Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 12/04/12
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
953 AM MST SUN DEC 2 2012
.UPDATE...
ISSUED AT 952 AM MST SUN DEC 2 2012
BROAD BAROCLINIC LEAF CURRENTLY OVER THE NORTHERN ROCKIES IS
BRINGING PLENTY OF PRECIPITATION TO THAT AREA WHILE WE REMAIN
RELATIVELY CLOUD FREE. THIS WILL ALL CHANGE OVER THE NEXT FEW
HOURS AS CLOUDS START TO THICKEN FROM THE NORTHWEST AND LOWER
THROUGH THE DAY. NO HUGE CHANGES TO GOING FORECAST THOUGH NAM12
AND HRRR CROSS SECTIONS FROM VERNAL THROUGH CRAIG TO STEAMBOAT
SPRINGS DO SHOW MINIMAL MOISTURE IN MID TO LOWER LEVELS INCLUDING
THE DENDRITIC GROWTH REGION UNTIL 03Z. FOR THIS UPDATE
THEN...BUMPED BACK ONSET OF PRECIP TO THIS EVENING WITH MOST
PRECIP EXPECTED AFTER MIDNIGHT.
$$
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 408 AM MST SUN DEC 2 2012
WHILE THE CASCADES GET POUNDED WITH MOISTURE...THE ROCKIES GET
JUST A SMALL DRINK. AT THIS POINT WE WILL HAPPILY TAKE ANYTHING.
A VIGOROUS TROUGH WORKS INTO THE PACIFIC NORTHWEST THIS MORNING
AND WILL SWEEP TO THE NORTH OF OUR FORECAST AREA TONIGHT INTO
MONDAY. MODELS REMAIN IN GOOD AGREEMENT WITH TIMING AND IMPORTANT
STORM DETAILS.
700MB FLOW BACKS FROM SW TO SSW TODAY AND STRENGTHENS TO 40/25KTS
NORTH/SOUTH THIS AFTERNOON. THIS WARM ADVECTIVE PATTERN WILL BRING
MID-HIGH CLOUDS AND AFTERNOON TEMPERATURES NEAR RECORD VALUES.
IN SPITE OF THE WARMTH...DEEP VALLEY MIXING WILL BE LIMITED MAINLY
TO THE NORTHERN VALLEYS.
DEEPER MOISTURE (PRECIP WATER OF 0.6 INCHES) ARRIVES LATE THIS
AFTERNOON AND EVENING AS THE RIGHT ENTRANCE QUADRANT OF THE
UPRIGHT JET PRODUCES MID LEVEL Q CONVERGENCE OVER THE NORTHERN
CWA. THE COOL FRONT WORKS THROUGH THE NORTHERN AND CENTRAL ZONES
AFTER MIDNIGHT AND INTO MONDAY MORNING. FLOW VEERS TO WEST TONIGHT
THEN WNW ON MONDAY WITH 700MB TEMPERATURES ONLY LOWERING TO -6/-1C
NORTH/SOUTH. THESE RELATIVELY MILD MTN TOP TEMPERATURES LOWER SNOW
LEVELS TO AROUND 6000FT NORTH...8500 FEET SOUTH. IT WILL ALSO
PRODUCE A RELATIVELY WET MTN SNOW STARTING OUT AT 10:1 RATIO THIS
EVENING AND INCREASING TO 14:1 TOWARDS MONDAY MORNING.
MOISTURE QUICKLY DIMINISHES FROM NW TO SE ON MONDAY. WITH ONLY A
-20C COLD CORE ACROSS THE NORTH...MONDAY INSTABILITY WILL BE VERY
LIMITED. THEREFORE SUB ADVISORY SNOW AMOUNTS ARE EXPECTED EVEN FOR
THE FAVORED NORTHERN MTNS.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 408 AM MST SUN DEC 2 2012
CLEARING AND COOLER CONDITIONS EXPECTED MONDAY NIGHT IN THE WAKE
OF EXITING WAVE AS WEAK SHRTWV RIDGING BUILDS IN FROM THE WEST.
PATTERN REMAINS PROGRESSIVE WITH MID AND HIGH LEVEL PACIFIC MOISTURE
CONTINUING TO PUSH THROUGH THE REGION BRINGING PERIODS OF CLOUDS
AND POSSIBLY A FEW SHOWERS ACROSS THE NORTHERN MOUNTAINS BY EARLY
WEDNESDAY AS THE RIDGE BREAKS DOWN. ANOTHER STRONGER SYSTEM
APPROACHES LATE WEDNESDAY NIGHT AND THURSDAY...PROMISING MORE HIGH
ELEVATIONS SNOW AS THE WARM NATURE OF THIS SYSTEM KEEPS SNOW
LEVELS AOA 8K. THIS SYSTEM EXITS THURSDAY AFTERNOON AND EVENING
WITH ANOTHER BREAK FRIDAY AND SATURDAY AS HEIGHTS START TO CLIMB
ALONG THE WEST COAST. PATTERN BECOMES MORE INTERESTING LATE
SATURDAY AND SUNDAY...ESPECIALLY IN THE GFS WHICH ADVERTISES A
FAIRLY NICE SURGE OF COLDER AIR AND MOISTURE AS WE CLOSE OUT THE
WEEKEND. HOWEVER...TRAJECTORY OF THE SYSTEM COMING ACROSS CANADA
AND THE NORTHERN ROCKIES SHOULD ELIMINATE MUCH OF THE OVERLY
INFLATED QPF VALUES...BUT WITH A COLDER AIRMASS...COULD STILL SEE
SIGNIFICANT PRECIPITATION. AS HAS BEEN THE CASE THIS SEASON...THE
ECMWF NOT QUITE IN AGREEMENT AT THIS TIME...SO CONFIDENCE REMAINS
LOW. TEMPERATURES WILL REMAIN AOA SEASONAL NORMS THROUGH
THURSDAY...WITH SLIGHTLY COOLER WEATHER EXPECTED FRIDAY AND
SATURDAY WITH MORE SIGNIFICANT COOL DOWN POSSIBLY ARRIVING FOR
SUNDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z NOON MONDAY)
ISSUED AT 952 AM MST SUN DEC 2 2012
VFR IS EXPECTED THROUGH THIS EVENING THOUGH CLOUDS WILL INCREASE
IN DEPTH AND COVERAGE AS THE DAY PROGRESSES. EXPECT BKN TO OVC SKIES TO
BECOME PREDOMINANT AS THE DAY WEARS ON. BY 06Z TONIGHT...SOME
MVFR POSSIBLE FOR KCAG...KHDN...KSBS...KRIL...KASE...AND KEGE AFTER 06Z
AS CIGS/VIS DROP DUE TO RAIN SHOWERS AND SNOW. THESE CONDITIONS
WILL PERSIST THROUGH 15Z OR SO. DURING THE DAY MONDAY...PRECIP
WILL SHIFT SOUTHWARD BUT AS IT DOES IT WILL WEAKEN KEEPING
CONDITIONS MOSTLY VFR.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
UPDATE...TGR
SHORT TERM...JOE
LONG TERM...JDC
AVIATION...TGR
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
1233 PM EST SUN DEC 2 2012
.SYNOPSIS...
HIGH PRESSURE WILL PREVAIL EARLY THIS WEEK...WHILE A WEAK COASTAL
TROUGH PERSISTS ALONG THE SOUTHEAST COAST. A COLD FRONT WILL THEN
PASS THROUGH THE AREA WEDNESDAY NIGHT FOLLOWED BY COOLER HIGH
PRESSURE FOR THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NUDGED HIGH TEMPERATURES UP A DEG OR TWO FOR MOST LOCATIONS PER
GOING TRENDS. OTHERWISE...THE FORECAST IS ON TRACK. CLOUDS OFF THE
GEORGIA COAST POSE SOME CONCERN AS THEY COULD MAKE A RUN FOR THE
COAST AND YIELD MOSTLY CLOUDY SKIES FOR THE REMAINDER OF THE
AFTERNOON. RAP 295K ISENTROPIC PROG SHOWED THE AREA OF CLOUDINESS
RATHER WELL AND KEEPS THE BULK OF IT OFFSHORE. DID NOT MAKE ANY
CHANGES TO THE SKY FORECAST IN AREA FOR THIS REASON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
TONIGHT...HIGH PRESSURE WILL SHIFT SOUTHWARD OFF THE CAROLINA
COAST ALLOWING A SOUTHERLY RETURN FLOW TO DEVELOP...WHICH WILL
HELP TO ADVECT GREATER LOW LEVEL MOISTURE INTO THE AREA. THIS
MOISTURE COMBINED WITH DECOUPLED WINDS COULD POTENTIALLY LEAD TO
AREAS OF FOG WHICH COULD BECOME LOCALLY DENSE AT TIMES.
HOWEVER...THE BIG UNCERTAINTY IS THE EXTENT OF CLOUD COVER OVER
THE AREA AS CONTINUED WEAK ISENTROPIC ASCENT COULD SUPPORT PARTLY
TO MOSTLY CLOUDY SKIES THROUGH MUCH OF THE NIGHT. GIVEN THIS
UNCERTAINTY...THE FORECAST WILL JUST INDICATE PATCHY FOG AT THIS
TIME UNTIL SKY COVER TRENDS CAN BECOME BETTER ESTABLISHED.
ISOLATED SHOWERS ARE POSSIBLE TONIGHT ONCE AGAIN JUST
OFFSHORE...AND THE POTENTIAL IS THERE FOR SOME OF THEM TO SHIFT
INLAND AND AFFECT COASTAL COUNTIES. TONIGHT WILL BE UNSEASONABLY
WARM WITH THE DEVELOPING RETURN FLOW AND EXPECTED CLOUD COVER
KEEPING LOWS IN THE LOWER 50S INLAND AND MID TO UPPER 50S NEAR THE
IMMEDIATE COAST.
DEEP HIGH PRESSURE OVER THE AREA MONDAY ALONG WITH A COASTAL TROUGH
OF LOW PRESSURE OVER THE NEARBY ATLANTIC WILL SLOWLY BREAK DOWN
THROUGH MID WEEK AS A COLD FRONT APPROACHES FROM THE WEST. THE FRONT
LOOKS TO PUSH INTO THE AREA LATE IN THE DAY WEDNESDAY FROM THE
NORTHWEST. OVERALL EXPECT LOW RAIN CHANCES THROUGH THE PERIOD. THERE
WILL BE A RISK FOR FOG EACH MORNING DUE TO SUFFICIENT LOW-LEVEL
MOISTURE AND LIGHT WINDS...ESPECIALLY MONDAY AND TUESDAY...AND IT
COULD BECOME DENSE. TEMPERATURES WILL BE WELL ABOVE NORMAL THROUGH
THE PERIOD...WITH LOWER TO MID 70S FOR HIGHS AND GENERALLY AROUND 50 FOR
LOWS /COOLEST INLAND AND WARMEST ALONG THE COAST/.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
PRETTY GOOD MODEL AGREEMENT THROUGH THE END OF THE WEEK WITH MORE
DISAGREEMENT LATE NEXT WEEKEND. A COLD FRONT WILL PASS SOUTHEAST
THROUGH THE AREA WEDNESDAY NIGHT WITH A HIGH PRESSURE WEDGE SETTING
UP THURSDAY INTO FRIDAY...WITH A COASTAL TROUGH OFFSHORE. ATLANTIC
HIGH PRESSURE THEN LOOKS TO DOMINATE SATURDAY INTO SUNDAY WITH THE
POSSIBILITY OF ANOTHER FRONT LATE IN THE WEEKEND. SMALL RAIN CHANCES
WILL CONTINUE THURSDAY AND COULD LINGER NEAR THE COAST INTO FRIDAY
DUE TO THE COASTAL TROUGH AND THEN COULD INCREASE FROM THE WEST AS
EARLY AS LATE SATURDAY DEPENDING ON THE SPEED OF THE NEXT FRONT.
HIGH TEMPERATURES WILL BE CLOSE TO NORMAL THURSDAY BEFORE MODERATING
TOWARD THE END OF TH WEEK. LOWS SHOULD REMAIN ABOVE NORMAL.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
VFR CONDITIONS WILL PREVAIL THROUGH THE REMAINDER OF THE AFTERNOON
WITH FORECAST CONFIDENCE WANING THEREAFTER. OVERNIGHT...FOG
DEVELOPMENT WILL GREATLY DEPEND ON CLOUD COVERAGE. EXPECT SOME
SCATTERED CLOUDS TO LINGER INTO AT LEAST THE FIRST PORTION OF THE
NIGHT...BUT SOME MODELS SUGGEST DECENT CLEARING AFTER MIDNIGHT. IF
CLEARING DEVELOPS...DECENT TO EXCELLENT RADIATIONAL COOLING
CONDITIONS COULD RESULT IN SCATTERED TO DENSE FOG. AT THIS
POINT...WILL MAINTAIN LOW-END MVFR VISIBILITIES AFTER 07Z AND WILL
REEVALUATE FOG POTENTIAL AT LATER TAF ISSUANCES.
EXTENDED AVIATION OUTLOOK...MVFR CEILINGS AND VISIBILITIES ARE
EXPECTED DURING THE LATE NIGHT/EARLY MORNING HOURS THROUGH WEDNESDAY
WITH IFR OR WORSE CONDITIONS LIKELY. LOW CIGS LOOK TO RETURN
WEDNESDAY NIGHT INTO THURSDAY ALONG AND BEHIND A COLD FRONT.
&&
.MARINE...
THIS AFTERNOON...WW4 OUTPUT SHOWS SEAS AT 6 FT OVER THE EASTERN
HALF OF THE GEORGIA OFFSHORE ZONE THIS MORNING. SEAS AT BOTH
41004 AND 41008 MATCH WW4 OUTPUT ALMOST EXACTLY...SO SEE NO REASON
TO QUESTION ITS DEPICTION OF 6 FT SEAS. 6 FT SEAS WILL REMAIN
OVER THE GEORGIA OFFSHORE LEG THROUGH LATE AFTERNOON AS THE SWELL
TRAIN THAT WAS GENERATED BY LONG-FETCH EASTERLY FLOW OVER THE OPEN
ATLANTIC CONTINUES TO IMPACT THE LOCAL MARINE AREA. HAVE ISSUED A
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL LATE AFTERNOON TO
ADDRESS THIS SITUATION.
TONIGHT...HIGH PRESSURE WILL DROP SOUTHWARD OFF THE COAST OF THE
CAROLINAS...ALLOWING A SOUTH OR SOUTHEAST FLOW TO DEVELOP OVER THE
COASTAL WATERS WITH SPEEDS GENERALLY 10 KT OR LESS. SEAS WILL
SUBSIDE BY ABOUT A FOOT OR SO THROUGH THE NIGHT.
SUNDAY THROUGH FRIDAY...ATLANTIC HIGH PRESSURE WILL CONTINUE TO BE
THE DOMINANT WEATHER FEATURE ACROSS THE SC/GA COASTAL WATERS THROUGH
TUESDAY WITH A TROUGH OF LOW PRESSURE LINGERING NEARBY. A COLD FRONT
WILL THEN PUSH THROUGH WEDNESDAY NIGHT FOLLOWED BY HIGH PRESSURE
WEDGING DOWN THE COAST FROM THE NORTH THURSDAY INTO FRIDAY. SEAS
COULD REACH 6 FT ACROSS THE EASTERN PORTIONS OF THE OUTER GA WATERS
SUNDAY BUT CONFIDENCE TOO LOW TO WARRANT RAISING AN ADVISORY.
OTHERWISE...NO CONCERNS WITH RESPECT TO WINDS AND SEAS UNTIL
WEDNESDAY NIGHT/THURSDAY WHEN A NORTHEAST SURGE KICKS IN BEHIND THE
FRONT. SMALL RISK FOR HEADLINES THURSDAY/THURSDAY...MAINLY FOR THE
CHARLESTON COUNTY COASTAL WATERS AND OUTER GA WATERS. WILL KEEP AN
EYE ON THE POTENTIAL FOR SOME SEA FOG TUESDAY INTO WEDNESDAY ACROSS
THE NEARSHORE WATERS GIVEN THE POSSIBILITY OF HIGHER DEWPOINTS
MOVING INTO THE AREA.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 5 PM EST THIS
AFTERNOON FOR AMZ374.
&&
$$
ST/JHP
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1135 AM CST SUN DEC 2 2012
.DISCUSSION...
ISSUED 1022 AM CST SUN DEC 2 2012
AREA OF DENSE FOG IN WEST CENTRAL ILLINOIS HAS CREPT EASTWARD THE
LAST COUPLE HOURS...INTO PARTS OF KNOX...FULTON AND SCHUYLER
COUNTIES. COVERAGE AREA IS EXPECTED TO SHRINK OVER THE NEXT COUPLE
OF HOURS...SO WILL HANDLE THIS WITH A SPECIAL WEATHER STATEMENT
INSTEAD OF ISSUING A DENSE FOG ADVISORY. OTHERWISE...MAIN CONCERN
IS WITH TIMING OF ANY CLEARING TODAY. HAVE BEEN SEEING SOME
FILTERED SUNSHINE SOUTH OF I-72...BUT STRATOCUMULUS DECK TO THE
NORTH WILL DROP A LITTLE FURTHER SOUTHEAST OVER THE NEXT FEW
HOURS. RAP MODEL TRYING TO SHOW SOME CLEARING THIS AFTERNOON WEST
OF THE ILLINOIS RIVER...BUT RECENT GRID UPDATES WERE NOT QUITE AS
AGGRESSIVE ALTHOUGH STILL SHOWING SOME SUNSHINE BY MID AFTERNOON.
THE EARLIER RAIN HAD DROPPED TO THE OHIO RIVER...SO REMOVED THE
RAIN MENTION ACROSS THE EASTERN CWA. BOOSTED TEMPERATURES A COUPLE
DEGREES AT MOST LOCATIONS.
UPDATED GRIDS/ZONES HAVE BEEN SENT.
GEELHART
&&
.AVIATION...
ISSUED 1135 AM CST SUN DEC 2 2012
CEILING/VISIBILITY ISSUES EXPECTED TO BE PREVALENT DURING A LARGE
PORTION OF THE TAF PERIOD. OF IMMINENT CONCERN IS AREA OF LIFR
CONDITIONS JUST WEST OF KPIA...WHERE CEILINGS DOWN TO 200 FEET IN
DENSE FOG. LATEST OBS FROM KGBG/KMQB SHOWING RISING
VISIBILITIES...BUT WILL KEEP MVFR CEILINGS AT KPIA/KBMI MUCH OF
THE AFTERNOON. LINGERING CEILINGS BELOW 3000 FEET FURTHER SOUTH
EXPECTED TO RISE OVER THE NEXT HOUR OR SO. MAIN QUESTION WILL BE
WITH ANY REDEVELOPMENT OF LOW CLOUDS/DENSE FOG TONIGHT. LATEST
MODEL GUIDANCE SUGGESTS ANY SUCH OCCURRENCE WOULD START AROUND
KCMI/SOUTHWARD LATE THIS EVENING AND ADVECT TO THE NORTHWEST...
AND HAVE SPREAD IFR CEILINGS OVER THE TAF SITES BY 08Z. HOWEVER...
WINDS EXPECTED TO BE A BIT HIGHER THAN FIRST THOUGHT...AND THIS
MAY HELP VISIBILITIES FROM COMPLETELY TANKING. USING THIS LINE OF
THOUGHT...HAVE ADDED SOME TEMPO PERIODS OF 1/2 TO 3/4SM
VISIBILITY INSTEAD OF PREVAILING VALUES. WINDS INCREASING TO
AROUND 15 KNOTS LATE IN THE PERIOD WILL HELP THE LOWER
VISIBILITIES COME UP QUICKLY...BUT SOUNDINGS SHOW CEILINGS MAY NOT
RISE TO VFR RANGE UNTIL CLOSER TO 18Z.
GEELHART
&&
.PREV DISCUSSION...
ISSUED 330 AM CST SUN DEC 2 2012
SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
A FAIRLY ACTIVE WEATHER PATTERN EXPECTED THIS WEEK WITH
THREE WEATHER SYSTEMS TO IMPACT IL BRINGING RAIN CHANCES.
THE 1ST SYSTEM IS WITH SCATTERED SHOWERS EXITING EASTERN IL INTO
MID MORNING. THEN A STRONGER COLD FRONT TO MOVE SE THROUGH IL
MONDAY NIGHT BRINGING A BETTER CHANCE OF SHOWERS AND ISOLATED
THUNDERSTORMS. UNSEASONABLY WARM TEMPERATURES EXPECTED THROUGH
MONDAY AND MET/MAV GUIDANCE HIGHS CONTINUE TO BE NEAR RECORD HIGHS
FOR DEC 3RD AND MONTH OF DECEMBER IN THE LOWER 70S. A 3RD FRONT
SETS UP NEAR THE OHIO RIVER LATE THIS WEEK WITH OVERRUNNING
RAIN CHANCES OVER CENTRAL AND ESPECIALLY SE IL. MET AND MAV
GUIDANCE TEMPS SIMILAR THROUGH TUE AND STAYED CLOSE TO.
RADAR MOSAIC SHOWS SCATTERED SHOWERS OVER EASTERN IL (EAST OF
HIGHWAY 51) AND TRACKING ENE INTO INDIANA. A FEW THUNDERSTORMS
WERE NOTED OVER SOUTHERN LAKE MI INTO SW LOWER MI. THESE AHEAD OF
A WEAK FRONT OVER SE IA AND NW MO. SOUTH BREEZES (GUSTING AS HIGH
AS 20-30 MPH EAST OF THE IL RIVER) AND CLOUDS AHEAD OF THIS FRONT
BRINGING UNSEASONABLY MILD TEMPS IN THE MID 50S TO LOWER 60S EARLY
THIS MORNING OVER CENTRAL/SE IL. MOIST DEWPOINTS IN THE LOWER 50S.
WILL CONTINUE 20-40% CHANCE OF RAIN SHOWERS OVER EASTERN IL INTO
MID MORNING AND ALSO CARRY PATCHY FOG OVER THE IL RIVER VALLEY.
BUT FOG WILL BE MORE WIDESPREAD TO OUR NW OVER IA AND NORTHERN MO.
NOT AS BREEZY TODAY AS WEAK FRONT MOVES EAST INTO IL AND CLOUDS TO
DECREASE OVER THE IL RIVER VALLEY. HIGHS MOSTLY IN THE LOW TO MID
60S TODAY WITH SOME UPPER 60S OVER SW/SOUTHERN AREAS. RECORD
HIGHS TODAY DEC 2 ARE IN THE UPPER 60S TO AROUND 70F.
HAVE PATCHY FOG OVERNIGHT WITH MILD LOWS IN THE LOW TO MID 50S.
EVEN WARMER MONDAY WITH NEAR RECORDS HIGHS OF 69-73F WITH SOUTHERN
AREAS GETTING THE WARMEST. STRONGER SOUTH WINDS SET UP AGAIN
MONDAY SIMILAR TO WHAT HAPPENED YESTERDAY/SATURDAY. HAVE 20-30%
CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS OVER THE IL RIVER
VALLEY MONDAY AFTERNOON. BEST CHANCES OF SHOWERS AND ISOLATED
THUNDERSTORMS IS MONDAY NIGHT STORM SYSTEM NEAR THE PACIFIC STATES
BRINGS A STRONGER COLD FRONT SE THROUGH IL. CHANCE OF SHOWERS
LINGERS TUE MORNING SE OF I-55 ESPECIALLY OVER SE IL THEN DRIER BY
TUE AFTERNOON WITH CLOUDS DECREASING TUE FROM NW TO SE. MUCH
COOLER HIGHS IN THE MID TO UPPER 50S WITH SE IL NEAR 60F...BUT
STILL ABOVE NORMAL HIGHS FOR EARLY DECEMBER IN THE LOWER TO MIDDLE
40S.
QUIET AND SEASONABLY COOL WEATHER EXPECTED TUE NIGHT THROUGH WED
NIGHT AS HIGH PRESSURE SETTLES INTO THE REGION. HIGHS WED IN THE
MID TO UPPER 40S...WITH SOME LOWER 50S SW AREAS.
LONG TERM...THURSDAY THROUGH SATURDAY NIGHT
EXTENDED MODELS HAVE TRENDED FURTHER SE WITH FRONTAL BOUNDARY NEAR
THE OHIO RIVER LATE THIS WEEK WITH OVERRUNNING RAIN CHANCES INTO
CENTRAL AND ESPECIALLY SE IL THU NIGHT INTO FRI NIGHT. ECMWF
MODELS CONTINUES QPF INTO CENTRAL/SE IL INTO SAT THOUGH THINK THIS
IS TOO FAR NORTH WITH MODELS TRENDING SOUTHWARD WITH THIS SYSTEM.
MOST OF THE PRECIPITATION APPEARS TO FALL AS RAIN BUT COULD HAVE
MIX DEVELOPING DURING FRI NIGHT ESPECIALLY NORTH OF I-70 AFTER
MIDNIGHT IF PRECIP LINGERS THAT LONG. HIGHS IN THE LOW TO MID 50S
THU GRADUALLY COOL CLOSER TO NORMAL BY NEXT WEEKEND.
07
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1023 AM CST SUN DEC 2 2012
.DISCUSSION...
ISSUED 1022 AM CST SUN DEC 2 2012
AREA OF DENSE FOG IN WEST CENTRAL ILLINOIS HAS CREPT EASTWARD THE
LAST COUPLE HOURS...INTO PARTS OF KNOX...FULTON AND SCHUYLER
COUNTIES. COVERAGE AREA IS EXPECTED TO SHRINK OVER THE NEXT COUPLE
OF HOURS...SO WILL HANDLE THIS WITH A SPECIAL WEATHER STATEMENT
INSTEAD OF ISSUING A DENSE FOG ADVISORY. OTHERWISE...MAIN CONCERN
IS WITH TIMING OF ANY CLEARING TODAY. HAVE BEEN SEEING SOME
FILTERED SUNSHINE SOUTH OF I-72...BUT STRATOCUMULUS DECK TO THE
NORTH WILL DROP A LITTLE FURTHER SOUTHEAST OVER THE NEXT FEW
HOURS. RAP MODEL TRYING TO SHOW SOME CLEARING THIS AFTERNOON WEST
OF THE ILLINOIS RIVER...BUT RECENT GRID UPDATES WERE NOT QUITE AS
AGGRESSIVE ALTHOUGH STILL SHOWING SOME SUNSHINE BY MID AFTERNOON.
THE EARLIER RAIN HAD DROPPED TO THE OHIO RIVER...SO REMOVED THE
RAIN MENTION ACROSS THE EASTERN CWA. BOOSTED TEMPERATURES A COUPLE
DEGREES AT MOST LOCATIONS.
UPDATED GRIDS/ZONES HAVE BEEN SENT.
GEELHART
&&
.AVIATION...
ISSUED 556 AM CST SUN DEC 2 2012...FOR THE 12Z TAFS
A BRIEF BREAK IN THE CLOUD COVER EXPECTED FOR SPI/DEC JUST AHEAD
OF THE WEAK SURFACE FRONT MOVING ACROSS IL TODAY. LOW MOISTURE
WILL INCREASE ALONG AND BEHIND THE TROUGH...BRINGING MVFR CEILINGS
EVERYWHERE BY MID MORNING AND INTO THE AFTERNOON. BRIEF CLEARING
MAY OCCUR THIS EVENING, BUT FOG AND LOW CLOUDS WILL RETURN BY
MIDNIGHT IN MOST AREAS. LIFR IF NOT VLIFR FOG WILL BE POSSIBLE BY
09Z...BASED ON NAM FORECAST SOUNDINGS. WE INCLUDED A MENTION OF
DENSE FOG LATE TONIGHT WITH THIS 12Z TAF ISSUANCE...DUE TO THE
WIDESPREAD FOG BEHIND THE SYSTEM THIS MORNING IN IOWA AND N
MISSOURI. CONFIDENCE IS INCREASING ABOUT A DENSE FOG EVENT BY
SUNRISE TOMORROW.
WINDS WILL SHIFT FROM SOUTHWEST TO WEST BEHIND THE WEAK SURFACE
TROUGH...WITH WIND SPEED DECREASING BELOW 10KT AS IT DOES. LIGHT
AND VARIABLE WINDS LATER TONIGHT WILL HELP WITH THE FOG FORMATION.
SHIMON
&&
.PREV DISCUSSION...
ISSUED 330 AM CST SUN DEC 2 2012
SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
A FAIRLY ACTIVE WEATHER PATTERN EXPECTED THIS WEEK WITH
THREE WEATHER SYSTEMS TO IMPACT IL BRINGING RAIN CHANCES.
THE 1ST SYSTEM IS WITH SCATTERED SHOWERS EXITING EASTERN IL INTO
MID MORNING. THEN A STRONGER COLD FRONT TO MOVE SE THROUGH IL
MONDAY NIGHT BRINGING A BETTER CHANCE OF SHOWERS AND ISOLATED
THUNDERSTORMS. UNSEASONABLY WARM TEMPERATURES EXPECTED THROUGH
MONDAY AND MET/MAV GUIDANCE HIGHS CONTINUE TO BE NEAR RECORD HIGHS
FOR DEC 3RD AND MONTH OF DECEMBER IN THE LOWER 70S. A 3RD FRONT
SETS UP NEAR THE OHIO RIVER LATE THIS WEEK WITH OVERRUNNING
RAIN CHANCES OVER CENTRAL AND ESPECIALLY SE IL. MET AND MAV
GUIDANCE TEMPS SIMILAR THROUGH TUE AND STAYED CLOSE TO.
RADAR MOSAIC SHOWS SCATTERED SHOWERS OVER EASTERN IL (EAST OF
HIGHWAY 51) AND TRACKING ENE INTO INDIANA. A FEW THUNDERSTORMS
WERE NOTED OVER SOUTHERN LAKE MI INTO SW LOWER MI. THESE AHEAD OF
A WEAK FRONT OVER SE IA AND NW MO. SOUTH BREEZES (GUSTING AS HIGH
AS 20-30 MPH EAST OF THE IL RIVER) AND CLOUDS AHEAD OF THIS FRONT
BRINGING UNSEASONABLY MILD TEMPS IN THE MID 50S TO LOWER 60S EARLY
THIS MORNING OVER CENTRAL/SE IL. MOIST DEWPOINTS IN THE LOWER 50S.
WILL CONTINUE 20-40% CHANCE OF RAIN SHOWERS OVER EASTERN IL INTO
MID MORNING AND ALSO CARRY PATCHY FOG OVER THE IL RIVER VALLEY.
BUT FOG WILL BE MORE WIDESPREAD TO OUR NW OVER IA AND NORTHERN MO.
NOT AS BREEZY TODAY AS WEAK FRONT MOVES EAST INTO IL AND CLOUDS TO
DECREASE OVER THE IL RIVER VALLEY. HIGHS MOSTLY IN THE LOW TO MID
60S TODAY WITH SOME UPPER 60S OVER SW/SOUTHERN AREAS. RECORD
HIGHS TODAY DEC 2 ARE IN THE UPPER 60S TO AROUND 70F.
HAVE PATCHY FOG OVERNIGHT WITH MILD LOWS IN THE LOW TO MID 50S.
EVEN WARMER MONDAY WITH NEAR RECORDS HIGHS OF 69-73F WITH SOUTHERN
AREAS GETTING THE WARMEST. STRONGER SOUTH WINDS SET UP AGAIN
MONDAY SIMILAR TO WHAT HAPPENED YESTERDAY/SATURDAY. HAVE 20-30%
CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS OVER THE IL RIVER
VALLEY MONDAY AFTERNOON. BEST CHANCES OF SHOWERS AND ISOLATED
THUNDERSTORMS IS MONDAY NIGHT STORM SYSTEM NEAR THE PACIFIC STATES
BRINGS A STRONGER COLD FRONT SE THROUGH IL. CHANCE OF SHOWERS
LINGERS TUE MORNING SE OF I-55 ESPECIALLY OVER SE IL THEN DRIER BY
TUE AFTERNOON WITH CLOUDS DECREASING TUE FROM NW TO SE. MUCH
COOLER HIGHS IN THE MID TO UPPER 50S WITH SE IL NEAR 60F...BUT
STILL ABOVE NORMAL HIGHS FOR EARLY DECEMBER IN THE LOWER TO MIDDLE
40S.
QUIET AND SEASONABLY COOL WEATHER EXPECTED TUE NIGHT THROUGH WED
NIGHT AS HIGH PRESSURE SETTLES INTO THE REGION. HIGHS WED IN THE
MID TO UPPER 40S...WITH SOME LOWER 50S SW AREAS.
LONG TERM...THURSDAY THROUGH SATURDAY NIGHT
EXTENDED MODELS HAVE TRENDED FURTHER SE WITH FRONTAL BOUNDARY NEAR
THE OHIO RIVER LATE THIS WEEK WITH OVERRUNNING RAIN CHANCES INTO
CENTRAL AND ESPECIALLY SE IL THU NIGHT INTO FRI NIGHT. ECMWF
MODELS CONTINUES QPF INTO CENTRAL/SE IL INTO SAT THOUGH THINK THIS
IS TOO FAR NORTH WITH MODELS TRENDING SOUTHWARD WITH THIS SYSTEM.
MOST OF THE PRECIPITATION APPEARS TO FALL AS RAIN BUT COULD HAVE
MIX DEVELOPING DURING FRI NIGHT ESPECIALLY NORTH OF I-70 AFTER
MIDNIGHT IF PRECIP LINGERS THAT LONG. HIGHS IN THE LOW TO MID 50S
THU GRADUALLY COOL CLOSER TO NORMAL BY NEXT WEEKEND.
07
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
215 PM EST SUN DEC 2 2012
.UPDATE...
THE LONG TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 1256 AM EST SUN DEC 2 2012
LOW PRESSURE OVER THE WESTERN GREAT LAKES WILL PUSH NORTHEAST
TODAY ALLOWING THE HIGH PRESSURE SYSTEM OVER THE CAROLINAS TO
CONTINUE TO PROVIDE A UNSEASONABLY WARM FLOW OF SOUTHERLY AIR TO
THE REGION. THIS PATTERN OF WARM SOUTHERLY WINDS IS EXPECTED TO
CONTINUE UNTIL LATE TUESDAY NIGHT WHEN A STRONGER COLD FRONT IS
EXPECTED TO PUSH ACROSS THE AREA...BRINGING OUR NEXT BEST CHANCE
FOR RAIN SHOWERS AND PERHAPS A THUNDERSTORM.
BEHIND THE FRONT...HIGH PRESSURE WILL BRING A RETURN TO MORE
SEASONABLE TEMPERATURES AND DRY WEATHER WEDNESDAY AND THURSDAY.
YET ANOTHER FRONTAL SYSTEM WILL BRING SHOWER CHANCES BACK BY
THURSDAY NIGHT.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 944 AM EST SUN DEC 2 2012
WEAK UPPER WAVE IS MOVING EAST OF THE AREA AND ALLOWING RAIN TO
COME TO AN END FROM WEST TO EAST. CLEARED RAIN OUT OF THE WESTERN
TO SOME CENTRAL COUNTIES FOR THE REST OF THE DAY. MAINTAINED SOME
SMALL CHANCES IN THE SOUTH AND EAST FOR THE NEXT FEW HOURS AND IN
THE FAR SOUTHEAST INTO THE AFTERNOON WITH THE RAP /WHICH HAS A
GOOD HANDLE ON THE CURRENT AREA OF PRECIPITATION/ SHOWING SOME
POTENTIAL FOR REDEVELOPMENT DOWN THERE WITH CONTINUED ISENTROPIC
LIFT. THIS LIFT SHOULD KEEP SKIES CLOUDY TO MOSTLY CLOUDY OVER THE
ENTIRE AREA TODAY AS WELL WITH THE POSSIBILITY OF A FEW PEAKS OF
SUNSHINE HERE AND THERE ACROSS THE WESTERN COUNTIES BUT EXPECT
THIS TO FILL BACK IN. WITH EXPECTED CLOUD COVER AND STEADY 850 MB
TEMPERATURES LOWERED HIGHS A FEW DEGREES IN THE CENTRAL AND
EASTERN COUNTIES SO LOW 60S EXPECTED THERE WITH MIDDLE 60S STILL
POSSIBLE IN THE WEST AND SOUTHWEST. WITHIN THE LOW CHANCE OF RAIN
SHOWERS TODAY ALSO CONTINUED TO INCLUDE ISOLATED THUNDERSTORMS
WITH ELEVATED INSTABILITY STILL AVAILABLE AND A FEW STRIKES
SHOWING UP THIS MORNING WITHIN THE SHOWER BANDS.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
ISSUED AT 1256 AM EST SUN DEC 2 2012
MAIN FORECAST CHALLENGE DURING THIS PERIOD WILL BE TEMPS UNTIL
LATE MONDAY NIGHT/EARLY TUESDAY AS WHICH TIME THE FOCUS WILL BE
POPS AS A STRONGER COLD FRONT PUSHES ACROSS THE STATE. MODELS
REMAIN IN PRETTY GOOD AGREEMENT WITH THE OVERALL PATTERN AND WILL
USE A BLEND.
LITTLE CHANGE IN THE PATTERN FOR TONIGHT AND MONDAY. ALOFT THE GFS
AND NAM BOTH ALLOW RIDGING TO DEVELOP DURING THIS TIME. SURFACE
FEATURE REMAIN IN PLACE...KEEPING THE WARM AIR ADVECTION AND
SOUTHERLY WINDS IN PLACE. MEANWHILE TIME HEIGHT SECTIONS AND
FORECAST SOUNDINGS ALSO CONTINUE TO KEEP RH/S HIGH IN THE LOWER
LEVELS. THUS WILL AIM FOR PERSISTENCE IN THE FORECAST
HERE...LOOKING FOR MOSTLY CLOUDY...AND WARM NIGHTS AND DAYS . WILL
CONTINUE TO TREND BOTH LOWS AND HIGHS WARMER THAN GUIDANCE AS THAT
HAS BEEN THE RESULT IN THIS PATTERN RECENTLY.
LATE ON MONDAY NIGHT BOTH THE GFS AND NAM SHOW A STRONGER COLD
FRONT PUSHING THROUGH THE AREA WITH BETTER DYNAMICS ALOFT. THE
300K GFS ISENTROPIC SURFACE IS MARGINAL...HOWEVER AN AXIS OF
MOISTURE IS PRESENT ALONG AND AHEAD OF THE FRONT AS SPECIFIC
HUMIDITIES PUSH OVER 5 G/KG. FORECAST SOUNDINGS SHOW DEEP
SATURATION AVAILABLE TOWARD 12Z TUESDAY. Q VECTORS SHOW GOOD LOWER
LEVEL CONVERGENCE. GIVEN THE EXPECTED CHANGE IN AIR MASS WILL
TREND POPS AT OR ABOVE MAVMOS. ONLY THE LACK OF ISENTROPIC FORCING
IS HOLDING ME BACK FROM RAISING POPS EVEN HIGHER. GIVEN THE
EXPECTED RAIN AND CLOUDS AND WARM AIR ADVECTION AHEAD OF THE FRONT
WILL TREND LOWS ON MONDAY NIGHT WARMER THAN MAVMOS.
STEADY OR SLOWLY FALLING TEMPS ARE EXPECTED ON TUESDAY AS THE COLD
FRONT LOOKS TO BE ON THE IND DOORSTEP NEAR 12Z. THE FRONT WILL
QUICKLY PROGRESSES EAST AND RESULT IN SLOWLY FALLING OR STEADY
TEMPS THROUGH MUCH OF THE DAY. MAY NEED TO KEEP SOME POPS DURING
THE AM HOURS TO ACCOUNT FOR ANY LINGERING PRECIP NEAR THE FRONT
AND FOR ANY TIMING DIFFERENCES THAT OCCUR IN THE MODELS OVER THE
NEXT FEW RUNS. THUS WILL STICK CLOSE WITH THE MAVMOS POPS...BUT
TREND TOWARD DRY WX QUICKLY BY 18Z TUESDAY AS MUCH DRIER AIR
ARRIVES IN THE AREA ASSOCIATED WITH THE INCOMING HIGH PRESSURE
SYSTEM. FURTHERMORE ALL FORCING SHOULD BE LONG GONE TO THE EAST BY
18Z.
DRY WEATHER IS EXPECTED ON TUESDAY NIGHT AS THE HIGH PRESSURE
SYSTEM SETTLES ACROSS THE AREA. FORECAST SOUNDINGS DRY OUT
DRAMATICALLY AS THE LOWER LEVEL FLOW BECOMES NORTHERLY AND COLD
AIR ADVECTION SET UP IS ON. WILL TREND COOLER THAN MEXMOS LOWS FOR
TUESDAY NIGHT.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
ISSUED AT 215 PM EST SUN DEC 2 2012
THE MAIN CHALLENGE IN THE LONG TERM WILL BE TIMING A COLD FRONT THAT
WILL BRING MORE SHOWERS TO CENTRAL INDIANA LATE IN THE WEEKEND.
THE 12Z CANADIAN SEEMS TO BE THE OUTLIER IN QUICKLY MOVING A COLD
FRONT SOUTHEAST ACROSS CENTRAL INDIANA THURSDAY NIGHT AND THEN
BUILDING HIGH PRESSURE IN ON FRIDAY. THE 00Z ECMWF...AND 12Z GEFS
AND GFS ARE MUCH SLOWER MOVING THE FRONT THROUGH ON FRIDAY. THEY
ALSO HAVE THE FRONT STALL NEAR THE OHIO RIVER FRIDAY NIGHT.
THEN...THE 12Z GEFS AND GFS DIFFER AS THEY BRING THE FRONT BACK
NORTH ACROSS CENTRAL INDIANA ON SUNDAY...WHILE THE EURO MOVES IT
INTO THE APPALACHIANS.
SO...PREFER THE 00Z ECMWF AND 12Z GEFS AND GFS WHICH SUGGESTS SHOWER
CHANCES THROUGH AT LEAST SATURDAY. THEN...WITH LOW CONDIDENCE IN
WHICH AMONG THE 00Z EURO AND 12Z GEFS AND GFS WILL VERIFY
BETTER...WILL ACCEPT THE REGIONAL INITIALIZATION WHICH HAS SMALL
POPS SUNDAY. TEMPERATURES FOR SUNDAY WILL ALSO BE PROBLEMATIC
DEPENDING ON WHERE THE FRONT LIES...AND FOR NOW WILL JUST ACCEPT
REGIONAL NUMBERS. OTHERWISE...REGIONAL NUMBERS LOOK OK STARTING OUT
AROUND NORMAL ON THURSDAY UNDER HIGH PRESSURE AND THEN BECOMING A
LITTLE ABOVE NORMAL IN SOUTHWEST FLOW AHEAD OF THE FRONT ON
THURSDAY. INITIALIZATION FOR THE REST OF THE PERIOD LOOKS OK TOO.
&&
.AVIATION /DISCUSSION FOR THE 02/18Z TAF ISSUANCE/...
ISSUED AT 1130 AM EST SUN DEC 2 2012
CEILINGS ARE TRENDING MVFR AND EXPECT THEM TO BE MOSTLY MVFR THROUGH
THE TAF PERIOD AS LOW LEVEL MOISTURE HANGS AROUND. WOULD NOT RULE
OUT LOWER STRATUS OR FOG TONIGHT WITH RECENT RAINS PER MOS...BUT NOT
CONFIDENT ENOUGH TO ADD AT THIS TIME. THE SHOWERS SHOULD BE OVER.
WINDS WILL BE SOUTHWEST AROUND 12 KNOTS WITH OCCASIONAL GUSTS TO 18
KNOTS PER NAM BUFKIT. LAF WILL PROBABLY NOT SEE ANY GUSTS WITH A
WEAKER SURFACE GRADIENT THERE. THE OTHER SITES WILL ALSO DROP BELOW
10 KNOTS AFTER 21Z AS THE GRADIENT CONTINUES TO WEAKEN.
HOWEVER...WINDS WILL PICK UP AGAIN AFTER 14Z TOMORROW AS THE
GRADIENT STRENGTHENS ONCE MORE IN ADVANCE OF A STRONG COLD FRONT.
WINDS WILL BECOME SOUTH NEAR 15Z KNOTS WITH GUSTS TO 20 KNOTS OR
MORE.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...PUMA
NEAR TERM...CP
SHORT TERM...PUMA
LONG TERM....MK
AVIATION...MK
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1130 AM EST SUN DEC 2 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 1256 AM EST SUN DEC 2 2012
LOW PRESSURE OVER THE WESTERN GREAT LAKES WILL PUSH NORTHEAST
TODAY ALLOWING THE HIGH PRESSURE SYSTEM OVER THE CAROLINAS TO
CONTINUE TO PROVIDE A UNSEASONABLY WARM FLOW OF SOUTHERLY AIR TO
THE REGION. THIS PATTERN OF WARM SOUTHERLY WINDS IS EXPECTED TO
CONTINUE UNTIL LATE TUESDAY NIGHT WHEN A STRONGER COLD FRONT IS
EXPECTED TO PUSH ACROSS THE AREA...BRINGING OUR NEXT BEST CHANCE
FOR RAIN SHOWERS AND PERHAPS A THUNDERSTORM.
BEHIND THE FRONT...HIGH PRESSURE WILL BRING A RETURN TO MORE
SEASONABLE TEMPERATURES AND DRY WEATHER WEDNESDAY AND THURSDAY.
YET ANOTHER FRONTAL SYSTEM WILL BRING SHOWER CHANCES BACK BY
THURSDAY NIGHT.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 944 AM EST SUN DEC 2 2012
WEAK UPPER WAVE IS MOVING EAST OF THE AREA AND ALLOWING RAIN TO
COME TO AN END FROM WEST TO EAST. CLEARED RAIN OUT OF THE WESTERN
TO SOME CENTRAL COUNTIES FOR THE REST OF THE DAY. MAINTAINED SOME
SMALL CHANCES IN THE SOUTH AND EAST FOR THE NEXT FEW HOURS AND IN
THE FAR SOUTHEAST INTO THE AFTERNOON WITH THE RAP /WHICH HAS A
GOOD HANDLE ON THE CURRENT AREA OF PRECIPITATION/ SHOWING SOME
POTENTIAL FOR REDEVELOPMENT DOWN THERE WITH CONTINUED ISENTROPIC
LIFT. THIS LIFT SHOULD KEEP SKIES CLOUDY TO MOSTLY CLOUDY OVER THE
ENTIRE AREA TODAY AS WELL WITH THE POSSIBILITY OF A FEW PEAKS OF
SUNSHINE HERE AND THERE ACROSS THE WESTERN COUNTIES BUT EXPECT
THIS TO FILL BACK IN. WITH EXPECTED CLOUD COVER AND STEADY 850 MB
TEMPERATURES LOWERED HIGHS A FEW DEGREES IN THE CENTRAL AND
EASTERN COUNTIES SO LOW 60S EXPECTED THERE WITH MIDDLE 60S STILL
POSSIBLE IN THE WEST AND SOUTHWEST. WITHIN THE LOW CHANCE OF RAIN
SHOWERS TODAY ALSO CONTINUED TO INCLUDE ISOLATED THUNDERSTORMS
WITH ELEVATED INSTABILITY STILL AVAILABLE AND A FEW STRIKES
SHOWING UP THIS MORNING WITHIN THE SHOWER BANDS.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
ISSUED AT 1256 AM EST SUN DEC 2 2012
MAIN FORECAST CHALLENGE DURING THIS PERIOD WILL BE TEMPS UNTIL
LATE MONDAY NIGHT/EARLY TUESDAY AS WHICH TIME THE FOCUS WILL BE
POPS AS A STRONGER COLD FRONT PUSHES ACROSS THE STATE. MODELS
REMAIN IN PRETTY GOOD AGREEMENT WITH THE OVERALL PATTERN AND WILL
USE A BLEND.
LITTLE CHANGE IN THE PATTERN FOR TONIGHT AND MONDAY. ALOFT THE GFS
AND NAM BOTH ALLOW RIDGING TO DEVELOP DURING THIS TIME. SURFACE
FEATURE REMAIN IN PLACE...KEEPING THE WARM AIR ADVECTION AND
SOUTHERLY WINDS IN PLACE. MEANWHILE TIME HEIGHT SECTIONS AND
FORECAST SOUNDINGS ALSO CONTINUE TO KEEP RH/S HIGH IN THE LOWER
LEVELS. THUS WILL AIM FOR PERSISTENCE IN THE FORECAST
HERE...LOOKING FOR MOSTLY CLOUDY...AND WARM NIGHTS AND DAYS . WILL
CONTINUE TO TREND BOTH LOWS AND HIGHS WARMER THAN GUIDANCE AS THAT
HAS BEEN THE RESULT IN THIS PATTERN RECENTLY.
LATE ON MONDAY NIGHT BOTH THE GFS AND NAM SHOW A STRONGER COLD
FRONT PUSHING THROUGH THE AREA WITH BETTER DYNAMICS ALOFT. THE
300K GFS ISENTROPIC SURFACE IS MARGINAL...HOWEVER AN AXIS OF
MOISTURE IS PRESENT ALONG AND AHEAD OF THE FRONT AS SPECIFIC
HUMIDITIES PUSH OVER 5 G/KG. FORECAST SOUNDINGS SHOW DEEP
SATURATION AVAILABLE TOWARD 12Z TUESDAY. Q VECTORS SHOW GOOD LOWER
LEVEL CONVERGENCE. GIVEN THE EXPECTED CHANGE IN AIR MASS WILL
TREND POPS AT OR ABOVE MAVMOS. ONLY THE LACK OF ISENTROPIC FORCING
IS HOLDING ME BACK FROM RAISING POPS EVEN HIGHER. GIVEN THE
EXPECTED RAIN AND CLOUDS AND WARM AIR ADVECTION AHEAD OF THE FRONT
WILL TREND LOWS ON MONDAY NIGHT WARMER THAN MAVMOS.
STEADY OR SLOWLY FALLING TEMPS ARE EXPECTED ON TUESDAY AS THE COLD
FRONT LOOKS TO BE ON THE IND DOORSTEP NEAR 12Z. THE FRONT WILL
QUICKLY PROGRESSES EAST AND RESULT IN SLOWLY FALLING OR STEADY
TEMPS THROUGH MUCH OF THE DAY. MAY NEED TO KEEP SOME POPS DURING
THE AM HOURS TO ACCOUNT FOR ANY LINGERING PRECIP NEAR THE FRONT
AND FOR ANY TIMING DIFFERENCES THAT OCCUR IN THE MODELS OVER THE
NEXT FEW RUNS. THUS WILL STICK CLOSE WITH THE MAVMOS POPS...BUT
TREND TOWARD DRY WX QUICKLY BY 18Z TUESDAY AS MUCH DRIER AIR
ARRIVES IN THE AREA ASSOCIATED WITH THE INCOMING HIGH PRESSURE
SYSTEM. FURTHERMORE ALL FORCING SHOULD BE LONG GONE TO THE EAST BY
18Z.
DRY WEATHER IS EXPECTED ON TUESDAY NIGHT AS THE HIGH PRESSURE
SYSTEM SETTLES ACROSS THE AREA. FORECAST SOUNDINGS DRY OUT
DRAMATICALLY AS THE LOWER LEVEL FLOW BECOMES NORTHERLY AND COLD
AIR ADVECTION SET UP IS ON. WILL TREND COOLER THAN MEXMOS LOWS FOR
TUESDAY NIGHT.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
ISSUED AT 329 AM EST SUN DEC 2 2012
THE LONG TERM PERIOD WILL START OUT DRY WITH HIGH PRESSURE IN
PLACE. HOWEVER...THE NEXT UPPER LEVEL SYSTEM AND ASSOCIATED COLD
FRONT ARE PROGGED FOR THURSDAY NIGHT/FRIDAY. AT THIS
TIME...INSTABILITY IS STILL LACKING...SO WILL NOT INCLUDE MENTION
OF THUNDER. LATEST INITIALIZATION CONTINUES TO BRING IN ABOVE
NORMAL TEMPS...SO DO NOT EXPECT ANY TYPE OF WINTRY PRECIP. MODELS
CONTINUE TO SHOW VARIABILITY...SO WILL NOT DEVIATE THIS FAR OUT.
&&
.AVIATION /DISCUSSION FOR THE 02/18Z TAF ISSUANCE/...
ISSUED AT 1130 AM EST SUN DEC 2 2012
CEILINGS ARE TRENDING MVFR AND EXPECT THEM TO BE MOSTLY MVFR THROUGH
THE TAF PERIOD AS LOW LEVEL MOISTURE HANGS AROUND. WOULD NOT RULE
OUT LOWER STRATUS OR FOG TONIGHT WITH RECENT RAINS PER MOS...BUT NOT
CONFIDENT ENOUGH TO ADD AT THIS TIME. THE SHOWERS SHOULD BE OVER.
WINDS WILL BE SOUTHWEST AROUND 12 KNOTS WITH OCCASIONAL GUSTS TO 18
KNOTS PER NAM BUFKIT. LAF WILL PROBABLY NOT SEE ANY GUSTS WITH A
WEAKER SURFACE GRADIENT THERE. THE OTHER SITES WILL ALSO DROP BELOW
10 KNOTS AFTER 21Z AS THE GRADIENT CONTINUES TO WEAKEN.
HOWEVER...WINDS WILL PICK UP AGAIN AFTER 14Z TOMORROW AS THE
GRADIENT STRENGTHENS ONCE MORE IN ADVANCE OF A STRONG COLD FRONT.
WINDS WILL BECOME SOUTH NEAR 15Z KNOTS WITH GUSTS TO 20 KNOTS OR
MORE.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...PUMA
NEAR TERM...CP
SHORT TERM...PUMA
LONG TERM....TDUD
AVIATION...MK
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
953 AM EST SUN DEC 2 2012
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 1256 AM EST SUN DEC 2 2012
LOW PRESSURE OVER THE WESTERN GREAT LAKES WILL PUSH NORTHEAST
TODAY ALLOWING THE HIGH PRESSURE SYSTEM OVER THE CAROLINAS TO
CONTINUE TO PROVIDE A UNSEASONABLY WARM FLOW OF SOUTHERLY AIR TO
THE REGION. THIS PATTERN OF WARM SOUTHERLY WINDS IS EXPECTED TO
CONTINUE UNTIL LATE TUESDAY NIGHT WHEN A STRONGER COLD FRONT IS
EXPECTED TO PUSH ACROSS THE AREA...BRINGING OUR NEXT BEST CHANCE
FOR RAIN SHOWERS AND PERHAPS A THUNDERSTORM.
BEHIND THE FRONT...HIGH PRESSURE WILL BRING A RETURN TO MORE
SEASONABLE TEMPERATURES AND DRY WEATHER WEDNESDAY AND THURSDAY.
YET ANOTHER FRONTAL SYSTEM WILL BRING SHOWER CHANCES BACK BY
THURSDAY NIGHT.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 944 AM EST SUN DEC 2 2012
WEAK UPPER WAVE IS MOVING EAST OF THE AREA AND ALLOWING RAIN TO
COME TO AN END FROM WEST TO EAST. CLEARED RAIN OUT OF THE WESTERN
TO SOME CENTRAL COUNTIES FOR THE REST OF THE DAY. MAINTAINED SOME
SMALL CHANCES IN THE SOUTH AND EAST FOR THE NEXT FEW HOURS AND IN
THE FAR SOUTHEAST INTO THE AFTERNOON WITH THE RAP /WHICH HAS A
GOOD HANDLE ON THE CURRENT AREA OF PRECIPITATION/ SHOWING SOME
POTENTIAL FOR REDEVELOPMENT DOWN THERE WITH CONTINUED ISENTROPIC
LIFT. THIS LIFT SHOULD KEEP SKIES CLOUDY TO MOSTLY CLOUDY OVER THE
ENTIRE AREA TODAY AS WELL WITH THE POSSIBILITY OF A FEW PEAKS OF
SUNSHINE HERE AND THERE ACROSS THE WESTERN COUNTIES BUT EXPECT
THIS TO FILL BACK IN. WITH EXPECTED CLOUD COVER AND STEADY 850 MB
TEMPERATURES LOWERED HIGHS A FEW DEGREES IN THE CENTRAL AND
EASTERN COUNTIES SO LOW 60S EXPECTED THERE WITH MIDDLE 60S STILL
POSSIBLE IN THE WEST AND SOUTHWEST. WITHIN THE LOW CHANCE OF RAIN
SHOWERS TODAY ALSO CONTINUED TO INCLUDE ISOLATED THUNDERSTORMS
WITH ELEVATED INSTABILITY STILL AVAILABLE AND A FEW STRIKES
SHOWING UP THIS MORNING WITHIN THE SHOWER BANDS.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
ISSUED AT 1256 AM EST SUN DEC 2 2012
MAIN FORECAST CHALLENGE DURING THIS PERIOD WILL BE TEMPS UNTIL
LATE MONDAY NIGHT/EARLY TUESDAY AS WHICH TIME THE FOCUS WILL BE
POPS AS A STRONGER COLD FRONT PUSHES ACROSS THE STATE. MODELS
REMAIN IN PRETTY GOOD AGREEMENT WITH THE OVERALL PATTERN AND WILL
USE A BLEND.
LITTLE CHANGE IN THE PATTERN FOR TONIGHT AND MONDAY. ALOFT THE GFS
AND NAM BOTH ALLOW RIDGING TO DEVELOP DURING THIS TIME. SURFACE
FEATURE REMAIN IN PLACE...KEEPING THE WARM AIR ADVECTION AND
SOUTHERLY WINDS IN PLACE. MEANWHILE TIME HEIGHT SECTIONS AND
FORECAST SOUNDINGS ALSO CONTINUE TO KEEP RH/S HIGH IN THE LOWER
LEVELS. THUS WILL AIM FOR PERSISTENCE IN THE FORECAST
HERE...LOOKING FOR MOSTLY CLOUDY...AND WARM NIGHTS AND DAYS . WILL
CONTINUE TO TREND BOTH LOWS AND HIGHS WARMER THAN GUIDANCE AS THAT
HAS BEEN THE RESULT IN THIS PATTERN RECENTLY.
LATE ON MONDAY NIGHT BOTH THE GFS AND NAM SHOW A STRONGER COLD
FRONT PUSHING THROUGH THE AREA WITH BETTER DYNAMICS ALOFT. THE
300K GFS ISENTROPIC SURFACE IS MARGINAL...HOWEVER AN AXIS OF
MOISTURE IS PRESENT ALONG AND AHEAD OF THE FRONT AS SPECIFIC
HUMIDITIES PUSH OVER 5 G/KG. FORECAST SOUNDINGS SHOW DEEP
SATURATION AVAILABLE TOWARD 12Z TUESDAY. Q VECTORS SHOW GOOD LOWER
LEVEL CONVERGENCE. GIVEN THE EXPECTED CHANGE IN AIR MASS WILL
TREND POPS AT OR ABOVE MAVMOS. ONLY THE LACK OF ISENTROPIC FORCING
IS HOLDING ME BACK FROM RAISING POPS EVEN HIGHER. GIVEN THE
EXPECTED RAIN AND CLOUDS AND WARM AIR ADVECTION AHEAD OF THE FRONT
WILL TREND LOWS ON MONDAY NIGHT WARMER THAN MAVMOS.
STEADY OR SLOWLY FALLING TEMPS ARE EXPECTED ON TUESDAY AS THE COLD
FRONT LOOKS TO BE ON THE IND DOORSTEP NEAR 12Z. THE FRONT WILL
QUICKLY PROGRESSES EAST AND RESULT IN SLOWLY FALLING OR STEADY
TEMPS THROUGH MUCH OF THE DAY. MAY NEED TO KEEP SOME POPS DURING
THE AM HOURS TO ACCOUNT FOR ANY LINGERING PRECIP NEAR THE FRONT
AND FOR ANY TIMING DIFFERENCES THAT OCCUR IN THE MODELS OVER THE
NEXT FEW RUNS. THUS WILL STICK CLOSE WITH THE MAVMOS POPS...BUT
TREND TOWARD DRY WX QUICKLY BY 18Z TUESDAY AS MUCH DRIER AIR
ARRIVES IN THE AREA ASSOCIATED WITH THE INCOMING HIGH PRESSURE
SYSTEM. FURTHERMORE ALL FORCING SHOULD BE LONG GONE TO THE EAST BY
18Z.
DRY WEATHER IS EXPECTED ON TUESDAY NIGHT AS THE HIGH PRESSURE
SYSTEM SETTLES ACROSS THE AREA. FORECAST SOUNDINGS DRY OUT
DRAMATICALLY AS THE LOWER LEVEL FLOW BECOMES NORTHERLY AND COLD
AIR ADVECTION SET UP IS ON. WILL TREND COOLER THAN MEXMOS LOWS FOR
TUESDAY NIGHT.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
ISSUED AT 329 AM EST SUN DEC 2 2012
THE LONG TERM PERIOD WILL START OUT DRY WITH HIGH PRESSURE IN
PLACE. HOWEVER...THE NEXT UPPER LEVEL SYSTEM AND ASSOCIATED COLD
FRONT ARE PROGGED FOR THURSDAY NIGHT/FRIDAY. AT THIS
TIME...INSTABILITY IS STILL LACKING...SO WILL NOT INCLUDE MENTION
OF THUNDER. LATEST INITIALIZATION CONTINUES TO BRING IN ABOVE
NORMAL TEMPS...SO DO NOT EXPECT ANY TYPE OF WINTRY PRECIP. MODELS
CONTINUE TO SHOW VARIABILITY...SO WILL NOT DEVIATE THIS FAR OUT.
&&
.AVIATION /DISCUSSION FOR THE 02/15Z TAF UPDATES/...
ISSUED AT 925 AM EST SUN DEC 2 2012
CEILINGS HAVE BEEN TRENDING BORDERLINE VFR AND MVFR AND MOS SUGGESTS
MVFR OR WORSE...SO WENT WITH MVFR TODAY...AND PULLED THE VICINITY
SHOWERS BASED ON RADAR TRENDS.
PREVIOUS DISCUSSION FOLLOWS...
MVFR/VFR HAVE BEEN THE PREVAILING CONDITIONS OVER THE LAST FEW
HOURS AS RAIN SHOWERS PASS THROUGH TAF SITES. MOST RAINFALL HAS
ALREADY MOVED EAST OF KLAF/KHUF/KIND...BUT DEEP LOW LEVEL MOISTURE
IN ITS WAKE WILL RESULT IN A PERSISTENT LOW STRATOCU DECK AND MVFR
CONDITIONS FOR THE REMAINDER OF TODAY.
AS WINDS WEAKEN AFTER SUNSET TONIGHT AND LOW LEVEL MOISTURE
REMAINS IN PLACE...CONDITIONS WILL WORSEN TO WIDESPREAD IFR
CATEGORY AT ALL TAF SITES DUE TO FOG DEVELOPMENT. POOR FLYING
CONDITIONS WILL PERSIST THROUGH TONIGHT.
LOW LEVEL WIND SHEAR IS STILL OVER THE NEXT FEW HOURS WITH 45-50KT
WINDS AT 1500 FT. THIS THREAT WILL SUBSIDE BY MID MORNING WHEN LOW
LEVEL JET SHIFTS EAST. AT THE SURFACE...WINDS WILL BE S/SW AT 10
TO 12 KTS TODAY AND THEN TAPER OFF THIS EVENING.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...PUMA
NEAR TERM...CP
SHORT TERM...PUMA
LONG TERM....TDUD
AVIATION...TDUD/MK
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
507 PM CST MON DEC 3 2012
.UPDATE...
A FORECAST UPDATE WAS SENT EARLY THIS PAST HOUR TO REFLECT A MUCH
LESS COVERAGE OF SHOWERS AND SHALLOW THUNDERSTORMS/CONVECTION. THE
EAST REMAINS THE MOST LIKELY AREA TO RECEIVE MEASURABLE RAIN...BUT
LOCATIONS WEST OF PRINCETON TO STERLING ARE LIKELY TO REMAIN WITH
TRACE AMOUNTS. AS FAR AS STRONG STORMS...WINDS ARE VEERING TO THE
SOUTHWEST...REDUCING SHEAR AT LOW LEVELS...THIS IS TRUE EXCEPT FOR
BUREAU AND PUTNAM COUNTIES...BUT BY THE TIME STORMS REACH
THERE...THEY MAY VEER AS WELL. WE REMAIN WATCH FULL...BUT FEEL THE
THREAT FOR A SEVERE EVENT IS VERY LOW AND CONFINED TO THE NEXT 1
HOUR...IN THE FAR EAST.
ERVIN
&&
.PREV DISCUSSION... /ISSUED 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.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1214 PM CST SUN DEC 2 2012
.UPDATE...
HAVE EXTENDED DENSE FOG ADVISORY UNTIL 19Z FOR FAR SOUTHEAST IA...
NORTHEAST MO AND PORTIONS OF WEST CENTRAL IL. MAY STILL SEE
SOME POCKETS OF DENSE FOG LINGER BEYOND BUT HOPEFULLY NOT
WIDESPREAD ENOUGH TO NECESSITATE CONTINUING EXTENSION OF THE
ADVISORY. ALSO... MADE ADJUSTMENTS TO HIGH TEMPS AND SKY COVER
GRIDS BASED ON CURRENT TRENDS.
&&
.AVIATION...
STRATUS AND FOG HOLDING ON AT KBRL AND KMLI WITH IFR TO LIFR
CONDITIONS. TRIED FOR SOME IMPROVEMENT AT BOTH SITES BY
MID TO LATE AFTN... BUT PROBABLY NO BETTER THAN MVFR AT BEST.
TNGT...EXPECT WIDESPREAD IFR/LIFR LOW CIGS AS LOW LEVEL FLOW
BECOMES SOUTHERLY ADVECTING THE CLOUDS NORTHWARD THROUGH THE
TERMINALS. ANTICIPATE FOG WITH AREAS OF DENSE FOG... BUT
QUITE CHALLENGING ON HOW WIDESPREAD VLIFR VSBYS AS MODELS DO
INDICATE INCREASING MSLP GRADIENT OVRNGT INTO MON AM AHEAD OF
THE NEXT FRONT. HAVE ONLY DENSE FOG MENTION AT KBRL FOR NOW
WHERE CONFIDENCE IS GREATEST BASED ON LIMITED IMPROVEMENT
REST OF TDY... VERY SMALL TEMP/DEWPT SPREADS AND LIGHT WINDS.
SOUTH WINDS AT 10-15 KTS WITH SOME GUSTS BY MID TO LATE MON AM
SHOULD BRING IMPROVEMENT TO VSBYS... ALTHOUGH ANTICIPATE
IFR TO LIFR CIGS TO LINGER.
&&
.PREV DISCUSSION... /ISSUED 1016 AM CST SUN DEC 2 2012/
UPDATE...
BASED ON OBSERVATIONS... SPOTTER REPORTS AND WEBCAMS... HAVE
EXTENDED THE DENSE FOG ADVISORY UNTIL 18Z. ALSO ADDED A FEW
COUNTIES OVER PORTIONS OF SOUTHEAST IA AND WEST CENTRAL IL.
BESIDES FOG... SLOWED THE CLEARING TREND FOR PORTIONS OF
SOUTHEAST IA... NORTHEAST MO AND WEST CENTRAL IL UNTIL MID TO
LATE AFTN AND POTENTIAL FOR SOME AREAS TO REMAIN CLOUDY ALL
DAY SOUTH WITH LIGHT WINDS/WEAK MIXING AND ABUNDANT MOISTURE.
PREV DISCUSSION... /ISSUED 559 AM CST SUN DEC 2 2012/
UPDATE...
THE LONE WEB CAM NEAR THE IA/MO BORDER INDICATES THICK FOG IN THE
AREA. KMPZ VISIBILITY IS DOWN AS IS KIRK. THUS DENSE FOG IS
OCCURRING IN VAN BUREN AND HENRY COUNTIES IN IOWA...AND PROBABLY
IN SCOTLAND/CLARK COUNTIES IN MISSOURI AND THE WESTERN PART OF LEE
COUNTY IN IOWA. THUS THE DENSE FOG ADVISORY WILL BE EXPANDED INTO
THESE AREAS AND WILL ALSO BE EXTENDED 1 HOUR EVERYWHERE.
A WEAK TROF IS MOVING THROUGH THE CENTRAL CWFA WHICH MAY BE
PARTIALLY RESPONSIBLE FOR THE INCREASE IN DENSE FOG DOWN SOUTH.
SATELLITE TRENDS CONTINUE TO SHOW STRONG SUBSIDENCE IN CENTRAL AND
WESTERN IOWA WHICH IS JUST BEGINNING TO ENTER THE FAR NORTHWEST
PART OF THE CWFA.
FOR THE MOST PART...THE GENERAL TREND OF THE FCST LOOKS TO BE ON
TRACK WITH CLEARING OCCURRING DURING THE DAY. ..08..
PREV DISCUSSION... /ISSUED 300 AM CST SUN DEC 2 2012/
SYNOPSIS...
06Z SFC ANALYSIS HAS A FRONT/BOUNDARY FROM ROUGHLY GREEN BAY BACK
TO THE NEBRASKA/KANSAS BORDER. ANOTHER FRONT RAN FROM A LOW NEAR
KSAW BACK TO AROUND KYKN. DEW POINTS OVER THE GREAT LAKES AND
MIDWEST WERE IN THE 40S AND 50S WITH 30S IN THE PLAINS.
SHORT TERM...TODAY AND TONIGHT
THE IMMEDIATE CONCERN IS FOG POTENTIAL AND THE CURRENT HEADLINES.
SATELLITE TRENDS SHOW GOOD SUBSIDENCE OVER NORTHWEST/WESTERN IOWA
WHICH HAS ALLOWED A LARGE EXPANSE OF DENSE FOG TO FORM IN THE
MOIST AIR. SAID FOG HAS EXPANDED EASTWARD IN THE LIGHT
WINDS/CONVERGENCE TO INCLUDE ROUGHLY THE NORTHWEST THIRD OF THE
CWFA. BASED ON CURRENT TRENDS WITH INPUT FROM THE RAP MODEL...THE
CURRENT FOG HEADLINES LOOK OK. HOWEVER...GIVEN THE EXTREMELY WARM
AND MOIST AIR OVER THE CWFA THERE IS REASONABLE POTENTIAL FOR
PATCHY IF NOT LOCALIZED AREAS OF FOG DEVELOPING AHEAD OF THE
CURRENT FOG HEADLINES ESPECIALLY IF CLEAR POCKETS DEVELOP IN THE
LOW CLOUDS.
THE OVERALL SUBSIDENCE INCREASES DURING THE DAY SO CLEARING IS
EXPECTED FROM WEST TO EAST DURING THE DAY. GIVEN THE EXCEPTIONALLY
MILD START...MAX TEMPERATURES WILL BE WELL ABOVE NORMAL FOR EARLY
DECEMBER. RECORD HIGHS APPEAR DOUBTFUL BUT KBRL MAY BE CLOSE BASED
ON PROJECTED MAX TEMPERATURES. A RECORD WARM LOW WILL NOT BE
REALIZED AT KDBQ BUT COULD OCCUR AT KMLI.
QUIET CONDITIONS WILL BE SEEN DURING THE EVENING ACROSS THE AREA.
THE WARM TEMPERATURES COMBINED WITH LIGHT WINDS AND INITIALLY
CLEAR OR NEARLY CLEAR SKIES SHOULD ALLOW PATCHY FOG TO DEVELOP BY
LATE EVENING ACROSS THE NORTHEAST QUADRANT OF THE CWFA.
AFTER MIDNIGHT...ANOTHER INFLUX OF MOISTURE WILL MOVE BACK INTO
THE AREA WHICH SHOULD INCLUDE CONSIDERABLE LOW CLOUDS. PATCHY FOG
SHOULD DEVELOP OVER MOST OF THE AREA. THE NORTHEAST QUADRANT OF
THE CWFA WILL HAVE LIGHT WINDS AND CLEAR SKIES THE LONGEST SO THE
FOG SHOULD BECOME MORE WIDESPREAD THERE. MIN TEMPERATURES TONIGHT
WILL BE ABOVE THE NORMAL MAX TEMPERATURES. ..08..
LONG TERM...MONDAY THROUGH SATURDAY
MODELS CONTINUE TO SHOW ZONAL FLOW OVER U.S. THROUGH MID WEEK WITH
SOME AMPLIFICATION IN THE FLOW DEVELOPING LATE WEEK AS A BROAD H5
TROF FORMS OVER THE WESTERN AND CENTRAL U.S.
IN THE NEAR TERM...RECORD OR NEAR RECORD WARMTH LOOKS ON TRACK FOR
MONDAY WITH THE MODELS IN GOOD AGREEMENT MOVING UNSEASONABLY WARM
AIR NORTH OUT OF THE SOUTHERN PLAINS INTO THE MID MISSISSIPPI
VALLEY AHEAD OF A COLD FRONT THAT SHOULD BE MOVING INTO THE
CENTRAL IA BY MID DAY. H8 TEMPS IN THE 10C TO 15C RANGE ARE
PROGGED TO BE OVER THE AREA MONDAY MORNING. A SURFACE WARM FRONT
SHOULD BE NEAR THE IA/MO BORDER EARLY MONDAY AND WILL MOVE NORTH
DURING THE DAY WITH SOUTH WINDS INCREASING INTO THE 15 TO 25 MPH
IN THE WARM SECTOR. ADDING SOME UNCERTAINTY TO THE WARM UP WILL BE
UNUSUALLY HIGH LOW LEVEL MOISTURE THAT WILL BE OVER AREA BY MONDAY
MORNING. THE MOIST LOW LEVELS SHOULD RESULT IN STRATUS AS WELL AS
SOME PATCHY DRIZZLE AND FOG DURING THE MORNING WHICH IS EXPECTED
TO MIX OUT SOME DURING THE DAY WITH INCREASING SOUTH WINDS. SOME
MOS GUIDANCE INCLUDING THE MET AND ECMWF MOS IS SUGGESTING
TEMPERATURES IN THE LOW 70S SOUTH TO MID 60S NORTH FOR HIGHS.
HOWEVER HAVE KEPT A DEGREE OR TWO UNDER THESE WARMER TEMPS DUE TO
THE UNCERTAINTY ABOUT THE EXTENT OF THE LOW CLOUD COVER.
REGARDLESS...IT WILL BE A VERY WARM DAY AND FORECAST HIGHS WILL BE
WITH IN A DEGREE OR TWO OF HIGH TEMPERATURE RECORDS FOR THE 3RD. IN
FACT FORECASTS HIGHS ARE WITHIN 5 OR SO DEGREES OF THE ALL TIME
RECORD HIGHS FOR THE MONTH OF DECEMBER. SEE THE CLIMATE SECTION
BELOW FOR DECEMBER 3RD RECORD HIGHS AND THE RECORD HIGHS FOR THE
MONTH OF DECEMBER.
THE FRONT AND ATTENDANT S/W WILL BRING ANOTHER CHANCE OF RAIN TO
THE AREA MAINLY MONDAY AFTERNOON AND EVENING. AS WITH THE SYSTEM
THAT MOVED THROUGH SATURDAY...THE MID LEVELS WILL BE DRY INITIALLY WITH
VERY LITTLE SATURATION EXPECTED. WITH THE BEST FORCING EXPECTED TO
MOVE THROUGH DURING THE EARLY EVENING HAVE KEPT LOW CHANCE POPS
FOR THE AFTERNOON AND 50 POPS EAST OF THE RIVER MONDAY EVENING.
SOME THUNDER EAST OF THE RIVER CAN/T BE RULED OUT AT THIS TIME BUT
FELT THE POTENTIAL WAS TOO LOW TO INCLUDE IN THE FORECAST FOR NOW.
RAINFALL AMOUNTS MONDAY AND MONDAY NIGHT SHOULD BE
LIGHT...GENERALLY LESS THAN A TENTH OF AN INCH.
QUIET WEATHER SHOULD BE OVER THE AREA TUESDAY AND WEDNESDAY AS
HIGH PRESSURE DOMINATES THE REGION. TEMPERATURES WILL COOL OFF
SOME FOR MID WEEK BUT WILL STILL BE ABOVE NORMAL.
THE NEXT SYSTEM WILL START TO IMPACT THE AREA BY WEDNESDAY NIGHT
AS A S/W CROSSES THE NORTHERN ROCKIES AND PUSHES A COLD FRONT INTO
THE NORTH CENTRAL STATES AND CENTRAL PLAINS BY THURSDAY MORNING.
HAVE GONE WITH SLIGHT CHANCE POPS FOR RAIN NORTHWEST LATE
WEDNESDAY NIGHT THEN CHANCE POPS THURSDAY AND THURSDAY NIGHT AS
THE SYSTEM MOVES THROUGH. THE ECMWF AND GFS ARE IN GOOD AGREEMENT
WITH A BROAD UPPER TROF SETTING UP OVER THE CENTRAL U.S. FOR THE
END OF THE WEEK AND PLACING A BAROCLINIC ZONE OVER THE AREA.
BECAUSE OF THIS SOME LOW POPS WERE HELD ONTO FOR THE SOUTHERN CWFA
INTO FRIDAY NIGHT. TEMPERATURES MAY BE COLD ENOUGH BY FRIDAY NIGHT
TO PRODUCE SOME MIXED PRECIPITATION. THE DEVELOPING UPPER TROF
SHOULD BRING NEAR NORMAL TEMPERATURES TO THE REGION FOR THE END OF
THE WEEK.
DLF
CLIMATE...
RECORD HIGHS FOR DECEMBER 2...
MOLINE.........65 IN 1982
CEDAR RAPIDS...66 IN 1962
DUBUQUE........62 IN 1982
BURLINGTON.....66 IN 1962
RECORD WARM LOWS FOR DECEMBER 2...
MOLINE.........49 IN 1913
RECORD HIGHS FOR DECEMBER 3...
MOLINE.........69 IN 1970
CEDAR RAPIDS...64 IN 1998
DUBUQUE........64 IN 1970
BURLINGTON.....71 IN 1970
MONTHLY RECORD HIGH...
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...DENSE FOG ADVISORY UNTIL 1 PM CST THIS AFTERNOON FOR LEE-VAN
BUREN.
IL...DENSE FOG ADVISORY UNTIL 1 PM CST THIS AFTERNOON FOR HANCOCK-
MCDONOUGH.
MO...DENSE FOG ADVISORY UNTIL 1 PM CST THIS AFTERNOON FOR CLARK-
SCOTLAND.
&&
$$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1144 AM CST SUN DEC 2 2012
.SHORT TERM /TODAY/...
FOG HAS BEGUN TO DISSIPATE ACROSS THE FAR
NORTHWEST WITH SOME DRY AIR MOVING INTO THE STATE AS A WEAK BOUNDARY
SAGS SOUTH. VISIBILITY HAS IMPROVED TO ABOVE ADVISORY LEVEL AND THUS
CANCELLED OUT THE NORTHWEST CORNER OF THE FORECAST AREA. THE DRIER
AIR LOOKS TO CONTINUE TO ADVECT FURTHER SOUTHEAST AND MASON CITY TO
FORT DODGE SHOWING SIGNS OF IMPROVEMENT AS WELL.
FORECAST SOUNDINGS DEPICTING VERY WEAK MIXING TODAY...SO FOG WILL
TAKE ITS TIME DISSIPATING THIS MORNING. MODELS SHOWING THE WEAK
BOUNDARY TO CONTINUE TO MOVE SOUTH THROUGH THE MORNING HOURS BUT
WASH OUT BY THIS AFTERNOON WITH WEAK RETURN FLOW. THIS SHOULD BE
ENOUGH TO HELP BURN OFF ANY REMAINING FOG ACROSS THE SOUTH THIS
MORNING. THE LATEST HRRR HAS FOG PERSISTING THROUGH THE EARLY
AFTERNOON HOURS AND SO KEPT MENTION OF PATCHY FOG THROUGH 18Z IN THE
SOUTH. WITH THE WARM START TODAY...TEMPS WILL BE WELL ABOVE NORMAL
AGAIN TODAY. WENT AT OR SLIGHTLY WARMER THAN THE NAM FOR MAX TEMPS
TODAY AND MAY GET EVEN WARMER DEPENDING ON TIMING OF FOG BURNING OFF
THIS MORNING.
.LONG TERM.../TONIGHT THROUGH SATURDAY/
NON DIURNAL TEMPERATURES ARE EXPECTED TONIGHT. THE DRIER DEWPOINTS
DROPPING INTO CENTRAL IOWA EARLY THIS MORNING WILL GIVE WAY TO
ANOTHER STRONG SURGE OF LOW LEVEL THETA-E ADVECTION PRIMARILY AFTER
MIDNIGHT. LOW TEMPERATURES SHOULD OCCUR BEFORE MIDNIGHT THEN RISING
TEMPERATURES AFTER THAT TIME. ADVECTION FOG WILL BE A CONCERN AGAIN
AS HIGHER DEWPOINTS IN THE MID 40S TO MID 50S ARRIVE AND OVERRUN THE
SFC WITH UPPER LEVEL SOIL TEMPERATURES IN THE MID 30S TO NEAR 40.
SOME OF THIS FOG COULD BE DENSE THROUGH MID MONDAY MORNING.
TEMPERATURES FOR MONDAY STILL UNCERTAIN AND WILL MIRROR THE SKY
CONDITIONS. DESPITE THE VERY WARM 850 MB TEMPERATURES OF +10C AND
ABOVE...COLD ADVECTION WILL BE ARRIVING BELOW THIS LEVEL AROUND 900
MB AND WILL ENHANCE THE INVERSION AND LIMIT MIXING DEPTH. SOUTHWEST
WINDS WILL INCREASE AHEAD OF THE APPROACHING COOL FRONT (CANT CALL
IT COLD BECAUSE TEMPERATURES WILL REMAIN ABOVE NORMAL AFTER
PASSAGE). THE INCREASING SOUTHWEST WINDS SHOULD HELP SCATTER THE
STRATUS/FOG FROM A PORTION OF THE AREA MAINLY WEST CENTRAL AND
SOUTHWEST. TEMPERATURES WILL FALL DURING THE AFTERNOON WITH THE
FRONTAL PASSAGE AND A SWITCH TO NORTHWEST WINDS. PRECIPITATION
CHANCES WILL BE LIMITED TO PATCHES OF DRIZZLE AND POSSIBLE VERY
LIGHT RAIN WITH THE CHANCE OF MEASURABLE PRECIPITATION LOW.
MONDAY NIGHT WILL BE MILD (NEARLY 10 DEGREES ABOVE NORMAL) WITH A
WARM NOSE AND INVERSION REMAINING AROUND 950 MB. A MUCH DRIER
AIRMASS WILL BE IN PLACE ON TUESDAY ALONG WITH WEST TO NORTHWEST
DOWNSLOPE FLOW. THIS WILL BE CONDUCIVE TO WARMING AND HIGHS BACK
INTO THE LOW TO MID 50S MOST LOCATIONS. A STRONG UPPER WAVE WILL
PASS THROUGH THE NORTHERN GREAT LAKES AND ONTARIO REGION TUESDAY AND
TUESDAY NIGHT. THIS SYSTEM WILL SWING A COLD FRONT THROUGH IOWA
TUESDAY NIGHT. THE NAM IS MUCH MORE AGGRESSIVE ON THE AMOUNT SHALLOW
NEAR SFC COLD AIR WILL ARRIVE WITH THE SYSTEM. THE NAM TENDS TO
CATCH THESE LOW LEVEL COLD INTRUSIONS AND HAVE LEANED CLOSER TO THIS
SOLUTION. HIGH PRESSURE WILL FOLLOW TUESDAY NIGHT THEN SHIFT OFF TO
THE EAST ON WEDNESDAY LEADING TO A QUICK RETURN TO SOUTHERLY FLOW.
INCREASING THETA-E ADVECTION WEDNESDAY WILL BRING INCREASING MID
LEVEL CLOUDS. THE CLOUDS COULD PUT A DAMPER ON TEMPERATURES
WEDNESDAY IF THEY ARRIVE EARLY ENOUGH...FOR NOW HAVE TRENDED
TEMPERATURES TOWARD A LATER ARRIVAL.
THE REMAINDER OF THE EXTENDED IS DEPENDENT ON THE GRADUAL EROSION OF
THE ZONAL FLOW AND THE EVOLUTION OF A DEVELOPING LONG WAVE TROUGH
AND THE ASSOCIATED IMPENDING ARRIVAL OF COLDER WEATHER. THE TRENDS
POINT TO A RETURN TO MORE NORMAL TEMPERATURES SHOULD BEGIN BY
FRIDAY. HINTS AT WINTER WEATHER ON THE HORIZON WITH THE GFS AND
ECMWF EACH CONTINUING TO SUGGEST SNOW POTENTIAL SOMETIME IN THE DAY
7-10 RANGE.
&&
.AVIATION...02/18Z
COLD FRONT BECOMING NEARLY STATIONARY NEAR A KDBQ-JUST SOUTH OF KDSM
TO SOUTH OF KOMA LINE WILL BEGIN TO LIFT NORTH AS A WARM FRONT
TONIGHT. SLOW IMPROVEMENT IS EXPECTED ACROSS THE SOUTHERN HALF OF
IOWA THIS AFTERNOON...BUT THE SOUTHERN TAFS MAY HAVE TROUBLE
IMPROVING BEYOND MVFR. WIDESPREAD IFR/LIFR CIGS EXPECTED TONIGHT.
EXPERIMENTAL WRF SIMULATIONS CAPTURE THE TREND WELL AND HAVE TIMING
CLOSE TO WHAT IS IN THE TAFS FRO THE REFORMATION OF THE STRATUS.
WITH BOUNDARY LAYER TEMPS AROUND 20 KTS AND H8 WINDS 35 TO 40
KTS...DO NOT EXPECT AS MUCH DENSE FOG...BUT STRATUS WILL BE VERY
EXTENSIVE WITH CONDITIONS NOT IMPROVING BEFORE LATE MON MORNING.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR
ADAIR-ADAMS-APPANOOSE-AUDUBON-BLACK HAWK-BOONE-BREMER-
BUTLER-CALHOUN-CARROLL-CASS-CERRO GORDO-CLARKE-CRAWFORD-DALLAS-
DAVIS-DECATUR-FRANKLIN-GREENE-GRUNDY-GUTHRIE-HAMILTON-
HANCOCK-HARDIN-HUMBOLDT-JASPER-LUCAS-MADISON-MAHASKA-MARION-
MARSHALL-MONROE-POLK-POWESHIEK-RINGGOLD-SAC-STORY-TAMA-
TAYLOR-UNION-WAPELLO-WARREN-WAYNE-WEBSTER-WINNEBAGO-WORTH-WRIGHT.
&&
$$
SHORT TERM...MS DEC 12
LONG TERM...DONAVON
AVIATION...MS DEC 12
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1016 AM CST SUN DEC 2 2012
.UPDATE...
BASED ON OBSERVATIONS... SPOTTER REPORTS AND WEBCAMS... HAVE
EXTENDED THE DENSE FOG ADVISORY UNTIL 18Z. ALSO ADDED A FEW
COUNTIES OVER PORTIONS OF SOUTHEAST IA AND WEST CENTRAL IL.
BESIDES FOG... SLOWED THE CLEARING TREND FOR PORTIONS OF
SOUTHEAST IA... NORTHEAST MO AND WEST CENTRAL IL UNTIL MID TO
LATE AFTN AND POTENTIAL FOR SOME AREAS TO REMAIN CLOUDY ALL
DAY SOUTH WITH LIGHT WINDS/WEAK MIXING AND ABUNDANT MOISTURE.
&&
.PREV DISCUSSION... /ISSUED 559 AM CST SUN DEC 2 2012/
UPDATE...
THE LONE WEB CAM NEAR THE IA/MO BORDER INDICATES THICK FOG IN THE
AREA. KMPZ VISIBILITY IS DOWN AS IS KIRK. THUS DENSE FOG IS
OCCURRING IN VAN BUREN AND HENRY COUNTIES IN IOWA...AND PROBABLY
IN SCOTLAND/CLARK COUNTIES IN MISSOURI AND THE WESTERN PART OF LEE
COUNTY IN IOWA. THUS THE DENSE FOG ADVISORY WILL BE EXPANDED INTO
THESE AREAS AND WILL ALSO BE EXTENDED 1 HOUR EVERYWHERE.
A WEAK TROF IS MOVING THROUGH THE CENTRAL CWFA WHICH MAY BE
PARTIALLY RESPONSIBLE FOR THE INCREASE IN DENSE FOG DOWN SOUTH.
SATELLITE TRENDS CONTINUE TO SHOW STRONG SUBSIDENCE IN CENTRAL AND
WESTERN IOWA WHICH IS JUST BEGINNING TO ENTER THE FAR NORTHWEST
PART OF THE CWFA.
FOR THE MOST PART...THE GENERAL TREND OF THE FCST LOOKS TO BE ON
TRACK WITH CLEARING OCCURRING DURING THE DAY. ..08..
AVIATION...
CONDITIONS RANGE FROM VLIFR TO MVFR WITH LOW CLOUDS/FOG.
CONDITIONS WILL SLOWLY IMPROVE TO VFR WITH MOST OF THE IMPROVEMENT
OCCURRING AFT 15Z/02. AS HIGH PRESSURE MOVES THROUGH THE AREA
WINDS WILL REMAIN LIGHT/VARIABLE. BASED ON WHAT IS BEING
SUGGESTED BY MODEL TRENDS...MINIMALLY MVFR CONDITIONS WILL MOVE
BACK INTO EASTERN IOWA AND NORTHERN ILLINOIS AFT 04Z/03. ..08..
PREV DISCUSSION... /ISSUED 300 AM CST SUN DEC 2 2012/
SYNOPSIS...
06Z SFC ANALYSIS HAS A FRONT/BOUNDARY FROM ROUGHLY GREEN BAY BACK
TO THE NEBRASKA/KANSAS BORDER. ANOTHER FRONT RAN FROM A LOW NEAR
KSAW BACK TO AROUND KYKN. DEW POINTS OVER THE GREAT LAKES AND
MIDWEST WERE IN THE 40S AND 50S WITH 30S IN THE PLAINS.
SHORT TERM...TODAY AND TONIGHT
THE IMMEDIATE CONCERN IS FOG POTENTIAL AND THE CURRENT HEADLINES.
SATELLITE TRENDS SHOW GOOD SUBSIDENCE OVER NORTHWEST/WESTERN IOWA
WHICH HAS ALLOWED A LARGE EXPANSE OF DENSE FOG TO FORM IN THE
MOIST AIR. SAID FOG HAS EXPANDED EASTWARD IN THE LIGHT
WINDS/CONVERGENCE TO INCLUDE ROUGHLY THE NORTHWEST THIRD OF THE
CWFA. BASED ON CURRENT TRENDS WITH INPUT FROM THE RAP MODEL...THE
CURRENT FOG HEADLINES LOOK OK. HOWEVER...GIVEN THE EXTREMELY WARM
AND MOIST AIR OVER THE CWFA THERE IS REASONABLE POTENTIAL FOR
PATCHY IF NOT LOCALIZED AREAS OF FOG DEVELOPING AHEAD OF THE
CURRENT FOG HEADLINES ESPECIALLY IF CLEAR POCKETS DEVELOP IN THE
LOW CLOUDS.
THE OVERALL SUBSIDENCE INCREASES DURING THE DAY SO CLEARING IS
EXPECTED FROM WEST TO EAST DURING THE DAY. GIVEN THE EXCEPTIONALLY
MILD START...MAX TEMPERATURES WILL BE WELL ABOVE NORMAL FOR EARLY
DECEMBER. RECORD HIGHS APPEAR DOUBTFUL BUT KBRL MAY BE CLOSE BASED
ON PROJECTED MAX TEMPERATURES. A RECORD WARM LOW WILL NOT BE
REALIZED AT KDBQ BUT COULD OCCUR AT KMLI.
QUIET CONDITIONS WILL BE SEEN DURING THE EVENING ACROSS THE AREA.
THE WARM TEMPERATURES COMBINED WITH LIGHT WINDS AND INITIALLY
CLEAR OR NEARLY CLEAR SKIES SHOULD ALLOW PATCHY FOG TO DEVELOP BY
LATE EVENING ACROSS THE NORTHEAST QUADRANT OF THE CWFA.
AFTER MIDNIGHT...ANOTHER INFLUX OF MOISTURE WILL MOVE BACK INTO
THE AREA WHICH SHOULD INCLUDE CONSIDERABLE LOW CLOUDS. PATCHY FOG
SHOULD DEVELOP OVER MOST OF THE AREA. THE NORTHEAST QUADRANT OF
THE CWFA WILL HAVE LIGHT WINDS AND CLEAR SKIES THE LONGEST SO THE
FOG SHOULD BECOME MORE WIDESPREAD THERE. MIN TEMPERATURES TONIGHT
WILL BE ABOVE THE NORMAL MAX TEMPERATURES. ..08..
LONG TERM...MONDAY THROUGH SATURDAY
MODELS CONTINUE TO SHOW ZONAL FLOW OVER U.S. THROUGH MID WEEK WITH
SOME AMPLIFICATION IN THE FLOW DEVELOPING LATE WEEK AS A BROAD H5
TROF FORMS OVER THE WESTERN AND CENTRAL U.S.
IN THE NEAR TERM...RECORD OR NEAR RECORD WARMTH LOOKS ON TRACK FOR
MONDAY WITH THE MODELS IN GOOD AGREEMENT MOVING UNSEASONABLY WARM
AIR NORTH OUT OF THE SOUTHERN PLAINS INTO THE MID MISSISSIPPI
VALLEY AHEAD OF A COLD FRONT THAT SHOULD BE MOVING INTO THE
CENTRAL IA BY MID DAY. H8 TEMPS IN THE 10C TO 15C RANGE ARE
PROGGED TO BE OVER THE AREA MONDAY MORNING. A SURFACE WARM FRONT
SHOULD BE NEAR THE IA/MO BORDER EARLY MONDAY AND WILL MOVE NORTH
DURING THE DAY WITH SOUTH WINDS INCREASING INTO THE 15 TO 25 MPH
IN THE WARM SECTOR. ADDING SOME UNCERTAINTY TO THE WARM UP WILL BE
UNUSUALLY HIGH LOW LEVEL MOISTURE THAT WILL BE OVER AREA BY MONDAY
MORNING. THE MOIST LOW LEVELS SHOULD RESULT IN STRATUS AS WELL AS
SOME PATCHY DRIZZLE AND FOG DURING THE MORNING WHICH IS EXPECTED
TO MIX OUT SOME DURING THE DAY WITH INCREASING SOUTH WINDS. SOME
MOS GUIDANCE INCLUDING THE MET AND ECMWF MOS IS SUGGESTING
TEMPERATURES IN THE LOW 70S SOUTH TO MID 60S NORTH FOR HIGHS.
HOWEVER HAVE KEPT A DEGREE OR TWO UNDER THESE WARMER TEMPS DUE TO
THE UNCERTAINTY ABOUT THE EXTENT OF THE LOW CLOUD COVER.
REGARDLESS...IT WILL BE A VERY WARM DAY AND FORECAST HIGHS WILL BE
WITH IN A DEGREE OR TWO OF HIGH TEMPERATURE RECORDS FOR THE 3RD. IN
FACT FORECASTS HIGHS ARE WITHIN 5 OR SO DEGREES OF THE ALL TIME
RECORD HIGHS FOR THE MONTH OF DECEMBER. SEE THE CLIMATE SECTION
BELOW FOR DECEMBER 3RD RECORD HIGHS AND THE RECORD HIGHS FOR THE
MONTH OF DECEMBER.
THE FRONT AND ATTENDANT S/W WILL BRING ANOTHER CHANCE OF RAIN TO
THE AREA MAINLY MONDAY AFTERNOON AND EVENING. AS WITH THE SYSTEM
THAT MOVED THROUGH SATURDAY...THE MID LEVELS WILL BE DRY INITIALLY WITH
VERY LITTLE SATURATION EXPECTED. WITH THE BEST FORCING EXPECTED TO
MOVE THROUGH DURING THE EARLY EVENING HAVE KEPT LOW CHANCE POPS
FOR THE AFTERNOON AND 50 POPS EAST OF THE RIVER MONDAY EVENING.
SOME THUNDER EAST OF THE RIVER CAN/T BE RULED OUT AT THIS TIME BUT
FELT THE POTENTIAL WAS TOO LOW TO INCLUDE IN THE FORECAST FOR NOW.
RAINFALL AMOUNTS MONDAY AND MONDAY NIGHT SHOULD BE
LIGHT...GENERALLY LESS THAN A TENTH OF AN INCH.
QUIET WEATHER SHOULD BE OVER THE AREA TUESDAY AND WEDNESDAY AS
HIGH PRESSURE DOMINATES THE REGION. TEMPERATURES WILL COOL OFF
SOME FOR MID WEEK BUT WILL STILL BE ABOVE NORMAL.
THE NEXT SYSTEM WILL START TO IMPACT THE AREA BY WEDNESDAY NIGHT
AS A S/W CROSSES THE NORTHERN ROCKIES AND PUSHES A COLD FRONT INTO
THE NORTH CENTRAL STATES AND CENTRAL PLAINS BY THURSDAY MORNING.
HAVE GONE WITH SLIGHT CHANCE POPS FOR RAIN NORTHWEST LATE
WEDNESDAY NIGHT THEN CHANCE POPS THURSDAY AND THURSDAY NIGHT AS
THE SYSTEM MOVES THROUGH. THE ECMWF AND GFS ARE IN GOOD AGREEMENT
WITH A BROAD UPPER TROF SETTING UP OVER THE CENTRAL U.S. FOR THE
END OF THE WEEK AND PLACING A BAROCLINIC ZONE OVER THE AREA.
BECAUSE OF THIS SOME LOW POPS WERE HELD ONTO FOR THE SOUTHERN CWFA
INTO FRIDAY NIGHT. TEMPERATURES MAY BE COLD ENOUGH BY FRIDAY NIGHT
TO PRODUCE SOME MIXED PRECIPITATION. THE DEVELOPING UPPER TROF
SHOULD BRING NEAR NORMAL TEMPERATURES TO THE REGION FOR THE END OF
THE WEEK.
DLF
CLIMATE...
RECORD HIGHS FOR DECEMBER 2...
MOLINE.........65 IN 1982
CEDAR RAPIDS...66 IN 1962
DUBUQUE........62 IN 1982
BURLINGTON.....66 IN 1962
RECORD WARM LOWS FOR DECEMBER 2...
MOLINE.........49 IN 1913
RECORD HIGHS FOR DECEMBER 3...
MOLINE.........69 IN 1970
CEDAR RAPIDS...64 IN 1998
DUBUQUE........64 IN 1970
BURLINGTON.....71 IN 1970
MONTHLY RECORD HIGH...
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...DENSE FOG ADVISORY UNTIL NOON CST TODAY FOR BENTON-BUCHANAN-
DELAWARE-DES MOINES-DUBUQUE-HENRY IA-IOWA-JEFFERSON-JOHNSON-
JONES-KEOKUK-LEE-LINN-VAN BUREN-WASHINGTON.
IL...DENSE FOG ADVISORY UNTIL NOON CST TODAY FOR HANCOCK-HENDERSON-
MCDONOUGH-WARREN.
MO...DENSE FOG ADVISORY UNTIL NOON CST TODAY FOR CLARK-SCOTLAND.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
559 AM CST SUN DEC 2 2012
.UPDATE...
THE LONE WEB CAM NEAR THE IA/MO BORDER INDICATES THICK FOG IN THE
AREA. KMPZ VISIBILITY IS DOWN AS IS KIRK. THUS DENSE FOG IS
OCCURRING IN VAN BUREN AND HENRY COUNTIES IN IOWA...AND PROBABLY
IN SCOTLAND/CLARK COUNTIES IN MISSOURI AND THE WESTERN PART OF LEE
COUNTY IN IOWA. THUS THE DENSE FOG ADVISORY WILL BE EXPANDED INTO
THESE AREAS AND WILL ALSO BE EXTENDED 1 HOUR EVERYWHERE.
A WEAK TROF IS MOVING THROUGH THE CENTRAL CWFA WHICH MAY BE
PARTIALLY RESPONSIBLE FOR THE INCREASE IN DENSE FOG DOWN SOUTH.
SATELLITE TRENDS CONTINUE TO SHOW STRONG SUBSIDENCE IN CENTRAL AND
WESTERN IOWA WHICH IS JUST BEGINNING TO ENTER THE FAR NORTHWEST
PART OF THE CWFA.
FOR THE MOST PART...THE GENERAL TREND OF THE FCST LOOKS TO BE ON
TRACK WITH CLEARING OCCURRING DURING THE DAY. ..08..
&&
.AVIATION...
CONDITIONS RANGE FROM VLIFR TO MVFR WITH LOW CLOUDS/FOG.
CONDITIONS WILL SLOWLY IMPROVE TO VFR WITH MOST OF THE IMPROVEMENT
OCCURRING AFT 15Z/02. AS HIGH PRESSURE MOVES THROUGH THE AREA
WINDS WILL REMAIN LIGHT/VARIABLE. BASED ON WHAT IS BEING
SUGGESTED BY MODEL TRENDS...MINIMALLY MVFR CONDITIONS WILL MOVE
BACK INTO EASTERN IOWA AND NORTHERN ILLINOIS AFT 04Z/03. ..08..
&&
.PREV DISCUSSION... /ISSUED 300 AM CST SUN DEC 2 2012/
SYNOPSIS...
06Z SFC ANALYSIS HAS A FRONT/BOUNDARY FROM ROUGHLY GREEN BAY BACK
TO THE NEBRASKA/KANSAS BORDER. ANOTHER FRONT RAN FROM A LOW NEAR
KSAW BACK TO AROUND KYKN. DEW POINTS OVER THE GREAT LAKES AND
MIDWEST WERE IN THE 40S AND 50S WITH 30S IN THE PLAINS.
SHORT TERM...TODAY AND TONIGHT
THE IMMEDIATE CONCERN IS FOG POTENTIAL AND THE CURRENT HEADLINES.
SATELLITE TRENDS SHOW GOOD SUBSIDENCE OVER NORTHWEST/WESTERN IOWA
WHICH HAS ALLOWED A LARGE EXPANSE OF DENSE FOG TO FORM IN THE
MOIST AIR. SAID FOG HAS EXPANDED EASTWARD IN THE LIGHT
WINDS/CONVERGENCE TO INCLUDE ROUGHLY THE NORTHWEST THIRD OF THE
CWFA. BASED ON CURRENT TRENDS WITH INPUT FROM THE RAP MODEL...THE
CURRENT FOG HEADLINES LOOK OK. HOWEVER...GIVEN THE EXTREMELY WARM
AND MOIST AIR OVER THE CWFA THERE IS REASONABLE POTENTIAL FOR
PATCHY IF NOT LOCALIZED AREAS OF FOG DEVELOPING AHEAD OF THE
CURRENT FOG HEADLINES ESPECIALLY IF CLEAR POCKETS DEVELOP IN THE
LOW CLOUDS.
THE OVERALL SUBSIDENCE INCREASES DURING THE DAY SO CLEARING IS
EXPECTED FROM WEST TO EAST DURING THE DAY. GIVEN THE EXCEPTIONALLY
MILD START...MAX TEMPERATURES WILL BE WELL ABOVE NORMAL FOR EARLY
DECEMBER. RECORD HIGHS APPEAR DOUBTFUL BUT KBRL MAY BE CLOSE BASED
ON PROJECTED MAX TEMPERATURES. A RECORD WARM LOW WILL NOT BE
REALIZED AT KDBQ BUT COULD OCCUR AT KMLI.
QUIET CONDITIONS WILL BE SEEN DURING THE EVENING ACROSS THE AREA.
THE WARM TEMPERATURES COMBINED WITH LIGHT WINDS AND INITIALLY
CLEAR OR NEARLY CLEAR SKIES SHOULD ALLOW PATCHY FOG TO DEVELOP BY
LATE EVENING ACROSS THE NORTHEAST QUADRANT OF THE CWFA.
AFTER MIDNIGHT...ANOTHER INFLUX OF MOISTURE WILL MOVE BACK INTO
THE AREA WHICH SHOULD INCLUDE CONSIDERABLE LOW CLOUDS. PATCHY FOG
SHOULD DEVELOP OVER MOST OF THE AREA. THE NORTHEAST QUADRANT OF
THE CWFA WILL HAVE LIGHT WINDS AND CLEAR SKIES THE LONGEST SO THE
FOG SHOULD BECOME MORE WIDESPREAD THERE. MIN TEMPERATURES TONIGHT
WILL BE ABOVE THE NORMAL MAX TEMPERATURES. ..08..
LONG TERM...MONDAY THROUGH SATURDAY
MODELS CONTINUE TO SHOW ZONAL FLOW OVER U.S. THROUGH MID WEEK WITH
SOME AMPLIFICATION IN THE FLOW DEVELOPING LATE WEEK AS A BROAD H5
TROF FORMS OVER THE WESTERN AND CENTRAL U.S.
IN THE NEAR TERM...RECORD OR NEAR RECORD WARMTH LOOKS ON TRACK FOR
MONDAY WITH THE MODELS IN GOOD AGREEMENT MOVING UNSEASONABLY WARM
AIR NORTH OUT OF THE SOUTHERN PLAINS INTO THE MID MISSISSIPPI
VALLEY AHEAD OF A COLD FRONT THAT SHOULD BE MOVING INTO THE
CENTRAL IA BY MID DAY. H8 TEMPS IN THE 10C TO 15C RANGE ARE
PROGGED TO BE OVER THE AREA MONDAY MORNING. A SURFACE WARM FRONT
SHOULD BE NEAR THE IA/MO BORDER EARLY MONDAY AND WILL MOVE NORTH
DURING THE DAY WITH SOUTH WINDS INCREASING INTO THE 15 TO 25 MPH
IN THE WARM SECTOR. ADDING SOME UNCERTAINTY TO THE WARM UP WILL BE
UNUSUALLY HIGH LOW LEVEL MOISTURE THAT WILL BE OVER AREA BY MONDAY
MORNING. THE MOIST LOW LEVELS SHOULD RESULT IN STRATUS AS WELL AS
SOME PATCHY DRIZZLE AND FOG DURING THE MORNING WHICH IS EXPECTED
TO MIX OUT SOME DURING THE DAY WITH INCREASING SOUTH WINDS. SOME
MOS GUIDANCE INCLUDING THE MET AND ECMWF MOS IS SUGGESTING
TEMPERATURES IN THE LOW 70S SOUTH TO MID 60S NORTH FOR HIGHS.
HOWEVER HAVE KEPT A DEGREE OR TWO UNDER THESE WARMER TEMPS DUE TO
THE UNCERTAINTY ABOUT THE EXTENT OF THE LOW CLOUD COVER.
REGARDLESS...IT WILL BE A VERY WARM DAY AND FORECAST HIGHS WILL BE
WITH IN A DEGREE OR TWO OF HIGH TEMPERATURE RECORDS FOR THE 3RD. IN
FACT FORECASTS HIGHS ARE WITHIN 5 OR SO DEGREES OF THE ALL TIME
RECORD HIGHS FOR THE MONTH OF DECEMBER. SEE THE CLIMATE SECTION
BELOW FOR DECEMBER 3RD RECORD HIGHS AND THE RECORD HIGHS FOR THE
MONTH OF DECEMBER.
THE FRONT AND ATTENDANT S/W WILL BRING ANOTHER CHANCE OF RAIN TO
THE AREA MAINLY MONDAY AFTERNOON AND EVENING. AS WITH THE SYSTEM
THAT MOVED THROUGH SATURDAY...THE MID LEVELS WILL BE DRY INITIALLY WITH
VERY LITTLE SATURATION EXPECTED. WITH THE BEST FORCING EXPECTED TO
MOVE THROUGH DURING THE EARLY EVENING HAVE KEPT LOW CHANCE POPS
FOR THE AFTERNOON AND 50 POPS EAST OF THE RIVER MONDAY EVENING.
SOME THUNDER EAST OF THE RIVER CAN/T BE RULED OUT AT THIS TIME BUT
FELT THE POTENTIAL WAS TOO LOW TO INCLUDE IN THE FORECAST FOR NOW.
RAINFALL AMOUNTS MONDAY AND MONDAY NIGHT SHOULD BE
LIGHT...GENERALLY LESS THAN A TENTH OF AN INCH.
QUIET WEATHER SHOULD BE OVER THE AREA TUESDAY AND WEDNESDAY AS
HIGH PRESSURE DOMINATES THE REGION. TEMPERATURES WILL COOL OFF
SOME FOR MID WEEK BUT WILL STILL BE ABOVE NORMAL.
THE NEXT SYSTEM WILL START TO IMPACT THE AREA BY WEDNESDAY NIGHT
AS A S/W CROSSES THE NORTHERN ROCKIES AND PUSHES A COLD FRONT INTO
THE NORTH CENTRAL STATES AND CENTRAL PLAINS BY THURSDAY MORNING.
HAVE GONE WITH SLIGHT CHANCE POPS FOR RAIN NORTHWEST LATE
WEDNESDAY NIGHT THEN CHANCE POPS THURSDAY AND THURSDAY NIGHT AS
THE SYSTEM MOVES THROUGH. THE ECMWF AND GFS ARE IN GOOD AGREEMENT
WITH A BROAD UPPER TROF SETTING UP OVER THE CENTRAL U.S. FOR THE
END OF THE WEEK AND PLACING A BAROCLINIC ZONE OVER THE AREA.
BECAUSE OF THIS SOME LOW POPS WERE HELD ONTO FOR THE SOUTHERN CWFA
INTO FRIDAY NIGHT. TEMPERATURES MAY BE COLD ENOUGH BY FRIDAY NIGHT
TO PRODUCE SOME MIXED PRECIPITATION. THE DEVELOPING UPPER TROF
SHOULD BRING NEAR NORMAL TEMPERATURES TO THE REGION FOR THE END OF
THE WEEK.
DLF
CLIMATE...
RECORD HIGHS FOR DECEMBER 2...
MOLINE.........65 IN 1982
CEDAR RAPIDS...66 IN 1962
DUBUQUE........62 IN 1982
BURLINGTON.....66 IN 1962
RECORD WARM LOWS FOR DECEMBER 2...
MOLINE.........49 IN 1913
RECORD HIGHS FOR DECEMBER 3...
MOLINE.........69 IN 1970
CEDAR RAPIDS...64 IN 1998
DUBUQUE........64 IN 1970
BURLINGTON.....71 IN 1970
MONTHLY RECORD HIGH...
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...DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR BENTON-
BUCHANAN-DELAWARE-DUBUQUE-HENRY IA-IOWA-JEFFERSON-JOHNSON-
JONES-KEOKUK-LEE-LINN-VAN BUREN-WASHINGTON.
IL...NONE.
MO...DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR CLARK-
SCOTLAND.
&&
$$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
540 AM CST SUN DEC 2 2012
...UPDATED AVIATION DISCUSSION...
.SHORT TERM /TODAY/...
FOG HAS BEGUN TO DISSIPATE ACROSS THE FAR
NORTHWEST WITH SOME DRY AIR MOVING INTO THE STATE AS A WEAK BOUNDARY
SAGS SOUTH. VISIBILITY HAS IMPROVED TO ABOVE ADVISORY LEVEL AND THUS
CANCELLED OUT THE NORTHWEST CORNER OF THE FORECAST AREA. THE DRIER
AIR LOOKS TO CONTINUE TO ADVECT FURTHER SOUTHEAST AND MASON CITY TO
FORT DODGE SHOWING SIGNS OF IMPROVEMENT AS WELL.
FORECAST SOUNDINGS DEPICTING VERY WEAK MIXING TODAY...SO FOG WILL
TAKE ITS TIME DISSIPATING THIS MORNING. MODELS SHOWING THE WEAK
BOUNDARY TO CONTINUE TO MOVE SOUTH THROUGH THE MORNING HOURS BUT
WASH OUT BY THIS AFTERNOON WITH WEAK RETURN FLOW. THIS SHOULD BE
ENOUGH TO HELP BURN OFF ANY REMAINING FOG ACROSS THE SOUTH THIS
MORNING. THE LATEST HRRR HAS FOG PERSISTING THROUGH THE EARLY
AFTERNOON HOURS AND SO KEPT MENTION OF PATCHY FOG THROUGH 18Z IN THE
SOUTH. WITH THE WARM START TODAY...TEMPS WILL BE WELL ABOVE NORMAL
AGAIN TODAY. WENT AT OR SLIGHTLY WARMER THAN THE NAM FOR MAX TEMPS
TODAY AND MAY GET EVEN WARMER DEPENDING ON TIMING OF FOG BURNING OFF
THIS MORNING.
.LONG TERM.../TONIGHT THROUGH SATURDAY/
NON DIURNAL TEMPERATURES ARE EXPECTED TONIGHT. THE DRIER DEWPOINTS
DROPPING INTO CENTRAL IOWA EARLY THIS MORNING WILL GIVE WAY TO
ANOTHER STRONG SURGE OF LOW LEVEL THETA-E ADVECTION PRIMARILY AFTER
MIDNIGHT. LOW TEMPERATURES SHOULD OCCUR BEFORE MIDNIGHT THEN RISING
TEMPERATURES AFTER THAT TIME. ADVECTION FOG WILL BE A CONCERN AGAIN
AS HIGHER DEWPOINTS IN THE MID 40S TO MID 50S ARRIVE AND OVERRUN THE
SFC WITH UPPER LEVEL SOIL TEMPERATURES IN THE MID 30S TO NEAR 40.
SOME OF THIS FOG COULD BE DENSE THROUGH MID MONDAY MORNING.
TEMPERATURES FOR MONDAY STILL UNCERTAIN AND WILL MIRROR THE SKY
CONDITIONS. DESPITE THE VERY WARM 850 MB TEMPERATURES OF +10C AND
ABOVE...COLD ADVECTION WILL BE ARRIVING BELOW THIS LEVEL AROUND 900
MB AND WILL ENHANCE THE INVERSION AND LIMIT MIXING DEPTH. SOUTHWEST
WINDS WILL INCREASE AHEAD OF THE APPROACHING COOL FRONT (CANT CALL
IT COLD BECAUSE TEMPERATURES WILL REMAIN ABOVE NORMAL AFTER
PASSAGE). THE INCREASING SOUTHWEST WINDS SHOULD HELP SCATTER THE
STRATUS/FOG FROM A PORTION OF THE AREA MAINLY WEST CENTRAL AND
SOUTHWEST. TEMPERATURES WILL FALL DURING THE AFTERNOON WITH THE
FRONTAL PASSAGE AND A SWITCH TO NORTHWEST WINDS. PRECIPITATION
CHANCES WILL BE LIMITED TO PATCHES OF DRIZZLE AND POSSIBLE VERY
LIGHT RAIN WITH THE CHANCE OF MEASURABLE PRECIPITATION LOW.
MONDAY NIGHT WILL BE MILD (NEARLY 10 DEGREES ABOVE NORMAL) WITH A
WARM NOSE AND INVERSION REMAINING AROUND 950 MB. A MUCH DRIER
AIRMASS WILL BE IN PLACE ON TUESDAY ALONG WITH WEST TO NORTHWEST
DOWNSLOPE FLOW. THIS WILL BE CONDUCIVE TO WARMING AND HIGHS BACK
INTO THE LOW TO MID 50S MOST LOCATIONS. A STRONG UPPER WAVE WILL
PASS THROUGH THE NORTHERN GREAT LAKES AND ONTARIO REGION TUESDAY AND
TUESDAY NIGHT. THIS SYSTEM WILL SWING A COLD FRONT THROUGH IOWA
TUESDAY NIGHT. THE NAM IS MUCH MORE AGGRESSIVE ON THE AMOUNT SHALLOW
NEAR SFC COLD AIR WILL ARRIVE WITH THE SYSTEM. THE NAM TENDS TO
CATCH THESE LOW LEVEL COLD INTRUSIONS AND HAVE LEANED CLOSER TO THIS
SOLUTION. HIGH PRESSURE WILL FOLLOW TUESDAY NIGHT THEN SHIFT OFF TO
THE EAST ON WEDNESDAY LEADING TO A QUICK RETURN TO SOUTHERLY FLOW.
INCREASING THETA-E ADVECTION WEDNESDAY WILL BRING INCREASING MID
LEVEL CLOUDS. THE CLOUDS COULD PUT A DAMPER ON TEMPERATURES
WEDNESDAY IF THEY ARRIVE EARLY ENOUGH...FOR NOW HAVE TRENDED
TEMPERATURES TOWARD A LATER ARRIVAL.
THE REMAINDER OF THE EXTENDED IS DEPENDENT ON THE GRADUAL EROSION OF
THE ZONAL FLOW AND THE EVOLUTION OF A DEVELOPING LONG WAVE TROUGH
AND THE ASSOCIATED IMPENDING ARRIVAL OF COLDER WEATHER. THE TRENDS
POINT TO A RETURN TO MORE NORMAL TEMPERATURES SHOULD BEGIN BY
FRIDAY. HINTS AT WINTER WEATHER ON THE HORIZON WITH THE GFS AND
ECMWF EACH CONTINUING TO SUGGEST SNOW POTENTIAL SOMETIME IN THE DAY
7-10 RANGE.
&&
.AVIATION...02/12Z
LIFR/IFR VIS/CIGS DUE TO THE THICK FOG WILL CONTINUE TO PLAGUE
DSM/ALO/OTM OVER THE NEXT COUPLE OF HOURS...THEN LIFTING TO MVFR BY
15Z. HAVE VFR CONDITIONS AT ALL TAF SITES BY 18Z...BUT CHANCE THERE
MAY BE SOME LINGERING MVFR VIS AT DSM/OTM. SOME DRIER AIR HAS CAUSED
THE FOG TO LIFT AT FOD/MCW BUT MAY STILL RECEIVE IFR VIS THROUGH 13Z
AT FOD. ANOTHER ROUND OF FOG IS LIKELY TO DEVELOP PAST 06Z MONDAY
WITH THE BOUNDARY LAYER MOISTURE REMAINING AND FAIRLY STRONG
INVERSION DEVELOPING. HAVE MVFR VIS MENTIONED TOWARDS THE END OF THE
FORECAST.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR
ADAIR-ADAMS-APPANOOSE-AUDUBON-BLACK HAWK-BOONE-BREMER-
BUTLER-CALHOUN-CARROLL-CASS-CERRO GORDO-CLARKE-CRAWFORD-DALLAS-
DAVIS-DECATUR-FRANKLIN-GREENE-GRUNDY-GUTHRIE-HAMILTON-
HANCOCK-HARDIN-HUMBOLDT-JASPER-LUCAS-MADISON-MAHASKA-MARION-
MARSHALL-MONROE-POLK-POWESHIEK-RINGGOLD-SAC-STORY-TAMA-
TAYLOR-UNION-WAPELLO-WARREN-WAYNE-WEBSTER-WINNEBAGO-WORTH-WRIGHT.
&&
$$
SHORT TERM...PODRAZIK
LONG TERM...DONAVON
AVIATION...PODRAZIK
AREA FORECAST DISCUSSION
NWS DES MOINES IA
350 AM CST SUN DEC 2 2012
.SHORT TERM /TODAY/...
FOG HAS BEGUN TO DISSIPATE ACROSS THE FAR
NORTHWEST WITH SOME DRY AIR MOVING INTO THE STATE AS A WEAK BOUNDARY
SAGS SOUTH. VISIBILITY HAS IMPROVED TO ABOVE ADVISORY LEVEL AND THUS
CANCELLED OUT THE NORTHWEST CORNER OF THE FORECAST AREA. THE DRIER
AIR LOOKS TO CONTINUE TO ADVECT FURTHER SOUTHEAST AND MASON CITY TO
FORT DODGE SHOWING SIGNS OF IMPROVEMENT AS WELL.
FORECAST SOUNDINGS DEPICTING VERY WEAK MIXING TODAY...SO FOG WILL
TAKE ITS TIME DISSIPATING THIS MORNING. MODELS SHOWING THE WEAK
BOUNDARY TO CONTINUE TO MOVE SOUTH THROUGH THE MORNING HOURS BUT
WASH OUT BY THIS AFTERNOON WITH WEAK RETURN FLOW. THIS SHOULD BE
ENOUGH TO HELP BURN OFF ANY REMAINING FOG ACROSS THE SOUTH THIS
MORNING. THE LATEST HRRR HAS FOG PERSISTING THROUGH THE EARLY
AFTERNOON HOURS AND SO KEPT MENTION OF PATCHY FOG THROUGH 18Z IN THE
SOUTH. WITH THE WARM START TODAY...TEMPS WILL BE WELL ABOVE NORMAL
AGAIN TODAY. WENT AT OR SLIGHTLY WARMER THAN THE NAM FOR MAX TEMPS
TODAY AND MAY GET EVEN WARMER DEPENDING ON TIMING OF FOG BURNING OFF
THIS MORNING.
.LONG TERM.../TONIGHT THROUGH SATURDAY/
NON DIURNAL TEMPERATURES ARE EXPECTED TONIGHT. THE DRIER DEWPOINTS
DROPPING INTO CENTRAL IOWA EARLY THIS MORNING WILL GIVE WAY TO
ANOTHER STRONG SURGE OF LOW LEVEL THETA-E ADVECTION PRIMARILY AFTER
MIDNIGHT. LOW TEMPERATURES SHOULD OCCUR BEFORE MIDNIGHT THEN RISING
TEMPERATURES AFTER THAT TIME. ADVECTION FOG WILL BE A CONCERN AGAIN
AS HIGHER DEWPOINTS IN THE MID 40S TO MID 50S ARRIVE AND OVERRUN THE
SFC WITH UPPER LEVEL SOIL TEMPERATURES IN THE MID 30S TO NEAR 40.
SOME OF THIS FOG COULD BE DENSE THROUGH MID MONDAY MORNING.
TEMPERATURES FOR MONDAY STILL UNCERTAIN AND WILL MIRROR THE SKY
CONDITIONS. DESPITE THE VERY WARM 850 MB TEMPERATURES OF +10C AND
ABOVE...COLD ADVECTION WILL BE ARRIVING BELOW THIS LEVEL AROUND 900
MB AND WILL ENHANCE THE INVERSION AND LIMIT MIXING DEPTH. SOUTHWEST
WINDS WILL INCREASE AHEAD OF THE APPROACHING COOL FRONT (CANT CALL
IT COLD BECAUSE TEMPERATURES WILL REMAIN ABOVE NORMAL AFTER
PASSAGE). THE INCREASING SOUTHWEST WINDS SHOULD HELP SCATTER THE
STRATUS/FOG FROM A PORTION OF THE AREA MAINLY WEST CENTRAL AND
SOUTHWEST. TEMPERATURES WILL FALL DURING THE AFTERNOON WITH THE
FRONTAL PASSAGE AND A SWITCH TO NORTHWEST WINDS. PRECIPITATION
CHANCES WILL BE LIMITED TO PATCHES OF DRIZZLE AND POSSIBLE VERY
LIGHT RAIN WITH THE CHANCE OF MEASURABLE PRECIPITATION LOW.
MONDAY NIGHT WILL BE MILD (NEARLY 10 DEGREES ABOVE NORMAL) WITH A
WARM NOSE AND INVERSION REMAINING AROUND 950 MB. A MUCH DRIER
AIRMASS WILL BE IN PLACE ON TUESDAY ALONG WITH WEST TO NORTHWEST
DOWNSLOPE FLOW. THIS WILL BE CONDUCIVE TO WARMING AND HIGHS BACK
INTO THE LOW TO MID 50S MOST LOCATIONS. A STRONG UPPER WAVE WILL
PASS THROUGH THE NORTHERN GREAT LAKES AND ONTARIO REGION TUESDAY AND
TUESDAY NIGHT. THIS SYSTEM WILL SWING A COLD FRONT THROUGH IOWA
TUESDAY NIGHT. THE NAM IS MUCH MORE AGGRESSIVE ON THE AMOUNT SHALLOW
NEAR SFC COLD AIR WILL ARRIVE WITH THE SYSTEM. THE NAM TENDS TO
CATCH THESE LOW LEVEL COLD INTRUSIONS AND HAVE LEANED CLOSER TO THIS
SOLUTION. HIGH PRESSURE WILL FOLLOW TUESDAY NIGHT THEN SHIFT OFF TO
THE EAST ON WEDNESDAY LEADING TO A QUICK RETURN TO SOUTHERLY FLOW.
INCREASING THETA-E ADVECTION WEDNESDAY WILL BRING INCREASING MID
LEVEL CLOUDS. THE CLOUDS COULD PUT A DAMPER ON TEMPERATURES
WEDNESDAY IF THEY ARRIVE EARLY ENOUGH...FOR NOW HAVE TRENDED
TEMPERATURES TOWARD A LATER ARRIVAL.
THE REMAINDER OF THE EXTENDED IS DEPENDENT ON THE GRADUAL EROSION OF
THE ZONAL FLOW AND THE EVOLUTION OF A DEVELOPING LONG WAVE TROUGH
AND THE ASSOCIATED IMPENDING ARRIVAL OF COLDER WEATHER. THE TRENDS
POINT TO A RETURN TO MORE NORMAL TEMPERATURES SHOULD BEGIN BY
FRIDAY. HINTS AT WINTER WEATHER ON THE HORIZON WITH THE GFS AND
ECMWF EACH CONTINUING TO SUGGEST SNOW POTENTIAL SOMETIME IN THE DAY
7-10 RANGE.
&&
.AVIATION...02/06Z
AREAS OF DENSE FOG HAVE DEVELOPED ACROSS CENTRAL IOWA...AFFECTING
ALL SITES. EXPECT VISIBILITIES AND CEILINGS TO BE RESTRICTED DUE TO
FG AND BR THROUGH 12Z WITH IFR AND LIFR CONDITIONS. CEILINGS AND
VISIBILITIES MAY BE VARIABLE AT TIMES RETURNING TO VFR AND MVFR.
HOWEVER...PREVAILING CONDITIONS WILL BE IFR AND LIFR THROUGH 12Z.
CONDITIONS WILL GRADUALLY IMPROVE AFTER 12Z...WITH VFR CONDITIONS AT
SITES NEAR 18Z. COULD AGAIN SEE BR DEVELOPMENT AT SITES AFTER 00Z
TOWARDS END OF PERIOD...BUT DO NOT HAVE ENOUGH CONFIDENCE TO INCLUDE
MENTION ATTM.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR
ADAIR-ADAMS-APPANOOSE-AUDUBON-BLACK HAWK-BOONE-BREMER-
BUTLER-CALHOUN-CARROLL-CASS-CERRO GORDO-CLARKE-CRAWFORD-DALLAS-
DAVIS-DECATUR-FRANKLIN-GREENE-GRUNDY-GUTHRIE-HAMILTON-
HANCOCK-HARDIN-HUMBOLDT-JASPER-LUCAS-MADISON-MAHASKA-MARION-
MARSHALL-MONROE-POLK-POWESHIEK-RINGGOLD-SAC-STORY-TAMA-
TAYLOR-UNION-WAPELLO-WARREN-WAYNE-WEBSTER-WINNEBAGO-WORTH-WRIGHT.
&&
$$
SHORT TERM...PODRAZIK
LONG TERM...DONAVON
AVIATION...AWB
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
300 AM CST SUN DEC 2 2012
.SYNOPSIS...
06Z SFC ANALYSIS HAS A FRONT/BOUNDARY FROM ROUGHLY GREEN BAY BACK
TO THE NEBRASKA/KANSAS BORDER. ANOTHER FRONT RAN FROM A LOW NEAR
KSAW BACK TO AROUND KYKN. DEW POINTS OVER THE GREAT LAKES AND
MIDWEST WERE IN THE 40S AND 50S WITH 30S IN THE PLAINS.
&&
.SHORT TERM...TODAY AND TONIGHT
THE IMMEDIATE CONCERN IS FOG POTENTIAL AND THE CURRENT HEADLINES.
SATELLITE TRENDS SHOW GOOD SUBSIDENCE OVER NORTHWEST/WESTERN IOWA
WHICH HAS ALLOWED A LARGE EXPANSE OF DENSE FOG TO FORM IN THE
MOIST AIR. SAID FOG HAS EXPANDED EASTWARD IN THE LIGHT
WINDS/CONVERGENCE TO INCLUDE ROUGHLY THE NORTHWEST THIRD OF THE
CWFA. BASED ON CURRENT TRENDS WITH INPUT FROM THE RAP MODEL...THE
CURRENT FOG HEADLINES LOOK OK. HOWEVER...GIVEN THE EXTREMELY WARM
AND MOIST AIR OVER THE CWFA THERE IS REASONABLE POTENTIAL FOR
PATCHY IF NOT LOCALIZED AREAS OF FOG DEVELOPING AHEAD OF THE
CURRENT FOG HEADLINES ESPECIALLY IF CLEAR POCKETS DEVELOP IN THE
LOW CLOUDS.
THE OVERALL SUBSIDENCE INCREASES DURING THE DAY SO CLEARING IS
EXPECTED FROM WEST TO EAST DURING THE DAY. GIVEN THE EXCEPTIONALLY
MILD START...MAX TEMPERATURES WILL BE WELL ABOVE NORMAL FOR EARLY
DECEMBER. RECORD HIGHS APPEAR DOUBTFUL BUT KBRL MAY BE CLOSE BASED
ON PROJECTED MAX TEMPERATURES. A RECORD WARM LOW WILL NOT BE
REALIZED AT KDBQ BUT COULD OCCUR AT KMLI.
QUIET CONDITIONS WILL BE SEEN DURING THE EVENING ACROSS THE AREA.
THE WARM TEMPERATURES COMBINED WITH LIGHT WINDS AND INITIALLY
CLEAR OR NEARLY CLEAR SKIES SHOULD ALLOW PATCHY FOG TO DEVELOP BY
LATE EVENING ACROSS THE NORTHEAST QUADRANT OF THE CWFA.
AFTER MIDNIGHT...ANOTHER INFLUX OF MOISTURE WILL MOVE BACK INTO
THE AREA WHICH SHOULD INCLUDE CONSIDERABLE LOW CLOUDS. PATCHY FOG
SHOULD DEVELOP OVER MOST OF THE AREA. THE NORTHEAST QUADRANT OF
THE CWFA WILL HAVE LIGHT WINDS AND CLEAR SKIES THE LONGEST SO THE
FOG SHOULD BECOME MORE WIDESPREAD THERE. MIN TEMPERATURES TONIGHT
WILL BE ABOVE THE NORMAL MAX TEMPERATURES. ..08..
.LONG TERM...MONDAY THROUGH SATURDAY
MODELS CONTINUE TO SHOW ZONAL FLOW OVER U.S. THROUGH MID WEEK WITH
SOME AMPLIFICATION IN THE FLOW DEVELOPING LATE WEEK AS A BROAD H5
TROF FORMS OVER THE WESTERN AND CENTRAL U.S.
IN THE NEAR TERM...RECORD OR NEAR RECORD WARMTH LOOKS ON TRACK FOR
MONDAY WITH THE MODELS IN GOOD AGREEMENT MOVING UNSEASONABLY WARM
AIR NORTH OUT OF THE SOUTHERN PLAINS INTO THE MID MISSISSIPPI
VALLEY AHEAD OF A COLD FRONT THAT SHOULD BE MOVING INTO THE
CENTRAL IA BY MID DAY. H8 TEMPS IN THE 10C TO 15C RANGE ARE
PROGGED TO BE OVER THE AREA MONDAY MORNING. A SURFACE WARM FRONT
SHOULD BE NEAR THE IA/MO BORDER EARLY MONDAY AND WILL MOVE NORTH
DURING THE DAY WITH SOUTH WINDS INCREASING INTO THE 15 TO 25 MPH
IN THE WARM SECTOR. ADDING SOME UNCERTAINTY TO THE WARM UP WILL BE
UNUSUALLY HIGH LOW LEVEL MOISTURE THAT WILL BE OVER AREA BY MONDAY
MORNING. THE MOIST LOW LEVELS SHOULD RESULT IN STRATUS AS WELL AS
SOME PATCHY DRIZZLE AND FOG DURING THE MORNING WHICH IS EXPECTED
TO MIX OUT SOME DURING THE DAY WITH INCREASING SOUTH WINDS. SOME
MOS GUIDANCE INCLUDING THE MET AND ECMWF MOS IS SUGGESTING
TEMPERATURES IN THE LOW 70S SOUTH TO MID 60S NORTH FOR HIGHS.
HOWEVER HAVE KEPT A DEGREE OR TWO UNDER THESE WARMER TEMPS DUE TO
THE UNCERTAINTY ABOUT THE EXTENT OF THE LOW CLOUD COVER.
REGARDLESS...IT WILL BE A VERY WARM DAY AND FORECAST HIGHS WILL BE
WITH IN A DEGREE OR TWO OF HIGH TEMPERATURE RECORDS FOR THE 3RD. IN
FACT FORECASTS HIGHS ARE WITHIN 5 OR SO DEGREES OF THE ALL TIME
RECORD HIGHS FOR THE MONTH OF DECEMBER. SEE THE CLIMATE SECTION
BELOW FOR DECEMBER 3RD RECORD HIGHS AND THE RECORD HIGHS FOR THE
MONTH OF DECEMBER.
THE FRONT AND ATTENDANT S/W WILL BRING ANOTHER CHANCE OF RAIN TO
THE AREA MAINLY MONDAY AFTERNOON AND EVENING. AS WITH THE SYSTEM
THAT MOVED THROUGH SATURDAY...THE MID LEVELS WILL BE DRY INITIALLY WITH
VERY LITTLE SATURATION EXPECTED. WITH THE BEST FORCING EXPECTED TO
MOVE THROUGH DURING THE EARLY EVENING HAVE KEPT LOW CHANCE POPS
FOR THE AFTERNOON AND 50 POPS EAST OF THE RIVER MONDAY EVENING.
SOME THUNDER EAST OF THE RIVER CAN/T BE RULED OUT AT THIS TIME BUT
FELT THE POTENTIAL WAS TOO LOW TO INCLUDE IN THE FORECAST FOR NOW.
RAINFALL AMOUNTS MONDAY AND MONDAY NIGHT SHOULD BE
LIGHT...GENERALLY LESS THAN A TENTH OF AN INCH.
QUIET WEATHER SHOULD BE OVER THE AREA TUESDAY AND WEDNESDAY AS
HIGH PRESSURE DOMINATES THE REGION. TEMPERATURES WILL COOL OFF
SOME FOR MID WEEK BUT WILL STILL BE ABOVE NORMAL.
THE NEXT SYSTEM WILL START TO IMPACT THE AREA BY WEDNESDAY NIGHT
AS A S/W CROSSES THE NORTHERN ROCKIES AND PUSHES A COLD FRONT INTO
THE NORTH CENTRAL STATES AND CENTRAL PLAINS BY THURSDAY MORNING.
HAVE GONE WITH SLIGHT CHANCE POPS FOR RAIN NORTHWEST LATE
WEDNESDAY NIGHT THEN CHANCE POPS THURSDAY AND THURSDAY NIGHT AS
THE SYSTEM MOVES THROUGH. THE ECMWF AND GFS ARE IN GOOD AGREEMENT
WITH A BROAD UPPER TROF SETTING UP OVER THE CENTRAL U.S. FOR THE
END OF THE WEEK AND PLACING A BAROCLINIC ZONE OVER THE AREA.
BECAUSE OF THIS SOME LOW POPS WERE HELD ONTO FOR THE SOUTHERN CWFA
INTO FRIDAY NIGHT. TEMPERATURES MAY BE COLD ENOUGH BY FRIDAY NIGHT
TO PRODUCE SOME MIXED PRECIPITATION. THE DEVELOPING UPPER TROF
SHOULD BRING NEAR NORMAL TEMPERATURES TO THE REGION FOR THE END OF
THE WEEK.
DLF
&&
.AVIATION... /ISSUED 1130 PM CST SAT DEC 1 2012/
TREMENDOUSLY MILD AIR HAS MOVED NORTH UP OVER
EASTERN IOWA AND NORTHWEST ILLINOIS. LIFR CONDITIONS AT CID AND
DBQ WILL REMAIN IN PLACE THROUGH MID SUNDAY MORNING. MINIMUMS ARE
LIKELY AT CID AND DBQ...1/4MI VV001...AND REMAIN POSSIBLE AT BRL
AND MLI. AFTER 16Z TO 18Z SUNDAY...ANOTHER WINDOW OF VFR WEATHER
IS LIKELY...AFTER WHICH MORE LOW CLOUDS AND DRIZZLE CAN BE
EXPECTED LATE TOMORROW NIGHT AFTER 06Z/03. WINDS WILL BE LIGHT AND
VARIABLE THROUGH THE PERIOD.
ERVIN
&&
&&
.CLIMATE...
RECORD HIGHS FOR DECEMBER 2...
MOLINE.........65 IN 1982
CEDAR RAPIDS...66 IN 1962
DUBUQUE........62 IN 1982
BURLINGTON.....66 IN 1962
RECORD WARM LOWS FOR DECEMBER 2...
MOLINE.........49 IN 1913
RECORD HIGHS FOR DECEMBER 3...
MOLINE.........69 IN 1970
CEDAR RAPIDS...64 IN 1998
DUBUQUE........64 IN 1970
BURLINGTON.....71 IN 1970
MONTHLY RECORD HIGH...
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...DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR BENTON-
BUCHANAN-DELAWARE-DUBUQUE-IOWA-JEFFERSON-JOHNSON-JONES-
KEOKUK-LINN-WASHINGTON.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
350 PM CST SUN DEC 2 2012
.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...
LOW TO MEDIUM CONFIDENCE FORECAST FOR OVERNIGHT TO EARLY MORNING
HOURS...AS A STRONG SURGE OF MOISTURE WILL AID IN THE FORMATION OF
FOG ACROSS NORTHEAST KANSAS. MODEL GUIDANCE SUGGESTS A PERIOD OF
IFR VIS/CIG AT KTOP...HOWEVER WITH INCREASING WINDS THE LIKELIHOOD
OF DENSE FOG AT KTOP IS RATHER LOW. EVEN IN THE ABSENCE OF DENSE
FOG THERE IS A GOOD CHANCE THAT LOW STRATUS WILL DEVELOP...WHICH
COULD ALSO BRING A PERIOD OF IFR CONDITIONS FOR EARLY MONDAY
MORNING. VFR SHOULD RETURN TO ALL TERMINALS BY MID MORNING MONDAY.
JL
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
1138 PM CST SAT DEC 1 2012
.UPDATE...
FOG CONTINUES TO BE PRESENT ACROSS MUCH OF THE I-135 CORRIDOR AS A
MOIST BOUNDARY LAYER MOVES EASTWARD ACROSS THE AREA. EXPECT
TRANSIENT PATCHY DENSE FOG AT SOME LOCATIONS...BUT STILL NOT
EXPECTING WIDESPREAD DENSE FOG. WILL ALLOW NEXT SHIFT TO MONITOR
FOR TRENDS IF A DENSE FOG ADVISORY IS NEEDED.
BILLINGS
&&
.AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
THE MAIN AVIATION FORECAST CONCERN IS MVFR/IFR AND LIFR CEILINGS
DUE TO PATCHY FOG AND PATCHY DENSE FOG.
MOISTURE CONTINUES TO BE PUSHED OFF EASTWARD AS DRIER AIR MOVES
INTO THE REGION. HOWEVER...WITH THE CLEAR SKIES AND MOISTURE IN
THE AIR EARLIER THIS EVENING SOME LOCATIONS DROPPED TO IFR AND
LIFR CONDITIONS. DO THINK THIS TREND WILL DIMINISH AS THE NIGHT
WARES ON WITH THE DRIER AIR CONTINUING TO PUSH EASTWARD. THINK
THAT MVFR CONDITIONS WILL BE POSSIBLE WITH SOME BRIEF TRANSIENT
PERIODS OF IFR OR LIFR FOR THE NEXT FEW HOURS AT KSLN/KHUT/KICT.
ALSO EXPECTING MVFR TO IFR CONDITIONS TO DEVELOP OVER KCNU CLOSER
TO THE MORNING HOURS WITH THE REMNANT MOISTURE OVER SOUTHEASTERN
KANSAS THIS EVENING. THINGS SHOULD CLEAR OUT OVERNIGHT OUT WEST
WITH VFR CONDITIONS EXPECTED DURING THE DAY SUNDAY. LOOKS LIKE LOW
STRATUS AND FOG COULD DEVELOP AGAIN SUNDAY NIGHT/MONDAY TOWARD THE
END OF THE TAF PERIOD AS WARM MOIST ADVECTION STREAMS NORTHWARD.
BILLINGS
&&
.PREV DISCUSSION... /ISSUED 947 PM CST SAT DEC 1 2012/
UPDATE...
THERE ARE SOME AREAS OF PATCHY FOG WITH SOME LOCATIONS SEEING DENSE
FOG WITH VISIBILITIES OF 1/4 TO 1/2 MILE HOWEVER...FEEL THAT THIS
IS MORE TRANSIENT IN NATURE. WITH THE DRIER AIR MOVING IN AND MID-HIGH
CLOUDS ALSO MOVING IN FROM THE WEST AM NOT ANTICIPATING ISSUING A
DENSE FOG ADVISORY AT THIS TIME.
ALSO DID UPDATE THE CURRENT FORECAST WITH TRENDS OVERNIGHT
REGARDING TEMPS AND DEWPOINTS. NOT ANY BIG WHOLESALE
CHANGES...JUST KEEPING IN LINE WITH TRENDS.
BILLINGS
PREV DISCUSSION... /ISSUED 526 PM CST SAT DEC 1 2012/
AVIATION...00Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
THE MAIN AVIATION CONCERN IS MVFR/IFR CONDITIONS AT KCNU AND
POSSIBLY KRSL/KSLN.
MOISTURE WILL REMAIN PLENTIFUL ACROSS SOUTHEASTERN KANSAS THROUGH
THE EVENING AND EARLY OVERNIGHT HOURS BEFORE THE DRIER AIRMASS
INFILTRATES. AS LONG AS THIS WARM/MOIST AIRMASS REMAINS IN PLACE
THE POSSIBILITY FOR MVFR/IFR CONDITIONS ARE POSSIBLE AT KCNU.
HAVE KEPT THE HINT AT THOSE CONDITIONS IN THE KCNU TAF AND WILL
CONTINUE TO MONITOR FOR UPDATES. AT KRSL/KSLN CLEAR SKIES MAY HELP
TEMPERATURES RADIATE OUT AND SOME BRIEF MVFR VISIBILITIES ARE
POSSIBLE TOWARD MORNING. AGAIN THE NAM/HRRR ARE A LITTLE SLOWER IN
MOVING IN THE DRIER AIR...KEEPING THIS MORE LIKELY. WILL CONTINUE
TO MONITOR THIS EVENING FOR THE QUICKNESS OF THAT DRY AIR TO MOVE
INTO THE AREA.
BILLINGS
PREV DISCUSSION... /ISSUED 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 0
HUTCHINSON 36 72 53 66 / 0 0 0 0
NEWTON 37 72 55 67 / 0 0 0 0
ELDORADO 38 71 55 69 / 0 0 0 0
WINFIELD-KWLD 37 72 57 71 / 0 0 0 0
RUSSELL 32 72 42 64 / 0 0 0 0
GREAT BEND 33 71 44 65 / 0 0 0 0
SALINA 35 73 50 66 / 0 0 0 0
MCPHERSON 36 72 53 66 / 0 0 0 0
COFFEYVILLE 40 71 59 71 / 0 0 0 20
CHANUTE 39 70 56 70 / 0 0 0 10
IOLA 39 70 56 70 / 0 0 0 10
PARSONS-KPPF 39 71 59 71 / 0 0 0 20
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1118 PM CST SAT DEC 1 2012
...UPDATED SYNOPSIS AND AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 1114 PM CST SAT DEC 1 2012
AT 00Z SUNDAY A 500MB LOW WAS LOCATED JUST OFF THE BRITISH
COLUMBIA COAST. AN UPPER LEVEL TROUGH WAS LOCATED NEAR THE BASED
OF THIS UPPER LEVEL LOW JUST OFF THE COAST OF THE PACIFIC
NORTHWEST. FURTHER EAST A WEAKER UPPER WAVE APPEARS TO BE NEAR
WESTERN MONTANA. THIS WEAKER UPPER LEVEL SYSTEM WAS RELATED TO A
100KT 250MB JET. AT THE 700MB LEVEL, A RIDGE AXIS WAS LOCATED
ALONG THE SPINE OF THE ROCKIES WITH TEMPERATURES RANGING FROM 0C
TO +5C ACROSS WESTERN KANSAS AND EASTERN COLORADO. 850MB
TEMPERATURES AT 00Z SUNDAY RANGED FROM +15C AT NORTH PLATTE AND
DODGE CITY TO +18C AT AMARILLO. AT THE SURFACE A RIDGE OF HIGH
PRESSURE WAS LOCATED ACROSS SOUTHWEST KANSAS.
&&
.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 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1114 PM CST SAT DEC 1 2012
WEAK WESTERLY FLOW ACROSS WESTERN KANSAS IS EXPECTED TO CONTINUE
OVERNIGHT AS THE SURFACE RIDGE AXIS SLIDES SLOWLY EAST OF THE
AREA. BASED ON THE WESTERLY WINDS AND DRIER AIR FILTERING INTO
WESTERN KANSAS EXPECTED VFR CONDITIONS TO PREVAIL OVERNIGHT. MAY
BE A BRIEF PERIOD OF MVFR VSBYS AT ALL TAF SITES AROUND DAYBREAK
BUT THIS WILL BE BRIEF SO WILL NOT INCLUDE IN THE 06Z TAFS.
SURFACE TROUGH OF LOW PRESSURE WILL DEVELOP ACROSS EASTERN
COLORADO DURING THE DAY ON SUNDAY. SOUTHEAST WINDS WILL DEVELOP
AND INCREASE TO AROUND 15KTS DURING THE DAY AS PRESSURES FALL
ALONG THE LEE OF THE ROCKIES.
&&
.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...BURGERT
SHORT TERM...SUGDEN
LONG TERM...KRUSE
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS CARIBOU ME
118 AM EST SUN DEC 2 2012
.SYNOPSIS...
A WARM FRONT WILL APPROACH FROM THE SOUTHWEST TONIGHT AND LIFT
NORTH THROUGH REGION ON SUNDAY WHILE LOW PRESSURE TRACKS NORTH
OF THE STATE. A WEAK COLD FRONT WILL CROSS THE AREA FROM QUEBEC
SUNDAY NIGHT FOLLOWED BY HIGH PRESSURE ON MONDAY.
&&
.NEAR TERM /THROUGH TODAY/...
1240 AM UPDATE: THE ONLY SIG CHGS WERE TO EXTND THE WNTR WX ADVS
FOR THE DOWNEAST AND CNTRL ZONE GROUPS ONE HR EACH TO GIVE A
LITTLE ORE MARGIN IN CASE LOW LVL DAMMING HOLD ON A LITTLE LONGER
IN THESE AREAS. OTHERWISE...LOADED LATEST MDNGT OBSVD SFC TEMPS
AND MERGED TO 7 AM TEMPS...WHICH IMPLIES SLOWLY RISING TEMPS
ACROSS THE FA FOR THE REST OF THE OVRNGT.
945 PM UPDATE: ADDED THE COAST INTO THE WINTER WEATHER ADVISORY
WITH SNOW AND FZRA. RECEIVED REPORTS OF SOME LIGHT ACCUMULATION ON
THE HANCOCK COUNTY COAST. EXPECTING SNOW TO CHANGE OVER TO FZRA
BEFORE GOING TO RAIN LATER TONIGHT AS SOUTH WINDS WILL PUSH THE
WARMER AIR IN OFF THE GULF OF MAINE. TEMPERATURES WERE ADJUSTED TO
MATCH THE LATEST CONDITIONS. LAPS/RUC SOUNDINGS SHOWING THAT WARM
NOSE SETTING UP ACROSS SRN MAINE W/SNOW GOING OVER TO FZRA SUCH AS
IZG(FRYEBURG). THIS WARM NOSE WILL PROCEED NORTHWARD OVERNIGHT
SETTING THE STAGE FOR SOME MIXED/FREEZING PRECIP IN OUR CWA BY
SUNDAY MORNING. A BRIEF BURST OF SNOW IS POSSIBLE W/THE 40KT LLVL
JET FCST TO MOVE IN OVERNIGHT BY THE LATEST RUC AND NAM12 WHICH
ARE HANDLING THIS QUITE WELL PER THE 00Z OBS AND RADAR TRENDS.
ORGNL DISC: SNOW IS EXPECTED TO SPREAD FROM SOUTH TO NORTH OVER THE
AREA LATER IN THE EVENING. WARMER AIR MOVING IN FROM THE SOUTH
WILL THEN CHANGE THE SNOW OVER TO RAIN...FIRST ALONG THE COAST
LATER THIS EVENING...OVER CENTRAL AREAS EARLY TOMORROW MORNING AND
IN THE FAR NORTH LATER TOMORROW MORNING. GROUND AND ROAD SURFACES
WILL LIKELY BE BELOW FREEZING AS THE CHANGEOVER OCCURS SO A BAND
OF FREEZING RAIN HAS BEEN INCLUDING ALONG THE LINE OF CHANGEOVER
AND WINTER WEATHER ADVISORIES HAVE BEEN ISSUED FOR FREEZING
RAIN...INITIALLY DOWNEAST BEGINNING THIS EVENING THEN OVER THE
NORTH EARLY SUNDAY MORNING. BY MIDDAY SUNDAY TEMPS SHOULD HAVE
RISEN ABOVE FREEZING THROUGHOUT THE AREA AS SOUTH WINDS PULL
WARMER AIR ACROSS THE STATE. LOW CLOUDS...PATCHY DRIZZLE...FOG AND
SOME SHOWERS WILL BE LIKELY WITH MOST OF THE SHOWERS IN THE HIGHER
ELEVATIONS OF WESTERN AND NORTHERN AREAS.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY/...
A WEAK COLD FRONT WILL MOVE FROM QUEBEC INTO THE CROWN OF MAINE
SUNDAY EVENING AND SINK SOUTHWARD OVERNIGHT. THE TYPE OF PRECIPITATION
WITH THIS FEATURE WILL BE ALL RAIN EVERYWHERE. LOWS WILL ONLY DIP
TO THE UPPER 30S TO LOW 40S BY DAYBREAK. WITH SOME PRETTY GOOD
LIFT...THE RAINFALL COULD AMOUNT TO UP TO A HALF INCH IN NORTHERN
ZONES AND LESSER AMOUNTS DOWN EAST. PRECIPITATION MOVES OUT OF
EASTERN MAINE EARLY MONDAY. TRANSITORY HIGH PRESSURE BUILDS DURING
MONDAY WITH A NORTHWEST FLOW BUT WEAK COLD AIR ADVECTION. AS A
RESULT...HIGHS WILL CLIMB TO THE LOW TO MID 40S IN NORTHERN ZONES
AND UPPER 40S TO AROUND 50F DOWN EAST. SOME H925-H850 MOISTURE
REMAINS BUT EXPECT SOME AFTERNOON SUNSHINE.
HIGH PRESSURE CRESTS OVER THE AREA MONDAY NIGHT. WITH CLEAR SKIES
AND CALM WINDS TEMPERATURES WILL DIP INTO THE MID 20S NORTH TO THE
LOW TO MID 30S SOUTH. UNDER A RADIATION INVERSION...SOME FREEZING
FOG COULD FORM WITH AREAS OF BLACK ICE. AS SOUTH WINDS BEGIN TO
INCREASE TOWARDS TUESDAY MORNING FOG IS LIKELY TO LIFT TO LOW
STRATUS. AREAS OF FOG AND LOW STRATUS MAY PERSIST INTO THE MORNING
WITH MID AND HIGH LEVEL CLOUDS MOVING IN DURING THE AFTERNOON AHEAD
OF THE NEXT COLD FRONT. THIS FEATURE WILL BRING A CHANCE OF RAIN
BY LATE IN THE DAY HOWEVER MOST OF THE PRECIPITATION SHOULD HOLD
OFF UNTIL TUESDAY NIGHT.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
A COLD FRONT WILL BEGIN TO CROSS THE REGION TUESDAY NIGHT WITH
RAIN SHOWERS. ACROSS NORTHWEST PORTIONS OF THE FORECAST AREA...JUST
ENOUGH COLD AIR BEHIND THE FRONT COULD ALLOW THE RAIN SHOWERS TO
MIX WITH SNOW SHOWERS LATE. THE COLD FRONT WILL CROSS THE REGION
WEDNESDAY WITH RAIN SHOWERS IN ADVANCE OF THE FRONT AND RAIN/SNOW
SHOWERS IN THE WAKE OF THE FRONT. THE FRONT WILL MOVE EAST OF THE
REGION WEDNESDAY NIGHT...WITH UNCERTAINTY REGARDING LOW PRESSURE
WHICH COULD POSSIBLY BEGIN TO DEVELOP ALONG THE FRONT OVER THE
MARITIMES. IF THE LOW DOES NOT DEVELOP...THE FRONT WILL BE MORE
PROGRESSIVE ALLOWING SNOW SHOWERS TO DECREASE ACROSS THE REGION
WEDNESDAY NIGHT. IF LOW PRESSURE DOES BEGIN TO DEVELOP ALONG THE
FRONT...THE FRONT COULD SLOW WITH THE LOW POSSIBLY WRAPPING
PRECIPITATION BACK TOWARD EASTERN PORTIONS OF THE FORECAST AREA
WHICH COULD ALLOW PRECIPITATION TO LINGER ACROSS EASTERN AREAS.
HIGH PRESSURE WILL CROSS THE REGION THURSDAY. ANOTHER COLD FRONT
WILL APPROACH FRIDAY...THEN CROSS THE REGION FRIDAY NIGHT INTO
SATURDAY WITH SNOW SHOWERS ACROSS NORTHERN AREAS AND RAIN/SNOW
SHOWERS DOWNEAST. LOW PRESSURE COULD POSSIBLY DEVELOP ALONG THE
FRONT ACROSS THE GULF OF MAINE SATURDAY...WHICH COULD ALLOW FOR
STEADIER PRECIPITATION DOWNEAST. TEMPERATURES SHOULD BE AT
SLIGHTLY ABOVE NORMAL LEVELS WEDNESDAY/FRIDAY...WITH NEAR NORMAL
LEVEL TEMPERATURES THURSDAY/SATURDAY.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
NEAR TERM: CONDITIONS WILL LOWER TO IFR FROM SOUTH TO NORTH
OVERNIGHT THEN REMAIN IFR IN LOW CLOUDS ON SUNDAY. SOME LIGHT
FREEZING RAIN IS EXPECTED DOWNEAST THIS EVENING AND OVER THE NORTH
SUNDAY MORNING.
SHORT TERM: CONDITIONS WILL BE IFR SUNDAY NIGHT IN RAIN AND LOW
CLOUDS BEFORE IMPROVING TO VFR MONDAY. MORE IFR IS LIKELY MONDAY
NIGHT INTO TUESDAY MORNING IN FOG AND STRATUS. THESE CONDITIONS
MAY BRIEFLY IMPROVE DURING THE DAY TUESDAY BEFORE THE NEXT SYSTEM
ARRIVES AT NIGHT. MVFR/IFR CONDITIONS ARE EXPECTED TUESDAY NIGHT
INTO WEDNESDAY. VFR CONDITIONS ARE EXPECTED THURSDAY.
&&
.MARINE...
NEAR TERM: AN SCA HAS BEEN ISSUED FOR SOUTH WINDS INCREASING THIS
EVENING AND CONTINUING THROUGH SUNDAY. SEAS WILL BUILD UP TO 8 FT
IN RESPONSE TO THE SOUTH WINDS AND SOME FOG MAY LIMIT VISIBILITIES
OVER THE WATERS.
SHORT TERM: WINDS AND SEAS ARE EXPECTED TO REMAIN AT SCA LEVELS
UNTIL EARLY MONDAY MORNING. AFTER A BRIEF RESPITE WINDS WINDS AND
SEAS WILL INCREASE AGAIN LATE TUESDAY AHEAD OF THE NEXT SYSTEM.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
MEZ001-002.
WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
MEZ003>006-010-011-031-032.
WINTER WEATHER ADVISORY UNTIL 7 AM EST THIS MORNING FOR
MEZ015>017-029-030.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST MONDAY FOR ANZ050>052.
&&
$$
NEAR TERM...VJN
SHORT TERM...FITZSIMMONS
LONG TERM...NORCROSS
AVIATION...VJN
MARINE...VJN/FITZSIMMONS
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
308 PM EST SUN DEC 2 2012
.SYNOPSIS...
A WEAK FRONT WILL DISSIPATE SOUTH OF THE MASON DIXON LINE TONIGHT.
HIGH PRESSURE BRIEFLY BUILDS IN MONDAY...BEFORE MOVING OFF THE COAST
TUESDAY AS THE NEXT COLD FRONT APPROACHES. THE NEXT FRONTAL PASSAGE
EXPECTED TUESDAY NIGHT INTO EARLY WEDNESDAY. HIGH PRESSURE RETURNS
FOR THE LATER PORTION OF THE WEEK.
&&
.NEAR TERM /THROUGH MONDAY/...
AN UPPER SHORTWAVE TROUGH AND SFC LOW CURRENTLY NORTH OF THE GREAT
LAKES WILL TRACK EWD INTO NRN NEW ENGLAND TNGT. ATTENDANT COLD FRONT
STRETCHES SEWD INTO THE UPPER MIDWEST. SWLY LOW- AND MID-LVL JET IN
PRE-FRONTAL WARM SECTOR HAS DRAWN A NARROW PLUME OF MOISTURE
/WHERE PWATS ARE AOB 1 INCH/ STREAMING UP THE WRN SIDE OF THE
APPALACHIANS. A BAND OF SHOWERS WITHIN THIS PLUME/LLVL JET IS
CURRENTLY CROSSING THE ALLEGHENY FRONT.
THE SRN PORTION OF THE FRONT WILL DISSIPATE TNGT AS IT PROGRESSES
EWD TOWARD THE MID-ATLANTIC REGION AND BECOMES EMBEDDED IN
INCREASINGLY ZONAL FLOW. THEREFORE...THE BAND OF SHOWERS SHOULD
WEAKEN AND ACQUIRE A MORE ZONAL TILT AS IT CROSSES THE MTS.
MEASURABLE PRECIP THRU THIS EVE WILL BE LIKELY OVER THE MTS AND IN
NORTH-CENTRAL MD. POPS DECREASE TO CHANCE CAT FARTHER SOUTH AND
EAST. LATEST HRRR SHOWS THE BULK OF THE PRECIP CLEARING THE REGION
BEFORE MIDNIGHT...ALTHOUGH SCT SHOWERS MAY LINGER INTO THE OVNGT
ALONG THE WRN SLOPES OF THE ALLEGHENY FRONT. QPF AMOUNTS GENERALLY
UNDER ONE-TENTH INCH EXCEPT IN THE WRN HIGHLANDS.
NW FLOW ALOFT WILL FILTER IN MID-LVL DRY AIR. NOT SURE HOW MUCH
DRYING WILL OCCUR IN THE BOUNDARY LAYER...BUT THE HIGHEST
PROBABILITY FOR CLEARING OVNGT WILL BE ACROSS NRN MD. IF CLEARING
DOES OCCUR...DEVELOPMENT OF FOG AND STRATUS WILL BECOME FAVORABLE.
THIS CONDITIONAL SETUP NOT AS FAVORABLE FOR FOG THAT IS AS
WIDESPREAD/DENSE AS THIS MRNG. MIN TEMPS GENERALLY IN THE 40S...
ALTHOUGH TEMPS MAY BOTTOM OUT A FEW DEGREES MORE THAN ADVERTISED
IF CLEARING OCCURS EARLIER.
HIPRES/UPPER RIDGE BUILDS INTO THE AREA MON. MOISTURE HUNG UP ALONG
THE OLD FRONTAL BOUNDARY MAY KEEP CLOUDS IN THE AREA ESPECIALLY OVER
THE MTS /EVEN AFTER ANY MRNG STRATUS MIXES OUT/. DESPITE THE CLOUD
COVER...MAX TEMPS IN THE 60S CAN BE EXPECTED. HIGHS APPROACH 70F IN
CENTRAL VA.
&&
.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
HIGH PRESSURE MOVES OFFSHORE MONDAY NIGHT AS A COLD FRONT MOVES INTO
THE OHIO VALLEY. THE FRONT WILL MOVE THROUGH MOST OF THE CWFA
BY TUESDAY NIGHT.
POPS REMAIN HIGHEST ALONG AND WEST OF THE BLUE RIDGE AND ALONG THE
MASON DIXON LINE TUESDAY NIGHT. THIS IS CONSISTENT WITH PREVIOUS
MODEL RUNS. HOWEVER...POPS HAVE CONTINUED TO INCREASE OVER THE SE
CWFA FROM RUN TO RUN...BUT PROBABILITIES STILL REMAIN IN THE LOW
CHANCE CATEGORY.
TEMPERATURES ARE EXPECTED TO BE NEAR 20 DEGREES ABOVE NORMAL DURING
THE DAY ON TUESDAY. MIN TEMPS TUESDAY NIGHT SHOULD REMAIN IN THE 40S
TO LOWER 50S IN MOST LOCALES...SOME 10-12 DEGREES ABOVE NORMAL.
PTYPE IS NOT EXPECTED TO BE AN ISSUE...WITH ALL RAIN FORECAST.
&&
.LONG TERM (WEDNESDAY THROUGH SUNDAY)...
COLD FRONT STILL ACROSS LOWER SOUTHERN MARYLAND EARLY WEDNESDAY
MORNING...BUT SHOULD MOVE SOUTH OF THE AREA BY MIDDAY. SHOWERS WILL
DECREASE ACROSS THIS AREA THROUGH LATE MORNING.
HIGH PRESSURE WILL BRIEFLY BUILD IN FOR THURSDAY...BUT MOVE OFFSHORE
ON FRIDAY WITH RETURN FLOW SETTING UP. POPS BEGIN TO INCREASE FRIDAY
NIGHT AS AN UPPER DISTURBANCE MOVES ACROSS THE REGION. IN
ADDITION...ISENTROPIC LIFT SHOULD ALSO BEGIN TO INCREASE ACROSS THE
MID ATLANTIC AS A WARM FRONT BEGINS TO PUSH NORTHWARD SATURDAY.
MODELS HAVE SLOWED DOWN THE APPROACH OF THE COLD FRONT TO SUNDAY.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
MID-LVL CLOUDS WILL THICKEN FROM WEST TO EAST LATE THIS AFTN AS A
FRONTAL BOUNDARY APPROACHES FROM THE WEST. A FEW SHOWERS POSSIBLE
LATE THIS AFTN AT MRB AND ERY TO MID EVE AT THE OTHER TERMINALS.
MAINLY VFR CIGS/VSBYS EXPECTED THIS EVE. CONCERN WILL BE IF/WHEN
CLOUDS CLEAR OUT. IF THEY OCCUR EARLY ENOUGH /I.E. OVNGT/ THEN LOW
CLOUDS AND FOG COULD DEVELOP. ALL TERMINALS FCST TO SEE AT LEAST
MVFR REDUCTION TOWARD MRNG. THE NRN TERMINALS WILL HAVE THE BEST
CHANCE TO EXPERIENCE CLEARING AND THUS IFR CIGS/VSBYS.
A COLD FRONT WILL MOVE THROUGH THE MIDDLE ATLANTIC TUESDAY NIGHT
INTO EARLY WEDNESDAY. SUB VFR CONDITIONS EXPECTED WITH SCT/NMRS
SHOWERS AND POSSIBLY SOME FOG.
HIGH PRESSURE BUILDS IN FOR THURSDAY...BUT MOVES OFFSHORE ON FRIDAY.
&&
.MARINE...
SLY FLOW 10-15 KT THRU THE EVE. DESPITE 20-25 KT WINDS JUST ABOVE
THE SFC...COOL WATER TEMPS SHOULD PREVENT THESE STRONGER WINDS FROM
REACHING THE SFC. WILL NEED TO WATCH FOR SLY CHANNELING THRU THE
EVE...WHICH COULD LOCALLY/BRIEFLY ENHANCE WINDS TO NEAR SCA LVLS.
WINDS SHIFT OUT OF THE NW OVNGT AND MON ONCE A FRONTAL BOUNDARY
PASSES THRU. LGT WINDS EXPECTED WITH THE NW FLOW.
A COLD FRONT WILL CROSS THE WATERS LATE TUESDAY INTO EARLY
WEDNESDAY...ACCOMPANIED BY SCT/NMRS SHOWERS. HIGH PRESSURE BUILDS IN
FOR THURSDAY...BUT MOVES OFFSHORE FRIDAY SETTING UP RETURN FLOW. THE
NEXT FRONT LOOKS TO IMPACT THE WATERS BY LATE NEXT WEEKEND.
SMALL CRAFT CONDITIONS ARE POSSIBLE WEDNESDAY AFTERNOON AND NIGHT
BEHIND THE COLD FRONT AS NORTHERLY FLOW CHANNELS DOWN THE BAY.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
&&
$$
KLEIN/LISTEMAA
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
238 AM EST SUN DEC 2 2012
.SYNOPSIS...
HIGH PRESSURE WILL MOVE OFF THE EASTERN SEABOARD OVERNIGHT. A WEAK
COLD FRONT WILL MOVE ACROSS THE REGION LATE SUNDAY INTO EARLY
MONDAY. HIGH PRESSURE WILL BUILD ACROSS THE AREA LATE MONDAY INTO
EARLY TUESDAY...WITH THE NEXT FRONTAL BOUNDARY EXPECTED LATE TUESDAY
INTO EARLY WEDNESDAY. HIGH PRESSURE RETURNS FOR THURSDAY AND FRIDAY.
&&
.NEAR TERM /THROUGH TODAY/...
THICKEST FOG DVLPD OUTSIDE ADVY AREA...INVOF HGR/MRB. HV ADDED
THAT AREA TO DENSE FOG ADVY...AND EXPANDED EVERYTHING TIL 9AM
CONSIDERING SUN ANGLE.
PRVS DSCN FOLLOWS. FULL DSCN SHORTLY. -HTS
MAIN CONCERN IS WITH DENSE FOG POTENTIAL FOR THE OVERNIGHT PERIOD.
LATEST 01Z LAMP GUIDANCE SUGGESTS SOME POCKETS OF HALF MILE FOG
MAINLY ALONG THE WESTERN SHORE OF THE BAY AND A FEW AREAS EAST OF
THE BLUE RIDGE. LATEST 01/23Z HRRR 3KM MODEL GUIDANCE IS MORE
PESSIMISTIC AND HAS 1/4 MILE VSBYS PRETTY MUCH EVERYWHERE EAST OF
THE BLUE RIDGE. LATEST OBS MAINLY IN 3-5SM RANGE...WITH A COUPLE
OF SFC SITES IN SOUTHERN ST. MARYS COUNTY DOWN TO 1/4 MILE.
WEAK EASTERLY FLOW AT THE SURFACE STILL EVIDENT ACROSS THE REGION
AS THE WEAK...DIFFUSE FRONT IS STILL ALONG THE APPLACHAINS. ONE
FACTOR GOING AGAINST DENSE FOG IS SOME HIGH CLOUDS EXPECTED TO
STREAM IN LATE TONIGHT. BUT THINK THEY WILL BE TOO LATE TO HALT
FOG PRODUCTION.
GIVEN ABUNDANT LOW LEVEL MOISTURE...AND GUIDANCE SHOWING 1/4 MILE
FOG A LIKELY BET...WILL ISSUE A DENSE FOG ADVISORY FOR TONIGHT
FOR AREAS ALONG AND EAST OF THE BLUE RIDGE TO THE CHESAPEAKE BAY.
ON SUN...AFTER A PERIOD OF EARLY MORNING FOG...EXPECT SOUTHERLY
WINDS TO SCOUR OUT REMAINING FOG BY LATE MORNING. 850 HPA TEMPS
EXPECTED TO BE IN THE RANGE OF 3-5 DEGC WARMER THAN TODAY. GIVEN
DECENT AFTERNOON MIXING...EXPECT WARMER TEMPS FOR SUN THAN WHAT
WAS EXPECTED TODAY. HOWEVER...SHOULD SOME AREAS REMAIN FOG
SHROUDED LONGER...TEMPS WILL CERTAINLY BE A BIT COOLER THAN WHAT
IS ADVERTIZED...MAX TEMPS RANGING FROM THE LOW/MID 50S NORTH-
CENTRAL MD TO MID 60S IN CENTRAL VA.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
A WEAK COLD FRONT WILL APPROACH THE MASON DIXON LINE BY 00Z MONDAY
AND DISSIPATE AS IT PUSHES SOUTH OVER THE CWFA. MODELS DO AGREE THE
BEST CHANCES OF PRECIP WILL BE IN THE HIGHLANDS AND ALONG THE MASON
DIXON LINE. HAVE ADJUSTED POPS AND TIMING DURING THIS PERIOD. TEMPS
LOOK WARM ENOUGH THAT THERE SHOULDN`T BE ANY PTYPE ISSUES.
POPS LOOK LOW ACROSS THE FAR SE CWFA AT THIS TIME...SO WILL LEAVE
OUT ANY MENTION OF PRECIP AT THIS TIME.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
HIGH PRESSURE WILL REMAIN OFF THE SE COAST ON TUESDAY AS A COLD
FRONT APPROACHES FROM THE OHIO VALLEY. THE FRONT SHOULD PUSH THROUGH
THE CWFA LATE TUESDAY INTO EARLY WEDNESDAY...ACCOMPANIED BY
SCATTERED SHOWERS. TEMPERATURES WILL RANGE 10 TO 15 DEGREES ABOVE
NORMAL TUESDAY AND TUESDAY NIGHT. TEMPS WILL BE WARM ENOUGH FOR ALL
RAIN...EVEN AT THE HIGHER ELEVATIONS.
HIGH PRESSURE RETURNS FOR THURSDAY...BUT SHOULD MOVE OFFSHORE ON
FRIDAY AHEAD OF THE NEXT FRONTAL SYSTEM. THE FRONT IS EXPECTED TO
IMPACT THE AREA DURING THE WEEKEND.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
PD OF LIFR XPCTD THRU SUNRISE FOR IAD/DCA/BWI. DENSEST FOG THUS
FAR ACTUALLY AT MRB. WL AMD THAT TAF SHORTLY. EXPECT CONDITIONS
IMPRVG BY 13-14Z ABOVE IFR TO VFR BY 15Z.
MVFR CONDITIONS POSSIBLE LATE SUNDAY NIGHT/EARLY MONDAY AS A WEAK
COLD FRONT APPROACHES THE MASON DIXON LINE. THE NORTHERN TERMINAL
SITES WILL BE THE MOST LIKELY TO HAVE CIGS/VSBYS REDUCED IN SCT
SHOWERS.
A SECOND COLD FRONT IS EXPECTED TUESDAY NIGHT INTO WEDNESDAY...
BRINGING ANOTHER ROUND OF SCT SHOWERS.
&&
.MARINE...
LIGHT EASTERLY FLOW OR CALM CONDITIONS OVER THE WATERS TONIGHT.
SOME AREAS OF FOG BELOW 1 NM EXPECTED.
ON SUNDAY...SOUTHERLY FLOW WILL SET UP...BUT WINDS EXPECTED TO BE
LESS THAN 10 KTS MARINE WIDE.
A WEAK COLD FRONT WILL APPROACH THE MASON DIXON LINE LATE SUNDAY
NIGHT INTO EARLY MONDAY AND DISSIPATE AS IT PUSHES SOUTH ACROSS THE
NORTHERN WATERS. A SECOND COLD FRONT IS EXPECTED TO IMPACT THE
REGION TUESDAY NIGHT INTO EARLY WEDNESDAY. HIGH PRESSURE RETURNS FOR
THURSDAY.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR DCZ001.
MD...DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR MDZ003>007-
009>011-013-014-016>018.
VA...DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR VAZ040-042-
051>055-501-502.
WV...DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR WVZ051>053.
MARINE...NONE.
&&
$$
SYNOPSIS...SMZ
NEAR TERM...HTS/SMZ
SHORT TERM...NWL
LONG TERM...NWL
AVIATION...HTS/SMZ
MARINE...SMZ
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
642 PM EST MON DEC 3 2012
.SYNOPSIS...
ISSUED AT 330 PM EST MON DEC 3 2012
AN APPROACHING COLD FRONT WILL INTERACT WITH AN UNSEASONABLY WARM
AND MOIST AIR MASS TO PRODUCE RAIN SHOWERS AND A FEW THUNDERSTORMS
TONIGHT. DECREASING CLOUDS WILL FOLLOW ON TUESDAY BEHIND THE
DEPARTING FRONT... AND HIGH PRESSURE WILL SETTLE OVER THE REGION ON
WEDNESDAY. ALTHOUGH IT WILL COOL DOWN BEHIND THE COLD FRONT...
TEMPERATURES WILL REMAIN ABOVE NORMAL THROUGH THE REST OF THE WEEK.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 330 PM EST MON DEC 3 2012
UNSEASONABLY WARM/MOIST AIR MASS CONTINUES SURGING NORTH THIS
AFTERNOON... WITH READINGS NOW IN THE 60S OVER IN SW LWR MI AND DEW
POINTS AROUND 60. SOME INSTABILITY IS SHOWING UP AS WELL... WITH MU
CAPES OF 500 TO 1000 J/KG NOW OVER WI/IL AND LK MI.
THE PRIMARY THREAT OF SHOWERS AND A FEW TSTMS WILL COME LATER THIS
EVENING WITH THE COLD FRONT... BUT CAN/T RULE OUT A FEW ISOLATED
CELLS DEVELOPING BETWEEN NOW AND THEN WITHIN THE STRONG WARM
ADVECTION CORRIDOR NOW NUDGING INTO THE REGION FROM THE SOUTHWEST.
THE LOW LEVEL JET AHEAD OF THE FRONT IS PROGGED TO INCREASE TO 50 TO
55 KTS BY 03Z... WHICH MAY SUPPORT SOME HEALTHY WIND GUSTS FROM ANY
DEEPER CONVECTION WHICH DEVELOPS OR MOVES INTO THE REGION FROM THE
WEST THIS EVENING.
THE BULK OF THE RAIN WITH THE FRONT SHOULD BE OVER BY 12Z TUESDAY
WITH THE EXCEPTION OF THE SE CWFA WHERE MORNING SHOWERS ARE STILL
LIKELY AROUND JACKSON. OTHERWISE EXPECT DECREASING CLOUDS FROM WEST
TO EAST AS STRONG DRYING/SUBSIDENCE SWEEPS IN BEHIND THE FRONT.
BRIEF SHOT OF NW FLOW COLD ADVECTION MAY PRODUCE A FEW LAKE EFFECT
FLURRIES TUESDAY NIGHT BEFORE THE SFC HIGH BUILDS IN FOR WEDNESDAY.
WARM ADVECTION COMMENCES ALREADY AGAIN ON WEDNESDAY NIGHT AS THE
HIGH SLIPS AWAY.
.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 330 PM EST MON DEC 3 2012
DRY WX WITH SEASONABLY MILD TEMPS IS ANTICIPATED THURSDAY MORNING
AND AFTERNOON BEFORE THE APPROACHING COLD FRONT BRINGS A CHC OF
MIXED LIGHT RAIN AND LIGHT SNOW SHOWERS LATE THURSDAY NIGHT INTO
FRIDAY.
A FEW LIGHT SNOW SHOWERS/FLURRIES ARE POSSIBLE SATURDAY TO THE NORTH
OF THE WARM FRONT OVER THE LOWER GREAT LAKES REGION. THE WARM FRONT
SHOULD MAKE A PUSH NORTHWARD IN ADVANCE OF A DEVELOPING LOW PRESSURE
SYSTEM SATURDAY NIGHT AND SUNDAY WHICH WILL BRING RAIN SHOWERS FOR
SUNDAY. CANNOT RULE OUT SOME WET SNOW FLAKES MAINLY NORTH OF I-96
SUNDAY BUT OVERALL MEDIUM RANGE GUIDANCE HAS TRENDED A LITTLE MILDER
FOR SUNDAY.
TEMPS WILL CONTINUE TO AVERAGE ABOVE NORMAL FRIDAY THROUGH THE
WEEKEND BEFORE RETURNING TO NEAR NORMAL BEHIND THAT SYSTEM FOR EARLY
NEXT WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 642 PM EST MON DEC 3 2012
THE IFR CIGS/VSBY WILL BRIEFLY BREAK OUT THIS EVENING AS MIXING
AHEAD OF THE COLD FRONT PUSHES THE LOW CLOUDS AND FOG NORTHWARD
OUT OF THE AREA BEFORE THE RAIN WITH THE FRONT MOVES IN. THIS IS
SHOWN BY BOTH THE NAM AND RAP MODELS. SURFACE OBS SHOW THIS TREND
TOO AS SBN...LWA...BIVA AND NOW MKG HAVE LOST ALL LOW CLOUDS AND
VSBY ARE 10SM.
THE FRONTAL RAIN BAND WILL CONTINUE TO DEVELOP OVER TIME THIS
EVENING AS THE FRONT PUSHES TOWARD SOUTHWEST LOWER MICHIGAN. MODEL
SOUNDING SHOW A SIGNIFICANT LACK OF MID LEVEL MOISTURE (ABOVE 10000
FT AGL) AS THE RAIN BAND MOVES THROUGH THE AREA. HOWEVER LATER
THIS EVENING AS THE JET ENTRANCE REGION GETS CLOSER TO THE FRONT
THE LIFT IMPROVES AND SO THEN DOES THE DEEP MOISTURE. HOWEVER BY
THEN THE RAIN BAND SHOULD FOR THE MOST PART BE THROUGH THE TAF
SITES. THIS MEANS TO ME THE RAIN SHOULD NOT BE ALL THAT HEAVY SO
I DID NOT LOWER THE VSBY BELOW 3 MILES WITH THE SHOWERS.
ISOLATED THUNDERSTORMS ARE POSSIBLE AS THERE IS SOME MARGINALLY
POSITIVE CAPE BUT IT IS VERY NARROW AND IN THE AREA WITH DRY MID
LEVEL AIR. ALSO ONCE AGAIN THE BETTER JET DYNAMICS TO NOT GET HERE
UNTIL THE CONVECTIVE LINE IS EAST OF HERE. EVEN SO THERE IS 40 TO
50 KNOTS IN THE BOUNDARY LAYER THIS EVENING SO ANY SHOW COULD
BRING DOWN GUSTY WINDS BUT THE SOUNDINGS SHOW THE LOW LEVELS WILL
BE MOIST. THAT TYPICALLY IS NOT CONDUCIVE TO BRINGING DOWN THE
STRONGER WINDS IN THE 1000 TO 5000 FT LAYER. SO I HAVE VCTS IN
TAFS AS THE DID THE PREVIOUS FORECAST... IT STORMS DO IN FACT
DEVELOP I WILL UPDATE THE TAFS TO INCLUDE THEM.
SHOULD BE BRIEF PERIOD OF LOW CLOUDS WITH THE COLD FRONT (AGAIN
BASED NO MODEL SOUNDING) BUT THIS TIME THEY SHOULD QUICKLY CLEAR
AFTER THE FRONT COMES THROUGH SO I HAVE ONLY MID CLOUDS AFTER 12Z
AT THE TAF SITES.
&&
.MARINE...
ISSUED AT 330 PM EST MON DEC 3 2012
AREAS OF DENSE FOG WERE STILL IMPACTING THE LK MI NEARSHORE PER THE
WEB CAM ON THE MUSKEGON PIER. HOWEVER VISIBILITIES WERE DECENT AT
OTHER MARINE SITES. THE FOG SHOULD BECOME LESS OF AN ISSUE AS THE
EVENING PROGRESSES.
A SMALL CRAFT ADVISORY IS CURRENTLY IN EFFECT DUE TO THE STRONG
SOUTH FLOW AHEAD OF THE FRONT. WHILE THERE MAY BE A BRIEF LULL
TUESDAY MORNING ALONG AND JUST BEHIND THE FRONT... WEST NORTHWEST
FLOW IS EXPECTED TO PICK UP AGAIN LATER TUESDAY INTO TUESDAY NIGHT.
HAVE THEREFORE EXTENDED THE SMALL CRAFT ADVISORY THROUGH WEDNESDAY
MORNING.
&&
.HYDROLOGY...
ISSUED AT 330 PM EST MON DEC 3 2012
ALTHOUGH SOME LOCALIZED RAIN AMOUNTS IN EXCESS OF 0.50 ARE POSSIBLE
TONIGHT... BASIN AVERAGE RAINFALL IS EXPECTED TO BE AROUND 0.25
INCH. THIS WILL HAVE LITTLE TO NO IMPACT ON THE RIVERS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 11 AM EST WEDNESDAY FOR LMZ844>849.
&&
$$
SYNOPSIS...MEADE
SHORT TERM...MEADE
LONG TERM...LAURENS
AVIATION...WDM
HYDROLOGY...MEADE
MARINE...MEADE
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
417 AM CST SUN DEC 2 2012
.DISCUSSION...
RESTRICTED VISIBILITY FROM THE FOG/FREEZING FOG WILL GRADUALLY
IMPROVE THIS MORNING...WITH TEMPERATURES RISING ABOVE FREEZING BY
THE NOON HOUR ACROSS THE ENTIRE CWA. SOUTHERLY WINDS WILL INCREASE
TODAY WITH VERY WARM TEMPERATURES THROUGH MONDAY. A COLD FRONT WILL
MOVE THROUGH AND COOL THINGS DOWN 10 TO 15 DEGREES FOR THE MIDDLE OF
THE WEEK...WITH A REINFORCEMENT OF COLD AIR ON THURSDAY BRINGING
TEMPERATURES CLOSER TO THE SEASONAL AVERAGE BY THE END OF THE WEEK.
NO SIGNIFICANT PRECIPITATION IS EXPECTED DURING THE NEXT FEW DAYS.
TODAY THROUGH MONDAY...EARLY MORNING WV IMAGERY TOGETHER WITH 500MB
HEIGHTS DEPICTED THE PREVALENT ZONAL FLOW ACROSS THE CONUS..WITH A
LARGE UPPER LEVEL TROUGH CRASHING ONSHORE THE PACIFIC NORTHWEST
BRING FLOODING RAINS ACROSS THE REGION...WITH HEAVY SNOW IN THE
HIGHER ELEVATIONS OF THE ROCKIES. AS THIS STORM SYSTEM MOVES EAST
IT WILL TRACK NORTH OF THE US/CANADA BORDER AND DEVELOP A
SIGNIFICANT SNOWSTORM ON THE NORTHERN SIDE. HOWEVER...THE COLD AIR
WILL BE WELL DISPLACED NORTH OF THE INTERNATIONAL BORDER...LEADING
TO TWO MORE DAYS OF SEASONABLY WARM WEATHER WITH HIGH TEMPERATURES
EXCEEDING 20 DEGREES ABOVE NORMAL. SOME LIGHT PRECIP IS POSSIBLE
AS THE COLD FRONT MOVES THROUGH FROM THE NORTHWEST ON MONDAY...BUT
THERMAL PROFILES ARE WARM ENOUGH THAT ALL PRECIP WILL BE IN LIQUID
FORM. THE LACK OF SIGNIFICANT SYNOPTIC SCALE FORCING MEANS THAT
ONCE AGAIN ONLY LIGHT RAINFALL TOTALS ARE EXPECTED...WITH
ACCUMULATIONS ONLY AROUND A FEW HUNDREDTHS.
TUESDAY THROUGH SATURDAY...THE POST FRONTAL AIR IS FAR FROM
ARCTIC...WITH TUESDAY AND WEDNESDAY HIGHS STILL RUNNING 5 TO 10
DEGREES ABOVE CLIMATOLOGY. BIGGEST CHANGE TO THE FORECAST WAS
LOWERING TUESDAY NIGHT LOW TEMPERATURES BELOW FORECAST GUIDANCE.
UPPER LEVEL SUBSIDENCE BENEATH THE UPSTREAM RIDGE AXIS WILL CAUSE A
SURFACE HIGH TO BUILD ACROSS THE REGION WHICH SHOULD PROMOTE
EXCELLENT RADIATIONAL COOLING BEFORE THE SOUTHERLY WINDS PICK UP ON
WEDNESDAY AHEAD OF THE NEXT APPROACHING WAVE. HOWEVER...LOW TEMPS
MAY STILL BE TOO WARM...ESPECIALLY CONSIDERING THE FACT THAT THEY
ARE STILL ABOVE CLIMO. THEREFORE WOULD NOT BE SURPRISED TO SEE
TEMPS CLOSER TO THE LOW TEENS AS COMPARED TO THE MID AND UPPER
TEENS CURRENTLY FORECAST. THE OTHER CONCERN WAS TRYING TO
DETERMINE THE PTYPE ON WEDNESDAY NIGHT/THURSDAY. THE 02.00
GEM...ECMWF...AND GFS ALL HAVE H850 TEMPS OF +2 TO +4C
OVERNIGHT...WITH GFS BUFR SOUNDINGS SHOWING EVEN WARMER
TEMPERATURES AROUND 900MB. THEREFORE EXPECTING ANY PRECIP THAT
FALLS TO MELT BEFORE IT REACHES THE SURFACE. HAVE OPTED TO INCLUDE
A RA/FZRA MIX FOR NOW...SINCE SURFACE TEMPS MAY FALL BELOW
FREEZING OVERNIGHT WEDNESDAY/EARLY THURSDAY MORNING. QPF AMOUNTS
WILL BE LIGHT. THIS WAVE WILL DRIVE ANOTHER COLD FRONT THROUGH
THE REGION...WHICH WILL HAVE A MORE SIGNIFICANT TEMPERATURE CHANGE.
HIGHS ON FRIDAY AND SATURDAY WILL RANGE FROM THE MID 20S TO LOWER
30S...WHICH IS RIGHT WHERE WE SHOULD BE FOR THIS TIME OF YEAR.
&&
.AVIATION.../06Z TAF ISSUANCE/
SEE UPDATE SECTION ABOVE FOR MANY ISSUES SURROUNDING FG. CURRENT
TAFS HAVE A PRETTY GOOD HANDLE ON THINGS AT THE MOMENT. PLENTY OF
LOW LEVEL MOISTURE /OUTSIDE OF SW MN/ AND LIGHT WINDS WILL RESULT
IN EXPANSION OF STRATUS AND FG AS MID CLOUDS ASSOCIATED WITH
POTENT SHORTWAVE NEAR MSP QUICKLY MOVE EAST. LOW CLOUDS WILL
LINGER INTO THE MORNING...BUT INCREASING SRLY WINDS AND INFLUX OF
DRIER AIR SHOULD LEAD TO RAPID IMPROVEMENTS IN CONDITIONS BETWEEN
14Z AND 15Z FOR MN AND POSSIBLY AS LATE AT 17Z OVER IN WI WHERE
WINDS WILL REMAIN CALM. ONCE THE FOG BURNS OFF...IT WILL BE VFR
CONDS WITH INCREASING S/SE WINDS AS A DEEP AREA BEGINS MOVING
ACROSS SRN CAN...WITH A STRONG COLD FRONT APPROACHING WRN MN BY
12Z MON. MAIN QUESTIONS FOR TAFS TONIGHT LIES WITH AXN AND RWF. FOR
AXN...STRATUS/FG DECK IS ABOUT TO MOVE IN WITH CONDITIONS VARYING
FROM 200 FEET AND 1/4SM TO 1K FT AND 3SM. FOR NOW...PLAYED THE IFR
CIG/VIS ROUTE...BUT IT COULD EASILY BE 1/4SM AND 200 FT LIKE FFM
CURRENTLY HAS. AT RWF...DRIER HAS FOUND ITS WAY THERE AND VIS
FORECASTS FROM BOTH THE GFSLAMP AND HRRR KEEP THE FOG TO THE NORTH
AND EAST...SO WENT OPTIMISTIC THERE.
KMSP...MID CLOUDS BEGINNING TO CLEAR THE AREA AND AS THEY MOVE
EAST...FOG FORMATION SHOULD BEGIN QUICKLY OUTSIDE OF THE URBAN
HEAT ISLAND. BIG QUESTION FOR FOG THOUGH IS WINDS. 1-MINUTE WIND
DATA HAS SHOWN FAIRLY PERSISTENT W-NW WINDS AROUND 5 KTS AND IF
THIS CONTINUES TO BE THE CASE...DENSE FOG WILL BE UNLIKELY AT THE
FIELD AS THINGS DRAIN INTO THE MN VALLEY. CONTINUED WITH THE TEMPO
GROUP...THOUGH LOWERED THE VIS TO 1/2SM. WITH TEMP/DEWP DEPRESSION
AT 0 DEGS AT 06Z...COULD SEE THAT TEMPO NEEDING TO BE THE
PREVAILING GROUP. AFTER THE MORNING FG/STRATUS CLEARS OUT...REST
OF THE TAF IS PRETTY STRAIGHT FORWARD.
/OUTLOOK FOR KMSP/
MON...MVFR CIGS POSSIBLE. CHANCE OF -RA. WIND S AT 10 KTS BECOMING WNW AT
15-20 KTS WITH LATE AFTERNOON FRONTAL PASSAGE.
TUE...VFR. WIND NW AT 10-15 KTS.
WED...VFR. WIND SE AT 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...FREEZING FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR ANOKA-
BENTON-BLUE EARTH-BROWN-CARVER-CHIPPEWA-CHISAGO-DAKOTA-
DOUGLAS-FARIBAULT-HENNEPIN-ISANTI-KANABEC-KANDIYOHI-LAC QUI
PARLE-LE SUEUR-MARTIN-MCLEOD-MEEKER-MILLE LACS-MORRISON-
NICOLLET-POPE-RAMSEY-REDWOOD-RENVILLE-RICE-SCOTT-SHERBURNE-
SIBLEY-STEARNS-STEVENS-SWIFT-TODD-WASECA-WASHINGTON-
WATONWAN-WRIGHT-YELLOW MEDICINE.
DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR FREEBORN-
GOODHUE-STEELE.
WI...FREEZING FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR BARRON-
POLK-RUSK-ST. CROIX.
DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR CHIPPEWA-DUNN-
EAU CLAIRE-PEPIN-PIERCE.
&&
$$
JRB/MPG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1200 AM CST SUN DEC 2 2012
.UPDATE...
06Z AVIATION DISCUSSION ADDED BELOW.
UPDATE ON THE FOG POTENTIAL TONIGHT. /ISSUED 933 PM CST SAT DEC 1
2012/
MANY QUESTION STILL EXIST WITH THE FOG TONIGHT...WITH MULTIPLE
SOURCES OF UNCERTAINTY ACROSS THE AREA.
1. SW MN. HERE...DRIER AIR WITH DEWPOINTS SLOWLY FALLING INTO THE
20S HAS OCCURRED HERE. GFSLAMP ALONG WITH HRRR VSBY FORECASTS SHOW
SW MN REMAINING WITH VSBYS IN EXCESS OF 3 MILES. THE QUESTION
BECOMES...HOW FAR EAST DOES THIS DRIER AIR MAKE IT. THE HRRR BRINGS
IT CLEAR OVER TO THE I-35 CORRIDOR...WHILE THE GFSLAMP BRINGS THE
DENSE FOG AS FAR WEST AS A FAIRMONT...LITCHFIELD... LITTLE FALLS
LINE. GIVEN MKT HAS ALREADY BEEN DOWN TO 1/2SM...WOULD FAVOR THE
GFSLAMP. THIS STILL KEEPS A LOT OF QUESTIONS GOING FOR LOCATIONS
WEST THOUGH.
2. CENTRAL MN. A DIFFERENT ISSUE UP HERE DEALS WITH STRATUS
DROPPING DOWN FROM NRN MN. RAP 925 MB RH WOULD BRING THESE CLOUDS
CLEAR DOWN TO RWF...AND IF THIS HAPPENED...MUCH OF OUR NORTHERN CWA
WOULD SEE ANOTHER NIGHT OF LOW STRATUS WITH MAINLY 1-3 MILE VSBYS.
3. WESTERN WI. ANOTHER STRATUS ISSUE HERE. THIS WOULD BE THE
STRATUS THAT HAS BEEN SLOWLY PUSH CLEAR OF ERN MN THIS EVENING.
THE RAP ALONG WITH THE HRRR SHOW THESE CLOUDS PUTTING ON THE
BREAKS AS THE LOW LEVEL WIND FIELD BACKS OFF. EAU CLAIRE AND
LADYSMITH WOULD HAVE THE GREATEST POTENTIAL OF NOT LOSING THE
STRATUS AND ENDING UP WITH LOW STRATUS AS OPPOSED TO FOG. HERE
THOUGH...WITH LADYSMITH...HAYWARD...AND BLACK RIVER FALLS ALREADY
1/2 MILE OR LESS WITHIN THE STRATUS DECK...IT IS PROBABLY SAFE TO
ASSUME THAT DENSE FOG WILL IMPACT WRN WI.
4. FOR THE ST. CROIX VALLEY...TWIN CITIES...AND DOWN TOWARD MKT
AND SOUTH CENTRAL MN...THINGS LOOK A BIT MORE FAVORABLE FOR FOG.
HERE...THE STRATUS HAS CLEARED OUT AND THE DRY AIR HAS NOT MADE
MUCH OF A PUSH AND STILL CONFIDENT DENSE FOG WILL BE PREVALENT
ONCE THE HIGH CLOUDS CLEAR OUT IN THE NEXT COUPLE OF
HOURS...ESPECIALLY CONSIDERING ACQ...FBL...AND SYN ARE ALREADY
OBSERVING FOG. THE ONLY QUESTION BECOMES HOW FAR EAST DOES THE DRY
AIR MAKE IT /HAVE ALREADY SEEN MKT GO FROM 1/2 TO 3 MILES VSBY/.
AT ANY RATE...WILL NOT MAKE AN CHANGES TO THE CURRENT FOG
ADVISORY...BUT AT THIS POINT IS LOOKING AT THE VERY LEAST THAT FOG
MAY BE A BIT QUESTIONABLE OUT IN WEST CENTRAL AND SW MN.
MPG
&&
.PREV DISCUSSION...
/ISSUED 510 PM CST SAT DEC 1 2012/
SHORT TERM...TONIGHT THROUGH MONDAY NIGHT.
A WEAK COLD FRONT...MORE LIKE A WIND SHIFT LINE...IS PUSHING
THROUGH MINNESOTA THIS AFTERNOON. CLEARING SKIES IMMEDIATELY
BEHIND THE FRONT HAS ALLOWED TEMPERATURES TO WARM TO A GREATER
EXTENT THERE THAN AHEAD OF THE FRONT WHERE LOW CLOUDS AND LIGHT
FOG PERSIST. TEMPERATURES RANGED FROM THE MID 50S IN THE MN RIVER
VALLEY OF SWRN MN TO THE UPPER 30S OR LOWER 40S ACROSS CENTRAL MN
AND WRN WI.
THERE ARE NO SIGNS OF DRIER BOUNDARY LAYER AIR OFF TO THE WEST AND
A SURFACE RIDGE OF HIGH PRESSURE IS EXPECTED TO BUILD OVERHEAD
TONIGHT. IDEAL RADIATIONAL COOLING CONDITIONS ARE EXPECTED...ASIDE
FROM SOME HIGH CLOUDS CURRENTLY OVER ERN SD WHICH SHOULD PASS OVERHEAD
THIS EVENING. WITH CURRENT DEW POINTS SEVERAL DEGREES ABOVE NORMAL
HIGH TEMPS...THINK THERE IS A GOOD CHANCE FOR WIDESPREAD DENSE
FOG TONIGHT. TEMPERATURES SHOULD DROP BELOW FREEZING AFTER
MIDNIGHT OVER JUST ABOUT THE ENTIRE AREA SO SOME FROST OR LIGHT
ICING MAY DEVELOP ON UNTREATED ROADWAYS. DECIDED TO POST A
FREEZING FOG ADVISORY FOR AREAS THAT STAND THE BEST CHANCE OF
DROPPING BELOW FREEZING FOR AT LEAST A FEW HOURS DURING THE
OCCURRENCE OF DENSE FOG. FARTHER EAST TOWARD THE EAU CLAIRE AND
ALBERT LEA AREAS THERE IS MORE UNCERTAINTY OF SUBFREEZING TEMPS SO
POSTED A DENSE FOG ADVISORY THERE.
UNCERTAINTY EXISTS WITH THE ONSET OF SUCH FOG...ESPECIALLY EAST.
VISIBILITIES HAVE BEEN RUNNING IN THE 1 TO 4 MILE RANGE ACROSS THE
EASTERN AREAS ALL DAY. THINK THE CLEARING LINE WILL SLOW ITS
PROGRESSION EAST AFTER SUNSET AND CLOUDS MAY HANG IN UNTIL LATE
TONIGHT IN THE EAU AREA. THEREFORE...DELAYED THE ADVISORY START
TIME UNTIL 09Z. HOWEVER...IF THE CLOUDS CLEAR QUICKER THAN
ANTICIPATED WE COULD SEE FOG BECOMING DENSE SEVERAL HOURS EARLIER.
THE EVENING SHIFT MAY NEED TO ADJUST THINGS AS TRENDS BECOME
ESTABLISHED.
THE FOG WILL DISSIPATE QUICKLY SUNDAY MORNING AS RETURN FLOW
DEVELOPS IN RESPONSE TO LOW PRESSURE PROPAGATING ACROSS THE
NORTHERN ROCKIES AND INTO THE DAKOTAS. THIS WILL KEEP TEMPS QUITE
MILD...BUT A WARM FRONT WILL BISECT THE AREA WITH A 20 DEG SPREAD
FROM NORTH TO SOUTH. SOME LOCATIONS COULD TOUCH 60 NEAR REDWOOD
FALLS AS 925 MB TEMPS RISE TO +12C. THE WARM FRONT WILL LIFT INTO
NORTHERN MN SUNDAY NIGHT.
LOW PRESSURE WILL TRACK WELL NORTH OF THE AREA AND A TRAILING
COLD FRONT WILL PUSH THROUGH MINNESOTA AND WESTERN WI MONDAY.
STILL LOOKS LIKE A DRY FRONT FOR THE MOST PART...BUT A FEW SHOWERS
ARE STILL POSSIBLE. MAINTAINED LOW CHC POPS FOR NRN AND ERN AREAS.
LONG TERM...TUESDAY THROUGH NEXT SATURDAY.
A SECOND COLD FRONT WILL SINK SOUTH ON TUESDAY WHICH WILL BRING
A RETURN OF THE POLAR AIR. EARLY HIGHS MAY REACH THE 40S AND 50S
BEFORE TEMPERATURES DROP INTO THE TEENS AND 20S BY LATE EVENING.
THIS FRONT TOO...LOOKS DRY.
HIGH PRESSURE WILL BUILD IN TUESDAY NIGHT AND PUSH SOUTHEAST
WEDNESDAY. MOISTURE ADVECTION AND SOMEWHAT MILDER AIR WILL TRY TO
RETURN WEDNESDAY AND WEDNESDAY NIGHT...BUT A SHALLOW COLD LAYER
COULD BRING WINTRY PRECIP CHANCES WEDNESDAY NIGHT AND THURSDAY
MORNING. AT THIS POINT IT DOES NOT LOOK LIKE ANYTHING MORE THAN A
TRACE TYPE EVENT. ANOTHER COLD FRONT WILL SINK THROUGH FRIDAY WITH
COLDER AIR TO FOLLOW INTO THE WEEKEND.
&&
.AVIATION.../06Z TAF ISSUANCE/
SEE UPDATE SECTION ABOVE FOR MANY ISSUES SURROUNDING FG. CURRENT
TAFS HAVE A PRETTY GOOD HANDLE ON THINGS AT THE MOMENT. PLENTY OF
LOW LEVEL MOISTURE /OUTSIDE OF SW MN/ AND LIGHT WINDS WILL RESULT
IN EXPANSION OF STRATUS AND FG AS MID CLOUDS ASSOCIATED WITH
POTENT SHORTWAVE NEAR MSP QUICKLY MOVE EAST. LOW CLOUDS WILL
LINGER INTO THE MORNING...BUT INCREASING SRLY WINDS AND INFLUX OF
DRIER AIR SHOULD LEAD TO RAPID IMPROVEMENTS IN CONDITIONS BETWEEN
14Z AND 15Z FOR MN AND POSSIBLY AS LATE AT 17Z OVER IN WI WHERE
WINDS WILL REMAIN CALM. ONCE THE FOG BURNS OFF...IT WILL BE VFR
CONDS WITH INCREASING S/SE WINDS AS A DEEP AREA BEGINS MOVING
ACROSS SRN CAN...WITH A STRONG COLD FRONT APPROACHING WRN MN BY
12Z MON. MAIN QUESTIONS FOR TAFS TONIGHT LIES WITH AXN AND RWF. FOR
AXN...STRATUS/FG DECK IS ABOUT TO MOVE IN WITH CONDITIONS VARYING
FROM 200 FEET AND 1/4SM TO 1K FT AND 3SM. FOR NOW...PLAYED THE IFR
CIG/VIS ROUTE...BUT IT COULD EASILY BE 1/4SM AND 200 FT LIKE FFM
CURRENTLY HAS. AT RWF...DRIER HAS FOUND ITS WAY THERE AND VIS
FORECASTS FROM BOTH THE GFSLAMP AND HRRR KEEP THE FOG TO THE NORTH
AND EAST...SO WENT OPTIMISTIC THERE.
KMSP...MID CLOUDS BEGINNING TO CLEAR THE AREA AND AS THEY MOVE
EAST...FOG FORMATION SHOULD BEGIN QUICKLY OUTSIDE OF THE URBAN
HEAT ISLAND. BIG QUESTION FOR FOG THOUGH IS WINDS. 1-MINUTE WIND
DATA HAS SHOWN FAIRLY PERSISTENT W-NW WINDS AROUND 5 KTS AND IF
THIS CONTINUES TO BE THE CASE...DENSE FOG WILL BE UNLIKELY AT THE
FIELD AS THINGS DRAIN INTO THE MN VALLEY. CONTINUED WITH THE TEMPO
GROUP...THOUGH LOWERED THE VIS TO 1/2SM. WITH TEMP/DEWP DEPRESSION
AT 0 DEGS AT 06Z...COULD SEE THAT TEMPO NEEDING TO BE THE
PREVAILING GROUP. AFTER THE MORNING FG/STRATUS CLEARS OUT...REST
OF THE TAF IS PRETTY STRAIGHT FORWARD.
/OUTLOOK FOR KMSP/
MON...MVFR CIGS POSSIBLE. CHANCE OF -RA. WIND S AT 10 KTS BECOMING WNW AT
15-20 KTS WITH LATE AFTERNOON FRONTAL PASSAGE.
TUE...VFR. WIND NW AT 10-15 KTS.
WED...VFR. WIND SE AT 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...FREEZING FOG ADVISORY UNTIL 9 AM CST SUNDAY FOR ANOKA-BENTON-
BLUE EARTH-BROWN-CARVER-CHIPPEWA-CHISAGO-DAKOTA-DOUGLAS-
FARIBAULT-HENNEPIN-ISANTI-KANABEC-KANDIYOHI-LAC QUI PARLE-
LE SUEUR-MARTIN-MCLEOD-MEEKER-MILLE LACS-MORRISON-NICOLLET-
POPE-RAMSEY-REDWOOD-RENVILLE-RICE-SCOTT-SHERBURNE-SIBLEY-
STEARNS-STEVENS-SWIFT-TODD-WASECA-WASHINGTON-WATONWAN-
WRIGHT-YELLOW MEDICINE.
DENSE FOG ADVISORY UNTIL 9 AM CST SUNDAY FOR FREEBORN-GOODHUE-
STEELE.
WI...FREEZING FOG ADVISORY UNTIL 9 AM CST SUNDAY FOR BARRON-POLK-RUSK-
ST. CROIX.
DENSE FOG ADVISORY UNTIL 9 AM CST SUNDAY FOR CHIPPEWA-DUNN-EAU
CLAIRE-PEPIN-PIERCE.
&&
$$
BORGHOFF/MPG
AREA FORECAST DISCUSSION
NWS BILLINGS MT
316 PM MST SUN DEC 2 2012
.SHORT TERM...VALID FOR MON AND TUE...
LATEST REPORTS FROM GAP FLOW AREAS...LARGE TREES DOWN IN
LIVINGSTON WITH GUSTS OVER 70 MPH COMMON. RECENT GUSTS TO 73 MPH
AT THE STILLWATER MINE. WINDS WILL SHIFT TO THE WEST LATE
TODAY/EARLY THIS EVENING WITH THE FRONTAL PASSAGE AND SHOULD
EFFECTIVELY DIMINISH THE THREAT OF HIGH WINDS...THOUGH THEY WILL
REMAIN BRISK AND GUSTY OUT OF THE WEST. AS A MATTER OF FACT...WE
MAY NEED A WIND ADVISORY FOR MONDAY OR MONDAY NIGHT INTO TUESDAY
IN THE GAP FLOW AREAS AS A FAVORABLE PRESSURE GRADIENT QUICKLY
REBOUNDS AND SETS UP AGAIN WITH LEE SIDE TROUGHING AND ZONAL FLOW
ALOFT. WILL NOT MUDDY THE WATERS BY ISSUING THIS NOW...BUT HAVE
BUMPED UP WINDS MONDAY THROUGH TUESDAY AT LIVINGSTON AND THE
FOOTHILLS.
MOUNTAIN WAVE CONCERNS...CROSS SECTIONS OVER THE RED LODGE
FOOTHILLS FROM THIS MORNINGS MODEL CYCLE CONTINUE TO INDICATE
MODERATE OR LITTLE DOWNWARD MOMENTUM SHIFT. SO SIGNIFICANT MOUNTAIN
WAVE ACTIVITY THERE IS NOT EXPECTED...HOWEVER GUSTS TO 58 MPH HAVE
BEEN OBSERVED AS LOW AS TIPI VILLAGE NEAR 6000 FT...AND THIS MAY
CONTINUE INTO THE EARLY EVENING.
SHERIDAN IS MY MAIN CONCERN THIS EVENING. GFS AND RAP SOUNDINGS
SHOW OVER 60 KTS JUST BELOW 2500 FT AGL WITH A DISTINCT CRITICAL
LAYER. STRONG NORTHWESTERLY SWITCH WITH THE FRONTAL PASSAGE
AROUND 9-10 PM WITH IMPRESSIVE POST FRONTAL PRESSURE RISES MOVING
NW TO SE. THE ONLY THING AGAINST SOME TYPE OF HIGH WIND IS THE SW
TO NE ORIENTATION OF THE JET. HOWEVER...FEEL THERE IS A
SIGNIFICANT THREAT AS THESE TYPE OF EVENTS AND PROFILES ARE
GENERALLY RARE. CONFIDENCE HIGH FOR FOOTHILLS ABOVE
SHERIDAN...LOWER FOR ACTUALLY OCCURRING IN SHERIDAN. WILL ISSUE A
HIGH WIND WARNING THROUGH 07Z FOR SHERIDAN FOOTHILLS. WILL DISCUSS
THIS BEING A BRIEF 2 HOUR EVENT AT SOME POINT THIS EVENING.
CLOUD COVER MAY BE RESPONSIBLE FOR LIMITING AND MODIFYING THE
VERTICAL ATMOSPHERE PROFILES WE EXPECTED TODAY AS STRONG WINDS
HAVE NOT YET OCCURRED AT BIG TIMBER NOR UP TO JUDITH GAP. HOWEVER
...THERE IS STILL A DECENT POTENTIAL FOR STRONG WINDS TO DEVELOP
IN THIS AREA THROUGH EVENING FROM BIG TIMBER TO HARLOWTON AND
JUDITH GAP. WE HAVE A DYNAMIC AND PROGRESSIVE TROUGH MOVING ACROSS
THIS EVENING WITH STRONG SUBSIDENCE BEHIND THE ASSOCIATED COLD
FRONT. THEREFORE WILL KEEP HIGHLIGHTS GOING AT JUDITH GAP AND
IN SWEET GRASS.
WINTER STORM WARNING...ACCORDING TO THE LATEST NORMALIZED WATER
VAPOR PROGGS...THE DEEPEST MOISTURE FETCH FROM THE PACIFIC WILL
AFFECT THE ABSAROKA/BEARTOOTH MOUNTAINS BETWEEN 18Z AND 00Z THIS
EVENING. CROSS SECTIONS INDICATE DECENT LIFT AND OROGRAPHIC
FORCING ON THE SOUTH AND WEST FACING SLOPES AT THIS TIME. ANY
HEAVY SNOWFALL ACCUMULATIONS WILL LIKELY BE AT OR ABOVE 7500 TO
8000 FEET WHICH IS ABOUT WHERE THE FREEZING LEVEL IS AT THIS
AFTERNOON...AND COOKE CITY WEB CAMS AND SPOTTER REPORTS SHOW
MELTING SNOW AND LITTLE ACCUMULATION LOWER. WIND GUSTS AT RAWS
STATIONS IN THE HIGH COUNTRY ARE COMMONLY SEEING 60
MPH. THEREFORE...THE WINTER STORM WARNING ABOVE 7000 FEET LOOKS
OKAY INTO THE EVENING...AND DOES NOT NEED TO BE ADJUSTED.
HOWEVER...WE MAY BE ABLE TO CANCEL IT EARLY. BT
.LONG TERM...VALID FOR WED...THU...FRI...SAT...SUN...
ONLY MINOR CHANGES TO THE EXTENDED PERIOD...AS MODELS CONTINUE IN
GOOD AGREEMENT UNTIL LATE IN THE WEEK....WITH GFS FAVORING MORE
AMPLIFIED NORTHWEST FLOW ALOFT LATE IN THE PERIOD. THE BEGINNING
OF THE PERIOD CONTINUES TO LOOK SOMEWHAT UNSETTLED. AS FOR
TEMPS...A GENERAL COOLING TREND APPEARS TO BE ON TAP FOR EXTENDED
PERIOD.
WEAK PACIFIC SHORTWAVES ARE PROGGED TO MOVE ACROSS THE REGION WEDNESDAY
NIGHT THROUGH EARLY FRIDAY. HAVE CONTINUED WITH INHERITED POPS AT
THIS TIME...AS STILL CANNOT PIN POINT TIMING MUCH BETTER. MODELS
CONTINUE TO INDICATE DEEPENING UNSETTLED NORTHWEST FLOW THROUGH
THE END OF THE PERIOD...BUT GFS INDICATES A STRONG SHORTWAVE TROF
DIGGING ACROSS THE NORTHERN ROCKIES...OPENING THE DOOR FOR COLDER
AIR TO SLIDE SOUTH OUT OF CANADA. LATEST EC LOOKS LIKE IT
BEGINNING TO LEAN TOWARD THE GFS...ALTHOUGH TIMING IS A BIT OFF.
CONTINUED WITH COLDER TEMPS...AND CONTINUE PRECIP POTENTIAL TO END
THE EXTENDED PERIOD. AAG
&&
.AVIATION...
VERY STRONG AND GUSTY SOUTHWEST WINDS WILL CONTINUE FOR AREAS
WEST OF KBIL...INCLUDING BIG TIMBER...JUDITH
GAP...HARLOWTON...LIVINGSTON...RED LODGE...KLVM...AND THE PARADISE
VALLEY. GUSTS AS HIGH AS 65 KNOTS HAVE BEEN REPORTED IN AND AROUND
KLVM...INCLUDING IN THE PARADISE VALLEY. GUSTS OF 35 TO 50 KNOTS
ARE EXPECTED FROM BIG TIMBER NORTH TO JUDITH GAP. WINDS ARE
EXPECTED TO PERSIST THROUGH THIS EVENING. WINDS ARE EXPECTED TO
TURN WESTERLY LATE THIS EVENING...BUT REMAIN GUSTY
OVERNIGHT...ESPECIALLY WEST OF KBIL. A PERIOD OF VERY STRONG AND
GUSTY WINDS IS EXPECTED TO IMPACT SHERIDAN AND THE BIGHORN
FOOTHILLS THIS EVENING...WITH GUSTS AROUND 60 KNOTS IN THE
FOOTHILLS...AND 50 KNOTS POSSIBLE INTO SHERIDAN. LOW LEVEL
TURBULENCE IS POSSIBLE ACROSS EASTERN ROUTES...FROM KBIL
EAST...AS WIND SPEED INCREASES RAPIDLY JUST ABOVE THE SURFACE.
VFR CONDITIONS ARE EXPECTED TO PREVAIL ACROSS THE AREA...WITH THE
EXCEPTION OF SNOW OVER THE BEARTOOTH/ABSAROKA MOUNTAINS...WHERE
SNOW AND WIND WILL COMBINE TO REDUCE VISIBILITIES. AAG
&&
.PRELIMINARY POINT TEMP/POPS...
MON TUE WED THU FRI SAT SUN
-----------------------------------------------------------
BIL 038/053 030/049 038/053 032/041 025/041 027/037 022/026
20/N 00/B 01/B 32/W 32/W 11/B 33/J
LVM 038/046 032/047 038/053 030/041 019/040 026/032 020/026
41/N 11/N 12/W 32/W 22/J 12/W 22/J
HDN 034/055 026/049 030/054 029/042 025/040 022/037 023/028
30/N 00/U 01/B 32/W 32/W 12/W 33/J
MLS 036/052 024/048 029/052 029/039 019/036 021/035 018/027
20/N 00/B 01/B 32/W 22/J 12/J 33/J
4BQ 036/053 024/050 029/055 030/042 021/037 021/036 021/027
30/N 00/U 01/B 32/W 32/J 02/J 33/J
BHK 035/048 023/046 027/049 025/035 016/032 021/031 018/025
30/N 00/U 00/B 22/J 22/J 02/J 33/J
SHR 030/045 022/046 028/050 025/037 020/034 017/031 017/022
20/B 00/U 01/B 33/J 33/J 12/J 33/J
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...WIND ADVISORY IN EFFECT UNTIL 10 PM MST THIS EVENING FOR ZONE
41.
HIGH WIND WARNING IN EFFECT UNTIL 10 PM MST THIS EVENING FOR
ZONES 63>66.
WINTER STORM WARNING IN EFFECT UNTIL 6 AM MST MONDAY ABOVE
7000 FEET FOR ZONE 67.
WY...HIGH WIND WARNING IN EFFECT UNTIL MIDNIGHT MST TONIGHT FOR
ZONE 99.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS GLASGOW MT
1014 AM MST SUN DEC 2 2012
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH TUESDAY...
UPDATED THE FORECAST TO SPREAD POPS FARTHER EAST AND SOUTH THIS
MORNING AND AFTERNOON. FROM WHAT THE CURRENT RADAR TREND AND WHAT
THE LATEST HRRR MODEL OUTPUT WAS SHOW...THE RAIN IS LIKELY TO BE
A LITTLE MORE WIDESPREAD THEN WHAT THE LATEST 12Z NAM/GFS WERE
SHOWING FOR THIS AFTERNOON. THE REST OF THE SHORT TERM FORECAST
AND HIGH WIND HIGHLIGHTS LOOK GOOD. RSMITH
PREVIOUS DISCUSSION...WITH A GLANCE AT WATER VAPOR IMAGERY AND
500 MB HEIGHT FIELD...THE LATE WEEKEND STORM SYSTEM SEEMS TO HAVE
BEGUN ACROSS THE PACIFIC NORTHWEST AND NORTHERN ROCKIES REGION.
THE UPPER LEVEL TROUGH IS DEEPENING AND NARROWING JUST NW OF THE
PUGET SOUND. A SIGNIFICANT PLUME OF PACIFIC MOISTURE HAS NOW
SPREAD FROM NORTHERN CALIFORNIA TO SEATTLE AND FROM SOUTHERN IDAHO
TO WESTERN MONTANA.
FORECAST CHALLENGES INCLUDE FREEZING FOG THIS MORNING...PRECIP
TIMING...AMOUNT...AND TYPE FROM TODAY THROUGH EARLY MONDAY MORNING
AND AREAS OF VERY STRONG WINDS FROM TONIGHT THROUGH MONDAY NIGHT.
PERSISTENT FREEZING FOG HAS INTERMITTENTLY EXPANDED AND CONTRACTED
OVER THE MID TO LOWER RIVER VALLEYS THROUGHOUT THE OVERNIGHT
HOURS. WITH SUCH A STRONG INVERSION AT THE SURFACE...WOULD EXPECT
THE FOG TO HOLD ON UNTIL WARMER TEMPERATURES FROM THE SOUTH HELP
TO DISSIPATE THE FOG LATER TODAY. HEADLINE FOR A DENSE FOG
ADVISORY HAS IT WELL IN HAND. WOULD EXPECT THE FOG TO BE LIMITED
TO AREAS JUST ALONG AND VERY NEAR THE RIVER VALLEYS AND OTHER
DRAINAGES.
INITIALLY...THE FORECAST IS A LITTLE TRICKY BUT THE CURRENT
THINKING IS THAT DURING THE MORNING HOURS TODAY...THE STRONG
SURFACE INVERSION REMAINS IN PLACE AS PRECIPITATION BEGINS TO
EMERGE ACROSS CENTRAL MONTANA AND SNEAK INTO OUR WESTERN AND
NORTHWESTERN ZONES. MID LEVEL AND JUST ABOVE THE INVERSION
TEMPERATURES ARE WARM ENOUGH FOR RAIN...BUT THE NARROW LAYER OF
COLDER MORNING TEMPERATURES MAY IN FACT REFREEZE THAT RAIN JUST AS
IT REACHES THE SURFACE.
THIS AFTERNOON...TEMPERATURES WILL WARM ENOUGH TO CHANGE ALL
PRECIP TO RAIN AS THE FOG DISSIPATES...AT LEAST TEMPORARILY.
THROUGH THE AFTERNOON AND EARLY EVENING HOURS...THE FORCING FOR
ASCENT AND AREAS OF RAIN TRANSITION MORE TOWARD OUR NORTHERN
ZONES AS STRONG SUBSIDENCE TAKES OVER WITH A SHIFT IN WINDS FROM
THE WEST.
TONIGHT...STRONGER WESTERLY WINDS WILL SPILL INTO EASTERN MONTANA.
MOST LOCATIONS ACROSS OUR WESTERN...CENTRAL AND SOUTHERN ZONES
WILL EASILY EXPERIENCE STRONG GUSTY WINDS IN THE 35G45 KT
RANGE...BUT WOULD LIKELY NOT QUITE REACH HIGH WIND CRITERIA. THE
TYPICALLY SUSCEPTIBLE AREAS FOR HIGH WINDS IN SUCH
SITUATIONS...SUCH AS SW PHILLIPS COUNTY HAS RECENTLY HAD
CONSISTENT MODEL SUPPORT FOR EVEN HIGHER WINDS AND HAS BEEN
UPGRADED TO A HIGH WIND WARNING. THE SLOPES OF THE LITTLE ROCKIES
AND THE STRETCH OF US HIGHWAY 191 SOUTH OF MALTA WILL LIKELY
EXPERIENCE WIND GUSTS IN EXCESS OF 60 MPH. DO NOT SEE ENOUGH SHORT
TERM MODEL SUPPORT OR CONSISTENCY TO INCLUDE ANY OTHER ZONES IN
THE WARNING DOWNSTREAM AT THIS TIME. THIS COLD FRONT WILL BRING A
NOTICEABLE DROP IN TEMPERATURES FOR NE MONTANA BUT NOT NEAR AS
DRASTIC OF A DROP AS JUST OVER THE CANADIAN BORDER. THE WORST OF
IT QUICKLY PASSES ALONG TO OUR NORTHEAST.
MONDAY THROUGH MONDAY NIGHT...PRECIP PUSHES WELL AWAY FROM
NORTHEAST MONTANA AS NORTHWESTERLY UPPER LEVEL FLOW GRADUALLY
TRANSITIONS TO A WEAK RIDGE BY TUESDAY.
TEMPERATURES TOWARD THE END OF THIS FORECAST PERIOD WILL REMAIN ON
THE COOL SIDE BUT NOT SIGNIFICANTLY COLD AS THE CANADIAN ARCTIC
INFLUENCE IS BUFFETED SOMEWHAT BY HIGHER PRESSURES FROM THE SOUTH.
BMICKELSON
.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY...
UPPER RIDGE WILL TO THE EAST TUESDAY NIGHT AND WEDNESDAY. UPPER
TROUGH WILL MOVE ACROSS THE CANADIAN PRAIRIES AND MONTANA
WEDNESDAY AND WEDNESDAY NIGHT WHICH WILL BRING A COLD FRONT
THROUGH THE FORECAST AREA WEDNESDAY AFTERNOON AND EVENING. LIMITED
MOISTURE WITH THIS SYSTEM BUT A FEW RAIN SHOWERS REMAINS POSSIBLE
ON WEDNESDAY SWITCHING TO SNOW SHOWERS WEDNESDAY NIGHT AS
TEMPERATURES FALL. WILL MENTION A SLIGHT CHANCE FOR NOW.
NORTHWEST FLOW ALOFT WILL PREVAIL FROM THURSDAY INTO THE WEEKEND WITH
COLDER AIR MASS IN PLACE. COULD SEE A SNOW SHOWER ON THURSDAY WITH
A SHORTWAVE IN THE NORTHWEST FLOW ALOFT. CANADIAN HIGH PRESSURE
WILL KEEP WEATHER DRY THURSDAY NIGHT AND FRIDAY. THE MODEL
DIFFERENCES START APPEARING TOWARDS THE WEEKEND WITH ECMWF
MAINTAINING NORTHWEST FLOW ALOFT WITH SHORTWAVES WHILE GFS WANTS
TO DIG AN UPPER TROUGH OVER MONTANA. EITHER WAY...THERE IS SOME
POTENTIAL FOR SNOW WITH THE GFS ADVERTISING A BETTER CHANCE THAN
THE ECMWF. WILL MENTION EITHER A CHANCE OR SLIGHT CHANCE OF SNOW
FOR NOW. FORRESTER
&&
.AVIATION...
SOME PATCHY FOG REMAINS IN THE MISSOURI RIVER VALLEY THIS
MORNING...KEEPING VISIBILITY MVFR AT KOLF THROUGH LATE MORNING.
OTHERWISE SOUTHERLY WINDS AROUND 10 KNOTS WILL DEVELOP AND DRIER
AIR ALOFT WILL MIX DOWN TO THE SURFACE BY EARLY AFTERNOON...KEEPING
CONDITIONS VFR. A MIX OF MID AND HIGH CLOUDS CAN BE EXPECTED MOST
OF TODAY AND TONIGHT.
A COLD FRONT IN THE LATE AFTERNOON OR EARLY EVENING WILL BRING A
CHANCE OF RAIN ESPECIALLY TO KGGW AND KOLF THAT MAY TURN TO SNOW
DURING THE EVENING. WEST WINDS 15 TO 25 KNOTS WITH HIGHER GUSTS
WILL DEVELOP THIS EVENING AND CONTINUE OVERNIGHT AND INTO MONDAY.
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING FROM 2 PM THIS AFTERNOON TO 11 PM MST MONDAY
FOR SOUTHWEST PHILLIPS.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS BILLINGS MT
357 AM MST SUN DEC 2 2012
.SHORT TERM...VALID FOR TDY AND MON...
SIGNIFICANT SURFACE PRESSURE FALLS ARE BEING OBSERVED ALREADY THIS
MORNING ACROSS THE NORTHERN ROCKIES...WHICH IS A HARBINGER OF HIGH
WINDS THAT WILL OCCUR TODAY AND THIS EVENING ACROSS PARTS OF SOUTH
CENTRAL MT. THERE IS STILL SOME UNCERTAINTY IN THE DETAILS OF THIS
WIND EVENT AS A RELATIVELY DEEP SURFACE LOW SCOOTS ACROSS NORTHERN
MT...BUT WE ARE VERY CONFIDENT THAT AT LEAST THE LIVINGSTON TO NYE
AND BIG TIMER AREAS WILL HAVE VERY STRONG WINDS.
TODAY...LOW- AND MID-LEVEL SOUTHWEST FLOW RAMPS UP QUICKLY...WHICH
YIELDS 700-HPA WINDS ON THE ORDER OF 70 TO 80 KT AROUND LIVINGSTON
DURING THE MORNING. FORECAST SOUNDINGS STILL CALL FOR A RELATIVELY
STABLE LAYER NEAR THE MOUNTAIN-TOP LAYER...AND SINCE GAP WINDS ARE
ALREADY INCREASING AS OF 10 UTC...THAT IDEA IS LIKELY CORRECT. THE
SCENARIO SHOULD EASILY YIELD SUSTAINED WINDS NEAR 50 MPH AND GUSTS
PERHAPS CLOSE TO 80 MPH AROUND LIVINGSTON...ESPECIALLY DURING LATE
MORNING WHEN 5 HPA/3 HOUR SURFACE PRESSURE FALLS ARE CENTERED OVER
NORTHERN ID. BY 18 UTC...THE BOUNDARY LAYER WILL BECOME WELL-MIXED
AND CAUSE WINDS EVEN OUTSIDE OF THE GAP AREAS TO GET STRONG...WITH
BIG TIMBER THEN LIKELY TO TAP INTO 50 KT FLOW ABOVE THE GROUND. WE
DID...HOWEVER...DECIDE TO CANCEL THE HIGH WIND WATCH FOR HARLOWTON
AND RYEGATE BECAUSE THE 00 UTC NAM AND RECENT RAP AND HRRR RUNS DO
NOT REVEAL QUITE ENOUGH PRE-FRONTAL LOW-LEVEL WIND FOR A WARNING.
NOTE THAT THE 00 UTC GFS...WHICH IS A BIT OF AN OUTLIER...SHOWS 60
KT 500 M AGL WINDS IN THOSE AREAS IN THE LATE AFTERNOON THOUGH. WE
DID DECIDE TO GO WITH A HIGH WIND WARNING FOR JUDITH GAP...BANKING
ON TERRAIN ENHANCEMENT OF SOUTHERLY FLOW IN THAT AREA TO PUSH WIND
SPEEDS UP AS THE PRESSURE FALLS PASS NORTH OF THE AREA. WE WILL BE
KEEPING A CLOSE EYE ON THE PARADISE VALLEY FOR THAT TOO...BUT MOST
HIGH-RESOLUTION GUIDANCE SUGGESTED SPEEDS JUST SHORT OF WHAT WOULD
BE NEEDED FOR A WARNING THERE. ADMITTEDLY...WE DO NOT HAVE MUCH IN
THE WAY OF ANALOGS FOR HIGH WINDS IN THE PARADISE VALLEY...AND OUR
CONFIDENCE IN THAT DECISION IS THUS LOW.
IN THE MOUNTAINS...THE WINTER STORM WARNING REMAINS IN PLACE...AND
IT STILL LOOKS LIKE THE MAIN IMPACT WILL BE FROM VERY STRONG WINDS
IN COMBINATION WITH SNOW /WHICH ITSELF WOULD NOT BE ENOUGH FOR THE
WARNING/. MOUNTAIN-TOP WINDS FROM THE HIGHER-RESOLUTION MODELS ARE
STILL ON THE ORDER OF 80 KT. GUIDANCE STILL DID NOT SHOW ENOUGH OF
A WELL-DEFINED CRITICAL LAYER OF SPEED SHEAR TO MAKE US ANTICIPATE
MOUNTAIN-WAVE-INDUCED HIGH WINDS AT RED LODGE...BUT THE 00 UTC NAM
DID ACTUALLY SUGGEST A BIT MORE MOMENTUM TRANSFER DOWN THE SLOPES.
THUS...WE WILL NEED TO KEEP AN EYE ON THAT DURING THE DAY TODAY.
TONIGHT...A SURFACE COLD FRONT WILL CROSS THE AREA...WHICH WILL BE
ACCOMPANIED BY 5-7 HPA/3 HOUR SURFACE PRESSURE RISES...MAINLY FROM
HARLOWTON AND LIVINGSTON TO BILLINGS AND SHERIDAN. THE ISALLOBARIC
COMPONENT OF THE WINDS THUS COULD BE SIGNIFICANT...WHICH DOES MAKE
US CONCERNED THAT WE COULD END UP WITH HIGH POST-FRONTAL WINDS FOR
A TIME. FORECAST SOUNDINGS...ESPECIALLY FROM THE 00 UTC NAM...EVEN
KEEP THE BOUNDARY LAYER WELL-MIXED WITH THE FRONTAL PASSAGE. WINDS
IN THE MIXED LAYER PEAK JUST UNDER 50 KT THOUGH...SO THERE WAS NOT
ENOUGH CONFIDENCE TO ADD ANY WIND HEADLINES IN AREAS LIKE BILLINGS
OR SHERIDAN OVERNIGHT. ACTUALLY...WE WILL HAVE TO KEEP A CLOSE EYE
ON SHERIDAN FOR THE POSSIBILITY OF MOUNTAIN WAVE ACTIVITY NEAR THE
FRONTAL PASSAGE TOO...THOUGH AGAIN MODEL-DERIVED CROSS SECTIONS DO
NOT SHOW A STRONG SIGNATURE FOR MOMENTUM TRANSFER ALL THE WAY DOWN
TO THE SURFACE IN THE LEE OF THE BIG HORNS. THERE WERE A FEW HINTS
IN THE 00 UTC GUIDANCE OF GREATER MOMENTUM TRANSFER THAN WHAT PAST
RUNS SUGGESTED THOUGH. OUTSIDE OF WIND ISSUES...WE DID MAINTAIN 20
TO 30 POPS WITH THE PASSAGE OF THE LOW- AND MID-LEVEL FRONT...WITH
SOME CLUSTERING OF MODEL QPF OUTPUT EVEN NOTED AROUND BROADUS.
MON...WESTERLY LOW- AND MID-LEVEL FLOW WILL BE IN PLACE...AND THAT
DOWNSLOPE SIGNATURE AND EFFICIENT MIXING TO AROUND 700 HPA WILL BE
ENOUGH TO PUSH HIGHS ON THE PLAINS OVER 50 F AGAIN. THE SUBSIDENCE
ALOFT SHOWN BY 500-300 HPA Q-VECTOR DIVERGENCE SUGGESTS THERE WILL
EVEN BE A GOOD AMOUNT OF SUN TO HELP OUT...SO WE ADJUSTED FORECAST
HIGHS UPWARD...CLOSE TO THE 00 UTC MAV OUTPUT. THAT MOS OFTEN DOES
WELL ON DAYS WITH DOWNSLOPE-AIDED WARMING DURING THE WINTER ON THE
HIGH PLAINS AND FRONT RANGE WHEN THERE IS SUNSHINE. THE 00 UTC GFS
AND NAM BOTH CALL FOR MIXED-LAYER WINDS OF 30 T0 35 KT...WITH PEAK
SPEEDS AT ITS TOP NEAR 45 KT...SO IT WILL DEFINITELY BE WINDY. THE
LACK OF NOTABLE COLD AIR ADVECTION SUGGESTS HEADLINE-WORTHY SPEEDS
ARE UNLIKELY OVER THE PLAINS OF SOUTH CENTRAL AND SOUTHEASTERN MT.
HOWEVER...THE 00 UTC MET AND MAV MOS BOTH SUGGEST WE COULD NEED AN
ADVISORY AROUND LIVINGSTON AGAIN. SCHULTZ
.LONG TERM...VALID FOR TUE...WED...THU...FRI...SAT...
MEDIUM RANGE GUIDANCE IN RELATIVELY GOOD AGREEMENT THROUGH MUCH OF
THE PERIOD UNTIL MODELS DIVERGE A BIT LATE IN THE WEEK AND INTO
THE WEEKEND. THE GFS BEGINNING TO ADVERTISE A VIGOROUS SHORTWAVE
TROUGH DIGGING ACROSS THE NORTHERN ROCKIES...DEEPENING THE TROUGH
AND OPENING THE DOOR FOR COLDER AIR TO SLIDE SOUTH OUT OF CANADA.
LATEST ECMWF SEEMS TO BE FALLING IN LINE WITH THIS SOLUTIONS BUT
THE TIMING BETWEEN THE TWO IS OUT OF PHASE. SEEMS LIKE THE BEST
THAT CAN BE SAID AT THIS POINT IS MODELS ARE SUGGESTIVE OF MORE
AMPLIFIED NORTHWEST FLOW ALOFT BY LATE WEEK AND INTO NEXT WEEKEND
WHICH IS SUPPORTIVE OF COOLER TEMPERATURE AT OR BELOW SEASONAL
NORMALS. THIS ALSO INCREASE THE THREAT FOR AT LEAST THE
POSSIBILITY OF SOME LIGHT SNOW AS LOW-LEVEL BAROCLINIC ZONE WOULD
BE DRAPED ACROSS THE AREA.
EARLIER IN THE PERIOD...WEAK PACIFIC SHORTWAVES ARE SLATED TO MOVE
ACROSS THE AREA WEDNESDAY NIGHT THROUGH EARLY FRIDAY. HAVE
INDICATED BETTER THREAT FOR AT LEAST SOME SHOWERS ACROSS THE AREA
DURING THIS TIME. AT THIS POINT...COULD NOT ISOLATE A PARTICULAR
12 HOUR PERIOD..BUT INSTEAD BROADBRUSHED THE 36 HOUR PERIOD AS THE
BEST THREAT FOR SOME PRECIPITATION.
INCREASED THREAT FOR PRECIPITATION AGAIN ON SATURDAY AND INTO
SUNDAY TO INDICATE POSSIBILITY OF COLD FRONT SLIPPING SOUTHWARD
FROM CANADA BRINGING POSSIBILITY OF SOME LIGHT SNOW. THE WEEKEND
PERIOD WILL NEED TO BE WATCHED CLOSELY TO SEE HOW THIS EVOLVES.
MEIER
&&
.AVIATION...
MAIN AVIATION HAZARD TODAY AND TONIGHT WILL BE WINDS. OTHERWISE
VFR CONDITIONS ARE EXPECTED TO PREVAIL ACROSS THE AREA...WITH THE
EXCEPTION OF OVER THE BEARTOOTH AND ABSAROKA MOUNTAINS WHERE SNOW
AND WIND WILL COMBINE TO REDUCE VISIBILITIES.
ALREADY GUSTY SOUTHWEST WINDS WILL INCREASE THIS MORNING FROM
LIVINGSTON AND ALONG THE FOOTHILLS OF THE BEARTOOTH MOUNTAINS.
EXPECT WINDS TO GUST AS HIGH AS 65 KNOTS IN THE VICINITY OF
LIVINGSTON...WITH GUSTS 35 TO 50 KNOTS FROM BIG TIMBER NORTH TO
JUDITH GAP. WINDS ARE EXPECTED TO PERSIST INTO THE SUNDAY
EVENING...BEFORE SWITCHING TO WESTERLY AND REMAINING FAIRLY GUSTY
SUNDAY NIGHT...ESPECIALLY THOSE AREAS WEST OF BILLINGS. MEIER
&&
.PRELIMINARY POINT TEMP/POPS...
TDY MON TUE WED THU FRI SAT
-------------------------------------------------------
BIL 059 038/054 031/049 035/053 032/041 025/041 027/037
0/N 20/N 00/B 01/B 32/W 32/W 11/B
LVM 057 038/047 032/047 033/053 030/041 019/040 026/032
3/W 41/N 11/N 12/W 32/W 22/J 12/W
HDN 058 034/057 026/048 030/054 029/042 025/040 022/037
0/N 20/N 00/U 01/B 32/W 32/W 12/W
MLS 059 036/053 025/047 029/052 029/039 019/036 021/035
0/B 30/N 00/U 01/B 32/W 22/J 12/J
4BQ 061 036/055 026/049 030/055 030/042 021/037 021/036
0/N 30/N 00/U 01/B 32/W 32/J 02/J
BHK 059 035/049 024/045 028/049 025/035 016/032 021/031
0/B 30/N 00/U 00/B 22/J 22/J 02/J
SHR 060 030/048 022/045 028/050 025/037 020/034 017/031
0/N 20/N 00/U 01/B 33/J 33/J 12/J
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...WIND ADVISORY IN EFFECT FROM 9 AM THIS MORNING TO 10 PM MST
THIS EVENING FOR ZONE 41.
HIGH WIND WARNING IN EFFECT FROM 9 AM THIS MORNING TO 10 PM
MST THIS EVENING FOR ZONE 63.
HIGH WIND WARNING IN EFFECT UNTIL 10 PM MST THIS EVENING FOR
ZONES 65-66.
WINTER STORM WARNING IN EFFECT UNTIL 6 AM MST MONDAY ABOVE
7000 FEET FOR ZONE 67.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
958 PM EST MON DEC 3 2012
.SYNOPSIS...
MILD TEMPERATURES WILL CONTINUE AHEAD OF A COLD FRONT...EXPECTED TO
CROSS THE EASTERN CAROLINAS ON WEDNESDAY. SCATTERED SHOWERS WILL
ACCOMPANY THE FRONT. COOLER CONDITIONS ARE EXPECTED AS HIGH PRESSURE
BUILDS OVER THE REGION THURSDAY AND FRIDAY...WITH MODERATING
TEMPERATURES NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 930 PM MONDAY...THE BROAD CENTER OF 1026 MB HIGH PRESSURE IS
LOCATED MAYBE A HUNDRED MILES OFFSHORE...BUT A ZONE OF VERY WEAK
PRESSURE GRADIENT EXTENDS AS FAR WEST AS GEORGIA. ALTHOUGH SURFACE
WINDS ARE VERY LIGHT OR CALM THERE IS A LITTLE BETTER RETURN FLOW
ABOVE THE SURFACE IN THE 1000-2000 FT AGL LAYER...ABOUT 10-12 KNOTS.
ALTHOUGH NOT AS WIDESPREAD AS LAST NIGHT...SATELLITE IMAGERY REVEALS
AN AREA OF ALTOCUMULUS ALONG THE SOUTH CAROLINA COAST WITH BASES IN
THE 7000-8000 FT RANGE. THIS CLOUD COVER APPEARS TO BE RELATED TO
MOISTURE TRAPPED UNDERNEATH THE SUBSIDENCE INVERSION ALOFT AND SOME
WEAK LIFT ALONG THE UPWARD-SLOPING 295K TO 300K ISENTROPIC SURFACES.
WHILE I WOULD LIKE TO SAY THESE CLOUDS WILL NOT BE WITH US MUCH
LONGER...NAM AND RUC MODELS SHOW CONTINUED MOISTURE AND WEAK LIFT
WHICH MAY SUPPORT SOME CLOUDS ALONG THE COAST THROUGH DAYBREAK.
THE AMOUNT OF CLOUD COVER IS CRITICALLY IMPORTANT TONIGHT SINCE
BOUNDARY LAYER MOISTURE IS VERY RICH BY DECEMBER STANDARDS...AND
JUST A FEW HOURS OF CLEAR SKIES AND CALM WINDS SHOULD YIELD
WIDESPREAD FOG. MUCH LIKE WE SAW LAST NIGHT THE FOG COULD BECOME
DENSE WITH VISIBILITIES DROPPING BELOW 1/4 MILE AT TIMES. GIVEN
UNCERTAINTIES IN THE TIMING AND LOCATION OF ANY DENSE FOG WE WILL
NOT ISSUE A DENSE FOG ADVISORY AT THIS TIME...BUT ONE MAY BE NEEDED
IN THE NEXT 4-6 HOURS.
VERY LITTLE CHANGES ARE NEEDED TO THE REMAINDER OF THE
FORECAST...WITH LOWS STILL EXPECTED TO FALL INTO THE UPPER 40S TO
AROUND 50.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY...HIGH PRESSURE ON TUESDAY WILL GIVE WAY TO A
QUICK MOVING FRONT ON WEDNESDAY NIGHT INTO EARLY THURSDAY MORNING.
THE BEST DYNAMICS WILL REMAIN NORTH OF VIRGINIA AND ISENTROPIC
FLOW SHOWS SOME UPWARD VERTICAL MOTION BUT IT IS NOT THAT
IMPRESSIVE IN THE LAYER`S AT BELOW 300 KELVIN. SO EXPECT SCATTERED
SHOWERS WITH LOW QPF VALUES.
MAXIMUM TEMPERATURES ARE EXPECTED TO REMAIN IN THE LOWER TO MID
70S FOR TUESDAY AND UPPER 60S ON WEDNESDAY. LOW TEMPERATURES ARE
EXPECTED TO BE IN THE MID 50S TUESDAY AND WITH THE COLD AIR
ADVECTION BEHIND THE FRONT TEMPERATURES SHOULD DROP INTO THE LOWER
TO MID 40S.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 3 PM MONDAY...MEDIUM RANGE GUIDANCE CONTINUES TO TREND
TOWARD A MILDER AND DRIER SCENARIO FOR THE EXTENDED. INITIALLY A
ZONAL FLOW ALOFT PREVAILS THEN A POTENT SHORTWAVE DIVES INTO THE
EASTERN SLOPES OF THE ROCKIES ALLOWING A SIGNIFICANT RIDGE TO
DEVELOP OFF OF THE SOUTHEAST COAST. CONTINUED TO TREND POPS DOWN
THROUGH THE PERIOD FOLLOWING HPC AS BERMUDA HIGH PRESSURE WILL BE
THE DOMINANT FEATURE FOR OUR AREA. SLIGHT CHANCE POPS REMAIN FOR
MONDAY FOR GENERAL CONVECTION OF ALL THINGS AS SOUNDINGS ARE
SHOWING CAPE VALUES NEAR 500 J/KG. TOUGH TO FIND FORCING OTHER
THAN MESOSCALE FEATURES SUCH AS THE SEA BREEZE AND DIFFERENTIAL
HEATING. SEA FOG REMAINS A POSSIBILITY WITH A QUICK CHECK OF
SURFACE DEWPOINTS IN THE MID TO UPPER 60S SUNDAY...AND RELATIVELY
LIGHT WINDS.
TEMPERATURES WILL BE A BIG STORY AS WELL AS POPS ARE OUT OF THE
FORECAST AND WITH 850MB TEMPERATURES SLIGHTLY WARMER THAN WE HAVE
CURRENTLY...A COUPLE OF DAYS IN THE 70S APPEARS TO BE A GOOD BET.
THESE WILL OCCUR SUNDAY AND MONDAY. LEADING UP TO THIS...MORE
SEASONAL VALUES CAN BE EXPECTED.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
AS OF 00Z...EXPECT MVFR/IFR DUE TO FOG LATE OVERNIGHT INTO TUESDAY
MORNING. OTHERWISE EXPECT VFR.
NEARLY CLEAR SKIES AND LIGHT WINDS ARE ALLOWING FOR AN IDEAL
RADIATIONAL COOLING SET UP FOR OVERNIGHT. LATEST TIME-HEIGHT
ANALYSIS AND FCST SOUNDINGS DEPICT THAT SUFFICIENT LOW LEVEL
MOISTURE IS SPREAD ACROSS MOST OF THE AREA DUE TO CONTINUED ONSHORE
FLOW. WITH THE ANTICIPATION OF CALM WINDS...EXPECT MVFR DUE TO
REDUCED VISIBILITIES...POSSIBLY JUST BEFORE MIDNIGHT. ANTICIPATE
CONDITIONS TO DETERIORATE LOWER TO IFR AND IN SOME AREAS LIFR DUE TO
FOG...WITH THE POTENTIAL FOR LOWERED CIGS AROUND 200FT.
RESTRICTIONS WILL LIKELY PERSIST AFTER DAYBREAK...WITH CONDITIONS
IMPROVING TO VFR BY LATE MORNING AND LASTING THROUGH THE REMAINDER
OF THE VALID PERIOD. EXPECT SOUTHWEST WINDS...BECOMING
SOUTH-SOUTHWEST WITH SUSTAINED WINDS AOB 8 KTS BY THE AFTERNOON
HOURS.
EXTENDED OUTLOOK...A SLIGHT CHANCE OF SHOWERS OVERNIGHT TUESDAY INTO
WEDNESDAY ASSOCIATED WITH A COLD FRONT. OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 930 PM MONDAY...NO FURTHER CHANGES ARE NEEDED TO WINDS OR
SEAS. PREVIOUS DISCUSSION FROM 630 AM FOLLOWS...
LIGHT SOUTH THROUGH WEST WINDS WILL CONTINUE THROUGH THE NIGHT AS
HIGH PRESSURE REMAINS JUST OFFSHORE. SEAS CONSIST ALMOST EXCLUSIVELY
OF A 9 SECOND SOUTHEAST SWELL...AVERAGING 2-3 FT. THE ONLY CHANGE TO
THE FORECAST IS TO RAISE AIR TEMPERATURE FORECASTS BY UP TO 5
DEGREES ACROSS THE OUTER PORTION OF THE COASTAL WATERS WITH THE MILD
SUBTROPICAL AIRMASS. PREVIOUS DISCUSSION FROM 300 PM FOLLOWS...
DESPITE WINDS BEING LESS THAN 10KT TODAY AND EVEN HAVING SOME
VARIABILITY IN DIRECTION THERE IS JUST ENOUGH SWELL ENERGY FOR A 3
FT WAVE OUT AT 41013 AND 41036. WNA AND SWAN SHOW THAT FOR THE MOST
PART THE 3 FT SEAS WILL LARGELY REMAIN OUTSIDE OF THE 20NM FORECAST
ZONES SAVE FOR ALONG FRYING PAN SHOALS..AND EVEN THAT MIGHT BE A
STRETCH. WILL ADVERTISE 2 FT FOR ALL BUT AMZ252 WHERE 2 TO 3 FT WILL
STILL BE ADVERTISED. EVE SHIFT MAY BE ABLE TO DROP 3 FT SEAS AFTER
MONITORING BUOY DATA.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY...WINDS WILL BE LIGHT AT 12 UTC ON TUESDAY AND AS
HIGH PRESSURE GIVES AWAY TO FRONTAL BOUNDARY THE WIND DIRECTION WILL
SWING TO THE SOUTHWEST AND INCREASE UP TO 10 KNOTS BY THE END OF THE
DAY. THE WINDS WILL CONTINUE TO VEER FROM THE SOUTHWEST TO NORTHEAST
AS THE FRONT MOVES ACROSS THE COASTAL WATERS. COLD AIR ADVECTION
WILL FOLLOW AND WINDS SPEED ARE EXPECTED TO INCREASE TO 20 TO 25
KNOTS FROM THE NORTHEAST LATE WEDNESDAY NIGHT. A SMALL CRAFT
ADVISORY MAY BE LIKELY IF THE MODELS CONSISTENCY CONTINUES.
LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 3 PM MONDAY...NORTHEAST WINDS INITIALLY FROM 15-20 KNOTS AS
HIGH PRESSURE BUILDS DOWN THE EAST COAST. SPEEDS WILL QUICKLY
DIMINISH TO LESS THAN TEN KNOTS BY FRIDAY MORNING. WILL PROBABLY
HAVE A MARGINAL SMALL CRAFT ADVISORY FOR SEAS AS WELL THURSDAY.
WIND SHIFT OCCURS LATE FRIDAY TO SOUTHEAST AS THE AFOREMENTIONED
HIGH QUICKLY MOVES OFFSHORE. SPEEDS WILL REMAIN LIGHT AND CONTINUE
THROUGH SATURDAY. SIGNIFICANT SEAS WILL DROP TO AROUND TWO FEET.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...TRA
SHORT TERM...DRH
LONG TERM...SHK
AVIATION...SGL
AREA FORECAST DISCUSSION
NWS RALEIGH NC
250 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/...
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 /18Z SUNDAY THROUGH FRIDAY/...
AS OF 130 PM SUNDAY...
VFR CIGS AND VSBYS WILL HOLD THROUGH MID EVENING WITH SURFACE HIGH
PRESSURE SPANNING THE AREA AND WARM/DRY AIR ALOFT. AN UPPER LEVEL
TROUGH PASSING BY QUICKLY TO OUR NORTH WILL EXIT THE COAST LATER
THIS AFTERNOON... TAKING THE HIGH CLOUDS WITH IT. DAYTIME SCATTERED
TO BROKEN STRATOCUMULUS WILL PERSIST THROUGH THE REST OF THE
AFTERNOON BEFORE DISSIPATING LATE. CLOUDS WILL REDEVELOP AFTER
SUNSET... WITH A WARM LOW LEVEL FLOW FROM THE SW. VERY LIGHT WINDS
AT FAY/RWI AND GREATER LOW LEVEL MOISTURE WILL RESULT IN IFR
CIGS/VSBYS DEVELOPING AFTER 07Z. AT RDU... IFR VSBYS ARE EXPECTED...
WHILE AT GSO/INT... VSBYS WILL TREND TO MVFR... DUE TO THE SLIGHTLY
STRONGER WINDS AT THESE THREE LOCATIONS FAVORING DEVELOPMENT OF
VFR-LEVEL STRATUS OVERNIGHT. VFR CONDITIONS WILL RETURN AT ALL SITES
AFTER 13Z AT INT/GSO/RDU... AND AFTER 15Z AT FAY/RWI.
LOOKING BEYOND 18Z MONDAY... MVFR/IFR FOG IS AGAIN POSSIBLE LATE
MONDAY NIGHT/TUESDAY MORNING... AND AGAIN LATE TUESDAY NIGHT. AN
APPROACHING COLD FRONT WILL BRING A CHANCE OF MVFR CIGS IN RAIN LATE
TUESDAY NIGHT INTO MID AFTERNOON WEDNESDAY. THE FRONT IS THEN
EXPECTED TO MOVE TO OUR SOUTH... BRINGING A RETURN TO VFR CONDITIONS
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT... THEN MVFR CIGS MAY
REDEVELOP ON FRIDAY AS THE FRONT MOVES BACK NORTHWARD AS A WARM
FRONT. -GIH
&&
.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...HARTFIELD
CLIMATE...WFO RAH
AREA FORECAST DISCUSSION
NWS RALEIGH NC
248 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/...
AS OF 300 AM SUNDAY...
TUESDAY...FORECAST AREA WILL BE BETWEEN AN AREA OF HIGH PRESSURE
CENTERED OFFSHORE OF THE SE U.S. AND A POSITIVE-TILT S/W CROSSING
THE GREAT LAKES/OH VALLEY. THIS WILL RESULT IN A DEEP SW FLOW OVER
CENTRAL NC. THIS SCENARIO IS SUPPORTIVE OF VERY WARM AND MAINLY DRY
CONDITIONS. EVEN THOUGH LOW LEVEL THICKNESSES LOWER INTO THE
1360S...PLENTY OF SUNSHINE AND STEADY SW FLOW SHOULD BOOST TEMPS
BACK INTO THE LOWER 70S.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 230 AM SUNDAY...
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT:
MODELS CONTINUE TO BE IN GOOD AGREEMENT ON THE TIMING AND STRENGTH
OF THE NEXT SYSTEM TO AFFECT THE AREA MIDWEEK. BEST FORCING APPEARS
TO CONTINUE TO BE LOCATED TO THE NORTH OF THE REGION... WHILE ANY
GOOD SURFACE INSTABILITY WILL REMAIN TO THE SOUTH OF THE AREA.
THUS... MODELS CONTINUE TO SHOW NOT MUCH IN THE WAY OF RAINFALL
AMOUNTS... ALTHOUGH MORE THAN YESTERDAY AT THIS TIME. THUS... WILL
CONTINUE TO GO WITH A LOW END CHANCE POPS FOR NOW FOR WEDNESDAY
MORNING INTO THE AFTERNOON. WRT THE TIMING OF THE COLD FRONT...
EXPECT THE FRONT TO MOVE INTO THE NORTHERN/NORTHWESTERN PIEDMONT BY
MID MORNING AND BE TO THE SOUTH/SOUTHEAST OF THE AREA BY 00Z
THURSDAY. HIGH TEMPS WILL BE TRICKY AND DEPENDENT ON HOW QUICKLY THE
FRONT ACTUALLY MOVES THROUGH THE AREA... ALONG WITH HOW QUICKLY
SKIES ARE ABLE TO CLEAR. FOR NOW WILL CONTINUE TO GO WITH HIGH TEMPS
RANGING FROM THE LOWER 60S NORTH TO THE MID TO UPPER 60S
SOUTH/SOUTHEAST. LOW TEMPS WEDNESDAY MORNING ARE EXPECTED TO BE
RATHER MILD FOR THIS TIME OF YEAR WITH EXPECT PARTLY TO MOSTLY
CLOUDY SKIES AND SOUTHWESTERLY LOW LEVEL FLOW. THUS... WILL GO WITH
LOWS IN THE LOWER TO MID 50S FOR WEDNESDAY MORNING.
EXPECT CLEARING SKIES WEDNESDAY EVENING AS THE FRONT SETTLES TO THE
SOUTH OF THE REGION AND HIGH PRESSURE BUILDS SOUTHWARD INTO THE
AREA. LOWS THURSDAY MORNING ARE EXPECTED TO BE MUCH COOLER AS DRIER
AND COLDER AIR FILTERS INTO THE REGION. WILL GO WITH LOWS THURSDAY
MORNING GENERALLY IN THE MID TO UPPER 30S.
THURSDAY THROUGH SATURDAY:
SURFACE HIGH PRESSURE WILL QUICKLY MOVE ACROSS THE REGION LATE
WEEK... WITH BRIEF WEAK S/W RIDGING MOVING ACROSS THE AREA (MOSTLY
ZONAL FLOW). THE NEXT DEVELOPING TROUGH AND ASSOCIATED COLD FRONT
WILL APPROACH THE REGION ON FRIDAY FROM THE WEST. HOWEVER... MODELS
CONTINUE TO STRUGGLE WITH THE EVOLUTION OF THIS TROUGH AND
ASSOCIATED COLD FRONT. THUS... CONFIDENCE IN THE FORECAST BY NEXT
WEEK IS RATHER LOW (LARGE SWINGS IN THE MODELS FROM RUN TO RUN ALONG
WITH MODEL DISCREPANCIES). HOWEVER... IT STILL APPEARS WE SHOULD SEE
A WARMING TREND BY FRIDAY... POTENTIALLY LASTING INTO SATURDAY
(MAYBE EVEN BEYOND). THUS... EXPECT HIGH TEMPS THURSDAY IN THE LOWER
TO MID 50S... WARMING TO THE 60S BY FRIDAY INTO SATURDAY (WITH MAYBE
EVEN SOME LOWER 70S ACROSS THE SOUTH BY SATURDAY... GIVEN THE LATEST
GUIDANCE HOLDS ANY FROPA AND ANY PRECIP TO THE WEST OF THE AREA NOW
ON SATURDAY. LOW TEMPS DURING THIS TIMEFRAME ARE EXPECTED TO BE IN
THE MID TO UPPER 30S FRIDAY MORNING TO LOWER TO MID 40S BY SATURDAY
MORNING.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
AS OF 130 PM SUNDAY...
VFR CIGS AND VSBYS WILL HOLD THROUGH MID EVENING WITH SURFACE HIGH
PRESSURE SPANNING THE AREA AND WARM/DRY AIR ALOFT. AN UPPER LEVEL
TROUGH PASSING BY QUICKLY TO OUR NORTH WILL EXIT THE COAST LATER
THIS AFTERNOON... TAKING THE HIGH CLOUDS WITH IT. DAYTIME SCATTERED
TO BROKEN STRATOCUMULUS WILL PERSIST THROUGH THE REST OF THE
AFTERNOON BEFORE DISSIPATING LATE. CLOUDS WILL REDEVELOP AFTER
SUNSET... WITH A WARM LOW LEVEL FLOW FROM THE SW. VERY LIGHT WINDS
AT FAY/RWI AND GREATER LOW LEVEL MOISTURE WILL RESULT IN IFR
CIGS/VSBYS DEVELOPING AFTER 07Z. AT RDU... IFR VSBYS ARE EXPECTED...
WHILE AT GSO/INT... VSBYS WILL TREND TO MVFR... DUE TO THE SLIGHTLY
STRONGER WINDS AT THESE THREE LOCATIONS FAVORING DEVELOPMENT OF
VFR-LEVEL STRATUS OVERNIGHT. VFR CONDITIONS WILL RETURN AT ALL SITES
AFTER 13Z AT INT/GSO/RDU... AND AFTER 15Z AT FAY/RWI.
LOOKING BEYOND 18Z MONDAY... MVFR/IFR FOG IS AGAIN POSSIBLE LATE
MONDAY NIGHT/TUESDAY MORNING... AND AGAIN LATE TUESDAY NIGHT. AN
APPROACHING COLD FRONT WILL BRING A CHANCE OF MVFR CIGS IN RAIN LATE
TUESDAY NIGHT INTO MID AFTERNOON WEDNESDAY. THE FRONT IS THEN
EXPECTED TO MOVE TO OUR SOUTH... BRINGING A RETURN TO VFR CONDITIONS
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT... THEN MVFR CIGS MAY
REDEVELOP ON FRIDAY AS THE FRONT MOVES BACK NORTHWARD AS A WARM
FRONT. -GIH
&&
.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.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...WSS
LONG TERM...BSD
AVIATION...HARTFIELD
CLIMATE...WFO RAH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1015 PM CST SAT DEC 1 2012
.DISCUSSION...
DENSE FOG HAS EXPANDED DURING THE LATE EVENING HOURS...PROMPTING A
DENSE FOG ADVISORY FOR MUCH OF THE FORECAST AREA EXCEPT FOR THE
FAR SOUTH. THE ENTIRE ADVISORY EXPIRES AT 9 AM CST SUNDAY...AND
LATER SHIFTS CAN ADJUST AS NEEDED.
&&
.AVIATION...
LOW STRATUS REDEVELOPING IN THE MISSOURI RIVER VALLEY IS PROMPTING
AMENDMENTS KEEP IFR/LIFR CONDITIONS IN LONGER OVERNIGHT AT
KBIS/KISN. THE LATEST RAP HAS A GOOD HANDLE ON THE LOW LEVEL
MOISTURE AND WILL GENERALLY FOLLOW ITS SLOWER CLEARING FOR THE
NEXT TAF ISSUANCE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 9 AM CST SUNDAY FOR NDZ001>005-009>013-
017>023-025-035>037.
&&
$$
DISCUSSION/AVIATION...RK
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
422 PM EST SUN DEC 2 2012
.SYNOPSIS...
A WEAK BOUNDARY NEAR THE AREA TONIGHT WILL PUSH NORTH OF THE
REGION ON MONDAY. A COLD FRONT WILL MOVE THROUGH THE AREA ON
TUESDAY. HIGH PRESSURE WILL BUILD INTO THE REGION FOR WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
MORE WIDESPREAD SHOWER ACTIVITY IS CURRENTLY LOCATED ACROSS SE
PORTIONS OF THE FA ACROSS NORTHERN KENTUCKY. ELSEWHERE ACROSS THE
FA...SOME LIGHT SHOWER AND IN SOME INSTANCES DRIZZLE ACTIVITY IS
OCCURRING. WITH ISENTROPIC LIFT ACROSS A LARGE PORTION OF THE AREA
THROUGH THE OVERNIGHT HOURS HAVE KEPT PRECIPITATION CHANCES IN THE
FORECAST FOR THE FA. SOUTHERN PORTIONS OF THE FA ARE MORE LIKELY
TO SEE SHOWER TYPE ACTIVITY WHILE NORTHERN PORTIONS OF THE FA ARE
MORE LIKELY TO SEE DRIZZLE DURING THE OVERNIGHT HOURS. IN
ADDITION...VISIBILITIES WILL BE REDUCED TONIGHT WITH SOME FOG.
HAVE FOG IN THE FORECAST ACROSS NORTHERN PORTIONS OF THE FA WHERE
VISIBILITIES WILL BE REDUCED THE MOST.
TEMPERATURES WILL DROP VERY LITTLE ACROSS THE FA THROUGH THE
OVERNIGHT HOURS. TEMPERATURES ARE CURRENTLY IN THE 50S AND EXPECT LOW
TEMPERATURES ONLY TO BE IN THE LOW 50S ACROSS MOST OF THE AREA
OVERNIGHT.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
SHOWER ACTIVITY WILL LIFT TO THE NORTH ON MONDAY AND PRECIPITATION
CHANCES WILL BEGIN TO COME TO AN END BY THE MIDDLE OF THE DAY.
CLOUD COVER WILL ALSO DECREASE ACROSS THE AREA AND WITH DECENT
SOUTHERLY FLOW TEMPERATURES WILL RISE INTO THE MIDDLE 60S TO
AROUND 70 DEGREES.
CLOUD COVER WILL BEGIN TO INCREASE ACROSS THE AREA MONDAY NIGHT AS
A COLD FRONT APPROACHES THE AREA. PRECIPITATION WILL HOLD OFF
UNTIL AFTER MIDNIGHT MONDAY NIGHT HOWEVER RAIN SHOWERS WILL BEGIN
TO MOVE INTO NW PORTIONS OF THE FA BY MORNING. RAIN SHOWERS WILL
OVERSPREAD THE FA DURING THE DAY ON TUESDAY. A LITTLE BIT OF WEAK
INSTABILITY CAN BE FOUND ACROSS SE PORTIONS OF THE FA ON TUESDAY
AFTERNOON AND THEREFORE ADDED A SLIGHT CHANCE OF THUNDER INTO THE
FORECAST ACROSS THAT AREA FOR A FEW HOURS. THE COLD FRONT WILL
MOVE THROUGH THE FA DURING THE AFTERNOON AND INTO THE EVENING
HOURS ON TUESDAY. PRECIPITATION WILL TAPER OFF TUESDAY EVENING AND
INTO TUESDAY NIGHT. COOLER AIR WILL FILTER INTO THE AREA TUESDAY
NIGHT WITH LOWS DROPPING DOWN INTO THE LOW TO MIDDLE 30S BY
WEDNESDAY MORNING.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
HIGH PRESSURE WILL BUILD INTO THE REGION ON WEDNESDAY DROPPING
TEMPERATURES CLOSER TO SEASONAL AVERAGE. BUT THIS WILL BE
SHORT-LIVED AS THE HIGH MOVES OFF TO THE EAST THURSDAY AND
TEMPERATURES REBOUND.
A FRONT WILL DROP INTO THE REGION ON FRIDAY AND BECOME
QUASI-STATIONARY THROUGH THE WEEKEND. WHILE THERE ARE MODEL
DIFFERENCES ON EXACTLY WHERE THIS BOUNDARY WILL SET UP...IT DOES
BRING THE POTENTIAL FOR UNSETTLED CONDITIONS THROUGH THE END OF THE
PERIOD...ESPECIALLY AS WAVES OF LOW PRESSURE TRAVEL ALONG THE
STALLED FRONT. AT THIS POINT HIGHER CONFIDENCE IN WET CONDITIONS IS
FOR FRIDAY AFTERNOON INTO FRIDAY NIGHT PARTICULARLY IN SOUTHERN
ZONES. NOT OUT OF THE QUESTION THAT THERE COULD BE SOME LIGHT SNOW
MIXED IN AT TIMES OVER THE WEEKEND IN THE FAR NORTH. BUT THAT IS ALL
DEPENDENT ON STRENGTH AND LOCATION OF THE BOUNDARY.
&&
.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
MORE WIDESPREAD PCPN ASSOCIATED WITH A WEAK BOUNDARY HAS PUSHED
SOUTH AND EAST OF THE TAF SITES EARLY THIS AFTERNOON. MVFR TO
OCCASIONALLY IFR CIGS HAVE PUSHED DOWN BEHIND THE BOUNDARY AND WILL
LIKELY REMAIN IN PLACE THROUGH MUCH OF THE TAF PERIOD. IN
FACT...BOTH THE NAM AND LATEST SEVERAL RUNS OF THE RAP ARE
KEEPING THINGS PRETTY MUCH SOCKED IN THROUGH AT LEAST TONIGHT.
WILL THEREFORE KEEP THE TAFS PRETTY PESSIMISTIC WITH PREVAILING
IFR CONDITIONS BY TONIGHT. THE BOUNDARY WILL STALL OUT TO OUR
SOUTH THIS EVENING AND THEN BEGIN TO LIFT BACK TO THE NORTH. THIS
COULD RESULT IN SOME LINGERING SHOWER ACTIVITY...ESPECIALLY AT THE
SOUTHERN TAF SITES THROUGH TONIGHT. AS THE BOUNDARY BEGINS TO LIFT
NORTH...EXPECT IMPROVING CONDITIONS FROM THE SOUTH TOWARD THE END
OF THE TAF PERIOD.
OUTLOOK...MVFR CEILINGS AND VISIBILITIES ARE POSSIBLE TUESDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...NOVAK
NEAR TERM...NOVAK
SHORT TERM...NOVAK
LONG TERM...
AVIATION...JGL
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1259 PM EST SUN DEC 2 2012
.SYNOPSIS...
A WEAK FRONT DROPPING INTO OHIO WILL BRING SCATTERED SHOWERS
TODAY INTO TONIGHT. THE FRONT WILL LIFT BACK NORTH ON MONDAY...WITH
UNSEASONABLY WARM TEMPERATURES CONTINUING. A STRONGER COLD FRONT
WILL MOVE THROUGH ON TUESDAY OFFERING WIDESPREAD SHOWERS AND COOLER
TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SHORTWAVE ENERGY PROGRESSING EAST ACROSS OUR AREA THIS MORNING
WITH LEADING EDGE OF PCPN RIGHT ALONG INTERSTATE 71. THIS LINES UP
WITH THE AREA OF BEST LOW LEVEL CONVERGENCE THAT WILL LAY OUT
ALONG THE OHIO RIVER HEADING INTO THIS AFTERNOON. WILL THEREFORE
ALLOW FOR HIGH POPS TO PROGRESS EAST OVER THE NEXT COUPLE OF
HOURS...WITH BEST CHANCE THEN LINING UP ACROSS OUR SOUTH THROUGH
THIS AFTERNOON. WEAK ELEVATED INSTABILITIES WILL ALSO PERSIST INTO
THIS AFTERNOON SO WILL LIKELY CONTINUE TO SEE SOME ISOLATED
LIGHTNING STRIKES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
WITH THE PASSAGE OF MID LEVEL SHORTWAVE THE FLOW WILL AMPLIFY WITH
RIDGING BUILDING OVER THE GREAT LAKES/OH VLY ON TONIGHT INTO
MONDAY. SFC FRONTAL BOUNDARY TO STALL OUT E-W TONIGHT ACRS SRN
OHIO AND THEN RETURN NORTH ON MONDAY. WILL DIMINISH POPS TONIGHT
WITH THE LOSS OF UPPER SUPPORT. MILD TEMPERATURES TO CONTINUE WITH
TONIGHTS LOWS ABOVE NORMAL HIGHS...RANGING FROM NEAR 50 NORTH TO
THE MID 50S SOUTH.
ON MONDAY WILL LIMIT MENTION OF SHOWERS TO SLIGHT CHC EARLY AND
PIVOT THESE POPS NORTH OUT OF ILNS FA AS THE FRONT LIFTS NORTH AND
THE MID/UPR LEVEL RIDGE BUILDS. WARM TEMPS TO CONTINUE WITH
MONDAYS HIGHS AROUND 20 DEGREES ABOVE NORMAL...RANGING FROM THE
MID 60S NORTH TO 70 SOUTH.
UPPER LEVEL TROF TO TRANSLATE EAST ACRS THE NATIONS MID SECTION
AND ASSOCIATED SFC FRONT TO SWEEP EAST ACRS ILNS FA TUESDAY AFTERNOON.
WILL INTRODUCE CHANCE POPS INTO THE WEST LATE MONDAY NIGHT AND
THEN RAMP UP TO CATEGORICAL WITH FROPA ON TUESDAY. MILD TEMPS TO
CONTINUE MONDAY NIGHT WITH LOWS IN THE LOWER/MIDDLE 50S. TUESDAY
WILL BE A TRANSITION DAY WITH HIGHS RANGING FROM THE UPPER 50S NW
TO THE UPPER 60S SE.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
SHOWERS WILL ACCOMPANY A COLD FRONT THAT WILL MOVE ACROSS THE REGION
TUESDAY AFTERNOON AND EVENING. HIGH PRESSURE WILL BUILD IN WEDNESDAY
AND MOVE OFF TO THE EAST ON THURSDAY. FAIRLY GOOD MODEL AGREEMENT
THAT LOW PRESSURE WILL DEVELOP IN THE OZARKS THURSDAY NIGHT AND MOVE
UP THE OHIO VALLEY FRIDAY AND FRIDAY NIGHT. THIS WILL BRING RAIN TO
THE REGION. HIGH PRESSURE WILL BUILD BACK IN FROM THE NORTHWEST ON
SATURDAY. TEMPERATURES WILL BE AT OR ABOVE NORMAL THROUGH THE
PERIOD.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
MORE WIDESPREAD PCPN ASSOCIATED WITH A WEAK BOUNDARY HAS PUSHED
SOUTH AND EAST OF THE TAF SITES EARLY THIS AFTERNOON. MVFR TO
OCCASIONALLY IFR CIGS HAVE PUSHED DOWN BEHIND THE BOUNDARY AND WILL
LIKELY REMAIN IN PLACE THROUGH MUCH OF THE TAF PERIOD. IN
FACT...BOTH THE NAM AND LATEST SEVERAL RUNS OF THE RAP ARE
KEEPING THINGS PRETTY MUCH SOCKED IN THROUGH AT LEAST TONIGHT.
WILL THEREFORE KEEP THE TAFS PRETTY PESSIMISTIC WITH PREVAILING
IFR CONDITIONS BY TONIGHT. THE BOUNDARY WILL STALL OUT TO OUR
SOUTH THIS EVENING AND THEN BEGIN TO LIFT BACK TO THE NORTH. THIS
COULD RESULT IN SOME LINGERING SHOWER ACTIVITY...ESPECIALLY AT THE
SOUTHERN TAF SITES THROUGH TONIGHT. AS THE BOUNDARY BEGINS TO LIFT
NORTH...EXPECT IMPROVING CONDITIONS FROM THE SOUTH TOWARD THE END
OF THE TAF PERIOD.
OUTLOOK...MVFR CEILINGS AND VISIBILITIES ARE POSSIBLE TUESDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...AR
NEAR TERM...JGL
SHORT TERM...AR
LONG TERM...
AVIATION...JGL
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
337 AM EST SUN DEC 2 2012
.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE ACROSS THE UPPER GREAT LAKES
TODAY AND DRAG A WEAK COLD FRONT ACROSS THE LOCAL AREA. A WARM
FRONT WILL LIFT NORTH ACROSS THE AREA ON MONDAY AND WILL BE
FOLLOWED BY A STRONGER COLD FRONT ON TUESDAY. HIGH PRESSURE IS
EXPECTED TO BUILD OVER THE OHIO VALLEY FOR THE MIDDLE PORTION OF
THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AN AREA OF SHOWERS CONTINUES TO MOVE MOVE ENE ACROSS THE AREA THIS
MORNING. MOST OF THIS PRECIP IS OVER LAKE ERIE. MODELS CONTINUE TO
SHOW MORE PRECIP DEVELOPING THIS MORNING OVER NW OH AND MOVING
ACROSS THE REMAINDER OF THE AREA TODAY. THIS PRECIP WILL BE
ASSOCIATED WITH A FRONTAL BOUNDARY. EXPECT DEWPOINTS TO SURGE TO
CLOSE TO 50 DEGREES TODAY. THIS COULD BE ENOUGH FOR SOME EMBEDDED
THUNDER IN THE STRONGER SHOWERS. WILL CONTINUE WITH HIGH POPS ALL
AREAS. THE FRONT AND MOST OF THE PRECIP SHOULD BE EAST OF THE AREA
BY SUNSET. PLACES LIKE KTOL AND KFDY WILL LIKELY BE DRY AFTER 18Z.
850 MB TEMPS WILL SURGE TO AROUND PLUS 8 TODAY. THIS MEANS EVEN
WITH CLOUDS AND RAIN...TEMPS SHOULD BE A DEGREE OR TWO WARMER
THAN SATURDAY MOST AREAS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
THERE COULD BE SOME LINGERING SHOWERS IN THE EAST EARLY TONIGHT. A
WARM FRONT IS EXPECTED TO DEVELOP AND LIFT NORTH ACROSS THE AREA
ON MONDAY. EXPECT SOME VIRGA AND PERHAPS SOME LIGHT PRECIP WITH
THIS FRONT AND WILL CONTINUE WITH A SMALL MENTION IN THE FORECAST.
BETTER CHANCES FOR SHOWERS WILL COME MONDAY NIGHT AND TUESDAY AS A
STRONGER COLD FRONT RACES EAST ACROSS THE REGION. THE MODELS HAVE
BEEN FAIRLY CONSISTENT WITH THIS FEATURE AND HAVE MADE ONLY MINOR
ADJUSTMENTS TO THE FORECAST. DEWPOINTS WILL AGAIN GET INTO THE
LOWER 50S SO LATER SHIFTS MADE EVENTUALLY NEED TO ADD THUNDER.
DRIER AND COLDER AIR WILL MOVE INTO THE REGION BEHIND THE FRONT ON
TUESDAY NINTH AND WEDNESDAY. A SURFACE RIDGE WILL BE OVERHEAD BY
WEDNESDAY NIGHT. THERE WILL BE A SMALL WINDOW FOR SOME LAKE EFFECT
SHOWERS TUESDAY NIGHT INTO WEDNESDAY EAST OF CLEVELAND. BUT...BY
EARLY WEDNESDAY AFTERNOON THE SETUP BECOMES PRETTY UNFAVORABLE
WITH AN EASTERLY COMPONENT TO THE WIND. CRITICAL THICKNESSES
SUGGEST IT WILL BE COLD ENOUGH FOR AT LEAST MIXED PRECIP. NOT MUCH
IF ANY ACCUMULATION IS EXPECTED. WILL TRY FOR DRY WEATHER ON
WEDNESDAY NIGHT.
HAVE NOT CHANGED THE PREVIOUS TEMP FORECAST MUCH. JUST SOME MINOR
ADJUSTMENTS HERE AND THERE.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
LITTLE CHANGE WITH THE END OF THE WEEK. THURSDAY HIGH PRESSURE
SHIFTS EAST. A COLD FRONT WILL BE MAKING ITS WAY ACROSS THE EASTERN
GREAT LAKES LATER FRIDAY...BUT THEN STALLS ACROSS THE OHIO VALLEY
FOR SATURDAY. THESE LARGE SCALE FEATURES ARE FAIRLY WELL AGREED
UPON...BUT DIFFERENCES REMAIN AS EXPECTED WITH THE DETAILS. THE
TIMING AND THE SOUTHERN EXTENT OF THE FRONT WILL DETERMINE OUR LOW
TEMPERATURES ON FRIDAY NIGHT AND THEN ALSO HIGHS ON SATURDAY
DEPENDING ON WHERE THE FRONT IS WHEN A STRONGER WAVE DEVELOPS ON THE
FRONT. HOW MUCH COLD AIR WILL IT DRAW IN ON THE NORTH SIDE WILL BE
THE QUESTION. RIGHT NOW SEASONABLE THURSDAY INTO FRIDAY. WILL BRING
A CHANCE OF RAIN SHOWERS IN FRIDAY...BUT WILL MENTION BOTH RAIN AND
SNOW SHOWERS FOR FRIDAY NIGHT AND SATURDAY AS WE SLOWLY GET COLDER.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
THE LOW LEVEL JET IS ON THE INCREASE AHEAD OF A WEAKENING COLD FRONT
OVERNIGHT. THE SHOWERS ARE BEGINNING TO DEVELOP. THE HRRR MODEL
IS NOW DEVELOPING THE SHOWERS A LITTLE SLOWER. WE WILL HAVE SOME
SCATTERED SHOWERS AHEAD OF THE MAIN BAND OF SHOWERS. AT THIS TIME
NO MENTION OF THUNDER BUT ISOLATED THUNDERSTORMS ARE POSSIBLE LATE
TONIGHT THROUGH MID AFTERNOON ON SUNDAY.
WINDS WILL BE ON THE INCREASE OVERNIGHT AND THAT SHOULD HELP PREVENT
LLWS.
MAINLY VFR OVERNIGHT AND THEN SLOWLY DECREASING THE CEILINGS TO
IFR ESPECIALLY FOR LATE SUNDAY MORNING AND AFTERNOON...MODERATELY
CONFIDENT IN THAT. CONDITIONS WILL STAY IFR ESPECIALLY SOUTH OF
THE LAKE SUNDAY EVENING.
OUTLOOK...NON VFR LIKELY LATE SUNDAY NIGHT THROUGH TUESDAY.
&&
.MARINE...
GRADIENT FAIRLY TIGHT AHEAD OF A COLD FRONT SCHEDULED TO COME ACROSS
THE LAKE TODAY SO WILL CONTINUE TO SEE A STIFF SOUTHWEST FLOW TO
START OFF THE DAY DECREASING SLOWLY BY LATER THIS AFTERNOON. WILL
KEEP THE SMALL CRAFT ADVISORY SET UP AS IS. HIGH PRESSURE BRIEFLY IN
PLACE TONIGHT THEN ANOTHER WARM FRONT LIFTS NORTH MONDAY. SO WINDS
WILL CALM WITH THE HIGH AND THEN BE OUT OF THE SOUTH AGAIN FOR
MONDAY. MONDAY NIGHT WILL BE A REPEAT OF CURRENT CONDITIONS AND WILL
SEE SOUTHWEST WINDS PICK UP AGAIN AHEAD OF A COLD FRONT FOR TUESDAY.
COULD SEE A SMALL CRAFT ADVISORY AGAIN. THE HIGH MOVES ACROSS THE
GREAT LAKES WEDNESDAY...STAYING NORTH OF THE LAKE AND MAINTAINING A
NORTHERLY COMPONENT FLOW. WILL BE ON THE BACKSIDE OF THE HIGH FOR
THURSDAY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR
LEZ147>149.
SMALL CRAFT ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR
LEZ142>146.
&&
$$
SYNOPSIS...KUBINA
NEAR TERM...KUBINA
SHORT TERM...KUBINA
LONG TERM...OUDEMAN
AVIATION...KIELTYKA
MARINE...OUDEMAN
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1147 PM EST SAT DEC 1 2012
.SYNOPSIS...
SHOWERS WILL DEVELOP ON SUNDAY AS A LOW PRESSURE SYSTEM TRACKS
ACROSS THE UPPER GREAT LAKES. ANOTHER WARM FRONT WILL LIFT NORTH
ACROSS THE AREA ON MONDAY WITH WELL ABOVE NORMAL TEMPERATURES. A
COLD FRONT WILL ARRIVE ON TUESDAY WITH A STRONGER COLD FRONT EARLY
WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
CONTINUING TO WATCH REGIONAL RADAR WITH SHOWERS DEVELOPING OFF TO
THE WEST EARLY TONIGHT. LITTLE CHANGE WITH RECENT MODEL RUNS ON
EXPECTATIONS FOR SHOWERS TO BUILD INTO THE AREA LATE TONIGHT
THROUGH SUNDAY MORNING. MADE SOME SMALL ADJUSTMENTS TO POPS
BETWEEN 06-12Z ACROSS THE AREA...BUT OTHERWISE CONTINUED WITH THE
THUNDER ACROSS THE WEST. TEMP TRENDS CONTINUE TO LOOK REASONABLE
ALSO.
PREVIOUS DISCUSSION...WATER VAPOR IMAGERY SHOWS A PLUME OF MOISTURE
ADVANCING TOWARDS THE REGION AHEAD OF A SERIES OF SHORTWAVES
MOVING THROUGH THE UPPER LEVEL FLOW. 12Z RAOBS SHOWED 850MB
DEWPOINTS AS HIGH AS 8C NOSING UP THE MISSISSIPPI VALLEY WHICH
WILL ADVANCE TO NW OHIO BY 12Z. THE ASSOCIATED SURFACE TROUGH
APPROACHING MINNESOTA WILL SLIDE NORTHEAST ACROSS THE UPPER GREAT
LAKES...MAINTAINING SOUTHERLY WINDS IN OUR FORECAST AREA
OVERNIGHT. ALTHOUGH UPSTREAM RADARS SHOW A LACK OF PRECIPITATION
AT THIS TIME...A LOW LEVEL JET WILL DEVELOP AHEAD OF THE TROUGH
AND LIFT ACROSS LOWER MICHIGAN TOWARDS THE EASTERN GREAT
LAKES...ENHANCING MOISTURE CONVERGENCE AND LEADING TO SHOWERS
DEVELOPING ACROSS NW OHIO. MODEL SOUNDINGS MOISTEN UP AT TOL
BETWEEN 6-9Z SPREADING EAST TOWARDS CLE BY AROUND 12Z. SOUNDINGS
ALSO REFLECT SOME MINOR ELEVATED INSTABILITY WHICH COULD SUPPORT
ISOLATED THUNDERSTORMS ACROSS NW OHIO OVERNIGHT. POPS TONIGHT WILL
RANGE FROM AROUND 80 PERCENT AT TOL TO AROUND 30 PERCENT AT CAK.
GIVEN THE INCREASING CLOUD COVER AND SOUTHERLY WINDS NEAR 10
MPH... TEMPERATURES WILL BE MILD FOR EARLY DECEMBER RANGING FROM
MID 40S IN NW PA TO THE LOW 50S IN NW OHIO.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY NIGHT/...
RAIN WILL SPREAD EAST ACROSS THE AREA ON SUNDAY AS SHORTWAVE ENERGY
SLIDES ACROSS THE GREAT LAKES REGION AND THE SURFACE LOW MOVES FROM
NORTHERN LAKE HURON INTO QUEBEC. A PERIOD OF SHOWERS ARE EXPECTED AT
ALL AREAS EVEN THOUGH QPF WILL BE LIGHT...GENERALLY LESS THAN .20
INCH. HAVE SLIGHTLY SPED UP THE TIMING WITH SHOWERS ENDING IN THE
TOL AREA BY LATE MORNING. WINDS WILL SHIFT AROUND TO THE SOUTHWEST
AS THE TROUGH PASSES BUT THE ACTUAL FRONT WILL STALL OVER LAKE ERIE
ON SUNDAY NIGHT WITH NO APPRECIABLE COLD ADVECTION. MID LEVELS DRY
OUT QUICKLY LATE IN THE DAY ON SUNDAY BUT PLENTY OF LOW LEVEL
MOISTURE WILL REMAIN WITH DEWPOINTS HOVERING NEAR 50 DEGREES.
MAV/MET GUIDANCE HIGHLIGHTING LOW CEILINGS AND WITH BACKING LOW
LEVEL FLOW HAVE ADDED A CHANCE OF DRIZZLE TO THE FORECAST.
TEMPERATURES WILL BE MILD AGAIN IN THE UPPER 40S/LOW 50S.
THE STALLED FRONTAL BOUNDARY WILL LIFT NORTH ON MONDAY AS THE UPPER
LEVEL RIDGE BUILDS AND SOUTHWESTERLY FLOW INCREASES AGAIN. THERE IS
SOME UNCERTAINTY IN HOW FAST WE WILL BE ABLE TO SCOUR OUT THE LOW
LEVEL MOISTURE...BUT EXPECTING CLOUDS TO START TO LIFT NORTH AND
POSSIBLY SCATTER OUT ACROSS CENTRAL OHIO...WITH SOME SUN SOUTH OF
A TOL/CAK LINE. AS LONG AS WE CAN GET SOME BREAKS IN THE
CLOUDS...TEMPERATURES SHOULD MAKE A RUN AT THE LOW TO MID 60S.
RECORDS ARE STILL SEVERAL DEGREES HIGHER FOR DECEMBER 3RD...RANGING
FROM THE UPPER 60S TO MID 70S SO WE WILL LIKELY NOT BE ABLE TO
BREAK ANY UNLESS WE END UP WITH FULL SUN ALL DAY.
THE NEXT COLD FRONT WILL PUSH SOUTH ACROSS THE AREA ON TUESDAY WITH
RAIN ACCOMPANYING THE FRONT. A SECONDARY COLD FRONT WILL ARRIVE
LATE TUESDAY NIGHT WITH STRONGER COLD ADVECTION CONTINUING INTO
WEDNESDAY.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
JUST COLD ENOUGH FOR SOME SNOW FLURRIES/SNOW SHOWERS ON WEDNESDAY IN
THE SNOWBELT OTHERWISE HIGH PRESSURE WILL BUILD IN WEDNESDAY AND
THURSDAY WITH SEASONABLE TEMPERATURES.
THE NEXT COLD FRONT STILL SEEMS ON TRACK FOR FRIDAY. THERE IS A
HINT THAT A WEAK WAVE COULD TRY TO FORM ON THE FRONT SOMEWHERE
BETWEEN THE GREAT LAKES AND TENNESSEE VALLEY SO NOT REAL CONFIDENT
ON THE TIMING AND THEREFORE DID NOT GO REAL HIGH ON THE PROBABILITY
OF PRECIPITATION ANY OF THE FORECAST PERIODS. ULTIMATELY WE WILL
NEED AT LEAST A LIKELY POP AT SOME POINT LATE IN THE WEEK. IF A WAVE
DOES DEVELOP...IT MAY GET COLD ENOUGH FOR A CHANGE TO SNOW ON THE
BACK END BUT WILL KEEP IT SIMPLE FOR NOW AND CALL FOR RAIN SHOWERS
FRIDAY THEN RAIN AND SNOW SHOWERS FRIDAY NIGHT...AND A SMALL CHANCE
OF LINGERING SNOW SHOWERS ON SATURDAY.
THE AIR MASS SHOULD BE RELATIVELY WARM ON FRIDAY BUT WILL NOT GO TOO
HIGH ON THE FORECAST HIGHS...40S...CONSIDERING THAT THE RAIN WILL
PROBABLY DEVELOP ON FRIDAY WHICH WOULD SUPPRESS THE TEMPS. BACK TO
SEASONABLE TEMPS ON SATURDAY.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
THE LOW LEVEL JET IS ON THE INCREASE AHEAD OF A WEAKENING COLD FRONT
OVERNIGHT. THE SHOWERS ARE BEGINNING TO DEVELOP. THE HRRR MODEL
IS NOW DEVELOPING THE SHOWERS A LITTLE SLOWER. WE WILL HAVE SOME
SCATTERED SHOWERS AHEAD OF THE MAIN BAND OF SHOWERS. AT THIS TIME
NO MENTION OF THUNDER BUT ISOLATED THUNDERSTORMS ARE POSSIBLE LATE
TONIGHT THROUGH MID AFTERNOON ON SUNDAY.
WINDS WILL BE ON THE INCREASE OVERNIGHT AND THAT SHOULD HELP PREVENT
LLWS.
MAINLY VFR OVERNIGHT AND THEN SLOWLY DECREASING THE CEILINGS TO
IFR ESPECIALLY FOR LATE SUNDAY MORNING AND AFTERNOON...MODERATELY
CONFIDENT IN THAT. CONDITIONS WILL STAY IFR ESPECIALLY SOUTH OF
THE LAKE SUNDAY EVENING.
OUTLOOK...NON VFR LIKELY LATE SUNDAY NIGHT THROUGH TUESDAY.
&&
.MARINE...
EVEN THOUGH THE LAKE AND 850 MB TEMPERATURE DIFFERENCE IS SMALL
THE SUSTAINED WINDS WILL BE STRONG ENOUGH TO MEET SMALL CRAFT
ADVISORY CRITERIA...AN ADVISORY HAS BEEN ISSUED. WILL HAVE TO
MONITOR THE WATER LEVEL ON THE WEST END OF THE LAKE ON SUNDAY AS
THE WATER LEVEL COULD APPROACH THE CRITICAL MARK FOR SAFE
NAVIGATION BUT IT IS NOT EXPECTED TO REACH IT.
PREVIOUS DISCUSSION...
THE WARM FRONT OVER LAKE ERIE HAS BEEN SLOW TO LIFT NORTH BUT IT
SHOULD MOVE NORTH OF THE LAKE EARLY TONIGHT WITH AN INCREASING SOUTH
WIND. WINDS ON THE OPEN WATERS MAY APPROACH 30 KNOTS LATE TONIGHT
AND SUNDAY MORNING WITH THE HIGHEST WAVES OBVIOUSLY ON THE CANADIAN
SIDE OF THE LAKE BUT THE LAKE WILL GET STIRRED UP ENOUGH TO WARRANT
A SMALL CRAFT ADVISORY FOR LATER TONIGHT AND SUNDAY.
THE GRADIENT WILL WEAKEN ENOUGH FOR THE WIND TO COME DOWN LATER
SUNDAY/SUNDAY NIGHT...THEN THE SOUTH TO SOUTHWEST WIND WILL GET
REESTABLISHED AND INCREASE AGAIN ON MONDAY AND MONDAY NIGHT AHEAD OF
A COLD FRONT ON TUESDAY. THE NORTHWEST FLOW FOLLOWING THE COLD FRONT
WILL REMAIN RATHER BRISK WEDNESDAY BEFORE HIGH PRESSURE MOVES OVER
THE LAKE AND CALMS THINGS DOWN ON THURSDAY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST SUNDAY FOR LEZ147>149.
SMALL CRAFT ADVISORY UNTIL 3 PM EST SUNDAY FOR LEZ142>146.
&&
$$
SYNOPSIS...KEC
NEAR TERM...ABE/KEC
SHORT TERM...KEC
LONG TERM...KOSARIK
AVIATION...KIELTYKA
MARINE...KIELTYKA/KOSARIK
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1043 AM EST SUN DEC 2 2012
.SYNOPSIS...
A WARM FRONT WEDGED ALONG THE EAST-SIDE OF THE ALLEGHENIES WILL
LIFT NORTHEAST THROUGH NEW ENGLAND TODAY...AHEAD OF A WEAK FRONTAL
SYSTEM PUSHING OUT OF THE GREAT LAKES. THE FRONTAL SYSTEM WILL BE
ACCOMPANIED BY A BAND OF RAIN AS IT MOVES THROUGH THE REGION THIS
EVENING. ABOVE NORMAL TEMPERATURES WILL PERSIST THROUGH EARLY NEXT
WEEK BEFORE A COLD FRONT PASSES TUESDAY NIGHT AND BRINGS MORE
SHOWERS AND A RETURN TO MORE SEASONAL TEMPERATURES FOR THE MIDDLE
OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
9AM UPDATE...
THE FOG ADVISORY HAS BEEN ALLOWED TO EXPIRE AS MOST REPORTING
SITES ARE NOW A MILE OR MORE.
ELSEWHERE SHOWERS CONTINUE TO PROGRESS SLOWLY OUT OF THE NW
MOUNTAINS. HRRR SUGGESTS THE RAIN MAKES ITS BIG PUSH INTO THE
CENTRAL PART OF THE STATE AFTER ABOUT MID DAY...BUT OVERALL QPF
SHOULD STILL REMAIN MOSTLY ON THE LIGHT SIDE. IT`S BEEN VERY DRY
SO ANY RAIN WILL BE WELCOME.
VERY MILD AIR HAS SURGED UP WEST OF THE ALLEGHENIES...BUT WHILE WE
REMAIN COOL AIR DAMMED...TEMPS ARE STILL MILD FOR THE TIME OF
YEAR AND WILL CONTINUE AS SUCH INTO THE NEW WORKWEEK.
&&
.SHORT TERM / MONDAY THROUGH 6 AM MONDAY/...
WARM FRONT WEDGED ALONG THE EAST-SIDE OF THE ALLEGHENIES WILL
LIFT NWD TDY...ALLOWING A SW FLOW OF UNSEASONABLY MILD AIR TO
OVERSPREAD THE ENTIRE AREA. AREAS OF FOG AND LOW STRATUS IN THE
CNTRL AND EASTERN ZONES WILL GRADUALLY IMPROVE/LIFT THRU LATE
MORNING.
A FAST MOVING LOW-AMPLITUDE SHORTWAVE TROUGH OF PACIFIC ORIGIN WILL
MOVE FROM THE GREAT LAKES/OH VALLEY INTO THE NERN STATES BY EVENING.
STG SWLY LOW LEVEL JET AHEAD OF ITS ASSOC FRONT WILL TRANSPORT ABV
NORMAL PWATS ENEWD ACROSS THE UPPER OH VALLEY INTO CENTRAL PA BY
THIS AFTN. THIS WILL SUPPORT HI POPS WITH LGT TO MOD PCPN TOTALS
EXPECTED. QPF AMTS WILL DROP OFF FROM NW TO SE...AS AREAS EAST OF
THE ALLEGHENY FRONT NEVER SEEM TO DO WELL IN TERMS OF QPF WITH SWLY
LLVL FLOW DUE TO COMBO OF DOWNSLOPE AND LACK OF LLVL CONVERGENCE.
THE BEST MID-UPPER FORCING STAYS TO THE NORTH SO AGAIN NOT LOOKING
AT ANY SIGNIFICANT PCPN WITH THIS RATHER WEAK FRONTAL SYSTEM.
DESPITE EXTENSIVE CLOUD COVER...THE UNSEASONABLY MILD SWLY FLOW
WILL ALLOW TEMPS TO CLIMB 5-10F ABOVE EARLY DECEMBER CLIMATE
NORMALS. MAX TEMPS WILL RANGE FROM NR 60F IN THE VALLEYS OF SW AND
SC PA...TO AROUND 50F OVR THE HIGH TERRAIN NORTH OF IPT WHERE THE
WARM FRONT WILL TAKE THE LONGEST TO CLEAR.
THE FRONTAL SYSTEM WILL BECOME DIFFUSE AND ORIENTED FROM WEST-EAST
TONIGHT...AS IT DRIFTS SWD AND SETTLES NEAR THE MASON DIXON LINE.
DRYING ALOFT AND WSHIFT TO THE WEST WILL RESULT IN DIMINISHING
PCPN ACTIVITY WITH JUST SOME PATCHY LIGHT RAIN OR DZ FOR THE
OVERNIGHT HOURS. LOWS WILL AGAIN BE FIRMLY ON THE MILD SIDE OF
CLIMO.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
GRADUALLY RISING HEIGHTS AND ZONAL FLOW ALOFT WILL MEAN THAT THE
WEAKENING COLD FRONT /SLIDING SOUTHEAST OF THE REGION EARLY MONDAY/
WILL LEAD TO NO REAL TEMP CHANGE THROUGH EARLY IN THE UPCOMING
WEEK.
IN FACT...THE FLOOD OF PACIFIC AIR /WARMED SIGNIFICANTLY BY
DOWNSLOPE IN THE LEE OF THE ROCKIES/ WILL BRING UNSEASONABLY MILD
TEMPS IN THE 50S MONDAY...AND 50S/60S FOR TUESDAY. 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.
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 /16Z SUNDAY THROUGH THURSDAY/...
10AM UPDATE...
WIDESPREAD LOW CLOUDS AND FOG CONTINUE TO AFFECT MOST OF MY
CENTRAL AND EASTERN TERMINALS. MEANWHILE RAIN IS MOVING INTO MY
NWRN FCST AREA BRING REDUCED CONDITIONS THERE. ONLY SITE WITH NO
PROBLEMS AS OF 10AM IS JST WHICH HAS BROKEN OUT INTO THE WARM AIR
AND CURRENTLY IS REPORTING CLEAR SKIES AND UNLIMITED VIZ.
THE AREAS AFFECTED BY THE LOW CLOUDS AND FOG WILL SEE ONLY GRADUAL
IMPROVEMENT TODAY AS MOST OF THE REGION REMAINS COLD AIR DAMMED
AND MIXING IS LIMITED. MEANWHILE A MORE GENERAL LIGHT RAIN WILL
OVERSPREAD THE FCST AREA AFTER MID DAY...SO PROSPECTS FOR
SIGNIFICANT IMPROVEMENT DO NOT LOOK PROMISING.
A WEAK FRONTAL SYSTEM CROSSING THE GREAT LAKES WILL MOVE THROUGH
THE AIRSPACE THIS EVE AND EARLY TNT...ACCOMPANIED BY RAIN AND
WIDESPREAD MVFR/IFR. REDUCED CIGS AND VSBYS SHOULD PREVAIL OVR
THE WRN SITES EVEN BEHIND THE FRONT...WITH WEAK UPSLOPE PRODUCING
AREAS OF -RA/DZ. DOWNSLOPE FLOW EAST OF THE MTNS SHOULD ALLOW
MVFR THRU THE END OF THE PD.
OUTLOOK...
MON...MORNING MVFR/IFR...BECMG VFR DURING THE AFTERNOON.
TUE...VFR TO MVFR WITH RAIN SHOWERS. ISOLD TSTMS PSBL. WSHFT.
WED...MVFR WEST WITH SNOW/RAIN SHOWERS.
THU...NO SIG WX.
&&
.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.
SEE PHLCLSIPT AND PHLCLSMDT FOR THE FALL SEASONAL SUMMARIES AT
WILLIAMSPORT AND HARRISBURG. THESE CAN BE FOUND AT
WEATHER.GOV/CTP.
&&
.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...LA CORTE/STEINBUGL
NEAR TERM...LA CORTE/STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...LAMBERT
AVIATION...LA CORTE/STEINBUGL
CLIMATE...LA CORTE
EQUIPMENT...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
930 AM EST SUN DEC 2 2012
.SYNOPSIS...
A WARM FRONT WEDGED ALONG THE EAST-SIDE OF THE ALLEGHENIES WILL
LIFT NORTHEAST THROUGH NEW ENGLAND TODAY...AHEAD OF A WEAK FRONTAL
SYSTEM PUSHING OUT OF THE GREAT LAKES. THE FRONTAL SYSTEM WILL BE
ACCOMPANIED BY A BAND OF RAIN AS IT MOVES THROUGH THE REGION THIS
EVENING. ABOVE NORMAL TEMPERATURES WILL PERSIST THROUGH EARLY NEXT
WEEK BEFORE A COLD FRONT PASSES TUESDAY NIGHT AND BRINGS MORE
SHOWERS AND A RETURN TO MORE SEASONAL TEMPERATURES FOR THE MIDDLE
OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
9AM UPDATE...
THE FOG ADVISORY HAS BEEN ALLOWED TO EXPIRE AS MOST REPORTING
SITES ARE NOW A MILE OR MORE.
ELSEWHERE SHOWERS CONTINUE TO PROGRESS SLOWLY OUT OF THE NW
MOUNTAINS. HRRR SUGGESTS THE RAIN MAKES ITS BIG PUSH INTO THE
CENTRAL PART OF THE STATE AFTER ABOUT MID DAY...BUT OVERALL QPF
SHOULD STILL REMAIN MOSTLY ON THE LIGHT SIDE. IT`S BEEN VERY DRY
SO ANY RAIN WILL BE WELCOME.
VERY MILD AIR HAS SURGED UP WEST OF THE ALLEGHENIES...BUT WHILE WE
REMAIN COOL AIR DAMMED...TEMPS ARE STILL MILD FOR THE TIME OF
YEAR AND WILL CONTINUE AS SUCH INTO THE NEW WORKWEEK.
&&
.SHORT TERM / MONDAY THROUGH 6 AM MONDAY/...
WARM FRONT WEDGED ALONG THE EAST-SIDE OF THE ALLEGHENIES WILL
LIFT NWD TDY...ALLOWING A SW FLOW OF UNSEASONABLY MILD AIR TO
OVERSPREAD THE ENTIRE AREA. AREAS OF FOG AND LOW STRATUS IN THE
CNTRL AND EASTERN ZONES WILL GRADUALLY IMPROVE/LIFT THRU LATE
MORNING.
A FAST MOVING LOW-AMPLITUDE SHORTWAVE TROUGH OF PACIFIC ORIGIN WILL
MOVE FROM THE GREAT LAKES/OH VALLEY INTO THE NERN STATES BY EVENING.
STG SWLY LOW LEVEL JET AHEAD OF ITS ASSOC FRONT WILL TRANSPORT ABV
NORMAL PWATS ENEWD ACROSS THE UPPER OH VALLEY INTO CENTRAL PA BY
THIS AFTN. THIS WILL SUPPORT HI POPS WITH LGT TO MOD PCPN TOTALS
EXPECTED. QPF AMTS WILL DROP OFF FROM NW TO SE...AS AREAS EAST OF
THE ALLEGHENY FRONT NEVER SEEM TO DO WELL IN TERMS OF QPF WITH SWLY
LLVL FLOW DUE TO COMBO OF DOWNSLOPE AND LACK OF LLVL CONVERGENCE.
THE BEST MID-UPPER FORCING STAYS TO THE NORTH SO AGAIN NOT LOOKING
AT ANY SIGNIFICANT PCPN WITH THIS RATHER WEAK FRONTAL SYSTEM.
DESPITE EXTENSIVE CLOUD COVER...THE UNSEASONABLY MILD SWLY FLOW
WILL ALLOW TEMPS TO CLIMB 5-10F ABOVE EARLY DECEMBER CLIMATE
NORMALS. MAX TEMPS WILL RANGE FROM NR 60F IN THE VALLEYS OF SW AND
SC PA...TO AROUND 50F OVR THE HIGH TERRAIN NORTH OF IPT WHERE THE
WARM FRONT WILL TAKE THE LONGEST TO CLEAR.
THE FRONTAL SYSTEM WILL BECOME DIFFUSE AND ORIENTED FROM WEST-EAST
TONIGHT...AS IT DRIFTS SWD AND SETTLES NEAR THE MASON DIXON LINE.
DRYING ALOFT AND WSHIFT TO THE WEST WILL RESULT IN DIMINISHING
PCPN ACTIVITY WITH JUST SOME PATCHY LIGHT RAIN OR DZ FOR THE
OVERNIGHT HOURS. LOWS WILL AGAIN BE FIRMLY ON THE MILD SIDE OF
CLIMO.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
GRADUALLY RISING HEIGHTS AND ZONAL FLOW ALOFT WILL MEAN THAT THE
WEAKENING COLD FRONT /SLIDING SOUTHEAST OF THE REGION EARLY MONDAY/
WILL LEAD TO NO REAL TEMP CHANGE THROUGH EARLY IN THE UPCOMING
WEEK.
IN FACT...THE FLOOD OF PACIFIC AIR /WARMED SIGNIFICANTLY BY
DOWNSLOPE IN THE LEE OF THE ROCKIES/ WILL BRING UNSEASONABLY MILD
TEMPS IN THE 50S MONDAY...AND 50S/60S FOR TUESDAY. 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.
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 /14Z SUNDAY THROUGH THURSDAY/...
02/12Z - 03/12Z...
WDSPRD FOG AND LOW STRATUS COVERS CENTRAL AND ERN TAF SITES...AS
RELATIVELY MOIST SE FLOW INTERSECTS WARM FRONT WEDGED ALONG THE
EAST-SIDE OF THE ALLEGHENIES. HIGH CONFIDENCE IN IFR-LIFR CONDS AT
MDT/LNS WITH CIGS/VIS BLW AIRFIELD MINS AT TIMES. MVFR-IFR CONDS
EXPECTED AT IPT/UNV/AOO...WITH VFR IN THE WARM SECTOR/WEST OF THE
WARM FRONT AT JST/BFD.
STG SSWLY LLJ WILL PRODUCE A PERIOD OF LLWS FROM MID-MORNING THRU
LATE AFTN. ANTICIPATE SOME IMPROVEMENT OVR ERN SXNS BY THE EARLY
AFTN AS WARM FRONT LIFTS NWD INTO NEW ENGLAND...AND WINDS CONTINUE
TO VEER/TURN MORE TO THE SOUTH-SOUTHWEST. FRONTAL SYSTEM CROSSING
THE GREAT LAKES WILL MOVE THROUGH THE AIRSPACE THIS EVE AND EARLY
TNT...ACCOMPANIED BY A BAND OF LGT-MOD RAIN. REDUCED CIGS AND
VSBYS SHOULD PREVAIL OVR THE WRN SITES BEHIND THE FRONT...WITH
WEAK UPSLOPE PRODUCING IFR CIGS AND AREAS OF -RA/DZ. DOWNSLOPE
FLOW EAST OF THE MTNS SHOULD ALLOW MVFR THRU THE END OF THE PD.
OUTLOOK...
MON...MVFR/IFR CIGS LKLY WEST.
TUE...VFR TO MVFR WITH RAIN SHOWERS. ISOLD TSTMS PSBL. WSHFT.
WED...MVFR WEST WITH SNOW/RAIN SHOWERS.
THU...NO SIG WX.
&&
.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.
SEE PHLCLSIPT AND PHLCLSMDT FOR THE FALL SEASONAL SUMMARIES AT
WILLIAMSPORT AND HARRISBURG. THESE CAN BE FOUND AT
WEATHER.GOV/CTP.
&&
.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...LA CORTE/STEINBUGL
NEAR TERM...LA CORTE/STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...LAMBERT
AVIATION...STEINBUGL
CLIMATE...LA CORTE
EQUIPMENT...LA CORTE
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
347 PM EST SUN DEC 2 2012
.SYNOPSIS...
HIGH PRESSURE WILL LINGER ACROSS THE REGION THROUGH MONDAY. A COLD
FRONT WILL THEN CROSS THE CAROLINAS AND NORTHEAST GEORGIA LATE
TUESDAY INTO WEDNESDAY. IN THE FRONTS WAKE...CANADIAN HIGH PRESSURE
WILL RETURN FOR THE LATTER PORTION OF THE WORK WEEK.
&&
.NEAR TERM /THROUGH MONDAY/...
330 PM UPDATE...NO SIGNIFICANT CHANGES TO FCST. TOUCHED UP TEMPS AND
SKY COVER PER LATEST OBS BUT EVENING TRENDS LOOK FINE.
UPPER LEVEL SHORT WAVE TROUGH MOVING ACROSS THE EASTERN GREAT LAKES
INTO NEW ENGLAND LATE THIS AFTERNOON AND THIS EVENING WILL PUSH THE
ASSOCIATED SURFACE COLD FRONT INTO THE EASTERN GREAT LAKES AND
NORTHERN MID-ATLANTIC REGION BY MORNING. THE FRONTAL CLOUDS AND THE
CLOUDS PRODUCED BY PRE-FRONTAL CONVECTION WILL EDGE INTO THE
FORECAST AREA DURING THE NIGHT. DO NOT EXPECT ANY PRECIPITATION WITH
THIS CLOUD BAND... BUT IT COULD DIMINISH AN OTHERWISE FAVORABLE
SETUP FOR MORNING FOG... AND POSSIBLY SOME STRATUS... BY DECREASING
RADIATIONAL COOLING AND WEAKENING THE BOUNDARY LAYER INVERSION.
DURING MONDAY... AS THE SHORT WAVE TROUGH MOVES FROM NEW ENGLAND
INTO THE ATLANTIC PROVINCES... THE UPPER LEVEL RIDGE OVER THE
EASTERN STATES WILL INCREASE IN AMPLITUDE AND MAINTAIN SURFACE HIGH
PRESSURE ACROSS THE SOUTHEAST. THE FORECAST AREA WILL REMAIN IN THE
WARM SECTOR DURING MONDAY AS THE FRONT TO OUR NORTH DRIFTS TO THE
NORTH AND THE NEXT COLD FRONT IS STILL SOME DISTANCE TO THE WEST.
TEMPERATURES TONIGHT AND MONDAY ARE EXPECTED TO REMAIN QUITE A BIT
ABOVE NORMAL. THE LOWS MONDAY MORNING... NEAR 40 IN MOUNTAIN VALLEYS
AND UPPER 40S TO AROUND 50 ELSEWHERE... WILL BE ABOUT TEN DEGREES
ABOVE NORMAL. HIGH TEMPERATURES ON MONDAY... MID AND UPPER 60S IN
MOUNTAIN VALLEYS AND NEAR 70 OUTSIDE THE MOUNTAINS... WILL BE TEN TO
FIFTEEN DEGREES ABOVE NORMAL.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
AS OF 200 PM EST SUNDAY...HEIGHTS WILL DECREASE OVER THE REGION BY
MONDAY NIGHT AS A SHORT WAVE RIDGE AXIS MOVES OFF THE EAST COAST AND
A POSITIVELY TILTED UPPER TROUGH TRANSLATE EAST ACROSS THE
MISSISSIPPI VALLEY. THE UPPER TROUGH IS EXPECTED TO SWING ACROSS OUR
CWA LATE TUESDAY NIGHT INTO WED AFTERNOON AND MOVE OFFSHORE BY WED
NIGHT.
AT THE SURFACE...THE RIDGE OF HIGH PRESSURE WILL WEAKEN AND
GRADUALLY MOVE OFF THE EAST COAST ON TUESDAY AS A SURFACE COLD FRONT
APPROACHES FROM THE WEST. EXPECT INCREASING CLOUD COVER AND WARMER
TEMPERATURES OVER THE REGION AS THE LLVL SOUTHWESTERLY WINDS
INCREASE AHEAD OF THE FRONT. TEMPERATURES WILL BE AROUND 10
DEGREES ABOVE NORMAL WITH AFTERNOON HIGHS WARMING INTO THE LOW 70S
OVER THE PIEDMONT AND 60S IN THE MOUNTAINS/VALLEYS.
THE COLD FRONT WILL MOVE INTO THE APPALACHIANS BY 12Z WED AND
CROSSES OUR CWA THROUGH 18Z WED. MODELS HAVE TRENDED A BIT WETTER
AND SLOWER WITH THE FROPA BUT STILL LOOKING UNIMPRESSIVE WITH REGARD
TO UPPER FORCING AND MOISTURE AVAILABILITY WITH THE SYSTEM. THE BEST
UPPER FORCING WILL MOVE WELL TO OUR NORTH AND THE PRECIP AMOUNTS
DECREASE ALONG THE FRONT AS IT PUSHES ACROSS OUR CWA. THE LATEST NAM
AND THE GFS SHOW A BIT OF CAPE VALUES...UP TO 200J/KG MAINLY OVER
OUR SOUTHERN SECTIONS ON WED AFTERNOON. BUT DUE TO WEAK WIND SHEAR
ALOFT...SHOULD NOT SUPPORT SEVER WEATHER AT THIS TIME. POPS HAVE
BEEN ADJUSTED ACCORDINGLY AND SHOULD TAPER OFF BY WED AFTERNOON.
TEMPERATURES WILL BE AROUND 3-5 DEGREES ABOVE NORMAL ON WEDNESDAY
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 2 PM SUNDAY...THE FIRST PART OF THE MEDIUM RANGE STILL LOOKS
FAIRLY QUIET...BUT THE SITUATION MAY GET MORE ACTIVE TOWARD THE END
OF THE PERIOD. AFTER SOME LINGERING SLIGHT CHC OF PRECIP ON THE BACK
SIDE OF THE FRONT WEDNESDAY EVE...EXPECT SOME DRYING FOR THURSDAY
AND THURSDAY NIGHT WITH A FLAT UPPER PATTERN AND SURFACE HIGH
PRESSURE RIDGING DOWN FROM THE N. THIS MAY BE SHORT LIVED...
THOUGH...AS THE MODELS SUGGEST MOISTURE RETURN AS EARLY AS LATE
THURSDAY NIGHT. IT HELPS THAT THE FRONT NEVER MAKES IT VERY FAR TO
OUR SOUTH DURING MIDWEEK. AT ANY RATE...LOW LEVEL MOISTURE WILL BE
ON HAND FOR FRIDAY AND SATURDAY WITH THE MODELS SHOWING A PROLONGED
SW FLOW FROM THE GULF. A FEW WEAK UPPER WAVES WILL PASS THROUGH ON
FRIDAY AND SATURDAY WHICH WILL ENHANCE THE POSSIBILITY OF SOME
SHOWER ACTIVITY. THE GUIDANCE POP WAS ACCEPTED FOR THIS FCST EVEN
THOUGH CONFIDENCE IS BETTER THAT MOST LOCATIONS WILL REMAIN DRY FOR
THE EARLY PART OF THE WEEKEND. THE MODELS DIVERGE LATE IN THE PERIOD
WITH THE TIMING AND AMPLITUDE OF AN UPPER TROF OVER THE PLAINS. THE
FCST SPLITS THE DIFFERENCE BETWEEN THE FASTER 00Z RUN OF THE
ECMWF...WHICH WOULD BRING THE NEXT MORE SIGNIFICANT COLD FRONT INTO
THE MTNS BY SUNSET SUNDAY...AND THE SLOWER GFS WHICH LAGS IT BACK
ACROSS THE MS VALLEY. A CHANCE POP WAS MAINTAINED ACROSS THE ENTIRE
FCST AREA FOR THE SATURDAY NIGHT AND SUNDAY TIME FRAME. TEMPS SHOULD
STAY ABOVE NORMAL.
&&
.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
21Z UPDATE...FOR KCLT...CURRENT TAF MAINTAINS GUST POTENTIAL TO 23Z
AND THAT TIMING SEEMS APPROPRIATE GIVEN RAP SOUNDINGS AND KGSP VAD
WIND PROFILE SHOWING 15KT WINDS NEAR TOP OF MIXED LAYER. CLOUDS ARE
NOT LIKELY TO FURTHER DEVELOP OR FORM A CIG THIS AFTN. DID ALSO
UPDATE KAVL TAF TO INCLUDE SOME LOW END GUSTS THIS AFTN FOR SIMILAR
REASONS...THOUGH GUSTS SHOULD BECOME LESS FREQUENT AS WE APPROACH
SUNSET.
AT KCLT... BROKEN TO SCATTERED CLOUDS 3-5K FT WILL CONTINUE THIS
AFTERNOON AND VISIBILITY WILL BE UNRESTRICTED. HIGH PRESSURE SYSTEM
EXTENDING INTO THE AREA FROM THE NORTHEAST WILL PRODUCT A SOUTHWEST
WIND AROUND 10 KT. OVERNIGHT... SCATTERED CLOUDS AROUND 3K FT WILL
PERSIST. AFTER 08Z VISIBILITY AROUND 5 MILES IN FOG WILL DEVELOP.
CONDENSATION PRESSURE DEFICITS AND BOUNDARY LAYER INVERSION TOWARD
DAYBREAK CREATE FAVORABLE CONDITIONS FOR FOG... BUT HIGHER CLOUDS
JUST TO THE NORTH OF THE TERMINAL COULD EDGE INTO THE AREA THUS
DIMINISHING RADATIONAL COOLING AND THE MOST FAVORABLE SETUP FOR FOG.
AFTER 14Z... VISIBILITY WILL BECOME UNRESTRICTED WITH SCATTERED
CLOUD NEAR 4K FT. WIND WILL BE SOUTHWEST NEAR 10 KT.
REMAINDER TERMINALS... BROKEN TO SCATTERED CLOUDS 3-5 KT FT WILL
CONTINUE THIS AFTERNOON AND INTO THE EVENING WITH VISIBILITY
UNRESTRICTED. AFTER 06Z... AREAS OF FOG 3-5 MILES WILL DEVELOP DUE
TO FAVORABLE CONDENSATION PRESSURE DEFICITS AND BOUNDARY LAYER
INVERSION. VISIBILITY VICINITY KAVL LIKELY TO LOWER TO AROUND 1 MILE
IN FOG BY 10Z. IF HIGHER CLOUDS JUST TO THE NORTH OF THE FORECAST
AREA MOVE FURTHER SOUTH THAN EXPECTED OVERNIGHT... SURFACE COOLING
WILL BE DIMINISHED SOMEWHAT AND FOG WILL BE LESS LIKELY. VISIBILITY
WILL BECOME UNRESTRICTED AFTER 14Z.
OUTLOOK...LOW LEVEL MOISTURE MAY CREATE RESTRICTIONS AGAIN TUESDAY
MORNING. A COLD FRONT IS EXPECTED TO CROSS THE REGION TUESDAY NIGHT
AND EARLY WEDNESDAY...WITH DRY HIGH PRESSURE RETURNING MID TO LATE
WEEK.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JPT
NEAR TERM...LGL/WIMBERLEY
SHORT TERM...JOH
LONG TERM...PM
AVIATION...LGL/WIMBERLEY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1001 AM EST SUN DEC 2 2012
.SYNOPSIS...
HIGH PRESSURE WILL LINGER ACROSS THE SOUTHEAST BRINGING DRY
CONDITIONS THROUGH MONDAY. A COLD FRONT WILL CROSS THE CAROLINAS AND
NORTHEAST GEORGIA LATE TUESDAY INTO WEDNESDAY...BEFORE CANADIAN HIGH
PRESSURE RETURNS LATER IN THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AT 930 AM... WEB CAMS SHOW A LITTLE BIT OF FOG PERSISTING IN SOME OF
THE MOUNTAIN VALLEYS. HIGHER CLOUD IS LIKELY SLOWING THE DISSIPATION
PROCESS A LITTLE BIT BY CUTTING DOWN ON SURFACE WARMING AND
SUBSEQUENT MIXING. WILL CARRY FOG FOR A COUPLE OF HOURS... BUT
REMAINDER FORECAST VIRTUALLY UNCHANGED EXCEPT FOR UPDATING
TEMPERATURES AND DEWPOINTS FOR CURRENT CONDITIONS.
AS OF 630 AM...LATEST RADAR IMAGES INDICATE THAT LIGHT SHRA TO
SPRINKLES EXTENDED ALONG THE HIGH TERRAIN ALONG THE NC/SC/GA BORDER
NE TO THE NC FOOTHILLS. I WILL UPDATE THE FORECAST TO ADJUST POPS.
IN ADDITION...WIDESPREAD HIGH CLOUDS HAS RESULTED IN LESS FOG THAN
PREVIOUSLY EXPECTED...I WILL REDUCE FOG MENTION FOR THE UPDATE.
AS OF 230 AM...LATEST IMAGES FROM THE KGSP RADAR INDICATED A FEW
SHOWERS ACROSS THE FOOTHILLS AND MTNS OF NE GA AND SC. THESE SHOWERS
ARE LIKELY SUPPORTED BY UPSLOPE FLOW AND 290K ISENTROPIC LIFT. THE
0Z NAM INDICATES THAT LLVL LIFT MAY INCREASE THROUGH SUNRISE...THEN
WILL GRADUALLY WEAKEN AS LLVL WIND VEER WEST. I WILL INDICATE AN
AREA OF INCREASING SCHC POPS ACROSS THE NRN SC UPSTATE AND NE GA
THROUGH SUNRISE...THE COVERAGE WILL FADE BY MID DAY. SIMILARLY...I
EXPECT THAT CLOUD COVER WILL INCREASE THROUGH DAYBREAK...THEN CLOUD
COVER SHOULD SLOWLY DECREASE FROM WEST TO EAST THROUGH THE REST OF
THE DAY. SW WINDS SHOULD INCREASE LLVL THICKNESSES AND TEMPERATURE
PROFILES THROUGH THIS AFTERNOON. MOS CONSENSUS SUPPORT HIGH
TEMPERATURES AROUND 10 DEGREES ABOVE NORMAL.
TONIGHT...A WEAK COLD FRONT IS EXPECTED TO MOVE ACROSS THE CENTRAL
APPALACHIANS AND BECOME NEARLY STATIONARY BY 12Z MON. THE BOUNDARY
IS EXPECTED TO REMAIN NORTH OF THE CWA...LEAVING THE FORECAST AREA
IN THE WARM SECTOR. IN ADDITION...CLOUD COVER ASSOCIATED WITH THE
BORDER WILL LIKELY RESULT IN INCREASE COVERAGE ACROSS THE MTNS AND
NC FOOTHILLS AND PIEDMONT. MIN TEMPERATURES WILL LIKELY REMAIN
AROUND 10 DEGREES ABOVE NORMAL GIVEN THE LINGERING WARM LLVL
PROFILES AND CLOUD COVER.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 205 AM EST SUNDAY...A SHORT WAVE RIDGE WILL BUILD ACROSS THE
REGION DURING THE DAY ON MONDAY. AT THE SFC THE LLVL FLOW WILL TURN
OUT OF THE WEST EARLY IN THE DAY. THE DOWNSLOPE FLOW AND GENERALLY
LIGHT BNDRY LAYER WIND SPEEDS SHOULD LIMIT LOW AND MID LEVEL CLOUD
COVER WITH THE BALANCE OF THE DAY EXPECTED TO BE MOSTLY SUNNY. H8
TEMPS WILL INCREASE TO AROUND 9 DEG C WHICH SHOULD SUPPORT HIGH
TEMPS 10 TO 12 DEGREES ABOVE NORMAL.
THE ZONAL FLOW WILL BUCKLE A LITTLE ACROSS THE CENTRAL STATES ON
TUESDAY. HOWEVER...THE MODELS CONTINUE TO HAVE A BROAD...TRANSITORY
AND RATHER WEAK TROUGH. THE UP SIDE OF THIS THIS THAT THERE WILL BE
NO SEVERE WEATHER THREAT WITH THE TROUGH. THE DOWN SIDE IS THAT THE
LOW AMPLITUDE WILL SUPPORT LITTLE IN THE WAY OF RETURN FLOW AND THE
FRONTAL BAND SHOULD WEAKEN AS IT ENTERS THE MOUNTAINS LATE TUE
NIGHT. ALONG THE TN LINE A QUARTER TO A HALF INCH OF RAIN IS
POSSIBLE...BUT AMOUNTS FARTHER TO THE EAST APPEAR AT THIS TIME AS IF
THEY WILL BE SIGNIFICNATLY LIGHTER. I DID BUMP POPS UP INTO THE
LIKELY RANGE ALONG THE TN LINE LATE TUE NIGHT...IN LINE WITH THE
SREF 3 HOURLY POPS. AS FOR HIGH TEMPS DURING THE DAY ON
TUESDAY...THEY SHOULD BE AS WARM OR WARMER AS MONDAY/S HIGHS...
WARMING INTO THE LOWER 70S OUTSIDE THE MTNS.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 250 AM SUNDAY...NO NEED TO MAKE ANY SIGFNT CHANGES TO THE EXT
RANGE FCST. THE OP MODELS ARE IN GOOD AGREEMENT...AT LEAST THROUGH
THE FIRST HALF OF THE PERIOD. A CONTINUED EASTWARD PROGRESSION OF THE
UPPER WAVE IS ANTICIPATED WITH LITTLE DYNAMICAL RESPONSE AS SFC
BASED LAYERED SHEAR WILL REMAIN LOW. THE SFC FRONT WILL BE WEAKENING
AS IT MOVES EAST OF THE AREA WITH LESS AND LESS UPPER SUPPORT. THE
GFS IS STILL QUICKER WITH A FROPA WHILE THE ECWMF INDICATES A BETTER
CHANCE OF INSTABILITY DEVELOPING OVER THE SRN MOST ZONES. THIS IDEA
IS STILL NOT SUPPORTED BY ANY OTHER MODEL NOR STATISTICAL
GUIDANCE...SO ANY MENTION THUNDER WILL REMAIN OUT OF THE FCST.
MOST OF THE FRONTAL PRECIP WILL FALL ACROSS THE NC MTNS EARLIER AND
LINGERING QPF AMOUNTS WILL BE 0.25 OR LESS...UNLESS SOME DEEPER
CONVECTION ACTUALLY MATERIALIZES DURING THE AFTERNOON.
ANOTHER CP SFC HIGH BUILDS IN QUICKLY THU AND THIS WILL HOLD MAX
TEMPS DOWN FROM WED/S HIGHS BY ABOUT 8-10 DEGREES OR RIGHT AROUND
NORMAL. TEMPS WILL SLOWLY MODIFY A COUPLE DEGREES FRI IN GOOD
INSOLATION. IT LOOKS PROBABLE THAT A NRN GOM SYSTEM WILL MOVE UP THE
TN VALLEY THROUGH SAT AND INCREASING CLOUD COVER WILL HOLD TEMPS IN
CHECK...SIMILAR TO FRI/S HIGHS. THE GOING POPS FOR LATE FRI INTO SAT
LOOK GOOD WITH THE WRN MOST ZONES RECEIVING A LOW END CHANCE MENTION
AND ISOL ELSEWHERE. LOW END DYNAMICS AND A CONTINUED STABLE AIRMASS
WILL OFFSET ANY THUNDER MENTION ONCE AGAIN.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
AT KCLT... LATEST RAP INDICATES CLOUD LAYER NEAR 7K FT WILL
DISSIPATE AROUND 18Z OR SHORTLY THEREAFTER BUT LOWER SCATTERED TO
BROKEN DECK CORRESPONDING TO CURRENT 4K FT LAYER WILL PERSIST. LATE
MORNING TAF UPDATED WILL REFLECT THIS TREND WHICH IS SIMILAR TO
CURRENT FORECAST. VERY LIGHT SURFACE PRESSURE GRADIENT SHOULD KEEP
SOUTHWEST WIND SPEEDS LESS THAN 10 KT. NO SIGNIFICANT WEATHER AFTER
00Z UNTIL POSSIBILITY OF LOW STRATUS AND FOG INCREASES. THE NAM
FORECAST SOUNDINGS INDICATE A STRONG BL INVERSION LATE TONIGHT.
CONDENSATION PRESSURE DEFICITS FALL TO NEAR 0 MBS ACROSS MOST OF THE
PIEDMONT BY 12Z MON. IT APPEARS THAT CONDITIONS WILL FAVOR IFR
CEILINGS AND FOG MONDAY MORNING.
ELSEWHERE...CONDITIONS WILL REMAIN VFR ACROSS THE WESTERN CAROLINAS
THIS AFTERNOON. SOUTHWEST WINDS WILL STRENGTHEN TO 5 TO 7 KTS...BUT
DECREASING TO 3 KTS AFTER SUNSET. CLOUD COVER MAY DECREASE LATE
TONIGHT AS LLVL WIND FIELDS VEER SW. THE NAM FORECAST SOUNDINGS
INDICATE A STRONG BL INVERSION LATE TONIGHT ACROSS THE
PIEDMONT...LESS DEFINED ACROSS FOOTHILLS AND MTNS.
HOWEVER...CONDENSATION PRESSURE DEFICITS DECREASE TO NEAR ZERO
ACROSS THE I-85 CORRIDOR TERMINALS AND MTNS VALLEYS.
OUTLOOK...LOW LEVEL MOISTURE MAY CREATE RESTRICTIONS AGAIN TUESDAY
MORNING. A COLD FRONT IS EXPECTED TO CROSS THE REGION TUESDAY
NIGHT...WITH DRY HIGH PRES RETURNING MID TO LATE WEEK.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...SBK
NEAR TERM...LGL
SHORT TERM...MCAVOY
LONG TERM...SBK
AVIATION...LGL/NED
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
308 AM MST SUN DEC 2 2012
.DISCUSSION...CURRENT SURFACE ANALYSIS SHOWS LOW PRESSURE OVER
SOUTHWESTERN SK...WITH WARM FRONT EXTENDING SOUTHEASTWARD ACROSS
NORTHEASTERN MT INTO SOUTHWESTERN ND AND CENTRAL SD. COLD FRONT
EXTENDS WESTWARD FROM THE LOW ACROSS SOUTHWESTERN CANADA. UPPER
LEVEL ANALYSIS CONTINUES TO SHOW LOW OFF THE PACIFIC NW
COAST...WITH FAST WEST TO SOUTHWEST FLOW ACROSS THE WESTERN CONUS
INTO THE PLAINS. HIGH CLOUDINESS CONTINUES TO PASS OVER THE REGION
WITH VARIABLY CLOUDY SKIES. TEMPS ARE MOSTLY IN THE 30S AND LOWER
40S ACROSS THE AREA...WITH WARMER TEMPS ACROSS PORTIONS OF
NORTHEASTERN WY AND THE BLACK HILLS AREA WHERE THERE ARE DOWNSLOPING
WINDS. WINDS ARE GENERALLY FROM THE WEST TO SOUTHWEST ACROSS THE
FORECAST AREA...BREEZY AT TIMES ACROSS PORTIONS OF NORTHEASTERN
WY.
WARM CONDITIONS WILL CONTINUE TODAY...WITH TEMPS 20 TO 30 DEGREES
ABOVE AVERAGE. GUSTY SOUTHWESTERLY WINDS CAN BE EXPECTED ACROSS
NORTHEASTERN WY AND PORTIONS OF THE BLACK HILLS LATER THIS MORNING
INTO TONIGHT. COLD FRONT WILL MOVE ACROSS THE FORECAST AREA LATE
TONIGHT...BRINGING A CHANCE OF SHOWERS TO MAINLY NORTHERN PORTIONS
OF THE AREA AND STRONG NORTHWESTERLY WINDS FOR MONDAY ACROSS
NORTHWESTERN SD. TEMPS WILL BE COOLER THROUGH THE FIRST HALF OF
THE COMING WEEK...BUT STILL ABOVE AVERAGE.
FOR TODAY...SKIES WILL BE PARTLY TO MOSTLY SUNNY WITH HIGH CLOUDS
PASSING OVERHEAD. HIGHS WILL RANGE FROM THE MID 50S OVER THE
HIGHER BLACK HILLS TO THE UPPER 60S TO NEAR 70 DEGREES ACROSS
PORTIONS OF THE SOUTHWESTERN AND SOUTH CENTRAL SD PLAINS. NEAR
RECORD HIGHS ARE EXPECTED OVER PORTIONS OF THE AREA...WITH THE
RECORD HIGH FOR THIS DATE AT RAP AIRPORT BEING 69 AND EAST RAPID
CITY AT 70. SOUTHWESTERLY WINDS WILL INCREASE ACROSS NORTHEASTERN
WY AND THE BLACK HILLS LATER THIS MORNING...BECOMING RATHER GUSTY
BY THE AFTERNOON IN FAVORED AREAS. SOME WIND GUSTS TO NEAR 50 MPH
ARE LIKELY ACROSS CAMPBELL CO WY AND DOWNSLOPE AREAS OF THE
NORTHERN BLACK HILLS. THESE GUSTY WINDS WILL CONTINUE INTO THE
EVENING UNTIL THE COLD FRONT PASSES.
COLD FRONT WILL PASS THROUGH NORTHWESTERN PORTIONS OF THE CWA
LATE THIS EVENING AND THROUGH THE REST OF THE FORECAST AREA LATE
TONIGHT. UPPER LOW ASSOCIATED WITH FRONT WILL PASS WELL TO THE
NORTH OF THE REGION...WITH WEAKER SHORTWAVE ENERGY PASSING ACROSS
OUR AREA WITH THE FRONT. SHOWER CHANCES WILL MAINLY BE CONFINED TO
NORTHERN PORTIONS OF THE CWA...WITH THE BEST CHANCES ACROSS THE
NORTHERN BLACK HILLS AREA LATE TONIGHT. PCPN WILL GENERALLY BE IN
THE FORM OF RAIN...EXCEPT FOR POSSIBLY A LITTLE SNOW ACROSS THE
HIGHER ELEVATIONS OF THE BLACK HILLS. WINDS WILL SWITCH TO THE
NORTHWEST BEHIND THE FRONT AND LIKELY BE RATHER GUSTY FOR A
PERIOD BEHIND THE PASSAGE. SHOWERS SHOULD EXIT THE AREA BY MONDAY
MORNING...BUT IF TIMING OF FRONT IS A BIT SLOWER...THERE COULD BE
A LINGERING CHANCE INTO THE EARLY MORNING ACROSS FAR EASTERN
PORTIONS OF THE CWA.
WINDS WILL INCREASE MONDAY MORNING AS SUBSIDENCE DEVELOPS BEHIND
EXITING SHORTWAVE...COOLER AIR BUILDS IN TO THE AREA...AND
BOUNDARY LAYER MIXES OUT. ADVISORY CRITERIA WINDS STILL LOOK
LIKELY DURING THE LATE MORNING AND EARLY AFTERNOON HOURS ACROSS A
GOOD PORTION OF THE NORTHWESTERN SD PLAINS. FURTHER SOUTH INTO THE
WEST CENTRAL SD PLAINS...INCLUDING THE RAP AREA...THERE IS MORE
UNCERTAINTY OF STRONG WINDS WITH FLOW A BIT MORE WESTERLY THAN IS
USUALLY FAVORABLE FOR STRONGER WINDS. HIGHS WILL BE MOSTLY IN THE
50S...WITH SOME 40S ACROSS PORTIONS OF NORTHEASTERN WY AND THE
BLACK HILLS.
WINDS WILL DECREASE BY MONDAY EVENING...WITH QUIET WEATHER
EXPECTED INTO MIDWEEK. TEMPS WILL REMAIN ABOVE AVERAGE WITH HIGHS
IN THE MID 40S TO MID 50S ON TUESDAY AND LOWS IN THE 20S AND LOWER
30S.
EXTENDED...WARM AND DRY CONDITIONS WILL OCCUR ON WEDNESDAY WITH
ZONAL FLOW OVER THE AREA. A SFC COLD FRONT WILL BRING A CHANCE OF
RAIN OR SNOW AS IT PASSES THROUGH ON WEDNESDAY NIGHT. SHORTWAVE
ENERGY IN A BROAD UPPER TROUGH WILL CREATE A CHANCE OF RAIN OR
SNOW FROM THURSDAY INTO FRIDAY. TEMPERATURES ON THURSDAY WILL BE
NEAR NORMAL...WITH COLDER TEMPERATURES ON FRIDAY AND SATURDAY.
MODEL SOLUTIONS DIVERGE FOR SATURDAY AND SUNDAY...BUT WITH THE
POTENTIAL FOR AN UPPER TROUGH TO AFFECT THE REGION...WILL KEEP LOW
POPS IN THE FORECAST FOR THE END OF THE WEEK.
&&
.AVIATION...12Z TAFS
VFR CONDITIONS WILL PREVAIL TODAY WITH AREAS OF MID AND HIGH LEVEL
CLOUDS. THERE IS A CHANCE OF SHOWERS TONIGHT OVER NORTHEASTERN
WYOMING...THE BLACK HILLS AND NORTHWESTERN SOUTH DAKOTA. AREAS OF
MVFR CIGS MAY DEVELOP WITH THE SHOWERS...ESPECIALLY OVER PARTS OF
NORTHEASTERN WYOMING AND THE BLACK HILLS LATE TONIGHT. GUSTY
SOUTHWEST WINDS WILL BE FOUND ACROSS NORTHEASTERN WYOMING AND PARTS
OF THE BLACK HILLS TODAY.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...26
LONG TERM....10
AVIATION...10
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
620 AM CST SUN DEC 2 2012
.UPDATE...FOR 12Z AVIATION FORECAST
&&
.AVIATION...
MOISTURE TRANSPORT IS JUST NOT IMPRESSIVE AS FAR AS MIDDLE TENNESSEE
IS CONCERNED WITH BETTER TRANSPORT OCCURRING NORTHWARD DURING THE
DAY ALONG THE OHIO RIVER AND POINTS NORTH. MOISTURE TRANSPORT EVEN
BECOMES WEAKER BY AFTERNOON. THEREFORE EXPECT ISOLATED TO SCATTERED
LIGHT SHOWERS OR SPRINKLES TODAY MAINLY INTERSTATE 40 NORTHWARD
WITH VFR CONDITIONS PREVAILING DURING THE DAY AT AVIATION TERMINALS.
WITH WINDS AT THE TOP OF THE BOUNDARY LAYER ON THE ORDER OF 40 KNOTS
DURING THE DAY AND A RATHER TIGHT PRESSURE GRADIENT LOOK FOR GUSTS
TO 22 KNOTS AT THE SURFACE. I EXPECT CEILINGS WILL LOWER TO MVFR
AT CKV AFTER 03/00Z.
BOYD
&&
.PREV DISCUSSION... /ISSUED 327 AM CST SUN DEC 2 2012/
DISCUSSION...
FOR THE SHORT TERM...RADAR AND IR SATELLITE INDICATES SOME ISOLATED
LIGHT SHOWER ACTIVITY...LIKELY STRUGGLING TO REACH THE SURFACE...IN
SOUTHERN IL/IN AND WESTERN KY. HRRR AND RUC ALONG WITH THE
GFS/NAM/ECMWF ARE STUBBORN TO LEAVE THE NORTHWEST CORNER OF MIDDLE
TN OUT OF POP CHANCES AND HAVE ACTUALLY INCREASED THE POP CHANCES UP
THERE. THE AREA OF DEVELOPMENT IS EITHER COINCIDENT OR IN CLOSE
PROXIMITY TO THE LOW LEVEL JET CURRENTLY OVER THE MO BOOTHEEL AND
SOUTHERN IN. VAD WIND PROFILES AT BOTH HPX AND OHX SHOW 40 KT 2 AND 4
KFT WINDS AND WHILE INSTABILITY IS STILL VERY LOW...THE TURBULENCE
AND LOW LEVEL MOISTENING OF THE COLUMN ACCORDING TO LAPS/RUC SOUNDINGS
IN THE CKV AREA AND THE APPROACHING SURFACE TROUGH AXIS ARE ENOUGH
VARIABLES FOR KEEPING IN THE SLIGHT CHANCE FOR THE NORTHWEST THROUGH
00Z MONDAY. SREF ENSEMBLES KEEP THE ACTIVITY RIGHT ALONG THE KY/TN
BORDER THROUGH TOMORROW MORNING SO ALSO INCLUDED A SLIGHT CHANCE FOR
THE NORTHERN PERIPHERY OF THE CWA.
AS FAR AS TEMPS GO...KEPT THE NORTHWEST AND NORTH A FEW DEGREES
BELOW GUIDANCE AS CLOUD COVER SHOULD BE PRESENT NORTH OF I40
THROUGHOUT THE DAY. LIKEWISE...KEPT MIN TEMPS HIGHER THERE AS WELL
FOR TOMORROW MORNING.
LOOKING TOWARDS TUESDAY...ONCE AGAIN...HAVE PRETTY GOOD CONFIDENCE
IN THE PREVIOUS FORECAST DEPICTION OF THE APPROACHING COLD FRONT
PROGGED TO IMPACT MIDDLE TN BY 00Z WEDNESDAY GIVE OR TAKE A COUPLE
HOURS. THE ONLY NOTICEABLE DIFFERENCE IS THE INCREASING INSTABILITY
VALUES...SOUNDING CAPE VALUES NOW NEAR 400 J/KG...LIKELY DUE TO THE
COOLER MID LEVELS BEING DEPICTED AND THE SURFACE TEMPS NEAR 70. THIS
SHOULD TRANSLATE TO SOME BRIEF LOCALIZED DOWNPOURS...ESPECIALLY IN
THE NORTHWEST QUARTER OF THE CWA.
FOR THE EXTENDED...MODEL DISAGREEMENT CONTINUES. GFS STALLS A COLD
FRONT TO OUR NORTHWEST BY SATURDAY NIGHT KEEPING US RAINY THROUGH
TUESDAY OF THE FOLLOWING WEEK WHILE THE ECMWF SLOWLY BRINGS THE COLD
FRONT THROUGH THE BY LATE SUNDAY. WHILE THE UPPER LEVEL PATTERNS
DIFFER QUITE A BIT...THEY BOTH AT LEAST AGREE THAT RAIN WILL BE IN
THE FORECAST FOR THE WEEKEND. SO AT THE VERY LEAST...THE CONFIDENCE
IN LEAVING POP CHANCES IN THE EXTENDED HAS RISEN...BUT THE SPEFICICS
OF WHEN AND WHERE ARE YET TO BE DETERMINED. WILL DEFER TO LATER
MODEL RUNS AND SHIFTS TO FINE TUNE THE EXTENDED.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
01
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
327 AM CST SUN DEC 2 2012
.DISCUSSION...
FOR THE SHORT TERM...RADAR AND IR SATELLITE INDICATES SOME ISOLATED
LIGHT SHOWER ACTIVITY...LIKELY STRUGGLING TO REACH THE SURFACE...IN
SOUTHERN IL/IN AND WESTERN KY. HRRR AND RUC ALONG WITH THE
GFS/NAM/ECMWF ARE STUBBORN TO LEAVE THE NORTHWEST CORNER OF MIDDLE
TN OUT OF POP CHANCES AND HAVE ACTUALLY INCREASED THE POP CHANCES UP
THERE. THE AREA OF DEVELOPMENT IS EITHER COINCIDENT OR IN CLOSE
PROXIMITY TO THE LOW LEVEL JET CURRENTLY OVER THE MO BOOTHEEL AND
SOUTHERN IN. VAD WIND PROFILES AT BOTH HPX AND OHX SHOW 40 KT 2 AND 4
KFT WINDS AND WHILE INSTABILITY IS STILL VERY LOW...THE TURBULENCE
AND LOW LEVEL MOISTENING OF THE COLUMN ACCORDING TO LAPS/RUC SOUNDINGS
IN THE CKV AREA AND THE APPROACHING SURFACE TROUGH AXIS ARE ENOUGH
VARIABLES FOR KEEPING IN THE SLIGHT CHANCE FOR THE NORTHWEST THROUGH
00Z MONDAY. SREF ENSEMBLES KEEP THE ACTIVITY RIGHT ALONG THE KY/TN
BORDER THROUGH TOMORROW MORNING SO ALSO INCLUDED A SLIGHT CHANCE FOR
THE NORTHERN PERIPHERY OF THE CWA.
AS FAR AS TEMPS GO...KEPT THE NORTHWEST AND NORTH A FEW DEGREES
BELOW GUIDANCE AS CLOUD COVER SHOULD BE PRESENT NORTH OF I40
THROUGHOUT THE DAY. LIKEWISE...KEPT MIN TEMPS HIGHER THERE AS WELL
FOR TOMORROW MORNING.
LOOKING TOWARDS TUESDAY...ONCE AGAIN...HAVE PRETTY GOOD CONFIDENCE
IN THE PREVIOUS FORECAST DEPICTION OF THE APPROACHING COLD FRONT
PROGGED TO IMPACT MIDDLE TN BY 00Z WEDNESDAY GIVE OR TAKE A COUPLE
HOURS. THE ONLY NOTICEABLE DIFFERENCE IS THE INCREASING INSTABILITY
VALUES...SOUNDING CAPE VALUES NOW NEAR 400 J/KG...LIKELY DUE TO THE
COOLER MID LEVELS BEING DEPICTED AND THE SURFACE TEMPS NEAR 70. THIS
SHOULD TRANSLATE TO SOME BRIEF LOCALIZED DOWNPOURS...ESPECIALLY IN
THE NORTHWEST QUARTER OF THE CWA.
FOR THE EXTENDED...MODEL DISAGREEMENT CONTINUES. GFS STALLS A COLD
FRONT TO OUR NORTHWEST BY SATURDAY NIGHT KEEPING US RAINY THROUGH
TUESDAY OF THE FOLLOWING WEEK WHILE THE ECMWF SLOWLY BRINGS THE COLD
FRONT THROUGH THE BY LATE SUNDAY. WHILE THE UPPER LEVEL PATTERNS
DIFFER QUITE A BIT...THEY BOTH AT LEAST AGREE THAT RAIN WILL BE IN
THE FORECAST FOR THE WEEKEND. SO AT THE VERY LEAST...THE CONFIDENCE
IN LEAVING POP CHANCES IN THE EXTENDED HAS RISEN...BUT THE SPEFICICS
OF WHEN AND WHERE ARE YET TO BE DETERMINED. WILL DEFER TO LATER
MODEL RUNS AND SHIFTS TO FINE TUNE THE EXTENDED.
&&
.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE 69 55 74 55 / 20 05 05 10
CLARKSVILLE 67 57 75 56 / 20 20 05 10
CROSSVILLE 64 51 69 52 / 10 05 05 05
COLUMBIA 71 52 74 54 / 10 05 05 10
LAWRENCEBURG 71 51 74 53 / 05 05 05 10
WAVERLY 67 56 75 56 / 20 05 05 20
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
TB12
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
330 AM CST SUN DEC 2 2012
.SHORT TERM...TODAY THROUGH TUESDAY
330 AM CST SUN DEC 2 2012
FORECAST CONCERNS FOCUS ON THE DENSE FOG THIS MORNING...THEN THE
NEXT PCPN CHANCE AND AMOUNT OF WARMING FOR MONDAY.
AN AREA OF CLEARING HAS OPENED UP OVER SOUTHERN MN/FAR NORTHERN IA
EARLY THIS MORNING...PER FOG/STRATUS SATELLITE IMAGERY...BUT THERE
IS ALSO EVIDENCE OF SOME SOUTHERN PUSH IN LOW STRATUS FROM NORTHERN
MN. MEANWHILE...SFC OBS SHOW A WIDE VARIETY OF VSBYS...WITH MOST OF
THE DENSE FOG ACROSS IA...MOSTLY AHEAD OF A SFC FRONT. RAP13 RH
TRENDS WOULD TAKE THE BULK OF THE LOW SATURATION EAST EARLY THIS
MORNING...PUSHING THE CLEARING AREA INTO WESTERN WI BY 15Z OR SO.
SOME LIGHT STIRRING IN THE WIND BEHIND THE FRONT SEEMS TO HAVE A
POSITIVE IMPACT ON THE FOG...IMPROVING VSBYS A BIT. WINDS PROBABLY
WON/T PICK UP BEYOND THE LIGHT VARIETY UNTIL LATER IN THE AFTERNOON
AS A WEAK HIGH PRESSURE RIDGE SHIFTS OVER EASTERN WI BY 00Z. WHILE
SOME VSBYS HAVE IMPROVED OVER THE FORECAST AREA...THEY ARE SHOWING
SIGNS OF GOING DOWN AGAIN. WILL SIT WITH THE DENSE FOG ADVISORY AS
IS AS A RESULT...BUT SEE THE POTENTIAL FOR CANCELLING SOME AREAS
BEFORE 15Z BASED ON TRENDS. MEANWHILE...THE RAP13 BUFKIT SOUNDING AT
KLSE HOLDS ONTO A STRONG INVERSION THROUGH 18Z...AND THE LOW STRATUS
COULD HANG AROUND AS A RESULT. IT MAY NOT BREAK UP UNTIL LATE IN THE
AFTERNOON.
A SHORTWAVE TROUGH...JUST PUSHING ONTO THE WEST COAST EARLY THIS
MORNING - PER LATEST WATERVAPOR SATELLITE IMAGERY...WILL DRIVE DUE
EAST OVER THE NEXT COUPLE DAYS...MOVING ACROSS SOUTHERN CANADA AND
THEN DROPPING OVER THE GREAT LAKES ON TUE. ITS SFC FRONT WILL BE
FOUND WELL AHEAD OF THE UPPER LEVEL TROUGH...MOVING INTO WESTERN WI
MONDAY AFTERNOON. THIS HAS BEEN A CONSISTENT SIGNAL IN THE MODELS.
DECENT FRONTOGENETIC FORCING INDICATED WITH THE BOUNDARY WITH A
FETCH OF LOW LEVEL MOISTURE RETURN AHEAD OF IT. THE NAM EVEN
SUGGESTS AS MUCH AS 500 J/KG OF MUCAPE AHEAD OF THE FRONT. THE GFS
IS MUCH WEAKER. THE BETTER UPPER LEVEL FORCING WILL STAY NORTH WITH
THE SHORTWAVE. BUT...ENOUGH LOW LEVEL FORCING AND MOISTURE THAT SOME
PCPN LOOKS LIKELY ON MONDAY...MOSTLY AFTERNOON/EVENING. FAIRLY
SIMILAR TO WHAT OCCURRED YESTERDAY/EARLY THIS MORNING. AND...JUST
LIKE THAT...THE DEPTH OF THE SATURATION IS GOING TO BE A LARGE
FACTOR IN WHAT KIND OF PCPN FALLS. TIME/HEIGHT X-SECTIONS AND BUFKIT
SOUNDINGS KEEP THE SATURATION FROM 800-850 MB TO THE SFC...WITH SOME
MOISTURE ABOVE 500 MB. IN BETWEEN IS RELATIVELY DRY...AND PROBABLY
TOO LARGE TO OVERCOME...AT LEAST INITIALLY...FOR A SEEDER/FEEDER
PROCESS. THIS SUPPORTS DRIZZLE AS THE MAIN PTYPE...WITH A SETUP MUCH
LIKE WHAT OCCURRED TODAY. MIGHT HAVE A BETTER SHOT FOR SHOWERS...AND
PERHAPS SOME ISOLATED THUNDER...AS THE FRONT MOVES INTO EASTERN
WI...BUT LOCALLY...DON/T THINK THIS WILL OCCUR.
MONDAY ALSO LOOKS RELATIVELY WARM WITH 925 MB TEMPS CLIMBING TO
10-14 C AND SREF 850 MB TEMP ANOMALIES OF +2-2.5. THIS HAS ALSO BEEN
A CONSISTENT SIGNAL IN THE MODELS. IT WON/T MIX TO 850 MB...BUT IT
IS INDICATIVE OF THE ABNORMALLY WARM AIR MOVING IN. THAT
SAID...CLOUDS WILL ALSO BE INCREASING AND THICKENING FOR
MONDAY...AND THERE WILL BE THE LIKELIHOOD OF PERIODS OF DRIZZLE.
THESE FACTORS WILL TEMPER JUST HOW WARM IT COULD GET.
.LONG TERM...TUESDAY NIGHT THROUGH SATURDAY
230 AM CST SUN DEC 2 2012
CONSISTENCY REMAINS GOOD BETWEEN THE VARIOUS EXTENDED MODELS WITH
THE OVERALL UPPER LEVEL FLOW/PATTERN FOR MUCH OF THE NEW WORK WEEK.
THE GFS/ECMWF/GEM CONTINUE TO POINT TO AN UPPER LEVEL TROUGH SLIDING
ACROSS SOUTHERN CANADA AT MID WEEK...DRIVING ITS ASSOCIATED SFC
FRONT ACROSS THE UPPER MISSISSIPPI RIVER VALLEY ON THU. THE BETTER
UPPER LEVEL FORCING WILL STAY NORTH...BUT A LOW LEVEL MOISTURE FETCH
ALONG WITH THE FRONT SHOULD BE ENOUGH TO SPARK SOME PRECIPITATION.
COULD SEE SOME PRECIPITATION WED NIGHT AHEAD OF THE FRONT...IN A
REGION OF LOW LEVEL WARM AIR ADVECTION. THE FRONT FROM THU WILL
CONTINUE TO ACT AS A PCPN FOCUS ON FRI/SAT...BUT LOOKS SHIFTED WELL
SOUTH OF THE FORECAST AREA. HOWEVER...THE GFS SUGGESTS THAT A RIPPLE
IN THE UPPER LEVEL FLOW WILL RIDE NORTHEAST ALONG THE
BOUNDARY...AND COULD BRING ANOTHER ROUND OF PCPN TO THE REGION. THE
EC STAYS SOUTH...AND CONSISTENTLY SO. NOT SOLD ON THE GFS AT THIS
TIME...AND WILL SIDE WITH THE EC/CONSENSUS SOLUTION FOR POPS FOR
NOW.
&&
.AVIATION...THROUGH 06Z MONDAY
1110 PM CST SAT DEC 1 2012
A COLD FRONT MOVED THROUGH KRST DURING THE EVENING AND WAS
APPROACHING KLSE AT 05Z. THIS FRONT ALLOWED THE SKIES TO CLEAR AT
KRST AS EXPECTED...BUT LINGERING LOW LEVEL MOISTURE AND LIGHT
WINDS BEHIND THE FRONT HAS ALLOWED FOR IFR VISIBILITIES TO QUICKLY
DEVELOP. AT KLSE...VISIBILITIES REMAIN LOW IN THE LIFR/IFR
CATEGORIES WITH CEILINGS SURPRISINGLY CLIMBING TO MVFR.
ANTICIPATING BOTH KLSE AND KRST TO DEVELOP DENSE FOG EARLY THIS
MORNING WITH VISIBILITIES AND CEILINGS DROPPING TO VLIFR/LIFR.
FAVORABLE CONDITIONS INCLUDE THIS CLEARING GOING ON BEHIND THE
FRONT...THE LIGHT WINDS AND DRY AIR REMAINING VERY FAR OFF TO THE
WEST IN SOUTHWEST MINNESOTA. BOTH SITES SHOULD START TO SEE
IMPROVEMENT AFTER SUNRISE...WITH KLSE TAKING THE LONGEST BECAUSE
OF MOISTURE GETTING STUCK IN THE VALLEY. IN FACT...IT IS ENTIRELY
POSSIBLE THAT STRATUS REMAINS STUCK IN THE VALLEY THROUGH THE
ENTIRE DAY SUNDAY...BUT FOR NOW FOLLOWED THE RAP MODEL WHICH
SUGGESTS SCATTERING OUT AROUND 21Z. KRST SHOULD GO VFR BY NOON
WITH A THINNER STRATUS DECK IN PLACE. VFR CONDITIONS SHOULD BE THE
RULE INTO THE EVENING AS SOUTH WINDS BEGIN TO INCREASE AHEAD OF
DEEPENING LOW PRESSURE IN THE PLAINS. THIS LEADS TO ONE LAST
CONCERN WHICH IS LOW LEVEL WIND SHEAR TOWARDS 06Z MONDAY AND
BEYOND AT BOTH TAF SITES. HAVE NOT INCLUDED THIS CONCERN IN THE
TAF SITES BEING AT THE END OF THE 24 HOUR TAF PERIOD.
LOOKING BEYOND 06Z MONDAY...STRATUS LOOKS LIKELY TO REDEVELOP AT
BOTH TAF SITES AS SOUTHERLY WINDS INCREASE FURTHER AND BRING IN
GULF OF MEXICO MOISTURE AGAIN. CEILINGS OF IFR OR LOWER MAY OCCUR.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
330 AM CST SUN DEC 2 2012
WI...DENSE FOG ADVISORY UNTIL 9 AM CST TODAY FOR WIZ017-029-032>034-
041>044-053>055-061.
MN...DENSE FOG ADVISORY UNTIL 9 AM CST TODAY FOR MNZ079-086>088-
094>096.
IA...DENSE FOG ADVISORY UNTIL 9 AM CST TODAY FOR IAZ008>011-018-019-
029-030.
&&
$$
SHORT TERM...RIECK
LONG TERM....RIECK
AVIATION.....AJ
PREVIOUS FORECAST DISCUSSION ISSUED AT 228 PM...
MAIN FORECAST CONCERN IS WITH THE TEMPERATURES AND RAIN CHANCES
MONDAY.
SURFACE ANALYSIS THIS AFTERNOON SHOWS A COLD FRONT EXTENDING FROM
NORTHWEST MINNESOTA INTO CENTRAL NEBRASKA. A FEW REPORTS ACROSS
EASTERN IOWA OF SOME LIGHT RAIN AND DRIZZLE AHEAD OF THE FRONT
ACROSS EASTERN IOWA.
WATER VAPOR SATELLITE SHOWS A WEAK SHORT WAVE TROUGH ALONG THE
MONTANA/NORTH DAKOTA BORDER. THE 01.12Z MODELS ALL SHOW THIS WAVE
MOVING STRAIGHT EAST ACROSS LAKE SUPERIOR INTO SOUTHERN ONTARIO
TONIGHT. THE BEST PV ADVECTION IN THE 500-300 MB LAYER WILL STAY
TO THE NORTH OF THE AREA TONIGHT AND IS ONLY EXPECTED TO BE
BETWEEN 4 AND 8 PVU/S. THE BEST QG CONVERGENCE IN THE 1000-700 MB
LAYER WILL ALSO PASS BY TO THE NORTH THIS AFTERNOON. THE
ISENTROPIC UP GLIDE ON THE 290K SURFACE WILL BE THE BEST THIS
AFTERNOON AND THEN MOVE OFF TO THE EAST OF THE AREA AFTER 00Z.
WITH THE FORCING BEING THE BEST THIS AFTERNOON...THE INCREASE IN
THE REPORTS OF LIGHT RAIN AND DRIZZLE IS OCCURRING AS
EXPECTED...BUT AS THE FORCING MOVES OFF THE EAST QUICKLY AFTER
00Z...EXPECT TO SEE THE LIGHT PRECIPITATION BE ON THE DECLINE.
HAVE THUS BROUGHT THE PRECIPITATION CHANCES DOWN TO A MAXIMUM OF
40 PERCENT ACROSS THE EAST FOR THIS EVENING WITH ALL OF IT ENDING
BETWEEN 06Z AND 09Z.
SOME CONCERN AS TO WHETHER ANY FOG WILL FORM ACROSS THE WESTERN
SECTIONS OF THE FORECAST AREA TONIGHT. PLENTY OF LOW LEVEL
MOISTURE WILL REMAIN IN PLACE EVEN AFTER THE COLD FRONT MOVES
THROUGH. BY LATE TONIGHT...THE SURFACE WINDS WILL BE DECREASING
BUT THE 01.12Z NAM BUFKIT SOUNDINGS SUGGEST THE POTENTIAL FOR
AROUND 10 KNOTS TO PERSIST JUST ABOVE THE SURFACE AROUND 1K FEET.
VISIBLE SATELLITE SHOWS CLEARING ALONG THE FRONT THAT IS EXPECTED
TO MOVE IN WITH THE FRONT OVERNIGHT. THE CONCERN IS JUST WHEN THE
CLEARING WILL ARRIVE AND IF THERE WILL BE ENOUGH TIME FOR FOG TO
DEVELOP UNDER THE CLEAR SKIES. WILL INCLUDE SOME FOG IN THE
GRIDDED FORECAST BUT WILL NOT GO WITH DENSE FOG AT THIS TIME.
THE NEXT SYSTEM IS SET TO MOVE ACROSS THE UPPER MIDWEST MONDAY.
THIS SYSTEM LOOKS TO BE STRONGER THAN THE WAVE FOR TODAY BUT WILL
ALSO TRACK NORTH WITH THE MAIN WAVE GOING ALONG THE CANADIAN
BORDER. THIS ONCE AGAIN TAKE THE BEST PV ADVECTION IN THE 500-300
MB LAYER WITH BOTH THE NAM AND GFS ONLY SHOWING AROUND 4 PVU/S
COMING ACROSS THE NORTHERN PART OF THE FORECAST AREA. THE QG
CONVERGENCE WITH THIS WAVE LOOKS TO BE WEAK TO MODERATE IN THE
1000-500 MB LAYER WITH 2-3 UBAR/S OF UP GLIDE ON THE 295K LAYER.
THIS SYSTEM LOOKS LIKE IT WILL HAVE THE POTENTIAL TO PRODUCE SOME
LIGHT PRECIPITATION AGAIN BUT LIKE THE LAST TWO SYSTEMS...THE
DEPTH OF SATURATION COMES INTO PLAY. THE FORECAST BUFKIT SOUNDINGS
SHOWS SATURATION UP TO ABOUT 5K FEET WITH PLENTY OF DRY AIR ABOVE
THAT. THE RAISES THE CONCERN OF WHETHER THE PRECIPITATION TYPE
WILL BE LIGHT RAIN OR DRIZZLE. PLAN TO INTRODUCE DRIZZLE AND CARRY
BOTH TYPES FOR NOW. ALSO CONCERNED ABOUT TEMPERATURES AHEAD OF
THIS SYSTEM. FORECAST SOUNDINGS SHOW THE WARMEST AIR ALOFT WILL
RESIDE BETWEEN 900 AND 800 MB AND THAT THE LOW LEVEL INVERSION
BELOW THIS NEVER MIXES OUT ALLOWING THE WARM AIR TO BE TAPPED
INTO. ALSO...AS THE LOW LEVEL MOISTURE RETURNS AHEAD OF THIS
SYSTEM...THE LOW LEVELS UNDER THE INVERSION BECOME SATURATED WHICH
COULD BE SETTING THE AREA UP FOR ANOTHER DAY OF FOG AND LOW
CLOUDS. IF THIS OCCURS...VERY LIMITED TEMPERATURE RISES WOULD BE
EXPECTED AND COULD KEEP THE HIGHS ANYWHERE FROM 5 TO 10 DEGREES
UNDER THE FORECAST TEMPERATURES. STARTED TO TREND TOWARD THIS WILL
A SLIGHT DOWNWARD NUDGE IN THE TEMPERATURES.
.LONG TERM...TUESDAY THROUGH SATURDAY
228 PM CST SAT DEC 1 2012
LITTLE OVERALL CHANGE IN THE PATTERN IS EXPECTED TO OCCUR WITH A
ZONAL TO WEAK NORTHWEST FLOW BRINGING IN NORTHERN STREAM SYSTEMS.
THE EXTENDED MODELS ARE IN GOOD AGREEMENT THAT THE NEXT SHORT WAVE
TROUGH IN THIS FLOW PATTERN WILL TRACK ACROSS SOUTHERN CANADA AND
THE UPPER MIDWEST WEDNESDAY NIGHT AND THURSDAY. THIS SYSTEM WILL
PUSH ANOTHER COLD FRONT THROUGH THE REGION WITH LIGHT
PRECIPITATION POSSIBLE ALONG AND AHEAD OF THE FRONT. SOME SLIGHT
DIFFERENCES ON HOW LONG THE PRECIPITATION WILL LINGER WITH MOST
MODELS ENDING IT LATE THURSDAY OR THURSDAY EVENING. THE REST OF
THE PERIOD LOOKS TO BE DRY AT THIS POINT AS HIGH PRESSURE BUILDS
IN AT THE SURFACE.
&&
.AVIATION...THROUGH 06Z MONDAY
1110 PM CST SAT DEC 1 2012
A COLD FRONT MOVED THROUGH KRST DURING THE EVENING AND WAS
APPROACHING KLSE AT 05Z. THIS FRONT ALLOWED THE SKIES TO CLEAR AT
KRST AS EXPECTED...BUT LINGERING LOW LEVEL MOISTURE AND LIGHT
WINDS BEHIND THE FRONT HAS ALLOWED FOR IFR VISIBILITIES TO QUICKLY
DEVELOP. AT KLSE...VISIBILITIES REMAIN LOW IN THE LIFR/IFR
CATEGORIES WITH CEILINGS SURPRISINGLY CLIMBING TO MVFR.
ANTICIPATING BOTH KLSE AND KRST TO DEVELOP DENSE FOG EARLY THIS
MORNING WITH VISIBILITIES AND CEILINGS DROPPING TO VLIFR/LIFR.
FAVORABLE CONDITIONS INCLUDE THIS CLEARING GOING ON BEHIND THE
FRONT...THE LIGHT WINDS AND DRY AIR REMAINING VERY FAR OFF TO THE
WEST IN SOUTHWEST MINNESOTA. BOTH SITES SHOULD START TO SEE
IMPROVEMENT AFTER SUNRISE...WITH KLSE TAKING THE LONGEST BECAUSE
OF MOISTURE GETTING STUCK IN THE VALLEY. IN FACT...IT IS ENTIRELY
POSSIBLE THAT STRATUS REMAINS STUCK IN THE VALLEY THROUGH THE
ENTIRE DAY SUNDAY...BUT FOR NOW FOLLOWED THE RAP MODEL WHICH
SUGGESTS SCATTERING OUT AROUND 21Z. KRST SHOULD GO VFR BY NOON
WITH A THINNER STRATUS DECK IN PLACE. VFR CONDITIONS SHOULD BE THE
RULE INTO THE EVENING AS SOUTH WINDS BEGIN TO INCREASE AHEAD OF
DEEPENING LOW PRESSURE IN THE PLAINS. THIS LEADS TO ONE LAST
CONCERN WHICH IS LOW LEVEL WIND SHEAR TOWARDS 06Z MONDAY AND
BEYOND AT BOTH TAF SITES. HAVE NOT INCLUDED THIS CONCERN IN THE
TAF SITES BEING AT THE END OF THE 24 HOUR TAF PERIOD.
LOOKING BEYOND 06Z MONDAY...STRATUS LOOKS LIKELY TO REDEVELOP AT
BOTH TAF SITES AS SOUTHERLY WINDS INCREASE FURTHER AND BRING IN
GULF OF MEXICO MOISTURE AGAIN. CEILINGS OF IFR OR LOWER MAY OCCUR.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
1035 PM CST SAT DEC 1 2012
WI...DENSE FOG ADVISORY UNTIL 9 AM CST SUNDAY FOR WIZ017-029-032>034-
041>044-053>055-061.
MN...DENSE FOG ADVISORY UNTIL 9 AM CST SUNDAY FOR MNZ079-086>088-
094>096.
IA...DENSE FOG ADVISORY UNTIL 9 AM CST SUNDAY FOR IAZ008>011-018-019-
029-030.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION...AJ
AREA FORECAST DISCUSSION...CORRECTED
NWS TAMPA BAY RUSKIN FL
315 AM EST TUE DEC 4 2012
.SYNOPSIS...
08Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS AN AMPLIFYING UPPER LEVEL
PATTERN OVER THE CONUS THIS MORNING. NORTHERN STREAM FLOW CONSISTS
OF LONGWAVE RIDGING OVER THE PACIFIC COAST FOLLOWED DOWNSTREAM BY A
BROAD LONGWAVE TROUGH ACROSS THE MID-SECTION OF THE CONTINENT. THE
FLOW THEN FINALLY TURNS BACK TO THE NORTHEAST INTO LONGWAVE RIDGING
IN PLACE OVER THE EASTERN SEABOARD/WESTERN ATLANTIC. OUR FORECAST
AREA RESIDES AT THE BASE OF THIS RIDGE UNDER 582-584DM HEIGHTS. THE
PRESENCE AND INFLUENCE OF THIS UPPER RIDGING CAN AGAIN BE SEEN QUITE
WELL ON THE 04/00Z KTBW SOUNDING PROFILE WHICH SHOWS A WELL-DEFINED
SUBSIDENCE INVERSION AT 800MB. ANY SIGNIFICANT COLUMN MOISTURE IS
SUPPRESSED BENEATH THIS FEATURE.
AT THE SURFACE...1025MB HIGH PRESSURE REMAINS CENTERED OFF THE
CAROLINA COAST WITH A RIDGE AXIS EXTENDING BACK TO THE WEST THROUGH
SOUTHERN/CENTRAL GA/AL. GRADIENT FLOW ON THE SOUTHERN SIDE OF THIS
RIDGE AXIS IS PROVIDING AN EASTERLY BOUNDARY LAYER WIND AND AN
INFLUX OF ATLANTIC MOISTURE. DEEP LAYER SUPPRESSION IS CURRENTLY
STRONG ENOUGH THAT UNLIKE PREVIOUS NIGHTS...WE ARE NOT SEEING ANY
ISOLATED SPEED CONVERGENCE SHOWERS MIGRATING WESTWARD FROM THE FL
EAST COAST. THERE ARE STILL PERIODS OF LOWER STRATOCU MOVING EAST TO
WEST...ESPECIALLY DOWN TOWARD FT MYERS...AND THESE PERIODIC CLOUDS
WILL BE AROUND THROUGH THE DAY. TEMPERATURES ARE SEASONABLY WARM
WITH MOST LOCATIONS REPORTING IN THE 50S NORTH AND UPPER 50S TO
LOWER 60S SOUTH.
&&
.SHORT TERM (TODAY THROUGH THURSDAY)...
TODAY/TONIGHT...STACKED RIDGING WILL REMAIN THE DOMINANT PLAYER IN
OUR FORECAST THROUGH THE DAY. SHORTWAVE ENERGY WILL BEGIN TO
APPROACH THE REGION ALONG THE NORTHERN GULF COAST LATE IN THE
DAY...BUT THIS FEATURE SHOULD HAVE LITTLE IMPACT ON THE RIDGE UNTIL
VERY LATE TONIGHT AND WEDNESDAY. AT LEAST FOR TODAY...WILL START THE
DAY OFF WITH SOME PATCHY FOG...ESPECIALLY NORTH OF THE I-4 CORRIDOR.
THE LARGE SCALE SUPPRESSION AND DECENT DIURNAL MIXING WILL RESULT IN
ANOTHER WARM DAY REGION-WIDE WITH AFTERNOON HIGH TEMPERATURES IN THE
MIDDLE 70S TO AROUND 80 UNDER A MIX OF SUN AND CLOUDS. WILL BEGIN TO
SEE A SLOW BREAKDOWN IN HEIGHTS OVERNIGHT AS THE SHORTWAVE CONTINUES
IT EASTWARD ADVANCE TOWARD THE REGION. HOWEVER...PLENTY OF RESIDUAL
DRY AIR IN THE COLUMN WILL KEEP ANY MENTION OF RAIN OUT OF THE
FORECAST.
WEDNESDAY...MID/UPPER LEVEL FLOW BECOMES INCREASINGLY CYCLONIC IN
NATURE OVER THE FL PENINSULA THROUGH THE DAY. IN THE LOWER LEVELS
WILL CONTINUE TO SEE A GENERAL EASTERLY FLOW ON THE SOUTH SIDE OF
THE SURFACE RIDGE. A SLOW INCREASE IN SYNOPTIC SUPPORT FOR LIFT AND
COLUMN MOISTURE ALONG WITH THE FAVORED EASTERLY FLOW SHOULD INITIATE
THE DEVELOPMENT OF EAST COAST SPEED CONVERGENCE SHOWERS THAT THEN
TRANSLATE WESTWARD TOWARD THE REGION. THE MAJORITY OF THIS ACTIVITY
WILL LIKELY REMAIN ON THE EASTERN SIDE OF THE PENINSULA...BUT FEEL
THE SETUP IS FINALLY GOOD ENOUGH TO RE-INTRODUCE A SLIGHT CHANCE FOR
ISOLATED SHOWERS ACROSS MANY OF OUR ZONES. ANY SHOWERS THAT DO
OCCUR...ARE LIKELY TO BE LIGHT AND BRIEF IN NATURE. WILL SEE MORE IN
THE WAY OF CLOUDS FOR WEDNESDAY...BUT STILL ENOUGH SUNNY BREAKS TO
ALLOW FOR TEMPS TO REACH THE MID/UPPER 70S.
WEDNESDAY NIGHT/THURSDAY...THE SETUP NOW APPEARS MORE FAVORABLE FOR
SCT SHOWERS WITH THE SHORTWAVE PASSAGE THAN DURING PREVIOUS FORECAST
CYCLES...ESPECIALLY OVER THE SOUTHERN HALF OF THE AREA. FAIRLY
SHARP SHORTWAVE WILL APPROACH THE FL WEST COAST WEDNESDAY NIGHT AND
THEN CROSS OVER THE AREA DURING THE DAYLIGHT HOURS OF THURSDAY.
DECENT SWATH OF DEEP LAYER QG FORCING/SYNOPTIC SUPPORT OVERSPREADS
THE AREA THROUGH THURSDAY MORNING. IT ALSO NOW APPEARS THAT MORE IN
THE WAY OF COLUMN MOISTURE WILL BE COINCIDENT WITH THIS LIFT. ALL
THIS COMBINED WITH A STRENGTHENING EASTERLY FLOW SHOULD SUPPORT EAST
TO WEST FAST MOVING SHOWERS. WILL KEEP THIS ACTIVITY ISOLATED IN
NATURE FROM TAMPA BAY NORTHWARD ALONG THE NATURE COAST FOR NOW...BUT
INCREASING POPS TO CHANCE/SCATTERED RANGE FURTHER SOUTH IN LINE WITH
THE BEST Q-VECTOR CONVERGENCE AND DEEP LAYER MOISTURE. THURSDAY
AFTERNOON/EVENING WILL SEE THE SHORTWAVE AXIS AND RESULTING LIFT
PASSING THE AREA. INCREASING DEEP LAYER SUPPRESSION AND DRYING IN
THE WAKE OF THIS AXIS SHOULD END MOST OF THE SHOWER ACTIVITY OVER
THE FL WEST COAST BY THURSDAY NIGHT.
&&
.LONG TERM (FRIDAY THROUGH NEXT MONDAY)...
POTENT SHORT WAVE TROUGH WILL MOVE EAST OF THE AREA THURSDAY NIGHT
WITH CLEARING SKIES IN ITS WAKE. A LARGE AREA OF HIGH PRESSURE WILL
BRIDGE ACROSS A DECAYING FRONTAL BOUNDARY TO OUR NORTH. THERE WILL
BE NO REAL AIRMASS CHANGE SO WE WILL SEE LITTLE IF ANY CHANGE IN OUR
TEMPERATURES AND HUMIDITIES THROUGH THE EXTENDED PERIOD.
MODELS SHOW ENOUGH MOISTURE IN THE LOW LEVELS OF THE ATMOSPHERE TO
SUPPORT AT LEAST A SLIGHT CHANCE OF SHOWERS EACH DAY FROM SATURDAY
THROUGH MONDAY. THERE ARE NO SIGNIFICANT COLD FRONTS THROUGH AT
LEAST MONDAY...BUT SOME MODELS SUGGEST THE POSSIBILITY OF A WEAK
FRONTAL PASSAGE ON TUESDAY.
TEMPERATURES ARE LIKELY TO RUN SEVERAL DEGREES ABOVE NORMAL THROUGH
THE PERIOD...ESPECIALLY THE AFTERNOON HIGHS.
&&
.AVIATION...
SOME BRIEF PATCHY FOG POSSIBLE AROUND SUNRISE TODAY...OTHERWISE JUST
VFR CONDITIONS EXPECTED NEXT 24 HOURS.
&&
.MARINE...
HIGH PRESSURE TO THE NORTH OF THE AREA WILL CONTINUE AN EASTERLY
FLOW REGIME OVER THE EASTERN GULF OF MEXICO TODAY. NEAR CAUTIONARY
LEVEL WINDS OVER THE OFFSHORE WATERS EARLY THIS MORNING WILL
DIMINISH BY AFTERNOON. ANOTHER BRIEF SURGE IN WINDS TO NEAR
CAUTIONARY LEVELS IS POSSIBLE TONIGHT...ESPECIALLY SOUTH OF TAMPA
BAY. WINDS ARE FORECAST WELL BELOW HEADLINE CRITERIA DURING THE
MIDDLE PORTION OF THE WEEK AS THE LOCAL GRADIENT RELAXES. HIGH
PRESSURE WILL THEN BUILD ONCE AGAIN TO OUR NORTH FOR THE END OF THE
WEEK KEEPING AN EASTERLY FLOW REGIME IN PLACE.
&&
FIRE WEATHER...
SURFACE HIGH PRESSURE TO THE NORTH OF THE AREA WILL PROVIDE AN
EASTERLY FLOW AND ABUNDANT LOW LEVEL ATLANTIC MOISTURE THROUGH
WEDNESDAY. A COLD FRONT WILL APPROACH FROM THE NORTHWEST WEDNESDAY
AND WEDNESDAY NIGHT...BUT IS NOW EXPECTED TO DISSIPATE BEFORE
REACHING THE FL PENINSULA. A FEW SHOWERS ARE POSSIBLE WEDNESDAY INTO
THURSDAY ASSOCIATED WITH THIS SYSTEM...BUT NO SIGNIFICANT RAINFALL
IS FORECAST. HIGH PRESSURE WILL ONCE AGAIN BUILD TO OUR NORTH FOR
THE END OF THE WEEK. NO SIGNIFICANT FIRE WEATHER CONCERNS ARE
ANTICIPATED.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 79 61 77 60 / 0 0 20 20
FMY 79 61 78 61 / 10 10 20 30
GIF 79 57 79 58 / 0 10 20 20
SRQ 78 59 77 60 / 0 0 20 30
BKV 80 51 78 54 / 0 0 20 20
SPG 76 63 76 63 / 0 0 20 20
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/MARINE/FIRE WX...MROCZKA
LONG TERM/AVIATION...JILLSON
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
330 AM EST TUE DEC 4 2012
.DISCUSSION...
TODAY...PERSISTENCE FCST WILL BE THE GENERAL RULE AS A LARGE
H100-H70 ANTICYCLONE BLANKETING THE ERN SEABOARD CONTINUES TO
DOMINATE THE LCL WX PATTERN. CIRCULATION CENTERED OFF THE CAROLINA
COAST...DEEP ERLY FLOW TO CONTINUE. MAX TEMPS M-U70S
COAST...U70S/L80S INTERIOR.
LATEST SAT PICS/RAP ANALYSIS SHOWING A POCKET OF LOW LVL MOISTURE NE
OF THE NRN BAHAMAS EMBEDDED WITHIN THE ERLY FLOW...H100-H85 MEAN RH
ABV 80PCT...H100-H70 RH AOA 60PCT. AS THIS POCKET PUSHES ACRS THE
ISLANDS...EXPECT TO SEE A FEW SHRA BANDS DVLP IN THE CONVERGENT
EDDYS ON THEIR LEE SIDE. THESE SHOULD BE SUSTAINED BY THE WARM GULF
STREAM WATERS...WHILE THE STRENGTH/DEPTH OF THE LOW LVL ERLY FLOW
WOULD PUSH THEM ONSHORE S OF SEBASTIAN INLET. IMPACT WILL BE MINIMAL
AS THE LCL SOUNDINGS SHOW A SHARP H85-H70 SUBSIDENCE INVERSION
ASSOCD WITH THE RIDGE THAT WILL LIMIT VERTICAL MOTION BLO 10KFT
WHILE RAP ANALYSIS SHOWS LITTLE IN THE WAY OF MID/UPR LVL DYNAMIC
SUPPORT.
TONIGHT...THE RIDGE AXIS WILL BE SHUNTED E/SE THRU DAYBREAK WED AS A
FRONTAL TROF EXTENDING FROM THE GREAT LAKES TO THE SRN PLAINS PUSHES
TOWARD THE APPALACHIAN RANGE. H100-H70 WINDS WILL RESPOND BY VEERING
TO THE SE WHICH SHOULD ALLOW SHRAS TO SPREAD INTO SRN BREVARD/SERN
OSCEOLA...BUT AGAIN WITH MINIMAL IMPACT. INCREASED CLOUDS AND
INCREASING SRLY WIND COMPONENT SHOULD KEEP MIN TEMPS IN THE
U50S/L60S INTERIOR...L/M60S ALONG THE COAST.
WED-FRI...HIGH PRESSURE WILL WEAKEN AND MOVE EAST WEDNESDAY AHEAD
OF APPROACHING SHORTWAVE. ASSOCIATED SURFACE FRONT WILL WASH OUT TO
THE NORTH OF FLORIDA. HIGH PRESSURE TO THE NORTH WILL BRIDGE THE
REMAINS OF THE BOUNDARY THROUGH THE LATE WEEK. SOME INCREASE IN LOW
LEVEL MOISTURE AND TROFINESS ALOFT SHOULD ALLOW A FEW SHOWERS DURING
THIS TIME FRAME. HAVE LOW POPS MENTIONED WITH VALUES A LITTLE HIGHER
SOUTHERN COASTAL SECTIONS BY THURS NIGHT FRI WITH DEEPER MOISTURE
AND SOME CONVERGENCE DUE TO INVERTED TROF SETTING UP. TEMPS WILL BE
ON THE WARM SIDE FOR EARLY DEC WITH HIGHS MID/UPPER 70S...A FEW
SPOTS TOPPING 80 SOUTHERN INTERIOR. OVERNIGHT MINS RANGING FROM THE
MID/UPPER 50S WELL INLAND/VOLUSIA TO NEAR 60/LOWER 60S ALONG THE
COAST SOUTH OF THE CAPE.
SAT-MON...WILL CONTINUE WITH ABOVE NORMAL TEMPS THIS WEEKEND AS HIGH
TO THE NORTH SLIDES EAST OVER THE ATLANTIC AND LOW LEVEL FLOW VEERS
TO A MORE SE-S COMPONENT. SLIGHT CHANCE FOR SHOWERS WITH LINGERING
MOISTURE...WILL KEEP AS SLIGHT CHANCE/ISOLATED FOR NOW.
&&
.AVIATION...PREVAILING VFR ALL SITES UNLESS OTHERWISE NOTED. THRU
04/15Z...PTCHY MVFR VSBYS IN BR W OF KDAB-KOBE...BRIEF PDS OF IFR
VSBYS N OF I-4. BTWN 04/15Z-05/00Z...LCL MVFR CIGS/VSBYS IN ISOLD
PASSING SHRAS S OF KMLB-KGIF...LINE SHIFTING N TO KTIX-KISM AFT
15/00Z.
&&
.MARINE...TODAY-TONIGHT...HI PRES RIDGE CENTERED OFF THE CAROLINA
COAST WILL MAINTAIN A GENTLE TO MODERATE E/SE BREEZE ACRS THE LCL
ATLC THRU DAYBREAK WED. LATEST BUOY OBS SHOW THE SWELL IMPACTING THE
E FL COAST HAS SUBSIDED TO ARND 4FT WHICH THE CURRENT ERLY FLOW
SHOULD BE ABLE TO MAINTAIN. STEADY STATE CONDITIONS WITH SEAS 3-5FT
NEARSHORE AND 4-6FT OFFSHORE. WHILE THE LATTER MIGHT WARRANT A
CAUTIONARY STATEMENT...ALL OF THE OFFSHORE BUOYS ARE INDICATING THE
SEAS ARE MAINLY COMPRISED OF A LONG PD SWELL BTWN 8-10SEC WITH
SUSTAINED SFC WNDS GENERALLY BLO 15KTS. WILL HOLD OFF ON ANY
STATEMENTS.
WED-SAT...ONSHORE FLOW WILL PERSIST INTO THE WEEKEND. SEAS WILL
GENERALLY BE 3-5 FT...A FEW SPOTS UP TO 6 FEET WELL OFFSHORE. A FEW
SHOWERS WILL PERSIST FROM MID WEEK INTO THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 76 62 75 60 / 0 10 20 20
MCO 81 61 79 59 / 0 10 20 20
MLB 77 64 76 62 / 10 20 20 20
VRB 78 63 77 62 / 20 20 20 20
LEE 81 59 78 58 / 0 10 20 20
SFB 80 61 78 59 / 0 10 20 20
ORL 81 61 78 59 / 0 10 20 20
FPR 78 63 77 62 / 20 20 20 30
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...BRAGAW
LONG TERM....GLITTO
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1120 PM CST MON DEC 3 2012
.AVIATION...
A COLD FRONT IS NOW WELL EAST OF ALL TERMINAL SITES IN EASTERN
IOWA AND NORTHWEST ILLINOIS. WINDS ARE NOW NORTHWESTERLY AROUND 8
TO 10 KTS...AND WILL REMAIN NEAR THAT RANGE THROUGH SUNSET TUESDAY
AFTERNOON. A HIGH CIRRUS OVERCAST REMAINS IN PLACE THROUGH THE
OVERNIGHT HOURS...BUT SHOULD BECOME TOTALLY CLEAR AT ALL SITES
EARLY TUESDAY MORNING. VISIBILITIES WILL BE EXCELLENT ABOVE 10
MILES...THROUGH THE PERIOD...AND BEYOND.
ERVIN
&&
.PREV DISCUSSION... /ISSUED 507 PM CST MON DEC 3 2012/
UPDATE...
A FORECAST UPDATE WAS SENT EARLY THIS PAST HOUR TO REFLECT A MUCH
LESS COVERAGE OF SHOWERS AND SHALLOW THUNDERSTORMS/CONVECTION. THE
EAST REMAINS THE MOST LIKELY AREA TO RECEIVE MEASURABLE RAIN...BUT
LOCATIONS WEST OF PRINCETON TO STERLING ARE LIKELY TO REMAIN WITH
TRACE AMOUNTS. AS FAR AS STRONG STORMS...WINDS ARE VEERING TO THE
SOUTHWEST...REDUCING SHEAR AT LOW LEVELS...THIS IS TRUE EXCEPT FOR
BUREAU AND PUTNAM COUNTIES...BUT BY THE TIME STORMS REACH
THERE...THEY MAY VEER AS WELL. WE REMAIN WATCH FULL...BUT FEEL THE
THREAT FOR A SEVERE EVENT IS VERY LOW AND CONFINED TO THE NEXT 1
HOUR...IN THE FAR EAST.
ERVIN
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
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.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
306 AM EST TUE DEC 4 2012
.SYNOPSIS...
ISSUED AT 306 AM EST TUE DEC 4 2012
A BROKEN LINE OF SHOWERS AHEAD OF A COLD FRONT IS MOVING ACROSS
LOWER MICHGIAN EARLY THIS MORNING. THE RAIN WILL MOVE OUT OF THE
AREA BY LATE MORNING. WE/LL SEE SOME SUNSHINE THIS AFTERNOON BUT
TEMPERATURES WILL BE MUCH COOLER THAN YESTERDAY. THERE IS A CHANCE
OF MIXED RAIN AND SNOW FROM THURSDAY THROUGH THE WEEKEND.
TEMPERATURES WILL BE NEAR NORMAL.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 306 AM EST TUE DEC 4 2012
FORECAST CONCERNS DEAL PCPN TRENDS THIS MORNING. OVERALL...THE
FORECAST HASN/T CHANGED MUCH.
REGIONAL RADAR SHOWS A BROKEN BAND OF SHOWERS STRETCHING FROM NRN
LAKE HURON SWWD TO NEAR ST LOUIS. THIS PCPN IS ALIGNED ALONG THE
COLD FRONT WHICH IS PUSHING THROUGH THE CWA ATTM. LATEST IR LOOP
SHOWS COOLING CLOUD TOPS OVER ILLINOIS. THIS IS LIKELY IN RESPONSE
TO A WAVE ON THE SRN PORTION OF THE FRONT. HRRR SUGGESTS WE/LL SEE A
LARGER AREA OF PCPN MOVE INTO THE SRN/SE CWA PRIOR TO SUNRISE AS THE
WAVE MOVES NEWD. THIS JUST APPEARS TO BE RAIN...LIGHTNING REMAINS
WELL SW OF THE GREAT LAKES. PCPN WILL END FROM NW TO SE THIS
AFTERNOON AS THE WAVE MOVES MOVES THROUGH.
A SECONDARY COLD FRONT WILL MOVE SEWD THROUGH LOWER MICHIGAN
TONIGHT. WE MAY BRIEFLY SEE A FEW SHSN DEVELOP ALONG THE LAKE SHORE
NORTH OF HOLLAND BUT THEY WON/T AMOUNT TO MUCH AND WILL QUICKLY FADE
BY WEDNESDAY MORNING AS CORE OF THE COLD AIR MOVES EAST. HIGH
PRESSURE WILL SETTLE OVER THE CWA WEDNESDAY.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 306 AM EST TUE DEC 4 2012
HALLENGING FORECAST IN THE EXTENDED AS MODEL CONSISTENCY HAS
BEEN POOR THE LAST COUPLE DAYS HANDLING THE DETAILS OF AN INVERTED
TROUGH/SFC WAVE MOVING ALONG THE FRONT STALLED ACROSS THE OHIO
VALLEY...AND A MORE SIGNIFICANT STORM EARLY NEXT WEEK.
WENT WITH LOW CHANCE OR SLIGHT CHANCE POPS EARLY IN THE PERIOD WITH
LOW CONFIDENCE ON DETAILS OF WHEN AND WHERE BEST CHANCES FOR PRECIP
WITH BE. P-TYPE IS ALSO A TOUGH CALL AS THERMAL PROFILES SUGGEST MIX
NORTH AND RAIN SOUTH.
A HIGHER IMPACT EVENT IS EXPECTED NEXT WEEK AS STRONG UPPER TROUGH
MOVES INTO THE ROCKIES WITH SFC LOW FORMING OVER THE PLAINS AND
HEADING FOR LOWER MICHIGAN. AGAIN CONFIDENCE IS LOW ON TIMING DUE TO
MODEL DIFFERENCES AND INCONSISTENCY...BUT A MIXED PRECIP TO RAIN
THEN OVER TO SNOW SCENARIO IS POSSIBLE EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1137 PM EST MON DEC 3 2012
MVFR CIGS / VSBY WITH SHOWERS WILL ACCOMPANY THE COLD FRONT AS IT
MOVES THROUGH THE TAF SITES DURING THE EARLY MORNING HOURS OF
TUESDAY. SO FAR THIS EVENING MOST OF THE RAIN HAS BEEN NORTH OF
I-96. THERE IS ANOTHER SHORTWAVE (SEEN ON WATER VAPOR LOOPS) OVER
KS THIS EVENING. THIS WILL TRAVEL UP THE FRONT TUESDAY AND MAY
PROGLONG THE RAIN OVER JXN/LAN TAF SITES DURING THE MID MORNING
HOURS OF TUESDAY. COLDER DRIER AIR WILL FOLLOW THE FRONT EVEN SO
TUESDAY. THE RESULTS SHOULD BE CLEARING OF THE LOW CLOUDS BY MID
MORNING AND MID CLOUDS BY MID AFTERNOON.
&&
.MARINE...
ISSUED AT 306 AM EST TUE DEC 4 2012
COLD ADVECTION WILL INCREASE WAVE HEIGHTS TODAY INTO WEDNESDAY. WE
EXTENDED THE SCA THROUGH THE AFTERNOON WEDNESDAY.
&&
.HYDROLOGY...
ISSUED AT 306 AM EST TUE DEC 4 2012
NO HYDRO ISSUES THIS MORNING QPF LESS THAN A QUARTER INCH IS
EXPECTED FROM SHOWERS ALONG THE COLD FRONT THIS MORNING.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 5 PM EST WEDNESDAY FOR LMZ844>849.
&&
$$
SYNOPSIS...93
SHORT TERM...93
LONG TERM...OSTUNO
AVIATION...WDM
HYDROLOGY...93
MARINE...93
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1226 AM EST TUE DEC 4 2012
.SYNOPSIS...
MILD TEMPERATURES WILL CONTINUE AHEAD OF A COLD FRONT...EXPECTED TO
CROSS THE EASTERN CAROLINAS ON WEDNESDAY. SCATTERED SHOWERS WILL
ACCOMPANY THE FRONT. COOLER CONDITIONS ARE EXPECTED AS HIGH PRESSURE
BUILDS OVER THE REGION THURSDAY AND FRIDAY...WITH MODERATING
TEMPERATURES NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 12:30 AM TUESDAY...AREAS OF FOG...SOME DENSE SPOTS
INCLUDED...NOW FORMING. STILL A GOOD POSSIBILITY THAT WE WILL BE
ISSUING A DENSE FOG ADVISORY EARLY THIS MORNING. PREVIOUS
DISCUSSION FOLLOWS:
THE BROAD CENTER OF 1026 MB HIGH PRESSURE IS LOCATED MAYBE A
HUNDRED MILES OFFSHORE...BUT A ZONE OF VERY WEAK PRESSURE GRADIENT
EXTENDS AS FAR WEST AS GEORGIA. ALTHOUGH SURFACE WINDS ARE VERY
LIGHT OR CALM THERE IS A LITTLE BETTER RETURN FLOW ABOVE THE
SURFACE IN THE 1000-2000 FT AGL LAYER...ABOUT 10-12 KNOTS.
ALTHOUGH NOT AS WIDESPREAD AS LAST NIGHT...SATELLITE IMAGERY
REVEALS AN AREA OF ALTOCUMULUS ALONG THE SOUTH CAROLINA COAST WITH
BASES IN THE 7000-8000 FT RANGE. THIS CLOUD COVER APPEARS TO BE
RELATED TO MOISTURE TRAPPED UNDERNEATH THE SUBSIDENCE INVERSION
ALOFT AND SOME WEAK LIFT ALONG THE UPWARD- SLOPING 295K TO 300K
ISENTROPIC SURFACES. WHILE I WOULD LIKE TO SAY THESE CLOUDS WILL
NOT BE WITH US MUCH LONGER...NAM AND RUC MODELS SHOW CONTINUED
MOISTURE AND WEAK LIFT WHICH MAY SUPPORT SOME CLOUDS ALONG THE
COAST THROUGH DAYBREAK.
THE AMOUNT OF CLOUD COVER IS CRITICALLY IMPORTANT TONIGHT SINCE
BOUNDARY LAYER MOISTURE IS VERY RICH BY DECEMBER STANDARDS...AND
JUST A FEW HOURS OF CLEAR SKIES AND CALM WINDS SHOULD YIELD
WIDESPREAD FOG. MUCH LIKE WE SAW LAST NIGHT THE FOG COULD BECOME
DENSE WITH VISIBILITIES DROPPING BELOW 1/4 MILE AT TIMES. GIVEN
UNCERTAINTIES IN THE TIMING AND LOCATION OF ANY DENSE FOG WE WILL
NOT ISSUE A DENSE FOG ADVISORY AT THIS TIME...BUT ONE MAY BE NEEDED
IN THE NEXT 4-6 HOURS.
VERY LITTLE CHANGES ARE NEEDED TO THE REMAINDER OF THE
FORECAST...WITH LOWS STILL EXPECTED TO FALL INTO THE UPPER 40S TO
AROUND 50.
&&
.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY...HIGH PRESSURE ON TUESDAY WILL GIVE WAY TO A
QUICK MOVING FRONT ON WEDNESDAY NIGHT INTO EARLY THURSDAY MORNING.
THE BEST DYNAMICS WILL REMAIN NORTH OF VIRGINIA AND ISENTROPIC
FLOW SHOWS SOME UPWARD VERTICAL MOTION BUT IT IS NOT THAT
IMPRESSIVE IN THE LAYER`S AT BELOW 300 KELVIN. SO EXPECT SCATTERED
SHOWERS WITH LOW QPF VALUES.
MAXIMUM TEMPERATURES ARE EXPECTED TO REMAIN IN THE LOWER TO MID
70S FOR TUESDAY AND UPPER 60S ON WEDNESDAY. LOW TEMPERATURES ARE
EXPECTED TO BE IN THE MID 50S TUESDAY AND WITH THE COLD AIR
ADVECTION BEHIND THE FRONT TEMPERATURES SHOULD DROP INTO THE LOWER
TO MID 40S.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 3 PM MONDAY...MEDIUM RANGE GUIDANCE CONTINUES TO TREND
TOWARD A MILDER AND DRIER SCENARIO FOR THE EXTENDED. INITIALLY A
ZONAL FLOW ALOFT PREVAILS THEN A POTENT SHORTWAVE DIVES INTO THE
EASTERN SLOPES OF THE ROCKIES ALLOWING A SIGNIFICANT RIDGE TO
DEVELOP OFF OF THE SOUTHEAST COAST. CONTINUED TO TREND POPS DOWN
THROUGH THE PERIOD FOLLOWING HPC AS BERMUDA HIGH PRESSURE WILL BE
THE DOMINANT FEATURE FOR OUR AREA. SLIGHT CHANCE POPS REMAIN FOR
MONDAY FOR GENERAL CONVECTION OF ALL THINGS AS SOUNDINGS ARE
SHOWING CAPE VALUES NEAR 500 J/KG. TOUGH TO FIND FORCING OTHER
THAN MESOSCALE FEATURES SUCH AS THE SEA BREEZE AND DIFFERENTIAL
HEATING. SEA FOG REMAINS A POSSIBILITY WITH A QUICK CHECK OF
SURFACE DEWPOINTS IN THE MID TO UPPER 60S SUNDAY...AND RELATIVELY
LIGHT WINDS.
TEMPERATURES WILL BE A BIG STORY AS WELL AS POPS ARE OUT OF THE
FORECAST AND WITH 850MB TEMPERATURES SLIGHTLY WARMER THAN WE HAVE
CURRENTLY...A COUPLE OF DAYS IN THE 70S APPEARS TO BE A GOOD BET.
THESE WILL OCCUR SUNDAY AND MONDAY. LEADING UP TO THIS...MORE
SEASONAL VALUES CAN BE EXPECTED.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 06Z...EXPECT MVFR/IFR...WITH POSSIBLE LIFR...DUE TO FOG
OVERNIGHT AND INTO TUESDAY MORNING.
NEARLY CLEAR SKIES AND LIGHT WINDS ARE ALLOWING FOR AN IDEAL
RADIATIONAL COOLING CONDITIONS TO ALREADY SET UP ACROSS THE AREA.
LATEST TIME-HEIGHT ANALYSIS AND FCST SOUNDINGS CONTINUE TO DEPICT
THAT SUFFICIENT LOW LEVEL MOISTURE IS SPREAD ACROSS MOST OF THE AREA
DUE TO CONTINUED ONSHORE FLOW. WITH THE ANTICIPATION OF CALM
WINDS...EXPECT IFR TO MVFR DUE TO REDUCED VISIBILITIES TO
CONTINUE. ANTICIPATE CONDITIONS TO DETERIORATE LOWER TO LIFR DUE
TO FOG...WITH THE POTENTIAL FOR LOWERED CIGS AROUND 200FT.
RESTRICTIONS WILL LIKELY PERSIST AFTER DAYBREAK...WITH CONDITIONS
IMPROVING TO VFR BY LATE MORNING AND LASTING THROUGH THE REMAINDER
OF THE VALID PERIOD. EXPECT SOUTHWEST WINDS...BECOMING SOUTH-
SOUTHWEST WITH SUSTAINED WINDS AOB 8 KTS BY THE AFTERNOON
HOURS...BECOMING LIGHT INTO THE EVENING HOURS.
EXTENDED OUTLOOK...A SLIGHT CHANCE OF SHOWERS ON WEDNESDAY
ASSOCIATED WITH A COLD FRONT. OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 12:30 AM TUESDAY...NO CHANGES TO THE FORECAST WITH LATEST
UPDATE. SEAS CONTINUE IN THE 2 FT RANGE...WITH LIGHT AND VARIABLE
WINDS. PREVIOUS DISCUSSION FROM 630 PM FOLLOWS...
LIGHT SOUTH THROUGH WEST WINDS WILL CONTINUE THROUGH THE NIGHT AS
HIGH PRESSURE REMAINS JUST OFFSHORE. SEAS CONSIST ALMOST EXCLUSIVELY
OF A 9 SECOND SOUTHEAST SWELL...AVERAGING 2-3 FT. THE ONLY CHANGE TO
THE FORECAST IS TO RAISE AIR TEMPERATURE FORECASTS BY UP TO 5
DEGREES ACROSS THE OUTER PORTION OF THE COASTAL WATERS WITH THE MILD
SUBTROPICAL AIRMASS. PREVIOUS DISCUSSION FROM 300 PM FOLLOWS...
DESPITE WINDS BEING LESS THAN 10KT TODAY AND EVEN HAVING SOME
VARIABILITY IN DIRECTION THERE IS JUST ENOUGH SWELL ENERGY FOR A 3
FT WAVE OUT AT 41013 AND 41036. WNA AND SWAN SHOW THAT FOR THE MOST
PART THE 3 FT SEAS WILL LARGELY REMAIN OUTSIDE OF THE 20NM FORECAST
ZONES SAVE FOR ALONG FRYING PAN SHOALS..AND EVEN THAT MIGHT BE A
STRETCH. WILL ADVERTISE 2 FT FOR ALL BUT AMZ252 WHERE 2 TO 3 FT WILL
STILL BE ADVERTISED. EVE SHIFT MAY BE ABLE TO DROP 3 FT SEAS AFTER
MONITORING BUOY DATA.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY...WINDS WILL BE LIGHT AT 12 UTC ON TUESDAY AND AS
HIGH PRESSURE GIVES AWAY TO FRONTAL BOUNDARY THE WIND DIRECTION WILL
SWING TO THE SOUTHWEST AND INCREASE UP TO 10 KNOTS BY THE END OF THE
DAY. THE WINDS WILL CONTINUE TO VEER FROM THE SOUTHWEST TO NORTHEAST
AS THE FRONT MOVES ACROSS THE COASTAL WATERS. COLD AIR ADVECTION
WILL FOLLOW AND WINDS SPEED ARE EXPECTED TO INCREASE TO 20 TO 25
KNOTS FROM THE NORTHEAST LATE WEDNESDAY NIGHT. A SMALL CRAFT
ADVISORY MAY BE LIKELY IF THE MODELS CONSISTENCY CONTINUES.
LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 3 PM MONDAY...NORTHEAST WINDS INITIALLY FROM 15-20 KNOTS AS
HIGH PRESSURE BUILDS DOWN THE EAST COAST. SPEEDS WILL QUICKLY
DIMINISH TO LESS THAN TEN KNOTS BY FRIDAY MORNING. WILL PROBABLY
HAVE A MARGINAL SMALL CRAFT ADVISORY FOR SEAS AS WELL THURSDAY.
WIND SHIFT OCCURS LATE FRIDAY TO SOUTHEAST AS THE AFOREMENTIONED
HIGH QUICKLY MOVES OFFSHORE. SPEEDS WILL REMAIN LIGHT AND CONTINUE
THROUGH SATURDAY. SIGNIFICANT SEAS WILL DROP TO AROUND TWO FEET.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...REK/MBB
SHORT TERM...DRH
LONG TERM...SHK
AVIATION...SGL
MARINE...REK/MBB/SHK/DRH
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
929 AM EST TUE DEC 4 2012
.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL PREVAIL THROUGH WEDNESDAY. A COLD FRONT
WILL MOVE ACROSS THE AREA WEDNESDAY NIGHT...FOLLOWED BY A WEDGE OF
HIGH PRESSURE FROM THE NORTH THROUGH LATE WEEK. A COASTAL TROUGH
WILL FORM OFFSHORE ON FRIDAY...THEN SHIFT INLAND OR DISSIPATE EARLY
IN THE WEEKEND. ATLANTIC HIGH PRESSURE WILL THEN PREVAIL THROUGH
EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AN EXTENSIVE MID-LEVEL CLOUD DECK REMAINS ANCHORED OVER THE AREA
THIS MORNING. RAP SOUNDINGS WOULD SUGGEST A GOOD PORTION OF THIS
CLOUD DECK WILL THIN AND MIX OUT OVER THE NEXT FEW HOURS AS
SURFACE TEMPERATURES SLOWLY WARM. IT LOOKS LIKE SIGNIFICANT
CLEARING WILL LIKELY NOT OCCUR UNTIL TEMPERATURES REACH THE UPPER
60S TO LOWER 70S PER THE 04/12Z CHS RAOB. STILL EXPECT A DECENT
AMOUNT OF SUN THIS AFTERNOON WITH PARTLY CLOUDY SKIES. HOWEVER...
AS TEMPERATURES WARM...EXPECT ANOTHER RATHER ROBUST CUMULUS FIELD
TO DEVELOP WITH THE BULK OF THE CLOUD COVER SHIFTING INLAND WITH
THE SEA BREEZE. HAVE ADJUSTED THE SKY COVER FORECAST TO MATCH THIS
THINKING. TEMPERATURES ARE POISED TO RISE RAPIDLY WHERE INSOLATION
INCREASES. HIGHS IN THE MID 70S AWAY FROM THE COAST LOOK
REASONABLE...BUT COULD EASILY SEE A FEW UPPER 70S IF CLOUDS BREAK
SOONER THAN EXPECTED.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
TONIGHT...ANOTHER ROUND OF FOG EXPECTED BUT COVERAGE AND INTENSITY
SHOULD BE LESS THAN PREVIOUS NIGHTS GIVEN THE INCREASE IN HIGH
LEVEL MOISTURE AND LOW-LEVEL WINDS AS A COLD FRONT BEGINS TO
APPROACH FROM THE WEST. LOWS SHOULD RANGE FROM THE LOWER 50S
INLAND TO MID/UPPER 50S AROUND THE COAST.
WEDNESDAY AND WEDNESDAY NIGHT...THERE WILL BE TWO DISTINCT TROUGHS
IN THE MID AND UPPER LEVELS OF THE ATMOSPHERE THAT WILL INFLUENCE
THE WEATHER ACROSS THE REGION. THE FIRST WILL BE A TROUGH WHICH
SLOWLY MOVES ACROSS THE NORTHERN GULF OF MEXICO...HELD BACK SOME BY
WEAK RIDGING ACROSS THE SOUTHEAST ATLANTIC. THE OTHER TROUGH WILL
MOVE ACROSS NEW ENGLAND AND IS DEEPER YET MORE PROGRESSIVE DUE TO
THE INFLUENCE OF THE POLAR JET. AT THE SURFACE...THIS TRANSLATES TO
MORE OF A BACKDOOR COLD FRONT WHICH DROPS SLOWLY THROUGH THE AREA
WEDNESDAY NIGHT.
SOMEWHAT ORGANIZED SHOWERS WILL APPROACH FROM THE NORTHWEST ON
WEDNESDAY...BUT BECOME CONSIDERABLY MORE DISORGANIZED AS THE FRONT
NEARS LATE WEDNESDAY AFTERNOON INTO WEDNESDAY NIGHT DUE A WESTERLY
FLOW IN PLACE AHEAD OF THE BOUNDARY WHICH SHOULD LIMIT DEEP
MOISTURE. THE FORECAST WILL INDICATE A 20-30 PERCENT CHANCE OF
SHOWERS ACROSS THE NORTH/NORTHWEST PORTION OF THE FORECAST AREA
WEDNESDAY AFTERNOON WITH RAIN-FREE CONDITIONS ELSEWHERE. ON
WEDNESDAY NIGHT...THE FORECAST WILL INDICATE A 20-30 PERCENT CHANCE
OF SHOWERS AS WELL...WITH THE HIGHEST PROBABILITIES ACROSS SOUTHEAST
SOUTH CAROLINA.
DESPITE INCREASING CLOUD COVER...THE DOWNSLOPE FLOW AND
COMPRESSIONAL HEATING ALONG AND AHEAD OF THE COLD FRONT SHOULD ALLOW
TEMPERATURES TO REACH HIGHS IN THE MID 70S AWAY FROM THE COAST ON
WEDNESDAY. LOWS WEDNESDAY NIGHT SHOULD BE IN THE LOWER TO MID 50S
DUE TO THE EXTENSIVE CLOUD COVER.
THURSDAY AND THURSDAY NIGHT...MODELS ARE IN PRETTY GOOD AGREEMENT
SHOWING A WEDGE OF HIGH PRESSURE BUILDING SOUTHWARD INTO THE AREA.
THERE APPEARS TO BE CONSIDERABLE LOW AND MID LEVEL MOISTURE TRAPPED
BENEATH THE INVERSION...WHICH SHOULD TRANSLATE TO MOSTLY CLOUDY
SKIES...ESPECIALLY ACROSS SOUTHEAST SOUTH CAROLINA. WEAK ISENTROPIC
ASCENT COULD SUPPORT A SLIGHT CHANCE OR LOW CHANCE OF LIGHT SHOWERS
JUST ABOUT ANYWHERE. THERE SHOULD BE A LARGE GRADIENT IN HIGH
TEMPERATURES...WHICH SHOULD RANGE FROM THE MID TO UPPER 50S IN THE
FAR NORTHWEST PORTION OF THE FORECAST AREA TO THE UPPER 60S NEAR THE
ALTAMAHA RIVER AND OTHER PORTIONS OF NORTH COASTAL GEORGIA. LOWS
THURSDAY NIGHT ARE TRICKY TO FORECAST AS WELL...WITH MID TO UPPER
40S EXPECTED IN MOST AREAS.
FRIDAY...AS HIGH PRESSURE CONTINUES TO SHIFT OFFSHORE AWAY FROM THE
NEW ENGLAND COAST...A COASTAL TROUGH IS EXPECTED TO DEVELOP JUST OFF
THE SOUTHEAST U.S. COAST. THERE COULD BE SOME ISOLATED SHOWERS ALONG
THE COAST IN ASSOCIATION WITH THE TROUGH...BUT THE BULK OF THE
PRECIPITATION IS EXPECTED TO REMAIN OFFSHORE. AS THE WEDGE SLOWLY
ERODES...HIGHS SHOULD REACH THE MID 60S ACROSS MUCH OF SOUTHEAST
SOUTH CAROLINA AND THE UPPER 60S TO NEAR 70 IN SOUTHEAST GEORGIA.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
MEDIUM RANGE GUIDANCE IS IN FAIRLY GOOD AGREEMENT THROUGH THE LONG
TERM PERIOD...WHICH WILL FEATURE A BUILDING UPPER LEVEL RIDGE OVER
THE SOUTHEAST STATES. AT THE SURFACE...A COASTAL TROUGH IS EXPECTED
TO DAMPEN OUT AND/OR SHIFT INLAND FRIDAY NIGHT INTO SATURDAY...WITH
ATLANTIC HIGH PRESSURE THEN PREVAILING INTO EARLY NEXT WEEK. A COLD
FRONT IS THEN EXPECTED TO ADVANCE TOWARD THE AREA FROM THE NORTHWEST
ON TUESDAY.
THERE IS A SLIGHT CHANCE FOR SHOWERS AT JUST ABOUT ANY TIME THROUGH
MONDAY NIGHT AS A MOIST SOUTHERLY FLOW DEVELOPS OVER THE AREA. THE
PROBABILITY FOR SHOWERS WILL INCREASE INTO THE CHANCE CATEGORY ON
TUESDAY AHEAD OF THE APPROACHING FRONT. TEMPERATURES WILL BE WELL
ABOVE NORMAL UNDER THE INFLUENCE OF THE BUILDING RIDGE.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
EXTENSIVE MID LEVEL CLOUD COVER HAS KEPT FOG FROM FORMING AT THE
TERMINALS EARLY THIS MORNING...ALTHOUGH SOME BREAKS IN THE CLOUD
COVER NOTED JUST UPSTREAM OF KCHS COULD CAUSE A TEMPORARY/BRIEF
DROP IN VISIBILITIES TO MVFR OR LOWER LEVELS FROM ABOUT 13-14Z.
FOG IS POSSIBLE ONCE AGAIN TONIGHT...BUT WITH UNCERTAINTY IN
EXTENT OF POSSIBLE CLOUD COVER JUST HAVE PREVAILING 6SM IN THE TAF/S
AFTER 06Z. IF SKIES ARE RELATIVELY CLEAR...THEN MVFR OR LOWER
CONDITIONS ARE POSSIBLE LATE TONIGHT.
EXTENDED AVIATION OUTLOOK...LOW CEILINGS POSSIBLE WEDNESDAY NIGHT
AS A COLD FRONT MOVES THROUGH...THEN CONTINUING THROUGH THURSDAY
NIGHT AS A WEDGE OF HIGH PRESSURE BUILDS FROM THE NORTH. OUTSIDE
OF THESE PERIODS...MAINLY VFR.
&&
.MARINE...
TODAY AND TONIGHT...ATLANTIC HIGH PRESSURE WILL REMAIN IN CONTROL
THROUGH TONIGHT WITH A WEAK PRESSURE PATTERN SUPPORTING WINDS
MAINLY 10 KT OR LESS. SEAS DOMINATED BY ABOUT A 9 SECOND EAST
SWELL...RANGING FROM 2-3 FT NEARSHORE TO 3-4 FT BEYOND 20 NM.
POSSIBLY A BIGGER CONCERN THIS PERIOD WILL BE FOG ACROSS THE COOL
NEARSHORE WATERS AS A HUMID AIRMASS REMAINS IN PLACE.
WEDNESDAY THROUGH SUNDAY...ATLANTIC HIGH PRESSURE WILL GRADUALLY
WEAKEN AND DRIFT FARTHER OUT TO SEA WEDNESDAY AS A COLD FRONT
APPROACHES FROM THE NORTHWEST AND MOVES THROUGH THE MARINE ZONES
WEDNESDAY NIGHT. SURFACE HIGH PRESSURE WILL RAPIDLY BUILD A WEDGE
FROM THE NORTH THROUGH THURSDAY NIGHT. SMALL CRAFT ADVISORY
CONDITIONS ARE POSSIBLE ACROSS MOST OF THE COASTAL WATERS WEDNESDAY
NIGHT INTO THURSDAY NIGHT...AS THE PRESSURE GRADIENT TIGHTENS AND A
NORTHEAST SURGE DEVELOPS BEHIND THE COLD FRONT. THE CENTER OF HIGH
PRESSURE WILL THEN MOVE INTO THE ATLANTIC WATERS AND LINGER THROUGH
SUNDAY.
SEA FOG WILL BE A POSSIBILITY THROUGH WEDNESDAY...AS A MOIST AIR
MASS ADVECTS OVER THE COASTAL WATERS. WILL CONTINUE TO MENTION
PATCHY FOG ACROSS THE NEAR SHORE COASTAL WATERS AND CHARLESTON
HARBOR. IF FOG DOES INDEED FORM...IT COULD BE DENSE AT TIMES.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
ST
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
619 AM EST TUE DEC 4 2012
.SYNOPSIS...
ISSUED AT 306 AM EST TUE DEC 4 2012
A BROKEN LINE OF SHOWERS AHEAD OF A COLD FRONT IS MOVING ACROSS
LOWER MICHIGAN EARLY THIS MORNING. THE RAIN WILL MOVE OUT OF THE
AREA BY LATE MORNING. WE/LL SEE SOME SUNSHINE THIS AFTERNOON BUT
TEMPERATURES WILL BE MUCH COOLER THAN YESTERDAY. THERE IS A CHANCE
OF MIXED RAIN AND SNOW FROM THURSDAY THROUGH THE WEEKEND.
TEMPERATURES WILL BE NEAR NORMAL.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 306 AM EST TUE DEC 4 2012
FORECAST CONCERNS DEAL PCPN TRENDS THIS MORNING. OVERALL...THE
FORECAST HASN/T CHANGED MUCH.
REGIONAL RADAR SHOWS A BROKEN BAND OF SHOWERS STRETCHING FROM NRN
LAKE HURON SWWD TO NEAR ST LOUIS. THIS PCPN IS ALIGNED ALONG THE
COLD FRONT WHICH IS PUSHING THROUGH THE CWA ATTM. LATEST IR LOOP
SHOWS COOLING CLOUD TOPS OVER ILLINOIS. THIS IS LIKELY IN RESPONSE
TO A WAVE ON THE SRN PORTION OF THE FRONT. HRRR SUGGESTS WE/LL SEE A
LARGER AREA OF PCPN MOVE INTO THE SRN/SE CWA PRIOR TO SUNRISE AS THE
WAVE MOVES NEWD. THIS JUST APPEARS TO BE RAIN...LIGHTNING REMAINS
WELL SW OF THE GREAT LAKES. PCPN WILL END FROM NW TO SE THIS
AFTERNOON AS THE WAVE MOVES MOVES THROUGH.
A SECONDARY COLD FRONT WILL MOVE SEWD THROUGH LOWER MICHIGAN
TONIGHT. WE MAY BRIEFLY SEE A FEW SHSN DEVELOP ALONG THE LAKE SHORE
NORTH OF HOLLAND BUT THEY WON/T AMOUNT TO MUCH AND WILL QUICKLY FADE
BY WEDNESDAY MORNING AS CORE OF THE COLD AIR MOVES EAST. HIGH
PRESSURE WILL SETTLE OVER THE CWA WEDNESDAY.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 306 AM EST TUE DEC 4 2012
CHALLENGING FORECAST IN THE EXTENDED AS MODEL CONSISTENCY HAS
BEEN POOR THE LAST COUPLE DAYS HANDLING THE DETAILS OF AN INVERTED
TROUGH/SFC WAVE MOVING ALONG THE FRONT STALLED ACROSS THE OHIO
VALLEY...AND A MORE SIGNIFICANT STORM EARLY NEXT WEEK.
WENT WITH LOW CHANCE OR SLIGHT CHANCE POPS EARLY IN THE PERIOD WITH
LOW CONFIDENCE ON DETAILS OF WHEN AND WHERE BEST CHANCES FOR PRECIP
WITH BE. P-TYPE IS ALSO A TOUGH CALL AS THERMAL PROFILES SUGGEST MIX
NORTH AND RAIN SOUTH.
A HIGHER IMPACT EVENT IS EXPECTED NEXT WEEK AS STRONG UPPER TROUGH
MOVES INTO THE ROCKIES WITH SFC LOW FORMING OVER THE PLAINS AND
HEADING FOR LOWER MICHIGAN. AGAIN CONFIDENCE IS LOW ON TIMING DUE TO
MODEL DIFFERENCES AND INCONSISTENCY...BUT A MIXED PRECIP TO RAIN
THEN OVER TO SNOW SCENARIO IS POSSIBLE EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 618 AM EST TUE DEC 4 2012
RAIN WILL CONTINUE FROM AZO TO LAN THIS MORNING WITH SOME MVFR
CONDITIONS PERSISTING THERE UNTIL AROUND 16Z. JXN WILL SEE SOME
MVFR AND EVEN IFR CONDITIONS AS THE RAIN WILL BE SLOW TO MOVE
EAST. ALL LOCATIONS SHOULD BE VFR BY THIS AFTERNOON AND EVENING.
&&
.MARINE...
ISSUED AT 306 AM EST TUE DEC 4 2012
COLD ADVECTION WILL INCREASE WAVE HEIGHTS TODAY INTO WEDNESDAY. WE
EXTENDED THE SCA THROUGH THE AFTERNOON WEDNESDAY.
&&
.HYDROLOGY...
ISSUED AT 306 AM EST TUE DEC 4 2012
NO HYDRO ISSUES THIS MORNING QPF LESS THAN A QUARTER INCH IS
EXPECTED FROM SHOWERS ALONG THE COLD FRONT THIS MORNING.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 5 PM EST WEDNESDAY FOR LMZ844>849.
&&
$$
SYNOPSIS...93
SHORT TERM...93
LONG TERM...OSTUNO
AVIATION...OSTUNO
HYDROLOGY...93
MARINE...93
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
350 PM MST TUE DEC 4 2012
.SHORT TERM...MODERATE WEST TO NORTHWEST FLOW ALOFT ACROSS REGION
WITH SHORT WAVE RIDGE OVER GREAT BASIN. WEAK STABLE LAYER
CURRENTLY AT MOUNTAIN TOP WITH RADAR SHOWING SOME SIGNS OF A
MOUNTAIN WAVE. WINDS ALOFT NOT VERY STRONG WITH CROSS MOUNTAIN
FLOW 30-35 KTS AT MOUNTAIN TOP. SOME RECENT GUSTS TO 40 MPH BEING
REPORTED IN THE ESTES PARK AREA...BUT APPEAR LOCALIZED AND PERHAPS
TERRAIN DRIVEN. LATEST RUC CROSS SECTIONS INDICATE WINDS ALOFT
GRADUALLY DECREASING AFTER 02Z WITH CROSS MOUNTAIN WINDS AROUND 25
KTS NEAR RIDGE TOP AND ALONG HIGHER FOOTHILLS BY 06Z. THUS SHOULD
SEE WIND GUSTS GRADUALLY DECREASE DURING THE EVENING THOUGH THE
TERRAIN MAY KEEP THINGS A BIT GUSTY. SHOULD ALSO SEE A GRADUAL
INCREASE IN HUMIDITY AS TEMPERATURES COOL. LATEST SATELLITE LOOPS
SHOW CLOUDS HAVE THINNED ACROSS THE AREA WITH REMNANTS OF WAVE
CLOUD EAST OF URBAN CORRIDOR. MORE MOISTURE UPSTREAM...WITH
INCREASING HIGH LEVEL MOISTURE OVERNIGHT. WRF SYNTHETIC SATELLITE
IMAGERY SUGGESTING THE WAVE CLOUD REDEVELOPS ALONG FOOTHILLS AFTER
08Z. ON WEDNESDAY...FLOW ALOFT BECOMES WESTERLY AS RIDGE MOVES
SOUTH AND EAST OF COLORADO. CROSS SECTIONS SHOW MOISTURE
INCREASING ACROSS THE AREA WITH SOME LOWERING OF THE MOISTURE
ACROSS MOUNTAINS DURING THE MORNING...MAINLY NORTH OF INTERSTATE
70. MAY BE ENOUGH OROGRAPHICS TO GENERATE SOME SHOWERS ACROSS ZONE
31. OTHERWISE WINDS ALOFT TO INCREASE WITH CROSS MOUNTAIN FLOW AROUND
40 KTS AT MOUNTAIN TOP BY 18Z. THUS WINDS TO BE GUSTY ACROSS THE
MOUNTAINS AND HIGHER FOOTHILLS WITH LOCAL GUSTS AROUND 45 MPH
POSSIBLE DURING THE AFTERNOON. THE GUSTY WINDS WILL KEEP THE FIRE
DANGER ELEVATED ALONG THE FOOTHILLS...BUT HUMIDITY SHOULD REMAIN
ABOVE CRITICAL FIRE WEATHER THRESHOLDS. TEMPERATURE AND THICKNESS
PROGS AS WELL AS GUIDANCE SHOWING HIGHS IN THE 60S ACROSS THE
PLAINS. THIS LOOKING REASONABLE. CURRENT TEMPERATURE GRIDS IN LINE
WITH GUIDANCE...ONLY MINOR CHANGES NEEDED.
.LONG TERM...WESTERLY FLOW ALOFT WILL PREVAIL WEDNESDAY NIGHT AND
THURSDAY. WINDS WILL INCREASE WEDNESDAY NIGHT OVER THE MOUNTAINS AND
FOOTHILLS AS A COLD FRONT MOVES THROUGH THE STATE. A WEAK SHORT
WAVE TROUGH MAY BRING LIGHT SNOW TO THE MOUNTAINS AND PERHAPS SOME
LIGHT RAIN OVER EASTERN COLORADO THURSDAY.
THE WESTERLY JET WILL SINK SOUTH AS AN UPPER LEVEL TROUGH MOVES ONTO
THE PACIFIC NORTHWEST COAST. THIS WILL BRING COOLER CONDITIONS ON
FRIDAY WITH HIGHS IN THE 40S. ANOTHER WEAK DISTURBANCE EMBEDDED IN
THE FLOW ALOFT WILL BRING ANOTHER CHANCE FOR LIGHT PRECIPITATION.
THE UPPER LEVEL TROUGH OVER THE PACIFIC NORTHWEST WILL DIVE SOUTH
ACROSS THE GREAT BASIN SATURDAY AND END UP OVER THE SOUTHERN ROCKIES
SUNDAY. THIS WILL PUSH A STRONG COLD FRONT ACROSS COLORADO. STILL
SOME DIFFERENCE ON TRACK AND TIMING...BUT WILL BE ENOUGH ENERGY TO
BRING A PERIOD OF SNOW TO THE AREA. BIGGEST QUESTIONS ARE WHEN AND
HOW MUCH. APPEARS THE SNOW WILL BEGIN SOMETIME SATURDAY AND COME TO
AN END EARLY SUNDAY. MAY SEE SOME HEAVIER SNOW BANDS SATURDAY AS THE
JEST SINKS SOUTH ACROSS COLORADO. WILL CENTER THE HIGHEST POPS
AROUND SATURDAY NIGHT WHEN THE BEST CHANCE WILL BE ACCORDING TO THE
MODELS. COLD AIR WILL MOVE IN WITH THIS SYSTEM AND HIGHS WILL LIKELY
REMAIN BELOW FREEZING SUNDAY AND EARLY NEXT WEEK. NORTHWEST FLOW MAY
BRING LIGHT OROGRAPHIC SNOW EARLY NEXT WEEK...OTHERWISE JUST DRY AND
COOL CONDITIONS ARE EXPECTED FOR MONDAY AND TUESDAY.
&&
.AVIATION...LIGHT EASTERLY WINDS AT APA AND DEN TO WEAK AND BECOME
SOUTHERLY AS DRAINAGE PATTERN DEVELOPS. WINDS TO REMAIN WESTERLY
AT BJC. ON WEDNESDAY...WINDS TO BECOME NORTHWEST AFTER 18Z WITH
SPEEDS AROUND 8 KTS. HIGH LEVEL MOISTURE TO INCREASE AFTER 06Z
WITH THE POTENTIAL FOR A WAVE CLOUD ALONG FOOTHILLS BY 10Z. VFR TO
CONTINUE WITH CEILINGS UNLIMITED.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...D-L
LONG TERM....MEIER
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
936 AM MST TUE DEC 4 2012
.UPDATE...
&&
.SHORT TERM...CURRENT FORECASTS STILL ON TRACK. WINDS TO BE ON THE
INCREASE DURING THE AFTERNOON...WITH BOTH NAM AND RUC CROSS
SECTIONS INDICATING CROSS MOUNTAIN FLOW AROUND 35 KTS AT MOUNTAIN
TOP BY 00Z. WINDS LOOKING MARGINAL FOR RED FLAG CONDITIONS DESPITE
THE LOW HUMIDITY. A FEW AREAS ALONG FOOTHILLS MAY REACH CRITERIA
FOR A SHORT TIME...MAINLY LOCATIONS WHERE TERRAIN WILL AID IN
FUNNELLING THE WINDS. STILL SOME THINNING OF WAVE CLOUD THROUGH
THE AFTERNOON...THEN REDEVELOPING OVERNIGHT WITH ARRIVAL OF DEEPER
MOISTURE.
.AVIATION...CURRENT TAF TRENDS LOOK REASONABLE...WILL CONTINUE FOR
THE UPCOMING ISSUANCE.
&&
.PREV DISCUSSION... /ISSUED 352 AM MST TUE DEC 4 2012/
SHORT TERM...CLOUDS WILL INCREASE FROM WEST TO EAST DURING THE
DAY AS WARMER AIR SPREADS OVER THE AREA. DESPITE THE HIGH
CLOUDINESS...THERE IS STILL SOME PRETTY DRY AIR AT LOW LEVELS. DEW
POINTS HAVE COME UP IN THE MOUNTAINS OVERNIGHT...MODEL GUIDANCE
SHOWS SURFACE DEW POINTS DROPPING AGAIN WITH MIXING DURING THE
DAY...BUT THEN RISING LATER IN THE DAY AS LOW LEVEL MOISTURE
FINALLY ARRIVES. I AM RATHER PESSIMISTIC ABOUT THE TIMING OF THIS
AND WILL HEDGE TOWARD LOWER VALUES THIS AFTERNOON. WINDS ALSO WILL
BE COMING UP LATE IN THE DAY...BUT FLOW ALOFT IS NOT THAT STRONG
WITH 20 KNOTS INCREASING TO 35 KNOTS AT 600 MB. ALSO A WEAK STABLE
LAYER...SO NOT EXPECTING WAVE AMPLIFICATION BUT THERE WILL BE SOME
STRONGER FLOW SPILLING DOWN THE HIGHER EAST SLOPES OF THE FRONT
RANGE. ALL IN ALL NOT MUCH OF A HIGH WIND THREAT AND MARGINAL ON
WIND AND ESPECIALLY HUMIDITY FOR A RED FLAG WARNING IN ZONE 35
ONLY...SO NO HIGHLIGHTS. MODELS SHOW SOME THINNING OF THE CLOUDS
THIS EVENING THEN DEEPER MOISTURE ARRIVING INTO THE MOUNTAINS LATE
TONIGHT...THOUGH THE GFS HOLDS THE BEST MOISTURE UP IN WYOMING.
THIS LOOKS REASONABLE AS THE SATELLITE PICTURES SEEM TO SHOW THESE
FEATURES...SOME LOWER CLOUDS IN NORTHERN NEVADA SO THIS MAY CLIP
THE PARK RANGE BUT WILL LEAVE THE CHANCE OF SNOW FOR DAYTIME ON
WEDNESDAY. FORECAST TEMPS ARE NEAR GUIDANCE AND LOOK PRETTY GOOD.
LONG TERM...ZONAL FLOW WILL BE OVER THE AREA ON WED WITH QUITE A
BIT OF MID AND HIGH LEVEL MOISTURE STREAMING ACROSS. COULD SEE A
SLIGHT CHC OF SHOWERS IN ZN 31 OTHERWISE WILL KEEP FCST DRY. HIGHS
ON WED WILL BE MILD WITH READINGS MAINLY IN THE 65 TO 70 DEGREE
RANGE ACROSS NERN CO. WINDS WILL BE GUSTY AT TIMES IN THE MTNS AND
NRN FOOTHILLS BUT SPEEDS SHOULD REMAIN BLO WARNING CRITERIA. FOR
WED NIGHT INTO THU MOISTURE WILL DEEPEN IN THE MTNS WITH SLIGHTLY
BETTER LAPSE RATES AS A WEAK UPPER LEVEL TROUGH MOVES ACROSS. THUS
SHOULD SEE A BETTER CHC OF SNOW IN THE MTNS ALTHOUGH ACCUMULATIONS
WILL STILL BE ON THE LIGHT SIDE. OVER NERN CO A WK CDFNT WILL
AFFECT THE AREA HOWEVER CROSS-SECTIONS SHOW ONLY WEAK UPSLOPE
FLOW. WILL LEAVE IN A SLIGHT CHANCE OF PCPN DUE TO PASSAGE OF WK
UPPER LEVEL TROUGH. SOUNDING DATA SHOWS SNOW LEVEL MAINLY ABOVE
7000 FEET SO WILL KEEP PCPN IN THE FORM OF RAIN WITH A MIXTURE IN
THE FOOTHILLS. HIGHS ON THU WILL BE COOLER WITH READINGS IN THE
50S ACROSS NERN CO. WINDS WILL REMAIN GUSTY IN THE MTNS AND
FOOTHILLS WED NIGHT INTO THU MORNING HOWEVER ONCE AGAIN SPEEDS
SHOULD STAY BLO HIGHLIGHT CRITERIA.
ON FRI LATEST DATA SHOWS A STRONGER JET MOVING INTO NRN IN WNW
FLOW ALOFT WITH ANOTHER WK UPPER LVL TROUGH. THUS COULD SEE
ANOTHER CHC OF SNOW IN THE MTNS WITH GUSTY WINDS. LAPSE RATES WILL
IMPROVE WITH THIS SECOND FEATURE SO ACCUMULATIONS MAY END UP BEING
BETTER WITH SOME ENHANCEMENT DUE TO POSITION OF UPPER LEVEL JET.
OVER NERN CO LATEST GFS SHOWS ANOTHER FNT MOVING INTO NERN CO BY
MIDDAY WITH SOME WK UPSLOPE FLOW WHILE THE ECMWF DOES NOT SHOW A
THIS FNT COMING IN UNTIL FRI EVENING. AM A LITTLE CONCERNED WITH
POSITION OF UPPER LVL JET AND DECENT LAPSE RATES ACROSS NERN CO
FRI AFTN INTO FRI EVENING. IF ENOUGH MOISTURE IS PRESENT COULD SEE
AT LEAST A SLIGHT CHC OF SHOWERS EITHER FRI AFTN OR FRI NIGHT
DEPENDING ON TIMING OF FNT. AS FOR HIGHS 850-700 MB TEMPS ARE
COOLER ON FRI SO WILL KEEP READINGS IN THE 40S ACROSS NERN CO.
FOR THE WEEKEND THE ECMWF AND GFS SHOW A STRONG UPPER LEVEL TROUGH
MOVING SE ACROSS THE AREA SAT NIGHT THROUGH SUN NIGHT WITH AN
ASSOCIATED STG CDFNT. AT THIS TIME IT APPEARS THE BEST CHC OF PCPN
WILL BE FROM SAT NIGHT THRU SUN. SOME HEAVIER SNOWFALL MAY OCCUR
SAT NIGHT INTO SUN MORNING IN THE FOOTHILLS AND ALONG THE FRONT
RANGE DUE TO INCREASING UPSLOPE FLOW AND POSITION OF UPPER LEVEL
JET WHICH MAY LEAD TO BANDED PCPN. MTNS SHOULD SEE SOME SNOW AS
WELL WITH EAST FACING SLOPES HAVING THE HIGHEST ACCUMULATIONS. AS
FOR HIGHS AHEAD OF THE STG CDFNT READINGS WILL BE IN THE 40S ON
SAT OVER NERN CO WHILE ON SUN READINGS MAY STAY IN THE 20S.
BY SUN NIGHT AND MON THE UPPER LEVEL TROUGH WILL MOVE SE OF THE
AREA WITH SNOW LIKELY ENDING SUN EVENING FOLLOWED BY DRY
CONDITIONS ON MON. TEMPS ON MON WILL REMAIN COLD WITH READINGS
STAYING IN THE 20S OVER NERN CO.
AVIATION...VFR CONDITIONS AND LIGHT WINDS TODAY...SHOULD KEEP A
SOUTHERLY COMPONENT AT KDEN/KAPA WITH EASTERLIES DEVELOPING DURING
THE DAY AT KBJC. BACK TO S/W DRAINAGE WINDS THIS EVENING.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...D-L
LONG TERM....RPK
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
252 PM EST TUE DEC 4 2012
.SHORT TERM /TONIGHT THROUGH THURSDAY/...
MAIN FORECAST PROBLEM THROUGH WEDNESDAY IS LIKELIHOOD FOR MEASURABLE
PRECIP. SHORT WAVE CURRENTLY LOCATED OVER SE OK/NRN TX ON WV IMAGERY
TRACKING EAST WITH CONSIDERABLE AMOUNT OF DEEP CONVECTION OCCURRING
AHEAD OF THE WAVE OVER THE LOWER MS VALLEY. MODELS HAVE VERY GOOD
AGREEMENT ON TIMING OF WAVE AND ASSOCIATED FRONT MOVING INTO THE FAR
NORTH LATE TONIGHT. MODELS ALSO IN STRONG AGREEMENT THAT VERTICAL
LIFT WILL WEAKEN TONIGHT AND WEDNESDAY WITH MUCH LOWER PRECIP
AMOUNTS AS THE SYSTEM MOVES INTO THE STATE. ALWAYS A CHALLENGE TO
FORECAST POPS IN THIS SITUATION AS WILL LIKELY SEE SCT LIGHT SHOWERS
ACROSS NORTHERN 3/4THS OF CWA BUT NOT CONFIDENT THAT ALL THESE
SHOWERS WILL PRODUCE MEASURABLE RAINFALL. HAVE KEPT POPS LATE
TONIGHT AND WED CONFINED TO LKLY CATEGORY OVER AREAS NORTH OF ATL
METRO AND 40-60 OVER METRO AND MUCH OF MIDDLE GA. NEAR-TERM MODELS
INCLUDING RADAR ASSIMILATING MODELS SUCH AS THE HRRR ARE INDICATING
BEST CHC FOR RAIN IN THE ATL METRO AROUND 6-8AM WITH LINGERING CHC
OF SCT LIGHT SHOWERS DURING THE DAY. USED MAV/MET BLEND FOR TEMPS
WITH A SLIGHT UPWARD ADJUSTMENT FOR MIN TEMPS TONIGHT.
BY WED...SUBSIDENCE BEHIND STRONG WAVE OVER THE NORTHEAST CONUS
YIELDS A EXPANSIVE 1035MB SFC HIGH OVER THE MIDWEST WHICH IS PROGGED
TO SPILL OVER AND DAM UP ALONG THE APPALACHIANS. SIGNIFICANT WEDGE
EVENT SHOULD RESULT BUT AS MENTIONED EARLIER...WE ARE FORTUNATE THAT
THE SOURCE AIRMASS FOR THIS HIGH IS NOT ARCTIC OR THAT COLD.
OTHERWISE WE MIGHT BE IN A WORLD OF HURT. OTHER THAN SOME COOL EAST
WINDS AND SOME PATCHY LIGHT RAIN AND FAIRLY WIDESPREAD CLOUDS...
SHOULD NOT BE TOO BAD FOR DECEMBER.
SNELSON
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
OVERALL...PREVIOUS FORECAST LOOKS TO BE ON TRACK. HAVE CONTINUED
WITH SLIGHT CHANCE POPS AS THE WEDGE REMAINS IN PLACE THROUGH LATE
WEEK WITH MODELS STILL INDICATING ISENTROPIC LIFT AND UPSLOPE FLOW
WILL SUPPORT LIGHT RAIN. MODEL GUIDANCE HAVE WARMED SLIGHTLY
DURING THE CAD EVENT...AND HAVE INCREASED MORNING LOW TEMPERATURES
SLIGHTLY FOR BETTER CONSISTENCY WITH THE SURROUNDING OFFICES. FOR
NOW...HAVE MADE A FEW VERY MINOR TWEAKS TO HIGH TEMPERATURE...BUT
OVERALL THINK THE MODELS ARE TOO WARM. THERE IS STILL ENOUGH
UNCERTAINTY WITH LATE WEEKEND AND EARLY WEEK MODEL SOLUTIONS THAT
HAVE OPTED NOT TO MAKE ANY SIGNIFICANT CHANGES AT THIS TIME.
HAVE INCLUDED THE PREVIOUS DISCUSSION BELOW.
31
ISSUED 356 AM EST TUE DEC 4 2012/
FRONT IMPACTING NORTH GEORGIA DURING THE SHORT TERM WILL BRIEFLY
STALL OUT ACROSS CENTRAL GEORGIA WEDNESDAY NIGHT INTO THURSDAY
MORNING. THIS BOUNDARY WILL PUSH FARTHER SOUTH AND WEST AS A WEDGE
FRONT ON THURSDAY DUE TO HYBRID CAD FROM A 1027 MB PARENT HIGH OFF
THE MID- ATLANTIC COAST. HAVE INCLUDED SLIGHT POPS FOR SHOWERS AS
THIS BOUNDARY INTERACTS WITH OVERRUNNING MOISTURE FROM THE SOUTH.
GUIDANCE SUGGESTS CONTINUED ISENTROPIC UPGLIDE ACROSS MUCH OF THE
AREA THROUGH FRIDAY SO HAVE KEPT SLIGHT CHANCE POPS FOR SHOWERS
FOR THE MAJORITY OF THE CWA AND MOSTLY CLOUDY SKIES DURING THIS
PERIOD. ANY ENHANCED SOLAR SHELTERING ACROSS THE CAD DOME MAY
REINFORCE THE WEDGE AND LEAD TO LATER EROSION THAN WHAT GUIDANCE
SUGGESTS... POSSIBLY LINGERING INTO THE WEEKEND. THIS WILL NEED TO
BE MONITORED CLOSER AS THIS FEATURE GETS INCLUDED IN THE SHORT
TERM MODELS.
BROAD SW FLOW ALOFT SETS UP FOR THE WEEKEND AND A STATIONARY FRONT
LOOKS TO BECOME SITUATED NW OF THE AREA ACROSS THE TN AND OHIO RIVER
VALLEYS. THE GFS AND ECMWF DIFFER GREATLY IN THE STRENGTH OF THE
BAROCLINITY AND EXPANSE OF THE MOISTURE FIELD WITH THIS
FEATURE...THOUGH SOME SHOWER DEVELOPMENT IS POSSIBLE ACROSS NORTH
GEORGIA IF ENOUGH MOISTURE EXISTS WITH SOME OROGRAPHIC ENHANCEMENT
DUE TO SOUTHERLY/SOUTHWESTERLY LOW LEVEL FLOW. HAVE THEREFORE KEPT
SLIGHT TO LOW END CHANCE POPS FOR SHOWERS ACROSS THE NORTHERN
PORTION THROUGH THE WEEKEND.
THE LATEST RUNS OF THE GFS AND ECMWF ARE IN DECENT AGREEMENT WITH
THE NEXT SIGNIFICANT PIECE OF ENERGY SWINGING ACROSS THE SOUTHWEST
CONUS AS AN UPPER CUTOFF LOW BY SUNDAY INTO MONDAY...THEN LIFTING
NORTHEASTWARD ACROSS THE CENTRAL PLAINS BY MONDAY NIGHT INTO
TUESDAY. A STRONG COLD FRONT ASSOCIATED WITH THE PHASED SFC LOW
PRESSURE SYSTEM MAY APPROACH THE FORECAST AREA FROM THE WEST BY
TUESDAY...HOWEVER THIS IS JUST BEYOND THE END OF THE FORECAST PERIOD
AND WILL ADJUST AS NECESSARY IN FUTURE UPDATES.
FORECAST INSTABILITY IS TOO LOW TO INCLUDE ANY THUNDER CHANCES IN
THE LONG TERM...THOUGH THE BEST SHOT LOOKS TO BE WITH POTENTIAL CFP
NEAR THE END OF THE FORECAST PERIOD EARLY NEXT WEEK.
BAKER
&&
.AVIATION...
18Z UPDATE...
PRIMARY CONCERN IS CHC FOR IFR CIGS AND SHRA LATE TONIGHT AND
WED MORNING. UNUSUAL WARM MOIST PATTERN WILL CONTINUE WITH CLOUDS
LIKELY TO PERSIST AHEAD OF FRONT. NOT A PATTERN FOR WIDESPREAD
PRECIP. SCT SHRA WILL REMAIN WEST OF MOST TAF SITES UNTIL 12Z.
COULD SEE IFR CIGS ASSOCD WITH PRECIP AND SOME RADIATIONAL COOLING
ABOVE MOIST LOW LEVELS PERSIST THROUGH 16Z OR SO. INSTABILITY WILL
BE NEAR ZERO SO NO THREAT FOR TSRA. FRONT WILL BECOME STATIONARY
ACROSS THE STATE WEDNESDAY SO SW TO WEST SFC WINDS WILL NOT BECOME
NW.
//ATL CONFIDENCE...18Z UPDATE...
MEDIUM CONFIDENCE ON IFR CIGS AND PRECIP PROBS WED MORNING.
HIGH CONFIDENCE ON ALL OTHER ELEMENTS.
SNELSON
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 53 68 50 57 / 40 50 30 20
ATLANTA 56 67 51 60 / 50 60 20 20
BLAIRSVILLE 51 63 44 55 / 60 60 20 20
CARTERSVILLE 53 66 48 61 / 60 60 20 20
COLUMBUS 55 74 54 69 / 30 30 10 20
GAINESVILLE 54 65 49 56 / 50 60 30 20
MACON 52 74 51 65 / 20 20 20 20
ROME 52 67 47 62 / 60 60 20 20
PEACHTREE CITY 51 67 48 62 / 50 60 20 20
VIDALIA 53 75 54 67 / 10 20 10 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SNELSON
LONG TERM....31
AVIATION...SNELSON
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1249 PM EST TUE DEC 4 2012
.SYNOPSIS...
ISSUED AT 306 AM EST TUE DEC 4 2012
A BROKEN LINE OF SHOWERS AHEAD OF A COLD FRONT IS MOVING ACROSS
LOWER MICHIGAN EARLY THIS MORNING. THE RAIN WILL MOVE OUT OF THE
AREA BY LATE MORNING. WE/LL SEE SOME SUNSHINE THIS AFTERNOON BUT
TEMPERATURES WILL BE MUCH COOLER THAN YESTERDAY. THERE IS A CHANCE
OF MIXED RAIN AND SNOW FROM THURSDAY THROUGH THE WEEKEND.
TEMPERATURES WILL BE NEAR NORMAL.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 306 AM EST TUE DEC 4 2012
FORECAST CONCERNS DEAL PCPN TRENDS THIS MORNING. OVERALL...THE
FORECAST HASN/T CHANGED MUCH.
REGIONAL RADAR SHOWS A BROKEN BAND OF SHOWERS STRETCHING FROM NRN
LAKE HURON SWWD TO NEAR ST LOUIS. THIS PCPN IS ALIGNED ALONG THE
COLD FRONT WHICH IS PUSHING THROUGH THE CWA ATTM. LATEST IR LOOP
SHOWS COOLING CLOUD TOPS OVER ILLINOIS. THIS IS LIKELY IN RESPONSE
TO A WAVE ON THE SRN PORTION OF THE FRONT. HRRR SUGGESTS WE/LL SEE A
LARGER AREA OF PCPN MOVE INTO THE SRN/SE CWA PRIOR TO SUNRISE AS THE
WAVE MOVES NEWD. THIS JUST APPEARS TO BE RAIN...LIGHTNING REMAINS
WELL SW OF THE GREAT LAKES. PCPN WILL END FROM NW TO SE THIS
AFTERNOON AS THE WAVE MOVES MOVES THROUGH.
A SECONDARY COLD FRONT WILL MOVE SEWD THROUGH LOWER MICHIGAN
TONIGHT. WE MAY BRIEFLY SEE A FEW SHSN DEVELOP ALONG THE LAKE SHORE
NORTH OF HOLLAND BUT THEY WON/T AMOUNT TO MUCH AND WILL QUICKLY FADE
BY WEDNESDAY MORNING AS CORE OF THE COLD AIR MOVES EAST. HIGH
PRESSURE WILL SETTLE OVER THE CWA WEDNESDAY.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 306 AM EST TUE DEC 4 2012
CHALLENGING FORECAST IN THE EXTENDED AS MODEL CONSISTENCY HAS
BEEN POOR THE LAST COUPLE DAYS HANDLING THE DETAILS OF AN INVERTED
TROUGH/SFC WAVE MOVING ALONG THE FRONT STALLED ACROSS THE OHIO
VALLEY...AND A MORE SIGNIFICANT STORM EARLY NEXT WEEK.
WENT WITH LOW CHANCE OR SLIGHT CHANCE POPS EARLY IN THE PERIOD WITH
LOW CONFIDENCE ON DETAILS OF WHEN AND WHERE BEST CHANCES FOR PRECIP
WITH BE. P-TYPE IS ALSO A TOUGH CALL AS THERMAL PROFILES SUGGEST MIX
NORTH AND RAIN SOUTH.
A HIGHER IMPACT EVENT IS EXPECTED NEXT WEEK AS STRONG UPPER TROUGH
MOVES INTO THE ROCKIES WITH SFC LOW FORMING OVER THE PLAINS AND
HEADING FOR LOWER MICHIGAN. AGAIN CONFIDENCE IS LOW ON TIMING DUE TO
MODEL DIFFERENCES AND INCONSISTENCY...BUT A MIXED PRECIP TO RAIN
THEN OVER TO SNOW SCENARIO IS POSSIBLE EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1249 PM EST TUE DEC 4 2012
VFR CONDITIONS PREVAIL ACROSS SOUTHWEST LOWER MICHIGAN AS OF
1730Z. THE COLD FRONT AND RAIN ASSOCIATED WITH IT ARE NOW OFF TO
THE EAST AND SOUTH OF THE AREA. DRIER AIR IS WORKING INTO
SOUTHWEST LOWER MICHIGAN. VFR CONDITIONS ARE EXPECTED INTO THE
EVENING HOURS AS THE MID AND HIGH CLOUDS SLOWLY CLEAR TO THE
SOUTHEAST.
FOCUS SHIFTS TOWARD COLDER AIR SLIDING IN ON NORTHWEST WINDS AND
THE CHANCE FOR MVFR CLOUDS DEVELOPING TONIGHT AS THE COLD AIR
RIDES OVER LAKE MICHIGAN. FEEL LAKE CLOUDS WILL DEVELOP AND PUSH
INTO KMKG THIS EVENING AND SWEEP SOUTH AND EAST WITH TIME. BY 07Z
OR SO...THE MVFR STRATOCUMULUS DECK SHOULD BE OVER ALL THE TAF
SITES. CEILINGS OVER AROUND 3000FT WILL PERSIST INTO THE MIDDAY
HOURS OF WEDNESDAY. AT THIS POINT THE MOISTURE LOOKS TO SHALLOW
FOR ANY SNOW SHOWER ACTIVITY.
&&
.MARINE...
ISSUED AT 306 AM EST TUE DEC 4 2012
COLD ADVECTION WILL INCREASE WAVE HEIGHTS TODAY INTO WEDNESDAY. WE
EXTENDED THE SCA THROUGH THE AFTERNOON WEDNESDAY.
&&
.HYDROLOGY...
ISSUED AT 306 AM EST TUE DEC 4 2012
NO HYDRO ISSUES THIS MORNING QPF LESS THAN A QUARTER INCH IS
EXPECTED FROM SHOWERS ALONG THE COLD FRONT THIS MORNING.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 5 PM EST WEDNESDAY FOR LMZ844>849.
&&
$$
SYNOPSIS...93
SHORT TERM...93
LONG TERM...OSTUNO
AVIATION...DUKE
HYDROLOGY...93
MARINE...93
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
ISSUED BY NATIONAL WEATHER SERVICE NORTH PLATTE NE
1042 AM MST TUE DEC 4 2012
&&
.AVIATION...
VFR CONDITIONS EXPECTED THROUGH THE 18Z TAF FORECAST
CYCLE. HOWEVER...GUSTY SOUTHWEST /210-240/ SFC WINDS WILL CONTINUE
AT KGCC WITH GUST POTENTIAL AT OR ABOVE 20KTS THIS AFTERNOON. MODEL
GUIDANCE INDICATES A BRIEF PERIOD OF LIGHTER WINDS AT KGCC THIS
EVENING...BUT INCREASE ONCE AGAIN OVERNIGHT WITH 15KTS OR GREATER
AT THE TERMINAL. AT KRAP...LESSER WINDS EXPECTED....WITH
SOUTHERLY PEAK GUST POTENTIAL AT OR SLIGHTLY ABOVE 15 KTS THIS
AFTERNOON...THEN LIGHT AND VARIABLE OVERNIGHT.
&&
.UPDATE...MADE SOME MINOR CHANGES TO THE ONGOING FCST...MAINLY TO
DELAY THE ONSET OF CLOUDINESS THIS AFTERNOON BASED ON UPSTREAM
SATELLITE IMAGERY. BASED ON THE 12Z UNR RAOB AND MIXED H85 TEMPS...HIGHS
THIS AFTERNOON SHOULD BE AROUND 50 FOR RAPID CITY. H85 TEMPS IN THE
LATEST RUC AND NAM SOLNS INCREASE AROUND A DEGREE OR TWO THIS
AFTERNOON...SO HIGHS IN THE LOWER 50S SEEM PLAUSIBLE FOR RAPID CITY.
WITH HIGH CLOUDINESS HOLDING OFF UNTIL THE MID AFTERNOON HOURS...ITS
EFFECTS ON HIGHS ARE EXPECTED TO BE NEGLIGIBLE SO MIXED TEMPS WILL BE
UTILIZED IN THE FCST. WINDS THIS AFTERNOON WILL SHIFT TO THE SOUTH
AS HIGH PRESSURE BUILDS INTO EASTERN NORTH DAKOTA AND NORTHWESTERN
MN.
PREV DISCUSSION... /ISSUED 316 AM MST MON DEC 3 2012/
DISCUSSION...CURRENT SURFACE ANALYSIS SHOWS HIGH PRESSURE OVER THE
CENTRAL ROCKIES. LOW PRESSURE IS OVER SOUTHWESTERN ONTARIO...WITH A
COLD FRONT STRETCHING ACROSS NORTHERN MN...ND...AND NORTHEASTERN MT.
UPPER LEVEL ANALYSIS SHOWS WEAK RIDGING OVER THE NORTHERN
ROCKIES...WITH LOW REMAINING OFF THE PACIFIC NW COAST. SKIES ARE
MOSTLY CLEAR ACROSS THE AREA WITH TEMPS IN THE MID 20S TO MID 30S.
WINDS ARE LIGHT FROM THE WEST TO SOUTHWEST.
MILD AND DRY CONDITIONS WILL CONTINUE THROUGH WEDNESDAY...WITH
HIGHS 20 TO 25 DEGREES ABOVE AVERAGE ON WEDNESDAY. A COLD FRONT
WILL MOVE THROUGH THE AREA WEDNESDAY NIGHT...BRINGING TEMPS BACK
TO MORE NORMAL LEVELS FOR THE END OF THE WEEK. A BROAD UPPER TROF
WILL THEN SLOWLY SETTLE OVER THE AREA LATE IN THE WEEK..,BRINGING
UNSETTLED WEATHER THROUGH THE WEEKEND AND KEEPING TEMPS ON THE
COLD SIDE.
FOR TODAY...SKIES WILL START OFF MAINLY SUNNY...WITH INCREASING
MID AND HIGH CLOUDINESS FROM WEST TO EAST DURING THE DAY. THE WEAK
COLD FRONT TO THE NORTH WILL SINK SLOWLY SOUTH AND WEST DURING THE
DAY...STALLING OUT ALONG OR JUST EAST OF THE BLACK HILLS BY LATE
TODAY. HIGHS WILL RANGE FROM THE MID 40S OVER THE HIGHER BLACK
HILLS AND THE LEMMON AREA...TO THE MID 50S OVER MUCH OF
SOUTHWESTERN AND SOUTH CENTRAL SD. SOUTHWESTERLY WINDS WILL
INCREASE ACROSS NORTHEASTERN WY AND PORTIONS OF THE BLACK
HILLS...BECOMING BREEZY AT TIMES ACROSS CAMPBELL CO...ESPECIALLY
SOUTHERN CAMPBELL CO. EAST OF THE BLACK HILLS...WINDS WILL SWITCH
OVER TO THE SOUTHEAST DURING THE AFTERNOON. SKIES WILL BE PARTLY
CLOUDY IN GENERAL TONIGHT WITH LOWS MOSTLY IN THE 30S. WINDS WILL
REMAIN BREEZY AT TIMES ACROSS PORTIONS OF NORTHEASTERN WY AND THE
BLACK HILLS.
WEAK RIDGE TO THE WEST WILL PASS OVER THE AREA LATE TONIGHT AND
WEDNESDAY MORNING AS FRONTAL BOUNDARY PUSHES OFF TO THE EAST AS A
WARM FRONT. WEDNESDAY WILL BE THE MILDEST DAY OF THE WEEK...WITH
HIGHS MOSTLY IN THE UPPER 50S AND LOWER 60S. WINDS WILL BE
VARIABLE AS A WEAK SURFACE LOW DEVELOPS AND MOVES OVER THE AREA.
THE NEXT COLD FRONT WILL PASS THROUGH THE AREA WEDNESDAY NIGHT.
UPPER LEVEL ENERGY ACCOMPANYING THE FRONT LOOKS TO BE RELATIVELY
WEAK...BUT ISOLATED TO SCATTERED SHOWERS ARE EXPECTED
OVERNIGHT...MOSTLY IN THE FORM OF RAIN...AS COLDER AIR IS SLOW TO
PUSH IN BEHIND THE FRONT. LOWS WILL MOSTLY BE IN THE 30S.
THURSDAY LOOKS TO BE MAINLY CLOUDY AND COOL...WITH TEMPS NOT
RISING MUCH. WILL GO WITH HIGHS IN THE MID 30S TO MID 40S FOR NOW.
WEAK SHORTWAVE ENERGY PASSING ACROSS THE AREA WILL BRING A
CONTINUED CHANCE FOR MOSTLY LIGHT RAIN AND SNOW SHOWERS. A
STRONGER WAVE IS PROGGED TO PASS OVER THE AREA THURSDAY NIGHT INTO
FRIDAY. THIS ONE HAS THE POTENTIAL TO BRING AT LEAST A LIGHT
ACCUMULATION OF SNOW TO A GOOD PORTION OF THE AREA. VARIOUS MEDIUM
RANGE MODELS STILL DIFFER ON TIMING AND TRACK OF WAVE...AND WHERE
BETTER SNOW POTENTIAL WILL BE...SO WILL GO WITH CHANCE POPS FOR
NOW ACROSS MUCH OF THE CWA.
EXTENDED...THE MEDIUM RANGE MODELS CONTINUE TO SHOW A MAJOR CHANGE
TO COLD UNSETTLED WEATHER FROM THE END OF THE WEEK THROUGH THE
WEEKEND. A BROAD TROUGH DEVELOPING OVER THE NORTH CENTRAL U.S. WILL
OPEN THE WAY FOR ARCTIC AIR TO POUR INTO THE NORTHERN PLAINS. THE
JET STREAM WILL ALSO DROP INTO THE CENTRAL PLAINS ALLOWING ANOTHER
COLD FRONT TO CROSS THE REGION ON FRIDAY...AND CARRY ADDITIONAL
UPPER LEVEL SYSTEMS THROUGH THE DAKOTAS SATURDAY AND SUNDAY. A BRIEF
WARMING TREND IS EXPECTED FOR THE FIRST COUPLE OF DAYS NEXT WEEK
AFTER THE COLD AIRMASS MOVES EAST.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...WFO UNR/LBF
LONG TERM....WFO UNR/LBF
AVIATION...JACOBS
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
ISSUED BY THE NATIONAL WEATHER SERVICE NORTH PLATTE NE
1010 AM CST TUE DEC 4 2012
.UPDATE...MADE SOME MINOR CHANGES TO THE ONGOING FCST...MAINLY TO
DELAY THE ONSET OF CLOUDINESS THIS AFTERNOON BASED ON UPSTREAM
SATELLITE IMAGERY. BASED ON THE 12Z UNR RAOB AND MIXED H85 TEMPS...HIGHS
THIS AFTERNOON SHOULD BE AROUND 50 FOR RAPID CITY. H85 TEMPS IN THE
LATEST RUC AND NAM SOLNS INCREASE AROUND A DEGREE OR TWO THIS
AFTERNOON...SO HIGHS IN THE LOWER 50S SEEM PLAUSIBLE FOR RAPID CITY.
WITH HIGH CLOUDINESS HOLDING OFF UNTIL THE MID AFTERNOON HOURS...ITS
EFFECTS ON HIGHS ARE EXPECTED TO BE NEGLIGIBLE SO MIXED TEMPS WILL BE
UTILIZED IN THE FCST. WINDS THIS AFTERNOON WILL SHIFT TO THE SOUTH
AS HIGH PRESSURE BUILDS INTO EASTERN NORTH DAKOTA AND NORTHWESTERN
MN.
.AVIATION UPDATE...FOR THE 18Z TAFS...VFR FLT CONDS ARE EXPECTED
OVER THE NEXT 24 HRS.
&&
.PREV DISCUSSION... /ISSUED 316 AM MST MON DEC 3 2012/
DISCUSSION...CURRENT SURFACE ANALYSIS SHOWS HIGH PRESSURE OVER THE
CENTRAL ROCKIES. LOW PRESSURE IS OVER SOUTHWESTERN ONTARIO...WITH A
COLD FRONT STRETCHING ACROSS NORTHERN MN...ND...AND NORTHEASTERN MT.
UPPER LEVEL ANALYSIS SHOWS WEAK RIDGING OVER THE NORTHERN
ROCKIES...WITH LOW REMAINING OFF THE PACIFIC NW COAST. SKIES ARE
MOSTLY CLEAR ACROSS THE AREA WITH TEMPS IN THE MID 20S TO MID 30S.
WINDS ARE LIGHT FROM THE WEST TO SOUTHWEST.
MILD AND DRY CONDITIONS WILL CONTINUE THROUGH WEDNESDAY...WITH
HIGHS 20 TO 25 DEGREES ABOVE AVERAGE ON WEDNESDAY. A COLD FRONT
WILL MOVE THROUGH THE AREA WEDNESDAY NIGHT...BRINGING TEMPS BACK
TO MORE NORMAL LEVELS FOR THE END OF THE WEEK. A BROAD UPPER TROF
WILL THEN SLOWLY SETTLE OVER THE AREA LATE IN THE WEEK..,BRINGING
UNSETTLED WEATHER THROUGH THE WEEKEND AND KEEPING TEMPS ON THE
COLD SIDE.
FOR TODAY...SKIES WILL START OFF MAINLY SUNNY...WITH INCREASING
MID AND HIGH CLOUDINESS FROM WEST TO EAST DURING THE DAY. THE WEAK
COLD FRONT TO THE NORTH WILL SINK SLOWLY SOUTH AND WEST DURING THE
DAY...STALLING OUT ALONG OR JUST EAST OF THE BLACK HILLS BY LATE
TODAY. HIGHS WILL RANGE FROM THE MID 40S OVER THE HIGHER BLACK
HILLS AND THE LEMMON AREA...TO THE MID 50S OVER MUCH OF
SOUTHWESTERN AND SOUTH CENTRAL SD. SOUTHWESTERLY WINDS WILL
INCREASE ACROSS NORTHEASTERN WY AND PORTIONS OF THE BLACK
HILLS...BECOMING BREEZY AT TIMES ACROSS CAMPBELL CO...ESPECIALLY
SOUTHERN CAMPBELL CO. EAST OF THE BLACK HILLS...WINDS WILL SWITCH
OVER TO THE SOUTHEAST DURING THE AFTERNOON. SKIES WILL BE PARTLY
CLOUDY IN GENERAL TONIGHT WITH LOWS MOSTLY IN THE 30S. WINDS WILL
REMAIN BREEZY AT TIMES ACROSS PORTIONS OF NORTHEASTERN WY AND THE
BLACK HILLS.
WEAK RIDGE TO THE WEST WILL PASS OVER THE AREA LATE TONIGHT AND
WEDNESDAY MORNING AS FRONTAL BOUNDARY PUSHES OFF TO THE EAST AS A
WARM FRONT. WEDNESDAY WILL BE THE MILDEST DAY OF THE WEEK...WITH
HIGHS MOSTLY IN THE UPPER 50S AND LOWER 60S. WINDS WILL BE
VARIABLE AS A WEAK SURFACE LOW DEVELOPS AND MOVES OVER THE AREA.
THE NEXT COLD FRONT WILL PASS THROUGH THE AREA WEDNESDAY NIGHT.
UPPER LEVEL ENERGY ACCOMPANYING THE FRONT LOOKS TO BE RELATIVELY
WEAK...BUT ISOLATED TO SCATTERED SHOWERS ARE EXPECTED
OVERNIGHT...MOSTLY IN THE FORM OF RAIN...AS COLDER AIR IS SLOW TO
PUSH IN BEHIND THE FRONT. LOWS WILL MOSTLY BE IN THE 30S.
THURSDAY LOOKS TO BE MAINLY CLOUDY AND COOL...WITH TEMPS NOT
RISING MUCH. WILL GO WITH HIGHS IN THE MID 30S TO MID 40S FOR NOW.
WEAK SHORTWAVE ENERGY PASSING ACROSS THE AREA WILL BRING A
CONTINUED CHANCE FOR MOSTLY LIGHT RAIN AND SNOW SHOWERS. A
STRONGER WAVE IS PROGGED TO PASS OVER THE AREA THURSDAY NIGHT INTO
FRIDAY. THIS ONE HAS THE POTENTIAL TO BRING AT LEAST A LIGHT
ACCUMULATION OF SNOW TO A GOOD PORTION OF THE AREA. VARIOUS MEDIUM
RANGE MODELS STILL DIFFER ON TIMING AND TRACK OF WAVE...AND WHERE
BETTER SNOW POTENTIAL WILL BE...SO WILL GO WITH CHANCE POPS FOR
NOW ACROSS MUCH OF THE CWA.
EXTENDED...THE MEDIUM RANGE MODELS CONTINUE TO SHOW A MAJOR CHANGE
TO COLD UNSETTLED WEATHER FROM THE END OF THE WEEK THROUGH THE
WEEKEND. A BROAD TROUGH DEVELOPING OVER THE NORTH CENTRAL U.S. WILL
OPEN THE WAY FOR ARCTIC AIR TO POUR INTO THE NORTHERN PLAINS. THE
JET STREAM WILL ALSO DROP INTO THE CENTRAL PLAINS ALLOWING ANOTHER
COLD FRONT TO CROSS THE REGION ON FRIDAY...AND CARRY ADDITIONAL
UPPER LEVEL SYSTEMS THROUGH THE DAKOTAS SATURDAY AND SUNDAY. A BRIEF
WARMING TREND IS EXPECTED FOR THE FIRST COUPLE OF DAYS NEXT WEEK
AFTER THE COLD AIRMASS MOVES EAST.
&&
.AVIATION...12Z TAFS
VFR CONDITIONS EXPECTED THROUGH THIS AFTERNOON.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...26
LONG TERM....CARPENTER
AVIATION...CARPENTER
UPDATE...NWS LBF
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1037 AM PST Tue Dec 4 2012
.SYNOPSIS...
A strong and moist storm system will deliver widespread valley
rain and mountain snow to all areas today. The snow could be locally
heavy near the north Cascades and over the highest mountains
elsewhere. The remainder of the week will be cooler and
showery...with a series of weak weather disturbances moving
through the Inland Northwest.
&&
.DISCUSSION...
A tricky update tot he forecast this morning as precipitation
looks to redevelop over the southeastern portion of the region,
but dry over the extreme northwest portion of the region. The
tricky part is forecasting where this line of wet versus dry will
actually set up. The HRRR model is doing the best with where we
are currently seeing precipitation this morning. This guidance is
suggesting that precipitation will become more widespread after
noon today. Precipitation looks to remain east of a line from
Moses Lake to Omak and up along the Cascade crest. Best chances
will be across extreme eastern Washington and into the Idaho
Panhandle. This precipitation will continue through tonight and
taper off by Wednesday morning.
Snow levels are expect to rise up around 5500 feet around Stevens
Pass to around 4000 feet near the Canadian border this afternoon.
This will result in rain for Stevens Pass. Loup Loup Pass may see
a mix of some light rain and snow, but Blewett Pass will remain
dry or see some light rainfall this afternoon as well. Web cams
show all these passes transitioning from being snow covered to
just wet pavement. Seeing that we will continue with strong
westerly flow and much of the moisture remaining south of the
area, we will go ahead and cancel the Winter Weather Advisory for
the Cascades with this forecast update. /SVH
&&
.AVIATION...
18Z TAFS: Rain and mountain snow across the region has tapered off
a bit this morning as drier air aloft moved across the region.
However, another slug of moisture is beginning to ride up into the
region from the southwest. This will result in precipitaiton
becoming more widespread this afternoon into tonight. Rainfall is
expected at KGEG, KSFF, KCOE, KPUW and KLWS through early
Wednesday morning; KMWH will be on the western fringe of this
moisture. Low level moisture will keep cigs down through tonight
with IFR/MVFR conditions expected to continue at most terminals.
Winds are expected to become a little breezy overnight as low
levels become a bit more unstable. This should begin to break up
the stratus Wednesday morning as drier air aloft is mixed down
toward the surface. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 45 39 41 28 35 26 / 60 80 10 10 60 70
Coeur d`Alene 45 39 40 28 35 25 / 70 90 40 10 70 80
Pullman 46 40 42 29 37 28 / 90 90 40 10 50 60
Lewiston 52 45 48 33 45 31 / 60 90 30 10 30 60
Colville 44 41 41 30 36 25 / 30 80 20 30 70 70
Sandpoint 42 39 39 28 34 25 / 70 90 50 30 80 90
Kellogg 42 37 37 30 33 25 / 100 100 50 20 80 90
Moses Lake 49 40 45 26 37 25 / 20 20 0 10 10 20
Wenatchee 45 37 44 27 38 26 / 20 20 0 10 40 20
Omak 43 36 40 25 35 21 / 20 20 10 10 40 20
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$