Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 12/02/12
AREA FORECAST DISCUSSION
NWS NEW YORK NY
948 PM EST SAT DEC 1 2012
.SYNOPSIS...
A WARM FRONT WILL APPROACH OVERNIGHT...AND MOVE ACROSS THE AREA ON
SUNDAY. A WEAKENING COLD FRONT WILL MOVE THROUGH SUNDAY
NIGHT...FOLLOWED BY HIGH PRESSURE SLIDING ACROSS FROM THE WEST ON
MONDAY. A WARM FRONT WILL APPROACH MONDAY NIGHT...AND LIFT TO THE
NORTHEAST ON TUESDAY. A COLD FRONT WILL APPROACH TUESDAY
NIGHT...AND PASS THROUGH LATE TUESDAY NIGHT OR WEDNESDAY MORNING.
HIGH PRESSURE WILL FOLLOW FOR LATER WEDNESDAY THROUGH FRIDAY
MORNING. ANOTHER COLD FRONT AND POSSIBLE WAVE OF LOW PRESSURE WILL
APPROACH LATER FRIDAY INTO SATURDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
WITH COLD AIR DAMMING HOLDING TEMPS ACROSS MOST OF THE INTERIOR AT
OR JUST BELOW FREEZING...AND VSBYS DROPPING TO BELOW 2 MILES
ESPECIALLY IN ORANGE COUNTY...THE HIGHER ELEVATIONS OF SOUTHERN
CT AND THE CT RIVER VALLEY...FREEZING DRIZZLE AND/OR FREEZING FOG
ARE LIKELY OCCURRING. WILL CONTINUE FREEZING RAIN ADVY UNTIL
MIDNIGHT. COMBO OF BIAS-ADJUSTED 21Z HRRR AND 23Z GFS LAMP APPEARS
TO BE HANDLING TEMPS BEST...AND THINK TEMPS WILL RISE VERY SLOWLY
ABOVE FREEZING IN THOSE PLACES BY MIDNIGHT. THE INTERIOR CT RIVER
VALLEY AND ORANGE COUNTY MAY HOLD ONTO THE COLD AIR THE
LONGEST...AND THE ADVY THERE MAY EVENTUALLY NEED TO BE EXTENDED
OVERNIGHT.
EVENING LOWS CLOSER TO THE COAST AND IN NYC METRO SHOULD BE IN
THE UPPER 30S AND LOWER 40S...WITH SLOWLY RISING TEMPS OVERNIGHT.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
FOR SUNDAY...THE WARM FRONT SHOULD BE EXITING TO THE NORTHEAST OUT
OF THE REGION...LEAVING THE REGION IN THE WARM SECTOR. THERE IS
SOME UNCERTAINTY WHEN THE FRONT WILL MOVE NORTHEAST OUT OF THE
REGION...WHETHER IN THE MORNING OR DELAYED UNTIL AFTERNOON.
LIGHT WINDS WILL EVENTUALLY TURN SOUTHWEST...WITH WARM AIR
ADVECTION AS WINDS VEER FROM LOW TO MID LEVELS. USED A
MAV/MET/NAM12 BLEND FOR HIGHS WHICH WILL BE WELL INTO THE 50S.
HOWEVER...NEXT COLD FRONT WILL BE APPROACHING WITH CLOUDS
INCREASING AHEAD OF IT. THE MODELS INCLUDING THE SREF FOCUS ON THE
WESTERN END OF THE FORECAST REGION WITH RAIN SHOWERS TOWARDS THE
END OF THE AFTERNOON. THESE WILL SPREAD ACROSS THE REMAINDER OF
THE REGION THROUGH THE NIGHT...TAPERING OFF LATE FOR EASTERN
SECTIONS. THE FRONT WILL NOT BE THAT STRONG AS FLOW ALOFT REMAINS
QUASI ZONAL WITH MOST POSITIVE VORTICITY ADVECTION TO THE NORTH.
WITH SHOWERS IN THE AREA...ALSO USED NAM12 IN COMBINATION WITH MAV
AND MET FOR LOWS SUNDAY NIGHT.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
AS AN AMPLIFYING UPPER TROUGH/WEAKLY CLOSED LOW MOVES QUICKLY ACROSS
CENTRAL CANADA...DOWNSTREAM RIDGING WILL ALSO AMPLIFY AND BRING MILD
CONDITIONS MON-TUE...WITH HIGHS 55-60 ON MON AND 60-65 ON TUE.
A COLD FRONT WILL MOVE THROUGH LATE TUE NIGHT INTO EARLY WED MORNING
ACCOMPANIED BY A BAND OF SHOWERS...WITH LIKELY POP FORECAST MAINLY
DUE TO CLOSE MODEL AGREEMENT ON DETAILS SO FAR OUT IN TIME.
ACCEPTED THE TIMING OF THE ECMWF AND GEFS MEAN WHICH IS A LITTLE
QUICKER THAN THAT OF THE OPERATIONAL GFS...SO THE FRONT SHOULD CLEAR
AREAS FROM NYC NORTH/WEST BY DAYBREAK WED...THEN LONG ISLAND AND
SOUTHERN CT BY LATE MORNING ON WED.
AFTER THE COLD FROPA...DAYTIME TEMPS ON WED SHOULD REMAIN A LITTLE
ABOVE AVG...WITH HIGHS REACHED BY MIDDAY AND THEN FOLLOWED BY SLOWLY
FALLING TEMPS IN THE AFTERNOON. TEMPS SHOULD DROP TO NEAR OR
SLIGHTLY BELOW AVG WED NIGHT THROUGH FRI NIGHT AS CANADIAN HIGH
PRESSURE SLIDES ACROSS.
THE FLOW ALOFT ACROSS THE LOWER 48 SHOULD BECOME ZONAL BY THU AS THE
SFC HIGH SLIDES ACROSS...WITH A WEAK SPLIT AS ANOTHER UPPER LOW
SCOOTING ACROSS CENTRAL CANADA LATE THIS WEEK...AND A MID LEVEL SRN
DISTURBANCE TRAVERSES THE LOWER 48. THESE SHOULD COMBINE TO BRING
ANOTHER COLD FRONTAL APPROACH FROM LATE FRI INTO SAT...WITH THE SRN
STREAM DISTURBANCE INITIATING WEAK CYCLOGENESIS ALONG THE FRONT.
GFS IS MORE SUPPRESSED AND SLOWER THAN THE ECMWF WITH THIS
WAVE...WHICH MAY ALLOW STRONG HIGH PRESSURE OVER CENTRAL CANADA TO
NOSE INTO UPSTATE NY AND NORTHERN NEW ENGLAND ENOUGH TO SUPPLY LOW
LEVEL COLD AIR FOR SOME WINTRY PRECIP MAINLY WELL NORTH/WEST OF NYC
FRI NIGHT INTO EARLY SAT MORNING. EXPECT RAIN FOR THE BALANCE OF THE
DAY ON SAT...THEN A POSSIBLE MIX WITH SNOW AGAIN WELL NORTH/WEST SAT
EVENING AS THE SFC WAVE PULLS AWAY.
&&
.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
A STATIONARY FRONT SOUTH OF THE TERMINALS APPROACHES THE AREA
LATE AT NIGHT AS A WARM FRONT. THIS FRONT MOVES ACROSS THE AREA
SUNDAY.
CIGS MAINLY IFR (500 TO 1000 FT)...WITH A FEW LOCATIONS
DETERIORATING TO LIFR OVERNIGHT. PATCHY DZ POSSIBLE...WITH SOME
CONCERN FOR FREEZING DRIZZLE/FOG AT KSWF.
THERE ARE SOME INDICATIONS THAT CONDITIONS COULD IMPROVE
LATE...BUT USUALLY WHEN A WARM FRONT APPROACHES AT NIGHT...POOR
CONDITIONS WITH REGARD TO CIGS AND VSBY CAN BE EXPECTED...THUS THE
FORECAST OF AT LEAST IFR/LIFR.
ANY LOW CLOUDS AND FOG WILL TAKE SOME TIME SUNDAY MORNING TO SCOUR
OUT...WITH MVFR OR VFR POSSIBLE BY AFTERNOON. AS ALWAYS WITH
FORECASTING STRATUS...TRENDS WILL NEED TO BE WATCHED CLOSELY AND
WILL LIKELY BE OFF BY A COUPLE OF HOURS.
ANY RETURN TO VFR CONDITIONS SUNDAY AFTERNOON WILL BE SHORT LIVED
AS A FRONT APPROACHES LATE IN THE DAY. WEAK SUN AND SHORT DAYS
COULD LEAD TO A RETURN OF STRATUS BY LATE AFTERNOON.
NORTHEAST WINDS LIGHTEN AND BECOME VARIABLE AFTER MIDNIGHT. WINDS
SHIFT TO THE SOUTH AFTER SUNRISE...AND SHOULD INCREASE TO 5 TO 10
KT DURING THE AFTERNOON (AROUND 10 KT AT NYC METRO TERMINALS).
.OUTLOOK FOR 00Z MONDAY THROUGH THURSDAY...
.SUN NIGHT...CIGS BELOW 3000FT LIKELY.
.MONDAY...CHC CIGS BELOW 3000FT EARLY...THEN VFR.
.TUESDAY...VFR. CHC SW GUSTS TO 20 KT.
.TUESDAY NIGHT...CHC CIGS BELOW 3000FT IN SHOWERS.
.WEDNESDAY...RETURN TO VFR. CHC GUSTS 20-25 KT.
.THURSDAY...VFR.
&&
.MARINE...
NE FLOW 15-20 KT AHEAD OF A WARM FRONT TO THE SOUTH...PLUS
INCOMING E SWELL UP TO 3 FT...ARE KEEPING OCEAN SEAS ABOVE 5
FT...SO SCA HAS BEEN EXTENDED PER COLLAB WITH SURROUNDING OFFICES.
A BRIEF PERIOD OF SUB SCA CONDITIONS EXPECTED ON SUNDAY AS THE
PRESSURE GRADIENT WEAKENS. MARGINAL SCA EXPECTED AGAIN SUNDAY
EVENING WITH 5 FT OCEAN SEAS RETURNING. THESE CONDITIONS SHOULD
CONTINUE SUNDAY NIGHT WITH THE COLD FRONTAL PASSAGE.
QUIET CONDS EXPECTED MON THROUGH TUE AFTERNOON VIA WEAK HIGH
PRESSURE. INCREASING S-SW FLOW AHEAD OF AN APPROACHING COLD FRONT
COULD BUILD OCEAN SEAS ABOVE SCA LEVELS TUE NIGHT...WITH
POST-FRONTAL NW FLOW ALSO MAINTAINING OCEAN SCA INTO WED AFTERNOON
OR EVENING. QUIET AGAIN ON THU AS HIGH PRESSURE BUILDS.
&&
.HYDROLOGY...
FOR TONIGHT...ONLY EXPECTING AT MOST A HUNDREDTH OF AN INCH IN
LIQUID. FOR LATE SUNDAY AFTERNOON THROUGH SUNDAY NIGHT...AROUND A
TENTH OF AN INCH OR LESS OF QPF. NO HYDROLOGIC IMPACTS EXPECTED.
&&
.EQUIPMENT...
KOKX WSR-88D IS OUT OF SERVICE DUE TO A MAJOR NON STORM RELATED
MECHANICAL FAILURE. OSF RADAR OPERATIONS CENTER TECHS HAVE
ARRIVED TO BEGIN WORK...AND THE RADAR IS EXPECTED TO RETURN TO
SERVICE BY THE FIRST WEEK OF DECEMBER.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...FREEZING RAIN ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR
CTZ005>007.
NY...FREEZING RAIN ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR NYZ067.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 AM EST SUNDAY FOR ANZ350-353-355.
&&
$$
SYNOPSIS...JM
NEAR TERM...GOODMAN
SHORT TERM...JM
LONG TERM...GOODMAN
AVIATION...PW
MARINE...GOODMAN/JM
HYDROLOGY...GOODMAN/JM
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS NEW YORK NY
737 PM EST SAT DEC 1 2012
.SYNOPSIS...
A WARM FRONT WILL APPROACH TONIGHT...AND MOVE ACROSS ON SUNDAY. A
WEAKENING COLD FRONT WILL MOVE THROUGH SUNDAY NIGHT...FOLLOWED BY
HIGH PRESSURE SLIDING ACROSS FROM THE WEST ON MONDAY. A WARM
FRONT WILL APPROACH MONDAY NIGHT...AND LIFT TO THE NORTHEAST ON
TUESDAY. A COLD FRONT WILL APPROACH TUESDAY NIGHT...AND PASS
THROUGH LATE TUESDAY NIGHT OR WEDNESDAY MORNING. HIGH PRESSURE
WILL FOLLOW FOR LATER WEDNESDAY THROUGH FRIDAY MORNING. ANOTHER
COLD FRONT AND POSSIBLE WAVE OF LOW PRESSURE WILL APPROACH LATER
FRIDAY INTO SATURDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
WITH COLD AIR DAMMING HOLDING TEMPS ACROSS MOST OF THE INTERIOR AT
OR JUST BELOW FREEZING...AND VSBYS DROPPING TO BELOW 2 MILES
ESPECIALLY IN ORANGE COUNTY...THE HIGHER ELEVATIONS OF SOUTHERN
CT AND THE CT RIVER VALLEY...FREEZING DRIZZLE AND/OR FREEZING FOG
ARE LIKELY OCCURRING AND DECIDED TO ISSUE FREEZING RAIN ADVY UNTIL
MIDNIGHT. COMBO OF BIAS-ADJUSTED 21Z HRRR AND 23Z GFS LAMP
APPEARS TO BE HANDLING TEMPS BEST...AND THINK TEMPS WILL RISE VERY
SLOWLY ABOVE FREEZING IN THOSE PLACES BY MIDNIGHT. THE INTERIOR
CT RIVER VALLEY AND ORANGE COUNTY MAY HOLD ONTO THE COLD AIR THE
LONGEST...AND THE ADVY THERE MAY EVENTUALLY NEED TO BE EXTENDED
OVERNIGHT.
EVENING LOWS CLOSER TO THE COAST AND IN NYC METRO SHOULD BE IN
THE UPPER 30S AND LOWER 40S...WITH SLOWLY RISING TEMPS OVERNIGHT.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
FOR SUNDAY...THE WARM FRONT SHOULD BE EXITING TO THE NORTHEAST OUT
OF THE REGION...LEAVING THE REGION IN THE WARM SECTOR. THERE IS
SOME UNCERTAINTY WHEN THE FRONT WILL MOVE NORTHEAST OUT OF THE
REGION...WHETHER IN THE MORNING OR DELAYED UNTIL AFTERNOON.
LIGHT WINDS WILL EVENTUALLY TURN SOUTHWEST...WITH WARM AIR
ADVECTION AS WINDS VEER FROM LOW TO MID LEVELS. USED A
MAV/MET/NAM12 BLEND FOR HIGHS WHICH WILL BE WELL INTO THE 50S.
HOWEVER...NEXT COLD FRONT WILL BE APPROACHING WITH CLOUDS
INCREASING AHEAD OF IT. THE MODELS INCLUDING THE SREF FOCUS ON THE
WESTERN END OF THE FORECAST REGION WITH RAIN SHOWERS TOWARDS THE
END OF THE AFTERNOON. THESE WILL SPREAD ACROSS THE REMAINDER OF
THE REGION THROUGH THE NIGHT...TAPERING OFF LATE FOR EASTERN
SECTIONS. THE FRONT WILL NOT BE THAT STRONG AS FLOW ALOFT REMAINS
QUASI ZONAL WITH MOST POSITIVE VORTICITY ADVECTION TO THE NORTH.
WITH SHOWERS IN THE AREA...ALSO USED NAM12 IN COMBINATION WITH MAV
AND MET FOR LOWS SUNDAY NIGHT.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
AS AN AMPLIFYING UPPER TROUGH/WEAKLY CLOSED LOW MOVES QUICKLY ACROSS
CENTRAL CANADA...DOWNSTREAM RIDGING WILL ALSO AMPLIFY AND BRING MILD
CONDITIONS MON-TUE...WITH HIGHS 55-60 ON MON AND 60-65 ON TUE.
A COLD FRONT WILL MOVE THROUGH LATE TUE NIGHT INTO EARLY WED MORNING
ACCOMPANIED BY A BAND OF SHOWERS...WITH LIKELY POP FORECAST MAINLY
DUE TO CLOSE MODEL AGREEMENT ON DETAILS SO FAR OUT IN TIME.
ACCEPTED THE TIMING OF THE ECMWF AND GEFS MEAN WHICH IS A LITTLE
QUICKER THAN THAT OF THE OPERATIONAL GFS...SO THE FRONT SHOULD CLEAR
AREAS FROM NYC NORTH/WEST BY DAYBREAK WED...THEN LONG ISLAND AND
SOUTHERN CT BY LATE MORNING ON WED.
AFTER THE COLD FROPA...DAYTIME TEMPS ON WED SHOULD REMAIN A LITTLE
ABOVE AVG...WITH HIGHS REACHED BY MIDDAY AND THEN FOLLOWED BY SLOWLY
FALLING TEMPS IN THE AFTERNOON. TEMPS SHOULD DROP TO NEAR OR
SLIGHTLY BELOW AVG WED NIGHT THROUGH FRI NIGHT AS CANADIAN HIGH
PRESSURE SLIDES ACROSS.
THE FLOW ALOFT ACROSS THE LOWER 48 SHOULD BECOME ZONAL BY THU AS THE
SFC HIGH SLIDES ACROSS...WITH A WEAK SPLIT AS ANOTHER UPPER LOW
SCOOTING ACROSS CENTRAL CANADA LATE THIS WEEK...AND A MID LEVEL SRN
DISTURBANCE TRAVERSES THE LOWER 48. THESE SHOULD COMBINE TO BRING
ANOTHER COLD FRONTAL APPROACH FROM LATE FRI INTO SAT...WITH THE SRN
STREAM DISTURBANCE INITIATING WEAK CYCLOGENESIS ALONG THE FRONT.
GFS IS MORE SUPPRESSED AND SLOWER THAN THE ECMWF WITH THIS
WAVE...WHICH MAY ALLOW STRONG HIGH PRESSURE OVER CENTRAL CANADA TO
NOSE INTO UPSTATE NY AND NORTHERN NEW ENGLAND ENOUGH TO SUPPLY LOW
LEVEL COLD AIR FOR SOME WINTRY PRECIP MAINLY WELL NORTH/WEST OF NYC
FRI NIGHT INTO EARLY SAT MORNING. EXPECT RAIN FOR THE BALANCE OF THE
DAY ON SAT...THEN A POSSIBLE MIX WITH SNOW AGAIN WELL NORTH/WEST SAT
EVENING AS THE SFC WAVE PULLS AWAY.
&&
.AVIATION /01Z SUNDAY THROUGH THURSDAY/...
A STATIONARY FRONT SOUTH OF THE TERMINALS THIS EVENING APPROACHES
THE AREA LATE AT NIGHT AS A WARM FRONT. THIS FRONT MOVES ACROSS
THE AREA SUNDAY.
CIGS MAINLY IFR TONIGHT (500 TO <1000 FT)...WITH A FEW LOCATIONS
DETERIORATING TO LIFR OVERNIGHT. PATCHY DZ POSSIBLE...WITH SOME
CONCERN FOR FREEZING DRIZZLE AT KSWF AT TIMES.
THERE ARE SOME INDICATIONS THAT CONDITIONS COULD IMPROVE
LATE...BUT USUALLY WHEN A WARM FRONT APPROACHES AT NIGHT...POOR
CONDITIONS WITH REGARD TO CIGS AND VSBY CAN BE EXPECTED...THUS THE
FORECAST OF AT LEAST IFR/LIFR.
ANY LOW CLOUDS AND FOG WILL TAKE SOME TIME SUNDAY MORNING TO SCOUR
OUT...WITH MVFR OR VFR POSSIBLE BY AFTERNOON. AS ALWAYS WITH
FORECASTING STRATUS...TRENDS WILL NEED TO BE WATCHED CLOSELY AND
WILL LIKELY BE OFF BY A COUPLE OF HOURS.
ANY RETURN TO VFR CONDITIONS SUNDAY AFTERNOON WILL BE SHORT LIVED
AS A FRONT APPROACHES LATE IN THE DAY. WEAK SUN AND SHORT DAYS
COULD LEAD TO A RETURN OF STRATUS BY LATE AFTERNOON.
NORTHEAST WINDS TONIGHT LIGHTEN AFTER MIDNIGHT. WINDS SHIFT TO THE
SOUTH AFTER SUNRISE...AND SHOULD INCREASE TO 5 TO 10 KT DURING
THE AFTERNOON (AROUND 10 KT AT NYC METRO TERMINALS).
.OUTLOOK FOR 00Z MONDAY THROUGH THURSDAY...
.SUN NIGHT...CIGS BELOW 3000FT LIKELY.
.MONDAY...CHC CIGS BELOW 3000FT EARLY...THEN VFR.
.TUESDAY...VFR. CHC SW GUSTS TO 20 KT.
.TUESDAY NIGHT...CHC CIGS BELOW 3000FT IN SHOWERS.
.WEDNESDAY...RETURN TO VFR. CHC GUSTS 20-25 KT.
.THURSDAY...VFR.
&&
.MARINE...
NE FLOW 15-20 KT AHEAD OF A WARM FRONT TO THE SOUTH...PLUS
INCOMING E SWELL UP TO 3 FT...ARE KEEPING OCEAN SEAS ABOVE 5
FT...SO SCA HAS BEEN EXTENDED UNTIL 03Z WEST AND 06Z EAST. BASED
ON LATEST TREND THESE MAY NEED TO BE EXTENDED FURTHER INTO THE
OVERNIGHT. A BRIEF PERIOD OF SUB SCA CONDITIONS EXPECTED ON SUNDAY
AS THE PRESSURE GRADIENT WEAKENS. MARGINAL SCA EXPECTED AGAIN
SUNDAY EVENING WITH 5 FT OCEAN SEAS RETURNING. THESE CONDITIONS
SHOULD CONTINUE SUNDAY NIGHT WITH THE COLD FRONTAL PASSAGE.
QUIET CONDS EXPECTED MON THROUGH TUE AFTERNOON VIA WEAK HIGH
PRESSURE. INCREASING S-SW FLOW AHEAD OF AN APPROACHING COLD FRONT
COULD BUILD OCEAN SEAS ABOVE SCA LEVELS TUE NIGHT...WITH
POST-FRONTAL NW FLOW ALSO MAINTAINING OCEAN SCA INTO WED AFTERNOON
OR EVENING. QUIET AGAIN ON THU AS HIGH PRESSURE BUILDS.
&&
.HYDROLOGY...
FOR TONIGHT...ONLY EXPECTING AT MOST A HUNDREDTH OF AN INCH IN
LIQUID. FOR LATE SUNDAY AFTERNOON THROUGH SUNDAY NIGHT...AROUND A
TENTH OF AN INCH OR LESS OF QPF. NO HYDROLOGIC IMPACTS EXPECTED.
&&
.EQUIPMENT...
KOKX WSR-88D IS OUT OF SERVICE DUE TO A MAJOR NON STORM RELATED
MECHANICAL FAILURE. OSF RADAR OPERATIONS CENTER TECHS HAVE
ARRIVED TO BEGIN WORK...AND THE RADAR IS EXPECTED TO RETURN TO
SERVICE BY THE FIRST WEEK OF DECEMBER.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...FREEZING RAIN ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR
CTZ005>007.
NY...FREEZING RAIN ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR NYZ067.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR ANZ353-
355.
SMALL CRAFT ADVISORY UNTIL 2 AM EST SUNDAY FOR ANZ350.
&&
$$
SYNOPSIS...JM
NEAR TERM...GOODMAN
SHORT TERM...JM
LONG TERM...GOODMAN
AVIATION...PW
MARINE...GOODMAN/JM
HYDROLOGY...GOODMAN/JM
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS TAUNTON MA
703 PM EST SAT DEC 1 2012
.SYNOPSIS...
A STRONG HIGH PRES WILL DRIFT ACROSS THE CANADIAN MARITIMES
TONIGHT. THIS COMBINED WITH AN APPROACHING WARM FRONT WILL RESULT
IN CLOUDS AND AREAS OF FREEZING DRIZZLE IN MANY INTERIOR AREAS
TONIGHT. THE WARM FRONT WILL MOVE NORTH OF THE REGION SUNDAY AND
USHER IN MUCH MILDER TEMPERATURES. A WEAK COLD FRONT WILL BRING
RAIN SHOWERS TO THE AREA SUNDAY EVENING...BUT TEMPERATURES WILL
REMAIN MILD INTO EARLY NEXT WEEK. A STRONGER COLD FRONT WILL BRING
ANOTHER CHANCE OF RAIN/SNOW SHOWERS WITH COOLER TEMPERATURES ON
WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
7 PM UPDATE...
WEAK NLY FLOW PREVAILS AT THE SFC KEEPING COLD AIR IN PLACE /COLD
AIR DAMMING/. PER VWP/S...S/SW FLOW PREVAILS AT H925-85. WILL SEE
CONTINUED OVERRUNNING OVER A SHALLOW COLD DOME AT THE SFC. LIGHT
FREEZING DRIZZLE IS EXPECTED AS THE MID-LVL DECK HAS DRIED /NO
ICE NUCLEI/. IN ADDITION...THE ABUNDANCE OF LOW-LVL MOISTURE
SUBSQUENT FROM EARLIER SNOWS WILL ALLOW FOR FREEZING FOG ACROSS
INTERIOR NEW ENGLAND.
WITHIN THOSE AREAS OF THE WINTER WX ADVISORY....STILL ANTICIPATING
VERY LIGHT AND MINOR ICE ACCUMULATIONS /A TRACE TO A COUPLE ONE-
HUNDREDTHS/ RESULTING IN SLICK SPOTS. WILL ALSO SEE SOME
SIGNIFICANT VSBY IMPACTS DOWN TO 1/4 OF A MILE OR LESS IN SPOTS.
WILL KEEP WITH THE PREVIOUS FORECAST BUT INSERT FREEZING FOG CHCS.
AT OR BELOW FREEZING TEMPS WILL CONTINUE INTO THE EARLY MORNING
HOURS. THUS FAR THE WRF-ARW AND HRRR ARE THE BEST NEAR- TO SHORT-
TERM GUIDANCE IN HANDLING SFC TEMPS...KEEPING STEADY TEMPS THE
NEXT SEVERAL HRS...SLOWLY RISING INTO THE MORNING PD /REMAINING
ABOVE FREEZING FOR COASTAL LOCALES/.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
LOOKS LIKE ENOUGH LOW LEVEL WIND PUSH TO BRING WARM FRONT THROUGH
SNE DURING MORNING HOURS AND ALLOW TEMPS TO RISE INTO THE 50S
ACROSS MOST OF THE REGION ON SUNDAY. SHORT WAVE AND TROF AND WEAK
COLD FRONT WITH PACIFIC AIR BEHIND APPROACHES VERY LATE SUN
AFTERNOON IN THE WEST AND THEN CROSSES MUCH OF THE FORECAST AREA
DURING THE EVENING HOURS...MOVING OFF THE COAST DURING THE MONDAY
EARLY MORNING HOURS. WENT HIGH CHANCE TO LOW LIKELY POPS MOST OF
THE AREA. EXPECT AMOUNTS TO GENERALLY BE AROUND A TENTH OF AN INCH
OR LESS. TEMPS SHOULD REMAIN ABOVE FREEZING THROUGHOUT SUN
NIGHT...AND NO PTYPE ISSUES ARE ENVISIONED.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
HIGHLIGHTS...
* WARMING TREND MONDAY INTO TUESDAY WITH ABOVE-AVERAGE HIGHS
* A RAIN-TO-SNOW DISTURBANCE IS EXPECTED TUE NGT INTO WED NGT
* SEASONABLE WEATHER RETURNS FOR THE END OF THE WEEK
* UNCERTAINTY PREVAILS...BUT A WEEKEND DISTURBANCE IS EXPECTED
DISCUSSION...
LATEST DETERMINISTIC FCST GUIDANCE COUPLED WITH ATMOSPHERIC TELE-
CONNECTIONS ANTICIPATED FOR THE FIRST WEEK OF DECEMBER EMPHASIZE A
PROGRESSIVE FLOW PATTERN WITH SEASONABLE TEMPERATURES. SPECIFICALLY
THERE IS THE EXPECTATION FOR BRIEF WARM SPELLS PRIOR TO THE ONSET OF
PACIFIC-ORIGIN WEAK WEATHER DISTURBANCE BRINGING THE CHANCE OF RAIN
AND SNOW SHOWERS WITH MINOR ACCUMULATIONS...FOLLOWED BY HIGH PRES
WITH ACCOMPANYING AIRMASSES OF ARCTIC-ORIGIN. BUT THERE IS PERHAPS A
SHIFT TOWARDS THE MIDDLE OF DECEMBER OF A CONTINUED COLD BUT
STORMIER PATTERN AS THE PACIFIC-NORTH AMERICAN /PNA/ TREND SHIFTS
POSITIVE /PROMOTING ENHANCED TROUGHING OVER THE CENTRAL AND EASTERN
CONUS/ WITH THE NORTH AMERICAN OSCILLATION /NAO/ TRENDING NEAR-
NEUTRAL OR SLIGHTLY NEGATIVE...ALL WHILE THE ARCTIC OSCILLATION /AO/
REMAINS NEGATIVE. PURELY SPECULATIVE AT THIS TIME AND BEYOND THE
PRESENT LONG-TERM FCST.
MONDAY INTO MONDAY NIGHT...
SFC-MID LVL RIDGING BUILDS INTO NEW ENGLAND IN WAKE OF THE WEEKEND
DISTURBANCE. ANTICIPATE MOSTLY CLEAR CONDITIONS UNDER LIGHT W/NW
FLOW. A SUBSIDENCE INVERSION WILL KEEP MIXING LIMITED TO H95 WHERE
TEMPS WILL HOVER AROUND +8C...ALLOWING FOR MILD CONDITIONS AND MAX
TEMPS INTO THE MID-UPR 50S. SHOULD HIGH PRES AND CLEAR CONDITIONS
PREVAIL OVRNGT...THE CALM FLOW WILL ALLOW FOR EFFECTIVE NOCTURNAL
COOLING ALLOWING TEMPS TO DROP 20-30 DEGREES FROM DAYTIME HIGHS. BUT
IF MID-UPR LVL CLOUDS BUILD FROM THE SW AHEAD OF A MIDWEEK
DISTURBANCE...THEN COOLING TEMPS WILL BE LIMITED.
TUESDAY...
ABOVE-NORMAL TEMPS ARE EXPECTED BELOW THE CONTINUED SUBSIDENCE
INVERSION AND AHEAD OF A WEAK WX DISTURBANCE. S/SW FLOW WILL USHER
WARM AND MOIST AIR ALONG AND AHEAD OF A SFC COLD FRNT ANTICIPATED TO
SWEEP ACROSS NEW ENGLAND BY LATE WEDNESDAY. EXPECT INCREASING AND
LOWERING CLOUDS FOR TUESDAY WITH HIGHS GETTING CLOSE TO 60 FOR
LOCALES IN THE S CT VLY. WILL KEEP THE FCST PD DRY. WILL NEED TO BE
CONCERNED FOR FOG/LOW STRATUS ALONG THE CAPE AND ISLANDS AS HIGHER
DEWPOINT AIR SWEEPS N ACROSS THE COOLER OCEAN.
TUESDAY NIGHT INTO WEDNESDAY NIGHT...
THERE IS STILL SOME NOTABLE SPREAD CONCERNING THE EVOLUTION AND
STRENGTH OF THE A SERIES OF SHRTWV DISTURBANCES WITHIN AN OPEN-WAVE
TROUGH STRUCTURE ACROSS NEW ENGLAND. WHILE IT IS FAIRLY SUCCINCT
THAT AN ATTENDANT COLD FRNT WITH ANAFRONT CHARACTERISTICS WILL SWEEP
THROUGH THE FCST REGION EXITING AS LATE AS DUSK ON WEDNESDAY...
THERE ARE DISCREPANICES AS TO HOW QUICKLY COLD AIR WILL BUILD FROM
THE REAR RESULTING IN SHOWERS TO TRANSITION TO SNOW.
PRESENT THINKING IS THAT THE BETTER MOISTURE AVAILABILITY WILL BE
COLLOCATED WITHIN PROXIMITY OF THE SFC COLD FRNT AND WARMER AIR. A
LINE OF LIGHT TO MODERATE SHOWERS IS EXPECTED AS LIKELY LOW CLOUDS
AND FOG WILL IMPACT S/SE NEW ENGLAND /ESPECIALLY ALONG SHORELINES/.
HIGH PRES WITH COOLER AND DRIER AIR WILL BUILD TO THE REAR. WHILE
THERE IS THE UNCERTAINTY AS TO THE TIMING OF TRANSITION...THERE IS
GREATER CONFIDENCE THAT LATE WEDNESDAY INTO THE OVRNGT PD...REMNANT
SHRTWV ENERGY WILL FETCH MOISTURE OFF THE LAKES ALLOWING FOR THE
POSSIBILITY OF SCATTERED SNOW SHOWERS AND MINOR ACCUMULATIONS TO
STRETCH INTO SOUTHERN NEW ENGLAND.
S/SW WINDS WILL GUST UP TO 25 KTS ALONG AND AHEAD OF THE COLD FRNT
BACKING OUT OF THE W/NW AND GUSTING UP TO 30 KTS IN WAKE OF THE FRNT
ANTICIPATED WEDNESDAY AND CONTINUING INTO THURSDAY...GRADUALLY
WEAKENING.
THURSDAY INTO FRIDAY...
HIGH PRES DOMINATES...THE COLDER DAY OF WHICH WILL BE THURS WITH
HIGHS JUST BELOW SEASONABLE LVLS UNDER CLEARING CONDITIONS AND LIGHT
W/NWLY FLOW. NOCTURNAL COOLING MAY BE HINDERED OVRNGT SHOULD HIGH
PRES SHIFT E ALLOWING FOR RETURN S/SWLY FLOW AND THE POTENTIAL FOR
INCREASING MID-UPR LVL CLOUDS. WILL SEE CLOUDS ON THE INCREASE ON
FRIDAY UNDER CONTINUED S/SWLY FLOW AND SLIGHTLY WARMER HIGHS CLOSER
TO 50 DEGREES.
WEEKEND...
DETERMINISTIC FCST GUIDANCE KEYS ON A DISTURBANCE...BUT ITS EXACT
EVOLUTION WITH REGARDS TO THE SFC LOW REMAINS UNCERTAIN. THE
POSSIBILITY OF INTERIOR SNOWS WITH COASTAL RAINS IS PLAUSIBLE AS
COLD AIR OUT OF CANADA SEEMINGLY REMAINS IN PLACE.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
OVERVIEW...MODERATE CONFIDENCE.
HAVE FCST LOWERING CIGS WITH DETERIORATING VSBYS TO IFR-VLIFR FOR
INTERIOR TERMINALS...WHILE S/SE ALONG SHORELINES CONDITIONS SHOULD
REMAIN MVFR-VFR.
SHALLOW COLD AIR WITH THE ABUNDANCE OF LOW-LVL MOISTURE WILL MAKE
FOR -FZDZ AND FZFG FOR INTERIOR TERMINALS UNDER LIGHT WINDS. WILL
SEE GRADUAL IMPROVEMENT INTO THE MORNING PD...GRADUALLY LIFTING
INTO THE MIDDAY AND AFTN HRS. NOT ENTIRELY CONFIDENT ON TIMING OF
SPECIFICS...BUT FEEL PERSISTENCE OF THREATS IS WARRANTED.
A DISTURBANCE IS EXPECTED INTO LATE SUNDAY.
KBOS TAF...LOW TO MODERATE CONFIDENCE.
AM NOT CONFIDENT ON TIMING OF SPECIFICS...BUT CONFIDENT CONDITIONS
WILL DETERIORATE TO IFR-LIFR. WILL SEE IMPROVEMENT INTO THE MIDDAY
PD WITH THE APPROACHING SUNDAY DISTURBANCE.
KBDL TAF...LOW TO MODERATE CONFIDENCE.
WILL HOLD WITH PRESENT LIFR CONDITIONS INTO THE EARLY MORNING HRS
THEN GRADUALLY IMPROVING THEREAFTER. LOW CONFIDENCE ON TIMING OF
SPECIFICS...BUT AM NOT CONFIDENT CONDITIONS WILL IMPROVE WITH
LIGHT WINDS.
OUTLOOK...MONDAY THROUGH THURSDAY...
MONDAY INTO TUESDAY...MODERATE TO HIGH CONFIDENCE.
VFR WITH LIGHT W/NW WINDS VEERING OUT OF THE S/SW. VSBY CONCERNS
WITH FOG PSBL ALONG THE S/SE COASTLINE TERMINALS.
TUESDAY NIGHT INTO WEDNESDAY NIGHT...MODERATE CONFIDENCE.
COLD FRNT SWEEPS THRU THE TERMINALS TUE NGT INTO WED. MODEST S/SW
FLOW ALONG AND AHEAD WITH WIND GUSTS 20-25 KTS...BACKING OUT OF THE
W/NW WITH WIND GUSTS UP TO 30 KTS. -SHRA ALONG THE FRNT PSBLY
TRANSITIONING TO -SHSN. ANTICIPATING CONDITIONS TO FALTER TO IFR-
VLIFR DURING THE PERIOD.
THURSDAY...MODERATE CONFIDENCE.
CONDITIONS IMPROVING TO VFR. W/NW WINDS PREVAIL WITH GUSTS UP TO 25
KTS ACROSS THE SHORELINE TERMINALS.
&&
.MARINE...
MODERATE CONFIDENCE.
SURFACE PRES GRADIENT SUPPORTS PERSISTENT EASTERLY FLOW AND AN
EXPECTATION OF SEAS BUILDING TO AROUND 5 FT ACROSS OUTER COASTAL
WATERS TONIGHT. THUS HAVE CONTINUED SCA FOR HAZARDOUS SEAS. SEAS MAY
SUBSIDE BEFORE END OF ADVISORY SUN BUT NOT CONFIDENT ENOUGH TO MAKE
ANY CHANGES. THERE IS A LOW PROBABILITY OF 5 FT SEAS EDGING INTO
MASS BAY...AND ITS POSSIBLE THAT THE SCA MAY NEED TO BE EXPANDED
INTO THAT AREA LATER. OTHERWISE...MODELS GIVE A SIGNAL OF POSSIBLE
20 TO 25 KT GUSTS BEHIND THE FRONT IN THE S COASTAL WATER EARLY MON
MORNING...BUT CONFIDENCE IS LOW.
OUTLOOK...MONDAY THROUGH THURSDAY...
MONDAY INTO TUESDAY...MODERATE TO HIGH CONFIDENCE.
WAVES WILL DIMINISH AS HIGH PRES BUILDS ACROSS THE WATERS...
GRADUALLY SHIFTING EAST. DURING THIS TIME WINDS WILL GRADUALLY VEER
S/SWLY INTO TUESDAY. NOT ANTICIPATING ANY SMALL CRAFT ADV HEADLINES.
TUESDAY NIGHT THROUGH THURSDAY...MODERATE TO HIGH CONFIDENCE.
A COLD FRONT WILL SWEEP ACROSS THE WATERS WEDNESDAY. SHOWERS ARE
ANTICIPATED WITH SOME VSBY RESTRICTION. IN ADDITION...WARM MOIST AIR
OVERRUNNING THE COOLER OCEAN WILL LIKELY RESULT IN FOG ACROSS THE
WATERS ALONG THE S/SE SHORELINE. MARINERS MAY NEED TO BE CONCERNED
OF SIGNIFICANT VSBY RESTRICTIONS...BUT THINKING IS THAT PERHAPS THE
STRONG S/SWLY FLOW WILL DIMINISH THE FOG POTENTIAL. WILL CLOSELY
MONITOR. AM ANTICIPATING LOW CLOUDS.
OTHERWISE...S/SW FLOW WILL GUST 20-25 KTS ALONG AND AHEAD OF THE
FRNT...BACKING OUT OF THE W/NW WITH PASSAGE AND GUSTING UP TO GALE
FORCE /LOW CONFIDENCE/. WINDS WILL LIKELY GENERAGE SWELL RESULTING
IN WAVE HEIGHTS OF AROUND 6 FT OVER THE OUTER WATERS. SMALL CRAFT
HEADLINES ARE ANTICIPATED AND LIKELY TO CONTINUE INTO THURSDAY AS
WINDS AND WAVES BEGIN TO DIMINISH.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY UNTIL 3 AM EST SUNDAY FOR CTZ002>004.
MA...WINTER WEATHER ADVISORY UNTIL 3 AM EST SUNDAY FOR MAZ005-006-
009-011>013.
WINTER WEATHER ADVISORY UNTIL 7 AM EST SUNDAY FOR MAZ002>004-
008-010-026.
NH...WINTER WEATHER ADVISORY UNTIL 7 AM EST SUNDAY FOR NHZ011-012-
015.
RI...WINTER WEATHER ADVISORY UNTIL 3 AM EST SUNDAY FOR RIZ001.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 PM EST SUNDAY
FOR ANZ250-254-255.
&&
$$
SYNOPSIS...SIPPRELL/THOMPSON
NEAR TERM...SIPPRELL/THOMPSON
SHORT TERM...THOMPSON
LONG TERM...SIPPRELL
AVIATION...SIPPRELL/THOMPSON
MARINE...SIPPRELL/THOMPSON
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
653 PM EST SAT DEC 1 2012
.SYNOPSIS...
HIGH PRESSURE WILL PREVAIL THROUGH EARLY NEXT WEEK...WHILE A
WEAK COASTAL TROUGH PERSISTS ALONG THE SOUTHEAST COAST. A COLD
FRONT WILL THEN PASS OVER THE REGION DURING THE MIDDLE OF NEXT
WEEK FOLLOWED BY COOLER HIGH PRESSURE FOR THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
SKY COVER AND ITS POTENTIAL IMPACTS ON FOG/STRATUS DEVELOPMENT AND
LOW TEMPERATURE FORECASTS ARE THE OVERNIGHT CONCERNS. 18Z/01
GUIDANCE IS STILL OFFERING A NUMBER OF POSSIBLE OUTCOMES RANGING
FROM CLEAR TO CLOUDY. MUCH OF THE STRATOCUMULUS WAS DISSIPATING
BUT QUITE A BIT OF FLAT ALTOCUMULUS MAY LINGER. THIS SHOULD
RESULT IN MOSTLY CLEAR TO PARTLY CLOUDY SKIES...EXCEPT POSSIBLY
ALONG THE ALTAMAHA RIVER WHERE SUBTLE ISENTROPIC LIFT SHOULD KEEP
MOSTLY CLOUDY SKIES GOING THROUGH THE EVENING HOURS. THINGS BEGIN
TO CHANGE LATER THIS EVENING AND OVERNIGHT AS ANOTHER ROUND OF
WEAK ISENTROPIC LIFT REDEVELOPS ALONG THE 295K SURFACE. WRF
SIMULATED CLOUD PRODUCTS MATCH THE LATEST RAP ISENTROPIC
PROGNOSTICATIONS QUITE WELL AND SHOW LOW /MID-LEVEL CLOUDS
REFORMING ACROSS MUCH OF SOUTHEAST GEORGIA SHORT AFTER
MIDNIGHT...ARCHING BACK THROUGH THE CSRA AND SOUTHERN MIDLANDS BY
SUNRISE SUNDAY. MODIFIED THE SKY FORECAST TO MATCH THIS
IDEA...WITH MOST AREAS BECOMING PARTLY TO MOSTLY CLOUDY LATE. LOWS
WILL RANGE FROM THE MID-UPPER 40S INLAND WITH LOWER-MID 50S AT THE
COAST. HOURLY TEMPERATURES WILL BE NEARLY IMPOSSIBLE TO PIN DOWN
AS FLUCTUATIONS WILL OCCUR WHERE CLOUD LAYERS FORM. IF THIS
FORECAST HOLDS...WOULD EXPECT MOST AREAS SOUTH OF THE SAVANNAH
RIVER TO SEE TEMPERATURES HOLD STEADY OR EVEN SLOWLY RISE BETWEEN
3 AM AND SUNRISE IN RESPONSE TO THICKENING CLOUD COVER.
FOG WILL BE ANOTHER CONCERN AS DEWPOINT DEPRESSIONS DROP TO ZERO
WITHIN A DECOUPLED BOUNDARY LAYER. THERE IS A POTENTIAL FOR MORE
SIGNIFICANT FOG FORMATION EARLY SUNDAY IF CLOUDS DO NOT THICKEN UP
AS EXPECTED. WILL STICK WITH A PATCHY AREAL QUALIFIER FOR
NOW...BUT IT SHOULD BE NOTED THERE ARE SOME INDICATIONS THAT THE
FOG FORECAST MAY BE MORE SIGNIFICANT. THE EVENING SHIFT WILL
CERTAINLY MONITOR THIS AND MAKE ADJUSTMENTS AS NEEDED.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
DEEP HIGH PRESSURE WILL PERSIST OVER THE SOUTHEASTERN UNITED STATES
INTO EARLY NEXT WEEK....WHILE A COASTAL TROUGH LINGERS OFF THE SOUTH
CAROLINA AND GEORGIA COAST. A SLIGHT CHANCE OF PRECIP WILL REMAIN IN
THE FORECAST SUNDAY AFTERNOON INTO MONDAY AS THE COASTAL TROUGH
GRADUALLY SHIFTS ONSHORE. ISENTROPIC ASCENT ALONG WITH INCREASING
MOISTURE WILL ALSO PRODUCE A FAIR AMOUNT OF CLOUD COVER AS THIS
PROCESS UNFOLDS. A DRY MID/UPPER LVL ATMOSPHERE HOWEVER...WILL
LIKELY CONFINE PRECIP ACTIVITY TO COASTAL COUNTIES.
OVERALL...TEMPS WILL MODIFY EACH DAY AS MID LVL RIDGING INCREASES
AHEAD OF A TROUGH AND ASSOCIATED COLD FRONT TO OUR WEST. TEMPS WILL
LIKELY REACH 5-10 DEGREES ABOVE CLIMATOLOGY DURING THE PERIOD.
PARTLY SUNNY SKIES...SOUTH/SOUTHEAST RETURN FLOW AND 1000-850 MB
THICKNESSES FAVOR AFTERNOON HIGHS LOW/MID 70S EACH DAY. TEMPS WILL
BE WARMEST AWAY FROM THE IMMEDIATE COAST.
A DECENT AMOUNT OF RADIATIONAL COOLING IS ANTICIPATED EACH NIGHT AS
BREAKS IN CLOUD COVER OCCUR AND WINDS DECOUPLE....ESPECIALLY OVER
INLAND LOCATIONS. GIVEN A RETURN FLOW FROM THE SOUTH/SOUTHEAST...SFC
DEWPTS WILL APPROACH THE MID 50S...SETTING UP FAVORABLE CONDITIONS
FOR AT LEAST PATCHY FOG BEGINNING SUNDAY NIGHT. CHANCES OF FOG
APPEAR GREATEST MONDAY NIGHT INTO TUESDAY MORNING WHEN LOW LEVEL
MOISTURE IS ENHANCED. SHOULD TRENDS PERSIST...A DENSE FOG ADVISORY
MAY BE NEEDED OVER PORTIONS OF THE AREA.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AN UPPER TROUGH OF LOW PRESSURE ALONG WITH A SURFACE COLD FRONT LOOK
TO AFFECT THE AREA BY THE MIDDLE OF THE WEEK BUT DEEP MOISTURE AND
STRONG FORCING IS GOING TO BE LACKING AND THUS THE PROSPECTS FOR
MUCH RAINFALL APPEAR SMALL. TEMPERATURES WILL BE ABOVE NORMAL UNTIL
THURSDAY WHEN COOLER HIGH PRESSURE WEDGES IN FROM THE NORTH. SOME
MODEL DISAGREEMENT LEADS TO LOWER CONFIDENCE FOR FRIDAY BUT
PREFERRED THE SLOWER 00Z ECMWF WHICH AGREES WITH THE 12Z GFS
ENSEMBLE WHICH INDICATES THE WEDGE HOLDING IN PLACE WITH A TROUGH OF
LOW PRESSURE DEVELOPING ACROSS THE NEARBY COASTAL WATERS.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
SCATTERED TO BROKEN ALTOCUMULUS THROUGH THE COASTAL CORRIDOR ALONG
WITH A FEW STRATOCUMULUS TOWARD SAVANNAH THIS EVENING. GUIDANCE
CONTINUES TO PLACE A POTENTIAL FOR LATE NIGHT/EARLY MORNING FOG
AND/OR STRATUS CLOUDS AT THE TERMINALS. LIMITING FACTOR CONTINUES
TO BE A TRICKY OVERNIGHT CLOUD FORECAST WHICH SOUNDINGS INDICATE
LAYERS OF MOISTURE ABOVE THE BOUNDARY LAYER CONTINUING INTO SUNDAY
MORNING. OUR TAF AT KCHS INTRODUCED MVFR VSBYS AROUND DAYBREAK AND
BOTH KCHS/KSAV TAFS HAVE NOW INDICATE FEW/SCT CLOUDS BELOW 1 KFT
PER LATEST SOUNDINGS WITH LOWER FOG STABILITY INDICES INDICATED.
THERE ARE SOME CHANCES FOR IFR CONDITIONS AT THE TERMINALS BUT
CONFIDENCE ON EXTENT/TIMING IS LOW AT THIS POINT. AFTER MID
MORNING...CONDITIONS VFR AT BOTH AIRPORTS INTO SUNDAY EVENING.
EXTENDED AVIATION OUTLOOK...MVFR CEILINGS AND VISIBILITIES ARE
EXPECTED DURING LATE NIGHT/EARLY MORNING HOURS INTO EARLY NEXT WEEK.
CHANCES OF IFR VSBYS ARE POSSIBLE MONDAY NIGHT INTO TUESDAY MORNING
WITH FOG.
&&
.MARINE...
TONIGHT...A SWELL TRAIN THAT WAS GENERATED BY DEEP EASTERLY WINDS
AROUND HIGH PRESSURE OVER THE NORTH ATLANTIC IS FORECAST TO BEGIN
TO IMPACT THE WATERS TONIGHT. ALTHOUGH WINDS WILL GENERALLY REMAIN
10 KT OR LESS THROUGH SUNRISE...SEAS WILL BUILD SLIGHTLY AS
EASTERLY SWELLS INCREASE. SEAS WILL INCREASE TO 3-4 FT NEARSHORE
WATERS AND 4-5 FT OFFSHORE WATERS LATER TONIGHT. WHILE A FEW 6 FT
SEAS COULD BRUSH THE FAR EASTERN FRINGES OF THE GEORGIA OFFSHORE
WATERS...WILL HOLD OFF ON HOISTING A SMALL CRAFT ADVISORY FOR THIS
AREA GIVEN THE RELATIVELY SMALL AREA THAT WOULD BE IMPACTED.
SUNDAY THROUGH THURSDAY...HIGH PRESSURE WILL DOMINANT SC WATERS OVER
THE PERIOD...KEEPING WINDS/SEAS WELL BELOW SMALL CRAFT ADVISORY
THRESHOLDS. A COASTAL TROUGH WILL LINGER ALONG THE SOUTHERN
PERIPHERY OF HIGH PRESSURE IN GEORGIA WATERS SUNDAY/MONDAY...LEADING
TO A SLIGHT CHANCE OF SHOWERS. IN GENERAL...E/NE WINDS WILL PEAK
AROUND 10 KT WITH SEAS OF 3-5 FT...HIGHEST OVER OUTER GEORGIA
WATERS. WINDS WILL BEGIN TO VEER TO SOUTH/SOUTHEAST AS THE COASTAL
TROUGH DRIFTS ONSHORE MONDAY. A COLD FRONT WILL THEN PUSH THROUGH
THE WATERS WEDNESDAY FOLLOWED BY HIGH PRESSURE WEDGING DOWN THE
COAST FROM THE NORTH THURSDAY. A NORTHEAST WIND SURGE WILL CAUSE
DETERIORATING CONDITIONS BEHIND THE COLD FRONT THURSDAY BUT NO
HEADLINES ARE EXPECTED AT THIS TIME.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...DPB
LONG TERM...RJB
AVIATION...
MARINE...DPB/ST
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
946 AM EST FRI NOV 30 2012
.SYNOPSIS...
HIGH PRESSURE WILL PREVAIL THROUGH EARLY NEXT WEEK...WHILE A WEAK
COASTAL TROUGH PERSISTS ALONG THE SOUTHEAST COAST. A COLD FRONT
THEN EXPECTED TO CROSS THE REGION DURING THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRESSURE EXTENDS ACROSS THE REGION WITH A SUBTLE COASTAL
TROUGH NOTED JUST OFFSHORE. THE RISK FOR ISOLATED SHOWERS APPEARS
TO BE DIMINISHING SOUTH OF I-16...SO MENTIONABLE POPS HAVE BEEN
REMOVED FROM THIS AREA WITH SUPPORT FROM BOTH THE RAP AND H3R.
THE BIGGEST FORECAST CHALLENGE FOR THIS AFTERNOON IS SKY COVER.
EARLIER STRATOCUMULUS AFFECTING INLAND AREAS APPEARS TO BE
DIMINISHING SLIGHTLY PER VISIBLE SATELLITE TRENDS AS DIURNAL
MIXING DEEPENS. LATEST SHORT TERM GUIDANCE IS TRENDING WITH LESS
CLOUD COVER TODAY...BUT STILL EXPECT A HEALTHY BLEND OF
PARTLY/MOSTLY CLOUDY SKIES THROUGH LATE AFTERNOON AS A MIXTURE
OF STRATOCUMULUS AND CIRRUS TRAVERSES THE AREA. HIGHS IN THE UPPER
60S LOOK ON TRACK AWAY FROM THE BEACHES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
TONIGHT...SURFACE HIGH PRESSURE OVER THE WESTERN ATLANTIC WILL BECOME
ABSORBED BY A STRONGER HIGH PRESSURE SYSTEM MOVING INTO NORTHERN
NEW ENGLAND. IT APPEARS THAT THE WEAK COASTAL TROUGH JUST OFFSHORE
COULD AT LEAST BRIEFLY DAMPEN OUT...BEFORE REDEVELOPING LATE
TONIGHT. WHILE STRATOCUMULUS WILL PERSIST...THE COVERAGE MAY
DIMINISH SOME WITH GENERALLY PARTLY CLOUDY SKIES EXPECTED ACROSS
THE AREA. ANY ISOLATED SHOWERS THAT FORM IN THE LATE EVENING AND
OVERNIGHT HOURS SHOULD REMAIN OFFSHORE...BUT COULD NOT RULE OUT A
FEW SKIRTING THE SOUTHEAST GEORGIA COAST. RADIATIONAL COOLING
SHOULD BE BEST IN PARTS OF THE CHARLESTON TRI-COUNTY AREA WHERE
LOWS IN THE LOWER TO MID 40S ARE EXPECTED. ELSEWHERE...SLIGHTLY
BETTER COVERAGE OF CLOUD COVER SHOULD RESULT IN LOWS IN THE MID TO
UPPER 40S AWAY FROM THE WARMER BEACHES.
SATURDAY THROUGH MONDAY...DEEP HIGH PRESSURE WILL BUILD ACROSS
THE REGION THIS PERIOD BUT THERE WILL BE A TROUGH OF LOW PRESSURE
JUST OFFSHORE MOST OF THE TIME WHICH WILL LEAD TO PERIODS OF
MAINLY LIGHT SHOWERS...ESPECIALLY NEAR THE COAST.
OTHERWISE...TEMPERATURES WILL BE ABOVE NORMAL...ESPECIALLY BY
MONDAY WHEN HIGHS WILL PUSH INTO THE MID 70S AWAY FROM THE
IMMEDIATE COAST.
&&
.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
AN UPPER TROUGH OF LOW PRESSURE ALONG WITH A SURFACE COLD FRONT LOOK
TO AFFECT THE AREA BY THE MIDDLE OF THE WEEK BUT DEEP MOISTURE AND
STRONG FORCING IS GOING TO BE LACKING AND THUS THE PROSPECTS FOR
MUCH RAINFALL APPEAR SMALL. TEMPERATURES WILL BE ABOVE NORMAL UNTIL
THURSDAY WHEN COOLER HIGH PRESSURE SETS UP TO THE NORTH. BY FRIDAY
THE HIGH BEGINS TO RETREAT INTO THE ATLANTIC WITH A POSSIBLE TROUGH
OF LOW PRESSURE ACROSS THE NEARBY COASTAL WATERS.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS ARE EXPECTED TO PREVAIL AT KCHS AND KSAV THROUGH
12Z SATURDAY. A WEAK COASTAL TROUGH OFF THE GEORGIA COAST WILL
MAINTAIN A MOIST LOW-LEVEL ONSHORE FLOW ACROSS SOUTHEAST GEORGIA
THROUGH MUCH OF THE FORECAST PERIOD. THIS SHOULD RESULT IN A BROKEN
DECK OF STRATOCUMULUS AT KSAV WITH MAINLY VFR CEILINGS THROUGH
THIS AFTERNOON. AT KCHS...THE STRATOCUMULUS SHOULD BECOME
SCATTERED IN COVERAGE DURING THE DAY...BUT NO CEILINGS ARE
ANTICIPATED.
EXTENDED OUTLOOK...PERIODS OF REDUCED CEILINGS AND/OR VISIBILITIES
ARE POSSIBLE DURING THE LATE NIGHT/EARLY MORNING HOURS INTO EARLY
NEXT WEEK.
&&
.MARINE...
TODAY AND TONIGHT...HIGH PRESSURE WILL SHIFT OFF THE NORTH
CAROLINA COAST THEN BECOME ABSORBED BY A STRONGER AREA OF HIGH
PRESSURE MOVING INTO NORTHERN NEW ENGLAND LATER TONIGHT.
MEANWHILE...A WEAK COASTAL TROUGH WILL PERSIST THROUGH THIS
AFTERNOON...WEAKEN/DISSIPATE THIS EVENING THEN REDEVELOP LATER
TONIGHT. A NORTHEAST FLOW WILL PREVAIL OVER THE COASTAL
WATERS...BUT WHEN THE COASTAL TROUGH IS PRESENT THE SURFACE
PRESSURE GRADIENT WILL PINCH AND CAUSE WINDS TO SURGE UPWARDS OF
15 KT AT TIMES WEST OF THE TROUGH AXIS...OR MAINLY ACROSS PARTS OF
THE NEAR SHORE WATERS. SEAS WILL GENERALLY BE IN THE 2-3 FT
RANGE...BUT A FEW 4 FT SEAS ARE POSSIBLE AT TIMES IN THE OUTER
GEORGIA WATERS.
SATURDAY THROUGH WEDNESDAY...HIGH PRESSURE WILL CONTINUE TO BE THE
DOMINANT WEATHER FEATURE ACROSS THE AREA THROUGH EARLY NEXT WEEK
WITH A TROUGH OF LOW PRESSURE LINGERING NEARBY. A COLD FRONT WILL
THEN PUSH THROUGH WEDNESDAY. SEAS COULD BUILD UP TO 5 FT BEYOND 20
NM INTO SUNDAY GIVEN THE PERSISTENT NORTHEAST FETCH BUT NO HEADLINES
ARE EXPECTED FOR WINDS AND/OR SEAS.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
ST
AREA FORECAST DISCUSSION
NWS WICHITA KS
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 67 36 72 55 / 0 0 0 0
HUTCHINSON 62 36 72 53 / 0 0 0 0
NEWTON 63 37 72 55 / 0 0 0 0
ELDORADO 66 38 71 55 / 0 0 0 0
WINFIELD-KWLD 71 37 72 57 / 0 0 0 0
RUSSELL 59 32 72 42 / 0 0 0 0
GREAT BEND 60 33 71 44 / 0 0 0 0
SALINA 60 35 73 50 / 0 0 0 0
MCPHERSON 61 36 72 53 / 0 0 0 0
COFFEYVILLE 72 40 71 59 / 10 0 0 0
CHANUTE 70 39 70 56 / 10 0 0 0
IOLA 68 39 70 56 / 10 0 0 0
PARSONS-KPPF 71 39 71 59 / 10 0 0 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
941 PM CST SAT DEC 1 2012
.DISCUSSION...
SMALL AREAS OF DENSE FOG HAVE DEVELOPED WITHIN A WEAK TROUGH AXIS
WHERE WINDS ARE CALM AND SKIES REMAIN CLEAR. THERE HAVE BEEN ENOUGH
REPORTS OF LOW VISIBILITIES THAT IT WAS DECIDED TO ISSUE AN ADVISORY
THROUGH MID MORNING SUNDAY. HOWEVER THINK THAT AS DRY AIR STEADILY
MOVES IN FROM THE WEST AND HIGH CIRRUS THICKENS...THAT THE FOG MAY
IMPROVE AS THE NIGHT PROGRESSES. SO THE THINKING IS TO PUT THE
ADVISORY OUT NOW AND IF VISIBILITIES DO IMPROVE WE CAN CLEAR THE
ADVISORY FROM WEST TO EAST AS THE HIGH CLOUDS INCREASE.
WOLTERS
&&
.AVIATION...
BASED ON CURRENT DEWPOINT TEMPS IN THE LOWER TO MID 50S...THINK
THERE REMAINS A GOOD PROBABILITY FOR SOME FOG TO FORM TONIGHT. GIVEN
THE FORECAST LOWS ARE ABOUT 10 DEGREES COOLER THAN THE CROSS OVER
TEMP...THERE IS A REAL CONCERN FOR VSBY OF A HALF MILE OR LESS.
HOWEVER THERE APPEAR TO BE A COUPLE FACTORS WORKING AGAINST THIS
WHICH INCLUDE A LIGHT WESTERLY SFC WIND...VERY SHALLOW MOISTURE AND
SOME ENTRAINMENT OF DRY AIR AT THE TOP OF THE BOUNDARY LAYER...AND
INCREASING CIRRUS BY SUNRISE. BECAUSE OF THIS HAVE NOT GONE AS
RESTRICTIVE WITH THE VSBY BUT FEEL LIKE IFR VSBY IS POSSIBLE IF ONLY
FOR A TEMPORARY PERIOD. THE RAP AND NAM FORECAST SOUNDINGS DO NOT
MIX OUT THE BOUNDARY LAYER UNTIL ALMOST NOON...SO THE LOWER VSBY AND
POSSIBLE STRATUS MAY LINGER THROUGH MUCH OF THE MORNING.
WOLTERS
&&
.PREV DISCUSSION... /338 PM CST SAT DEC 1 2012/
TONIGHT THROUGH SUNDAY...A SURFACE LOW OVER SOUTH CENTRAL KANSAS AT
21Z WILL DRIFT TO THE EAST THROUGH THIS EVENING. LOW LEVEL MOISTURE
IS FORECAST TO REMAIN IN PLACE TO THE EAST...AND WRAPPED AROUND TO
THE NORTH OF THE SURFACE LOW. DRIER LOW LEVEL AIR REMAINED SITUATED
OVER SOUTHWEST NEBRASKA AND WHILE IT WILL EVENTUALLY ADVECT INTO THE
FORECAST AREA...IT WILL LAG A BIT BEHIND THE SURFACE LOW PASSAGE.
MEANWHILE...BOTH LOW AND HIGH CLOUDS WERE CLEARING OUT FROM WEST TO
EAST AND SHOULD CONTINUE TO DO SO THROUGH THE EVENING HOURS.
CLEARING SKIES SHOULD ALLOW FOR QUICK AND EFFECTIVE RADIATIONAL
COOLING IN LOCATIONS WHERE THE HIGHER MOISTURE CONTENT WILL STILL BE
IN PLACE. THIS SUGGESTS ANOTHER FAVORABLE SETUP FOR AREAS OF FOG
PERHAPS AS EARLY AS THIS EVENING IN NORTH CENTRAL KANSAS WHERE
AFTERNOON DEWPOINT DEPRESSIONS WERE ONLY 3 TO 5 DEGREES F.
SO INITIALLY EXPECT AN AREA OF FOG TO DEVELOP ALONG THE OVERLAPPING
AREA OF CLEAR SKIES AND REMNANT MOISTURE DURING THE EVENING WITH A
GRADUAL DECREASE OF THE FOG ON THE NORTHWEST EDGE AS THE DRIER LOW
LEVEL AIR EVENTUALLY MAKES ITS WAY EAST. AFTER MIDNIGHT IT WOULD
APPEAR MORE LIKELY THAT THE AREA OF FOG WILL INCREASE IN COVERAGE
ACROSS EASTERN KANSAS AS COOLING SHOULD OUTPACE DRY ADVECTION. THE
MAIN UNCERTAINTIES...AND REASONING FOR NOT ISSUING A DENSE FOG
ADVISORY AT THIS TIME...INVOLVE THE EXTENT TO WHICH CLOUD COVER WILL
CLEAR OUT ESPECIALLY IN FAR EASTERN KANSAS...AND JUST HOW DENSE AND
WIDESPREAD ANY FOG WILL BE. WILL NEED TO CLOSELY MONITOR THE FOG SET
UP THIS EVENING AND OVERNIGHT FOR POTENTIAL ADVISORY ISSUANCE.
ANY FOG AND CLOUDS WILL LINGER THROUGH MID MORNING ON SUNDAY WITH
SUNSHINE EXPECTED FOR THE REMAINDER OF THE DAY. ALL INDICATIONS
SUGGEST A VERY WARM DAY WITH HIGH TEMPERATURES CLIMBING INTO THE
UPPER 60S TO LOWER 70S...FLIRTING WITH RECORD VALUES. THE ONLY
UNCERTAINTY THAT WOULD INHIBIT NEAR RECORD WARMTH WOULD BE A CHANCE
OF FOG AND LOW CLOUDS HOLDING STRONG DEEPER INTO THE LATE MORNING
HOURS. WINDS SHOULD BE RATHER LIGHT THROUGH THE DAY AS WELL.
BARJENBRUCH
MONDAY THROUGH SATURDAY...MODELS STILL PROG A BROAD TROUGH TO GLIDE
ACROSS THE SOUTHERN CANADIAN PRAIRIE CAUSING PRESSURE HEIGHT FALLS
OVER THE NORTHERN AND CENTRAL PLAINS. THE MAIN INFLUENCE FROM THIS
TROUGH WILL REMAIN WELL TO THE NORTH...THUS DO NOT EXPECT ANY MAJOR
EFFECTS FROM THIS TROUGH ON THE AREA. THE ONLY REAL CHANGE TO THIS
FORECAST PACKAGE FROM PREVIOUS FORECASTS IS TO REMOVE MENTION OF
MEASURABLE PRECIPITATION ACROSS THE SOUTHEASTERN ZONES. MODELS
SOUNDINGS INDICATE A VERY SHALLOW SATURATED LAYER NEAR THE
SURFACE...AND WITH ONLY VERY MEAGER LIFT IT WILL BE VERY DIFFICULT
TO GET MUCH MORE THAN A LITTLE DRIZZLE FROM THIS MONDAY SYSTEM. A
WEAK COLD FRONT WILL ALSO PUSH THROUGH THE AREA CAUSING TEMPERATURES
TO FALL FOR THE MIDDLE PART OF THE WEEK. ALTHOUGH TEMPS WILL BE A
BIT COOLER FOR THE WEEK THAN THE VERY WARM TEMPERATURES ON THE
WEEKEND DAY TIME HIGHS WILL STILL BE ABOUT 15 DEGREES ABOVE
CLIMATOLOGICAL NORMALS. BY THE LATE HALF OF THE WEEK A MORE
AMPLIFIED TROUGH WILL DIG SOUTHWARD ACROSS THE NORTHERN PLAINS...AND
PERHAPS PROVIDE ENOUGH LIFT TO BRING A FEW SHOWERS TO NORTHEAST AND
EAST CENTRAL KANSAS THURSDAY NIGHT INTO FRIDAY. WITH COLDER AIR
COMING IN BEHIND THE PRECIP THERE WILL BE A CHANCE FOR A WINTRY MIX
OF PRECIP...NAMELY RAIN OR SNOW. WILL TRY TO PROVIDE MORE DETAILS
OF PRECIP TYPE AND AMOUNT AS THE EVENT APPROACHES...BUT SEEING AS
THOUGH IT IS 6 DAYS OUT WILL OPT TO GO WITH A CHANCE OF RAIN OR SNOW
FOR NORTH CENTRAL KANSAS AND A CHANCE FOR RAIN SHOWERS IN NORTHEAST
AND EAST CENTRAL KANSAS.
JL
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
544 PM CST SAT DEC 1 2012
...UPDATED AVIATION SECTION FOR 00Z TAFS...
.SYNOPSIS...
ISSUED AT 933 AM CST SAT DEC 1 2012
THE 01.12Z 250 HPA MAP SHOWED MOSTLY A ZONAL FLOW ACROSS THE NATION
WITH A FEW SUBTLE WAVES. A 120 KT JET WAS OBSERVED ACROSS SOUTHWESTERN
OREGON. ANOTHER 100 KT JET WAS OBSERVED ACROSS NORTH DAKOTA. AT 500
HPA, A DEEP CYCLONE WAS LOCATED WEST OF BRITISH COLUMBIA WITH AN ASSOCIATED
TROF MOVING ACROSS THE PACIFIC NORTHWEST. ANOTHER TROF WAS MOVING OUT
ACROSS THE PLAINS. MID LEVEL TEMPERATURES WERE MAINLY IN THE NEGATIVE
TEENS/20S WITH -30 DEG C AND BELOW CONFINED TO SE CANADA. AT 700 HPA,
TEMPERATURES INCREASED A FEW DEGREES CENTIGRADE AT KDDC AHEAD OF A WAVE.
AT 850 HPA, A WARM PLUME OF AROUND 18 DEG C PREVAILED ACROSS THE SOUTHERN
AND CENTRAL PLAINS. THE ATMOSPHERE WAS FAIRLY DRY AT THIS CONSTANT PRESSURE
LEVEL AS WELL. THE COLDER AIR OF -15 DEG C AND BELOW WAS CONFINED TO
SE CANADA. AT THE SFC, A STATIONARY BOUNDARY WAS DRAPED ACROSS KANSAS.
RESPECTABLE DEWPOINTS...FOR THE BEGINNING OF DECEMBER...WITH VALUES
RUNNING IN THE 50S DEG F WERE SOUTH OF SAID BOUNDARY ACROSS THE SC/SE
PORTION OF THE STATE.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 136 PM CST SAT DEC 1 2012
TONIGHT:
FAIRLY TRANQUIL CONDITIONS ARE EXPECTED TONIGHT. HIGH LEVEL CLOUDS WILL
MOVE OFF TO THE EAST THIS EVENING AND SKIES SHOULD BE CLEAR THROUGH
THE OVERNIGHT HOURS. BUFKIT FORECAST SOUNDINGS, MOS GUIDANCE, THE VERY
END OF THE HRRR RUN, AND THE NSSL WRF MODEL HIGHLIGHTS A CONCERN FOR PATCHY
FOG TOMORROW MORNING. DEWPOINTS WILL BE LOWER THAN COMPARED TO THIS
MORNING. DRIER AIR WILL ADVECT IN FROM THE NW. STILL, CONSIDERING EVERYTHING
ABOVE, I HAVE INSERTED PATCHY FOG ALONG AND EAST OF HIGHWAY 283. THIS
MIGHT BE ON THE LIBERAL SIDE AND MAY HAVE TO BE TRIMMED FARTHER EAST.
OTHERWISE, LOWS WILL BE MAINLY IN THE 30S DEG F.
TOMORROW:
OTHER THAN THE AFOREMENTIONED FOG AND SOME AFTERNOON CIRRUS, TOMORROW
WILL BE CLEAR WITH FULL INSOLATION. DID NOT CHANGE MAXIMUM TEMPERATURES
FOR TOMORROW AS THE GRID LOOKS STILL ON TRACK WITH 12Z DATA. IT WILL
BE VERY WARM TOMORROW WITH HIGHS AROUND 70 DEG F. THE AVERAGE HIGH FOR
THIS TIME OF YEAR IS AROUND 48 DEG F. THESE WARM TEMPERATURES ARE A
RESULT OF THE DEEPENING OF THE LEE SURFACE TROUGH ACROSS EASTERN COLORADO
AND RESULTANT CONTINUED WARM AIR ADVECTION. 850 HPA TEMPERATURES AROUND
15 DEG C AND ADIABATIC MIXING STILL SUPPORT THE WARM TEMPS AT THE SURFACE.
LASTLY, RH`S LOOK MARGINAL FOR TOMORROW SO NOT EXPECTING ANY FIRE WX
CONCERNS ATTM. IT WILL BE BREEZY TOMORROW, BUT NOTHING OUT OF THE ORDINARY
IN TERMS OF WESTERN KANSAS WIND STANDARDS (GENERALLY 12-21 KT).
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 239 PM CST SAT DEC 1 2012
FOR MONDAY, A DRY AND PROGRESSIVE UPPER LEVEL SHORTWAVE TROUGH WILL
MOVE ACROSS THE PLAINS HELPING TO PUSH A COLD FRONT ACROSS WESTERN
KANSAS IN THE MORNING. WINDS WILL BE GUSTY TO 15 TO 25 MPH WITH THE
COLD FRONT. HIGHS WILL STILL BE MILD IN THE 60S. FOR TUESDAY INTO
THURSDAY, DRY WEST TO NORTHWESTERLY UPPER LEVEL FLOW CONTINUES
ACROSS THE CENTRAL CONUS, WITH THE NEXT UPPER LEVEL SHORTWAVE TROUGH
DIGGING INTO THE INTERMOUNTAIN WEST ON THURSDAY FROM THE PACIFIC
NORTHWEST. HIGHS LOOK MILD AND AROUND 60 WITH SOUTHERLY FLOW AHEAD
OF A LEE SURFACE TROUGH. THIS NEXT SHORTWAVE WILL MOVE ACROSS THE
PLAINS ON FRIDAY WITH INCREASING MID AND UPPER LEVEL MOISTURE AND A
CANADIAN COLD FRONT. A FEW LIGHT RAIN OR LIGHT SNOW SHOWERS ARE
POSSIBLE, HOWEVER THE LOWER LEVELS LOOK FAIRLY DRY AND MAY BE MOSTLY
VIRGA. WILL LEAVE A SMALL POP GOING IN CASE. BOTH THE GFS AND ECMWF
SHOW VERY MINOR AMOUNTS IF ANY WITH HIGHS IN THE 40S. BY SATURDAY
THE MODELS DIVERGE WITH THE GFS SHOWING A WARM SOUTHWESTERLY UPPER
LEVEL FLOW, WHILE THE ECMWF IS SHOWING A COOLER NORTHWESTERLY FLOW
ALOFT. CONSENSUS HAS HIGHS IN THE 40S WHICH LOOKS REASONABLE.
OVERNIGHT LOWS THROUGH THE PERIOD LOOK TO BE IN 30S COOLING INTO THE
20S BY SATURDAY MORNING.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 543 PM CST SAT DEC 1 2012
A VERY WEAK PRESSURE GRADIENT WILL EXIST TONIGHT RESULTING IN VERY
LIGHT IF NOT CALM WINDS THROUGH THE OVERNIGHT HOURS. FOG
DEVELOPMENT IS EXPECTED TO BE CONFINED TO CENTRAL AND EASTERN KANSAS
AS YESTERDAY`S WEAK FRONTAL PASSAGE PUSHED GULF OF MEXICO MOISTURE
AWAY FROM WESTERN KANSAS. THERE IS SOME RESIDUAL LOW LEVEL MOISTURE
LEFT BEHIND, HOWEVER MOST LIKELY NOT ENOUGH TO LOWER VISIBILITY BY
DAYBREAK SO WILL KEEP THE TAFS VFR THROUGHOUT AT DDC, GCK, AND HYS.
SOUTH TO SOUTHEAST WINDS WILL INCREASE ABOUT 3 OR 4 HOURS AFTER
SUNRISE SUNDAY MORNING TO 12 TO 15 KNOTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 34 71 38 65 / 0 0 0 0
GCK 33 71 36 64 / 0 0 0 0
EHA 39 72 38 64 / 0 0 0 0
LBL 36 73 35 65 / 0 0 0 0
HYS 34 71 36 62 / 0 0 0 0
P28 36 73 47 68 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM...KRUSE
AVIATION...UMSCHEID
AREA FORECAST DISCUSSION
NWS WICHITA KS
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 34 72 53 66 / 0 0 0 0
NEWTON 35 72 55 67 / 0 0 0 0
ELDORADO 36 71 55 69 / 0 0 0 0
WINFIELD-KWLD 38 72 57 71 / 0 0 0 0
RUSSELL 34 72 42 64 / 0 0 0 0
GREAT BEND 33 71 44 65 / 0 0 0 0
SALINA 34 73 50 66 / 0 0 0 0
MCPHERSON 34 72 53 66 / 0 0 0 0
COFFEYVILLE 49 71 59 71 / 0 0 0 20
CHANUTE 43 70 56 70 / 0 0 0 10
IOLA 40 70 56 70 / 0 0 0 10
PARSONS-KPPF 47 71 59 71 / 0 0 0 20
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
516 PM CST SAT DEC 1 2012
.DISCUSSION...
SEE PREV DISCUSSION.
&&
.AVIATION...
BASED ON CURRENT DEWPOINT TEMPS IN THE LOWER TO MID 50S...THINK
THERE REMAINS A GOOD PROBABILITY FOR SOME FOG TO FORM TONIGHT. GIVEN
THE FORECAST LOWS ARE ABOUT 10 DEGREES COOLER THAN THE CROSS OVER
TEMP...THERE IS A REAL CONCERN FOR VSBY OF A HALF MILE OR LESS.
HOWEVER THERE APPEAR TO BE A COUPLE FACTORS WORKING AGAINST THIS
WHICH INCLUDE A LIGHT WESTERLY SFC WIND...VERY SHALLOW MOISTURE AND
SOME ENTRAINMENT OF DRY AIR AT THE TOP OF THE BOUNDARY LAYER...AND
INCREASING CIRRUS BY SUNRISE. BECAUSE OF THIS HAVE NOT GONE AS
RESTRICTIVE WITH THE VSBY BUT FEEL LIKE IFR VSBY IS POSSIBLE IF ONLY
FOR A TEMPORARY PERIOD. THE RAP AND NAM FORECAST SOUNDINGS DO NOT
MIX OUT THE BOUNDARY LAYER UNTIL ALMOST NOON...SO THE LOWER VSBY AND
POSSIBLE STRATUS MAY LINGER THROUGH MUCH OF THE MORNING.
WOLTERS
&&
.PREV DISCUSSION... /338 PM CST SAT DEC 1 2012/
TONIGHT THROUGH SUNDAY...A SURFACE LOW OVER SOUTH CENTRAL KANSAS AT
21Z WILL DRIFT TO THE EAST THROUGH THIS EVENING. LOW LEVEL MOISTURE
IS FORECAST TO REMAIN IN PLACE TO THE EAST...AND WRAPPED AROUND TO
THE NORTH OF THE SURFACE LOW. DRIER LOW LEVEL AIR REMAINED SITUATED
OVER SOUTHWEST NEBRASKA AND WHILE IT WILL EVENTUALLY ADVECT INTO THE
FORECAST AREA...IT WILL LAG A BIT BEHIND THE SURFACE LOW PASSAGE.
MEANWHILE...BOTH LOW AND HIGH CLOUDS WERE CLEARING OUT FROM WEST TO
EAST AND SHOULD CONTINUE TO DO SO THROUGH THE EVENING HOURS.
CLEARING SKIES SHOULD ALLOW FOR QUICK AND EFFECTIVE RADIATIONAL
COOLING IN LOCATIONS WHERE THE HIGHER MOISTURE CONTENT WILL STILL BE
IN PLACE. THIS SUGGESTS ANOTHER FAVORABLE SETUP FOR AREAS OF FOG
PERHAPS AS EARLY AS THIS EVENING IN NORTH CENTRAL KANSAS WHERE
AFTERNOON DEWPOINT DEPRESSIONS WERE ONLY 3 TO 5 DEGREES F.
SO INITIALLY EXPECT AN AREA OF FOG TO DEVELOP ALONG THE OVERLAPPING
AREA OF CLEAR SKIES AND REMNANT MOISTURE DURING THE EVENING WITH A
GRADUAL DECREASE OF THE FOG ON THE NORTHWEST EDGE AS THE DRIER LOW
LEVEL AIR EVENTUALLY MAKES ITS WAY EAST. AFTER MIDNIGHT IT WOULD
APPEAR MORE LIKELY THAT THE AREA OF FOG WILL INCREASE IN COVERAGE
ACROSS EASTERN KANSAS AS COOLING SHOULD OUTPACE DRY ADVECTION. THE
MAIN UNCERTAINTIES...AND REASONING FOR NOT ISSUING A DENSE FOG
ADVISORY AT THIS TIME...INVOLVE THE EXTENT TO WHICH CLOUD COVER WILL
CLEAR OUT ESPECIALLY IN FAR EASTERN KANSAS...AND JUST HOW DENSE AND
WIDESPREAD ANY FOG WILL BE. WILL NEED TO CLOSELY MONITOR THE FOG SET
UP THIS EVENING AND OVERNIGHT FOR POTENTIAL ADVISORY ISSUANCE.
ANY FOG AND CLOUDS WILL LINGER THROUGH MID MORNING ON SUNDAY WITH
SUNSHINE EXPECTED FOR THE REMAINDER OF THE DAY. ALL INDICATIONS
SUGGEST A VERY WARM DAY WITH HIGH TEMPERATURES CLIMBING INTO THE
UPPER 60S TO LOWER 70S...FLIRTING WITH RECORD VALUES. THE ONLY
UNCERTAINTY THAT WOULD INHIBIT NEAR RECORD WARMTH WOULD BE A CHANCE
OF FOG AND LOW CLOUDS HOLDING STRONG DEEPER INTO THE LATE MORNING
HOURS. WINDS SHOULD BE RATHER LIGHT THROUGH THE DAY AS WELL.
BARJENBRUCH
MONDAY THROUGH SATURDAY...MODELS STILL PROG A BROAD TROUGH TO GLIDE
ACROSS THE SOUTHERN CANADIAN PRAIRIE CAUSING PRESSURE HEIGHT FALLS
OVER THE NORTHERN AND CENTRAL PLAINS. THE MAIN INFLUENCE FROM THIS
TROUGH WILL REMAIN WELL TO THE NORTH...THUS DO NOT EXPECT ANY MAJOR
EFFECTS FROM THIS TROUGH ON THE AREA. THE ONLY REAL CHANGE TO THIS
FORECAST PACKAGE FROM PREVIOUS FORECASTS IS TO REMOVE MENTION OF
MEASURABLE PRECIPITATION ACROSS THE SOUTHEASTERN ZONES. MODELS
SOUNDINGS INDICATE A VERY SHALLOW SATURATED LAYER NEAR THE
SURFACE...AND WITH ONLY VERY MEAGER LIFT IT WILL BE VERY DIFFICULT
TO GET MUCH MORE THAN A LITTLE DRIZZLE FROM THIS MONDAY SYSTEM. A
WEAK COLD FRONT WILL ALSO PUSH THROUGH THE AREA CAUSING TEMPERATURES
TO FALL FOR THE MIDDLE PART OF THE WEEK. ALTHOUGH TEMPS WILL BE A
BIT COOLER FOR THE WEEK THAN THE VERY WARM TEMPERATURES ON THE
WEEKEND DAY TIME HIGHS WILL STILL BE ABOUT 15 DEGREES ABOVE
CLIMATOLOGICAL NORMALS. BY THE LATE HALF OF THE WEEK A MORE
AMPLIFIED TROUGH WILL DIG SOUTHWARD ACROSS THE NORTHERN PLAINS...AND
PERHAPS PROVIDE ENOUGH LIFT TO BRING A FEW SHOWERS TO NORTHEAST AND
EAST CENTRAL KANSAS THURSDAY NIGHT INTO FRIDAY. WITH COLDER AIR
COMING IN BEHIND THE PRECIP THERE WILL BE A CHANCE FOR A WINTRY MIX
OF PRECIP...NAMELY RAIN OR SNOW. WILL TRY TO PROVIDE MORE DETAILS
OF PRECIP TYPE AND AMOUNT AS THE EVENT APPROACHES...BUT SEEING AS
THOUGH IT IS 6 DAYS OUT WILL OPT TO GO WITH A CHANCE OF RAIN OR SNOW
FOR NORTH CENTRAL KANSAS AND A CHANCE FOR RAIN SHOWERS IN NORTHEAST
AND EAST CENTRAL KANSAS.
JL
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
858 AM MST FRI NOV 30 2012
.UPDATE...
ISSUED AT 851 AM MST FRI NOV 30 2012
JUST COMPLETED AN UPDATE. MAIN CHANGE PER SATELLITE AND NEWEST
MODEL DATA WAS TO INCREASE CLOUD COVER...ESPECIALLY FOR OUR NORTHERN
LOCATIONS...FOR TODAY. THIS INCREASE IS DUE TO A LEFT FRONT QUADRANT
OF A JET MOVING THROUGH. ALSO INCREASED SKY COVER FOR LATER TONIGHT
INTO TOMORROW. BECAUSE OF THE COLD START TODAY...MORE CLOUD
COVER...WHAT LOOKS TO BE A LATER CHANGE TO SOUTHERLY WINDS...AND
NEWEST MODEL DATA WHICH IS A LITTLE COOLER...CHOSE TO COOL OFF THE
MAXES TODAY A FEW DEGREES. ADJUSTED WINDS AS WELL FOR TODAY BASED
ON LATEST RUC AND OBSERVATIONAL TRENDS.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY NIGHT)
ISSUED AT 303 AM MST FRI NOV 30 2012
WARM AND DRY CONDITIONS CONTINUE.
AN UPPER LEVEL SHORT WAVE RIDGE WILL MOVE ACROSS THE REGION TODAY WITH
A WEAK SHORT WAVE TROUGH MOVING THROUGH THE UPPER FLOW ON
SATURDAY. A SURFACE TROUGH WILL MOVE ACROSS THE CENTRAL HIGH
PLAINS ON SATURDAY IN RESPONSE TO THE UPPER SHORT WAVE MOVING
ACROSS THE REGION.
ANOTHER COUPLE OF SHORT WAVE TROUGHS WILL MOVE ACROSS THE REGION BETWEEN
LATE SUNDAY AND EARLY MONDAY MORNING AHEAD OF THE NEXT LARGER
TROUGH DUE THROUGH THE AREA ON MONDAY. THE PRE-FRONTAL SURFACE
TROUGH WILL DEEPEN OVER EASTERN COLORADO ON SUNDAY AND SUNDAY
NIGHT AHEAD OF THE COLD FRONT EXPECTED ON MONDAY.
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 303 AM MST FRI NOV 30 2012
A COLD FRONT WILL MOVE ACROSS THE AREA EARLY MONDAY FOLLOWED BY AN
UPPER LEVEL SHORT WAVE TROUGH. MODELS CONTINUE TO PUSH THE BETTER
LIFT AND MOISTURE NORTH...SO THE AREA WILL ONLY SEE A FEW CLOUDS AT
BEST. THE NEXT COLD FRONT MOVES THROUGH THURSDAY FOLLOWED BY AN
UPPER LEVEL TROUGH THURSDAY NIGHT. AS WITH THE PREVIOUS
TROUGH...THE MAJORITY OF THE LIFT AND MOISTURE WILL BE NORTH OF THE
AREA. HOWEVER THERE WILL BE SOME LIFT AND MOISTURE OVER THE AREA TO
WORK WITH AS THE UPPER LEVEL TROUGH MOVES THROUGH. CHANCES FOR
PRECIP DO NOT LOOK TOO GOOD...BUT ENOUGH TO WARRANT A MENTION OF
PRECIP. DESPITE THE PASSAGE OF THE COLD FRONTS...TEMPERATURES FOR
THE PERIOD WILL BE SIMILAR TO THE LAST FEW DAYS. MODELS CONTINUE TO
INDICATE A THREAT FOR HAZARDOUS FIRE WEATHER CONDITIONS MONDAY
AFTERNOON BEHIND THE FIRST COLD FRONT...AS RELATIVE HUMIDITIES FALL
TO LESS THAN 20 PERCENT AND WINDS GUST TO 30 MPH.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 559 AM MST FRI NOV 30 2012
VFR CONDITIONS WILL CONTINUE WITH PERIODIC INCREASES AND DECREASES
IN HIGH CLOUDS OVER THE NEXT 24 HOURS. LIGHT AND VARIABLE WINDS
AFTER 12Z WILL BECOME SOUTH AND POSSIBLY GUSTY BY 18Z AND THEN
TURN TO THE SOUTHWEST AND BECOME LIGHT AGAIN AFTER 00Z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...BULLER
SHORT TERM...LOCKHART
LONG TERM...JTL
AVIATION...LOCKHART
AREA FORECAST DISCUSSION
NWS CARIBOU ME
954 PM EST SAT DEC 1 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 SUNDAY/...
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.
PREVIOUS DISCUSSION:
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 /SUNDAY NIGHT 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 SATURDAY/...
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 /03Z 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 FROM 3 AM TO 1 PM EST SUNDAY FOR
MEZ001-002.
WINTER WEATHER ADVISORY UNTIL 9 AM EST SUNDAY FOR MEZ003>006-
010-011-031-032.
WINTER WEATHER ADVISORY UNTIL 6 AM EST SUNDAY FOR MEZ015>017-
029-030.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST MONDAY FOR ANZ050>052.
&&
$$
NEAR TERM...HEWITT
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
939 PM EST SAT DEC 1 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 SUNDAY/...
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.
PREVIOUS DISCUSSION FOLLOWS...
&&
.SHORT TERM /SUNDAY NIGHT 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 /02Z SUNDAY THROUGH THURSDAY/...
WILL UPDATE TERMINALS BY 03Z FOR A DEGRADATION IN IFR TO LIFR FOG
FOR EARLY SUNDARY MORNING...ESPECIALLY FOR THE METRO TERMINALS.
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...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SMZ
NEAR TERM...SMZ
SHORT TERM...NWL
LONG TERM...NWL
AVIATION...SMZ
MARINE...SMZ
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
558 PM EST FRI NOV 30 2012
.SYNOPSIS...
AN EASTBOUND UPPER DISTURBANCE WILL MAINTAIN MOSTLY CLOUDY SKIES
ACROSS THE UPPER OHIO VALLEY TONIGHT WHILE SOUTHWESTERLY WIND
PROVIDES MILD TEMPERATURES WHICH WILL PERSIST FOR THE WEEKEND.
PERIODIC SHOWER CHANCES CAN BE EXPECTED FOR THE FIRST HALF OF THE
NEW WEEK WITH THE ADVANCE AND PASSAGE OF A FRONTAL SYSTEM.
&&
.NEAR TERM /THROUGH SATURDAY/...
PER BLEND OF RECENT SURFACE AND SATELLITE DATA COUPLED WITH RECENT
RAP AND NAM MODEL OUTPUT...THICK ALTOCUMULUS AND CIRROPSTRATUS
CLOUDS WILL CONTINUE TO FLOW OVER THE REGION TONIGHT AS SHORTWAVE
TROUGH PROGRESSES EASTWARD. RECENT RADAR DATA ALSO INDICATES SOME
LIGHT SHOWERS...BUT THE DRY LOW LEVEL OF THE ATMOSPHERE WILL
INHIBIT ANY MEASURABLE PRECIP...HENCE...MENTION OF SPRINKLES FOR
THE EVE SHOULD SUFFICE.
OVERNIGHT LOW WERE FORECAST ABOUT 5 DEGREES ABOVE THE AVERAGES
USING GFS...NAM MOS AND RAP MODEL OUTPUT.
BETTER INSOLATION IN THE WAKE OF TONIGHTS UPPER DISTURBANCE...IN
ADDITION TO WARM ADVCTN REGIME OVR THE AREA...WILL SUPPORT
SATURDAY HIGHS APPROXIMATELY 10 TO 15 ABOVE NORMAL.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
WARM TO NEUTRAL ADVCTN IN ADVN OF...AND FOLLOWING PASSAGE OF A SHORTWAVE
IN GENLY ZONAL FLOW WILL MAINTAIN CONTINUED WARMTH ACROSS THE UPPER
OHIO VALLEY FOR THE SHORT TERM PERIOD. GFS AND NAM MOS SUGGEST TEMPERATURES
MAY BE 15 TO 20 DEGREES WARMER THAN NORMAL. HOWEVER...THE RELIEF FROM
COLD WILL BE MARRED BY INCREASING SHOWER CHANCES ON SUNDAY AS MOISTURE
AND ASCENT PROFILES ARE ALSO BE IMPROVED BY THE APPROACHING SYSTEM.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MODELS WERE IN GENERAL AGREEMENT ON THE OVERALL PATTERN DURING THE
LONG TERM PERIOD...BUT VARY ON TIMING. PREFERRED THE NAEFS SOLUTION
WHICH WAS SLOWER THAN THE GFS BUT SLIGHTLY FASTER THAN THE ECMWF.
A COLD FRONT WILL MOVE ACROSS THE REGION LATE TUESDAY INTO TUESDAY
NIGHT BRINGING A FEW SHOWERS. COLDER AIR MOVING IN BEHIND THE FRONT
ON WEDNESDAY...COMBINED WITH AN UPPER LEVEL TROF MOVING ACROSS THE
GREAT LAKES...COULD BRING A FEW SNOW SHOWERS TO THE FAR NORTHERN
COUNTIES DURING THE DAY...HOWEVER HIGH PRESSURE SHOULD QUICKLY BUILD
IN ENDING ANY PRECIP.
EXPECT TEMPS WEDNESDAY TO SLOWLY FALL OFF DURING THE LATE MORNING
AND AFTERNOON AS WELL WITH THE CAA. TEMPS SHOULD INCREASE TO ABOVE
NORMAL LEVELS AGAIN BY LATE IN THE WEEK.
ANOTHER COLD FRONT APPROACHES FROM THE WEST FRIDAY AFTERNOON.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
NO RESTRICTIONS ARE EXPECTED DURING THE TAF PERIOD ALTHOUGH MID
AND HIGH CLOUDS WILL STREAM ACRS UPR OH TERMINALS TONIGHT WITH
PASSAGE OF A CROSSING SHORTWAVE. SUSTAINED SFC WIND IS EXPECTED TO
RMN LESS THAN 10 KTS FOR THE PD.
.OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/...
RESTRICTIONS WILL BE POSSIBLE SUNDAY AFTERNOON AND NIGHT...DUE TO
SHOWER FORMATION ALONG A WEAK EASTBOUND FRONT. A BETTER RESTRICTION
CHANCE WILL ACCOMPANY A STRONG COLD FRONT PASSAGE ON TUESDAY NIGHT...AND
WILL LIKELY PERSIST WITH COLD POOL CLOUDS AND SCATTERED SNOW SHOWERS
WEDNESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
15
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
315 PM EST FRI NOV 30 2012
.SYNOPSIS...
EASTBOUND LOW PRESSURE ALOFT WILL PROMOTE MOSTLY CLOUDY SKIES
ACROSS THE UPPER OHIO VALLEY TONIGHT. SOUTHWEST WINDS WILL PROVIDE
MILD TEMPERATURES THIS WEEKEND. A SECOND EASTBOUND LOW PRESSURE
SYSTEM WILL BRING SHOWERS SUNDAY AFTERNOON. THEN A STRONGER
EASTBOUND LOW PRESSURE SYSTEM WILL BRING SHOWERS TUESDAY NIGHT
FOLLOWED BY A COOL DOWN WEDNESDAY.
&&
.NEAR TERM /THROUGH SATURDAY/...
PER BLEND OF RECENT SURFACE AND SATELLITE DATA COUPLED WITH RECENT
RAP AND NAM MODEL OUTPUT...CONTINUE TO EXPECT BANDS OF THICK ALTOCUMULUS
AND CIRRUS CLOUDS TO PASS EASTWARD ACROSS THE UPPER OHIO VALLEY
THROUGH TONIGHT. THESE CLOUDS ARE ASSOCIATED WITH AN EASTBOUND
TROUGH ALOFT. RECENT RADAR DATA SHOWS AN EASTBOUND BAND OF PRECIPITATION-
SIZED PARTICLES...VIRGA...ACROSS OHIO. SO HAVE MENTIONED POSSIBLE
SPRINKLES AS LOW LEVELS SHOULD REMAIN RATHER DRY.
PER RECENT GFS AND NAM MOS AND RAP MODEL OUTPUT...FORECASTED LOW
TEMPERATURES TONIGHT TO BE WARMER THAN NORMAL...BY ABOUT 5
DEGREES. EXPECT DECREASED CLOUDS SATURDAY SO HIGHS SATURDAY
AFTERNOON CAN BE 10 TO 15 DEGREES WARMER THAN NORMAL.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
POST HIGH PRESSURE WILL PROMOTE MILD TEMPERATURES TO CONTINUE
ACROSS THE UPPER OHIO VALLEY THIS PERIOD. GFS AND NAM MOS SUGGEST
TEMPERATURES SUNDAY INTO MONDAY CAN BE 15 TO 20 DEGREES WARMER
THAN NORMAL.
BLEND OF RECENT SREF MODEL OUTPUT CONTINUE TO SHOW AN OCCLUDING
LOW PRESSURE SYSTEM MOVING EASTWARD THROUGH THE GREAT LAKES
SUNDAY...THAT WILL LIKELY BRING SHOWERS TO THE UPPER OHIO VALLEY
SUNDAY AFTERNOON AND EVENING. PRE-SHOWER WINDS SUNDAY AFTERNOON
CAN PRODUCE GUSTS TO 30 MPH.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MODELS WERE IN GENERAL AGREEMENT ON THE OVERALL PATTERN DURING THE
LONG TERM PERIOD...BUT VARY ON TIMING. PREFERRED THE NAEFS SOLUTION
WHICH WAS SLOWER THAN THE GFS BUT SLIGHTLY FASTER THAN THE ECMWF.
A COLD FRONT WILL MOVE ACROSS THE REGION LATE TUESDAY INTO TUESDAY
NIGHT BRINGING A FEW SHOWERS. COLDER AIR MOVING IN BEHIND THE FRONT
ON WEDNESDAY...COMBINED WITH AN UPPER LEVEL TROF MOVING ACROSS THE
GREAT LAKES...COULD BRING A FEW SNOW SHOWERS TO THE FAR NORTHERN
COUNTIES DURING THE DAY...HOWEVER HIGH PRESSURE SHOULD QUICKLY BUILD
IN ENDING ANY PRECIP.
EXPECT TEMPS WEDNESDAY TO SLOWLY FALL OFF DURING THE LATE MORNING
AND AFTERNOON AS WELL WITH THE CAA. TEMPS SHOULD INCREASE TO ABOVE
NORMAL LEVELS AGAIN BY LATE IN THE WEEK.
ANOTHER COLD FRONT APPROACHES FROM THE WEST FRIDAY AFTERNOON.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
NO RESTRICTIONS ARE EXPECTED DURING THE TAF PERIOD. HIGH CLOUDS WILL
LIKELY BE PERSISTENT THROUGH THE NEXT 24 HOURS...WITH THE BEST
CHANCE FOR MID LEVEL CLOUDS DURING THE EVENING INTO THE OVERNIGHT
HOURS. WHILE WINDS MAY OCCASIONALLY GUST TO 15 KTS LATE THIS
AFTERNOON AND TOMORROW AFTERNOON...WINDS ARE GENERALLY EXPECTED TO
BE OUT OF THE SOUTH AT LESS THAN 10 KTS.
.OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/...
RESTRICTIONS WILL BE POSSIBLE SUNDAY AFTERNOON AND NIGHT...DUE TO
SHOWERS DUE TO A WEAK EASTBOUND FRONT. A STRONG COLD FRONTAL
PASSAGE TUESDAY NIGHT WILL LIKELY BRING RESTRICTIONS DUE TO RAIN
SHOWERS TUESDAY NIGHT AND COLD POOL CLOUDS AND SCATTERED SNOW
SHOWERS WEDNESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GAYLORD MI
1145 PM EST THU NOV 29 2012
.SYNOPSIS...
ISSUED AT 406 PM EST THU NOV 29 2012
THE SEASONABLY CHILLY AIR WILL CONTINUE TO HANG ACROSS THE REGION
THROUGH FRIDAY...BRINGING A BIT MORE LIGHT SNOW SHOWERS OR FLURRIES
AT TIMES. PERHAPS EVEN SOME FREEZING DRIZZLE LATER TONIGHT INTO
FRIDAY MORNING. MILDER TEMPERATURES AND RAIN CHANCES...WILL MAKE A
RETURN TO NORTHERN MICHIGAN THIS WEEKEND...AND INTO EARLY NEXT
WEEK...AS A PAIR OF SYSTEMS MOVE OVER THE NORTHERN PLAINS AND PASS
NORTHWEST OF THE STATE.
&&
.UPDATE...
ISSUED AT 1102 PM EST THU NOV 29 2012
EARLIER FCST UPDATE ACTUALLY WORKING OUT RATHER WELL (THAT DOESN`T
ALWAYS HAPPEN HERE!)...AND PER LATEST RADAR/RAP TRENDS...HAVE
DECIDED TO HOIST A WINTER WEATHER ADVISORY BASICALLY FROM M-72 ON
NORTH THROUGH MID MORNING. ALREADY SEEING A NICE COATING OF ICE
HERE AT THE OFFICE AND ACROSS THE HIGHER TERRAIN PER SPOTTER
REPORTS. PER RAP GUIDANCE (WHICH HAD THE BEST HANDLE OF BLOSSOMING
OF PRECIP EARLIER)...BEST LOW LEVEL WARM ADVECTION ASCENT IN THE
925-875MB LAYER WILL OCCUR BASICALLY NORTH OF M-72 OVERNIGHT. THAT
DOESN`T PRECLUDE SOME PATCHY FREEZING DRIZZLE TO THE SOUTH...
ESPECIALLY GIVEN STALLING ARCTIC FRONTAL BOUNDARY DOWN THAT WAY
AND BETTER POOLED MOISTURE...BUT CURRENT ADVISORY AREA IS MY BEST
GUESS WHERE THINGS MAY GET QUITE SLICK BY MORNING. CAN FORESEE A
BIT OF A MIX WITH SOME SNOW AT TIMES LATER TONIGHT AS WELL AS MID
LEVEL MOISTURE DEPTH DEEPENS...BUT THAT WOULD ONLY HELP MATTERS.
OUTSIDE OF THE ADVISORY...NO MAJOR CHANGES NEEDED.
UPDATE ISSUED AT 933 PM EST THU NOV 29 2012
EVENT STARTING TO GET UNDERWAY OVER THE PAST 2 HOURS...WITH A
NARROW BUT WELL-DEFINED AXIS OF LIGHT RADAR RETURNS CENTERED JUST
SOUTH OF THE M-32 CORRIDOR. THIS IS ALONG A SHALLOW (925-875MB)
AXIS OF FRONTOGENESIS AS LOW LEVEL ARCTIC AIR CONTINUES TO BLEED
BENEATH WARMER REGIME ALOFT. PER OBS OUT THE WINDOW...WE HAVE SEEN
BOTH SOME LIGHT SNOW AND FREEZING DRIZZLE...CONSISTENT WITH 00Z
APX RAOB SHOWING SATURATION NEARING -10C...AND A DEEPENING OF THE
COLD WITHIN THE SATURATED LAYER (LEADING TO MORE OF A FROZEN
DRIZZLE SCENARIO EARLIER). SUSPECT THIS WILL BE THE CASE
OVERNIGHT...AND PER SHORT TERM GUIDANCE TRENDS...HAVE REWORKED
POPS/WEATHER TO FOCUS INITIALLY ON THE HIGHER TERRAIN.
HOWEVER...SUSPECT PRECIP WILL BECOME MUCH MORE WIDESPREAD AFTER
06Z AS A RATHER ROBUST UPPER WAVE BEGINS ITS APPROACH...AND LOW
LEVEL WARM ADVECTION ASCENT CRANKS UP (ALBEIT STILL FAIRLY WEAK).
ALSO SEEING A GRADUAL TOP-DOWN SATURATION ONGOING PER HIGHER RADAR
SCANS...AND GIVEN THIS AND STRONG QPF SIGNAL FROM ALL AVAILABLE
GUIDANCE...HAVE TO BELIEVE WE WILL END UP SEEING A PERIOD OF
LIGHTER SNOWS ACROSS MUCH OF NORTHERN LOWER LATER TONIGHT AS
SEEDER-FEEDER MECHANISM BASICALLY ERADICATES THE INITIALLY QUITE
DRY 650-550MB LAYER. HAVE ALSO BUMPED POPS TO LIKELY FOR AREAS
MAINLY NORTH OF M-72...WHILE DOWNSLOPE REGIME FOR GRAND TRAVERSE
BAY REGION PROBABLY HELPS HOLD MUCH IN THE WAY OF PRECIP AT BAY
(MAYBE JUST SOME FLURRIES OR VERY LIGHT FREEZING DRIZZLE. WILL OF
COURSE HAVE TO KEEP WATCHING AND WILL FINE-TUNE THINGS FURTHER
WITH TIME...BUT STILL LIKE THE IDEA THAT COMBO OF LIGHT SNOW AND
FREEZING DRIZZLE MAY MAKE FOR SOME SLIPPERY TRAVEL LATER TONIGHT
INTO FRIDAY MORNING...PARTICULARLY INTO THE HIGHER TERRAIN WHERE
ROBUST INVERSION-LEVEL EASTERLY JET OF 30 KNOTS WILL ONLY AID IN
UPSLOPE FORCING.
UPDATE ISSUED AT 653 PM EST THU NOV 29 2012
AS CONVOLUTED OF A FORECAST AS THEY COME THIS TIME OF YEAR IN
NORTHERN MICHIGAN...WITH THE MAIN CONCERN BEING THE POTENTIAL FOR
FREEZING DRIZZLE AND/OR SNOW (MAYBE BOTH) OVERNIGHT. PER 23Z
SURFACE ANALYSIS...SHARP ARCTIC BOUNDARY LIES BETWEEN M-55 AND
US-10...BEING DRIVEN SLOWLY SOUTHWARD WITH TIME COURTESY OF STRONG
(1037MB) ARCTIC HIGH DRIFTING THROUGH ONTARIO. AS PREDICTED BY THE
DAY CREW...WEAKISH BUT DEEPENING WARM ADVECTION ASCENT NORTH OF
THIS BOUNDARY (AND ABOVE A RATHER CHILLY LOW LEVEL SUB-925MB
AIRMASS) IS FUELING THE GRADUAL DEVELOPMENT OF LOWER CLOUDS. RADAR
RETURNS ALSO ON THE INCREASE ACROSS THE HIGHER TERRAIN AS THE SUB-
925MB FLOW IS VEERING MORE EASTERLY WITH TIME AND UPSLOPE
COMPONENT IS ON THE INCREASE. PER OBS OUT THE WINDOW HERE (HARD TO
BEAT ACTUAL OBS)...PRECIP TYPE IS JUST FLURRIES...WITH A SATURATED
PROFILE UP TO -10C PER INCOMING 00Z APX RAOB...JUST SUFFICIENT FOR
ICE NUCLEI PRODUCTION. THAT DOESN`T MAKE OUR JOB ANY EASIER
OVERNIGHT WITH REGARD TO PRECIP TYPE FORECASTING...AS IT WAS
THOUGHT PRECIP MAY INITIALLY BE MORE OF THE LIQUID VARIETY (FZDZ)
BEFORE POSSIBLY BECOMING MORE SNOW LATER AS SEEDER-FEEDER
MECHANISM KICKS INTO GEAR.
AT THIS POINT...DON`T PLAN TO MAKE ANY MAJOR CHANGES TO GOING
FORECAST...BUT WILL HAVE TO CLOSELY WATCH OBS THE NEXT FEW HOURS.
PER OBS...MAY HAVE TO SLOW DOWN PRECIP MENTION NORTH OF M-68
(MAYBE NORTH OF M-32) AS LOW LEVEL NORTHERLY FLOW IS BLEEDING IN
SIGNIFICANTLY DRIER AIR (SEE DEW POINTS FALLING THROUGH THE
TEENS)...IMPEDING LOWER CLOUD DEVELOPMENT. WITH REALLY NO CHANGE
TO LOW LEVEL THERMAL PROFILES PER SHORT TERM GUIDANCE TRENDS THE
NEXT FEW HOURS...MAY HAVE TO REMOVE THE FZDZ MENTION THROUGH 04Z
OR SO. HOWEVER...RUC/HI-RES 4KM NAM RAOBS CONTINUE TO HINT AT LOSS
OF MOISTURE BETWEEN -7C AND -4C BY 06Z...FAVORING MORE OF A LIQUID
SCENARIO WITH TIME. ONE CONCERN AREA IS ALSO SOUTH OF GRAND
TRAVERSE BAY...AS LOW LEVEL STRONGER EASTERLY FLOW WILL BE A
DOWNSLOPE ONE AND MAY ACT TO HOLD CEILINGS UP AND THUS ELIMINATE
THE POTENTIAL FOR ANY FREEZING DRIZZLE WHATSOEVER.
WILL ALSO LIKELY HAVE TO UP WINDS OVERNIGHT AS A STRONG GRADIENT
DEVELOPS DIRECTLY OVERHEAD...WITH A PRONOUNCED 25-30 KNOT EASTERLY
LOW LEVEL JET RIGHT AT INVERSION LEVEL. GIVEN AN UNSTABLE SUB-
925MB PROFILE...SHOULD HAVE NO BIG TROUBLE GETTING STRONGER GUSTS
TO MIX DOWN...PARTICULARLY AFTER 04Z. GOING LOWS LOOK JUST FINE AT
THIS POINT...PERHAPS EVEN SLIGHTLY COLDER FOR EASTERN UPPER (A FEW
SINGLE DIGITS?) AS VERY DENSE/COLD ARCTIC AIR OOZES INTO THAT AREA
FROM ONTARIO.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 406 PM EST THU NOV 29 2012
SHALLOW ARCTIC BOUNDARY CONTINUES ITS SLOW TREK SOUTH ACROSS
NORTHERN LOWER THIS AFTERNOON...COURTESY OF 1033MB HIGH BUILDING
EAST INTO WESTERN ONTARIO. LACK OF DYNAMICS AND DEARTH OF DEEP LAYER
MOISTURE ALLOWING A DRY FRONTAL PASSAGE...ALTHOUGH WELL DEFINED
STRATUS DECK BUILDING SOUTH IN ITS WAKE. TEMPERATURE CHANGE NOT AN
OVERLY ABRUPT ONE DIRECTLY BEHIND THE FRONT...WITH READING COOLING
BACK INTO THE LOWER AND MIDDLE 30S OVER NORTHERN LOWER MICHIGAN.
HEART OF THE COLDEST AIR REMAINS JUST NORTH OF THE BORDER...WITH
READINGS STUCK IN THE SINGLE DIGITS EVEN AT THIS HOUR. QUIET WEATHER
LOOKS TO BE SHORT-LIVED...WITH MOUNTING EVIDENCE FOR A POTENTIAL
HIGH IMPACT FREEZING DRIZZLE EVENT TONIGHT INTO FRIDAY MORNING.
FORECAST CONCERNS CENTER ON SUCH...SPECIFICALLY SPATIAL AND TEMPORAL
RESOLUTION OF FREEZING DRIZZLE TONIGHT INTO FRIDAY...AS WELL AS
ASSOCIATED HEADLINE POSSIBILITIES.
NO SHORTAGE OF THINGS TO TALK ABOUT TONIGHT. SHALLOW FRONT CONTINUES
TO SAG SOUTH...EVENTUALLY STALLING OUT OVER THE NORTHERN OHIO VALLEY
FRIDAY MORNING AS SUBTLE MID LEVEL WAVE ENTICES WEAKISH LOW PRESSURE
DEVELOPMENT ALONG IT. THIS WILL FORCE WEAK BUT SUSTAINED WAA UP AND
OVER THE SHALLOW NORTHERN LAKES SURFACE BASED COLD DOME. LOW LEVEL
MOISTURE ALREADY IN PLACE AS EVIDENT BY EXPANDING STRATUS DECK...
WITH SAID WAA ONLY DEEPENING THE MOIST LAYER. MODEL DERIVED
SOUNDINGS CONFIRM AS SUCH...WITH INCREASING MIXING RATIOS WITH HEIGHT
AND NEAR SATURATED CONDITIONS TO THE SURFACE. COMBINE THIS WILL A
MOIST LAYER LYING ENTIRELY WARMER THAN -10C AND A MID LEVEL DRY
WEDGE/WEAK WIND SHEAR DIRECTLY ABOVE THE MOIST LAYER...AND THE
SUPPORT IS HIGH FOR A DEVELOPING FREEZING DRIZZLE EVENT OVERNIGHT AS
SURFACE TEMPERATURES DROP. MAINTENANCE OF LOW LEVEL INSTABILITY
REGIME ACROSS NORTHERN LAKE HURON WILL ONLY AUGMENT THE LOW LEVEL
MOISTURE ACROSS NORTHEAST LOWER AND THE INTERIOR HIGHLANDS ALONG AND
EAST OF INTERSTATE 75. LAKE CONVECTION MAY BE DEEP ENOUGH TO SUPPORT
LIGHT SNOW SHOWER DEVELOPMENT IN THESE AREAS...ALTHOUGH EVEN HERE
SOUNDINGS ARE MORE SUPPORTIVE OF FREEZING DRIZZLE. WILL USE OFF THE
DECK WAA MOISTENING FOR TEMPORAL AND SPATIAL DETAIL...EXPECTING
INITIAL FREEZING DRIZZLE TO DEVELOP ACROSS THE SOUTHEAST LATER THIS
EVENING...EXPANDING NORTH ACROSS THE REST OF NORTHERN LOWER BY
MORNING. DRY NORTHEAST FLOW LIKELY TO KEEP MUCH OF EASTERN UPPER DRY
OVERNIGHT. POLICY IS NOT TO BE TOO AGGRESSIVE WITH FREEZING DRIZZLE
HEADLINES...ESPECIALLY WITH NOTORIOUS HIGH BUST POTENTIAL OF SUCH.
PREFER TO HIGHLIGHT THE POTENTIAL FOR NOW WITH AN SPECIAL WEATHER
STATEMENT AND THROUGH HWO/HEADLINE NEWS FEATURES...PASSING POSSIBLE
HEADLINE DECISIONS TO THE EVENING CREW.
TEMPERATURES TONIGHT RATHER TRICKY...ALTHOUGH EXTENSIVE OVERCAST
LIKELY TO KEEP THINGS FROM GETTING TOO OUT OF HAND. WHILE LOW LEVEL
MOISTURE IS LIKELY TO STRIP OUT OF EASTERN UPPER OVERNIGHT...STILL
PLENTY OF MID LEVEL CLOUDS EXPECTED. THIS SHOULD KEEP READING
SOMEWHAT IN CHECK...ALTHOUGH SIMPLE MAGNITUDE OF COLD AIR JUST TO
THEIR NORTH ARGUES FOR TEMPERATURES DROPPING INTO THE LOWER AND
MIDDLE TEENS NORTH OF THE MIGHT MAC. CONSIDERABLY WARMER TO THE
SOUTH...WITH LOWS GENERALLY IN THE 20S.
ABOVE CONDITIONS APPLY RIGHT THROUGH FRIDAY...WITH GREATER EMPHASIS
ONCE AGAIN FOCUSED ACROSS INTERIOR AND NORTHEAST LOWER. MAY SEE SOME
SEEDING FROM INCREASED MID LEVEL MOISTURE LATER IN THE MORNING AND
AFTERNOON TO FORCE MORE OF A LIGHT SNOW ISSUE (JUST MINOR
ACCUMULATIONS)...BUT STILL CANNOT RULE OUT FREEZING DRIZZLE.
TEMPERATURES SLOWLY WARM...WITH READINGS ACROSS SOUTHERN ZONES
TOPPING THE FREEZING MARK BY LATE MORNING AND AFTERNOON. INFLUX OF
SHALLOW COLD AIR LIKELY TO KEEP EASTERN UPPER STUCK IN THE
20S.
&&
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 406 PM EST THU NOV 29 2012
LARGE SCALE PATTERN/FORECAST: HEMISPHERIC PATTERN REMAINS DOMINATED
BY POLAR VORTICES OVER ARCTIC CANADA AND SIBERIA...AND A LARGE
TROUGH OVER THE EASTERN PACIFIC (FOCUSING COPIOUS AMOUNTS OF
PRECIPITATION INTO THE WEST COAST)...MAKING UP THREE WAVES OF AN
ODDLY SHAPED FOUR WAVE PATTERN. THIS OVERALL IDEA LOOKS PRETTY
ENTRENCHED THIS FORECAST CYCLE...AS CENTRAL PACIFIC/-WPO REX
BLOCKING HELPS ANCHOR THE PATTERN. FLOW ACROSS THE CONUS HOWEVER IS
BECOMING FLATTER/MORE ZONAL WITH TIME...ONE RIPPLE EMANATING FROM
THE EASTERN PACIFIC STORM WILL CROSS THE CONUS AND PASS THE GREAT
LAKES/OHIO VALLEY FRIDAY...WITH A STRONGER WAVE COMING IN THE
TUESDAY TIME FRAME AS PACIFIC TROUGH RE-LOADS ALLOWING FOR A
TEMPORARY BREAK IN WHAT IS OTHERWISE A MILD LOOKING PATTERN.
WEST-EAST ORIENTED COLD FRONT DRAPED ACROSS NORTHERN LOWER MICHIGAN
TODAY...SANDWICHED BETWEEN HIGH PRESSURE OVER THE CAROLINAS AND
ARCTIC HIGH OVER NORTHERN MANITOBA RIDGING EAST ACROSS NORTHERN
ONTARIO. FRONT WILL SAG INTO SOUTHERN LOWER MICHIGAN AND STALL...
ALLOWING COLD NORTHEAST/EAST BOUNDARY LAYER FLOW TO DEVELOP INTO
NORTHERN MICHIGAN (SINGLE DIGIT TEMPERATURES ABOVE AND BELOW ZERO TO
THE NORTH AND EAST OF LAKE SUPERIOR). UPPER LEVEL DISTURBANCE
CROSSING THE NORTHERN/CENTRAL ROCKIES TODAY WILL CROSS SOUTHERN
LOWER MICHIGAN/INDIANA/OHIO FRIDAY...AND ANOTHER WEAK RIPPLE
SATURDAY NIGHT ALONG WITH A SURFACE TROUGH/COLD FRONT. NEAR TERM
FORECAST CONCERNS WILL DEAL WITH WARM ADVECTION ABOVE SHALLOW FRONT
SOUTH OF THE STATE FRIDAY NIGHT INTO EARLY SATURDAY...THEN RAIN
SHOWER THREAT SATURDAY NIGHT INTO SUNDAY.
FRIDAY NIGHT THROUGH SUNDAY: FORECAST STARTS WITH SHORT WAVE ENERGY
MOVING AWAY FROM NORTHERN MICHIGAN TO THE SOUTHEAST...WITH LOW LEVEL
EASTERLY FLOW CONTINUING AROUND REMNANT ARCTIC HIGH OVER QUEBEC.
STILL LOOKS TO BE A LOT OF LOW LEVEL MOISTURE AROUND STUCK BENEATH
FRONTAL INVERSION...WARM ADVECTION/UPSLOPE FLOW/SHALLOW LAKE
CONVECTION WILL ALL CONTRIBUTE SOME FORCING FOR A CONTINUED THREAT
FOR DRIZZLE/FREEZING DRIZZLE (AND PERHAPS SOME FOG AS WELL WITH
STRATUS BUILD DOWN...ESPECIALLY ON THE HILLTOPS). THIS CONTINUES
INTO SATURDAY MORNING...BUT WITH AN INCREASING SOUTHERLY WIND
EXPECTING TEMPERATURES TO CLIMB ABOVE FREEZING DURING THE MORNING
HOURS. LOOKING LIKE LOW CLOUDS WILL BE STUBBORN ACROSS EASTERN
UPPER (ALONG WITH THE DRIZZLE) AND MUCH OF NORTHEAST LOWER INTO THE
AFTERNOON... WHILE THINK WE`LL SEE SOME SUN DEVELOP ACROSS NORTHWEST
LOWER AND DOWN TOWARDS SAGINAW BAY.
COLD FRONT WILL BE MOVING ACROSS MICHIGAN SATURDAY NIGHT...WITH AN
AXIS OF LOW LEVEL MOISTURE ALONG IT. RIGHT ENTRANCE JET QUADRANT
WILL ENHANCE DIVERGENCE ACROSS THE FORECAST AREA...WITH THE END
RESULT BEING A BAND OF SHOWERS DEVELOPING AHEAD OF THE FRONT AND
CROSSING THE FORECAST AREA. EXPECT TEMPERATURES TO BE STEADY OR
SLOWLY CLIMB OVERNIGHT. COLD FRONT PASSAGE SUNDAY MORNING WILL
BRING AN END TO RAIN CHANCES DURING THE MORNING...THOUGH SOME
UNCERTAINTY WITH RESPECT TO EXACT FRONTAL TIMING SO WILL TRY TO BE
SOMEWHAT PROBABILISTIC WITH RESPECT TO RAIN CHANCES SUNDAY AS
OPPOSED TO GRABBING ONTO ONE MODEL SOLUTION. WILL TRY TO CONFINE
RAIN SHOWERS TO JUST THE MORNING HOURS.
EXTENDED FORECAST (MONDAY THROUGH THURSDAY): STRONG HEIGHT FALLS
PUSHING ACROSS THE MIDWEST ON MONDAY WILL SEND A SURGE OF SOUTHERLY
MOMENTUM AND WARM AIR UP INTO THE GREAT LAKES. AS MENTIONED IN THIS
SPACE YESTERDAY BIGGEST UNKNOWN IS POTENTIAL FOR LOW CLOUDS/
ADVECTION FOG ALONG AXIS OF HIGHER DEW POINT AIR ALONG COLD FRONT
ASSOCIATED WITH APPROACHING SHORT WAVE. BUT WILL CONTINUE WITH
POSITIVE THOUGHTS AND HIGHS IN THE 50S MOST AREAS MONDAY AFTERNOON.
STRONG COLD FRONT WILL SWEEP THROUGH THE UPPER LAKES MONDAY NIGHT
INTO EARLY TUESDAY... TIMING OF THE FRONT WILL HAVE HUGE
IMPLICATIONS WITH RESPECT TO HIGH TEMPERATURES (AS THE MERCURY IS
LIKELY TO FALL THROUGH THE DAY) AND PRECIPITATION (LINGERING SHOWERS
IF FRONT IS SLOWER...QUICKER ONSET OF LAKE CONVECTION IF BOUNDARY IS
THROUGH THE AREA TUESDAY MORNING). A QUICKER TREND MAY BE THE WAY
TO GO...WHICH DRIES THE BULK OF TUESDAY OUT. HEADING INTO
MIDWEEK...HIGH PRESSURE SLIDES ACROSS THE MIDWEST AND INTO THE UPPER
LAKES...WITH ANOTHER ROUND OF WARM ADVECTION SETTING UP FOR
THURSDAY. WEDNESDAY WILL PROBABLY BE A TRANSITION FROM LAKE
CONVECTION TO DRY WEATHER...AND WILL PROBABLY START THE NEW THURSDAY
FORECAST DRY AS WELL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1145 PM EST THU NOV 29 2012
VFR/MVFR CONDITIONS INITIALLY WILL FALL TO IFR FOR APN/PLN THE
REMAINDER OF THE NIGHT AS SOME FREEZING DRIZZLE AND LIGHT SNOW
DEVELOP AHEAD OF AN APPROACHING UPPER WAVE. MEANWHILE...TVC AND
MBL LOOK TO BE JUST A BIT TOO FAR WEST TO RECEIVE ANY SIGNIFICANT
FREEZING DRIZZLE...AIDED BY FURTHER DRYING DOWN LOW AS EASTERLY
DOWNSLOPE WINDS PREVAIL. CONDITIONS MAY BRIEFLY TRY TO IMPROVE
FRIDAY AFTERNOON...BUT SHOULD STILL REMAIN IFR TO MVFR WITHIN
LOWER CLOUDS...BEFORE THICKER LOW STRATUS AND PERHAPS SOME MORE
FREEZING DRIZZLE RETURNS FOR ALL TERMINAL SITES AFTER 00Z. WINDS
WILL BECOME A LITTLE GUSTY FROM THE EAST AT ALL SITES...WITH
PERHAPS A FEW GUSTS PUSHING 20 KNOTS ON FRIDAY.
&&
.MARINE...
ISSUED AT 933 PM EST THU NOV 29 2012
UPDATE: HAVE ISSUED SMALL CRAFT ADVISORIES FROM SEUL CHOIX POINT
TO THE BRIDGE WHERE EASTERLY FLOW IS BEGINNING TO CHANNEL THROUGH
THE STRAITS...AND SHOULD ONLY INCREASE WITH TIME THROUGH THE NIGHT
WITHING A DECENT GRADIENT.
INCREASINGLY GUSTY NORTHEAST TO EAST WINDS WILL RESULT
IN SCA CONDITIONS FOR MOST OF THE NEARSHORE WATERS OF BOTH NORTHERN
LAKE MICHIGAN AND HURON FROM LATE TONIGHT RIGHT THROUGH FRIDAY
AFTERNOON. WINDS BEGIN TO SUBSIDE SOME FRIDAY NIGHT INTO
SATURDAY...EVENTUALLY VEERING SOUTHERLY BY LATER SATURDAY. MAY NEED
SOME EXTENSIONS TO ONGOING ADVISORIES...ESPECIALLY ACROSS LAKE
HURON...THROUGH THIS PERIOD.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY UNTIL 9 AM EST FRIDAY FOR MIZ016>019-
021>024-027>030.
LH...SMALL CRAFT ADVISORY UNTIL 4 PM EST FRIDAY FOR LHZ345>349.
LM...SMALL CRAFT ADVISORY UNTIL 4 PM EST FRIDAY FOR LMZ323-341-342-
344-345.
LS...NONE.
&&
$$
UPDATE...LAWRENCE
SYNOPSIS...TJL
SHORT TERM...MSB
LONG TERM...JPB
AVIATION...LAWRENCE
MARINE...MSB/LAWRENCE
AREA FORECAST DISCUSSION
NWS GAYLORD MI
1102 PM EST THU NOV 29 2012
.SYNOPSIS...
ISSUED AT 406 PM EST THU NOV 29 2012
THE SEASONABLY CHILLY AIR WILL CONTINUE TO HANG ACROSS THE REGION
THROUGH FRIDAY...BRINGING A BIT MORE LIGHT SNOW SHOWERS OR FLURRIES
AT TIMES. PERHAPS EVEN SOME FREEZING DRIZZLE LATER TONIGHT INTO
FRIDAY MORNING. MILDER TEMPERATURES AND RAIN CHANCES...WILL MAKE A
RETURN TO NORTHERN MICHIGAN THIS WEEKEND...AND INTO EARLY NEXT
WEEK...AS A PAIR OF SYSTEMS MOVE OVER THE NORTHERN PLAINS AND PASS
NORTHWEST OF THE STATE.
&&
.UPDATE...
ISSUED AT 1102 PM EST THU NOV 29 2012
EARLIER FCST UPDATE ACTUALLY WORKING OUT RATHER WELL (THAT DOESN`T
ALWAYS HAPPEN HERE!)...AND PER LATEST RADAR/RAP TRENDS...HAVE
DECIDED TO HOIST A WINTER WEATHER ADVISORY BASICALLY FROM M-72 ON
NORTH THROUGH MID MORNING. ALREADY SEEING A NICE COATING OF ICE
HERE AT THE OFFICE AND ACROSS THE HIGHER TERRAIN PER SPOTTER
REPORTS. PER RAP GUIDANCE (WHICH HAD THE BEST HANDLE OF BLOSSOMING
OF PRECIP EARLIER)...BEST LOW LEVEL WARM ADVECTION ASCENT IN THE
925-875MB LAYER WILL OCCUR BASICALLY NORTH OF M-72 OVERNIGHT. THAT
DOESN`T PRECLUDE SOME PATCHY FREEZING DRIZZLE TO THE SOUTH...
ESPECIALLY GIVEN STALLING ARCTIC FRONTAL BOUNDARY DOWN THAT WAY
AND BETTER POOLED MOISTURE...BUT CURRENT ADVISORY AREA IS MY BEST
GUESS WHERE THINGS MAY GET QUITE SLICK BY MORNING. CAN FORESEE A
BIT OF A MIX WITH SOME SNOW AT TIMES LATER TONIGHT AS WELL AS MID
LEVEL MOISTURE DEPTH DEEPENS...BUT THAT WOULD ONLY HELP MATTERS.
OUTSIDE OF THE ADVISORY...NO MAJOR CHANGES NEEDED.
UPDATE ISSUED AT 933 PM EST THU NOV 29 2012
EVENT STARTING TO GET UNDERWAY OVER THE PAST 2 HOURS...WITH A
NARROW BUT WELL-DEFINED AXIS OF LIGHT RADAR RETURNS CENTERED JUST
SOUTH OF THE M-32 CORRIDOR. THIS IS ALONG A SHALLOW (925-875MB)
AXIS OF FRONTOGENESIS AS LOW LEVEL ARCTIC AIR CONTINUES TO BLEED
BENEATH WARMER REGIME ALOFT. PER OBS OUT THE WINDOW...WE HAVE SEEN
BOTH SOME LIGHT SNOW AND FREEZING DRIZZLE...CONSISTENT WITH 00Z
APX RAOB SHOWING SATURATION NEARING -10C...AND A DEEPENING OF THE
COLD WITHIN THE SATURATED LAYER (LEADING TO MORE OF A FROZEN
DRIZZLE SCENARIO EARLIER). SUSPECT THIS WILL BE THE CASE
OVERNIGHT...AND PER SHORT TERM GUIDANCE TRENDS...HAVE REWORKED
POPS/WEATHER TO FOCUS INITIALLY ON THE HIGHER TERRAIN.
HOWEVER...SUSPECT PRECIP WILL BECOME MUCH MORE WIDESPREAD AFTER
06Z AS A RATHER ROBUST UPPER WAVE BEGINS ITS APPROACH...AND LOW
LEVEL WARM ADVECTION ASCENT CRANKS UP (ALBEIT STILL FAIRLY WEAK).
ALSO SEEING A GRADUAL TOP-DOWN SATURATION ONGOING PER HIGHER RADAR
SCANS...AND GIVEN THIS AND STRONG QPF SIGNAL FROM ALL AVAILABLE
GUIDANCE...HAVE TO BELIEVE WE WILL END UP SEEING A PERIOD OF
LIGHTER SNOWS ACROSS MUCH OF NORTHERN LOWER LATER TONIGHT AS
SEEDER-FEEDER MECHANISM BASICALLY ERADICATES THE INITIALLY QUITE
DRY 650-550MB LAYER. HAVE ALSO BUMPED POPS TO LIKELY FOR AREAS
MAINLY NORTH OF M-72...WHILE DOWNSLOPE REGIME FOR GRAND TRAVERSE
BAY REGION PROBABLY HELPS HOLD MUCH IN THE WAY OF PRECIP AT BAY
(MAYBE JUST SOME FLURRIES OR VERY LIGHT FREEZING DRIZZLE. WILL OF
COURSE HAVE TO KEEP WATCHING AND WILL FINE-TUNE THINGS FURTHER
WITH TIME...BUT STILL LIKE THE IDEA THAT COMBO OF LIGHT SNOW AND
FREEZING DRIZZLE MAY MAKE FOR SOME SLIPPERY TRAVEL LATER TONIGHT
INTO FRIDAY MORNING...PARTICULARLY INTO THE HIGHER TERRAIN WHERE
ROBUST INVERSION-LEVEL EASTERLY JET OF 30 KNOTS WILL ONLY AID IN
UPSLOPE FORCING.
UPDATE ISSUED AT 653 PM EST THU NOV 29 2012
AS CONVOLUTED OF A FORECAST AS THEY COME THIS TIME OF YEAR IN
NORTHERN MICHIGAN...WITH THE MAIN CONCERN BEING THE POTENTIAL FOR
FREEZING DRIZZLE AND/OR SNOW (MAYBE BOTH) OVERNIGHT. PER 23Z
SURFACE ANALYSIS...SHARP ARCTIC BOUNDARY LIES BETWEEN M-55 AND
US-10...BEING DRIVEN SLOWLY SOUTHWARD WITH TIME COURTESY OF STRONG
(1037MB) ARCTIC HIGH DRIFTING THROUGH ONTARIO. AS PREDICTED BY THE
DAY CREW...WEAKISH BUT DEEPENING WARM ADVECTION ASCENT NORTH OF
THIS BOUNDARY (AND ABOVE A RATHER CHILLY LOW LEVEL SUB-925MB
AIRMASS) IS FUELING THE GRADUAL DEVELOPMENT OF LOWER CLOUDS. RADAR
RETURNS ALSO ON THE INCREASE ACROSS THE HIGHER TERRAIN AS THE SUB-
925MB FLOW IS VEERING MORE EASTERLY WITH TIME AND UPSLOPE
COMPONENT IS ON THE INCREASE. PER OBS OUT THE WINDOW HERE (HARD TO
BEAT ACTUAL OBS)...PRECIP TYPE IS JUST FLURRIES...WITH A SATURATED
PROFILE UP TO -10C PER INCOMING 00Z APX RAOB...JUST SUFFICIENT FOR
ICE NUCLEI PRODUCTION. THAT DOESN`T MAKE OUR JOB ANY EASIER
OVERNIGHT WITH REGARD TO PRECIP TYPE FORECASTING...AS IT WAS
THOUGHT PRECIP MAY INITIALLY BE MORE OF THE LIQUID VARIETY (FZDZ)
BEFORE POSSIBLY BECOMING MORE SNOW LATER AS SEEDER-FEEDER
MECHANISM KICKS INTO GEAR.
AT THIS POINT...DON`T PLAN TO MAKE ANY MAJOR CHANGES TO GOING
FORECAST...BUT WILL HAVE TO CLOSELY WATCH OBS THE NEXT FEW HOURS.
PER OBS...MAY HAVE TO SLOW DOWN PRECIP MENTION NORTH OF M-68
(MAYBE NORTH OF M-32) AS LOW LEVEL NORTHERLY FLOW IS BLEEDING IN
SIGNIFICANTLY DRIER AIR (SEE DEW POINTS FALLING THROUGH THE
TEENS)...IMPEDING LOWER CLOUD DEVELOPMENT. WITH REALLY NO CHANGE
TO LOW LEVEL THERMAL PROFILES PER SHORT TERM GUIDANCE TRENDS THE
NEXT FEW HOURS...MAY HAVE TO REMOVE THE FZDZ MENTION THROUGH 04Z
OR SO. HOWEVER...RUC/HI-RES 4KM NAM RAOBS CONTINUE TO HINT AT LOSS
OF MOISTURE BETWEEN -7C AND -4C BY 06Z...FAVORING MORE OF A LIQUID
SCENARIO WITH TIME. ONE CONCERN AREA IS ALSO SOUTH OF GRAND
TRAVERSE BAY...AS LOW LEVEL STRONGER EASTERLY FLOW WILL BE A
DOWNSLOPE ONE AND MAY ACT TO HOLD CEILINGS UP AND THUS ELIMINATE
THE POTENTIAL FOR ANY FREEZING DRIZZLE WHATSOEVER.
WILL ALSO LIKELY HAVE TO UP WINDS OVERNIGHT AS A STRONG GRADIENT
DEVELOPS DIRECTLY OVERHEAD...WITH A PRONOUNCED 25-30 KNOT EASTERLY
LOW LEVEL JET RIGHT AT INVERSION LEVEL. GIVEN AN UNSTABLE SUB-
925MB PROFILE...SHOULD HAVE NO BIG TROUBLE GETTING STRONGER GUSTS
TO MIX DOWN...PARTICULARLY AFTER 04Z. GOING LOWS LOOK JUST FINE AT
THIS POINT...PERHAPS EVEN SLIGHTLY COLDER FOR EASTERN UPPER (A FEW
SINGLE DIGITS?) AS VERY DENSE/COLD ARCTIC AIR OOZES INTO THAT AREA
FROM ONTARIO.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 406 PM EST THU NOV 29 2012
SHALLOW ARCTIC BOUNDARY CONTINUES ITS SLOW TREK SOUTH ACROSS
NORTHERN LOWER THIS AFTERNOON...COURTESY OF 1033MB HIGH BUILDING
EAST INTO WESTERN ONTARIO. LACK OF DYNAMICS AND DEARTH OF DEEP LAYER
MOISTURE ALLOWING A DRY FRONTAL PASSAGE...ALTHOUGH WELL DEFINED
STRATUS DECK BUILDING SOUTH IN ITS WAKE. TEMPERATURE CHANGE NOT AN
OVERLY ABRUPT ONE DIRECTLY BEHIND THE FRONT...WITH READING COOLING
BACK INTO THE LOWER AND MIDDLE 30S OVER NORTHERN LOWER MICHIGAN.
HEART OF THE COLDEST AIR REMAINS JUST NORTH OF THE BORDER...WITH
READINGS STUCK IN THE SINGLE DIGITS EVEN AT THIS HOUR. QUIET WEATHER
LOOKS TO BE SHORT-LIVED...WITH MOUNTING EVIDENCE FOR A POTENTIAL
HIGH IMPACT FREEZING DRIZZLE EVENT TONIGHT INTO FRIDAY MORNING.
FORECAST CONCERNS CENTER ON SUCH...SPECIFICALLY SPATIAL AND TEMPORAL
RESOLUTION OF FREEZING DRIZZLE TONIGHT INTO FRIDAY...AS WELL AS
ASSOCIATED HEADLINE POSSIBILITIES.
NO SHORTAGE OF THINGS TO TALK ABOUT TONIGHT. SHALLOW FRONT CONTINUES
TO SAG SOUTH...EVENTUALLY STALLING OUT OVER THE NORTHERN OHIO VALLEY
FRIDAY MORNING AS SUBTLE MID LEVEL WAVE ENTICES WEAKISH LOW PRESSURE
DEVELOPMENT ALONG IT. THIS WILL FORCE WEAK BUT SUSTAINED WAA UP AND
OVER THE SHALLOW NORTHERN LAKES SURFACE BASED COLD DOME. LOW LEVEL
MOISTURE ALREADY IN PLACE AS EVIDENT BY EXPANDING STRATUS DECK...
WITH SAID WAA ONLY DEEPENING THE MOIST LAYER. MODEL DERIVED
SOUNDINGS CONFIRM AS SUCH...WITH INCREASING MIXING RATIOS WITH HEIGHT
AND NEAR SATURATED CONDITIONS TO THE SURFACE. COMBINE THIS WILL A
MOIST LAYER LYING ENTIRELY WARMER THAN -10C AND A MID LEVEL DRY
WEDGE/WEAK WIND SHEAR DIRECTLY ABOVE THE MOIST LAYER...AND THE
SUPPORT IS HIGH FOR A DEVELOPING FREEZING DRIZZLE EVENT OVERNIGHT AS
SURFACE TEMPERATURES DROP. MAINTENANCE OF LOW LEVEL INSTABILITY
REGIME ACROSS NORTHERN LAKE HURON WILL ONLY AUGMENT THE LOW LEVEL
MOISTURE ACROSS NORTHEAST LOWER AND THE INTERIOR HIGHLANDS ALONG AND
EAST OF INTERSTATE 75. LAKE CONVECTION MAY BE DEEP ENOUGH TO SUPPORT
LIGHT SNOW SHOWER DEVELOPMENT IN THESE AREAS...ALTHOUGH EVEN HERE
SOUNDINGS ARE MORE SUPPORTIVE OF FREEZING DRIZZLE. WILL USE OFF THE
DECK WAA MOISTENING FOR TEMPORAL AND SPATIAL DETAIL...EXPECTING
INITIAL FREEZING DRIZZLE TO DEVELOP ACROSS THE SOUTHEAST LATER THIS
EVENING...EXPANDING NORTH ACROSS THE REST OF NORTHERN LOWER BY
MORNING. DRY NORTHEAST FLOW LIKELY TO KEEP MUCH OF EASTERN UPPER DRY
OVERNIGHT. POLICY IS NOT TO BE TOO AGGRESSIVE WITH FREEZING DRIZZLE
HEADLINES...ESPECIALLY WITH NOTORIOUS HIGH BUST POTENTIAL OF SUCH.
PREFER TO HIGHLIGHT THE POTENTIAL FOR NOW WITH AN SPECIAL WEATHER
STATEMENT AND THROUGH HWO/HEADLINE NEWS FEATURES...PASSING POSSIBLE
HEADLINE DECISIONS TO THE EVENING CREW.
TEMPERATURES TONIGHT RATHER TRICKY...ALTHOUGH EXTENSIVE OVERCAST
LIKELY TO KEEP THINGS FROM GETTING TOO OUT OF HAND. WHILE LOW LEVEL
MOISTURE IS LIKELY TO STRIP OUT OF EASTERN UPPER OVERNIGHT...STILL
PLENTY OF MID LEVEL CLOUDS EXPECTED. THIS SHOULD KEEP READING
SOMEWHAT IN CHECK...ALTHOUGH SIMPLE MAGNITUDE OF COLD AIR JUST TO
THEIR NORTH ARGUES FOR TEMPERATURES DROPPING INTO THE LOWER AND
MIDDLE TEENS NORTH OF THE MIGHT MAC. CONSIDERABLY WARMER TO THE
SOUTH...WITH LOWS GENERALLY IN THE 20S.
ABOVE CONDITIONS APPLY RIGHT THROUGH FRIDAY...WITH GREATER EMPHASIS
ONCE AGAIN FOCUSED ACROSS INTERIOR AND NORTHEAST LOWER. MAY SEE SOME
SEEDING FROM INCREASED MID LEVEL MOISTURE LATER IN THE MORNING AND
AFTERNOON TO FORCE MORE OF A LIGHT SNOW ISSUE (JUST MINOR
ACCUMULATIONS)...BUT STILL CANNOT RULE OUT FREEZING DRIZZLE.
TEMPERATURES SLOWLY WARM...WITH READINGS ACROSS SOUTHERN ZONES
TOPPING THE FREEZING MARK BY LATE MORNING AND AFTERNOON. INFLUX OF
SHALLOW COLD AIR LIKELY TO KEEP EASTERN UPPER STUCK IN THE
20S.
&&
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 406 PM EST THU NOV 29 2012
LARGE SCALE PATTERN/FORECAST: HEMISPHERIC PATTERN REMAINS DOMINATED
BY POLAR VORTICES OVER ARCTIC CANADA AND SIBERIA...AND A LARGE
TROUGH OVER THE EASTERN PACIFIC (FOCUSING COPIOUS AMOUNTS OF
PRECIPITATION INTO THE WEST COAST)...MAKING UP THREE WAVES OF AN
ODDLY SHAPED FOUR WAVE PATTERN. THIS OVERALL IDEA LOOKS PRETTY
ENTRENCHED THIS FORECAST CYCLE...AS CENTRAL PACIFIC/-WPO REX
BLOCKING HELPS ANCHOR THE PATTERN. FLOW ACROSS THE CONUS HOWEVER IS
BECOMING FLATTER/MORE ZONAL WITH TIME...ONE RIPPLE EMANATING FROM
THE EASTERN PACIFIC STORM WILL CROSS THE CONUS AND PASS THE GREAT
LAKES/OHIO VALLEY FRIDAY...WITH A STRONGER WAVE COMING IN THE
TUESDAY TIME FRAME AS PACIFIC TROUGH RE-LOADS ALLOWING FOR A
TEMPORARY BREAK IN WHAT IS OTHERWISE A MILD LOOKING PATTERN.
WEST-EAST ORIENTED COLD FRONT DRAPED ACROSS NORTHERN LOWER MICHIGAN
TODAY...SANDWICHED BETWEEN HIGH PRESSURE OVER THE CAROLINAS AND
ARCTIC HIGH OVER NORTHERN MANITOBA RIDGING EAST ACROSS NORTHERN
ONTARIO. FRONT WILL SAG INTO SOUTHERN LOWER MICHIGAN AND STALL...
ALLOWING COLD NORTHEAST/EAST BOUNDARY LAYER FLOW TO DEVELOP INTO
NORTHERN MICHIGAN (SINGLE DIGIT TEMPERATURES ABOVE AND BELOW ZERO TO
THE NORTH AND EAST OF LAKE SUPERIOR). UPPER LEVEL DISTURBANCE
CROSSING THE NORTHERN/CENTRAL ROCKIES TODAY WILL CROSS SOUTHERN
LOWER MICHIGAN/INDIANA/OHIO FRIDAY...AND ANOTHER WEAK RIPPLE
SATURDAY NIGHT ALONG WITH A SURFACE TROUGH/COLD FRONT. NEAR TERM
FORECAST CONCERNS WILL DEAL WITH WARM ADVECTION ABOVE SHALLOW FRONT
SOUTH OF THE STATE FRIDAY NIGHT INTO EARLY SATURDAY...THEN RAIN
SHOWER THREAT SATURDAY NIGHT INTO SUNDAY.
FRIDAY NIGHT THROUGH SUNDAY: FORECAST STARTS WITH SHORT WAVE ENERGY
MOVING AWAY FROM NORTHERN MICHIGAN TO THE SOUTHEAST...WITH LOW LEVEL
EASTERLY FLOW CONTINUING AROUND REMNANT ARCTIC HIGH OVER QUEBEC.
STILL LOOKS TO BE A LOT OF LOW LEVEL MOISTURE AROUND STUCK BENEATH
FRONTAL INVERSION...WARM ADVECTION/UPSLOPE FLOW/SHALLOW LAKE
CONVECTION WILL ALL CONTRIBUTE SOME FORCING FOR A CONTINUED THREAT
FOR DRIZZLE/FREEZING DRIZZLE (AND PERHAPS SOME FOG AS WELL WITH
STRATUS BUILD DOWN...ESPECIALLY ON THE HILLTOPS). THIS CONTINUES
INTO SATURDAY MORNING...BUT WITH AN INCREASING SOUTHERLY WIND
EXPECTING TEMPERATURES TO CLIMB ABOVE FREEZING DURING THE MORNING
HOURS. LOOKING LIKE LOW CLOUDS WILL BE STUBBORN ACROSS EASTERN
UPPER (ALONG WITH THE DRIZZLE) AND MUCH OF NORTHEAST LOWER INTO THE
AFTERNOON... WHILE THINK WE`LL SEE SOME SUN DEVELOP ACROSS NORTHWEST
LOWER AND DOWN TOWARDS SAGINAW BAY.
COLD FRONT WILL BE MOVING ACROSS MICHIGAN SATURDAY NIGHT...WITH AN
AXIS OF LOW LEVEL MOISTURE ALONG IT. RIGHT ENTRANCE JET QUADRANT
WILL ENHANCE DIVERGENCE ACROSS THE FORECAST AREA...WITH THE END
RESULT BEING A BAND OF SHOWERS DEVELOPING AHEAD OF THE FRONT AND
CROSSING THE FORECAST AREA. EXPECT TEMPERATURES TO BE STEADY OR
SLOWLY CLIMB OVERNIGHT. COLD FRONT PASSAGE SUNDAY MORNING WILL
BRING AN END TO RAIN CHANCES DURING THE MORNING...THOUGH SOME
UNCERTAINTY WITH RESPECT TO EXACT FRONTAL TIMING SO WILL TRY TO BE
SOMEWHAT PROBABILISTIC WITH RESPECT TO RAIN CHANCES SUNDAY AS
OPPOSED TO GRABBING ONTO ONE MODEL SOLUTION. WILL TRY TO CONFINE
RAIN SHOWERS TO JUST THE MORNING HOURS.
EXTENDED FORECAST (MONDAY THROUGH THURSDAY): STRONG HEIGHT FALLS
PUSHING ACROSS THE MIDWEST ON MONDAY WILL SEND A SURGE OF SOUTHERLY
MOMENTUM AND WARM AIR UP INTO THE GREAT LAKES. AS MENTIONED IN THIS
SPACE YESTERDAY BIGGEST UNKNOWN IS POTENTIAL FOR LOW CLOUDS/
ADVECTION FOG ALONG AXIS OF HIGHER DEW POINT AIR ALONG COLD FRONT
ASSOCIATED WITH APPROACHING SHORT WAVE. BUT WILL CONTINUE WITH
POSITIVE THOUGHTS AND HIGHS IN THE 50S MOST AREAS MONDAY AFTERNOON.
STRONG COLD FRONT WILL SWEEP THROUGH THE UPPER LAKES MONDAY NIGHT
INTO EARLY TUESDAY... TIMING OF THE FRONT WILL HAVE HUGE
IMPLICATIONS WITH RESPECT TO HIGH TEMPERATURES (AS THE MERCURY IS
LIKELY TO FALL THROUGH THE DAY) AND PRECIPITATION (LINGERING SHOWERS
IF FRONT IS SLOWER...QUICKER ONSET OF LAKE CONVECTION IF BOUNDARY IS
THROUGH THE AREA TUESDAY MORNING). A QUICKER TREND MAY BE THE WAY
TO GO...WHICH DRIES THE BULK OF TUESDAY OUT. HEADING INTO
MIDWEEK...HIGH PRESSURE SLIDES ACROSS THE MIDWEST AND INTO THE UPPER
LAKES...WITH ANOTHER ROUND OF WARM ADVECTION SETTING UP FOR
THURSDAY. WEDNESDAY WILL PROBABLY BE A TRANSITION FROM LAKE
CONVECTION TO DRY WEATHER...AND WILL PROBABLY START THE NEW THURSDAY
FORECAST DRY AS WELL.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 653 PM EST THU NOV 29 2012
RATHER LOW CONFIDENCE FORECAST AS WE HEAD INTO THE NIGHTTIME
HOURS...WITH THE MAIN ISSUE BEING THE POTENTIAL FOR SOME LIGHT
SNOW AND FREEZING DRIZZLE. CURRENTLY SEEING A MIX OF MVFR AND VFR
CEILINGS ACROSS THE TAF SITES...AND SUSPECT CEILINGS WILL BE ON A
GRADUAL DOWNWARD TREND THROUGH THE NIGHT...AS LOW LEVEL MOISTURE
POOLS JUST NORTH OF A FRONTAL BOUNDARY STALLING OVER CENTRAL LOWER
MICHIGAN. SETUP IS THERE FOR FREEZING DRIZZLE DEVELOPMENT NORTH OF
THE FRONT OVERNIGHT...ESPECIALLY FOR PLN/APN WHERE EASTERLY FLOW
OFF LAKE HURON WILL HELP GIVE A LITTLE BETTER LOW LEVEL MOISTURE.
SAME EASTERLY FLOW WILL BE A DOWNSLOPE ONE FOR TVC/MBL...WHICH MAY
ACT TO HOLD CEILINGS A BIT HIGHER AND THUS REDUCE THE OVERALL
THREAT FOR FREEZING DRIZZLE. STILL...THE CHANCE IS NOT ZERO...AND
WILL MAKE A MENTION AT ALL SITES MINUS MBL...WHERE DOWNSLOPE
DRYING WILL PROBABLY WIN OUT. WILL LIKELY ALSO SEE A LITTLE SNOW
MIX WITH ANY FREEZING DRIZZLE...WITH THE OVERALL TREND TOWARD IFR
CONDITIONS FOR ALL SITES (MINUS PERHAPS MBL) LATER TONIGHT. WINDS
WILL BECOME GUSTY AT ALL SITES OVERNIGHT...WITH THE POTENTIAL FOR
SOME GUSTS PUSHING 25 KNOTS FOR A TIME. SOME SLOW IMPROVEMENT IS
EXPECTED FROM SOUTHWEST TO NORTHEAST THROUGH THE DAY ON
FRIDAY...BUT CEILINGS MAY HOLD IN THE IFR RANGE THROUGH MUCH OF
THE DAY AROUND PLN/APN.
&&
.MARINE...
ISSUED AT 933 PM EST THU NOV 29 2012
UPDATE: HAVE ISSUED SMALL CRAFT ADVISORIES FROM SEUL CHOIX POINT
TO THE BRIDGE WHERE EASTERLY FLOW IS BEGINNING TO CHANNEL THROUGH
THE STRAITS...AND SHOULD ONLY INCREASE WITH TIME THROUGH THE NIGHT
WITHING A DECENT GRADIENT.
INCREASINGLY GUSTY NORTHEAST TO EAST WINDS WILL RESULT
IN SCA CONDITIONS FOR MOST OF THE NEARSHORE WATERS OF BOTH NORTHERN
LAKE MICHIGAN AND HURON FROM LATE TONIGHT RIGHT THROUGH FRIDAY
AFTERNOON. WINDS BEGIN TO SUBSIDE SOME FRIDAY NIGHT INTO
SATURDAY...EVENTUALLY VEERING SOUTHERLY BY LATER SATURDAY. MAY NEED
SOME EXTENSIONS TO ONGOING ADVISORIES...ESPECIALLY ACROSS LAKE
HURON...THROUGH THIS PERIOD.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY UNTIL 9 AM EST FRIDAY FOR MIZ016>019-
021>024-027>030.
LH...SMALL CRAFT ADVISORY UNTIL 4 PM EST FRIDAY FOR LHZ345>349.
LM...SMALL CRAFT ADVISORY UNTIL 4 PM EST FRIDAY FOR LMZ323-341-342-
344-345.
LS...NONE.
&&
$$
UPDATE...LAWRENCE
SYNOPSIS...TJL
SHORT TERM...MSB
LONG TERM...JPB
AVIATION...LAWRENCE
MARINE...MSB/LAWRENCE
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
933 PM CST SAT DEC 1 2012
.UPDATE...
UPDATE ON THE FOG POTENTIAL TONIGHT.
MANY QUESTION STILL EXIST WITH THE FOG TONIGHT...WITH MULTIPLE
SOURCES OF UNCERTAINTY ACROSS THE AREA.
1. SW MN. HERE...DRIER AIR WITH DEWPIONTS 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.
&&
.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.../00Z TAF ISSUANCE/
MAIN AVIATION ISSUE IS CLEARING THIS EVENING IN PORTIONS OF THE
FA...THEN THE ADVANCEMENT OF MORE LOWER CLDS ALONG WITH DENSE FOG
FORMING OVERNIGHT.
WILL KEEP AN EYE ON THE STEADY PROGRESSION OF THE STRATUS LAYER
MOVING EASTWARD ACROSS FAR EASTERN MN THIS EVENING. BASED ON THE SLOWER
PROGRESSION AND THE POSSIBILITY OF HOLDING ONTO THE MVFR CIGS WILL
LEAN TOWARD A SLOWER SOLUTION AT RNH/EAU WHICH WOULD LIKELY BE IN
THE SOUP THRU THE NEXT 18 HRS...OR UNTIL WINDS SHIFT BACK TO THE
SE/S SUNDAY AFTN. ELSEWHERE...AXN WILL LIKELY SEE THE RETURN OF
STRATUS BY 6Z AS MORE IFR/MVFR CIGS MOVE SOUTHWARD ACROSS NW MN.
RWF REMAINS QUESTIONABLE FOR ANY IFR CIG OVER THE NEXT 6 TO 12
HRS...BUT WITH WINDS LIGHT AND VARIABLE...AREAS OF FOG WILL LIKELY
DEVELOP OVERNIGHT. HOW LOW VSBSYS GET WILL DEPEND UPON THE SFC
WINDS AND THE PROGRESSION OF THE STRATUS ACROSS NW MN. ONCE WINDS
SHIFT TO THE S/SE SUNDAY...EXPECT MUCH BETTER CONDS TO DEVELOP.
KMSP...
SLOWER MOVEMENT OF THE STRATUS ACROSS EASTERN MN IS THE MAIN
PROBLEM IN THE SHORT TERM. BASED ON THE LATEST SATELLITE IMAGERY
THE STRATUS SHOULD BEGIN TO MOVE ACROSS THE TWIN CITIES BETWEEN
1-2Z...BUT THIS IS STILL PROBLEMATIC AS WINDS BECOME LIGHTER THIS
EVENING. WILL CONTINUE THE TREND OF CIGS DECREASING AND/OR
BECOMING VFR BY 1Z...WITH VSBYS 6SM BR. AFT 6Z-9Z VSBYS SHOULD
BEGIN TO LOWER ALONG WITH MVFR CIGS DEVELOPING. THIS FORECAST IS
HIGHLY DEPENDENT ON THE MOVEMENT OF THE LOWER CIGS ACROSS NW MN
AND THE ORIENTATION OF THE BOUNDARY LAYER WINDS FORECAST IN THE
NEXT 12 HRS. DUE TO THE POTENTIAL OF FOG TOWARD MORNING...STARTED
WITH A TEMPO PERIOD AFT 10Z WITH VSBYS DROPPING TO 3/4SM BR AND
CIGS OF 300`. LATER SHIFTS CAN UPDATE BASED ON UPSTREAM CONDS.
ONCE WINDS SHIFT BACK TO THE SE/S SUNDAY...EXPECT A MUCH IMPROVE
AVIATION FORECAST.
/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. ..JLT..
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...FREEZING FOG ADVISORY FROM 3 AM TO 9 AM CST SUNDAY FOR BLUE
EARTH-DAKOTA-FARIBAULT-LE SUEUR-MARTIN-RAMSEY-RICE-SCOTT-
WASECA-WASHINGTON.
FREEZING FOG ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM CST SUNDAY
FOR ANOKA-BENTON-BROWN-CARVER-CHIPPEWA-CHISAGO-DOUGLAS-
HENNEPIN-ISANTI-KANABEC-KANDIYOHI-LAC QUI PARLE-MCLEOD-
MEEKER-MILLE LACS-MORRISON-NICOLLET-POPE-REDWOOD-RENVILLE-
SHERBURNE-SIBLEY-STEARNS-STEVENS-SWIFT-TODD-WATONWAN-WRIGHT-
YELLOW MEDICINE.
DENSE FOG ADVISORY FROM 3 AM TO 9 AM CST SUNDAY FOR FREEBORN-
GOODHUE-STEELE.
WI...FREEZING FOG ADVISORY FROM 3 AM TO 9 AM CST SUNDAY FOR BARRON-
POLK-RUSK-ST. CROIX.
DENSE FOG ADVISORY FROM 3 AM TO 9 AM CST SUNDAY FOR CHIPPEWA-
DUNN-EAU CLAIRE-PEPIN-PIERCE.
&&
$$
BORGHOFF/MPG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
355 PM CST FRI NOV 30 2012
.DISCUSSION...
TONIGHT AND SATURDAY...A STNRY FNT WILL LINGER WELL SE OF THE AREA
OVERNIGHT INTO SATURDAY WHILE A STRENGTHENING WMFNT APPROACHES
FROM THE SW. WINDS ARE CURRENTLY UNDERGOING A SHIFT FROM E TO
SE...CONTINUING TO VEER TO S BY DAYBREAK SAT MRNG. CONCENTRATION
OF MOISTURE IN THE LOWER LEVELS BEHIND THE STNRY FNT AND AHEAD OF
THE WMFNT WILL HELP KEEP LOW STRATUS IN PLACE THROUGH AT LEAST
TMRW MRNG. IN ADDITION...AN INCREASE IN DEWPOINTS WILL HELP
PROMOTE FOG DEVELOPMENT...ESPECIALLY OVER CENTRAL-ERN MN INTO WRN
WI. NOT CONFIDENT ON THE INTENSITY OF THE FOG...INCLUDING THE
POTENTIAL FOR DENSE FOG...SO WILL KEEP ITS MENTION IN ALL
GRIDDED/TEXT PRODUCTS AND LET TRENDS DICTATE IF ANYTHING FURTHER
IS NEEDED. THE SHIFTING WINDS ALONG WITH THE SERIES OF FRONTS WILL
MAINTAIN FAIRLY STEADY TEMPS TNGT IN THE LOW-MID 30S. AS THE WMFNT
PUSHES THRU TMRW...STRONG SLY FLOW WILL BRING IN MUCH WARMER AIR
DESPITE LACK OF STRONG INSOLATION. HIGHS WILL REACH THE MID 40S TO
LWR 50S. BY LATE IN THE DAY...A SMALL BUCKLE IN THE H7-H5 FLOW
WITHIN THE INCREASING MOISTURE COLUMN OVER ERN MN-WRN WI MAY BE
ENOUGH TO PRODUCE ISOLD-SCTD RAIN SHOWERS OVER ERN PORTIONS OF THE
WFO MPX CWFA. NOT LOOKING FOR A LOT OF QPF...ONLY A FEW
HUNDREDTHS...BUT HAVE MAINTAINED POPS INTO THE HIGH-END CHC AND
EVEN LOW-END LIKELY RANGE WITH THE WARM FROPA AND A TRAILING SFC
TROUGH.
SATURDAY NIGHT THROUGH TUESDAY...THE WARM AIR WILL RESIDE OVER
THE AREA THRU THE WEEKEND INTO EARLY NEXT WEEK AS ZONAL FLOW TAKES
HOLD...PREVENTING ANY COLD AIR FROM DROPPING DOWN THRU MON. SFC
HIGH PRES WILL MOVE IN ON SUN...BRINGING TO AN END ANY LINGERING
RAIN SHOWERS OVER WRN WI LATE SAT NIGHT. HIGH PRES SHIFTS OFF TO
THE E SUN NIGHT...CREATING A STRONG PRES GRADIENT IN ADVANCE OF A
STRONG COLD FRONT FOR MID-LATE DAY MON. BREEZY CONDITIONS WILL
DEVELOP MON IN ADVANCE OF AND IMMEDIATELY FOLLOWING THE
CDFNT...AND THERE WILL BE A BRIEF SHOT OF SOME RAIN SHOWERS MAINLY
LATE DAY MON INTO MON EVE. SOME OF THE PRECIP MAY MIX WITH SNOW
SHOWERS AS CAA KICKS IN BEHIND THE CDFNT MON NIGHT INTO TUE. THOUGH
CONDITIONS WILL BE IMPROVING TUE...BRISK NW FLOW WILL REDUCE TEMPS
QUITE NOTICEABLY. HIGHS SUN-MON WILL REACH THE MID 40S TO MID
50S...FOLLOWED BY HIGHS IN THE MID 30S TO LWR 40S ON TUE.
TUESDAY NIGHT THROUGH THURSDAY...A BRIEF RESPITE OF HIGH PRES WILL
SHIFT ACRS THE AREA TUE NIGHT THRU WED...THEN A SERIES OF STRONG
SYSTEMS MOVING ONSHORE THE WRN CONUS WILL SHIFT EWD INTO THE
CENTRAL CONUS. ANOTHER STRONG TEMPERATURES SWING IS EXPECTED ALONG
WITH THE POTENTIAL FOR BOTH RAIN AND SNOW. LOTS OF UNCERTAINTY AT
THIS POINT BUT HAVE MAINTAINED CHC POPS THU INTO THU NIGHT.
&&
.AVIATION.../18Z TAF ISSUANCE/
ERLY WINDS ACROSS THE AREA HAS SLOWLY PUSHED STRATUS ACROSS ALL
MPX TERMINALS...WITH THE EDGE OF THE CLOUDS NOW STRETCHING FROM
DUBUQUE OVER TO FAIRMONT...THEN TO TRACY AND WEST TO HURON. WINDS
ARE STARTING TO BECOME MORE SRLY ALONG THE SODAK BORDER...AND AS
THIS HAPPENS...THE RAP AND NAM WOULD INDICATE THAT THESE LOW
CLOUDS SHOULD START RETREATING NORTH. HOWEVER...THE HRRR CONTINUES
TO SLOWLY NUDGE THESE CLOUDS SW DURING THE AFTERNOON AND CERTAINLY
SHOWS NO SIGNS OF CLEANING THEM OUT THIS EVENING. MAKING THE
FORECAST TRICKY FOR TONIGHT...ALL MODELS BASICALLY DRY OUT THE
925-900 MB LAYER /CURRENT CLOUD BEARING LAYER/...BUT KEEP THE ATMO
FROM 925 MB DOWN TO THE SFC NEARLY SATURATED. THIS WOULD MEAN THAT
IF WE DO NOT LOOSE CIGS THIS EVENING...THEN THEY WOULD LIKELY
START TO DESCEND AGAIN TONIGHT UNDER 1K FT...WHICH IS WHAT CURRENT
TAFS GO FOR. SOUNDINGS SHOW PLENTY OF LOW LEVEL MOISTURE FOR FOG
DEVELOPMENT...BUT WITH LOW LEVEL WINDS REMAINING AROUND 10 KTS
THROUGH THE NIGHT...MAIN RESTRICTIONS SHOULD BE THE RESULT OF LOW
STRATUS...WITH VSBYS REMAINING MVFR OR GREATER. AT ANY
RATE...AFTER THE WAY GUIDANCE PERFORMED LAST NIGHT WITH OVER DOING
THE DEVELOPMENT OF LOW STRATUS AND DZ...CONFIDENCE FOR TAFS
TONIGHT IS NOT EXACTLY GREAT.
KMSP...AS WINDS CONTINUE TO SLOWLY VEER THIS AFTERNOON TOWARD 120
AND BEYOND...CLIMATOLOGY WOULD SAY THAT CLOUD HEIGHTS SHOULD
SLOWLY START TO IMPROVE...HENCE HAVE CIGS ABOVE 017 AT 21Z. FOR
TONIGHT...FORECAST SOUNDINGS CERTAINLY SHOW LOW STRATUS STAYING PUT
AND DESCENDING...BUT CLIMATOLOGY WITH WINDS VEERING TOWARD 180
WOULD SAY THERE IS THE POTENTIAL FOR SOME IMPROVEMENT IN CLOUDS.
HOWEVER...GIVEN EXTENT OF CLOUDS TO THE SOUTH AND PRESENT FORECAST
SOUNDINGS...KEPT CLOUDS IN PLACE...WITH CONDITIONS SLOWLY DROPPING TO
IFR THROUGH THE NIGHT. MORE CONFIDENT IN SEEING CIG IMPROVEMENTS
SAT MORNING WITH WINDS CONTINUING TO VEER TOWARD 210 DEGS. BEST
SHOT FOR PRECIP LOOKS TO COME BETWEEN 18Z AND 21Z AS A WEAK
BOUNDARY SLIDES THROUGH...BUT DEEP MOISTURE IS AGAIN LIMITED...SO
LEFT ANY PRECIP MENTION OUT.
/OUTLOOK FOR KMSP/
SUN...MFVR OR LOWER CIGS EARLY. VFR BY AFTERNOON. WINDS S AT 5KTS.
MON...MVFR CIGS. CHANCE OF AFTERNOON -RA. WINDS SSW AT 10G15KTS.
SHIFTING TO THE WNW AT 15G25KTS WITH AFTERNOON FROPA.
TUE...VFR. WINDS NW AT 10G15KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
JPC/MPG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1218 PM CST FRI NOV 30 2012
.UPDATE...
18Z AVIATION DISCUSSION ADDED BELOW.
&&
.PREVIOUS DISCUSSION...
/ISSUED AT 325 AM CST FRI NOV 30 2012/
PRIMARY FORECAST CONCENTRATIONS THIS MORNING ARE THE FREEZING
DRIZZLE POTENTIAL FOR THIS MORNING...PRECIPITATION CHANCES FOR
SATURDAY...AND HIGH TEMPERATURES AND PRECIPITATION CHANCES FOR
MONDAY.
EARLY MORNING WATER VAPOR IMAGERY SHOWS A WEAK SHORTWAVE RIPPLE
TRAVERSING THE AREA...WHILE REGIONAL SURFACE OBS COLLECTIVELY
ILLUSTRATE A WEAK TROUGH FROM NEBRASKA AND IOWA TOWARD LOWER LAKE
MICHIGAN. LOW LEVEL NORTHEASTERLY FLOW HAS ALLOWED THE INFLUX OF
LOW CLOUDS FROM NORTHERN WISCONSIN INTO THE FORECAST AREA TO
COMMENCE. WHILE CEILINGS HAVE REDUCED TO AROUND 1500 FEET ACROSS
WEST CENTRAL WI AND CENTRAL MN COUNTIES /GENERALLY ALONG AND NORTH
OF INTERSTATE 94/...THE DEPTH OF THE MOISTURE IS SEEMINGLY FAIRLY
SHALLOW...AND PROGGED LIFT IS MODEST AT BEST. WILL RETAIN A BRIEF
PERIOD OF FREEZING DRIZZLE AFTER 12Z FROM CENTRAL AND EAST CENTRAL
MN ACROSS WEST CENTRAL WI...BUT ANY ACTIVITY SHOULD BE VERY LIGHT
AND TRANSITION TO THE LIQUID FORM BY LATE MORNING AS SURFACE TEMPS
RISE ABOVE FREEZING.
ALTHOUGH DIURNAL WARMING TODAY WILL BE AT A MINIMUM...THE
RELATIVELY WARM START TO THE DAY WILL SET THE STAGE FOR A MILD
DAY. HIGH TEMPERATURES WILL RANGE FROM THE MID 30S TO LOWER 40S.
MEANWHILE...A SURFACE TROUGH WILL ENTER THE DAKOTAS TODAY...AND
EJECT NORTHEAST TO NORTHWESTERN ONTARIO BY SATURDAY MORNING.
ATTENDANT MID LEVEL ENERGY WILL SPILL INTO THE AREA ON
SATURDAY AND SATURDAY NIGHT...AS THE WEAK TRAILING COLD FRONT MOVES
ACROSS THE AREA. WHILE MOISTURE MAY AGAIN BE LACKING...MODEL
AGREEMENT/CONSISTENCY IS SUFFICIENT TO SUPPORT CHANCE POPS FROM
CENTRAL MN INTO WEST CENTRAL WI...AND LOW LIKELY POPS NEAR
LADYSMITH WHERE MOISTURE IS MORE PROMISING.
HIGH PRESSURE PREVAILS ON SUNDAY IN THE WAKE OF THE TROUGH...WITH
A CONTINUANCE OF THE MILD WEATHER WITH HIGHS IN THE LOWER 40S TO
MID 50S RANGE. THE NEXT TROUGH ARRIVES ON MONDAY...WITH MOISTURE
NOT APPEARING THAT IMPRESSIVE ONCE AGAIN. HAVE RETAINED
SLIGHT/CHANCE POPS FOR MONDAY...BUT BRISK WINDS WILL PROBABLY BE
THE BIGGER HEADLINE. HAVE INCLUDED 15 TO 25 KT WINDS...WITH GUSTS
TO 35 KTS APPEARING POSSIBLE ON MONDAY AND TUESDAY. COULD SEE HIGH
TEMPS APPROACHING RECORD VALUES ON MONDAY PRIOR TO THE
FROPA...WITH 850MB TEMPS PROGGED TO INCREASE TO AROUND +11C.
YET ANOTHER WEAK SYSTEM IS PROGGED TO MOVE ACROSS THE NORTH
CENTRAL CONUS TOWARD THE END OF NEXT WEEK...PER GFS AND ECMWF
MODELS. THIS FEATURE APPEARS SLIGHTLY MORE AMPLIFIED AND
COLDER...SO SNOW HAS BEEN INTRODUCED INTO THE FORECAST FOR THE
THURSDAY-FRIDAY TIME FRAME OF NEXT WEEK.
&&
.AVIATION.../18Z TAF ISSUANCE/
ERLY WINDS ACROSS THE AREA HAS SLOWLY PUSHED STRATUS ACROSS ALL
MPX TERMINALS...WITH THE EDGE OF THE CLOUDS NOW STRETCHING FROM
DUBUQUE OVER TO FAIRMONT...THEN TO TRACY AND WEST TO HURON. WINDS
ARE STARTING TO BECOME MORE SRLY ALONG THE SODAK BORDER...AND AS
THIS HAPPENS...THE RAP AND NAM WOULD INDICATE THAT THESE LOW
CLOUDS SHOULD START RETREATING NORTH. HOWEVER...THE HRRR CONTINUES
TO SLOWLY NUDGE THESE CLOUDS SW DURING THE AFTERNOON AND CERTAINLY
SHOWS NO SIGNS OF CLEANING THEM OUT THIS EVENING. MAKING THE
FORECAST TRICKY FOR TONIGHT...ALL MODELS BASICALLY DRY OUT THE
925-900 MB LAYER /CURRENT CLOUD BEARING LAYER/...BUT KEEP THE ATMO
FROM 925 MB DOWN TO THE SFC NEARLY SATURATED. THIS WOULD MEAN THAT
IF WE DO NOT LOOSE CIGS THIS EVENING...THEN THEY WOULD LIKELY
START TO DESCEND AGAIN TONIGHT UNDER 1K FT...WHICH IS WHAT CURRENT
TAFS GO FOR. SOUNDINGS SHOW PLENTY OF LOW LEVEL MOISTURE FOR FOG
DEVELOPMENT...BUT WITH LOW LEVEL WINDS REMAINING AROUND 10 KTS
THROUGH THE NIGHT...MAIN RESTRICTIONS SHOULD BE THE RESULT OF LOW
STRATUS...WITH VSBYS REMAINING MVFR OR GREATER. AT ANY
RATE...AFTER THE WAY GUIDANCE PERFORMED LAST NIGHT WITH OVER DOING
THE DEVELOPMENT OF LOW STRATUS AND DZ...CONFIDENCE FOR TAFS
TONIGHT IS NOT EXACTLY GREAT.
KMSP...AS WINDS CONTINUE TO SLOWLY VEER THIS AFTERNOON TOWARD 120
AND BEYOND...CLIMATOLOGY WOULD SAY THAT CLOUD HEIGHTS SHOULD
SLOWLY START TO IMPROVE...HENCE HAVE CIGS ABOVE 017 AT 21Z. FOR
TONIGHT...FORECAST SOUNDINGS CERTAINLY SHOW LOW STRATUS STAYING PUT
AND DESCENDING...BUT CLIMATOLOGY WITH WINDS VEERING TOWARD 180
WOULD SAY THERE IS THE POTENTIAL FOR SOME IMPROVEMENT IN CLOUDS.
HOWEVER...GIVEN EXTENT OF CLOUDS TO THE SOUTH AND PRESENT FORECAST
SOUNDINGS...KEPT CLOUDS IN PLACE...WITH CONDITIONS SLOWLY DROPPING TO
IFR THROUGH THE NIGHT. MORE CONFIDENT IN SEEING CIG IMPROVEMENTS
SAT MORNING WITH WINDS CONTINUING TO VEER TOWARD 210 DEGS. BEST
SHOT FOR PRECIP LOOKS TO COME BETWEEN 18Z AND 21Z AS A WEAK
BOUNDARY SLIDES THROUGH...BUT DEEP MOISTURE IS AGAIN LIMITED...SO
LEFT ANY PRECIP MENTION OUT.
/OUTLOOK FOR KMSP/
SUN...MFVR OR LOWER CIGS EARLY. VFR BY AFTERNOON. WINDS S AT 5KTS.
MON...MVFR CIGS. CHANCE OF AFTERNOON -RA. WINDS SSW AT 10G15KTS.
SHIFTING TO THE WNW AT 15G25KTS WITH AFTERNOON FROPA.
TUE...VFR. WINDS NW AT 10G15KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
LS/MPG
AREA FORECAST DISCUSSION
NWS DULUTH MN
1142 PM CST THU NOV 29 2012
.UPDATE...
WE`VE UPDATED GRIDS TO INCREASE POPS ACROSS THE FAR NORTH WHERE
LIGHT SNOW WAS DEVELOPING. KCDD WAS DOWN TO 1.75SM IN SNOW AND SNOW
WAS LOCATED UPSTREAM AT KFGN/KBDE/KRRT. HIGH RES AND MODELS
INDICATE THE SNOW WILL LIFT NORTH LATE TONIGHT.
A FEW BANDS OF SNOW HAVE ALSO DEVELOPED OVER LAKE SUPERIOR AND
WERE MOVING UP THE SHORE. WE STILL EXPECT LAKE EFFECT SNOW TO
INCREASE IN COVERAGE UP THE SHORE OVERNIGHT...AS LOW LEVEL WINDS
VEER.
WE HAVE NOT SEEN ANY PRECIP YET OUTSIDE OF THE LES AND THE SNOW
ACROSS THE FAR NORTH. WE LEFT THE MENTION OF FREEZING DRIZZLE IN
THE FORECAST...ESPECIALLY LATE.
&&
.AVIATION...06Z TAFS
MVFR/IFR CONDITIONS COVERED MOST OF THE NORTHLAND...AND THAT WILL
CONTINUE AS THERE WILL BE PLENTY OF LOW LEVEL MOISTURE PRESENT
THROUGH THE PERIOD. LIGHT SNOW WAS AFFECTING THE BORDER REGION
LATE THIS EVENING...WITH SOME LAKE EFFECT SNOW AS WELL ALONG THE
NORTH SHORE. IFR VSBYS WILL BE POSSIBLE OVERNIGHT AT THE KINL TAF.
SOME FREEZING DRIZZLE WILL ALSO REMAIN A THREAT AS A WEAK
SHORTWAVE MOVES THROUGH THE REGION. THERE HAS NOT BEEN ANY REPORTS
YET...AND IT LOOKS LIKE COVERAGE WILL BE LIMITED. WE LEFT THE
MENTION IN KDLH/KHYR/KBRD/KHIB TAFS AS THERE ARE NOT STRONG ENOUGH
REASONS TO PULL IT YET.
&&
.PREV DISCUSSION... /ISSUED 556 PM CST THU NOV 29 2012/
UPDATE...
VERY LIGHT SNOW/FLURRIES WERE FALLING IN THE DULUTH AREA DUE TO
NORTHEAST WINDS DOWN LAKE SUPERIOR.
WE`VE RECEIVED A COUPLE SHIP REPORTS OF WATER TEMPERATURES OF
5C...AND BOTH THE RUC AND NAM SHOW 850MB TEMPS FROM -12C TO -5C
FROM GRAND PORTAGE TO THE TWIN PORTS. BUFR SOUNDINGS INDICATE
INVERSION LEVELS ARE RATHER LOW. WE INCREASED POPS A BIT
TONIGHT...MAINLY ALONG THE NORTH SHORE...AND BEEFED UP THE MENTION
OF FREEZING DRIZZLE AS WELL.
LOW LEVEL FLOW IS FORECAST TO VEER THROUGH THE EVENING TO MORE
E-SE...SHIFTING THE FOCUS FOR LES TO THE NORTH SHORE FROM THE TWIN
PORTS. WE DON`T EXPECT SIGNIFICANT ACCUMULATION TO OCCUR AROUND
KDLH AS THE LOWER DELTA-T`S AND INVERSION LEVELS ARE NOT THAT
FAVORABLE. THINGS DO COME TOGETHER MORE ALONG THE NORTH
SHORE...ESPECIALLY NORTH AND EAST OF SILVER BAY FROM LATE EVENING
ON. SOME SNOW ACCUMULATION WILL BE POSSIBLE UP THERE...AND WE`LL
HAVE 1-3 INCH AMOUNTS...WITH SOME LOCALIZED HIGHER AMOUNTS. WE`LL
MONITOR THE NORTH SHORE CLOSELY FOR HIGHER SNOW AMOUNTS.
FORECAST SOUNDINGS LOOK FAVORABLE FOR FREEZING DRIZZLE OVER THE
SOUTHERN HALF/TWO THIRDS OF THE CWA OVERNIGHT...THOUGH
PRECIPITATION AMOUNTS DO LOOK TO BE LIMITED. HOWEVER...IT ONLY
TAKES A LITTLE FREEZING PRECIPITATION TO GET SOME SLICK ROADS.
AVIATION...00Z TAFS
IFR AND MVFR CEILINGS COVERED MOST OF THE NORTHLAND THIS
EVENING...WITH SOME VFR CONDITIONS IN THE FAR NORTH/NORTHEAST. WE
EXPECT CEILINGS TO LOWER ALL AREAS OVERNIGHT...WITH MOST
EXPERIENCING IFR CONDITIONS BY 12Z. WAA AND A WEAK SHORTWAVE WILL
COMBINE TO BRING THE THREAT FOR LIGHT PRECIPITATION OVERNIGHT.
FORECAST SOUNDINGS LOOK FAVORABLE FOR FREEZING DRIZZLE AS THERE IS
A DRY LAYER PRESENT AND THE MOIST LAYER IS MOSTLY WARMER THAN
-10C. WE DID ADD FREEZING DRIZZLE TO THE KDLH/KHIB/KHYR TAFS
TONIGHT. FOG WILL DEVELOP OVERNIGHT INTO FRIDAY AS WELL WITH
INCREASING MOISTURE.
PREV DISCUSSION... /ISSUED 256 PM CST THU NOV 29 2012/
SHORT TERM...TONIGHT THROUGH FRIDAY NIGHT
THE MAIN CONCERN FOR THE SHORT TERM PERIOD WILL BE PRECIPITATION
TYPE ISSUES INTO FRIDAY. AREA SOUNDINGS AND BUFKIT PROFILES DEPICT
SOME FREEZING DRIZZLE ESPECIALLY FOR THE SOUTHERN HALF OF THE
FORECAST AREA. ANY FREEZING DRIZZLE THAT FALLS WILL BE VERY LIGHT
AND SPOTTY. ANOTHER CONCERN WILL BE FOR LAKE EFFECT SNOW AS WINDS
WILL BECOME MORE EASTERLY TONIGHT. TEMPERATURE PROFILES FAVOR ALL
SNOW FOR THE NORTH SHORE WHERE SNOW ACCUMULATIONS COULD REACH AROUND
AN INCH TONIGHT. THE LAKE EFFECT SNOW SHOWERS WILL DIMINISH AND SHIFT
INTO THE ARROWHEAD ONCE WINDS BECOME SOUTHEASTERLY EARLY FRIDAY. A
WEAK SHORTWAVE APPROACHING FROM THE WEST WILL CONTINUE TO BRING A
SLIGHT CHANCE OF LIGHT SNOW SHOWERS AND PATCHY FREEZING DRIZZLE OVER
THE NORTHERN HALF OF THE FORECAST AREA THROUGH FRIDAY NIGHT.
TEMPERATURES ON FRIDAY WILL RISE TO THE MIDDLE 30S OVER THE FAR
SOUTHERN PORTIONS OF THE AREA ENDING THE FREEZING DRIZZLE THREAT.
WARM AIR ADVECTION FROM THE SOUTH OVER THE SNOW COVERED GROUND WILL
LEAD TO AREAS OF FOG OVER MOST OF THE FORECAST AREA ON FRIDAY NIGHT.
LONG TERM...SATURDAY THROUGH TUESDAY...
MID LVL RIDGE BREAKS DOWN ALONG PACNW COAST ALLOWING A RAPID INFLUX
OF MILD AIR TO SPREAD INLAND TO NRN CONUS FROM SATURDAY INTO MONDAY.
A WEAK SYSTEM...SFC/ALOFT...WILL PROGRESS FROM THE NRN PLAINS INTO
THE GT LAKES SATURDAY WITH LIGHT PRECIP EXPECTED. MAY SEE SOME
RESIDUAL FZRA/SN OVER INTERIOR OF THE ARROWHEAD SATURDAY AS
RETREATING COLD DOME IS TOPPED BY WARM AIR ADVECTION. WEAK COLD
FRONT MAY ALLOW BRIEF TRANSITION TO RA/SN OVER NRN TIER OF MN ZONES
EARLY SUNDAY. NEXT SYSTEM HAS MUCH STRONGER DYNAMICS ALOFT AND WILL
INTENSIFY AS IT MOVES FROM NODAK INTO WRN ONTARIO MONDAY. SIGNIFICANT
PUSH OF WARM AIR WILL KEEP PTYPE IN THE LIQUID FORM MONDAY BEFORE
CHANGING TO SNOW MONDAY NIGHT OVER MN ZONES. ALTHOUGH THERE WILL BE
SIGNIFICANT COLD AIR ADVECTION BEHIND THE SYSTEM TUESDAY...THE
PROGRESSIVE NATURE OF THE FLOW ALOFT APPEARS TO MAKE A CASE FOR A
RETURN TO ANOMALOUS WARMTH FOR LATE IN THE WEEK.
&&
.POINT TEMPS/POPS...
DLH 21 32 29 39 / 40 30 20 50
INL 12 29 26 37 / 60 30 20 40
BRD 23 33 29 41 / 20 20 10 40
HYR 22 33 31 43 / 20 20 10 50
ASX 23 32 30 43 / 30 20 20 40
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 6 PM CST FRIDAY FOR LSZ121-140>148.
&&
$$
SHORT TERM...MELDE
LONG TERM....CANNON
AVIATION...MELDE
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1201 PM CST FRI NOV 30 2012
.SHORT TERM...
ISSUED AT 350 AM CST FRI NOV 30 2012
(TODAY)
UNSEASONABLY MILD LATE AUTUMN NIGHT SHOULD BE A LEAD-IN TO AN
UNSEASONABLY WARM LATE NOVEMBER DAY FOR THE CWA...AND CLOUDS WILL BE
THE DETERIMINING FACTOR ON HOW WARM WE WILL GET THIS AFTERNOON.
MODELS ARE FORECASTING THE INCREASE IN LOW LEVEL RH TO BEGIN
TODAY...AND INDEED THE LOW CLOUD SATELLITE ENHANCEMENT HAS INDICATED
SOME CLOUDS FORMING OVER E OK AND W CENTRAL/NW AR OVER THE PAST FEW
HOURS...WITH A FEW CLOUDS ALSO JUST BEGINNING TO SHOW UP SE OF A
VIH-FAM LINE. HOWEVER... BELIEVE THIS INITIAL SURGE WILL BE FAIRLY
SHALLOW AND MAY HAVE A DIFFICULT TIME MAINTAINING A PERSISTENT CLOUD
DECK. RAP DATA SUGGESTS THAT THE BEST LOW LEVEL MOISTURE RETURN
THROUGH TODAY WILL REMAIN TO OUR S...BOTTLED UP BY THE ARKANSAS
PORTION OF THE OZARK PLATEAU/BOSTON MOUNTAINS. BASED ON THE THINKING
THAT THERE SHOULD BE A FAIR AMOUNT OF SUNSHINE TODAY HAVE ONCE AGAIN
TRENDED TO THE WARMER MET NUMBERS...WITH HIGHS RANGING FROM AROUND
60 IN FAR N/E COUNTIES OF THE CWA TO THE MIDDLE 60S ALONG AND S OF
THE I-70 CORRIDOR IN MO.
TRUETT
&&
.LONG TERM...
ISSUED AT 350 AM CST FRI NOV 30 2012
(TONIGHT THROUGH SUNDAY NIGHT)
A LOT TO DEAL WITH IN THE SHORT TERM...AS FORECAST AREA TO SEE WELL
ABOVE NORMAL TEMPERATURES THROUGH THE PERIOD...DESPITE A BIT MORE
CLOUDS OVER THE REGION THROUGH THE WEEKEND.
FOR TONIGHT...WEAK WARM FRONT TO LIFT NORTH OF FORECAST AREA...SO
ANY PATCHY FOG THAT MAY FORM OVER NORTHERN PORTIONS OF FORECAST
EARLY ON...WILL IMPROVE AS WINDS PICKUP FROM THE SOUTH.
OTHERWISE...LOWS WILL ONLY BE IN THE 40S.
THEN ON SATURDAY LOW LEVEL MOISTURE WILL CONTINUE TO BE ON THE
INCREASE AHEAD OF COLD FRONT THAT WILL SLIDE THROUGH AREA SATURDAY
NIGHT...BEFORE WEAKENING/WASHING OUT ON SUNDAY. SOME CONCERN ABOUT
STRATUS ADVECTING NORTH INTO SOUTHERN PORTIONS OF FORECAST AREA
SATURDAY MORNING AHEAD OF SYSTEM...BUT BUFKIT SOUNDINGS HAVE BRIEF
LOW CIGS WITH STRATUS THEN LIFT BY MID MORNING. SO FOR NOW HAVE NOT
ADDED MENTION OF DRIZZLE IN THIS AREA. OTHERWISE...WILL SEE SOME
LIGHT RAIN DEVELOP OVER NORTHERN PORTIONS OF FORECAST AREA AHEAD OF
COLD FRONT SATURDAY AFTERNOON. AMOUNTS WITH THIS SYSTEM WILL BE
RATHER LIGHT...SO JUST WENT WITH LOW CHANCE POPS AND LIGHT RAIN. AS
FOR TEMPS...WITH MORE CLOUDS FORECAST OVER THE REGION...LOWERED HIGH
TEMPS A FEW DEGREES...INTO THE LOW TO MID 60S.
BETTER CHANCES OF LIGHT RAIN SATURDAY NIGHT...BUT STILL NOT A LOT OF
QPF WITH FRONTAL BOUNDARY...SO KEPT LOW CHANCE POPS FOR AREAS ALONG
AND NORTH OF A STEELVILLE MO TO SPARTA IL LINE. ANOTHER MILD NIGHT
IN STORE WITH LOWS ONLY IN THE LOW TO MID 50S.
ON SUNDAY THE FRONTAL BOUNDARY WILL WASHOUT ALONG I-44 CORRIDOR...SO
SOME LINGERING LIGHT RAIN POSSIBLE ALONG AND SOUTH OF THIS AREA
DURING THE DAY...WHICH COULD LINGER INTO SUNDAY NIGHT...BUT
CONFIDENCE IS LOW...SO KEPT MENTION OUT FOR NOW. AS FOR
TEMPS...CLOUDS TO THIN OUT FOR NORTHERN PORTIONS OF FORECAST AREA
AND WINDS TO PICKUP FROM THE SOUTHWEST. SO WILL SEE NEAR RECORD
HIGHS WITH TEMPS IN THE 65 TO 70 DEGREE RANGE. MILD TEMPS TO PERSIST
SUNDAY NIGHT...WILL LOWS IN THE MID TO UPPER 50S.
(MONDAY THROUGH THURSDAY)
BY MONDAY...A MORE VIGOROUS SYSTEM TO APPROACH THE REGION WITH A
COLD FRONT SLIDING THROUGH DURING THE AFTERNOON AND EVENING HOURS.
SOME DECENT INSTABILITY...LIFT AND LOW LEVEL MOISTURE...SO SHOULD
SEE SHOWERS AND SOME THUNDERSTORMS. HIGHS ON MONDAY WILL REMAIN WELL
ABOVE NORMAL IN THE UPPER 60S TO LOW 70S...NEAR RECORD HIGHS FOR A
NUMBER OF LOCATIONS. LOWS MONDAY NIGHT WILL BE IN THE LOW 40S FAR
NORTH TO THE LOW 50S FAR SOUTHEAST.
BY TUESDAY...SHOWERS TO TAPER OFF AND COLDER AIR TO FILTER IN.
HOWEVER...NOT A LOT OF CAA WITH SYSTEM...SO TEMPS WILL STILL BE A
BIT ABOVE NORMAL...IN THE LOW 50S NORTH TO THE UPPER 50S SOUTH.
BEYOND THAT...SURFACE RIDGE TO BUILD IN WITH NEAR NORMAL TEMPS FOR
THE REST OF THE FORECAST PERIOD.
BYRD
&&
.AVIATION...
ISSUED AT 1138 AM CST FRI NOV 30 2012
PRIMARY CONCERN FOR THIS FORECAST CYCLE WILL BE STRATUS OVERSPREADING
MUCH OF THE AREA LATE TONIGHT. AM ALSO WATCHING A DEVELOPING 5000FT
DECK MOVING NORTH-NORTHEAST OVER THE OZARKS WHICH MAY ALSO IMPACT
THE AREA LATE THIS AFTERNOON. HOWEVER...NOT EXPECTING ANY CLOUDS
BELOW VFR CONDITIONS UNTIL TONIGHT. CURRENT INDICATIONS ARE THAT
STRATUS WILL MOVE FROM THE SOUTHEAST PLAINS TONIGHT AND SPREAD
NORTHEAST THROUGH MISSOURI. FEEL PRETTY CONFIDENT THERE WILL BE
CLOUDS...BUT LESS CONFIDENT IN HEIGHTS THO IFR DOES APPEAR LIKELY
OVER MUCH OF CENTRAL AND NORTHEAST MO BEFORE 12Z SATURDAY. CIGS
SHOULD BE HIGHER FURTHER EAST...BUT AS MENTIONED BEFORE AM NOT
SURE HOW MUCH HIGHER...AND WHERE THE TRANSITION FROM IFR TO MVFR
WILL BE.
SPECIFICS FOR KSTL...
PRIMARY CONCERN AT LAMBERT WILL BE DEVELOPING MVFR...POTENTIALLY
IFR CIGS LATE TONIGHT/EARLY SATURDAY MORNING. CURRENT INDICATIONS
ARE THAT CIGS BELOW 2000FT WILL STAY WEST OF THE TERMINAL...BUT
THERE IS A CHANCE THAT LOWER CONDITIONS COULD AFFECT LAMBERT. FOR
NOW IT LOOKS LIKE THE PROBABILITY OF LOW MVFR/IFR IS LESS THAN 50
PERCENT. WILL LET FOLLOWING SHIFTS TAKE ANOTHER LOOK AND
REEVALUATE AS NEEDED. CIGS SHOULD HANG AROUND FOR MOST IF NOT ALL
DAY SATURDAY.
CARNEY
&&
.CLIMATE...
ISSUED AT 504 PM CST WED NOV 28 2012
ABOVE NORMAL TEMPERATURES ARE FORECAST THIS WEEKEND. HERE ARE THE
RECORD HIGH AND HIGH MINIMUM TEMPERATURES FOR THE FIRST THREE DAYS
OF DECEMBER FOR THE CITIES OF ST. LOUIS...COLUMBIA...AND QUINCY.
RECORD HIGH TEMPERATURES...
ST. LOUIS COLUMBIA QUINCY
SATURDAY 12/1 73F (1970) 68F (1982) 67F (1913)
SUNDAY 12/2 74F (1982) 72F (1917) 67F (1982)
MONDAY 12/3 76F (1970) 72F (1998) 71F (1970)
RECORD HIGH MINIMUM TEMPERATURES...
ST. LOUIS COLUMBIA QUINCY
SATURDAY 12/1 53F (1980) 53F (1921) 52 (1913)
SUNDAY 12/2 63F (1982) 59F (1982) 59 (1982)
MONDAY 12/3 62F (1998) 58F (1998) 59 (1998)
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
557 AM CST FRI NOV 30 2012
.SHORT TERM...
ISSUED AT 350 AM CST FRI NOV 30 2012
(TODAY)
UNSEASONABLY MILD LATE AUTUMN NIGHT SHOULD BE A LEAD-IN TO AN
UNSEASONABLY WARM LATE NOVEMBER DAY FOR THE CWA...AND CLOUDS WILL BE
THE DETERIMINING FACTOR ON HOW WARM WE WILL GET THIS AFTERNOON.
MODELS ARE FORECASTING THE INCREASE IN LOW LEVEL RH TO BEGIN
TODAY...AND INDEED THE LOW CLOUD SATELLITE ENHANCEMENT HAS INDICATED
SOME CLOUDS FORMING OVER E OK AND W CENTRAL/NW AR OVER THE PAST FEW
HOURS...WITH A FEW CLOUDS ALSO JUST BEGINNING TO SHOW UP SE OF A
VIH-FAM LINE. HOWEVER... BELIEVE THIS INITIAL SURGE WILL BE FAIRLY
SHALLOW AND MAY HAVE A DIFFICULT TIME MAINTAINING A PERSISTENT CLOUD
DECK. RAP DATA SUGGESTS THAT THE BEST LOW LEVEL MOISTURE RETURN
THROUGH TODAY WILL REMAIN TO OUR S...BOTTLED UP BY THE ARKANSAS
PORTION OF THE OZARK PLATEAU/BOSTON MOUNTAINS. BASED ON THE THINKING
THAT THERE SHOULD BE A FAIR AMOUNT OF SUNSHINE TODAY HAVE ONCE AGAIN
TRENDED TO THE WARMER MET NUMBERS...WITH HIGHS RANGING FROM AROUND
60 IN FAR N/E COUNTIES OF THE CWA TO THE MIDDLE 60S ALONG AND S OF
THE I-70 CORRIDOR IN MO.
TRUETT
&&
.LONG TERM...
ISSUED AT 350 AM CST FRI NOV 30 2012
(TONIGHT THROUGH SUNDAY NIGHT)
A LOT TO DEAL WITH IN THE SHORT TERM...AS FORECAST AREA TO SEE WELL
ABOVE NORMAL TEMPERATURES THROUGH THE PERIOD...DESPITE A BIT MORE
CLOUDS OVER THE REGION THROUGH THE WEEKEND.
FOR TONIGHT...WEAK WARM FRONT TO LIFT NORTH OF FORECAST AREA...SO
ANY PATCHY FOG THAT MAY FORM OVER NORTHERN PORTIONS OF FORECAST
EARLY ON...WILL IMPROVE AS WINDS PICKUP FROM THE SOUTH.
OTHERWISE...LOWS WILL ONLY BE IN THE 40S.
THEN ON SATURDAY LOW LEVEL MOISTURE WILL CONTINUE TO BE ON THE
INCREASE AHEAD OF COLD FRONT THAT WILL SLIDE THROUGH AREA SATURDAY
NIGHT...BEFORE WEAKENING/WASHING OUT ON SUNDAY. SOME CONCERN ABOUT
STRATUS ADVECTING NORTH INTO SOUTHERN PORTIONS OF FORECAST AREA
SATURDAY MORNING AHEAD OF SYSTEM...BUT BUFKIT SOUNDINGS HAVE BRIEF
LOW CIGS WITH STRATUS THEN LIFT BY MID MORNING. SO FOR NOW HAVE NOT
ADDED MENTION OF DRIZZLE IN THIS AREA. OTHERWISE...WILL SEE SOME
LIGHT RAIN DEVELOP OVER NORTHERN PORTIONS OF FORECAST AREA AHEAD OF
COLD FRONT SATURDAY AFTERNOON. AMOUNTS WITH THIS SYSTEM WILL BE
RATHER LIGHT...SO JUST WENT WITH LOW CHANCE POPS AND LIGHT RAIN. AS
FOR TEMPS...WITH MORE CLOUDS FORECAST OVER THE REGION...LOWERED HIGH
TEMPS A FEW DEGREES...INTO THE LOW TO MID 60S.
BETTER CHANCES OF LIGHT RAIN SATURDAY NIGHT...BUT STILL NOT A LOT OF
QPF WITH FRONTAL BOUNDARY...SO KEPT LOW CHANCE POPS FOR AREAS ALONG
AND NORTH OF A STEELVILLE MO TO SPARTA IL LINE. ANOTHER MILD NIGHT
IN STORE WITH LOWS ONLY IN THE LOW TO MID 50S.
ON SUNDAY THE FRONTAL BOUNDARY WILL WASHOUT ALONG I-44 CORRIDOR...SO
SOME LINGERING LIGHT RAIN POSSIBLE ALONG AND SOUTH OF THIS AREA
DURING THE DAY...WHICH COULD LINGER INTO SUNDAY NIGHT...BUT
CONFIDENCE IS LOW...SO KEPT MENTION OUT FOR NOW. AS FOR
TEMPS...CLOUDS TO THIN OUT FOR NORTHERN PORTIONS OF FORECAST AREA
AND WINDS TO PICKUP FROM THE SOUTHWEST. SO WILL SEE NEAR RECORD
HIGHS WITH TEMPS IN THE 65 TO 70 DEGREE RANGE. MILD TEMPS TO PERSIST
SUNDAY NIGHT...WILL LOWS IN THE MID TO UPPER 50S.
(MONDAY THROUGH THURSDAY)
BY MONDAY...A MORE VIGOROUS SYSTEM TO APPROACH THE REGION WITH A
COLD FRONT SLIDING THROUGH DURING THE AFTERNOON AND EVENING HOURS.
SOME DECENT INSTABILITY...LIFT AND LOW LEVEL MOISTURE...SO SHOULD
SEE SHOWERS AND SOME THUNDERSTORMS. HIGHS ON MONDAY WILL REMAIN WELL
ABOVE NORMAL IN THE UPPER 60S TO LOW 70S...NEAR RECORD HIGHS FOR A
NUMBER OF LOCATIONS. LOWS MONDAY NIGHT WILL BE IN THE LOW 40S FAR
NORTH TO THE LOW 50S FAR SOUTHEAST.
BY TUESDAY...SHOWERS TO TAPER OFF AND COLDER AIR TO FILTER IN.
HOWEVER...NOT A LOT OF CAA WITH SYSTEM...SO TEMPS WILL STILL BE A
BIT ABOVE NORMAL...IN THE LOW 50S NORTH TO THE UPPER 50S SOUTH.
BEYOND THAT...SURFACE RIDGE TO BUILD IN WITH NEAR NORMAL TEMPS FOR
THE REST OF THE FORECAST PERIOD.
BYRD
&&
.AVIATION...
ISSUED AT 538 AM CST FRI NOV 30 2012
LOW LEVEL JET APPEARS TO BE IN THE PROCESS OF BACKING OFF A BIT
ACCORDING TO THE LATEST REGIONAL VWPS AND RAP DATA...HOWEVER
SPEEDS ARE STILL CLOSE ENOUGH THAT WE WILL CARRY WIND SHEAR
THROUGH 14Z.
OTHERWISE...VFR CONDITIONS WILL CONTINUE ACROSS THE AREA
TODAY...BUT WITH TIME PERSISTENT S LOW LEVEL FLOW WILL BE
MOISTENING THE LOWER LEVELS OF THE AMS CAUSING A DETERIORATION OF
AVIATION WEATHER CONDITIONS. LOW CLOUD SATELLITE LOOP ALREADY
INDICATES LOTS OF STRATUS FORMING AND ADVECTING NE FROM W AR TO E
TX...BUT IT SURE LOOKS LIKE THE NWD PUSH HAS BEEN BLOCKED BY THE
OZARKS PLATEAU...AND IF 00/06Z MODELS ARE TO BE BELIEVED LOWER
LEVEL MOISTURE SHOULD NOT ARRIVE IN OUR AREA UNTIL LATER
TONIGHT...AFTER 06Z. UNFORTUNATELY...SHORT RANGE MODELS VARY
CONSIDERABLY ON WHEN AND HOW THIS LOW LEVEL MOISTURE WILL COME
INTO THE AREA...AS FOG AND/OR STRATUS. FOR NOW HAVE ATTEMPTED TO
INDICATE THESE DETERIORATING CONDITIONS WITH VSBYS/CIGS DROPPING
IN MVFR CAT IN THE 09-12Z TIME FRAME. THIS DOVETAILS WITH THE SREF
CIG/VSBYS PROBABILITY PROGS WHICH SUGGEST LOWERING CONDITIONS
TOWARDS THE END OF THIS TAF FORECAST PERIOD.
SPECIFICS FOR KSTL...LOW LEVEL WIND SHEAR THREAT WILL CONTINUE FOR
SEVERAL MORE HOURS...BUT ALL MODELS AGREE 1KFT WINDS SHOULD BE
DROPPING INTO THE 25-30KT RANGE BY 14Z.
MODEL CONSENSUS SUGGESTS VFR CONDITIONS WILL CONTINUE OVER THE
AREA TODAY AND INTO THIS EVENING...WITH ONLY A FEW HIGH LEVEL
CLOUDS TODAY AND SW SURFACE WINDS AOB 10 KTS. AFOREMENTIONED
LOWERING OF CIGS/VSBYS SHOULD TAKE PLACE AFTER 06Z TONIGHT.
TRUETT
&&
.CLIMATE...
ISSUED AT 504 PM CST WED NOV 28 2012
ABOVE NORMAL TEMPERATURES ARE FORECAST THIS WEEKEND. HERE ARE THE
RECORD HIGH AND HIGH MINIMUM TEMPERATURES FOR THE FIRST THREE DAYS
OF DECEMBER FOR THE CITIES OF ST. LOUIS...COLUMBIA...AND QUINCY.
RECORD HIGH TEMPERATURES...
ST. LOUIS COLUMBIA QUINCY
SATURDAY 12/1 73F (1970) 68F (1982) 67F (1913)
SUNDAY 12/2 74F (1982) 72F (1917) 67F (1982)
MONDAY 12/3 76F (1970) 72F (1998) 71F (1970)
RECORD HIGH MINIMUM TEMPERATURES...
ST. LOUIS COLUMBIA QUINCY
SATURDAY 12/1 53F (1980) 53F (1921) 52 (1913)
SUNDAY 12/2 63F (1982) 59F (1982) 59 (1982)
MONDAY 12/3 62F (1998) 58F (1998) 59 (1998)
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
351 AM CST FRI NOV 30 2012
.SHORT TERM...
ISSUED AT 350 AM CST FRI NOV 30 2012
(TODAY)
UNSEASONABLY MILD LATE AUTUMN NIGHT SHOULD BE A LEAD-IN TO AN
UNSEASONABLY WARM LATE NOVEMBER DAY FOR THE CWA...AND CLOUDS WILL BE
THE DETERIMINING FACTOR ON HOW WARM WE WILL GET THIS AFTERNOON.
MODELS ARE FORECASTING THE INCREASE IN LOW LEVEL RH TO BEGIN
TODAY...AND INDEED THE LOW CLOUD SATELLITE ENHANCEMENT HAS INDICATED
SOME CLOUDS FORMING OVER E OK AND W CENTRAL/NW AR OVER THE PAST FEW
HOURS...WITH A FEW CLOUDS ALSO JUST BEGINNING TO SHOW UP SE OF A
VIH-FAM LINE. HOWEVER... BELIEVE THIS INITIAL SURGE WILL BE FAIRLY
SHALLOW AND MAY HAVE A DIFFICULT TIME MAINTAINING A PERSISTENT CLOUD
DECK. RAP DATA SUGGESTS THAT THE BEST LOW LEVEL MOISTURE RETURN
THROUGH TODAY WILL REMAIN TO OUR S...BOTTLED UP BY THE ARKANSAS
PORTION OF THE OZARK PLATEAU/BOSTON MOUNTAINS. BASED ON THE THINKING
THAT THERE SHOULD BE A FAIR AMOUNT OF SUNSHINE TODAY HAVE ONCE AGAIN
TRENDED TO THE WARMER MET NUMBERS...WITH HIGHS RANGING FROM AROUND
60 IN FAR N/E COUNTIES OF THE CWA TO THE MIDDLE 60S ALONG AND S OF
THE I-70 CORRIDOR IN MO.
TRUETT
&&
.LONG TERM...
ISSUED AT 350 AM CST FRI NOV 30 2012
(TONIGHT THROUGH SUNDAY NIGHT)
A LOT TO DEAL WITH IN THE SHORT TERM...AS FORECAST AREA TO SEE WELL
ABOVE NORMAL TEMPERATURES THROUGH THE PERIOD...DESPITE A BIT MORE
CLOUDS OVER THE REGION THROUGH THE WEEKEND.
FOR TONIGHT...WEAK WARM FRONT TO LIFT NORTH OF FORECAST AREA...SO
ANY PATCHY FOG THAT MAY FORM OVER NORTHERN PORTIONS OF FORECAST
EARLY ON...WILL IMPROVE AS WINDS PICKUP FROM THE SOUTH.
OTHERWISE...LOWS WILL ONLY BE IN THE 40S.
THEN ON SATURDAY LOW LEVEL MOISTURE WILL CONTINUE TO BE ON THE
INCREASE AHEAD OF COLD FRONT THAT WILL SLIDE THROUGH AREA SATURDAY
NIGHT...BEFORE WEAKENING/WASHING OUT ON SUNDAY. SOME CONCERN ABOUT
STRATUS ADVECTING NORTH INTO SOUTHERN PORTIONS OF FORECAST AREA
SATURDAY MORNING AHEAD OF SYSTEM...BUT BUFKIT SOUNDINGS HAVE BRIEF
LOW CIGS WITH STRATUS THEN LIFT BY MID MORNING. SO FOR NOW HAVE NOT
ADDED MENTION OF DRIZZLE IN THIS AREA. OTHERWISE...WILL SEE SOME
LIGHT RAIN DEVELOP OVER NORTHERN PORTIONS OF FORECAST AREA AHEAD OF
COLD FRONT SATURDAY AFTERNOON. AMOUNTS WITH THIS SYSTEM WILL BE
RATHER LIGHT...SO JUST WENT WITH LOW CHANCE POPS AND LIGHT RAIN. AS
FOR TEMPS...WITH MORE CLOUDS FORECAST OVER THE REGION...LOWERED HIGH
TEMPS A FEW DEGREES...INTO THE LOW TO MID 60S.
BETTER CHANCES OF LIGHT RAIN SATURDAY NIGHT...BUT STILL NOT A LOT OF
QPF WITH FRONTAL BOUNDARY...SO KEPT LOW CHANCE POPS FOR AREAS ALONG
AND NORTH OF A STEELVILLE MO TO SPARTA IL LINE. ANOTHER MILD NIGHT
IN STORE WITH LOWS ONLY IN THE LOW TO MID 50S.
ON SUNDAY THE FRONTAL BOUNDARY WILL WASHOUT ALONG I-44 CORRIDOR...SO
SOME LINGERING LIGHT RAIN POSSIBLE ALONG AND SOUTH OF THIS AREA
DURING THE DAY...WHICH COULD LINGER INTO SUNDAY NIGHT...BUT
CONFIDENCE IS LOW...SO KEPT MENTION OUT FOR NOW. AS FOR
TEMPS...CLOUDS TO THIN OUT FOR NORTHERN PORTIONS OF FORECAST AREA
AND WINDS TO PICKUP FROM THE SOUTHWEST. SO WILL SEE NEAR RECORD
HIGHS WITH TEMPS IN THE 65 TO 70 DEGREE RANGE. MILD TEMPS TO PERSIST
SUNDAY NIGHT...WILL LOWS IN THE MID TO UPPER 50S.
(MONDAY THROUGH THURSDAY)
BY MONDAY...A MORE VIGOROUS SYSTEM TO APPROACH THE REGION WITH A
COLD FRONT SLIDING THROUGH DURING THE AFTERNOON AND EVENING HOURS.
SOME DECENT INSTABILITY...LIFT AND LOW LEVEL MOISTURE...SO SHOULD
SEE SHOWERS AND SOME THUNDERSTORMS. HIGHS ON MONDAY WILL REMAIN WELL
ABOVE NORMAL IN THE UPPER 60S TO LOW 70S...NEAR RECORD HIGHS FOR A
NUMBER OF LOCATIONS. LOWS MONDAY NIGHT WILL BE IN THE LOW 40S FAR
NORTH TO THE LOW 50S FAR SOUTHEAST.
BY TUESDAY...SHOWERS TO TAPER OFF AND COLDER AIR TO FILTER IN.
HOWEVER...NOT A LOT OF CAA WITH SYSTEM...SO TEMPS WILL STILL BE A
BIT ABOVE NORMAL...IN THE LOW 50S NORTH TO THE UPPER 50S SOUTH.
BEYOND THAT...SURFACE RIDGE TO BUILD IN WITH NEAR NORMAL TEMPS FOR
THE REST OF THE FORECAST PERIOD.
BYRD
&&
.AVIATION...
ISSUED AT 1107 PM CST THU NOV 29 2012
WARM FRONT EXTENDS EAST FROM A WEAK AREA OF LOW PRESSURE IN
EASTERN NEBRASKA THROUGH SOUTHERN IOWA AND INTO CENTRAL ILLINOIS.
AREA REMAINS IN WARM SECTOR WITH SOUTHERLY WINDS OF 5 TO 10KTS.
CLOUD COVER IS LIMITED TO AREAS OF CIRRUS. LOW LEVEL WIND SHEAR
CONTINUES AS WINDS RAPIDLY INCREASE TO 45KTS AT 1500FT. MODELS
DEPICT WIND DECREASING TOMORROW MORNING AS SYSTEM MOVES NORTH OF
THE AREA AND PRESSURE GRADIENT RELAXES. STEADY SOUTHERLY FLOW WILL
EVENTUALLY LEAD TO MOISTURE...CURRENTLY IN SOUTHERN
TEXAS...ADVECTING NORTH/NORTHEAST INTO THE REGION FRIDAY EVENING
AND INTO THE OVERNIGHT HOURS.
SPECIFICS FOR KSTL...
VFR CONDITIONS WILL CONTINUE. LLWS EXPECTED THROUGH FRIDAY MORNING
GIVEN 45KT SOUTHWEST WIND AT 1500FT. CLOUD COVER AROUND 5KFT WILL
BUILD ACROSS THE TERMINAL LATE FRIDAY EVENING OR EARLY SATURDAY
MORNING.
CVKING
&&
.CLIMATE...
ISSUED AT 504 PM CST WED NOV 28 2012
ABOVE NORMAL TEMPERATURES ARE FORECAST THIS WEEKEND. HERE ARE THE
RECORD HIGH AND HIGH MINIMUM TEMPERATURES FOR THE FIRST THREE DAYS
OF DECEMBER FOR THE CITIES OF ST. LOUIS...COLUMBIA...AND QUINCY.
RECORD HIGH TEMPERATURES...
ST. LOUIS COLUMBIA QUINCY
SATURDAY 12/1 73F (1970) 68F (1982) 67F (1913)
SUNDAY 12/2 74F (1982) 72F (1917) 67F (1982)
MONDAY 12/3 76F (1970) 72F (1998) 71F (1970)
RECORD HIGH MINIMUM TEMPERATURES...
ST. LOUIS COLUMBIA QUINCY
SATURDAY 12/1 53F (1980) 53F (1921) 52 (1913)
SUNDAY 12/2 63F (1982) 59F (1982) 59 (1982)
MONDAY 12/3 62F (1998) 58F (1998) 59 (1998)
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1147 PM CST THU NOV 29 2012
.UPDATE...
.AVIATION...
A CLOSER LOOK AT THE LIFR CIGS ACROSS SD AND RAP MODEL DATA
SUGGESTS THESE CIGS COULD BACK INTO KONL AND PERHAPS APPROACH
KVTN FOR A FEW HOURS EARLY THIS MORNING. ITS TOO CLOSE TO CALL
ATTM BUT THIS AREA WILL BE CLOSELY MONITORED OVERNIGHT AS
SATELLITE INDICATES A MORE SOUTHERLY PROGRESSION DEVELOPING.
&&
.PREV DISCUSSION... /ISSUED 1126 PM CST THU NOV 29 2012/
UPDATE...
AVIATION...
VFR IS EXPECTED ALL AREAS OVERNIGHT THROUGH FRIDAY EVENING.
AN AREA OF LIFR CIGS ALONG THE MISSOURI RIVER IN SD WILL MOVE
SOUTHEAST OVERNIGHT SQUIRTING THE NEB BORDER. OTHERWISE SCT-BKN
HIGH LEVEL CLOUDINESS WILL CONTINUE THROUGH FRIDAY EVENING.
PREV DISCUSSION... /ISSUED 500 PM CST THU NOV 29 2012/
UPDATE...
AVIATION...
VFR IS EXPECTED ALL AREAS OVERNIGHT THROUGH FRIDAY.
AN ARCTIC FRONT ACROSS CNTL SD THIS EVENING WILL DROP SOUTH AND
INTO NCNTL NEB OVERNIGHT. THE FRONT IS NOT EXPECTED TO PRODUCE ANY FLIGHT
LIMITATIONS AT THIS TIME. THE RAP MODEL...ETAL SUGGEST STRATUS
WILL FROM ALONG AND NORTH OF THE MISSOURI RIVER...EAST OF THE FCST
AREA.
OTHERWISE SCT-BKN HIGH LEVEL CLOUDINESS WILL CONTINUE THROUGH
FRIDAY.
PREV DISCUSSION... /ISSUED 305 PM CST THU NOV 29 2012/
SYNOPSIS...
12Z H5 HAND ANALYSIS FROM THIS MORNING WAS INDICATING BROAD ZONAL
FLOW EXTENDING ACROSS THE CONUS. LOW PRESSURE WAS PRESENT ACROSS
NORTH CENTRAL CANADA...NRN QUEBEC...AND OFF THE COAST OF BRITISH
COLUMBIA. FURTHER SOUTH ACROSS THE CONUS...STRONG MID AND UPPER
LEVEL FLOW...HAS SPREAD ABUNDANT MID AND HIGH LEVEL CLOUDINESS
ACROSS THE WESTERN THIRD OF THE CONUS TDY. SCATTERED TO BROKEN UPPER
LEVEL CLOUDINESS WHICH WAS PRESENT ACROSS CENTRAL AND NORTHERN
NEBRASKA EARLIER THIS MORNING...AND HAS SHIFTED EAST BY MIDDAY.
UNDER SUNNY SKIES...TEMPERATURES AS OF 2 PM CST...RANGED FROM 46 AT
AINSWORTH...TO 70 AT IMPERIAL.
DISCUSSION...
SHORT RANGE...TONIGHT THROUGH SUNDAY NIGHT...FORECASTING CHALLENGE
WILL BE TEMPERATURES AND THE IMPACT OF CLOUD COVER AND SNOW COVER ON
THEM.
FOR TONIGHT...A WEAK DISTURBANCE WILL TRACK ACROSS THE
DAKOTAS...BACKING A WEAK COOL FRONT INTO NORTHERN NEBRASKA TONIGHT.
THE SRN SURGE OF THE FRONT IS EXPECTED TO REACH THE CENTRAL FORECAST
AREA OVERNIGHT...LIFTING NORTH AS A WARM FRONT ON FRIDAY. LOWS
TONIGHT WILL BE COOLEST IN THE PLATTE RIVER VALLEY WITH LIGHT
WESTERLY WINDS...AND ACROSS THE SNOWFIELD IN THE NRN CWA...WHICH
WILL ENCOMPASS NORTHERN SHERIDAN...AND A LARGE PORTION OF CHERRY
COUNTY.
ON FRIDAY...LIGHT SRLY WINDS WILL DEVELOP AS A WARM FRONT LIFTS
NORTHEAST OF THE FORECAST AREA. WARMER H85 AIR WILL PUSH INTO
NORTHERN NEBRASKA FRIDAY AFTERNOON...RESULTING IN HIGHS IN THE
MIDDLE 50S. SIDED WITH THE COOLER MET GUIDANCE...ESPECIALLY OVER
CHERRY AND SHERIDAN COUNTY...WHERE SNOW COVER IS EXPECTED TO PERSIST
AT LEAST THROUGH MIDDAY FRIDAY. ELSEWHERE...HIGHS SHOULD TOP OUT IN
THE UPPER 50S AND LOWER 60S UNDER SUNNY SKIES. HIGH LEVEL CLOUD
COVER WILL BE ON THE INCREASE FRIDAY NIGHT...AS AN UPPER LEVEL JET
STREAK CROSSES THE NORTHERN ROCKIES AND NORTHERN PLAINS. WITH DECENT
AGREEMENT BETWEEN THE GFS AND NAM SOLNS WITH RESPECT TO THE DEGREE
OF UPPER LEVEL MOISTURE...OPTED TO INCREASE CLOUD COVER FRIDAY NIGHT
AND BOOSTED MIN TEMPS ACCORDINGLY WITH MOSTLY CLOUDY SKIES EXPECTED.
SATURDAY AND SUNDAY...SKIES WILL CLEAR SATURDAY MORNING AS THE
BEFORE MENTIONED JET STREAK PUSHES INTO THE UPPER MIDWEST. AT THE
SAME TIME...A SURFACE TROUGH OF LOW PRESSURE WILL TRACK ACROSS THE
DAKOTAS...SHIFTING WINDS TO THE WEST SATURDAY AFTERNOON. THE
COMBINATION OF FULL SUN...WESTERLY WINDS AND H85 TEMPS IN THE LOWER
TEENS C...WILL RESULT IN HIGHS IN THE MID 60S. SOME TEMPS MAY TOP OUT
IN THE LOWER 70S IN THE FAR SOUTHWEST AS H85 TEMPS APPROACH THE
MIDDLE TEENS C. ON SUNDAY...A SURFACE TROUGH OF LOW PRESSURE WILL
DEEPEN ACROSS THE PANHANDLE...SHIFTING WINDS FROM THE WEST TO THE
SOUTH AND INCREASING THEM TO 10 TO 20 MPH SUNDAY AFTERNOON. BASED ON
H85 TEMPS AND DECENT MIXING POTENTIAL...ANOTHER DAY OF HIGHS IN THE
60S LOOKS ON TRACK.
LONG RANGE...MONDAY THROUGH THURSDAY...A TANDEM OF COLD FRONTS WILL
TRACK ACROSS THE REGION NEXT WEEK...THE FIRST ON MONDAY...WHICH WILL
BE PRIMARILY A WIND PRODUCER...AND A SECOND ON WEDNESDAY NIGHT.
HIGHS NEXT WEEK WILL BE COOLER THAN THIS WEEKENDS READINGS...WITH
HIGHS IN THE 50S EXPECTED. ARCTIC AIR MAY BEGIN TO APPROACH THE
NORTHERN PLAINS ON THURSDAY...WITH THE GFS PUSHING AN ARCTIC FRONT
THROUGH WRN AND NORTH CENTRAL NEBRASKA THURSDAY...WHILE THE ECMWF
SOLN DELAYS THIS A COUPLE OF DAYS. DECIDED TO KEEP TEMPS WARM AND
DELAY ANY POTENTIAL ARCTIC FROPA TIL AFTER DAY 7 BASED ON THE SLOWER
ECMWF SOLN. DRY CONDS WILL CONTINUE INTO THE EXTENDED AS WELL.
AVIATION...
FOR THE 18Z TAF ISSUANCE...VISUAL FLIGHT RULES THROUGH MIDDAY FRIDAY
OVER WESTERN AND NORTH CENTRAL NEBRASKA WITH PASSING HIGH CLOUDS AOA
20K FT MOVING IN THE WESTERLIES OVER THE AREA. GENERALLY WESTERLY
FLOW WOULD BE EXPECTED AT THE SURFACE FOR AREA TERMINALS...WHICH
SHOULD REMAIN AOB 12KTS THROUGH AFTERNOON...THEN GOING LIGHT AND
VARIABLE THEREAFTER. ONE EXCEPTION BEING ACROSS THE FAR WESTERN
SANDHILLS...WHERE WIND GUSTS TO 20KTS OR HIGHER WILL CONTINUE.
RECENT METARS OVER THE WESTERN PANHANDLE REGION ACTUALLY INDICATE
MUCH STRONGER WIND SPEEDS...WHICH NEAR TERM MODEL GUIDANCE HINTS AT
SOME OF THIS MOMENTUM SPREADING EAST...TO POSSIBLY A KOGA TO KIEN
LINE....WHICH SEEMS PLAUSIBLE. REGARDLESS...WIND SPEEDS WOULD
DECREASE SHORTLY AFTER SUNDOWN.
FIRE WEATHER...
NEAR CRITICAL FIRE WEATHER CONDITIONS TO CONTINUE THROUGH LATE
AFTERNOON TODAY ACROSS SOUTHWEST NEBRASKA AND THE SOUTHEASTERN
PANHANDLE...WITH SIMILAR CONDITIONS EXPECTED OVER THE SAME AREA
TOMORROW. ABNORMALLY WARM...DRY AIRMASS HAS SETTLED ACROSS THE
REGION...WITH SURFACE RELATIVE HUMIDITY FALLING BELOW 15 PERCENT
OVER MUCH OF FIRE ZONE 210...AND OVER SOUTHERN PORTIONS OF 204.
EXPECTING THIS TREND TO CONTINUE THROUGH LATE AFTERNOON TODAY...WITH
SOME LOCATIONS POSSIBLY RECORDING MINIMUM RH OF LESS THAN 10 PERCENT
/MAINLY SOUTH OF INTERSTATE 80/. AFTER SUNDOWN...RH VALUES WILL
INCREASE STEADILY WITH THE COOLING TEMPERATURES. FOR TOMORROW...A
WEAK FRONTAL BOUNDARY WILL ALLOW FOR SLIGHTLY COOLER
TEMPERATURES...BUT WITH THE DRY AIRMASS...RH WILL ONCE AGAIN FALL TO
20 PERCENT OR LESS. ELSEWHERE...RESIDUAL MOISTURE FROM SNOWFALL
LAST WEEK WILL HELP KEEP MINIMUM RH VALUES AT OR ABOVE 25 PERCENT.
NOW ONTO THE WIND COMPONENT...A CRAIG HIGH HAS DEVELOPED /FAVORABLE
PATTERN FOR GUSTY WESTERLY WIND OVER THE PANHANDLE REGION/...WIND
GUSTS TO 25 MPH MAY BE POSSIBLE ACROSS THE FAR EASTERN PANHANDLE
THROUGH LATE AFTERNOON TODAY...BUT THE STRONGEST WIND SPEEDS WILL
REMAIN FURTHER WEST /WESTERN AND CENTRAL PANHANDLE INTO WYOMING/.
BREEZY WIND SPEEDS CAN BE EXPECTED ONCE AGAIN FOR FRIDAY...BUT AGAIN
THE STRONGER WIND GUSTS /ALBEIT 25 MPH OR LESS/ WILL BE OUT OVER THE
EASTERN PANHANDLE...WITH LIGHTER WIND SPEEDS /15 MPH OR LESS/ FOR ALL
OTHER AREAS.
GIVEN THE MARGINALITY OF THE FIRE WEATHER CONDITIONS...NO FIRE
HEADLINES ARE ANTICIPATED TODAY OR TOMORROW...BUT LOCALIZED RFW
CONDITIONS MAY EXIST FOR AN HOUR OR TWO LATE THIS AFTERNOON AND
POSSIBLY LATE TOMORROW FOR PORTIONS OF FIRE ZONE 204 AND 210.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM/EXTENDED...MASEK
AVIATION...CDC
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1126 PM CST THU NOV 29 2012
.UPDATE...
.AVIATION...
VFR IS EXPECTED ALL AREAS OVERNIGHT THROUGH FRIDAY EVENING.
AN AREA OF LIFR CIGS ALONG THE MISSOURI RIVER IN SD WILL MOVE
SOUTHEAST OVERNIGHT SQUIRTING THE NEB BORDER. OTHERWISE SCT-BKN
HIGH LEVEL CLOUDINESS WILL CONTINUE THROUGH FRIDAY EVENING.
&&
.PREV DISCUSSION... /ISSUED 500 PM CST THU NOV 29 2012/
UPDATE...
AVIATION...
VFR IS EXPECTED ALL AREAS OVERNIGHT THROUGH FRIDAY.
AN ARCTIC FRONT ACROSS CNTL SD THIS EVENING WILL DROP SOUTH AND
INTO NCNTL NEB OVERNIGHT. THE FRONT IS NOT EXPECTED TO PRODUCE ANY FLIGHT
LIMITATIONS AT THIS TIME. THE RAP MODEL...ETAL SUGGEST STRATUS
WILL FROM ALONG AND NORTH OF THE MISSOURI RIVER...EAST OF THE FCST
AREA.
OTHERWISE SCT-BKN HIGH LEVEL CLOUDINESS WILL CONTINUE THROUGH
FRIDAY.
PREV DISCUSSION... /ISSUED 305 PM CST THU NOV 29 2012/
SYNOPSIS...
12Z H5 HAND ANALYSIS FROM THIS MORNING WAS INDICATING BROAD ZONAL
FLOW EXTENDING ACROSS THE CONUS. LOW PRESSURE WAS PRESENT ACROSS
NORTH CENTRAL CANADA...NRN QUEBEC...AND OFF THE COAST OF BRITISH
COLUMBIA. FURTHER SOUTH ACROSS THE CONUS...STRONG MID AND UPPER
LEVEL FLOW...HAS SPREAD ABUNDANT MID AND HIGH LEVEL CLOUDINESS
ACROSS THE WESTERN THIRD OF THE CONUS TDY. SCATTERED TO BROKEN UPPER
LEVEL CLOUDINESS WHICH WAS PRESENT ACROSS CENTRAL AND NORTHERN
NEBRASKA EARLIER THIS MORNING...AND HAS SHIFTED EAST BY MIDDAY.
UNDER SUNNY SKIES...TEMPERATURES AS OF 2 PM CST...RANGED FROM 46 AT
AINSWORTH...TO 70 AT IMPERIAL.
DISCUSSION...
SHORT RANGE...TONIGHT THROUGH SUNDAY NIGHT...FORECASTING CHALLENGE
WILL BE TEMPERATURES AND THE IMPACT OF CLOUD COVER AND SNOW COVER ON
THEM.
FOR TONIGHT...A WEAK DISTURBANCE WILL TRACK ACROSS THE
DAKOTAS...BACKING A WEAK COOL FRONT INTO NORTHERN NEBRASKA TONIGHT.
THE SRN SURGE OF THE FRONT IS EXPECTED TO REACH THE CENTRAL FORECAST
AREA OVERNIGHT...LIFTING NORTH AS A WARM FRONT ON FRIDAY. LOWS
TONIGHT WILL BE COOLEST IN THE PLATTE RIVER VALLEY WITH LIGHT
WESTERLY WINDS...AND ACROSS THE SNOWFIELD IN THE NRN CWA...WHICH
WILL ENCOMPASS NORTHERN SHERIDAN...AND A LARGE PORTION OF CHERRY
COUNTY.
ON FRIDAY...LIGHT SRLY WINDS WILL DEVELOP AS A WARM FRONT LIFTS
NORTHEAST OF THE FORECAST AREA. WARMER H85 AIR WILL PUSH INTO
NORTHERN NEBRASKA FRIDAY AFTERNOON...RESULTING IN HIGHS IN THE
MIDDLE 50S. SIDED WITH THE COOLER MET GUIDANCE...ESPECIALLY OVER
CHERRY AND SHERIDAN COUNTY...WHERE SNOW COVER IS EXPECTED TO PERSIST
AT LEAST THROUGH MIDDAY FRIDAY. ELSEWHERE...HIGHS SHOULD TOP OUT IN
THE UPPER 50S AND LOWER 60S UNDER SUNNY SKIES. HIGH LEVEL CLOUD
COVER WILL BE ON THE INCREASE FRIDAY NIGHT...AS AN UPPER LEVEL JET
STREAK CROSSES THE NORTHERN ROCKIES AND NORTHERN PLAINS. WITH DECENT
AGREEMENT BETWEEN THE GFS AND NAM SOLNS WITH RESPECT TO THE DEGREE
OF UPPER LEVEL MOISTURE...OPTED TO INCREASE CLOUD COVER FRIDAY NIGHT
AND BOOSTED MIN TEMPS ACCORDINGLY WITH MOSTLY CLOUDY SKIES EXPECTED.
SATURDAY AND SUNDAY...SKIES WILL CLEAR SATURDAY MORNING AS THE
BEFORE MENTIONED JET STREAK PUSHES INTO THE UPPER MIDWEST. AT THE
SAME TIME...A SURFACE TROUGH OF LOW PRESSURE WILL TRACK ACROSS THE
DAKOTAS...SHIFTING WINDS TO THE WEST SATURDAY AFTERNOON. THE
COMBINATION OF FULL SUN...WESTERLY WINDS AND H85 TEMPS IN THE LOWER
TEENS C...WILL RESULT IN HIGHS IN THE MID 60S. SOME TEMPS MAY TOP OUT
IN THE LOWER 70S IN THE FAR SOUTHWEST AS H85 TEMPS APPROACH THE
MIDDLE TEENS C. ON SUNDAY...A SURFACE TROUGH OF LOW PRESSURE WILL
DEEPEN ACROSS THE PANHANDLE...SHIFTING WINDS FROM THE WEST TO THE
SOUTH AND INCREASING THEM TO 10 TO 20 MPH SUNDAY AFTERNOON. BASED ON
H85 TEMPS AND DECENT MIXING POTENTIAL...ANOTHER DAY OF HIGHS IN THE
60S LOOKS ON TRACK.
LONG RANGE...MONDAY THROUGH THURSDAY...A TANDEM OF COLD FRONTS WILL
TRACK ACROSS THE REGION NEXT WEEK...THE FIRST ON MONDAY...WHICH WILL
BE PRIMARILY A WIND PRODUCER...AND A SECOND ON WEDNESDAY NIGHT.
HIGHS NEXT WEEK WILL BE COOLER THAN THIS WEEKENDS READINGS...WITH
HIGHS IN THE 50S EXPECTED. ARCTIC AIR MAY BEGIN TO APPROACH THE
NORTHERN PLAINS ON THURSDAY...WITH THE GFS PUSHING AN ARCTIC FRONT
THROUGH WRN AND NORTH CENTRAL NEBRASKA THURSDAY...WHILE THE ECMWF
SOLN DELAYS THIS A COUPLE OF DAYS. DECIDED TO KEEP TEMPS WARM AND
DELAY ANY POTENTIAL ARCTIC FROPA TIL AFTER DAY 7 BASED ON THE SLOWER
ECMWF SOLN. DRY CONDS WILL CONTINUE INTO THE EXTENDED AS WELL.
AVIATION...
FOR THE 18Z TAF ISSUANCE...VISUAL FLIGHT RULES THROUGH MIDDAY FRIDAY
OVER WESTERN AND NORTH CENTRAL NEBRASKA WITH PASSING HIGH CLOUDS AOA
20K FT MOVING IN THE WESTERLIES OVER THE AREA. GENERALLY WESTERLY
FLOW WOULD BE EXPECTED AT THE SURFACE FOR AREA TERMINALS...WHICH
SHOULD REMAIN AOB 12KTS THROUGH AFTERNOON...THEN GOING LIGHT AND
VARIABLE THEREAFTER. ONE EXCEPTION BEING ACROSS THE FAR WESTERN
SANDHILLS...WHERE WIND GUSTS TO 20KTS OR HIGHER WILL CONTINUE.
RECENT METARS OVER THE WESTERN PANHANDLE REGION ACTUALLY INDICATE
MUCH STRONGER WIND SPEEDS...WHICH NEAR TERM MODEL GUIDANCE HINTS AT
SOME OF THIS MOMENTUM SPREADING EAST...TO POSSIBLY A KOGA TO KIEN
LINE....WHICH SEEMS PLAUSIBLE. REGARDLESS...WIND SPEEDS WOULD
DECREASE SHORTLY AFTER SUNDOWN.
FIRE WEATHER...
NEAR CRITICAL FIRE WEATHER CONDITIONS TO CONTINUE THROUGH LATE
AFTERNOON TODAY ACROSS SOUTHWEST NEBRASKA AND THE SOUTHEASTERN
PANHANDLE...WITH SIMILAR CONDITIONS EXPECTED OVER THE SAME AREA
TOMORROW. ABNORMALLY WARM...DRY AIRMASS HAS SETTLED ACROSS THE
REGION...WITH SURFACE RELATIVE HUMIDITY FALLING BELOW 15 PERCENT
OVER MUCH OF FIRE ZONE 210...AND OVER SOUTHERN PORTIONS OF 204.
EXPECTING THIS TREND TO CONTINUE THROUGH LATE AFTERNOON TODAY...WITH
SOME LOCATIONS POSSIBLY RECORDING MINIMUM RH OF LESS THAN 10 PERCENT
/MAINLY SOUTH OF INTERSTATE 80/. AFTER SUNDOWN...RH VALUES WILL
INCREASE STEADILY WITH THE COOLING TEMPERATURES. FOR TOMORROW...A
WEAK FRONTAL BOUNDARY WILL ALLOW FOR SLIGHTLY COOLER
TEMPERATURES...BUT WITH THE DRY AIRMASS...RH WILL ONCE AGAIN FALL TO
20 PERCENT OR LESS. ELSEWHERE...RESIDUAL MOISTURE FROM SNOWFALL
LAST WEEK WILL HELP KEEP MINIMUM RH VALUES AT OR ABOVE 25 PERCENT.
NOW ONTO THE WIND COMPONENT...A CRAIG HIGH HAS DEVELOPED /FAVORABLE
PATTERN FOR GUSTY WESTERLY WIND OVER THE PANHANDLE REGION/...WIND
GUSTS TO 25 MPH MAY BE POSSIBLE ACROSS THE FAR EASTERN PANHANDLE
THROUGH LATE AFTERNOON TODAY...BUT THE STRONGEST WIND SPEEDS WILL
REMAIN FURTHER WEST /WESTERN AND CENTRAL PANHANDLE INTO WYOMING/.
BREEZY WIND SPEEDS CAN BE EXPECTED ONCE AGAIN FOR FRIDAY...BUT AGAIN
THE STRONGER WIND GUSTS /ALBEIT 25 MPH OR LESS/ WILL BE OUT OVER THE
EASTERN PANHANDLE...WITH LIGHTER WIND SPEEDS /15 MPH OR LESS/ FOR ALL
OTHER AREAS.
GIVEN THE MARGINALITY OF THE FIRE WEATHER CONDITIONS...NO FIRE
HEADLINES ARE ANTICIPATED TODAY OR TOMORROW...BUT LOCALIZED RFW
CONDITIONS MAY EXIST FOR AN HOUR OR TWO LATE THIS AFTERNOON AND
POSSIBLY LATE TOMORROW FOR PORTIONS OF FIRE ZONE 204 AND 210.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM/EXTENDED...MASEK
AVIATION...CDC
AREA FORECAST DISCUSSION...CORRECTED
NWS PORTLAND OR
900 PM PST THU NOV 29 2012
.SYNOPSIS...A BROAD UPPER LOW OVER THE NE PACIFIC WILL SEND A SERIES
OF FRONTS ACROSS THE PACIFIC NW THROUGH THE WEEKEND. SHOWERS WILL
PERSIST TONIGHT IN THE WAKE OF A COLD FRONT..AND INCREASE FRIDAY
MORNING AS THE NEXT SYSTEM APPROACHES. THE NEXT FRONT WILL MOVE
THROUGH FRIDAY NIGHT AND SATURDAY MORNING. SNOW LEVELS WILL LOWER TO
PASS LEVEL WITH THIS SYSTEM. ANOTHER FRONT IS EXPECTED SATURDAY NIGHT
AND SUNDAY MORNING.
&&
.SHORT TERM...A MASSIVE TROUGH OVER THE EASTERN PACIFIC WILL CONTINUE
TO SPIN EMBEDDED SHORTWAVE TROUGHS ACROSS THE REGION THROUGH THE
WEEKEND. WE ARE CURRENTLY NEAR THE LEFT EXIT REGION OF AN UPPER LEVEL
JET...WHICH HAS LIKELY AIDED IN THE DEVELOPMENT OF A QUASI BAROCLINIC
LEAF OVER WEST CENTRAL OREGON. PER RADAR IMAGERY...WIDESPREAD RAIN
SHOWERS ARE SPREADING NORTHEASTWARD ACROSS THE AREA THIS EVENING.
ONCE THIS WAVE PASSES...EXPECT AT LEAST A TEMPORARY LULL IN PRECIP
ACROSS THE VALLEY DURING THE EARLY MORNING HOURS. SATELLITE
EXTRAPOLATION AND THE HRRR SUPPORT THIS GENERAL IDEA.
ANOTHER EMBEDDED VORT MAX CURRENTLY APPROACHING 130W WILL BE LAPPING
ON OUR DOORSTEP EARLY FRIDAY MORNING...WHICH SHOULD RESULT IN ANOTHER
UPTICK IN SHOWER ACTIVITY...PARTICULARLY ALONG THE COAST.
A THIRD VORT MAX CURRENTLY NEAR 50N AND 150W WILL PUSH ASHORE FRIDAY
EVENING RESULTING IN A BAND OF HEAVIER RAIN THAT WILL DROP
SOUTHEASTWARD ACROSS THE CWA FRIDAY EVENING INTO FRIDAY NIGHT. THE
COAST RANGE WILL LIKELY RECEIVE A COUPLE INCHES OF RAIN FROM THIS
EVENT...BUT AT THIS TIME...MAIN STEM RIVER FLOODING IS NOT
ANTICIPATED.
FINALLY...THE MODELS ARE IN RELATIVELY GOOD AGREEMENT THAT ANOTHER
VORT MAX AND SHORTWAVE TROUGH CURRENTLY NEAR THE ALEUTIAN ISLANDS
WILL SWING INTO THE REGION SATURDAY NIGHT. WE WILL ONCE AGAIN BE IN
THE VICINITY OF THE LEFT EXIT REGION OF A JET...THIS TIME AROUND NEAR
150KTS. CYCLOGENESIS WILL BE POSSIBLE OFF OUR WATERS AND THIS IS
WHERE THE MODELS DIVERGE IN THEIR SOLUTIONS. THE EC HINTS AT A WAVE
DEVELOPING...BUT DOES NOT DEVELOP A CLOSED LOW. THE LATEST GFS AND
GEM ARE OPEN WAVE-LIKE...BUT DO DEVELOP A CLOSED 993MB AND 987 MB
LOW...RESPECTIVELY. BOTH MODELS MOVE THEIR RESPECTIVE LOW PRESSURES
INTO THE SOUTH CENTRAL OREGON COAST. MEANWHILE...THE NAM DEVELOPS A
CLOSED LOW EARLY ON...AND BRINGS A 985MB LOW INTO THE NORTH CENTRAL
OREGON COAST. THIS WOULD ALMOST CERTAINLY RESULT IN A SIGNIFICANT WIND
EVENT FOR AT LEAST PORTIONS OF THE OREGON COAST. GIVEN THIS IS A
COUPLE DAYS AWAY AND SUBTLE DIFFERENCES IN THE SYNOPTIC PATTERN CAN
DRASTICALLY CHANGE CYCLOGENESIS...A HYBRID OF THE GLOBAL MODELS IS
FAVORED...BUT THIS WILL NONETHELESS BEAR WATCHING.
IT SHOULD ALSO BE NOTED THAT A MORE OPEN WAVE LIKE PATTERN AS
DEPICTED BY THE EC WOULD LIKELY RESULT IN LOWER SNOW LEVELS AND
HIGHLIGHT WORTHY SNOWS FOR THE CASCADE PASSES. IN CONTRAST...WARM
AIR WOULD LIKELY SURGE NORTHWARD AHEAD OF THE DEVELOPING LOW
PRESSURE...PARTICULARLY IN THE NAM SCENARIO...RESULTING IN SNOW
LEVELS AT LEAST 1.5-3KFT HIGHER.
MAIN EDITS THIS EVENING WERE TO ADJUST SNOW LEVELS DOWN A BIT GIVEN
SNOW ACCUMULATIONS ALONG THE CASCADE CREST PER WEB CAMS...AND TO
INCREASE POPS A BIT OVER THE NEXT COUPLE OF DAYS GIVEN GENERAL MODEL
CONSENSUS. /NEUMAN
.LONG TERM...A SHORTWAVE UPPER RIDGE WILL MOVE OVER THE REGION MONDAY
AND PROVIDE A BRIEF BREAK IN THE MOIST WEATHER...ALTHOUGH MOIST
ONSHORE FLOW WILL LIKELY CONTINUE SHOWERS. ANOTHER UPPER LOW WILL
DROP INTO THE NE PACIFIC MONDAY AND BRING A WET FRONT THROUGH THE
REGION TUESDAY AND WEDNESDAY. MODELS HAVE STILL SHOW THE POTENTIAL
FOR AN ATMOSPHERIC RIVER EVENT WITH THIS SYSTEM...WHICH WILL BRING
THE POSSIBILITY OF HEAVY RAINFALL AND POTENTIAL FOR ANOTHER ROUND OF
HIGH RIVER LEVELS. THE MODELS HINT OF SOME SORT OF RIDGING AND
POSSIBLY DRY WEATHER LATE NEXT WEEK.
&&
.AVIATION...MOSTLY VFR CONDITIONS THIS EVENING. LOOK FOR AREAS OF
MVFR STRATUS TO DEVELOP LATE TONIGHT BOTH ALONG THE COAST AND
INLAND. VFR CONDITIONS WILL RETURN OVER INLAND LATE FRI MORNING
AND CONTINUE DURING THE AFTERNOON. EXPECT A MIX OF MVFR ALONG THE
COAST ON FRIDAY.
KPDX AND APPROACHES...VFR CIGS AND VSBY THROUGH THIS EVENING. EXPECT
MVFR STRATUS DESK BETWEEN 020 AND 030 TO DEVELOP LATE TONIGHT AND
LIFT BACK TO VFR SHORTLY BEFORE NOON ON FRIDAY. E TO SE WINDS WILL
CONTINUE THROUGH FRIDAY. TODD/BROWN
&&
.MARINE...STRONG SMALL CRAFT ADVISORY WINDS OVER THE MARINE
WATERS THIS EVENING SHOULD CONTINUE OVERNIGHT AND INTO FRIDAY.
MODELS CONTINUE TO ADVERTISE THE POSSIBILITY OF MARGINAL GALES
ACROSS MAINLY THE SOUTHERN WATERS BEGINNING FRIDAY AFTERNOON AHEAD
OF THE NEXT SYSTEM. AS A RESULT...A GALE WATCH HAS BEEN ISSUED FOR
FRIDAY AFTERNOON THROUGH FRIDAY NIGHT. FULLY EXPECT SMALL CRAFT WINDS
AT THE LEAST TO CONTINUE ACROSS ALL WATERS THROUGH SATURDAY.
SEAS WILL REMAIN IN THE MID TEENS THROUGH SATURDAY. SEAS MAY PICK
UP TO THE UPPER TEENS FRIDAY NIGHT INTO SATURDAY WITH THE
SYSTEM...ESPECIALLY ACROSS THE SOUTHERN WATERS. SEAS ARE THEN
EXPECTED TO GRADUALLY DROP TO NEAR 10 FT BY LATE SUNDAY. BROWN
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 10 PM PST SATURDAY FOR
COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR OUT 60
NM.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM PST SUNDAY
FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR
OUT 60 NM.
GALE WATCH FROM FRIDAY MORNING THROUGH LATE FRIDAY NIGHT FOR
COASTAL WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR WINDS UNTIL 10 AM PST FRIDAY FOR
COASTAL WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 AM PST FRIDAY
FOR COASTAL WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT 60
NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 10 PM
PST FRIDAY.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...HTTP://WEATHER.GOV/PORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS PORTLAND OR
850 PM PST THU NOV 29 2012
.SYNOPSIS...A BROAD UPPER LOW OVER THE NE PACIFIC WILL SEND A SERIES
OF FRONTS ACROSS THE PACIFIC NW THROUGH THE WEEKEND. SHOWERS WILL
PERSIST TONIGHT IN THE WAKE OF A COLD FRONT..AND INCREASE FRIDAY
MORNING AS THE NEXT SYSTEM APPROACHES. THE NEXT FRONT WILL MOVE
THROUGH FRIDAY NIGHT AND SATURDAY MORNING. SNOW LEVELS WILL LOWER TO
PASS LEVEL WITH THIS SYSTEM. ANOTHER FRONT IS EXPECTED SATURDAY NIGHT
AND SUNDAY MORNING.
&&
.SHORT TERM...A MASSIVE TROUGH OVER THE EASTERN PACIFIC WILL CONTINUE
TO SPIN EMBEDDED SHORTWAVE TROUGHS ACROSS THE REGION THROUGH THE
WEEKEND. WE ARE CURRENTLY NEAR THE LEFT EXIT REGION OF AN UPPER LEVEL
JET...WHICH HAS LIKELY AIDED IN THE DEVELOPMENT OF A QUASI BAROCLINIC
LEAF OVER WEST CENTRAL OREGON. PER RADAR IMAGERY...WIDESPREAD RAIN
SHOWERS ARE SPREADING NORTHEASTWARD ACROSS THE AREA THIS EVENING.
ONCE THIS WAVE PASSES...EXPECT AT LEAST A TEMPORARY LULL IN PRECIP
ACROSS THE VALLEY DURING THE EARLY MORNING HOURS. SATELLITE
EXTRAPOLATION AND THE HRRR SUPPORT THIS GENERAL IDEA.
ANOTHER EMBEDDED VORT MAX CURRENTLY APPROACHING 130W WILL BE LAPPING
ON OUR DOORSTEP EARLY FRIDAY MORNING...WHICH SHOULD RESULT IN ANOTHER
UPTICK IN SHOWER ACTIVITY...PARTICULARLY ALONG THE COAST.
A THIRD VORT MAX CURRENTLY NEAR 50N AND 150W WILL PUSH ASHORE FRIDAY
EVENING RESULTING IN A BAND OF HEAVIER RAIN THAT WILL DROP
SOUTHEASTWARD ACROSS THE CWA FRIDAY EVENING INTO FRIDAY NIGHT. THE
COAST RANGE WILL LIKELY RECEIVE A COUPLE INCHES OF RAIN FROM THIS
EVENT...BUT AT THIS TIME...MAIN STEM RIVER FLOODING IS NOT
ANTICIPATED.
FINALLY...THE MODELS ARE IN RELATIVELY GOOD AGREEMENT THAT ANOTHER
VORT MAX AND SHORTWAVE TROUGH CURRENTLY NEAR THE ALEUTIAN ISLANDS
WILL SWING INTO THE REGION SATURDAY NIGHT. WE WILL ONCE AGAIN BE IN
THE VICINITY OF THE LEFT EXIT REGION OF A JET...THIS TIME AROUND NEAR
150KTS. CYCLOGENESIS WILL BE POSSIBLE OFF OUR WATERS AND THIS IS
WHERE THE MODELS DIVERGE IN THEIR SOLUTIONS. THE EC HINTS AT A WAVE
DEVELOPING...BUT DOES NOT DEVELOP A CLOSED LOW. THE LATEST GFS AND
GEM ARE OPEN WAVE-LIKE...BUT DO DEVELOP A CLOSED 993MB AND 987 MB
LOW...RESPECTIVELY. BOTH MODELS MOVE THEIR RESPECTIVE LOW PRESSURES
INTO THE SOUTH CENTRAL OREGON COAST. MEANWHILE...THE NAM DEVELOPS A
CLOSED LOW EARLY ON...AND BRINGS A 985MB LOW INTO THE NORTH CENTRAL
OREGON COAST. THIS WOULD ALMOST CERTAINLY RESULT IN A SIGNIFICANT WIND
EVENT FOR AT LEAST PORTIONS OF THE OREGON COAST. GIVEN THIS IS A
COUPLE DAYS AWAY AND SUBTLE DIFFERENCES IN THE SYNOPTIC PATTERN CAN
DRASTICALLY CHANGE CYCLOGENESIS...THE GLOBAL MODELS ARE FAVORED...BUT
THIS WILL NONETHELESS BEAR WATCHING.
IT SHOULD ALSO BE NOTED THAT A MORE OPEN WAVE LIKE THAT DEPICTED BY
THE EC WOULD LIKELY RESULT IN LOWER SNOW LEVELS AND HIGHLIGHT WORTHY
SNOWS FOR THE CASCADE PASSES. IN CONTRAST...WARM AIR WOULD LIKELY
SURGE NORTHWARD AHEAD OF THE DEVELOPING LOW PRESSURE...PARTICULARLY
IN THE NAM SCENARIO...RESULTING IN SNOW LEVELS AT LEAST 1.5-3KFT
HIGHER.
MAIN EDITS THIS EVENING WERE TO ADJUST SNOW LEVELS DOWN A BIT GIVEN
SNOW ACCUMULATIONS ALONG THE CASCADE CREST PER WEB CAMS...AND TO
INCREASE POPS A BIT OVER THE NEXT COUPLE OF DAYS GIVEN GENERAL MODEL
CONSENSUS. /NEUMAN
.LONG TERM...A SHORTWAVE UPPER RIDGE WILL MOVE OVER THE REGION MONDAY
AND PROVIDE A BRIEF BREAK IN THE MOIST WEATHER...ALTHOUGH MOIST
ONSHORE FLOW WILL LIKELY CONTINUE SHOWERS. ANOTHER UPPER LOW WILL
DROP INTO THE NE PACIFIC MONDAY AND BRING A WET FRONT THROUGH THE
REGION TUESDAY AND WEDNESDAY. MODELS HAVE STILL SHOW THE POTENTIAL
FOR AN ATMOSPHERIC RIVER EVENT WITH THIS SYSTEM...WHICH WILL BRING
THE POSSIBILITY OF HEAVY RAINFALL AND POTENTIAL FOR ANOTHER ROUND OF
HIGH RIVER LEVELS. THE MODELS HINT OF SOME SORT OF RIDGING AND
POSSIBLY DRY WEATHER LATE NEXT WEEK.
&&
.AVIATION...MOSTLY VFR CONDITIONS THIS EVENING. LOOK FOR AREAS OF
MVFR STRATUS TO DEVELOP LATE TONIGHT BOTH ALONG THE COAST AND
INLAND. VFR CONDITIONS WILL RETURN OVER INLAND LATE FRI MORNING
AND CONTINUE DURING THE AFTERNOON. EXPECT A MIX OF MVFR ALONG THE
COAST ON FRIDAY.
KPDX AND APPROACHES...VFR CIGS AND VSBY THROUGH THIS EVENING. EXPECT
MVFR STRATUS DESK BETWEEN 020 AND 030 TO DEVELOP LATE TONIGHT AND
LIFT BACK TO VFR SHORTLY BEFORE NOON ON FRIDAY. E TO SE WINDS WILL
CONTINUE THROUGH FRIDAY. TODD/BROWN
&&
.MARINE...STRONG SMALL CRAFT ADVISORY WINDS OVER THE MARINE
WATERS THIS EVENING SHOULD CONTINUE OVERNIGHT AND INTO FRIDAY.
MODELS CONTINUE TO ADVERTISE THE POSSIBILITY OF MARGINAL GALES
ACROSS MAINLY THE SOUTHERN WATERS BEGINNING FRIDAY AFTERNOON AHEAD
OF THE NEXT SYSTEM. AS A RESULT...A GALE WATCH HAS BEEN ISSUED FOR
FRIDAY AFTERNOON THROUGH FRIDAY NIGHT. FULLY EXPECT SMALL CRAFT WINDS
AT THE LEAST TO CONTINUE ACROSS ALL WATERS THROUGH SATURDAY.
SEAS WILL REMAIN IN THE MID TEENS THROUGH SATURDAY. SEAS MAY PICK
UP TO THE UPPER TEENS FRIDAY NIGHT INTO SATURDAY WITH THE
SYSTEM...ESPECIALLY ACROSS THE SOUTHERN WATERS. SEAS ARE THEN
EXPECTED TO GRADUALLY DROP TO NEAR 10 FT BY LATE SUNDAY. BROWN
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 10 PM PST SATURDAY FOR
COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR OUT 60
NM.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM PST SUNDAY
FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR
OUT 60 NM.
GALE WATCH FROM FRIDAY MORNING THROUGH LATE FRIDAY NIGHT FOR
COASTAL WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR WINDS UNTIL 10 AM PST FRIDAY FOR
COASTAL WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 AM PST FRIDAY
FOR COASTAL WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT 60
NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 10 PM
PST FRIDAY.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...HTTP://WEATHER.GOV/PORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION...UPDATED
NWS NASHVILLE TN
1005 AM CST FRI NOV 30 2012
.UPDATE...FOR 18Z AVIATION DISCUSSION.
&&
.AVIATION...18Z AVIATION DISCUSSION.
SFC RIDGING INFLUENCES WILL CONTINUE TO PLAY MAJOR ROLE IN WX
THRU 01/18Z...WITH SFC PRESSURE GRADIENT CONTINUING TO HOLD.
WEAK DISTURBANCES ALOFT MIGHT BRING SOME SCT/BKN CI THRU TIME
PERIOD ALSO. ANTICIPATE CURRENT STRATO CU BKN CEILINGS NEAR CSV
TO DISSIPATE BEFORE OR SLIGHTLY AFTER 30/18Z PER ATM MIXING
INFLUENCES BECOMING BETTER ESTABLISHED.
&&
.PREV DISCUSSION.../ISSUED 842 AM CST FRI NOV 30 2012/
UPDATE...UPDATED ZONE PACKAGE TO ACCOUNT FOR CURRENT CLOUD CONDITIONS
AND TRENDS.
PREV DISCUSSION.../ISSUED 626 AM CST FRI NOV 30 2012/
UPDATE...FOR 12Z AVIATION FORECAST
AVIATION...
STRATOCUMULUS ARE MOVING NORTH FROM ALABAMA BASED AROUND 25 HNDRD
FEET MSL. THESE CLOUDS APPEAR TO BE RIDING ALONG THE 290 KELVIN
SURFACE ON A SOUTHWESTERLY 30 KNOT LOW LEVEL JET. EXPECT THESE
CLOUDS TO BE AROUND THROUGH 14Z-15Z TIME FRAME OR UNTIL MIXING CAN
GET UNDERWAY...THEN THEY SHOULD THIN OUT. OTHERWISE LOOK FOR VFR
CONDITIONS TO PREVAIL THROUGH THE NEXT 24 HOURS WITH WINDS BECOMING
GUSTY DURING THE DAY AS SURFACE PRESSURE GRADIENT TIGHTENS A BIT
FROM CAROLINA HIGH PRESSURE CENTER TO OUR EAST AND CENTRAL PLAINS
LOW. EXPECT WIND GUSTS TO 18 KNOTS DURING THE DAY WITH WINDS
SUBSIDING BY EARLY EVENING.
BOYD
PREV DISCUSSION... /ISSUED 350 AM CST FRI NOV 30 2012/
DISCUSSION...
IN THE SHORT TERM...NOT MUCH TO SPEAK OF OTHER THAN SEEING IF
IMPROVEMENTS COULD BE MADE ON THE GFS TEMP INITIALIZATION. TRENDED A
BIT ABOVE THE GUIDANCE AS IT HAS BEEN TRENDING TOWARDS BEING TOO COOL
AS OF LATE. ALSO TWEAKED THE FIRST PERIOD SKY GRIDS TO INCLUDE THE
CIRRUS SEEN ON IR SATELLITE. NAM AND RUC LAYER RH SHOWS SOME
INCREASE IN LOW LEVEL RH THIS AFTERNOON WHICH SHOULD BRING A BIT OF
CLOUD COVER ON THE CUMBERLAND SO INCLUDED THIS INTO THE SKY GRIDS.
IN THE LONG TERM...THE FOCUS RESIDES ON THE UPCOMING FRONTAL PASSAGE
THAT IS PROGGED TO REACH MIDDLE TN BY TUESDAY AFTERNOON AS INDICATED
BY THE GFS OR EVENING PER THE ECMWF. LATEST MODEL RUNS ARE REALLY
LACKING APPRECIABLE INSTABILITY AND SHEAR. WHILE DYNAMICAL FORCING
WILL BE SUFFICIENT FOR RAIN WITH A LIGHTNING STRIKE OR TWO...THE
CONFIDENCE IN WIDESPREAD TSRA IS LOW. FORECAST SOUNDINGS...WHILE
VERY MOIST...SHOW NEARLY ZERO CAPE AND EVEN SOME CIN IN PLACE DURING
PEAK HEATING TUESDAY. LOOKS LIKE LIFT WILL BE MOSTLY DYNAMICAL AND
EVEN THAT COULD BE BETTER AS 500 MB WINDS ARE ONLY IN THE 35-40 KT
RANGE. FEEL PREVIOUS FORECAST WAS PRETTY GOOD FOR POP CHANCES AND
OTHER THAN FINE TUNING SOME TIMING AND WX WORDING...NOT MUCH WAS
CHANGED. FEEL LIKE THIS WILL BE A MODERATE TO HEAVY RAINER AND NOT
MUCH ELSE.
BEYOND THIS FRONTAL SYSTEM...A TRANSITION PERIOD OF WEAK RIDGING
PRIOR TO THE NEXT SIGNIFICANT FRONTAL PASSAGE. AS FAR AS THE MODEL
COMPARISON GOES...THE DEPICTION OF THE 500 MB LOW IS QUITE DIFFERENT
IN BOTH TIMING AND CHARACTER. GFS DEPICTION IS-NT QUITE AS DEEP WITH
THE HEIGHT FALLS...HOW FAR SOUTH THE LOW DIPS...OR AS SIGNIFICANT IN
THE POSITIVE TILT. THE ECMWF SOLUTION WOULD BE AN EYE OPENER FOR
STORM POSSIBILITIES AS IT GENERATES A HEALTHY PRE FRONTAL
TROUGH...NEAR 60 SFC DEWPOINTS AND A PROGGED 55 KT 850 MB JET. THE
ONLY REAL AGREEMENT IS THAT THE FRONT WILL EVENTUALLY PASS THROUGH
SOMETIME AROUND 12Z SATURDAY...GIVE OR TAKE 6 HOURS...AND IT WILL
PRODUCE RAIN. BECAUSE OF THIS...THATS WHAT WAS INCLUDED IN THE
GRIDS.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
31
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
842 AM CST FRI NOV 30 2012
.UPDATE...UPDATED ZONE PACKAGE TO ACCOUNT FOR CURRENT CLOUD CONDITIONS
AND TRENDS.
&&
.PREV DISCUSSION... /ISSUED 626 AM CST FRI NOV 30 2012/
UPDATE...FOR 12Z AVIATION FORECAST
AVIATION...
STRATOCUMULUS ARE MOVING NORTH FROM ALABAMA BASED AROUND 25 HNDRD
FEET MSL. THESE CLOUDS APPEAR TO BE RIDING ALONG THE 290 KELVIN
SURFACE ON A SOUTHWESTERLY 30 KNOT LOW LEVEL JET. EXPECT THESE
CLOUDS TO BE AROUND THROUGH 14Z-15Z TIME FRAME OR UNTIL MIXING CAN
GET UNDERWAY...THEN THEY SHOULD THIN OUT. OTHERWISE LOOK FOR VFR
CONDITIONS TO PREVAIL THROUGH THE NEXT 24 HOURS WITH WINDS BECOMING
GUSTY DURING THE DAY AS SURFACE PRESSURE GRADIENT TIGHTENS A BIT
FROM CAROLINA HIGH PRESSURE CENTER TO OUR EAST AND CENTRAL PLAINS
LOW. EXPECT WIND GUSTS TO 18 KNOTS DURING THE DAY WITH WINDS
SUBSIDING BY EARLY EVENING.
BOYD
PREV DISCUSSION... /ISSUED 350 AM CST FRI NOV 30 2012/
DISCUSSION...
IN THE SHORT TERM...NOT MUCH TO SPEAK OF OTHER THAN SEEING IF
IMPROVEMENTS COULD BE MADE ON THE GFS TEMP INITIALIZATION. TRENDED A
BIT ABOVE THE GUIDANCE AS IT HAS BEEN TRENDING TOWARDS BEING TOO COOL
AS OF LATE. ALSO TWEAKED THE FIRST PERIOD SKY GRIDS TO INCLUDE THE
CIRRUS SEEN ON IR SATELLITE. NAM AND RUC LAYER RH SHOWS SOME
INCREASE IN LOW LEVEL RH THIS AFTERNOON WHICH SHOULD BRING A BIT OF
CLOUD COVER ON THE CUMBERLAND SO INCLUDED THIS INTO THE SKY GRIDS.
IN THE LONG TERM...THE FOCUS RESIDES ON THE UPCOMING FRONTAL PASSAGE
THAT IS PROGGED TO REACH MIDDLE TN BY TUESDAY AFTERNOON AS INDICATED
BY THE GFS OR EVENING PER THE ECMWF. LATEST MODEL RUNS ARE REALLY
LACKING APPRECIABLE INSTABILITY AND SHEAR. WHILE DYNAMICAL FORCING
WILL BE SUFFICIENT FOR RAIN WITH A LIGHTNING STRIKE OR TWO...THE
CONFIDENCE IN WIDESPREAD TSRA IS LOW. FORECAST SOUNDINGS...WHILE
VERY MOIST...SHOW NEARLY ZERO CAPE AND EVEN SOME CIN IN PLACE DURING
PEAK HEATING TUESDAY. LOOKS LIKE LIFT WILL BE MOSTLY DYNAMICAL AND
EVEN THAT COULD BE BETTER AS 500 MB WINDS ARE ONLY IN THE 35-40 KT
RANGE. FEEL PREVIOUS FORECAST WAS PRETTY GOOD FOR POP CHANCES AND
OTHER THAN FINE TUNING SOME TIMING AND WX WORDING...NOT MUCH WAS
CHANGED. FEEL LIKE THIS WILL BE A MODERATE TO HEAVY RAINER AND NOT
MUCH ELSE.
BEYOND THIS FRONTAL SYSTEM...A TRANSITION PERIOD OF WEAK RIDGING
PRIOR TO THE NEXT SIGNIFICANT FRONTAL PASSAGE. AS FAR AS THE MODEL
COMPARISON GOES...THE DEPICTION OF THE 500 MB LOW IS QUITE DIFFERENT
IN BOTH TIMING AND CHARACTER. GFS DEPICTION ISNT QUITE AS DEEP WITH
THE HEIGHT FALLS...HOW FAR SOUTH THE LOW DIPS...OR AS SIGNIFICANT IN
THE POSITIVE TILT. THE ECMWF SOLUTION WOULD BE AN EYE OPENER FOR
STORM POSSIBILITIES AS IT GENERATES A HEALTHY PRE FRONTAL
TROUGH...NEAR 60 SFC DEWPOINTS AND A PROGGED 55 KT 850 MB JET. THE
ONLY REAL AGREEMENT IS THAT THE FRONT WILL EVENTUALLY PASS THROUGH
SOMETIME AROUND 12Z SATURDAY...GIVE OR TAKE 6 HOURS...AND IT WILL
PRODUCE RAIN. BECAUSE OF THIS...THATS WHAT WAS INCLUDED IN THE
GRIDS.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
18
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
626 AM CST FRI NOV 30 2012
.UPDATE...FOR 12Z AVIATION FORECAST
&&
.AVIATION...
STRATOCUMULUS ARE MOVING NORTH FROM ALABAMA BASED AROUND 25 HNDRD
FEET MSL. THESE CLOUDS APPEAR TO BE RIDING ALONG THE 290 KELVIN
SURFACE ON A SOUTHWESTERLY 30 KNOT LOW LEVEL JET. EXPECT THESE
CLOUDS TO BE AROUND THROUGH 14Z-15Z TIME FRAME OR UNTIL MIXING CAN
GET UNDERWAY...THEN THEY SHOULD THIN OUT. OTHERWISE LOOK FOR VFR
CONDITIONS TO PREVAIL THROUGH THE NEXT 24 HOURS WITH WINDS BECOMING
GUSTY DURING THE DAY AS SURFACE PRESSURE GRADIENT TIGHTENS A BIT
FROM CAROLINA HIGH PRESSURE CENTER TO OUR EAST AND CENTRAL PLAINS
LOW. EXPECT WIND GUSTS TO 18 KNOTS DURING THE DAY WITH WINDS
SUBSIDING BY EARLY EVENING.
BOYD
&&
.PREV DISCUSSION... /ISSUED 350 AM CST FRI NOV 30 2012/
DISCUSSION...
IN THE SHORT TERM...NOT MUCH TO SPEAK OF OTHER THAN SEEING IF
IMPROVEMENTS COULD BE MADE ON THE GFS TEMP INITIALIZATION. TRENDED A
BIT ABOVE THE GUIDANCE AS IT HAS BEEN TRENDING TOWARDS BEING TOO COOL
AS OF LATE. ALSO TWEAKED THE FIRST PERIOD SKY GRIDS TO INCLUDE THE
CIRRUS SEEN ON IR SATELLITE. NAM AND RUC LAYER RH SHOWS SOME
INCREASE IN LOW LEVEL RH THIS AFTERNOON WHICH SHOULD BRING A BIT OF
CLOUD COVER ON THE CUMBERLAND SO INCLUDED THIS INTO THE SKY GRIDS.
IN THE LONG TERM...THE FOCUS RESIDES ON THE UPCOMING FRONTAL PASSAGE
THAT IS PROGGED TO REACH MIDDLE TN BY TUESDAY AFTERNOON AS INDICATED
BY THE GFS OR EVENING PER THE ECMWF. LATEST MODEL RUNS ARE REALLY
LACKING APPRECIABLE INSTABILITY AND SHEAR. WHILE DYNAMICAL FORCING
WILL BE SUFFICIENT FOR RAIN WITH A LIGHTNING STRIKE OR TWO...THE
CONFIDENCE IN WIDESPREAD TSRA IS LOW. FORECAST SOUNDINGS...WHILE
VERY MOIST...SHOW NEARLY ZERO CAPE AND EVEN SOME CIN IN PLACE DURING
PEAK HEATING TUESDAY. LOOKS LIKE LIFT WILL BE MOSTLY DYNAMICAL AND
EVEN THAT COULD BE BETTER AS 500 MB WINDS ARE ONLY IN THE 35-40 KT
RANGE. FEEL PREVIOUS FORECAST WAS PRETTY GOOD FOR POP CHANCES AND
OTHER THAN FINE TUNING SOME TIMING AND WX WORDING...NOT MUCH WAS
CHANGED. FEEL LIKE THIS WILL BE A MODERATE TO HEAVY RAINER AND NOT
MUCH ELSE.
BEYOND THIS FRONTAL SYSTEM...A TRANSITION PERIOD OF WEAK RIDGING
PRIOR TO THE NEXT SIGNIFICANT FRONTAL PASSAGE. AS FAR AS THE MODEL
COMPARISON GOES...THE DEPICTION OF THE 500 MB LOW IS QUITE DIFFERENT
IN BOTH TIMING AND CHARACTER. GFS DEPICTION ISNT QUITE AS DEEP WITH
THE HEIGHT FALLS...HOW FAR SOUTH THE LOW DIPS...OR AS SIGNIFICANT IN
THE POSITIVE TILT. THE ECMWF SOLUTION WOULD BE AN EYE OPENER FOR
STORM POSSIBILITIES AS IT GENERATES A HEALTHY PRE FRONTAL
TROUGH...NEAR 60 SFC DEWPOINTS AND A PROGGED 55 KT 850 MB JET. THE
ONLY REAL AGREEMENT IS THAT THE FRONT WILL EVENTUALLY PASS THROUGH
SOMETIME AROUND 12Z SATURDAY...GIVE OR TAKE 6 HOURS...AND IT WILL
PRODUCE RAIN. BECAUSE OF THIS...THATS WHAT WAS INCLUDED IN THE
GRIDS.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
01
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
553 AM CST FRI NOV 30 2012
.UPDATE...
ADJUSTED FIRST FEW HOURS OF FIRST PERIOD TEMPERATURES TO ACCOUNT
FOR STOUT LOW LEVEL INVERSION THIS MORNING. ELEVATED AREAS ARE
SEEING LOW 40S WHERE LOW LYING AREAS ARE FALLING TO THE UPPER
20S. BLENDED THESE TEMPERATURES INTO GENERAL DIURNAL WARMING
TRENDS.
&&
.PREV DISCUSSION... /ISSUED 350 AM CST FRI NOV 30 2012/
DISCUSSION...
IN THE SHORT TERM...NOT MUCH TO SPEAK OF OTHER THAN SEEING IF
IMPROVEMENTS COULD BE MADE ON THE GFS TEMP INITIALIZATION. TRENDED A
BIT ABOVE THE GUIDANCE AS IT HAS BEEN TRENDING TOWARDS BEING TOO COOL
AS OF LATE. ALSO TWEAKED THE FIRST PERIOD SKY GRIDS TO INCLUDE THE
CIRRUS SEEN ON IR SATELLITE. NAM AND RUC LAYER RH SHOWS SOME
INCREASE IN LOW LEVEL RH THIS AFTERNOON WHICH SHOULD BRING A BIT OF
CLOUD COVER ON THE CUMBERLAND SO INCLUDED THIS INTO THE SKY GRIDS.
IN THE LONG TERM...THE FOCUS RESIDES ON THE UPCOMING FRONTAL PASSAGE
THAT IS PROGGED TO REACH MIDDLE TN BY TUESDAY AFTERNOON AS INDICATED
BY THE GFS OR EVENING PER THE ECMWF. LATEST MODEL RUNS ARE REALLY
LACKING APPRECIABLE INSTABILITY AND SHEAR. WHILE DYNAMICAL FORCING
WILL BE SUFFICIENT FOR RAIN WITH A LIGHTNING STRIKE OR TWO...THE
CONFIDENCE IN WIDESPREAD TSRA IS LOW. FORECAST SOUNDINGS...WHILE
VERY MOIST...SHOW NEARLY ZERO CAPE AND EVEN SOME CIN IN PLACE DURING
PEAK HEATING TUESDAY. LOOKS LIKE LIFT WILL BE MOSTLY DYNAMICAL AND
EVEN THAT COULD BE BETTER AS 500 MB WINDS ARE ONLY IN THE 35-40 KT
RANGE. FEEL PREVIOUS FORECAST WAS PRETTY GOOD FOR POP CHANCES AND
OTHER THAN FINE TUNING SOME TIMING AND WX WORDING...NOT MUCH WAS
CHANGED. FEEL LIKE THIS WILL BE A MODERATE TO HEAVY RAINER AND NOT
MUCH ELSE.
BEYOND THIS FRONTAL SYSTEM...A TRANSITION PERIOD OF WEAK RIDGING
PRIOR TO THE NEXT SIGNIFICANT FRONTAL PASSAGE. AS FAR AS THE MODEL
COMPARISON GOES...THE DEPICTION OF THE 500 MB LOW IS QUITE DIFFERENT
IN BOTH TIMING AND CHARACTER. GFS DEPICTION ISNT QUITE AS DEEP WITH
THE HEIGHT FALLS...HOW FAR SOUTH THE LOW DIPS...OR AS SIGNIFICANT IN
THE POSITIVE TILT. THE ECMWF SOLUTION WOULD BE AN EYE OPENER FOR
STORM POSSIBILITIES AS IT GENERATES A HEALTHY PRE FRONTAL
TROUGH...NEAR 60 SFC DEWPOINTS AND A PROGGED 55 KT 850 MB JET. THE
ONLY REAL AGREEMENT IS THAT THE FRONT WILL EVENTUALLY PASS THROUGH
SOMETIME AROUND 12Z SATURDAY...GIVE OR TAKE 6 HOURS...AND IT WILL
PRODUCE RAIN. BECAUSE OF THIS...THATS WHAT WAS INCLUDED IN THE
GRIDS.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
TB12
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
350 AM CST FRI NOV 30 2012
.DISCUSSION...
IN THE SHORT TERM...NOT MUCH TO SPEAK OF OTHER THAN SEEING IF
IMPROVEMENTS COULD BE MADE ON THE GFS TEMP INITIALIZATION. TRENDED A
BIT ABOVE THE GUIDANCE AS IT HAS BEEN TRENDING TOWARDS BEING TOO COOL
AS OF LATE. ALSO TWEAKED THE FIRST PERIOD SKY GRIDS TO INCLUDE THE
CIRRUS SEEN ON IR SATELLITE. NAM AND RUC LAYER RH SHOWS SOME
INCREASE IN LOW LEVEL RH THIS AFTERNOON WHICH SHOULD BRING A BIT OF
CLOUD COVER ON THE CUMBERLAND SO INCLUDED THIS INTO THE SKY GRIDS.
IN THE LONG TERM...THE FOCUS RESIDES ON THE UPCOMING FRONTAL PASSAGE
THAT IS PROGGED TO REACH MIDDLE TN BY TUESDAY AFTERNOON AS INDICATED
BY THE GFS OR EVENING PER THE ECMWF. LATEST MODEL RUNS ARE REALLY
LACKING APPRECIABLE INSTABILITY AND SHEAR. WHILE DYNAMICAL FORCING
WILL BE SUFFICIENT FOR RAIN WITH A LIGHTNING STRIKE OR TWO...THE
CONFIDENCE IN WIDESPREAD TSRA IS LOW. FORECAST SOUNDINGS...WHILE
VERY MOIST...SHOW NEARLY ZERO CAPE AND EVEN SOME CIN IN PLACE DURING
PEAK HEATING TUESDAY. LOOKS LIKE LIFT WILL BE MOSTLY DYNAMICAL AND
EVEN THAT COULD BE BETTER AS 500 MB WINDS ARE ONLY IN THE 35-40 KT
RANGE. FEEL PREVIOUS FORECAST WAS PRETTY GOOD FOR POP CHANCES AND
OTHER THAN FINE TUNING SOME TIMING AND WX WORDING...NOT MUCH WAS
CHANGED. FEEL LIKE THIS WILL BE A MODERATE TO HEAVY RAINER AND NOT
MUCH ELSE.
BEYOND THIS FRONTAL SYSTEM...A TRANSITION PERIOD OF WEAK RIDGING
PRIOR TO THE NEXT SIGNIFICANT FRONTAL PASSAGE. AS FAR AS THE MODEL
COMPARISON GOES...THE DEPICTION OF THE 500 MB LOW IS QUITE DIFFERENT
IN BOTH TIMING AND CHARACTER. GFS DEPICTION ISNT QUITE AS DEEP WITH
THE HEIGHT FALLS...HOW FAR SOUTH THE LOW DIPS...OR AS SIGNIFICANT IN
THE POSITIVE TILT. THE ECMWF SOLUTION WOULD BE AN EYE OPENER FOR
STORM POSSIBILITIES AS IT GENERATES A HEALTHY PRE FRONTAL
TROUGH...NEAR 60 SFC DEWPOINTS AND A PROGGED 55 KT 850 MB JET. THE
ONLY REAL AGREEMENT IS THAT THE FRONT WILL EVENTUALLY PASS THROUGH
SOMETIME AROUND 12Z SATURDAY...GIVE OR TAKE 6 HOURS...AND IT WILL
PRODUCE RAIN. BECAUSE OF THIS...THATS WHAT WAS INCLUDED IN THE
GRIDS.
&&
.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE 63 44 65 49 / 0 0 05 10
CLARKSVILLE 61 43 65 51 / 0 05 05 20
CROSSVILLE 56 43 60 45 / 0 0 05 10
COLUMBIA 63 44 66 49 / 0 0 05 10
LAWRENCEBURG 62 44 67 48 / 0 0 05 10
WAVERLY 62 43 66 51 / 0 05 05 10
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
TB12
FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION
VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
916 PM CST SAT DEC 1 2012
.UPDATE...
SUBSIDENCE BEHIND INITIAL WAVE THAT BROUGHT EARLIER
SHOWERS/ISOLATED THUNDERSTORMS HAS MIXED DOWN SOME STRONGER WIND
GUSTS OVER SOUTHEAST WISCONSIN THAT HAVE SCOURED OUT THE LIGHT FOG
AND BRIEFLY SCATTERED OUT THE LOW CLOUDS. NEXT WAVE APPROACHING
FROM EASTERN MN...WITH WEAK BUT PERSISTENT LIFT AND NEAR-SATURATED
CONDENSATION PRESSURE DEFICITS ON LATEST NAM AND RAP 290K
ISENTROPIC SURFACES INDICATE THE LOW CLOUDS TO THE WEST WILL MOVE
BACK INTO THE SOUTHEAST.
CHANCE POPS WILL ALSO BE KEPT AS LATEST NAM IS KEEPING PREVIOUS
TREND OF STRENGTHENING LOW-LEVEL FRONTOGENETIC RESPONSE AHEAD OF
SURFACE TROUGH THROUGH 06Z...THEN WEAKENING AS IT SHIFTS EAST
OVERNIGHT...IS BEING CONFIRMED BY SCATTERED LIGHT SHOWERS
DEVELOPING FROM SRN FOND DU LAC COUNTY TO ROCK COUNTY AND ANOTHER
LINE IN NW IL.
ADJUSTED TEMPERATURES AND DEW POINTS TO ACCOUNT FOR THE RISING
TEMPS THE PAST FEW HOURS...EXPECTING TEMPS TO PLATEAU THROUGH 06Z
TO 07Z...THEN ONLY FALL 4 TO 5 DEGREES THROUGH 12Z.
&&
.AVIATION/06Z TAFS/...
STRONGER WINDS MIXING DOWN WITH SUBSIDENCE BEHIND SHORT WAVE
TROUGH THAT BROUGHT EARLIER BAND OF SHOWERS AND ISOLATED
THUNDERSTORMS BRINGING A BRIEF BREAK IN THE IFR CONDITIONS TO MVFR...AND
ISOLATED VFR IN THE EAST. EXPECT AT LEAST MVFR EVERYWHERE...THEN
IFR CONDITIONS TO RETURN BY 06Z-07Z....WITH ISOLATED TO SCATTERED
LIGHT RAIN SHOWERS THROUGH 09Z AT EASTERN TAF SITES.
SOUNDINGS AND LATEST MET MOS DATA ARE PESSIMISTIC...KEEPING IFR
CIGS OVER ALL TAF SITES UNTIL AROUND 18Z SUNDAY AT KMSN...AND 20Z
TO 21Z AT EASTERN SITES.
&&
.MARINE...
KEEPING SMALL CRAFT ADVISORY GOING UNTIL EXPIRATION. THOUGH WINDS
HAVE SPIKED EXPECT THE SOUTH-SOUTHWEST WINDS TO TURN SOUTHWEST AND SLOWLY
DECREASE BETWEEN NOW AND 06Z TO 07Z AS THE SURFACE TROUGH MOVES
INTO THE NEARSHORE AREA. THE REDUCED SPEEDS AND OFFSHORE FLOW
SHOULD BE ENOUGH FOR WAVES TO FALL BELOW CRITERIA BY 09Z TO 10Z.
&&
.PREV DISCUSSION... /ISSUED 350 PM CDT SAT DEC 1 2012/
VERY SHORT TERM...TONIGHT AND SUNDAY.
AREA OF STRONG ISENTROPIC LIFT IN SOUTHWEST WI AT 18Z IS SHIFTING
ENE THIS AFTERNOON. THE NAM 290K PRESSURE ADVECTION PLOT SHOWS THIS
AREA WELL...AND BRINGS IT TO MILWAUKEE AROUND 22Z. THIS AREA IS ALSO
DEPICTED ON RADAR BY AN AREA OF SHOWERS OVER CENTRAL PORTIONS OF THE
FORECAST AREA EARLY THIS AFTERNOON. THEY ARE SPREADING EAST QUICKLY.
IT IS POSSIBLE THAT THE FEW HIGHER RETURNS ON THE RADAR HAVE SOME
THUNDER...AS RAP AND NAM SOUNDINGS SHOW WEAK ELEVATED CAPE ABOVE
5000 FEET.
THE ISENTROPIC LIFT COINCIDES WITH WEAK VORTICITY ADVECTION
ASSOCIATED WITH A MID LEVEL SHORTWAVE...850/700MB MOISTURE
CONVERGENCE...AND WEAK UPPER DIVERGENCE TO SUPPORT LIGHT RAIN LATE
THIS AFTERNOON THROUGH THE FIRST HALF OF THE EVENING...ESPECIALLY IN
SOUTHEAST WI. THEN THE MOISTURE AND PRESSURE ADVECTION WILL LINGER
ACROSS THE SOUTHEAST HALF OF WI THROUGH AROUND MIDNIGHT...UNTIL THE
NEXT WEAK 500MB SHORTWAVE SWEEPS THROUGH AND KICKS OUT THE SURFACE
TROUGH.
RAIN SHOWERS SHOULD KEEP REGENERATING THROUGH THE EVENING IN THE
SOUTHEAST...BUT THERE IS A GOOD CHANCE THAT THE RAIN WEST OF MADISON
IS DONE AND ONLY DRIZZLE AND FOG WILL BE THE CONCERN THE REST OF THE
EVENING.
THERE IS SOME CONCERN FOR DENSE FOG TO DEVELOP THIS EVENING IN SOUTH
CENTRAL WI WHILE WAITING FOR THAT NEXT SHORTWAVE...AND ALSO LATE
TONIGHT JUST BEHIND THE SURFACE TROUGH...ESPECIALLY AROUND SUNRISE
TIME. FAR SOUTHEAST WI WILL HAVE THE LIMITING FACTOR OF BRISK WEST
WINDS JUST ABOVE THE SURFACE. THE WESTERN FORECAST AREA INCLUDING
MADISON LOOKS LIKE IT HAS THE BEST CHANCE OF DENSE FOG OVERNIGHT.
NOT QUITE CONFIDENT ENOUGH AT THIS TIME TO ISSUE ANY HEADLINES
THOUGH.
DEWPOINT TEMPS SHOULD ONLY DROP A COUPLE OF DEGREES BEHIND THIS COLD
FRONT BY SUNDAY MORNING. DRIER AIR WILL MOVE IN ALOFT WITH MID LEVEL
RIDGING. EXPECTING SUNSHINE TO BEGIN SPREADING INTO SOUTHERN WI BY
MID SUNDAY MORNING AND ACROSS THE WHOLE AREA BY SUNDAY AFTERNOON.
THIS SHOULD ALLOW HIGHS TO CREEP INTO THE UPPER 50S FAR SOUTH.
SHORT TERM...SUNDAY NIGHT THROUGH TUESDAY.
WEAK FRONTAL BOUNDARY EXPECTED TO SLOG THROUGH SOUTHERN WI LATER
TONIGHT AND SUNDAY AND WILL BECOME NEARLY STATIONARY ACROSS
NORTHERN/CENTRAL IL BY SUNDAY EVENING. INCREASING SOUTHERLY LOW
LEVEL WINDS LATER SUNDAY NIGHT AND MONDAY WILL CARRY WARM FRONT
RAPIDLY NORTHWARD. INITIALLY CLEAR SKIES...LIGHT WINDS AND DEWPTS IN
THE LOW TO MID 40S WILL ALLOW PATCHY FOG TO DEVELOP SUNDAY EVENING.
NOT EXPECTING VISIBILITIES TO GET TO LOW HOWEVER AS BOUNDARY LAYER
MIXING INCREASES AFTER MIDNIGHT.
QUITE A BIT OF CLOUDINESS EXPECTED ON MONDAY...EVEN AFTER WARM FRONT
PASSES TO THE NORTH. CLOUDS AND BREEZY SOUTH WINDS SHOULD KEEP
DAYTIME TEMPERATURES FROM GETTING TOO WARM...HOWEVER WITH 925H TEMPS
RISING TO AROUND 13C...WILL BE FLIRTING WITH RECORD HIGHS FOR 3 DEC.
RECORDS MOSTLY IN THE 60 TO 65 DEGREE RANGE.
PREFER SLOWER MOVEMENT OF SURFACE FRONT FROM MORE CONSISTENT ECMWF
AND NAM SOLUTIONS. HENCE MORE TIME FOR RETURN OF DEEPER COLUMN
MOISTURE AS PWAT VALUES RETURN TO AROUND THREE QUARTERS INCH. SHORT
TERM GUIDANCE IN AGREEMENT ON CARRYING LOW LEVEL FRONTOGENETICAL
FORCING ACROSS SRN WI DURING THE AFTN AND EARLY EVENING. HENCE WL
KEEP LIKELY POPS GOING AND ADD LIKELY WORDING TO EAST IN THE
EVENING. SOUNDINGS SHOWING SOME ELEVATED INSTABILITY...HOWEVER
ELEVATED CIN REMAINS AROUND OR HIGHER THAN 50 J/KG. WL HOLD OFF ON
INTRODUCING ISOLD T FOR NOW.
DRIER...COOLER AIR SWEEPS IN MONDAY NIGHT BUT COLDEST AIR REMAINS TO
THE NORTH. COLDEST AIR REMAINS TO THE NORTH...AND ONLY GLANCES
ACROSS SOUTHERN WI TUESDAY AFTERNOON AND EVE. LOW LEVELS REMAIN DRY
SO NO PRECIP EXPECTED WITH THIS SECONDARY CDFNT.
LONG TERM...TUESDAY NIGHT THROUGH SATURDAY.
SOUTHERN WI RECEIVES GLANCING BLOW FROM SURGE OF COLDER AIR
ASSOCIATED WITH SECONDARY FRONT TUESDAY NIGHT. LIGHT WINDS AND
COLDER AIR SHOULD RESULT IN TEMPS DROPPING TO AROUND SEASONAL
NORMALS TUESDAY NIGHT. THERMAL TROUGH QUICKLY PUSHES OFF TO THE EAST
ON WEDNESDAY AS LOW TO MID LEVEL RIDGING MOVES ACROSS THE REGION.
WARM AIR ADVECTION AHEAD OF NEXT SHORT WAVE ENERGY DEVELOPS ON
WEDNESDAY WITH STRONG LOW LEVEL WINDS AND INCREASING MOISTURE WED
NGT INTO THURSDAY. ENOUGH INCREASING COLUMN MOISTURE WITH PWAT
VALUES CLIMBING TO AROUND THREE QUARTERS INCH TO WARRANT SMALL POPS
FOR LIGHT PRECIP IN PARTS OF THE AREA WEDNESDAY NIGHT INTO THURSDAY
MORNING. LATEST DETERMINISTIC RUNS OF ECMWF AND GFS INCREASES
FORWARD SPEED OF PIECE OF SHORT WAVE ENERGY MOVING THROUGH THE
WESTERLIES. MAIN SYNOPTIC FORCING WITH THIS FEATURE NOW EXPECTED TO
AFFECT SRN WI ON THU/THU EVE...SO WL CONTINUE TO BUMP UP POPS ACROSS
THE CWA DURING THIS PERIOD.
PROGRESSIVE FLOW WILL CARRY THIS FEATURE TO THE EAST LATER THU NIGHT
AS COLDER...DRIER AIR SETTLES INTO THE REGION FOR FRIDAY. GEM...
ECMWF AND UKMT HINTING AT UPSTREAM RIDGING TAKING ON HIGHER
AMPLITUDE LATE IN THE WEEK WITH MORE W-NW FLOW CARRYING COLDER AIR
INTO THE REGION AND LINGERING THRU THE WEEKEND. ALTHOUGH LATEST
DETERMINISTIC GFS NOT AS COLD...GFS 5 DAY 500H ANOMOLIES CONTINUE TO
SHOW BROADSCALE TROFING SETTLING OVER THE UPPER MIDWEST BY THE
WEEKEND WITH NEGATIVE ANOMOLIES OF 75-100M OVER WI BY AROUND 00Z/12.
MAJORITY OF GFS ENSEMBLE MEMBERS AT MID-UPPER LEVELS ALSO FAVOR
COLDER SCENARIO. THIS WOULD RESULT IN MORE PERSISTENT SEASONAL TEMPS
FOR THE SECOND FULL WEEK OF DEC.
AVIATION /00Z TAFS/...
A WARM FRONT IS PUSHING THROUGH SOUTHERN WISCONSIN THIS AFTERNOON AS
LOW PRESSURE TRACKS ACROSS NORTHERN MINNESOTA TO JUST NORTH OF LAKE
SUPERIOR. LIGHT RAIN IS SPREADING ACROSS SOUTHERN WI WITH A SURGE OF
MOISTURE PUSHING INTO THE AREA. LIGHT RAIN SHOWERS SHOULD KEEP
REGENERATING IN SOUTHEAST WI...BUT ONLY EXPECTING DRIZZLE WEST OF
MADISON THE REST OF THE EVENING.
EXPECT LINGERING IFR/LIFR LOW CLOUDS...FOG AND DRIZZLE THROUGH MID
SUNDAY MORNING BEFORE THE DRIER AIR AND HIGH PRESSURE CAN TAKE OVER.
THERE IS A CHANCE FOR DENSE FOG FOR A PERIOD OF TIME LATE
TONIGHT/EARLY SUN MORNING JUST AFTER THE LOW PRESSURE TROUGH PASSES
THROUGH...ESPECIALLY NEAR MADISON AND WEST.
MARINE...
SOUTH WINDS SHOULD GUST TO AROUND 25 KNOTS THROUGH AROUND
MIDNIGHT...THEN DIMINISH AS THEY VEER TO THE WEST BEHIND A PASSING
COLD FRONT/SURFACE LOW PRESSURE TROUGH.
PERSISTENT SOUTH WINDS ARE BUILDING HIGH WAVES. SMALL CRAFT ADVISORY
IN EFFECT THROUGH 10Z TONIGHT. WAVES WILL SUBSIDE AFTER MIDNIGHT
WITH THE OFFSHORE DIMINISHING WINDS.
SMALL CRAFT ADVISORY CONDITIONS WILL LIKELY BE MET ONCE AGAIN MONDAY
WITH SOUTH WINDS AHEAD OF A STRONGER LOW PRESSURE SYSTEM.
CONFIDENCE...
TONIGHT AND SUNDAY...LOW TO MEDIUM.
SUNDAY NIGHT...MEDIUM.
MONDAY AND MONDAY NIGHT...MEDIUM.
TUESDAY AND TUESDAY NIGHT...MEDIUM TO HIGH.
WEDNESDAY THROUGH THURSDAY...LOW TO MEDIUM.
FRIDAY AND SATURDAY...MEDIUM.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 4 AM CST SUNDAY FOR LMZ643>646.
&&
$$
UPDATE...REM
TONIGHT/SUNDAY AND AVIATION/MARINE...MRC
SUNDAY NIGHT THROUGH SATURDAY...MBK
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...TONIGHT AND SUNDAY
546 PM CST SAT DEC 1 2012
A TRICKY FORECAST EXISTS FOR BOTH TAF SITES...ESPECIALLY FOR
VISIBILITIES. AT 23Z...A COLD FRONT STRETCHED FROM MINNEAPOLIS TO
OMAHA...WITH CLEARING BEHIND IT. AHEAD OF THE FRONT...AN
UNSEASONABLY MOIST AIRMASS HAS LED TO LIFR CEILINGS/VISIBILITIES AT
KRST AND IFR CEILINGS/VISIBILITIES AT KLSE. THE FRONT SHOULD CLEAR
KRST BY 04Z...ALLOWING FOR IMPROVEMENT TO AT VFR FOR CEILINGS AND
AT LEAST MVFR VISIBILITIES. THE FRONT WILL LIKELY GO THROUGH KLSE
AROUND 06Z...BUT ANTICIPATING THE MOISTURE TO GET STUCK IN THE
MISSISSIPPI RIVER VALLEY. AS A RESULT...HAVE CEILINGS STAYING AT
LIFR AT KLSE THROUGH MUCH OF THE MORNING. VISIBILITIES AT KLSE
COULD EVEN FALL TO LIFR OR LOWER DUE TO NIGHTTIME COOLING AS THE
LATE NIGHT APPROACHES. KRST IS INTERESTING AS WELL AS THE WINDS
LOOK TO DIMINISH LATE TONIGHT. WITH THE MOISTURE NOT DECREASING
QUICKLY BEHIND THE FRONT...CONCERN IS THAT BR/FOG AND PERHAPS
EVEN LOW CLOUDS MAY REDEVELOP. HAVE INCLUDED IFR BR DEVELOPING AT
08Z BUT IT IS POSSIBLE DENSE FOG DEVELOPS. BOTH SITES SHOULD SEE
IMPROVEMENT TO VFR AROUND NOON IN BOTH CEILINGS AND
VISIBILITIES...RESULTING FROM DAYTIME MIXING. HOWEVER...THERE IS
UNCERTAINTY AT KLSE THAT CLOUDS COULD GET STUCK IN THE VALLEY ALL
DAY SUNDAY DUE TO LIGHT WINDS. THIS WILL NEED TO BE WATCHED.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
841 PM CST SAT DEC 1 2012
WI...DENSE FOG ADVISORY UNTIL 9 AM CST SUNDAY FOR WIZ017-029.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
316 AM EST SUN DEC 2 2012
.DISCUSSION...
TODAY...
DEEP/PERSISTENT E/NERLY FLOW ACRS CENTRAL FL WILL BE MAINTAINED BY A
STUBBORN HIGH PRES RIDGE EXTENDING FROM THE NC OUTER BANKS TO THE
WRN GOMEX. LATEST RAP ANALYSIS SHOWS PLENTY OF LOW LVL MOISTURE
UPSTREAM...A FINGER OF H100-H70 MOISTURE NOTED JUST E OF THE BAHAMA
BANK WITH MEAN RH VALUES BTWN 70-80PCT.
EMBEDDED WITHIN THE DEEP ERLY FLOW...THIS MOISTURE WILL PUSH INTO
THE FL PENINSULA AFT DAYBREAK AND SHOULD PROVIDE THE FUEL NECESSARY
FOR ISOLD/SCT SHRAS FOR MOST OF THE CWA. COVERAGE HIGHEST ALONG THE
COAST S OF CAPE CANAVERAL GIVEN THE RAP MOISTURE PROFILE. IMPACT
WILL BE LOW...HOWEVER...AS THE RIDGE AXIS MAINTAINS A SHARP
SUBSIDENCE INVERSION IN THE H85-H70 LYR. THIS WILL LIMIT VERTICAL
MOTION BLO 10KFT...QPF BLO 0.10" AREAWIDE. NO CHANGE IN THE SOURCE
REGION...LITTLE CHANGE IN TEMP DISTRIBUTION FROM SAT. ONSHORE FLOW
WILL KEEP MAX TEMPS A FEW DEGS COOLER ALONG THE COAST...BUT AFTN
READINGS WILL BE BTWN 75-80F AREAWIDE.
TONIGHT...
THE RIDGE AXIS WILL DRIFT SWD AS A STORM SYSTEM MOVING OUT OF THE
NRN ROCKIES RIDES UP ITS BACKSIDE. THE ERLY FLOW WILL DIMINISH AS A
RESULT BUT SHOULD HOLD UP ENOUGH TO PREVENT DECOUPLING. MIN TEMPS IN
THE M/U50S INTERIOR...L/M60S ALONG THE COAST.
SLIGHTLY DRIER AIR NOTED BEHIND THE AFOREMENTIONED MOISTURE POCKET
WITH H100-H70 MEAN RH VALUES FALLING BLO 70PCT. DIFFICULT TO SQUEEZE
MEASURABLE PRECIP OUT OF SUCH AN AIRMASS OUTSIDE OF THE GULF STREAM.
WILL KEEP PRECIP OUT OF THE FCST...KEEPING A SILENT 10PCT FOR THE
COASTAL COUNTIES.
MON-TUE...SURFACE HIGH PRESSURE RIDGE AXIS WILL CONTINUE VICINITY
GEORGIA AND NORTH FLORIDA. THIS WILL MAINTAIN AN ONSHORE WIND FLOW...
THOUGH IT WILL BE A LITTLE WEAKER AS THE LOCAL PRESSURE GRADIENT
SLOWLY EASES. THIS ONSHORE FLOW WILL TAP SUBSIDENT/DRIER AIR OVER
THE ATLANTIC SO EXPECT NEGLIGIBLE POPS MON. THE GFS SHOWS LIGHT
PRECIP OVER THE ATLANTIC ON TUE BUT MOS POPS ARE ONLY 5 PERCENT SO
WILL MAINTAIN A DRY FORECAST. MILD TEMPS WITH HIGHS MOSTLY IN THE
UPPER 70S AND LOWS IN THE MID-UPPER 50S INLAND AND LOWER 60S ALONG
THE COAST.
WED-SUN...THE HIGH PRESSURE RIDGE WILL BREAK DOWN ON WED AS A
FRONTAL BOUNDARY PUSHES OFFSHORE THE EASTERN SEABOARD WITH
TRAILING SOUTHERN PORTION HANGING UP TO OUR NORTH. SOUTHERN
PORTION OF A SHORTWAVE TROUGH IS PROGGED TO CROSS THE REGION WED
NIGHT BUT GFS CONTINUES TO SHOW THAT THE AVAILABLE MOISTURE WILL
BE LIMITED. THE ECMWF IS A LITTLE MORE MOIST...BUT STILL THE BULK
OF PRECIP IS INDICATED OVER THE ATLANTIC. THEREFORE...HAVE
MAINTAINED PREVIOUS FORECAST...WHICH CONFINES SMALL POPS TO THE
COASTAL WATERS.
STRONGER HIGH PRESSURE WILL REBUILD ALONG THE EASTERN SEABOARD THU
AND CAUSE ONSHORE FLOW TO INCREASE A LITTLE. THE FLOW IS PROGGED
TO WEAKEN BY NEXT WEEKEND AS THE RIDGE AXIS SHIFTS CLOSER TO THE
AREA. ANY RAIN CHANCES IN THIS PATTERN WILL BE SMALL. THE 00Z GFS
SHOWS SLIGHTLY HIGHER MOISTURE AND LIGHT QPF ON FRI SO HAVE
INCLUDED A SMALL POP FOR THE SOUTH HALF OF THE COAST. A LITTLE
MORE MOISTURE POOLING INDICATED SAT/SUN AHEAD OF A WEAK UPPER
LEVEL IMPULSE...BUT HAVE ONLY CARRIED A SMALL POP ALONG THE NORTH
HALF OF THE COAST ON SAT.
LITTLE CHANGE IN THE MILD TEMPERATURES IS INDICATED THROUGH THE
PERIOD.
&&
.AVIATION...
PREVAILING VFR ALL SITES THRU 03/12Z. THRU 02/14Z...AREAS CIGS BTWN
FL040-060...BRIEF ISOLD MVFR SHRAS E OF KOMN/KOBE. BTWN
02/14Z-03/00Z...OCNL ERLY SFC WND G18-23KTS...BRIEF SCT MVFR SHRAS S
OF KMLB-KOBE...ISOLD N OF KMLB-KOBE.
&&
.MARINE...
TODAY-TONIGHT...LATEST DATA BUOY/C-MAN OBS MEASURING WINDS/SEAS NEAR
OR AT SCA LVLS...WINDS GENERALLY 15-20KTS WITH SEAS 5-7FT...WINDS
SLIGHTLY WEAKER N OF CAPE CANAVERAL DUE TO WEAKER PGRAD. LITTLE
IMPROVEMENT THRU TONIGHT AS A HI PRES RIDGE EXTENDING FROM THE NC
OUTER BANKS TO THE WRN GOMEX MAINTAINS A FAIRLY TIGHT PGRAD ACRS THE
LCL ATLC. ROUGH SEAS AREAWIDE AS A 15-25KT E/NE FETCH BTWN BERMUDA
AND THE BAHAMA BANK PUSHES A MODERATE SWELL INTO THE E FL COAST.
WILL HOIST AN SCA FOR ALL LCL WATERS THRU SUNSET...SCALING BACK TO
THE OFFSHORE WATERS OVERNIGHT AS THE RIDGE SAGS SLOWLY SWD ALLOWING
THE PGRAD TO SLACKEN.
MON-THU...ONSHORE FLOW IS INDICATED THROUGH THE PERIOD WITH SPEEDS
MAINLY 10-15 KNOTS MON-TUE...5-10 KNOTS WED AND THEN PROBABLY
GETTING BACK TO 10-15 KNOTS THU. SEAS WILL BE SLOW TO DIMINISH
WITH SOME EXERCISE CAUTION STATEMENTS CONTINUING INTO MON.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 77 61 77 57 / 20 10 10 0
MCO 80 59 79 57 / 20 10 0 0
MLB 78 63 77 62 / 20 10 10 0
VRB 78 62 77 61 / 30 10 10 0
LEE 80 58 79 56 / 20 10 0 0
SFB 80 59 79 58 / 20 10 0 0
ORL 80 59 79 58 / 20 10 0 0
FPR 78 62 77 61 / 30 10 10 0
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR COASTAL
WATERS FROM FLAGLER BEACH TO VOLUSIA BREVARD COUNTY LINE
OUT 20 NM-COASTAL WATERS FROM SEBASTIAN INLET TO JUPITER
INLET OUT 20 NM-COASTAL WATERS FROM VOLUSIA BREVARD COUNTY
LINE TO SEBASTIAN INLET OUT 20 NM.
SMALL CRAFT ADVISORY UNTIL 7 AM EST MONDAY FOR WATERS FROM
FLAGLER BEACH TO VOLUSIA BREVARD COUNTY LINE 20 TO 60 NM
OFFSHORE-WATERS FROM SEBASTIAN INLET TO JUPITER INLET 20 TO
60 NM OFFSHORE-WATERS FROM VOLUSIA BREVARD COUNTY LINE TO
SEBASTIAN INLET 20 TO 60 NM OFFSHORE.
&&
$$
SHORT TERM/AVIATION...BRAGAW
LONG TERM....LASCODY
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 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
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 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.
&&
$$
BORGHOFF/MPG
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1015 PM CST SAT DEC 1 2012
.DISCUSSION...
DENSE FOG HAS EXPANDED DURING THE LATE EVENING HOURS...PROMPTING A
DENSE FOG ADVISORY FOR MUCH OF THE FORECAST AREA EXCEPT FOR THE
FAR SOUTH. THE ENTIRE ADVISORY EXPIRES AT 9 AM CST SUNDAY...AND
LATER SHIFTS CAN ADJUST AS NEEDED.
&&
.AVIATION...
LOW STRATUS REDEVELOPING IN THE MISSOURI RIVER VALLEY IS PROMPTING
AMENDMENTS KEEP IFR/LIFR CONDITIONS IN LONGER OVERNIGHT AT
KBIS/KISN. THE LATEST RAP HAS A GOOD HANDLE ON THE LOW LEVEL
MOISTURE AND WILL GENERALLY FOLLOW ITS SLOWER CLEARING FOR THE
NEXT TAF ISSUANCE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 9 AM CST SUNDAY FOR NDZ001>005-009>013-
017>023-025-035>037.
&&
$$
DISCUSSION/AVIATION...RK
AREA FORECAST DISCUSSION
NWS 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 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
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
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 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 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 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
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 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 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 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 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 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 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 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 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