Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 01/09/13
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
949 AM MST MON JAN 7 2013
.UPDATE...
&&
.SHORT TERM...CURRENT FORECASTS LOOK REASONABLE. CLOSED UPPER LOW
CURRENTLY OVER SOUTHERN CALIFORNIA WITH WEAK FLOW ALOFT ACROSS
COLORADO. HIGH CLOUDS OVER AREA CONTINUE TO THIN WHICH WILL ALLOW
FOR ABUNDANT SUNSHINE AND HELP WITH WARMUP DESPITE SLIGHTLY COOLER
AIRMASS OVER REGION. MAY NEED TO INCREASE TEMPS A BIT ACROSS THE
PLAINS...BASED ON CURRENT CONDITIONS.
.AVIATION...CURRENT TAF TRENDS STILL ON TRACK. LATEST RAP AND HRRR
INDICATE THE DEVELOPMENT OF A DENVER CYCLONE DURING THE AFTERNOON
WITH SOUTHEAST WINDS AT DEN AND APA...AND WEST TO NORTHWEST WINDS
AT BJC. SPEEDS STILL EXPECTED TO STAY BELOW 12 KTS. DRAINAGE
PATTERN TO DEVELOP THIS EVENING. VFR TO CONTINUE.
&&
.PREV DISCUSSION... /ISSUED 406 AM MST MON JAN 7 2013/
SHORT TERM...CLOSED UPPER LEVEL LOW OVER SOUTHERN CALIFORNIA WILL
DIVE SOUTHEAST INTO MEXICO TODAY. THE MAIN JET STREAM WILL BE OVER
THE NORTHERN ROCKIES AND LEAVE COLORADO IN BETWEEN THESE FEATURES
WHICH WILL RESULT IN A WEAK FLOW ALOFT. TEMPERATURES ARE RUNNING
MUCH WARMER THIS MORNING THAN THE PAST FEW DUE TO THE CLOUDS OVER
THE AREA. IN ADDITION TO THE HIGH CLOUDS...WEST WINDS OVER AND
NEAR THE FOOTHILLS ARE ALSO HELPING KEEP TEMPERATURES UP. THE HIGH
CLOUDS WILL MOVE OFF TO THE EAST THIS MORNING. EVEN THOUGH THE
AIRMASS ABOVE COLORADO WILL BE SLIGHTLY COOLER TODAY...A MUCH
WARMER START TO THE DAY AND SUNSHINE WILL ALLOW MOST LOCATIONS TO
GET CLOSE OR POSSIBLY A LITTLE WARMER THAN YESTERDAY.
THE JET STREAM OVER THE NORTHERN ROCKIES WILL SINK SOUTH SOME
TONIGHT AS A SHORT WAVE PASSES TO THE NORTH OF COLORADO. WILL SEE AN
INCREASE IN MID AND HIGH CLOUDS TONIGHT AS THIS OCCURS. THE CLOUD
COVER WILL BRING ANOTHER MILD NIGHT. MAY BE ABLE TO SQUEEZE OUT A
COUPLE OF WEAK SNOW SHOWERS OVER THE MOUNTAINS OF NORTH CENTRAL
COLORADO. IF ANY SNOW DEVELOPS...IT WILL BE LIGHT WITH ACCUMULATION
LESS THAN AN INCH.
LONG TERM...ABOVE AVERAGE TEMPERATURES AND AN ALMOST ZERO
CHANCE FOR PRECIP STILL PROGGED FOR THE TUESDAY-THURSDAY TIME
PERIOD. BROAD UPPER RIDGE SLOWLY MIGRATES OVER THE REGION DURING
THE 3-DAY PERIOD. MODERATE NORTHWEST FLOW ALOFT ON TUESDAY WILL
TRANSITION TO A LIGHTER WEST-SOUTHWEST FLOW ON WEDNESDAY AND A
MORE SOUTHWESTERLY FLOW OF SIMILAR SPEED ON THURSDAY. A CLOSED
UPPER LOW PASSING TO OUR SOUTHEAST ON THURSDAY COULD BRUSH
SOUTHEASTERN PORTIONS OF THE FORECAST AREA WITH A SHIELD OF
MID/HIGH LEVEL CLOUDS DURING THE MORNING HOURS...DON/T SEE ANY
PRECIP WITH THIS MOISTURE. SEE SMALL DAY-TO-DAY CHANGE IN
TEMPERATURE DURING THE PERIOD WITH TUESDAY THE COOLER OF THE 3
DAYS AND EITHER WEDNESDAY OR THURSDAY THE WARMEST DAY. ALL DEPENDS
ON HOW MUCH CLOUD COVER WE SEE ON THURSDAY.
ATTENTION NEXT TURNS TO THE DEEP UPPER TROUGH AND STRONG SFC COLD
FRONT SWINGING OUT OF THE PACIFIC NORTHWEST MIDWEEK. 00Z AND 06Z
RUNS OF THE OPERATIONAL GFS AND ECMWF APPEAR TO CLUSTER AROUND A
SIMILAR SOLUTION FOR WEDNESDAY AND THURSDAY...BUT THEN DIVERGE WITH
THE GFS BECOMING STRONGER...WETTER AND MORE PROGRESSIVE WITH THE
TROUGH THAN THE EC. MOISTURE AND WIND FIELDS OF THE 00Z/06Z CANADIAN
GEM APPEAR SIMILAR TO THOSE OF THE ECMWF...AND SIMILAR TO THE HEIGHT
AND TEMP FIELDS OF THE GFS. THE GFS INDICATES SFC CYCLOGENSIS IN
SERN COLORADO ON FRIDAY WITH A SFC COLD FRONT BACKING INTO NERN
COLORADO THAT MORNING AS A LARGE UPPER LEVEL TROUGH CARVES OUT OVER
THE ROCKY MTN REGION. THE EC AND GEM DELAY THE ARRIVAL OF THE COLD
FRONT UNTIL FRIDAY AFTERNOON AND THE REALLY COLD AIR UNTIL WELL
AFTER DARK. THIS WOULD EXPLAIN THE WIDE RANGE IN MAX TEMPERATURES
OFFERED BY THE VARIOUS MOS GUIDANCE. FOR INSTANCE...GFS MOS GIVES A
MAX TEMP OF 30 AT DENVER ON FRI AND THE ECMWF A MUCH WARMER HIGH OF
58. FOR SATURDAY...GFS GIVES A HIGH AT DENVER OF ONLY 20...AND THE
EC A HIGH OF 38. REALLY COULD GO EITHER WAY AT THIS POINT...BUT
SURROUNDING WFOS HAVE SIDED WITH THE COLDER GFS. WILL DO THE
SAME...AT LEAST FOR NOW.
THERE/S ALSO A SIGNIFICANT AMOUNT OF UNCERTAINTY WITH REGARD TO OUR
PRECIPITATION CHANCES WITH THIS SYSTEM. GFS WOULD HAVE US BELIEVE WE
COULD SEE SEVERAL INCHES OF SNOW BOTH MTNS AND PLAINS STARTING
FRIDAY AFTERNOON AND ENDING SATURDAY MORNING WITH SEVERAL HOURS OF
DEEP CYCLONIC UPSLOPE FLOW. WHEREAS EC AND GEM INDICATE LESS
OROGRAPHIC/SYNOPTIC SCALE FORCING AS WELL AS LESS LOW-LEVEL
MOISTURE. THEIR SNOW ACCUM GRIDS INDICATE ONLY SCATTERED AREAS OF
LIGHT SNOW ACCUMULATION BY SATURDAY MORNING. BOTTOM LINE...WITH SO
MUCH UNCERTAINTY IN FORECAST BEYOND THURSDAY NIGHT...NOT PLANNING TO
MAKE MANY CHANGES TO CURRENT FCST PACKAGE DURING THIS PERIOD.
AVIATION...VFR CONDITIONS WILL PREVAIL THE NEXT 24 HOURS WITH
HIGH CLOUDS THIS MORNING AND THEN AGAIN TONIGHT.
AT KDEN AND KAPA...NORMAL SOUTHERLY DRAINAGE WINDS WILL BECOME LIGHT
AND VARIABLE AFTER SUNRISE. BY AFTERNOON...EXPECTING SOME SORT OF
WEAK EASTERLY COMPONENT TO THE WIND...LIKELY EAST TO SOUTHEAST.
WINDS SPEEDS ARE EXPECTED TO STAY UNDER 12 KNOTS.
AT KBJC...WESTERLY WINDS WILL PREVAIL THROUGH EARLY MORNING. MAY SEE
WIND GUSTS AS HIGH AS 20 KNOTS AS WINDS ROLL OFF THE FOOTHILLS.
WEAKER WINDS ARE EXPECTED DURING THE DAY. THEN TONIGHT...WESTERLY
WINDS MAY INCREASE WITH GUSTS TO 25 KNOTS OCCASIONALLY OCCURRING.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...D-L
LONG TERM....BAKER
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
927 PM EST TUE JAN 8 2013
.SYNOPSIS...
HIGH PRESSURE TO OUR EAST TONIGHT WILL SLOWLY LESSENS ITS INFLUENCE
ON OUR REGION TOMORROW WHILE A WEAK COLD FRONT PUSHES THROUGH
WEDNESDAY NIGHT. A LOW PRESSURE SYSTEM THEN SLIDES THROUGH THE
REGION THURSDAY NIGHT INTO FRIDAY FOLLOWED BY WEAK HIGH PRESSURE
THROUGH SATURDAY. ANOTHER LOW PRESSURE SYSTEM WILL DROP A COLD FRONT
ACROSS OUR AREA LATE SUNDAY INTO MONDAY. HIGH PRESSURE THEN MOVES
BACK IN BEHIND THE DEPARTING SYSTEM.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
THE LOWER CLOUDS TRAPPED UNDER THE INVERSION CONTINUE TO MOVE
SLOWLY EAST ACROSS NORTHEAST MARYLAND...DELAWARE AND A PORTION OF
SOUTHERN NEW JERSEY. THE INVERSION DOES NOT SHOW UP WELL ON THE
0000 UTC KIAD SOUNDING (TOO FAR WEST TO SAMPLE THE MOISTURE
WELL)...THOUGH THE INVERSION IS THERE. THE 0000 UTC KWAL SHOWS THE
MOISTURE...BUT THE LOW LEVEL INVERSION IS HIGHER THERE.
THE LATEST RAP APPEARS TO HAVE A DECENT HANDLE ON THE MOISTURE
TRAPPED UNDER THE INVERSION...THOUGH IT MAY BE TOO QUICK TO WEAKEN
THE INVERSION AND ALLOW THE MOISTURE TO MIX OUT. THE TREND IS
FOLLOWED...BUT THE LOWER CLOUDS PROBABLY LINGER INTO THE EARLY
MORNING HOURS FOR THE SOUTHERN THIRD OF THE AREA. FURTHER NORTH...
MAINLY JET CIRRUS IN THE FAST WEST TO SOUTHWEST MID LEVEL FLOW.
THE COVERAGE HAS SHRUNK WITH TIME...BUT PATCHES OF CIRRUS SHOULD
AFFECT THE REGION OVERNIGHT.
WINDS DROPPED OFF AFTER SUNSET...AND TEMPERATURES CRATERED IN SOME
AREAS. THE CIRRUS MAY MITIGATE THIS TO SOME DEGREE OVERNIGHT...BUT
LOWS WERE DROPPED IN THE PROTECTED LOCATIONS FOR TONIGHT. ELSEWHERE...
JUST SOME TWEAKING OF HOUR TEMPERATURES WAS NEEDED. THE RADIATIONAL
COOLING COULD ALLOW PATCHY FOG TO FORM. USING THE CROSSOVER TEMPERATURE
METHOD...PORTIONS OF EASTERN PENNSYLVANIA AND NORTH CENTRAL NEW
JERSEY APPEAR TO BE THE MOST LIKELY PLACES TO SEE THE FOG. BECAUSE
OF THE ABOVE...PATCHY FOG WAS ADDED TO THE FORECAST IN THE
ABOVEMENTIONED LOCATIONS.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/...
A MID LEVEL SHORT WAVE WAS LOCATED OVER THE CANADIAN PRAIRIES AND
THE NORTHERN GREAT PLAINS THIS AFTERNOON. THE FEATURE WILL RACE TO
THE EAST AND IT SHOULD PASS OVER THE NORTHEASTERN STATES LATE ON
WEDNESDAY. A SURFACE COLD FRONT IS EXPECTED TO ACCOMPANY THE SHORT
WAVE.
AHEAD OF THE APPROACHING SYSTEM ON WEDNESDAY, A SOUTHWESTERLY WIND
WILL INCREASE AGAIN FOR THE LATE MORNING AND AFTERNOON HOURS.
TEMPERATURES SHOULD RISE INTO THE 50S IN MUCH OF OUR REGION WITH
READINGS STAYING IN THE 40S IN OUR NORTHWESTERN COUNTIES.
BEING THAT THEY WILL BE FAST MOVING, THE SHORT WAVE AND THE FRONT
SHOULD HAVE LIMITED OPPORTUNITY TO TAP INTO ANY SIGNIFICANT MOISTURE
SOURCE. AS A RESULT, CLOUDS WILL BE LIMITED AND WE ARE NOT
ANTICIPATING ANY PRECIPITATION FOR WEDNESDAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
AFTER THE DRY COLD FRONT PUSHES THROUGH A SHOT OF HIGH PRESSURE
NOSES BACK PROVIDING ANOTHER TRANQUIL DAY ACROSS OUR REGION WITH
LIGHT NORTHERLY WINDS. THIS WILL BE THE LAST DAY FOR A FEW OF OUR
RATHER BENIGN WEATHER AS THINGS START TO BECOME INTERESTING BY
FRIDAY MORNING.
A ONCE STRONG LOW PRESSURE SYSTEM WILL BE EJECTED OUT OF THE
MID-WEST AND PASS OVER THE GREAT LAKES REGION ON FRIDAY. THE SYSTEM WILL
HAVE LOST A BETTER PART OF ITS ASSOCIATED MID-LEVEL ENERGY WITH
NOTHING MORE THAN A SHORTWAVE TROUGH OF LOW PRESSURE LEFT OVER.
MODELS THIS AFTERNOON HAVE TRENDED A BIT SLOWER WITH THE ONSET OF
PRECIPITATION ACROSS A MAJORITY OF THE MID-ATLANTIC REGION WHICH
WILL PLAY HAVOC ON TRYING TO FORECAST ANY P-TYPE ISSUES. THERE DOES
LOOK TO BE ENOUGH DRY AIR IN THE LOWER PART OF THE COLUMN TO PREVENT
PRECIPITATION REACHING THE GROUND BEFORE 12Z FRIDAY. WITH THAT BEING
SAID NOT SURE HOW MUCH COLD AIR WILL REMAIN IN PLACE AT THE SURFACE
ACROSS OUR NORTHERN ZONES IN THE WAKE OF STRONGER WARM AIR ADVECTION
TAKING PLACE...STILL MAINTAIN A FEW HOURS OF FREEZING RAIN ACROSS
THE NORTH WITH SOME ACCUMULATION POSSIBLE...DETAILS HAVE TO WORKED
OUT.
THIS SYSTEM WILL PUSH OFF TO THE NORTHEAST AS THE SOUTHEAST RIDGE
RE-ESTABLISHES ITSELF ACROSS OUR AREA LATE FRIDAY AND SATURDAY. THIS
WILL CONTINUE A STAUNCH MID-LEVEL SOUTHWEST FLOW OVERHEAD PUMPING IN
MORE MOISTURE AND WARMER TEMPERATURES. THE DRIER WEATHER WILL BE
SHORT LIVED AS ANOTHER COMPLEX LOW PRESSURE SYSTEM APPROACHES FROM
THE WEST ON SUNDAY SPILLING INTO MONDAY. THIS SYSTEM IS RATHER SLOW
MOVING WHEN COMPARED TO THE PRIOR SYSTEM AND THIS TIME THERE WILL BE
MORE MOISTURE TO TAP INTO. MODELS ARE SHOWING MULTIPLE WAVES OF
ENERGY MOVING WITHIN THE SOUTHWEST FLOW ALOFT WHICH COULD PROVIDE A
DECENT AMOUNT OF RAIN ACROSS OUR AREA THROUGH MONDAY...LOOKS LIKE A
MORE NORTHERLY TRACK IS LIKELY MEANING OUR NORTHERN AREAS HAVE THE
BETTER CHANCES.
AS THIS SYSTEM SLIDES TO OUR EAST THE FRONTAL BOUNDARY LOOKS TO PUSH
TO THE SOUTH OF OUR REGION ALLOWING COLDER, DRIER CANADIAN AIR TO
FILTER BACK IN...ANY LINGERING PRECIPITATION COULD CHANGE BACK OVER
TO SNOW/FLURRIES. MODELS ARE UNSURE IF THE FRONT WILL COMPLETELY
MOVE OUT OF OUR REGION OR KEEP IT CLOSE ENOUGH TO ALLOW MORE ENERGY
TO TREK ALONG IT AND THROUGH OUR AREA BY MID-WEEK.
TEMPERATURE-WISE, WE WILL CONTINUE THE ABOVE AVERAGE TREND WITH THE
WARMEST DAY OF THE EXTENDED LOOKING LIKE SATURDAY AS TEMPERATURES
COULD EASILY CLIMB INTO THE UPPER-50S IN A LOT OF THE AREA. WE WAVER
A BIT GOING INTO NEXT WEEK BUT SHOULD STILL REMAIN ABOVE NORMAL.
AFTER THE FRONT PASSAGE ON MONDAY WE SHOULD DROP BACK TO AROUND
NORMAL.
&&
.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
VFR CONDITIONS CONTINUE EARLY THIS EVENING. FOR MOST PLACES...THERE
IS JUST HIGH CLOUDINESS...WHICH IS THINNING WITH TIME. AN AREA OF
VFR CLOUDINESS (WITH BASES NEAR 5000 FEET) IS CROSSING DELAWARE AND
EXTREME SOUTHERN NEW JERSEY EARLY THIS EVENING. IT IS POSSIBLE THAT
KMIV (AND TO A LESSER DEGREE KACY) COULD BE AFFECTED ENOUGH BY THE
CLOUDINESS TO ALLOW FOR AN HOUR OR TWO OF VFR CEILINGS IN THESE
LOCATIONS.
AFTER THE LOWER CLOUDS EXIT LATER THIS EVENING...MAINLY VFR
CONDITIONS ARE EXPECTED. A SHORT PERIOD OF MVFR VISIBILITIES IN
PATCHY FOG IS POSSIBLE IN PLACES LIKE KRDG AND KMIV...MOST LIKELY
BETWEEN 0800 UTC AND 1200 UTC WEDNESDAY. MODEL SOUNDINGS ARE
INDICATING THE POTENTIAL FOR LIFR CEILINGS IN MOST LOCATIONS BETWEEN
0800 UTC AND 1300 UTC WEDNESDAY. WHILE LOW LEVEL MOISTURE MAY BECOME
AVAILABLE DUE TO COOLING...THE POTENTIAL FOR LOW CEILINGS IS LOW AND
WAS NOT INCLUDED IN THE NEW TERMINAL FORECASTS..
VFR CONDITIONS ARE EXPECTED WEDNESDAY...WITH MAINLY HIGH AND MID
LEVEL CLOUDINESS. LIGHT SOUTHWEST WINDS IN THE MORNING WILL INCREASE
DURING THE AFTERNOON. THERE IS THE POTENTIAL FOR GUSTS NEAR 20 KNOTS
BETWEEN 1800 AND 2200 UTC WEDNESDAY...AHEAD OF A COLD FRONT. THE
GUSTS WERE INCLUDED IN THE KPHL TERMINAL FORECAST FOR WEDNESDAY
AFTERNOON.
THE COLD FRONT IS EXPECTED TO CROSS THE KPHL METRO AIRPORTS BETWEEN
0100 AND 0300 UTC THURSDAY. VFR CONDITIONS ARE EXPECTED WITH A WIND
SHIFT TO THE WEST NORTHWEST.
OUTLOOK...
.WEDNESDAY NIGHT - THURSDAY NIGHT...VFR. WINDS NORTHERLY 10-15 KT.
.FRI...RAIN DEVELOPING EARLY IN THE DAY WITH POSSIBLE MVFR OR
LOWER CONDITIONS.
.SAT...VFR.
.SUN...VFR.
&&
.MARINE...
HIGH PRESSURE LOCATED WELL OFF THE COAST WILL CONTINUE TO INFLUENCE
OUR REGION INTO WEDNESDAY. A DRY COLD FRONT WILL LIKELY APPROACH
FROM THE NORTHWEST LATE IN THE DAY. WIND SPEEDS AND WAVE HEIGHTS ARE
FORECAST TO REMAIN BELOW THE SMALL CRAFT ADVISORY CRITERIA FOR
TONIGHT AND WEDNESDAY.
OUTLOOK...
AFTER THE AFOREMENTIONED COLD FRONT SWINGS THROUGH THERE LOOKS TO
BE A FEW HOURS OF SCA WIND GUSTS AS STRONG COLD AIR ADVECTION,
COMBINED WITH A TIGHT PRESSURE GRADIENT ACROSS OUR NORTHERN WATER
ESTABLISHES ITSELF...A SCA FLAG HAS BEEN RAISED FROM 23Z TO 11Z
THURSDAY. AFTER THIS WE SHOULD RETURN TO MORE TRANQUIL CONDITIONS
EVEN THOUGH ANOTHER LOW PRESSURE SYSTEM WILL IMPACT OUR WATERS
THURSDAY NIGHT INTO FRIDAY. HIGH PRESSURE THEN REGAINS CONTROL ON
SATURDAY.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 PM WEDNESDAY TO 6 AM EST THURSDAY
FOR ANZ450>452.
&&
$$
SYNOPSIS...HEAVENER
NEAR TERM...HAYES
SHORT TERM...IOVINO
LONG TERM...HEAVENER
AVIATION...HAYES/HEAVENER
MARINE...IOVINO/HEAVENER
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
952 AM EST MON JAN 7 2013
.SYNOPSIS...
A WEDGE OF HIGH PRESSURE WILL BUILD INTO THE REGION AND PREVAIL
THROUGH TUESDAY...WHILE A COASTAL TROUGH OF LOW PRESSURE STRENGTHENS
OFFSHORE. A WEAK WARM FRONT WILL LIFT NORTH OF THE AREA WEDNESDAY
INTO THURSDAY AS A STORM SYSTEM PASSES WELL TO THE WEST. ATLANTIC
HIGH PRESSURE WILL THEN PREVAIL INTO EARLY NEXT WEEK BEFORE A COLD
FRONT APPROACHES FROM THE WEST.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
07/14Z SURFACE ANALYSIS SHOWED HIGH PRESSURE WEDGED IN SOLIDLY
ACROSS THE REGION. A THICK RIBBON OF JET ENHANCED CIRROSTRATUS IS
HOLDING FIRM...BUT RAP MOISTURE PROFILES SUGGEST IT WILL GRADUALLY
MIX OUT AS THE SUPPORTING UPPER JET SHIFTS FARTHER OFFSHORE.
EXPECT PARTLY CLOUDY SKIES TO GRADUALLY BECOME MOSTLY SUNNY LATER
TODAY...MAINLY ACROSS SOUTHEAST SOUTH CAROLINA AND POSSIBLY FAR
INTERIOR SOUTHEAST GEORGIA. THE ONSHORE FLOW WILL LIKELY SUPPORT A
SLIGHT INCREASE IN MOISTURE ACROSS THE SOUTH WHICH COULD
TRANSITION TO A SHALLOW CUMULUS FIELD. IN ADDITION...SOME MARINE
STRATOCUMULUS WILL LIKELY MOVE ONSHORE ACROSS PARTS OF THE GEORGIA
COAST. ALL OF THIS SHOULD PRODUCE PARTLY CLOUDY SKIES FOR MUCH OF
SOUTHEAST GEORGIA...ESPECIALLY SOUTH OF I-16. HIGHS FROM THE MID
50S NORTH TO AROUND 60 ALONG THE ALTAMAHA RIVER LOOK ON TRACK.
BEACH LOCATIONS WILL LIKELY ONLY TOP OUT IN THE LOWER 50S WITH
SOME SPOTS HOLDING IN THE UPPER 40S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
TONIGHT...ISENTROPIC LIFT WILL STRENGTHEN AS WILL A COASTAL TROUGH
OF LOW PRESSURE OFFSHORE. EXPECT CLOUD COVER TO INCREASE TOWARD
DAYBREAK FROM THE SOUTH AND EAST. THERE COULD BE SOME LIGHT RAIN
AS WELL...MAINLY NEAR THE COAST LATE. LOWS WILL LIKELY DROP
QUICKLY AT SUNSET AND THEN BECOME MAINLY STEADY OVERNIGHT AS THE
CLOUD COVER INCREASES...ESPECIALLY AROUND THE COAST. GOING FOR
LOWS IN THE MID 30S INLAND AND AROUND 40 CLOSER TO THE
COAST...WITH MID TO UPPER 40S LIKELY ALONG THE BEACHES.
TUESDAY...A WEDGE OF HIGH PRESSURE WILL BECOME ENTRENCHED OVER THE
FORECAST AREA AS A COASTAL TROUGH STRENGTHENS OFFSHORE. LOW LEVEL
MOISTURE TRAPPED BENEATH THE INVERSION AND DEVELOPING ISENTROPIC
ASCENT WILL RESULT IN CONSIDERABLE CLOUDINESS ACROSS THE AREA. THERE
IS A SLIGHT CHANCE OF RAIN ALONG THE GEORGIA COAST AND NEAR THE
ALTAMAHA RIVER ON TUESDAY WHERE LOW LEVEL MOISTURE AND CONVERGENCE
WILL BE GREATEST. THEN...EXPECT A SLIGHT CHANCE OF RAIN ACROSS THE
ENTIRE FORECAST AREA TUESDAY NIGHT AS MOISTURE DEEPENS AND
ISENTROPIC LIFT INCREASES. TEMPERATURES WILL STRUGGLE TO WARM WITHIN
THE WEDGE...WITH HIGHS RANGING FROM THE MID 50S IN THE NORTHWEST TO
THE LOWER 60S NEAR THE ALTAMAHA RIVER AND GEORGIA COAST. LOWS
TUESDAY NIGHT SHOULD BE IN THE MID TO UPPER 40S INLAND AND IN THE
LOWER 50S NEAR THE COAST.
WEDNESDAY...FORECAST CONFIDENCE IS EXTREMELY LOW AS THE MODELS ARE
PROVIDING MIXED SIGNALS WITH RESPECT TO THE WEDGE AND HOW QUICKLY IT
ERODES. THE MID AND UPPER LEVEL PATTERN WILL CERTAINLY FEATURE A
STRENGTHENING RIDGE OVER THE SOUTHEAST STATES. THERE IS SOME
INDICATION THAT A WEAK WARM FRONT MAY ACTUALLY TRY TO DEVELOP NEAR
THE AREA AND HOOK UP WITH THE COASTAL TROUGH. HOWEVER...WARM AIR
ADVECTION ALOFT WITH PLENTIFUL LOW LEVEL MOISTURE AND THE POTENTIAL
FOR ISOLATED TO SCATTERED SHOWERS WOULD ALL SUPPORT MAINTAINING THE
WEDGE...AT LEAST INLAND FROM THE COAST WHERE THE TROUGH MAY TRY TO
SHIFT ONSHORE. WHILE H8-H5 THICKNESS VALUES SUPPORT HIGHS WELL INTO
THE 70S...THIS IS NOT TAKING INTO ACCOUNT THE LOW LEVEL ENVIRONMENT.
HAVE THEREFORE OPTED TO LEAN HEAVILY ON THE COOLEST GUIDANCE AND
WILL KEEP HIGHS ONLY IN THE MID TO UPPER 60S ACROSS MOST OF THE
AREA. IF THE WEDGE BREAKS AND SOME CLEARING OCCURS...THEN THESE
TEMPERATURES COULD BE A GOOD 5-10 DEGREES TOO COOL.
THURSDAY...THE MID AND UPPER LEVEL PATTERN WILL BECOME MORE
AMPLIFIED AS THE RIDGE EXTENDS UP THE EASTERN SEABOARD WHILE A STORM
SYSTEM LIFTS NORTHEAST ACROSS THE MISSISSIPPI VALLEY. AS THIS
OCCURS...THE WARM FRONT WILL BEGIN TO LIFT NORTH OF THE AREA FINALLY
ALLOWING THE WEDGE TO ERODE. THERE WILL BE SCATTERED SHOWERS DURING
THE DAY...ESPECIALLY ACROSS SOUTHEAST SOUTH CAROLINA CLOSER TO THE
WARM FRONT. CONFIDENCE INCREASES THAT MUCH WARMER TEMPERATURES WILL
OCCUR...WITH HIGHS IN THE LOWER TO MID 70S ACROSS THE AREA AWAY FROM
THE COAST.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
A WEAKENING COLD FRONT TRAILING FROM A STORM SYSTEM LIFTING ACROSS
THE GREAT LAKES REGION COULD DROP INTO THE AREA ON FRIDAY...BUT A
LACK OF SUFFICIENT MOISTURE/FORCING SHOULD KEEP CONDITIONS
RAIN-FREE. ATLANTIC HIGH PRESSURE AND STRONG RIDGING ALOFT WILL THEN
RESULT IN DRY CONDITIONS THROUGH THE WEEKEND ALONG WITH A
CONTINUATION OF WELL ABOVE NORMAL TEMPERATURES. THE RIDGING WILL
BEGIN TO BREAK DOWN EARLY NEXT WEEK AS A COLD FRONT APPROACHES
FROM THE WEST.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS WILL PREVAIL THROUGH 12Z TUESDAY AT KCHS AND KSAV.
LOW-LEVEL MOISTURE WILL BE ON THE INCREASE AFTER MIDNIGHT BUT ANY
CEILINGS SHOULD REMAIN VFR.
EXTENDED AVIATION OUTLOOK...MVFR OR LOWER CIGS LIKELY TUESDAY THROUGH
LATE WEDNESDAY AS A WEDGE OF HIGH PRESSURE DEVELOPS OVER BOTH
TERMINALS. MVFR CIGS/VSBYS POSSIBLE ON THURSDAY WITH A WARM FRONT
LIFTING NORTH OVER THE AREA.
&&
.MARINE...
TODAY...POOR MARINE CONDITIONS WILL PERSIST ACROSS THE WATERS
TODAY WITH SMALL CRAFT ADVISORY CONDITIONS OCCURRING OVER THE
GEORGIA OFFSHORE WATERS. BUOY AND PILOT BOAT REPORTS INDICATE
WINDS ARE A SOLID 15-20 KT NEARSHORE AND ARE LIKELY CLOSER TO
20-25 KT BEYOND 20 NM OFF THE GEORGIA COAST. WILL HAVE TO WATCH
FOR A POTENTIAL PINCHING OF THE PRESSURE GRADIENT ALONG THE COAST
WHICH COULD TIP WINDS INTO ADVISORY THRESHOLDS OVER THE NEARSHORE
WATERS...BUT KEPT CONDITIONS BELOW FOR NOW.
TONIGHT...POOR MARINE CONDITIONS TONIGHT AS AN INLAND HIGH
PRESSURE WEDGE/OFFSHORE COASTAL TROUGH OF LOW PRESSURE PATTERN
SETS UP. THIS WILL KEEP BRISK NORTH/NORTHEAST WINDS IN
PLACE...ESPECIALLY TODAY. SEAS WILL BUILD AS WELL GIVEN THE STRONG
WINDS AND FAVORABLE FETCH AND WE SHOULD SEE SMALL CRAFT ADVISORY
CONDITIONS AT LEAST BEYOND 20 NM FROM SHORE.
TUESDAY THROUGH SATURDAY...WINDS/SEAS WILL REMAIN ELEVATED OVER THE
WATERS THROUGH TUESDAY AS THE PRESSURE GRADIENT REMAINS ENHANCED
BETWEEN BUILDING HIGH PRESSURE INLAND AND A STRENGTHENING COASTAL
TROUGH ALONG THE SOUTHEAST COAST. A SMALL CRAFT ADVISORY WILL REMAIN
IN EFFECT FOR THE OUTER GEORGIA WATERS THROUGH TUESDAY MORNING AS A
RESULT. THE TROUGH WILL PERSIST THROUGH WEDNESDAY THEN SLOWLY MOVE
NORTH OF THE AREA AS A WARM FRONT ON THURSDAY. ALTHOUGH WINDS WILL
DIMINISH ACROSS THE ENTIRE MARINE AREA BY TUESDAY NIGHT THERE COULD
BE PERIODS OF ENHANCED WINDS THROUGH MID WEEK DEPENDING ON WHERE THE
BEST GRADIENT SETS UP...MOST LIKELY ACROSS THE CHARLESTON NEARSHORE
WATERS. A SOUTHERLY FLOW WILL THEN DEVELOP LATE THIS WEEK INTO THE
WEEKEND AS ATLANTIC HIGH PRESSURE BUILDS INTO THE REGION. A RISK OF
SEA FOG REMAINS OVER THE COOL NEARSHORE WATERS LATE WEEK...AS A
WARMER AND MORE HUMID AIRMASS MOVES INTO THE AREA.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST TUESDAY FOR AMZ374.
&&
$$
ST
AREA FORECAST DISCUSSION
NWS JACKSON KY
131 AM EST MON JAN 7 2013
.UPDATE...
ISSUED AT 130 AM EST MON JAN 7 2013
CLOUDS WILL LIKELY LINGER MUCH LONGER THAN ORIGINALLY THOUGHT AND
INDICATED FROM MODELS. OUTSIDE OF A BRIEF CLEARING PUSHING SOUTH
PRESENTLY...CLOUDS EXTEND BACK WELL TO THE NORTH AND UNTIL THE RIDGE
AXIS PUSHES ACROSS THE AREA LATER THIS AFTERNOON...WE WILL LIKELY SEE
LOW CLOUDS HANG IN SUPPORTED BY SOME WEAK NORTHEAST TO EASTERLY LOW
LEVEL FLOW. RUC SEEMS TO HAVE THE BEST HANDLE ON THE CLOUDS. HAVE
UPDATED THE FORECAST ACCORDINGLY AND MAY NEED TO TAKE A LOOK AT HIGH
TEMPERATURES TODAY AS LOW CLOUDS COULD KEEP THINGS A BIT COOLER. THE
EXCEPTION IS IN THE FAR SOUTHWEST WHICH SHOULD CLEAR OUT BASED ON
CURRENT SATELLITE TRENDS. THUS...KEPT OVERNIGHT LOWS COOLER TO THE
SOUTHWEST. OTHERWISE...ADJUSTED EVERYONE ELSE UP WITH THEIR LOWS
TONIGHT.
UPDATE ISSUED AT 826 PM EST SUN JAN 6 2013
PCPN HAS MOVED EAST AND WINDS HAVE SHIFTED TO THE NORTHWEST BUT ARE
STILL GUSTY. WINDS SHOULD DIMINISH LATER THIS EVENING. HAVE UPDATED
ZONES AND GRIDS WITH CURRENT CONDITIONS.
UPDATE ISSUED AT 625 PM EST SUN JAN 6 2013
SFC COLD FRONT IS THRU ABOUT HALF THE CWFA. WINDS BEHIND THE FRONT
HAVE SHIFTED TO THE NORTHWEST AND ARE GUSTY. FEW SPRINKLES OR LIGHT
DRIZZLE PUSHING INTO THE ERN COUNTIES. UPDATED GRIDS BUT ZONES STILL
IN GOOD SHAPE. NEXT UPDATE AFTER PCPN EXITS THE CWFA.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 240 PM EST SUN JAN 6 2013
THE SURFACE COLD FRONT IS CURRENTLY ALIGNED JUST WEST OF A LINE FROM
KCVG TO KSDF TO KBWG. THE MODELS CONTINUE TO SHOW THE BETTER CHANCES
OF MEASURABLE QPF MAINLY NORTHEAST OF THE AREA. AS SUCH...WILL ONLY
ALLOW FOR A SLIGHT CHANCE OF MEASURABLE PRECIPITATION FROM LATE THIS
AFTERNOON THROUGH EARLY THIS EVENING...MAINLY FOR THE NORTHEASTERN TWO
THIRDS OF THE COUNTIES...WITH JUST SOME SPRINKLES POSSIBLE FOR THE
SOUTHWEST.
CLEARING WILL LIKELY BE TOUGH TONIGHT...WITH SURFACE COLD AIR
ADVECTION AND NORTHWEST WINDS FAVORING A LINGERING STRATOCU DECK.
WILL THEREFORE FAVOR THE NAM IDEA ON TEMPERATURES...GENERALLY LOWER
20S IN THE WEST...AND MORE MID 20S IN THE EAST.
SKIES WILL CLEAR OUT DURING MORNING HOURS ON MONDAY...WITH
HIGHS RECOVERING TO THE LOWER TO MIDDLE 40S AS UPPER LEVEL RIDGING
BUILDS IN OVERHEAD. BESIDES SOME HIGH CIRRUS...MONDAY NIGHT WILL BE
CLEAR...WITH SOME OF THE DEEPER VALLEYS IN THE EAST LIKELY GETTING
DOWN INTO THE TEENS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 355 PM EST SUN JAN 6 2013
UPPER LEVEL AND SFC RIDGING ARE EXPECTED TO BE SHIFTING EAST OF THE
REGION AT THE START OF THE PERIOD. MODELS THEN TAKE A TROUGH FROM THE
NORTHERN PLAINS ACROSS THE GREAT LAKES AND INTO EASTERN CANADA FROM
TUESDAY INTO WEDNESDAY WHILE A CLOSED LOW INITIALLY OVER NORTHERN
MEXICO MEANDERS TOWARD THE SOUTHERN PLAINS. THE TROUGH PASSING BY TO
OUR NORTH ON TUE NIGHT INTO EARLY WED SHOULD SEND A SFC TROUGH ACROSS
THE REGION ON TUE NIGHT INTO EARLY ON WED...ALONG WHICH THE ECMWF AND
GFS BOTH HAVE MOISTURE INCREASING BRIEFLY. THE GFS IS MORE ROBUST
WITH IT...BUT DOES HAVE SOME SUPPORT FORM THE ECMWF. AT THE SAME TIME...
THE MODELS SEEM TO BE DEVELOPING SOME LIFT ACROSS THE AREA ASSOCIATED
WITH THE RIGHT ENTRANCE REGION PASSING BY TO OUR NORTH DURING THE
LATE TUE NIGHT INTO EARLY ON WED PERIOD. POPS WERE INCREASED TO
SLIGHT CHANCE ACROSS THE SOUTHWEST HALF OF THE AREA FOR THIS FOR LATE
TUE NIGHT INTO EARLY ON WED...PER ISC COORDINATION.
THEN...MODELS TRACK THE UPPER LEVEL LOW AND IT SFC SYSTEM SLOWLY FROM
THE SOUTHERN PLAINS TO THE MID MS VALLEY FROM WED INTO THU EVENING
PER GFS OR A BIT LATER AND SOUTHEAST THU NIGHT PER ECMWF. THIS WOULD
HAVE THE WARM FRONT ASSOCIATED WITH THE SYSTEM MOVING NORTH OF THE
AREA ON THU EVENING OR THU NIGHT WITH THE COLD FRONT TO FOLLOW ON
FRI. THE HIGHEST POPS ON AVERAGE ACROSS THE REGION WILL BE ON THU ON
AVERAGE...AND HIGHEST DURING THE WED NIGHT INTO THU NIGHT PERIOD IN
THE WEST WITH THE UPPER SYSTEM TO PASS BY TO THE NORTHWEST. THE
HIGHEST POPS ON FRI WERE IN THE EAST IN ADVANCE OF THE COLD FRONT.
THIS FRONT...HOWEVER...WILL MAINLY JUST USHER IN DRIER AIR WILL
LITTLE TEMP DIFFERENCES ANTICIPATED BEHIND IT.
THERE SHOULD BE A RATHER BRIEF WINDOW OF INACTIVE WEATHER FROM
FRI AFTERNOON INTO MUCH OF SAT NIGHT. AFTER THAT TIME...THE NEXT
TROUGH AND ASSOCIATED SFC SYSTEM WILL BEGIN TO APPROACH FROM THE
WEST...BUT EVENTUALLY SHOULD SLOW DOWN AND PERHAPS STALL AS IT NEARS
THE REGION. THAT SCENARIO WOULD POINT TOWARD THREAT OF HEAVY
RAIN...BUT MODEL DIFFERENCES REMAIN BETWEEN MODELS AND RUN TO RUN.
WITH THAT IN MIND...A FORECAST VERY CLOSE TO THE GRID LOAD WAS
FOLLOWED FOR POPS LATE IN THE PERIOD.
TEMPERATURE RANGES FROM WED ON WILL BE DIURNALLY LIMITED DUE TO
EXPECTED CLOUD COVER AND PRECIP CHANCES. READINGS THROUGH THE ENTIRE
PERIOD WILL AVERAGE ABOVE NORMAL...PERHAPS NEARLY 20 DEGREES ABOVE
NORMAL FOR THU NIGHT THROUGH SAT NIGHT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 130 AM EST MON JAN 7 2013
MVFR CIGS WILL CONTINUE OVERNIGHT EXCEPT ACROSS SOUTH CENTRAL
KENTUCKY NEAR KSME...WHERE SKIES ARE EXPECTED TO CLEAR SHORTLY.
OTHERWISE...ANY CLEARING FURTHER EAST IS EXPECTED TO TAKE AWHILE WITH
CLOUDS HOLDING IN A JKL PERHAPS WELL PAST DAYBREAK AND MAYBE EVEN
INTO THE EARLY AFTERNOON HOURS. BY THIS EVENING...WE SHOULD FINALLY
SEE A BETTER PUSH FOR CLEARING SKIES AS THE MID LEVEL RIDGE PUSHES
EAST. WINDS WILL TURN MORE LIGHT AND VARIABLE AS WE HEAD THROUGH THE
NIGHT AND REMAIN THAT WAY THROUGH TODAY AND TONIGHT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...GEOGERIAN
LONG TERM....JP
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS DULUTH MN
300 AM CST MON JAN 7 2013
.SHORT TERM...TODAY THROUGH TUESDAY.
SURFACE LOW PRESSURE OVER SOUTHERN MANITOBA WILL MOVE INTO ONTARIO
TODAY. NORTHERN PORTIONS OF THE FORECAST AREA WILL SEE MORE CLOUDS
AND A SLIGHT CHANCE OF FLURRIES DURING THE DAY. THE LOW PRESSURE
SYSTEM COMBINED WITH A SURFACE HIGH PRESSURE SYSTEM OVER THE OHIO
RIVER VALLEY WILL BRING BRISK SOUTHWESTERLY WINDS TO THE AREA.
CLOUDS WILL DECREASE OVER THE NORTH TONIGHT AS THE LOW MOVES FURTHER
TO THE EAST. ON TUESDAY A LOW PRESSURE SYSTEM OVER SOUTHERN
SASKATCHEWAN WILL MOVE ALONG THE INTERNATIONAL BORDER AND BRING A
CHANCE OF LIGHT SNOW TO THE NORTHLAND ON TUESDAY AFTERNOON.
TEMPERATURES WILL BE ABOVE NORMAL TODAY WITH THE BRISK SOUTHWESTERLY
WINDS THAT WILL BRING HIGHS INTO THE UPPER 20`S AND LOWER 30`S.
HIGHS ON TUESDAY WILL ALSO BE ABOVE NORMAL WITH TEMPERATURES
GENERALLY IN THE LOWER 30`S.
.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY.
A SFC LOW WILL TRAVEL FROM MANITOBA TO ONTARIO TUESDAY NIGHT
ACCOMPANIED BY A NEGATIVELY TILTED UPPER TROF. THESE FEATURES WILL
PUSH A FRONTAL BOUNDARY THROUGH THE FA. WILL CONTINUE TO CARRY THE
CHANCE POPS...TRENDING DOWNWARD OVERNIGHT. SOME LIGHT ACCUMULATION
IS POSSIBLE ESPECIALLY NEAR THE CANADIAN BORDER WHERE UP TO AN INCH
COULD FALL...LESSER AMOUNTS FURTHER SOUTH. SOME LINGERING LIGHT SNOW
IS PROBABLE OVER THE ARROWHEAD WEDNESDAY MORNING AS THE UPPER TROF
DEPARTS. RIDGING FOLLOWS FOR WEDNESDAY AFTERNOON. THE RIDGE AXIS
MOVES FARTHER EAST WEDNESDAY NIGHT WHICH ALLOWS FOR STRONG WAA TO
SET UP AHEAD OF A DEVELOPING SYSTEM IN THE ROCKIES. 850MB TEMPS
SURGE TO AROUND 7C BY 12Z THURSDAY LEADING TO MAX TEMPS IN THE
MIDDLE TO UPPER 30S ON THURSDAY. CLOUDS WILL BE ON THE INCREASE
THURSDAY AFTERNOON AS A CLOSED UPPER LOW MOVES THROUGH THE SOUTHERN
PLAINS. THIS WILL HELP PULL SOME GULF MOISTURE NORTHWARD. AS THE
UPPER LOW OPENS INTO A LONG WAVE TROF THURSDAY NIGHT...THE FA WILL
BE BETWEEN A SFC LOW NEAR CHICAGO AND ANOTHER OVER THE NORTHERN
PLAINS. WITH THE WARM AIR IN PLACE...HAVE SMALL POPS OVER THE
SOUTHERN FA FOR LIGHT RAIN THURSDAY AFTERNOON. AS COOLING OCCURS
THURSDAY NIGHT NEAR THE SFC...A MIX OF LIGHT RAIN/FREEZING RAIN IS
POSSIBLE WHERE SFC TEMPS WILL BE NEAR 32F. HAVE A MENTION OF LIGHT
SNOW OVER THE FAR NW PORTION OF THE FA WHICH IS SUPPORTED BY
FORECAST SOUNDINGS. AS THE SFC LOW MOVES FROM ND INTO SW ONTARIO ON
FRIDAY...WILL SEE AN OPPORTUNITY FOR LIGHT RAIN IN THE SE
FA...MIXING WITH LIGHT SNOW IN THE CENTRAL FA...TO ALL SNOW OVER THE
NORTH AND WEST AS COLDER AIR ARRIVES. AT THIS POINT...THE MODELS
BEGIN TO DIVERGE AS THE OVERALL UPPER FLOW BECOMES SW THANKS TO A
LARGE WEST COAST TROF. WILL CONTINUE WITH THE BLENDED APPROACH TO
POPS FOR THE REST OF THE EXTENDED AND THE PTYPE SHOULD BE ALL SNOW
WITH COLDER AIR LEAKING DOWN FROM CANADA.
&&
.AVIATION...06Z TAFS
MAINLY VFR CONDITIONS COVERED THE NORTHLAND LATE THIS EVENING. THE
MVFR CEILINGS COMING OFF OF LAKE SUPERIOR HAVE DIMINISHED ALONG
THE NORTH SHORE AS LOW TEMPERATURES HAVE RISEN. IFR CEILINGS IN
NORTHWEST MINNESOTA MAY STILL BRUSH KINL...BUT WE DID NOT PUT ANY
MENTION IN THE TAF ATTM.
A SHORTWAVE SCOOTING ALONG THE INTERNATIONAL BORDER MAY BRING SOME
LOWER CEILINGS TO KINL MONDAY MORNING. THE RAP 900MB CONDENSATION
PRESSURE DEFICITS SEEM TO BE HANDLING THIS FAIRLY WELL...AND SHOW
LOWER VALUES REACHING KINL AROUND 13Z...BUT IT JUST BRUSHES THAT
AREA. WE BRING IN PREDOMINATE MVFR CEILINGS THERE IN THE
AFTERNOON. SOME FLURRIES MAY ACCOMPANY THOSE LOWER CEILINGS.
LLWS WILL REMAIN A THREAT TONIGHT. THE WOOD LAKE PROFILER SHOWS
50 KNOTS AT 925MB AND THAT IS LINE WITH THE NAM.
&&
.POINT TEMPS/POPS...
DLH 31 14 30 22 / 0 0 30 40
INL 31 10 28 19 / 10 10 30 50
BRD 31 12 32 20 / 0 0 30 30
HYR 32 12 33 22 / 0 0 20 40
ASX 32 17 35 25 / 0 0 10 40
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 10 PM CST THIS EVENING FOR LSZ121-
140>148.
&&
$$
SHORT TERM...KK
LONG TERM....GSF
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS DULUTH MN
1144 PM CST SUN JAN 6 2013
.AVIATION...06Z TAFS
MAINLY VFR CONDITIONS COVERED THE NORTHLAND LATE THIS EVENING. THE
MVFR CEILINGS COMING OFF OF LAKE SUPERIOR HAVE DIMINISHED ALONG
THE NORTH SHORE AS LOW TEMPERATURES HAVE RISEN. IFR CEILINGS IN
NORTHWEST MINNESOTA MAY STILL BRUSH KINL...BUT WE DID NOT PUT ANY
MENTION IN THE TAF ATTM.
A SHORTWAVE SCOOTING ALONG THE INTERNATIONAL BORDER MAY BRING SOME
LOWER CEILINGS TO KINL MONDAY MORNING. THE RAP 900MB CONDENSATION
PRESSURE DEFICITS SEEM TO BE HANDLING THIS FAIRLY WELL...AND SHOW
LOWER VALUES REACHING KINL AROUND 13Z...BUT IT JUST BRUSHES THAT
AREA. WE BRING IN PREDOMINATE MVFR CEILINGS THERE IN THE
AFTERNOON. SOME FLURRIES MAY ACCOMPANY THOSE LOWER CEILINGS.
LLWS WILL REMAIN A THREAT TONIGHT. THE WOOD LAKE PROFILER SHOWS
50 KNOTS AT 925MB AND THAT IS LINE WITH THE NAM.
&&
.PREV DISCUSSION... /ISSUED 729 PM CST SUN JAN 6 2013/
UPDATE...
TEMPERATURES HAVE DROPPED QUICKLY THIS EVENING...WITH SEVERAL
AREAS ALREADY BELOW FORECAST MINS. TEMPERATURES WILL BE A
CHALLENGE TONIGHT. WINDS SHOULD BE INCREASING...AND THAT WILL
ALLOW TEMPS TO REBOUND IN SPOTS...OR AT LEAST SLOW THE RAPID DROP.
AS LOW LEVEL WINDS HAVE BECOMING SOUTHERLY...LAKE CLOUDS HAVE
MOVED ASHORE BETWEEN SILVER BAY AND GRAND PORTAGE. DELTA-T VALUES
FROM THE SURFACE TO 850MB WILL BE AS HIGH AS 13C AT GRAND PORTAGE
EARLY THIS EVENING...BUT WAA WILL LEAD LOWERING DELTA-T`S AS THE
NIGHT PROGRESSES. WE DON`T EXPECT MUCH IN THE WAY OF SNOW SHOWERS
AS THE AIRMASS IS QUITE DRY...AND THEN STABILITIES WILL INCREASE.
PREV DISCUSSION... /ISSUED 540 PM CST SUN JAN 6 2013/
AVIATION...00Z TAFS
MAINLY VFR CONDITIONS COVERED THE NORTHLAND THIS EVENING...BUT
THERE WERE SOME MVFR CEILINGS COMING ONSHORE BETWEEN SILVER BAY
AND GRAND PORTAGE DUE TO SOUTHERLY WINDS. WE DO NOT EXPECT MUCH IN
THE WAY OF SNOW SHOWERS AS LOW LEVEL TEMPS ARE FORECAST TO
INCREASE OVERNIGHT. THERE WERE ALSO SOME IFR CEILINGS OVER WESTERN
AROUND KADC/KPKD NORTHWEST INTO THE UPPER RED RIVER VALLEY. THE
RAP SHOWS SOME LOW CEILINGS MAY AFFECT KINL FOR A FEW HOURS THIS
EVENING.
INCREASING SOUTH-SOUTHWEST LLJ WILL CREATE SOME LLWS AT ALL TAFS
FOR A PERIOD.
PREV DISCUSSION... /ISSUED 311 PM CST SUN JAN 6 2013/
SHORT TERM...
THIS AFTERNOON/TONIGHT THROUGH MONDAY NIGHT...
FAIRLY QUIET CONDITIONS THROUGH THE SHORT TERM WITH ONLY A FEW
FLURRIES POSSIBLE ACROSS THE NORTHERN COUNTIES DURING THE DAY
TOMORROW. TEMPERATURES WILL BE VERY MILD TONIGHT THROUGH MONDAY
NIGHT.
UPPER RIDGE BUILDING IN ACROSS THE DAKOTAS WITH A SFC RIDGE AXIS
EXTENDING FROM JAMES BAY SWWD INTO THE MO RIVER VALLEY. THE NEXT
SYSTEM...CURRENTLY LOCATED OVER THE CANADIAN ROCKIES...WILL MOVE
EWD ACROSS SRN CANADA AND BRUSH PARTS OF FAR NRN MN WITH A FEW
FLURRIES LATE TONIGHT AND THROUGH THE DAY MONDAY. THE MOST
FAVORABLE FORCING FOR SNOWFALL WILL REMAIN WELL TO THE
NORTH...CLOSER TO THE SFC LOW MOVING THROUGH SRN MANITOBA INTO WRN
ONTARIO. WILL SEE MAINLY ADDITIONAL CLOUD COVER WITH THIS SYSTEM
ACROSS THE NRN HALF OF THE FORECAST AREA...WITH PARTLY CLOUDY TO
MOSTLY SUNNY SKIES TO THE SOUTH. SHOULD SEE EVEN MORE CLEARING
MONDAY NIGHT AS THE SYSTEM MOVES TO THE EAST AND HIGH PRESSURE
BUILDS BACK IN FROM THE WEST.
TEMPERATURES TONIGHT WILL DROP INTO THE SINGLE DIGITS AND TEENS
ABOVE ZERO...WITH THE COLDEST TEMPS LIKELY OVER NW WI WHERE THE
GREATEST AMT OF CLEARING WILL OCCUR. STRONG SWLY FLOW TOMORROW
WILL USHER IN A SLIGHTLY WARMER AIR MASS THROUGH THE DAY AND ALLOW
TEMPERATURES TO RISE INTO THE UPPER 20S AND LOWER 30S...SOME 10
DEGREES ABOVE NORMAL. TEMPS WILL DROP INTO THE SINGLE DIGITS AGAIN
MON NIGHT.
LONG TERM...
TUESDAY THROUGH SUNDAY...
A SHORTWAVE WILL MOVE ACROSS THE NORTH DAKOTA/CANADA BORDER ON
TUESDAY AND THEN LIFT INTO NW ONTARIO BY TUESDAY NIGHT. THIS WILL
SPREAD LIGHT SNOW ACROSS THE REGION DURING THAT TIME AS THE TROUGH
DIGS AND TAKES ON A BIT OF A NEGATIVE TILT. THINGS SHOULD DRY OUT
FOR WEDNESDAY WITH A RIDGE OF HIGH PRESSURE ACROSS THE CWA. WAA
WILL ALREADY TAKE OVER WEDNESDAY NIGHT AS SOUTHWEST WINDS DEVELOP
AHEAD OF LOW PRESSURE MOVING THROUGH THE MANITOBA LAKES REGION. AN
UPPER LOW MOVING NORTHWARD FROM THE PLAINS STATES WILL MOVE IN ON
THURSDAY AND THURSDAY NIGHT. WILL HOLD OFF ON INTRODUCING
PRECIPITATION UNTIL THURSDAY AFTERNOON. THAT MAY EVEN BE A BIT
QUICK...BUT THE GFS DOES HAVE PRECIPITATION MOVING IN DURING THE
AFTERNOON IN THE SOUTH. THE ECMWF IS MUCH FURTHER SOUTH. THE
PRECIPITATION SHOULD CONTINUE INTO FRIDAY AND EVEN INTO THE
WEEKEND AS LOW PRESSURE EVOLVES TO OUR W/SW. THE MODELS CONTINUE
TO SHOW SOME PRETTY SIZEABLE DIFFERENCES WITH REGARD TO THE
EVOLUTION OF A STRONG SURFACE LOW BY 18Z SATURDAY. THE ECMWF
PRETTY MUCH CONFINES THE HEAVIEST PRECIPITATION TO OUR NW...WHILE
THE GFS FAVORS OUR CWA. NO MATTER WHAT...THE MODELS CONTINUE TO
PICK UP ON SOMETHING OF INTEREST FOR NEXT WEEKEND. WAY TOO EARLY
TO DETERMINE HOW EXACTLY IT WILL AFFECT OUR CWA AT THIS POINT.
TEMPERATURES WILL WARM CONSIDERABLY DURING THE WEEK WITH
TEMPERATURES SOARING THROUGH THE 30S. COULD EVEN SEE A 40 DEGREE
READING SOUTH ON THURSDAY/FRIDAY.
&&
.POINT TEMPS/POPS...
DLH 15 30 14 30 / 0 0 0 30
INL 11 30 10 28 / 10 10 10 30
BRD 12 30 12 32 / 0 0 0 30
HYR 13 31 12 34 / 0 0 0 20
ASX 15 31 17 35 / 0 0 0 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 10 PM CST MONDAY FOR LSZ121-140>148.
&&
$$
SHORT TERM...MELDE
AVIATION...MELDE
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
945 PM CST TUE JAN 8 2013
.UPDATE...
ISSUED AT 936 PM CST TUE JAN 8 2013
PRECIP HAS HELD TOGETHER BETTER THAN PROGD BY SOME OF THE
GUIDANCE. HAVE THEREFORE INCREASED POPS ACROSS THE SRN HALF OF THE
CWA. THE NRN EDGE OF RADAR RETURNS APPEARS TO BE DISSIPATING
SOMEWHAT...BUT WILL PULL SLIGHT CHANCE POPS FURTHER NWD IN CASE
THESE RETURNS HOLD TOGETHER. RAISED TEMPS OVERNIGHT A LITTLE AS
CLOUD COVER HAS HINDERED ANY COOLING AND WITH COOLER AIR NOT
ARRIVING UNTIL WED MORNING.
ISSUED AT 704 PM CST TUE JAN 8 2013
UPDATE TO INCREASE CLOUDS THRU THE NIGHT. ALSO INCREASED POPS
ACROSS SRN PORTIONS OF THE CWA. PRECIP CURRENTLY OVER SW MO
CONTINUES TO MOVE NEWD AND SHUD REACH SRN COUNTIES LATE THIS
EVENING. GOING FORECAST MAY STILL BE TOO SLOW BASED ON LATEST
RADAR TRENDS. HOWEVER...LATEST RAP/HRRR GUIDANCE SUGGESTS FORCING
WILL DIMINISH SOMEWHAT THRU THE NIGHT WITH PRECIP BECOMING MORE
SCT THAN IS CURRENTLY. ANOTHER AREA OF CONCERN IS THE CDFNT MOVING
INTO NWRN MO. GUIDANCE SUGGESTS THIS FNT MAY HELP TO PUSH PRECIP S
OF THE REGION. BELIEVE THE FNT IS MOVING TOO SLOWLY TO HAVE MUCH
IMPACT THIS EVENING...BUT MAY MOVE PRECIP FURTHER S FASTER LATE
TONIGHT. WILL CONTINUE TO MONITOR AND UPDATE AS NEEDED.
TILLY
&&
.SHORT TERM...
ISSUED AT 335 PM CST TUE JAN 8 2013
(TONIGHT)
A NRN STREAM SHORTWAVE WILL PASS NORTH OF THE AREA TONIGHT ALTHOUGH
IT WILL DRAG A WEAK CDFNT THROUGH THE CWA. ATTM NO PCPN IS EXPECTED
WITH THE CDFNT DUE TO THE INITIALLY DRY AIR MASS PER 12Z SGF
SOUNDING...LIMITED MOISTURE ACCOMPANYING THE NRN STREAM
SHORTWAVE...AND UNFAVORABLE DYNAMICS THIS FAR SOUTH OF THE VORT MAX.
THE PRIMARY EFFECT OF THE CDFNT WILL BE TO CAUSE WINDS TO VEER FM
SLY TO WLY OVERNIGHT. ALTHOUGH THE NAM/SREF SEEM TO BE OVERDOING THE
LOW LEVEL MOISTURE BASED ON THE LATEST OBS...MID-LEVEL MOISTURE
SHOULD BEGIN MOVING NWD TONIGHT IN RESPONSE TO A STRONG LOW PRESSURE
SYSTEM IN NRN MEXICO/SRN TX. SOME PCPN HAS ALREADY DVLPD OVER AR
AHEAD OF THE SRN SYSTEM AND IT IS POSSIBLE THAT THERE MAY BE ENOUGH
LIFT TO SUPPORT A FEW SPRINKLES ACROSS THE SRN CWA.
KANOFSKY
&&
.LONG TERM...
ISSUED AT 335 PM CST TUE JAN 8 2013
(WEDNESDAY THROUGH TUESDAY)
A GOOD POTENTIAL FOR SIGNIFICANT QPF IS EXPECTED FOR WED NGT THROUGH
THU NGT AS THE UPPER LEVEL LOW OVER OLD MEXICO MOVES SLOWLY NEWD
THROUGH THE SRN PLAINS WED AND WED NGT...THEN EVENTUALLY MOVES
NEWD THROUGH MO THU NGT. PREFER THE MORE NRN SOLUTION OF THE 500
MB LOW TRACK OF THE NAM AND ECMWF MODELS OVER THE GFS. MOST OF THE
PRECIPITATION SHOULD REMAIN S OF OUR FORECAST AREA ON WED...BUT
THEN SPREAD NEWD INTO MUCH OF THE REGION WED NGT AS A STRONG SLY
LOW LEVEL JET BRINGS LOW LEVEL MOISTURE NWD INTO MUCH OF MO AND
SRN IL. SHOWERS AND AT LEAST A FEW THUNDERSTORMS CAN BE EXPECTED
ON THU AS A WEAK SFC LOW AND WARM FRONT LIFT NWD INTO SRN
MO...WITH INCREASING UPPER LEVEL DIVERGENCE OVER OUR AREA AHEAD OF
THE APPROACHING UPPER LEVEL TROUGH. MUCH OF THE PRECIPITATION
SHOULD SHIFT E OF OUR AREA BY LATE THU NGT AS THE UPPER LEVEL LOW
OPENS UP AND WEAKENS AS IT MOVES TOWARDS THE GREAT LAKES REGION.
UNSEASONABLY WARM WEATHER WILL CONTINUE ON FRI WITH S-SWLY LOW
LEVEL WINDS ALONG WITH A CLEARING SKY. BOTH THE NAM AND ECMWF
MODELS FORECAST 850 MB TEMPERATURES OF AROUND 12 DEGREES C BY 00Z
SAT ACROSS MUCH OF OUR AREA. WILL LIKELY HAVE HIGHS IN THE LOWER
60S ACROSS MOST OF THE AREA ON FRI. SAT WILL BE THE LAST DAY OF
ABOVE NORMAL TEMPERATURES AS A COLD FRONT DROPS SOUTHEASTWARD
THROUGH OUR FORECAST AREA LATE FRI NGT AND SAT. ALTHOUGH THE FRONT
SHOULD MOVE THROUGH DRY THE MODELS DO GENERATE POST FRONTAL
PRECIPITATION SAT NGT AS A WEAK SFC WAVE MOVES ALONG THE FRONT
WITH AN APPROACHING POSITIVELY TILTED UPPER LEVEL TROUGH WELL WEST
OF THE AREA. LOOKS LIKE MOST OF THE PRECIPITATION WILL BE ACROSS
SERN MO AND SWRN IL IN THE WARMER AIR...BUT COULD NOT RULE OUT A
LITTLE LIGHT SNOW N AND W OF STL IN THE COLDER AIR. THE POTENTIAL
FOR AT LEAST LIGHT PRECIPITATION MAY CONTINUE ACROSS SERN MO AND
SWRN IL UNTIL MON WHEN A STRONG SFC RIDGE OVER THE NRN PLAINS
FINALLY BUILDS SEWD INTO MO WITH THE COLD FRONT SHIFTING WELL SE
OF OUR AREA. MUCH COLDER...MORE SEASONAL TEMPERATURES CAN BE
EXPECTED SUN THROUGH TUE.
GKS
&&
.AVIATION...
ISSUED AT 536 PM CST TUE JAN 8 2013
DRY...VFR CONDITIONS WITH ONLY MID AND HIGH LEVEL CLOUDS ARE
EXPECTED THROUGH THE DURATION OF THE FORECAST. PRECIPITATION
MOVING INTO SOUTHERN MISSOURI TONIGHT IS NOT EXPECTED TO IMPACT
THE TERMINALS DUE TO VERY DRY LOW LEVELS AND A LACK OF FORCING
OVER OUR AREA. HOWEVER...RAP AND LOCAL WRF MODEL SOUNDINGS
CONTINUE TO INDICATE THE POTENTIAL FOR LLWS THIS EVENING...AND
THOUGH THE CONDITIONS ARE MARGINAL...HAVE ELECTED TO MENTION FOR
METRO AREA TAF SITES BETWEEN 04-10Z WHERE MODEL SOUNDINGS HAD A
LLJ AROUND 40KT AT 1500FT THIS EVENING. MODELED WINDS ALOFT AT KUIN
AND KCOU APPEARED TO KEEP THOSE SITES BELOW LLWS CRITERIA.
OTHERWISE...SOUTHERLY WINDS WILL GRADUALLY VEER TO THE SOUTHWEST
AHEAD OF A WEAK COLD FRONT PROGGED TO MOVE THROUGH THE
AREA...BECOMING NORTHWESTERLY BY THE END OF THE FORECAST PERIOD.
SPECIFICS FOR KSTL...
DRY...VFR CONDITIONS AND MID TO HIGH LEVEL CLOUDS ARE EXPECTED FOR
THE DURATION OF THE FORECAST. A WEAK COLD FRONT WILL MOVE THROUGH
THE TERMINAL WEDNESDAY MORNING...CAUSING SOUTHERLY WINDS TO VEER
TO THE SOUTHWEST...EVENTUALLY BECOMING NORTHWESTERLY BY THE END
OF THE PERIOD. HAVE GONE WITH A DRY FORECAST ATTM AHEAD OF A
PRECIPITATION EVENT THAT SHOULD IMPACT THE TERMINAL BEGINNING
WEDNESDAY NIGHT...AS IT LOOKS LIKE PRECIPITATION ONSET COULD HOLD
OFF UNTIL AFTER 06Z THURSDAY.
PRIMARY CONCERN THIS FORECAST IS THE POTENTIAL FOR LLWS
TONIGHT...AS LOCAL WRF AND RAP MODEL SOUNDINGS CONTINUE TO
INDICATE A LLJ AROUND 40KT AT 1500FT. THOUGH CONDITIONS ARE
MARGINAL...FELT THE POTENTIAL WAS WORTH MENTIONING...AND THUS HAVE
INCLUDED MENTION OF LLWS FROM 04-10Z TONIGHT.
JP
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
719 PM CST TUE JAN 8 2013
.UPDATE...
ISSUED AT 704 PM CST TUE JAN 8 2013
UPDATE TO INCREASE CLOUDS THRU THE NIGHT. ALSO INCREASED POPS
ACROSS SRN PORTIONS OF THE CWA. PRECIP CURRENTLY OVER SW MO
CONTINUES TO MOVE NEWD AND SHUD REACH SRN COUNTIES LATE THIS
EVENING. GOING FORECAST MAY STILL BE TOO SLOW BASED ON LATEST
RADAR TRENDS. HOWEVER...LATEST RAP/HRRR GUIDANCE SUGGESTS FORCING
WILL DIMINISH SOMEWHAT THRU THE NIGHT WITH PRECIP BECOMING MORE
SCT THAN IS CURRENTLY. ANOTHER AREA OF CONCERN IS THE CDFNT MOVING
INTO NWRN MO. GUIDANCE SUGGESTS THIS FNT MAY HELP TO PUSH PRECIP S
OF THE REGION. BELIEVE THE FNT IS MOVING TOO SLOWLY TO HAVE MUCH
IMPACT THIS EVENING...BUT MAY MOVE PRECIP FURTHER S FASTER LATE
TONIGHT. WILL CONTINUE TO MONITOR AND UPDATE AS NEEDED.
TILLY
&&
.SHORT TERM...
ISSUED AT 335 PM CST TUE JAN 8 2013
(TONIGHT)
A NRN STREAM SHORTWAVE WILL PASS NORTH OF THE AREA TONIGHT ALTHOUGH
IT WILL DRAG A WEAK CDFNT THROUGH THE CWA. ATTM NO PCPN IS EXPECTED
WITH THE CDFNT DUE TO THE INITIALLY DRY AIR MASS PER 12Z SGF
SOUNDING...LIMITED MOISTURE ACCOMPANYING THE NRN STREAM
SHORTWAVE...AND UNFAVORABLE DYNAMICS THIS FAR SOUTH OF THE VORT MAX.
THE PRIMARY EFFECT OF THE CDFNT WILL BE TO CAUSE WINDS TO VEER FM
SLY TO WLY OVERNIGHT. ALTHOUGH THE NAM/SREF SEEM TO BE OVERDOING THE
LOW LEVEL MOISTURE BASED ON THE LATEST OBS...MID-LEVEL MOISTURE
SHOULD BEGIN MOVING NWD TONIGHT IN RESPONSE TO A STRONG LOW PRESSURE
SYSTEM IN NRN MEXICO/SRN TX. SOME PCPN HAS ALREADY DVLPD OVER AR
AHEAD OF THE SRN SYSTEM AND IT IS POSSIBLE THAT THERE MAY BE ENOUGH
LIFT TO SUPPORT A FEW SPRINKLES ACROSS THE SRN CWA.
KANOFSKY
&&
.LONG TERM...
ISSUED AT 335 PM CST TUE JAN 8 2013
(WEDNESDAY THROUGH TUESDAY)
A GOOD POTENTIAL FOR SIGNIFICANT QPF IS EXPECTED FOR WED NGT THROUGH
THU NGT AS THE UPPER LEVEL LOW OVER OLD MEXICO MOVES SLOWLY NEWD
THROUGH THE SRN PLAINS WED AND WED NGT...THEN EVENTUALLY MOVES
NEWD THROUGH MO THU NGT. PREFER THE MORE NRN SOLUTION OF THE 500
MB LOW TRACK OF THE NAM AND ECMWF MODELS OVER THE GFS. MOST OF THE
PRECIPITATION SHOULD REMAIN S OF OUR FORECAST AREA ON WED...BUT
THEN SPREAD NEWD INTO MUCH OF THE REGION WED NGT AS A STRONG SLY
LOW LEVEL JET BRINGS LOW LEVEL MOISTURE NWD INTO MUCH OF MO AND
SRN IL. SHOWERS AND AT LEAST A FEW THUNDERSTORMS CAN BE EXPECTED
ON THU AS A WEAK SFC LOW AND WARM FRONT LIFT NWD INTO SRN
MO...WITH INCREASING UPPER LEVEL DIVERGENCE OVER OUR AREA AHEAD OF
THE APPROACHING UPPER LEVEL TROUGH. MUCH OF THE PRECIPITATION
SHOULD SHIFT E OF OUR AREA BY LATE THU NGT AS THE UPPER LEVEL LOW
OPENS UP AND WEAKENS AS IT MOVES TOWARDS THE GREAT LAKES REGION.
UNSEASONABLY WARM WEATHER WILL CONTINUE ON FRI WITH S-SWLY LOW
LEVEL WINDS ALONG WITH A CLEARING SKY. BOTH THE NAM AND ECMWF
MODELS FORECAST 850 MB TEMPERATURES OF AROUND 12 DEGREES C BY 00Z
SAT ACROSS MUCH OF OUR AREA. WILL LIKELY HAVE HIGHS IN THE LOWER
60S ACROSS MOST OF THE AREA ON FRI. SAT WILL BE THE LAST DAY OF
ABOVE NORMAL TEMPERATURES AS A COLD FRONT DROPS SOUTHEASTWARD
THROUGH OUR FORECAST AREA LATE FRI NGT AND SAT. ALTHOUGH THE FRONT
SHOULD MOVE THROUGH DRY THE MODELS DO GENERATE POST FRONTAL
PRECIPITATION SAT NGT AS A WEAK SFC WAVE MOVES ALONG THE FRONT
WITH AN APPROACHING POSITIVELY TILTED UPPER LEVEL TROUGH WELL WEST
OF THE AREA. LOOKS LIKE MOST OF THE PRECIPITATION WILL BE ACROSS
SERN MO AND SWRN IL IN THE WARMER AIR...BUT COULD NOT RULE OUT A
LITTLE LIGHT SNOW N AND W OF STL IN THE COLDER AIR. THE POTENTIAL
FOR AT LEAST LIGHT PRECIPITATION MAY CONTINUE ACROSS SERN MO AND
SWRN IL UNTIL MON WHEN A STRONG SFC RIDGE OVER THE NRN PLAINS
FINALLY BUILDS SEWD INTO MO WITH THE COLD FRONT SHIFTING WELL SE
OF OUR AREA. MUCH COLDER...MORE SEASONAL TEMPERATURES CAN BE
EXPECTED SUN THROUGH TUE.
GKS
&&
.AVIATION...
ISSUED AT 536 PM CST TUE JAN 8 2013
DRY...VFR CONDITIONS WITH ONLY MID AND HIGH LEVEL CLOUDS ARE
EXPECTED THROUGH THE DURATION OF THE FORECAST. PRECIPITATION
MOVING INTO SOUTHERN MISSOURI TONIGHT IS NOT EXPECTED TO IMPACT
THE TERMINALS DUE TO VERY DRY LOW LEVELS AND A LACK OF FORCING
OVER OUR AREA. HOWEVER...RAP AND LOCAL WRF MODEL SOUNDINGS
CONTINUE TO INDICATE THE POTENTIAL FOR LLWS THIS EVENING...AND
THOUGH THE CONDITIONS ARE MARGINAL...HAVE ELECTED TO MENTION FOR
METRO AREA TAF SITES BETWEEN 04-10Z WHERE MODEL SOUNDINGS HAD A
LLJ AROUND 40KT AT 1500FT THIS EVENING. MODELED WINDS ALOFT AT KUIN
AND KCOU APPEARED TO KEEP THOSE SITES BELOW LLWS CRITERIA.
OTHERWISE...SOUTHERLY WINDS WILL GRADUALLY VEER TO THE SOUTHWEST
AHEAD OF A WEAK COLD FRONT PROGGED TO MOVE THROUGH THE
AREA...BECOMING NORTHWESTERLY BY THE END OF THE FORECAST PERIOD.
SPECIFICS FOR KSTL...
DRY...VFR CONDITIONS AND MID TO HIGH LEVEL CLOUDS ARE EXPECTED FOR
THE DURATION OF THE FORECAST. A WEAK COLD FRONT WILL MOVE THROUGH
THE TERMINAL WEDNESDAY MORNING...CAUSING SOUTHERLY WINDS TO VEER
TO THE SOUTHWEST...EVENTUALLY BECOMING NORTHWESTERLY BY THE END
OF THE PERIOD. HAVE GONE WITH A DRY FORECAST ATTM AHEAD OF A
PRECIPITATION EVENT THAT SHOULD IMPACT THE TERMINAL BEGINNING
WEDNESDAY NIGHT...AS IT LOOKS LIKE PRECIPITATION ONSET COULD HOLD
OFF UNTIL AFTER 06Z THURSDAY.
PRIMARY CONCERN THIS FORECAST IS THE POTENTIAL FOR LLWS
TONIGHT...AS LOCAL WRF AND RAP MODEL SOUNDINGS CONTINUE TO
INDICATE A LLJ AROUND 40KT AT 1500FT. THOUGH CONDITIONS ARE
MARGINAL...FELT THE POTENTIAL WAS WORTH MENTIONING...AND THUS HAVE
INCLUDED MENTION OF LLWS FROM 04-10Z TONIGHT.
JP
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
552 PM CST TUE JAN 8 2013
.SHORT TERM...
ISSUED AT 335 PM CST TUE JAN 8 2013
(TONIGHT)
A NRN STREAM SHORTWAVE WILL PASS NORTH OF THE AREA TONIGHT ALTHOUGH
IT WILL DRAG A WEAK CDFNT THROUGH THE CWA. ATTM NO PCPN IS EXPECTED
WITH THE CDFNT DUE TO THE INITIALLY DRY AIR MASS PER 12Z SGF
SOUNDING...LIMITED MOISTURE ACCOMPANYING THE NRN STREAM
SHORTWAVE...AND UNFAVORABLE DYNAMICS THIS FAR SOUTH OF THE VORT MAX.
THE PRIMARY EFFECT OF THE CDFNT WILL BE TO CAUSE WINDS TO VEER FM
SLY TO WLY OVERNIGHT. ALTHOUGH THE NAM/SREF SEEM TO BE OVERDOING THE
LOW LEVEL MOISTURE BASED ON THE LATEST OBS...MID-LEVEL MOISTURE
SHOULD BEGIN MOVING NWD TONIGHT IN RESPONSE TO A STRONG LOW PRESSURE
SYSTEM IN NRN MEXICO/SRN TX. SOME PCPN HAS ALREADY DVLPD OVER AR
AHEAD OF THE SRN SYSTEM AND IT IS POSSIBLE THAT THERE MAY BE ENOUGH
LIFT TO SUPPORT A FEW SPRINKLES ACROSS THE SRN CWA.
KANOFSKY
&&
.LONG TERM...
ISSUED AT 335 PM CST TUE JAN 8 2013
(WEDNESDAY THROUGH TUESDAY)
A GOOD POTENTIAL FOR SIGNIFICANT QPF IS EXPECTED FOR WED NGT THROUGH
THU NGT AS THE UPPER LEVEL LOW OVER OLD MEXICO MOVES SLOWLY NEWD
THROUGH THE SRN PLAINS WED AND WED NGT...THEN EVENTUALLY MOVES
NEWD THROUGH MO THU NGT. PREFER THE MORE NRN SOLUTION OF THE 500
MB LOW TRACK OF THE NAM AND ECMWF MODELS OVER THE GFS. MOST OF THE
PRECIPITATION SHOULD REMAIN S OF OUR FORECAST AREA ON WED...BUT
THEN SPREAD NEWD INTO MUCH OF THE REGION WED NGT AS A STRONG SLY
LOW LEVEL JET BRINGS LOW LEVEL MOISTURE NWD INTO MUCH OF MO AND
SRN IL. SHOWERS AND AT LEAST A FEW THUNDERSTORMS CAN BE EXPECTED
ON THU AS A WEAK SFC LOW AND WARM FRONT LIFT NWD INTO SRN
MO...WITH INCREASING UPPER LEVEL DIVERGENCE OVER OUR AREA AHEAD OF
THE APPROACHING UPPER LEVEL TROUGH. MUCH OF THE PRECIPITATION
SHOULD SHIFT E OF OUR AREA BY LATE THU NGT AS THE UPPER LEVEL LOW
OPENS UP AND WEAKENS AS IT MOVES TOWARDS THE GREAT LAKES REGION.
UNSEASONABLY WARM WEATHER WILL CONTINUE ON FRI WITH S-SWLY LOW
LEVEL WINDS ALONG WITH A CLEARING SKY. BOTH THE NAM AND ECMWF
MODELS FORECAST 850 MB TEMPERATURES OF AROUND 12 DEGREES C BY 00Z
SAT ACROSS MUCH OF OUR AREA. WILL LIKELY HAVE HIGHS IN THE LOWER
60S ACROSS MOST OF THE AREA ON FRI. SAT WILL BE THE LAST DAY OF
ABOVE NORMAL TEMPERATURES AS A COLD FRONT DROPS SOUTHEASTWARD
THROUGH OUR FORECAST AREA LATE FRI NGT AND SAT. ALTHOUGH THE FRONT
SHOULD MOVE THROUGH DRY THE MODELS DO GENERATE POST FRONTAL
PRECIPITATION SAT NGT AS A WEAK SFC WAVE MOVES ALONG THE FRONT
WITH AN APPROACHING POSITIVELY TILTED UPPER LEVEL TROUGH WELL WEST
OF THE AREA. LOOKS LIKE MOST OF THE PRECIPITATION WILL BE ACROSS
SERN MO AND SWRN IL IN THE WARMER AIR...BUT COULD NOT RULE OUT A
LITTLE LIGHT SNOW N AND W OF STL IN THE COLDER AIR. THE POTENTIAL
FOR AT LEAST LIGHT PRECIPITATION MAY CONTINUE ACROSS SERN MO AND
SWRN IL UNTIL MON WHEN A STRONG SFC RIDGE OVER THE NRN PLAINS
FINALLY BUILDS SEWD INTO MO WITH THE COLD FRONT SHIFTING WELL SE
OF OUR AREA. MUCH COLDER...MORE SEASONAL TEMPERATURES CAN BE
EXPECTED SUN THROUGH TUE.
GKS
&&
.AVIATION...
ISSUED AT 536 PM CST TUE JAN 8 2013
DRY...VFR CONDITIONS WITH ONLY MID AND HIGH LEVEL CLOUDS ARE
EXPECTED THROUGH THE DURATION OF THE FORECAST. PRECIPITATION
MOVING INTO SOUTHERN MISSOURI TONIGHT IS NOT EXPECTED TO IMPACT
THE TERMINALS DUE TO VERY DRY LOW LEVELS AND A LACK OF FORCING
OVER OUR AREA. HOWEVER...RAP AND LOCAL WRF MODEL SOUNDINGS
CONTINUE TO INDICATE THE POTENTIAL FOR LLWS THIS EVENING...AND
THOUGH THE CONDITIONS ARE MARGINAL...HAVE ELECTED TO MENTION FOR
METRO AREA TAF SITES BETWEEN 04-10Z WHERE MODEL SOUNDINGS HAD A
LLJ AROUND 40KT AT 1500FT THIS EVENING. MODELED WINDS ALOFT AT KUIN
AND KCOU APPEARED TO KEEP THOSE SITES BELOW LLWS CRITERIA.
OTHERWISE...SOUTHERLY WINDS WILL GRADUALLY VEER TO THE SOUTHWEST
AHEAD OF A WEAK COLD FRONT PROGGED TO MOVE THROUGH THE
AREA...BECOMING NORTHWESTERLY BY THE END OF THE FORECAST PERIOD.
SPECIFICS FOR KSTL...
DRY...VFR CONDITIONS AND MID TO HIGH LEVEL CLOUDS ARE EXPECTED FOR
THE DURATION OF THE FORECAST. A WEAK COLD FRONT WILL MOVE THROUGH
THE TERMINAL WEDNESDAY MORNING...CAUSING SOUTHERLY WINDS TO VEER
TO THE SOUTHWEST...EVENTUALLY BECOMING NORTHWESTERLY BY THE END
OF THE PERIOD. HAVE GONE WITH A DRY FORECAST ATTM AHEAD OF A
PRECIPITATION EVENT THAT SHOULD IMPACT THE TERMINAL BEGINNING
WEDNESDAY NIGHT...AS IT LOOKS LIKE PRECIPITATION ONSET COULD HOLD
OFF UNTIL AFTER 06Z THURSDAY.
PRIMARY CONCERN THIS FORECAST IS THE POTENTIAL FOR LLWS
TONIGHT...AS LOCAL WRF AND RAP MODEL SOUNDINGS CONTINUE TO
INDICATE A LLJ AROUND 40KT AT 1500FT. THOUGH CONDITIONS ARE
MARGINAL...FELT THE POTENTIAL WAS WORTH MENTIONING...AND THUS HAVE
INCLUDED MENTION OF LLWS FROM 04-10Z TONIGHT.
JP
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
234 PM CST MON JAN 7 2013
.SHORT TERM...TONIGHT THROUGH THURSDAY.
MAIN FORECAST CONCERNS WILL DEAL WITH TEMPERATURES AND TIMING OF
SYSTEM MOVING OUT OF THE SOUTHERN PLAINS WEDNESDAY NIGHT INTO
THURSDAY.
DESPITE THICK CIRRUS LAYER ACROSS PARTS OF THE AREA AND LIGHT
SURFACE WINDS ALONG A WEAK TROUGH INTO EAST CENTRAL NEBRASKA...
TEMPERATURES HAVE MANAGED TO CLIMB INTO THE MID AND UPPER 30S IN
SNOW COVERED PORTION OF THE CWA WITH MID 40S TO LOWER 50S IN SNOW
FREE PARTS OF SOUTHEAST NEBRASKA AND SOUTHWEST IOWA THIS AFTERNOON.
INITIAL CONCERN FOR TONIGHT WILL BE POTENTIAL FOG DEVELOPMENT IN
THE SNOW AREAS WHERE SOME MELTING TODAY HAS ADDED MOISTURE TO THE
BOUNDARY LAYER. SHORT RANGE RAP HINTS AT DEVELOPMENT AFTER 06Z IN
AREA WHERE MENTION OF PATCHY FOG IS ALREADY IN CURRENT FORECAST.
FOR TUESDAY AND WEDNESDAY QUESTION WILL BE HOW WARM WILL
TEMPERATURES BE ABLE TO REACH. BASED ON TODAYS READINGS CLIMBING
TO AROUND 50 IN THE SOUTHEAST PART OF THE CWA...HAVE WENT A
WARMER THAN GUIDANCE IN THE SNOW FREE AREAS WITH SNOW FIELD STILL
EXPECTED TO KEEP TEMPERATURES TO THE NORTH CLOSE TO GUIDANCE.
TIMING ISSUES AMONG THE MODELS STILL IN PLAY FOR WEDNESDAY NIGHT
AND THURSDAY WITH NAM THE FASTEST AND LEAST REGARDED AT THIS TIME
FRAME. GFS AND EURO HAVE BETTER AGREEMENT BUT EURO REMAINS SLOWER
IN MOVING THE SYSTEM ACROSS THE AREA. FORECAST SOUNDINGS FOR
WEDNESDAY NIGHT SUGGEST TEMPERATURES SHOULD BE WARM ENOUGH ACROSS
THE SOUTH HALF OF THE AREA FOR PRECIP TO BE ALL LIQUID WITH
TEMPERATURES REMAINING ABOVE FREEZING ON THURSDAY ACROSS ALL THE
AREA AS RAIN CONTINUES.
.LONG TERM...THURSDAY NIGHT THROUGH MONDAY.
THE GFS AND ECM ARE IN RELATIVELY GOOD AGREEMENT WITH REGARDS TO
LARGE SCALE IN THE EXTENDED PD. BOTH ALSO SUGGESTING LITTLE CHANGE
NEEDED TO GOING FCST.
HEADING INTO NEXT WEEKEND...MODELS ADVERTISE SHORTWAVE ENERGY OVER
IA QUICKLY LIFTING TO THE GREAT LAKES REGION LATE THURSDAY NIGHT.
MEANWHILE UPSTREAM...A DEEP LONGWAVE TROF IS PROGGED TO EXTEND FROM
CNTRL CANADA ALL THE WAY TO THE SWRN CONUS. ON FRIDAY AS THE WRN
TROF GRADUALLY MIGRATES EAST...INTENSE BAROCLINIC ZONE BEGINS
SWEEPING ACROSS THE NRN/CNTRL PLAINS WITH THE LEADING EDGE OF THE
BOUNDARY REACHING THE CWA BY EARLY AFTN. COMBINATION OF INCREASING
MOISTURE AND STOUT AGEOSTROPHIC LIFT ALONG DEEP FRONTOGENETIC LYR
SHOULD BE ENOUGH TO INDUCE LIGHT SNOW ACTIVITY DURING THE FROPA
FRIDAY NIGHT.
ON SATURDAY...APPEARS TO BE A SMALL CHANCE FOR LIGHT POST-FRONTAL
SNOW ACTIVITY PER THE ECM. 300-500MB QVEC CONVERGENCE IMPLYING LIFT
VIA DPVA WHEN POTENT OR MAX ROUNDS THE BASE OF THE WRN TROF AND
LIFTS ACROSS THE CNTRL PLAINS. ON THE OTHER HAND...GFS AND CMC BOTH
SUGGESTING THE DEEP CAA WILL BE ADEQUATE TO SUPPRESS ANY LIFT VIA
DPVA. WILL OPTED FOR TOKEN 20S JUST IN CASE ECM SOLUTION WOULD
VERIFY.
OTHERWISE...TEMPS WILL PLUMMETS OVER THE PLAINS NEXT WEEKEND INTO
EARLY NEXT WEEK. EXPECT HIGHS SAT-MON WILL STRUGGLE TO REACH THE
LOW/MID 20S.
&&
.AVIATION...
18Z TAFS FOR KOFK...KOMA AND KLNK.
VFR CONDITIONS WERE FORECAST AT TAF SITES AS A WIND SHIFT BRINGS
A WEAKENING SURFACE GRADIENT. HOWEVER...IF HIGH CLOUDS CLEAR
MARKEDLY TONIGHT AND DEW POINT TEMPERATURES INCREASE A BIT MORE
THAN EXPECTED...FOG AND STRATUS COULD POSSIBLY DEVELOP OVER SNOW
AREA WHICH COULD IMPACT LNK/OMA TAF SITES TUESDAY MORNING. THIS
THREAT WILL BE ASSESSED IN FUTURE FORECASTS.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
FOBERT/DEE/CHERMOK
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
922 PM CST TUE JAN 8 2013
.DISCUSSION...
SFC OBS SHOW THE MAIN SFC TROUGH NOW MOVING THROUGH THE RED RIVER
VALLEY. WATER VAPOR SHOWS UPPER LOW AND SFC LOW NORTHWEST OF
WINNIPEG AND A SURGE OF CLOUDS AND WINDS ON THE BACKSIDE OF THE
LOW MOVING FROM REGINA AREA WHERE IT WAS LATE THIS AFTN THEN INTO
NW ND 00Z-01Z...THEN NOW MOVING THRU RUGBY-ROLLA AT 02-03Z. THIS
SURGE OF CLOUDS ROTATING EAST-SOUTHEAST AROUND THE LOW IN MANITOBA
WILL CONTINUE TO MOVE INTO NE ND/NRN RRV THRU 06Z. NAM 3 HR
PRESSURE RISES SHOWS A HEALTHY 5 MB/3 HR PRESSURE RISE INTO NE ND
06Z-09Z PERIOD AND 1000-850 MB LOW LEVEL LAPSE RATES DECENT (7 TO
8C/KM) MOVING THRU AS WELL. THIS IS ENOUGH FOR A 3-4 HR PERIOD OF
GOOD MIXING OF THE 45-50 KTS 925-850 MB LAYER. SEEING WIND GUSTS
TO 40 KTS OR HIGHER AT KMIB...CYBR AND NR THAT AT KRUG (RUGBY). DO
EXPECT THIS PERIOD OF WIND GUSTS TO NR 40 KTS TO SPREAD EAST
THE NEXT FEW HOURS. DUE TO RATHER SHORT NATURE OF EVENT AND ALSO
BECAUSE IT IS CAUSING SLICK ROADS DUE TO DRIFTING...COORD WITH WFO
BIS AND ISSUED A SPECIAL WX STATEMENT FOR AREAS ALONG AND NORTH OF
COOPERSTOWN-HILLSBORO LINE.
OTHERWISE...TEMPS STILL MILD BUT WILL FALL OFF LATER AS COOLER AIR
MOVES IN WITH STRATOCU. LATEST RAP AND 00Z NAM ALL SHOW CLEARING
MOVING BACK IN BEHIND CLOUDS INTO NE ND TOWARD 12Z. CLOUDS TO
CLEAR OUT OF NW MN MORE TOWARD 15Z WED.
&&
.AVIATION....WIND GUSTS COMING NOW AND WILL BE WITH US THRU THE
NIGHT IN DVL/GFK/FAR/TVF SITES....SPREADING FROM WEST TO EAST.
HIGHEST WINDS LIKELY AT DVL 04Z-07Z WITH NR 40 KTS FROM WEST-
NORTHWEST DIRECTION. WINDS WILL DIMINISH BY 12Z. CLOUDS MOVING IN
AFTER CLEARING MOSTLY IN THE MVFR RANGE AND THESE SHOULD CLEAR OUT
OF NE ND 11Z-14Z PERIOD.
&&
.PREV DISCUSSION... /ISSUED 300 PM CST TUE JAN 8 2013/
SHORT TERM...
MAIN FORECAST HEADACHES FOR THE PERIOD WILL BE ENDING OF PRECIP
ALONG WITH WINDS TONIGHT...AND THEN WHAT HAPPENS WITH THE SYSTEM
COMING IN THURSDAY/FRIDAY.
AN UPPER LOW CURRENTLY ROTATING ALONG THE SASKATCHEWAN/MANITOBA
BORDER WILL CONTINUE EASTWARD INTO ONTARIO TONIGHT. THE SFC LOW
WILL MOVE EASTWARD ALSO...BRINGING A STRONG GRADIENT WITH WEST
WINDS. DEFORMATION BANDS THAT ARE CURRENTLY PRODUCING SNOW OVER
THE RED RIVER VALLEY AND POINTS EASTWARD WILL CONTINUE TO MOVE
EAST THIS EVENING. WILL MAKE LAST MINUTE ADJUSTMENTS FOR GOING
RADAR TRENDS...BUT FOR NOW WILL KEEP HIGH POPS OVER ONLY THE
NORTHEASTERN CWA THIS EVENING. SOME OF THE MODELS SHOW SIGNS OF
SOME WRAP AROUND SNOW SHOWERS TOWARDS MORNING SO KEPT THE 20 POPS
GOING IN THAT AREA AFTER MIDNIGHT.
ANOTHER ISSUE TONIGHT WILL BE WINDS. A FEW OF THE MODELS HAVE
VALUES APPROACHING WIND ADVISORY CRITERIA...PARTICULARLY OVER THE
DEVILS LAKE BASIN DURING THE 00Z TO 06Z TIME FRAME. ON ONE HAND
THERE WILL BE A FAIRLY TIGHT PRESSURE GRADIENT AND DECENT
SUBSIDENCE ON THE BACK SIDE OF THE DEPARTING LOW. ON THE OTHER
HAND...THE BEST WINDS ALOFT WILL BE COMING THROUGH DURING A PERIOD
WITH NOT MUCH MIXING...AND COLD AIR ADVECTION IS NOT AS STRONG AS
IT COULD BE. WILL MONITOR OBS DURING THE NEXT HOUR OR SO...BUT FOR
NOW WILL KEEP WINDS SUB ADVISORY CRITERIA BUT MENTION BLOWING SNOW
IN THE NORTHWEST PORTION OF THE CWA.
TOMORROW SHOULD BE FAIRLY QUIET AS UPPER RIDGING BRIEFLY BUILDS
INTO THE PLAINS. ANOTHER SFC LOW WILL DEVELOP OVER
SASKATCHEWAN...WITH SOUTHERLY WINDS AND WARM AIR ADVECTION KICKING
IN BY AFTERNOON. AIR MASS WILL CONTINUE TO BE FAIRLY MILD SO KEPT
HIGHS IN THE 20S. TEMPS SHOULD REMAIN FAIRLY WARM THROUGH
WEDNESDAY NIGHT AS SOUTHERLY WINDS PICK UP AS THE SFC TROUGH OVER
SOUTH CENTRAL CANADA DEEPENS. MODELS BRING IN SOME VERY WARM AIR
AT 850MB...UP CLOSE TO 10 C OVER THE SOUTHERN CWA. EVEN WITH A
FAIRLY LARGE INVERSION TEMPS WEDNESDAY NIGHT SHOULD STAY IN THE
UPPER TEENS TO LOW 20S.
THE NEXT QUESTION IS WHAT WILL HAPPEN WITH THE SYSTEMS COMING
THROUGH THURSDAY/FRIDAY. THE MODELS ALL ARE IN FAIRLY GOOD
AGREEMENT ON THE GENERAL PATTERN...BRINGING AN UPPER LOW FROM
TX/OK INTO THE UPPER MIDWEST AND THEN A LARGER TROUGH INTO THE
WESTERN PLAINS BY FRIDAY. HOWEVER...AS FAR AS SPEED AND WHEN
PRECIP STARTS MOVING INTO THE AREA MODEL SOLUTIONS ARE ALL OVER
THE PLACE. THE NAM IS FASTEST AND HAS PRECIP ENTERING THE
SOUTHEASTERN CWA BY THURSDAY AFTERNOON...WHILE THE GFS IS MUCH
SLOWER WITH THE SOUTHERN SYSTEM AND DOESN`T BRING PRECIP INTO THAT
AREA UNTIL LATE THURSDAY NIGHT INTO FRIDAY MORNING. THE NAM IS AN
OUTLIER BUT THE GFS SEEMS A BIT SLOW...SO LEANED MORE TOWARDS A
MIDDLE OF THE ROAD ECMWF/GEM SOLUTION. KEPT POPS VERY LOW BEFORE
00Z FRIDAY WITH INCREASING CHANCES THROUGHOUT THE NIGHT. WITH
FAIRLY WARM TEMPS IN PLACE AS THE SYSTEM ARRIVES...SOME
RAIN/FREEZING RAIN IS A POSSIBILITY IN THE SOUTHEASTERN CWA AS THE
PRECIP BEGINS. THINK THAT PRECIP SHOULD CHANGE OVER TO SNOW ON
FRIDAY AS A STRONG COLD FRONT BEGINS TO SLOWLY PUSH INTO THE AREA.
KEPT POPS IN THE HIGH CHANCE CATEGORY FOR FRIDAY GIVEN FAIRLY HIGH
UNCERTAINTY BUT LATER SHIFTS WILL HAVE TO REEVALUATE. FRIDAY
COULD SEE FALLING TEMPS IN THE AFTERNOON AS COLD AIR CONTINUES TO
PUSH INTO THE NORTHERN PLAINS.
LONG TERM (FRI NIGHT THRU TUE)...
MAJOR LONG RANGE GUIDANCE IN AGREEMENT DEPICTING SOUTHWEST FLOW AT
BEGINNING OF PERIOD MOVING A COLORADO SURFACE CYCLONE TO THE
VICINITY OF NORTHERN MINNESOTA/WISCONSIN EARLY SATURDAY. COLDER AIR
WILL BE IN PLACE IN THE WAKE OF THE EARLIER WARMUP...THIS IN TANDEM
WITH H500/H700 LOWS PROXIMAL TO THE RED RIVER VALLEY WOULD PORTEND A
MEASURABLE SNOW EVENT FROM LATE FRIDAY INTO THE FIRST PART OF
SATURDAY. LONG WAVE UPPER TROUGH LAGGING BEHIND THIS SYSTEM WILL
SWING THROUGH LATER IN THE WEEKEND BRINGING DOWN ARCTIC AIR AS
NORTHWEST FLOW ESTABLISHES ITSELF EARLY NEXT WEEK. LOWERED ALL BLEND
TEMPS JUST A TAD DURING THIS PERIOD IN AN ATTEMPT TO ACCOUNT FOR
SEVERAL INCHES OF PRISTINE SNOWFALL.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
RIDDLE/JR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
641 AM EST MON JAN 7 2013
.SYNOPSIS...
HIGH PRESSURE WILL DOMINATE THE REGIONAL PATTERN THROUGH MID-
WEEK...BRINGING DRY AND TRANQUIL WEATHER CONDITIONS TO THE AREA.
A RELATIVELY MILD SOUTHWEST RETURN FLOW SHOULD ALLOW TEMPERATURES
TO MODERATE WELL-ABOVE SEASONAL CLIMATE NORMALS BY WEDNESDAY AND
THURSDAY. THE NEXT CHANCE FOR PRECIPITATION WILL COME BY THE END
OF THE WEEK...AS LOW PRESSURE MOVES INTO THE GREAT LAKES REGION.
&&
.NEAR TERM /UNTIL NOON TODAY/...
12Z UPDATE...
VERY MINOR CHANGES MADE TO SIG WX ELEMENTS WITH THE EARLY MORNING
UPDATE. ISSUED SPS TO COVER PATCHY -FZDZ AND POTNL ICY ROAD
THREAT OVER THE ALLEGHENIES. OTHERWISE...STILL LIKE THE IDEA OF
SLOW...GRADUAL CLEARING WITH PLENTY OF RESIDUAL LLVL MSTR/LOW
CLOUDS STILL COVERING NEARLY THE ENTIRE CWA PER IR SATL LOOP. TEMPS
HAVE REMAINED RELATIVELY WARM OVERNIGHT...AND WITH THE AFOREMENTIONED
CLOUDS NOT EXPECTING A HUGE REBOUND THIS AFTN.
PREVIOUS DISCUSSION FROM 321 AM...
EXTENSIVE LOW-LEVEL MSTR/CLOUD COVER IN THE WAKE OF A NEBULOUS
SFC LOW MOVG AWAY FROM NRN NEW ENGLAND WILL PERSIST ACRS MUCH OF
WESTERN AND CENTRAL PA THIS MORNING...AS UPSLOPE WLY FLOW
CONTINUES TO PROVIDE SUFFICIENT /ALBEIT WEAK/ OROGRAPHIC LIFT OVER
THE ALLEGHENIES. REGIONAL RADAR MOSAIC ALSO INDICATES SOME LGT
PCPN ACRS THE WRN AND NRN MTNS...EITHER IN THE FORM OF -SN OR
PATCHY -FZDZ. THE RAP AND 4KM NAM FCST SOUNDINGS FAVOR -FZDZ
PROFILES THRU THE PRE DAWN HOURS AS MID-LVL MSTR IS STRIPPED AWAY.
THE CLOUD COVER AND STEADY 5-10KT WNW WIND WILL KEEP TEMPS IN
THE UPPER 20S TO MID 30S. LOW CLOUDS WILL LKLY BE SLOW TO ERODE
AFT SUNRISE ESP IN THE WRN MTNS AS LOW-LEVEL MSTR GETS TRAPPED
UNDER SFC RIDGE MOVG EWD FM THE OH VLY. HOWEVER ANTICIPATE SOME
BINOVC E OF THE MTNS.
&&
.SHORT TERM /NOON TODAY THROUGH 6 AM TUESDAY/...
LG SCALE SUBSIDENCE ASSOC WITH THE AFOREMENTIONED SFC HIGH AND
BACKING LLVL FLOW /TO THE SSW/ SHOULD AFFORD MORE PEAKS OF SUN AS
THE DAY WEARS ON. HIGHS SHOULD CLIMB A FEW DEGS ABOVE EARLY
JANUARY CLIMATE NORMALS...RANGING FROM THE LOW-MID 30S OVER THE
ALLEGHENIES TO THE LOW 40S OVER THE LWR SUSQ VLY. EXPECT MAINLY
CLR SKIES OVERNIGHT AS THE RIDGE MOVES OVER THE AREA...WITH LOWS
VARYING FROM THE UPPER TEENS TO MID 20S.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
MODERATELY AMPLIFIED SPLIT FLOW PATTERN WILL PREVAIL THROUGH THE
UPCOMING WORKWEEK...WITH THE NORTHERN STREAM TAPPING MAINLY PACIFIC
AIR THROUGH THE PERIOD.
EARLY IN THE PERIOD...A RIDGE OF SFC HIGH PRESSURE WILL EXTEND FROM
THE WESTERN ATLANTIC TO THE VIRGINIAS...WITH A DEVELOPING SWRLY FLOW
AND ABUNDANT SUNSHINE TEAMING UP TO BOOST TEMPS SOME 7-10F ABOVE
NORMAL. POPS WILL BE ZERO FOR THE DAY TUESDAY.
FOR TUESDAY NIGHT AND WEDNESDAY...A WELL DEFINED AND FAST MOVING NRN
STREAM SHORTWAVE WILL TRACK FROM THE UPPER GLAKES...TO THE NERN U.S.
BY 00Z THUR. BROAD...UPPER DIFFLUENT FLOW BETWEEN TWO DISTINCT 300
MB JET MAXES IN EXCESS OF 100 KTS AND A BRIEF PUSH OF NEAR 0.50 INCH
PWATS WILL BRING JUST A FEW TO SVRL HOUR PERIOD LAYERED BROKEN CLOUD
COVER AND PERHAPS A FEW SPRINKLES...OR BRIEF LIGHT RAIN/SNOW SHOWERS
ACROSS THE WRN MTNS DURING THE EARLY TO MID MORNING HOURS WEDNESDAY
/INVOF OF A MOISTURE CHALLENGED WARM FRONT/.
FAIRLY STRONG SUBSIDENCE IN THE WARM SECTOR WILL FOLLOW FOR THE
MIDDAY AND AFTERNOON HOURS WEDNESDAY...BENEATH THE THERMALLY
INDIRECT RIGHT EXIT REGION OF A 150 KT UPPER JET STREAK CROSSING NEW
YORK STATE. PARTLY TO MOSTLY SUNNY SKIES FOR WEDNESDAY AFTERNOON
WILL BOOST TEMPS FURTHER /BY ABOUT 5 DEG F HIGHER THAN TUESDAY/.
HIGHS WED AFTN WILL VARY FROM THE LOWER 40S ACROSS THE NW MTNS TO
THE LOWER 50S IN SOME OF THE SOUTHERN VALLEYS. THESE READINGS WILL
BE ROUGHLY 10-15F ABOVE NORMAL...WITH THE GREATER DEPARTURES
OCCURRING ACROSS THE MTNS.
WESTERLY WINDS WILL QUICKLY INCREASE WEDNESDAY MORNING...AND WILL
LIKELY GUST BETWEEN 30-35 MPH AT TIMES IN THE AFTERNOON /ESPECIALLY
ACROSS THE HIGHER TERRAIN OF THE NORTH AND WEST/.
A BRIEF SHOT OF SLIGHTLY COOLER AIR FOLLOWS THE EXIT OF THIS NRN
STREAM WAVE WEDNESDAY NIGHT. AS WINDS DIMINISH QUICKLY IN THE
EVENING AND SKIES STAY MAINLY CLEAR...TEMPS WILL FALL TO AROUND 20F
ACROSS THE NRN MTNS /WHERE THE DEEPEST SNOW COVER WILL REMAIN/ TO
NEAR 30F IN THE SOUTHEAST.
SFC HIGH WILL BE CENTERED ACROSS WRN PENN TO START THE DAY
THURSDAY...AND WILL SLIDE EAST ACROSS THE COMMONWEALTH DURING THE
AFTERNOON. A SLOW MOVING...CLOSED UPPER LOW IMPACTING FAR WEST TEXAS
EARLY IN THE WEEK WILL LIFT NE WED AND THURSDAY...AS AN OPENING WAVE
IN THE AMPLIFYING SWRLY FLOW ACROSS THE MIDWEST AND GLAKES REGION.
INCREASING DEEP-LAYER WARM ADVECTION AHEAD OF THIS SYSTEM LATE
THURSDAY INTO EARLY FRIDAY WILL BRING THICKENING CLOUDS AND HIGH CHC
TO LOW LIKELY POPS FOR RAIN SHOWERS. THE VERY DRY LLVLS COULD COOL
TO JUST BELOW FREEZING AS THE PRECIP SPREADS NE THURSDAY
NIGHT...POSSIBLY LEADING TO SOME SPOTTY LIGHT MIXED PRECIP...MAINLY
TO THE NORTH AND EAST OF KIPT WHERE A FEW HOURS OF CLEARING ARE
POSSIBLE DURING THE EVENING HOURS.
IN THE WAKE OF THIS MINOR PRECIP EVENT AND SOME ADDITIONAL
SNOWMELT/RUNOFF...TEMPS WILL SLOWLY RISE TO EVEN GREATER DEPARTURES
FROM NORMAL AS A VERY ANOMALOUS UPPER RIDGE OF PLUS 2-3 ST
DEVIATIONS AMPLIFIES ACROSS THE GLAKES...EAST THROUGH THE NE U.S.
AND SERN CANADA.
HIGH TEMPS BY SATURDAY COULD BE EASILY 15-20F ABOVE NORMAL ACROSS
THE CENTRAL AND SRN PORTIONS OF THE CWA...WITH MAXES RANGING FROM
THE MID 40S IN THE NORTH...TO LOWER AND MID 50S THROUGHOUT SOUTHERN
PENN.
INCREASING CHCS FOR RAIN WILL DEVELOP FOR THE SECOND HALF OF THE
WEEKEND AS A SLOW MOVING COLD FRONT PRESSES EAST TWD THE REGION AND
ONE OR MORE WAVES OF SFC LOW PRESSURE RIDE NEWD ALONG IT.
A BIG PATTERN CHANGE IS LIKELY THE FOLLOWING WEEK AS SIGNIFICANT
RIDGING DEVELOPS ACROSS THE EASTERN PACIFIC AND ALLOWS A LARGE AREA
OF ARCTIC AIR TO SURGE SE INTO THE NRN ROCKIES AND UPPER MID VALLEY
MONDAY AND TUESDAY...WITH COOLER AIR OOZING INTO THE MIDDLE ATLANTIC
AND LOWER GLAKES REGION.
THE NEXT POTENTIAL WINTRY /OR SIGNIFICANT RAIN EVENT/ WILL LIKELY BE
NEXT TUESDAY INTO WEDNESDAY AS THE NRN AND SRN STREAM PHASES INTO A
HIGH AMPLITUDE TROUGH FROM THE UPPER GLAKES...SWD TO THE LOWER MISS
VALLEY.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
SHALLOW MSTR IN THE FORM OF LOW ST/SC CLOUDS WILL REMAIN TRAPPED
UNDER SUBSIDENCE INVERSION THRU THIS MORNING...AS HIGH PRES
BEGINS TO BUILD INTO THE AREA IN THE WAKE OF DEPARTING UPPER TROF.
WEAK LLVL UPSLOPE WILL KEEP IFR TO LOW MVFR CIGS AT BFD AND JST
THRU 16-18Z...WHILE DOWNSLOPE WNW FLOW SHOULD HELP PROMOTE GRADUAL
IMPROVEMENT/VFR CIGS EAST OF THE MTNS. FCST SOUNDINGS SUPPORT SOME
PATCHY -FZDZ AND ICING CONCERNS OVER THE HIER TERRAIN INVOF
BFD/JST THRU 13Z. LOW CIGS WILL BE SLOW TO DISSIPATE TDY ESP ACRS
THE WRN TAFS WITH WDSPRD VFR CONDS ANTICIPATED /ALONG WITH CLEARING/
BY THIS EVE AND TNT. SFC WNDS WILL GRADUALLY WEAKEN AND BACK TO
THE SOUTH BY THE END OF THE PD/12Z TUE.
OUTLOOK...
TUE-THUR...MAINLY VFR...MVFR CIGS PSBL N/W WED-THUR.
THUR NGT-FRI...BCMG MVFR/IFR WITH RAIN SHOWERS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...LA CORTE/GARTNER
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
535 AM EST MON JAN 7 2013
.SYNOPSIS...
HIGH PRESSURE WILL DOMINATE THE REGIONAL PATTERN THROUGH MID-
WEEK...BRINGING DRY AND TRANQUIL WEATHER CONDITIONS TO THE AREA.
A RELATIVELY MILD SOUTHWEST RETURN FLOW SHOULD ALLOW TEMPERATURES
TO MODERATE WELL-ABOVE SEASONAL CLIMATE NORMALS BY WEDNESDAY AND
THURSDAY. THE NEXT CHANCE FOR PRECIPITATION WILL COME BY THE END
OF THE WEEK...AS LOW PRESSURE MOVES INTO THE GREAT LAKES REGION.
&&
.NEAR TERM /UNTIL NOON TODAY/...
EXTENSIVE LOW-LEVEL MSTR/CLOUD COVER IN THE WAKE OF A NEBULOUS
SFC LOW MOVG AWAY FROM NRN NEW ENGLAND WILL PERSIST ACRS MUCH OF
WESTERN AND CENTRAL PA THIS MORNING...AS UPSLOPE WLY FLOW
CONTINUES TO PROVIDE SUFFICIENT /ALBEIT WEAK/ OROGRAPHIC LIFT OVER
THE ALLEGHENIES. REGIONAL RADAR MOSAIC ALSO INDICATES SOME LGT
PCPN ACRS THE WRN AND NRN MTNS...EITHER IN THE FORM OF -SN OR
PATCHY -FZDZ. THE RAP AND 4KM NAM FCST SOUNDINGS FAVOR -FZDZ
PROFILES THRU THE PRE DAWN HOURS AS MID-LVL MSTR IS STRIPPED AWAY.
THE CLOUD COVER AND STEADY 5-10KT WNW WIND WILL KEEP TEMPS IN
THE UPPER 20S TO MID 30S. LOW CLOUDS WILL LKLY BE SLOW TO ERODE
AFT SUNRISE ESP IN THE WRN MTNS AS LOW-LEVEL MSTR GETS TRAPPED
UNDER SFC RIDGE MOVG EWD FM THE OH VLY. HOWEVER ANTICIPATE SOME
BINOVC E OF THE MTNS.
&&
.SHORT TERM /NOON TODAY THROUGH 6 AM TUESDAY/...
LG SCALE SUBSIDENCE ASSOC WITH THE AFOREMENTIONED SFC HIGH AND
BACKING LLVL FLOW /TO THE SSW/ SHOULD AFFORD MORE PEAKS OF SUN AS
THE DAY WEARS ON. HIGHS SHOULD CLIMB A FEW DEGS ABOVE EARLY
JANUARY CLIMATE NORMALS...RANGING FROM THE LOW-MID 30S OVER THE
ALLEGHENIES TO THE LOW 40S OVER THE LWR SUSQ VLY. EXPECT MAINLY
CLR SKIES OVERNIGHT AS THE RIDGE MOVES OVER THE AREA...WITH LOWS
VARYING FROM THE UPPER TEENS TO MID 20S.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
MODERATELY AMPLIFIED SPLIT FLOW PATTERN WILL PREVAIL THROUGH THE
UPCOMING WORKWEEK...WITH THE NORTHERN STREAM TAPPING MAINLY PACIFIC
AIR THROUGH THE PERIOD.
EARLY IN THE PERIOD...A RIDGE OF SFC HIGH PRESSURE WILL EXTEND FROM
THE WESTERN ATLANTIC TO THE VIRGINIAS...WITH A DEVELOPING SWRLY FLOW
AND ABUNDANT SUNSHINE TEAMING UP TO BOOST TEMPS SOME 7-10F ABOVE
NORMAL. POPS WILL BE ZERO FOR THE DAY TUESDAY.
FOR TUESDAY NIGHT AND WEDNESDAY...A WELL DEFINED AND FAST MOVING NRN
STREAM SHORTWAVE WILL TRACK FROM THE UPPER GLAKES...TO THE NERN U.S.
BY 00Z THUR. BROAD...UPPER DIFFLUENT FLOW BETWEEN TWO DISTINCT 300
MB JET MAXES IN EXCESS OF 100 KTS AND A BRIEF PUSH OF NEAR 0.50 INCH
PWATS WILL BRING JUST A FEW TO SVRL HOUR PERIOD LAYERED BROKEN CLOUD
COVER AND PERHAPS A FEW SPRINKLES...OR BRIEF LIGHT RAIN/SNOW SHOWERS
ACROSS THE WRN MTNS DURING THE EARLY TO MID MORNING HOURS WEDNESDAY
/INVOF OF A MOISTURE CHALLENGED WARM FRONT/.
FAIRLY STRONG SUBSIDENCE IN THE WARM SECTOR WILL FOLLOW FOR THE
MIDDAY AND AFTERNOON HOURS WEDNESDAY...BENEATH THE THERMALLY
INDIRECT RIGHT EXIT REGION OF A 150 KT UPPER JET STREAK CROSSING NEW
YORK STATE. PARTLY TO MOSTLY SUNNY SKIES FOR WEDNESDAY AFTERNOON
WILL BOOST TEMPS FURTHER /BY ABOUT 5 DEG F HIGHER THAN TUESDAY/.
HIGHS WED AFTN WILL VARY FROM THE LOWER 40S ACROSS THE NW MTNS TO
THE LOWER 50S IN SOME OF THE SOUTHERN VALLEYS. THESE READINGS WILL
BE ROUGHLY 10-15F ABOVE NORMAL...WITH THE GREATER DEPARTURES
OCCURRING ACROSS THE MTNS.
WESTERLY WINDS WILL QUICKLY INCREASE WEDNESDAY MORNING...AND WILL
LIKELY GUST BETWEEN 30-35 MPH AT TIMES IN THE AFTERNOON /ESPECIALLY
ACROSS THE HIGHER TERRAIN OF THE NORTH AND WEST/.
A BRIEF SHOT OF SLIGHTLY COOLER AIR FOLLOWS THE EXIT OF THIS NRN
STREAM WAVE WEDNESDAY NIGHT. AS WINDS DIMINISH QUICKLY IN THE
EVENING AND SKIES STAY MAINLY CLEAR...TEMPS WILL FALL TO AROUND 20F
ACROSS THE NRN MTNS /WHERE THE DEEPEST SNOW COVER WILL REMAIN/ TO
NEAR 30F IN THE SOUTHEAST.
SFC HIGH WILL BE CENTERED ACROSS WRN PENN TO START THE DAY
THURSDAY...AND WILL SLIDE EAST ACROSS THE COMMONWEALTH DURING THE
AFTERNOON. A SLOW MOVING...CLOSED UPPER LOW IMPACTING FAR WEST TEXAS
EARLY IN THE WEEK WILL LIFT NE WED AND THURSDAY...AS AN OPENING WAVE
IN THE AMPLIFYING SWRLY FLOW ACROSS THE MIDWEST AND GLAKES REGION.
INCREASING DEEP-LAYER WARM ADVECTION AHEAD OF THIS SYSTEM LATE
THURSDAY INTO EARLY FRIDAY WILL BRING THICKENING CLOUDS AND HIGH CHC
TO LOW LIKELY POPS FOR RAIN SHOWERS. THE VERY DRY LLVLS COULD COOL
TO JUST BELOW FREEZING AS THE PRECIP SPREADS NE THURSDAY
NIGHT...POSSIBLY LEADING TO SOME SPOTTY LIGHT MIXED PRECIP...MAINLY
TO THE NORTH AND EAST OF KIPT WHERE A FEW HOURS OF CLEARING ARE
POSSIBLE DURING THE EVENING HOURS.
IN THE WAKE OF THIS MINOR PRECIP EVENT AND SOME ADDITIONAL
SNOWMELT/RUNOFF...TEMPS WILL SLOWLY RISE TO EVEN GREATER DEPARTURES
FROM NORMAL AS A VERY ANOMALOUS UPPER RIDGE OF PLUS 2-3 ST
DEVIATIONS AMPLIFIES ACROSS THE GLAKES...EAST THROUGH THE NE U.S.
AND SERN CANADA.
HIGH TEMPS BY SATURDAY COULD BE EASILY 15-20F ABOVE NORMAL ACROSS
THE CENTRAL AND SRN PORTIONS OF THE CWA...WITH MAXES RANGING FROM
THE MID 40S IN THE NORTH...TO LOWER AND MID 50S THROUGHOUT SOUTHERN
PENN.
INCREASING CHCS FOR RAIN WILL DEVELOP FOR THE SECOND HALF OF THE
WEEKEND AS A SLOW MOVING COLD FRONT PRESSES EAST TWD THE REGION AND
ONE OR MORE WAVES OF SFC LOW PRESSURE RIDE NEWD ALONG IT.
A BIG PATTERN CHANGE IS LIKELY THE FOLLOWING WEEK AS SIGNIFICANT
RIDGING DEVELOPS ACROSS THE EASTERN PACIFIC AND ALLOWS A LARGE AREA
OF ARCTIC AIR TO SURGE SE INTO THE NRN ROCKIES AND UPPER MID VALLEY
MONDAY AND TUESDAY...WITH COOLER AIR OOZING INTO THE MIDDLE ATLANTIC
AND LOWER GLAKES REGION.
THE NEXT POTENTIAL WINTRY /OR SIGNIFICANT RAIN EVENT/ WILL LIKELY BE
NEXT TUESDAY INTO WEDNESDAY AS THE NRN AND SRN STREAM PHASES INTO A
HIGH AMPLITUDE TROUGH FROM THE UPPER GLAKES...SWD TO THE LOWER MISS
VALLEY.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
07/09Z UPDATE...VRY MINOR CHANGES TO 07/06Z TAFS AS FCST IS
GENERALLY IN CATG. XPCT IFR TO CONT AT BFD/JST THRU 15Z...WITH
MVFR CIGS AT UNV/AOO AND VFR CIGS AT THE ERN AIRFIELDS IN ZNY
SECTOR.
PREVIOUS DISCUSSION 07/06Z...
SHALLOW MSTR IN THE FORM OF LOW ST/SC CLOUDS WILL REMAIN TRAPPED
UNDER INC SUBSIDENCE INVERSION THIS MORNING...AS HIGH PRES BEGINS
TO BUILD INTO THE AREA IN THE WAKE OF DEPARTING UPPER TROF. WEAK
LLVL UPSLOPE WILL KEEP LOW MVFR/IFR CIGS AT BFD AND JST THE
LONGEST...WHILE DOWNSLOPE SHOULD HELP PROMOTE GRADUAL IMPROVEMENT
TO VFR CIGS EAST OF THE MTNS. SOME SCT LGT SHSN OR FLURRIES ARE
POSSIBLE ACRS THE WRN/CNTRL TAFS...BUT ANY VIS REDUCTIONS SHOULD
REMAIN AOA 5SM. FCST SOUNDINGS SUGGEST SOME PATCHY -FZDZ IS PSBL
OVER THE HIER TERRAIN AND BFD/JST HAVE BOTH REPORTED UP IN THE
LAST FEW HOURS...BUT WILL NOT MENTION IN TAF DUE TO ISOLD CVRG AND
LOW PROB. LOW CIGS WILL LKLY BE SLOW TO DISSIPATE TDY ESP ACRS THE
WRN TAFS...WITH WDSPRD VFR CONDS ANTICIPATED BY THIS EVE/TNT. SFC
WNDS WILL GRADUALLY WEAKEN AND BACK TO THE SOUTH BY THE END OF THE
PD.
OUTLOOK...
TUE-THUR...MAINLY VFR...MVFR CIGS PSBL N/W WED-THUR.
THUR NGT-FRI...BCMG MVFR/IFR WITH RAIN SHOWERS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...LA CORTE/GARTNER
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
445 AM EST MON JAN 7 2013
.SYNOPSIS...
HIGH PRESSURE WILL DOMINATE THE REGIONAL PATTERN THROUGH MID-
WEEK...BRINGING DRY AND TRANQUIL WEATHER CONDITIONS TO THE AREA.
A RELATIVELY MILD SOUTHWEST RETURN FLOW SHOULD ALLOW TEMPERATURES
TO MODERATE WELL-ABOVE SEASONAL CLIMATE NORMALS BY WEDNESDAY AND
THURSDAY. THE NEXT CHANCE FOR PRECIPITATION WILL COME BY THE END
OF THE WEEK...AS LOW PRESSURE MOVES INTO THE GREAT LAKES REGION.
&&
.NEAR TERM /UNTIL NOON TODAY/...
EXTENSIVE LOW-LEVEL MSTR/CLOUD COVER IN THE WAKE OF A NEBULOUS
SFC LOW MOVG AWAY FROM NRN NEW ENGLAND WILL PERSIST ACRS MUCH OF
WESTERN AND CENTRAL PA THIS MORNING...AS UPSLOPE WLY FLOW
CONTINUES TO PROVIDE SUFFICIENT /ALBEIT WEAK/ OROGRAPHIC LIFT OVER
THE ALLEGHENIES. REGIONAL RADAR MOSAIC ALSO INDICATES SOME LGT
PCPN ACRS THE WRN AND NRN MTNS...EITHER IN THE FORM OF -SN OR
PATCHY -FZDZ. THE RAP AND 4KM NAM FCST SOUNDINGS FAVOR -FZDZ
PROFILES THRU THE PRE DAWN HOURS AS MID-LVL MSTR IS STRIPPED AWAY.
THE CLOUD COVER AND STEADY 5-10KT WNW WIND WILL KEEP TEMPS IN
THE UPPER 20S TO MID 30S. LOW CLOUDS WILL LKLY BE SLOW TO ERODE
AFT SUNRISE ESP IN THE WRN MTNS AS LOW-LEVEL MSTR GETS TRAPPED
UNDER SFC RIDGE MOVG EWD FM THE OH VLY. HOWEVER ANTICIPATE SOME
BINOVC E OF THE MTNS.
&&
.SHORT TERM /NOON TODAY THROUGH 6 AM TUESDAY/...
LG SCALE SUBSIDENCE ASSOC WITH THE AFOREMENTIONED SFC HIGH AND
BACKING LLVL FLOW /TO THE SSW/ SHOULD AFFORD MORE PEAKS OF SUN AS
THE DAY WEARS ON. HIGHS SHOULD CLIMB A FEW DEGS ABOVE EARLY
JANUARY CLIMATE NORMALS...RANGING FROM THE LOW-MID 30S OVER THE
ALLEGHENIES TO THE LOW 40S OVER THE LWR SUSQ VLY. EXPECT MAINLY
CLR SKIES OVERNIGHT AS THE RIDGE MOVES OVER THE AREA...WITH LOWS
VARYING FROM THE UPPER TEENS TO MID 20S.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
MODERATELY AMPLIFIED SPLIT FLOW PATTERN WILL PREVAIL THROUGH THE
UPCOMING WORKWEEK...WITH THE NORTHERN STREAM TAPPING MAINLY PACIFIC
AIR THROUGH THE PERIOD.
EARLY IN THE PERIOD...A RIDGE OF SFC HIGH PRESSURE WILL EXTEND FROM
THE WESTERN ATLANTIC TO THE VIRGINIAS...WITH A DEVELOPING SWRLY FLOW
AND ABUNDANT SUNSHINE TEAMING UP TO BOOST TEMPS SOME 7-10F ABOVE
NORMAL. POPS WILL BE ZERO FOR THE DAY TUESDAY.
FOR TUESDAY NIGHT AND WEDNESDAY...A WELL DEFINED AND FAST MOVING NRN
STREAM SHORTWAVE WILL TRACK FROM THE UPPER GLAKES...TO THE NERN U.S.
BY 00Z THUR. BROAD...UPPER DIFFLUENT FLOW BETWEEN TWO DISTINCT 300
MB JET MAXES IN EXCESS OF 100 KTS AND A BRIEF PUSH OF NEAR 0.50 INCH
PWATS WILL BRING JUST A FEW TO SVRL HOUR PERIOD LAYERED BROKEN CLOUD
COVER AND PERHAPS A FEW SPRINKLES...OR BRIEF LIGHT RAIN/SNOW SHOWERS
ACROSS THE WRN MTNS DURING THE EARLY TO MID MORNING HOURS WEDNESDAY
/INVOF OF A MOISTURE CHALLENGED WARM FRONT/.
FAIRLY STRONG SUBSIDENCE IN THE WARM SECTOR WILL FOLLOW FOR THE
MIDDAY AND AFTERNOON HOURS WEDNESDAY...BENEATH THE THERMALLY
INDIRECT RIGHT EXIT REGION OF A 150 KT UPPER JET STREAK CROSSING NEW
YORK STATE. PARTLY TO MOSTLY SUNNY SKIES FOR WEDNESDAY AFTERNOON
WILL BOOST TEMPS FURTHER /BY ABOUT 5 DEG F HIGHER THAN TUESDAY/.
HIGHS WED AFTN WILL VARY FROM THE LOWER 40S ACROSS THE NW MTNS TO
THE LOWER 50S IN SOME OF THE SOUTHERN VALLEYS. THESE READINGS WILL
BE ROUGHLY 10-15F ABOVE NORMAL...WITH THE GREATER DEPARTURES
OCCURRING ACROSS THE MTNS.
WESTERLY WINDS WILL QUICKLY INCREASE WEDNESDAY MORNING...AND WILL
LIKELY GUST BETWEEN 30-35 MPH AT TIMES IN THE AFTERNOON /ESPECIALLY
ACROSS THE HIGHER TERRAIN OF THE NORTH AND WEST/.
A BRIEF SHOT OF SLIGHTLY COOLER AIR FOLLOWS THE EXIT OF THIS NRN
STREAM WAVE WEDNESDAY NIGHT. AS WINDS DIMINISH QUICKLY IN THE
EVENING AND SKIES STAY MAINLY CLEAR...TEMPS WILL FALL TO AROUND 20F
ACROSS THE NRN MTNS /WHERE THE DEEPEST SNOW COVER WILL REMAIN/ TO
NEAR 30F IN THE SOUTHEAST.
SFC HIGH WILL BE CENTERED ACROSS WRN PENN TO START THE DAY
THURSDAY...AND WILL SLIDE EAST ACROSS THE COMMONWEALTH DURING THE
AFTERNOON. A SLOW MOVING...CLOSED UPPER LOW IMPACTING FAR WEST TEXAS
EARLY IN THE WEEK WILL LIFT NE WED AND THURSDAY...AS AN OPENING WAVE
IN THE AMPLIFYING SWRLY FLOW ACROSS THE MIDWEST AND GLAKES REGION.
INCREASING DEEP-LAYER WARM ADVECTION AHEAD OF THIS SYSTEM LATE
THURSDAY INTO EARLY FRIDAY WILL BRING THICKENING CLOUDS AND HIGH CHC
TO LOW LIKELY POPS FOR RAIN SHOWERS. THE VERY DRY LLVLS COULD COOL
TO JUST BELOW FREEZING AS THE PRECIP SPREADS NE THURSDAY
NIGHT...POSSIBLY LEADING TO SOME SPOTTY LIGHT MIXED PRECIP...MAINLY
TO THE NORTH AND EAST OF KIPT WHERE A FEW HOURS OF CLEARING ARE
POSSIBLE DURING THE EVENING HOURS.
IN THE WAKE OF THIS MINOR PRECIP EVENT AND SOME ADDITIONAL
SNOWMELT/RUNOFF...TEMPS WILL SLOWLY RISE TO EVEN GREATER DEPARTURES
FROM NORMAL AS A VERY ANOMALOUS UPPER RIDGE OF PLUS 2-3 ST
DEVIATIONS AMPLIFIES ACROSS THE GLAKES...EAST THROUGH THE NE U.S.
AND SERN CANADA.
HIGH TEMPS BY SATURDAY COULD BE EASILY 15-20F ABOVE NORMAL ACROSS
THE CENTRAL AND SRN PORTIONS OF THE CWA...WITH MAXES RANGING FROM
THE MID 40S IN THE NORTH...TO LOWER AND MID 50S THROUGHOUT SOUTHERN
PENN.
INCREASING CHCS FOR RAIN WILL DEVELOP FOR THE SECOND HALF OF THE
WEEKEND AS A SLOW MOVING COLD FRONT PRESSES EAST TWD THE REGION AND
ONE OR MORE WAVES OF SFC LOW PRESSURE RIDE NEWD ALONG IT.
A BIG PATTERN CHANGE IS LIKELY THE FOLLOWING WEEK AS SIGNIFICANT
RIDGING DEVELOPS ACROSS THE EASTERN PACIFIC AND ALLOWS A LARGE AREA
OF ARCTIC AIR TO SURGE SE INTO THE NRN ROCKIES AND UPPER MID VALLEY
MONDAY AND TUESDAY...WITH COOLER AIR OOZING INTO THE MIDDLE ATLANTIC
AND LOWER GLAKES REGION.
THE NEXT POTENTIAL WINTRY /OR SIGNIFICANT RAIN EVENT/ WILL LIKELY BE
NEXT TUESDAY INTO WEDNESDAY AS THE NRN AND SRN STREAM PHASES INTO A
HIGH AMPLITUDE TROUGH FROM THE UPPER GLAKES...SWD TO THE LOWER MISS
VALLEY.
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
SHALLOW MSTR IN THE FORM OF LOW ST/SC CLOUDS WILL REMAIN TRAPPED
UNDER INC SUBSIDENCE INVERSION THIS MORNING...AS HIGH PRES BEGINS
TO BUILD INTO THE AREA IN THE WAKE OF DEPARTING UPPER TROF. WEAK
LLVL UPSLOPE WILL KEEP LOW MVFR/IFR CIGS AT BFD AND JST THE
LONGEST...WHILE DOWNSLOPE SHOULD HELP PROMOTE GRADUAL IMPROVEMENT
TO VFR CIGS EAST OF THE MTNS. SOME SCT LGT SHSN OR FLURRIES ARE
POSSIBLE ACRS THE WRN/CNTRL TAFS...BUT ANY VIS REDUCTIONS SHOULD
REMAIN AOA 5SM. FCST SOUNDINGS SUGGEST SOME PATCHY -FZDZ IS PSBL
OVER THE HIER TERRAIN AND BFD/JST HAVE BOTH REPORTED UP IN THE
LAST FEW HOURS...BUT WILL NOT MENTION IN TAF DUE TO ISOLD CVRG AND
LOW PROB. LOW CIGS WILL LKLY BE SLOW TO DISSIPATE TDY ESP ACRS THE
WRN TAFS...WITH WDSPRD VFR CONDS ANTICIPATED BY THIS EVE/TNT. SFC
WNDS WILL GRADUALLY WEAKEN AND BACK TO THE SOUTH BY THE END OF THE
PD.
OUTLOOK...
TUE-WED...MAINLY VFR...MVFR PSBL ON WED.
THU...VFR...DETERIORATING CONDITIONS PSBL LATER THURSDAY NIGHT.
FRI...MVFR/IFR WITH RAIN SHOWERS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...LA CORTE/GARTNER
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
321 AM EST MON JAN 7 2013
.SYNOPSIS...
HIGH PRESSURE WILL DOMINATE THE REGIONAL PATTERN THROUGH MID-
WEEK...BRINGING DRY AND TRANQUIL WEATHER CONDITIONS TO THE AREA.
A RELATIVELY MILD SOUTHWEST RETURN FLOW SHOULD ALLOW TEMPERATURES
TO MODERATE WELL-ABOVE SEASONAL CLIMATE NORMALS BY WEDNESDAY AND
THURSDAY. THE NEXT CHANCE FOR PRECIPITATION WILL COME BY THE END
OF THE WEEK...AS LOW PRESSURE MOVES INTO THE GREAT LAKES REGION.
&&
.NEAR TERM /UNTIL NOON TODAY/...
EXTENSIVE LOW-LEVEL MSTR/CLOUD COVER IN THE WAKE OF A NEBULOUS
SFC LOW MOVG AWAY FROM NRN NEW ENGLAND WILL PERSIST ACRS MUCH OF
WESTERN AND CENTRAL PA THIS MORNING...AS UPSLOPE WLY FLOW
CONTINUES TO PROVIDE SUFFICIENT /ALBEIT WEAK/ OROGRAPHIC LIFT OVER
THE ALLEGHENIES. REGIONAL RADAR MOSAIC ALSO INDICATES SOME LGT
PCPN ACRS THE WRN AND NRN MTNS...EITHER IN THE FORM OF -SN OR
PATCHY -FZDZ. THE RAP AND 4KM NAM FCST SOUNDINGS FAVOR -FZDZ
PROFILES THRU THE PRE DAWN HOURS AS MID-LVL MSTR IS STRIPPED AWAY.
THE CLOUD COVER AND STEADY 5-10KT WNW WIND WILL KEEP TEMPS IN
THE UPPER 20S TO MID 30S. LOW CLOUDS WILL LKLY BE SLOW TO ERODE
AFT SUNRISE ESP IN THE WRN MTNS AS LOW-LEVEL MSTR GETS TRAPPED
UNDER SFC RIDGE MOVG EWD FM THE OH VLY. HOWEVER ANTICIPATE SOME
BINOVC E OF THE MTNS.
&&
.SHORT TERM /NOON TODAY THROUGH 6 AM TUESDAY/...
LG SCALE SUBSIDENCE ASSOC WITH THE AFOREMENTIONED SFC HIGH AND
BACKING LLVL FLOW /TO THE SSW/ SHOULD AFFORD MORE PEAKS OF SUN AS
THE DAY WEARS ON. HIGHS SHOULD CLIMB A FEW DEGS ABOVE EARLY
JANUARY CLIMATE NORMALS...RANGING FROM THE LOW-MID 30S OVER THE
ALLEGHENIES TO THE LOW 40S OVER THE LWR SUSQ VLY. EXPECT MAINLY
CLR SKIES OVERNIGHT AS THE RIDGE MOVES OVER THE AREA...WITH LOWS
VARYING FROM THE UPPER TEENS TO MID 20S.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
MODERATELY AMPLIFIED SPLIT FLOW PATTERN WILL BRING SEVERAL
NORTHERN STREAM WAVES ACROSS THE NORTHEAST THIS PERIOD WHILE
A CLOSED UPR LOW IN THE SRN STREAM NOW OVER SRN CALIFORNIA
MEANDERS ACROSS MEXICO THEN ACROSS THE SOUTHERN U.S. BEFORE
POSSIBLY REACHING THE EASTERN PART OF THE COUNTRY NEXT WEEKEND.
NORTHERN STORM TRACK LOOKS TO GO MAINLY NORTH OF PA...KEEPING
THE PERIOD GENERALLY DRY WITH SFC HIGH PRESSURE DOMINATING PA.
IT SHOULD BECOME PROGRESSIVELY WARMER AS LOW LEVEL FLOW REMAINS
SWRLY.
ONE FROPA WED WILL PROVIDE A SLIGHT SLIGHT CHANCE OF SHOWERS MID
WEEK.
MOISTENING LOW LEVELS ON THE SWRLY FLOW COMBINED WITH THE ARRIVAL
OF THE SRN STREAM FORCING WILL BRING INCREASING CHANCES FOR
SHOWERS...MAINLY RAIN SHOWERS...LATER THURSDAY AND CONTINUING
THROUGH NEXT WEEKEND.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
SHALLOW MSTR IN THE FORM OF LOW ST/SC CLOUDS WILL REMAIN TRAPPED
UNDER INC SUBSIDENCE INVERSION THIS MORNING...AS HIGH PRES BEGINS
TO BUILD INTO THE AREA IN THE WAKE OF DEPARTING UPPER TROF. WEAK
LLVL UPSLOPE WILL KEEP LOW MVFR/IFR CIGS AT BFD AND JST THE
LONGEST...WHILE DOWNSLOPE SHOULD HELP PROMOTE GRADUAL IMPROVEMENT
TO VFR CIGS EAST OF THE MTNS. SOME SCT LGT SHSN OR FLURRIES ARE
POSSIBLE ACRS THE WRN/CNTRL TAFS...BUT ANY VIS REDUCTIONS SHOULD
REMAIN AOA 5SM. FCST SOUNDINGS SUGGEST SOME PATCHY -FZDZ IS PSBL
OVER THE HIER TERRAIN AND BFD/JST HAVE BOTH REPORTED UP IN THE
LAST FEW HOURS...BUT WILL NOT MENTION IN TAF DUE TO ISOLD CVRG AND
LOW PROB. LOW CIGS WILL LKLY BE SLOW TO DISSIPATE TDY ESP ACRS THE
WRN TAFS...WITH WDSPRD VFR CONDS ANTICIPATED BY THIS EVE/TNT. SFC
WNDS WILL GRADUALLY WEAKEN AND BACK TO THE SOUTH BY THE END OF THE
PD.
OUTLOOK...
TUE-WED...MAINLY VFR...MVFR PSBL ON WED.
THU...VFR...DETERIORATING CONDITIONS PSBL LATER THURSDAY NIGHT.
FRI...MVFR/IFR WITH RAIN SHOWERS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...LA CORTE/GARTNER
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
340 PM CST MON JAN 7 2013
.DISCUSSION.../ISSUED AT 340 PM/
MULTIPLE PLAYERS IN TODAY/S FORECAST FOR TONIGHT INTO TOMORROW.
CURRENTLY...MOSTLY CLEAR SKIES ACROSS THE AREA WITH A FEW HIGH
CLOUDS ACROSS CENTRAL SOUTH DAKOTA. THE SUNSHINE HAS PROMOTED SNOW
MELT...BUT WITH WEAK WINDS AND STRONG INVERSION...MOISTURE REMAINS
IN THE NEAR SURFACE LAYER. COULD SEE FOG DEVELOP OVERNIGHT
TONIGHT...BUT TRICKY TO PIN POINT WHERE EXACTLY. HRRR CONTINUES TO
SUGGEST THAT PATCHY FOG WILL BE POSSIBLY ACROSS THE NORTH...WHILE
NAM FOCUSES ON THE SOUTH AND EAST. HAVE SIDED CLOSER TO NAM...BUT
WITH WEAK WINDS...COULD GET RADIATIONAL FOG NEARLY ANYWHERE CLEAR
SKIES REMAIN FOR A FEW HOURS. AS MENTIONED IN THE MORNING
DISCUSSION...AMPLIFYING WAVE MOVING ACROSS THE AREA LATE TONIGHT
WITH UPPER LEVEL DIV Q INCREASING AFTER 06Z MAINLY ACROSS THE
NORTHERN HALF OF THE FORECAST AREA. WITH FAIRLY DRY AIR THROUGH THE
MID LEVELS OF THE ATMOSPHERE...AM NOT EXPECTING ANY PRECIPITATION
AND DROPPED MENTION OF SPRINKLES/FLURRIES FROM THE FORECAST. IF FOG
DEVELOPS IN THE SOUTHEAST...WILL NEED TO KEEP AN EYE ON DRIZZLE
POTENTIAL WITH WEAK LIFT IN THE LOW LEVELS OF THE ATMOSPHERE.
COLD FRONT IS POISED TO MOVE THROUGH THE AREA ON TUESDAY. SOUTHERLY
WINDS WILL BECOME WEST AND SOMEWHAT GUSTY BEHIND THE FRONT WITH
20-30 KNOTS OF FLOW AT 925 HPA. NOT MUCH IN THE WAY OF COLD AIR
ADVECTION BEHIND THE FRONT...AND WITH ONLY MEAGER PRESSURE RISES AND
STRONG INVERSION REMAINING ALOFT...WILL STRUGGLE TO GET A LOT OF THE
MOMENTUM DOWN THE SURFACE. STRONGEST WINDS WILL LIKELY BE ACROSS
THE NORTHERN EDGE OF THE FORECAST AREA WITH STRONGEST GRADIENT WINDS
THERE...BUT STILL LOOK TO REMAIN BELOW ADVISORY CRITERIA.
UPPER LEVEL TROUGH IS EXPECTED TO DIG ACROSS THE DESERT SOUTHWEST
MID WEEK...WHICH PUSHES THE RIDGE AXIS OVER THE FORECAST AREA ON
WEDNESDAY. EXPECT ANOTHER RELATIVELY MILD DAY WITH MOSTLY SUNNY
SKIES AND ABOVE NORMAL TEMPERATURES. EXPECT HIGHS TO REACH JUST
ABOVE FREEZING IN SOUTHWEST MINNESOTA AND ADJACENT AREAS...NUDGING
INTO THE UPPER 30S IN NORTHWEST IOWA. THE WARMEST READINGS WILL BE
FOUND IN SOUTH CENTRAL SOUTH DAKOTA WITH THE MID OR UPPER 40S IN
AREAS WHERE MUCH OF THE SNOWPACK HAS MELTED.
FOR THURSDAY...A CUT OFF LOW IS EXPECTED TO FORM IN THE SOUTHWEST
PLAINS AND TRACK NORTHEAST INTO THE NORTHERN GREAT LAKES EARLY
SATURDAY. SOME MODEL DIFFERENCES STILL EXIST...WITH THE ECMWF AND
GEM STILL FOLLOWING A SLOWER AND SLIGHTLY MORE SOUTHERLY TRACK. ALL
MODELS DO CLIP OUR SOUTHEASTERN COUNTIES AS THE SURFACE LOW TRACKS
INTO IOWA THURSDAY EVENING. TEMPERATURES WILL BE PARTICULARLY TRICKY
WITH READINGS EXPECTED TO RISE UP ABOVE FREEZING BY THE AFTERNOON.
WITH VERY WARM LOW LEVELS...EXPECT PRECIPITATION TO BE ENTIRELY
LIQUID FOR THIS SYSTEM...BUT WITH SURFACE READINGS POTENTIALLY BELOW
FREEZING IN THE MORNING AND AGAIN THURSDAY NIGHT...FREEZING RAIN
WILL ALSO BE POSSIBLE. BUT GIVEN THAT THESE TEMPERATURES WILL ONLY
BE A DEGREE OR TWO BELOW FREEZING...ICE ACCUMULATION DOES NOT LOOK
TO BE SIGNIFICANT. BUT WILL STILL CONTINUE TO MONITOR FOR ANY
CHANGES IN THIS OUTLOOK.
TEMPERATURES ON FRIDAY WILL LIKELY BE SOMEWHAT STEADY OR BEGIN TO
FALL IN THE AFTERNOON AS COOLER TEMPERATURES BEGIN TO FILTER INTO
THE AREA BEHIND THIS SYSTEM. THE BROAD POSITIVELY TILTED TROUGH
DIGGING ACROSS THE SOUTHWEST PUSHES INTO THE WESTERN PLAINS FRIDAY
EVENING...BRINGING THE NEXT POTENTIAL FOR WET WEATHER TO REGION
FRIDAY NIGHT AND SATURDAY. AGAIN...THE ECMWF IS A BIT SLOWER AND
SHOWS MORE OF A CLOSED UPPER LEVEL FEATURE. A SLIGHT CHANCE FOR SOME
LIGHT SNOW OR FLURRIES WILL BE POSSIBLE AHEAD OF THE MAIN WAVE ON
FRIDAY. THE DETAILS ARE STILL QUITE UNCERTAIN AT THIS POINT...BUT
THE GFS APPEARS TO TAKE THE BEST DYNAMICS WEST AND NORTH OF THE
FORECAST AREA...WHILE THE ECMWF HAS A BIT MORE ORGANIZATION WITH A
DECENT BAND OF MID LEVEL FRONTOGENESIS MOVING THROUGH THE FORECAST
AREA. WILL KEEP MENTION OF POPS AS A HIGH CHANCE FOR SOME LIGHT
SNOWFALL FRIDAY NIGHT AND SATURDAY. PRELIMINARY AMOUNTS LOOK LIKE A
FEW INCHES WOULD BE POSSIBLE ACROSS THE CWA.
THE LOW EXITS THE AREA SATURDAY NIGHT WITH A STRONGER SHOT OF COLD
AIR ADVECTION ARRIVING IN ITS WAKE. TEMPERATURES WILL BE MUCH COOLER
FOR THE START OF NEXT WEEK WITH HIGHS MAINLY IN THE TEENS AND LOWS
AROUND ZERO.
&&
.AVIATION.../FOR THE 18Z TAF ISSUANCE/
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. WEST TO SOUTHWEST
FLOW WILL REMAIN LIGHT THROUGHOUT THE DAY TODAY...AND GRADUALLY
TRANSITION TO SOUTHERLY ON TUESDAY. THERE IS THE POTENTIAL FOR SOME
FOG TO DEVELOP THROUGH THE OVERNIGHT HOURS TONIGHT...AND HAVE ADDED
MENTION TO TAFS EAST OF JAMES RIVER INCLUDING KFSD AND KSUX
TERMINALS. FOG COULD BE LOCALLY DENSE WITH WEAK WINDS.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
242 AM EST Wed Jan 9 2013
.NEAR TERM [Through Today]...
03 UTC surface analysis shows a frontal boundary right along the
Northern Gulf Coast. This boundary was well defined, separating a
moist tropical airmass over the Central Gulf from a modified
continental one that has been in place across the Southeast. This
frontal boundary will lift northward today as a strong upper level
system moves through Central Texas. The best forcing for ascent is
expected to remain well off to the west of our region. As a
result, only a slight chance of showers are expected today as the
warm front lifts northward.
This front will also signal the beginning of a warm and humid
pattern that will last into much of next week. Even with all the
cloudiness in place this morning, expect enough breaks in the
cloud cover to support temperatures in the low to mid 70s. Areas
in the Southeast Florida Big Bend could also get into the upper
70s should more breaks develop in the overcast.
&&
.SHORT TERM [Tonight Through Friday]...
With the warm front lifting northward through the area by tonight,
the region will be in an increasingly more humid airmass, which
will likely support the formation of fog/stratus after midnight.
Temperatures will also be noticeably warmer with lows around 60
degrees.
Starting Thursday the storm system across Central Texas will
begin to move north northeast around a building mid level ridge
centered over the Florida Peninsula. As this system moves into the
Great Lakes, a weak cold front will move eastward across the
Central Gulf States. The strengthening ridge will slow the
eastward progress of this system as the main upper level energy
continues to move quickly northward. As a result, only low end
rain chances are expected Thursday night into Friday as this front
eventually dissipates across the region.
As was much the case in the near term period, the short term
period will have unseasonably warm temperatures with highs in the
low to mid 70s in the western areas (due to more cloud cover) and
in the upper 70s to near 80 in the east. Overnight lows will be
muggy by January standards, generally in the upper 50s to lower 60s.
&&
.LONG TERM [Friday Night through Tuesday]...
There is good agreement between the GFS and ECMWF that deep layer
ridging will be the dominant synoptic feature over the Southeast.
This correlates to a continuation of above-average temperatures (at
least 10 to 15 degrees warmer than climatology) away from the
beaches (where SSTs remain in the upper 50s to lower 60s). The PoP
will be in the 10 to 30% range- highest along and left of a line
from Albany to Panama City as that region will be closer to the Q-G
forcing and deep layer moisture associated with a persistent
quasi-stationary frontal system.
&&
.AVIATION [through 06z Thursday]...
As of 07 UTC there was no fog at the terminals and cigs were low-end
MVFR to IFR. Our local WRF and the latest HRRR fog/cig NWP output
seem to be verifying best so far, and suggest that this will mainly
be a low cig event (except at KVLD where a period of 1/2SM Vis is
likely by dawn). Elsewhere, widespread LIFR-IFR cigs will likely
remain until late morning or early afternoon. MVFR cigs are expected
this afternoon, followed by a return to LIFR-IFR cigs by evening.
Fog may develop sooner and be more widespread Wednesday night.
&&
.MARINE...
The pressure gradient will remain tight across the marine area as
a low pressure area lifts northward across Texas. Cautionary level
winds will continue possibly into Thursday before relaxing. Lighter
onshore flow is expected by the weekend as high pressure builds
just off the Florida Peninsula.
&&
.FIRE WEATHER...
Relative humidity levels will remain too moist for red flag
conditions for at least the remainder of this week.
&&
.HYDROLOGY...
No appreciable rainfall amounts are expected through the next few
days.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 75 61 77 59 74 / 10 10 10 20 20
Panama City 71 64 74 63 73 / 20 10 10 40 20
Dothan 71 61 75 62 75 / 20 10 10 30 20
Albany 72 60 75 62 75 / 10 10 10 20 20
Valdosta 76 61 78 60 78 / 10 10 10 10 20
Cross City 79 59 79 58 76 / 10 10 10 10 20
Apalachicola 69 64 70 63 70 / 10 10 10 30 20
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
GM...None.
&&
$$
NEAR TERM...Godsey
SHORT TERM...Godsey
LONG TERM...Fournier
AVIATION...Fournier
MARINE...Godsey
FIRE WEATHER...Fournier
HYDROLOGY...Godsey
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1114 PM CST TUE JAN 8 2013
.UPDATE...
UPDATED FOR AVIATION DISCUSSION BELOW.
&&
.DISCUSSION...
/ISSUED AT 310 PM CST TUE JAN 08 2013/
SCHEDULED SHORT WAVE TROUGH MOVING ACROSS EASTERN DAKOTAS THIS
AFTERNOON. THIS GENERATED SOME LIGHT SNOW SHOWERS AND SPRINKLES AS
IT MOVED INTO NORTHWEST MINNESOTA. THIS FEATURE IS PROGGED TO MOVE
EAST DURING THE EVENING AND SHOULD TAKE THE CHANCE OF LIGHT SNOW
WITH IT. WILL CONTINUE SMALL CHANCE POPS OVER THE NORTHEAST
QUADRANT OF THE CWA THIS EVENING. SOME INDICATIONS OF ANOTHER WEAK
WAVE ROTATING AROUND THE TROUGH INTO WESTERN MN THIS EVENING...AND
SPREADING BAND OF MID CLOUDS AND POSSIBLE SNOW SHOWERS ALONG THE
SECONDARY FRONT AS IT MOVES THROUGH EASTERN MN AROUND 08Z. WILL
HAVE TO MONITOR THIS EVENING AND SEE IF THIS WILL BE STRONG ENOUGH
TO GENERATE A FEW SNOW SHOWERS. WINDS ARE EXPECTED TO INCREASE
BEHIND FRONT AND BECOME A BIT GUSTY OVERNIGHT INTO EARLY
WEDNESDAY...MAINLY WEST UNTIL RIDGE BUILDS INTO THE AREA ONCE
AGAIN AND CLEARS THE SKY.
WEDNESDAY NIGHT AND INTO THURSDAY APPEARS DRY. MODELS HAVE TRENDED
SLOWER WITH SOUTHWEST CUTOFF LOW PRESSURE SYSTEM. MODELS WILL
CONTINUE TO HAVE PROBLEMS WITH TIMING OF EJECTION OF THIS LOW
UNTIL THE "KICKER TROUGH" MOVES SHORE ON OVER THE WESTERN CONUS.
WILL FOLLOW A GEM/ECMWF MOVEMENT OF THE SYSTEM WHICH WILL KEEP THE
AREA DRY THROUGH 18Z THU. WILL SPREAD LIKELY POPS INTO SOUTHERN CWA
DURING THE AFTERNOON. MAY NOT QUITE MAKE IT OVER THE NORTHERN CWA
BY 00Z FRI. THERMAL STRUCTURE OF THE ATMOSPHERE DOES FAVOR
RAIN...BUT THE LEADING EDGE OR FIRST HOUR OR SO OF THE INITIAL
SURGE OF RAIN MAY BE LIGHT FREEZING RAIN. WILL KEEP IT LIQUID
DURING THE DAY THURSDAY CONSIDERING TIMING OF THE PRECIPITATION
MOVING IN DURING THE WARMER PORTION OF THE DAY. SURFACE
TEMPERATURES EXPECTED TO WARM THROUGH THE MID AND UPPER 30S
THURSDAY AFTERNOON.
INTO THURSDAY NIGHT AND FRIDAY...THE BAROCLINIC ZONE SHIFTS SLOWLY
EAST...MAINLY ON FRIDAY. THIS SHOULD LEAVE MOST IF NOT ALL OF THE
CWA IN THE WARM SECTOR AHEAD OF COLD FRONT THURSDAY NIGHT.
TEMPERATURES SHOULD REMAIN WARM ENOUGH FOR JUST RAIN OVER THE
EASTERN TWO THIRDS OF THE AREA. FOG AND DRIZZLE MAY BE MORE OF AN
ISSUE. THE WEST WILL SEE THE POSSIBILITY OF LIGHT FREEZING RAIN.
SREF PLUMES/FREEZING RAIN PROBABILITIES ARE STILL RATHER HIGH
DURING THIS PERIOD...SO DONT WANT TO REMOVE THAT THREAT JUST YET.
AS THE OVERALL TRENDS BECOME CLEARER...WE MAY BE ABLE TO DO THAT
IN LATER FORECASTS.
THE GEM AND ND ECMWF ARE TRENDING MORE SURFACE LOW DEVELOPMENT TO
THE NORTHEAST AS THE TROUGH DEVELOPS AND LIFTS ENERGY RAPIDLY
ACROSS THE EASTERN DAKOTAS AND NORTHERN MINNESOTA FRIDAY NIGHT
INTO SATURDAY. THIS SPREADS AN AREA OF SNOW OVER NORTHERN
MINNESOTA...AND MAY AFFECT OUR NORTHERN CWA IN MN WITH A CHANGE TO
SOME ACCUMULATING SNOW. AGAIN...UNTIL THE WESTERN CONUS TROUGH
COMES ASHORE...OVERALL DEVELOPMENT AND MOVEMENT OF SYSTEMS STILL
IN DOUBT.
MUCH COOLER AIR/BELOW NORMAL FOLLOWS THIS SYSTEM AS IT MOVES ACROSS THE
NORTHERN CONUS. NORTHWEST FLOW ALOFT BECOMES ESTABLISHED AND
SHOULD HELP DRAW THE COLDER AIR IN FROM CANADA THROUGH AT LEAST
THROUGH THE END OF NEXT WEEK.
&&
.AVIATION.../06Z TAF ISSUANCE/
BATCH OF MVFR CEILINGS MOVING QUICKLY EAST AND SHOULD EXIT
KEAU/KRNH BY 08Z. NEXT LOBE OF MVFR CEILINGS IN ERN ND WHICH IS
MOVING ESE. LATEST RAP BRUSHES AXN/STC/RNH AND HAVE ADDED A TEMPO
GROUP FOR SOME BROKEN 2000-2500 FOOT CEILINGS. OTHERWISE SOME
GUSTY WNW WIND THROUGH MIDDAY UNTIL SURFACE RIDGE APPROACHES.
QUICK TRANSITION TO SOUTHERLY WINDS LATER WED AFTERNOON.
KMSP... BROKEN MID LEVEL CLOUDS THE REST OF THE NIGHT. LOBE OF STRATUS
IN ERN ND AROUND 2000 FEET AGL AND MOVING ESE. THIS SHOULD REMAIN
NORTH OF KMSP BUT HAVE ADDED SOME SCATTERED CLOUDS FOR THIS AROUND
11Z. ONLY A SMALL CHANCE OF THIS GOING BROKEN. WINDS GUSTING VOER
20 KNOTS SHOULD REMAIN WEST OR WNW BEFORE BECOMING SOUTH LATE WED
AFTERNOON.
/OUTLOOK FOR KMSP/
THU...VFR MORNING BECOMING MVFR CIGS/VSBYS LATE AFTERNOON.
THU NIGHT...IFR CIGS/VSBYS WITH LIFR AND -FZRA POSSIBLE. WINDS SE
AT 10-15KTS.
FRI...IFR WITH -RA. LIFR POSSIBLE. WINDS SSW AT 5-10KTS.
SAT...MVFR WITH -RASN POSSIBLE. COLD FRONT PASSAGE EARLY. WINDS
SSW AT 10KTS BECOMING NW AT 15G25KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
DWE/TDK
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
357 AM CST WED JAN 9 2013
.SHORT TERM...
ISSUED AT 349 AM CST WED JAN 9 2013
(TODAY)
WEAK COLD FRONT CONTINUES TO MOVE SOUTHEAST THROUGH FORECAST AREA
EARLY THIS MORNING WITH SOME LIGHT RAIN OUT AHEAD OF IT.
FRONT SHOULD WEAKEN/EXIT FORECAST AREA BY MID MORNING. AS FOR THE
RAIN...IT IS MAKING PROGRESS TO THE EAST...SO SHOULD COME TO AN END
BY BEGINNING OF FORECAST PERIOD. SO MAIN ISSUE TO DEAL WITH TODAY
WILL BE THE LINGERING CLOUD COVER AND HOW FAST IT WILL THIN OUT.
AREAS ALONG AND NORTH OF I-70 TO SEE THE MOST SUNSHINE TODAY...WHILE
AREAS TO THE SOUTH TO REMAIN MOSTLY CLOUDY THIS MORNING...BEFORE
SCATTERING OUT LATE THIS AFTERNOON. ALSO...WINDS TO VEER TO THE
WEST...THEN EVENTUALLY TO THE NORTH THIS AFTERNOON...BEHIND THIS
BOUNDARY.
HIGH TEMPS HARD TO PIN DOWN FOR TODAY...DEPENDING ON WHAT THE CLOUDS
ULTIMATELY DO TODAY AS WELL AS STRENGTH OF CAA WITH FRONTAL BOUNDARY.
FOR NOW WENT WITH UPPER 40S NORTHEAST TO THE MID 50S OVER CENTRAL
AND SOUTHERN MO.
BYRD
&&
.LONG TERM...
ISSUED AT 349 AM CST WED JAN 9 2013
(WEDNESDAY NIGHT - FRIDAY NIGHT)
MODELS CONTINUE TO COME INTO BETTER AGREEMENT ON A SLOWER EVOLUTION
OF UPPER LEVEL LOW TAKING IT FROM CNTRL TX THURSDAY MORNING TO AN
OPEN...BUT POTENT...WAVE ACROSS THE CWA THURSDAY NIGHT. THE LOW IS
IN THE PROCESS OF MAKING THE LEFT HAND TURN AND HEAD TOWARDS STHRN TX
DUE TO STRONG ENERGY ENTERING THE PACIFIC NW. ECMWF IS NOW ONE OF
THE FASTER MODELS WHILE THE GFS HAS TRANSITIONED TO A LITTLE DEEPER
AND CONSEQUENTLY SLOWER SOLUTION. HAVE BACKED OFF POPS CONSIDERABLY
THIS EVENING AND THEN TIGHTENED THE GRADIENT UP SOME AFTER MIDNIGHT
DUE TO THE SLOWER SOLUTIONS. SFC WARM FRONT TO LIFT THRU THE CWA
THURSDAY AND THEN PACIFIC COLD FRONT THURSDAY EVENING. THINKING ALL
PRECIP WILL BE EAST OF AREA BY 12Z FRIDAY. SHOULD BE A DECENT PUSH
OF WAA PRECIP TONIGHT INTO THURSDAY MORNING. COULD BE A BREAK IN THE
PRECIP BEFORE ANOTHER ROUND ASSOC WITH THE COLD FRONT THURSDAY LATE
AFTN/EVNG/OVERNIGHT. SYSTEM WILL BE TAPPING INTO SUBTROPICAL
MOISTURE. PWATS REMAIN CLIMATOLOGICALLY HIGH. DPS RISE INTO AT LEAST
THE LOWER 50S FOR THE SERN PORTION OF THE CWA THURSDAY NIGHT. 850
DPS OF +10C COVER A GOOD PORTION OF THE CWA THURSDAY AFTN/EVNG.
THUNDER IS STILL POSSIBLE EVEN THO PARAMETERS DON`T LOOK AS GOOD AS
THEY DID LAST NIGHT. WITH THE STRENGTH OF THE FORCING EXPECTED WITH
THIS EVENT...SHOULD BE SUFFICIENT FOR THUNDER. LOW/PRECIP PULL AWAY
FRIDAY LEAVING THE CWA IN SW FLOW AT THE SFC AND ALOFT. 925MB AND
850MB TEMPS OF +10C TO +14C FRIDAY AFTN WILL LEAD TO A VERY WARM DAY
WITH HIGHS IN THE 60S. CLIMATE SECTION OF AFD HAS HIGH/HIGH LOW
RECORDS FOR STL/COU/UIN FOR FRIDAY.
(SATURDAY - TUESDAY)
THIS MARKS THE BEGINNING OF A TRANSITION PERIOD. SATURDAY WILL BE THE
LAST WARM DAY FOR A WHILE. STRONG ARCTIC COLD FRONT PUSHES THRU THE
CWA DURING THE DAY. HIGHS...ESP ACROSS THE NORTH WILL BE IN THE
MORNING...WITH FALLING TEMPS BEHIND THE FRONT. THE FRONT INITIALLY PASSES
THRU DRY...BUT GETS HUNG UP JUST TO THE SE OF THE CWA AS WAVE OF LOW
PRESSURE RIDES NE ALONG THE FRONT SUNDAY NIGHT AND MONDAY. THERE ARE
PLENTY OF ISSUES TO WORK OUT DURING THIS TIME FRAME. THE GEM IS THE
MOST AGGRESSIVE WITH PUSHING THE FRONT SE AND HAS IT ALIGNED FROM
LAKE CHARLES LA TO THE STHRN TIP OF OH BY 6Z MONDAY.
CONVERSELY...THE GFS IS THE SLOWEST AND HAS IT FROM TEXARKANA TO THE
MO BOOTHEEL TO DETROIT. THE ECMWF IS IN BETWEEN. THIS HAS MAJOR
IMPLICATIONS ON PLACEMENT OF PRECIP AND DEPTH OF COLD AIR WHICH
DETERMINES P-TYPE. THE GFS SOLUTION WOULD MEAN PLENTY OF COLD RAIN
WHILE THE GEM SOLUTION KEEPS MOST OF THE PRECIP SE OF THE CWA. RIGHT
NOW I DON`T HAVE ENOUGH TO GO ON TO MAKE AN EDUCATED GUESS AS TO
WHICH SOLUTION IS RIGHT. IT ALL DEPENDS ON HOW FAR SE THE FRONT CAN
GET BEFORE IT GETS HUNG UP AND ONLY TIME WILL TELL. THERE ARE
INDICATIONS THAT THE FRONT MAY BECOME STATIONARY TO OUR SE FOR A
PORTION OF THE UPCOMING WEEK. AGAIN...DEPENDING ON WHERE IT SETS UP
WILL BE CRITICAL FOR OUR SE ZONES UNTIL THE FRONT MOVES. THIS IS A
SET-UP THAT CERTAINLY BEARS WATCHING AS OVERRUNNING SITUATIONS LIKE
THIS CAN PRODUCE PLENTY OF MIXED PRECIP. ONE THING THAT IS FOR SURE
IS THAT NEXT WEEK WILL BE MUCH COLDER THAN THE CURRENT ONE. THE
ENERGY THAT GOT THE UPPER LOW MOVING WILL PHASE THE JET
STREAMS...WHICH IS WHAT ALLOWS THE ARCTIC FRONT TO SAG INTO THE CWA.
THE H500 PATTERN TRANSITIONS TO A BROAD TROF ACROSS THE CNTRL CONUS
WITH THE MEAN AXIS EXTENDING FROM HUDSON BAY SW TO THE DESERT SW FOR
THE BEGINNING OF THE WEEK. THIS SET UP DOESN/T FAVOR MOVING THE SFC
FRONT MUCH. TOWARDS THE MIDDLE OF THE WEEK...THE MEAN TROUGH ON THE
GFS IS MORE PROGRESSIVE THAN THE ECMWF WHICH STILL WANTS TO CUT OFF
THE ENERGY AT THE BASE OF THE TROUGH. PLENTY GOING ON TO WORRY ABOUT
BEFORE WE GET TO THIS POINT.
MILLER
&&
.AVIATION...
ISSUED AT 1131 PM CST TUE JAN 8 2013
PRECIPITATION OVER NORTHERN ARKANSAS AND SOUTHERN MISSOURI HAS
MADE A BIT MORE NORTHWARD PROGRESSION THIS EVENING THAN PREVIOUSLY
THOUGHT. HOWEVER...IT APPEARS THAT A MAJORITY OF THE PRECIPITATION
SHOULD REMAIN SOUTH OF TAF SITES AND THUS HAVE NOT INCLUDED
MENTION IN THIS TAF PACKAGE. HOWEVER...CANNOT RULE OUT SOME
SPRINKLES FOR KCOU...KSTL...KSUS...AND KCPS...THOUGH IMPACTS TO
VISIBILITY AND CIGS SHOULD BE MINIMAL. HAVE ALSO CONTINUED MENTION
OF LLWS FOR THE METRO TAF SITES THROUGH 10Z TONIGHT...WITH MODEL
SOUNDINGS CONTINUING TO SUPPORT LLWS CRITERIA...THOUGH IT REMAINS
MARGINAL. OTHERWISE...EXPECT VFR CONDITIONS TO PREVAIL THROUGH
THE FORECAST PERIOD...WITH SOUTHERLY WINDS BECOMING WESTERLY AS A
WEAK COLD FRONT MOVES THROUGH THE AREA...AND EVENTUALLY NORTHERLY
LATE IN THE PERIOD.
SPECIFICS FOR KSTL...
HAVE CONTINUED MENTION OF LLWS IN THE TAF THROUGH 10Z GIVEN
CONTINUED INDICATIONS FROM RAP AND LOCAL WRF MODEL SOUNDINGS OF A
LLJ AROUND 35-40KT AT 1500-2000FT. ANOTHER CONCERN TONIGHT IS THE
NORTHWARD PROGRESSION OF PRECIPITATION OVER SOUTHERN
MISSOURI...WHICH SHOULD REMAIN SOUTH OF THE TERMINAL. HOWEVER...CANNOT
RULE OUT SOME SPRINKLES AT KSTL TONIGHT...THOUGH IMPACTS WOULD BE
MINIMAL.
OTHERWISE...DRY AND VFR CONDITIONS WILL CONTINUE THROUGH A
MAJORITY OF THE FORECAST PERIOD...WITH SOUTHERLY WINDS VEERING TO
THE WEST AS A WEAK COLD FRONT PASSES...AND EVENTUALLY TO THE NORTH
BY THE END OF THE PERIOD. GIVEN TIMING INCONSISTENCIES WITH THE
NEXT SYSTEM PROGGED TO MOVE INTO THE AREA LATE WEDNESDAY
NIGHT/EARLY THURSDAY...HAVE KEPT PRECIPITATION MENTION OUT OF THE
TAF FOR NOW AND WILL DEFER TO FUTURE ISSUANCES WHEN THE TIMING
BECOMES MORE CERTAIN.
JP
&&
.CLIMATE...
ISSUED AT 349 AM CST WED JAN 9 2013
HIGH HIGH LOW
ST. LOUIS 74/1911 60/1890
COLUMBIA 67/1911 48/1890
QUINCY 58/1911 38/2007
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1151 PM CST TUE JAN 8 2013
.UPDATE...
ISSUED AT 936 PM CST TUE JAN 8 2013
PRECIP HAS HELD TOGETHER BETTER THAN PROGD BY SOME OF THE
GUIDANCE. HAVE THEREFORE INCREASED POPS ACROSS THE SRN HALF OF THE
CWA. THE NRN EDGE OF RADAR RETURNS APPEARS TO BE DISSIPATING
SOMEWHAT...BUT WILL PULL SLIGHT CHANCE POPS FURTHER NWD IN CASE
THESE RETURNS HOLD TOGETHER. RAISED TEMPS OVERNIGHT A LITTLE AS
CLOUD COVER HAS HINDERED ANY COOLING AND WITH COOLER AIR NOT
ARRIVING UNTIL WED MORNING.
ISSUED AT 704 PM CST TUE JAN 8 2013
UPDATE TO INCREASE CLOUDS THRU THE NIGHT. ALSO INCREASED POPS
ACROSS SRN PORTIONS OF THE CWA. PRECIP CURRENTLY OVER SW MO
CONTINUES TO MOVE NEWD AND SHUD REACH SRN COUNTIES LATE THIS
EVENING. GOING FORECAST MAY STILL BE TOO SLOW BASED ON LATEST
RADAR TRENDS. HOWEVER...LATEST RAP/HRRR GUIDANCE SUGGESTS FORCING
WILL DIMINISH SOMEWHAT THRU THE NIGHT WITH PRECIP BECOMING MORE
SCT THAN IS CURRENTLY. ANOTHER AREA OF CONCERN IS THE CDFNT MOVING
INTO NWRN MO. GUIDANCE SUGGESTS THIS FNT MAY HELP TO PUSH PRECIP S
OF THE REGION. BELIEVE THE FNT IS MOVING TOO SLOWLY TO HAVE MUCH
IMPACT THIS EVENING...BUT MAY MOVE PRECIP FURTHER S FASTER LATE
TONIGHT. WILL CONTINUE TO MONITOR AND UPDATE AS NEEDED.
TILLY
&&
.SHORT TERM...
ISSUED AT 335 PM CST TUE JAN 8 2013
(TONIGHT)
A NRN STREAM SHORTWAVE WILL PASS NORTH OF THE AREA TONIGHT ALTHOUGH
IT WILL DRAG A WEAK CDFNT THROUGH THE CWA. ATTM NO PCPN IS EXPECTED
WITH THE CDFNT DUE TO THE INITIALLY DRY AIR MASS PER 12Z SGF
SOUNDING...LIMITED MOISTURE ACCOMPANYING THE NRN STREAM
SHORTWAVE...AND UNFAVORABLE DYNAMICS THIS FAR SOUTH OF THE VORT MAX.
THE PRIMARY EFFECT OF THE CDFNT WILL BE TO CAUSE WINDS TO VEER FM
SLY TO WLY OVERNIGHT. ALTHOUGH THE NAM/SREF SEEM TO BE OVERDOING THE
LOW LEVEL MOISTURE BASED ON THE LATEST OBS...MID-LEVEL MOISTURE
SHOULD BEGIN MOVING NWD TONIGHT IN RESPONSE TO A STRONG LOW PRESSURE
SYSTEM IN NRN MEXICO/SRN TX. SOME PCPN HAS ALREADY DVLPD OVER AR
AHEAD OF THE SRN SYSTEM AND IT IS POSSIBLE THAT THERE MAY BE ENOUGH
LIFT TO SUPPORT A FEW SPRINKLES ACROSS THE SRN CWA.
KANOFSKY
&&
.LONG TERM...
ISSUED AT 335 PM CST TUE JAN 8 2013
(WEDNESDAY THROUGH TUESDAY)
A GOOD POTENTIAL FOR SIGNIFICANT QPF IS EXPECTED FOR WED NGT THROUGH
THU NGT AS THE UPPER LEVEL LOW OVER OLD MEXICO MOVES SLOWLY NEWD
THROUGH THE SRN PLAINS WED AND WED NGT...THEN EVENTUALLY MOVES
NEWD THROUGH MO THU NGT. PREFER THE MORE NRN SOLUTION OF THE 500
MB LOW TRACK OF THE NAM AND ECMWF MODELS OVER THE GFS. MOST OF THE
PRECIPITATION SHOULD REMAIN S OF OUR FORECAST AREA ON WED...BUT
THEN SPREAD NEWD INTO MUCH OF THE REGION WED NGT AS A STRONG SLY
LOW LEVEL JET BRINGS LOW LEVEL MOISTURE NWD INTO MUCH OF MO AND
SRN IL. SHOWERS AND AT LEAST A FEW THUNDERSTORMS CAN BE EXPECTED
ON THU AS A WEAK SFC LOW AND WARM FRONT LIFT NWD INTO SRN
MO...WITH INCREASING UPPER LEVEL DIVERGENCE OVER OUR AREA AHEAD OF
THE APPROACHING UPPER LEVEL TROUGH. MUCH OF THE PRECIPITATION
SHOULD SHIFT E OF OUR AREA BY LATE THU NGT AS THE UPPER LEVEL LOW
OPENS UP AND WEAKENS AS IT MOVES TOWARDS THE GREAT LAKES REGION.
UNSEASONABLY WARM WEATHER WILL CONTINUE ON FRI WITH S-SWLY LOW
LEVEL WINDS ALONG WITH A CLEARING SKY. BOTH THE NAM AND ECMWF
MODELS FORECAST 850 MB TEMPERATURES OF AROUND 12 DEGREES C BY 00Z
SAT ACROSS MUCH OF OUR AREA. WILL LIKELY HAVE HIGHS IN THE LOWER
60S ACROSS MOST OF THE AREA ON FRI. SAT WILL BE THE LAST DAY OF
ABOVE NORMAL TEMPERATURES AS A COLD FRONT DROPS SOUTHEASTWARD
THROUGH OUR FORECAST AREA LATE FRI NGT AND SAT. ALTHOUGH THE FRONT
SHOULD MOVE THROUGH DRY THE MODELS DO GENERATE POST FRONTAL
PRECIPITATION SAT NGT AS A WEAK SFC WAVE MOVES ALONG THE FRONT
WITH AN APPROACHING POSITIVELY TILTED UPPER LEVEL TROUGH WELL WEST
OF THE AREA. LOOKS LIKE MOST OF THE PRECIPITATION WILL BE ACROSS
SERN MO AND SWRN IL IN THE WARMER AIR...BUT COULD NOT RULE OUT A
LITTLE LIGHT SNOW N AND W OF STL IN THE COLDER AIR. THE POTENTIAL
FOR AT LEAST LIGHT PRECIPITATION MAY CONTINUE ACROSS SERN MO AND
SWRN IL UNTIL MON WHEN A STRONG SFC RIDGE OVER THE NRN PLAINS
FINALLY BUILDS SEWD INTO MO WITH THE COLD FRONT SHIFTING WELL SE
OF OUR AREA. MUCH COLDER...MORE SEASONAL TEMPERATURES CAN BE
EXPECTED SUN THROUGH TUE.
GKS
&&
.AVIATION...
ISSUED AT 1131 PM CST TUE JAN 8 2013
PRECIPITATION OVER NORTHERN ARKANSAS AND SOUTHERN MISSOURI HAS
MADE A BIT MORE NORTHWARD PROGRESSION THIS EVENING THAN PREVIOUSLY
THOUGHT. HOWEVER...IT APPEARS THAT A MAJORITY OF THE PRECIPITATION
SHOULD REMAIN SOUTH OF TAF SITES AND THUS HAVE NOT INCLUDED
MENTION IN THIS TAF PACKAGE. HOWEVER...CANNOT RULE OUT SOME
SPRINKLES FOR KCOU...KSTL...KSUS...AND KCPS...THOUGH IMPACTS TO
VISIBILITY AND CIGS SHOULD BE MINIMAL. HAVE ALSO CONTINUED MENTION
OF LLWS FOR THE METRO TAF SITES THROUGH 10Z TONIGHT...WITH MODEL
SOUNDINGS CONTINUING TO SUPPORT LLWS CRITERIA...THOUGH IT REMAINS
MARGINAL. OTHERWISE...EXPECT VFR CONDITIONS TO PREVAIL THROUGH
THE FORECAST PERIOD...WITH SOUTHERLY WINDS BECOMING WESTERLY AS A
WEAK COLD FRONT MOVES THROUGH THE AREA...AND EVENTUALLY NORTHERLY
LATE IN THE PERIOD.
SPECIFICS FOR KSTL...
HAVE CONTINUED MENTION OF LLWS IN THE TAF THROUGH 10Z GIVEN
CONTINUED INDICATIONS FROM RAP AND LOCAL WRF MODEL SOUNDINGS OF A
LLJ AROUND 35-40KT AT 1500-2000FT. ANOTHER CONCERN TONIGHT IS THE
NORTHWARD PROGRESSION OF PRECIPITATION OVER SOUTHERN
MISSOURI...WHICH SHOULD REMAIN SOUTH OF THE TERMINAL. HOWEVER...CANNOT
RULE OUT SOME SPRINKLES AT KSTL TONIGHT...THOUGH IMPACTS WOULD BE
MINIMAL.
OTHERWISE...DRY AND VFR CONDITIONS WILL CONTINUE THROUGH A
MAJORITY OF THE FORECAST PERIOD...WITH SOUTHERLY WINDS VEERING TO
THE WEST AS A WEAK COLD FRONT PASSES...AND EVENTUALLY TO THE NORTH
BY THE END OF THE PERIOD. GIVEN TIMING INCONSISTENCIES WITH THE
NEXT SYSTEM PROGGED TO MOVE INTO THE AREA LATE WEDNESDAY
NIGHT/EARLY THURSDAY...HAVE KEPT PRECIPITATION MENTION OUT OF THE
TAF FOR NOW AND WILL DEFER TO FUTURE ISSUANCES WHEN THE TIMING
BECOMES MORE CERTAIN.
JP
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
140 AM CST WED JAN 9 2013
.DISCUSSION...
HAVE ISSUED A WIND ADVISORY THROUGH 12Z THIS MORNING ALONG AND
WEST OF THE RED RIVER VALLEY. GETTING WINDS GUSTING TO 45MPH AT
TIMES WITH A PRESSURE RISE MAX MOVING INTO THE AREA. ALSO GETTING
SOME BLOWING SNOW IN THE NORTH.
&&
.AVIATION...
WIND GUSTS COMING NOW AND WILL BE WITH US THRU THE NIGHT IN
DVL/GFK/FAR/TVF SITES....SPREADING FROM WEST TO EAST. HIGHEST
WINDS LIKELY AT DVL 04Z-07Z WITH NR 40 KTS FROM WEST- NORTHWEST
DIRECTION. WINDS WILL DIMINISH BY 12Z. CLOUDS MOVING IN AFTER
CLEARING MOSTLY IN THE MVFR RANGE AND THESE SHOULD CLEAR OUT OF NE
ND 11Z-14Z PERIOD.
&&
.PREV DISCUSSION... /ISSUED 922 PM CST TUE JAN 8 2013/
DISCUSSION...
SFC OBS SHOW THE MAIN SFC TROUGH NOW MOVING THROUGH THE RED RIVER
VALLEY. WATER VAPOR SHOWS UPPER LOW AND SFC LOW NORTHWEST OF
WINNIPEG AND A SURGE OF CLOUDS AND WINDS ON THE BACKSIDE OF THE
LOW MOVING FROM REGINA AREA WHERE IT WAS LATE THIS AFTN THEN INTO
NW ND 00Z-01Z...THEN NOW MOVING THRU RUGBY-ROLLA AT 02-03Z. THIS
SURGE OF CLOUDS ROTATING EAST-SOUTHEAST AROUND THE LOW IN MANITOBA
WILL CONTINUE TO MOVE INTO NE ND/NRN RRV THRU 06Z. NAM 3 HR
PRESSURE RISES SHOWS A HEALTHY 5 MB/3 HR PRESSURE RISE INTO NE ND
06Z-09Z PERIOD AND 1000-850 MB LOW LEVEL LAPSE RATES DECENT (7 TO
8C/KM) MOVING THRU AS WELL. THIS IS ENOUGH FOR A 3-4 HR PERIOD OF
GOOD MIXING OF THE 45-50 KTS 925-850 MB LAYER. SEEING WIND GUSTS
TO 40 KTS OR HIGHER AT KMIB...CYBR AND NR THAT AT KRUG (RUGBY). DO
EXPECT THIS PERIOD OF WIND GUSTS TO NR 40 KTS TO SPREAD EAST
THE NEXT FEW HOURS. DUE TO RATHER SHORT NATURE OF EVENT AND ALSO
BECAUSE IT IS CAUSING SLICK ROADS DUE TO DRIFTING...COORD WITH WFO
BIS AND ISSUED A SPECIAL WX STATEMENT FOR AREAS ALONG AND NORTH OF
COOPERSTOWN-HILLSBORO LINE.
OTHERWISE...TEMPS STILL MILD BUT WILL FALL OFF LATER AS COOLER AIR
MOVES IN WITH STRATOCU. LATEST RAP AND 00Z NAM ALL SHOW CLEARING
MOVING BACK IN BEHIND CLOUDS INTO NE ND TOWARD 12Z. CLOUDS TO
CLEAR OUT OF NW MN MORE TOWARD 15Z WED.
PREV DISCUSSION... /ISSUED 300 PM CST TUE JAN 8 2013/
SHORT TERM...
MAIN FORECAST HEADACHES FOR THE PERIOD WILL BE ENDING OF PRECIP
ALONG WITH WINDS TONIGHT...AND THEN WHAT HAPPENS WITH THE SYSTEM
COMING IN THURSDAY/FRIDAY.
AN UPPER LOW CURRENTLY ROTATING ALONG THE SASKATCHEWAN/MANITOBA
BORDER WILL CONTINUE EASTWARD INTO ONTARIO TONIGHT. THE SFC LOW
WILL MOVE EASTWARD ALSO...BRINGING A STRONG GRADIENT WITH WEST
WINDS. DEFORMATION BANDS THAT ARE CURRENTLY PRODUCING SNOW OVER
THE RED RIVER VALLEY AND POINTS EASTWARD WILL CONTINUE TO MOVE
EAST THIS EVENING. WILL MAKE LAST MINUTE ADJUSTMENTS FOR GOING
RADAR TRENDS...BUT FOR NOW WILL KEEP HIGH POPS OVER ONLY THE
NORTHEASTERN CWA THIS EVENING. SOME OF THE MODELS SHOW SIGNS OF
SOME WRAP AROUND SNOW SHOWERS TOWARDS MORNING SO KEPT THE 20 POPS
GOING IN THAT AREA AFTER MIDNIGHT.
ANOTHER ISSUE TONIGHT WILL BE WINDS. A FEW OF THE MODELS HAVE
VALUES APPROACHING WIND ADVISORY CRITERIA...PARTICULARLY OVER THE
DEVILS LAKE BASIN DURING THE 00Z TO 06Z TIME FRAME. ON ONE HAND
THERE WILL BE A FAIRLY TIGHT PRESSURE GRADIENT AND DECENT
SUBSIDENCE ON THE BACK SIDE OF THE DEPARTING LOW. ON THE OTHER
HAND...THE BEST WINDS ALOFT WILL BE COMING THROUGH DURING A PERIOD
WITH NOT MUCH MIXING...AND COLD AIR ADVECTION IS NOT AS STRONG AS
IT COULD BE. WILL MONITOR OBS DURING THE NEXT HOUR OR SO...BUT FOR
NOW WILL KEEP WINDS SUB ADVISORY CRITERIA BUT MENTION BLOWING SNOW
IN THE NORTHWEST PORTION OF THE CWA.
TOMORROW SHOULD BE FAIRLY QUIET AS UPPER RIDGING BRIEFLY BUILDS
INTO THE PLAINS. ANOTHER SFC LOW WILL DEVELOP OVER
SASKATCHEWAN...WITH SOUTHERLY WINDS AND WARM AIR ADVECTION KICKING
IN BY AFTERNOON. AIR MASS WILL CONTINUE TO BE FAIRLY MILD SO KEPT
HIGHS IN THE 20S. TEMPS SHOULD REMAIN FAIRLY WARM THROUGH
WEDNESDAY NIGHT AS SOUTHERLY WINDS PICK UP AS THE SFC TROUGH OVER
SOUTH CENTRAL CANADA DEEPENS. MODELS BRING IN SOME VERY WARM AIR
AT 850MB...UP CLOSE TO 10 C OVER THE SOUTHERN CWA. EVEN WITH A
FAIRLY LARGE INVERSION TEMPS WEDNESDAY NIGHT SHOULD STAY IN THE
UPPER TEENS TO LOW 20S.
THE NEXT QUESTION IS WHAT WILL HAPPEN WITH THE SYSTEMS COMING
THROUGH THURSDAY/FRIDAY. THE MODELS ALL ARE IN FAIRLY GOOD
AGREEMENT ON THE GENERAL PATTERN...BRINGING AN UPPER LOW FROM
TX/OK INTO THE UPPER MIDWEST AND THEN A LARGER TROUGH INTO THE
WESTERN PLAINS BY FRIDAY. HOWEVER...AS FAR AS SPEED AND WHEN
PRECIP STARTS MOVING INTO THE AREA MODEL SOLUTIONS ARE ALL OVER
THE PLACE. THE NAM IS FASTEST AND HAS PRECIP ENTERING THE
SOUTHEASTERN CWA BY THURSDAY AFTERNOON...WHILE THE GFS IS MUCH
SLOWER WITH THE SOUTHERN SYSTEM AND DOESN`T BRING PRECIP INTO THAT
AREA UNTIL LATE THURSDAY NIGHT INTO FRIDAY MORNING. THE NAM IS AN
OUTLIER BUT THE GFS SEEMS A BIT SLOW...SO LEANED MORE TOWARDS A
MIDDLE OF THE ROAD ECMWF/GEM SOLUTION. KEPT POPS VERY LOW BEFORE
00Z FRIDAY WITH INCREASING CHANCES THROUGHOUT THE NIGHT. WITH
FAIRLY WARM TEMPS IN PLACE AS THE SYSTEM ARRIVES...SOME
RAIN/FREEZING RAIN IS A POSSIBILITY IN THE SOUTHEASTERN CWA AS THE
PRECIP BEGINS. THINK THAT PRECIP SHOULD CHANGE OVER TO SNOW ON
FRIDAY AS A STRONG COLD FRONT BEGINS TO SLOWLY PUSH INTO THE AREA.
KEPT POPS IN THE HIGH CHANCE CATEGORY FOR FRIDAY GIVEN FAIRLY HIGH
UNCERTAINTY BUT LATER SHIFTS WILL HAVE TO REEVALUATE. FRIDAY
COULD SEE FALLING TEMPS IN THE AFTERNOON AS COLD AIR CONTINUES TO
PUSH INTO THE NORTHERN PLAINS.
LONG TERM (FRI NIGHT THRU TUE)...
MAJOR LONG RANGE GUIDANCE IN AGREEMENT DEPICTING SOUTHWEST FLOW AT
BEGINNING OF PERIOD MOVING A COLORADO SURFACE CYCLONE TO THE
VICINITY OF NORTHERN MINNESOTA/WISCONSIN EARLY SATURDAY. COLDER AIR
WILL BE IN PLACE IN THE WAKE OF THE EARLIER WARM UP...THIS IN TANDEM
WITH H500/H700 LOWS PROXIMAL TO THE RED RIVER VALLEY WOULD PORTEND A
MEASURABLE SNOW EVENT FROM LATE FRIDAY INTO THE FIRST PART OF
SATURDAY. LONG WAVE UPPER TROUGH LAGGING BEHIND THIS SYSTEM WILL
SWING THROUGH LATER IN THE WEEKEND BRINGING DOWN ARCTIC AIR AS
NORTHWEST FLOW ESTABLISHES ITSELF EARLY NEXT WEEK. LOWERED ALL BLEND
TEMPS JUST A TAD DURING THIS PERIOD IN AN ATTEMPT TO ACCOUNT FOR
SEVERAL INCHES OF PRISTINE SNOWFALL.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WIND ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR NDZ006>008-
014>016-024-026>030-038-039-049-052>054.
MN...WIND ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR MNZ001>005-
007-008-013>015-022-027-029-030-040.
&&
$$
DK
AREA FORECAST DISCUSSION
NWS PORTLAND OR
910 PM PST TUE JAN 8 2013
.SYNOPSIS....RAIN WILL CONTINUE ALONG THE NORTH COAST TONIGHT...WITH
MANY AREAS DRY. A COLD FRONT WILL DROP SE THROUGH THE REGION WED FOR
A ROUND OF VALLEY RAIN AND FAIRLY LOW SNOW LEVELS. A COLD UPPER
TROUGH WILL FOLLOW THE FRONT WED NIGHT AND THU FOR A CHANCE OF RAIN
AND SNOW SHOWERS. NORTHERLY FLOW ALOFTWILL KEEP A COOL AIR MASS IN
PLACE THROUGH THE REMAINDER OF THE WEEK WITH A CHANCE OF SNOW
SATURDAY...THEN A DRYING TREND ENSUES FOR NEXT WEEK.
&&
.SHORT TERM...A COLD FRONT IS STILL ON TRACK TO PUSH SOUTHEASTWARD
ACROSS THE AREA LATE TONIGHT INTO WEDNESDAY MORNING. MODELS AGREE
THIS FRONT WILL REMAIN PROGRESSIVE AS IT PUSHES THROUGH THE REGION.
THE HRRR SHOWS THE FRONT MOVING ACROSS THE PORTLAND METRO AREA AROUND
5AM...AND CLEARING THE CWA BY 11AM. THIS SHOULD RESULT IN SNOW LEVELS
BEHAVING...AND AS SUCH ONLY TWEAKED THE INHERITED FORECAST.
WINDS HAVE BEEN GUSTY ALONG THE COAST AND EXPECT THEM TO PICK UP JUST
A BIT MORE IN THE NEXT HOUR OR TWO BEFORE BEGINNING TO WANE FROM
NORTH TO SOUTH AROUND MIDNIGHT. THERE MAY BE AN ISOLATED GUST TO
60MPH ALONG AN EXPOSED HEADLAND...BUT WINDS ARE EXPECTED TO TOP OUT
IN THE 50 MPH RANGE FOR THE POPULATED AREAS.
A BURST OF WIND...GENERALLY GUSTS IN THE 35 TO 45 MPH RANGE WILL
LIKELY OCCUR IN THE WILLAMETTE VALLEY WITH FRONTAL PASSAGE LATE
TONIGHT.
WENT AHEAD AND INCLUDED THE LANE COUNTY CASCADES IN THE WINTER WX
ADVISORY AS THE LATEST MODEL RUNS SUGGEST THEY WILL SEE SIMILAR QPF
AS THEIR COUNTERPARTS TO THE NORTH.
HELD OFF ON ISSUING WINTER WX ADVISORIES FOR THE COAST RANGE AND
CASCADE FOOTHILLS DUE TO QPF DECREASING SUBSTANTIALLY BY THE TIME
SNOW LEVELS DIP BELOW 1500 FT. OROGRAPHICS BECOME INCREASINGLY LESS
FAVORABLE WEDNESDAY NIGHT INTO THURSDAY MORNING AS THE FLOW BECOMES
INCREASINGLY NORTHERLY.
ANY PASSING VORT MAX IN THE UNSTABLE AIR MASS COULD AID IN ORGANIZING
SHOWER ACTIVITY WEDNESDAY NIGHT INTO THURSDAY. TRYING TO PIN POINT
WHERE OR EVEN IF ONE WILL MOVE THROUGH THE AREA AT THIS POINT IS
SOMEWHAT A LOST CAUSE THIS FAR OUT. AS SUCH...KEPT POPS GENERALLY IN
THE 40 TO 60 RANGE DURING THIS TIME. SNOW LEVELS WILL BE LOW ENOUGH
THAT JUST ABOUT ANYONE COULD SEE SOME SNOW WITH A PASSING SHOWER BY
THURSDAY MORNING...BUT WIDESPREAD ACCUMULATING SNOW IS NOT EXPECTED
AT THIS TIME. /NEUMAN
.LONG TERM...FRIDAY AFTERNOON THROUGH MONDAY NIGHT... AN UPPER LEVEL
RIDGE REMAINS OFFSHORE WITH COOL NORTHERLY FLOW ALOFT MOVING OVER
THE PACIFIC NORTHWEST. THE MODERATE TO STRONG NORTHERLY FLOW IS AT
THE BACK EDGE OF AN EXITING COLD AIR MASS TO THE EAST WITH SHOWERS
ENDING FRIDAY AS A SYSTEM EXITS THE AREA. MODELS DIFFER IN THE
DETAILS OF A SHORT WAVE TROUGH MOVING OVER THE TOP OF THE RIDGE
EARLY IN THE WEEKEND AND TO THE OREGON/WASHINGTON BORDER BY LATE
SAT. DEPENDINGON THE DEVELOPMENT OF THE LOW ASSOCIATED WITH THE
TROUGH...IT COULD POTENTIALLY GENERATE ENOUGH CIRCULATION AND BRING
ENOUGH MOISTURE TO THE AREA TO DROP A LITTLE BIT OF SNOW OVER THE CWA
DURING THE WEEKEND. THE SYSTEM MOVES THROUGH THE AREA FAIRLY RAPIDLY.
CURRENTLY THE ECMWF IS THE MODEL SHOWING DEVELOPMENT OF THE LOW
PRESSURE SYSTEM THAT IS MORE PROMISING FOR AN INCH OR SNOW AT LOWER
ELEVATIONS...WHILE THE GFS TENDS TO REFLECT A MUCH WEAKER FEATURE AT
THE SURFACE. THE TREND TOWARD THE BEGINNING OF NEXT WEEK IS TOWARD
THE HIGH PROGRESSING VERY SLOWLY WESTWARD...AND BRINGING SLIGHTLY
WEAKER NORTHERLY FLOW TO THE AREA. KWELSON
&&
.AVIATION...CONDITIONS SHOULD REMAIN PRIMARILY VFR TONIGHT ACROSS
THE INTERIOR IN A WELL-MIXED MILD AIRMASS. THE MAIN EXCEPTIONS TO
THIS WILL BE IN THE SOUTH WILLAMETTE VALLEY AND NEAR THE COLUMBIA
RIVER WHERE MVFR STRATUS MAY FORM AFTER 08Z. EXPECT A MIX OF MVFR
AND IFR CONDITIONS ALONG THE COAST TONIGHT IN INCREASING RAIN.
THIS RAIN WILL PUSH INLAND EARLY WEDNESDAY MORNING AS A STRONG
COLD FRONT PUSHES ONSHORE FROM ABOUT 9Z TO 12Z ALONG THE COAST
AND 12Z TO 15Z INLAND. THEN CONDITIONS MAY IMPROVE BEHIND THE
FRONT IN THE AFTERNOON AS WE REMAIN IN A SHOWERY W/NW FLOW
PATTERN.
KPDX AND APPROACHES...EXPECT MAINLY VFR CONDITIONS OVERNIGHT WITH
DRY CONDITIONS AND SOUTHERLY WINDS. CONDITIONS WILL DETERIORATE
BETWEEN 12Z AND 15Z AS A STRONG COLD FRONT SPREADS RAIN INLAND.
SOME IMPROVEMENT MAY OCCUR LATER IN THE AFTERNOON BEHIND THE FRONT
AS WINDS TURN NORTHWESTERLY.
&&
.MARINE...GUSTY WINDS SHOULD CONTINUE THROUGH TONIGHT...WITH GUSTS
IN THE 35 TO 40 KT RANGE. LOCALIZED AREAS OF STRONGER WINDS ARE
POSSIBLE FROM TIME TO TIME THROUGH THIS EVENING IN THE NORTHERN
NEARSHORE WATERS. WINDS WILL TURN W/NW AND DROP OFF SOMEWHAT
BEHIND THE FRONT...ROUGHLY BETWEEN 09Z AND 12Z IN THE NORTHERN
WATERS AND 09Z TO 12Z IN THE SOUTHERN WATERS. WINDS MAY STRENGTHEN
AGAIN TO SMALL CRAFT ADVISORY LEVELS OVER THE OUTER WATERS LATER
WEDNESDAY IN A BREEZY POST-FRONTAL AIRMASS.
SEAS ARE CURRENTLY IN THE MID TEENS AND SHOULD HOLD ABOVE 10 FEET
THROUGH THE END OF THE WEEK. SEAS MAY SUBSIDE TO BELOW 10 FEET BY
THE WEEKEND.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...WINTER WEATHER ADVISORY FROM 7 AM WEDNESDAY TO MIDNIGHT PST
WEDNESDAY NIGHT FOR CASCADES IN LANE COUNTY-NORTHERN OREGON
CASCADES.
WA...WINTER WEATHER ADVISORY FROM 4 AM WEDNESDAY TO MIDNIGHT PST
WEDNESDAY NIGHT FOR SOUTH WASHINGTON CASCADES.
PZ...GALE WARNING UNTIL 4 AM PST WEDNESDAY FOR COASTAL WATERS FROM
CAPE SHOALWATER WA TO CASCADE HEAD OR OUT 60 NM.
GALE WARNING UNTIL 7 AM PST WEDNESDAY FOR COASTAL WATERS FROM
CASCADE HEAD OR TO FLORENCE OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 4 PM PST
WEDNESDAY.
&&
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 SAN ANGELO TX
1133 PM CST TUE JAN 8 2013
.UPDATE...
THE LATEST SATELLITE AND WSR-88D DATA INDICATE THE UPPER-LEVEL
SYSTEM REMAINS POSITIONED FOR MAINLY SHOWERS TO CONTINUE ACROSS
WEST CENTRAL TEXAS FOR THE REMAINDER OF TONIGHT. SO FAR...WE HAVE
NOT RECEIVED THE WIDESPREAD HIGHER-AMOUNTS RAINFALL WE WERE
ANTICIPATING. HOWEVER...THE LATEST RUC DATA INDICATE THE AREA OF
PRECIPITATION WILL CONTINUE TO EXPAND FARTHER NORTH ACROSS WEST
CENTRAL TEXAS FOR THE REMAINDER OF TONIGHT. GIVEN PAST TRENDS AND
NEW MODEL DATA...I DECIDED TO CONTINUE CATEGORICAL POPS ACROSS THE
BOARD FOR THE REMAINDER OF TONIGHT. I DID MAKE A COUPLE CHANGES.
I REPLACED THE RAIN SHOWERS PLUS IN OUR WEATHER GRIDS WITH RAIN
SHOWERS MODERATE. THIS REMOVED THE LOCALLY HEAVY RAINFALL ZONE
FORECAST PRODUCT WORDING FOR TONIGHT. PLUS...I REMOVED
THUNDERSTORMS FROM ALL BUT THE NORTHWEST HILL COUNTRY AND SOME OF
THE HEARTLAND FOR THE REMAINDER OF TONIGHT. WITH WATER VAPOR
IMAGERY INDICATING A BETTER DEFINED DEFORMATION ZONE DEVELOPING
OVER WEST CENTRAL TEXAS...THE THUNDERSTORM POTENTIAL HAS DECREASED
FOR MOST OF WEST CENTRAL TEXAS FOR TONIGHT. THE LATEST ZONE
FORECAST AND POINT FORECAST MATRICES PRODUCTS REFLECT THESE
GRIDS CHANGES.
HUBER
&&
.PREV DISCUSSION... /ISSUED 509 PM CST TUE JAN 8 2013/
DISCUSSION...
SEE 00Z AVIATION DISCUSSION BELOW.
AVIATION...
IFR TO LIFR CONDITIONS WILL PREVAIL OVER THE NEXT 24 HOURS. HAVE
ONLY INCLUDED RAIN AND LIGHT RAIN IN THE TAFS WITH NO MENTION OF
THUNDER. ANY THUNDERSTORMS LOOK TO BE ISOLATED AND IT IS UNCERTAIN
THAT ANY WILL IMPACT ANY TERMINALS. THE BEST CHANCES WOULD BE AT
JUNCTION AND BRADY. WILL CONTINUE TO MONITOR AND WILL AMEND TAFS
AS NEEDED. EXPECTING WINDS OUT OF THE NORTHEAST AROUND 10 KNOTS.
21
PREV DISCUSSION... /ISSUED 330 PM CST TUE JAN 8 2013/
SHORT TERM...
THE MAIN FORECAST PROBLEM FOR THE SHORT TERM IS THE CONTINUING RAIN
THREAT ACROSS WEST CENTRAL TEXAS. LIGHT RAIN HAS FALLEN ACROSS THE
AREA THROUGH MUCH OF THIS MORNING AND MORE IS DEVELOPING SOUTH OF
THE AREA. BEST CHANCES FOR RAIN LOOKS TO BE THIS EVENING AND
OVERNIGHT TONIGHT AS THE LOW OVER NORTHERN MEXICO PUSHES FURTHER
INTO WEST TEXAS. HPC STANDARD ANOMALIES ARE STILL SHOWING A MODEL
CONSENSUS OF 1 TO 2 STANDARD DEVIATIONS ABOVE NORMAL FOR
PRECIPITABLE WATER. FOR QPF I USED THE HPC GUIDANCE AS IT IS IN GOOD
AGREEMENT WITH BOTH THE NAM AND THE ECMWF. I HAVE LITTLE CONFIDENCE
IN THE GFS SOLUTION AS IT IS MUCH HIGHER THAN THE NAM OR ECMWF AND
THE GEFS MEAN PRECIP IS DOWN PLAYING THESE HIGHER AMOUNTS. RAIN MAY
BE HEAVY AT TIME REDUCING VISIBILITIES TO LESS THAN ONE MILE. MOST
AREAS CAN EXPECT 1 TO 2 INCHES OF RAIN AND SOME LOCATIONS MAY SEE
UP TO 3 INCHES. TEMPERATURES LOOK TO STAY IN THE MID 40S...MOSTLY
DUE TO THE THE OVERCAST SKIES THAT ARE EXPECTED. HIGHS WILL BE
LITTLE WARMER TOMORROW AS THE RAIN MOVES OUT BUT ONLY EXPECT A
COUPLE OF DEGREES MORE.
13
LONG TERM...
THE UPPER LEVEL LOW WILL BE MOVING FROM NORTHERN MEXICO NORTHEAST
OVER THE SOUTHERN FORECAST AREA BY THURSDAY EVENING WITH THE GFS
AND ECMWF FAIRLY CLOSE IN TIMING AND THE NAM A LITTLE FASTER. HAVE
GONE WITH A BLEND OF THE TIMING GRADUATING RAIN CHANCES FROM 30
POPS OVER THE SOUTHERN CWA TO 70S POPS OVER THE NORTHERN CWA
THROUGH MIDNIGHT WEDNESDAY WITH THE CHANCE OF SHOWERS ENDING FROM
THE SOUTH TO THE NORTH THROUGH WEDNESDAY NIGHT. HAVE KEPT A SLIGHT
CHANCE OF RESIDUAL SHOWERS OVER THE BIG COUNTRY THURSDAY MORNING.
THE UPPER LEVEL LOW WILL OPEN AS IT MOVES NORTHEAST AND MERGES WITH
THE SOUTHWEST FLOW ALOFT BY THE END OF THE WEEK. THE FORECAST AREA
WILL REMAIN UNDER A SOUTHWEST FLOW ALOFT AS ANOTHER UPPER TROUGH
DIGS OVER THE WESTERN STATES. THE UPPER WESTERN TROUGH WILL BE SLOW
TO MOVE EAST WITH THE TROUGH AXIS WEST OF THE FORECAST AREA
THROUGH THE END OF THE EXTENDED. THE NEXT COLD FRONTAL PASSAGE
WILL BE SATURDAY WITH THE ECMWF AND GFS SHOWING A SLIGHT CHANCE OF
ASSOCIATED RAINFALL OVER THE EASTERN CWA SATURDAY INTO SUNDAY.
WILL LEAVE THE FORECAST DRY FOR NOW AND AWAIT ADDITIONAL MODEL
RUNS BEFORE INCLUDING ANY RAINFALL.
WILL SEE A NICE WARM-UP THURSDAY AND FRIDAY IN ADVANCE OF THE NEXT
COLD FRONT WITH HIGHS ON THURSDAY IN THE 60S AND IN THE UPPER 60S
TO THE LOWER 70S ON FRIDAY. BY THE BEGINNING OF THE COMING WEEK
POSTFRONTAL AFTERNOON HIGHS WILL BE MOSTLY IN THE 40S. MORNING
LOWS WILL COOL INTO THE 20S BY SUNDAY AND WILL REMAIN IN THE 20S
THROUGH THE MIDDLE OF THE COMING WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
ABILENE 45 50 37 58 41 / 90 90 50 20 5
SAN ANGELO 44 48 37 62 38 / 90 80 40 10 5
JUNCTION 45 54 38 66 38 / 100 80 30 10 0
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
HUBER
AREA FORECAST DISCUSSION
NWS EUREKA CA
437 AM PST WED JAN 9 2013
.SYNOPSIS...A COLD FRONT WILL BRING A QUICK SHOT OF RAIN THIS
MORNING. SNOW LEVELS WILL FALL RAPIDLY THIS AFTERNOON BEHIND THE
FRONT AS SHOWERS AND ISOLATED THUNDERSTORMS IMPACT THE REGION. ANOTHER
DISTURBANCE WILL MAINTAIN SHOWER ACTIVITY INTO THE WEEKEND BEFORE
A BUILDING UPPER LEVEL RIDGE BRINGS DRIER WEATHER TO THE REGION EARLY
NEXT WEEK.
&&
.DISCUSSION...SAT IMAGERY SHOWS UPPER TROUGH MOVG PAST 130W EARLY
THIS MORNING WITH PLENTY OF OPEN CELL CU BEHIND THE ASSOCIATED
COLD FRONT. RADAR SHOWS LGT RETURNS NEAR THE ORCA BORDER WITH SFC
OBS ALREADY REPORTING INTERMITTENT LGT PRECIP NEAR THE COAST.
PERIODS OF -RA WILL CONTINUE UNTIL THE FRONT ARRIVES. EXPECT FRONT
TO MOVE INTO DEL NORTE COUNTY AROUND SUNRISE AND PUSH S AND E
THROUGH THE MORNING...EXITING CWA THIS AFTERNOON. A BRIEF BREAK
IN CLOUDS AND PRECIP BEHIND THE FRONT BEFORE SHOWERS ARRIVE LATER
THIS MORNING AND AFTERNOON. FCST SOUNDINGS CONTINUE TO SHOW
FAVORABLE DYNAMICS FOR SMALL HAIL AND ISOLD TSTMS THIS AFTERNOON
THROUGH THU MORNING. SN LEVELS INITIALLY ABOVE 5KFT THIS MORNING
WILL FALL RAPIDLY BEHIND THE FRONT AS THE ASSOCIATED COLD UPPER
TROUGH APPROACHES THE REGION. SNOW LEVELS WILL FALL TO 2500 FT BY
THIS AFTERNOON AND TO 1000 FT BY THU MORNING AS THE COLD AIRMASS
SETTLES OVER THE REGION. SHOWER ACTIVITY WILL PEAK THIS EVENING
AND OVERNIGHT AS THE TROUGH AXIS CROSSES THE REGION. RAPIDLY
FALLING SNOW LEVELS COMBINED WITH CONVECTIVE NATURE OF THE PRECIP
MAKE THE MAIN FCST CHALLENGE SNOW ACCUMULATIONS. CONTINUED TO
TREND FCST TOWARDS THE HIGHER EC AND SREF QPF SOLNS RESULTING IN
HIGHER SNOW AMT FCST. EXPECT 3-7 INCH ACCUMULATIONS IN ZONES 3
AND 4 WITH 6-10 INCHES WITH LOCALIZED AMOUNTS TO 12-15 INCHES ABOVE
3KFT...SO EXPANDED WINTER WX ADVISORY TO INCLUDE TRINITY COUNTY.
HEAVIEST PRECIP AND HIGHEST SNOW ACCUMULATIONS WILL BE ACROSS THE
SISKIYOU AND SOUTH FORK RANGES. LIGHTER ACCUMULATIONS EXPECTED
OVER MENDOCINO COUNTY WHERE 1-3 INCHES EXPECTED ABOVE 1500 FT
THROUGH THU MORNING. UPPER RIDGE WILL BEGIN TO BUILD OVER THE NE
PAC THU RESULTING IN UPPER FLOW BECOMING NLY ACROSS THE REGION.
PRECIP CHCS WILL DIMINISH AND SHIFT SLIGHTLY OFFSHORE THU
AFTERNOON AS A RESULT. A COUPLE OF MINOR PERTURBATIONS IN THE NLY
FLOW WILL MAINTAIN ISOLD TO SCT SHOWER ACTIVITY MAINLY N OF CAPE
MENDO INTO THE WEEKEND. MODELS CONTINUE TO SHOW UPPER RIDGE
SHIFTING ONSHORE EARLY NEXT WEEK...BUT 09/00Z MODELS SLOWED THIS
SLIGHTLY COMPARED TO PREV RUNS. HOWEVER...MADE LITTLE CHANGE TO
THE EXTENDED AS WARMER TEMPS AND DRIER WX EXPECTED ACROSS THE
REGION EARLY NEXT WEEK.
&&
.AVIATION...COLD FRONT APPEARS TO BE WITHIN 3 TO 5 HOURS OF
CROSSING THE NORTH COAST PER RUC ANALYSIS AND SATELLITE IMAGERY.
CIGS ARE STILL BELOW 1000FT AT KACV BUT ARE BEGINNING TO COME UP
WITH INCREASED MIXING AHEAD OF THE FRONT...JUST VFR CONDITIONS AT
KACV. EXPECT A FEW HOURS OF IMPROVED CONDITIONS BEFORE THE FRONT
ARRIVES. 2 TO 4 MI VSBYS MAY LAST AN HOUR OR SO WITH A PERIOD OF
RAIN ALONG THE COLD FRONT 15-17Z AT KACV/KCEC...A COUPLE HOURS
LATER AT KUKI. NOT EXPECTING SIGNIFICANT REDUCED VSBYS AT KUKI
TODAY THOUGH WITH LIGHTER SHOWER ACTIVITY SOUTH OF CAPE MENDOCINO.
WINDS WILL SHIFT TO THE NW IN THE WAKE OF THE FRONT BUT EXPECT
GUSTS TO BE MAINLY 15 KT OR LESS. SHOWERS LATE TODAY AND TONIGHT
WILL LIKELY CONTAIN SMALL HAIL WITH BRIEF TSRA POSSIBLE AND
TEMPORARY IFR CIGS/VSBYS POSSIBLE IN THE HEAVIER SHOWERS.
CONDITIONS WILL IMPROVE ON THURSDAY. AAD
&&
.MARINE...CANCELLED HAZ SEAS WARNING FOR THE OUTER WATERS TODAY
BUT LEFT SCA RUNNING THROUGH AT LEAST FRI MORNING. BEGINNING TO
SEE LONGER PERIOD WAVES SHOW UP 9-10 FT AT 13-14 SECS. BUOY 2
NEARING 15 FT WHICH IS AT OR JUST BELOW FCST HEIGHTS. SWAN IS
COMING IN A TOUCH LOWER AS WELL...AND WINDS ARE NOT EXPECTED TO BE
QUITE AS HIGH IN THE WAKE OF THE FRONT AND WILL TEND TO SUBSIDE
FOR AWHILE TONIGHT. NOT TO SAY THAT CONDITIONS WILL NOT BE POOR
ACROSS THE OUTER WATERS WITH SCT HEAVY SHOWERS AND ISOLATED
THUNDERSTORMS WITH SMALL HAIL AROUND...ALONG WITH 15-25 KT NW
WINDS ON TOP OF BUILDING MODERATE LONG-PERIOD SEAS. THESE SEAS
WILL ONLY TEND TO BUILD FURTHER THROUGH THURDAY. NRLY GRADIENT
WILL INCREASE AS WELL RESULTING IN WIDESPREAD 15-25 KT WINDS. EVEN
SOME GALE FORCE GUSTS LIKELY BEYOND 8-10 NM. THIS WOULD PUT
CONDITIONS SOLIDLY IN HAZ SEAS FOR TOMORROW BUT WILL LET THE DAY
SHIFT MAKE THE CALL ON WHETHER OR NOT TO HOIST A WARNING. LONG
PERIOD SEAS WILL DECAY AND SUBSIDE THROUGH THE WEEKEND BUT
MODERATE NORTHERLY WINDS 10-20 KT AND STEEPER SHORT PERIOD SEAS
WILL TEND TO PERSIST. AAD
&&
.COASTAL FLOODING...ANOTHER ROUND OF HIGH ASTRONOMICAL TIDES
EXPECTED THIS WEEK. FCST HIGH TIDES OF 8.4FT TODAY...AND 8.6FT
THU AND FRI. FCST ANOMALIES CONTINUE TO RUN SLIGHTLY LOWER THAN
FCST...INCREASING SLY WINDS EARLY THIS MORNING FOLLOWED BY FRONTAL
PASSAGE WILL LIKELY SHIFT ANOMALIES TO SLIGHTLY ABOVE FCST.
ALTHOUGH NO FLOODING IS ANTICIPATED ATTM...WILL CONTINUE TO
MONITOR FOR POTENTIAL IMPACTS...ESPECIALLY FOR THU AND FRI HIGH
TIDES.
&&
.EKA WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 4 AM PST
THU ABOVE 1500 FEET FOR CAZ004.
WINTER WEATHER ADVISORY FROM 1 PM THIS AFTERNOON TO 10 AM PST THU
ABOVE 1500 FEET FOR CAZ003.
SMALL CRAFT ADVISORY UNTIL 9 AM PST FRI FOR PZZ450-470.
SMALL CRAFT ADVISORY UNTIL 3 PM PST FRI FOR PZZ455-475.
&&
$$
VISIT US AT HTTP://WWW.WEATHER.GOV/EUREKA
FOLLOW US ON FACEBOOK AND TWITTER AT:
HTTP://WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.EUREKA.GOV
HTTP://WWW.TWITTER.COM/NWSEUREKA
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
1007 AM EST Wed Jan 9 2013
.NEAR TERM [Through Rest of Today]...
The large scale split flow long wave pattern remains highly
amplified especially across Srn stream. This is highlighted in Nrn
stream by ridging over Wrn states, trough over Wrn most Great Lakes
and ridging over Ern seaboard into adjacent Atlc. Srn stream
highlighted by trough over Srn plains with closed low over NE old
Mex and Srn TX and ridging over se region into Wrn Atlc.
At surface, morning analysis shows a low near TX with cold front swd
into SE TX, and W-E warm front extending Ewd across FL Gulf Coast.
Warm front is well defined, separating a moist tropical airmass over
the Nrn Gulf from a modified continental one that has been in place
across the SE. Dew points just S of front in low to mid 60s. It was
also responsible for generating area of fog, sprinkles and drizzle
along and north of it across our land area. Inverted coastal trough
also noted just off NE FL coast.
During the rest of today, NRN stream trough will move quickly across
Great Lakes region then Ewd towards NE states in response to next
trough that begins to dig SEWD across extreme Ern PAC into West
coast. TX low will shift NEWD across rest of TX (and eventually into
Lwr MS Valley) generating widespread convection. In response,
SE ridge builds NWD. The combination of NRN trough and lifting TX
low will accelerate cold front across TX and lift warm front NWD,
However main forcing will remain well to our west in the vicinity of
cold front. This front will also signal the beginning of a warm and
humid pattern that will last into much of next week. It will also
lift coastal trough NEWD as local winds veer.
Even with all the cloudiness and some sprinkles and drizzle in place
this morning, expect enough breaks in the cloud cover into the aftn
to support temperatures in the low to mid 70s. Latest guidance and
satellite pix suggest cloud/fog erosion from E-W next few hours. So
even though 14z-15z temps running 3-5 degrees below forecast max,
they should rebound some into aftn so won`t make any updates at this
time but monitor closely. So areas in the SE Fl Big Bend could also
get into the mid-upper 70s should more breaks develop in the
overcast. The increasingly warm and moist onshore flow moving over
cooler shelf waters of Gulf will likely continue to generate
sea fog over the marine area and adjacent coast. This is evident in
the local NAM DNG5, other guidance and satellite pix. This
reflected in latest GRIDS.
&&
.SHORT TERM [Tonight Through Friday]...
With the warm front lifting northward through the area by tonight,
the region will be in an increasingly more humid airmass, which
will likely support the formation of fog/stratus after midnight.
Temperatures will also be noticeably warmer with lows around 60
degrees.
Starting Thursday the storm system across Central Texas will
begin to move north northeast around a building mid level ridge
centered over the Florida Peninsula. As this system moves into the
Great Lakes, a weak cold front will move eastward across the
Central Gulf States. The strengthening ridge will slow the
eastward progress of this system as the main upper level energy
continues to move quickly northward. As a result, only low end
rain chances are expected Thursday night into Friday as this front
eventually dissipates across the region.
As was much the case in the near term period, the short term
period will have unseasonably warm temperatures with highs in the
low to mid 70s in the western areas (due to more cloud cover) and
in the upper 70s to near 80 in the east. Overnight lows will be
muggy by January standards, generally in the upper 50s to lower 60s.
&&
.LONG TERM [Friday Night through Tuesday]...
There is good agreement between the GFS and ECMWF that deep layer
ridging will be the dominant synoptic feature over the Southeast.
This correlates to a continuation of above-average temperatures (at
least 10 to 15 degrees warmer than climatology) away from the
beaches (where SSTs remain in the upper 50s to lower 60s). The PoP
will be in the 10 to 30% range- highest along and left of a line
from Albany to Panama City as that region will be closer to the Q-G
forcing and deep layer moisture associated with a persistent
quasi-stationary frontal system.
&&
.AVIATION [through 18z Thursday]...
Updated at 950 am EST-
MVFR cigs will persist across our area (except IFR in fog and light
rain especially at KECP and KVLD until early afternoon. Then, most
cigs will lift to high MVFR, but IFR cigs may persist all day at
KECP. Widespread LIFR (or worse) Vis & cigs are likely tonight,
beginning near the coast shortly after sunset, then spreading inland
later tonight. Our forecast is a blend of the GFS/NAM MOS and latest
HRRR, with emphasis on the HRRR (which has verified well so far this
morning) through this afternoon.
&&
.MARINE...
The pressure gradient will remain tight across the marine area as a
low pressure area lifts northward across Texas and high pressure
persists over the NE gulf. Cautionary level winds will continue
possibly into Thursday before relaxing. Lighter onshore flow is
expected by the weekend as high pressure builds just off the Florida
Peninsula.
&&
.FIRE WEATHER...
Relative humidity levels will remain too moist for red flag
conditions for at least the remainder of this week.
&&
.HYDROLOGY...
No appreciable rainfall amounts are expected through the next few
days.
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 75 61 77 59 74 / 10 10 10 20 20
Panama City 71 64 74 63 73 / 20 10 10 40 20
Dothan 71 61 75 62 75 / 30 10 10 30 20
Albany 72 60 75 62 75 / 20 10 10 20 20
Valdosta 76 61 78 60 78 / 10 10 10 10 20
Cross City 79 59 79 58 76 / 10 10 10 10 20
Apalachicola 69 64 70 63 70 / 10 10 10 30 20
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
GM...None.
&&
$$
NEAR TERM...Block
SHORT TERM...Godsey
LONG TERM...Fournier
AVIATION...Block
MARINE...Block/Godsey
FIRE WEATHER...Fournier
HYDROLOGY...Godsey
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
730 AM EST Wed Jan 9 2013
.UPDATE...
Radar and obs showing sprinkles Wrn third and drizzle Cntrl third of
area. Patchy to areas of fog also seen across much of area including
Ern 2/rd of waters. Updated GRIDS to reflected 12z-15z. Also tweaked
temps/dew points to refelct current scenario.
.NEAR TERM [Through Today]...
03 UTC surface analysis shows a frontal boundary right along the
Northern Gulf Coast. This boundary was well defined, separating a
moist tropical airmass over the Central Gulf from a modified
continental one that has been in place across the Southeast. This
frontal boundary will lift northward today as a strong upper level
system moves through Central Texas. The best forcing for ascent is
expected to remain well off to the west of our region. As a
result, only a slight chance of showers are expected today as the
warm front lifts northward.
This front will also signal the beginning of a warm and humid
pattern that will last into much of next week. Even with all the
cloudiness in place this morning, expect enough breaks in the
cloud cover to support temperatures in the low to mid 70s. Areas
in the Southeast Florida Big Bend could also get into the upper
70s should more breaks develop in the overcast.
&&
.SHORT TERM [Tonight Through Friday]...
With the warm front lifting northward through the area by tonight,
the region will be in an increasingly more humid airmass, which
will likely support the formation of fog/stratus after midnight.
Temperatures will also be noticeably warmer with lows around 60
degrees.
Starting Thursday the storm system across Central Texas will
begin to move north northeast around a building mid level ridge
centered over the Florida Peninsula. As this system moves into the
Great Lakes, a weak cold front will move eastward across the
Central Gulf States. The strengthening ridge will slow the
eastward progress of this system as the main upper level energy
continues to move quickly northward. As a result, only low end
rain chances are expected Thursday night into Friday as this front
eventually dissipates across the region.
As was much the case in the near term period, the short term
period will have unseasonably warm temperatures with highs in the
low to mid 70s in the western areas (due to more cloud cover) and
in the upper 70s to near 80 in the east. Overnight lows will be
muggy by January standards, generally in the upper 50s to lower 60s.
&&
.LONG TERM [Friday Night through Tuesday]...
There is good agreement between the GFS and ECMWF that deep layer
ridging will be the dominant synoptic feature over the Southeast.
This correlates to a continuation of above-average temperatures (at
least 10 to 15 degrees warmer than climatology) away from the
beaches (where SSTs remain in the upper 50s to lower 60s). The PoP
will be in the 10 to 30% range- highest along and left of a line
from Albany to Panama City as that region will be closer to the Q-G
forcing and deep layer moisture associated with a persistent
quasi-stationary frontal system.
&&
.AVIATION [through 12z Thursday]...
Updated at 626 am EST-
KVLD is the only site expected to have IFR Vis this morning.
Otherwise, IFR to low-end MVFR cigs will persist across our area
until early afternoon. Most cigs will lift to MVFR mid to late
afternoon, but IFR cigs may persist all day at KECP. Widespread LIFR
(or worse) Vis & cigs are likely tonight, beginning near the coast
shortly after sunset, then spreading inland later tonight. Our
forecast is a blend of the GFS/NAM MOS and latest HRRR, with
emphasis on the HRRR (which has verified well so far this morning)
through this afternoon.
&&
.MARINE...
The pressure gradient will remain tight across the marine area as
a low pressure area lifts northward across Texas. Cautionary level
winds will continue possibly into Thursday before relaxing. Lighter
onshore flow is expected by the weekend as high pressure builds
just off the Florida Peninsula.
&&
.FIRE WEATHER...
Relative humidity levels will remain too moist for red flag
conditions for at least the remainder of this week.
&&
.HYDROLOGY...
No appreciable rainfall amounts are expected through the next few
days.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 75 61 77 59 74 / 10 10 10 20 20
Panama City 71 64 74 63 73 / 20 10 10 40 20
Dothan 71 61 75 62 75 / 20 10 10 30 20
Albany 72 60 75 62 75 / 10 10 10 20 20
Valdosta 76 61 78 60 78 / 10 10 10 10 20
Cross City 79 59 79 58 76 / 10 10 10 10 20
Apalachicola 69 64 70 63 70 / 10 10 10 30 20
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
GM...None.
&&
$$
NEAR TERM...Godsey
SHORT TERM...Godsey
LONG TERM...Fournier
AVIATION...Fournier
MARINE...Godsey
FIRE WEATHER...Fournier
HYDROLOGY...Godsey
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
626 AM EST Wed Jan 9 2013
.NEAR TERM [Through Today]...
03 UTC surface analysis shows a frontal boundary right along the
Northern Gulf Coast. This boundary was well defined, separating a
moist tropical airmass over the Central Gulf from a modified
continental one that has been in place across the Southeast. This
frontal boundary will lift northward today as a strong upper level
system moves through Central Texas. The best forcing for ascent is
expected to remain well off to the west of our region. As a
result, only a slight chance of showers are expected today as the
warm front lifts northward.
This front will also signal the beginning of a warm and humid
pattern that will last into much of next week. Even with all the
cloudiness in place this morning, expect enough breaks in the
cloud cover to support temperatures in the low to mid 70s. Areas
in the Southeast Florida Big Bend could also get into the upper
70s should more breaks develop in the overcast.
&&
.SHORT TERM [Tonight Through Friday]...
With the warm front lifting northward through the area by tonight,
the region will be in an increasingly more humid airmass, which
will likely support the formation of fog/stratus after midnight.
Temperatures will also be noticeably warmer with lows around 60
degrees.
Starting Thursday the storm system across Central Texas will
begin to move north northeast around a building mid level ridge
centered over the Florida Peninsula. As this system moves into the
Great Lakes, a weak cold front will move eastward across the
Central Gulf States. The strengthening ridge will slow the
eastward progress of this system as the main upper level energy
continues to move quickly northward. As a result, only low end
rain chances are expected Thursday night into Friday as this front
eventually dissipates across the region.
As was much the case in the near term period, the short term
period will have unseasonably warm temperatures with highs in the
low to mid 70s in the western areas (due to more cloud cover) and
in the upper 70s to near 80 in the east. Overnight lows will be
muggy by January standards, generally in the upper 50s to lower 60s.
&&
.LONG TERM [Friday Night through Tuesday]...
There is good agreement between the GFS and ECMWF that deep layer
ridging will be the dominant synoptic feature over the Southeast.
This correlates to a continuation of above-average temperatures (at
least 10 to 15 degrees warmer than climatology) away from the
beaches (where SSTs remain in the upper 50s to lower 60s). The PoP
will be in the 10 to 30% range- highest along and left of a line
from Albany to Panama City as that region will be closer to the Q-G
forcing and deep layer moisture associated with a persistent
quasi-stationary frontal system.
&&
.AVIATION [through 12z Thursday]...
Updated at 626 am EST-
KVLD is the only site expected to have IFR Vis this morning.
Otherwise, IFR to low-end MVFR cigs will persist across our area
until early afternoon. Most cigs will lift to MVFR mid to late
afternoon, but IFR cigs may persist all day at KECP. Widespread LIFR
(or worse) Vis & cigs are likely tonight, beginning near the coast
shortly after sunset, then spreading inland later tonight. Our
forecast is a blend of the GFS/NAM MOS and latest HRRR, with
emphasis on the HRRR (which has verified well so far this morning)
through this afternoon.
&&
.MARINE...
The pressure gradient will remain tight across the marine area as
a low pressure area lifts northward across Texas. Cautionary level
winds will continue possibly into Thursday before relaxing. Lighter
onshore flow is expected by the weekend as high pressure builds
just off the Florida Peninsula.
&&
.FIRE WEATHER...
Relative humidity levels will remain too moist for red flag
conditions for at least the remainder of this week.
&&
.HYDROLOGY...
No appreciable rainfall amounts are expected through the next few
days.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 75 61 77 59 74 / 10 10 10 20 20
Panama City 71 64 74 63 73 / 20 10 10 40 20
Dothan 71 61 75 62 75 / 20 10 10 30 20
Albany 72 60 75 62 75 / 10 10 10 20 20
Valdosta 76 61 78 60 78 / 10 10 10 10 20
Cross City 79 59 79 58 76 / 10 10 10 10 20
Apalachicola 69 64 70 63 70 / 10 10 10 30 20
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
GM...None.
&&
$$
NEAR TERM...Godsey
SHORT TERM...Godsey
LONG TERM...Fournier
AVIATION...Fournier
MARINE...Godsey
FIRE WEATHER...Fournier
HYDROLOGY...Godsey
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
649 AM EST WED JAN 9 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 526 AM EST WED JAN 9 2013
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A CONTINUED PROGRESSIVE
NRN STREAM ACROSS THE NRN CONUS/SRN CANADA. SHORTWAVE TROF IS
CURRENTLY MOVING OVER THE WRN GREAT LAKES. AT THE SFC...ASSOCIATED
LOW PRES IS OVER NRN ONTARIO. DESPITE RATHER VIGOROUS LOOK OF
SHORTWAVE...VERY LITTLE PCPN HAS OCCURRED OVER THE FCST AREA
OVERNIGHT. SOME PCPN PROBABLY OCCURRED OVER LAKE SUPERIOR PER RADAR
IMAGERY. OVER UPPER MI...NARROW BAND OF PCPN APPEARED TO DEVELOP
OVER THE ERN FCST AREA BTWN 07-09Z...BUT ONLY OB TO REPORT ANY PCPN
WAS AT KERY AND THAT WAS -RA.
FOCUS TODAY SHIFTS TO WINDS AND -SHSN CHANCES IN THE WAKE OF
SHORTWAVE. WEST WINDS WILL BE INCREASING ACROSS THE KEWEENAW OVER
THE NEXT SEVERAL HRS AS CAA INCREASES INSTABILITY/BUILDS MIXING
DEPTH TOWARD THE 45-50KT LOW-LEVEL WIND MAX AT 2-4KFT. COMBINED WITH
IDEAL WNW WIND DIRECTION FOR STRONG WINDS MAKES WIND ADVY ON THE
KEWEENAW AN OBVIOUS CALL. EXPECT STRONGEST WINDS TO OCCUR MID
MORNING INTO EARLY AFTN JUST AHEAD OF APPROACHING AREA OF 5MB/3HR
PRES RISES WHICH IS NOW OVER NE ND/FAR NW MN. GUSTS OF 45-50MPH
APPEAR LIKELY DURING THAT TIME. FARTHER S...WINDS ALONG THE SHORE
TOWARD ONTONAGON/SILVER CITY WILL BE CLOSE TO 45MPH. TO THE E...
SHORELINE LOCATIONS FROM PICTURED ROCKS EASTWARD WILL ALSO SEE GUSTS
TO AROUND 45 MPH. W WINDS SHOULD KEEP THESE HIGHER GUSTS CONFINED
MOSTLY TO THE BEACHES/SHORELINE. ELSEWHERE...IT WILL BE A BREEZY DAY
WITH WIND GUSTS GENERALLY IN THE 25 TO 35 MPH RANGE.
AS FOR PCPN...850MB TEMPS FALLING BRIEFLY TO AROUND -10C WILL BE
MARGINAL FOR LES OFF LAKE SUPERIOR. HOWEVER...SINCE THERE IS A SMALL
AREA OF -SN MOVING ACROSS NRN MN ATTM...EXPECT SOME -SHSN ON THE
KEWEENAW FOR A PORTION OF THE MORNING INTO EARLY AFTN...AND OVER THE
FAR NE FCST AREA DURING THE AFTN. A COUPLE OF OBS IN NRN MN HAVE
DROPPED TO AROUND 1SM...SO THERE CERTAINLY COULD BE A BRIEF PERIOD
OF HEAVIER SHSN. WILL BE SOMETHING TO MONITOR. RIGHT NOW...IT
APPEARS SNOW ACCUMULATIONS WILL BE UNDER AN INCH.
ALTHOUGH THERE WILL BE A TREND TOWARD CLEARING SKIES AWAY FROM THE
KEWEENAW AND FAR NE FCST AREA...CAA THRU MID DAY WILL LIMIT TEMP
RISE. MAX TEMPS SHOULDN`T BE TOO MUCH HIGHER THAN CURRENT READINGS.
30S WILL BE THE RULE.
SFC HIGH PRES RIDGE QUICKLY SHIFTS ACROSS UPPER MI TONIGHT. WITH
SKIES TRENDING TOWARD MAINLY CLEAR...THERE WILL BE A WINDOW FOR
TEMPS TO FALL SHARPLY UNDER A BRIEF PERIOD OF LIGHT/CALM WIND BEFORE
RETURN FLOW DEVELOPS. INDICATED MINS AS LOW AS THE LOW TEENS IN SOME
OF THE TRADITIONAL COLD SPOTS...BUT WOULDN`T BE SURPRISED TO SEE A
FEW SPOTS FALL INTO THE SINGLE DIGITS.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 526 AM EST WED JAN 9 2013
A CONTINUED ACTIVE PATTERN WILL BE THE RULE THROUGH THE WEEKEND AS
MULTIPLE TROUGHS ARE PROGGED TO CROSS THE UPPER GREAT
LAKES...BRINGING WELL ABOVE NORMAL TEMPERATURES AND APPRECIABLE RAIN
FOR THE EAST HALF OF THE CWA.
THURSDAY AND THURSDAY NIGHT...THE UPPER GREAT LAKES AND MIDWEST WILL
BE UNDER THE INFLUENCE OF A PRONOUNCED MID-LEVEL TROUGH. THE LAYER
SHOULD BE FAIRLY DRY AND ALLOW FOR ABUNDANT SUNSHINE ACROSS THE CWA.
MEANWHILE...SOUTHERLY RETURN FLOW AHEAD OF AN APPROACHING
MID-LEVEL/SFC LOW OVER THE MID-MS VALLEY WILL BRING INCREASING WINDS
AND THIN...HIGH CIRRUS CLOUDS IN THE AFTERNOON. EXPECTATION IS THAT
MOSTLY SUNNY SKIES AND THE LOWER ALBEDO OF THE DENSE UPPER MI
FORESTS WILL RESULT IN TEMPS WELL-ABOVE NORMAL...AND EVEN SLIGHTLY
ABOVE CURRENT GUIDANCE. KEPT FORECAST VERY SIMILAR TO PREVIOUS
SHIFT...WITH UPPER 30S ACROSS MUCH OF THE INTERIOR AND LOW 40S FOR
DOWNSLOPE LOCATIONS ALONG LAKE SUPERIOR. SOME LOCATIONS WILL
APPROACH RECORD HIGHS IF DOWNSLOPE INFLUENCE IS STRONGER THAN
ANTICIPATED.
NOW ONTO THE SYSTEM TAKING AIM ON THE AREA THURSDAY NIGHT. A COMPACT
MID-LEVEL CUTOFF LOW NEAR THE GREAT BEND OF TEXAS IS BEGINNING ITS
TURN NORTHEASTWARD AND IS SET TO REACH THE MID-MS VALLEY BY LATE
THURSDAY NIGHT. MODEL AGREEMENT ON THIS SYSTEM HAS BECOME VERY GOOD
WITH THE EXCEPTION OF THE GFS...WHICH HAS BEEN TRENDING SLOWER. WILL
STICK WITH THE MORE CONSISTENT ECMWF/GEM SOLUTION.
THOUGH THE MAIN MID-LEVEL FORCING WITH THE SHORTWAVE WILL PASS JUST
TO THE SOUTHEAST OF THE CWA...DECENT ISENTROPIC LIFT ON THE 295-305K
SURFACES AND CONSIDERABLE LOW-LEVEL MOISTURE TRANSPORT ON THE NOSE
OF A 60KT H8 JET WILL SUPPORT MODERATE RAIN OVER THE EAST HALF OF
THE CWA. MOISTURE CONTENT OF THE COLUMN WILL BE AN IMPRESSIVE
1.1"/450 PERCENT OF NORMAL. GIVEN THE SET-UP AND HIGH WATER CONTENT
FOR JANUARY...HAVE CONTINUED THE TREND OF BUMPING UP POPS TO
WIDESPREAD RAIN ACROSS THE EASTERN TWO-THIRDS OF THE CWA BEGINNING
LATE THURSDAY EVENING. HELD OFF POPS FOR ALL BUT THE SOUTH-CENTRAL
CWA UNTIL THIS TIME. STORM TOTAL QPF OF A HALF INCH OR MORE FOR THE
EAST HALF SEEMS REASONABLE ATTM.
AS FOR PRECIP TYPE...TEMPERATURES ACROSS THE INTERIOR WEST AND
CENTRAL MAY FALL BELOW FREEZING IN THE EVENING BEFORE THICKER CLOUDS
AND WAA TAKE CONTROL AND WARM TEMPS BACK ABOVE FREEZING. INITIAL
RAIN WILL BE FALLING INTO QUITE A DRY LAYER...WITH SFC WET-BULB
TEMPS JUST UNDER FREEZING. HOWEVER...GIVEN WARM HIGHS AND
CONSIDERABLE SUNSHINE THURSDAY...A NARROW WINDOW OF BELOW FREEING
TEMPS...AND WARM RAIN FROM A 6 TO 8C WARM LAYER ABOVE THE SFC...ONLY
PUT IN A SLIGHT CHANCE OF FREEZING RAIN MAINLY INTERIOR CENTRAL. NOT
REALLY EXPECTING ANY ICING...BUT DID WANT TO PUT A SMALL MENTION IN
THERE.
FRIDAY THROUGH FRIDAY NIGHT...PRECIP WILL CONTINUE ACROSS THE EAST
HALF FRIDAY MORNING AS THE INFLUX OF MOISTURE CONTINUES OVER THE
AREA. A SECONDARY DEEP TROUGH MOVING INTO THE ROCKIES FRIDAY
AFTERNOON WILL BEGIN TO LIFT NORTHEASTWARD BY FRIDAY EVENING. IN
COMBINATION WITH THE LEFT EXIT OF A 140KT UPPER JET OVER THE
UPPER-MS VALLEY...A SFC LOW WILL QUICKLY FORM OVER MN FRIDAY NIGHT.
THERE SHOULD BE A LAPSE IN PRECIP FOR ALL BUT THE WESTERN CWA FRIDAY
NIGHT AS PLENTY OF DRY AIR IS DRAWN INTO THE REGION AHEAD OF THE
TROUGH/SFC LOW. SOME DRIZZLE IS POSSIBLE WITHIN A THICK LOW-LEVEL
STRATUS DECK WHERE RAIN SHOWERS MAY NOT BE AS PREVALENT CENTRAL AND
EAST. ALSO HAVE AREAS OF FOG IN THE FORECAST GIVEN RELATIVELY
WARM/MOIST AIR FLOWING OVER MELTING SNOW.
SATURDAY...AS THE SURFACE LOW TRACKS OVER LAKE SUPERIOR LATE FRIDAY
NIGHT INTO SATURDAY...IT WILL DRAW DOWN COLDER AIR FROM CANADA AND
SWEEP A COLD FRONT ACROSS THE CWA. HIGHS WILL LIKELY BE EARLY IN THE
DAY AS TEMPERATURES WILL QUICKLY FALL AT MOST LOCATIONS BY THE
AFTERNOON. EXPECT ANY RAIN SHOWERS TO TRANSITION TO SNOW SHOWERS
FROM WEST TO EAST THROUGHOUT THE DAY. ONLY MINOR ACCUMULATIONS ARE
EXPECTED AS MID/UPPER LEVEL SUPPORT WILL BE NORTH OF THE CWA AND
DECENT H5 Q-VECTOR DIVERGENCE WILL BE PASSING OVER THE CWA.
SATURDAY NIGHT THROUGH TUESDAY...DID NOT MAKE MANY CHANGES PAST THIS
POINT. LAKE EFFECT SNOW LOOKS LIKELY FOR THE KEWEENAW AND FAR
NORTHEAST SATURDAY NIGHT THROUGH SUNDAY WITH WNW WINDS. A CORE OF
-17 TO -19C AIR GETS WRAPPED AROUND THE DEPARTING LOW AND CROSSES
LAKE SUPERIOR SATURDAY NIGHT. INVERSION HEIGHTS SHOULD STAY BETWEEN
4-5 KFT THROUGH MUCH OF SUNDAY UNDERNEATH SUBSIDENCE BEHIND THE
DEPARTING TROUGH. THOSE HEIGHTS THEN FALL UNDER 3 KFT AND DRY AIR
ADVECTS INTO THE REGION FROM THE SW SUNDAY NIGHT...THEREBY
DECREASING LES COVERAGE BY MONDAY. TEMPERATURES THEN REMAIN AROUND
SEASONAL NORMS TO START NEXT WEEK WITH MINIMAL PRECIP CHANCES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 644 AM EST WED JAN 9 2013
COLD FRONT MOVING ACROSS UPPER MI WILL USHER IN STRONG/GUSTY W WINDS
TODAY. AT THE MORE EXPOSED KCMX LOCATION...WINDS WILL BE
STRONGEST...GUSTING TO AROUND 40KT FROM MID MORNING THRU EARLY AFTN.
AT KIWD/KSAW...WINDS SHOULD GUST TO AROUND 30KT. WINDS WILL QUICKLY
DIMINISH W TO E LATE AFTN/EVENING AS HIGH PRES RIDGE ARRIVES.
PER RADAR TRENDS/SFC OBS UPSTREAM...EXPECT A PERIOD OF IFR
CONDITIONS WITH -SHSN MID TO LATE MORNING AT KCMX. COULD SEE BRIEF
LIFR CONDITIONS. -SHSN SHOULD BE SHORT LIVED AS DRIER AIR ARRIVES
THIS AFTN. MVFR CIGS WILL PROBABLY PREVAIL AT KCMX DURING THE
AFTN...THEN SCATTER OUT TONIGHT AS WINDS BACK SRLY WITH PASSAGE OF
SFC HIGH PRES RIDGE. MAY SEE A PERIOD OF MVFR CIGS AT KIWD MID
MORNING THRU EARLY AFTN. AT KSAW...EXPECT DOWNSLOPING WESTERLY WINDS
TO RESULT IN VFR CONDITIONS THRU THE PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 526 AM EST WED JAN 9 2013
IN THE WAKE OF COLD FRONT PASSING ACROSS LAKE SUPERIOR THIS
MORNING...EXPECT W GALES OF 35-45KT TODAY. HIGH OBS PLATFORMS MAY
HAVE A COUPLE OF HRS OF GUSTS TO STORM FORCE JUST AHEAD OF 5MB/3HR
PRES RISES THAT WILL SHIFT ACROSS THE AREA TODAY. WINDS WILL QUICKLY
DIMINISH TO UNDER 20KT W TO E TONIGHT AS SFC HIGH PRES RIDGE MOVES
ACROSS LAKE SUPERIOR. INCREASING SOUTHERLY WINDS TO 20 TO 30 KNOTS
AHEAD OF AN APPROACHING LOW PRESSURE IN THE MID-MISSISSIPPI VALLEY
WILL AFFECT MAINLY THE EAST HALF OF LAKE SUPERIOR THURSDAY AND
THURSDAY NIGHT. LIGHT SOUTHERLY WINDS WILL THEN TAKE HOLD FRIDAY
BEFORE A COLD FRONT SWEEPS ACROSS THE LAKE FROM WEST TO EAST ON
SATURDAY. WESTERLY WINDS OF 25 TO 30 KNOTS WILL DEVELOP BY SATURDAY
AFTERNOON AND CONTINUE INTO EARLY SATURDAY EVENING. A FEW GALES TO 35
KNOTS WILL BE POSSIBLE ACROSS THE EAST HALF OF THE LAKE LATE SATURDAY
AFTERNOON. THE PATTERN BECOMES QUITE BENIGN BY SUNDAY...WITH MAINLY
WESTERLY WINDS UNDER 20 KNOTS THROUGH THE REMAINDER OF THE PERIOD.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR MIZ001-003.
LAKE SUPERIOR...
GALE WARNING UNTIL 10 PM EST THIS EVENING FOR LSZ249>251-266-267.
GALE WARNING UNTIL 7 PM EST THIS EVENING FOR LSZ243>248-264-265.
GALE WARNING UNTIL 4 PM EST /3 PM CST/ THIS AFTERNOON FOR LSZ162-
240>242-263.
LAKE MICHIGAN...
GALE WARNING UNTIL 4 PM EST THIS AFTERNOON FOR LMZ248-250.
GALE WARNING UNTIL 1 PM EST THIS AFTERNOON FOR LMZ221.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...TK
AVIATION...ROLFSON
MARINE...ROLFSON/TK
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
529 AM EST WED JAN 9 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 526 AM EST WED JAN 9 2013
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A CONTINUED PROGRESSIVE
NRN STREAM ACROSS THE NRN CONUS/SRN CANADA. SHORTWAVE TROF IS
CURRENTLY MOVING OVER THE WRN GREAT LAKES. AT THE SFC...ASSOCIATED
LOW PRES IS OVER NRN ONTARIO. DESPITE RATHER VIGOROUS LOOK OF
SHORTWAVE...VERY LITTLE PCPN HAS OCCURRED OVER THE FCST AREA
OVERNIGHT. SOME PCPN PROBABLY OCCURRED OVER LAKE SUPERIOR PER RADAR
IMAGERY. OVER UPPER MI...NARROW BAND OF PCPN APPEARED TO DEVELOP
OVER THE ERN FCST AREA BTWN 07-09Z...BUT ONLY OB TO REPORT ANY PCPN
WAS AT KERY AND THAT WAS -RA.
FOCUS TODAY SHIFTS TO WINDS AND -SHSN CHANCES IN THE WAKE OF
SHORTWAVE. WEST WINDS WILL BE INCREASING ACROSS THE KEWEENAW OVER
THE NEXT SEVERAL HRS AS CAA INCREASES INSTABILITY/BUILDS MIXING
DEPTH TOWARD THE 45-50KT LOW-LEVEL WIND MAX AT 2-4KFT. COMBINED WITH
IDEAL WNW WIND DIRECTION FOR STRONG WINDS MAKES WIND ADVY ON THE
KEWEENAW AN OBVIOUS CALL. EXPECT STRONGEST WINDS TO OCCUR MID
MORNING INTO EARLY AFTN JUST AHEAD OF APPROACHING AREA OF 5MB/3HR
PRES RISES WHICH IS NOW OVER NE ND/FAR NW MN. GUSTS OF 45-50MPH
APPEAR LIKELY DURING THAT TIME. FARTHER S...WINDS ALONG THE SHORE
TOWARD ONTONAGON/SILVER CITY WILL BE CLOSE TO 45MPH. TO THE E...
SHORELINE LOCATIONS FROM PICTURED ROCKS EASTWARD WILL ALSO SEE GUSTS
TO AROUND 45 MPH. W WINDS SHOULD KEEP THESE HIGHER GUSTS CONFINED
MOSTLY TO THE BEACHES/SHORELINE. ELSEWHERE...IT WILL BE A BREEZY DAY
WITH WIND GUSTS GENERALLY IN THE 25 TO 35 MPH RANGE.
AS FOR PCPN...850MB TEMPS FALLING BRIEFLY TO AROUND -10C WILL BE
MARGINAL FOR LES OFF LAKE SUPERIOR. HOWEVER...SINCE THERE IS A SMALL
AREA OF -SN MOVING ACROSS NRN MN ATTM...EXPECT SOME -SHSN ON THE
KEWEENAW FOR A PORTION OF THE MORNING INTO EARLY AFTN...AND OVER THE
FAR NE FCST AREA DURING THE AFTN. A COUPLE OF OBS IN NRN MN HAVE
DROPPED TO AROUND 1SM...SO THERE CERTAINLY COULD BE A BRIEF PERIOD
OF HEAVIER SHSN. WILL BE SOMETHING TO MONITOR. RIGHT NOW...IT
APPEARS SNOW ACCUMULATIONS WILL BE UNDER AN INCH.
ALTHOUGH THERE WILL BE A TREND TOWARD CLEARING SKIES AWAY FROM THE
KEWEENAW AND FAR NE FCST AREA...CAA THRU MID DAY WILL LIMIT TEMP
RISE. MAX TEMPS SHOULDN`T BE TOO MUCH HIGHER THAN CURRENT READINGS.
30S WILL BE THE RULE.
SFC HIGH PRES RIDGE QUICKLY SHIFTS ACROSS UPPER MI TONIGHT. WITH
SKIES TRENDING TOWARD MAINLY CLEAR...THERE WILL BE A WINDOW FOR
TEMPS TO FALL SHARPLY UNDER A BRIEF PERIOD OF LIGHT/CALM WIND BEFORE
RETURN FLOW DEVELOPS. INDICATED MINS AS LOW AS THE LOW TEENS IN SOME
OF THE TRADITIONAL COLD SPOTS...BUT WOULDN`T BE SURPRISED TO SEE A
FEW SPOTS FALL INTO THE SINGLE DIGITS.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 526 AM EST WED JAN 9 2013
A CONTINUED ACTIVE PATTERN WILL BE THE RULE THROUGH THE WEEKEND AS
MULTIPLE TROUGHS ARE PROGGED TO CROSS THE UPPER GREAT
LAKES...BRINGING WELL ABOVE NORMAL TEMPERATURES AND APPRECIABLE RAIN
FOR THE EAST HALF OF THE CWA.
THURSDAY AND THURSDAY NIGHT...THE UPPER GREAT LAKES AND MIDWEST WILL
BE UNDER THE INFLUENCE OF A PRONOUNCED MID-LEVEL TROUGH. THE LAYER
SHOULD BE FAIRLY DRY AND ALLOW FOR ABUNDANT SUNSHINE ACROSS THE CWA.
MEANWHILE...SOUTHERLY RETURN FLOW AHEAD OF AN APPROACHING
MID-LEVEL/SFC LOW OVER THE MID-MS VALLEY WILL BRING INCREASING WINDS
AND THIN...HIGH CIRRUS CLOUDS IN THE AFTERNOON. EXPECTATION IS THAT
MOSTLY SUNNY SKIES AND THE LOWER ALBEDO OF THE DENSE UPPER MI
FORESTS WILL RESULT IN TEMPS WELL-ABOVE NORMAL...AND EVEN SLIGHTLY
ABOVE CURRENT GUIDANCE. KEPT FORECAST VERY SIMILAR TO PREVIOUS
SHIFT...WITH UPPER 30S ACROSS MUCH OF THE INTERIOR AND LOW 40S FOR
DOWNSLOPE LOCATIONS ALONG LAKE SUPERIOR. SOME LOCATIONS WILL
APPROACH RECORD HIGHS IF DOWNSLOPE INFLUENCE IS STRONGER THAN
ANTICIPATED.
NOW ONTO THE SYSTEM TAKING AIM ON THE AREA THURSDAY NIGHT. A COMPACT
MID-LEVEL CUTOFF LOW NEAR THE GREAT BEND OF TEXAS IS BEGINNING ITS
TURN NORTHEASTWARD AND IS SET TO REACH THE MID-MS VALLEY BY LATE
THURSDAY NIGHT. MODEL AGREEMENT ON THIS SYSTEM HAS BECOME VERY GOOD
WITH THE EXCEPTION OF THE GFS...WHICH HAS BEEN TRENDING SLOWER. WILL
STICK WITH THE MORE CONSISTENT ECMWF/GEM SOLUTION.
THOUGH THE MAIN MID-LEVEL FORCING WITH THE SHORTWAVE WILL PASS JUST
TO THE SOUTHEAST OF THE CWA...DECENT ISENTROPIC LIFT ON THE 295-305K
SURFACES AND CONSIDERABLE LOW-LEVEL MOISTURE TRANSPORT ON THE NOSE
OF A 60KT H8 JET WILL SUPPORT MODERATE RAIN OVER THE EAST HALF OF
THE CWA. MOISTURE CONTENT OF THE COLUMN WILL BE AN IMPRESSIVE
1.1"/450 PERCENT OF NORMAL. GIVEN THE SET-UP AND HIGH WATER CONTENT
FOR JANUARY...HAVE CONTINUED THE TREND OF BUMPING UP POPS TO
WIDESPREAD RAIN ACROSS THE EASTERN TWO-THIRDS OF THE CWA BEGINNING
LATE THURSDAY EVENING. HELD OFF POPS FOR ALL BUT THE SOUTH-CENTRAL
CWA UNTIL THIS TIME. STORM TOTAL QPF OF A HALF INCH OR MORE FOR THE
EAST HALF SEEMS REASONABLE ATTM.
AS FOR PRECIP TYPE...TEMPERATURES ACROSS THE INTERIOR WEST AND
CENTRAL MAY FALL BELOW FREEZING IN THE EVENING BEFORE THICKER CLOUDS
AND WAA TAKE CONTROL AND WARM TEMPS BACK ABOVE FREEZING. INITIAL
RAIN WILL BE FALLING INTO QUITE A DRY LAYER...WITH SFC WET-BULB
TEMPS JUST UNDER FREEZING. HOWEVER...GIVEN WARM HIGHS AND
CONSIDERABLE SUNSHINE THURSDAY...A NARROW WINDOW OF BELOW FREEING
TEMPS...AND WARM RAIN FROM A 6 TO 8C WARM LAYER ABOVE THE SFC...ONLY
PUT IN A SLIGHT CHANCE OF FREEZING RAIN MAINLY INTERIOR CENTRAL. NOT
REALLY EXPECTING ANY ICING...BUT DID WANT TO PUT A SMALL MENTION IN
THERE.
FRIDAY THROUGH FRIDAY NIGHT...PRECIP WILL CONTINUE ACROSS THE EAST
HALF FRIDAY MORNING AS THE INFLUX OF MOISTURE CONTINUES OVER THE
AREA. A SECONDARY DEEP TROUGH MOVING INTO THE ROCKIES FRIDAY
AFTERNOON WILL BEGIN TO LIFT NORTHEASTWARD BY FRIDAY EVENING. IN
COMBINATION WITH THE LEFT EXIT OF A 140KT UPPER JET OVER THE
UPPER-MS VALLEY...A SFC LOW WILL QUICKLY FORM OVER MN FRIDAY NIGHT.
THERE SHOULD BE A LAPSE IN PRECIP FOR ALL BUT THE WESTERN CWA FRIDAY
NIGHT AS PLENTY OF DRY AIR IS DRAWN INTO THE REGION AHEAD OF THE
TROUGH/SFC LOW. SOME DRIZZLE IS POSSIBLE WITHIN A THICK LOW-LEVEL
STRATUS DECK WHERE RAIN SHOWERS MAY NOT BE AS PREVALENT CENTRAL AND
EAST. ALSO HAVE AREAS OF FOG IN THE FORECAST GIVEN RELATIVELY
WARM/MOIST AIR FLOWING OVER MELTING SNOW.
SATURDAY...AS THE SURFACE LOW TRACKS OVER LAKE SUPERIOR LATE FRIDAY
NIGHT INTO SATURDAY...IT WILL DRAW DOWN COLDER AIR FROM CANADA AND
SWEEP A COLD FRONT ACROSS THE CWA. HIGHS WILL LIKELY BE EARLY IN THE
DAY AS TEMPERATURES WILL QUICKLY FALL AT MOST LOCATIONS BY THE
AFTERNOON. EXPECT ANY RAIN SHOWERS TO TRANSITION TO SNOW SHOWERS
FROM WEST TO EAST THROUGHOUT THE DAY. ONLY MINOR ACCUMULATIONS ARE
EXPECTED AS MID/UPPER LEVEL SUPPORT WILL BE NORTH OF THE CWA AND
DECENT H5 Q-VECTOR DIVERGENCE WILL BE PASSING OVER THE CWA.
SATURDAY NIGHT THROUGH TUESDAY...DID NOT MAKE MANY CHANGES PAST THIS
POINT. LAKE EFFECT SNOW LOOKS LIKELY FOR THE KEWEENAW AND FAR
NORTHEAST SATURDAY NIGHT THROUGH SUNDAY WITH WNW WINDS. A CORE OF
-17 TO -19C AIR GETS WRAPPED AROUND THE DEPARTING LOW AND CROSSES
LAKE SUPERIOR SATURDAY NIGHT. INVERSION HEIGHTS SHOULD STAY BETWEEN
4-5 KFT THROUGH MUCH OF SUNDAY UNDERNEATH SUBSIDENCE BEHIND THE
DEPARTING TROUGH. THOSE HEIGHTS THEN FALL UNDER 3 KFT AND DRY AIR
ADVECTS INTO THE REGION FROM THE SW SUNDAY NIGHT...THEREBY
DECREASING LES COVERAGE BY MONDAY. TEMPERATURES THEN REMAIN AROUND
SEASONAL NORMS TO START NEXT WEEK WITH MINIMAL PRECIP CHANCES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 526 AM EST WED JAN 9 2013
SOUTHERLY WINDS AHEAD OF A FRONTAL SYSTEM HAS BROUGHT LOW CLOUDS
ACROSS UPPER MICHIGAN THIS EVENING. EXPECT THE MVFR CLOUDS TO
PERSIST UNTIL MIDDAY WHEN DRIER AIR WILL MOVE IN FROM THE WEST.
EXPECT GUSTY WESTERLY WINDS LATE IN THE NIGHT INTO TODAY BEHIND THE
FRONT. DECENT COLD AIR MOVING OVER LAKE SUPERIOR WILL SUPPORT GUSTS
TO 40KTS AT KCMX AROUND DAYBREAK AND CONTINUING FOR MUCH OF THE
MORNING. AT THE OTHER TWO SITES...WINDS WILL BE GUSTY AND IN THE
20-30KT RANGE. WINDS WILL DIMINISH TOWARD EVENING AS A RIDGE BUILDS
FROM THE UPPER MISSISSIPPI VALLEY INTO THE WESTERN GREAT LAKES.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 526 AM EST WED JAN 9 2013
IN THE WAKE OF COLD FRONT PASSING ACROSS LAKE SUPERIOR THIS
MORNING...EXPECT W GALES OF 35-45KT TODAY. HIGH OBS PLATFORMS MAY
HAVE A COUPLE OF HRS OF GUSTS TO STORM FORCE JUST AHEAD OF 5MB/3HR
PRES RISES THAT WILL SHIFT ACROSS THE AREA TODAY. WINDS WILL QUICKLY
DIMINISH TO UNDER 20KT W TO E TONIGHT AS SFC HIGH PRES RIDGE MOVES
ACROSS LAKE SUPERIOR. INCREASING SOUTHERLY WINDS TO 20 TO 30 KNOTS
AHEAD OF AN APPROACHING LOW PRESSURE IN THE MID-MISSISSIPPI VALLEY
WILL AFFECT MAINLY THE EAST HALF OF LAKE SUPERIOR THURSDAY AND
THURSDAY NIGHT. LIGHT SOUTHERLY WINDS WILL THEN TAKE HOLD FRIDAY
BEFORE A COLD FRONT SWEEPS ACROSS THE LAKE FROM WEST TO EAST ON
SATURDAY. WESTERLY WINDS OF 25 TO 30 KNOTS WILL DEVELOP BY SATURDAY
AFTERNOON AND CONTINUE INTO EARLY SATURDAY EVENING. A FEW GALES TO 35
KNOTS WILL BE POSSIBLE ACROSS THE EAST HALF OF THE LAKE LATE SATURDAY
AFTERNOON. THE PATTERN BECOMES QUITE BENIGN BY SUNDAY...WITH MAINLY
WESTERLY WINDS UNDER 20 KNOTS THROUGH THE REMAINDER OF THE PERIOD. &&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR MIZ001-003.
LAKE SUPERIOR...
GALE WARNING UNTIL 10 PM EST THIS EVENING FOR LSZ249>251-266-267.
GALE WARNING UNTIL 7 PM EST THIS EVENING FOR LSZ243>248-264-265.
GALE WARNING UNTIL 4 PM EST /3 PM CST/ THIS AFTERNOON FOR LSZ162-
240>242-263.
LAKE MICHIGAN...
GALE WARNING UNTIL 4 PM EST THIS AFTERNOON FOR LMZ248-250.
GALE WARNING UNTIL 1 PM EST THIS AFTERNOON FOR LMZ221.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...TK
AVIATION...JLB
MARINE...ROLFSON/TK
AREA FORECAST DISCUSSION...UPDATED
NWS TWIN CITIES/CHANHASSEN MN
614 AM CST WED JAN 9 2013
.UPDATE...UPDATED FOR AVIATION DISCUSSION BELOW.
&&
.PREV DISCUSSION.../ISSUED 437 AM CST WED JAN 9 2013/
MAIN FORECAST CONCERN FOR THIS PERIOD WAS IN THE THURSDAY THROUGH
SATURDAY TIME FRAME AS AN UNCHARACTERISTICALLY WARM AND MOIST
SYSTEM FOR JANUARY STANDARDS IMPACTS THE AREA...WITH WHAT LOOKS
TO BE PRIMARILY RAIN THURSDAY THROUGH FRIDAY...WITH A TRANSITION
BACK TO SNOW FRIDAY EVENING.
VERY MILD CONDITIONS TO START THE DAY...WITH MANY AREAS STILL IN
THE 30S AT 3AM AS THE AREA SITS OUT AHEAD OF PACIFIC COLD FRONT
CURRENTLY MOVING ACROSS THE DAKOTAS. CURRENT HIGHS FOR TODAY ONLY 5
TO 10 DEGS HIGHER THAN CURRENT TEMPS...SO COULD END UP BEING A BIT
WARMER THAN CURRENTLY FORECAST...ESPECIALLY EAST OF THE BUFFALO
RIDGE IN SW MN...WHERE TEMPS ARE A DEGREE OR TWO ON EITHER SIDE
OF 35 AT THE MOMENT. ALSO GETTING SOME STRONG WINDS IN THE WRN CWA
THIS MORNING...WITH SPEEDS UP NEAR ADVY LEVELS...WITH SOME
SUSTAINED WINDS IN THE AXN/MOX AREA NEAR 30 MPH...WITH GUSTS
APPROACHING 40. FORTUNATELY...NOT EXPECTING THINGS TO GET ANY
WORSE THAN WHAT WE HAVE ALREADY SEEN SINCE MAIN PUSH OF PRESSURE
RISES WILL BE GOING NORTH OF HERE...ALONG WITH A STRONG INVERSION
MAKING IT DIFFICULT TO MIX MUCH WIND TO THE GROUND. THIS SECOND
PART IS FORTUNATE...AS RAP SHOWS 1K FT WINDS UP AT 40 KTS...BUT
THE INVERSION WILL KEEP THOSE UP THERE...MEANING A WIND ADVY IS
UNNECESSARY FOR TODAY.
THE WEATHER LOOKS QUIET TODAY THROUGH TONIGHT...BUT STILL LOOKS
TO TURN SOUTH IN A HURRY THURSDAY AFTERNOON. CUT OFF LOW WITH A
WALL OF WATER OVER TX THIS MORNING WILL SLOWLY DRIFT NORTH TODAY
AS A SHARP THROUGH MOVES ONSHORE OUT WEST. AS THE MAIN TROUGH
WORKS ACROSS THE ROCKIES THURSDAY...IT WILL PICK UP THE CLOSED LOW
A QUICKLY SEND IT AND ITS RAIN NORTH TOWARD THE GREAT LAKES. AS
WITH PREVIOUS FORECAST...FAVORED A GEM/ECMWF BLEND FOR TIMING
PRECIP IN THURSDAY/THURSDAY NIGHT AS THIS IS A GOOD COMPROMISE
BETWEEN THE NAM...WHICH IS ABOUT 6 HOURS FASTER AND THE GFS WHICH
IS 6 HOURS SLOWER THAN THE GEM/ECMWF. HOWEVER...WORRIED NAM MAY BE
RIGHT WITH THE FASTER TIMING. THIS IS BECAUSE A QUICK LOOK AT H85
MOISTURE TRANSPORT ON THE ECMWF SHOWS THAT IT AGREES MUCH MORE
WITH THE TIMING INDICATED BY THE NAM QPF THAN ITS OWN...SO WOULD
NOT BE SURPRISED IF WE NEED TO START SPEEDING UP THE SPREAD OF
POPS NORTH THURSDAY AFTERNOON.
BIG ISSUE WITH PRECIP THURSDAY NIGHT THROUGH FRIDAY IS ALL MODELS
ARE SHOWING THE MPX CWA GETTING DRY SLOTTED...WITH MOISTURE
REMAINING RATHER SHALLOW AFTER THE INITIAL PUSH OF PRECIP THURSDAY
AFTERNOON. DID FAVOR QPF THU/THU NIGHT TOWARD THE HIGHER HPC
NUMBERS AS BOTH THE NAM AND GFS SHOW PWATS WITH THIS INITIAL SURGE
OF PRECIP INCREASE TO AND EVEN EXCEEDING 1 INCH. THIS IS A GOOD
400-500 PERCENT OF NORMAL. THE HIGHEST PWAT EVER OBSERVED AT
MPX/STC IN JANUARY IS 0.92...SO WHAT WE WILL BE SEEING THURSDAY
WILL BE QUITE RARE INDEED. BASED ON THE HIGH PWAT...LIKE THE
HIGHER HPC NUMBERS...THOUGH HEAVIEST RAIN WILL BE DIRECTED MORE
TOWARD GREEN BAY...WHERE BEST LLJ AND MOISTURE TRANSPORT WILL BE
DIRECTED. DRY SLOTTING THURSDAY NIGHT THROUGH FRIDAY RESULTS IN
SOUNDINGS LACKING ANY ICE CRYSTALS...WITH DRIZZLE LOOKING TO BE THE
PRIMARY PRECIP SEEN IN THIS PERIOD.
AS FOR P-TYPE...FAVORED TEMPERATURE FORECAST THU-FRI TOWARD THE
GEM/ECMWF AS WELL...WHICH RESULTS IN A MUCH WARMER SCENARIO. BY
THE TIME PRECIP GETS HERE THURSDAY AFTERNOON...CURRENTLY HAVE THE
ENTIRE CWA ABV FREEZING...SO KEPT PRECIP MENTION THURSDAY AS ONLY
RAIN. FOR THURSDAY NIGHT...MAY BE QUESTIONABLE IF LOWS ANYWHERE IN
THE MPX CWA DROP BELOW FREEZING...WHICH MEANS RAIN WILL LIKELY BE
THE PRIMARY P-TYPE RIGHT THROUGH THURSDAY NIGHT. ON
FRIDAY...MODELS BEGINNING TO REALLY TIGHTEN UP BAROCLINIC ZONE
THAT WILL BE JUST WEST/NW OF THE MPX AREA...WITH WINDS BACKING TO
THE SE. THIS SHOULD ALLOW 40 DEG TEMPERATURES TO SNEAK INTO ERN
AREAS FRIDAY. THIS FRONT DOES NOT LOOK TO START WORKING ACROSS
THE MPX CWA UNTIL FRIDAY NIGHT BASED ON AN ECMWF/GFS/NAM BLEND AS
A RAPIDLY DEEPENING SFC LOW MOVES UP FROM NEAR SIOUX FALLS UP TO
THE ARROWHEAD. NO OTHER WAY TO EXPLAIN THE CAA BEHIND THIS FRONT
FRIDAY NIGHT OTHER THAN AS INTENSE...WITH WIND ADVY STRENGTH WINDS
LOOKING LIKELY AND TEMPERATURES LIKELY DROPPING 20 DEGREES OR MORE
WITHIN AN HOUR OR TWO. THIS WILL QUICKLY TURN ANY PRECIP OVER TO
SNOW...THOUGH TRACK OF THE LOW WILL KEEP PRIMARY BAND OF SNOW
ACROSS NW MN.
LOOKING AT POTENTIAL HEADLINES...THERE WILL BE THE POSSIBILITY FOR
TWO WITH THIS SYSTEM...A WINTER WEATHER AND WIND ADVY. AT THE
MOMENT...THE MOST LIKELY PLACE THAT MAY NEED A WINTER WX ADVY IS
THE FAR NW CWA. THIS IS WHERE THE HIGHEST POTENTIAL FOR SEEING
FZRA WILL BE THURSDAY NIGHT...FOLLOWED BY THE POTENTIAL FOR A FEW
INCHES OF SNOW FRIDAY NIGHT INTO SATURDAY DEPENDING ON HOW FAR SE
THE DEFORMATION PRECIP BAND SETS UP. AS FOR THE WIND ADVY...FRIDAY
NIGHT IS LOOKING QUITE BREEZY...ESPECIALLY ON THE ECMWF...WHICH
DEVELOPS SUSTAINED WINDS IN WRN MN IN EXCESS OF 30 MPH...WITH
GUSTS OVER 40 MPH IN RESPONSE TO IT SENDING A 990 LOW OVER TO THE
WEST END OF LAKE SUPERIOR AS A 1030 MB HIGH MOVES INTO THE BLACK
HILLS.
AS FOR THE REST OF THE FORECAST...IT IS LOOKING COOLER...ESPECIALLY
SATURDAY THROUGH MONDAY...WHEN BELOW ZERO LOWS WILL RETURN WITH
HIGHS IN THE SINGLE DIGITS AND TEENS...THOUGH WE COULD GET WARMER
THAN THAT AS WARM TEMPS THURSDAY/FRIDAY WILL LIKELY PUNCH A LOT OF
HOLES IN THE SNOWPACK OUTSIDE OF THE NW CWA...WHICH WILL LIKELY
GET SOME SNOW FRIDAY NIGHT. BY THE MIDDLE OF THE WEEK...BOTH THE
GFS/ECMWF SHOW TEMPERATURES MODERATING OUT AHEAD OF CLIPPER COMING
DOWN TUESDAY NIGHT/WEDNESDAY. ALSO INTERESTING IS THAT AS NEXT
WEEK GROWS CLOSER...THE GFS/ECMWF CONTINUE TO BACK OFF ON THE
EXTENT TO WHICH THE ARCTIC AIR MAKES IN INTO THE US...WITH EACH
NEW RUN SEEMING TO KEEP IT FURTHER AND FURTHER NORTH...SO THAT WILL
BE SOMETHING TO WATCH. AS FOR WEATHER...AFTER THURSDAY NIGHT
THROUGH SATURDAY IT LOOKS DRY.
&&
.AVIATION.../12Z TAF ISSUANCE/
MAIN FORECAST CONCERN FOR THIS ISSUANCE IS WIND...WITH VFR
CONDITIONS EXPECTED FOR THE NEXT 24 TO 30 HOURS. GUSTY WEST WINDS
WILL SUBSIDE LATER THIS MORNING AND BACK SOUTHERLY BY EVENING. AS
A NEW STORM SYSTEM DEVELOPS TO THE WEST...WINDS WILL STRENGTHEN
AGAIN OVERNIGHT...ESPECIALLY ACROSS WRN MN WHERE SOME GUSTS MAY
EXCEED 25 KTS. IN ADDITION...A STRONG LOW LEVEL JET OF 50 TO 55
KTS IS EXPECTED TO DEVELOP AROUND 1000 FT AFTER 06Z WHICH HAS LED
TO THE INCLUSION OF WIND SHEAR MENTION AT AXN...RWF...AND STC.
KMSP...VFR CONDITIONS THROUGH 18Z THURSDAY WITH SKC. RAPIDLY
DETERIORATING CONDITIONS EXPECTED JUST AFTER THE CURRENT PERIOD
WITH TREMENDOUS AMOUNTS OF INCOMING MOISTURE. MVFR OR LOWER
CONDITIONS LIKELY BY LATE THURSDAY AFTERNOON. GUSTY WEST WINDS
WILL SUBSIDE LATER THIS MORNING AND BACK SOUTH BY EVENING. COULD
SEE WINDS APPROACH 50 KTS AT 1000FT LATE TONIGHT...BUT DECIDED
AGAINST INCLUDING WIND SHEAR WITH THIS ISSUANCE GIVEN MORE
UNCERTAINTY ACROSS ERN MN.
/OUTLOOK FOR KMSP/
THU NIGHT...IFR CIGS/VSBYS WITH RAIN EARLY...THEN LIFR CONDITIONS
POSSIBLE IN DZ AND FG. WINDS SE AT 5-10 KTS.
FRI...IFR WITH DZ AND FG. LIFR POSSIBLE. WINDS SE AT 5-10 KTS.
SAT...MVFR WITH -SHSN POSSIBLE. COLD FRONT PASSAGE EARLY. WINDS W
AT 20G30KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
MPG/BORGHOFF
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
437 AM CST WED JAN 9 2013
.DISCUSSION...
MAIN FORECAST CONCERN FOR THIS PERIOD WAS IN THE THURSDAY THROUGH
SATURDAY TIME FRAME AS AN UNCHARACTERISTICALLY WARM AND MOIST
SYSTEM FOR JANUARY STANDARDS IMPACTS THE AREA...WITH WHAT LOOKS
TO BE PRIMARILY RAIN THURSDAY THROUGH FRIDAY...WITH A TRANSITION
BACK TO SNOW FRIDAY EVENING.
VERY MILD CONDITIONS TO START THE DAY...WITH MANY AREAS STILL IN
THE 30S AT 3AM AS THE AREA SITS OUT AHEAD OF PACIFIC COLD FRONT
CURRENTLY MOVING ACROSS THE DAKOTAS. CURRENT HIGHS FOR TODAY ONLY 5
TO 10 DEGS HIGHER THAN CURRENT TEMPS...SO COULD END UP BEING A BIT
WARMER THAN CURRENTLY FORECAST...ESPECIALLY EAST OF THE BUFFALO
RIDGE IN SW MN...WHERE TEMPS ARE A DEGREE OR TWO ON EITHER SIDE
OF 35 AT THE MOMENT. ALSO GETTING SOME STRONG WINDS IN THE WRN CWA
THIS MORNING...WITH SPEEDS UP NEAR ADVY LEVELS...WITH SOME
SUSTAINED WINDS IN THE AXN/MOX AREA NEAR 30 MPH...WITH GUSTS
APPROACHING 40. FORTUNATELY...NOT EXPECTING THINGS TO GET ANY
WORSE THAN WHAT WE HAVE ALREADY SEEN SINCE MAIN PUSH OF PRESSURE
RISES WILL BE GOING NORTH OF HERE...ALONG WITH A STRONG INVERSION
MAKING IT DIFFICULT TO MIX MUCH WIND TO THE GROUND. THIS SECOND
PART IS FORTUNATE...AS RAP SHOWS 1K FT WINDS UP AT 40 KTS...BUT
THE INVERSION WILL KEEP THOSE UP THERE...MEANING A WIND ADVY IS
UNNECESSARY FOR TODAY.
THE WEATHER LOOKS QUIET TODAY THROUGH TONIGHT...BUT STILL LOOKS
TO TURN SOUTH IN A HURRY THURSDAY AFTERNOON. CUT OFF LOW WITH A
WALL OF WATER OVER TX THIS MORNING WILL SLOWLY DRIFT NORTH TODAY
AS A SHARP THROUGH MOVES ONSHORE OUT WEST. AS THE MAIN TROUGH
WORKS ACROSS THE ROCKIES THURSDAY...IT WILL PICK UP THE CLOSED LOW
A QUICKLY SEND IT AND ITS RAIN NORTH TOWARD THE GREAT LAKES. AS
WITH PREVIOUS FORECAST...FAVORED A GEM/ECMWF BLEND FOR TIMING
PRECIP IN THURSDAY/THURSDAY NIGHT AS THIS IS A GOOD COMPROMISE
BETWEEN THE NAM...WHICH IS ABOUT 6 HOURS FASTER AND THE GFS WHICH
IS 6 HOURS SLOWER THAN THE GEM/ECMWF. HOWEVER...WORRIED NAM MAY BE
RIGHT WITH THE FASTER TIMING. THIS IS BECAUSE A QUICK LOOK AT H85
MOISTURE TRANSPORT ON THE ECMWF SHOWS THAT IT AGREES MUCH MORE
WITH THE TIMING INDICATED BY THE NAM QPF THAN ITS OWN...SO WOULD
NOT BE SURPRISED IF WE NEED TO START SPEEDING UP THE SPREAD OF
POPS NORTH THURSDAY AFTERNOON.
BIG ISSUE WITH PRECIP THURSDAY NIGHT THROUGH FRIDAY IS ALL MODELS
ARE SHOWING THE MPX CWA GETTING DRY SLOTTED...WITH MOISTURE
REMAINING RATHER SHALLOW AFTER THE INITIAL PUSH OF PRECIP THURSDAY
AFTERNOON. DID FAVOR QPF THU/THU NIGHT TOWARD THE HIGHER HPC
NUMBERS AS BOTH THE NAM AND GFS SHOW PWATS WITH THIS INITIAL SURGE
OF PRECIP INCREASE TO AND EVEN EXCEEDING 1 INCH. THIS IS A GOOD
400-500 PERCENT OF NORMAL. THE HIGHEST PWAT EVER OBSERVED AT
MPX/STC IN JANUARY IS 0.92...SO WHAT WE WILL BE SEEING THURSDAY
WILL BE QUITE RARE INDEED. BASED ON THE HIGH PWAT...LIKE THE
HIGHER HPC NUMBERS...THOUGH HEAVIEST RAIN WILL BE DIRECTED MORE
TOWARD GREEN BAY...WHERE BEST LLJ AND MOISTURE TRANSPORT WILL BE
DIRECTED. DRY SLOTTING THURSDAY NIGHT THROUGH FRIDAY RESULTS IN
SOUNDINGS LACKING ANY ICE CRYSTALS...WITH DRIZZLE LOOKING TO BE THE
PRIMARY PRECIP SEEN IN THIS PERIOD.
AS FOR P-TYPE...FAVORED TEMPERATURE FORECAST THU-FRI TOWARD THE
GEM/ECMWF AS WELL...WHICH RESULTS IN A MUCH WARMER SCENARIO. BY
THE TIME PRECIP GETS HERE THURSDAY AFTERNOON...CURRENTLY HAVE THE
ENTIRE CWA ABV FREEZING...SO KEPT PRECIP MENTION THURSDAY AS ONLY
RAIN. FOR THURSDAY NIGHT...MAY BE QUESTIONABLE IF LOWS ANYWHERE IN
THE MPX CWA DROP BELOW FREEZING...WHICH MEANS RAIN WILL LIKELY BE
THE PRIMARY P-TYPE RIGHT THROUGH THURSDAY NIGHT. ON
FRIDAY...MODELS BEGINNING TO REALLY TIGHTEN UP BAROCLINIC ZONE
THAT WILL BE JUST WEST/NW OF THE MPX AREA...WITH WINDS BACKING TO
THE SE. THIS SHOULD ALLOW 40 DEG TEMPERATURES TO SNEAK INTO ERN
AREAS FRIDAY. THIS FRONT DOES NOT LOOK TO START WORKING ACROSS
THE MPX CWA UNTIL FRIDAY NIGHT BASED ON AN ECMWF/GFS/NAM BLEND AS
A RAPIDLY DEEPENING SFC LOW MOVES UP FROM NEAR SIOUX FALLS UP TO
THE ARROWHEAD. NO OTHER WAY TO EXPLAIN THE CAA BEHIND THIS FRONT
FRIDAY NIGHT OTHER THAN AS INTENSE...WITH WIND ADVY STRENGTH WINDS
LOOKING LIKELY AND TEMPERATURES LIKELY DROPPING 20 DEGREES OR MORE
WITHIN AN HOUR OR TWO. THIS WILL QUICKLY TURN ANY PRECIP OVER TO
SNOW...THOUGH TRACK OF THE LOW WILL KEEP PRIMARY BAND OF SNOW
ACROSS NW MN.
LOOKING AT POTENTIAL HEADLINES...THERE WILL BE THE POSSIBILITY FOR
TWO WITH THIS SYSTEM...A WINTER WEATHER AND WIND ADVY. AT THE
MOMENT...THE MOST LIKELY PLACE THAT MAY NEED A WINTER WX ADVY IS
THE FAR NW CWA. THIS IS WHERE THE HIGHEST POTENTIAL FOR SEEING
FZRA WILL BE THURSDAY NIGHT...FOLLOWED BY THE POTENTIAL FOR A FEW
INCHES OF SNOW FRIDAY NIGHT INTO SATURDAY DEPENDING ON HOW FAR SE
THE DEFORMATION PRECIP BAND SETS UP. AS FOR THE WIND ADVY...FRIDAY
NIGHT IS LOOKING QUITE BREEZY...ESPECIALLY ON THE ECMWF...WHICH
DEVELOPS SUSTAINED WINDS IN WRN MN IN EXCESS OF 30 MPH...WITH
GUSTS OVER 40 MPH IN RESPONSE TO IT SENDING A 990 LOW OVER TO THE
WEST END OF LAKE SUPERIOR AS A 1030 MB HIGH MOVES INTO THE BLACK
HILLS.
AS FOR THE REST OF THE FORECAST...IT IS LOOKING COOLER...ESPECIALLY
SATURDAY THROUGH MONDAY...WHEN BELOW ZERO LOWS WILL RETURN WITH
HIGHS IN THE SINGLE DIGITS AND TEENS...THOUGH WE COULD GET WARMER
THAN THAT AS WARM TEMPS THURSDAY/FRIDAY WILL LIKELY PUNCH A LOT OF
HOLES IN THE SNOWPACK OUTSIDE OF THE NW CWA...WHICH WILL LIKELY
GET SOME SNOW FRIDAY NIGHT. BY THE MIDDLE OF THE WEEK...BOTH THE
GFS/ECMWF SHOW TEMPERATURES MODERATING OUT AHEAD OF CLIPPER COMING
DOWN TUESDAY NIGHT/WEDNESDAY. ALSO INTERESTING IS THAT AS NEXT
WEEK GROWS CLOSER...THE GFS/ECMWF CONTINUE TO BACK OFF ON THE
EXTENT TO WHICH THE ARCTIC AIR MAKES IN INTO THE US...WITH EACH
NEW RUN SEEMING TO KEEP IT FURTHER AND FURTHER NORTH...SO THAT WILL
BE SOMETHING TO WATCH. AS FOR WEATHER...AFTER THURSDAY NIGHT
THROUGH SATURDAY IT LOOKS DRY.
&&
.AVIATION.../06Z TAF ISSUANCE/
BATCH OF MVFR CEILINGS MOVING QUICKLY EAST AND SHOULD EXIT
KEAU/KRNH BY 08Z. NEXT LOBE OF MVFR CEILINGS IN ERN ND WHICH IS
MOVING ESE. LATEST RAP BRUSHES AXN/STC/RNH AND HAVE ADDED A TEMPO
GROUP FOR SOME BROKEN 2000-2500 FOOT CEILINGS. OTHERWISE SOME
GUSTY WNW WIND THROUGH MIDDAY UNTIL SURFACE RIDGE APPROACHES.
QUICK TRANSITION TO SOUTHERLY WINDS LATER WED AFTERNOON.
KMSP... BROKEN MID LEVEL CLOUDS THE REST OF THE NIGHT. LOBE OF STRATUS
IN ERN ND AROUND 2000 FEET AGL AND MOVING ESE. THIS SHOULD REMAIN
NORTH OF KMSP BUT HAVE ADDED SOME SCATTERED CLOUDS FOR THIS AROUND
11Z. ONLY A SMALL CHANCE OF THIS GOING BROKEN. WINDS GUSTING OVER
20 KNOTS SHOULD REMAIN WEST OR WNW BEFORE BECOMING SOUTH LATE WED
AFTERNOON.
/OUTLOOK FOR KMSP/
THU...VFR MORNING BECOMING MVFR CIGS/VSBYS LATE AFTERNOON.
THU NIGHT...IFR CIGS/VSBYS WITH LIFR AND -FZRA POSSIBLE. WINDS SE
AT 10-15KTS.
FRI...IFR WITH -RA. LIFR POSSIBLE. WINDS SSW AT 5-10KTS.
SAT...MVFR WITH -RASN POSSIBLE. COLD FRONT PASSAGE EARLY. WINDS
SSW AT 10KTS BECOMING NW AT 15G25KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
MPG/TDK
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
942 AM EST WED JAN 9 2013
.DISCUSSION...RAIN GRADUALLY SPREADING NE THIS MORNING WITH SOME
LIGHT ACCUMULATIONS MAINLY NOTED OVER THE WRN THIRD OF THE FORECAST
AREA. LATEST RUC MODEL RUN SPREADS THESE LIGHT ACCUMULATIONS INTO
MUCH OF THE TN VALLEY AND INTO LEE/WISE COUNTIES OF SW VA OVER THE
NEXT FEW HOURS. PLAN TO UPDATE THE FORECAST GRIDS AND PRODUCTS
SHORTLY WITH AN INCREASE IN POPS FOR THOSE AREAS. PROBABLY WILL STAY
WITH NO MORE THAN HIGH CHANCE POPS FOR THE FAR NE AREAS.
12Z OHX SOUNDING HAD VERY HIGH PRECIPITABLE WATER VALUE OF 1.32
INCHES...AND THIS MOISTURE WILL BE WORKING EASTWARD THROUGH THE
WEEKEND. STAY TUNED FOR SOME WET WEATHER INTO THE MIDDLE OF NEXT
WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN 59 48 66 55 69 / 60 50 40 60 60
KNOXVILLE MCGHEE TYSON AIRPORT, TN 58 46 66 51 66 / 40 40 40 60 60
OAK RIDGE, TN 57 46 65 52 67 / 40 40 40 50 60
TRI CITIES AIRPORT, TN 55 43 64 45 64 / 30 20 30 30 30
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
TG
AREA FORECAST DISCUSSION
NWS PUEBLO CO
247 PM MST WED JAN 9 2013
.SHORT TERM...
(TONIGHT AND TOMORROW)
...MAIN SHORT TERM CONCERN IS THE CHANCE OF RAIN AND FREEZING RAIN
ACROSS THE FAR SE PLAINS...
CURRENT WATER VAPOR IMAGERY AND UPPER AIR ANALYSIS INDICATING WEAK
MAINLY WESTERLY FLOW ALOFT ACROSS THE AREA WITH A LARGE UPPER LOW
STILL SPINNING ACROSS NORTHEASTERN MEXICO JUST SOUTH AND WEST OF DEL
RIO TEXAS AT THIS TIME. WATER VAPOR IMAGERY INDICATING MID AND UPPER
LEVEL MOISTURE ASSOCIATED WITH THIS SYSTEM SPREADING NORTH INTO
EASTERN NEW MEXICO AND WESTERN TEXAS...WITH MID AND UPPER LEVEL
MOISTURE ALSO SPREADING INTO THE GREAT BASIN REGION AHEAD OF A
DEVELOPING STORM SYSTEM MOVING ONSHORE ACROSS THE PAC NW COAST AT
THIS TIME. WITH THE LIGHT WINDS...TEMPERATURES HAVE STRUGGLED TO
WARM WITH READINGS IN THE MID 40S TO LOWER 50S ACROSS THE LOWER
ELEVATIONS AND 20S AND 30S ACROSS THE HIGHER ELEVATIONS. TEMPS IN
THE SAN LUIS VALLEY CONTINUE TO LAG BEHIND WITH READINGS MAINLY IN
THE TEENS AND 20S...WITH THE COLDEST READINGS IN THE CENTRAL
PORTIONS OF THE VALLEY.
TONIGHT...MODELS STILL DIFFER ON LOCATION OF EJECTING LOW WITH THE
12Z GFS AND EC THE FURTHEST NORTH AND WEST WITH THE LOW NORTH OF
ABILENE TEXAS AT 12Z THU...WHERE AS THE HIGHER RES NAM AND RAP KEEP
THE LOW FURTHER SOUTH AND EAST. THE FURTHER NORTH SOLUTIONS OF THE
EC AND ESPECIALLY THE GFS ARE INDICATING STRONGER MID LEVEL WAA
ACROSS THE WESTERN TX AND OKLAHOMA PANHANDLE THROUGH EASTERN
COLORADO AND WESTERN KANSAS AND ARE PRINTING OUT MORE QPF ACROSS THE
FAR SOUTHEAST PLAINS AS A RESULT. THE HIGHER RES MODELS KEEP THE
BEST LIFT AND WAA FURTHER EAST ACROSS WESTERN AND CENTRAL KANSAS
WHICH IS ALSO SUPPORTED BY LOCAL HIGH RES WRF MODEL. WITH THAT
SAID...HAVE KEPT CURRENT FORECAST TRENDED TOWARDS THE HIGHER RES
MODELS KEEPING SILENT POPS THROUGH 06Z WITH CHANCE POPS ACROSS
EASTERN PORTIONS OF BACA AND PROWERS COUNTIES AND SLIGHT POPS
FURTHER NORTH AND WEST INTO KIOWA AND WESTERN PROWERS AND BACA
COUNTIES THEREAFTER. SOUNDINGS INDICATING MAINLY LIGHT RAIN ACROSS
BACA COUNTY THOUGH DO INDICATE A BRIEF PERIOD OF LIGHT FREEZING RAIN
POSSIBLE ACROSS PROWERS AND KIOWA COUNTIES...WITH LATER SHIFTS
NEEDING TO MONITOR LATEST MODELS AND TRENDS. ELSEWHERE...WEAK
WESTERLY FLOW THIS EVENING BECOMES MORE SOUTHWEST AND SLOWLY
INCREASES OVERNIGHT AS EASTERN PACIFIC SYSTEM CONTINUES TO MOVE
ONSHORE ACROSS THE WEST COAST. MAINLY CLEAR SKIES WEST OF THE PLAINS
WILL HELP COOL TEMPS ONCE AGAIN IN THE SAN LUIS VALLEY...WITH THE
WARMEST READINGS EXPECTED ACROSS THE HIGHER TERRAIN ALONG AND WEST
OF THE I-25 CORRIDOR WHERE LEE TROUGHING DEVELOPS OVERNIGHT.
TOMORROW...SOUTHWEST FLOW ALOFT CONTINUES TO INCREASE THROUGH THE
DAY AS THE WEST COAST SYSTEM TRANSLATES INTO THE GREAT BASIN.
MOISTURE PROGGED TO INCREASE FROM WEST TO EAST AND WITH INCREASING
OROGRAPHICS COULD SEE SOME LIGHT SNOW DEVELOPING ACROSS THE HIGHER
TERRAIN OF THE SOUTHWEST MTS BY THE LATE AFTERNOON. LEE TROUGHING
STRENGTHENS ACROSS THE I-25 CORRIDOR WITH BREEZY SOUTH TO SOUTHWEST
WINDS DEVELOPING ACROSS THE PLAINS BOOSTING TEMPS INTO THE LOWER TO
MID 50S. INCREASING CLOUDS AND SLIGHT COOLING ALOFT WILL LEAD TO
SLIGHTLY COOLER TEMPS ACROSS THE HIGHER TERRAIN AND HIGH VALLEYS.
.LONG TERM...
(THURSDAY NIGHT THROUGH WEDNESDAY)
...HIGH IMPACT WEATHER TO AFFECT PORTIONS OF SOUTH CENTRAL AND
SOUTHEAST COLORADO THURSDAY NIGHT THROUGH FRIDAY...WITH A TURN
TOWARDS MUCH COLDER TEMPERATURES THROUGH THE WEEKEND INTO EARLY NEXT
WEEK...
A CLOSED UPPER LOW CARVES OUT ACROSS THE GREAT BASIN THURSDAY NIGHT
SENDING STRONG SOUTHWEST FLOW...WITH 110-120+ KT UPPER JET ACROSS
COLORADO BY 12Z FRIDAY. MOISTURE DEEPENS ALONG THE CONTINENTAL
DIVIDE THURSDAY EVENING...WITH SNOW RAMPING UP ALONG THE
OROGRAPHICALLY FAVORED EASTERN SAN JUAN MOUNTAINS. COMBINED WITH
MTN TOP WINDS OF 50-60 KTS...HAZARDOUS CONDITIONS WILL BE POSSIBLE
DUE TO WHITE OUT CONDITIONS IN BLOWING SNOW ACROSS ZONE 68...WHICH
INCLUDES THE WOLF CREEK PASS. HAVE UPGRADED THE WINTER STORM WATCH
TO A BLIZZARD WATCH FOR THIS ZONE. SNOW SHOULD SPREAD NORTH AND
EASTWARD AFTER MIDNIGHT THROUGH THE MORNING HOURS...WITH THE
HEAVIEST SNOW EXPECTED TO FALL BEFORE 18Z WHEN BEST FORCING MOVES
THROUGH. WINDS THEN SHIFT MORE FROM THE WEST TO NORTHWEST FRIDAY
AFTERNOON...WITH THE FOCUS FOR SNOW SHIFTING INTO THE EASTERN
SAWATCH AND WESTERN MOSQUITO RANGES DURING THE AFTERNOON. OVERALL
SNOWFALL AMOUNTS FOR THE BRUNT OF THE EVENT...THURS
NIGHT/FRI...SHOULD RANGE FROM 8 TO 17 INCHES ACROSS THE EASTERN SAN
JUAN MOUNTAINS...WITH AROUND 5 TO 10 INCHES WITH LOCALLY UP TO A
FOOT FOR THE LA GARITAS...EASTERN SAWATCH AND WESTERN MOSQUITO
RANGES. THINK THAT THESE LATTER AREAS WILL EVENTUALLY NEED A WINTER
WEATHER ADVISORY...BUT SINCE SNOW AMOUNTS HAVE BEEN CONSISTENTLY
COMING UP SHORT OF WARNING NUMBERS (12" OR MORE IN GREATER THAN 12
HOURS)...NO WATCHES WILL BE ISSUED AT THIS POINT.
AS THE UPPER JET TRANSLATES ACROSS THE AREA THURSDAY NIGHT THROUGH
FRIDAY...A BORA COLD FRONT WILL MOVE FROM WEST TO EAST ACROSS THE
REGION. HIGHER PEAKS SHOULD START BLOWING FIRST AS MTN TOP WINDS
INCREASE TO AROUND 50-60 KTS. THERE IS QUITE A BIT OF FORWARD SHEAR
WITH THIS SYSTEM...SO THIS DOESN`T APPEAR TO BE A MTN WAVE EVENT.
HOWEVER AS THE NORTH-SOUTH ORIENTED COLD FRONT CROSSES THE
MOUNTAINS...IT COULD BRING A PERIOD OF STRONG GUSTY WINDS INTO THE
ADJACENT LOWER ELEVATIONS OF THE SAN LUIS VALLEY AND THE I-25
CORRIDOR EARLY FRIDAY MORNING AS COLD DENSE AIR SPILLS OVER THE
MOUNTAINS. SFC PRESSURE GRADIENT IS IMPRESSIVE FRIDAY MORNING AS
THE SURFACE LOW DEEPENS ACROSS NORTHEAST COLORADO WHICH SHOULD ALSO
AID IN MIXING STRONG WINDS ALOFT TO THE SURFACE ACROSS THE REMAINDER
OF THE SOUTHEAST PLAINS. ALREADY HAVE A HIGH WIND WATCH OUT AND PLAN TO
MAINTAIN IT. DID BUMP UP THE START TIME OF THE HIGH WIND WATCH TO
MIDNIGHT ACROSS THE SOUTHEAST MTS AS WINDS ALOFT WILL BE INCREASING
AFTER MIDNIGHT...THOUGH THINK STRONGER GUSTS WILL STAY ACROSS THE
HIGHER ELEVATIONS UNTIL FRIDAY MORNING WHEN THE FRONT MOVES THROUGH. WINDS
MAY COME UP JUST SHY OF HIGH WIND CRITERIA ACROSS CENTER PORTIONS OF
THE SAN LUIS VALLEY...BUT VALLEY EDGES...PARTICULARLY ON THE WESTERN
SIDE COULD SEE A PERIOD OF HIGH WINDS FRIDAY MORNING.
BROAD TROFFING REMAINS ACROSS THE GREAT BASIN AND ROCKIES REGION
THROUGH EARLY NEXT WEEK AS ENERGY CONTINUES TO DROP SOUTHWARD OUT OF
CANADA. THIS WILL KEEP VERY COLD AND GENERALLY UNSETTLED CONDITIONS
ACROSS THE REGION THROUGH EARLY NEXT WEEK. TEMPERATURES WILL DROP
OFF CONSIDERABLY ACROSS THE PLAINS...WITH HIGHS STRUGGLING TO REACH
THE 30S BY THE MIDDLE OF NEXT WEEK. MEANWHILE...THE MOUNTAINS AND
VALLEYS WILL BE DROPPING INTO THE NEGATIVE DIGITS AT NIGHT...WITH
KALS LIKELY TO HIT -30 OR BELOW AS A NEW BATCH OF COLD AIR GETS
ENTRENCHED IN THE VALLEY. NEXT WAVE OF ENERGY LIFTS OUT OF THE MEAN
TROF ACROSS SOUTHERN PORTIONS OF THE AREA SAT NIGHT...AND WITH
SHALLOW UPSLOPE AND COLD AIR...WE COULD SEE SOME ADDITIONAL LIGHT
SNOW ACROSS THE MOUNTAINS AND ADJACENT PLAINS...BUT EACH SUCCESSIVE
MODEL RUN HAS BEEN DRIER...SO WILL LEAVE THE SILENT POPS ACROSS THE
PLAINS...WITH GENERALLY ISOLATED TO LOW END SCATTERED POPS ACROSS
THE MOUNTAINS. SAME THING HAPPENS FOR MONDAY NIGHT AS ANOTHER WAVE
OF ENERGY DROPPING INTO THE BASE OF THE TROF CLOSES OFF AN UPPER LOW
ACROSS THE DESSERT SOUTHWEST AND LEADING SHORTWAVE ENERGY EJECTS TO
THE NORTHEAST ACROSS THE AREA. ONCE AGAIN...IF IT OCCURS...ANY
SNOWFALL ACCUMULATIONS APPEAR TO REMAIN LIGHT. GFS AND ECMWF ORPHAN THE
UPPER LOW ACROSS EXTREME SOUTHERN AZ/NRN OLD MEXICO THROUGH
WEDNESDAY WHICH IS TOO FAR SOUTH TO BRING ANY PRECIPITATION TO THE
AREA THROUGH WEDNESDAY. TEMPERATURES SHOULD SLOWLY MODERATE SOME
INTO THE MIDDLE OF NEXT WEEK. -KT
&&
.AVIATION...
VFR CONDITIONS TO PREVAIL AT KCOS AND KPUB THROUGH THE NEXT 24
HOURS WITH GENERALLY LIGHT WINDS THROUGH TONIGHT. BREEZY SOUTH TO
SOUTHWEST WINDS OF 15-20KTS ARE EXPECTED TO DEVELOP AFT 18Z THU.
KALS HAD STRONG RADIATIONAL COOLING AND SCT001 TO LOCALLY BKN001
ACROSS THE VALLEY FLOOR LATE LAST NIGHT AND EARLY THIS MORNING...BUT
VIS DID NOT DROP BELOW MFVR. WOULD THINK THE SAME FOR TONIGHT...AS
TEMPS DID NOT WARM AS MUCH AS EXPECTED. AT ANY RATE...VFR CONDITIONS
EXPECTED THROUGH 06Z THU...WITH LOCAL IFR AND LIFR CIGS THEN
POSSIBLE THROUGH 16Z. VFR AGAIN AFT 16Z THU. -MW
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WATCH FROM FRIDAY MORNING THROUGH FRIDAY AFTERNOON FOR
COZ069>071-083>089-093>099.
HIGH WIND WATCH FROM LATE THURSDAY NIGHT THROUGH FRIDAY
AFTERNOON FOR COZ072>082.
BLIZZARD WATCH FROM THURSDAY EVENING THROUGH FRIDAY AFTERNOON
FOR COZ068.
&&
$$
23/31
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
935 AM MST WED JAN 9 2013
.UPDATE...
&&
.SHORT TERM...LATEST LAPS SURFACE ANALYSIS SHOWING LOW PRESSURE
BEGINNING TO DEVELOP ALONG THE FRONT RANGE IN RESPONSE TO UPPER
LOW OVER MEXICO AND UPPER TROUGH MOVING INTO THE PACIFIC
NORTHWEST. GUSTY SOUTHWESTERLY HAVE DEVELOPED ACROSS MUCH OF THE
PLAINS...ROUGHLY AREAS SOUTH OF INTERSTATE 70. WILL NEED TO
INCREASE WINDS ACROSS PLAINS A BIT FOR THIS AFTERNOON. WINDS STILL
EXPECTED TO INCREASE THIS EVENING AS BOUNDARY LAYER SOUTHEAST
GRADIENT STRENGTHENS. REST OF FORECASTS LOOK ON TRACK FOR NOW.
.AVIATION...GUSTY SOUTHWEST WINDS HAVE DEVELOPED ACROSS DEN DUE TO
THE DEVELOPMENT OF SURFACE LOW PRESSURE ALONG THE FRONT RANGE. THE
GUSTY WINDS SHOULD CONTINUE INTO THE EVENING. WILL CONTINUE THE
TREND OF THE LATEST TAFS FOR THE UPCOMING ISSUANCE. LATEST HRRR
AND TO A LESSER EXTENT THE RAP SHOW A WEAK BOUNDARY MOVING INTO
THE DENVER AREA AROUND 00Z...WEAKENING THE SOUTHERLY WINDS. NOT
SURE IF THIS BOUNDARY WILL AFFECT DEN...AND WILL WAIT TO SEE WHAT
DEVELOPS.
&&
.PREV DISCUSSION... /ISSUED 329 AM MST WED JAN 9 2013/
SHORT TERM...UPPER LOW TRACKING SLOWLY NORTHEASTWARD OVER WRN
TEXAS/WRN OKLA DURING THE NEXT 24 HOURS WILL SEND HIGH CLOUDS
NORTHWARD OVER SOUTHERN AND EASTERN SECTIONS OF THE FORECAST AREA
DURING THE DAY. OTHERWISE MID-LEVEL SUBSIDENCE AND A DRIER NWLY
FLOW ALOFT SHOULD KEEP SKIES GENERALLY CLEAR FOR THE REMAINDER OF
THE FCST AREA AND TEMPERATURES ABOVE AVERAGE TODAY. THE HIGH MTN
VALLEYS SHOULD ALSO SEE TEMPERATURE READINGS MODERATE TODAY AS
THE STG SFC BASED INVERSIONS OF THE PAST SEVERAL DAYS CONTINUE TO
WEAKEN...ALLOWING WARMER AIR ALOFT TO MIX DOWN. HIGHS TODAY ON
THE PLAINS GENERALLY 8-12 DEG F ABOVE AVERAGE. AVERAGE HIGH AT
DENVER THIS TIME OF YEAR IS 44F. NEXT...MODELS PARTICULARLY THE
NAM SHOW SOUTHERLY SFC/BNDRY LAYER WINDS INCREASING ON THE PLAINS
DURING THE AFTERNOON WITH PRESSURE FALLS TO OUR NORTH. STRONGEST
WINDS...IN THE 15-25 KT RANGE...SHOULD DEVELOP ROUGHLY EAST OF A
STERLING TO ELBERT/KIOWA LINE. OVERNIGHT...FURTHER STRENGTHENING
OF THESE SOUTH-SOUTHEASTERLY SFC/BNDRY LAYER WINDS IS FORECASTED.
MODELS ALSO INDICATE AN INCREASE IN MID AND HIGH LEVEL MOISTURE
OVER FAR EASTERN SECTIONS OF THE CWFA AS THE UPPER LOW PASSES TO
OUR SOUTHEAST. THE GUSTY WINDS SHOULD KEEP THE BNDRY LAYER
ADEQUATELY MIXED RESULTING IN WARMER OVERNIGHT TEMPERATURES IN
THIS AREA.
LONG TERM...SW FLOW ALOFT WILL BE OVER THE AREA ON THU AHEAD OF
AN UPPER LEVEL TROUGH OVER THE WRN US. SFC LOW PRESSURE WILL
DEVELOP FM SERN WY INTO ERN CO WITH DOWNSLOPE FLOW EAST OF THE
MTNS. ALTHOUGH SOME MID AND HIGH LEVEL MOISTURE WILL INCREASE BY AFTN
IT SHOULD BE DRY ACROSS THE RGN. ONE MORE MILD DAY WILL OCCUR OVER
NERN CO WITH READINGS IN THE LOWER TO MID 50S EXCEPT OVER THE FAR
NERN CORNER WHERE READINGS WILL BE MAINLY IN THE UPPER 40S.
FOR THU NIGHT INTO FRI THE UPPER LEVEL TROUGH WILL BEGIN TO MOVE
EASTWARD WITH AN UPPER LEVEL LOW OVER SWRN WY BY FRI AFTN.
MEANWHILE SFC LOW PRES WILL INTENSIFY OVER ERN CO AS A CDFNT MOVES
NR THE WY-CO BORDER BY 12Z. CROSS-SECTIONS SHOW SWLY FLOW IN THE
MTNS THRU FRI AFTN WITH THE BEST CHC OF SNOW IN ZNS 31 AND 33 SO
THAT IS WHERE I WILL HAVE THE HIGHEST POPS. OVER NERN CO LATEST
00Z RUNS ARE NOT AS FAVORABLE FOR SNOW LATE FRI AFTN INTO FRI
EVENING AS 12Z RUNS WERE DUE TO LESS MOISTURE...LACK OF QG
ASCENT AND WEAKER UPSLOPE. HOWEVER LAPSE RATES ARE STILL FCST NR
8 C/KM FRI EVENING SO IF MOISTURE IS MORE LIKE 12Z RUNS THEN THERE
COULD STILL BE A PERIOD OF SNOW SO WILL LEAVE IN CHC POPS FOR LATE
FRI AFTN INTO FRI EVENING. AS FOR HIGHS ON FRI OVER NERN CO THE
FNTL BNDRY IS SLOWER AS COMPARED TO THE 12Z RUNS. AT THIS POINT
WILL KEEP HIGHS IN THE 30S EXCEPT OVER SRN LINCOLN COUNTY WHERE
READINGS MAY GET INTO THE 40S.
BY LATE FRI NIGHT THE UPPER LEVEL TROUGH WILL EXIT THE RGN AS A
SECOND FEATURE MOVES SE INTO THE AREA ON SAT. ALTHOUGH THERE IS
ONLY SOME WK QG ASCENT THRU THE DAY LAPSE RATES WILL STILL BE
RATHER UNSTABLEL SO EXPECT SOME LIGHT SNOW IN THE MTNS. OVER NERN
CO AM NOT COMPLETELY CONVINCED ITS GOING TO BE PCPN FREE
ESPECIALLY IN AND NR THE FOOTHILLS WHERE WEAK UPSLOPE FLOW WILL
EXIST AS A SECONDARY SURGE OF COLDER AIR MOVES IN. THUS WILL KEEP
IN SOME LOW POPS MAINLY WEST OF I-25. HIGHS ON SAT WILL GENERALLY
RANGE FROM 15-20 DEGREES OVER NERN CO.
FOR SUN THRU MON BOTH THE ECMWF AND GFS SHOWS A BROAD UPPER LEVEL
TROUGH OVER THE RGN ALTHOUGH TO SOME EXTENT THEY SHOW A SECONDARY
UPPER LEVEL LOW DEVELOPING OVER THE GREAT BASIN SUN NIGHT INTO MON
AS ANOTHER SURGE OF COLDER AIR MOVES INTO NERN CO. THE ECMWF IS
MUCH DRIER THAN THE GFS BOTH DAYS AND WOULD ONLY HAVE A SLIGHT CHC
OF SNOW IN THE MTNS. ON THE OTHER HAND THE GFS HAS MORE MOISTURE
ESPECIALLY SUN NIGHT INTO MON WHICH WOULD LEAD TO A CHC OF SOME
LIGHT SNOW IN THE MTNS AND ALONG THE FRONT RANGE. CONSIDERING HOW
VASTLY DIFFERENT THE MOISTURE FIELDS ARE IN THE MODELS FOR NOW
WILL ONLY MENTION A SLIGHT CHC OF SNOW IN THE MTNS. TEMPS WILL
CONTINUE WELL BLO NORMAL BOTH SUN AND MON WITH READINGS OVER NERN
CO STILL HAVING A HARD TIME GETTING ABV 20 DEGREES.
AVIATION...VFR CONDITIONS ANTICIPATED AT DENVER AREA AIRPORTS AND
SOUTH-SOUTHEAST WINDS OF 7-14KTS AT DIA AND APA FOR THE NEXT 24
HOURS. MEANWHILE LIGHT SLY BREEZES AT BJC THIS MORNING ARE
EXPECTED TO BECOME EAST-NORTHEAST AT SPEEDS UNDER 10 KTS THIS
AFTERNOON WITH THE FORMATION OF A WEAK DENVER CYCLONE ON THE
NORTH SIDE OF THE METRO AREA. OVERNIGHT...THERE IS A CHANCE THAT
DIA AND APA COULD SEE SOUTH-SOUTHEAST WINDS OF 15-22KTS SOMETIME
BETWEEN 04Z-10Z ACCORDING TO THE FCST MODELS SHOULD THE CORE OF
STRONGEST SLY WINDS ON THE PLAINS SHIFT FARTHER WEST THAN
EXPECTED.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...D-L
LONG TERM....RPK
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
335 PM EST WED JAN 9 2013
.SYNOPSIS...
WEAK COLD FRONT SWINGS THROUGH THE REGION LATE TONIGHT INTO THURSDAY
MORNING. HIGH PRESSURE RE-ESTABLISHES ITSELF ACROSS THE AREA ON
THURSDAY AND SLOWLY MOVES OFF TO THE EAST THROUGH THE WEEKEND.
ANOTHER LOW PRESSURE SYSTEM WILL BEGIN TO IMPACT THE REGION LATE ON
SUNDAY AS IT PUSHES ITS ASSOCIATED COLD FRONT THROUGH THE AREA BY
MONDAY. THE FRONT SHOULD DROP TO OUR SOUTH ON TUESDAY AND WEDNESDAY
AS HIGH PRESSURE FILLS BACK IN.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
THE GFS INITIALIZATION LOOKED BETTER THAN THE WRF-NMMB AND THERMAL
FIELDS WERE USED MORE SO THAN THE WRF-NMMB WHICH WAS COLDER THROUGH
THURSDAY.
THE JET STREAK AND A SHORT WAVE WAS ENOUGH TO GENERATE SOME
SPRINKLES AROUND OUR CWA. HRRR HAS A GOOD HANDLE ON RADAR ECHOES AND
WAS USED INTO EARLY THIS EVENING.
THE SHORT WAVE EXITS QUICKLY AND BASED ON UPSTREAM SATELLITE
IMAGERY, WE DO CLEAR THE SKIES QUICKLY THIS EVENING. THE WRF-NMMB
DOES TRAP MOISTURE UNDERNEATH THE DEVELOPING INVERSION WHICH BRINGS
BACK SHADES OF LAST WEEK. BUT UNLIKE LAST WEEK, WE ARE NOT SEEING
ANY UPSTREAM STRATOCU AND THE LOW HEIGHT OF THE INVERSION IS WELL
WITHIN THE DOWNSLOPING FLOW. ONE AREA OF CONCERN IS FAR NORTH WHERE
SOME LAKE EFFECT FLOW SHOULD OCCUR TONIGHT. RIGHT NOW THE TRAJECTORY
IS NORTHEAST OF OUR CWA.
THERE COULD BE SOME GUSTINESS, IN PARTICULAR THIS EVENING AS THE
FRONT MOVES THROUGH. BUT AS JANUARY EVENINGS GO, THIS IS NEARLY
SEASONAL. FOR MIN TEMPS A STAT GUIDANCE COMPROMISE WAS USED.
BOUNDARY LAYER WINDS SHOULD BE STRONG ENOUGH TO PREVENT TOTAL
DECOUPLING.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/...
AS JANUARY DAYS GO, UNLESS ONE IS LOOKING FOR SNOW, THURSDAY SHOULD
BE PRETTY PRETTY GOOD. THE NEXT HIGH PRESSURE SYSTEM WILL BE NEARING
AND THE RIDGE AXIS IS FORECAST TO STILL BE WEST OF OUR CWA. THE
FORECAST CONVECTIVE TEMPERATURE IS BEYOND REACH. WE ARE ONLY
EXPECTING SOME CIRRUS. VERY SHALLOW COLD, OK COOLER, AIR IN PLACE
FOR THE DAY. THE FORECAST WINDS ARE NOT EXPECTED TO BE THAT STRONG
AND NEITHER IS THE JANUARY SUN. SO THROUGH THE DAY, THE INVERSION
SHOULD HOLD AND WE WERE CONSERVATIVE WITH MAX TEMPS, LEANING TOWARD
A STAT GUIDANCE COMPROMISE. FULL SUN MACROS OFF THE GFS SOUNDINGS
SUPPORT NAM MOS MORE THAN GFS MOS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
5-WAVE MODEL GUIDANCE SHOWS THAT THE DOMINANT SOUTHEAST RIDGE VERY
SLOWLY FLATTENS OUT BY MID NEXT WEEK. THIS IS DUE TO DEEPER CENTRAL
UNITED STATES LONGWAVE TROUGHING AS A MASSIVE RIDGE BUILDS INTO THE
PACIFIC NORTHWEST.
HIGH PRESSURE RETURNS FOR A TIME PERIOD ON FRIDAY WHILE THE ONCE
STRONG SOUTHWEST CUT-OFF LOW EJECTS TOWARDS THE NORTHEAST AND
PASSES THROUGH THE GREAT LAKES. HAVING LOST ITS PHASING WITH A
NORTHERN STREAM SYSTEM AND UNABLE TO SUPPORT ITSELF ANY FURTHER, THE
LOW IS FORCED TO OPEN UP AS IT TRIES, BUT FAILS, TO CUT INTO THE TOP
OF THE EAST COAST RIDGE. IT THEN GETS PICKED UP BY THE 170KT JET
OVERHEAD AND IS SWEPT THROUGH THE NORTHEAST. DEPENDING ON HOW MUCH
REMAINING MOISTURE IS INVOLVED WITH THIS SYSTEM DICTATES HOW FAST WE
CAN SATURATE THE COLUMN AND SEE AN ACCUMULATING PRECIPITATION.
TEMPERATURES ACROSS THE NORTH WILL BE BELOW FREEZING FOR A FEW HOURS
DURING THE FORECASTED ONSET OF PRECIPITATION, I.E. FREEZING RAIN IS
POSSIBLE. THERE WAS AN EVENT MUCH LIKE THIS ABOUT A MONTH AGO WHERE
THE COLD AIR AT THE SURFACE WAS ERODED PRIOR TO ANY PRECIPITATION
FALLING DUE TO A VERY DRY COLUMN. THIS ONE LOOKS TO BE TRENDING IN
THE SAME DIRECTION ALTHOUGH NOT WITH THE TEMPERATURES RISING
OVERNIGHT BUT RATHER THE P-TYPE ISSUES.
BY LATE FRIDAY MORNING OUR SURFACES TEMPERATURES WILL ALL BE ABOVE
FREEZING WITH MORE RAIN ON THE WAY UP FROM THE SOUTHWEST...NORTHERN
ZONES HAVE THE HIGHEST CHANCES. THIS SHORTWAVE THEN SKIRTS OFF TO
THE NORTHEAST LATE FRIDAY NIGHT AND THE SOUTHEAST RIDGE
RE-ESTABLISHES ITSELF ALONG THE EAST COAST. THIS KEEPS A STRONG
SOUTHWESTERLY SURGE ALOFT ULTIMATELY ALLOWING TEMPERATURES TO CLIMB
WELL ABOVE NORMAL ON SATURDAY AND SUNDAY. THIS ALSO KEEPS MOST, IF
NOT ALL, THE SHORTWAVE ENERGY TO OUR NORTHWEST HEADING INTO SOUTHERN
ONTARIO. THE NEXT CHANCE OF PRECIPITATION WILL BE ON SUNDAY INTO
MONDAY AS A STRONGER COLD FRONT DROPS THROUGH FROM THE NORTHWEST.
THE SOUTHEAST RIDGE SHOULD KEEP THE FRONT FROM TRAVELING TOO FAR TO
OUR SOUTH. THIS WILL ALLOW THE BAROCLINIC ZONE TO FUNNEL A FEW MORE
PIECES OF ENERGY THROUGH OUR REGION ON TUESDAY AND WEDNESDAY. THE
MID-LEVEL FLOW TURNS A BIT MORE ZONAL AND THIS WILL ALLOW SOME
COLDER AIR TO BLEED INTO THE REGION FROM THE NORTHWEST...THOUGH WE
ARE NOT LOOKING AT A SUBSTANTIAL COOL DOWN BY ANY MEANS, MORE OF A
RETURN TO SLIGHTLY ABOVE NORMAL TEMPERATURES. IF TEMPERATURES CAN
COOL ENOUGH ALOFT ON WEDNESDAY WE COULD SEE A CHANGE OVER FROM RAIN
TO SNOW SHOWERS FALLING AS FAR SOUTH AS THE LEHIGH VALLEY. ALTHOUGH
WE WILL REMAIN MILD THROUGH A LOT OF THE EXTENDED WE WILL ALSO
REMAIN UNSETTLED.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THE 18Z TAFS CONTINUED THE PREDOMINATELY VFR FORECAST. WE DID NOT
FOLLOW ONE OF OUR COMPUTER MODELS THAT DEVELOPS AN IFR STRATUS
CIG AROUND MIDNIGHT TONIGHT.
FOR THIS AFTERNOON, A MID LEVEL CIG WILL CONTINUE TO MOVE ACROSS THE
TERMINALS. WINDS ALOFT ARE INCREASING AND WE START SOME GUSTINESS
TOWARD EVENING. THERE COULD BE SOME SPRINKLES AT THE TERMINALS, NO
VSBY RESTRICTIONS EXPECTED FROM THEM. BUT THE FOG AND HAZE HAS BEEN
TOUGH TO DISLODGE FROM KABE AND KRDG, THE MIXING HAS NOT COME TO
FRUITION.
THE COLD FRONT WILL MOVE THROUGH THE TERMINALS EARLY THIS
EVENING. WE ARE EXPECTING GUSTINESS FROM THE WEST AND NORTHWEST
AROUND ITS PASSAGE TIME AND IN THE COLD AIR ADVECTION BEHIND IT
FOR A COUPLE OF HOURS. PEAK GUSTS SHOULD BE 15 TO 20 KTS. THERE
SHOULD BE ENOUGH MIXING TO PREVENT LLWS CONDITIONS. WINDS AT 2K
ARE FORECAST TO AVERAGE 40KT. SKIES SHOULD CLEAR.
WE ARE NOT FORECASTING GUSTS OVERNIGHT. THE NEW AND FRESHER
COLDER AIR MASS WILL PREVENT FOG FROM FORMING ON THURSDAY MORNING.
THEN, EXCELLENT VFR CONDITIONS ARE FORECAST FOR THURSDAY MORNING
INTO EARLY AFTERNOON WITH ONLY A FEW CIRRUS CLOUDS AND LIGHT
NORTHWEST WINDS.
OUTLOOK...
THURSDAY NIGHT - FRIDAY MORNING...VFR.
FRIDAY - FRIDAY NIGHT...RAIN DEVELOPING EARLY IN THE DAY. MVFR AND
IFR CONDITIONS POSSIBLE WITHIN THE RAIN.
SATURDAY - SUNDAY...VFR.
SUNDAY NIGHT - MONDAY...RAIN DEVELOPING EARLY MONDAY MORNING. MVFR
OR LOWER POSSIBLE WITHIN SHOWERS.
&&
.MARINE...
THE SCA WILL BE CONTINUED FOR TONIGHT AS IS. HIGHER CONFIDENCE ON
THE NORTHERN OCEANIC WATERS THAN THE SOUTHERN WATERS AND LOWER
DELAWARE BAY. THE CHANCES FOR SCA CONDITIONS LESSEN TOWARD AND
DEFINITELY DURING THURSDAY MORNING. RIGHT NOW THE ADVISORY
EXPIRATION IS PRETTY CLOSE AND WE WILL LEAVE IT AS IS. MIGHT NEED A
SLIGHT TIME EXTENSION EAST OF DELAWARE BAY.
THE REST OF THURSDAY WILL BE SPENT WITH SUB SMALL CRAFT ADVISORY
CRITERIA AS THE HIGH PRESSURE SYSTEM GETS CLOSER.
OUTLOOK...
SUB-ADVISORY CONDITIONS ARE EXPECTED ACROSS OUR WATERS THROUGH THE
OUTLOOK PERIOD. THOUGH IT WILL BE AN ACTIVE PERIOD WITH MULTIPLE
SYSTEM PASSING THROUGH A LARGE SOUTHEAST UNITED STATES HIGH PRESSURE
SYSTEM WILL FORCE THESE SYSTEMS FAR TO OUR NORTH. THIS WILL KEEP THE
PRESSURE GRADIENT RATHER WEAK SO NOT EXPECTING WINDS AND SEAS TO
JUMP MUCH THROUGH THE PERIOD. WINDS WILL PREDOMINANTLY BE FROM THE
NORTH ON FRIDAY BEFORE SHIFTING TOWARDS THE SOUTH FOR THE WEEKEND
AND EARLY NEXT WEEK.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST THURSDAY FOR ANZ431-
450>455.
&&
$$
SYNOPSIS...HEAVENER
NEAR TERM...GIGI
SHORT TERM...GIGI
LONG TERM...HEAVENER
AVIATION...GIGI/HEAVENER
MARINE...GIGI/HEAVENER
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
1117 AM EST Wed Jan 9 2013
.UPDATED...
Clouds and fog held in longer than expected this morning so
forecast max temps have been nudged down 2-3 degrees.
.NEAR TERM [Through Rest of Today]...
The large scale split flow long wave pattern remains highly
amplified especially across Srn stream. This is highlighted in Nrn
stream by ridging over Wrn states, trough over Wrn most Great Lakes
and ridging over Ern seaboard into adjacent Atlc. Srn stream
highlighted by trough over Srn plains with closed low over NE old
Mex and Srn TX and ridging over se region into Wrn Atlc.
At surface, morning analysis shows a low near TX with cold front swd
into SE TX, and W-E warm front extending Ewd across FL Gulf Coast.
Warm front is well defined, separating a moist tropical airmass over
the Nrn Gulf from a modified continental one that has been in place
across the SE. Dew points just S of front in low to mid 60s. It was
also responsible for generating area of fog, sprinkles and drizzle
along and north of it across our land area. Inverted coastal trough
also noted just off NE FL coast.
During the rest of today, NRN stream trough will move quickly across
Great Lakes region then Ewd towards NE states in response to next
trough that begins to dig SEWD across extreme Ern PAC into West
coast. TX low will shift NEWD across rest of TX (and eventually into
Lwr MS Valley) generating widespread convection. In response,
SE ridge builds NWD. The combination of NRN trough and lifting TX
low will accelerate cold front across TX and lift warm front NWD,
However main forcing will remain well to our west in the vicinity of
cold front. This front will also signal the beginning of a warm and
humid pattern that will last into much of next week. It will also
lift coastal trough NEWD as local winds veer.
Even with all the cloudiness and some sprinkles and drizzle in place
this morning, expect enough breaks in the cloud cover into the aftn
to support temperatures in the low to mid 70s. Latest guidance and
satellite pix suggest cloud/fog erosion from E-W next few hours. So
even though 14z-15z temps running 3-5 degrees below forecast max,
they should rebound some into aftn so won`t make any updates at this
time but monitor closely. So areas in the SE Fl Big Bend could also
get into the mid-upper 70s should more breaks develop in the
overcast. The increasingly warm and moist onshore flow moving over
cooler shelf waters of Gulf will likely continue to generate
sea fog over the marine area and adjacent coast. This is evident in
the local NAM DNG5, other guidance and satellite pix. This
reflected in latest GRIDS.
&&
.SHORT TERM [Tonight Through Friday]...
With the warm front lifting northward through the area by tonight,
the region will be in an increasingly more humid airmass, which
will likely support the formation of fog/stratus after midnight.
Temperatures will also be noticeably warmer with lows around 60
degrees.
Starting Thursday the storm system across Central Texas will
begin to move north northeast around a building mid level ridge
centered over the Florida Peninsula. As this system moves into the
Great Lakes, a weak cold front will move eastward across the
Central Gulf States. The strengthening ridge will slow the
eastward progress of this system as the main upper level energy
continues to move quickly northward. As a result, only low end
rain chances are expected Thursday night into Friday as this front
eventually dissipates across the region.
As was much the case in the near term period, the short term
period will have unseasonably warm temperatures with highs in the
low to mid 70s in the western areas (due to more cloud cover) and
in the upper 70s to near 80 in the east. Overnight lows will be
muggy by January standards, generally in the upper 50s to lower 60s.
&&
.LONG TERM [Friday Night through Tuesday]...
There is good agreement between the GFS and ECMWF that deep layer
ridging will be the dominant synoptic feature over the Southeast.
This correlates to a continuation of above-average temperatures (at
least 10 to 15 degrees warmer than climatology) away from the
beaches (where SSTs remain in the upper 50s to lower 60s). The PoP
will be in the 10 to 30% range- highest along and left of a line
from Albany to Panama City as that region will be closer to the Q-G
forcing and deep layer moisture associated with a persistent
quasi-stationary frontal system.
&&
.AVIATION [through 18z Thursday]...
Updated at 950 am EST-
MVFR cigs will persist across our area (except IFR in fog and light
rain especially at KECP and KVLD until early afternoon. Then, most
cigs will lift to high MVFR, but IFR cigs may persist all day at
KECP. Widespread LIFR (or worse) Vis & cigs are likely tonight,
beginning near the coast shortly after sunset, then spreading inland
later tonight. Our forecast is a blend of the GFS/NAM MOS and latest
HRRR, with emphasis on the HRRR (which has verified well so far this
morning) through this afternoon.
&&
.MARINE...
The pressure gradient will remain tight across the marine area as a
low pressure area lifts northward across Texas and high pressure
persists over the NE gulf. Cautionary level winds will continue
possibly into Thursday before relaxing. Lighter onshore flow is
expected by the weekend as high pressure builds just off the Florida
Peninsula.
&&
.FIRE WEATHER...
Relative humidity levels will remain too moist for red flag
conditions for at least the remainder of this week.
&&
.HYDROLOGY...
No appreciable rainfall amounts are expected through the next few
days.
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 75 61 77 59 74 / 10 10 10 20 20
Panama City 71 64 74 63 73 / 20 10 10 40 20
Dothan 71 61 75 62 75 / 30 10 10 30 20
Albany 72 60 75 62 75 / 20 10 10 20 20
Valdosta 76 61 78 60 78 / 10 10 10 10 20
Cross City 79 59 79 58 76 / 10 10 10 10 20
Apalachicola 69 64 70 63 70 / 10 10 10 30 20
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
GM...None.
&&
$$
NEAR TERM...Block
SHORT TERM...Godsey
LONG TERM...Fournier
AVIATION...Block
MARINE...Block/Godsey
FIRE WEATHER...Fournier
HYDROLOGY...Godsey
AREA FORECAST DISCUSSION
NWS GAYLORD MI
117 PM EST WED JAN 9 2013
.SYNOPSIS...
ISSUED AT 405 AM EST WED JAN 9 2013
A WEAK COLD FRONT CROSSING THE AREA THIS MORNING WILL USHER IN A
BRIEF PERIOD OF WINDY AND COOLER CONDITIONS TODAY...BUT WITH LITTLE
MORE THAN A FEW LIGHT SNOW SHOWERS OR FLURRIES EXPECTED. HIGH
PRESSURE IS THEN SET TO ARRIVE WITH WARMER WEATHER FOR THURSDAY...
BEFORE LOW PRESSURE TRACKS THROUGH THE AREA INTO FRIDAY. THIS SYSTEM
WILL BRING A WIDESPREAD ROUND OF RAIN TO ALL AREAS...WITH
TEMPERATURES SOARING WELL ABOVE NORMAL. THAT WARMTH WILL STICK
AROUND INTO SATURDAY...BEFORE ANOTHER COLD FRONT BRINGS A RETURN TO
COLDER WEATHER SUNDAY AND INTO NEXT WEEK.
&&
.UPDATE...
ISSUED AT 1247 PM EST WED JAN 9 2013
THE COLD POOL FOLLOWING THE FRONT HAS FINALLY ARRIVED WITH THE
TEMPERATURES NEEDED FOR SELF-DESTRUCT SUNSHINE. 850 MB TEMPERATURES
BASED ON THE HRRR ARE NOW CREEPING DOWN TO AROUND -8C WITH THE
WIND FLOW OVER N LAKE MICHIGAN, AND MAINLY A WEST FLOW. SO MAIN
CLOUD AREAS AND LIGHT SNOW/SPRINKLE RETURNS ARE SPREADING SOUTH
AND EAST OVER THE FORECAST AREA. CLOUDS ARE AS FAR SOUTH AS M-55,
WHILE THE FLURRIES ARE ONLY TO AROUND M-72 WITH THE WEST WIND WILL
EXPECT THAT THIS WILL SPREAD TO THE EAST NORTH OF M-72 THE REST OF
THE AFTERNOON. HOWEVER, THE DRY AIR IN THE LOWER PART OF THE
ATMOSPHERE WILL LIMIT ANY MAJOR SNOW IN N LOWER, AND IS PROBABLY THE
REASON THAT WE ARE SNOWING WITH THE SFC TEMPERATURES BETWEEN 35
AND 40F THIS AFTERNOON. WILL HAVE TO SEE IF THE CLOUDS WILL
CONTINUE TO GENERATE OFF OF LAKE MICHIGAN, OR WILL THEY DRY OUT
LIKE OVER IN N WISCONSIN. WITH THE 850 MB TEMPERATURES, WILL SEE
CLOUDS FOR A FEW MORE HOURS, BEFORE THE WARMER AIR MOVES IN THIS
EVENING AND KICKS THE CLOUDS OUT OF HERE.
UPDATE ISSUED AT 1027 AM EST WED JAN 9 2013
TWEAKED THE TEMPERATURES, BOTH HOURLY AND HIGHS FOR TODAY. MAIN
PROBLEM HAS BEEN THAT WHILE WE ARE COLD ADVECTING, THE MIXING AND
SUNSHINE THAT IS BREAKING THROUGH, HAS BEEN ABLE TO OVERCOME THE
COLD ADVECTION. THE COLDER AIR IS PUSHING INTO THE REGION, BUT IT
WILL TAKE UNTIL THIS AFTERNOON BEFORE WE SEE THE TEMPERATURES
BEGIN TO FALL. THERE WAS A BRIEF LINE OF RAIN SHOWERS THAT MOVED
THROUGH E UPPER AND THE TIP OF THE MITT, BUT IT HAS SINCE FALLEN
APART AND MOVED EAST.
UPDATE ISSUED AT 654 AM EST WED JAN 9 2013
MADE SOME ADJUSTMENTS TO SKY COVER FORECAST BASED ON SATELLITE
TRENDS. THINK WE MAY SEE MORE SUN ACROSS CENTRAL LOWER COUNTIES BY
LATER THIS MORNING WITH MORE CLOUDS NORTH...AND HAVE ADJUSTED
FORECAST TO REFLECT THIS.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 405 AM EST WED JAN 9 2013
THREE MAIN FEATURES IN THE LARGE SCALE FLOW PATTERN EARLY THIS
MORNING...ONE CLOSEST TO HOME IS A SHORT WAVE TROUGH CROSSING THE
UPPER MIDWEST/UPPER GREAT LAKES WITHIN A PROGRESSIVE NORTHERN BRANCH
SPLIT FLOW PATTERN...WITH AN UPPER LOW OVER NORTHERN MEXICO WITHIN
THE SOUTHERN BRANCH. ANOTHER STRONG UPPER WAVE WAS JUST OFF THE
WEST COAST OF NORTH AMERICA. MIDNIGHT SURFACE ANALYSIS SHOWS A COLD
FRONT ASSOCIATED WITH THE UPPER MIDWEST SHORT WAVE TROUGH STRETCHING
FROM A 996MB SURFACE LOW OVER NORTHWEST ONTARIO...SOUTH ACROSS
WESTERN WISCONSIN/EASTERN IOWA. A SECONDARY FRONT WAS TRAILING BACK
ACROSS CENTRAL MANITOBA/NORTH DAKOTA. AHEAD OF THE UPPER LEVEL
WAVE...CLOUDS HAVE OVERSPREAD NORTHERN MICHIGAN. CLOUD TOPS HAVE
BEEN COOLING ACROSS WISCONSIN AHEAD OF THE 700MB TROUGH AXIS WHERE
STRONGEST UPWARD QG RESPONSE WAS OCCURRING ALONG WITH A BIT OF
SLOPED FRONTOGENETIC FORCING...AND GETTING AN INCREASE IN RADAR
RETURNS AS WELL THOUGH SURFACE BASED PRECIPITATION REPORTS HAVE BEEN
HARD TO COME BY GIVEN RELATIVE DRYNESS IN THE 850-650MB LAYER.
THERE IS A NARROW BAND OF SNOW THAT HAS DEVELOPED ACROSS NORTH
CENTRAL LOWER...AND IT IS SNOWING RATHER IMPRESSIVELY OUT THE WINDOW
AS I TYPE.
NORTHERN ONTARIO LOW HAS BEEN TRACKING EAST SINCE THIS AFTERNOON...
WITH A BROAD AREA OF 3-5MB/3H PRESSURE FALLS AHEAD OF IT. LOW IS
EXPECTED TO TRACK TOWARD THE SOUTHERN TIP OF JAMES BAY TODAY...WHICH
IN TURN WILL DRAG THE LEADING COLD FRONT ACROSS NORTHERN MICHIGAN BY
MID TO LATE MORNING. DECENT CYCLONIC PRESSURE GRADIENT ACROSS THE
UPPER LAKES TODAY...GIVING WAY TO SURFACE RIDGING TONIGHT WITH
STRONG HEIGHT RISES ALOFT (570DM 500MB HEIGHTS FORECAST BY THURSDAY
MORNING...2-3 STANDARD DEVIATIONS ABOVE THE MEAN FOR EARLY
JANUARY). MAIN FORECAST ISSUES IN THE NEAR TERM WILL FOCUS ON SHORT
WAVE PASSAGE THIS MORNING...GUSTY WEST WINDS LATER TODAY...AND LAKE
RESPONSE WITH COLD ADVECTION IN THE WAKE OF THIS MORNING`S COLD
FRONTAL PASSAGE.
WHATEVER PRECIPITATION FALLS WITH THE INITIAL PUSH OF UPWARD FORCING
WILL BE QUICK TO DEPART AS 700MB WAVE SWEEPS QUICKLY THROUGH THE
FORECAST AREA (EXTRAPOLATION FROM IR/WATER VAPOR IMAGERY SUGGESTS BY
12Z-13Z). GOOD DEAL OF LOW CLOUDS BEHIND THE FRONT THAT WILL SPREAD
INTO EASTERN UPPER AND NORTHWEST LOWER AROUND OR SHORTLY AFTER
DAYBREAK. NARROW 925MB THERMAL TROUGH FORECAST TO CROSS NORTHERN
LAKE MICHIGAN BEHIND THE FRONT...WITH TEMPERATURES OF -3 TO -4C
ENOUGH TO SUPPORT A SHALLOW LAKE RESPONSE. FORECAST SOUNDINGS SHOW
A SATURATED MIXED LAYER BELOW 875MB...AND AT TEMPERATURES MOSTLY
ABOVE -7C. IR CLOUD TOP TEMPERATURES ACROSS NORTHWEST WISCONSIN
AROUND -9 TO -11C...WITH CEILINGS IN THE VICINITY OF 1500 FEET. SO
DEFINITELY A DRIZZLE/FREEZING DRIZZLE SIGNATURE IN THERE FOR A TIME
THIS MORNING...AIDED BY LOW LEVEL CONVERGENCE AND UPSLOPE FLOW.
THIS DRIZZLE CHANCE WILL PROBABLY BE CONFINED TO JUST THE MORNING
HOURS...AS CONTINUED COLD ADVECTION WILL ALLOW CONVECTIVE BOUNDARY
LAYER TO DEEPEN ENOUGH TO SUPPORT SOME LIGHT SNOW SHOWERS/FLURRIES.
ANOTHER FEATURE TO WATCH FOR THROUGH EARLY AFTERNOON IS ANOTHER LOBE
OF MOISTURE WRAPPING SOUTHWARD INTO NORTHERN MINNESOTA ON IR
IMAGERY. THIS IS ASSOCIATED WITH ANOTHER 700MB TROUGH THAT WILL
ROTATE ACROSS LAKE SUPERIOR AND THE UPPER PENINSULA AROUND
MIDDAY...AND MAY CONTRIBUTE SOME ADDITIONAL SNOWFLAKES THROUGH EARLY
AFTERNOON. GUSTY WINDS WILL ALSO BE AN ISSUE TODAY...GIVEN STRONG
GRADIENT AND ACCOMPANYING ISALLOBARIC CONTRIBUTION...AND LOW LEVEL
COLD ADVECTION WILL HELP MIX DOWN STRONGER MOMENTUM. EXPECT WIND
GUSTS IN THE 25-35 MPH RANGE ACROSS EASTERN UPPER...AND 30-40 MPH
ACROSS NORTHERN LOWER AND POSSIBLY HIGHER ALONG THE LAKE MICHIGAN
SHORELINE COUNTIES. TEMPERATURES TODAY WILL LIKELY REMAIN STEADY OR
DROP OFF A BIT...ESPECIALLY OVER NORTHWEST LOWER WHERE TEMPERATURES
ARE AROUND 40 DEGREES TO START THE DAY AT MBL/FKS/TVC.
INCREASING HEIGHTS/DEEP LAYER ANTICYCLONIC FLOW AND ONSET OF WARM
ADVECTION WILL QUICKLY DIMINISH LINGERING LAKE CONVECTION THIS
EVENING WITH IMPRESSIVE HEIGHT RISES FOR EARLY JANUARY AS MENTIONED
ABOVE (ALMOST RIDICULOUSLY IMPRESSIVE).
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 405 AM EST WED JAN 9 2013
TRANSITION TOWARD A CLASSIC "JANUARY THAW" PATTERN IS NOW WELL
UNDERWAY ACROSS THE NORTHERN HEMISPHERE...WITH WATER VAPOR IMAGERY
SHOWING STRONG NORTH PACIFIC JET SOUTH OF THE BERING SEA COLLAPSING
INTO STRONG CLOSED LOW WEST OF THE ALEUTIANS. THIS IS ALREADY
SENDING DOWNSTREAM HEIGHTS RISING INTO THE GULF OF ALASKA...WHILE
STRONG UPPER TROUGHING IS SLIDING TOWARD THE WESTERN CONUS...FURTHER
SENDING DOWNSTREAM HEIGHTS RISING THROUGH THE PLAINS. THIS
TRANSITION WILL ONLY STRENGTHEN FURTHER WITH TIME THE NEXT FEW DAYS
AS A STRONG NEGATIVE PNA TYPE PATTERN BECOME ESTABLISHED WITH
PRONOUNCED MERIDIONAL TROUGHING OVER MUCH OF THE WESTERN
CONUS...WHILE IMPRESSIVE SOUTHEAST RIDGE SETUP BECOMES ESTABLISHED
OVER THE EASTERN HALF OF THE COUNTRY. SAID SETUP WILL FAVOR THE
OCCASIONAL EJECTION OF UPPER ENERGY FROM THE PARENT WESTERN
TROUGH...WHILE DEEPENING SOUTHWEST FLOW REGIME THROUGHOUT THE
TROPOSPHERE TRANSPORTS TREMENDOUSLY WARM AIR THROUGHOUT ALL AREAS
EAST OF THE MISSISSIPPI THROUGH AT LEAST THE FIRST PART OF THE
WEEKEND. THE PRIMARY FORECAST CONCERNS THROUGHOUT THE EXTENDED
REMAIN THE TIMING OF VARIOUS RAIN CHANCES...ALONG WITH JUST HOW WARM
TEMPS WILL GET FRIDAY/SATURDAY...AND HOW COLD IT MAY GET INTO EARLY
NEXT WEEK.
FIRST THINGS FIRST...THE DAYLIGHT HOURS OF THURSDAY CONTINUE TO LOOK
DRY AS SHORTWAVE LOW/MID LEVEL RIDGING BUILD OVERHEAD...IN ADVANCE
OF CLOSED OR NEGATIVE TILT UPPER TROUGH LIFTING THROUGH THE MID
MISSISSIPPI VALLEY. MARKED AXIS OF DRY AIR THROUGHOUT THE COLUMN
BELOW 600MB WILL EASILY PREVENT ANY PRECIP...THOUGH WE WILL SEE
INCREASING HIGH CLOUDS WITH TIME. STILL THINKING THIS COULD BE
YET ANOTHER SNEAKY WARM DAY AS LOW LEVEL WARM ADVECTION CRANKS UP
WHILE CLOUD COVER ONLY GRADUALLY THICKENS. GIVEN TRENDS THE PAST FEW
DAYS FOR TEMPS TO WAY OVER-PERFORM (BY SOME 4-8F ABOVE THE WARMEST
GUIDANCE)...HAVE NO CHOICE BUT TO BUMP NUMBERS UP ONCE AGAIN INTO
THE 38-46F RANGE...AND COULD BE WARMER PENDING ARRIVAL OF THICKER
CIRRUS.
THE MAIN SHOW STILL ARRIVES THURSDAY NIGHT INTO THE FIRST PART OF
FRIDAY...AS AFOREMENTIONED UPPER TROUGH SLIDES OVERHEAD. BEST QG
FORCING AXIS LOOKS TO SLIDE SOUTH OF THE AREA...BUT STRONG PUSH OF
DEEP LAYER WARM ADVECTION ASCENT WILL EASILY COMPENSATE...WITH SOME
40-50 KNOTS PERPENDICULAR TO THE PRESSURE SURFACES INDICATIVE OF
IMPRESSIVE LIFT...ESPECIALLY WHEN COMBINED WITH PWATS OVER AN INCH.
INTERESTINGLY...THESE MOISTURE VALUES ARE EASILY ABOVE THE 99TH
PERCENTILE FOR THIS TIME OF YEAR...AND IF THE NAM/GFS VALUES UP
AROUND 1.10 INCHES VERIFY AT 12Z FRIDAY...THIS WILL BE A NEW PWAT
RECORD FOR THE APX SITE FOR JANUARY!! SIMPLY PUT...IT`S GOING TO
RAIN AND GOING 100 PERCENT POPS WILL REMAIN. STILL SOME SMALL
POTENTIAL FOR FREEZING RAIN AT THE ONSET ACROSS THE HIGHER TERRAIN
AND INTO THE EASTERN U.P...BUT HONESTLY BECOMING LESS IMPRESSED BY
THIS POSSIBILITY GIVEN EXPECTED WARMER START THROUGH THE EVENING.
SREF PRECIP TYPE GUIDANCE AGREES WITH A STARK REDUCTION IN FZRA
PROBS THE PAST 24 HOURS...BUT CAN`T COMPLETELY RULE IT OUT...
ESPECIALLY WITH SOME COLDER ROAD SURFACES DIRECTLY AT THE GROUND.
SYNOPTIC RAIN WILL TAPER OFF QUICKLY BY MIDDAY FRIDAY WITH LOSS OF
FORCING FOR ASCENT...LEAVING IS IN NO-MAN`S LAND INTO EARLY
SATURDAY...OUT AHEAD OF A STRONGER WAVE LIFTING FROM THE CENTRAL
PLAINS THROUGH THE UPPER MIDWEST. THIS PERIOD WILL NO DOUBT CONTINUE
TO BE MILD...WITH UNOBSTRUCTED DEEP LAYER SOUTHWESTERLY FLOW KICKING
DEW POINTS WELL INTO THE 40S...WITH TEMPS FOLLOWING SUIT. BIGGEST
QUESTION IS JUST HOW MUCH STRATUS/FOG/DRIZZLE WILL BE POSSIBLE AS
WARMTH CUTS ACROSS REMAINING SNOW PACK. NORMALLY REALLY LIKE TO SEE
A WARM FRONT TO FOCUS FOG/STRATUS POTENTIAL AND WE WON`T HAVE THAT
(IT`S WAY UP INTO ONTARIO). INSTEAD WE WILL HAVE QUITE STRONG
SYNOPTIC SOUTHERLY FLOW CUTTING THROUGH THE AREA. NO DOUBT WE WILL
SEE SOME DEGREE OF LIGHT FOG AND/OR HAZE AS SNOW MELT
CONTINUES...BUT NO TOTALLY SOLD THAT WE WILL ALSO BE ENCASED IN
WIDESPREAD STRATUS THE WHOLE TIME. NAM/GFS FCST RAOBS ARE USELESS AS
THEY CAN`T WARM OVER THE SNOW PACK...BUT ECMWF/GGEM GUIDANCE (WHICH
HAVE NO TROUBLE WARMING OVER SNOW PACK) CONTINUES TO SUGGEST WE
MIGHT SHED THE LOW STUFF FOR A WHILE AS TEMPS CONTINUE TO RISE
THROUGH THE 40S...IF NOT LOW 50S. NOT REALLY A HUGE DEAL...BUT WILL
BE AN INTERESTING FORECAST TO WATCH UNFOLD.
AFTER THAT...FOCUS WILL BE ON THE EVOLUTION OF A QUITE POTENT COLD
FRONT SATURDAY INTO SATURDAY NIGHT AS THE ENTIRE WESTERN TROUGH
GRADUALLY WORKS EAST. AS MENTIONED IN THIS SPACE YESTERDAY...NOT
COMPLETELY SOLD THAT WE WILL SEE ANY ADDITIONAL SIGNIFICANT PRECIP
WITH THE ACTUAL FRONTAL APPROACH...AS FORCING WITH THE UPPER WAVE
SHEARS OUT INTO WESTERN ONTARIO WHILE DEEPER LAYER WARM ADVECTION
ASCENT AND JET HELP SLIDE THROUGH THE TENNESSEE AND OHIO VALLEYS.
CAN EASILY ENVISION A SCENARIO WHERE NORTHERN MICHIGAN IS SPLIT...
AND IN FACT...JUST ABOUT ALL THE LATEST AVAILABLE GUIDANCE SUPPORTS
THIS NOTION. TEMPS ON SATURDAY ARE TRICKY WITH THE POTENTIAL FOR A
VERY WARM DAY IN SPOTS AHEAD OF THE FRONT. 12Z ECMWF SPED UP THE
FRONTAL PASSAGE BY ABOUT 6 HOURS (MIDDAY SATURDAY)...WHILE OTHER
GUIDANCE REMAINS A BIT SLOWER. TRENDS IN THIS SETUP ALMOST ALWAYS
ARE SLOWER AS THE FLOW ALOFT PARALLELS THE SURFACE FEATURE...SO WILL
SIDE WITH YET ANOTHER VERY WARM DAY SATURDAY WITH HIGHS LIKELY
PUSHING 50 OR BETTER IN SPOTS (RECORDS ARE IN JEOPARDY IN SPOTS -
SEE BELOW FOR DETAILS)).
WHAT HAPPENS THEREAFTER IS MUCH IN QUESTION...BUT COLDER WEATHER
DOES LOOK TO MAKE AN APPEARANCE. LOTS OF JET ENERGY POURING DOWN
THE SPINE OF THE ROCKIES COMBINED WITH A STRONG SOUTHEAST RIDGE DOES
ARGUE THE WESTERN TROUGH WILL ONLY SLOWLY WORK EASTWARD...SETTING UP
A STRONG BAROCLINIC ZONE SOMEWHERE NEARBY. GUIDANCE TRENDS THE PAST
5-7 DAYS HAVE SUGGESTED THIS ZONE WILL BE EAST OF MICHIGAN...AND
SADLY FOR THE WINTER WEATHER FANS...THE LATEST GUIDANCE TRENDS ALSO
SUPPORT THIS...LEAVING THE CORE OF THE UPPER JET SQUARELY OVER
NORTHERN MICHIGAN...NEVER A GOOD PLACE TO BE IF YOU WANT WEATHER.
COULD SEE SOME PESKY LAKE EFFECT...BUT AIR MASS IS PROGGED TO BE VERY
DRY AND JUST NOT FEELING THIS AS A BIG EVENT...WITH TRENDS TENDING
TO SUPPORT A GRADUAL MODIFICATION TO THE LOW LEVEL AIR MASS WITH TIME
AS WELL. NOW...WITH THAT SAID...I`M NOT TOTALLY SOLD THAT WE WON`T
AT LEAST CATCH A LITTLE SYNOPTIC SNOW AS THE MODELS ARE NOTORIOUSLY
BAD AT PLACING SUCH STRONG THERMAL ZONES THIS FAR OUT. OF MORE
INTEREST REMAINS THE ONGOING VERY STRONG (NEAR HISTORIC VALUES BEING
OBSERVED CURRENTLY) STRATOSPHERIC WARMING EVENT THAT HAS MARCHED
FROM THE HIMALAYAS TOWARD THE ARCTIC...WITH MEDIUM RANGE MODELS
FINALLY CATCHING ONTO THE POSSIBILITY THAT SOME TRULY COLD AIR MAY
BE DRAWN DOWN INTO THE AREA AS THE POLAR VORTEX DISLODGES DOWN INTO
CANADA LATE NEXT WEEK OR JUST BEYOND. DEFINITELY SOMETHING TO WATCH
HERE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1247 PM EST WED JAN 9 2013
THERE ARE ENOUGH HOLES IN THE CIGS AND THE CIGS THEMSELVES VARY
ENOUGH THAT THERE ARE MVFR AND VFR CIGS AT THE TAF SITES. THIS
WILL CONTINUE WITH THE STRONG WINDS TO AROUND 00Z. AFTER 00Z, THE
WINDS WILL DIMINISH AS THE GRADIENT RELAXES THIS EVENING, AND THE
CLOUD COVER WILL CLEAR OUT AS THE DRIER AIR IN THE MID LEVELS
MOVES THROUGH N MICHIGAN TONIGHT. WITH THE HIGH PRESSURE MOVING
INTO THE REGION OVERNIGHT THE START OF THE DAY ON THURSDAY WILL BE
VFR.
&&
.MARINE...
ISSUED AT 405 AM EST WED JAN 9 2013
GALE WARNINGS AND SMALL CRAFT ADVISORIES ALREADY IN EFFECT THIS
MORNING FOR ANTICIPATED WINDS TODAY THROUGH THIS EVENING. ONLY
CHANGE TO HEADLINES THAT MAY BE NEEDED IS AN UPGRADE TO A GALE
WARNING FOR WHITEFISH BAY STARTING THIS AFTERNOON. A RIDGE OF HIGH
PRESSURE WILL BUILD INTO THE UPPER GREAT LAKES TONIGHT...WHICH WILL
ALLOW WINDS TO GRADUALLY RAMP DOWN AS THE NIGHT PROGRESSES WHILE
BACKING TO A MORE SOUTHERLY COMPONENT.
&&
.CLIMATE...
ISSUED AT 405 AM EST WED JAN 9 2013
BELOW IS A LOOK AT THE CURRENT RECORD HIGHS FOR BOTH FRIDAY AND
SATURDAY. AS TALKED ABOUT IN THE DISCUSSION ABOVE...SOME OF THESE
MAY WELL BE IN JEOPARDY. THE THURSDAY RECORD IN GAYLORD MAY ALSO BE
MET OR TIED IF ENOUGH SUNSHINE CAN MAKE AN APPEARANCE...CURRENTLY
SITTING AT 42 DEGREES FROM 1972. ALSO...IT IS NOT COMPLETELY
IMPOSSIBLE WE COULD APPROACH THE ALL-TIME JANUARY RECORD HIGH AT
GAYLORD...WHICH IS 53 DEGREES SET IN 1996 AND 1973.
LOCATION FRIDAY RECORD (1/11) SATURDAY RECORD (1/12)
------------------------------------------------------------
ALPENA 50 FROM 2012 49 FROM 2005
GAYLORD 47 FROM 1980 45 FROM 2005
PELLSTON 49 FROM 1975 45 FROM 2005
TRAVERSE CITY 53 FROM 2012 50 FROM 2006
HOUGHTON LAKE 50 FROM 2012 47 FROM 2005
SAULT STE MARIE 44 FROM 1980 43 FROM 1932
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...GALE WARNING UNTIL 4 PM EST THIS AFTERNOON FOR LHZ345.
GALE WARNING UNTIL 11 PM EST THIS EVENING FOR LHZ346>349.
LM...GALE WARNING UNTIL 4 PM EST THIS AFTERNOON FOR LMZ323-341-342-
344>346.
LS...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR LSZ322.
GALE WARNING UNTIL 11 PM EST THIS EVENING FOR LSZ321.
&&
$$
UPDATE...JL
SYNOPSIS...DML
SHORT TERM...JPB
LONG TERM...DML
AVIATION...JL
CLIMATE...DML
MARINE...JPB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1224 PM EST WED JAN 9 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 526 AM EST WED JAN 9 2013
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A CONTINUED PROGRESSIVE
NRN STREAM ACROSS THE NRN CONUS/SRN CANADA. SHORTWAVE TROF IS
CURRENTLY MOVING OVER THE WRN GREAT LAKES. AT THE SFC...ASSOCIATED
LOW PRES IS OVER NRN ONTARIO. DESPITE RATHER VIGOROUS LOOK OF
SHORTWAVE...VERY LITTLE PCPN HAS OCCURRED OVER THE FCST AREA
OVERNIGHT. SOME PCPN PROBABLY OCCURRED OVER LAKE SUPERIOR PER RADAR
IMAGERY. OVER UPPER MI...NARROW BAND OF PCPN APPEARED TO DEVELOP
OVER THE ERN FCST AREA BTWN 07-09Z...BUT ONLY OB TO REPORT ANY PCPN
WAS AT KERY AND THAT WAS -RA.
FOCUS TODAY SHIFTS TO WINDS AND -SHSN CHANCES IN THE WAKE OF
SHORTWAVE. WEST WINDS WILL BE INCREASING ACROSS THE KEWEENAW OVER
THE NEXT SEVERAL HRS AS CAA INCREASES INSTABILITY/BUILDS MIXING
DEPTH TOWARD THE 45-50KT LOW-LEVEL WIND MAX AT 2-4KFT. COMBINED WITH
IDEAL WNW WIND DIRECTION FOR STRONG WINDS MAKES WIND ADVY ON THE
KEWEENAW AN OBVIOUS CALL. EXPECT STRONGEST WINDS TO OCCUR MID
MORNING INTO EARLY AFTN JUST AHEAD OF APPROACHING AREA OF 5MB/3HR
PRES RISES WHICH IS NOW OVER NE ND/FAR NW MN. GUSTS OF 45-50MPH
APPEAR LIKELY DURING THAT TIME. FARTHER S...WINDS ALONG THE SHORE
TOWARD ONTONAGON/SILVER CITY WILL BE CLOSE TO 45MPH. TO THE E...
SHORELINE LOCATIONS FROM PICTURED ROCKS EASTWARD WILL ALSO SEE GUSTS
TO AROUND 45 MPH. W WINDS SHOULD KEEP THESE HIGHER GUSTS CONFINED
MOSTLY TO THE BEACHES/SHORELINE. ELSEWHERE...IT WILL BE A BREEZY DAY
WITH WIND GUSTS GENERALLY IN THE 25 TO 35 MPH RANGE.
AS FOR PCPN...850MB TEMPS FALLING BRIEFLY TO AROUND -10C WILL BE
MARGINAL FOR LES OFF LAKE SUPERIOR. HOWEVER...SINCE THERE IS A SMALL
AREA OF -SN MOVING ACROSS NRN MN ATTM...EXPECT SOME -SHSN ON THE
KEWEENAW FOR A PORTION OF THE MORNING INTO EARLY AFTN...AND OVER THE
FAR NE FCST AREA DURING THE AFTN. A COUPLE OF OBS IN NRN MN HAVE
DROPPED TO AROUND 1SM...SO THERE CERTAINLY COULD BE A BRIEF PERIOD
OF HEAVIER SHSN. WILL BE SOMETHING TO MONITOR. RIGHT NOW...IT
APPEARS SNOW ACCUMULATIONS WILL BE UNDER AN INCH.
ALTHOUGH THERE WILL BE A TREND TOWARD CLEARING SKIES AWAY FROM THE
KEWEENAW AND FAR NE FCST AREA...CAA THRU MID DAY WILL LIMIT TEMP
RISE. MAX TEMPS SHOULDN`T BE TOO MUCH HIGHER THAN CURRENT READINGS.
30S WILL BE THE RULE.
SFC HIGH PRES RIDGE QUICKLY SHIFTS ACROSS UPPER MI TONIGHT. WITH
SKIES TRENDING TOWARD MAINLY CLEAR...THERE WILL BE A WINDOW FOR
TEMPS TO FALL SHARPLY UNDER A BRIEF PERIOD OF LIGHT/CALM WIND BEFORE
RETURN FLOW DEVELOPS. INDICATED MINS AS LOW AS THE LOW TEENS IN SOME
OF THE TRADITIONAL COLD SPOTS...BUT WOULDN`T BE SURPRISED TO SEE A
FEW SPOTS FALL INTO THE SINGLE DIGITS.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 526 AM EST WED JAN 9 2013
A CONTINUED ACTIVE PATTERN WILL BE THE RULE THROUGH THE WEEKEND AS
MULTIPLE TROUGHS ARE PROGGED TO CROSS THE UPPER GREAT
LAKES...BRINGING WELL ABOVE NORMAL TEMPERATURES AND APPRECIABLE RAIN
FOR THE EAST HALF OF THE CWA.
THURSDAY AND THURSDAY NIGHT...THE UPPER GREAT LAKES AND MIDWEST WILL
BE UNDER THE INFLUENCE OF A PRONOUNCED MID-LEVEL TROUGH. THE LAYER
SHOULD BE FAIRLY DRY AND ALLOW FOR ABUNDANT SUNSHINE ACROSS THE CWA.
MEANWHILE...SOUTHERLY RETURN FLOW AHEAD OF AN APPROACHING
MID-LEVEL/SFC LOW OVER THE MID-MS VALLEY WILL BRING INCREASING WINDS
AND THIN...HIGH CIRRUS CLOUDS IN THE AFTERNOON. EXPECTATION IS THAT
MOSTLY SUNNY SKIES AND THE LOWER ALBEDO OF THE DENSE UPPER MI
FORESTS WILL RESULT IN TEMPS WELL-ABOVE NORMAL...AND EVEN SLIGHTLY
ABOVE CURRENT GUIDANCE. KEPT FORECAST VERY SIMILAR TO PREVIOUS
SHIFT...WITH UPPER 30S ACROSS MUCH OF THE INTERIOR AND LOW 40S FOR
DOWNSLOPE LOCATIONS ALONG LAKE SUPERIOR. SOME LOCATIONS WILL
APPROACH RECORD HIGHS IF DOWNSLOPE INFLUENCE IS STRONGER THAN
ANTICIPATED.
NOW ONTO THE SYSTEM TAKING AIM ON THE AREA THURSDAY NIGHT. A COMPACT
MID-LEVEL CUTOFF LOW NEAR THE GREAT BEND OF TEXAS IS BEGINNING ITS
TURN NORTHEASTWARD AND IS SET TO REACH THE MID-MS VALLEY BY LATE
THURSDAY NIGHT. MODEL AGREEMENT ON THIS SYSTEM HAS BECOME VERY GOOD
WITH THE EXCEPTION OF THE GFS...WHICH HAS BEEN TRENDING SLOWER. WILL
STICK WITH THE MORE CONSISTENT ECMWF/GEM SOLUTION.
THOUGH THE MAIN MID-LEVEL FORCING WITH THE SHORTWAVE WILL PASS JUST
TO THE SOUTHEAST OF THE CWA...DECENT ISENTROPIC LIFT ON THE 295-305K
SURFACES AND CONSIDERABLE LOW-LEVEL MOISTURE TRANSPORT ON THE NOSE
OF A 60KT H8 JET WILL SUPPORT MODERATE RAIN OVER THE EAST HALF OF
THE CWA. MOISTURE CONTENT OF THE COLUMN WILL BE AN IMPRESSIVE
1.1"/450 PERCENT OF NORMAL. GIVEN THE SET-UP AND HIGH WATER CONTENT
FOR JANUARY...HAVE CONTINUED THE TREND OF BUMPING UP POPS TO
WIDESPREAD RAIN ACROSS THE EASTERN TWO-THIRDS OF THE CWA BEGINNING
LATE THURSDAY EVENING. HELD OFF POPS FOR ALL BUT THE SOUTH-CENTRAL
CWA UNTIL THIS TIME. STORM TOTAL QPF OF A HALF INCH OR MORE FOR THE
EAST HALF SEEMS REASONABLE ATTM.
AS FOR PRECIP TYPE...TEMPERATURES ACROSS THE INTERIOR WEST AND
CENTRAL MAY FALL BELOW FREEZING IN THE EVENING BEFORE THICKER CLOUDS
AND WAA TAKE CONTROL AND WARM TEMPS BACK ABOVE FREEZING. INITIAL
RAIN WILL BE FALLING INTO QUITE A DRY LAYER...WITH SFC WET-BULB
TEMPS JUST UNDER FREEZING. HOWEVER...GIVEN WARM HIGHS AND
CONSIDERABLE SUNSHINE THURSDAY...A NARROW WINDOW OF BELOW FREEING
TEMPS...AND WARM RAIN FROM A 6 TO 8C WARM LAYER ABOVE THE SFC...ONLY
PUT IN A SLIGHT CHANCE OF FREEZING RAIN MAINLY INTERIOR CENTRAL. NOT
REALLY EXPECTING ANY ICING...BUT DID WANT TO PUT A SMALL MENTION IN
THERE.
FRIDAY THROUGH FRIDAY NIGHT...PRECIP WILL CONTINUE ACROSS THE EAST
HALF FRIDAY MORNING AS THE INFLUX OF MOISTURE CONTINUES OVER THE
AREA. A SECONDARY DEEP TROUGH MOVING INTO THE ROCKIES FRIDAY
AFTERNOON WILL BEGIN TO LIFT NORTHEASTWARD BY FRIDAY EVENING. IN
COMBINATION WITH THE LEFT EXIT OF A 140KT UPPER JET OVER THE
UPPER-MS VALLEY...A SFC LOW WILL QUICKLY FORM OVER MN FRIDAY NIGHT.
THERE SHOULD BE A LAPSE IN PRECIP FOR ALL BUT THE WESTERN CWA FRIDAY
NIGHT AS PLENTY OF DRY AIR IS DRAWN INTO THE REGION AHEAD OF THE
TROUGH/SFC LOW. SOME DRIZZLE IS POSSIBLE WITHIN A THICK LOW-LEVEL
STRATUS DECK WHERE RAIN SHOWERS MAY NOT BE AS PREVALENT CENTRAL AND
EAST. ALSO HAVE AREAS OF FOG IN THE FORECAST GIVEN RELATIVELY
WARM/MOIST AIR FLOWING OVER MELTING SNOW.
SATURDAY...AS THE SURFACE LOW TRACKS OVER LAKE SUPERIOR LATE FRIDAY
NIGHT INTO SATURDAY...IT WILL DRAW DOWN COLDER AIR FROM CANADA AND
SWEEP A COLD FRONT ACROSS THE CWA. HIGHS WILL LIKELY BE EARLY IN THE
DAY AS TEMPERATURES WILL QUICKLY FALL AT MOST LOCATIONS BY THE
AFTERNOON. EXPECT ANY RAIN SHOWERS TO TRANSITION TO SNOW SHOWERS
FROM WEST TO EAST THROUGHOUT THE DAY. ONLY MINOR ACCUMULATIONS ARE
EXPECTED AS MID/UPPER LEVEL SUPPORT WILL BE NORTH OF THE CWA AND
DECENT H5 Q-VECTOR DIVERGENCE WILL BE PASSING OVER THE CWA.
SATURDAY NIGHT THROUGH TUESDAY...DID NOT MAKE MANY CHANGES PAST THIS
POINT. LAKE EFFECT SNOW LOOKS LIKELY FOR THE KEWEENAW AND FAR
NORTHEAST SATURDAY NIGHT THROUGH SUNDAY WITH WNW WINDS. A CORE OF
-17 TO -19C AIR GETS WRAPPED AROUND THE DEPARTING LOW AND CROSSES
LAKE SUPERIOR SATURDAY NIGHT. INVERSION HEIGHTS SHOULD STAY BETWEEN
4-5 KFT THROUGH MUCH OF SUNDAY UNDERNEATH SUBSIDENCE BEHIND THE
DEPARTING TROUGH. THOSE HEIGHTS THEN FALL UNDER 3 KFT AND DRY AIR
ADVECTS INTO THE REGION FROM THE SW SUNDAY NIGHT...THEREBY
DECREASING LES COVERAGE BY MONDAY. TEMPERATURES THEN REMAIN AROUND
SEASONAL NORMS TO START NEXT WEEK WITH MINIMAL PRECIP CHANCES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1223 PM EST WED JAN 9 2013
A STRONG PRESSURE GRADIENT BETWEEN A LOW NEAR HUDSON BAY AND A HIGH
IN MINNESOTA WILL CONTINUE TO PRODUCE GUSTY WINDS THIS AFTERNOON AT
ALL TAF SITES. THE STRONGEST WINDS WILL CONTINUE TO BE AT
KCMX...WHERE GUSTS TO 45-55MPH HAVE BEEN OCCURRING. EXPECT THE WINDS
TO DECREASE LATER THIS AFTERNOON AS THE HIGH PRESSURE RIDGE SHIFTS
OVER THE AREA. OTHER THAN LINGERING LAKE EFFECT SNOW AND CLOUDS AT
THIS EVENING...DECREASING CLOUDS ARE IN STORE FOR ALL SITES OVER THE
NEXT 3-9HOURS. THE HIGH PRESSURE RIDGE WILL THEN PRODUCE VFR
CONDITIONS TONIGHT INTO THURSDAY.
ONE FINAL ITEM OF NOTE...AN INCREASING LOW LEVEL JET ABOVE THE
INVERSION IS EXPECTED TOMORROW MORNING...UP TO 45-50KTS AROUND 1KFT
ABOVE THE SURFACE. OPTED TO ADD IN A MENTION OF LLWS AT KIWD/KCMX
SINCE THE INVERSION SHOULD KEEP SURFACE WINDS TOMORROW MORNING
AROUND 10KTS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 526 AM EST WED JAN 9 2013
IN THE WAKE OF COLD FRONT PASSING ACROSS LAKE SUPERIOR THIS
MORNING...EXPECT W GALES OF 35-45KT TODAY. HIGH OBS PLATFORMS MAY
HAVE A COUPLE OF HRS OF GUSTS TO STORM FORCE JUST AHEAD OF 5MB/3HR
PRES RISES THAT WILL SHIFT ACROSS THE AREA TODAY. WINDS WILL QUICKLY
DIMINISH TO UNDER 20KT W TO E TONIGHT AS SFC HIGH PRES RIDGE MOVES
ACROSS LAKE SUPERIOR. INCREASING SOUTHERLY WINDS TO 20 TO 30 KNOTS
AHEAD OF AN APPROACHING LOW PRESSURE IN THE MID-MISSISSIPPI VALLEY
WILL AFFECT MAINLY THE EAST HALF OF LAKE SUPERIOR THURSDAY AND
THURSDAY NIGHT. LIGHT SOUTHERLY WINDS WILL THEN TAKE HOLD FRIDAY
BEFORE A COLD FRONT SWEEPS ACROSS THE LAKE FROM WEST TO EAST ON
SATURDAY. WESTERLY WINDS OF 25 TO 30 KNOTS WILL DEVELOP BY SATURDAY
AFTERNOON AND CONTINUE INTO EARLY SATURDAY EVENING. A FEW GALES TO 35
KNOTS WILL BE POSSIBLE ACROSS THE EAST HALF OF THE LAKE LATE SATURDAY
AFTERNOON. THE PATTERN BECOMES QUITE BENIGN BY SUNDAY...WITH MAINLY
WESTERLY WINDS UNDER 20 KNOTS THROUGH THE REMAINDER OF THE PERIOD.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR MIZ001-003.
LAKE SUPERIOR...
GALE WARNING UNTIL 10 PM EST THIS EVENING FOR LSZ249>251-266-267.
GALE WARNING UNTIL 7 PM EST THIS EVENING FOR LSZ243>248-264-265.
GALE WARNING UNTIL 4 PM EST /3 PM CST/ THIS AFTERNOON FOR LSZ162-
240>242-263.
LAKE MICHIGAN...
GALE WARNING UNTIL 4 PM EST THIS AFTERNOON FOR LMZ221-248-250.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...TK
AVIATION...SRF
MARINE...ROLFSON/TK
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1138 AM CST WED JAN 9 2013
.UPDATE...FOR 18Z AVIATION DISCUSSION BELOW
&&
.DISCUSSION.../ISSUED 437 AM CST WED JAN 9 2013/
MAIN FORECAST CONCERN FOR THIS PERIOD WAS IN THE THURSDAY THROUGH
SATURDAY TIME FRAME AS AN UNCHARACTERISTICALLY WARM AND MOIST
SYSTEM FOR JANUARY STANDARDS IMPACTS THE AREA...WITH WHAT LOOKS
TO BE PRIMARILY RAIN THURSDAY THROUGH FRIDAY...WITH A TRANSITION
BACK TO SNOW FRIDAY EVENING.
VERY MILD CONDITIONS TO START THE DAY...WITH MANY AREAS STILL IN
THE 30S AT 3AM AS THE AREA SITS OUT AHEAD OF PACIFIC COLD FRONT
CURRENTLY MOVING ACROSS THE DAKOTAS. CURRENT HIGHS FOR TODAY ONLY 5
TO 10 DEGS HIGHER THAN CURRENT TEMPS...SO COULD END UP BEING A BIT
WARMER THAN CURRENTLY FORECAST...ESPECIALLY EAST OF THE BUFFALO
RIDGE IN SW MN...WHERE TEMPS ARE A DEGREE OR TWO ON EITHER SIDE
OF 35 AT THE MOMENT. ALSO GETTING SOME STRONG WINDS IN THE WRN CWA
THIS MORNING...WITH SPEEDS UP NEAR ADVY LEVELS...WITH SOME
SUSTAINED WINDS IN THE AXN/MOX AREA NEAR 30 MPH...WITH GUSTS
APPROACHING 40. FORTUNATELY...NOT EXPECTING THINGS TO GET ANY
WORSE THAN WHAT WE HAVE ALREADY SEEN SINCE MAIN PUSH OF PRESSURE
RISES WILL BE GOING NORTH OF HERE...ALONG WITH A STRONG INVERSION
MAKING IT DIFFICULT TO MIX MUCH WIND TO THE GROUND. THIS SECOND
PART IS FORTUNATE...AS RAP SHOWS 1K FT WINDS UP AT 40 KTS...BUT
THE INVERSION WILL KEEP THOSE UP THERE...MEANING A WIND ADVY IS
UNNECESSARY FOR TODAY.
THE WEATHER LOOKS QUIET TODAY THROUGH TONIGHT...BUT STILL LOOKS
TO TURN SOUTH IN A HURRY THURSDAY AFTERNOON. CUT OFF LOW WITH A
WALL OF WATER OVER TX THIS MORNING WILL SLOWLY DRIFT NORTH TODAY
AS A SHARP THROUGH MOVES ONSHORE OUT WEST. AS THE MAIN TROUGH
WORKS ACROSS THE ROCKIES THURSDAY...IT WILL PICK UP THE CLOSED LOW
A QUICKLY SEND IT AND ITS RAIN NORTH TOWARD THE GREAT LAKES. AS
WITH PREVIOUS FORECAST...FAVORED A GEM/ECMWF BLEND FOR TIMING
PRECIP IN THURSDAY/THURSDAY NIGHT AS THIS IS A GOOD COMPROMISE
BETWEEN THE NAM...WHICH IS ABOUT 6 HOURS FASTER AND THE GFS WHICH
IS 6 HOURS SLOWER THAN THE GEM/ECMWF. HOWEVER...WORRIED NAM MAY BE
RIGHT WITH THE FASTER TIMING. THIS IS BECAUSE A QUICK LOOK AT H85
MOISTURE TRANSPORT ON THE ECMWF SHOWS THAT IT AGREES MUCH MORE
WITH THE TIMING INDICATED BY THE NAM QPF THAN ITS OWN...SO WOULD
NOT BE SURPRISED IF WE NEED TO START SPEEDING UP THE SPREAD OF
POPS NORTH THURSDAY AFTERNOON.
BIG ISSUE WITH PRECIP THURSDAY NIGHT THROUGH FRIDAY IS ALL MODELS
ARE SHOWING THE MPX CWA GETTING DRY SLOTTED...WITH MOISTURE
REMAINING RATHER SHALLOW AFTER THE INITIAL PUSH OF PRECIP THURSDAY
AFTERNOON. DID FAVOR QPF THU/THU NIGHT TOWARD THE HIGHER HPC
NUMBERS AS BOTH THE NAM AND GFS SHOW PWATS WITH THIS INITIAL SURGE
OF PRECIP INCREASE TO AND EVEN EXCEEDING 1 INCH. THIS IS A GOOD
400-500 PERCENT OF NORMAL. THE HIGHEST PWAT EVER OBSERVED AT
MPX/STC IN JANUARY IS 0.92...SO WHAT WE WILL BE SEEING THURSDAY
WILL BE QUITE RARE INDEED. BASED ON THE HIGH PWAT...LIKE THE
HIGHER HPC NUMBERS...THOUGH HEAVIEST RAIN WILL BE DIRECTED MORE
TOWARD GREEN BAY...WHERE BEST LLJ AND MOISTURE TRANSPORT WILL BE
DIRECTED. DRY SLOTTING THURSDAY NIGHT THROUGH FRIDAY RESULTS IN
SOUNDINGS LACKING ANY ICE CRYSTALS...WITH DRIZZLE LOOKING TO BE THE
PRIMARY PRECIP SEEN IN THIS PERIOD.
AS FOR P-TYPE...FAVORED TEMPERATURE FORECAST THU-FRI TOWARD THE
GEM/ECMWF AS WELL...WHICH RESULTS IN A MUCH WARMER SCENARIO. BY
THE TIME PRECIP GETS HERE THURSDAY AFTERNOON...CURRENTLY HAVE THE
ENTIRE CWA ABV FREEZING...SO KEPT PRECIP MENTION THURSDAY AS ONLY
RAIN. FOR THURSDAY NIGHT...MAY BE QUESTIONABLE IF LOWS ANYWHERE IN
THE MPX CWA DROP BELOW FREEZING...WHICH MEANS RAIN WILL LIKELY BE
THE PRIMARY P-TYPE RIGHT THROUGH THURSDAY NIGHT. ON
FRIDAY...MODELS BEGINNING TO REALLY TIGHTEN UP BAROCLINIC ZONE
THAT WILL BE JUST WEST/NW OF THE MPX AREA...WITH WINDS BACKING TO
THE SE. THIS SHOULD ALLOW 40 DEG TEMPERATURES TO SNEAK INTO ERN
AREAS FRIDAY. THIS FRONT DOES NOT LOOK TO START WORKING ACROSS
THE MPX CWA UNTIL FRIDAY NIGHT BASED ON AN ECMWF/GFS/NAM BLEND AS
A RAPIDLY DEEPENING SFC LOW MOVES UP FROM NEAR SIOUX FALLS UP TO
THE ARROWHEAD. NO OTHER WAY TO EXPLAIN THE CAA BEHIND THIS FRONT
FRIDAY NIGHT OTHER THAN AS INTENSE...WITH WIND ADVY STRENGTH WINDS
LOOKING LIKELY AND TEMPERATURES LIKELY DROPPING 20 DEGREES OR MORE
WITHIN AN HOUR OR TWO. THIS WILL QUICKLY TURN ANY PRECIP OVER TO
SNOW...THOUGH TRACK OF THE LOW WILL KEEP PRIMARY BAND OF SNOW
ACROSS NW MN.
LOOKING AT POTENTIAL HEADLINES...THERE WILL BE THE POSSIBILITY FOR
TWO WITH THIS SYSTEM...A WINTER WEATHER AND WIND ADVY. AT THE
MOMENT...THE MOST LIKELY PLACE THAT MAY NEED A WINTER WX ADVY IS
THE FAR NW CWA. THIS IS WHERE THE HIGHEST POTENTIAL FOR SEEING
FZRA WILL BE THURSDAY NIGHT...FOLLOWED BY THE POTENTIAL FOR A FEW
INCHES OF SNOW FRIDAY NIGHT INTO SATURDAY DEPENDING ON HOW FAR SE
THE DEFORMATION PRECIP BAND SETS UP. AS FOR THE WIND ADVY...FRIDAY
NIGHT IS LOOKING QUITE BREEZY...ESPECIALLY ON THE ECMWF...WHICH
DEVELOPS SUSTAINED WINDS IN WRN MN IN EXCESS OF 30 MPH...WITH
GUSTS OVER 40 MPH IN RESPONSE TO IT SENDING A 990 LOW OVER TO THE
WEST END OF LAKE SUPERIOR AS A 1030 MB HIGH MOVES INTO THE BLACK
HILLS.
AS FOR THE REST OF THE FORECAST...IT IS LOOKING COOLER...ESPECIALLY
SATURDAY THROUGH MONDAY...WHEN BELOW ZERO LOWS WILL RETURN WITH
HIGHS IN THE SINGLE DIGITS AND TEENS...THOUGH WE COULD GET WARMER
THAN THAT AS WARM TEMPS THURSDAY/FRIDAY WILL LIKELY PUNCH A LOT OF
HOLES IN THE SNOWPACK OUTSIDE OF THE NW CWA...WHICH WILL LIKELY
GET SOME SNOW FRIDAY NIGHT. BY THE MIDDLE OF THE WEEK...BOTH THE
GFS/ECMWF SHOW TEMPERATURES MODERATING OUT AHEAD OF CLIPPER COMING
DOWN TUESDAY NIGHT/WEDNESDAY. ALSO INTERESTING IS THAT AS NEXT
WEEK GROWS CLOSER...THE GFS/ECMWF CONTINUE TO BACK OFF ON THE
EXTENT TO WHICH THE ARCTIC AIR MAKES IN INTO THE US...WITH EACH
NEW RUN SEEMING TO KEEP IT FURTHER AND FURTHER NORTH...SO THAT WILL
BE SOMETHING TO WATCH. AS FOR WEATHER...AFTER THURSDAY NIGHT
THROUGH SATURDAY IT LOOKS DRY.
&&
.AVIATION.../18Z TAF ISSUANCE/
VFR CONDITIONS WITH CLEAR SKIES WILL PREVAIL THROUGH THURSDAY
MORNING...ALTHOUGH WIND SHEAR IS EXPECTED TO IMPACT SEVERAL SITES
OVER WEST CENTRAL AND CENTRAL MN TONIGHT THROUGH THURSDAY MORNING.
IN THE MEANTIME...SURFACE WINDS WILL CONTINUE SUBSIDING BELOW 10
KTS FROM WEST TO EAST AND BACKING THIS AFTERNOON AS RIDGING BUILDS
INTO THE AREA. AROUND/AFTER 06Z TONIGHT...A LOW LEVEL JET NOSES
INTO WESTERN/CENTRAL MN...WHEN THE NAM INDICATES 0-1KM AGL SHEAR
MAGNITUDE AROUND 50 KTS DEVELOPING. HAVE INCLUDED LLVL WIND SHEAR
IN THE KAXN/KRWF/KSTC TAFS AROUND 1500 FT TONIGHT UNTIL LATE
THURSDAY MORNING. ATTENTION THEN TURNS TO INCREASING CLOUD COVER AND
PRECIP CHANCES WITH THE NEXT SYSTEM. SHOULD SEE MID/HIGH CLOUDS ON
THE INCREASE AFTER 18Z THURSDAY...WITH SUB-VFR CONDITIONS EXPECTED
TO HOLD OFF UNTIL 23Z. SHOULD THEN SEE RAPID DETERIORATION IN
CONDITIONS AFTER 00Z FRIDAY IN CONJUNCTION WITH THE ONSET OF -RA
AND DZ.
KMSP...
HIGH CONFIDENCE IN VFR CONDITIONS THROUGH 21Z THURSDAY...AND THEN
DETERIORATING CONDITIONS TO IFR CIGS/VSBYS EXPECTED AROUND/AFTER
23Z THURSDAY AS LIGHT PRECIP BEGINS. WINDS AROUND 270-290 DEGREES
TO START THE PERIOD...BACKING TO AROUND 190-200 DEGREES BY
00Z...THEN FURTHER BACKING TO AROUND 150 DEGREES FROM 03Z THROUGH
THE REMAINDER OF THE PERIOD. SPEEDS INITIALLY AROUND 12-15
KTS...THEN RANGING BETWEEN 6 AND 12 KTS AFTER 21Z. WHILE THE MAIN
CORE OF THE LOW LEVEL JET IS EXPECTED WEST/NORTHWEST OF
KMSP...COULD SEE 1500-2000FT WINDS OF 45-50 KTS AFTER 06Z.
/OUTLOOK FOR KMSP/
THU NIGHT...IFR CIGS/VSBYS WITH RAIN EARLY...THEN LIFR CONDITIONS
POSSIBLE IN DZ AND FG. WINDS SE AT 5-10 KTS.
FRI...IFR WITH DZ AND FG. LIFR POSSIBLE. WINDS SE AT 5-10 KTS.
SAT...MVFR WITH -SHSN POSSIBLE. COLD FRONT PASSAGE EARLY. WINDS W
AT 20G30KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
BORGHOFF/LS
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1137 AM CST WED JAN 9 2013
.UPDATE...FOR AVIATION.
&&
.AVIATION...
18Z TAFS...WITH THE INFLUENCE OF A NORTHERN STREAM WAVE MOVING
EAST...RAINFALL WILL BE TAPERING OFF SOME THIS AFTERNOON. RAIN
WILL RAMP UP AGAIN TONIGHT AS A WARM FRONT MOVES IN FROM THE
SOUTH. PLENTY OF LOW LEVEL MOISTURE WILL REMAIN OVER THE AREA.
FOR CKV AND BNA...A COUPLE HOURS YET OF LINGERING SHOWERS AND
INTERMITTENT IFR CIGS...THEN CONDITIONS WILL IMPROVE TO MVFR WITH
SOME PERIODS OF VFR LATER TODAY. CONDITIONS WILL RAPIDLY
DETERIORATE TO IFR OVERNIGHT AS THE WARM FRONT APPROACHES.
CSV WILL SEE SOME IMPROVEMENT IN VSBY THIS AFTERNOON...BUT CIGS WILL
REMAIN LOW. RAIN AND LOWER CIGS/VSBYS WILL MOVE IN AGAIN TONIGHT.
13
&&
.PREV DISCUSSION... /ISSUED 1007 AM CST WED JAN 9 2013/
UPDATE...
12Z OHX SOUNDING DEPICTS A VERY MOIST ATMOSPHERE WITH A PWAT OF
1.32 INCHES...WHICH IS ABOVE THE 99TH PERCENTILE PWAT FOR JANUARY
AND NOT FAR FROM THE TYPICALLY OBSERVED MAXIMUM FOR THE MONTH.
LATEST RADAR IMAGERY SHOWS LIGHT TO MODERATE RAIN HAS OVERSPREAD
NEARLY THE ENTIRE CWA...WITH THE HEAVIEST RAIN AXIS FROM
LAWRENCEBURG TO LA VERGNE TO CELINA. RADAR ESTIMATES AND RAIN
GAUGE REPORTS INDICATE MANY LOCATIONS ALONG AND EITHER SIDE OF
THIS AXIS HAVE ALREADY SEEN OVER A HALF INCH OF RAIN TODAY. 12Z
GFS/NAM/ECMWF GUIDANCE SUGGESTS RAIN WILL TAPER OFF CONSIDERABLY
THIS AFTERNOON...BUT MOSAIC RADAR IMAGERY SHOWING PLUME OF
MOISTURE AND RAIN EXTENDING HUNDREDS OF MILES TO THE SOUTHWEST
INTO LOUISIANA AND THE WESTERN GULF OF MEXICO ARGUES RAIN WILL
CONTINUE THROUGH MUCH OF THE DAY. RECENT HRRR RUNS AGREE WITH
THIS AND DEPICT AREAS OF LIGHT TO MODERATE RAIN CONTINUING INTO
THE EVENING. WILL BUMP UP POPS INTO THE AFTERNOON HOURS BASED ON
RADAR TRENDS AND HRRR BEFORE DECREASING RAIN CHANCES LATER TODAY.
APPEARS WIDESPREAD CLOUDS AND PRECIPITATION MAY KEEP HIGH TEMPS
JUST UNDER CURRENT FORECAST AND LOWERED TEMPS A TAD IN SOME AREAS.
REST OF FORECAST LOOKS TO BE ON TRACK AND NO OTHER CHANGES WERE
MADE.
SS
PREV DISCUSSION... /ISSUED 711 AM CST WED JAN 9 2013/
UPDATE...
INCREASED POPS BEFORE NOON FOR ALL OF MIDDLE TENNESSEE. ALSO
INCREASED QPF TODAY BASED ON RAINFALL REPORTS OF 0.25 TO HALF AN
INCH THIS MORNING...WHICH AGREES WITH RADAR ESTIMATES. AS AN UPPER
LOW OVER EASTERN CANADA MOVES OFF TO THE EAST AND THE TEXAS LOW
MOVES NORTH THIS MOISTURE AXIS WILL BECOME MORE EAST TO WEST
ORIENTED THIS MORNING CAUSING A DECREASE IN POPS IN THE NORTHERN
HALF OF THE MID STATE AND KEEPING LIKELY POPS SOUTH OF I-40 THIS
AFTERNOON.
11
PREV DISCUSSION... /ISSUED 448 AM CST WED JAN 9 2013/
DISCUSSION...
RADAR INDICATES WIDESPREAD SHOWERS ENTERING THE AREA FROM THE
SOUTHWEST THIS MORNING WITH SCATTERED SHOWERS DEVELOPING ACROSS
MOST OF MIDDLE TN. EXPECT THAT RAINFALL WILL CONTINUE THROUGHOUT
THE DAY BEING MORE WIDESPREAD IN THE SOUTHERN AND WESTERN
COUNTIES. THIS SURGE OF MOISTURE IS BEING URGED UPWARD BY A CUTOFF
LOW OVER TEXAS THAT WILL GRADUALLY MOVE NORTH INTO OKLAHOMA TODAY.
WEDNESDAY NIGHT...HEAVIEST PRECIP IS EXPECTED TO REMAIN IN THE
WESTERN HALF OF MIDDLE TN. OVERCAST SKIES WILL SETTLE IN TODAY AND
TONIGHT KEEPING LOW TEMPERATURES MILD...AROUND 50 DEGREES.
THE LOW IS EXPECTED TO REMAIN WELL TO OUR WEST...MOVING FROM
OKLAHOMA TO THE MID MISSISSIPPI VALLEY ON THURSDAY. THEREFORE, POPS WILL
REMAIN HIGH IN THE WEST ON THURSDAY WITH ONLY CHANCE POPS AROUND
THE PLATEAU. THUNDERSTORM CHANCES REMAIN HIGHEST IN THE WEST AS
WELL AND ARE INTRODUCED INTO THE FORECAST AS EARLY AS 06Z
THURSDAY. A WARM FRONT IS EXPECTED TO LIFT NORTH THROUGH THE
MID STATE SOMETIME DURING THE MORNING HOURS ON THURSDAY ENCOURAGING
MORE THUNDERSTORM DEVELOPMENT ALONG WITH HEAVY SHOWERS.
SHOWERS AND THUNDERSTORMS WILL BE LESS LIKELY EARLY FRIDAY
MORNING PRIOR TO THE MAIN MOISTURE AXIS PUSHING THROUGH. AN
ENHANCED LOW LEVEL JET AND THE PASSAGE OF ANOTHER BAND OF DEEP
MOISTURE LATER IN THE MORNING COULD INFLUENCE SOME STORMS TO
BECOME STRONG...WITH GUSTY WINDS, HEAVY DOWNPOURS, AND SMALL
HAIL. WIDESPREAD RAINFALL AMOUNTS OF 1 INCH ARE LIKELY WITH
LOCALIZED AMOUNTS AROUND 2 TO 3 INCHES POSSIBLE AT THE END OF THE
SHORT TERM.
FRIDAY AFTERNOON AND EVENING CLOUDS ARE EXPECTED TO THIN OUT, BUT
NOT DISAPPEAR AS THE LOW PRESSURE SYSTEM MOVES OFF TO THE
NORTHEAST. HIGH TEMPERATURES ON FRIDAY COULD REACH 65 DEGREES
ALONG THE PLATEAU AND NEAR 70 ELSEWHERE...VERY CLOSE TO THE DAILY
RECORD OF 72 IN NASHVILLE AND 64 IN CROSSVILLE...HOWEVER THIS IS
VERY DEPENDENT ON THE AMOUNT OF CLOUD COVER AND HOW QUICKLY IT
PARTIALLY CLEARS OUT AFTER THE BAND OF MOISTURE.
THIS WEEKEND QUICKLY BECOMES A RAINY ONE WITH THE NEXT SYSTEM
PUSHING INTO THE MID STATE SATURDAY MORNING AND LINGERING THROUGH
THE END OF THE FORECAST PERIOD. MODELS AGREE THAT A BAND OF DEEP
MOISTURE WILL SET UP ACROSS THE TENNESSEE AND OHIO VALLEYS AS A
STRONG RIDGE STAYS IN PLACE OFF THE EAST COAST. STRONG UPPER LEVEL
WINDS FROM THE SOUTHWEST WILL BRING DEEP SUBTROPICAL MOISTURE INTO
THE SOUTHEAST. PWAT VALUES STILL LOOK EXCEPTIONALLY HIGH FOR THIS
TIME OF THE YEAR..AROUND 1.5 INCHES...THROUGH AT LEAST MONDAY NIGHT.
THE DIFFERENCES IN THE BOUNDARY LOCATION WILL DETERMINE WHERE THE
HEAVIEST RAINFALL TOTALS DEVELOP AND ALSO THE TEMPERATURES IN THE
LONG TERM. COLDER AIR...NEAR SEASONAL NORMS...WILL FILE IN BEHIND
THE BOUNDARY BY MID WEEK NEXT WEEK.
11
&&
.OHX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1007 AM CST WED JAN 9 2013
.UPDATE...
12Z OHX SOUNDING DEPICTS A VERY MOIST ATMOSPHERE WITH A PWAT OF
1.32 INCHES...WHICH IS ABOVE THE 99TH PERCENTILE PWAT FOR JANUARY
AND NOT FAR FROM THE TYPICALLY OBSERVED MAXIMUM FOR THE MONTH.
LATEST RADAR IMAGERY SHOWS LIGHT TO MODERATE RAIN HAS OVERSPREAD
NEARLY THE ENTIRE CWA...WITH THE HEAVIEST RAIN AXIS FROM
LAWRENCEBURG TO LA VERGNE TO CELINA. RADAR ESTIMATES AND RAIN
GAUGE REPORTS INDICATE MANY LOCATIONS ALONG AND EITHER SIDE OF
THIS AXIS HAVE ALREADY SEEN OVER A HALF INCH OF RAIN TODAY. 12Z
GFS/NAM/ECMWF GUIDANCE SUGGESTS RAIN WILL TAPER OFF CONSIDERABLY
THIS AFTERNOON...BUT MOSAIC RADAR IMAGERY SHOWING PLUME OF
MOISTURE AND RAIN EXTENDING HUNDREDS OF MILES TO THE SOUTHWEST
INTO LOUISIANA AND THE WESTERN GULF OF MEXICO ARGUES RAIN WILL
CONTINUE THROUGH MUCH OF THE DAY. RECENT HRRR RUNS AGREE WITH
THIS AND DEPICT AREAS OF LIGHT TO MODERATE RAIN CONTINUING INTO
THE EVENING. WILL BUMP UP POPS INTO THE AFTERNOON HOURS BASED ON
RADAR TRENDS AND HRRR BEFORE DECREASING RAIN CHANCES LATER TODAY.
APPEARS WIDESPREAD CLOUDS AND PRECIPITATION MAY KEEP HIGH TEMPS
JUST UNDER CURRENT FORECAST AND LOWERED TEMPS A TAD IN SOME AREAS.
REST OF FORECAST LOOKS TO BE ON TRACK AND NO OTHER CHANGES WERE
MADE.
&&
.PREV DISCUSSION... /ISSUED 711 AM CST WED JAN 9 2013/
UPDATE...
INCREASED POPS BEFORE NOON FOR ALL OF MIDDLE TENNESSEE. ALSO
INCREASED QPF TODAY BASED ON RAINFALL REPORTS OF 0.25 TO HALF AN
INCH THIS MORNING...WHICH AGREES WITH RADAR ESTIMATES. AS AN UPPER
LOW OVER EASTERN CANADA MOVES OFF TO THE EAST AND THE TEXAS LOW
MOVES NORTH THIS MOISTURE AXIS WILL BECOME MORE EAST TO WEST
ORIENTED THIS MORNING CAUSING A DECREASE IN POPS IN THE NORTHERN
HALF OF THE MID STATE AND KEEPING LIKELY POPS SOUTH OF I-40 THIS
AFTERNOON.
PREV DISCUSSION... /ISSUED 448 AM CST WED JAN 9 2013/
DISCUSSION...
RADAR INDICATES WIDESPREAD SHOWERS ENTERING THE AREA FROM THE
SOUTHWEST THIS MORNING WITH SCATTERED SHOWERS DEVELOPING ACROSS
MOST OF MIDDLE TN. EXPECT THAT RAINFALL WILL CONTINUE THROUGHOUT
THE DAY BEING MORE WIDESPREAD IN THE SOUTHERN AND WESTERN
COUNTIES. THIS SURGE OF MOISTURE IS BEING URGED UPWARD BY A CUTOFF
LOW OVER TEXAS THAT WILL GRADUALLY MOVE NORTH INTO OKLAHOMA TODAY.
WEDNESDAY NIGHT...HEAVIEST PRECIP IS EXPECTED TO REMAIN IN THE
WESTERN HALF OF MIDDLE TN. OVERCAST SKIES WILL SETTLE IN TODAY AND
TONIGHT KEEPING LOW TEMPERATURES MILD...AROUND 50 DEGREES.
THE LOW IS EXPECTED TO REMAIN WELL TO OUR WEST...MOVING FROM
OKLAHOMA TO THE MID MISSISSIPPI VALLEY ON THURSDAY. THEREFORE, POPS WILL
REMAIN HIGH IN THE WEST ON THURSDAY WITH ONLY CHANCE POPS AROUND
THE PLATEAU. THUNDERSTORM CHANCES REMAIN HIGHEST IN THE WEST AS
WELL AND ARE INTRODUCED INTO THE FORECAST AS EARLY AS 06Z
THURSDAY. A WARM FRONT IS EXPECTED TO LIFT NORTH THROUGH THE
MID STATE SOMETIME DURING THE MORNING HOURS ON THURSDAY ENCOURAGING
MORE THUNDERSTORM DEVELOPMENT ALONG WITH HEAVY SHOWERS.
SHOWERS AND THUNDERSTORMS WILL BE LESS LIKELY EARLY FRIDAY
MORNING PRIOR TO THE MAIN MOISTURE AXIS PUSHING THROUGH. AN
ENHANCED LOW LEVEL JET AND THE PASSAGE OF ANOTHER BAND OF DEEP
MOISTURE LATER IN THE MORNING COULD INFLUENCE SOME STORMS TO
BECOME STRONG...WITH GUSTY WINDS, HEAVY DOWNPOURS, AND SMALL
HAIL. WIDESPREAD RAINFALL AMOUNTS OF 1 INCH ARE LIKELY WITH
LOCALIZED AMOUNTS AROUND 2 TO 3 INCHES POSSIBLE AT THE END OF THE
SHORT TERM.
FRIDAY AFTERNOON AND EVENING CLOUDS ARE EXPECTED TO THIN OUT, BUT
NOT DISAPPEAR AS THE LOW PRESSURE SYSTEM MOVES OFF TO THE
NORTHEAST. HIGH TEMPERATURES ON FRIDAY COULD REACH 65 DEGREES
ALONG THE PLATEAU AND NEAR 70 ELSEWHERE...VERY CLOSE TO THE DAILY
RECORD OF 72 IN NASHVILLE AND 64 IN CROSSVILLE...HOWEVER THIS IS
VERY DEPENDENT ON THE AMOUNT OF CLOUD COVER AND HOW QUICKLY IT
PARTIALLY CLEARS OUT AFTER THE BAND OF MOISTURE.
THIS WEEKEND QUICKLY BECOMES A RAINY ONE WITH THE NEXT SYSTEM
PUSHING INTO THE MID STATE SATURDAY MORNING AND LINGERING THROUGH
THE END OF THE FORECAST PERIOD. MODELS AGREE THAT A BAND OF DEEP
MOISTURE WILL SET UP ACROSS THE TENNESSEE AND OHIO VALLEYS AS A
STRONG RIDGE STAYS IN PLACE OFF THE EAST COAST. STRONG UPPER LEVEL
WINDS FROM THE SOUTHWEST WILL BRING DEEP SUBTROPICAL MOISTURE INTO
THE SOUTHEAST. PWAT VALUES STILL LOOK EXCEPTIONALLY HIGH FOR THIS
TIME OF THE YEAR..AROUND 1.5 INCHES...THROUGH AT LEAST MONDAY NIGHT.
THE DIFFERENCES IN THE BOUNDARY LOCATION WILL DETERMINE WHERE THE
HEAVIEST RAINFALL TOTALS DEVELOP AND ALSO THE TEMPERATURES IN THE
LONG TERM. COLDER AIR...NEAR SEASONAL NORMS...WILL FILE IN BEHIND
THE BOUNDARY BY MID WEEK NEXT WEEK.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHAMBURGER