Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 12/03/12
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
959 PM MST FRI NOV 30 2012
.UPDATE...
ISSUED AT 722 PM MST FRI NOV 30 2012
MOIST SHORT WAVE IS MARCHING ACROSS THE GREAT BASIN WITH THE
LEADING EDGE OF THE DEEPER CLOUD MASS JUST REACHING WRN COLORADO.
THIS SHORT WAVE CONTAINS GOOD MOISTURE BUT MOVES VERY QUICKLY.
HIGHER RESOLUTION MODELS SUCH AS THE HRRR INDICATING SOME PCPN AS
FAR SOUTH AS THE LA SAL AND THE NRN SIDE OF THE SAN JUAN
MOUNTAINS. BUT THE NRN MOUNTAINS STAND THE BEST CHANCE OF SNOW
WITH 3-5 INCH ACCUMULATION POSSIBLE ABOVE 9000 FEET. WARM AIR MASS
RESULTS IN HIGH SNOW LEVELS AND APPEARS WILL RANGE FROM 7500 TO
8000 FEET OVERNIGHT. BOOSTED VALUES IN THE POP GRIDS...PRIMARILY
OVER NW COLORADO. BY DAYBREAK...THIS SHORT WAVE WILL HAVE CROSSED
THE DIVIDE WITH A CLEARING TREND FROM THE WEST.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 317 PM MST FRI NOV 30 2012
MID AND HIGH LEVEL CLOUDS CONTINUE TO STREAM INTO THE FORECAST
AREA AS AN UPPER LEVEL LOW PRESSURE SYSTEM OFF THE PACIFIC
NORTHWEST COAST CONTINUES TO SPIN...BRINGING IN A STEADY STREAM OF
MOISTURE. 700MB WINDS ARE IN THE 35 TO 45 KT RANGE WITH AN UPPER
LEVEL JET OF 80 KTS OVERHEAD IN A SOUTHWEST TO WEST FLOW. VISIBLE
SATELLITE AND VISUAL OBSERVATIONS INDICATE MOUNTAIN WAVE CLOUDS
ALREADY FORMING OVER THE UNCOMPAHGRE PLATEAU AND ON THE LEE SIDE
OF SOME RIDGES...WHICH WOULD INDICATE A STABLE ATMOSPHERE. SOME
GUSTS ARE REACHING THE SURFACE AT CRAIG AND MEEKER WHICH HAVE BEEN
GUSTING ANYWHERE FROM 20 TO 30 KTS.
THIS IS ALL OUT AHEAD OF AN EMBEDDED DISTURBANCE THAT WILL MOVE
THROUGH THIS EVENING THROUGH SATURDAY MORNING. THE BEST DYNAMICS
LIE NORTH OF THE FORECAST AREA AS THIS DISTURBANCE TRACKS FROM
NORTHERN NEVADA THROUGH NORTHERN UTAH INTO SOUTHERN IDAHO AND
WYOMING. AREAS NORTH OF I-70 WILL PRIMARILY BE AFFECTED BY THIS
DISTURBANCE AS IT CLIPS THESE ZONES. WHEN ANALYZING TIME HEIGHTS
OVER SEVERAL POINTS ACROSS THESE AFFECTED AREAS...700MB
TEMPERATURES WERE ANYWHERE FROM -1C TO -3C WHICH WOULD PUT SNOW
LEVELS AT ABOUT 7000 TO 8000 FT. WHILE THERE IS MOISTURE AND
INSTABILITY...THE FORCING IS NOT ALL THAT STRONG AND THE SATURATED
MOISTURE LAYER IS FAIRLY SHALLOW. MUCH OF THE FORCING IS CAPPED BY
A FAIRLY STABLE LAYER OVERHEAD. WITH THAT BEING SAID...IT LOOKS
LIKE THE EASTERN UINTAS...PARK AND GORE MOUNTAINS AS WELL AS THE
ELKHEADS AND FLATTOPS WILL BE FAVORED FOR ACCUMULATING SNOWFALL IN
THE 1 TO 2 INCH RANGE WITH SOME SPOTS SEEING AS MUCH AS 3.
PRIMARILY LIGHT RAIN WILL OCCUR IN THE NORTHERN VALLEYS. THE BULK
OF THE PRECIPITATION LOOKS TO OCCUR AFTER MIDNIGHT TO AROUND
SUNRISE. THE REST OF THE FORECAST AREA WILL SEE LITTLE IF ANY
PRECIPITATION...JUST SOME INCREASED CLOUD COVER. LEANED TOWARDS
THE WARMER SIDE OF GUIDANCE TONIGHT FOR LOW TEMPERATURES DUE TO
INCREASED CLOUD COVER.
SHOWERS WILL TAPER OFF AFTER SUNRISE AND WILL BE LIMITED TO THE
HIGHER PEAKS OF THE NORTHWEST COLORADO MOUNTAINS THROUGH ABOUT
NOON AS MOISTURE AND CLOUDS WILL HUG THE TERRAIN. ALTHOUGH PRECIP
WILL COME TO AN END AND CLOUD HEIGHTS WILL RISE SATURDAY
AFTERNOON...SOME HIGH CLOUDS WILL CONTINUE TO MOVE THROUGH AS THE
UPPER LEVEL LOW FEEDS MORE MOISTURE INTO THE AREA. EVEN THOUGH
THERE WILL BE A SLIGHT COOL DOWN ON SATURDAY FROM FRIDAYS HIGHS
PARTICULARLY UP NORTH...AFTERNOON HIGH TEMPERATURES WILL STILL
REMAIN SOME 10 TO 15 DEGREES ABOVE NORMAL FOR EARLY DECEMBER.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 317 PM MST FRI NOV 30 2012
HIGH CLOUDS OUT AHEAD OF THE NEXT PACIFIC WAVE WILL BEGIN TO
SPREAD OVER THE FORECAST AREA EARLY SUNDAY...THEN THICKEN AND
LOWER DURING THE AFTERNOON. MODELS CONTINUE TO SHOW A WEAKENED
SYSTEM AS COMPARED TO WHAT WAS PROGGED SEVERAL DAYS AGO. SO IN
LIGHT OF THAT EARLIER PROMISE AND BECAUSE WE REALLY NEED THE
MOISTURE...THIS STORM IS LOOKING LIKE IT WILL BE A DISAPPOINTMENT.
THAT SAID...WINDS WILL STRENGTHEN SUNDAY AFTERNOON...AND
PRECIPITATION WILL INCREASE THROUGH THE EVENING HOURS...BOTH
FAVORING THE NORTH. I HAVE SPLIT THE EVENING GRID INTO 3 HOUR
BLOCKS TO ADDRESS THIS PRECIPITATION TREND. THERE ALSO CONTINUES
TO BE SOME MODEL TIMING DIFFERENCES. THE ASSOCIATED COLD FRONT
WILL REACH THE NORTHWEST CORNER LATE IN THE EVENING INTO THE
OVERNIGHT PERIOD...DEPENDING ON THE MODEL. THE FRONT WILL QUICKLY
WEAKEN AS IT HEADS SOUTH...MOSTLY WASHING OUT BY THE TIME IT
REACHES SAN JUAN MOUNTAINS MON MORNING. THE GFS IS THE FASTER
MODEL WITH THE NAM AND ECMWF LAGGING BY JUST A FEW HOURS. THE LOW
AMPLITUDE UPPER TROUGH AXIS FOLLOWS NOT FAR BEHIND FRONT...SO THE
BEST PRECIPITATION WILL BE FROM LATE IN THE EVENING THROUGH THE
OVERNIGHT HOURS. THE GFS SHOWS SHOWERS QUICKLY DIMINISHING BY MID
MORNING ON MON. THE EC AND NAM KEEP THINGS GOING THROUGH THE
MORNING AT LEAST...WITH MOUNTAIN SHOWERS LINGERING THROUGH THE
AFTERNOON. THINK THE GFS IS TOO FAST IN AGREEMENT WITH HPC...SO
HAVE EXTENDED BETTER POPS INTO MON. THIS STORM DOES NOT PACK MUCH
COLD AIR SO SNOW LEVELS WILL REMAIN RELATIVELY HIGH. EXPECT RAIN
TO CHANGE OVER TO SNOW ACROSS MOST OF THE NORTHERN AND HIGHER
VALLEYS. BUT PRECIPITATION IN THE OTHER VALLEYS COULD REMAIN
LIQUID...OR MIXED PHASE AT BEST. HIGHS ON MON WILL STILL BE IN THE
50S ACROSS THE SOUTHERN AND CENTRAL VALLEYS AT THE MID-LOWER
ELEVATIONS.
ONCE THE STORM HAS EXITED TO THE EAST...STORM TOTAL SNOW AMOUNTS
OVER THE MOUNTAINS SHOULD REACH A FEW INCHES...WITH THE NORTH
SEEING THE BEST ACCUMULATIONS. ADVISORY AMOUNTS MAY BE POSSIBLE
FOR THE NORTH AND CENTRAL MOUNTAINS. BUT THE SHORT DURATION AND
WARM NATURE OF THE STORM...ARE LIMITING FACTORS.
DRIER AND WARMER CONDITIONS FOLLOW TROUGH MIDWEEK. THEN ANOTHER
PACIFIC TROUGH AND COLD FRONT IS PROGGED TO PASS OVER THE REGION
WED NIGHT-THU NIGHT. THE MODELS HAVE AGAIN TRENDED WEAKER WITH
THIS SYSTEM COMPARED TO WHEN IT WAS FIRST ADVERTISED A COUPLE OF
DAYS AGO. ALSO THERE CONTINUES TO BE SOME TIMING DIFFERENCES WITH
THE GFS STILL THE FASTER MODEL. SO FAR THIS SYSTEM PACKS A COLDER
CORE THAN THE ONE ON SUN NIGHT/MON. AND IF MODELS DO NOT WEAKEN IT
TOO MUCH...THIS STORM SHOULD AGAIN BRING A ROUND OF MOUNTAIN
SNOW...WITH A CHANCE OF VALLEY RAIN AND/OR SNOW SHOWERS.
MODEL INCONSISTENCIES GROW BEYOND THIS WAVE...BUT COOLER
TEMPERATURES SHOULD FOLLOW WITH DRIER CONDITIONS ON FRIDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 959 PM MST FRI NOV 30 2012
LOWER CIGS THROUGH 15Z BUT MAINTAINING VFR FOR MOST AREAS.
MOUNTAIN AIRPORTS MAY HAVE CIGS LOWERING TO BELOW AIRPORT MINIMUMS
FOR BRIEF PERIDS FROM PASSING -SHRA/-SHSN SNOW LEVEL NEAR 075-080.
MOUNTAIN TOPS WILL BE PARTIALLY OBSCURED IN SNOW AND FOG.
EXPECT MECHANICAL TURBULENCE ACROSS THE REGION.
AFTER 15Z...IMPROVING CONDITIONS WITH LOCAL -SHSN ENDING AND
DISSIPATING CIGS. VFR EXPECTED AT ALL TAF SITES.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
UPDATE...PF
SHORT TERM...MDA
LONG TERM...EH
AVIATION...PF
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
356 PM EST SAT DEC 1 2012
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN IN PLACE THROUGH MONDAY...PROVIDING
FAIR WEATHER ALONG WITH ABOVE NORMAL TEMPERATURES. A COLD FRONT
WILL MOVE THROUGH THE REGION AROUND THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
HIGH PRESSURE OVER SOUTH CAROLINA WILL KEEP PARTLY TO MOSTLY SUNNY
SKIES AND LIGHT WINDS INTO THIS EVENING. TEMPERATURES WILL BE IN
THE LOWER 60S BY THIS EVENING. UPDATED HIGH TEMPERATURES USING THE
MODIFIED RUC13 GRIDDED DATA.
TONIGHT...USED A BLEND OF MAV/MET GUIDANCE FOR THE LOW TEMPERATURES.
MOISTURE WILL BE TRAPPED NEAR THE SURFACE UNDER A SUBSIDENCE
INVERSION AS AN UPPER RIDGE BUILDS IN ACROSS THE REGION FROM THE
WEST.
MOSTLY CLEAR SKIES EARLY THIS EVENING WILL GIVE THE AREA PATCHY FOG
TOWARD SUNDAY MORNING. THE INTENSITY OF THE FOG WILL DEPEND ON SKY
COVER...WITH INCREASED CLOUDINESS EXPECTED ACROSS THE AREA AHEAD OF
ANOTHER SHORT WAVE MOVING TOWARD OUR AREA FROM KANSAS.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY NIGHT/...
FLAT MID/UPPER LEVEL RIDGE OVER THE GULF OF MEXICO SUNDAY AMPLIFIES
OVER THE EASTERN STATES MONDAY THEN MOVES OFF THE EAST COAST TUESDAY
AS A TROUGH CROSSES THE CENTRAL U.S. SURFACE HIGH PRESSURE
EXTENDING FROM THE WESTERN ATLANTIC INTO THE SOUTHEASTERN STATES
FINALLY WEAKENS TUESDAY NIGHT AS A COLD FRONT APPROACHES FROM THE
WEST.
PRECIPITABLE WATER REMAINS BELOW ONE INCH. WARM AIR ADVECTION WILL
MAKE FOR ABOVE NORMAL TEMPS. ENSEMBLE MOS HOLD TEMPS ABOVE NORMAL
WITH CHANCE OF RAIN BELOW NORMAL. WILL CONTINUE TO FORECAST DRY
WEATHER WITH HIGHS IN THE LOW/MID 70S AND LOWS MOSTLY IN THE 40S.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
UPPER LEVEL TROUGH MOVES OFF THE EAST COAST WITH LESS AMPLIFIED
FLOW ACROSS THE CENTRAL AND EASTERN CONUS. SURFACE COLD FRONT TO
CROSS THE REGION WEDNESDAY. A LOW CHANCE OF SHOWERS STILL LOOK
REASONABLE...BUT AMOUNTS MAY BE LIMITED GIVEN WEST TO NORTHWEST H850
FLOW. MEDIUM RANGE MODELS INDICATE DRY HIGH PRESSURE OVER THE REGION
THURSDAY AND FRIDAY. ANOTHER COLD FRONT AFFECTING THE AREA SATURDAY
WITH A CHANCE OF SHOWERS. TEMPS AT OR SLIGHTLY ABOVE NORMAL.
&&
.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
AN ONSHORE FLOW HAS RESULTED IN AN INCREASE IN LOW-LEVEL MOISTURE.
THIS MOISTURE PLUS DIURNAL COOLING SHOULD CAUSE THE DEVELOPMENT OF
STRATUS AND FOG LATE TONIGHT ESPECIALLY AT AGS AND DNL WHERE
HIGHER DEW POINT TEMPERATURES HAVE ADVECTED INTO THE AREA. HEATING
AND MIXING SHOULD BRING AN IMPROVEMENT LATE SUNDAY MORNING. USED
THE GFS LAMP FOR THE TIMING.
EXTENDED AVIATION OUTLOOK...CONTINUED LOW-LEVEL MOISTURE AND
DIURNAL COOLING MAY LEAD TO AREAS OF LATE NIGHT AND EARLY MORNING
MVFR OR IFR STRATUS AND FOG THROUGH TUESDAY. RESTRICTIONS MAY
OCCUR IN SHOWERS ASSOCIATED WITH A COLD FRONT WEDNESDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
315 PM EST SAT DEC 1 2012
.SYNOPSIS...
HIGH PRESSURE WILL PREVAIL THROUGH EARLY NEXT WEEK...WHILE A
WEAK COASTAL TROUGH PERSISTS ALONG THE SOUTHEAST COAST. A COLD
FRONT WILL THEN PASS OVER THE REGION DURING THE MIDDLE OF NEXT
WEEK FOLLOWED BY COOLER HIGH PRESSURE FOR THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
MARINE OBSERVATIONS STILL SHOW INDICATIONS OF A WEAK COASTAL
TROUGH JUST OFF THE COAST...BUT IT DOES NOT LOOK AS WELL DEFINED
AS IT DID EARLIER IN THE DAY. SHOULD SEE THE COASTAL TROUGH
CONTINUE TO DAMPEN OUT SOME OVERNIGHT AS HIGH PRESSURE SHIFTS
FARTHER OFF THE NORTH CAROLINA COAST. ISOLATED SHOWER ACTIVITY HAS
BEEN PERSISTENT OFFSHORE ALONG THE WESTERN WALL OF THE GULF STREAM
FOR MUCH OF THE DAY. THE 01/12Z MODELS ARE SIMILAR TO THEIR
PREVIOUS RUNS IN BEING TOO AGGRESSIVE WITH THE COVERAGE AND
INTENSITY OF THIS ACTIVITY SO WILL ONCE AGAIN FORECAST DRY
CONDITIONS FOR THE OVERNIGHT PERIOD...ALTHOUGH THE PRIMARY SHOWER
AREA MAY DRIFT WEST INTO THE NEARSHORE WATERS LATER THIS EVENING.
THE BIG FORECAST CHALLENGE FOR TONIGHT IS TRYING TO PIN DOWN SKY
COVER AND ITS POTENTIAL IMPACTS ON THE FOG AND LOW TEMPERATURE
FORECAST. THE VARIOUS 12Z GUIDANCE IS OFFERING A NUMBER OF
POSSIBLE OUTCOMES RANGING FROM CLEAR TO CLOUDY. SUSPECT MUCH OF
THE STRATOCUMULUS SHOULD DISSIPATE AS SUNSET APPROACHES AND
INSOLATION WANES. THIS SHOULD RESULT IN MOSTLY CLEAR TO PARTLY
CLOUDY SKIES...EXCEPT POSSIBLY ALONG THE ALTAMAHA RIVER WHERE
SUBTLE ISENTROPIC LIFT SHOULD KEEP MOSTLY CLOUDY SKIES GOING
THROUGH THE EVENING HOURS. THINGS BEGIN TO CHANGE LATER THIS
EVENING AND OVERNIGHT AS ANOTHER ROUND OF WEAK ISENTROPIC LIFT
REDEVELOPS ALONG THE 295K SURFACE. WRF SIMULATED CLOUD PRODUCTS
MATCH THE LATEST RAP ISENTROPIC PROGNOSTICATIONS QUITE WELL AND
SHOW LOW/MID-LEVEL CLOUDS REFORMING ACROSS MUCH OF SOUTHEAST
GEORGIA SHORT AFTER MIDNIGHT...ARCHING BACK THROUGH THE CSRA AND
SOUTHERN MIDLANDS BY SUNRISE SUNDAY. MODIFIED THE SKY FORECAST TO
MATCH THIS IDEA...WITH MOST AREAS BECOMING PARTLY TO MOSTLY CLOUDY
LATE. LOWS WILL RANGE FROM THE MID-UPPER 40S INLAND WITH LOWER-MID
50S AT THE COAST. HOURLY TEMPERATURES WILL BE NEARLY IMPOSSIBLE TO
PIN DOWN AS FLUCTUATIONS WILL OCCUR WHERE CLOUD LAYERS FORM. IF
THIS FORECAST HOLDS...WOULD EXPECT MOST AREAS SOUTH OF THE
SAVANNAH RIVER TO SEE TEMPERATURES HOLD STEADY OR EVEN SLOWLY RISE
BETWEEN 3 AM AND SUNRISE IN RESPONSE TO THICKENING CLOUD COVER.
FOG WILL BE ANOTHER CONCERN AS DEWPOINT DEPRESSIONS DROP TO ZERO
WITHIN A DECOUPLED BOUNDARY LAYER. THERE IS A POTENTIAL FOR MORE
SIGNIFICANT FOG FORMATION EARLY SUNDAY IF CLOUDS DO NOT THICKEN UP
AS EXPECTED. WILL STICK WITH A PATCHY AREAL QUALIFIER FOR
NOW...BUT IT SHOULD BE NOTED THERE ARE SOME INDICATIONS THAT THE
FOG FORECAST MAY BE MORE SIGNIFICANT. THE EVENING SHIFT WILL
CERTAINLY MONITOR THIS AND MAKE ADJUSTMENTS AS NEEDED.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
DEEP HIGH PRESSURE WILL PERSIST OVER THE SOUTHEASTERN UNITED STATES
INTO EARLY NEXT WEEK....WHILE A COASTAL TROUGH LINGERS OFF THE SOUTH
CAROLINA AND GEORGIA COAST. A SLIGHT CHANCE OF PRECIP WILL REMAIN IN
THE FORECAST SUNDAY AFTERNOON INTO MONDAY AS THE COASTAL TROUGH
GRADUALLY SHIFTS ONSHORE. ISENTROPIC ASCENT ALONG WITH INCREASING
MOISTURE WILL ALSO PRODUCE A FAIR AMOUNT OF CLOUD COVER AS THIS
PROCESS UNFOLDS. A DRY MID/UPPER LVL ATMOSPHERE HOWEVER...WILL
LIKELY CONFINE PRECIP ACTIVITY TO COASTAL COUNTIES.
OVERALL...TEMPS WILL MODIFY EACH DAY AS MID LVL RIDGING INCREASES
AHEAD OF A TROUGH AND ASSOCIATED COLD FRONT TO OUR WEST. TEMPS WILL
LIKELY REACH 5-10 DEGREES ABOVE CLIMATOLOGY DURING THE PERIOD.
PARTLY SUNNY SKIES...SOUTH/SOUTHEAST RETURN FLOW AND 1000-850 MB
THICKNESSES FAVOR AFTERNOON HIGHS LOW/MID 70S EACH DAY. TEMPS WILL
BE WARMEST AWAY FROM THE IMMEDIATE COAST.
A DECENT AMOUNT OF RADIATIONAL COOLING IS ANTICIPATED EACH NIGHT AS
BREAKS IN CLOUD COVER OCCUR AND WINDS DECOUPLE....ESPECIALLY OVER
INLAND LOCATIONS. GIVEN A RETURN FLOW FROM THE SOUTH/SOUTHEAST...SFC
DEWPTS WILL APPROACH THE MID 50S...SETTING UP FAVORABLE CONDITIONS
FOR AT LEAST PATCHY FOG BEGINNING SUNDAY NIGHT. CHANCES OF FOG
APPEAR GREATEST MONDAY NIGHT INTO TUESDAY MORNING WHEN LOW LEVEL
MOISTURE IS ENHANCED. SHOULD TRENDS PERSIST...A DENSE FOG ADVISORY
MAY BE NEEDED OVER PORTIONS OF THE AREA.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
AN UPPER TROUGH OF LOW PRESSURE ALONG WITH A SURFACE COLD FRONT LOOK
TO AFFECT THE AREA BY THE MIDDLE OF THE WEEK BUT DEEP MOISTURE AND
STRONG FORCING IS GOING TO BE LACKING AND THUS THE PROSPECTS FOR
MUCH RAINFALL APPEAR SMALL. TEMPERATURES WILL BE ABOVE NORMAL UNTIL
THURSDAY WHEN COOLER HIGH PRESSURE WEDGES IN FROM THE NORTH. SOME
MODEL DISAGREEMENT LEADS TO LOWER CONFIDENCE FOR FRIDAY BUT
PREFERRED THE SLOWER 00Z ECMWF WHICH AGREES WITH THE 12Z GFS
ENSEMBLE WHICH INDICATES THE WEDGE HOLDING IN PLACE WITH A TROUGH OF
LOW PRESSURE DEVELOPING ACROSS THE NEARBY COASTAL WATERS.
&&
.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
MAINLY VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH THE 18Z TAF
PERIOD FOR KCHS AND KSAV. A PERSISTENT ONSHORE FLOW WILL ALLOW
SCATTERED TO BROKEN VFR STRATOCUMULUS TO PREVAIL THROUGH MUCH OF THE
AFTERNOON. OVERNIGHT...EXPECT LINGERING SCATTERED CLOUDS TO HINDER
ANY SIGNIFICANT FOG POTENTIAL. STILL...SOME PATCHY FOG COULD DEVELOP
LATE TONIGHT BUT DUE TO LIMITED COVERAGE WILL MAINTAIN VFR
VISIBILITIES AT BOTH TERMINALS. WILL HAVE TO CONTINUE TO MONITOR
CLOUD COVERAGE OVERNIGHT AS ANY POCKETS OF CLEARING COULD EASILY RESULT
IN AN INCREASE IN FOG POTENTIAL.
EXTENDED AVIATION OUTLOOK...MVFR CEILINGS AND VISIBILITIES ARE
EXPECTED DURING LATE NIGHT/EARLY MORNING HOURS INTO EARLY NEXT WEEK.
CHANCES OF IFR VSBYS ARE POSSIBLE MONDAY NIGHT INTO TUESDAY MORNING
WITH FOG.
&&
.MARINE...
TONIGHT...A SWELL TRAIN THAT WAS GENERATED BY DEEP EASTERLY WINDS
AROUND HIGH PRESSURE OVER THE NORTH ATLANTIC IS FORECAST TO BEGIN
TO IMPACT THE WATERS TONIGHT. ALTHOUGH WINDS WILL GENERALLY REMAIN
10 KT OR LESS THROUGH SUNRISE...SEAS WILL BUILD SLIGHTLY AS
EASTERLY SWELLS INCREASE. SEAS WILL INCREASE TO 3-4 FT NEARSHORE
WATERS AND 4-5 FT OFFSHORE WATERS LATER TONIGHT. WHILE A FEW 6 FT
SEAS COULD BRUSH THE FAR EASTERN FRINGES OF THE GEORGIA OFFSHORE
WATERS...WILL HOLD OFF ON HOISTING A SMALL CRAFT ADVISORY FOR THIS
AREA GIVEN THE RELATIVELY SMALL AREA THAT WOULD BE IMPACTED.
SUNDAY THROUGH THURSDAY...HIGH PRESSURE WILL DOMINANT SC WATERS OVER
THE PERIOD...KEEPING WINDS/SEAS WELL BELOW SMALL CRAFT ADVISORY
THRESHOLDS. A COASTAL TROUGH WILL LINGER ALONG THE SOUTHERN
PERIPHERY OF HIGH PRESSURE IN GEORGIA WATERS SUNDAY/MONDAY...LEADING
TO A SLIGHT CHANCE OF SHOWERS. IN GENERAL...E/NE WINDS WILL PEAK
AROUND 10 KTS WITH SEAS OF 3-5 FT...HIGHEST OVER OUTER GEORGIA
WATERS. WINDS WILL BEGIN TO VEER TO SOUTH/SOUTHEAST AS THE COASTAL
TROUGH DRIFTS ONSHORE MONDAY. A COLD FRONT WILL THEN PUSH THROUGH
THE WATERS WEDNESDAY FOLLOWED BY HIGH PRESSURE WEDGING DOWN THE
COAST FROM THE NORTH THURSDAY. A NORTHEAST WIND SURGE WILL CAUSE
DETERIORATING CONDITIONS BEHIND THE COLD FRONT THURSDAY BUT NO
HEADLINES ARE EXPECTED AT THIS TIME.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
ST/DPB/JHP
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
231 PM EST SAT DEC 1 2012
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN IN PLACE THROUGH MONDAY...PROVIDING
FAIR WEATHER ALONG WITH ABOVE NORMAL TEMPERATURES. A COLD FRONT
WILL MOVE THROUGH THE REGION AROUND THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
HIGH PRESSURE OVER SOUTH CAROLINA WILL KEEP PARTLY TO MOSTLY SUNNY
SKIES AND LIGHT WINDS INTO THIS EVENING. TEMPERATURES WILL BE IN
THE LOWER 60S BY THIS EVENING. UPDATED HIGH TEMPERATURES USING THE
MODIFIED RUC13 GRIDDED DATA.
TONIGHT...USED A BLEND OF MAV/MET GUIDANCE FOR THE LOW TEMPERATURES.
MOISTURE WILL BE TRAPPED NEAR THE SURFACE UNDER A SUBSIDENCE
INVERSION AS AN UPPER RIDGE BUILDS IN ACROSS THE REGION FROM THE
WEST.
MOSTLY CLEAR SKIES EARLY THIS EVENING WILL GIVE THE AREA PATCHY FOG
TOWARD SUNDAY MORNING. THE INTENSITY OF THE FOG WILL DEPEND ON SKY
COVER...WITH INCREASED CLOUDINESS EXPECTED ACROSS THE AREA AHEAD OF
ANOTHER SHORT WAVE MOVING TOWARD OUR AREA FROM KANSAS.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/...
FLAT MID/UPPER LEVEL RIDGE OVER THE GULF OF MEXICO SUNDAY AMPLIFIES
OVER THE EASTERN STATES MONDAY THEN MOVES OFF THE EAST COAST TUESDAY
AS A TROUGH CROSSES THE CENTRAL U.S. SURFACE HIGH PRESSURE
EXTENDING FROM THE WESTERN ATLANTIC INTO THE SOUTHEASTERN STATES
FINALLY WEAKENS TUESDAY NIGHT AS A COLD FRONT APPROACHES FROM THE
WEST.
PRECIPITABLE WATER REMAINS BELOW ONE INCH. WARM AIR ADVECTION WILL
MAKE FOR ABOVE NORMAL TEMPS. ENSEMBLE MOS HOLD TEMPS ABOVE NORMAL
WITH CHANCE OF RAIN BELOW NORMAL. WILL CONTINUE TO FORECAST DRY
WEATHER WITH HIGHS IN THE LOW/MID 70S AND LOWS MOSTLY IN THE 40S.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
UPPER LEVEL TROUGH MOVES OFF THE EAST COAST WITH LESS AMPLIFIED
FLOW ACROSS THE CENTRAL AND EASTERN CONUS. SURFACE COLD FRONT TO
CROSS THE REGION WEDNESDAY. A LOW CHANCE OF SHOWERS STILL LOOK
REASONABLE...BUT AMOUNTS MAY BE LIMITED GIVEN WEST TO NORTHWEST H850
FLOW. MEDIUM RANGE MODELS INDICATE DRY HIGH PRESSURE OVER THE REGION
THURSDAY AND FRIDAY. ANOTHER COLD FRONT AFFECTING THE AREA SATURDAY
WITH A CHANCE OF SHOWERS. TEMPS AT OR SLIGHTLY ABOVE NORMAL.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
LOWER LEVEL CLOUD DECK HAS BROKEN UP THIS AFTERNOON. WINDS
CONTINUE TO RANGE FROM LIGHT EASTERLY TO CALM. HIGH PRESSURE RIDGE
OVER THE MID ATLANTIC STATES EXTENDING SOUTHWEST ACROSS THE
SOUTHEAST UNITED STATES ARE KEEPING THAT WEAK EASTERLY TO
NORTHEASTERLY FLOW IN THE LOW LEVELS. MEANWHILE A RIDGE OF HIGH
PRESSURE IS BUILDING IN FROM THE WEST BEHIND A SHORT WAVE WHICH
BROUGHT THE CLOUDINESS THIS MORNING. HIGH LEVEL CLOUDINESS
CONTINUES TO STREAM IN ACROSS THE REGION THIS AFTERNOON.
EXPECT SCATTERED MID LEVEL CLOUDINESS FOR THE REMAINDER OF THE DAY
AS WELL AS HIGH CLOUDS. LOW LEVEL FLOW WILL KEEP MOISTURE IN THE
LOW LEVELS FOR THE NEXT 24 HOURS. UPPER LEVEL RIDGE WILL HELP
KEEP THE MOISTURE TRAPPED NEAR THE SURFACE. LIGHT WINDS AND
MOISTURE IS SETTING UP A CHANCE OF FOG TOWARD SUNDAY MORNING AT
ALL TERMINALS. QUESTION IS...WILL THE UPPER CLOUDINESS BECOME THIN
ENOUGH TO ALLOW RADIATIONAL COOLING NECESSARY FOR FOG DEVELOPMENT.
GFS MOS IS INDICATING A GOOD CHANCE OF MVFR TO IFR FOG DEVELOPMENT
WHILE THE NAM IS LESS FAVORABLE FOR FOG DEVELOPMENT. LEANED THE
FORECAST TOWARD THE GFS...PLACING MVFR CONDITIONS AT ALL TERMINALS
TOWARD SUNDAY MORNING WITH VFR CONDITIONS RETURNING LATER SUNDAY MORNING.
HOWEVER...CONFIDENCE IS TOO LOW TO PLACE IFR CONDITIONS IN THE
FOR CAST. WILL WAIT FOR LATER MODEL RUNS TO BETTER DETERMINE THAT
CHANCE.
EXTENDED AVIATION OUTLOOK...LOW LEVEL MOISTURE COULD PROVIDE MVFR
CONDITIONS EACH MORNING THROUGH TUESDAY. MVFR CONDITIONS ARE
POSSIBLE INTO WEDNESDAY MORNING AHEAD OF AN APPROACHING FRONT.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1213 PM CST SAT DEC 1 2012
.AVIATION...
LOW LEVEL MOISTURE WILL CONTINUE TO INCREASE INTO TNGT WITH
CONDITIONS DETERIORATING TO IFR AND LIFR IN LOW CLOUDS... FOG
AND DRIZZLE. IN ADDITION... WILL SEE AT LEAST SCT SHRA OVER
THE AREA INTO THIS EVE AHEAD OF AN UPPER LEVEL DISTURBANCE.
CANT RULE OUT EVEN AN ELEVATED ISOLD TSRA WITH LOW LEVEL JET
BUT ANY DEVELOPMENT MAINLY FAVORED EAST OF THE MISSISSIPPI
RIVER... BUT PROBS TOO LOW FOR INCLUSION AT KMLI. ANTICIPATE
AREAS OF DENSE FOG AND VLIFR CONDITIONS TO DEVELOP THIS EVE
INTO THE OVRNGT WITH DECREASING WINDS AND WEAK LOW LEVEL
CONVERGENCE AHEAD OF SFC TROUGH/WIND SHIFT. THIS TROUGH WILL
SAG THROUGH THE REGION LATE TNGT THROUGH SUN AM... AND THE
COMBINATION OF WESTERLY WINDS AND LOW LEVEL DRYING LIKELY TO
BRING IMPROVEMENT IN BOTH VSBYS AND CIGS FROM NW TO SE AT THE
TERMINALS.
&&
.PREV DISCUSSION... /ISSUED 311 AM CST SAT DEC 1 2012/
SYNOPSIS...
06Z SFC ANALYSIS HAS THE FRONTAL BOUNDARY FROM THE SOUTH SHORE OF
LAKE ERIE WEST SOUTHWEST INTO NORTHERN KANSAS. DEW POINTS SOUTH OF
THE FRONT WERE IN THE 40S AND 50S WHILE 20S AND 30S WERE NORTH OF
THE FRONT. SATELLITE TRENDS SHOW A LARGE EXPANSE OF LOW CLOUDS
ACROSS WI/MN WITH ADDITIONAL LOW CLOUDS MOVING NORTH THROUGH
MISSOURI AND KANSAS WITH A SLOWLY THICKENING CI/CS SHIELD IN
BETWEEN.
SHORT TERM...TODAY AND TONIGHT...
BASED ON REAL DATA...THE RAP APPEARS TO HAVE A REASONABLY GOOD
HANDLE ON THE LOW CLOUDS APPROACHING FROM THE SOUTH IN THE 900-950MB
LAYER RH. USING THIS AND SATELLITE INDICATES THE LOW CLOUDS SHOULD
ENTER THE FAR SOUTHWESTERN PART OF THE CWFA PRIOR TO SUNRISE AND
OVERSPREAD THE CWFA DURING THE MORNING HOURS. AHEAD OF THESE LOW
CLOUDS SHOULD BE PATCHY TO AREAS OF FOG. ONCE THE LOW CLOUDS
ARRIVE THE FOG SHOULD BECOME MORE PATCHY.
USING THE OVERALL FORCING AND CONDENSATION PRESSURE DEFICITS FROM
TRENDS IN THE RAP MODEL...DRIZZLE SHOULD DEVELOP BY MID TO LATE
MORNING UNDER THE LOW CLOUDS WITH SOME PATCHY LIGHT RAIN POSSIBLE.
FCST SOUNDINGS INDICATE PLENTY OF DRIZZLE SHOULD BE SEEN ACROSS THE
AREA DURING THE AFTERNOON HOURS WITH SOME LIGHT RAIN BASED ON THE
INCREASED FORCING AND LOWERING CONDENSATION PRESSURE DEFICITS.
MAX TEMPERATURES TODAY WILL BE INTERESTING. IN SPITE OF THE CI/CS
SHIELD...AREAS AHEAD OF THE LOW CLOUDS SHOULD WARM UP DURING THE
MORNING. THE CONTINUED PUSH OF LOW LEVEL MOISTURE INTO THE AREA WILL
ALSO BODILY FORCE TEMPERATURES UP IN SPITE OF THE LOW CLOUDS ACROSS
THE AREA DURING THE AFTERNOON. THE CURRENT MAX TEMPS OF LOW 50S TO
LOW 60S MAY STILL BE A BIT TOO WARM.
TONIGHT...DRIZZLE WILL CONTINUE ACROSS THE AREA DURING THE EVENING
HOURS ALONG WITH SOME LIGHT RAIN. AFTER MIDNIGHT THE RAIN AND
DRIZZLE WILL SLOWLY END FROM WEST TO EAST. THERE MAY OR MAY NOT BE
SOME PATCHY FOG THAT OCCURS AFTER MIDNIGHT AS THE PRECIPITATION ENDS
AND THE ATMOSPHERE COOLS. 08
LONG TERM...SUNDAY THROUGH FRIDAY...
MODELS CONTINUE TO SHOW A SERIES OF SHORT WAVES MOVING THROUGH THE
REGION IN A PERSISTENT ZONAL FLOW PATTERN. SYSTEMS ARE PROGGED TO
MOVE THROUGH THE REGION MONDAY AND THURSDAY NIGHT. EACH SYSTEM WILL
BE LACKING SIGNIFICANT...DEEP...MOISTURE AS THEY APPROACH THE REGION
AND START TO PICKUP SOME GULF MOISTURE AS THEY MOVE THROUGH. THE
GENERAL TREND THEN WILL BE BETTER CHANCES OF RAIN EAST OF THE
MISSISSIPPI RIVER. THE ZONAL PATTERN WILL ALSO KEEP MOST OF THE
COLD AIR OVER CANADA THROUGH MID WEEK. A BRIEF INTRUSION OF
CANADIAN AIR WILL OCCUR BEHIND THE EARLY WEEK SYSTEM BUT WILL STAY
WELL NORTH AND NORTHEAST OF THE FORECAST AREA. THERE IS GOOD
AGREEMENT BETWEEN THE 00Z GFS/ECMWF THAT THE END OF THE WEEK SYSTEM
WILL HAVE ENOUGH AMPLIFICATION TO PULL THE COLDER AIR FURTHER SOUTH
AND SHOULD RETURN NEAR NORMAL TEMPERATURES TO THE AREA FOR THE END
OF THE WEEK.
SUNDAY RETURN FLOW WILL BE DEVELOPING DURING THE DAY AS WEAK SURFACE
HIGH PRESSURE MOVES EAST OF THE CWFA. THE LIGHT SOUTH FLOW WITH
MOSTLY SUNNY SKIES SHOULD PUSH TEMPERATURES INTO THE LOW 60S SOUTH
AND MID TO UPPER 50S NORTH. THE SOUTHERN AREAS WILL BE CLOSE TO
RECORD HIGHS FOR SUNDAY. SUNDAY NIGHT INTO MONDAY MORNING THE
MODELS ARE SHOWING A GOOD SURGE OF LOW LEVEL MOISTURE INTO THE
REGION SUGGESTING SOME STRATUS AND POSSIBLY DRIZZLE DEVELOPING AFTER
MIDNIGHT AND CONTINUING INTO MONDAY MORNING. THE NAM WAS ALSO
SUGGESTING SOME CONVECTIVE POTENTIAL LATE SUNDAY NIGHT AS IT MOVED
AN AREA OF ELEVATED CAPES AROUND 700J/KG AND STEEP MID LEVEL LAPSE
RATES NORTHEAST THROUGH THE FORECAST AREA. THE GFS THOUGH WAS
BARELY SHOWING ANY CAPE FOR THE SAME TIME PERIOD SO WILL HOLD OFF ON
MENTIONING ANY TSRA FOR NOW. THE COLD FRONT IS EXPECTED TO MOVE
THROUGH DURING THE LATE AFTERNOON AND EARLY EVENING WITH RAIN
CHANCES INCREASING WITH THE FROPA. DUE TO THE SHALLOW
MOISTURE...POPS WILL BE KEPT IN THE CHANCE CATEGORY. RAIN CHANCES
WERE CONTINUED THROUGH TUESDAY MORNING PER THE 00Z ECMWF. IF THE
MORE PROGRESSIVE GFS VERIFIES THEN THE RAIN SHOULD BE EAST OF THE
FORECAST AREA BY MIDNIGHT.
WITH THE INFLUX OF MOISTURE SUNDAY NIGHT MINS WILL PROBABLY BE
REACHED DURING THE EVENING THEN HOLD STEADY OR RISE SOME AFTER
MIDNIGHT. BY MONDAY MORNING INCREASING SURFACE DEWPOINTS WILL DRIVE
TEMPERATURES INTO THE 50S. DESPITE LOW CLOUDS AND DRIZZLE MONDAY
MORNING...THE CONTINUING WARM ADVECTION SHOULD PUSH TEMPS INTO THE
60S OVER THE ENTIRE AREA...JUST UNDER RECORD HIGHS FOR THE 3RD.
FOR TUESDAY THROUGH WEDNESDAY DRY CONDITIONS ARE EXPECTED WITH
TEMPERATURES COOLING OFF SOME BUT STILL STAYING ABOVE NORMAL. THE
NEXT SYSTEM IS PROGGED TO MOVE THROUGH THE REGION THURSDAY SO CHANCE
POPS FOR RAIN LOOK REASONABLE THURSDAY INTO FRIDAY. THE MORE
AMPLIFIED WAVE IS EXPECTED TO BRING THE COLDER AIR FURTHER SOUTH
RETURNING LATE WEEK TEMPERATURES TO NEAR NORMAL.
DLF
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
540 AM CST SAT DEC 1 2012
.AVIATION...
VFR TO IFR CONDITIONS WILL SLOWLY DETERIORATE TO IFR/LIFR
CONDITIONS THROUGH 18Z/01 AS LOW CLOUDS MOVE NORTHEAST FROM
MISSOURI AND KANSAS. IFR/LIFR CONDITIONS WITH DZ OR SHRA ARE THEN
EXPECTED THROUGH 06Z/02 BEFORE A SLOW IMPROVEMENT BEGINS. THERE IS
A POSSIBILITY OF MORE FOG AFT 06Z/02 WHICH MAY ALLOW THE IFR/LIFR
CONDITIONS TO PERSIST. ..08..
&&
.PREV DISCUSSION... /ISSUED 311 AM CST SAT DEC 1 2012/
SYNOPSIS...
06Z SFC ANALYSIS HAS THE FRONTAL BOUNDARY FROM THE SOUTH SHORE OF
LAKE ERIE WEST SOUTHWEST INTO NORTHERN KANSAS. DEW POINTS SOUTH OF
THE FRONT WERE IN THE 40S AND 50S WHILE 20S AND 30S WERE NORTH OF
THE FRONT. SATELLITE TRENDS SHOW A LARGE EXPANSE OF LOW CLOUDS
ACROSS WI/MN WITH ADDITIONAL LOW CLOUDS MOVING NORTH THROUGH
MISSOURI AND KANSAS WITH A SLOWLY THICKENING CI/CS SHIELD IN
BETWEEN.
SHORT TERM...TODAY AND TONIGHT...
BASED ON REAL DATA...THE RAP APPEARS TO HAVE A REASONABLY GOOD
HANDLE ON THE LOW CLOUDS APPROACHING FROM THE SOUTH IN THE 900-950MB
LAYER RH. USING THIS AND SATELLITE INDICATES THE LOW CLOUDS SHOULD
ENTER THE FAR SOUTHWESTERN PART OF THE CWFA PRIOR TO SUNRISE AND
OVERSPREAD THE CWFA DURING THE MORNING HOURS. AHEAD OF THESE LOW
CLOUDS SHOULD BE PATCHY TO AREAS OF FOG. ONCE THE LOW CLOUDS
ARRIVE THE FOG SHOULD BECOME MORE PATCHY.
USING THE OVERALL FORCING AND CONDENSATION PRESSURE DEFICITS FROM
TRENDS IN THE RAP MODEL...DRIZZLE SHOULD DEVELOP BY MID TO LATE
MORNING UNDER THE LOW CLOUDS WITH SOME PATCHY LIGHT RAIN POSSIBLE.
FCST SOUNDINGS INDICATE PLENTY OF DRIZZLE SHOULD BE SEEN ACROSS THE
AREA DURING THE AFTERNOON HOURS WITH SOME LIGHT RAIN BASED ON THE
INCREASED FORCING AND LOWERING CONDENSATION PRESSURE DEFICITS.
MAX TEMPERATURES TODAY WILL BE INTERESTING. IN SPITE OF THE CI/CS
SHIELD...AREAS AHEAD OF THE LOW CLOUDS SHOULD WARM UP DURING THE
MORNING. THE CONTINUED PUSH OF LOW LEVEL MOISTURE INTO THE AREA WILL
ALSO BODILY FORCE TEMPERATURES UP IN SPITE OF THE LOW CLOUDS ACROSS
THE AREA DURING THE AFTERNOON. THE CURRENT MAX TEMPS OF LOW 50S TO
LOW 60S MAY STILL BE A BIT TOO WARM.
TONIGHT...DRIZZLE WILL CONTINUE ACROSS THE AREA DURING THE EVENING
HOURS ALONG WITH SOME LIGHT RAIN. AFTER MIDNIGHT THE RAIN AND
DRIZZLE WILL SLOWLY END FROM WEST TO EAST. THERE MAY OR MAY NOT BE
SOME PATCHY FOG THAT OCCURS AFTER MIDNIGHT AS THE PRECIPITATION ENDS
AND THE ATMOSPHERE COOLS. ..08..
LONG TERM...SUNDAY THROUGH FRIDAY...
MODELS CONTINUE TO SHOW A SERIES OF SHORT WAVES MOVING THROUGH THE
REGION IN A PERSISTENT ZONAL FLOW PATTERN. SYSTEMS ARE PROGGED TO
MOVE THROUGH THE REGION MONDAY AND THURSDAY NIGHT. EACH SYSTEM WILL
BE LACKING SIGNIFICANT...DEEP...MOISTURE AS THEY APPROACH THE REGION
AND START TO PICKUP SOME GULF MOISTURE AS THEY MOVE THROUGH. THE
GENERAL TREND THEN WILL BE BETTER CHANCES OF RAIN EAST OF THE
MISSISSIPPI RIVER. THE ZONAL PATTERN WILL ALSO KEEP MOST OF THE
COLD AIR OVER CANADA THROUGH MID WEEK. A BRIEF INTRUSION OF
CANADIAN AIR WILL OCCUR BEHIND THE EARLY WEEK SYSTEM BUT WILL STAY
WELL NORTH AND NORTHEAST OF THE FORECAST AREA. THERE IS GOOD
AGREEMENT BETWEEN THE 00Z GFS/ECMWF THAT THE END OF THE WEEK SYSTEM
WILL HAVE ENOUGH AMPLIFICATION TO PULL THE COLDER AIR FURTHER SOUTH
AND SHOULD RETURN NEAR NORMAL TEMPERATURES TO THE AREA FOR THE END
OF THE WEEK.
SUNDAY RETURN FLOW WILL BE DEVELOPING DURING THE DAY AS WEAK SURFACE
HIGH PRESSURE MOVES EAST OF THE CWFA. THE LIGHT SOUTH FLOW WITH
MOSTLY SUNNY SKIES SHOULD PUSH TEMPERATURES INTO THE LOW 60S SOUTH
AND MID TO UPPER 50S NORTH. THE SOUTHERN AREAS WILL BE CLOSE TO
RECORD HIGHS FOR SUNDAY. SUNDAY NIGHT INTO MONDAY MORNING THE
MODELS ARE SHOWING A GOOD SURGE OF LOW LEVEL MOISTURE INTO THE
REGION SUGGESTING SOME STRATUS AND POSSIBLY DRIZZLE DEVELOPING AFTER
MIDNIGHT AND CONTINUING INTO MONDAY MORNING. THE NAM WAS ALSO
SUGGESTING SOME CONVECTIVE POTENTIAL LATE SUNDAY NIGHT AS IT MOVED
AN AREA OF ELEVATED CAPES AROUND 700J/KG AND STEEP MID LEVEL LAPSE
RATES NORTHEAST THROUGH THE FORECAST AREA. THE GFS THOUGH WAS
BARELY SHOWING ANY CAPE FOR THE SAME TIME PERIOD SO WILL HOLD OFF ON
MENTIONING ANY TSRA FOR NOW. THE COLD FRONT IS EXPECTED TO MOVE
THROUGH DURING THE LATE AFTERNOON AND EARLY EVENING WITH RAIN
CHANCES INCREASING WITH THE FROPA. DUE TO THE SHALLOW
MOISTURE...POPS WILL BE KEPT IN THE CHANCE CATEGORY. RAIN CHANCES
WERE CONTINUED THROUGH TUESDAY MORNING PER THE 00Z ECMWF. IF THE
MORE PROGRESSIVE GFS VERIFIES THEN THE RAIN SHOULD BE EAST OF THE
FORECAST AREA BY MIDNIGHT.
WITH THE INFLUX OF MOISTURE SUNDAY NIGHT MINS WILL PROBABLY BE
REACHED DURING THE EVENING THEN HOLD STEADY OR RISE SOME AFTER
MIDNIGHT. BY MONDAY MORNING INCREASING SURFACE DEWPOINTS WILL DRIVE
TEMPERATURES INTO THE 50S. DESPITE LOW CLOUDS AND DRIZZLE MONDAY
MORNING...THE CONTINUING WARM ADVECTION SHOULD PUSH TEMPS INTO THE
60S OVER THE ENTIRE AREA...JUST UNDER RECORD HIGHS FOR THE 3RD.
FOR TUESDAY THROUGH WEDNESDAY DRY CONDITIONS ARE EXPECTED WITH
TEMPERATURES COOLING OFF SOME BUT STILL STAYING ABOVE NORMAL. THE
NEXT SYSTEM IS PROGGED TO MOVE THROUGH THE REGION THURSDAY SO CHANCE
POPS FOR RAIN LOOK REASONABLE THURSDAY INTO FRIDAY. THE MORE
AMPLIFIED WAVE IS EXPECTED TO BRING THE COLDER AIR FURTHER SOUTH
RETURNING LATE WEEK TEMPERATURES TO NEAR NORMAL.
DLF
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
311 AM CST SAT DEC 1 2012
.SYNOPSIS...
06Z SFC ANALYSIS HAS THE FRONTAL BOUNDARY FROM THE SOUTH SHORE OF
LAKE ERIE WEST SOUTHWEST INTO NORTHERN KANSAS. DEW POINTS SOUTH OF
THE FRONT WERE IN THE 40S AND 50S WHILE 20S AND 30S WERE NORTH OF
THE FRONT. SATELLITE TRENDS SHOW A LARGE EXPANSE OF LOW CLOUDS
ACROSS WI/MN WITH ADDITIONAL LOW CLOUDS MOVING NORTH THROUGH
MISSOURI AND KANSAS WITH A SLOWLY THICKENING CI/CS SHIELD IN
BETWEEN.
&&
.SHORT TERM...TODAY AND TONIGHT...
BASED ON REAL DATA...THE RAP APPEARS TO HAVE A REASONABLY GOOD
HANDLE ON THE LOW CLOUDS APPROACHING FROM THE SOUTH IN THE 900-950MB
LAYER RH. USING THIS AND SATELLITE INDICATES THE LOW CLOUDS SHOULD
ENTER THE FAR SOUTHWESTERN PART OF THE CWFA PRIOR TO SUNRISE AND
OVERSPREAD THE CWFA DURING THE MORNING HOURS. AHEAD OF THESE LOW
CLOUDS SHOULD BE PATCHY TO AREAS OF FOG. ONCE THE LOW CLOUDS
ARRIVE THE FOG SHOULD BECOME MORE PATCHY.
USING THE OVERALL FORCING AND CONDENSATION PRESSURE DEFICITS FROM
TRENDS IN THE RAP MODEL...DRIZZLE SHOULD DEVELOP BY MID TO LATE
MORNING UNDER THE LOW CLOUDS WITH SOME PATCHY LIGHT RAIN POSSIBLE.
FCST SOUNDINGS INDICATE PLENTY OF DRIZZLE SHOULD BE SEEN ACROSS THE
AREA DURING THE AFTERNOON HOURS WITH SOME LIGHT RAIN BASED ON THE
INCREASED FORCING AND LOWERING CONDENSATION PRESSURE DEFICITS.
MAX TEMPERATURES TODAY WILL BE INTERESTING. IN SPITE OF THE CI/CS
SHIELD...AREAS AHEAD OF THE LOW CLOUDS SHOULD WARM UP DURING THE
MORNING. THE CONTINUED PUSH OF LOW LEVEL MOISTURE INTO THE AREA WILL
ALSO BODILY FORCE TEMPERATURES UP IN SPITE OF THE LOW CLOUDS ACROSS
THE AREA DURING THE AFTERNOON. THE CURRENT MAX TEMPS OF LOW 50S TO
LOW 60S MAY STILL BE A BIT TOO WARM.
TONIGHT...DRIZZLE WILL CONTINUE ACROSS THE AREA DURING THE EVENING
HOURS ALONG WITH SOME LIGHT RAIN. AFTER MIDNIGHT THE RAIN AND
DRIZZLE WILL SLOWLY END FROM WEST TO EAST. THERE MAY OR MAY NOT BE
SOME PATCHY FOG THAT OCCURS AFTER MIDNIGHT AS THE PRECIPITATION ENDS
AND THE ATMOSPHERE COOLS. ..08..
.LONG TERM...SUNDAY THROUGH FRIDAY...
MODELS CONTINUE TO SHOW A SERIES OF SHORT WAVES MOVING THROUGH THE
REGION IN A PERSISTENT ZONAL FLOW PATTERN. SYSTEMS ARE PROGGED TO
MOVE THROUGH THE REGION MONDAY AND THURSDAY NIGHT. EACH SYSTEM WILL
BE LACKING SIGNIFICANT...DEEP...MOISTURE AS THEY APPROACH THE REGION
AND START TO PICKUP SOME GULF MOISTURE AS THEY MOVE THROUGH. THE
GENERAL TREND THEN WILL BE BETTER CHANCES OF RAIN EAST OF THE
MISSISSIPPI RIVER. THE ZONAL PATTERN WILL ALSO KEEP MOST OF THE
COLD AIR OVER CANADA THROUGH MID WEEK. A BRIEF INTRUSION OF
CANADIAN AIR WILL OCCUR BEHIND THE EARLY WEEK SYSTEM BUT WILL STAY
WELL NORTH AND NORTHEAST OF THE FORECAST AREA. THERE IS GOOD
AGREEMENT BETWEEN THE 00Z GFS/ECMWF THAT THE END OF THE WEEK SYSTEM
WILL HAVE ENOUGH AMPLIFICATION TO PULL THE COLDER AIR FURTHER SOUTH
AND SHOULD RETURN NEAR NORMAL TEMPERATURES TO THE AREA FOR THE END
OF THE WEEK.
SUNDAY RETURN FLOW WILL BE DEVELOPING DURING THE DAY AS WEAK SURFACE
HIGH PRESSURE MOVES EAST OF THE CWFA. THE LIGHT SOUTH FLOW WITH
MOSTLY SUNNY SKIES SHOULD PUSH TEMPERATURES INTO THE LOW 60S SOUTH
AND MID TO UPPER 50S NORTH. THE SOUTHERN AREAS WILL BE CLOSE TO
RECORD HIGHS FOR SUNDAY. SUNDAY NIGHT INTO MONDAY MORNING THE
MODELS ARE SHOWING A GOOD SURGE OF LOW LEVEL MOISTURE INTO THE
REGION SUGGESTING SOME STRATUS AND POSSIBLY DRIZZLE DEVELOPING AFTER
MIDNIGHT AND CONTINUING INTO MONDAY MORNING. THE NAM WAS ALSO
SUGGESTING SOME CONVECTIVE POTENTIAL LATE SUNDAY NIGHT AS IT MOVED
AN AREA OF ELEVATED CAPES AROUND 700J/KG AND STEEP MID LEVEL LAPSE
RATES NORTHEAST THROUGH THE FORECAST AREA. THE GFS THOUGH WAS
BARELY SHOWING ANY CAPE FOR THE SAME TIME PERIOD SO WILL HOLD OFF ON
MENTIONING ANY TSRA FOR NOW. THE COLD FRONT IS EXPECTED TO MOVE
THROUGH DURING THE LATE AFTERNOON AND EARLY EVENING WITH RAIN
CHANCES INCREASING WITH THE FROPA. DUE TO THE SHALLOW
MOISTURE...POPS WILL BE KEPT IN THE CHANCE CATEGORY. RAIN CHANCES
WERE CONTINUED THROUGH TUESDAY MORNING PER THE 00Z ECMWF. IF THE
MORE PROGRESSIVE GFS VERIFIES THEN THE RAIN SHOULD BE EAST OF THE
FORECAST AREA BY MIDNIGHT.
WITH THE INFLUX OF MOISTURE SUNDAY NIGHT MINS WILL PROBABLY BE
REACHED DURING THE EVENING THEN HOLD STEADY OR RISE SOME AFTER
MIDNIGHT. BY MONDAY MORNING INCREASING SURFACE DEWPOINTS WILL DRIVE
TEMPERATURES INTO THE 50S. DESPITE LOW CLOUDS AND DRIZZLE MONDAY
MORNING...THE CONTINUING WARM ADVECTION SHOULD PUSH TEMPS INTO THE
60S OVER THE ENTIRE AREA...JUST UNDER RECORD HIGHS FOR THE 3RD.
FOR TUESDAY THROUGH WEDNESDAY DRY CONDITIONS ARE EXPECTED WITH
TEMPERATURES COOLING OFF SOME BUT STILL STAYING ABOVE NORMAL. THE
NEXT SYSTEM IS PROGGED TO MOVE THROUGH THE REGION THURSDAY SO CHANCE
POPS FOR RAIN LOOK REASONABLE THURSDAY INTO FRIDAY. THE MORE
AMPLIFIED WAVE IS EXPECTED TO BRING THE COLDER AIR FURTHER SOUTH
RETURNING LATE WEEK TEMPERATURES TO NEAR NORMAL.
DLF
&&
.AVIATION...
RAP MODEL TRENDS INDICATE THE LOW LEVEL STRATUS WITH MVFR/IFR CIGS
SHOULD MOVE INTO EASTERN IOWA SHORTLY BEFORE SUNRISE AND AFFECT ALL
TAF SITES BY 18Z/01. AHEAD OF THE LOW CLOUDS MVFR/IFR CONDITIONS IN
FOG ARE EXPECTED WITH POCKETS OF LIFR/VLIFR CONDITIONS POSSIBLE.
ONCE THE LOW CLOUDS ARRIVE...A PROLONGED PERIOD OF IFR/LIFR
CONDITIONS ARE EXPECTED. ..08..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS TOPEKA KS
549 PM CST SUN DEC 2 2012
...UPDATE TO AVIATION...
.DISCUSSION...
SHORT TERM FORECAST (TONIGHT AND MONDAY)...
AT 21Z SURFACE OBSERVATIONS AND ASSOCIATED RAP ANALYSIS INDICATES A
DECENT PRESSURE GRADIENT FORMING ACROSS EASTERN KANSAS IN RESPONSE
TO A LEE SIDE SURFACE TROUGH FORMING ON THE EAST SIDE OF THE
ROCKIES...OVER THE CENTRAL HIGH PLAINS. THIS PRESSURE GRADIENT HAS
ALLOWED FOR SOUTHERLY FLOW TO INCREASE THROUGH OUT THE DAY AS WARM
AND MOIST AIR MOVES INTO THE AREA. ALTHOUGH DEWPOINTS THROUGHOUT THE
AREA ARE ONLY IN THE LOWER TO MID 40S OBSERVATIONS FROM ACROSS
OK..AR..AND SOUTHERN MISSOURI INDICATE THAT A DECENT AMOUNT OF LOW
LEVEL MOISTURE IN THE FORM OF UPPER 50 TO LOWER 60 DEGREE DEWPOINTS
RESIDES AND IS POISED TO MAKE A SURGE NORTHWARD AS THE PREVIOUSLY
MENTIONED TROUGH MOVES OFF THE HIGH PLAINS. DIFFICULT FORECAST
REMAINS FOR THE OVERNIGHT HOURS AS THE MOISTURE SURGES NORTH. GIVEN
THE SHALLOW NATURE OF THE GOOD MOISTURE WITH VERY DRY AIR ABOVE THE
LOW LEVEL MOISTURE WILL RULE OUT MEASURABLE PRECIPITATION FOR THE
OVERNIGHT HOURS...HOWEVER A LOW STRATUS DECK DOES SEEM RATHER LIKELY
WITH POSSIBLY SOME VERY MINOR DRIZZLE. ALSO WILL NOT RULE OUT THE
POSSIBILITY OF SOME PATCHY FOG AS SOME MODEL GUIDANCE SUGGESTS AREAS
OF REDUCED VISIBILITY...ESPECIALLY ALONG AND EAST OF HIGHWAY 75.
CANNOT COMPLETELY RULE OUT DENSE FOG OVERNIGHT...ESPECIALLY IN THE
AFOREMENTIONED FAR EASTERN KANSAS AREAS...BUT GIVEN THE FACT THAT
SOUTHERLY WINDS OF AROUND 10 TO 20 MPH WILL BE PERSISTENT FOR MUCH
OF THE NIGHT THE FEELING IS THAT THE LOWER ATMOSPHERE MAY BE TOO
MIXED TO CONSIDER WIDESPREAD DENSE FOG. LOW STRATUS/FOG WILL LIKELY
REMAIN IN THE AREA THROUGH THE MID MORNING BEFORE MIXING GRADUALLY
DISSIPATES THE STRATUS BY MID MORNING/EARLY AFTERNOON. FOR MONDAY WE
CAN EXPECT ONE MORE DAY WITH TEMPS NEARLY 25 DEGREES WARMER THAN
SEASONAL NORMALS. A COLD FRONT STANDS POISED TO MOVE THROUGH THE
AREA DURING THE DAY ON MONDAY. ALTHOUGH THIS FRONT WILL ACT TO BRING
TEMPS DOWN A FEW DEGREES IT WILL HARDLY BRING THE SURGE OF COLD AIR
TYPICALLY ASSOCIATED WITH DECEMBER AS TEMPS FOR THE MIDDLE PART OF
THE WEEK WILL REMAIN WELL ABOVE NORMAL.
JL
LONG TERM - TUESDAY THROUGH SUNDAY...
TUESDAY THROUGH WEDNESDAY NIGHT - THE COLD FRONT WILL HAVE PASSED
COMPLETELY THROUGH THE FORECAST AREA BY MONDAY EVENING AND ANY
PRECIPITATION SHOULD HAVE SHIFTED SOUTHEAST WITH THE FRONT. COLD
AND DRY ADVECTION WILL TAKE PLACE INTO TUESDAY BUT A NORTH BREEZE
OVERNIGHT WILL KEEP TUESDAY MORNING LOWS IN THE 30S AND THE WARM
START ALONG WITH DECENT MIXING SHOULD ALLOW AFTERNOON HIGHS TO
GET INTO THE LOWER 60S. RETURN FLOW WITH SOME WARM MOIST ADVECTION
WILL THEN TAKE OVER BY WEDNESDAY AS A WEAK SHORT WAVE TROUGH AND
SURFACE LOW PRESSURE MOVE INTO THE NORTHERN HIGH PLAINS. WHILE
TEMPERATURES ALOFT WILL BE WARMER ON WEDNESDAY...COULD SEE MORE IN
THE WAY OF CLOUDS AND LESS MIXING...RESULTING IN HIGHS STILL IN
THE LOWER 60S. MORE SUN COULD ALLOW HIGHS TO SNEAK INTO THE UPPER
60S IN A FEW SPOTS THOUGH. EXPECT LOW CLOUDS TO FILL IN FURTHER BY
WEDNESDAY NIGHT AS THE LOW LEVEL MOISTURE INFLUX INCREASES.
CLOUDS WILL KEEP LOWS WARMER.
THURSDAY THROUGH FRIDAY - A COLD FRONT ASSOCIATED WITH THE
NORTHERN PLAINS SHORT WAVE TROUGH WILL MOVE THROUGH THE FORECAST
AREA DURING THE DAY ON THURSDAY WITH ANOTHER ROUND OF MORE
SUBSTANTIAL COLD ADVECTION IN ITS WAKE. THERE WILL BE A DECENT
AMOUNT OF LOW LEVEL FORCING ALONG THE FRONT AND IT WILL INTERACT
WITH A FAIR AMOUNT OF GULF MOISTURE...BUT UPPER SUPPORT IS LACKING
AND SUSPECT THAT THE END RESULT MAY BE SIMILAR TO THE FRONTAL
PASSAGE ON MONDAY WITH THE BULK OF PRECIPITATION DEVELOPING
SOUTHEAST OF THE FORECAST AREA. HAVE STILL KEPT AT LEAST A CHANCE
OF SHOWERS ACROSS THE SOUTHEAST HALF OF THE FORECAST AREA FOR
UNCERTAINTY IN FRONTAL TIMING AND AT LEAST THE POTENTIAL FOR
EARLIER PRECIP DEVELOPMENT WHILE THE FRONT IS STILL IN THE LOCAL
AREA. THE BOUNDARY SHOULD PUSH SOUTHEAST OF THE FORECAST AREA BY
EARLY FRIDAY MORNING WITH A COOLER AND DRIER AIRMASS FILTERING IN.
FRIDAY NIGHT THROUGH SUNDAY - UNCERTAINTY IS HIGH DURING THIS
PERIOD REGARDING PRECIPITATION POTENTIAL WITH SIGNIFICANT MODEL
VARIANCE. MUCH OF THE VARIABILITY IS DUE TO HOW THE FLOW PATTERN
OVER THE PACIFIC OCEAN WILL EVOLVE IN THE NEXT FEW DAYS. IT DOES
APPEAR THAT A TRANSITION TO A MORE SOUTHWESTERLY FLOW PATTERN OVER
THE CENTRAL AND EASTERN CONUS WILL HAPPEN IN THE LONG TERM WITH
MOISTURE LINGERING NOT FAR TO THE SOUTH AND OCCASIONAL
DISTURBANCES INTERACTING WITH A FRONTAL BOUNDARY. HOWEVER THE
TIMING OF THE DISTURBANCES AND THE LOCATION OF THE FRONT ARE VERY
MUCH IN QUESTION. THE END RESULT FOR THIS FORECAST IS ACTUALLY FOR
COOLER...BUT NEAR NORMAL TEMPERATURES DURING THIS PERIOD WITH SOME
POTENTIAL FOR A STORM SYSTEM TO BRING PRECIPITATION TO THE REGION
BY THE WEEKEND. CURRENTLY HAVE INDICATED RAIN IN THE FORECAST...
BUT THERE WOULD BE AT LEAST SOME POTENTIAL FOR A BIT OF
SNOW...DEPENDING ON PRECIPITATION TIMING.
BARJENBRUCH
&&
.AVIATION...
LLVL MOISTURE WILL SURGE BACK TO THE NORTH ACROSS THE
TERMINALS AFT 06Z WHICH WILL INITIALLY RESULT IN MVFR STRATUS
AND FOG FORMATION...THEN LOWER TO IFR IN KTOP/KFOE BY 10Z. AS THE
LLVL FLOW VEERS THROUGH 14Z SOUTHERLY WINDS WILL VEER TO THE
SOUTHWEST AS CIGS RISE TO AROUND 2000 FT. AS COLD FRONT APPROACHES
THEN MOVES THROUGH AND DRIER AIR ADVECTS EASTWARD...SHOULD SEE
VFR CONDITIONS ALL AREAS IN THE 18Z-20Z TIME FRAME WITH WINDS
SHIFTING TO THE NORTHWEST 12-20 KTS.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
243 PM CST SAT DEC 1 2012
.SYNOPSIS...
ISSUED AT 933 AM CST SAT DEC 1 2012
THE 01.12Z 250 HPA MAP SHOWED MOSTLY A ZONAL FLOW ACROSS THE NATION
WITH A FEW SUBTLE WAVES. A 120 KT JET WAS OBSERVED ACROSS SOUTHWESTERN
OREGON. ANOTHER 100 KT JET WAS OBSERVED ACROSS NORTH DAKOTA. AT 500
HPA, A DEEP CYCLONE WAS LOCATED WEST OF BRITISH COLUMBIA WITH AN ASSOCIATED
TROF MOVING ACROSS THE PACIFIC NORTHWEST. ANOTHER TROF WAS MOVING OUT
ACROSS THE PLAINS. MID LEVEL TEMPERATURES WERE MAINLY IN THE NEGATIVE
TEENS/20S WITH -30 DEG C AND BELOW CONFINED TO SE CANADA. AT 700 HPA,
TEMPERATURES INCREASED A FEW DEGREES CENTIGRADE AT KDDC AHEAD OF A WAVE.
AT 850 HPA, A WARM PLUME OF AROUND 18 DEG C PREVAILED ACROSS THE SOUTHERN
AND CENTRAL PLAINS. THE ATMOSPHERE WAS FAIRLY DRY AT THIS CONSTANT PRESSURE
LEVEL AS WELL. THE COLDER AIR OF -15 DEG C AND BELOW WAS CONFINED TO
SE CANADA. AT THE SFC, A STATIONARY BOUNDARY WAS DRAPED ACROSS KANSAS.
RESPECTABLE DEWPOINTS...FOR THE BEGINNING OF DECEMBER...WITH VALUES
RUNNING IN THE 50S DEG F WERE SOUTH OF SAID BOUNDARY ACROSS THE SC/SE
PORTION OF THE STATE.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 136 PM CST SAT DEC 1 2012
TONIGHT:
FAIRLY TRANQUIL CONDITIONS ARE EXPECTED TONIGHT. HIGH LEVEL CLOUDS WILL
MOVE OFF TO THE EAST THIS EVENING AND SKIES SHOULD BE CLEAR THROUGH
THE OVERNIGHT HOURS. BUFKIT FORECAST SOUNDINGS, MOS GUIDANCE, THE VERY
END OF THE HRRR RUN, AND THE NSSL WRF MODEL HIGHLIGHTS A CONCERN FOR PATCHY
FOG TOMORROW MORNING. DEWPOINTS WILL BE LOWER THAN COMPARED TO THIS
MORNING. DRIER AIR WILL ADVECT IN FROM THE NW. STILL, CONSIDERING EVERYTHING
ABOVE, I HAVE INSERTED PATCHY FOG ALONG AND EAST OF HIGHWAY 283. THIS
MIGHT BE ON THE LIBERAL SIDE AND MAY HAVE TO BE TRIMMED FARTHER EAST.
OTHERWISE, LOWS WILL BE MAINLY IN THE 30S DEG F.
TOMORROW:
OTHER THAN THE AFOREMENTIONED FOG AND SOME AFTERNOON CIRRUS, TOMORROW
WILL BE CLEAR WITH FULL INSOLATION. DID NOT CHANGE MAXIMUM TEMPERATURES
FOR TOMORROW AS THE GRID LOOKS STILL ON TRACK WITH 12Z DATA. IT WILL
BE VERY WARM TOMORROW WITH HIGHS AROUND 70 DEG F. THE AVERAGE HIGH FOR
THIS TIME OF YEAR IS AROUND 48 DEG F. THESE WARM TEMPERATURES ARE A
RESULT OF THE DEEPENING OF THE LEE SURFACE TROUGH ACROSS EASTERN COLORADO
AND RESULTANT CONTINUED WARM AIR ADVECTION. 850 HPA TEMPERATURES AROUND
15 DEG C AND ADIABATIC MIXING STILL SUPPORT THE WARM TEMPS AT THE SURFACE.
LASTLY, RH`S LOOK MARGINAL FOR TOMORROW SO NOT EXPECTING ANY FIRE WX
CONCERNS ATTM. IT WILL BE BREEZY TOMORROW, BUT NOTHING OUT OF THE ORDINARY
IN TERMS OF WESTERN KANSAS WIND STANDARDS (GENERALLY 12-21 KT).
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 239 PM CST SAT DEC 1 2012
FOR MONDAY, A DRY AND PROGRESSIVE UPPER LEVEL SHORTWAVE TROUGH WILL
MOVE ACROSS THE PLAINS HELPING TO PUSH A COLD FRONT ACROSS WESTERN
KANSAS IN THE MORNING. WINDS WILL BE GUSTY TO 15 TO 25 MPH WITH THE
COLD FRONT. HIGHS WILL STILL BE MILD IN THE 60S. FOR TUESDAY INTO
THURSDAY, DRY WEST TO NORTHWESTERLY UPPER LEVEL FLOW CONTINUES
ACROSS THE CENTRAL CONUS, WITH THE NEXT UPPER LEVEL SHORTWAVE TROUGH
DIGGING INTO THE INTERMOUNTAIN WEST ON THURSDAY FROM THE PACIFIC
NORTHWEST. HIGHS LOOK MILD AND AROUND 60 WITH SOUTHERLY FLOW AHEAD
OF A LEE SURFACE TROUGH. THIS NEXT SHORTWAVE WILL MOVE ACROSS THE
PLAINS ON FRIDAY WITH INCREASING MID AND UPPER LEVEL MOISTURE AND A
CANADIAN COLD FRONT. A FEW LIGHT RAIN OR LIGHT SNOW SHOWERS ARE
POSSIBLE, HOWEVER THE LOWER LEVELS LOOK FAIRLY DRY AND MAY BE MOSTLY
VIRGA. WILL LEAVE A SMALL POP GOING IN CASE. BOTH THE GFS AND ECMWF
SHOW VERY MINOR AMOUNTS IF ANY WITH HIGHS IN THE 40S. BY SATURDAY
THE MODELS DIVERGE WITH THE GFS SHOWING A WARM SOUTHWESTERLY UPPER
LEVEL FLOW, WHILE THE ECMWF IS SHOWING A COOLER NORTHWESTERLY FLOW
ALOFT. CONSENSUS HAS HIGHS IN THE 40S WHICH LOOKS REASONABLE.
OVERNIGHT LOWS THROUGH THE PERIOD LOOK TO BE IN 30S COOLING INTO THE
20S BY SATURDAY MORNING.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1100 AM CST SAT DEC 1 2012
CIGS ARE IMPROVING TO VFR THIS MORNING AS FOG DISSIPATES. MOS GUIDANCE
AND BUFKIT PROFILES SUGGEST FOG IS POSSIBLE AGAIN TOMORROW MORNING.
THIS FOG SHOULD NOT BE AS DENSE AS DRIER AIR ADVECTS IN FROM THE NORTHWEST.
WILL GO AHEAD AND HEDGE TO MVFR FOR KDDC/KHYS AND LET FUTURE SHIFTS ADJUST
AS NEEDED FOR TOMORROW AM.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 34 71 38 65 / 0 0 0 0
GCK 33 71 36 64 / 0 0 0 0
EHA 39 72 38 64 / 0 0 0 0
LBL 36 73 35 65 / 0 0 0 0
HYS 34 71 36 62 / 0 0 0 0
P28 36 73 47 68 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM...KRUSE
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS WICHITA KS
233 PM CST SAT DEC 1 2012
.DISCUSSION...
TONIGHT-SUNDAY NGT:
THE PRIMARY PROBLEM IS FOG POTENTIAL IN SE KS WHERE A WEAK SFC TROF WILL
DRIFT SE OVER THE REGION LATE TONIGHT. THE DIMINISHING SLY WINDS COUPLED
WITH RICH MOISTURE AXIS SITUATED ALONG & SE OF THE TROF SHOULD PROMOTE
FOG REDEVELOPMENT OVER THESE AREAS FROM ~3-10AM. BOTH NAM & HRRR DEPICT
SATURATED LAYER ~300FT DEEP TRAPPED BENEATH SHARP INVERSION DURING THIS
PERIOD. SUNDAY WILL BE VERY WARM AS A GRADUALLY STRENGTHENING WRN PLAINS
SFC TROF INDUCES LWR-DECK FLOW TO RESUME SLY COMPONENT BY MID-DAY. STILL
ANTICIPATE RECORD HIGHS TO BE SET/TIED ACROSS THE REGION...ESPECIALLY IN
CNTRL & SC KS. A VERY BALMY SUNDAY NGT AWAITS NEARLY ALL AREAS AS THE
EWD-DRIFTING SFC TROF INDUCES A PERSISTENT WARM/MOIST SLY FLOW OVER ALL
BUT RUSSELL & BARTON COUNTIES. RECORD WARMEST LOWS ARE POSSIBLE IN SOME
AREAS.
MON & MON NGT:
STILL ANTICIPATE A FEW -SHRA/-TSRA OCCURRING OVER SE KS MON AFTERNOON &
EVENING AS A WEAK MID-LVL SHORTWAVE SCOOTS E FROM THE CNTRL/SRN ROCKIES
ACROSS THE SRN PLAINS. THE WAVE WILL SWEEP A COLD FRONT SE ACROSS KS IN
THE AFTERNOON & EARLY EVENING BUT THE BOUNDARY WILL NOT ENCOUNTER ANY
NOTEWORTHY MOISTURE UNTIL IT VENTURES INTO SE KS.
TUE-FRI NGT:
QUIET WEATHER SLATED FOR ALL AREAS UNTIL THU NGT WHEN THE NEXT WEAK MID
LVL SHORTWAVE VENTURES E/SE ACROSS KS. AS THE ATTENDANT COLD FRONT MOVES
SE ACROSS KS AREAS OF -RA WILL DEVELOP OVER KICT COUNTRY & MAY BE MIXED
WITH -SN IN CNTRL KS LATE THU NGT/EARLY FRI MORNING. AS THE MID-LVL WAVE
VENTURES FURTHER E/SE IT MAY STRENGTHEN. AS SUCH A FEW -TSRA REMAIN
POSSIBLE OVER SE KS ON FRI.
&&
.AVIATION...18Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
TIMING THE ENDING OF IFR STRATUS/FOG THIS AFTERNOON WILL BE THE MAIN
CONCERN...AS SOUTHERLY FLOW HAS ALLOWED SHALLOW GULF MOISTURE TO
MOVE NORTHWARD INTO THE AREA...RESULTING IN ANTICIPATED LOW
STRATUS...WITH SOME PESKY DENSE FOG IN CENTRAL KS. EXPECT THE
DENSE FOG TO SLOWLY BURN OFF ACROSS CEN KS...STRATUS WILL BE SLOW TO
ERODE NORTHEASTWARD THIS AFTERNOON...AS A SURFACE WAVE TRACKS ACROSS
CENTRAL KS AND SLOWLY DRIFTS SOUTHEAST WITH LIGHT/VARIABLE WINDS.
SOUTH CENTRAL KS LOOKS TO BREAK OUT OF LOW CLOUDS BY MIDDAY...WITH
CENTRAL AND SOUTHEAST KS TAKING MUCH OF THE DAY. SO WILL SEE A
GENERAL IMPROVEMENT FROM IFR TO MVFR TO VFR AS THE AFTERNOON
CONTINUES.
WILL CARRY VFR FORECAST AREA WIDE TONIGHT WITH LIGHT WEST
SOUTHWESTERLY WIND COMPONENT.
KETCHAM
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 36 72 55 69 / 0 0 0 10
HUTCHINSON 34 72 53 66 / 0 0 0 10
NEWTON 35 72 55 67 / 0 0 0 10
ELDORADO 36 71 55 69 / 0 0 0 10
WINFIELD-KWLD 38 72 57 71 / 0 0 0 10
RUSSELL 34 72 42 64 / 0 0 0 0
GREAT BEND 33 71 44 65 / 0 0 0 0
SALINA 34 73 50 66 / 0 0 0 0
MCPHERSON 34 72 53 66 / 0 0 0 10
COFFEYVILLE 49 71 59 71 / 0 0 0 20
CHANUTE 43 70 56 70 / 0 0 0 20
IOLA 40 70 56 70 / 0 0 0 20
PARSONS-KPPF 47 71 59 71 / 0 0 0 20
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
136 PM CST SAT DEC 1 2012
...UPDATE TO SHORT TERM DISCUSSION...
.SYNOPSIS...
ISSUED AT 933 AM CST SAT DEC 1 2012
THE 01.12Z 250 HPA MAP SHOWED MOSTLY A ZONAL FLOW ACROSS THE NATION
WITH A FEW SUBTLE WAVES. A 120 KT JET WAS OBSERVED ACROSS SOUTHWESTERN
OREGON. ANOTHER 100 KT JET WAS OBSERVED ACROSS NORTH DAKOTA. AT 500
HPA, A DEEP CYCLONE WAS LOCATED WEST OF BRITISH COLUMBIA WITH AN ASSOCIATED
TROF MOVING ACROSS THE PACIFIC NORTHWEST. ANOTHER TROF WAS MOVING OUT
ACROSS THE PLAINS. MID LEVEL TEMPERATURES WERE MAINLY IN THE NEGATIVE
TEENS/20S WITH -30 DEG C AND BELOW CONFINED TO SE CANADA. AT 700 HPA,
TEMPERATURES INCREASED A FEW DEGREES CENTIGRADE AT KDDC AHEAD OF A WAVE.
AT 850 HPA, A WARM PLUME OF AROUND 18 DEG C PREVAILED ACROSS THE SOUTHERN
AND CENTRAL PLAINS. THE ATMOSPHERE WAS FAIRLY DRY AT THIS CONSTANT PRESSURE
LEVEL AS WELL. THE COLDER AIR OF -15 DEG C AND BELOW WAS CONFINED TO
SE CANADA. AT THE SFC, A STATIONARY BOUNDARY WAS DRAPED ACROSS KANSAS.
RESPECTABLE DEWPOINTS...FOR THE BEGINNING OF DECEMBER...WITH VALUES
RUNNING IN THE 50S DEG F WERE SOUTH OF SAID BOUNDARY ACROSS THE SC/SE
PORTION OF THE STATE.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 136 PM CST SAT DEC 1 2012
TONIGHT:
FAIRLY TRANQUIL CONDITIONS ARE EXPECTED TONIGHT. HIGH LEVEL CLOUDS WILL
MOVE OFF TO THE EAST THIS EVENING AND SKIES SHOULD BE CLEAR THROUGH
THE OVERNIGHT HOURS. BUFKIT FORECAST SOUNDINGS, MOS GUIDANCE, THE VERY
END OF THE HRRR RUN, AND THE NSSL WRF MODEL HIGHLIGHTS A CONCERN FOR PATCHY
FOG TOMORROW MORNING. DEWPOINTS WILL BE LOWER THAN COMPARED TO THIS
MORNING. DRIER AIR WILL ADVECT IN FROM THE NW. STILL, CONSIDERING EVERYTHING
ABOVE, I HAVE INSERTED PATCHY FOG ALONG AND EAST OF HIGHWAY 283. THIS
MIGHT BE ON THE LIBERAL SIDE AND MAY HAVE TO BE TRIMMED FARTHER EAST.
OTHERWISE, LOWS WILL BE MAINLY IN THE 30S DEG F.
TOMORROW:
OTHER THAN THE AFOREMENTIONED FOG AND SOME AFTERNOON CIRRUS, TOMORROW
WILL BE CLEAR WITH FULL INSOLATION. DID NOT CHANGE MAXIMUM TEMPERATURES
FOR TOMORROW AS THE GRID LOOKS STILL ON TRACK WITH 12Z DATA. IT WILL
BE VERY WARM TOMORROW WITH HIGHS AROUND 70 DEG F. THE AVERAGE HIGH FOR
THIS TIME OF YEAR IS AROUND 48 DEG F. THESE WARM TEMPERATURES ARE A
RESULT OF THE DEEPENING OF THE LEE SURFACE TROUGH ACROSS EASTERN COLORADO
AND RESULTANT CONTINUED WARM AIR ADVECTION. 850 HPA TEMPERATURES AROUND
15 DEG C AND ADIABATIC MIXING STILL SUPPORT THE WARM TEMPS AT THE SURFACE.
LASTLY, RH`S LOOK MARGINAL FOR TOMORROW SO NOT EXPECTING ANY FIRE WX
CONCERNS ATTM. IT WILL BE BREEZY TOMORROW, BUT NOTHING OUT OF THE ORDINARY
IN TERMS OF WESTERN KANSAS WIND STANDARDS (GENERALLY 12-21 KT).
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 344 AM CST SAT DEC 1 2012
A PROGRESSIVE ZONAL FLOW REGIME WILL CONTINUE TO DOMINATE THE
CENTRAL PLAINS ON SUNDAY. FURTHER, THIS WILL OCCUR WHILE A POTENT
120 KT EAST PACIFIC JET, BEGINS TO CARVE OUT A TROUGH OVER THE
PACIFIC NORTHWEST SUNDAY AFTERNOON TO EVENING. MODEST WEST TO
EAST MID/UPPER FLOW OVER THE ROCKIES, WILL AID IN SLOWLY DEEPENING
THE LEE TROUGH IN THE WESTERN HIGH PLAINS OF COLORADO ON SUNDAY.
THIS WILL RESULT IN WARM SOUTH TO SOUTHEAST WINDS PREVAILING AHEAD
OF THE TROUGH ON SUNDAY AS 850 HPA TEMPERATURES OF +12C TO +15C
EXIST OVER SOUTHWEST INTO CENTRAL KANSAS. HOWEVER, SOME CIRRUS
STREAMING OFF THE ROCKIES MAY SLIGHTLY LIMIT SOLAR INSOLATION/MIXING
ON SUNDAY BUT HIGHS IN THE UPPER 60S TO MID 70S STILL LOOK LIKELY.
THE PATTERN THEN BEGINS TO CHANGE SUNDAY NIGHT INTO MONDAY AS THE
AFOREMENTIONED UPPER JET AND ASSOCIATED TROUGH, SLIDE VERY QUICKLY
EAST INTO THE PLAINS. IN RESPONSE TO THIS WAVE, A FAST MOVING
PACIFIC FRONT WILL PUSH THROUGH SOUTHWEST INTO CENTRAL KANSAS MONDAY
MORNING TO EARLY AFTERNOON. ALTHOUGH THIS FRONTAL PASSAGE WILL
RESULT IN LITTLE IF ANY THREAT FOR PRECIPITATION, WIND SPEEDS ARE A
DIFFERENT MATTER. A MODEST 3 HOUR PRESSURE RISE BEHIND THE BOUNDARY
WILL PRODUCE AN ISALLOBARIC RESPONSE IN THE WIND FIELD WITH NORTH
WINDS OF 25 TO 30 MPH POSSIBLE THROUGH MID AFTERNOON ON MONDAY.
TEMPERATURES WILL BE TRICKY ON MONDAY GIVEN THE FRONTAL PASSAGE
AFTER SUNRISE BUT BEFORE PEAK HEATING. WILL AIM FOR HIGHS IN THE
LOWER 60S NEAR WAKEENEY...TO THE UPPER 60S NEAR THE OKLAHOMA BORDER.
TUESDAY WILL REMAIN DRY YET MILD FOR EARLY DECEMBER AS THE UPPER
TROUGH SWINGS EAST OF THE PLAINS WHILE ARCTIC AIR DIGS INTO THE
GREAT LAKES REGION. INCREASING ZONAL MID LEVEL FLOW OVER THE CENTRAL
ROCKIES WILL BEGIN TO DEEPEN THE LEE TROUGH BY TUESDAY AFTERNOON
WITH WINDS TURNING MORE SOUTHERLY AS THERMAL MIXING UP TO 850 HPA
SUPPORTS HIGHS IN THE UPPER 50S TO LOWER 60S.
WEDNESDAY INTO EARLY THURSDAY WILL BE A TRANSITIONAL PERIOD BETWEEN
THE EXITING WAVE FROM MONDAY AND THE NEXT TROUGH MOVING INTO THE
PLAINS BY LATE THURSDAY. THE LEE TROUGH WILL CONTINUE TO DEEPEN
DURING THIS TIME PERIOD WITH WARM SOUTHERLY WINDS PUSHING 850 HPA
TEMPERATURES INTO THE +10 TO +15C RANGE. THIS WILL SUPPORT A
COUPLE MORE DAYS OF MILD HIGH TEMPERATURES IN THE UPPER 50S TO
60S.
ATTENTION THEN TURNS TOWARD THE LATTER HALF OF THURSDAY INTO FRIDAY
AS AN OPEN BUT STRONG UPPER WAVE SLIDES THROUGH PLAINS. THIS SYSTEM
WILL PUSH A POTENT COLD FRONT WITH SOME ARCTIC AIR BEHIND IT,
THROUGH KANSAS BY THURSDAY EVENING. FURTHER, ALTHOUGH THE WAVE WILL
REMAIN OPEN, FAVORABLE JET DYNAMICS MAY BRING A LOWER END CHANCE
FOR SOME LIGHT PRECIPITATION LATE THURSDAY INTO EARLY FRIDAY
BEFORE SUBSIDENCE TAKES HOLD OF THE AREA FRIDAY AFTERNOON.
OTHERWISE, TEMPERATURES WILL COOL SUBSTANTIALLY BEHIND THE FRONT WITH
HIGH TEMPERATURES IN THE 40S TO NEAR 50 EXPECTED FRIDAY AND
SATURDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1100 AM CST SAT DEC 1 2012
CIGS ARE IMPROVING TO VFR THIS MORNING AS FOG DISSIPATES. MOS GUIDANCE
AND BUFKIT PROFILES SUGGEST FOG IS POSSIBLE AGAIN TOMORROW MORNING.
THIS FOG SHOULD NOT BE AS DENSE AS DRIER AIR ADVECTS IN FROM THE NORTHWEST.
WILL GO AHEAD AND HEDGE TO MVFR FOR KDDC/KHYS AND LET FUTURE SHIFTS ADJUST
AS NEEDED FOR TOMORROW AM.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 34 71 41 66 / 0 0 0 0
GCK 33 71 37 64 / 0 0 0 0
EHA 39 72 40 65 / 0 0 0 0
LBL 36 73 36 66 / 0 0 0 0
HYS 34 71 38 63 / 0 0 0 0
P28 36 73 47 69 / 0 0 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM...AJOHNSON
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1122 AM CST SAT DEC 1 2012
...UPDATE TO AVIATION...
.UPDATE...
AFTER CALLING NUMEROUS SPOTTERS ACROSS THE OBSERVATION- SPARSE
REGIONS OF NORTH CENTRAL AND NORTHEAST KANSAS...HAVE CONCLUDED
THAT DENSE FOG CONTINUES IN FULL EFFECT NEAR AND NORTHWEST OF A
LINE FROM MINNEAPOLIS TO CLAY CENTER TO WASHINGTON. VISIBILITY IN
THESE AREAS RANGED FROM AROUND 100 FEET TO AROUND ONE QUARTER
MILE. VISIBILITY HAD GRADUALLY IMPROVED SOUTHEAST OF THIS LINE AND
SHOULD CONTINUE TO DO SO...WITH VISIBILITY RANGING FROM ONE
QUARTER TO 2 MILES SOUTHEAST OF THE LINE...AND IMPROVING
FURTHERMORE NEAR AND SOUTH OF I-70 AND WEST OF ABILENE. WITH THIS
IN MIND...HAVE ALLOWED THE ADVISORY TO EXPIRE FOR MARSHALL AND
DICKINSON COUNTIES...WHILE EXTENDING IT UNTIL NOON FOR POINTS
FURTHER NORTHWEST. THERE IS SOME POTENTIAL FOR THE DENSE FOG TO
CONTINUE PAST NOON IN THE CONCORDIA AND BELLEVILLE AREAS AND WILL
CONTINUE TO EVALUATE THIS AS THE MORNING GOES ON.
BARJENBRUCH
&&
.DISCUSSION...
QUICK LOW LEVEL SOUTHERLY FLOW WITH 925MB WINDS AROUND 30KT
BRINGING MOISTURE UNDER INVERSION NOTED ON KTOP 0Z SOUNDING. WITH
LIGHT SURFACE WINDS NEAR THE OLD BOUNDARY IN NORTHERN KANSAS AND
SOME BREAKS IN THE CIRRUS...TEMPS COOLED SUFFICIENTLY FOR THE
MOISTURE TO RESULT IN WIDESPREAD LOW CLOUDS. RECENT HOURS HAVE
SEEN DEWPOINTS RISE RATHER SHARPLY AND RESULTING IN DENSE FOG FOR
MUCH OF THE WESTERN HALF OF THE CWA. LAST FEW OBSERVATIONS IN
SOUTH CENTRAL AND SOUTHEAST KANSAS INDICATE RISING VISIBILITIES
AND CLOUD DECKS AND CONFIDENCE IN HOW LONG THE DENSE FOG WILL LAST
IS NOT HIGH....BUT AT LEAST THROUGH POST-SUNRISE SEEMS IN ORDER.
08Z 3-HOUR PRESSURE TRENDS HAVE BEST FALLS IN SOUTHWEST KANSAS
EAST OF A SURFACE LOW. THIS LOW IS PROGGED TO PUSH EAST IN THE
ZONAL FLOW ALOFT...WITH MODERATE CONVERGENCE RESULTING TODAY FOR
NORTHERN KANSAS. UNDER SOMEWHAT VEERED WINDS JUST ABOVE IT...THERE
MAY BE ENOUGH MOISTURE CONVERGENCE FOR SOME DRIZZLE TO BE SQUEEZED
OUT OF THE MOIST LOWER FEW THOUSAND FEET. MOST RECENT
SREF...NAM...AND RAP SUGGEST LOW CLOUDS WILL BE SLOWER TO CLEAR ON
THE NORTHWEST SIDE OF THE LOW AND HAVE COOLED HIGHS SEVERAL
DEGREES AS A RESULT. INCREASING WESTERLY FLOW BEHIND THE LOW
SHOULD ALLOW FOR CLEARING AND DRYING CONDITIONS BY EARLY EVENING.
SUNDAY LOOKING RATHER WARM WITH 850MB TEMPS IN THE 12-14C RANGE.
AFTER WEAK SURFACE RIDGING BUILDS IN TONIGHT...WINDS WILL BE RATHER
LIGHT FOR MUCH OF THE DAY...THOUGH SOUTH WINDS AND CIRRUS WILL BE
INCREASING IN THE AFTERNOON AS AN UPPER WAVE MAKES EASTWARD PROGRESS
OVER THE NORTHERN ROCKIES. BELIEVE MIXING WILL STILL NOT BE HARD TO
MANAGE IN THE RATHER DRY LOWER TROPOSPHERE AND NEAR RECORD TEMPS
STILL ON TRACK.
SUNDAY NIGHT INTO MONDAY ARE SHOWING SIMILARITIES TO CURRENT AND
NEAR FUTURE EXPECTATIONS WITH THE LOW LEVELS MOISTENING AGAIN.
RISING TEMPS AND FOG CHANCES PRESENT THEMSELVES BUT MUCH TO EARLY
TO GET TOO CONCERNED. FRONTAL PASSAGE WITH THE NORTHERN WAVE STILL
ON TRACK FOR MONDAY...BUT STOUTNESS OF THE INVERSION IS STARTING
TO LOOK TOO STRONG FOR PRECIP AGAIN...AND DRIZZLE COULD AGAIN BE
THE PRIMARY WEATHER. WILL BEGIN TO TAPER PRECIP COVERAGE ON THE
NORTHERN AND WESTERN ENDS AT THIS POINT. FRONT STILL NOT TAPPING
INTO A SIGNIFICANTLY COOLER AIRMASS AND TEMPS ONLY DROP SOME 10
DEGREES FROM EARLIER DAYS.
NEXT FRONT STILL ON TRACK FOR THE THURSDAY/THURSDAY NIGHT PERIODS
WITH BROAD UPPER TROFFING MOVING THROUGH INTO FRIDAY. DEEP LAYER
SATURATION IS BETTER BUT STILL NOT IDEAL FOR WIDESPREAD
PRECIPITATION. COOLER AIR DOES MAKE ITS WAY SOUTH FOR EVEN SOME
FROZEN PRECIP POTENTIAL. SMALL CHANCES WILL BE MAINTAINED AT THIS
POINT.
65
&&
.AVIATION...
WHILE CONDITIONS SINCE 15Z HAVE BOUNCED BETWEEN VFR AND MVFR
CIGS...EXPECT PREDOMINANT MVFR CIGS AT ALL TAF SITES WITH TEMPO
VFR THROUGH 20Z. DRY AIR MOVES IN BETWEEN 23Z AND 01Z AND SHOULD
SCATTER STRATUS OUT. TIMING OF SCATTERING MAY VARY BY A FEW HOURS
WITH TAFS INDICATING MOST LIKELY SCENARIO. CLEARING SKIES OVER
THE MOIST AIRMASS SHOULD LEAD TO FOG REDEVELOPMENT BY LATE EVENING
OR EARLY MORNING HOURS. HAVE GONE WITH SEVERAL HOURS OF MVFR AND
IFR VIS FOR SUNDAY MORNING...BUT CONFIDENCE IS NOT PARTICULARLY
HIGH REGARDING EXTENT OF FOG...AND COULD SEE CONDITIONS RANGING
FROM VFR TO VLIFR AT TAF SITES BY SUNRISE.
BARJENBRUCH
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL NOON CST TODAY FOR KSZ008-009-020-021-
034.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1007 AM CST SAT DEC 1 2012
.UPDATE...
...UPDATE FOR DENSE FOG FORECAST...
AFTER CALLING NUMEROUS SPOTTERS ACROSS THE OBSERVATION- SPARSE
REGIONS OF NORTH CENTRAL AND NORTHEAST KANSAS...HAVE CONCLUDED
THAT DENSE FOG CONTINUES IN FULL EFFECT NEAR AND NORTHWEST OF A
LINE FROM MINNEAPOLIS TO CLAY CENTER TO WASHINGTON. VISIBILITY IN
THESE AREAS RANGED FROM AROUND 100 FEET TO AROUND ONE QUARTER
MILE. VISIBILITY HAD GRADUALLY IMPROVED SOUTHEAST OF THIS LINE AND
SHOULD CONTINUE TO DO SO...WITH VISIBILITY RANGING FROM ONE
QUARTER TO 2 MILES SOUTHEAST OF THE LINE...AND IMPROVING
FURTHERMORE NEAR AND SOUTH OF I-70 AND WEST OF ABILENE. WITH THIS
IN MIND...HAVE ALLOWED THE ADVISORY TO EXPIRE FOR MARSHALL AND
DICKINSON COUNTIES...WHILE EXTENDING IT UNTIL NOON FOR POINTS
FURTHER NORTHWEST. THERE IS SOME POTENTIAL FOR THE DENSE FOG TO
CONTINUE PAST NOON IN THE CONCORDIA AND BELLEVILLE AREAS AND WILL
CONTINUE TO EVALUATE THIS AS THE MORNING GOES ON.
BARJENBRUCH
&&
.DISCUSSION...
QUICK LOW LEVEL SOUTHERLY FLOW WITH 925MB WINDS AROUND 30KT
BRINGING MOISTURE UNDER INVERSION NOTED ON KTOP 0Z SOUNDING. WITH
LIGHT SURFACE WINDS NEAR THE OLD BOUNDARY IN NORTHERN KANSAS AND
SOME BREAKS IN THE CIRRUS...TEMPS COOLED SUFFICIENTLY FOR THE
MOISTURE TO RESULT IN WIDESPREAD LOW CLOUDS. RECENT HOURS HAVE
SEEN DEWPOINTS RISE RATHER SHARPLY AND RESULTING IN DENSE FOG FOR
MUCH OF THE WESTERN HALF OF THE CWA. LAST FEW OBSERVATIONS IN
SOUTH CENTRAL AND SOUTHEAST KANSAS INDICATE RISING VISIBILITIES
AND CLOUD DECKS AND CONFIDENCE IN HOW LONG THE DENSE FOG WILL LAST
IS NOT HIGH....BUT AT LEAST THROUGH POST-SUNRISE SEEMS IN ORDER.
08Z 3-HOUR PRESSURE TRENDS HAVE BEST FALLS IN SOUTHWEST KANSAS
EAST OF A SURFACE LOW. THIS LOW IS PROGGED TO PUSH EAST IN THE
ZONAL FLOW ALOFT...WITH MODERATE CONVERGENCE RESULTING TODAY FOR
NORTHERN KANSAS. UNDER SOMEWHAT VEERED WINDS JUST ABOVE IT...THERE
MAY BE ENOUGH MOISTURE CONVERGENCE FOR SOME DRIZZLE TO BE SQUEEZED
OUT OF THE MOIST LOWER FEW THOUSAND FEET. MOST RECENT
SREF...NAM...AND RAP SUGGEST LOW CLOUDS WILL BE SLOWER TO CLEAR ON
THE NORTHWEST SIDE OF THE LOW AND HAVE COOLED HIGHS SEVERAL
DEGREES AS A RESULT. INCREASING WESTERLY FLOW BEHIND THE LOW
SHOULD ALLOW FOR CLEARING AND DRYING CONDITIONS BY EARLY EVENING.
SUNDAY LOOKING RATHER WARM WITH 850MB TEMPS IN THE 12-14C RANGE.
AFTER WEAK SURFACE RIDGING BUILDS IN TONIGHT...WINDS WILL BE RATHER
LIGHT FOR MUCH OF THE DAY...THOUGH SOUTH WINDS AND CIRRUS WILL BE
INCREASING IN THE AFTERNOON AS AN UPPER WAVE MAKES EASTWARD PROGRESS
OVER THE NORTHERN ROCKIES. BELIEVE MIXING WILL STILL NOT BE HARD TO
MANAGE IN THE RATHER DRY LOWER TROPOSPHERE AND NEAR RECORD TEMPS
STILL ON TRACK.
SUNDAY NIGHT INTO MONDAY ARE SHOWING SIMILARITIES TO CURRENT AND
NEAR FUTURE EXPECTATIONS WITH THE LOW LEVELS MOISTENING AGAIN.
RISING TEMPS AND FOG CHANCES PRESENT THEMSELVES BUT MUCH TO EARLY
TO GET TOO CONCERNED. FRONTAL PASSAGE WITH THE NORTHERN WAVE STILL
ON TRACK FOR MONDAY...BUT STOUTNESS OF THE INVERSION IS STARTING
TO LOOK TOO STRONG FOR PRECIP AGAIN...AND DRIZZLE COULD AGAIN BE
THE PRIMARY WEATHER. WILL BEGIN TO TAPER PRECIP COVERAGE ON THE
NORTHERN AND WESTERN ENDS AT THIS POINT. FRONT STILL NOT TAPPING
INTO A SIGNIFICANTLY COOLER AIRMASS AND TEMPS ONLY DROP SOME 10
DEGREES FROM EARLIER DAYS.
NEXT FRONT STILL ON TRACK FOR THE THURSDAY/THURSDAY NIGHT PERIODS
WITH BROAD UPPER TROFFING MOVING THROUGH INTO FRIDAY. DEEP LAYER
SATURATION IS BETTER BUT STILL NOT IDEAL FOR WIDESPREAD
PRECIPITATION. COOLER AIR DOES MAKE ITS WAY SOUTH FOR EVEN SOME
FROZEN PRECIP POTENTIAL. SMALL CHANCES WILL BE MAINTAINED AT THIS
POINT.
65
&&
.AVIATION...
IFR TO MVFR CIGS WILL CONTINUE INTO THE LATE MORNING HOURS. MVFR
CIGS ARE EXPECTED BY 18Z. LOW LEVEL MOISTURE WILL BE SLOW TO MOVE
OUT SO KEPT MVFR CIGS IN UNTIL 23Z-24Z. WINDS WILL BE SOUTH NEAR
10 KTS VEERING TO THE SOUTHWEST AND DECREASING BY 00Z SUNDAY.
53
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL NOON CST TODAY FOR KSZ008-009-020-021-
034.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
542 AM CST SAT DEC 1 2012
...UPDATE TO AVIATION...
.DISCUSSION...
QUICK LOW LEVEL SOUTHERLY FLOW WITH 925MB WINDS AROUND 30KT
BRINGING MOISTURE UNDER INVERSION NOTED ON KTOP 0Z SOUNDING. WITH
LIGHT SURFACE WINDS NEAR THE OLD BOUNDARY IN NORTHERN KANSAS AND
SOME BREAKS IN THE CIRRUS...TEMPS COOLED SUFFICIENTLY FOR THE
MOISTURE TO RESULT IN WIDESPREAD LOW CLOUDS. RECENT HOURS HAVE
SEEN DEWPOINTS RISE RATHER SHARPLY AND RESULTING IN DENSE FOG FOR
MUCH OF THE WESTERN HALF OF THE CWA. LAST FEW OBSERVATIONS IN
SOUTH CENTRAL AND SOUTHEAST KANSAS INDICATE RISING VISIBILITIES
AND CLOUD DECKS AND CONFIDENCE IN HOW LONG THE DENSE FOG WILL LAST
IS NOT HIGH....BUT AT LEAST THROUGH POST-SUNRISE SEEMS IN ORDER.
08Z 3-HOUR PRESSURE TRENDS HAVE BEST FALLS IN SOUTHWEST KANSAS
EAST OF A SURFACE LOW. THIS LOW IS PROGGED TO PUSH EAST IN THE
ZONAL FLOW ALOFT...WITH MODERATE CONVERGENCE RESULTING TODAY FOR
NORTHERN KANSAS. UNDER SOMEWHAT VEERED WINDS JUST ABOVE IT...THERE
MAY BE ENOUGH MOISTURE CONVERGENCE FOR SOME DRIZZLE TO BE SQUEEZED
OUT OF THE MOIST LOWER FEW THOUSAND FEET. MOST RECENT
SREF...NAM...AND RAP SUGGEST LOW CLOUDS WILL BE SLOWER TO CLEAR ON
THE NORTHWEST SIDE OF THE LOW AND HAVE COOLED HIGHS SEVERAL
DEGREES AS A RESULT. INCREASING WESTERLY FLOW BEHIND THE LOW
SHOULD ALLOW FOR CLEARING AND DRYING CONDITIONS BY EARLY EVENING.
SUNDAY LOOKING RATHER WARM WITH 850MB TEMPS IN THE 12-14C RANGE.
AFTER WEAK SURFACE RIDGING BUILDS IN TONIGHT...WINDS WILL BE RATHER
LIGHT FOR MUCH OF THE DAY...THOUGH SOUTH WINDS AND CIRRUS WILL BE
INCREASING IN THE AFTERNOON AS AN UPPER WAVE MAKES EASTWARD PROGRESS
OVER THE NORTHERN ROCKIES. BELIEVE MIXING WILL STILL NOT BE HARD TO
MANAGE IN THE RATHER DRY LOWER TROPOSPHERE AND NEAR RECORD TEMPS
STILL ON TRACK.
SUNDAY NIGHT INTO MONDAY ARE SHOWING SIMILARITIES TO CURRENT AND
NEAR FUTURE EXPECTATIONS WITH THE LOW LEVELS MOISTENING AGAIN.
RISING TEMPS AND FOG CHANCES PRESENT THEMSELVES BUT MUCH TO EARLY
TO GET TOO CONCERNED. FRONTAL PASSAGE WITH THE NORTHERN WAVE STILL
ON TRACK FOR MONDAY...BUT STOUTNESS OF THE INVERSION IS STARTING
TO LOOK TOO STRONG FOR PRECIP AGAIN...AND DRIZZLE COULD AGAIN BE
THE PRIMARY WEATHER. WILL BEGIN TO TAPER PRECIP COVERAGE ON THE
NORTHERN AND WESTERN ENDS AT THIS POINT. FRONT STILL NOT TAPPING
INTO A SIGNIFICANTLY COOLER AIRMASS AND TEMPS ONLY DROP SOME 10
DEGREES FROM EARLIER DAYS.
NEXT FRONT STILL ON TRACK FOR THE THURSDAY/THURSDAY NIGHT PERIODS
WITH BROAD UPPER TROFFING MOVING THROUGH INTO FRIDAY. DEEP LAYER
SATURATION IS BETTER BUT STILL NOT IDEAL FOR WIDESPREAD
PRECIPITATION. COOLER AIR DOES MAKE ITS WAY SOUTH FOR EVEN SOME
FROZEN PRECIP POTENTIAL. SMALL CHANCES WILL BE MAINTAINED AT THIS
POINT.
65
&&
.AVIATION...
IFR TO MVFR CIGS WILL CONTINUE INTO THE LATE MORNING HOURS. MVFR
CIGS ARE EXPECTED BY 18Z. LOW LEVEL MOISTURE WILL BE SLOW TO MOVE
OUT SO KEPT MVFR CIGS IN UNTIL 23Z-24Z. WINDS WILL BE SOUTH NEAR
10 KTS VEERING TO THE SOUTHWEST AND DECREASING BY 00Z SUNDAY.
53
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR
KSZ008>010-020-021-034-035.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
345 AM CST SAT DEC 1 2012
.DISCUSSION...
QUICK LOW LEVEL SOUTHERLY FLOW WITH 925MB WINDS AROUND 30KT
BRINGING MOISTURE UNDER INVERSION NOTED ON KTOP 0Z SOUNDING. WITH
LIGHT SURFACE WINDS NEAR THE OLD BOUNDARY IN NORTHERN KANSAS AND
SOME BREAKS IN THE CIRRUS...TEMPS COOLED SUFFICIENTLY FOR THE
MOISTURE TO RESULT IN WIDESPREAD LOW CLOUDS. RECENT HOURS HAVE
SEEN DEWPOINTS RISE RATHER SHARPLY AND RESULTING IN DENSE FOG FOR
MUCH OF THE WESTERN HALF OF THE CWA. LAST FEW OBSERVATIONS IN
SOUTH CENTRAL AND SOUTHEAST KANSAS INDICATE RISING VISIBILITIES
AND CLOUD DECKS AND CONFIDENCE IN HOW LONG THE DENSE FOG WILL LAST
IS NOT HIGH....BUT AT LEAST THROUGH POST-SUNRISE SEEMS IN ORDER.
08Z 3-HOUR PRESSURE TRENDS HAVE BEST FALLS IN SOUTHWEST KANSAS
EAST OF A SURFACE LOW. THIS LOW IS PROGGED TO PUSH EAST IN THE
ZONAL FLOW ALOFT...WITH MODERATE CONVERGENCE RESULTING TODAY FOR
NORTHERN KANSAS. UNDER SOMEWHAT VEERED WINDS JUST ABOVE IT...THERE
MAY BE ENOUGH MOISTURE CONVERGENCE FOR SOME DRIZZLE TO BE SQUEEZED
OUT OF THE MOIST LOWER FEW THOUSAND FEET. MOST RECENT
SREF...NAM...AND RAP SUGGEST LOW CLOUDS WILL BE SLOWER TO CLEAR ON
THE NORTHWEST SIDE OF THE LOW AND HAVE COOLED HIGHS SEVERAL
DEGREES AS A RESULT. INCREASING WESTERLY FLOW BEHIND THE LOW
SHOULD ALLOW FOR CLEARING AND DRYING CONDITIONS BY EARLY EVENING.
SUNDAY LOOKING RATHER WARM WITH 850MB TEMPS IN THE 12-14C RANGE.
AFTER WEAK SURFACE RIDGING BUILDS IN TONIGHT...WINDS WILL BE RATHER
LIGHT FOR MUCH OF THE DAY...THOUGH SOUTH WINDS AND CIRRUS WILL BE
INCREASING IN THE AFTERNOON AS AN UPPER WAVE MAKES EASTWARD PROGRESS
OVER THE NORTHERN ROCKIES. BELIEVE MIXING WILL STILL NOT BE HARD TO
MANAGE IN THE RATHER DRY LOWER TROPOSPHERE AND NEAR RECORD TEMPS
STILL ON TRACK.
SUNDAY NIGHT INTO MONDAY ARE SHOWING SIMILARITIES TO CURRENT AND
NEAR FUTURE EXPECTATIONS WITH THE LOW LEVELS MOISTENING AGAIN.
RISING TEMPS AND FOG CHANCES PRESENT THEMSELVES BUT MUCH TO EARLY
TO GET TOO CONCERNED. FRONTAL PASSAGE WITH THE NORTHERN WAVE STILL
ON TRACK FOR MONDAY...BUT STOUTNESS OF THE INVERSION IS STARTING
TO LOOK TOO STRONG FOR PRECIP AGAIN...AND DRIZZLE COULD AGAIN BE
THE PRIMARY WEATHER. WILL BEGIN TO TAPER PRECIP COVERAGE ON THE
NORTHERN AND WESTERN ENDS AT THIS POINT. FRONT STILL NOT TAPPING
INTO A SIGNIFICANTLY COOLER AIRMASS AND TEMPS ONLY DROP SOME 10
DEGREES FROM EARLIER DAYS.
NEXT FRONT STILL ON TRACK FOR THE THURSDAY/THURSDAY NIGHT PERIODS
WITH BROAD UPPER TROFFING MOVING THROUGH INTO FRIDAY. DEEP LAYER
SATURATION IS BETTER BUT STILL NOT IDEAL FOR WIDESPREAD
PRECIPITATION. COOLER AIR DOES MAKE ITS WAY SOUTH FOR EVEN SOME
FROZEN PRECIP POTENTIAL. SMALL CHANCES WILL BE MAINTAINED AT THIS
POINT.
65
&&
.AVIATION...
MVFR/IFR STRATUS WILL CONTINUE TO DEVELOP WITH LIFR CIGS/VSBYS IN
FOG BY 09Z AT ALL TERMINALS. GRADUAL VEERING LLVL FLOW WITH
DECREASING WAA/MOISTURE ADVECTION WILL ALLOW CIGS/VSBYS TO SLOWLY
IMPROVE BEYOND 15-17Z TIME FRAME. VFR STRATOCU EXPECTED BY 20Z AS
SUBSIDENCE AND DRYING ADVECT EASTWARD IN THE WAKE OF THE DEPARTING
SHORTWAVE TROUGH.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR KSZ008>010-
020-021-034-035.
&&
$$
AREA FORECAST DISCUSSION...CORRECTED
NWS DODGE CITY KS
209 AM CST SAT DEC 1 2012
...UPDATED SHORT TERM DISCUSSION...
.SYNOPSIS...
ISSUED AT 1109 PM CST FRI NOV 30 2012
AT 00Z SATURDAY AN UPPER LEVEL LOW WAS LOCATED OFF THE WEST COAST
OF BRITISH COLUMBIA. ONE UPPER LEVEL DISTURBANCE WAS LOCATED NEAR
THE BASED OF THE UPPER LOW, JUST OFF THE COAST OF THE PACIFIC
NORTHWEST. ANOTHER UPPER LEVEL TROUGH APPEARS TO EXTEND FROM
EXTREME NORTHWEST NEVADA INTO EAST CENTRAL CALIFORNIA. WEAK 500MB
RIDGING WAS PRESENT ACROSS THE ROCKIES. AT THE 700MB LEVEL A +4C
TO +8C RIDGE OF WARM AIR EXTENDED FROM WEST TEXAS NORTHWARD ALONG
THE LEE OF THE ROCKIES INTO EASTERN WYOMING/SOUTHWEST SOUTH
DAKOTA. AT THE 850MB LEVEL A WARM LEE TROUGH STRETCHED FROM
WESTERN NORTH DAKOTA INTO EASTERN ARIZONA. THE 850MB TEMPERATURE
AT AMARILLO AT 00Z SATURDAY WAS 18C, DODGE CITY AND RAPID CITY
HAD A 850MB TEMPERATURE OF +12. 850MB MOISTURE APPEARED TO BE
PRIMARILY CONFINED TO NORTH CENTRAL OKLAHOMA. AT THE SURFACE
EARLIER THIS EVENING A MOIST SOUTHEAST UPSLOPE FLOW HAD DEVELOPED
ACROSS WESTERN KANSAS. DEWPOINTS ACROSS NORTH CENTRAL OKLAHOMA
WERE IN THE LOWER 50S AND AS OF 04Z FOG HAD ALREADY DEVELOPED
ACROSS SOUTH CENTRAL AND PORTIONS OF WESTERN KANSAS.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 204 AM CST SAT DEC 1 2012
A SHALLOW LAYER OF LOW LEVEL MOISTURE WAS STREAMING NORTHWARD
ACROSS CENTRAL KANSAS EARLIER THIS MORNING. AS OF 6Z SEVERAL SITES
IN SOUTH CENTRAL KANSAS REPORTED VISIBILITIES OF A 1/4 MILE. PHONE
CALLS TO THESE AREAS REVEALED THERE WERE ALSO SEVERAL OTHER
LOCATIONS WHERE VISIBILITIES WERE LOWER THAN THIS. AS A RESULT A
DENSE FOG ADVISORY WAS ISSUED ALONG AND NEAR A LINE FROM ROUGHLY
WAKEENEY TO LARNED TO PRATT AND MEDICINE LODGE. THIS WAS WHERE
UPSLOPE FLOW AND BETTER MOISTURE WAS LOCATED. VISIBILITIES WILL
BEGIN TO IMPROVE LATER THIS MORNING AS SOUTHEAST WINDS VEER MORE
TO THE SOUTHWEST, HOWEVER SOME MID TO HIGH LEVEL MOISTURE
PRECEDING A WESTERN UNITED STATES UPPER LEVEL TROUGH MAY LIMIT HOW
QUICKLY THE SHALLOW LOW LEVEL STATUS/FOG WILL ERODE. AT THIS TIME
BASED ON THE NAM, NMM, AND ARW THE SURFACE WINDS WILL BECOME MORE
SOUTHWESTERLY AFTER 12Z SO VISIBILITIES ARE EXPECTED TO BEGIN TO
IMPROVE AROUND DAYBREAK. EARLY MORNING CLOUDS WILL EVENTUALLY GIVE
WAY TO SUNNY SKIES AS THE UPPER LEVEL TROUGH CROSSES WESTERN
KANSAS. MORE CLOUDS THAN SUN HOWEVER WILL BE POSSIBLE DURING THE
EARLY AFTERNOON IN NORTH CENTRAL KANSAS WHICH SHOULD AID IN
KEEPING HIGHS TODAY SLIGHTLY COOLER THAN WHAT THE 850MB MIXDOWN
TEMPERATURES WOULD SUGGEST. WILL THEREFORE STAY CLOSE TO THE
COOLER GUIDANCE FORECAST OF MID 60S FOR HIGHS IN NORTH CENTRAL
KANSAS. FURTHER SOUTHWEST WILL TREND MORE TOWARDS THE WARMER
MIXDOWN TEMPERATURES FROM THE 00Z NAM GIVEN BETTER INSOLATION.
TONIGHT SKIES WILL BE CLEAR AS WINDS DECREASE TO 10MPH OR LESS.
WITH DEWPOINT FORECAST TO BE IN THE LOW TO MID 30S THE LATEST
MET/MAV GUIDANCE APPEARS REASONABLE WITH LOWS HOVERING MAINLY IN
THE 32 TO 38 DEGREE RANGE.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 245 PM CST FRI NOV 30 2012
BEYOND THE WEEKEND, THE LARGE SCALE SYNOPTIC PATTERN BECOMES
CONSIDERABLY MORE ACTIVE ACROSS THE WESTERN TWO THURSDAY OF THE
COUNTRY. THIS WILL NOT HOWEVER BRING A HIGH PROBABILITY OF
PRECIPITATION, HOWEVER, THE ODDS WILL INCREASE BY FRIDAY.
A ZONAL PATTERN WILL STILL BE FOUND ACROSS THE CENTRAL PLAINS
SATURDAY AND INTO SUNDAY, WITH THE POLAR JET DISPLACED FARTHER NORTH
ACROSS THE NORTHERN PLAINS. THIS PATTERN WILL AID IN MAINTAINING
LIGHT SOUTHERLY SURFACE WINDS, AS WELL AS WARMER THAN NORMAL HIGHS
IN THE 60`S, TO NEAR 70 DEGREES ON SUNDAY. A FAST MOVING STRONG
SHORTWAVE TROUGH ASSOCIATED WITH A STRONG EASTERN PACIFIC JET WILL
MOVE RAPIDLY EAST ACROSS THE COLORADO PLATEAU INTO THE HIGH PLAINS
REGION BY SUNDAY NIGHT. IMPRESSIVE SURFACE PRESSURE FALLS WILL TAKE
PLACE ACROSS THE CENTRAL AND NORTHERN HIGH PLAINS REGIONS SUNDAY
NIGHT, DEVELOPING LEE TROUGHING FROM NEW MEXICO INTO MONTANA. THE
MODELS THEN SHOVE A PACIFIC COLD FRONT ACROSS WESTERN KANSAS MONDAY
MORNING. THE COLD FRONT IS NOT EXPECTED TO BE PARTICULARLY STRONG,
BUT GFS AND IT`S MOS SUGGEST WIND SPEEDS BETWEEN 20 AND 25 KNOTS
DURING THE LATE MORNING AND AFTERNOON. WINDS SHOULD RAPIDLY
DECOUPLE, AND THE GRADIENT SHOULD SLACKEN CONSIDERABLY IN THE
EVENING TO ALLOW WINDS SPEED TO DECREASE TO AROUND 12 KNOTS OR LESS.
TEMPERATURES FOR MONDAY NIGHT WERE ADJUSTED TO COINCIDE CLOSER TO A
MOS CONSENSUS RATHER THAN THE WARM BIASED RAW MODELS. SURFACE HIGH
PRESSURE SHOULD HAVE AN IMPACT ON TUESDAY HIGHS. TEMPERATURES WILL
STRUGGLE THROUGH THE 50`S TUESDAY AFTERNOON AS COOL HIGH PRESSURE
CONTINUES TO PROMOTE LIGHT WINDS WITH NO SIGNIFICANT DOWNSLOPE
EFFECT. A REBOUND IN TEMPERATURES (ALBEIT SLIGHT) IS EXPECTED ONCE
AGAIN ON WEDNESDAY AS 500 MB HEIGHTS INCREASE AND THE BOUNDARY LAYER
SEES A RETURN TO SOUTHERLY WINDS. THE MODELS SUPPORT A BROAD TROUGH
MOVING ACROSS THE WESTERN UNITED STATES DURING THIS PERIOD. THE GFS
AND ECMWF HAVE DISTINCTLY DIFFERENT SOLUTIONS IN THE THERMODYNAMIC
FIELDS BY AROUND 180 HOURS. THE GFS ALLOWS THE SLUG OF VERY COLD
-20 TO -30 DEGREE C AIR AT 500 MB AIR TO SWING FARTHER SOUTH ACROSS
THE SOUTHERN CENTRAL HIGH PLAINS. THIS MORE AMPLIFIED PATTERN BETTER
SUPPORTS A DEEP UNSTABLE LAYER IN THIS TIME FRAME, AS WELL AS A
DEEPER DENDRITIC GROWTH POTENTIAL FOR SNOW ACROSS EASTERN COLORADO
AND WESTERN KANSAS AS EARLY AS FRIDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1109 PM CST FRI NOV 30 2012
A MOIST SOUTHEAST UPSLOPE FLOW WILL PERSIST THROUGH MUCH OF THE
NIGHT ACROSS SOUTHWEST KANSAS. WINDS ARE FORECAST TO VEER MORE
SOUTHERLY AFTER 10Z WHICH GIVEN LOSS IN UPSLOPE FLOW WHICH MAY
LIMIT HOW LOW VISIBILITIES WILL GET OVERNIGHT. EVEN WITH THIS IN
MIND THE LATEST HRRR STILL SUGGESTED A BRIEF PERIOD OF IFR
VSBY/CIGS BETWEEN 9Z AND 12Z AT HYS AND DDC. BASED ON A QUICK 5Z
VERIFICATION ON SURFACE INFORMATION THE HRRR MAY BE A LITTLE
AGGRESSIVE BUT WILL STILL INSERT A BRIEF PERIOD OF IFR VSBYS
BETWEEN 8Z AND 11Z. IF WINDS REMAIN SOUTHEAST THROUGH 12Z THEN
LIFR VSBYS WILL BE LIKELY TOWARDS DAYBREAK AT DDC AND HYS,
ESPECIALLY HYS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 69 36 71 41 / 0 0 0 0
GCK 71 33 71 37 / 0 0 0 0
EHA 72 39 72 40 / 0 0 0 0
LBL 72 31 73 36 / 0 0 0 0
HYS 66 31 71 38 / 0 0 0 0
P28 70 36 73 47 / 0 0 0 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR KSZ030-031-
045-046-064>066-079>081-089-090.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...BURGERT
LONG TERM...RUSSELL
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1201 AM CST SAT DEC 1 2012
...UPDATED TO INSERT DENSE FOG ADVISORY FOR SOUTH CENTRAL KANSAS...
.SYNOPSIS...
ISSUED AT 1109 PM CST FRI NOV 30 2012
AT 00Z SATURDAY AN UPPER LEVEL LOW WAS LOCATED OFF THE WEST COAST
OF BRITISH COLUMBIA. ONE UPPER LEVEL DISTURBANCE WAS LOCATED NEAR
THE BASED OF THE UPPER LOW, JUST OFF THE COAST OF THE PACIFIC
NORTHWEST. ANOTHER UPPER LEVEL TROUGH APPEARS TO EXTEND FROM
EXTREME NORTHWEST NEVADA INTO EAST CENTRAL CALIFORNIA. WEAK 500MB
RIDGING WAS PRESENT ACROSS THE ROCKIES. AT THE 700MB LEVEL A +4C
TO +8C RIDGE OF WARM AIR EXTENDED FROM WEST TEXAS NORTHWARD ALONG
THE LEE OF THE ROCKIES INTO EASTERN WYOMING/SOUTHWEST SOUTH
DAKOTA. AT THE 850MB LEVEL A WARM LEE TROUGH STRETCHED FROM
WESTERN NORTH DAKOTA INTO EASTERN ARIZONA. THE 850MB TEMPERATURE
AT AMARILLO AT 00Z SATURDAY WAS 18C, DODGE CITY AND RAPID CITY
HAD A 850MB TEMPERATURE OF +12. 850MB MOISTURE APPEARED TO BE
PRIMARILY CONFINED TO NORTH CENTRAL OKLAHOMA. AT THE SURFACE
EARLIER THIS EVENING A MOIST SOUTHEAST UPSLOPE FLOW HAD DEVELOPED
ACROSS WESTERN KANSAS. DEWPOINTS ACROSS NORTH CENTRAL OKLAHOMA
WERE IN THE LOWER 50S AND AS OF 04Z FOG HAD ALREADY DEVELOPED
ACROSS SOUTH CENTRAL AND PORTIONS OF WESTERN KANSAS.
&&
.UPDATE...
ISSUED AT 1156 PM CST FRI NOV 30 2012
AREAS OF FOG ACROSS SOUTH CENTRAL KASNAS WERE ALREADY REDUCING
VISIBILITIES TO LESS THAN ONE QUARTER MILE AS OF 11:45 PM. WITH A
MOIST UPSLOPE FLOW CONTINUING THROUGH THE PREDAWN HOURS THE DENSE
FOG IS EXPECTED TO BECOME MORE WIDESPREAD THROUGH DAYBREAK.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 245 PM CST FRI NOV 30 2012
THE UPPER LEVEL FLOW PATTERN OVER NORTH AMERICA CONTINUES TO BE
ZONAL WITH PERIODIC FAST MOVING SHORTWAVE TROUGHS EMBEDDED IN THE
FLOW OVER THE UNITED STATES. THIS MORNINGS ANALYSIS SHOWED ONE
SHORTWAVE MOVING OVER THE MISSISSIPPI VALLEY WHILE ANOTHER WAVE WAS
MOVING ONSHORE OVER THE WEST COAST. IN THE LOWER LEVELS, A LOW
PRESSURE TROUGH WAS LOCATED FROM EASTERN COLORADO INTO THE TEXAS
PANHANDLE. WEAK SOUTHERLY FLOW EAST OF THE TROUGH WAS BRINGING
40S/50S DEWPOINTS UP THROUGH OKLAHOMA INTO SOUTH CENTRAL AND
SOUTHEAST KANSAS.
THE MAIN FORECAST CONCERN TONIGHT WILL BE THE POTENTIAL FOR FOG
DEVELOPMENT OVER CENTRAL AND SOUTH CENTRAL PARTS OF KANSAS AND
POSSIBLY INTO PORTIONS OF SOUTHWEST KANSAS. THE 12Z NAM HAD A GOOD
HANDLE ON THE LOW LEVEL MOISTURE FIELDS ACROSS OKLAHOMA THIS MORNING
AND SHOWS THE 40 DEG ISODROSOTHERM MOVING UP TO AN ASHLAND-STAFFORD
LINE THIS EVENING. NAM BUFR SOUNDINGS SHOW THAT THE MOISTURE LAYER
WILL BE VERY SHALLOW, ONLY A FEW HUNDRED FEET THICK DEEP. THIS
SHOULD STILL BE DEEP ENOUGH FOR FOG DEVELOPMENT AND I HAVE ADDED
PATCHY FOG ALONG WITH AREAS OF FOG QUALIFIED WITH PATCHY DENSE TO
THE FORECAST FOR SOUTH CENTRAL KANSAS LATER TONIGHT. WIDESPREAD
DENSE FOG MAY BE KEPT IN CHECK BY SUFFICIENT MIXING IN THE BOUNDARY
LAYER ESPECIALLY ALONG HIGHWAY 281. MIXING LOOKS WEAKER FARTHER WEST
SO THERE COULD BE MORE POTENTIAL. THE NEXT APPROACHING SHORTWAVE
WILL BEGIN TO PUSH DRIER AIR EASTWARD INTO THE ASHLAND/DODGE CITY
/GREENSBURG AREAS EARLIER IN THE NIGHT WHICH WOULD DIMINISH THE
THREAT FOR DENSE FOG THERE. FOR NOW WILL HOLD OFF ON A FOG HEADLINE
AND LET THE NEXT SHIFT MAKE THAT DETERMINATION.
ANY FOG THAT DEVELOPS SHOULD BURN OFF A FEW HOURS AFTER SUNRISE ON
SATURDAY. AS THE SHORTWAVE TROUGH CONTINUES TO MOVE THROUGH, SURFACE
WINDS WILL BECOME NORTHWESTERLY AND INCREASE TO THE 10 TO 20 MPH
DURING THE MORNING HOURS BEFORE DIMINISHING IN THE AFTERNOON. HIGHS
SHOULD TOP OUT IN THE UPPER 60S TO LOWER 70S.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 245 PM CST FRI NOV 30 2012
BEYOND THE WEEKEND, THE LARGE SCALE SYNOPTIC PATTERN BECOMES
CONSIDERABLY MORE ACTIVE ACROSS THE WESTERN TWO THURSDAY OF THE
COUNTRY. THIS WILL NOT HOWEVER BRING A HIGH PROBABILITY OF
PRECIPITATION, HOWEVER, THE ODDS WILL INCREASE BY FRIDAY.
A ZONAL PATTERN WILL STILL BE FOUND ACROSS THE CENTRAL PLAINS
SATURDAY AND INTO SUNDAY, WITH THE POLAR JET DISPLACED FARTHER NORTH
ACROSS THE NORTHERN PLAINS. THIS PATTERN WILL AID IN MAINTAINING
LIGHT SOUTHERLY SURFACE WINDS, AS WELL AS WARMER THAN NORMAL HIGHS
IN THE 60`S, TO NEAR 70 DEGREES ON SUNDAY. A FAST MOVING STRONG
SHORTWAVE TROUGH ASSOCIATED WITH A STRONG EASTERN PACIFIC JET WILL
MOVE RAPIDLY EAST ACROSS THE COLORADO PLATEAU INTO THE HIGH PLAINS
REGION BY SUNDAY NIGHT. IMPRESSIVE SURFACE PRESSURE FALLS WILL TAKE
PLACE ACROSS THE CENTRAL AND NORTHERN HIGH PLAINS REGIONS SUNDAY
NIGHT, DEVELOPING LEE TROUGHING FROM NEW MEXICO INTO MONTANA. THE
MODELS THEN SHOVE A PACIFIC COLD FRONT ACROSS WESTERN KANSAS MONDAY
MORNING. THE COLD FRONT IS NOT EXPECTED TO BE PARTICULARLY STRONG,
BUT GFS AND IT`S MOS SUGGEST WIND SPEEDS BETWEEN 20 AND 25 KNOTS
DURING THE LATE MORNING AND AFTERNOON. WINDS SHOULD RAPIDLY
DECOUPLE, AND THE GRADIENT SHOULD SLACKEN CONSIDERABLY IN THE
EVENING TO ALLOW WINDS SPEED TO DECREASE TO AROUND 12 KNOTS OR LESS.
TEMPERATURES FOR MONDAY NIGHT WERE ADJUSTED TO COINCIDE CLOSER TO A
MOS CONSENSUS RATHER THAN THE WARM BIASED RAW MODELS. SURFACE HIGH
PRESSURE SHOULD HAVE AN IMPACT ON TUESDAY HIGHS. TEMPERATURES WILL
STRUGGLE THROUGH THE 50`S TUESDAY AFTERNOON AS COOL HIGH PRESSURE
CONTINUES TO PROMOTE LIGHT WINDS WITH NO SIGNIFICANT DOWNSLOPE
EFFECT. A REBOUND IN TEMPERATURES (ALBEIT SLIGHT) IS EXPECTED ONCE
AGAIN ON WEDNESDAY AS 500 MB HEIGHTS INCREASE AND THE BOUNDARY LAYER
SEES A RETURN TO SOUTHERLY WINDS. THE MODELS SUPPORT A BROAD TROUGH
MOVING ACROSS THE WESTERN UNITED STATES DURING THIS PERIOD. THE GFS
AND ECMWF HAVE DISTINCTLY DIFFERENT SOLUTIONS IN THE THERMODYNAMIC
FIELDS BY AROUND 180 HOURS. THE GFS ALLOWS THE SLUG OF VERY COLD
-20 TO -30 DEGREE C AIR AT 500 MB AIR TO SWING FARTHER SOUTH ACROSS
THE SOUTHERN CENTRAL HIGH PLAINS. THIS MORE AMPLIFIED PATTERN BETTER
SUPPORTS A DEEP UNSTABLE LAYER IN THIS TIME FRAME, AS WELL AS A
DEEPER DENDRITIC GROWTH POTENTIAL FOR SNOW ACROSS EASTERN COLORADO
AND WESTERN KANSAS AS EARLY AS FRIDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1109 PM CST FRI NOV 30 2012
A MOIST SOUTHEAST UPSLOPE FLOW WILL PERSIST THROUGH MUCH OF THE
NIGHT ACROSS SOUTHWEST KANSAS. WINDS ARE FORECAST TO VEER MORE
SOUTHERLY AFTER 10Z WHICH GIVEN LOSS IN UPSLOPE FLOW WHICH MAY
LIMIT HOW LOW VISIBILITIES WILL GET OVERNIGHT. EVEN WITH THIS IN
MIND THE LATEST HRRR STILL SUGGESTED A BRIEF PERIOD OF IFR
VSBY/CIGS BETWEEN 9Z AND 12Z AT HYS AND DDC. BASED ON A QUICK 5Z
VERIFICATION ON SURFACE INFORMATION THE HRRR MAY BE A LITTLE
AGGRESSIVE BUT WILL STILL INSERT A BRIEF PERIOD OF IFR VSBYS
BETWEEN 8Z AND 11Z. IF WINDS REMAIN SOUTHEAST THROUGH 12Z THEN
LIFR VSBYS WILL BE LIKELY TOWARDS DAYBREAK AT DDC AND HYS,
ESPECIALLY HYS.
&&
.FIRE WEATHER...
ISSUED AT 245 PM CST FRI NOV 30 2012
RELATIVELY WARM AND DRY CONDITIONS ARE FORECAST SATURDAY SUNDAY AND
MONDAY. RELATIVE HUMIDITY VALUES ARE EXPECTED TO FALL TO AROUND 20
PERCENT OR LOWER EACH AFTERNOON FOR A FEW HOURS. WINDS WILL BE LIGHT
SATURDAY AND SUNDAY, BUT INCREASE SUBSTANTIALLY ON MONDAY AS A COLD
FRONTAL BOUNDARY SWEEPS THROUGH WESTERN KANSAS. NORTH WINDS OF
AROUND 25 MPH WITH RELATIVE HUMIDITY FALLING TO AROUND 20 PERCENT
ARE EXPECTED MONDAY AFTERNOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 34 70 41 70 / 0 0 0 0
GCK 32 72 35 70 / 0 0 0 0
EHA 38 73 35 71 / 0 0 0 0
LBL 32 73 37 71 / 0 0 0 0
HYS 34 68 34 69 / 0 0 0 0
P28 42 72 40 72 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 9 AM CST SATURDAY FOR KSZ046-065-066-
079>081-089-090.
&&
$$
UPDATE...BURGERT
SYNOPSIS...BURGERT
SHORT TERM...GERARD
LONG TERM...RUSSELL
AVIATION...BURGERT
FIRE WEATHER...RUSSELL
AREA FORECAST DISCUSSION...CORRECTED
NWS DODGE CITY KS
1125 PM CST FRI NOV 30 2012
...UPDATED SYNOPSIS AND AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 1109 PM CST FRI NOV 30 2012
AT 00Z SATURDAY AN UPPER LEVEL LOW WAS LOCATED OFF THE WEST COAST
OF BRITISH COLUMBIA. ONE UPPER LEVEL DISTURBANCE WAS LOCATED NEAR
THE BASED OF THE UPPER LOW, JUST OFF THE COAST OF THE PACIFIC
NORTHWEST. ANOTHER UPPER LEVEL TROUGH APPEARS TO EXTEND FROM
EXTREME NORTHWEST NEVADA INTO EAST CENTRAL CALIFORNIA. WEAK 500MB
RIDGING WAS PRESENT ACROSS THE ROCKIES. AT THE 700MB LEVEL A +4C
TO +8C RIDGE OF WARM AIR EXTENDED FROM WEST TEXAS NORTHWARD ALONG
THE LEE OF THE ROCKIES INTO EASTERN WYOMING/SOUTHWEST SOUTH
DAKOTA. AT THE 850MB LEVEL A WARM LEE TROUGH STRETCHED FROM
WESTERN NORTH DAKOTA INTO EASTERN ARIZONA. THE 850MB TEMPERATURE
AT AMARILLO AT 00Z SATURDAY WAS 18C, DODGE CITY AND RAPID CITY
HAD A 850MB TEMPERATURE OF +12. 850MB MOISTURE APPEARED TO BE
PRIMARILY CONFINED TO NORTH CENTRAL OKLAHOMA. AT THE SURFACE
EARLIER THIS EVENING A MOIST SOUTHEAST UPSLOPE FLOW HAD DEVELOPED
ACROSS WESTERN KANSAS. DEWPOINTS ACROSS NORTH CENTRAL OKLAHOMA
WERE IN THE LOWER 50S AND AS OF 04Z FOG HAD ALREADY DEVELOPED
ACROSS SOUTH CENTRAL AND PORTIONS OF WESTERN KANSAS.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 245 PM CST FRI NOV 30 2012
THE UPPER LEVEL FLOW PATTERN OVER NORTH AMERICA CONTINUES TO BE
ZONAL WITH PERIODIC FAST MOVING SHORTWAVE TROUGHS EMBEDDED IN THE
FLOW OVER THE UNITED STATES. THIS MORNINGS ANALYSIS SHOWED ONE
SHORTWAVE MOVING OVER THE MISSISSIPPI VALLEY WHILE ANOTHER WAVE WAS
MOVING ONSHORE OVER THE WEST COAST. IN THE LOWER LEVELS, A LOW
PRESSURE TROUGH WAS LOCATED FROM EASTERN COLORADO INTO THE TEXAS
PANHANDLE. WEAK SOUTHERLY FLOW EAST OF THE TROUGH WAS BRINGING
40S/50S DEWPOINTS UP THROUGH OKLAHOMA INTO SOUTH CENTRAL AND
SOUTHEAST KANSAS.
THE MAIN FORECAST CONCERN TONIGHT WILL BE THE POTENTIAL FOR FOG
DEVELOPMENT OVER CENTRAL AND SOUTH CENTRAL PARTS OF KANSAS AND
POSSIBLY INTO PORTIONS OF SOUTHWEST KANSAS. THE 12Z NAM HAD A GOOD
HANDLE ON THE LOW LEVEL MOISTURE FIELDS ACROSS OKLAHOMA THIS MORNING
AND SHOWS THE 40 DEG ISODROSOTHERM MOVING UP TO AN ASHLAND-STAFFORD
LINE THIS EVENING. NAM BUFR SOUNDINGS SHOW THAT THE MOISTURE LAYER
WILL BE VERY SHALLOW, ONLY A FEW HUNDRED FEET THICK DEEP. THIS
SHOULD STILL BE DEEP ENOUGH FOR FOG DEVELOPMENT AND I HAVE ADDED
PATCHY FOG ALONG WITH AREAS OF FOG QUALIFIED WITH PATCHY DENSE TO
THE FORECAST FOR SOUTH CENTRAL KANSAS LATER TONIGHT. WIDESPREAD
DENSE FOG MAY BE KEPT IN CHECK BY SUFFICIENT MIXING IN THE BOUNDARY
LAYER ESPECIALLY ALONG HIGHWAY 281. MIXING LOOKS WEAKER FARTHER WEST
SO THERE COULD BE MORE POTENTIAL. THE NEXT APPROACHING SHORTWAVE
WILL BEGIN TO PUSH DRIER AIR EASTWARD INTO THE ASHLAND/DODGE CITY
/GREENSBURG AREAS EARLIER IN THE NIGHT WHICH WOULD DIMINISH THE
THREAT FOR DENSE FOG THERE. FOR NOW WILL HOLD OFF ON A FOG HEADLINE
AND LET THE NEXT SHIFT MAKE THAT DETERMINATION.
ANY FOG THAT DEVELOPS SHOULD BURN OFF A FEW HOURS AFTER SUNRISE ON
SATURDAY. AS THE SHORTWAVE TROUGH CONTINUES TO MOVE THROUGH, SURFACE
WINDS WILL BECOME NORTHWESTERLY AND INCREASE TO THE 10 TO 20 MPH
DURING THE MORNING HOURS BEFORE DIMINISHING IN THE AFTERNOON. HIGHS
SHOULD TOP OUT IN THE UPPER 60S TO LOWER 70S.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 245 PM CST FRI NOV 30 2012
BEYOND THE WEEKEND, THE LARGE SCALE SYNOPTIC PATTERN BECOMES
CONSIDERABLY MORE ACTIVE ACROSS THE WESTERN TWO THURSDAY OF THE
COUNTRY. THIS WILL NOT HOWEVER BRING A HIGH PROBABILITY OF
PRECIPITATION, HOWEVER, THE ODDS WILL INCREASE BY FRIDAY.
A ZONAL PATTERN WILL STILL BE FOUND ACROSS THE CENTRAL PLAINS
SATURDAY AND INTO SUNDAY, WITH THE POLAR JET DISPLACED FARTHER NORTH
ACROSS THE NORTHERN PLAINS. THIS PATTERN WILL AID IN MAINTAINING
LIGHT SOUTHERLY SURFACE WINDS, AS WELL AS WARMER THAN NORMAL HIGHS
IN THE 60`S, TO NEAR 70 DEGREES ON SUNDAY. A FAST MOVING STRONG
SHORTWAVE TROUGH ASSOCIATED WITH A STRONG EASTERN PACIFIC JET WILL
MOVE RAPIDLY EAST ACROSS THE COLORADO PLATEAU INTO THE HIGH PLAINS
REGION BY SUNDAY NIGHT. IMPRESSIVE SURFACE PRESSURE FALLS WILL TAKE
PLACE ACROSS THE CENTRAL AND NORTHERN HIGH PLAINS REGIONS SUNDAY
NIGHT, DEVELOPING LEE TROUGHING FROM NEW MEXICO INTO MONTANA. THE
MODELS THEN SHOVE A PACIFIC COLD FRONT ACROSS WESTERN KANSAS MONDAY
MORNING. THE COLD FRONT IS NOT EXPECTED TO BE PARTICULARLY STRONG,
BUT GFS AND IT`S MOS SUGGEST WIND SPEEDS BETWEEN 20 AND 25 KNOTS
DURING THE LATE MORNING AND AFTERNOON. WINDS SHOULD RAPIDLY
DECOUPLE, AND THE GRADIENT SHOULD SLACKEN CONSIDERABLY IN THE
EVENING TO ALLOW WINDS SPEED TO DECREASE TO AROUND 12 KNOTS OR LESS.
TEMPERATURES FOR MONDAY NIGHT WERE ADJUSTED TO COINCIDE CLOSER TO A
MOS CONSENSUS RATHER THAN THE WARM BIASED RAW MODELS. SURFACE HIGH
PRESSURE SHOULD HAVE AN IMPACT ON TUESDAY HIGHS. TEMPERATURES WILL
STRUGGLE THROUGH THE 50`S TUESDAY AFTERNOON AS COOL HIGH PRESSURE
CONTINUES TO PROMOTE LIGHT WINDS WITH NO SIGNIFICANT DOWNSLOPE
EFFECT. A REBOUND IN TEMPERATURES (ALBEIT SLIGHT) IS EXPECTED ONCE
AGAIN ON WEDNESDAY AS 500 MB HEIGHTS INCREASE AND THE BOUNDARY LAYER
SEES A RETURN TO SOUTHERLY WINDS. THE MODELS SUPPORT A BROAD TROUGH
MOVING ACROSS THE WESTERN UNITED STATES DURING THIS PERIOD. THE GFS
AND ECMWF HAVE DISTINCTLY DIFFERENT SOLUTIONS IN THE THERMODYNAMIC
FIELDS BY AROUND 180 HOURS. THE GFS ALLOWS THE SLUG OF VERY COLD
-20 TO -30 DEGREE C AIR AT 500 MB AIR TO SWING FARTHER SOUTH ACROSS
THE SOUTHERN CENTRAL HIGH PLAINS. THIS MORE AMPLIFIED PATTERN BETTER
SUPPORTS A DEEP UNSTABLE LAYER IN THIS TIME FRAME, AS WELL AS A
DEEPER DENDRITIC GROWTH POTENTIAL FOR SNOW ACROSS EASTERN COLORADO
AND WESTERN KANSAS AS EARLY AS FRIDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1109 PM CST FRI NOV 30 2012
A MOIST SOUTHEAST UPSLOPE FLOW WILL PERSIST THROUGH MUCH OF THE
NIGHT ACROSS SOUTHWEST KANSAS. WINDS ARE FORECAST TO VEER MORE
SOUTHERLY AFTER 10Z WHICH GIVEN LOSS IN UPSLOPE FLOW WHICH MAY
LIMIT HOW LOW VISIBILITIES WILL GET OVERNIGHT. EVEN WITH THIS IN
MIND THE LATEST HRRR STILL SUGGESTED A BRIEF PERIOD OF IFR
VSBY/CIGS BETWEEN 9Z AND 12Z AT HYS AND DDC. BASED ON A QUICK 5Z
VERIFICATION ON SURFACE INFORMATION THE HRRR MAY BE A LITTLE
AGGRESSIVE BUT WILL STILL INSERT A BRIEF PERIOD OF IFR VSBYS
BETWEEN 8Z AND 11Z. IF WINDS REMAIN SOUTHEAST THROUGH 12Z THEN
LIFR VSBYS WILL BE LIKELY TOWARDS DAYBREAK AT DDC AND HYS,
ESPECIALLY HYS.
&&
.FIRE WEATHER...
ISSUED AT 245 PM CST FRI NOV 30 2012
RELATIVELY WARM AND DRY CONDITIONS ARE FORECAST SATURDAY SUNDAY AND
MONDAY. RELATIVE HUMIDITY VALUES ARE EXPECTED TO FALL TO AROUND 20
PERCENT OR LOWER EACH AFTERNOON FOR A FEW HOURS. WINDS WILL BE LIGHT
SATURDAY AND SUNDAY, BUT INCREASE SUBSTANTIALLY ON MONDAY AS A COLD
FRONTAL BOUNDARY SWEEPS THROUGH WESTERN KANSAS. NORTH WINDS OF
AROUND 25 MPH WITH RELATIVE HUMIDITY FALLING TO AROUND 20 PERCENT
ARE EXPECTED MONDAY AFTERNOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 34 70 41 70 / 0 0 0 0
GCK 32 72 35 70 / 0 0 0 0
EHA 38 73 35 71 / 0 0 0 0
LBL 32 73 37 71 / 0 0 0 0
HYS 34 68 34 69 / 0 0 0 0
P28 42 72 40 72 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...GERARD
LONG TERM...RUSSELL
AVIATION...BURGERT
FIRE WEATHER...RUSSELL
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1122 PM CST FRI NOV 30 2012
...UPDATED SYNOPSIS AND AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 1109 PM CST FRI NOV 30 2012
AT 00Z SATURDAY AN UPPER LEVEL LOW WAS LOCATED OFF THE WEST COAST
OF BRITISH COLUMBIA. ONE UPPER LEVEL DISTURBANCE WAS LOCATED NEAR
THE BASED OF THE UPPER LOW, JUST OFF THE COAST OF THE PACIFIC
NORTHWEST. ANOTHER UPPER LEVEL TROUGH APPEARS TO EXTEND FROM
EXTREME NORTHWEST NEVADA INTO EAST CENTRAL CALIFORNIA. WEAK 500MB
RIDGING WAS PRESENT ACROSS THE ROCKIES. AT THE 700MB LEVEL A +4C
TO +8C RIDGE OF WARM AIR EXTENDED FROM WEST TEXAS NORTHWARD ALONG
THE LEE OF THE ROCKIES INTO EASTERN WYOMING/SOUTHWEST SOUTH
DAKOTA. AT THE 850MB LEVEL A WARM LEE TROUGH STRETCHED FROM
WESTERN NORTH DAKOTA INTO EASTERN ARIZONA. THE 850MB TEMPERATURE
AT AMARILLO AT 00Z SATURDAY WAS 18C, DODGE CITY AND RAPID CITY
HAD A 850MB TEMPERATURE OF +12. 850MB MOISTURE APPEARED TO BE
PRIMARILY CONFINED TO NORTH CENTRAL OKLAHOMA. AT THE SURFACE
EARLIER THIS EVENING A MOIST SOUTHEAST UPSLOPE FLOW HAD DEVELOPED
ACROSS WESTERN KANSAS. DEWPOINTS ACROSS NORTH CENTRAL OKLAHOMA
WERE IN THE LOWER 50S AND AS OF 04Z FOG HAD ALREADY DEVELOPED
ACROSS SOUTH CENTRAL AND PORTIONS OF WESTERN KANSAS.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 245 PM CST FRI NOV 30 2012
THE UPPER LEVEL FLOW PATTERN OVER NORTH AMERICA CONTINUES TO BE
ZONAL WITH PERIODIC FAST MOVING SHORTWAVE TROUGHS EMBEDDED IN THE
FLOW OVER THE UNITED STATES. THIS MORNINGS ANALYSIS SHOWED ONE
SHORTWAVE MOVING OVER THE MISSISSIPPI VALLEY WHILE ANOTHER WAVE WAS
MOVING ONSHORE OVER THE WEST COAST. IN THE LOWER LEVELS, A LOW
PRESSURE TROUGH WAS LOCATED FROM EASTERN COLORADO INTO THE TEXAS
PANHANDLE. WEAK SOUTHERLY FLOW EAST OF THE TROUGH WAS BRINGING
40S/50S DEWPOINTS UP THROUGH OKLAHOMA INTO SOUTH CENTRAL AND
SOUTHEAST KANSAS.
THE MAIN FORECAST CONCERN TONIGHT WILL BE THE POTENTIAL FOR FOG
DEVELOPMENT OVER CENTRAL AND SOUTH CENTRAL PARTS OF KANSAS AND
POSSIBLY INTO PORTIONS OF SOUTHWEST KANSAS. THE 12Z NAM HAD A GOOD
HANDLE ON THE LOW LEVEL MOISTURE FIELDS ACROSS OKLAHOMA THIS MORNING
AND SHOWS THE 40 DEG ISODROSOTHERM MOVING UP TO AN ASHLAND-STAFFORD
LINE THIS EVENING. NAM BUFR SOUNDINGS SHOW THAT THE MOISTURE LAYER
WILL BE VERY SHALLOW, ONLY A FEW HUNDRED FEET THICK DEEP. THIS
SHOULD STILL BE DEEP ENOUGH FOR FOG DEVELOPMENT AND I HAVE ADDED
PATCHY FOG ALONG WITH AREAS OF FOG QUALIFIED WITH PATCHY DENSE TO
THE FORECAST FOR SOUTH CENTRAL KANSAS LATER TONIGHT. WIDESPREAD
DENSE FOG MAY BE KEPT IN CHECK BY SUFFICIENT MIXING IN THE BOUNDARY
LAYER ESPECIALLY ALONG HIGHWAY 281. MIXING LOOKS WEAKER FARTHER WEST
SO THERE COULD BE MORE POTENTIAL. THE NEXT APPROACHING SHORTWAVE
WILL BEGIN TO PUSH DRIER AIR EASTWARD INTO THE ASHLAND/DODGE CITY
/GREENSBURG AREAS EARLIER IN THE NIGHT WHICH WOULD DIMINISH THE
THREAT FOR DENSE FOG THERE. FOR NOW WILL HOLD OFF ON A FOG HEADLINE
AND LET THE NEXT SHIFT MAKE THAT DETERMINATION.
ANY FOG THAT DEVELOPS SHOULD BURN OFF A FEW HOURS AFTER SUNRISE ON
SATURDAY. AS THE SHORTWAVE TROUGH CONTINUES TO MOVE THROUGH, SURFACE
WINDS WILL BECOME NORTHWESTERLY AND INCREASE TO THE 10 TO 20 MPH
DURING THE MORNING HOURS BEFORE DIMINISHING IN THE AFTERNOON. HIGHS
SHOULD TOP OUT IN THE UPPER 60S TO LOWER 70S.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 245 PM CST FRI NOV 30 2012
BEYOND THE WEEKEND, THE LARGE SCALE SYNOPTIC PATTERN BECOMES
CONSIDERABLY MORE ACTIVE ACROSS THE WESTERN TWO THURSDAY OF THE
COUNTRY. THIS WILL NOT HOWEVER BRING A HIGH PROBABILITY OF
PRECIPITATION, HOWEVER, THE ODDS WILL INCREASE BY FRIDAY.
A ZONAL PATTERN WILL STILL BE FOUND ACROSS THE CENTRAL PLAINS
SATURDAY AND INTO SUNDAY, WITH THE POLAR JET DISPLACED FARTHER NORTH
ACROSS THE NORTHERN PLAINS. THIS PATTERN WILL AID IN MAINTAINING
LIGHT SOUTHERLY SURFACE WINDS, AS WELL AS WARMER THAN NORMAL HIGHS
IN THE 60`S, TO NEAR 70 DEGREES ON SUNDAY. A FAST MOVING STRONG
SHORTWAVE TROUGH ASSOCIATED WITH A STRONG EASTERN PACIFIC JET WILL
MOVE RAPIDLY EAST ACROSS THE COLORADO PLATEAU INTO THE HIGH PLAINS
REGION BY SUNDAY NIGHT. IMPRESSIVE SURFACE PRESSURE FALLS WILL TAKE
PLACE ACROSS THE CENTRAL AND NORTHERN HIGH PLAINS REGIONS SUNDAY
NIGHT, DEVELOPING LEE TROUGHING FROM NEW MEXICO INTO MONTANA. THE
MODELS THEN SHOVE A PACIFIC COLD FRONT ACROSS WESTERN KANSAS MONDAY
MORNING. THE COLD FRONT IS NOT EXPECTED TO BE PARTICULARLY STRONG,
BUT GFS AND IT`S MOS SUGGEST WIND SPEEDS BETWEEN 20 AND 25 KNOTS
DURING THE LATE MORNING AND AFTERNOON. WINDS SHOULD RAPIDLY
DECOUPLE, AND THE GRADIENT SHOULD SLACKEN CONSIDERABLY IN THE
EVENING TO ALLOW WINDS SPEED TO DECREASE TO AROUND 12 KNOTS OR LESS.
TEMPERATURES FOR MONDAY NIGHT WERE ADJUSTED TO COINCIDE CLOSER TO A
MOS CONSENSUS RATHER THAN THE WARM BIASED RAW MODELS. SURFACE HIGH
PRESSURE SHOULD HAVE AN IMPACT ON TUESDAY HIGHS. TEMPERATURES WILL
STRUGGLE THROUGH THE 50`S TUESDAY AFTERNOON AS COOL HIGH PRESSURE
CONTINUES TO PROMOTE LIGHT WINDS WITH NO SIGNIFICANT DOWNSLOPE
EFFECT. A REBOUND IN TEMPERATURES (ALBEIT SLIGHT) IS EXPECTED ONCE
AGAIN ON WEDNESDAY AS 500 MB HEIGHTS INCREASE AND THE BOUNDARY LAYER
SEES A RETURN TO SOUTHERLY WINDS. THE MODELS SUPPORT A BROAD TROUGH
MOVING ACROSS THE WESTERN UNITED STATES DURING THIS PERIOD. THE GFS
AND ECMWF HAVE DISTINCTLY DIFFERENT SOLUTIONS IN THE THERMODYNAMIC
FIELDS BY AROUND 180 HOURS. THE GFS ALLOWS THE SLUG OF VERY COLD
-20 TO -30 DEGREE C AIR AT 500 MB AIR TO SWING FARTHER SOUTH ACROSS
THE SOUTHERN CENTRAL HIGH PLAINS. THIS MORE AMPLIFIED PATTERN BETTER
SUPPORTS A DEEP UNSTABLE LAYER IN THIS TIME FRAME, AS WELL AS A
DEEPER DENDRITIC GROWTH POTENTIAL FOR SNOW ACROSS EASTERN COLORADO
AND WESTERN KANSAS AS EARLY AS FRIDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1109 PM CST FRI NOV 30 2012
A MOIST SOUTHEAST UPSLOPE FLOW WILL PERSIST THROUGH MUCH OF THE
NIGHT AT DDC AND HYS. WINDS ARE FORECAST TO VEER MORE SOUTHERLY
AFTER 10Z WHICH GIVEN LOSS IN UPSLOPE FLOW MAY LIMIT HOW LOW
VISIBILITIES WILL GET OVER NIGHT AT DDC AND HYS. EVEN WITH THIS IN
MIND THE LATEST HRRR STILL SUGGESTED A BRIEF PERIOD OF IFR
VSBY/CIGS BETWEEN 9Z AND 12Z AT DDC AND HYS. BASED ON A QUICK 5Z
VERIFICATION ON SURFACE INFORMATION THE HRRR MAY BE A LITTLE
AGGRESSIVE, STILL IN INSERT A PERIOD OF MVFR VSBYS AT DDC AND HYS
BETWEEN 9Z AND 12Z. LOWEST VSBYS ARE EXPECTED TO BE IN THE HAYS
AREA MAY MAY LINGER THROUGH 15Z. IF WINDS REMAIN SOUTHEAST THROUGH
THE PREDAWN HOURS THEN IFR VSBYS WILL BE LIKELY TOWARDS DAYBREAK
AT DDC AND HYS, ESPECIALLY HYS.
&&
.FIRE WEATHER...
ISSUED AT 245 PM CST FRI NOV 30 2012
RELATIVELY WARM AND DRY CONDITIONS ARE FORECAST SATURDAY SUNDAY AND
MONDAY. RELATIVE HUMIDITY VALUES ARE EXPECTED TO FALL TO AROUND 20
PERCENT OR LOWER EACH AFTERNOON FOR A FEW HOURS. WINDS WILL BE LIGHT
SATURDAY AND SUNDAY, BUT INCREASE SUBSTANTIALLY ON MONDAY AS A COLD
FRONTAL BOUNDARY SWEEPS THROUGH WESTERN KANSAS. NORTH WINDS OF
AROUND 25 MPH WITH RELATIVE HUMIDITY FALLING TO AROUND 20 PERCENT
ARE EXPECTED MONDAY AFTERNOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 34 70 41 70 / 0 0 0 0
GCK 32 72 35 70 / 0 0 0 0
EHA 38 73 35 71 / 0 0 0 0
LBL 32 73 37 71 / 0 0 0 0
HYS 34 68 34 69 / 0 0 0 0
P28 42 72 40 72 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...GERARD
LONG TERM...RUSSELL
AVIATION...BURGERT
FIRE WEATHER...RUSSELL
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1057 AM CST SAT DEC 1 2012
.UPDATE...
ISSUED AT 1057 AM CST SAT DEC 1 2012
,MESOSCALE UPDATE...MINOR ADJUSTMENT TO SHORT TERM GRIDS FOR LATE
THIS MORNING AND INTO THIS AFTERNOON. KPAH WSR-88D HAS BEEN
INDICATING SOME 15-25 DBZ LINEAR ORIENTED RADAR RETURNS BETWEEN
2.5-5KFT MSL SINCE ABOUT 14Z..JUST EAST OF THE MISSISSIPPI
RIVER...JUST SOUTH OF CAIRO IL. THE VISIBLE SATELLITE IMAGERY WAS
ALSO SHOWING SOME CONVECTIVE ELEMENTS IN A SOUTHWEST TO NORTHEAST
ORIENTED BAND FROM THE CONFLUENCE OF THE OH/MS RIVER TO THE
CONFLUENCE OF THE WABASH/OHIO RIVER. THESE ELEMENTS WERE EMBEDDED
IN A BROADER...ISENTROPICALLY LIFTED CLOUD SHIELD COVERING MOST OF
THE WFO PAH FORECAST AREA...WITH THE EXCEPTION OF PARTS OF THE
PENNYRILE REGION OF WEST KENTUCKY...AS WELL AS SWRN IL/FOOTHILLS
OF SOUTHEAST MO.
GIVEN THE LIMITED LIFT AND INSTABILITY...DO NOT EXPECT MUCH MORE
THAN SPRINKLES /TRACE PRECIPITATION POTENTIAL/ ORIENTED IN THE
AFOREMENTIONED CONVECTIVE BAND SHIFTS NORTHEASTWARD INTO SOUTHWEST
INDIANA THIS AFTERNOON. GIVEN THE SMALL AREA IN BOTH TIME AND
SPACE...THIS PRECIPITATION WILL NOT LIKELY SHOW UP IN THE BROADER
WORDED TEXT PRODUCTS OR PERIODIC TABULAR PRODUCTS...BUT SHOULD BE
NOTICEABLE IN THE GRIDDED FORECAST PRODUCTS THAT WILL BE
EFFECTIVELY DEPICTED IN THE WEB-BASED POINT AND CLICK PRODUCTS.
LEANED CLOSER TO THE 3KM HRRR AND 12KM NAM-WRF GUIDANCE FOR THE
REFLECTIVITY/PRECIPITATION/POP POTENTIAL FOR THE REST OF TODAY.
GIVEN THE GREATER MOISTURE PLUME IN THE WESTERN 1/3 OF THE WFO PAH
FORECAST AREA THIS MORNING /0.80+ INCHES PER THE GOES PRECIPITABLE
WATER SOUNDER DATA/...LEANED TOWARD THE RUC/RAP/NAM SOLUTION WITH
RESPECT THE INFLUX OF WARM/MOIST ADVECTION INTO THE WFO PAH CWA.
WITH THAT IN MIND...ADJUSTED MAX TEMPERATURES UP SLIGHTLY /
FORECAST TEMPERATURES THE LAST COUPLE OF HOURS WERE RUNNING 1-3
DEGREES SLIGHTLY COOLER DEPENDING ON LOCATION/.
OTHER ADJUSTMENTS WERE MADE TO SHORT TERM DEWPOINTS...SKY COVER
AND WINDS THROUGH THE EVENING AND OVERNIGHT HOURS...AS THE
AGEOSTROPHIC RESPONSE TO THE APPROACHING COLD FRONT COMES INTO
PLAY WITH TIME.
MAY NEED TO TAKE A CLOSER LOOK AT INSTABILITY TONIGHT...WFO IND
AND SPC HINT THAT MIXED LAYER CAPE MAY BE A LITTLE GREATER THAN
FORECAST AT THIS TIME...WILL TAKE A LOOK.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 337 AM CST SAT DEC 1 2012
MODELS IN FAIRLY GOOD AGREEMENT THROUGH THE SHORT TERM. SLIGHT
DIFFERENCES IN THE TIMING OF PRECIP CHANCES. HAVE HELD OFF
INTRODUCING CHANCES OF SHOWERS ACROSS THE OZARKS INTO SW ILLINOIS
UNTIL AFTER SUNSET TODAY. NAM SHOWS A COUPLE OF VERY DISTINCT
IMPULSES THAT WILL BRING THE THREAT...ALBEIT SMALL...OF RAINFALL TO
THE REGION. MAIN THREATS APPEAR TO BE SATURDAY NIGHT INTO SUNDAY
MORNING LINGERING INTO MONDAY MAINLY IN THE EASTERN SECTIONS. ALL OF
THIS IS IN ADVANCE OF A LARGER STORM SYSTEM APPROACHING.
SOUTH WINDS HAVE ALREADY KICKED TEMPS AND DEWPOINTS UP. GOING TO
STRUGGLE TO DROP TO THE FORECAST LOWS THIS MORNING. EXPECT STEADILY
INCREASING HIGH TEMPS THROUGH MONDAY. MONDAY SHOULD SEE 70 DEGREES
IN MOST LOCATIONS. LOWS THE NEXT COUPLE OF NIGHTS WILL STAY IN THE
50S.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 337 AM CST SAT DEC 1 2012
THE EXTENDED PORTION OF THE FORECAST WILL BE DOMINATED BY A FAST
WEST TO EAST ZONAL FLOW PATTERN ACROSS MUCH OF THE CONUS. THE
PASSAGE OF A COUPLE OF FRONTAL SYSTEMS WILL PROVIDE THE POTENTIAL
FOR LIQUID PRECIPITATION. THE FIRST SYSTEM IS SLATED FOR MONDAY
NIGHT AND TUESDAY...WITH THE SECOND LATE IN THE WEEK.
FORECAST CONFIDENCE WITH THE FIRST SYSTEM IS RELATIVELY HIGH AS
MODELS REMAIN IN GOOD AGREEMENT ON THE TIMING AND PLACEMENT OF
SURFACE AND UPPER LEVEL FEATURES. A STRONG COLD FRONT WILL BE
SITUATED ALONG THE WESTERN PERIPHERY OF THE FORECAST AREA AT
DAYBREAK TUESDAY. THE FRONT WILL PROGRESS EAST ACROSS THE REGION
THROUGH THE COURSE OF THE DAY. STRONG FORCING FOR ASCENT AND
RELATIVELY HIGH ATMOSPHERIC MOISTURE WILL RESULT IN A WIDESPREAD
RAIN EVENT. MARGINAL ELEVATED INSTABILITY MAY ALSO YIELD A FEW
RUMBLES OF THUNDER AS WELL. BEST CHANCES FOR RAIN SHOWERS WILL
ENTER WESTERN PORTIONS OF SOUTHEAST MISSOURI AND SOUTHERN ILLINOIS
LATE MONDAY NIGHT...AND SPREAD ACROSS THE REMAINDER OF THE REGION
ON TUESDAY. CLOUDS AND MIXING WILL KEEP TEMPERATURES UNSEASONABLY
WARM MONDAY NIGHT. TEMPERATURES TUESDAY WILL NOT RISE MUCH...AND
MAY ACTUALLY FALL INTO THE AFTERNOON IN THE WAKE OF THE FRONT.
ANY LINGERING SHOWERS WILL COME TO AN END TUESDAY EVENING ACROSS
WESTERN KENTUCKY. THE CORE OF HIGH PRESSURE WILL SLIDE ACROSS
THE GREAT LAKES REGION ON WEDNESDAY...AND INTO THE NORTHEAST ON
THURSDAY. THIS WILL RESULT IN A PERIOD OF DRY AND SEASONABLY COOL
WEATHER BOTH DAYS. MORNINGS WILL START OFF COLD...BUT MILD WEATHER
WILL TAKE HOLD BY AFTERNOON.
AS OPPOSED TO THE FIRST SYSTEM...FORECAST CONFIDENCE WITH THE LATE
WEEK SYSTEM IS SOMEWHAT LOWER. WHILE BOTH THE GFS AND ECMWF AGREE
ON AN INCREASED CHANCE FOR RAIN LATE IN THE WEEK...THE GFS
CONTINUES TO SIGNAL FRONTAL PASSAGE ABOUT 12 TO 18 HOURS SOONER
THAN THE ECMWF...ADMITTEDLY NOT TOO SHABBY...CONSIDERING THIS IS
DAY 7. FOR NOW...WILL USE A BLEND OF BOTH MODELS UNTIL SUCH TIME A
FRONTRUNNER EMERGES. LATE WEEK TEMPERATURES WILL WARM TO WELL
ABOVE NORMAL AHEAD OF THE APPROACHING FRONT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1057 AM CST SAT DEC 1 2012
LIFT BECOMES A LITTLE GREATER FROM WEST TO EAST FROM SUNSET
ONWARD. LOOK FOR CEILINGS TO TRANSITION FROM VFR TO MVFR BETWEEN
06Z TO 09Z SUNDAY AT KCGI WITH THE THE POTENTIAL FOR 3SM TO 5SM
SHOWERS AND IFR CEILINGS /THUNDER POTENTIAL STILL BE ASSESSED AT
THIS TIME/ BETWEEN THE 09Z-15Z TIME AT KCGI. THIS SIMILAR CEILING
AND VISIBILITY SCENARIO WILL LIKELY BE OFFSET AT LEAST TWO HOURS
FORWARD IN TIME AT KPAH...KEVV...KOWB PERSISTING FOR THE REMAINDER
OF THE FORECAST PERIOD AT THESE SITE.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...SMITH
SHORT TERM...ML
LONG TERM....RJP
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
323 PM EST SAT DEC 1 2012
.SYNOPSIS...
LOW PRESSURE MOVING EASTWARD THROUGH THE GREAT LAKES SUNDAY WILL
BRING SHOWERS TO THE UPPER OHIO VALLEY SUNDAY AFTERNOON AND NIGHT.
CONDITIONS WILL REMAIN SEASONABLY WARM UNTIL A STRONG COLD FRONT
MOVES THROUGH TUESDAY NIGHT.
&&
.NEAR TERM /THROUGH SUNDAY NIGHT/...
BASED ON RECENT SURFACE AND SATELLITE DATA EXPECT NO MORE THAN
PARTLY CLOUDY SKIES EARLY TONIGHT. RECENT SREF MODEL OUTPUT WITH
DETAILS FROM RECENT NAM AND GFS...SHOW CLOUDS INCREASING LATE
TONIGHT AND SUNDAY ACROSS THE UPPER OHIO VALLEY.
BANDS OF SHOWERS...ASSOCIATED WITH EASTBOUND LOW PRESSURE THROUGH
THE GREAT LAKES...WILL MOVE EASTWARD THROUGH THE UPPER OHIO VALLEY
MAINLY SUNDAY AFTERNOON AND EVENING.
BASED ON BLEND OF RECENT RAP MODEL OUTPUT...AND NAM AND GFS
MOS...FORECASTED TEMPERATURES TO BE MUCH AS 15 DEGREES WARMER
THAN NORMAL TONIGHT AND UP TO 20 DEGREES WARMER THAN NORMAL
SUNDAY. PRE-SHOWER VERTICAL MIXING MAY PROMOTE WINDS TO GUST TO 30
MPH.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
BLEND OF SREF AND ECMWF MODEL OUTPUT SHOW HIGH PRESSURE WILL
FOLLOW TO PROVIDE A DRY BREAK MONDAY INTO EARLY TUESDAY.
A STRONG EASTBOUND COLD FRONT WILL BRING BANDS OF SHOWERS MAINLY
TUESDAY AFTERNOON AND EVENING.
BASED ON RECENT NAM GFS AND ECMWF MOS...FORECASTED TEMPERATURES TO
AS MUCH AS 20 DEGREES WARMER THAN NORMAL MONDAY AND TUESDAY.
POSTFRONTAL LOWS TUESDAY NIGHT WILL BE NO MORE THAN 5 DEGREES
ABOVE NORMAL.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
MODELS WERE IN GENERAL AGREEMENT ON THE OVERALL PATTERN THROUGH THE
LONG TERM PERIOD.
CAA IN NW FLOW ACROSS LAKE ERIE...COMBINED WITH AN UPPER LEVEL
TROUGH MOVING ACROSS THE EASTERN GREAT LAKES...COULD BRING A FEW
SNOW SHOWERS MAINLY TO AREAS NORTH OF PITTSBURGH WEDNESDAY. HIGH
PRESSURE BUILDING IN BY LATE WEDNESDAY INTO THURSDAY SHOULD BRING AN
END TO ANY SNOW SHOWER ACTIVITY.
ANOTHER COLD FRONT IS EXPECTED TO MOVE SLOWLY EAST ACROSS THE AREA
FRIDAY INTO FRIDAY NIGHT...BRINGING ANOTHER CHANCE OF RAIN SHOWERS.
TEMPERATURES SHOULD AVERAGE NEAR OR A LITTLE ABOVE NORMAL THROUGH
THE PERIOD.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
VFR CONDITIONS WITH PATCHY STRATOCU AND HIGH CLOUDS ARE EXPECTED
THROUGH TONIGHT. LOW LEVEL WINDS INCREASE OVERNIGHT INTO SUNDAY
MORNING...WITH THE BEST CHANCE OF SEEING LLWS ACROSS FKL AND DUJ
IN THE NORTH. LLWS CHANCES APPEAR MORE MARGINAL FOR OTHER SITES
AND KEPT OUT OF THE TAFS FOR NOW. EXPECT SFC WND GUSTS OF AROUND
20KT FROM THE SW AS MIXING BEGINS AFTER SUNRISE SUNDAY MORNING.
MVFR FLIGHT CONDITIONS ARE POSSIBLE SUNDAY AFTERNOON AND NIGHT WITH
BANDS OF SHOWERS ASSOCIATED WITH LOW PRESSURE MOVING EASTWARD
THROUGH THE GREAT LAKES.
.OUTLOOK.../MONDAY THROUGH THURSDAY/...
VFR WILL BE PREVALENT MONDAY INTO MIDDAY TUESDAY DUE TO PASSING
HIGH PRESSURE. RESTRICTIONS WILL BE POSSIBLE LATE TUESDAY INTO
WEDNESDAY DUE TO A STRONG COLD FRONT AND ENSUING LAKE-EFFECT AND
COLD POOL CLOUDS AND SCATTERED SNOW SHOWERS NORTH.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1226 PM EST SAT DEC 1 2012
.SYNOPSIS...
DRY WEATHER WILL CONTINUE INTO EARLY SUNDAY. A WEAK COLD FRONT
WILL BRING SHOWERS SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
RECENT SURFACE AND SATELLITE DATA SHOW SCATTERED CUMULUS AND BANDS
OF NUMEROUS CIRRUS CLOUDS WILL CONTINUE TO MOVE SOUTHEASTWARD
ACROSS THE UPPER OHIO VALLEY THIS AFTERNOON. CLOUDS APPEAR RATHER
THIN...SO EXPECT PARTLY TO MOSTLY SUNNY CONDITIONS THIS AFTERNOON.
SOUTHWEST SURFACE WINDS...IN THE WAKE OF OFFSHORE HIGH PRESSURE...CONTINUE
TO BRING WARMER AIR...SO HAVE RAISED TEMPERATURES THIS AFTERNOON
BY A COUPLE DEGREES WITH HIGHS AS MUCH AS 15 DEGREES WARMER THAN
NORMAL PER RECENT RAP MODEL OUTPUT AND GFS LAMP.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
UPPER LEVEL FLOW BECOMES ZONAL TONIGHT...AHEAD OF A SHORTWAVE
TROUGH THAT WILL MOVE THROUGH THE UPPER MIDWEST. THIS WAVE WILL
BRING AN INCREASE IN CLOUD COVER LATE TONIGHT. FOLLOWING ON THE
HEELS OF THE SHORTWAVE IS A WEAK COLD FRONT WHICH WILL SLOWLY MOVE
THROUGH THE GREAT LAKES SUNDAY AFTERNOON.
WITH VERY LITTLE UPPER LEVEL SUPPORT ACCOMPANYING THE
BOUNDARY...IT WILL HAVE A DIFFICULT TIME MAKING MUCH SOUTHWARD
PROGRESS. BY LATE SUNDAY AFTERNOON...IT BECOMES DIFFICULT TO FIND
THE SFC BOUNDARY AS IT LOSES MUCH OF IT DEFINITION.
MODELS CONTINUE TO SHOW AN AREA OF SHOWERS MOVING THROUGH
SUNDAY...BUT THIS APPEARS TO BE MORE RELATED TO ANOTHER WEAK
SHORTWAVE SWINGING THROUGH LATE SUNDAY. WOULD THINK THE AREA MOST
LIKELY TO SEE RAIN SUNDAY WOULD BE ACROSS THE NORTH...DUE TO THE
POSITIONING OF THE VORT MAX. THERE WILL BE PLENTY OF CLOUD ON
SUNDAY...BUT MOST OF THE SHOWERS WOULD BE SCATTERED.
THERE WILL BE LITTLE IF ANY CHANGE IN AIR MASS...SO THE MILD
WEATHER WILL CONTINUE INTO MONDAY.
UPPER LEVEL RIDGE BUILDS BACK IN ON MONDAY...MEANING ANOTHER DRY
AND MILD DAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
MODELS WERE IN GENERAL AGREEMENT ON THE OVERALL PATTERN DURING THE
LONG TERM PERIOD...BUT VARY ON TIMING. PREFERRED THE NAEFS SOLUTION
WHICH WAS SLOWER THAN THE GFS BUT SLIGHTLY FASTER THAN THE ECMWF.
A COLD FRONT WILL MOVE ACROSS THE REGION LATE TUESDAY INTO TUESDAY
NIGHT BRINGING A FEW SHOWERS. COLDER AIR MOVING IN BEHIND THE FRONT
ON WEDNESDAY...COMBINED WITH AN UPPER LEVEL TROF MOVING ACROSS THE
GREAT LAKES...COULD BRING A FEW SNOW SHOWERS TO THE FAR NORTHERN
COUNTIES DURING THE DAY...HOWEVER HIGH PRESSURE SHOULD QUICKLY BUILD
IN ENDING ANY PRECIP.
EXPECT TEMPS WEDNESDAY TO SLOWLY FALL OFF DURING THE LATE MORNING
AND AFTERNOON AS WELL WITH THE CAA. TEMPS SHOULD INCREASE TO ABOVE
NORMAL LEVELS AGAIN BY LATE IN THE WEEK.
ANOTHER COLD FRONT APPROACHES FROM THE WEST FRIDAY AFTERNOON.
&&
.AVIATION /17Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDITIONS WITH PATCHY STRATOCU AND HIGH CLOUDS ARE EXPECTED
THROUGH TONIGHT. LOW LEVEL WINDS INCREASE OVERNIGHT INTO SUNDAY
MORNING...WITH THE BEST CHANCE OF SEEING LLWS ACROSS FKL AND DUJ
IN THE NORTH. LLWS CHANCES APPEAR MORE MARGINAL FOR OTHER SITES
AND KEPT OUT OF THE TAFS FOR NOW. EXPECT SFC WND GUSTS OF AROUND
20KT FROM THE SW AS MIXING BEGINS AFTER SUNRISE SUNDAY MORNING.
.OUTLOOK.../SUNDAY THROUGH WEDNESDAY/...
MVFR CONDITIONS ARE POSSIBLE SUNDAY AFTERNOON AND EVENING AS A
WEAK DISTURBANCE MOVES ACROSS THE AREA. RESTRICTIONS ARE POSSIBLE
AGAIN LATE TUESDAY INTO WEDNESDAY AS A COLD FRONT MOVES ACROSS THE
AREA.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1153 AM EST SAT DEC 1 2012
.SYNOPSIS...
DRY WEATHER WILL CONTINUE INTO EARLY SUNDAY. A WEAK COLD FRONT
WILL BRING SHOWERS SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
RECENT SURFACE AND SATELLITE DATA SHOW SCATTERED CUMULUS AND BANDS
OF NUMEROUS CIRRUS CLOUDS WILL CONTINUE TO MOVE SOUTHEASTWARD
ACROSS THE UPPER OHIO VALLEY THIS AFTERNOON. CLOUDS APPEAR RATHER
THIN...SO EXPECT PARTLY TO MOSTLY SUNNY CONDITIONS THIS AFTERNOON.
SOUTHWEST SURFACE WINDS...IN THE WAKE OF OFFSHORE HIGH PRESSURE...CONTINUE
TO BRING WARMER AIR...SO HAVE RAISED TEMPERATURES THIS AFTERNOON
BY A COUPLE DEGREES WITH HIGHS AS MUCH AS 15 DEGREES WARMER THAN
NORMAL PER RECENT RAP MODEL OUTPUT AND GFS LAMP.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
UPPER LEVEL FLOW BECOMES ZONAL TONIGHT...AHEAD OF A SHORTWAVE
TROUGH THAT WILL MOVE THROUGH THE UPPER MIDWEST. THIS WAVE WILL
BRING AN INCREASE IN CLOUD COVER LATE TONIGHT. FOLLOWING ON THE
HEELS OF THE SHORTWAVE IS A WEAK COLD FRONT WHICH WILL SLOWLY MOVE
THROUGH THE GREAT LAKES SUNDAY AFTERNOON.
WITH VERY LITTLE UPPER LEVEL SUPPORT ACCOMPANYING THE
BOUNDARY...IT WILL HAVE A DIFFICULT TIME MAKING MUCH SOUTHWARD
PROGRESS. BY LATE SUNDAY AFTERNOON...IT BECOMES DIFFICULT TO FIND
THE SFC BOUNDARY AS IT LOSES MUCH OF IT DEFINITION.
MODELS CONTINUE TO SHOW AN AREA OF SHOWERS MOVING THROUGH
SUNDAY...BUT THIS APPEARS TO BE MORE RELATED TO ANOTHER WEAK
SHORTWAVE SWINGING THROUGH LATE SUNDAY. WOULD THINK THE AREA MOST
LIKELY TO SEE RAIN SUNDAY WOULD BE ACROSS THE NORTH...DUE TO THE
POSITIONING OF THE VORT MAX. THERE WILL BE PLENTY OF CLOUD ON
SUNDAY...BUT MOST OF THE SHOWERS WOULD BE SCATTERED.
THERE WILL BE LITTLE IF ANY CHANGE IN AIR MASS...SO THE MILD
WEATHER WILL CONTINUE INTO MONDAY.
UPPER LEVEL RIDGE BUILDS BACK IN ON MONDAY...MEANING ANOTHER DRY
AND MILD DAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MODELS WERE IN GENERAL AGREEMENT ON THE OVERALL PATTERN DURING THE
LONG TERM PERIOD...BUT VARY ON TIMING. PREFERRED THE NAEFS SOLUTION
WHICH WAS SLOWER THAN THE GFS BUT SLIGHTLY FASTER THAN THE ECMWF.
A COLD FRONT WILL MOVE ACROSS THE REGION LATE TUESDAY INTO TUESDAY
NIGHT BRINGING A FEW SHOWERS. COLDER AIR MOVING IN BEHIND THE FRONT
ON WEDNESDAY...COMBINED WITH AN UPPER LEVEL TROF MOVING ACROSS THE
GREAT LAKES...COULD BRING A FEW SNOW SHOWERS TO THE FAR NORTHERN
COUNTIES DURING THE DAY...HOWEVER HIGH PRESSURE SHOULD QUICKLY BUILD
IN ENDING ANY PRECIP.
EXPECT TEMPS WEDNESDAY TO SLOWLY FALL OFF DURING THE LATE MORNING
AND AFTERNOON AS WELL WITH THE CAA. TEMPS SHOULD INCREASE TO ABOVE
NORMAL LEVELS AGAIN BY LATE IN THE WEEK.
ANOTHER COLD FRONT APPROACHES FROM THE WEST FRIDAY AFTERNOON.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AN AREA OF MID AND HIGH CLOUDS IN ASSOCIATION WITH A PASSING MID-
LEVEL SYSTEM WILL MOVE THROUGH THE AREA. OTHERWISE...RAGGED HIGH
CLOUDS WILL BE COMMON ACROSS THE REGION...AND WINDS GIVE A WEAK
SURFACE PATTERN WILL BE RATHER LIGHT. AS SUCH...GENERALLY VFR
CONDITIONS SHOULD PREVAIL AT ALL SITES THROUGH SATURDAY.
.OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/...
RESTRICTIONS WILL BE POSSIBLE SUNDAY AFTERNOON AND NIGHT...DUE TO
SHOWER FORMATION ALONG A WEAK EASTBOUND FRONT. A BETTER RESTRICTION
CHANCE WILL ACCOMPANY A STRONG COLD FRONT PASSAGE ON TUESDAY NIGHT...AND
WILL LIKELY PERSIST WITH COLD POOL CLOUDS AND SCATTERED SNOW SHOWERS
WEDNESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
1041 AM EST SAT DEC 1 2012
.SYNOPSIS...
HIGH PRESSURE RIDGING SOUTHWARD TOWARD THE MID-ATLANTIC REGION
TODAY WILL SHIFT OFF THE COAST TONIGHT WHILE A STALLED FRONT
DRAPED SOUTH OF THE AREA RETREATS NORTHEASTWARD AS A WARM FRONT
TONIGHT INTO SUNDAY. A WEAK COLD FRONT WILL MOVE EAST THROUGH THE
REGION SUNDAY NIGHT. A SLIGHTLY STRONGER COLD FRONT WILL MOVE
THROUGH THE MID ATLANTIC LATE TUESDAY AND EARLY WEDNESDAY FOLLOWED
BY HIGH PRESSURE BUILDING IN FOR THE REMAINDER OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
LATEST SFC ANALYSIS SHOWS A 1041 MB HIGH CENTERED OVER NRN NEW
ENGLAND. HIPRES HAS RIDGED SWD TOWARD THE MID-ATLANTIC REGION...
PRODUCING A CAD SETUP. A VERY DIFFUSE FRONTAL BOUNDARY LIES NEARLY
STATIONARY SOUTH AND WEST OF THE CWA. 12Z IAD RAOB SHOWS THIS
WEDGE OF COLD AIR NEAR THE SFC IS TRAPPED WITHIN A SIGNIFICANT
INVERSION LAYER IN THE LOWEST 3 KFT. SHALLOW E-NE FLOW NEAR THE
SFC HAS ADVECTED LOW STRATUS AND FOG INLAND TOWARD NORTH- CENTRAL
AND SRN MD...AND NRN VA. FCST FOR EROSION OF MRNG STRATUS IS MORE
PESSIMISTIC THAN ALL MODEL GUIDANCE AS THE LOW DEC SUN ANGLE WILL
LIMIT ABILITY OF DAYTIME MIXING TO ERODE THE INVERSION. EXPECT TO
SEE SOME IMPROVEMENT MIDDAY ALONG THE PERIPHERY OF THE STRATUS
DECK...BUT OVER NERN MD...WHERE CAD IS SOCKED IN...CLEARING MAY
NOT OCCUR UNTIL MID AFTN.
HIPRES BEGINS TO SHIFT OFF MAINE COAST LATE THIS AFTN. WITH
DEVELOPING SLY RETURN FLOW...THE AFOREMENTIONED FRONTAL BOUNDARY
WILL ATTEMPT TO LIFT BACK NWD AS A WARM FRONT. NOT SURE HOW MUCH
NWD PROGRESSION IT WILL MAKE...ESPECIALLY EAST OF THE BLUE
RIDGE...WITH SHALLOW WEDGE OF COLD AIR STUBBORN TO ERODE. CLOUD
COVER AND CAD WILL YIELD A HIGHER THAN NORMAL N-S TEMPERATURE
GRADIENT. MAX TEMPS WILL RANGE FROM THE UPPER 40S ACROSS THE NRN
SUBURBS OF BALTIMORE TO NEAR 60F SOUTH OF CHO.
RDGG WL TAKE HOLD AT THE SFC AND ALOFT TNGT. NRN CNTYS WL BE
NEARER TO FASTER MID-LVL FLOW...SO WL PAINT SCT TO ALMOST BKN CLDS
THERE. LOW STRATUS AND FOG MAY REDEVELOP AGAIN TNGT. DEWPTS SHUD
BE HIER /A RSLT OF RESIDUAL MSTR FM THE PRESENT ENE FLOW/...SO HV
FCST MIN-T LIKEWISE.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
SOME DEJA VU MOMENTS OVER THE COMING WEEK...AS A COUPLE OF FRONTAL
PASSAGES SHAPING UP FOR THE REGION - BRIDGED BY SIMILAR BOUTS OF
HIGH PRESSURE. THE FIRST FRONT WILL LARGELY WASH OUT AS IT CROSSES
THE AREA OVERNIGHT SUN INTO EARLY MON. THE PARENT LOW WILL SPEED OFF
TO THE NE FROM THE GREAT LAKES REGION ON SUN...LEAVING THE FRONT TO
DISSIPATE AS IT CROSSES THE APLCNS SUN NIGHT. UNLIKE MOST FRONTAL
PASSAGES...ESPECIALLY THIS TIME OF YEAR...IT WON`T EXACTLY BE MARKED
BY A SIGNIFICANT TEMP CHANGE. IN FACT...SUN NIGHT WILL BE ONE OF THE
WARMER NIGHTS IN RECENT MEMORY - ONLY DROPPING INTO THE U40S FOR
OVERNIGHT LOWS. A FEW LIGHT SHOWERS MAY REAPPEAR ALONG THE I-95
CORRIDOR BEFORE THE FRONT MOVES OFF THE COAST...BUT VERY LIGHT AND
SHORT LIVED.
THE WARM OVERNIGHT PERIOD SUN NIGHT WILL OCCUR IN LARGE PART BECAUSE
THE DAYTIME HRS ON SUN WILL HAVE HAD A GOOD SLY BREEZE IN
PLACE...INCREASING THE LOW LEVEL MOISTURE. DESPITE THE WIND SHIFT W/
THE FRONT EARLY MON TOWARD THE NW...DRIER AIR WILL NOT MIX INTO THE
AREA - HELPING TO KEEP TEMPS MODERATED OVERNIGHT. SAME STORY ON
MON...AS THE SFC HIGH REESTABLISHES ITSELF OVER THE EAST COAST AND
SENDS ANOTHER SEVERAL HRS OF WARM/MOIST SLY WINDS UP THE ERN
SEABOARD. TEMPS WILL MAKE THEIR WAY WELL INTO THE 60S ACROSS THE
REGION ON MON AFTN...WHICH WILL SET US UP FOR YET ANOTHER RELATIVELY
WARM OVERNIGHT PERIOD...W/ LOWS BARELY DROPPING INTO THE 40S.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AN ENCORE OF MON WILL BE ON TUE...AHEAD OF A SIMILAR FRONTAL PASSAGE
ON WED. THE FRONT ON WED MAY BRING A BIT MORE SHOWER ACTIVITY TO THE
AREA...AND MOVE THRU ON WED MRNG. THIS FRONT HOWEVER...WILL BRING A
NOTICEABLE TEMP CHANGE - DROPPING HIGHS AND LOWS DOWN ABOUT 10-15
DEGREES FOR THE NEXT COUPLE OF DAYS. THIS PASSAGE WILL BE AIDED BY A
STRONGER PARENT LOW PRESSURE SYSTEM OVER THE GREAT LAKES THAT WILL
TAP INTO A BETTER COLD CANADIAN AIR FETCH. OVER THE LONGER TERM...IT
APPEARS THAT A SLIGHTLY STRONGER SYSTEM THAN THIS ONE WILL THEN
MAKES AN DIVE TOWARD THE AREA BY THE END OF THE COMING WEEK.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
STRATUS EXPECTED TO HOLD ON LONGER THAN PREV FCST. IFR CIGS/VSBYS AT
IAD/DCA/BWI/MTN WILL IMPROVE GRADUALLY FROM SW TO NE BETWEEN
MIDDAY AND MID AFTN. STRATUS DID NOT REACH MRB/CHO...AND DO NOT
EXPECT IT TO REACH THESE TERMINALS.
VFR SHUD PREVAIL LATE THIS AFTN/EVE. REDEVELOPMENT OF FOG/STRATUS
POSSIBLE AGAIN LATE TNGT AND SUN MRNG...ESPECIALLY OVER THE SAME
LOCATIONS THAT SAW IT THIS MRNG. FCST WILL MORE PESSIMISTIC THAN
CURRENT MODEL GUIDANCE AS GUIDANCE DID NOT CAPTURE THE CURRENT
FOG/STRATUS EVENT WELL /EXCEPT FOR THE HRRR TO SOME EXTENT/.
A WEAK FRONTAL BOUNDARY WILL SLIDE THRU THE AREA DURING THE PREDAWN
HRS MON...SHIFTING WINDS FROM SLY TO NWLY BY THE MID MRNG HRS...
THOUGH THE MAGNITUDES WILL DECREASE. HIGH PRESSURE WILL BUILD FOR
MON AND TUE...THEN A COLD FRONT WILL MOVE THRU ON WED W/ STRONGER
NWLY WINDS GUSTS IN THE 15-25KT RANGE. CONDITIONS WILL SUBSIDE AGAIN
OVERNIGHT AS HIGH PRESSURE BUILDS IN FOR THU AND INTO FRI.
&&
.MARINE...
FOG ACRS WATERS THIS MRNG...SPCLY MID BAY AND LWR PTMC. XPCT
IMPVMNT BY ERY AFTN. OTRW NO SGFNT WX TDA-TNGT. NE WNDS AOB 10
KT TDA BCMG SELY TNGT.
HIGH PRESSURE WILL BE IN PLACE FOR MUCH OF THE WEEK...THOUGH A
COUPLE OF FRONTAL PASSAGES WILL IMPACT THE AREA. THE FIRST FRONT
WILL MAKE LITTLE IMPACT OTHER THAN TO CHANGE THE WIND DIRECTION ON
MON MRNG...FROM SLY TO NWLY. THE FRONT ON WED MRNG WILL BRING THE
SAME CHANGE...THOUGH WINDS WILL BE BREEZY ACROSS THE WATERS FOR MUCH
OF THE DAY. WINDS WILL TAPER OFF HEADING INTO NEXT WEEKEND.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
&&
$$
UPDATE...KLEIN
PREV DISC...HTS/GMS
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
801 AM EST SAT DEC 1 2012
.SYNOPSIS...
DRY WEATHER WILL CONTINUE INTO EARLY SUNDAY. A WEAK COLD FRONT
WILL BRING THE RISK FOR SHOWERS ON SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WEAK UPPER LEVEL RIDGE WILL MOVE THROUGH THE OHIO VALLEY THROUGH
THIS AFTERNOON WITH DRY CONDITIONS EXPECTED.
SATELLITE SHOWS SOME STRATOCU DRIFTING NE ACROSS THE REGION.
MORNING RAOB AND RUC DATA INDICATE SOME OF THIS WILL MOVE EWD
ACROSS THE AREA THROUGH THE AFTERNOON WITH PARTLY SUNNY SKIES.
MORNING RAOB DATA SUPPORTS ABOVE NORMAL HIGHS IN THE 50S TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
UPPER LEVEL FLOW BECOMES ZONAL TONIGHT...AHEAD OF A SHORTWAVE
TROUGH THAT WILL MOVE THROUGH THE UPPER MIDWEST. THIS WAVE WILL
BRING AN INCREASE IN CLOUD COVER LATE TONIGHT. FOLLOWING ON THE
HEELS OF THE SHORTWAVE IS A WEAK COLD FRONT WHICH WILL SLOWLY MOVE
THROUGH THE GREAT LAKES SUNDAY AFTERNOON. WITH VERY LITTLE UPPER
LEVEL SUPPORT ACCOMPANYING THE BOUNDARY...IT WILL HAVE A DIFFICULT
TIME MAKING MUCH SOUTHWARD PROGRESS. BY LATE SUNDAY AFTERNOON...IT
BECOMES DIFFICULT TO FIND THE SFC BOUNDARY AS IT LOSES MUCH OF IT
DEFINITION. MODELS CONTINUE TO SHOW AN AREA OF SHOWERS MOVING
THROUGH SUNDAY...BUT THIS APPEARS TO BE MORE RELATED TO ANOTHER
WEAK SHORTWAVE SWINGING THROUGH LATE SUNDAY. WOULD THINK THE AREA
MOST LIKELY TO SEE RAIN SUNDAY WOULD BE ACROSS THE NORTH...DUE TO
THE POSITIONING OF THE VORT MAX. THERE WILL BE PLENTY OF CLOUD ON
SUNDAY...BUT MOST OF THE SHOWERS WOULD BE SCATTERED. THERE WILL
BE LITTLE IF ANY CHANGE IN AIR MASS...SO THE MILD WEATHER WILL
CONTINUE ON SUNDAY.
UPPER LEVEL RIDGE BUILDS BACK IN ON MONDAY...MEANING ANOTHER DRY
AND MILD DAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MODELS WERE IN GENERAL AGREEMENT ON THE OVERALL PATTERN DURING THE
LONG TERM PERIOD...BUT VARY ON TIMING. PREFERRED THE NAEFS SOLUTION
WHICH WAS SLOWER THAN THE GFS BUT SLIGHTLY FASTER THAN THE ECMWF.
A COLD FRONT WILL MOVE ACROSS THE REGION LATE TUESDAY INTO TUESDAY
NIGHT BRINGING A FEW SHOWERS. COLDER AIR MOVING IN BEHIND THE FRONT
ON WEDNESDAY...COMBINED WITH AN UPPER LEVEL TROF MOVING ACROSS THE
GREAT LAKES...COULD BRING A FEW SNOW SHOWERS TO THE FAR NORTHERN
COUNTIES DURING THE DAY...HOWEVER HIGH PRESSURE SHOULD QUICKLY BUILD
IN ENDING ANY PRECIP.
EXPECT TEMPS WEDNESDAY TO SLOWLY FALL OFF DURING THE LATE MORNING
AND AFTERNOON AS WELL WITH THE CAA. TEMPS SHOULD INCREASE TO ABOVE
NORMAL LEVELS AGAIN BY LATE IN THE WEEK.
ANOTHER COLD FRONT APPROACHES FROM THE WEST FRIDAY AFTERNOON.
&&
.AVIATION /13Z SATURDAY THROUGH WEDNESDAY/...
AN AREA OF MID AND HIGH CLOUDS IN ASSOCIATION WITH A PASSING MID-
LEVEL SYSTEM WILL MOVE THROUGH THE AREA. OTHERWISE...RAGGED HIGH
CLOUDS WILL BE COMMON ACROSS THE REGION...AND WINDS GIVE A WEAK
SURFACE PATTERN WILL BE RATHER LIGHT. AS SUCH...GENERALLY VFR
CONDITIONS SHOULD PREVAIL AT ALL SITES THROUGH SATURDAY.
.OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/...
RESTRICTIONS WILL BE POSSIBLE SUNDAY AFTERNOON AND NIGHT...DUE TO
SHOWER FORMATION ALONG A WEAK EASTBOUND FRONT. A BETTER RESTRICTION
CHANCE WILL ACCOMPANY A STRONG COLD FRONT PASSAGE ON TUESDAY NIGHT...AND
WILL LIKELY PERSIST WITH COLD POOL CLOUDS AND SCATTERED SNOW SHOWERS
WEDNESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BILLINGS MT
350 AM MST SAT DEC 1 2012
.SHORT TERM...VALID FOR TDY AND SUN...
THE PASSAGE OF AN ENERGETIC SHORT WAVE TROUGH SUN AND SUN NIGHT IS
THE MAIN FOCUS OF THE SHORT TERM...AS IT WILL PROVIDE A THREAT FOR
HIGH WINDS FROM LIVINGSTON AND NYE UP TO HARLOWTON...AND HAZARDOUS
WINTER WEATHER IN THE BEARTOOTH/ABSAROKA MOUNTAINS. THE STRONG JET
ASSOCIATED WITH THIS WAVE CAN ALREADY BE SEEN AS AN AREA OF DRYING
APPROACHING THE CA AND OR COASTLINE ON MOISTURE CHANNEL IMAGERY AT
10 UTC.
TODAY...WE DECIDED TO CARRY A DRY FORECAST OVER THE PLAINS...WHICH
COUNTS ON THE SHOWERS NOTED EAST OF BILLINGS DIMINISHING BY 12 UTC
LIKE THE LAST SEVERAL RAP AND HRRR SOLUTIONS SUGGEST. WE FEEL THAT
IDEA IS A GOOD ONE SINCE SATELLITE IMAGERY SHOWS SOME DRYING ALOFT
IN SOUTH CENTRAL MT ALREADY...SIGNALING THE EXIT OF THE WEAK SHORT
WAVE RESPONSIBLE FOR THE SHOWERS. THE 00 UTC MODELS...AND EVEN THE
03 UTC SREF...ALL SUGGEST THE NEXT BATCH OF MOUNTAIN PRECIPITATION
WILL MOVE IN AFTER 18 UTC...SO WE HAVE LIKELY POPS FOR PLACES LIKE
COOKE CITY THIS AFTERNOON AFTER A RELATIVE LULL THIS MORNING. MILD
CONDITIONS WILL CONTINUE IN THE LOWER ELEVATIONS...THOUGH WITH THE
MILES CITY AREA NOT MIXING OUT TOO WELL THE LAST FEW DAYS...WE ARE
NOT ENTIRELY CONFIDENT IN THE DEGREE OF WARMING. WE USED THE BIAS-
CORRECTED 00 UTC MOS CONSENSUS FOR FORECAST HIGHS SINCE THERE WILL
NOT BE A DOWNSLOPE LOW-LEVEL TRAJECTORY TO PUSH HIGHS TOO FAR AWAY
FROM MOS-BASED EXPECTATIONS. FINALLY...WINDS AROUND LIVINGSTON AND
BIG TIMBER WILL PICK UP AGAIN TODAY WITH MIXING...BUT THE FORECAST
SOUNDINGS FOR THOSE LOCATIONS ONLY HAVE ABOUT 45 KT OF WIND WITHIN
THE MIXED LAYER.
TONIGHT...SOME SNOW SHOWERS WILL LIKELY CONTINUE IN THE MOUNTAINS.
SURFACE PRESSURE FALLS WILL RAMP UP IN THE NORTHERN ROCKIES...WITH
GAP-AIDED WINDS LIKELY INCREASING OVERNIGHT AT LIVINGSTON AND NYE.
SUN...SUBSTANTIAL SURFACE PRESSURE FALLS OF 10-15 HPA/6 HOURS WILL
SHIFT EAST ACROSS NORTHERN MT AS A 988-HPA SURFACE LOW DEVELOPS IN
THE LEE OF THE ROCKIES. THIS REFLECTS THE TIGHT LOW- AND MID-LEVEL
HEIGHT GRADIENT THAT WILL GENERATE 700-HPA WINDS OF 70 TO 80 KT IN
PARTS OF SOUTH CENTRAL MT. FORECAST SOUNDINGS SUGGEST AN INVERSION
NEAR THE MOUNTAIN-TOP LEVEL AT LIVINGSTON TO HELP WITH GAP FLOW...
AND THE MET MOS THERE EVEN SHOWS A 49 KT SUSTAINED SPEED AT 18 UTC
SUN. THOSE SOUNDINGS ALSO SUGGEST MIXING SHOULD HAVE ACCESS TO THE
STRONG WINDS OFF THE SURFACE EVEN AFTER 18 UTC...AND IN FACT 500 M
AGL WINDS FROM THE 00 UTC GFS RUN 50+ KT DURING THE AFTERNOON FROM
LIVINGSTON TO BIG TIMBER AND UP TO HARLOWTON...WHICH WAS ENOUGH TO
MAKE US HOIST A HIGH WIND WATCH FOR THAT WHOLE CORRIDOR. THERE MAY
BE SOME SUBSIDENCE TO HELP DRIVE THE WINDS TOO PER OMEGA FIELDS IN
FORECAST SOUNDINGS...AND A 100 KT SOUTHWESTERLY 300-HPA JET SHOULD
ALSO PROVIDE A PERIOD OF SUBSIDENCE AND DEEP LINKAGE AS IT CROSSES
THE REGION IN THE AFTERNOON AND EVENING. STRONG MOUNTAIN-TOP WINDS
ON THE ORDER OF 80+ KT ARE ALSO SUGGESTED IN ALL 00 UTC MODELS. WE
THUS ARE CONCERNED WITH MOUNTAIN WAVE ACTIVITY FOR PLACES LIKE RED
LODGE...BUT MODEL-DERIVED CROSS SECTIONS SHOW ONLY A WEAK CRITICAL
LAYER OF SPEED SHEAR ABOVE THE MOUNTAIN-TOP LEVEL...AND THERE JUST
IS NOT A STRONG DOWNWARD MOMENTUM SIGNATURE SHOWN IN THETA FIELDS.
THUS...WE DECIDED AGAINST A HIGH WIND WATCH FOR RED LODGE...THOUGH
WE NEED TO STRESS THAT RED LODGE MOUNTAIN WILL PROBABLY EXPERIENCE
STRONG WINDS EITHER WAY.
WHERE THE BEARTOOTH AND ABSAROKA MOUNTAINS ARE CONCERNED...WE LEFT
THE WINTER STORM WATCH IN PLAY...WITH SNOW-TO-LIQUID RATIOS ONE OF
THE MAIN UNCERTAINTIES IN THIS EVENT DUE TO THE MILD NATURE OF THE
SOUTHWEST FLOW ALOFT. THE STRONG WINDS MAY STILL CAUSE SOME PRETTY
HIGH IMPACTS IN THE HIGH COUNTRY THOUGH...EVEN IF SNOW AMOUNTS ARE
HELD BELOW THE 12 INCHES USUALLY NEEDED IN 24 HOURS FOR A WARNING.
SUN NIGHT...A SURFACE COLD FRONT WILL CROSS THE AREA...AND WE HAVE
SOME 20 TO 30 POPS IN PLACE EVEN OVER THE PLAINS WITH ITS PASSAGE.
THE 00 UTC GFS REVEALS POTENTIAL FOR A MOUNTAIN WAVE-INDUCED WIND
EVENT AT SHERIDAN...BUT AGAIN THETA FIELDS WOULD SUGGEST THE WINDS
MAY NOT ACTUALLY MAKE IT DOWN TOO FAR OFF THE BIG HORN RANGE. MOST
PAST MOUNTAIN WAVE EPISODES AT SHERIDAN ALSO HAD A JET ORIENTATION
THAT WAS MORE EAST TO WEST THAN THE UPCOMING EVENT...WHICH REDUCES
CONFIDENCE A BIT AS WELL. SCHULTZ
.LONG TERM...VALID FOR MON...TUE...WED...THU...FRI...
TRANQUIL WEATHER PATTERN IS EXPECTED MONDAY THROUGH SATURDAY WITH
VERY GOOD AGREEMENT AMONG THE MEDIUM RANGE GUIDANCE.
POST-FRONTAL CONDITIONS WILL PREVAIL ON MONDAY IN WAKE OF WEAK
PACIFIC COLD FRONT WHICH MOVED THROUGH THE AREA SUNDAY NIGHT.
TEMPERATURES WILL BE SOMEWHAT COOLER ON MONDAY...BUT STILL WELL
ABOVE SEASONAL NORMALS. LEE TROUGHINESS WILL REDEVELOP ON TUESDAY
IN ADVANCE OF NEXT APPROACHING UPPER LEVEL TROUGH FROM THE PACIFIC
NORTHWEST. UPPER LEVEL SHORTWAVE TROUGH TRANSITS THE STATE
WEDNESDAY NIGHT BRINGING A THREAT FOR SCATTERED SHOWERS ACROSS THE
PLAINS OF SOUTHERN MONTANA AND NORTHERN WYOMING. HOWEVER THIS
LOOKS TO BE A QUICK SHOT OF MOISTURE AND RELATIVELY INSIGNIFICANT
AT THIS POINT. THURSDAY WILL BE SLIGHTLY COOLER IN THE WAKE OF
THIS SHORTWAVE TROUGH...WHICH AMPLIFIES UPPER LEVEL TROUGHINESS
OVER THE NORTHERN PLAINS THURSDAY AND INTO FRIDAY. THIS WILL KEEP
FRIDAY SLIGHTLY COOLER AS WELL...BUT AGAIN STILL WELL ABOVE
SEASONAL NORMALS. UPPER FLOW WILL REMAIN ZONAL WITH EMBEDDED WEAK
SHORTWAVE TROUGH SLATED TO MOVE ACROSS THE REGION AGAIN ON
SATURDAY...WHICH WILL KEEP TEMPERATURES CONSISTENT WITH THOSE OF
PRECEDING DAYS. OVERALL PERIOD LOOKS DRY...OTHER THAN
PRECIPITATION THREAT FOR WEDNESDAY NIGHT. MEIER
&&
.AVIATION...
VFR CONDITIONS ARE EXPECTED TO PREVAIL ACROSS THE AREA THROUGH THE
NEXT 24 HOURS. AN AREA OF VERY LIGHT SHOWERS WILL EXIT SOUTHEAST
MONTANA BY MID-MORNING. WINDS WILL BE GENERALLY LIGHT ACROSS THE
AREA...WITH THE EXCEPTION OF THE UPPER YELLOWSTONE VALLEY IN THE
VICINITY OF LIVINGSTON...WHERE SOUTHWEST WINDS INCREASE BY MID
MORNING TO SUSTAINED AROUND 30 KNOTS WITH GUSTS TO 45 KNOTS. MEIER
&&
.PRELIMINARY POINT TEMP/POPS...
TDY SUN MON TUE WED THU FRI
-------------------------------------------------------
BIL 055 039/059 038/050 031/049 035/053 032/041 025/041
1/B 00/N 20/N 00/B 01/B 31/E 11/B
LVM 054 043/057 037/046 033/047 033/053 030/038 019/038
1/N 13/W 33/W 11/N 12/W 31/B 11/B
HDN 056 033/058 032/052 026/048 030/054 029/042 025/040
1/B 00/B 20/N 00/U 01/B 31/E 11/B
MLS 052 031/056 036/049 026/047 029/052 029/039 019/036
1/B 00/B 30/N 00/U 01/B 21/B 11/B
4BQ 056 031/061 036/050 027/049 030/055 030/039 021/037
1/B 00/B 30/N 00/U 01/B 32/W 10/B
BHK 053 029/057 035/048 023/045 028/049 025/035 016/032
1/B 00/B 30/N 00/U 01/B 21/B 10/B
SHR 053 029/056 030/044 020/045 028/050 025/033 020/032
1/B 00/N 22/W 00/U 02/W 44/J 11/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...HIGH WIND WATCH IN EFFECT FROM LATE TONIGHT THROUGH SUNDAY
EVENING FOR ZONES 28-41-42-63-65-66.
WINTER STORM WATCH IN EFFECT FROM SUNDAY MORNING THROUGH LATE
SUNDAY NIGHT FOR ZONE 67.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
723 AM CST SAT DEC 1 2012
.UPDATE...BASED ON LATEST AUTOMATED OBS AT SITES SUCH AS
KEARNEY/HOLDREGE AND VISIBILITY TRENDS FROM LATEST HIGHER-RES
MODELS SUCH AS HRRR AND RAP13...TACKED ON YET ANOTHER ROW OF
COUNTIES TO THE NORTHWEST EDGE OF THE DENSE FOG ADVISORY...WHICH
NOW INCLUDES ALL BUT 5 COUNTIES IN THE FAR WESTERN/NORTHERN CWA.
LATEST THINKING IS THAT FOG MAY BE SLOWER TO VACATE THAN
PREVIOUSLY THOUGHT...AND DAY SHIFT WILL BE MONITORING CLOSELY FOR
A POSSIBLE EXTENSION IN TIME OF THE FOG HEADLINE PAST 10 AM.
OTHERWISE...ONLY UPDATED TEMP/DEWPOINT GRIDS THROUGH THE NEXT
SEVERAL HOURS TO BETTER MATCH OBSERVATIONAL TRENDS. NO OTHER
CHANGES MADE AT THIS TIME.
&&
.PREV DISCUSSION... /ISSUED 600 AM CST SAT DEC 1 2012/
AVIATION...12Z KGRI TAF. AS IT TURNED OUT...CONDITIONS DID IN
FACT DETERIORATE CONSIDERABLY OVER THE PAST FEW HOURS AS A SURGE
OF LOW LEVEL MOISTURE WORKED NORTH INTO THE AREA...WITH LIFR CEILING
NOW IN PLACE...AND VISIBILITY STEADILY DECREASING TOWARD IFR/LIFR
THRESHOLDS AS WELL. AS A RESULT...HAVE TRENDED THE TAF IN A VERY
PESSIMISTIC DIRECTION FOR THE FIRST FEW HOURS THIS MORNING...WITH
VISIBILITY POSSIBLY DROPPING UNDER 1/2SM. ALTHOUGH CONFIDENCE
REMAINS A BIT SHAKY ON WHEN FOG AND LINGERING LOW CLOUDS WILL
BREAK...ESPECIALLY CONSIDERING THAT KGRI WILL RESIDE VERY NEAR THE
INTERFACE BETWEEN LIGHTER FOG TO THE WEST AND MORE WIDESPREAD
DENSE FOG TO THE EAST/SOUTHEAST...HAVE AIMED FOR A RETURN TO VFR
VISIBILITY BY 17Z AS AN APPROACHING SURFACE TROUGH AXIS STARTS
SCOURING OUT FOG...AND A RETURN TO VFR CEILING BY 20Z AS STRATUS
FINALLY SCATTERS OUT. CERTAINLY PREPARE FOR POSSIBLE ADJUSTMENTS
WITHIN A FEW HOURS EITHER SIDE OF THIS THINKING. ONCE VFR
CONDITIONS RETURN TODAY...THEY ARE EXPECTED TO PERSIST THROUGH THE
REMAINDER OF THE PERIOD...AS WESTERLY LOW LEVEL BREEZES SHUNT LOW
CLOUDS OFF TO THE EAST. THESE SURFACE WINDS WILL NOT BE MUCH OF AN
ISSUE THROUGH THE PERIOD...WITH SUSTAINED SPEEDS EXPECTED TO
AVERAGE UNDER 8KT AS DIRECTION GRADUALLY SHIFTS FROM SOUTHERLY TO
WESTERLY.
PREV DISCUSSION... /ISSUED 439 AM CST SAT DEC 1 2012/
UPDATE...HAVE EXPANDED THE DENSE FOG ADVISORY FARTHER NORTH INTO
SOUTH CENTRAL NEB AS LLVL MOISTURE CONTINUES TO SURGE NORTH AND
VSBYS RAPIDLY DROP. CURRENT HEADLINE FOLLOWS CLOSE TO RAP VSBY
PROGS THIS MORNING...BUT WILL CONTINUE TO MONITOR AS TO WHETHER
FURTHER HEADLINE EXPANSION IS NEEDED. 06Z MODELS CONTINUE TO SLOW
PROGRESSION OF TROUGH THIS MORNING AND SUBSEQUENTLY HAVE LOWERED
TEMPS IN OUR EASTERN ZONES FOR THIS AFTN.
PREV DISCUSSION... /ISSUED 312 AM CST SAT DEC 1 2012/
SHORT TERM...TODAY THROUGH MONDAY NIGHT. MAIN FOCUS IS ON FOG
THIS MORNING...AND TEMPERATURES THE NEXT SEVERAL DAYS. THE
PATTERN ALOFT FEATURED MAINLY ZONAL...PROGRESSIVE FLOW ACROSS THE
CONUS WITH EMBEDDED SHORTWAVE TROUGHS. UPSTREAM...A CLOSED LOW
PRESSURE SYSTEM REMAINED ORIENTED OFF THE COAST IN THE PACIFIC
NORTHWEST. AT THE SURFACE...LOW PRESSURE CENTERS WERE LOCATED IN
THE WESTERN DAKOTAS...AND IN SOUTHEAST COLORADO. IN THE SOUTHERLY
LLVL FLOW...MOISTURE IS BEING DRAWN NORTH FM THE SOUTHERN PLAINS
STATES. SFC DPS HAVE RISEN INTO THE LOWER 50S ALREADY IN SOUTHERN
KANSAS. THESE HIGH DPS ARE GREATER THAN NORMAL HIGHS FOR THIS TIME
OF YEAR AND ANOMALY PAGE INDICATES THAT THE 925MB SPECIFIC
HUMIDITIES ARE ROUGHLY 4 STANDARD DEVIATIONS ABOVE NORMAL ACROSS
SOUTHEAST NEBRASKA AND NORTHEAST KANSAS. THE LLVL MOISTURE WILL
CONTINUE TO ADVECT NORTH THRU KS INTO PORTIONS OF CENTRAL/EASTERN
NEBRASKA AHEAD OF SFC TROUGH AXIS EDGING EAST FM THE HIGH PLAINS.
LOW CLOUDS/STRATUS WILL EXPAND NORTHWARD THRU THE OVERNIGHT AND
EARLY MORNING HOURS AND WILL BE KEEPING A CLOSE EYE ON VSBY
RESTRICTIONS IN FOG AS WE ARE ALREADY STARTING TO SEE VSBYS DROP
TO A QUARTER MILE AT TIMES IN NORTH CENTRAL KS AND FAR SOUTHERN
NEB. WILL GO AHEAD AND ISSUE A DENSE FOG ADVISORY FOR OUR
SOUTHEAST ZONES AND MONITOR FOR POSSIBLE HEADLINE EXPANSION.
THE DEEPER LLVL MOISTURE IN OUR SOUTHEAST ZONES AND INCREASING
BOUNDARY LAYER MIXING COULD REALISTICALLY LEAD TO SOME DRIZZLE
DEVELOPMENT AND WILL MENTION FOR A FEW HOURS THIS MORNING. AS WE
HEAD THROUGH THE DAY...THE SURFACE TROUGH AXIS SLOWLY ADVANCES
EASTWARD...REACHING OUR CENTRAL CWA AROUND MIDDAY AND OUR EASTERN
ZONES IN THE LATE AFTN. AS THE TROUGH WORKS EAST...IT WILL SCOUR
THE LLVL MOISTURE EASTWARD. STILL SOME QUESTION ON HOW DENSE/THIN THE
HIGH LEVEL CLOUD COVER WILL BE THIS AFTN WITH MODELS FAIRLY
CONSISTENT THAT THE HIGH CLOUDS WILL THIN/DECREASE AFTER 18Z
TODAY. IN INCREASING INSOLATION THIS AFTN BEHIND SFC TROUGH AND
WESTERLY DOWNSLOPE CONDITIONS...THE WESTERN HALF TO TWO THIRDS OF
OUR CWA SHLD SEE A RATHER NICE DAY WITH HIGHS IN THE 60S.
TEMPERATURES IN OUR EASTERN ZONES WILL BE DEPENDENT UPON THE
TIMING OF THE TROUGH PASSAGE AS LLVL MOISTURE LINGERS LONGER. WILL
PLAY THINGS MORE CONSERVATIVELY HERE WITH COOLER TEMPS...BUT
POTENTIAL DOES EXIST FOR LATE DAY RECOVERY IF TROUGH MOVES THRU
FAST ENOUGH. IF TROUGH DOES NOT MOVE THRU AS QUICK AS
EXPECTED...TEMPERATURES WILL RISE VERY LITTLE.
SUNDAY IS STILL SHAPING UP TO BE A REMARKABLY NICE DAY FOR EARLY
DECEMBER. IN THE DRY...WARM AIRMASS...FORECAST SOUNDINGS INDICATE
DEEP MIXING IN THE AFTN WITH NEGLIGIBLE CLOUD COVER. WESTERLY
DOWNSLOPE WINDS INITIALLY DURING THE DAY WILL TRANSITION SOUTHERLY
WITH DEEPENING SFC LOW IN THE NORTHERN HIGH PLAINS. SOUTHERLY WINDS
INCREASE DURING THE AFTN...NOT OVERLY STRONG PER SE...BUT STEADY
BY LATE AFTN. RIGHT NOW IT LOOKS LIKE WE WILL BE HARD PRESSED NOT
TO SEE TEMPS AT OR ABOVE RECORD HIGHS. CURRENT RECORDS STAND AT
67F FOR GRAND ISLAND AND 68F FOR HASTINGS...BOTH SET IN 1956.
SOMEWHAT SIMILAR TO WHAT IS HAPPENING THIS MORNING WITH THE
INCREASING LLVL MOISTURE...SUNDAY NIGHT WILL ALSO SEE LLVL MOISTURE
WORKING NORTH IN INCREASING LLVL SOUTHERLY FLOW/STRENGTHENING LLVL
JET AHEAD OF APPROACHING SFC TROUGH/COOL FRONTAL BOUNDARY. MODELS
PROG SFC DPS WELL INTO THE 40S FOR SE NEB AND 50S FOR EASTERN KS
AGAIN...WITH OUR EASTERN/SOUTHEAST ZONES ON THE PERIPHERY OF THIS
MAIN MOISTURE AXIS. ANOMALY PAGE AGAIN INDICATES 925MB SPECIFIC
HUMIDITIES 4 STANDARD DEVIATIONS ABOVE NORMAL IN FAR SOUTHEAST
NEBRASKA...NORTHEAST KANSAS...INTO IA/MO. THE ANOMALIES OF 3
STANDARD DEVIATIONS REACH OUR EASTERN ZONES. AGAIN IT LOOKS LIKE
STRATUS DEVELOPMENT IS POSSIBLE FOR OUR EASTERN ZONES...AND SREF
VSBY PROBS INDICATE 50 PCNT CHC FOR VSBYS BELOW ONE MILE ACROSS
OUR EASTERN TIER COUNTIES. WILL NEED TO MONITOR FOR POTENTIAL FOG
DEVELOPMENT...BUT IT DOES APPEAR THAT WINDS WILL BE STEADY ENOUGH
TO PRECLUDE SIGNIFICANT VSBY RESTRICTIONS AND MAY BE MORE OF A
STRATUS/DRIZZLE POTENTIAL ALONG/NEAR OUR FAR EASTERN ZONES.
FRONT CURRENTLY LOOKS TO CROSS OUR CWA MONDAY MORNING...AND BOUNDARY
WILL AGAIN SCOUR THE LLVL MOISTURE. 3HR PRESSURE RISES BEHIND THE
FRONT AVERAGE 3 TO 5MB AND IN TIGHT PRESSURE GRADIENT/DEEP
MIXING...BREEZY/WINDY CONDITIONS DEVELOP. FORECAST SOUNDINGS
SUGGEST MIXING TO AROUND H825 WITH WINDS AT THE TOP OF THE LAYER
BETWEEN 30 AND 35KTS. ATTM EXPECTING SUSTAINED WINDS IN THE 20 TO
25 MPH RANGE WITH GUSTS OVER 30MPH. H85 TEMPS DROP 7C MONDAY
COMPARED TO SUNDAY BEHIND THE FRONT AND IN THE CAA...TEMPS MONDAY
SHLD ONLY REACH THE LOW/MID 50S IN OUR NORTH...WITH UPPER 50S/NEAR
60F IN OUR SOUTH. SFC DPS DROP TO THE TEENS/LOW 20S MONDAY NIGHT
IN THE POST FRONTAL DRIER AIRMASS...AND A 1025MB SFC HIGH BUILDS
IN BEHIND THE FRONT. NIGHT TIME TEMPS WILL BE COOLER THAN EARLIER
IN THE WEEKEND WITH MAINLY 20S EXPECTED.
LONG TERM...TUESDAY DAYTIME THROUGH FRIDAY. ALL IN ALL...VERY
LITTLE NOTICEABLE CHANGE MADE TO THE FORECAST...WITH BY FAR THE MAIN
PERIOD OF CONCERN FOR POSSIBLE RAIN OR SNOW CENTERED FROM THURS
NIGHT INTO FRIDAY MORNING...BUT THIS IS FAR FROM A DONE DEAL.
OTHERWISE...WELL ABOVE NORMAL HIGHS CONTINUE INTO THURSDAY...BEFORE
A COOL DOWN TO NEAR SEASONAL NORMS BY FRIDAY.
TUESDAY INTO TUES NIGHT...HIGH CONFIDENCE IN A DRY 24 HOURS...AS
THE 00Z ECMWF/GFS RUNS ARE IN EXCELLENT AGREEMENT REGARDING THE
BIG PICTURE...AS THE CENTRAL PLAINS LIES UNDER DRY WEST-NORTHWEST
FLOW IN THE WAKE OF A STOUT SHORTWAVE TROUGH TRACKING INTO AND
THROUGH THE GREAT LAKES REGION. AT THE SURFACE...A LIGHT WIND
REGIME WILL BE IN PLACE DURING THE DAY...WHILE TUES NIGHT WILL
BRING MORE OF A STEADY SOUTH BREEZE IN RESPONSE TO A DEVELOPING
HIGH PLAINS LEE TROUGH. NUDGED UP BOTH HIGHS AND LOWS 1-2 DEGREES
IN MOST AREAS...WITH HIGHS GENERALLY MID-UPPER 50S AND LOWS 30-34.
WEDNESDAY/WEDNESDAY NIGHT...THE FLOW ALOFT TURNS VERY ZONAL...AS
THE CENTRAL PLAINS IS BRUSHED BY LOW AMPLITUDE SHORTWAVE
DISTURBANCES WELL TO THE SOUTH OF A MORE ORGANIZED TROUGH TRACKING
ACROSS SOUTHERN CANADA. SOUTHERLY BREEZES WILL PICK UP ANOTHER
NOTCH DURING THE DAY AS THE HIGH PLAINS LEE TROUGH STRENGTHENS
MORE...WITH THIS DAY POSSIBLY TRENDING TOWARD LEGITIMATELY BREEZY.
THE DAY SHOULD REMAIN DRY...ALTHOUGH BOTH MODELS SPIT OUT SOME
LIGHT QPF A FEW HUNDRED MILES NORTH/NORTHEAST OF THE CWA.
TEMP-WISE...THIS STILL LOOKS TO BE THE WARMEST OF THESE 4
DAYS...AND MADE VERY LITTLE CHANGE RANGING FROM UPPER 50S
NORTHEAST TO LOW 60S SOUTHWEST. WED NIGHT...MODELS SUCH AS THE
ECMWF ACTUALLY START SPITTING OUT SOME RAIN SHOWER ACTIVITY ACROSS
PARTS OF THE CWA ALONG AN ADVANCING COLD FRONT...BUT THE GFS/GFS
ENSEMBLE KEEPS THE MAIN SUPPORT FOR PRECIP NORTH OF THE AREA SO
WILL LEAVE THIS PERIOD DRY FOR NOW.
THURSDAY/THURSDAY NIGHT...POSSIBLE PRECIP ENTERS THE
PICTURE...AS MID LEVEL FRONTOGENESIS RAMPS UP OVER THE CENTRAL
PLAINS IN RESPONSE TO SHORTWAVE ENERGY DIGGING SOUTHEAST ALONG THE
SOUTHWEST PERIPHERY OF A PARENT LOW PRESSURE SYSTEM TRACKING
THROUGH SOUTHEAST CANADA. MEANWHILE AT THE SURFACE...A MODEST COLD
FRONT SHOULD CLEAR THE ENTIRE CWA DURING THE DAY...RESULTING IN
HIGH TEMPS 5-10 DEGREES COOLER THAN WEDNESDAY...AND ROUGHLY CLOSE
TO 50 MOST AREAS. PRECIP WISE...FOLLOWED ALLBLEND MODEL CONSENSUS
PROCEDURE WHICH KEPT SLIGHT RAIN CHANCES DURING THE DAY ONLY IN
THE FAR NORTHERN CWA...BUT BLANKETED ALL AREAS WITH 20-30 POPS
DURING THE NIGHT. THIS IS STILL HIGHLY UNCERTAIN HOWEVER...AS EVEN
THE ECMWF ITSELF CONTINUES TO SHOW PLENTY OF RUN-TO-RUN
INCONSISTENCY REGARDING WHETHER THIS IS MORE OF AN ORGANIZED
BANDED-TYPE OF PRECIP EVENT/OR MORE OF A HIT/MISS THING. AS FOR
PRECIP TYPE THURS NIGHT...WENT WITH RAIN OR SNOW WORDING TO IMPLY
THE CONSIDERABLE UNCERTAINTY REGARDING THE LOW LEVEL TEMP
PROFILES...BUT BOTTOM LINE IS THIS CONTINUES TO LOOK LIKE A
RELATIVELY LOW IMPACT EVENT AT THIS POINT.
FRIDAY DAYTIME...THIS FINALLY LOOKS TO BE THE COOLEST DAY ACROSS
THE CWA IN 11 DAYS SINCE NOV. 26TH...AS COLDER AIR CONTINUES TO
FILTER SOUTHWARD ALONG THE SOUTHERN PERIPHERY OF THE LARGER SCALE
TROUGH CENTERED SOMEWHERE FROM THE NORTHERN PLAINS TO SOUTHEAST
CANADA. THAT BEING SAID...THIS IS STILL BY NO MEANS A
BONE-CHILLING DAY FOR EARLY DECEMBER...AND HAVE CONTINUED TO
ADVERTISE HIGHS AT LEAST INTO THE LOW 40S. PRECIP-WISE...WHATEVER
HAPPENS THURS NIGHT COULD LINGER INTO FRIDAY ACROSS KS ZONES PER
ECMWF SOLUTION...AND WILL KEEP A SLIGHT CHANCE OF RAIN OR SNOW
GOING FOR MOST AREAS SOUTH OF THE STATE LINE.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR NEZ041-
047>049-061>064-073>077-082>087.
KS...DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR KSZ005>007-
017>019.
&&
$$
LATEST UPDATE/AVIATION/LONG TERM...PFANNKUCH
PREVIOUS UPDATE/SHORT TERM...FAY
AREA FORECAST DISCUSSION
NWS HASTINGS NE
600 AM CST SAT DEC 1 2012
.AVIATION...12Z KGRI TAF. AS IT TURNED OUT...CONDITIONS DID IN
FACT DETERIORATE CONSIDERABLY OVER THE PAST FEW HOURS AS A SURGE
OF LOW LEVEL MOISTURE WORKED NORTH INTO THE AREA...WITH LIFR CEILING
NOW IN PLACE...AND VISIBILITY STEADILY DECREASING TOWARD IFR/LIFR
THRESHOLDS AS WELL. AS A RESULT...HAVE TRENDED THE TAF IN A VERY
PESSIMISTIC DIRECTION FOR THE FIRST FEW HOURS THIS MORNING...WITH
VISIBILITY POSSIBLY DROPPING UNDER 1/2SM. ALTHOUGH CONFIDENCE
REMAINS A BIT SHAKY ON WHEN FOG AND LINGERING LOW CLOUDS WILL
BREAK...ESPECIALLY CONSIDERING THAT KGRI WILL RESIDE VERY NEAR THE
INTERFACE BETWEEN LIGHTER FOG TO THE WEST AND MORE WIDESPREAD
DENSE FOG TO THE EAST/SOUTHEAST...HAVE AIMED FOR A RETURN TO VFR
VISIBILITY BY 17Z AS AN APPROACHING SURFACE TROUGH AXIS STARTS
SCOURING OUT FOG...AND A RETURN TO VFR CEILING BY 20Z AS STRATUS
FINALLY SCATTERS OUT. CERTAINLY PREPARE FOR POSSIBLE ADJUSTMENTS
WITHIN A FEW HOURS EITHER SIDE OF THIS THINKING. ONCE VFR
CONDITIONS RETURN TODAY...THEY ARE EXPECTED TO PERSIST THROUGH THE
REMAINDER OF THE PERIOD...AS WESTERLY LOW LEVEL BREEZES SHUNT LOW
CLOUDS OFF TO THE EAST. THESE SURFACE WINDS WILL NOT BE MUCH OF AN
ISSUE THROUGH THE PERIOD...WITH SUSTAINED SPEEDS EXPECTED TO
AVERAGE UNDER 8KT AS DIRECTION GRADUALLY SHIFTS FROM SOUTHERLY TO
WESTERLY.
&&
.PREV DISCUSSION... /ISSUED 439 AM CST SAT DEC 1 2012/
UPDATE...HAVE EXPANDED THE DENSE FOG ADVISORY FARTHER NORTH INTO
SOUTH CENTRAL NEB AS LLVL MOISTURE CONTINUES TO SURGE NORTH AND
VSBYS RAPIDLY DROP. CURRENT HEADLINE FOLLOWS CLOSE TO RAP VSBY
PROGS THIS MORNING...BUT WILL CONTINUE TO MONITOR AS TO WHETHER
FURTHER HEADLINE EXPANSION IS NEEDED. 06Z MODELS CONTINUE TO SLOW
PROGRESSION OF TROUGH THIS MORNING AND SUBSEQUENTLY HAVE LOWERED
TEMPS IN OUR EASTERN ZONES FOR THIS AFTN.
PREV DISCUSSION... /ISSUED 312 AM CST SAT DEC 1 2012/
SHORT TERM...TODAY THROUGH MONDAY NIGHT. MAIN FOCUS IS ON FOG
THIS MORNING...AND TEMPERATURES THE NEXT SEVERAL DAYS. THE
PATTERN ALOFT FEATURED MAINLY ZONAL...PROGRESSIVE FLOW ACROSS THE
CONUS WITH EMBEDDED SHORTWAVE TROUGHS. UPSTREAM...A CLOSED LOW
PRESSURE SYSTEM REMAINED ORIENTED OFF THE COAST IN THE PACIFIC
NORTHWEST. AT THE SURFACE...LOW PRESSURE CENTERS WERE LOCATED IN
THE WESTERN DAKOTAS...AND IN SOUTHEAST COLORADO. IN THE SOUTHERLY
LLVL FLOW...MOISTURE IS BEING DRAWN NORTH FM THE SOUTHERN PLAINS
STATES. SFC DPS HAVE RISEN INTO THE LOWER 50S ALREADY IN SOUTHERN
KANSAS. THESE HIGH DPS ARE GREATER THAN NORMAL HIGHS FOR THIS TIME
OF YEAR AND ANOMALY PAGE INDICATES THAT THE 925MB SPECIFIC
HUMIDITIES ARE ROUGHLY 4 STANDARD DEVIATIONS ABOVE NORMAL ACROSS
SOUTHEAST NEBRASKA AND NORTHEAST KANSAS. THE LLVL MOISTURE WILL
CONTINUE TO ADVECT NORTH THRU KS INTO PORTIONS OF CENTRAL/EASTERN
NEBRASKA AHEAD OF SFC TROUGH AXIS EDGING EAST FM THE HIGH PLAINS.
LOW CLOUDS/STRATUS WILL EXPAND NORTHWARD THRU THE OVERNIGHT AND
EARLY MORNING HOURS AND WILL BE KEEPING A CLOSE EYE ON VSBY
RESTRICTIONS IN FOG AS WE ARE ALREADY STARTING TO SEE VSBYS DROP
TO A QUARTER MILE AT TIMES IN NORTH CENTRAL KS AND FAR SOUTHERN
NEB. WILL GO AHEAD AND ISSUE A DENSE FOG ADVISORY FOR OUR
SOUTHEAST ZONES AND MONITOR FOR POSSIBLE HEADLINE EXPANSION.
THE DEEPER LLVL MOISTURE IN OUR SOUTHEAST ZONES AND INCREASING
BOUNDARY LAYER MIXING COULD REALISTICALLY LEAD TO SOME DRIZZLE
DEVELOPMENT AND WILL MENTION FOR A FEW HOURS THIS MORNING. AS WE
HEAD THROUGH THE DAY...THE SURFACE TROUGH AXIS SLOWLY ADVANCES
EASTWARD...REACHING OUR CENTRAL CWA AROUND MIDDAY AND OUR EASTERN
ZONES IN THE LATE AFTN. AS THE TROUGH WORKS EAST...IT WILL SCOUR
THE LLVL MOISTURE EASTWARD. STILL SOME QUESTION ON HOW DENSE/THIN THE
HIGH LEVEL CLOUD COVER WILL BE THIS AFTN WITH MODELS FAIRLY
CONSISTENT THAT THE HIGH CLOUDS WILL THIN/DECREASE AFTER 18Z
TODAY. IN INCREASING INSOLATION THIS AFTN BEHIND SFC TROUGH AND
WESTERLY DOWNSLOPE CONDITIONS...THE WESTERN HALF TO TWO THIRDS OF
OUR CWA SHLD SEE A RATHER NICE DAY WITH HIGHS IN THE 60S.
TEMPERATURES IN OUR EASTERN ZONES WILL BE DEPENDENT UPON THE
TIMING OF THE TROUGH PASSAGE AS LLVL MOISTURE LINGERS LONGER. WILL
PLAY THINGS MORE CONSERVATIVELY HERE WITH COOLER TEMPS...BUT
POTENTIAL DOES EXIST FOR LATE DAY RECOVERY IF TROUGH MOVES THRU
FAST ENOUGH. IF TROUGH DOES NOT MOVE THRU AS QUICK AS
EXPECTED...TEMPERATURES WILL RISE VERY LITTLE.
SUNDAY IS STILL SHAPING UP TO BE A REMARKABLY NICE DAY FOR EARLY
DECEMBER. IN THE DRY...WARM AIRMASS...FORECAST SOUNDINGS INDICATE
DEEP MIXING IN THE AFTN WITH NEGLIGIBLE CLOUD COVER. WESTERLY
DOWNSLOPE WINDS INITIALLY DURING THE DAY WILL TRANSITION SOUTHERLY
WITH DEEPENING SFC LOW IN THE NORTHERN HIGH PLAINS. SOUTHERLY WINDS
INCREASE DURING THE AFTN...NOT OVERLY STRONG PER SE...BUT STEADY
BY LATE AFTN. RIGHT NOW IT LOOKS LIKE WE WILL BE HARD PRESSED NOT
TO SEE TEMPS AT OR ABOVE RECORD HIGHS. CURRENT RECORDS STAND AT
67F FOR GRAND ISLAND AND 68F FOR HASTINGS...BOTH SET IN 1956.
SOMEWHAT SIMILAR TO WHAT IS HAPPENING THIS MORNING WITH THE
INCREASING LLVL MOISTURE...SUNDAY NIGHT WILL ALSO SEE LLVL MOISTURE
WORKING NORTH IN INCREASING LLVL SOUTHERLY FLOW/STRENGTHENING LLVL
JET AHEAD OF APPROACHING SFC TROUGH/COOL FRONTAL BOUNDARY. MODELS
PROG SFC DPS WELL INTO THE 40S FOR SE NEB AND 50S FOR EASTERN KS
AGAIN...WITH OUR EASTERN/SOUTHEAST ZONES ON THE PERIPHERY OF THIS
MAIN MOISTURE AXIS. ANOMALY PAGE AGAIN INDICATES 925MB SPECIFIC
HUMIDITIES 4 STANDARD DEVIATIONS ABOVE NORMAL IN FAR SOUTHEAST
NEBRASKA...NORTHEAST KANSAS...INTO IA/MO. THE ANOMALIES OF 3
STANDARD DEVIATIONS REACH OUR EASTERN ZONES. AGAIN IT LOOKS LIKE
STRATUS DEVELOPMENT IS POSSIBLE FOR OUR EASTERN ZONES...AND SREF
VSBY PROBS INDICATE 50 PCNT CHC FOR VSBYS BELOW ONE MILE ACROSS
OUR EASTERN TIER COUNTIES. WILL NEED TO MONITOR FOR POTENTIAL FOG
DEVELOPMENT...BUT IT DOES APPEAR THAT WINDS WILL BE STEADY ENOUGH
TO PRECLUDE SIGNIFICANT VSBY RESTRICTIONS AND MAY BE MORE OF A
STRATUS/DRIZZLE POTENTIAL ALONG/NEAR OUR FAR EASTERN ZONES.
FRONT CURRENTLY LOOKS TO CROSS OUR CWA MONDAY MORNING...AND BOUNDARY
WILL AGAIN SCOUR THE LLVL MOISTURE. 3HR PRESSURE RISES BEHIND THE
FRONT AVERAGE 3 TO 5MB AND IN TIGHT PRESSURE GRADIENT/DEEP
MIXING...BREEZY/WINDY CONDITIONS DEVELOP. FORECAST SOUNDINGS
SUGGEST MIXING TO AROUND H825 WITH WINDS AT THE TOP OF THE LAYER
BETWEEN 30 AND 35KTS. ATTM EXPECTING SUSTAINED WINDS IN THE 20 TO
25 MPH RANGE WITH GUSTS OVER 30MPH. H85 TEMPS DROP 7C MONDAY
COMPARED TO SUNDAY BEHIND THE FRONT AND IN THE CAA...TEMPS MONDAY
SHLD ONLY REACH THE LOW/MID 50S IN OUR NORTH...WITH UPPER 50S/NEAR
60F IN OUR SOUTH. SFC DPS DROP TO THE TEENS/LOW 20S MONDAY NIGHT
IN THE POST FRONTAL DRIER AIRMASS...AND A 1025MB SFC HIGH BUILDS
IN BEHIND THE FRONT. NIGHT TIME TEMPS WILL BE COOLER THAN EARLIER
IN THE WEEKEND WITH MAINLY 20S EXPECTED.
LONG TERM...TUESDAY DAYTIME THROUGH FRIDAY. ALL IN ALL...VERY
LITTLE NOTICEABLE CHANGE MADE TO THE FORECAST...WITH BY FAR THE MAIN
PERIOD OF CONCERN FOR POSSIBLE RAIN OR SNOW CENTERED FROM THURS
NIGHT INTO FRIDAY MORNING...BUT THIS IS FAR FROM A DONE DEAL.
OTHERWISE...WELL ABOVE NORMAL HIGHS CONTINUE INTO THURSDAY...BEFORE
A COOL DOWN TO NEAR SEASONAL NORMS BY FRIDAY.
TUESDAY INTO TUES NIGHT...HIGH CONFIDENCE IN A DRY 24 HOURS...AS
THE 00Z ECMWF/GFS RUNS ARE IN EXCELLENT AGREEMENT REGARDING THE
BIG PICTURE...AS THE CENTRAL PLAINS LIES UNDER DRY WEST-NORTHWEST
FLOW IN THE WAKE OF A STOUT SHORTWAVE TROUGH TRACKING INTO AND
THROUGH THE GREAT LAKES REGION. AT THE SURFACE...A LIGHT WIND
REGIME WILL BE IN PLACE DURING THE DAY...WHILE TUES NIGHT WILL
BRING MORE OF A STEADY SOUTH BREEZE IN RESPONSE TO A DEVELOPING
HIGH PLAINS LEE TROUGH. NUDGED UP BOTH HIGHS AND LOWS 1-2 DEGREES
IN MOST AREAS...WITH HIGHS GENERALLY MID-UPPER 50S AND LOWS 30-34.
WEDNESDAY/WEDNESDAY NIGHT...THE FLOW ALOFT TURNS VERY ZONAL...AS
THE CENTRAL PLAINS IS BRUSHED BY LOW AMPLITUDE SHORTWAVE
DISTURBANCES WELL TO THE SOUTH OF A MORE ORGANIZED TROUGH TRACKING
ACROSS SOUTHERN CANADA. SOUTHERLY BREEZES WILL PICK UP ANOTHER
NOTCH DURING THE DAY AS THE HIGH PLAINS LEE TROUGH STRENGTHENS
MORE...WITH THIS DAY POSSIBLY TRENDING TOWARD LEGITIMATELY BREEZY.
THE DAY SHOULD REMAIN DRY...ALTHOUGH BOTH MODELS SPIT OUT SOME
LIGHT QPF A FEW HUNDRED MILES NORTH/NORTHEAST OF THE CWA.
TEMP-WISE...THIS STILL LOOKS TO BE THE WARMEST OF THESE 4
DAYS...AND MADE VERY LITTLE CHANGE RANGING FROM UPPER 50S
NORTHEAST TO LOW 60S SOUTHWEST. WED NIGHT...MODELS SUCH AS THE
ECMWF ACTUALLY START SPITTING OUT SOME RAIN SHOWER ACTIVITY ACROSS
PARTS OF THE CWA ALONG AN ADVANCING COLD FRONT...BUT THE GFS/GFS
ENSEMBLE KEEPS THE MAIN SUPPORT FOR PRECIP NORTH OF THE AREA SO
WILL LEAVE THIS PERIOD DRY FOR NOW.
THURSDAY/THURSDAY NIGHT...POSSIBLE PRECIP ENTERS THE
PICTURE...AS MID LEVEL FRONTOGENESIS RAMPS UP OVER THE CENTRAL
PLAINS IN RESPONSE TO SHORTWAVE ENERGY DIGGING SOUTHEAST ALONG THE
SOUTHWEST PERIPHERY OF A PARENT LOW PRESSURE SYSTEM TRACKING
THROUGH SOUTHEAST CANADA. MEANWHILE AT THE SURFACE...A MODEST COLD
FRONT SHOULD CLEAR THE ENTIRE CWA DURING THE DAY...RESULTING IN
HIGH TEMPS 5-10 DEGREES COOLER THAN WEDNESDAY...AND ROUGHLY CLOSE
TO 50 MOST AREAS. PRECIP WISE...FOLLOWED ALLBLEND MODEL CONSENSUS
PROCEDURE WHICH KEPT SLIGHT RAIN CHANCES DURING THE DAY ONLY IN
THE FAR NORTHERN CWA...BUT BLANKETED ALL AREAS WITH 20-30 POPS
DURING THE NIGHT. THIS IS STILL HIGHLY UNCERTAIN HOWEVER...AS EVEN
THE ECMWF ITSELF CONTINUES TO SHOW PLENTY OF RUN-TO-RUN
INCONSISTENCY REGARDING WHETHER THIS IS MORE OF AN ORGANIZED
BANDED-TYPE OF PRECIP EVENT/OR MORE OF A HIT/MISS THING. AS FOR
PRECIP TYPE THURS NIGHT...WENT WITH RAIN OR SNOW WORDING TO IMPLY
THE CONSIDERABLE UNCERTAINTY REGARDING THE LOW LEVEL TEMP
PROFILES...BUT BOTTOM LINE IS THIS CONTINUES TO LOOK LIKE A
RELATIVELY LOW IMPACT EVENT AT THIS POINT.
FRIDAY DAYTIME...THIS FINALLY LOOKS TO BE THE COOLEST DAY ACROSS
THE CWA IN 11 DAYS SINCE NOV. 26TH...AS COLDER AIR CONTINUES TO
FILTER SOUTHWARD ALONG THE SOUTHERN PERIPHERY OF THE LARGER SCALE
TROUGH CENTERED SOMEWHERE FROM THE NORTHERN PLAINS TO SOUTHEAST
CANADA. THAT BEING SAID...THIS IS STILL BY NO MEANS A
BONE-CHILLING DAY FOR EARLY DECEMBER...AND HAVE CONTINUED TO
ADVERTISE HIGHS AT LEAST INTO THE LOW 40S. PRECIP-WISE...WHATEVER
HAPPENS THURS NIGHT COULD LINGER INTO FRIDAY ACROSS KS ZONES PER
ECMWF SOLUTION...AND WILL KEEP A SLIGHT CHANCE OF RAIN OR SNOW
GOING FOR MOST AREAS SOUTH OF THE STATE LINE.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR NEZ048-049-
062>064-074>077-083>087.
KS...DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR KSZ005>007-
017>019.
&&
$$
SHORT TERM/UPDATE...FAY
LONG TERM/AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION
NWS HASTINGS NE
439 AM CST SAT DEC 1 2012
.UPDATE...HAVE EXPANDED THE DENSE FOG ADVISORY FARTHER NORTH INTO
SOUTH CENTRAL NEB AS LLVL MOISTURE CONTINUES TO SURGE NORTH AND
VSBYS RAPIDLY DROP. CURRENT HEADLINE FOLLOWS CLOSE TO RAP VSBY
PROGS THIS MORNING...BUT WILL CONTINUE TO MONITOR AS TO WHETHER
FURTHER HEADLINE EXPANSION IS NEEDED. 06Z MODELS CONTINUE TO SLOW
PROGRESSION OF TROUGH THIS MORNING AND SUBSEQUENTLY HAVE LOWERED
TEMPS IN OUR EASTERN ZONES FOR THIS AFTN.
&&
.PREV DISCUSSION... /ISSUED 312 AM CST SAT DEC 1 2012/
SHORT TERM...TODAY THROUGH MONDAY NIGHT. MAIN FOCUS IS ON FOG
THIS MORNING...AND TEMPERATURES THE NEXT SEVERAL DAYS. THE
PATTERN ALOFT FEATURED MAINLY ZONAL...PROGRESSIVE FLOW ACROSS THE
CONUS WITH EMBEDDED SHORTWAVE TROUGHS. UPSTREAM...A CLOSED LOW
PRESSURE SYSTEM REMAINED ORIENTED OFF THE COAST IN THE PACIFIC
NORTHWEST. AT THE SURFACE...LOW PRESSURE CENTERS WERE LOCATED IN
THE WESTERN DAKOTAS...AND IN SOUTHEAST COLORADO. IN THE SOUTHERLY
LLVL FLOW...MOISTURE IS BEING DRAWN NORTH FM THE SOUTHERN PLAINS
STATES. SFC DPS HAVE RISEN INTO THE LOWER 50S ALREADY IN SOUTHERN
KANSAS. THESE HIGH DPS ARE GREATER THAN NORMAL HIGHS FOR THIS TIME
OF YEAR AND ANOMALY PAGE INDICATES THAT THE 925MB SPECIFIC
HUMIDITIES ARE ROUGHLY 4 STANDARD DEVIATIONS ABOVE NORMAL ACROSS
SOUTHEAST NEBRASKA AND NORTHEAST KANSAS. THE LLVL MOISTURE WILL
CONTINUE TO ADVECT NORTH THRU KS INTO PORTIONS OF CENTRAL/EASTERN
NEBRASKA AHEAD OF SFC TROUGH AXIS EDGING EAST FM THE HIGH PLAINS.
LOW CLOUDS/STRATUS WILL EXPAND NORTHWARD THRU THE OVERNIGHT AND
EARLY MORNING HOURS AND WILL BE KEEPING A CLOSE EYE ON VSBY
RESTRICTIONS IN FOG AS WE ARE ALREADY STARTING TO SEE VSBYS DROP
TO A QUARTER MILE AT TIMES IN NORTH CENTRAL KS AND FAR SOUTHERN
NEB. WILL GO AHEAD AND ISSUE A DENSE FOG ADVISORY FOR OUR
SOUTHEAST ZONES AND MONITOR FOR POSSIBLE HEADLINE EXPANSION.
THE DEEPER LLVL MOISTURE IN OUR SOUTHEAST ZONES AND INCREASING
BOUNDARY LAYER MIXING COULD REALISTICALLY LEAD TO SOME DRIZZLE
DEVELOPMENT AND WILL MENTION FOR A FEW HOURS THIS MORNING. AS WE
HEAD THROUGH THE DAY...THE SURFACE TROUGH AXIS SLOWLY ADVANCES
EASTWARD...REACHING OUR CENTRAL CWA AROUND MIDDAY AND OUR EASTERN
ZONES IN THE LATE AFTN. AS THE TROUGH WORKS EAST...IT WILL SCOUR
THE LLVL MOISTURE EASTWARD. STILL SOME QUESTION ON HOW DENSE/THIN THE
HIGH LEVEL CLOUD COVER WILL BE THIS AFTN WITH MODELS FAIRLY
CONSISTENT THAT THE HIGH CLOUDS WILL THIN/DECREASE AFTER 18Z
TODAY. IN INCREASING INSOLATION THIS AFTN BEHIND SFC TROUGH AND
WESTERLY DOWNSLOPE CONDITIONS...THE WESTERN HALF TO TWO THIRDS OF
OUR CWA SHLD SEE A RATHER NICE DAY WITH HIGHS IN THE 60S.
TEMPERATURES IN OUR EASTERN ZONES WILL BE DEPENDENT UPON THE
TIMING OF THE TROUGH PASSAGE AS LLVL MOISTURE LINGERS LONGER. WILL
PLAY THINGS MORE CONSERVATIVELY HERE WITH COOLER TEMPS...BUT
POTENTIAL DOES EXIST FOR LATE DAY RECOVERY IF TROUGH MOVES THRU
FAST ENOUGH. IF TROUGH DOES NOT MOVE THRU AS QUICK AS
EXPECTED...TEMPERATURES WILL RISE VERY LITTLE.
SUNDAY IS STILL SHAPING UP TO BE A REMARKABLY NICE DAY FOR EARLY
DECEMBER. IN THE DRY...WARM AIRMASS...FORECAST SOUNDINGS INDICATE
DEEP MIXING IN THE AFTN WITH NEGLIGIBLE CLOUD COVER. WESTERLY
DOWNSLOPE WINDS INITIALLY DURING THE DAY WILL TRANSITION SOUTHERLY
WITH DEEPENING SFC LOW IN THE NORTHERN HIGH PLAINS. SOUTHERLY WINDS
INCREASE DURING THE AFTN...NOT OVERLY STRONG PER SE...BUT STEADY
BY LATE AFTN. RIGHT NOW IT LOOKS LIKE WE WILL BE HARD PRESSED NOT
TO SEE TEMPS AT OR ABOVE RECORD HIGHS. CURRENT RECORDS STAND AT
67F FOR GRAND ISLAND AND 68F FOR HASTINGS...BOTH SET IN 1956.
SOMEWHAT SIMILAR TO WHAT IS HAPPENING THIS MORNING WITH THE
INCREASING LLVL MOISTURE...SUNDAY NIGHT WILL ALSO SEE LLVL MOISTURE
WORKING NORTH IN INCREASING LLVL SOUTHERLY FLOW/STRENGTHENING LLVL
JET AHEAD OF APPROACHING SFC TROUGH/COOL FRONTAL BOUNDARY. MODELS
PROG SFC DPS WELL INTO THE 40S FOR SE NEB AND 50S FOR EASTERN KS
AGAIN...WITH OUR EASTERN/SOUTHEAST ZONES ON THE PERIPHERY OF THIS
MAIN MOISTURE AXIS. ANOMALY PAGE AGAIN INDICATES 925MB SPECIFIC
HUMIDITIES 4 STANDARD DEVIATIONS ABOVE NORMAL IN FAR SOUTHEAST
NEBRASKA...NORTHEAST KANSAS...INTO IA/MO. THE ANOMALIES OF 3
STANDARD DEVIATIONS REACH OUR EASTERN ZONES. AGAIN IT LOOKS LIKE
STRATUS DEVELOPMENT IS POSSIBLE FOR OUR EASTERN ZONES...AND SREF
VSBY PROBS INDICATE 50 PCNT CHC FOR VSBYS BELOW ONE MILE ACROSS
OUR EASTERN TIER COUNTIES. WILL NEED TO MONITOR FOR POTENTIAL FOG
DEVELOPMENT...BUT IT DOES APPEAR THAT WINDS WILL BE STEADY ENOUGH
TO PRECLUDE SIGNIFICANT VSBY RESTRICTIONS AND MAY BE MORE OF A
STRATUS/DRIZZLE POTENTIAL ALONG/NEAR OUR FAR EASTERN ZONES.
FRONT CURRENTLY LOOKS TO CROSS OUR CWA MONDAY MORNING...AND BOUNDARY
WILL AGAIN SCOUR THE LLVL MOISTURE. 3HR PRESSURE RISES BEHIND THE
FRONT AVERAGE 3 TO 5MB AND IN TIGHT PRESSURE GRADIENT/DEEP
MIXING...BREEZY/WINDY CONDITIONS DEVELOP. FORECAST SOUNDINGS
SUGGEST MIXING TO AROUND H825 WITH WINDS AT THE TOP OF THE LAYER
BETWEEN 30 AND 35KTS. ATTM EXPECTING SUSTAINED WINDS IN THE 20 TO
25 MPH RANGE WITH GUSTS OVER 30MPH. H85 TEMPS DROP 7C MONDAY
COMPARED TO SUNDAY BEHIND THE FRONT AND IN THE CAA...TEMPS MONDAY
SHLD ONLY REACH THE LOW/MID 50S IN OUR NORTH...WITH UPPER 50S/NEAR
60F IN OUR SOUTH. SFC DPS DROP TO THE TEENS/LOW 20S MONDAY NIGHT
IN THE POST FRONTAL DRIER AIRMASS...AND A 1025MB SFC HIGH BUILDS
IN BEHIND THE FRONT. NIGHT TIME TEMPS WILL BE COOLER THAN EARLIER
IN THE WEEKEND WITH MAINLY 20S EXPECTED.
LONG TERM...TUESDAY DAYTIME THROUGH FRIDAY. ALL IN ALL...VERY
LITTLE NOTICEABLE CHANGE MADE TO THE FORECAST...WITH BY FAR THE MAIN
PERIOD OF CONCERN FOR POSSIBLE RAIN OR SNOW CENTERED FROM THURS
NIGHT INTO FRIDAY MORNING...BUT THIS IS FAR FROM A DONE DEAL.
OTHERWISE...WELL ABOVE NORMAL HIGHS CONTINUE INTO THURSDAY...BEFORE
A COOL DOWN TO NEAR SEASONAL NORMS BY FRIDAY.
TUESDAY INTO TUES NIGHT...HIGH CONFIDENCE IN A DRY 24 HOURS...AS
THE 00Z ECMWF/GFS RUNS ARE IN EXCELLENT AGREEMENT REGARDING THE
BIG PICTURE...AS THE CENTRAL PLAINS LIES UNDER DRY WEST-NORTHWEST
FLOW IN THE WAKE OF A STOUT SHORTWAVE TROUGH TRACKING INTO AND
THROUGH THE GREAT LAKES REGION. AT THE SURFACE...A LIGHT WIND
REGIME WILL BE IN PLACE DURING THE DAY...WHILE TUES NIGHT WILL
BRING MORE OF A STEADY SOUTH BREEZE IN RESPONSE TO A DEVELOPING
HIGH PLAINS LEE TROUGH. NUDGED UP BOTH HIGHS AND LOWS 1-2 DEGREES
IN MOST AREAS...WITH HIGHS GENERALLY MID-UPPER 50S AND LOWS 30-34.
WEDNESDAY/WEDNESDAY NIGHT...THE FLOW ALOFT TURNS VERY ZONAL...AS
THE CENTRAL PLAINS IS BRUSHED BY LOW AMPLITUDE SHORTWAVE
DISTURBANCES WELL TO THE SOUTH OF A MORE ORGANIZED TROUGH TRACKING
ACROSS SOUTHERN CANADA. SOUTHERLY BREEZES WILL PICK UP ANOTHER
NOTCH DURING THE DAY AS THE HIGH PLAINS LEE TROUGH STRENGTHENS
MORE...WITH THIS DAY POSSIBLY TRENDING TOWARD LEGITIMATELY BREEZY.
THE DAY SHOULD REMAIN DRY...ALTHOUGH BOTH MODELS SPIT OUT SOME
LIGHT QPF A FEW HUNDRED MILES NORTH/NORTHEAST OF THE CWA.
TEMP-WISE...THIS STILL LOOKS TO BE THE WARMEST OF THESE 4
DAYS...AND MADE VERY LITTLE CHANGE RANGING FROM UPPER 50S
NORTHEAST TO LOW 60S SOUTHWEST. WED NIGHT...MODELS SUCH AS THE
ECMWF ACTUALLY START SPITTING OUT SOME RAIN SHOWER ACTIVITY ACROSS
PARTS OF THE CWA ALONG AN ADVANCING COLD FRONT...BUT THE GFS/GFS
ENSEMBLE KEEPS THE MAIN SUPPORT FOR PRECIP NORTH OF THE AREA SO
WILL LEAVE THIS PERIOD DRY FOR NOW.
THURSDAY/THURSDAY NIGHT...POSSIBLE PRECIP ENTERS THE
PICTURE...AS MID LEVEL FRONTOGENESIS RAMPS UP OVER THE CENTRAL
PLAINS IN RESPONSE TO SHORTWAVE ENERGY DIGGING SOUTHEAST ALONG THE
SOUTHWEST PERIPHERY OF A PARENT LOW PRESSURE SYSTEM TRACKING
THROUGH SOUTHEAST CANADA. MEANWHILE AT THE SURFACE...A MODEST COLD
FRONT SHOULD CLEAR THE ENTIRE CWA DURING THE DAY...RESULTING IN
HIGH TEMPS 5-10 DEGREES COOLER THAN WEDNESDAY...AND ROUGHLY CLOSE
TO 50 MOST AREAS. PRECIP WISE...FOLLOWED ALLBLEND MODEL CONSENSUS
PROCEDURE WHICH KEPT SLIGHT RAIN CHANCES DURING THE DAY ONLY IN
THE FAR NORTHERN CWA...BUT BLANKETED ALL AREAS WITH 20-30 POPS
DURING THE NIGHT. THIS IS STILL HIGHLY UNCERTAIN HOWEVER...AS EVEN
THE ECMWF ITSELF CONTINUES TO SHOW PLENTY OF RUN-TO-RUN
INCONSISTENCY REGARDING WHETHER THIS IS MORE OF AN ORGANIZED
BANDED-TYPE OF PRECIP EVENT/OR MORE OF A HIT/MISS THING. AS FOR
PRECIP TYPE THURS NIGHT...WENT WITH RAIN OR SNOW WORDING TO IMPLY
THE CONSIDERABLE UNCERTAINTY REGARDING THE LOW LEVEL TEMP
PROFILES...BUT BOTTOM LINE IS THIS CONTINUES TO LOOK LIKE A
RELATIVELY LOW IMPACT EVENT AT THIS POINT.
FRIDAY DAYTIME...THIS FINALLY LOOKS TO BE THE COOLEST DAY ACROSS
THE CWA IN 11 DAYS SINCE NOV. 26TH...AS COLDER AIR CONTINUES TO
FILTER SOUTHWARD ALONG THE SOUTHERN PERIPHERY OF THE LARGER SCALE
TROUGH CENTERED SOMEWHERE FROM THE NORTHERN PLAINS TO SOUTHEAST
CANADA. THAT BEING SAID...THIS IS STILL BY NO MEANS A
BONE-CHILLING DAY FOR EARLY DECEMBER...AND HAVE CONTINUED TO
ADVERTISE HIGHS AT LEAST INTO THE LOW 40S. PRECIP-WISE...WHATEVER
HAPPENS THURS NIGHT COULD LINGER INTO FRIDAY ACROSS KS ZONES PER
ECMWF SOLUTION...AND WILL KEEP A SLIGHT CHANCE OF RAIN OR SNOW
GOING FOR MOST AREAS SOUTH OF THE STATE LINE.
AVIATION...ALTHOUGH THE MAJORITY OF THE PERIOD FEATURES A HIGH
CONFIDENCE IN VFR CEILING/VISIBILITY WITH ONLY VARYING DEGREES OF
PASSING HIGH CLOUDS...A ROUGHLY 4-7 HOUR PERIOD CENTERED BETWEEN
10Z-17Z THIS MORNING IS STILL VERY UNCLEAR REGARDING THE
LIKELIHOOD OF POSSIBLE MVFR/IFR CEILING AND OR/VISIBILITY...AND
CONFIDENCE IS ADMITTEDLY QUITE LOW. IN SHORT...MODELS AND
NUMERICAL GUIDANCE CONTINUE TO OFFER A WIDE RANGE OF SOLUTIONS
RANGING FROM NO WORSE THAN A LIGHT FOG WITH NO LOW CEILING...TO
POTENTIALLY DENSE FOG AND AT LEAST AN IFR CEILING IF NOT WORSE.
FOR NOW WILL CONTINUE TO PLAY A MIDDLE GROUND BETWEEN THESE TWO
EXTREMES...AS KGRI WILL LIKELY END UP ALONG THE WESTERN EDGE OF
THE AREA MOST FAVORED FOR POOR AVIATION CONDITIONS...WHICH ARE
MORE FAVORED FARTHER EAST. STAY TUNED FOR PLENTY OF FINE-TUNING
OVER THE NEXT 12 HOURS. OTHERWISE...ONCE ANY POSSIBLE LOW CLOUDS
VACATE BY MID-DAY OR SO...SHOULD BE A SOLID RETURN TO LEGITIMATE
VFR CONDITIONS AS AN INVADING SURFACE TROUGH SCOURS OUT THIS LOW
LEVEL MOISTURE. SURFACE WINDS SHOULD NOT BE A MAJOR ISSUE...WITH
SUSTAINED SPEEDS EXPECTED TO AVERAGE UNDER 12KT THROUGH THE ENTIRE
PERIOD...ALTHOUGH DIRECTION WILL SHIFT FROM SOUTHERLY THIS MORNING
TO WEST-NORTHWEST THIS AFTERNOON AS THE TROUGH AXIS MOVES IN.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR NEZ048-049-
062>064-074>077-083>087.
KS...DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR KSZ005>007-
017>019.
&&
$$
SHORT TERM...FAY
LONG TERM/AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1115 PM CST FRI NOV 30 2012
.UPDATE...
.AVIATION...
VFR IS EXPECTED ALL AREAS OVERNIGHT THROUGH SATURDAY EVENING.
THE RAP MODEL SUGGESTS SOME PATCHY FOG OR
STRATUS...MVFR...CREEPING INTO FRONTIER...CUSTER AND
WHEELER COUNTIES BETWEEN 09Z AND 14Z. IF THIS CONDITION
DEVELOPS...WEST WINDS DEVELOPING SATURDAY MORNING WILL PUSH IT
QUICKLY EAST OF THE AREA. OTHERWISE...SCT-BKN HIGH LEVEL CLOUDINESS
FROM A LARGE PACIFIC STORM SYSTEM WILL CONTINUE TO MOVE ACROSS THE
FCST AREA THROUGH SATURDAY EVENING.
&&
.PREV DISCUSSION... /ISSUED 554 PM CST FRI NOV 30 2012/
UPDATE...
AVIATION...
SFC OBS FROM SERN KS AND OUTPUT FROM THE RAP MODEL INDICATE
STRATUS AND MVFR CIGS COULD MOVE INTO FRONTIER...CUSTER AND
WHEELER COUNTIES BETWEEN 11Z AND 16Z SATURDAY. OTHERWISE...VFR IS
EXPECTED ALL AREAS.
PREV DISCUSSION... /ISSUED 519 PM CST FRI NOV 30 2012/
UPDATE...
AVIATION...
VFR IS EXPECTED ALL AREAS OVERNIGHT THROUGH SATURDAY.
SCT-BKN HIGH LEVEL CLOUDINESS FROM A LARGE PACIFIC STORM SYSTEM WILL
CONTINUE TO MOVE ACROSS THE FCST AREA THROUGH SATURDAY.
PREV DISCUSSION... /ISSUED 310 PM CST FRI NOV 30 2012/
SYNOPSIS...
H5 ANALYSIS THIS MORNING HAS A BROAD AREA OF LOW PRESSURE OFF THE
COAST OF BRITISH COLUMBIA WITH A SECOND LOW LOCATED OVER NORTH
CENTRAL CANADA. A JET STREAK EXTENDED FROM NORTHERN CALIFORNIA INTO
NWRN MT THIS MORNING WITH A SECOND JET STREAK EXTENDING FROM SRN
QUEBEC INTO THE CANADIAN MARITIMES. WV IMAGERY...AND IR IMAGERY
CONTINUES TO INDICATE ABUNDANT TROPICAL MOISTURE WORKING INTO
CENTRAL AND NRN CALIFORNIA...AS WELL AS OREGON AND WASHINGTON
STATE...AND EXTENDED EAST TO NEVADA...IDAHO AND MONTANA. HIGH LEVEL
CLOUDINESS HAS EXITED CENTRAL AND WESTERN NEBRASKA EARLIER THIS
MORNING LEADING TO MOSTLY SUNNY SKIES THIS AFTERNOON. ANOTHER BATCH
OF BROKEN TO OVERCAST HIGH CLOUDINESS CONTINUES TO PUSH INTO THE
CENTRAL AND NORTHERN ROCKIES THIS AFTERNOON AND WILL ARRIVE ACROSS
THE CENTRAL AND NORTHERN PLAINS LATER THIS EVENING. TEMPERATURES AS
OF 2 PM CST RANGED FROM 47 AT O`NEILL...TO 60 AT OGALLALA AND
THEDFORD.
DISCUSSION...
SHORT RANGE...TONIGHT THROUGH MONDAY...MAIN FORECASTING CHALLENGES
CONTINUE TO REVOLVE AROUND TEMPERATURES AND THE IMPACTS OF HIGH
CLOUDINESS ON THEM. IN ADDITION...WINDS AND WIND SPEEDS IN
ASSOCIATION WITH A COLD FROPA MONDAY CONTINUE TO BE PROBLEMATIC.
FOR TONIGHT AND SATURDAY...SKIES WILL TRANSITION TO MOSTLY CLOUDY
LATER TONIGHT AS ABUNDANT UPPER LEVEL MOISTURE AND HIGH CLOUDINESS
STREAMS INTO THE REGION FROM THE CENTRAL AND NORTHERN ROCKIES. NO
PRECIPITATION IS EXPECTED THOUGH AS VERY DRY CONDITIONS REMAIN BLO
15000 FT AGL. WITH ABUNDANT CLOUD COVER...OVERNIGHT LOWS WILL BE
MILD WITH READINGS MAINLY IN THE LOWER 30S. DID DECIDE TO GO WITH
UPPER 20S IN THE PLATTE RIVER VALLEY THANKS TO DRY AIR AND LIGHT
WESTERLY WINDS...WHICH ALLOW TEMPS TO TANK THIS EVENING AHEAD OF THE
ARRIVAL OF CLOUD COVER. CLOUDS WILL TRANSITION EAST QUICKLY ON
SATURDAY AND ARE EXPECTED TO BE EAST OF THE FORECAST AREA BY LATE
MORNING. LOW PRESSURE AND AN ASSOCIATED SURFACE TROUGH OF LOW
PRESSURE WILL TRACK INTO THE EASTERN DAKOTAS AND EASTERN NEBRASKA ON
SATURDAY...RESULTING IN WESTERLY WINDS ACROSS WESTERN AND NORTH
CENTRAL NEBRASKA SATURDAY AFTERNOON. THE COMBINATION OF FULL
SUN...WESTERLY DOWN SLOPING WINDS...AND DRY AIR...WILL ALLOW TEMPS
TO CLIMB QUICKLY INTO THE UPPER 50S AND LOWER 60S BY MIDDAY
SATURDAY. HIGHS ARE EXPECTED TO REACH THE UPPER 60S TO NEAR 70 IN
THE SOUTHWEST...WITH LOWER TO MID 60S EXPECTED ELSEWHERE.
FYI...RECORD HIGHS TOMORROW FOR VALENTINE...NORTH PLATTE AND
IMPERIAL ARE 74...71 AND 72 RESPECTIVELY WITH 68 BEING THE RECORD AT
BROKEN BOW.
WEAK HIGH PRESSURE WILL BUILD INTO CENTRAL NEBRASKA SATURDAY NIGHT.
CLEAR SKIES...LIGHT WINDS AND DRY AIR...WILL ALLOW LOWS TO DROP
QUICKLY INTO THE UPPER 20S TO NEAR 30. INSERTED SOME MID 20S IN THE
PLATTE RIVER VALLEY AND WESTERN SAND HILLS...THANKS TO LIGHT
WESTERLY WINDS AND A GOOD SETUP FOR COLD AIR DRAINAGE. ON
SUNDAY...HIGH PRESSURE WILL DRIFT EAST OF THE AREA...WITH A LEE SIDE
TROUGH OF LOW PRESSURE DEVELOPING ACROSS THE PANHANDLE...EASTERN
WYOMING AND EASTERN COLORADO...ALLOWING SRLY WINDS TO INCREASE. THE
COMBINATION OF DECENT MIXING AND H85 TEMPS OF 12 TO 15C...WILL PUSH
AFTERNOON HIGHS INTO THE MID AND UPPER 60S.
A COLD FRONT WILL APPROACH THE FORECAST AREA SUNDAY NIGHT. SRLY
WINDS WILL CONTINUE EAST OF THE FRONT AND ARE NOT EXPECTED TO
TOTALLY DECOUPLE. THIS WILL LEAD TO LOWS IN THE 30S FOR SUNDAY
NIGHT. ON MONDAY THE BEFORE MENTIONED COLD FRONT WILL TRACK ACROSS
THE REGION. DECENT NWRLY WINDS WILL DEVELOP WITH PASSAGE OF THIS
FEATURE AND MAY BECOME STRONG BY MIDDAY MONDAY. BASED ON GFS AND NAM
BUFKIT SOUNDINGS...THERE IS A SMALL THREAT FOR WIND GUSTS OVER 40
MPH MID DAY MONDAY. ATTM THE GREATEST THREAT FOR WINDS OF THIS
MAGNITUDE IS OVER NORTHERN NEBRASKA...WHERE COLD AIR ADVECTION WILL
BE STRONGEST BEHIND THE FRONT. FURTHER SOUTH AND WEST...COLD AIR
ADVECTION WILL BE MUCH WEAKER...LIMITING GUST POTENTIAL MONDAY
AFTERNOON. HIGHS WILL BE COOLER WITH READINGS IN THE UPPER 40S AND
50S EXPECTED...WHICH IS STILL 10 TO 15 DEGREES ABOVE CLIMO.
LONG RANGE...MONDAY NIGHT THROUGH FRIDAY...MILD AND DRY WEATHER WILL
BEGIN THE EXTENDED PERIOD...WITH HIGHS WELL INTO THE 50S AND
POSSIBLE NEAR 60 DEGREES TUESDAY AND WEDNESDAY. THE WEATHER WILL
BEGIN TO CHANGE THURSDAY AS A STRONG SHORTWAVE TROUGH MOVES ACROSS
SOUTHERN CANADA AND THE NORTHERN PLAINS. THIS WILL DRIVE A COLD
FRONT THROUGH THE AREA...WITH A HYBRID OF PACIFIC AND ARCTIC AIR
INTRUDING THE AREA BEHIND THE FRONT ON FRIDAY. THE COLDEST /MOST OF
THE ARCTIC/ AIR IS EXPECTED TO STAY NORTHEAST OF THE AREA...SO WHILE
IT WILL BE COLDER FRIDAY HIGHS WILL ONLY BE SLIGHTLY BELOW NORMAL.
ALL INDICATIONS ARE THAT CONDITIONS WILL WARM AGAIN DURING THE
WEEKEND JUST BEYOND THE FORECAST PERIOD.
PRECIPITATION CHANCES ARE SMALL BUT POSSIBLE ON THURSDAY AFTER THE
FRONTAL PASSAGE. AREA IS IN THE RIGHT REAR QUADRANT OF A SIGNIFICANT
JET STREAK...AND SOME DECENT FRONTOGENESIS DEVELOPS ACROSS THE AREA.
SO WILL CONTINUE THE SLIGHT CHANCES FOR RAIN AND SNOW.
AVIATION...
NO AVIATION CONCERNS OVER THE NEXT 24 HOURS. ONLY MID TO HIGH
LEVEL CLOUDS ARE EXPECTED. WINDS WILL BE SOUTHERLY AROUND 10 KTS
THROUGH THE EVENING. WINDS AT KVTN WILL REMAIN ELEVATED OUT OF
THROUGH THE NIGHT AS A SFC LOW PRESSURE PASSES THROUGH THE
DAKOTAS. FRONT PASSES THROUGH THE AREA TOMORROW MORNING WITH WINDS
SWITCHING TO WEST NORTHWEST.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM/EXTENDED...MASEK
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1243 AM EST SAT DEC 1 2012
.SYNOPSIS...
A FRONT WILL CROSS THROUGH THE FINGER LAKES AND MOHAWK VALLEY
TONIGHT. SOME LIGHT SNOW AND FLURRIES WILL OCCUR IN THE VICINITY
OF THE FRONT. COLD AIR WILL HANG UP AGAINST THE CATSKILLS AND
POCONOS OVERNIGHT...WHICH ALONG WITH A MOISTENING LOWER
ATMOSPHERE...WILL LEAD TO PATCHY FREEZING DRIZZLE OR A LIGHT
WINTRY MIX FOR SOME LOCATIONS INTO SATURDAY MORNING...ESPECIALLY
SULLIVAN AND PIKE COUNTIES. THOUGH SOME SHOWERS WILL MOVE IN
SUNDAY...ABOVE NORMAL TEMPERATURES ARE EXPECTED INTO EARLY NEXT
WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
10 PM UPDATE...
NO SIGNS OF FRZG PCPN DVLPNG ACRS THE SE AT THIS TIME. HV ISSUED A
SPECIAL WX STATEMENT FOR BLACK ICE FOR THE SRN TIER AND A ROW OF
CNTYS JUST TO THE NORTH, WHERE SNOW MELTED THIS AFTN AND RE-FROZE
ON ROADWAYS.
NO CHGS NEEDED TO FCST FOR NOW.
PREV DISCUSSIONS BLO...
830 PM UPDATE...
STILL A CONVOLUTED WX PATTERN IN PLACE FOR TONIGHT. LIGHT SNOW IS
OCCURRING ALONG THIS BNDRY INTO THE FINGER LKS AND MOHAWK VLY. H5
S/WV HAS PASSED AND LIFTED THE FRONTAL BNDRY NORTH OF THE SRN
TIER, BRINGING AN END TO THE SNOW FOR TONIGHT. MAIN QUESTION FOR
TONIGHT IS HOW MUCH DRIZZLE AND/OR PCPN WL THE CATSKILLS AND
POCONOS SEE OVRNGT. CHECKING THE FORT DIX VAD WIND PROFILE FM THE
JERSEY COAST DOES NOT GIVE MUCH CONFIDENCE TO SERLY FLOW KICKING
IN, AS IT CONTS TO RMN NRLY FLOW. HWVR, FURTHER NORTH JUST TO THE
SOUTH OF THE WMFNT, I.E KBGM, SERLY FLOW IS WELL-ESTABLISHED.
SO QUESTION IS WL THIS BE ENUF TO GENERATE DRIZZLE AS THE ATLANTIC
IS ESSENTIALLY CLOSED OFF? MODEL SNDGS AT KMSV PER 18Z NAM
INDICATES A SATURATED LOW-LVL ATMOSPHERE UP THRU ABOUT H9 THEN IS
QUESTIONABLE FURTHER ALOFT. RAP INDICATES SATURATED LAYER NEVER
MAKES IT UP TO H9. WL THIS BE ENUF TO GENERATE ANY DRIZZLE OR
STRICTLY A FRZG FOG SCENARIO. QPF FIELDS FM 18Z NAM INDICATE SOME
PCPN MAY FORM FROM SULLIVAN CNTY INTO SRN LUZERNE CNTY, LIKELY DUE
TO OROGRAPHIC AFFECTS. THEREFORE, THE QUESTION BCMS SHUD WE EXPAND
THE ADVISORY WEST EVEN IF WE ARE NOT CONVINCED IT WL BE FZDZ? FOR
NOW WL PASS ON CONCERNS TO THE NEXT SHIFT TO KEEP A CLOSE EYE ON
ANY DVLPMNT BUT PLAN TO KEEP THINGS AS IS FOR THE TIME BEING. WITH
AREAS OF FZDZ IN SULLIVAN/PIKE CNTYS AND PATCHY FZDZ FURTHER WEST
INTO THE POCONOS.
ONLY MINOR TWEAKS TO HRLY T/TD/WIND TRENDS.
4 PM UPDATE...
BAND OF LIGHT SNOW IN IMMEDIATE VICINITY OF FRONT INITIALLY
STALLED OUT AROUND THE TWIN TIERS...IS FINALLY BEGINNING TO EDGE
NORTH AS WAVE FINISHES PASSING ALOFT...AND THE BOUNDARY IS
BECOMING A WARM FRONT. WHERE THINGS LINED UP JUST
RIGHT...GENERALLY ALONG THE SOUTHERN TIER OF NEW YORK...THE FRONT
WAS ABLE TO SQUEEZE OUT AN INCH OR SO OF SNOW...WHEREAS ELSEWHERE
THE COLUMN HAS BEEN TOO DRY. THE THINNING BAND OF SNOW WILL
CONTINUE TO MOVE NORTH WITH THE WARM FRONT THROUGH FINGER
LAKES/MOHAWK VALLEY THIS EVENING.
AFTER THE WAVE ALOFT MOVES THROUGH...WE LOSE THE DEEPER MOISTURE.
MEANWHILE...STRONG SURFACE HIGH WILL MOVE OVER FROM QUEBEC INTO
MAINE...WITH FLOW AROUND IT SETTING UP COLD AIR DAMMING AGAINST
THE MOUNTAINS. NAM MODEL SOUNDING ESPECIALLY MONTICELLO AREA SHOW
THERMAL PROFILE THAT LATE TONIGHT LOSES ABILITY TO INTRODUCE ICE
CRYSTALS FROM ABOVE /BECAUSE TEMPERATURES WARMER THAN MINUS-8
CELSIUS WITHIN THE SHALLOWER SATURATED LAYER/. COLD AIR DAMMING
AT SURFACE LOOKS LIKELY TO KEEP SULLIVAN/PIKE COUNTIES BELOW
FREEZING. THUS WE HAVE A FAVORABLE SET UP FOR AREAS OF FREEZING
DRIZZLE...WITH AT LEAST A CHANCE OF VERY LIGHT WINTRY MIX
/SNOW...SLEET...FREEZING RAIN/. WINTER WEATHER ADVISORY HAS BEEN
HOISTED FOR 1AM-10AM SATURDAY FOR THAT REASON. ACTUAL PRECIPITATION
AMOUNTS WILL BE MINIMAL...BUT EVEN A VERY LIGHT GLAZE OF ICE FROM
FREEZING DRIZZLE IS CAPABLE OF PRODUCING HAZARDOUS TRAVEL
CONDITIONS. WE WILL BE MONITORING CLOSELY TO SEE IF OTHER COUNTIES
MAY NEED TO BE INCLUDED. EASTERN EDGES OF DELAWARE-OTSEGO-WAYNE-
ONEIDA COUNTIES COULD POTENTIALLY HAVE AT LEAST PATCHY FREEZING
DRIZZLE.
ON SATURDAY...CENTRAL TO WESTERN CWA LOOKS DRY WITH WARMING
TEMPERATURES. HOWEVER...CONTINUED SOUTHEAST LOW LEVEL FLOW AGAINST
CATSKILLS/POCONOS WILL HOLD TEMPERATURES BACK IN THE SOUTHEAST.
BIGGEST CONCERN AT THIS TIME IS WHETHER PATCHY FREEZING DRIZZLE
WILL BE ABLE TO PERSIST BEYOND 10 AM...BUT HOPEFULLY DIURNAL
HEATING WILL MITIGATE THAT...BUT THERE IS UNCERTAINTY.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY/...
4 PM UPDATE...
WARM AIR ADVECTION CONTINUES SATURDAY NIGHT INTO SUNDAY...TO THE
POINT THAT A GOOD PART OF THE AREA /ESPECIALLY WESTERN/ SHOULD
MANAGE TO GET INTO 50S FOR HIGHS SUNDAY. WEAKENING COLD FRONT
WILL SPREAD SHOWERS WEST TO EAST SUNDAY AFTERNOON AND
EVENING...BUT TEMPERATURES WILL BE WARM ENOUGH FOR ALL RAIN. ONLY
EXPECTING A FEW TENTHS OF AN INCH AT BEST WITH BRISKNESS OF FLOW
ALOFT. VERY BRIEF SLIGHT COLD AIR ADVECTION SUNDAY NIGHT...QUICKLY
NEUTRALIZES ALLOWING TEMPERATURES MONDAY TO BE NEAR OR ABOVE HIGHS
FROM SUNDAY. WEAK SURFACE HIGH PRESSURE TAKES CHARGE
MONDAY...WHICH FOR MOST IF NOT ALL WILL KEEP THE WEATHER DRY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
415 PM UPDATE...
IT WILL BE MILD AND QUIET INTO MONDAY EVENING, BEFORE A STORM
SYSTEM MOVING THROUGH LOWER ONTARIO PULLS A COLD FRONT INTO NY/PA.
THIS WILL CAUSE RAIN SHOWERS TUESDAY AND TUESDAY NIGHT. SOME WET
SNOW SHOWERS WILL BE POSSIBLE EARLY WEDNESDAY MORNING AS -4C 850MB
ISOTHERM CROSSES THE I-81 CORRIDOR.
TEMPERATURES WILL REMAIN COOL INTO EARLY THURSDAY. HOWEVER THE GFS
IS NOW FORECASTING A NEW RIDGE TO BUILD THURSDAY AFTERNOON INTO
FRIDAY, POTENTIALLY RESULTING IN ANOTHER WARMING TREND.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
WRM FNT OVER THE NRN ZONES BRINGING MVFR CIGS AND VSBY TO RME WILL
LFT NWRD ENDING THE SNOW THERE. OTRW...PLENTLY OF LEFTOVER LL
MOISTURE ASISISTED BY A SELY FLOW BRINGING A MARINE LYR INTO THE
AREA. THIS WILL LWR CIGS INTO THE IFR RANGE SOME STATIONS...WITH
MVFR VSBYS. XPCT SOME IMPRVMT AFT 12Z BUT WITH CLDS AND LOW SUN
ANGLE...WILL BE DFCLT TO MIX OUT MUCH WITH CIGS RISIONG SLOWLY.
XPCT CIGS TO LWR ONCE AGAIN AFT 00Z AS WE STABILIZE.
OUTLOOK...
SUN...MVFR IN RAIN SHOWERS MAINLY DURING THE AFTERNOON AND
OVERNIGHT PERIOD.
MONDAY...VFR.
TUESDAY...FROPA WITH MVFR IN RAIN
SHOWERS DURING THE AFTERNOON/EVENING.
WEDNESDAY...MVFR IN RAIN.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
PAZ048.
NY...WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
NYZ062.
&&
$$
SYNOPSIS...MDP/PVN
NEAR TERM...MDP/PVN
SHORT TERM...MDP
LONG TERM...DJP
AVIATION...DGM
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
941 PM EST SUN DEC 2 2012
.SYNOPSIS...
WELL ABOVE NORMAL TEMPERATURES ARE EXPECTED THROUGH THE EARLY PART
OF THIS WEEK AS HIGH PRESSURE DRIFTS ACROSS THE AREA. A COLD FRONT
WILL CROSS THE EASTERN CAROLINAS ON WEDNESDAY AND MAY BRING A FEW
SHOWERS. NEAR TO SLIGHTLY BELOW NORMAL TEMPERATURES ARE EXPECTED
BEHIND THE COLD FRONT FOR LATE WEEK. UNSETTLED WEATHER MAY RETURN
NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 930 PM SUNDAY...TEMPERATURES NEAR THE COAST HAVE FALLEN
QUICKLY THIS EVENING AND ALREADY ARE WITHIN A COUPLE DEGREES OF
FORECAST LOWS. FARTHER INLAND WHERE STRATOCUMULUS CLOUDS HAVE BEEN
MORE PERVASIVE TEMPERATURES ARE ACTUALLY A COUPLE DEGREES HIGHER
THAN WAS FORECAST FOR 02Z. STANDARD INFRARED SATELLITE IS NOT
SHOWING MUCH OF THE CLOUD COVER INLAND...HOWEVER THE 11-3.9 MICRON
DIFFERENCE IMAGERY IS SHOWING SCATTERED TO BROKEN STRATOCUMULUS
EXTENDING FROM FLORENCE NORTHEASTWARD ACROSS LUMBERTON AND
ELIZABETHTOWN. THIS IS AT LEAST 40-50 MILES FARTHER NORTH THAN WHERE
THE 18Z SYNOPTIC MODELS AND THE LATEST SEVERAL RUC RUNS INDICATED
MAXIMUM ISENTROPIC LIFT WOULD OCCUR. EARLIER SHOWER ACTIVITY HAS
DISSIPATED WITH STABILIZATION OF THE LOWER TROPOSPHERE...AND THERE
IS NO IMPETUS FOR ADDITIONAL SHOWER ACTIVITY THROUGH THE NIGHT.
WITH TEMPERATURE-DEWPOINT SPREADS AT THE SURFACE CLOSING UP TO ZERO
AT THE COAST...TEMPERATURE CURVES SHOULD FLATTEN OUT SHORTLY. ANY
STRATOCUMULUS ADVECTING EASTWARD FROM POINTS FARTHER INLAND COULD
ACTUALLY CAUSE A TEMPORARY RISE IN SURFACE TEMPERATURE. THE BIGGEST
QUESTION FOR THE REMAINDER OF THE NIGHT IS FOG. VISIBILITIES ARE
ALREADY DROPPING AT GEORGETOWN...CONWAY...AND IN NORTH MYRTLE BEACH.
FOG SHOULD BECOME MORE WIDESPREAD OVER THE NEXT SEVERAL HOURS...BUT
WILL AVOID AREAS WITH RESTRICTED RADIATIONAL COOLING FROM
SUBSTANTIAL CLOUD COVER. IF A DENSE FOG ADVISORY BECOMES NEEDED
OVERNIGHT THE MOST LIKELY LOCATIONS WOULD BE GEORGETOWN AND HORRY
COUNTIES IN SOUTH CAROLINA THROUGH COASTAL SOUTHEASTERN NORTH
CAROLINA. PREVIOUS DISCUSSION FROM 630 PM FOLLOWS...
TEMPERATURES AND DEWPOINTS WILL BOTH REMAIN ABOVE NORMAL FOR
DECEMBER AS A NEARLY-SUBTROPICAL AIRMASS IS LIFTED NORTH BY HIGH
PRESSURE LOCATED JUST OFFSHORE. ISOLATED SHOWERS JUST NORTH OF
FLORENCE ARE THE RESULT OF A POCKET OF INSTABILITY BETWEEN 850 AND
700 MB AIDED BY WEAK ISENTROPIC LIFT ALONG THE 295K ISENTROPIC
SURFACE. ALTHOUGH THE INSTABILITY IS FORECAST TO DISSIPATE THIS
EVENING...ISENTROPIC LIFT IS EXPECTED TO CONTINUE ALONG 295K THETA
WHICH SHOULD KEEP SCATTERED TO BROKEN STRATOCUMULUS CLOUDS IN
PLACE...ESPECIALLY FROM FLORENCE EAST ACROSS MYRTLE BEACH INTO
SOUTHPORT.
WITH SUCH RICH BOUNDARY LAYER MOISTURE UNDERNEATH THE ISENTROPIC
LIFT ALOFT...IT WILL NOT TAKE LONG FOR RELATIVE HUMIDITY DOWN HERE
AT THE SURFACE TO APPROACH 100 PERCENT. COOL SOIL TEMPERATURES WILL
AID THAT PROCESS AS WELL...AND I ANTICIPATE AREAS OF FOG TO DEVELOP
LATE THIS EVENING AND OVERNIGHT. IT REMAINS POSSIBLE SOME OF THIS
FOG COULD BECOME QUITE DENSE. LOWS TONIGHT SHOULD FALL TO WITHIN A
COUPLE DEGREES OF 50 AREA-WIDE...ABOUT 10 DEGREES ABOVE NORMAL.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 300 PM SUNDAY...INCREASINGLY DEEP 500MB LONGWAVE TROUGH
DEVELOPING ACROSS THE MIDDLE PART OF THE COUNTRY FORCES DOWNSTREAM
RIDGING ACROSS THE CAROLINAS...WITH 500MB HEIGHTS RISING ABOVE 580DM
MONDAY...AND ONLY A SLIGHT DECREASE ON TUESDAY. THIS COMBINED
WITH HIGH PRESSURE PERSISTING AT THE SURFACE CREATES WELL ABOVE
NORMAL TEMPS WITH AMPLE DECEMBER SUNSHINE THROUGH THE SHORT TERM.
SURFACE HIGH INITIALLY CENTERED NEARLY OVERHEAD WILL GRADUALLY SHIFT
EAST...BECOMING DISPLACED OFFSHORE ON TUESDAY. THIS MOVEMENT IS DUE
TO THE EASTWARD PROGRESSION OF THE UPPER TROUGH AND ASSOCIATED COLD
FRONT...WHICH WILL APPROACH FROM THE WEST AT THE END OF THE PERIOD.
WHILE HIGH SITS OVERHEAD MONDAY...WEAK RETURN FLOW WILL EXIST AT THE
SURFACE...BUT MID LEVEL FLOW WILL REMAIN W/NW. THIS IS A WARMING
/DOWNSLOPE/ TRAJECTORY...SO 850MB TEMPS AROUND 9C AND 1000-850MB
THICKNESSES OF 1370M WILL HELP DRIVE MAX TEMPS WELL INTO THE 70S
AWAY FROM THE IMMEDIATE BEACHES. AS HIGH DRIFTS OFFSHORE MONDAY
NIGHT...SOUTHERLY RETURN FLOW WILL CONTINUE...AND MINS WILL FALL
ONLY TO AROUND 50 DEGREES.
WHILE LOW LEVEL THICKNESSES REMAIN SIMILAR ON TUESDAY...INCREASED
HIGH LEVEL CLOUD COVER AHEAD OF THE COLD FRONT...GREATER LOW LEVEL
MOISTURE...AND SLIGHTLY REDUCED 500MB HEIGHTS WILL KEEP MAX TEMPS
MARGINALLY LOWER THAN ON MONDAY. STILL A VERY WARM AND DRY DAY
HOWEVER...WITH AFTN MAXIMUMS RISING INTO THE LOW 70S. PRESSURE
GRADIENT TIGHTENS AHEAD OF THE ADVANCING FRONT TUESDAY NIGHT...SO
WINDS STAY ELEVATED AND NIGHTTIME LOWS WILL FALL ONLY INTO THE LOW
50S.
ALTHOUGH FORECAST POP WILL REMAIN SILENT THROUGH THE
PERIOD...GUIDANCE IS PERSISTENT WITH SOME VERY LIGHT SHOWER ACTIVITY
EACH NIGHT. THIS IS LIKELY ASSOCIATED WITH MOIST ADVECTION BRINGING
SHOWERS ONSHORE...AND ALTHOUGH PROFILE MOISTURE IS CONFINED TO THE
LOWEST 5 KFT OR SO...SOME ISENTROPIC LIFT ALONG THE 295K SURFACE IS
EVIDENT EACH NIGHT. FEEL THE CHANCE FOR MEASURABLE PRECIP IS QUITE
LOW...SO WILL KEEP POP JUST BELOW THRESHOLD FOR NOW.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 300 PM SUNDAY...FORECAST CHALLENGE WILL COME LATER IN THE
PERIOD WHEN A BROAD CYCLONIC FLOW DEVELOPS ACROSS THE CENTRAL PART
OF THE CONUS WITH A SUBTLE SOUTHWEST FLOW ACROSS OUR CWA. AT THE
SURFACE...A FRONT WILL BE POSITIONED ACROSS THE
TENNESSEE/MISSISSIPPI VALLEY. WITH HPCS POSITION OF THE FRONT WELL
TO THE WEST...HAVE REMOVED POPS FROM THE FORECAST FOR THURSDAY
INTO FRIDAY ALTHOUGH RETURN FLOW COULD SPARK A FEW LIGHT SHOWERS
OFFSHORE. THE POSSIBILITY OF SEA FOG CANNOT BE RULED OUT WITH THIS
TYPE OF SCENARIO AS WELL. NO CHANGES TO TEMPERATURE FORECAST.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
AS OF 00Z...ANTICIPATE MVFR/IFR DUE TO FOG AND/OR LOW CIGS OVERNIGHT
INTO THE MORNING HOURS ON MONDAY. OTHERWISE EXPECT VFR.
WITH LIGHT WINDS AND PARTLY TO MOSTLY CLOUDY SKIES...A TRICKY
FORECAST IS ON TAP FOR LATE THIS EVENING AND INTO THE MORNING HOURS
AS THE POTENTIAL FOR MVFR/IFR DUE TO FOG AND/OR LOW CIGS INCREASES.
LATEST TIME HEIGHT AND FCST SOUNDING ANALYSIS DEPICTS SUFFICIENT
AVAILABLE LOW LEVEL MOISTURE ACROSS MOST OF THE AREA.
HOWEVER...INCREASING COVERAGE CLOUDS AND THEIR OPACITY ALONG WITH
STRONGER WINDS WITHIN THE BOUNDARY LAYER...PLAY A FACTOR WHETHER TO
AS THIS EVENT WILL BE MAINLY LOW STRATUS...LOW FOG...OR A MIXTURE OF
BOTH. FOR NOW...HAVE KEPT WITH CURRENT TREND OF PREVIOUS FORECAST BY
PROJECTING THE DETERIORATING WEATHER CONDITIONS DUE TO BOTH FOG AND
LOW CIGS. ATTM...EXPECT CONDITIONS TO IMPROVE TO MVFR AREA-WIDE BY
MID MORNING...PREVAILING AS VFR BY MID TO LATE MORNING. FOR THE REST
OF MONDAY EXPECT VFR WITH SCT MID LEVEL CLOUDS AND SOUTHWEST WINDS
5-8 KTS.
EXTENDED OUTLOOK...MODERATE CONFIDENCE FOR MORNING MVFR/IFR FOG
THROUGH TUESDAY WITH A PERSISTENT MOIST LOW-LEVEL ONSHORE FLOW. A
SLIGHT CHANCE OF SHOWERS LATE TUESDAY INTO WEDNESDAY ASSOCIATED WITH
A COLD FRONT. OTHERWISE VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 930 PM SUNDAY...NO ADDITIONAL SIGNIFICANT CHANGES ARE NEEDED
TO THE MARINE FORECAST THIS EVENING. SEAS AT THE FRYING PAN SHOALS
BUOY REMAIN AROUND 4 FT...WITH ABOUT HALF THAT MAKING IT TO THE
BEACHES ACCORDING TO THE WAVE GAUGE AT THE OCEAN CREST PIER ON OAK
ISLAND. PREVIOUS FULL DISCUSSION FROM 300 PM FOLLOWS...
AS HIGH PRESSURE REORIENTS ITSELF...WINDS WILL CONTINUE TO VEER FROM
E AND SE INTO THIS EVE...TO SW OVERNIGHT. WIND SPEEDS WILL BE 10 KT
OR LESS. SEAS WILL RANGE FROM 2 TO 3 FT. AN ESE 8 TO 9 SECOND SWELL
CONTINUES TO BE SAMPLED BY THE BUOYS AND NO CHANGES ARE EXPECTED
THIS PERIOD.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 300 PM SUNDAY...HIGH PRESSURE EXTENDING ACROSS THE WATERS
PERMITS ONLY LIGHT WINDS THROUGH THE PERIOD. WINDS WILL BE LIGHT AND
VARIABLE MONDAY AND MUCH OF TUESDAY...BEFORE VEERING TO THE SW AND
INCREASING TO AROUND 10 KTS TUESDAY NIGHT WELL AHEAD OF A COLD
FRONT. SEAS THEN ARE PRIMARILY SWELL DOMINATED...GENERATED FROM A
CONTINUING 3FT/8SEC SE GROUND SWELL...AND WILL BE 2-3 FT MONDAY.
SLIGHT ENHANCEMENT IN WAVE HEIGHTS EXPECTED LATE TUESDAY AS A 2-3FT
SW WIND WAVE DEVELOPS ON TOP OF THE PERSISTENT SWELL...BUT
SIGNIFICANT SEAS ARE STILL EXPECTED TO REMAIN 2-4 FT.
LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 300 PM SUNDAY...EXPECT A MODEST SOUTHWEST FLOW OF TEN KNOTS
OR SO AT THE BEGINNING OF THE PERIOD AHEAD OF A COLD FRONT TO THE
WEST. THE FRONT MOVES ACROSS THE WATERS WEDNESDAY AFTERNOON WITH A
NORTHERLY FLOW OF 10-15 KNOTS ENSUING. THE WINDS WILL REMAIN
ELEVATED RELATIVELY SPEAKING FOR MOST OF THE DAY THURSDAY IN A
10-15 KNOT RANGE WHILE VEERING TO THE NORTHEAST A BIT. FOR
FRIDAY...HIGH PRESSURE QUICKLY SLIPS OFFSHORE WITH A SOUTHEASTERLY
RETURN FLOW DEVELOPING. THE BIG STORY WITH SEAS WILL BE THE
POSSIBILITY OF SMALL CRAFT CONDITIONS THURSDAY AS THE NE FETCH
PERSISTS FOR QUITE SOME TIME. VALUES DROP BACK FRIDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JDW
NEAR TERM...TRA
SHORT TERM...JDW
LONG TERM...SHK
AVIATION...SGL
AREA FORECAST DISCUSSION
NWS RALEIGH NC
643 PM EST SUN DEC 2 2012
.SYNOPSIS...
A STEADY SOUTHWEST FLOW WILL BRING WARM AND DRY CONDITIONS ACROSS
THE AREA THROUGH TUESDAY. A COLD FRONT WILL APPROACH FROM THE WEST
TUESDAY NIGHT AND CROSS THE AREA WEDNESDAY... USHERING IN COOLER
WEATHER FOR THURSDAY.
&&
.NEAR TERM /THROUGH MONDAY NIGHT/...
AS OF 245 PM SUNDAY...
THROUGH TONIGHT: OFFSHORE-CENTERED SURFACE HIGH PRESSURE WILL
CONTINUE TO RIDGE WESTWARD THROUGH THE CAROLINAS AND SOUTHEAST
STATES TONIGHT. A MID LEVEL TROUGH AND ASSOCIATED SURFACE LOW WILL
TRACK QUICKLY EASTWARD ACROSS THE ST LAWRENCE VALLEY AND NORTHEAST
STATES TONIGHT. WHILE THE BACKDOOR FRONT TRAILING THE LOW WILL HOLD
WELL TO OUR NORTH... LIKELY DIPPING NO FURTHER SOUTH THAN THE MASON
DIXON LINE... THE PREFRONTAL SURFACE-850 MB TROUGH EXTENDING
SOUTHWEST OF THE LOW WILL SWEEP ACROSS VA AND NRN NC LATE TONIGHT. A
FEW CONVECTION-ALLOWING MODELS INCLUDING THE HRRR AND LOCAL WRF
SUGGEST THAT A THIN BAND OF LIGHT RAIN ACCOMPANYING THIS TROUGH WILL
BRUSH ACROSS SRN VA OVERNIGHT... POTENTIALLY BREACHING THE NC STATE
LINE... HOWEVER FORECAST SOUNDINGS SUGGEST THAT THE MOISTURE WILL BE
QUITE SHALLOW AND THE OPPORTUNITY FOR FORCED ASCENT DUE TO QUICK
ISENTROPIC UPGLIDE AT 295K-300K WILL BE TOO BRIEF FOR ANY MEASURABLE
PRECIP IN THE NC/VA BORDER REGION. AS SUCH... WILL LEAVE OUT ANY
POPS TONIGHT. HOWEVER... EVER-INCREASING LOW LEVEL THETA-E AND MASS
CONVERGENCE WITH THE TROUGH EVIDENT AT 925-850 MB SHOULD BRING ABOUT
QUITE A BIT OF CLOUDS TONIGHT OVER THE CENTRAL/NRN CWA... AND IN THE
SE CWA... DEVELOPMENT OF FOG AND LOW STRATUS ARE LIKELY LATE TONIGHT
GIVEN THE LIGHT WINDS... HIGH RH VALUES... AND FEWER CLOUDS. SREF
PROBABILITIES OF DENSE FOG HERE IS OVER 60 PERCENT. COMPARED TO
LAST NIGHT... EXPECT MUCH MILDER LOWS TONIGHT... 44-49.
FOR MONDAY/MONDAY NIGHT: THE TAIL OF THE WEAK 850 MB TROUGH IS
EXPECTED TO HANG BACK NEAR NRN NC THROUGH THE EARLY PART OF THE DAY
WITH HIGH THETA-E POOLING OVER THE NRN PIEDMONT. EXPECT VARIABLY TO
MOSTLY CLOUDY SKIES TO LINGER IN THIS AREA THROUGH THE NOON HOUR...
BEFORE THE TROUGH PUSHES WELL EAST OUT TO SEA FOLLOWED BY THE
RESUMPTION OF LIGHT ANTICYCLONIC 850 MB FLOW OVER NC BY LATE
AFTERNOON. IN THE SOUTHERN CWA... PARTICULARLY THE SOUTHEAST...
MORNING FOG/STRATUS WILL SLOWLY LIFT AND MIX OUT DURING THE
MORNING... ASSISTED BY DRIER AIR ALOFT... AND EXPECT MORE SUNSHINE
HERE THAN IN THE NORTHERN FORECAST AREA... AS RISING HEIGHTS ALOFT
RESULT IN A DEEP RIDGING PATTERN FROM THE SURFACE UP THROUGH THE MID
LEVELS YIELDING FEW IF ANY MID/HIGH CLOUDS. LOW LEVEL THICKNESSES
CONTINUE TO CLIMB... APPROACHING 1370 METERS BY LATE AFTERNOON...
ALTHOUGH THIS WARMING WILL BE TEMPERED BY THE LINGERING CLOUDS IN
THE NORTHERN HALF OF THE CWA. HIGHS 70-74... SHY OF RECORD HIGHS
(SEE BELOW). MOSTLY CLEAR SKIES AND A LIGHT SW FLOW MONDAY NIGHT
SHOULD LEAD TO GOOD RADIATIONAL COOLING AND ANOTHER ROUND OF PATCHY
FOG AREAWIDE. MORE ANOMALOUSLY WARM LOWS OF 45-50. -GIH
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/...
AS OF 250 PM SUNDAY...
NEAR RECORD WARMTH WILL CONTINUE TUESDAY AS A SHORTWAVE RIDGE ALOFT
SHIFTS EAST AHEAD OF A TROUGH MOVING THROUGH THE MIDWEST STATES.
LOW LEVEL THICKNESSES AREA FORECAST TO START OUT NEAR 1360M TUESDAY
MORNING...AND WITH FULL SUN TEMPS SHOULD AGAIN EACH THE LOW TO MID
70S. CIRRUS WILL BEGIN TO OVERSPREAD THE WESTERN HALF OF THE STATE
DURING THE AFTERNOON...BUT MAY BE TOO LATE FOR IMPACT ON HIGHS
AND/OR OFFSET BY A 10-12KT SOUTHWESTERLY SURFACE WIND. WILL GO WITH
69-74 NORTHWEST TO SOUTHEAST BASED ON THIS.
THE SURFACE COLD FRONT WILL APPROACH FROM THE WEST TUESDAY NIGHT
WHILE THE CORE OF THE UPPER TROUGH CROSSES THE GREAT LAKES REGION.
THE MAIN BELT OF MOISTURE ACCOMPANYING THE FRONTAL ZONE IS FORECAST
TO MOVE INTO THE WESTERN PIEDMONT PRIOR TO DAYBREAK WEDNESDAY AND
THROUGH THE PIEDMONT BY MIDDAY...CLEARING THE COASTAL PLAIN BY EARLY
EVENING. WHILE THE GFS AND ECMWF DIFFER SLIGHTLY REGARDING THE
SOUTHERN EXTENT OF STRONGEST DCVA WITH THE UPPER TROUGH...NEITHER
SHOW MUCH POTENTIAL FOR DEEP FORCING SOUTH OF VA. OF THE TWO
MODELS...THE GFS SHOWS A SHARPER TROUGH AXIS AND MORE QPF...THOUGH
MOSTLY LESS THAN A COUPLE TENTHS OF AN INCH. WHILE NOT AS WARM AS
TUESDAY...THE PREFRONTAL AIRMASS WILL STILL BE UNSEASONABLY WARM AND
MOIST WITH TEMPS IN THE 60S AND DEWPOINTS IN THE 50S. HOWEVER...VERY
LITTLE COOLING ALOFT AND WEAK DYNAMICS SHOULD LIMIT INSTABILITY AND
POTENTIAL FOR THUNDER OVER CENTRAL NC. THUS...WILL CONTINUE WITH
JUST A CHANCE OF SHOWERS DURING THE DAY.
THE AIRMASS BEHIND THE FRONT WILL NOT BE PARTICULARLY COOL...BUT
SHOULD BRING TEMPS BACK DOWN TO NEAR NORMAL THURSDAY AS HIGH
PRESSURE AND NORTHEASTERLY WINDS EXTEND SOUTH FROM EASTERN CANADA.
HIGHS THURSDAY IN THE LOW TO MID 50S...WITH MOSTLY MID 30S WEDNESDAY
AND THURSDAY NIGHTS.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 250 PM SUNDAY...
THE LARGE SCALE PATTERN BECOMES LARGELY DOMINATED BY A BROAD AND
POSITIVELY TILTED TROUGH OVER THE WESTERN US AND RIDGING ALONG THE
WESTERN ATLANTIC DURING THE EXTENDED PERIOD. THIS SHOULD PATTERN
SHOULD LEAD TO A SLOW MOVING COLD FRONT...AT LEAST INITIALLY...FROM
THE DEEP SOUTH TO THE GREAT LAKES REGION...WHILE ADDITIONAL NORTHERN
STREAM ENERGY ATTEMPTS TO MOVE SOUTH OUT OF CANADA AND INTO THE MEAN
TROUGH. MEDIUM RANGE MODELS CURRENTLY SHOW THE FRONTAL ZONE
REMAINING WEST OF THE MOUNTAINS THROUGH SATURDAY...WITH THE ECMWF
THE ONLY MODEL TO PUSH THE COLD FRONT INTO THE CAROLINAS ON SUNDAY.
FOR NOW...WILL TAKE THE MIDDLE ROAD...SHOWING ONLY SLOWLY INCREASING
POPS FROM WEST TO EAST LATE SATURDAY INTO SUNDAY. DESPITE THE
POTENTIAL FOR QUITE A BIT OF CLOUD COVER DURING THE PERIODS..TEMPS
WILL LIKELY BE AT LEAST 5-10 DEGREES ABOVE NORMAL.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
AS OF 645 PM SUNDAY...
24-HR TAF PERIOD:
INCREASED SURFACE MOISTURE...MOSTLY CLEAR SKIES AND CALM WINDS ARE
EXPECTED TO RESULT IN THE DEVELOPMENT OF LIFR/VLIFR FOG AT THE
FAY/RWI TERMINALS BETWEEN 06-12Z MONDAY...WITH VISBYS INCREASING TO
MVFR AFTER SUNRISE...BECOMING VFR AGAIN BY ~14Z (SIMILAR TO THIS
MORNING). PERIODIC MID-LEVEL CLOUD COVER AND LIGHT SOUTHERLY WINDS
MAY PREVENT THE RDU TERMINAL FROM FALLING BELOW MVFR/IFR VISBYS IN
FOG OVERNIGHT...THOUGH LIFR/VLIFR CONDITIONS CANNOT BE RULED OUT
BETWEEN 08-12Z. AT THE INT/GSO TERMINALS...THE LATEST MODEL GUIDANCE
SUGGESTS THAT MORE PERSISTENT MID-LEVEL CLOUD COVER (4-6 KFT CIGS)
AND LIGHT WINDS MAY ULTIMATELY PREVENT FOG FROM DEVELOPING...AND
HAVE TRENDED MORE OPTIMISTIC AT THOSE TERMINALS OVERNIGHT.
OTHERWISE...EXPECT VFR CONDITIONS AND LIGHT SW/WSW WINDS TO PREVAIL
THE REMAINDER OF THE TAF PERIOD.
LOOKING AHEAD:
EXPECT SUB-VFR VISBYS OR CEILINGS TO BE POSSIBLE AT ALL TERMINALS
MONDAY NIGHT IN ASSOC/W A PERSISTENT SOUTHERLY RETURN FLOW. SUB-VFR
CEILINGS AND LIGHT RAIN WILL BE POSSIBLE LATE TUESDAY NIGHT INTO
EARLY WED AFTERNOON AS A COLD FRONT PROGRESSES INTO THE CAROLINAS
FROM THE WEST. EXPECT VFR CONDITIONS TO PREVAIL IN THE WAKE OF THE
FRONT WED NIGHT THROUGH FRIDAY AS COOL AND DRY HIGH PRESSURE BUILDS
OVER THE CAROLINAS. -VINCENT
&&
.CLIMATE...
RECORD MAX TEMPS FOR DECEMBER 3RD AND DECEMBER 4TH.
DECEMBER 3RD
RDU 77 1991
GSO 72 1970
FAY 80 1991
DECEMBER 4TH
RDU 79 1978
GSO 73 1998
FAY 81 1991
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...BLS
LONG TERM...BLS
AVIATION...VINCENT
CLIMATE...WFO RAH
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
849 PM CST SUN DEC 2 2012
.DISCUSSION...
SOUTHERLY WINDS CONTINUE TO BRING MORE MOISTURE AND FAIRLY WARM
TEMPS THIS EVENING. GFK HAS HIT THE HIGHEST IT HAS SEEN ALL DAY IN
THE LAST HOUR OR SO AND THE FAR SOUTHWESTERN CWA HAS SEEN TEMPS
RISE INTO THE MID 50S. THINK THAT TEMPS COULD STAY STEADY OR
SLIGHTLY RISING FOR MUCH OF THE NIGHT AS SOUTHERLY WINDS CONTINUE
TO BRING DECENT MIXING AND 850MB TEMPS ARE NEAR 15 C IN THE
SOUTHERN CWA. AS THE SFC TROUGH AXIS/WEAK FRONTAL BOUNDARY BEGINS
TO MOVE INTO THE WESTERN CWA DURING THE 09-12Z TIME FRAME THINK WE
WILL SEE A BIT OF A COOL DOWN AS WINDS SHIFT TO THE WEST. 00Z NAM
HAS BACKED OFF A BIT ON PRECIP PRODUCED WITH THIS BOUNDARY DURING
THE EARLY MORNING HOURS...BUT WITH RADAR RETURN OVER MT
INTENSIFYING THINK THAT AT LEAST SOMETHING REACHING THE GROUND IS
POSSIBLE SO WILL KEEP THE LOW POPS WE HAVE GOING FOR THE DEVILS
LAKE BASIN DURING THE EARLY MORNING.
OTHER ISSUE IS FOG. WITH SOUTHERLY WINDS PICKING UP AND MORE
MIXING THERE HAS BEEN SOME IMPROVEMENT OVER THE CENTRAL CWA IN THE
LAST FEW HOURS. HOWEVER...THE FAR NORTHERN COUNTIES HAVE HAD
SEVERAL SITES GO DOWN TO A QUARTER MILE AT TIMES. WEB CAMS SHOW
COVERAGE IS PRETTY PATCHY SO WILL JUST INCLUDE A MENTION IN THE
GRIDS FOR THE NORTH AS WELL AS THE FAR EASTERN COUNTIES WHERE THE
HRRR AND RAP SHOW SOME LOWER VIS MOVING IN FROM THE SOUTH LATER
TONIGHT.
&&
.AVIATION...
CONDITIONS HAVE IMPROVED TO VFR FOR EVERYONE EXCEPT KBJI...WHICH
SHOULD STAY MVFR FOR MUCH OF THE NIGHT. HIGH AND MID LEVEL CLOUDS
WILL CONTINUE OVER MOST OF THE FORECAST AREA THROUGH THE REST OF
THE PERIOD WITH SOME -RA MOVING THROUGH FROM THE EARLY MORNING
HOURS IN THE WEST AND AFTERNOON IN THE EAST. BREEZY SOUTH TO
SOUTHEAST WINDS OVERNIGHT WILL SWITCH TO THE WEST BY EARLY
MORNING...AND THEN PICK UP IN THE AFTERNOON. SUSTAINED WINDS AT 15
TO 25 KTS WITH GUSTS UP TO 35 KTS ARE POSSIBLE MONDAY
AFTERNOON...PARTICULARLY OVER THE NORTHERN TAF SITES.
&&
.PREV DISCUSSION... /ISSUED 228 PM CST SUN DEC 2 2012/
SHORT TERM...
MAIN FORECAST CHALLENGES WILL BE THE BAND OF LIGHT RAIN COMING
ACROSS THE FA LATE TONIGHT/MON AND THEN GUSTY WINDS FOR MON
AFTERNOON INTO THE EVENING.
TONIGHT...HAVE HAD SOME DECENT CLEARING ACROSS THE SOUTH TODAY BUT
THE NORTH CONTINUES TO BE UNDER THE CLOUDS. VSBYS STILL LOW DUE TO
FOG IN A FEW PLACES CLOSER TO THE CANADIAN BORDER. SEEING THE WARM
TEMPS ACROSS THE SOUTHWEST THAT WERE ANTICIPATED WITH GWINNER AT
57F SO FAR. HAVE QUITE A BIT OF HIGH CLOUD COVER STREAMING IN
OVERHEAD SO EXPECT A FAIR AMOUNT OF CLOUDS TONIGHT WITH STEADY
SOUTH WINDS FOR MOST OF THE NIGHT. WILL ALSO SEE SOME VERY WARM
850MB TEMPS MOVE THRU AS WELL GENERALLY PEAKING AROUND 06Z MON
AT +14C ACROSS THE SOUTH. THIS SHOULD STRENGTHEN THE INVERSION
WHICH WILL BE GOOD AGAIN AS 925MB WIND SPEEDS ALSO CRANK UP ACROSS
THE AREA. GENERALLY THE 925MB WINDS ALSO PEAK BETWEEN 03Z AND 06Z
MON WITH SOME 45 TO 50KT VALUES. THIS SHOULD KEEP WINDS STEADY
OVERNIGHT ALONG WITH THE CLOUDS WHICH ALSO MEANS WARM TEMPS. STILL
LOOKING AT SOME PCPN DEVELOPING BEHIND THE BOUNDARY PASSAGE WHICH
SHOULD MAKE IT INTO THE FAR WESTERN FA AFTER MIDNIGHT. WITH THE
WARM TEMPS TONIGHT THIS PCPN SHOULD FALL AS RAIN.
MON-WED...THE BAND OF RAIN SHOULD QUICKLY WORK ACROSS THE FA ON
MONDAY AND CLEAR THE EAST BY MID AFTERNOON. MODELS CONTINUE TO
DIFFER ON HOW FAST TO BRING DOWN THE COLDER AIR BEHIND THE
DEPARTING LOW ON MONDAY SO WILL TRY TO MAINTAIN CONTINUITY FOR
TEMPS MONDAY. WIND SPEEDS ALSO INCREASE AGAIN WITH PRETTY GUSTY
WEST TO NORTHWEST WINDS BY AFTERNOON THRU EVENING. MAINTAINED THE
LOW CHANCES FOR LIGHT SNOW ACROSS THE NORTHEAST FA FOR MON NIGHT
INTO EARLY TUE. TUE SHOULD BE A COOLER DAY WITH SOME SLIGHT
MODERATION BY WED.
LONG TERM (WED NIGHT-SUN)...
RELATIVELY QUIET PERIOD THROUGH THE EXTENDED. SHORTWAVE TRACKING
ACROSS S CANADA WILL BRING SLIGHT SNOW CHANCES TO THE FA THURSDAY.
ASSOCIATED COLD FRONT WILL BRING COOLER TEMPERATURES TO THE REGION.
HIGH PRESSURE WILL BUILD IN FOR REMAINDER OF PERIOD WITH OVERALL
SEASONAL TEMPERATURES.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
JR
AREA FORECAST DISCUSSION...CORRECTED
NWS PORTLAND OR
924 PM PST FRI NOV 30 2012
.SYNOPSIS...A BROAD UPPER LOW OVER THE NE PACIFIC WILL CONTINUE
UNSETTLED WEATHER INTO NEXT WEEK. THE NEXT FRONT WILL MOVE THROUGH
THE AREA TONIGHT AND SATURDAY MORNING. SNOW LEVELS WILL LOWER TO PASS
LEVEL WITH THIS SYSTEM. ANOTHER FRONT WILL BRING MORE SUBSTANTIAL
CASCADE SNOW SATURDAY NIGHT AND SUNDAY.A STRONG UPPER JET WILL
CONTINUE SHOWERS THROUGH SUNDAY NIGHT. THERE WILL BE A BRIEF BREAK IN
PRECIPITATION MONDAY MORNING BEFORE ANOTHER MOIST FRONT WILL MOVE
THROUGH MONDAY NIGHT AND TUESDAY.
&&
.SHORT TERM...A VIGOROUS VORT MAX AND SHORTWAVE TROUGH MOVING INTO
WEST COAST ARE RESPONSIBLE FOR RAIN SHOWERS LIFTING NORTHEASTWARD
ACROSS THE REGION THIS EVENING. SO FAR RAIN IS PRIMARILY CONFINED
ACROSS THE NORTHWESTERN HALF OF THE CWA...BUT EXPECT THIS BROAD BAND
OF PRECIPITATION TO SHIFT SOUTHEASTWARD AS THE NIGHT PROGRESSES. SNOW
LEVELS NEAR 5000-5500 FT THIS EVENING SHOULD DROP TO NEAR 4000 FT BY
MORNING WITH 5 TO 8 INCHES OF NEW SNOW EXPECTED
ISOLATED THUNDERSTORMS HAVE BEEN DEVELOPING ACROSS OUR WATERS WITH A
FEW BEGINNING TO PUSH ASHORE NEAR BAY CITY AND TILLAMOOK. AN EVEN
MORE NOTEWORTHY CLUSTER OF THUNDERSTORMS HAS ERUPTED WEST OF COOS
BAY. IT APPEARS THIS CLUSTER WILL LIFT EAST-NORTHEASTWARD INTO THE
SOUTH CENTRAL OREGON COAST. AS A RESULT OF ALL THIS
ACTIVITY...THUNDER WAS ADDED TO THE OVERNIGHT FORECAST FOR THE COAST
RANGE AND THE SOUTH WILLAMETTE VALLEY.
NUMEROUS SITES HOVERED IN THE 45 TO 55 MPH RANGE FOR WIND GUSTS THIS
EVENING. THE RUC SEEMED TO INDICATE THE HIGH WINDS WERE ABOUT TO
SUBSIDE AND THAT WE WERE GOING TO ESCAPE UNSCATHED...JUST BEFORE
SEVERAL SITES REACHED HIGH WIND CRITERIA ALONG THE COAST. THESE
INCLUDED LINCOLN CITY...THE YAQUINA BRIDGE AND GARIBALDI. THIS
COINCIDED NICELY WITH AN INFLUX OF 65 TO 75KT INBOUND RETURNS AT
APPROXIMATELY 7500 FT VIA THE KRTX RADAR. WINDS APPEAR TO HAVE
TEMPORARILY BACKED OFF ALOFT VIA RADAR...BUT AN ADDITIONAL SPIKE IN
WINDS IN ANOTHER HOUR OR TWO ASSOCIATED WITH THE NEXT BAND OF
CONVECTION SEEMS PLAUSIBLE.
NO FLOODING IS ANTICIPATED DUE TO THE RAINFALL EXPECTED OVERNIGHT.
WITH THAT SAID...THE GRAYS RIVER AT ROSBURG IS BEGINNING TO GO UP
SOMEWHAT SHARPLY SO THIS WILL BE MONITORED CLOSELY OVERNIGHT.
/NEUMAN
PREVIOUS DISCUSSION BELOW...A LARGE COMPLEX UPPER LOW OVER THE NE
PACIFIC WILL CONTINUE TO SEND SYSTEMS ACROSS THE REGION INTO NEXT
WEEK. CONVECTIVE SHOWERS WILL CONTINUE GUSTY AND SHOWERY WEATHER LATE
THIS AFTERNOON...ESPECIALLY FOR THE COAST AND COAST RANGE. THE
SHOWERS WILL RAMP UP THIS EVENING AS THE NEXT SYSTEM...CURRENTLY NEAR
43N 134W APPROACHES. THIS SYSTEM WILL BRING ANOTHER ROUND OF GUSTY
WINDS AND HEAVY RAIN TONIGHT.
COOLER AIR WILL MOVE IN BEHIND THE FRONT WITH 700 MB MODELED
TEMPERATURES COOLING TO -9C BETWEEN 4 AND 10 PST SATURDAY MORNING.
SNOW LEVELS WILL LOWER TO NEAR OR JUST BELOW PASS LEVEL EARLY
SATURDAY MORNING. ALTHOUGH THE MAIN RAIN BAND WILL HAVE PUSHED
THROUGH BY THEN...A 120KT PLUS JET WILL CONTINUE SHOWERS THROUGH
SATURDAY AND EXPECT SOME DECENT SNOW ACCUMULATIONS AT THE PASSES
SATURDAY MORNING. THE SOUTH WASHINGTON CASCADES WILL HAVE THE HIGHEST
SNOW AMOUNTS AND HAVE ISSUED A LOW-END WINTER WEATHER ADVISORY FOR
TONIGHT THROUGH SATURDAY.
SHOWERS WILL LIGHTEN UP BRIEFLY SATURDAY AFTERNOON BEFORE THE NEXT.
SYSTEM...CURRENTLY NEAR 43N 148W CONTINUES THE UNSETTLED WEATHER.
THERE IS MORE MOISTURE WITH THIS SYSTEM THEN THE FEW PREVIOUS ONES
WITH MODELED TROPICAL PRECIPITABLE WATER VALUES NEAR AN INCH...AND
EXPECT SLIGHTLY MORE PRECIPITATION WITH THE FRONT EARLY SUNDAY
MORNING.THERE IS ALSO A STRONGER JET (150 +KT) BACKING UP THIS
SYSTEM THAT WILL RESULT IN MORE SUBSTANTIAL POST-FRONTAL SHOWERS
SUNDAY AFTERNOON AND NIGHT.
THE LOW HAS A FAVORABLE STORM TRACK FOR PRODUCING STRONG INLAND
WINDS...BUT THE MODELS HAVE BEEN BACKING OFF ON THE STRENGTH OF THE
LOW AND CURRENTLY THINK THE WINDS WILL REMAIN BELOW WARNING...BUT
GUSTY FOR SURE.
SNOW LEVELS WILL NOT RECOVER MUCH BETWEEN THE SATURDAY AND SUNDAY
SYSTEMS AND EXPECT MORE ABUNDANT SNOW IN THE CASCADES. THERE WILL BE
AT LEAST SOLID ADVISORY SNOW FROM SATURDAY NIGHT THROUGH SUNDAY
AFTERNOON...BUT WARNING AMOUNTS ARE NOT OUT OF THE QUESTION AND HAVE
ISSUED A WINTER STORM WATCH FOR ALL OF THE CASCADES.
SHOWERS WILL LIGHTEN UP SOME MONDAY MORNING...BUT WILL NOT END ALL
TOGETHER AS ANOTHER LOW WILL DROP DOWN INTO THE NE PACIFIC AND
BRING ANOTHER POTENTIALLY MOIST STORM MONDAY AFTERNOON AND EVENING.
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY...MODEL GUIDANCE IS SHOWING
REASONABLY GOOD AGREEMENT THROUGH THE FIRST HALF OF NEXT WEEK. THE
LATEST MEDIUM RANGE MODEL RUNS HAVE SPED UP THE PROGRESSION OF THE
NEXT FRONTAL SYSTEM. NOW EXPECT PRECIPITATION TO BEGIN SPREADING INTO
THE COAST MONDAY NIGHT...THEN PROGRESS INLAND DURING THE DAY TUE. IT
APPEARS THAT THIS FRONT WILL MAINTAIN A CONNECTION TO TROPICAL
MOISTURE. MODEL PWAT VALUES OF 1 TO 1.25 INCHES COMBINED WITH A
STRONG LOW LEVEL JET ARE EXPECTED TO BRING FAIRLY IMPRESSIVE MOISTURE
TRANSPORT INTO THE REGION. A MODERATE-TO-HEAVY RAINFALL EVENT IS
LOOKING LIKELY AT THIS POINT...WITH THE POTENTIAL FOR SOME GUSTY
COASTAL WINDS. HOWEVER...AT THIS POINT THE FOCUS OF THE HEAVIEST RAIN
APPEARS TO REMAIN TO OUR SOUTH...ALONG THE CA/OR BORDER...SO WE MAY
AVOID SIGNIFICANT HYDROLOGIC ISSUES. THE HEAVY RAINFALL SHOULD TAPER
OFF LATER TUE AS THE FRONT PUSHES EAST...BUT EXPECT SHOWER ACTIVITY
TO CONTINUE OVERNIGHT TUE AND WED AS THE PARENT UPPER TROUGH PUSHES
THROUGH THE PAC NW. WE SHOULD TREND DRIER OVER THE SECOND HALF OF THE
WEEK AS WEAK UPPER LEVEL RIDGING BUILDS IN BEHIND THE DEPARTING
TROUGH. PYLE
&&
.AVIATION...COOL MOIST AND UNSTABLE AIR MASS REMAINS OVER THE
REGION. W TO SW FLOW ALOFT CONTINUES WITH EMBEDDED DISTURBANCES
THESE DISTURBANCES WILL ENHANCE THE SHOWER BANDS THIS AFTERNOON
FOR THE COAST...AND FOR MOST AREAS AGAIN LATER THIS EVENING.
EXPECT MVFR CHANCES WILL BE MOST PERSISTENT ALONG THE COAST
THROUGH THE PERIOD...WITH THE BEST MVFR CHANCES INLAND OVERNIGHT.
BEST THREAT FOR TSTORMS REMAINS FROM COAST RANGE WESTWARD...WITH A
SMALL CHANCE OF IMPACTING THE COASTAL TERMINALS MAINLY DURING THE
LATE EVENING AND OVERNIGHT HOURS AS THE NEXT STRONGER FRONT MOVES
IN. TSTORM THREAT SHIFTS NORTH OF THE COLUMBIA RIVER SUNDAY
MORNING.
KPDX AND APPROACHES...VFR CONDITIONS WITH INTERMITTENT SHOWERS
THROUGH THIS EVENING...WITH BRIEF MVFR UNDER THE SHOWERS. BETTER
CHANCE FOR MVFR IN RAIN OVERNIGHT. GUSTY S TO SE WINDS WILL
CONTINUE THROUGH THE PERIOD...THOUGH MAINLY GUSTS TO 25 KT OR
LESS...POSSIBLY HIGHER AT TIMES OVERNIGHT. VFR RETURNS SATURDAY AS
FRONT CLEARS THE TERMINAL BY DAYBREAK. KMD/BROWN
&&
.MARINE...STRONG LOW PRESSURE OFFSHORE OF THE TIP OF VANCOUVER
ISLAND WILL SLOWLY WEAKEN THROUGH THE WEEKEND...BUT A FAIRLY
STRONG PRESSURE GRADIENT WILL REMAIN DRAPED OVER THE WATERS. THIS
COMBINED WITH SHOWER ACTIVITY FROM A SERIES OF FRONTS MOVING
THROUGH THE WATERS TONIGHT AND AGAIN SATURDAY WILL CREATE GALE
FORCE GUSTS THROUGH THE DAY ON SATURDAY. GALES MAY WEAKEN AT
TIMES.
SEAS WILL REMAIN IN THE 16 TO 18 FT RANGE THROUGH SAT...THOUGH
MAY GET UP TO 19-20 FT TONIGHT WITH A FRONTAL PASSAGE AND
ESPECIALLY ACROSS THE CENTRAL OREGON WATERS. SEAS GRADUALLY
SUBSIDING ON SUN INTO MON BACK INTO THE LOWER TEENS...BUT
CONFIDENCE IS LOW ON SEAS DROPPING BACK BELOW 10 FT FOR ANY
EXTENDED PERIOD UNTIL THE LATTER HALF OF NEXT WEEK WHEN HIGH
PRESSURE ATTEMPTS TO BUILD IN. KMD/BROWN
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...WINTER STORM WATCH FROM LATE SATURDAY NIGHT THROUGH LATE SUNDAY
NIGHT FOR CASCADES IN LANE COUNTY-NORTHERN OREGON CASCADES.
HIGH WIND WARNING UNTIL 1 AM PST SATURDAY FOR CENTRAL OREGON
COAST-NORTH OREGON COAST.
WA...WINTER WEATHER ADVISORY FROM 1 AM TO 4 PM PST SATURDAY FOR SOUTH
WASHINGTON CASCADES.
WINTER STORM WATCH FROM LATE SATURDAY NIGHT THROUGH LATE SUNDAY
NIGHT FOR SOUTH WASHINGTON CASCADES.
PZ...GALE WARNING UNTIL 10 PM PST SATURDAY FOR COASTAL WATERS FROM
CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 10 PM
PST SATURDAY.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...HTTP://WEATHER.GOV/PORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1051 PM EST SUN DEC 2 2012
.SYNOPSIS...
A WEAKENING COLD FRONT WILL WASH OUT AS IT ENTERS NORTHERN PENNSYLVANIA
TONIGHT. HIGH PRESSURE WILL BUILD ALONG THE EAST COAST EARLY THIS
WEEK. A COLD FRONT WILL PUSH THROUGH THE REGION TUESDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
WATER VAPOR LOOP SHOWS POTENT SHORTWAVE MOVING EASTWARD ACROSS SOUTHERN
QUEBEC AT 03Z. WANING LG SCALE FORCING BEHIND THIS FEATURE HAS
CAUSED SHOWERS TO DIMINISH ACROSS CENTRAL PA AND LATEST RAP DATA
AND RADAR TRENDS SUGGEST ANY REMAINING -SHRA OR DRIZZLE AFTER
MIDNIGHT WILL BE CONFINED MAINLY TO THE UPSLOPE AREAS ALONG THE
LAUREL HIGHLANDS.
SFC COLD FRONT...APPROACHING THE NORTHERN LK ERIE SHORE AT
03Z...WILL SAG INTO THE N MTNS LATE TONIGHT. OVERCAST SKIES AND A
SW BREEZE WILL KEEP IT VERY MILD OVERNIGHT WITH LOWS MOSTLY IN THE
M/U40S. PLENTY OF LOW LVL MOISTURE AND LGT WINDS WILL RESULT IN
AREAS OF FOG. SOME OF THE FOG COULD BECOME DENSE...ESP OVR THE W
MTNS...WHERE A LGT SW WIND ASCENDS THE HIGH TERRAIN.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
RIDGING AT THE SFC AND ALOFT SHOULD SUPPLY CENTRAL PA WITH DRY WX
ON MONDAY. HOWEVER...PLENTY OF LOW LVL MOISTURE WILL REMAIN
TRAPPED BENEATH SUBSIDENCE INVERSION...RESULTING IN A GOOD DEAL OF
CLOUD COVER...ESP ACROSS THE W MTNS WHERE A LIGHT W WIND ASCENDS
THE HIGH TERRAIN.
DESPITE THE CLOUD COVER...CENTRAL PA WILL BE ON THE EDGE OF AN
UNSEASONABLY WARM AIR MASS CENTERED OVR THE MIDWEST/OHIO VALL.
LATEST GUIDANCE CONTINUES TO SUGGEST TEMPS WILL REACH CLOSE TO
60F OVER MUCH OF CENTRAL PA MON AFTN.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
EXTENSIVE ZONAL UPPER FLOW ACROSS MUCH OF THE LOWER 48 IS
FORECAST TO CONTINUE THROUGH MUCH OF THE LONG TERM PERIOD. THIS
FLOW PATTERN WILL KEEP LARGE SCALE COLD WEATHER AT BAY...BUT SOME
VISITS FROM WINTRY WEATHER ARE NOT OUT OF THE QUESTION. SEVERAL
PIECES OF SHORTWAVE ENERGY MOVING THROUGH THE FLOW WILL LEAD TO
CHANCES FOR PCPN DURING THE WEEK AHEAD.
TUESDAY/S HIGHS WILL BE 18-20F ABOVE NORMAL...AND PERHAPS AS MUCH
AS 25F ABOVE NORMAL ACROSS LAUREL HIGHLANDS AND ADJACENT SOUTH-
CENTRAL VALLEYS AHEAD OF THE NEXT APPROACHING COLD FRONT.
THE POTENT SHORTWAVE CRASHING ONTO THE NW COAST TODAY /SUNDAY/ WILL
MOVE QUICKLY EAST ACROSS SOUTHERN CANADA AND AMPLIFY AS IT SLIDES
THROUGH ONTARIO PROVINCE DURING THE MIDWEEK PERIOD. THE ASSOCIATED
COLD FRONT WILL BRING A SEVERAL HOUR PERIOD OF RAIN SHOWERS TO THE
REGION LATE TUESDAY/TUESDAY NIGHT...WITH MOST MODEL GUIDANCE AND
ENSEMBLES INDICATING A MEAN QPF OF ABOUT 2-3 TENTHS.
THE SURGE OF MUCH COOLER AIR IN THE WAKE OF THE FRONT WILL SUPPORT
SCATTERED SNOW SHOWERS ACROSS MAINLY THE MTNS OF NWRN PENN LATE
TUESDAY NIGHT AND WEDNESDAY...WITH MINOR ACCUMULATIONS OF A COATING
TO AND INCH OR TWO POSSIBLE /NEAR AND TO THE WEST OF KBFD/.
ENSEMBLE MOS TEMPS STAY A FEW...TO SEVERAL DEG F ABOVE NORMAL FOR
THURSDAY AND FRIDAY AS UPPER HEIGHTS REBOUND ONLY SLIGHTLY...AND A
BUBBLE OF HIGH PRESSURE WITH CP AIR SLIDES SE FROM THE PRAIRIE
PROVINCES OF SCENT CANADA AND REACHES THE NE U.S. COAST THURSDAY
NIGHT.
UNCERTAINTY CLIMBS SIGNIFICANTLY FOR NEXT WEEKEND AS THE NEXT COLD
FRONTAL BOUNDARY SLOWS AND PERHAPS TEMPORARILY STALLS OUT FROM THE
OHIO VALLEY THROUGH THE MID ATLANTIC REGION. LARGE DIVERGENCE ARISES
IN THE QPF PATTERN/FRONTAL LOCATION BETWEEN 00Z/06Z GFS AND
EC...ALONG WITH A LARGE SPREAD IN GEFS /PLUME/ QPF AND SFC-925 MB
TEMPS.
RAIN CHANCES INCREASE BEGINNING LATE FRIDAY NIGHT THROUGH NEXT
WEEKEND...AND COULD POSSIBLY BE MIXED WITH SNOW ACROSS THE NW HALF
OF THE STATE.
&&
.AVIATION /04Z MONDAY THROUGH FRIDAY/...
21Z/00Z TAF PACKAGES.
BEEN UPDATING TAFS.
A FEW MORE SHOWERS...THEN MAINLY CLOUDY OVERNIGHT. LOOKING
AT MAINLY IFR AND MVFR CONDITIONS OVERNIGHT INTO MONDAY MORNING.
SOME IMPROVEMENT BY AFT...BUT HIGH HEIGHTS AND LOW SUN ANGLE
WILL LIKELY RESULT IN SC BEING TRAPPED.
WARM ADVECTION SETS LATE MONDAY INTO EARLY TUE...BEFORE A COLD
FRONT MOVES IN LATE TUE. MORE SHOWERS WITH THE COLD FRONT.
OUTLOOK...
TUE...A STRONG COLD FRONT WILL ENTER THE REGION LATE IN THE DAY
AND PASS OVERNIGHT. VFR TO MVFR WITH RAIN SHOWERS LATE. ISOLD
TSTMS PSBL. WIND-SHIFT BY WED AM.
WED...MVFR WEST WITH SNOW/RAIN SHOWERS.
THU/FRI...NO SIG WX.
&&
.EQUIPMENT...
IPT OBSERVATION NOT BEING TRANSMITTED OR RECEIVED INTO OUR SYSTEMS.
FAA IS AWARE AND WORKING THE ISSUE. WE STILL HAVE DIAL-UP CAPABILITY.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD/LA CORTE
NEAR TERM...FITZGERALD/LA CORTE
SHORT TERM...FITZGERALD/LA CORTE
LONG TERM...LAMBERT/GARTNER
AVIATION...LA CORTE/MARTIN
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
824 PM EST SUN DEC 2 2012
.SYNOPSIS...
A WEAKENING COLD FRONT WILL WASH OUT AS IT ENTERS NORTHERN PENNSYLVANIA
TONIGHT. HIGH PRESSURE WILL BUILD ALONG THE EAST COAST EARLY THIS
WEEK. A COLD FRONT WILL PUSH THROUGH THE REGION TUESDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
WATER VAPOR LOOP SHOWS POTENT SHORTWAVE MOVING EASTWARD INTO
SOUTHERN QUEBEC AT 01Z. WANING LG SCALE FORCING BEHIND THIS
FEATURE IS CAUSING SHOWERS TO DIMINISH ACROSS CENTRAL PA AND
LATEST RAP DATA AND RADAR TRENDS SUGGEST MOST OF THE REMAINING
SHOWERS WILL EXIT THE REGION BY 03Z-04Z.
RESIDUAL LOW LVL MOISTURE ASCENDING THE ALLEGHENIES WILL LIKELY
CAUSE OCNL -DZ TO PERSIST OVR THE W MTNS LATE TONIGHT. SFC COLD
FRONT...APPROACHING THE NORTHERN LK ERIE SHORE AT 01Z...WILL SAG
INTO THE N MTNS LATE TONIGHT. DRIER AIR BEHIND THIS BOUNDARY WILL
LIKELY CAUSE ANY REMAINING -DZ TO BE CONFINED TO THE LAUREL
HIGHLANDS BY EARLY AM MONDAY.
IT WILL REMAIN MILD OVERNIGHT WITH LOWS IN THE 40S...AS THE COLD FRONT
WASHES OUT OVR NORTHERN PA. PLENTY OF LOW LVL MOISTURE AND LGT
WINDS WILL RESULT IN AREAS OF FOG. SOME OF THE FOG COULD BECOME
DENSE...ESP OVR THE W MTNS...WHERE A LGT WEST WIND ASCENDS THE
HIGH TERRAIN.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
RIDGING AT THE SFC AND ALOFT SHOULD SUPPLY CENTRAL PA WITH DRY WX
ON MONDAY. HOWEVER...PLENTY OF LOW LVL MOISTURE WILL REMAIN
TRAPPED BENEATH SUBSIDENCE INVERSION...RESULTING IN A GOOD DEAL OF
CLOUD COVER...ESP ACROSS THE W MTNS WHERE A LIGHT W WIND ASCENDS
THE HIGH TERRAIN.
DESPITE THE CLOUD COVER...CENTRAL PA WILL BE ON THE EDGE OF AN
UNSEASONABLY WARM AIR MASS CENTERED OVR THE MIDWEST/OHIO VALL.
LATEST GUIDANCE CONTINUES TO SUGGEST TEMPS WILL REACH CLOSE TO
60F OVER MUCH OF CENTRAL PA MON AFTN.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
EXTENSIVE ZONAL UPPER FLOW ACROSS MUCH OF THE LOWER 48 IS
FORECAST TO CONTINUE THROUGH MUCH OF THE LONG TERM PERIOD. THIS
FLOW PATTERN WILL KEEP LARGE SCALE COLD WEATHER AT BAY...BUT SOME
VISITS FROM WINTRY WEATHER ARE NOT OUT OF THE QUESTION. SEVERAL
PIECES OF SHORTWAVE ENERGY MOVING THROUGH THE FLOW WILL LEAD TO
CHANCES FOR PCPN DURING THE WEEK AHEAD.
TUESDAY/S HIGHS WILL BE 18-20F ABOVE NORMAL...AND PERHAPS AS MUCH
AS 25F ABOVE NORMAL ACROSS LAUREL HIGHLANDS AND ADJACENT SOUTH-
CENTRAL VALLEYS AHEAD OF THE NEXT APPROACHING COLD FRONT.
THE POTENT SHORTWAVE CRASHING ONTO THE NW COAST TODAY /SUNDAY/ WILL
MOVE QUICKLY EAST ACROSS SOUTHERN CANADA AND AMPLIFY AS IT SLIDES
THROUGH ONTARIO PROVINCE DURING THE MIDWEEK PERIOD. THE ASSOCIATED
COLD FRONT WILL BRING A SEVERAL HOUR PERIOD OF RAIN SHOWERS TO THE
REGION LATE TUESDAY/TUESDAY NIGHT...WITH MOST MODEL GUIDANCE AND
ENSEMBLES INDICATING A MEAN QPF OF ABOUT 2-3 TENTHS.
THE SURGE OF MUCH COOLER AIR IN THE WAKE OF THE FRONT WILL SUPPORT
SCATTERED SNOW SHOWERS ACROSS MAINLY THE MTNS OF NWRN PENN LATE
TUESDAY NIGHT AND WEDNESDAY...WITH MINOR ACCUMULATIONS OF A COATING
TO AND INCH OR TWO POSSIBLE /NEAR AND TO THE WEST OF KBFD/.
ENSEMBLE MOS TEMPS STAY A FEW...TO SEVERAL DEG F ABOVE NORMAL FOR
THURSDAY AND FRIDAY AS UPPER HEIGHTS REBOUND ONLY SLIGHTLY...AND A
BUBBLE OF HIGH PRESSURE WITH CP AIR SLIDES SE FROM THE PRAIRIE
PROVINCES OF SCENT CANADA AND REACHES THE NE U.S. COAST THURSDAY
NIGHT.
UNCERTAINTY CLIMBS SIGNIFICANTLY FOR NEXT WEEKEND AS THE NEXT COLD
FRONTAL BOUNDARY SLOWS AND PERHAPS TEMPORARILY STALLS OUT FROM THE
OHIO VALLEY THROUGH THE MID ATLANTIC REGION. LARGE DIVERGENCE ARISES
IN THE QPF PATTERN/FRONTAL LOCATION BETWEEN 00Z/06Z GFS AND
EC...ALONG WITH A LARGE SPREAD IN GEFS /PLUME/ QPF AND SFC-925 MB
TEMPS.
RAIN CHANCES INCREASE BEGINNING LATE FRIDAY NIGHT THROUGH NEXT
WEEKEND...AND COULD POSSIBLY BE MIXED WITH SNOW ACROSS THE NW HALF
OF THE STATE.
&&
.AVIATION /01Z MONDAY THROUGH FRIDAY/...
21Z/00Z TAF PACKAGES.
BEEN UPDATING TAFS.
A FEW MORE SHOWERS...THEN MAINLY CLOUDY OVERNIGHT. LOOKING
AT MAINLY IFR AND MVFR CONDITIONS OVERNIGHT INTO MONDAY MORNING.
SOME IMPROVEMENT BY AFT...BUT HIGH HEIGHTS AND LOW SUN ANGLE
WILL LIKELY RESULT IN SC BEING TRAPPED.
WARM ADVECTION SETS LATE MONDAY INTO EARLY TUE...BEFORE A COLD
FRONT MOVES IN LATE TUE. MORE SHOWERS WITH THE COLD FRONT.
OUTLOOK...
TUE...A STRONG COLD FRONT WILL ENTER THE REGION LATE IN THE DAY
AND PASS OVERNIGHT. VFR TO MVFR WITH RAIN SHOWERS LATE. ISOLD
TSTMS PSBL. WIND-SHIFT BY WED AM.
WED...MVFR WEST WITH SNOW/RAIN SHOWERS.
THU/FRI...NO SIG WX.
&&
.EQUIPMENT...
IPT OBSERVATION NOT BEING TRANSMITTED OR RECEIVED INTO OUR SYSTEMS.
FAA IS AWARE AND WORKING THE ISSUE. WE STILL HAVE DIAL-UP CAPABILITY.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD/LA CORTE
NEAR TERM...FITZGERALD/LA CORTE
SHORT TERM...FITZGERALD/LA CORTE
LONG TERM...LAMBERT/GARTNER
AVIATION...LA CORTE/MARTIN
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1030 AM EST SAT DEC 1 2012
.SYNOPSIS...
ARCTIC HIGH PRESSURE OVER MAINE WILL RETREAT NORTHEAST THROUGH THE
CANADIAN MARITIMES INTO THE NORTHERN ATLANTIC BY SUNDAY. MEANWHILE A
WARM FRONT NEAR THE PENNSYLVANIA NEW YORK BORDER WILL LIFT SLOWLY
NORTH INTO NEW ENGLAND...AS A MILD SOUTHWEST FLOW OVERSPREADS THE
AREA AHEAD OF A COLD FRONT MOVING INTO THE GREAT LAKES. THIS
FRONTAL SYSTEM WILL BRING A FEW SHOWERS TO THE AREA LATER
SUNDAY...WITH A BETTER CHANCE FOR RAIN COMING ON TUESDAY WITH A
STRONGER COLD FRONT. TEMPERATURES WILL BE WELL ABOVE NORMAL EARLY
NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
9AM MORNING UPDATE...
LOW CLOUDS COVER ABOUT THE EASTERN 1/2 OF MY FCST AREA...WITH THE
WESTWARD MOVEMENT SEEMING TO HAVE SLOWED OR HALTED AS OF MID
MORNING. THE LATEST RAP FCST SOUNDINGS AND NAM MOS GUIDANCE INDICATE
THE STRATUS WILL BE VERY DIFFICULT TO DISLODGE OVR THE MID-LWR
SUSQ...WITH THE LLVL MSTR REMAINING TRAPPED UNDER STRONG INVERSION.
MADE ONLY SLIGHT TWEAKS TO THE SHORT TERM UPDATE.
PREVIOUS DISCUSSION...
THE EASTERLY MARITIME/UPSLOPE FLOW WILL BE TOPPED BY MODERATELY
STRONG MID-LVL WARM ADVECTION FROM THE SOUTHWEST...WHICH WILL
MAINTAIN LOW CLOUDS ACROSS CENTRAL AND ERN PENN. THE LOW CLOUDS
WILL EFFECTIVELY HOLD TEMPS IN THE UPPER 30S/LOW 40S OVR THE ERN
1/3 OF THE CWA. MEANWHILE...PARTLY TO MOSTLY SUNNY CONDS OVR THE
SWRN 1/2 OF THE AREA WILL ALLOW TEMPS TO CLIMB INTO THE UPPER 40S.
LOW LEVEL WINDS WILL TURN MORE SOUTHERLY TNT...WITH LOW CLOUDS
REMAINING OVR THE NRN AND ERN PARTS OF THE CWA. CLOUDS AND
INCREASING SLY FLOW AHEAD OF WEAK PAC FNTL SYS CROSSING THE GRT
LKS WILL BRING RELATIVELY MILD OVERNIGHT TEMPS IN 35-40F
RANGE...OR 5-10 DEGREES ABV NORMAL.
&&
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
SFC WARM FRONT WILL LIFT WELL TO THE NORTHEAST OF THE REGION EARLY
SUNDAY. A WEAK COLD FRONT WILL RACE EAST FROM THE OHIO VALLEY AND
SPREAD LOWERING AND THICKENING CLOUDS ACROSS THE NORTHWEST HALF F
THE CWA DURING THE MORNING FOLLOWED BY A SEVERAL TO 10 HOUR PERIOD
OF MAINLY LIGHT SHOWERS SUNDAY AFTERNOON AND NIGHT.
ACROSS THE APPROXIMATE SE HALF OF THE STATE....BKN-OVC CLOUD WILL BE
MAINLY IN THE FORM OF ALTO CU/ALTO STRATUS WITH SOME LIGHTER SHOWERS
LATE SUNDAY INTO EARLY MONDAY.
00Z OPERATIONAL MODEL/ENSEMBLE BLEND INDICATES THAT TOTAL RAINFALL
WITH THIS FRONT AND ASSOCIATED...FLAT UPPER SHORT WAVE WILL RANGE
FROM 3-4 TENTHS ACROSS THE NW MTNS...TO ONLY AROUND 0.10 OVER THE
LOWER SUSQ VALLEY.
SHOWERS WILL DIMINISH VERY EARLY MONDAY AS A RIDGE OF HIGH PRESSURE
AT THE SFC AND ALOFT BUILDS IN FROM THE WEST.
HIGH TEMPS SUNDAY WILL BE 10 TO 20 DEGREES ABOVE NORMAL SUNDAY
AFTERNOON...WITH THE GREATEST DEPARTURES OCCURRING ACROSS THE LAUREL
HIGHLANDS. HIGHS SUNDAY WILL RANGE FROM NEAR 50 ACROSS THE MTNS
NORTHEAST OF KIPT...TO THE LOWER 60S IN THE SOUTHWEST PART OF THE
CWA.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
BEHIND THE QUICK MOVING UPPER WAVE AND SFC FRONT...500 MB HEIGHTS
WILL RISE BY 30-40M...TO NEARLY PLUS 2 SIGMA MONDAY. THIS /COMBINED
WITH A NORTH/SOUTH SFC RIDGE BECOMING LOCATED RIGHT OVER THE REGION
MONDAY AFTERNOON/ WILL BRING PARTIAL CLEARING AT LEAST ACROSS THE
CENTRAL AND ERN VALLEYS...ALONG WITH CONTINUED UNSEASONABLY MILD
TEMPS IN THE MID 50S NORTH...TO AROUND 60F ACROSS THE SOUTH.
TUESDAY WILL CONTINUE THIS STRING OF WELL ABOVE NORMAL TEMPS WITH
SOME PERIODS OF PARTIAL SUNSHINE...FOLLOWED BY AN INCREASE IN LATE
DAY CLOUDS FROM THE WEST AHEAD OF THE NEXT COLD FRONT. A
GUSTY...DOWNSLOPING SOUTHWESTERLY WIND IN THE AFTERNOON WILL BLOW AT
15-20 KTS.
HIGHS TUESDAY SHOULD BE SIMILAR TO...IF NOT A FEW DEG F WARMER THAN
MONDAY/S QUITE BALMY TEMPS FOR EARLY DECEMBER.
A RATHER VIGOROUS MID/UPPER LEVEL TROUGH AND SFC COLD FRONT WILL
APPROACH FROM THE MIDWEST DURING THE DAY TUESDAY...AND COMBINE WITH
THE RIGHT ENTRANCE REGION OF A SWRLY 110 KT JET MAX TO BRING A
PERIOD OF SHOWERS...FOCUSED PRIMARILY IN THE LATE TUESDAY/TUESDAY
NIGHT TIMEFRAME.
OPERATIONAL MODEL/ENSEMBLE CONSENSUS QPF FORECAST IS BETWEEN 1-3
TENTHS OF AN INCH ACROSS THE SE HALF OF THE CWA THROUGH EARLY
WED...WITH AS MUCH AS 0.50 INCH OF RAINFALL ACROSS THE NW MTNS.
A QUICK SURGE OF COLDER/ALBEIT GREATLY MODIFIED CP AIR WILL FOLLOW
FOR WEDNESDAY AND WEDNESDAY NIGHT WITH SCATTERED SNOW SHOWERS AND
PERHAPS SOME LIGHT ACCUMS ACROSS THE NW MTNS AS A SHARP MID/UPPER
LEVEL THERMAL TROUGH CROSSES THE REGION WITH THE SUBSIDENCE
INVERSION BASE RISING TO AROUND 5 KFT AGL WITH A DEEP AND
WELL-ALIGNED NWRLY FLOW TRANSPORTING LIMITED MOISTURE INLAND FROM
THE GLAKES.
FOR THE CENTRAL RIDGE AND VALLEY REGION...SPRINKLES AND FLURRIES OR
PERHAPS A FEW BRIEF RAIN/SNOW SHOWERS WILL SPILL SE OFF THE
ALLEGHENY PLATEAU.
THE COLD AIR PUSH DOESN/T LAST LONG AS ANOTHER RIDGE BUILDS OVER THE
REGION STARTING THURSDAY...BRINGING A RETURN TO SLIGHTLY WARMER THAN
NORMAL TEMPS THE END OF NEXT WEEK. A CLIPPER-TYPE SYSTEM SLIDES
THROUGH OVER THE WEEKEND...WITH LIMITED MOISTURE AND LOW POPS.
ANOTHER MORE SIG TROUGH COULD BE IN STORE FOR VERY LATE NEXT WEEKEND
INTO MONDAY - 10 DEC IF THE ECMWF...AND SEVERAL HIGHER END GEFS
MEMBERS ARE FOLLOWED. A DIFFERING AND FLATTER...MORE PROGRESSIVE
00/06Z GFS SOLUTION THAT FAR OUT CAUTIONS THAT THIS FORECAST PERIOD
CONTAINS LARGE AMOUNTS OF UNCERTAINTY.
&&
.AVIATION /16Z SATURDAY THROUGH WEDNESDAY/...
10 AM UPDATE...
LOW CLOUDS ARE HANGING TOUGH OVER ABOUT THE EASTERN HALF OF THE
FCST AREA...AFFECTING TERMINALS FROM UNV EASTWARD WITH MVFR/IFR
CEILINGS AND VIZ IN THE 4-6MI RANGE.
OF THE TERMINALS CURRENTLY SUB-VFR...UNV...BEING ON THE WESTERN
EDGE OF THE STRATUS AND MOST PRONE TO MIXING AND SOME
HEATING...WILL HAVE THE BEST CHANCE FOR SOME IMPROVEMENT FOR A
TIME THIS AFTERNOON. ELSEWHERE OVER THE SUSQ VALLEY THE CLOUDS
WILL BE TOUGH TO DISLODGE SO EXPECT CEILINGS TO REMAIN RATHER LOW
INTO SUNDAY.
WESTERN TERMINALS WILL REMAIN VFR INTO TONIGHT BEFORE THE LOW
CLOUDS BEGIN TO ENCROACH WESTWARD ONCE AGAIN.
OUTLOOK...
SUN...MVFR/IFR EAST. PM MVFR NW MTNS. SCT -SHRA.
MON...MVFR/IFR CIGS LKLY WEST.
TUE...VFR TO MVFR. PM SHRA LKLY.
WED...NO SIG WX EXPECTED.
&&
.CLIMATE...
NOVEMBER 2012 WAS A COLD AND DRY MONTH AT BOTH OFFICIAL CLIMATE
SITES. IT WAS AN EXCEPTIONALLY DRY MONTH AT WILLIAMSPORT.
AT WILLIAMSPORT...THE AVERAGE MONTHLY TEMPERATURE OF 39.6 DEGREES
TIED 1971 AS THE 25TH COLDEST NOVEMBER ON RECORD. THE TOTAL MONTHLY
PRECIPITATION OF 0.65 INCHES RANKED AS THE 5TH DRIEST NOVEMBER ON
RECORD. THE TOP 5 DRIEST NOVEMBER`S AT WILLIAMSPORT ARE:
1. 1904 - 0.51 INCHES
2. 1917 - 0.53 INCHES
3. 1908 - 0.56 INCHES
4. 1909 - 0.59 INCHES
5. 2012 - 0.65 INCHES
AT HARRISBURG...THE AVERAGE MONTHLY TEMPERATURE OF 40.7 DEGREES
RANKED AS THE 16TH COLDEST NOVEMBER ON RECORD. THE TOTAL MONTHLY
PRECIPITATION OF 1.05 INCHES RANKED AS THE 19TH DRIEST NOVEMBER ON
RECORD.
NO DAILY RECORDS WERE SET AT EITHER SITE DURING NOVEMBER 2012. A
CONTINUOUS WEATHER RECORD HAS BEEN KEPT AT HARRISBURG SINCE
1888...AND SINCE 1895 AT WILLIAMSPORT.
TODAY IS THE FIRST DAY OF DECEMBER...THE START OF METEOROLOGICAL
WINTER.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/STEINBUGL
NEAR TERM...LA CORTE/STEINBUGL
SHORT TERM...LAMBERT
LONG TERM...LAMBERT/RXR
AVIATION...LA CORTE/STEINBUGL
CLIMATE...STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
941 AM EST SAT DEC 1 2012
.SYNOPSIS...
ARCTIC HIGH PRESSURE OVER MAINE WILL RETREAT NORTHEAST THROUGH THE
CANADIAN MARITIMES INTO THE NORTHERN ATLANTIC BY SUNDAY. MEANWHILE A
WARM FRONT NEAR THE PENNSYLVANIA NEW YORK BORDER WILL LIFT SLOWLY
NORTH INTO NEW ENGLAND...AS A MILD SOUTHWEST FLOW OVERSPREADS THE
AREA AHEAD OF A COLD FRONT MOVING INTO THE GREAT LAKES. THIS
FRONTAL SYSTEM WILL BRING A FEW SHOWERS TO THE AREA LATER
SUNDAY...WITH A BETTER CHANCE FOR RAIN COMING ON TUESDAY WITH A
STRONGER COLD FRONT. TEMPERATURES WILL BE WELL ABOVE NORMAL EARLY
NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
9AM MORNING UPDATE...
LOW CLOUDS COVER ABOUT THE EASTERN 1/2 OF MY FCST AREA...WITH THE
WESTWARD MOVEMENT SEEMING TO HAVE SLOWED OR HALTED AS OF MID
MORNING. THE LATEST RAP FCST SOUNDINGS AND NAM MOS GUIDANCE INDICATE
THE STRATUS WILL BE VERY DIFFICULT TO DISLODGE OVR THE MID-LWR
SUSQ...WITH THE LLVL MSTR REMAINING TRAPPED UNDER STRONG INVERSION.
MADE ONLY SLIGHT TWEAKS TO THE SHORT TERM UPDATE.
PREVIOUS DISCUSSION...
THE EASTERLY MARITIME/UPSLOPE FLOW WILL BE TOPPED BY MODERATELY
STRONG MID-LVL WARM ADVECTION FROM THE SOUTHWEST...WHICH WILL
MAINTAIN LOW CLOUDS ACROSS CENTRAL AND ERN PENN. THE LOW CLOUDS
WILL EFFECTIVELY HOLD TEMPS IN THE UPPER 30S/LOW 40S OVR THE ERN
1/3 OF THE CWA. MEANWHILE...PARTLY TO MOSTLY SUNNY CONDS OVR THE
SWRN 1/2 OF THE AREA WILL ALLOW TEMPS TO CLIMB INTO THE UPPER 40S.
LOW LEVEL WINDS WILL TURN MORE SOUTHERLY TNT...WITH LOW CLOUDS
REMAINING OVR THE NRN AND ERN PARTS OF THE CWA. CLOUDS AND
INCREASING SLY FLOW AHEAD OF WEAK PAC FNTL SYS CROSSING THE GRT
LKS WILL BRING RELATIVELY MILD OVERNIGHT TEMPS IN 35-40F
RANGE...OR 5-10 DEGREES ABV NORMAL.
&&
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
SFC WARM FRONT WILL LIFT WELL TO THE NORTHEAST OF THE REGION EARLY
SUNDAY. A WEAK COLD FRONT WILL RACE EAST FROM THE OHIO VALLEY AND
SPREAD LOWERING AND THICKENING CLOUDS ACROSS THE NORTHWEST HALF F
THE CWA DURING THE MORNING FOLLOWED BY A SEVERAL TO 10 HOUR PERIOD
OF MAINLY LIGHT SHOWERS SUNDAY AFTERNOON AND NIGHT.
ACROSS THE APPROXIMATE SE HALF OF THE STATE....BKN-OVC CLOUD WILL BE
MAINLY IN THE FORM OF ALTO CU/ALTO STRATUS WITH SOME LIGHTER SHOWERS
LATE SUNDAY INTO EARLY MONDAY.
00Z OPERATIONAL MODEL/ENSEMBLE BLEND INDICATES THAT TOTAL RAINFALL
WITH THIS FRONT AND ASSOCIATED...FLAT UPPER SHORT WAVE WILL RANGE
FROM 3-4 TENTHS ACROSS THE NW MTNS...TO ONLY AROUND 0.10 OVER THE
LOWER SUSQ VALLEY.
SHOWERS WILL DIMINISH VERY EARLY MONDAY AS A RIDGE OF HIGH PRESSURE
AT THE SFC AND ALOFT BUILDS IN FROM THE WEST.
HIGH TEMPS SUNDAY WILL BE 10 TO 20 DEGREES ABOVE NORMAL SUNDAY
AFTERNOON...WITH THE GREATEST DEPARTURES OCCURRING ACROSS THE LAUREL
HIGHLANDS. HIGHS SUNDAY WILL RANGE FROM NEAR 50 ACROSS THE MTNS
NORTHEAST OF KIPT...TO THE LOWER 60S IN THE SOUTHWEST PART OF THE
CWA.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
BEHIND THE QUICK MOVING UPPER WAVE AND SFC FRONT...500 MB HEIGHTS
WILL RISE BY 30-40M...TO NEARLY PLUS 2 SIGMA MONDAY. THIS /COMBINED
WITH A NORTH/SOUTH SFC RIDGE BECOMING LOCATED RIGHT OVER THE REGION
MONDAY AFTERNOON/ WILL BRING PARTIAL CLEARING AT LEAST ACROSS THE
CENTRAL AND ERN VALLEYS...ALONG WITH CONTINUED UNSEASONABLY MILD
TEMPS IN THE MID 50S NORTH...TO AROUND 60F ACROSS THE SOUTH.
TUESDAY WILL CONTINUE THIS STRING OF WELL ABOVE NORMAL TEMPS WITH
SOME PERIODS OF PARTIAL SUNSHINE...FOLLOWED BY AN INCREASE IN LATE
DAY CLOUDS FROM THE WEST AHEAD OF THE NEXT COLD FRONT. A
GUSTY...DOWNSLOPING SOUTHWESTERLY WIND IN THE AFTERNOON WILL BLOW AT
15-20 KTS.
HIGHS TUESDAY SHOULD BE SIMILAR TO...IF NOT A FEW DEG F WARMER THAN
MONDAY/S QUITE BALMY TEMPS FOR EARLY DECEMBER.
A RATHER VIGOROUS MID/UPPER LEVEL TROUGH AND SFC COLD FRONT WILL
APPROACH FROM THE MIDWEST DURING THE DAY TUESDAY...AND COMBINE WITH
THE RIGHT ENTRANCE REGION OF A SWRLY 110 KT JET MAX TO BRING A
PERIOD OF SHOWERS...FOCUSED PRIMARILY IN THE LATE TUESDAY/TUESDAY
NIGHT TIMEFRAME.
OPERATIONAL MODEL/ENSEMBLE CONSENSUS QPF FORECAST IS BETWEEN 1-3
TENTHS OF AN INCH ACROSS THE SE HALF OF THE CWA THROUGH EARLY
WED...WITH AS MUCH AS 0.50 INCH OF RAINFL ACROSS THE NW MTNS.
A QUICK SURGE OF COLDER/ALBEIT GREATLY MODIFIED CP AIR WILL FOLLOW
FOR WEDNESDAY AND WEDNESDAY NIGHT WITH SCATTERED SNOW SHOWERS AND
PERHAPS SOME LIGHT ACCUMS ACROSS THE NW MTNS AS A SHARP MID/UPPER
LEVEL THERMAL TROUGH CROSSES THE REGION WITH THE SUBSIDENCE
INVERSION BASE RISING TO AROUND 5 KFT AGL WITH A DEEP AND
WELL-ALIGNED NWRLY FLOW TRANSPORTING LIMITED MOISTURE INLAND FROM
THE GLAKES.
FOR THE CENTRAL RIDGE AND VALLEY REGION...SPRINKLES AND FLURRIES OR
PERHAPS A FEW BRIEF RAIN/SNOW SHOWERS WILL SPILL SE OFF THE
ALLEGHENY PLATEAU.
THE COLD AIR PUSH DOESN/T LAST LONG AS ANOTHER RIDGE BUILDS OVER THE
REGION STARTING THURSDAY...BRINGING A RETURN TO SLIGHTLY WARMER THAN
NORMAL TEMPS THE END OF NEXT WEEK. A CLIPPER-TYPE SYSTEM SLIDES
THROUGH OVER THE WEEKEND...WITH LIMITED MOISTURE AND LOW POPS.
ANOTHER MORE SIG TROUGH COULD BE IN STORE FOR VERY LATE NEXT WEEKEND
INTO MONDAY - 10 DEC IF THE ECMWF...AND SEVERAL HIGHER END GEFS
MEMBERS ARE FOLLOWED. A DIFFERING AND FLATTER...MORE PROGRESSIVE
00/06Z GFS SOLUTION THAT FAR OUT CAUTIONS THAT THIS FORECAST PERIOD
CONTAINS LARGE AMOUNTS OF UNCERTAINTY.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
01/12 - 02/12
LOW MVFR CIGS AROUND 1KFT AGL WILL CONTINUE TO IMPACT THE ERN
TERMINALS MDT-IPT-LNS THIS MORNING. CIGS MAY GRADUALLY LIFT SOME
BY THE AFTN BUT SHOULD REMAIN MVFR. UNV REMAINS A TOUGH CALL WITH
LOW CLOUDS JUST EAST OF THE AIRFIELD PER IR SATL. WRN SITES IN ZOB
SECTOR EXPECTED TO REMAIN VFR. AS THE LLVL FLOW TURNS MORE THE
SOUTH...LOW CLOUDS SHOULD BE MORE WDSPRD TNT WITH MVFR CONDS LKLY
AT MOST AIRFIELDS.
OUTLOOK...
SUN...MVFR/IFR EAST. PM MVFR NW MTNS. SCT -SHRA.
MON...MVFR/IFR CIGS LKLY WEST.
TUE...VFR TO MVFR. PM SHRA LKLY.
WED...NO SIG WX EXPECTED.
&&
.CLIMATE...
NOVEMBER 2012 WAS A COLD AND DRY MONTH AT BOTH OFFICIAL CLIMATE
SITES. IT WAS AN EXCEPTIONALLY DRY MONTH AT WILLIAMSPORT.
AT WILLIAMSPORT...THE AVERAGE MONTHLY TEMPERATURE OF 39.6 DEGREES
TIED 1971 AS THE 25TH COLDEST NOVEMBER ON RECORD. THE TOTAL MONTHLY
PRECIPITATION OF 0.65 INCHES RANKED AS THE 5TH DRIEST NOVEMBER ON
RECORD. THE TOP 5 DRIEST NOVEMBER`S AT WILLIAMSPORT ARE:
1. 1904 - 0.51 INCHES
2. 1917 - 0.53 INCHES
3. 1908 - 0.56 INCHES
4. 1909 - 0.59 INCHES
5. 2012 - 0.65 INCHES
AT HARRISBURG...THE AVERAGE MONTHLY TEMPERATURE OF 40.7 DEGREES
RANKED AS THE 16TH COLDEST NOVEMBER ON RECORD. THE TOTAL MONTHLY
PRECIPITATION OF 1.05 INCHES RANKED AS THE 19TH DRIEST NOVEMBER ON
RECORD.
NO DAILY RECORDS WERE SET AT EITHER SITE DURING NOVEMBER 2012. A
CONTINUOUS WEATHER RECORD HAS BEEN KEPT AT HARRISBURG SINCE
1888...AND SINCE 1895 AT WILLIAMSPORT.
TODAY IS THE FIRST DAY OF DECEMBER...THE START OF METEOROLOGICAL WINTER.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/STEINBUGL
NEAR TERM...LA CORTE/STEINBUGL
SHORT TERM...LAMBERT
LONG TERM...LAMBERT/RXR
AVIATION...STEINBUGL
CLIMATE...
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1100 AM CST SAT DEC 01 2012
.DISCUSSION.../ISSUED AT 1100 AM CST/
STRATUS AND PATCHY FOG UNDER A LAYER OF HIGHER CLOUDS IS RAPIDLY
CLEARING BEHIND THE FRONT ACROSS SOUTH CENTRAL SD AND THE JAMES
VALLEY AREA THIS MORNING. WITH THE FRONT ADVANCING QUICKLY EASTWARD
AND DECENT POST FRONTAL MIXING...IT SHOULD BE A VERY MILD DAY FOR
THE FIRST DAY OF METEOROLOGICAL WINTER. TEMPERATURES IN
CHAMBERLAIN...WINNER AND AINSWORTH ARE WELL INTO THE 50S
ALREADY...SO BOOSTED TEMPERATURES A FEW DEGREES IN SOUTH CENTRAL SD.
CLOUDS LINGERING A BIT LONGER IN OUR FAR EASTERN COUNTIES WILL HOLD
BACK TEMPERATURES CLOSER TO 50...OTHERWISE HIGHS ARE ON TRACK FOR
THE LOW 50S TO LOW 60S. UPDATED CLOUD COVERAGE TO MATCH THE FASTER
CLEARING IN THE WESTERN HALF.
&
.AVIATION.../FOR THE 18Z TAF ISSUANCE/
STRATUS AND PATCHY IFR FOG ACROSS NORTHWEST IOWA AND SOUTHWEST
MINNESOTA WILL CONTINUE TO LIFT FROM WEST TO EAST THROUGH THE NEXT
FEW HOURS AS FRONT SWEEPS THROUGH THE AREA AND DRIER CONDITIONS
FILTER IN BEHIND IT. SOUTH TO SOUTHWEST WINDS GENERALLY 10 KT OR
LESS WILL SWITCH TO THE WEST TO NORTHWEST BEHIND THE FRONT.
&&
.PREV DISCUSSION.../ISSUED AT 335 AM CST/
SEEING SOME PATCHY FOG THIS MORNING ACROSS PORTIONS THE CWA. ALSO
HAVE AN EXPANDING STRATUS DECK STREAMING NORTH OUT OF KANSAS. NAM
AND RAP SEEM TO HAVE BEST HANDLE ON THE SITUATION...AND BOTH SUGGEST
THIS STRATUS MOVES INTO OUR IOWA COUNTIES NEAR 12Z. THINKING OUR
SOUTH DAKOTA COUNTIES AND MOST OF OUR MINNESOTA AREA SHOULD STAY
STRATUS FREE...ALTHOUGH WILL HAVE TO MONITOR TRENDS THIS MORNING.
HIGH TEMPERATURES A BIT TRICKY GIVEN THE STRATUS AND MID CLOUD DECK.
THINK MID CLOUD DECK CLEARS THIS AFTERNOON GIVING WAY TO MOSTLY
SUNNY SKIES. IF THE STRATUS MOVES IN...IT WILL LIKELY BE SLOW TO
ERODE AS THE COLD FRONT WASHES OUT ACROSS NORTHWEST IOWA AND THE
FLOW BECOMES WEAK. GENERALLY WENT ON THE WARMER SIDE OF GUIDANCE
WITH HIGHS IN THE 50S MOST PLACES...HOWEVER LOW CONFIDENCE ACROSS
NORTHWEST IOWA...WHERE HIGHS COULD BE SEVERAL DEGREES COOLER IF
STRATUS MOVES IN AND HANGS AROUND. WENT BELOW GUIDANCE FOR LOWS
TONIGHT WITH CLEAR SKIES AND GENERALLY LIGHT WINDS EXPECTED...TEMPS
SHOULD GET DOWN INTO THE MID AND UPPER 20S.
SUNDAY STILL LOOKS TO FEATURE WELL ABOVE NORMAL TEMPERATURES. COULD
BE SOME PATCHY MORNING FOG...HOWEVER THAT SHOULD QUICKLY GIVE WAY TO
MOSTLY SUNNY SKIES...WITH EVEN THE CIRRUS POTENTIAL LOOKING LOW.
WILL HAVE TO MIX OUT A STRONG MORNING INVERSION...AND ALTHOUGH WOULD
PREFER TO HAVE A BIT MORE WESTERLY COMPONENT TO THE WIND...A DECENT
SOUTHERLY BREEZE SHOULD HELP SOME WITH MIXING. THE NAM AND GEM
REGIONAL TEMPERATURE GUIDANCE SEEMS TO PERFORM BEST ON THESE WARM
DAYS...THUS WENT CLOSE TO THEM...GIVING MID AND UPPER 50S SOUTHWEST
MINNESOTA...TO THE MID 60S ALONG THE MISSOURI RIVER. SUNDAY NIGHT
WILL BE A MILD ONE...WITH A 40 TO 50 KT JET AT 900 MB KEEPING US
MIXED AND BREEZY THROUGH THE NIGHT. LOWS MOST PLACES WILL PROBABLY
REMAIN IN THE LOWER 40S.
A STRONGER COLD FRONT WILL PUSH ACROSS ON MONDAY. ANOTHER BATCH OF
LOW STRATUS AND FOG SHOULD ADVECT IN AHEAD OF THIS BOUNDARY MONDAY
MORNING EAST OF INTERSTATE 29. HOWEVER THE STRONG NORTHWEST PUSH
BEHIND THE FRONT SHOULD BRING MOSTLY SUNNY SKIES BY AFTERNOON. LOOKS
LIKE A DRY FRONTAL PASSAGE...WITH THE BEST DYNAMICS REMAINING TO OUR
NORTH. NOT THAT MUCH OF A COLD PUSH BEHIND THE FRONT...AND WITH GOOD
MIXING EXPECTED...HIGHS SHOULD NOT HAVE A PROBLEM RISING INTO THE
MID 50S MOST SPOTS. MODELS HAVE TRENDED WEAKER AND FURTHER NORTH
WITH THIS SYSTEM...AND THUS THE WINDS HAVE ALSO TRENDED DOWN A BIT.
ALTHOUGH STILL SHOULD BE A WINDY AFTERNOON...WITH NORTHWEST GUSTS UP
TO 40 MPH.
A MAINLY ZONAL FLOW CONTINUES INTO THE EXTENDED. COLD SHOT ON
TUESDAY CONTINUES TO LOOK WEAKER...WITH JUST ABOUT ALL THE COLD AIR
STAYING TO OUR NORTH. THUS HIGHS SHOULD REMAIN ABOVE NORMAL...40S
NORTH TO MID 50S SOUTH. RETURN SOUTHERLY FLOW ON WEDNESDAY BRINGS
THE WARMER LOW LEVEL TEMPERATURE PROFILES BACK INTO THE AREA.
HOWEVER THERE ARE SOME CLOUD COVER CONCERNS...AND IN FACT THE ECMWF
IS SHOWING A WAVE AND MAYBE EVEN A FEW SHOWERS. WILL LEAVE THE
FORECAST DRY WITH LIMITED MOISTURE IN THE LOW LEVELS...BUT CLOUDS
WILL PROBABLY KEEP TEMPERATURES FROM REACHING THEIR FULL
POTENTIAL...THUS WILL LEAVE CONSENSUS VALUES IN FOR NOW. NEXT COLD
FRONT WILL PUSH ACROSS WEDNESDAY NIGHT INTO THURSDAY. HOWEVER THIS
FRONT IS ALSO TRENDING WEAKER AND FURTHER NORTH. KEPT SOME POPS IN
THURSDAY AND THURSDAY NIGHT FOR CONTINUITY. HOWEVER THE ECMWF AND
GEM ARE NOW DRY AND THE GFS ENSEMBLE PROBABILITIES ARE VERY LOW.
THUS WOULD NOT BE SURPRISED IF FUTURE SHIFTS END UP TRIMMING BACK
POPS EVEN MORE. SHOULD TURN COOLER ON FRIDAY BEHIND THE FRONT...BUT
AGAIN NOT AS COLD AS IT ONCE LOOKED...WITH THE BRUNT OF THE COLD
AIRMASS PROBABLY STAYING TO OUR NORTH. /CHENARD
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
532 AM CST SAT DEC 01 2012
.DISCUSSION.../ISSUED AT 335 AM CST/
SEEING SOME PATCHY FOG THIS MORNING ACROSS PORTIONS THE CWA. ALSO
HAVE AN EXPANDING STRATUS DECK STREAMING NORTH OUT OF KANSAS. NAM
AND RAP SEEM TO HAVE BEST HANDLE ON THE SITUATION...AND BOTH SUGGEST
THIS STRATUS MOVES INTO OUR IOWA COUNTIES NEAR 12Z. THINKING OUR
SOUTH DAKOTA COUNTIES AND MOST OF OUR MINNESOTA AREA SHOULD STAY
STRATUS FREE...ALTHOUGH WILL HAVE TO MONITOR TRENDS THIS MORNING.
HIGH TEMPERATURES A BIT TRICKY GIVEN THE STRATUS AND MID CLOUD DECK.
THINK MID CLOUD DECK CLEARS THIS AFTERNOON GIVING WAY TO MOSTLY
SUNNY SKIES. IF THE STRATUS MOVES IN...IT WILL LIKELY BE SLOW TO
ERODE AS THE COLD FRONT WASHES OUT ACROSS NORTHWEST IOWA AND THE
FLOW BECOMES WEAK. GENERALLY WENT ON THE WARMER SIDE OF GUIDANCE
WITH HIGHS IN THE 50S MOST PLACES...HOWEVER LOW CONFIDENCE ACROSS
NORTHWEST IOWA...WHERE HIGHS COULD BE SEVERAL DEGREES COOLER IF
STRATUS MOVES IN AND HANGS AROUND. WENT BELOW GUIDANCE FOR LOWS
TONIGHT WITH CLEAR SKIES AND GENERALLY LIGHT WINDS EXPECTED...TEMPS
SHOULD GET DOWN INTO THE MID AND UPPER 20S.
SUNDAY STILL LOOKS TO FEATURE WELL ABOVE NORMAL TEMPERATURES. COULD
BE SOME PATCHY MORNING FOG...HOWEVER THAT SHOULD QUICKLY GIVE WAY TO
MOSTLY SUNNY SKIES...WITH EVEN THE CIRRUS POTENTIAL LOOKING LOW.
WILL HAVE TO MIX OUT A STRONG MORNING INVERSION...AND ALTHOUGH WOULD
PREFER TO HAVE A BIT MORE WESTERLY COMPONENT TO THE WIND...A DECENT
SOUTHERLY BREEZE SHOULD HELP SOME WITH MIXING. THE NAM AND GEM
REGIONAL TEMPERATURE GUIDANCE SEEMS TO PERFORM BEST ON THESE WARM
DAYS...THUS WENT CLOSE TO THEM...GIVING MID AND UPPER 50S SOUTHWEST
MINNESOTA...TO THE MID 60S ALONG THE MISSOURI RIVER. SUNDAY NIGHT
WILL BE A MILD ONE...WITH A 40 TO 50 KT JET AT 900 MB KEEPING US
MIXED AND BREEZY THROUGH THE NIGHT. LOWS MOST PLACES WILL PROBABLY
REMAIN IN THE LOWER 40S.
A STRONGER COLD FRONT WILL PUSH ACROSS ON MONDAY. ANOTHER BATCH OF
LOW STRATUS AND FOG SHOULD ADVECT IN AHEAD OF THIS BOUNDARY MONDAY
MORNING EAST OF INTERSTATE 29. HOWEVER THE STRONG NORTHWEST PUSH
BEHIND THE FRONT SHOULD BRING MOSTLY SUNNY SKIES BY AFTERNOON. LOOKS
LIKE A DRY FRONTAL PASSAGE...WITH THE BEST DYNAMICS REMAINING TO OUR
NORTH. NOT THAT MUCH OF A COLD PUSH BEHIND THE FRONT...AND WITH GOOD
MIXING EXPECTED...HIGHS SHOULD NOT HAVE A PROBLEM RISING INTO THE
MID 50S MOST SPOTS. MODELS HAVE TRENDED WEAKER AND FURTHER NORTH
WITH THIS SYSTEM...AND THUS THE WINDS HAVE ALSO TRENDED DOWN A BIT.
ALTHOUGH STILL SHOULD BE A WINDY AFTERNOON...WITH NORTHWEST GUSTS UP
TO 40 MPH.
A MAINLY ZONAL FLOW CONTINUES INTO THE EXTENDED. COLD SHOT ON
TUESDAY CONTINUES TO LOOK WEAKER...WITH JUST ABOUT ALL THE COLD AIR
STAYING TO OUR NORTH. THUS HIGHS SHOULD REMAIN ABOVE NORMAL...40S
NORTH TO MID 50S SOUTH. RETURN SOUTHERLY FLOW ON WEDNESDAY BRINGS
THE WARMER LOW LEVEL TEMPERATURE PROFILES BACK INTO THE AREA.
HOWEVER THERE ARE SOME CLOUD COVER CONCERNS...AND IN FACT THE ECMWF
IS SHOWING A WAVE AND MAYBE EVEN A FEW SHOWERS. WILL LEAVE THE
FORECAST DRY WITH LIMITED MOISTURE IN THE LOW LEVELS...BUT CLOUDS
WILL PROBABLY KEEP TEMPERATURES FROM REACHING THEIR FULL
POTENTIAL...THUS WILL LEAVE CONSENSUS VALUES IN FOR NOW. NEXT COLD
FRONT WILL PUSH ACROSS WEDNESDAY NIGHT INTO THURSDAY. HOWEVER THIS
FRONT IS ALSO TRENDING WEAKER AND FURTHER NORTH. KEPT SOME POPS IN
THURSDAY AND THURSDAY NIGHT FOR CONTINUITY. HOWEVER THE ECMWF AND
GEM ARE NOW DRY AND THE GFS ENSEMBLE PROBABILITIES ARE VERY LOW.
THUS WOULD NOT BE SURPRISED IF FUTURE SHIFTS END UP TRIMMING BACK
POPS EVEN MORE. SHOULD TURN COOLER ON FRIDAY BEHIND THE FRONT...BUT
AGAIN NOT AS COLD AS IT ONCE LOOKED...WITH THE BRUNT OF THE COLD
AIRMASS PROBABLY STAYING TO OUR NORTH. /CHENARD
&&
.AVIATION.../FOR THE 12Z TAF ISSUANCE/
OCCASIONAL IFR CEILINGS EAST OF I29 THROUGH 16Z THIS MORNING ALONG
WITH VISIBILITIES BELOW 3 MILES IN FOG. CONDITIONS SHOULD BECOME VFR
BY 16Z. ALSO LLWS NEAR 1000 FT WITH WIND DIRECTION AND SPEED 18035KT
ALONG AND EAST OF I29 THROUGH 16Z. WEST OF I29...VFR CONDITIONS
EXPECTED THROUGH THE FORECAST PERIOD WITH SOUTH WINDS GRADUALLY
SHIFTING TO THE WEST TODAY.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
335 AM CST SAT DEC 01 2012
.DISCUSSION.../ISSUED AT 335 AM CST/
SEEING SOME PATCHY FOG THIS MORNING ACROSS PORTIONS THE CWA. ALSO
HAVE AN EXPANDING STRATUS DECK STREAMING NORTH OUT OF KANSAS. NAM
AND RAP SEEM TO HAVE BEST HANDLE ON THE SITUATION...AND BOTH SUGGEST
THIS STRATUS MOVES INTO OUR IOWA COUNTIES NEAR 12Z. THINKING OUR
SOUTH DAKOTA COUNTIES AND MOST OF OUR MINNESOTA AREA SHOULD STAY
STRATUS FREE...ALTHOUGH WILL HAVE TO MONITOR TRENDS THIS MORNING.
HIGH TEMPERATURES A BIT TRICKY GIVEN THE STRATUS AND MID CLOUD DECK.
THINK MID CLOUD DECK CLEARS THIS AFTERNOON GIVING WAY TO MOSTLY
SUNNY SKIES. IF THE STRATUS MOVES IN...IT WILL LIKELY BE SLOW TO
ERODE AS THE COLD FRONT WASHES OUT ACROSS NORTHWEST IOWA AND THE
FLOW BECOMES WEAK. GENERALLY WENT ON THE WARMER SIDE OF GUIDANCE
WITH HIGHS IN THE 50S MOST PLACES...HOWEVER LOW CONFIDENCE ACROSS
NORTHWEST IOWA...WHERE HIGHS COULD BE SEVERAL DEGREES COOLER IF
STRATUS MOVES IN AND HANGS AROUND. WENT BELOW GUIDANCE FOR LOWS
TONIGHT WITH CLEAR SKIES AND GENERALLY LIGHT WINDS EXPECTED...TEMPS
SHOULD GET DOWN INTO THE MID AND UPPER 20S.
SUNDAY STILL LOOKS TO FEATURE WELL ABOVE NORMAL TEMPERATURES. COULD
BE SOME PATCHY MORNING FOG...HOWEVER THAT SHOULD QUICKLY GIVE WAY TO
MOSTLY SUNNY SKIES...WITH EVEN THE CIRRUS POTENTIAL LOOKING LOW.
WILL HAVE TO MIX OUT A STRONG MORNING INVERSION...AND ALTHOUGH WOULD
PREFER TO HAVE A BIT MORE WESTERLY COMPONENT TO THE WIND...A DECENT
SOUTHERLY BREEZE SHOULD HELP SOME WITH MIXING. THE NAM AND GEM
REGIONAL TEMPERATURE GUIDANCE SEEMS TO PERFORM BEST ON THESE WARM
DAYS...THUS WENT CLOSE TO THEM...GIVING MID AND UPPER 50S SOUTHWEST
MINNESOTA...TO THE MID 60S ALONG THE MISSOURI RIVER. SUNDAY NIGHT
WILL BE A MILD ONE...WITH A 40 TO 50 KT JET AT 900 MB KEEPING US
MIXED AND BREEZY THROUGH THE NIGHT. LOWS MOST PLACES WILL PROBABLY
REMAIN IN THE LOWER 40S.
A STRONGER COLD FRONT WILL PUSH ACROSS ON MONDAY. ANOTHER BATCH OF
LOW STRATUS AND FOG SHOULD ADVECT IN AHEAD OF THIS BOUNDARY MONDAY
MORNING EAST OF INTERSTATE 29. HOWEVER THE STRONG NORTHWEST PUSH
BEHIND THE FRONT SHOULD BRING MOSTLY SUNNY SKIES BY AFTERNOON. LOOKS
LIKE A DRY FRONTAL PASSAGE...WITH THE BEST DYNAMICS REMAINING TO OUR
NORTH. NOT THAT MUCH OF A COLD PUSH BEHIND THE FRONT...AND WITH GOOD
MIXING EXPECTED...HIGHS SHOULD NOT HAVE A PROBLEM RISING INTO THE
MID 50S MOST SPOTS. MODELS HAVE TRENDED WEAKER AND FURTHER NORTH
WITH THIS SYSTEM...AND THUS THE WINDS HAVE ALSO TRENDED DOWN A BIT.
ALTHOUGH STILL SHOULD BE A WINDY AFTERNOON...WITH NORTHWEST GUSTS UP
TO 40 MPH.
A MAINLY ZONAL FLOW CONTINUES INTO THE EXTENDED. COLD SHOT ON
TUESDAY CONTINUES TO LOOK WEAKER...WITH JUST ABOUT ALL THE COLD AIR
STAYING TO OUR NORTH. THUS HIGHS SHOULD REMAIN ABOVE NORMAL...40S
NORTH TO MID 50S SOUTH. RETURN SOUTHERLY FLOW ON WEDNESDAY BRINGS
THE WARMER LOW LEVEL TEMPERATURE PROFILES BACK INTO THE AREA.
HOWEVER THERE ARE SOME CLOUD COVER CONCERNS...AND IN FACT THE ECMWF
IS SHOWING A WAVE AND MAYBE EVEN A FEW SHOWERS. WILL LEAVE THE
FORECAST DRY WITH LIMITED MOISTURE IN THE LOW LEVELS...BUT CLOUDS
WILL PROBABLY KEEP TEMPERATURES FROM REACHING THEIR FULL
POTENTIAL...THUS WILL LEAVE CONSENSUS VALUES IN FOR NOW. NEXT COLD
FRONT WILL PUSH ACROSS WEDNESDAY NIGHT INTO THURSDAY. HOWEVER THIS
FRONT IS ALSO TRENDING WEAKER AND FURTHER NORTH. KEPT SOME POPS IN
THURSDAY AND THURSDAY NIGHT FOR CONTINUITY. HOWEVER THE ECMWF AND
GEM ARE NOW DRY AND THE GFS ENSEMBLE PROBABILITIES ARE VERY LOW.
THUS WOULD NOT BE SURPRISED IF FUTURE SHIFTS END UP TRIMMING BACK
POPS EVEN MORE. SHOULD TURN COOLER ON FRIDAY BEHIND THE FRONT...BUT
AGAIN NOT AS COLD AS IT ONCE LOOKED...WITH THE BRUNT OF THE COLD
AIRMASS PROBABLY STAYING TO OUR NORTH. /CHENARD
&&
.AVIATION.../FOR THE 06Z TAF ISSUANCE/
MVFR FOG AND A FEW AREAS OF IFR WITH CEILINGS BELOW 1K FEET AND
VISIBILITIES 1-3SM LIKELY TO REMAIN STEADY THROUGH 14Z OR ABATE
SLOWLY FROM THE WEST. STRONG LOW LEVEL FLOW ABOVE THE SURFACE WILL
LIKELY KEEP CONDITIONS FROM GENERALLY WORSENING DURING THE REST OF
THE NIGHT. THE SAME STRENGTHENING LOW LEVEL FLOW SHOULD KEEP
GENERALLY VFR CONDITIONS OVER SOUTHEAST SD. KFSD AND KSUX TAF SITES
WILL BE ON THE EDGE AND COULD POSSIBLY DROP TO 5SM BUT WILL PROBABLY
KEEP OUT OF TAFS GIVEN INDICATIONS OF HOW STRONG THOSE WINDS JUST
ABOVE THE SURFACE ARE GETTING. AFTER 15Z CONDITIONS IN SOUTHWEST MN
AND NORTHWEST IA WILL IMPROVE TO VFR FROM THE WEST...THOUGH THE
SOUTHEAST CORNER OF THE AREA FROM SOUTH OF SPW TO SLB COULD SEE SOME
DEEPER AND LONGER LASTING STRATUS IN THE MORNING. WHATEVER LINGERS
INTO THE AFTERNOON IF ANYTHING SHOULD RAPIDLY IMPROVE AFTER 18Z WITH
APPROACH AND ARRIVAL OF SURFACE TROUGH.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1216 PM CST SAT DEC 1 2012
.UPDATE...
UPDATED FOR 18Z AVIATION DISCUSSION.
&&
.PREV DISCUSSION... /ISSUED 905 AM CST SAT DEC 1 2012/
.UPDATE...
UPDATED TO ADD SLIGHT CHANCE OF SPRINKLES ACROSS THE WEST
DISCUSSION...
A FEW MINOR CHANGES TO THE FORECAST THIS MORNING. FIRST A FEW
LIGHT RAIN SHOWERS ARE BEGINNING TO POP UP ON LZK RADAR. THIS
ACTIVITY IS BEING PICKED UP FROM THE RUC MODEL...AND FORECASTED TO
MOVE INTO THE WESTERN MIDSOUTH COUNTIES IN THE NEXT HOUR OR TWO.
SO HAVE PLACED A SLIGHT CHANCE OF SPRINKLES IN THIS REGION THROUGH
LATE AFTERNOON. ALSO ADJUSTED CLOUD COVER OVER THE EAST AND
SOUTHEAST COUNTIES FOR THE DAY WHERE IT APPEARS MOSTLY SUNNY
SKIES WILL PREVAIL. LAST...MADE SLIGHT INCREASES IN WIND SPEEDS
AND POTENTIAL GUSTS DURING THE MIDDAY HOURS TO AREAS WEST OF A
DYERSBURG TENNESSEE TO CHARLESTON MISSISSIPPI LINE.
JAB
&&
.PREV DISCUSSION... /ISSUED 549 AM CST SAT DEC 1 2012/
DISCUSSION...
UPDATED AVIATION DISCUSSION FOR 12Z TAFS.
PREV DISCUSSION... /ISSUED 349 AM CST SAT DEC 1 2012/
DISCUSSION...
MILD WEATHER FOR EARLY DECEMBER TO PREVAIL THROUGH MONDAY...
COURTESY OF DEEP SOUTHERLY LOW LEVEL FLOW AND LOW AMPLITUDE
RIDGING ALOFT.
AN OPEN UPPER LEVEL TROF WILL APPROACH THE MIDSOUTH FROM THE
SOUTHERN PLAINS MONDAY NIGHT. AN ASSOCIATED SURFACE COLD FRONT
WILL MOVE INTO THE MIDSOUTH DURING THE DAY TUESDAY... TRACKING
EASTWARD WITH THE MID LEVEL TROF PASSAGE. SURFACE HIGH PRESSURE OF
PACIFIC ORIGIN WILL ENTER THE MIDSOUTH LATE TUESDAY...WHILE AN
ARCTIC SURFACE HIGH TRACKS EASTWARD THROUGH THE NORTHERN GREAT
LAKES.
RAINFALL SHOULD END OVER THE MIDSOUTH LATE TUESDAY INTO TUESDAY
EVENING. FAIR WEATHER IS FORECAST FOR THE MIDWEEK PERIODS...WITH
AFTERNOON MAX TEMPS LOWER...BUT STILL WELL ABOVE NORMAL. LOW
DEWPOINTS WILL RESULT IN WIDE DIURNAL TEMPERATURE RANGES WEDNESDAY
AND THURSDAY.
GFS AND ECMWF MODELS BRING A ANOTHER OPEN MID LATITUDE TROF AND
ASSOCIATED PACIFIC SURFACE COLD FRONT ACROSS THE PLAINS AND LOWER
MS RIVER VALLEY LATE NEXT WEEK. HOWEVER... SIGNIFICANT TIMING
DIFFERENCES WERE SHOWN ON THE 00Z/01 RUNS. THE ECMWF HAS SHOWN
GREATER RUN TO RUN CONSISTENCY AND ITS SLOWER TIMING WAS FAVORED
FOR THE MORNING FORECAST PACKAGE. AS SUCH...LOW LEVEL MOISTURE
SHOULD INCREASE FRIDAY...ACCOMPANIED BY MILD TEMPERATURES. A
PACIFIC COLD FRONTAL PASSAGE SHOULD FOLLOW FRIDAY NIGHT INTO EARLY
SATURDAY.
PWB
&&
.AVIATION...
18Z TAF CYCLE
BIGGEST CONSIDERATION THIS AFTERNOON ARE WIND GUSTS IN THE
NORTHWEST PART OF THE CWA. EXPECT LOW CEILINGS TMR MORNING.
WER
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 70 58 72 60 / 0 10 10 0
MKL 69 54 70 57 / 0 10 10 0
JBR 67 55 70 57 / 20 10 10 10
TUP 69 51 71 55 / 0 0 0 0
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
905 AM CST SAT DEC 1 2012
.UPDATE...
UPDATED TO ADD SLIGHT CHANCE OF SPRINKLES ACROSS THE WEST
&&
.DISCUSSION...
A FEW MINOR CHANGES TO THE FORECAST THIS MORNING. FIRST A FEW
LIGHT RAIN SHOWERS ARE BEGINNING TO POP UP ON LZK RADAR. THIS
ACTIVITY IS BEING PICKED UP FROM THE RUC MODEL...AND FORECASTED TO
MOVE INTO THE WESTERN MIDSOUTH COUNTIES IN THE NEXT HOUR OR TWO.
SO HAVE PLACED A SLIGHT CHANCE OF SPRINKLES IN THIS REGION THROUGH
LATE AFTERNOON. ALSO ADJUSTED CLOUD COVER OVER THE EAST AND
SOUTHEAST COUNTIES FOR THE DAY WHERE IT APPEARS MOSTLY SUNNY
SKIES WILL PREVAIL. LAST...MADE SLIGHT INCREASES IN WIND SPEEDS
AND POTENTIAL GUSTS DURING THE MIDDAY HOURS TO AREAS WEST OF A
DYERSBURG TENNESSEE TO CHARLESTON MISSISSIPPI LINE.
JAB
&&
.PREV DISCUSSION... /ISSUED 549 AM CST SAT DEC 1 2012/
DISCUSSION...
UPDATED AVIATION DISCUSSION FOR 12Z TAFS.
PREV DISCUSSION... /ISSUED 349 AM CST SAT DEC 1 2012/
DISCUSSION...
MILD WEATHER FOR EARLY DECEMBER TO PREVAIL THROUGH MONDAY...
COURTESY OF DEEP SOUTHERLY LOW LEVEL FLOW AND LOW AMPLITUDE
RIDGING ALOFT.
AN OPEN UPPER LEVEL TROF WILL APPROACH THE MIDSOUTH FROM THE
SOUTHERN PLAINS MONDAY NIGHT. AN ASSOCIATED SURFACE COLD FRONT
WILL MOVE INTO THE MIDSOUTH DURING THE DAY TUESDAY... TRACKING
EASTWARD WITH THE MID LEVEL TROF PASSAGE. SURFACE HIGH PRESSURE OF
PACIFIC ORIGIN WILL ENTER THE MIDSOUTH LATE TUESDAY...WHILE AN
ARCTIC SURFACE HIGH TRACKS EASTWARD THROUGH THE NORTHERN GREAT
LAKES.
RAINFALL SHOULD END OVER THE MIDSOUTH LATE TUESDAY INTO TUESDAY
EVENING. FAIR WEATHER IS FORECAST FOR THE MIDWEEK PERIODS...WITH
AFTERNOON MAX TEMPS LOWER...BUT STILL WELL ABOVE NORMAL. LOW DEWPOINTS
WILL RESULT IN WIDE DIURNAL TEMPERATURE RANGES WEDNESDAY AND THURSDAY.
GFS AND ECMWF MODELS BRING A ANOTHER OPEN MID LATITUDE TROF AND
ASSOCIATED PACIFIC SURFACE COLD FRONT ACROSS THE PLAINS AND LOWER
MS RIVER VALLEY LATE NEXT WEEK. HOWEVER... SIGNIFICANT TIMING
DIFFERENCES WERE SHOWN ON THE 00Z/01 RUNS. THE ECMWF HAS SHOWN
GREATER RUN TO RUN CONSISTENCY AND ITS SLOWER TIMING WAS FAVORED
FOR THE MORNING FORECAST PACKAGE. AS SUCH...LOW LEVEL MOISTURE
SHOULD INCREASE FRIDAY...ACCOMPANIED BY MILD TEMPERATURES. A
PACIFIC COLD FRONTAL PASSAGE SHOULD FOLLOW FRIDAY NIGHT INTO EARLY
SATURDAY.
PWB
&&
.AVIATION...
12Z TAF CYCLE
VFR CONDITIONS EXPECTED THROUGHOUT THE FORECAST PERIOD. ONLY
THING CLOSE IS THE CEILINGS TODAY...EXPECT MOST CLOUDS TO BE ABOVE
FOUR THOUSAND FEET. WINDS WILL PICK UP THIS AFTERNOON WITH WESTERN
SITES SEEING SOME GUSTY WINDS AS ATMOSPHERE MIXES DOWN TO THE
SURFACE. TLSJR
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 70 57 71 60 / 0 10 10 0
MKL 69 54 70 57 / 0 10 10 0
JBR 67 57 71 57 / 20 10 10 10
TUP 69 51 71 55 / 0 0 0 0
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
350 PM CDT SAT DEC 1 2012
.VERY SHORT TERM...TONIGHT AND SUNDAY.
AREA OF STRONG ISENTROPIC LIFT IN SOUTHWEST WI AT 18Z IS SHIFTING
ENE THIS AFTERNOON. THE NAM 290K PRESSURE ADVECTION PLOT SHOWS THIS
AREA WELL...AND BRINGS IT TO MILWAUKEE AROUND 22Z. THIS AREA IS ALSO
DEPICTED ON RADAR BY AN AREA OF SHOWERS OVER CENTRAL PORTIONS OF THE
FORECAST AREA EARLY THIS AFTERNOON. THEY ARE SPREADING EAST QUICKLY.
IT IS POSSIBLE THAT THE FEW HIGHER RETURNS ON THE RADAR HAVE SOME
THUNDER...AS RAP AND NAM SOUNDINGS SHOW WEAK ELEVATED CAPE ABOVE
5000 FEET.
THE ISENTROPIC LIFT COINCIDES WITH WEAK VORTICITY ADVECTION
ASSOCIATED WITH A MID LEVEL SHORTWAVE...850/700MB MOISTURE
CONVERGENCE...AND WEAK UPPER DIVERGENCE TO SUPPORT LIGHT RAIN LATE
THIS AFTERNOON THROUGH THE FIRST HALF OF THE EVENING...ESPECIALLY IN
SOUTHEAST WI. THEN THE MOISTURE AND PRESSURE ADVECTION WILL LINGER
ACROSS THE SOUTHEAST HALF OF WI THROUGH AROUND MIDNIGHT...UNTIL THE
NEXT WEAK 500MB SHORTWAVE SWEEPS THROUGH AND KICKS OUT THE SURFACE
TROUGH.
RAIN SHOWERS SHOULD KEEP REGENERATING THROUGH THE EVENING IN THE
SOUTHEAST...BUT THERE IS A GOOD CHANCE THAT THE RAIN WEST OF MADISON
IS DONE AND ONLY DRIZZLE AND FOG WILL BE THE CONCERN THE REST OF THE
EVENING.
THERE IS SOME CONCERN FOR DENSE FOG TO DEVELOP THIS EVENING IN SOUTH
CENTRAL WI WHILE WAITING FOR THAT NEXT SHORTWAVE...AND ALSO LATE
TONIGHT JUST BEHIND THE SURFACE TROUGH...ESPECIALLY AROUND SUNRISE
TIME. FAR SOUTHEAST WI WILL HAVE THE LIMITING FACTOR OF BRISK WEST
WINDS JUST ABOVE THE SURFACE. THE WESTERN FORECAST AREA INCLUDING
MADISON LOOKS LIKE IT HAS THE BEST CHANCE OF DENSE FOG OVERNIGHT.
NOT QUITE CONFIDENT ENOUGH AT THIS TIME TO ISSUE ANY HEADLINES
THOUGH.
DEWPOINT TEMPS SHOULD ONLY DROP A COUPLE OF DEGREES BEHIND THIS COLD
FRONT BY SUNDAY MORNING. DRIER AIR WILL MOVE IN ALOFT WITH MID LEVEL
RIDGING. EXPECTING SUNSHINE TO BEGIN SPREADING INTO SOUTHERN WI BY
MID SUNDAY MORNING AND ACROSS THE WHOLE AREA BY SUNDAY AFTERNOON.
THIS SHOULD ALLOW HIGHS TO CREEP INTO THE UPPER 50S FAR SOUTH.
.SHORT TERM...SUNDAY NIGHT THROUGH TUESDAY.
WEAK FRONTAL BOUNDARY EXPECTED TO SLOG THROUGH SOUTHERN WI LATER
TONIGHT AND SUNDAY AND WILL BECOME NEARLY STATIONARY ACROSS
NORTHERN/CENTRAL IL BY SUNDAY EVENING. INCREASING SOUTHERLY LOW
LEVEL WINDS LATER SUNDAY NIGHT AND MONDAY WILL CARRY WARM FRONT
RAPIDLY NORTHWARD. INITIALLY CLEAR SKIES...LIGHT WINDS AND DEWPTS IN
THE LOW TO MID 40S WILL ALLOW PATCHY FOG TO DEVELOP SUNDAY EVENING.
NOT EXPECTING VISIBILITIES TO GET TO LOW HOWEVER AS BOUNDARY LAYER
MIXING INCREASES AFTER MIDNIGHT.
QUITE A BIT OF CLOUDINESS EXPECTED ON MONDAY...EVEN AFTER WARM FRONT
PASSES TO THE NORTH. CLOUDS AND BREEZY SOUTH WINDS SHOULD KEEP
DAYTIME TEMPERATURES FROM GETTING TOO WARM...HOWEVER WITH 925H TEMPS
RISING TO AROUND 13C...WILL BE FLIRTING WITH RECORD HIGHS FOR 3 DEC.
RECORDS MOSTLY IN THE 60 TO 65 DEGREE RANGE.
PREFER SLOWER MOVEMENT OF SURFACE FRONT FROM MORE CONSISTENT ECMWF
AND NAM SOLUTIONS. HENCE MORE TIME FOR RETURN OF DEEPER COLUMN
MOISTURE AS PWAT VALUES RETURN TO AROUND THREE QUARTERS INCH. SHORT
TERM GUIDANCE IN AGREEMENT ON CARRYING LOW LEVEL FRONTOGENETICAL
FORCING ACROSS SRN WI DURING THE AFTN AND EARLY EVENING. HENCE WL
KEEP LIKELY POPS GOING AND ADD LIKELY WORDING TO EAST IN THE
EVENING. SOUNDINGS SHOWING SOME ELEVATED INSTABILITY...HOWEVER
ELEVATED CIN REMAINS AROUND OR HIGHER THAN 50 J/KG. WL HOLD OFF ON
INTRODUCING ISOLD T FOR NOW.
DRIER...COOLER AIR SWEEPS IN MONDAY NIGHT BUT COLDEST AIR REMAINS TO
THE NORTH. COLDEST AIR REMAINS TO THE NORTH...AND ONLY GLANCES
ACROSS SOUTHERN WI TUESDAY AFTERNOON AND EVE. LOW LEVELS REMAIN DRY
SO NO PRECIP EXPECTED WITH THIS SECONDARY CDFNT.
.LONG TERM...TUESDAY NIGHT THROUGH SATURDAY.
SOUTHERN WI RECEIVES GLANCING BLOW FROM SURGE OF COLDER AIR
ASSOCIATED WITH SECONDARY FRONT TUESDAY NIGHT. LIGHT WINDS AND
COLDER AIR SHOULD RESULT IN TEMPS DROPPING TO AROUND SEASONAL
NORMALS TUESDAY NIGHT. THERMAL TROUGH QUICKLY PUSHES OFF TO THE EAST
ON WEDNESDAY AS LOW TO MID LEVEL RIDGING MOVES ACROSS THE REGION.
WARM AIR ADVECTION AHEAD OF NEXT SHORT WAVE ENERGY DEVELOPS ON
WEDNESDAY WITH STRONG LOW LEVEL WINDS AND INCREASING MOISTURE WED
NGT INTO THURSDAY. ENOUGH INCREASING COLUMN MOISTURE WITH PWAT
VALUES CLIMBING TO AROUND THREE QUARTERS INCH TO WARRANT SMALL POPS
FOR LIGHT PRECIP IN PARTS OF THE AREA WEDNESDAY NIGHT INTO THURSDAY
MORNING. LATEST DETERMINISTIC RUNS OF ECMWF AND GFS INCREASES
FORWARD SPEED OF PIECE OF SHORT WAVE ENERGY MOVING THROUGH THE
WESTERLIES. MAIN SYNOPTIC FORCING WITH THIS FEATURE NOW EXPECTED TO
AFFECT SRN WI ON THU/THU EVE...SO WL CONTINUE TO BUMP UP POPS ACROSS
THE CWA DURING THIS PERIOD.
PROGRESSIVE FLOW WILL CARRY THIS FEATURE TO THE EAST LATER THU NIGHT
AS COLDER...DRIER AIR SETTLES INTO THE REGION FOR FRIDAY. GEM...
ECMWF AND UKMT HINTING AT UPSTREAM RIDGING TAKING ON HIGHER
AMPLITUDE LATE IN THE WEEK WITH MORE W-NW FLOW CARRYING COLDER AIR
INTO THE REGION AND LINGERING THRU THE WEEKEND. ALTHOUGH LATEST
DETERMINISTIC GFS NOT AS COLD...GFS 5 DAY 500H ANOMOLIES CONTINUE TO
SHOW BROADSCALE TROFING SETTLING OVER THE UPPER MIDWEST BY THE
WEEKEND WITH NEGATIVE ANOMOLIES OF 75-100M OVER WI BY AROUND 00Z/12.
MAJORITY OF GFS ENSEMBLE MEMBERS AT MID-UPPER LEVELS ALSO FAVOR
COLDER SCENARIO. THIS WOULD RESULT IN MORE PERSISTENT SEASONAL TEMPS
FOR THE SECOND FULL WEEK OF DEC.
&&
.AVIATION /00Z TAFS/...
A WARM FRONT IS PUSHING THROUGH SOUTHERN WISCONSIN THIS AFTERNOON AS
LOW PRESSURE TRACKS ACROSS NORTHERN MINNESOTA TO JUST NORTH OF LAKE
SUPERIOR. LIGHT RAIN IS SPREADING ACROSS SOUTHERN WI WITH A SURGE OF
MOISTURE PUSHING INTO THE AREA. LIGHT RAIN SHOWERS SHOULD KEEP
REGENERATING IN SOUTHEAST WI...BUT ONLY EXPECTING DRIZZLE WEST OF
MADISON THE REST OF THE EVENING.
EXPECT LINGERING IFR/LIFR LOW CLOUDS...FOG AND DRIZZLE THROUGH MID
SUNDAY MORNING BEFORE THE DRIER AIR AND HIGH PRESSURE CAN TAKE OVER.
THERE IS A CHANCE FOR DENSE FOG FOR A PERIOD OF TIME LATE
TONIGHT/EARLY SUN MORNING JUST AFTER THE LOW PRESSURE TROUGH PASSES
THROUGH...ESPECIALLY NEAR MADISON AND WEST.
&&
.MARINE...
SOUTH WINDS SHOULD GUST TO AROUND 25 KNOTS THROUGH AROUND
MIDNIGHT...THEN DIMINISH AS THEY VEER TO THE WEST BEHIND A PASSING
COLD FRONT/SURFACE LOW PRESSURE TROUGH.
PERSISTENT SOUTH WINDS ARE BUILDING HIGH WAVES. SMALL CRAFT ADVISORY
IN EFFECT THROUGH 10Z TONIGHT. WAVES WILL SUBSIDE AFTER MIDNIGHT
WITH THE OFFSHORE DIMINISHING WINDS.
SMALL CRAFT ADVISORY CONDITIONS WILL LIKELY BE MET ONCE AGAIN MONDAY
WITH SOUTH WINDS AHEAD OF A STRONGER LOW PRESSURE SYSTEM.
&&
.CONFIDENCE...
TONIGHT AND SUNDAY...LOW TO MEDIUM.
SUNDAY NIGHT...MEDIUM.
MONDAY AND MONDAY NIGHT...MEDIUM.
TUESDAY AND TUESDAY NIGHT...MEDIUM TO HIGH.
WEDNESDAY THROUGH THURSDAY...LOW TO MEDIUM.
FRIDAY AND SATURDAY...MEDIUM.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY LMZ643>646 TIL 10Z/02.
&&
$$
VERY SHORT TERM/AVIATION/MARINE...MRC
SHORT TERM/LONG TERM...MBK
AREA FORECAST DISCUSSION...UPDATED
NWS TAMPA BAY RUSKIN FL
455 AM EST MON DEC 3 2012
.UPDATE...
BASED ON LATEST EARLY MORNING SATELLITE TRENDS AND LOCAL HI-RES NWP
GUIDANCE...HAVE INCREASED THE SKY COVER QUITE A BIT FOR THE FIRST
PORTION OF THE MORNING OVER MUCH OF THE REGION. ALTHOUGH LITTLE
MOVEMENT IS CURRENTLY SEEN IN THIS CLOUD DECK...THERE ARE MODEL
INDICATIONS THAT WE WILL BEGIN TO SEE THE AREA PIVOT WEST AND
NORTHWEST WITH TIME...AND ALSO BEGIN TO SCT OUT LATER THIS MORNING.
HAVE TRIED TO INCORPORATE THIS TREND INTO THE SKY GRIDS OVER THE
NEXT 4-6 HOURS BRINGING A MIX OF SUN AND CLOUDS BACK TO THE FORECAST
BY MIDDAY.
&&
.SYNOPSIS...
08Z WATER VAPOR AND H4 RAP ANALYSIS SHOW A GENERALLY UNAMPLIFIED
UPPER LEVEL PATTERN ACROSS THE CONUS. NORTHERN STREAM FLOW IS
COMPRISED OF SHORTWAVE ENERGY EJECTING EASTWARD FROM THE
INTER-MOUNTAIN WEST FOLLOWED DOWNSTREAM BY LONGWAVE RIDGING OVER THE
MIDWEST...AND THEN FINALLY ANOTHER SHORTWAVE TROUGH EXITING THE NEW
ENGLAND STATES TOWARD THE CANADIAN MARITIMES. CLOSER TO HOME...OUR
FORECAST AREA RESIDES UNDER WEAK UPPER RIDGING COVERING THE GULF OF
MEXICO/SE CONUS. THE INFLUENCE OF THIS RIDGING CAN BE SEEN ON THE
03/00Z KTBW SOUNDING PROFILE...WHICH SHOWED A WELL-DEFINED
SUBSIDENCE INVERSION AT AROUND 800MB. A RATHER DRY MID/UPPER LEVEL
COLUMN ABOVE THIS FEATURE RESULTED IN A PW VALUE OF UNDER 1".
AT THE SURFACE...HIGH PRESSURE IS IN CONTROL OF THE REGION WITH A
SURFACE RIDGE AXIS EXTENDING FROM OFF THE SE CONUS COAST BACK
WESTWARD THROUGH SOUTHERN GA/AL. GRADIENT AROUND THIS RIDGE
CONTINUES TO PROVIDE THE REGION WITH AN EASTERLY LOW LEVEL FLOW.
THIS FLOW IS BRINGING WITH IT AMPLE BOUNDARY LAYER MOISTURE THIS
MORNING. SCT-BK CLOUDS RESULTING FROM THIS MOISTURE ARE OCCASIONALLY
WORKING THEIR WAY WESTWARD ACROSS THE PENINSULA. AREAS OF FOG HAVE
BEGUN TO DEVELOP TO THE NORTH OF TAMPA BAY AND WILL HIGHLIGHT SOME
DENSE FOG POTENTIAL IN THE GRIDS FOR THE NATURE COAST ZONES...
ESPECIALLY NORTH OF BROOKSVILLE.
&&
.SHORT TERM (TODAY THROUGH WEDNESDAY)...
TODAY/TONIGHT/TUESDAY...STACKED RIDGING AND LARGE SCALE SUPPRESSION
WILL BE THE DOMINANT PLAYER IN OUR WEATHER THROUGH TUESDAY. UPPER
LEVEL RIDGE WILL EVEN SHARPEN SOMEWHAT DURING THE NEXT 24 HOURS IN
RESPONSE TO HEIGHT FALLS SPREADING EASTWARD OVER THE SOUTHERN
PLAINS. THE FORECAST UNDER THIS PATTERN WILL BE GENERALLY DRY WITH
ABOVE NORMAL TEMPERATURES. TYPICAL OF THIS TYPE OF EASTERLY FLOW
PATTERN...WILL CONTINUE TO SEE SHALLOW SPEED CONVERGENCE FOCUS
SHOWERS FORMING FROM TIME TO TIME ALONG THE EAST COAST OF FLORIDA...
AND THEN HEADING INLAND. THE MAJORITY OF THIS LIGHT SHOWER/SPRINKLE
ACTIVITY WILL DISSIPATE BEFORE REACHING OUR ZONES...HOWEVER A FEW
ISOLATED CELLS CAN NOT BE RULED OUT THIS FAR WEST. THE CHANCE OF ANY
MEASURABLE RAINFALL IS VERY LOW DUE TO THE EXTREMELY SHALLOW NATURE
OF THE AVAILABLE MOISTURE. SIMILAR DIURNAL MIXING HEIGHTS TO WHAT
OCCURRED SUNDAY ARE ANTICIPATED THE NEXT COUPLE OF DAYS. MIXING TO
BETWEEN 875-850MB TODAY AND TUESDAY WILL YIELD HIGH TEMPERATURES
INTO THE UPPER 70S/LOW 80 FOR MANY LOCATIONS. LOW TEMP RANGE BY
SUNRISE FROM THE LOWER 50S AT NORMALLY COLDER INLAND SPOTS TO LOWER
60S AT NORMALLY WARMER COASTAL LOCATIONS.
TUESDAY NIGHT/WEDNESDAY...UPPER RIDGE OVER THE FL PENINSULA RAPIDLY
BREAKS DOWN TUESDAY NIGHT/EARLY WEDNESDAY AS SHORTWAVE ENERGY
APPROACHES AND OVERSPREAD THE REGION FROM THE NORTHWEST. GLOBAL
GUIDANCE CONTINUES TO EVOLVE THE DETAILS OF THIS ENERGY SLIGHTLY
DIFFERENT...WITH THE GFS FURTHER NORTH AND MORE PROGRESSIVE THAN THE
ECMWF. SURFACE COLD FRONT ASSOCIATED WITH THIS ENERGY WILL ALSO BE
APPROACHING FROM THE NORTHWEST. SIMILAR TO THE PAST SEVERAL
FRONTS...THIS BOUNDARY LOOKS TO "LOSE STEAM" AND BEGIN TO WASH OUT
AS IT REACHES THE I-10 CORRIDOR LATE WEDNESDAY. DESPITE AT LEAST
SOME DEEP LAYER QG FORCING/SYNOPTIC SUPPORT AHEAD OF THE SHORTWAVE
DURING THE DAY ON WEDNESDAY...THE LACK OF COINCIDENT COLUMN MOISTURE
AND FADING FRONTAL FOCUS IN THE LOWER LEVELS WILL LIKELY KEEP RAIN
CHANCES LOW. A FEW ISOLATED SHOWERS/SPRINKLES SHOULD BE IN THE AREA
WEDNESDAY...HOWEVER...IMPACTS WILL BE VERY MINOR/NIL WITH REGARDS TO
OUTDOOR ACTIVITIES...AND WILL KEEP POPS AT AROUND 10%. LOWERED
HEIGHTS AND THE POTENTIAL FOR MORE CLOUDS AHEAD OF THE SHORTWAVE
WOULD KEEP DAYTIME TEMPS DOWN A FEW DEGREES FROM PREVIOUS DAYS...BUT
SHOULD NOT SEE ANY SIGNIFICANT DEPARTURES ON EITHER SIDE OF NORMAL.
&&
.LONG TERM (THURSDAY THROUGH NEXT SUNDAY)...
U/L TROUGH WILL PUSH ACROSS THE REGION WEDNESDAY NIGHT WITH MAIN
ENERGY REMAINING WELL NORTH OF THE FORECAST AREA. ONLY A SLIGHT
CHANCE OF A SHOWER AS AN ASSOCIATED COLD FRONT STALLS ACROSS NORTH
FLORIDA. U/L PATTERN WILL BECOME INCREASINGLY ZONAL ACROSS THE U.S.
THURSDAY THROUGH SATURDAY. SURFACE HIGH PRESSURE WILL BUILD OVER
THE MID ATLANTIC WITH EASTERLY BOUNDARY LAYER FLOW ACROSS THE
PENINSULA. PARTLY CLOUDY MILD DRY CONDITIONS EACH DAY. PATTERN
WILL AMPLIFY ON SUNDAY WITH A TROUGH DEVELOPING OVER THE WESTERN
U.S. WHICH WILL BUILD A RIDGE OVER FLORIDA AND THE EASTERN
SEABOARD. BUILDING HEIGHTS WILL ALLOW TEMPERATURES TO CLIMB SEVERAL
DEGREES ABOVE CLIMATIC NORMALS.
&&
.AVIATION...
EASTERLY FLOW OFF THE ATLANTIC WILL GENERATE SCT CLDS 060-070 TODAY
WITH LCL BKN CIGS060 UNDER A STRONG SUBSIDENCE INVERSION.
&&
.MARINE...
A RIDGE OF HIGH PRESSURE NORTH OF THE REGION WILL PROVIDE A
CONTINUED EASTERLY FLOW THROUGH TUESDAY OVER THE COASTAL WATERS OF
THE EASTERN GULF OF MEXICO. A BRIEF PERIOD OF NEAR CAUTIONARY LEVEL
WINDS IS POSSIBLE TONIGHT...MAINLY SOUTH OF TAMPA BAY. THE LOCAL
GRADIENT AND WIND FIELDS ARE THEN EXPECTED TO WEAKEN DURING THE
MIDDLE OF THE WEEK AS A COLD FRONT APPROACHES AND WEAKENS OVER THE
NORTHEAST GULF. EASTERLY FLOW WILL THEN RE-DEVELOP FOR THE END OF
THE WEEK AS HIGH PRESSURE ONCE AGAIN BUILDS TO THE NORTH OF THE
REGION.
&&
.FIRE WEATHER...
SURFACE HIGH PRESSURE WILL RESIDE TO THE NORTH OF THE AREA THE NEXT
COUPLE OF DAYS PROVIDING AN EASTERLY FLOW AND ABUNDANT LOW LEVEL
ATLANTIC MOISTURE. A COLD FRONT WILL APPROACH FROM THE NORTHWEST
WEDNESDAY AND WEDNESDAY NIGHT...BUT IS EXPECTED TO WEAKEN WITHOUT
MUCH OVERALL INFLUENCE ON THE REGION. HIGH PRESSURE WILL ONCE AGAIN
BUILD TO OUR NORTH FOR THE END OF THE WEEK. NO SIGNIFICANT FIRE
WEATHER CONCERNS ARE ANTICIPATED THROUGH THE NEXT SEVERAL DAYS.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 81 61 78 58 / 0 0 0 0
FMY 80 58 79 57 / 0 10 10 10
GIF 81 55 78 55 / 0 10 10 10
SRQ 80 58 77 58 / 0 0 0 10
BKV 81 52 78 50 / 0 10 0 0
SPG 78 63 76 62 / 0 0 0 0
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/MARINE/FIRE WX...MROCZKA
AVIATION/LONG TERM...OGLESBY
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
318 AM EST MON DEC 3 2012
.DISCUSSION...
TODAY-TONIGHT...THE H100-H70 RIDGE AXIS THAT HAS DOMINATED THE LCL
WX PATTERN FOR THE PAST SEVERAL DAYS HAS SHIFTED SLIGHTLY SWD IN
RESPONSE TO A SHORT WAVE TROF PUSHING OFF THE ERN SEABOARD. THIS HAS
RESULTED A LOW LVL WNDSHFT TO THE E/SE AS SEEN ON THE USAF 915HZ
PROFILER AS WELL AS THE 00Z KJAX SOUNDING. WINDS N OF SEBASTIAN
INLET HAVE DIMINISHED AS WELL WITH THE RIDGE AXIS RELOCATING TO THE
FL/GA BOARDER.
RELATIVELY HIGH MOISTURE ALONG THE E FL COAST WITH H100-H70
MEAN RH VALUES BTWN 70-80PCT...H100-H85 VALUES ABV 85PCT. EVEN
SO...RADAR HAS SEEN NIL PRECIP OVER THE PAST FEW HRS OUTSIDE OF THE
GULF STREAM. FURTHERMORE...LATEST RAP ANALYSIS SHOWS UPSTREAM
MOISTURE DIMINISHING TO AOB 50PCT THRU THE H100-H70 LYR WITH SINKING
MID/UPR LVL AIR (MID LVL OMEGA POSITIVE...UPR LVL DIVERGENCE
NEGATIVE). SAT TREND CONFIRMS THIS WITH DIMINISHING STRATOCU LYR
ARND THE LAKE OKEECHOBEE REGION.
MOS GUIDANCE KEEPS PRECIP CHANCES IN THE SINGLE DIGITS THRU 12Z TUE
WITH SFC DEWPOINTS FALLING INTO THE M/U50S...GFS MODEL SOUNDINGS
MAINTAIN A STOUT H85-H70 SUBSIDENCE INVERSION WITH PWAT VALUES
FALLING TO 0.7"-0.8". CAN SEE NO REASON TO QUESTION THE OUTPUT...
WILL KEEP THE FCST DRY. LITTLE CHANGE IN TEMPS FROM THE PAST FEW
DAYS AS THE PERSISTENT ONSHORE FLOW KEEPS CENTRAL FL BATHED IN WARM
OCEAN MODIFIED AIR. MAXES M/U70S COAST...L80S INTERIOR. MINS L/M60S
COAST...M/U50S INTERIOR.
TUE-FRI...HIGH PRESSURE RIDGE WILL PERSIST INTO TUESDAY THEN
WEAKEN BY WEDNESDAY AS A SHORTWAVE APPROACHES. ASSOCIATED SURFACE
FRONTAL BOUNDARY WILL REACH INTO NORTH FLORIDA BEFORE DIMINISHING
MID WEEK WITH HIGH PRESSURE TO THE NORTH BRIDGING THE BOUNDARY INTO
THURSDAY AND FRI. MAY HAVE ISOLATED COASTAL SHOWERS TUES NIGHT...
MAINLY TREASURE COAST...THEN LOW POPS MAINLY NORTHERN COASTAL
COUNTIES BY LATE THURS INTO FRI WITH SOME INCREASED MOISTURE ALONG
THE BOUNDARY AND ONSHORE FLOW. TEMPS WILL REMAIN A LITTLE ABOVE
EARLY DEC CLIMO NORMS THROUGH THE LATE WEEK WITH HIGHS IN THE
MID/UPPER 70S. OVERNIGHT LOWS RANGING FROM MID/UPPER 50S OVER
NORTHERN AND INTERIOR SECTIONS...AND AROUND 60/LOWER 60S ALONG THE
COAST FROM BREVARD COUNTY SOUTHWARD.
SAT-SUN...INFLUENCE OF OLD FRONTAL BOUNDARY WILL WANE BY THE
UPCOMING WEEKEND AS HIGH PRESSURE TO THE NORTH SLIDES EAST OVER THE
ATLANTIC AND LOW LEVEL FLOW VEERS TOWARD A MORE SE-S COMPONENT. THIS
PATTERN WILL KEEP EC FL TEMPS WARMER THAN AVERAGE WITH SOME INTERIOR
LOCATIONS APPROACCHING 80F FOR HIGHS AND OVERNIGHT LOWS IN THE LOWER
TO MID 60S MOST AREAS. RAIN CHANCES BELOW MENTIONABLE VALUES OVER
THE WEEKEND...BUT STILL SOME INDICATION BY MEDIUM RANGE MODELS THAT
RAIN CHANCES MAY GO UP EARLY NEXT WEEK...BUT BEYOND DAY 7 FORECAST.
&&
.AVIATION...THRU 04/00Z...VFR ALL SITES...CIGS BTWN FL060-080 THRU
03/16Z.
&&
.MARINE...TODAY-TONIGHT...HIGH PRES RIDGE DRIFTING DOWN THE ERN
SEABOARD WILL FORCE WINDS TO VEER TO THE E/SE AND DIMINISH. LATEST
DATA BUOY/C-MAN OBS SHOW THIS TREND ALREADY TAKING PLACE ACRS THE
LCL ATLC N OF SEBASTIAN INLET. SEAS REMAIN ARND 6FT...JUST BLO SCA
CRITERIA... LARGELY DUE TO A 4-5FT LONG PD SWELL. THE E/NE FETCH N
OF THE BAHAMAS LENGTH REMAINS QUITE LONG...THOUGH WITH THE RIDGE
PUSHING S IT WILL GRADUALLY LOSE ITS ABILITY TO MAINTAIN THE
INCOMING SWELL TRAIN. WILL CANCEL THE SCA OVER THE OFFSHORE WATERS
AND REPLACE IT WITH A CAUTIONARY STATEMENT FOR SEAS.
TUE-FRI...ONSHORE FLOW WILL PERSIST INTO THE LATE WEEK. WIND SPEEDS
GRADUALLY DECREASE INTO THE MID WEEK BUT THEN PICK UP AGAIN HEADING
INTO THE LATE WEEK WITH HIGH PRESSURE BRIDGING OLD FRONTAL BOUNDARY
AND CAUTIONARY HEADLINES MAY AGAIN BE NEEDED OVER A PORTION OF THE
LOCAL WATERS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 76 60 75 56 / 10 0 10 10
MCO 79 58 78 56 / 10 0 10 10
MLB 77 62 75 60 / 0 0 10 20
VRB 77 62 76 59 / 0 0 10 20
LEE 78 57 77 55 / 10 0 0 10
SFB 79 58 78 57 / 10 0 10 10
ORL 79 58 78 57 / 10 0 10 10
FPR 77 61 75 59 / 0 0 10 20
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...BRAGAW
LONG TERM....GLITTO
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
300 AM EST MON DEC 3 2012
.SYNOPSIS...
08Z WATER VAPOR AND H4 RAP ANALYSIS SHOW A GENERALLY UNAMPLIFIED
UPPER LEVEL PATTERN ACROSS THE CONUS. NORTHERN STREAM FLOW IS
COMPRISED OF SHORTWAVE ENERGY EJECTING EASTWARD FROM THE
INTER-MOUNTAIN WEST FOLLOWED DOWNSTREAM BY LONGWAVE RIDGING OVER THE
MIDWEST...AND THEN FINALLY ANOTHER SHORTWAVE TROUGH EXITING THE NEW
ENGLAND STATES TOWARD THE CANADIAN MARITIMES. CLOSER TO HOME...OUR
FORECAST AREA RESIDES UNDER WEAK UPPER RIDGING COVERING THE GULF OF
MEXICO/SE CONUS. THE INFLUENCE OF THIS RIDGING CAN BE SEEN ON THE
03/00Z KTBW SOUNDING PROFILE...WHICH SHOWED A WELL-DEFINED
SUBSIDENCE INVERSION AT AROUND 800MB. A RATHER DRY MID/UPPER LEVEL
COLUMN ABOVE THIS FEATURE RESULTED IN A PW VALUE OF UNDER 1".
AT THE SURFACE...HIGH PRESSURE IS IN CONTROL OF THE REGION WITH A
SURFACE RIDGE AXIS EXTENDING FROM OFF THE SE CONUS COAST BACK
WESTWARD THROUGH SOUTHERN GA/AL. GRADIENT AROUND THIS RIDGE
CONTINUES TO PROVIDE THE REGION WITH AN EASTERLY LOW LEVEL FLOW.
THIS FLOW IS BRINGING WITH IT AMPLE BOUNDARY LAYER MOISTURE THIS
MORNING. SCT-BK CLOUDS RESULTING FROM THIS MOISTURE ARE OCCASIONALLY
WORKING THEIR WAY WESTWARD ACROSS THE PENINSULA. AREAS OF FOG HAVE
BEGUN TO DEVELOP TO THE NORTH OF TAMPA BAY AND WILL HIGHLIGHT SOME
DENSE FOG POTENTIAL IN THE GRIDS FOR THE NATURE COAST ZONES...
ESPECIALLY NORTH OF BROOKSVILLE.
&&
.SHORT TERM (TODAY THROUGH WEDNESDAY)...
TODAY/TONIGHT/TUESDAY...STACKED RIDGING AND LARGE SCALE SUPPRESSION
WILL BE THE DOMINANT PLAYER IN OUR WEATHER THROUGH TUESDAY. UPPER
LEVEL RIDGE WILL EVEN SHARPEN SOMEWHAT DURING THE NEXT 24 HOURS IN
RESPONSE TO HEIGHT FALLS SPREADING EASTWARD OVER THE SOUTHERN
PLAINS. THE FORECAST UNDER THIS PATTERN WILL BE GENERALLY DRY WITH
ABOVE NORMAL TEMPERATURES. TYPICAL OF THIS TYPE OF EASTERLY FLOW
PATTERN...WILL CONTINUE TO SEE SHALLOW SPEED CONVERGENCE FOCUS
SHOWERS FORMING FROM TIME TO TIME ALONG THE EAST COAST OF FLORIDA...
AND THEN HEADING INLAND. THE MAJORITY OF THIS LIGHT SHOWER/SPRINKLE
ACTIVITY WILL DISSIPATE BEFORE REACHING OUR ZONES...HOWEVER A FEW
ISOLATED CELLS CAN NOT BE RULED OUT THIS FAR WEST. THE CHANCE OF ANY
MEASURABLE RAINFALL IS VERY LOW DUE TO THE EXTREMELY SHALLOW NATURE
OF THE AVAILABLE MOISTURE. SIMILAR DIURNAL MIXING HEIGHTS TO WHAT
OCCURRED SUNDAY ARE ANTICIPATED THE NEXT COUPLE OF DAYS. MIXING TO
BETWEEN 875-850MB TODAY AND TUESDAY WILL YIELD HIGH TEMPERATURES
INTO THE UPPER 70S/LOW 80 FOR MANY LOCATIONS. LOW TEMP RANGE BY
SUNRISE FROM THE LOWER 50S AT NORMALLY COLDER INLAND SPOTS TO LOWER
60S AT NORMALLY WARMER COASTAL LOCATIONS.
TUESDAY NIGHT/WEDNESDAY...UPPER RIDGE OVER THE FL PENINSULA RAPIDLY
BREAKS DOWN TUESDAY NIGHT/EARLY WEDNESDAY AS SHORTWAVE ENERGY
APPROACHES AND OVERSPREAD THE REGION FROM THE NORTHWEST. GLOBAL
GUIDANCE CONTINUES TO EVOLVE THE DETAILS OF THIS ENERGY SLIGHTLY
DIFFERENT...WITH THE GFS FURTHER NORTH AND MORE PROGRESSIVE THAN THE
ECMWF. SURFACE COLD FRONT ASSOCIATED WITH THIS ENERGY WILL ALSO BE
APPROACHING FROM THE NORTHWEST. SIMILAR TO THE PAST SEVERAL
FRONTS...THIS BOUNDARY LOOKS TO "LOSE STEAM" AND BEGIN TO WASH OUT
AS IT REACHES THE I-10 CORRIDOR LATE WEDNESDAY. DESPITE AT LEAST
SOME DEEP LAYER QG FORCING/SYNOPTIC SUPPORT AHEAD OF THE SHORTWAVE
DURING THE DAY ON WEDNESDAY...THE LACK OF COINCIDENT COLUMN MOISTURE
AND FADING FRONTAL FOCUS IN THE LOWER LEVELS WILL LIKELY KEEP RAIN
CHANCES LOW. A FEW ISOLATED SHOWERS/SPRINKLES SHOULD BE IN THE AREA
WEDNESDAY...HOWEVER...IMPACTS WILL BE VERY MINOR/NIL WITH REGARDS TO
OUTDOOR ACTIVITIES...AND WILL KEEP POPS AT AROUND 10%. LOWERED
HEIGHTS AND THE POTENTIAL FOR MORE CLOUDS AHEAD OF THE SHORTWAVE
WOULD KEEP DAYTIME TEMPS DOWN A FEW DEGREES FROM PREVIOUS DAYS...BUT
SHOULD NOT SEE ANY SIGNIFICANT DEPARTURES ON EITHER SIDE OF NORMAL.
&&
.LONG TERM (THURSDAY THROUGH NEXT SUNDAY)...
U/L TROUGH WILL PUSH ACROSS THE REGION WEDNESDAY NIGHT WITH MAIN
ENERGY REMAINING WELL NORTH OF THE FORECAST AREA. ONLY A SLIGHT
CHANCE OF A SHOWER AS AN ASSOCIATED COLD FRONT STALLS ACROSS NORTH
FLORIDA. U/L PATTERN WILL BECOME INCREASINGLY ZONAL ACROSS THE U.S.
THURSDAY THROUGH SATURDAY. SURFACE HIGH PRESSURE WILL BUILD OVER
THE MID ATLANTIC WITH EASTERLY BOUNDARY LAYER FLOW ACROSS THE
PENINSULA. PARTLY CLOUDY MILD DRY CONDITIONS EACH DAY. PATTERN
WILL AMPLIFY ON SUNDAY WITH A TROUGH DEVELOPING OVER THE WESTERN
U.S. WHICH WILL BUILD A RIDGE OVER FLORIDA AND THE EASTERN
SEABOARD. BUILDING HEIGHTS WILL ALLOW TEMPERATURES TO CLIMB SEVERAL
DEGREES ABOVE CLIMATIC NORMALS.
&&
.AVIATION...
EASTERLY FLOW OFF THE ATLANTIC WILL GENERATE SCT CLDS 060-070 TODAY
WITH LCL BKN CIGS060 UNDER A STRONG SUBSIDENCE INVERSION.
&&
.MARINE...
A RIDGE OF HIGH PRESSURE NORTH OF THE REGION WILL PROVIDE A
CONTINUED EASTERLY FLOW THROUGH TUESDAY OVER THE COASTAL WATERS OF
THE EASTERN GULF OF MEXICO. A BRIEF PERIOD OF NEAR CAUTIONARY LEVEL
WINDS IS POSSIBLE TONIGHT...MAINLY SOUTH OF TAMPA BAY. THE LOCAL
GRADIENT AND WIND FIELDS ARE THEN EXPECTED TO WEAKEN DURING THE
MIDDLE OF THE WEEK AS A COLD FRONT APPROACHES AND WEAKENS OVER THE
NORTHEAST GULF. EASTERLY FLOW WILL THEN RE-DEVELOP FOR THE END OF
THE WEEK AS HIGH PRESSURE ONCE AGAIN BUILDS TO THE NORTH OF THE
REGION.
&&
.FIRE WEATHER...
SURFACE HIGH PRESSURE WILL RESIDE TO THE NORTH OF THE AREA THE NEXT
COUPLE OF DAYS PROVIDING AN EASTERLY FLOW AND ABUNDANT LOW LEVEL
ATLANTIC MOISTURE. A COLD FRONT WILL APPROACH FROM THE NORTHWEST
WEDNESDAY AND WEDNESDAY NIGHT...BUT IS EXPECTED TO WEAKEN WITHOUT
MUCH OVERALL INFLUENCE ON THE REGION. HIGH PRESSURE WILL ONCE AGAIN
BUILD TO OUR NORTH FOR THE END OF THE WEEK. NO SIGNIFICANT FIRE
WEATHER CONCERNS ARE ANTICIPATED THROUGH THE NEXT SEVERAL DAYS.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 81 61 78 58 / 0 0 0 0
FMY 80 58 79 57 / 0 10 10 10
GIF 81 55 78 55 / 0 10 10 10
SRQ 80 58 77 58 / 0 0 0 10
BKV 81 52 78 50 / 0 10 0 0
SPG 78 63 76 62 / 0 0 0 0
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/MARINE/FIRE WX...MROCZKA
AVIATION/LONG TERM...OGLESBY
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1145 PM CST SUN DEC 2 2012
...UPDATE TO AVIATION...
.DISCUSSION...
SHORT TERM FORECAST (TONIGHT AND MONDAY)...
AT 21Z SURFACE OBSERVATIONS AND ASSOCIATED RAP ANALYSIS INDICATES A
DECENT PRESSURE GRADIENT FORMING ACROSS EASTERN KANSAS IN RESPONSE
TO A LEE SIDE SURFACE TROUGH FORMING ON THE EAST SIDE OF THE
ROCKIES...OVER THE CENTRAL HIGH PLAINS. THIS PRESSURE GRADIENT HAS
ALLOWED FOR SOUTHERLY FLOW TO INCREASE THROUGH OUT THE DAY AS WARM
AND MOIST AIR MOVES INTO THE AREA. ALTHOUGH DEWPOINTS THROUGHOUT THE
AREA ARE ONLY IN THE LOWER TO MID 40S OBSERVATIONS FROM ACROSS
OK..AR..AND SOUTHERN MISSOURI INDICATE THAT A DECENT AMOUNT OF LOW
LEVEL MOISTURE IN THE FORM OF UPPER 50 TO LOWER 60 DEGREE DEWPOINTS
RESIDES AND IS POISED TO MAKE A SURGE NORTHWARD AS THE PREVIOUSLY
MENTIONED TROUGH MOVES OFF THE HIGH PLAINS. DIFFICULT FORECAST
REMAINS FOR THE OVERNIGHT HOURS AS THE MOISTURE SURGES NORTH. GIVEN
THE SHALLOW NATURE OF THE GOOD MOISTURE WITH VERY DRY AIR ABOVE THE
LOW LEVEL MOISTURE WILL RULE OUT MEASURABLE PRECIPITATION FOR THE
OVERNIGHT HOURS...HOWEVER A LOW STRATUS DECK DOES SEEM RATHER LIKELY
WITH POSSIBLY SOME VERY MINOR DRIZZLE. ALSO WILL NOT RULE OUT THE
POSSIBILITY OF SOME PATCHY FOG AS SOME MODEL GUIDANCE SUGGESTS AREAS
OF REDUCED VISIBILITY...ESPECIALLY ALONG AND EAST OF HIGHWAY 75.
CANNOT COMPLETELY RULE OUT DENSE FOG OVERNIGHT...ESPECIALLY IN THE
AFOREMENTIONED FAR EASTERN KANSAS AREAS...BUT GIVEN THE FACT THAT
SOUTHERLY WINDS OF AROUND 10 TO 20 MPH WILL BE PERSISTENT FOR MUCH
OF THE NIGHT THE FEELING IS THAT THE LOWER ATMOSPHERE MAY BE TOO
MIXED TO CONSIDER WIDESPREAD DENSE FOG. LOW STRATUS/FOG WILL LIKELY
REMAIN IN THE AREA THROUGH THE MID MORNING BEFORE MIXING GRADUALLY
DISSIPATES THE STRATUS BY MID MORNING/EARLY AFTERNOON. FOR MONDAY WE
CAN EXPECT ONE MORE DAY WITH TEMPS NEARLY 25 DEGREES WARMER THAN
SEASONAL NORMALS. A COLD FRONT STANDS POISED TO MOVE THROUGH THE
AREA DURING THE DAY ON MONDAY. ALTHOUGH THIS FRONT WILL ACT TO BRING
TEMPS DOWN A FEW DEGREES IT WILL HARDLY BRING THE SURGE OF COLD AIR
TYPICALLY ASSOCIATED WITH DECEMBER AS TEMPS FOR THE MIDDLE PART OF
THE WEEK WILL REMAIN WELL ABOVE NORMAL.
JL
LONG TERM - TUESDAY THROUGH SUNDAY...
TUESDAY THROUGH WEDNESDAY NIGHT - THE COLD FRONT WILL HAVE PASSED
COMPLETELY THROUGH THE FORECAST AREA BY MONDAY EVENING AND ANY
PRECIPITATION SHOULD HAVE SHIFTED SOUTHEAST WITH THE FRONT. COLD
AND DRY ADVECTION WILL TAKE PLACE INTO TUESDAY BUT A NORTH BREEZE
OVERNIGHT WILL KEEP TUESDAY MORNING LOWS IN THE 30S AND THE WARM
START ALONG WITH DECENT MIXING SHOULD ALLOW AFTERNOON HIGHS TO
GET INTO THE LOWER 60S. RETURN FLOW WITH SOME WARM MOIST ADVECTION
WILL THEN TAKE OVER BY WEDNESDAY AS A WEAK SHORT WAVE TROUGH AND
SURFACE LOW PRESSURE MOVE INTO THE NORTHERN HIGH PLAINS. WHILE
TEMPERATURES ALOFT WILL BE WARMER ON WEDNESDAY...COULD SEE MORE IN
THE WAY OF CLOUDS AND LESS MIXING...RESULTING IN HIGHS STILL IN
THE LOWER 60S. MORE SUN COULD ALLOW HIGHS TO SNEAK INTO THE UPPER
60S IN A FEW SPOTS THOUGH. EXPECT LOW CLOUDS TO FILL IN FURTHER BY
WEDNESDAY NIGHT AS THE LOW LEVEL MOISTURE INFLUX INCREASES.
CLOUDS WILL KEEP LOWS WARMER.
THURSDAY THROUGH FRIDAY - A COLD FRONT ASSOCIATED WITH THE
NORTHERN PLAINS SHORT WAVE TROUGH WILL MOVE THROUGH THE FORECAST
AREA DURING THE DAY ON THURSDAY WITH ANOTHER ROUND OF MORE
SUBSTANTIAL COLD ADVECTION IN ITS WAKE. THERE WILL BE A DECENT
AMOUNT OF LOW LEVEL FORCING ALONG THE FRONT AND IT WILL INTERACT
WITH A FAIR AMOUNT OF GULF MOISTURE...BUT UPPER SUPPORT IS LACKING
AND SUSPECT THAT THE END RESULT MAY BE SIMILAR TO THE FRONTAL
PASSAGE ON MONDAY WITH THE BULK OF PRECIPITATION DEVELOPING
SOUTHEAST OF THE FORECAST AREA. HAVE STILL KEPT AT LEAST A CHANCE
OF SHOWERS ACROSS THE SOUTHEAST HALF OF THE FORECAST AREA FOR
UNCERTAINTY IN FRONTAL TIMING AND AT LEAST THE POTENTIAL FOR
EARLIER PRECIP DEVELOPMENT WHILE THE FRONT IS STILL IN THE LOCAL
AREA. THE BOUNDARY SHOULD PUSH SOUTHEAST OF THE FORECAST AREA BY
EARLY FRIDAY MORNING WITH A COOLER AND DRIER AIRMASS FILTERING IN.
FRIDAY NIGHT THROUGH SUNDAY - UNCERTAINTY IS HIGH DURING THIS
PERIOD REGARDING PRECIPITATION POTENTIAL WITH SIGNIFICANT MODEL
VARIANCE. MUCH OF THE VARIABILITY IS DUE TO HOW THE FLOW PATTERN
OVER THE PACIFIC OCEAN WILL EVOLVE IN THE NEXT FEW DAYS. IT DOES
APPEAR THAT A TRANSITION TO A MORE SOUTHWESTERLY FLOW PATTERN OVER
THE CENTRAL AND EASTERN CONUS WILL HAPPEN IN THE LONG TERM WITH
MOISTURE LINGERING NOT FAR TO THE SOUTH AND OCCASIONAL
DISTURBANCES INTERACTING WITH A FRONTAL BOUNDARY. HOWEVER THE
TIMING OF THE DISTURBANCES AND THE LOCATION OF THE FRONT ARE VERY
MUCH IN QUESTION. THE END RESULT FOR THIS FORECAST IS ACTUALLY FOR
COOLER...BUT NEAR NORMAL TEMPERATURES DURING THIS PERIOD WITH SOME
POTENTIAL FOR A STORM SYSTEM TO BRING PRECIPITATION TO THE REGION
BY THE WEEKEND. CURRENTLY HAVE INDICATED RAIN IN THE FORECAST...
BUT THERE WOULD BE AT LEAST SOME POTENTIAL FOR A BIT OF
SNOW...DEPENDING ON PRECIPITATION TIMING.
BARJENBRUCH
&&
.AVIATION...
LLVL MOISTURE MOVING NORTHWARD INTO SOUTHERN KS WILL SURGE BACK
INTO THE TERMINALS AFT 09Z WHICH WILL INITIALLY RESULT IN MVFR
STRATUS AND FOG FORMATION...THEN LOWER TO IFR IN KTOP/KFOE BY 11Z.
AS THE LLVL FLOW VEERS THROUGH 15Z SOUTHERLY WINDS WILL VEER TO
THE SOUTHWEST AS CIGS RISE TO AROUND 2000 FT. AS COLD FRONT APPROACHES
THEN MOVES THROUGH AND DRIER AIR ADVECTS EASTWARD...SHOULD SEE VFR
CONDITIONS SPREAD WEST TO EAST ALL AREAS IN THE 18Z-20Z TIME
FRAME WITH WINDS SHIFTING TO THE NORTHWEST 12-20 KTS.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1245 AM EST MON DEC 3 2012
.SYNOPSIS...
WELL ABOVE NORMAL TEMPERATURES ARE EXPECTED THROUGH THE EARLY PART
OF THIS WEEK AS HIGH PRESSURE DRIFTS ACROSS THE AREA. A COLD FRONT
WILL CROSS THE EASTERN CAROLINAS ON WEDNESDAY AND MAY BRING A FEW
SHOWERS. NEAR TO SLIGHTLY BELOW NORMAL TEMPERATURES ARE EXPECTED
BEHIND THE COLD FRONT FOR LATE WEEK. UNSETTLED WEATHER MAY RETURN
NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 12:30 AM MONDAY...FOG OF VARYING THICKNESS AND EXTENT
FORMING WHEREVER THERE IS A BREAK IN THE CLOUDS EARLY THIS
MORNING. THIS IS MUCH AS EXPECTED. NO SUBSTANTIAL CHANGES TO THE
FORECAST WITH THE LATEST UPDATE. PREVIOUS DISCUSSIONS FOLLOW:
TEMPERATURES NEAR THE COAST HAVE FALLEN QUICKLY THIS EVENING AND
ALREADY ARE WITHIN A COUPLE DEGREES OF FORECAST LOWS. FARTHER
INLAND WHERE STRATOCUMULUS CLOUDS HAVE BEEN MORE PERVASIVE
TEMPERATURES ARE ACTUALLY A COUPLE DEGREES HIGHER THAN WAS
FORECAST FOR 02Z. STANDARD INFRARED SATELLITE IS NOT SHOWING MUCH
OF THE CLOUD COVER INLAND...HOWEVER THE 11-3.9 MICRON DIFFERENCE
IMAGERY IS SHOWING SCATTERED TO BROKEN STRATOCUMULUS EXTENDING
FROM FLORENCE NORTHEASTWARD ACROSS LUMBERTON AND ELIZABETHTOWN.
THIS IS AT LEAST 40-50 MILES FARTHER NORTH THAN WHERE THE 18Z
SYNOPTIC MODELS AND THE LATEST SEVERAL RUC RUNS INDICATED MAXIMUM
ISENTROPIC LIFT WOULD OCCUR. EARLIER SHOWER ACTIVITY HAS
DISSIPATED WITH STABILIZATION OF THE LOWER TROPOSPHERE...AND THERE
IS NO IMPETUS FOR ADDITIONAL SHOWER ACTIVITY THROUGH THE NIGHT.
WITH TEMPERATURE-DEWPOINT SPREADS AT THE SURFACE CLOSING UP TO ZERO
AT THE COAST...TEMPERATURE CURVES SHOULD FLATTEN OUT SHORTLY. ANY
STRATOCUMULUS ADVECTING EASTWARD FROM POINTS FARTHER INLAND COULD
ACTUALLY CAUSE A TEMPORARY RISE IN SURFACE TEMPERATURE. THE BIGGEST
QUESTION FOR THE REMAINDER OF THE NIGHT IS FOG. VISIBILITIES ARE
ALREADY DROPPING AT GEORGETOWN...CONWAY...AND IN NORTH MYRTLE BEACH.
FOG SHOULD BECOME MORE WIDESPREAD OVER THE NEXT SEVERAL HOURS...BUT
WILL AVOID AREAS WITH RESTRICTED RADIATIONAL COOLING FROM
SUBSTANTIAL CLOUD COVER. IF A DENSE FOG ADVISORY BECOMES NEEDED
OVERNIGHT THE MOST LIKELY LOCATIONS WOULD BE GEORGETOWN AND HORRY
COUNTIES IN SOUTH CAROLINA THROUGH COASTAL SOUTHEASTERN NORTH
CAROLINA. PREVIOUS DISCUSSION FROM 630 PM FOLLOWS...
TEMPERATURES AND DEWPOINTS WILL BOTH REMAIN ABOVE NORMAL FOR
DECEMBER AS A NEARLY-SUBTROPICAL AIRMASS IS LIFTED NORTH BY HIGH
PRESSURE LOCATED JUST OFFSHORE. ISOLATED SHOWERS JUST NORTH OF
FLORENCE ARE THE RESULT OF A POCKET OF INSTABILITY BETWEEN 850 AND
700 MB AIDED BY WEAK ISENTROPIC LIFT ALONG THE 295K ISENTROPIC
SURFACE. ALTHOUGH THE INSTABILITY IS FORECAST TO DISSIPATE THIS
EVENING...ISENTROPIC LIFT IS EXPECTED TO CONTINUE ALONG 295K THETA
WHICH SHOULD KEEP SCATTERED TO BROKEN STRATOCUMULUS CLOUDS IN
PLACE...ESPECIALLY FROM FLORENCE EAST ACROSS MYRTLE BEACH INTO
SOUTHPORT.
WITH SUCH RICH BOUNDARY LAYER MOISTURE UNDERNEATH THE ISENTROPIC
LIFT ALOFT...IT WILL NOT TAKE LONG FOR RELATIVE HUMIDITY DOWN HERE
AT THE SURFACE TO APPROACH 100 PERCENT. COOL SOIL TEMPERATURES WILL
AID THAT PROCESS AS WELL...AND I ANTICIPATE AREAS OF FOG TO DEVELOP
LATE THIS EVENING AND OVERNIGHT. IT REMAINS POSSIBLE SOME OF THIS
FOG COULD BECOME QUITE DENSE. LOWS TONIGHT SHOULD FALL TO WITHIN A
COUPLE DEGREES OF 50 AREA-WIDE...ABOUT 10 DEGREES ABOVE NORMAL.
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
AS OF 300 PM SUNDAY...INCREASINGLY DEEP 500MB LONGWAVE TROUGH
DEVELOPING ACROSS THE MIDDLE PART OF THE COUNTRY FORCES DOWNSTREAM
RIDGING ACROSS THE CAROLINAS...WITH 500MB HEIGHTS RISING ABOVE 580DM
MONDAY...AND ONLY A SLIGHT DECREASE ON TUESDAY. THIS COMBINED
WITH HIGH PRESSURE PERSISTING AT THE SURFACE CREATES WELL ABOVE
NORMAL TEMPS WITH AMPLE DECEMBER SUNSHINE THROUGH THE SHORT TERM.
SURFACE HIGH INITIALLY CENTERED NEARLY OVERHEAD WILL GRADUALLY SHIFT
EAST...BECOMING DISPLACED OFFSHORE ON TUESDAY. THIS MOVEMENT IS DUE
TO THE EASTWARD PROGRESSION OF THE UPPER TROUGH AND ASSOCIATED COLD
FRONT...WHICH WILL APPROACH FROM THE WEST AT THE END OF THE PERIOD.
WHILE HIGH SITS OVERHEAD MONDAY...WEAK RETURN FLOW WILL EXIST AT THE
SURFACE...BUT MID LEVEL FLOW WILL REMAIN W/NW. THIS IS A WARMING
/DOWNSLOPE/ TRAJECTORY...SO 850MB TEMPS AROUND 9C AND 1000-850MB
THICKNESSES OF 1370M WILL HELP DRIVE MAX TEMPS WELL INTO THE 70S
AWAY FROM THE IMMEDIATE BEACHES. AS HIGH DRIFTS OFFSHORE MONDAY
NIGHT...SOUTHERLY RETURN FLOW WILL CONTINUE...AND MINS WILL FALL
ONLY TO AROUND 50 DEGREES.
WHILE LOW LEVEL THICKNESSES REMAIN SIMILAR ON TUESDAY...INCREASED
HIGH LEVEL CLOUD COVER AHEAD OF THE COLD FRONT...GREATER LOW LEVEL
MOISTURE...AND SLIGHTLY REDUCED 500MB HEIGHTS WILL KEEP MAX TEMPS
MARGINALLY LOWER THAN ON MONDAY. STILL A VERY WARM AND DRY DAY
HOWEVER...WITH AFTN MAXIMUMS RISING INTO THE LOW 70S. PRESSURE
GRADIENT TIGHTENS AHEAD OF THE ADVANCING FRONT TUESDAY NIGHT...SO
WINDS STAY ELEVATED AND NIGHTTIME LOWS WILL FALL ONLY INTO THE LOW
50S.
ALTHOUGH FORECAST POP WILL REMAIN SILENT THROUGH THE
PERIOD...GUIDANCE IS PERSISTENT WITH SOME VERY LIGHT SHOWER ACTIVITY
EACH NIGHT. THIS IS LIKELY ASSOCIATED WITH MOIST ADVECTION BRINGING
SHOWERS ONSHORE...AND ALTHOUGH PROFILE MOISTURE IS CONFINED TO THE
LOWEST 5 KFT OR SO...SOME ISENTROPIC LIFT ALONG THE 295K SURFACE IS
EVIDENT EACH NIGHT. FEEL THE CHANCE FOR MEASURABLE PRECIP IS QUITE
LOW...SO WILL KEEP POP JUST BELOW THRESHOLD FOR NOW.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 300 PM SUNDAY...FORECAST CHALLENGE WILL COME LATER IN THE
PERIOD WHEN A BROAD CYCLONIC FLOW DEVELOPS ACROSS THE CENTRAL PART
OF THE CONUS WITH A SUBTLE SOUTHWEST FLOW ACROSS OUR CWA. AT THE
SURFACE...A FRONT WILL BE POSITIONED ACROSS THE
TENNESSEE/MISSISSIPPI VALLEY. WITH HPCS POSITION OF THE FRONT WELL
TO THE WEST...HAVE REMOVED POPS FROM THE FORECAST FOR THURSDAY
INTO FRIDAY ALTHOUGH RETURN FLOW COULD SPARK A FEW LIGHT SHOWERS
OFFSHORE. THE POSSIBILITY OF SEA FOG CANNOT BE RULED OUT WITH THIS
TYPE OF SCENARIO AS WELL. NO CHANGES TO TEMPERATURE FORECAST.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 06Z...EXPECT MVFR/IFR DUE TO FOG AND/OR LOW CIGS OVERNIGHT
INTO THE MORNING HOURS. OTHERWISE EXPECT VFR.
ALREADY THERE HAVE BEEN AREAS EXPERIENCING MVFR/IFR DUE TO FOG AND
LOW CIGS. EXPECT THIS PATTERN TO CONTINUE THROUGH THE OVERNIGHT
HOURS WITH LIGHT WINDS AND PARTLY TO MOSTLY CLOUDY SKIES. A TREND
WITH THE RESTRICTIONS WILL BE ITS VARIABILITY...VARYING FROM IFR TO
VFR...BACK TO MVFR IS AREAS. LATEST TIME HEIGHT AND FCST SOUNDING
ANALYSIS CONTINUE TO SUPPORT THESE CONDITIONS THROUGH THE MORNING
HOURS. FOR NOW...HAVE KEPT WITH CURRENT TREND OF PREVIOUS FORECAST
BY PROJECTING THE DETERIORATING WEATHER CONDITIONS DUE TO BOTH FOG
AND LOW CIGS. ATTM...EXPECT CONDITIONS TO IMPROVE TO MVFR AREA-WIDE
BY MID MORNING...PREVAILING AS VFR BY MID TO LATE MORNING. FOR THE
REST OF MONDAY EXPECT VFR WITH SCT MID LEVEL CLOUDS AND SOUTHWEST
WINDS 5-8 KTS...BECOMING LIGHT INTO MONDAY NIGHT.
EXTENDED OUTLOOK...MODERATE CONFIDENCE FOR MORNING MVFR/IFR FOG
THROUGH TUESDAY WITH A PERSISTENT MOIST LOW-LEVEL ONSHORE FLOW. A
SLIGHT CHANCE OF SHOWERS LATE TUESDAY INTO WEDNESDAY ASSOCIATED WITH
A COLD FRONT. OTHERWISE VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 12:30 AM MONDAY...MUCH AS BEFORE...NO ADDITIONAL SIGNIFICANT
CHANGES ARE NEEDED TO THE MARINE FORECAST EARLY THIS MORNING. SEAS
AT THE FRYING PAN SHOALS BUOY STILL AROUND 4 FT...WITH A LITTLE
MORE THAN HALF THAT MAKING IT TO THE BEACHES ACCORDING TO THE
WAVE GAUGE AT THE OCEAN CREST PIER ON OAK ISLAND. PREVIOUS FULL
DISCUSSION FROM 300 PM FOLLOWS...
AS HIGH PRESSURE REORIENTS ITSELF...WINDS WILL CONTINUE TO VEER FROM
E AND SE INTO THIS EVE...TO SW OVERNIGHT. WIND SPEEDS WILL BE 10 KT
OR LESS. SEAS WILL RANGE FROM 2 TO 3 FT. AN ESE 8 TO 9 SECOND SWELL
CONTINUES TO BE SAMPLED BY THE BUOYS AND NO CHANGES ARE EXPECTED
THIS PERIOD.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 300 PM SUNDAY...HIGH PRESSURE EXTENDING ACROSS THE WATERS
PERMITS ONLY LIGHT WINDS THROUGH THE PERIOD. WINDS WILL BE LIGHT AND
VARIABLE MONDAY AND MUCH OF TUESDAY...BEFORE VEERING TO THE SW AND
INCREASING TO AROUND 10 KTS TUESDAY NIGHT WELL AHEAD OF A COLD
FRONT. SEAS THEN ARE PRIMARILY SWELL DOMINATED...GENERATED FROM A
CONTINUING 3FT/8SEC SE GROUND SWELL...AND WILL BE 2-3 FT MONDAY.
SLIGHT ENHANCEMENT IN WAVE HEIGHTS EXPECTED LATE TUESDAY AS A 2-3FT
SW WIND WAVE DEVELOPS ON TOP OF THE PERSISTENT SWELL...BUT
SIGNIFICANT SEAS ARE STILL EXPECTED TO REMAIN 2-4 FT.
LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 300 PM SUNDAY...EXPECT A MODEST SOUTHWEST FLOW OF TEN KNOTS
OR SO AT THE BEGINNING OF THE PERIOD AHEAD OF A COLD FRONT TO THE
WEST. THE FRONT MOVES ACROSS THE WATERS WEDNESDAY AFTERNOON WITH A
NORTHERLY FLOW OF 10-15 KNOTS ENSUING. THE WINDS WILL REMAIN
ELEVATED RELATIVELY SPEAKING FOR MOST OF THE DAY THURSDAY IN A
10-15 KNOT RANGE WHILE VEERING TO THE NORTHEAST A BIT. FOR
FRIDAY...HIGH PRESSURE QUICKLY SLIPS OFFSHORE WITH A SOUTHEASTERLY
RETURN FLOW DEVELOPING. THE BIG STORY WITH SEAS WILL BE THE
POSSIBILITY OF SMALL CRAFT CONDITIONS THURSDAY AS THE NE FETCH
PERSISTS FOR QUITE SOME TIME. VALUES DROP BACK FRIDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JDW
NEAR TERM...REK/RJD
SHORT TERM...JDW
LONG TERM...SHK
AVIATION...SGL
MARINE...REK/RJD/JDW/SHK
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
204 AM EST MON DEC 3 2012
.SYNOPSIS...
A DIFFUSE FRONTAL BOUNDARY OVER CENTRAL PENNSYLVANIA TODAY WILL
PIVOT AND LIFT BACK TO THE NORTH AS A WARM FRONT TONIGHT. BROAD
SOUTHWEST FLOW WILL BRING UNSEASONABLY MILD AIR INTO THE REGION
THROUGH TUESDAY...WITH TEMPERATURES 10 TO 20 DEGREES ABOVE NORMAL.
A COLD FRONT WILL PUSH THROUGH THE REGION TUESDAY NIGHT ACCOMPANIED
BY A BAND OF RAIN SHOWERS. SEASONABLY COLD AND BRISK CONDITIONS
BEHIND THE FRONT WILL PREVAIL WEDNESDAY INTO THURSDAY...WITH SOME
LAKE EFFECT SNOW SHOWERS OVER THE NORTHWEST MOUNTAINS DOWNWIND OF
LAKE ERIE.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
WATER VAPOR LOOP SHOWS POTENT SHORTWAVE MOVING EASTWARD ACROSS
SOUTHERN QUEBEC AT 03Z. WANING LG SCALE FORCING BEHIND THIS
FEATURE HAS CAUSED SHOWERS TO DIMINISH ACROSS CENTRAL PA AND
LATEST RAP DATA AND RADAR TRENDS SUGGEST ANY REMAINING -SHRA OR
DRIZZLE AFTER MIDNIGHT WILL BE CONFINED MAINLY TO THE UPSLOPE
AREAS ALONG THE LAUREL HIGHLANDS.
SFC COLD FRONT...APPROACHING THE NORTHERN LK ERIE SHORE AT
03Z...WILL SAG INTO THE N MTNS LATE TONIGHT. OVERCAST SKIES AND A
SW BREEZE WILL KEEP IT VERY MILD OVERNIGHT WITH LOWS MOSTLY IN THE
M/U40S. PLENTY OF LOW LVL MOISTURE AND LGT WINDS WILL RESULT IN
AREAS OF FOG. SOME OF THE FOG COULD BECOME DENSE...ESP OVR THE W
MTNS...WHERE A LGT SW WIND ASCENDS THE HIGH TERRAIN.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TUESDAY/...
RIDGING AT THE SFC AND ALOFT SHOULD SUPPLY CENTRAL PA WITH DRY WX
ON MONDAY. HOWEVER...PLENTY OF LOW LVL MOISTURE WILL REMAIN
TRAPPED BENEATH SUBSIDENCE INVERSION...RESULTING IN A GOOD DEAL OF
CLOUD COVER...ESP ACROSS THE W MTNS WHERE A LIGHT W WIND ASCENDS
THE HIGH TERRAIN.
DESPITE THE CLOUD COVER...CENTRAL PA WILL BE ON THE EDGE OF AN
UNSEASONABLY WARM AIR MASS CENTERED OVR THE MIDWEST/OHIO VALLEY.
LATEST GUIDANCE CONTINUES TO SUGGEST TEMPS WILL REACH CLOSE TO
60F OVER MUCH OF CENTRAL PA MON AFTN.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
EXTENSIVE ZONAL UPPER FLOW ACROSS MUCH OF THE LOWER 48 IS
FORECAST TO CONTINUE THROUGH MUCH OF THE LONG TERM PERIOD. THIS
FLOW PATTERN WILL KEEP LARGE SCALE COLD WEATHER AT BAY...BUT SOME
VISITS FROM WINTRY WEATHER ARE NOT OUT OF THE QUESTION. SEVERAL
PIECES OF SHORTWAVE ENERGY MOVING THROUGH THE FLOW WILL LEAD TO
CHANCES FOR PCPN DURING THE WEEK AHEAD.
TUESDAY/S HIGHS WILL BE 18-20F ABOVE NORMAL...AND PERHAPS AS MUCH
AS 25F ABOVE NORMAL ACROSS LAUREL HIGHLANDS AND ADJACENT SOUTH-
CENTRAL VALLEYS AHEAD OF THE NEXT APPROACHING COLD FRONT.
THE POTENT SHORTWAVE CRASHING ONTO THE NW COAST TODAY /SUNDAY/ WILL
MOVE QUICKLY EAST ACROSS SOUTHERN CANADA AND AMPLIFY AS IT SLIDES
THROUGH ONTARIO PROVINCE DURING THE MIDWEEK PERIOD. THE ASSOCIATED
COLD FRONT WILL BRING A SEVERAL HOUR PERIOD OF RAIN SHOWERS TO THE
REGION LATE TUESDAY/TUESDAY NIGHT...WITH MOST MODEL GUIDANCE AND
ENSEMBLES INDICATING A MEAN QPF OF ABOUT 2-3 TENTHS.
THE SURGE OF MUCH COOLER AIR IN THE WAKE OF THE FRONT WILL SUPPORT
SCATTERED SNOW SHOWERS ACROSS MAINLY THE MTNS OF NWRN PENN LATE
TUESDAY NIGHT AND WEDNESDAY...WITH MINOR ACCUMULATIONS OF A COATING
TO AND INCH OR TWO POSSIBLE /NEAR AND TO THE WEST OF KBFD/.
ENSEMBLE MOS TEMPS STAY A FEW...TO SEVERAL DEG F ABOVE NORMAL FOR
THURSDAY AND FRIDAY AS UPPER HEIGHTS REBOUND ONLY SLIGHTLY...AND A
BUBBLE OF HIGH PRESSURE WITH CP AIR SLIDES SE FROM THE PRAIRIE
PROVINCES OF SCENT CANADA AND REACHES THE NE U.S. COAST THURSDAY
NIGHT.
UNCERTAINTY CLIMBS SIGNIFICANTLY FOR NEXT WEEKEND AS THE NEXT COLD
FRONTAL BOUNDARY SLOWS AND PERHAPS TEMPORARILY STALLS OUT FROM THE
OHIO VALLEY THROUGH THE MID ATLANTIC REGION. LARGE DIVERGENCE ARISES
IN THE QPF PATTERN/FRONTAL LOCATION BETWEEN 00Z/06Z GFS AND
EC...ALONG WITH A LARGE SPREAD IN GEFS /PLUME/ QPF AND SFC-925 MB
TEMPS.
RAIN CHANCES INCREASE BEGINNING LATE FRIDAY NIGHT THROUGH NEXT
WEEKEND...AND COULD POSSIBLY BE MIXED WITH SNOW ACROSS THE NW HALF
OF THE STATE.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
03/06Z - 04/06Z...
RESIDUAL LOW-LEVEL MSTR TRAPPED UNDER A WEAK AREA OF HIGH PRESSURE
WILL RESULT IN WDSPRD LOW CIGS...FOG AND PATCHY DZ EARLY TODAY.
JST SHOULD EXPERIENCE A PROLONGED PERIOD OF VLIFR CONDS...WHILE
OTHER SITES VARY BTWN LOW MVFR AND IFR CONDS. BLYR WARMING/MIXING
AND SHOULD BRING IMPROVING VISBYS BY THE AFTN...BUT LOW CIGS MAY
PERSIST ESP OVR WRN SXNS BASED ON FCST SOUNDING DATA. WINDS WILL
BACK MORE TO THE SOUTH BY THIS EVE. A DIFFUSE WARM FRONTAL ZONE
WILL PIVOT AND LIFT NWD TNT INTO EARLY TUES. SSELY FLOW
INTERSECTING THE FRONTAL ZONE MAY BRING LOW CIGS TO CNTRL AND ERN
SXNS LATE TNT.
OUTLOOK...
TUE...A SEASONABLY STRONG COLD FRONT WILL ENTER THE REGION LATE
IN THE DAY AND CROSS THE AREA OVERNIGHT. EXPECT MAINLY VFR TO
MVFR WITH RAIN SHOWERS. OCNL IFR VIS IN MOD RA. SW-NW WSHFT BY
WED AM.
WED...MVFR WEST WITH SNOW SHOWERS. GUSTY NNW WINDS.
THU-FRI...BCMG VFR WEST. NO SIG WX.
&&
.EQUIPMENT...
IPT OBSERVATION IS NOT BEING TRANSMITTED OR RECEIVED INTO OUR
SYSTEMS. THE PROBLEM IS RELATED TO A FAA COMMS LINE OUTAGE. WE
STILL HAVE DIAL- UP CAPABILITY.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...FITZGERALD/LA CORTE
SHORT TERM...FITZGERALD/LA CORTE
LONG TERM...LAMBERT/GARTNER
AVIATION...STEINBUGL
EQUIPMENT...STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1102 PM EST SUN DEC 2 2012
.SYNOPSIS...
A WEAKENING COLD FRONT WILL WASH OUT AS IT ENTERS NORTHERN PENNSYLVANIA
TONIGHT. HIGH PRESSURE WILL BUILD ALONG THE EAST COAST EARLY THIS
WEEK. A COLD FRONT WILL PUSH THROUGH THE REGION TUESDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
WATER VAPOR LOOP SHOWS POTENT SHORTWAVE MOVING EASTWARD ACROSS SOUTHERN
QUEBEC AT 03Z. WANING LG SCALE FORCING BEHIND THIS FEATURE HAS
CAUSED SHOWERS TO DIMINISH ACROSS CENTRAL PA AND LATEST RAP DATA
AND RADAR TRENDS SUGGEST ANY REMAINING -SHRA OR DRIZZLE AFTER
MIDNIGHT WILL BE CONFINED MAINLY TO THE UPSLOPE AREAS ALONG THE
LAUREL HIGHLANDS.
SFC COLD FRONT...APPROACHING THE NORTHERN LK ERIE SHORE AT
03Z...WILL SAG INTO THE N MTNS LATE TONIGHT. OVERCAST SKIES AND A
SW BREEZE WILL KEEP IT VERY MILD OVERNIGHT WITH LOWS MOSTLY IN THE
M/U40S. PLENTY OF LOW LVL MOISTURE AND LGT WINDS WILL RESULT IN
AREAS OF FOG. SOME OF THE FOG COULD BECOME DENSE...ESP OVR THE W
MTNS...WHERE A LGT SW WIND ASCENDS THE HIGH TERRAIN.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
RIDGING AT THE SFC AND ALOFT SHOULD SUPPLY CENTRAL PA WITH DRY WX
ON MONDAY. HOWEVER...PLENTY OF LOW LVL MOISTURE WILL REMAIN
TRAPPED BENEATH SUBSIDENCE INVERSION...RESULTING IN A GOOD DEAL OF
CLOUD COVER...ESP ACROSS THE W MTNS WHERE A LIGHT W WIND ASCENDS
THE HIGH TERRAIN.
DESPITE THE CLOUD COVER...CENTRAL PA WILL BE ON THE EDGE OF AN
UNSEASONABLY WARM AIR MASS CENTERED OVR THE MIDWEST/OHIO VALL.
LATEST GUIDANCE CONTINUES TO SUGGEST TEMPS WILL REACH CLOSE TO
60F OVER MUCH OF CENTRAL PA MON AFTN.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
EXTENSIVE ZONAL UPPER FLOW ACROSS MUCH OF THE LOWER 48 IS
FORECAST TO CONTINUE THROUGH MUCH OF THE LONG TERM PERIOD. THIS
FLOW PATTERN WILL KEEP LARGE SCALE COLD WEATHER AT BAY...BUT SOME
VISITS FROM WINTRY WEATHER ARE NOT OUT OF THE QUESTION. SEVERAL
PIECES OF SHORTWAVE ENERGY MOVING THROUGH THE FLOW WILL LEAD TO
CHANCES FOR PCPN DURING THE WEEK AHEAD.
TUESDAY/S HIGHS WILL BE 18-20F ABOVE NORMAL...AND PERHAPS AS MUCH
AS 25F ABOVE NORMAL ACROSS LAUREL HIGHLANDS AND ADJACENT SOUTH-
CENTRAL VALLEYS AHEAD OF THE NEXT APPROACHING COLD FRONT.
THE POTENT SHORTWAVE CRASHING ONTO THE NW COAST TODAY /SUNDAY/ WILL
MOVE QUICKLY EAST ACROSS SOUTHERN CANADA AND AMPLIFY AS IT SLIDES
THROUGH ONTARIO PROVINCE DURING THE MIDWEEK PERIOD. THE ASSOCIATED
COLD FRONT WILL BRING A SEVERAL HOUR PERIOD OF RAIN SHOWERS TO THE
REGION LATE TUESDAY/TUESDAY NIGHT...WITH MOST MODEL GUIDANCE AND
ENSEMBLES INDICATING A MEAN QPF OF ABOUT 2-3 TENTHS.
THE SURGE OF MUCH COOLER AIR IN THE WAKE OF THE FRONT WILL SUPPORT
SCATTERED SNOW SHOWERS ACROSS MAINLY THE MTNS OF NWRN PENN LATE
TUESDAY NIGHT AND WEDNESDAY...WITH MINOR ACCUMULATIONS OF A COATING
TO AND INCH OR TWO POSSIBLE /NEAR AND TO THE WEST OF KBFD/.
ENSEMBLE MOS TEMPS STAY A FEW...TO SEVERAL DEG F ABOVE NORMAL FOR
THURSDAY AND FRIDAY AS UPPER HEIGHTS REBOUND ONLY SLIGHTLY...AND A
BUBBLE OF HIGH PRESSURE WITH CP AIR SLIDES SE FROM THE PRAIRIE
PROVINCES OF SCENT CANADA AND REACHES THE NE U.S. COAST THURSDAY
NIGHT.
UNCERTAINTY CLIMBS SIGNIFICANTLY FOR NEXT WEEKEND AS THE NEXT COLD
FRONTAL BOUNDARY SLOWS AND PERHAPS TEMPORARILY STALLS OUT FROM THE
OHIO VALLEY THROUGH THE MID ATLANTIC REGION. LARGE DIVERGENCE ARISES
IN THE QPF PATTERN/FRONTAL LOCATION BETWEEN 00Z/06Z GFS AND
EC...ALONG WITH A LARGE SPREAD IN GEFS /PLUME/ QPF AND SFC-925 MB
TEMPS.
RAIN CHANCES INCREASE BEGINNING LATE FRIDAY NIGHT THROUGH NEXT
WEEKEND...AND COULD POSSIBLY BE MIXED WITH SNOW ACROSS THE NW HALF
OF THE STATE.
&&
.AVIATION /04Z MONDAY THROUGH FRIDAY/...
03Z TAF PACKAGE.
BEEN UPDATING TAFS.
MAINLY CLOUDY OVERNIGHT. LOOKING AT MAINLY IFR AND MVFR
CONDITIONS OVERNIGHT INTO MONDAY MORNING.
SOME IMPROVEMENT BY AFT...BUT HIGH HEIGHTS AND LOW SUN ANGLE
WILL LIKELY RESULT IN SC BEING TRAPPED.
WARM ADVECTION SETS LATE MONDAY INTO EARLY TUE...BEFORE A COLD
FRONT MOVES IN LATE TUE. MORE SHOWERS WITH THE COLD FRONT.
OUTLOOK...
TUE...A STRONG COLD FRONT WILL ENTER THE REGION LATE IN THE DAY
AND PASS OVERNIGHT. VFR TO MVFR WITH RAIN SHOWERS LATE. ISOLD
TSTMS PSBL. WIND-SHIFT BY WED AM.
WED...MVFR WEST WITH SNOW/RAIN SHOWERS.
THU/FRI...NO SIG WX.
&&
.EQUIPMENT...
IPT OBSERVATION NOT BEING TRANSMITTED OR RECEIVED INTO OUR SYSTEMS.
FAA IS AWARE AND WORKING THE ISSUE. WE STILL HAVE DIAL-UP CAPABILITY.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD/LA CORTE
NEAR TERM...FITZGERALD/LA CORTE
SHORT TERM...FITZGERALD/LA CORTE
LONG TERM...LAMBERT/GARTNER
AVIATION...LA CORTE/MARTIN
EQUIPMENT...LA CORTE
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
343 AM MST MON DEC 3 2012
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 342 AM MST MON DEC 3 2012
VIGOROUS COLD FRONT HAS BEEN PUSHING THROUGH THE NORTHERN AND
CENTRAL ZONES SINCE MIDNIGHT. AT 3 AM IT WAS INTO THE I-70
CORRIDOR AND PUSHING TO THE SE AT 25 MPH. SNOW LEVELS WERE QUICKLY
LOWERING TO AROUND 7KFT BEHIND THE FRONT. MOSBY MTN SNOTEL IN THE
EASTERN UINTA MTNS PICKED UP A QUICK 4 INCHES WITH THE FRONT THIS
EARLY MORNING. VALLEY GROUND TEMPERATURES THOUGH WERE VERY WARM SO
SNOW WAS STICKING MAINLY TO VEGETATION. THE 08Z RAP MODEL SHOWS THE
FRONT SHEARING AND WASHING OUT AS IT MOVES SOUTH OF I-70. SO THE
SOUTHERN VALLEYS WILL GET ONLY PIECEMEAL COOL ADVECTION THIS
MORNING. THE FAVORED MTNS INCLUDE THE PARK...FLATTOPS...THE
EASTERN PORTION OF THE GRAND MESA AND WESTERN PORTION OF THE ELKS.
THESE AREAS ARE STILL PROGGED TO GET 2-6 INCHES WITH LOCALIZED
HIGHER AMOUNTS IN CONVECTIVE SHOWERS.
SO THE FRONTAL PRECIPITATION WILL TAPER OFF QUICKLY THIS MORNING
LEAVING ONLY SCATTERED CONVECTIVE AFTERNOON SHOWERS IN ITS WAKE. A
DISTURBANCE PASSES THROUGH THE SOUTHERN CWA THIS AFTERNOON. SO
ENHANCED THE AFTERNOON POPS FOR THE SOUTHERN MTNS UNTIL SUNSET.
MAX TEMPERATURES FOR THE DAY MAY HAVE ALREADY BEEN REACHED FOR
SITES NORTH OF AND ALONG I-70.
A DRIER AIR MASS TONIGHT ALLOWS FOR MIN TEMPERATURES TO DROP TO
CLOSE TO NORMAL...EVEN BELOW NORMAL ACROSS THE NORTH.
TUESDAY...A BROAD RIDGE AXIS BUILDS IN FROM THE WEST. FLOW ALOFT
BACKS TO SW AND BOTH THE MTN AND VALLEY TEMPERATURES AGAIN CLIMB
TO WELL ABOVE NORMAL.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 342 AM MST MON DEC 3 2012
SHRTWV RIDGING TUESDAY WILL FLATTEN WITH NEAR ZONAL FLOW SETTING
UP WEDNESDAY THROUGH SATURDAY. DEEP PACIFIC MOISTURE AND EMBEDDED
WAVES OF ENERGY WILL BRING AN INCREASING CHANCE OF PRECIPITATION
TO THE REGION...ESPECIALLY WEDNESDAY NIGHT AND THURSDAY AS A
SLIGHTLY STRONGER PIECE OF ENERGY WORKS THROUGH. PLENTY OF
OROGRAPHICS WILL ALSO BE COMING INTO THE PLAY WITH THE WESTERLY
COMPONENT FAVORING MOUNTAINS ALONG THE DIVIDE AND MAINLY NORTH OF
INTERSTATE 70.
BY LATE IN THE WEEKEND...HEIGHTS CLIMB ACROSS THE EASTERN PACIFIC
WITH STRONG SURGE OF ENERGY DROPPING SOUTH OUT OF THE GULF OF
ALASKA. MEDIUM RANGE MODELS CONTINUE TO HINT AT A MAJOR COOL DOWN
FOR OUR AREA SUNDAY AND MONDAY WITH WIDESPREAD PRECIPITATION
BREAKING OUT AS ENERGY PINCHES OFF IN THE BASE OF THE DIGGING
TROUGH WITH A CLOSED LOW EVENTUALLY REACHING THE FOUR CORNERS.
THERE REMAINS SOME TIMING ISSUES AND GFS HAS STARTED TO SLOW THE
EVOLUTION DOWN A BIT...KEEPING CONFIDENCE AT A MINIMUM AT THIS
TIME.
WILL INCREASE POPS FROM INHERITED GRIDS AND LOWER TEMPS A BIT LATE
IN THE WEEKEND TO AT LEAST ADVERTISE THIS POSSIBLE CHANGE TO MORE
WINTER LIKE WEATHER.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 342 AM MST MON DEC 3 2012
THROUGH 15Z THIS MORNING...CIGS WILL BE BKN020-040 ACROSS THE
NORTH INCLUDING KVEL KHDN KSBS KASE KEGE WITH WIDESPREAD
-SHSN/-SHRA WITH SNOW LEVEL LOWERING TO 070. AREAS OF IFR FROM
PASSING SHOWERS ARE EXPECTED AS WELL AS MOUNTAIN OBSCURATIONS.
AFTER 15Z...EXPECT LIFTING CIGS THEN DISSIPATING AFTER 18Z. VFR
AT ALL TAF SITES AFTER 18Z THOUGH SCT SHSN WILL LINGER OVER HIGHER
TERRAIN THROUGH 00Z OBSCURING MTNS TOPS AT TIMES.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
SHORT TERM...JOE
LONG TERM...JDC
AVIATION...JOE
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
650 AM EST MON DEC 3 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 547 AM EST MON DEC 3 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A SHORTWAVE TROF EXTENDING
FROM SASKATCHEWAN TO CO. AT THE SFC...ASSOCIATED LOW PRES WAS OVER
FAR NE ND. ALTHOUGH SRLY FLOW AHEAD OF TROF TAPS THE GULF...00Z
RAOBS ACROSS THE PLAINS AND MID/UPPER MISSISSIPPI VALLEY SHOWED
CONSIDERABLE DRY AIR ABOVE SHALLOW SFC BASED MOISTURE. THIS HAS
IMPLICATIONS FOR PCPN FCST DUE TO UNCERTAINTY IN HOW QUICKLY
MOISTURE WILL DEEPEN THRU THE DAY PRIOR TO COLD FRONT ARRIVAL. AT
LEAST FOR THE FIRST PART OF TODAY...SEEMS LIKE ANY PCPN THAT
DEVELOPS WILL BE -DZ DUE TO SHALLOWNESS OF MOISTURE...AND FCST WILL
REFLECT THIS IDEA. MODELS ARE INSISTENT IN DEVELOPING DEEP ENOUGH
MOISTURE FOR SHRA TO BREAK OUT THIS AFTN ALONG/AHEAD OF APPROACHING
COLD FRONT. WITH BEST DEEP LAYER FORCING PASSING TO THE N...NOT
CONVINCED THIS WILL HAPPEN IN TIME BEFORE FRONT CROSSES THE AREA. IF
ANYTHING...IT SEEMS THERE WILL BE SOME DZ AROUND DURING THE DAY AND
THEN MAYBE A SCT/BKN BAND OF SHRA ALONG COLD FRONT. HAVE NUDGED POPS
DOWN A LITTLE...BUT STILL MAINTAINED A BRIEF PERIOD OF LIKELY POPS
OVER THE SCNTRL/E FCST AREA LATE THIS AFTN/EARLY EVENING.
AS ADVECTION OF HIGHER DWPTS CONTINUES TODAY...FOG WILL BE FAIRLY
WIDESPREAD...ESPECIALLY IN THE UPSLOPE AND HIGHER TERRAIN AREAS OF
CNTRL AND WRN UPPER MI. MAY SEE FOG BECOME LOCALLY DENSE THIS
MORNING. WILL MONITOR TRENDS DURING THE EARLY MORNING TO SEE IF
WIDESPREAD 1/4SM OR LESS DEVELOPS TO REQUIRE DENSE FOG ADVY.
ONCE COLD FRONT MOVES ACROSS UPPER MI LATE THIS AFTN AND EVENING...
CAA AND ADVECTION OF MUCH DRIER AIR WILL FINALLY WIPE PESKY STRATUS
AND FOG OUT THE AREA. ANY SHRA WILL END QUICKLY W TO E THIS EVENING
AND IN FACT...SKIES MAY BECOME MOSTLY CLEAR FOR THE OVERNIGHT. LATE
TONIGHT...LAKE AIDED CLOUDS MAY DEVELOP OVER NW UPPER MI IN
W FLOW AS 850MB TEMPS FALL TO -4 TO -8C OVER WRN LAKE SUPERIOR.
SINCE MODELS HAVE BEEN BACKING OFF ON DEGREE OF COOLING...DROPPED
MENTION OF LAKE EFFECT -SHSN ON THE KEWEENAW LATE...ESPECIALLY
CONSIDERING DRYNESS OF AIRMASS THRU THE OVERNIGHT HRS.
MAIN CONCERN TONIGHT WILL BE WINDS OVER THE KEWEENAW. CAA IS STRONG
(THOUGH OVERALL MODEL TREND HAS BEEN A LITTLE WEAKER IN RECENT RUNS)
AND THERE IS SOME HELP FROM THE ISALLOBARIC WIND. 850MB WINDS ARE
PROGGED AT 45-50KT AFTER FROPA...BUT IT APPEARS THAT LOW-LEVEL TEMP
PROFILE WILL NOT QUITE BE UNSTABLE ENOUGH TO FULLY TAP THE PERIOD OF
STRONGER WINDS ALOFT FOLLOWING FROPA. THIS MAY BE PART OF THE REASON
THAT THE MOST RECENT GFS/NAM RUNS HAVE LOWERED 950MB WIND SPEEDS
SLIGHTLY (NOW AROUND 35KT). ANOTHER NEGATIVE IS THAT INITIALLY WINDS
ARE LITTLE MORE WSW THAN THE IDEAL WNW DIRECTION FOR STRONG WINDS ON
THE KEWEENAW. ALSO OF NOTE IS THAT NAM/GFS MOS GUIDANCE FOR KCMX IS
ONLY 19-22KT TONIGHT. WILL PROBABLY SEE SOME GUSTS TO AROUND 45MPH
FOR A TIME ALONG THE WRN SHORE OF THE KEWEENAW DUE TO BETTER
OVERWATER INSTABILITY/COASTAL CONVERGENCE...BUT NOT SURE WIDESPREAD
WIND ADVY CRITERIA WILL BE ACHIEVED. FOR NOW...WILL HOLD OFF ON
ISSUANCE OF WIND ADVY.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 418 AM EST MON DEC 3 2012
BY DAYBREAK TUESDAY MUCH OF THE LOW LEVEL MOISTURE WITH THE INITIAL
COLD FRONT WILL BE OVER LOWER MI...WITH A RIBBON OF DRIER AIR SET UP
ACROSS UPPER MI. THIS WILL BE TEMPORARY AS A REINFORCING COLD FRONT
WRAPS IN DURING THE DAY...AND ANOTHER W-E ORIENTED TROUGH OVER
CENTRAL ONTARIO AT 12Z TUESDAY SLOWLY SINKS ACROSS UPPER MI TUESDAY
NIGHT. 850MB TEMPS WILL FALL FROM A CWA AVERAGE 0C AT DAYBREAK
TUESDAY...TO -6C AT 18Z...AND -12C BY 00Z WEDNESDAY /-15C OFF THE
LATEST NAM RUN/. WILL KEEP THE TREND OF SLOWLY FALLING TEMPS W-E
DURING THE DAY. THIS WILL HELP REMIND FOLKS THAT UNLIKE THE TEMPS WE
WILL HAVE TODAY...THAT IT IS INDEED DECEMBER. HOWEVER...EVEN WITH
HIGH TEMPS 10 TO 18F BELOW TODAY...THEY WILL STILL BE SLIGHTLY ABOVE
NORMAL FOR THIS TIME OF YEAR ACROSS CENTRAL AND E AREAS. ALTHOUGH
TEMPERATURES WILL BE A SHOCK FOR MOST...THE MAIN STORY TUESDAY WILL
BE THE STRONG W WINDS. THE STRONGEST WINDS GUSTING OUT OF THE WNW
BETWEEN 35 AND 45KTS WILL LINGER THROUGH MID MORNING...BEFORE SLOWLY
DIMINISHING DESPITE INCREASED MIXING ABOVE 850MB FROM MID AFTERNOON
ON. THE STRONGEST GUSTS WILL BE REALIZED OVER THE HIGHEST TERRAIN OF
THE KEWEENAW PENINSULA AND W FACING SLOPES NEAR LAKE SUPERIOR.
ALTHOUGH SNOW AMOUNTS WILL LIKELY BE LESS THAN 2 INCHES DURING THE
DAY...THE STRONG WINDS WILL RESULT IN BLOWING SNOW WILL REDUCED
VISIBILITIES. WILL KEEP THE MENTION OF STRONG WINDS AND REDUCED VIS
IN BLOWING SNOW IN THE HWO.
HIGH PRESSURE WILL SLOWLY SLIDE IN TUESDAY NIGHT...AND BE DIRECTLY
OVER HEAD WEDNESDAY. THE RESULT WILL BE A WEAKENING SFC TROUGH AND
DIMINISHING CLOUDS N WINDS OFF LAKE SUPERIOR BECOME LIGHT DURING THE
DAY AND WE BEGIN TO SEE A RETURN OF S WINDS OVER THE W HALF. 850MB
TEMPS WILL RISE SIGNIFICANTLY...FROM THE COOL VALUES AT 00Z
WEDNESDAY TO AN AVERAGE -2C BY 00Z THURSDAY...WITH INVERSION HEIGHTS
FALLING TO AROUND 900MB FOR MUCH OF THE DAY.
THE STRONG WAA WILL CONTINUE WEDNESDAY NIGHT THANKS TO THE INCREASED
PRESSURE GRADIENT BETWEEN THE EXITING STRONG HIGH OVER THE E GREAT
LAKES AND DEEPENING LOW OVER MANITOBA /WITH A SIZABLE TROUGH
EXTENDING THROUGH W TX/. A FEW 50KT WIND BARBS CONTINUE TO BE SHOWN
OVER THE W THIRD OF UPPER MI FROM AROUND 09Z THURSDAY ON. THE STRONG
WINDS WILL LIKELY BE SHORT LIVED...MAXING OUT RIGHT AROUND 12Z OVER
THE W HALF...AND THE E HALF AROUND 18Z. FOR 90-114HRS OUT...THE
03/00Z GFS AND 02/12Z ECMWF WERE IN PRETTY GOOD AGREEMENT ACROSS THE
UPPER GREAT LAKES WITH RESPECT TO THE COLD FRONT OVER W MN AT 12Z
THURSDAY SPLITTING UPPER MI NEARLY IN HALF BY 00Z FRIDAY. ALTHOUGH
THE ECMWF PAINTS AROUND 0.25IN OF LIQUID OVERHEAD THURSDAY INTO
THURSDAY EVENING ALONG AND AHEAD OF THE COLD FRONT...THE GFS HAS A
LIKELY MORE REALISTIC TENTH OF AN INCH OR LESS. GIVEN THE HIGH TEMPS
IN THE MID TO UPPER 30S AND SNOW GROWTH REGION AT OR ABOVE
600MB...PRECIP TYPE IS A CONCERN /ESPECIALLY OFF THE GFS WITH ITS
LESS THAN IMPRESSIVE MOISTURE/. WILL KEEP MIXED PRECIP IN FOR
THURSDAY INTO THURSDAY NIGHT.
COLD HIGH PRESSURE WILL SLOWLY BUILD IN FROM S CENTRAL CANADA AND
THE NORTHERN PLAINS FRIDAY THROUGH SATURDAY...AND BE DIRECTLY
OVERHEAD SUNDAY MORNING. W TO NW WINDS WILL DOMINATE DURING THIS
TIME PERIOD...WITH THE RETURN OF NEAR NORMAL TEMPERATURES /TOPPING
OUT NEAR 30F EACH AFTERNOON/. THE 03/00Z RUN OF THE GFS CONTINUES TO
GET EXCITED ABOUT WAA SWATH OF PRECIP SLIDING IN FROM THE SW AS THE
SFC LOW LINGERS ACROSS THE S PLAINS. RUN TO RUN CONSISTENCY WITHIN
THE GFS HAS SHOWN TO HAVE SOME ISSUES WITH THE PLACEMENT OF THIS
LOW...SO DO NOT HAVE THE HIGHEST CONFIDENCE IN OUR ONGOING FORECAST
FOR SATURDAY NIGHT ON.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 649 AM EST MON DEC 3 2012
WITH UPSLOPE SRLY FLOW AND ABUNDANT LOW LEVEL MOISTURE ACROSS THE
REGION...EXPECT MAINLY LIFR/IFR CIGS TO PERSIST THROUGH MOST OF
TODAY AT KSAW. IT`S QUITE POSSIBLE LIFR CONDITIONS MAY END UP BEING
THE PREVAILING CONDITION AT KSAW UNTIL COLD FROPA THIS EVENING.
DOWNSLOPE NATURE OF SRLY WIND HAS HELPED KIWD/KCMX STAY VFR OVER THE
LAST SEVERAL HRS. WHILE THAT COULD CONTINUE THRU THE MORNING...THE
CONTINUED INFLUX OF HIGHER DWPTS NORTHWARD WOULD ARGUE FOR STRATUS
EVENTUALLY SETTING IN AT KIWD/KCMX. WITH SHARPER DOWNSLOPING AT
KIWD...OPTED FOR JUST A LOW MVFR CIG DEVELOPING THERE WHILE KCMX
SHOULD TREND TO IFR. WHERE WINDS AREN`T GUSTING...LLWS WILL CONTINUE
TODAY. PASSAGE OF A COLD FRONT LATE AFTN/EVENING WILL BRING DRAMATIC
IMPROVEMENT TO VFR AS SUBSTANTIAL DRY/COLD ADVECTION CLEARS
STRATUS/FOG. CONDITIONS ARE FAVORABLE FOR STRONG W WINDS AFTER FROPA
AT KCMX. GUSTS AOA 35KT ARE POSSIBLE THERE TONIGHT.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 547 AM EST MON DEC 3 2012
AHEAD OF AN APPROACHING COLD FRONT...S WINDS WILL BE THE RULE TODAY
ACROSS LAKE SUPERIOR. AS IS OFTEN THE CASE WITH S WINDS...THE
STRONGEST WINDS (20-30KT) WILL BE OVER THE E HALF OF LAKE SUPERIOR.
ALTHOUGH WINDS AROUND 1000 FT OFF THE SFC WILL BE IN 40-45KT
RANGE...STABLE TEMP PROFILE WILL KEEP STRONGEST WINDS FROM REACHING
THE LAKE SFC. AT THE HIGHEST OBS PLATFORMS...WILL LIKELY SEE SOME
GALE FORCE GUSTS TO AROUND 35KT OR SO. COLD FRONT WILL CROSS LAKE
SUPERIOR LATE AFTN/EVENING. TIGHT PRES GRADIENT AND INFLUX OF COLDER
AIR THAT WILL ENHANCE MIXING OVER THE WATERS WILL RESULT IN W GALES
OF 35-40KT TONIGHT INTO TUE. APPROACHING HIGH PRES TUE NIGHT/WED WILL
BRING STEADILY DIMINISHING WINDS TO UNDER 15KT DURING THE DAY WED. S
WINDS WILL THEN BE ON THE INCREASE UP TO 30KT WED NIGHT INTO THU AS
PRES GRADIENT SHARPENS BETWEEN DEPARTING HIGH AND APPROACHING COLD
FRONT. EXPECT NW WINDS UP TO 25KT FRI BEHIND THIS NEXT COLD FROPA.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 1 AM TO 7 PM EST TUESDAY FOR LSZ266-267.
GALE WARNING FROM 9 PM EST /8 PM CST/ THIS EVENING TO 7 AM EST
/6 AM CST/ TUESDAY FOR LSZ162.
GALE WARNING FROM 9 PM THIS EVENING TO 4 PM EST TUESDAY FOR
LSZ243-244-264.
GALE WARNING FROM 9 PM THIS EVENING TO 1 PM EST TUESDAY FOR
LSZ242-263.
GALE WARNING FROM 1 AM TO 4 PM EST TUESDAY FOR LSZ245-265.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
547 AM EST MON DEC 3 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 547 AM EST MON DEC 3 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A SHORTWAVE TROF EXTENDING
FROM SASKATCHEWAN TO CO. AT THE SFC...ASSOCIATED LOW PRES WAS OVER
FAR NE ND. ALTHOUGH SRLY FLOW AHEAD OF TROF TAPS THE GULF...00Z
RAOBS ACROSS THE PLAINS AND MID/UPPER MISSISSIPPI VALLEY SHOWED
CONSIDERABLE DRY AIR ABOVE SHALLOW SFC BASED MOISTURE. THIS HAS
IMPLICATIONS FOR PCPN FCST DUE TO UNCERTAINTY IN HOW QUICKLY
MOISTURE WILL DEEPEN THRU THE DAY PRIOR TO COLD FRONT ARRIVAL. AT
LEAST FOR THE FIRST PART OF TODAY...SEEMS LIKE ANY PCPN THAT
DEVELOPS WILL BE -DZ DUE TO SHALLOWNESS OF MOISTURE...AND FCST WILL
REFLECT THIS IDEA. MODELS ARE INSISTENT IN DEVELOPING DEEP ENOUGH
MOISTURE FOR SHRA TO BREAK OUT THIS AFTN ALONG/AHEAD OF APPROACHING
COLD FRONT. WITH BEST DEEP LAYER FORCING PASSING TO THE N...NOT
CONVINCED THIS WILL HAPPEN IN TIME BEFORE FRONT CROSSES THE AREA. IF
ANYTHING...IT SEEMS THERE WILL BE SOME DZ AROUND DURING THE DAY AND
THEN MAYBE A SCT/BKN BAND OF SHRA ALONG COLD FRONT. HAVE NUDGED POPS
DOWN A LITTLE...BUT STILL MAINTAINED A BRIEF PERIOD OF LIKELY POPS
OVER THE SCNTRL/E FCST AREA LATE THIS AFTN/EARLY EVENING.
AS ADVECTION OF HIGHER DWPTS CONTINUES TODAY...FOG WILL BE FAIRLY
WIDESPREAD...ESPECIALLY IN THE UPSLOPE AND HIGHER TERRAIN AREAS OF
CNTRL AND WRN UPPER MI. MAY SEE FOG BECOME LOCALLY DENSE THIS
MORNING. WILL MONITOR TRENDS DURING THE EARLY MORNING TO SEE IF
WIDESPREAD 1/4SM OR LESS DEVELOPS TO REQUIRE DENSE FOG ADVY.
ONCE COLD FRONT MOVES ACROSS UPPER MI LATE THIS AFTN AND EVENING...
CAA AND ADVECTION OF MUCH DRIER AIR WILL FINALLY WIPE PESKY STRATUS
AND FOG OUT THE AREA. ANY SHRA WILL END QUICKLY W TO E THIS EVENING
AND IN FACT...SKIES MAY BECOME MOSTLY CLEAR FOR THE OVERNIGHT. LATE
TONIGHT...LAKE AIDED CLOUDS MAY DEVELOP OVER NW UPPER MI IN
W FLOW AS 850MB TEMPS FALL TO -4 TO -8C OVER WRN LAKE SUPERIOR.
SINCE MODELS HAVE BEEN BACKING OFF ON DEGREE OF COOLING...DROPPED
MENTION OF LAKE EFFECT -SHSN ON THE KEWEENAW LATE...ESPECIALLY
CONSIDERING DRYNESS OF AIRMASS THRU THE OVERNIGHT HRS.
MAIN CONCERN TONIGHT WILL BE WINDS OVER THE KEWEENAW. CAA IS STRONG
(THOUGH OVERALL MODEL TREND HAS BEEN A LITTLE WEAKER IN RECENT RUNS)
AND THERE IS SOME HELP FROM THE ISALLOBARIC WIND. 850MB WINDS ARE
PROGGED AT 45-50KT AFTER FROPA...BUT IT APPEARS THAT LOW-LEVEL TEMP
PROFILE WILL NOT QUITE BE UNSTABLE ENOUGH TO FULLY TAP THE PERIOD OF
STRONGER WINDS ALOFT FOLLOWING FROPA. THIS MAY BE PART OF THE REASON
THAT THE MOST RECENT GFS/NAM RUNS HAVE LOWERED 950MB WIND SPEEDS
SLIGHTLY (NOW AROUND 35KT). ANOTHER NEGATIVE IS THAT INITIALLY WINDS
ARE LITTLE MORE WSW THAN THE IDEAL WNW DIRECTION FOR STRONG WINDS ON
THE KEWEENAW. ALSO OF NOTE IS THAT NAM/GFS MOS GUIDANCE FOR KCMX IS
ONLY 19-22KT TONIGHT. WILL PROBABLY SEE SOME GUSTS TO AROUND 45MPH
FOR A TIME ALONG THE WRN SHORE OF THE KEWEENAW DUE TO BETTER
OVERWATER INSTABILITY/COASTAL CONVERGENCE...BUT NOT SURE WIDESPREAD
WIND ADVY CRITERIA WILL BE ACHIEVED. FOR NOW...WILL HOLD OFF ON
ISSUANCE OF WIND ADVY.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 418 AM EST MON DEC 3 2012
BY DAYBREAK TUESDAY MUCH OF THE LOW LEVEL MOISTURE WITH THE INITIAL
COLD FRONT WILL BE OVER LOWER MI...WITH A RIBBON OF DRIER AIR SET UP
ACROSS UPPER MI. THIS WILL BE TEMPORARY AS A REINFORCING COLD FRONT
WRAPS IN DURING THE DAY...AND ANOTHER W-E ORIENTED TROUGH OVER
CENTRAL ONTARIO AT 12Z TUESDAY SLOWLY SINKS ACROSS UPPER MI TUESDAY
NIGHT. 850MB TEMPS WILL FALL FROM A CWA AVERAGE 0C AT DAYBREAK
TUESDAY...TO -6C AT 18Z...AND -12C BY 00Z WEDNESDAY /-15C OFF THE
LATEST NAM RUN/. WILL KEEP THE TREND OF SLOWLY FALLING TEMPS W-E
DURING THE DAY. THIS WILL HELP REMIND FOLKS THAT UNLIKE THE TEMPS WE
WILL HAVE TODAY...THAT IT IS INDEED DECEMBER. HOWEVER...EVEN WITH
HIGH TEMPS 10 TO 18F BELOW TODAY...THEY WILL STILL BE SLIGHTLY ABOVE
NORMAL FOR THIS TIME OF YEAR ACROSS CENTRAL AND E AREAS. ALTHOUGH
TEMPERATURES WILL BE A SHOCK FOR MOST...THE MAIN STORY TUESDAY WILL
BE THE STRONG W WINDS. THE STRONGEST WINDS GUSTING OUT OF THE WNW
BETWEEN 35 AND 45KTS WILL LINGER THROUGH MID MORNING...BEFORE SLOWLY
DIMINISHING DESPITE INCREASED MIXING ABOVE 850MB FROM MID AFTERNOON
ON. THE STRONGEST GUSTS WILL BE REALIZED OVER THE HIGHEST TERRAIN OF
THE KEWEENAW PENINSULA AND W FACING SLOPES NEAR LAKE SUPERIOR.
ALTHOUGH SNOW AMOUNTS WILL LIKELY BE LESS THAN 2 INCHES DURING THE
DAY...THE STRONG WINDS WILL RESULT IN BLOWING SNOW WILL REDUCED
VISIBILITIES. WILL KEEP THE MENTION OF STRONG WINDS AND REDUCED VIS
IN BLOWING SNOW IN THE HWO.
HIGH PRESSURE WILL SLOWLY SLIDE IN TUESDAY NIGHT...AND BE DIRECTLY
OVER HEAD WEDNESDAY. THE RESULT WILL BE A WEAKENING SFC TROUGH AND
DIMINISHING CLOUDS N WINDS OFF LAKE SUPERIOR BECOME LIGHT DURING THE
DAY AND WE BEGIN TO SEE A RETURN OF S WINDS OVER THE W HALF. 850MB
TEMPS WILL RISE SIGNIFICANTLY...FROM THE COOL VALUES AT 00Z
WEDNESDAY TO AN AVERAGE -2C BY 00Z THURSDAY...WITH INVERSION HEIGHTS
FALLING TO AROUND 900MB FOR MUCH OF THE DAY.
THE STRONG WAA WILL CONTINUE WEDNESDAY NIGHT THANKS TO THE INCREASED
PRESSURE GRADIENT BETWEEN THE EXITING STRONG HIGH OVER THE E GREAT
LAKES AND DEEPENING LOW OVER MANITOBA /WITH A SIZABLE TROUGH
EXTENDING THROUGH W TX/. A FEW 50KT WIND BARBS CONTINUE TO BE SHOWN
OVER THE W THIRD OF UPPER MI FROM AROUND 09Z THURSDAY ON. THE STRONG
WINDS WILL LIKELY BE SHORT LIVED...MAXING OUT RIGHT AROUND 12Z OVER
THE W HALF...AND THE E HALF AROUND 18Z. FOR 90-114HRS OUT...THE
03/00Z GFS AND 02/12Z ECMWF WERE IN PRETTY GOOD AGREEMENT ACROSS THE
UPPER GREAT LAKES WITH RESPECT TO THE COLD FRONT OVER W MN AT 12Z
THURSDAY SPLITTING UPPER MI NEARLY IN HALF BY 00Z FRIDAY. ALTHOUGH
THE ECMWF PAINTS AROUND 0.25IN OF LIQUID OVERHEAD THURSDAY INTO
THURSDAY EVENING ALONG AND AHEAD OF THE COLD FRONT...THE GFS HAS A
LIKELY MORE REALISTIC TENTH OF AN INCH OR LESS. GIVEN THE HIGH TEMPS
IN THE MID TO UPPER 30S AND SNOW GROWTH REGION AT OR ABOVE
600MB...PRECIP TYPE IS A CONCERN /ESPECIALLY OFF THE GFS WITH ITS
LESS THAN IMPRESSIVE MOISTURE/. WILL KEEP MIXED PRECIP IN FOR
THURSDAY INTO THURSDAY NIGHT.
COLD HIGH PRESSURE WILL SLOWLY BUILD IN FROM S CENTRAL CANADA AND
THE NORTHERN PLAINS FRIDAY THROUGH SATURDAY...AND BE DIRECTLY
OVERHEAD SUNDAY MORNING. W TO NW WINDS WILL DOMINATE DURING THIS
TIME PERIOD...WITH THE RETURN OF NEAR NORMAL TEMPERATURES /TOPPING
OUT NEAR 30F EACH AFTERNOON/. THE 03/00Z RUN OF THE GFS CONTINUES TO
GET EXCITED ABOUT WAA SWATH OF PRECIP SLIDING IN FROM THE SW AS THE
SFC LOW LINGERS ACROSS THE S PLAINS. RUN TO RUN CONSISTENCY WITHIN
THE GFS HAS SHOWN TO HAVE SOME ISSUES WITH THE PLACEMENT OF THIS
LOW...SO DO NOT HAVE THE HIGHEST CONFIDENCE IN OUR ONGOING FORECAST
FOR SATURDAY NIGHT ON.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1206 AM EST MON DEC 3 2012
WITH SRLY FLOW AND PLENTIFUL LOW LEVEL MOISTURE ACROSS THE
REGION...EXPECT MAINLY IFR CIGS TO PERSIST THROUGH MOST OF TODAY.
HOWEVER...WITH DOWNSLOPE FLOW AND STRONGER MIXING DEVELOPING WITH A
STRENGTHENING LOW LEVEL JET...THE LOWER CIGS MAY LIFT FOR A TIME AT
IWD. SINCE CONFIDENCE IN LENGTH OF CLEARING AT IWD WAS LOW...KEPT
FCST WITH PREDOMINANT IFR. THE FOG MAY ALSO BECOME THICKER...
ESPECIALLY AT SAW...BUT THE LOW LEVEL MIXING SHOULD BE STRONG ENOUGH
TO MINIMIZE DENSE FOG CHANCES OR POTENTIAL FOR VLIFR CONDITIONS. AS
COLD FRONT MOVES THROUGH LATE AFTERNOON AND EVENING...SUBSTANTIAL
DRY/COLD ADVECTION WITH INCREASING INSTABILITY WILL BRING QUICK
IMPROVMENT TO AT LEAST MVFR.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 547 AM EST MON DEC 3 2012
AHEAD OF AN APPROACHING COLD FRONT...S WINDS WILL BE THE RULE TODAY
ACROSS LAKE SUPERIOR. AS IS OFTEN THE CASE WITH S WINDS...THE
STRONGEST WINDS (20-30KT) WILL BE OVER THE E HALF OF LAKE SUPERIOR.
ALTHOUGH WINDS AROUND 1000 FT OFF THE SFC WILL BE IN 40-45KT
RANGE...STABLE TEMP PROFILE WILL KEEP STRONGEST WINDS FROM REACHING
THE LAKE SFC. AT THE HIGHEST OBS PLATFORMS...WILL LIKELY SEE SOME
GALE FORCE GUSTS TO AROUND 35KT OR SO. COLD FRONT WILL CROSS LAKE
SUPERIOR LATE AFTN/EVENING. TIGHT PRES GRADIENT AND INFLUX OF COLDER
AIR THAT WILL ENHANCE MIXING OVER THE WATERS WILL RESULT IN W GALES
OF 35-40KT TONIGHT INTO TUE. APPROACHING HIGH PRES TUE NIGHT/WED WILL
BRING STEADILY DIMINISHING WINDS TO UNDER 15KT DURING THE DAY WED. S
WINDS WILL THEN BE ON THE INCREASE UP TO 30KT WED NIGHT INTO THU AS
PRES GRADIENT SHARPENS BETWEEN DEPARTING HIGH AND APPROACHING COLD
FRONT. EXPECT NW WINDS UP TO 25KT FRI BEHIND THIS NEXT COLD FROPA.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 1 AM TO 7 PM EST TUESDAY FOR LSZ266-267.
GALE WARNING FROM 9 PM EST /8 PM CST/ THIS EVENING TO 7 AM EST
/6 AM CST/ TUESDAY FOR LSZ162.
GALE WARNING FROM 9 PM THIS EVENING TO 4 PM EST TUESDAY FOR
LSZ243-244-264.
GALE WARNING FROM 9 PM THIS EVENING TO 1 PM EST TUESDAY FOR
LSZ242-263.
GALE WARNING FROM 1 AM TO 4 PM EST TUESDAY FOR LSZ245-265.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...JLB
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
545 AM CST MON DEC 3 2012
.DISCUSSION... /ISSUED 444 AM CST MON DEC 3 2012/
NEAR RECORD HIGH TEMPERATURES EXPECTED ACROSS THE MIDSOUTH
TODAY... COURTESY OF UNDER LOW AMPLITUDE RIDGING ALOFT AND
SOUTHERLY ONSHORE LOW LEVEL FLOW.
A POSITIVELY TILTED UPPER LEVEL TROF WILL LIFT INTO THE GREAT
LAKES... OHIO VALLEY AND LOWER MS RIVER VALLEY TUESDAY. AN ASSOCIATED
SURFACE COLD FRONT WILL DROP THROUGH THE MIDSOUTH ON TUESDAY...
PROVIDING FOCUS FOR SHOWERS AND ISOLATED THUNDERSTORMS. MIXED
LAYER CAPES TO 750 J/KG AND MODEST WIND SHEAR MAY SUPPORT A AN
EMBEDDED STRONG THUNDERSTORM OR TWO. NO SEVERE WEATHER IS ANTICIPATED.
A PACIFIC SURFACE HIGH WILL SETTLE INTO THE MIDSOUTH ON WEDNESDAY.
WITH A GOOD AMOUNT OF SUNSHINE...POST FRONTAL AFTERNOON TEMPS
WILL WARM TO READINGS 7 TO 10 DEGREES ABOVE NORMAL.
THURSDAY NIGHT SHOULD SEE A WARM FRONT LIFT NORTH THROUGH THE
MIDSOUTH... INCREASING SURFACE DEWPOINTS BACK INTO THE 50S BY FRIDAY
AFTERNOON. A 90KT 250MB JET STREAK MAY ENHANCE THE CHANCES FOR WARM
SECTOR SHOWERS ALONG AND NORTH OF THE ADVANCING WARM FRONT THURSDAY
NIGHT AND FRIDAY. BETTER FOCUS FOR RAIN LATE FRIDAY WILL OCCUR
OVER THE OHIO VALLEY...NEAR THE POSITION OF THE SURFACE WARM FRONT.
BOTH 00Z GFS AND ECMWF KEEP THE MIDSOUTH IN THE MILD...RELATIVELY
HUMID AND WELL MIXED GULF AIRMASS THROUGH SUNDAY. GFS MEX GUIDANCE
TEMPS AND DEWPOINTS APPEAR REASONABLE AND MAY EVEN BE CONSERVATIVELY
COOL.
SIMILAR TO THE PAST SEVERAL DAYS... ECMWF AND GFS MODELS CONTINUED
TO SHOW POOR AGREEMENT AND CONTINUED TO EXHIBIT GREATER THAN
NORMAL RUN TO RUN INCONSISTENCIES BEYOND 180 HOURS. OF PARTICULAR
NOTE IS THE MODELS/ HANDLING OF A RELATIVELY POTENT SOUTHERN
BRANCH UPPER LEVEL LOW LIFTING THROUGH THE SOUTHERN U.S. NEXT WEEK.
HAVE FOLLOWED A COMPROMISE BETWEEN THE MORE PROGRESSIVE ECMWF AND
SLOWER GFS WITH RESPECT TO THIS SYSTEM...LIFTING THROUGH LATE
MONDAY INTO TUESDAY. BOTH MODELS SUGGEST SOME SEVERE POTENTIAL
EXISTS WITH THIS SYSTEM...BUT IT REMAINS FAR TOO EARLY TO PIN DOWN
TIMING AND MAGNITUDE OF ANY SEVERE POTENTIAL.
PWB
&&
.AVIATION...
12Z TAF SET
IFR/MVFR CIGS CONTINUE TO DEVELOP OVER ARKANSAS AT THIS TIME.
LATEST RUC KEEPS CIGS WEST OF THE MS RIVER THUS HAVE KEPT KMEM VFR
THIS MORNING. KJBR SHOULD BE ONLY TAF SITE THAT EXPERIENCES IFR
CIGS BY 14-15Z THIS MORNING. CIGS WILL GRADUALLY LIFT AFTER
17-18Z. BY 19-21Z...VFR CONDITIONS SHOULD PREVAIL EVERYWHERE. MVFR
CIGS WILL BEGIN TO SPREAD INTO CWA AGAIN AFTER 06Z POSSIBLY LOWER
NEAR KJBR. KJBR COULD SEE A FEW TSRAS DEVELOP AHEAD OF APPROACHING
COLD FRONT AFTER 09Z. IN ADDITION...WOULD NOT BE SURPRISED TO SEE
A FEW ELEVATED TSRAS DEVELOP NEAR KTUP AFTER 8-9Z DUE TO WAA.
STRONG S WINDS EXPECTED AFTER 15Z. SPEEDS WILL INCREASE TO 12-17
KTS WITH HIGHER GUSTS. SPEEDS WILL DIE DOWN TO 8-10 KTS AFTER
00Z...POSSIBLY LOWER AT KTUP.
KRM
&&
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 75 62 69 43 / 0 30 90 10
MKL 74 58 67 41 / 0 20 90 10
JBR 74 59 65 40 / 10 70 80 0
TUP 74 56 71 47 / 0 0 80 60
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1009 AM MST MON DEC 3 2012
.UPDATE...
ISSUED AT 1009 AM MST MON DEC 3 2012
THE FRONT THAT MOVED THROUGH LAST NIGHT HAS WASHED OUT WITH PRECIP
ENDING OR CLOSE TO ENDING FOR MOST AREAS THIS MORNING. CDOT
WEBCAMS AND AREA WEBCAMS SHOW PLENTY OF SUN OVER THE PARK/GORE
RANGES AND ALSO THE ELKHEADS THOUGH SOME SNOW REMAINS NEAR VAIL
PASS. DROPPED POPS FOR THIS UPDATE TO REMOVE POPS FOR THOSE AREAS
WHILE KEEPING ISOLD SHOWERS ALONG THE CONTINENTAL DIVIDE.
POT VORT FIELDS CLEARLY SHOW A WEAK SHORTWAVE MOVING OVER THE
REGION THIS EVENING AND VIS SATELLITE IMAGERY IS PICKING UP ON
THIS WITH AN AREA OF CLOUDS CURRENTLY MOVING OVER EASTERN UTAH AND
HEADING OUR WAY. WHILE MODELS SHOW NO PRECIP FOR SAN JUANS...LIKE
THE IDEA THAT OROGRAPHICS AND FAVORABLE WIND FLOW WILL CAUSE SOME
VERY ISOLATED SNOW TO FALL MAINLY OVER THE HIGHEST TERRAIN.
ALSO INCREASED SKY COVER AS SHORTWAVE MOVES OVER REGION WITH
SCATTERED TO BROKEN SKIES EXPECTED THOUGH THEY SHOULD BE FAIRLY
HIGH.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 342 AM MST MON DEC 3 2012
VIGOROUS COLD FRONT HAS BEEN PUSHING THROUGH THE NORTHERN AND
CENTRAL ZONES SINCE MIDNIGHT. AT 3 AM IT WAS INTO THE I-70
CORRIDOR AND PUSHING TO THE SE AT 25 MPH. SNOW LEVELS WERE QUICKLY
LOWERING TO AROUND 7KFT BEHIND THE FRONT. MOSBY MTN SNOTEL IN THE
EASTERN UINTA MTNS PICKED UP A QUICK 4 INCHES WITH THE FRONT THIS
EARLY MORNING. VALLEY GROUND TEMPERATURES THOUGH WERE VERY WARM SO
SNOW WAS STICKING MAINLY TO VEGETATION. THE 08Z RAP MODEL SHOWS THE
FRONT SHEARING AND WASHING OUT AS IT MOVES SOUTH OF I-70. SO THE
SOUTHERN VALLEYS WILL GET ONLY PIECEMEAL COOL ADVECTION THIS
MORNING. THE FAVORED MTNS INCLUDE THE PARK...FLATTOPS...THE
EASTERN PORTION OF THE GRAND MESA AND WESTERN PORTION OF THE ELKS.
THESE AREAS ARE STILL PROGGED TO GET 2-6 INCHES WITH LOCALIZED
HIGHER AMOUNTS IN CONVECTIVE SHOWERS.
SO THE FRONTAL PRECIPITATION WILL TAPER OFF QUICKLY THIS MORNING
LEAVING ONLY SCATTERED CONVECTIVE AFTERNOON SHOWERS IN ITS WAKE. A
DISTURBANCE PASSES THROUGH THE SOUTHERN CWA THIS AFTERNOON. SO
ENHANCED THE AFTERNOON POPS FOR THE SOUTHERN MTNS UNTIL SUNSET.
MAX TEMPERATURES FOR THE DAY MAY HAVE ALREADY BEEN REACHED FOR
SITES NORTH OF AND ALONG I-70.
A DRIER AIR MASS TONIGHT ALLOWS FOR MIN TEMPERATURES TO DROP TO
CLOSE TO NORMAL...EVEN BELOW NORMAL ACROSS THE NORTH.
TUESDAY...A BROAD RIDGE AXIS BUILDS IN FROM THE WEST. FLOW ALOFT
BACKS TO SW AND BOTH THE MTN AND VALLEY TEMPERATURES AGAIN CLIMB
TO WELL ABOVE NORMAL.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 342 AM MST MON DEC 3 2012
SHRTWV RIDGING TUESDAY WILL FLATTEN WITH NEAR ZONAL FLOW SETTING
UP WEDNESDAY THROUGH SATURDAY. DEEP PACIFIC MOISTURE AND EMBEDDED
WAVES OF ENERGY WILL BRING AN INCREASING CHANCE OF PRECIPITATION
TO THE REGION...ESPECIALLY WEDNESDAY NIGHT AND THURSDAY AS A
SLIGHTLY STRONGER PIECE OF ENERGY WORKS THROUGH. PLENTY OF
OROGRAPHICS WILL ALSO BE COMING INTO THE PLAY WITH THE WESTERLY
COMPONENT FAVORING MOUNTAINS ALONG THE DIVIDE AND MAINLY NORTH OF
INTERSTATE 70.
BY LATE IN THE WEEKEND...HEIGHTS CLIMB ACROSS THE EASTERN PACIFIC
WITH STRONG SURGE OF ENERGY DROPPING SOUTH OUT OF THE GULF OF
ALASKA. MEDIUM RANGE MODELS CONTINUE TO HINT AT A MAJOR COOL DOWN
FOR OUR AREA SUNDAY AND MONDAY WITH WIDESPREAD PRECIPITATION
BREAKING OUT AS ENERGY PINCHES OFF IN THE BASE OF THE DIGGING
TROUGH WITH A CLOSED LOW EVENTUALLY REACHING THE FOUR CORNERS.
THERE REMAINS SOME TIMING ISSUES AND GFS HAS STARTED TO SLOW THE
EVOLUTION DOWN A BIT...KEEPING CONFIDENCE AT A MINIMUM AT THIS
TIME.
WILL INCREASE POPS FROM INHERITED GRIDS AND LOWER TEMPS A BIT LATE
IN THE WEEKEND TO AT LEAST ADVERTISE THIS POSSIBLE CHANGE TO MORE
WINTER LIKE WEATHER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z NOON TUESDAY)
ISSUED AT 1009 AM MST MON DEC 3 2012
SOME MVFR REMAINS FOR VARIOUS AIRPORTS ACROSS THE REGION BUT
EXPECT A RETURN TO VFR OVER THE NEXT FEW HOURS. A WEAK DISTURBANCE
WILL MOVE OVERHEAD THIS EVENING BRINGING MORE MID-LEVEL CLOUDS
WITH POSSIBLY SOME LGT PRECIP AND MOUNTAIN OBSCURATIONS FOR THE
SAN JUANS. ALL TAF SITES WILL REMAIN VFR.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
UPDATE...TGR
SHORT TERM...JOE
LONG TERM...JDC
AVIATION...TGR
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
308 PM CST MON DEC 3 2012
.SYNOPSIS...
A COLD FRONT WAS PUSHING INTO CENTRAL IOWA WITH SOUTHERLY WINDS
TRANSPORTING UNSEASONABLY WARM AND HUMID AIR INTO THE DVN CWA.
RECORD HIGHS HAVE ALREADY BEEN SET OR TIED FOR DECEMBER 3 AT ALL
MAJOR CLIMATE SITES. TEMPERATURES WERE ALSO NEARING THE ALL-TIME
RECORD HIGHS FOR DECEMBER. CURRENT READINGS WERE IN THE MID 60S TO
LOWER 70S WITH DEW POINTS AROUND 60. SPC MESO ANALYSIS INDICATED
SBCAPES WERE 500 J/KG AND EFFECTIVE BULK SHEAR WAS 45 KTS EAST OF
THE MS RIVER. EXTENSIVE LOW CLOUDS WERE OVER THE CWA BUT SOME
BREAKS NOTED ON VISIBLE SATELLITE PICTURES. ELSEWHERE BEHIND THE
FRONT TEMPERATURES WERE IN THE 50S WITH DEW POINTS IN THE
TEENS...ALONG WITH SUNNY SKIES.
HAASE
&&
.SHORT TERM...TONIGHT AND TUESDAY...
FORECAST FOCUS ON CONVECTIVE TRENDS LATE THIS AFTERNOON/EARLY THIS
EVENING WITH COLD FRONT.
TONIGHT...LOW CLOUDS PUTTING A DAMPER ON THE CONVECTIVE THREAT BUT
WILL STILL MENTION SHOWERS LIKELY AND ISOLATED THUNDERSTORMS FROM
MAINLY ABOUT THE MS RIVER ON EAST INTO THIS EVENING. HRRR MESO
MODEL SEEMS REASONABLE. THE COLD FRONT SHOULD BE NEAR THE MS RIVER
ABOUT 6 PM AND WILL HAVE MOVED THROUGH ALL OF THE CWA BEFORE
MIDNIGHT SO WILL BE DRY AFTER MIDNIGHT. SKIES WILL CLEAR LATER
TONIGHT AS SUBSIDENCE BEHIND UPPER TROUGH SWINGS THROUGH. WILL BE
COLDER WITH MIN TEMPS IN THE MID 30S NW TO MID 40S SE.
TUESDAY...HIGH PRESSURE BUILDS INTO THE CWA WITH SUNNY SKIES AND
COOLER TEMPERATURES...BUT STILL WELL ABOVE NORMAL FOR EARLY DECEMBER.
EXPECT AFTERNOON READINGS IN THE 50S ACROSS THE CWA.
HAASE
.LONG TERM...TUESDAY NIGHT THROUGH NEXT MONDAY...
ZONAL UPPER LEVEL FLOW TO CONTINUE THE WARMER THAN NORMAL
TEMPERATURES THROUGH THE WORKWEEK WITH PRECIPITATION CHANCES FOCUSED
ON A COLD FRONTAL PASSAGE THURSDAY. THE POTENTIAL FOR MUCH COLDER
TEMPERATURES AND POSSIBLE WINTRY PRECIPITATION IS STARTING TO LOOK
MORE LIKELY WITH THE ARRIVAL OF A MORE DYNAMIC PATTERN OVER THE
WEEKEND INTO EARLY NEXT WEEK.
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...HIGH PRESSURE DROPPING SOUTHEAST
OUT OF THE NORTHERN PLAINS WILL BRING A COLDER AIRMASS INTO THE
REGION TUESDAY NIGHT. CLEAR SKIES...LIGHT WINDS...AND 850 MB
TEMPERATURES IN THE LOW SINGLE DIGITS SUPPORT LOWS FROM THE MID 20S
NORTH TO LOWER 30S SOUTH. WEDNESDAY WILL REMAIN RELATIVELY COOL
COMPARED TO THE RECENT WARMTH AS LIGHT SOUTHEAST WINDS OUT OF THE
DEPARTING HIGH LIMIT HIGHS TO THE UPPER 30S NORTH TO NEAR 50 IN THE
FAR SOUTH. HIGH LEVEL CLOUD COVER WEDNESDAY WELL OUT AHEAD OF THE
NEXT FAST MOVING SHORTWAVE WILL HOLD MINS TO THE 30S.
THE FASTER ECMWF AND GEM TIMING OF THURSDAY EVENING/S COLD FRONTAL
PASSAGE IS PREFERRED OVER THE SLOWER GFS IN THE FAST FLOW ALOFT. MODELS
HAVE BACKED OFF SOME ON THE EXTENT OF PREFRONTAL PRECIPITATION...AND
HAVE FOLLOWED BY CONFINING LOW CHANCES FOR RAIN SHOWERS TO MAINLY
THE AFTERNOON HOURS ACROSS THE NORTHWEST. OTHERWISE...IT WILL BE
ANOTHER DAY OF BRISK SOUTHERLY WINDS...CLOUD COVER AND MILD
TEMPERATURES AHEAD OF THE FRONT WITH HIGHS FROM THE UPPER 40S TO
LOWER 50S. FOLLOWING THE FASTER NON-GFS SOLUTIONS...THE FRONT SHOULD
PUSH WELL SOUTHEAST BY FRIDAY MORNING...ALLOWING A DRY NORTH TO
NORTHEAST LOW LEVEL FLOW OUT OF THE NEXT HIGH DROPPING INTO THE
NORTHERN PLAINS. HOWEVER...DUE TO THE INPUT OF THE SLOWER...MORE
NORTHERLY GFS FRONTAL SOLUTION...SLIGHT CHANCE POPS ARE CARRIED INTO
THE FRIDAY PERIOD. TEMPERATURES WILL BE NOTICEABLY COOLER AS HIGHS
RETURN TO THE 40S.
SATURDAY THROUGH MONDAY...LATEST MODEL SOLUTIONS GENERALLY AGREE ON
AN EVOLUTION TO A MORE AMPLIFIED UPPER LEVEL FLOW AS A BUILDING
RIDGE IN THE EASTERN PACIFIC INDUCES A LONGWAVE TROUGH DOWNSTREAM IN
THE WESTERN U.S. THIS SETS UP AN UPPER LEVEL SOUTHWEST FLOW OVER A
STALLED FRONTAL BOUNDARY THROUGH THE MID MS VALLEY...FAVORABLE FOR
MORE WINTRY TYPE SYSTEMS OVER THE LOCAL AREA. HOWEVER...DUE TO HIGH
MODEL VARIABILITY FROM RUN TO RUN AND BETWEEN MODELS...CONFIDENCE IN
DETAILS IN THESE PERIODS REMAINS LOW. OVER THE PAST FEW RUNS...THE
ECMWF APPEARS TO HAVE THE BEST CONTINUITY WITH ITS MORE PHASED
DEPICTION OF THE LEAD SHORTWAVES THAT COULD RESULT IN THE REGION/S
FIRST WINTER STORM SYSTEM TRACKING FROM THE SOUTHERN PLAINS INTO THE
GREAT LAKES FROM SATURDAY NIGHT THROUGH SUNDAY NIGHT. THE 12Z GFS
HAS A SIMILAR SURFACE LOW...ALTHOUGH HAS A SLIGHTLY FASTER AND MORE
NORTHERLY TRACK. FOR NOW...THE BLENDED MODEL APPROACH WILL KEEP AN
EXTENDED PERIOD OF SLIGHT TO LOW END CHANCE POPS FROM FRIDAY NIGHT
THROUGH MONDAY...WHICH WILL LIKELY BE NARROWED DOWN IN LATER
FORECASTS. ABOVE NORMAL TEMPERATURES ADVERTISED THROUGH THE WEEKEND
COULD END UP SEVERAL CATEGORIES TOO HIGH...ESPECIALLY FROM SUNDAY
INTO MONDAY.
SHEETS
&&
.AVIATION...
VFR CONDS REMAINDER OF THIS AFTERNOON THROUGH TUESDAY. A COLD
FRONT WILL MOVE THROUGH THE REGION AND SHOULD BE NEAR THE
MISSISSIPPI RIVER BY 6 PM. ISOLATED THUNDERSTORMS ARE EXPECTED TO
DEVELOP AHEAD OF THE FRONT WITH THE BEST CHANCE NEAR AND EAST OF
THE MISSISSIPPI LATE THIS AFTERNOON AND EARLY THIS EVENING. WINDS
WILL SHIFT TO THE NORTHWEST BEHIND THE FRONT AND WILL BE GUSTY
THROUGH THE EVENING HOURS. SKIES WILL CLEAR AND WINDS WILL
DIMINISH AFTER MIDNIGHT. HIGH PRESSURE WILL BRING SKC ON TUESDAY
WITH NORTHWEST WINDS AROUND 10 KNOTS.
HAASE
&&
.CLIMATE...
RECORD HIGHS FOR DECEMBER 3...
MOLINE.........69 IN 1970
CEDAR RAPIDS...64 IN 1998
DUBUQUE........64 IN 1970
BURLINGTON.....71 IN 1970
MONTHLY RECORD HIGHS...
BURLINGTON.....73 12/04/1998
CEDAR RAPIDS...69 12/04/1998
DUBUQUE........67 12/04/1998, 24/1889
MOLINE.........71 12/04/1998
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
HAASE/SHEETS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1138 AM MST MON DEC 3 2012
.UPDATE...
ISSUED AT 1137 AM MST MON DEC 3 2012
WILL LET THE WIND ADVISORY EXPIRE ON SCHEDULE AT 19Z. SURFACE
WINDS ALONG THE COLORADO/KANSAS BORDER MAY CONTINUE TO BRIEFLY
REACH ADVISORY CRITERIA FOR A FEW MORE HOURS...BUT RECENT VAD WIND
PROFILE SHOWS A 10 KNOT DECREASE OF WINDS. RUC ALSO SUPPORTS A
GRADUAL DECREASE OF WINDS AS SURFACE HIGH MOVES ACROSS WESTERN
NEBRASKA.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 330 AM MST MON DEC 3 2012
UPPER FLOW WILL BE WESTERLY AHEAD OF A RIDGE MOVING INTO THE ROCKIES
TUESDAY NIGHT. WESTERLY FLOW WILL RESUME WEDNESDAY NIGHT AS THE
RIDGE SHIFTS EAST INTO THE GREAT LAKES REGION. A SURFACE HIGH WILL
MOVE INTO THE CENTRAL PLAINS TODAY AND CONTINUE THROUGH TUESDAY. A
TROUGH WILL MOVE INTO EASTERN COLORADO TUESDAY NIGHT AND CONTINUE
THROUGH WEDNESDAY NIGHT.
SUBSIDENCE AND LACK OF MOISTURE WILL KEEP DRY CONDITIONS ONGOING
THROUGH WEDNESDAY NIGHT. POPS WILL BE NIL FROM TODAY THROUGH
WEDNESDAY NIGHT.
THE MAIN CONCERN WITH THIS PART OF THE FORECAST ARE WINDS FOR THIS
MORNING. NORTH WINDS MAY REACH ADVISORY LEVEL FOR A FEW HOURS BEFORE
NOON. SUSTAINED WIND COULD RANGE FROM 30 TO 35 MPH WITH GUSTS TO
45 MPH ACROSS EASTERN COLORADO AND THE FIRST TWO TIERS OF COUNTIES
IN NORTHWEST KANSAS/SOUTHWEST NEBRASKA. MODELS INDICATE THAT THE
WIND WILL DROP OFF RATHER QUICKLY. BASED ON UPSTREAM METARS AM
CONCERNED THAT WIND GUSTS WILL REACH WIND ADVISORY CRITERIA OF 45
MPH AND SO FOR THIS REASON WILL ISSUE A WIND ADVISORY EVEN THOUGH
IT MAY BE SHORT-LIVED. (SEE DETAILS BELOW).
MAX TEMPERATURES WILL BE COOLER TODAY BEHIND THE FRONT WITH READINGS
IN THE MID 50S ACROSS THE WESTERN FA AND LOWER 60S EAST. MAX
TEMPERATURES WILL RISE TO NEAR 60 TUESDAY AND THE MID 60S WEDNESDAY.
MIN TEMPERATURES WILL COOL TO THE MID 20S TONIGHT AND THEN MODERATE
TO THE LOWER AND MID 30S TUESDAY/WEDNESDAY NIGHTS.
.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 330 AM MST MON DEC 3 2012
FOCUS IN THE LONG TERM IS THE POSSIBILITY OF PRECIPITATION LATE IN
THE PERIOD.
A SHORT WAVE TROUGH IN THE UPPER ZONAL FLOW MOVES ACROSS THE CENTRAL
HIGH PLAINS REGION ON THURSDAY. ADDITIONAL IMPULSES MOVE THROUGH
THE UPPER FLOW AND ACROSS THE CENTRAL HIGH PLAINS REGION FRIDAY
NIGHT AND SATURDAY NIGHT AS THE UPPER FLOW BECOMES INCREASINGLY SW
AHEAD OF A LARGER SCALE TROUGH DEEPENING OVER THE FAR WESTERN
UNITED STATES SATURDAY AND SATURDAY NIGHT. BY SUNDAY THE GFS AND
ECMWF HAVE BECOME FURTHER APART IN TIMING THE TROUGH OVER AND EAST
OF THE ROCKIES. WITH A TENDENCY TOWARDS A SLOWER SOLUTION AS STORM
SYSTEMS MOVE FROM THE LONG TERM INTO THE SHORT TERM...WILL HOLD OFF
ON INTRODUCING ANY PRECIPITATION IN THE EXTENDED PERIOD AND WILL
KEEP THE ENTIRE EXTENDED PERIOD DRY. EXPECT A COLD FRONT TO MOVE
THROUGH THE REGION EARLY THURSDAY MORNING. HIGH TEMPERATURES ON
THURSDAY WILL BE ABOUT 10 DEGREES COOLER THAN WEDNESDAY. WITH THE
JET BEGINNING TO SAG FURTHER SOUTH...EXPECT TEMPERATURES TO REMAIN
COOLER...BUT STILL WARMER THAN AVERAGE FOR THIS TIME OF
YEAR...THROUGH THE REMAINDER OF THE WEEK AND INTO THE WEEKEND.
EXPECT THE NEXT BEST CHANCE OF PRECIPITATION AND COLDER TEMPERATURES
ACROSS THE REGION TO COME EARLY NEXT WEEK AS THE LARGER UPPER TROUGH
MOVES EAST OF THE ROCKIES AND ACROSS THE PLAINS STATES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1039 AM MST MON DEC 3 2012
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD AT BOTH GLD AND
MCK. BREEZY NORTH WINDS GUSTING TO NEAR 40KTS ARE PRESENT THIS
AFTERNOON BEHIND A COLD FRONT WHICH MOVED THROUGH EARLIER THIS
MORNING. WINDS WILL DECREASE THROUGHOUT THE REST OF THE DAY AND
SKIES WILL BE MOSTLY SUNNY WITH JUST A FEW HIGH CIRRUS. OVERNIGHT
EXPECT LIGHT AND VARIABLE WINDS AS HIGH PRESSURE BUILDS ACROSS THE
TRI- STATE REGION...WITH A FEW MID-LEVEL CLOUDS MOVING ACROSS GLD
LATE TONIGHT INTO TUESDAY MORNING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...MENTZER
SHORT TERM...032
LONG TERM...LOCKHART
AVIATION...JJM
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1222 PM CST MON DEC 3 2012
.UPDATE...LOW LEVEL PRESSURE RISES AND THE RESULTANT INCREASING
LOW LEVEL PRESSURE GRADIENT CONTINUES TO PROMOTE STRONG WINDS
ACROSS THE AREA. SUSTAINED WINDS ACROSS THE AREA HAVE GENERALLY
BEEN IN THE 20-25KT RANGE SINCE 17Z. THAT BEING SAID...A FEW
SITES...PRIMARILY ALONG THE I-80 CORRIDOR...HAVE PERIODICALLY
CREPT UP INTO THE 26-30KT RANGE. THESE REPORTS HAVE BEEN FLEETING
HOWEVER AND AS OF 1815Z ONLY ONE SITE ACROSS THE CWA IS HITTING
WIND ADVISORY CRITERIA. SHORT TERM GUIDANCE PER THE RAP CONTINUES
TO SUGGEST THE STRONGEST LOW LEVEL PRESSURE GRADIENT WILL CONTINUE
MOVING EAST THROUGH THE NEXT FEW HOURS...THUS RESULTING IN A
DECREASING LOW LEVEL WIND FIELD THROUGH THIS AFTERNOON. THIS
GUIDANCE IS SUPPORTED BY OBSERVATION SITES UPSTREAM...WHICH ARE
GENERALLY SUSTAINED IN THE 15-20KT RANGE. ALL OF THIS INFORMATION
WOULD SUGGEST THE LOW LEVEL WIND FIELD ACROSS OUR CWA WILL DISPLAY
A MARKED DECREASE IN INTENSITY THROUGH THE NEXT 2-3 HOURS...WITH
THE STRONGEST WINDS LIKELY BEING OBSERVED NOW IF THEY HAVENT
ALREADY. GIVEN ALL THIS...WILL CONTINUE TO HOLD OFF FROM ANY
HEADLINE ISSUANCE AND CONTINUE TO MONITOR.
WENT AHEAD AND TWEAKED HOURLY SKY...TEMPERATURE AND DEWPOINT GRIDS
TO BETTER REFLECT CURRENT CONDITIONS. THESE CHANGES WERE VERY
MINOR HOWEVER AS THE OVERALL FORECAST REMAINS IN GREAT SHAPE AT
THIS TIME.
&&
.PREV DISCUSSION... /ISSUED 1112 AM CST MON DEC 3 2012/
AVIATION...18Z KGRI TAF. VFR CONDITIONS TO CONTINUE THROUGH THE
NEXT 24 HOURS. THE SURFACE WIND WILL REMAIN STRONG THROUGH
23Z...SUSTAINED AT 25KTS AND GUSTING AROUND 35KTS. THE SURFACE
WIND WILL THEN WEAKEN SIGNIFICANTLY AFTER 23Z. A FEW HIGH CLOUDS
WILL BE POSSIBLE DURING THE TAF PERIOD AND VISIBILITY RESTRICTIONS
ARE NOT EXPECTED THROUGH THE NEXT 24 HOURS.
PREV DISCUSSION... /ISSUED 954 AM CST MON DEC 3 2012/
UPDATE...MORNING UPPER AIR ANALYSIS INDICATES AN UPPER LEVEL
TROUGH EXTENDING FROM SOUTH CENTRAL CANADA INTO THE NORTHERN HIGH
PLAINS. RIDGING EXISTS OVER THE EASTERN HALF OF THE CONUS WITH
QUASI-ZONAL OVER MUCH OF THE WEST. MID AND UPPER LEVEL JET ENERGY
EXTENDS FROM NORTHERN CALIFORNIA...EAST/NORTHEAST INTO THE
NORTHERN PLAINS AND SOUTH CENTRAL CANADA...AND THEN EAST/SOUTHEAST
INTO SOUTHEASTERN CANADA AND THE NORTHEASTERN CONUS. MUCH OF THIS
JET ENERGY REMAINS WEST/NORTHWEST OF OUR AREA AND AS A
RESULT...TROPOSPHERIC FLOW OVER OUR AREA REMAINS FAIRLY
WEAK...MAXING OUT AT AROUND 90KTS NEAR 150MB PER 12Z SOUNDING DATA
FROM KLBF. WATER VAPOR IMAGERY INDICATES A MID LEVEL LOW OVER
SOUTHERN SASKATCHEWAN...EMBEDDED WITHIN THE UPPER LEVEL LONGWAVE
TROUGH. INCREASED VALUES OF MID LEVEL MOISTURE ARE ALSO NOTED
AHEAD OF THE MID LEVEL LOW AND UPPER LEVEL LONGWAVE
TROUGH...EXTENDING FROM THE CENTRAL PLAINS NORTHEAST INTO SOUTH
CENTRAL CANADA. AT THE SURFACE AN AREA OF LOW PRESSURE IS NOTED
OVER SOUTHERN MANITOBA...WITH AN ASSOCIATED COLD FRONT EXTENDING
SOUTH/SOUTHWEST FORM THE LOW. AS OF 14Z THIS FRONT WAS NOTED
EXTENDING FROM NEAR KOFK...TO NEAR KAUH...TO NEAR KHYS. THE LOW
LEVEL WIND FIELD REMAINS LIGHT AND VARIABLE FOR LOCATIONS ACROSS
OUR CWA STILL AHEAD OF THE LOW LEVEL BAROCLINIC ZONE. FOR
LOCATIONS FARTHER WEST/NORTHWEST HOWEVER...THE LOW LEVEL WIND
FIELD HAS TURNED WEST/NORTHWEST AND IS INCREASING IN INTENSITY.
POOLING OF LOW LEVEL MOISTURE...WORKING IN CONCERT WITH THE LIGHT
LOW LEVEL WIND FIELD...PROMOTED FOG ACROSS EASTERN PORTIONS OF THE
CWA EARLIER THIS MORNING. WITH FROPA BEING COMPLETE ACROSS MUCH OF
THE CWA HOWEVER...A MUCH DRIER LOW LEVEL AIRMASS AND A STRONG LOW
LEVEL WIND FIELD IS WORKING TO DIMINISH THE FOG. THE VISIBILITY
HAS CLIMBED WELL ABOVE 1/4SM FOR MOST LOCATIONS ACROSS THE
CWA...WITH THE ONLY EXCEPTION BEING KK61 AS OF 15Z...BUT THIS
RESTRICTION IN VISIBILITY IS NOT EXPECTED TO PERSIST FOR MORE THAN
AN HOUR AS THE LOW LEVEL BAROCLINIC ZONE CLEARS THE AREA. THE
DENSE FOG ADVISORY WAS ALLOWED TO EXPIRE AT 9 AM AS A RESULT.
LOW LEVEL PRESSURE RISES POST-FROPA ARE WORKING TO INCREASE THE
LOW LEVEL PRESSURE GRADIENT ACROSS WESTERN NEBRASKA AT THIS
HOUR...WITH STRONG NORTHWEST WINDS ALREADY NOTED AT KLBF AND KBBW
AS OF 15Z. THIS INCREASING LOW LEVEL PRESSURE GRADIENT...AND
RESULTANT STRONGER WINDS...ARE EXPECTED TO OVERTAKE OUR CWA
THROUGH THE REST OF THIS MORNING. IN ADDITION TO THE INCREASING
LOW LEVEL PRESSURE GRADIENT...AFTERNOON BOUNDARY LAYER MIXING TO
AROUND 800MB SHOULD TAP INTO WINDS OF AROUND 30KTS. GIVEN ALL
THIS...WINDY CONDITIONS WILL CERTAINLY BE OBSERVED ACROSS THE
ENTIRE CWA TODAY. MAV GUIDANCE DOES SUGGEST KEAR...KGRI AND KHSI
WILL HIT WIND ADVISORY CRITERIA FOR A TIME AROUND 18Z...HOWEVER
THIS IS EXPECTED TO BE VERY SHORT-LIVED AS THE STRONGEST LOW LEVEL
PRESSURE GRADIENT QUICKLY PUSHES OFF TO THE EAST. SEEING AS HOW
ANY WINDS THAT ARE STRONG ENOUGH TO MEET WIND ADVISORY CRITERIA
SHOULD BE VERY BRIEF...WILL HOLD OFF FROM WIND ADVISORY ISSUANCE
AT THIS TIME AND CONTINUE TO MONITOR.
PREV DISCUSSION... /ISSUED 618 AM CST MON DEC 3 2012/
UPDATE...VISIBILITIES HAVE DROPPED TO ONE QUARTER MILE IN FOG
ACROSS OUR EASTERN ZONES ALONG TROUGH AXIS/LIGHT WINDS AHEAD OF
FRONT. DUE TO THE LOW VISIBILITIES HAVE ISSUED A DENSE FOG
ADVISORY FOR A FEW HOURS THIS MORNING UNTIL FRONT MOVES THROUGH
AND SCOURS THE LLVL MOISTURE AND MIXING INCREASES.
PREV DISCUSSION... /ISSUED 355 AM CST MON DEC 3 2012/
SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT. PRIMARY FORECAST
CONCERNS LIE WITH TEMPERATURES AND WINDS.
QUIET CONDITIONS ARE IN PLACE ACROSS THE CWA EARLY THIS
MORNING...WITH UPPER AIR PROFILER AND SATELLITE DATA SHOWING
SOUTHWESTERLY FLOW OVER THE REGION AHEAD OF A TROUGH GRADUALLY
MAKING ITS WAY OUT OF THE ROCKIES AND ONTO THE PLAINS...ASSOCIATED
WITH AN AREA OF LOW PRESSURE OVER SRN SASKATCHEWAN. AT THE
SURFACE...CONTINUING TO SEE LIGHT SOUTHERLY FLOW ACROSS THE
CWA...WITH THE MAIN TROUGH AXIS AND COLD FRONT STILL OFF TO THE
WEST OF THE CWA. SKIES TO THIS POINT HAD BEEN MOSTLY CLEAR...BUT
EXPANSIVE AREA OF MID/UPPER LEVEL CLOUDS ARE NOW MAKING THEIR WAY
INTO WRN PORTIONS OF THE CWA.
LOOKING AT THE REST OF TODAY...THE FORECAST REMAINS DRY WITH
MODELS IN GOOD AGREEMENT KEEPING BETTER PRECIPITATION CHANCES N/NW
OF THE CWA. WILL KEEP THE MENTION OF SOME FOG IN FOR JUST THIS
MORNING...IN THE SAME AREA AS INHERITED /ERN TIER/...CONTINUES TO
BE SOME MODELS DEPICTING SOME DEVELOPMENT JUST AHEAD OF THE SFC
FRONT. OTHERWISE...TIMING OF THE FRONT BRINGS THE IT THROUGH THE
CWA BY EARLY AFTERNOON...WITH GUSTY NORTHWEST WINDS DEVELOPING
BEHIND WITH PRESSURE RISES AND FORECAST SOUNDINGS SHOWING MIXING
UPWARDS OF 8-850MB. COULD BE A BRIEF PERIOD...ESP LATER THIS
MORNING/NEAR MIDDAY WITH THE INITIAL PASSAGE OF THE FRONT...WHERE
SOME LOCATIONS FLIRT WITH WIND ADV CRITERIA...BUT WILL BE HOLDING
OFF ON ANY HEADLINE. DURING THE AFTERNOON HOURS...THE SUSTAINED
SPEEDS SHOULD TAPER OFF A BIT...BUT STILL WILL BE PLENTY GUSTY. BY
EVENING...SFC HIGH PRESSURE SETTLING IN FROM THE WEST SHOULD KNOCK
SPEEDS DOESNT CLOSER TO 10 MPH.
THE AREA OF CLOUD COVER MOVING IN THIS MORNING LOOKS TO KEEP SKIES
PARTLY/MOSTLY CLOUDY...MAINLY DURING THE FIRST HALF OF THE
DAY...BUT AM EXPECTING MORE SUN DURING THE AFTERNOON /ESP IN
CNTRL/WRN AREAS/. MAIN CHANGE MADE TO THE FORECAST FOR TODAY WAS
TO TREND BACK AFTERNOON DEWPOINTS...MAINLY ACROSS THE WRN HALF OF
THE CWA. FELT WITH THE DECENT MIXING BEHIND THE FRONT AND DRIER
AIR BUILDING IN...GOING CLOSER TO GUIDANCE WAS THE WAY TO GO. DID
NOT MAKE ANY NOTABLE CHANGES TO THE HIGHS...WHICH STILL LOOK TO
TOP OUT IN THE MID 50S TO NEAR 60S. WITH THE DECREASE IN AFTN
DEWPOINTS AND FORECAST HIGHS...THIS DID RESULT IN A DECREASE IN RH
VALUES...WITH AREAS GENERALLY ALONG/WEST OF A ODX/EAR/SMITH CENTER
KS LINE DROPPING INTO THE MID 20 PERCENT RANGE. CONDITIONS
EXPECTED TO REMAIN BELOW CRITICAL FIRE LEVELS...SO NO
HEADLINE...BUT WILL PUT AN ELEVATED MENTION IN THE HWO.
AS WE GET INTO TUESDAY AND WEDNESDAY...THE FORECAST REMAINS
PRECIPITATION FREE...MODELS ARE IN PRETTY GOOD AGREEMENT SHOWING
SLIGHTLY NORTHWESTERLY/ZONAL FLOW IN PLACE IN THE UPPER
LEVELS...WITH TODAYS TROUGH HAVING SHIFTED OFF TOWARD THE EAST
COAST AND VERY WEAK/BROAD RIDGING TO THE WEST. LOOKING AT THE
SURFACE PATTERN ON TUESDAY...EXPECTING TO SEE LIGHTER WINDS
CONTINUE WITH WEAKER HIGH PRESSURE IN PLACE OVER THE PLAINS...WITH
A PRIMARILY WESTERLY COMPONENT. INTO WEDNESDAY...AS ANOTHER UPPER
LEVEL TROUGH SETS UP TO THE WEST OF THE REGION...A SFC TROUGH
DEVELOPS OVER THE HIGH PLAINS...RESULTING IN A RETURN TO SOUTHERLY
WINDS ACROSS THE CWA. WEDNESDAY LOOKS TO BE ANOTHER BREEZY
DAY...WITH A TIGHTENING SFC PRESSURE GRADIENT ACROSS THE CENTRAL
PLAINS...SUSTAINED SPEEDS OF 15 TO 25 MPH WITH GUSTS OVER 30 MPH
ARE EXPECTED.
AS FAR AS TEMPERATURES GO THROUGH WEDNESDAY...DONT SEE A
SIGNIFICANT CHANGE EITHER WAY IN THE AIRMASS IN PLACE...AND
TUESDAYS HIGHS LOOK TO BE FAIRLY SIMILAR TO TODAY...IN THE MID
50S/NEAR 60. EXPECTING TO SEE A SLIGHT BUMP UP GETTING INTO
WEDNESDAY...THERE IS AN INCREASE IN TEMPS ALOFT...AND ALONG WITH
THE MORE SOLID SOUTHERLY FLOW...HIGHS IN THE UPPER 50S/LOWER 60S
ARE EXPECTED. ALSO WILL SEE THAT INCREASING TREND IN OVERNIGHT LOW
TEMPERATURES...TONIGHT WITH LIGHTER WINDS AND SFC HIGH PRESSURE IN
THE REGION...LOWS LOOK TO FALL INTO THE 20S. TUESDAY NIGHT AND
WEDNESDAY NIGHT...THE MORE SOUTHERLY WINDS ARE IN PLACE AND
SLIGHTLY WARMER AIR...SHOULD SEE LOWS IN THE UPPER 20S/LOW 30S
TUESDAY NIGHT AND MID/UPPER 30S WEDNESDAY NIGHT.
LONG TERM...THURSDAY THROUGH SUNDAY. THE WEATHER PATTERN UNDERGOES
CHANGES DURING THE LONG TERM PERIODS...ESPECIALLY HEADING INTO
NEXT WEEKEND. A TROUGH OF LOW PRESSURE TRANSLATES ACROSS CANADA ON
THURSDAY BRINGING AN ATTENDED COLD FRONTAL BOUNDARY ACROSS THE
CENTRAL PLAINS. IN PRESENCE OF MID LEVEL FRONTOGENESIS AND
DIVERGENCE ALOFT IN LFQ OF JET STREAK CROSSING THE SOUTHERN
PLAINS...SOME CHC FOR RAIN IS POSSIBLE. COOLER AIR FILTERS SOUTH
INTO OUR REGION BEHIND THE FRONT THURSDAY AND A GENERAL DOWNWARD
TREND IN TEMPS IS EXPECTED DURING LATTER PART OF THE WORKWEEK AND
ALSO HEADING INTO THE WEEKEND. COLD AIR BOTTLED UP IN CANADA WILL
MAKE A GRADUAL PROGRESSION SOUTH AS SHORTWAVE ENERGY TRANSLATES
ACROSS CANADA AND THE NORTHERN PLAINS. TEMPS SHOULD RETURN CLOSER
TO SEASONAL NORMALS BY FRIDAY/SATURDAY.
EXTENDED MODELS ADVERTISE A TROUGH TO IMPACT THE PLAINS NEXT
WEEKEND BUT DIFFER ON STRENGTH/TIMING OF SYSTEM. THE ECMWF IS MORE
PROGRESSIVE WITH WAVE AND BRINGS IN AN ARCTIC COLD FRONT ON SUNDAY
WITH POTENTIAL FOR A SNOW EVENT AND SIGNIFICANTLY COLDER TEMPS.
THE GFS ON THE OTHER HAND IS LESS SLOWER AND CLOSES OFF THE SYSTEM
NEAR THE FOUR CORNERS REGION DURING THE DAY ON SUNDAY WITH COLD
FRONT HOLDING OFF UNTIL SUNDAY AFTN/NIGHT. THE GFS ENSEMBLE MEAN
IS CLOSER TO THE 00Z ECMWF THAN THE 00 GFS...WITH THE MORE
PROGRESSIVE NATURE OF THE TROUGH. BOTH THE ECMWF AND GFS ENSEMBLE
MEAN ADVERTISE A NICE SURGE OF SIGNIFICANTLY COLDER AIR WITH H85
TEMPS POTENTIALLY DROPPING TO -10C TO -15C BY 12Z MONDAY. THIS
WILL BE A SYSTEM TO KEEP AN EYE ON AS IT IS STILL WELL INTO THE
EXTENDED PERIODS...BUT COULD FINALLY BRING IN SOME WINTRY
CONDITIONS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
1222 PM UPDATE/AVIATION/0954 AM UPDATE...BRYANT
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1005 AM CST MON DEC 3 2012
.UPDATE...
MINOR UPDATE TO ADJUST SKY COVER FOR TODAY.
&&
.DISCUSSION...
A BROAD UPPER LEVEL RIDGE REMAINS IN PLACE ACROSS THE MID SOUTH
TODAY. ABUNDANT LOW LEVEL MOISTURE CONTINUES TO ADVECT INTO
THE AREA ON SOUTHERLY WINDS. THIS HAS AGAIN RESULTED IN MORNING
STRATUS CLOUD DECK OVER PORTIONS OF THE REGION. OVER EASTERN
SECTIONS THIS STRATUS SHOULD EFFICIENTLY MIX OUT RESULTING IN
PARTLY TO MOSTLY SUNNY SKIES BY THIS AFTERNOON. FURTHER WEST...LOW
CLOUDS MAY PERSIST THROUGH MUCH OF THE DAY WHERE BETTER LOW LEVEL
LIFT ASSOCIATED WITH A STRONGER LOW LEVEL JET WILL RESIDE. PLAN TO
UPDATE THE SKY COVER TO REFLECT THE LATEST FORECAST THINKING.
OTHERWISE...THE REMAINDER OF THE FORECAST APPEARS ON TRACK AND NO
OTHER ELEMENTS WILL BE ADJUSTED AT THIS TIME.
STILL EXPECTING VERY WARM TEMPERATURES THIS AFTERNOON WHICH WILL
BE SEVERAL DEGREES ABOVE NORMAL FOR EARLY DECEMBER. UPDATED
FORECAST GRIDS AND ZONES WILL BE SENT SHORTLY.
JLH
&&
.PREV DISCUSSION... /ISSUED 444 AM CST MON DEC 3 2012/
NEAR RECORD HIGH TEMPERATURES EXPECTED ACROSS THE MIDSOUTH
TODAY... COURTESY OF UNDER LOW AMPLITUDE RIDGING ALOFT AND
SOUTHERLY ONSHORE LOW LEVEL FLOW.
A POSITIVELY TILTED UPPER LEVEL TROF WILL LIFT INTO THE GREAT
LAKES... OHIO VALLEY AND LOWER MS RIVER VALLEY TUESDAY. AN ASSOCIATED
SURFACE COLD FRONT WILL DROP THROUGH THE MIDSOUTH ON TUESDAY...
PROVIDING FOCUS FOR SHOWERS AND ISOLATED THUNDERSTORMS. MIXED
LAYER CAPES TO 750 J/KG AND MODEST WIND SHEAR MAY SUPPORT A AN
EMBEDDED STRONG THUNDERSTORM OR TWO. NO SEVERE WEATHER IS ANTICIPATED.
A PACIFIC SURFACE HIGH WILL SETTLE INTO THE MIDSOUTH ON WEDNESDAY.
WITH A GOOD AMOUNT OF SUNSHINE...POST FRONTAL AFTERNOON TEMPS
WILL WARM TO READINGS 7 TO 10 DEGREES ABOVE NORMAL.
THURSDAY NIGHT SHOULD SEE A WARM FRONT LIFT NORTH THROUGH THE
MIDSOUTH... INCREASING SURFACE DEWPOINTS BACK INTO THE 50S BY FRIDAY
AFTERNOON. A 90KT 250MB JET STREAK MAY ENHANCE THE CHANCES FOR WARM
SECTOR SHOWERS ALONG AND NORTH OF THE ADVANCING WARM FRONT THURSDAY
NIGHT AND FRIDAY. BETTER FOCUS FOR RAIN LATE FRIDAY WILL OCCUR
OVER THE OHIO VALLEY...NEAR THE POSITION OF THE SURFACE WARM FRONT.
BOTH 00Z GFS AND ECMWF KEEP THE MIDSOUTH IN THE MILD...RELATIVELY
HUMID AND WELL MIXED GULF AIRMASS THROUGH SUNDAY. GFS MEX GUIDANCE
TEMPS AND DEWPOINTS APPEAR REASONABLE AND MAY EVEN BE CONSERVATIVELY
COOL.
SIMILAR TO THE PAST SEVERAL DAYS... ECMWF AND GFS MODELS CONTINUED
TO SHOW POOR AGREEMENT AND CONTINUED TO EXHIBIT GREATER THAN
NORMAL RUN TO RUN INCONSISTENCIES BEYOND 180 HOURS. OF PARTICULAR
NOTE IS THE MODELS/ HANDLING OF A RELATIVELY POTENT SOUTHERN
BRANCH UPPER LEVEL LOW LIFTING THROUGH THE SOUTHERN U.S. NEXT WEEK.
HAVE FOLLOWED A COMPROMISE BETWEEN THE MORE PROGRESSIVE ECMWF AND
SLOWER GFS WITH RESPECT TO THIS SYSTEM...LIFTING THROUGH LATE
MONDAY INTO TUESDAY. BOTH MODELS SUGGEST SOME SEVERE POTENTIAL
EXISTS WITH THIS SYSTEM...BUT IT REMAINS FAR TOO EARLY TO PIN DOWN
TIMING AND MAGNITUDE OF ANY SEVERE POTENTIAL.
PWB
&&
.AVIATION...
12Z TAF SET
IFR/MVFR CIGS CONTINUE TO DEVELOP OVER ARKANSAS AT THIS TIME.
LATEST RUC KEEPS CIGS WEST OF THE MS RIVER THUS HAVE KEPT KMEM VFR
THIS MORNING. KJBR SHOULD BE ONLY TAF SITE THAT EXPERIENCES IFR
CIGS BY 14-15Z THIS MORNING. CIGS WILL GRADUALLY LIFT AFTER
17-18Z. BY 19-21Z...VFR CONDITIONS SHOULD PREVAIL EVERYWHERE. MVFR
CIGS WILL BEGIN TO SPREAD INTO CWA AGAIN AFTER 06Z POSSIBLY LOWER
NEAR KJBR. KJBR COULD SEE A FEW TSRAS DEVELOP AHEAD OF APPROACHING
COLD FRONT AFTER 09Z. IN ADDITION...WOULD NOT BE SURPRISED TO SEE
A FEW ELEVATED TSRAS DEVELOP NEAR KTUP AFTER 8-9Z DUE TO WAA.
STRONG S WINDS EXPECTED AFTER 15Z. SPEEDS WILL INCREASE TO 12-17
KTS WITH HIGHER GUSTS. SPEEDS WILL DIE DOWN TO 8-10 KTS AFTER
00Z...POSSIBLY LOWER AT KTUP.
KRM
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 75 62 69 43 / 0 30 90 10
MKL 74 58 67 41 / 0 20 90 10
JBR 74 59 65 40 / 10 70 80 0
TUP 74 56 71 47 / 0 0 80 60
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1023 AM PST Mon Dec 3 2012
.SYNOPSIS...
Today`s weather will bring a brief showery break to the persistent
wet weather of late. Most of the showers will be confined to the
Idaho Panhandle...eastern quarter of Washington and near the
cascade crest. a strong and moist storm system will deliver
widespread valley rain and mountain snow to all areas beginning
late tonight and continuing through Tuesday. The snow could be
locally heavy near the cascades and over the highest mountains
elsewhere. The remainder of the week will be cooler and
showery...but no further strong storms are expected through next
weekend.
&&
.DISCUSSION...
Forecast update to decrease POPs and sky cover for today. Morning
satellite imagery showed a pocket of clear skies over the basin.
Best chances for any showers today will be over the mountains,
mainly over the Cascade crest and in the Idaho Panhandle. Radar
has shown showers decreasing in coverage through the late morning
hours. The HRRR model seems to be doing a decent job with the
precipitation and shows these showers continuing to decrease into
this afternoon. We will continue with moist upslope flow into the
Panhandle today, but we will become less unstable as well. Some
isolated snow showers above 4000 feet will continue through the
afternoon across the Central Panhandle Mountains, but any
additional snow accumulations are expected to be light. Web cams
also show roads in the higher terrain of the Central Panhandle
transitioning from snow covered to bare and wet. Due to the
improving conditions, we decided to drop the Winter Storm Waring
for this area. The Winter Storm Watches will continue for the next
system expected to arrive tonight. /SVH
&&
.AVIATION...
18Z TAFS: Some mountain wave clouds will continue to develop
across the region this afternoon. These clouds may produce some
weak showers across the mountains. A shower or two may develop
around the KPUW, KLWS and KCOE taf sites as well, but all other
terminals should remain dry this afternoon. Another moist system
will begin to push into the region this evening. Some weak rain
bands may develop as low level flow begins to back a bit from more
westerly to more southerly. This will result in some light showers
across the region, but the bulk of the moisture is not expected to
arrive until late tonight into early Tuesday morning. Light to
moderate rainfall will be possible with lowering cigs to MVFR
conditions at most taf sites. Best confidence of MVFR cigs will be
at KEAT, KGEG and KCOE. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 45 38 47 37 40 29 / 10 40 100 70 20 10
Coeur d`Alene 46 37 45 36 39 29 / 10 40 100 80 50 30
Pullman 47 39 46 38 41 31 / 20 30 90 100 50 10
Lewiston 53 41 50 41 47 35 / 20 20 80 60 40 10
Colville 45 39 44 37 39 29 / 10 80 100 60 20 20
Sandpoint 43 36 42 35 37 29 / 20 60 100 100 60 50
Kellogg 39 35 40 35 36 31 / 40 60 100 100 80 50
Moses Lake 49 40 52 35 44 29 / 10 60 90 30 10 10
Wenatchee 45 39 45 35 43 29 / 20 70 90 30 10 10
Omak 45 38 42 33 39 27 / 10 90 100 40 10 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Winter Storm Watch from this evening through Tuesday afternoon
for Northern Panhandle.
WA...Winter Storm Watch from this evening through Tuesday afternoon
for Northeast Mountains-Okanogan Highlands.
Winter Storm Watch from this evening through Tuesday morning for
East Slopes Northern Cascades.
&&
$$