Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 01/31/15
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
530 PM MST FRI JAN 30 2015
...UPDATED AVIATION DISCUSSION...
.SYNOPSIS...
AREAS OF SHOWERS WILL CONTINUE TO BE LIKELY OVER PARTS OF
SOUTH-CENTRAL ARIZONA TONIGHT...ESPECIALLY HIGHER TERRAIN...AND LESS
LIKELY OVER SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA. RAIN CHANCES
WILL CONTINUE SATURDAY BEFORE DIMINISHING SATURDAY NIGHT. SNOW
LEVELS WILL REMAIN HIGH...LOWERING TO AROUND 7000-7500 FEET BY
SATURDAY MORNING. DRY WEATHER AND A SLOW WARMING TREND BEGINS SUNDAY
AND CONTINUES THROUGH NEXT WEEK.
&&
.DISCUSSION...
REST OF TODAY THROUGH SATURDAY...
MAIN BAND OF PRECIP AS OF MID AFTERNOON HAS BEEN OVER PORTIONS OF
GILA...PINAL...AND NORTHEAST MARICOPA COUNTY WHERE A FLOOD ADVISORY
WAS IN EFFECT...INCLUDED FAR EAST PORTIONS OF THE METRO. THIS
APPEARS TO BE ASSOCIATED WITH AN AREA OF UPPER LEVEL DIVERGENCE.
LESSER SHOWERS HAVE CONTINUED OVER THE REST OF THE PHOENIX AREA WITH
LITTLE TO NO ACTIVITY OVER SOUTHWEST ARIZONA AND SOUTHEAST
CALIFORNIA. MODEL CAPE STILL LOOKS QUITE MODEST BUT HELD ON TO
SLIGHT CHANCES FOR THUNDERSTORMS FOR THE REST OF THIS AFTERNOON AND
EARLY EVENING. AS THE SYSTEM SLOWLY SHIFTS EASTWARD...SHOWERS SHOULD
START TO TREND DOWNWARD. HOWEVER...THERE IS ANOTHER VORT MAX OVER
SONORA WHICH MAY BRUSH EASTERN PORTIONS OF THE AREA AND KEEP SOME
SHOWER ACTIVITY GOING. RAP SHOWS A SEPARATE SMALLER VORT MAX MOVING
NORTHEASTWARD FROM NORTHERN BAJA INTO OUR FORECAST AREA FOR A
RESUMPTION OF LIGHT RAIN IN OUR WESTERN AREAS. THUS HELD ON TO POPS
FOR TONIGHT...LOWER NUMBERS WESTERN AREAS. OF NOTE...MOST MODELS
INDICATE THE BRUNT OF THE SONORA VORT MAX TRACKING EAST OF THE
PHOENIX AREA. YET ANOTHER VORT MAX ROUNDS THE BOTTOM OF THE UPPER
TROUGH LATE TONIGHT AND BEGINS AFFECTING SOUTHERN ARIZONA SATURDAY
MORNING. LOOKS LIKE SOUTHEAST ARIZONA WILL SEE MOST OF THE PRECIP
FROM THAT FEATURE BUT DEPICT SOME NOTABLE QPF SPREADING WELL INTO
SOUTH-CENTRAL ARIZONA. THUS WE MAY HAVE ANOTHER ROUND OF WIDESPREAD
SHOWERS BEFORE A DOWNTREND BEGINS IN THE AFTERNOON.
OVERALL...ANTICIPATE LESS DYNAMICAL LIFT TONIGHT AND SATURDAY
COMPARED TO THE PREVIOUS 24 HOURS...DUE AT LEAST IN PART TO LOSS OF
UPPER DIFFLUENCE/DIVERGENCE. ACCORDINGLY...ANTICIPATE LESS PRECIP
TONIGHT AND SATURDAY THAN WE HAD IN THE PRECEDING 24 HOURS.
ANTICIPATE NUISANCE FLOODING TO CONTINUE...MAINLY OVER HIGHER
TERRAIN AND FOOTHILL AREAS...LESS OVER VALLEY FLOORS OF THE CENTRAL
DESERTS. ONE CAVEAT IS THAT WE COULD HAVE A LITTLE BIT MORE
INSTABILITY IF CLOUDS THIN OUT ENOUGH. NAM HAS BEEN DEPICTING THIS
IDEA. THUS HELD ON TO SLIGHT CHANCE OF THUNDERSTORMS FOR SATURDAY
AFTERNOON. THE SYSTEM BEGINS EXITING SOUTHWARD SATURDAY NIGHT AS A
RIDGE BUILDS IN AND THUS POPS DIMINISH OVERNIGHT SATURDAY.
SUNDAY THROUGH FRIDAY...
SUNDAY LOOKS TO BE A DRY AND WARMER DAY. PATCHY MORNING FOG IS A
POSSIBILITY BUT THERE MAY BE ENOUGH LINGERING CLOUDS TO HINDER THE
RADIATIONAL COOLING NECESSARY. PARED BACK ON THE AREAL COVERAGE TO
REMOVE SOUTHEAST CALIFORNIA AND THE LOWER COLORADO RIVER VALLEY AS
SOME DRY ADVECTION MOVES IN THERE. THE RIDGE SLOWLY BUILDS INTO THE
WEST MONDAY THROUGH THURSDAY FOR A GRADUAL WARMING TREND...AND WE
CAN EXPECT DESERT HIGHS TO REACH BACK INTO THE LOW TO MID 70S BY
NEXT WEDNESDAY...WITH THE WARMER WESTERN DESERTS RISING TO NEAR 80
BY NEXT THURSDAY...LITTLE CHANGE FRIDAY.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA AND KSDL...
SHORT TERM: RAINFALL HAS MOVED EAST OF TERMINALS THOUGH LOWER END
MVFR CIGS ARE PERSISTING AS OF 00Z. MODERATE TO GOOD CONFIDENCE THAT
SHOWERS HAVE LARGELY ENDED FOR THE EVENING...AND CIGS WILL IMPROVE
TO UPPER MVFR OR LOWER END VFR CATEGORY IN THE 02Z-03Z TIME FRAME
(MOST LIKELY TOWARDS THE WESTERN PARTS OF THE PHOENIX METRO...AND
MAYBE MORE DELAYED TO THE EAST). VISIBILITIES WILL BE VERY
GOOD...THOUGH MOUNTAIN OBSCURATION WILL STILL BE A PROBLEM
(ESPECIALLY EAST).
TONIGHT-SAT MORNING: LOWER CONFIDENCE THAT RESIDUAL MOISTURE WILL
ALLOW MVFR BR/HZ TO FORM OVERNIGHT AND INTO SAT MORNING...AND TAF
FORECAST TIMING IS MERELY TRYING TO SET A TREND TOWARDS THIS IDEA.
SETUP FOR BR/HZ IS FAVORABLE...BUT COVERAGE MAY BE MORE SPOTTY
AND/OR ISOLATED. BETTER CONFIDENCE THAT THE NEXT ROUND OF SHOWERS
WILL IMPACT TERMINALS IN THE 12Z-18Z TIME FRAME...WITH ASSOCIATED
MVFR VSBY/CIGS LIKELY.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
SHOWERS SHOULD STAY SOUTH AND WEST OF CALIFORNIA TERMINALS THROUGH
12Z SAT...THOUGH RESIDUAL MOISTURE COULD FORM LOCAL MVFR BR/HZ
(ESPECIALLY AT THE MORE FAVORED KIPL SITE). SCT SHRA AND POTENTIALLY
BRIEF PERIODS OF MVFR CIGS/VSBY MAY BE POSSIBLE LATER SATURDAY
MORNING...THOUGH CONFIDENCE IS ONLY LOW TO MODERATE.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SUNDAY THROUGH THURSDAY...
DRIER AND SIGNIFICANTLY WARMER WEATHER IS EXPECTED...AS HIGH
PRESSURE BEGINS BUILDING BACK INTO THE REGION. HIGH TEMPERATURES IN
THE LOWER DESERTS WILL START OUT IN THE UPPER 60S ON SUNDAY AND
GRADUALLY CLIMB INTO THE UPPER 70S BY THURSDAY. WINDS ARE EXPECTED
TO BE LIGHT AND VARIABLE FOR MOST OF THE FORECAST PERIOD.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...AJ/CB
AVIATION...MO
FIRE WEATHER...MCLANE
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION...UPDATE
NWS LOS ANGELES/OXNARD CA
410 PM PST FRI JAN 30 2015
...UPDATED AVIATION DISCUSSION...
.SYNOPSIS...
LOW PRESSURE TO THE SOUTHEAST WILL BRING ISOLATED SHOWERS TO PARTS
OF THE AREA THROUGH TONIGHT. OFFSHORE FLOW WILL DEVELOP THIS
WEEKEND...RESULTING IN A CLEARING AND WARMING TREND. HIGH PRESSURE
WILL BRING ABOVE NORMAL TEMPERATURES AND FAIR SKIES NEXT WEEK. A
COLD FRONT MAY APPROACH THE CENTRAL COAST BY THE END OF NEXT WEEK.
&&
.SHORT TERM (TODAY-MON)...
SATELLITE IMAGERY SHOWS THE UPPER-LEVEL LOW CENTERED OVER SE CA THIS
AFTERNOON. RADAR SHOWING AN INCREASE IN CONVECTIVE SHOWER ACTIVITY
LIKE THE HRRR WAS SUGGESTING EARLIER...SO SLIGHT CHANCE OF SHOWERS
WILL CONTINUE THROUGH THIS AFTERNOON FOR MUCH OF LA COUNTY AND PARTS
OF VENTURA COUNTY. THE BEST CHANCE OF MEASURABLE PRECIP WILL BE IN
THE MOUNTAINS...BUT AMOUNTS SHOULD CONTINUE TO BE VERY LIGHT.
SHOWERS WILL QUICKLY COME TO AN END THIS EVENING AS THE UPPER-LOW
CONTINUES TO DRIFT SE...WITH SLIGHT CHANCES LINGERING OVER THE SAN
GABRIELS THROUGH LATE TONIGHT.
PATCHY DENSE FOG WILL BE POSSIBLE IN THE SALINAS VALLEY AGAIN
TONIGHT. SOME PATCHY LOW CLOUDS AND FOG MAY ALSO DEVELOP ON THE LA
COAST TOWARDS DAYBREAK AS A WEAK EDDY SPINS UP.
NE WINDS WILL INCREASE ACROSS THE MOUNTAINS TOMORROW MORNING AS THE
UPPER LOW CONTINUES TO DRIFT SE AND A RIDGE BUILDS INTO NORTHERN
CA...SETTING UPPER NE FLOW ALOFT. LOOKS LIKE THE NE WINDS WILL PEAK
TOMORROW AFTERNOON AND EVENING. NOT PLANNING ON PUTTING ANY WIND
ADVISORIES OUT AT THIS TIME...BUT THE EVENING SHIFT WILL HAVE TO
TAKE A CLOSER LOOK AT THE 00Z MODEL RUNS. RIGHT NOW JUST EXPECTING
SOME ISOLATED NE GUSTS TO 45 MPH IN THE LA MOUNTAINS TOMORROW
AFTERNOON AND EVENING. OFFSHORE WINDS WILL CONTINUE THROUGH SUNDAY
MORNING...BUT WILL WEAKEN AS THE UPPER-LEVEL RIDGE MOVES OVERHEAD.
SLIGHT WARMING IS EXPECTED TOMORROW WITH FEWER CLOUDS AND AN
INCREASE IN OFFSHORE FLOW...WITH FURTHER WARMING ON SUNDAY AS THE
RIDGE MOVES OVERHEAD AND WEAK OFFSHORE FLOW CONTINUES. HIGHS ON
SUNDAY WILL GENERALLY RANGE FROM THE LOW 70S TO THE UPPER 70S FOR
THE COASTAL AND VALLEY AREAS. SLIGHT COOLING POSSIBLE ON MONDAY AS
THE RIDGE WEAKENS A LITTLE...BUT OVERALL VERY LITTLE CHANGE.
.LONG TERM (TUE-FRI)...
NOT MUCH WEATHER TO TALK ABOUT IN THE LONG RANGE. VERY LITTLE CHANGE
IN TEMPERATURES EXPECTED AS A RIDGE REMAINS IN PLACE. THE RIDGE
BUILDS A BIT ON WEDNESDAY AND THURSDAY WITH A TROUGH APPROACHING
FROM THE WEST. MODELS AGREE THAT A COLD FRONT WILL TRY TO TAKE A RUN
AT THE CENTRAL COAST LATE IN THE WEEK...BEFORE A RIDGE DEVELOPS
AGAIN FOR NEXT WEEKEND. A SLIGHT CHANCE OF RAIN MAY NEED TO BE ADDED
TO THE CENTRAL COAST FOR FRIDAY IF THE LATEST ECMWF IS RIGHT. FOR
NOW KEPT CHANCES OF RAIN BELOW 20 PERCENT.
&&
.AVIATION...31/0005Z...
AT 2345Z...THERE WAS NO MARINE INVERSION PRESENT AT KLAX.
GENERALLY HI CONFIDENCE IN THE 00Z TAFS. FOR KPRB...A PERIOD OF LIFR
CIGS/VSBYS SHOULD AFFECT THE AIRFIELD ABOUT 13Z-19Z SAT. AT KLAX AND
KLGB... MVFR CIGS ARE EXPECTED LATE TONIGHT AND SAT MORNING...ALTHO
THERE IS A 30 PERCENT CHANCE OF THIS NOT OCCURRING. AT KSMX...THERE
IS A 30 PERCENT CHANCE OF MVFR CIGS AT TIMES TONIGHT. OTHERWISE...
VFR CONDITIONS ARE EXPECTED AT ALL OF THE SWRN CA AIRFIELDS THRU
SAT. IN ADDITION...GUSTY NE WINDS WILL DEVELOP AT KWJF AND KPMD SAT
AFTERNOON.
KLAX...GENERALLY HI CONFIDENCE IN THE 00Z TAF. VFR CONDITIONS ARE
EXPECTED THRU SAT EVENING...EXCEPT FOR A PERIOD OF MVFR CIGS 13Z-19Z
SAT...ALTHO THERE IS A 30 PERCENT CHANCE OF NO LOW CIGS DEVELOPING.
KBUR...GENERALLY HI CONFIDENCE IN THE 00Z TAF. VFR CONDITIONS ARE
EXPECTED THRU SAT AFTERNOON. NORTH WINDS AROUND 12 KT ARE ALSO
EXPECTED TO DEVELOP SAT AFTERNOON.
&&
.MARINE...30/200 PM...
SMALL CRAFT ADVISORY CONDITIONS FOR NORTHWEST WIND AND SEAS AROUND
10 FEET FROM PIEDRAS BLANCAS TO POINT SAL FROM 10-60 NM AND FROM THE
OUTER WATERS FROM POINT SAL TO SAN CLEMENTE ISLAND WILL LIKELY
PERSIST THROUGH SATURDAY MORNING. OTHERWISE A BROAD AREA OF LOW
PRESSURE WILL CONTINUE TO DEEPEN WHILE REMAINING NEARLY STATIONARY
OVER THE CENTRAL PACIFIC THROUGH SATURDAY EVENING AND THEN PERSIST
THROUGH SUNDAY. GALE FORCE WINDS WITHIN A FETCH AREA ORIENTED
BETWEEN 290-300 DEGREES RELATIVE TO VENTURA COUNTY IS EXPECTED TO
GENERATE SEAS AROUND 20 FEET. AND THE SWELLS FROM THE FETCH AREA ARE
EXPECTED TO ARRIVE NEXT WEEK TUESDAY AND REMAIN BELOW SCA FOR
HAZARDOUS SEAS.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
&&
$$
PUBLIC...SUKUP
AVIATION..SIRARD
MARINE...30
SYNOPSIS...SETO
WWW.WEATHER.GOV/LOSANGELES
AREA FORECAST DISCUSSION
NWS KEY WEST FL
1014 PM EST FRI JAN 30 2015
.DISCUSSION...
SKIES ARE MOSTLY CLEAR AT THIS HOUR WITH THIN CI REMAINING NORTH OF
THE KEYS. WINDS ARE OSCILLATING IN SPEED LOCALLY...BUT UPSTREAM
ACROSS THE NEARSHORE WATERS ADJACENT TO THE PENINSULA WE SEE FRESH
TO OCCASIONALLY STRONG BREEZES SLIDING SOUTHWARD. TEMPERATURES ARE
CURRENTLY IN THE MID 60S ALONG THE ISLAND CHAIN.
THE LATE EVENING LOCAL SOUNDING SHOWS THE NORTHERLY WINDS HAVE
DEEPENED THROUGH AT LEAST 10000 FEET AND ACCELERATED THROUGH MUCH OF
THAT DEPTH OVER THE PAST 12 HOURS. THE FRONT ACROSS THE PENINSULA IS
EXPECTED TO PASS THROUGH THE KEYS AND SURROUNDING WATERS LATER IN THE
OVERNIGHT PERIOD. WE ARE NOT EXPECTING MUCH...IF ANYTHING...IN THE
WAY OF PRECIPITATION AS THIS PASSES THROUGH. IN FACT...NOT A
SIGNIFICANT THERMAL MODIFICATION OF THE AIRMASS IS EXPECTED LOCALLY.
WE DO EXPECT NORTH/NORTHEAST WINDS TO ACCELERATE ALL THE WAY TO THE
SURFACE LATER IN THE OVERNIGHT PERIOD. THE AFTERNOON ZONE FORECAST
HAS THE EXPECTED CONDITIONS COVERED WELL. NO UPDATE IS PLANNED AT
THIS TIME.
&&
.MARINE...
WIND SPEEDS SHOULD DAMPEN AND AMPLIFY OVER THE NEXT COUPLE OF HOURS
AHEAD OF A DRY FRONTAL PASSAGE...EXPECTED TO OCCUR LATER IN THE
OVERNIGHT PERIOD. MAY BE ADVERTISING CONDITIONS A BIT QUICKLY AND
POSSIBLY ERRING ON THE SIDE OF CAUTION...BUT PREFERRED TO RAISE A
SMALL CRAFT ADVISORY HEADLINE FOR ALL WATERS SURROUNDING THE FLORIDA
KEYS AS WINDS ACCELERATE FROM THE NORTH/NORTHEAST LATE IN THE
OVERNIGHT PERIOD. THIS DECISION WAS HEAVILY BASED ON THE DEPICTION OF
THE HRRR SOLUTIONS OVER THE PAST FEW HOURS. AGAIN...CONDITIONS MAY BE
CLOSER TO SUNRISE...BUT THE CONFIDENCE HAS INCREASED THROUGH THE LATE
EVENING. FRESH TO OCCASIONALLY STRONG BREEZES WILL TURN MORE TO THE
EAST THROUGH THE DAY SATURDAY. SO...RECREATIONAL BOATING CONDITIONS
WILL CERTAINLY NOT BE IDEAL ON ANY OF THE WATERS SURROUNDING THE
FLORIDA KEYS AT LEAST THROUGH THE FIRST HALF OF THIS WEEKEND.
&&
.AVIATION...
...31/00Z TAF ISSUANCE...TWO SIGNIFICANT WIND CHANGES ARE EXPECTED
THROUGH EARLY SATURDAY. THE FIRST WILL BE A MODERATE INCREASE IN
NORTHEAST WINDS AROUND DAYBREAK AS A RESULT OF A DRY FRONTAL
BOUNDARY PASSING THE KEYS. THE SECOND WILL BE A RESULT OF A BUILDING
HIGH ACROSS SOUTH FLORIDA...AND WILL BRING MORE GUSTY EASTERLY WINDS
ACROSS THE ISLAND CHAIN AFTER MID MORNING AND PERSISTING THROUGH THE
REMAINDER OF THE PERIOD. OTHER THAN WIND SHIFTS...NO SIGNIFICANT
CHANGES IN FLIGHT CONDITIONS ARE EXPECTED...AS VFR SHOULD PREVAIL
THROUGH THE PERIOD.
&&
.KEY WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GM...SMALL CRAFT ADVISORY FOR GMZ031>035-042>044-052>055-072>075.
&&
$$
PUBLIC/MARINE.........04
AVIATION/NOWCASTS.....MSB
DATA COLLECTION.......VICKERY
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
410 PM CST THU JAN 29 2015
.SHORT TERM...
234 PM CST
THROUGH SATURDAY...
THE MAIN FOCUS DURING THIS PERIOD WILL BE WITH THE POTENTIAL FOR
SOME ACCUMULATING LAKE EFFECT SNOW ACROSS PORTIONS OF NORTHWESTERN
INDIANA TONIGHT INTO FRIDAY MORNING.
LOW PRESSURE NOW ACROSS THE EASTERN GREAT LAKES REGION...DROVE A
COLD FRONT ACROSS THE AREA THIS MORNING...AND HAS SINCE CONTINUED TO
PRODUCING GUSTY NORTHWEST WINDS ACROSS THE REGION THROUGH THE
AFTERNOON. WATER VAPOR IMAGERY THIS AFTERNOON INDICATES THE NEXT
SHORT WAVE DISTURBANCE NOW DIGGING SOUTHWARD OVER LAKE SUPERIOR.
THIS DISTURBANCE IS EXPECTED TO RACE SOUTHWARD ACROSS SOUTHERN LAKE
MICHIGAN THIS EVENING...AND AS IT DOES SO...IT COULD PRODUCE ENOUGH
LIFT TO SQUEEZE OUT A FEW FLURRIES...SO I HAVE ADDED THE MENTION TO
THE FORECAST THROUGH MUCH OF THE EVENING.
OTHERWISE...IT APPEARS THAT LAKE EFFECT SNOW SHOWERS WILL CONTINUE
TO DEVELOP OVER SOUTHERN LAKE MICHIGAN TONIGHT...AND AS THE BOUNDARY
LAYER FLOW OVER LAKE MICHIGAN BEGINS TO BACK NORTHERLY...IT APPEARS
THAT SOME BANDS OF LAKE EFFECT SNOW WILL BEGIN TO IMPACT PORTIONS OF
NORTHWESTERN INDIANA OVERNIGHT TONIGHT THROUGH FRIDAY MORNING. LAKE
INDUCED EQUILIBRIUM LEVELS ARE EXPECTED TO RESIDE AROUND 5,000
FEET...AND DUE TO THE COLD LOWER LEVEL ATMOSPHERE...THIS SHOULD BE
HIGH ENOUGH TO RESIDE WELL INTO THE DENDRITE GROWTH ZONE.
THEREFORE...SOME EFFICIENT SNOWFALL LOOKS TO RESULT IN SOME
ACCUMULATING POTENTIAL...ESPECIALLY ACROSS PORTIONS OF PORTER COUNTY
INDIANA IN MY AREA...WHERE SOME ISOLATED AREAS COULD GET A COUPLE
INCHES. THESE LAKE EFFECT SNOW SHOWERS WILL COME TO AN END BY EARLY
AFTERNOON AS THE FLOW BEGINS TO SHIFT WESTERLY IN RESPONSE TO A AN
AREA OF SURFACE HIGH SHIFTING SOUTHEASTWARD TOWARDS THE OHIO
VALLEY.
A BRIEF WARMING TREND LOOKS TO BE ON TAP LATE FRIDAY NIGHT AND
SATURDAY AS THIS HIGH SHIFTS OVER THE OHIO VALLEY...SETTING UP A
WEST SOUTHWESTERLY FLOW OF WARMER AIR OVER THE AREA. THIS SHOULD
ALLOW TEMPERATURES TO WARM WELL INTO THE 30S AREA-WIDE.
KJB
&&
.LONG TERM...
328 PM CST
SATURDAY NIGHT THROUGH THURSDAY...
THE MAIN FOCUS DURING THIS PERIOD WILL BE WITH THE INCREASING
POTENTIAL OF A DECENT ACCUMULATING SNOWFALL EVENT ACROSS AT LEAST
PORTIONS OF MY AREA SATURDAY EVENING THROUGH SUNDAY.
A COMPLEX WEATHER PATTERN WILL BE IN PLACE ACROSS THE CONUS DURING
THIS PERIOD. OVERALL...THE MAIN DISTURBANCE OF INTEREST IS NOW
EJECTING EAST-NORTHEASTWARD ACROSS THE NORTHEASTERN PACIFIC ALONG
THE EASTERN PERIPHERY OF AN UPPER LOW SOUTH OF THE ALEUTIANS. THIS
FEATURE WILL MOVING ONSHORE ACROSS THE BRITISH COLUMBIA COAST BY
FRIDAY MORNING...THEN IS EXPECTED TO DIG SOUTHEASTWARD ALONG THE
NORTHEASTERN PERIPHERY OF AN UPPER LEVEL RIDGE IN PLACE ACROSS THE
WESTERN CONUS. THE MAIN COMPLEXITIES WITH THIS SYSTEM...IS IF AND
HOW MUCH OF THE SOUTHERN STREAM ENERGY...EMANATING FROM THE
SOUTHWESTERN CONUS TROUGH...GETS TAPPED INTO BY THIS DIGGING SYSTEM.
MODEL GUIDANCE HAS FLIPPED FLOPPED A BIT OVER THE PAST COUPLE OF
RUNS ON HOW FAR NORTH THE ACCOMPANYING PRECIPITATION SHIELD WILL GET
SATURDAY NIGHT INTO SUNDAY. IT APPEARS ONE OF THE MAIN KEYS THAT
WILL PLAY A ROLE IN HOW FAR NORTH THE SNOWFALL ENDS UP GETTING
ACROSS ILLINOIS WILL BE THE TIMING OF COLDER AIRMASS/COLD FRONTAL
PASSAGE EXPECTED ON SATURDAY NIGHT. A MUCH COLDER AIRMASS IS
EXPECTED TO SPILL IN ACROSS THE NORTHERN CONUS AHEAD OF A STOUT 1044
MB HIGH BUILDING SOUTHWARD OUT OF SOUTHERN MANITOBA SATURDAY
NIGHT...AND THIS SHOULD SET UP A GOOD BAROCLINIC ZONE POTENTIALLY
RIGHT ACROSS THE HEART OF MY CWA SATURDAY NIGHT INTO SUNDAY. AT THE
SAME TIME...ISENTROPIC ASCENT AND MOISTURE TRANSPORT WILL RAMP UP TO
OUR SOUTHWEST IN ADVANCE OF THE APPROACHING DISTURBANCE. THIS SHOULD
RESULT IN A LARGE AREA OF SNOWFALL DEVELOPMENT IN THE COLD AIR ACROSS
MISSOURI AND WEST CENTRAL ILLINOIS BY SATURDAY AFTERNOON. IT APPEARS
THIS SNOWFALL WILL GRADUALLY DEVELOP NORTHWARD ACROSS ILLINOIS BY
SATURDAY EVENING...AND MAY END UP IMPACTING MOST OF MY AREA TO SOME
DEGREE OVERNIGHT SATURDAY AND INTO SUNDAY. IT APPEARS THAT A DECENT
BAND OF FRONTOGENESIS COULD SET UP SOMEWHERE NEAR THE I-80 CORRIDOR
INTO SUNDAY MORNING AS A DEFORMATION AXIS TRIES TO DEVELOP WITH THE
925-850 MB LAYER AHEAD OF THE APPROACHING COLD AIRMASS. THIS COULD
RESULT IN SOME AREAS OF HEAVIER SNOW. HOWEVER...CONFIDENCE ON WHERE
EXACTLY THIS ENHANCED MESOSCALE FORCING SETS UP IS LOW AT THIS
TIME...GIVEN THIS SYSTEM IS 60+ HOURS AWAY. IT DOES APPEAR THAT MOST
AREAS MAY SEE AT LEAST SOME LIGHT SNOW ACCUMULATIONS...BUT THE
POTENTIAL OF A FEW TO SEVERAL INCHES OF SNOW ACCUMULATION IS
CERTAINLY A POSSIBILITY.
THE OTHER FACTOR TO CONSIDER WITH THIS EVENT IS THE POTENTIAL FOR
LAKE ENHANCED SNOW SHOWERS LATER SUNDAY AND INTO SUNDAY NIGHT ACROSS
NORTHEASTERN ILLINOIS. AS THE COLDER AIRMASS BEGINS TO SPILL
SOUTHWARD OVER THE AREA ON SUNDAY...WINDS WILL BECOME NORTHEASTERLY
OFF OF LAKE MICHIGAN. THE COLDER AIRMASS...FEATURING 850 MB
TEMPERATURES IN THE TEENS BELOW ZERO CELSIUS...SHOULD ALSO PRODUCE
FAVORABLE THERMODYNAMICS IN THE LOWEST LEVELS OF THE ATMOSPHERE FOR
ENHANCED SNOW SHOWERS LATER SUNDAY AND SUNDAY NIGHT. MODEL SOUNDINGS
INDICATE INVERSION HEIGHTS REACHING UP AROUND 5-6,000 FEET...WHICH
SHOULD EXTEND WELL INTO THE DENDRITIC GROWTH ZONE. THEREFORE...WE CANT
RULE OUT THE POTENTIAL FOR SOME HEAVIER SNOW TOTALS ACROSS PORTIONS
OF NORTHEASTERN ILLINOIS. AT THIS TIME...I HAVE REMAINED A BIT
CONSERVATIVE ON SNOW AMOUNTS ACROSS NORTHERN ILLINOIS...MAINLY DUE
TO THE HIGH UNCERTAINTIES WITH THIS EVOLVING SYSTEM.
FOLLOWING THIS SYSTEM...IT APPEARS THE REGION WILL REMAIN IN AND
ACTIVE WEST/NORTHWESTERLY FLOW PATTERN. THIS COULD SUPPORT A FEW
ADDITIONAL CLIPPER TYPE SYSTEMS WITH SNOW CHANCES AND REINFORCING
SHOTS OF COLD AIR THROUGH THE EXTENDED PERIOD. OVERALL...IT APPEARS
THAT WE WILL REMAIN BELOW TO WELL BELOW AVERAGE FOR TEMPERATURES
NEXT WEEK. A PERIOD OF VERY COLD CONDITIONS COULD ALSO BE IN THE
WORKS FOR THE LATTER PART OF NEXT WEEK...WITH THE POSSIBILITIES OF A
SYSTEM DIGGING SOUTHWARD OVER THE AREA FROM THE HIGH LATITUDES OF
CANADA.
KJB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* NORTHWEST WINDS WITH ERRATIC SPEEDS BETWEEN 12 AND 17 KT GUSTING
TO AROUND 25 KT OR SO THROUGH AT LEAST MIDNIGHT...TAPERING SOME
OVERNIGHT.
* MVFR CIGS LIFTING TO VFR LATE EVENING OR EARLY TONIGHT.
* FLURRIES THIS EVENING POSSIBLY REDUCING VSBY TO MVFR.
MDB
//DISCUSSION...UPDATED 22Z...
NORTHWEST WINDS CONTINUE TO BE QUITE VARIABLE IN SPEED. ONE UPPER
WAVE IS CROSSING THE AREA AND AM THINKING THAT WINDS WILL PICK UP
A BIT CLOSER TO 00Z BEHIND THIS WAVE. ANOTHER WAVE WILL THEN CROSS
MID EVENING AND MAY RESULT IN ANOTHER BRIEF DECREASE IN SPEEDS
BEFORE INCREASING AGAIN LATE THIS EVENING. CIGS HAVE IMPROVED
UPSTREAM TO THE NORTH SO HAVE GONE WITH SLIGHTLY HIGHER CIGS IN
THE LATEST TAF BUT MAY NEED TO SPEED THE IMPROVEMENT TO VFR BY A
FEW HOURS.
MDB
FROM 18Z...
MAIN AVIATION CONCERN IS WITH GUSTY NW WINDS THIS AFTERNOON AND
TONIGHT. WE HAVE HAD A HARD TIME REALIZING DEEPER MIXING WITH THE
SOLID MVFR CLOUD DECK IN PLACE. WE HAVE SEEN OCCASIONAL 30 KT
GUSTS ON 1-MINUTE ASOS OBSERVATIONS...BUT IN GENERAL SUSTAINED
WINDS HAVE BEEN IN THE MID TO UPPER TEENS WITH GUSTS INTO THE MID
20S. EXPECT THESE WINDS TO REMAIN IN PLACE THIS AFTERNOON AND
EVENING AS A SECOND WAVE OF COLD AIR ADVECTION ENSUES TONIGHT.
NEXT CONCERN IS AROUND MVFR CIGS AND POSSIBLE FLURRIES TONIGHT.
CIGS SHOULD GENERALLY REMAIN ABOVE 1500 FT WITH THE GUSTY WINDS
AND MIXED VERY LOW LEVELS. A WEAKER TROUGH AXIS WILL MOVE THROUGH
THE TERMINALS THIS AFTERNOON...FOLLOWED BY A SHARPER VORT MAX THIS
EVENING. UPSTREAM OBSERVATIONS IN NORTHERN MINNESOTA AHEAD OF THIS
WAVE HAVE BEEN REPORTING SOME FLURRIES AND POSSIBLY EVEN SOME
FREEZING DRIZZLE. AS THIS WAVE MOVES THROUGH THIS EVENING...LOWER
LEVEL TEMPERATURES COOL TO THAT POINT TO SUPPORT SOME FLURRIES
AND POSSIBLE VISIBILITY REDUCTION IF THIS ACTIVITY. CONFIDENCE ON
THIS IS LOW ON SPECIFICALLY IMPACTING ANY PARTICULAR TERMINAL...SO
IT HAS NOT BEEN MENTIONED IN THE TAFS AT THE MOMENT. BUT
CONFIDENCE IS PRETTY HIGH THAT THE MVFR CIGS LINGER THROUGH MUCH
OF THE NIGHT. HIGH PRESSURE BUILDS IN TOMORROW WHICH RESULTS IN
LIGHTER WINDS AND LIKELY SOME SCATTERING OUT OF THE LOW CLOUD
DECK...BUT CONFIDENCE TIMING THE SCATTERING IS NOT VERY HIGH.
KMD
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* HIGH IN SUSTAINED SPEEDS BEING ERRATIC AND MEDIUM-HIGH IN GUST
SPEEDS.
* MEDIUM CONFIDENCE IN TIMING OF IMPROVEMENT TO VFR CIGS AND TIME
OF SCATTERING. MAY NEED TO SPEED UP IMPROVEMENT TO VFR.
* LOW ON FLURRIES AND ANY ASSOCIATED VSBY REDUCTION THIS EVENING.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...VFR. SOUTHWEST WINDS.
SATURDAY...CHANCE OF SNOW AND IFR DURING THE NIGHT. WEST WINDS.
SUNDAY...CHANCE OF SNOW AND IFR. AT LEAST MVFR CIGS LIKELY.
NORTHEAST WINDS.
MONDAY NIGHT-WEDNESDAY...CHANCES OF MAINLY LIGHT SNOW. WEST WINDS.
MTF
&&
.MARINE...
153 PM CST
ACTIVE PATTERN LOOKS TO PERSIST THROUGH THE WEEKEND WITH MUCH
COLDER AIR ARRIVING EARLY NEXT WEEK. WITH THE SLOW AND STEADY
DEPARTURE OF TWO LOW PRESSURES OVER THE WESTERN GREAT LAKES THIS
MORNING...THE TWO LOWS ARE NOW CONSOLIDATING OVER NORTHEAST LAKE
HURON. ALONG THE BACK EDGE OF THESE LOW PRESSURES...THE PRESSURE
GRADIENT HAS TIGHTEN AND WAS PRODUCING GALE FORCE WINDS TO 35 KT
FROM THE NORTHWEST. MOST OF THE AFTERNOON WINDS HAVE BEEN HELD TO
AROUND LOW END GALES OR JUST UNDER GALE FORCE...HOWEVER AS THE
AFTERNOON PROGRESSED MIXING HAS BEEN ABLE TO BRING TO THE SURFACE
MUCH STRONGER WINDS. AS A RESULT WILL MAINTAIN THE CURRENT GALE
WARNING THROUGH THIS EVENING. WITH THE STRONGEST GRADIENT OVER THE
NORTHERN HALF OF THE LAKE...PRODUCING GALES TO 40KT AT TIMES...THIS WILL
LIKELY PRODUCE HEAVY FREEZING SPRAY. FURTHER SOUTH THE GALES WILL
LIKELY REMAIN AROUND 35KT AND THE FREEZING SPRAY SHOULD ONLY BE
ALONG THE MODERATE LEVEL AND NOT REQUIRE A HEADLINE.
WAVES WILL CONTINUE TO BUILD EARLY THIS EVENING...WITH THE HIGHEST
WAVES BETWEEN 12-15 FT TONIGHT. HIGH PRESSURE THEN QUICKLY ARRIVES
AND BRINGS LIGHTER WINDS TO THE LAKE BY MIDDAY FRIDAY. THEN HIGH
PRESSURE QUICKLY SLIDES EAST/SOUTHEAST...WITH WINDS TURNING
SOUTHERLY AHEAD OF YET ANOTHER LOW PRESSURE SYSTEM OVER THE
WEEKEND. A FRONTAL BOUNDARY WILL SLIDE SOUTH FROM CANADA
SATURDAY...AND COULD DEVELOP A TIGHT GRADIENT OVER THE LAKE FOR A
PERIOD SATURDAY NIGHT INTO SUNDAY. AT THIS TIME IT LOOKS LIKE
NORTH/NORTHEAST WINDS WILL TOP OUT AROUND 30KT...BUT COULD SEE A
FEW GALE FORCE GUSTS FOR A FEW HOURS EARLY SUNDAY. THEN HIGH
PRESSURE PUSHES OVER THE WESTERN GREAT LAKES SUNDAY NIGHT INTO
MONDAY. UNFORTUNATELY ANOTHER ACTIVE PATTERN LOOKS FAVORABLE FOR
EARLY NEXT WEEK.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...HEAVY FREEZING SPRAY WARNING...LMZ261-LMZ362-LMZ364-LMZ366-
LMZ563-LMZ565-LMZ567-LMZ868 UNTIL 3 AM FRIDAY.
GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-LMZ742-
LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-
LMZ874-LMZ876-LMZ878 UNTIL 3 AM FRIDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
330 PM CST Thu Jan 29 2015
.SHORT TERM...(Tonight)
ISSUED AT 329 PM CST THU JAN 29 2015
Forecast challenge for tonight will be whether or not any partial
clearing will occur and the affect on low temperatures. The latest
satellite loop early this afternoon indicated an area of partly
cloudy skies in central/southern MN into central IA behind a
departing shortwave trough. This area was starting to fill in with a
few more clouds, though, the past hour. The latest guidance from the
RAP, HRRR and NAM all indicate that moisture in the lowest 100 mb
should stay high enough overnight for low clouds to persist until
Friday morning. Breaks in the clouds may occur at times late this
evening, but they shouldn`t low enough to impact low temperatures.
As a result will go with lows in the 20-25 range across all of
central and southeast IL.
Patches of drizzle/flurries may linger in parts of central Illinois
early this evening. However, this will have very small areal
coverage and will have little or no impact, so will not include in
the forecast for tonight.
As the low pressure center moves through the eastern Great Lakes
late this evening, the pressure gradient should loosen up, resulting
in gradually diminishing winds in central Illinois early tonight,
and in eastern Illinois by daybreak.
&&
.LONG TERM...(Friday through Thursday)
ISSUED AT 329 PM CST THU JAN 29 2015
Models have come into better agreement with the main focus for this
forecast, this weekend winter weather system. The GFS and ECMWF both
look very similar with location of the heaviest snowfall Sat night
through Sun. Only differences in the those two models is the timing
and track of the low press area as it moves northeast across the
southern Miss valley. Precip will begin to spread into the western
parts of the CWA Sat afternoon, but temps will be warm enough for
most of the pcpn to be either rain, or a mix of rain or snow. No
accumulations are expected during the afternoon due to the warm
temps. The major part of the snow will arrive late Sat night, after
midnight, through some light accumulations are possible Sat evening.
After midnight, the snow is expected to become moderate with rates
approaching 1/2 inch per hour. The snow will be during the
overrunning period of the system as it begins to lift out of the
southern plains. With the upper level part of the system being just
an open trough/wave, a heavy deformation area of snow will likely
not setup on the back side of the low pressure area. However, snow
will continue Sun afternoon through Sun evening, with accumulations
being on the lighter side. Preliminary indications are that snowfall
totals from Sat evening through Sun night will be in the 4.5 to 6
inch range. There is still some uncertainty with these amounts as
the models are just now coming into agreement and some shift south
or north with the track is still possible. Given the longer duration
of the snowfall, it does not meet criteria for a watch at this time,
so no headlines will be issued. A later forecast shift may decide to
issue one if any changes occur with the model forecasts.
Beyond this system this weekend, conditions will be relatively dry,
except for Tue night when another chance of snow is possible from a
system coming down from the northwest. Once this system pushes
through, temps will drop and become well below normal for Wed
through Thur.
&&
.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
ISSUED AT 1206 PM CST THU JAN 29 2015
The main aviation concerns will be with MVFR ceilings and the
strong northwest wind gusts across central and eastern Illinois.
The latest satellite loop and surface observations indicated a
large area of MVFR ceilings across all of Illinois and much of
Iowa. The main question is the advancement of an area of partial
clearing from southern MN and central IA, and when the MVFR
ceilings will dissipate. The vast majority of short range models
indicate that a shortwave trough axis will swing through central
and eastern IL late this evening. However, most of these same
models including the NAM, RAP and HRRR indicate that there will be
plenty of low level moisture trapped below a stout inversion. This
would keep at least broken MVFR ceilings in the area through the
night and into much of Friday morning. Will follow this line of
thinking as it can be very difficult to erode low level clouds
this time of year.
The tight pressure gradient will keep northwest winds gusting
around 25-30 knots through the afternoon into early evening at
most TAF sites - particularly in east central Illinois. The
lessening impact of the surface low moving through the eastern
Great Lakes will result in diminishing wind in central IL late
this evening, and in eastern Illinois before daybreak.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Miller
LONG TERM...Auten
AVIATION...Miller
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
153 PM CST THU JAN 29 2015
.SHORT TERM...
358 AM CST
TODAY THROUGH FRIDAY NIGHT...
THE MAIN FORECAST CONCERNS THIS MORNING INVOLVE THE AREA OF LOW
PRESSURE CURRENTLY OVER WEST CENTRAL ILLINOIS...AND INCLUDE PRECIP
TIMING/TYPE...TEMPERATURE TRENDS...GUSTY WINDS...AND EVENTUALLY THE
POTENTIAL FOR SOME LAKE EFFECT SNOW SHOWERS OVER NORTHWEST INDIANA
TONIGHT INTO FRIDAY.
THE SURFACE LOW CENTER WAS JUST SOUTHWEST OF LASALLE/PERU ILLINOIS
AT 3 AM CST...WITH THE ASSOCIATED CYCLONIC WIND CIRCULATION PULLING
RELATIVELY MILD AIR NORTH ACROSS THE EASTERN 2/3 OF THE CWA.
CHALLENGING HOURLY TEMPERATURE FORECAST...AS READINGS MAY REACH 40
DEGREES IN THE SOUTHEAST EARLY THIS MORNING BEFORE THE LOW PASSES
AND SHIFTS WINDS TO THE NORTHWEST AND PULLS IN COLDER AIR. WITH THE
EXCEPTION OF A BAND OF RAIN SHOWERS LATE LAST EVENING...LITTLE
PRECIPITATION HAS BEEN OCCURRING WITH THIS SYSTEM EXCEPT NORTH/EAST
OF THE FORECAST AREA OVERNIGHT. REGIONAL RADAR MOSAIC HAS BEEN
DEPICTING PERSISTENT LIGHT RETURNS BEHIND THE LOW/COLD FRONT HOWEVER
WHERE SOME OCCASIONAL DRIZZLE OR "UNKNOWN" PRECIP HAS BEEN REPORTED.
HIGH-RES GUIDANCE TRENDS CONTINUE TO INDICATE SOME VERY LIGHT
PRECIPITATION IS POSSIBLE ACROSS THE AREA THIS MORNING...WITH
FORECAST SOUNDINGS INDICATING MAINLY DRIZZLE WITH SATURATION MAINLY
IN LOW LEVELS AS COLDER AIR MOVES IN...THOUGH A BRIEF PERIOD OF
MID-LEVEL MOISTURE WITH RAGGED DEFORMATION AREA ALONG WEST/NORTHWEST
SIDE OF THE LOW COULD BRIEFLY INTRODUCE ICE INTO LOW LEVELS IN A
SEEDER-FEEDER SITUATION WHICH COULD RESULT IN A MIX OF DRIZZLE/LIGHT
RAIN AND LIGHT SNOW THIS MORNING...THOUGH NOT EXPECTING ANY REAL
MEASURABLE PRECIPITATION OR SNOW WITH THIS. STRONG DRYING ABOVE THE
BOUNDARY LAYER FROM THE NORTHWEST BY MIDDAY SHOULD ALLOW ANY LIGHT
PRECIP TO END FROM WEST TO EAST THROUGH THE LATE MORNING AND MIDDAY
HOURS.
WINDY CONDITIONS WILL DEVELOP DURING THE MORNING AS COLD ADVECTION
STEEPENS OUR LOW LEVEL LAPSE RATES IN THE TIGHT PRESSURE GRADIENT
WEST OF THE LOW. FORECAST SOUNDINGS INDICATE GUSTS AROUND 35 MPH
WILL BE POSSIBLE FROM MID-MORNING THROUGH THE AFTERNOON BEFORE WINDS
GRADUALLY DIMINISH TONIGHT. A QUICK NOTE OF TEMPERATURES WEST OF THE
LOW THIS MORNING INDICATES READINGS DO NOT DROP OFF TOO DRAMATICALLY
AND WILL LIKELY SEE STEADY TEMPS FOR THE MOST PART UNTIL LATE TODAY.
(EXCEPT IN THE SOUTHEAST WHERE TEMPS APPROACH 40 THIS MORNING...WILL
LIKELY SETTLE BACK TO THE MID 30S THERE).
AS FOR LAKE EFFECT TONIGHT...LOW LEVEL WINDS FROM THE
NORTH-NORTHWEST (AROUND 340 DEG) SUPPORT AN INITIAL CONVERGENCE ZONE
ALONG THE SOUTHWEST MICHIGAN SHORE THIS AFTERNOON AND EARLY THIS
EVENING...THOUGH OUR LOCALLY RUN ARW MODEL DOES VEER WINDS LATER
TONIGHT AND BRINGS CONVERGENT BAND INTO PORTER COUNTY LATE TONIGHT
INTO EARLY FRIDAY. LARGER SCALE FLOW BACKS MORE WESTERLY FRIDAY
AFTERNOON WHICH SHOULD PUSH ANY LINGERING SNOW SHOWERS BACK EAST OF
PORTER COUNTY BY MID/LATE FRIDAY AFTERNOON. THERMODYNAMICS ARE NOT
SPECTACULAR...THOUGH VARIOUS MODEL FORECAST SOUNDINGS DEVELOP
LAKE-850 HPA DELTA-T AROUND 17C EARLY FRIDAY WITH INVERSION HEIGHTS
5000-6000 FT BEFORE CONDITIONS GRADUALLY WANE LATER FRIDAY MORNING.
DEPENDING UPON HOW LONG THE BAND BACKS UP INTO PORTER/EASTERN LAKE
COUNTIES WILL MODULATE THE SNOWFALL ACCUMULATION POTENTIAL...THOUGH
A FEW INCHES ARE CERTAINLY POSSIBLE IF THE BAND DOES HANG UP THERE
FOR A WHILE LATE TONIGHT/EARLY FRIDAY...BEFORE EXPANSIVE SURFACE
HIGH BUILDS ACROSS THE AREA THROUGH FRIDAY NIGHT.
RATZER
&&
.LONG TERM...
358 AM CST
SATURDAY THROUGH WEDNESDAY...
THE MAIN CONCERN IN THE EXTENDED PERIOD CONTINUES TO BE THE
POTENTIAL FOR SOME ACCUMULATING SNOW OVER THE WEEKEND...ESPECIALLY
ACROSS THE SOUTHERN PART OF THE CWA LATE SATURDAY NIGHT AND SUNDAY.
GLOBAL RUNS CONTINUE TO SHOW AGREEMENT IN FIRST SAGGING A COLD FRONT
SOUTH ACROSS THE AREA SATURDAY...THEN WITH THE AMPLIFICATION OF AN
UPPER TROUGH OVER THE REGION WITH SUBSEQUENT SURFACE LOW DEVELOPMENT
OVER THE LOWER MISSISSIPPI VALLEY. WHILE THE TRACK OF THE SURFACE
LOW HAS TRENDED SOUTH OVER THE PAST FEW RUNS (NOW FROM THE LOWER
MISS VALLEY TO THE MID-ATLANTIC OR CAROLINA COAST BY MONDAY
MORNING)...NORTHERN PERIPHERY OF DEFORMATION BAND SNOW ACROSS
CENTRAL ILLINOIS/INDIANA WOULD STILL AFFECT SOUTHERN COUNTIES OF THE
LOT CWA AT THIS POINT. IN ADDITION...INCREASING NORTH-NORTHEAST
WINDS NORTH OF THE LOW TRACK COMBINED WITH ARCTIC AIR INTRUSION
BEHIND SATURDAY COLD FRONT COULD VERY WELL LEAD TO LAKE
EFFECT/ENHANCED SNOW SHOWERS INTO THE CHICAGO METRO AREA. SO...
WHILE MANY DETAILS REMAIN TO BE WORKED OUT HAVE MAINTAINED DECENT
CHANCE POPS FOR MEASURABLE SNOW ACROSS THE FORECAST AREA FOR THE
WEEKEND. STILL LOOKS COLD BEYOND THE WEEKEND INTO NEXT WEEK WITH
DEEP TROUGH ACROSS THE EAST...THOUGH PATTERN CONTINUES TO BE
PROGRESSIVE IN LONGER RANGE GUIDANCE SOLUTIONS WHICH KEEPS IT FROM
STICKING AROUND TOO LONG.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* NORTHWEST WINDS GUSTING TO AROUND 25 KT OR SO THROUGH AT LEAST
MIDNIGHT...TAPERING SOME OVERNIGHT.
* MVFR CIGS PERSISTING INTO THE EVENING...LIFTING TO VFR EITHER
OVERNIGHT OR INTO FRIDAY MORNING.
* FLURRIES THIS EVENING REDUCING VSBY TO MVFR.
KMD
//DISCUSSION...UPDATED 18Z...
MAIN AVIATION CONCERN IS WITH GUSTY NW WINDS THIS AFTERNOON AND
TONIGHT. WE HAVE HAD A HARD TIME REALIZING DEEPER MIXING WITH THE
SOLID MVFR CLOUD DECK IN PLACE. WE HAVE SEEN OCCASIONAL 30 KT
GUSTS ON 1-MINUTE ASOS OBSERVATIONS...BUT IN GENERAL SUSTAINED
WINDS HAVE BEEN IN THE MID TO UPPER TEENS WITH GUSTS INTO THE MID
20S. EXPECT THESE WINDS TO REMAIN IN PLACE THIS AFTERNOON AND
EVENING AS A SECOND WAVE OF COLD AIR ADVECTION ENSUES TONIGHT.
NEXT CONCERN IS AROUND MVFR CIGS AND POSSIBLE FLURRIES TONIGHT.
CIGS SHOULD GENERALLY REMAIN ABOVE 1500 FT WITH THE GUSTY WINDS
AND MIXED VERY LOW LEVELS. A WEAKER TROUGH AXIS WILL MOVE THROUGH
THE TERMINALS THIS AFTERNOON...FOLLOWED BY A SHARPER VORT MAX THIS
EVENING. UPSTREAM OBSEVATIONS IN NORTHERN MINNESOTA AHEAD OF THIS
WAVE HAVE BEEN REPORTING SOME FLURRIES AND POSSIBLY EVEN SOME
FREEZING DRIZZLE. AS THIS WAVE MOVES THROUGH THIS EVENING...LOWER
LEVEL TEMPERATURES COOL TO THAT POINT TO SUPPORT SOME FLURRIES
AND POSSIBLE VISIBILITY REDUCTION IF THIS ACTIVITY. CONFIDENCE ON
THIS IS LOW ON SPECIFICALLY IMPACTING ANY PARTICULAR TERMINAL...SO
IT HAS NOT BEEN MENTIONED IN THE TAFS AT THE MOMENT. BUT
CONFIDENCE IS PRETTY HIGH THAT THE MVFR CIGS LINGER THROUGH MUCH
OF THE NIGHT. HIGH PRESSURE BUILDS IN TOMORROW WHICH RESULTS IN
LIGHTER WINDS AND LIKELY SOME SCATTERING OUT OF THE LOW CLOUD
DECK...BUT CONFIDENCE TIMING THE SCATTERING IS NOT VERY HIGH.
KMD
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH IN WINDS...MEDIUM ON GUSTS.
* HIGH IN MVFR CIGS ABOVE 1800 FT THROUGH AT LEAST MIDNIGHT. LOW-
MEDIUM ON SPECIFIC SCATTERING TIME...WHICH WOULD COULD BE
BETWEEN 6Z AND 9Z BUT MOST LIKELY BE SOME TIME AFTER 12Z.
* LOW ON FLURRIES AND ANY ASSOCIATED VSBY REDUCTION THIS EVENING.
KMD
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...VFR. SOUTHWEST WINDS.
SATURDAY...CHANCE OF SNOW AND IFR DURING THE NIGHT. WEST WINDS.
SUNDAY...CHANCE OF SNOW AND IFR. AT LEAST MVFR CIGS LIKELY.
NORTHEAST WINDS.
MONDAY NIGHT-WEDNESDAY...CHANCES OF MAINLY LIGHT SNOW. WEST WINDS.
MTF
&&
.MARINE...
205 AM CST
A PROGRESSIVE ACTIVE PATTERN WILL CONTINUE ACROSS THE GREAT LAKES
REGION INTO THE BEGINNING OF FEBRUARY. MOVING EASTWARD EARLY THIS
MORNING IS AN ELONGATED TROUGH WITH TWO LOW PRESSURE CENTERS
COMPOSING IT...ONE PASSING JUST SOUTH OF LAKE MICHIGAN AND ANOTHER
OVER EASTERN LAKE SUPERIOR. TOGETHER THESE WILL CONSOLIDATE LATER
TODAY AND DRIVE MORE FOCUSED AND STRENGTHENING COLD ADVECTION
OVER LAKE MICHIGAN. THIS WITHIN THE STRONG AND ADVECTING PRESSURE
GRADIENT WILL SUPPORT NORTHWEST TO NORTH GALES...EVEN 45 KT GUST
POTENTIAL ACROSS PARTS OF THE NORTH. THE ILLINOIS AND ESPECIALLY
THE INDIANA NEAR SHORES SHOULD AT LEAST EXPERIENCE PERIODIC GALE
GUSTS INTO THIS EVENING. COLDER TEMPERATURES WILL BE WORKING
SOUTHWARD ACROSS THE LAKE LATER TODAY AND TONIGHT. SUPPORT FOR
HEAVY FREEZING SPRAY REMAINS OVER MAINLY THE NORTH AND CONTINUE
THE WARNING THERE. WAVES ARE LIKELY TO BUILD TO 12-15 FT TONIGHT
AT DOWNSTREAM FETCH LOCATIONS ON THE EASTERN HALF OF THE LAKE.
WINDS WILL GRADUALLY DIMINISH OVERNIGHT INTO FRIDAY MORNING AND
MORE QUICKLY AFTERWARD AS HIGH PRESSURE MOVES OVER THE LAKE.
BEYOND...THERE LOOKS LIKE OPPORTUNITIES FOR AT LEAST 30 KT WINDS
NEXT WEEK. ONE OF THESE IS BEHIND A COLD FRONT SATURDAY AFTERNOON
AND MORE SO SATURDAY NIGHT. MORE 30 KT WIND POTENTIAL WOULD COME
POSSIBLY TUESDAY AS RETURN SOUTHWEST FLOW SPREADS BACK OVER THE
LAKE.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-LMZ742-
LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-
LMZ874-LMZ876-LMZ878 UNTIL 3 AM FRIDAY.
HEAVY FREEZING SPRAY WARNING...LMZ261-LMZ362-LMZ364-LMZ366-
LMZ563-LMZ565-LMZ567-LMZ868 UNTIL 3 AM FRIDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1207 PM CST Thu Jan 29 2015
.UPDATE...
ISSUED AT 1054 AM CST THU JAN 29 2015
Only minor updates were made to the forecast for this afternoon in
central and southeast Illinois. The latest satellite loop shows
plenty of cloud cover upstream, so cloudy conditions will prevail
until at least tonight. There is a weak shortwave embedded in the
northwest flow across southeast Iowa. This should bring a period
of drizzle to west central Illinois early this afternoon, so
included that in the forecast west of I-55.
A steep pressure gradient will keep windy conditions in place this
afternoon, especially in central and eastern IL. Increased the
gusts slightly in a few places, otherwise the current forecast has
a good handle on the gusty northwest winds.
The cloud cover and weak low level cold advection will keep
temperatures fairly steady through the afternoon in the 35-40
range across the entire area.
&&
.SHORT TERM...(Today)
ISSUED AT 447 AM CST THU JAN 29 2015
Low pressure centered just north of Moline at 08z/2am will continue
to push east and drag a cold front through our area this morning.
Warmest temperatures will be just ahead of the cold front early this
morning, and then we expect temperatures to fall off quickly just
behind the cold front during the remainder of the morning, and then
hold fairly steady this afternoon. Winds will be gusty again today
but this time out of the northwest with a few gusts of 35 to 40 mph
at times about an hour or two after frontal passage right along the
stronger surface pressure rises. Look for gusts in the 30 to 35 mph
range this afternoon.
Not seeing a lot of precip, other than some occasional very light
rain/drizzle out in Iowa so will continue with just a slight chance
of light rain/snow this morning with POPs decreasing from west to
east this afternoon, and that would be mainly across the north half
of the forecast area. Latest satellite data and upstream surface
observations not showing much hope for any clearing across our area
in the near term. Forecast soundings off the NAM-WRF showing a
fairly strong subsidence inversion setting up again in the wake of
this system resulting in quite a bit of low level moisture trapped
beneath the inversion at around 2500-3000 feet. As a result, we have
backed off with any decrease in cloud cover until later this evening
and that may be optimistic based on the latest (06z) forecast
soundings off the NAM.
&&
.LONG TERM...(Tonight through Wednesday)
ISSUED AT 447 AM CST THU JAN 29 2015
Short wave trof to exit east and se of IL early this evening as
Canadian high pressure over the Canadian Rockies settles into the
upper Midwest tonight. However an inversion will likely trap low
level clouds longer tonight and have trended the forecast slower
with decreasing low clouds from the west. Low clouds could linger
over ne counties into Friday morning especially near IN border.
Cooler lows tonight in upper teens to near 20F northern areas to mid
20s in southeast IL. Brisk nw winds 15-25 mph this evening to slowly
diminish during overnight into Friday morning as high pressure
settles into IL on Friday. Highs Friday 29-35F with coolest readings
from I-74 ne with partly to mostly sunny skies.
High pressure settles into the Ohio river valley Friday evening and
into central Appalachians by dawn Sat and continue fair/dry weather
through at least Saturday morning. Lows Friday night in upper teens
and lower 20s again. Milder highs Sat in upper 30s and lower 40s
with mildest readings sw areas with ssw breezes. Clouds to increase
later Friday night into Sat ahead of next storm system with slight
chance of light rain/snow later Saturday afternoon west of I-55. Most
over central and especially eastern IL should still be dry through the
daytime hours on Saturday.
12Z Jan 28 forecast models trended further south with low pressure
system Sat night and Sunday, while 00Z Jan 29 forecast models have
trended back north with more phasing of southern and northern stream
upper level systems, along with higher snowfall amounts over central
and southeast IL. 00Z models have also trended colder with even
southeast IL looking like all snow with this eveng and mixed
precipitation south of I-64 toward the ohio river. Confidence is not
too high yet with this potentially high impact winter weather event
with extended period of overrunning snow developing Saturday night
and continue through Sunday before diminishing Sunday night. Several
inches of snow still appears possible over central and southeast IL.
Canadian high pressure settles into IL Monday returning dry and
colder weather. A northern stream short wave races ese into Great
Lakes region late Tue and Tue night bringing small chances of light
snow with best chances ne of central IL. Another Canadian high
pressure settles into region by Thu brining in even colder air. So
after above normal temps overall since mid Jan, next week (first
week of Feb) looks like temps will likely be below normal.
&&
.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
ISSUED AT 1206 PM CST THU JAN 29 2015
The main aviation concerns will be with MVFR ceilings and the
strong northwest wind gusts across central and eastern Illinois.
The latest satellite loop and surface observations indicated a
large area of MVFR ceilings across all of Illinois and much of
Iowa. The main question is the advancement of an area of partial
clearing from southern MN and central IA, and when the MVFR
ceilings will dissipate. The vast majority of short range models
indicate that a shortwave trough axis will swing through central
and eastern IL late this evening. However, most of these same
models including the NAM, RAP and HRRR indicate that there will be
plenty of low level moisture trapped below a stout inversion. This
would keep at least broken MVFR ceilings in the area through the
night and into much of Friday morning. Will follow this line of
thinking as it can be very difficult to erode low level clouds
this time of year.
The tight pressure gradient will keep northwest winds gusting
around 25-30 knots through the afternoon into early evening at
most TAF sites - particularly in east central Illinois. The
lessening impact of the surface low moving through the eastern
Great Lakes will result in diminishing wind in central IL late
this evening, and in eastern Illinois before daybreak.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Miller
SHORT TERM...Smith
LONG TERM...07
AVIATION...Miller
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
358 AM CST THU JAN 29 2015
.SHORT TERM...
358 AM CST
TODAY THROUGH FRIDAY NIGHT...
THE MAIN FORECAST CONCERNS THIS MORNING INVOLVE THE AREA OF LOW
PRESSURE CURRENTLY OVER WEST CENTRAL ILLINOIS...AND INCLUDE PRECIP
TIMING/TYPE...TEMPERATURE TRENDS...GUSTY WINDS...AND EVENTUALLY THE
POTENTIAL FOR SOME LAKE EFFECT SNOW SHOWERS OVER NORTHWEST INDIANA
TONIGHT INTO FRIDAY.
THE SURFACE LOW CENTER WAS JUST SOUTHWEST OF LASALLE/PERU ILLINOIS
AT 3 AM CST...WITH THE ASSOCIATED CYCLONIC WIND CIRCULATION PULLING
RELATIVELY MILD AIR NORTH ACROSS THE EASTERN 2/3 OF THE CWA.
CHALLENGING HOURLY TEMPERATURE FORECAST...AS READINGS MAY REACH 40
DEGREES IN THE SOUTHEAST EARLY THIS MORNING BEFORE THE LOW PASSES
AND SHIFTS WINDS TO THE NORTHWEST AND PULLS IN COLDER AIR. WITH THE
EXCEPTION OF A BAND OF RAIN SHOWERS LATE LAST EVENING...LITTLE
PRECIPITATION HAS BEEN OCCURRING WITH THIS SYSTEM EXCEPT NORTH/EAST
OF THE FORECAST AREA OVERNIGHT. REGIONAL RADAR MOSAIC HAS BEEN
DEPICTING PERSISTENT LIGHT RETURNS BEHIND THE LOW/COLD FRONT HOWEVER
WHERE SOME OCCASIONAL DRIZZLE OR "UNKNOWN" PRECIP HAS BEEN REPORTED.
HIGH-RES GUIDANCE TRENDS CONTINUE TO INDICATE SOME VERY LIGHT
PRECIPITATION IS POSSIBLE ACROSS THE AREA THIS MORNING...WITH
FORECAST SOUNDINGS INDICATING MAINLY DRIZZLE WITH SATURATION MAINLY
IN LOW LEVELS AS COLDER AIR MOVES IN...THOUGH A BRIEF PERIOD OF
MID-LEVEL MOISTURE WITH RAGGED DEFORMATION AREA ALONG WEST/NORTHWEST
SIDE OF THE LOW COULD BRIEFLY INTRODUCE ICE INTO LOW LEVELS IN A
SEEDER-FEEDER SITUATION WHICH COULD RESULT IN A MIX OF DRIZZLE/LIGHT
RAIN AND LIGHT SNOW THIS MORNING...THOUGH NOT EXPECTING ANY REAL
MEASURABLE PRECIPITATION OR SNOW WITH THIS. STRONG DRYING ABOVE THE
BOUNDARY LAYER FROM THE NORTHWEST BY MIDDAY SHOULD ALLOW ANY LIGHT
PRECIP TO END FROM WEST TO EAST THROUGH THE LATE MORNING AND MIDDAY
HOURS.
WINDY CONDITIONS WILL DEVELOP DURING THE MORNING AS COLD ADVECTION
STEEPENS OUR LOW LEVEL LAPSE RATES IN THE TIGHT PRESSURE GRADIENT
WEST OF THE LOW. FORECAST SOUNDINGS INDICATE GUSTS AROUND 35 MPH
WILL BE POSSIBLE FROM MID-MORNING THROUGH THE AFTERNOON BEFORE WINDS
GRADUALLY DIMINISH TONIGHT. A QUICK NOTE OF TEMPERATURES WEST OF THE
LOW THIS MORNING INDICATES READINGS DO NOT DROP OFF TOO DRAMATICALLY
AND WILL LIKELY SEE STEADY TEMPS FOR THE MOST PART UNTIL LATE TODAY.
(EXCEPT IN THE SOUTHEAST WHERE TEMPS APPROACH 40 THIS MORNING...WILL
LIKELY SETTLE BACK TO THE MID 30S THERE).
AS FOR LAKE EFFECT TONIGHT...LOW LEVEL WINDS FROM THE
NORTH-NORTHWEST (AROUND 340 DEG) SUPPORT AN INITIAL CONVERGENCE ZONE
ALONG THE SOUTHWEST MICHIGAN SHORE THIS AFTERNOON AND EARLY THIS
EVENING...THOUGH OUR LOCALLY RUN ARW MODEL DOES VEER WINDS LATER
TONIGHT AND BRINGS CONVERGENT BAND INTO PORTER COUNTY LATE TONIGHT
INTO EARLY FRIDAY. LARGER SCALE FLOW BACKS MORE WESTERLY FRIDAY
AFTERNOON WHICH SHOULD PUSH ANY LINGERING SNOW SHOWERS BACK EAST OF
PORTER COUNTY BY MID/LATE FRIDAY AFTERNOON. THERMODYNAMICS ARE NOT
SPECTACULAR...THOUGH VARIOUS MODEL FORECAST SOUNDINGS DEVELOP
LAKE-850 HPA DELTA-T AROUND 17C EARLY FRIDAY WITH INVERSION HEIGHTS
5000-6000 FT BEFORE CONDITIONS GRADUALLY WANE LATER FRIDAY MORNING.
DEPENDING UPON HOW LONG THE BAND BACKS UP INTO PORTER/EASTERN LAKE
COUNTIES WILL MODULATE THE SNOWFALL ACCUMULATION POTENTIAL...THOUGH
A FEW INCHES ARE CERTAINLY POSSIBLE IF THE BAND DOES HANG UP THERE
FOR A WHILE LATE TONIGHT/EARLY FRIDAY...BEFORE EXPANSIVE SURFACE
HIGH BUILDS ACROSS THE AREA THROUGH FRIDAY NIGHT.
RATZER
&&
.LONG TERM...
358 AM CST
SATURDAY THROUGH WEDNESDAY...
THE MAIN CONCERN IN THE EXTENDED PERIOD CONTINUES TO BE THE
POTENTIAL FOR SOME ACCUMULATING SNOW OVER THE WEEKEND...ESPECIALLY
ACROSS THE SOUTHERN PART OF THE CWA LATE SATURDAY NIGHT AND SUNDAY.
GLOBAL RUNS CONTINUE TO SHOW AGREEMENT IN FIRST SAGGING A COLD FRONT
SOUTH ACROSS THE AREA SATURDAY...THEN WITH THE AMPLIFICATION OF AN
UPPER TROUGH OVER THE REGION WITH SUBSEQUENT SURFACE LOW DEVELOPMENT
OVER THE LOWER MISSISSIPPI VALLEY. WHILE THE TRACK OF THE SURFACE
LOW HAS TRENDED SOUTH OVER THE PAST FEW RUNS (NOW FROM THE LOWER
MISS VALLEY TO THE MID-ATLANTIC OR CAROLINA COAST BY MONDAY
MORNING)...NORTHERN PERIPHERY OF DEFORMATION BAND SNOW ACROSS
CENTRAL ILLINOIS/INDIANA WOULD STILL AFFECT SOUTHERN COUNTIES OF THE
LOT CWA AT THIS POINT. IN ADDITION...INCREASING NORTH-NORTHEAST
WINDS NORTH OF THE LOW TRACK COMBINED WITH ARCTIC AIR INTRUSION
BEHIND SATURDAY COLD FRONT COULD VERY WELL LEAD TO LAKE
EFFECT/ENHANCED SNOW SHOWERS INTO THE CHICAGO METRO AREA. SO...
WHILE MANY DETAILS REMAIN TO BE WORKED OUT HAVE MAINTAINED DECENT
CHANCE POPS FOR MEASURABLE SNOW ACROSS THE FORECAST AREA FOR THE
WEEKEND. STILL LOOKS COLD BEYOND THE WEEKEND INTO NEXT WEEK WITH
DEEP TROUGH ACROSS THE EAST...THOUGH PATTERN CONTINUES TO BE
PROGRESSIVE IN LONGER RANGE GUIDANCE SOLUTIONS WHICH KEEPS IT FROM
STICKING AROUND TOO LONG.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 09Z...
* SOUTH-SOUTHEAST WINDS TURNING NORTHWEST BY 13Z WITH A BRIEF
PERIOD OF LIGHT AND VARIABLE WINDS POSSIBLE FROM 10Z TO 13Z.
NORTHWEST GUSTS OF 30-35 KT FROM MID MORNING THROUGH THE
AFTERNOON.
* LOW MVFR CIGS AND POSSIBLY MVFR VISIBILITY ARRIVING NEAR OR
SHORTLY AFTER DAYBREAK. IFR CIGS POSSIBLE IFR FOR A FEW HOURS
THIS MORNING.
* DRIZZLE POSSIBLE 12Z-14Z...THEN A BRIEF PERIOD OF LIGHT
RAIN/SNOW SHOWERS LIKELY MID-MORNING.
//DISCUSSION...UPDATED 06Z...
LOW PRESSURE ACROSS SOUTHEAST IOWA AT 530Z WILL MOVE CLOSE TO MDW
AND GYY BY 12Z AND THEN ONTO LOWER MICHIGAN THROUGH THE REST OF
THURSDAY MORNING. BECAUSE OF THIS PATH...A TEMPORARY PERIOD OF
LIGHTER VARIABLE WINDS IS BECOMING MORE PROBABLE AT CHICAGO AREA
TAF SITES BETWEEN 10Z-13Z OR SO. BEHIND THE LOW PASSAGE ON
THURSDAY MORNING...THE WINDS WILL TURN TO THE NORTH-NORTHWEST AND
THEN NORTHWEST WITH SPEEDS QUICKLY INCREASING. OCCASIONAL GUSTS OF
30 TO 35 KT LOOK PROBABLE FOR DURING THE DAY THURSDAY.
SPOTTY LIGHT RAIN SHOWERS OR DRIZZLE WILL BE SEEN UNTIL THE STRONG
COLD ADVECTION ARRIVES. CIGS WILL ALSO DROP LOWER AS THE SYSTEM
CENTER PASSES. BASED ON UPSTREAM OBSERVATIONS...1000-1500 FT CIGS
ARE HIGHLY LIKELY WITH POTENTIAL FOR A PERIOD OF 600-900 FT CIGS
DURING THE MORNING. IN ADDITION...AS THE SYSTEM BEGINS TO
INTENSITY OVER LOW MICHIGAN...A BACKSIDE DEVELOPING AREA OF LIGHT
RAIN AND/OR SNOW IS EXPECTED TO MOVE CLOSE TO OR OVER THE TAF
SITES. THIS SHOULD LIKELY LAST NO LONGER THAN 90 MINUTES AT ANY
ONE SITE AND NO ACCUMULATION IS EXPECTED. MVFR CIGS ARE LIKELY TO
LAST INTO THURSDAY EVENING.
//ORD AND MDW CONFIDENCE...UPDATED 09Z...
* WHILE LOW ON SPECIFIC WIND DIRECTION 10Z-13Z...HIGH CONFIDENCE
THAT SPEEDS WILL BE LESS THAN 10 KT IN THAT PERIOD. HIGH
CONFIDENCE IN WINDS AFTER 13Z.
* HIGH IN MVFR CIGS AND TIMING. MEDIUM IN CIG BASES AND THAT A
BRIEF PERIOD OF IFR WILL OCCUR.
* MEDIUM IN PERIOD OF MVFR VISIBILITY THIS MORNING.
* MEDIUM IN CHANCE FOR A BRIEF PERIOD OF MIXED PRECIP THIS
MORNING. HIGH IN NO SNOW ACCUMULATION OCCURRING.
//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...
FRIDAY...VFR. NORTHWEST WINDS.
SATURDAY...CHANCE OF SNOW AND IFR DURING THE NIGHT. SOUTHWEST
WINDS.
SUNDAY...SNOW AND IFR LIKELY. NORTHEAST WINDS.
MONDAY...CHANCE OF SNOW WITH MVFR LIKELY. IFR POSSIBLE. NORTHWEST
WINDS.
TUESDAY...SLIGHT CHANCE OF SNOW DURING THE NIGHT. SOUTHWEST WINDS.
MTF/MDB
&&
.MARINE...
205 AM CST
A PROGRESSIVE ACTIVE PATTERN WILL CONTINUE ACROSS THE GREAT LAKES
REGION INTO THE BEGINNING OF FEBRUARY. MOVING EASTWARD EARLY THIS
MORNING IS AN ELONGATED TROUGH WITH TWO LOW PRESSURE CENTERS
COMPOSING IT...ONE PASSING JUST SOUTH OF LAKE MICHIGAN AND ANOTHER
OVER EASTERN LAKE SUPERIOR. TOGETHER THESE WILL CONSOLIDATE LATER
TODAY AND DRIVE MORE FOCUSED AND STRENGTHENING COLD ADVECTION
OVER LAKE MICHIGAN. THIS WITHIN THE STRONG AND ADVECTING PRESSURE
GRADIENT WILL SUPPORT NORTHWEST TO NORTH GALES...EVEN 45 KT GUST
POTENTIAL ACROSS PARTS OF THE NORTH. THE ILLINOIS AND ESPECIALLY
THE INDIANA NEAR SHORES SHOULD AT LEAST EXPERIENCE PERIODIC GALE
GUSTS INTO THIS EVENING. COLDER TEMPERATURES WILL BE WORKING
SOUTHWARD ACROSS THE LAKE LATER TODAY AND TONIGHT. SUPPORT FOR
HEAVY FREEZING SPRAY REMAINS OVER MAINLY THE NORTH AND CONTINUE
THE WARNING THERE. WAVES ARE LIKELY TO BUILD TO 12-15 FT TONIGHT
AT DOWNSTREAM FETCH LOCATIONS ON THE EASTERN HALF OF THE LAKE.
WINDS WILL GRADUALLY DIMINISH OVERNIGHT INTO FRIDAY MORNING AND
MORE QUICKLY AFTERWARD AS HIGH PRESSURE MOVES OVER THE LAKE.
BEYOND...THERE LOOKS LIKE OPPORTUNITIES FOR AT LEAST 30 KT WINDS
NEXT WEEK. ONE OF THESE IS BEHIND A COLD FRONT SATURDAY AFTERNOON
AND MORE SO SATURDAY NIGHT. MORE 30 KT WIND POTENTIAL WOULD COME
POSSIBLY TUESDAY AS RETURN SOUTHWEST FLOW SPREADS BACK OVER THE
LAKE.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 AM THURSDAY.
GALE WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745...10 AM
THURSDAY TO 3 AM FRIDAY.
GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...9 AM THURSDAY TO 3 AM
FRIDAY.
HEAVY FREEZING SPRAY WARNING...LMZ261-LMZ362-LMZ364-LMZ366-
LMZ563-LMZ565-LMZ567-LMZ868...2 PM THURSDAY TO 3 AM FRIDAY.
&&
$$
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
330 AM CST Thu Jan 29 2015
.SHORT TERM...(Today)
ISSUED AT 329 AM CST THU JAN 29 2015
Low pressure centered just north of Moline at 08z/2am will continue
to push east and drag a cold front through our area this morning.
Warmest temperatures will be just ahead of the cold front early this
morning, and then we expect temperatures to fall off quickly just
behind the cold front during the remainder of the morning, and then
hold fairly steady this afternoon. Winds will be gusty again today
but this time out of the northwest with a few gusts of 35 to 40 mph
at times about an hour or two after frontal passage right along the
stronger surface pressure rises. Look for gusts in the 30 to 35 mph
range this afternoon.
Not seeing a lot of precip, other than some occasional very light
rain/drizzle out in Iowa and northern MO so will continue with
just a slight chance of light rain/snow this morning with POPs
decreasing from west to east this afternoon, and that would be
mainly across the north half of the forecast area. Latest
satellite data and upstream surface observations not showing much
hope for any clearing across our area in the near term. Forecast
soundings off the NAM-WRF showing a fairly strong subsidence
inversion setting up again in the wake of this system resulting in
quite a bit of low level moisture trapped beneath the inversion at
around 2500-3000 feet. As a result, we have backed off with any
decrease in cloud cover until later this evening and that may be
optimistic based on the latest (06z) forecast soundings off the
NAM.
&&
.LONG TERM...(Tonight through Wednesday)
ISSUED AT 329 AM CST THU JAN 29 2015
Short wave trof to exit east and se of IL early this evening as
Canadian high pressure over the Canadian Rockies settles into the
upper Midwest tonight. However an inversion will likely trap low
level clouds longer tonight and have trended the forecast slower
with decreasing low clouds from the west. Low clouds could linger
over ne counties into Friday morning especially near IN border.
Cooler lows tonight in upper teens to near 20F northern areas to mid
20s in southeast IL. Brisk nw winds 15-25 mph this evening to slowly
diminish during overnight into Friday morning as high pressure
settles into IL on Friday. Highs Friday 29-35F with coolest readings
from I-74 ne with partly to mostly sunny skies.
High pressure settles into the Ohio river valley Friday evening and
into central Appalachians by dawn Sat and continue fair/dry weather
through at least Saturday morning. Lows Friday night in upper teens
and lower 20s again. Milder highs Sat in upper 30s and lower 40s
with mildest readings sw areas with ssw breezes. Clouds to increase
later Friday night into Sat ahead of next storm system with slight
chance of light rain/snow later Saturday afternoon west of I-55. Most
over central and especially eastern IL should still be dry through the
daytime hours on Saturday.
12Z Jan 28 forecast models trended further south with low pressure
system Sat night and Sunday, while 00Z Jan 29 forecast models have
trended back north with more phasing of southern and northern stream
upper level systems, along with higher snowfall amounts over central
and southeast IL. 00Z models have also trended colder with even
southeast IL looking like all snow with this eveng and mixed
precipitation south of I-64 toward the ohio river. Confidence is not
too high yet with this potentially high impact winter weather event
with extended period of overrunning snow developing Saturday night
and continue through Sunday before diminishing Sunday night. Several
inches of snow still appears possible over central and southeast IL.
Canadian high pressure settles into IL Monday returning dry and
colder weather. A northern stream short wave races ese into Great
Lakes region late Tue and Tue night bringing small chances of light
snow with best chances ne of central IL. Another Canadian high
pressure settles into region by Thu brining in even colder air. So
after above normal temps overall since mid Jan, next week (first
week of Feb) looks like temps will likely be below normal.
&&
.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
ISSUED AT 1143 PM CST WED JAN 28 2015
Low pressure currently centered over eastern Iowa will track across
north-central Illinois tonight, then into Michigan by Thursday
morning. A tight pressure gradient ahead of the low will continue
to provide gusty southeasterly winds that will gradually veer to
the southwest after midnight, before veering sharply to the northwest
after FROPA between 12z and 15z Thu. Forecast soundings remain
quite dry, although models are hinting at perhaps a few light
showers near the low track, so have included VCSH at the I-74
terminals Thursday morning. VFR conditions will prevail until the
front passes and winds become northwesterly, at which time MVFR
ceilings currently over the Dakotas and western Iowa will spill
southeastward into the area. Based primarily on HRRR timing, have
introduced MVFR ceilings at KPIA by 10z, then further east to KCMI
by 13z. Once the low clouds arrive, they will stick around through
Thursday afternoon. Winds will be quite strong as well, with
northwesterly gusts in the 25 to 30kt range.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Smith
LONG TERM...07
AVIATION...Barnes
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
208 AM CST THU JAN 29 2015
.UPDATE...
901 PM...EVENING UPDATE...WEAK UPPER WAVE MOVING ACROSS THE AREA
LATE THIS EVENING WITH LIGHT RETURNS SHOWING UP ON RADAR. PIA
REPORTED 10 MINUTES OF LIGHT RAIN AND EXPECT THIS ACTIVITY WILL
REMAIN SUFFICIENT TO PRODUCE SOME SPRINKLES OR VERY LIGHT RAIN AND
WILL HAVE SLIGHT CHANCE POPS FOR THE REST OF THIS EVENING. BACK
EDGE OF THE CLOUD COVER NOW PUSHING INTO NORTHWEST IL AND EXPECT A
FEW HOURS OF MOSTLY CLEAR GOING INTO THE EARLY MORNING HOURS.
TEMPS HOLDING STEADY NEAR OR JUST ABOVE FREEZING WITH A FEW SITES
WARMING A DEGREE OR SO IN THE PAST FEW HOURS. CAN/T COMPLETELY
RULE OUT A CHANCE OF LIGHT FREEZING RAIN BUT GIVEN THE EXPECTED
LIGHT/SPOTTY NATURE OF THE PRECIP AND TEMPS AT OR ABOVE
FREEZING...NOT EXPECTING ANY SIGNIFICANT ICING CONCERNS.
SURFACE LOW OVER SOUTH CENTRAL IA WILL MOVE EAST/NORTHEAST TO THE
FAR SOUTHERN END OF LAKE MICHIGAN THURSDAY MORNING. AS IT DOES...
IT WILL TUG LOWER CLOUDS ACROSS SOUTHERN MN AND SOUTHERN WI SOUTH
ACROSS THE AREA...THUS CLEARING SHOULD BE RATHER SHORT LIVED. AS
THESE LOWER CLOUDS ARRIVE...THERE WILL LIKELY BE SOME PATCHY
DRIZZLE OR POTENTIALLY SOME LIGHT RAIN...BUT MODELS CONTINUE TO
DOWNPLAY PRECIP/QPF OVERNIGHT. ASSUMING THIS DRIZZLE OR VERY LIGHT
RAIN DOES MATERIALIZE...WILL NEED TO WATCH TEMP TRENDS ONCE CLOUDS
CLEAR TO SEE IF THEY DROP BACK TO NEAR FREEZING...THUS POTENTIAL
ICING CONCERNS...WHICH WOULD MAINLY BE ACROSS THE NORTHERN HALF OR
THIRD OF THE CWA. AT THIS POINT...WILL BE MAINTAINING AIR TEMPS AT
OR ABOVE FREEZING OVERNIGHT. CMS
&&
.SHORT TERM...
340 PM CST
THROUGH FRIDAY...
MAIN FORECAST CONCERNS ARE WITH PRECIP POTENTIAL AND TEMP TRENDS
TONIGHT...LINGERING LAKE EFFECT SNOW SHOWERS THURSDAY INTO EARLY
FRIDAY...AND POSSIBLE ACCUMULATING SNOW THIS WEEKEND.
RELATIVELY QUIET CONDITIONS THIS AFTERNOON...WITH INCREASING
MID/HIGH LEVEL CLOUD COVER OUT AHEAD OF APPROACHING SYSTEM OVER
THE CENTRAL PLAINS. SURFACE LOW OVER EASTERN NEBRASKA WILL
CONTINUE TO SHIFT EAST TOWARDS THE AREA THIS EVENING AS MID/UPPER
LEVEL TROUGH SWING EAST THROUGH THE CENTRAL CONUS. AS THIS
OCCURS...STRONG ISENTROPIC ASCENT OUT AHEAD OF IT WILL GRADUALLY
SHIFT EAST ACROSS THE CWA LATER THIS EVENING. INITIAL DRY
CONDITIONS IN PLACE WILL NEED TO BE OVERCOME THIS EVENING BUT
INCREASING ASCENT THIS EVENING SHOULD ALLOW FOR THE COLUMN TO
SATURATE...WITH DEVELOPING PRECIP TO THEN SPREAD OVER THE REGION.
GUIDANCE DOES VARY WITH REGARDS TO WHEN THE DRIER AIR WILL BE
OVERCOME...WITH SOME INDICATING THIS WILL OCCUR AS EARLY AS THIS
EVENING AND WITH OTHERS POINTING AT THE DEVELOPMENT AFTER THE
MIDNIGHT TIME FRAME. HAVE TRENDED TOWARDS THE PREVIOUS FORECAST
WITH THE POSSIBILITY OF PRECIP DEVELOPING BY MID TO LATE
EVENING...STRAYING AWAY FROM THE DRIER GUIDANCE. PERSISTENT
FORCING THROUGH THIS EVENING SHOULD ALLOW FOR AT LEAST LIGHT
DEVELOPMENT ACROSS A GOOD PORTION OF THE CWA. RAIN DOES APPEAR TO
BE THE PREDOMINANT PRECIP TYPE OVERNIGHT TONIGHT AS STRONG WARM
ADVECTION OUT AHEAD OF THIS SYSTEM OCCURS...AND ESPECIALLY AS
SOUTHERLY FLOW CONTINUES TO RAMP UP AHEAD OF THE SURFACE LOW.
HOWEVER...DO ANTICIPATE FOR SOME SLIGHT COOLING OF THE CURRENT MID
30 TEMPS LATE THIS AFTERNOON INTO THE EARLY EVENING BEFORE A
STEADY TEMP RISE IS OBSERVED FOR ALL AREAS. IF THE PRECIP WERE TO
OCCUR SLIGHTLY EARLIER THAN CURRENT THINKING...THEN A BETTER
CHANCE FOR LIGHT FREEZING RAIN COULD OCCUR. THIS TIME FRAME WOULD
BE IN THE 1-4Z PERIOD WHERE LOW TEMPS IN THE LOW 30S WILL BE
OBSERVED...BEFORE A RISE TO THE MID TO UPPER 30S WILL OCCUR. THIS
TEMP RISE SHOULD LIMIT ANY FREEZING RAIN POTENTIAL TO A SMALL
SEVERAL HOUR WINDOW...WITH ONCE AGAIN RAIN THEN EXPECTED EVEN INTO
EARLY THURSDAY MORNING.
EXPECT BEST DEVELOPMENT TO OCCUR MORE TOWARDS EARLY THURSDAY
MORNING INTO MID MORNING AS SURFACE LOW AND SURFACE BOUNDARIES
PUSH THROUGH...WITH THE RAIN BECOMING ALL SNOW THROUGH MID TO LATE
MORNING. PRECIP SHIELD SHOULD BE EXITING DURING THIS TRANSITION
WITH ANY SNOW ACCUMULATION EXPECTED TO NO MORE THAN A COUPLE OF
TENTHS OF AN INCH. LIGHT SNOW COULD LINGER INTO NORTHWEST INDIANA
AS LAKE EFFECT POTENTIAL INCREASES...BUT BETTER FOCUS WILL
INITIALLY BE FURTHER TO THE EAST. AS COLDER AIR SPILLS SOUTH AND
BOUNDARY LAYER FLOW SHIFTS...FOCUS FOR BETTER LAKE EFFECT SNOW
DEVELOPMENT WILL MOVE INTO THE CWA...WITH THE PORTER COUNTY AREA
WITHIN THE CWA LIKELY OBSERVING THIS BEST DEVELOPMENT. BUILDING
HIGH PRESSURE WITH BACKING LOW LEVEL FLOW WILL GRADUALLY HELP THIS
SNOW TO DIMINISH WHILE SHIFTING EAST THROUGHOUT THE DAY ON FRIDAY.
RODRIGUEZ
&&
.LONG TERM...
340 PM CST
FRIDAY NIGHT THROUGH WEDNESDAY...
MAIN CONCERN TO START THE PERIOD WILL BE FOR THE POTENTIAL FOR
ACCUMULATING SNOW SATURDAY NIGHT INTO SUNDAY. THERE STILL APPEARS
TO BE THE POTENTIAL FOR SNOW DURING THIS PERIOD...BUT WITH
CONFIDENCE OF THIS POTENTIAL FOR THE CWA LOWERING TODAY. PREVIOUS
CONSISTENCY AMONG VARYING GUIDANCE IS NOT PRESENT TODAY...WITH
GUIDANCE RANGING FROM LIGHT ACCUMULATIONS TO VERY LITTLE TO NONE.
AM NOT TOTALLY CONVINCED IN THE SHIFT WITH THE STORM TRACK AND
POTENTIAL PRECIP ADVERTISED TODAY AND DID NOT CHANGE POPS TOO MUCH
DURING THIS PERIOD...AS GUIDANCE COULD SHIFT BACK ONCE AGAIN.
WOULD LIKE TO SEE CONSISTENCY OF THIS POTENTIAL BEFORE POPS ARE
LOWERED. CURRENTLY HAVE THE HIGHEST POPS FOR THE SOUTHERN HALF OF
THE CWA...WITH A MORE FAVORED SOUTHERLY TRACK OF THIS SYSTEM.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* SOUTH-SOUTHEAST WINDS TURNING NORTHWEST BY 13Z WITH A BRIEF
PERIOD OF VARIABLE WINDS BECOMING MORE PROBABLE 10Z-13Z.
NORTHWEST GUSTS OF 30-35 KT FROM MID THURSDAY MORNING THROUGH
THE AFTERNOON.
* LOW MVFR CIGS AND MVFR VISIBILITY ARRIVING NEAR DAYBREAK AND
THEN POSSIBLY IFR FOR A FEW HOURS THURSDAY MORNING.
* A FEW RAIN SHOWERS AND DRIZZLE POSSIBLE PRIOR TO 13Z...THEN A
BRIEF PERIOD OF LIGHT RAIN/SNOW SHOWERS LIKELY MID-MORNING
THURSDAY.
//DISCUSSION...UPDATED 06Z...
LOW PRESSURE ACROSS SOUTHEAST IOWA AT 530Z WILL MOVE CLOSE TO MDW
AND GYY BY 12Z AND THEN ONTO LOWER MICHIGAN THROUGH THE REST OF
THURSDAY MORNING. BECAUSE OF THIS PATH...A TEMPORARY PERIOD OF
LIGHTER VARIABLE WINDS IS BECOMING MORE PROBABLE AT CHICAGO AREA
TAF SITES BETWEEN 10Z-13Z OR SO. BEHIND THE LOW PASSAGE ON
THURSDAY MORNING...THE WINDS WILL TURN TO THE NORTH-NORTHWEST AND
THEN NORTHWEST WITH SPEEDS QUICKLY INCREASING. OCCASIONAL GUSTS OF
30 TO 35 KT LOOK PROBABLE FOR DURING THE DAY THURSDAY.
SPOTTY LIGHT RAIN SHOWERS OR DRIZZLE WILL BE SEEN UNTIL THE STRONG
COLD ADVECTION ARRIVES. CIGS WILL ALSO DROP LOWER AS THE SYSTEM
CENTER PASSES. BASED ON UPSTREAM OBSERVATIONS...1000-1500 FT CIGS
ARE HIGHLY LIKELY WITH POTENTIAL FOR A PERIOD OF 600-900 FT CIGS
DURING THE MORNING. IN ADDITION...AS THE SYSTEM BEGINS TO
INTENSITY OVER LOW MICHIGAN...A BACKSIDE DEVELOPING AREA OF LIGHT
RAIN AND/OR SNOW IS EXPECTED TO MOVE CLOSE TO OR OVER THE TAF
SITES. THIS SHOULD LIKELY LAST NO LONGER THAN 90 MINUTES AT ANY
ONE SITE AND NO ACCUMULATION IS EXPECTED. MVFR CIGS ARE LIKELY TO
LAST INTO THURSDAY EVENING.
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* WHILE LOW ON SPECIFIC WIND DIRECTION 10Z-13Z...HIGH CONFIDENCE
THAT SPEEDS WILL BE LESS THAN 12 KT IN THAT PERIOD. HIGH
CONFIDENCE IN WINDS AFTER 13Z.
* HIGH IN MVFR CIGS AND TIMING. MEDIUM IN CIG BASES AND THAT A
BRIEF PERIOD OF IFR WILL OCCUR.
* MEDIUM IN PERIOD OF MVFR VISIBILITY THURSDAY MORNING.
* MEDIUM IN CHANCE FOR A BRIEF PERIOD OF MIXED PRECIP THURSDAY
MORNING. HIGH IN NO SNOW ACCUMULATION OCCURRING.
//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...
FRIDAY...VFR. NORTHWEST WINDS.
SATURDAY...CHANCE OF SNOW AND IFR DURING THE NIGHT. SOUTHWEST
WINDS.
SUNDAY...SNOW AND IFR LIKELY. NORTHEAST WINDS.
MONDAY...CHANCE OF SNOW WITH MVFR LIKELY. IFR POSSIBLE. NORTHWEST
WINDS.
TUESDAY...SLIGHT CHANCE OF SNOW DURING THE NIGHT. SOUTHWEST WINDS.
MTF/MDB
&&
.MARINE...
205 AM CST
A PROGRESSIVE ACTIVE PATTERN WILL CONTINUE ACROSS THE GREAT LAKES
REGION INTO THE BEGINNING OF FEBRUARY. MOVING EASTWARD EARLY THIS
MORNING IS AN ELONGATED TROUGH WITH TWO LOW PRESSURE CENTERS
COMPOSING IT...ONE PASSING JUST SOUTH OF LAKE MICHIGAN AND ANOTHER
OVER EASTERN LAKE SUPERIOR. TOGETHER THESE WILL CONSOLIDATE LATER
TODAY AND DRIVE MORE FOCUSED AND STRENGTHENING COLD ADVECTION
OVER LAKE MICHIGAN. THIS WITHIN THE STRONG AND ADVECTING PRESSURE
GRADIENT WILL SUPPORT NORTHWEST TO NORTH GALES...EVEN 45 KT GUST
POTENTIAL ACROSS PARTS OF THE NORTH. THE ILLINOIS AND ESPECIALLY
THE INDIANA NEAR SHORES SHOULD AT LEAST EXPERIENCE PERIODIC GALE
GUSTS INTO THIS EVENING. COLDER TEMPERATURES WILL BE WORKING
SOUTHWARD ACROSS THE LAKE LATER TODAY AND TONIGHT. SUPPORT FOR
HEAVY FREEZING SPRAY REMAINS OVER MAINLY THE NORTH AND CONTINUE
THE WARNING THERE. WAVES ARE LIKELY TO BUILD TO 12-15 FT TONIGHT
AT DOWNSTREAM FETCH LOCATIONS ON THE EASTERN HALF OF THE LAKE.
WINDS WILL GRADUALLY DIMINISH OVERNIGHT INTO FRIDAY MORNING AND
MORE QUICKLY AFTERWARD AS HIGH PRESSURE MOVES OVER THE LAKE.
BEYOND...THERE LOOKS LIKE OPPORTUNITIES FOR AT LEAST 30 KT WINDS
NEXT WEEK. ONE OF THESE IS BEHIND A COLD FRONT SATURDAY AFTERNOON
AND MORE SO SATURDAY NIGHT. MORE 30 KT WIND POTENTIAL WOULD COME
POSSIBLY TUESDAY AS RETURN SOUTHWEST FLOW SPREADS BACK OVER THE
LAKE.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 11 AM THURSDAY.
GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-LMZ742-
LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-
LMZ874-LMZ876-LMZ878...11 AM THURSDAY TO 3 AM FRIDAY.
HEAVY FREEZING SPRAY WARNING...LMZ261-LMZ362-LMZ364-LMZ366-
LMZ563-LMZ565-LMZ567-LMZ868...2 PM THURSDAY TO 3 AM FRIDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1143 PM CST Wed Jan 28 2015
.UPDATE...
ISSUED AT 705 PM CST WED JAN 28 2015
00z/6pm surface analysis shows 1005mb low over western Iowa with
warm frontal boundary extending southward into Missouri.
Temperatures to the west of the warm front are currently in the
60s across Kansas/western Missouri, while readings further east
across central Illinois remain in the 30s and 40s. As the low
tracks into north-central Illinois, the warm front will push
eastward across the area this evening. While both the 00z KILX and
KDVN upper air soundings remain quite dry, latest radar mosaic
shows a narrow band of weak echoes developing ahead of the front.
High-res model output remains dry until the boundary pushes
further east into Indiana after midnight. Will however carry a
chance for sprinkles across the western half of the KILX CWA this
evening, then further east into east-central Illinois after
midnight as the boundary progresses across the area. Temperatures
will remain nearly steady or even rise a few degrees overnight as
gusty southeasterly winds gradually veer to the southwest. Once
the low pushes into Michigan, strong/gusty northwesterly winds
will develop by Thursday morning. In addition, low clouds
currently across the Dakotas will spill southward into the area.
May even see a few light rain/snow showers on the back side of the
departing system Thursday morning, particularly along/north of the
I-74 corridor.
&&
.SHORT TERM...(Tonight)
ISSUED AT 329 PM CST WED JAN 28 2015
A low pressure system currently centered over western Iowa will
track eastward across northern Illinois from around midnight to 6
a.m. tonight. As it does so, a warm frontal boundary followed by a
cold front will push across central Illinois in quick succession.
The warm front will cause temperatures to remain steady or even rise
slightly through much of the night, with primarily upper 30s and
lower 40s expected, followed by little increase in temperatures
after sunrise as the cold front pushes east across the area. This
system will be relatively moisture starved, so precipitation amounts
are expected to be very light. A potent surface pressure gradient
will be present with this system, keeping breezy winds going through
the night in the neighborhood of 15 to 20 mph with some higher
gusts. Winds will gradually turn from SSE this afternoon to SSW
overnight, shifting abruptly to northwest after the cold frontal
passage.
&&
.LONG TERM...(Thursday through Wednesday)
ISSUED AT 329 PM CST WED JAN 28 2015
Main concern today is the system over the weekend.
Morning upper air shows weak wave to move through tonight. Then
continued general northwest flow aloft as a cutoff low in the
southwest begins to drift to the east. A piece of shortwave energy
comes out from the southwest on Saturday and develops overrunning
pcpn Saturday night, as another wave in the northwest flow tracks to
the southeast into the area for Sunday. The result is a prolonged
period of light lift over the area Saturday night into Sunday
evening, which will produce light pcpn. Temperatures will be cold
enough for all over cwa but the far southeast to result in all snow
most of the period. At this time, lift seems to be light and just
the prolonged period from the 2 systems causing the pcpn. Will still
have to watch it as periods near to see if lift increases and thus
the resultant amounts. Kept amounts similar in the grids as previous
run at this time.
&&
.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
ISSUED AT 1143 PM CST WED JAN 28 2015
Low pressure currently centered over eastern Iowa will track across
north-central Illinois tonight, then into Michigan by Thursday
morning. A tight pressure gradient ahead of the low will continue
to provide gusty southeasterly winds that will gradually veer to
the southwest after midnight, before veering sharply to the northwest
after FROPA between 12z and 15z Thu. Forecast soundings remain
quite dry, although models are hinting at perhaps a few light
showers near the low track, so have included VCSH at the I-74
terminals Thursday morning. VFR conditions will prevail until the
front passes and winds become northwesterly, at which time MVFR
ceilings currently over the Dakotas and western Iowa will spill
southeastward into the area. Based primarily on HRRR timing, have
introduced MVFR ceilings at KPIA by 10z, then further east to KCMI
by 13z. Once the low clouds arrive, they will stick around through
Thursday afternoon. Winds will be quite strong as well, with
northwesterly gusts in the 25 to 30kt range.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Barnes
SHORT TERM...Onton
LONG TERM...Goetsch
AVIATION...Barnes
AREA FORECAST DISCUSSION
NWS DES MOINES IA
315 PM CST THU JAN 29 2015
.SHORT TERM /TONIGHT/...
ISSUED AT 315 PM CST THU JAN 29 2015
MAIN FORECAST CONCERN DEALT WITH LINGERING STRATUS DECK
AND TEMPERATURES AS A RESULT OF THE LINGERING CLOUD COVER. LEANED
TOWARD THE NAM/RAP/HRRR FOR CLOUD COVER AND LOW LEVEL RH THIS
EVENING. SOUNDINGS SUGGEST THE INVERSION CONTINUES THROUGH FRIDAY
MORNING AND POTENTIALLY TRAPPING THE LOW LEVEL MOISTURE/STRATUS OVER
CENTRAL IOWA DURING MUCH OF THE NIGHT. THERE IS A DECENT BREAK IN
THE CLOUD DECK OVER NORTH-CENTRAL IOWA AND INTO SOUTHERN MINNESOTA
AS OF 21Z...AND THE HRRR HAS SOMEWHAT PICKED UP ON THIS TREND AND
SLOWLY ERODES THE STRATUS BY AROUND 05Z ACROSS IOWA/MINNESOTA. HAVE
STRATUS SLOWLY ERODING DURING THE EVENING HOURS WITH THE NORTHEAST
SLOWEST TO CLEAR OUT.
CAA CONTINUES THROUGHOUT MUCH OF THE NIGHT BEFORE THE SURFACE RIDGE
SLIDES INTO NORTHERN IOWA FRIDAY MORNING AND FINALLY ALLOWING THE
WINDS TO BECOME LIGHT AND VARIABLE. SO ANY RADIATIONAL COOLING WILL
BE CLOSER TO SUNRISE. WITH THE TEMPERATURES REMAINING FAIRLY COLD
THIS AFTERNOON...LEANED TOWARD THE RAP FOR LOWS TONIGHT AS IT SEEMED
TO HAVE A BETTER HANDLE ON TEMP AND CLOUD COVER TRENDS.
.LONG TERM /FRIDAY THROUGH THURSDAY/...
ISSUED AT 315 PM CST THU JAN 29 2015
MUCH OF THE LONG TERM FORECAST WILL BE DOMINATED BY BROAD
NORTHWEST FLOW AND A SERIES OF WAVES MOVING THROUGH THE FLOW.
SURFACE RIDGING WILL BE ACROSS THE STATE AT THE BEGINNING OF THE
LONGER TERM TOMORROW MORNING WITH FRIDAY BEING THE BEST DAY OUT OF
REMAINDER OF THE FORECAST. WARM ADVECTION WILL INCREASE BY LATER
IN THE DAY AS SOUTHERLY SURFACE FLOW RESUMES AND READINGS ONCE
AGAIN ABOVE NORMAL. A DECENT PRESSURE GRADIENT KEEPING WINDS UP ON
FRIDAY NIGHT ALONG WITH INCREASING CLOUDINESS WILL HELP KEEP
TEMPERATURES QUITE WARM OVERNIGHT. MAY BEGIN TO SEE SOME LIGHT
PRECIPITATION IN THE FAR SOUTHWEST TOWARD DAYBREAK BUT THE BULK OF
THE SYSTEM WILL COME IN LATER PERIODS.
MOVING INTO THE WEEKEND...ALL FOCUS SHIFTS TO A SHORTWAVE TOPPING
THE WESTERN RIDGE AND ITS INTERACTION WITH A VERY MOIST UPPER LOW
ACROSS THE SOUTHWEST UNITED STATES. THE 12Z MODELS ARE BEGINNING
TO CLUSTER AROUND A SOLUTION OF DROPPING THE NORTHERN SHORTWAVE
SOUTHEAST WITH SUFFICIENT AMPLITUDE TO BRING THE MOISTURE PLUME
FAR ENOUGH NORTH TO IMPACT IOWA...AT LEAST THE SOUTHERN HALF OR
SO. INITIALLY...A SHORTWAVE THAT PASSES THROUGH THE GREAT LAKES
AREA FRIDAY NIGHT WILL SEND A COLD FRONT SOUTHWARD THRU THE
FORECAST AREA ON SATURDAY. MEANWHILE..INCREASING ISENTROPIC LIFT
AND MOISTURE ADVECTION WILL LEAD TO PRECIPITATION DEVELOPMENT
ACROSS SOUTHERN IOWA ON SATURDAY MORNING AHEAD OF THE BOUNDARY.
THE PRECIPITATION WILL LIKELY BE RAIN IN FAR SOUTHERN IOWA WITH
TEMPERATURES IN THE MID TO UPPER 30S. HOWEVER...A TRANSITION TO
SNOW IS LIKELY BY I80 OR HWY30 AS COLDER AIR IS ENCOUNTERED WITH
THE SOUTHWARD MOVING BOUNDARY. FORCING WILL SUSTAIN AND INCREASE
INTO SATURDAY NIGHT WITH DECENT MID LEVEL FRONTOGENETICAL FORCING
ACROSS THE SOUTHERN IOWA. ANY RAIN IN THE SOUTH ON SATURDAY WILL
TRANSITION TO SNOW IN THE EVENING AS COLD AIR CONTINUES TO DEEPEN
AND SPREAD SOUTHWARD BEHIND THE BOUNDARY. BY LATE SATURDAY NIGHT
INTO SUNDAY...DECENT MID LEVEL FORCING FROM APPROACHING SOUTHEAST
MOVING SHORTWAVE WILL HELP SNOW TO CONTINUE DURING THE DAY.
EVENTUALLY...THE FORCING WILL SHIFT TO THE EAST BY LATE IN THE DAY
WITH THE SNOW ENDING. THERE WILL BE A TIGHT GRADIENT OF SNOWFALL
ON NORTHERN SIDE OF PRECIPITATION SHIELD AND THEREFORE THE SNOW
AMOUNTS THAT ACCOMPANY THIS SYSTEM. AT THIS POINT...THE GRADIENT
APPEARS NEAR THE I80 CORRIDOR ALTHOUGH THIS WILL LIKELY MOVE WITH
SUBSEQUENT INFORMATION. GIVEN THE LONG DURATION OF THIS EVENT...IT
DOESNT APPEAR WARNING CRITERIA WILL BE MET...ALTHOUGH THE
COMBINATION OF WINDS AND SNOW MAY BE ENOUGH TO BOOST US INTO
WARNING. GIVEN THE CHANGES IN MODEL RUNS OVER THE PAST 36
HOURS...WILL WAIT ON ANY HEADLINES BUT BEGIN TO HIGHLIGHT MORE IN
THE HWO AND OTHER PRODUCTS. AMOUNTS OF AROUND 6 INCHES SEEM
POSSIBLE NEAR THE MO BORDER WITH 2-5 IN CENTRAL IOWA...AND AN INCH
OR LESS ACROSS THE NORTH.
MUCH COLDER AIR WILL FILTER INTO THE STATE FOR NEXT WEEK WITH A
SERIES OF SHORTWAVES PASSING THROUGH THE REGION. THIS WILL BRING
THE THREAT OF SNOW MONDAY NIGHT INTO TUESDAY WITH REINFORCING
SHOTS OF COLDER AIR.
&&
.AVIATION...29/18Z
ISSUED AT 1126 AM CST THU JAN 29 2015
MVFR CIGS LOOK TO PERSIST THROUGH THIS EVENING AND POTENTIALLY
INTO FRIDAY MORNING. CONFIDENCE IS HIGHER AT MCW/ALO AND EVEN OTM
FOR THE STRATUS TO LINGER A BIT LONGER...BUT CERTAINLY FOD AND DSM
EXTENDED THE MVFR CIGS TIME FRAME THROUGH LATE THIS EVENING.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...PODRAZIK
LONG TERM...COGIL
AVIATION...PODRAZIK
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
516 PM CST FRI JAN 30 2015
...UPDATED FOR AVIATION...
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 144 PM CST FRI JAN 30 2015
MOISTURE AND ISENTROPIC LIFT FROM I300 TO I308 APPEARS TO HAVE A
DECENT HANDLE OF THE LIGHT PRECIPITATION CURRENTLY SPREADING NORTH
ACROSS NORTHEAST NEW MEXICO AND THE PANHANDLE OF TEXAS. BASED ON
15Z AND 18Z VERIFICATION EARLIER TODAY WILL THEREFORE BE USING THE
THE I300 TO I308 LEVEL OVERNIGHT AS GUIDE FOR PRECIPITATION
CHANCES AND TIMING OF THIS PRECIPITATION AS IMPROVING MOISTURE
AND ISENTROPIC LIFT DEVELOPS ACROSS SOUTHWEST KANSAS. AT THIS TIME
BASED ON THE 12Z NAM AND LATEST RAP THE BETTER OPPORTUNITY FOR
WIDESPREAD PRECIPITATION OVER WESTERN KANSAS WILL BE FROM 03Z AND
09Z SATURDAY. AFTER 09Z ISENTROPIC DOWNGLIDE BEGINS TO DEVELOPS
ACROSS FAR WESTERN KANSAS SO THIS PRECIPITATION TO BEGIN TO TAPER
OFF NEAR THE COLORADO BORDER, OR AT LEAST BECOME MORE WIDELY
SCATTERED, EARLY FRIDAY MORNING.
AT THIS TIME MODEL SOUNDINGS ALONG WITH THE TOP DOWN APPROACH FOR
PRECIPITATION TYPE BOTH SUPPORT MAINLY A COLD RAIN EVENT FOR ALL
BUT PORTIONS OF NORTH CENTRAL AND FAR WESTERN KANSAS. IN THE NORTH
CENTRAL AND FAR WESTERN KANSAS THE ATMOSPHERE WILL BECOME COLD
ENOUGH FOR THE RAIN TO MIX WITH, OR BRIEFLY CHANGE OVER TO SNOW
AROUND DAYBREAK SATURDAY. BASED ON THE WARM SURFACE TEMPERATURES
AND RAINFALL OVERNIGHT LITTLE IF ANY SNOW ACCUMULATION IS EXPECTED
SHOULD A BRIEF PERIOD OF SNOW DEVELOPS.
AREAS OF FOG CAN ALSO BE EXPECTED LATE TONIGHT BASED ON THE
MOISTURE PROFILES NEAR THE SURFACE AND SOUTH SOUTHEASTERLY WIND AT
10 TO 15 MPH.
ON THURSDAY SOME BREAKS OF SUN WILL BE POSSIBLE ACROSS PORTIONS OF
WESTERN KANSAS EARLY IN THE DAY GIVEN THE ISENTROPIC DOWNGLIDE
DEVELOPING IN THIS AREA. AS A RESULT HAVE FAVORED THE WARMER
GUIDANCE FOR HIGHS SATURDAY AFTERNOON WEST OF HIGHWAY 283. FURTHER
EAST MOISTURE AND WEAK ISENTROPIC LIFT WILL CONTINUE SO WILL FAVOR
THE COOLER GUIDANCE GIVEN THE EXPECTED CLOUD COVER AND LIGHT
PRECIPITATION. AT THIS TIME HIGHS ARE EXPECTED TO VARY FROM NEAR
40 IN SOUTH CENTRAL KANSAS TO MID 40S IN WEST CENTRAL KANSAS.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 307 PM CST FRI JAN 30 2015
CONFIDENCE REMAINS RELATIVELY HIGH THAT THE SYSTEM WILL BE TOO SLOW
TO TURN COLD ENOUGH TO WARRANT A SIGNIFICANT ACCUMULATION OF SNOW
SATURDAY NIGHT. THE LATEST NAM AND ECMWF RUNS MAINTAIN OUR AREA ON
THE WARM SIDE OF THE SURFACE BOUNDARY UNTIL MID EVENING SATURDAY
WHEN HE FRONT IS ABLE TO BE FORCED THROUGH THE CENTRAL HIGH PLAINS
BY THE EXITING UPPER SYSTEM. EVENT HE IMMEDIATE POST FRONTAL AIR
APPEARS TOO WARM FOR SNOW ACCUMULATION, AND TEMPERATURES MAY NOT
FALL COLD ENOUGH ACROSS A LARGE ENOUGH PORTION OF THE AREA UNTIL
SUNDAY MORNING WHEN THE UPPER STRETCHING AND DEFORMATION HAS
BASICALLY CEASED.
THE COLDEST AIR IN A FEW WEEKS SHOULD THEN BE NOTICED BY SUNDAY
NIGHT AND EARLY MONDAY MORNING, AS STRONG SUBSIDENCE, DRIER AIR AND
GOOD LONGWAVE RADIATIONAL COOLING OF A COLDER DRIER AIRMASS IS
POSSIBLE. THE MOS OUTPUT FROM AT LEAST THE ECMWF AND NAM MODELS ARE
THE COLDEST WITH POTENTIAL FOR EVEN SINGLE DIGITS OVER CENTRAL
KANSAS EARLY MONDAY MORNING. THE CONSENSUS OF RAW MODEL OUTPUT WAS
NOT FAR FROM THESE COLDER SOLUTION AS WELL, WHICH WAS USED AS THE
OFFICIAL FORECAST. A STRONG WARMING TREND ON THE EAST SIDE OF AN
UPPER RIDGE WILL BE NOTICED HEADING INTO MID WEEK, WITH TEMPERATURES
LIKELY BACK INTO THE 60S BEFORE THE NEXT UPPER JET/SHORTWAVE/COLD
FRONT AFFECT THE CENTRAL PLAINS LATE WEDNESDAY AND THURSDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 508 PM CST FRI JAN 30 2015
CIGS WILL GRADUALLY LOWER TO MVFR BY 03-06Z WITH SOME LIGHT FOG
AND LIGHT RAIN AND VSBYS FROM 2-4SM. AREAS OF LIGHT SNOW MAY ALSO
MIX IN LATER TONIGHT. IFR CIGS ARE EXPECTED AFTER 09-12Z AS LOW
LEVELS SATURATE. EXPECT SOUTH TO SOUTHEAST WINDS OF 10-15KT.
SOUTHWESTERLY UPPER LEVEL FLOW WILL CONTINUE TO DRAW MOISTURE INTO
WESTERN KANSAS INTO SATURDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 34 44 31 36 / 80 60 60 10
GCK 34 46 31 37 / 70 50 50 0
EHA 33 44 33 40 / 80 50 50 0
LBL 34 44 34 41 / 80 60 60 10
HYS 33 42 26 29 / 80 50 60 0
P28 36 42 34 38 / 80 70 70 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BURGERT
LONG TERM...RUSSELL
AVIATION...KRUSE
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1115 AM CST Thu Jan 29 2015
.UPDATE...
Issued at 632 AM CST THU JAN 29 2015
The stronger wind gusts seems to be more isolated than earlier,
and overall obs show winds speeds below 30 MPH. With the RAP and
NAM showing the pressure gradient remaining at its current
magnitude or gradually weakening, will allow the wind advisory to
expire at 7 am. Nevertheless northwest winds of 15 to 25 MPH will
persist through much of the day.
&&
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 424 AM CST THU JAN 29 2015
A shortwave could be seen on the 08Z water vapor imagery passing
overhead into MO with a second shortwave moving southeast through SD
and WY. an upper level low pressure system was seen spinning well
off the Baja California coast and shortwaves within faster flow near
40N and 145W were moving towards the British Columbia coast. At the
surface, high pressure was building south through the central plains
causing gusty northwest winds from a tight pressure gradient. In
fact the gradient has been strong enough for sustained winds of
30 MPH and an occasional gust up to 45 MPH. Because of this, have
issued a wind advisory until 7 am. By then the pressure gradient
is expected to begin relaxing.
For today and tonight, the weather should remain relatively quiet
due to increasing dry air as the surface high pressure system
continues to move south. Because of this the shortwave over SD and
WY is not expected to do much in terms of sensible weather. However
subsidence behind this wave should help to erode away the low
stratus that has moved in, and think skies should clear out by the
late afternoon. Since there is not a lot of cold air behind this
front and models show the boundary layer mixing to almost 850MB,
think highs in the middle 40s looks reasonable. Lows tonight should
be a bit colder as the ridge axis moves in creating light winds with
clear skies. Expecting good radiational conditions, have adjusted
min temps down to around 20. Models show pretty high RH values
developing Friday morning suggestive of fog. Am not real confident
in fog formation since we have not had any meaningful precip lately
and soils remain very dry. Because of this think dewpoints are
likely to remain a couple degrees cooler than the air temp.
.LONG TERM...(Friday through Wednesday)
Issued at 424 AM CST THU JAN 29 2015
Gradual warm advection will take place through the day Friday
following a cold start and the arrival of the thicker high clouds
now appears will be delayed...therefore highs should recover back into
the low to middle 40s for highs.
Friday night...low and mid level warm air and moisture advection
will increase across the county warning area and persist into
Saturday. Although the atmosphere will initially be very dry
across the CWA...saturation will slowly occur west to east across
the CWA as warm air and moisture advection increases. Will maintain
a slight chance for precip over the north central in the
evening...with a increasing chances all areas overnight. Forecast
soundings Friday night continue to trend slightly warmer and
dewpoints increasing slightly as well. With still a fairly shallow
depth of warm air in place in the low levels...precip could fall as
rain or snow...although if surface temps fall to or below
freezing...precip would likely be snow. Will continue to carry a
rain/snow chance most areas Friday night...then mainly north of I 70
through Saturday. Areas south of I 70 should mainly be rain by
Saturday afternoon as freeze levels slowly increase in the
afternoon.
By late afternoon the GFS is the most aggressive with the arrival of
the colder air/front across the northern CWA with a possible
changeover to all snow which would slowly spread southward through
Saturday night. The EC and GEM are a little slower but still brings
the colder air southward through the night. Snow chances linger
through Sunday morning most areas...but should also decrease with
time as the main upper trough pushes through. At this
point...snowfall amounts look to be in the 1 to 2 inch range most
areas...but could be locally higher across the northern CWA if the
cold air moves in quicker.
After highs Saturday around 40...colder and blustery conditions will
be the rule Sunday with highs in the upper 20s to around 30 degrees.
Although wind speeds will decrease Sunday night...low temps in the 7
to 12 degree range will produce wind chills near zero.
Return flow to the south Monday should allow temps to recover back
into the upper 20s/lower 30s...then the lower 40s Tuesday before
another shortwave trough moving through the northern Plains pushes a
front through the area that night with slightly cooler highs in the
30s and low 40s on Wednesday. For now appears any snow chance will
remain north of the area.
&&
.AVIATION...(For the 18Z TAFs through 18Z Friday Afternoon)
Issued at 1109 AM CST THU JAN 29 2015
VFR ceilings will persist through the evening hours before exiting
the region. A surface ridge will cause light and variable winds
overnight with mostly clear skies. Limited moisture should prevent fog
development although conditions may support reduced visibilities during
the predawn hours. Winds will gradually veer through the period
and eventually end up out of the south.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Wolters
SHORT TERM...Wolters
LONG TERM...63
AVIATION...Sanders
AREA FORECAST DISCUSSION
NWS TOPEKA KS
632 AM CST Thu Jan 29 2015
.UPDATE...
Issued at 632 AM CST THU JAN 29 2015
The stronger wind gusts seems to be more isolated than earlier,
and overall obs show winds speeds below 30 MPH. With the RAP and
NAM showing the pressure gradient remaining at its current
magnitude or gradually weakening, will allow the wind advisory to
expire at 7 am. Nevertheless northwest winds of 15 to 25 MPH will
persist through much of the day.
&&
.SHORT TERM...(Today and Tonight)
Issued at 424 AM CST THU JAN 29 2015
A shortwave could be seen on the 08Z water vapor imagery passing
overhead into MO with a second shortwave moving southeast through SD
and WY. an upper level low pressure system was seen spinning well
off the Baja California coast and shortwaves within faster flow near
40N and 145W were moving towards the British Columbia coast. At the
surface, high pressure was building south through the central plains
causing gusty northwest winds from a tight pressure gradient. In
fact the gradient has been strong enough for sustained winds of
30 MPH and an occasional gust up to 45 MPH. Because of this, have
issued a wind advisory until 7 am. By then the pressure gradient
is expected to begin relaxing.
For today and tonight, the weather should remain relatively quiet
due to increasing dry air as the surface high pressure system
continues to move south. Because of this the shortwave over SD and
WY is not expected to do much in terms of sensible weather. However
subsidence behind this wave should help to erode away the low
stratus that has moved in, and think skies should clear out by the
late afternoon. Since there is not a lot of cold air behind this
front and models show the boundary layer mixing to almost 850MB,
think highs in the middle 40s looks reasonable. Lows tonight should
be a bit colder as the ridge axis moves in creating light winds with
clear skies. Expecting good radiational conditions, have adjusted
min temps down to around 20. Models show pretty high RH values
developing Friday morning suggestive of fog. Am not real confident
in fog formation since we have not had any meaningful precip lately
and soils remain very dry. Because of this think dewpoints are
likely to remain a couple degrees cooler than the air temp.
.LONG TERM...(Friday through Wednesday)
Issued at 424 AM CST THU JAN 29 2015
Gradual warm advection will take place through the day Friday
following a cold start and the arrival of the thicker high clouds
now appears will be delayed...therefore highs should recover back into
the low to middle 40s for highs.
Friday night...low and mid level warm air and moisture advection
will increase across the county warning area and persist into
Saturday. Although the atmosphere will initially be very dry
across the CWA...saturation will slowly occur west to east across
the CWA as warm air and moisture advection increases. Will maintain
a slight chance for precip over the north central in the
evening...with a increasing chances all areas overnight. Forecast
soundings Friday night continue to trend slightly warmer and
dewpoints increasing slightly as well. With still a fairly shallow
depth of warm air in place in the low levels...precip could fall as
rain or snow...although if surface temps fall to or below
freezing...precip would likely be snow. Will continue to carry a
rain/snow chance most areas Friday night...then mainly north of I 70
through Saturday. Areas south of I 70 should mainly be rain by
Saturday afternoon as freeze levels slowly increase in the
afternoon.
By late afternoon the GFS is the most aggressive with the arrival of
the colder air/front across the northern CWA with a possible
changeover to all snow which would slowly spread southward through
Saturday night. The EC and GEM are a little slower but still brings
the colder air southward through the night. Snow chances linger
through Sunday morning most areas...but should also decrease with
time as the main upper trough pushes through. At this
point...snowfall amounts look to be in the 1 to 2 inch range most
areas...but could be locally higher across the northern CWA if the
cold air moves in quicker.
After highs Saturday around 40...colder and blustery conditions will
be the rule Sunday with highs in the upper 20s to around 30 degrees.
Although wind speeds will decrease Sunday night...low temps in the 7
to 12 degree range will produce wind chills near zero.
Return flow to the south Monday should allow temps to recover back
into the upper 20s/lower 30s...then the lower 40s Tuesday before
another shortwave trough moving through the northern Plains pushes a
front through the area that night with slightly cooler highs in the
30s and low 40s on Wednesday. For now appears any snow chance will
remain north of the area.
&&
.AVIATION...(For the 12Z TAFs through 12Z Friday Morning)
Issued at 450 AM CST THU JAN 29 2015
Stratus continues to fill in from the north, and think it will
remain over the terminals for much of the day, until subsidence
from a second shortwave overspreads the area. For the most part
CIGS should remain above 2 KFT. Did lean on the optimistic side by
mixing CIGS above 3 KFT by noon based on the RAP forecast
soundings. But given how expansive the stratus is upstream, there
is some uncertainty in whether CIGS will lift and when they will
mix out. Gusty northwest and north winds will persist through the
day until the pressure gradient relaxes towards sunset.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY until 7 AM CST this morning FOR KSZ009>012-023-024-
026.
&&
$$
UPDATE...Wolters
SHORT TERM...Wolters
LONG TERM...63
AVIATION...Wolters
AREA FORECAST DISCUSSION
NWS TOPEKA KS
450 AM CST Thu Jan 29 2015
...AVIATION UPDATE...
.SHORT TERM...(Today and Tonight)
Issued at 424 AM CST THU JAN 29 2015
A shortwave could be seen on the 08Z water vapor imagery passing
overhead into MO with a second shortwave moving southeast through SD
and WY. an upper level low pressure system was seen spinning well
off the Baja California coast and shortwaves within faster flow near
40N and 145W were moving towards the British Columbia coast. At the
surface, high pressure was building south through the central plains
causing gusty northwest winds from a tight pressure gradient. In
fact the gradient has been strong enough for sustained winds of
30 MPH and an occasional gust up to 45 MPH. Because of this, have
issued a wind advisory until 7 am. By then the pressure gradient
is expected to begin relaxing.
For today and tonight, the weather should remain relatively quiet
due to increasing dry air as the surface high pressure system
continues to move south. Because of this the shortwave over SD and
WY is not expected to do much in terms of sensible weather. However
subsidence behind this wave should help to erode away the low
stratus that has moved in, and think skies should clear out by the
late afternoon. Since there is not a lot of cold air behind this
front and models show the boundary layer mixing to almost 850MB,
think highs in the middle 40s looks reasonable. Lows tonight should
be a bit colder as the ridge axis moves in creating light winds with
clear skies. Expecting good radiational conditions, have adjusted
min temps down to around 20. Models show pretty high RH values
developing Friday morning suggestive of fog. Am not real confident
in fog formation since we have not had any meaningful precip lately
and soils remain very dry. Because of this think dewpoints are
likely to remain a couple degrees cooler than the air temp.
.LONG TERM...(Friday through Wednesday)
Issued at 424 AM CST THU JAN 29 2015
Gradual warm advection will take place through the day Friday
following a cold start and the arrival of the thicker high clouds
now appears will be delayed...therefore highs should recover back into
the low to middle 40s for highs.
Friday night...low and mid level warm air and moisture advection
will increase across the county warning area and persist into
Saturday. Although the atmosphere will initially be very dry
across the CWA...saturation will slowly occur west to east across
the CWA as warm air and moisture advection increases. Will maintain
a slight chance for precip over the north central in the
evening...with a increasing chances all areas overnight. Forecast
soundings Friday night continue to trend slightly warmer and
dewpoints increasing slightly as well. With still a fairly shallow
depth of warm air in place in the low levels...precip could fall as
rain or snow...although if surface temps fall to or below
freezing...precip would likely be snow. Will continue to carry a
rain/snow chance most areas Friday night...then mainly north of I 70
through Saturday. Areas south of I 70 should mainly be rain by
Saturday afternoon as freeze levels slowly increase in the
afternoon.
By late afternoon the GFS is the most aggressive with the arrival of
the colder air/front across the northern CWA with a possible
changeover to all snow which would slowly spread southward through
Saturday night. The EC and GEM are a little slower but still brings
the colder air southward through the night. Snow chances linger
through Sunday morning most areas...but should also decrease with
time as the main upper trough pushes through. At this
point...snowfall amounts look to be in the 1 to 2 inch range most
areas...but could be locally higher across the northern CWA if the
cold air moves in quicker.
After highs Saturday around 40...colder and blustery conditions will
be the rule Sunday with highs in the upper 20s to around 30 degrees.
Although wind speeds will decrease Sunday night...low temps in the 7
to 12 degree range will produce wind chills near zero.
Return flow to the south Monday should allow temps to recover back
into the upper 20s/lower 30s...then the lower 40s Tuesday before
another shortwave trough moving through the northern Plains pushes a
front through the area that night with slightly cooler highs in the
30s and low 40s on Wednesday. For now appears any snow chance will
remain north of the area.
&&
.AVIATION...(For the 12Z TAFs through 12Z Friday Morning)
Issued at 450 AM CST THU JAN 29 2015
Stratus continues to fill in from the north, and think it will
remain over the terminals for much of the day, until subsidence
from a second shortwave overspreads the area. For the most part
CIGS should remain above 2 KFT. Did lean on the optimistic side by
mixing CIGS above 3 KFT by noon based on the RAP forecast
soundings. But given how expansive the stratus is upstream, there
is some uncertainty in whether CIGS will lift and when they will
mix out. Gusty northwest and north winds will persist through the
day until the pressure gradient relaxes towards sunset.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY until 7 AM CST this morning FOR KSZ009>012-023-024-
026.
&&
$$
SHORT TERM...Wolters
LONG TERM...63
AVIATION...Wolters
AREA FORECAST DISCUSSION
NWS JACKSON KY
211 PM EST THU JAN 29 2015
.UPDATE...
ISSUED AT 1225 PM EST THU JAN 29 2015
MADE MULTIPLE UPDATES BASED ON OBS AND NEW 12Z NAM. THIS INCLUDES
RAISING TEMPS FOR TODAY AND ADJUSTING TEMPS FOR TONIGHT INTO FRIDAY.
HAVE ALSO ADJUSTED SKY COVER TO ACCOUNT FOR TEMPORARY CLEARING TAKING
PLACE TODAY. TIMED POPS BASED ON NEW 12Z NAM TO INCLUDE THE BREAK IN
PRECIP THAT IS CURRENTLY OCCURRING. ADJUSTED SNOW POTENTIAL BASED ON
-10C MOISTURE AVAILABILITY ALOFT FOR TONIGHT.
UPDATE ISSUED AT 1113 AM EST THU JAN 29 2015
WITH PRECIP ON THE WAY OUT AND NO MORE OBSERVED TEMPS AT OR BELOW
FREEZING IN VALLEYS AND READINGS CONTINUING TO WARM...HAVE ALLOWED
THE WSW TO EXPIRE. HAVE ISSUED ANOTHER SPS UNTIL EARLY AFTERNOON FOR
ANY LINGERING PREVIOUSLY EXISTING ICE.
UPDATE ISSUED AT 1013 AM EST THU JAN 29 2015
WITH REPORTS OF MANY ACCIDENTS...ISSUED A FREEZING RAIN ADVISORY FOR
LOCATIONS WHERE VALLEYS TEMPS ARE BELOW FREEZING AND PRECIP IS STILL
OCCURRING. TEMPS ARE WARMING...SO THE ADVISORY ONLY RUNS FOR ABOUT
ANOTHER HOUR. WILL EVALUATE TEMPS IN A WHILE TO SEE IF IT CAN EXPIRE.
UPDATE ISSUED AT 844 AM EST THU JAN 29 2015
PRECIP SHIELD HAS MADE IT INTO OUR WESTERN FORECAST AREA.
TEMPERATURES HAVE RESPONDED WELL WHERE MEASURABLE PRECIPITATION IS
FALLING...HOWEVER SOME VALLEYS IN THE EAST STILL LINGER IN THE MID
20S. LOOKING AT RADAR TRENDS...THE MEASURABLE PRECIPITATION SEEMS TO
BE HAVING A HARDER TIME COMING EAST WITH SOME DOWNSLOPE FLOW IN
PLACE...AND READINGS HAVE BEEN EDGING UP EVEN IN THE COLDER SPOTS
PRIOR TO THE PRECIP ARRIVING. HAVE BEEFED UP POPS TO CATEGORICAL
ACROSS THE BOARD...AND WILL CONTINUE TO MENTION A CHANCE OF FREEZING
RAIN...AS SOME SPOTTY SLICK SPOTS STILL LOOK POSSIBLE. UPDATES HAVE
BEEN SENT.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 400 AM EST THU JAN 29 2015
LATEST SURFACE MAP FEATURES HIGH PRESSURE ALONG THE EASTERN
CONUS...WITH LOW PRESSURE MOVING INTO THE GREAT LAKES AND OHIO VALLEY
REGIONS. ALOFT...A SHORT WAVE TROUGH IS ROTATING TOWARDS THE OHIO
VALLEY...WITH ANOTHER TROUGH DROPPING SOUTHEAST INTO THE NORTHERN
PLAINS...AND YET ONE MORE MOVING IN ACROSS SOUTH CENTRAL CANADA.
MAINLY MID AND HIGH LEVEL CLOUDS HAVE BEEN STREAMING IN ACROSS
EASTERN KENTUCKY. THE SOUTHERLY WIND FLOW OUT AHEAD OF THE
APPROACHING SURFACE LOW HAS ALLOWED FOR A NICE RIDGE/VALLEY SPLIT
ACROSS THE AREA...WITH MORE SHELTERED VALLEYS HOLDING IN THE LOW AND
MID 20S...WHILE RIDGE TOPS ARE IN THE LOW TO MID 30S.
THE MODELS ARE IN GOOD AGREEMENT THROUGH THE SHORT TERM...TAKING THE
LOW PRESSURE SYSTEM EAST ACROSS THE OHIO VALLEY DURING THE DAY...AND
ALLOWING THE ASSOCIATED SURFACE COLD FRONT TO MOVE THROUGH THE AREA
THIS AFTERNOON INTO EARLY THIS EVENING. MEANWHILE...THE MORE NORTHERN
SHORT WAVES WILL CONTINUE TO DROP SOUTHEAST IN SUCCESSION...HELPING
TO ESTABLISH A DEEP TROUGH ACROSS THE EAST BY FRIDAY.
THE CURRENT RADAR SHOWS A BAND OF LIGHT RAIN FROM SOUTH CENTRAL
INDIANA DOWN THROUGH WESTERN KENTUCKY. THE LATEST HRRR SHOWS THIS
ACTIVITY MAKING IT TO OUR DOORSTEP BY DAWN OR SHORTLY THEREAFTER...
ALTHOUGH THERE IS GOOD AGREEMENT THAT THE MAJORITY OF THE MEASURABLE
PRECIPITATION WILL STAY JUST NORTH...WITH MORE SPOTTIER ACTIVITY TO
CONTEND WITH ACROSS OUR AREA THROUGH 14Z. AFTER 14Z...PRECIPITATION
LOOKS TO BLOSSOM AS THE BETTER FORCING ARRIVES. HAVE BEEN CONCERNED
WITH THE COLD VALLEY READINGS ACROSS OUR AREA...HOWEVER IT LOOKS AS
THOUGH THAT BY THE TIME THE BETTER PRECIPITATION DOES MOVE IN...THAT
MOST LOCATIONS WILL BE ABOVE FREEZING. AS SUCH...WILL ISSUE A SPECIAL
WEATHER STATEMENT COVERING THE SPOTTIER PRECIPITATION AT ONSET...AS
MAINLY INTERIOR LOCATIONS WILL STILL LIKELY BE BELOW FREEZING. WILL
CONTINUE TO MONITOR TRENDS VERY CLOSELY OVER THE NEXT FEW HOURS SINCE
ANY RAMP UP IN THE PRECIPITATION WILL MEAN AN ICY COMMUTE POTENTIALLY.
ONCE THE FIRST BATCH OF PRECIP MOVES THROUGH LATER THIS MORNING INTO
EARLY THIS AFTERNOON...THERE WILL LIKELY BE A LULL IN THE
ACTIVITY...BEFORE THE COLDER AIR ARRIVES ON NORTHWEST WINDS AND THE
TROUGH AXIS MOVES THROUGH TONIGHT. THIS WILL ALLOW FOR SOME LIGHT
SNOW ACROSS THE AREA. SNOW SHOWERS WILL LIKELY LINGER IN THE EAST
THROUGH FRIDAY MORNING...BEFORE TAPERING OFF. ANY LIGHT ACCUMULATIONS
WILL FAVOR THE HIGHER TERRAIN IN THE FAR SOUTHEAST.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 446 AM EST THU JAN 29 2015
HIGH PRESSURE WILL TAKE HOLD OF SENSIBLE WEATHER TO BEGIN THIS
PERIOD. WHILE LOW PRESSURE THAT IS AFFECTING THE REGION TODAY
DEVELOPS INTO ANOTHER STRONG COASTAL LOW ACROSS THE NORTHEAST US.
THIS HIGH PRESSURE COUPLED WITH DECREASING CLOUDS WILL ALLOW FOR
DECOUPLING AND LOWS DROPPING DOWN INTO THE MID TO UPPER TEENS
AREA WIDE. THIS HIGH PRESSURE WILL ALLOW MOSTLY SUNNY SKIES EARLY IN
THE DAY FOR YOUR SATURDAY WITH INCREASING CLOUDS IN THE AFTERNOON.
WINDS WILL ALSO BECOME MORE SOUTHWEST BRINGING HIGHS ON SATURDAY INTO
THE UPPER 30S TO LOWER 40S.
NOW THE BIGGER CONCERN CONTINUES TO BE LATE WEEKEND STORM AND
CONFIDENCE REMAINS LOW IN REGARDS TO THIS SYSTEM. THE SETUP IS WE
HAVE A DEVELOPING UPPER LEVEL CLOSED LOW ACROSS THE NORTHERN BAJA
PENINSULA AND ASSOCIATED DEVELOPING SURFACE LOW SATURDAY MORNING.
MEANWHILE A UPPER LEVEL WAVE RIDES OVER RIDGING ACROSS THE NORTHWEST
US. THEN THIS IS WHERE THE MODELS CONTINUE TO STRUGGLE IS IN THE
PHASING PROCESS THAT OCCURS SATURDAY NIGHT IN THE UPPER LEVELS.
EARLIER THE 18Z/28 GFS AND 12Z/28 ECMWF HAD A MORE OPEN WAVE WHICH
TRANSLATED TO A WEAKER SURFACE LOW. THIS WAS NEW BASED ON THE
PREVIOUS RUNS SEEN OVER THE PAST COUPLE OF DAYS. THE LATEST 00Z/29
RUN OF THE GFS DEVELOPS A STRONGER LOW WITH A BIT OF A DEEPER TROUGH
SETTING UP. THE 00Z/29 ECMWF DOES HAVE SIMILARITIES...HOWEVER THE
SURFACE LOW PRESSURE IS NOT AS DEEP. ONE THING THAT REMAINS WITH BOTH
MODELS 00Z RUNS IS BOTH HAVE A GOOD AMT OF QPF RESPECTIVELY. ANOTHER
QUESTION THAT REMAINS IS HOW MUCH COLD AIR STAYS IN PLACE WITH THIS
SYSTEM ON SUNDAY AND THIS WILL DEPEND HEAVILY ON THE EVENTUAL TRACK
OF THIS SURFACE LOW. THAT SAID HAVE LEANED TOWARD A BIT COLDER
THROUGH THE DAY ON SUNDAY. THINKING STILL MUCH OF SUNDAY WOULD LEAD
TO MIXING ACROSS MUCH OF THE CWA WITH MORE IN THE WAY OF SNOW ACROSS
THE BLUEGRASS WHERE TEMPS REMAIN COOLER...HOWEVER CONFIDENCE IN THIS
SYSTEM REMAINS LOW GIVEN THE DRASTIC RUN TO RUN CHANGES SEEN IN THE
DETERMINISTIC MODELS. ALSO KEEPING IN MIND THAT THE ENSEMBLE MEAN HAS
BEEN QUITE ERRATIC AND GIVEN THAT THE 12 PERTURBATIONS IN OUR SYSTEM
ARE ERRATIC EXPLAINS THE LACK OF CONTINUITY. ALL THIS SAID STILL
THINK THERE IS A REASONABLE SHOT OF MEASURABLE SNOW SUNDAY INTO
MONDAY. ANOTHER PIECE TO THE PUZZLE TO KEEP IN MIND IS THAT A MORE
NORTHERLY TRACK SHOWN IN EARLIER RUNS COULD ALLOW FOR MORE SOUTHERLY
FLOW AND WARMER AIR AND LEAD TO LESSENING SNOWFALL TOTALS. ALTHOUGH
BEHIND THIS SYSTEM EXPECT COLD AIR TO FILTER INTO ALL OF THE CWA
SUNDAY NIGHT INTO MONDAY. ALSO WOULD EXPECT GENERALLY FALLING
TEMPERATURES DURING THE DAY ON MONDAY.
AFTER THIS THE AFOREMENTIONED LOW PRESSURE IS THEN FORECAST TO TRACK NE
AND CONTINUE TO DEEPEN ALONG NE ATLANTIC COAST. HIGH PRESSURE WILL
BUILD EAST MONDAY NIGHT AND EXPECT ANOTHER COLD NIGHT WITH GENERALLY
LOW TO MID TEENS ACROSS THE REGION. THESE TEMPS MAY HAVE TO BE
ADJUSTED FURTHER DEPENDING UPON IF WE RECEIVE MEASURABLE SNOW. THIS
HIGH PRESSURE WILL ADVANCE EAST OF THE REGION MOVING INTO THE DAY ON
TUESDAY BRINGING RETURN FLOW AND WELCOMING REBOUND IN
TEMPERATURE...WITH HIGHS IN THE MID TO UPPER 30S. THAT SAID WEDNESDAY
REMAINS UNCERTAIN WITH YET ANOTHER SYSTEM DEVELOPING AND AT THIS POINT
STUCK CLOSE TO THE BLEND. DID INTRODUCE MAINLY SLIGHT POPS DURING
THAT PORTION OF THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 211 PM EST THU JAN 29 2015
VFR PREVAILED AT THE START OF THE PERIOD...BUT LOW VFR CEILINGS WERE
PROGRESSING SE ACROSS THE REGION AFTER A PERIOD OF CLEARING. THE
CEILINGS ON THE WAY IN WILL GET PROGRESSIVELY LOWER WITH TIME. BY 00Z
MVFR CAN BE EXPECTED AREA WIDE...WITH IFR BEGINNING TO SHOW UP.
SCATTERED LIGHT RAIN SHOWERS WILL ALSO DEVELOP DURING THE AFTERNOON.
MOST AREAS WILL DEGRADE TO IFR TONIGHT...AND REMAINING RAIN SHOWERS
WILL CHANGE TO SNOW SHOWERS. THE SNOW SHOWERS WILL TAPER OFF AND
CEILINGS WILL START TO BREAK UP DURING THE DAY ON FRIDAY. WINDS WILL
GUST IN THE NEIGHBORHOOD OF 15-20 KTS THROUGH THE PERIOD...INITIALLY
FROM THE SW AND THEN SHIFTING TO THE WEST TONIGHT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HAL
SHORT TERM...GEOGERIAN
LONG TERM...DJ
AVIATION...HAL
AREA FORECAST DISCUSSION
NWS JACKSON KY
207 PM EST THU JAN 29 2015
.UPDATE...
ISSUED AT 1225 PM EST THU JAN 29 2015
MADE MULTIPLE UPDATES BASED ON OBS AND NEW 12Z NAM. THIS INCLUDES
RAISING TEMPS FOR TODAY AND ADJUSTING TEMPS FOR TONIGHT INTO FRIDAY.
HAVE ALSO ADJUSTED SKY COVER TO ACCOUNT FOR TEMPORARY CLEARING TAKING
PLACE TODAY. TIMED POPS BASED ON NEW 12Z NAM TO INCLUDE THE BREAK IN
PRECIP THAT IS CURRENTLY OCCURRING. ADJUSTED SNOW POTENTIAL BASED ON
-10C MOISTURE AVAILABILITY ALOFT FOR TONIGHT.
UPDATE ISSUED AT 1113 AM EST THU JAN 29 2015
WITH PRECIP ON THE WAY OUT AND NO MORE OBSERVED TEMPS AT OR BELOW
FREEZING IN VALLEYS AND READINGS CONTINUING TO WARM...HAVE ALLOWED
THE WSW TO EXPIRE. HAVE ISSUED ANOTHER SPS UNTIL EARLY AFTERNOON FOR
ANY LINGERING PREVIOUSLY EXISTING ICE.
UPDATE ISSUED AT 1013 AM EST THU JAN 29 2015
WITH REPORTS OF MANY ACCIDENTS...ISSUED A FREEZING RAIN ADVISORY FOR
LOCATIONS WHERE VALLEYS TEMPS ARE BELOW FREEZING AND PRECIP IS STILL
OCCURRING. TEMPS ARE WARMING...SO THE ADVISORY ONLY RUNS FOR ABOUT
ANOTHER HOUR. WILL EVALUATE TEMPS IN A WHILE TO SEE IF IT CAN EXPIRE.
UPDATE ISSUED AT 844 AM EST THU JAN 29 2015
PRECIP SHIELD HAS MADE IT INTO OUR WESTERN FORECAST AREA.
TEMPERATURES HAVE RESPONDED WELL WHERE MEASURABLE PRECIPITATION IS
FALLING...HOWEVER SOME VALLEYS IN THE EAST STILL LINGER IN THE MID
20S. LOOKING AT RADAR TRENDS...THE MEASURABLE PRECIPITATION SEEMS TO
BE HAVING A HARDER TIME COMING EAST WITH SOME DOWNSLOPE FLOW IN
PLACE...AND READINGS HAVE BEEN EDGING UP EVEN IN THE COLDER SPOTS
PRIOR TO THE PRECIP ARRIVING. HAVE BEEFED UP POPS TO CATEGORICAL
ACROSS THE BOARD...AND WILL CONTINUE TO MENTION A CHANCE OF FREEZING
RAIN...AS SOME SPOTTY SLICK SPOTS STILL LOOK POSSIBLE. UPDATES HAVE
BEEN SENT.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 400 AM EST THU JAN 29 2015
LATEST SURFACE MAP FEATURES HIGH PRESSURE ALONG THE EASTERN
CONUS...WITH LOW PRESSURE MOVING INTO THE GREAT LAKES AND OHIO VALLEY
REGIONS. ALOFT...A SHORT WAVE TROUGH IS ROTATING TOWARDS THE OHIO
VALLEY...WITH ANOTHER TROUGH DROPPING SOUTHEAST INTO THE NORTHERN
PLAINS...AND YET ONE MORE MOVING IN ACROSS SOUTH CENTRAL CANADA.
MAINLY MID AND HIGH LEVEL CLOUDS HAVE BEEN STREAMING IN ACROSS
EASTERN KENTUCKY. THE SOUTHERLY WIND FLOW OUT AHEAD OF THE
APPROACHING SURFACE LOW HAS ALLOWED FOR A NICE RIDGE/VALLEY SPLIT
ACROSS THE AREA...WITH MORE SHELTERED VALLEYS HOLDING IN THE LOW AND
MID 20S...WHILE RIDGE TOPS ARE IN THE LOW TO MID 30S.
THE MODELS ARE IN GOOD AGREEMENT THROUGH THE SHORT TERM...TAKING THE
LOW PRESSURE SYSTEM EAST ACROSS THE OHIO VALLEY DURING THE DAY...AND
ALLOWING THE ASSOCIATED SURFACE COLD FRONT TO MOVE THROUGH THE AREA
THIS AFTERNOON INTO EARLY THIS EVENING. MEANWHILE...THE MORE NORTHERN
SHORT WAVES WILL CONTINUE TO DROP SOUTHEAST IN SUCCESSION...HELPING
TO ESTABLISH A DEEP TROUGH ACROSS THE EAST BY FRIDAY.
THE CURRENT RADAR SHOWS A BAND OF LIGHT RAIN FROM SOUTH CENTRAL
INDIANA DOWN THROUGH WESTERN KENTUCKY. THE LATEST HRRR SHOWS THIS
ACTIVITY MAKING IT TO OUR DOORSTEP BY DAWN OR SHORTLY THEREAFTER...
ALTHOUGH THERE IS GOOD AGREEMENT THAT THE MAJORITY OF THE MEASURABLE
PRECIPITATION WILL STAY JUST NORTH...WITH MORE SPOTTIER ACTIVITY TO
CONTEND WITH ACROSS OUR AREA THROUGH 14Z. AFTER 14Z...PRECIPITATION
LOOKS TO BLOSSOM AS THE BETTER FORCING ARRIVES. HAVE BEEN CONCERNED
WITH THE COLD VALLEY READINGS ACROSS OUR AREA...HOWEVER IT LOOKS AS
THOUGH THAT BY THE TIME THE BETTER PRECIPITATION DOES MOVE IN...THAT
MOST LOCATIONS WILL BE ABOVE FREEZING. AS SUCH...WILL ISSUE A SPECIAL
WEATHER STATEMENT COVERING THE SPOTTIER PRECIPITATION AT ONSET...AS
MAINLY INTERIOR LOCATIONS WILL STILL LIKELY BE BELOW FREEZING. WILL
CONTINUE TO MONITOR TRENDS VERY CLOSELY OVER THE NEXT FEW HOURS SINCE
ANY RAMP UP IN THE PRECIPITATION WILL MEAN AN ICY COMMUTE POTENTIALLY.
ONCE THE FIRST BATCH OF PRECIP MOVES THROUGH LATER THIS MORNING INTO
EARLY THIS AFTERNOON...THERE WILL LIKELY BE A LULL IN THE
ACTIVITY...BEFORE THE COLDER AIR ARRIVES ON NORTHWEST WINDS AND THE
TROUGH AXIS MOVES THROUGH TONIGHT. THIS WILL ALLOW FOR SOME LIGHT
SNOW ACROSS THE AREA. SNOW SHOWERS WILL LIKELY LINGER IN THE EAST
THROUGH FRIDAY MORNING...BEFORE TAPERING OFF. ANY LIGHT ACCUMULATIONS
WILL FAVOR THE HIGHER TERRAIN IN THE FAR SOUTHEAST.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 446 AM EST THU JAN 29 2015
HIGH PRESSURE WILL TAKE HOLD OF SENSIBLE WEATHER TO BEGIN THIS
PERIOD. WHILE LOW PRESSURE THAT IS AFFECTING THE REGION TODAY
DEVELOPS INTO ANOTHER STRONG COASTAL LOW ACROSS THE NORTHEAST US.
THIS HIGH PRESSURE COUPLED WITH DECREASING CLOUDS WILL ALLOW FOR
DECOUPLING AND LOWS DROPPING DOWN INTO THE MID TO UPPER TEENS
AREA WIDE. THIS HIGH PRESSURE WILL ALLOW MOSTLY SUNNY SKIES EARLY IN
THE DAY FOR YOUR SATURDAY WITH INCREASING CLOUDS IN THE AFTERNOON.
WINDS WILL ALSO BECOME MORE SOUTHWEST BRINGING HIGHS ON SATURDAY INTO
THE UPPER 30S TO LOWER 40S.
NOW THE BIGGER CONCERN CONTINUES TO BE LATE WEEKEND STORM AND
CONFIDENCE REMAINS LOW IN REGARDS TO THIS SYSTEM. THE SETUP IS WE
HAVE A DEVELOPING UPPER LEVEL CLOSED LOW ACROSS THE NORTHERN BAJA
PENINSULA AND ASSOCIATED DEVELOPING SURFACE LOW SATURDAY MORNING.
MEANWHILE A UPPER LEVEL WAVE RIDES OVER RIDGING ACROSS THE NORTHWEST
US. THEN THIS IS WHERE THE MODELS CONTINUE TO STRUGGLE IS IN THE
PHASING PROCESS THAT OCCURS SATURDAY NIGHT IN THE UPPER LEVELS.
EARLIER THE 18Z/28 GFS AND 12Z/28 ECMWF HAD A MORE OPEN WAVE WHICH
TRANSLATED TO A WEAKER SURFACE LOW. THIS WAS NEW BASED ON THE
PREVIOUS RUNS SEEN OVER THE PAST COUPLE OF DAYS. THE LATEST 00Z/29
RUN OF THE GFS DEVELOPS A STRONGER LOW WITH A BIT OF A DEEPER TROUGH
SETTING UP. THE 00Z/29 ECMWF DOES HAVE SIMILARITIES...HOWEVER THE
SURFACE LOW PRESSURE IS NOT AS DEEP. ONE THING THAT REMAINS WITH BOTH
MODELS 00Z RUNS IS BOTH HAVE A GOOD AMT OF QPF RESPECTIVELY. ANOTHER
QUESTION THAT REMAINS IS HOW MUCH COLD AIR STAYS IN PLACE WITH THIS
SYSTEM ON SUNDAY AND THIS WILL DEPEND HEAVILY ON THE EVENTUAL TRACK
OF THIS SURFACE LOW. THAT SAID HAVE LEANED TOWARD A BIT COLDER
THROUGH THE DAY ON SUNDAY. THINKING STILL MUCH OF SUNDAY WOULD LEAD
TO MIXING ACROSS MUCH OF THE CWA WITH MORE IN THE WAY OF SNOW ACROSS
THE BLUEGRASS WHERE TEMPS REMAIN COOLER...HOWEVER CONFIDENCE IN THIS
SYSTEM REMAINS LOW GIVEN THE DRASTIC RUN TO RUN CHANGES SEEN IN THE
DETERMINISTIC MODELS. ALSO KEEPING IN MIND THAT THE ENSEMBLE MEAN HAS
BEEN QUITE ERRATIC AND GIVEN THAT THE 12 PERTURBATIONS IN OUR SYSTEM
ARE ERRATIC EXPLAINS THE LACK OF CONTINUITY. ALL THIS SAID STILL
THINK THERE IS A REASONABLE SHOT OF MEASURABLE SNOW SUNDAY INTO
MONDAY. ANOTHER PIECE TO THE PUZZLE TO KEEP IN MIND IS THAT A MORE
NORTHERLY TRACK SHOWN IN EARLIER RUNS COULD ALLOW FOR MORE SOUTHERLY
FLOW AND WARMER AIR AND LEAD TO LESSENING SNOWFALL TOTALS. ALTHOUGH
BEHIND THIS SYSTEM EXPECT COLD AIR TO FILTER INTO ALL OF THE CWA
SUNDAY NIGHT INTO MONDAY. ALSO WOULD EXPECT GENERALLY FALLING
TEMPERATURES DURING THE DAY ON MONDAY.
AFTER THIS THE AFOREMENTIONED LOW PRESSURE IS THEN FORECAST TO TRACK NE
AND CONTINUE TO DEEPEN ALONG NE ATLANTIC COAST. HIGH PRESSURE WILL
BUILD EAST MONDAY NIGHT AND EXPECT ANOTHER COLD NIGHT WITH GENERALLY
LOW TO MID TEENS ACROSS THE REGION. THESE TEMPS MAY HAVE TO BE
ADJUSTED FURTHER DEPENDING UPON IF WE RECEIVE MEASURABLE SNOW. THIS
HIGH PRESSURE WILL ADVANCE EAST OF THE REGION MOVING INTO THE DAY ON
TUESDAY BRINGING RETURN FLOW AND WELCOMING REBOUND IN
TEMPERATURE...WITH HIGHS IN THE MID TO UPPER 30S. THAT SAID WEDNESDAY
REMAINS UNCERTAIN WITH YET ANOTHER SYSTEM DEVELOPING AND AT THIS POINT
STUCK CLOSE TO THE BLEND. DID INTRODUCE MAINLY SLIGHT POPS DURING
THAT PORTION OF THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 207 PM EST THU JAN 29 2015
VFR PREVAILED AT THE START OF THE PERIOD...BUT LOW VFR CEILINGS WERE
PROGRESSING SE ACROSS THE REGION AFTER A PERIOD OF CLEARING. THE
CEILINGS ON THE WAY IN WILL GET PROGRESSIVELY LOWER WITH TIME. BY 00Z
MVFR CAN BE EXPECTED AREA WIDE...WITH IFR BEGINNING TO SHOW UP.
SCATTERED LIGHT RAIN SHOWERS WILL ALSO DEVELOP DURING THE AFTERNOON.
MOST AREAS WILL DEGRADE TO IFR TONIGHT...AND REMAINING RAIN SHOWERS
WILL CHANGE TO SNOW SHOWERS. THE SNOW SHOWERS WILL TAPER OFF AND
CEILINGS WILL START TO BREAK UP DURING THE DAY ON FRIDAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HAL
SHORT TERM...GEOGERIAN
LONG TERM...DJ
AVIATION...HAL
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1137 AM CST Thu Jan 29 2015
.UPDATE...
Issued at 1137 AM CST THU JAN 29 2015
The AVIATION section has been updated for the 18Z TAF issuance.
UPDATE Issued at 905 AM CST THU JAN 29 2015
The forecast has been updated to catch up to the cloud and
temperature trends. Much of west Kentucky will have highs greater
than forecast late this morning. Also, the latest HRRR has no
precipitation over the area through the day, so removed all
measurable PoPs. Would not rule out some patchy drizzle across the
Evansville Tri State region this afternoon, but will add that in
once it becomes more obvious.
&&
.SHORT TERM (Today through Saturday)...
Issued at 255 AM CST Thu Jan 29 2015
A well-defined cold front will move quickly southeast across our
region this morning. A small line of showers developed well ahead
of the front from kowb to khop early this morning. Cannot rule out
another small line until the front passes to our east. For most of
the forecast area, this will be a dry frontal passage.
Behind the front, winds will shift into the northwest and become
rather gusty today. Some gusts around 25 knots are likely. NAM and
GFS 925 mb rh progs indicate widespread low cloudiness will arrive
behind the front and persist through the afternoon. Low level cold
advection and widespread cloudiness should result in a steady or
slowly falling temperature trend this afternoon. Highs will be in
the morning. A period of sunshine prior to the arrival of low
clouds could push temps up from their 08z readings in the mid 40s
to lower 50s.
The main forecast issue for tonight is when and if the low clouds
will clear out. 925 mb rh forecasts from the 00z nam and gfs are
quite moist all night, especially east of the Mississippi River.
The forecast will show partial clearing from west to east tonight,
but at a slower rate than previous forecasts. Lows will be in the
mid to upper 20s.
Friday still looks mostly sunny, although there may still be some
morning low clouds in southwest Indiana and northwest Kentucky.
Winds will decrease as surface high pressure reaches the mid and
upper Mississippi Valley. Highs should be quite cold considering
the amount of sun, ranging from the mid 30s to lower 40s.
Friday night and Saturday...mid and high clouds will gradually
increase ahead of the next system. The low levels will be
extremely dry, which should make it very difficult for precip to
reach the ground. Will keep in a slight chance of showers in the
Ozark foothills of southeast Missouri. Despite the clouds, highs
should be mainly in the lower and mid 40s due to southerly winds.
.LONG TERM (Saturday night through Wednesday)...
Issued at 300 AM CST Thu Jan 29 2015
Main forecast challenge in this time frame comes with the storm
system that looks to be impacting the region over the weekend,
especially Sunday. Forecast confidence remains fairly low at this
time regarding precip types.
As we begin the period, split mid/upper flow pattern should be in
place...with nrn branch trof digging se into the Plains and a nearly
stationary srn branch low in place over the Baja of CA. It now looks
as though the srn branch low will feed pacific moisture into the nrn
branch...leading to fairly widespread precip shield over the mid MS
River and Ohio Valleys Saturday night and esp Sunday as sfc low
pressure develops over the Gulf Coast states. As mentioned, the main
uncertainly at this time lies with precip type. The latest 00z runs
of the operational GFS and ECMWF are now in decent agreement that
the sfc low and inverted trof will remain farther south over
MS/AL...as a 1040 mb sfc high presses south into the nrn Plains.
This would result in a colder thermal profile than we were thinking
yesterday. Snow would be the main precip type over all except our
far southern counties, with some potential for a few inches, esp
along and north/west of the Ohio River. On the other hand for
example, 00Z NAM/GEM both bring the sfc low farther north, and are
thus much warmer in their thermal profiles. For this package, will
keep much of the nrn half of the forecast area mostly snow, and go
with rain/snow for now over much of wrn KY and se MO. Again,
uncertainty is still quite high and things are likely to change one
way or another as we get closer to the event.
Very cold air will follow in the wake of the system as Canadian high
pressure moves se into the region. Most locations will fall into the
teens later Sunday night and Monday night. Highs Monday will likely
remain below freezing. Of course, things could be even colder if any
areas manage to get a fresh layer of snow on the ground. The next
clipper system Tue/Tue night is expected to stay much farther north
and cross over the Great lakes region. May be some light precip as
it drags another cold front across the region, but most impacts with
this low are expected to remain north of the forecast area.
&&
.AVIATION...
Issued at 1137 AM CST THU JAN 29 2015
A large mass of MVFR ceilings is overspreading the region behind a
cold front late this morning. Given the expanse of the MVFR clouds
at this time, would not expect them to depart any time soon.
Definitely went on the pessimistic side of guidance with scattering
or lifting not until Friday morning. Northwest winds will continue
to gust well above 20kts this afternoon, but they should subside
some by sunset. Winds will remain around 10kts through the
remainder of the period.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...DRS
SHORT TERM...MY
LONG TERM....GM
AVIATION...DRS
AREA FORECAST DISCUSSION
NWS JACKSON KY
1225 PM EST THU JAN 29 2015
.UPDATE...
ISSUED AT 1225 PM EST THU JAN 29 2015
MADE MULTIPLE UPDATES BASED ON OBS AND NEW 12Z NAM. THIS INCLUDES
RAISING TEMPS FOR TODAY AND ADJUSTING TEMPS FOR TONIGHT INTO FRIDAY.
HAVE ALSO ADJUSTED SKY COVER TO ACCOUNT FOR TEMPORARY CLEARING TAKING
PLACE TODAY. TIMED POPS BASED ON NEW 12Z NAM TO INCLUDE THE BREAK IN
PRECIP THAT IS CURRENTLY OCCURRING. ADJUSTED SNOW POTENTIAL BASED ON
-10C MOISTURE AVAILABILITY ALOFT FOR TONIGHT.
UPDATE ISSUED AT 1113 AM EST THU JAN 29 2015
WITH PRECIP ON THE WAY OUT AND NO MORE OBSERVED TEMPS AT OR BELOW
FREEZING IN VALLEYS AND READINGS CONTINUING TO WARM...HAVE ALLOWED
THE WSW TO EXPIRE. HAVE ISSUED ANOTHER SPS UNTIL EARLY AFTERNOON FOR
ANY LINGERING PREVIOUSLY EXISTING ICE.
UPDATE ISSUED AT 1013 AM EST THU JAN 29 2015
WITH REPORTS OF MANY ACCIDENTS...ISSUED A FREEZING RAIN ADVISORY FOR
LOCATIONS WHERE VALLEYS TEMPS ARE BELOW FREEZING AND PRECIP IS STILL
OCCURRING. TEMPS ARE WARMING...SO THE ADVISORY ONLY RUNS FOR ABOUT
ANOTHER HOUR. WILL EVALUATE TEMPS IN A WHILE TO SEE IF IT CAN EXPIRE.
UPDATE ISSUED AT 844 AM EST THU JAN 29 2015
PRECIP SHIELD HAS MADE IT INTO OUR WESTERN FORECAST AREA.
TEMPERATURES HAVE RESPONDED WELL WHERE MEASURABLE PRECIPITATION IS
FALLING...HOWEVER SOME VALLEYS IN THE EAST STILL LINGER IN THE MID
20S. LOOKING AT RADAR TRENDS...THE MEASURABLE PRECIPITATION SEEMS TO
BE HAVING A HARDER TIME COMING EAST WITH SOME DOWNSLOPE FLOW IN
PLACE...AND READINGS HAVE BEEN EDGING UP EVEN IN THE COLDER SPOTS
PRIOR TO THE PRECIP ARRIVING. HAVE BEEFED UP POPS TO CATEGORICAL
ACROSS THE BOARD...AND WILL CONTINUE TO MENTION A CHANCE OF FREEZING
RAIN...AS SOME SPOTTY SLICK SPOTS STILL LOOK POSSIBLE. UPDATES HAVE
BEEN SENT.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 400 AM EST THU JAN 29 2015
LATEST SURFACE MAP FEATURES HIGH PRESSURE ALONG THE EASTERN
CONUS...WITH LOW PRESSURE MOVING INTO THE GREAT LAKES AND OHIO VALLEY
REGIONS. ALOFT...A SHORT WAVE TROUGH IS ROTATING TOWARDS THE OHIO
VALLEY...WITH ANOTHER TROUGH DROPPING SOUTHEAST INTO THE NORTHERN
PLAINS...AND YET ONE MORE MOVING IN ACROSS SOUTH CENTRAL CANADA.
MAINLY MID AND HIGH LEVEL CLOUDS HAVE BEEN STREAMING IN ACROSS
EASTERN KENTUCKY. THE SOUTHERLY WIND FLOW OUT AHEAD OF THE
APPROACHING SURFACE LOW HAS ALLOWED FOR A NICE RIDGE/VALLEY SPLIT
ACROSS THE AREA...WITH MORE SHELTERED VALLEYS HOLDING IN THE LOW AND
MID 20S...WHILE RIDGETOPS ARE IN THE LOW TO MID 30S.
THE MODELS ARE IN GOOD AGREEMENT THROUGH THE SHORT TERM...TAKING THE
LOW PRESSURE SYSTEM EAST ACROSS THE OHIO VALLEY DURING THE DAY...AND
ALLOWING THE ASSOCIATED SURFACE COLD FRONT TO MOVE THROUGH THE AREA
THIS AFTERNOON INTO EARLY THIS EVENING. MEANWHILE...THE MORE NORTHERN
SHORT WAVES WILL CONTINUE TO DROP SOUTHEAST IN SUCCESSION...HELPING
TO ESTABLISH A DEEP TROUGH ACROSS THE EAST BY FRIDAY.
THE CURRENT RADAR SHOWS A BAND OF LIGHT RAIN FROM SOUTH CENTRAL
INDIANA DOWN THROUGH WESTERN KENTUCKY. THE LATEST HRRR SHOWS THIS
ACTIVITY MAKING IT TO OUR DOORSTEP BY DAWN OR SHORTLY THEREAFTER...
ALTHOUGH THERE IS GOOD AGREEMENT THAT THE MAJORITY OF THE MEASURABLE
PRECIPITATION WILL STAY JUST NORTH...WITH MORE SPOTTIER ACTIVITY TO
CONTEND WITH ACROSS OUR AREA THROUGH 14Z. AFTER 14Z...PRECIPITATION
LOOKS TO BLOSSOM AS THE BETTER FORCING ARRIVES. HAVE BEEN CONCERNED
WITH THE COLD VALLEY READINGS ACROSS OUR AREA...HOWEVER IT LOOKS AS
THOUGH THAT BY THE TIME THE BETTER PRECIPITATION DOES MOVE IN...THAT
MOST LOCATIONS WILL BE ABOVE FREEZING. AS SUCH...WILL ISSUE A SPECIAL
WEATHER STATEMENT COVERING THE SPOTTIER PRECIPITATION AT ONSET...AS
MAINLY INTERIOR LOCATIONS WILL STILL LIKELY BE BELOW FREEZING. WILL
CONTINUE TO MONITOR TRENDS VERY CLOSELY OVER THE NEXT FEW HOURS SINCE
ANY RAMP UP IN THE PRECIPITATION WILL MEAN AN ICY COMMUTE POTENTIALLY.
ONCE THE FIRST BATCH OF PRECIP MOVES THROUGH LATER THIS MORNING INTO
EARLY THIS AFTERNOON...THERE WILL LIKELY BE A LULL IN THE
ACTIVITY...BEFORE THE COLDER AIR ARRIVES ON NORTHWEST WINDS AND THE
TROUGH AXIS MOVES THROUGH TONIGHT. THIS WILL ALLOW FOR SOME LIGHT
SNOW ACROSS THE AREA. SNOW SHOWERS WILL LIKELY LINGER IN THE EAST
THROUGH FRIDAY MORNING...BEFORE TAPERING OFF. ANY LIGHT ACCUMULATIONS
WILL FAVOR THE HIGHER TERRAIN IN THE FAR SOUTHEAST.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 446 AM EST THU JAN 29 2015
HIGH PRESSURE WILL TAKE HOLD OF SENSIBLE WEATHER TO BEGIN THIS
PERIOD. WHILE LOW PRESSURE THAT IS AFFECTING THE REGION TODAY
DEVELOPS INTO ANOTHER STRONG COASTAL LOW ACROSS THE NORTHEAST US.
THIS HIGH PRESSURE COUPLED WITH DECREASING CLOUDS WILL ALLOW FOR
DECOUPLING AND LOWS DROPPING DOWN INTO THE MID TO UPPER TEENS
AREA WIDE. THIS HIGH PRESSURE WILL ALLOW MOSTLY SUNNY SKIES EARLY IN
THE DAY FOR YOUR SATURDAY WITH INCREASING CLOUDS IN THE AFTERNOON.
WINDS WILL ALSO BECOME MORE SOUTHWEST BRINGING HIGHS ON SATURDAY INTO
THE UPPER 30S TO LOWER 40S.
NOW THE BIGGER CONCERN CONTINUES TO BE LATE WEEKEND STORM AND
CONFIDENCE REMAINS LOW IN REGARDS TO THIS SYSTEM. THE SETUP IS WE
HAVE A DEVELOPING UPPER LEVEL CLOSED LOW ACROSS THE NORTHERN BAJA
PENINSULA AND ASSOCIATED DEVELOPING SURFACE LOW SATURDAY MORNING.
MEANWHILE A UPPER LEVEL WAVE RIDES OVER RIDGING ACROSS THE NORTHWEST
US. THEN THIS IS WHERE THE MODELS CONTINUE TO STRUGGLE IS IN THE
PHASING PROCESS THAT OCCURS SATURDAY NIGHT IN THE UPPER LEVELS.
EARLIER THE 18Z/28 GFS AND 12Z/28 ECMWF HAD A MORE OPEN WAVE WHICH
TRANSLATED TO A WEAKER SURFACE LOW. THIS WAS NEW BASED ON THE
PREVIOUS RUNS SEEN OVER THE PAST COUPLE OF DAYS. THE LATEST 00Z/29
RUN OF THE GFS DEVELOPS A STRONGER LOW WITH A BIT OF A DEEPER TROUGH
SETTING UP. THE 00Z/29 ECMWF DOES HAVE SIMILARITIES...HOWEVER THE
SURFACE LOW PRESSURE IS NOT AS DEEP. ONE THING THAT REMAINS WITH BOTH
MODELS 00Z RUNS IS BOTH HAVE A GOOD AMT OF QPF RESPECTIVELY. ANOTHER
QUESTION THAT REMAINS IS HOW MUCH COLD AIR STAYS IN PLACE WITH THIS
SYSTEM ON SUNDAY AND THIS WILL DEPEND HEAVILY ON THE EVENTUAL TRACK
OF THIS SURFACE LOW. THAT SAID HAVE LEANED TOWARD A BIT COLDER
THROUGH THE DAY ON SUNDAY. THINKING STILL MUCH OF SUNDAY WOULD LEAD
TO MIXING ACROSS MUCH OF THE CWA WITH MORE IN THE WAY OF SNOW ACROSS
THE BLUEGRASS WHERE TEMPS REMAIN COOLER...HOWEVER CONFIDENCE IN THIS
SYSTEM REMAINS LOW GIVEN THE DRASTIC RUN TO RUN CHANGES SEEN IN THE
DETERMINISTIC MODELS. ALSO KEEPING IN MIND THAT THE ENSEMBLE MEAN HAS
BEEN QUITE ERRATIC AND GIVEN THAT THE 12 PERTURBATIONS IN OUR SYSTEM
ARE ERRATIC EXPLAINS THE LACK OF CONTINUITY. ALL THIS SAID STILL
THINK THERE IS A REASONABLE SHOT OF MEASURABLE SNOW SUNDAY INTO
MONDAY. ANOTHER PIECE TO THE PUZZLE TO KEEP IN MIND IS THAT A MORE
NORTHERLY TRACK SHOWN IN EARLIER RUNS COULD ALLOW FOR MORE SOUTHERLY
FLOW AND WARMER AIR AND LEAD TO LESSENING SNOWFALL TOTALS. ALTHOUGH
BEHIND THIS SYSTEM EXPECT COLD AIR TO FILTER INTO ALL OF THE CWA
SUNDAY NIGHT INTO MONDAY. ALSO WOULD EXPECT GENERALLY FALLING
TEMPERATURES DURING THE DAY ON MONDAY.
AFTER THIS THE AFOREMENTIONED LOW PRESSURE IS THEN FORECAST TO TRACK NE
AND CONTINUE TO DEEPEN ALONG NE ATLANTIC COAST. HIGH PRESSURE WILL
BUILD EAST MONDAY NIGHT AND EXPECT ANOTHER COLD NIGHT WITH GENERALLY
LOW TO MID TEENS ACROSS THE REGION. THESE TEMPS MAY HAVE TO BE
ADJUSTED FURTHER DEPENDING UPON IF WE RECEIVE MEASURABLE SNOW. THIS
HIGH PRESSURE WILL ADVANCE EAST OF THE REGION MOVING INTO THE DAY ON
TUESDAY BRINGING RETURN FLOW AND WELCOMING REBOUND IN
TEMPERATURE...WITH HIGHS IN THE MID TO UPPER 30S. THAT SAID WEDNESDAY
REMAINS UNCERTAIN WITH YET ANOTHER SYSTEM DEVELOPING AND AT THIS POINT
STUCK CLOSE TO THE BLEND. DID INTRODUCE MAINLY SLIGHT POPS DURING
THAT PORTION OF THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 844 AM EST THU JAN 29 2015
A PASSING COLD FRONT WILL BRING LOWERING CEILINGS...PRECIPITATION...
AND GUSTY SOUTH TO SOUTHWEST WINDS TO THE AREA THROUGH THIS EVENING.
VFR CONDITIONS WILL LIKELY HOLD ON THROUGH THE EARLY
AFTERNOON...BEFORE CEILINGS LIKELY COME DOWN QUICKLY TO MVFR/IFR ONCE
THE FRONT MOVES THROUGH THE AREA LATER THIS AFTERNOON INTO EARLY THIS
EVENING. PRECIPITATION WILL TAPER OFF THIS MORNING...AND THEN LOOKS
TO PICK UP AGAIN TONIGHT AS AN UPPER TROUGH AXIS MOVES ACROSS THE OHIO
AND TENNESSEE VALLEYS. COLDER AIR WILL MOVE IN ON NORTHWEST
WINDS...WITH RAIN CHANGING OVER TO SNOW. SOUTH TO SOUTHWEST WINDS OF
10 TO 15 KTS...WITH GUSTS IN THE 15 TO 20 KT RANGE WILL SHIFT TO THE
WEST AND EVENTUALLY NORTHWEST. THE WINDS WILL DIMINISH AND BECOME
LESS GUSTY AFTER DUSK.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HAL
SHORT TERM...GEOGERIAN
LONG TERM...DJ
AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION
NWS JACKSON KY
1113 AM EST THU JAN 29 2015
.UPDATE...
ISSUED AT 1113 AM EST THU JAN 29 2015
WITH PRECIP ON THE WAY OUT AND NO MORE OBSERVED TEMPS AT OR BELOW
FREEZING IN VALLEYS AND READINGS CONTINUING TO WARM...HAVE ALLOWED
THE WSW TO EXPIRE. HAVE ISSUED ANOTHER SPS UNTIL EARLY AFTERNOON FOR
ANY LINGERING PREVIOUSLY EXISTING ICE.
UPDATE ISSUED AT 1013 AM EST THU JAN 29 2015
WITH REPORTS OF MANY ACCIDENTS...ISSUED A FREEZING RAIN ADVISORY FOR
LOCATIONS WHERE VALLEYS TEMPS ARE BELOW FREEZING AND PRECIP IS STILL
OCCURRING. TEMPS ARE WARMING...SO THE ADVISORY ONLY RUNS FOR ABOUT
ANOTHER HOUR. WILL EVALUATE TEMPS IN A WHILE TO SEE IF IT CAN EXPIRE.
UPDATE ISSUED AT 844 AM EST THU JAN 29 2015
PRECIP SHIELD HAS MADE INTO OUR WESTERN FORECAST AREA. TEMPERATURES
HAVE RESPONDED WELL WHERE MEASURABLE PRECIPITATION IS
FALLING...HOWEVER SOME VALLEYS IN THE EAST STILL LINGER IN THE MID
20S. LOOKING AT RADAR TRENDS...THE MEASURABLE PRECIPITATION SEEMS TO
BE HAVING A HARDER TIME COMING EAST WITH SOME DOWNSLOPE FLOW IN
PLACE...AND READINGS HAVE BEEN EDGING UP EVEN IN THE COLDER SPOTS
PRIOR TO THE PRECIP ARRIVING. HAVE BEEFED UP POPS TO CATEGORICAL
ACROSS THE BOARD...AND WILL CONTINUE TO MENTION A CHANCE OF FREEZING
RAIN...AS SOME SPOTTY SLICK SPOTS STILL LOOK POSSIBLE. UPDATES HAVE
BEEN SENT.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 400 AM EST THU JAN 29 2015
LATEST SURFACE MAP FEATURES HIGH PRESSURE ALONG THE EASTERN
CONUS...WITH LOW PRESSURE MOVING INTO THE GREAT LAKES AND OHIO VALLEY
REGIONS. ALOFT...A SHORT WAVE TROUGH IS ROTATING TOWARDS THE OHIO
VALLEY...WITH ANOTHER TROUGH DROPPING SOUTHEAST INTO THE NORTHERN
PLAINS...AND YET ONE MORE MOVING IN ACROSS SOUTH CENTRAL CANADA.
MAINLY MID AND HIGH LEVEL CLOUDS HAVE BEEN STREAMING IN ACROSS
EASTERN KENTUCKY. THE SOUTHERLY WIND FLOW OUT AHEAD OF THE
APPROACHING SURFACE LOW HAS ALLOWED FOR A NICE RIDGE/VALLEY SPLIT
ACROSS THE AREA...WITH MORE SHELTERED VALLEYS HOLDING IN THE LOW AND
MID 20S...WHILE RIDGETOPS ARE IN THE LOW TO MID 30S.
THE MODELS ARE IN GOOD AGREEMENT THROUGH THE SHORT TERM...TAKING THE
LOW PRESSURE SYSTEM EAST ACROSS THE OHIO VALLEY DURING THE DAY...AND
ALLOWING THE ASSOCIATED SURFACE COLD FRONT TO MOVE THROUGH THE AREA
THIS AFTERNOON INTO EARLY THIS EVENING. MEANWHILE...THE MORE NORTHERN
SHORT WAVES WILL CONTINUE TO DROP SOUTHEAST IN SUCCESSION...HELPING
TO ESTABLISH A DEEP TROUGH ACROSS THE EAST BY FRIDAY.
THE CURRENT RADAR SHOWS A BAND OF LIGHT RAIN FROM SOUTH CENTRAL
INDIANA DOWN THROUGH WESTERN KENTUCKY. THE LATEST HRRR SHOWS THIS
ACTIVITY MAKING IT TO OUR DOORSTEP BY DAWN OR SHORTLY THEREAFTER...
ALTHOUGH THERE IS GOOD AGREEMENT THAT THE MAJORITY OF THE MEASURABLE
PRECIPITATION WILL STAY JUST NORTH...WITH MORE SPOTTIER ACTIVITY TO
CONTEND WITH ACROSS OUR AREA THROUGH 14Z. AFTER 14Z...PRECIPITATION
LOOKS TO BLOSSOM AS THE BETTER FORCING ARRIVES. HAVE BEEN CONCERNED
WITH THE COLD VALLEY READINGS ACROSS OUR AREA...HOWEVER IT LOOKS AS
THOUGH THAT BY THE TIME THE BETTER PRECIPITATION DOES MOVE IN...THAT
MOST LOCATIONS WILL BE ABOVE FREEZING. AS SUCH...WILL ISSUE A SPECIAL
WEATHER STATEMENT COVERING THE SPOTTIER PRECIPITATION AT ONSET...AS
MAINLY INTERIOR LOCATIONS WILL STILL LIKELY BE BELOW FREEZING. WILL
CONTINUE TO MONITOR TRENDS VERY CLOSELY OVER THE NEXT FEW HOURS SINCE
ANY RAMP UP IN THE PRECIPITATION WILL MEAN AN ICY COMMUTE POTENTIALLY.
ONCE THE FIRST BATCH OF PRECIP MOVES THROUGH LATER THIS MORNING INTO
EARLY THIS AFTERNOON...THERE WILL LIKELY BE A LULL IN THE
ACTIVITY...BEFORE THE COLDER AIR ARRIVES ON NORTHWEST WINDS AND THE
TROUGH AXIS MOVES THROUGH TONIGHT. THIS WILL ALLOW FOR SOME LIGHT
SNOW ACROSS THE AREA. SNOW SHOWERS WILL LIKELY LINGER IN THE EAST
THROUGH FRIDAY MORNING...BEFORE TAPERING OFF. ANY LIGHT ACCUMULATIONS
WILL FAVOR THE HIGHER TERRAIN IN THE FAR SOUTHEAST.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 446 AM EST THU JAN 29 2015
HIGH PRESSURE WILL TAKE HOLD OF SENSIBLE WEATHER TO BEGIN THIS
PERIOD. WHILE LOW PRESSURE THAT IS AFFECTING THE REGION TODAY
DEVELOPS INTO ANOTHER STRONG COASTAL LOW ACROSS THE NORTHEAST US.
THIS HIGH PRESSURE COUPLED WITH DECREASING CLOUDS WILL ALLOW FOR
DECOUPLING AND LOWS DROPPING DOWN INTO THE MID TO UPPER TEENS
AREA WIDE. THIS HIGH PRESSURE WILL ALLOW MOSTLY SUNNY SKIES EARLY IN
THE DAY FOR YOUR SATURDAY WITH INCREASING CLOUDS IN THE AFTERNOON.
WINDS WILL ALSO BECOME MORE SOUTHWEST BRINGING HIGHS ON SATURDAY INTO
THE UPPER 30S TO LOWER 40S.
NOW THE BIGGER CONCERN CONTINUES TO BE LATE WEEKEND STORM AND
CONFIDENCE REMAINS LOW IN REGARDS TO THIS SYSTEM. THE SETUP IS WE
HAVE A DEVELOPING UPPER LEVEL CLOSED LOW ACROSS THE NORTHERN BAJA
PENINSULA AND ASSOCIATED DEVELOPING SURFACE LOW SATURDAY MORNING.
MEANWHILE A UPPER LEVEL WAVE RIDES OVER RIDGING ACROSS THE NORTHWEST
US. THEN THIS IS WHERE THE MODELS CONTINUE TO STRUGGLE IS IN THE
PHASING PROCESS THAT OCCURS SATURDAY NIGHT IN THE UPPER LEVELS.
EARLIER THE 18Z/28 GFS AND 12Z/28 ECMWF HAD A MORE OPEN WAVE WHICH
TRANSLATED TO A WEAKER SURFACE LOW. THIS WAS NEW BASED ON THE
PREVIOUS RUNS SEEN OVER THE PAST COUPLE OF DAYS. THE LATEST 00Z/29
RUN OF THE GFS DEVELOPS A STRONGER LOW WITH A BIT OF A DEEPER TROUGH
SETTING UP. THE 00Z/29 ECMWF DOES HAVE SIMILARITIES...HOWEVER THE
SURFACE LOW PRESSURE IS NOT AS DEEP. ONE THING THAT REMAINS WITH BOTH
MODELS 00Z RUNS IS BOTH HAVE A GOOD AMT OF QPF RESPECTIVELY. ANOTHER
QUESTION THAT REMAINS IS HOW MUCH COLD AIR STAYS IN PLACE WITH THIS
SYSTEM ON SUNDAY AND THIS WILL DEPEND HEAVILY ON THE EVENTUAL TRACK
OF THIS SURFACE LOW. THAT SAID HAVE LEANED TOWARD A BIT COLDER
THROUGH THE DAY ON SUNDAY. THINKING STILL MUCH OF SUNDAY WOULD LEAD
TO MIXING ACROSS MUCH OF THE CWA WITH MORE IN THE WAY OF SNOW ACROSS
THE BLUEGRASS WHERE TEMPS REMAIN COOLER...HOWEVER CONFIDENCE IN THIS
SYSTEM REMAINS LOW GIVEN THE DRASTIC RUN TO RUN CHANGES SEEN IN THE
DETERMINISTIC MODELS. ALSO KEEPING IN MIND THAT THE ENSEMBLE MEAN HAS
BEEN QUITE ERRATIC AND GIVEN THAT THE 12 PERTURBATIONS IN OUR SYSTEM
ARE ERRATIC EXPLAINS THE LACK OF CONTINUITY. ALL THIS SAID STILL
THINK THERE IS A REASONABLE SHOT OF MEASURABLE SNOW SUNDAY INTO
MONDAY. ANOTHER PIECE TO THE PUZZLE TO KEEP IN MIND IS THAT A MORE
NORTHERLY TRACK SHOWN IN EARLIER RUNS COULD ALLOW FOR MORE SOUTHERLY
FLOW AND WARMER AIR AND LEAD TO LESSENING SNOWFALL TOTALS. ALTHOUGH
BEHIND THIS SYSTEM EXPECT COLD AIR TO FILTER INTO ALL OF THE CWA
SUNDAY NIGHT INTO MONDAY. ALSO WOULD EXPECT GENERALLY FALLING
TEMPERATURES DURING THE DAY ON MONDAY.
AFTER THIS THE AFOREMENTIONED LOW PRESSURE IS THEN FORECAST TO TRACK NE
AND CONTINUE TO DEEPEN ALONG NE ATLANTIC COAST. HIGH PRESSURE WILL
BUILD EAST MONDAY NIGHT AND EXPECT ANOTHER COLD NIGHT WITH GENERALLY
LOW TO MID TEENS ACROSS THE REGION. THESE TEMPS MAY HAVE TO BE
ADJUSTED FURTHER DEPENDING UPON IF WE RECEIVE MEASURABLE SNOW. THIS
HIGH PRESSURE WILL ADVANCE EAST OF THE REGION MOVING INTO THE DAY ON
TUESDAY BRINGING RETURN FLOW AND WELCOMING REBOUND IN
TEMPERATURE...WITH HIGHS IN THE MID TO UPPER 30S. THAT SAID WEDNESDAY
REMAINS UNCERTAIN WITH YET ANOTHER SYSTEM DEVELOPING AND AT THIS POINT
STUCK CLOSE TO THE BLEND. DID INTRODUCE MAINLY SLIGHT POPS DURING
THAT PORTION OF THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 844 AM EST THU JAN 29 2015
A PASSING COLD FRONT WILL BRING LOWERING CEILINGS...PRECIPITATION...
AND GUSTY SOUTH TO SOUTHWEST WINDS TO THE AREA THROUGH THIS EVENING.
VFR CONDITIONS WILL LIKELY HOLD ON THROUGH THE EARLY
AFTERNOON...BEFORE CEILINGS LIKELY COME DOWN QUICKLY TO MVFR/IFR ONCE
THE FRONT MOVES THROUGH THE AREA LATER THIS AFTERNOON INTO EARLY THIS
EVENING. PRECIPITATION WILL TAPER OFF THIS MORNING...AND THEN LOOKS
TO PICK UP AGAIN TONIGHT AS AN UPPER TROUGH AXIS MOVES ACROSS THE OHIO
AND TENNESSEE VALLEYS. COLDER AIR WILL MOVE IN ON NORTHWEST
WINDS...WITH RAIN CHANGING OVER TO SNOW. SOUTH TO SOUTHWEST WINDS OF
10 TO 15 KTS...WITH GUSTS IN THE 15 TO 20 KT RANGE WILL SHIFT TO THE
WEST AND EVENTUALLY NORTHWEST. THE WINDS WILL DIMINISH AND BECOME
LESS GUSTY AFTER DUSK.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HAL
SHORT TERM...GEOGERIAN
LONG TERM...DJ
AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION
NWS JACKSON KY
1014 AM EST THU JAN 29 2015
.UPDATE...
ISSUED AT 1013 AM EST THU JAN 29 2015
WITH REPORTS OF MANY ACCIDENTS...ISSUED AN FREEZING RAIN ADVISORY FOR
LOCATIONS WHERE VALLEYS TEMPS ARE BELOW FREEZING AND PRECIP IS STILL
OCCURRING. TEMPS ARE WARMING...SO THE ADVISORY ONLY RUNS FOR ABOUT
ANOTHER HOUR. WILL EVALUATE TEMPS IN A WHILE TO SEE IF IT CAN EXPIRE.
UPDATE ISSUED AT 844 AM EST THU JAN 29 2015
PRECIP SHIELD HAS MADE INTO OUR WESTERN FORECAST AREA. TEMPERATURES
HAVE RESPONDED WELL WHERE MEASURABLE PRECIPITATION IS
FALLING...HOWEVER SOME VALLEYS IN THE EAST STILL LINGER IN THE MID
20S. LOOKING AT RADAR TRENDS...THE MEASURABLE PRECIPITATION SEEMS TO
BE HAVING A HARDER TIME COMING EAST WITH SOME DOWNSLOPE FLOW IN
PLACE...AND READINGS HAVE BEEN EDGING UP EVEN IN THE COLDER SPOTS
PRIOR TO THE PRECIP ARRIVING. HAVE BEEFED UP POPS TO CATEGORICAL
ACROSS THE BOARD...AND WILL CONTINUE TO MENTION A CHANCE OF FREEZING
RAIN...AS SOME SPOTTY SLICK SPOTS STILL LOOK POSSIBLE. UPDATES HAVE
BEEN SENT.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 400 AM EST THU JAN 29 2015
LATEST SURFACE MAP FEATURES HIGH PRESSURE ALONG THE EASTERN
CONUS...WITH LOW PRESSURE MOVING INTO THE GREAT LAKES AND OHIO VALLEY
REGIONS. ALOFT...A SHORT WAVE TROUGH IS ROTATING TOWARDS THE OHIO
VALLEY...WITH ANOTHER TROUGH DROPPING SOUTHEAST INTO THE NORTHERN
PLAINS...AND YET ONE MORE MOVING IN ACROSS SOUTH CENTRAL CANADA.
MAINLY MID AND HIGH LEVEL CLOUDS HAVE BEEN STREAMING IN ACROSS
EASTERN KENTUCKY. THE SOUTHERLY WIND FLOW OUT AHEAD OF THE
APPROACHING SURFACE LOW HAS ALLOWED FOR A NICE RIDGE/VALLEY SPLIT
ACROSS THE AREA...WITH MORE SHELTERED VALLEYS HOLDING IN THE LOW AND
MID 20S...WHILE RIDGETOPS ARE IN THE LOW TO MID 30S.
THE MODELS ARE IN GOOD AGREEMENT THROUGH THE SHORT TERM...TAKING THE
LOW PRESSURE SYSTEM EAST ACROSS THE OHIO VALLEY DURING THE DAY...AND
ALLOWING THE ASSOCIATED SURFACE COLD FRONT TO MOVE THROUGH THE AREA
THIS AFTERNOON INTO EARLY THIS EVENING. MEANWHILE...THE MORE NORTHERN
SHORT WAVES WILL CONTINUE TO DROP SOUTHEAST IN SUCCESSION...HELPING
TO ESTABLISH A DEEP TROUGH ACROSS THE EAST BY FRIDAY.
THE CURRENT RADAR SHOWS A BAND OF LIGHT RAIN FROM SOUTH CENTRAL
INDIANA DOWN THROUGH WESTERN KENTUCKY. THE LATEST HRRR SHOWS THIS
ACTIVITY MAKING IT TO OUR DOORSTEP BY DAWN OR SHORTLY THEREAFTER...
ALTHOUGH THERE IS GOOD AGREEMENT THAT THE MAJORITY OF THE MEASURABLE
PRECIPITATION WILL STAY JUST NORTH...WITH MORE SPOTTIER ACTIVITY TO
CONTEND WITH ACROSS OUR AREA THROUGH 14Z. AFTER 14Z...PRECIPITATION
LOOKS TO BLOSSOM AS THE BETTER FORCING ARRIVES. HAVE BEEN CONCERNED
WITH THE COLD VALLEY READINGS ACROSS OUR AREA...HOWEVER IT LOOKS AS
THOUGH THAT BY THE TIME THE BETTER PRECIPITATION DOES MOVE IN...THAT
MOST LOCATIONS WILL BE ABOVE FREEZING. AS SUCH...WILL ISSUE A SPECIAL
WEATHER STATEMENT COVERING THE SPOTTIER PRECIPITATION AT ONSET...AS
MAINLY INTERIOR LOCATIONS WILL STILL LIKELY BE BELOW FREEZING. WILL
CONTINUE TO MONITOR TRENDS VERY CLOSELY OVER THE NEXT FEW HOURS SINCE
ANY RAMP UP IN THE PRECIPITATION WILL MEAN AN ICY COMMUTE POTENTIALLY.
ONCE THE FIRST BATCH OF PRECIP MOVES THROUGH LATER THIS MORNING INTO
EARLY THIS AFTERNOON...THERE WILL LIKELY BE A LULL IN THE
ACTIVITY...BEFORE THE COLDER AIR ARRIVES ON NORTHWEST WINDS AND THE
TROUGH AXIS MOVES THROUGH TONIGHT. THIS WILL ALLOW FOR SOME LIGHT
SNOW ACROSS THE AREA. SNOW SHOWERS WILL LIKELY LINGER IN THE EAST
THROUGH FRIDAY MORNING...BEFORE TAPERING OFF. ANY LIGHT ACCUMULATIONS
WILL FAVOR THE HIGHER TERRAIN IN THE FAR SOUTHEAST.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 446 AM EST THU JAN 29 2015
HIGH PRESSURE WILL TAKE HOLD OF SENSIBLE WEATHER TO BEGIN THIS
PERIOD. WHILE LOW PRESSURE THAT IS AFFECTING THE REGION TODAY
DEVELOPS INTO ANOTHER STRONG COASTAL LOW ACROSS THE NORTHEAST US.
THIS HIGH PRESSURE COUPLED WITH DECREASING CLOUDS WILL ALLOW FOR
DECOUPLING AND LOWS DROPPING DOWN INTO THE MID TO UPPER TEENS
AREA WIDE. THIS HIGH PRESSURE WILL ALLOW MOSTLY SUNNY SKIES EARLY IN
THE DAY FOR YOUR SATURDAY WITH INCREASING CLOUDS IN THE AFTERNOON.
WINDS WILL ALSO BECOME MORE SOUTHWEST BRINGING HIGHS ON SATURDAY INTO
THE UPPER 30S TO LOWER 40S.
NOW THE BIGGER CONCERN CONTINUES TO BE LATE WEEKEND STORM AND
CONFIDENCE REMAINS LOW IN REGARDS TO THIS SYSTEM. THE SETUP IS WE
HAVE A DEVELOPING UPPER LEVEL CLOSED LOW ACROSS THE NORTHERN BAJA
PENINSULA AND ASSOCIATED DEVELOPING SURFACE LOW SATURDAY MORNING.
MEANWHILE A UPPER LEVEL WAVE RIDES OVER RIDGING ACROSS THE NORTHWEST
US. THEN THIS IS WHERE THE MODELS CONTINUE TO STRUGGLE IS IN THE
PHASING PROCESS THAT OCCURS SATURDAY NIGHT IN THE UPPER LEVELS.
EARLIER THE 18Z/28 GFS AND 12Z/28 ECMWF HAD A MORE OPEN WAVE WHICH
TRANSLATED TO A WEAKER SURFACE LOW. THIS WAS NEW BASED ON THE
PREVIOUS RUNS SEEN OVER THE PAST COUPLE OF DAYS. THE LATEST 00Z/29
RUN OF THE GFS DEVELOPS A STRONGER LOW WITH A BIT OF A DEEPER TROUGH
SETTING UP. THE 00Z/29 ECMWF DOES HAVE SIMILARITIES...HOWEVER THE
SURFACE LOW PRESSURE IS NOT AS DEEP. ONE THING THAT REMAINS WITH BOTH
MODELS 00Z RUNS IS BOTH HAVE A GOOD AMT OF QPF RESPECTIVELY. ANOTHER
QUESTION THAT REMAINS IS HOW MUCH COLD AIR STAYS IN PLACE WITH THIS
SYSTEM ON SUNDAY AND THIS WILL DEPEND HEAVILY ON THE EVENTUAL TRACK
OF THIS SURFACE LOW. THAT SAID HAVE LEANED TOWARD A BIT COLDER
THROUGH THE DAY ON SUNDAY. THINKING STILL MUCH OF SUNDAY WOULD LEAD
TO MIXING ACROSS MUCH OF THE CWA WITH MORE IN THE WAY OF SNOW ACROSS
THE BLUEGRASS WHERE TEMPS REMAIN COOLER...HOWEVER CONFIDENCE IN THIS
SYSTEM REMAINS LOW GIVEN THE DRASTIC RUN TO RUN CHANGES SEEN IN THE
DETERMINISTIC MODELS. ALSO KEEPING IN MIND THAT THE ENSEMBLE MEAN HAS
BEEN QUITE ERRATIC AND GIVEN THAT THE 12 PERTURBATIONS IN OUR SYSTEM
ARE ERRATIC EXPLAINS THE LACK OF CONTINUITY. ALL THIS SAID STILL
THINK THERE IS A REASONABLE SHOT OF MEASURABLE SNOW SUNDAY INTO
MONDAY. ANOTHER PIECE TO THE PUZZLE TO KEEP IN MIND IS THAT A MORE
NORTHERLY TRACK SHOWN IN EARLIER RUNS COULD ALLOW FOR MORE SOUTHERLY
FLOW AND WARMER AIR AND LEAD TO LESSENING SNOWFALL TOTALS. ALTHOUGH
BEHIND THIS SYSTEM EXPECT COLD AIR TO FILTER INTO ALL OF THE CWA
SUNDAY NIGHT INTO MONDAY. ALSO WOULD EXPECT GENERALLY FALLING
TEMPERATURES DURING THE DAY ON MONDAY.
AFTER THIS THE AFOREMENTIONED LOW PRESSURE IS THEN FORECAST TO TRACK NE
AND CONTINUE TO DEEPEN ALONG NE ATLANTIC COAST. HIGH PRESSURE WILL
BUILD EAST MONDAY NIGHT AND EXPECT ANOTHER COLD NIGHT WITH GENERALLY
LOW TO MID TEENS ACROSS THE REGION. THESE TEMPS MAY HAVE TO BE
ADJUSTED FURTHER DEPENDING UPON IF WE RECEIVE MEASURABLE SNOW. THIS
HIGH PRESSURE WILL ADVANCE EAST OF THE REGION MOVING INTO THE DAY ON
TUESDAY BRINGING RETURN FLOW AND WELCOMING REBOUND IN
TEMPERATURE...WITH HIGHS IN THE MID TO UPPER 30S. THAT SAID WEDNESDAY
REMAINS UNCERTAIN WITH YET ANOTHER SYSTEM DEVELOPING AND AT THIS POINT
STUCK CLOSE TO THE BLEND. DID INTRODUCE MAINLY SLIGHT POPS DURING
THAT PORTION OF THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 844 AM EST THU JAN 29 2015
A PASSING COLD FRONT WILL BRING LOWERING CEILINGS...PRECIPITATION...
AND GUSTY SOUTH TO SOUTHWEST WINDS TO THE AREA THROUGH THIS EVENING.
VFR CONDITIONS WILL LIKELY HOLD ON THROUGH THE EARLY
AFTERNOON...BEFORE CEILINGS LIKELY COME DOWN QUICKLY TO MVFR/IFR ONCE
THE FRONT MOVES THROUGH THE AREA LATER THIS AFTERNOON INTO EARLY THIS
EVENING. PRECIPITATION WILL TAPER OFF THIS MORNING...AND THEN LOOKS
TO PICK UP AGAIN TONIGHT AS AN UPPER TROUGH AXIS MOVES ACROSS THE OHIO
AND TENNESSEE VALLEYS. COLDER AIR WILL MOVE IN ON NORTHWEST
WINDS...WITH RAIN CHANGING OVER TO SNOW. SOUTH TO SOUTHWEST WINDS OF
10 TO 15 KTS...WITH GUSTS IN THE 15 TO 20 KT RANGE WILL SHIFT TO THE
WEST AND EVENTUALLY NORTHWEST. THE WINDS WILL DIMINISH AND BECOME
LESS GUSTY AFTER DUSK.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
FREEZING RAIN ADVISORY UNTIL 11 AM EST THIS MORNING FOR KYZ107-
109-110-112-113-115-117-119-120.
&&
$$
UPDATE...HAL
SHORT TERM...GEOGERIAN
LONG TERM...DJ
AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION
NWS PADUCAH KY
905 AM CST Thu Jan 29 2015
.UPDATE...
Issued at 905 AM CST THU JAN 29 2015
The forecast has been updated to catch up to the cloud and
temperature trends. Much of west Kentucky will have highs greater
than forecast late this morning. Also, the latest HRRR has no
precipitation over the area through the day, so removed all
measurable PoPs. Would not rule out some patchy drizzle across the
Evansville Tri State region this afternoon, but will add that in
once it becomes more obvious.
UPDATE issued at 545 AM CST Thu Jan 29 2015
Updated aviation section for 12z tafs
&&
.SHORT TERM (Today through Saturday)...
Issued at 255 AM CST Thu Jan 29 2015
A well-defined cold front will move quickly southeast across our
region this morning. A small line of showers developed well ahead
of the front from kowb to khop early this morning. Cannot rule out
another small line until the front passes to our east. For most of
the forecast area, this will be a dry frontal passage.
Behind the front, winds will shift into the northwest and become
rather gusty today. Some gusts around 25 knots are likely. NAM and
GFS 925 mb rh progs indicate widespread low cloudiness will arrive
behind the front and persist through the afternoon. Low level cold
advection and widespread cloudiness should result in a steady or
slowly falling temperature trend this afternoon. Highs will be in
the morning. A period of sunshine prior to the arrival of low
clouds could push temps up from their 08z readings in the mid 40s
to lower 50s.
The main forecast issue for tonight is when and if the low clouds
will clear out. 925 mb rh forecasts from the 00z nam and gfs are
quite moist all night, especially east of the Mississippi River.
The forecast will show partial clearing from west to east tonight,
but at a slower rate than previous forecasts. Lows will be in the
mid to upper 20s.
Friday still looks mostly sunny, although there may still be some
morning low clouds in southwest Indiana and northwest Kentucky.
Winds will decrease as surface high pressure reaches the mid and
upper Mississippi Valley. Highs should be quite cold considering
the amount of sun, ranging from the mid 30s to lower 40s.
Friday night and Saturday...mid and high clouds will gradually
increase ahead of the next system. The low levels will be
extremely dry, which should make it very difficult for precip to
reach the ground. Will keep in a slight chance of showers in the
Ozark foothills of southeast Missouri. Despite the clouds, highs
should be mainly in the lower and mid 40s due to southerly winds.
.LONG TERM (Saturday night through Wednesday)...
Issued at 300 AM CST Thu Jan 29 2015
Main forecast challenge in this time frame comes with the storm
system that looks to be impacting the region over the weekend,
especially Sunday. Forecast confidence remains fairly low at this
time regarding precip types.
As we begin the period, split mid/upper flow pattern should be in
place...with nrn branch trof digging se into the Plains and a nearly
stationary srn branch low in place over the Baja of CA. It now looks
as though the srn branch low will feed pacific moisture into the nrn
branch...leading to fairly widespread precip shield over the mid MS
River and Ohio Valleys Saturday night and esp Sunday as sfc low
pressure develops over the Gulf Coast states. As mentioned, the main
uncertainly at this time lies with precip type. The latest 00z runs
of the operational GFS and ECMWF are now in decent agreement that
the sfc low and inverted trof will remain farther south over
MS/AL...as a 1040 mb sfc high presses south into the nrn Plains.
This would result in a colder thermal profile than we were thinking
yesterday. Snow would be the main precip type over all except our
far southern counties, with some potential for a few inches, esp
along and north/west of the Ohio River. On the other hand for
example, 00Z NAM/GEM both bring the sfc low farther north, and are
thus much warmer in their thermal profiles. For this package, will
keep much of the nrn half of the forecast area mostly snow, and go
with rain/snow for now over much of wrn KY and se MO. Again,
uncertainty is still quite high and things are likely to change one
way or another as we get closer to the event.
Very cold air will follow in the wake of the system as Canadian high
pressure moves se into the region. Most locations will fall into the
teens later Sunday night and Monday night. Highs Monday will likely
remain below freezing. Of course, things could be even colder if any
areas manage to get a fresh layer of snow on the ground. The next
clipper system Tue/Tue night is expected to stay much farther north
and cross over the Great lakes region. May be some light precip as
it drags another cold front across the region, but most impacts with
this low are expected to remain north of the forecast area.
&&
.AVIATION...
Issued at 545 AM CST Thu Jan 29 2015
The back edge of mid level clouds and sprinkles will move east of
the kevv/kowb area early this morning. Clear skies are expected for
a few hours before a strong cold front moves through around mid
morning. As the front passes, winds will shift into the
west/northwest and gust around 25 knots. A solid deck of mvfr cigs
will also arrive as the front passes. The mvfr cigs will likely be
slow to depart. In fact, the kevv/kowb sites should remain overcast
through Friday morning. Winds will diminish to around 10 knots
around sunset.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...DRS
SHORT TERM...MY
LONG TERM....GM
AVIATION...MY
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
844 AM EST THU JAN 29 2015
.UPDATE...
ISSUED AT 844 AM EST THU JAN 29 2015
PRECIP SHIELD HAS MADE INTO OUR WESTERN FORECAST AREA. TEMPERATURES
HAVE RESPONDED WELL WHERE MEASURABLE PRECIPITATION IS
FALLING...HOWEVER SOME VALLEYS IN THE EAST STILL LINGER IN THE MID
20S. LOOKING AT RADAR TRENDS...THE MEASURABLE PRECIPITATION SEEMS TO
BE HAVING A HARDER TIME COMING EAST WITH SOME DOWNSLOPE FLOW IN
PLACE...AND READINGS HAVE BEEN EDGING UP EVEN IN THE COLDER SPOTS
PRIOR TO THE PRECIP ARRIVING. HAVE BEEFED UP POPS TO CATEGORICAL
ACROSS THE BOARD...AND WILL CONTINUE TO MENTION A CHANCE OF FREEZING
RAIN...AS SOME SPOTTY SLICK SPOTS STILL LOOK POSSIBLE. UPDATES HAVE
BEEN SENT.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 400 AM EST THU JAN 29 2015
LATEST SURFACE MAP FEATURES HIGH PRESSURE ALONG THE EASTERN
CONUS...WITH LOW PRESSURE MOVING INTO THE GREAT LAKES AND OHIO VALLEY
REGIONS. ALOFT...A SHORT WAVE TROUGH IS ROTATING TOWARDS THE OHIO
VALLEY...WITH ANOTHER TROUGH DROPPING SOUTHEAST INTO THE NORTHERN
PLAINS...AND YET ONE MORE MOVING IN ACROSS SOUTH CENTRAL CANADA.
MAINLY MID AND HIGH LEVEL CLOUDS HAVE BEEN STREAMING IN ACROSS
EASTERN KENTUCKY. THE SOUTHERLY WIND FLOW OUT AHEAD OF THE
APPROACHING SURFACE LOW HAS ALLOWED FOR A NICE RIDGE/VALLEY SPLIT
ACROSS THE AREA...WITH MORE SHELTERED VALLEYS HOLDING IN THE LOW AND
MID 20S...WHILE RIDGETOPS ARE IN THE LOW TO MID 30S.
THE MODELS ARE IN GOOD AGREEMENT THROUGH THE SHORT TERM...TAKING THE
LOW PRESSURE SYSTEM EAST ACROSS THE OHIO VALLEY DURING THE DAY...AND
ALLOWING THE ASSOCIATED SURFACE COLD FRONT TO MOVE THROUGH THE AREA
THIS AFTERNOON INTO EARLY THIS EVENING. MEANWHILE...THE MORE NORTHERN
SHORT WAVES WILL CONTINUE TO DROP SOUTHEAST IN SUCCESSION...HELPING
TO ESTABLISH A DEEP TROUGH ACROSS THE EAST BY FRIDAY.
THE CURRENT RADAR SHOWS A BAND OF LIGHT RAIN FROM SOUTH CENTRAL
INDIANA DOWN THROUGH WESTERN KENTUCKY. THE LATEST HRRR SHOWS THIS
ACTIVITY MAKING IT TO OUR DOORSTEP BY DAWN OR SHORTLY THEREAFTER...
ALTHOUGH THERE IS GOOD AGREEMENT THAT THE MAJORITY OF THE MEASURABLE
PRECIPITATION WILL STAY JUST NORTH...WITH MORE SPOTTIER ACTIVITY TO
CONTEND WITH ACROSS OUR AREA THROUGH 14Z. AFTER 14Z...PRECIPITATION
LOOKS TO BLOSSOM AS THE BETTER FORCING ARRIVES. HAVE BEEN CONCERNED
WITH THE COLD VALLEY READINGS ACROSS OUR AREA...HOWEVER IT LOOKS AS
THOUGH THAT BY THE TIME THE BETTER PRECIPITATION DOES MOVE IN...THAT
MOST LOCATIONS WILL BE ABOVE FREEZING. AS SUCH...WILL ISSUE A SPECIAL
WEATHER STATEMENT COVERING THE SPOTTIER PRECIPITATION AT ONSET...AS
MAINLY INTERIOR LOCATIONS WILL STILL LIKELY BE BELOW FREEZING. WILL
CONTINUE TO MONITOR TRENDS VERY CLOSELY OVER THE NEXT FEW HOURS SINCE
ANY RAMP UP IN THE PRECIPITATION WILL MEAN AN ICY COMMUTE POTENTIALLY.
ONCE THE FIRST BATCH OF PRECIP MOVES THROUGH LATER THIS MORNING INTO
EARLY THIS AFTERNOON...THERE WILL LIKELY BE A LULL IN THE
ACTIVITY...BEFORE THE COLDER AIR ARRIVES ON NORTHWEST WINDS AND THE
TROUGH AXIS MOVES THROUGH TONIGHT. THIS WILL ALLOW FOR SOME LIGHT
SNOW ACROSS THE AREA. SNOW SHOWERS WILL LIKELY LINGER IN THE EAST
THROUGH FRIDAY MORNING...BEFORE TAPERING OFF. ANY LIGHT ACCUMULATIONS
WILL FAVOR THE HIGHER TERRAIN IN THE FAR SOUTHEAST.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 446 AM EST THU JAN 29 2015
HIGH PRESSURE WILL TAKE HOLD OF SENSIBLE WEATHER TO BEGIN THIS
PERIOD. WHILE LOW PRESSURE THAT IS AFFECTING THE REGION TODAY
DEVELOPS INTO ANOTHER STRONG COASTAL LOW ACROSS THE NORTHEAST US.
THIS HIGH PRESSURE COUPLED WITH DECREASING CLOUDS WILL ALLOW FOR
DECOUPLING AND LOWS DROPPING DOWN INTO THE MID TO UPPER TEENS
AREA WIDE. THIS HIGH PRESSURE WILL ALLOW MOSTLY SUNNY SKIES EARLY IN
THE DAY FOR YOUR SATURDAY WITH INCREASING CLOUDS IN THE AFTERNOON.
WINDS WILL ALSO BECOME MORE SOUTHWEST BRINGING HIGHS ON SATURDAY INTO
THE UPPER 30S TO LOWER 40S.
NOW THE BIGGER CONCERN CONTINUES TO BE LATE WEEKEND STORM AND
CONFIDENCE REMAINS LOW IN REGARDS TO THIS SYSTEM. THE SETUP IS WE
HAVE A DEVELOPING UPPER LEVEL CLOSED LOW ACROSS THE NORTHERN BAJA
PENINSULA AND ASSOCIATED DEVELOPING SURFACE LOW SATURDAY MORNING.
MEANWHILE A UPPER LEVEL WAVE RIDES OVER RIDGING ACROSS THE NORTHWEST
US. THEN THIS IS WHERE THE MODELS CONTINUE TO STRUGGLE IS IN THE
PHASING PROCESS THAT OCCURS SATURDAY NIGHT IN THE UPPER LEVELS.
EARLIER THE 18Z/28 GFS AND 12Z/28 ECMWF HAD A MORE OPEN WAVE WHICH
TRANSLATED TO A WEAKER SURFACE LOW. THIS WAS NEW BASED ON THE
PREVIOUS RUNS SEEN OVER THE PAST COUPLE OF DAYS. THE LATEST 00Z/29
RUN OF THE GFS DEVELOPS A STRONGER LOW WITH A BIT OF A DEEPER TROUGH
SETTING UP. THE 00Z/29 ECMWF DOES HAVE SIMILARITIES...HOWEVER THE
SURFACE LOW PRESSURE IS NOT AS DEEP. ONE THING THAT REMAINS WITH BOTH
MODELS 00Z RUNS IS BOTH HAVE A GOOD AMT OF QPF RESPECTIVELY. ANOTHER
QUESTION THAT REMAINS IS HOW MUCH COLD AIR STAYS IN PLACE WITH THIS
SYSTEM ON SUNDAY AND THIS WILL DEPEND HEAVILY ON THE EVENTUAL TRACK
OF THIS SURFACE LOW. THAT SAID HAVE LEANED TOWARD A BIT COLDER
THROUGH THE DAY ON SUNDAY. THINKING STILL MUCH OF SUNDAY WOULD LEAD
TO MIXING ACROSS MUCH OF THE CWA WITH MORE IN THE WAY OF SNOW ACROSS
THE BLUEGRASS WHERE TEMPS REMAIN COOLER...HOWEVER CONFIDENCE IN THIS
SYSTEM REMAINS LOW GIVEN THE DRASTIC RUN TO RUN CHANGES SEEN IN THE
DETERMINISTIC MODELS. ALSO KEEPING IN MIND THAT THE ENSEMBLE MEAN HAS
BEEN QUITE ERRATIC AND GIVEN THAT THE 12 PERTURBATIONS IN OUR SYSTEM
ARE ERRATIC EXPLAINS THE LACK OF CONTINUITY. ALL THIS SAID STILL
THINK THERE IS A REASONABLE SHOT OF MEASURABLE SNOW SUNDAY INTO
MONDAY. ANOTHER PIECE TO THE PUZZLE TO KEEP IN MIND IS THAT A MORE
NORTHERLY TRACK SHOWN IN EARLIER RUNS COULD ALLOW FOR MORE SOUTHERLY
FLOW AND WARMER AIR AND LEAD TO LESSENING SNOWFALL TOTALS. ALTHOUGH
BEHIND THIS SYSTEM EXPECT COLD AIR TO FILTER INTO ALL OF THE CWA
SUNDAY NIGHT INTO MONDAY. ALSO WOULD EXPECT GENERALLY FALLING
TEMPERATURES DURING THE DAY ON MONDAY.
AFTER THIS THE AFOREMENTIONED LOW PRESSURE IS THEN FORECAST TO TRACK NE
AND CONTINUE TO DEEPEN ALONG NE ATLANTIC COAST. HIGH PRESSURE WILL
BUILD EAST MONDAY NIGHT AND EXPECT ANOTHER COLD NIGHT WITH GENERALLY
LOW TO MID TEENS ACROSS THE REGION. THESE TEMPS MAY HAVE TO BE
ADJUSTED FURTHER DEPENDING UPON IF WE RECEIVE MEASURABLE SNOW. THIS
HIGH PRESSURE WILL ADVANCE EAST OF THE REGION MOVING INTO THE DAY ON
TUESDAY BRINGING RETURN FLOW AND WELCOMING REBOUND IN
TEMPERATURE...WITH HIGHS IN THE MID TO UPPER 30S. THAT SAID WEDNESDAY
REMAINS UNCERTAIN WITH YET ANOTHER SYSTEM DEVELOPING AND AT THIS POINT
STUCK CLOSE TO THE BLEND. DID INTRODUCE MAINLY SLIGHT POPS DURING
THAT PORTION OF THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 844 AM EST THU JAN 29 2015
A PASSING COLD FRONT WILL BRING LOWERING CEILINGS...PRECIPITATION...
AND GUSTY SOUTH TO SOUTHWEST WINDS TO THE AREA THROUGH THIS EVENING.
VFR CONDITIONS WILL LIKELY HOLD ON THROUGH THE EARLY
AFTERNOON...BEFORE CEILINGS LIKELY COME DOWN QUICKLY TO MVFR/IFR ONCE
THE FRONT MOVES THROUGH THE AREA LATER THIS AFTERNOON INTO EARLY THIS
EVENING. PRECIPITATION WILL TAPER OFF THIS MORNING...AND THEN LOOKS
TO PICK UP AGAIN TONIGHT AS AN UPPER TROUGH AXIS MOVES ACROSS THE OHIO
AND TENNESSEE VALLEYS. COLDER AIR WILL MOVE IN ON NORTHWEST
WINDS...WITH RAIN CHANGING OVER TO SNOW. SOUTH TO SOUTHWEST WINDS OF
10 TO 15 KTS...WITH GUSTS IN THE 15 TO 20 KT RANGE WILL SHIFT TO THE
WEST AND EVENTUALLY NORTHWEST. THE WINDS WILL DIMINISH AND BECOME
LESS GUSTY AFTER DUSK.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEOGERIAN
SHORT TERM...GEOGERIAN
LONG TERM...DJ
AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION
NWS JACKSON KY
450 AM EST THU JAN 29 2015
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 400 AM EST THU JAN 29 2015
LATEST SURFACE MAP FEATURES HIGH PRESSURE ALONG THE EASTERN
CONUS...WITH LOW PRESSURE MOVING INTO THE GREAT LAKES AND OHIO VALLEY
REGIONS. ALOFT...A SHORT WAVE TROUGH IS ROTATING TOWARDS THE OHIO
VALLEY...WITH ANOTHER TROUGH DROPPING SOUTHEAST INTO THE NORTHERN
PLAINS...AND YET ONE MORE MOVING IN ACROSS SOUTH CENTRAL CANADA.
MAINLY MID AND HIGH LEVEL CLOUDS HAVE BEEN STREAMING IN ACROSS
EASTERN KENTUCKY. THE SOUTHERLY WIND FLOW OUT AHEAD OF THE
APPROACHING SURFACE LOW HAS ALLOWED FOR A NICE RIDGE/VALLEY SPLIT
ACROSS THE AREA...WITH MORE SHELTERED VALLEYS HOLDING IN THE LOW AND
MID 20S...WHILE RIDGETOPS ARE IN THE LOW TO MID 30S.
THE MODELS ARE IN GOOD AGREEMENT THROUGH THE SHORT TERM...TAKING THE
LOW PRESSURE SYSTEM EAST ACROSS THE OHIO VALLEY DURING THE DAY...AND
ALLOWING THE ASSOCIATED SURFACE COLD FRONT TO MOVE THROUGH THE AREA
THIS AFTERNOON INTO EARLY THIS EVENING. MEANWHILE...THE MORE NORTHERN
SHORT WAVES WILL CONTINUE TO DROP SOUTHEAST IN SUCCESSION...HELPING
TO ESTABLISH A DEEP TROUGH ACROSS THE EAST BY FRIDAY.
THE CURRENT RADAR SHOWS A BAND OF LIGHT RAIN FROM SOUTH CENTRAL
INDIANA DOWN THROUGH WESTERN KENTUCKY. THE LATEST HRRR SHOWS THIS
ACTIVITY MAKING IT TO OUR DOORSTEP BY DAWN OR SHORTLY THEREAFTER...
ALTHOUGH THERE IS GOOD AGREEMENT THAT THE MAJORITY OF THE MEASURABLE
PRECIPITATION WILL STAY JUST NORTH...WITH MORE SPOTTIER ACTIVITY TO
CONTEND WITH ACROSS OUR AREA THROUGH 14Z. AFTER 14Z...PRECIPITATION
LOOKS TO BLOSSOM AS THE BETTER FORCING ARRIVES. HAVE BEEN CONCERNED
WITH THE COLD VALLEY READINGS ACROSS OUR AREA...HOWEVER IT LOOKS AS
THOUGH THAT BY THE TIME THE BETTER PRECIPITATION DOES MOVE IN...THAT
MOST LOCATIONS WILL BE ABOVE FREEZING. AS SUCH...WILL ISSUE A SPECIAL
WEATHER STATEMENT COVERING THE SPOTTIER PRECIPITATION AT ONSET...AS
MAINLY INTERIOR LOCATIONS WILL STILL LIKELY BE BELOW FREEZING. WILL
CONTINUE TO MONITOR TRENDS VERY CLOSELY OVER THE NEXT FEW HOURS SINCE
ANY RAMP UP IN THE PRECIPITATION WILL MEAN AN ICY COMMUTE POTENTIALLY.
ONCE THE FIRST BATCH OF PRECIP MOVES THROUGH LATER THIS MORNING INTO
EARLY THIS AFTERNOON...THERE WILL LIKELY BE A LULL IN THE
ACTIVITY...BEFORE THE COLDER AIR ARRIVES ON NORTHWEST WINDS AND THE
TROUGH AXIS MOVES THROUGH TONIGHT. THIS WILL ALLOW FOR SOME LIGHT
SNOW ACROSS THE AREA. SNOW SHOWERS WILL LIKELY LINGER IN THE EAST
THROUGH FRIDAY MORNING...BEFORE TAPERING OFF. ANY LIGHT ACCUMULATIONS
WILL FAVOR THE HIGHER TERRAIN IN THE FAR SOUTHEAST.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 446 AM EST THU JAN 29 2015
HIGH PRESSURE WILL TAKE HOLD OF SENSIBLE WEATHER TO BEGIN THIS
PERIOD. WHILE LOW PRESSURE THAT IS AFFECTING THE REGION TODAY
DEVELOPS INTO ANOTHER STRONG COASTAL LOW ACROSS THE NORTHEAST US.
THIS HIGH PRESSURE COUPLED WITH DECREASING CLOUDS WILL ALLOW FOR
DECOUPLING AND LOWS DROPPING DOWN INTO THE MID TO UPPER TEENS
AREA WIDE. THIS HIGH PRESSURE WILL ALLOW MOSTLY SUNNY SKIES EARLY IN
THE DAY FOR YOUR SATURDAY WITH INCREASING CLOUDS IN THE AFTERNOON.
WINDS WILL ALSO BECOME MORE SOUTHWEST BRINGING HIGHS ON SATURDAY INTO
THE UPPER 30S TO LOWER 40S.
NOW THE BIGGER CONCERN CONTINUES TO BE LATE WEEKEND STORM AND
CONFIDENCE REMAINS LOW IN REGARDS TO THIS SYSTEM. THE SETUP IS WE
HAVE A DEVELOPING UPPER LEVEL CLOSED LOW ACROSS THE NORTHERN BAJA
PENINSULA AND ASSOCIATED DEVELOPING SURFACE LOW SATURDAY MORNING.
MEANWHILE A UPPER LEVEL WAVE RIDES OVER RIDGING ACROSS THE NORTHWEST
US. THEN THIS IS WHERE THE MODELS CONTINUE TO STRUGGLE IS IN THE
PHASING PROCESS THAT OCCURS SATURDAY NIGHT IN THE UPPER LEVELS.
EARLIER THE 18Z/28 GFS AND 12Z/28 ECMWF HAD A MORE OPEN WAVE WHICH
TRANSLATED TO A WEAKER SURFACE LOW. THIS WAS NEW BASED ON THE
PREVIOUS RUNS SEEN OVER THE PAST COUPLE OF DAYS. THE LATEST 00Z/29
RUN OF THE GFS DEVELOPS A STRONGER LOW WITH A BIT OF A DEEPER TROUGH
SETTING UP. THE 00Z/29 ECMWF DOES HAVE SIMILARITIES...HOWEVER THE
SURFACE LOW PRESSURE IS NOT AS DEEP. ONE THING THAT REMAINS WITH BOTH
MODELS 00Z RUNS IS BOTH HAVE A GOOD AMT OF QPF RESPECTIVELY. ANOTHER
QUESTION THAT REMAINS IS HOW MUCH COLD AIR STAYS IN PLACE WITH THIS
SYSTEM ON SUNDAY AND THIS WILL DEPEND HEAVILY ON THE EVENTUAL TRACK
OF THIS SURFACE LOW. THAT SAID HAVE LEANED TOWARD A BIT COLDER
THROUGH THE DAY ON SUNDAY. THINKING STILL MUCH OF SUNDAY WOULD LEAD
TO MIXING ACROSS MUCH OF THE CWA WITH MORE IN THE WAY OF SNOW ACROSS
THE BLUEGRASS WHERE TEMPS REMAIN COOLER...HOWEVER CONFIDENCE IN THIS
SYSTEM REMAINS LOW GIVEN THE DRASTIC RUN TO RUN CHANGES SEEN IN THE
DETERMINISTIC MODELS. ALSO KEEPING IN MIND THAT THE ENSEMBLE MEAN HAS
BEEN QUITE ERRATIC AND GIVEN THAT THE 12 PERTURBATIONS IN OUR SYSTEM
ARE ERRATIC EXPLAINS THE LACK OF CONTINUITY. ALL THIS SAID STILL
THINK THERE IS A REASONABLE SHOT OF MEASURABLE SNOW SUNDAY INTO
MONDAY. ANOTHER PIECE TO THE PUZZLE TO KEEP IN MIND IS THAT A MORE
NORTHERLY TRACK SHOWN IN EARLIER RUNS COULD ALLOW FOR MORE SOUTHERLY
FLOW AND WARMER AIR AND LEAD TO LESSENING SNOWFALL TOTALS. ALTHOUGH
BEHIND THIS SYSTEM EXPECT COLD AIR TO FILTER INTO ALL OF THE CWA
SUNDAY NIGHT INTO MONDAY. ALSO WOULD EXPECT GENERALLY FALLING
TEMPERATURES DURING THE DAY ON MONDAY.
AFTER THIS THE AFOREMENTIONED LOW PRESSURE IS THEN FORECAST TO TRACK NE
AND CONTINUE TO DEEPEN ALONG NE ATLANTIC COAST. HIGH PRESSURE WILL
BUILD EAST MONDAY NIGHT AND EXPECT ANOTHER COLD NIGHT WITH GENERALLY
LOW TO MID TEENS ACROSS THE REGION. THESE TEMPS MAY HAVE TO BE
ADJUSTED FURTHER DEPENDING UPON IF WE RECEIVE MEASURABLE SNOW. THIS
HIGH PRESSURE WILL ADVANCE EAST OF THE REGION MOVING INTO THE DAY ON
TUESDAY BRINGING RETURN FLOW AND WELCOMING REBOUND IN
TEMPERATURE...WITH HIGHS IN THE MID TO UPPER 30S. THAT SAID WEDNESDAY
REMAINS UNCERTAIN WITH YET ANOTHER SYSTEM DEVELOPING AND AT THIS POINT
STUCK CLOSE TO THE BLEND. DID INTRODUCE MAINLY SLIGHT POPS DURING
THAT PORTION OF THE PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 219 AM EST THU JAN 29 2015
A PASSING COLD FRONT WILL BRING LOWERING CEILINGS...PRECIPITATION...
AND GUSTY SOUTH TO SOUTHWEST WINDS TO THE AREA THROUGH THURSDAY
EVENING. A STRONG LOW LEVEL JET DEVELOPING DURING THE OVERNIGHT HOURS
WILL ALSO ALLOW FOR LOW LEVEL WIND SHEAR BETWEEN 08 AND 14Z ACROSS
THE AREA. VFR CONDITIONS WILL LIKELY HOLD ON THROUGH THE EARLY
AFTERNOON...BEFORE CELINGS LIKELY COME DOWN QUICKLY TO MVFR/IFR ONCE
THE FRONT MOVES THROUGH THE AREA LATER THIS AFTERNOON INTO EARLY THIS
EVENING.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GEOGERIAN
LONG TERM...DJ
AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION
NWS JACKSON KY
400 AM EST THU JAN 29 2015
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 400 AM EST THU JAN 29 2015
LATEST SURFACE MAP FEATURES HIGH PRESSURE ALONG THE EASTERN
CONUS...WITH LOW PRESSURE MOVING INTO THE GREAT LAKES AND OHIO VALLEY
REGIONS. ALOFT...A SHORT WAVE TROUGH IS ROTATING TOWARDS THE OHIO
VALLEY...WITH ANOTHER TROUGH DROPPING SOUTHEAST INTO THE NORTHERN
PLAINS...AND YET ONE MORE MOVING IN ACROSS SOUTH CENTRAL CANADA.
MAINLY MID AND HIGH LEVEL CLOUDS HAVE BEEN STREAMING IN ACROSS
EASTERN KENTUCKY. THE SOUTHERLY WIND FLOW OUT AHEAD OF THE
APPROACHING SURFACE LOW HAS ALLOWED FOR A NICE RIDGE/VALLEY SPLIT
ACROSS THE AREA...WITH MORE SHELTERED VALLEYS HOLDING IN THE LOW AND
MID 20S...WHILE RIDGETOPS ARE IN THE LOW TO MID 30S.
THE MODELS ARE IN GOOD AGREEMENT THROUGH THE SHORT TERM...TAKING THE
LOW PRESSURE SYSTEM EAST ACROSS THE OHIO VALLEY DURING THE DAY...AND
ALLOWING THE ASSOCIATED SURFACE COLD FRONT TO MOVE THROUGH THE AREA
THIS AFTERNOON INTO EARLY THIS EVENING. MEANWHILE...THE MORE NORTHERN
SHORT WAVES WILL CONTINUE TO DROP SOUTHEAST IN SUCCESSION...HELPING
TO ESTABLISH A DEEP TROUGH ACROSS THE EAST BY FRIDAY.
THE CURRENT RADAR SHOWS A BAND OF LIGHT RAIN FROM SOUTH CENTRAL
INDIANA DOWN THROUGH WESTERN KENTUCKY. THE LATEST HRRR SHOWS THIS
ACTIVITY MAKING IT TO OUR DOORSTEP BY DAWN OR SHORTLY THEREAFTER...
ALTHOUGH THERE IS GOOD AGREEMENT THAT THE MAJORITY OF THE MEASURABLE
PRECIPITATION WILL STAY JUST NORTH...WITH MORE SPOTTIER ACTIVITY TO
CONTEND WITH ACROSS OUR AREA THROUGH 14Z. AFTER 14Z...PRECIPITATION
LOOKS TO BLOSSOM AS THE BETTER FORCING ARRIVES. HAVE BEEN CONCERNED
WITH THE COLD VALLEY READINGS ACROSS OUR AREA...HOWEVER IT LOOKS AS
THOUGH THAT BY THE TIME THE BETTER PRECIPITATION DOES MOVE IN...THAT
MOST LOCATIONS WILL BE ABOVE FREEZING. AS SUCH...WILL ISSUE A SPECIAL
WEATHER STATEMENT COVERING THE SPOTTIER PRECIPITATION AT ONSET...AS
MAINLY INTERIOR LOCATIONS WILL STILL LIKELY BE BELOW FREEZING. WILL
CONTINUE TO MONITOR TRENDS VERY CLOSELY OVER THE NEXT FEW HOURS SINCE
ANY RAMP UP IN THE PRECIPTATION WILL MEAN AN ICY COMMUTE POTENTIALLY.
ONCE THE FIRST BATCH OF PRECIP MOVES THROUGH LATER THIS MORNING INTO
EARLY THIS AFTERNOON...THERE WILL LIKELY BE A LULL IN THE
ACTIVITY...BEFORE THE COLDER AIR ARRIVES ON NORTHWEST WINDS AND THE
TROUGH AXIS MOVES THROUGH TONIGHT. THIS WILL ALLOW FOR SOME LIGHT
SNOW ACROSS THE AREA. SNOW SHOWERS WILL LIKELY LINGER IN THE EAST
THROUGH FRIDAY MORNING...BEFORE TAPERING OFF. ANY LIGHT ACCUMULATIONS
WILL FAVOR THE HIGHER TERRAIN IN THE FAR SOUTHEAST.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 415 PM EST WED JAN 28 2015
QUITE AN ACTIVE PATTERN IN THE EXTENDED PERIOD WITH QUICK MOVING
S/WV TROUGHS OVER THE EASTERN US. THIS PERIOD BEGINS WITH YET
ANOTHER COASTAL LOW MOVING UP THE NEW ENGLAND COASTLINE... WITH
QUIET WEATHER ON THE HOMEFRONT. HIGH PRESSURE SETTLES INTO THE
REGION ON FRIDAY NIGHT INTO SATURDAY WITH RETURN FLOW FROM THE GULF
USHERING IN ADDITIONAL MOISTURE AHEAD OF THE NEXT SYSTEM.
THE END OF THE WEEKEND FEATURES A SYSTEM THAT STILL HAS A LOT OF
UNCERTAINTY TIED TO IT. THE BIG QUESTION IS HOW QUICKLY THE NORTHERN
AND SOUTHERN STREAM ENERGY PHASES TOGETHER...IF AT ALL... THE 12Z/28
GFS SHOWS A MORE LACKLUSTER SOLUTION WITH A WEAKER TROUGH WHEREAS
THE 00Z/28 ECMWF SHOWS THE ENERGY PHASING IN THE MIDWEST AND FORMING
A WELL-DEFINED LOW PRESSURE SYSTEM LIFTING UP ALONG THE NEW ENGLAND
COAST. BOTH SOLUTIONS INDICATE A RAIN TO SNOW CHANGEOVER EVENT FOR
EASTERN KENTUCKY SUNDAY NIGHT INTO MONDAY BUT THE ECMWF SOLUTION HAS
QUITE A BIT MORE ORGANIZED QPF ASSOCIATED WITH IT. AS OF RIGHT
NOW... THE MAJORITY OF THE PRECIP SHOULD FALL AS RAIN ON SUNDAY WHEN
THERE IS BETTER MOISTURE AND LIFT. THOUGH... GIVEN ALL OF THE
UNCERTAINTY... STILL THINK THERE IS POTENTIAL FOR ACCUMULATING SNOW
EARLY MONDAY MORNING SO THIS WILL HAVE TO BE MONITORED AND FINE
TUNED IN SUBSEQUENT FORECAST UPDATES.
TEMPERATURES ON MONDAY ARE EXPECTED TO GENERALLY DROP DURING THE DAY
AS COLD AIR CONTINUES TO PUSH IN BEHIND THE EXITING SYSTEM. HOW
QUICKLY THE SYSTEM EXITS WILL DETERMINE HOW MUCH AND HOW QUICKLY THE
TEMPERATURES WILL DROP. THAT BEING SAID... IT DOES APPEAR THAT WELL
BELOW NORMAL TEMPS WILL SETTLE INTO THE REGION WITH LOWS MONDAY
NIGHT DIPPING INTO THE MID AND UPPER TEENS. HIGH PRESSURE AND
SOUTHERLY FLOW RETURN TUESDAY HELPING TEMPERATURES RECOVER INTO
LOWER 30S. BY WEDNESDAY NIGHT ANOTHER SYSTEM LOOKS TO BRING ANOTHER
CHANCE FOR A MIXED PRECIP EVENT INTO THE DAY ON THURSDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 219 AM EST THU JAN 29 2015
A PASSING COLD FRONT WILL BRING LOWERING CEILINGS...PRECIPITATION...
AND GUSTY SOUTH TO SOUTHWEST WINDS TO THE AREA THROUGH THURSDAY
EVENING. A STRONG LOW LEVEL JET DEVELOPING DURING THE OVERNIGHT HOURS
WILL ALSO ALLOW FOR LOW LEVEL WIND SHEAR BETWEEN 08 AND 14Z ACROSS
THE AREA. VFR CONDITIONS WILL LIKELY HOLD ON THROUGH THE EARLY
AFTERNOON...BEFORE CELINGS LIKELY COME DOWN QUICKLY TO MVFR/IFR ONCE
THE FRONT MOVES THROUGH THE AREA LATER THIS AFTERNOON INTO EARLY THIS
EVENING.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GEOGERIAN
LONG TERM...JVM
AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1203 AM CST THU JAN 29 2015
.UPDATE...
WENT AHEAD AND ISSUED A DENSE FOG ADVISORY FOR LOWER SE TX AND
FAR SW LA. VSBYS AT SE TX AIRPORTS HAVE ALREADY LOWERED TO ONE
QUARTER OF A MILE AND THESE CONDITIONS ARE EXPECTED TO PERSIST
THROUGH THE NIGHT. FOG HAS ALSO DEVELOPED ACRS SW LA...WITH VSBYS
CURRENTLY FLUCTUATING BUT EXPECTED TO LOWER TO AROUND 1/4 MILE AS
THE NIGHT PROGRESSES. CONDITIONS ARE EXPECTED TO IMPROVE BY MID-
MORNING THURSDAY. 24
&&
.PREV DISCUSSION... /ISSUED 1130 PM CST WED JAN 28 2015/
DISCUSSION...
FOR THE 29/06Z TAF ISSUANCE.
AVIATION...
SURFACE RIDGE IS EAST OF THE REGION WITH LIGHT SOUTHERLY WINDS
HELPING TO BRING SOME SHALLOW MOISTURE BACK INTO THE REGION. SHORT
WAVE PRODUCING SOME HIGH LEVEL CLOUDS HAVE PUSHED OFF TO THE EAST
ALSO LEAVING BEHIND CLEAR SKIES. WITH THE CLEAR SKIES AND LIGHT
WINDS...AIR TEMPERATURES SHOULD COOL TO DEW POINTS WITH SOME FOG
FORMATION...ESPECIALLY OVER SOUTHEAST TEXAS AND SOUTHWEST
LOUISIANA WHERE AIR TEMPERATURES HAVE ALREADY COOLED BELOW WHAT
THE EVENING DEW POINTS WERE...AND WITH THAT...VISIBILITY DOWN TO
LIFR AT KBPT AND BOUNCING BETWEEN MVFR/IFR AT KLCH. EXPECT KBPT TO
EXPERIENCE LIFR CONDITIONS FOR THE OVERNIGHT INTO EARLY THURSDAY
MORNING...WITH KLCH ALSO SETTLING IN FOR MAINLY LIFR CONDITIONS
AFTER 29/09Z. THE OTHER TAF SITES THAT HAVE SEEN LESS RETURN FLOW
MOISTURE WILL LIKELY EXPERIENCE MVFR CONDITIONS OVERNIGHT...WITH
THE BRIEF POSSIBILITY OF IFR. WITH INCREASING WINDS AND DAYTIME
HEATING...ANY FOG SHOULD LIFT BY 29/15Z...WITH VFR CONDITIONS
PREVAILING FOR THE REMAINDER OF THE DAY. A WEAK COLD FRONT WILL
MOVE THROUGH AT THE END OF THE TAF PERIOD WITH A SWITCH TO
NORTHWEST WINDS AND CLOUD DECK AROUND 5K FEET MOVING WITH THE
FRONT.
RUA
PREV DISCUSSION... /ISSUED 950 PM CST WED JAN 28 2015/
DISCUSSION...
A QUIET NIGHT UNDERWAY WITH HIGH PRES EAST OF THE
REGION...ALLOWING SELY WINDS TO BRING INCREASING LOW LVL MOISTURE
OVER THE AREA. DEWPOINTS ACRS SW LA AND SE TX ARE IN THE LOWER
50S WITH MIDDLE AND UPPER 40S ACRS ERN PORTIONS OF THE AREA.
OVERNIGHT LOWS ARE EXPECTED TO RUN ABOUT 5-10 DEGREES WARMER THAN
LAST NIGHT WITH LOWS IN THE LOWER TO MIDDLE 50S ACRS ALL BUT THE
ERN-MOST ZONES WHERE TEMPERATURES WILL BE IN THE UPPER 40S/NR 50.
WITH LT WINDS ACRS THE AREA AND DEWPOINT DEPRESSIONS
NARROWING...FOG SHOULD BEGIN DEVELOPING BY MIDNIGHT. FOG IS
EXPECTED TO BEGIN DEVELOPING ACRS LOWER SE TX/SW LA INITIALLY...THEN
INCREASE IN COVERAGE FURTHER NORTH AND EAST ACRS THE AREA THROUGH
THE NIGHT. SREF PROBABILITIES AS WELL AS NAM AND HRRR GUIDANCE
INDICATE THE POTENTIAL FOR VISIBILITIES LESS THAN ONE MILE...AND
DENSE FOG COULD BE POSSIBLE IN A FEW LOCATIONS. WILL CONTINUE TO
MONITOR TRENDS FOR THE POSSIBILITY OF A DENSE FOG ADVISORY.
&&
.PRELIMINARY POINT TEMPS/POPS...
KLCH 52 72 47 59 / 0 0 10 10
KBPT 55 72 50 61 / 0 10 10 10
KAEX 51 72 43 58 / 0 0 10 0
KLFT 50 74 48 60 / 0 0 10 10
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...DENSE FOG ADVISORY UNTIL 8 AM CST THURSDAY FOR CALCASIEU-WEST
CAMERON.
TX...DENSE FOG ADVISORY UNTIL 8 AM CST THURSDAY FOR HARDIN-JEFFERSON-
ORANGE-SOUTHERN JASPER-SOUTHERN NEWTON.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1130 PM CST WED JAN 28 2015
.DISCUSSION...
FOR THE 29/06Z TAF ISSUANCE.
&&
.AVIATION...
SURFACE RIDGE IS EAST OF THE REGION WITH LIGHT SOUTHERLY WINDS
HELPING TO BRING SOME SHALLOW MOISTURE BACK INTO THE REGION. SHORT
WAVE PRODUCING SOME HIGH LEVEL CLOUDS HAVE PUSHED OFF TO THE EAST
ALSO LEAVING BEHIND CLEAR SKIES. WITH THE CLEAR SKIES AND LIGHT
WINDS...AIR TEMPERATURES SHOULD COOL TO DEW POINTS WITH SOME FOG
FORMATION...ESPECIALLY OVER SOUTHEAST TEXAS AND SOUTHWEST
LOUISIANA WHERE AIR TEMPERATURES HAVE ALREADY COOLED BELOW WHAT
THE EVENING DEW POINTS WERE...AND WITH THAT...VISIBILITY DOWN TO
LIFR AT KBPT AND BOUNCING BETWEEN MVFR/IFR AT KLCH. EXPECT KBPT TO
EXPERIENCE LIFR CONDITIONS FOR THE OVERNIGHT INTO EARLY THURSDAY
MORNING...WITH KLCH ALSO SETTLING IN FOR MAINLY LIFR CONDITIONS
AFTER 29/09Z. THE OTHER TAF SITES THAT HAVE SEEN LESS RETURN FLOW
MOISTURE WILL LIKELY EXPERIENCE MVFR CONDITIONS OVERNIGHT...WITH
THE BRIEF POSSIBILITY OF IFR. WITH INCREASING WINDS AND DAYTIME
HEATING...ANY FOG SHOULD LIFT BY 29/15Z...WITH VFR CONDITIONS
PREVAILING FOR THE REMAINDER OF THE DAY. A WEAK COLD FRONT WILL
MOVE THROUGH AT THE END OF THE TAF PERIOD WITH A SWITCH TO
NORTHWEST WINDS AND CLOUD DECK AROUND 5K FEET MOVING WITH THE
FRONT.
RUA
&&
.PREV DISCUSSION... /ISSUED 950 PM CST WED JAN 28 2015/
DISCUSSION...
A QUIET NIGHT UNDERWAY WITH HIGH PRES EAST OF THE
REGION...ALLOWING SELY WINDS TO BRING INCREASING LOW LVL MOISTURE
OVER THE AREA. DEWPOINTS ACRS SW LA AND SE TX ARE IN THE LOWER
50S WITH MIDDLE AND UPPER 40S ACRS ERN PORTIONS OF THE AREA.
OVERNIGHT LOWS ARE EXPECTED TO RUN ABOUT 5-10 DEGREES WARMER THAN
LAST NIGHT WITH LOWS IN THE LOWER TO MIDDLE 50S ACRS ALL BUT THE
ERN-MOST ZONES WHERE TEMPERATURES WILL BE IN THE UPPER 40S/NR 50.
WITH LT WINDS ACRS THE AREA AND DEWPOINT DEPRESSIONS
NARROWING...FOG SHOULD BEGIN DEVELOPING BY MIDNIGHT. FOG IS
EXPECTED TO BEGIN DEVELOPING ACRS LOWER SE TX/SW LA INITIALLY...THEN
INCREASE IN COVERAGE FURTHER NORTH AND EAST ACRS THE AREA THROUGH
THE NIGHT. SREF PROBABILITIES AS WELL AS NAM AND HRRR GUIDANCE
INDICATE THE POTENTIAL FOR VISIBILITIES LESS THAN ONE MILE...AND
DENSE FOG COULD BE POSSIBLE IN A FEW LOCATIONS. WILL CONTINUE TO
MONITOR TRENDS FOR THE POSSIBILITY OF A DENSE FOG ADVISORY.
&&
.PRELIMINARY POINT TEMPS/POPS...
KLCH 53 71 45 59 42 / 0 10 10 10 10
KBPT 55 72 47 59 43 / 0 10 10 10 10
KAEX 51 72 43 56 38 / 0 0 10 0 10
KLFT 50 74 46 58 42 / 0 0 10 10 0
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
938 PM EST FRI JAN 30 2015
.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN THROUGH SATURDAY. LOW PRESSURE WILL
BRING WINTRY WEATHER SUNDAY INTO MONDAY.
&&
.NEAR TERM /THROUGH SATURDAY/...
THE FAA TERMINAL DOPPLER RADAR INDICATES ONLY A COUPLE OF
MICROSCALE SNOW BANDS REMAIN...ONE OVER MOSTLY WASHINGTON
COUNTY...AND ANOTHER MUCH WEAKER ONE OVER SOUTHWESTERN ALLEGHENY
COUNTY. MODEL SOUNDINGS FROM BOTH THE RAP AND HRRR SHOW A SCENARIO
WHEREBY INVERSION HEIGHTS ARE FALLING SIMULTANEOUSLY WITH BOUNDARY
LAYER MOISTURE DEPTH DECREASING AS WELL. LIKEWISE...UPSTREAM
ACTIVITY OFF OF LAKE HURON IS QUICKLY FALLING APART...AND THE
TREND TOWARD ANY ADDITIONAL INPUT FROM THE SLIVER OF LAKE ERIE
THAT IS OPEN WILL NOT BE PARTICULARLY HELPFUL TO REGENERATION OF
ANY OF THE BANDS. THAT SAID...ACTIVITY WILL LIKELY TAKE A FEW
HOURS TO WANE WITH THE UPSLOPE AREAS TAKING THE LONGEST TO FULLY
HALT THEIR SNOW SHOWER AND FLURRY ACTION.
NORTHWESTERLY FLOW CONTINUES THROUGH MUCH OF THE EVENING HOURS
BEFORE SLOWLY TURNING WEST OVERNIGHT AS A SURFACE HIGH BUILDS
GENERALLY JUST TO THE SOUTH OF THE REGION. WITH AT THE VERY LEAST
PARTIAL CLEARING...IF NOT FULL CLEARING AT TIMES...TEMPERATURES
SHOULD DROP RAPIDLY WITH NEW SNOW COVER. THIS COMBINED WITH
DECREASING YET STILL BRISK SURFACE FLOW WILL ALLOW FOR WIND CHILL
ADVISORY CRITERIA WIND CHILL INDEX VALUES BY MORNING OVER THE HIGHER
TERRAIN AND NORTHEASTERN CWA. THIS IS IN LINE WITH CURRENT
HEADLINES...AND NO ADDITIONAL EXPANSION OF THESE HEADLINES ARE
ANTICIPATED AT THIS TIME. HOWEVER...WITH RAPID CLEARING AND NEW
SNOW ON THE GROUND...ALL AREAS WILL LIKELY BE VERY COLD BY
MORNING...WITH MANY PORTIONS OF THE CWA CHALLENGING OR EVEN
DROPPING BELOW ZERO BY THAT JUNCTURE.
SOME WARMER AIR DOES START TO FLOW NORTHWARD ON SATURDAY AS THE
SURFACE HIGH AXIS MOVES TO THE EAST OF THE AREA AND SOUTHWESTERLY
FLOW PREVAILS FOR A TIME. EXPECTATIONS SHOULD BE
MUTED...THOUGH...AS SUCH A COLD START AND WEAK VERTICAL MIXING
WILL LIKELY KEEP MOST OF THE AREA IN THE 20S. FRIES
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
HIGH PRES SHOULD CONT DRY WEA INTO SAT EVE. A DIGGING UPR TROF IS
PROGGED TO ADVN OUT OF THE PLAINS AND TRACK ACRS THE GT LKS AND
OH VLY RGN SUN INTO MON. ASSOCIATED SFC LOW PRES IS PROGGED TO
DEEPEN AS IT MOVES ACRS THE TN AND OH VLY RGNS ALSO. THIS WL
SPREAD SNW INTO THE RGN LT SAT NGT THRU MON MRNG WITH DEEP
AVAILABLE MSTR AND OMEGA.
WITH A CLOSED 850MB LOW...A MORE PROLONGED PCPN EVENT IS EXPD AS
OPPOSED TO THE OPEN SYSTEM EARLIER IN THE WK. WITH ENOUGH
POTENTIAL FOR HEAVY SNW OR A SNW/ICE MIX...ISSUED A WINTER STORM
WATCH FOR MUCH OF THE AREA. LEFT AREAS GENLY S OF I 70 OUT OF THE
WATCH...EXCEPT FOR THE WV/MD RIDGES...AS ENOUGH WRM AIR IS EXPD TO
WRAP IN AHD OF THE LOW TO ALLOW FOR A RAIN/SNW MIX OR EVEN A PD OF
ALL RAIN. AREAS BETWEEN I 70- AND I 80 COULD SEE ENOUGH WRM AIR
ALOFT FOR FRZG RAIN TO MIX IN AT TIMES AS WELL. GENLY FOLLOWED A
SREF/GFS/ECMWF MDL BLEND TO WORK OUT THE DETAILS...AND USED
CRITICAL THICKNESSES/MDL SOUNDING PROFILES FOR PCPN TYPE. BEST
POTENTIAL FOR GREATER THAN 6 INCHES OF SNW EXISTS N OF PIT BASED
ON LATEST MDL GUIDANCE...THOUGH THIS WL BE REFINED OVR THE NXT
COUPLE OF DAYS.
SNW SHOULD CONT MON UNTIL THE UPR TROF AXIS SHIFTS E IN THE AFTN.
NUDGED TEMPS TO THE LATEST COLDER THAN SEASONAL AVG SREF GUIDANCE.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
A COLD...WINTER PATTERN WILL CONTINUE FOR THE REST OF THE LONG
TERM. THE NEXT BEST CHANCE FOR SNOW SHOWERS WILL ARRIVE LATE IN
THE PERIOD.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
LINGERING MVFR STRATOCUMULUS AND SNOW SHOWERS CONTINUE TO PLAGUE
SEVERAL OF THE TAF SITES EARLY TONIGHT. THIS IS IN PART DUE TO
WHAT LOOKS TO BE AN UPSTREAM CONNECTION WITH MOISTURE FROM LAKE
HURON. SUBSIDENCE FROM THE BUILDING RIDGE AND A WESTERLY WIND
SHIFT WILL HELP TO DIMINISH THE CLOUD COVER AND IMPROVE CONDITIONS OVER
NEXT FEW HOURS...WITH THE HRRR AND RUC SUGGESTING VFR CONDITIONS
BY 03Z. IN ADDITION...WINDS WILL WEAKEN WITH THE BUILDING HIGH
PRESSURE....WITH NEARLY CALM WIND ANTICIPATED OVERNIGHT. VFR
CONDITIONS WILL REMAIN THROUGH THE REST OF THE TAF PERIOD...WITH
HIGH CLOUDS AND SOME DIURNAL CU DEVELOPING SATURDAY AFTERNOON
AHEAD OF THE SYSTEM PROGGED FOR SUNDAY.
.OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/...
WIDESPREAD RESTRICTIONS CAN BE EXPECTED SUNDAY AND MONDAY AS A LOW
PRESSURE SYSTEM CROSSES THE REGION.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WINTER STORM WATCH FROM LATE SATURDAY NIGHT THROUGH MONDAY
MORNING FOR MDZ001.
WIND CHILL ADVISORY UNTIL 10 AM EST SATURDAY FOR MDZ001.
OH...WINTER STORM WATCH FROM LATE SATURDAY NIGHT THROUGH MONDAY
MORNING FOR OHZ039>041-048>050-057>059.
PA...WINTER STORM WATCH FROM LATE SATURDAY NIGHT THROUGH MONDAY
MORNING FOR PAZ007>009-013>016-020>023-029-073>076.
WIND CHILL ADVISORY UNTIL 10 AM EST SATURDAY FOR PAZ008-009-
015-016-023-074-076.
WV...WINTER STORM WATCH FROM LATE SATURDAY NIGHT THROUGH MONDAY
MORNING FOR WVZ001>003-023-041.
WIND CHILL ADVISORY UNTIL 10 AM EST SATURDAY FOR WVZ023-041.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
820 PM EST FRI JAN 30 2015
.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN THROUGH SATURDAY. LOW PRESSURE WILL
BRING WINTRY WEATHER SUNDAY INTO MONDAY.
&&
.NEAR TERM /THROUGH SATURDAY/...
THE REGIONAL RADAR MOSAIC INDICATES SNOW SHOWER ACTIVITY...WHILE
STILL FAIRLY PERVASIVE...IS DEFINITELY IN A DOWNWARD TREND ACROSS
THE CWA THIS EVENING. MODEL SOUNDINGS FROM BOTH THE RAP AND HRRR
SHOW A SCENARIO WHEREBY INVERSION HEIGHTS ARE FALLING
SIMULTANEOUSLY WITH BOUNDARY LAYER MOISTURE DEPTH DECREASING AS
WELL. LIKEWISE...UPSTREAM ACTIVITY OFF OF LAKE HURON IS QUICKLY
FALLING APART...AND THE TREND TOWARD ANY ADDITIONAL INPUT FROM THE
SLIVER OF LAKE ERIE THAT IS OPEN WILL NOT BE PARTICULARLY HELPFUL
TO REGENERATION OF ANY OF THE BANDS. THAT SAID...ACTIVITY WILL
LIKELY TAKE A FEW HOURS TO WANE WITH THE UPSLOPE AREAS TAKING THE
LONGEST TO FULLY HALT THEIR SNOW SHOWER AND FLURRY ACTION.
HOWEVER...GIVEN THE DOWNWARD TREND IN ACTIVITY AND MINIMAL
ACCUMULATION EXPECTATIONS THE REST OF THE EVENING...WINTER WEATHER
ADVISORIES FOR THE HIGHER TERRAIN HAVE BEEN ALLOWED TO EXPIRE AS
SCHEDULED AT 7 PM.
NORTHWESTERLY FLOW CONTINUES THROUGH MUCH OF THE EVENING HOURS
BEFORE SLOWLY TURNING WEST OVERNIGHT AS A SURFACE HIGH BUILDS
GENERALLY JUST TO THE SOUTH OF THE REGION. WITH AT THE VERY LEAST
PARTIAL CLEARING...IF NOT FULL CLEARING AT TIMES...TEMPERATURES
SHOULD DROP RAPIDLY WITH NEW SNOW COVER. THIS COMBINED WITH
DECREASING YET STILL BRISK SURFACE FLOW WILL ALLOW FOR WIND CHILL
ADVISORY CRITERIA WIND CHILL INDEX VALUES BY MORNING OVER THE HIGHER
TERRAIN AND NORTHEASTERN CWA. THIS IS IN LINE WITH CURRENT
HEADLINES...AND NO ADDITIONAL EXPANSION OF THESE HEADLINES ARE
ANTICIPATED AT THIS TIME. HOWEVER...WITH RAPID CLEARING AND NEW
SNOW ON THE GROUND...ALL AREA WILL LIKELY BE VERY COLD BY
MORNING...WITH MANY PORTIONS OF THE CWA CHALLENGING ZERO BY THAT
JUNCTURE.
SOME WARMER AIR DOES START TO FLOW NORTHWARD ON SATURDAY AS THE
SURFACE HIGH AXIS MOVES TO THE EAST OF THE AREA AND SOUTHWESTERLY
FLOW PREVAILS FOR A TIME. EXPECTATIONS SHOULD BE
MUTED...THOUGH...AS SUCH A COLD START AND WEAK VERTICAL MIXING
WILL LIKELY KEEP MOST OF THE AREA IN THE 20S. FRIES
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
HIGH PRES SHOULD CONT DRY WEA INTO SAT EVE. A DIGGING UPR TROF IS
PROGGED TO ADVN OUT OF THE PLAINS AND TRACK ACRS THE GT LKS AND
OH VLY RGN SUN INTO MON. ASSOCIATED SFC LOW PRES IS PROGGED TO
DEEPEN AS IT MOVES ACRS THE TN AND OH VLY RGNS ALSO. THIS WL
SPREAD SNW INTO THE RGN LT SAT NGT THRU MON MRNG WITH DEEP
AVAILABLE MSTR AND OMEGA.
WITH A CLOSED 850MB LOW...A MORE PROLONGED PCPN EVENT IS EXPD AS
OPPOSED TO THE OPEN SYSTEM EARLIER IN THE WK. WITH ENOUGH
POTENTIAL FOR HEAVY SNW OR A SNW/ICE MIX...ISSUED A WINTER STORM
WATCH FOR MUCH OF THE AREA. LEFT AREAS GENLY S OF I 70 OUT OF THE
WATCH...EXCEPT FOR THE WV/MD RIDGES...AS ENOUGH WRM AIR IS EXPD TO
WRAP IN AHD OF THE LOW TO ALLOW FOR A RAIN/SNW MIX OR EVEN A PD OF
ALL RAIN. AREAS BETWEEN I 70- AND I 80 COULD SEE ENOUGH WRM AIR
ALOFT FOR FRZG RAIN TO MIX IN AT TIMES AS WELL. GENLY FOLLOWED A
SREF/GFS/ECMWF MDL BLEND TO WORK OUT THE DETAILS...AND USED
CRITICAL THICKNESSES/MDL SOUNDING PROFILES FOR PCPN TYPE. BEST
POTENTIAL FOR GREATER THAN 6 INCHES OF SNW EXISTS N OF PIT BASED
ON LATEST MDL GUIDANCE...THOUGH THIS WL BE REFINED OVR THE NXT
COUPLE OF DAYS.
SNW SHOULD CONT MON UNTIL THE UPR TROF AXIS SHIFTS E IN THE AFTN.
NUDGED TEMPS TO THE LATEST COLDER THAN SEASONAL AVG SREF GUIDANCE.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
A COLD...WINTER PATTERN WILL CONTINUE FOR THE REST OF THE LONG
TERM. THE NEXT BEST CHANCE FOR SNOW SHOWERS WILL ARRIVE LATE IN
THE PERIOD.
&&
.AVIATION /01Z SATURDAY THROUGH WEDNESDAY/...
LINGERING MVFR STRATOCUMULUS AND SNOW SHOWERS CONTINUE TO PLAGUE
SEVERAL OF THE TAF SITES EARLY TONIGHT. THIS IS IN PART DUE TO
WHAT LOOKS TO BE AN UPSTREAM CONNECTION WITH MOISTURE FROM LAKE
HURON. SUBSIDENCE FROM THE BUILDING RIDGE AND A WESTERLY WIND
SHIFT WILL HELP TO DIMINISH THE CLOUD COVER AND IMPROVE CONDITIONS OVER
NEXT FEW HOURS...WITH THE HRRR AND RUC SUGGESTING VFR CONDITIONS
BY 03Z. IN ADDITION...WINDS WILL WEAKEN WITH THE BUILDING HIGH
PRESSURE....WITH NEARLY CALM WIND ANTICIPATED OVERNIGHT. VFR
CONDITIONS WILL REMAIN THROUGH THE REST OF THE TAF PERIOD...WITH
HIGH CLOUDS AND SOME DIURNAL CU DEVELOPING SATURDAY AFTERNOON
AHEAD OF THE SYSTEM PROGGED FOR SUNDAY.
.OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/...
WIDESPREAD RESTRICTIONS CAN BE EXPECTED SUNDAY AND MONDAY AS A LOW
PRESSURE SYSTEM CROSSES THE REGION.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WINTER STORM WATCH FROM LATE SATURDAY NIGHT THROUGH MONDAY
MORNING FOR MDZ001.
WIND CHILL ADVISORY UNTIL 10 AM EST SATURDAY FOR MDZ001.
OH...WINTER STORM WATCH FROM LATE SATURDAY NIGHT THROUGH MONDAY
MORNING FOR OHZ039>041-048>050-057>059.
PA...WINTER STORM WATCH FROM LATE SATURDAY NIGHT THROUGH MONDAY
MORNING FOR PAZ007>009-013>016-020>023-029-073>076.
WIND CHILL ADVISORY UNTIL 10 AM EST SATURDAY FOR PAZ008-009-
015-016-023-074-076.
WV...WINTER STORM WATCH FROM LATE SATURDAY NIGHT THROUGH MONDAY
MORNING FOR WVZ001>003-023-041.
WIND CHILL ADVISORY UNTIL 10 AM EST SATURDAY FOR WVZ023-041.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
659 PM EST FRI JAN 30 2015
.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN THROUGH SATURDAY. LOW PRESSURE WILL
BRING WINTRY WEATHER SUNDAY INTO MONDAY.
&&
.NEAR TERM /THROUGH SATURDAY/...
THE REGIONAL RADAR MOSAIC INDICATES SNOW SHOWER ACTIVITY...WHILE
STILL FAIRLY PERVASIVE...IS DEFINITELY IN A DOWNWARD TREND ACROSS
THE CWA THIS EVENING. MODEL SOUNDINGS FROM BOTH THE RAP AND HRRR
SHOW A SCENARIO WHEREBY INVERSION HEIGHTS ARE FALLING
SIMULTANEOUSLY WITH BOUNDARY LAYER MOISTURE DEPTH DECREASING AS
WELL. LIKEWISE...UPSTREAM ACTIVITY OFF OF LAKE HURON IS QUICKLY
FALLING APART...AND THE TREND TOWARD ANY ADDITIONAL INPUT FROM THE
SLIVER OF LAKE ERIE THAT IS OPEN WILL NOT BE PARTICULARLY HELPFUL
TO REGENERATION OF ANY OF THE BANDS. THAT SAID...ACTIVITY WILL
LIKELY TAKE A FEW HOURS TO WANE WITH THE UPSLOPE AREAS TAKING THE
LONGEST TO FULLY HALT THEIR SNOW SHOWER AND FLURRY ACTION.
HOWEVER...GIVEN THE DOWNWARD TREND IN ACTIVITY AND MINIMAL
ACCUMULATION EXPECTATIONS THE REST OF THE EVENING...WINTER WEATHER
ADVISORIES FOR THE HIGHER TERRAIN HAVE BEEN ALLOWED TO EXPIRE AS
SCHEDULED AT 7 PM.
NORTHWESTERLY FLOW CONTINUES THROUGH MUCH OF THE EVENING HOURS
BEFORE SLOWLY TURNING WEST OVERNIGHT AS A SURFACE HIGH BUILDS
GENERALLY JUST TO THE SOUTH OF THE REGION. WITH AT THE VERY LEAST
PARTIAL CLEARING...IF NOT FULL CLEARING AT TIMES...TEMPERATURES
SHOULD DROP RAPIDLY WITH NEW SNOW COVER. THIS COMBINED WITH
DECREASING YET STILL BRISK SURFACE FLOW WILL ALLOW FOR WIND CHILL
ADVISORY CRITERIA WIND CHILL INDEX VALUES BY MORNING OVER THE HIGHER
TERRAIN AND NORTHEASTERN CWA. THIS IS IN LINE WITH CURRENT
HEADLINES...AND NO ADDITIONAL EXPANSION OF THESE HEADLINES ARE
ANTICIPATED AT THIS TIME. HOWEVER...WITH RAPID CLEARING AND NEW
SNOW ON THE GROUND...ALL AREA WILL LIKELY BE VERY COLD BY
MORNING...WITH MANY PORTIONS OF THE CWA CHALLENGING ZERO BY THAT
JUNCTURE.
SOME WARMER AIR DOES START TO FLOW NORTHWARD ON SATURDAY AS THE
SURFACE HIGH AXIS MOVES TO THE EAST OF THE AREA AND SOUTHWESTERLY
FLOW PREVAILS FOR A TIME. EXPECTATIONS SHOULD BE
MUTED...THOUGH...AS SUCH A COLD START AND WEAK VERTICAL MIXING
WILL LIKELY KEEP MOST OF THE AREA IN THE 20S. FRIES
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
HIGH PRES SHOULD CONT DRY WEA INTO SAT EVE. A DIGGING UPR TROF IS
PROGGED TO ADVN OUT OF THE PLAINS AND TRACK ACRS THE GT LKS AND
OH VLY RGN SUN INTO MON. ASSOCIATED SFC LOW PRES IS PROGGED TO
DEEPEN AS IT MOVES ACRS THE TN AND OH VLY RGNS ALSO. THIS WL
SPREAD SNW INTO THE RGN LT SAT NGT THRU MON MRNG WITH DEEP
AVAILABLE MSTR AND OMEGA.
WITH A CLOSED 850MB LOW...A MORE PROLONGED PCPN EVENT IS EXPD AS
OPPOSED TO THE OPEN SYSTEM EARLIER IN THE WK. WITH ENOUGH
POTENTIAL FOR HEAVY SNW OR A SNW/ICE MIX...ISSUED A WINTER STORM
WATCH FOR MUCH OF THE AREA. LEFT AREAS GENLY S OF I 70 OUT OF THE
WATCH...EXCEPT FOR THE WV/MD RIDGES...AS ENOUGH WRM AIR IS EXPD TO
WRAP IN AHD OF THE LOW TO ALLOW FOR A RAIN/SNW MIX OR EVEN A PD OF
ALL RAIN. AREAS BETWEEN I 70- AND I 80 COULD SEE ENOUGH WRM AIR
ALOFT FOR FRZG RAIN TO MIX IN AT TIMES AS WELL. GENLY FOLLOWED A
SREF/GFS/ECMWF MDL BLEND TO WORK OUT THE DETAILS...AND USED
CRITICAL THICKNESSES/MDL SOUNDING PROFILES FOR PCPN TYPE. BEST
POTENTIAL FOR GREATER THAN 6 INCHES OF SNW EXISTS N OF PIT BASED
ON LATEST MDL GUIDANCE...THOUGH THIS WL BE REFINED OVR THE NXT
COUPLE OF DAYS.
SNW SHOULD CONT MON UNTIL THE UPR TROF AXIS SHIFTS E IN THE AFTN.
NUDGED TEMPS TO THE LATEST COLDER THAN SEASONAL AVG SREF GUIDANCE.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
A COLD...WINTER PATTERN WILL CONTINUE FOR THE REST OF THE LONG
TERM. THE NEXT BEST CHANCE FOR SNOW SHOWERS WILL ARRIVE LATE IN
THE PERIOD.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
MVFR CIGS WITH IFR VSBY IN SNOW SHWRS WL CONT THIS AFTN. GENL
IMPROVEMENT CAN BE ANTICIPATED THEREAFTER AS DRY ADVCTN AND SBSDNC
INCRS. SFC WIND ARE EXPECTED TO CONTINUE TO GUST FROM THE W AND NW
AT 15 TO 25 KNOTS THROUGH THE DAY. FURTHER IMPROVEMENTS CAN BE
EXPECTED AS HIGH PRES BLDS THROUGH SATURDAY MRNG.
.OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/...
WIDESPREAD RESTRICTIONS CAN BE EXPECTED WITH SUNDAY LOW PRES AND
WITH A MONDAY CDFNT.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WINTER STORM WATCH FROM LATE SATURDAY NIGHT THROUGH MONDAY
MORNING FOR MDZ001.
WIND CHILL ADVISORY UNTIL 10 AM EST SATURDAY FOR MDZ001.
OH...WINTER STORM WATCH FROM LATE SATURDAY NIGHT THROUGH MONDAY
MORNING FOR OHZ039>041-048>050-057>059.
PA...WINTER STORM WATCH FROM LATE SATURDAY NIGHT THROUGH MONDAY
MORNING FOR PAZ007>009-013>016-020>023-029-073>076.
WIND CHILL ADVISORY UNTIL 10 AM EST SATURDAY FOR PAZ008-009-
015-016-023-074-076.
WV...WINTER STORM WATCH FROM LATE SATURDAY NIGHT THROUGH MONDAY
MORNING FOR WVZ001>003-023-041.
WIND CHILL ADVISORY UNTIL 10 AM EST SATURDAY FOR WVZ023-041.
&&
$$
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
357 PM EST THU JAN 29 2015
.SYNOPSIS...
A COLD FRONT WILL SWING THROUGH THE REGION TONIGHT. HIGH PRESSURE
BUILDING INTO THE REGION WILL BRING WINDY AND COLD CONDITIONS
FRIDAY AND FRIDAY NIGHT. THE HIGH WILL BUILD OVER THE AREA
SATURDAY...BUT LOW PRESSURE MAY IMPACT THE AREA LATER SUNDAY INTO
MONDAY. COLD HIGH PRESSURE WILL RETURN FOR THE MIDDLE PORTION OF
NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
STILL HAVE SEVERAL MESONET OBS SHOWING 31/32 DEG F IN ANNE
ARUNDEL...PRINCE GEORGES COUNTIES. WITH PRECIP COMING IN FROM THE
WEST AND TEMPS NOT LIKELY TO MOVE ANY HIGHER /IN FACT GIVEN
DEWPOINTS THEY COULD DROP A DEGREE OR TWO/...HAVE OPTED TO EXPAND
EXISTING WINTER WEATHER ADVISORY EAST TO THE BAY TO INCLUDE MUCH
OF THE WASHINGTON METRO AREA FOR A BRIEF PERIOD OF SLEET MIXED
WITH POCKETS OF FREEZING RAIN OCCURRING DURING THE EVENING RUSH HOUR.
PREV...
A WINTRY MIX OF FREEZING RAIN...SLEET AND SNOW IS EXPECTED FOR MUCH
OF THE OUTLOOK AREA THIS AFTERNOON AND EARLY EVENING AND THEREFORE A
A WINTER WEATHER ADVISORY IS IN EFFECT.
HIGH PRESSURE CONTINUES TO MOVE OFF THE CAROLINA COAST THIS
AFTERNOON AND SOUTHERLY FLOW HAS INCREASED ACROSS THE REGION. A COLD
FRONT IS DRAPED FROM LAKE ERIE TO OH/IN TO KY. AHEAD OF THE COLD
FRONT AND IN RESPONSE TO A SHORTWAVE TROUGH AND WAA...PRECIPITATION
WILL CONTINUE TO MOVE ACROSS THE APPALACHIAN MTNS AND HIGHLANDS THIS
AFTERNOON. A NOSE OF +3 WARM AIR WILL CONTINUE TO MOVE INTO THE REGION AT
850MB. SOUTHERLY FLOW AT THE SFC HAS ALLOWED TEMPS TO CLIMB BUT COLD
SURFACES FROM RECENT COLD TEMPS AND SNOWPACK HAS SLOWED THEM FROM
CLIMBING MUCH. MANY OBS ARE AOB FREEZING AROUND WASHINGTON DC AND
BALTIMORE AND NORTH AND WEST ARE SUCH THAT. SOUTHERLY FLOW AT THE
SFC HAS MAINLY ALLOWED TEMPS IN VALLEYS IN CENTRAL
FOOTHILLS...PIEDMONT AND SOUTHERN MD TO RISE TO THE MID TO UPPER
30S. THIS TREND WILL CONTINUE AS BOUNDARY LAYER WINDS ARE EXPECTED
TO INCREASE TO 10-15KTS. THIS IS A BORDERLINE EVENT SINCE MANY ROAD
TEMPS ARE ABOVE FREEZING BUT MESONET OBS ARE NOT. EVEN THOUGH ASOS
AND AWOS SITES ARE WELL ABOVE FREEZING...MANY OBS BETWEEN THOSE
SITES ARE NOT. THEREFORE...PRECIPITATION MOVING EASTWARD MAY MELT
AND FREEZE ON CONTACT ESPECIALLY ON UNTREATED SURFACES. FURTHER
NORTH NEAR THE MD/PA BORDER...COLDER TEMPS ALOFT MAY LEAD TO MORE
SLEET AND SNOW THAN FZRA BUT ALL FROZEN PTYPES ARE POSSIBLE TODAY.
THEREFORE A WINTER WEATHER ADVISORY WAS ISSUED FOR THIS AFTERNOON
AND EVENING.
THE HRRR HAS BEEN FOLLOWING THE PRECIPITATION RATHER WELL THIS
MORNING. ANTICIPATE PRECIPITATION TO BE EAST OF THE WESTERN SHORE OF
THE CHESAPEAKE BAY BY 8PM. TEMPS SOUTH OF WASHINGTON DC ARE EXPECTED
TO BE ABOVE FREEZING AND THEREFORE RAIN AND SLEET ARE THE MAIN
PRECIP TYPES IN THIS REGION. THE FRONT WILL FOLLOW BEHIND AND MOVE ACROSS
THE MID-ATLANTIC TONIGHT REACHING THE CHESAPEAKE BAY BY LATE
TONIGHT. NW WINDS WILL MOVE IN BEHIND THE FRONT AND UPSLOPE SNOW
SHOWERS ARE EXPECTED ACROSS THE WESTERN SLOPES OF THE ALLEGHENY
FRONT. SNOW ACCUMULATION IS EXPECTED AS LAPSE RATES STEEPEN IN THE
SNOW GROWTH ZONE. A WINTER WEATHER ADVISORY CONTINUES FOR THE
WESTERN SLOPES FOR ACCUMULATING SNOW INTO FRIDAY. ACCUMULATION OF
4-8 INCHES ARE POSSIBLE IN THESE LOCATIONS.
VORTICITY ADVECTION WILL BE ROTATING AROUND THE MAIN TROUGH
TONIGHT AND TOMORROW. DRY WESTERLY WIND EAST OF THE ALLGHENY FRONT
SHOULD LIMIT PRECIP FROM REACHING THE GROUND. FCST MIN TEMPS WILL
REACH THE 20S IN THE MTNS AND LOW TO MID 30S FROM WASHINGTON DC AND
SOUTH AND EAST ALONG I-95.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
HIGH PRES BLDG INTO THE MID ATLC WL LEAD TO A STRNG PRES GRAD
ACROSS THE AREA. THIS IN TURN WL LEAD TO A WINDY DAY. BUFKIT
X-SXNS ARE SHOWING INXS OF 40 KT A FEW THOUSAND FT OFF THE GRND.
THIS WL HV THE PTNL TO BE BROUGHT TO THE SFC. WE ARE ADVSRTSG THE
PSBLTY OF A WIND ADVSRY - MOST LKLY AREAS WL BE ABV 1500 FT AND
ACROSS THE NRN 1/2 OF THE FCST AREA.
HIGHS IN THE LM30S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
HIGH PRES BLDG OVR THE RNG FRI NGT WL LEAD TO CHILLY TEMPS. LOWS
IN THE TEENS ACROSS MUCH OF THE AREA. WINDS WL BE DIMINISHING
OVRNGT...BUT W/ COLD TEMPS WINDS CHILLS XPCTD TO BE IN THE SINGLE
DIGITS E OF THE MTNS. PRSNTLY SEEING VALUES AS LOW AS -14 IN THE
HIGHLANDS. IF THIS TREND CONTS A WIND CHILL ADVSRY WL BE NEEDED
FOR OUR FAR WRN AREA.
SAT LOOKS TO BE M SUNNY BUT COLD W/ HIGHS RANGING FM THE U20S TO
THE MU30S OVR MOST OF THE AREA.
SAT NGT WL BE COLD...BUT A LTL WARMER THAN FRI NGT. NO WINDS SO
WIND CHILL WL NOT BE A CONCERN.
WHAT HAD BEEN A SPLIT IN THE MODELS BETWEEN A LOW TRACK TO OUR NORTH
AND ANOTHER TRACK TO OUR SOUTH SEEMS TO BE CONSOLIDATING AROUND THE
SOUTHERN TRACK NOW...TAKING IT EAST THRU S VA OR NC. THAT SUPPORTS
SNOW FOR MUCH IF NOT ALL OF OUR REGION. WOULD BE PASSING THRU AT A
GOOD CLIP BUT ACCUMULATING SNOW CERTAINLY A POSSIBILITY FOR SUN
AFTERNOON INTO MONDAY MORNING.
HIGH PRESSURE WILL FOLLOW FOR TUE. NEXT COLD FRONT POISED FOR
WEDNESDAY.
&&
.AVIATION /21Z THURSDAY THROUGH TUESDAY/...
A WINTRY MIX IS EXPECTED THIS AFTERNOON AND EVENING FOR THE
TERMINALS. PRECIP WILL MOVE QUICK AND FROM WEST TO EAST THROUGH THE
REGION TODAY ENDING ACROSS BWI-MTN-DCA BY 8PM. MVFR CONDITIONS
POSSIBLE AT MRB-IAD-DCA-MTN-BWI AS COLDER AIR FURTHER NORTH GIVES A
GREATER POTENTIAL FOR SNPL. FURTHER SOUTH..CHO SHOULD STAY RAPL. S
WINDS 10-15KTS WILL CONTINUE TODAY AND TONIGHT AHEAD OF A COLD
FRONT. A STRONG FROPA IS EXPECTED TONIGHT WITH NW WINDS 20-25KTS G
35-40 EXPECTED LATE TONIGHT AND FRIDAY ACROSS THE TERMINALS.
WINDY CONDS FRI AND FRI NGT AS HIGH PRES BLDS INTO THE AREA. NO
PROBS XPCTD AVIATION-WISE SAT OR SAT NGT.
SNOW AND IFR CONDITIONS ARE POSSIBLE SUNDAY AFTERNOON INTO MONDAY
MORNING AS LOW PRESSURE SLIDES BY TO OUR SOUTH. VFR FOR TUESDAY.
&&
.MARINE...
A WINTRY MIX WILL MOVE ACROSS THE WATERS THIS EVENING. A MIX OF SNOW
SLEET AND RAIN ARE POSSIBLE BUT SHOULD END BY LATE TONIGHT.
SOUTHERLY WINDS WILL CONTINUE ON THE WATERS THROUGH TONIGHT BEFORE A
STRONG FROPA MOVES ACROSS THE WATERS BY FRIDAY MORNING. NW WINDS
20-25KT GUST AROUND 45KTS POSSIBLE. SCA ARE IN EFFECT AND WILL
TRANSITION TO A GALE WARNING FRIDAY.
A GALE WRNG IS IN EFFECT FM FRI MRNG THRU THE ERLY HRS OF SAT
MRNG..AND THEN AN SCA WL LKLY GO INTO EFFECT AFTRWARDS FOR THE
RMNDR OF THE NGT. WINDS WL BE DIMINISHING FOR SAT AND SAT NGT.
GUSTY WINDS AND A SMALL CRAFT ADVISORY ARE POSSIBLE ON MONDAY INTO
MONDAY NIGHT AS LOW PRESSURE INTENSIFIES OFFSHORE.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER WEATHER ADVISORY UNTIL 9 PM EST THIS EVENING FOR DCZ001.
MD...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR MDZ003-
502.
WINTER WEATHER ADVISORY UNTIL 9 PM EST THIS EVENING FOR
MDZ004>006-011-013-014-503>508.
WINTER WEATHER ADVISORY UNTIL NOON EST FRIDAY FOR MDZ501.
VA...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR VAZ027-
028-030-031-504.
WINTER WEATHER ADVISORY UNTIL 9 PM EST THIS EVENING FOR
VAZ052>054-501-505-506.
WINTER WEATHER ADVISORY UNTIL NOON EST FRIDAY FOR VAZ503.
WV...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR
WVZ050>053-055-502-504-506.
WINTER WEATHER ADVISORY UNTIL NOON EST FRIDAY FOR WVZ501-503-
505.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ530>534-
537>543.
GALE WARNING FROM 6 AM FRIDAY TO 1 AM EST SATURDAY FOR
ANZ530>543.
SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ535-
536.
&&
$$
BPP/HAS/WOODY!/CAS
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
252 PM EST THU JAN 29 2015
.SYNOPSIS...
A COLD FRONT WILL SWING THROUGH THE REGION TONIGHT. HIGH PRESSURE
BUILDING INTO THE REGION WILL BRING WINDY AND COLD CONDITIONS
FRIDAY AND FRIDAY NIGHT. THE HIGH WILL BUILD OVER THE AREA
SATURDAY...BUT LOW PRESSURE MAY IMPACT THE AREA LATER SUNDAY INTO
MONDAY. COLD HIGH PRESSURE WILL RETURN FOR THE MIDDLE PORTION OF
NEXT WEEK.
&&
.NEAR TERM /TONIGHT/...
A WINTRY MIX OF FREEZING RAIN...SLEET AND SNOW IS EXPECTED FOR MUCH
OF THE OUTLOOK AREA THIS AFTERNOON AND EARLY EVENING AND THEREFORE A
A WINTER WEATHER ADVISORY IS IN EFFECT.
HIGH PRESSURE CONTINUES TO MOVE OFF THE CAROLINA COAST THIS
AFTERNOON AND SOUTHERLY FLOW HAS INCREASED ACROSS THE REGION. A COLD
FRONT IS DRAPED FROM LAKE ERIE TO OH/IN TO KY. AHEAD OF THE COLD
FRONT AND IN RESPONSE TO A SHORTWAVE TROUGH AND WAA...PRECIPITATION
WILL CONTINUE TO MOVE ACROSS THE APPALACHIAN MTNS AND HIGHLANDS THIS
AFTERNOON. A NOSE OF +3 WARM AIR WILL CONTINUE TO MOVE INTO THE REGION AT
850MB. SOUTHERLY FLOW AT THE SFC HAS ALLOWED TEMPS TO CLIMB BUT COLD
SURFACES FROM RECENT COLD TEMPS AND SNOWPACK HAS SLOWED THEM FROM
CLIMBING MUCH. MANY OBS ARE AOB FREEZING AROUND WASHINGTON DC AND
BALTIMORE AND NORTH AND WEST ARE SUCH THAT. SOUTHERLY FLOW AT THE
SFC HAS MAINLY ALLOWED TEMPS IN VALLEYS IN CENTRAL
FOOTHILLS...PIEDMONT AND SOUTHERN MD TO RISE TO THE MID TO UPPER
30S. THIS TREND WILL CONTINUE AS BOUNDARY LAYER WINDS ARE EXPECTED
TO INCREASE TO 10-15KTS. THIS IS A BORDERLINE EVENT SINCE MANY ROAD
TEMPS ARE ABOVE FREEZING BUT MESONET OBS ARE NOT. EVEN THOUGH ASOS
AND AWOS SITES ARE WELL ABOVE FREEZING...MANY OBS BETWEEN THOSE
SITES ARE NOT. THEREFORE...PRECIPITATION MOVING EASTWARD MAY MELT
AND FREEZE ON CONTACT ESPECIALLY ON UNTREATED SURFACES. FURTHER
NORTH NEAR THE MD/PA BORDER...COLDER TEMPS ALOFT MAY LEAD TO MORE
SLEET AND SNOW THAN FZRA BUT ALL FROZEN PTYPES ARE POSSIBLE TODAY.
THEREFORE A WINTER WEATHER ADVISORY WAS ISSUED FOR THIS AFTERNOON
AND EVENING.
THE HRRR HAS BEEN FOLLOWING THE PRECIPITATION RATHER WELL THIS
MORNING. ANTICIPATE PRECIPITATION TO BE EAST OF THE WESTERN SHORE OF
THE CHESAPEAKE BAY BY 8PM. TEMPS SOUTH OF WASHINGTON DC ARE EXPECTED
TO BE ABOVE FREEZING AND THEREFORE RAIN AND SLEET ARE THE MAIN
PRECIP TYPES IN THIS REGION. THE FRONT WILL FOLLOW BEHIND AND MOVE ACROSS
THE MID-ATLANTIC TONIGHT REACHING THE CHESAPEAKE BAY BY LATE
TONIGHT. NW WINDS WILL MOVE IN BEHIND THE FRONT AND UPSLOPE SNOW
SHOWERS ARE EXPECTED ACROSS THE WESTERN SLOPES OF THE ALLEGHENY
FRONT. SNOW ACCUMULATION IS EXPECTED AS LAPSE RATES STEEPEN IN THE
SNOW GROWTH ZONE. A WINTER WEATHER ADVISORY CONTINUES FOR THE
WESTERN SLOPES FOR ACCUMULATING SNOW INTO FRIDAY. ACCUMULATION OF
4-8 INCHES ARE POSSIBLE IN THESE LOCATIONS.
VORTICITY ADVECTION WILL BE ROTATING AROUND THE MAIN TROUGH
TONIGHT AND TOMORROW. DRY WESTERLY WIND EAST OF THE ALLGHENY FRONT
SHOULD LIMIT PRECIP FROM REACHING THE GROUND. FCST MIN TEMPS WILL
REACH THE 20S IN THE MTNS AND LOW TO MID 30S FROM WASHINGTON DC AND
SOUTH AND EAST ALONG I-95.
&&
.SHORT TERM /FRIDAY/...
HIGH PRES BLDG INTO THE MID ATLC WL LEAD TO A STRNG PRES GRAD
ACROSS THE AREA. THIS IN TURN WL LEAD TO A WINDY DAY. BUFKIT
X-SXNS ARE SHOWING INXS OF 40 KT A FEW THOUSAND FT OFF THE GRND.
THIS WL HV THE PTNL TO BE BROUGHT TO THE SFC. WE ARE ADVSRTSG THE
PSBLTY OF A WIND ADVSRY - MOST LKLY AREAS WL BE ABV 1500 FT AND
ACROSS THE NRN 1/2 OF THE FCST AREA.
HIGHS IN THE LM30S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
HIGH PRES BLDG OVR THE RNG FRI NGT WL LEAD TO CHILLY TEMPS. LOWS
IN THE TEENS ACROSS MUCH OF THE AREA. WINDS WL BE DIMINISHING
OVRNGT...BUT W/ COLD TEMPS WINDS CHILLS XPCTD TO BE IN THE SINGLE
DIGITS E OF THE MTNS. PRSNTLY SEEING VALUES AS LOW AS -14 IN THE
HIGHLANDS. IF THIS TREND CONTS A WIND CHILL ADVSRY WL BE NEEDED
FOR OUR FAR WRN AREA.
SAT LOOKS TO BE M SUNNY BUT COLD W/ HIGHS RANGING FM THE U20S TO
THE MU30S OVR MOST OF THE AREA.
SAT NGT WL BE COLD...BUT A LTL WARMER THAN FRI NGT. NO WINDS SO
WIND CHILL WL NOT BE A CONCERN.
WHAT HAD BEEN A SPLIT IN THE MODELS BETWEEN A LOW TRACK TO OUR NORTH
AND ANOTHER TRACK TO OUR SOUTH SEEMS TO BE CONSOLIDATING AROUND THE
SOUTHERN TRACK NOW...TAKING IT EAST THRU S VA OR NC. THAT SUPPORTS
SNOW FOR MUCH IF NOT ALL OF OUR REGION. WOULD BE PASSING THRU AT A
GOOD CLIP BUT ACCUMULATING SNOW CERTAINLY A POSSIBILITY FOR SUN
AFTERNOON INTO MONDAY MORNING.
HIGH PRESSURE WILL FOLLOW FOR TUE. NEXT COLD FRONT POISED FOR
WEDNESDAY.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
A WINTRY MIX IS EXPECTED THIS AFTERNOON AND EVENING FOR THE
TERMINALS. PRECIP WILL MOVE QUICK AND FROM WEST TO EAST THROUGH THE
REGION TODAY ENDING ACROSS BWI-MTN-DCA BY 8PM. MVFR CONDITIONS
POSSIBLE AT MRB-IAD-DCA-MTN-BWI AS COLDER AIR FURTHER NORTH GIVES A
GREATER POTENTIAL FOR SNPL. FURTHER SOUTH..CHO SHOULD STAY RAPL. S
WINDS 10-15KTS WILL CONTINUE TODAY AND TONIGHT AHEAD OF A COLD
FRONT. A STRONG FROPA IS EXPECTED TONIGHT WITH NW WINDS 20-25KTS G
35-40 EXPECTED LATE TONIGHT AND FRIDAY ACROSS THE TERMINALS.
WINDY CONDS FRI AND FRI NGT AS HIGH PRES BLDS INTO THE AREA. NO
PROBS XPCTD AVIATION-WISE SAT OR SAT NGT.
SNOW AND IFR CONDITIONS ARE POSSIBLE SUNDAY AFTERNOON INTO MONDAY
MORNING AS LOW PRESSURE SLIDES BY TO OUR SOUTH. VFR FOR TUESDAY.
&&
.MARINE...
A WINTRY MIX WILL MOVE ACROSS THE WATERS THIS EVENING. A MIX OF SNOW
SLEET AND RAIN ARE POSSIBLE BUT SHOULD END BY LATE TONIGHT.
SOUTHERLY WINDS WILL CONTINUE ON THE WATERS THROUGH TONIGHT BEFORE A
STRONG FROPA MOVES ACROSS THE WATERS BY FRIDAY MORNING. NW WINDS
20-25KT GUST AROUND 45KTS POSSIBLE. SCA ARE IN EFFECT AND WILL
TRANSITION TO A GALE WARNING FRIDAY.
A GALE WRNG IS IN EFFECT FM FRI MRNG THRU THE ERLY HRS OF SAT
MRNG..AND THEN AN SCA WL LKLY GO INTO EFFECT AFTRWARDS FOR THE
RMNDR OF THE NGT. WINDS WL BE DIMINISHING FOR SAT AND SAT NGT.
GUSTY WINDS AND A SMALL CRAFT ADVISORY ARE POSSIBLE ON MONDAY INTO
MONDAY NIGHT AS LOW PRESSURE INTENSIFIES OFFSHORE.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...WINTER WEATHER ADVISORY UNTIL NOON EST FRIDAY FOR MDZ501.
WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR MDZ003-
502.
WINTER WEATHER ADVISORY UNTIL 9 PM EST THIS EVENING FOR
MDZ004>006-011-503>508.
VA...WINTER WEATHER ADVISORY UNTIL NOON EST FRIDAY FOR VAZ503.
WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR VAZ027-
028-030-031-504.
WINTER WEATHER ADVISORY UNTIL 9 PM EST THIS EVENING FOR VAZ052-
053-501-505-506.
WV...WINTER WEATHER ADVISORY UNTIL NOON EST FRIDAY FOR WVZ501-503-
505.
WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR
WVZ050>053-055-502-504-506.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ530>534-
537>543.
GALE WARNING FROM 6 AM FRIDAY TO 1 AM EST SATURDAY FOR
ANZ530>543.
SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ535-
536.
&&
$$
PRODUCTS...HAS/WOODY!/CAS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
606 PM EST FRI JAN 30 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 406 PM EST FRI JAN 30 2015
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM
HUDSON BAY INTO THE NE CONUS RESULTING IN NW FLOW THROUGH THE NRN
GREAT LAKES. AN UPSTREAM SHORTWAVE TROUGH WAS LOCATED OVER SRN
MANITOBA. THE SHRTWV AND ASSOCIATED WAA PATTERN SUPPORTED SOME LIGHT
SNOW FROM FAR NRN MN INTO NW ONTARIO WITH VSBY INTO THE 1-3SM RANGE.
AT THE SFC...A RIDGE EXTENDED FROM THE MID MS VALLEY INTO THE WRN
GREAT LAKES. BACKING WINDS TO SW OVER WRN LAKE SUPERIOR AND W OVER
THE ERN LAKE HAVE PUSHED THE LES BANDS OFFSHORE EXCEPT FOR SOME
LINGERING FLURRIES NEAR GRAND MARAIS.
TONIGHT...EXPECT MID/HIGH CLOUDS TO THICKEN INTO THIS EVENING AS THE
AS THE SHRTWV APPROACHES. UPSTREAM TRENDS AND MODELS FCST 285K-290K
ISENTROPIC LIFT...SUGGESTS THAT THE AREA OF LIGHT SNOW WILL SPREAD
THROUGH UPPER MICHIGAN BTWN 03Z-09Z. WITH LITTLE MOISTURE AVAILABLE
AND DRY LOW LEVELS DELAYING THE ONSET OF THE PCPN...QPF OF 0.05 OR
LOWER WITH SLR VALUES NEAR 20/1 WOULD ONLY RESULT IN SNOW AMOUNTS OF
AN INCH OR LESS. HOWEVER...AS LOW LEVEL CONV INCREASES ALONG THE SFC
FRONT/TROUGH AND 850 MB TEMPS DROP TO AROUND -12C...THERE MAY BE A
BRIEF PERIOD OF LAKE ENHANCED SNOW INTO NW UPPER MI THAT MAY BRING
TOTALS INTO THE 1 TO 2 INCH RANGE.
SAT...THE AREA OF LOW LEVEL CONV WITH THE FRONT WILL SLIDE THROUGH
THE REST OF THE NRN CWA WITH THE POTENTIAL FOR A NARROW BAND OF
MODERATE SNOW. ALTHOUGH 850 MB TEMPS DROP TO NEAR -20C BY 00Z
SUN...A QUICK TRANSITION TO A MORE DIFFLUENT/ANTICYCLONIC LOW-LVL
NORTHERLY FLOW AND FALLING INVERSIONS AT OR BELOW 4KFT WILL LIMIT
LES INTENSITY THE REST OF THE DAY. SNOW ACCUMULATIONS OF ONLY AROUND
AN INCH ARE EXPECTED. AFTER MIDDAY HIGHS RANGING FROM THE TEENS NW
TO MID TO UPPER 20S SCNTRL...TEMPS WILL DURING THE AFTERNOON AS
BRISK N TO NW WINDS USHER ARCTIC AIR MASS INTO THE AREA. GUSTY WINDS
WILL ALSO CREATE BLSN IN OPEN AREAS NEAR LAKE SUPERIOR.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 424 PM EST FRI JAN 30 2015
COLD WEATHER PATTERN IN STORE FOR MUCH OF EXTENDED. TEMPS WILL BE
MUCH BLO NORMAL...ESPECIALLY FOR DAYTIME HIGHS. NORMAL HIGHS FOR
FIRST PORTION OF FEBRUARY ARE IN THE LOWER TO MIDDLE 20S...AND THERE
WILL BE A FEW DAYS NEXT WEEK WHERE HIGHS STAY BLO 10 ABOVE. TROUGHING
ALOFT EXPANDS FM NORTHERN CANADA OVER GREAT LAKES AND MOST OF THE
EASTERN CONUS AS RIDGING TEMPORARILY BUILDS OVER THE WEST COAST. LEAD
SHOT OF ARCTIC AIR DROPS OVER GREAT LAKES SECOND HALF OF THE WEEKEND
WITH H85/5KFT AGL TEMPS BLO -20C/-3F. ANOTHER STRONGER PUSH OF COLDER
AIR IS DUE IN THE MIDDLE OF THE WEEK AS H85 TEMPS DROP TO AT LEAST
-25C/-13F. COULD BE A WIDESPREAD SNOW JUST AHEAD OF THAT REINFORCING
COLD FRONT TUESDAY NIGHT INTO WEDNESDAY. SINCE THE RIDGING OVER THE
WEST COAST IS NOT THAT SHARP...WESTERN RIDGE AND EASTERN TROUGH
PATTERN BREAKS DOWN BY NEXT WEEKEND WITH TEMPS MODERATING BACK TOWARD
NORMAL...POSSIBLY ABOVE...BY NEXT WEEKEND.
COLD FRONT MOVES EAST OF THE AREA ON SATURDAY NIGHT. ARCTIC HIGH
PRESSURE BUILDS FM THE CANADIAN PRAIRIES TO THE NORTHERN PLAINS.
RIDGING EXTENDS NORTH OF LK SUPERIOR WITH CONFLUENT FLOW ALOFT.
SOUNDINGS INDICATE INVERSIONS 4 TO POSSIBLY 6 KFT WITH DELTA T/S
INCREASING FM AROUND 18C SATURDAY EVENING TO 25C BY SUNDAY MORNING.
MAJORITY OF DGZ NOT WITHIN LAKE CONVECTIVE LAYER...SO SNOWFLAKE SIZE
AND THUS SLR/AMOUNTS WILL BE HELD DOWN TO AROUND 20:1 OR EVEN LOWER.
LOW-LEVEL WINDS START OUT NNW-N ON SATURDAY EVENING AND TURN TO NNE
BY SUNDAY AS RIDGING EXPANDS NORTH OF LK SUPERIOR. SETUP FAVORS LES
WITH MAINLY LIGHT ACCUMS FOR FAR WEST CWA AND OVER THE NCNTRL CWA.
SOUNDINGS INDICATE POSSIBLE WEAK LAKE ENHANCED SETUP AS SWATH OF H7-
H5 MOISTURE MOVES ACROSS SATURDAY EVENING INTO SUNDAY MORNING.
EXTENT OF DRYING BTWN THE MID-LEVEL MOISTURE AND LAKE CONVECTIVE
LAYER MAY BE TOO MUCH TO OVERCOME THOUGH AS LIFT ALOFT IS WEAK. LOW-
LEVEL CONVERGENCE VCNTY OF NORTH CENTRAL UPR MICHIGAN MAY MAKE UP
FOR OVERALL MARGINAL SETUP FOR LES...BUT EVEN SO...DO NOT EXPECT
MORE THAN A FEW INCHES OF SNOW SATURDAY NIGHT INTO SUNDAY FOR
FAVORED AREAS. WINDS ARE NOT VERY STRONG...SO SNOW SHOWERS MAY TRY
TO STAY CONFINED TOWARD THE SHORE INSTEAD OF SETTING UP OVER THE
HIGHER TERRAIN.
DESPITE THE ARRIVAL OF THE ARCTIC AIR...WINDS SHOULD NOT BE TOO
STRONG...LIMITING THE OVERALL IMPACT. TEMPS SATURDAY NIGHT SHOULD
FALL WELL BLO ZERO OVER THE EAST WITH DRAINAGE FLOW OFF ONTARIO.
OTHERWISE...NE FLOW AND WEALTH OF STRATUS OFF LK SUPERIOR BENEATH A
SUBSIDENCE INVERSION WILL RESTRICT TEMPS FM FALLING BLO ZERO.
STRATUS SHOULD STAY IN PLACE FOR MUCH OF SUNDAY...EXCEPT OVER THE
FAR EAST. HIGHS ON SUNDAY WILL STAY IN THE SINGLE DIGITS AND MAY
JUST STRUGGLE ABOVE ZERO IN THE FAR EAST CWA. ARRIVAL OF ANOTHER
SHORTWAVE FM THE NORTHWEST ACROSS THE PLAINS WILL BRING A SWATH OF
SNOW TO AS CLOSE AS NORTHERN WI LATE SATURDAY NIGHT. THAT SYSTEM
PHASES WITH ANOTHER MOVING OUT OF THE REMNANT OF CURRENT SOUTHWEST
CONUS LOW TO PROVIDE WIDESPREAD SNOW ON SUNDAY ALONG DEVELOPING SFC
LOW OVER MAINLY SOUTHERN PORTIONS OF WISCONSIN AND MICHIGAN. LOOKS
LIKE UPR MICHIGAN WILL MISS THIS STORM SYSTEM. EXPECT LINGERING
WEAKENING LES FOR SNOW BELTS TO EAST OF MARQUETTE AND POSSIBLY OVER
THE NORTHWEST CWA. LES WILL CONTINUE TO DRIFT MAINLY OFFSHORE ON
SUNDAY NIGHT AS WINDS IN BLYR SLOWLY BACK TO THE WEST ON EDGE OF
HIGH PRESSURE SINKING OVER THE MIDDLE MISSISSIPPI RIVER VALLEY.
CHILLY TEMPS FOR SUNDAY NIGHT WELL BLO ZERO...ESPECIALLY IN THE WEST
INTERIOR AND ALSO EAST CWA WITH CONTINUATION OF LOW-LEVEL FLOW OFF
ONTARIO. SINCE WINDS ARE LIGHT AND CALM...NO WIND CHILL ISSUES ARE
EXPECTED.
LES DRIFTS FARTHER EAST TO SNOW BELTS EAST OF MUNISING AND LIKELY
INCREASES ON THE KEWEENAW AS WINDS BECOME MORE CONVERGENT FM THE
WEST. SETUP THEN MAY BECOME FAVORABLE FOR MODERATE TO POSSIBLY HEAVY
LAKE ENHANCED SNOW FOR NORTHERN KEWEENAW LATE MONDAY INTO TUESDAY
MORNING AS WSW FLOW RESULTS IN STRONG CONVERGENCE BAND TO FORM WHILE
SHORTWAVE WITH ADDITIONAL MID-LEVEL LIFT AND MOISTURE SLIDES ACROSS.
SOUNDINGS INDCIATE THAT INVERSIONS REACH MORE TOWARD 8KFT WITH
INVERSION TOP TEMPS NEARING -24C. POTENTIAL FOR HEAVY SNOW WITH
RATES OVER 1 INCH PER HOUR WILL GREATLY DEPEND ON WHERE SHARPEST
CONVERGENCE ALLIGNS. TOUGH TO TELL THAT AT THIS POINT WHERE THAT
OCCURS...BUT WORTH AN HWO MENTION AS THIS TYPE OF LES PATTERN CAN
RESULT IN A LOT OF SNOW IN JUST A FEW HOURS.
ON INTO TUESDAY...LOW PRESSURE SYSTEM WILL BE ADVANCING ACROSS THE
NORTHERN PLAINS. AREA OF H7-H5 Q-VECTOR CONVERGENCE TO THE NORTH AND
EAST OF THE LOW AND AREA OF DIVERGENCE IN RIGHT ENTRANCE REGION OF
JET STREAK SLIDING OVER THE UPPER GREAT LAKES SHOULD SPREAD AN AREA
OF LGT SNOW WEST TO EAST ACROSS THE WESTERN GREAT LAKES. WENT WITH
LOW POPS AWAY FM LAKE EFFECT AREAS...ESPECIALLY AS THE ECMWF KEEPS
MOST WIDESRPEAD QPF SOUTH OF UPR MICHIGAN. LOW PRESSURE SYSTEM
SHOULD BE JUST EAST OF UPR MICHIGAN WEDNESDAY MORNING WITH STRONGER
COLD FRONT POISED TO SWEEP ACROSS. EXPECT NW FLOW LAKE EFFECT TO
RAMP UP WEDENSDAY AFTN AS NEW SURGE OF COLD AIR RETURN TO THE AREA.
ECMWF/GFS VARYING ON HOW COLD IT GETS AT H85. BLEND OF 12Z RUNS
SUGGEST H85 TEMPS END UP AROUND -27C/-17F WHICH WITH LAKE TEMPS IN
ICE FREE AREAS AROUND 2C/35F YIELDS PLENTY OF OVER-WATER
INSTABILITY. ALSO...COMPARED TO THE RECENT LAKE EFFECT EVENTS...THE
FORECAST SOUNDINGS INDICATE INVERSIONS MAY CLIMB TOWARD 8KFT. DUE TO
THE COLD AIR...SLR/S WILL BE LOWER...BUT WHATEVER LES OCCURS WILL BE
EFFICIENT AT REDUCING VSBY. SEEMS THAT SOME HAZARDS FOR THE SNOW AND
BLSN MAY BE NEEDED AND LOW VSBY AFFECT WOULD ONLY BE ENHANCED DUE TO
THE ICE COVER NEAR THE SHORELINE OF LK SUPERIOR. WILL MENTION THIS
IN THE HWO.
WILL BE AROUND WIND CHILL ADVISORY CRITERIA FOR AT LEAST WESTERN CWA
LATE WEDNESDAY NIGHT INTO THURSDAY MORNING AS TEMPS DROP TOWARD 10
BELOW AND WINDS ARE AT LEAST 5-10 MPH FM THE NW. ELSEWHERE...NW FLOW
OFF LK SUPERIOR WILL MODERATE TEMPS AND KEEP WIND CHILLS ABOVE 20
BELOW. LES DIMINISHES AND EVENTUALLY ENDS BY NEXT FRIDAY AS WINDS
BACK SW WITH HIGH PRESSURE DROPPING ACROSS THE CENTRAL PLAINS. COLD
FOR ALL ON FRIDAY MORNING WITH MOST AREAS BLO ZERO...BUT WINDS SHOULD
BE LIGHT ENOUGH TO RESTRICT WIND CHILL ISSUES AT THAT TIME.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 606 PM EST FRI JAN 30 2015
VFR CONDITIONS ARE EXPECTED AT ALL SITES INTO THIS EVENING. A TROUGH
OVER NW MN WILL CROSS CENTRAL LAKE SUPERIOR BY 12Z. LOOK FOR
-SN TO MOVE IN DURING THE EVENING HOURS...AND PICK UP IN INTENSITY
ALONG AND BEHIND THE FRONT AND CONDITIONS AT SAW AND IWD WILL FALL
TO MVFR AND STAY THERE THROUGH THE REST OF THE FORECAST PERIOD. LES
AND GUSTY WINDS PRODUCING BLSN AND LOWER VSBY INTO IFR CATEGORY IS
EXPECTED AT CMX BY MID EVENING BEFORE GOING TO MVFR BY AFTERNOON.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 424 PM EST FRI JAN 30 2015
BRIEF LULL IN STRONGER WINDS OVER LK SUPERIOR ATTM AS HIGH PRESSURE
DRIFTS ACROSS. STRONG COLD FRONT CROSSING ON SATURDAY WILL BRING IN
ANOTHER SURGE OF STRONG WINDS...POSSIBLY REACHING 35 KT GALES
SATURDAY AFTN INTO SATURDAY EVENING. LEFT THE GALE WATCH UP AS IT IS
ONLY A MARGINAL SETUP FOR GALES. MID SHIFT CAN MAKE THE FINAL CALL.
DID PUT UP HEAVY FREEZING SPRAY WARNING AS THAT IS MORE CERTAIN.
WINDS BECOME LIGHT BY SUNDAY AS HIGH PRESSURE DRIFTS ACROSS. WINDS
INCREASE FM THE WSW ON MONDAY NIGHT AHEAD OF ANOTHER LOW PRESSURE AND
COLD FRONT THAT SWEEP OVER THE AREA ON TUESDAY NIGHT AND WEDNESDAY.
BEHIND THAT FRONT...ANOTHER PERIOD OF GALES AND HEAVY FREEZING SPRAY
IS EXPECTED INTO THURSDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING FROM NOON SATURDAY TO 5 AM EST
SUNDAY FOR LSZ264-266-267.
GALE WATCH FROM SATURDAY AFTERNOON THROUGH SATURDAY EVENING FOR
LSZ264-266-267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...07
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1259 PM EST THU JAN 29 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 457 AM EST THU JAN 29 2015
WV AND LATEST RADAR IMAGERY SHOW IT WELL...THE DEEP MOISTURE SET UP
ACROSS CENTRAL UPPER MI IS QUICKLY EXITING E. THE SFC TROUGH SET UP
OVER W LAKE SUPERIOR AROUND 09Z THIS MORNING WILL EDGE TO THE E HALF
OF THE CWA SHORTLY AFTER DAYBREAK THIS IS WHEN WE WILL REALLY BEGIN
TO NOTICE SOME OF THOSE STRONGER N-NNW WINDS BEGIN /WINDS CURRENTLY
AROUND 12KTS AT CMX WILL BEGIN TO GUSTS 25-30KTS/.
-FZDZ HAS BEEN REPORTED OFF AND ON THIS MORNING AS THE MAIN BULK OF
MOISTURE EXISTS OVER CENTRAL AND E UPPER MI...AS STRONG HIGH
PRESSURE OVER CENTRAL SASKATCHEWAN NEARS. UTILIZED THE PROBABILITY
OF ICE PRESENT FROM THE RUC TO GET A BETTER HANDLE ON WHEN AND WHERE
-FZDZ MAY SET UP BEFORE COLD AIR PUSHES ACROSS ALL OF UPPER MI
/BASICALLY BY 18Z/ FOR ANY LINGERING MIXED PRECIP TO TRANSITION BACK
TO JUST -SHSN. LOOK FOR FALLING TEMPS THIS AFTERNOON AS THE COLDER
AIR SLIDES IN. 850MB TEMPS AROUND -10C EARLY THIS MORNING WILL FALL
THIS AFTERNOON...AND GET DOWN TO AROUND -17C BY 00Z...AND -20C BY
06Z FRIDAY. THE ARRIVAL OF THE COLDER AIR WILL BRING A BETTER CHANCE
OF LAKE EFFECT SNOW SHOWERS TO UPSLOPE LOCATIONS OVER THE W FAVORED
BY NNW WINDS.
LIMITING FACTORS FOR SIGNIFICANT SNOW ACCUMULATIONS OVER THE W THIRD
OF THE CWA LATER THIS AFTERNOON THROUGH THIS EVENING WILL BE THE
LOWERING DGZ TO AROUND 4KFT OR LESS BY 06Z FRIDAY...WINDS STILL
GUSTING 15-20KTS WILL KEEP SLR VALUES FROM RISING BACK UP TO
25:1 TOO FAST. HOWEVER...WITH THE 500MB TROUGH OVERHEAD AND AN
ADDITIONAL SHORTWAVE SLIDING THROUGH LATE THIS AFTERNOON THROUGH
THIS EVENING...SOME ENHANCEMENT IS EXPECTED. WILL KEEP SNOW AMOUNTS
AROUND 2IN OR LESS ACROSS THE W THIRD OF THE CWA.
ONE CONCERN FOR THE EVENING PERIOD WILL BE THE POTENTIAL OF A MESO
LOW SETTING UP OVER S CENTRAL LAKE SUPERIOR AFTER 03Z...KEEPING A
BAND OF MORE MODERATE SNOW OVER CENTRAL/E MARQUETTE COUNTY
AND W ALGER COUNTY. THE NAM AND REGIONAL WRF HIGHLIGHT THE
POTENTIAL. HAVE EXPANDED SNOW FARTHER W TO ACCOUNT FOR THIS...AS
WELL AS KEPT THE WINDS UP OVER S CENTRAL LAKE SUPERIOR A BIT LONGER
/WHICH SEEMS TO HAVE BEEN ALREADY ACCOUNTED FOR/. ENHANCED BY THE
WINDS GUSTING 25-35KTS...VISIBILITY RESTRICTIONS WILL BE A CONCERN
FOR THOSE TRAVELING ON M-28. EVEN WITHOUT ANY LAKE ENHANCEMENT
BLOWING AND DRIFTING SNOW COULD BE AN ISSUE...DEPENDING ON HOW SOLID
SNOW BANKS ON THE SIDE OF THE ROAD HAVE BECOME AND HOW MUCH SNOW HAS
BEEN ABLE TO ACCUMULATE ON THE ICE ALONG LAKE SUPERIOR.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 411 AM EST THU JAN 29 2015
FCST FOCUS IN THE MEDIUM AND EXTENDED RANGE WL BE ON THE IMPACT OF
SEVERAL CLIPPER TYPE SHRTWVS THAT ARE FCST TO MOVE THRU A MEAN UPR
TROF IN ERN NAMERICA. UNDER THE PERSISTENT NW FLOW ALOFT...EXPECT
BLO TO WELL BLO NORMAL TEMPS TO DOMINATE DURING THIS TIME WITH A
STEADY FEED OF CNDN AIR. WITH THE COLD AIR SURGES...LES WL BE AN
OBVIOUS CONCERN.
FRI...SFC HI PRES IS FCST TO SHIFT FM OVER MN TOWARD THE OH RIVER
VALLEY BE 00Z SAT. AS NW WINDS IN THE MRNG BACK TO THE W AND THEN
THE SW LATE...LINGERING LES OVER THE W WL BECOME CONFINED TO OVER
THE KEWEENAW AND END OVER THE E EXCEPT NEAR THE SHORE E OF GRAND
MARAIS TOWARD 00Z SAT. ALTHOUGH THE LK CLDS WL BE SHIFTING
OFFSHORE...MORE MID/HI CLDS IN ADVANCE OF ANOTHER SHRTWV MOVING SE
WITHIN THE NW FLOW ALF WL BE PUSHING INTO THE UPR LKS.
FRI NGT/SAT...SHRTWV EMBEDDED IN THE NW FLOW ALOFT WL BE MOVING INTO
NW MN AT 00Z SAT AND IS THEN FCST TO SLIDE SE THRU NCENTRAL WI BY
12Z SAT AND THEN ACROSS LOWER MI ON SAT. AT THE SAME TIME...ANOTHER
STRONGER SHRTWV WL BE MOVNG FM CENTRAL CANADA INTO FAR NW ONTARIO BY
12Z SAT BEFORE MOVING TO JUST S OF JAMES BAY BY 00Z SUN. UPR MI WL
BE IMPACTED MAINLY BY THE WEAKER SRN DISTURBANCE. ALTHOUGH A BAND OF
RELATIVELY WEAK QVECTOR CNVGC IS FCST TO SLIDE ACROSS UPR MI ON FRI
NGT INTO SAT MRNG ON THE CYC SIDE OF THIS SRN SHRTWV...ACCOMPANYING
ISENTROPIC ASCENT/MSTR INFLOW IS FCST TO BE RELATIVELY WEAK. SO WL
FCST ONLY CHC POPS OVER MOST OF THE CWA AND MAINLY BTWN 03Z SAT AND
15-18Z SAT...WHEN THE FORCING ACCOMPANYING THE SRN SHRTWV AND A COLD
FNT ATTENDANT TO THE NRN SHRTWV ARE FCST TO EXIT THE ERN CWA AND
GIVE WAY TO SOME VIGOROUS DEEP LYR QVECTOR DVGC. MAINTAINED SOME
LIKELY POPS OVER THE NRN TIER OF THE CWA CLOSE TO THE STRONGER NRN
SHRTWV AND WHERE SHARPER LLVL CNVGC WL ACCOMPANY THE SAT COLD FROPA.
THE COLDEST 00Z GFS/12Z ECMWF RUNS SHOW H85 TEMPS IN THE WAKE OF THE
SAT COLD FROPA PLUNGING AS LO AS -25C BY 00Z SUN...BUT QUICK
TRANSITION TO A MORE DIFFLUENT/ACYC H925 N FLOW AND INVRN BASE
FALLING TO H85-875 WL TEND TO LIMIT LES INTENSITY. RELATIVELY
MODERATE TEMPS INTO SAT MRNG WL FALL THRU THE AFTN AS THE COLDER AIR
SURGES INTO THE AREA IN THE STEADY N FLOW AHEAD OF ARCTIC HI PRES
BLDG SEWD IN SCENTRAL CANADA.
SAT NGT THRU SUN NGT...UPR MI WL REMAIN DOMINATED BY A COLD N
BACKING WNW LLVL FLOW OF ARCTIC AIR ASSOCIATED WITH ARCTIC HI PRES
MOVING FM OVER ALBERTA/SASKATCHEWAN AT 00Z SUN INTO THE UPR MS RIVER
VALLEY BY 12Z MON. EXPECT TEMPS TO RUN WELL BLO NORMAL AND LES TO
CONTINUE NEAR LK SUP WITH H85 TEMPS FCST TO REMAIN NOT FAR FM -22C
TO -25C. SAT NGT COULD BE PARTICULARLY CHILLY OVER THE E WITH THE N
H925 FLOW ALLOWING SOME DRAINAGE OF COLD AIR INTO THAT AREA OFF
ONTARIO. ALTHOUGH FCST ACYC NATURE OF THE H925 FLOW AND NEAR ABSENCE
OF THE DGZ ASSOCIATED WITH THE VERY LO H85 TEMPS WL LIMIT LES
AMOUNTS...SOME OF THE MODELS HINT THERE MAY BE SOME ENHANCED CNVGC
ALONG A LK INDUCED TROF STRETCHING FM THE KEWEENAW TOWARD WHITEFISH
PT THAT WL INTENSIFY AS THE LARGER PRES GRADIENT RELAXES AND A
SHRTWV EMBEDDED IN THE NW FLOW APRCHS ON SUN/SUN NGT. RAISED POPS
WELL ABOVE THE CONSENSUS TO LIKELY ALONG THIS AXIS.
MON...LES ALONG THE LK INDUCED TROF WL BEGIN TO DIMINISH/SHIFT OUT
INTO LK SUP WITH THE APRCH OF A SFC RDG AXIS EXTENDING N FM THE HI
CENTER SHIFTING TOWARD THE OH VALLEY AND THE ASSOCIATED BACKING LLVL
FLOW. BUT THE MORE W WIND COMPONENT WL MEAN LESS LK MODERATION AND
PERSISTENT WELL BLO NORMAL SFC TEMPS EVEN AS THE H85 TEMPS MODERATE
A BIT FASTER.
TUE/WED...THE LONGER RANGE GUIDANCE HINTS ANOTHER CLIPPER TYPE
DISTURBANCE WL PASS THRU THE UPR LKS ON TUE...WITH H85 TEMPS
REBOUNDING TO NEAR -15C IN THE WAA BTWN THIS FEATURE AND HI PRES
MOVING INTO THE MID ATLANTIC. BUT ANOTHER ARCTIC SURGE LOOKS TO
FOLLOW ON WED AS THE SHRTWV PASSAGE REAMPLIFIES THE ERN TROF AND THE
NW FLOW IN ADVANCE OF THE NEXT CNDN HI SINKING INTO THE NRN PLAINS
ADVECTS H85 TEMPS AS LO AS -25 TO -28C INTO THE UPR LKS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1258 PM EST THU JAN 29 2015
COLD FRONT IS EAST OF UPPER MICHIGAN AND BLUSTERY NORTHWEST WINDS OF
20-30 KTS IN GUSTS ARE ALREADY OCCURRING. EVENTUALLY THERE WILL BE A
SWITCH BACK TO MORE NUMEROUS LAKE EFFECT SNOW SHOWERS. OFF AND ON
ISOLD SNOW SHOWERS WILL AFFECT KIWD AND KCMX THIS AFTN WITH A WINDOW
FOR GREATER COVERAGE AND INTENSITY LATE THIS AFTN AS LIFT INCREASES
DUE TO AN UPPER LEVEL DISTURBANCE. SNOW SHOWERS WILL THEN DIMINISH
AGAIN BY LATE EVENING AS HIGH PRESSURE AND DRIER LOW-LEVEL AIR
ARRIVE FM THE NORTHWEST. AT KSAW...WILL HAVE TO CONTEND WITH MIX OF
SNOW AND FZDZ THIS AFTN BEFORE COLDER AIR SWITCHES THE PRECIP TO
LAKE EFFECT SNOW SHOWERS INTO THE EVENING. EXPECT DIMINISHING AND
ENDING TREND TO SNOW SHOWERS OVERNIGHT TONIGHT. WINDS WILL REMAIN
GUSTY AT ALL THE TAF SITES UNTIL LATER TONIGHT. VSBY MAINLY MVFR AT
ALL THE SITES THOUGH MAY DIP TO IFR BRIEFLY LATE THIS AFTN OR EARLY
EVENING. BY LATE TONIGHT INTO FRIDAY...MAINLY MVFR OR VFR FLYING
CONDITIONS ARE ANTICIPATED.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 355 AM EST THU JAN 29 2015
LOW PRESSURE SYSTEM NEAR N LAKE SUPERIOR THIS MORNING WILL MOVE INTO
QUEBEC THIS AFTERNOON WHILE ANOTHER LOW NEAR CHICAGO SHIFTS EAST
INTO NEW ENGLAND ON FRIDAY MORNING. MEANWHILE...A HIGH OVER S
CENTRAL CANADA WILL MOVE SE INTO MN ON FRIDAY. IN BETWEEN THE
EXITING LOW AND NEARING HIGH...STRONG N-NNW GALES GUSTING 35 TO
AROUND 40KTS WILL DEVELOP THIS AFTERNOON OVER MAINLY CENTRAL AND E
LAKE SUPERIOR. LOOK FOR WINDS TO SLOWLY DIMINISH LATE THIS EVENING
AND OVERNIGHT...WITH GUSTS REMAINING 25-30KTS THROUGH DAYBREAK
FRIDAY. GIVEN THE STRONG WINDS...AND COLDER AIR SURGING IN...HEAVY
FREEZING SPRAY WILL BE POSSIBLE OVER THIS SAME AREA INTO EARLY
FRIDAY MORNING. WINDS WILL THEN QUICKLY DIMINISH AND REMAIN LESS
THAN 30KTS THROUGH FRIDAY NIGHT.
AS THIS HIGH DRIFTS INTO THE OH RIVER VALLEY ON SATURDAY...A TROUGH
WILL SLIDE ACROSS THE UPPER GREAT LAKES. A FEW N TO NW GUSTS OF 30
TO NEAR 35KTS WILL BE POSSIBLE SATURDAY AFTERNOON AND EVENING.
EXPECT HIGH PRESSURE OVER CENTRAL CANADA ON SATURDAY TO MOVE SE INTO
THE N PLAINS ON SUNDAY...AND THE MID MS RIVER VALLEY ON MONDAY.
WINDS SHOULD DIMINISH FOR A TIME SUN BEFORE INCREASING AGAIN MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST FRIDAY FOR LSZ264-
266-267.
GALE WARNING UNTIL 4 AM EST FRIDAY FOR LSZ265>267.
GALE WARNING UNTIL 1 AM EST FRIDAY FOR LSZ263-264.
HEAVY FREEZING SPRAY WARNING UNTIL 1 AM EST FRIDAY FOR LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KF
LONG TERM...KC
AVIATION...JLA
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
727 AM EST THU JAN 29 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 457 AM EST THU JAN 29 2015
WV AND LATEST RADAR IMAGERY SHOW IT WELL...THE DEEP MOISTURE SET UP
ACROSS CENTRAL UPPER MI IS QUICKLY EXITING E. THE SFC TROUGH SET UP
OVER W LAKE SUPERIOR AROUND 09Z THIS MORNING WILL EDGE TO THE E HALF
OF THE CWA SHORTLY AFTER DAYBREAK THIS IS WHEN WE WILL REALLY BEGIN
TO NOTICE SOME OF THOSE STRONGER N-NNW WINDS BEGIN /WINDS CURRENTLY
AROUND 12KTS AT CMX WILL BEGIN TO GUSTS 25-30KTS/.
-FZDZ HAS BEEN REPORTED OFF AND ON THIS MORNING AS THE MAIN BULK OF
MOISTURE EXISTS OVER CENTRAL AND E UPPER MI...AS STRONG HIGH
PRESSURE OVER CENTRAL SASKATCHEWAN NEARS. UTILIZED THE PROBABILITY
OF ICE PRESENT FROM THE RUC TO GET A BETTER HANDLE ON WHEN AND WHERE
-FZDZ MAY SET UP BEFORE COLD AIR PUSHES ACROSS ALL OF UPPER MI
/BASICALLY BY 18Z/ FOR ANY LINGERING MIXED PRECIP TO TRANSITION BACK
TO JUST -SHSN. LOOK FOR FALLING TEMPS THIS AFTERNOON AS THE COLDER
AIR SLIDES IN. 850MB TEMPS AROUND -10C EARLY THIS MORNING WILL FALL
THIS AFTERNOON...AND GET DOWN TO AROUND -17C BY 00Z...AND -20C BY
06Z FRIDAY. THE ARRIVAL OF THE COLDER AIR WILL BRING A BETTER CHANCE
OF LAKE EFFECT SNOW SHOWERS TO UPSLOPE LOCATIONS OVER THE W FAVORED
BY NNW WINDS.
LIMITING FACTORS FOR SIGNIFICANT SNOW ACCUMULATIONS OVER THE W THIRD
OF THE CWA LATER THIS AFTERNOON THROUGH THIS EVENING WILL BE THE
LOWERING DGZ TO AROUND 4KFT OR LESS BY 06Z FRIDAY...WINDS STILL
GUSTING 15-20KTS WILL KEEP SLR VALUES FROM RISING BACK UP TO
25:1 TOO FAST. HOWEVER...WITH THE 500MB TROUGH OVERHEAD AND AN
ADDITIONAL SHORTWAVE SLIDING THROUGH LATE THIS AFTERNOON THROUGH
THIS EVENING...SOME ENHANCEMENT IS EXPECTED. WILL KEEP SNOW AMOUNTS
AROUND 2IN OR LESS ACROSS THE W THIRD OF THE CWA.
ONE CONCERN FOR THE EVENING PERIOD WILL BE THE POTENTIAL OF A MESO
LOW SETTING UP OVER S CENTRAL LAKE SUPERIOR AFTER 03Z...KEEPING A
BAND OF MORE MODERATE SNOW OVER CENTRAL/E MARQUETTE COUNTY
AND W ALGER COUNTY. THE NAM AND REGIONAL WRF HIGHLIGHT THE
POTENTIAL. HAVE EXPANDED SNOW FARTHER W TO ACCOUNT FOR THIS...AS
WELL AS KEPT THE WINDS UP OVER S CENTRAL LAKE SUPERIOR A BIT LONGER
/WHICH SEEMS TO HAVE BEEN ALREADY ACCOUNTED FOR/. ENHANCED BY THE
WINDS GUSTING 25-35KTS...VISIBILITY RESTRICTIONS WILL BE A CONCERN
FOR THOSE TRAVELING ON M-28. EVEN WITHOUT ANY LAKE ENHANCEMENT
BLOWING AND DRIFTING SNOW COULD BE AN ISSUE...DEPENDING ON HOW SOLID
SNOW BANKS ON THE SIDE OF THE ROAD HAVE BECOME AND HOW MUCH SNOW HAS
BEEN ABLE TO ACCUMULATE ON THE ICE ALONG LAKE SUPERIOR.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 411 AM EST THU JAN 29 2015
FCST FOCUS IN THE MEDIUM AND EXTENDED RANGE WL BE ON THE IMPACT OF
SEVERAL CLIPPER TYPE SHRTWVS THAT ARE FCST TO MOVE THRU A MEAN UPR
TROF IN ERN NAMERICA. UNDER THE PERSISTENT NW FLOW ALOFT...EXPECT
BLO TO WELL BLO NORMAL TEMPS TO DOMINATE DURING THIS TIME WITH A
STEADY FEED OF CNDN AIR. WITH THE COLD AIR SURGES...LES WL BE AN
OBVIOUS CONCERN.
FRI...SFC HI PRES IS FCST TO SHIFT FM OVER MN TOWARD THE OH RIVER
VALLEY BE 00Z SAT. AS NW WINDS IN THE MRNG BACK TO THE W AND THEN
THE SW LATE...LINGERING LES OVER THE W WL BECOME CONFINED TO OVER
THE KEWEENAW AND END OVER THE E EXCEPT NEAR THE SHORE E OF GRAND
MARAIS TOWARD 00Z SAT. ALTHOUGH THE LK CLDS WL BE SHIFTING
OFFSHORE...MORE MID/HI CLDS IN ADVANCE OF ANOTHER SHRTWV MOVING SE
WITHIN THE NW FLOW ALF WL BE PUSHING INTO THE UPR LKS.
FRI NGT/SAT...SHRTWV EMBEDDED IN THE NW FLOW ALOFT WL BE MOVING INTO
NW MN AT 00Z SAT AND IS THEN FCST TO SLIDE SE THRU NCENTRAL WI BY
12Z SAT AND THEN ACROSS LOWER MI ON SAT. AT THE SAME TIME...ANOTHER
STRONGER SHRTWV WL BE MOVNG FM CENTRAL CANADA INTO FAR NW ONTARIO BY
12Z SAT BEFORE MOVING TO JUST S OF JAMES BAY BY 00Z SUN. UPR MI WL
BE IMPACTED MAINLY BY THE WEAKER SRN DISTURBANCE. ALTHOUGH A BAND OF
RELATIVELY WEAK QVECTOR CNVGC IS FCST TO SLIDE ACROSS UPR MI ON FRI
NGT INTO SAT MRNG ON THE CYC SIDE OF THIS SRN SHRTWV...ACCOMPANYING
ISENTROPIC ASCENT/MSTR INFLOW IS FCST TO BE RELATIVELY WEAK. SO WL
FCST ONLY CHC POPS OVER MOST OF THE CWA AND MAINLY BTWN 03Z SAT AND
15-18Z SAT...WHEN THE FORCING ACCOMPANYING THE SRN SHRTWV AND A COLD
FNT ATTENDANT TO THE NRN SHRTWV ARE FCST TO EXIT THE ERN CWA AND
GIVE WAY TO SOME VIGOROUS DEEP LYR QVECTOR DVGC. MAINTAINED SOME
LIKELY POPS OVER THE NRN TIER OF THE CWA CLOSE TO THE STRONGER NRN
SHRTWV AND WHERE SHARPER LLVL CNVGC WL ACCOMPANY THE SAT COLD FROPA.
THE COLDEST 00Z GFS/12Z ECMWF RUNS SHOW H85 TEMPS IN THE WAKE OF THE
SAT COLD FROPA PLUNGING AS LO AS -25C BY 00Z SUN...BUT QUICK
TRANSITION TO A MORE DIFFLUENT/ACYC H925 N FLOW AND INVRN BASE
FALLING TO H85-875 WL TEND TO LIMIT LES INTENSITY. RELATIVELY
MODERATE TEMPS INTO SAT MRNG WL FALL THRU THE AFTN AS THE COLDER AIR
SURGES INTO THE AREA IN THE STEADY N FLOW AHEAD OF ARCTIC HI PRES
BLDG SEWD IN SCENTRAL CANADA.
SAT NGT THRU SUN NGT...UPR MI WL REMAIN DOMINATED BY A COLD N
BACKING WNW LLVL FLOW OF ARCTIC AIR ASSOCIATED WITH ARCTIC HI PRES
MOVING FM OVER ALBERTA/SASKATCHEWAN AT 00Z SUN INTO THE UPR MS RIVER
VALLEY BY 12Z MON. EXPECT TEMPS TO RUN WELL BLO NORMAL AND LES TO
CONTINUE NEAR LK SUP WITH H85 TEMPS FCST TO REMAIN NOT FAR FM -22C
TO -25C. SAT NGT COULD BE PARTICULARLY CHILLY OVER THE E WITH THE N
H925 FLOW ALLOWING SOME DRAINAGE OF COLD AIR INTO THAT AREA OFF
ONTARIO. ALTHOUGH FCST ACYC NATURE OF THE H925 FLOW AND NEAR ABSENCE
OF THE DGZ ASSOCIATED WITH THE VERY LO H85 TEMPS WL LIMIT LES
AMOUNTS...SOME OF THE MODELS HINT THERE MAY BE SOME ENHANCED CNVGC
ALONG A LK INDUCED TROF STRETCHING FM THE KEWEENAW TOWARD WHITEFISH
PT THAT WL INTENSIFY AS THE LARGER PRES GRADIENT RELAXES AND A
SHRTWV EMBEDDED IN THE NW FLOW APRCHS ON SUN/SUN NGT. RAISED POPS
WELL ABOVE THE CONSENSUS TO LIKELY ALONG THIS AXIS.
MON...LES ALONG THE LK INDUCED TROF WL BEGIN TO DIMINISH/SHIFT OUT
INTO LK SUP WITH THE APRCH OF A SFC RDG AXIS EXTENDING N FM THE HI
CENTER SHIFTING TOWARD THE OH VALLEY AND THE ASSOCIATED BACKING LLVL
FLOW. BUT THE MORE W WIND COMPONENT WL MEAN LESS LK MODERATION AND
PERSISTENT WELL BLO NORMAL SFC TEMPS EVEN AS THE H85 TEMPS MODERATE
A BIT FASTER.
TUE/WED...THE LONGER RANGE GUIDANCE HINTS ANOTHER CLIPPER TYPE
DISTURBANCE WL PASS THRU THE UPR LKS ON TUE...WITH H85 TEMPS
REBOUNDING TO NEAR -15C IN THE WAA BTWN THIS FEATURE AND HI PRES
MOVING INTO THE MID ATLANTIC. BUT ANOTHER ARCTIC SURGE LOOKS TO
FOLLOW ON WED AS THE SHRTWV PASSAGE REAMPLIFIES THE ERN TROF AND THE
NW FLOW IN ADVANCE OF THE NEXT CNDN HI SINKING INTO THE NRN PLAINS
ADVECTS H85 TEMPS AS LO AS -25 TO -28C INTO THE UPR LKS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 725 AM EST THU JAN 29 2015
GUSTY N-NNW WINDS ARE BEGINNING TO TAKE HOLD AT IWD AND
CMX...AND WILL PUSH INTO SAW OVER THE NEXT 2 HOURS. MUCH DRIER AIR
WORKING IN WILL BE WORKING AGAINST THE STRONG UPSLOPE WINDS
TODAY...AND WITH COLDER AIR PUSHING ACROSS LAKE SUPERIOR...EXPECT
NEARLY STEADY STATE CONDITIONS WITH MVFR CEILINGS. IFR CONDITIONS
MAY BE POSSIBLE IN SNOW AND BLOWING SNOW LATER THIS AFTERNOON AND
THIS EVENING AS AN UPPER LEVEL DISTURBANCE ENHANCES SNOW SHOWERS
BRIEFLY. OTHERWISE...LOOK FOR SLOWLY IMPROVING CONDITIONS TOWARDS
DAYBREAK FRIDAY AS WINDS RELAX TO AROUND 10KS OR LESS MORE OUT OF THE
NW AND LOW LEVEL MOISTURE DIMINISHES.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 355 AM EST THU JAN 29 2015
LOW PRESSURE SYSTEM NEAR N LAKE SUPERIOR THIS MORNING WILL MOVE INTO
QUEBEC THIS AFTERNOON WHILE ANOTHER LOW NEAR CHICAGO SHIFTS EAST
INTO NEW ENGLAND ON FRIDAY MORNING. MEANWHILE...A HIGH OVER S
CENTRAL CANADA WILL MOVE SE INTO MN ON FRIDAY. IN BETWEEN THE
EXITING LOW AND NEARING HIGH...STRONG N-NNW GALES GUSTING 35 TO
AROUND 40KTS WILL DEVELOP THIS AFTERNOON OVER MAINLY CENTRAL AND E
LAKE SUPERIOR. LOOK FOR WINDS TO SLOWLY DIMINISH LATE THIS EVENING
AND OVERNIGHT...WITH GUSTS REMAINING 25-30KTS THROUGH DAYBREAK
FRIDAY. GIVEN THE STRONG WINDS...AND COLDER AIR SURGING IN...HEAVY
FREEZING SPRAY WILL BE POSSIBLE OVER THIS SAME AREA INTO EARLY
FRIDAY MORNING. WINDS WILL THEN QUICKLY DIMINISH AND REMAIN LESS
THAN 30KTS THROUGH FRIDAY NIGHT.
AS THIS HIGH DRIFTS INTO THE OH RIVER VALLEY ON SATURDAY...A TROUGH
WILL SLIDE ACROSS THE UPPER GREAT LAKES. A FEW N TO NW GUSTS OF 30
TO NEAR 35KTS WILL BE POSSIBLE SATURDAY AFTERNOON AND EVENING.
EXPECT HIGH PRESSURE OVER CENTRAL CANADA ON SATURDAY TO MOVE SE INTO
THE N PLAINS ON SUNDAY...AND THE MID MS RIVER VALLEY ON MONDAY.
WINDS SHOULD DIMINISH FOR A TIME SUN BEFORE INCREASING AGAIN MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING FROM 1 PM THIS AFTERNOON TO 7 AM
EST FRIDAY FOR LSZ264-266-267.
GALE WARNING FROM 1 PM THIS AFTERNOON TO 4 AM EST FRIDAY FOR
LSZ267.
GALE WARNING UNTIL 4 AM EST FRIDAY FOR LSZ265-266.
GALE WARNING UNTIL 1 AM EST FRIDAY FOR LSZ263-264.
HEAVY FREEZING SPRAY WARNING FROM 1 PM THIS AFTERNOON TO 1 AM
EST FRIDAY FOR LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KF
LONG TERM...KC
AVIATION...KF
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
458 AM EST THU JAN 29 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 457 AM EST THU JAN 29 2015
WV AND LATEST RADAR IMAGERY SHOW IT WELL...THE DEEP MOISTURE SET UP
ACROSS CENTRAL UPPER MI IS QUICKLY EXITING E. THE SFC TROUGH SET UP
OVER W LAKE SUPERIOR AROUND 09Z THIS MORNING WILL EDGE TO THE E HALF
OF THE CWA SHORTLY AFTER DAYBREAK THIS IS WHEN WE WILL REALLY BEGIN
TO NOTICE SOME OF THOSE STRONGER N-NNW WINDS BEGIN /WINDS CURRENTLY
AROUND 12KTS AT CMX WILL BEGIN TO GUSTS 25-30KTS/.
-FZDZ HAS BEEN REPORTED OFF AND ON THIS MORNING AS THE MAIN BULK OF
MOISTURE EXISTS OVER CENTRAL AND E UPPER MI...AS STRONG HIGH
PRESSURE OVER CENTRAL SASKATCHEWAN NEARS. UTILIZED THE PROBABILITY
OF ICE PRESENT FROM THE RUC TO GET A BETTER HANDLE ON WHEN AND WHERE
-FZDZ MAY SET UP BEFORE COLD AIR PUSHES ACROSS ALL OF UPPER MI
/BASICALLY BY 18Z/ FOR ANY LINGERING MIXED PRECIP TO TRANSITION BACK
TO JUST -SHSN. LOOK FOR FALLING TEMPS THIS AFTERNOON AS THE COLDER
AIR SLIDES IN. 850MB TEMPS AROUND -10C EARLY THIS MORNING WILL FALL
THIS AFTERNOON...AND GET DOWN TO AROUND -17C BY 00Z...AND -20C BY
06Z FRIDAY. THE ARRIVAL OF THE COLDER AIR WILL BRING A BETTER CHANCE
OF LAKE EFFECT SNOW SHOWERS TO UPSLOPE LOCATIONS OVER THE W FAVORED
BY NNW WINDS.
LIMITING FACTORS FOR SIGNIFICANT SNOW ACCUMULATIONS OVER THE W THIRD
OF THE CWA LATER THIS AFTERNOON THROUGH THIS EVENING WILL BE THE
LOWERING DGZ TO AROUND 4KFT OR LESS BY 06Z FRIDAY...WINDS STILL
GUSTING 15-20KTS WILL KEEP SLR VALUES FROM RISING BACK UP TO
25:1 TOO FAST. HOWEVER...WITH THE 500MB TROUGH OVERHEAD AND AN
ADDITIONAL SHORTWAVE SLIDING THROUGH LATE THIS AFTERNOON THROUGH
THIS EVENING...SOME ENHANCEMENT IS EXPECTED. WILL KEEP SNOW AMOUNTS
AROUND 2IN OR LESS ACROSS THE W THIRD OF THE CWA.
ONE CONCERN FOR THE EVENING PERIOD WILL BE THE POTENTIAL OF A MESO
LOW SETTING UP OVER S CENTRAL LAKE SUPERIOR AFTER 03Z...KEEPING A
BAND OF MORE MODERATE SNOW OVER CENTRAL/E MARQUETTE COUNTY
AND W ALGER COUNTY. THE NAM AND REGIONAL WRF HIGHLIGHT THE
POTENTIAL. HAVE EXPANDED SNOW FARTHER W TO ACCOUNT FOR THIS...AS
WELL AS KEPT THE WINDS UP OVER S CENTRAL LAKE SUPERIOR A BIT LONGER
/WHICH SEEMS TO HAVE BEEN ALREADY ACCOUNTED FOR/. ENHANCED BY THE
WINDS GUSTING 25-35KTS...VISIBILITY RESTRICTIONS WILL BE A CONCERN
FOR THOSE TRAVELING ON M-28. EVEN WITHOUT ANY LAKE ENHANCEMENT
BLOWING AND DRIFTING SNOW COULD BE AN ISSUE...DEPENDING ON HOW SOLID
SNOW BANKS ON THE SIDE OF THE ROAD HAVE BECOME AND HOW MUCH SNOW HAS
BEEN ABLE TO ACCUMULATE ON THE ICE ALONG LAKE SUPERIOR.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 411 AM EST THU JAN 29 2015
FCST FOCUS IN THE MEDIUM AND EXTENDED RANGE WL BE ON THE IMPACT OF
SEVERAL CLIPPER TYPE SHRTWVS THAT ARE FCST TO MOVE THRU A MEAN UPR
TROF IN ERN NAMERICA. UNDER THE PERSISTENT NW FLOW ALOFT...EXPECT
BLO TO WELL BLO NORMAL TEMPS TO DOMINATE DURING THIS TIME WITH A
STEADY FEED OF CNDN AIR. WITH THE COLD AIR SURGES...LES WL BE AN
OBVIOUS CONCERN.
FRI...SFC HI PRES IS FCST TO SHIFT FM OVER MN TOWARD THE OH RIVER
VALLEY BE 00Z SAT. AS NW WINDS IN THE MRNG BACK TO THE W AND THEN
THE SW LATE...LINGERING LES OVER THE W WL BECOME CONFINED TO OVER
THE KEWEENAW AND END OVER THE E EXCEPT NEAR THE SHORE E OF GRAND
MARAIS TOWARD 00Z SAT. ALTHOUGH THE LK CLDS WL BE SHIFTING
OFFSHORE...MORE MID/HI CLDS IN ADVANCE OF ANOTHER SHRTWV MOVING SE
WITHIN THE NW FLOW ALF WL BE PUSHING INTO THE UPR LKS.
FRI NGT/SAT...SHRTWV EMBEDDED IN THE NW FLOW ALOFT WL BE MOVING INTO
NW MN AT 00Z SAT AND IS THEN FCST TO SLIDE SE THRU NCENTRAL WI BY
12Z SAT AND THEN ACROSS LOWER MI ON SAT. AT THE SAME TIME...ANOTHER
STRONGER SHRTWV WL BE MOVNG FM CENTRAL CANADA INTO FAR NW ONTARIO BY
12Z SAT BEFORE MOVING TO JUST S OF JAMES BAY BY 00Z SUN. UPR MI WL
BE IMPACTED MAINLY BY THE WEAKER SRN DISTURBANCE. ALTHOUGH A BAND OF
RELATIVELY WEAK QVECTOR CNVGC IS FCST TO SLIDE ACROSS UPR MI ON FRI
NGT INTO SAT MRNG ON THE CYC SIDE OF THIS SRN SHRTWV...ACCOMPANYING
ISENTROPIC ASCENT/MSTR INFLOW IS FCST TO BE RELATIVELY WEAK. SO WL
FCST ONLY CHC POPS OVER MOST OF THE CWA AND MAINLY BTWN 03Z SAT AND
15-18Z SAT...WHEN THE FORCING ACCOMPANYING THE SRN SHRTWV AND A COLD
FNT ATTENDANT TO THE NRN SHRTWV ARE FCST TO EXIT THE ERN CWA AND
GIVE WAY TO SOME VIGOROUS DEEP LYR QVECTOR DVGC. MAINTAINED SOME
LIKELY POPS OVER THE NRN TIER OF THE CWA CLOSE TO THE STRONGER NRN
SHRTWV AND WHERE SHARPER LLVL CNVGC WL ACCOMPANY THE SAT COLD FROPA.
THE COLDEST 00Z GFS/12Z ECMWF RUNS SHOW H85 TEMPS IN THE WAKE OF THE
SAT COLD FROPA PLUNGING AS LO AS -25C BY 00Z SUN...BUT QUICK
TRANSITION TO A MORE DIFFLUENT/ACYC H925 N FLOW AND INVRN BASE
FALLING TO H85-875 WL TEND TO LIMIT LES INTENSITY. RELATIVELY
MODERATE TEMPS INTO SAT MRNG WL FALL THRU THE AFTN AS THE COLDER AIR
SURGES INTO THE AREA IN THE STEADY N FLOW AHEAD OF ARCTIC HI PRES
BLDG SEWD IN SCENTRAL CANADA.
SAT NGT THRU SUN NGT...UPR MI WL REMAIN DOMINATED BY A COLD N
BACKING WNW LLVL FLOW OF ARCTIC AIR ASSOCIATED WITH ARCTIC HI PRES
MOVING FM OVER ALBERTA/SASKATCHEWAN AT 00Z SUN INTO THE UPR MS RIVER
VALLEY BY 12Z MON. EXPECT TEMPS TO RUN WELL BLO NORMAL AND LES TO
CONTINUE NEAR LK SUP WITH H85 TEMPS FCST TO REMAIN NOT FAR FM -22C
TO -25C. SAT NGT COULD BE PARTICULARLY CHILLY OVER THE E WITH THE N
H925 FLOW ALLOWING SOME DRAINAGE OF COLD AIR INTO THAT AREA OFF
ONTARIO. ALTHOUGH FCST ACYC NATURE OF THE H925 FLOW AND NEAR ABSENCE
OF THE DGZ ASSOCIATED WITH THE VERY LO H85 TEMPS WL LIMIT LES
AMOUNTS...SOME OF THE MODELS HINT THERE MAY BE SOME ENHANCED CNVGC
ALONG A LK INDUCED TROF STRETCHING FM THE KEWEENAW TOWARD WHITEFISH
PT THAT WL INTENSIFY AS THE LARGER PRES GRADIENT RELAXES AND A
SHRTWV EMBEDDED IN THE NW FLOW APRCHS ON SUN/SUN NGT. RAISED POPS
WELL ABOVE THE CONSENSUS TO LIKELY ALONG THIS AXIS.
MON...LES ALONG THE LK INDUCED TROF WL BEGIN TO DIMINISH/SHIFT OUT
INTO LK SUP WITH THE APRCH OF A SFC RDG AXIS EXTENDING N FM THE HI
CENTER SHIFTING TOWARD THE OH VALLEY AND THE ASSOCIATED BACKING LLVL
FLOW. BUT THE MORE W WIND COMPONENT WL MEAN LESS LK MODERATION AND
PERSISTENT WELL BLO NORMAL SFC TEMPS EVEN AS THE H85 TEMPS MODERATE
A BIT FASTER.
TUE/WED...THE LONGER RANGE GUIDANCE HINTS ANOTHER CLIPPER TYPE
DISTURBANCE WL PASS THRU THE UPR LKS ON TUE...WITH H85 TEMPS
REBOUNDING TO NEAR -15C IN THE WAA BTWN THIS FEATURE AND HI PRES
MOVING INTO THE MID ATLANTIC. BUT ANOTHER ARCTIC SURGE LOOKS TO
FOLLOW ON WED AS THE SHRTWV PASSAGE REAMPLIFIES THE ERN TROF AND THE
NW FLOW IN ADVANCE OF THE NEXT CNDN HI SINKING INTO THE NRN PLAINS
ADVECTS H85 TEMPS AS LO AS -25 TO -28C INTO THE UPR LKS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1154 PM EST WED JAN 28 2015
DISTURBANCE APPROACHING TONIGHT WILL BRING SOME -SN/DETERIORATING
CONDITIONS. ALL TERMINALS WILL LIKELY FALL TO IFR WITH A FEW HRS OF
LIFR POSSIBLE OVERNIGHT. THERE MAY BE A LITTLE
-FZDZ LATE TONIGHT AT KIWD. PASSAGE OF COLD FRONT
EARLY THU MORNING WILL BRING INCREASING...GUSTY NW
WINDS...ESPECIALLY AT THE MORE EXPOSED KCMX TERMINAL.
OTHERWISE...EXPECT IMPROVEMENT TO MVFR AT ALL TERMINALS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 355 AM EST THU JAN 29 2015
LOW PRESSURE SYSTEM NEAR N LAKE SUPERIOR THIS MORNING WILL MOVE INTO
QUEBEC THIS AFTERNOON WHILE ANOTHER LOW NEAR CHICAGO SHIFTS EAST
INTO NEW ENGLAND ON FRIDAY MORNING. MEANWHILE...A HIGH OVER S
CENTRAL CANADA WILL MOVE SE INTO MN ON FRIDAY. IN BETWEEN THE
EXITING LOW AND NEARING HIGH...STRONG N-NNW GALES GUSTING 35 TO
AROUND 40KTS WILL DEVELOP THIS AFTERNOON OVER MAINLY CENTRAL AND E
LAKE SUPERIOR. LOOK FOR WINDS TO SLOWLY DIMINISH LATE THIS EVENING
AND OVERNIGHT...WITH GUSTS REMAINING 25-30KTS THROUGH DAYBREAK
FRIDAY. GIVEN THE STRONG WINDS...AND COLDER AIR SURGING IN...HEAVY
FREEZING SPRAY WILL BE POSSIBLE OVER THIS SAME AREA INTO EARLY
FRIDAY MORNING. WINDS WILL THEN QUICKLY DIMINISH AND REMAIN LESS
THAN 30KTS THROUGH FRIDAY NIGHT.
AS THIS HIGH DRIFTS INTO THE OH RIVER VALLEY ON SATURDAY...A TROUGH
WILL SLIDE ACROSS THE UPPER GREAT LAKES. A FEW N TO NW GUSTS OF 30
TO NEAR 35KTS WILL BE POSSIBLE SATURDAY AFTERNOON AND EVENING.
EXPECT HIGH PRESSURE OVER CENTRAL CANADA ON SATURDAY TO MOVE SE INTO
THE N PLAINS ON SUNDAY...AND THE MID MS RIVER VALLEY ON MONDAY.
WINDS SHOULD DIMINISH FOR A TIME SUN BEFORE INCREASING AGAIN MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING FROM 1 PM THIS AFTERNOON TO 7 AM
EST FRIDAY FOR LSZ264-266-267.
GALE WARNING FROM 1 PM THIS AFTERNOON TO 4 AM EST FRIDAY FOR
LSZ267.
GALE WARNING FROM 10 AM THIS MORNING TO 4 AM EST FRIDAY FOR
LSZ265-266.
GALE WARNING UNTIL 1 AM EST FRIDAY FOR LSZ263-264.
HEAVY FREEZING SPRAY WARNING FROM 1 PM THIS AFTERNOON TO 1 AM
EST FRIDAY FOR LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KF
LONG TERM...KC
AVIATION...07
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
412 AM EST THU JAN 29 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 444 PM EST WED JAN 28 2015
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A PAIR OF SHORTWAVES TO
THE W AND NW. ONE IS MOVING OUT OF WY/CO INTO THE WRN PLAINS AND THE
OTHER IS MOVING FROM SRN SASKATCHEWAN INTO SRN MANITOBA. AHEAD OF
THESE FEATURES...A RIBBON OF STRENGTHENING WAA/ISENTROPIC ASCENT IS
SPREADING ESE ACROSS NRN ONTARIO AND THE UPPER GREAT LAKES
UNDERNEATH RIGHT ENTRANCE OF UPPER JET CURVING FROM NRN ONTARIO DOWN
THRU THE CNTRL APPALACHIANS. REGIONAL RADARS SHOW A STREAK OF RADAR
RETURNS EXTENDING ESE FROM SE MANITOBA ACROSS ADJACENT NRN ONTARIO
AND OVER LAKE SUPERIOR/ERN UPPER MI. THE ASCENT HAS BEEN SUFFICIENT
TO ERODE DRY AIR AT THE LOWER LEVELS AND ALLOW SOME -SN TO REACH THE
GROUND FROM THE TIP OF THE KEWEENAW INTO THE NCNTRL AND ERN FCST
AREA.
PAIR OF SHORTWAVES WILL CONTINUE MOVING ESE TONIGHT WITH THE NRN
STREAM WAVE THE MORE IMPORTANT FEATURE FOR THE WEATHER HERE. AS THE
WAVE APPROACHES...ISENTROPIC ASCENT ON THE 295K SFC INCREASES
TONIGHT...MOST NOTABLY OVER THE E HALF OF UPPER MI. WHILE IT WILL BE
TOO WARM FOR ANY LAKE ENHANCEMENT OFF LAKE MICHIGAN...THE FLOW OFF
THE LAKE WILL STILL AID THE MOISTENING OF THE LOW LEVELS. OVER THE
W...THE WINDOW OF COLUMN MOISTENING IS SHORTER BEFORE THE ISENTROPIC
ASCENT DEPARTS OVERNIGHT. THUS...PCPN AMOUNTS TONIGHT WILL BE
LIGHTEST OVER THE W AND GREATER OVER THE E. 295K SFC SHOWS MIXING
RATIOS OF 3-4G/KG AVBL...SUGGESTING THE POTENTIAL FOR 3-4INCHES OF
SNOW FOR THE ROUGHLY 6HRS OF ASCENT EXPECTED. 4 INCHES IS LIKELY TOO
HIGH SINCE SNOW TO WATER RATIOS SHOULD BE ON THE LOWER SIDE. AS IT
IS...WILL PROBABLY BE CLOSE TO ADVY THRESHOLD OVER THE FAR E...
MAINLY LUCE COUNTY...AS 12HR SNOW ACCUMULATIONS FROM LATE EVENING TO
LATE THU MORNING WILL BE NEAR 3 INCHES. SNOW ACCUMULATIONS WILL BE
STEADILY LIGHTER TO THE W...DOWN TO LESS THAN 1 INCH FAR W AND ALONG
THE WI BORDER. LATE TONIGHT INTO THU MORNING...FCST SOUNDINGS
SUPPORT THE POTENTIAL FOR SOME -FZDZ AS MID LEVEL MOISTURE/SYNOPTIC
SNOW EXIT...LEAVING A LOW LEVEL MOIST LAYER THAT HAS TEMPS HIGHER
THAN -10C. WILL INCLUDE MENTION OF -FZDZ WHERE WINDS WILL BE
UPSLOPING.
COLD FRONT PASSES ACROSS UPPER MI THU MORNING. DESPITE INCREASING
WIND FIELDS...INITIAL CAA IS WEAK AS THERMAL GRADIENT IS DISPLACED
OFF TO THE NW...BUT CAA INCREASES QUICKLY IN THE AFTN. 850MB TEMPS
AROUND -10C IN THE MORNING WILL FALL TO NEAR -20C BY 00Z FRI...AND
THIS WILL RESULT IN FALLING SFC TEMPS...ESPECIALLY IN THE AFTN. LAST
OF THE SYNOPTIC SNOW WILL END OVER THE E IN THE MORNING.
OTHERWISE...THERE MAY NOT BE TOO MUCH IN THE WAY OF PCPN (-SN/-FZDZ)
DURING THE MORNING AWAY FROM AREAS THAT SEE UPSLOPING UNDER NW
WINDS. AS COLDER AIR ARRIVES IN THE AFTN...NW/NNW FLOW LES WILL
INCREASE IN COVERAGE WITH DGZ DROPPING INTO THE CONVECTIVE LAYER.
STRONG SUBSIDENCE/DEEP LAYER QVECTOR DIVERGENCE WILL LIMIT LES
INTENSITY. SO FOR THE MOST PART...EXPECT ACCUMULATIONS MOSTLY AROUND
1 INCH IN THE AFTN. STRONG WINDS WILL DISPLACE LES A LITTLE FARTHER
INLAND THAN NORMAL. SPEAKING OF WINDS...FAVORABLE POSTIONING OF PRES
RISE/FALL COUPLET WILL RESULT IN AN ADDITIVE ISALLOBARIC WIND
COMPONENT. COMBINED WITH 925MB WINDS INCREASING TO AROUND
40KT...CONDITIONS WILL BECOME BLUSTERY ACROSS THE AREA. ALONG THE
LAKE SUPERIOR SHORE AROUND THE TIP OF THE KEWEENAW AND FROM BIG BAY
EASTWARD...WINDS WILL PROBABLY GUST TO 35 TO 45 MPH IN THE AFTN.
DEPENDING ON HOW QUICKLY LES INCREASES IN THE AFTN...BLSN COULD
BECOME A SIGNIFICANT ISSUE NEAR THE LAKE.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 411 AM EST THU JAN 29 2015
FCST FOCUS IN THE MEDIUM AND EXTENDED RANGE WL BE ON THE IMPACT OF
SEVERAL CLIPPER TYPE SHRTWVS THAT ARE FCST TO MOVE THRU A MEAN UPR
TROF IN ERN NAMERICA. UNDER THE PERSISTENT NW FLOW ALOFT...EXPECT
BLO TO WELL BLO NORMAL TEMPS TO DOMINATE DURING THIS TIME WITH A
STEADY FEED OF CNDN AIR. WITH THE COLD AIR SURGES...LES WL BE AN
OBVIOUS CONCERN.
FRI...SFC HI PRES IS FCST TO SHIFT FM OVER MN TOWARD THE OH RIVER
VALLEY BE 00Z SAT. AS NW WINDS IN THE MRNG BACK TO THE W AND THEN
THE SW LATE...LINGERING LES OVER THE W WL BECOME CONFINED TO OVER
THE KEWEENAW AND END OVER THE E EXCEPT NEAR THE SHORE E OF GRAND
MARAIS TOWARD 00Z SAT. ALTHOUGH THE LK CLDS WL BE SHIFTING
OFFSHORE...MORE MID/HI CLDS IN ADVANCE OF ANOTHER SHRTWV MOVING SE
WITHIN THE NW FLOW ALF WL BE PUSHING INTO THE UPR LKS.
FRI NGT/SAT...SHRTWV EMBEDDED IN THE NW FLOW ALOFT WL BE MOVING INTO
NW MN AT 00Z SAT AND IS THEN FCST TO SLIDE SE THRU NCENTRAL WI BY
12Z SAT AND THEN ACROSS LOWER MI ON SAT. AT THE SAME TIME...ANOTHER
STRONGER SHRTWV WL BE MOVNG FM CENTRAL CANADA INTO FAR NW ONTARIO BY
12Z SAT BEFORE MOVING TO JUST S OF JAMES BAY BY 00Z SUN. UPR MI WL
BE IMPACTED MAINLY BY THE WEAKER SRN DISTURBANCE. ALTHOUGH A BAND OF
RELATIVELY WEAK QVECTOR CNVGC IS FCST TO SLIDE ACROSS UPR MI ON FRI
NGT INTO SAT MRNG ON THE CYC SIDE OF THIS SRN SHRTWV...ACCOMPANYING
ISENTROPIC ASCENT/MSTR INFLOW IS FCST TO BE RELATIVELY WEAK. SO WL
FCST ONLY CHC POPS OVER MOST OF THE CWA AND MAINLY BTWN 03Z SAT AND
15-18Z SAT...WHEN THE FORCING ACCOMPANYING THE SRN SHRTWV AND A COLD
FNT ATTENDANT TO THE NRN SHRTWV ARE FCST TO EXIT THE ERN CWA AND
GIVE WAY TO SOME VIGOROUS DEEP LYR QVECTOR DVGC. MAINTAINED SOME
LIKELY POPS OVER THE NRN TIER OF THE CWA CLOSE TO THE STRONGER NRN
SHRTWV AND WHERE SHARPER LLVL CNVGC WL ACCOMPANY THE SAT COLD FROPA.
THE COLDEST 00Z GFS/12Z ECMWF RUNS SHOW H85 TEMPS IN THE WAKE OF THE
SAT COLD FROPA PLUNGING AS LO AS -25C BY 00Z SUN...BUT QUICK
TRANSITION TO A MORE DIFFLUENT/ACYC H925 N FLOW AND INVRN BASE
FALLING TO H85-875 WL TEND TO LIMIT LES INTENSITY. RELATIVELY
MODERATE TEMPS INTO SAT MRNG WL FALL THRU THE AFTN AS THE COLDER AIR
SURGES INTO THE AREA IN THE STEADY N FLOW AHEAD OF ARCTIC HI PRES
BLDG SEWD IN SCENTRAL CANADA.
SAT NGT THRU SUN NGT...UPR MI WL REMAIN DOMINATED BY A COLD N
BACKING WNW LLVL FLOW OF ARCTIC AIR ASSOCIATED WITH ARCTIC HI PRES
MOVING FM OVER ALBERTA/SASKATCHEWAN AT 00Z SUN INTO THE UPR MS RIVER
VALLEY BY 12Z MON. EXPECT TEMPS TO RUN WELL BLO NORMAL AND LES TO
CONTINUE NEAR LK SUP WITH H85 TEMPS FCST TO REMAIN NOT FAR FM -22C
TO -25C. SAT NGT COULD BE PARTICULARLY CHILLY OVER THE E WITH THE N
H925 FLOW ALLOWING SOME DRAINAGE OF COLD AIR INTO THAT AREA OFF
ONTARIO. ALTHOUGH FCST ACYC NATURE OF THE H925 FLOW AND NEAR ABSENCE
OF THE DGZ ASSOCIATED WITH THE VERY LO H85 TEMPS WL LIMIT LES
AMOUNTS...SOME OF THE MODELS HINT THERE MAY BE SOME ENHANCED CNVGC
ALONG A LK INDUCED TROF STRETCHING FM THE KEWEENAW TOWARD WHITEFISH
PT THAT WL INTENSIFY AS THE LARGER PRES GRADIENT RELAXES AND A
SHRTWV EMBEDDED IN THE NW FLOW APRCHS ON SUN/SUN NGT. RAISED POPS
WELL ABOVE THE CONSENSUS TO LIKELY ALONG THIS AXIS.
MON...LES ALONG THE LK INDUCED TROF WL BEGIN TO DIMINISH/SHIFT OUT
INTO LK SUP WITH THE APRCH OF A SFC RDG AXIS EXTENDING N FM THE HI
CENTER SHIFTING TOWARD THE OH VALLEY AND THE ASSOCIATED BACKING LLVL
FLOW. BUT THE MORE W WIND COMPONENT WL MEAN LESS LK MODERATION AND
PERSISTENT WELL BLO NORMAL SFC TEMPS EVEN AS THE H85 TEMPS MODERATE
A BIT FASTER.
TUE/WED...THE LONGER RANGE GUIDANCE HINTS ANOTHER CLIPPER TYPE
DISTURBANCE WL PASS THRU THE UPR LKS ON TUE...WITH H85 TEMPS
REBOUNDING TO NEAR -15C IN THE WAA BTWN THIS FEATURE AND HI PRES
MOVING INTO THE MID ATLANTIC. BUT ANOTHER ARCTIC SURGE LOOKS TO
FOLLOW ON WED AS THE SHRTWV PASSAGE REAMPLIFIES THE ERN TROF AND THE
NW FLOW IN ADVANCE OF THE NEXT CNDN HI SINKING INTO THE NRN PLAINS
ADVECTS H85 TEMPS AS LO AS -25 TO -28C INTO THE UPR LKS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1154 PM EST WED JAN 28 2015
DISTURBANCE APPROACHING TONIGHT WILL BRING SOME -SN/DETERIORATING
CONDITIONS. ALL TERMINALS WILL LIKELY FALL TO IFR WITH A FEW HRS OF
LIFR POSSIBLE OVERNIGHT. THERE MAY BE A LITTLE
-FZDZ LATE TONIGHT AT KIWD. PASSAGE OF COLD FRONT
EARLY THU MORNING WILL BRING INCREASING...GUSTY NW
WINDS...ESPECIALLY AT THE MORE EXPOSED KCMX TERMINAL.
OTHERWISE...EXPECT IMPROVEMENT TO MVFR AT ALL TERMINALS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 355 AM EST THU JAN 29 2015
LOW PRESSURE SYSTEM NEAR N LAKE SUPERIOR THIS MORNING WILL MOVE INTO
QUEBEC THIS AFTERNOON WHILE ANOTHER LOW NEAR CHICAGO SHIFTS EAST
INTO NEW ENGLAND ON FRIDAY MORNING. MEANWHILE...A HIGH OVER S
CENTRAL CANADA WILL MOVE SE INTO MN ON FRIDAY. IN BETWEEN THE
EXITING LOW AND NEARING HIGH...STRONG N-NNW GALES GUSTING 35 TO
AROUND 40KTS WILL DEVELOP THIS AFTERNOON OVER MAINLY CENTRAL AND E
LAKE SUPERIOR. LOOK FOR WINDS TO SLOWLY DIMINISH LATE THIS EVENING
AND OVERNIGHT...WITH GUSTS REMAINING 25-30KTS THROUGH DAYBREAK
FRIDAY. GIVEN THE STRONG WINDS...AND COLDER AIR SURGING IN...HEAVY
FREEZING SPRAY WILL BE POSSIBLE OVER THIS SAME AREA INTO EARLY
FRIDAY MORNING. WINDS WILL THEN QUICKLY DIMINISH AND REMAIN LESS
THAN 30KTS THROUGH FRIDAY NIGHT.
AS THIS HIGH DRIFTS INTO THE OH RIVER VALLEY ON SATURDAY...A TROUGH
WILL SLIDE ACROSS THE UPPER GREAT LAKES. A FEW N TO NW GUSTS OF 30
TO NEAR 35KTS WILL BE POSSIBLE SATURDAY AFTERNOON AND EVENING.
EXPECT HIGH PRESSURE OVER CENTRAL CANADA ON SATURDAY TO MOVE SE INTO
THE N PLAINS ON SUNDAY...AND THE MID MS RIVER VALLEY ON MONDAY.
WINDS SHOULD DIMINISH FOR A TIME SUN BEFORE INCREASING AGAIN MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING FROM 1 PM THIS AFTERNOON TO 7 AM
EST FRIDAY FOR LSZ264-266-267.
GALE WARNING FROM 1 PM THIS AFTERNOON TO 4 AM EST FRIDAY FOR
LSZ267.
GALE WARNING FROM 10 AM THIS MORNING TO 4 AM EST FRIDAY FOR
LSZ265-266.
GALE WARNING UNTIL 1 AM EST FRIDAY FOR LSZ263-264.
HEAVY FREEZING SPRAY WARNING FROM 1 PM THIS AFTERNOON TO 1 AM
EST FRIDAY FOR LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KC
AVIATION...07
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
355 AM EST THU JAN 29 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 444 PM EST WED JAN 28 2015
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A PAIR OF SHORTWAVES TO
THE W AND NW. ONE IS MOVING OUT OF WY/CO INTO THE WRN PLAINS AND THE
OTHER IS MOVING FROM SRN SASKATCHEWAN INTO SRN MANITOBA. AHEAD OF
THESE FEATURES...A RIBBON OF STRENGTHENING WAA/ISENTROPIC ASCENT IS
SPREADING ESE ACROSS NRN ONTARIO AND THE UPPER GREAT LAKES
UNDERNEATH RIGHT ENTRANCE OF UPPER JET CURVING FROM NRN ONTARIO DOWN
THRU THE CNTRL APPALACHIANS. REGIONAL RADARS SHOW A STREAK OF RADAR
RETURNS EXTENDING ESE FROM SE MANITOBA ACROSS ADJACENT NRN ONTARIO
AND OVER LAKE SUPERIOR/ERN UPPER MI. THE ASCENT HAS BEEN SUFFICIENT
TO ERODE DRY AIR AT THE LOWER LEVELS AND ALLOW SOME -SN TO REACH THE
GROUND FROM THE TIP OF THE KEWEENAW INTO THE NCNTRL AND ERN FCST
AREA.
PAIR OF SHORTWAVES WILL CONTINUE MOVING ESE TONIGHT WITH THE NRN
STREAM WAVE THE MORE IMPORTANT FEATURE FOR THE WEATHER HERE. AS THE
WAVE APPROACHES...ISENTROPIC ASCENT ON THE 295K SFC INCREASES
TONIGHT...MOST NOTABLY OVER THE E HALF OF UPPER MI. WHILE IT WILL BE
TOO WARM FOR ANY LAKE ENHANCEMENT OFF LAKE MICHIGAN...THE FLOW OFF
THE LAKE WILL STILL AID THE MOISTENING OF THE LOW LEVELS. OVER THE
W...THE WINDOW OF COLUMN MOISTENING IS SHORTER BEFORE THE ISENTROPIC
ASCENT DEPARTS OVERNIGHT. THUS...PCPN AMOUNTS TONIGHT WILL BE
LIGHTEST OVER THE W AND GREATER OVER THE E. 295K SFC SHOWS MIXING
RATIOS OF 3-4G/KG AVBL...SUGGESTING THE POTENTIAL FOR 3-4INCHES OF
SNOW FOR THE ROUGHLY 6HRS OF ASCENT EXPECTED. 4 INCHES IS LIKELY TOO
HIGH SINCE SNOW TO WATER RATIOS SHOULD BE ON THE LOWER SIDE. AS IT
IS...WILL PROBABLY BE CLOSE TO ADVY THRESHOLD OVER THE FAR E...
MAINLY LUCE COUNTY...AS 12HR SNOW ACCUMULATIONS FROM LATE EVENING TO
LATE THU MORNING WILL BE NEAR 3 INCHES. SNOW ACCUMULATIONS WILL BE
STEADILY LIGHTER TO THE W...DOWN TO LESS THAN 1 INCH FAR W AND ALONG
THE WI BORDER. LATE TONIGHT INTO THU MORNING...FCST SOUNDINGS
SUPPORT THE POTENTIAL FOR SOME -FZDZ AS MID LEVEL MOISTURE/SYNOPTIC
SNOW EXIT...LEAVING A LOW LEVEL MOIST LAYER THAT HAS TEMPS HIGHER
THAN -10C. WILL INCLUDE MENTION OF -FZDZ WHERE WINDS WILL BE
UPSLOPING.
COLD FRONT PASSES ACROSS UPPER MI THU MORNING. DESPITE INCREASING
WIND FIELDS...INITIAL CAA IS WEAK AS THERMAL GRADIENT IS DISPLACED
OFF TO THE NW...BUT CAA INCREASES QUICKLY IN THE AFTN. 850MB TEMPS
AROUND -10C IN THE MORNING WILL FALL TO NEAR -20C BY 00Z FRI...AND
THIS WILL RESULT IN FALLING SFC TEMPS...ESPECIALLY IN THE AFTN. LAST
OF THE SYNOPTIC SNOW WILL END OVER THE E IN THE MORNING.
OTHERWISE...THERE MAY NOT BE TOO MUCH IN THE WAY OF PCPN (-SN/-FZDZ)
DURING THE MORNING AWAY FROM AREAS THAT SEE UPSLOPING UNDER NW
WINDS. AS COLDER AIR ARRIVES IN THE AFTN...NW/NNW FLOW LES WILL
INCREASE IN COVERAGE WITH DGZ DROPPING INTO THE CONVECTIVE LAYER.
STRONG SUBSIDENCE/DEEP LAYER QVECTOR DIVERGENCE WILL LIMIT LES
INTENSITY. SO FOR THE MOST PART...EXPECT ACCUMULATIONS MOSTLY AROUND
1 INCH IN THE AFTN. STRONG WINDS WILL DISPLACE LES A LITTLE FARTHER
INLAND THAN NORMAL. SPEAKING OF WINDS...FAVORABLE POSTIONING OF PRES
RISE/FALL COUPLET WILL RESULT IN AN ADDITIVE ISALLOBARIC WIND
COMPONENT. COMBINED WITH 925MB WINDS INCREASING TO AROUND
40KT...CONDITIONS WILL BECOME BLUSTERY ACROSS THE AREA. ALONG THE
LAKE SUPERIOR SHORE AROUND THE TIP OF THE KEWEENAW AND FROM BIG BAY
EASTWARD...WINDS WILL PROBABLY GUST TO 35 TO 45 MPH IN THE AFTN.
DEPENDING ON HOW QUICKLY LES INCREASES IN THE AFTN...BLSN COULD
BECOME A SIGNIFICANT ISSUE NEAR THE LAKE.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 327 PM EST WED JAN 28 2015
A SHORTWAVE TROUGH WILL BE OVER THE CWA AT 00Z FRI...WITH MOST OF
THE ASSOCIATED FORCING E OF THE CWA BY THAT TIME. NW-NNW LOW LEVEL
WINDS AND 850MB TEMPS AS LOW AS -22C WILL KEEP SNOW GOING IN THE NW-
NNW WINDS SNOWBELTS THU NIGHT...BUT A SFC RIDGE PUSHING THROUGH ON
FRI WILL LEAD TO A DIMINISHING TREND IN THE LES AS WINDS BECOME ANTI-
CYCLONIC. WINDS TURN SWLY BY FRI NIGHT BEHIND THE TROUGH AND AHEAD
OF A CLIPPER SHORTWAVE/SFC TROUGH THAT WILL MOVE THROUGH LATE FRI
NIGHT/EARLY SAT. NW WIND LES WILL RAMP UP ALONG AND BEHIND THE
TROUGH AS 850MB WINDS AS LOW AS -30C SWEEP ACROSS THE AREA. TEMPS
LOOK TO MODERATE SOME MON INTO TUE AS A RIDGE MOVES THROUGH...WITH
ANOTHER COLD BLAST SHOWN BY MODELS TOWARD THE MIDDLE OF NEXT WEEK.
OVER THE NEXT WEEK THE NW WINDS SNOWBELTS MAINLY E OF MARQUETTE WILL
SEE THE MOST SNOWFALL...WITH PROLONGED LIGHT TO MODERATE SNOWFALL.
WITH THE VERY COLD AIRMASS... GROWTH WILL BE ADVERSELY
IMPACTED...WITH SMALL SNOW FLAKES EFFICIENT AT REDUCING VIS THE
PREDOMINANT CONDITION.
COLD TEMPS ARE A CERTAINTY...ESPECIALLY SUN AND MON WHEN HIGHS WILL
NOT MAKE IT OUT OF THE SINGLE DIGITS ABOVE ZERO IN MOST LOCATIONS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1154 PM EST WED JAN 28 2015
DISTURBANCE APPROACHING TONIGHT WILL BRING SOME -SN/DETERIORATING
CONDITIONS. ALL TERMINALS WILL LIKELY FALL TO IFR WITH A FEW HRS OF
LIFR POSSIBLE OVERNIGHT. THERE MAY BE A LITTLE
-FZDZ LATE TONIGHT AT KIWD. PASSAGE OF COLD FRONT
EARLY THU MORNING WILL BRING INCREASING...GUSTY NW
WINDS...ESPECIALLY AT THE MORE EXPOSED KCMX TERMINAL.
OTHERWISE...EXPECT IMPROVEMENT TO MVFR AT ALL TERMINALS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 355 AM EST THU JAN 29 2015
LOW PRESSURE SYSTEM NEAR N LAKE SUPERIOR THIS MORNING WILL MOVE INTO
QUEBEC THIS AFTERNOON WHILE ANOTHER LOW NEAR CHICAGO SHIFTS EAST
INTO NEW ENGLAND ON FRIDAY MORNING. MEANWHILE...A HIGH OVER S
CENTRAL CANADA WILL MOVE SE INTO MN ON FRIDAY. IN BETWEEN THE
EXITING LOW AND NEARING HIGH...STRONG N-NNW GALES GUSTING 35 TO
AROUND 40KTS WILL DEVELOP THIS AFTERNOON OVER MAINLY CENTRAL AND E
LAKE SUPERIOR. LOOK FOR WINDS TO SLOWLY DIMINISH LATE THIS EVENING
AND OVERNIGHT...WITH GUSTS REMAINING 25-30KTS THROUGH DAYBREAK
FRIDAY. GIVEN THE STRONG WINDS...AND COLDER AIR SURGING IN...HEAVY
FREEZING SPRAY WILL BE POSSIBLE OVER THIS SAME AREA INTO EARLY
FRIDAY MORNING. WINDS WILL THEN QUICKLY DIMINISH AND REMAIN LESS
THAN 30KTS THROUGH FRIDAY NIGHT.
AS THIS HIGH DRIFTS INTO THE OH RIVER VALLEY ON SATURDAY...A TROUGH
WILL SLIDE ACROSS THE UPPER GREAT LAKES. A FEW N TO NW GUSTS OF 30
TO NEAR 35KTS WILL BE POSSIBLE SATURDAY AFTERNOON AND EVENING.
EXPECT HIGH PRESSURE OVER CENTRAL CANADA ON SATURDAY TO MOVE SE INTO
THE N PLAINS ON SUNDAY...AND THE MID MS RIVER VALLEY ON MONDAY.
WINDS SHOULD DIMINISH FOR A TIME SUN BEFORE INCREASING AGAIN MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING FROM 1 PM THIS AFTERNOON TO 7 AM
EST FRIDAY FOR LSZ264-266-267.
GALE WARNING FROM 1 PM THIS AFTERNOON TO 4 AM EST FRIDAY FOR
LSZ267.
GALE WARNING FROM 10 AM THIS MORNING TO 4 AM EST FRIDAY FOR
LSZ265-266.
GALE WARNING FROM 7 AM THIS MORNING TO 1 AM EST FRIDAY FOR
LSZ263-264.
HEAVY FREEZING SPRAY WARNING FROM 1 PM THIS AFTERNOON TO 1 AM
EST FRIDAY FOR LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...07
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1154 PM EST WED JAN 28 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 444 PM EST WED JAN 28 2015
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A PAIR OF SHORTWAVES TO
THE W AND NW. ONE IS MOVING OUT OF WY/CO INTO THE WRN PLAINS AND THE
OTHER IS MOVING FROM SRN SASKATCHEWAN INTO SRN MANITOBA. AHEAD OF
THESE FEATURES...A RIBBON OF STRENGTHENING WAA/ISENTROPIC ASCENT IS
SPREADING ESE ACROSS NRN ONTARIO AND THE UPPER GREAT LAKES
UNDERNEATH RIGHT ENTRANCE OF UPPER JET CURVING FROM NRN ONTARIO DOWN
THRU THE CNTRL APPALACHIANS. REGIONAL RADARS SHOW A STREAK OF RADAR
RETURNS EXTENDING ESE FROM SE MANITOBA ACROSS ADJACENT NRN ONTARIO
AND OVER LAKE SUPERIOR/ERN UPPER MI. THE ASCENT HAS BEEN SUFFICIENT
TO ERODE DRY AIR AT THE LOWER LEVELS AND ALLOW SOME -SN TO REACH THE
GROUND FROM THE TIP OF THE KEWEENAW INTO THE NCNTRL AND ERN FCST
AREA.
PAIR OF SHORTWAVES WILL CONTINUE MOVING ESE TONIGHT WITH THE NRN
STREAM WAVE THE MORE IMPORTANT FEATURE FOR THE WEATHER HERE. AS THE
WAVE APPROACHES...ISENTROPIC ASCENT ON THE 295K SFC INCREASES
TONIGHT...MOST NOTABLY OVER THE E HALF OF UPPER MI. WHILE IT WILL BE
TOO WARM FOR ANY LAKE ENHANCEMENT OFF LAKE MICHIGAN...THE FLOW OFF
THE LAKE WILL STILL AID THE MOISTENING OF THE LOW LEVELS. OVER THE
W...THE WINDOW OF COLUMN MOISTENING IS SHORTER BEFORE THE ISENTROPIC
ASCENT DEPARTS OVERNIGHT. THUS...PCPN AMOUNTS TONIGHT WILL BE
LIGHTEST OVER THE W AND GREATER OVER THE E. 295K SFC SHOWS MIXING
RATIOS OF 3-4G/KG AVBL...SUGGESTING THE POTENTIAL FOR 3-4INCHES OF
SNOW FOR THE ROUGHLY 6HRS OF ASCENT EXPECTED. 4 INCHES IS LIKELY TOO
HIGH SINCE SNOW TO WATER RATIOS SHOULD BE ON THE LOWER SIDE. AS IT
IS...WILL PROBABLY BE CLOSE TO ADVY THRESHOLD OVER THE FAR E...
MAINLY LUCE COUNTY...AS 12HR SNOW ACCUMULATIONS FROM LATE EVENING TO
LATE THU MORNING WILL BE NEAR 3 INCHES. SNOW ACCUMULATIONS WILL BE
STEADILY LIGHTER TO THE W...DOWN TO LESS THAN 1 INCH FAR W AND ALONG
THE WI BORDER. LATE TONIGHT INTO THU MORNING...FCST SOUNDINGS
SUPPORT THE POTENTIAL FOR SOME -FZDZ AS MID LEVEL MOISTURE/SYNOPTIC
SNOW EXIT...LEAVING A LOW LEVEL MOIST LAYER THAT HAS TEMPS HIGHER
THAN -10C. WILL INCLUDE MENTION OF -FZDZ WHERE WINDS WILL BE
UPSLOPING.
COLD FRONT PASSES ACROSS UPPER MI THU MORNING. DESPITE INCREASING
WIND FIELDS...INITIAL CAA IS WEAK AS THERMAL GRADIENT IS DISPLACED
OFF TO THE NW...BUT CAA INCREASES QUICKLY IN THE AFTN. 850MB TEMPS
AROUND -10C IN THE MORNING WILL FALL TO NEAR -20C BY 00Z FRI...AND
THIS WILL RESULT IN FALLING SFC TEMPS...ESPECIALLY IN THE AFTN. LAST
OF THE SYNOPTIC SNOW WILL END OVER THE E IN THE MORNING.
OTHERWISE...THERE MAY NOT BE TOO MUCH IN THE WAY OF PCPN (-SN/-FZDZ)
DURING THE MORNING AWAY FROM AREAS THAT SEE UPSLOPING UNDER NW
WINDS. AS COLDER AIR ARRIVES IN THE AFTN...NW/NNW FLOW LES WILL
INCREASE IN COVERAGE WITH DGZ DROPPING INTO THE CONVECTIVE LAYER.
STRONG SUBSIDENCE/DEEP LAYER QVECTOR DIVERGENCE WILL LIMIT LES
INTENSITY. SO FOR THE MOST PART...EXPECT ACCUMULATIONS MOSTLY AROUND
1 INCH IN THE AFTN. STRONG WINDS WILL DISPLACE LES A LITTLE FARTHER
INLAND THAN NORMAL. SPEAKING OF WINDS...FAVORABLE POSTIONING OF PRES
RISE/FALL COUPLET WILL RESULT IN AN ADDITIVE ISALLOBARIC WIND
COMPONENT. COMBINED WITH 925MB WINDS INCREASING TO AROUND
40KT...CONDITIONS WILL BECOME BLUSTERY ACROSS THE AREA. ALONG THE
LAKE SUPERIOR SHORE AROUND THE TIP OF THE KEWEENAW AND FROM BIG BAY
EASTWARD...WINDS WILL PROBABLY GUST TO 35 TO 45 MPH IN THE AFTN.
DEPENDING ON HOW QUICKLY LES INCREASES IN THE AFTN...BLSN COULD
BECOME A SIGNIFICANT ISSUE NEAR THE LAKE.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 327 PM EST WED JAN 28 2015
A SHORTWAVE TROUGH WILL BE OVER THE CWA AT 00Z FRI...WITH MOST OF
THE ASSOCIATED FORCING E OF THE CWA BY THAT TIME. NW-NNW LOW LEVEL
WINDS AND 850MB TEMPS AS LOW AS -22C WILL KEEP SNOW GOING IN THE NW-
NNW WINDS SNOWBELTS THU NIGHT...BUT A SFC RIDGE PUSHING THROUGH ON
FRI WILL LEAD TO A DIMINISHING TREND IN THE LES AS WINDS BECOME ANTI-
CYCLONIC. WINDS TURN SWLY BY FRI NIGHT BEHIND THE TROUGH AND AHEAD
OF A CLIPPER SHORTWAVE/SFC TROUGH THAT WILL MOVE THROUGH LATE FRI
NIGHT/EARLY SAT. NW WIND LES WILL RAMP UP ALONG AND BEHIND THE
TROUGH AS 850MB WINDS AS LOW AS -30C SWEEP ACROSS THE AREA. TEMPS
LOOK TO MODERATE SOME MON INTO TUE AS A RIDGE MOVES THROUGH...WITH
ANOTHER COLD BLAST SHOWN BY MODELS TOWARD THE MIDDLE OF NEXT WEEK.
OVER THE NEXT WEEK THE NW WINDS SNOWBELTS MAINLY E OF MARQUETTE WILL
SEE THE MOST SNOWFALL...WITH PROLONGED LIGHT TO MODERATE SNOWFALL.
WITH THE VERY COLD AIRMASS... GROWTH WILL BE ADVERSELY
IMPACTED...WITH SMALL SNOW FLAKES EFFICIENT AT REDUCING VIS THE
PREDOMINANT CONDITION.
COLD TEMPS ARE A CERTAINTY...ESPECIALLY SUN AND MON WHEN HIGHS WILL
NOT MAKE IT OUT OF THE SINGLE DIGITS ABOVE ZERO IN MOST LOCATIONS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1154 PM EST WED JAN 28 2015
DISTURBANCE APPROACHING TONIGHT WILL BRING SOME -SN/DETERIORATING
CONDITIONS. ALL TERMINALS WILL LIKELY FALL TO IFR WITH A FEW HRS OF
LIFR POSSIBLE OVERNIGHT. THERE MAY BE A LITTLE
-FZDZ LATE TONIGHT AT KIWD. PASSAGE OF COLD FRONT
EARLY THU MORNING WILL BRING INCREASING...GUSTY NW
WINDS...ESPECIALLY AT THE MORE EXPOSED KCMX TERMINAL.
OTHERWISE...EXPECT IMPROVEMENT TO MVFR AT ALL TERMINALS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 444 PM EST WED JAN 28 2015
AHEAD OF AN APPROACHING LOW PRES TROF...S WINDS OF 20-30KT ARE
EXPECTED OVER ERN LAKE SUPERIOR TONIGHT. AS IS TYPICAL FOR SOUTHERLY
WINDS...WINDS WILL BE LIGHTER OVER THE W. THE TROF WILL PASS ACROSS
THE LAKE THU MORNING. BEHIND IT...N TO NW WINDS WILL INCREASE TO 20-
30KT OVER WRN LAKE SUPERIOR. OVER THE CNTRL AND ERN LAKE...WINDS
WILL INCREASE TO GALE FORCE (GUSTS TO AROUND 40KT) FOR THU AFTN AND
NIGHT. COMBINATION OF MUCH COLDER AIR/STRONG WINDS AND BUILDING
WAVES WILL LEAD TO HVY FREEZING SPRAY THU AFTN UNTIL EARLY FRI
MORNING WHEN WINDS/WAVES DIMINISH WITH THE CLOSER APPROACH OF
CANADIAN HIGH PRES. AFTER A PERIOD OF LIGHTER WINDS MOSTLY UNDER
20KT FRI AFTN/NIGHT...WINDS WILL INCREASE AGAIN TO 20-30KT
SAT...ESPECIALLY SAT AFTN/NIGHT...IN THE WAKE OF A LOW PRES TROUGH.
GALES MAY OCCUR OVER PORTIONS OF CNTRL LAKE SUPERIOR. WINDS SHOULD
DIMINISH FOR A TIME SUN BEFORE INCREASING AGAIN MON.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING FROM 1 PM THURSDAY TO 7 AM EST
FRIDAY FOR LSZ264-266-267.
GALE WARNING FROM 1 PM THURSDAY TO 4 AM EST FRIDAY FOR LSZ267.
GALE WARNING FROM 10 AM THURSDAY TO 4 AM EST FRIDAY FOR LSZ265-
266.
GALE WARNING FROM 7 AM THURSDAY TO 1 AM EST FRIDAY FOR LSZ263-
264.
HEAVY FREEZING SPRAY WARNING FROM 1 PM THURSDAY TO 1 AM EST
FRIDAY FOR LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...07
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1216 PM CST THU JAN 29 2015
.UPDATED FOR 18Z AVIATION DISCUSSION...
ISSUED AT 1201 PM CST THU JAN 29 2015
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 349 AM CST THU JAN 29 2015
SHORT TERM CONCERNS ARE HEADLINES EARLY THIS MORNING. THEN OVERALL
IMPROVING TREND AND TURNING COLDER.
RADAR CONTINUES TO SHOW SOME LIGHT INTENSITY ECHOES MOVING ACROSS
EAST CENTRAL MN. WATER VAPOR IMAGERY SHOWING SECONDARY TROUGH
MOVING INTO WESTERN MN NOW. THE TREND ON THE RAP HAS BEEN
GENERATING SOME LIGHT QPF INTO SOUTH CENTRAL MN THROUGH ABOUT 14Z.
NOTHING TOO DRAMATIC ON RADAR...ALTHOUGH SURFACE OBS CONTINUE TO
SHOW SOME VISIBILITY REDUCTION IN BR AND OCCASIONALLY SOME -SN OR UP.
WILL CONTINUE THE FREEZING RAIN ADVISORY THROUGH 12Z. WILL WORD
THAT PRECIPITATION SHOULD BE ENDING THIS MORNING.
THE OTHER CONCERN IS THE WIND ADV TO THE SOUTHWEST. WINDS HAVE BEEN
INCREASING TO THE WEST OVERNIGHT AS THE PRESSURE GRADIENT INCREASES
WITH THE COLD FRONT MOVING THROUGH. THIS SHOULD CONTINUE THROUGH AT
LEAST MID MORNING AS THE GREATEST PRESSURE RISE MOVES THROUGH THE
AREA. HAVE INCLUDED A COUPLE MORE COUNTIES IN WEST CENTRAL MN AS
WELL.
WINDS ARE EXPECTED TO DIMINISH OVERALL AFTER 18Z AND BECOME LIGHT
INTO TONIGHT. CLOUDS WILL THIS AS WELL WITH TEMPERATURES DROPPING
THROUGH THE SINGLE DIGITS AND TEENS FOR LOWS TONIGHT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 349 AM CST THU JAN 29 2015
WEST/NORTHWEST FLOW WILL PREVAIL THROUGH THE MAJORITY OF THE LONG
TERM FORECAST PERIOD...WITH ONLY MINOR/FLEETING CHANCES FOR
PRECIPITATION FORESEEN INTO EARLY NEXT WEEK.
FRIDAY WILL BE A TALE OF TWO STORIES WITHIN THE FORECAST AREA...AS
THE DEPARTING SURFACE HIGH YIELDS TEMPS AROUND 5 TO 10 DEGREES
BELOW NORMAL IN THE EAST OVER WISCONSIN...AND LOW LEVEL WARM AIR
ADVECTION OVER THE WEST BRINGS HIGHS FROM 5 TO 10 DEGREES ABOVE
NORMAL TO WEST CENTRAL AND SOUTHWESTERN MINNESOTA. EXPECT HIGH
TEMPS TO RANGE FROM 15 TO 20 DEGREES OVER WEST CENTRAL WI...TO THE
LOWER 30S ALONG THE MN RIVER VALLEY.
ON SATURDAY...THE GFS AND ECMWF MODELS ARE STICKING TO THEIR GUNS
IN PROGGING THE BULK OF THE PRECIPITATION TO PASS SOUTH OF THE
FORECAST AREA...AS AN INCOMING ARCTIC HIGH SUPPRESSES THE SYSTEM
LIFTING OUT OF THE SOUTHWESTERN CONUS. COULD SEE A LIGHT ROUND OF
SNOWFALL WITH INCH OR SO ACCUMULATIONS ON SATURDAY NIGHT AHEAD OF
THE APPROACHING HIGH...BUT THE MAIN /SOUTHERN STREAM/ SYSTEM
SHOULD STAY WELL SOUTH OF THE AREA.
THE ARCTIC HIGH WILL INEVITABLY BE ACCOMPANIED BY A NOTABLE
REDUCTION IN TEMPERATURES...WITH HIGHS FROM 5 TO 15 DEGREES ON
SUNDAY...AND SUB-ZERO LOWS OCCURRING NEARLY AREA-WIDE ON SUNDAY
NIGHT. ASSOCIATED WINDS WILL BE RATHER LIGHT...SO DO NOT CURRENTLY
EXPECT WIND CHILLS TO DIP LOWER THAN -15 TO -20 ON SUNDAY NIGHT
AND MONDAY MORNING.
AS THE HIGH SLIPS OFF TO THE SOUTHEAST...TEMPERATURES WILL
GRADUALLY MODERATE BACK TO NORMAL AS A SURFACE TROUGH APPROACHES
FROM THE NORTHERN ROCKIES. THIS FEATURE MAY BRING A LIGHT ROUND OF
SNOW ON MONDAY NIGHT INTO TUESDAY MORNING...DURING WHICH 20-30
POPS HAVE BEEN INCLUDED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1201 PM CST THU JAN 29 2015
MVFR CIGS WILL GRADUALLY THIN OUT LATER THIS AFTERNOON...WITH
CLEARING SKIES EXPECTED OVERNIGHT. NORTHWESTERLY WINDS WILL
DIMINISH TODAY AS WELL...BECOME LIGHT AND VARIABLE OVERNIGHT...AND
TAKE ON A SOUTHEASTERLY DIRECTION BY FRIDAY MORNING.
KMSP...
EXPECT A MIX OF VFR AND MVFR CONDITIONS BETWEEN 18-21Z TIMEFRAME.
BY EVEN CONDITIONS SHOULD BE VFR...WITH LIGHTER WINDS.
/OUTLOOK FOR KMSP/
SAT...VFR WITH MVFR CIGS/-SN POSSIBLE SAT NIGHT. WIND N AT 5-10KT.
SUN...VFR WITH MVFR CIGS POSSIBLE EARLY. WIND N AT 10 KT.
MON...VFR WITH MVFR/SN POSSIBLE LATE. WINDS S AT 10G15KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...DWE
LONG TERM...LS
AVIATION...JRB
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
546 AM CST THU JAN 29 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 349 AM CST THU JAN 29 2015
SHORT TERM CONCERNS ARE HEADLINES EARLY THIS MORNING. THEN OVERALL
IMPROVING TREND AND TURNING COLDER.
RADAR CONTINUES TO SHOW SOME LIGHT INTENSITY ECHOES MOVING ACROSS
EAST CENTRAL MN. WATER VAPOR IMAGERY SHOWING SECONDARY TROUGH
MOVING INTO WESTERN MN NOW. THE TREND ON THE RAP HAS BEEN
GENERATING SOME LIGHT QPF INTO SOUTH CENTRAL MN THROUGH ABOUT 14Z.
NOTHING TOO DRAMATIC ON RADAR...ALTHOUGH SURFACE OBS CONTINUE TO
SHOW SOME VISIBILITY REDUCTION IN BR AND OCCASIONALLY SOME -SN OR UP.
WILL CONTINUE THE FREEZING RAIN ADVISORY THROUGH 12Z. WILL WORD
THAT PRECIPITATION SHOULD BE ENDING THIS MORNING.
THE OTHER CONCERN IS THE WIND ADV TO THE SOUTHWEST. WINDS HAVE BEEN
INCREASING TO THE WEST OVERNIGHT AS THE PRESSURE GRADIENT INCREASES
WITH THE COLD FRONT MOVING THROUGH. THIS SHOULD CONTINUE THROUGH AT
LEAST MID MORNING AS THE GREATEST PRESSURE RISE MOVES THROUGH THE
AREA. HAVE INCLUDED A COUPLE MORE COUNTIES IN WEST CENTRAL MN AS
WELL.
WINDS ARE EXPECTED TO DIMINISH OVERALL AFTER 18Z AND BECOME LIGHT
INTO TONIGHT. CLOUDS WILL THIS AS WELL WITH TEMPERATURES DROPPING
THROUGH THE SINGLE DIGITS AND TEENS FOR LOWS TONIGHT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 349 AM CST THU JAN 29 2015
WEST/NORTHWEST FLOW WILL PREVAIL THROUGH THE MAJORITY OF THE LONG
TERM FORECAST PERIOD...WITH ONLY MINOR/FLEETING CHANCES FOR
PRECIPITATION FORESEEN INTO EARLY NEXT WEEK.
FRIDAY WILL BE A TALE OF TWO STORIES WITHIN THE FORECAST AREA...AS
THE DEPARTING SURFACE HIGH YIELDS TEMPS AROUND 5 TO 10 DEGREES
BELOW NORMAL IN THE EAST OVER WISCONSIN...AND LOW LEVEL WARM AIR
ADVECTION OVER THE WEST BRINGS HIGHS FROM 5 TO 10 DEGREES ABOVE
NORMAL TO WEST CENTRAL AND SOUTHWESTERN MINNESOTA. EXPECT HIGH
TEMPS TO RANGE FROM 15 TO 20 DEGREES OVER WEST CENTRAL WI...TO THE
LOWER 30S ALONG THE MN RIVER VALLEY.
ON SATURDAY...THE GFS AND ECMWF MODELS ARE STICKING TO THEIR GUNS
IN PROGGING THE BULK OF THE PRECIPITATION TO PASS SOUTH OF THE
FORECAST AREA...AS AN INCOMING ARCTIC HIGH SUPPRESSES THE SYSTEM
LIFTING OUT OF THE SOUTHWESTERN CONUS. COULD SEE A LIGHT ROUND OF
SNOWFALL WITH INCH OR SO ACCUMULATIONS ON SATURDAY NIGHT AHEAD OF
THE APPROACHING HIGH...BUT THE MAIN /SOUTHERN STREAM/ SYSTEM
SHOULD STAY WELL SOUTH OF THE AREA.
THE ARCTIC HIGH WILL INEVITABLY BE ACCOMPANIED BY A NOTABLE
REDUCTION IN TEMPERATURES...WITH HIGHS FROM 5 TO 15 DEGREES ON
SUNDAY...AND SUB-ZERO LOWS OCCURRING NEARLY AREA-WIDE ON SUNDAY
NIGHT. ASSOCIATED WINDS WILL BE RATHER LIGHT...SO DO NOT CURRENTLY
EXPECT WIND CHILLS TO DIP LOWER THAN -15 TO -20 ON SUNDAY NIGHT
AND MONDAY MORNING.
AS THE HIGH SLIPS OFF TO THE SOUTHEAST...TEMPERATURES WILL
GRADUALLY MODERATE BACK TO NORMAL AS A SURFACE TROUGH APPROACHES
FROM THE NORTHERN ROCKIES. THIS FEATURE MAY BRING A LIGHT ROUND OF
SNOW ON MONDAY NIGHT INTO TUESDAY MORNING...DURING WHICH 20-30
POPS HAVE BEEN INCLUDED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 540 AM CST THU JAN 29 2015
FREEZING DRIZZLE THREAT ENDING TO THE SOUTHEAST. TRANSITIONED TO
SNOW SHOWERS/FLURRIES UPSTREAM. THIS SHOULD COME TO AN END IN AN
THROUGH MID MORNING. THEN MVFR CIGS SHOULD GRADUALLY BREAK FROM
WEST TO EAST THROUGH THE LATE AFTERNOON/EVENING. EXPECT VFR
CONDITIONS THEN INTO THE LATE EVENING WITH SOME MID/HIGH LEVEL
CLOUDS RETURNING LATE. STRONG NW WINDS GUSTING 35-40KTS OUT IN
WESTERN AREAS THIS MORNING...DIMINISHING FROM WEST TO EAST INTO
EARLY EVENING.
KMSP...FREEZING DRIZZLE THREAT HAS ENDED. SOME FLURRIES POSSIBLE
FOR AN HOUR OR TWO. MVFR CONDITIONS EXPECTED THROUGH ABOUT 22Z.
THEN BECOMING VFR THROUGH THE REST OF THE PERIOD. SOME MID HIGH
LEVEL CLOUDS MOVE IN LATE TONIGHT BUT WILL REMAIN VFR. STRONG NW
WINDS GUSTING AROUND 25KTS THROUGH THE DAY...DIMINISHING THIS
EVENING AND BECOMING LIGHT SOUTHEAST FRIDAY MORNING.
/OUTLOOK FOR KMSP/
FRI AFTERNOON...VFR. WIND S 5 KT.
SAT...MAINLY VFR...CHC MVFR CIGS/-SN SAT NIGHT. WIND N 5-10 KT.
SUN...MAINLY VFR...CHC MVFR CIGS EARLY. WIND N 10 KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...FREEZING RAIN ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR
MNZ051>053-059>063-066>070-075>078-083>085.
WIND ADVISORY UNTIL 9 AM CST THIS MORNING FOR MNZ047-048-054>057-
064-065-073>075-082>084-091>093.
WI...FREEZING RAIN ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR
WIZ014>016-023>028.
&&
$$
SHORT TERM...DWE
LONG TERM...LS
AVIATION...DWE
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
349 AM CST THU JAN 29 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 349 AM CST THU JAN 29 2015
SHORT TERM CONCERNS ARE HEADLINES EARLY THIS MORNING. THEN OVERALL
IMPROVING TREND AND TURNING COLDER.
RADAR CONTINUES TO SHOW SOME LIGHT INTENSITY ECHOES MOVING ACROSS
EAST CENTRAL MN. WATER VAPOR IMAGERY SHOWING SECONDARY TROUGH
MOVING INTO WESTERN MN NOW. THE TREND ON THE RAP HAS BEEN
GENERATING SOME LIGHT QPF INTO SOUTH CENTRAL MN THROUGH ABOUT 14Z.
NOTHING TOO DRAMATIC ON RADAR...ALTHOUGH SURFACE OBS CONTINUE TO
SHOW SOME VISIBILITY REDUCTION IN BR AND OCCASIONALLY SOME -SN OR UP.
WILL CONTINUE THE FREEZING RAIN ADVISORY THROUGH 12Z. WILL WORD
THAT PRECIPITATION SHOULD BE ENDING THIS MORNING.
THE OTHER CONCERN IS THE WIND ADV TO THE SOUTHWEST. WINDS HAVE BEEN
INCREASING TO THE WEST OVERNIGHT AS THE PRESSURE GRADIENT INCREASES
WITH THE COLD FRONT MOVING THROUGH. THIS SHOULD CONTINUE THROUGH AT
LEAST MID MORNING AS THE GREATEST PRESSURE RISE MOVES THROUGH THE
AREA. HAVE INCLUDED A COUPLE MORE COUNTIES IN WEST CENTRAL MN AS
WELL.
WINDS ARE EXPECTED TO DIMINISH OVERALL AFTER 18Z AND BECOME LIGHT
INTO TONIGHT. CLOUDS WILL THIS AS WELL WITH TEMPERATURES DROPPING
THROUGH THE SINGLE DIGITS AND TEENS FOR LOWS TONIGHT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 349 AM CST THU JAN 29 2015
WEST/NORTHWEST FLOW WILL PREVAIL THROUGH THE MAJORITY OF THE LONG
TERM FORECAST PERIOD...WITH ONLY MINOR/FLEETING CHANCES FOR
PRECIPITATION FORESEEN INTO EARLY NEXT WEEK.
FRIDAY WILL BE A TALE OF TWO STORIES WITHIN THE FORECAST AREA...AS
THE DEPARTING SURFACE HIGH YIELDS TEMPS AROUND 5 TO 10 DEGREES
BELOW NORMAL IN THE EAST OVER WISCONSIN...AND LOW LEVEL WARM AIR
ADVECTION OVER THE WEST BRINGS HIGHS FROM 5 TO 10 DEGREES ABOVE
NORMAL TO WEST CENTRAL AND SOUTHWESTERN MINNESOTA. EXPECT HIGH
TEMPS TO RANGE FROM 15 TO 20 DEGREES OVER WEST CENTRAL WI...TO THE
LOWER 30S ALONG THE MN RIVER VALLEY.
ON SATURDAY...THE GFS AND ECMWF MODELS ARE STICKING TO THEIR GUNS
IN PROGGING THE BULK OF THE PRECIPITATION TO PASS SOUTH OF THE
FORECAST AREA...AS AN INCOMING ARCTIC HIGH SUPPRESSES THE SYSTEM
LIFTING OUT OF THE SOUTHWESTERN CONUS. COULD SEE A LIGHT ROUND OF
SNOWFALL WITH INCH OR SO ACCUMULATIONS ON SATURDAY NIGHT AHEAD OF
THE APPROACHING HIGH...BUT THE MAIN /SOUTHERN STREAM/ SYSTEM
SHOULD STAY WELL SOUTH OF THE AREA.
THE ARCTIC HIGH WILL INEVITABLY BE ACCOMPANIED BY A NOTABLE
REDUCTION IN TEMPERATURES...WITH HIGHS FROM 5 TO 15 DEGREES ON
SUNDAY...AND SUB-ZERO LOWS OCCURRING NEARLY AREA-WIDE ON SUNDAY
NIGHT. ASSOCIATED WINDS WILL BE RATHER LIGHT...SO DO NOT CURRENTLY
EXPECT WIND CHILLS TO DIP LOWER THAN -15 TO -20 ON SUNDAY NIGHT
AND MONDAY MORNING.
AS THE HIGH SLIPS OFF TO THE SOUTHEAST...TEMPERATURES WILL
GRADUALLY MODERATE BACK TO NORMAL AS A SURFACE TROUGH APPROACHES
FROM THE NORTHERN ROCKIES. THIS FEATURE MAY BRING A LIGHT ROUND OF
SNOW ON MONDAY NIGHT INTO TUESDAY MORNING...DURING WHICH 20-30
POPS HAVE BEEN INCLUDED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1127 PM CST WED JAN 28 2015
LARGE AREA OF -FZDZ SLOWLY ERODING AWAY TO THE E AS CDFNT MAKES
PROGRESS THRU THE CWFA. THIS IS ALLOWING WRN MN TO HAVE CEILINGS
RISE FROM IFR RANGE TO MVFR RANGE WHILE VSBY INCRS TO VFR. THIS
TREND WILL CONTINUE EWD SLOWLY THRU THE EARLY MRNG HRS. IN
CONJUNCTION WITH THE CLEARING WILL BE A STRONG SURGE IN WIND
SPEEDS IN THE WAKE OF THE CDFNT. NW WINDS WILL INCREASE TO 15-25
KT WITH HIGHER GUSTS DURG THE EARLY MRNG HRS...LASTING THRU THU
AFTN BEFORE SPEEDS DISSIPATE THU EVE. THE INCRS IN WIND SPEEDS
WILL HELP SCOUR OUT NEAR-SFC MOISTURE...ALLOWING VSBYS TO QUICKLY
INCRS BUT THE LOW STRATUS WILL LINGER FOR MUCH OF THE DAY. BY LATE
AFTN...ANY LINGERING LOW STRATUS WILL SCATTER OUT...RESULTING IN
VFR CONDS BY LATE THU AFTN INTO THU EVE.
KMSP...HAVE INITIALIZED WITH IFR CONDS BUT AS THE CDFNT CONTINUES
TO SHIFT E ACRS THE AREA...VSBY WILL QUICKLY IMPROVE BETWEEN 06Z-
08Z TO VFR CONDS. CIGS WILL BE SLOW TO FOLLOW BY AM EXPECTING CIGS
TO RISE INTO MVFR RANGE BY 08Z. STILL SOME QUESTION AS TO HOW
QUICKLY CIGS RISE ABOUT THE 1700 FT THRESHOLD...AND IF ANYTHING...
THE TIMING MAY BE LATER THAN THE 14Z TIMEFRAME CURRENTLY
ADVERTISED. OTHERWISE...CONDS ARE ON TRACK TO REACH VFR LEVELS BY
LATE THU AFTN WITH CONTINUED IMPROVEMENT THRU THU NIGHT.
/OUTLOOK FOR KMSP/
FRI...VFR. WIND S 5 KT.
SAT...MAINLY VFR...CHC MVFR CIGS/-SN. WIND N 5-10 KT.
SUN...MAINLY VFR...CHC MVFR CIGS. WIND N 10 KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...FREEZING RAIN ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR
MNZ051>053-059>063-066>070-075>078-083>085.
WIND ADVISORY UNTIL 9 AM CST THIS MORNING FOR MNZ047-048-054>057-
064-065-073>075-082>084-091>093.
WI...FREEZING RAIN ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR
WIZ014>016-023>028.
&&
$$
SHORT TERM...DWE
LONG TERM...LS
AVIATION...JPC
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1134 PM CST WED JAN 28 2015
.UPDATE...
ISSUED AT 1127 PM CST WED JAN 28 2015
UPDATED TO INCLUDE 06Z AVIATION DISCUSSION BELOW.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 342 PM CST WED JAN 28 2015
AN ACTIVE SHORT TERM AHEAD AS A LOW PRESSURE SYSTEM OVER THE
EASTERN DAKOTAS SLIDES SOUTHEAST INTO NORTHERN IL BY THURSDAY
MORNING. LITTLE ICE IS INDICATED ALOFT OVER NORTHERN AND EASTERN
AREAS OF THE FA TONIGHT WITH DEEPENING LOW LEVEL SATURATION. IN
ADDITION...SOUTHERLY LOW LEVEL WINDS INCREASE RATHER DRAMATICALLY
EARLY TONIGHT ACROSS EASTERN IA ON NORTHWARD INTO WEST CENTRAL
WI...WITH A VEERING PROFILE THROUGH 800MB. THIS SHOULD ADD THE
TURBULENCE FACTOR TO ALLOW FREEZING DRIZZLE TO BECOME WIDESPREAD
ACROSS MUCH OF WEST CENTRAL WI FROM AROUND MID EVENING INTO EARLY
THURSDAY MORNING. THIS IS COLLABORATED BY RUNS TODAY OF THE
HOPWRF...HRRR AND RAP SHOWING SOME A FEW HUNDREDTHS OF QPF IN THE
AFOREMENTIONED AREAS. THEREFORE...ISSUED A FREEZING RAIN ADVISORY
FROM 9 PM THROUGH 3 AM FROM RICE LAKE AND LADYSMITH ON SOUTH
THROUGH MENOMONIE AND AUGUSTA. THE EVENING SHIFT WILL NEED TO KEEP
A CLOSE EYE FROM THE TWIN CITIES ON NORTHWARD WHERE CONFIDENCE ON
THE FREEZING DRIZZLE IS LOWER.
IN THE WAKE OF THE LOW PRESSURE SYSTEM...THE SURFACE PRESSURE
GRADIENT INCREASES SIGNIFICANTLY ACROSS EASTERN SD AND SW MN
AFTER MIDNIGHT (12 MILLIBARS). IN FACT...6 HOUR PRESSURE CHANGES
ARE NEAR 14 MILLIBARS TO OUR WEST. BUFKIT PROFILE DATA SHOWED TWO
THINGS. FIRST...THE NAM PROFILE HAD THE STRONGEST TOP OF THE
CHANNEL WINDS NEARING 50 KNOTS ACROSS THE MN RIVER VALLEY AROUND
09Z WHILE THE GFS PROFILE HAD 32 KNOT WINDS AT 200 FEET AT KFRM.
THE COMBINATION OF CAA AND A UNIDIRECTIONAL FLOW TO THE TOP OF THE
CHANNEL RESULTED IN A WIND ADVISORY BEING ISSUED ALONG AND SOUTH
OF A LINE FROM APPLETON TO ALBERT LEA FROM MIDNIGHT THROUGH 9 AM.
TEMPERATURES TONIGHT AND THURSDAY ARE INTERESTING. BECAUSE OF THE
LOW PRESSURE SYSTEM COMING INTO THE AREA TONIGHT...TEMPERATURES
WILL WARM A LITTLE THIS EVENING AND THEN DROP BACK TO A LITTLE
BELOW WHERE WE ARE NOW. THURSDAY`S HIGHS WILL BE EARLY IN THE
MORNING WITH READINGS FALLING INTO THE TEENS AND LOWER 20S BY
THIS TIME THURSDAY AFTERNOON.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 342 PM CST WED JAN 28 2015
BY TOMORROW EVENING...THE PRESSURE GRADIENT WILL BE WEAKENING AND
THOSE STRONG NORTHWESTERLY WINDS WILL START TO SLOWLY DECREASE. A
SURFACE HIGH WILL DRIFT SOUTHEAST THROUGH OUR AREA OVERNIGHT
THROUGH FRIDAY MORNING...WHICH WILL BE ONE OF THE COOLER
MORNINGS WE`VE HAD IN TWO+ WEEKS WITH LOWS RANGING FROM NEAR ZERO
NEAR LADYSMITH...TO ABOUT 10-15 ABOVE TOWARD REDWOOD FALLS. THE
CORE OF THE COLD WILL ESSENTIALLY MISS US TO THE EAST AS IT IS
DRAGGED SOUTH BEHIND THE SYSTEM IMPACTING OUT REGION TONIGHT.
ON FRIDAY...MODEST WARM AIR ADVECTION WILL ENSUE AND ALLOW
TEMPERATURES TO WARM TO VERY NEAR SEASONAL NORMALS. WITH THE COLDER
AIR IN PLACE TO THE EAST OF THE AREA...HIGHS WILL STRUGGLE TO REACH
20 IN WEST CENTRAL WI...BUT WARMER AIR THE FURTHER WEST YOU GO WILL
YIELD HIGHS IN THE MID 20S FOR EASTERN MN AND LOW 30S ACROSS FAR
SOUTHWESTERN MN.
THE MAIN CHANGE FROM THE PREVIOUS FORECAST WAS TO THE SATURDAY
NIGHT SYSTEM. BOTH THE GFS AND EC RUNS CAME IN WITH A STRONG
SURFACE HIGH PUSHING SOUTH FROM SASKATCHEWAN INTO THE UPPER
MIDWEST AS THE NORTHERN STREAM JET BUCKLES SOUTHWARD ALLOWING DRY
ARCTIC AIR TO ADVANCE FURTHER SOUTH THAN PREVIOUS RUNS INDICATED.
THIS IS A GREAT HINDRANCE TO THE POTENTIAL FOR SNOW FROM A SYSTEM
DEVELOPING IN THE SOUTHWESTERN CONUS. BUT...THERE IS POTENTIAL FOR
LIGHT SNOW FROM A NORTHERN STREAM SHORTWAVE SATURDAY NIGHT. THIS
LINES UP WELL WITH AN ENHANCED AREA OF PV ADVECTING SOUTHEAST AND
IN CONJUNCTION WITH THE LEFT EXIT REGION OF A 120KT JET STREAK.
ANY SNOW THAT DOES FALL THROUGH WILL BE VERY LIGHT WITH THE PRE-
EXISTING LOW LEVEL DRY AIR.
IT LOOKS LIKE WE`LL BEGIN FEBRUARY WITH TEMPERATURES SLIGHTLY BELOW
NORMAL AFTER AN IMPRESSIVE WARM STRETCH FOR THE LAST 3 WEEKS OF
JANUARY. BOUTS OF ARCTIC AIR WILL DROP SOUTH THROUGH THE
NORTHERN/NORTHEASTERN GREAT LAKES...GIVING US MORE OF A GLANCING
BLOW. ANOTHER POSSIBLE CLIPPER SYSTEM COULD BRING ANOTHER SHOT OF
VERY LIGHT SNOW MONDAY NIGHT/TUESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1127 PM CST WED JAN 28 2015
LARGE AREA OF -FZDZ SLOWLY ERODING AWAY TO THE E AS CDFNT MAKES
PROGRESS THRU THE CWFA. THIS IS ALLOWING WRN MN TO HAVE CEILINGS
RISE FROM IFR RANGE TO MVFR RANGE WHILE VSBY INCRS TO VFR. THIS
TREND WILL CONTINUE EWD SLOWLY THRU THE EARLY MRNG HRS. IN
CONJUNCTION WITH THE CLEARING WILL BE A STRONG SURGE IN WIND
SPEEDS IN THE WAKE OF THE CDFNT. NW WINDS WILL INCREASE TO 15-25
KT WITH HIGHER GUSTS DURG THE EARLY MRNG HRS...LASTING THRU THU
AFTN BEFORE SPEEDS DISSIPATE THU EVE. THE INCRS IN WIND SPEEDS
WILL HELP SCOUR OUT NEAR-SFC MOISTURE...ALLOWING VSBYS TO QUICKLY
INCRS BUT THE LOW STRATUS WILL LINGER FOR MUCH OF THE DAY. BY LATE
AFTN...ANY LINGERING LOW STRATUS WILL SCATTER OUT...RESULTING IN
VFR CONDS BY LATE THU AFTN INTO THU EVE.
KMSP...HAVE INITIALIZED WITH IFR CONDS BUT AS THE CDFNT CONTINUES
TO SHIFT E ACRS THE AREA...VSBY WILL QUICKLY IMPROVE BETWEEN 06Z-
08Z TO VFR CONDS. CIGS WILL BE SLOW TO FOLLOW BY AM EXPECTING CIGS
TO RISE INTO MVFR RANGE BY 08Z. STILL SOME QUESTION AS TO HOW
QUICKLY CIGS RISE ABOUT THE 1700 FT THRESHOLD...AND IF ANYTHING...
THE TIMING MAY BE LATER THAN THE 14Z TIMEFRAME CURRENTLY
ADVERTISED. OTHERWISE...CONDS ARE ON TRACK TO REACH VFR LEVELS BY
LATE THU AFTN WITH CONTINUED IMPROVEMENT THRU THU NIGHT.
/OUTLOOK FOR KMSP/
FRI...VFR. WIND S 5 KT.
SAT...MAINLY VFR...CHC MVFR CIGS/-SN. WIND N 5-10 KT.
SUN...MAINLY VFR...CHC MVFR CIGS. WIND N 10 KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...FREEZING RAIN ADVISORY UNTIL 6 AM CST THURSDAY FOR MNZ041>045-
047>053-055>063-065>070-075>078-083>085.
WIND ADVISORY UNTIL 9 AM CST THURSDAY FOR MNZ054-056-064-065-
073>075-082>084-091>093.
WI...FREEZING RAIN ADVISORY UNTIL 6 AM CST THURSDAY FOR WIZ014>016-
023>028.
&&
$$
UPDATE...JPC
SHORT TERM...RAH
LONG TERM...SPD
AVIATION...JPC
AREA FORECAST DISCUSSION
NWS BILLINGS MT
929 PM MST WED JAN 28 2015
.UPDATE...
WEAK SHORTWAVE CONTINUES TO PRODUCE A FEW ECHOES IN OUR CENTRAL
PARTS...AND WILL SUSTAIN FLURRIES/SPRINKLES THROUGH MIDNIGHT...
WITH DESCENT SPREADING IN THEREAFTER ENDING ANY PCPN CHANCES.
THERE WAS A BRIEF PERIOD OF UPSLOPE ENHANCEMENT ALONG THE SE EDGE
OF THE BEARTOOTH FOOTHILLS EARLIER THIS EVENING...AND IN FACT WE
RECEIVED A SPOTTER REPORT OF ABOUT AN INCH OF SNOW IN RED LODGE.
PCPN IS MUCH LIGHTER NOW. AREA OF STRATUS CONTINUES TO CLIP OUR
FAR EAST NEAR BAKER AND EKALAKA. SOUNDINGS MAY BE A BIT OVERDONE
WITH THE LOW LEVEL MOISTURE BASED ON LOCAL METARS...BUT GIVEN THE
BOUNDARY LAYER MOISTURE AND INSTABILITY WITH TEMPS NO COLDER THAN
-8C...FEEL SOME LIGHT FREEZING DRIZZLE IS STILL A POSSIBILITY
MAINLY OVER THE HILLS OF FALLON AND NORTHERN CARTER COUNTIES WHERE
THE TERRAIN WILL BE CLOSER TO THE CLOUD BASES. ONLY OTHER ISSUE IS
FOG POTENTIAL. DEW PT DEPRESSIONS AT JDN AND MLS ALREADY DOWN TO
2-3F...WITH CLEAR SKIES AND DECREASING WINDS EXPECTED THRU THE
NIGHT. HRRR IS PINGING NORTHERN ROSEBUD WITH FOG TONIGHT...AND
THIS AREA JUST WEST OF THE CURRENTLY OBSERVED WNW WINDS MAKES
SENSE. COULD SEE SOME VALLEY FOG DEVELOP NEAR OR MAYBE JUST EAST
OF BILLINGS TOO... WITH STRONGER DRAINAGE EXPECTED TO HOLD OFF TIL
AROUND 15Z TOMORROW. HAVE EXPANDED COVERAGE OF PATCHY FOG WESTWARD
TO INCLUDE THESE AREAS. JKL
&&
.SHORT TERM...VALID FOR THU AND FRI...
SHORT WAVE THAT BROUGHT SOME SNOW TO THE HIGH COUNTRY LAST NIGHT
HAS EXCITED THE REGION...BUT COLD AIR IS BEING PULLED DOWN FROM
THE NORTH BEHIND IT. ASSOCIATED STRATUS ON VISIBLE SATELLITE
IMAGERY WAS MOVING INTO OUR NORTHERN ZONES AT MIDDAY AND IS
EXPECTED TO SPREAD ACROSS MUCH OF OUR CENTRAL/EASTERN ZONES BY
EVENING. CROSS SECTIONS INDICATE THE STRATUS WILL LINGER THROUGH
THE NIGHT BEFORE GRADUALLY DISSIPATING EARLY THURSDAY FROM WEST TO
EAST. THERE WILL BE A TYPICAL TRADE-OFF BETWEEN CAA AND LINGERING
STRATUS TONIGHT TO MAKE OVERNIGHT LOWS TRICKY IN OUR EAST...BUT
FEEL CAA WILL GENERALLY WIN OUT AND HAVE STUCK CLOSE TO INHERITED
FORECASTS/GUIDANCE. THERE WILL CERTAINLY BE A COOLER AIR MASS IN
PLACE OVER US TOMORROW...BUT NOTHING DRASTIC AND WE SHOULD BRIEFLY
SEE SOME SUNSHINE AROUND MIDDAY KEEPING US ON THE MILD SIDE
COMPARED TO SEASONAL AVERAGES.
THE OVERALL FLOW PATTERN IS STILL ANTICYCLONIC THURSDAY WITH SOME
WEAK QUASI LOW PRESSURE LINGERING OVER THE GREAT BASIN.
HOWEVER...WE BEGIN TO TRANSITION TO A BRISK NW FLOW ALOFT WITH
SHORT WAVE ENERGY OUT OF CANADA TRACKING THROUGH NE MONTANA BY
LATE FRIDAY NIGHT. THIS MAY OPEN THE DOOR TO UNSETTLED AND MUCH
COOLER WEATHER FOR THE WEEKEND. PLEASE SEE THE LONG TERM
DISCUSSION BELOW FOR MORE DETAILS. BT
.LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED...
A CHANGE IN THE PATTERN TO COLDER WEATHER WITH PERIODS OF SNOW
APPEARS LIKELY FOR THE EXTENDED PERIOD BEGINNING ON SAT. WHILE
MODELS AGREED WITH THIS OVERALL SCENARIO...THE PATTERN DETAILS
DIFFERED BETWEEN THEM.
JET ENERGY WILL DIVE SE INTO THE AREA ON SAT ACCOMPANIED BY A
SHORTWAVE AND BACKDOOR COLD FRONT. GFS WAS THE MOST AGGRESSIVE
MODEL IN BRINGING QPF SW INTO THE AREA COMPARED TO THE OTHER
MODELS. THE CANADIAN AND ECMWF BRING THE QPF IN ON SAT NIGHT.
BASED ON THE TIMING UNCERTAINTY...SLOWED DOWN ARRIVAL OF HIGHER
POPS IN THE SW PART OF THE AREA ON SAT...AND WENT WITH MAINLY
CHANCE POPS SAT NIGHT.
FLOW THEN TRANSITIONS INTO A FLAT NW FLOW ON THE MODELS FOR SUN
INTO TUE. MODELS HAD PACIFIC MOISTURE OVERRUNNING THE SURFACE
BOUNDARY ON SUN BUT DIFFERED IN THEIR QPF DEPICTIONS. WEAK
SHORTWAVE ENERGY REINFORCES THE COLD AIR OVER THE REGION ON MON
AND TUE WHILE PACIFIC MOISTURE CONTINUES TO OVERRUN THE BOUNDARY.
BLENDED POPS FOR THIS TIME FRAME WITH THE SUPERBLEND GUIDANCE AS
THE MODELS DIFFERED IN PRECIPITATION DETAILS. INHERITED TUE POPS
LOOKED REASONABLE.
ENERGY THEN WRAPS AROUND THE HUDSON BAY LOW FOR THE END
OF THE PERIOD. THIS ENERGY WILL REINFORCE THE COLD AIRMASS OVER
THE AREA. WILL CONTINUE TO USE A MODEL BLEND FOR POPS.
TEMPERATURE PROFILES ALSO DIFFERED BETWEEN THE MODELS FOR MUCH OF
THE PERIOD SO WENT WITH SUPERBLEND. RESULT WAS PERIODS OF
SEASONAL AND BELOW NORMAL TEMPERATURES. ARTHUR
&&
.AVIATION...
LOW CLOUDS AND PATCHY FOG WILL RESULT IN MVFR/IFR CONDITIONS EAST
OF KBIL THROUGH EARLY THURSDAY MORNING. SOME FREEZING DRIZZLE IS
ALSO POSSIBLE AROUND KBHK. AREA MOUNTAINS WILL BE OBSCURED AT
TIMES. ELSEWHERE...VFR CONDITIONS WILL PREVAIL UNDER PARTLY CLOUDY
SKIES. HOOLEY
&&
.PRELIMINARY POINT TEMP/POPS...
THU FRI SAT SUN MON TUE WED
-----------------------------------------------------------
BIL 028/048 030/050 028/038 019/030 022/041 027/039 019/032
10/U 00/U 03/W 33/J 33/W 32/W 23/J
LVM 028/048 027/048 024/040 020/036 025/045 029/043 024/038
00/U 00/U 03/W 23/J 43/W 32/W 23/W
HDN 022/046 025/048 023/035 015/029 017/038 021/035 015/030
10/U 00/U 03/W 32/J 33/J 33/J 23/J
MLS 025/044 027/044 024/032 011/023 014/032 017/028 011/025
10/U 00/U 04/J 22/J 22/J 23/J 22/J
4BQ 025/048 027/049 025/037 015/029 018/039 021/035 016/030
00/U 00/U 03/W 32/J 22/W 23/J 22/J
BHK 025/040 024/043 021/028 007/020 009/029 015/027 009/023
10/B 00/U 04/J 32/J 22/J 23/J 22/J
SHR 022/044 020/045 020/037 015/029 016/040 020/038 017/032
10/U 00/U 03/W 32/J 22/W 32/J 23/J
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
926 PM CST FRI JAN 30 2015
.UPDATE...
ISSUED AT 907 PM CST FRI JAN 30 2015
THE OVERALL TREND OF THE FORECAST REMAINS ON TRACK WITH
PRECIPITATION SPREADING NORTHEAST OUT OF CENTRAL KANSAS...THEN
DEVELOPING NORTH TOWARD THE NE/SD BORDER REGION. BELIEVE PRECIP
TYPE WILL BE THE ISSUE AND POSSIBLE CHANGEOVER TIME WHICH
COMPLICATES THE FORECAST.
00Z NAM REMAINS VERY AGGRESSIVE WITH PRECIP DEVELOPMENT WITH 0.88
INCHES OF QPF AT KOMA THROUGH 48 HOURS. BUFKIT SOUNDINGS SUGGEST
A FAIRLY RAPID CHANGEOVER TO SNOW WITH STRONG DYNAMICAL COOLING
TAKING PLACE ACROSS THE REGION...WITH ABOUT 4 G/KG OF SPECIFIC
HUMIDITY NOTED ON THE 290K ISENTROPIC SURFACE SO THERE IS PLENTY
OF MOISTURE TO WORK WITH. INDEED...00Z SUBJECTIVE UPPER AIR
ANALYSIS INDICATES FAIRLY DEEP AND SATURATED MOISTURE STREAMING
NORTHWARD WITH ABOUT 0.6 TO 0.8 INCHES OF PW...WHICH IS IN THE
97.5-99 NAEFS PW CLIMATOLOGICAL PERCENTILE ALONG AND SOUTH OF I80.
AN INITIAL CONCERN IS THAT PRECIP COULD POTENTIALLY CHANGE OVER
TO ALL SNOW EARLIER THAN FORECAST RESULTING IN HIGHER SNOWFALL
TOTALS. THE SECOND CONCERN IS THE RATHER DEEP SATURATION THAT IS
PROGGED TO OVERSPREAD THE REGION RESULTING IN HIGHER QPF THAN
FORECAST. MODEL SUITES ARE ALL GENERATING 0.7 TO 0.9 INCHES OF
QPF AND OUR FORECAST REMAINS BELOW THAT BY ABOUT ONE QUARTER
INCH. ONE MITIGATING FACTOR IS THE SREF PROBABILITY OF
ACCUMULATION ON ROADS PRODUCT REMAINS LOW MUCH OF THE DAY
SATURDAY...HOLDING OFF UNTIL WELL AFTER DARK BEFORE ROADWAYS
BECOME SIGNIFICANTLY IMPACTED. THAT DOESN`T MEAN WOULD WOULDN`T
STILL BE ABLE TO ACCUMULATE SNOWFALL ON GRASSY SURFACES THOUGH.
WILL WAIT FOR GFS...SREF...HIRES AND ECMWF MODELS BEFORE MAKING
MAJOR CHANGES...BUT INITIAL THOUGHTS ARE THAT QPF/SNOW AMOUNTS
MAY NEED TO BE RAISED. EARLY IN THE EVENT...WINDS WILL ALSO REMAIN
GENERALLY LIGHT LESS THAN 10 MPH WHICH WILL HELP QUITE A BIT.
CURRENT STORM TOTAL SNOWFALL FORECAST RANGES FROM 1 TO 4 INCHES
ACROSS THE REGION...BUT AGAIN...WILL WAIT FOR COMPLETE MODEL
SUITES TO MAKE ANY UPWARD ADJUSTMENTS.
&&
.SHORT TERM...(TONIGHT THROUGH MONDAY)
ISSUED AT 310 PM CST FRI JAN 30 2015
PCPN TYPE AND PCPN AMOUNTS WILL BE THE MAIN CONCERN IN THIS PERIOD...
ESPECIALLY FROM LATE TONIGHT INTO SATURDAY EVENING. PCPN SHOULD TURN
TO MOSTLY SNOW BY LATE SATURDAY NIGHT ALL AREAS.
WATER VAPOR LOOP AND LATEST RAP MODEL INITIALIZATIONS SHOWED A
CLOSED LOW OVER THE CALIFORNIA/ARIZONA BORDER REGION EARLY THIS
AFTN. THIS WILL DROP SOUTHWARD INTO MEXICO THROUGH SUNDAY. SOME
SHORTWAVE ENERGY WILL MOVE NORTHEAST OUT OF THIS TROUGH THOUGH AND
MOVE UP INTO THE CENTRAL PLAINS LATER TONIGHT AND SATURDAY. SURFACE
ANALYSIS EARLY THIS AFTERNOON SHOWED MODEST SOUTH/SOUTHWEST WINDS
SPREADING ACROSS OUR AREA. CLOUDS WILL THICKEN AND LOWER...WITH
LIGHT PCPN PROBABLY MOVING INTO OUR SOUTHERN COUNTIES BEFORE 12Z.
HAVE LOWS FORECAST IN THE UPPER 20S NORTH AND LOWER 30S SOUTH. THE
PCPN TYPE MAY BE A MIX LATER TONIGHT INTO SATURDAY.
DID MAKE SOME MODIFICATIONS TO SNOW AMOUNTS...MAINLY FOR SATURDAY
NIGHT INTO SUNDAY MORNING. ON SATURDAY...IT APPEARS THAT IF WE GET
ANY ACCUMULATIONS...THEY WOULD BE LIGHT AND MAINLY ON GRASSY AREAS
FOR OUR SOUTHERN ZONES. FARTHER NORTH...PCPN CHANCES WILL BE
INCREASING IN THE AFTERNOON BUT AMOUNTS WOULD BE LIGHTER. THE NAM
FORECAST SOUNDINGS STILL APPEARED TOO COLD...AND WENT CLOSER TO A
BLEND OF SOME OF THE OTHER MODELS...ESPECIALLY THE SREF. NORTH
WINDS WILL SPREAD ACROSS THE AREA SATURDAY NIGHT...AND AS THE
COLUMN COOLS...PCPN WILL CHANGE TO MOSTLY SNOW AND WILL START TO
ACCUMULATE. A SEPARATE SYSTEM WILL DROP QUICKLY SOUTHEAST IN THE
NORTHWEST FLOW SATURDAY NIGHT...PROVIDING GOOD LIFT IN A FAVORABLE
ENVIRONMENT FOR SNOW FROM THE NORTHERN PARTS OF NORTHEAST NEBRASKA
INTO WEST CENTRAL IOWA. INCREASED SNOW AMOUNTS FOR AREAS ALONG AND
NORTH OF HIGHWAY 20. IT APPEARS ANOTHER LOBE OF LIFT WILL DROP
DOWN OVER PARTS OF THE AREA SUNDAY AFTERNOON...SO KEPT SOME
MENTION OF LIGHT SNOW GOING UNTIL SUNDAY NIGHT. SUNDAY NIGHT IS
EXPECTED TO BE COLD WITH DECREASING CLOUDS AND DECREASING WINDS.
LOWS SHOULD DROP TO THE SINGLE DIGITS AND WE MAY SEE SOME BELOW
ZERO NUMBERS FROM HARTINGTON AND WAYNE TOWARD TEKAMAH AND HARLAN.
FAST NORTHWEST FLOW IN THE MID LEVELS WILL BE IN PLACE FOR MONDAY
AND IT DOES APPEAR THAT A SHORTWAVE TROUGH COULD MOVE THROUGH OUR
AREA. MODELS...ESPECIALLY THE 12Z GFS...BRING SOME LIGHT SNOW IN
FOR MONDAY AFTERNOON. COULD NOT ARGUE WITH THAT TOO MUCH SO WENT
WITH A SLIGHT CHANCE OF LIGHT SNOW FOR NOW AND WILL FINE TUNE THAT
LATER. MEASURABLE LIGHT AMOUNTS SEEM POSSIBLE...ESPECIALLY IN
WESTERN IOWA MONDAY. HIGHS MONDAY WILL BE MOSTLY 20S.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 310 PM CST FRI JAN 30 2015
SOME MILDER AIR WILL SPREAD IN BRIEFLY FOR TUESDAY...WITH HIGHS
REACHING THE UPPER 30S AND LOWER 40S. DID NOT WANT TO GET TOO
OPTIMISTIC AT THIS POINT FOR HIGHS. ANOTHER SURGE OF COLDER AIR
WILL DROP DOWN INTO THE AREA BY TUESDAY NIGHT. SOME LIGHT SNOW
SEEMS POSSIBLE BASED ON THE PATTERN...PLUS BOTH THE 12Z GFS AND
ECMWF SHOW A BIT OF SNOW.
TEMPERATURES WEDNESDAY AND THURSDAY WILL BE BELOW NORMAL...THEN
CLOSER TO NORMAL BY FRIDAY AS SOUTH OR SOUTHWEST WINDS INCREASE.
&&
.AVIATION...(00Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 522 PM CST FRI JAN 30 2015
VFR CONDITIONS BECOME MVFR THROUGH THE PERIOD WITH RAIN DEVELOPING
INITIALLY...THEN MIXING WITH OR CHANGING TO SNOW TOWARD THE END OF
THE PERIOD. COULD SEE RAIN CHANCES BEGIN IN THE KLNK AREA BY
10Z...AND 14-15Z AT KOMA/KOFK. SNOW CHANCES INCREASE BY 20-21Z.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
UPDATE...DEWALD
SHORT TERM...KERN/MILLER
LONG TERM...MILLER
AVIATION...DEWALD
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
526 PM CST FRI JAN 30 2015
.SHORT TERM...(TONIGHT THROUGH MONDAY)
ISSUED AT 310 PM CST FRI JAN 30 2015
PCPN TYPE AND PCPN AMOUNTS WILL BE THE MAIN CONCERN IN THIS PERIOD...
ESPECIALLY FROM LATE TONIGHT INTO SATURDAY EVENING. PCPN SHOULD TURN
TO MOSTLY SNOW BY LATE SATURDAY NIGHT ALL AREAS.
WATER VAPOR LOOP AND LATEST RAP MODEL INITIALIZATIONS SHOWED A
CLOSED LOW OVER THE CALIFORNIA/ARIZONA BORDER REGION EARLY THIS
AFTN. THIS WILL DROP SOUTHWARD INTO MEXICO THROUGH SUNDAY. SOME
SHORTWAVE ENERGY WILL MOVE NORTHEAST OUT OF THIS TROUGH THOUGH AND
MOVE UP INTO THE CENTRAL PLAINS LATER TONIGHT AND SATURDAY. SURFACE
ANALYSIS EARLY THIS AFTERNOON SHOWED MODEST SOUTH/SOUTHWEST WINDS
SPREADING ACROSS OUR AREA. CLOUDS WILL THICKEN AND LOWER...WITH
LIGHT PCPN PROBABLY MOVING INTO OUR SOUTHERN COUNTIES BEFORE 12Z.
HAVE LOWS FORECAST IN THE UPPER 20S NORTH AND LOWER 30S SOUTH. THE
PCPN TYPE MAY BE A MIX LATER TONIGHT INTO SATURDAY.
DID MAKE SOME MODIFICATIONS TO SNOW AMOUNTS...MAINLY FOR SATURDAY
NIGHT INTO SUNDAY MORNING. ON SATURDAY...IT APPEARS THAT IF WE GET
ANY ACCUMULATIONS...THEY WOULD BE LIGHT AND MAINLY ON GRASSY AREAS
FOR OUR SOUTHERN ZONES. FARTHER NORTH...PCPN CHANCES WILL BE
INCREASING IN THE AFTERNOON BUT AMOUNTS WOULD BE LIGHTER. THE NAM
FORECAST SOUNDINGS STILL APPEARED TOO COLD...AND WENT CLOSER TO A
BLEND OF SOME OF THE OTHER MODELS...ESPECIALLY THE SREF. NORTH
WINDS WILL SPREAD ACROSS THE AREA SATURDAY NIGHT...AND AS THE
COLUMN COOLS...PCPN WILL CHANGE TO MOSTLY SNOW AND WILL START TO
ACCUMULATE. A SEPARATE SYSTEM WILL DROP QUICKLY SOUTHEAST IN THE
NORTHWEST FLOW SATURDAY NIGHT...PROVIDING GOOD LIFT IN A FAVORABLE
ENVIRONMENT FOR SNOW FROM THE NORTHERN PARTS OF NORTHEAST NEBRASKA
INTO WEST CENTRAL IOWA. INCREASED SNOW AMOUNTS FOR AREAS ALONG AND
NORTH OF HIGHWAY 20. IT APPEARS ANOTHER LOBE OF LIFT WILL DROP
DOWN OVER PARTS OF THE AREA SUNDAY AFTERNOON...SO KEPT SOME
MENTION OF LIGHT SNOW GOING UNTIL SUNDAY NIGHT. SUNDAY NIGHT IS
EXPECTED TO BE COLD WITH DECREASING CLOUDS AND DECREASING WINDS.
LOWS SHOULD DROP TO THE SINGLE DIGITS AND WE MAY SEE SOME BELOW
ZERO NUMBERS FROM HARTINGTON AND WAYNE TOWARD TEKAMAH AND HARLAN.
FAST NORTHWEST FLOW IN THE MID LEVELS WILL BE IN PLACE FOR MONDAY
AND IT DOES APPEAR THAT A SHORTWAVE TROUGH COULD MOVE THROUGH OUR
AREA. MODELS...ESPECIALLY THE 12Z GFS...BRING SOME LIGHT SNOW IN
FOR MONDAY AFTERNOON. COULD NOT ARGUE WITH THAT TOO MUCH SO WENT
WITH A SLIGHT CHANCE OF LIGHT SNOW FOR NOW AND WILL FINE TUNE THAT
LATER. MEASURABLE LIGHT AMOUNTS SEEM POSSIBLE...ESPECIALLY IN
WESTERN IOWA MONDAY. HIGHS MONDAY WILL BE MOSTLY 20S.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 310 PM CST FRI JAN 30 2015
SOME MILDER AIR WILL SPREAD IN BRIEFLY FOR TUESDAY...WITH HIGHS
REACHING THE UPPER 30S AND LOWER 40S. DID NOT WANT TO GET TOO
OPTIMISTIC AT THIS POINT FOR HIGHS. ANOTHER SURGE OF COLDER AIR
WILL DROP DOWN INTO THE AREA BY TUESDAY NIGHT. SOME LIGHT SNOW
SEEMS POSSIBLE BASED ON THE PATTERN...PLUS BOTH THE 12Z GFS AND
ECMWF SHOW A BIT OF SNOW.
TEMPERATURES WEDNESDAY AND THURSDAY WILL BE BELOW NORMAL...THEN
CLOSER TO NORMAL BY FRIDAY AS SOUTH OR SOUTHWEST WINDS INCREASE.
&&
.AVIATION...(00Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 522 PM CST FRI JAN 30 2015
VFR CONDITIONS BECOME MVFR THROUGH THE PERIOD WITH RAIN DEVELOPING
INITIALLY...THEN MIXING WITH OR CHANGING TO SNOW TOWARD THE END OF
THE PERIOD. COULD SEE RAIN CHANCES BEGIN IN THE KLNK AREA BY
10Z...AND 14-15Z AT KOMA/KOFK. SNOW CHANCES INCREASE BY 20-21Z.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...KERN/MILLER
LONG TERM...MILLER
AVIATION...DEWALD
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1132 AM CST THU JAN 29 2015
.UPDATE...
ISSUED AT 1132 AM CST THU JAN 29 2015
CLOUDS HAVE BEEN DIMINISHING IN COVERAGE ACROSS NORTH CENTRAL AND
CENTRAL NEBRASKA THROUGH THIS MORNING AS WARM AIR BUILDS IN ALOFT
AND THE BOUNDARY LAYER MIXES. THE CLOUDS KEPT TEMPERATURES FROM
DROPPING OVERNIGHT...AND WITH THE SUNSHINE ACROSS THE
WEST WARMING THOSE AREAS...TEMPERATURES ARE FAIRLY SIMILAR ACROSS
THE ENTIRE FORECAST AREA. MIXING TO 850MB CONTINUES TO LOOK LIKELY
THROUGH THE AFTERNOON AND WITH TEMPERATURES AT THAT LEVEL
INCREASING THE ONGOING FORECAST OF NEAR 40 TO MID 40S STILL LOOKS
GOOD.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 359 AM CST THU JAN 29 2015
SFC OBS INDICATE CEILINGS ARE RISING ACROSS
NCNTL NEB. THE CLOUDS ARE ASSOCIATED WITH COLD AIR ADVECTION WHICH
THE NAM AND RAP MODELS SHOW WEAKENING THIS MORNING 15Z-18Z. THUS WE
SHOULD SEE A CONTINUED EROSION OF THE CLOUD COVER WITH MOSTLY SUNNY
SKIES FROM 18Z ONWARD.
THE MODEL CONSENSUS SUGGESTS HIGHS IN THE 40S TODAY. THE TEMPERATURE
FORECAST IS CLOSE TO RAP MODEL WHICH GENERALLY WORKS WELL IN CLEAR
SKY CONDITIONS.
TONIGHT...HIGH PRESSURE WILL MOVE OFF SLOWLY EAST WITH SOUTH WINDS
DEVELOPING ACROSS THE PANHANDLE FROM 03Z ONWARD AND SPREADING SLOWLY
EAST OVERNIGHT. THE COLDEST READINGS SHOULD OCCUR ALONG AND EAST OF
HIGHWAY 83 WHERE WINDS WILL REMAIN LIGHT AND VARIABLE MOST OF THE
NIGHT.
WINDS TODAY SHOULD CONTINUE TO DECREASE FROM WEST TO EAST. THE RAP
MODEL INDICATES NORTH WINDS AT JUST 10 TO 15 MPH BY 3 PM THIS AFTN
AS PACIFIC HIGH PRESSURE BUILDS INTO WRN NEB.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 359 AM CST THU JAN 29 2015
A WEAKENING UPPER LEVEL RIDGE WILL TRANSLATE EAST ACROSS THE CENTRAL
PORTIONS OF THE UNITED STATES FRIDAY. MILD PACIFIC AIR WILL
ACCOMPANY THE RIDGING...WITH H850MB TEMPERATURES RANGING FROM
2C TO 4C ACROSS THE AREA. THE DAY WILL START SUNNY...BUT SOME
INCREASE IN HIGH CLOUDINESS EXPECTED BY LATER IN THE DAY AS SUB
TROPICAL MOISTURE BEGINS TO APPROACH THE AREA FROM THE SOUTHWEST.
WITH THE MILD AIR IN PLACE AND EXPECTED SUN...WILL RAISE HIGHS A FEW
DEGREES INTO THE MID 40S TO LOWER 50S.
STILL LOOKS INTERESTING FRIDAY NIGHT THROUGH SATURDAY NIGHT. A
LARGE PLUMB OF SUB TROPICAL MOISTURE...ORIGINATING OFF THE WEST
COAST OF MEXICO...WILL BE DRAWN NORTHWARD INTO THE SOUTHERN AND
POSSIBLY CENTRAL PLAINS AHEAD OF AN UPPER LEVEL TROUGH THAT WILL
MOVE INTO THE DESERT SOUTHWEST/WESTERN CONUS BY FRIDAY EVENING. AT
THE SAME TIME...A NORTHERN STREAM SHORTWAVE WILL BE MOVING INTO
BRITISH COLUMBIA FROM THE GULF OF ALASKA. MODELS HAVE BEEN
STRUGGLING WITH THE NORTHERN STREAM FEATURE...WITH SOME MODEL RUNS
STRONGER AND MORE AMPLIFIED WITH THE SHORTWAVE...AND OTHERS WEAKER
AND MORE SHEARED. THE LATEST 29/00Z RUN OF THE ECMWF SUPPORTS A
WEAKER...FASTER AND MORE SHEARED SHORTWAVE...WITH THE GFS A BIT
SLOWER AND MORE AMPLIFIED...AND THE NAM BEING THE MOST AMPLIFIED AND
SLOWEST OF ALL. HOW THE NORTHERN STREAM SYSTEM INTERACTS WITH THE
SUB TROPICAL MOISTURE REMAINS IN QUESTION. A SLOWER MORE AMPLIFIED
SCENARIO WOULD PULL MOISTURE FARTHER NORTH THOUGH THE FORECAST
AREA...WHILE A FASTER MORE SHEARED SCENARIO WOULD TEND TO SHUNT MUCH
OF THE SUB TROPICAL MOISTURE OFF TO THE EAST. THE SLOWER MORE
AMPLIFIED NAM WOULD FAVOR BETTER CHANCES FOR SNOW...WHILE THE GFS
AND ESPECIALLY THE ECMWF WOULD NOT. DUE TO THE WOBBLING OF THE
MODELS IN REGARDS TO THE NORTHERN STREAM...WILL ONLY MAKE SLIGHT
ADJUSTMENTS TO THE CURRENT POP FORECAST. WILL MAINTAIN THE LOW
CHANCE POPS ACROSS CENTRAL AND PORTIONS OF NORTH CENTRAL
NEBRASKA...WITH A DECREASE TO JUST SLIGHT CHANCES FARTHER WEST.
NORTHERN STREAM ENERGY IS QUITE DIFFICULT TO FORECAST...AND EXPECT
THAT MODELS WILL CONTINUE TO WOBBLE SOME UNTIL THE FEATURE IS
ONSHORE FRIDAY.
AS THE NORTHERN STREAM ENERGY PASSES...EXPECT A BATCH OF ARCTIC AIR
TO PUSH SOUTH INTO THE CENTRAL AND NORTHERN PLAINS IN IT/S WAKE
SUNDAY. UPPER FLOW QUICKLY BECOMES MORE ZONAL MONDAY...WITH PACIFIC
AIR SPREADING BACK INTO THE REGION FROM THE WEST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1132 AM CST THU JAN 29 2015
VFR CONDITIONS WILL PERSIST THROUGH FRIDAY AFTERNOON AS MVFR
CEILINGS HAVE SCATTERED OUT BY LATE THIS MORNING. THE FORECAST
DOES HAVE A TREND SHOWING CHANGING WIND CONDITIONS AS THE CURRENT
BREEZY NORTHWEST WINDS DIMINISH NEAR MID AFTERNOON AS HIGH
PRESSURE BUILDS IN. NEAR SUNSET THE BOUNDARY LAYER WILL DECOUPLE
LEADING TO LIGHT WINDS WHICH WILL BE VARIABLE AND EVENTUALLY SHIFT
AROUND TO THE SOUTH OVERNIGHT. THE WINDS WILL INCREASE TO AROUND
12KTS LATE FRIDAY MORNING.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BROOKS
SHORT TERM...CDC
LONG TERM...TAYLOR
AVIATION...BROOKS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1125 AM CST THU JAN 29 2015
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 312 AM CST THU JAN 29 2015
EXTENSIVE LOW CLOUD LAYER HAD OVERSPREAD EASTERN NEBRASKA AND
SOUTHWEST IOWA EARLY THIS MORNING. HRRR SUGGESTS CLOUDS WILL
LIKELY HANG TOUGH THROUGH THE MORNING BEFORE BREAKING UP FROM WEST
TO EAST DURING THE EARLY AFTERNOON. GUSTY NORTHWEST WINDS ALSO
EXPECTED TO CONTINUE INTO THE MORNING ALTHOUGH LATEST TREND
APPEARS TO BE A DECREASE FROM NORTH TO SOUTH THROUGH 12Z. WILL
ADD REMAINING SOUTHERN COUNTIES TO ADVISORY THROUGH EXPIRATION AT
7 AM. HIGH PRESSURE RIDGE THEN SETTLES OVER THE AREA TONIGHT
BEFORE MOVING EAST ON FRIDAY.
NEXT FORECAST CONCERN DEVELOPS FRIDAY NIGHT AND SATURDAY AS A COLD
FRONT MOVES INTO THE AREA FROM THE NORTH WHILE LOW LEVEL WARM
ADVECTION MOVES IN FROM THE SOUTH IN ADVANCE OF CLOSED UPPER LOW
OVER THE SOUTHWEST PART OF THE COUNTRY. LATEST MODEL SOLUTIONS
INDICATE AN AREA OF LIGHT PRECIP SPREADING INTO THE SOUTH HALF OF
THE FORECAST AREA BY SATURDAY MORNING THEN LINGERS THROUGH
SATURDAY NIGHT.
AT THIS TIME IT APPEARS NORTHERN PARTS OF THE AREA SHOULD STAY DRY
FOR THE MOST PART. DRIER AIR COMING IN WITH NEXT BATCH OF COLD AIR
LOOKS TO LIMIT NORTHERN EXTENT OF PRECIP WITH A SHARP CUTOFF
ACROSS EAST CENTRAL NEBRASKA AND WEST CENTRAL IOWA. PRECIP LIKELY
TO START OFF AS LIQUID ALONG THE SOUTHEAST BORDER AREA LATE FRIDAY
NIGHT THEN TRANSITION TO LIGHT SNOW DURING THE DAY SATURDAY AS THE
COLD AIR DEEPENS BEHIND THE FRONT. SOME LIGHT SNOW ACCUMULATION IN
THE 1 TO 2 INCH RANGE POSSIBLE BY SUNDAY MORNING ACROSS SOUTHEAST
NEBRASKA INTO SOUTHWEST IOWA WITH UPPER BOUND NEAR SOUTHERN BORDER
OF NEBRASKA AND SOUTHWEST IOWA.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 312 AM CST THU JAN 29 2015
MUCH COLDER AIR MOVES IN ON SUNDAY AS THE SOUTHERN PLAINS WEATHER
SYSTEM MOVES EAST AND HIGH PRESSURE BUILDS INTO THE CENTRAL
PLAINS. COLDEST AIR HANGS AROUND THROUGH MONDAY BEFORE SOME
MODERATION RETURNS AS ANOTHER CLIPPER MOVES INTO THE REGION MONDAY
NIGHT. MORE COLD AIR FOLLOWS BEHIND THE CLIPPER FOR TUESDAY INTO
WEDNESDAY ALONG WITH ANOTHER POTENTIAL FOR LIGHT SNOW AS
BAROCLINIC ZONE DEVELOPS IN THE AREA.
&&
.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1117 AM CST THU JAN 29 2015
MVFR CONDITIONS ARE EXPECTED FOR THE FIRST FEW HOURS OF THE TAF
CYCLE. SKIES WILL CLEAR THIS AFTERNOON AND NORTHWEST SFC WINDS
WILL DIMINISH AND BECOME LIGHT AND VARIABLE OVERNIGHT. SOUTHWEST
SFC WINDS WILL THEN INCREASE FRIDAY MORNING.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...FOBERT
LONG TERM...FOBERT
AVIATION...KERN
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
529 AM CST THU JAN 29 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 359 AM CST THU JAN 29 2015
SFC OBS INDICATE CEILINGS ARE RISING ACROSS
NCNTL NEB. THE CLOUDS ARE ASSOCIATED WITH COLD AIR ADVECTION WHICH
THE NAM AND RAP MODELS SHOW WEAKENING THIS MORNING 15Z-18Z. THUS WE
SHOULD SEE A CONTINUED EROSION OF THE CLOUD COVER WITH MOSTLY SUNNY
SKIES FROM 18Z ONWARD.
THE MODEL CONSENSUS SUGGESTS HIGHS IN THE 40S TODAY. THE TEMPERATURE
FORECAST IS CLOSE TO RAP MODEL WHICH GENERALLY WORKS WELL IN CLEAR
SKY CONDITIONS.
TONIGHT...HIGH PRESSURE WILL MOVE OFF SLOWLY EAST WITH SOUTH WINDS
DEVELOPING ACROSS THE PANHANDLE FROM 03Z ONWARD AND SPREADING SLOWLY
EAST OVERNIGHT. THE COLDEST READINGS SHOULD OCCUR ALONG AND EAST OF
HIGHWAY 83 WHERE WINDS WILL REMAIN LIGHT AND VARIABLE MOST OF THE
NIGHT.
WINDS TODAY SHOULD CONTINUE TO DECREASE FROM WEST TO EAST. THE RAP
MODEL INDICATES NORTH WINDS AT JUST 10 TO 15 MPH BY 3 PM THIS AFTN
AS PACIFIC HIGH PRESSURE BUILDS INTO WRN NEB.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 359 AM CST THU JAN 29 2015
A WEAKENING UPPER LEVEL RIDGE WILL TRANSLATE EAST ACROSS THE CENTRAL
PORTIONS OF THE UNITED STATES FRIDAY. MILD PACIFIC AIR WILL
ACCOMPANY THE RIDGING...WITH H850MB TEMPERATURES RANGING FROM
2C TO 4C ACROSS THE AREA. THE DAY WILL START SUNNY...BUT SOME
INCREASE IN HIGH CLOUDINESS EXPECTED BY LATER IN THE DAY AS SUB
TROPICAL MOISTURE BEGINS TO APPROACH THE AREA FROM THE SOUTHWEST.
WITH THE MILD AIR IN PLACE AND EXPECTED SUN...WILL RAISE HIGHS A FEW
DEGREES INTO THE MID 40S TO LOWER 50S.
STILL LOOKS INTERESTING FRIDAY NIGHT THROUGH SATURDAY NIGHT. A
LARGE PLUMB OF SUB TROPICAL MOISTURE...ORIGINATING OFF THE WEST
COAST OF MEXICO...WILL BE DRAWN NORTHWARD INTO THE SOUTHERN AND
POSSIBLY CENTRAL PLAINS AHEAD OF AN UPPER LEVEL TROUGH THAT WILL
MOVE INTO THE DESERT SOUTHWEST/WESTERN CONUS BY FRIDAY EVENING. AT
THE SAME TIME...A NORTHERN STREAM SHORTWAVE WILL BE MOVING INTO
BRITISH COLUMBIA FROM THE GULF OF ALASKA. MODELS HAVE BEEN
STRUGGLING WITH THE NORTHERN STREAM FEATURE...WITH SOME MODEL RUNS
STRONGER AND MORE AMPLIFIED WITH THE SHORTWAVE...AND OTHERS WEAKER
AND MORE SHEARED. THE LATEST 29/00Z RUN OF THE ECMWF SUPPORTS A
WEAKER...FASTER AND MORE SHEARED SHORTWAVE...WITH THE GFS A BIT
SLOWER AND MORE AMPLIFIED...AND THE NAM BEING THE MOST AMPLIFIED AND
SLOWEST OF ALL. HOW THE NORTHERN STREAM SYSTEM INTERACTS WITH THE
SUB TROPICAL MOISTURE REMAINS IN QUESTION. A SLOWER MORE AMPLIFIED
SCENARIO WOULD PULL MOISTURE FARTHER NORTH THOUGH THE FORECAST
AREA...WHILE A FASTER MORE SHEARED SCENARIO WOULD TEND TO SHUNT MUCH
OF THE SUB TROPICAL MOISTURE OFF TO THE EAST. THE SLOWER MORE
AMPLIFIED NAM WOULD FAVOR BETTER CHANCES FOR SNOW...WHILE THE GFS
AND ESPECIALLY THE ECMWF WOULD NOT. DUE TO THE WOBBLING OF THE
MODELS IN REGARDS TO THE NORTHERN STREAM...WILL ONLY MAKE SLIGHT
ADJUSTMENTS TO THE CURRENT POP FORECAST. WILL MAINTAIN THE LOW
CHANCE POPS ACROSS CENTRAL AND PORTIONS OF NORTH CENTRAL
NEBRASKA...WITH A DECREASE TO JUST SLIGHT CHANCES FARTHER WEST.
NORTHERN STREAM ENERGY IS QUITE DIFFICULT TO FORECAST...AND EXPECT
THAT MODELS WILL CONTINUE TO WOBBLE SOME UNTIL THE FEATURE IS
ONSHORE FRIDAY.
AS THE NORTHERN STREAM ENERGY PASSES...EXPECT A BATCH OF ARCTIC AIR
TO PUSH SOUTH INTO THE CENTRAL AND NORTHERN PLAINS IN IT/S WAKE
SUNDAY. UPPER FLOW QUICKLY BECOMES MORE ZONAL MONDAY...WITH PACIFIC
AIR SPREADING BACK INTO THE REGION FROM THE WEST.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 529 AM CST THU JAN 29 2015
THE AREA OF MVFR CIGS GENERALLY EAST OF HIGHWAY 83 IS EXPECTED TO
DRIFT EAST THIS MORNING AND THEN MIX OUT TO VFR CIGS BEFORE
COMPLETELY ERODING AROUND 18Z. VFR IS EXPECTED ALL AREAS
THEREAFTER THIS AFTN AND TONIGHT.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...TAYLOR
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
515 AM CST THU JAN 29 2015
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 312 AM CST THU JAN 29 2015
EXTENSIVE LOW CLOUD LAYER HAD OVERSPREAD EASTERN NEBRASKA AND
SOUTHWEST IOWA EARLY THIS MORNING. HRRR SUGGESTS CLOUDS WILL
LIKELY HANG TOUGH THROUGH THE MORNING BEFORE BREAKING UP FROM WEST
TO EAST DURING THE EARLY AFTERNOON. GUSTY NORTHWEST WINDS ALSO
EXPECTED TO CONTINUE INTO THE MORNING ALTHOUGH LATEST TREND
APPEARS TO BE A DECREASE FROM NORTH TO SOUTH THROUGH 12Z. WILL
ADD REMAINING SOUTHERN COUNTIES TO ADVISORY THROUGH EXPIRATION AT
7 AM. HIGH PRESSURE RIDGE THEN SETTLES OVER THE AREA TONIGHT
BEFORE MOVING EAST ON FRIDAY.
NEXT FORECAST CONCERN DEVELOPS FRIDAY NIGHT AND SATURDAY AS A COLD
FRONT MOVES INTO THE AREA FROM THE NORTH WHILE LOW LEVEL WARM
ADVECTION MOVES IN FROM THE SOUTH IN ADVANCE OF CLOSED UPPER LOW
OVER THE SOUTHWEST PART OF THE COUNTRY. LATEST MODEL SOLUTIONS
INDICATE AN AREA OF LIGHT PRECIP SPREADING INTO THE SOUTH HALF OF
THE FORECAST AREA BY SATURDAY MORNING THEN LINGERS THROUGH
SATURDAY NIGHT.
AT THIS TIME IT APPEARS NORTHERN PARTS OF THE AREA SHOULD STAY DRY
FOR THE MOST PART. DRIER AIR COMING IN WITH NEXT BATCH OF COLD AIR
LOOKS TO LIMIT NORTHERN EXTENT OF PRECIP WITH A SHARP CUTOFF
ACROSS EAST CENTRAL NEBRASKA AND WEST CENTRAL IOWA. PRECIP LIKELY
TO START OFF AS LIQUID ALONG THE SOUTHEAST BORDER AREA LATE FRIDAY
NIGHT THEN TRANSITION TO LIGHT SNOW DURING THE DAY SATURDAY AS THE
COLD AIR DEEPENS BEHIND THE FRONT. SOME LIGHT SNOW ACCUMULATION IN
THE 1 TO 2 INCH RANGE POSSIBLE BY SUNDAY MORNING ACROSS SOUTHEAST
NEBRASKA INTO SOUTHWEST IOWA WITH UPPER BOUND NEAR SOUTHERN BORDER
OF NEBRASKA AND SOUTHWEST IOWA.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 312 AM CST THU JAN 29 2015
MUCH COLDER AIR MOVES IN ON SUNDAY AS THE SOUTHERN PLAINS WEATHER
SYSTEM MOVES EAST AND HIGH PRESSURE BUILDS INTO THE CENTRAL
PLAINS. COLDEST AIR HANGS AROUND THROUGH MONDAY BEFORE SOME
MODERATION RETURNS AS ANOTHER CLIPPER MOVES INTO THE REGION MONDAY
NIGHT. MORE COLD AIR FOLLOWS BEHIND THE CLIPPER FOR TUESDAY INTO
WEDNESDAY ALONG WITH ANOTHER POTENTIAL FOR LIGHT SNOW AS
BAROCLINIC ZONE DEVELOPS IN THE AREA.
&&
.AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 509 AM CST THU JAN 29 2015
MVFR CONDITIONS EARLY IN THE PERIOD...BUT SCATTERING OUT TO VFR BY
18-20Z. VERY STRONG NORTHWEST WINDS 22 TO 32 KNOTS EARLY...WITH
GUSTS DIMINISHING BY 20-23Z...THEN BECOMING LIGHT AND VARIABLE BY
00-02Z.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WIND ADVISORY UNTIL 7 AM CST THIS MORNING FOR NEZ015-030>034-
042>045-050>053-065>068-078-088>093.
WIND ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR NEZ011-012-
016>018.
IA...WIND ADVISORY UNTIL 7 AM CST THIS MORNING FOR IAZ043-055-056-069-
079-080-090-091.
&&
$$
SHORT TERM...FOBERT
LONG TERM...FOBERT
AVIATION...DEWALD
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
400 AM CST THU JAN 29 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 359 AM CST THU JAN 29 2015
SFC OBS INDICATE CEILINGS ARE RISING ACROSS
NCNTL NEB. THE CLOUDS ARE ASSOCIATED WITH COLD AIR ADVECTION WHICH
THE NAM AND RAP MODELS SHOW WEAKENING THIS MORNING 15Z-18Z. THUS WE
SHOULD SEE A CONTINUED EROSION OF THE CLOUD COVER WITH MOSTLY SUNNY
SKIES FROM 18Z ONWARD.
THE MODEL CONSENSUS SUGGESTS HIGHS IN THE 40S TODAY. THE TEMPERATURE
FORECAST IS CLOSE TO RAP MODEL WHICH GENERALLY WORKS WELL IN CLEAR
SKY CONDITIONS.
TONIGHT...HIGH PRESSURE WILL MOVE OFF SLOWLY EAST WITH SOUTH WINDS
DEVELOPING ACROSS THE PANHANDLE FROM 03Z ONWARD AND SPREADING SLOWLY
EAST OVERNIGHT. THE COLDEST READINGS SHOULD OCCUR ALONG AND EAST OF
HIGHWAY 83 WHERE WINDS WILL REMAIN LIGHT AND VARIABLE MOST OF THE
NIGHT.
WINDS TODAY SHOULD CONTINUE TO DECREASE FROM WEST TO EAST. THE RAP
MODEL INDICATES NORTH WINDS AT JUST 10 TO 15 MPH BY 3 PM THIS AFTN
AS PACIFIC HIGH PRESSURE BUILDS INTO WRN NEB.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 359 AM CST THU JAN 29 2015
A WEAKENING UPPER LEVEL RIDGE WILL TRANSLATE EAST ACROSS THE CENTRAL
PORTIONS OF THE UNITED STATES FRIDAY. MILD PACIFIC AIR WILL
ACCOMPANY THE RIDGING...WITH H850MB TEMPERATURES RANGING FROM
2C TO 4C ACROSS THE AREA. THE DAY WILL START SUNNY...BUT SOME
INCREASE IN HIGH CLOUDINESS EXPECTED BY LATER IN THE DAY AS SUB
TROPICAL MOISTURE BEGINS TO APPROACH THE AREA FROM THE SOUTHWEST.
WITH THE MILD AIR IN PLACE AND EXPECTED SUN...WILL RAISE HIGHS A FEW
DEGREES INTO THE MID 40S TO LOWER 50S.
STILL LOOKS INTERESTING FRIDAY NIGHT THROUGH SATURDAY NIGHT. A
LARGE PLUMB OF SUB TROPICAL MOISTURE...ORIGINATING OFF THE WEST
COAST OF MEXICO...WILL BE DRAWN NORTHWARD INTO THE SOUTHERN AND
POSSIBLY CENTRAL PLAINS AHEAD OF AN UPPER LEVEL TROUGH THAT WILL
MOVE INTO THE DESERT SOUTHWEST/WESTERN CONUS BY FRIDAY EVENING. AT
THE SAME TIME...A NORTHERN STREAM SHORTWAVE WILL BE MOVING INTO
BRITISH COLUMBIA FROM THE GULF OF ALASKA. MODELS HAVE BEEN
STRUGGLING WITH THE NORTHERN STREAM FEATURE...WITH SOME MODEL RUNS
STRONGER AND MORE AMPLIFIED WITH THE SHORTWAVE...AND OTHERS WEAKER
AND MORE SHEARED. THE LATEST 29/00Z RUN OF THE ECMWF SUPPORTS A
WEAKER...FASTER AND MORE SHEARED SHORTWAVE...WITH THE GFS A BIT
SLOWER AND MORE AMPLIFIED...AND THE NAM BEING THE MOST AMPLIFIED AND
SLOWEST OF ALL. HOW THE NORTHERN STREAM SYSTEM INTERACTS WITH THE
SUB TROPICAL MOISTURE REMAINS IN QUESTION. A SLOWER MORE AMPLIFIED
SCENARIO WOULD PULL MOISTURE FARTHER NORTH THOUGH THE FORECAST
AREA...WHILE A FASTER MORE SHEARED SCENARIO WOULD TEND TO SHUNT MUCH
OF THE SUB TROPICAL MOISTURE OFF TO THE EAST. THE SLOWER MORE
AMPLIFIED NAM WOULD FAVOR BETTER CHANCES FOR SNOW...WHILE THE GFS
AND ESPECIALLY THE ECMWF WOULD NOT. DUE TO THE WOBBLING OF THE
MODELS IN REGARDS TO THE NORTHERN STREAM...WILL ONLY MAKE SLIGHT
ADJUSTMENTS TO THE CURRENT POP FORECAST. WILL MAINTAIN THE LOW
CHANCE POPS ACROSS CENTRAL AND PORTIONS OF NORTH CENTRAL
NEBRASKA...WITH A DECREASE TO JUST SLIGHT CHANCES FARTHER WEST.
NORTHERN STREAM ENERGY IS QUITE DIFFICULT TO FORECAST...AND EXPECT
THAT MODELS WILL CONTINUE TO WOBBLE SOME UNTIL THE FEATURE IS
ONSHORE FRIDAY.
AS THE NORTHERN STREAM ENERGY PASSES...EXPECT A BATCH OF ARCTIC AIR
TO PUSH SOUTH INTO THE CENTRAL AND NORTHERN PLAINS IN IT/S WAKE
SUNDAY. UPPER FLOW QUICKLY BECOMES MORE ZONAL MONDAY...WITH PACIFIC
AIR SPREADING BACK INTO THE REGION FROM THE WEST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1121 PM CST WED JAN 28 2015
WINDY CONDITIONS WILL PERSIST PRIOR TO 12Z...THEN DIMINISH
THURSDAY MORNING. MVFR STRATUS WILL BE OBSERVED ACROSS THE AREA
OVERNIGHT...WHICH LOOKS TO MIX OUT MID TO LATE THURSDAY MORNING AT
THE KLBF AND KVTN TERMINALS.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...TAYLOR
AVIATION...ROBERG
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
316 AM CST THU JAN 29 2015
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 312 AM CST THU JAN 29 2015
EXTENSIVE LOW CLOUD LAYER HAD OVERSPREAD EASTERN NEBRASKA AND
SOUTHWEST IOWA EARLY THIS MORNING. HRRR SUGGESTS CLOUDS WILL
LIKELY HANG TOUGH THROUGH THE MORNING BEFORE BREAKING UP FROM WEST
TO EAST DURING THE EARLY AFTERNOON. GUSTY NORTHWEST WINDS ALSO
EXPECTED TO CONTINUE INTO THE MORNING ALTHOUGH LATEST TREND
APPEARS TO BE A DECREASE FROM NORTH TO SOUTH THROUGH 12Z. WILL
ADD REMAINING SOUTHERN COUNTIES TO ADVISORY THROUGH EXPIRATION AT
7 AM. HIGH PRESSURE RIDGE THEN SETTLES OVER THE AREA TONIGHT
BEFORE MOVING EAST ON FRIDAY.
NEXT FORECAST CONCERN DEVELOPS FRIDAY NIGHT AND SATURDAY AS A COLD
FRONT MOVES INTO THE AREA FROM THE NORTH WHILE LOW LEVEL WARM
ADVECTION MOVES IN FROM THE SOUTH IN ADVANCE OF CLOSED UPPER LOW
OVER THE SOUTHWEST PART OF THE COUNTRY. LATEST MODEL SOLUTIONS
INDICATE AN AREA OF LIGHT PRECIP SPREADING INTO THE SOUTH HALF OF
THE FORECAST AREA BY SATURDAY MORNING THEN LINGERS THROUGH
SATURDAY NIGHT.
AT THIS TIME IT APPEARS NORTHERN PARTS OF THE AREA SHOULD STAY DRY
FOR THE MOST PART. DRIER AIR COMING IN WITH NEXT BATCH OF COLD AIR
LOOKS TO LIMIT NORTHERN EXTENT OF PRECIP WITH A SHARP CUTOFF
ACROSS EAST CENTRAL NEBRASKA AND WEST CENTRAL IOWA. PRECIP LIKELY
TO START OFF AS LIQUID ALONG THE SOUTHEAST BORDER AREA LATE FRIDAY
NIGHT THEN TRANSITION TO LIGHT SNOW DURING THE DAY SATURDAY AS THE
COLD AIR DEEPENS BEHIND THE FRONT. SOME LIGHT SNOW ACCUMULATION IN
THE 1 TO 2 INCH RANGE POSSIBLE BY SUNDAY MORNING ACROSS SOUTHEAST
NEBRASKA INTO SOUTHWEST IOWA WITH UPPER BOUND NEAR SOUTHERN BORDER
OF NEBRASKA AND SOUTHWEST IOWA.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 312 AM CST THU JAN 29 2015
MUCH COLDER AIR MOVES IN ON SUNDAY AS THE SOUTHERN PLAINS WEATHER
SYSTEM MOVES EAST AND HIGH PRESSURE BUILDS INTO THE CENTRAL
PLAINS. COLDEST AIR HANGS AROUND THROUGH MONDAY BEFORE SOME
MODERATION RETURNS AS ANOTHER CLIPPER MOVES INTO THE REGION MONDAY
NIGHT. MORE COLD AIR FOLLOWS BEHIND THE CLIPPER FOR TUESDAY INTO
WEDNESDAY ALONG WITH ANOTHER POTENTIAL FOR LIGHT SNOW AS
BAROCLINIC ZONE DEVELOPS IN THE AREA.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1141 PM CST WED JAN 28 2015
MVFR CONDITIONS HAVE OVERSPREAD THE AREA AND SHOULD LAST INTO
THURSDAY MORNING. SPRINKLES WILL BE POSSIBLE...BUT NOT
SIGNIFICANT ENOUGH TO MENTION. NORTHWEST WINDS 20 TO 30KTS WITH
GUSTS 30 TO 40KTS TONIGHT. THE NORTHWEST WINDS SHOULD DROP OFF
THURSDAY AS THE STRONGER WINDS ALOFT SHIFT TO THE EAST...GENERALLY
DROPPING TO UNDER 15KTS THURSDAY AFTERNOON AND UNDER 10KTS
THURSDAY NIGHT.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WIND ADVISORY UNTIL 7 AM CST THIS MORNING FOR NEZ015-030>034-
042>045-050>053-065>068-078-088>093.
WIND ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR NEZ011-012-
016>018.
IA...WIND ADVISORY UNTIL 7 AM CST THIS MORNING FOR IAZ043-055-056-069-
079-080-090-091.
&&
$$
SHORT TERM...FOBERT
LONG TERM...FOBERT
AVIATION...ZAPOTOCNY
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
948 PM EST FRI JAN 30 2015
.SYNOPSIS...
VERY COLD AIR WILL CONTINUE TO POUR INTO THE REGION TONIGHT...WITH
LAKE-EFFECT SNOW PERSISTING DOWNWIND FROM THE FINGER LAKES...AND
BITTERLY COLD WIND CHILLS AREA-WIDE. COLD TEMPERATURES WILL LAST
THROUGH THE UPCOMING WEEKEND...WITH ONLY A FEW FLURRIES FORESEEN
FROM SATURDAY INTO EARLY SUNDAY. AN APPROACHING WINTER STORM COULD
BEGIN TO IMPACT THE AREA BY LATE SUNDAY AFTERNOON OR SUNDAY
EVENING...WITH ACCUMULATING SNOW POSSIBLE.
&&
.NEAR TERM /THROUGH SATURDAY/...
945 PM UPDATE...
LAKE EFFECT SNOW CONTINUES DOWNWIND OF THE FINGER LAKES. RADAR
INTENSITY DOES NOT LOOK THAT STRONG BUT WITH SURFACE TEMPS THIS
COLD, FLUFF FACTOR IS PROBABLY IN FULL FORCE. ADVISORY THROUGH 1
AM LOOKS GOOD WITH ANOTHER INCH OR TWO POSSIBLE IN THE MOST
PERSISTENT BANDS. WIND CHILL VALUES ARE ALREADY IN THE -5 TO -10
RANGE AND EXPECTED TO DROP FURTHER OVERNIGHT, SO THE WIND CHILL
ADVISORY LOOKS GOOD. A QUICK MENTION OF THE POTENTIAL SNOW FOR
SUNDAY NIGHT INTO MONDAY. WE PUT A GRAPHIC ON SOCIAL MEDIA
(TWITTER/FACEBOOK) TO SHOW THE HIGHEST THREAT FOR SNOW AT THIS
POINT. PREVIOUS AFD IS BELOW.
145 PM UPDATE... ONLY MINOR TWEAKS MADE TO THE GRIDS THIS PD.
AREA-WIDE WIND CHILL ADVSY STILL LOOKS ON TRACK FOR THE OVERNIGHT
HRS...AS VERY STG 925-850 MB CAA THROUGH THIS EVE...SHOULD SEND
AIR TEMPS INTO THE SINGLE DIGITS ABV OR BLO ZERO TNT...WITH THE
PRES GRADIENT REMAINING RELATIVELY TIGHT THIS EVE...AND ONLY
SLOWLY RELAXING LATE. MOST AREAS SHOULD SEE APPARENT TEMPS IN THE
-10 TO -20 RANGE...WITH LOCALLY COLDER VALUES IN OUR FAR NRN AND
ERN ZNS.
AS FAR AS THE LES ADVSY GOES...NO CHGS ATTM. ALTHOUGH BLYR INSTAB
(TERRESTRIAL CAPE VALUES OF 15-30 J/KG) TEMPORARILY RESULTED IN A
MORE CELLULAR APPEARANCE TO THE SNOW SHWRS EARLIER THIS AFTN
LOW-LVL STABILIZATION AND INCRG SHEAR SHOULD RESULT IN THE RE-
EMERGENCE OF WELL DEFINED BANDS BY 21Z OR SO. IN FACT...EVIDENCE
OF SUCH IS ALREADY SEEN ON KBGM RADAR IMAGERY ATTM. MOST HI-RES
MODEL GUIDANCE HINTS THAT MULTI-BANDS/FINGER LKS BANDS WILL REMAIN
AT PLAY TIL AT LEAST 06-12Z SAT. OVERALL...INTENSITY SHOULD WANE
AFTER 06Z...AS MODEL SNDGS SHOW THE CAPPING INVERSION LWRG TO AOB
875-900 MB. WE`LL STICK WITH OUR 3-6" TOTALS FOR NOW...ALTHOUGH
WUDN`T BE SURPRISED TO SEE LOCALLY HIER AMTS...SPCLY IN SERN
TOMPKINS AND/OR NRN TIOGA.
OUTSIDE OF MULTI-BAND AREAS...EITHER WIDELY SCTD -SHSN/FLRYS...OR
JUST DRY WX...IS FORESEEN.
PREV DISC... 10 AM UPDATE... WE`VE ISSUED A LES ADVSY FOR
TOMPKINS...TIOGA...BROOME...AND SUSQ CNTYS...AS CONFIDENCE HAS
BECOME FAIRLY HIGH IN THE MAINTENANCE OF A WELL DVLPD FINGER LKS
BAND...THROUGH AT LEAST 00-03Z THIS EVE. OUR FIRST STAB AT SNOW
TOTALS IS 3-6"...BUT LOCALLY HIER AMTS ARE CERTAINLY PSBL.
NO OTHER SIG CHGS ATTM.
EARLIER DISC... 830 AM UPDATE... SN/+SN IS BEING OBSERVED ATTM
WITHIN A SW-NE ORIENTED BAND ACRS NE PA AND PTNS OF THE WRN
CATSKILLS. THIS FEATURE IS ON THE NWRN/DEFORMATION SIDE OF A S/WV
LIFTING THROUGH THE RGN THIS MRNG. POP/WX/SNOWFALL GRIDS WERE
UPDATED TO REFLECT SUCH DVLPMTS. WE`VE ADDED A CORRIDOR OF 2-3"
ADDNL SNOWFALL WITHIN THE AFOREMENTIONED BAND AREA THROUGH
15-16Z. A SHORT-TERM SPS WAS ALSO ISSUED.
OTHWS...THE FCST IS PRETTY WELL IN HAND. FAIRLY DEEP LYR OF INSTAB
NOTED ON THE 12Z KBUF SNDG...INDICATIVE OF THE AMS WE`LL HAVE
THROUGH EARLY AFTN...AHD OF THE NEXT INCOMING S/WV. LIKELY POPS
FOR SNOW SHWRS OVER MOST OF CNY...WITH MORE SCTD ACTIVITY ACRS
MUCH OF NE PA...STILL SEEMS REASONABLE...WITH A FLUFFY 1-2"
ANTICIPATED IN THE MOST PERSISTENT SHSN. IT`S WORTH NOTING THAT
THE LATEST HRRR AND HI-RES ARW OUTPUT IN PARTICULAR SHOW A WELL
FORMED MULTI-BAND/FINGER LKS BAND FROM LTR THIS MRNG...THROUGH THE
AFTN...AND INTO THE EVE HRS...DOWN THE AXIS OF CAYUGA LAKE...AND THEN
SEWD FROM THERE THROUGH AT LEAST TOMPKINS/TIOGA CNTYS. SINCE THERE
ARE ALREADY SOME INDICATIONS OF BANDING IN THIS GENERAL AREA
ATTM...WE`LL MONITOR THAT CLOSELY THROUGH THE DAY.
GIVEN STG CAA THROUGHOUT THE COLUMN...SHARPLY FALLING TEMPS STILL
LOOK LIKELY...AND OUR PREVIOUSLY ADVERTISED TREND WAS KEPT IN TACT.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY/...
2 PM FRI UPDATE... OVERALL...THINGS LOOK FAIRLY QUIET SAT-SUN
MRNG. WINDS SHOULD RELAX SAT...SO THE WIND CHILL EXPIRATION TIME
OF 16Z STILL LOOKS GOOD ATTM. A WEAK SFC FRNT AND NRN STREAM S/WV
ARE PROGGED TO TRAVERSE THE FA SAT NGT INTO THE FIRST PART OF
SUN...WITH ONLY SCTD LGT SNOW SHWRS AND FLRYS ANTICIPATED...AND
LTL IN THE WAY OF ACCUM.
RECENT GLOBAL MODEL TRENDS (GFS/EC/GEM) HAVE PERSISTED WITH THE
12Z FRI CYCLE...INDICATING A MORE AMPLIFIED UPR-LVL WV...FARTHER N
SFC LOW TRACK...AND RESULTANT INCREASED SNOWFALL POTENTIAL FOR
CNY/NE PA. MUCH MORE ON THIS SYSTEM IN THE FOLLOWING SXN. FOR
NOW...WE`VE BROUGHT THE LEADING EDGE OF STEADIER SNOW (CHC-LIKELY
POPS) INTO AT LEAST SWRN/SRN PTNS OF THE FA BY MID TO LATE AFTN ON SUN.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
CONFIDENCE IS GROWING THAT THE AREA WILL BE AFFECTED BY A MOISTURE LADEN STORM
SYSTEM AS IT MOVES FROM THE OHIO VALLEY OFF THE EAST COAST SUNDAY
NIGHT INTO MONDAY. EXPECT SNOW TO CONTINUE OVERSPREADING THE
REGION SUNDAY EVENING AND POTENTIALLY BECOME HEAVY AT TIMES
OVERNIGHT INTO EARLY MONDAY. AS THIS EVENT IS STILL MORE THAN 48
HOURS OUT, THERE IS STILL A LOT OF UNCERTAINTY IN THE DETAILS OF
THE SYSTEM AND IT`S EXACT TRACK BUT AS DISCUSSED ABOVE FORECAST
GUIDANCE HAS COME INTO BETTER AGREEMENT WITH THIS UPDATE CYCLE.
THE TRACK OF THE LOW SOUTH OF THE CWA SHOULD RESULT IN THE HEAVIER
AMOUNTS (POTENTIALLY 6+ INCHES) GENERALLY OCCURRING ACROSS NE PA
NORTHWARD ACROSS THE SOUTHERN TIER OF UPSTATE NEW YORK THEN EAST
INTO THE CATSKILLS WITH LIGHTER AMOUNTS FARTHER NORTH. WORTH
NOTING, HOWEVER, IS THAT IF THE LOW TRACK WERE TO TREND EVEN
FARTHER NORTH THIS COULD INTRODUCE MIXED PRECIP INTO NE PA CUTTING
AMOUNTS DOWN THERE AND RESULTING IN MORE WIDESPREAD HIGHER TOTALS
OVER NY. SO, AS MENTIONED, STILL UNCERTAINTY SO WE WILL HOLD OFF
ON WATCH AT THIS TIME. FINALLY, THE ARCTIC AIR IN PLACE AHEAD OF
THIS SYSTEM WILL ALSO RESULT IN THIS BEING A VERY COLD EVENT WITH
TEMPS GENERALLY IN THE TEENS AND EVEN SINGLE DIGITS IN THE FAR NORTH WHICH
WILL BE ACCOMPANIED BY INCREASING WINDS LATER MONDAY.
EXPECT SNOW TO WIND DOWN BY LATER MONDAY WITH SOME LAKE EFFECT
POSSIBLE IN IT`S WAKE MONDAY NIGHT. ALSO EXPECT VERY COLD TEMPS BY
LATER MONDAY NIGHT AS ARCTIC HIGH BUILDS IN WITH WIDESPREAD
SUBZERO READINGS. TUESDAY WILL BE GENERALLY FAIR BUT COLD WITH
BRIEF MODERATION TO SEASONAL WEDNESDAY BEFORE ANOTHER ARCTIC FRONT MOVES
THROUGH LATE WEDNESDAY WITH SNOW SHOWERS AND COLDER TEMPS TO
FOLLOW FOR THE END OF THE WEEK. NW FLOW ALSO WILL BRING THE
POTENTIAL FOR SOME LAKE EFFECT INTO THURSDAY.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
00Z UPDATE...
LAKE EFFECT CONTINUES ACRS TERMINALS THIS EVENING BRINGING
IFR/MVFR RESTRICTIONS TO MOST TERMINALS. NW FLOW WILL BRING OCNL
IFR RESTRICTIONS TO ITH THRU 06Z AND POSSIBLY SYR THRU 03Z AND BGM
THRU 06Z. AVP AND RME ON THE FRINGE OF LAKE EFFECT WILL SEE VFR
THRU MOST OF THE PERIOD WITH EXCEPTION OF RME POSSIBLY DROPPING TO
MVFR LATE IN TAF VALID TIME.
ITH AND BGM WILL LIKELY SEE IFR RESTRICTIONS AFTER 06Z WITH MVFR
CONTINUING THROUGH END OF TAF VALID TIME. ELM AND SYR EXPECTED TO
SEE VFR IN BETWEEN DIMINISHING LAKE EFFECT AND NEXT SYSTEM MOVING
IN, MAINLY DURING THE MORNING INTO EARLY AFTERNOON HOURS. LATER IN
TAF VALID TIME THE POTENTIAL EXIST FOR MVFR CIGS TO WORK IN TO
TERMINALS.
NORTHWEST WINDS WILL PERSIST AROUND 10KTS THROUGH END OF TAF VALID
TIME THOUGH OCCASIONALLY GUSTING TO ARND 20KTS EARLY AT SOUTHERN
TERMINALS (ITH, ELM, BGM AND AVP).
OUTLOOK...
SAT NGT AND MOST OF SUN...VFR.
SUN NGT / MON... RESTRICTIONS LIKELY (MVFR/IFR) IN SNOW.
TUE...VFR.
WED...POSSIBLE RESTRICTIONS DUE TO SNOW SHOWERS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WIND CHILL ADVISORY UNTIL 11 AM EST SATURDAY FOR PAZ038>040-
043-044-047-048-072.
LAKE EFFECT SNOW ADVISORY UNTIL 1 AM EST SATURDAY FOR PAZ039.
NY...WIND CHILL ADVISORY UNTIL 11 AM EST SATURDAY FOR NYZ009-
015>018-022>025-036-037-044>046-055>057-062.
LAKE EFFECT SNOW ADVISORY UNTIL 1 AM EST SATURDAY FOR NYZ025-
055-056.
&&
$$
SYNOPSIS...MLJ
NEAR TERM...HEDEN/MLJ
SHORT TERM...MLJ
LONG TERM...PCF
AVIATION...PVF
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
645 PM EST FRI JAN 30 2015
.SYNOPSIS...
VERY COLD AIR WILL CONTINUE TO POUR INTO THE REGION TONIGHT...WITH
LAKE-EFFECT SNOW PERSISTING DOWNWIND FROM THE FINGER LAKES...AND
BITTERLY COLD WIND CHILLS AREA-WIDE. COLD TEMPERATURES WILL LAST
THROUGH THE UPCOMING WEEKEND...WITH ONLY A FEW FLURRIES FORESEEN
FROM SATURDAY INTO EARLY SUNDAY. AN APPROACHING WINTER STORM COULD
BEGIN TO IMPACT THE AREA BY LATE SUNDAY AFTERNOON OR SUNDAY
EVENING...WITH ACCUMULATING SNOW POSSIBLE.
&&
.NEAR TERM /THROUGH SATURDAY/...
145 PM UPDATE... ONLY MINOR TWEAKS MADE TO THE GRIDS THIS PD.
AREA-WIDE WIND CHILL ADVSY STILL LOOKS ON TRACK FOR THE OVERNIGHT
HRS...AS VERY STG 925-850 MB CAA THROUGH THIS EVE...SHOULD SEND
AIR TEMPS INTO THE SINGLE DIGITS ABV OR BLO ZERO TNT...WITH THE
PRES GRADIENT REMAINING RELATIVELY TIGHT THIS EVE...AND ONLY
SLOWLY RELAXING LATE. MOST AREAS SHOULD SEE APPARENT TEMPS IN THE
-10 TO -20 RANGE...WITH LOCALLY COLDER VALUES IN OUR FAR NRN AND
ERN ZNS.
AS FAR AS THE LES ADVSY GOES...NO CHGS ATTM. ALTHOUGH BLYR INSTAB
(TERRESTRIAL CAPE VALUES OF 15-30 J/KG) TEMPORARILY RESULTED IN A
MORE CELLULAR APPEARANCE TO THE SNOW SHWRS EARLIER THIS AFTN
LOW-LVL STABILIZATION AND INCRG SHEAR SHOULD RESULT IN THE RE-
EMERGENCE OF WELL DEFINED BANDS BY 21Z OR SO. IN FACT...EVIDENCE
OF SUCH IS ALREADY SEEN ON KBGM RADAR IMAGERY ATTM. MOST HI-RES
MODEL GUIDANCE HINTS THAT MULTI-BANDS/FINGER LKS BANDS WILL REMAIN
AT PLAY TIL AT LEAST 06-12Z SAT. OVERALL...INTENSITY SHOULD WANE
AFTER 06Z...AS MODEL SNDGS SHOW THE CAPPING INVERSION LWRG TO AOB
875-900 MB. WE`LL STICK WITH OUR 3-6" TOTALS FOR NOW...ALTHOUGH
WUDN`T BE SURPRISED TO SEE LOCALLY HIER AMTS...SPCLY IN SERN
TOMPKINS AND/OR NRN TIOGA.
OUTSIDE OF MULTI-BAND AREAS...EITHER WIDELY SCTD -SHSN/FLRYS...OR
JUST DRY WX...IS FORESEEN.
PREV DISC... 10 AM UPDATE... WE`VE ISSUED A LES ADVSY FOR
TOMPKINS...TIOGA...BROOME...AND SUSQ CNTYS...AS CONFIDENCE HAS
BECOME FAIRLY HIGH IN THE MAINTENANCE OF A WELL DVLPD FINGER LKS
BAND...THROUGH AT LEAST 00-03Z THIS EVE. OUR FIRST STAB AT SNOW
TOTALS IS 3-6"...BUT LOCALLY HIER AMTS ARE CERTAINLY PSBL.
NO OTHER SIG CHGS ATTM.
EARLIER DISC... 830 AM UPDATE... SN/+SN IS BEING OBSERVED ATTM
WITHIN A SW-NE ORIENTED BAND ACRS NE PA AND PTNS OF THE WRN
CATSKILLS. THIS FEATURE IS ON THE NWRN/DEFORMATION SIDE OF A S/WV
LIFTING THROUGH THE RGN THIS MRNG. POP/WX/SNOWFALL GRIDS WERE
UPDATED TO REFLECT SUCH DVLPMTS. WE`VE ADDED A CORRIDOR OF 2-3"
ADDNL SNOWFALL WITHIN THE AFOREMENTIONED BAND AREA THROUGH
15-16Z. A SHORT-TERM SPS WAS ALSO ISSUED.
OTHWS...THE FCST IS PRETTY WELL IN HAND. FAIRLY DEEP LYR OF INSTAB
NOTED ON THE 12Z KBUF SNDG...INDICATIVE OF THE AMS WE`LL HAVE
THROUGH EARLY AFTN...AHD OF THE NEXT INCOMING S/WV. LIKELY POPS
FOR SNOW SHWRS OVER MOST OF CNY...WITH MORE SCTD ACTIVITY ACRS
MUCH OF NE PA...STILL SEEMS REASONABLE...WITH A FLUFFY 1-2"
ANTICIPATED IN THE MOST PERSISTENT SHSN. IT`S WORTH NOTING THAT
THE LATEST HRRR AND HI-RES ARW OUTPUT IN PARTICULAR SHOW A WELL
FORMED MULTI-BAND/FINGER LKS BAND FROM LTR THIS MRNG...THROUGH THE
AFTN...AND INTO THE EVE HRS...DOWN THE AXIS OF CAYUGA LAKE...AND THEN
SEWD FROM THERE THROUGH AT LEAST TOMPKINS/TIOGA CNTYS. SINCE THERE
ARE ALREADY SOME INDICATIONS OF BANDING IN THIS GENERAL AREA
ATTM...WE`LL MONITOR THAT CLOSELY THROUGH THE DAY.
GIVEN STG CAA THROUGHOUT THE COLUMN...SHARPLY FALLING TEMPS STILL
LOOK LIKELY...AND OUR PREVIOUSLY ADVERTISED TREND WAS KEPT IN TACT.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY/...
2 PM FRI UPDATE... OVERALL...THINGS LOOK FAIRLY QUIET SAT-SUN
MRNG. WINDS SHOULD RELAX SAT...SO THE WIND CHILL EXPIRATION TIME
OF 16Z STILL LOOKS GOOD ATTM. A WEAK SFC FRNT AND NRN STREAM S/WV
ARE PROGGED TO TRAVERSE THE FA SAT NGT INTO THE FIRST PART OF
SUN...WITH ONLY SCTD LGT SNOW SHWRS AND FLRYS ANTICIPATED...AND
LTL IN THE WAY OF ACCUM.
RECENT GLOBAL MODEL TRENDS (GFS/EC/GEM) HAVE PERSISTED WITH THE
12Z FRI CYCLE...INDICATING A MORE AMPLIFIED UPR-LVL WV...FARTHER N
SFC LOW TRACK...AND RESULTANT INCREASED SNOWFALL POTENTIAL FOR
CNY/NE PA. MUCH MORE ON THIS SYSTEM IN THE FOLLOWING SXN. FOR
NOW...WE`VE BROUGHT THE LEADING EDGE OF STEADIER SNOW (CHC-LIKELY
POPS) INTO AT LEAST SWRN/SRN PTNS OF THE FA BY MID TO LATE AFTN ON SUN.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
CONFIDENCE IS GROWING THAT THE AREA WILL BE AFFECTED BY A MOISTURE LADEN STORM
SYSTEM AS IT MOVES FROM THE OHIO VALLEY OFF THE EAST COAST SUNDAY
NIGHT INTO MONDAY. EXPECT SNOW TO CONTINUE OVERSPREADING THE
REGION SUNDAY EVENING AND POTENTIALLY BECOME HEAVY AT TIMES
OVERNIGHT INTO EARLY MONDAY. AS THIS EVENT IS STILL MORE THAN 48
HOURS OUT, THERE IS STILL A LOT OF UNCERTAINTY IN THE DETAILS OF
THE SYSTEM AND IT`S EXACT TRACK BUT AS DISCUSSED ABOVE FORECAST
GUIDANCE HAS COME INTO BETTER AGREEMENT WITH THIS UPDATE CYCLE.
THE TRACK OF THE LOW SOUTH OF THE CWA SHOULD RESULT IN THE HEAVIER
AMOUNTS (POTENTIALLY 6+ INCHES) GENERALLY OCCURRING ACROSS NE PA
NORTHWARD ACROSS THE SOUTHERN TIER OF UPSTATE NEW YORK THEN EAST
INTO THE CATSKILLS WITH LIGHTER AMOUNTS FARTHER NORTH. WORTH
NOTING, HOWEVER, IS THAT IF THE LOW TRACK WERE TO TREND EVEN
FARTHER NORTH THIS COULD INTRODUCE MIXED PRECIP INTO NE PA CUTTING
AMOUNTS DOWN THERE AND RESULTING IN MORE WIDESPREAD HIGHER TOTALS
OVER NY. SO, AS MENTIONED, STILL UNCERTAINTY SO WE WILL HOLD OFF
ON WATCH AT THIS TIME. FINALLY, THE ARCTIC AIR IN PLACE AHEAD OF
THIS SYSTEM WILL ALSO RESULT IN THIS BEING A VERY COLD EVENT WITH
TEMPS GENERALLY IN THE TEENS AND EVEN SINGLE DIGITS IN THE FAR NORTH WHICH
WILL BE ACCOMPANIED BY INCREASING WINDS LATER MONDAY.
EXPECT SNOW TO WIND DOWN BY LATER MONDAY WITH SOME LAKE EFFECT
POSSIBLE IN IT`S WAKE MONDAY NIGHT. ALSO EXPECT VERY COLD TEMPS BY
LATER MONDAY NIGHT AS ARCTIC HIGH BUILDS IN WITH WIDESPREAD
SUBZERO READINGS. TUESDAY WILL BE GENERALLY FAIR BUT COLD WITH
BRIEF MODERATION TO SEASONAL WEDNESDAY BEFORE ANOTHER ARCTIC FRONT MOVES
THROUGH LATE WEDNESDAY WITH SNOW SHOWERS AND COLDER TEMPS TO
FOLLOW FOR THE END OF THE WEEK. NW FLOW ALSO WILL BRING THE
POTENTIAL FOR SOME LAKE EFFECT INTO THURSDAY.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
00Z UPDATE...
LAKE EFFECT CONTINUES ACRS TERMINALS THIS EVENING BRINGING
IFR/MVFR RESTRICTIONS TO MOST TERMINALS. NW FLOW WILL BRING OCNL
IFR RESTRICTIONS TO ITH THRU 06Z AND POSSIBLY SYR THRU 03Z AND BGM
THRU 06Z. AVP AND RME ON THE FRINGE OF LAKE EFFECT WILL SEE VFR
THRU MOST OF THE PERIOD WITH EXCEPTION OF RME POSSIBLY DROPPING TO
MVFR LATE IN TAF VALID TIME.
ITH AND BGM WILL LIKELY SEE IFR RESTRICTIONS AFTER 06Z WITH MVFR
CONTINUING THROUGH END OF TAF VALID TIME. ELM AND SYR EXPECTED TO
SEE VFR IN BETWEEN DIMINISHING LAKE EFFECT AND NEXT SYSTEM MOVING
IN, MAINLY DURING THE MORNING INTO EARLY AFTERNOON HOURS. LATER IN
TAF VALID TIME THE POTENTIAL EXIST FOR MVFR CIGS TO WORK IN TO
TERMINALS.
NORTHWEST WINDS WILL PERSIST AROUND 10KTS THROUGH END OF TAF VALID
TIME THOUGH OCCASIONALLY GUSTING TO ARND 20KTS EARLY AT SOUTHERN
TERMINALS (ITH, ELM, BGM AND AVP).
OUTLOOK...
SAT NGT AND MOST OF SUN...VFR.
SUN NGT / MON... RESTRICTIONS LIKELY (MVFR/IFR) IN SNOW.
TUE...VFR.
WED...POSSIBLE RESTRICTIONS DUE TO SNOW SHOWERS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WIND CHILL ADVISORY UNTIL 11 AM EST SATURDAY FOR PAZ038>040-
043-044-047-048-072.
LAKE EFFECT SNOW ADVISORY UNTIL 1 AM EST SATURDAY FOR PAZ039.
NY...WIND CHILL ADVISORY UNTIL 11 AM EST SATURDAY FOR NYZ009-
015>018-022>025-036-037-044>046-055>057-062.
LAKE EFFECT SNOW ADVISORY UNTIL 1 AM EST SATURDAY FOR NYZ025-
055-056.
&&
$$
SYNOPSIS...MLJ
NEAR TERM...MLJ
SHORT TERM...MLJ
LONG TERM...PCF
AVIATION...PVF
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
340 PM EST THU JAN 29 2015
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL SPREAD
ACCUMULATING SNOW ACROSS OUR REGION TONIGHT INTO FRIDAY.
TEMPERATURES WILL PLUMMET FRIDAY...WITH GUSTY WINDS SENDING WIND
CHILLS WELL BELOW ZERO FRIDAY NIGHT. COLD AIR WILL REMAIN INTO
NEXT WEEK.
&&
.NEAR TERM /THROUGH FRIDAY/...
SURFACE LOW IS MOVING INTO SOUTHERN ONTARIO WITH PRECIP SPREADING
EAST ACROSS NY. AT THIS POINT A LITTLE LIGHT SNOW IN THE CWA HAS
BEEN CONFINED MAINLY TO THE NORTHERN ZONES AS THERE IS A LOT OF
LOW LEVEL DRY AIR IN PLACE FARTHER SOUTH. HOWEVER MAIN BATCH OF
PRECIP NOW AROUND BUFFALO WILL MOVE EAST WITH LIGHT SNOW MOVING
INTO REMAINING AREAS OF THE CWA TOWARD THE LATE AFTERNOON / EARLY
EVENING TIME FRAME AS LOW LEVELS SATURATE.
EXPECT LIGHT SNOW TO CONTINUE THROUGH MOST OF THE NIGHT AS THE LOW MOVES
EAST WITH THE HEAVIEST AMOUNTS OVER NORTHERN PARTS OF THE CWA FROM
ONONDAGA EAST THROUGH ONEIDA COUNTIES...AS DYNAMICS WILL BE
STRONGEST HERE...AND THERE WILL ALSO BE ADDED OROGRAPHIC LIFT IN
THE TUG HILL PLATEAU REGION. NAM AND RAP SEEM TO BE HANDLING THIS
FAIRLY WELL SO LEANED FORECAST TOWARD THESE MODELS. THE LOW WILL
DRAG A COLD FRONT THROUGH LATE TONIGHT SHIFTING THE WINDS TO THE
NW AND STARTING THE LAKE EFFECT MACHINE. ARCTIC AIR RETURNS
QUICKLY FRIDAY UNDER AN UPPER LEVEL TROF WITH FALLING TEMPS
THROUGH THE DAY. MODERATE SW WINDS WILL SHIFT TO STRONGER NW WINDS
LATE TONIGHT AND CREATE DRIFTING AND BLOWING SNOW.
WITH A NW LL FLOW FRIDAY LAKE EFFECT FRIDAY WILL BE ACROSS THE USUAL
AREAS OF CENTRAL NY. CAA WILL INCREASE LAPSE RATES ESPECIALLY IN
THE AFTN. AT THE SAME TIME THE INVERSION AND DENDRITE ZONE LOWER.
MULTI BAND LES COULD BE BRIEFLY HEAVY.
A WINTER WEATHER ADVISORY REMAINS IN EFFECT FOR THE NRN THIRD OF THE CWA
FOR THE SYNOPTIC SNOW OF 2 TO 5 INCHES TONIGHT FOLLOWED BY
ANOTHER 1 TO 4 INCHES OF LES FRIDAY. IN ADDITION WIND GUSTS TO 35
WILL CAUSE BLOWING AND DRIFTING SNOW FRIDAY. FURTHER SOUTH, WE GENERALLY
EXPECT SNOW AMOUNTS THROUGH FRIDAY OF 1 TO 3 INCHES FROM NE PA
THROUGH THE SOUTHERN TIER OF NY.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
315 PM UPDATE... LINGERING MULTI-BAND LES ACRS CNY AND PA`S NRN
TIER FRI EVE...WILL SLOWLY DIMINISH OVERNIGHT...AS THE CAPPING
INVERSION LWRS. ANOTHER LOCALIZED 1-2" MAY ACCUMULATE FRI NGT OVER
THE HIGHER TERRAIN OF THE UPR SUSQ/FINGER LKS RGNS IN CNY.
VERY COLD WIND CHILL READINGS ARE DEFINITELY A CONCERN FRI
NGT...WITH SFC WINDS ONLY SLOWLY SUBSIDING...AND ACTUAL AIR TEMPS
DROPPING INTO THE 5 ABV TO 10 BLO RANGE. WE`LL CONTINUE TO
HIGHLIGHT THIS SITN IN THE HWO...CITING THE POTENTIAL FOR WC
ADVSYS OR WRNGS IN LATER FCST UPDATES.
OTHER THAN PERHAPS A FEW FLRYS ON SAT...THE DAY SHOULD BE LARGELY
DRY...WITH BRIEF RIDGING AT THE SFC AND SOME S/WV RIDGING ALOFT
ACRS THE FA.
SAT NGT INTO SUN MRNG...A WEAK NRN STREAM S/WV AND SFC FRNT WILL
PUSH SWD THROUGH CNY/NE PA...ACCOMPANIED BY FLRYS AND SCTD LGT
SNOW SHWRS (LTL OR NO ACCUMS).
BY LATER SUN AFTN...WE MAY SEE SOME STEADIER LGT SNOW APPROACH OUR
FAR SWRN ZNS...ON THE OUTER EDGES OF THE NEXT S/WV AND FAST MOVG
SFC WV. MORE ON THIS SYSTEM IN THE FOLLOWING SXN.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
330 PM UPDATE... MODEL DISAGREEMENT/INCONSISTENCY CONTS WITH THE
LATEST CYCLES REGARDING THE SUN NGT-MON STORM SYSTEM. THE MOST RECENT
RUNS OF THE EC/GFS HAVE TRENDED NWD SOMEWHAT AGN...NOW TRACKING
THE SFC LOW THROUGH VA AND SERN MD...AND BRINGING LGT SNOW AT
LEAST TO THE PA/NY BORDER...IF NOT INTO NY`S SRN TIER.
MEANWHILE...THE CAN GEM HAS NOW GONE MUCH FARTHER S...TAKING THE
SFC WV THROUGH THE CAROLINAS...WITH LTL OR NO SNOWFALL FOR OUR FA.
GIVEN ALL THE UNCERTAINTY...THE EXPECTATION OF FURTHER MODEL
WAFFLING...AND ALSO THE FACT THAT THE SUPPORTING S/WV ENERGY IS
NOW JUST APPROACHING THE PACIFIC COAST OF NORTH AMERICA...WE`LL
SIMPLY MAKE VERY SMALL INCREMENTAL CHGS ATTM...JUST EASING POPS
UPWARD AGN TO INCORPORATE THE LATEST EC/GFS TRENDS. THIS RESULTS
IN LIKELY POPS FOR OUR FAR SRN ZNS SUN NGT (BACK DOWN TO CHC BY
MON)...AND CHC POPS THROUGHOUT THIS PD FOR OUR NY SRN TIER CNTYS.
ALTHOUGH...STRICTLY SPEAKING...WE`RE CURRENTLY INDICATING THE
POTENTIAL FOR A FEW INCHES OF SNOW OVER PTNS OF NE PA...THIS WILL
CERTAINLY BE SUBJECT TO CHANGE OVER THE NEXT COUPLE OF DAYS. STAY
TUNED FOR THE LATEST UPDATES ON THIS SITN.
TUE INTO WED LOOK QUIETER...BUT VERY COLD...WITH ONLY SOME FLRYS
FORESEEN AT WORST.
BY WED NGT AND THU...OUR NEXT REINFORCING COLD FRNT AND NRN STREAM
S/WV APPROACH...BRINGING A CHC OF SNOW SHWRS. THE EC IS ALSO
SHOWING THE PSBLTY THAT SOME SRN STREAM MOISTURE GETS INCORPORATED
INTO THE SYSTEM. STILL PLENTY OF TIME TO SORT ALL OF THESE FINE
DETAILS OUT.
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
UPDATED AT 1245 PM...VFR CONDITIONS WILL PREVAIL THRU THIS
AFTERNOON WITH INCREASING HIGH CLOUDS. A LOW PRESSURE SYSTEM WILL
MOVE ACROSS THE AREA LATE TODAY AND TONIGHT BRINGING PERIODS OF
LIGHT SNOW WITH OCCASIONAL IFR VSBYS AND CIGS AFTER 22Z. SURFACE
WINDS WILL GENERALLY BE SOUTH-SOUTHEAST 5 TO 15 KTS THIS
AFTERNOON INTO THIS EVENING. ALSO, A STRONG LOW LEVEL JET WILL
RESULT IN WIND SHEAR BECOMING AN ISSUE THIS AFTERNOON AND
PERSISTING INTO THIS EVENING AS WINDS NEAR 2000 FT WILL BE
INCREASING TO 40+ KNOTS.
FOR FRIDAY, EXPECT STRONG NW WINDS GUSTING 20 TO 30 KNOTS AND SNOW
SHOWERS ON THE BACKSIDE OF TODAY`S SYSTEM. CONDITIONS FRIDAY WILL GENERALLY
BE MVFR WITH OCCASIONAL IFR CEILINGS AND VISBYS POSSIBLE IN
HEAVIER SNOW SHOWERS...ESPECIALLY AROUND KSYR.
OUTLOOK...
FRI NGT...PSBL RESTRICTIONS (MVFR/IFR) IN SNOW SHWRS...SPCLY IN
THE EVE OVER NORTHERN AREAS
SAT...SAT NGT...AND MOST OF SUN...VFR.
SUN NGT MON...PSBL RESTRICTIONS (MVFR/IFR) IN SNOW.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...WINTER WEATHER ADVISORY UNTIL 5 PM EST FRIDAY FOR NYZ009-
016>018-036-037-044>046.
&&
$$
SYNOPSIS...PCF
NEAR TERM...PCF
SHORT TERM...MLJ
LONG TERM...MLJ
AVIATION...PCF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
ISSUED BY NATIONAL WEATHER SERVICE BLACKSBURG VA
1213 PM EST THU JAN 29 2015
.SYNOPSIS...
HIGH PRESSURE WILL MOVE OFFSHORE THIS AFTERNOON AHEAD OF A COLD
FRONT THAT WILL CROSS THE AREA TONIGHT INTO FRIDAY MORNING. HIGH
PRESSURE WILL BUILD IN FROM THE WEST ON FRIDAY...WHICH WILL HELP
TO KEEP CONDITIONS DRY INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1027 AM THURSDAY...
15Z ANALYSIS SHOWS HIGH PRESSURE CONTINUING TO PUSH EAST OF US WHILE
THE COLD FRONT OVER THE OHIO VALLEY MOVES EAST. CLOUDS WILL
CONTINUE TO INCREASE ACROSS OUR AREA AS THIS PATTERN EVOLVES AND THE
COLD FRONT APPROACHES. MODELS STILL SUGGESTING A FEW RAIN SPRINKLES
OR LIGHT RAIN SHOWERS ARE POSSIBLE LATER TODAY IN ADVANCE OF THE
FRONT...WITH THE BEST CHANCES ACROSS OUR NORTHERN AND WESTERN ZONES.
LATEST HRRR SUGGESTS THE SLIGHT CHANCE POPS THIS AFTERNOON MAY NEED
TO BE EXPANDED A LITTER FURTHER EASTWARD ACROSS OUR AREA...BUT
EITHER WAY...ANY RAIN THAT OCCURS WILL BE VERY LIGHT WITH LOW
IMPACTS. OTHERWISE...NO SIGNIFICANT CHANGES WITH THE MORNING
UPDATE.
PREV DISCUSSION AS OF 230 AM...OPTIMAL RADIATIONAL COOLING FOR THE
NEXT COUPLE OF HOURS WHILE HIGH PRESSURE OVERHEAD CALMS WINDS AND
SKIES REMAIN CLEAR. THIS WONT LAST FOR TOO LONG HOWEVER AS HIGH
CLOUDS ARE BEGINNING TO MOVE IN FROM THE WEST ASSOCIATED WITH A
FRONTAL SYSTEM WITH PARENT MOVING INTO THE CHICAGO AREA AT THIS
TIME. THE ATTENDANT COLD FRONT...WHICH IS WEAK IS PROGGED TO CROSS
CENTRAL NC LATER TONIGHT AND INTO FRIDAY MORNING. UNTIL
THEN...SOUTHERLY RETURN FLOW WILL PICK UP ON THE BACK SIDE OF THE
SURFACE HIGH AFTER SUNRISE WITH SOME GUSTING AROUND 15 KTS
POSSIBLE...ESPECIALLY IN THE WEST WHICH IS FURTHER AWAY FROM THE
CENTER OF THE HIGH. USING DRY ADIABATIC METHODS OR LOW LEVEL
THICKNESSES SUGGEST TEMPERATURES IN THE MID TO UPPER 50S BUT WITH
THE INCREASING CLOUD COVER...ESPECIALLY DURING PEAK HEATING THESE
NUMBERS WILL BE CUT BACK TO THE UPPER 40S TO MID 50S. CANT RULE OUT
SOME HIGHER TEMPS IN THE SOUTHEAST...WHERE THE EFFECTS OF THE
APPROACHING SYSTEM WILL BE MOST DELAYED.
AS FAR AS PRECIPITATION CHANCES ARE CONCERNED WITH THE ACTUAL
FRONT...CONDITIONS ARE DRY BUT THE LATEST VERSION OF THE MODELS IS
NOT QUITE AS DRY AS YESTERDAY WITH PW VALUES INCREASING TO NEAR 0.7
INCHES AS OPPOSED TO 0.5 YESTERDAY. A FIRST LOOK AT HIGH RESOLUTION
CONVECTIVE MODELS ALSO SHOWS SOME VERY LIGHT PRECIPITATION IN THE
NORTHWEST PIEDMONT JUST AFTER 21Z AND FADING OUT AS IT HEADS
EASTWARD BEFORE PICKING UP AGAIN OFF THE COAST. FORECAST SOUNDINGS
SHOW A SIMILAR STORY WITH THE BEST SATURATION IN THE TRIAD WITH LESS
LIKELY CHANCES FOR RAIN SOUTH AND EAST. DESPITE BETTER CHANCES IN
THE TRIAD...SATURATION IN THE MODEL SOUNDINGS IS BRIEF AND CONFINED
TO THE 850-700 MB RANGE WITH A LOT OF DRY AIR
UNDERNEATH...SUGGESTIVE OF SPRINKLES OR VIRGA PERHAPS IF MOISTURE
CANT REACH THE SURFACE. THE RESULT IS STILL VERY INCONSEQUENTIAL AS
QPF AMOUNTS WOULD BE A COUPLE OF HUNDREDTHS OF AN INCH AT THE VERY
BEST BUT MORE LIKELY TRACE AMOUNTS OR NOTHING. BETTER UPPER LEVEL
DYNAMICS COME IN AFTER 00Z FRIDAY BUT THE SYSTEM JUST LOOKS TO DRY
TO SUSTAIN ANYTHING AT THAT TIME.
AFTER FRONTAL PASSAGE AROUND 6Z FRIDAY...WINDS WILL SHIFT BACK TO
NORTHWESTERLY AND COLD AIR ADVECTION WILL ONCE AGAIN ENSUE.
LINGERING CLOUD COVER BEHIND THE FRONT WILL KEEP LOWS WARMER...IN
THE LOW TO UPPER 30S NW TO SE. AS DRY AIR WORKS IN BEHIND THE
FRONT...CLOUDS MAY CLEAR OUT FOR THE LATE MORNING PERIOD...BUT THEN
WRAP AROUND MOISTURE ON THE BACK SIDE OF THE EXITING SYSTEM WILL
MOVE IN FROM THE NORTH AND CUT DOWN ON INSOLATION DURING PEAK
HEATING. THIS MAY CAUSE A TEMPERATURE GRADIENT FROM THE NORTH TO
SOUTH RESULTING IN HIGHS IN THE MID 40S TO LOW 50S. DRY CONDITIONS
ARE EXPECTED AND INCREASING WINDS OF 15-20 KTS SUSTAINED WITH GUSTS
OF UP TO 25 KTS COULD CAUSE SOME FIRE WEATHER CONCERNS ON FRIDAY
AFTERNOON. AT THIS TIME MIN RH VALUES WILL HOVER AROUND 30%. WINDS
WILL DIE OFF AFTER SUNSET AND COUPLED WITH CLEAR SKIES WILL CAUSE
OPTIMAL RADIATIONAL COOLING RESULTING IN LOW TEMPERATURES NEAR 20
DEGREES FRIDAY NIGHT INTO SATURDAY MORNING.
&&
.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM THURSDAY...
SURFACE HIGH PRESSURE OVER THE TN VALLEY WILL BUILD SOUTHWARD ACROSS
THE AREA ON SATURDAY...SHIFTING SOUTH AND OFF THE SOUTHEAST COAST
SATURDAY NIGHT. ALOFT...WEAK SOUTHERN STREAM IMPULSES EMBEDDED IN
INCREASING ZONAL FLOW ALOFT LATE SATURDAY/SATURDAY NIGHT WILL YIELD
THICKENING CIRRUS LAYER THROUGH THE DAY WITH MOSTLY CLOUDY SKIES BY
SATURDAY NIGHT. HIGHS WILL REMAIN BELOW NORMAL...RANGING FROM LOWER
40S NORTH TO MID/UPPER 40S SOUTH. LOWS SATURDAY NIGHT IN THE LOWER
TO MID 30S.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 300 AM THURSDAY...
SUNDAY THROUGH MONDAY: MINOR MID-LEVEL IMPULSES EMANATING FROM THE
UPPER TROUGH/CLOSED LOW OVER THE SOUTHWEST US...WILL
INTERACT....POTENTIALLY PHASE WITH NORTHERN STREAM ENERGY DIVING
SEWD WITHIN THE BROADENING CONUS TROUGH. ASSOCIATED CYCLOGENESIS
WILL TRACK EASTWARD ACROSS THE LOWER MS VALLEY/MID-SOUTH ON
SUNDAY...CROSSING THE SOUTHERN APPALACHIANS SUNDAY EVENING AND THEN
OFF THE CAROLINA COAST BY MIDDAY MONDAY. DESPITE MODEL
DIFFERENCES IN THE AMPLITUDE OF THE NORTHERN STREAM
TROUGH...TIMING OF THE BETTER RAIN CHANCES INTO THE AREA ARE
SIMILAR...WITH RAIN CHANCES QUICKLY RAMPING UP LATE SUNDAY
AFTERNOON/EARLY EVENING...WITH CATEGORICAL POPS SUNDAY
NIGHT...CUTTING OFF FROM WEST TO EAST MORNING MONDAY AS THE MID-
LEVEL DRY SLOT SPREAD EAST. CURRENT MODELS PROJECT A SOLID
0.50-1.0" ACROSS THE AREA...WITH SOME HIGHER AMOUNTS POSSIBLE IF
THE MORE AMPLIFIED--WETTER GFS VERIFIES. NO P- TYPE CONCERNS.
HIGHS BOTH DAYS IN THE 40S NORTH TO AROUND 50 SOUTH. LOWS SUNDAY
NIGHT IN THE MID TO UPPER 30S NORTH TO LOWER-MID 40S SOUTH.
MONDAY NIGHT THROUGH WEDNESDAY: CONTINENTAL POLAR HIGH PRESSURE WILL
BUILD INTO THE AREA MONDAY NIGHT AND INTO TUESDAY IN THE WAKE OF THE
UPPER LEVEL TROUGH LIFTING OUT OF THE AREA. IF PROJECTED LOW-LEVEL
THICKNESSES VERIFY...STRONG CAA MONDAY NIGHT WILL SUPPORT LOWS
TUESDAY MORNING IN THE TEENS ACROSS MUCH OF THE AREA...WITH HIGHS
TUESDAY AFTERNOON STRUGGLING TO WARM INTO THE 40S.
MODEL SPREAD REMAINS HIGH WITH THE EASTWARD EJECTION OF THE
AFOREMENTIONED UPPER TROUGH/LOW OVER THE SOUTHWEST US. WHILE THE EC
SUGGEST THIS SYSTEM COULD BRING PRECIP CHANCES BACK INTO THE AREA
LATE TUESDAY NIGHT AND INTO WEDNESDAY...THE GFS AND CANADIAN
SUPPRESS THE SYSTEM WELL TO OUR SOUTH...MAINTAINING DRY CONDITIONS
THROUGH LATE WEEK. GIVEN THE UNCERTAINTY HAVE LIMITED POP TO
SLIGHT/SMALL CHANCE.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 1202 PM EST THURSDAY...
24 HOUR TAF PERIOD: BANDS OF HIGH AND MID CLOUDS WILL CONTINUE TO
SWEEP EAST THIS AFTERNOON AHEAD OF AN APPROACHING COLD FRONT JUST
WEST OF THE MOUNTAINS. CEILINGS MAY LOWER BELOW 8K FEET ACROSS
THE WESTERN SITES LATE THIS AFTERNOON AS A DEEPER BAND OF MOISTURE
SWINGS EAST AND WEAKENS. THUS WILL CONTINUE MEDIUM TO HIGH
CONFIDENCE OF VFR CONDITIONS THROUGH THE TAF PERIOD AS THIS FRONT
SLIDES ACROSS THE FROM THE WEST TONIGHT. THERE IS A SLIGHT CHANCE
THAT CEILINGS COULD APPROACH MVFR LEVELS BETWEEN 03Z-08Z/10PM-3AM
BUT IFFY AND MAINLY WEST OF KRDU AT THIS POINT. SOUTH TO SOUTHWEST
WINDS MAY ALSO GUST TO BETWEEN 15-20 KTS THIS AFTERNOON BEFORE
RELAXING AGAIN AFTER SUNSET. MAYBE A SPRINKLE OR LIGHT SHOWER IN
THE TRIAD AHEAD OF THE FRONT DURING THE LATE AFTERNOON/EARLY
EVENING TIMEFRAME.
THE PASSING COLD FRONT WILL BRING A SHIFT IN WINDS TO THE
WEST/NORTHWEST AFTER MIDNIGHT FOLLOWED BY GUSTY NORTHWEST WINDS
FOR MUCH OF THE DAY ON FRIDAY. APPEARS SUSTAINED NORTHWEST WINDS
OF 15-22 KNOTS LIKELY WITH GUSTS TO 25-30 KNOTS OR PERHAPS HIGHER
NEAR THE END OF THE VALID TAF PERIOD.
LONG TERM: SUB-VFR CONDITIONS WILL BE POSSIBLE WITH A LOW PRESSURE
SYSTEM THAT WILL CROSS THE AREA LATE SUNDAY INTO MONDAY. VFR
CONDITIONS WILL PREVAIL ON TUESDAY AS HIGH PRESSURE BUILDS EAST
BEHIND THIS SYSTEM.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JH/ELLIS
NEAR TERM...-/ELLIS
SHORT TERM...CBL
LONG TERM...CBL
AVIATION...JH/ELLIS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1027 AM EST THU JAN 29 2015
.SYNOPSIS...HIGH PRESSURE WILL MOVE OFFSHORE TODAY AND GIVE WAY
TO A COLD FRONT THAT WILL CROSS THE AREA TONIGHT INTO FRIDAY
MORNING. HIGH PRESSURE WILL BUILD IN FROM THE WEST ON FRIDAY...WHICH
WILL HELP TO KEEP CONDITIONS DRY THROUGH MUCH OF THE WEEKEND.
&&
.NEAR TERM /THROUGH FRIDAY NIGHT/...
AS OF 1027 AM THURSDAY...
15Z ANALYSIS SHOWS HIGH PRESSURE CONTINUING TO PUSH EAST OF US WHILE
THE COLD FRONT OVER THE OHIO VALLEY MOVES EAST. CLOUDS WILL
CONTINUE TO INCREASE ACROSS OUR AREA AS THIS PATTERN EVOLVES AND THE
COLD FRONT APPROACHES. MODELS STILL SUGGESTING A FEW RAIN SPRINKLES
OR LIGHT RAIN SHOWERS ARE POSSIBLE LATER TODAY IN ADVANCE OF THE
FRONT...WITH THE BEST CHANCES ACROSS OUR NORTHERN AND WESTERN ZONES.
LATEST HRRR SUGGESTS THE SLIGHT CHANCE POPS THIS AFTERNOON MAY NEED
TO BE EXPANDED A LITTER FURTHER EASTWARD ACROSS OUR AREA...BUT
EITHER WAY...ANY RAIN THAT OCCURS WILL BE VERY LIGHT WITH LOW
IMPACTS. OTHERWISE...NO SIGNIF CHANGES WITH THE MORNING UPDATE.
PREV DISCUSSION AS OF 230 AM...OPTIMAL RADIATIONAL COOLING FOR THE
NEXT COUPLE OF HOURS WHILE HIGH PRESSURE OVERHEAD CALMS WINDS AND
SKIES REMAIN CLEAR. THIS WONT LAST FOR TOO LONG HOWEVER AS HIGH
CLOUDS ARE BEGINNING TO MOVE IN FROM THE WEST ASSOCIATED WITH A
FRONTAL SYSTEM WITH PARENT MOVING INTO THE CHICAGO AREA AT THIS
TIME. THE ATTENDANT COLD FRONT...WHICH IS WEAK IS PROGGED TO CROSS
CENTRAL NC LATER TONIGHT AND INTO FRIDAY MORNING. UNTIL
THEN...SOUTHERLY RETURN FLOW WILL PICK UP ON THE BACK SIDE OF THE
SURFACE HIGH AFTER SUNRISE WITH SOME GUSTING AROUND 15 KTS
POSSIBLE...ESPECIALLY IN THE WEST WHICH IS FURTHER AWAY FROM THE
CENTER OF THE HIGH. USING DRY ADIABATIC METHODS OR LOW LEVEL
THICKNESSES SUGGEST TEMPERATURES IN THE MID TO UPPER 50S BUT WITH
THE INCREASING CLOUD COVER...ESPECIALLY DURING PEAK HEATING THESE
NUMBERS WILL BE CUT BACK TO THE UPPER 40S TO MID 50S. CANT RULE OUT
SOME HIGHER TEMPS IN THE SOUTHEAST...WHERE THE EFFECTS OF THE
APPROACHING SYSTEM WILL BE MOST DELAYED.
AS FAR AS PRECIPITATION CHANCES ARE CONCERNED WITH THE ACTUAL
FRONT...CONDITIONS ARE DRY BUT THE LATEST VERSION OF THE MODELS IS
NOT QUITE AS DRY AS YESTERDAY WITH PW VALUES INCREASING TO NEAR 0.7
INCHES AS OPPOSED TO 0.5 YESTERDAY. A FIRST LOOK AT HIGH RESOLUTION
CONVECTIVE MODELS ALSO SHOWS SOME VERY LIGHT PRECIPITATION IN THE
NORTHWEST PIEDMONT JUST AFTER 21Z AND FADING OUT AS IT HEADS
EASTWARD BEFORE PICKING UP AGAIN OFF THE COAST. FORECAST SOUNDINGS
SHOW A SIMILAR STORY WITH THE BEST SATURATION IN THE TRIAD WITH LESS
LIKELY CHANCES FOR RAIN SOUTH AND EAST. DESPITE BETTER CHANCES IN
THE TRIAD...SATURATION IN THE MODEL SOUNDINGS IS BRIEF AND CONFINED
TO THE 850-700 MB RANGE WITH A LOT OF DRY AIR
UNDERNEATH...SUGGESTIVE OF SPRINKLES OR VIRGA PERHAPS IF MOISTURE
CANT REACH THE SURFACE. THE RESULT IS STILL VERY INCONSEQUENTIAL AS
QPF AMOUNTS WOULD BE A COUPLE OF HUNDREDTHS OF AN INCH AT THE VERY
BEST BUT MORE LIKELY TRACE AMOUNTS OR NOTHING. BETTER UPPER LEVEL
DYNAMICS COME IN AFTER 00Z FRIDAY BUT THE SYSTEM JUST LOOKS TO DRY
TO SUSTAIN ANYTHING AT THAT TIME.
AFTER FRONTAL PASSAGE AROUND 6Z FRIDAY...WINDS WILL SHIFT BACK TO
NORTHWESTERLY AND COLD AIR ADVECTION WILL ONCE AGAIN ENSUE.
LINGERING CLOUD COVER BEHIND THE FRONT WILL KEEP LOWS WARMER...IN
THE LOW TO UPPER 30S NW TO SE. AS DRY AIR WORKS IN BEHIND THE
FRONT...CLOUDS MAY CLEAR OUT FOR THE LATE MORNING PERIOD...BUT THEN
WRAP AROUND MOISTURE ON THE BACK SIDE OF THE EXITING SYSTEM WILL
MOVE IN FROM THE NORTH AND CUT DOWN ON INSOLATION DURING PEAK
HEATING. THIS MAY CAUSE A TEMPERATURE GRADIENT FROM THE NORTH TO
SOUTH RESULTING IN HIGHS IN THE MID 40S TO LOW 50S. DRY CONDITIONS
ARE EXPECTED AND INCREASING WINDS OF 15-20 KTS SUSTAINED WITH GUSTS
OF UP TO 25 KTS COULD CAUSE SOME FIRE WEATHER CONCERNS ON FRIDAY
AFTERNOON. AT THIS TIME MIN RH VALUES WILL HOVER AROUND 30%. WINDS
WILL DIE OFF AFTER SUNSET AND COUPLED WITH CLEAR SKIES WILL CAUSE
OPTIMAL RADIATIONAL COOLING RESULTING IN LOW TEMPERATURES NEAR 20
DEGREES FRIDAY NIGHT INTO SATURDAY MORNING.
&&
.SHORT TERM /SATURDAY AND SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...
SURFACE HIGH PRESSURE OVER THE TN VALLEY WILL BUILD SOUTHWARD ACROSS
THE AREA ON SATURDAY...SHIFTING SOUTH AND OFF THE SOUTHEAST COAST
SATURDAY NIGHT. ALOFT...WEAK SOUTHERN STREAM IMPULSES EMBEDDED IN
INCREASING ZONAL FLOW ALOFT LATE SATURDAY/SATURDAY NIGHT WILL YIELD
THICKENING CIRRUS LAYER THROUGH THE DAY WITH MOSTLY CLOUDY SKIES BY
SATURDAY NIGHT. HIGHS WILL REMAIN BELOW NORMAL...RANGING FROM LOWER
40S NORTH TO MID/UPPER 40S SOUTH. LOWS SATURDAY NIGHT IN THE LOWER
TO MID 30S.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 300 AM THURSDAY...
SUNDAY THROUGH MONDAY: MINOR MID-LEVEL IMPULSES EMANATING FROM THE
UPPER TROUGH/CLOSED LOW OVER THE SOUTHWEST US...WILL
INTERACT....POTENTIALLY PHASE WITH NORTHERN STREAM ENERGY DIVING
SEWD WITHIN THE BROADENING CONUS TROUGH. ASSOCIATED CYCLOGENESIS
WILL TRACK EASTWARD ACROSS THE LOWER MS VALLEY/MID-SOUTH ON
SUNDAY...CROSSING THE SOUTHERN APPALACHIANS SUNDAY EVENING AND THEN
OFF THE CAROLINA COAST BY MIDDAY MONDAY. DESPIT MODEL DIFFERENCES
IN THE AMPLITUDE OF THE NORTHERN STREAM TROUGH...TIMING OF THE
BETTER RAIN CHANCES INTO THE AREA ARE SIMILAR...WITH RAIN CHANCES
QUICKLY RAMPING UP LATE SUNDAY AFTERNOON/EARLY EVENING...WITH
CATEGORICAL POPS SUNDAY NIGHT...CUTTING OFF FROM WEST TO EAST
MORNING MONDAY AS THE MID-LEVEL DRY SLOT SPREAD EAST. CURRENT
MODELS PROJECT A SOLID 0.50-1.0" ACROSS THE AREA...WITH SOME HIGHER
AMOUNTS POSSIBLE IF THE MORE AMPLIFIED--WETTER GFS VERIFIES. NO P-
TYPE CONCERNS. HIGHS BOTH DAYS IN THE 40S NORTH TO AROUND 50 SOUTH.
LOWS SUNDAY NIGHT IN THE MID TO UPPER 30S NORTH TO LOWER-MID 40S
SOUTH.
MONDAY NIGHT THROUGH WEDNESDAY: CONTINENTAL POLAR HIGH PRESSURE WILL
BUILD INTO THE AREA MONDAY NIGHT AND INTO TUESDAY IN THE WAKE OF THE
UPPER LEVEL TROUGH LIFTING OUT OF THE AREA. IF PROJECTED LOW-LEVEL
THICKNESSES VERIFY...STRONG CAA MONDAY NIGHT WILL SUPPORT LOWS
TUESDAY MORNING IN THE TEENS ACROSS MUCH OF THE AREA...WITH HIGHS
TUESDAY AFTERNOON STRUGGLING TO WARM INTO THE 40S.
MODEL SPREAD REMAINS HIGH WITH THE EASTWARD EJECTION OF THE
AFOREMENTIONED UPPER TROUGH/LOW OVER THE SOUTHWEST US. WHILE THE EC
SUGGEST THIS SYSTEM COULD BRING PRECIP CHANCES BACK INTO THE AREA
LATE TUESDAY NIGHT AND INTO WEDNESDAY...THE GFS AND CANADIAN
SUPPRESS THE SYSTEM WELL TO OUR SOUTH...MAINTAINING DRY CONDITIONS
THROUGH LATE WEEK. GIVEN THE UNCERTAINTY HAVE LIMITED POP TO
SLIGHT/SMALL CHANCE.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AS OF 645 AM THURSDAY...
24 HOUR TAF PERIOD: MEDIUM HIGH CONFIDENCE OF VFR CONDITIONS THROUGH
THE TAF PERIOD AS A DRY FRONTAL SYSTEM CROSSES THE AREA NEAR THE END
OF THE PERIOD. BANDS OF HIGH CLOUDS HAVE STARTED TO CROSS THE AREA
FROM THE WEST. LATER TODAY CLOUD COVER WILL INCREASE AS BROKEN
CEILINGS SET IN BY 18Z OR SO BUT THESE SHOULD BE IN THE 8-9 KFT
RANGE. THERE IS A SLIGHT CHANCE THAT CEILING COULD APPROACH MVFR
LEVELS AROUND 3Z BUT CONFIDENCE IN THIS IS LOW. AS FAR AS WINDS ARE
CONCERNED...EXPECT SOUTHERLY WINDS AT 5-10 KTS AFTER
DAYBREAK...GUSTING 15-20 KTS BEFORE RELAXING AGAIN AFTER SUNSET.
MAYBE A SPRINKLE OR LIGHT SHOWER IN THE TRIAD AHEAD OF THE FRONT
DURING THE 21-00Z TIMEFRAME.
LONG TERM: SUB-VFR CONDITIONS WILL BE POSSIBLE WITH A LOW PRESSURE
SYSTEM THAT WILL CROSS THE AREA LATE SUNDAY INTO MONDAY. VFR
CONDITIONS WILL PREVAIL FOR MUCH OF THE WEEK AFTER THAT.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...ELLIS
NEAR TERM... -/ELLIS
SHORT TERM...CBL
LONG TERM...CBL
AVIATION...ELLIS
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
944 PM EST FRI JAN 30 2015
.SYNOPSIS...
ARCTIC AIR WILL BRING BITTER COLD TEMPERATURES AND SUBZERO WIND
CHILLS TO MUCH OF CENTRAL PENNSYLVANIA TONIGHT INTO EARLY SATURDAY.
CONFIDENCE IS INCREASING FOR A HIGH IMPACT WINTER WEATHER EVENT
SUNDAY INTO MONDAY WITH THE POTENTIAL FOR SIGNIFICANT SNOW
ACCUMULATION AND SOME MIXED WINTRY PRECIPITATION. ANOTHER SHOT
OF VERY COLD ARCTIC AIR SHOULD FOLLOW FOR TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
THE COLD FRONT HAS CLEARED THE EASTERN ZONES AND ARCTIC AIR IS
BEGINNING TO FILTER INTO THE REGION. THE RAP SHOWS THE CORE OF LOW
LEVEL COLD AIR ENTERING WESTERN PA SO TEMPS WHICH ARE STILL
RELATIVELY MILD OVER ABOUT THE EASTERN 1/2 OR SO OF MY FCST
AREA...WILL LEVEL OFF AND EVEN BEGIN FALLING SOON.
THE REMAINDER OF TODAY WILL BE BLUSTERY AND TURNING COLDER. MOST
OF THE LINGERING SNOW SHOWERS WILL FAVOR THE USUAL WESTERN AND
NORTHERN HIGHER TERRAIN...WITH CENTRAL AND EASTERN AREAS SEEING
JUST A SMALL CHANCE OF A BRIEF SNOW SHOWER OR PASSING FLURRY.
WIND CHILLS WILL RANGE FROM 5 TO 15 BELOW ZERO OVER WESTERN
HIGHER ELEVATIONS BY LATE IN THE DAY IN THE GUSTY WINDS BEHIND
THE DEPARTING FRONT.
SKIES WILL CLEAR ACROSS MOST OF THE REGION OVERNIGHT. WESTERN
UPSLOPE AREAS AND MY FAR NORTHEASTERN ZONES MAY KEEP CLOUDS AND
LINGERING FLURRIES THE LONGEST...BUT FORECAST SOUNDINGS SHOW THE
INVERSION HEIGHTS COMING DOWN SO THE CHANCES FOR ACTUAL
MEASURABLE SNOW WILL BE DWINDLING QUICKLY. WINDS REMAINING IN THE
10-15 MPH RANGE...WITH HIGHER GUSTS WILL KEEP WIND CHILLS IN THE
10-20 BELOW ZERO RANGE OVER MUCH OF THE REGION.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
SATURDAY WILL START BRIGHT IN MOST AREAS AS THE HIGH CRESTS JUST
TO OUR SOUTH. HIGH CLOUDS MAY BEGIN TO INVADE FOR THE LAST HALF OF
THE AFTERNOON...BUT THEY SHOULD DO LITTLE TO MAR AN OTHERWISE FAIR
ALBEIT COLD MID WINTER`S DAY.
HIGHS FROM THE MID TEENS TO MID 20S NORTH TO SOUTH WILL BE ABOUT
15 DEG BELOW NORMAL ON AVERAGE.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
*SIGNIFICANT WINTER WEATHER/SNOW EVENT POSSIBLE SUNDAY-MONDAY
*BITTER COLD TEMPERATURES AND DANGEROUS WIND CHILLS POSSIBLE
MONDAY NIGHT INTO TUESDAY
A POTENTIALLY WIDESPREAD HIGH IMPACT WINTER WX EVENT APPEARS TO
BE SHAPING UP ACROSS CENTRAL PENNSYLVANIA FOR SUNDAY INTO MONDAY.
A WINTER STORM WATCH HAS BEEN ISSUED FOR ALL CENTRAL PA COUNTIES
AND IS VALID FROM 12PM SUNDAY THROUGH 12 PM MONDAY. CONFIDENCE IN
THE EVENT OCCURRING IS AVERAGE WITH SLIGHTLY LOWER CONFIDENCE IN
THE DETAILS SUCH AS LOCATION AND SNOW ACCUM NUMBERS GIVEN THE
UNCERTAINTY IN THE TRACK OF THE SYSTEM...AND POTENTIAL FOR MIXED
PCPN/WARMER TEMPS IN THE SRN 1/3 OF THE AREA.
A SHORTWAVE NOW ENTERING CENTRAL BRITISH COLUMBIA WILL BE DIGGING
SOUTHEAST DOWN INTO THE NORTHERN/CENTRAL PLAINS LATER SAT AND INTO
SUN. THIS ENERGY COUPLED WITH A MORE SUBTLE SHORTWAVE ON ITS HEELS
DROPPING DOWN FROM THE NORTHWEST TERRITORIES WILL PLAY A KEY ROLE
IN THE EVOLUTION OF SURFACE LOW PRESSURE THAT IS CURRENTLY
FORECAST TO DEVELOP OVER THE LOWER MO AND MID MS VALLEY REGION BY
EARLY SUN BEFORE THEN AIMING EAST TOWARD THE OH VALLEY AND MID-
ATLANTIC STATES SUN NIGHT AND MON. AS THIS STORM DEVELOPS...MUCH
COLDER AIR WILL BUILD NOT ONLY BEHIND THE SYSTEM AS A LARGE ARCTIC
ANTICYCLONE HEADS SOUTHWARD INTO THE NORTHERN PLAINS...BUT COLDER
AIR WILL ALSO BLEED EASTWARD AS PRESSURES RISE OVER SOUTHEASTERN
CANADA AND NORTHERN NEW ENGLAND IN ASSOCIATION WITH A PRONOUNCED
UPPER CONFLUENCE ZONE. THE COMBINATION OF THESE TWO SYSTEMS WILL
HELP GENERATE A INCREASINGLY TIGHT BAROCLINIC ZONE UPON WHICH THE
DEVELOPING SURFACE LOW WILL MOVE ALONG.
THE PREVAILING SHIFT IN THE 12Z MODELS WAS TO CONTINUE A MORE
NORTHERLY TRACK WITH THIS SYSTEM...WHICH IS REFLECTED IN THE WPC
FORECAST WHICH WAS WEIGHTED HEAVILY IN THE FINAL GRIDDED SNOW/ICE
ACCUMULATIONS. HOWEVER FORECAST CONFIDENCE IS TEMPERED BY THE RUN-
TO- RUN INCONSISTENCIES THE MODELS HAVE SHOWN ALONG THE WITH
DISTINCT POSSIBILITY THAT THE MODELS MAY REVERSE TRENDS IN
SUBSEQUENT RUNS. WITH SEVERAL FORECAST CYCLES COMING UP ANTICIPATE
SOME CHANGES REGARDING NUMBERS AND LOCATIONS OF SNOWFALL TOTALS.
A SHOT OF ARCTIC AIR IS FORECAST TO SURGE INTO THE AREA BEHIND THE
EARLY WEEK STORM WITH POTENTIAL FOR DANGEROUS WIND CHILLS MONDAY
NIGHT INTO TUESDAY. THIS COULD ADD TO STORM-RELATED IMPACTS. HIGH
PRESSURE SHOULD BRING COLD BUT QUIET WEATHER INTO MIDWEEK. MODELS
AND ENSEMBLES SHOW A COASTAL TYPE SYSTEM SOMETIME NEXT WED-FRI BUT
IT IS WAY TOO EARLY TO SPECULATE ON THIS SYSTEM.
&&
.AVIATION /01Z SATURDAY THROUGH WEDNESDAY/...
IFR AT KJST WILL CONTINUE INTO THE EARLY MORNING HOURS AS SNOW
SHOWERS AND LOW CIGS PERSIST IN THE NWRLY UPSLOPE FLOW. UPSLOPE
WINDS ALSO CONTINUE TO SUPPORT MVFR CIGS AT KBFD AND KAOO. VFR
HAS RETURNED ELSEWHERE AND SHOULD PREVAIL INTO TOMORROW...THOUGH A
STRAY REMAINING SNOW SHOWER COULD BRING SOME TEMP REDUCTIONS
OVERNIGHT.
GUSTY WINDS WILL CONTINUE INTO THE OVERNIGHT BUT DIMINISHING
SOMEWHAT TO BETWEEN 15-20KT.
OUTLOOK...
SAT...VFR.
SUN...WIDESPREAD IFR/MVFR DEVELOPING ASSOCIATED WITH A STORM
MOVING TOWARD THE REGION.
MON...REDUCED CONDS EARLY...IMPROVING AS THE STORM MOVES AWAY FROM
THE AREA.
TUE-WED...NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
MORNING FOR PAZ004>006-010>012-017>019-024>028-033>037-041-042-
045-046-049>053-056>059-063>066.
WIND CHILL ADVISORY UNTIL 11 AM EST SATURDAY FOR PAZ004>006-
010>012-017>019-024-033-037-041-042-045-046-049-051>053-058.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...STEINBUGL
AVIATION...LA CORTE/GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
532 PM EST THU JAN 29 2015
.SYNOPSIS...
AN ALBERTA CLIPPER/ARCTIC COLD FRONT WILL CROSS THE AREA TONIGHT.
HIGH PRESSURE WILL RETURN FOR LATE FRIDAY INTO SATURDAY. A NEW
STORM IS EXPECTED TO PASS WELL SOUTH OF THE AREA LATER SUNDAY
INTO MONDAY...FOLLOWED BY ANOTHER SURGE OF COLD AIR FOR EARLY
NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
POTENT LOOKING SHORTWAVE IN WATER VAPOR LOOP WORKING INTO WESTERN
PA THIS EVENING. WAA ALONG AXIS OF SOUTHERLY LL JET PRODUCING SNOW
ACROSS MUCH OF CENTRAL PA AS OF 22Z. HOWEVER...WARMER AIR ALOFT
HAS WORKED INTO THE LAUREL HIGHLANDS...TURNING PRECIP TO FZRA FROM
S CLEARFIELD COUNTY SOUTHWARD.
FOR MOST OF CENTRAL PA...EXPECT OCNL LGT SNOW TO CONTINUE THRU
LATE EVENING...AS UPPER LVL SHORTWAVE ROLLS THRU. OVR THE S TIER
COUNTIES...LATEST HRRR AND 4KM NAM SOUNDINGS CONTINUE TO INDICATE
ENOUGH WARMING ALOFT FOR SOME LGT FREEZING RAIN OVERNIGHT.
NEAR TERM MDL DATA TIMES THE BACK EDGE OF THE DEEP MOISTURE/SIG
PRECIP INTO THE LAUREL HIGHLANDS ARND 03Z AND THE EASTERN
COUNTIES BY ARND 06Z.
HAVE DECIDED TO COVER THE THREAT FOR ICY CONDITIONS WITH A
WINT WEATHER ADVISORY OVER MY SOUTHERN TIER. OVERALL REASONING
HAS NOT CHANGED WITH JUST ENOUGH WARM AIR ALOFT EXPECTED TO CAUSE
A PERIOD OF NUISANCE-TYPE ICING.
HAVE TWEAKED SNOWFALL TOTALS IN OUR GRIDDED FORECASTS...BASED ON
SFC REPORTS AND LATEST GUIDANCE. LOOKS LIKE ARND 4 INCHES ACROSS
THE NW MTNS...TO LESS THAN AN INCH FROM HARRISBURG SOUTHWARD. HAVE
INCLUDED LIGHT ICE TOTALS OF A TENTH OF AN INCH OR LESS ACROSS
SOUTHERN PA.
THE COLD FRONT SHOULD BE SWINGING THROUGH THE ALLEGHENY MTNS ARND
03Z AND THE EASTERN ZONES SHORTLY AFTER 06Z. BEHIND THE FRONT...ONLY
SCT LAKE EFFECT SNOW SHOWERS SHOULD REMAIN EARLY FRIDAY MORNING
OVR THE ALLEGHENY MTNS.
LOW TEMPS TONIGHT WILL RANGE FROM THE MID TO UPPER TEENS ACROSS
THE WRN MTNS...TO THE MID AND UPPER 20S ACROSS THE SUSQ VALLEY. IF
THE FRONT IS FASTER THAN EXPECTED...THESE COULD BE A TAD TOO HIGH.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
FRIDAY WILL BE A BLUSTERY AND COLD DAY AS ARCTIC AIR PAYS A
RETURN VISIT. LINGERING SNOW SHOWERS WILL FAVOR THE USUAL WESTERN
AND NORTHERN HIGHER TERRAIN WITH CENTRAL AND EASTERN AREAS
PROBABLY SEEING LITTLE MORE THAN SOME STRAY FLURRIES.
TEMPS WILL LIKELY PEAK EARLY AND EITHER STAY STEADY OR FALL
THROUGHOUT THE DAY. WIND CHILLS WILL RANGE FROM 5 TO 15 BELOW ZERO
OVER WESTERN HIGHER ELEVATIONS BY LATE IN THE DAY AS WINDS BECOME
GUSTY BEHIND THE DEPARTING FRONT.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
TOOK OUT MENTION OF SNOW FRIDAY NIGHT...FLOW TOO NORTHERLY.
WIND CHILL ADVISORIES WILL LIKELY BE NEEDED ACROSS NORTH
CENTRAL PA FRIDAY NIGHT INTO SATURDAY MORNING UNTIL AROUND
14Z. STILL MAINLY 3RD PERIOD...WILL HOLD OFF AN ADVISORY
FOR NOW.
SATURDAY LOOKS SUNNY BUT ON THE COLD SIDE.
SOME CHC OF SOME LIGHT SNOW SATURDAY NIGHT AND EARLY SUNDAY
ACROSS THE FAR NORTH...WITH COLD FRONT DROPPING SE. HAVE
LOW CHC IN EARLY SUNDAY ACROSS THE FAR WEST.
MODELS STILL SHOW POTENTIAL FOR A LOW MOVING JUST SOUTH
OF PA LATER SUNDAY INTO EARLY MONDAY. THUS LEFT SNOW IN
THE FCST. DID SOME MAKE A FEW ADJUSTMENTS. MAIN THING WAS
TO CUT BACK POPS ACROSS THE NW EARLY MONDAY. NOT SEEING
A LOT OF POTENTIAL FOR LAKE EFFECT LATE MONDAY...FLOW TOO
NORTHERLY. THUS MADE A FEW ADJUSTMENTS MONDAY NIGHT.
ANOTHER SHOT OF COLD AIR IN FOR MONDAY NIGHT INTO TUE...AS
HIGH PRESSURE BUILDS IN FROM THE PLAINS.
MODELS HINT AT ANOTHER LOW TRACKING NEAR THE AREA ON WED.
HAVE LOW END POPS FOR SNOW. MORE COLD AIR BEHIND THAT SYSTEM.
&&
.AVIATION /22Z THURSDAY THROUGH TUESDAY/...
VFR CONDITIONS WILL RAPIDLY DETERIORATE AS SNOW OVERSPREADS THE
REGION FROM WEST TO EAST.
SNOW WILL BEGIN SHORTLY IN BRADFORD. EXPECT IFR CONDITIONS TO
DEVELOP RAPIDLY WITH THE SNOW...SPREADING EAST 18-00Z. SOUTHERN
TIER TERMINALS FROM JST-AOO EAST INTO THE LOWER SUSQ VALLEY COULD
SEE A PERIOD OF LIGHT FREEZING RAIN OR SLEET AS THE PRECIPITATION
DEVELOPS.
REDUCED CONDITIONS SHOULD IMPROVE OVERNIGHT WITH THE PASSAGE OF
THE COLD FRONT...AROUND 03Z FRIDAY OVER THE WEST. MORE LIKE
06-09Z OVER THE SERN AREAS. THE CONDITIONS AT BFD AND JST WILL
LIKELY REMAIN MVFR/IFR WITH SNOW SHOWERS INTO FRIDAY.
OUTLOOK...
SAT...VFR.
SUN...LOWER CONDITIONS POSSIBLE OVER SOUTHERN AREAS ASSOCIATED
WITH A STORM MOVING THROUGH THE CAROLINAS.
MON...REDUCED CONDS EARLY IN SNOW SHOWERS. IMPROVING FROM WEST TO
EAST AFTERNOON ONWARD.
TUE...NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 AM EST FRIDAY FOR PAZ004>006-
010-011-017-024-033.
WINTER WEATHER ADVISORY UNTIL 1 AM EST FRIDAY FOR PAZ025>028-
034>036-056-057-059-063>066.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...FITZGERALD/LA CORTE
SHORT TERM...LA CORTE
LONG TERM...MARTIN
AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
126 PM EST THU JAN 29 2015
.SYNOPSIS...
AN ALBERTA CLIPPER/ARCTIC COLD FRONT WILL CROSS THE AREA TONIGHT.
HIGH PRESSURE WILL RETURN FOR LATE FRIDAY INTO SATURDAY. A NEW
STORM IS EXPECTED TO PASS WELL SOUTH OF THE AREA LATER SUNDAY
INTO MONDAY...FOLLOWED BY ANOTHER SURGE OF COLD AIR FOR EARLY
NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
HAVE DECIDED TO COVER THE THREAT FOR ICY CONDITIONS INTO THE
EVENING HOURS WITH A WEATHER ADVISORY OVER MY SOUTHERN TIER.
OVERALL REASONING HAS NOT CHANGED WITH JUST ENOUGH WARM AIR ALOFT
EXPECTED TO CAUSE A PERIOD OF NUISANCE-TYPE ICING.
THE MAIN AREA OF PRECIP IS ON TRACK AND SHOWN BY THE HRRR TO BE
ENTERING MY WESTERN ZONES BY 18-19Z. STILL SOME CONCERN FOR A
BRIEF PERIOD OF LIGHT FREEZING RAIN OR SLEET SO WE PUT AN
ADVISORY OVER THE SOUTHERN COUNTIES TO COVER THE POTENTIAL FOR
SOME LIGHT ICING. GUIDANCE IS CONSISTENT IN SHOWING WARM AIR
SURGING IN ALOFT TODAY...THEN BEING PINCHED OFF QUICKLY AS PRECIP
DEVELOPS AND THE COLUMN EVAPORATIVELY COOLS. HOWEVER...THE
RAP/HRRR HOURLY DATA SHOW THE WARM AIR ACTUALLY PUSHING BACK NORTH
BETWEEN 21-00Z OVER THE SWRN ZONES...COMPLICATING THE PRECIP TYPE
SCENARIO FROM THE LAURELS EASTWARD ALONG THE MARYLAND BORDER
COUNTIES.
A STRONG SHOT OF WAA ALOFT AND MODERATELY STG UPPER LEVEL
DIVERGENCE ASSOCIATED WITH THE RIGHT ENTRANCE REGION OF AN UPPER
LVL JET MAX ACROSS SRN ONTARIO WILL LEAD TO PERIODS OF SNOW
THIS AFTERNOON INTO TONIGHT. ALREADY 4-STAR SNOW AT MEADVILLE
WITH MODERATE SNOW OVER NERN OHIO UP INTO ERIE.
SNOWFALL TOTALS IN OUR GRIDDED FORECASTS LOOK REASONABLE AND WE
HAVE INCLUDED LIGHT ICE TOTALS OF A TENTH OF AN INCH OR LESS.
THE COLD FRONT WILL BE ENTERING WESTERN PA JUST AFTER DARK...AND
SHOULD BE SWINGING THROUGH MY EASTERN ZONES BETWEEN MIDNIGHT AND
6 AM. SNOW WILL TAPER TO SNOW SHOWERS AND FLURRIES BY LATE
TONIGHT...MAINLY IN THE ISOLATED FORM ACROSS THE CENTRAL AND
SOUTHERN VALLEYS.
LOW TEMPS TONIGHT WILL RANGE FROM THE MID TO UPPER TEENS ACROSS
THE WRN MTNS...TO THE MID AND UPPER 20S ACROSS THE SUSQ VALLEY. IF
THE FRONT IS FASTER THAN EXPECTED...THESE COULD BE A TAD TOO HIGH.
&&
.SHORT TERM /FRIDAY/...
FRIDAY WILL BE A BLUSTERY AND COLD DAY AS ARCTIC AIR PAYS A
RETURN VISIT. LINGERING SNOW SHOWERS WILL FAVOR THE USUAL WESTERN
AND NORTHERN HIGHER TERRAIN WITH CENTRAL AND EASTERN AREAS
PROBABLY SEEING LITTLE MORE THAN SOME STRAY FLURRIES.
TEMPS WILL LIKELY PEAK EARLY AND EITHER STAY STEADY OR FALL
THROUGHOUT THE DAY. WIND CHILLS WILL RANGE FROM 5 TO 15 BELOW ZERO
OVER WESTERN HIGHER ELEVATIONS BY LATE IN THE DAY AS WINDS BECOME
GUSTY BEHIND THE DEPARTING FRONT.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
PERIODS OF GENERALLY LIGHTER SNOW WILL LINGER INTO EARLY
FRIDAY...AS THE MAIN COLD FRONT DROPS SE.
A TIGHT LLVL PRESSURE GRADIENT IN THE WAKE OF THE COLD FRONT WILL
BRING GUSTY NORTHWEST WINDS AND SLOWLY FALLING TEMPS ACROSS THE
REGION DURING THE DAYLIGHT HOURS FRIDAY. WIND GUSTS WILL BE IN
THE MID TO UPPER 20 KT RANGE FOR MOST AREAS CREATING A WIND CHILL
IN THE SINGLE DIGITS TO LOW TEENS IN THE SUSQ VALLEY....AND 5
BELOW TO 15 BELOW ACROSS THE NRN AND WRN MTNS.
FRIDAY NIGHT WILL BE BITTERLY COLD...AS SKIES CLEAR AND WINDS DIE
DOWN. LOW TEMPS WILL VARY FROM THE SINGLE DIGITS BELOW ZERO ACROSS
THE NORTH...TO SINGLE DIGITS ABOVE ZERO IN THE SOUTH.
A BRIGHT DAY ON SAT...BUT NOT REAL WARM.
STILL HAVE CHC POPS ON SUNDAY. A LOT OF SPREAD IN THE MODEL OUTPUT
THE LAST FEW DAYS. 12Z MODELS BACKING OFF SOME NOW. PATTERN
SUPPORTS LOW PRESSURE SYSTEMS THAT ARE FAST MOVING AND WEAK. WOULD
STILL EXPECT SOME LIGHT SNOW INTO MONDAY MORNING.
A COLD NIGHT MONDAY NIGHT...AS THE NEXT HIGH BUILDS INTO
THE AREA.
SOME HINTS AT ANOTHER FAST MOVING LOW FOR MID WEEK...FOR NOW
WENT WITH CHC POPS.
MINOR CHANGES TO THE PACKAGE MADE.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
VFR CONDITIONS WILL RAPIDLY DETERIORATE AS SNOW OVERSPREADS THE
REGION FROM WEST TO EAST.
SNOW WILL BEGIN SHORTLY IN BRADFORD. EXPECT IFR CONDITIONS TO
DEVELOP RAPIDLY WITH THE SNOW...SPREADING EAST 18-00Z. SOUTHERN
TIER TERMINALS FROM JST-AOO EAST INTO THE LOWER SUSQ VALLEY COULD
SEE A PERIOD OF LIGHT FREEZING RAIN OR SLEET AS THE PRECIPITATION
DEVELOPS.
REDUCED CONDITIONS SHOULD IMPROVE OVERNIGHT WITH THE PASSAGE OF
THE COLD FRONT...AROUND 03Z FRIDAY OVER THE WEST. MORE LIKE
06-09Z OVER THE SERN AREAS. THE CONDITIONS AT BFD AND JST WILL
LIKELY REMAIN MVFR/IFR WITH SNOW SHOWERS INTO FRIDAY.
OUTLOOK...
SAT...VFR.
SUN...LOWER CONDITIONS POSSIBLE OVER SOUTHERN AREAS ASSOCIATED
WITH A STORM MOVING THROUGH THE CAROLINAS.
MON...REDUCED CONDS EARLY IN SNOW SHOWERS. IMPROVING FROM WEST TO
EAST AFTERNOON ONWARD.
TUE...NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 AM EST FRIDAY FOR PAZ004>006-
010-011-017-024-033.
WINTER WEATHER ADVISORY UNTIL 1 AM EST FRIDAY FOR PAZ025>028-
034>036-056-057-059-063>066.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...LAMBERT/MARTIN
AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1141 AM EST THU JAN 29 2015
.SYNOPSIS...
AN ALBERTA CLIPPER WILL CROSS THE AREA THIS AFTERNOON AND
TONIGHT. HIGH PRESSURE WILL RETURN FOR LATE FRIDAY INTO SATURDAY.
A NEW STORM MAY BRING A ROUND OF WINTRY WEATHER FOR LATER SUNDAY
INTO MONDAY...BEFORE ANOTHER SURGE OF COLD AIR WORKS INTO THE AREA
EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CLOUDS CONTINUE TO THICKEN OVER THE REGION AS OF LATE
MORNING...WITH THE FIRST PRECIPITATION REACHING THE GROUND OVER
FAR WESTERN PA IN THE FORM OF SOME SLEET OR FREEZING RAIN.
THE MAIN AREA OF PRECIP IS SHOWN BY THE HRRR TO BE ENTERING MY
WESTERN ZONES BY 18Z/1PM. STILL SOME CONCERN FOR A BRIEF PERIOD OF
LIGHT FREEZING RAIN OR SLEET AT THE ONSET...EVEN OUTSIDE THE
CURRENT ADVISORY AREAS. SNOWFALL TOTALS IN OUR GRIDDED FORECASTS
LOOK REASONABLE AND WE ARE NOT EXPECTING MORE THAN A TRACE OF
ICE...BUT IF IT SHOULD COINCIDE WITH THE EVENING COMMUTE UNTREATED
ROADS COULD POSE TRAVEL PROBLEMS. AT THIS STAGE WE PLAN TO HANDLE
THIS EXPECTED BRIEF PERIOD OF ICE WITH SPECIAL WEATHER
STATEMENTS AND NOWCASTS...AND WILL MONITOR FOR THE POSSIBLE NEED
FOR A HEADLINE PRODUCT.
A STRONG SHOT OF WAA ALOFT AND MODERATELY STG UPPER LEVEL
DIVERGENCE ASSOCIATED WITH THE RIGHT ENTRANCE REGION OF AN UPPER
LVL JET MAX ACROSS SRN ONTARIO WILL LEAD TO PERIODS OF LIGHT TO
BRIEFLY MDT SNOW FOCUSED ACROSS THE NW HALF OF THE STATE THIS
AFTERNOON INTO TONIGHT.
GUIDANCE IS CONSISTENT IN SHOWING WARM AIR SURGING IN ALOFT
TODAY...THEN BEING PINCHED OFF QUICKLY AS PRECIP DEVELOPS AND THE
COLUMN EVAPORATIVELY COOLS. HOWEVER...THE RAP/HRRR HOURLY DATA
SHOW THE WARM AIR ACTUALLY PUSHING BACK NORTH BETWEEN 21-00Z OVER
THE SWRN ZONES...WHICH IF IT COINCIDES WITH ONGOING PRECIP WILL
COMPLICATE THE PRECIP TYPE SCENARIO OVER THE LAURELS AND SOME
MARYLAND BORDER COUNTIES. THE POTENTIAL FOR THE WINTRY MIX IS THE
LOW PROBABILITY OUTCOME AT THIS POINT.
REST FROM EARLIER...
MODEL CONSENSUS REMAINS UNCHANGED TO A LARGE
DEGREE WITH RESPECT TO THE QPF FROM THE CLIPPER SYSTEM MOVING BY
JUST TO OUR NORTH ACROSS LAKES ERIE AND ONTARIO LATE TODAY AND
TONIGHT. A GENERAL 2-4 INCH SNOWFALL IS LIKELY OVER THE
ALLEGHENIES OF WRN PENN WHERE A WINTER WEATHER ADVISORY IS IN
EFFECT FROM LATE THIS MORNING THROUGH 12Z FRIDAY. THE CENTRAL
RIDGE AND VALLEY OF THE STATE WILL 1-2 INCHES BY MIDNIGHT
TONIGHT...WHILE COUNTIES THROUGHOUT THE LOWER SUSQ VALLEY RECEIVE
GENERALLY LESS THAN 0NE INCH. A BIT OF SLEET AND EVEN PATCHY ICE
FROM LIGHT FREEZING RAIN IS POSSIBLE ACROSS SOUTHERN PENN LATE
TODAY AND THIS EVENING AS THE RATHER SHALLOW WEDGE OF WARMER AIR
ALOFT DRIFTS EAST.
HIGHS THIS AFTERNOON WILL REACH THE UPPER 20S TO AROUND FREEZING
IN THE INCREASING/BRISK SW FLOW AHEAD OF THE CLIPPER/ARCTIC FRONT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
THE BRUNT OF THE CURRENT STORM SYSTEM WILL OCCUR LATE THIS
AFTERNOON AND EARLY TONIGHT...WITH SOME BRIEF PERIODS OF MDT SNOW
LIKELY AS ONE OR MORE N/S BANDS OF ENHANCED 850-700 MB UVVEL
CROSSES THE REGION. 03Z SREF INDICATES THAT AN AXIS OF ANOMALOUS
/2-3 SIGMA/ 850MB MOISTURE FLUX AND SIMILARLY ANOMALOUS /50 KT/
SWRLY LLJ WILL BE GRADUALLY WEAKENING AS IT CROSSES PENN BETWEEN
21Z AND 06Z FRI.
SFC COLD FRONT EXTENDING SOUTH FROM THE LOW...PUSHES ACROSS OUR
WESTERN ZONES LATE THIS EVENING...THEN CLEARS THE SUSQ VALLEY
BETWEEN 07-09Z FRIDAY. SNOW WILL TAPER TO SNOW SHOWERS BY LATE
TONIGHT...MAINLY IN THE ISOLATED FORM ACROSS THE CENTRAL AND
SOUTHERN VALLEYS.
LOW TEMPS TONIGHT WILL RANGE FROM THE MID TO UPPER TEENS ACRS THE
WRN MTNS...TO THE MID AND UPPER 20S ACROSS THE SUSQ VALLEY. A
SLIGHTLY EARLIER TIMING OF THE CFROPA WILL KNOCK THESE VALUES DOWN
BY A FEW DEG F.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
PERIODS OF GENERALLY LIGHTER SNOW WILL LINGER INTO EARLY
FRIDAY...AS THE MAIN COLD FRONT DROPS SE.
A TIGHT LLVL PRESSURE GRADIENT IN THE WAKE OF THE COLD FRONT WILL
BRING GUSTY NORTHWEST WINDS AND SLOWLY FALLING TEMPS ACROSS THE
REGION DURING THE DAYLIGHT HOURS FRIDAY. WIND GUSTS WILL BE IN
THE MID TO UPPER 20 KT RANGE FOR MOST AREAS CREATING A WIND CHILL
IN THE SINGLE DIGITS TO LOW TEENS IN THE SUSQ VALLEY....AND 5
BELOW TO 15 BELOW ACROSS THE NRN AND WRN MTNS.
FRIDAY NIGHT WILL BE BITTERLY COLD...AS SKIES CLEAR AND WINDS DIE
DOWN. LOW TEMPS WILL VARY FROM THE SINGLE DIGITS BELOW ZERO ACROSS
THE NORTH...TO SINGLE DIGITS ABOVE ZERO IN THE SOUTH.
A BRIGHT DAY ON SAT...BUT NOT REAL WARM.
STILL HAVE CHC POPS ON SUNDAY. A LOT OF SPREAD IN THE MODEL OUTPUT
THE LAST FEW DAYS. 12Z MODELS BACKING OFF SOME NOW. PATTERN
SUPPORTS LOW PRESSURE SYSTEMS THAT ARE FAST MOVING AND WEAK. WOULD
STILL EXPECT SOME LIGHT SNOW INTO MONDAY MORNING.
A COLD NIGHT MONDAY NIGHT...AS THE NEXT HIGH BUILDS INTO
THE AREA.
SOME HINTS AT ANOTHER FAST MOVING LOW FOR MID WEEK...FOR NOW
WENT WITH CHC POPS.
MINOR CHANGES TO THE PACKAGE MADE.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
VFR WILL CONTINUE INTO EARLY AFTERNOON BEFORE RAPIDLY
DETERIORATING TO MVFR/IFR AS SNOW OVERSPREADS THE FLYING AREA
FROM WEST TO EAST.
SNOW WILL BEGIN AROUND OR SHORTLY AFTER NOON IN BRADFORD. EXPECT
IFR CONDITIONS TO DEVELOP RAPIDLY WITH THE SNOW...SPREADING EAST
18-00Z.
REDUCED CONDITIONS SHOULD IMPROVE OVERNIGHT WITH THE PASSAGE OF
THE COLD FRONT...AROUND 06Z FRIDAY OVER THE WEST. MORE LIKE 09-12Z
OVER THE SERN AREAS. THE CONDITIONS AT BFD AND JST WILL LIKELY
REMAIN MVFR/IFR INTO FRIDAY.
OUTLOOK...
SAT...VFR.
SUN...RESTRICTIONS DEVELOPING WITH SNOW OVERSPREADING FROM THE
WEST.
MON...REDUCED CONDS EARLY IN SNOW. IMPROVING FROM WEST TO EAST
AFTERNOON ONWARD.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 AM EST FRIDAY FOR PAZ004>006-
010-011-017-024-033.
&&
$$
SYNOPSIS...LA CORTE/LAMBERT
NEAR TERM...LA CORTE/LAMBERT
SHORT TERM...LAMBERT
LONG TERM...LAMBERT/MARTIN
AVIATION...CERU/GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
203 AM EST THU JAN 29 2015
.SYNOPSIS...
HIGH PRESSURE WILL MOVE OFF TO THE SOUTHEAST OF THE REGION
TONIGHT...FOLLOWED BY AN ALBERTA CLIPPER WHICH WILL CROSS THE
AREA THURSDAY AND THURSDAY NIGHT. HIGH PRESSURE WILL RETURN FOR
LATE FRIDAY INTO SATURDAY. A NEW STORM MAY BRING A ROUND OF WINTRY
WEATHER FOR LATER SUNDAY INTO MONDAY...BEFORE ANOTHER SURGE OF
COLD AIR WORKS INTO THE AREA EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
CLEAR SKIES...LIGHT WIND AND FRESH SNOW COVER ALLOWING TEMPS TO
FALL QUICKLY THIS EVENING. MESONET SHOWS SOME SUB-ZERO READINGS ALREADY
SHOWING UP ACROSS THE N MTNS AS OF 03Z. BASED ON AFTERNOON DWPTS
AND LATEST RAP OUTPUT...EXPECT THE COLDER VALLEYS OF THE
ALLEGHENIES TO BOTTOM OUT BTWN ZERO AND 10BLW AFTER MIDNIGHT.
UNDER SUCH AN IDEAL RAD COOLING SCENARIO...EXPECT WIDELY VARYING
MIN TEMPS...WITH 15F DIFFERENCES LIKELY WITHIN THE SAME
TOWNSHIPS. HAVE TRIED TO SETTLE ON AVG LOWS...WHICH WILL LKLY
RANGE FROM ARND ZERO ACROSS THE NW MTNS...TO ARND 10 ABV ACROSS
THE LOWER SUSQ VALLEY. WAA ALOFT AND ASSOC CIRRUS SHIELD WILL
LIKELY OVERSPREAD THE AREA FROM THE WEST TOWARD DAWN...RESULTING
IN RISING TEMPS LATE ACROSS THE WESTERN HALF OF THE STATE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM FRIDAY/...
CLOUDS WILL THICKEN QUICKLY THURSDAY WITH WARM ADVECTION PRECIP
OVERSPREADING THE AREA DURING THE AFTERNOON. WE HAVE OPTED FOR A
LOW END ADVISORY FOR OUR WESTERN HIGHER ELEVATION COUNTIES FOR THE
POTENTIAL OF SEVERAL INCHES OF SNOW...WITH THE POSSIBILITY OF A
BRIEF PERIOD OF FREEZING RAIN AT THE ONSET.
MODELS ALL AGREE IN SHOVING A WEDGE OF WARM AIR ALOFT INTO THE
AREA THURSDAY MORNING...BUT FORECAST SOUNDINGS SHOW THE COLUMN
COOLING QUICKLY ONCE PRECIP STARTS SO THE THREAT FOR SIG ICING
WILL BE PRETTY SMALL. THINKING IS THAT A GENERAL 2-4INCH SNOWFALL
IS LIKELY OVER THE RIDGE COUNTIES...WITH A COATING TO PERHAPS AS
MUCH AS 3 INCHES FROM CENTRAL AREAS EASTWARD BEFORE THINGS WIND
DOWN THURSDAY NIGHT OR FRIDAY.
HIGHS THURSDAY WILL MAKE TO THE UPPER 20S TO AROUND FREEZING IN
THE BRISK SW FLOW AHEAD OF THE CLIPPER/ARCTIC FRONT.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
A STRONG SHOT OF WAA ALOFT AND MODERATELY STG UPPER LEVEL
DIVERGENCE ASSOCIATED WITH THE RIGHT ENTRANCE REGION OF AN
UPPER LVL JET MAX ACROSS SRN ONTARIO WILL LEAD TO PERIODS OF
LIGHT /TO BRIEFLY MDT SNOW/ FOCUSED ACROSS THE NW HALF OF THE
STATE LATER THU AFT INTO THURSDAY NIGHT. SOME FREEZING RAIN
COULD MIX IN EARLY...BUT UPWARD MOTION OFFSETS THE WARMING.
FCST TEMPS AT BUF COOLER NOW THAN YESTERDAY. THUS THINK MOST
OF OUR AREA WILL STAY MAINLY BELOW 32 ON THU. SOURCE REGION
OF THE AIRMASS IS FROM THE PLAINS. IT WAS IN THE 70S AND LOWER
80S ACROSS THE SOUTHERN PLAINS YESTERDAY...WARM THERE TODAY TOO.
SNOW WILL LINGER INTO EARLY FRIDAY...AS THE MAIN COLD FRONT DROPS
SE. IT WILL BE WINDY ON FRIDAY.
FRIDAY NIGHT WILL BE COLD...AS SKIES CLEAR AND WINDS DIE DOWN.
A BRIGHT DAY ON SAT...BUT NOT REAL WARM.
STILL HAVE CHC POPS ON SUNDAY. A LOT OF SPREAD IN THE MODEL OUTPUT
THE LAST FEW DAYS. 12Z MODELS BACKING OFF SOME NOW. PATTERN
SUPPORTS LOW PRESSURE SYSTEMS THAT ARE FAST MOVING AND WEAK. WOULD
STILL EXPECT SOME LIGHT SNOW INTO MONDAY MORNING.
A COLD NIGHT MONDAY NIGHT...AS THE NEXT HIGH BUILDS INTO
THE AREA.
SOME HINTS AT ANOTHER FAST MOVING LOW FOR MID WEEK...FOR NOW
WENT WITH CHC POPS.
MINOR CHANGES TO THE PACKAGE MADE.
&&
.AVIATION /07Z THURSDAY THROUGH MONDAY/...
HIGH PRESSURE WILL MOVE EAST ACROSS THE STATE OVERNIGHT....BRINGING
WIDESPREAD VFR CONDITIONS. THE ONLY CAVEAT IS THE POSSIBILITY FOR
MVFR VSBYS AT BFD.
THURSDAY WILL BRING INCREASING CLOUDINESS WITH CONDITIONS
DETERIORATING IN SNOW STARTING AROUND MID DAY OVER WESTERN
TERMINALS...SPREADING RAPIDLY EAST THROUGH MID AFTERNOON.
REDUCED CONDITIONS WILL CONTINUE INTO EARLY FRIDAY.
OUTLOOK...
FRI...CONDITIONS IMPROVING DURING THE DAY...BUT REMAINING MVFR
OVER THE HIGHER ELEVATION TERMINALS OF THE WEST AND NORTH.
SAT...VFR.
SUN...RESTRICTIONS DEVELOPING WITH SNOW OVERSPREADING FROM THE
WEST.
MON...REDUCED CONDS EARLY IN SNOW. IMPROVING FROM WEST TO EAST
AFTERNOON ONWARD.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 11 AM THIS MORNING TO 7 AM EST
FRIDAY FOR PAZ004>006-010-011-017-024-033.
&&
$$
SYNOPSIS...FITZGERALD/LA CORTE
NEAR TERM...FITZGERALD
SHORT TERM...LA CORTE
LONG TERM...MARTIN
AVIATION...CERU/GARTNER
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1258 PM EST THU JAN 29 2015
.SYNOPSIS...
IN THE WAKE OF A COLD FRONTAL PASSAGE...HIGH PRESSURE WILL BUILD
INTO THE REGION LATER ON FRIDAY. THE HIGH WILL LINGER OVER THE AREA
INTO SUNDAY BEFORE MOISTURE RETURNS OUT AHEAD OF A DEVELOPING
LOW PRESSURE SYSTEM. DRY CANADIAN HIGH MOVES BACK INTO THE AREA BY
TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
1240 PM EST UPDATE...LATEST MESO-SCALE MODELS WERE HANDLING WELL
WITH THE BAND OF PRECIP CROSSING THE NC MTNS ZONES AS OF EARLY THIS
AFTERNOON. HENCE...HAVE BLENDED WITH THE CAMPOP FEATURING LIKELY
POPS OVER THE RIDGE TOPS OF THE BLUE RIDGE. ALSO...HAVE CARRIED A
MIX OF RAIN AND SNOW OVER PORTIONS OF THE NORTHERN NC MTNS/VALLEYS
AS TEMPS STRUGGLE TO WARM UP ABOVE 40S.
1000 EST THURSDAY UPDATE...LATEST SURROUNDING REGIONAL RADARS SHOW A
BAND OF LIGHT RETURNS WAS APPROACHING THE SOUTHERN APPALACHIANS FROM
THE TN VALLEY AS OF THIS MORNING. LATEST HRRR AND OTHER MESOSCALE
MODELS INDICATE THAT THIS BAND OF LIGHT PRECIP ASSOCIATED WITH AN
UPPER WAVE WILL MOVE EAST ACROSS THE NC MTN ZONES BETWEEN 16-18Z AND
ACROSS THE NC FOOTHILLS AND PORTIONS OF THE NORTHERN NC PIEDMONT
18-20Z. THEREFORE...POPS WERE UPDATED TO ACCOUNT FOR THIS THRU THIS
AFTERNOON. HOWEVER...PRECIP AMOUNTS APPEAR TO BE VERY LIGHT GIVEN
RELATIVELY DRY AIRMASS AND SHALLOW MOIST LAYER. NO WINTRY P-TYPE IS
EXPECTED THRU THIS AFTERNOON GIVEN GOOD WARMING TREND.
1115 UTC UPDATE...WINDS WERE UPDATED WITH A TWO TO ONE BLEND OF THE
NAM AND ADJMAV...FAVORING THE FORMER FOR STRINGER WINDS AND GUSTS IN
THE MOUNTAINS...BOTH AHEAD OF AND BEHIND THE APPROACHING COLD FRONT.
GUSTS STILL APPEAR TO REACH ADVISORY CRITERIA ONLY AT THE VERY
HIGHEST MOUNTAIN PEAKS LATE TONIGHT...SO NO ADVISORY IS PLANED AT
THIS TIME. SKY COVER WAS UPDATED FROM INFRARED SATELLITE IMAGERY.
AT 230 AM EST THURSDAY...AN UPPER RIDGE OF MODEST AMPLITUDE WILL
CROSS THE EASTERN SEABOARD THIS MORNING...WHILE AND UPPER TROUGH
MOVES FROM THE MS RIVER VALLEY TO THE OH AND TN RIVER VALLEYS. A
SHORTWAVE MOVING THROUGH THIS TROUGH WILL REACH THE CENTRAL
APPALACHIANS BY MIDDAY. THE RIDGE MOVES TO THE GULF STREAM THIS
AFTERNOON...WHILE THE SHORTWAVE MOVES OFF THE MID ATLANTIC COAST.
ANOTHER AND MORE ROBUST SHORTWAVE MOVING THROUGH THE TROUGH REACHES
THE CENTRAL AND SOUTHERN APPALACHIANS IN THE MIDDLE OF THURSDAY
NIGHT...MOVING EAST OF OUR AREA BY MORNING....WHILE THE TROUGH AXIS
REACHES THE EAST COAST.
A SURFACE RIDGE ALONG THE EAST COAST WILL MOVE OFFSHORE TODAY...
WHILE A COLD FRONT MOVES FROM THE MS RIVER VALLEY TO THE
APPALACHIANS. PRECIPITATION AHEAD OF THE FRONT WILL REACH THE
MOUNTAINS SOMETIME THIS MORNING...PERHAPS EARLY ENOUGH TO START AS
LIGHT SNOW. WITH WARMING...SNOW LEVELS RISE ABOVE THE MOUNTAIN TOPS
TODAY. NO APPRECIABLE SNOW ACCUMULATIONS ARE EXPECTED THIS MORNING.
THE MODELS DO NOT SHOW MUCH DEPTH TO THE MOIST LAYER EAST OF THE
BLUE RIDGE...AND PRECIPITATION CHANCES ARE QUITE LIMITED THERE.
FRONTAL PASSAGE TAKES PLACE OVERNIGHT...WITH DOWNSLOPE DRYING IN THE
LEE OF THE MOUNTAINS...AND MOIST NW FLOW INTO THE NC MOUNTAINS
BORDERING TN. SNOW LEVEL ARE EXPECTED TO FALL TO THE VALLEY FLOORS
THIS EVENING...WHILE COVERAGE RETREATS CLOSER TO THE TN BORDER.
RIGHT NOW IT APPEARS THAT SNOWFALL ACCUMULATIONS WILL RUN JUST UNDER
TWO INCHES OVERNIGHT...BUT ADVISORY CRITERIA WILL ONLY BE APPROACHED
ON THE VERY HIGHEST PEAKS...SO NO SNOW ADVISORY IS PLANNED. WINDS
WILL INCREASE IN THE TIGHT PRESSURE GRADIENT BEHIND THE FRONT...BUT
WIND ADVISORY CRITERIA WILL ONLY BE REACHED LATE TONIGHT ON PEAKS
OVER 5000 FT...SO NO WIND ADVISORY IS PLANNED AT THIS TIME.
HIGH TEMPERATURES WILL RUN NEAR NORMAL TODAY AS WARM ADVECTION UNDER
THE UPPER RIDGE IS OFFSET BY INCREASING CLOUD COVER...AND LOW
TEMPERATURES TONIGHT WILL RUN SLIGHTLY ABOVE NORMAL AS WINDS KEEP
THE ATMOSPHERE MIXED.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 115 AM THURSDAY...THE SHORT TERM BEGINS WITH AN INCREASING
SUBSIDENCE ZONE AND A WANING NWFS EVENT. DRY CP AIR WILL BEGIN
FILTERING INTO THE MTNS AND LIMIT THE ADDITIONAL SNOWFALL POTENTIAL.
LIKELY AROUND ANOTHER HALF TO ONE INCH THROUGH 21Z ACROSS WRN MTN
SPINE. GOOD H85 CAA ALONG WITH DEEP SUBSIDENCE WILL CONTINUE THE
STRONG WINDS/GUSTS ACROSS THE NC MTNS...WITH ADVISORY OR EVEN
WARNING CRITERIA BEING MET ABOVE 4000 FEET AS MODEL SOUNDINGS
INDICATE AN UPWARD TREND IN VELOCITIES ATOP THE MIXED LAYER THROUGH
MID AFTERNOON. WILL KEEP THE HWO MENTION FOR NOW AND THE DAY SHIFT
WILL LIKELY ISSUE THE NPW AS THE EVENT MOVES INTO THE 2ND PERIOD.
WINDS WILL RELAX SLOWLY THROUGH THE EVENING WITH A GOOD H85 TGRAD
EVENTUALLY LOOSENING AFT 00Z. MAX TEMPS WILL ABOUT 15 DEGREES BELOW
NORMAL MTN VALLEYS AND 3-5 DEGREES BELOW NORMAL NON/MTNS. HEIGHTS
BEGIN TO RISE FRI NIGHT AND FLAT RIDGING WILL BE IN PLACE BY SAT
AFTERNOON. THIS WILL ENABLE THE CP SFC HIGH TO CROSS THE FA
THROUGH THE PERIOD BECOMING SITUATED OFF THE CAROLINA COAST BY 12Z
SUN. THUS...SKIES WILL CLEAR AND TEMPS WILL REMAIN A FEW DEGREES
BELOW NORMAL AS A LLVL THETA/E TROF MIXES IN.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 255 AM THURSDAY MORNING...THE MEDIUM RANGE FCST PICKS UP AT
12Z ON SUNDAY WITH RELATIVELY ZONAL UPPER FLOW OVER THE CAROLINAS
AND A DEEPENING UPPER TROF TO OUR WEST. OVER THE NEXT 24 TO 36
HRS...THE TROF AXIS IS EXPECTED TO PASS OVERHEAD WITH MORE ZONAL
FLOW IN ITS WAKE. DURING THIS PERIOD...A SOUTHERN STREAM H5 LOW
SPINS UP OVER THE BAJA PENINSULA AND GRADUALLY DRIFTS NE TOWARDS OUR
AREA. BY THE END OF THE MEDIUM RANGE...THIS LOW WILL LIKELY GET
ABSORBED BY ANOTHER DEEPENING UPPER TROF.
AT THE SFC...HIGH PRESSURE WILL BE MOVING OFF THE SE COAST EARLY
SUNDAY AS ANOTHER LOW SPINS UP TO OUR WSW OVER THE LOWER MISS RIVER
VALLEY. THE ASSOCIATED BROAD AREA OF DEEP LYR MOISTURE WILL SPREAD
OVER THE REGION THRU THE DAY WITH OVERCAST CONDITIONS AND LIKELY
POPS BY LATE SUN/EARLY MON FOR PRETTY MUCH ALL ZONES. THE GFS
REMAINS ABOUT 12 HRS FASTER WITH THE DEVELOPMENT OF THIS SYSTEM
COMPARED TO THE ECMWF AND CMC. IN THE LOWS WAKE...ANOTHER CANADIAN
HIGH PUSHES BACK INTO THE REGION FROM THE NW ON MON AND DRIES THINGS
OUT. THE CENTER OF THE HIGH WILL PASS OVER THE AREA ON TUES AND MOVE
OFFSHORE BY EARLY WED. BEYOND THIS POINT THE MODEL GUIDANCE REMAINS
FAIRLY AMBIGUOUS WITH THE SYNOPTIC PATTERN. THE GFS BRINGS ANOTHER
REINFORCING CANADIAN HIGH DOWN OVER THE REGION ON THURS AND KEEPS
THINGS DRY. THE ECMWF TRIES TO SPIN UP ANOTHER MILLER A TYPE LOW
OVER THE NORTHERN GULF OF MEX ON WED AND MOVE THE SYSTEM ACROSS THE
CAROLINA COAST LATE WED/EARLY THURS AND AFTER THAT...IT DRIES THINGS
OUT LIKE THE GFS. THE PREVIOUS RUNS OF THE GFS HINTED MORE TOWARDS
THE MILLER A TYPE LOW DEVELOPING...SO THE CURRENT DRY SCENARIO LOOKS
QUESTIONABLE. AS FOR THE SENSIBLE FCST...I TRENDED A BIT COOLER FOR
THE MON/TUES PERIOD WITH LOWS EARLY TUES IN THE LOW TO MID 20S
ACROSS THE THE LOWER ELEVATIONS AND TEENS ACROSS THE HIGHER TERRAIN.
POP TRENDS WERE NOT CHANGED MUCH FOR THE FIRST HALF OF THE PERIOD
WITH BEST CHANCES LATE SUN THRU EARLY MON. FOR TUES/WED...I KEPT
POPS AT SLIGHT TO SOLID CHANCE DUE TO THE CONTINUING UNCERTAINTY
WITH THE GULF LOW.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AT KCLT...EXPECT VFR CONDITIONS TO PERSIST THROUGH 18Z FRIDAY. A
LIGHT BAND OF PRECIP ASSOCIATED WITH A WEAK UPPER WAVE WILL CROSS
THE NC MTNS THROUGH THIS AFTERNOON. HOWEVER...LATEST MESO-MODELS
INDICATE THAT THIS FEATURE WILL WEAKEN CONSIDERABLY AS IT ENTERS THE
NC FOOTHILLS/PIEDMONT BY EARLY THIS AFTERNOON. SO NO PRECIP WAS
MENTIONED IN THE TAF. SW WINDS SHOULD PERSIST WITH OCCASIONAL GUSTS
TO AROUND 15-20KTS POSSIBLE THRU THIS AFTERNOON. TONIGHT...SW WINDS
SHOULD TO VEER TO THE NW AS A SURFACE COLD FRONT PUSHES THROUGH THE
REGION. AS SURFACE PRESSURE TIGHTENS UP BEHIND THE FRONT...GUSTY NW
WINDS OF 15-20KTS WILL DEVELOP BY AROUND 15Z. CLOUD CIGS WILL BOTTOM
OUT AROUND 8K FT DURING THE FROPA TONIGHT.
ELSEWHERE...VFR THROUGH THE PERIOD EXCEPT KAVL WHERE MVFR CLOUDS
WILL SPREAD IN FROM THE NORTH TONIGHT DUE TO THE FROPA. A LIGHT BAND
OF PRECIP WILL MOVE ACROSS THE NC MTN ZONES THROUGH THIS AFTERNOON.
HOWEVER...THE PRECIP APPEARS TO BE VERY LIGHT AND IT WILL BE MAINLY
CONFINED TO THE RIDGE TOPS OF THE MTNS. HENCE...NO PRECIP WAS
MENTIONED IN KAVL. OTHERWISE...EXPECT MOSTLY CLOUDY SKIES WITH SW
WINDS PERSISTING THROUGH LATE THIS EVENING ACROSS MUCH OF THE
REGION. WINDS WILL VEER THE NW TONIGHT AS A SURFACE COLD FRONT
PUSHES THROUGH THE AREA. AGAIN...PRECIP CHANCES ARE TOO LOW TO
MENTION IN THE TAF. TIGHT PRESSURE GRADIENT BEHIND THE FRONT WILL
RESULT IN GUSTY NW WINDS ACROSS MUCH OF THE REGION BY FRI MORNING.
OUTLOOK...A PAIR OF CLIPPER SYSTEMS WILL BRING CHANCES FOR RAIN OR
SNOW SHOWERS TO THE NC MTNS FRI. MOST OF THESE SHOWERS WILL REMAIN
WEST AND NORTH OF KAVL...BUT BRIEF PERIODS OF RESTRICTIONS CANNOT BE
RULED OUT. OTHERWISE...MAINLY VFR CONDITIONS ARE EXPECTED ACROSS THE
AREA UNTIL MOISTURE BEGINS TO RETURN SUNDAY. DRYING IS EXPECTED ON
MONDAY.
CONFIDENCE TABLE...
18-24Z 00-06Z 06-12Z 12-18Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 96% HIGH 81% MED 60%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JPT
NEAR TERM...JAT/JOH
SHORT TERM...SBK
LONG TERM...JPT
AVIATION...JOH
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1017 AM EST THU JAN 29 2015
.SYNOPSIS...
A COLD FRONT WILL CROSS THE FORECAST AREA LATER TONIGHT WITH HIGH
PRESSURE BUILDING IN ITS WAKE ON FRIDAY. THE HIGH WILL LINGER OVER
THE REGION INTO SUNDAY BEFORE A MOIST LOW PRESSURE SYSTEM DEVELOPS
TO OUR SOUTHWEST AND BRINGS WIDESPREAD PRECIPITATION TO THE AREA
LATE SUNDAY AND MONDAY. ANOTHER CANADIAN HIGH MOVES BACK INTO THE
AREA LATE MONDAY AND LINGERS INTO MIDWEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
1000 EST THURSDAY UPDATE...LATEST SURROUNDING REGIONAL RADARS SHOW A
BAND OF LIGHT RETURNS WAS APPROACHING THE SOUTHERN APPALACHIANS FROM
THE TN VALLEY AS OF THIS MORNING. LATEST HRRR AND OTHER MESOSCALE
MODELS INDICATE THAT THIS BAND OF LIGHT PRECIP ASSOCIATED WITH AN
UPPER WAVE WILL MOVE EAST ACROSS THE NC MTN ZONES BETWEEN 16-18Z AND
ACROSS THE NC FOOTHILLS AND PORTIONS OF THE NORTHERN NC PIEDMONT
18-20Z. THEREFORE...POPS WERE UPDATED TO ACCOUNT FOR THIS THRU THIS
AFTERNOON. HOWEVER...PRECIP AMOUNTS APPEAR TO BE VERY LIGHT GIVEN
RELATIVELY DRY AIRMASS AND SHALLOW MOIST LAYER. NO WINTRY P-TYPE IS
EXPECTED THRU THIS AFTERNOON GIVEN GOOD WARMING TREND.
1115 UTC UPDATE...WINDS WERE UPDATED WITH A TWO TO ONE BLEND OF THE
NAM AND ADJMAV...FAVORING THE FORMER FOR STRINGER WINDS AND GUSTS IN
THE MOUNTAINS...BOTH AHEAD OF AND BEHIND THE APPROACHING COLD FRONT.
GUSTS STILL APPEAR TO REACH ADVISORY CRITERIA ONLY AT THE VERY
HIGHEST MOUNTAIN PEAKS LATE TONIGHT...SO NO ADVISORY IS PLANED AT
THIS TIME. SKY COVER WAS UPDATED FROM INFRARED SATELLITE IMAGERY.
AT 230 AM EST THURSDAY...AN UPPER RIDGE OF MODEST AMPLITUDE WILL
CROSS THE EASTERN SEABOARD THIS MORNING...WHILE AND UPPER TROUGH
MOVES FROM THE MS RIVER VALLEY TO THE OH AND TN RIVER VALLEYS. A
SHORTWAVE MOVING THROUGH THIS TROUGH WILL REACH THE CENTRAL
APPALACHIANS BY MIDDAY. THE RIDGE MOVES TO THE GULF STREAM THIS
AFTERNOON...WHILE THE SHORTWAVE MOVES OFF THE MID ATLANTIC COAST.
ANOTHER AND MORE ROBUST SHORTWAVE MOVING THROUGH THE TROUGH REACHES
THE CENTRAL AND SOUTHERN APPALACHIANS IN THE MIDDLE OF THURSDAY
NIGHT...MOVING EAST OF OUR AREA BY MORNING....WHILE THE TROUGH AXIS
REACHES THE EAST COAST.
A SURFACE RIDGE ALONG THE EAST COAST WILL MOVE OFFSHORE TODAY...
WHILE A COLD FRONT MOVES FROM THE MS RIVER VALLEY TO THE
APPALACHIANS. PRECIPITATION AHEAD OF THE FRONT WILL REACH THE
MOUNTAINS SOMETIME THIS MORNING...PERHAPS EARLY ENOUGH TO START AS
LIGHT SNOW. WITH WARMING...SNOW LEVELS RISE ABOVE THE MOUNTAIN TOPS
TODAY. NO APPRECIABLE SNOW ACCUMULATIONS ARE EXPECTED THIS MORNING.
THE MODELS DO NOT SHOW MUCH DEPTH TO THE MOIST LAYER EAST OF THE
BLUE RIDGE...AND PRECIPITATION CHANCES ARE QUITE LIMITED THERE.
FRONTAL PASSAGE TAKES PLACE OVERNIGHT...WITH DOWNSLOPE DRYING IN THE
LEE OF THE MOUNTAINS...AND MOIST NW FLOW INTO THE NC MOUNTAINS
BORDERING TN. SNOW LEVEL ARE EXPECTED TO FALL TO THE VALLEY FLOORS
THIS EVENING...WHILE COVERAGE RETREATS CLOSER TO THE TN BORDER.
RIGHT NOW IT APPEARS THAT SNOWFALL ACCUMULATIONS WILL RUN JUST UNDER
TWO INCHES OVERNIGHT...BUT ADVISORY CRITERIA WILL ONLY BE APPROACHED
ON THE VERY HIGHEST PEAKS...SO NO SNOW ADVISORY IS PLANNED. WINDS
WILL INCREASE IN THE TIGHT PRESSURE GRADIENT BEHIND THE FRONT...BUT
WIND ADVISORY CRITERIA WILL ONLY BE REACHED LATE TONIGHT ON PEAKS
OVER 5000 FT...SO NO WIND ADVISORY IS PLANNED AT THIS TIME.
HIGH TEMPERATURES WILL RUN NEAR NORMAL TODAY AS WARM ADVECTION UNDER
THE UPPER RIDGE IS OFFSET BY INCREASING CLOUD COVER...AND LOW
TEMPERATURES TONIGHT WILL RUN SLIGHTLY ABOVE NORMAL AS WINDS KEEP
THE ATMOSPHERE MIXED.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 115 AM THURSDAY...THE SHORT TERM BEGINS WITH AN INCREASING
SUBSIDENCE ZONE AND A WANING NWFS EVENT. DRY CP AIR WILL BEGIN
FILTERING INTO THE MTNS AND LIMIT THE ADDITIONAL SNOWFALL POTENTIAL.
LIKELY AROUND ANOTHER HALF TO ONE INCH THROUGH 21Z ACROSS WRN MTN
SPINE. GOOD H85 CAA ALONG WITH DEEP SUBSIDENCE WILL CONTINUE THE
STRONG WINDS/GUSTS ACROSS THE NC MTNS...WITH ADVISORY OR EVEN
WARNING CRITERIA BEING MET ABOVE 4000 FEET AS MODEL SOUNDINGS
INDICATE AN UPWARD TREND IN VELOCITIES ATOP THE MIXED LAYER THROUGH
MID AFTERNOON. WILL KEEP THE HWO MENTION FOR NOW AND THE DAY SHIFT
WILL LIKELY ISSUE THE NPW AS THE EVENT MOVES INTO THE 2ND PERIOD.
WINDS WILL RELAX SLOWLY THROUGH THE EVENING WITH A GOOD H85 TGRAD
EVENTUALLY LOOSENING AFT 00Z. MAX TEMPS WILL ABOUT 15 DEGREES BELOW
NORMAL MTN VALLEYS AND 3-5 DEGREES BELOW NORMAL NON/MTNS. HEIGHTS
BEGIN TO RISE FRI NIGHT AND FLAT RIDGING WILL BE IN PLACE BY SAT
AFTERNOON. THIS WILL ENABLE THE CP SFC HIGH TO CROSS THE FA
THROUGH THE PERIOD BECOMING SITUATED OFF THE CAROLINA COAST BY 12Z
SUN. THUS...SKIES WILL CLEAR AND TEMPS WILL REMAIN A FEW DEGREES
BELOW NORMAL AS A LLVL THETA/E TROF MIXES IN.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 255 AM THURSDAY MORNING...THE MEDIUM RANGE FCST PICKS UP AT
12Z ON SUNDAY WITH RELATIVELY ZONAL UPPER FLOW OVER THE CAROLINAS
AND A DEEPENING UPPER TROF TO OUR WEST. OVER THE NEXT 24 TO 36
HRS...THE TROF AXIS IS EXPECTED TO PASS OVERHEAD WITH MORE ZONAL
FLOW IN ITS WAKE. DURING THIS PERIOD...A SOUTHERN STREAM H5 LOW
SPINS UP OVER THE BAJA PENINSULA AND GRADUALLY DRIFTS NE TOWARDS OUR
AREA. BY THE END OF THE MEDIUM RANGE...THIS LOW WILL LIKELY GET
ABSORBED BY ANOTHER DEEPENING UPPER TROF.
AT THE SFC...HIGH PRESSURE WILL BE MOVING OFF THE SE COAST EARLY
SUNDAY AS ANOTHER LOW SPINS UP TO OUR WSW OVER THE LOWER MISS RIVER
VALLEY. THE ASSOCIATED BROAD AREA OF DEEP LYR MOISTURE WILL SPREAD
OVER THE REGION THRU THE DAY WITH OVERCAST CONDITIONS AND LIKELY
POPS BY LATE SUN/EARLY MON FOR PRETTY MUCH ALL ZONES. THE GFS
REMAINS ABOUT 12 HRS FASTER WITH THE DEVELOPMENT OF THIS SYSTEM
COMPARED TO THE ECMWF AND CMC. IN THE LOWS WAKE...ANOTHER CANADIAN
HIGH PUSHES BACK INTO THE REGION FROM THE NW ON MON AND DRIES THINGS
OUT. THE CENTER OF THE HIGH WILL PASS OVER THE AREA ON TUES AND MOVE
OFFSHORE BY EARLY WED. BEYOND THIS POINT THE MODEL GUIDANCE REMAINS
FAIRLY AMBIGUOUS WITH THE SYNOPTIC PATTERN. THE GFS BRINGS ANOTHER
REINFORCING CANADIAN HIGH DOWN OVER THE REGION ON THURS AND KEEPS
THINGS DRY. THE ECMWF TRIES TO SPIN UP ANOTHER MILLER A TYPE LOW
OVER THE NORTHERN GULF OF MEX ON WED AND MOVE THE SYSTEM ACROSS THE
CAROLINA COAST LATE WED/EARLY THURS AND AFTER THAT...IT DRIES THINGS
OUT LIKE THE GFS. THE PREVIOUS RUNS OF THE GFS HINTED MORE TOWARDS
THE MILLER A TYPE LOW DEVELOPING...SO THE CURRENT DRY SCENARIO LOOKS
QUESTIONABLE. AS FOR THE SENSIBLE FCST...I TRENDED A BIT COOLER FOR
THE MON/TUES PERIOD WITH LOWS EARLY TUES IN THE LOW TO MID 20S
ACROSS THE THE LOWER ELEVATIONS AND TEENS ACROSS THE HIGHER TERRAIN.
POP TRENDS WERE NOT CHANGED MUCH FOR THE FIRST HALF OF THE PERIOD
WITH BEST CHANCES LATE SUN THRU EARLY MON. FOR TUES/WED...I KEPT
POPS AT SLIGHT TO SOLID CHANCE DUE TO THE CONTINUING UNCERTAINTY
WITH THE GULF LOW.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
AT KCLT...VFR. A HIGH LEVEL CIRRUS CIG WILL SPREAD EAST OVER THE
FIELD THIS TODAY AHEAD OF A COLD FRONT. GUIDANCE HAS BACKED OFF
SUPPORT FOR A LOW VFR CIG THIS EVENING...INSTEAD PREFERRING A MID
LEVEL CIG...BEFORE EROSION LATE TONIGHT. SOME LOW CLOUDS WILL BE
CARRIED BENEATH HOWEVER. EVENING PRECIPITATION CHANCES STILL APPEAR
TOO LOW TO MENTION AT THIS TIME. S WINDS WILL COME UP THIS MORNING
VEERING SW THIS AFTERNOON...WITH GUSTS INCREASING. FRONTAL
PASSAGE AND NW WINDS WILL LATE TONIGHT.
ELSEWHERE...HIGH LEVEL CIRRUS CIGS WILL SET UP THIS MORNING IN
ADVANCE OF A COLD FRONT. CIGS FALL TO LOW VFR THIS EVENING AT KAVL
AND KAND...BUT GUIDANCE IS LESS CERTAIN AT KHKY...KGSP AND
KGMU...WHERE A MID LEVEL CIG IS INDICATED. AT THE LAST THREE
SITES...LOW CLOUDS WILL BE CARRIED BENEATH THE CIG. THE CIG FALLS TO
MVFR AT KAVL LATE TONIGHT IN MOIST NW FLOW BEHIND THE FRONT.
PRECIPITATION CHANCES AHEAD OF THE FRONT WILL TOO LOW TO
MENTION...ALTHOUGH KAVL WILL BE A CLOSE CALL. IF SOME SNOW CAN FALL
AT KAVL BEHIND THE FRONT LATE TONIGHT...VSBY MIGHT BE REDUCED...BUT
CONFIDENCE IS TOO LOW FOR A MENTION AT THIS TIME. S WINDS ARE
EXPECTED AFTER DAWN...THEN SW BY MIDDAY...WITH GUSTS INCREASING.
KAVL WINDS VEER NW THIS EVENING AS THE FRONT MOVES THROUGH...AND
FOOTHILLS WINDS FOLLOW SUIT LATE TONIGHT.
OUTLOOK...A PAIR OF CLIPPER SYSTEMS WILL BRING CHANCES FOR RAIN OR
SNOW SHOWERS TO THE NC MTNS FRI. MOST OF THESE SHOWERS WILL REMAIN
WEST AND NORTH OF KAVL...BUT BRIEF PERIODS OF RESTRICTIONS CANNOT BE
RULED OUT. OTHERWISE...MAINLY VFR CONDITIONS ARE EXPECTED ACROSS THE
AREA UNTIL MOISTURE BEGINS TO RETURN SUNDAY. DRYING IS EXPECTED ON
MONDAY.
CONFIDENCE TABLE...
15-21Z 21-03Z 03-09Z 09-12Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 100% HIGH 92% MED 75%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JPT
NEAR TERM...JAT/JOH
SHORT TERM...SBK
LONG TERM...JPT
AVIATION...JAT
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
550 PM CST FRI JAN 30 2015
.DISCUSSION...SEE AVIATION SECTION FOR 00Z TAFS.
&&
.AVIATION...LOWER CLOUD LAYER OVER THE GULF MUCH OF THE DAY HAS MOVED
INTO THE COASTAL BEND LATE THIS AFTERNOON AS LOW LEVEL WINDS VEERED
TO MORE EASTERLY. EXPECT LOWER END MVFR CEILINGS WILL CONTINUE TO
ADVECT WESTWARD AND REACH LRD AROUND 04Z. IT WILL TAKE A BIT LONGER
TO REACH THE NORTHERN COUNTIES. HAVE MVFR CIGS REACHING VCT AREA
AROUND 09Z. THERE COULD BE A PERIOD FROM 09-10Z UNTIL 15-16Z WHEN
IFR CIGS/MVFR VSBYS WILL BE POSSIBLE OVER THE COASTAL BEND INTO THE
SOUTHERN BRUSH COUNTRY. SOUTHEASTERLY LOW LEVEL FLOW WILL INCREASE
TO AROUND 30 KNOTS LATE TONIGHT THROUGH THE DAY SATURDAY. BEST LOW
LEVEL WARM AIR ADVECTION AND MOISTURE FIELD WILL BE OVER THE BRUSH
COUNTRY WITH THE BEST CHANCE FOR SCATTERED SHOWERS NORTHWEST OF A
LAREDO TO BEEVILLE LINE SATURDAY. EXPECT SOUTHEAST WINDS WILL
INCREASE AND BECOME GUSTY BY LATE MORNING INTO THE AFTERNOON. CIGS
SHOULD LIFT/IMPROVE TO AROUND 2500 FEET OVER THE COASTAL PLAINS
WHILE VFR CONDITIONS ARE EXPECTED OVER THE BRUSH COUNTRY SATURDAY
AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 454 PM CST FRI JAN 30 2015/
DISCUSSION...HAVE ISSUED A SMALL CRAFT ADVISORY FOR PORTIONS OF
THE MIDDLE TEXAS COASTAL WATERS FOR THE REMAINDER OF THIS
AFTERNOON AND INTO PART OF THE EVENING. LATEST RAP AND NAM
GUIDANCE INDICATES WIND SPEEDS SHOULD REMAIN STRONG ENOUGH INTO
THE EARLY EVENING HOURS TO JUSTIFY A SCA. ALSO LOWERED MIN TEMPS
FOR PORTIONS OF THE COASTAL COUNTIES AND BARRIER ISLANDS AS
CURRENT TEMPS ARE ALREADY AT OR BELOW PREVIOUSLY FORECAST MINS.
NO OTHER CHANGES OF SIGNIFICANCE MADE AT THIS TIME.
PREV DISCUSSION... /ISSUED 314 PM CST FRI JAN 30 2015/
SHORT TERM (TONIGHT THROUGH SATURDAY NIGHT)...MOISTURE CONTINUES
TO INCREASE ACROSS ALL OF SOUTH TEXAS ON AN EAST TO SOUTHEAST WIND
JUST ABOVE THE SURFACE. PWATS NOW BETWEEN 1.1 AND 1.2 INCHES OVER
THE REGION. MOST OF THIS MOISTURE IS STILL CONFINED TO THE LOWEST
LAYERS AND WILL TAKE SOME TIME FOR THE VERY DRY AIR ALOFT TO
MOISTEN. THIS IS THE REASON CLOUDS HAVE BEEN LESS THAN ANTICIPATED
TODAY...JUST ACROSS THE BORDER IN MEXICO OVERCAST SKIES ARE NOTED
ON VIS SATELLITE...BUT AS THEY HAVE TRIED TO PUSH EASTWARD...MUCH
OF THE CLOUD COVER HAS DISSIPATED. STILL EXPECT CLOUDS TO DEVELOP
LATE THIS EVENING AND THEN CONTINUE THROUGH THE NIGHT AND
TOMORROW. SOME MODELS DO INDICATE CLEARING FOR EASTERN COUNTIES
TOMORROW MORNING...BUT LEANING MORE TOWARD THE CLOUDY SOLUTIONS.
RAIN WILL ALSO BE SLOW TO PUSH EASTWARD...HAVE SLOWED POP
INCREASES A BIT TONIGHT AND DURING THE DAY ON SATURDAY...WITH RAIN
MAINLY IN WESTERN COUNTIES IN THE MORNING...GRADUALLY SHIFTING
EASTWARD BY MID/LATE AFTERNOON. BEST DYNAMICS WITH THIS
APPROACHING SYSTEM WILL BE SATURDAY NIGHT WHEN UPPER LEVEL
SHORTWAVE PASSES...AND NOSE OF UPPER JET INCHES IN. THIS PERIOD IS
WHERE HIGHEST POPS WILL BE NOTED...AS WELL AS A SLIGHT CHANCE FOR
THUNDERSTORMS.
EXPECT MAINLY MILD TEMPERATURES THROUGH THE SHORT TERM PERIOD WITH
CLOUD COVER KEEPING MIN TEMPS INTO THE 50S BOTH TONIGHT AND TOMORROW
NIGHT. THINK HIGHS TOMORROW WILL BE SIMILAR TO TODAY...IN THE UPPER
60S TO AROUND 70.
LONG TERM (SUNDAY THROUGH FRIDAY)...CONCUR WITH THE GFS/ECMWF THAT
AN UPPER SYSTEM WL MOVE ACRS THE PLAINS AT THE BEGINNING OF THE
PERIOD AND CONTRIBUTE TO A COLD FRONT ACRS THE CWA/MSA SUNDAY/SUNDAY
NIGHT. EXPECT THE COMBINATION OF THE FRONT...ABOVE NORMAL PWAT
VALUES (GFS DETERMINISTIC)...AND UPPER JET DYNAMICS (GFS
DETERMINISTIC) TO GENERATE AT LEAST SCT CONVECTION OVER THE REGION
SUNDAY. SCA CONDITIONS ARE EXPECTED OVER THE MSA SUNDAY NIGHT/MONDAY
AFTER FROPA. ANTICIPATE THAT PCPN WL CONTINUE AFTER FROPA THROUGH
EARLY MONDAY OWING TO UPPER JET DYNAMICS. THE GFS/ECMWF PROG ANOTHER
UPPER SYSTEM MOVG ACRS THE NRN MEXICO AND PROVIDE SYNOPTIC SCALE
LIFT MONDAY NGT/TUESDAY. TIMING DIFFERENCES BETWEEN THE SOLNS
SUGGEST PCPN WL END TUESDAY NIGHT OR WEDNESDAY. WL COMPROMISE WITH
PCPN REMAINING OVER THE EXTREME ERN CWA/MSA WEDNESDAY. FURTHER...AS
THE UPPER SYSTEM APPROACHES...BOTH THE GFS AND ECMWF DETERMINISTIC
PROG A TROUGH OF LOW PRESSURE TO DEVELOP OVER THE SWRN GULF MONDAY
NIGHT/TUESDAY AND MAINTAIN AT LEAST A MODERATE NORTHEAST FLOW DRG
THAT TIME. NO PCPN EXPECTED THURSDAY/FRIDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 56 68 59 72 47 / 10 30 40 40 30
VICTORIA 49 66 57 68 42 / 10 40 50 50 20
LAREDO 58 71 58 73 48 / 30 40 50 30 30
ALICE 56 70 58 73 47 / 10 40 50 40 30
ROCKPORT 56 64 60 64 47 / 10 30 40 40 30
COTULLA 52 68 56 70 44 / 30 60 40 30 20
KINGSVILLE 57 70 59 74 48 / 10 30 40 40 30
NAVY CORPUS 56 65 60 65 49 / 10 30 40 40 30
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY FOR WINDS UNTIL 10 PM CST THIS EVENING FOR
THE FOLLOWING ZONES: COASTAL WATERS FROM BAFFIN BAY TO PORT
ARANSAS OUT 20 NM...WATERS FROM BAFFIN BAY TO PORT ARANSAS
FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS TO MATAGORDA
SHIP CHANNEL FROM 20 TO 60 NM.
SMALL CRAFT ADVISORY FOR WINDS UNTIL 8 PM CST THIS EVENING FOR
THE FOLLOWING ZONES: BAYS AND WATERWAYS FROM BAFFIN BAY TO
PORT ARANSAS.
&&
$$
TMT/89...AVIATION
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1146 PM CST WED JAN 28 2015
.AVIATION...
WINDS WERE AROUND 25 TO 40 KNOTS AROUND 1500 FEET AWAY FROM THE
COASTAL COUNTIES. OTHERWISE...THE NAMBUFR AND RAP13 SOUNDINGS SHOW
PATCHY GROUND FOG MAY BECOME MORE WIDESPREAD AFTER ABOUT 10Z. AT
LEAST MVFR AND POSSIBLY IFR/LIFR MAY BE PREVALENT BETWEEN 10Z AND
15Z. THE FORECAST SOUNDINGS ALSO INDICATE THAT VFR MAY NOT DEVELOP
AFTER 17Z. A FRONTAL BOUNDARY WILL THEN MOVE INTO SOUTHEAST TEXAS
TOWARD THE EARLY EVENING.
40
&&
.PREV DISCUSSION... /ISSUED 947 PM CST WED JAN 28 2015/
UPDATE...
WILL ISSUE A DENSE FOG ADVISORY FOR AREAS SOUTHWEST OF HOUSTON.
VISIBILITIES HAVE BEGUN TO DROP AND WINDS HAVE RELAXED A BIT. 43
PREV DISCUSSION... /ISSUED 823 PM CST WED JAN 28 2015/
UPDATE...
SEE EVENING UPDATE.
DISCUSSION...
AT 8 PM...SURFACE HIGH PRESSURE WAS LOCATED OVER THE NORTHERN GULF
COAST WITH A TROUGH LOW PRESSURE EXTENDING FROM EASTERN KANSAS
INTO NORTH CENTRAL TEXAS. THE PRESSURE GRADIENT BETWEEN THESE TWO
FEATURES IS RATHER TIGHT SO NOT EXPECTING WINDS TO FULLY DECOUPLE
OVERNIGHT. SFC TEMPS HAVE FALLEN TO NEAR THE DEW PT OVER THE SW
ZONES AND RAP13 FCST SOUNDINGS SHOW A VERY FAVORABLE PROFILE FOR
FOG DEVELOPMENT TONIGHT. THE HRRR IS HINTING AT FOG WITH
VISIBILITIES DROPPING TO BELOW A 1/2 MILE TONIGHT BUT JUST NOT
CONFIDENT ENOUGH TO GO WITH DENSE FOG AT THIS TIME DUE TO THE
SLIGHTLY STRONGER WINDS. WILL WATCH TRENDS CLOSELY AND IF WINDS
RELAX...A DENSE FOG ADVISORY MAY BE REQUIRED FOR THE SW HALF OF
THE REGION. 43
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 53 72 43 57 45 / 0 10 10 10 20
HOUSTON (IAH) 54 73 47 60 46 / 0 10 10 10 10
GALVESTON (GLS) 56 70 51 57 50 / 0 10 10 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...DENSE FOG ADVISORY UNTIL 9 AM CST THURSDAY FOR THE FOLLOWING
ZONES: BRAZORIA...FORT BEND...GALVESTON...JACKSON...
MATAGORDA...WHARTON.
GM...NONE.
&&
$$
DISCUSSION...43
AVIATION/MARINE...40
YOU CAN SEE AN ILLUSTRATED VERSION OF THIS FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1231 AM CST SAT JAN 31 2015
...UPDATED AVIATION SECTION...
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 144 PM CST FRI JAN 30 2015
MOISTURE AND ISENTROPIC LIFT FROM I300 TO I308 APPEARS TO HAVE A
DECENT HANDLE OF THE LIGHT PRECIPITATION CURRENTLY SPREADING NORTH
ACROSS NORTHEAST NEW MEXICO AND THE PANHANDLE OF TEXAS. BASED ON
15Z AND 18Z VERIFICATION EARLIER TODAY WILL THEREFORE BE USING THE
THE I300 TO I308 LEVEL OVERNIGHT AS GUIDE FOR PRECIPITATION
CHANCES AND TIMING OF THIS PRECIPITATION AS IMPROVING MOISTURE
AND ISENTROPIC LIFT DEVELOPS ACROSS SOUTHWEST KANSAS. AT THIS TIME
BASED ON THE 12Z NAM AND LATEST RAP THE BETTER OPPORTUNITY FOR
WIDESPREAD PRECIPITATION OVER WESTERN KANSAS WILL BE FROM 03Z AND
09Z SATURDAY. AFTER 09Z ISENTROPIC DOWNGLIDE BEGINS TO DEVELOPS
ACROSS FAR WESTERN KANSAS SO THIS PRECIPITATION TO BEGIN TO TAPER
OFF NEAR THE COLORADO BORDER, OR AT LEAST BECOME MORE WIDELY
SCATTERED, EARLY FRIDAY MORNING.
AT THIS TIME MODEL SOUNDINGS ALONG WITH THE TOP DOWN APPROACH FOR
PRECIPITATION TYPE BOTH SUPPORT MAINLY A COLD RAIN EVENT FOR ALL
BUT PORTIONS OF NORTH CENTRAL AND FAR WESTERN KANSAS. IN THE NORTH
CENTRAL AND FAR WESTERN KANSAS THE ATMOSPHERE WILL BECOME COLD
ENOUGH FOR THE RAIN TO MIX WITH, OR BRIEFLY CHANGE OVER TO SNOW
AROUND DAYBREAK SATURDAY. BASED ON THE WARM SURFACE TEMPERATURES
AND RAINFALL OVERNIGHT LITTLE IF ANY SNOW ACCUMULATION IS EXPECTED
SHOULD A BRIEF PERIOD OF SNOW DEVELOPS.
AREAS OF FOG CAN ALSO BE EXPECTED LATE TONIGHT BASED ON THE
MOISTURE PROFILES NEAR THE SURFACE AND SOUTH SOUTHEASTERLY WIND AT
10 TO 15 MPH.
ON THURSDAY SOME BREAKS OF SUN WILL BE POSSIBLE ACROSS PORTIONS OF
WESTERN KANSAS EARLY IN THE DAY GIVEN THE ISENTROPIC DOWNGLIDE
DEVELOPING IN THIS AREA. AS A RESULT HAVE FAVORED THE WARMER
GUIDANCE FOR HIGHS SATURDAY AFTERNOON WEST OF HIGHWAY 283. FURTHER
EAST MOISTURE AND WEAK ISENTROPIC LIFT WILL CONTINUE SO WILL FAVOR
THE COOLER GUIDANCE GIVEN THE EXPECTED CLOUD COVER AND LIGHT
PRECIPITATION. AT THIS TIME HIGHS ARE EXPECTED TO VARY FROM NEAR
40 IN SOUTH CENTRAL KANSAS TO MID 40S IN WEST CENTRAL KANSAS.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 307 PM CST FRI JAN 30 2015
CONFIDENCE REMAINS RELATIVELY HIGH THAT THE SYSTEM WILL BE TOO SLOW
TO TURN COLD ENOUGH TO WARRANT A SIGNIFICANT ACCUMULATION OF SNOW
SATURDAY NIGHT. THE LATEST NAM AND ECMWF RUNS MAINTAIN OUR AREA ON
THE WARM SIDE OF THE SURFACE BOUNDARY UNTIL MID EVENING SATURDAY
WHEN HE FRONT IS ABLE TO BE FORCED THROUGH THE CENTRAL HIGH PLAINS
BY THE EXITING UPPER SYSTEM. EVENT HE IMMEDIATE POST FRONTAL AIR
APPEARS TOO WARM FOR SNOW ACCUMULATION, AND TEMPERATURES MAY NOT
FALL COLD ENOUGH ACROSS A LARGE ENOUGH PORTION OF THE AREA UNTIL
SUNDAY MORNING WHEN THE UPPER STRETCHING AND DEFORMATION HAS
BASICALLY CEASED.
THE COLDEST AIR IN A FEW WEEKS SHOULD THEN BE NOTICED BY SUNDAY
NIGHT AND EARLY MONDAY MORNING, AS STRONG SUBSIDENCE, DRIER AIR AND
GOOD LONGWAVE RADIATIONAL COOLING OF A COLDER DRIER AIRMASS IS
POSSIBLE. THE MOS OUTPUT FROM AT LEAST THE ECMWF AND NAM MODELS ARE
THE COLDEST WITH POTENTIAL FOR EVEN SINGLE DIGITS OVER CENTRAL
KANSAS EARLY MONDAY MORNING. THE CONSENSUS OF RAW MODEL OUTPUT WAS
NOT FAR FROM THESE COLDER SOLUTION AS WELL, WHICH WAS USED AS THE
OFFICIAL FORECAST. A STRONG WARMING TREND ON THE EAST SIDE OF AN
UPPER RIDGE WILL BE NOTICED HEADING INTO MID WEEK, WITH TEMPERATURES
LIKELY BACK INTO THE 60S BEFORE THE NEXT UPPER JET/SHORTWAVE/COLD
FRONT AFFECT THE CENTRAL PLAINS LATE WEDNESDAY AND THURSDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1229 AM CST SAT JAN 31 2015
OCCASIONAL MVFR CONDITIONS WILL BE POSSIBLE OVERNIGHT AS MOSTLY
CLOUDY SKIES AND LIGHT RAIN SHOWERS FALL ACROSS WESTERN KANSAS.
WINDS WILL GENERALLY BE FROM THE SOUTH AROUND 12 KNOTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 44 31 36 13 / 60 60 10 0
GCK 46 31 37 13 / 50 50 0 0
EHA 44 33 40 21 / 50 50 0 0
LBL 44 34 41 17 / 60 60 10 0
HYS 42 26 29 10 / 50 60 0 0
P28 42 34 38 13 / 70 70 10 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BURGERT
LONG TERM...RUSSELL
AVIATION...HOVORKA_42
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1246 AM EST SAT JAN 31 2015
.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN THROUGH SATURDAY. LOW PRESSURE WILL
BRING WINTRY WEATHER SUNDAY INTO MONDAY.
&&
.NEAR TERM /THROUGH TODAY/...
THE FAA TERMINAL DOPPLER RADAR INDICATES ONLY A COUPLE OF
MICROSCALE SNOW BANDS REMAIN...ONE OVER MOSTLY WASHINGTON
COUNTY...AND ANOTHER MUCH WEAKER ONE OVER SOUTHWESTERN ALLEGHENY
COUNTY. MODEL SOUNDINGS FROM BOTH THE RAP AND HRRR SHOW A SCENARIO
WHEREBY INVERSION HEIGHTS ARE FALLING SIMULTANEOUSLY WITH BOUNDARY
LAYER MOISTURE DEPTH DECREASING AS WELL. LIKEWISE...UPSTREAM
ACTIVITY OFF OF LAKE HURON IS QUICKLY FALLING APART...AND THE
TREND TOWARD ANY ADDITIONAL INPUT FROM THE SLIVER OF LAKE ERIE
THAT IS OPEN WILL NOT BE PARTICULARLY HELPFUL TO REGENERATION OF
ANY OF THE BANDS. THAT SAID...ACTIVITY WILL LIKELY TAKE A FEW
HOURS TO WANE WITH THE UPSLOPE AREAS TAKING THE LONGEST TO FULLY
HALT THEIR SNOW SHOWER AND FLURRY ACTION.
NORTHWESTERLY FLOW CONTINUES THROUGH MUCH OF THE EVENING HOURS
BEFORE SLOWLY TURNING WEST OVERNIGHT AS A SURFACE HIGH BUILDS
GENERALLY JUST TO THE SOUTH OF THE REGION. WITH AT THE VERY LEAST
PARTIAL CLEARING...IF NOT FULL CLEARING AT TIMES...TEMPERATURES
SHOULD DROP RAPIDLY WITH NEW SNOW COVER. THIS COMBINED WITH
DECREASING YET STILL BRISK SURFACE FLOW WILL ALLOW FOR WIND CHILL
ADVISORY CRITERIA WIND CHILL INDEX VALUES BY MORNING OVER THE HIGHER
TERRAIN AND NORTHEASTERN CWA. THIS IS IN LINE WITH CURRENT
HEADLINES...AND NO ADDITIONAL EXPANSION OF THESE HEADLINES ARE
ANTICIPATED AT THIS TIME. HOWEVER...WITH RAPID CLEARING AND NEW
SNOW ON THE GROUND...ALL AREAS WILL LIKELY BE VERY COLD BY
MORNING...WITH MANY PORTIONS OF THE CWA CHALLENGING OR EVEN
DROPPING BELOW ZERO BY THAT JUNCTURE.
SOME WARMER AIR DOES START TO FLOW NORTHWARD ON SATURDAY AS THE
SURFACE HIGH AXIS MOVES TO THE EAST OF THE AREA AND SOUTHWESTERLY
FLOW PREVAILS FOR A TIME. EXPECTATIONS SHOULD BE
MUTED...THOUGH...AS SUCH A COLD START AND WEAK VERTICAL MIXING
WILL LIKELY KEEP MOST OF THE AREA IN THE 20S. FRIES
&&
.SHORT TERM /TONIGHT THROUGH MONDAY/...
HIGH PRES SHOULD CONT DRY WEA INTO SAT EVE. A DIGGING UPR TROF IS
PROGGED TO ADVN OUT OF THE PLAINS AND TRACK ACRS THE GT LKS AND
OH VLY RGN SUN INTO MON. ASSOCIATED SFC LOW PRES IS PROGGED TO
DEEPEN AS IT MOVES ACRS THE TN AND OH VLY RGNS ALSO. THIS WL
SPREAD SNW INTO THE RGN LT SAT NGT THRU MON MRNG WITH DEEP
AVAILABLE MSTR AND OMEGA.
WITH A CLOSED 850MB LOW...A MORE PROLONGED PCPN EVENT IS EXPD AS
OPPOSED TO THE OPEN SYSTEM EARLIER IN THE WK. WITH ENOUGH
POTENTIAL FOR HEAVY SNW OR A SNW/ICE MIX...ISSUED A WINTER STORM
WATCH FOR MUCH OF THE AREA. LEFT AREAS GENLY S OF I 70 OUT OF THE
WATCH...EXCEPT FOR THE WV/MD RIDGES...AS ENOUGH WRM AIR IS EXPD TO
WRAP IN AHD OF THE LOW TO ALLOW FOR A RAIN/SNW MIX OR EVEN A PD OF
ALL RAIN. AREAS BETWEEN I 70- AND I 80 COULD SEE ENOUGH WRM AIR
ALOFT FOR FRZG RAIN TO MIX IN AT TIMES AS WELL. GENLY FOLLOWED A
SREF/GFS/ECMWF MDL BLEND TO WORK OUT THE DETAILS...AND USED
CRITICAL THICKNESSES/MDL SOUNDING PROFILES FOR PCPN TYPE. BEST
POTENTIAL FOR GREATER THAN 6 INCHES OF SNW EXISTS N OF PIT BASED
ON LATEST MDL GUIDANCE...THOUGH THIS WL BE REFINED OVR THE NXT
COUPLE OF DAYS.
SNW SHOULD CONT MON UNTIL THE UPR TROF AXIS SHIFTS E IN THE AFTN.
NUDGED TEMPS TO THE LATEST COLDER THAN SEASONAL AVG SREF GUIDANCE.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
A COLD...WINTER PATTERN WILL CONTINUE FOR THE REST OF THE LONG
TERM. THE NEXT BEST CHANCE FOR SNOW SHOWERS WILL ARRIVE LATE IN
THE PERIOD.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
MVFR STRATOCU CONTINUE TO ERODE SLOWLY FROM THE WEST...WITH ONLY A
FEW SHSN/FLURRIES REMAINING...AS LAKE HURON CONNECTION GETS CUT
OFF WITH WINDS BACKING TO WEST. ONCE THESE BREAK UP...VFR WITH
ONLY SCT AC EXPECTED OVERNIGHT THROUGH SUNRISE SATURDAY. SOME
BORDERLINE MVFR CIGS SATURDAY AFTERNOON WITH WARM FRONTAL ACTION.
VFR THEN EXPECTED TO RETURN FOR THE EVENING...BUT MID/HI CLOUDS
WILL BE ON THE INCREASE. HINT AT FIRST -SN AT PIT AROUND 09Z
SUNDAY WITH NEXT STORM SYSTEM. CL
.OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/...
WIDESPREAD RESTRICTIONS CAN BE EXPECTED SUNDAY AND MONDAY AS A LOW
PRESSURE SYSTEM CROSSES THE REGION.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WINTER STORM WATCH FROM LATE TONIGHT THROUGH MONDAY MORNING
FOR MDZ001.
WIND CHILL ADVISORY UNTIL 10 AM EST THIS MORNING FOR MDZ001.
OH...WINTER STORM WATCH FROM LATE TONIGHT THROUGH MONDAY MORNING
FOR OHZ039>041-048>050-057>059.
PA...WINTER STORM WATCH FROM LATE TONIGHT THROUGH MONDAY MORNING
FOR PAZ007>009-013>016-020>023-029-073>076.
WIND CHILL ADVISORY UNTIL 10 AM EST THIS MORNING FOR PAZ008-
009-015-016-023-074-076.
WV...WINTER STORM WATCH FROM LATE TONIGHT THROUGH MONDAY MORNING
FOR WVZ001>003-023-041.
WIND CHILL ADVISORY UNTIL 10 AM EST THIS MORNING FOR WVZ023-
041.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1147 PM EST FRI JAN 30 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 406 PM EST FRI JAN 30 2015
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM
HUDSON BAY INTO THE NE CONUS RESULTING IN NW FLOW THROUGH THE NRN
GREAT LAKES. AN UPSTREAM SHORTWAVE TROUGH WAS LOCATED OVER SRN
MANITOBA. THE SHRTWV AND ASSOCIATED WAA PATTERN SUPPORTED SOME LIGHT
SNOW FROM FAR NRN MN INTO NW ONTARIO WITH VSBY INTO THE 1-3SM RANGE.
AT THE SFC...A RIDGE EXTENDED FROM THE MID MS VALLEY INTO THE WRN
GREAT LAKES. BACKING WINDS TO SW OVER WRN LAKE SUPERIOR AND W OVER
THE ERN LAKE HAVE PUSHED THE LES BANDS OFFSHORE EXCEPT FOR SOME
LINGERING FLURRIES NEAR GRAND MARAIS.
TONIGHT...EXPECT MID/HIGH CLOUDS TO THICKEN INTO THIS EVENING AS THE
AS THE SHRTWV APPROACHES. UPSTREAM TRENDS AND MODELS FCST 285K-290K
ISENTROPIC LIFT...SUGGESTS THAT THE AREA OF LIGHT SNOW WILL SPREAD
THROUGH UPPER MICHIGAN BTWN 03Z-09Z. WITH LITTLE MOISTURE AVAILABLE
AND DRY LOW LEVELS DELAYING THE ONSET OF THE PCPN...QPF OF 0.05 OR
LOWER WITH SLR VALUES NEAR 20/1 WOULD ONLY RESULT IN SNOW AMOUNTS OF
AN INCH OR LESS. HOWEVER...AS LOW LEVEL CONV INCREASES ALONG THE SFC
FRONT/TROUGH AND 850 MB TEMPS DROP TO AROUND -12C...THERE MAY BE A
BRIEF PERIOD OF LAKE ENHANCED SNOW INTO NW UPPER MI THAT MAY BRING
TOTALS INTO THE 1 TO 2 INCH RANGE.
SAT...THE AREA OF LOW LEVEL CONV WITH THE FRONT WILL SLIDE THROUGH
THE REST OF THE NRN CWA WITH THE POTENTIAL FOR A NARROW BAND OF
MODERATE SNOW. ALTHOUGH 850 MB TEMPS DROP TO NEAR -20C BY 00Z
SUN...A QUICK TRANSITION TO A MORE DIFFLUENT/ANTICYCLONIC LOW-LVL
NORTHERLY FLOW AND FALLING INVERSIONS AT OR BELOW 4KFT WILL LIMIT
LES INTENSITY THE REST OF THE DAY. SNOW ACCUMULATIONS OF ONLY AROUND
AN INCH ARE EXPECTED. AFTER MIDDAY HIGHS RANGING FROM THE TEENS NW
TO MID TO UPPER 20S SCNTRL...TEMPS WILL DURING THE AFTERNOON AS
BRISK N TO NW WINDS USHER ARCTIC AIR MASS INTO THE AREA. GUSTY WINDS
WILL ALSO CREATE BLSN IN OPEN AREAS NEAR LAKE SUPERIOR.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 424 PM EST FRI JAN 30 2015
COLD WEATHER PATTERN IN STORE FOR MUCH OF EXTENDED. TEMPS WILL BE
MUCH BLO NORMAL...ESPECIALLY FOR DAYTIME HIGHS. NORMAL HIGHS FOR
FIRST PORTION OF FEBRUARY ARE IN THE LOWER TO MIDDLE 20S...AND THERE
WILL BE A FEW DAYS NEXT WEEK WHERE HIGHS STAY BLO 10 ABOVE. TROUGHING
ALOFT EXPANDS FM NORTHERN CANADA OVER GREAT LAKES AND MOST OF THE
EASTERN CONUS AS RIDGING TEMPORARILY BUILDS OVER THE WEST COAST. LEAD
SHOT OF ARCTIC AIR DROPS OVER GREAT LAKES SECOND HALF OF THE WEEKEND
WITH H85/5KFT AGL TEMPS BLO -20C/-3F. ANOTHER STRONGER PUSH OF COLDER
AIR IS DUE IN THE MIDDLE OF THE WEEK AS H85 TEMPS DROP TO AT LEAST
-25C/-13F. COULD BE A WIDESPREAD SNOW JUST AHEAD OF THAT REINFORCING
COLD FRONT TUESDAY NIGHT INTO WEDNESDAY. SINCE THE RIDGING OVER THE
WEST COAST IS NOT THAT SHARP...WESTERN RIDGE AND EASTERN TROUGH
PATTERN BREAKS DOWN BY NEXT WEEKEND WITH TEMPS MODERATING BACK TOWARD
NORMAL...POSSIBLY ABOVE...BY NEXT WEEKEND.
COLD FRONT MOVES EAST OF THE AREA ON SATURDAY NIGHT. ARCTIC HIGH
PRESSURE BUILDS FM THE CANADIAN PRAIRIES TO THE NORTHERN PLAINS.
RIDGING EXTENDS NORTH OF LK SUPERIOR WITH CONFLUENT FLOW ALOFT.
SOUNDINGS INDICATE INVERSIONS 4 TO POSSIBLY 6 KFT WITH DELTA T/S
INCREASING FM AROUND 18C SATURDAY EVENING TO 25C BY SUNDAY MORNING.
MAJORITY OF DGZ NOT WITHIN LAKE CONVECTIVE LAYER...SO SNOWFLAKE SIZE
AND THUS SLR/AMOUNTS WILL BE HELD DOWN TO AROUND 20:1 OR EVEN LOWER.
LOW-LEVEL WINDS START OUT NNW-N ON SATURDAY EVENING AND TURN TO NNE
BY SUNDAY AS RIDGING EXPANDS NORTH OF LK SUPERIOR. SETUP FAVORS LES
WITH MAINLY LIGHT ACCUMS FOR FAR WEST CWA AND OVER THE NCNTRL CWA.
SOUNDINGS INDICATE POSSIBLE WEAK LAKE ENHANCED SETUP AS SWATH OF H7-
H5 MOISTURE MOVES ACROSS SATURDAY EVENING INTO SUNDAY MORNING.
EXTENT OF DRYING BTWN THE MID-LEVEL MOISTURE AND LAKE CONVECTIVE
LAYER MAY BE TOO MUCH TO OVERCOME THOUGH AS LIFT ALOFT IS WEAK. LOW-
LEVEL CONVERGENCE VCNTY OF NORTH CENTRAL UPR MICHIGAN MAY MAKE UP
FOR OVERALL MARGINAL SETUP FOR LES...BUT EVEN SO...DO NOT EXPECT
MORE THAN A FEW INCHES OF SNOW SATURDAY NIGHT INTO SUNDAY FOR
FAVORED AREAS. WINDS ARE NOT VERY STRONG...SO SNOW SHOWERS MAY TRY
TO STAY CONFINED TOWARD THE SHORE INSTEAD OF SETTING UP OVER THE
HIGHER TERRAIN.
DESPITE THE ARRIVAL OF THE ARCTIC AIR...WINDS SHOULD NOT BE TOO
STRONG...LIMITING THE OVERALL IMPACT. TEMPS SATURDAY NIGHT SHOULD
FALL WELL BLO ZERO OVER THE EAST WITH DRAINAGE FLOW OFF ONTARIO.
OTHERWISE...NE FLOW AND WEALTH OF STRATUS OFF LK SUPERIOR BENEATH A
SUBSIDENCE INVERSION WILL RESTRICT TEMPS FM FALLING BLO ZERO.
STRATUS SHOULD STAY IN PLACE FOR MUCH OF SUNDAY...EXCEPT OVER THE
FAR EAST. HIGHS ON SUNDAY WILL STAY IN THE SINGLE DIGITS AND MAY
JUST STRUGGLE ABOVE ZERO IN THE FAR EAST CWA. ARRIVAL OF ANOTHER
SHORTWAVE FM THE NORTHWEST ACROSS THE PLAINS WILL BRING A SWATH OF
SNOW TO AS CLOSE AS NORTHERN WI LATE SATURDAY NIGHT. THAT SYSTEM
PHASES WITH ANOTHER MOVING OUT OF THE REMNANT OF CURRENT SOUTHWEST
CONUS LOW TO PROVIDE WIDESPREAD SNOW ON SUNDAY ALONG DEVELOPING SFC
LOW OVER MAINLY SOUTHERN PORTIONS OF WISCONSIN AND MICHIGAN. LOOKS
LIKE UPR MICHIGAN WILL MISS THIS STORM SYSTEM. EXPECT LINGERING
WEAKENING LES FOR SNOW BELTS TO EAST OF MARQUETTE AND POSSIBLY OVER
THE NORTHWEST CWA. LES WILL CONTINUE TO DRIFT MAINLY OFFSHORE ON
SUNDAY NIGHT AS WINDS IN BLYR SLOWLY BACK TO THE WEST ON EDGE OF
HIGH PRESSURE SINKING OVER THE MIDDLE MISSISSIPPI RIVER VALLEY.
CHILLY TEMPS FOR SUNDAY NIGHT WELL BLO ZERO...ESPECIALLY IN THE WEST
INTERIOR AND ALSO EAST CWA WITH CONTINUATION OF LOW-LEVEL FLOW OFF
ONTARIO. SINCE WINDS ARE LIGHT AND CALM...NO WIND CHILL ISSUES ARE
EXPECTED.
LES DRIFTS FARTHER EAST TO SNOW BELTS EAST OF MUNISING AND LIKELY
INCREASES ON THE KEWEENAW AS WINDS BECOME MORE CONVERGENT FM THE
WEST. SETUP THEN MAY BECOME FAVORABLE FOR MODERATE TO POSSIBLY HEAVY
LAKE ENHANCED SNOW FOR NORTHERN KEWEENAW LATE MONDAY INTO TUESDAY
MORNING AS WSW FLOW RESULTS IN STRONG CONVERGENCE BAND TO FORM WHILE
SHORTWAVE WITH ADDITIONAL MID-LEVEL LIFT AND MOISTURE SLIDES ACROSS.
SOUNDINGS INDCIATE THAT INVERSIONS REACH MORE TOWARD 8KFT WITH
INVERSION TOP TEMPS NEARING -24C. POTENTIAL FOR HEAVY SNOW WITH
RATES OVER 1 INCH PER HOUR WILL GREATLY DEPEND ON WHERE SHARPEST
CONVERGENCE ALLIGNS. TOUGH TO TELL THAT AT THIS POINT WHERE THAT
OCCURS...BUT WORTH AN HWO MENTION AS THIS TYPE OF LES PATTERN CAN
RESULT IN A LOT OF SNOW IN JUST A FEW HOURS.
ON INTO TUESDAY...LOW PRESSURE SYSTEM WILL BE ADVANCING ACROSS THE
NORTHERN PLAINS. AREA OF H7-H5 Q-VECTOR CONVERGENCE TO THE NORTH AND
EAST OF THE LOW AND AREA OF DIVERGENCE IN RIGHT ENTRANCE REGION OF
JET STREAK SLIDING OVER THE UPPER GREAT LAKES SHOULD SPREAD AN AREA
OF LGT SNOW WEST TO EAST ACROSS THE WESTERN GREAT LAKES. WENT WITH
LOW POPS AWAY FM LAKE EFFECT AREAS...ESPECIALLY AS THE ECMWF KEEPS
MOST WIDESRPEAD QPF SOUTH OF UPR MICHIGAN. LOW PRESSURE SYSTEM
SHOULD BE JUST EAST OF UPR MICHIGAN WEDNESDAY MORNING WITH STRONGER
COLD FRONT POISED TO SWEEP ACROSS. EXPECT NW FLOW LAKE EFFECT TO
RAMP UP WEDENSDAY AFTN AS NEW SURGE OF COLD AIR RETURN TO THE AREA.
ECMWF/GFS VARYING ON HOW COLD IT GETS AT H85. BLEND OF 12Z RUNS
SUGGEST H85 TEMPS END UP AROUND -27C/-17F WHICH WITH LAKE TEMPS IN
ICE FREE AREAS AROUND 2C/35F YIELDS PLENTY OF OVER-WATER
INSTABILITY. ALSO...COMPARED TO THE RECENT LAKE EFFECT EVENTS...THE
FORECAST SOUNDINGS INDICATE INVERSIONS MAY CLIMB TOWARD 8KFT. DUE TO
THE COLD AIR...SLR/S WILL BE LOWER...BUT WHATEVER LES OCCURS WILL BE
EFFICIENT AT REDUCING VSBY. SEEMS THAT SOME HAZARDS FOR THE SNOW AND
BLSN MAY BE NEEDED AND LOW VSBY AFFECT WOULD ONLY BE ENHANCED DUE TO
THE ICE COVER NEAR THE SHORELINE OF LK SUPERIOR. WILL MENTION THIS
IN THE HWO.
WILL BE AROUND WIND CHILL ADVISORY CRITERIA FOR AT LEAST WESTERN CWA
LATE WEDNESDAY NIGHT INTO THURSDAY MORNING AS TEMPS DROP TOWARD 10
BELOW AND WINDS ARE AT LEAST 5-10 MPH FM THE NW. ELSEWHERE...NW FLOW
OFF LK SUPERIOR WILL MODERATE TEMPS AND KEEP WIND CHILLS ABOVE 20
BELOW. LES DIMINISHES AND EVENTUALLY ENDS BY NEXT FRIDAY AS WINDS
BACK SW WITH HIGH PRESSURE DROPPING ACROSS THE CENTRAL PLAINS. COLD
FOR ALL ON FRIDAY MORNING WITH MOST AREAS BLO ZERO...BUT WINDS SHOULD
BE LIGHT ENOUGH TO RESTRICT WIND CHILL ISSUES AT THAT TIME.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1146 PM EST FRI JAN 30 2015
A TROUGH OVER NW MN WILL CROSS CENTRAL LAKE SUPERIOR BY 12Z. LOOK
FOR -SN TO PICK UP IN INTENSITY ALONG AND BEHIND THE FRONT AND
CONDITIONS AT SAW AND IWD WILL BE MVFR AND STAY THERE THROUGH THE
REST OF THE FORECAST PERIOD. LES AND GUSTY WINDS PRODUCING BLSN AND
LOWER VSBY INTO IFR CATEGORY IS EXPECTED AT CMX OVERNIGHT BEFORE
GOING TO MVFR BY AFTERNOON.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 424 PM EST FRI JAN 30 2015
BRIEF LULL IN STRONGER WINDS OVER LK SUPERIOR ATTM AS HIGH PRESSURE
DRIFTS ACROSS. STRONG COLD FRONT CROSSING ON SATURDAY WILL BRING IN
ANOTHER SURGE OF STRONG WINDS...POSSIBLY REACHING 35 KT GALES
SATURDAY AFTN INTO SATURDAY EVENING. LEFT THE GALE WATCH UP AS IT IS
ONLY A MARGINAL SETUP FOR GALES. MID SHIFT CAN MAKE THE FINAL CALL.
DID PUT UP HEAVY FREEZING SPRAY WARNING AS THAT IS MORE CERTAIN.
WINDS BECOME LIGHT BY SUNDAY AS HIGH PRESSURE DRIFTS ACROSS. WINDS
INCREASE FM THE WSW ON MONDAY NIGHT AHEAD OF ANOTHER LOW PRESSURE AND
COLD FRONT THAT SWEEP OVER THE AREA ON TUESDAY NIGHT AND WEDNESDAY.
BEHIND THAT FRONT...ANOTHER PERIOD OF GALES AND HEAVY FREEZING SPRAY
IS EXPECTED INTO THURSDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM SATURDAY AFTERNOON THROUGH SATURDAY EVENING FOR
LSZ264-266-267.
HEAVY FREEZING SPRAY WARNING FROM NOON SATURDAY TO 5 AM EST
SUNDAY FOR LSZ264-266-267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...07
MARINE...JLA
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1121 PM CST FRI JAN 30 2015
.UPDATE...
ISSUED AT 907 PM CST FRI JAN 30 2015
THE OVERALL TREND OF THE FORECAST REMAINS ON TRACK WITH
PRECIPITATION SPREADING NORTHEAST OUT OF CENTRAL KANSAS...THEN
DEVELOPING NORTH TOWARD THE NE/SD BORDER REGION. BELIEVE PRECIP
TYPE WILL BE THE ISSUE AND POSSIBLE CHANGEOVER TIME WHICH
COMPLICATES THE FORECAST.
00Z NAM REMAINS VERY AGGRESSIVE WITH PRECIP DEVELOPMENT WITH 0.88
INCHES OF QPF AT KOMA THROUGH 48 HOURS. BUFKIT SOUNDINGS SUGGEST
A FAIRLY RAPID CHANGEOVER TO SNOW WITH STRONG DYNAMICAL COOLING
TAKING PLACE ACROSS THE REGION...WITH ABOUT 4 G/KG OF SPECIFIC
HUMIDITY NOTED ON THE 290K ISENTROPIC SURFACE SO THERE IS PLENTY
OF MOISTURE TO WORK WITH. INDEED...00Z SUBJECTIVE UPPER AIR
ANALYSIS INDICATES FAIRLY DEEP AND SATURATED MOISTURE STREAMING
NORTHWARD WITH ABOUT 0.6 TO 0.8 INCHES OF PW...WHICH IS IN THE
97.5-99 NAEFS PW CLIMATOLOGICAL PERCENTILE ALONG AND SOUTH OF I80.
AN INITIAL CONCERN IS THAT PRECIP COULD POTENTIALLY CHANGE OVER
TO ALL SNOW EARLIER THAN FORECAST RESULTING IN HIGHER SNOWFALL
TOTALS. THE SECOND CONCERN IS THE RATHER DEEP SATURATION THAT IS
PROGGED TO OVERSPREAD THE REGION RESULTING IN HIGHER QPF THAN
FORECAST. MODEL SUITES ARE ALL GENERATING 0.7 TO 0.9 INCHES OF
QPF AND OUR FORECAST REMAINS BELOW THAT BY ABOUT ONE QUARTER
INCH. ONE MITIGATING FACTOR IS THE SREF PROBABILITY OF
ACCUMULATION ON ROADS PRODUCT REMAINS LOW MUCH OF THE DAY
SATURDAY...HOLDING OFF UNTIL WELL AFTER DARK BEFORE ROADWAYS
BECOME SIGNIFICANTLY IMPACTED. THAT DOESN`T MEAN WOULD WOULDN`T
STILL BE ABLE TO ACCUMULATE SNOWFALL ON GRASSY SURFACES THOUGH.
WILL WAIT FOR GFS...SREF...HIRES AND ECMWF MODELS BEFORE MAKING
MAJOR CHANGES...BUT INITIAL THOUGHTS ARE THAT QPF/SNOW AMOUNTS
MAY NEED TO BE RAISED. EARLY IN THE EVENT...WINDS WILL ALSO REMAIN
GENERALLY LIGHT LESS THAN 10 MPH WHICH WILL HELP QUITE A BIT.
CURRENT STORM TOTAL SNOWFALL FORECAST RANGES FROM 1 TO 4 INCHES
ACROSS THE REGION...BUT AGAIN...WILL WAIT FOR COMPLETE MODEL
SUITES TO MAKE ANY UPWARD ADJUSTMENTS.
&&
.SHORT TERM...(TONIGHT THROUGH MONDAY)
ISSUED AT 310 PM CST FRI JAN 30 2015
PCPN TYPE AND PCPN AMOUNTS WILL BE THE MAIN CONCERN IN THIS PERIOD...
ESPECIALLY FROM LATE TONIGHT INTO SATURDAY EVENING. PCPN SHOULD TURN
TO MOSTLY SNOW BY LATE SATURDAY NIGHT ALL AREAS.
WATER VAPOR LOOP AND LATEST RAP MODEL INITIALIZATIONS SHOWED A
CLOSED LOW OVER THE CALIFORNIA/ARIZONA BORDER REGION EARLY THIS
AFTN. THIS WILL DROP SOUTHWARD INTO MEXICO THROUGH SUNDAY. SOME
SHORTWAVE ENERGY WILL MOVE NORTHEAST OUT OF THIS TROUGH THOUGH AND
MOVE UP INTO THE CENTRAL PLAINS LATER TONIGHT AND SATURDAY. SURFACE
ANALYSIS EARLY THIS AFTERNOON SHOWED MODEST SOUTH/SOUTHWEST WINDS
SPREADING ACROSS OUR AREA. CLOUDS WILL THICKEN AND LOWER...WITH
LIGHT PCPN PROBABLY MOVING INTO OUR SOUTHERN COUNTIES BEFORE 12Z.
HAVE LOWS FORECAST IN THE UPPER 20S NORTH AND LOWER 30S SOUTH. THE
PCPN TYPE MAY BE A MIX LATER TONIGHT INTO SATURDAY.
DID MAKE SOME MODIFICATIONS TO SNOW AMOUNTS...MAINLY FOR SATURDAY
NIGHT INTO SUNDAY MORNING. ON SATURDAY...IT APPEARS THAT IF WE GET
ANY ACCUMULATIONS...THEY WOULD BE LIGHT AND MAINLY ON GRASSY AREAS
FOR OUR SOUTHERN ZONES. FARTHER NORTH...PCPN CHANCES WILL BE
INCREASING IN THE AFTERNOON BUT AMOUNTS WOULD BE LIGHTER. THE NAM
FORECAST SOUNDINGS STILL APPEARED TOO COLD...AND WENT CLOSER TO A
BLEND OF SOME OF THE OTHER MODELS...ESPECIALLY THE SREF. NORTH
WINDS WILL SPREAD ACROSS THE AREA SATURDAY NIGHT...AND AS THE
COLUMN COOLS...PCPN WILL CHANGE TO MOSTLY SNOW AND WILL START TO
ACCUMULATE. A SEPARATE SYSTEM WILL DROP QUICKLY SOUTHEAST IN THE
NORTHWEST FLOW SATURDAY NIGHT...PROVIDING GOOD LIFT IN A FAVORABLE
ENVIRONMENT FOR SNOW FROM THE NORTHERN PARTS OF NORTHEAST NEBRASKA
INTO WEST CENTRAL IOWA. INCREASED SNOW AMOUNTS FOR AREAS ALONG AND
NORTH OF HIGHWAY 20. IT APPEARS ANOTHER LOBE OF LIFT WILL DROP
DOWN OVER PARTS OF THE AREA SUNDAY AFTERNOON...SO KEPT SOME
MENTION OF LIGHT SNOW GOING UNTIL SUNDAY NIGHT. SUNDAY NIGHT IS
EXPECTED TO BE COLD WITH DECREASING CLOUDS AND DECREASING WINDS.
LOWS SHOULD DROP TO THE SINGLE DIGITS AND WE MAY SEE SOME BELOW
ZERO NUMBERS FROM HARTINGTON AND WAYNE TOWARD TEKAMAH AND HARLAN.
FAST NORTHWEST FLOW IN THE MID LEVELS WILL BE IN PLACE FOR MONDAY
AND IT DOES APPEAR THAT A SHORTWAVE TROUGH COULD MOVE THROUGH OUR
AREA. MODELS...ESPECIALLY THE 12Z GFS...BRING SOME LIGHT SNOW IN
FOR MONDAY AFTERNOON. COULD NOT ARGUE WITH THAT TOO MUCH SO WENT
WITH A SLIGHT CHANCE OF LIGHT SNOW FOR NOW AND WILL FINE TUNE THAT
LATER. MEASURABLE LIGHT AMOUNTS SEEM POSSIBLE...ESPECIALLY IN
WESTERN IOWA MONDAY. HIGHS MONDAY WILL BE MOSTLY 20S.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 310 PM CST FRI JAN 30 2015
SOME MILDER AIR WILL SPREAD IN BRIEFLY FOR TUESDAY...WITH HIGHS
REACHING THE UPPER 30S AND LOWER 40S. DID NOT WANT TO GET TOO
OPTIMISTIC AT THIS POINT FOR HIGHS. ANOTHER SURGE OF COLDER AIR
WILL DROP DOWN INTO THE AREA BY TUESDAY NIGHT. SOME LIGHT SNOW
SEEMS POSSIBLE BASED ON THE PATTERN...PLUS BOTH THE 12Z GFS AND
ECMWF SHOW A BIT OF SNOW.
TEMPERATURES WEDNESDAY AND THURSDAY WILL BE BELOW NORMAL...THEN
CLOSER TO NORMAL BY FRIDAY AS SOUTH OR SOUTHWEST WINDS INCREASE.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1119 PM CST FRI JAN 30 2015
VFR INITIALLY. RAIN AND MVFR CEILINGS DEVELOP AT KLNK BY 10-14Z...KOMA
14-18Z AND KOFK 15-19Z. SHOULD START TO SEE SNOW MIX WITH THE RAIN
BY 21-00Z...CHANGING OVER TO ALL SNOW. WINDS SOUTHERLY INITIALLY...THEN
BACKING BECOMING SOUTHEAST...EAST...AND EVENTUALLY NORTHEAST AND
SUBSTANTIALLY INCREASING AT KOFK TOWARD THE END OF THE PERIOD...AND
AT KLNK/KOMA JUST BEYOND THE END OF THE TAF PERIOD.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
UPDATE...DEWALD
SHORT TERM...KERN/MILLER
LONG TERM...MILLER
AVIATION...DEWALD
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
251 AM EST SAT JAN 31 2015
.SYNOPSIS...
VERY COLD AIR WILL CONTINUE TO POUR INTO THE REGION TONIGHT...WITH
LAKE-EFFECT SNOW PERSISTING DOWNWIND FROM THE FINGER LAKES...AND
BITTERLY COLD WIND CHILLS AREA-WIDE. COLD TEMPERATURES WILL LAST
THROUGH THE UPCOMING WEEKEND...WITH ONLY A FEW FLURRIES FORESEEN
FROM SATURDAY INTO EARLY SUNDAY. AN APPROACHING WINTER STORM COULD
BEGIN TO IMPACT THE AREA BY LATE SUNDAY AFTERNOON OR SUNDAY
EVENING...WITH ACCUMULATING SNOW POSSIBLE.
&&
.NEAR TERM /THROUGH TODAY/...
945 PM UPDATE...
LAKE EFFECT SNOW CONTINUES DOWNWIND OF THE FINGER LAKES. RADAR
INTENSITY DOES NOT LOOK THAT STRONG BUT WITH SURFACE TEMPS THIS
COLD, FLUFF FACTOR IS PROBABLY IN FULL FORCE. ADVISORY THROUGH 1
AM LOOKS GOOD WITH ANOTHER INCH OR TWO POSSIBLE IN THE MOST
PERSISTENT BANDS. WIND CHILL VALUES ARE ALREADY IN THE -5 TO -10
RANGE AND EXPECTED TO DROP FURTHER OVERNIGHT, SO THE WIND CHILL
ADVISORY LOOKS GOOD. A QUICK MENTION OF THE POTENTIAL SNOW FOR
SUNDAY NIGHT INTO MONDAY. WE PUT A GRAPHIC ON SOCIAL MEDIA
(TWITTER/FACEBOOK) TO SHOW THE HIGHEST THREAT FOR SNOW AT THIS
POINT. PREVIOUS AFD IS BELOW.
145 PM UPDATE... ONLY MINOR TWEAKS MADE TO THE GRIDS THIS PD.
AREA-WIDE WIND CHILL ADVSY STILL LOOKS ON TRACK FOR THE OVERNIGHT
HRS...AS VERY STG 925-850 MB CAA THROUGH THIS EVE...SHOULD SEND
AIR TEMPS INTO THE SINGLE DIGITS ABV OR BLO ZERO TNT...WITH THE
PRES GRADIENT REMAINING RELATIVELY TIGHT THIS EVE...AND ONLY
SLOWLY RELAXING LATE. MOST AREAS SHOULD SEE APPARENT TEMPS IN THE
-10 TO -20 RANGE...WITH LOCALLY COLDER VALUES IN OUR FAR NRN AND
ERN ZNS.
AS FAR AS THE LES ADVSY GOES...NO CHGS ATTM. ALTHOUGH BLYR INSTAB
(TERRESTRIAL CAPE VALUES OF 15-30 J/KG) TEMPORARILY RESULTED IN A
MORE CELLULAR APPEARANCE TO THE SNOW SHWRS EARLIER THIS AFTN
LOW-LVL STABILIZATION AND INCRG SHEAR SHOULD RESULT IN THE RE-
EMERGENCE OF WELL DEFINED BANDS BY 21Z OR SO. IN FACT...EVIDENCE
OF SUCH IS ALREADY SEEN ON KBGM RADAR IMAGERY ATTM. MOST HI-RES
MODEL GUIDANCE HINTS THAT MULTI-BANDS/FINGER LKS BANDS WILL REMAIN
AT PLAY TIL AT LEAST 06-12Z SAT. OVERALL...INTENSITY SHOULD WANE
AFTER 06Z...AS MODEL SNDGS SHOW THE CAPPING INVERSION LWRG TO AOB
875-900 MB. WE`LL STICK WITH OUR 3-6" TOTALS FOR NOW...ALTHOUGH
WUDN`T BE SURPRISED TO SEE LOCALLY HIER AMTS...SPCLY IN SERN
TOMPKINS AND/OR NRN TIOGA.
OUTSIDE OF MULTI-BAND AREAS...EITHER WIDELY SCTD -SHSN/FLRYS...OR
JUST DRY WX...IS FORESEEN.
PREV DISC... 10 AM UPDATE... WE`VE ISSUED A LES ADVSY FOR
TOMPKINS...TIOGA...BROOME...AND SUSQ CNTYS...AS CONFIDENCE HAS
BECOME FAIRLY HIGH IN THE MAINTENANCE OF A WELL DVLPD FINGER LKS
BAND...THROUGH AT LEAST 00-03Z THIS EVE. OUR FIRST STAB AT SNOW
TOTALS IS 3-6"...BUT LOCALLY HIER AMTS ARE CERTAINLY PSBL.
NO OTHER SIG CHGS ATTM.
EARLIER DISC... 830 AM UPDATE... SN/+SN IS BEING OBSERVED ATTM
WITHIN A SW-NE ORIENTED BAND ACRS NE PA AND PTNS OF THE WRN
CATSKILLS. THIS FEATURE IS ON THE NWRN/DEFORMATION SIDE OF A S/WV
LIFTING THROUGH THE RGN THIS MRNG. POP/WX/SNOWFALL GRIDS WERE
UPDATED TO REFLECT SUCH DVLPMTS. WE`VE ADDED A CORRIDOR OF 2-3"
ADDNL SNOWFALL WITHIN THE AFOREMENTIONED BAND AREA THROUGH
15-16Z. A SHORT-TERM SPS WAS ALSO ISSUED.
OTHWS...THE FCST IS PRETTY WELL IN HAND. FAIRLY DEEP LYR OF INSTAB
NOTED ON THE 12Z KBUF SNDG...INDICATIVE OF THE AMS WE`LL HAVE
THROUGH EARLY AFTN...AHD OF THE NEXT INCOMING S/WV. LIKELY POPS
FOR SNOW SHWRS OVER MOST OF CNY...WITH MORE SCTD ACTIVITY ACRS
MUCH OF NE PA...STILL SEEMS REASONABLE...WITH A FLUFFY 1-2"
ANTICIPATED IN THE MOST PERSISTENT SHSN. IT`S WORTH NOTING THAT
THE LATEST HRRR AND HI-RES ARW OUTPUT IN PARTICULAR SHOW A WELL
FORMED MULTI-BAND/FINGER LKS BAND FROM LTR THIS MRNG...THROUGH THE
AFTN...AND INTO THE EVE HRS...DOWN THE AXIS OF CAYUGA LAKE...AND THEN
SEWD FROM THERE THROUGH AT LEAST TOMPKINS/TIOGA CNTYS. SINCE THERE
ARE ALREADY SOME INDICATIONS OF BANDING IN THIS GENERAL AREA
ATTM...WE`LL MONITOR THAT CLOSELY THROUGH THE DAY.
GIVEN STG CAA THROUGHOUT THE COLUMN...SHARPLY FALLING TEMPS STILL
LOOK LIKELY...AND OUR PREVIOUSLY ADVERTISED TREND WAS KEPT IN TACT.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
2 PM FRI UPDATE... OVERALL...THINGS LOOK FAIRLY QUIET SAT-SUN
MRNG. WINDS SHOULD RELAX SAT...SO THE WIND CHILL EXPIRATION TIME
OF 16Z STILL LOOKS GOOD ATTM. A WEAK SFC FRNT AND NRN STREAM S/WV
ARE PROGGED TO TRAVERSE THE FA SAT NGT INTO THE FIRST PART OF
SUN...WITH ONLY SCTD LGT SNOW SHWRS AND FLRYS ANTICIPATED...AND
LTL IN THE WAY OF ACCUM.
RECENT GLOBAL MODEL TRENDS (GFS/EC/GEM) HAVE PERSISTED WITH THE
12Z FRI CYCLE...INDICATING A MORE AMPLIFIED UPR-LVL WV...FARTHER N
SFC LOW TRACK...AND RESULTANT INCREASED SNOWFALL POTENTIAL FOR
CNY/NE PA. MUCH MORE ON THIS SYSTEM IN THE FOLLOWING SXN. FOR
NOW...WE`VE BROUGHT THE LEADING EDGE OF STEADIER SNOW (CHC-LIKELY
POPS) INTO AT LEAST SWRN/SRN PTNS OF THE FA BY MID TO LATE AFTN ON SUN.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
EXTENDED PERIOD WILL SEE A CONTINUATION OF AN UPPER LEVEL TROF
ACROSS THE EASTERN UNITED STATES. TUESDAY/TUESDAY NIGHT, WILL BE
PRIMARILY DRY AND COLD AS HIGH PRES MOVES FROM THE OHIO VALLEY TO
THE MID ATLANTIC COAST. WEDNESDAY THROUGH THURSDAY, SFC LOW PRES
WILL TRACK THROUGH THE WESTERN LAKES AND INTO SOUTHERN QUEBEC. THE
TRAILING COLD FRONT WILL SWEEP THROUGH THE AREA WEDNESDAY NIGHT.
HIGHS ON WED WILL RANGE FROM THE UPPER 20S TO LOWER 30S BEFORE
ARCTIC AIR RETURNS TO THE REGION FOLLOWING THE COLD FRONT.
SCATTERED SNOW SHOWERS WILL BE POSSIBLE THROUGH THIS PERIOD DUE TO
FROPA AND COLD NORTHWEST FLOW ON THURSDAY. FRIDAY WILL BE DRY AS
SFC HIGH PRES BUILDS OVER THE NORTHEAST. TEMPS THURSDAY THROUGH
FRIDAY WILL BE BELOW NORMAL.
&&
.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
COLD NORTHWEST FLOW WILL KEEP LAKE EFFECT SNOW SHOWERS AND CIG
RESTRICTIONS OVER MOST OF THE TERMINALS THROUGH THIS AFTERNOON. AT
KRME, NORTHWEST FLOW WILL KEEP LAKE CLOUDS WEST OF TERMINAL WITH
VFR CONDITIONS EXPECTED THROUGH 00Z THEN AN APPROACHING SFC TROF
OVERNIGHT WILL BRING MVFR CIG RESTRICTIONS. AT KSYR, MVFR CIGS
THROUGH LATE MORNING WITH IFR SNOW SHOWERS POSSIBLE THROUGH 09Z.
MVFR CIGS RETURN OVERNIGHT AFTER 00Z. AT KITH/KBGM, MVFR CIGS
THROUGH TODAY WITH SNOW SHOWERS/FLURRIES CONTINUING AND IFR SNOW
SHOWERS POSSIBLE THROUGH DAYBREAK. AT KELM/KAVP, MVFR/LOW VFR CIGS
THROUGH MID MORNING THEN VFR UNTIL END OF TAF PERIOD.
NORTHWEST WINDS 8-12 KNOTS WITH GUSTS AROUND 25 KNOTS GRADUALLY
DECREASING THIS AFTERNOON. LIGHT SOUTHWEST WINDS THIS EVENING.
OUTLOOK...
SUN...MVFR RESTRICTIONS LIKELY FOR CIGS.
SUN NGT / MON... RESTRICTIONS LIKELY (MVFR/IFR) IN SNOW.
TUE...VFR.
WED...POSSIBLE RESTRICTIONS DUE TO SNOW SHOWERS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
AFTERNOON FOR PAZ038>040-043-044-047-048-072.
WIND CHILL ADVISORY UNTIL 11 AM EST THIS MORNING FOR
PAZ038>040-043-044-047-048-072.
NY...WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
AFTERNOON FOR NYZ015>018-022>025-036-037-044>046-055>057-
062.
WIND CHILL ADVISORY UNTIL 11 AM EST THIS MORNING FOR NYZ009-
015>018-022>025-036-037-044>046-055>057-062.
&&
$$
SYNOPSIS...MLJ
NEAR TERM...HEDEN/MLJ
SHORT TERM...MLJ
LONG TERM...RRM
AVIATION...RRM
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1248 AM EST SAT JAN 31 2015
.SYNOPSIS...
VERY COLD AIR WILL CONTINUE TO POUR INTO THE REGION TONIGHT...WITH
LAKE-EFFECT SNOW PERSISTING DOWNWIND FROM THE FINGER LAKES...AND
BITTERLY COLD WIND CHILLS AREA-WIDE. COLD TEMPERATURES WILL LAST
THROUGH THE UPCOMING WEEKEND...WITH ONLY A FEW FLURRIES FORESEEN
FROM SATURDAY INTO EARLY SUNDAY. AN APPROACHING WINTER STORM COULD
BEGIN TO IMPACT THE AREA BY LATE SUNDAY AFTERNOON OR SUNDAY
EVENING...WITH ACCUMULATING SNOW POSSIBLE.
&&
.NEAR TERM /THROUGH TODAY/...
945 PM UPDATE...
LAKE EFFECT SNOW CONTINUES DOWNWIND OF THE FINGER LAKES. RADAR
INTENSITY DOES NOT LOOK THAT STRONG BUT WITH SURFACE TEMPS THIS
COLD, FLUFF FACTOR IS PROBABLY IN FULL FORCE. ADVISORY THROUGH 1
AM LOOKS GOOD WITH ANOTHER INCH OR TWO POSSIBLE IN THE MOST
PERSISTENT BANDS. WIND CHILL VALUES ARE ALREADY IN THE -5 TO -10
RANGE AND EXPECTED TO DROP FURTHER OVERNIGHT, SO THE WIND CHILL
ADVISORY LOOKS GOOD. A QUICK MENTION OF THE POTENTIAL SNOW FOR
SUNDAY NIGHT INTO MONDAY. WE PUT A GRAPHIC ON SOCIAL MEDIA
(TWITTER/FACEBOOK) TO SHOW THE HIGHEST THREAT FOR SNOW AT THIS
POINT. PREVIOUS AFD IS BELOW.
145 PM UPDATE... ONLY MINOR TWEAKS MADE TO THE GRIDS THIS PD.
AREA-WIDE WIND CHILL ADVSY STILL LOOKS ON TRACK FOR THE OVERNIGHT
HRS...AS VERY STG 925-850 MB CAA THROUGH THIS EVE...SHOULD SEND
AIR TEMPS INTO THE SINGLE DIGITS ABV OR BLO ZERO TNT...WITH THE
PRES GRADIENT REMAINING RELATIVELY TIGHT THIS EVE...AND ONLY
SLOWLY RELAXING LATE. MOST AREAS SHOULD SEE APPARENT TEMPS IN THE
-10 TO -20 RANGE...WITH LOCALLY COLDER VALUES IN OUR FAR NRN AND
ERN ZNS.
AS FAR AS THE LES ADVSY GOES...NO CHGS ATTM. ALTHOUGH BLYR INSTAB
(TERRESTRIAL CAPE VALUES OF 15-30 J/KG) TEMPORARILY RESULTED IN A
MORE CELLULAR APPEARANCE TO THE SNOW SHWRS EARLIER THIS AFTN
LOW-LVL STABILIZATION AND INCRG SHEAR SHOULD RESULT IN THE RE-
EMERGENCE OF WELL DEFINED BANDS BY 21Z OR SO. IN FACT...EVIDENCE
OF SUCH IS ALREADY SEEN ON KBGM RADAR IMAGERY ATTM. MOST HI-RES
MODEL GUIDANCE HINTS THAT MULTI-BANDS/FINGER LKS BANDS WILL REMAIN
AT PLAY TIL AT LEAST 06-12Z SAT. OVERALL...INTENSITY SHOULD WANE
AFTER 06Z...AS MODEL SNDGS SHOW THE CAPPING INVERSION LWRG TO AOB
875-900 MB. WE`LL STICK WITH OUR 3-6" TOTALS FOR NOW...ALTHOUGH
WUDN`T BE SURPRISED TO SEE LOCALLY HIER AMTS...SPCLY IN SERN
TOMPKINS AND/OR NRN TIOGA.
OUTSIDE OF MULTI-BAND AREAS...EITHER WIDELY SCTD -SHSN/FLRYS...OR
JUST DRY WX...IS FORESEEN.
PREV DISC... 10 AM UPDATE... WE`VE ISSUED A LES ADVSY FOR
TOMPKINS...TIOGA...BROOME...AND SUSQ CNTYS...AS CONFIDENCE HAS
BECOME FAIRLY HIGH IN THE MAINTENANCE OF A WELL DVLPD FINGER LKS
BAND...THROUGH AT LEAST 00-03Z THIS EVE. OUR FIRST STAB AT SNOW
TOTALS IS 3-6"...BUT LOCALLY HIER AMTS ARE CERTAINLY PSBL.
NO OTHER SIG CHGS ATTM.
EARLIER DISC... 830 AM UPDATE... SN/+SN IS BEING OBSERVED ATTM
WITHIN A SW-NE ORIENTED BAND ACRS NE PA AND PTNS OF THE WRN
CATSKILLS. THIS FEATURE IS ON THE NWRN/DEFORMATION SIDE OF A S/WV
LIFTING THROUGH THE RGN THIS MRNG. POP/WX/SNOWFALL GRIDS WERE
UPDATED TO REFLECT SUCH DVLPMTS. WE`VE ADDED A CORRIDOR OF 2-3"
ADDNL SNOWFALL WITHIN THE AFOREMENTIONED BAND AREA THROUGH
15-16Z. A SHORT-TERM SPS WAS ALSO ISSUED.
OTHWS...THE FCST IS PRETTY WELL IN HAND. FAIRLY DEEP LYR OF INSTAB
NOTED ON THE 12Z KBUF SNDG...INDICATIVE OF THE AMS WE`LL HAVE
THROUGH EARLY AFTN...AHD OF THE NEXT INCOMING S/WV. LIKELY POPS
FOR SNOW SHWRS OVER MOST OF CNY...WITH MORE SCTD ACTIVITY ACRS
MUCH OF NE PA...STILL SEEMS REASONABLE...WITH A FLUFFY 1-2"
ANTICIPATED IN THE MOST PERSISTENT SHSN. IT`S WORTH NOTING THAT
THE LATEST HRRR AND HI-RES ARW OUTPUT IN PARTICULAR SHOW A WELL
FORMED MULTI-BAND/FINGER LKS BAND FROM LTR THIS MRNG...THROUGH THE
AFTN...AND INTO THE EVE HRS...DOWN THE AXIS OF CAYUGA LAKE...AND THEN
SEWD FROM THERE THROUGH AT LEAST TOMPKINS/TIOGA CNTYS. SINCE THERE
ARE ALREADY SOME INDICATIONS OF BANDING IN THIS GENERAL AREA
ATTM...WE`LL MONITOR THAT CLOSELY THROUGH THE DAY.
GIVEN STG CAA THROUGHOUT THE COLUMN...SHARPLY FALLING TEMPS STILL
LOOK LIKELY...AND OUR PREVIOUSLY ADVERTISED TREND WAS KEPT IN TACT.
&&
.SHORT TERM /TONIGHT THROUGH 6 PM SUNDAY/...
2 PM FRI UPDATE... OVERALL...THINGS LOOK FAIRLY QUIET SAT-SUN
MRNG. WINDS SHOULD RELAX SAT...SO THE WIND CHILL EXPIRATION TIME
OF 16Z STILL LOOKS GOOD ATTM. A WEAK SFC FRNT AND NRN STREAM S/WV
ARE PROGGED TO TRAVERSE THE FA SAT NGT INTO THE FIRST PART OF
SUN...WITH ONLY SCTD LGT SNOW SHWRS AND FLRYS ANTICIPATED...AND
LTL IN THE WAY OF ACCUM.
RECENT GLOBAL MODEL TRENDS (GFS/EC/GEM) HAVE PERSISTED WITH THE
12Z FRI CYCLE...INDICATING A MORE AMPLIFIED UPR-LVL WV...FARTHER N
SFC LOW TRACK...AND RESULTANT INCREASED SNOWFALL POTENTIAL FOR
CNY/NE PA. MUCH MORE ON THIS SYSTEM IN THE FOLLOWING SXN. FOR
NOW...WE`VE BROUGHT THE LEADING EDGE OF STEADIER SNOW (CHC-LIKELY
POPS) INTO AT LEAST SWRN/SRN PTNS OF THE FA BY MID TO LATE AFTN ON SUN.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
CONFIDENCE IS GROWING THAT THE AREA WILL BE AFFECTED BY A MOISTURE LADEN STORM
SYSTEM AS IT MOVES FROM THE OHIO VALLEY OFF THE EAST COAST SUNDAY
NIGHT INTO MONDAY. EXPECT SNOW TO CONTINUE OVERSPREADING THE
REGION SUNDAY EVENING AND POTENTIALLY BECOME HEAVY AT TIMES
OVERNIGHT INTO EARLY MONDAY. AS THIS EVENT IS STILL MORE THAN 48
HOURS OUT, THERE IS STILL A LOT OF UNCERTAINTY IN THE DETAILS OF
THE SYSTEM AND IT`S EXACT TRACK BUT AS DISCUSSED ABOVE FORECAST
GUIDANCE HAS COME INTO BETTER AGREEMENT WITH THIS UPDATE CYCLE.
THE TRACK OF THE LOW SOUTH OF THE CWA SHOULD RESULT IN THE HEAVIER
AMOUNTS (POTENTIALLY 6+ INCHES) GENERALLY OCCURRING ACROSS NE PA
NORTHWARD ACROSS THE SOUTHERN TIER OF UPSTATE NEW YORK THEN EAST
INTO THE CATSKILLS WITH LIGHTER AMOUNTS FARTHER NORTH. WORTH
NOTING, HOWEVER, IS THAT IF THE LOW TRACK WERE TO TREND EVEN
FARTHER NORTH THIS COULD INTRODUCE MIXED PRECIP INTO NE PA CUTTING
AMOUNTS DOWN THERE AND RESULTING IN MORE WIDESPREAD HIGHER TOTALS
OVER NY. SO, AS MENTIONED, STILL UNCERTAINTY SO WE WILL HOLD OFF
ON WATCH AT THIS TIME. FINALLY, THE ARCTIC AIR IN PLACE AHEAD OF
THIS SYSTEM WILL ALSO RESULT IN THIS BEING A VERY COLD EVENT WITH
TEMPS GENERALLY IN THE TEENS AND EVEN SINGLE DIGITS IN THE FAR NORTH WHICH
WILL BE ACCOMPANIED BY INCREASING WINDS LATER MONDAY.
EXPECT SNOW TO WIND DOWN BY LATER MONDAY WITH SOME LAKE EFFECT
POSSIBLE IN IT`S WAKE MONDAY NIGHT. ALSO EXPECT VERY COLD TEMPS BY
LATER MONDAY NIGHT AS ARCTIC HIGH BUILDS IN WITH WIDESPREAD
SUBZERO READINGS. TUESDAY WILL BE GENERALLY FAIR BUT COLD WITH
BRIEF MODERATION TO SEASONAL WEDNESDAY BEFORE ANOTHER ARCTIC FRONT MOVES
THROUGH LATE WEDNESDAY WITH SNOW SHOWERS AND COLDER TEMPS TO
FOLLOW FOR THE END OF THE WEEK. NW FLOW ALSO WILL BRING THE
POTENTIAL FOR SOME LAKE EFFECT INTO THURSDAY.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
COLD NORTHWEST FLOW WILL KEEP LAKE EFFECT SNOW SHOWERS AND CIG
RESTRICTIONS OVER MOST OF THE TERMINALS THROUGH THIS AFTERNOON. AT
KRME, NORTHWEST FLOW WILL KEEP LAKE CLOUDS WEST OF TERMINAL WITH
VFR CONDITIONS EXPECTED THROUGH 00Z THEN AN APPROACHING SFC TROF
OVERNIGHT WILL BRING MVFR CIG RESTRICTIONS. AT KSYR, MVFR CIGS
THROUGH LATE MORNING WITH IFR SNOW SHOWERS POSSIBLE THROUGH 09Z.
MVFR CIGS RETURN OVERNIGHT AFTER 00Z. AT KITH/KBGM, MVFR CIGS
THROUGH TODAY WITH SNOW SHOWERS/FLURRIES CONTINUING AND IFR SNOW
SHOWERS POSSIBLE THROUGH DAYBREAK. AT KELM/KAVP, MVFR/LOW VFR CIGS
THROUGH MID MORNING THEN VFR UNTIL END OF TAF PERIOD.
NORTHWEST WINDS 8-12 KNOTS WITH GUSTS AROUND 25 KNOTS GRADUALLY
DECREASING THIS AFTERNOON. LIGHT SOUTHWEST WINDS THIS EVENING.
OUTLOOK...
SUN...MVFR RESTRICTIONS LIKELY FOR CIGS.
SUN NGT / MON... RESTRICTIONS LIKELY (MVFR/IFR) IN SNOW.
TUE...VFR.
WED...POSSIBLE RESTRICTIONS DUE TO SNOW SHOWERS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WIND CHILL ADVISORY UNTIL 11 AM EST THIS MORNING FOR
PAZ038>040-043-044-047-048-072.
LAKE EFFECT SNOW ADVISORY UNTIL 1 AM EST EARLY THIS MORNING
FOR PAZ039.
NY...WIND CHILL ADVISORY UNTIL 11 AM EST THIS MORNING FOR NYZ009-
015>018-022>025-036-037-044>046-055>057-062.
LAKE EFFECT SNOW ADVISORY UNTIL 1 AM EST EARLY THIS MORNING
FOR NYZ025-055-056.
&&
$$
SYNOPSIS...MLJ
NEAR TERM...HEDEN/MLJ
SHORT TERM...MLJ
LONG TERM...PCF
AVIATION...RRM
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
542 AM EST SAT JAN 31 2015
.SYNOPSIS...
HIGH PRESSURE WILL PUSH SOUTH INTO THE AREA TODAY. THE HIGH WILL
SHIFT INTO THE ATLANTIC SUNDAY...WHILE A WEAK COASTAL TROUGH
DEVELOPS AND LIFTS NORTH AHEAD OF A COLD FRONT PASSING OVER THE
AREA MONDAY. HIGH PRESSURE WILL THEN RETURN TO THE REGION BY
TUESDAY...BEFORE SHIFTING OFFSHORE AHEAD OF ANOTHER STORM SYSTEM
APPROACHING FROM THE GULF OF MEXICO BY LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE ONLY CHANGE MADE FOR THE SUNRISE UPDATE WAS TO INCREASE CLOUD
COVER ACROSS SOUTHEAST GEORGIA TODAY. SATELLITE SHOWS A THICK
PLUME OF HIGH-LEVEL MOISTURE MOVING QUICKLY ACROSS NORTHERN
ALABAMA INTO NORTHWEST GEORGIA. THE LATEST RAP RH PROGNOSTICATIONS
SHOW SOME OF THIS ACTIVITY REACHING SOUTH OF THE SAVANNAH RIVER
LATER TODAY. THE REST OF THE FORECAST STILL LOOKS ON TRACK.
HIGH PRESSURE WILL EXTEND ACROSS THE REGION TODAY AS MID/UPPER-
LEVEL HEIGHTS BUILD ALOFT. EXPECT ANOTHER QUIET DAY FOR THE
COASTAL EMPIRE AND LOWCOUNTRY GIVEN THIS REGIME. A BAND OF
THIN CIRRUS IS MOVING ACROSS THE FAR SOUTHERN PORTIONS OF THE
FORECAST AREA THIS MORNING. THESE CLOUDS ARE FORECAST TO PUSH
SOUTH AND DIMINISH OVER THE NEXT COUPLE OF HOURS AS THE SUPPORTING
125 KT 250 HPA JET STREAM SHIFTS NORTH IN RESPONSE TO MEAN 850-200
HPA RIDGING. HIGHS WILL RANGE FROM THE LOWER-MID 50S NORTH AREAS
TO THE MID- UPPER 50S CENTRAL AND SOUTHERN AREAS. NORTH/NORTHEAST
WINDS THIS MORNING WILL GRADUALLY VEER ONSHORE THIS AFTERNOON AS
THE CENTER OF THE SURFACE HIGH SHIFTS SOUTH. THE RESULTING ONSHORE
FLOW WILL KEEP COASTAL LOCATIONS RATHER CHILLY WITH HIGHS LIKELY
BEING LIMITED TO THE UPPER 40S/NEAR 50 RIGHT ALONG THE BEACHES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
TONIGHT...DEEP LAYERED RIDGING WILL REMAIN FIRMLY ENTRENCHED
ACROSS THE SOUTHEAST U.S. TONIGHT WITH THE CENTER OF THE SURFACE
HIGH FORECAST TO SHIFT SLOWLY OFF THE SOUTH CAROLINA COAST. THICK
CIRRUS ASSOCIATED WITH A SHORTWAVE ROUNDING THE WESTERN FLANKS OF
THE MEAN RIDGE AXIS WILL SPREAD QUITE A BIT OF HIGH CLOUDINESS
ACROSS THE REGION AFTER MIDNIGHT. 31/00Z NSSL-WRF/GEM SIMULATED
CLOUD PRODUCTS SUGGEST SKIES WILL GENERALLY REMAIN PARTLY TO
MOSTLY CLOUDY. THE INCREASED CLOUD COVER COUPLED WITH WEAK
925-850 HPA WARM AIR ADVECTION WILL YIELD A WARMER NIGHT THAN THIS
MORNING WITH LOWS RANGING FROM THE LOWER 30S INTERIOR SOUTHEAST
SOUTH CAROLINA TO THE MID-UPPER 30S ELSEWHERE...EXCEPT THE LOWER
40S ALONG THE BEACHES AND BARRIER ISLANDS.
SUNDAY...SURFACE HIGH PRESSURE WILL BE STEADILY SLIPPING FARTHER
INTO THE ATLANTIC DURING THE MORNING HOURS...JUST DOWNSTREAM OF A
DEEPENING LOW PRESSURE SYSTEM MOVING INTO THE TENNESSEE VALLEY BY
MIDDAY. A WEAK COASTAL TROUGH WILL DEVELOP ALONG THE PERIPHERY OF
THE RETREATING HIGH PRESSURE EARLY...SHIFTING TOWARD THE COAST AND
LIFTING NORTH AS A WARM FRONTAL FEATURE LATE IN THE DAY. THE
FORECAST AREA WILL LIKELY REMAIN BETWEEN MARINE SHOWERS TO THE
EAST/NORTHEAST AND CONVECTION TO THE WEST ASSOCIATED WITH THE
APPROACHING COLD FRONT. HAVE THUS WAITED UNTIL LATE AFTERNOON TO
INDICATE ISOLATED TO SCATTERED SHOWERS SPREADING INTO THE FORECAST
AREA. DESPITE THICKENING CLOUD COVER...TEMPERATURES WILL BECOME
QUITE WARM FOR EARLY FEBRUARY WITHIN SOLID SOUTHERLY FLOW. EXPECT
TEMPERATURES TO PEAK IN THE MID TO UPPER 60S AWAY FROM THE LOCALLY
COOLER COAST.
SUNDAY NIGHT AND MONDAY...A ROBUST UPPER TROUGH WILL SWEEP TOWARD
THE EAST COAST AND ASSIST IN THE PROGRESSION OF THE COLD FRONT
THROUGH THE FORECAST AREA DURING THE MORNING HOURS MONDAY. LOW
TEMPERATURES SUNDAY NIGHT WILL BE QUITE MILD IN THE 50S DUE TO THE
COMBINED EFFECTS OF INSULATING CLOUD COVER AND A WELL MIXED
ATMOSPHERE WITHIN SOLID SOUTHWEST FLOW. THE HIGHEST RAIN COVERAGE IS
EXPECTED FROM SUNSET SUNDAY THROUGH EARLY MONDAY MORNING...WHEN BEST
FORCING FOR CONVERGENCE ALONG THE FRONTAL ZONE AND THE NOSE OF A 130
KT UPPER JET MOVES INTO THE AREA. DUE TO SOME SLIGHT TIMING
DIFFERENCES IN THE MODELS...WILL KEEP RAIN CHANCES JUST BELOW 80
PERCENT...WHICH IS STILL A FAIRLY HIGH CONFIDENCE FORECAST. THE
FRONT WILL LIKELY BE OFFSHORE BY MONDAY AFTERNOON...WITH DRIER AIR
BEGINNING TO FILTER INTO THE REGION AHEAD OF BUILDING HIGH PRESSURE.
RAIN CHANCES WILL THUS END FROM WEST TO EAST AS THE DAY PROGRESSES.
HIGH TEMPERATURES MONDAY AFTERNOON WILL BE WITHIN A FEW DEGREES OF
SEASONAL NORMALS...RANGING FROM THE UPPER 50S FAR INLAND TO THE LOW
60S EAST. IT SHOULD BE NOTED THAT BREEZY TO GUSTY WINDS WILL DEVELOP
SUNDAY NIGHT THROUGH MONDAY AFTERNOON...AS AN IMPRESSIVE 50 KT LOW
LEVEL JET MOVES ACROSS THE AREA OVERNIGHT...AND A LARGE PRESSURE
GRADIENT DEVELOPS IN THE WAKE OF THE FRONT DURING THE DAYTIME HOURS.
WEST/NORTHWEST WINDS COULD PEAK AT 20 TO 30 MPH.
MONDAY NIGHT AND TUESDAY...THE PRESSURE GRADIENT WILL BEGIN TO
WEAKEN AS SURFACE HIGH PRESSURE MOVES INTO THE MID ATLANTIC AND
SOUTHEAST STATES...EVENTUALLY BECOMING LOCATED ALONG THE COASTLINE
BY TUESDAY AFTERNOON. A MUCH COOLER AIR MASS WILL HAVE MOVED INTO
THE REGION...AND EXPECT NOTABLY COLDER LOW TEMPERATURES MONDAY NIGHT
IN THE UPPER 20S INLAND TO THE LOW 30S CLOSER TO THE COAST. HIGH
TEMPERATURES ON TUESDAY WILL BE NEARLY 10 DEGREES COOLER THAN THE
PREVIOUS DAY...SUPPRESSED IN THE LOW TO MID 50S WITHIN SOLID
NORTHEAST FLOW.
LAKE WINDS...GUSTY CONDITIONS ARE EXPECTED ALONG THE LAKE SHORE OF
LAKE MOULTRIE MONDAY...HOWEVER MIXING WILL BE RESTRICTED SOMEWHAT
OVER THE BULK OF THE LAKE WATERS. AS A RESULT...THERE REMAINS SOME
UNCERTAINTY AS TO WHETHER A LAKE WIND ADVISORY WILL BE REQUIRED.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
TRANSIENT SURFACE HIGH PRESSURE WILL MOVE INTO THE ATLANTIC TUESDAY
NIGHT. A COASTAL TROUGH WILL ONCE AGAIN DEVELOP ALONG THE PERIPHERY
OF THE ATLANTIC HIGH ON WEDNESDAY...WHILE A SOUTHERN STREAM
SHORTWAVE DEVELOPS FAR TO THE WEST ACROSS TEXAS AND SUPPORTS THE
DEVELOPMENT OF A SURFACE LOW IN THE GULF OF MEXICO. ALTHOUGH THE
INITIAL SHORTWAVE WILL DAMPEN LATE WEDNESDAY...THE SURFACE LOW WILL
CONTINUE TO TAKE SHAPE AND MOVE EAST ACROSS THE GULF. NUMERICAL
MODEL SOLUTIONS DIVERGE QUITE NOTABLY REGARDING THE STRENGTH OF THE
LOW PRESSURE WAVE AND THE PRESENCE OF ADDITIONAL SHORTWAVE ENERGY
DIVING INTO THE GULF COAST STATES OR SOUTHEAST LATE THURSDAY INTO
FRIDAY. AS A RESULT...CONFIDENCE IN FORECAST DETAILS BECOMES RATHER
LOW FOR THE LATE WEEK PERIOD.
AFTER A PERIOD OF DRY WEATHER EARLY IN THE WEEK...HAVE REINTRODUCED
RAIN CHANCES BY WEDNESDAY TO ACCOUNT FOR MARINE SHOWERS PROGRESSING
ONSHORE FROM THE COASTAL TROUGH. HAVE THEN INCREASED RAIN COVERAGE
WEDNESDAY NIGHT INTO THURSDAY...AS MEDIUM RANGE MODELS ARE IN
GENERAL AGREEMENT THAT SOME DEGREE OF RAIN WILL BE AFFECTING THE
FORECAST AREA DURING THIS TIME FRAME. MODEL SOLUTIONS THAT INDICATE
THE SECOND WAVE OF UPPER LEVEL ENERGY LATE THURSDAY INTO FRIDAY
MAINTAIN RAIN COVERAGE ACROSS THE REGION ACCORDINGLY...YET WILL CAP
RAIN POTENTIAL NO HIGHER THAN SLIGHT CHANCE THROUGH FRIDAY UNTIL
MODELS COME INTO BETTER AGREEMENT. HAVE INDICATED RAIN CHANCES
FALLING BELOW 10 PERCENT BY SATURDAY...WITH ANY COASTAL LOW SYSTEM
LIKELY LIFTING AWAY BY THE WEEKEND.
HIGH TEMPERATURES WILL BE IN THE UPPER 50S TO LOWER 60S WEDNESDAY
AND THURSDAY AFTERNOONS...BEFORE A NOTABLE COOLING TREND OCCURS ON
THE BACK SIDE OF THE LOW PRESSURE SYSTEM FRIDAY AND SATURDAY.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
VFR WITH LIGHT WINDS THROUGH THE PERIOD.
EXTENDED AVIATION OUTLOOK...VFR CONDITIONS WILL PREVAIL UNTIL SUNDAY
NIGHT INTO MONDAY MORNING...WHEN MVFR OR POSSIBLY LOWER CONDITIONS
ARE LIKELY DUE TO A PASSING COLD FRONT. BREEZY CONDITIONS AND/OR
WIND SHEAR IS ALSO LIKELY SUNDAY NIGHT/MONDAY.
&&
.MARINE...
TODAY...EXPECT BOTH WINDS AND SEAS TO DIMINISH TODAY AS HIGH
PRESSURE SHIFTS SOUTH. GUSTY NORTH WINDS THIS MORNING WILL
SETTLE INTO THE 5-10 KT RANGE OVER THE CHARLESTON COUNTY WATERS
AND CHARLESTON HARBOR THIS AFTERNOON WITH 10-15 KT ELSEWHERE. SEAS
WILL AVERAGE 2-3 FT NEARSHORE WATERS AND 3-4 FT OFFSHORE WATERS.
TONIGHT...EAST WINDS WILL BACK VEER SOUTHEAST OVERNIGHT WITH WINDS
GENERALLY REMAINING LESS THAN 10 KT. SEAS WILL AVERAGE 1-2 FT
NEARSHORE WATERS WITH 2-3 FT OFFSHORE WATERS.
SUNDAY AND MONDAY...SURFACE HIGH PRESSURE WILL CONTINUE
TO TRACK INTO THE ATLANTIC SUNDAY. THE PRESSURE GRADIENT WILL THEN
TIGHTEN BETWEEN THE ATLANTIC HIGH AND AN UPSTREAM LOW AND TRAILING
COLD FRONT SWEEPING THROUGH THE MARINE ZONES MONDAY. COLD ADVECTION
THAT SUPPORTS MIXING INTO A NOTABLE 40 TO 50 KT LOW LEVEL JET WILL
EASILY ALLOW CONDITIONS TO REACH SOLID SMALL CRAFT ADVISORY
THRESHOLDS...WITH A RISK FOR POSSIBLE GALES ACROSS THE CHARLESTON
COUNTY WATERS AND OFFSHORE GEORGIA ZONES.
ALTHOUGH CONFIDENCE IS NOT HIGH ENOUGH TO INCLUDE EXPLICITLY IN THE
FORECAST...WILL CONTINUE TO NOTE THE SMALL POTENTIAL FOR SEA FOG
SUNDAY EVENING IF THE INCREASE IN WINDS ARE DELAYED...AS WELL AS A
RISK FOR SOME STRONGER THUNDERSTORMS OUT NEAR THE GULF STREAM IN
ADVANCE OF THE COLD FRONT.
TUESDAY THROUGH WEDNESDAY...A TRANSIENT HIGH PRESSURE WEDGE WILL
PREVAIL AS LOW PRESSURE EVENTUALLY DEVELOPS IN THE WEST/NORTHWEST
GULF AND A COASTAL TROUGH ATTEMPTS TO FORM NEARBY. LATEST PROGNOSIS
IS THAT CONDITIONS REMAIN BELOW THE ADVISORY CRITERIA DURING THIS
TIME.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
ST/WMS
AREA FORECAST DISCUSSION
NWS DULUTH MN
600 AM CST SAT JAN 31 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 348 AM CST SAT JAN 31 2015
MAIN CONCERNS IN THE SHORT TERM REMAIN FOCUSED AROUND THE LIGHT
SNOW SHOWERS ACROSS NORTH CENTRAL WISCONSIN TODAY...WITH A BETTER
CHANCE OF LIGHT ACCUMULATING LAKE EFFECT SNOW ALONG THE SOUTH
SHORE FROM THE TWIN PORTS TO ASHLAND TONIGHT THROUGH SUNDAY. ALSO
CONCERNED ABOUT THE VERY COLD TEMPERATURES AND POTENTIALLY
DANGEROUS WIND CHILLS EXPECTED ALONG AND NORTH OF THE IRON RANGE
TONIGHT/SUN MORNING.
UPPER SHORT WAVE AND ASSOCIATED SFC TROUGH ARE CURRENTLY MOVING NW
TO SE ACROSS THE REGION THIS MORNING WITH NW WINDS PICKING UP AND A
FAIRLY COLD AIR MASS FILTERING IN BEHIND THE FRONT. TEMPERATURES
WILL BE SLOWLY FALLING OR REMAINING STEADY THROUGH THE DAY WITH
HIGHS IN THE SINGLE DIGITS AND TEENS IN NE MN AND INTO THE UPPER
TEENS AND LOWER 20S IN NW WI. THE CAA ALOFT WILL AID IN THE
CONTINUOUS CLOUD COVER OVER MUCH OF THE NORTHLAND TODAY WITH A
SLIGHT ENHANCEMENT OF LAKE SNOW SHOWERS AROUND THE SNOW BELT
REGION OF NRN WI. ONLY LIGHT OR TRACE AMTS OF SNOW ARE EXPECTED
TODAY.
THE ARCTIC AIR MASS WILL BEGIN TO IMPINGE UPON THE NORTHLAND
FROM THE NORTH TONIGHT WITH 850MB TEMPS -15 TO -25 DEG C MOVING
INTO THE BORDERLAND AREA AND THE TIP OF THE ARROWHEAD. SKIES WILL
CLEAR OUT OVER THE NRN COUNTIES TONIGHT AND ALLOW SURFACE
TEMPERATURES TO FALL INTO THE TEENS AND LOWER 20S BELOW
ZERO...WITH LIGHT NORTH WINDS PRODUCING WIND CHILLS BELOW -30 F.
WIND CHILL ADVISORIES MAY BE NEEDED.
AS THIS COLD AIR MASS DROPS IN AND A POTENT WINTER STORM SYSTEM
TRACKS EWD THROUGH THE MID MS VALLEY AND SRN GREAT LAKES
AREA TONIGHT...FAVORABLE N/NE WINDS WILL DEVELOP ACROSS WRN LAKE
SUPERIOR AND BEGIN TO FORM LAKE EFFECT SNOW SHOWERS ALONG THE
SOUTH SHORE. HAVE INCREASED POPS AND THE POTENTIAL FOR LIGHT
ACCUMULATING SNOW FROM THE TWIN PORTS EWD TO ASHLAND THROUGH
SUNDAY WITH UP TO 3 INCHES OF SNOW POSSIBLE. HIGHER AMTS ARE NOT
OUT OF THE QUESTION IF A LAKE BAND SETS UP OVER THE SAME AREA FOR
AN EXTENDED PERIOD OF TIME. DRIER AIR WILL BEGIN TO MOVE IN FROM
THE WEST LATE SUN AFTERNOON.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 348 AM CST SAT JAN 31 2015
THE PERIOD WILL BE RELATIVELY QUIET WITH REGARDS TO STRONG SYSTEMS
PRODUCING SIGNIFICANT SNOWFALL. IT WILL MOSTLY BE COLD WITH HIGHS
FROM 5 TO NEARLY 15 DEGREES BELOW NORMAL.
SUNDAY NIGHT AND MONDAY WILL BE DRY FOR MOST AREAS AS HIGH PRESSURE
MOVES SOUTHEAST OF THE REGION AND A TROUGH OF LOW PRESSURE MOVES IN
FOR MONDAY. WE INCREASED CLOUD COVER MONDAY BUT LEFT THE MENTION OF
SNOW OUT. FORECAST SOUNDINGS SHOW A FAIRLY DRY LOW LAYER THAT
SUPPORTS NO MENTION SNOW ATTM.
AN AREA OF LOW PRESSURE WILL TRACK FROM THE NORTHERN PLAINS THROUGH
THE CENTRAL PLAINS MONDAY NIGHT INTO TUESDAY EVENING. THERE IS SOME
DISAGREEMENT ON THE TRACK OF THIS SYSTEM...BUT ALL THE MODELS DO
HAVE A SOLUTION FAR ENOUGH SOUTH TO KEEP SIGNIFICANT SNOWFALL OUT
OF THE NORTHLAND. THE EXCEPTION WOULD BE SOME LAKE EFFECT ALONG THE
SOUTH SHORE. A REINFORCING SHOT OF COLD AIR WILL MOVE IN
TUESDAY/TUESDAY NIGHT AS HIGH PRESSURE BUILDS SOUTH INTO THE
NORTHERN PLAINS BEHIND THE DEPARTING LOW. THE COLDER AIR AND
NORTHWEST WINDS WILL BRING A CHANCE FOR SNOW SHOWERS ALONG THE SOUTH
SHORE TUESDAY/TUESDAY NIGHT.
OUTSIDE OF SOME LAKE EFFECT CHANCES...WE WENT WITH A DRY FORECAST
FOR THE REST OF THE PERIOD FROM WEDNESDAY INTO FRIDAY. THERE ARE
SOME INDICATIONS THAT WE MAY NEED TO ADD SOME POPS ON FRIDAY...BUT
WE WILL WAIT FOR BETTER MODEL CONTINUITY BEFORE ADDING.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 600 AM CST SAT JAN 31 2015
MVFR CONDITIONS COVERED THE NORTHLAND EARLY THIS MORNING WITH SOME
SNOW SHOWERS OCCURRING OVER FAR NORTHERN MINNESOTA. THE RAP HAS A
DECENT HANDLE ON THE CURRENT CLOUD TRENDS...AND GRADUALLY SHOWS
CLEARING FROM NORTH TO SOUTH. THE LOW LEVEL FLOW WILL VEER THROUGH
THE DAY TO NORTH TO NORTHEAST AND WILL CAUSE THE CLOUDS TO LINGER
LONGER OVER ALL BUT KINL. WE DID DELAY THE IMPROVEMENT TO VFR AT
ALL TAF SITES.
AS THE LOW LEVEL FLOW BECOMES MORE NORTHEAST...LAKE INDUCED CLOUDS
AND PERHAPS SOME LIGHT SNOW WILL OCCUR ALONG THE SOUTH SHORE AND
AS FAR SOUTH AND WEST AS KHYR/KDLH TONIGHT. THE AIRMASS WILL BE
QUITE DRY...BUT THE FETCH IS LONG AND LOW LEVEL STABILITY LOW
WITH 850MB TEMPS DROPPING TO AROUND -18C ALONG THE SOUTH SHORE. WE
MAY NEED TO LOWER VSBYS AT KDLH WITH LATER UPDATES...BUT THAT WILL
BE A SHORTER TERM ISSUE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 16 -1 8 -8 / 10 30 10 0
INL 5 -19 1 -19 / 0 0 0 0
BRD 18 -1 8 -5 / 10 10 10 0
HYR 21 3 10 -11 / 10 10 10 0
ASX 20 6 9 -7 / 30 60 50 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...BJT
LONG TERM...MELDE
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS BILLINGS MT
306 AM MST SAT JAN 31 2015
.SHORT TERM...VALID FOR TDY AND SUN...
COLD FRONT MOVING INTO NORTHERN MONTANA THIS MORNING BUT NOT VERY
ARCTIC LIKE WITH TEMPERATURES ONLY DOWN TO 18 DEGREES AT CALGARY.
HOWEVER ITS A BIG AIRMASS CHANGE FROM WE HAVE BEEN EXPERIENCING
AND TEMPERATURES WILL BECOME MUCH COLDER TODAY DURING THE
AFTERNOON HOURS. AHEAD OF THE FRONTAL ARRIVAL THERE IS A PATCH OF
STRATUS THAT IS TRYING TO PROGRESS INTO NORTHERN SECTIONS OF
SOUTHEAST MONTANA BUT CLOUD COVER IS CAUSING IT SLOW ITS MOVEMENT.
STILL EXPECT THIS STRATUS TO GET CLOSE TO A BAKER TO MILES CITY
LINE BY SUNRISE AND SOME PATCHES OF FREEZING FOG ARE EXPECTED.
FRONT WILL PROGRESS THROUGH THE AREA FROM NORTH TO SOUTH THROUGH
THE LATE MORNING AND EARLY AFTERNOON HOURS WITH ITS PROGRESS A BIT
FASTER THROUGH SOUTHEAST MONTANA. MODELS SHOW LIGHT SNOW
DEVELOPING MAINLY IN THE POST FRONTAL AREA IN SOUTHEAST MONTANA AS
SHORTWAVE ENERGY TRACKS OVER THE AREA LATER IN THE DAY. HRRR SHOWS
ANOTHER AREA OF SNOW DEVELOPING IN THE BILLINGS AREA AND LOCATIONS
30 MILES SOUTH AND WEST AS UPSLOPE PLAYS A FACTOR IN PROVIDING
LIFT. THIS WINDOW FOR SNOW ALREADY DISSIPATES BY MIDNIGHT AS
HEIGHTS BEGIN TO BUILD ALOFT AND THE COLD AIR PUSH BEGINS TO
TRANSLATE EAST. GIVEN THE SHORT WINDOW AND NOT A STRONG ALIGNMENT
FOR LIFT CONFIDENT SNOW AMOUNTS WILL BE LIGHT AND GENERALLY AROUND
AN INCH THOUGH A FEW LOCATIONS COULD SEE CLOSER TO 2. BIGGER
THREAT IS THE SNOW FALLING ON WARM ROADS AND MELTING AND FREEZING.
THIS STILL LOOKS REASONABLE ESPECIALLY IF A FEW HOURS OF SUNSHINE
OCCUR BEFORE THE FRONT. CURRENT IR IMAGERY INDICATES THIS IS
LIKELY ESPECIALLY FOR THE WESTERN HALF OF THE AREA.
TEMPERATURES WILL BE FALLING FROM THE MID TO UPPER 30S THIS
MORNING THROUGH THE 20S THIS AFTERNOON. LOWS WILL SETTLE IN THE 5
TO 15 DEGREE RANGE OVERNIGHT. COLD BY COMPARISON TO THIS PAST WEEK
BUT NOT DRAMATIC FOR JANUARY.
SUNDAY THE AIRMASS MODERATES AS THE DEEPER COLD AIR MOVES AWAY
FROM THE REGION WITH A WARM FRONT MOVING INTO THE WESTERN ZONES BY
LATE AFTERNOON AND ACROSS THE AREA SUNDAY NIGHT. MOST OF THE DAY
WILL BE DRY BUT THE WARM FRONT DOES INCREASE MOISTURE OVER THE
WESTERN ZONES WHICH WILL BRING A CHANCE FOR MOUNTAINS SNOW. BORSUM
.LONG TERM...VALID FOR MON...TUE...WED...THU...FRI...
LITTLE IN THE WAY OF CHANGES TO THE EXTENDED FORECAST PERIOD...AS
THE OVERALL STORY REMAINS THE SAME. COLDER AND UNSETTLED WEATHER
TO START THE WORK WEEK...WITH A RETURN TO ABOVE SEASONAL AVERAGE
TEMPERATURES TO END THE WEEK.
MODELS CONTINUE TO HAVE TIMING DIFFERENCES FOR ARCTIC
INTRUSION...BUT GENERAL CONSENSUS POINTS TOWARD BEST PRECIP
POTENTIAL ON TUESDAY AFTERNOON/EVENING. ONE TREND THAT SEEMS TO
PERSIST OVER THE PAST FEW MODEL RUNS IS A LOWER QPF TYPE
EVENT...FOR BOTH THE GFS AND THE ECMWF...SO HEAVY SNOW IS
LESS LIKELY.
UPPER LEVEL RIDGING BEGINS PUSHING INTO THE REGION WEDNESDAY
NIGHT INTO THURSDAY MORNING. THE RIDGE DOMINATES THE PATTERN
THROUGH THE REMAINDER OF THE PERIOD...KEEPING GENERALLY DRY
CONDITIONS IN PLACE. THERE DO APPEAR TO BE SEVERAL SHORTWAVES
SLIPPING THROUGH THE FLOW HOWEVER...BRINGING PERIODIC POTENTIAL
FOR MOUNTAIN SHOWERS THROUGH THE PERIOD. A STRONGER WAVE PUSHES
INTO THE REGION SATURDAY...WITH PLENTY OF ASSOCIATED PACIFIC
MOISTURE...WHICH SHOULD BRING SHOWERS ACROSS THE REGION. AAG
&&
.AVIATION...
VFR CONDITIONS PERSIST ACROSS MUCH OF THE REGION THIS
MORNING. IFR CEILINGS AND VISIBILITIES WITH LOW CLOUDS AND PATCHY
FOG ARE POISED JUST NORTHEAST OF THE REGION...AND ARE ANTICIPATED
TO SPREAD INTO SOUTHEAST MONTANA THIS MORNING. LIGHT FREEZING
DRIZZLE IS POSSIBLE AT KMLS AND KBHK UNTIL THE CLOUD LAYER DEEPENS
ENOUGH FOR LIGHT SNOW TO BEGIN BY SATURDAY AFTERNOON. EXPECT TO
SEE CLOUD DECK DEVELOPING AND CONDITIONS LOWERING TO SUB- VFR
LEVELS ACROSS THE AREA THIS AFTERNOON AS LIGHT SNOW DEVELOPS. AAG
&&
.PRELIMINARY POINT TEMP/POPS...
TDY SUN MON TUE WED THU FRI
-------------------------------------------------------
BIL 038 014/032 029/045 028/028 012/028 021/043 033/053
6/S 71/E 23/W 55/J 42/J 21/B 11/N
LVM 040 016/038 032/047 034/040 020/035 026/046 034/055
2/O 51/N 33/W 46/J 42/J 21/B 11/N
HDN 036 010/030 024/043 024/028 006/026 015/041 026/051
6/S 61/B 23/W 55/J 41/B 21/B 11/B
MLS 032 007/024 020/035 018/019 000/019 009/035 023/047
9/S 61/B 24/J 55/J 21/B 11/B 11/B
4BQ 042 009/028 022/043 025/029 007/023 016/042 027/055
3/O 71/B 23/W 34/J 41/B 11/B 11/B
BHK 027 003/020 015/033 016/019 901/014 005/034 022/046
8/S 81/B 24/J 54/J 21/B 11/B 11/B
SHR 040 011/029 021/044 025/036 009/030 015/042 026/053
1/N 31/B 22/W 25/J 52/J 21/B 11/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1030 AM EST SAT JAN 31 2015
.SYNOPSIS...HIGH PRESSURE CONTINUES TO BUILD OVER THE REGION TODAY.
THE CENTER OF THE HIGH MOVES OFFSHORE TONIGHT AHEAD OF A LOW
PRESSURE SYSTEM THAT MOVES INTO THE MID-ATLANTIC MONDAY MORNING. THE
TRAILING COLD FRONT PUSHES EAST OF THE CAROLINAS MONDAY...FOLLOWED
BY HIGH PRESSURE AGAIN FOR THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /TODAY AND TONIGHT/...
AS OF 1030 AM SATURDAY...
LITTLE CHANGE TO THE FORECAST THIS MORNING. STRONG MID-LEVEL
RIDGING AND SURFACE HIGH PRESSURE ENCOMPASSES MOST OF THE
SOUTHEASTERN QUARTER OF THE CONUS...WITH PW VALUES DOWN TO LESS THAN
0.15" ON MANY OF THE REGIONAL RAOBS. MID/HIGH CLOUDS EXPANDING
ACROSS THE MID/LOWER MISSISSIPPI VALLEY SHOULD REMAIN MOSTLY WEST OF
THE AREA DURING THE DAY TODAY...WITH JUST A FEW PATCHES OF CIRRUS
OVER CENTRAL NC. FORECAST HIGHS ARE IN LINE WITH THE OBSERVED
MORNING 1000-850MB THICKNESS (1272M AT KGSO) AND SLIGHT RECOVERY
OVER THE SOUTHWEST AS THE SURFACE HIGH SHIFTS SOUTHEAST THIS
AFTERNOON. MID 40S NORTHEAST TO AROUND 50 SOUTHWEST. -BLS
TEMPERATURES SHOULD FALL SOMEWHAT QUICKLY THIS EVENING THEN TEND TO
STABILIZE AS CLOUDS MOVE IN. LOWS TONIGHT 25 TO 30 NEAR AND EAST OF
INTERSTATE 95 AND AROUND 30 ELSEWHERE. MINIMUM RELATIVE HUMIDITIES
TODAY COULD FALL TO NEAR 15 PERCENT BASED ON THE EXPECTED SURFACE
DEW POINTS...BUT WINDS WILL BE MUCH LIGHTER COMPARED TO FRIDAY AND
BY THE TIME DEW POINTS WOULD FALL TO THOSE LEVELS THE FREQUENCY OF
ANY MODEST GUSTS SHOULD BE MUCH LOWER.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 AM SATURDAY...
SUNDAY: MINOR MID-LEVEL IMPULSES EMANATING FROM THE UPPER
TROUGH/CLOSED LOW OVER THE SOUTHWEST US WILL EJECT EASTWARD AND MOVE
THROUGH THE AREA IN ADVANCE OF THE NORTHERN STREAM TROUGH AMPLIFYING
OVER THE CENTRAL PLAINS. ASSOCIATED WEAK DPVA WILL RESULT IN
EXTENSIVE MID/HIGH LEVEL CLOUDINESS OVER THE AREA ON
SUNDAY...HOWEVER GRADUAL MOISTENING OF AN INITIALLY DRY ~10KFT SUB-
CLOUD LAYER LEFT(REMAINS OF THE MODERATING CP AIRMASS)WILL KEEP IT
DRY ACROSS MUCH OF CENTRAL NC DURING THE DAYLIGHT HOURS. THE
EXCEPTION WILL BE ACROSS THE FAR WESTERN ZONES WHERE A FEW SHOWERS
COULD DEVELOP LATE IN THE AFTERNOON AS THE WARM MOIST CONVEYOR FEED
BEGINS TO PUSH EAST OF THE MOUNTAINS. HIGHS SUNDAY IN THE LOWER 50S
NORTH TO MID 50S SOUTH.
SUNDAY NIGHT: AFOREMENTIONED NORTHERN STREAM TROUGH WILL CONTINUE TO
PROGRESS EASTWARD...REACHING THE SOUTHERN/CENTRAL APPALACHIANS BY
DAYBREAK MONDAY. DEEPENING SURFACE LOW....MOVING EASTWARD ALONG THE
LEADING EDGE OF THE ASSOCIATED 180-200 METER 500MB HEIGHT FALLS...
WILL TRACK ACROSS THE SOUTHERN OHIO VALLEY AND THROUGH THE
VIRGINIAS DURING THE PREDAWN HOURS...DRAGGING A SFC COLD FRONT INTO
THE NC FOOTHILLS. STRONG DEEP MOISTURE TRANSPORT IN ADVANCE OF THE
FRONT...WITHIN THE STRENGTHENING 60-65KT SOUTHERLY LLJ WILL SUPPORT
A 4-6 HOUR WINDOW OF CATEGORICAL POPS ACROSS THE AREA SUNDAY NIGHT.
QPF AMOUNTS LOOK TO BE IN THE 0.25-0.50" RANGE...LIMITED BY THE
INTRUSION OF A MID-LEVEL SLOT RACING IN FROM THE WEST. HAVE NO PLANS
TO INCLUDE ANY THUNDER AT THIS TIME AS MODELS CONTINUE TO SHOW
MODEST MID-LEVEL LAPSE RATES (6.5-6.8 C/KM)WITH LESS THAN <200 J/KG
OF MUCAPE ACROSS THE AREA.
EXPECT A NON-DIURNAL TEMP TREND SUNDAY NIGHT...WITH LOWS OCCURRING
BEFORE MIDNIGHT...WITH TEMPERATURES THEN WARMING OVERNIGHT OWING TO
STRONG WAA. LOWS SUNDAY NIGHT IN THE MID 40S NORTHWEST TO LOWER 50S
SOUTH.
MONDAY AND MONDAY NIGHT: AGGRESSIVE MID-LEVEL DRY AIR INTRUSION WILL
OVERTAKE THE AREA FROM THE WEST BETWEEN 12 TO 18Z MONDAY IN ADVANCE
OF THE PASSAGE OF THE NORTHERN STREAM TROUGH PASSAGE MONDAY
AFTERNOON. THIS WILL BRING AN ABRUPT END TO PRECIP ACROSS THE AREA
MONDAY MORNING...WITH RAIN/SHOWERS EXITING THE COASTAL PLAIN DURING
THE MID TO LATE MORNING. EQUALLY IMPRESSIVE WILL BE STRONG POST-
FRONTAL DRY COLD AIR ADVECTION REGIME...WITH BREEZY/BLUSTERY
CONDITIONS AS BUFR SOUNDINGS INDICATING 38-40KTS AT THE TOP OF THE
MIXED LAYER(SIMILAR TO IF NOT STRONGER THAN THE GUSTS WE HAD
YESTERDAY). LOOK FOR TEMPERATURES FALLING THROUGH THE AFTERNOON AS
YET ANOTHER CP AIRMASS BUILDS INTO THE AREA MONDAY NIGHT AND INTO
THE DAY ON TUESDAY. MORNING HIGHS RANGING FROM MID UPPER 40S
NORTHWEST TO MID 50S SOUTHEAST. IF PROJECTED LOW-LEVEL THICKNESSES
AOA 1270M VERIFY AND WE DECOUPLE AS MODELS SUGGEST...EXPECT LOWS
TUESDAY MORNING IN THE LOWER 20S...WITH UPPER TEENS POSSIBLE IN THE
TYPICALLY COLDER LOCATIONS.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 AM SATURDAY...
BOTH THE ECMWF AND THE GFS PASS A MID-LEVEL SHORTWAVE THROUGH
CENTRAL NORTH CAROLINA TUESDAY AS A BROAD...PROGRESSIVE TROUGH ALOFT
MOVES THROUGH. HOWEVER...WITH SURFACE HIGH PRESSURE IN PLACE AND
EXTENDING ACROSS THE GULF A PERIOD OF PARTLY TO POSSIBLY MOSTLY
CLOUDY SKIES SHOULD ONLY ACCOMPANY THE SHORTWAVE. AFTER EXPECTED
BRIEF CLEARING BEHIND THE MID-LEVEL WAVE...IN THE FAST AND SLOWLY
BACKING FLOW ALOFT BOTH THE ECMWF AND THE GFS FORECAST INCREASING
UPPER-LEVEL MOISTURE WEDNESDAY INTO WEDNESDAY NIGHT WITH A COLD
FRONT MOVING THROUGH WEDNESDAY NIGHT. BOTH THE GFS AND ECMWF ARE DRY
INTO THE OVERNIGHT HOURS OF WEDNESDAY WITH SURFACE HIGH PRESSURE
AHEAD OF THE COLD FRONT EXTENDING OVER THE GULF COAST AND LIMITING
LOW-LEVEL MOISTURE RETURN. FOR THIS FORECAST...WILL HAVE DRY
CONDITIONS TUESDAY INTO THE OVERNIGHT HOURS OF WEDNESDAY. MEX MOS
AND ECMWF MOS GUIDANCE POPS ARE BELOW CLIMATOLOGY DURING THIS PERIOD.
GUIDANCE DIFFERENCES ARE FAIRLY OBVIOUS BY LATE WEDNESDAY NIGHT.
MUCH WILL DEPEND ON HOW DEEP THE UPPER TROUGH MOVING THROUGH
SOUTHERN CANADA ENDS UP BEING DURING THE MIDDLE OF THE WEEK. THE
ECMWF HAS BEEN CONSISTENT OVER THE LAST COUPLE OF RUNS OR SO WITH A
DEEPER UPPER TROUGH EXTENDING THROUGH THE GREAT LAKES INTO THE OHIO
VALLEY. THIS SUPPRESSES THE TRACK OF AN UPPER LOW FORECAST BY BOTH
THE GFS AND THE ECMWF TO DEVELOP OVER OLD MEXICO...KEEPING DEEPER
MOISTURE TO OUR SOUTH AND RESULTING IN DRY CONDITIONS FOR CENTRAL
NORTH CAROLINA THROUGH THE END OF THE WEEK. THE GFS...ALSO
CONSISTENT WITH ITSELF...IS NOTICEABLY LESS AMPLIFIED WITH THE
CANADIAN UPPER TROUGH SUCH THAT THE WEAKENING UPPER LOW IS ABLE TO
MOVE TOWARD THE CAROLINAS BY THURSDAY ALONG WITH MORE MOISTURE. THE
GFS FORECASTS PRECIPITATION OVER CENTRAL NORTH CAROLINA BY 12Z
THURSDAY WHICH...IF IT OCCURS...WOULD BE LIQUID AS GFS PARTIAL
THICKNESSES ARE WELL INTO THE RAIN REGIME AT THAT TIME.
DUE TO THE GUIDANCE UNCERTAINTY...THE PRUDENT COURSE APPEARS TO BE
MAINTAINING CONSISTENCY WITH THE ONGOING FORECAST...A CHANCE OF RAIN
IN CENTRAL NORTH CAROLINA OVERNIGHT WEDNESDAY INTO THURSDAY WITH
CHANCES LOWEST AND BASICALLY NEAR SLIGHT IN THE TRIAD TO HIGHER
CHANCES ALONG AND EAST OF A LINE FROM ABOUT KMEB TO KRWI. IF THE GFS
VERIFIES EXACTLY THERE WOULD BE CONCERN ABOUT PRECIPITATION TYPE IN
THE LINGERING MOISTURE BY THURSDAY NIGHT...BUT A DRY ECMWF WITH NEAR
SOUTHEAST CONUS LOW PRESSURE MOVING OFFSHORE AND A DRY PREVIOUS
FORECAST WILL RESULT IN A DRY CURRENT FORECAST THURSDAY NIGHT
THROUGH FRIDAY NIGHT...THOUGH TURNING CHILLY AT THE END OF THE WEEK.
THE WARMEST DAY OF THE PERIOD SHOULD BE WEDNESDAY. 1000-850MB
THICKNESSES WOULD SUGGEST HIGHS AT LEAST IN THE MID TO UPPER 50S...
FAIRLY COINCIDENT WITH THE MEX AND MEE MOS GUIDANCE...BUT WILL LEAN
ABOUT A CATEGORY COOLER TOWARD THE HPC GUIDANCE FOR HIGHS IN THE
LOWER TO MID 50S DUE TO THE ANTICIPATED PRESENCE OF AT LEAST SOME
UPPER-LEVEL CLOUD COVER. THICKNESSES COOL AT THE END OF THE WEEK
AND...DESPITE DIFFERENCES IN OTHER DETAILS...1000-850MB
THICKNESSES...AND HPC AND MUCH OF THE MOS GUIDANCE...KEEP HIGHS ONLY
IN THE MID 30S TO LOWER 40S FRIDAY.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 630 AM SATURDAY...
VFR CONDITIONS CONTINUE FOR THE 12Z VALID TAF PERIOD. SATELLITE
IMAGES STILL SHOWED A FEW JET-STREAK CIRRUS IN CENTRAL NORTH
CAROLINA AROUND DAYBREAK...AND DURING THE DAY TODAY AND THROUGH THE
OVERNIGHT HOURS HIGH- AND MID-LEVEL CLOUDS WILL GRADUALLY MOVE IN
FROM THE WEST. EXPECT MORE OF THE MID-LEVEL CLOUDS TO APPEAR IN
CENTRAL NORTH CAROLINA TONIGHT...FROM AROUND 03Z AND LATER. FORECAST
SOUNDINGS ESPECIALLY FROM THE GFS SUGGEST A FEW WIND GUSTS INTO THE
TEENS KNOTS WITH INITIAL MIXING THIS MORNING...BUT THE TREND OF ANY
GUSTINESS SHOULD DIMINISH BY EARLY AFTERNOON AS THE SURFACE HIGH
CONTINUES TO BUILD IN. RAP SOUNDINGS ARE A COUPLE OF KNOTS
LIGHTER...SO IT IS POSSIBLE THAT THE TAFS REFLECT GUSTS IN THE TEENS
KNOTS THAT ARE ON THE HIGHER END OF WHAT MAY OCCUR WITH MIXING THIS
MORNING INTO EARLY AFTERNOON...ESPECIALLY TOWARD THE TRIAD. LIGHT
SOUTH TO SOUTHWEST WIND BY THIS EVENING.
BEYOND THE 12Z VALID TAF PERIOD...VFR SUNDAY...WITH AN INCREASING
POSSIBILITY OF MVFR CLOUDS DURING THE AFTERNOON...THEN SUB-VFR
CONDITIONS AND AREAS OF RAIN LIKELY OVERNIGHT SUNDAY AHEAD OF A COLD
FRONT THAT WILL MOVE THROUGH CENTRAL NORTH CAROLINA EARLY MONDAY.
AHEAD OF THE COLD FRONT SUNDAY NIGHT...WINDS ALOFT WILL INCREASE TO
SOUTHWEST AOA 50KT BY 2500FT. VFR CONDITIONS RETURN BY MONDAY
AFTERNOON WITH GUSTY WEST-NORTHWEST AND NORTHWEST SURFACE WINDS. VFR
CONDITIONS SHOULD THEN CONTINUE THROUGH WEDNESDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...DJF/BLS
SHORT TERM...CBL
LONG TERM...DJF
AVIATION...DJF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
631 AM EST SAT JAN 31 2015
.SYNOPSIS...HIGH PRESSURE CONTINUES TO BUILD OVER THE REGION TODAY.
THE CENTER OF THE HIGH MOVES OFFSHORE TONIGHT AHEAD OF A LOW
PRESSURE SYSTEM THAT MOVES INTO THE MID-ATLANTIC MONDAY MORNING. THE
TRAILING COLD FRONT PUSHES EAST OF THE CAROLINAS MONDAY...FOLLOWED
BY HIGH PRESSURE AGAIN FOR THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /TODAY AND TONIGHT/...
AS OF 115 AM SATURDAY...
ASIDE FROM SOME JET-STREAK CIRRUS OVER PART OF CENTRAL NORTH
CAROLINA ON THE LATEST IR SATELLITE IMAGES...CLEAR CONDITIONS WERE
IN PLACE OVER CENTRAL NORTH CAROLINA. THE JET ALOFT IS FORECAST BY
THE GFS AND NAM TO MOVE NORTHEAST AND OUT OF CENTRAL NORTH CAROLINA
DURING THE DAY...ALTHOUGH A FLAT RIDGE AXIS ALOFT WILL APPROACH THE
STATE TONIGHT WITH A GRADUAL INCREASE IN HIGH CLOUDS AND MAYBE EVEN
MORE MID-LEVEL CLOUDS IN THE 12000FT TO 15000FT RANGE OVERNIGHT
BASED ON THE MOISTURE PROFILES FROM BOTH THE NAM AND GFS BUFR
SOUNDINGS. K INDICES ARE NEGATIVE UNTIL LATE TONIGHT IN THE
INTERSTATE 85 CORRIDOR WHERE THE CLOUD BASES MAY BE A LITTLE LOWER
RELATIVE TO THE REST OF CENTRAL NORTH CAROLINA...BUT THE AIR MASS
BELOW 700MB REMAINS DRY AT LEAST THROUGH TONIGHT. THE CANADIAN CLOUD
COVER MODEL WHICH TENDS TO DO PRETTY WELL WITH THE ONSET AND
COVERAGE OF HIGHER CLOUDS INCREASES THE COVERAGE OF THOSE CLOUDS
GRADUALLY THIS AFTERNOON THROUGH TONIGHT WITH AREAS FROM KFAY TO
KRWI AND EAST TAKING LONGER TO GET AT LEAST BROKEN COVERAGE.
GFS BUFR SOUNDINGS ARE SLIGHTLY HIGHER THAN NAM BUFR SOUNDINGS WITH
REGARD TO THE POTENTIAL FOR A FEW WIND GUSTS IN THE TEENS KNOTS THIS
MORNING. BASED ON SOME STIRRING OF THE WINDS CONTINUING EARLY THIS
MORNING WILL LEAN TOWARD THE GFS AND ANTICIPATE A FEW WIND GUSTS IN
THE TEENS KNOTS THIS MORNING BEFORE ANY GUSTINESS SHOULD DIMINISH
INTO THE AFTERNOON AS THE SURFACE HIGH CONTINUES TO BUILD IN. WINDS
WILL BECOME LIGHT SOUTH TO SOUTHWEST BY THIS EVENING. UNDER GOOD
SUNSHINE...1000-850MB THICKNESSES AND A BLEND OF THE MAV AND MET MOS
GUIDANCE SUGGEST HIGHS FROM THE MID 40S TO LOWER 50S...HIGHEST
SOUTHWEST WHERE THE THICKNESSES WILL BE GREATER AND WINDS BECOME
WEST TO SOUTHWEST SOONER. TEMPERATURES SHOULD FALL SOMEWHAT QUICKLY
THIS EVENING THEN TEND TO STABILIZE AS CLOUDS MOVE IN. LOWS TONIGHT
25 TO 30 NEAR AND EAST OF INTERSTATE 95 AND AROUND 30 ELSEWHERE.
MINIMUM RELATIVE HUMIDITIES TODAY COULD FALL TO NEAR 15 PERCENT
BASED ON THE EXPECTED SURFACE DEW POINTS...BUT WINDS WILL BE MUCH
LIGHTER COMPARED TO FRIDAY AND BY THE TIME DEW POINTS WOULD FALL TO
THOSE LEVELS THE FREQUENCY OF ANY MODEST GUSTS SHOULD BE MUCH LOWER.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 AM SATURDAY...
SUNDAY: MINOR MID-LEVEL IMPULSES EMANATING FROM THE UPPER
TROUGH/CLOSED LOW OVER THE SOUTHWEST US WILL EJECT EASTWARD AND MOVE
THROUGH THE AREA IN ADVANCE OF THE NORTHERN STREAM TROUGH AMPLIFYING
OVER THE CENTRAL PLAINS. ASSOCIATED WEAK DPVA WILL RESULT IN
EXTENSIVE MID/HIGH LEVEL CLOUDINESS OVER THE AREA ON
SUNDAY...HOWEVER GRADUAL MOISTENING OF AN INITIALLY DRY ~10KFT SUB-
CLOUD LAYER LEFT(REMAINS OF THE MODERATING CP AIRMASS)WILL KEEP IT
DRY ACROSS MUCH OF CENTRAL NC DURING THE DAYLIGHT HOURS. THE
EXCEPTION WILL BE ACROSS THE FAR WESTERN ZONES WHERE A FEW SHOWERS
COULD DEVELOP LATE IN THE AFTERNOON AS THE WARM MOIST CONVEYOR FEED
BEGINS TO PUSH EAST OF THE MOUNTAINS. HIGHS SUNDAY IN THE LOWER 50S
NORTH TO MID 50S SOUTH.
SUNDAY NIGHT: AFOREMENTIONED NORTHERN STREAM TROUGH WILL CONTINUE TO
PROGRESS EASTWARD...REACHING THE SOUTHERN/CENTRAL APPALACHIANS BY
DAYBREAK MONDAY. DEEPENING SURFACE LOW....MOVING EASTWARD ALONG THE
LEADING EDGE OF THE ASSOCIATED 180-200 METER 500MB HEIGHT FALLS...
WILL TRACK ACROSS THE SOUTHERN OHIO VALLEY AND THROUGH THE
VIRGINIAS DURING THE PREDAWN HOURS...DRAGGING A SFC COLD FRONT INTO
THE NC FOOTHILLS. STRONG DEEP MOISTURE TRANSPORT IN ADVANCE OF THE
FRONT...WITHIN THE STRENGTHENING 60-65KT SOUTHERLY LLJ WILL SUPPORT
A 4-6 HOUR WINDOW OF CATEGORICAL POPS ACROSS THE AREA SUNDAY NIGHT.
QPF AMOUNTS LOOK TO BE IN THE 0.25-0.50" RANGE...LIMITED BY THE
INTRUSION OF A MID-LEVEL SLOT RACING IN FROM THE WEST. HAVE NO PLANS
TO INCLUDE ANY THUNDER AT THIS TIME AS MODELS CONTINUE TO SHOW
MODEST MID-LEVEL LAPSE RATES (6.5-6.8 C/KM)WITH LESS THAN <200 J/KG
OF MUCAPE ACROSS THE AREA.
EXPECT A NON-DIURNAL TEMP TREND SUNDAY NIGHT...WITH LOWS OCCURRING
BEFORE MIDNIGHT...WITH TEMPERATURES THEN WARMING OVERNIGHT OWING TO
STRONG WAA. LOWS SUNDAY NIGHT IN THE MID 40S NORTHWEST TO LOWER 50S
SOUTH.
MONDAY AND MONDAY NIGHT: AGGRESSIVE MID-LEVEL DRY AIR INTRUSION WILL
OVERTAKE THE AREA FROM THE WEST BETWEEN 12 TO 18Z MONDAY IN ADVANCE
OF THE PASSAGE OF THE NORTHERN STREAM TROUGH PASSAGE MONDAY
AFTERNOON. THIS WILL BRING AN ABRUPT END TO PRECIP ACROSS THE AREA
MONDAY MORNING...WITH RAIN/SHOWERS EXITING THE COASTAL PLAIN DURING
THE MID TO LATE MORNING. EQUALLY IMPRESSIVE WILL BE STRONG POST-
FRONTAL DRY COLD AIR ADVECTION REGIME...WITH BREEZY/BLUSTERY
CONDITIONS AS BUFR SOUNDINGS INDICATING 38-40KTS AT THE TOP OF THE
MIXED LAYER(SIMILAR TO IF NOT STRONGER THAN THE GUSTS WE HAD
YESTERDAY). LOOK FOR TEMPERATURES FALLING THROUGH THE AFTERNOON AS
YET ANOTHER CP AIRMASS BUILDS INTO THE AREA MONDAY NIGHT AND INTO
THE DAY ON TUESDAY. MORNING HIGHS RANGING FROM MID UPPER 40S
NORTHWEST TO MID 50S SOUTHEAST. IF PROJECTED LOW-LEVEL THICKNESSES
AOA 1270M VERIFY AND WE DECOUPLE AS MODELS SUGGEST...EXPECT LOWS
TUESDAY MORNING IN THE LOWER 20S...WITH UPPER TEENS POSSIBLE IN THE
TYPICALLY COLDER LOCATIONS.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 AM SATURDAY...
BOTH THE ECMWF AND THE GFS PASS A MID-LEVEL SHORTWAVE THROUGH
CENTRAL NORTH CAROLINA TUESDAY AS A BROAD...PROGRESSIVE TROUGH ALOFT
MOVES THROUGH. HOWEVER...WITH SURFACE HIGH PRESSURE IN PLACE AND
EXTENDING ACROSS THE GULF A PERIOD OF PARTLY TO POSSIBLY MOSTLY
CLOUDY SKIES SHOULD ONLY ACCOMPANY THE SHORTWAVE. AFTER EXPECTED
BRIEF CLEARING BEHIND THE MID-LEVEL WAVE...IN THE FAST AND SLOWLY
BACKING FLOW ALOFT BOTH THE ECMWF AND THE GFS FORECAST INCREASING
UPPER-LEVEL MOISTURE WEDNESDAY INTO WEDNESDAY NIGHT WITH A COLD
FRONT MOVING THROUGH WEDNESDAY NIGHT. BOTH THE GFS AND ECMWF ARE DRY
INTO THE OVERNIGHT HOURS OF WEDNESDAY WITH SURFACE HIGH PRESSURE
AHEAD OF THE COLD FRONT EXTENDING OVER THE GULF COAST AND LIMITING
LOW-LEVEL MOISTURE RETURN. FOR THIS FORECAST...WILL HAVE DRY
CONDITIONS TUESDAY INTO THE OVERNIGHT HOURS OF WEDNESDAY. MEX MOS
AND ECMWF MOS GUIDANCE POPS ARE BELOW CLIMATOLOGY DURING THIS PERIOD.
GUIDANCE DIFFERENCES ARE FAIRLY OBVIOUS BY LATE WEDNESDAY NIGHT.
MUCH WILL DEPEND ON HOW DEEP THE UPPER TROUGH MOVING THROUGH
SOUTHERN CANADA ENDS UP BEING DURING THE MIDDLE OF THE WEEK. THE
ECMWF HAS BEEN CONSISTENT OVER THE LAST COUPLE OF RUNS OR SO WITH A
DEEPER UPPER TROUGH EXTENDING THROUGH THE GREAT LAKES INTO THE OHIO
VALLEY. THIS SUPPRESSES THE TRACK OF AN UPPER LOW FORECAST BY BOTH
THE GFS AND THE ECMWF TO DEVELOP OVER OLD MEXICO...KEEPING DEEPER
MOISTURE TO OUR SOUTH AND RESULTING IN DRY CONDITIONS FOR CENTRAL
NORTH CAROLINA THROUGH THE END OF THE WEEK. THE GFS...ALSO
CONSISTENT WITH ITSELF...IS NOTICEABLY LESS AMPLIFIED WITH THE
CANADIAN UPPER TROUGH SUCH THAT THE WEAKENING UPPER LOW IS ABLE TO
MOVE TOWARD THE CAROLINAS BY THURSDAY ALONG WITH MORE MOISTURE. THE
GFS FORECASTS PRECIPITATION OVER CENTRAL NORTH CAROLINA BY 12Z
THURSDAY WHICH...IF IT OCCURS...WOULD BE LIQUID AS GFS PARTIAL
THICKNESSES ARE WELL INTO THE RAIN REGIME AT THAT TIME.
DUE TO THE GUIDANCE UNCERTAINTY...THE PRUDENT COURSE APPEARS TO BE
MAINTAINING CONSISTENCY WITH THE ONGOING FORECAST...A CHANCE OF RAIN
IN CENTRAL NORTH CAROLINA OVERNIGHT WEDNESDAY INTO THURSDAY WITH
CHANCES LOWEST AND BASICALLY NEAR SLIGHT IN THE TRIAD TO HIGHER
CHANCES ALONG AND EAST OF A LINE FROM ABOUT KMEB TO KRWI. IF THE GFS
VERIFIES EXACTLY THERE WOULD BE CONCERN ABOUT PRECIPITATION TYPE IN
THE LINGERING MOISTURE BY THURSDAY NIGHT...BUT A DRY ECMWF WITH NEAR
SOUTHEAST CONUS LOW PRESSURE MOVING OFFSHORE AND A DRY PREVIOUS
FORECAST WILL RESULT IN A DRY CURRENT FORECAST THURSDAY NIGHT
THROUGH FRIDAY NIGHT...THOUGH TURNING CHILLY AT THE END OF THE WEEK.
THE WARMEST DAY OF THE PERIOD SHOULD BE WEDNESDAY. 1000-850MB
THICKNESSES WOULD SUGGEST HIGHS AT LEAST IN THE MID TO UPPER 50S...
FAIRLY COINCIDENT WITH THE MEX AND MEE MOS GUIDANCE...BUT WILL LEAN
ABOUT A CATEGORY COOLER TOWARD THE HPC GUIDANCE FOR HIGHS IN THE
LOWER TO MID 50S DUE TO THE ANTICIPATED PRESENCE OF AT LEAST SOME
UPPER-LEVEL CLOUD COVER. THICKNESSES COOL AT THE END OF THE WEEK
AND...DESPITE DIFFERENCES IN OTHER DETAILS...1000-850MB
THICKNESSES...AND HPC AND MUCH OF THE MOS GUIDANCE...KEEP HIGHS ONLY
IN THE MID 30S TO LOWER 40S FRIDAY.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 630 AM SATURDAY...
VFR CONDITIONS CONTINUE FOR THE 12Z VALID TAF PERIOD. SATELLITE
IMAGES STILL SHOWED A FEW JET-STREAK CIRRUS IN CENTRAL NORTH
CAROLINA AROUND DAYBREAK...AND DURING THE DAY TODAY AND THROUGH THE
OVERNIGHT HOURS HIGH- AND MID-LEVEL CLOUDS WILL GRADUALLY MOVE IN
FROM THE WEST. EXPECT MORE OF THE MID-LEVEL CLOUDS TO APPEAR IN
CENTRAL NORTH CAROLINA TONIGHT...FROM AROUND 03Z AND LATER. FORECAST
SOUNDINGS ESPECIALLY FROM THE GFS SUGGEST A FEW WIND GUSTS INTO THE
TEENS KNOTS WITH INITIAL MIXING THIS MORNING...BUT THE TREND OF ANY
GUSTINESS SHOULD DIMINISH BY EARLY AFTERNOON AS THE SURFACE HIGH
CONTINUES TO BUILD IN. RAP SOUNDINGS ARE A COUPLE OF KNOTS
LIGHTER...SO IT IS POSSIBLE THAT THE TAFS REFLECT GUSTS IN THE TEENS
KNOTS THAT ARE ON THE HIGHER END OF WHAT MAY OCCUR WITH MIXING THIS
MORNING INTO EARLY AFTERNOON...ESPECIALLY TOWARD THE TRIAD. LIGHT
SOUTH TO SOUTHWEST WIND BY THIS EVENING.
BEYOND THE 12Z VALID TAF PERIOD...VFR SUNDAY...WITH AN INCREASING
POSSIBILITY OF MVFR CLOUDS DURING THE AFTERNOON...THEN SUB-VFR
CONDITIONS AND AREAS OF RAIN LIKELY OVERNIGHT SUNDAY AHEAD OF A COLD
FRONT THAT WILL MOVE THROUGH CENTRAL NORTH CAROLINA EARLY MONDAY.
AHEAD OF THE COLD FRONT SUNDAY NIGHT...WINDS ALOFT WILL INCREASE TO
SOUTHWEST AOA 50KT BY 2500FT. VFR CONDITIONS RETURN BY MONDAY
AFTERNOON WITH GUSTY WEST-NORTHWEST AND NORTHWEST SURFACE WINDS. VFR
CONDITIONS SHOULD THEN CONTINUE THROUGH WEDNESDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...DJF
SHORT TERM...CBL
LONG TERM...DJF
AVIATION...DJF
AREA FORECAST DISCUSSION
NWS BISMARCK ND
951 AM CST SAT JAN 31 2015
.UPDATE...
ISSUED AT 936 AM CST SAT JAN 31 2015
LATEST BUFKIT MODEL ANALYSIS FOR THE NAM SHOW A FAIRLY DEEP
DENDRITIC GROWTH ZONE LATE THIS AFTERNOON AND TONIGHT ACROSS
WESTERN NORTH DAKOTA. WITH SUPERSATURATION WITH RESPECT TO ICE
THE LOWER ATMOSPHERE SHOULD MAXIMIZE ITS POTENTIAL FOR CREATING
SNOW. MODELS STILL HAVE MODEST QPF AMOUNTS. (THE LATEST HRRR QPF
THROUGH 04Z HAS BETWEEN 0.15-0.25). BELIEVE SNOW AMOUNTS OF 3
INCHES OVERALL WITH ISOLATED HIGHER AMOUNTS STILL LOOK GOOD.
CURRENT FORECAST LOOKS ON TRACK.
UPDATE ISSUED AT 637 AM CST SAT JAN 31 2015
NO MAJOR CHANGES TO THE GOING FORECAST. LIGHT SNOW IS DEVELOPING
ACROSS THE NORTHERN TIER COUNTIES THIS MORNING AND WILL SPREAD
SOUTH AND EAST THROUGH THE DAY. DID EXTEND THE MENTION OF FOG
THROUGH 15 UTC ACROSS THE SOUTHWEST AND FAR SOUTH CENTRAL. UPDATED
TEXT WILL BE OUT SHORTLY
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 343 AM CST SAT JAN 31 2015
THE MAIN FOCUS FOR THE SHORT TERM IS ACCUMULATING SNOW TODAY/TONIGHT.
A SHORTWAVE TROUGH CURRENTLY OVER SOUTHERN ALBERTA AND AN INVERTED
SURFACE TROUGH...CURRENTLY CENTERED ACROSS EASTERN MONTANA...WILL
SLOWLY PROPAGATE SOUTHEAST THROUGH THE MORNING HOURS. AS IT DOES
WIDESPREAD SNOW ACROSS SOUTHERN CANADA IS EXPECTED TO CONTINUE TO
DEVELOP AND ENTER NORTHWESTERN NORTH DAKOTA. A DEFORMATION ZONE IS
EXPECTED TO SET UP ACROSS WESTERN NORTH DAKOTA LATER THIS MORNING
AS A SHORTWAVE TROUGH OVER THE FOUR CORNERS INTERACTS WITH THE
ALBERTA SHORTWAVE. 00 UTC MODELS ARE IN GOOD AGREEMENT ON TIMING
AND LOCATION OF THE SNOW. BY 6AM A LIGHT SNOW BAND SHOULD BEGIN
OVERSPREADING NORTHWESTERN NORTH DAKOTA. THIS BAND IS EXPECTED TO
SLIDE SLOWLY SOUTH THROUGH THE DAY. THE ECMWF/NAM/SREF/GFS ALL
HAVE THE HEAVIEST QPF AMOUNTS ACROSS WEST CENTRAL NORTH DAKOTA
DURING THE AFTERNOON HOURS. FOR THE FORECAST WENT WITH A BLEND OF
THE OPERATIONAL MODELS WHICH ENDS UP PRODUCING WIDESPREAD 2 TO 3
INCHES OF SNOW ACROSS WESTERN AND CENTRAL NORTH DAKOTA...WITH
HEAVIEST AMOUNTS WEST OF HIGHWAY 83.
TEMPERATURES WILL CONTINUE TO GRADUALLY FALL THROUGH THE DAY WITH
CLOUDY SKIES LIMITING SOLAR INSULATION AND COLD AIR ADVECTION
CONTINUES IN FULL FORCE. TEMPERATURES WILL LIKELY FALL BELOW ZERO
ACROSS THE JAMES VALLEY TONIGHT. WIND CHILL READINGS WILL NEAR 20
BELOW BY THE EARLY MORNING HOURS.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 343 AM CST SAT JAN 31 2015
MAIN FORECAST HIGHLIGHTS ARE COLD AND UNSETTLED WEATHER THROUGH AT
LEAST MID WEEK WITH A NUMBER OF LIGHT SNOW EVENTS. THEN POSSIBLY A
RETURN TO MORE MILD CONDITIONS AT THE END OF THE EXTENDED PERIOD.
DETERMINISTIC MODELS ARE IN QUITE GOOD AGREEMENT THROUGH MOST OF THE
EXTENDED PERIOD AND USED A MODEL BLEND FOR FORECAST DETAILS.
WE BEGIN THE PERIOD SUNDAY WITH A 1040 MB SURFACE HIGH DROPPING
FROM SOUTHERN CANADA INTO CENTRAL NORTH DAKOTA BY 18 UTC SUNDAY.
LIGHT SNOWS FROM THE EXITING SHORT TERM SYSTEM SHOULD BE ALL BUT OUT
OF THE SOUTHERN CWA BY 18 UTC...BUT DID INCLUDE A SLIGHT CHANCE OF
LIGHT SNOW WITH OVER THE FAR SOUTH CENTRAL AS REMNANTS MOVE OUT OF
THE FORECAST AREA SUNDAY MORNING. OTHERWISE DRY BUT COLD SUNDAY.
WIND CHILL HIGHLIGHTS MAY BE NEEDED SUNDAY MORNING IF CURRENT TRENDS
HOLD...OVER THE TURTLE MOUNTAINS INTO THE JAMES RIVER VALLEY.
AS THE SURFACE HIGH SLIDES SOUTHEAST SUNDAY NIGHT WARM ADVECTION
RETURNS TO WESTERN NORTH DAKOTA. BY MONDAY MORNING...UPPER LEVEL
FORCING WITH A 120KT JET INDUCES A SURFACE LOW PRESSURE CENTER OVER
SOUTHEAST MONTANA THAT TRACKS SOUTHEAST ACROSS INTO CENTRAL SOUTH
DAKOTA. THE GFS IS THE WEAKEST AND FARTHEST SOUTH WITH THE SURFACE
LOW AND BRINGS VERY LIGHT SNOW AMOUNTS INTO THE FAR SOUTHWEST. ALL
OTHER DETERMINISTIC MODELS TRACK THE SURFACE LOW IN A FAVORED
POSITION TO BRING LIGHT SNOWS TO WESTERN AND SOUTH CENTRAL NORTH
DAKOTA. AMOUNTS HERE ARE DEFINITELY SUB-ADVISORY CRITERIA AND AS A
FIRST GUESS HAVE GONE WITH HALF INCH TO ONE INCH AMOUNTS ALONG AND
SOUTH OF LAKE SAKAKAWEA AND THE MISSOURI RIVER...WITH LITTLE OR NO
ACCUMULATIONS NORTH AND EAST OF HERE. TAKING THE GFS OUT OF THE
BLEND WOULD YIELD HIGHER AMOUNTS...MAYBE 1-2 INCHES IN THIS SAME
GENERAL AREA...SO WILL HAVE TO MONITOR...BUT STILL SUB-ADVISORY
SNOWS.
ANOTHER IMPULSE QUICKLY RACES INTO THE AREA ALREADY BY LATE MONDAY
NIGHT. THIS TIME THERE IS A TIGHTER BAROCLINIC ZONE THAT IMPULSES
WILL INTERACT WITH OVER THE SAME GENERAL AREA OF WESTERN INTO SOUTH
CENTRAL NORTH DAKOTA. THERE ARE SOME MODEL DIFFERENCES IN THE
PLACEMENT OF THE SURFACE AND UPPER LEVEL FEATURES BUT MODELS ARE
CURRENTLY IN GOOD AGREEMENT IN BRINGING ANOTHER SWATH OF LIGHT SNOWS
OVER WESTERN AND SOUTH CENTRAL NORTH DAKOTA...WITH THE TURTLE
MOUNTAINS AREA ONCE AGAIN SEEING THE THE SMALLEST CHANCES OF
ACCUMULATING SNOWS. IN GENERAL...WE ARE TALKING SUB-ADVISORY
CRITERIA SNOWS OF 1 TO 3 INCHES LATE MONDAY NIGHT THROUGH TUESDAY.
THE GFS IS A LITTLE MORE IMPRESSIVE WITH THE SURFACE LOW AND HINTS
AT SOME INDIRECT JET CIRCULATION BETWEEN THE TWO STRONG JETLETS OVER
THE NORTHERN PLAINS. THUS WILL NEED TO KEEP AN EYE ON THIS SYSTEM AS
WELL.
ONE LAST IMPULSE KEEPS A LINGERING CHANCE OF LIGHT SNOW OVER THE
SOUTHWEST THROUGH TUESDAY EVENING...THEN ARCTIC HIGH PRESSURE DROPS
INTO THE AREA AND PUTS AN END TO THE SNOW CHANCES BY LATE TUESDAY
NIGHT. HOWEVER...WIND CHILLS WILL LIKELY AGAIN BE AN ISSUE OVER
MAINLY THE NORTHERN THIRD OF THE FORECAST AREA.
WE THEN WARM UP QUICKLY THURSDAY AS THE ARCTIC HIGH DIVES QUICKLY
SOUTH AND EAST. WE TRANSITION TO A MORE QUASI-ZONAL FLOW WITH
SHORTWAVES TRAVERSING THE AREA FRIDAY AND SATURDAY. WITH THE WARMER
TEMPERATURES WE MAY NEED TO WORRY MORE ABOUT POSSIBLE MIXED
PRECIPITATION BUT TEMPERATURES WILL BE BACK ABOVE NORMAL.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 637 AM CST SAT JAN 31 2015
MVFR TO IFR CIGS WILL CONTINUE OVER THE AREA THROUGH THE FORECAST
PERIOD. SNOW HAS DEVELOPED IN THE FAR NORTH AND WILL SPREAD SOUTH
AND EAST ACROSS ALL AERODROMES THROUGH THE DAY. AREAS OF DENSE FOG
SOUTHWEST INCLUDING KDIK SHOULD LIFT BY AROUND 15 UTC.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...WAA
SHORT TERM...AJ
LONG TERM...TWH
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS TUCSON AZ
235 PM MST SAT JAN 31 2015
.SYNOPSIS...A STORM SYSTEM CONTINUED TO BRING VALLEY RAIN AND
MOUNTAINTOP SNOW THIS AFTERNOON...BUT THIS ACTIVITY WILL DIMINISH
THIS EVENING AND TONIGHT. MINOR FLOODING AND ELEVATED FLOWS IN
WASHES AND STREAMS WILL REMAIN A CONCERN THROUGH TONIGHT. THE MOST
SIGNIFICANT SNOWFALL WILL BE ACROSS THE HIGHEST PEAKS...ABOVE 7500
FEET. EXPECT MUCH COOLER DAYTIME TEMPERATURES THIS WEEKEND. DRY
CONDITIONS WITH A WARMING TREND WILL THEN OCCUR DURING THE UPCOMING
WEEK.
&&
.DISCUSSION...A STORM SYSTEM TRACKING SOUTHEAST OVER NORTHERN BAJA
INTO NORTHWEST MEXICO WILL CONTINUE TO BRING PERIODS OF RAIN AND
HIGH ELEVATION SNOW TO SOUTHEAST ARIZONA THROUGH EARLY SUNDAY.
LATEST MODELS SUGGESTED THAT MUCH OF THIS PRECIPITATION WILL BE
DIMINISHING THIS EVENING INTO TONIGHT AS THE SYSTEM TRACKS FARTHER
SOUTHEAST OF THE AREA. THE HRRR SOLUTIONS INDICATE THAT THE
CONVECTIVE SHOWERS DEVELOPING EARLY THIS AFTERNOON WILL DISSIPATE
RAPIDLY AFTER SUNDOWN. THAT SAID...WILL KEEP RATHER HIGH POP VALUES
AND THE WINTER STORM WARNING GOING...THEN TAPER OFF POP VALUES AFTER
03Z SUNDAY THROUGH 12Z SUNDAY.
THE MAIN CONCERN WILL SHIFT FROM HEAVY MOUNTAINTOP SNOWFALL AND
ELEVATED FLOWS IN NORMALLY DRY WASHES AND STREAMS TO DEVELOPING FOG
LATER TONIGHT AND SUNDAY MORNING. DENSE FOG WAS REPORTED THIS
MORNING IN SPOTS...ESPECIALLY AROUND CASA GRANDE WHERE THE
VISIBILITY DROPPED TO 1/4 OF A MILE AT TIMES. A REPEAT OF THIS FOG
WILL LIKELY BE MORE WIDESPREAD TONIGHT AS SKIES BEGIN TO CLEAR FROM
NORTHWEST TO SOUTHEAST ACROSS THE AREA. NOT SURE HOW DENSE OR WHERE
THE FOG WILL BE AT THIS TIME...SO WILL NOT POST AN ADVISORY ON THE
AFTERNOON FORECAST PACKAGE.
MODELS TRACK THE STORM SYSTEM WELL SOUTH OF THE REGION BY SUNDAY
AFTERNOON WITH A RIDGE OF HIGH PRESSURE BUILDING INTO THE
SOUTHWESTERN UNITED STATES BEHIND IT. THE MEDIUM RANGE MODELS KEEP
THE STORM TRACK NORTH OF THE REGION THIS COMING WEEK. THAT
SAID...THE FORECAST WILL CALL FOR DRY CONDITIONS ALONG WITH A
WARMING TREND. HIGH TEMPERATURES WILL PEAK ABOUT 8 TO 10 DEGREES
ABOVE NORMAL BY THE MIDDLE OF THIS COMING WEEK. FOR TUCSON...THE
NORMAL HIGH THIS TIME OF YEAR IS AROUND 68 DEGREES.
&&
.AVIATION...VALID THRU 02/00Z.
PERIODS OF VALLEY RAIN AND HIGH ELEVATION MOUNTAIN SNOW ABOVE 7K FT
AGL WILL CONTINUE INTO THIS EVENING...BEFORE TAPERING OFF OVERNIGHT
INTO SUNDAY MORNING FROM NORTHWEST TO SOUTHEAST. THERE IS A SLIGHT
CHANCE OF -TSRA ACROSS MUCH OF THE AREA THIS AFTERNOON INTO EARLY
EVENING. CLOUD DECKS OF 2-3K FT AGL ARE LIKELY IN SHOWERS AND
THUNDERSTORMS. OUTSIDE OF PRECIPITATION...EXPECT BKN-OVC CLOUDS AT
3-6K FT AGL. WINDS WILL MAINLY BE LESS THAN 10 KTS. DEPENDING ON
CLOUD COVERAGE LATE TONIGHT...COULD SEE SOME PATCHY FOG BUT
CONFIDENCE TOO LOW TO INCLUDE IN TERMINAL FORECASTS.
OTHERWISE...IMPROVING CONDITIONS SUNDAY WITH DIMINISHING CLOUD
COVERAGE. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...EXPECT PERIODS OF VALLEY RAIN AND MOUNTAIN SNOW INTO
THIS EVENING ALONG WITH WITH A FEW RUMBLES OF THUNDER AS A LOW
PRESSURE SYSTEM MOVES ACROSS THE AREA. A FEW LINGERING SHOWERS WILL
OCCUR MAINLY EAST TO SOUTH OF TUCSON EARLY SUNDAY. DRY CONDITIONS
WILL RETURN SUNDAY AFTERNOON AND LAST THROUGH THE UPCOMING WORK
WEEK. 20-FT WINDS THIS AFTERNOON WILL GENERALLY BE ELY-SLY AT 5-15
MPH. SOME EASTERLY WINDS ARE EXPECTED THURSDAY NIGHT INTO FRIDAY
WITH A FEW HIGHER GUSTS POSSIBLE. OTHERWISE...TYPICAL DIURNAL WIND
TRENDS FOR MUCH OF THE UPCOMING WEEK.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 5 PM MST TODAY FOR AZZ510>512-514.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
213 PM MST SAT JAN 31 2015
.SYNOPSIS...
AN EXITING LOW PRESSURE SYSTEM WILL BRING LINGERING RAIN CHANCES
INTO EARLY TONIGHT TO THE EAST AND SOUTHWEST OF THE PHOENIX AREA.
AREAS OF FOG...POTENTIALLY DENSE ACROSS NORTHERN PINAL
COUNTY...WILL BE POSSIBLE LATE TONIGHT THROUGH SUNDAY MID MORNING
DUE TO ABUNDANT LOW LEVEL MOISTURE AND CLEARING SKIES. HIGH PRESSURE
WILL QUICKLY PUSH IN STARTING SUNDAY BRINGING CLEARING
SKIES...DRYING CONDITIONS...AND WARMER TEMPERATURES. THE DRY
CONDITIONS WILL PERSIST THROUGH THE NEXT WEEK WHILE A SLOW WARMING
TREND ALLOWS FOR HIGHS REACHING NEAR 80 ACROSS THE LOWER DESERTS BY
NEXT FRIDAY.
&&
.DISCUSSION...
THE LATEST SATELLITE AND UPPER HEIGHT ANALYSIS SHOWS THE UPPER
TROUGH STARTING TO PICK UP SOME SPEED MOVING TO THE SOUTHEAST. TWO
DISTINCT CIRCULATION CENTERS CONTINUE TO BE EVIDENT ON WATER VAPOR
IMAGERY...ONE THAT IS QUICKLY WEAKENING AS IT MOVES INTO SOUTHERN
CALIFORNIA AND ANOTHER WELL SOUTH OF THE AREA...CENTERED NEAR
29.7N/114.2W. THE SOUTHERN VORTICITY MAX IS STILL HELPING TO BRING
SCATTERED SHOWERS ACROSS SOUTHEAST AND SOUTH-CENTRAL ARIZONA...WHILE
A FEW MESO-VORTICIES CAN BE SEEN WITHIN RADAR IMAGERY...ONE OVER
SOUTHERN MARICOPA COUNTY AND TWO OTHERS OVER SOUTHERN PINAL COUNTY.
AREAS OF SHOWERS...SOME PRODUCING MODERATE RAIN AT TIMES...ARE
FOCUSED NEAR THESE MESO-VORTICIES...WHILE MORE WIDELY ISOLATED
SHOWERS HAVE BEEN MOVING WESTWARD ACROSS NORTHWEST MARICOPA COUNTY
IN AN AREA OF SLIGHT ENHANCED INSTABILITY FROM SOME PEAKS OF SUN.
THE LATEST HRRR AND WRF4KM HI-RES DATA SHOWS SHOWERS LASTING THROUGH
MID AFTERNOON BEFORE GRADUALLY DIMINISHING BY EARLY EVENING. THIS
SEEMS LIKE A VERY REASONABLE SOLUTION AS THE LARGE SCALE TROUGH
CONTINUES TO DRIFT SOUTHEASTWARD OUT OF THE AREA AND WE SHOULD SEE
ANY OVERLAYING LARGE SCALE ASCENT MOVE OUT OF THE CWA.
ONCE SHOWERS END SOMETIME THIS EVENING...FOCUS THEN TURNS TOWARD THE
POTENTIAL FOR FOG TONIGHT AND SUNDAY MORNING. THE SETUP FOR FOG IS
NOT QUITE IDEAL AS WE SHOULD HAVE SOME LINGERING LOW STRATUS HANGING
AROUND THROUGH FOR THE FIRST OF TONIGHT. HOWEVER...VERY MOIST
SURFACE CONDITIONS WITH SURFACE DEW POINTS IN THE LOW TO MID 50S AND
LIGHT WINDS SHOULD DEFINITELY ALLOW FOR SOME FOG FORMATION ACROSS
THE AREA BY 12Z SUNDAY. MODEL RH FIELDS SHOW DRY AIR WORKING IN
ALOFT FROM THE NORTH AFTER MIDNIGHT...BUT BOUNDARY LAYER CONDITIONS
WILL REMAIN MOIST THROUGH SUNDAY AND POTENTIALLY MONDAY MORNING. THE
POTENTIAL FOR WIDESPREAD FOG AND ANY DENSE FOG WILL MOSTLY RELY ON
HOW MUCH CLEARING HAPPENS TONIGHT. CONFIDENCE IS HIGH THAT WE WILL
SEE FOG IN AT LEAST LOW LYING AND RURAL AREAS ACROSS MARICOPA AND
ESPECIALLY PINAL COUNTY...BUT STILL NOT VERY CONFIDENT ON THE EXTENT
OF ANY FOG IN THE PHOENIX METRO AREA AND FOR ANY DENSE FOG POTENTIAL.
SKIES WILL EVENTUALLY CLEAR OUT BY NOON SUNDAY IF THEY DIDN/T
ALREADY...AND WITH RIDGING AND DRYING ALOFT MOVING IN FROM THE
NORTH...WE WILL BEGIN TO SEE SOME WARMING. WE SHOULD SEE NEAR NORMAL
HIGHS FOR SUNDAY AND THEN A FEW MORE DEGREES FOR MONDAY. THE PACIFIC
RIDGE WILL STAY TO OUR WEST THROUGH THE MIDDLE OF THE WEEK GIVING US
500MB HEIGHTS GENERALLY BETWEEN 574-576DM...BUT MODELS THEN SHIFT
THE RIDGE OVERHEAD BY LATE IN THE WEEK POINTING AT HEIGHTS NEARING
580DM. THIS WILL TRANSLATE INTO A NICE WARM-UP WITH LOWER DESERT
HIGHS APPROACHING 80S DEGREES BY NEXT THURSDAY AND FRIDAY.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA AND KSDL...SCATTERED
SHOWERS CONTINUE TO ROTATE EASTWARD ACROSS THE GREATER PHX AREA AT
THIS HOUR...WITH HAVE RESULTED IN CIGS VARYING BETWEEN 3K FT AND 7
KT FT AT THE TERMINALS THIS AFTERNOON...WITH VISIBILITIES DROPPING
BRIEFLY DOWN TO AS LOW AS 5SM IN THE HEAVIER SHOWERS. THE LATEST
HI-RES MODEL RUNS ARE CONSISTENT WITH EARLIER RUNS...GRADUALLY
DIMINISHING THIS SHOWER ACTIVITY THROUGH THE REMAINDER OF THE
AFTERNOON AND EARLY EVENING AS THE UPPER LOW CONTINUES TO SLIDE TO
THE SOUTH...AND AWAY FROM OUR REGION...WITH SHOWER ACTIVITY PRETTY
MUCH ENDING AROUND/SHORTLY AFTER SUNSET. MID-LEVEL CLOUD LAYERS ARE
THEN EXPECTED TO PERSIST THROUGH MUCH OF TONIGHT. FOG COULD BE A
PROBLEM BY MORNING DUE TO A COMBINATION OF LIGHT WINDS AND AMPLE
LOW-LEVEL MOISTURE. HOWEVER...THE AFOREMENTIONED MID-LEVEL
CLOUDINESS WILL,LIKELY KEEP OVERNIGHT LOW TEMPS UP A BIT...WHICH
SHOULD KEEP ANY FOG THAT ACTUALLY FORMS FROM BECOMING TOO DENSE.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
DRIER AIR MOVING INTO THE REGION FROM THE NORTH IS EXPECTED TO ALLOW
SKIES TO CLEAR AT BOTH TERMINALS THROUGH THE EVENING AND OVERNIGHT
HOURS...WITH MAINLY CLEAR SKIES EXPECTED ON SUNDAY. NORTHERLY TO
NORTHWESTERLY WINDS ARE EXPECTED AT BOTH TERMINALS THROUGH THE TAF
PERIOD...GRADUALLY DIMINISHING AS THE SFC PRESSURE GRADIENT RELAXES.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
DRIER AND SIGNIFICANTLY WARMER WEATHER IS EXPECTED...AS HIGH
PRESSURE BEGINS BUILDING BACK INTO THE REGION. HIGH TEMPERATURES IN
THE LOWER DESERTS WILL START OUT NEAR 70 ON MONDAY AND GRADUALLY
CLIMB TO AROUND 80 BY FRIDAY. LOW LEVEL MOISTURE WILL GRADUALLY
DECREASE THROUGH THE PERIOD...WITH MINIMUM AFTERNOON HUMIDITIES
DECREASING TO AROUND 25 PERCENT BY FRIDAY. WINDS ARE EXPECTED TO BE
LIGHT AND VARIABLE FOR MOST OF THE FORECAST PERIOD.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...KUHLMAN
AVIATION...PERCHA
FIRE WEATHER...MCLANE
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
131 PM PST SAT JAN 31 2015
.SYNOPSIS...
ISOLATED LIGHT SHOWERS FROM A WEAK LOW PRESSURE SYSTEM OVER THE
SOUTHWEST STATES WILL MOSTLY END BY LATE THIS AFTERNOON...WITH
PERHAPS A SHOWER OR TWO OCCURRING THIS EVENING FOR SAN DIEGO COUNTY.
SURFACE HIGH PRESSURE OVER THE GREAT BASIN WILL CONTINUE TO BRING
GUSTY NORTH TO NORTHEAST WINDS NEAR THROUGH AND BELOW THE CAJON PASS
AND INTO THE COASTAL FOOTHILLS THROUGH EARLY SUNDAY MORNING.
CLEARING SKIES AND WARMER WEATHER FOR SUNDAY AS HIGH PRESSURE ALOFT
MOVES IN AND OFFSHORE FLOW WEAKENS. THE MARINE LAYER AND MOSTLY WEAK
ONSHORE OR NEUTRAL FLOW WILL BRING NIGHT AND MORNING LOW CLOUDS AND
PATCHY FOG FOR THE COAST AND PORTIONS OF THE VALLEYS SUNDAY NIGHT
THROUGH THE END OF THE WORK WEEK. HIGH TEMPERATURES WILL BE AROUND
SEASONAL NORMALS NEAR THE COAST TO AROUND 5 TO 10 DEGREES ABOVE
NORMAL FOR INLAND AREAS.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
CURRENT RADAR IMAGERY SHOWS SOME LIGHT RETURNS OVER THE SAN
BERNARDINO COUNTY MOUNTAINS...AND SAN DIEGO COUNTY...WITH SOME
MODERATE SHOWERS OVER THE CENTRAL TO SOUTHERN SAN DIEGO COUNTY
MOUNTAINS. THE 12Z MIRAMAR SOUNDING STILL SHOWED A MOIST ATMOSPHERE
UP THROUGH 300 MB...WITH 0.95 INCHES OF PRECIPITABLE WATER. THIS
MOISTURE...IN ADDITION TO A VORT MAX ASSOCIATED WITH A CLOSED LOW
MOVING THROUGH THE AREA...IS WHAT CONTINUES TO BRING THESE ISOLATED
SHOWERS TO THE REGION. THE LOCAL WRF AND HRRR ACTUALLY SHOW A COUPLE
LIGHT SHOWERS CONTINUING INTO EARLY EVENING FOR CENTRAL AND SOUTHERN
SAN DIEGO COUNTY...SO ADDED A 15 PERCENT CHANCE OF SHOWERS FOR THOSE
AREAS FOR THE EARLY TO MID EVENING HOURS. ANY ADDITIONAL RAINFALL
TODAY SHOULD BE VERY LIGHT...MOSTLY 0.01 OR LESS...WITH LOCAL 0.05
INCH AMOUNTS POSSIBLE. THE SNOW LEVEL WILL CONTINUE AT AROUND 7000
FEET THIS AFTERNOON...WITH ONLY LIGHT SNOWFALL ABOVE THAT ELEVATION
POSSIBLE TODAY INTO THIS EVENING.
SURFACE WIND-FLOW WILL START TO TURN OFFSHORE IN THE NORTH TO
NORTHEAST DIRECTION LATE TODAY...AS SURFACE HIGH PRESSURE BUILDS
OVER THE GREAT BASIN. HOWEVER...THE OFFSHORE WINDS DO NOT LOOK TO BE
VERY STRONG...AS OFFSHORE PRESSURE GRADIENTS FROM SAN DIEGO TO
TONOPAH ONLY INCREASE TO AROUND 6-8 MB...AND ONLY 2-3 MB FROM SAN
DIEGO TO LAS VEGAS. SOME STATIONS ARE ALREADY REPORTING SOME 30-40
MPH GUSTS...BUT SPOTS THAT ARE RECEIVING THE WIND ARE MOSTLY GUSTING
15-25 MPH AT THE MOMENT. SINCE THE OFFSHORE FLOW WILL BE
WEAK...LOCAL WRF INDICATES THAT SOME PATCHY MARINE LAYER STRATUS MAY
DEVELOP IN THE COASTAL AREAS TONIGHT INTO SUNDAY MORNING.
OFFSHORE FLOW WILL WEAKEN ON SUNDAY...AND AN UPPER LEVEL RIDGE WILL
NUDGE INTO THE REGION AS THE TROUGH CONTINUES TO MOVE FAR SOUTH OF
SOUTHERN CALIFORNIA. THIS WILL RESULT IN CLEARING SKIES AND WARMING
WEATHER...WITH DAY-TIME HIGHS RISING SEVERAL DEGREES ABOVE NORMAL.
MOSTLY WEAK ONSHORE TO NEUTRAL FLOW WILL THEN DEVELOP MONDAY THROUGH
FRIDAY...UNDER CONTINUED RIDGING ALOFT...RESULTING IN FAIR WEATHER
WITH BETTER NIGHT AND MORNING STRATUS/FOG COVERAGE FOR THE COAST AND
PORTIONS OF THE VALLEYS. THERE WILL ALSO BE CONTINUED WARMING WITH
DAY-TIME HIGHS RISING TO 5-10 DEGREES ABOVE NORMAL BY TUESDAY.
TEMPERATURES WILL BE NEAR NORMAL AT THE COAST DUE TO THE MARINE
LAYER. OCCASIONAL HIGH CLOUDS PASSING OVER THE AREA WILL MAKE FOR
PARTLY CLOUDY SKIES AT TIMES.
&&
.AVIATION...
312130Z...COAST/VALLEYS...MULTIPLE SCT-BKN CLOUD LAYERS AOA 3500 FT
MSL THROUGH THIS EVENING. PATCHY LOW CLOUDS AND FOG REDEVELOPING
AFTER 01/03Z ALONG THE COAST WITH CIGS 800-1500 FT MSL LIKELY AT
KSAN AND KCRQ...LESS LIKELY AT KSNA. AREAS OF 3-5 SM IN BR POSSIBLE
WITHIN 10 SM OF THE COAST. FORECAST CONFIDENCE IN COVERAGE AND CIG
HEIGHTS IS MODERATE. CIGS AND VIS EXPECTED TO CLEAR BY MID-MORNING
SUNDAY.
MTS/DESERTS...NORTHERLY WINDS 15-20 KT WITH SFC GUSTS UP TO 40 KT
WILL OCCUR ALONG THE RIDGES OF THE SAN BERNARDINO MTNS...BELOW THE
CAJON PASS...NORTHERN COACHELLA VALLEY...AND THROUGH THE CANYONS OF
THE SANTA ANA MTNS. WINDS GRADUALLY DECREASING THROUGH EARLY SUNDAY
MORNING...THOUGH REMAINING WEAKLY OFFSHORE TO THE NORTH.
OTHERWISE...SCT CLOUDS AOA 10000 FT MSL THROUGH SUNDAY MORNING.
&&
.MARINE...
130 PM....SLIGHT CHANCE OF MAINLY LIGHT SHOWERS OVER THE INNER
COASTAL WATERS THROUGH THIS EVENING. OTHERWISE...NO HAZARDOUS
MARINE WEATHER IS EXPECTED THROUGH WEDNESDAY.
&&
.SKYWARN...
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.
&&
$$
PUBLIC...HARRISON
AVIATION/MARINE...23
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
334 PM CST SAT JAN 31 2015
...UPDATED FOR LONG TERM DISCUSSION...
.SHORT TERM...(TONIGHT AND SUNDAY)
ISSUED AT 232 PM CST SAT JAN 31 2015
AN UPPER LEVEL TROUGH, LOCATED OVER WESTERN MONTANA EARLIER THIS
MORNING, WILL MOVE ACROSS WESTERN KANSAS DURING THE OVERNIGHT
HOURS. AS THIS SYSTEM APPROACHES FROM THE NORTHWEST THIS
EVENING...850MB TO 700MB FRONTOGENESIS WILL DEVELOP ACROSS
SOUTHWEST KANSAS. THIS AREA OF FRONTOGENISIS WILL MOVE VERY LITTLE
BETWEEN 03Z AND 06Z SUNDAY BASED ON THE 12Z NAM AND THIS AREA OF
ENHANCED FORCING WILL BRING WIDESPREAD PRECIPITATION BACK TO
SOUTHWEST KANSAS EARLY TONIGHT. AT THIS TIME BASED ON THE TOP DOWN
APPROACH THE PRECIPITATION THIS EVENING WILL BE MAINLY LIQUID,
HOWEVER AS COLDER AIR BEGINS TO MOVE INTO SOUTHWEST TOWARDS
MIDNIGHT THIS WIDESPREAD LIGHT RAIN WILL BEGIN TO MIX WITH SNOW
AFTER 03Z. AREA MORE FAVORABLE FOR THE RAIN TO SNOW CHANGE OVER
BEFORE MIDNIGHT WILL BE MAINLY ACROSS NORTH CENTRAL AND WEST
CENTRAL KANSAS. AFTER MIDNIGHT THE AREA OF 850MB TO 700MB
FRONTOGENESIS WILL MOVE QUICKLY MOVE SOUTHEAST AS THE UPPER LEVEL
THE UPPER LEVEL TROUGH CROSSES WESTERN KANSAS BETWEEN 06Z AND 12Z
SUNDAY. AS THIS UPPER LEVEL TROUGH PASSES THE PRECIPITATION WILL
BEGIN TAPER OFF FROM NORTHWEST TO SOUTHEAST. AS COLD AIR SPREADS
ACROSS WESTERN KANSAS LATE TONIGHT THE RAIN IS EXPECTED TO MIX
WITH OR BRIEFLY CHANGE TO SNOW BEFORE ENDING ACROSS SOUTHWEST AND
SOUTH CENTRAL KANSAS. GIVEN A QUICKER RAIN TO SNOW CHANGE OVER
ACROSS NORTH CENTRAL AND PORTIONS OF WEST CENTRAL KANSAS THERE
WILL BE A CHANCE FOR UP TO ONE INCH OF SNOW OVERNIGHT NORTH OF
HIGHWAY 50. FURTHER SOUTH ANY ACCUMULATION IS EXPECTED TO BE LIGHT
AND MAINLY ON GRASSY AND ELEVATED SURFACES.
STRONG NORTH WINDS WILL DEVELOP LATE TONIGHT BEHIND A COLD FRONT
THAT WILL BE CROSSING WESTERN KANSAS BETWEEN 06Z AND 12Z SUNDAY.
TIMING OF THIS COLD FRONT IS STILL UNCLEAR, HOWEVER ALL MODELS DO
AGREE THAT STRONG WINDS WILL DEVELOP BEHIND THIS COLD FRONT LATE
TONIGHT AND EARLY SUNDAY. GUSTY NORTH WINDS OF 25 TO 35 MPH WILL
BE LIKELY EARLY SUNDAY BASED ON THE TIGHT SURFACE PRESSURE
GRADIENT AND THE FORECAST MEAN MIXED LAYER WINDS BEHIND THIS
FRONT.
TEMPERATURES OVERNIGHT WILL NOT FALL VERY QUICKLY UNTIL THE
FRONTAL PASSAGE AFTER MIDNIGHT. TEMPERATURE WILL THEN DROP BASED
MAGNITUDE OF THE COLD AIR ADVECTION FORECAST TOWARDS 12Z SUNDAY.
AT THIS TIME WILL STAY CLOSE TO THE LATEST GUIDANCE GIVEN THE
UNCERTAINTY OF THE FRONTAL PASSAGE LATER TONIGHT. ON SUNDAY SKIES
WILL CLEAR BUT BASED ON THE 900MB TO 850MB TEMPERATURE TRENDS THE
HIGHS ON SUNDAY WILL STRUGGLE TO CLIMB INTO THE MID 20S IN NORTH
CENTRAL KANSAS AND NEAR THE OKLAHOMA BORDER THE HIGHS WILL BE
MAINLY IN THE LOW TO MID 30S.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 231 PM CST SAT JAN 31 2015
THE MID TO UPPER LEVEL FLOW WILL BE NORTHWESTERLY THROUGH THE
WEEK, WITH UPPER LEVEL RIDGING NEAR THE WEST COAST AND TROUGHING
OVER THE EASTERN UNITED STATES. HOWEVER, ONE PARTICULAR UPPER
LEVEL FEATURE THAT WILL PLAY A LARGE ROLE IN DAY TO DAY WEATHER IS
A STRONG SHORTWAVE TROUGH ENTERING THE NORTHERN PLAINS ON TUESDAY
AND THEN PROGRESSING INTO THE NORTHEAST BY THURSDAY. AHEAD OF
THIS FEATURE, LEE TROUGHING WILL RESULT IN MILDER TEMPERATURES
MONDAY AND TUESDAY WITH HIGHS WARMING INTO THE 60S BY TUESDAY.
MUCH COLDER AIR IS EXPECTED BY WEDNESDAY INTO EARLY THURSDAY IN
THE WAKE OF THIS FEATURE AS A SMALL AREA OF ARCTIC HIGH PRESSURE
PUSHES SOUTHWARD INTO KANSAS. HIGHS MAY NOT MAKE IT OUT OF THE
20S ACROSS MUCH OF SOUTHWEST KANSAS WEDNESDAY. THE ONLY CHANCE OF
PRECIPITATION IN THE FORM OF SNOW, ALBEIT SLIGHT, WILL BE
WEDNESDAY AND WEDNESDAY NIGHT AS MID LEVEL FRONTOGENESIS DEVELOPS
ACROSS WESTERN KANSAS. ANOTHER WARM UP CAN BE EXPECTED THURSDAY
AND FRIDAY AS THE MID LEVEL FLOW BECOMES MORE ZONAL, WITH WEAK
RIDGING OVER THE ROCKIES AND SURFACE TROUGHING IN THE LEE OF THE
ROCKIES. HIGH TEMPERATURES OUGHT TO RISE INTO THE 40S TO LOWER 50S
BY THURSDAY, WITH 60S AND POSSIBLY EVEN LOWER 70S FRIDAY. AFTER
FRIDAY, A SHORTWAVE TROUGH OVER THE ROCKIES IS EXPECTED TO
PROGRESS EASTWARD AND AMPLIFY INTO A LARGE UPPER LEVEL STORM
SYSTEM OVER THE SOUTHEASTERN UNITED STATES BY SUNDAY AND MONDAY
(FEB 8TH-9TH). ANY PRECIPITATION WITH THIS FEATURE SHOULD BE WELL
OFF TO THE EAST, WITH TEMPERATURES NEAR TO ABOVE SEASONAL AVERAGES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1105 AM CST SAT JAN 31 2015
LIGHT RAIN WILL CONTINUE TO TAPER OFF FROM SOUTHWEST TO NORTHEAST
EARLY THIS AFTERNOON AS GUSTY SOUTH WINDS DECREASE INTO THE 10 TO
15 KNOT RANGE BY LATE DAY. THE CEILINGS WILL IMPROVE SOME, HOWEVER
BASED ON THE 12Z BUFR SOUNDINGS AND THE LATEST HRRR CEILINGS ARE
ONLY EXPECTED TO INCREASE INTO THE 1500FT TO 2000FT AGL LEVEL BY
LATE DAY. A COLD FRONT WILL CROSS SOUTHWEST KANSAS EARLY TONIGHT.
HRRR HAS THE FRONT PASSING HYS AND GCK BETWEEN 02Z AND 05Z AND DDC
NEAR OR SHORTLY AFTER 06Z. AS THIS FRONT PASSES THE WINDS WILL
SHIFT TO THE NORTHWEST AND THEN INCREASE TO NEAR 20 KNOTS. THERE
WILL ALSO BE A CHANCE FOR A BRIEF PERIOD OF RAIN OR SNOW BEHIND
THIS COLD FRONT AS AN UPPER LEVEL TROUGH CROSSES THE CENTRAL HIGH
PLAINS. AFTER 12Z SUNDAY WIND SPEEDS WILL INCREASE TO AROUND 25
KNOTS AS LOW CLOUDS GIVE WAY TO CLEARING SKIES.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 27 30 14 44 / 70 10 0 0
GCK 27 31 14 49 / 70 0 0 0
EHA 30 36 19 56 / 60 0 0 0
LBL 31 36 18 50 / 60 10 0 0
HYS 23 26 11 44 / 80 10 0 0
P28 30 33 14 39 / 70 20 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BURGERT
LONG TERM...FINCH
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
235 PM CST SAT JAN 31 2015
...UPDATED SHORT TERM DISCUSSION...
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 232 PM CST SAT JAN 31 2015
AN UPPER LEVEL TROUGH, LOCATED OVER WESTERN MONTANA EARLIER THIS
MORNING, WILL MOVE ACROSS WESTERN KANSAS DURING THE OVERNIGHT
HOURS. AS THIS SYSTEM APPROACHES FROM THE NORTHWEST THIS
EVENING...850MB TO 700MB FRONTOGENESIS WILL DEVELOP ACROSS
SOUTHWEST KANSAS. THIS AREA OF FRONTOGENISIS WILL MOVE VERY LITTLE
BETWEEN 03Z AND 06Z SUNDAY BASED ON THE 12Z NAM AND THIS AREA OF
ENHANCED FORCING WILL BRING WIDESPREAD PRECIPITATION BACK TO
SOUTHWEST KANSAS EARLY TONIGHT. AT THIS TIME BASED ON THE TOP DOWN
APPROACH THE PRECIPITATION THIS EVENING WILL BE MAINLY LIQUID,
HOWEVER AS COLDER AIR BEGINS TO MOVE INTO SOUTHWEST TOWARDS
MIDNIGHT THIS WIDESPREAD LIGHT RAIN WILL BEGIN TO MIX WITH SNOW
AFTER 03Z. AREA MORE FAVORABLE FOR THE RAIN TO SNOW CHANGE OVER
BEFORE MIDNIGHT WILL BE MAINLY ACROSS NORTH CENTRAL AND WEST
CENTRAL KANSAS. AFTER MIDNIGHT THE AREA OF 850MB TO 700MB
FRONTOGENESIS WILL MOVE QUICKLY MOVE SOUTHEAST AS THE UPPER LEVEL
THE UPPER LEVEL TROUGH CROSSES WESTERN KANSAS BETWEEN 06Z AND 12Z
SUNDAY. AS THIS UPPER LEVEL TROUGH PASSES THE PRECIPITATION WILL
BEGIN TAPER OFF FROM NORTHWEST TO SOUTHEAST. AS COLD AIR SPREADS
ACROSS WESTERN KANSAS LATE TONIGHT THE RAIN IS EXPECTED TO MIX
WITH OR BRIEFLY CHANGE TO SNOW BEFORE ENDING ACROSS SOUTHWEST AND
SOUTH CENTRAL KANSAS. GIVEN A QUICKER RAIN TO SNOW CHANGE OVER
ACROSS NORTH CENTRAL AND PORTIONS OF WEST CENTRAL KANSAS THERE
WILL BE A CHANCE FOR UP TO ONE INCH OF SNOW OVERNIGHT NORTH OF
HIGHWAY 50. FURTHER SOUTH ANY ACCUMULATION IS EXPECTED TO BE LIGHT
AND MAINLY ON GRASSY AND ELEVATED SURFACES.
STRONG NORTH WINDS WILL DEVELOP LATE TONIGHT BEHIND A COLD FRONT
THAT WILL BE CROSSING WESTERN KANSAS BETWEEN 06Z AND 12Z SUNDAY.
TIMING OF THIS COLD FRONT IS STILL UNCLEAR, HOWEVER ALL MODELS DO
AGREE THAT STRONG WINDS WILL DEVELOP BEHIND THIS COLD FRONT LATE
TONIGHT AND EARLY SUNDAY. GUSTY NORTH WINDS OF 25 TO 35 MPH WILL
BE LIKELY EARLY SUNDAY BASED ON THE TIGHT SURFACE PRESSURE
GRADIENT AND THE FORECAST MEAN MIXED LAYER WINDS BEHIND THIS
FRONT.
TEMPERATURES OVERNIGHT WILL NOT FALL VERY QUICKLY UNTIL THE
FRONTAL PASSAGE AFTER MIDNIGHT. TEMPERATURE WILL THEN DROP BASED
MAGNITUDE OF THE COLD AIR ADVECTION FORECAST TOWARDS 12Z SUNDAY.
AT THIS TIME WILL STAY CLOSE TO THE LATEST GUIDANCE GIVEN THE
UNCERTAINTY OF THE FRONTAL PASSAGE LATER TONIGHT. ON SUNDAY SKIES
WILL CLEAR BUT BASED ON THE 900MB TO 850MB TEMPERATURE TRENDS THE
HIGHS ON SUNDAY WILL STRUGGLE TO CLIMB INTO THE MID 20S IN NORTH
CENTRAL KANSAS AND NEAR THE OKLAHOMA BORDER THE HIGHS WILL BE
MAINLY IN THE LOW TO MID 30S.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 324 AM CST SAT JAN 31 2015
IN THE LONGER TERM THE GREATEST CHALLENGE WILL BE TEMPERATURES,
BOTH SPATIALLY AND THE MAGNITUDE. EARLY SUNDAY THE MOST LIKELY
TIMING OF THE NORTHERN BRANCH OF THE WESTERLIES SHORT WAVE TROUGH
WILL BE EXITING MY SOUTHEAST COUNTIES. THERE COULD BE LINGERING
LIGHT PRECIPITATION (MOST LIKELY LIGHT SNOW) AROUND BARBER COUNTY
EARLY SUNDAY MORNING. ELSEWHERE, SKIES SHOULD BE GRADUALLY
CLEARING IN PRESENCE OF STRONG COLD AIR ADVECTION. THE AIR BEHIND
THE FRONT THAT MOVES THROUGH EARLIER WILL BE ARCTIC IN NATURE.
HOWEVER, MY AREA WILL BE ON THE FRINGE OF THE AIRMASS. STILL,
TEMPERATURES DURING THE DAY SUNDAY WILL NOT GET ABOVE FREEZING
ALONG THE I-70 CORRIDOR BUT MAY STILL WARM A LITTLE AROUND
ELKHART.
BY MONDAY ANOTHER FAST MOVING S/WV TROUGH IN THE NORTHERN BRANCH
OF THE WESTERLIES WILL HELP LOWER PRESSURES ALONG THE LEE OF THE
ROCKIES AND SUBSEQUENTLY PRODUCE A SOUTHERLY FLOW NEAR THE
SURFACE. WARMING WILL BE MOST PREVALENT NEAR THE COLORADO BORDER.
BUT, HOW FAR EAST THE MIXING OCCURS AND RESULTANT WARMING IS IN
QUESTION. MY EASTERN COUNTIES COULD VERY WELL STAY ENTRENCHED IN
THE RETREATING ARCTIC AIR UNTIL LATE AFTERNOON. TEMPERATURES ON
MONDAY HAVE SOME BUST POTENTIAL.
YET ANOTHER FAST MOVING S/WV TROUGH IN THE NORTHERN BRANCH
WESTERLIES WILL HAVE A SURFACE RESPONSE IN THE FORM OF ANOTHER
ARCTIC AIRMASS FRONT THAT SHOULD ARRIVE LATE TUESDAY OR
WEDNESDAY. TIMING IS UNCERTAIN BUT MID-WEEK LOOKS MOST LIKELY. IN
ADDITION, THERE SHOULD BE ENOUGH DYNAMICS AND BAROCLINICITY TO
PROMOTE SOME PRECIPITATION, ALTHOUGH MOST LIKELY LIGHT (AND IN THE
FORM OF FROZEN).
ANOTHER WARM-UP IS EXPECTED LATER IN THE WEEK AS UPPER HEIGHTS
BUILD A LITTLE AND THE WESTERLIES RETREAT A BIT NORTH.&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1105 AM CST SAT JAN 31 2015
LIGHT RAIN WILL CONTINUE TO TAPER OFF FROM SOUTHWEST TO NORTHEAST
EARLY THIS AFTERNOON AS GUSTY SOUTH WINDS DECREASE INTO THE 10 TO
15 KNOT RANGE BY LATE DAY. THE CEILINGS WILL IMPROVE SOME, HOWEVER
BASED ON THE 12Z BUFR SOUNDINGS AND THE LATEST HRRR CEILINGS ARE
ONLY EXPECTED TO INCREASE INTO THE 1500FT TO 2000FT AGL LEVEL BY
LATE DAY. A COLD FRONT WILL CROSS SOUTHWEST KANSAS EARLY TONIGHT.
HRRR HAS THE FRONT PASSING HYS AND GCK BETWEEN 02Z AND 05Z AND DDC
NEAR OR SHORTLY AFTER 06Z. AS THIS FRONT PASSES THE WINDS WILL
SHIFT TO THE NORTHWEST AND THEN INCREASE TO NEAR 20 KNOTS. THERE
WILL ALSO BE A CHANCE FOR A BRIEF PERIOD OF RAIN OR SNOW BEHIND
THIS COLD FRONT AS AN UPPER LEVEL TROUGH CROSSES THE CENTRAL HIGH
PLAINS. AFTER 12Z SUNDAY WIND SPEEDS WILL INCREASE TO AROUND 25
KNOTS AS LOW CLOUDS GIVE WAY TO CLEARING SKIES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1105 AM CST SAT JAN 31 2015
LIGHT RAIN WILL CONTINUE TO TAPER OFF FROM SOUTHWEST TO NORTHEAST
EARLY THIS AFTERNOON AS GUSTY SOUTH WINDS DECREASE INTO THE 10 TO
15 KNOT RANGE BY LATE DAY. THE CEILINGS WILL IMPROVE SOME, HOWEVER
BASED ON THE 12Z BUFR SOUNDINGS AND THE LATEST HRRR CEILINGS ARE
ONLY EXPECTED TO INCREASE INTO THE 1500FT TO 2000FT AGL LEVEL BY
LATE DAY. A COLD FRONT WILL CROSS SOUTHWEST KANSAS EARLY TONIGHT.
HRRR HAS THE FRONT PASSING HYS AND GCK BETWEEN 02Z AND 05Z AND DDC
NEAR OR SHORTLY AFTER 06Z. AS THIS FRONT PASSES THE WINDS WILL
SHIFT TO THE NORTHWEST AND THEN INCREASE TO NEAR 20 KNOTS. THERE
WILL ALSO BE A CHANCE FOR A BRIEF PERIOD OF RAIN OR SNOW BEHIND
THIS COLD FRONT AS AN UPPER LEVEL TROUGH CROSSES THE CENTRAL HIGH
PLAINS. AFTER 12Z SUNDAY WIND SPEEDS WILL INCREASE TO AROUND 25
KNOTS AS LOW CLOUDS GIVE WAY TO CLEARING SKIES.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 27 30 14 44 / 70 10 0 0
GCK 27 31 14 49 / 70 0 0 0
EHA 30 36 19 56 / 60 0 0 0
LBL 31 36 18 50 / 60 10 0 0
HYS 23 26 11 44 / 80 10 0 0
P28 30 33 14 39 / 70 20 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BURGERT
LONG TERM...HUTTON
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1109 AM CST SAT JAN 31 2015
...UPDATED SYNOPSIS AND AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 1105 AM CST SAT JAN 31 2015
AT 12Z SATURDAY A 500MB RIDGE AXIS EXTENDED FROM EASTERN TEXAS
INTO KANSAS. A 500MB LOW LOCATED OVER WESTERN ARIZONA. FURTHER
NORTH A 500MB TROUGH WAS LOCATED OVER WESTERN MONTANA WITH A
500MB BAROCLINIC ZONE EXTENDING FROM NORTHERN IDAHO TO NORTHWEST
MISSOURI. AT THE 700MB AND 850MB LEVEL A SOUTH/SOUTHWEST FLOW WAS
CONTINUING TO DRAW MOISTURE NORTHWARD ACROSS SOUTHWEST AND CENTRAL
KANSAS INTO NORTHEASTERN NEBRASKA. 850MB TEMPERATURES THIS
MORNING AT 12Z WERE -1C AT AMARILLO AND DODGE CITY AND -2C AT
NORTH PLATTE AND TOPEKA. AN 850MB FRONT EXTENDED FROM EASTERN
MONTANA TO WISCONSIN. THE SURFACE COLD FRONT THIS MORNING AT 12Z
SATURDAY EXTENDED FROM NORTHERN IOWA, ACROSS NORTHERN NEBRASKA,
INTO NORTHEAST WYOMING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 210 AM CST SAT JAN 31 2015
MOSTLY CLOUDY SKIES WILL CONTINUE TODAY AS MOISTURE AND LIFT
INCREASES ABOVE WESTERN KANSAS. THIS IS AS AN UPPER LEVEL LOW
SPINS ABOVE THE BAJA REGION AND AN UPPER LEVEL SHORTWAVE MOVES
SOUTH ACROSS THE NORTHERN ROCKIES AND NORTHERN PLAINS.
PRECIPITATION CHANCES WILL CONTINUE THROUGHOUT THE DAY WITH THE
BEST CHANCE OF MEASURABLE PRECIPITATION ALONG THE KS/OK BORDER AS
WELL AS SOUTH CENTRAL KANSAS AND CENTRAL KANSAS. ANY PRECIPITATION
THAT FALLS TODAY SHOULD REMAIN AS RAIN WITH THE EXCEPTION OF THE
I-70 CORRIDOR THIS MORNING WHERE SNOW WILL BE POSSIBLE. WINDS WILL
GENERALLY BE FROM THE SOUTH TODAY BECOMING BREEZY IN THE
AFTERNOON. PRECIPITATION CHANCES END FROM NORTHWEST TO SOUTHEAST
TONIGHT WITH CONTINUED MOSTLY CLOUDY SKIES. PRECIPITATION MAY MIX
WITH OR CHANGE ALL OVER TO SNOW AS WE APPROACH SUNRISE. A COLD
FRONT WILL MOVE THROUGH THE AREA OVERNIGHT SHIFTING WINDS TO MORE
OF A NORTHERLY DIRECTION. HIGHS TODAY ARE EXPECTED TO ONLY REACH
INTO THE LOW TO MID 40S WITH LOWS TONIGHT RANGING FROM THE MID 20S
ACROSS THE I-70 CORRIDOR TO LOWER 30S ACROSS THE KS/OK BORDER.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 324 AM CST SAT JAN 31 2015
IN THE LONGER TERM THE GREATEST CHALLENGE WILL BE TEMPERATURES,
BOTH SPATIALLY AND THE MAGNITUDE. EARLY SUNDAY THE MOST LIKELY
TIMING OF THE NORTHERN BRANCH OF THE WESTERLIES SHORT WAVE TROUGH
WILL BE EXITING MY SOUTHEAST COUNTIES. THERE COULD BE LINGERING
LIGHT PRECIPITATION (MOST LIKELY LIGHT SNOW) AROUND BARBER COUNTY
EARLY SUNDAY MORNING. ELSEWHERE, SKIES SHOULD BE GRADUALLY
CLEARING IN PRESENCE OF STRONG COLD AIR ADVECTION. THE AIR BEHIND
THE FRONT THAT MOVES THROUGH EARLIER WILL BE ARCTIC IN NATURE.
HOWEVER, MY AREA WILL BE ON THE FRINGE OF THE AIRMASS. STILL,
TEMPERATURES DURING THE DAY SUNDAY WILL NOT GET ABOVE FREEZING
ALONG THE I-70 CORRIDOR BUT MAY STILL WARM A LITTLE AROUND
ELKHART.
BY MONDAY ANOTHER FAST MOVING S/WV TROUGH IN THE NORTHERN BRANCH
OF THE WESTERLIES WILL HELP LOWER PRESSURES ALONG THE LEE OF THE
ROCKIES AND SUBSEQUENTLY PRODUCE A SOUTHERLY FLOW NEAR THE
SURFACE. WARMING WILL BE MOST PREVALENT NEAR THE COLORADO BORDER.
BUT, HOW FAR EAST THE MIXING OCCURS AND RESULTANT WARMING IS IN
QUESTION. MY EASTERN COUNTIES COULD VERY WELL STAY ENTRENCHED IN
THE RETREATING ARCTIC AIR UNTIL LATE AFTERNOON. TEMPERATURES ON
MONDAY HAVE SOME BUST POTENTIAL.
YET ANOTHER FAST MOVING S/WV TROUGH IN THE NORTHERN BRANCH
WESTERLIES WILL HAVE A SURFACE RESPONSE IN THE FORM OF ANOTHER
ARCTIC AIRMASS FRONT THAT SHOULD ARRIVE LATE TUESDAY OR
WEDNESDAY. TIMING IS UNCERTAIN BUT MID-WEEK LOOKS MOST LIKELY. IN
ADDITION, THERE SHOULD BE ENOUGH DYNAMICS AND BAROCLINICITY TO
PROMOTE SOME PRECIPITATION, ALTHOUGH MOST LIKELY LIGHT (AND IN THE
FORM OF FROZEN).
ANOTHER WARM-UP IS EXPECTED LATER IN THE WEEK AS UPPER HEIGHTS
BUILD A LITTLE AND THE WESTERLIES RETREAT A BIT NORTH.&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1105 AM CST SAT JAN 31 2015
LIGHT RAIN WILL CONTINUE TO TAPER OFF FROM SOUTHWEST TO NORTHEAST
EARLY THIS AFTERNOON AS GUSTY SOUTH WINDS DECREASE INTO THE 10 TO
15 KNOT RANGE BY LATE DAY. THE CEILINGS WILL IMPROVE SOME, HOWEVER
BASED ON THE 12Z BUFR SOUNDINGS AND THE LATEST HRRR CEILINGS ARE
ONLY EXPECTED TO INCREASE INTO THE 1500FT TO 2000FT AGL LEVEL BY
LATE DAY. A COLD FRONT WILL CROSS SOUTHWEST KANSAS EARLY TONIGHT.
HRRR HAS THE FRONT PASSING HYS AND GCK BETWEEN 02Z AND 05Z AND DDC
NEAR OR SHORTLY AFTER 06Z. AS THIS FRONT PASSES THE WINDS WILL
SHIFT TO THE NORTHWEST AND THEN INCREASE TO NEAR 20 KNOTS. THERE
WILL ALSO BE A CHANCE FOR A BRIEF PERIOD OF RAIN OR SNOW BEHIND
THIS COLD FRONT AS AN UPPER LEVEL TROUGH CROSSES THE CENTRAL HIGH
PLAINS. AFTER 12Z SUNDAY WIND SPEEDS WILL INCREASE TO AROUND 25
KNOTS AS LOW CLOUDS GIVE WAY TO CLEARING SKIES.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 41 26 33 14 / 90 60 10 0
GCK 43 25 35 14 / 30 50 0 0
EHA 44 28 40 19 / 30 40 0 0
LBL 42 29 38 18 / 90 50 10 0
HYS 39 24 27 11 / 90 70 10 0
P28 41 30 35 14 / 100 70 20 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...HOVORKA_42
LONG TERM...HUTTON
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
344 PM EST SAT JAN 31 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 340 PM EST SAT JAN 31 2015
THIS AFTERNOON THROUGH SUNDAY...HIGH PRESSURE SLIDING ACROSS CENTRAL
CANADA THIS AFTERNOON HAS ALLOW NORTHERLY FLOW TO INCREASE ACROSS
MUCH OF THE UPPER GREAT LAKES REGION. THIS NORTHERLY FLOW COUPLED
WITH 850MB TEMPERATURES COOLING TO AROUND -18C TO -20C HAS ALLOWED
LAKE EFFECT SNOW TO DEVELOP AHEAD OF THE SURFACE HIGH PRESSURE
SYSTEM. INITIALLY...DEEPER MOISTURE WILL LINGER INTO THE EARLY
EVENING HOURS ALLOWING BETTER SNOW GROWTH WITH A THICKER SNOW GROTH
AREA WITHIN THE DGZ. RUC SOUNDINGS SHOW INVERSION HEIGHTS BETWEEN
4KFT AND 5KFT THIS AFETERNOON WHICH IS ALSO VERIFIED BY THE MQT VAD
WIND PROFILE THIS AFETERNOON. THIS HAS ALLOWED GOOD SNOWFLAKE SIZE
THIS AFTERNOON RESULTING IN A QUICK INCH OR TWO OF FLUFFY SNOW ON A
NORTH TO NORTHWESTERLY WIND. DRY AIR REMAINS JUST TO THE NORTH OF
THE AREA THIS AFTERNOON...HOWEVER...THIS IS EXPECTED TO SHIFT
FARTHER SOUTH AROUND 00Z/01 AS INVERSION HEIGHTS BEGIN TO FALL TO
AROUND 3KFT. THIS SHOULD HELP TO REDUCE SNOWFALL RATES THIS EVENING
INTO THE OVERNIGHT HOURS.
AS THE SURFACE RIDGE EXPANDS TO THE NORTH OF LAKE SUPERIOR EXPECT
WINDS TO SHIFT TO THE NORTH AND NORTHEAST SHIFTING THE SNOWBANDS TO
THE NORTH TO NORTHEAST WIND FAVORED SNOW BELTS. AGAIN...REDUCED
MOISTURE...LOWERED INVERSION HEIGHTS ALONG WITH ANTICYCLONIC FLOW
WILL HELP TO KEEP SNOWFALL TOTALS IN CHECK ACROSS THE U.P. WITH UP
TO 2 INCHES EXPECTED ALONG THE NORTH TO NORTHEAST WIND FAVORED SNOW
BELTS. AS THE SURFACE RIDGE CENTER SHIFTS INTO THE NORTHERN PLAINS
ON SUNDAY EXPECT WINDS TO SHIFT TO A MORE NORTHERLY DIRECTION.
TEMPERATURES ALOFT WILL REMAIN COLD ENOUGH AND LOW LEVEL MOISTURE
OFF LAKE SUPERIOR WILL KEEP LAKE EFFECT SNOW IN NORTHERLY WIND
FAVORED LOCATIONS...WITH AROUND AN INCH ACCUMULATION EXPECTED IN
THESE AREAS.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 340 PM EST SAT JAN 31 2015
...NW FLOW LES AND POOR VSBY DUE TO BLSN/DRSN MAY LEAD TO HEADLINES
WEDNESDAY INTO THURSDAY...
COLD WEEK IN STORE AS A BUILDING RIDGE ALOFT OVER WESTERN NORTH
AMERICA RESULTS IN MEAN TROUGHING CENTERED OVER HUDSON BAY EXTENDING
OVER GREAT LAKES AND NORTHEAST CONUS. PATTERN DOES NOT HOLD MUCH
OPPORTUNITY FOR WIDESPREAD SNOW. BEST CHANCE OF THAT MAY ACTUALLY
COME FRIDAY. OTHERWISE...LAKE EFFECT SNOW AND BLOWING/DRIFTING SNOW
WITH POOR VISIBILITY WILL BE MAIN ISSUE. APPEARED THAT MODERATION IN
THE CHILL WOULD START TO DEVELOP BY NEXT WEEKEND...BUT RECENT RUNS OF
THE ECMWF/GFS HAVE TRENDED TOWARD MORE TROUGHING AND COLDER
TEMPERATURES. WILL HAVE TO WAIT AND SEE IF THIS IS A LASTING TREND.
HIGH IMPACT WEATHER THAT JUSTIFIES ANY TYPE OF HEADLINES THROUGH THE
EXTENDED LIKELY WILL BE TIED TO THE LAKE EFFECT SNOW AND POOR VSBY.
BEST CHANCE OF SEEING HEADLINES WILL BE WEDNESDAY INTO THURSDAY FOR
NW FLOW AREAS NEAR LK SUPERIOR. WILL ALSO GIVE AN HONORABLE MENTION
FOR WSW FLOW ON TIP OF KEWEENAW PENINSULA LATE MONDAY INTO MONDAY
NIGHT...AS THOUGH THIS IS A VERY LOW PROBABILITY EVENT IT COULD NEED
A HEADLINE IF IT OCCURS. SUPPOSE THERE ALSO COULD BE NEED FOR WIND
CHILL ADVYS MONDAY MORNING AND AGAIN THURSDAY MORNING...BUT ATTM IT
DOES NOT LOOK LIKE A SURE THING THANKS TO LIGHT WINDS AND/OR MORE IN
TERMS OF LAKE MODERATION ON TEMPS.
NO REAL HAZARDOUS WEATHER EXPECTED SUNDAY NIGHT INTO MONDAY MORNING
WITH DIMINISHING WINDS AND WEAK LES AS INVERSIONS ARE WELL BLO 5KFT.
PLENTY COLD WITH TEMPS AT INVERION TOP BLO -20C. SLR/S ON THE
HIGHER/FLUFFY SIDE SO A COUPLE OF INCHES OF SNOW IS POSSIBLE FOR
MAINLY NCNTRL UPR MICHIGAN. GIVEN THE WEAKENING WINDS...MESOLOW
FORMATION REMAINS POSSIBLE WHICH WOULD ENHANCE CONVERGENCE AND ADD
TO THE SNOW AMOUNTS. HIGHEST PROBABILITY OF THIS OCCURRING WOULD BE
BTWN MARQUETTE AND PICTURED ROCKS LAKESHORE...SO LOOKING AT AU TRAIN
AND MUNISING AREAS. AWAY FM THE LES...TEMPS FALL WELL BLO ZERO LATE
SUNDAY NIGHT INTO MONDAY MORNING...BUT WITH LIGHT WINDS AND SOME
LAKE MODERATION/LAKE EFFECT CLOUDS...WIND CHILLS WILL MAINLY STAY
HIGHER THAN 20 BLO. SFC TROUGH CROSSING THE AREA MONDAY MORNING
SHOULD RESULT IN WINDS BECOMING MORE WESTERLY WHICH WILL DISRUPT THE
LES OVER ALGER COUNTY BUT WILL INCREASE IT ON THE KEWEENAW PENINSULA.
WESTERLY CONVERGENT FLOW LES HAS POTENTIAL TO DROP SEVERAL INCHES OF
SNOW LATE MONDAY AFTN INTO MONDAY NIGHT OVER NORTHERN SECTIONS OF
THE KEWEENAW. SOUNDINGS SHOW INVERSION AT LEAST TO 5KFT AND
DISTURBANCE ROTATING THROUGH AHEAD OF ANOTHER TROUGH MOVING OVER
UPPER GREAT LAKES ON TUESDAY MORNING. NAM SHARPER WITH TROUGH AND
BACKS WINDS ENOUGH TO KEEP HEAVIER LES OFFSHORE OF KEWEENAW. GFS AND
ECMWF NOT AS BACKED WITH WINDS. WILL CONTINUE TO SHOW HIGHEST POPS
ON THE KEWEENAW AND MENTION IN HAZARDOUS WEATHER OUTLOOK.
TROUGH SINKS OVER NORTHERN UPR MICHIGAN THROUGH DAY ON TUESDAY...
SPREADING THE LES TO NW FLOW SNOW BELTS OF NORTHERN UPR MICHGAN...
ESPECIALLY BY TUESDAY NIGHT. SOUNDINGS SHOW INVERSIONS UP TO 6-8 KFT
IN WAKE OF THE TROUGH WITH AS H85 TEMPS DROP TO -25C BY DAYBREAK ON
WEDNESDAY. SETUP WILL THEN FAVOR A PUSH OF HEAVIER LES AS THE MAIN
COLD FRONT MOVES THROUGH TUESDAY NIGHT INTO WEDNESDAY MORNING WITH
CONDITIONS QUICKLY TRANSITIONING TO SMALL SNOWFLAKE/LOW VSBY LES
REGIME FOR THE NORTHWEST WIND SNOW BELTS WEDNESDAY AFTN INTO
WEDNESDAY NIGHT. BLYR WINDS INCREASE THROUGH WEDNESDAY TO 25-30 KTS
SO BLSN AND DRSN WILL ALSO BECOME A CONCERN IN OPEN AREAS NEAR LK
SUPERIOR AND ESPECIALLY WHERE ICE IS BUILT UP ALONG THE SHORELINE.
AWAY FM THE LES THE MAIN THEME WILL BE COLD. TEMPS ON WEDNESDAY WILL
ONLY STRUGGLE INTO THE SINGLE DIGITS ABOVE ZERO WITH WIND CHILL
READINGS 10 TO 20 BLO ZERO. AS TEMPS FALL OFF WELL BLO ZERO ON
WEDNESDAY NIGHT OVER WESTERN UPR MICHIGAN...MAY SEE WIND CHILL
READINGS MAY COME CLOSE TO ADVY INTO THURSDAY MORNING. WINDS WILL BE
SLACKENING BY THIS TIME THOUGH...ESPECIALLY OVER INTERIOR SECTIONS
OF CWA. A BIT OF MODERATION ON THURSDAY FOR HIGHS WITH READINGS
NEARING 10 DEGREES OR REACHING THE LOWER TEENS. BLYR WINDS BACK SW
LATER THURSDAY INTO THURSDAY NIGHT AS HIGH PRESSURE RIDGE SETTLES FM
THE MIDDLE MISSISSIPPI RIVER VALLEY TO THE OHIO VALLEY. EXPECT THE
LES TO SHIFT OFFSHORE BY THURSDAY NIGHT. SINCE UPPER LAKES WILL BE
AHEAD OF ANOTHER SFC TROUGH CROSSING SOUTH CENTRAL CANADA...EXPECT
CLOUDS TO BE ON THE INCREASE WITH EVEN A POSSIBILITY OF LGT SNOW OR
FLURRIES. THUS...TEMPS SHOULD NOT CRASH TOO MUCH ON THURSDAY NIGHT.
STRONGER COLD FRONT WITH ANOTHER PUSH OF COLDER AIR EXPECTED TO
ARRIVE FRIDAY NIGHT INTO SATURDAY. SHORTWAVE/CONVERGENCE ALONG THE
SFC-H85 FRONT AND UPPER DIVERGENCE ON NOSE OF H3 JET STREAK COMBINE
TO SPREAD SWATH OF SNOW OVER MOST OF UPR MICHIGAN FRIDAY AFTN INTO
FRIDAY EVENING. TIMING MAY SHIFT AROUND SOME THOUGH CONSIDERING THIS
SOLUTION IN THE MODELS IS NEWER DEVELOPMENT. LOW CHANCE POPS WILL
WORK FOR NOW WITH THE SNOW ALONG THE COLD FRONT AND THEN MORE LOW
CHANCE POPS FOR NEXT SATURDAY WITH DEVELOPING NE FLOW LES IN WAKE OF
THE FRONT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1226 PM EST SAT JAN 31 2015
AS THE COLD FRONT CONTINUES TO SAG TO THE SOUTH OF THE REGION THIS
AFTERNOON...WINDS HAVE TURNED TO THE NORTH TO NORTHWEST. CLOUD COVER
IS EXPECTED TO LINGER THROUGH THE TAF PERIOD AT EACH
SITE...HOWEVER...THE FOCUS OF THE LOW CLOUD COVER WILL SHIFT FROM THE
IWD AND CMX TAF SITES THIS AFTERNOON TO THE KSAW TAF SITE. THIS WILL
BE DO TO AN ADDITIONAL WIND SHIFT TO THE NORTH- NORTHEAST...ALLOWING
FOR FAVORED UPSLOPE/LAKE EFFECT CONDITIONS FOR KSAW. THE
NORTHEASTERLY WIND DIRECTION MAY ALLOW IWD TO SEE A REDUCTION IN LAKE
EFFECT SNOW SHOWERS TONIGHT INTO SUNDAY...THEREFORE HAVE INCREASED
THE VISIBILITY AND BUMPED THE CEILINGS UP SLIGHTLY. THIS MAY STILL
CHANGE AS THE EXACT WIND DIRECTION WILL IMPACT THE OVERALL CEILING
CONDTIONS AND LAKE EFFECT CHANCES AT IWD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 340 PM EST SAT JAN 31 2015
A COLD FRONT THAT SHIFTED SOUTH AND EAST OF THE AREA THIS AFTERNOON
ALONG WITH A DECENT PRESSURE GRADIENT ON THE BACK SIDE WILL ALLOW A
FEW GUSTS TO REACH 35KTS THIS AFTERNOON AND EVENING. MUCH LIGHTER
WINDS WILL PREVAIL SUNDAY AS HIGH PRESSURE DRIFTS ACROSS THE UPPER
GREAT LAKES REGION. LOW PRESSURE AND ASSOCIATED COLD FRONT WILL
APPROACH THE AREA MONDAY NIGHT AND THEN SWEEP THROUGH THE AREA
TUESDA NIGHT AND WEDNESDAY. ON THE BACK SIDE OF THIS SYSTEM...WINDS
WILL INCREASE FROM THE NORTHWEST WEDNESDAY AFTERNOON THROUGH
THURSDAY...WITH GALE FORCE GUSTS TO 35 KNOTS POSSIBLE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 5 AM EST SUNDAY FOR LSZ264-
266-267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KEC
LONG TERM...JLA
AVIATION...KEC
MARINE...KEC
AREA FORECAST DISCUSSION
NWS BILLINGS MT
326 PM MST SAT JAN 31 2015
.SHORT TERM...VALID FOR SUN AND MON...
SNOW THROUGH THIS EVENING IS THE MAIN SHORT TERM FORECAST CONCERN
AS ROADS WILL BE SLIPPERY IN PLACES...ESPECIALLY AFTER SUNSET.
SNOW RAPIDLY FILLED IN AND INTENSIFIED OVER MUCH OF SOUTHERN MT
EARLY THIS AFTERNOON AS THE PEAK OF THE FORCING TIED TO THE MID-
AND UPPER-LEVEL SHORTWAVE TROUGH BEGAN TO CROSS THE AREA. WE FEEL
THE SNOW WILL WIND DOWN DURING THE EVENING AS THAT FORCING EXITS
STAGE RIGHT INTO THE DAKOTAS...BUT RECENT HIGH-RESOLUTION MODEL
GUIDANCE AND THE COARSER 12 UTC GFS AND TO A LESSER EXTENT THE
ECMWF STILL SUPPORT EVENT TOTALS OF 1 TO 2 INCHES IN MANY SPOTS BY
EVENING. WE WERE SOMEWHAT CONCERNED ABOUT HIGHER-THAN-EXPECTED
SNOW TOTALS IN AND NEAR BILLINGS GIVEN RADAR TRENDS THROUGH 2130
UTC...WHICH HAD AN OROGRAPHIC SNOW BAND FROM LAVINA TO BROADVIEW
AND DOWNSTREAM TO THE METRO AREA. A MORE CONTEMPORARY TREND IN
RADAR DATA IS FOR THAT BAND TO DIMINISH THOUGH...WHICH IS A TREND
SUPPORTED BY THE DEPARTURE OF LARGER-SCALE FORCING ALOFT. WE HAVE
THUS STAYED THE COURSE WITH THE IDEA THAT TOTAL SNOW ACCUMULATION
IN BILLINGS WILL BE AN INCH OR LESS. AFTERNOON RADAR IMAGERY ALSO
ALSO SUPPORTED TODAY/S HRRR AND HIGH-RESOLUTION WRF-NMM AND WRF-
ARW RUNS FOR A MODEST UPSLOPE-AIDED ENHANCEMENT OF SNOW IN THE
RED LODGE FOOTHILLS WHERE WE ARE NOW CALLING FOR 2 TO 3 INCHES OF
SNOW THROUGH THIS EVENING.
DESPITE RELATIVELY LOW SNOW AMOUNTS PRECLUDING US FROM ISSUING ANY
HEADLINES FOR THIS EVENT...ROADS WILL BECOME SLIPPERY BY EVENING
IN AREAS WHERE THEY AREN/T ALREADY AS THE LACK OF SOLAR RADIATION
AFTER SUNSET WILL ALLOW ROAD SURFACES TO DROP BELOW FREEZING AND
ANY MOISTURE ON THEM TO FREEZE. THAT IS OUR MAIN FORECAST MESSAGE.
BY SUNDAY...FLOW ALOFT TURNS ANTICYCLONIC WHILE SHORTWAVE RIDGING
MOVES OVERHEAD AND THAT WILL LEAD TO A DRY DAY WITH HIGHS POSSIBLY
HELD A BIT LOWER THAN THEY WOULD BE OTHERWISE BY FRESH SNOW COVER.
THE 12 UTC MODEL SUITE REMAINED CONSISTENT IN SHOWING A WARM FRONT
MOVING EASTWARD ACROSS THE REGION SUNDAY NIGHT INTO MONDAY AND WE
ARE CARRYING SOME POPS IN THE FORECAST WITH THAT FEATURE...THOUGH
FORCING LOOKS WEAK AND WILL LIKELY BE GREATEST IN SOUTHEASTERN MT
TO THE EAST OF BILLINGS ON MONDAY MORNING WHERE WARM AIR ADVECTION
ALOFT WILL BE FOCUSED.
HIGHS MONDAY WILL JUMP BACK UP WELL INTO THE 40S F ON THE WARM
SIDE OF THAT FRONT IN SOUTH CENTRAL MT AND NORTH CENTRAL WY. ITS
PLACEMENT IS UNCLEAR THOUGH...AND BECOMES EVEN MORE UNCERTAIN COME
MONDAY NIGHT WHEN IT IS LIKELY TO WAFFLE BACK SOUTHWARD AGAIN /AT
LEAST BY THE 12 UTC GFS AND ECMWF...NOT THE NAM/. WE USED A BLEND
OF CONTINUITY AND THE FORMER TWO MODELS TO LEAVE SOME HIGH-CHANCE
TO LOW-END LIKELY POPS IN THE FORECAST BY LATE MONDAY NIGHT ACROSS
PARTS OF THE AREA SINCE THE FRONTAL ZONE COULD FAVOR PRODUCTION OF
SOME LIGHT SNOW. SCHULTZ
.LONG TERM...VALID FOR TUE...WED...THU...FRI...SAT...
DID MAKE SOME CHANGES TO THE EXTENDED FORECAST...AND THE
CONCENTRATION OF THESE WERE IN THE EARLIER PART OF THE PERIOD.
NORTHWEST FLOW IS PROGGED OVER THE AREA...WITH A STRONG SHORTWAVE
ROTATING INTO NORTH DAKOTA TUESDAY AND TUESDAY NIGHT. THIS WILL
PUSH A REINFORCING SHOT OF COLD AIR INTO THE AREA. MODELS HAVE
BACKED OFF SOME ON THE DEPTH OF THE COLD AIR AND THUS GUIDANCE WAS
WARMER. THE BULK OF THE COLDER AIR WAS SHOVED TO THE EAST. BUMPED
TEMPERATURES UP A BIT BASED ON BASED ON MODEL TRENDS FOR TUESDAY
AND MAINTAINED ON WEDNESDAY.
MODELS WERE DIFFERENT ON QPF SOLUTIONS AS THE GFS WAS WETTER
EARLIER THAN THE ECMWF AND THE ECMWF HOLDING ONTO PRECIPITATION
LONGER INTO WEDNESDAY. BUMPED POPS FOR TUESDAY AS LOOKS GOOD FOR
AN OVERRUNNING EVENT MONDAY NIGHT INTO TUESDAY NIGHT WITH A DECENT
BAROCLINIC ZONE INVOLVED AND SOME PACIFIC MOISTURE AVAILABLE.
SHOULD THE ECMWF VERIFY...MAY HAVE TO RAISE POPS INTO WEDNESDAY
AND THURSDAY WITH PERSISTENT MID LEVEL WARM ADVECTION. LEFT THE
REST OF THE FORECAST IN TACT AS AN UPPER RIDGE BUILDS IN FOR THE
END OF THE WEEK WITH WEAK ENERGY RIDING OVER THE TOP. WINDS COULD
BECOME STRONG AT LIVINGSTON AND NYE THURSDAY AND THURSDAY NIGHT AS
ENERGY FLATTENS THE RIDGE. TWH
&&
.AVIATION...
AREAS OF LIGHT SNOW WITH POCKETS OF MODERATE SNOW WILL CONTINUE
ACROSS MOST OF THE AREA THIS AFTERNOON. THE HEAVIER SNOW SHOWERS
WILL LOWER CONDITIONS TO IFR AND LIFR. THE SNOW WILL TAPER OFF
THIS EVENING...WITH THE SNOW TAPERING OFF SLOWER OVER SOUTHEAST
MONTANA AND ALONG THE EAST SLOPES. CONDITIONS WILL IMPROVE TO VFR
OVERNIGHT. MOUNTAINS WILL BE OBSCURED. TWH
&&
.PRELIMINARY POINT TEMP/POPS...
SUN MON TUE WED THU FRI SAT
-----------------------------------------------------------
BIL 014/031 029/046 028/030 015/033 026/045 036/053 038/056
60/B 21/E 55/J 52/J 21/B 01/N 11/N
LVM 016/040 031/049 035/035 021/039 029/049 036/054 039/055
40/B 31/N 44/W 43/W 21/E 11/N 21/N
HDN 012/030 023/043 024/028 008/032 018/043 030/051 030/054
80/B 22/S 55/J 42/J 21/B 01/B 11/B
MLS 007/023 020/034 018/019 000/023 012/038 025/046 027/052
91/B 24/O 65/J 20/B 11/B 11/B 12/W
4BQ 009/027 022/043 025/026 007/030 019/044 029/054 034/058
+1/B 23/O 54/J 31/B 11/B 01/B 12/W
BHK 005/018 013/032 016/016 000/020 012/036 025/045 028/050
+1/B 24/S 54/J 20/B 10/B 11/B 12/W
SHR 012/028 021/046 025/027 013/032 020/044 029/055 031/055
61/B 21/E 22/J 52/J 11/B 00/B 11/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
949 AM MST SAT JAN 31 2015
.UPDATE...
THE GOING FORECAST APPEARS TO BE ON TRACK...SO WE ONLY MADE A FEW
SMALL CHANGES WITH THIS UPDATE...NAMELY TO INCREASE POPS UP TO 100
PERCENT FROM MILES CITY TO BAKER THIS AFTERNOON AND TO INCREASE
POST-FRONTAL WIND SPEEDS A BIT IN MOST AREAS BASED ON THE OBSERVED
SURFACE PRESSURE RISES UPSTREAM AS OF 16 UTC. RADAR TRENDS SUPPORT
SNOW SPREADING SOUTH AND EAST THIS AFTERNOON AS MODEL GUIDANCE HAS
BEEN AND STILL IS SIMULATING...WITH THE GREATEST ACCUMULATIONS OF
AN INCH OR TWO IN SOUTHEASTERN MT WHERE QG-FORCING IS STRONGEST.
ONE ITEM THAT WE WILL BE INVESTIGATING FURTHER TODAY IS WHETHER OR
NOT THE FOOTHILLS LIKE RED LODGE AND FISHTAIL COULD GET MORE SNOW
THAN CURRENTLY FORECAST. RECENT HRRR RUNS SUPPORT ENOUGH QPF FOR A
COUPLE INCHES THERE...LIKELY IN PART BECAUSE THAT MODEL IS FED BY
THE GFS ON THE LARGE-SCALE AND THE GFS IS MORE SUPPORTIVE OF
UPSLOPE SNOW THAN ITS ECMWF GLOBAL COUNTERPART. WE WILL WATCH THE
OBSERVATIONAL TRENDS AND DIGEST ADDITIONAL MODEL GUIDANCE BEFORE
ADJUSTING THAT PART OF THE FORECAST BASED ON THOSE DISPARITIES.
SCHULTZ
&&
.SHORT TERM...VALID FOR TDY AND SUN...
COLD FRONT MOVING INTO NORTHERN MONTANA THIS MORNING BUT NOT VERY
ARCTIC LIKE WITH TEMPERATURES ONLY DOWN TO 18 DEGREES AT CALGARY.
HOWEVER ITS A BIG AIRMASS CHANGE FROM WE HAVE BEEN EXPERIENCING
AND TEMPERATURES WILL BECOME MUCH COLDER TODAY DURING THE
AFTERNOON HOURS. AHEAD OF THE FRONTAL ARRIVAL THERE IS A PATCH OF
STRATUS THAT IS TRYING TO PROGRESS INTO NORTHERN SECTIONS OF
SOUTHEAST MONTANA BUT CLOUD COVER IS CAUSING IT SLOW ITS MOVEMENT.
STILL EXPECT THIS STRATUS TO GET CLOSE TO A BAKER TO MILES CITY
LINE BY SUNRISE AND SOME PATCHES OF FREEZING FOG ARE EXPECTED.
FRONT WILL PROGRESS THROUGH THE AREA FROM NORTH TO SOUTH THROUGH
THE LATE MORNING AND EARLY AFTERNOON HOURS WITH ITS PROGRESS A BIT
FASTER THROUGH SOUTHEAST MONTANA. MODELS SHOW LIGHT SNOW
DEVELOPING MAINLY IN THE POST FRONTAL AREA IN SOUTHEAST MONTANA AS
SHORTWAVE ENERGY TRACKS OVER THE AREA LATER IN THE DAY. HRRR SHOWS
ANOTHER AREA OF SNOW DEVELOPING IN THE BILLINGS AREA AND LOCATIONS
30 MILES SOUTH AND WEST AS UPSLOPE PLAYS A FACTOR IN PROVIDING
LIFT. THIS WINDOW FOR SNOW ALREADY DISSIPATES BY MIDNIGHT AS
HEIGHTS BEGIN TO BUILD ALOFT AND THE COLD AIR PUSH BEGINS TO
TRANSLATE EAST. GIVEN THE SHORT WINDOW AND NOT A STRONG ALIGNMENT
FOR LIFT CONFIDENT SNOW AMOUNTS WILL BE LIGHT AND GENERALLY AROUND
AN INCH THOUGH A FEW LOCATIONS COULD SEE CLOSER TO 2. BIGGER
THREAT IS THE SNOW FALLING ON WARM ROADS AND MELTING AND FREEZING.
THIS STILL LOOKS REASONABLE ESPECIALLY IF A FEW HOURS OF SUNSHINE
OCCUR BEFORE THE FRONT. CURRENT IR IMAGERY INDICATES THIS IS
LIKELY ESPECIALLY FOR THE WESTERN HALF OF THE AREA.
TEMPERATURES WILL BE FALLING FROM THE MID TO UPPER 30S THIS
MORNING THROUGH THE 20S THIS AFTERNOON. LOWS WILL SETTLE IN THE 5
TO 15 DEGREE RANGE OVERNIGHT. COLD BY COMPARISON TO THIS PAST WEEK
BUT NOT DRAMATIC FOR JANUARY.
SUNDAY THE AIRMASS MODERATES AS THE DEEPER COLD AIR MOVES AWAY
FROM THE REGION WITH A WARM FRONT MOVING INTO THE WESTERN ZONES BY
LATE AFTERNOON AND ACROSS THE AREA SUNDAY NIGHT. MOST OF THE DAY
WILL BE DRY BUT THE WARM FRONT DOES INCREASE MOISTURE OVER THE
WESTERN ZONES WHICH WILL BRING A CHANCE FOR MOUNTAINS SNOW. BORSUM
.LONG TERM...VALID FOR MON...TUE...WED...THU...FRI...
LITTLE IN THE WAY OF CHANGES TO THE EXTENDED FORECAST PERIOD...AS
THE OVERALL STORY REMAINS THE SAME. COLDER AND UNSETTLED WEATHER
TO START THE WORK WEEK...WITH A RETURN TO ABOVE SEASONAL AVERAGE
TEMPERATURES TO END THE WEEK.
MODELS CONTINUE TO HAVE TIMING DIFFERENCES FOR ARCTIC
INTRUSION...BUT GENERAL CONSENSUS POINTS TOWARD BEST PRECIP
POTENTIAL ON TUESDAY AFTERNOON/EVENING. ONE TREND THAT SEEMS TO
PERSIST OVER THE PAST FEW MODEL RUNS IS A LOWER QPF TYPE
EVENT...FOR BOTH THE GFS AND THE ECMWF...SO HEAVY SNOW IS
LESS LIKELY.
UPPER LEVEL RIDGING BEGINS PUSHING INTO THE REGION WEDNESDAY
NIGHT INTO THURSDAY MORNING. THE RIDGE DOMINATES THE PATTERN
THROUGH THE REMAINDER OF THE PERIOD...KEEPING GENERALLY DRY
CONDITIONS IN PLACE. THERE DO APPEAR TO BE SEVERAL SHORTWAVES
SLIPPING THROUGH THE FLOW HOWEVER...BRINGING PERIODIC POTENTIAL
FOR MOUNTAIN SHOWERS THROUGH THE PERIOD. A STRONGER WAVE PUSHES
INTO THE REGION SATURDAY...WITH PLENTY OF ASSOCIATED PACIFIC
MOISTURE...WHICH SHOULD BRING SHOWERS ACROSS THE REGION. AAG
&&
.AVIATION...
A COLD FRONT WILL MARCH THROUGH THE AREA THIS MORNING. THIS FRONT
WILL PRODUCE NORTH TO NORTHEAST WINDS...WITH SOME GUSTS TO 20KTS
IN THE FIRST FEW HOURS OF PASSAGE. THE FRONT WILL ALSO DRAG SOME
LOW STRATUS AND FOG INTO EASTERN SECTIONS IMPACTING KMLS AND KBHK
WITH OCCASIONAL IFR AND LIFR CONDITIONS. SOME LIGHT FREEZING
DRIZZLE IS POSSIBLE EAST OF KBIL THIS MORNING AS THE FRONT MOVES
IN TOO. LIGHT SNOW WILL DEVELOP BY THIS AFTERNOON OVER THE AREA
WITH SOME CONDITIONS LOWERING TO IFR...ESPECIALLY EAST OF KBIL AND
ALONG THE EAST SLOPES. MOUNTAINS WILL BE OBSCURED. THE SNOW WILL
TAPER OFF THIS EVENING. TWH
&&
.PRELIMINARY POINT TEMP/POPS...
TDY SUN MON TUE WED THU FRI
-------------------------------------------------------
BIL 037 014/032 029/045 028/028 012/028 021/043 033/053
6/S 71/E 23/W 55/J 42/J 21/B 11/N
LVM 039 016/038 032/047 034/040 020/035 026/046 034/055
2/O 51/N 33/W 46/J 42/J 21/B 11/N
HDN 036 010/030 024/043 024/028 006/026 015/041 026/051
6/S 61/B 23/W 55/J 41/B 21/B 11/B
MLS 029 007/024 020/035 018/019 000/019 009/035 023/047
+/S 61/B 24/J 55/J 21/B 11/B 11/B
4BQ 041 009/028 022/043 025/029 007/023 016/042 027/055
3/O 71/B 23/W 34/J 41/B 11/B 11/B
BHK 025 003/020 015/033 016/019 901/014 005/034 022/046
+/S 81/B 24/J 54/J 21/B 11/B 11/B
SHR 039 011/029 021/044 025/036 009/030 015/042 026/053
1/N 31/B 22/W 25/J 52/J 21/B 11/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS GLASGOW MT
928 AM MST SAT JAN 31 2015
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH MONDAY...
SHORT TERM MODELS APPEAR TO HAVE AN EXCELLENT HANDLE ON THE
DEVELOPMENT OF SNOW OVER THE AREA WITH HRRR FORECASTS MATCHING THE
REFLECTIVITY PATTERN QUITE WELL. HEAVIEST PERIOD OF SNOW WILL LAST
THROUGH 20Z WITH LIGHTER MORE SCATTERED AMOUNTS TRAILING OFF
THROUGH 12Z TOMORROW. SNOW AMOUNTS HAVE BEEN AROUND AN INCH SO FAR
BUT BLOWING SNOW HAS REDUCED VISIBILITY DOWN TO 1/4 MILE IN PLACES.
COLD AND WIND HAS GENERATED SMALL DRY SNOW PARTICLES WHICH WILL
BLOW AND DRIFT DURING THE DAY. TEMPERATURES WILL CONTINUE TO
DECLINE THROUGH THE DAY REACHING SINGLE DIGITS BY SUNDAY MORNING.
UPDATED FORECAST FOR WINDS AS OBSERVATIONS HAVE BEEN RUNNING A
LITTLE HIGH. MARTIN
PREVIOUS DISCUSSION...
LOW CLOUD AND FOG SPREADING SOUTHWEST ACROSS THE REGION. SHORTWAVE
PUSHING INTO NORTH CENTRAL MONTANA WITH SNOW STILL NORTH OF THE
CANADIAN BORDER. AS THE WAVE TRACKS THROUGH THE STATE TODAY...SNOW
WILL SPREAD SOUTHWARD...DISSIPATING THE FOG ALTHOUGH VISIBILITY
WILL REMAIN LOW WITH THE FALLING SNOW. ENOUGH GRADIENT WIND TO
PRODUCE SOME DRIFTING SNOW THIS AFTERNOON...BEFORE DIMINISHING
THIS EVENING. SNOWFALL ALSO EXPECTED TO TAPER OFF THROUGH THE
NIGHT. CURRENT ADVISORY STILL LOOKS ON TRACK WITH 2 TO 3 INCHES OF
SNOW EXPECTED TODAY...WITH AN ADDITIONAL INCH OR TWO TONIGHT.
COLD AIR LINGERS INTO SUNDAY AS CANADIAN HIGH SLIDES THROUGH THE
NORTHERN PLAINS. WEAK SHORTWAVE DROPPING THROUGH THE STATE SUNDAY
NIGHT SHIFTS ARCTIC BOUNDARY ACROSS CENTRAL MONTANA AND COULD
PRODUCE A LITTLE OVERRUNNING SNOW ON MONDAY MORNING. EBERT
.LONG TERM...MONDAY NIGHT THROUGH SATURDAY...
THE EXTENDED FORECAST PERIOD BEGINS WITH NORTHWEST FLOW ALOFT OVER
NORTHEAST MONTANA. THERE WILL BE A MODERATE RIDGE OFF THE WEST
COAST AND AN ARCTIC LOW CENTERED OVER HUDSON BAY BUT WITH A
MASSIVE COLD AIR MASS SPREAD OVER MOST OF CANADA. A WAVE MOVING
AROUND THE WESTERN SIDE OF THE LOW SENDS A COLD FRONT FURTHER
SOUTH INTO THE LOCAL REGION. A QUICK-MOVING SHORT-WAVE CROSSES
THE DIVIDE AND BECOME THE FOCUS OF PRECIPITATION MONDAY NIGHT AND
TUESDAY. AN INVERTED SURFACE TROUGH SUGGESTS QPF OF GREATER THAN
0.10 INCH. WX TYPE WILL LIKELY BE ALL SNOW...BUT THERE ARE HINTS
IN THE MODEL THAT SOME COULD BE IN THE FORM OF FREEZING RAIN MIXED
IN AT TIMES. MODEL QPF PRODUCES AROUND 3-4 INCHES OF SNOW FOR
TUESDAY. SO THIS IS A STORM TO WATCH.
A SURFACE HIGH SLIDES INTO THE AREA TUESDAY EVENING TO CUT OFF ANY
REMAINING SNOW. NEMONT WILL REMAIN ON THE COLD SIDE OF THE
STATIONARY BOUNDARY WITH MODIFIED ARCTIC AIR THAT WILL KEEP
TEMPERATURES SOMEWHERE NEAR NORMAL THROUGH THURSDAY. THEN AN UPPER
RIDGE AXIS MOVES ACROSS THE DIVIDE TO BRING A WARM FRONT THROUGH
NEMONT WHICH WILL RAISE TEMPERATURES ABOVE NORMAL FOR FRIDAY AND
SATURDAY. WHAT IS UNCERTAIN IS WHETHER OR NOT A DISTURBANCES RUNS
THROUGH THE REGION AFTER IT WARMS. THE GFS IS MORE ROBUST WITH A
WAVE THAN THE EC. SO THERE COULD BE SOME MIXED PRECIPITATION BY
THE WEEKEND. SCT
&&
.AVIATION...
AN UPPER LEVEL TROUGH MOVES EAST THROUGH THE AREA TODAY AS A COLD
FRONT DESCENDS SOUTH FROM CANADA BRINGING SNOW AND LOW CLOUDS FOR
IFR/LIFR CEILINGS AND VISIBILITIES AS LOW AS ONE-QUARTER MILE AT
TIMES. AIRPORT MINIMUMS ARE MOST LIKELY THIS MORNING THROUGH THIS
AFTERNOON. STRONG EASTERLY TO NORTHEASTERLY WINDS WILL BEGIN TO
TAPER OFF LATE IN THE DAY. WIND WILL EASILY GENERATE AREAS OF
BLOWING SNOW. EXPECT CONDITIONS TO IMPROVE BY SUNDAY MORNING.
BMICKELSON
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 5 AM MST SUNDAY FOR CENTRAL AND
SOUTHEAST PHILLIPS...CENTRAL AND SOUTHERN VALLEY...DANIELS...
DAWSON...EASTERN ROOSEVELT...GARFIELD...MCCONE...NORTHERN
PHILLIPS...NORTHERN VALLEY...PRAIRIE...RICHLAND...SHERIDAN...
SOUTHWEST PHILLIPS...WESTERN ROOSEVELT...WIBAUX.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
325 PM CST SAT JAN 31 2015
.SHORT TERM...(TONIGHT THROUGH TUESDAY)
ISSUED AT 325 PM CST SAT JAN 31 2015
SNOW AND HEADLINES ARE THE MAIN PROBLEMS IN THE SHORT TERM AND HAVE
KEPT PRIMARY FOCUS IN THE NEXT 24-30 HOURS.
A 90 KNOT JET MAX WAS ON THE FRONT SIDE OF THE TROUGH ACROSS THE
SOUTHWEST US AT 12Z. ANOTHER AREA OF STRONG WINDS AT 300 MB WAS FROM
NORTHERN MINNESOTA INTO THE OHIO VALLEY. LATEST WATER VAPOR IMAGERY
AND RECENT RAP MODEL INITIALIZATIONS SHOW A CLOSED LOW DROPPING
SOUTHWARD ACROSS BAJA. A MID LEVEL TROUGH WAS LOCATED FROM WESTERN
NEBRASKA INTO EASTERN COLORADO AND ANOTHER WAVE WAS DROPPING
SOUTHEAST FROM MONTANA. A 12 HOUR 500 MB HEIGHT FALL MAX OF ABOUT
130 METERS WAS OVER MONTANA AND ANOTHER AROUND 100 METERS WAS NEAR
THE MEXICO/NEW MEXICO BORDER. SO THIS IS A FAIRLY COMPLEX SETUP...
WITH SOME PHASING OF THE NORTHERN AND SOUTHERN STREAMS EXPECTED
TONIGHT.
MOISTURE HAS BEEN RETURNING OVER THE CENTRAL PLAINS WITH AREAS OF
SNOW OR A MIX OF RAIN AND SNOW. WILL MAKE SOME MINOR CHANGES TO
HEADLINES...ADDING A FEW COUNTIES TO THE WARNING IN THE NORTH.
IMPRESSIVE MOISTURE (850-700 MB SPECIFIC HUMIDITY VALUES 3-4 G/KG
AT 6 PM THIS EVENING...FALLING TO 2-3 G/KG BY 12Z SUNDAY) ALONG
WITH GOOD FORCING SHOULD ALLOW FOR SNOW AMOUNTS FROM ABOUT 4 TO 9
INCHES IN MOST OF THE FORECAST AREA. HIGHEST SNOW AMOUNTS EXPECTED
NORTH AND EAST. AS COLDER AIR SINKS IN FROM THE NORTH BEHIND THE
COLD FRONT (WHICH EXTENDED FROM WISCONSIN BACK INTO SOUTHWEST
NEBRASKA EARLY THIS AFTERNOON)...TEMPERATURES WILL FALL AND ROADS
WILL START TO ICE UP/BECOME SNOW COVERED AND SLICK. TEMPERATURES
SHOULD START SLIDING TONIGHT AND CONTINUE TO DROP THROUGH MUCH OF
THE DAY SUNDAY. STRONG NORTH SURFACE WINDS WILL LIKELY ALSO CAUSE
SOME BLOWING SNOW LATER TONIGHT AND AT LEAST THROUGH EARLY SUNDAY
AFTERNOON.
HEADLINES WILL CONTINUE UNTIL 6 PM SUNDAY IN NEBRASKA AND UNTIL 9 PM
SUNDAY IN SOUTHWEST IOWA. IT IS POSSIBLE THESE MAY BE CANCELLED
EARLIER THAN THAT...BUT THAT IS WHAT WE WILL GO WITH FOR NOW.
SNOW AMOUNTS WILL DECREASE THROUGH THE DAY AS DRIER AIR MOVES IN
FROM THE WEST AND LIFT PULLS OUT OF THE REGION. HIGH PRESSURE AT
THE SURFACE BUILDS IN FOR SUNDAY NIGHT. WINDS WILL DECREASE AND
WITH CLEARING SKIES HAVE LOWS FALLING OR AROUND ZERO...OR EVEN
BELOW ZERO IN OUR NORTHERN COUNTIES. WARM AIR ADVECTION AND SOUTH
WINDS SHOULD INCREASE MONDAY. KEPT A SMALL CHANCE OF SNOW NORTH
AND NORTHEAST OF OMAHA...BUT NOT A BIG DEAL. A SLIGHTLY BETTER
CHANCE OF SNOW ARRIVES FOR TUESDAY. 12Z GFS SEEMED A BIT TOO HIGH
ON QPF TUESDAY...BUT WILL SEE HOW THINGS TREND NEXT FEW MODEL
RUNS.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 325 PM CST SAT JAN 31 2015
LOOK FOR MODERATING TEMPERATURES THIS PERIOD. FAST WEST/NORTHWEST
MID LEVEL FLOW WILL OCCUR EARLY...WITH A RIDGE DEVELOPING OVER THE
WESTERN US. THIS RIDGE SHOULD BUILD EAST THROUGH THE WEEK. HIGHS
WILL BE 20S WEDNESDAY AND THURSDAY RISING TO ABOVE NORMAL FOR
FRIDAY AND SATURDAY. THERE IS SOME CHANCE OF LIGHT SNOW WEDNESDAY
OTHERWISE IT SHOULD BE MAINLY DRY.
&&
.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1142 AM CST SAT JAN 31 2015
IFR CIGS HAVE SETTLED IN AT ALL THREE TAF SITES AS OF 18Z AND
WILL LIKELY REMAIN SO FOR MUCH OF THIS FORECAST PERIOD. EXPECT
LIFR CIGS FROM TIME TO TIME AT KOMA AND KLNK ALREADY. LOOK FOR
LIGHT RAIN TO MOVE INTO THE KOFK AREA AFTER 19Z WHILE A RAIN SNOW
MIX WILL CONTINUE AT KOMA AND A BETTER CHANCE OF MOSTLY RAIN SNOW
MIX WILL CONTINUE AT KOMA. ALL SNOW HAS BEEN OCCURRING AT KLNK
BUT EXPECT A CHANGE BACK TO A RAIN SNOW MIX AFTER 22Z. THEN
OVERNIGHT...IN THE 02Z TO 04Z TIME RANGE...LOOK FOR CHANGEOVER TO
ALL SNOW. HAVE BROUGHT IN PERIODS OF MODERATE SNOW WITH VISBY DOWN
TO 1/2 SM AFTER 04Z. AFTER 11Z WINDS WILL HAVE SHIFTED TO THE
NORTH AND WILL GUST TO 30KT OR BETTER. SNOW WILL TAPPER OFF AND
BECOME LIGHTER IN NATURE...BUT COMBINED WITH BLOWING AND DRIFTING
SNOW AFTER 12Z.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 PM CST
SUNDAY FOR NEZ011-016-017-030>033-042>045-050>053-065>068-
078-088>093.
WINTER STORM WARNING FROM 6 PM THIS EVENING TO 6 PM CST SUNDAY
FOR NEZ012-015-018-034.
IA...WINTER STORM WARNING FROM 6 PM THIS EVENING TO 9 PM CST SUNDAY
FOR IAZ043-055-056-069-080-091.
WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 PM CST
SUNDAY FOR IAZ079-090.
&&
$$
SHORT TERM...MILLER
LONG TERM...MILLER
AVIATION...MEYER
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1134 AM CST SAT JAN 31 2015
.SYNOPSIS...
ISSUED AT 357 AM CST SAT JAN 31 2015
HIGH PRESSURE IS RIDGING SOUTH FROM MANITOBA INTO NORTH DAKOTA WHILE
LOW PRESSURE EXTENDS FROM AZ INTO COLORADO. A GOOD FETCH OF PACIFIC
MOISTURE AS WELL AS MODIFIED GULF MOISTURE IS BEING DRAWN
NORTHWARD AHEAD OF THE LOW PRESSURE...RESULTING IN OVERCAST SKIES
AND STRATUS INTO SOUTHERN NEBRASKA. SOME LIGHT RAIN OR RAIN/SNOW
MIXED IS WORKING INTO SOUTH CENTRAL NEBRASKA AND A SMALL PART OF
SWRN NEBR ATTM. TEMPERATURES HOLDING IN THE 30S ACROSS MOST OF
NEBRASKA.
&&
.UPDATE...
ISSUED AT 1130 AM CST SAT JAN 31 2015
A BAND OF SNOW...LOCALLY AND BRIEFLY MIXED WITH RAIN...HAS
DEVELOPED ACROSS PORTION OF THE SANDHILLS. THE BAND IS LIFTING TO
THE NORTH SLOWLY. THE LATEST HRRR DIMINISHES THIS BAND OVER THE
NEXT FEW HOURS THEN DEVELOPS THE MAIN BAND ACROSS NORTHERN
NEBRASKA LATER THIS AFTERNOON. THERE IS A POCKET OF DRY AIR IN THE
WATER VAPOR WHICH SHOULD BE ENOUGH TO DIMINISH THE CURRENT BAND.
THE 12Z MODELS DO AGREE IN DEVELOPING THE MAIN BAND ACROSS
NORTHERN NEBRASKA AND A FEW...ESPECIALLY THE NAM...HAS INCREASED
THE QPF AMOUNTS. THE GFS AND THE MAJORITY OF THE SHORT TERM MODELS
ARE NOT DEVELOPING AS MUCH AS THE NAM...HOWEVER THEY HAVE
INCREASED THE START TIME AND EXPANDED THE BAND FURTHER WEST...THUS
FELT IT WAS WARRANTED TO EXPAND THE ADVISORY WESTWARD AND START IT
EARLIER...21Z.
MAJOR CONCERN IS ABOUT THE QPF AMOUNTS /SNOW TOTALS WITH THIS
SYSTEM. WILL CONTINUE TO MONITOR CLOSELY THE SHORT TERM MODEL
UPDATES AND THE 18Z NAM RUN. SNOW TOTALS CURRENTLY EXPECTED ARE
GENERALLY A 3 TO 6 INCH BAND IN THE ADVISORY...WHICH MAY BE
CONSERVATIVE. IF THE NAM VERIFIES...AN UPGRADE TO A WARNING WOULD
BE NEEDED.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 357 AM CST SAT JAN 31 2015
THE LOW PRESSURE SYSTEM ACROSS THE DESERT SOUTHWEST WILL BE DRAWN
INTO KANSAS AND NEBRASKA TODAY AS A NRN STREAM TROUGH MOVES INTO
THE NRN PLAINS. THIS WILL CAUSE AN H7 LOW TO DEVELOP INTO CENTRAL
NEBRASKA BY 18Z. ISENTROPIC UPGLIDE WILL INCREASE TODAY WITH A
TROWAL TO DEVELOP ACROSS THE NEBRASKA SANDHILLS ON THE NWRN
PERIPHERY OF THE H7 LOW. MODEL ARE ALL IN GOOD AGREEMENT WITH THE
PLACEMENT AND TIMING OF THIS FEATURE. SOUNDINGS SHOW A DRY LAYER
NEAR 600MB WHICH WILL LIMIT PRECIP INITIALLY FROM REACHING THE
GROUND. ISENTROPIC LIFT SHOULD BE ABLE TO SATURATE THE LAYER BY
18Z. HAVE SUBSTANTIALLY INCREASED POPS TO LIKELY ACROSS THE
CENTRAL SANDHILLS AND DEFINITE BY LATE AFTERNOON.
ANOTHER CONCERN WILL BE PRECIP TYPE. COOLER AIR FROM THE NORTHERN
SYSTEM DRIFTS SOUTH...WHICH MODELS ARE IN AGREEMENT. KEPT MENTION AS
RAIN OR SNOW THIS MORNING...THEN TO ALL SNOW BY MID AFTERNOON
CENTRAL AND NORTHERN AREAS. A CHANGEOVER COULD OCCUR SOONER. ACROSS
THE SOUTH KEPT MENTION AS RAIN OR SNOW THROUGH THE AFTERNOON.
TEMPERATURES SHOULD REACH TO UPPER 30S TO NEAR 40 SOUTHWEST...WHILE
FALLING INTO THE UPPER 20S MUCH OF THE NCTRL IN THE AFTN DUE TO
DYNAMIC COOLING AND COOLER AIR DROPPING SOUTH. SNOW ACCUMULATIONS OF
1 TO 2 INCHES AND LOCALLY HIGHER ARE POSSIBLE ACROSS THE SANDHILLS
THIS AFTERNOON...WHILE LITTLE OR NO ACCUMULATIONS EXPECTED IN THE
SOUTH.
HEAVIEST ACCUMULATIONS WILL BE TONIGHT ACROSS NCTRL
NEBR...ESPECIALLY EAST OF VALENTINE TO BREWSTER WHERE TOTAL
AMOUNTS OF 3 TO 5 INCHES AND LOCALLY HIGHER ARE POSSIBLE. THE
TROWAL SHOULD REMAIN WELL DEFINED TONIGHT...ENHANCED BY THE
APPROACHING NRN STREAM TROUGH. NORTH WINDS INCREASING TO 15 TO 25
MPH LATE THIS EVENING AND OVERNIGHT EAST OF HWY 83 COULD CAUSE
SOME BLOWING AND DRIFTING WITH REDUCED VISIBILITIES...ESPECIALLY
EAST OF VALENTINE TO BREWSTER. THEREFORE...HAVE ISSUED A WINTER
WEATHER ADVISORY IN EFFECT TONIGHT FOR KEYA
PAHA...BOYD...ROCK...HOLT...GARFIELD AND WHEELER COUNTY. WILL NEED
TO MONITOR DEVELOPMENT OF HEAVIER SNOW BANDS THIS AFTERNOON AND
EVENING...WITH ADJACENT COUNTIES WESTWARD POSSIBLY SEEING HIGHER
AMOUNTS AS WELL. MUCH COLDER AIR WILL BE DRAWN IN TONIGHT WITH
LOWS 8 TO 12 ABOVE ACROSS NCTRL NEBR...15 TO 20 SWRN NEBR.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 357 AM CST SAT JAN 31 2015
FORECAST CONCERNS FOR THE FIRST PORTION OF THE PERIOD LIE WITH
EXITING SNOW CHANCES ON SUNDAY AND TEMPERATURES IN THE WAKE OF THE
SYSTEM FOR SUNDAY AND MONDAY. THE REMAINDER OF THE FORECAST PERIOD
DEALS WITH FAIRLY QUICK NORTHWEST TO QUASI-ZONAL FLOW...LEADING TO
DIFFICULTIES IN TIMING OF INDIVIDUAL SHORTWAVE TROUGHS INVOLVING
TEMPERATURE VARIATIONS AND CHANCES FOR PRECIPITATION.
CURRENTLY...THE HIGHEST CHANCES FOR PRECIPITATION WILL COME
TUESDAY NIGHT AND WEDNESDAY.
THE MODELS ARE IN DECENT AGREEMENT THROUGH THE PERIOD WITH THE
GENERAL PATTERN...BUT DO HAVE SLIGHT DIFFERENCES IN TIMING
PARTICULAR SYSTEMS...WHICH IS EXPECTED IN THIS FLOW REGIME.
FOR SUNDAY AND INTO MONDAY...THE SYSTEM IMPACTING THE AREA TODAY
WILL BE EXITING THE REGION AS THE UPPER LEVEL TROUGH PUSHES INTO
THE MIDDLE MISSISSIPPI RIVER VALLEY REGION. THE COLD FRONT WILL BE
WELL PAST THE AREA BY 12Z SUNDAY AND THE COLD AIR BEHIND IT WILL
BE IN PLACE WITH 850MB TEMPERATURES FROM -10C TO-18C. MODELS ARE
SHOWING GOOD SUBSIDENCE BEHIND THE SHORTWAVE AND WITH A TIGHT
PRESSURE GRADIENT LOOKING FOR BREEZY WINDS...AND WITH THE BOUNDARY
LAYER TO MIXING THROUGH THE DAY COULD GET GUSTS TO 30-35KTS. BY
MID AFTERNOON ALL OF THE SNOW SHOULD BE OUT OF THE AREA. ONE OTHER
MINOR CONCERN IS CHANCES FOR SOME LIGHT SNOW OVER THE EASTERN
PANHANDLE. MODELS ARE INDICATING THERE WILL BE SOME WEAK TO
MODERATE LIFT AS A SECONDARY PV ANOMALY MOVES SOUTH ACROSS THE
AREA. MOISTURE WILL BE WANING THROUGH THE MORNING BUT COULD GET
ENOUGH LIFT...ESPECIALLY OVER THE HIGHER TERRAIN TO INDUCE SOME
LIGHT SNOW. AS FOR TEMPERATURES...WITH THE COLD AIRMASS EXPECTED
LOOKING AT BELOW NORMAL TEMPERATURES. THE NORTHEAST HALF OF THE
FORECAST AREA WILL SEE CLOUDS HANG ON THROUGH MUCH OF THE DAY
WHICH WILL ALSO LIMIT THE TEMPERATURE RISE...WITH HIGHS IN THE LOW
TO MID TEENS. TO THE SOUTHWEST...WHERE MORE SUNSHINE AND DEEPER
MIXING IS EXPECTED...BELIEVE HIGHS IN THE MID TO UPPER 20S ARE
APPROPRIATE.
HIGH PRESSURE AT THE SURFACE SLIDES EAST ACROSS THE FORECAST AREA
SUNDAY NIGHT...BUT BY 12Z MONDAY MORNING IS OFF TO THE EAST WITH
SOUTHERLY RETURN FLOW TAKING OVER. THIS MAY LEAD TO A NON-DIURNAL
TEMPERATURE CURVE OVERNIGHT AS TEMPERATURES WILL LIKELY DROP
QUICKLY AS THE HIGH MOVES OVERHEAD WITH CLEAR SKIES AND LIGHT
WINDS.
ON MONDAY...THE MODELS ARE SHOWING A WEAK SHORTWAVE TROUGH MOVING
ACROSS THE DAKOTAS AND NORTHEAST NEBRASKA IN THE NORTHWEST FLOW.
THIS SYSTEM WILL BRING A WARM FRONT ACROSS THE AREA...WHILE THE
MAJORITY OF THE MODELS ARE KEEPING ANY CHANCES FOR PRECIPITATION
TO THE NORTHEAST OF THE AREA. KEPT THE FORECAST DRY BUT MAY NEED
TO WATCH HOW THIS SYSTEM PROGRESSES OVER THE WEEKEND AS EVEN A
SLIGHTLY MORE AMPLIFIED SYSTEM WOULD LIKELY BRING CHANCES FOR
PRECIPITATION TO PORTIONS OF THE AREA. TEMPERATURES WILL BE A BIT
WARMER FOR MONDAY AND TUESDAY WITH TUESDAY LOOKING TO BE WELL
ABOVE NORMAL FOR PORTIONS OF THE FORECAST AREA. THIS WILL OCCUR
AHEAD OF THE NEXT SYSTEM THAT WILL MOVE ACROSS THE REGION. THE
MODELS ARE IN GOOD AGREEMENT WITH AN UPPER LEVEL SYSTEM COMING OUT
OF NORTHWEST CANADA AND DROPPING THROUGH THE NORTHERN PLAINS LATER
TUESDAY AND WEDNESDAY. THE COLD FRONT IS CURRENTLY TIMED TO PUSH
THROUGH THE FORECAST AREA TUESDAY AFTERNOON. AHEAD OF THE
FRONT...TEMPERATURES SHOULD RISE SIGNIFICANTLY...WITH UPPER 50S
AND 60S POSSIBLE. ACROSS THE NORTH...WHERE THE COLDER AIR MOVES IN
EARLIER...HIGHS MAY BE LIMITED TO 40S...WITH STEADY OR FALLING
TEMPERATURES THROUGH THE AFTERNOON. SNOW CHANCES WILL COME BEHIND
THE PASSAGE OF THE FRONT AS MOISTURE AND LIFT WILL BE LACKING
IMMEDIATELY FOLLOWING. THIS HAS MUCH TO DO WITH THE UPPER JET...AS
IT IS BASICALLY NON-EXISTENT OVER THE REGION UNTIL TUESDAY NIGHT
AND WEDNESDAY. THE FORECAST WILL CONTINUE CHANCES FOR SNOW FOR
TUESDAY NIGHT AND WEDNESDAY...HOWEVER ANY AMOUNTS ARE UNCERTAIN AT
THIS TIME. COLDER TEMPERATURES ARE EXPECTED WITH THIS SYSTEM...BUT
THE MODELS ARE IN GOOD AGREEMENT WITH BUILDING A RIDGE IN OVER THE
ROCKIES AND PLAINS BY THE WEEKEND SO IF THE TREND CONTINUES...NEAR
OR ABOVE NORMAL TEMPERATURES WOULD BE EXPECTED INTO NEXT WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1130 AM CST SAT JAN 31 2015
COMPLEX AVIATION WEATHER THE NEXT 24 HOURS. A LOW PRESSURE SYSTEM
WILL MOVE ACROSS THE PLAINS WITH WIDESPREAD IFR CONDITIONS.
PLENTIFUL LOW LEVEL MOISTURE WILL RESULT IN MOST AREAS SEEING IFR
CLOUDS INTO TONIGHT...THEN LIFTING OVERNIGHT INTO TOMORROW
MORNING TO MVFR. ALSO EXPECT SNOW TO DEVELOP AND REDUCE
VISIBILITIES TO 3 MILES OR LESS AT TIMES. IN ADDITION TO THE SNOW
WILL BE GUSTY NORTHERLY WINDS /GUSTS 20 TO 30 KTS/ DEVELOPING LATE
TONIGHT INTO THE MORNING HOURS. THIS COULD RESULT IN LOCAL AREAS
OF BLOWING SNOW...HOWEVER UNCERTAIN ABOUT SNOW TOTALS AT THE
TERMINALS RESULTED IN NO BLSN IN THE TAF AT THIS TIME.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 3 PM CST /2 PM MST/ THIS AFTERNOON
TO 6 AM CST /5 AM MST/ SUNDAY FOR NEZ005>010-023>029-094.
&&
$$
UPDATE...MASEK
SYNOPSIS...ROBERG
SHORT TERM...ROBERG
LONG TERM...BROOKS
AVIATION...BROOKS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
252 PM CST SAT JAN 31 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 245 PM CST SAT JAN 31 2015
.SHORT TERM...TONIGHT AND SUNDAY...
MAIN ISSUED THIS FORECAST PERIOD WILL BE SNOW POTENTIAL THIS
AFTERNOON AND EVENING. SNOW IS STILL FORECAST TO REMAIN BELOW
ADVISORY CRITERIA WITH FAIRLY WIDESPREAD SNOW AMOUNTS OF 3 INCHES
ACROSS WEST CENTRAL ND THIS AFTERNOON WITH 2 TO 3 INCHES SPREADING
INTO THE SOUTH CENTRAL TONIGHT. AN ISOLATED 4 INCH AMOUNT IS
POSSIBLE BUT NOT WIDESPREAD. THEN WIND CHILLS BECOME A CONCERN
ACROSS THE NORTH CENTRAL THROUGH THE NORTHERN JAMES RIVER VALLEY
TONIGHT INTO SUNDAY MORNING. LATEST RADAR TRENDS SHOW THE SNOW THIS
AFTERNOON IS CONCENTRATED ACROSS THE WEST CENTRAL WHERE UP TO 3
INCHES MAY FALL BY EARLY EVENING. THEN THIS EVENING THEN SNOW WILL
BE FOCUSED ALONG AN H300 JET REGION WHICH EXTENDS NORTHEAST TO
SOUTHWEST ACROSS WESTERN NORTH DAKOTA. THE LATEST HRRR RUNS FOLLOW
THE JET DYNAMICS AND FORM A SNOW BAND THAT EXTENDS FROM SOUTHWEST
NORTH DAKOTA INTO THE SOUTH CENTRAL BETWEEN 00Z-06Z. BELIEVE THERE
WILL ANOTHER 3 INCH BAND OF SNOW FROM BOWMAN NORTHEAST TO BISMARCK.
THE MOST RAPIDLY CHANGING WEATHER WILL BE FOUND SOUTH CENTRAL WHERE
THE PARTLY SUNNY SKIES THIS AFTERNOON WILL QUICKLY CHANGE TO SNOW.
BUFKIT SOUNDINGS FROM DICKINSON TO BISMARCK THIS EVENING SHOW A
FAIRLY DEEP DENDRITIC GROWTH ZONE WITH SUPER SATURATION WITH RESPECT
TO ICE. THUS THERE WILL BE GOOD SNOW POTENTIAL FROM THE LIMITED QPF
THAT HAS BEEN CONSISTENTLY FORECAST FOR THIS SYSTEM.
THIS EVENING...WILL ISSUE A WIND CHILL ADVISORY FOR WIND CHILLS 25
TO 30 BELOW EXTENDING FROM BOTTINEAU COUNTY SOUTHEAST THROUGH
STUTSMAN COUNTY. TOWNS INCLUDED IN THIS AREA INCLUDE
BOTTINEAU...RUGBY... HARVEY AND JAMESTOWN.
BY SUNDAY MORNING THE SNOW WILL END. SHOULD SEE CONSIDERABLE
SUNSHINE BOT COLD TEMPERATURES SUNDAY
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 245 PM CST SAT JAN 31 2015
THE PATTERN REMAINS UNSETTLED FOR THE EARLY AND LATTER PORTIONS OF
THE LONG TERM PERIOD. SHORTWAVE TROUGHS CONTINUE TO CIRCULATE AROUND
THE HUDSON BAY LOW AND INTO NORTH DAKOTA. ALTHOUGH THERE APPEARS TO
BE A BREAK WEDNESDAY INTO EARLY FRIDAY...BOTH THE GFS AND ECMWF ARE
HINTING AT ANOTHER SYSTEM FRIDAY NIGHT THROUGH SATURDAY.
SUNDAY NIGHT AND MONDAY...NOT A LOT OF CHANGE FROM PREVIOUS RUNS AND
THOUGHTS AS THIS WILL BE A BRIEF/MINOR WARM AIR ADVECTION
PRECIPITATION EVENT MONDAY. SOUTHWEST WINDS SUNDAY NIGHT WILL QUICKLY
SHIFT TO THE NORTHWEST DURING THE MORNING IN THE WEST AND AFTERNOON
IN THE CENTRAL AS COLD AIR ADVECTION AGAIN TAKES CONTROL. PER
NAM/GFS BUFKIT SOUNDINGS...HAVE TEMPERED HIGHS IN THE SOUTHWEST AS
COLD AIR ADVECTION TAKES OVER BY MID TO LATE MORNING AND BASICALLY
PUTS A CAP ON RISING TEMPERATURES. SNOWFALL POTENTIAL REMAINS LIGHT
WITH AROUND A HALF INCH ALONG AND WEST OF THE MISSOURI RIVER.
FOR TUESDAY...IT APPEARS THE STRONGER BAROCLINIC ZONE ASSOCIATED
WITH AN ARCTIC INTRUSION REMAINS IN SOUTH CENTRAL MONTANA AND
WESTERN SOUTH DAKOTA. THE GFS HAS SHIFTED THE MAIN SNOW AXIS ACROSS
THE FAR SOUTHWEST. THE NAM/ECMWF ALSO INDICATE A WEAKER SCENARIO BUT
HAVE THIS AREA FARTHER EAST AS WELL. QPF TODAY VERSUS THE LAST FEW
RUNS HAVE LOWERED QUITE A BIT. SNOWFALL ACCUMULATIONS ARE NOW MORE
LIKELY TO RANGE FROM 1 TO 1.5 INCHES ACROSS WESTERN AND SOUTH
CENTRAL NORTH DAKOTA.
WEDNESDAY THROUGH SATURDAY...MAINLY DRY CONDITIONS CAN BE EXPECTED AS
NORTHWEST FLOW CONTINUES WEDNESDAY WITH ARCTIC AIR AND SURFACE HIGH
PRESSURE DOMINATING. HIGHS WILL RANGE FROM AROUND ZERO IN THE TURTLE
MOUNTAINS TO 20 DEGREES ABOVE ZERO IN THE SOUTHWEST. WARM AIR
ADVECTION ONCE AGAIN COMMENCES THURSDAY AND FRIDAY. AN ALBERTA
CLIPPER WITH A FAIRLY TIGHT BAROCLINIC ZONE IS FORECAST TO DEVELOP
ACROSS CENTRAL AND NORTHERN NORTH DAKOTA FRIDAY THROUGH SATURDAY.
THE ECMWF IS MUCH COLDER AS THE BAROCLINIC ZONE SAGS FURTHER SOUTH.
BOTH MODELS DEPICT DECENT PRECIPITATION DEVELOPING DURING THIS
PERIOD AND SNOW WOULD BE THE LIKELY CANDIDATE IN THE NORTH. THERE IS
A POTENTIAL FOR A WINTRY MIX IN/AROUND THE WARMER SIDE OF THE
BAROCLINIC ZONE. WILL NEED TO MONITOR THIS IN THE COMING DAYS. HIGH
TEMPERATURES FRIDAY/SATURDAY WILL DEPEND ON WHERE THE BAROCLINIC
ZONE SETS UP ACROSS SOUTHWEST/NORTHERN NORTH DAKOTA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 245 PM CST SAT JAN 31 2015
HAZARDS TO AVIATION INCLUDE IFR CONDITIONS IN CLOUDS AND SNOW FROM
SURFACE TROUGH OF LOW PRESSURE FORECAST TO MOVE FROM EASTERN
MONTANA THROUGH CENTRAL NORTH DAKOTA TONIGHT. THIS WILL IMPACT
KISN-KDIK-KMOT THIS AFTERNOON...AND KDIK-KBIS TONIGHT. ARCTIC HIGH
PRESSURE WILL MOVE SOUTH FROM SASKATCHEWAN AND MANITOBA SUNDAY
BRINGING IMPROVING CONDITIONS TO VFR MOST AREA AFTER SUNRISE
SUNDAY. LOWER CLOUDS MAY LINGER LONGER AT KDIK.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL 10 AM CST SUNDAY FOR NDZ004-005-012-
013-022-023-025-036-037.
&&
$$
SHORT TERM...WAA
LONG TERM...KS
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1208 PM CST SAT JAN 31 2015
.UPDATE...
ISSUED AT 1201 PM CST SAT JAN 31 2015
DRY SLOT ACROSS SOUTH CENTRAL NORTH DAKOTA CAUSING SOME MAJOR
REVISIONS IN THE SKY GRIDS AS A BIG CLEAR HOLE HAS OPENED UP
SOUTH CENTRAL AS DRY NORTHEAST FLOW BRINGING IN LOW LEVEL DRY AIR.
SNOW SPREADING ACROSS THE NORTH AND WEST...AND WILL EVENTUALLY
REACH THE SOUTH CENTRAL THIS EVENING.
UPDATE ISSUED AT 936 AM CST SAT JAN 31 2015
LATEST BUFKIT MODEL ANALYSIS FOR THE NAM SHOW A FAIRLY DEEP
DENDRITIC GROWTH ZONE LATE THIS AFTERNOON AND TONIGHT ACROSS
WESTERN NORTH DAKOTA. WITH SUPERSATURATION WITH RESPECT TO ICE
THE LOWER ATMOSPHERE SHOULD MAXIMIZE ITS POTENTIAL FOR CREATING
SNOW. MODELS STILL HAVE MODEST QPF AMOUNTS. (THE LATEST HRRR QPF
THROUGH 04Z HAS BETWEEN 0.15-0.25). BELIEVE SNOW AMOUNTS OF 3
INCHES OVERALL WITH ISOLATED HIGHER AMOUNTS STILL LOOK GOOD.
CURRENT FORECAST LOOKS ON TRACK.
UPDATE ISSUED AT 637 AM CST SAT JAN 31 2015
NO MAJOR CHANGES TO THE GOING FORECAST. LIGHT SNOW IS DEVELOPING
ACROSS THE NORTHERN TIER COUNTIES THIS MORNING AND WILL SPREAD
SOUTH AND EAST THROUGH THE DAY. DID EXTEND THE MENTION OF FOG
THROUGH 15 UTC ACROSS THE SOUTHWEST AND FAR SOUTH CENTRAL. UPDATED
TEXT WILL BE OUT SHORTLY
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 343 AM CST SAT JAN 31 2015
THE MAIN FOCUS FOR THE SHORT TERM IS ACCUMULATING SNOW TODAY/TONIGHT.
A SHORTWAVE TROUGH CURRENTLY OVER SOUTHERN ALBERTA AND AN INVERTED
SURFACE TROUGH...CURRENTLY CENTERED ACROSS EASTERN MONTANA...WILL
SLOWLY PROPAGATE SOUTHEAST THROUGH THE MORNING HOURS. AS IT DOES
WIDESPREAD SNOW ACROSS SOUTHERN CANADA IS EXPECTED TO CONTINUE TO
DEVELOP AND ENTER NORTHWESTERN NORTH DAKOTA. A DEFORMATION ZONE IS
EXPECTED TO SET UP ACROSS WESTERN NORTH DAKOTA LATER THIS MORNING
AS A SHORTWAVE TROUGH OVER THE FOUR CORNERS INTERACTS WITH THE
ALBERTA SHORTWAVE. 00 UTC MODELS ARE IN GOOD AGREEMENT ON TIMING
AND LOCATION OF THE SNOW. BY 6AM A LIGHT SNOW BAND SHOULD BEGIN
OVERSPREADING NORTHWESTERN NORTH DAKOTA. THIS BAND IS EXPECTED TO
SLIDE SLOWLY SOUTH THROUGH THE DAY. THE ECMWF/NAM/SREF/GFS ALL
HAVE THE HEAVIEST QPF AMOUNTS ACROSS WEST CENTRAL NORTH DAKOTA
DURING THE AFTERNOON HOURS. FOR THE FORECAST WENT WITH A BLEND OF
THE OPERATIONAL MODELS WHICH ENDS UP PRODUCING WIDESPREAD 2 TO 3
INCHES OF SNOW ACROSS WESTERN AND CENTRAL NORTH DAKOTA...WITH
HEAVIEST AMOUNTS WEST OF HIGHWAY 83.
TEMPERATURES WILL CONTINUE TO GRADUALLY FALL THROUGH THE DAY WITH
CLOUDY SKIES LIMITING SOLAR INSULATION AND COLD AIR ADVECTION
CONTINUES IN FULL FORCE. TEMPERATURES WILL LIKELY FALL BELOW ZERO
ACROSS THE JAMES VALLEY TONIGHT. WIND CHILL READINGS WILL NEAR 20
BELOW BY THE EARLY MORNING HOURS.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 343 AM CST SAT JAN 31 2015
MAIN FORECAST HIGHLIGHTS ARE COLD AND UNSETTLED WEATHER THROUGH AT
LEAST MID WEEK WITH A NUMBER OF LIGHT SNOW EVENTS. THEN POSSIBLY A
RETURN TO MORE MILD CONDITIONS AT THE END OF THE EXTENDED PERIOD.
DETERMINISTIC MODELS ARE IN QUITE GOOD AGREEMENT THROUGH MOST OF THE
EXTENDED PERIOD AND USED A MODEL BLEND FOR FORECAST DETAILS.
WE BEGIN THE PERIOD SUNDAY WITH A 1040 MB SURFACE HIGH DROPPING
FROM SOUTHERN CANADA INTO CENTRAL NORTH DAKOTA BY 18 UTC SUNDAY.
LIGHT SNOWS FROM THE EXITING SHORT TERM SYSTEM SHOULD BE ALL BUT OUT
OF THE SOUTHERN CWA BY 18 UTC...BUT DID INCLUDE A SLIGHT CHANCE OF
LIGHT SNOW WITH OVER THE FAR SOUTH CENTRAL AS REMNANTS MOVE OUT OF
THE FORECAST AREA SUNDAY MORNING. OTHERWISE DRY BUT COLD SUNDAY.
WIND CHILL HIGHLIGHTS MAY BE NEEDED SUNDAY MORNING IF CURRENT TRENDS
HOLD...OVER THE TURTLE MOUNTAINS INTO THE JAMES RIVER VALLEY.
AS THE SURFACE HIGH SLIDES SOUTHEAST SUNDAY NIGHT WARM ADVECTION
RETURNS TO WESTERN NORTH DAKOTA. BY MONDAY MORNING...UPPER LEVEL
FORCING WITH A 120KT JET INDUCES A SURFACE LOW PRESSURE CENTER OVER
SOUTHEAST MONTANA THAT TRACKS SOUTHEAST ACROSS INTO CENTRAL SOUTH
DAKOTA. THE GFS IS THE WEAKEST AND FARTHEST SOUTH WITH THE SURFACE
LOW AND BRINGS VERY LIGHT SNOW AMOUNTS INTO THE FAR SOUTHWEST. ALL
OTHER DETERMINISTIC MODELS TRACK THE SURFACE LOW IN A FAVORED
POSITION TO BRING LIGHT SNOWS TO WESTERN AND SOUTH CENTRAL NORTH
DAKOTA. AMOUNTS HERE ARE DEFINITELY SUB-ADVISORY CRITERIA AND AS A
FIRST GUESS HAVE GONE WITH HALF INCH TO ONE INCH AMOUNTS ALONG AND
SOUTH OF LAKE SAKAKAWEA AND THE MISSOURI RIVER...WITH LITTLE OR NO
ACCUMULATIONS NORTH AND EAST OF HERE. TAKING THE GFS OUT OF THE
BLEND WOULD YIELD HIGHER AMOUNTS...MAYBE 1-2 INCHES IN THIS SAME
GENERAL AREA...SO WILL HAVE TO MONITOR...BUT STILL SUB-ADVISORY
SNOWS.
ANOTHER IMPULSE QUICKLY RACES INTO THE AREA ALREADY BY LATE MONDAY
NIGHT. THIS TIME THERE IS A TIGHTER BAROCLINIC ZONE THAT IMPULSES
WILL INTERACT WITH OVER THE SAME GENERAL AREA OF WESTERN INTO SOUTH
CENTRAL NORTH DAKOTA. THERE ARE SOME MODEL DIFFERENCES IN THE
PLACEMENT OF THE SURFACE AND UPPER LEVEL FEATURES BUT MODELS ARE
CURRENTLY IN GOOD AGREEMENT IN BRINGING ANOTHER SWATH OF LIGHT SNOWS
OVER WESTERN AND SOUTH CENTRAL NORTH DAKOTA...WITH THE TURTLE
MOUNTAINS AREA ONCE AGAIN SEEING THE THE SMALLEST CHANCES OF
ACCUMULATING SNOWS. IN GENERAL...WE ARE TALKING SUB-ADVISORY
CRITERIA SNOWS OF 1 TO 3 INCHES LATE MONDAY NIGHT THROUGH TUESDAY.
THE GFS IS A LITTLE MORE IMPRESSIVE WITH THE SURFACE LOW AND HINTS
AT SOME INDIRECT JET CIRCULATION BETWEEN THE TWO STRONG JETLETS OVER
THE NORTHERN PLAINS. THUS WILL NEED TO KEEP AN EYE ON THIS SYSTEM AS
WELL.
ONE LAST IMPULSE KEEPS A LINGERING CHANCE OF LIGHT SNOW OVER THE
SOUTHWEST THROUGH TUESDAY EVENING...THEN ARCTIC HIGH PRESSURE DROPS
INTO THE AREA AND PUTS AN END TO THE SNOW CHANCES BY LATE TUESDAY
NIGHT. HOWEVER...WIND CHILLS WILL LIKELY AGAIN BE AN ISSUE OVER
MAINLY THE NORTHERN THIRD OF THE FORECAST AREA.
WE THEN WARM UP QUICKLY THURSDAY AS THE ARCTIC HIGH DIVES QUICKLY
SOUTH AND EAST. WE TRANSITION TO A MORE QUASI-ZONAL FLOW WITH
SHORTWAVES TRAVERSING THE AREA FRIDAY AND SATURDAY. WITH THE WARMER
TEMPERATURES WE MAY NEED TO WORRY MORE ABOUT POSSIBLE MIXED
PRECIPITATION BUT TEMPERATURES WILL BE BACK ABOVE NORMAL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1201 PM CST SAT JAN 31 2015
MAIN HAZARD TO AVIATION FOR THE 18Z FORECAST INCLUDES IFR
CONDITIONS IN CLOUDS AND SNOW. SURFACE TROUGH OF LOW PRESSURE
ACROSS EASTERN MONTANA WILL MOVE SOUTHEAST TODAY AND TONIGHT.
EXPECT DETERIORATING CONDITIONS FROM WEST TO EAST A A LARGE SNOW
REGION MOVES FROM WESTERN INTO CENTRAL NORTH DAKOTA THIS
AFTERNOON AND TONIGHT. ARCTIC HIGH PRESSURE WILL NOSE IN FROM
SASKATCHEWAN TONIGHT AND SUNDAY BRINGING IMPROVING CONDITIONS AFTER
12Z NORTH AND EAST.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...WAA
SHORT TERM...AJ
LONG TERM...TWH
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
351 PM CST SAT JAN 31 2015
.SHORT TERM...
(Tonight and Sunday )
Light rain was moving north of I-20, and east of an Abilene...
Brady...Mason line at 3 PM. An upper low was west of El Paso, moving
slowly southeast.
Rain was pushing east and ending of West Central, faster than the
models indicated. Indeed at the current pace, nearly all the present
rain at 3 PM will be east or north of West Central Texas by 6 PM.
Kept a chance of showers going overnight, however, with the El Paso
low sending weak disturbances eastward. Additional rainfall amounts
will be light...ranging from a trace to a few hundredths inch. The
NAM and EC models bring isolated to scattered light showers over
West Central Texas tonight. The GFS model`s convective algorithm is
dry. The short range HRRR model brings in scattered showers, mainly
over Crockett county, the Concho Valley and areas southward. Timing
was between 9 PM and 4 AM. This may actually be the best model as it
seems to latched on an area of lift in the water vapor loop south of
El Paso.
A cold front will move through West Central Texas Sunday bringing
gusty north winds by noon. This clear low level moisture and clouds.
Sunshine in the afternoon should allow afternoon highs to be a 2-4
degrees warmer than today`s, despite cold air advection.
.LONG TERM...
(Sunday night through next Saturday)
Warmer weather will make a return to West Central Texas for the
first half of the week. An area of high pressure centered over the
region on Monday, will slide off to our east by mid-week. A thermal
ridge at 850 mb will expand east over the area, allowing high
temperatures to climb from the mid 50s on Monday, to the mid 60s by
Wednesday. A weak cold front approaching the area from the north
Wednesday night, will wash out near Interstate 10 during the day
Thursday, bringing cooler/drier air to the region. However, this
will be short-lived, as a lee trough develops to our west on Friday.
With a return flow developing, warmer temperatures and increasing
moisture are expected.
Precipitation chances may also increase for the southern half of the
forecast area. An upper-level disturbance currently located over
Baja California, is expected to pass by to our southeast Tuesday
night/Wednesday morning. This system may bring a chance of rain to
the region, mainly south of a line from San Angelo to Brownwood.
This afternoon`s numerical models have once again shifted the track
of the disturbance farther south and east, reducing forecast
confidence. However, the models have been flip-flopping on the track
for the last few model runs, and considering the system is still
largely in a data-void region, this will likely continue through the
next 48 hours. By then, the system will enter an improving
observational/upper-air network, which may result in improved model
continuity. Given the concerns mentioned above, only minimal changes
were made to the rainfall forecast for the middle of the week.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 49 51 24 51 36 / 40 10 5 5 5
San Angelo 51 60 27 54 36 / 30 10 5 5 5
Junction 52 64 30 55 34 / 60 20 5 5 5
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
04/Doll
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1209 PM CST SAT JAN 31 2015
.AVIATION...
COMPLICATED TAF PACKAGE WITH MAIN CONCERNS CENTERING AROUND MVFR
TO IFR CEILINGS...TIMING RAIN ASSOCIATED WITH SEVERAL DISTURBANCES
CROSSING THE AREA...AND VISIBILITY RESTRICTIONS FROM
PRECIPITATION.
MAIN PRECIP SHIELD ASSOCIATED WITH A 500 MB
SHORTWAVE TROUGH STILL REMAINS WEST OF THE TERMINALS THIS
MORNING...BUT IS SLOWLY TRANSLATING EAST TOWARDS THE INTERSTATE 35
CORRIDOR. OTHER SUBTLE WAVES IN THE MESSY SOUTHWEST FLOW ALOFT
HAVE ALSO CONTRIBUTED TO SMALLER POCKETS OF -RA. GIVEN TRAJECTORY
OF MAIN WAVE... THINK RAIN COLLEGE STATION/HUNTSVILLE/POTENTIALLY
CONROE WILL SEE -RA AROUND 00Z AS THE MAIN 500 MB WAVE TRANSLATES
NORTH OF THE REGION. VCSH TO EVEN -RA WILL BE POSSIBLE LATER THIS
EVENING /03-06Z FOR THE HOUSTON TERMINALS/ AS OTHER SUBTLE WAVES
CROSS THE AREA. MVFR VISIBILITY RESTRICTIONS WILL BE POSSIBLE IN
HEAVIER RAIN...WITH THE BULK OF THE ACTIVITY LOOKING TO CLEAR THE
AREA BETWEEN 10-12Z SUNDAY. ADDITIONALLY... CONTINUED LOW LEVEL
MOISTURE RETURN WILL REPLACE PERIODS OF VFR EARLY THIS AFTERNOON
WITH MVFR BY THIS EVENING WITH 10 TO 15 KNOT EASTERLY TO
SOUTHEASTERLY WINDS THIS AFTERNOON TO BECOMING SOUTHEASTERLY AND
LESS THAN 10 KNOTS TONIGHT AS THE REGION LOSES THE INFLUENCE OF
THE SURFACE RIDGE.
THE NEXT CONCERN THEN BECOMES THE TIMING OF A STRONG COLD FRONT
ENTERING THE STATE ON SUNDAY AND SHOWERS /WITH POTENTIALLY AN
ISOLATED THUNDERSTORM OR TWO/ DEVELOPING ALONG AND AHEAD OF THE
FRONT. WINDS WILL VEER TO THE SOUTHWEST AS A PREFRONTAL TROUGH
CROSSES THE TERMINALS... REACHING THE NORTHERN TERMINALS BY MID-
MORNING SUNDAY. TTU-WRF RUNS HAVE BECOME INCREASINGLY ANEMIC
REGARDING PRECIPITATION ALONG THE FRONT AND CONFIDENCE IS LOW WITH
AREAL COVERAGE OF RAIN TOMORROW WITH MORE TIME TO REFINE. COLD
FRONT LOOKS TO CLEAR THE TERMINALS AFTER THE END OF THE TAF
PERIOD...BUT ANTICIPATE GUSTY WINDS IN ITS WAKE LATE SUNDAY
AFTERNOON/EVENING.
ADDITIONALLY...NAM12 AND RAP PROGS ARE SHOWING 975 MB WINDS OUT OF
THE SOUTHWEST AROUND 30-35 KNOTS GENERALLY BETWEEN 09-12Z SUNDAY
MORNING. THIS COULD POSE BORDERLINE LLWS CONCERNS DEPENDING ON IF
THESE STRONGER WINDS MATERIALIZE /OR SURFACE WINDS DECREASE MORE
THAN ANTICIPATED TONIGHT/. GIVEN LOW CONFIDENCE...NO MENTION WAS
INCLUDED IN THE TAFS BUT WILL BE SOMETHING TO CONTINUE TO MONITOR.
HUFFMAN
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 62 58 65 37 49 / 40 60 60 10 0
HOUSTON (IAH) 62 58 69 41 51 / 20 50 70 20 0
GALVESTON (GLS) 62 57 64 45 50 / 20 40 50 30 0
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$