIGHT
FORECAST TO JUMP ALL THE WAY TO THE MID/UPPER 40S...WITH LOWER 50S
COASTAL LA AND GOLDEN TRIANGLE REGION.
MOISTURE WILL CONTINUE TO INCREASE THROUGH THE EARLY PART OF THE
WEEK AS LOW-LEVEL FLOW VEERS AROUND TO THE SOUTHEAST. DEWPOINTS
WILL CLIMB TO THE 50S/LOWER 60S THROUGH TUESDAY WHICH WILL ALLOW
FOR SOME FOG DEVELOPMENT...ESPECIALLY NEAR THE COAST WITH SST
CURRENTLY RUNNING IN THE LOWER/MID 50S.
THE SYSTEM MOVING ASHORE OVER SRN CA TODAY WILL EJECT NEWD THROUGH
MID-WEEK SPAWNING SFC LOW DEVELOPMENT OVER THE LEE OF THE ROCKIES
ON WEDNESDAY. THE LOW WILL PUSH NEWD...GRADUALLY PULLING A SFC
FRONTAL BOUNDARY TOWARD THE REGION. MODELS THIS MORNING ARE IN
BETTER AGREEMENT WITH OOZING THE FRONT ACROSS THE FORECAST AREA
LATE THURSDAY/EARLY FRIDAY TIME FRAME. NOT MUCH LIFT EXPECTED
ALOFT WITH BEST ENERGY PULLING WELL NE OF THE AREA BY FROPA...
INSTABILITY FAIRLY NEGLIGIBLE AS WELL SO ATTM EXPECTING MAINLY
JUST SCATTERED SHOWERS WITH THE FRONT WITH MAYBE SOME ISOLATED
THUNDER OVER THE FAR NERN ZONES. DUE TO THE SLOW-MOVING NATURE OF
THE FRONT AND FAIRLY NON-PROGRESSIVE PATTERN ALOFT WE COULD SEE A
FEW DAYS OF LINGERING SHOWERS AND THUS HAVE KEPT SMALL POPS IN THE
FORECAST THROUGH THE WEEKEND.
MARINE...
MAINLY LIGHT FLOW EXPECTED TODAY AND TONIGHT WITH HIGH PRESSURE
REMAINING IN CONTROL. WINDS WILL BEGIN TO INCREASE GRADUALLY
STARTING TOMORROW WITH LOW PRESSURE DEVELOPING OFF THE ROCKIES
ALTHOUGH SPEEDS SHOULD REMAIN BELOW ANY FLAGS. WINDS WILL STEADILY
VEER TO A SERLY DIRECTION THROUGH MID-WEEK...BECOMING MORE SRLY ON
THURSDAY AS THE FRONT APPROACHES...THEN FINALLY SHIFT TO AN
OFFSHORE FLOW POST-FROPA FRIDAY. SPLIT THE DIFFERENCE ON SPEEDS
BEHIND THE FRONT AS THE GFS GOES SCA WITH ITS NRLY WINDS...WHILE
THE EC IS A BIT MORE SLUGGISH WITH WINDS TOPPING OUT AROUND 10
KNOTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
KLCH 62 48 69 59 73 / 0 0 10 10 10
KBPT 62 52 69 61 73 / 0 0 10 10 20
KAEX 61 44 69 54 74 / 0 0 10 10 20
KLFT 65 48 69 57 74 / 0 0 10 10 10
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
407 PM EST MON DEC 12 2011
.SYNOPSIS...
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A SPLIT FLOW ACRS
NAMERICA WITH SRN BRANCH SW FLOW ALF OVER THE GRT LKS BTWN RDG OVER
THE ERN CONUS AND A WRN TROF. A SHRTWV EMBEDDED IN THIS SW FLOW IS
OVER MN AND CAUSING AN AREA OF -RA OVER WI INTO SE UPR MI...WHERE
DEEPER MSTR IS PRESENT. SOME SN IS MIXING IN WITH THIS PCPN IN THE
PRESENCE OF DYNAMIC COOLING ACCOMPANYING THE SHRTWV EVEN THOUGH SFC
TEMPS ARE ABV 32. ISSUED SPS THIS AFTN TO ACCOUNT FOR PERIODS OF
HEAVY SN/SLUSHY ACCUMS IN A SWATH OVER THE CNTRL WHERE DYNAMIC
COOLING RELATED TO AREA OF H85-7 FGEN IS MOST PRONOUNCED. OTRW...
TEMPS OVER THE ENTIRE CWA ARE WELL ABV NORMAL AND IN THE 30S.
ABUNDANT LLVL MSTR WITH DWPTS ALSO IN THE 30S IN LGT SW SFC FLOW HAS
CAUSED QUITE A BIT OF LO CLD/FOG OVER THE CWA...BUT A COLD FNT TO
THE N ASSOCIATED WITH A DISTURBANCE IN THE ARCTIC BRANCH OVER CAN IS
PRESSING SLOWLY SWD INTO LK SUP. THE COLD AIR BEHIND THIS FNT IS
QUITE SHALLOW PER THE 12Z INL RAOB...BUT SFC TEMPS AT NOON FALL
QUITE SHARPLY FM ARND 35 OVER THE KEWEENAW AND AHEAD OF THE FNT TO
19 AT THUNDER BAY ONTARIO.
&&
.SHORT TERM DISCUSSION /TNGT AND TUE/...
MAIN FCST CONCERNS IN THE SHORT TERM ARE PCPN CHCS/PTYPE ASSOCIATED
WITH SHRTWV LIFTING INTO WI. FOCUS FOR LATER TNGT AND TUE SHIFTS TO
INFLUX OF COLDER/DRIER AIR FM THE N AND IMPACT ON THE WX.
TNGT...SHRTWV OVER WI AND ACCOMPANYING DYNAMICS/DEEPER MSTR ARE
PROGGED TO LIFT OUT AND EXIT THE ERN ZNS BY LATE EVNG...SO GOING
MORE WDSPRD MIXED PCPN OVER MAINLY THE SE HALF WL DIMINISH WITH MID
LVL SUBSIDENCE/DRYING OVERSPREADING THE FA. HOWEVER...INFLUX OF
SHALLOW COLD AIR FOLLOWING NW-SE PASSAGE OF SFC COLD FNT WL MAINTAIN
A SHARP LLVL INVRN AND PRESENT OVC ST/SC DECK. IN PLACES WITH
UPSLOPE WIND FLOW...OPTED TO MAINTAIN MENTION OF -DZ/-FZDZ WITH
SHALLOW MSTR WELL BLO THE DGZ AND UNDER SUBSIDENCE ALF. CONSIDERING
THE LLVL CHILL OBSVD UPSTREAM...TENDED TO GO TOWARD THE LO SIDE OF
GUIDANCE FOR TEMPS FOLLOWING THE COLD FROPA. EVEN SO...AIRMASS WL
NOT BE SUFFICIENTLY COLD TO SUPPORT LES WITH SHARP INVRN.
TUE...SHALLOW COLD WEDGE WL REMAIN IN PLACE WITH SLOWING VEERING
FLOW TO MORE ESE IN THE AFTN AS CENTER OF HI PRES IN ONTARIO DRIFTS
TO THE E. WITH COLD WEDGE GETTING A BIT MORE SHALLOW...SUSPECT
LINGERING -DZ/-FZDZ WL BE MORE TIED TO UPSLOPE FLOW OVER THE NCNTRL
WHERE THERE WL BE ADDITIONAL MOISTENING OFF LK SUP. EXPECT LTL
DIURNAL TEMP RISE WITH LINGERING LO CLD OVC.
.LONG TERM /TUES NIGHT THROUGH NEXT MONDAY/...
ACTIVE MID TERM PORTION OF THE FORECAST...WITH A LOW PRESSURE SYSTEM
MOVING THROUGH THE AREA AROUND MID WEEK AND PROVIDING A WINTRY MIX
OF PCPN.
TUES NIGHT...UPPER RIDGE AXIS WILL BE SHIFTING E OF THE CWA THROUGH
THE NIGHT. SHOULD KEEP MUCH OF THE AREA DRY...ALTHOUGH PERSISTANT
LOW CLOUDS WILL BE COVERING MUCH OF THE AREA. WITH INCREASING
ISENTROPIC ASCENT AROUND THE 280 SFC AND DRY AIR ABOVE
5KFT...WOULDN/T BE SURPRISED IF THE SWRN HALF OF THE CWA EXPERIENCES
SOME DZ/FZDZ...SO HAVE PUT THE MENTION IN FOR MUCH OF THE NIGHT.
TRANSITIONED TO A RA/SN MIX ALONG THE WI BORDER OVERNIGHT...AS THE
280-300K ISENTROPIC ASCENT BEGINS TO MOVE INTO THE AREA. WITH THE
MOISTURE EATING AWAY AT THE DRY AIR...EXPECT THE DZ/RA TO QUICKLY
TRANSITION TO MAINLY SNOW ALONG THE BORDER AS ICE BECOMES PRESENT
AND THERE IS A NEARLY ISOTHERMAL LAYER AT/BELOW 0C FROM THE SFC TO
6KFT.
WITH THE MAIN TROUGH STILL WELL TO THE SW IN THE FOUR CORNERS
REGION...WEAK SHORTWAVE ENERGY WILL BE EJECTING NE TOWARDS THE AREA
ON WED. THIS WILL PUSH A WEAK LOW PRESSURE TROUGH ACROSS THE CWA
THROUGH THE DAY. BEST CHANCES OF PCPN ARE S AND E...CLOSER TO THE
MAIN PUSH OF THE SHORTWAVE...ALONG WITH H850-700 WAA AND ISENTROPIC
ASCENT. THIS AREA OF PCPN SHOULD QUICKLY MOVE NE THROUGH THE CWA
DURING THE MORNING AND EARLY AFTN AND LEAD TO A SLIGHTLY DRIER
PERIOD OVER THE W IN THE LATE AFTN BEFORE THE NEXT WAVE AFFECTS THE
AREA. DIFFICULTY IN THE FCST COMES FROM PCPN TYPE...AS THERE COULD
BE A MIXED BAG WITH THE PASSAGE OF THE SYSTEM. SOUNDINGS CONTINUE TO
SHOW A NEARLY ISOTHERMAL 0C LAYER FROM SFC TO 7KFT FOR THE
CENTRAL/WRN PORTIONS OF THE AREA...WHICH WOULD SUPPORT SNOW IN THE
MORNING. THEN AS SRLY WINDS INCREASE THROUGH THE DAY...LLVL TEMPS
LOOK TO RISE AND LEAVE THE LOWEST 2-4KFT ABOVE FREEZING /TOWARDS
2-3C/. AT THAT SAME TIME...THE DEEP MOISTURE EXITS THE AREA AND
THERE WILL LIKELY BE LITTLE/NO ICE POTENTIAL IN THE CLOUDS...SO HAVE
WENT MAINLY RAIN...WITH JUST A MENTION OF SNOW OVER THE N. MAY END
UP BEING JUST A -RA/DZ SITUATION IN THE LATE AFTN BEFORE NEXT WAVE
ARRIVES.
MAIN SHORTWAVE FROM THE SW FLOW ARRIVES ON WED NIGHT OVER THE ERN
CWA...WHICH MODELS RESPOND TO BY INTENSIFYING THE LOW OVER THE UPPER
GREAT LAKES. AT THE SAME TIME...NRN STREAM SHORTWAVE BEGINS TO ENTER
THE NRN PLAINS AND PHASES WITH THE SRN STREAM. MODELS HAVE A
NOTORIOUSLY TOUGH TIME WITH THESE EVENTS AND IT APPEARS THAT IT
CONTINUES WITH THIS SITUATION. ISSUES APPEAR WITH THE
TIMING/STRENGTH OF THE NRN STREAM WAVE...WHICH AFFECTS
INTENSITY/TRACK OF LOW. TRENDS IN THE GFS/ECMWF OVER THE LAST DAY OR
TWO HAVE BEEN FOR A WEAKER LOW TO TRACK ACROSS THE FAR ERN CWA WITH
A WEAKER NRN STREAM WAVE. WILL FOLLOW THAT TREND FOR THE WED NIGHT
AND THURS FORECAST...WITH AN EMPHASIS ON THE HPC PREFERRED GFS.
THEREFORE...HAVE THE HIGHEST POPS /80 PLUS/ OVER THE ERN HALF OF THE
CWA WITH THE BEST FORCING/MOISTURE. EXPECT THIS TO BE MAINLY RAIN
OVER THE EAST HALF...BUT IF THE ECMWF ENDS UP BEING CORRECT THERE
COULD BE SOME MIXING LATE.
FCST IS A LITTLE MORE TRICKY OVER THE W...SINCE IT IS ON THE FRINGE
OF THE BEST DEEP MOISTURE AND FORCING. IF PCPN OCCURS...HAVE A
FEELING THAT POTENTIAL FOR ICE IN THE CLOUDS IS LIMITED. HAVE
TRENDED TOWARDS MORE OF A RA SITUATION UNTIL THE COLDER AIR ARRIVES
TOWARDS DAYBREAK THURSDAY. DEPENDING ON HOW QUICKLY TEMPS FALL
DURING THE NIGHT AND INTO THURS MORNING...COULD SEE A PERIOD OF FZDZ
BEFORE TURNING TO ALL SNOW DURING THE MORNING.
THE LOW SHOULD THEN INTENSIFY OVER QUEBEC ON THURS...AS THE
SHORTWAVES PHASE. WITH SFC HIGH OVER THE NRN PLAINS AND JUST E OF
THE CANADIAN ROCKIES...EXPECT NW WINDS AND H850 TEMPS NEAR -12C TO
LEAD TO AT LEAST SOME LES DEVELOPING. INVERSION HEIGHTS AROUND
6-8KFT GIVES A DECENT CLOUD DEPTH...BUT WITH BEST FORCING BELOW THE
DGZ WILL LIMIT SNOW GROWTH. OPTED TO BUMP POPS UP HEADING INTO THE
AFTN...AS MORE FAVORABLE CONDITIONS FOR LES ARRIVE...ESPECIALLY
SINCE THE NRN CWA SHOULD BE SEEING WRAP AROUND MID-LVL MOISTURE FROM
THE LOW. FINALLY...SHOULD BE A BREEZY DAY ON THURS...WITH GUSTS
ALONG THE ERN LK SUPERIOR SHORELINE APPROACHING 40MPH.
DAYS 4 THROUGH 7 /THURS NIGHT THROUGH NEXT MONDAY/...
OVERALL...GOOD AGREEMENT IN THE EXTENDED MODELS ON THE OVERALL
PATTERN FOR THE EXTENDED PERIOD. ON THURS NIGHT...UPPER TROUGH WILL
BE PUSHING THROUGH THE AREA AND DROPPING H850 TEMPS TOWARDS -14C.
SHOULD STILL BE SOME MID-LVL MOISTURE OVER THE E BEFORE THE MOISTURE
EXITS THE AREA ON FRI AS THE INVERSION HEIGHTS FALL TOWARDS 5KFT
WITH HIGH PRESSURE RIDGE MOVING OVER THE WRN CWA. THUS...LES
INTENSITY SHOULD HIT IT/S PEAK THURS NIGHT...AS SHOWN IN LES
PARAMETER...BEFORE DIMINISHING IN INTENSITY THROUGH FRI. ONLY MADE
MINOR TWEAKS UP TO THE POPS OVER THE EAST AND THEN BUMPED UP TO HIGH
END CHANCE AND LOW LIKELY/S OVER THE NW WIND SNOW BELTS OVER THE
WEST FOR THURS NIGHT INTO FRI...ALTHOUGH THE CHANCES WILL DIMINISH
OVER THE W IN THE AFTN. IN ADDITION...WEAK SHORTWAVE ON FRI COULD
BRING SOME MID CLOUDS.
SFC HIGH PRESSURE RIDGE WILL QUICKLY MOVE EAST OF THE AREA ON FRI
NIGHT...WITH MODELS CONSISTENT ON A SHORTWAVE MOVING THROUGH THE
UPPER MISS VALLEY ON SAT. THIS WAVE WILL LIKELY DIVE S OF THE
CWA...AND CARRY THE BEST MOISTURE AND H850-500 Q-VECTOR CONV WITH
IT. OTHER THAN LINGERING LES OVER THE NW FAVORED LOCATIONS OVER THE
E IN THE MORNING BEFORE WIND SHIFT TO THE SW...WILL KEEP THE REST OF
THE CWA DRY.
UPPER RIDGE MOVING THROUGH SUNDAY...WITH H850 TEMPS RISING TOWARDS
1-4C. SHOULD LEAD TO ANOTHER WARM SUNDAY ACROSS THE AREA...BUT MAY
NOT BE QUITE AS WARM AS YESTERDAY/S HIGHS. DID BUMP UP TEMPS FROM
THE CONSENSUS OVER THE DOWNSLOPE AREAS NEAR LK SUPERIOR INTO THE
UPPER 30S. NEXT TROUGH WILL AFFECT THE AREA SUN NIGHT INTO
MON...BRINGING ANOTHER CHANCE OF PCPN TO THE AREA. DIFFERENCES IN
HOW AMPLIFIED THE TROUGH IS...ALONG WITH MOISTURE RETURN FROM THE
GULF...SO WILL LEAVE POPS AT SLIGHT/CHANCES.
&&
.AVIATION /FOR THE 18Z TAF ISSUANCE/...
EXPECT PREDOMINANT IFR/LIFR CONDITIONS AT ALL 3 SITES THIS FCST
PERIOD WITH MOIST SW FLOW AHEAD OF A SLOW MOVING COLD FNT APRCHG FM
THE N. ALTHOUGH THE FNT WILL SINK SLOWLY S OVER THE FA LATER TDAY/
TNGT...SHALLOW INFLUX OF COLD AIR FM THE N THAT SHARPENS LLVL INVRN
WL MAINTAIN THE LO CLDS. THE BEST CHC FOR IMPROVEMENT TO MVFR WL BE
AT CMX...AS SOME LLVL DRYING BEHIND THE FNT MIGHT IMPACT THE
KEWEENAW WITH LESS OF AN UPSLOPE WIND COMPONENT AT TIMES TNGT. SOME
-FZDZ MAY IMPACT ALL 3 SITES AT TIMES WHEN THE LLVL WINDS ARE
UPSLOPE.
&&
.MARINE /FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE/...
RELATIVELY LIGHT WINDS UNDER 20 KTS WILL PERSIST INTO EARLY WED AS A
LOW PRESSURE TROUGH SLOWLY SLIDES ACROSS LK SUPERIOR. WINDS BECOME
MORE SOUTHERLY AS ANOTHER LO PRES SYSTEM DEVELOPING IN THE PLAINS
BEGINS TO LIFT TOWARD THE UPPER GREAT LAKES. SE WINDS AHEAD OF THIS
LO MAY INCREASE TO 25 KTS ESPECIALLY OVER THE E HALF ON WED. THE
MAIN HAZARD WILL BE AFTER THE LOW MOVES TOWARD QUEBEC ON THU...WHEN
NW GALES IN ITS WAKE ENHANCED BY THE ARRIVAL OF VERY COLD AIR/MIXING
WILL PREVAIL. EXPECT THESE STRONG WINDS TO DIMINISH ON FRI WITH THE
SLOW APPROACH OF HI PRES. A STRONGER WSW FLOW WILL REDEVELOP ON SAT
AFTER THIS HI SHIFTS TO THE SE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...KC
SHORT TERM...KC
LONG TERM...SRF
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1144 AM CST MON DEC 12 2011
.AVIATION... /18Z TAF ISSUANCE/
FRONTAL BOUNDARY MEANDERS FROM NEAR A KDLH-KSTC-KFSD LINE AT TAF
ISSUANCE. THE FRONT WILL DRIFT SLOWLY SE TO KMSP-KRNH THIS
AFTERNOON AND THEN TURN STATIONARY. CEILINGS ALONG THE FRONT ARE
MAINLY IFR AND THIS SHOULD PERSIST THROUGH THE TAF PERIOD. THE
OUTER FRINGES...KAXN AND KEAU...ARE A CHALLENGE WITH MVFR FORECAST
TO BECOME IFR TONIGHT. THE LIGHT WINDS AND MOIST LOW LEVEL
CONDITIONS SHOULD ALLOW FOR VISIBILITIES NEAR 1 MILE ALONG WITH
CEILINGS IN THE 200-400 FOOT RANGE TUESDAY MORNING. THE FLOW WILL
SLOWLY BECOME SOUTHEAST ON TUESDAY WITH RAIN ARRIVING LATE IN THE
DAY FOR KRWF AND KMSP. THE RAIN WILL SPREAD INTO KSTC...KRNH AND
KEAU TUESDAY EVENING. TEMPERATURES LOOK WARM ENOUGH THROUGH THE
NIGHT FOR RAIN AT THESE LOCATION. KAXN MAY BE A PROBLEM EARLY
TUESDAY EVENING WITH SOME POTENTIAL FOR FREEZING RAIN.
KMSP...CEILINGS BETWEEN 010-015 EARLY THIS AFTERNOON THEN DROPPING
BELOW 010 LATE IN THE AFTERNOON AS A FRONTAL BOUNDARY SETTLES
OVERHEAD. NOT CONFIDENT THE IFR CEILINGS WILL LIFT IN THE 24-30
HOUR PORTION OF THE TAF AND KEPT THEM IN. HOWEVER...DID ALLOW FOR
MVFR VISIBILITY TO DEVELOP LATE TUESDAY MORNING ONWARD.
&&
.DISCUSSION... /ISSUED 449 AM CST MON DEC 12 2011/
SUMMARY...STILL A CONCERN FOR SOME SLICK ROADS IN WESTERN
WISCONSIN...BUT OVERALL FREEZING DRIZZLE WILL NOT BE MUCH OF A
FACTOR THIS MORNING. MIXED PRECIPITATION IS EXPECTED TUESDAY NIGHT
THROUGH WEDNESDAY...BUT WE SHOULD SEE MOSTLY RAIN IN THE TWIN
CITIES METRO.
ALL THE AIRPORT OBSERVATIONS THIS MORNING RANGING BETWEEN 34-39
DEGREES IN MN AND WI. TEMPERATURES HAVE BEEN STEADY ALL NIGHT...SO
DON`T EXPECT MUCH OF A CHANGE THROUGHOUT THE MORNING HOURS. MADE
SOME CALLS TO COUNTIES IN WESTERN WI THIS MORNING. THERE HAVE
BEEN SOME SLICK SPOTS ON ROADS IN RUSK...PRICE...AND TAYLOR
COUNTIES THIS MORNING. EVEN WITH THE AIR TEMPERATURE ABOVE
FREEZING...ROAD PAVEMENT TEMPERATURES ARE RANGING BETWEEN 30-33
DEGREES GIVEN THE FROST IN THE GROUND. UNTREATED ROADS ARE SLICK
WHERE PRECIP IS FALLING IN WESTERN WI. SO FAR EASTERN MN HAS
REMAINED MAINLY DRIZZLE FREE AND TEMPERATURES IN MN ARE A COUPLE
DEGREES WARMER...SO THE SKIN TEMP ON THE ROADS MAY ALSO BE JUST
ABOVE FREEZING. WE`LL LET THE CURRENT FREEZING RAIN ADVISORY IN WI
RIDE FOR NOW AND THE 15Z EXPIRATION IS STILL REASONABLE AT THIS
TIME. 06-09Z RUNS OF THE HRRR HAVE BEEN HANDLING THE CURRENT LIGHT
PRECIP QUITE WELL...EVEN HIGHLIGHTING THE MORE CELLULAR NATURE TO
THE LIGHT RAIN ECHOES IN ARX`S AREA OF SOUTHWEST WI. THE HRRR DOES
SPREAD A MORE UNIFORM AREA OF LIGHT RETURNS FURTHER NORTHWEST INTO
EASTERN MN AND WESTERN WI BETWEEN 11-14Z AND LINGERS IT UNTIL THE
EARLY THIS AFTERNOON. AS A RESULT...HAVE KEPT REASONABLY HIGH POPS
AND MENTION OF DRIZZLE GOING FOR MOST OF THE DAY. THIS ALSO AGREES
WELL WITH THE SATURATION ON THE 280-295K ISENTROPIC SURFACES FROM
THE RUC AND NAM THIS MORNING.
REALLY DIDN`T CHANGE A WHOLE LOT FROM THE PREVIOUS FORECAST WITH
RESPECT TO THE MID WEEK SYSTEM. YESTERDAY`S FORECAST ALREADY
INTRODUCED 70-80% IN MANY LOCATIONS...AND HARD TO GO MUCH HIGHER
WITH THE 12.00Z ECMWF SHOWING A SLIGHTLY SLOWER TREND AND THE
LEADING WAVE OF PRECIP BRACKETING THE 12Z TIME FRAME WEDNESDAY
MORNING. IT`S BECOMING LESS LIKELY THAT WE`LL HAVE MUCH RAIN ON
THE FRONT SIDE OF THIS SYSTEM TUESDAY NIGHT INTO WEDNESDAY
MORNING. 925-850MB TEMPS JUST SEEM TO WARM TOO FAST WHEN THE
ISENTROPIC LIFT KICKS IN. 2M TEMPS ARE STILL NEAR FREEZING DURING
THIS TIME...WITH MOST OF THE GUIDANCE SHOWING 31-35 DEGREES BY
WEDNESDAY MORNING. MUCH LIKE TODAY...WITH AIR TEMPERATURES NEAR
FREEZING AND FROST IN THE GROUND...A LIGHT ICE ACCUMULATION IS
POSSIBLE ON UNTREATED SURFACES. HAVE INCLUDED A MIXTURE OF
RAIN/FREEZING RAIN IN THE FORECAST...AND EVENTUALLY TREND TOWARD
ALL RAIN BY WEDNESDAY AFTERNOON. THE ACTUALLY PV ANOMALY DOESN`T
SWING THROUGH AT THE BASE OF THE 500MB TROF UNTIL 06-12Z THURSDAY.
THE 12.00Z GFS AND ECMWF HAVE SOME SLIGHT TIMING DIFFERENCES WITH
STRENGTHENING AND PROPAGATION OF THE SURFACE REFLECTION BUT THE
OVERALL TRACK IS IN REASONABLE AGREEMENT...ALTHOUGH THE 12.06Z GFS
I SEE IS NOW COMING IN MUCH MORE AGGRESSIVE IN TERMS OF QPF. THE
06-12Z THURSDAY WINDOW IS LIKELY OUR BEST WINDOW FOR ACCUMULATING
SNOWFALL. IT ALL DEPENDS ON HOW FAST THE TEMPERATURE PROFILE
COLLAPSES AND WHERE THE DEFORMATION PRECIP SETS UP ACROSS
SOUTHEAST MN AND WESTERN WI.
OVERALL...THE MID WEEK SYSTEM AT LEAST HAS THE POTENTIAL TO BRING
THE MOST PRECIP WE`VE SEEN IN A COUPLE MONTHS...WHICH REALLY ISN`T
SAYING MUCH GIVEN HOW DRY IT`S BEEN. AFTER A FEW MORE MILD MID
DECEMBER TEMPERATURE DAYS...WE`LL GET A COOL DOWN FOR THURSDAY AND
FRIDAY...BUT HEIGHTS BUILD AGAIN FOR THE WEEKEND.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
RAH/CLF
AREA FORECAST DISCUSSION...UPDATED
NWS HASTINGS NE
1128 AM CST MON DEC 12 2011
.UPDATE...SHORT UPDATE EARLIER THIS MORNING FOR AFTERNOON WEATHER
AND LESS FOG ACROSS THE AREA. CHALLENGE THIS AFTERNOON IS THE
NORTHWEST/WEST FRINGES OF THE NEBRASKA COUNTIES WHERE SKIES CLEARED
AND TEMPERATURES TANKED...AND LOCALLY DENSE FOG HAD SET IN. HARD TO
GAGE JUST HOW MUCH WARMING THEY MAY GET WITH SNOW STILL ON THE GROUND
BUT ALSO SOME PERIODS OF SUNSHINE. ELSEWHERE...CLOUDS SKIES WILL
HOLD FORM AND TEMPERATURES IN THE 30S TO LOWER 40S. NORTHWEST WINDS
BEHIND WEAK SURFACE BOUNDARY MAY ALLOW FOR TEMPERATURES TO SLIP A FEW
DEGREES LATER THIS AFTERNOON ACROSS THE NORTHERN SECTIONS OF THE
FORECAST AREA.
THERE IS INCREASING CONTINUITY AMONGST MORNING MODEL RUNS THAT THE
PERIOD OF MAIN CONCERN FOR ICING WILL BE AFTER 08Z TONIGHT WITH
INITIAL FREEZING DRIZZLE...AND THEN FROM ABOUT 12Z TO 18Z TUESDAY
ACROSS THE NORTHWEST PART OF THE CWFA IN TERMS OF FREEZING RAIN.
THIS WILL BE THE FOCUS THIS AFTERNOON IN THE SHORT TERM.
&&
.AVIATION...MVFR TO IFR CONDITIONS WILL PREVAIL THROUGHOUT THIS
FORECAST PERIOD FOR KGRI. THE MAIN ISSUE WILL BE LATER TONIGHT
WHEN NEAR LIFR CEILINGS/VISIBILITIES WILL START TO SET UP ALONG
WITH SOME LIGHT FREEZING DRIZZLE AFTER ABOUT 08Z. EVENTUALLY THIS
WILL TURN TO MORE OF A LIGHT FREEZING RAIN SHORTLY AFTER SUNRISE
TUESDAY...BUT TEMPERATURES WILL WARM BY NOON TO HAVE RAIN START TO
BE MORE PROMINENT. WINDS WILL BE LIGHT...BUT SHIFTING TO THE NORTH
AND EVENTUALLY EAST.
&&
.PREV DISCUSSION... /ISSUED 726 AM CST MON DEC 12 2011/
AVIATION...12Z KGRI TAF. GENERALLY POOR AVIATION CONDITIONS ARE
EXPECTED AT KGRI FOR MUCH OF THE NEXT 24 HOURS. THE WIDESPREAD LOW
LEVEL STRATUS ACROSS THE REGION THIS MORNING IS EXPECTED TO
THICKEN OVER THE NEXT FEW HOURS...WITH LOW MVFR CIGS AND VSBY
LIKELY TO RETURN AND PERSIST AT KGRI THROUGH ABOUT 12/18Z.
CEILINGS AND VSBYS WILL EVENTUALLY IMPROVE TO MORE ELEVATED MVFR
LEVELS BY EARLY AFTERNOON...HOWEVER THIS MINOR IMPROVEMENT IS
EXPECTED TO BE VERY SHORT LIVED...WITH LOW MVFR...OR EVEN
IFR...VISIBILITIES AND CEILINGS EXPECTED TO DEVELOP AFTER THE SUN
SETS. IN ADDITION...AN APPROACHING SYSTEM WILL BRING THE CHANCE
FOR SOME LIGHT FREEZING DRIZZLE OR LIGHT FREEZING RAIN LATE IN THE
TAF PERIOD...BUT KEPT AS -DZ FOR CURRENT TAF ISSUANCE AS ONSET IS
VERY NEAR THE END OF CURRENT VALID PERIOD. LIGHT SOUTHERLY WINDS
NEAR 10 KTS THIS MORNING WILL SHIFT MORE WESTERLY THROUGH THE
PERIOD...EVENTUALLY TRANSITIONING FULL CIRCLE OVERNIGHT...BECOMING
NORTHEASTERLY OVERNIGHT TONIGHT.
PREV DISCUSSION... /ISSUED 556 AM CST MON DEC 12 2011/
SHORT TERM...THROUGH WEDNESDAY NIGHT. PLENTY OF ISSUES TRYING TO
NAIL DOWN PRECIP TYPES/AMOUNTS ETC. DURING THE NEXT FEW DAYS HAS
LED TO A CHALLENGING NIGHT ON THE FORECAST DESK. MAIN CONCERNS
DURING THE NEXT FEW DAYS INVOLVE WHETHER THE CWA WILL SEE ANY
APPRECIABLE RISK OF GENERALLY LIGHT ICING...ALTHOUGH GENERAL
WARMING TREND OF SURFACE TEMPERATURES DURING LAST SEVERAL MODEL
RUNS SEEMS TO BE CONFINING THE MAIN RISK ZONE TO A SMALLER AND
SMALLER AREA OF THE NORTHWEST CWA.
STARTING OFF EARLY THIS MORNING...BEEN AN INTERESTING NIGHT FROM A
TEMP PERSPECTIVE...AS WIDESPREAD STRATUS AND SOUTHERLY BREEZES
HAVE KEPT READINGS SEVERAL DEGREES ABOVE FREEZING ACROSS THE VAST
MAJORITY OF THE CWA...RESULTING IN A SOMEWHAT RARE MODEST
OVERNIGHT SNOW MELT FOR THIS TIME OF YEAR. MAIN CONCERNS
OVERNIGHT...AND THROUGH THE NEXT FEW/SEVERAL HOURS ARE ACROSS THE
FAR WESTERN PORTIONS OF THE CWA...WHERE WEB CAMS AND AUTOMATED OBS
HAVE SUGGESTED THAT THERE IS A NARROW CORRIDOR OF LOCALLY DENSE
FOG LIKELY LURKING NEAR/WITHIN WESTERN PORTIONS OF DAWSON...GOSPER
AND FURNAS COUNTIES. THIS FOG IS GENERALLY TIED TO THE EDGE OF THE
EXPANSIVE LOW CLOUD DECK COVERING MUCH OF THE REGION...ALONG WHICH
THERE IS QUITE A TEMP GRADIENT INCLUDING A STRIKING 26 DEGREE
DIFFERENCE BETWEEN HOLDREGE AND MCCOOK AT 11Z. WITH ANY DENSE FOG
SEEMINGLY AFFECTING SUCH A SMALL PORTION OF THE AREA...HAVE OPTED
AGAINST AN ADVISORY...BUT HAVE IT MENTIONED IN THE GRIDS AND ALSO
IN THE HWO. AS FOR ANY LIGHT FREEZING DRIZZLE CONCERNS FROM 12-24
HOURS AGO...THESE HAVE APPARENTLY BEEN AVOIDED FOR NOW GIVEN THE
SEASONABLY MILD OVERNIGHT TEMPS...AND EVEN PLAIN LIGHT DRIZZLE HAS
APPARENTLY BEEN QUITE SCANT OVERNIGHT ACROSS THE AREA.
A QUICK LOOK AT 11Z OBJECTIVE SURFACE ANALYSIS PLACES A WEAK
TROUGH AXIS NEAR THE EDGE OF THE STRATUS/NEAR THE WESTERN EDGE OF
THE CWA...WITH STEADY SOUTH BREEZES 5-15 MPH AFFECTING NEARLY ALL
OF THE CWA TO THE EAST OF THIS AXIS. ALOFT...WATER VAPOR IMAGERY
AND SHORT TERM MODEL DATA CONFIRM THE PRESENCE OF A FAIRLY WEAK
MID LEVEL SHORTWAVE STARTING TO DEPART EASTERN NEB TO THE EAST-
NORTHEAST...WITH LOW STRATUS CEILINGS ACTUALLY RISING QUITE A BIT
IN MUCH OF THE CWA IN ITS WAKE. UPSTREAM...THE MAIN LARGE-SCALE
TROUGH OF CONCERN IS STILL CENTERED NEAR THE PACIFIC COAST.
FOR TODAY...THE MAIN CONCERN THIS MORNING IS WHETHER ANY DENSE
FOG ALONG THE STRATUS EDGE CAN WORK A BIT FARTHER EASTWARD INTO
THE AREA. FOR NOW HAVE DENSE FOG MENTION CONFINED SOLELY TO PARTS
OF DAWSON...GOSPER...FURNAS. AS FOR SKY COVER...LATEST SUGGESTIONS
FROM HRRR MODEL IS THAT STRATUS SHOULD HOLD FIRM ACROSS MOST OF
THE CWA THROUGH THE DAY...ALTHOUGH ROUGHLY THE WESTERN 1/4 OF THE
AREA COULD SEE SOME PARTIAL CLEARING ALONG/WEST OF THE WEAK LOW
LEVEL TROUGH AXIS. DEFINITELY SOMETHING TO WATCH. TEMP
WISE...GIVEN THE WARM START RAISED HIGHS ROUGHLY 3-4 DEGREES OVER
PREVIOUS FORECAST MOST AREAS...AND POSSIBLY NOT ENOUGH. WILL AIM
FOR A GRADIENT FROM MID 30S NORTHWEST TO LOW 40S SOUTHEAST...AND
MAYBE EVEN UPPER 40S IN THE MITCHELL COUNTY KS AREA. LIMITED LIFT
SHOULD KEEP ANY POTENTIAL DRIZZLE AT BAY TODAY.
TONIGHT...MAIN CHANGE WAS TO RAISE LOW TEMPS A NOTABLE 4-8 DEGREES
OVER PREVIOUS FORECAST MOST AREAS...ALTHOUGH THIS IS VERY
DEPENDENT ON WIDESPREAD CLOUD COVER HOLDING FIRM. ASSUMING THIS
OCCURS...AM NOW TALKING A GRADIENT FROM LOW-MID 20S NORTHWEST TO
LOW-MID 30S SOUTHEAST. WITH LIGHT WINDS...CANNOT RULE OUT PATCHY
TO AREAS OF FOG OVERNIGHT...BUT NOTHING THAT CAN REALLY BE PINNED
DOWN FOR POSSIBLE DENSE DEVELOPMENT. KEPT THEME FROM PREVIOUS
FORECAST INTACT...WITH SLIGHT CHANCE OF DRIZZLE IN THE SOUTH
BEFORE MIDNIGHT...AND THEN BETTER CHANCES FOR LIGHT MEASURABLE
PRECIP AFTER MIDNIGHT MAINLY ACROSS THE SOUTHERN HALF OF THE CWA
AS FIRST LEAD SHORTWAVE MOVES INTO THE REGION. COULD SEE LIGHT
ICING MAINLY ACROSS NEB ZONES...BUT NOT ANTICIPATING MAJOR ISSUES
AND DAY SHIFT SHOULD BE ABLE TO BETTER PIN DOWN THE SURFACE TEMP
TREND.
TUESDAY...RAISED POPS 10-20 PERCENT OVER PREVIOUS FORECAST MAINLY
FOR THE AFTERNOON...WITH 60-80 POPS NOW OVER MUCH OF THE
CENTRAL/SOUTHEAST CWA. ALSO RAISED HIGHS 2-4 DEGREES MOST
AREAS...WITH ANY RISK FOR FREEZING RAIN DURING THE DAY LARGELY
CONFINED TO LOCATIONS NORTHWEST OF A GREELEY-ELWOOD LINE...AND
EVEN THIS AREA MAY BE OVERDONE IF THE ECMWF/GFS HAVE A DECENT
HANDLE ON SURFACE TEMPS. HAVE HIGHS RANGING FROM THE MID 30S
NORTHWEST TO LOW-MID 40S IN KS ZONES AND AROUND HEBRON.
TUESDAY NIGHT...FORCING FROM INCOMING MID LEVEL WAVE AND UPPER
LEVEL JET INCREASE...AND HAVE AT LEAST 50 POPS CWA-WIDE...AND
LIKELIES MAINLY ACROSS THE EASTERN 1/3. COULD EASILY SEE SLIGHTLY
RISING/AT LEAST STEADY TEMPS THROUGH THE NIGHT...WITH ANY MENTION
OF FREEZING RAIN NOW CONFINED MAINLY TO VALLEY...SHERMAN...DAWSON
COUNTIES. WITH BOTH THE NAM/GFS PULLING AT LEAST 100-300 J/KG OF
MUCAPE INTO THE CWA...AND THE SREF PROBABILITIES INCREASING FOR
GENERAL THUNDER...EVEN INTRODUCED AN ISOLATED THUNDER MENTION TO
ROUGHLY THE SOUTHEAST 1/2 OF THE CWA OVERNIGHT...WHICH MAY OR MAY
NOT EXTEND INTO WED AS WELL BUT DON/T HAVE IT IN THERE YET.
WED INTO WED NIGHT...THE MAIN MID LEVEL WAVE MOVES DIRECTLY
THROUGH THE REGION...WITH ALL PRECIP LIKELY OVER BY MIDNIGHT. HAVE
LIKELY POPS ALREADY IN PLACE ACROSS ROUGHLY THE EASTERN 1/2 OF THE
CWA ALREADY...WHICH MAY NEED EXTENDED WESTWARD IN LATER UPDATES.
UNLESS MODELS SUDDENLY START TRENDING COLDER...THIS SHOULD BE A
FAIRLY WIDESPREAD LIGHT-MODERATE RAIN EVENT...WITH ONLY THE
SMALLEST CHANCE OF FREEZING RAIN IN FAR NORTHWEST ZONES WED
MORNING. AS THE SYSTEM DEPARTS WED EVENING...CAN`T RULE OUT A VERY
BRIEF PERIOD OF SNOW OR RAIN/SNOW MIX IN THE NORTHEAST. RAISED WED
HIGHS 2-3 DEGREES ON AVERAGE...NOW RANGING FROM UPPER 30S
NORTHWEST TO LOW 50S FAR SOUTHEAST.
IN SUMMARY...MAIN CONCERN OVER NEXT FEW DAYS IS WHETHER OR NOT
FREEZING RAIN WILL AMOUNT TO ANYTHING. DESPITE RECENT WARMING
TRENDS IN MODELS...CURRENTLY HAVE 1-2 HUNDREDTHS OF ICE POTENTIAL
IN MANY AREAS...AND LOCATIONS GENERALLY NORTHWEST OF A GREELEY TO
ELWOOD LINE UP TO AROUND 5 HUNDREDTHS TOTAL. ALTHOUGH THIS WOULD
BE ENOUGH TO CAUSE AT LEAST MINOR ISSUES...CONFIDENCE IN WHETHER
IT WILL OCCUR AT ALL IS STILL LOW ENOUGH TO PRECLUDE ANYTHING
BEYOND AN HWO MENTION. BESIDES...WOULD GENERALLY PREFER TO SEE
TEMPS INTO THE 20S VERSUS LOW 30S/AROUND 30 FOR ICING TO REALLY
TAKE HOLD...AND FOR MOST OF THE NEXT FEW DAYS THIS IS NOT THE CASE
DURING ANTICIPATED TIMES OF PRECIPITATION.
LONG TERM...12Z THURSDAY THROUGH SUNDAY...A RELATIVELY QUIET
WEATHER PATTERN APPEARS TO BE IN STORE FOR THE END OF THE WORK WEEK
AS A SPLIT UPPER LEVEL FLOW PATTERN WILL RESULT IN SHORT WAVE
RIDGING ACROSS THE CENTRAL PLAINS BEHIND WEDNESDAYS DEPARTING
DISTURBANCE. UNDER THIS PATTERN...NORTHWESTERLY FLOW ALOFT WILL
CARRY MULTIPLE UPPER LEVEL DISTURBANCES ACROSS THE NORTHERN PLAINS
AS A CUT OFF LOW MEANDERS ACROSS THE DESERT SOUTHWEST...RESULTING IN
DRY AND SEASONABLE CONDITIONS LOCALLY. QUESTION WILL BE LATE IN THE
EXTENDED WHEN THE AFOREMENTIONED LOW EJECTS INTO THE PLAINS...AS THE
EC AND GFS HAVE DISTINCTLY DIFFERENT SOLUTIONS FOR EARLY NEXT
WEEK...WITH THE GFS TAKING A MUCH MORE NORTHERLY AND WETTER TRACK
LOCALLY WITH THIS LOW AND THE EC KEEPING THE SYSTEM FURTHER SOUTH.
DUE TO THE UNCERTAINTY IN TRACK AND TIMING OF THIS NEXT SYSTEM AS
WELL AS PER COORDINATION WITH SURROUNDING OFFICES...MENTIONED MAINLY
SLIGHT CHANCES FOR PRECIP LATE IN THE UPCOMING WEEKEND AS MOISTURE
ADVECTS NORTHWARD AHEAD OF THE MAIN AREA OF LOW PRESSURE...MOST
LIKELY IN THE FORM OF RAIN OR A RAIN SNOW MIX.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
1015 AM CST MON DEC 12 2011
.DISCUSSION...CLOUDS AND RESULTANT TEMPERATURES CONTINUE TO BE THE
MAIN CHALLENGE TODAY. 925MB WINDS ARE NORTHEAST WHILE SFC WINDS
ARE DUE NORTH...AND THESE WINDS SHOULD REMAIN CONSISTENT THROUGH
THE DAY. THUS...CURRENT CLOUD LOCATIONS EXPECTED TO CHANGE LITTLE
(CLEARING AREA SOMEWHERE IN THE MIDDLE OF THE FA). NOT SURE IF THE
CLEAR AREA WILL FILL IN...BUT MODEL CONVECTIVE TEMPS INTO THE 70S
SUGGEST IT WILL NOT. BASED ON EXPECTED CLOUD COVER...ADJUSTED
TEMPS FOR LITTLE RISE UNDER CLOUDS AND 5-7F RISE IN CLEAR AREA.
&&
.AVIATION...THERE STILL REMAINS A HIGH DEGREE OF UNCERTAINTY
CONCERNING CEILING FORECAST TODAY. KDVL...KBJI...KFAR ARE
IFR/MVFR WHILE KGFK AND KTVF ARE VFR. IFR/MVFR CEILINGS LIKELY TO
REMAIN IN ABOUT THE SAME LOCATION THROUGH THE AFTERNOON HOURS.
DUE TO DRY NORTHEAST LOW-LEVEL FLOW...DIFFICULT TO KNOW THE
EXTENT TO WHICH CLOUDS MAY IMPACT TAF SITES. KGFK AND KTVF SHOULD
STAY VFR THROUGH AT LEAST 18 UTC...WITH LOW CLOUDS POSSIBLY
IMPACTING THESE AIRFIELDS THIS AFTERNOON. WILL UPDATE TAFS AS
GREATER CERTAINTY IS REALIZED.
&&
.PREV DISCUSSION... /ISSUED 402 AM CST MON DEC 12 2011/
SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
PRIMARY FORECAST CHALLENGE WILL BE CLOUD COVER AND CORRESPONDING
TEMPERATURES. GFS/NAM/ECMWF/GEM MASS/THERMAL FIELDS ARE IN GOOD
AGREEMENT...BUT ONLY THE RUC AND HRRR BEST RESEMBLE CURRENT CLOUD
TRENDS. WILL FOLLOW HIGH RESOLUTION MODELS FOR THE NEAR TERM...
TRANSITIONING TO A MODEL BLEND THEREAFTER.
09 UTC SURFACE ANALYSIS SHOWS A WEAK TROUGH EXTENDING FROM SOUTH
CENTRAL SD INTO THE MN ARROWHEAD WITH LOW STRATUS ALONG AND
SOUTHEAST OF THE TROUGH AXIS. A SECOND AREA OF LOW CLOUDS IS
TRAPPED BENEATH CANADIAN HIGH PRESSURE AND EXTENDS ALONG AND
NORTHWEST OF A LINE FROM HALLOCK TO DEVILS LAKE TO BISMARCK.
BETWEEN THESE CLOUDS SKIES ARE CLEAR...BUT THE TWO CLOUD DECKS
ARE CRAWLING TOWARD EACH OTHER. RUC/HRRR SUGGEST DRY LOW-LEVEL
NORTHEAST FLOW WILL KEEP SOUTHEAST ND INTO NORTH CENTRAL MN CLOUD
FREE THROUGH AT LEAST EARLY MORNING...BUT MAY BEGIN TO FILL IN
THEREAFTER. AS A RESULT...AREAS NOT IN THE NORTHWEST OR SOUTHEAST
FORECAST AREA WILL START THE DAY SUNNY WITH A GRADUAL INCREASE IN
CLOUDS...POSSIBLY BECOMING MOSTLY CLOUDY BY LATE THIS AFTERNOON.
WILL KEEP FORECAST DRY TODAY...BUT SOME LIGHT DRIZZLE IS POSSIBLE
GIVEN VERY DRY AIR ATOP NEAR SURFACE SATURATED LAYER. AS CLOUD COVER
EXPANDS...DO NOT EXPECT MUCH MOVEMENT IN TEMPERATURES WITH A
GENERAL GRADIENT FROM THE UPPER TEENS ACROSS PORTIONS OF THE
DEVILS LAKE BASIN TO THE UPPER 20S TO NEAR 30 DEGREES ACROSS WEST
CENTRAL MN. LIGHT NORTHEAST WIND WILL BE THE RULE THROUGH THE DAY.
TUESDAY WILL BE DRY AND SLIGHTLY WARMER AS SURFACE HIGH PRESSURE
AXIS DRIFTS ACROSS THE FORECAST AREA AND LIGHT RETURN FLOW DEVELOPS.
HIGHS WILL RANGE FROM THE MID 20S TO LOWER 30S.
DID NOT CHANGE POPS MUCH WEDNESDAY AND WEDNESDAY NIGHT...KEEPING
CHANCES FOR SNOW ALONG AND EAST OF A LINE FROM LISBON TO FARGO TO
BAUDETTE. MODELS ARE NOW IN GOOD AGREEMENT SHOWING A NORTHERN STREAM
SHORT-WAVE KICK MORE POTENT ENERGY FROM SOUTHWEST CONUS CUT-OFF
LOW FARTHER SOUTH AND EAST ACROSS IA AND WI. ACCUMULATIONS...IF
ANY...SHOULD BE MINIMAL. TEMPERATURES WEDNESDAY WILL RISE INTO THE
UPPER 20S TO LOWER 30S BEFORE COOLING OFF THE LATTER HALF OF THE
WEEK.
LONG TERM...THURSDAY THROUGH SUNDAY NIGHT
THE MAIN CHALLENGE WILL CONTINUE TO BE TEMPS WITH NO STORMS IN
SIGHT. A COLD FRONT WILL USHER IN MUCH COLDER AIR ON THURSDAY ALONG
WITH BRISK/BREEZY CONDITIONS. TEMPS WILL MODERATE ABOVE NORMAL
BY NEXT WEEKEND WITH UPPER RIDGE BUILDING AND 850MB TEMPS CLIMBING
OVER 0C ONCE AGAIN.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
TG
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1239 PM EST MON DEC 12 2011
.SYNOPSIS...
HIGH PRESSURE WILL DOMINATE THE REGIONS WEATHER INTO TUESDAY. THE
HIGH WILL MOVE EAST TUESDAY NIGHT AS A WARM FRONT APPROACHES THE
AREA FROM THE SOUTHWEST. THE WARM FRONT WILL PUSH ACROSS THE
REGION ON WEDNESDAY...FOLLOWED BY A COLD FRONT WEDNESDAY NIGHT
INTO THURSDAY. TEMPERATURES WILL WARM TO ABOVE NORMAL READINGS
THROUGH THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SURFACE HIGH PRESSURE EXTENDED FROM THE NEW ENGLAND COAST
TO THE THE OHIO AND TENNESSEE VALLEYS THIS MORNING. THE HIGH IS
EXPECTED TO MOVE LITTLE TODAY. AFTER A COLD START...TEMPERATURES
WILL MODERATE UNDER ABUNDANT SUNSHINE. CIRRUS WILL INCREASE IN
COVERAGE BUT IT WILL REMAIN MOSTLY SUNNY. HIGHS WILL RANGE FROM
THE LOWER 40S NORTH TO THE UPPER 40S SOUTH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
SURFACE HIGH PRESSURE WILL REESTABLISH ITSELF OVER THE OHIO VALLEY
TONIGHT INTO TUESDAY. MEANWHILE...WEAK UPR LVL ENERGY WILL TRACK
ACROSS THE GREAT LAKES. RETURN LOW LEVEL FLOW MAY BRING SOME LOWER
CLOUDS TO OUR SE CWFA THIS EVENING/OVERNIGHT WHILE MID LVL
MOISTURE STREAMS IN FROM THE WEST. CLOUD COVER WILL PREVENT
TEMPERATURES FROM COOLING OFF TOO MUCH AND SHOULD RANGE FROM THE
MID 20S TO THE LOWER 30S. SKIES ON TUESDAY WILL RANGE FROM
PARTLY TO MOSTLY CLOUDY AS MID LVL MOISTURE CONTINUES TO ADVECT
ACROSS THE REGION FROM THE WEST. HIGHS WILL VARY FROM THE MID 40S
NORTH TO NEAR 50 SOUTH.
MODELS ARE IN GOOD AGREEMENT FOR TUESDAY NIGHT INTO WEDNESDAY.
SURFACE HIGH WILL MOVE EAST AS A WARM FRONT DEVELOPS TO OUR
SOUTHWEST. THE WARM FRONT WILL MOVE ACROSS THE AREA ON WEDNESDAY.
DEEP MOISTURE WILL INCREASE OVER THE REGION THROUGH THE PERIOD.
THIS MOISTURE WILL COINCIDE WITH A STRONG LOW LEVEL JET AND UPR
LVL DIVERGENCE FROM THE RR QUAD OF AN UPR LVL JET. THIS WILL
RESULT IN SHOWERS WITH THE HIGHEST THREAT POISED FOR THE NRN
ZONES. HAVE RAISED POPS TO CATEGORICAL ACRS NRN AREAS TUESDAY
NIGHT INTO WEDNESDAY. PCPN CHANCES WILL DIMINISH TO LOW CHANCE
SOUTH OF THE OHIO RIVER.
THE WARM FRONT WILL LIFT NORTH OF THE AREA WEDNESDAY NIGHT. THE
WARM FRONT WILL BE FOLLOWED BY A COLD FRONT WHICH WILL PUSH
SOUTHEAST ACROSS THE REGION ON THURSDAY. DEEP MOISTURE COUPLED
WITH DECENT LOW LEVEL FORCING AHEAD OF THE FRONT WILL BRING
ANOTHER ROUND OF SHOWERS. HAVE GONE WITH CATEGORICAL POPS. THE
FRONT WILL PUSH SOUTHEAST THURSDAY NIGHT AS HIGH PRESSURE BUILDS
INTO THE WESTERN GREAT LAKES. THIS WILL BRING AN END TO THE PCPN.
TEMPERATURES TUESDAY NIGHT INTO THURSDAY NIGHT WILL EXHIBIT NON
DIURNAL TRENDS AND HAVE RELIED ON A BLEND OF RAW 2 M GFS AND ECMWF
FOR THE MOST PART.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
HIGH PRESSURE WILL BUILD INTO THE AREA FOR THE WEEKEND. A WEAK
SHORT WAVE MAY DROP DOWN ACROSS THE GREAT LAKES ON SATURDAY...BUT
IT LOOKS LIKE BETTER FORCING WITH THIS WILL REMAIN OFF TO OUR
NORTH SO WILL THEREFORE MAINTAIN A DRY FORECAST THROUGH THE
REMAINDER OF THE LONG TERM PERIOD. COOLER AIR WILL FILTER IN
BEHIND THE FRONT LATE IN THE WEEK...LEADING TO A RETURN TO MORE
SEASONABLE TEMPERATURES THROUGH THE WEEKEND.
&&
.AVIATION /18Z MONDAY THROUGH FRIDAY/...
WITH HIGH PRESSURE REMAINING OVER THE REGION...VFR IS EXPECTED TO
PERSIST. BR FORMATION IS NOT LIKELY IN THIS DRY AIRMASS. MODELS
SHOW INCREASING CLOUDS...FIRST IN HIGH LEVELS TODAY...THEN IN
THE MID LEVELS TONIGHT...FOLLOWED BY A LAYER AT AROUND 5000 FT ON
TUESDAY. WINDS WILL STAY LIGHT OUT OF THE SOUTH.
OUTLOOK...NO SIGNIFICANT WEATHER EXPECTED.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HICKMAN
NEAR TERM...CONIGLIO/HICKMAN
SHORT TERM...HICKMAN
LONG TERM...HICKMAN/JGL
AVIATION...CONIGLIO
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
1225 PM CST MON DEC 12 2011
.UPDATE...
AREAS OF FOG HAVE FOR THE MOST PART LIFTED ACROSS THE TEXAS AND
OKLAHOMA PANHANDLES THIS MORNING. POSSIBLE FOR PATCHY AREAS OF LIGHT
FOG TO CONTINUE EARLY THIS AFTERNOON BUT NOT EXPECTING FOG TO BECOME
MORE WIDE SPREAD GIVEN WIND SPEEDS AROUND 10 TO 20 MPH. THUS HAVE
OPTED TO LEAVE THIS OUT OF THE FORECAST FOR THIS AFTERNOON. OTHERWISE
EXPECT ANOTHER CLOUDY AND COOL DAY WITH HIGH TEMPS MAINLY IN THE 40S
TO NEAR 50 IN THE EASTERN TEXAS AND OKLAHOMA PANHANDLES. HAVE MADE
MINOR ADJUSTMENTS TO WIND AND SKY GRIDS TO ACCOUNT FOR CURRENT
TRENDS...BUT FOR THE MOST PART THE INHERITED FORECAST LOOKS TO BE ON
TRACK WITH NO OTHER AMENDMENTS NEEDED. UPDATED FORECAST PRODUCTS
HAVE BEEN SENT.
CLK
&&
.PREV DISCUSSION... /ISSUED 1156 AM CST MON DEC 12 2011/
AVIATION...
/18 UTC TAFS/ FOG AND LOW CLOUDS REMAIN THE MAIN AVIATION FORECAST
CONCERN FOR THIS FORECAST CYCLE.
AT KAMA...HAVE SEEN VISBYS IMPROVE AS THE FOG HAS SLOWLY LIFTED.
EXPECT VISBYS TO IMPROVE TO VFR BY 19 UTC...HOWEVER WILL CONTINUE TO
SEE LIFR CIGS THROUGH THE AFTERNOON. GUSTY SOUTHWEST WINDS THIS
MORNING WILL DIMINISH BUT STILL REMAIN BETWEEN 10-15 KTS THIS
AFTERNOON. LIGHT FOG WILL DEVELOP AT THE TERMINAL /AROUND 23Z/ BUT
NOT EXPECTING VISBYS TO REALLY DETEIORATE UNTIL CLOSER TO 06Z IN
AREAS OF FOG AND DRIZZLE. SHOULD SEE VISBYS IMPROVE BY 16 UTC TUESDAY
HOWEVER STILL EXPECT IFR CONDITIONS. WINDS WILL BACK MORE TO THE
SOUTHEAST WITH SPEEDS AGAIN BETWEEN 10-15 KTS.
AT KDHT/KGUY...CONDITIONS HAVE IMPROVED TO VFR BUT EXPECT THIS TO BE
FLEETING AS AREAS OF LIGHT FOG WITH CIGS AND VISBYS DETEIORATING TO
MVFR. SIMILAR TO KAMA...EXPECT AREAS OF DRIZZLE AND FOG TO DEVELOP
AROUND 03 UTC WHICH WILL CAUSE CONDITIONS TO LOWER TO LIFR. SHOULD
SEE VISBYS AND CIGS IMPROVE TO IFR AT THE END OFF THE FORECAST
PERIOD. WINDS WILL BE LIGHTER AT KDHT/KGUY AS THE EFFECTS A 45-50 KT
LOW LEVEL JET WILL BE MORE PRONOUNCED ACROSS THE SOUTHERN TEXAS
PANHANDLE.
CLK
PREV DISCUSSION... /ISSUED 556 AM CST MON DEC 12 2011/
AVIATION...
FOR THE 12Z TAFS...GENERALLY HAVE LOW TO MODERATE CONFIDENCE AT
ALL SITES.
AT KAMA...BELIEVE IFR OR LOWER CONDITIONS WILL PREVAIL FOR AT LEAST
THE NEXT 24 HOURS AND WENT WITH A MORE PESSIMISTIC FORECAST IN
REGARDS TO CEILINGS/VISIBILITIES. CONFIDENCE IS MODERATE THAT VLIFR
CONDITIONS WILL OCCUR THROUGH 16Z...THEN SOME IMPROVEMENT 16-24Z...
BEFORE CONDITIONS DETERIORATE AFTER 00Z. HAVE MODERATE CONFIDENCE THAT
LIFR CONDITIONS OR LOWER WILL OCCUR AFTER 00Z. -DZ WILL LIKELY OCCUR
AFTER 02Z.
AT KDHT...THINK IFR CONDITIONS WILL IMPROVE TO AT LEAST MVFR IF NOT
BETTER 17-20Z. DETERIORATING CONDITIONS WILL LIKELY OCCUR AFTER
00Z. HAVE LOW CONFIDENCE FOR LIFR CONDITIONS AFTER 04Z.
AT KGUY...HAVE MODERATE CONFIDENCE THAT CONDITIONS WILL IMPROVE TO
VFR 16-20Z...BEFORE DETERIORATING AFTER 22Z...ESPECIALLY AFTER 06Z.
HAVE VERY LOW CONFIDENCE FOR LIFR CONDITIONS AFTER 11Z.
MBS
PREV DISCUSSION... /ISSUED 443 AM CST MON DEC 12 2011/
DISCUSSION...
TODAY-TONIGHT: HAVE SEEN SOME PATCHY AREAS OF FOG ACROSS THE
PANHANDLES THIS MORNING...BUT STRONGER SURFACE WINDS HAVE PRECLUDED
ANY DENSE FOG CONCERNS. EXPECT PATCHY FOG TO CONTINUE THROUGH MOST
OF THE MORNING HOURS SOUTH AND EAST OF A LINE FROM DALHART TO GUYMON.
MUCH LOWER VISIBILITIES HAVE BEEN NOTED ACROSS THE SOUTH PLAINS WHERE
SURFACE/LOW-LEVEL WINDS HAVE WEAKENED...PER KLBB VAD DATA. RUC DATA
INDICATES WINDS ACROSS THE PANHANDLES MAY ALSO WEAKEN...AND IF THIS
OCCURS...VISIBILITIES WILL LIKELY DETERIORATE. STILL NOT EXPECTING
ANY DENSE FOG ISSUES AS SURFACE WINDS SHOULD REMAIN ABOVE 10
MPH...BUT WILL MONITOR CLOSELY. WOULDN/T BE SURPRISED TO SEE SOME
DRIZZLE ACROSS THE FAR SOUTHEAST TEXAS PANHANDLE THROUGH 9 AM WHERE
FORECAST SOUNDINGS INDICATE THE LOW-LEVEL MOISTURE WILL REMAIN
AROUND 2000 FT DEEP...BUT SINCE THIS IS ON THE MARGINAL END FOR
DRIZZLE...LEFT OUT OF THE FORECAST FOR NOW. OTHERWISE...EXPECT MOST
OF THE AREA TO REMAIN GRUNGED IN WITH LOW CLOUDS FOR MOST OF THE DAY.
AS A RESULT...HIGH TEMPERATURES WILL CONTINUE TO REMAIN BELOW
SEASONAL NORMS. IT IS INTERESTING TO NOTE THAT THE AVERAGE DAILY
TEMPERATURE AT AMARILLO...BORGER...DALHART...AND GUYMON HAS NOT BEEN
ABOVE NORMAL SINCE NOVEMBER 30. AS ISENTROPIC ASCENT INCREASES THIS
EVENING AND OVERNIGHT...PRECIPITATION CHANCES WILL ALSO INCREASE. QPF
AMOUNTS WILL BE LIGHT WITH MOST LOCATIONS SEEING LESS THAN 0.10"
THROUGH SUNRISE ON TUESDAY. EXPECTING THE PRECIPITATION TYPE TO BE
ALL LIQUID AS WARM AIR ADVECTION...MOISTURE ADVECTION...AND LOW
CLOUDS SHOULD KEEP TEMPERATURES ABOVE FREEZING. ONCE AGAIN...ANOTHER
ROUND OF PATCHY FOG IS EXPECTED DEVELOP AREAWIDE...BUT THE RAIN SHOULD
KEEP THE NEAR GROUND AIR MIXED ENOUGH TO LIMIT ANY DENSE FOG
CONCERNS.
TUESDAY-TUESDAY NIGHT: PATCHY FOG MAY LINGER INTO THE LATE MORNING
HOURS ON TUESDAY. OTHERWISE...ANOTHER DREARY DAY IS EXPECTED WITH LOW
CLOUDS AND INCREASING PRECIPITATION CHANCES...ESPECIALLY AFTER NOON.
MAX TEMPS WILL ONCE AGAIN BE ON THE COOL SIDE. MET AND MAV GUIDANCE
APPEAR TOO HIGH...SO FOLLOWED RAW NAM TEMPERATURES CLOSELY. BY
TUESDAY AFTERNOON...FORECAST SOUNDINGS INDICATE SOME WEAK ELEVATED
INSTABILITY DEVELOPING ACROSS MOST OF THE PANHANDLES AS LOW-LEVEL
MOISTURE INCREASES AND MID-LEVEL LAPSE RATES STEEPEN. KEPT
THUNDERSTORMS IN THE FORECAST AND SHIFTED THEM SLIGHTLY WESTWARD.
STRONGER MOISTURE ADVECTION IS EXPECTED ACROSS MOST OF THE AREA ON
TUESDAY NIGHT....AND IN FACT...THE ECMWF...GGEM...AND GFS ALL SHOW
SURFACE DEW POINTS IN THE MID TO UPPER 50S ACROSS THE SOUTHEAST TEXAS
PANHANDLE! IT/S AMAZING TO REALIZE THAT WE STRUGGLED TO SEE DEW
POINTS THAT HIGH DURING THE SPRING AND SUMMER...BUT IT/S POSSIBLE
THEY MAY REACH THAT HIGH IN DECEMBER. REGARDLESS...AS FORCING FOR
ASCENT IMPINGES ON THE MOIST AND WEAKLY UNSTABLE AIR
MASS...PRECIPITATION AND THUNDERSTORM CHANCES WILL REALLY RAMP UP
TUESDAY EVENING AND NIGHT. WITHIN THE LAST COUPLE OF WEEKS...HAVE
NOTICED THAT THE SUBTROPICAL JET HAS HAD A CONNECTION TO THE
TROPICS...AND THIS LOOKS TO BE THE CASE AGAIN WITH THIS SYSTEM. AS A
RESULT...WON/T BE SURPRISED TO SEE RAINFALL AMOUNTS OVERACHIEVE IN
SOME LOCATIONS. REGARDING THUNDERSTORM POTENTIAL...FORECAST
SOUNDINGS ARE SHOWING UP TO 300 J/KG OF MUCAPE ALONG WITH DEEP LAYER
SHEAR AROUND 70 KT. AS A RESULT...MAY SEE A FEW STRONG STORMS PRODUCE
SMALL HAIL TUESDAY AFTERNOON THROUGH TUESDAY NIGHT. NOT EXPECTING ANY
WINTRY PRECIPITATION AS SURFACE AND LOW-LEVEL TEMPERATURES WILL
REMAIN ABOVE FREEZING.
WEDNESDAY-WEDNESDAY NIGHT: THE DRY SLOT WILL QUICKLY SWEEP ACROSS THE
FORECAST AREA DURING THE DAY. THERE MAY BE ENOUGH LINGERING LOW-
LEVEL MOISTURE ACROSS THE FAR EASTERN PANHANDLES DURING THE MORNING
FOR A CHANCE OF PRECIPITATION. KEPT THUNDERSTORMS IN THE
FORECAST...BUT FORECAST SOUNDINGS INDICATING LESS THAN 50 J/KG OF
MUCAPE. THANKS TO THE DRY SLOT...THE SUN WILL MAKE AN APPEARANCE
ACROSS THE REGION. HIGH TEMPERATURES SHOULD BE ABLE TO RISE INTO THE
50S AND POSSIBLY 60S AS STRONG DOWNSLOPING WINDS DEVELOP. SPEAKING OF
THE WINDS...EXPECT THEM TO STRENGTHEN BY LATE WEDNESDAY MORNING INTO
THE MID-AFTERNOON HOURS. FORECAST SOUNDINGS INDICATE MIXING HEIGHTS WILL
BE RELATIVELY SHALLOW AND WILL NOT BE ABLE TO TAP INTO THE HIGH
MOMENTUM MID-LEVEL AIR. NONETHELESS...FORECAST SOUNDINGS ARE SHOWING
30-35 KT FLOW AT THE TOP OF THE BOUNDARY LAYER. CONTINUED TO KEEP
WINDS BELOW ADVISORY CRITERIA...ESPECIALLY SINCE MET WINDS ARE
TRENDING LOWER. HOWEVER...IF THE GFS IS CORRECT...COULD SEE ADVISORY
LEVEL WINDS...ESPECIALLY ON THE CAPROCK. AS THE UPPER TROUGH AND
ATTENDANT SURFACE LOW MOVE INTO THE UPPER MISSISSIPPI VALLEY...A COLD
FRONT WILL PUSH SOUTHWARD ACROSS THE PANHANDLES WITH MUCH COOLER AND
DRIER AIR FILTERING INTO THE AREA. AS THE AFOREMENTIONED SYNOPTIC
FEATURES PULL AWAY FROM THE AREA...THE PRESSURE GRADIENT WILL ALSO
RELAX...ALLOWING WINDS TO QUICKLY SUBSIDE UNDER 10 MPH BY SUNRISE
THURSDAY.
THURSDAY-THURSDAY NIGHT: DRY AND SUB-SEASONAL TEMPERATURES ARE
EXPECTED AS NNE UPSLOPE WINDS PREVAIL THROUGH THE DAY. DUE TO THE
UPSLOPE WINDS...LOWERED HIGHS IN ALL AREAS. A CHILLY NIGHT IS
EXPECTED WITH LOWS IN THE 20S AND LOWER 30S.
FRIDAY-MONDAY: STILL A LOT OF UNCERTAINTIES DURING THIS TIME PERIOD.
THE DGEX AND GFS CONTINUE TO REMAIN FASTER WITH THE CUTOFF LOW THAN
THE ECMWF AND GGEM. JUST NOTICED THE NEW 06 UTC GFS HAS NOW TRENDED
SLOWER WITH THE CLOSED LOW AND IS MORE SIMILAR TO THE ECMWF AND
GGEM. EXPECT PRECIPITATION TO DEVELOP ACROSS THE SOUTHWEST TEXAS
PANHANDLE SATURDAY EVENING BEFORE SPREADING ACROSS ALL OF THE
FORECAST AREA SATURDAY NIGHT. RAIN IS LIKELY SATURDAY EVENING AND
THEN POSSIBLY MIXING WITH OR CHANGING TO SNOW SATURDAY NIGHT. SOME
INDICATIONS THAT LOW-LEVEL THERMAL PROFILES MAY BE A LITTLE WARM FOR
SNOW...BUT DUE TO THE UNCERTAINTY...KEPT A RAIN/SNOW MIX IN THE
FORECAST. BEYOND SUNDAY...CONSIDERABLE UNCERTAINTY EXISTS...BUT
FOLLOWED MORE CLOSELY TO THE ECMWF FOR NOW. IF IT DOES VERIFY...WE
COULD BE LOOKING AT MORE WINTER MISCHIEF BY EARLY NEXT WEEK. STILL
PLENTY OF TIME TO WATCH THIS SYSTEM SO STAY TUNED.
JACKSON
FIRE WEATHER...
RELATIVE HUMIDITY VALUES ARE EXPECTED TO REMAIN ABOVE 30 PERCENT
ACROSS ALL OF THE PANHANDLES FOR THE NEXT SEVEN DAYS. AS A
RESULT...NO ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED.
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
05/03
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
1158 AM CST MON DEC 12 2011
.DISCUSSION...SEE AVIATION AND SHORT TERM SECTIONS FOR UPDATES.
&&
.SHORT TERM UPDATE /THIS AFTERNOON/...NOTHING TOO EARTH-SHAKING
BUT DID TWEAK TEMPERATURES DOWN SEVERAL DEGREES ACROSS THE BOARD BASED
ON CURRENT TRENDS...AS WELL AS RUC AND NAM DATA. SOUTHEAST FLOW
JUST OFF THE DECK IS TRYING HARD TO ERODE THE CLOUD MASS NEAR THE
COAST AND HAVING MODEST SUCCESS...BUT TEMPERATURES WILL STRUGGLE
TO THE 75/76 RANGE AS PREVIOUSLY FORECAST AND HAVE DIPPED TO THE
LOWER 70S. FARTHER WEST AND NORTH...MAINLY WEST OF HIGHWAY
281...THE COLD AIR IS STILL TRAPPED AND MAY BARELY ERODE BEFORE
SUNSET. MCALLEN THROUGH WESTERN BROOKS LOOKS LIKE THE EDGE...WITH
AREAS TO THE WEST TOTALLY SOCKED IN ANOTHER DAY. THIS WILL KEEP
TEMPERATURES FROM REACHING MUCH ABOVE 60 AND HAVE LOWERED HIGHS 3
TO 5 DEGREES HERE AS WELL.
THE OTHER BIG STORY WILL BE EXPECTATION FOR DENSE FOG OVERNIGHT.
MORE IN THE AFTERNOON DISCUSSION AT AROUND 2 PM. SEE PRELIMINARY
NUMBERS BELOW FOR ADJUSTMENTS./52-BSG/
.AVIATION...SOUTHEAST FLOW TRYING TO REACH THE SURFACE HAS HELPED
PUSH BREAKS INTO THE LOWER VALLEY (KHRL/KBRO)...AND CEILINGS HAVE RESPONDED
BY LIFTING INTO VFR RANGE. WINDS DEAD CALM AT 18Z BUT SHOULD
INCREASE A HAIR FROM THE EAST OR EAST/SOUTHEAST FOR A FEW HOURS
BEFORE SETTLING BACK TO LIGHT...BUT IMPORTANT...SPEEDS OVERNIGHT.
EXPECT CEILINGS TO TUMBLE BACK TO IFR TOWARD MIDNIGHT AND
VISIBILITY TO FOLLOW AFTER MIDNIGHT...CONTINUING THROUGH MID
MORNING BEFORE RAIPDLY BREAKING WITH SOUTHEAST WINDS PICKING UP TO
NEAR 10 KNOTS...AND JUMPING MUCH HIGHER RIGHT AROUND 18Z.
LIFE IS DIFFERENT 40 TO 50 MILES TO THE WEST. KMFE REMAINS IN IFR
BUT SHOULD HESITANTLY BREAK TO THE EDGE OF MVFR BEFORE 20Z...WITH
VISIBILITY NO ISSUE THIS AFTERNOON. OVERNIGHT WILL BE ANOTHER
ISSUE. CURRENT DATA FROM THE NAM 3 HOUR FORECAST
SOUNDINGS...ALONG WITH IDEA THAT TEMPERATURE AND DEWPOINT WILL
REMAIN STEADY OR SLOWLY RISE A DEGREE OR TWO WILL SET UP HIGH
POTENTIAL FOR DENSE FOG AND LOW CEILINGS...LIFR/LIFR WITH CALM
WINDS. LOWEST CONDITIONS WILL COINCIDE WITH EARLY MORNING PREP AND
FLIGHTS...AND DELAYS ARE A GOOD BET INTO AND OUT OF MCALLEN.
HAVE ISSUED A RARE PREVAILING LIFR CEILING/VISIBILITY
FORECAST...WITH A GRADUAL LIFT THROUGH LATE MORNING AND A MORE
RAPID RISE TOWARD NOON.
FINALLY...AT ALL TERMINALS...LOW LEVEL WIND SHEAR WILL BE NOTABLE
BUT NOT ENOUGH TO ADD WITH SPEEDS HOLDING AT OR BELOW 25 KNOTS
THROUGH 12Z WITHIN THE 500 TO 2000 FOOT LAYER./52-BSG/
&&
.PREV DISCUSSION... /ISSUED 526 AM CST MON DEC 12 2011/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...CIGS HAVE FALLEN BELOW 500 FEET AT ALL LOCATIONS THIS
MORNING...WITH FOG BEGINNING TO LOWER BELOW 3 MILES. CONDITIONS
SHOULD IMPROVE AFTER SUNRISE...WITH CIGS REACHING 300 FEET BY
NOON. SOME BINOVC STILL EXPECTED LATE AFTERNOON...BUT CIGS THICKEN
BACK UP AFTER SUNSET. STILL LOOKING AT MORE FOG TONIGHT...AND HAS
GOOD CHANCE OF BEING DENSER AND STARTING EARLIER IN THE EVENING.
LIGHT WINDS WILL SHIFT SOUTHEAST AND INCREASE TO 10 TO 15 KNOTS
DURING THE AFTERNOON. WINDS WILL RETURN TO L/V AFTER SUNSET.
PREV DISCUSSION... /ISSUED 406 AM CST MON DEC 12 2011/
SHORT TERM .SHORT TERM /MONDAY THROUGH TUESDAY/...OVERCAST SKIES CONTINUE
WITH OCCASIONAL DRIZZLE AND LIGHT RAIN AS THE COASTAL TROUGH
CONTINUES TO INDUCE OVERRUNNING AREAWIDE. WEAK RIDGING ALOFT WILL
BEGIN TO HELP BREAK DOWN THE SFC TROUGH THIS AFTERNOON...BRINGING
OVERRUNNING PRECIP TO AN END. CLOUD COVER WILL REMAIN MOSTLY
OVERCAST TODAY...WITH BREAKS FINALLY STARTING TO SHOW UP LATE
AFTERNOON. LIGHT WINDS AND ABUNDANT MOISTURE WILL SET THE STAGE
FOR FOG FORMATION OVERNIGHT TONIGHT. LLVL MOISTURE AND INSTABILITY
FROM A WEAK SHORTWAVE ROTATING AROUND THE GULF RIDGE WILL BRING
ANOTHER CHANCE FOR MORE SHOWERY PRECIPITATION DURING THE DAY
TUESDAY. HAVE NUDGED POP CHANCES UP ACCORDINGLY...BUT RAINS WILL
NOT BE WIDESPREAD AS IN PREVIOUS DAYS.
TEMPERATURES WILL HAVE A BETTER CHANCE TO REACH INTO THE 60S
TODAY...WITH HIGHEST READINGS WHERE ANY BREAKS IN CLOUD COVER OCCUR.
LOWS TONIGHT WILL ONLY REACH THE LOW TO MID 60S DUE TO FURTHER
INCREASES OF LLVL MOISTURE ACROSS THE REGION. TEMPS TUESDAY REACH
FURTHER INTO THE 70S...POSSIBLY REACHING 80...WITH BETTER AMOUNTS OF
SUNSHINE.
LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...PROGRESSIVE SPLIT FLOW
PATTERN ACROSS NORTH AMERICA TO MAINTAIN AN UNSETTLED WET AND
MILD FORECAST FOR ALL OF DEEP SOUTH TEXAS AND RIO GRANDE RIVER.
THIS UN LA NINA LIKE SET UP WILL BE DIFFICULT TO TIME THE SEVERAL
SHORTWAVE TROUGHS TRACKING STEADILY FROM THE WEST COAST THROUGH
THE DESERT SOUTHWEST AND INTO THE PLAINS. BOTH GFS AND ECMWF ARE
UNCANNY SIMILAR SO FORECAST CONFIDENCE IS ABOVE AVERAGE. AS
MENTIONED BIG QUESTIONS ARISE WITH TIMING OF SHORTWAVE AND
STRENGTH OF SHORTWAVES AND THE MAIN UPPER TROUGH. DO NOT SEE ANY
SIGNIFICANT COLD AIR SURGES MAKING THIS FAR SOUTH WITH THE
NORTHERN JET REMAINING ALONG THE CANADIAN BORDER DIPPING INTO THE
MIDWEST STATES. A MORE MILD MARITIME AIRMASS WILL KEEP OUR
TEMPERATURES ABOVE NORMAL MUCH OF THE LONG TERM. MOISTURE FIELDS
LOOK MODEST THROUGH THE MIDDLE HALF OF THE WEEK WITH DEEPER
MOISTURE SEEN FOR NEXT FRIDAY AND SATURDAY SIMILAR TO WHAT WAS
EXPERIENCED THIS PASS WEEKEND.
WILL START OUT WITH A BREEZY TO WINDY WEDNESDAY AS A STORM SYSTEM
LIFTS OUT OF THE 4 CORNERS REGION. GFS SUGGEST A STRONG LOW LEVEL
JET DEVELOPING AND WITH THE FINALLY PEAKING OUT MODEST MIXING OF
THE STRONGER WINDS ARE ANTICIPATED. THIS WILL PUSH TEMPERATURES
INTO THE LOWER 80S MOST LOCATIONS. RAIN CHANCES ARE NEAR NIL.
SHOWERS RETURN TO THE FORECAST THURSDAY AS ANOTHER COASTAL TROUGH
IS PROGGED TO DEVELOP. THIS TROUGH BECOMES ENHANCED FRIDAY AND
SATURDAY AS A LARGE UPPER TROUGH DIGS INTO THE SW DESERTS. A COLD
FRONT BEGINS TO ADVANCE TOWARDS THE CWA DURING THE LATER HALF OF
THE WEEK POSSIBLE DRAPING ITSELF ACROSS THE REGION ON SATURDAY.
GRIDDS SHOW CHANCE POPS AT THIS TIME AS DOES THE MODEL GUIDANCE
THIS WILL LIKELY BECOME MORE DEFINED AS WE APPROACH NEXT WEEKEND.
TEMPERATURES TO FALL DUE TO THE INCREASE IN CLOUDS...RAIN AND
POSSIBLE COLD FRONT PASSAGE.
MARINE...
NOW THROUGH TUESDAY...BREEZY CONDITIONS IN THE VICINITY OF THE SFC
COASTAL TROUGH CONTINUE TO PRODUCE WINDS AROUND 20 KNOTS AND SEAS 6
TO 7 FEET OFFSHORE. WINDS HAVE BEGUN TO DECREASE SLOWLY AS THE
TROUGH BEGINS TO WEAKEN OFFSHORE. SMALL CRAFT ADVISORIES REMAIN FOR
THE GULF WATERS THROUGH 6AM...AND WITH SLOWLY IMPROVING CONDITIONS
EXPECTED...WILL NOT BE ANTICIPATING EXTENDING ADVISORIES FURTHER.
BREEZY CONDITIONS WILL STILL BE ABLE TO KEEP SEAS ELEVATED AT 6 TO 7
FEET TODAY...FALLING TO 4 TO 5 FEET TUESDAY AFTERNOON.
TUESDAY NIGHT THROUGH FRIDAY...AN INCREASE IN WINDS AND SEAS ARE
ANTICIPATED TUESDAY NIGHT INTO WEDNESDAY AS STORM SYSTEM TRACKS
INTO INTO THE CENTRAL PLAINS. PRESSURE GRADIENT TO TIGHTEN AS
PRESSURES LOWER COMBINING WITH BROAD HIGH PRESSURE OVER THE GULF.
SMALL CRAFT ADVISORIES ARE LIKELY. WINDS TO RELAX THURSDAY AND
FRIDAY BUT SEAS WILL BE SLOW TO SUBSIDE WITH A PERSISTENT EAST FLOW
ACROSS THE GULF PRODUCING A MODERATE LONG PERIOD SWELL. UNCERTAIN
HOW HIGH THE SWELL GETS OR HOW LOW IT MIGHT FALL BUT AT LEAST
EXERCISE CAUTION WORDING IS ANTICIPATED. RAIN CHANCES INCREASE
THURSDAY WITH EVEN HIGHER CHANCES FRIDAY AND SATURDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL 71 67 76 66 / 20 10 20 10
BROWNSVILLE 70 65 78 65 / 20 10 20 10
HARLINGEN 72 64 79 64 / 30 10 20 10
MCALLEN 66 64 82 65 / 30 10 20 10
RIO GRANDE CITY 60 59 80 62 / 40 10 20 10
SOUTH PADRE ISLAND 69 68 73 67 / 20 10 20 10
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 2 PM CST THIS AFTERNOON FOR GMZ150-
155-170-175.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WWW.WEATHER.GOV/BROWNSVILLE
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
1156 AM CST MON DEC 12 2011
.AVIATION...
/18 UTC TAFS/ FOG AND LOW CLOUDS REMAIN THE MAIN AVIATION FORECAST
CONCERN FOR THIS FORECAST CYCLE.
AT KAMA...HAVE SEEN VISBYS IMPROVE AS THE FOG HAS SLOWLY LIFTED.
EXPECT VISBYS TO IMPROVE TO VFR BY 19 UTC...HOWEVER WILL CONTINUE TO
SEE LIFR CIGS THROUGH THE AFTERNOON. GUSTY SOUTHWEST WINDS THIS
MORNING WILL DIMINISH BUT STILL REMAIN BETWEEN 10-15 KTS THIS
AFTERNOON. LIGHT FOG WILL DEVELOP AT THE TERMINAL /AROUND 23Z/ BUT
NOT EXPECTING VISBYS TO REALLY DETEIORATE UNTIL CLOSER TO 06Z IN
AREAS OF FOG AND DRIZZLE. SHOULD SEE VISBYS IMPROVE BY 16 UTC TUESDAY
HOWEVER STILL EXPECT IFR CONDITIONS. WINDS WILL BACK MORE TO THE
SOUTHEAST WITH SPEEDS AGAIN BETWEEN 10-15 KTS.
AT KDHT/KGUY...CONDITIONS HAVE IMPROVED TO VFR BUT EXPECT THIS TO BE
FLEETING AS AREAS OF LIGHT FOG WITH CIGS AND VISBYS DETEIORATING TO
MVFR. SIMILAR TO KAMA...EXPECT AREAS OF DRIZZLE AND FOG TO DEVELOP
AROUND 03 UTC WHICH WILL CAUSE CONDITIONS TO LOWER TO LIFR. SHOULD
SEE VISBYS AND CIGS IMPROVE TO IFR AT THE END OFF THE FORECAST
PERIOD. WINDS WILL BE LIGHTER AT KDHT/KGUY AS THE EFFECTS A 45-50 KT
LOW LEVEL JET WILL BE MORE PRONOUNCED ACROSS THE SOUTHERN TEXAS
PANHANDLE.
CLK
&&
.PREV DISCUSSION... /ISSUED 556 AM CST MON DEC 12 2011/
AVIATION...
FOR THE 12Z TAFS...GENERALLY HAVE LOW TO MODERATE CONFIDENCE AT
ALL SITES.
AT KAMA...BELIEVE IFR OR LOWER CONDITIONS WILL PREVAIL FOR AT LEAST
THE NEXT 24 HOURS AND WENT WITH A MORE PESSIMISTIC FORECAST IN
REGARDS TO CEILINGS/VISIBILITIES. CONFIDENCE IS MODERATE THAT VLIFR
CONDITIONS WILL OCCUR THROUGH 16Z...THEN SOME IMPROVEMENT 16-24Z...
BEFORE CONDITIONS DETERIORATE AFTER 00Z. HAVE MODERATE CONFIDENCE THAT
LIFR CONDITIONS OR LOWER WILL OCCUR AFTER 00Z. -DZ WILL LIKELY OCCUR
AFTER 02Z.
AT KDHT...THINK IFR CONDITIONS WILL IMPROVE TO AT LEAST MVFR IF NOT
BETTER 17-20Z. DETERIORATING CONDITIONS WILL LIKELY OCCUR AFTER
00Z. HAVE LOW CONFIDENCE FOR LIFR CONDITIONS AFTER 04Z.
AT KGUY...HAVE MODERATE CONFIDENCE THAT CONDITIONS WILL IMPROVE TO
VFR 16-20Z...BEFORE DETERIORATING AFTER 22Z...ESPECIALLY AFTER 06Z.
HAVE VERY LOW CONFIDENCE FOR LIFR CONDITIONS AFTER 11Z.
MBS
PREV DISCUSSION... /ISSUED 443 AM CST MON DEC 12 2011/
DISCUSSION...
TODAY-TONIGHT: HAVE SEEN SOME PATCHY AREAS OF FOG ACROSS THE
PANHANDLES THIS MORNING...BUT STRONGER SURFACE WINDS HAVE PRECLUDED
ANY DENSE FOG CONCERNS. EXPECT PATCHY FOG TO CONTINUE THROUGH MOST
OF THE MORNING HOURS SOUTH AND EAST OF A LINE FROM DALHART TO GUYMON.
MUCH LOWER VISIBILITIES HAVE BEEN NOTED ACROSS THE SOUTH PLAINS WHERE
SURFACE/LOW-LEVEL WINDS HAVE WEAKENED...PER KLBB VAD DATA. RUC DATA
INDICATES WINDS ACROSS THE PANHANDLES MAY ALSO WEAKEN...AND IF THIS
OCCURS...VISIBILITIES WILL LIKELY DETERIORATE. STILL NOT EXPECTING
ANY DENSE FOG ISSUES AS SURFACE WINDS SHOULD REMAIN ABOVE 10
MPH...BUT WILL MONITOR CLOSELY. WOULDN/T BE SURPRISED TO SEE SOME
DRIZZLE ACROSS THE FAR SOUTHEAST TEXAS PANHANDLE THROUGH 9 AM WHERE
FORECAST SOUNDINGS INDICATE THE LOW-LEVEL MOISTURE WILL REMAIN
AROUND 2000 FT DEEP...BUT SINCE THIS IS ON THE MARGINAL END FOR
DRIZZLE...LEFT OUT OF THE FORECAST FOR NOW. OTHERWISE...EXPECT MOST
OF THE AREA TO REMAIN GRUNGED IN WITH LOW CLOUDS FOR MOST OF THE DAY.
AS A RESULT...HIGH TEMPERATURES WILL CONTINUE TO REMAIN BELOW
SEASONAL NORMS. IT IS INTERESTING TO NOTE THAT THE AVERAGE DAILY
TEMPERATURE AT AMARILLO...BORGER...DALHART...AND GUYMON HAS NOT BEEN
ABOVE NORMAL SINCE NOVEMBER 30. AS ISENTROPIC ASCENT INCREASES THIS
EVENING AND OVERNIGHT...PRECIPITATION CHANCES WILL ALSO INCREASE. QPF
AMOUNTS WILL BE LIGHT WITH MOST LOCATIONS SEEING LESS THAN 0.10"
THROUGH SUNRISE ON TUESDAY. EXPECTING THE PRECIPITATION TYPE TO BE
ALL LIQUID AS WARM AIR ADVECTION...MOISTURE ADVECTION...AND LOW
CLOUDS SHOULD KEEP TEMPERATURES ABOVE FREEZING. ONCE AGAIN...ANOTHER
ROUND OF PATCHY FOG IS EXPECTED DEVELOP AREAWIDE...BUT THE RAIN SHOULD
KEEP THE NEAR GROUND AIR MIXED ENOUGH TO LIMIT ANY DENSE FOG
CONCERNS.
TUESDAY-TUESDAY NIGHT: PATCHY FOG MAY LINGER INTO THE LATE MORNING
HOURS ON TUESDAY. OTHERWISE...ANOTHER DREARY DAY IS EXPECTED WITH LOW
CLOUDS AND INCREASING PRECIPITATION CHANCES...ESPECIALLY AFTER NOON.
MAX TEMPS WILL ONCE AGAIN BE ON THE COOL SIDE. MET AND MAV GUIDANCE
APPEAR TOO HIGH...SO FOLLOWED RAW NAM TEMPERATURES CLOSELY. BY
TUESDAY AFTERNOON...FORECAST SOUNDINGS INDICATE SOME WEAK ELEVATED
INSTABILITY DEVELOPING ACROSS MOST OF THE PANHANDLES AS LOW-LEVEL
MOISTURE INCREASES AND MID-LEVEL LAPSE RATES STEEPEN. KEPT
THUNDERSTORMS IN THE FORECAST AND SHIFTED THEM SLIGHTLY WESTWARD.
STRONGER MOISTURE ADVECTION IS EXPECTED ACROSS MOST OF THE AREA ON
TUESDAY NIGHT....AND IN FACT...THE ECMWF...GGEM...AND GFS ALL SHOW
SURFACE DEW POINTS IN THE MID TO UPPER 50S ACROSS THE SOUTHEAST TEXAS
PANHANDLE! IT/S AMAZING TO REALIZE THAT WE STRUGGLED TO SEE DEW
POINTS THAT HIGH DURING THE SPRING AND SUMMER...BUT IT/S POSSIBLE
THEY MAY REACH THAT HIGH IN DECEMBER. REGARDLESS...AS FORCING FOR
ASCENT IMPINGES ON THE MOIST AND WEAKLY UNSTABLE AIR
MASS...PRECIPITATION AND THUNDERSTORM CHANCES WILL REALLY RAMP UP
TUESDAY EVENING AND NIGHT. WITHIN THE LAST COUPLE OF WEEKS...HAVE
NOTICED THAT THE SUBTROPICAL JET HAS HAD A CONNECTION TO THE
TROPICS...AND THIS LOOKS TO BE THE CASE AGAIN WITH THIS SYSTEM. AS A
RESULT...WON/T BE SURPRISED TO SEE RAINFALL AMOUNTS OVERACHIEVE IN
SOME LOCATIONS. REGARDING THUNDERSTORM POTENTIAL...FORECAST
SOUNDINGS ARE SHOWING UP TO 300 J/KG OF MUCAPE ALONG WITH DEEP LAYER
SHEAR AROUND 70 KT. AS A RESULT...MAY SEE A FEW STRONG STORMS PRODUCE
SMALL HAIL TUESDAY AFTERNOON THROUGH TUESDAY NIGHT. NOT EXPECTING ANY
WINTRY PRECIPITATION AS SURFACE AND LOW-LEVEL TEMPERATURES WILL
REMAIN ABOVE FREEZING.
WEDNESDAY-WEDNESDAY NIGHT: THE DRY SLOT WILL QUICKLY SWEEP ACROSS THE
FORECAST AREA DURING THE DAY. THERE MAY BE ENOUGH LINGERING LOW-
LEVEL MOISTURE ACROSS THE FAR EASTERN PANHANDLES DURING THE MORNING
FOR A CHANCE OF PRECIPITATION. KEPT THUNDERSTORMS IN THE
FORECAST...BUT FORECAST SOUNDINGS INDICATING LESS THAN 50 J/KG OF
MUCAPE. THANKS TO THE DRY SLOT...THE SUN WILL MAKE AN APPEARANCE
ACROSS THE REGION. HIGH TEMPERATURES SHOULD BE ABLE TO RISE INTO THE
50S AND POSSIBLY 60S AS STRONG DOWNSLOPING WINDS DEVELOP. SPEAKING OF
THE WINDS...EXPECT THEM TO STRENGTHEN BY LATE WEDNESDAY MORNING INTO
THE MID-AFTERNOON HOURS. FORECAST SOUNDINGS INDICATE MIXING HEIGHTS WILL
BE RELATIVELY SHALLOW AND WILL NOT BE ABLE TO TAP INTO THE HIGH
MOMENTUM MID-LEVEL AIR. NONETHELESS...FORECAST SOUNDINGS ARE SHOWING
30-35 KT FLOW AT THE TOP OF THE BOUNDARY LAYER. CONTINUED TO KEEP
WINDS BELOW ADVISORY CRITERIA...ESPECIALLY SINCE MET WINDS ARE
TRENDING LOWER. HOWEVER...IF THE GFS IS CORRECT...COULD SEE ADVISORY
LEVEL WINDS...ESPECIALLY ON THE CAPROCK. AS THE UPPER TROUGH AND
ATTENDANT SURFACE LOW MOVE INTO THE UPPER MISSISSIPPI VALLEY...A COLD
FRONT WILL PUSH SOUTHWARD ACROSS THE PANHANDLES WITH MUCH COOLER AND
DRIER AIR FILTERING INTO THE AREA. AS THE AFOREMENTIONED SYNOPTIC
FEATURES PULL AWAY FROM THE AREA...THE PRESSURE GRADIENT WILL ALSO
RELAX...ALLOWING WINDS TO QUICKLY SUBSIDE UNDER 10 MPH BY SUNRISE
THURSDAY.
THURSDAY-THURSDAY NIGHT: DRY AND SUB-SEASONAL TEMPERATURES ARE
EXPECTED AS NNE UPSLOPE WINDS PREVAIL THROUGH THE DAY. DUE TO THE
UPSLOPE WINDS...LOWERED HIGHS IN ALL AREAS. A CHILLY NIGHT IS
EXPECTED WITH LOWS IN THE 20S AND LOWER 30S.
FRIDAY-MONDAY: STILL A LOT OF UNCERTAINTIES DURING THIS TIME PERIOD.
THE DGEX AND GFS CONTINUE TO REMAIN FASTER WITH THE CUTOFF LOW THAN
THE ECMWF AND GGEM. JUST NOTICED THE NEW 06 UTC GFS HAS NOW TRENDED
SLOWER WITH THE CLOSED LOW AND IS MORE SIMILAR TO THE ECMWF AND
GGEM. EXPECT PRECIPITATION TO DEVELOP ACROSS THE SOUTHWEST TEXAS
PANHANDLE SATURDAY EVENING BEFORE SPREADING ACROSS ALL OF THE
FORECAST AREA SATURDAY NIGHT. RAIN IS LIKELY SATURDAY EVENING AND
THEN POSSIBLY MIXING WITH OR CHANGING TO SNOW SATURDAY NIGHT. SOME
INDICATIONS THAT LOW-LEVEL THERMAL PROFILES MAY BE A LITTLE WARM FOR
SNOW...BUT DUE TO THE UNCERTAINTY...KEPT A RAIN/SNOW MIX IN THE
FORECAST. BEYOND SUNDAY...CONSIDERABLE UNCERTAINTY EXISTS...BUT
FOLLOWED MORE CLOSELY TO THE ECMWF FOR NOW. IF IT DOES VERIFY...WE
COULD BE LOOKING AT MORE WINTER MISCHIEF BY EARLY NEXT WEEK. STILL
PLENTY OF TIME TO WATCH THIS SYSTEM SO STAY TUNED.
JACKSON
FIRE WEATHER...
RELATIVE HUMIDITY VALUES ARE EXPECTED TO REMAIN ABOVE 30 PERCENT
ACROSS ALL OF THE PANHANDLES FOR THE NEXT SEVEN DAYS. AS A
RESULT...NO ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED.
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
05/03
AREA FORECAST DISCUSSION
NWS SPOKANE WA
230 PM PST Mon Dec 12 2011
.SYNOPSIS...High pressure will be over the Inland Northwest for
through Wednesday. Expect more fog/stratus formation tonight. A
stronger and more organized Pacific storm system will arrive
Wednesday evening and Thursday with the possibility of more
substantial snow accumulations over a large area. Dry and benign
conditions will return for the beginning of the weekend.
&&
.DISCUSSION...
Tonight through Wednesday: More fog and stratus to deal with. With the
departure of the low pressure trough, high pressure has been
sinking into the region from the north and funneling down the
north/south valleys especially the Okanogan valley. This process
has helped erode and keep back the stratus that has been banked up
across the southern section of the forecast area. This area has a
well defined line - stretching from Othello to Harrington to just
south of Spokane and Coeur d`Alene to the Silver Valley. This
evening the northerly pressure gradient will weaken as high
pressure settles over the region. This will shut off the winds and
allow the area of stratus and fog to expand northward. This is
seen well by the NAM, RUC and the HRR encompassing the Spokane/
Coeur d`Alene area and the Moses Lake/Ephrata area and heading to
the northern valleys overnight and into Tuesday morning. Mixing
and winds will be weak on Tuesday giving way to little break up
the low level cloud deck. This will make temperatures tricky
depending on how clear some areas will be and for how long.
Anticipate diurnal temperature change from Lewiston to Pullman and
Ritzville. The coolest spots will be in the sheltered northern
valleys like the Methow and near Priest Lake. For Tuesday and
Tuesday night, a weak weather disturbance will ride over the upper
level ridge and spread mid and high level clouds across the Inland
Northwest. Dynamics look weak with a dry air above the boundary
layer, giving way to a slight chance of snow for the higher
elevations into the north and the Idaho Panhandle. This may
disrupt the stratus deck temporarily, but high pressure will
return again on Wednesday for more stable and dry conditions. The
air stagnation advisory will remain in effect for the region.
/rfox.
Wednesday night and Thursday...A dramatic change to the stagnant
and benign weather conditions of late will occur on Wednesday
night and Thursday. Just about all of the available model guidance
brings a noticeably stronger system through the region than the
recent feeble impulses. The ECMWF model has been most consistent
with the character of this incoming storm over the past few
days...although the GFS/Canadian/UKMET and SREF guidance have also
tenuously climbed aboard in the last 24 hours.
At this time it appears a rather vigorous and fast moving short
wave will drop through the region from northwest to southeast. the
cyclonic diffluent base dynamic region will sweep through the
northern zones and sustain a steady strength or slightly weakening
surface low pressure tracking just north of the Canadian border
and dropping into Montana by late Thursday. The close approach of
this low will drag a warm front/cold front couplet through the
northern and eastern zones late Wednesday night and Thursday
morning. For a six to 9 hour period or so a moderate Pacific
moisture feed will fuel precipitation along this frontal couplet.
Air mass characteristics will support snow in just about all
locations overnight and Thursday morning...but snow-water ratios
will likely be rather low in the lowest elevations at Lewiston and
Wenatchee. Thus...confidence is increasing for a widespread snow
event Wednesday night and Thursday. The northerly track of the
offending surface low and the relatively fast transit of the
heaviest lift region argues strongly that this will be a
significant...but generally sub-warning criteria event...perhaps
2-4 inches in the higher plateaus of the Columbia Basin and
valleys north and west of the basin. The best chance of truly
heavy snow will probably be near the Canadian border over
Northeast Washington and North Idaho closer to the actual surface
low track...and in the Panhandle Mountains where post frontal
orographic ascent will augment synoptic accumulation potential. It
is too early to pin down this potential as of yet. In any
event...Thursday morning`s commute will probably be dicey over
much of Eastern Washington and North Idaho.
This system will likely provide some relief to the recent run of
stagnant air quality...and the next conference call with air
quality officials will occur Thursday morning and the disposition
of the current Air Stagnation Advisory will be further evaluated
based on how this system manifest itself.
By late Thursday this storm is moving out of the region with
lingering snow showers in the Panhandle Mountains and probably the
Camas Prairie...While a new shot of dry continental air will push
down the Okanogan Valley and begin a new low level air mass
exchange in the Columbia Basin.
Thursday night through Saturday...Reasonable model agreement
continues this period featuring a new upper level ridge forming
over the northwest. This will lead to generally dry and quiet
conditions with a possible return to increasingly stagnant
inversion conditions once again. Where models do differ...it is
with the strength of this ridge and the potential for weak
impulses to trigger a few mountain snow showers across the north
and maybe a stray flurry in some valley locations. Otherwise it
looks like an essentially dry and cool period...but with a better
potential for overnight and early morning fog since fresh snow
cover will provide a better moisture source and enhance
overnight radiational cooling potential better than the recent
stretch of quiet weather. /Fugazzi
For Saturday night through Monday...The EC brings a quick hitting
system across the Inland Northwest Saturday night in deep
northwesterly flow. This would likely only result in light
mountain snow before the model develops the ridge of high pressure
back over the Pacific Northwest. The GFS meanwhile brings a weak
stretching system across the Inland Northwest Sunday dampening the
ridge, which allows the jet stream to shift overhead, and
subsequently allow a series of storm systems to move into the
region early next week...more typical of December. However, given
the pattern of late, I trended pops below climo and more in line
with the EC. /Neuman
&&
.AVIATION...
18Z TAFs...High pressure will continue to build into the region.
Northerly flow resulted in an erosion of fog and low clouds from
KEAT and KGEG/KSFF. But IFR/MVFR cigs and vsbys will plague KCOE,
KPUW, KLWS and KMWH through 21z with slight improvements through
00z. Surface pressure gradients and winds will become very light and
combined with high pressure, and clearing of mid and high level
clouds will lead to more widespread fog and stratus formation
especially after 6z and persisting through 18z Tuesday at most of
the TAF locations. /rfox.
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 18 29 21 32 25 33 / 0 10 10 0 60 60
Coeur d`Alene 18 30 22 33 26 33 / 0 10 10 10 70 60
Pullman 23 33 23 36 27 35 / 0 10 10 10 50 60
Lewiston 22 35 25 38 29 40 / 0 10 10 10 30 50
Colville 20 30 20 32 22 34 / 0 10 10 10 70 60
Sandpoint 18 28 22 31 24 33 / 0 10 20 10 70 70
Kellogg 20 29 22 32 25 31 / 0 10 20 20 60 70
Moses Lake 16 30 15 33 21 36 / 0 10 0 10 40 20
Wenatchee 19 29 23 32 26 36 / 0 10 0 10 60 20
Omak 13 30 18 32 21 36 / 0 10 0 10 70 30
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Air Stagnation Advisory until Noon PST Thursday for Central
Panhandle Mountains-Coeur d`Alene Area-Idaho Palouse-
Lewiston Area-Northern Panhandle.
WA...Air Stagnation Advisory until Noon PST Thursday for East Slopes
Northern Cascades-Lower Garfield and Asotin Counties-Moses
Lake Area-Northeast Mountains-Okanogan Highlands-Okanogan
Valley-Spokane Area-Upper Columbia Basin-Washington Palouse-
Waterville Plateau-Wenatchee Area.
&&
$$