Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 01/12/14
AREA FORECAST DISCUSSION
NWS ALBANY NY
700 PM EST SAT JAN 11 2014
.SYNOPSIS...
A STRONG COLD FRONT WILL MOVE ACROSS THE REGION THIS EVENING. RAIN
WILL END FROM WEST TO EAST WITH COOLER TEMPERATURES RETURNING
OVERNIGHT INTO SUNDAY. WEST TO NORTHWEST WINDS WILL INCREASE
DURING SUNDAY WITH OCCASIONAL STRONGER GUSTS. A RIDGE OF HIGH
PRESSURE SLIDES ACROSS SUNDAY NIGHT WITH TRANQUIL WEATHER
CONDITIONS. A SOUTHERLY FLOW OF AIR ARRIVES MONDAY WITH MILD
TEMPERATURES ALONG WITH AN INCREASE IN CLOUD COVER.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
FLOOD WATCH REMAINS IN EFFECT...
AS OF 659 PM EST...THE MAIN LINE OF SHOWERS...SOME WITH HEAVY
RAINFALL...WAS MOVING TO THE EAST OF THE REGION...HEAVIEST SOUTH AND
EAST OF THE CAPITAL REGION. THE COLD FRONT WAS STILL ACROSS CENTRAL
NEW YORK STATE AND WILL WORK ACROSS OUR EASTERN NEW YORK DURING THE
EVENING HOURS...AND NOT COMPLETELY ACROSS WESTERN NEW ENGLAND UNTIL
AROUND MIDNIGHT. THERE WAS A FINE LINE OF SHOWERS ASSOCIATED WITH
IT.
THE LATEST RUC AND NAM ANALYSIS INDICATED THE LOWEST SHOWALTER
INDICES WERE +2 IN OUR SE AREAS. THERE HAVE BEEN NO CLOUD TO GROUND
LIGHTNING STRIKES IN OUR REGION FOR OVER AN HOUR...THE LAST ONES OFF
THE SOUTHERN NJ COAST. WILL REMOVE ANY MENTION OF THUNDER.
LOOK FOR ABOUT THREE MORE HOURS OF RAINFALL...MODERATE AT
TIMES...TAPERING TO SCATTERED SHOWERS THEREAFTER.
FOG FROM THIS POINT ON LOOKS VERY PATCHY AND ON THE MOVE. DID NOT
INCLUDE IT IN THE GRIDS ALTHOUGH IT COULD IMPACT PLACES BRIEFLY INTO
THE EVENING HOURS.
TEMPERATURES REMAINED VERY MILD...WITH MANY PLACES STILL WELL INTO
THE 50S...EVEN 40S ACROSS THE ADIRONDACKS...BUT AN AMAZING 60
DEGREES AT BENNINGTON.
AFTER THE COLD FRONT MOVES...DEWPOINTS WILL DROP INTO THE
30S...TEMPERATURES SLOWLY INTO THE 40S. THE AIR WILL DRY BUT THERE
STILL COULD BE A FEW MUCH LIGHTER SHOWERS AROUND THROUGHOUT THE
EVENING...NOT AMOUNTING TO MUCH.
OVERNIGHT...WE SHIFT GEARS TOWARD LAKE EFFECT ACTIVITY INCREASING
DOWNWIND OF LAKE ONTARIO. H850 TEMPS DROP BACK TOWARD TOWARD -6C/-7C
OVERNIGHT OVER THE RELATIVELY OPEN WATERS WHERE AVERAGE WATER TEMPS
WERE AROUND 3C PER THE GLERL OBSERVATIONS. THIS WOULD SUGGEST THE
DELTA T/S WOULD REMAIN LESS THAN FAVORABLE EVEN WITH UPSTREAM LAKE
CONNECTION FROM EITHER HURON OR GEORGIAN BAY. SO WE WILL HOLD POPS
INTO THE CHC-SCT THRESHOLDS WITH A RAIN/SNOW SHOWER MIXTURE
TRANSITIONING TO ALL SNOW SHOWERS OVERNIGHT.
THE UPPER TROUGH TOO WILL BE APPROACHING THE REGION OVERNIGHT
WHICH SHOULD KEEP CLOUDS IN PLACE AND MAINLY TERRAIN BASED CHC TO
SCT RA/SN SHOWERS. OVERNIGHT LOWS PER THE MOS GUIDANCE LOOK RATHER
CLOSE AND PER THE UPSTREAM OVERNIGHT LOW OBSERVATIONS...WE WILL
SHADE ON THE SLIGHTLY WARMER SIDE OF THE GUIDANCE. LOOK FOR LOWS IN
THE 30S...ABOVE FREEZING...EXCEPT AT OR BELOW FREEZING ACROSS THE
ADIRONDACK PARK.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
SUNDAY...
UPPER TROUGH AXIS SLIDES ACROSS THE REGION IN THE MORNING WHERE
CLOUDS AND SOME SHOWER ACTIVITY /MAINLY ACROSS THE TERRAIN AND
NEAR LAKE ONTARIO/ WILL BE MOST PREVALENT. AS THIS UPPER TROUGH
SLIDES EAST...INCREASING SUBSIDENCE AND GRADUAL IMPROVEMENTS TO
THE SKY FORECAST ARE EXPECTED. HOWEVER...WITH THE INCREASE IN SOME
SUNSHINE...THE MIXING LAYER HEIGHT TAPS INTO 30-40KT WINDS.
FURTHERMORE...POTENTIAL FOR SOME FUNNELING DOWN THE MOHAWK MAY
INCREASE THOSE MAGNITUDES. PER COLLABORATION...WE WILL HOLD OFF ON
WIND ADVISORIES AT THIS TIME AS CONFIDENCE IS JUST BELOW
THRESHOLDS BUT WILL MENTION IN THE HWO. PER THOSE MIXING LAYER
HEIGHTS...WE WILL FAVOR HIGH TEMPERATURES INTO THE 40S FOR THE
VALLEY LOCATIONS AND 30S FOR THE HIGHER TERRAIN.
SUNDAY NIGHT...
RIDGE AXIS SLIDES ACROSS FOR TRANQUIL CONDITIONS AND ANY LAKE
RESPONSE QUICKLY DISSIPATING. AS WARMER AIR ADVECTS IN ALOFT...AND
THE LOSS OF SNOW PACK...WE WILL HOLD OVERNIGHT LOWS MAINLY INTO THE
MIDDLE 20S UNDER A PTCLOUDY-MOCLR SKY.
MONDAY INTO MONDAY NIGHT...
UPPER TROUGH AXIS MOVING INLAND ACROSS THE PACIFIC NORTHWEST WILL
ADVANCE EAST ACROSS THE NORTHERN PLAINS ON MONDAY. THE DEPARTURE
OF THE RIDGE AXIS AND THE APPROACH OF THIS TROUGH AXIS AND
DEVELOPING COLD FRONT WILL INCREASE THE SOUTHERLY WIND FOR A
RELATIVELY MILD DAY UNDER PARTIAL SUNSHINE. NCEP MODEL SUITE IS A
LITTLE SLOWER SO WE WILL CONTINUE TO WITHHOLD THE MENTION OF
PRECIP UNTIL MONDAY NIGHT.
MOISTURE TRANSPORT IS EXPECTED/PROGGED TO INCREASE FROM THE SOUTH
MONDAY EVENING WITH PRECIPITATION DEVELOPING ALONG THE FRONT.
THERMAL PROFILES OFFER A MIXTURE OF RAIN/SNOW SHOWERS WITH MAINLY
LIQUID TO START THEN A TRANSITION TO A WINTRY MIX OF RA/SN
OVERNIGHT. MOS GUIDANCE SUGGESTS OVERNIGHT LOWS DROPPING TOWARD
THE FREEZING MARK BY SUNRISE BUT WITH A LITTLE SLOWER ARRIVAL
ALONG WITH CLOUD COVER AND MILDER THERMAL PROFILES...WE WILL KEEP
OVERNIGHT LOWS A BIT MILDER.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
THE EXTENDED FORECAST PERIOD WILL INVOLVE A "WAVY" PATTERN AS SERIES
OF DISTURBANCES LOOK TO ULTIMATELY CARVE OUT A TROUGH IN THE
NORTHEASTERN CONUS. THE NORTHERN JETSTREAM WILL BE THE DOMINATING
ONE. WHILE IT WILL BE SOMEWHAT UNSETTLED...MOISTURE WILL GENERALLY
BE LIMITED WITH EACH OF THE SYSTEMS AS THEY MOVE FAIRLY QUICKLY.
TEMPERATURES WILL START OFF ABOVE NORMAL BUT TREND TO A LITTLE BELOW
NORMAL BY NEXT WEEKEND.
ON TUESDAY...INITIAL VORTICITY FROM A DIGGING MID LATITUDE TROUGH
OVER THE OHIO VALLEY...COULD SPAWN A SURFACE LOW OVER THE SOUTHEAST
OR LOW MID ATLANTIC REGION. INTERESTING...THE GFS WAS THE FIRST TO
REFLECT THIS IDEA...BUT HAS NOW BACKED OFF...KEEPING ANY WEAK
SURFACE WAVE WELL TO THE EAST. HOWEVER SINCE THE CANADIAN/ECMWF AND
WPC SOLUTIONS INDICATED IT...WE WENT WITH THE MAJORITY OF THIS
SOLUTION. WHILE ALL MODELS INDICATED THE MAJORITY OF PRECIPITATION
MISSES OUR REGION...IT WILL BE A CLOSE CALL...ESPECIALLY OVER OUR
SOUTHEASTERN ZONES SO WILL CONTINUE WITH 30-50 POPS ON THAT DAY
(HIGHEST SOUTHEAST).
HIGH TEMPERATURES ON TUESDAY LOOK TO BE IN THE LOWER 30S ACROSS THE
ADIRONDACKS...35 TO 40 REMAINING AREAS TO THE NORTH OF THE CAPITAL
REGION AND BERKSHIRES...LOWER 40S CAPITAL REGION...MID TO UPPER 40S
MID HUDSON VALLEY AND LITCHFIELD COUNTY. THIS WILL MEAN MUCH OF THE
PRECIPITATION THAT WOULD FALL (ASSUMING IT WILL BE LIGHT) SHOULD BE
RAIN IN THE VALLEYS...RAIN AND A WET SNOW MIX ACROSS THE HIGHER
TERRAIN.
TUESDAY NIGHT...LOOKS LIKE A BRIEF AREA OF SUBSIDENCE WILL OCCUR AS
THE FIRST SURFACE SYSTEM DEPARTS AND ANOTHER APPROACHES FROM THE
WEST. WILL KEEP SLIGHT POPS IN. OVERNIGHT LOWS WILL BE IN THE 20S.
WEDNESDAY AND WEDNESDAY NIGHT....WHILE THE FIRST SURFACE LOW
ASSOCIATED WITH THE UPPER LEVEL TROUGH WILL BE TO OUR EAST...ALL
MODELS (EXCEPT THE CANADIAN) DEVELOP ANOTHER LOW ON WEDNESDAY NEAR
OUR REGION...AS THE THE MAIN MID LEVEL TROUGH SLOWLY WORKS INTO THE
REGION...WITH THE ECMWF ACTUALLY CUTTING THIS FEATURE OFF. WE
INCREASE POPS UP TO 30 PERCENT AND 40 PERCENT BY WEDNESDAY NIGHT.
AGAIN PRECIPITATION LOOKS LIGHT. HIGH TEMPERATURES WILL BE A LITTLE
COOLER ON WEDNESDAY...AROUND 30 ACROSS THE ADIRONDACK PARK...MID OR
UPPER 30S ACROSS MOST OF THE REMAINDER OF THE REGION...EXCEPT AROUND
40 IN THE MID HUDSON VALLEY AND LOWER LITCHFIELD. AGAIN...THESE
TEMPERATURES WILL LIKELY MEAN ANY LIGHT PRECIPITATION WOULD FALL
MAINLY AS RAIN IN THE VALLEYS...AND WET SNOW...POSSIBLY MIXED WITH A
LITTLE RAIN OVER THE HIGHER TERRAIN...EXCEPT ALL SNOW ACROSS THE
ADIRONDACKS. WEDNESDAY NIGHT WITH COLDER TEMPERATURES EXPECTED BACK
DOWN IN THE 20S (TEENS ADIRONDACKS) ANY PRECIPITATION WOULD FALL AS
SNOW OR SNOW SHOWERS.
THURSDAY AND THURSDAY NIGHT...THE MID LEVEL TROUGH SHOULD BE TO OUR
EAST...AND AGAIN SOME SUBSIDENCE AND POSSIBLE RIDGING LOOKS TO DRY
US OUT WITH PARTIAL SUNSHINE. ONLY PLACES TO HAVE POPS ON THURSDAY
WILL BE THE ELEVATED TERRAIN DUE TO POSSIBLE RESIDUAL LAKE ENHANCED
UPSLOPE SHOWERS OF SNOW. TEMPERATURES LOOK TO BE SEASONABLE...WITH
HIGHS RANGING FROM THE UPPER 20S ACROSS OUR NORTHWESTER
AREAS...LOWER 30S CAPITAL REGION...MID OR UPPER 30S MID HUDSON
VALLEY AND LOWER LITCHFIELD. OVERNIGHT LOWS WILL BE IN THE 20S.
THEN ON FRIDAY...AN EVEN STRONGER DIGGING TROUGH APPROACHES WITH
FROM THE GREAT LAKES...INCREASES CHANCES OF PRECIPITATION ONCE MORE.
A SOUTHERLY BREEZE AHEAD OF AN APPROACHING COLD FRONT WILL BUMP
TEMPERATURES BACK UP TO A LITTLE ABOVE NORMAL...RANGING FROM AROUND
30 NORTHWEST TO AROUND 40 SOUTHEAST. PRECIPITATION WILL BE IN THE
FORM OF VALLEY RAIN SHOWERS...MOUNTAIN SNOW OR A RAIN SNOW MIX.
ARCTIC AIR WILL FOLLOW BEHIND THIS FEATURE...LOWERING TEMPERATURES
TO MAINLY THE TEENS FRIDAY NIGHT AND HOLDING THEM MAINLY IN THE 20S
ON SATURDAY. ASIDE FROM SOME POSSIBLE LAKE ENHANCED SNOW SHOWERS
ACROSS THE ADIRONDACKS/MOHAWK VALLEY AND SOUTHERN GREENS....OTHER
AREAS LOOK DRY BUT BRISK.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
MAINLY MVFR/IFR CONDITIONS WILL CONTINUE THROUGHOUT THE EVENING PEAK
AS A COLD FRONT APPROACHES FROM THE WEST...AND A MOIST SOUTHERLY
FLOW WILL CONTINUES AHEAD OF THE FRONT. OCCASIONALLY...CIGS AND OR
VSBYS COULD SLIP TO LIFR AS THEY HAVE AT KGFL AND KALB. WE DID NOT
INCLUDE ANY IFR AT KPOU AS THEY SEEM TO BE BENEFITING FROM A
DOWNSLOPING SW FLOW...WHICH WILL BECOME WESTERLY. WE DID HOWEVER
OCCASIONALLY DROP CIGS TO UNDER 2000 FEET...REQUIRING EXTRA FUEL FOR
A FEW HOURS THIS EVENING.
THE WINDS AROUND 2000 FEET LOOK TO HAVE WEAKEN ENOUGH TO REMOVE ANY
LLWS FROM OUR TAFS. WE HAVE NOT SEEN ANY PIREPS REPORTING ANY LLWS
(SOME HIGHER LEVELS OF TURBULENCE HAVE BEEN REPORTED). THE 00Z ALY
RAOB SOUNDING INDICATED WINDS AROUND 35 KTS. ALSO...MORE MIXING WAS
TAKING PLACE AT THE TAF SITES.
ONCE THE COLD FRONT PASSES THROUGH THE REGION AFTER 03Z SUNDAY...A
LEFTOVER VCSH OR -SHRA IS POSSIBLE BEHIND THE FRONT THROUGH MUCH OF
THE NIGHT. THE WIND WILL SHIFT TO WESTERN TO WEST NORTHWESTERLY 5-10
KTS BEHIND THE FRONT AND IN PARTICULAR...GUSTS STILL ABOVE 20 KTS
POSSIBLE ESPECIALLY AT KALB/KPSF. OTHERWISE...CONDITIONS WILL
IMPROVE IMPROVE TO VFR CONDITIONS AFTER 06Z SUNDAY...SLOWEST TO DO
SO AT KGLF.
SUNDAY WILL LIKELY VFR AT ALL THE SITES...BUT IT WILL BE QUITE
BREEZY WITH THAT WEST TO NORTHWEST WIND AVERAGING 10-15
KTS...GUSTING TO 25KTS OR A LITTLE HIGHER...MAINLY AT KALB AND
KPSF.
OUTLOOK...
SUNDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
MONDAY: LOW OPERATIONAL IMPACT.BREEZY NO SIG WX.
MONDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
TUESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA. TUESDAY NIGHT:
LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA...SHSN.
WEDNESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...SHSN.
WEDNESDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN.
THURSDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA...SHSN.
&&
.HYDROLOGY...
THE FLOOD WATCH REMAINS IN EFFECT THROUGH SUNDAY...WITH THE
PRIMARY THREAT ICE JAM FLOODING.
RIVERS ARE RESPONDING TO THE RAINFALL ACROSS THE REGION WITH THE
CATSKILLS BEING THE CENTER OF THE HIGHER RAINFALL TOTALS PER
MESONET OBSERVATIONS. IN ADDITION...TEMPERATURES ARE QUITE MILD
WITH MAINLY 50S AND NOW SOME LOWER 60S FOR THE MID HUDSON
VALLEY...NW CT...BERKSHIRES...TACONICS AND WESTERN GREENS
/DOWNSLOPING/. LATEST NERFC QPF SUGGESTS THE BEST QPF WILL OCCUR
BEFORE 00Z WITH AROUND ONE INCH MAINLY INTO THE TERRAIN SOUTH AND
EAST OF ALBANY. FURTHERMORE...ICE JAMS REMAIN THE GREATEST THREAT
AS WARMER TEMPERATURES AND RAINFALL WILL ALLOW FOR ICE TO MOVE.
THE NEXT SEVERAL DAYS WE WILL EXPERIENCE A DIURNAL RANGE OF ABOVE
FREEZING TEMPERATURES DURING THE DAYLIGHT HOURS AND AT OR BELOW
FREEZING AT NIGHT. THIS WILL LIKELY RESULT IN ICE MOVEMENT/MELTING
WHICH COULD ALSO RESULT IN ISOLATED AREAS OF ICE JAMS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...FLOOD WATCH THROUGH SUNDAY AFTERNOON FOR CTZ001-013.
NY...FLOOD WATCH THROUGH SUNDAY AFTERNOON FOR NYZ032-033-038>043-
047>054-058>061-063>066-082>084.
MA...FLOOD WATCH THROUGH SUNDAY AFTERNOON FOR MAZ001-025.
VT...FLOOD WATCH THROUGH SUNDAY AFTERNOON FOR VTZ013>015.
&&
$$
SYNOPSIS...HWJIV/BGM
NEAR TERM...HWJIV/BGM
SHORT TERM...BGM
LONG TERM...HWJIV
AVIATION...HWJIV
HYDROLOGY...BGM
AREA FORECAST DISCUSSION
NWS ALBANY NY
447 PM EST FRI JAN 10 2014
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO SHIFT EASTWARD AND OFFSHORE
OVERNIGHT...AS A STRENGTHENING STORM SYSTEM MOVES ACROSS THE
WESTERN GREAT LAKES AND SOUTHEAST CANADA LATE TONIGHT INTO
SATURDAY. MILDER AIR WILL BE USHERED INTO THE REGION AS THE SYSTEM
AND ITS ASSOCIATED FRONTAL SYSTEM APPROACHES. SOME FREEZING RAIN
IS POSSIBLE LATE TONIGHT INTO EARLY SATURDAY MORNING...THEN RAIN
IS EXPECTED INTO SATURDAY NIGHT...WITH SOME LOCALLY HEAVY RAIN
POSSIBLE DURING THE AFTERNOON AND EVENING HOURS. IMPROVING
CONDITIONS...ALONG WITH ABOVE NORMAL TEMPERATURES ARE EXPECTED FOR
SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
...FREEZING RAIN ADVISORIES ISSUED FOR THE OVERNIGHT HOURS...
...FLOOD WATCH REMAIN IN EFFECT FOR SAT AFTN THROUGH SUN AFTN...
AS OF 445 PM EST...SOME BREAKS IN THE CLOUDS CONTINUE ACROSS
PORTIONS OF THE GREATER CAPITAL REGION...WITH MOSTLY CLOUDY SKIES
ELSEWHERE. TEMPS HAVE RISEN INTO THE LOWER 30S FOR MOST AREAS
SOUTH AND EAST OF THE CAPITAL REGION...WITH MAINLY UPPER 20S TO
LOWER 30S TO THE NORTH AND WEST. THE AFOREMENTIONED PARTIAL
CLEARING APPEARS TO HAVE BEEN LARGELY DUE TO SOME SUBSIDENCE IN
THE WAKE OF THE SHORTWAVE...WHICH PASSED EAST ACROSS THE REGION
EARLIER TODAY...AND ALSO DUE TO SOME DOWNSLOPING OFF THE CATSKILLS
DUE TO A STRENGTHENING SOUTHWEST FLOW AROUND 4000-6000 FT AGL.
LOOKING TO OUR SOUTH...PRECIPITATION CONTINUES TO DEVELOP ACROSS
PORTIONS OF THE MID ATLANTIC STATES...WHERE LOW/MID LEVEL
ISENTROPIC LIFT AND THETA-E ADVECTION INCREASES. SHORT-TERM
MODELS...SUCH AS THE RAP13 AND HRRR SUGGEST THAT THIS AREA OF
FORCING TRANSLATES NORTH NORTHEAST INTO SOUTHERN PORTIONS OF THE
REGION BETWEEN 10 PM AND MIDNIGHT...AND GENERALLY BETWEEN MIDNIGHT
AND 4 AM FURTHER N AND W. THERMAL PROFILES SUGGEST HYDROMETEORS
SHOULD BE PRIMARILY LIQUID...ALTHOUGH SOME SLEET COULD BE MIXED IN
ACROSS NORTHERN AREAS INITIALLY. SFC TEMPS...WHICH ARE CURRENTLY
JUST BARELY ABOVE FREEZING...ARE EXPECTED TO FALL AT LEAST A FEW
DEGREES THIS EVENING...BEFORE LEVELING OFF...AND EVENTUALLY RISING
AFTER MIDNIGHT. HOWEVER...IT APPEARS THAT SOME LIGHT PRECIPITATION
WILL DEVELOP BEFORE SFC TEMPS RISE ABOVE FREEZING. IN
ADDITION...EVEN IF SFC TEMPS ARE AROUND OR A BIT ABOVE
FREEZING...THE GROUND REMAINS VERY COLD FROM THE RECENT COLD
SPELL...SO UNTREATED SURFACES MAY ACCRETE A LIGHT GLAZE OF
ICE...EVEN WITH TEMPS SLIGHTLY ABOVE FREEZING. THEREFORE...A
FREEZING RAIN ADVISORY HAS BEEN ISSUED AREAWIDE...ALTHOUGH THE
ENDING TIMES OF THE ADVISORY ARE EARLIER ACROSS SOUTHERN
AREAS...AND LATER...MID MORNING...FOR NORTHERN AREAS...WHERE
SUBFREEZING SFC TEMPS MAY LINGER IN SHELTERED VALLEY AREAS. TOTAL
ICE ACCRETION IS NOT EXPECTED TO BE MUCH...GENERALLY UNDER ONE
TENTH OF AN INCH...BUT MAY STILL HAVE HIGH IMPACTS ON TRAVEL DUE
TO THE FROZEN GROUND.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY NIGHT/...
SATURDAY...AS MENTIONED...SOME NORTHERN AREAS...PARTICULARLY
ACROSS PORTIONS OF THE LAKE GEORGE REGION...AND SOUTHWEST
ADIRONDACKS...AND POSSIBLY SOUTHEAST VT MAY REMAIN NEAR THE
FREEZING MARK THROUGH 9 AM EST SAT AM...WHERE POCKETS OF FREEZING
RAIN MAY LINGER. OTHERWISE...EXPECT PERIODS OF RAIN OR DRIZZLE
THROUGH MUCH OF THE DAY. AREAS OF FOG...SOME LOCALLY QUITE
DENSE...WILL ALSO LIKELY OCCUR AS THE INCREASINGLY MILD AND MOIST
AIR DRIFTS ACROSS THE VERY COLD GROUND. IT ALSO MAY BECOME QUITE
BREEZY/WINDY ACROSS HIGHER ELEVATIONS OF THE SOUTHERN GREEN
MTNS/BERKSHIRES AND TACONICS...WHERE SOUTH TO SOUTHEAST WINDS MAY
GUST UP TO 35-45 MPH AT TIMES. IN VALLEY AREAS...NOT EXPECTING AS
MUCH WIND DUE TO A RATHER STRONG LOW LEVEL INVERSION...BUT SHOULD
THE LOW LEVEL INVERSION BE WEAKER THAN CURRENTLY FORECAST...SOME
STRONGER WINDS COULD MIX WITHIN NORTH/SOUTH ORIENTED VALLEYS. THEN...AS
THE COLD FRONT APPROACHES FROM THE WEST LATER IN THE DAY...A BAND
OF MODERATE TO LOCALLY HEAVY RAINFALL IS EXPECTED TO DEVELOP AND
MOVE FROM W TO E. THIS BAND OF RAIN COULD EVOLVE INTO A NARROW
COLD FRONTAL RAINBAND...AND PRODUCE LOCALLY VERY HEAVY
RAINFALL...AND STRONG WIND GUSTS...AND RADAR TRENDS WILL HAVE TO
BE MONITORED.
SAT NT...THE AFOREMENTIONED FRONTAL RAINBAND SHOULD CONTINUE
MOVING EAST ACROSS THE REGION IN THE EVENING. BEHIND IT...A BRIEF
PERIOD OF LINGERING SHOWERS OR RAIN IS POSSIBLE...BEFORE THE RAIN
ENDS FROM W TO E IN MOST AREAS BY MIDNIGHT. HOWEVER...SOME SHOWERS
OF RAIN...AND EVENTUALLY SNOW SHOULD DEVELOP ACROSS PORTIONS OF
THE SOUTHERN ADIRONDACKS LATER AT NIGHT WITH MINOR ACCUMS. WEST
WINDS WILL ALSO INCREASE LATER AT NIGHT...ESP WITHIN THE MOHAWK
RIVER VALLEY/CAPITAL REGION/BERKSHIRES.
SUNDAY...A BRISK WEST WIND SHOULD CONTINUE THROUGH EARLY
AFTERNOON...WITH SOME GUSTS OF 30-40 MPH POSSIBLE...ESP DOWN THE
MOHAWK VALLEY AND INTO THE CAPITAL REGION AND BERKSHIRES.
HOWEVER...DESPITE GUSTY WINDS...TEMPS WILL ACTUALLY BE ABOVE
NORMAL GIVEN THE PACIFIC ORIGINS OF THE INCOMING AIRMASS. SOME
SHOWERS OF RAIN/SNOW WILL BE POSSIBLE ACROSS NORTHERN AREAS...ESP
EARLY...ALONG WITH PARTLY TO MOSTLY CLOUDY SKIES. HOWEVER...SKIES
SHOULD CLEAR FROM SOUTH TO NORTH IN THE AFTERNOON. EXPECT TEMPS TO
REACH THE LOWER/MID 40S IN VALLEYS...AND MID 30S TO AROUND 40
ACROSS HIGHER ELEVATIONS.
SUN NT-MON...GENERALLY FAIR...WITH ABOVE NORMAL TEMPS. EXPECT MINS
TO FALL INTO THE 20S...AND MON MAXES REACHING THE LOWER/MID 40S IN
MOST AREAS. SOME CLOUDS WILL INCREASE LATE MONDAY IN ADVANCE OF
THE NEXT SYSTEM.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
THE LONG TERM PERIOD WILL BE CHARACTERIZED BY SLIGHTLY ABOVE NORMAL
TEMPERATURES AND QUICK MOVING STORM SYSTEMS BRINGING CHANCES FOR
RAIN/SNOW SHOWERS.
AT THE START OF THE LONG TERM PERIOD...A LARGE AMPLITUDE UPPER-LEVEL
PATTERN WILL BE IN PLACE ACROSS MUCH OF THE CONUS...WITH A LONGWAVE
TROUGH ACROSS THE CENTRAL CONUS AND MEAN RIDGING/SOUTHWEST FLOW
ACROSS THE EASTERN THIRD OF THE NATION. AT THE SURFACE...AN AREA OF
LOW PRESSURE WILL BE TAKING SHAPE ACROSS THE LOWER MISSISSIPPI RIVER
VALLEY.
THERE CONTINUES TO BE SIGNIFICANT UNCERTAINTY REGARDING THE
EVOLUTION OF THIS SYSTEM...PARTICULARLY IN THE EVOLUTION OF A PAIR
OF DISTURBANCES ASSOCIATED WITH THE NORTHERN AND SOUTHERN STREAMS.
THE 12Z GFS...GGEM AND MOST GEFS MEMBERS CONTINUE TO FAVOR A MORE
PROGRESSIVE SOLUTION...WITH THE NORTHERN STREAM DOMINATING AND
ALLOWING A PROGRESSIVE TROUGH AND WEAK SURFACE LOW TO MOVE THROUGH
THE REGION TUESDAY WITH CHANCES FOR RAIN/SNOW SHOWERS.
MEANWHILE...THE 12Z ECMWF CONTINUES TO BE SLOWER FAVORING A SOUTHERN
STREAM DOMINATED SURFACE LOW THAT QUICKLY RACES UP THE EASTERN
SEABOARD AND THEN PHASES WITH THE NORTHERN STREAM...ALLOWING FOR A
RATHER DEEP AND DYNAMIC SYSTEM TO PRODUCE WIDESPREAD PRECIPITATION
ACROSS THE REGION.
GIVEN LONG RANGE GUIDANCE DIFFICULTY IN HANDLING LARGE AMPLITUDE
PATTERNS IN THE EXTENDED...HAVE GONE WITH CHANCE POPS FOR
TUESDAY...SIDING CLOSE TO WPC GUIDANCE WHICH FAVORS A LOW PRESSURE
SYSTEM TRACKING ACROSS THE REGION WITH RAIN/SNOW SHOWERS MONDAY
NIGHT TRANSITIONING TO PRIMARILY RAIN DURING THE DAY TUESDAY.
THIS SYSTEM QUICKLY EXITS TUESDAY NIGHT...LEAVING SCATTERED SNOW
SHOWERS AND A BROAD UPPER-LEVEL TROUGH IN ITS WAKE. A SERIES OF
DISTURBANCES WILL MOVE THROUGH THIS TROUGH LEADING TO ADDITIONAL
CHANCES FOR RAIN/SNOW SHOWERS WEDNESDAY BEFORE TRANSITIONING TO ALL
SNOW FOR WEDNESDAY NIGHT. BOTH THE 12Z GFS AND ECMWF HINT AT THE
POTENTIAL FOR COASTAL LOW DEVELOPMENT WEDNESDAY NIGHT INTO
THURSDAY...WHICH COULD ENHANCE SNOWFALL POTENTIAL ESPECIALLY EAST OF
THE CAPITAL DISTRICT. WILL CONTINUE TO GO WITH CHANCE POPS
THROUGHOUT THIS TIMEFRAME AS MODEL UNCERTAINTY REMAINS HIGH.
WEAK HIGH PRESSURE WILL BUILD ACROSS THE REGION FOR
THURSDAY...BRINGING DRY WEATHER AND CLEARING SKIES TO MUCH OF THE
REGION BEFORE ANOTHER UPPER-LEVEL DISTURBANCE DIVING OUT OF THE
GREAT LAKES REGION APPROACHES THE REGION TO END THE WORK WEEK. MODEL
GUIDANCE CONTINUES TO INDICATE THAT THIS SYSTEM WILL HAVE LITTLE
MOISTURE TO WORK WITH...HOWEVER IT WILL BRING A REINFORCING SHOT OF
COLD AIR TO THE REGION FOR THE WEEKEND.
HIGHS WILL INITIALLY RANGE FROM THE UPPER 30S TO UPPER 40S
TUESDAY...BEFORE COOLING SLIGHTLY TO BETWEEN THE UPPER 20S AND MID
30S FOR THE REMAINDER OF THE WORK WEEK. LOWS WILL INITIALLY BE IN
THE LOW TO MID 30S ACROSS THE REGION MONDAY AND TUESDAY
NIGHT...BEFORE COOLING AND SETTLING INTO THE UPPER TEENS TO MID 20S
FOR THE REMAINDER OF THE WORK WEEK.
&&
.AVIATION /21Z FRIDAY THROUGH WEDNESDAY/...
A RIDGE OF HIGH PRESSURE WILL CONTINUE TO MOVE EAST INTO THE
NORTHERN ATLANTIC OCEAN. A COLD FRONT FROM THE OHIO VALLEY WILL
CONTINUE TO MOVE EAST TOWARD OUR REGION. AHEAD OF THE APPROACHING
COLD FRONT...A WEAK WARM FRONT WILL BRING THE CHANCE OF
PRECIPITATION TO ALL THE TAF SITES. TEMPERATURES WILL SUPPORT A
WINTRY MIX ESPECIALLY AT KPSF/KALB/KGFL FROM 03Z TO 09Z SATURDAY AT
KALB/KPSF EXTENDING TO AS LATE AS 12Z SATURDAY AT KGFL.
PRECIPITATION TYPE WILL CHANGE TO ALL RAIN AFTER 12Z SATURDAY AT ALL
TAF SITES. THE MAIN COLD FRONT TO OUR WEST WILL NOT BE MOVING INTO
THE REGION UNTO AFTER THE END OF THE TAF FORECAST PERIOD AFTER 18Z
SATURDAY.
WINDS WILL BE OUT OF THE SOUTHWEST TO START THE TAF PERIOD UP TO 00Z
SATURDAY. WINDS WILL THEN SHIFT TO A SOUTH-SOUTHEASTERLY FLOW BEHIND
THE WARM FRONT PASSAGE WITH WINDS BETWEEN 5-10 KTS. AT TIMES ALONG
AND AHEAD OF THE FRONTAL PASSAGE...KGFL MAY EXPERIENCE SOME LLWS
ESPECIALLY TOWARD THE END OF THE TAF PERIOD.
VFR/MVFR CONDITIONS ARE EXPECTED UP TO 00Z SATURDAY WHICH WILL BE
FOLLOWED BY MVFR CONDITIONS. AT TIMES...IFR CONDITIONS MAY BE
PRESENT BETWEEN 06Z AND 12Z SATURDAY AS THE WARM FRONT WILL MAKE ITS
WAY INTO THE REGION WITH WINTRY PRECIPITATION AND LOW VSBYS AND
CEILINGS.
OUTLOOK...
SAT NT: HIGH OPERATIONAL IMPACT.BREEZY DEFINITE SHRA...RA...FG.
SUN: MODERATE OPERATIONAL IMPACT. WINDY WITH GUSTS TO 34.0 SLIGHT
CHANCE OF SHRA.
SUN NT-MON: NO OPERATIONAL IMPACT. NO SIG WX.
MON NT-WED: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...SHSN.
&&
.HYDROLOGY...
A FLOOD WATCH REMAINS IN EFFECT FOR SATURDAY AFTERNOON THROUGH
SUNDAY...WITH THE PRIMARY THREAT ICE JAM FLOODING.
A POWERFUL STORM SYSTEM WILL MOVE ACROSS THE REGION SATURDAY WITH
VERY MILD AIR BEING USHERED IN AS THE SYSTEM APPROACHES WITH
TEMPERATURES RISING INTO THE UPPER 40S TO LOWER 50S. THIS WILL LEAD
TO SOME SNOW MELT. SOME MIXED WINTRY PRECIPITATION IS EXPECTED LATE
TONIGHT INTO EARLY SATURDAY MORNING...THEN RAIN IS EXPECTED
INTO SATURDAY NIGHT. THE RAIN MAY BE HEAVY AT TIMES DURING THE
AFTERNOON AND EVENING HOURS. RAINFALL AMOUNTS OF ONE HALF OF AN INCH
TO AN INCH ARE EXPECTED FROM THE CAPITAL DISTRICT NORTH AND WEST
WITH 1 TO 2 INCHES TO THE SOUTH AND EAST.
THE RAIN WILL FALL ON FROZEN GROUND WHICH WILL QUICKLY BECOME RUNOFF
AND MAY CAUSE SOME STREET AND OR POOR DRAINAGE FLOODING OF LOW LYING
AREAS. THE WARM TEMPERATURES...COMBINED WITH THE RAINFALL MAY
CAUSE ICE MOVEMENT AND BREAK UP FOR ICE JAM FLOODING ON SOME
RIVERS AND STREAMS. THE THREAT FOR ICE JAM FLOODING WILL BE
GREATEST LATE SATURDAY AFTERNOON INTO SUNDAY.
IT APPEARS THAT THE GREATEST POTENTIAL FOR FLOODING AT THIS TIME
WILL INCLUDE...BUT NOT BE LIMITED TO...THE HOOSIC RIVER AT
WILLIAMSTOWN AND EAGLE BRIDGE...AND THE WALLOOMSAC RIVER AT
BENNINGTON.
DESPITE THE PASSAGE OF THE SYSTEM...ABOVE NORMAL TEMPERATURES ARE
EXPECTED TO PERSIST THROUGH EARLY NEXT WEEK. NIGHTTIME
TEMPERATURES WILL FALL TO AROUND FREEZING OR BELOW. OUR NEXT BEST
CHANCES FOR WIDESPREAD PRECIPITATION WILL TUESDAY.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...FLOOD WATCH FROM SATURDAY AFTERNOON THROUGH SUNDAY AFTERNOON
FOR CTZ001-013.
FREEZING RAIN ADVISORY FROM 10 PM THIS EVENING TO 4 AM EST
SATURDAY FOR CTZ001-013.
NY...FLOOD WATCH FROM SATURDAY AFTERNOON THROUGH SUNDAY AFTERNOON
FOR NYZ032-033-038>043-047>054-058>061-063>066-082>084.
FREEZING RAIN ADVISORY FROM 10 PM THIS EVENING TO 4 AM EST
SATURDAY FOR NYZ063>066.
FREEZING RAIN ADVISORY FROM MIDNIGHT TONIGHT TO 6 AM EST
SATURDAY FOR NYZ047>054-058>061.
FREEZING RAIN ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM EST
SATURDAY FOR NYZ032-033-038>043-082>084.
MA...FLOOD WATCH FROM SATURDAY AFTERNOON THROUGH SUNDAY AFTERNOON
FOR MAZ001-025.
FREEZING RAIN ADVISORY FROM MIDNIGHT TONIGHT TO 6 AM EST
SATURDAY FOR MAZ001-025.
VT...FLOOD WATCH FROM SATURDAY AFTERNOON THROUGH SUNDAY AFTERNOON
FOR VTZ013>015.
FREEZING RAIN ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM EST
SATURDAY FOR VTZ013>015.
&&
$$
SYNOPSIS...IAA/KL
NEAR TERM...KL
SHORT TERM...KL
LONG TERM...IRL
AVIATION...LFM
HYDROLOGY...KL/IAA/WASULA
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
318 PM EST FRI JAN 10 2014
.DISCUSSION...
TONIGHT...
EXPECT A SLIGHT CHANCE FOR SHOWERS TO LINGER INTO THE EARLY
EVENING BUT OTHERWISE SKIES SHOULD BECOME PARTLY CLOUDY FOR A
TIME. THE LOW LEVELS WILL REMAIN VERY MOIST AND EXPECT THAT LOW
STRATUS WILL DEVELOP DURING THE LATE AFTERNOON AND OVERNIGHT.
INCREASING WINDS JUST OFF THE SURFACE SHOULD INHIBIT FOG...BUT
WILL CONTINUE OUR PREVIOUS FORECAST THAT MENTIONS PATCHY FOG.
SOUTHERLY FLOW WILL KEEP MINIMUM TEMPS WELL ABOVE NORMAL...
IN THE MID TO UPPER 60S.
SAT...
FRONTAL BOUNDARY IS PROGGED TO BE ENTERING THE WESTERN PANHANDLE
EARLY AND PUSHING THROUGH THE BIG BEND REGION TOWARDS EARLY
EVENING. THOUGH LOW LEVEL WINDS WILL BE INCREASING AS THE FRONT
APPROACHES...THEY WILL BE VEERING TO THE SOUTHWEST...DECREASING
CONVERGENCE. THE GFS ALSO SHOWS THAT THIS SOUTHWEST FLOW WILL TAP
DRIER AIR THAT RESIDES OVER THE NORTHWEST CARIBBEAN. THE RESULT
FROM THE MODEL IS VERY LOW PRECIP AMOUNTS. BASED ON QUITE HIGH DEW
POINTS THOUGH...WILL RETAIN CHANCE POPS WITH VALUES AT 50 PERCENT
IN THE NORTH AND 30 IN THE SOUTH. HAVE TRIMMED THUNDER CHANCES
BACK TO NORTHERN SECTIONS...JUST AHEAD OF THE FRONT.
THE WARM SOUTHWEST FLOW WILL BOOST MAX TEMPS INTO THE 80S. LATEST
MOS HAS LOWER 80S NORTH AND MID 80S SOUTH. IF THE MORNING STRATUS
BREAKS UP FAST ENOUGH AND PRE FRONTAL PRECIP HOLDS OFF LONG
ENOUGH...A FEW SPOTS COULD APPROACH THEIR RECORD HIGHS.
SAT NIGHT...
A 130KT H30-H20 JET STREAK DIGGING ACRS THE NW CONUS WILL COMBINE
WITH A 110KT JET LIFTING OUT OF THE RIO GRANDE VALLEY TO SHUNT THE
NEXT SHORT WAVE FRONTAL TROF THROUGH CENTRAL FL. WHILE THE COMBO OF
THESE TO UPR LVL FEATURES WILL PROVIDE SUFFICIENT ENERGY TO DRIVE
THE FRONTAL BOUNDARY INTO S FL BY DAYBREAK...A STRONG MID LVL
ANTICYCLONE OVER THE BAHAMA BANK/NW CARIB WILL DEFLECT THE MAJORITY
OF THE SYSTEM ENERGY TO THE N. FURTHERMORE...MODEL SOUNDINGS ARE
INDICATING A SIGNIFICANT AMOUNT OF DRY AIR THRU THE H85-H60 LYR WITH
DEWPOINT DEPRESSIONS ON THE ORDER OF 10C IMMEDIATELY PRECEDING THE
FROPA.
THE FCST SOLUTION IS NOT UNREASONABLE...GIVEN THE FACT THAT THE
LATEST RUC ANALYSIS SHOWS H85-H70 MEAN RH VALUES AS LOW AS 40PCT.
FURTHERMORE...THE LIFTING NATURE OF THE LEADING JET STREAK TYPICALLY
IS NOT CONDUCIVE TO SIGNIFICANT OUTBREAKS OF STRONG/SVR WX.
FINALLY...DEEP LYR LAPSE RATES ACRS THE GOMEX/SW ATLC ARE RATHER
WEAK...GENERALLY AOB 6C/KM. WILL KEEP POPS IN THE 30-40PCT RANGE...
SHIFTING FOCUS FOR TSRA ACTIVITY FROM THE NRN CWA BTWN 00Z-06Z...AND
THE SRN CWA TO 06Z-12Z TO COINCIDE WITH THE FROPA.
TIMING OF THE FROPA WILL RESULT IN A FAIRLY WIDE MIN TEMP SPREAD.
AREAS ALONG AND N OF I-4 WILL SEE MINS DROP INTO THE M/U50S DUE TO
THEIR LONGER DURATION POST FRONTAL COOL AIR ADVECTION...WHILE AREAS
ALONG THE TREASURE COAST WILL HOLD IN THE M/U60S AS THE CRUX OF THE
COLD AIR WILL NOT HAVE MADE IT THAT FAR SOUTH BY DAYBREAK.
SUN-SUN NIGHT...
PROGRESSIVE WX PATTERN WILL PUSH THE POST FRONTAL HIGH PRES RIDGE
ACRS THE GOMEX/DEEP SOUTH THRU THE DAY...THEN WELL INTO THE W ATLC
BY DAYBREAK MON. MODERATE H100-H85 FLOW WILL RESPOND BY SHIFTING
STEADILY FROM NW AT DAYBREAK...TO DUE N BY MIDDAY...TO THE E/NE BY
SUNSET...THEN FINALLY TO THE SE OVERNIGHT.
SHORT DURATION OF THE NRLY FLOW WILL LIMIT THE EFFECTS OF THE POST
FRONTAL RIDGE TO THE SUN/SUN NIGHT TIME FRAME...GENERALLY RETURNING
TEMPS TO NEAR CLIMO AVG FOR EARLY JAN. MAX TEMPS WILL BE IN THE
U60S/L70S ALONG AND N OF I-4 AND L/M70S TREASURE COAST AND THE NE
SHORE OF LAKE OKEECHOBEE. DVLPG ONSHORE FLOW WILL KEEP MIN TEMPS
ALONG THE IMMEDIATE SPACE/TREASURE COASTS IN THE U50S/L60S...BUT ARE
NOT EXPECTED TO BE STRONG ENOUGH TO KEEP INTERIOR TEMPS FROM
DROPPING INTO THE U40S/L50 N OF I-4 AND INTO THE L/M50S TO THE S
(AGAIN...NEAR CLIMO AVG).
EXTENDED...(PREV DISC)
SPLIT TROUGH MOVES THROUGH THE CENTRAL AND EASTERN US THROUGH THE
EARLY PART OF THE WEEK WITH THE SOUTHERN BRANCH DRIVING CYCLOGENESIS
SOMEWHERE BETWEEN THE SOUTHERN MISSISSIPPI VALLEY AND OHIO VALLEY...
DEPENDING ON THE MODEL. THE ECMWF DEVELOPS A STRONGER AND MORE
COHESIVE SYSTEM THAT LIFTS INTO THE MID-ATLANTIC ON TUESDAY...WHILE
THE GFS KEEP A STRONG LOW OVER THE GREAT LAKES AND BROADER
TROUGH/LOW PRESSURE ACROSS THE DEEP SOUTH. AS A RESULT...THE GFS IS
QUICKER TO BRING A RETURN OF RAIN AND MOVE A FRONT THROUGH TUES
NIGHT. ECMWF IS SIMILAR ON THE TIMING OF THE ACTUAL FRONT...BUT
HOLDS OF ANY NOTABLE RAIN CHANCES UNTIL TUESDAY. HAVE BROADBRUSHED
20 POPS ON MONDAY TO TUESDAY TO ACCOUNT FOR THE DIFFERENCES.
COOLER AND DRY WEATHER IS EXPECTED BEHIND THE FRONT DURING THE DAY
ON WEDNESDAY.
&&
.AVIATION...PRESENT CONDITIONS HAVE GONE VFR EVERYWHERE EXCEPT FOR
LOCAL MVFR WHERE ISOLATED SHOWERS WERE OCCURRING ALONG THE
TREASURE COAST. THE MAIN AVIATION CONCERN WILL AGAIN BE LATE NIGHT
LOW STRATUS. SOUTHERLY LOW LEVEL WINDS LOOK STRONG ENOUGH TO
INHIBIT DENSE FOG...BUT SOME LIFR CEILINGS COULD OCCUR ESPECIALLY
ALONG AND WEST OF THE I-4 CORRIDOR.
&&
.MARINE...
TONIGHT...WEAKNESS IN PRESSURE GRADIENT WAS OVER THE WATERS BEHIND
THE WEAKENING SURFACE TROUGH THAT HAS LIFTED TO THE NORTH. THIS
WILL BE TEMPORARY THOUGH AS THE PRESSURE GRADIENT WILL START TO
TIGHTEN BACK UP IN ADVANCE OF FRONTAL TROUGH THAT WILL BE REACHING
NEAR THE FLORIDA PANHANDLE TOWARDS SUNRISE. WILL EXPIRE THE
OFFSHORE ADVISORY WITH NEXT FORECAST ISSUANCE...THOUGH SEAS MAY
ACTUALLY BE AROUND 7 FEET AT THAT TIME. WILL MENTION EXERCISE
CAUTION FOR THE OFFSHORE LEGS THOUGH.
SAT...SOUTH WINDS STARTING OUT THE DAY WILL SHIFT TO THE SOUTHWEST
IN THE AFTERNOON. MARINE MOS INDICATES SPEEDS REACHING 20 KNOTS
TOWARDS EVENING AT 41009. SINCE THIS IS A WARM ADVECTION PATTERN
(OVER COOL CONTINENTAL SHELF WATERS) AND THERE WILL BE LIMITED
FETCH WHEN THE SPEEDS INCREASE LATE...WILL HOLD OFF ON AN ADVISORY
WITH THIS PACKAGE...BUT EXPECT ONE MAY BE NEEDED OFFSHORE SAT
NIGHT.
SAT NIGHT...POOR BOATING CONDITIONS AS A COLD FRONT PUSHES RAPIDLY
ACRS THE LCL ATLC. MODERATE TO FRESH SW BREEZE AT SUNSET WILL VEER
STEADILY TO THE W BY AROUND MIDNIGHT...THEN TO THE NW BY DAYBREAK.
OFFSHORE COMPONENT WILL LIMIT SEA HEIGHTS TO 3-5FT NEARSHORE AND
4-6FT OFFSHORE...UP TO 7FT OVER THE GULF STREAM N OF SEBASTIAN INLET.
SUN-SUN NIGHT...PROGRESSIVE WX PATTERN WILL PUSH THE POST FRONTAL HI
PRES RIDGE INTO THE W ATLC THRU THE PD. SFC/BNDRY LYR WINDS WILL
RESPOND BY VEERING AROUND THE CLOCK...MODERATE TO FRESH NW BREEZE
AT DAYBREAK...DIMINISHING TO GENTLE TO MODERATE NRLY BREEZE BY
MIDDAY...LIGHT TO GENTLE NE BREEZE BY SUNSET...VEERING TO E/SE
OVERNIGHT. SHORT DURATION OF THE ENHANCED WIND FIELD WILL LIMIT SEA
HEIGHTS TO 3-5FT NEARSHORE AND 5-7FT OFFSHORE AROUND DAYBREAK...
DECREASING TO 2-4FT NEARSHORE AND 3-5FT OFFSHORE AROUND SUNSET...
THEN 2-4FT AREAWIDE OVERNIGHT.
MON-TUE...(PREV DISC)
PROGRESSIVE PATTERN BRING FLOW AROUND TO THE SOUTHEAST 5-10KTS ON
MONDAY...BEFORE INCREASING FROM THE SOUTH MONDAY NIGHT AHEAD OF THE
NEXT FRONT. SOME TIMING DIFFERENCE BETWEEN MODELS...BUT APPEARS THAT
THE ACTUAL WIND SHIFT WILL HOLD OFF UNTIL TUESDAY NIGHT...LEAVING
WEST-SOUTHWEST WINDS 15-20KTS DURING THE DAY ON TUESDAY.
ANOTHER...MORE PROLONGED NORTHWEST WINDS SURGE EXPECTED STARTING
TUES NIGHT BEHIND FRONT.
LIGHT WINDS WILL KEEP SEAS 2-4FT ON MONDAY...THOUGH THE STRONGER
OFFSHORE COMPONENT INTO TUES WILL BUILD SEAS UP TO 6FT WELL OFFSHORE
NORTH OF THE CAPE BY LATE TUE INTO WED.
&&
.CLIMATE...
RECORD HIGHS FOR TOMORROW...
DAB 84 SET IN 1991
MCO 86 SET IN 1972
MLB 87 SET IN 1975
VRB 84 SET IN 1972
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 65 83 55 66 / 20 50 40 0
MCO 64 83 58 71 / 20 40 40 0
MLB 70 84 63 70 / 20 30 40 0
VRB 69 84 65 71 / 20 30 30 0
LEE 65 80 55 68 / 20 50 40 0
SFB 65 83 57 70 / 20 50 40 0
ORL 65 82 58 71 / 20 40 40 0
FPR 68 84 65 71 / 20 30 30 0
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM...LASCODY
IMPACT WX....BRAGAW
AREA FORECAST DISCUSSION
NWS MIAMI FL
304 AM EST FRI JAN 10 2014
.AVIATION...
HEAVY RAINFALL CONTINUES TO IMPACT THE COASTAL AND METRO AREAS OF
PALM BEACH COUNTY THIS MORNING. THE HRRR MODEL REFLECTIVITIES
INITIALIZE WELL WITH THIS ACTIVITY AND INDICATE IT CONTINUING
THROUGH DAYBREAK BEFORE DIMINISHING. AS A RESULT...WILL KEEP THE
TEMPO IN THE PBI TAF THROUGH 12Z DUE TO VSBYS/CIGS/WX.
ELSEWHERE...VFR CONDITIONS WILL PERSIST THROUGH THE MUCH OF THE
PERIOD WITH LIGHT SOUTHEAST FLOW CONTINUING.
&&
.PREV DISCUSSION... /ISSUED 643 PM EST THU JAN 9 2014/
AVIATION...
THE WARM FRONT THAT HAS BEEN PRODUCING SCATTERED SHOWERS
THROUGHOUT THE DAY WILL CONTINUE TO MOVE NORTHWARD THROUGH
TONIGHT. LEFT VCSH IN ACROSS ALL TERMINALS THROUGH FRIDAY MORNING,
HOWEVER, MOST OF THE SHOWER ACTIVITY WILL REMAIN ACROSS NORTHERN
AREAS THIS EVENING ESPECIALLY NEAR KPBI. PATCHY FOG MAY DEVELOP
LATE TONIGHT INTO EARLY FRIDAY MORNING AT KAPF AS ENOUGH LOW LEVEL
MOISTURE WILL REMAIN IN PLACE. WINDS WILL CONTINUE TO DIMINISH AS
THE EVENING PROGRESSES. THE WARM FRONT WILL CONTINUE TO MOVE NORTH
ON FRIDAY AND WINDS WILL REMAIN OUT OF THE SOUTHEAST ACROSS ALL
TERMINALS.
PREV DISCUSSION... /ISSUED 246 PM EST THU JAN 9 2014/
SYNOPSIS...
RAIN CHANCES GRADUALLY DECLINE FOR THE REST OF THE WEEK...WITH
VERY WARM CONDITIONS PREVAILING. A WEAK COLD FRONT WILL MOVE
THROUGH SATURDAY NIGHT.
SHORT TERM /TONIGHT THROUGH SUNDAY/...
ISENTROPIC LIFT AND MODEST CONVERGENCE CONTINUE TO INTERACT WITH
ABUNDANT DEEP-LAYER MOISTURE TO PRODUCE NUMEROUS SHOWERS ACROSS
MUCH OF SOUTH FLORIDA. OVERCAST CONDITIONS HAVE LIMITED
INSTABILITY THUS FAR...BUT CANT RULE OUT SOME BREAKS IN CLOUDS
LATE THIS AFTERNOON...SO WILL KEEP ISOLATED THUNDER IN GRIDS NEAR
EAST COAST AND ATLANTIC WATERS. THE CLOUDINESS HAS SUPPRESSED
WARMING SOMEWHAT...KEEPING MAXIMA IN 70S MOST AREAS.
DEEPEST MOISTURE AXIS WILL INCH NORTHWARD OVERNIGHT...FOCUSING
OVER CENTRAL FLORIDA BY FRIDAY. THIS SHOULD LEAD TO A DECLINE IN
SHOWER COVERAGE...BUT VERY MOIST AND WARM AIRMASS WILL STILL
SUPPORT SCATTERED SHOWERS THROUGH FRIDAY. AS HIGH PRESSURE NEAR
THE NORTHEAST CONUS COAST DRIFTS EASTWARD...LOW-LEVEL FLOW OVER
SOUTH FLORIDA WILL TRANSITION FROM EASTERLY TO SOUTHEASTERLY...AND
DIMINISH SLIGHTLY OVER TIME.
FAVORING FOG FORMATION TONIGHT ARE NEAR-SATURATED BOUNDARY
LAYER...CALM WINDS...AND SLIGHT MOISTURE ADVECTION FROM THE
SOUTHEAST. INHIBITING FOG WILL BE NEAR-OVERCAST CONDITIONS AND
SCATTERED SHOWERS. THESE CONFLICTING FACTORS MAKES FOG FORECAST
DIFFICULT. HAVE ELECTED TO KEEP PATCHY FOG IN GRIDS MOST INLAND
AND WEST COAST AREAS LATE TONIGHT.
TEMPERATURES THROUGH SATURDAY WILL BE WELL ABOVE NORMAL...WITH
MINIMA IN THE 60S TO LOW 70S. WITH SLIGHTLY MORE SUNSHINE
EXPECTED...MAXIMA SHOULD REACH LOW 80S MOST AREAS.
WINDS SATURDAY WILL INCREASE OUT OF THE SOUTH IN ADVANCE OF A MID-
LATITUDE SHORTWAVE TROUGH AND ATTENDANT COLD FRONT. THE COLD FRONT
WILL APPROACH LATE SATURDAY AND CROSS SATURDAY NIGHT. BETTER
DYNAMICS WILL RESIDE WELL NORTH OF THE AREA...BUT DIURNAL
CONVECTION COULD DEVELOP ALONG THE FRONT OVER CENTRAL FLORIDA.
RIGHT NOW...TIMING OF FROPA LOOKS TO BE LATE ENOUGH OVER CENTRAL
FLORIDA SUCH THAT WEAK INSTABILITY WILL PRECLUDE MUCH IN THE WAY
OF THUNDER. LITTLE/NO COOL AIR IS EXPECTED BEHIND THIS FRONT FOR
SUNDAY.
LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
LONG RANGE MODELS ARE STILL SHOWING ANOTHER COLD FRONT MOVING THROUGH
SOUTH FLORIDA EARLY NEXT WEEK WITH HIGH PRESSURE BUILDING INTO
THE AREA FOR MIDDLE TO END OF NEXT WEEK. THIS FRONT WILL BRING DRIER
AND COOLER WEATHER TO SOUTH FLORIDA FOR THE MIDDLE TO END OF NEXT
WEEK. TEMPERATURES SHOULD REMAIN NEAR NORMAL FOR THIS TIME OF
YEAR WITH HIGHS IN THE 70S AND LOWS IN THE 40S EXCEPT 50S OVER THE
EAST COAST METRO AREAS.
AVIATION...
PREVAILING MVFR CONDITIONS ARE EXPECTED FOR THE EAST COAST TAF
SITES THROUGH THE AFTERNOON HOURS. BRIEF IFR CONDITIONS ARE
POSSIBLE IN SHOWERS. A CONVERGENT LINE OF MODERATE SHOWERS
DEVELOPED ACROSS SOUTHERN BROWARD COUNTY EARLY THIS
AFTERNOON...AND THIS WILL CONTINUE TO SLOWLY DRIFT NORTH. BY 19Z
IT SHOULD MOVE NORTH OF KFLL AND MOVE TO KFXE. ELSEWHERE FOR THE
EAST COAST TAF SITES...SCATTERED SHOWERS WILL CONTINUE TO MOVE
INTO THE COAST. SHALLOW RAIN SHOWERS APPEAR TO HAVE MOVED INTO
KAPF...AND IFR CONDITIONS WERE OCCURRING. THESE SHOWERS WERE NOT
SHOWING UP ON THE RADAR. A SHORTWAVE WAS NOTED IN THE VISIBLE
IMAGERY JUST TO THE WEST OF NAPLES...AND THIS IS LIKELY
RESPONSIBLE FOR THE LOWER CIGS AND RAINFALL. THE WARM FRONT WAS
LOCATED ACROSS SOUTH FLORIDA NEAR THE BROWARD /MIAMI- DADE
LINE...AND THIS BOUNDARY WILL SLOWLY SLIDE NORTH THROUGH THE DAY
TODAY. SHOWERS MAY CONTINUE AT KAPF AND KPBI FOR MUCH OF THE
NIGHT...AND KEPT VCSH ELSEWHERE. EASTERLY WINDS 10-15 KNOTS WILL
CONTINUE...AND ARE EXPECTED TO DIMINISH THIS EVENING...ESPECIALLY
SOUTH. THE BOUNDARY WILL CONTINUE TO MOVE NORTH ON FRIDAY...AND
WINDS WILL SHIFT TO THE SOUTHEAST. ONLY ISOLATED SHOWERS ARE IN
THE FORECAST...SO DID NOT MENTION IN THE TAFS ON FRIDAY AT THIS
TIME.
MARINE...
WINDS OFF PALM BEACH COUNTY HAVE REMAINED AROUND 20 KNOTS THIS
AFTERNOON...SO HAVE EXTENDED ADVISORY UNTIL 0Z. ELSEWHERE...15-20
KNOT EAST WINDS WARRANT SMALL CRAFT TO EXERCISE CAUTION. WINDS
SHOULD TURN SOUTHEAST OVERNIGHT THEN TURN SOUTHERLY ON FRIDAY AT
SPEEDS OF 10-15 KTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 81 72 83 68 / 30 20 30 20
FORT LAUDERDALE 81 74 82 71 / 30 20 30 20
MIAMI 83 73 84 71 / 30 20 20 10
NAPLES 82 67 82 68 / 30 20 30 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...54/BNB
AVIATION/RADAR...85/AG
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
903 PM EST SAT JAN 11 2014
.SYNOPSIS...
A COLD FRONT WILL MOVE OFFSHORE THIS EVENING. HIGH PRESSURE WILL
BUILD SUNDAY AND QUICKLY MOVE OFF THE COAST MONDAY...BEFORE A WEAK
COLD FRONT MOVES THROUGH THE AREA BY TUESDAY MORNING. A STRONGER
COLD FRONT IS EXPECTED WEDNESDAY NIGHT WITH YET ANOTHER WEAK COLD
FRONT POSSIBLE FRIDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
THE COLD FRONT WAS MARCHING THROUGH EAST CENTRAL GEORGIA AT 9 PM
AND WILL CONTINUE TO MOVE STEADILY EAST...PASSING OFFSHORE BY
MIDNIGHT. STILL SOME STRONG UPPER FORCING PROGGED TO RIPPLE BY
OVER THE NEXT 2-3 HOURS BUT THE DEEPER MOISTURE AND INSTABILITY
NOW OFF THE COAST. WE HAVE MAINTAINED 20-30 POPS A LITTLE WHILE
LONGER AS A FEW CLUSTERS OF LOW-TOPPED CONVECTIVE RAINS ROLL
THROUGH THE FORECAST AREA. MSAS AND RUC ANALYSIS SUGGESTS THERE
IS A POTENTIAL FOR SOME ISOLATED THUNDER PRIOR TO MIDNIGHT JUST
AHEAD OF THE COLD FRONT...RISK FOR ANY STRONG CONVECTION LOOKS
PRETTY NIL.
COLD AIR ADVECTION WILL KICK IN AFTER THE FROPA WITH SOME BRIEF
GUSTY CONDITIONS POSSIBLY AT TIMES AS SURFACE PRES STARTS TO
INCREASE AT A STEADY CLIP. VERY LITTLE CHANGES TO LOW TEMPS
WHICH WILL OCCUR IN THE 12Z TIME FRAME. SKIES WILL CLEAR RAPIDLY
AS STRONG MID LEVEL SUBSIDENCE EXPANDS OVER THE REGION FROM W
TO E.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
SUNDAY...DRY HIGH PRESSURE WILL BUILD IN THE WAKE OF THE
DEPARTING COLD FRONT...YET PROGRESSIVE FLOW ALOFT WILL PULL THE
CENTER OF THE HIGH QUICKLY TOWARD THE NEARBY ATLANTIC WATERS. COLD
ADVECTION WILL BE WEAK BEHIND THE FRONT...AND WITH WIND DIRECTIONS
REMAINING GENERALLY WEST/SOUTHWEST...EXPECT ONLY A SLIGHT COOLING
TREND TO OCCUR. HIGH TEMPERATURES IN THE MID TO UPPER 60S WILL BE
COOLER THAN THE PREVIOUS DAY...YET STILL BE WELL ABOVE SEASONAL
NORMALS. AN AMPLIFYING LONG WAVE TROUGH ACROSS THE CENTRAL PLAINS
AFTER MIDNIGHT WILL SUPPORT BRIEF DOWNSTREAM HEIGHT RISES...AND
WHEN COMBINED WITH WARM ADVECTION WITHIN BACKING LOW LEVEL
FLOW...LOW TEMPERATURES IN THE UPPER 30S INLAND TO LOW 40S NEAR
THE COAST WILL ALSO BE SEVERAL DEGREES WARMER THAN AVERAGE.
MONDAY...SOUTHERN STREAM SHORTWAVE ENERGY TRACKING ACROSS THE GULF
OF MEXICO WILL SPIN UP A SURFACE WAVE ALONG THE WESTERN PERIPHERY
OF THE RETREATING ATLANTIC HIGH PRESSURE. THERE REMAINS NOTABLE
DISAGREEMENT BETWEEN MODEL SOLUTIONS REGARDING THE STRENGTH AND
TRACK OF THIS LOW PRESSURE WAVE AND TRAILING FRONT AS THEY
PROGRESS TOWARD THE FORECAST AREA THROUGH THE DAY. IN GENERAL...A
SOLID TAP INTO GULF MOISTURE WILL SUPPORT A SWATH OF PRECIPITATION
ASSOCIATED WITH THE SYSTEM...AND EXPECT RAIN CHANCES TO INCREASE
FROM SOUTHWEST TO NORTHEAST DURING THE LATE AFTERNOON TO EVENING
TIME FRAME. WARM ADVECTION AND PRE-FRONTAL COMPRESSION WILL
SUPPORT TEMPERATURES PEAKING IN THE MID TO UPPER 60S...EVEN AS
CLOUD COVER GRADUALLY INCREASES. THE BEST RAIN POTENTIAL ACTUALLY
APPEARS TO OCCUR OVERNIGHT INTO EARLY TUESDAY MORNING..AS THE
SURFACE LOW LIFTS NORTH/NORTHEAST AND PULLS THE FRONT INTO THE
REGION. LOW TEMPERATURES WILL BE QUITE MILD AS A RESULT...ONLY
FALLING INTO THE UPPER 40S TO AROUND 50 DEGREES.
TUESDAY...THE SYNOPTIC PATTERN REMAINS A BIT UNSETTLED EVEN AFTER
THE FRONT MOVES OFFSHORE...WITH ANOTHER LARGE AREA OF UPPER LEVEL
ENERGY SWEEPING SOUTHEAST FROM THE GREAT LAKES REGION. RAIN
CHANCES WILL DECREASE DURING THE MORNING HOURS BEHIND THE
DEPARTING COLD FRONT. HOWEVER DRY SURFACE HIGH PRESSURE IN ITS
WAKE WILL BECOME SUPPRESSED TO THE SOUTH...AS YET ANOTHER FRONT
DRIVEN BY THE AMPLIFYING UPPER SHORTWAVE DESCENDS FROM THE OHIO
VALLEY LATE IN THE DAY. ONCE AGAIN...DOWNSLOPE FLOW AND THE LACK
OF SOLID COLD ADVECTION WILL SUPPORT ABOVE NORMAL HIGH TEMPERATURES
IN THE MID 60S.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THE DEEPENING UPPER TROUGH WILL SHIFT OVER THE EAST COAST STATES
ON WEDNESDAY...WITH A DRY COLD FRONT MOVING ACROSS THE REGION
EARLY IN THE DAY. THERE APPEARS TO BE MORE NOTABLE COLD ADVECTION
BEHIND THIS FRONT...AND EXPECT HIGH TEMPERATURES TO BE SUPPRESSED
IN THE MID 50S UNDER MOSTLY CLEAR SKIES ON WEDNESDAY. LOW
TEMPERATURES WEDNESDAY NIGHT WILL BE THE COLDEST SEEN IN
DAYS...AS LIGHT WINDS AND LITTLE TO NO CLOUD COVER SET UP IDEAL
RADIATIONAL COOLING CONDITIONS. A NEARLY ZONAL UPPER PATTERN ON
THURSDAY WILL BE RATHER TRANSIENT...AS BROAD TROUGHING BECOMES THE
DOMINANT FEATURE ALOFT FRIDAY AND SATURDAY. CONSIDERING DRY
SURFACE HIGH PRESSURE WILL ALSO SETTLE OVER THE REGION...EXPECT
TEMPERATURES TO BE GENERALLY BELOW NORMAL AND RAIN CHANCES TO
REMAIN BELOW 15 PERCENT THROUGH THE EXTENDED FORECAST PERIOD.
&&
.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
CHARLESTON SEEING PERIODS OF MVFR/IFR CIGS BEFORE THE LOWER LEVELS
DRY OUT IN THE WAKE OF THE COLD FRONT BY MIDNIGHT. MVFR CIGS AT KSAV
WILL LIKELY SCOUR OUT PRIOR TO 04Z AS MUCH DRIER PUNCHES IN FROM
THE W. RADAR TRENDS AT 02Z SUGGEST WE MAY NEED TO AMEND TO ADD A
SHORT WINDOW FOR SOME SHOWERS.
OVERNIGHT THERE COULD BE SOME WIND GUSTS 15-20 KT AS THE COOLER
AIR BEGINS TO MOVE IN BUT CONFIDENCE IN THE WINDOW FOR TIMING AND
DURING WE HAVE OPTED TO NOT INCLUDE GUSTS AT THIS TIME. AFTER
MIDNIGHT THROUGH SUNDAY...VFR CONDITIONS WILL PREVAIL.
EXTENDED AVIATION OUTLOOK...THERE IS A CHANCE OF SHOWERS/MVFR
CONDITIONS LATE MONDAY INTO EARLY TUESDAY DUE TO ANOTHER FRONTAL
SYSTEM. GUSTY SURFACE WINDS TO IMPACT THE TERMINALS WEDNESDAY.
&&
.MARINE...
TONIGHT...THE SQUALL LINE WAS NOW WELL OFFSHORE AND WILL BE
FOLLOWED BY THE COLD FRONT PASSAGE TONIGHT. WINDS WILL QUICKLY SHIFT
WEST WITH THE FRONT AND INCREASE WITH THE ONSET OF COLD AIR
ADVECTION. WINDS LOOK TO PEAK 20-25 KT NEARSHORE WATERS AND 25-30
KT OFFSHORE WATERS. CANNOT RULE OUT A FEW GALE FORCE GUSTS OVER
THE OFFSHORE WATERS. WILL MAINTAIN SMALL CRAFT ADVISORIES FOR ALL
WATERS. OFFSHORE WINDS WILL HAVE A DECAYING EFFECT OF SEAS OVER
THE NEARSHORE WATERS WITH SEAS SUBSIDING BY ABOUT 1-2 FT...BUT
SEAS OF 6-8 FT WILL LINGER OVER THE OFFSHORE WATERS WHERE THE
FETCH WILL BE CONSIDERABLY LONGER.
SUNDAY THROUGH WEDNESDAY...LINGERING SMALL CRAFT ADVISORIES WILL
BE ABLE TO END BY SUNDAY MORNING/EARLY AFTERNOON...AS SURFACE HIGH
PRESSURE RAPIDLY BUILDS OVER THE REGION IN THE WAKE OF THE COLD
FRONT. MARINE CONDITIONS WILL THEN REMAIN RATHER QUIET THROUGH THE
DAYTIME HOURS ON MONDAY. A WAVE OF LOW PRESSURE IN THE GULF OF
MEXICO WILL LIFT TOWARD THE SOUTHEAST STATES LATE MONDAY...LIKELY
PULLING A COLD FRONT OFF THE COAST BY TUESDAY MORNING. EXPECT A
SURGE IN SOUTHERLY WINDS AHEAD OF THE SYSTEM EARLY TUESDAY...WITH
THE POTENTIAL FOR ONLY MARGINAL ADVISORY-LEVEL WINDS ACROSS
PORTIONS OF THE WATERS. A MORE SOLID SURGE INTO SMALL CRAFT
ADVISORY CONDITIONS WILL OCCUR WITHIN COLD ADVECTION AND WESTERLY
FLOW BEHIND A SECONDARY COLD FRONT MOVING THROUGH THE AREA EARLY
WEDNESDAY.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EST SUNDAY FOR AMZ330-352-354.
SMALL CRAFT ADVISORY UNTIL 8 AM EST SUNDAY FOR AMZ350.
SMALL CRAFT ADVISORY UNTIL 1 PM EST SUNDAY FOR AMZ374.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
544 AM EST FRI JAN 10 2014
.SYNOPSIS...
HIGH PRESSURE CENTERED OFF THE NORTHEAST COAST WILL CIRCULATE
MOIST AIR FROM THE ATLANTIC INTO THE FORECAST AREA AHEAD OF A
COLD FRONT APPROACHING FROM THE WEST. THE FRONT WILL MOVE
THROUGH THE AREA SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MOISTURE ASSOCIATED WITH THE ONSHORE FLOW AND ISENTROPIC LIFT WILL
BRING CLOUDINESS AND RAIN TODAY. THE 07Z HRRR MAINTAINS RAIN OVER
MUCH OF THE AREA THROUGH TODAY. THE NAM AND TO SOME DEGREE THE GFS
INDICATE DIMINISHING MOISTURE DURING THE AFTERNOON. THE NAM AND
GFS MOS DISPLAY LOWER POPS THIS AFTERNOON COMPARED TO THE MORNING.
THE NAM SHOWS AN H7 SHORTWAVE TROUGH LIFTING NORTH OF THE AREA
AFTER 18Z WITH MOISTURE BECOMING MORE SHALLOW BEHIND THIS FEATURE.
FORECASTED LOWER POPS DURING THE AFTERNOON...BUT NOT AS LOW AS THE
NAM AND GFS MOS BECAUSE OF THE HRRR. CONFIDENCE IS LOW WITH THE
TEMPERATURE FORECAST. WE USED THE COOLER TEMPERATURE GUIDANCE
BECAUSE OF THE WEDGE PATTERN BUT MOISTURE BECOMING MORE SHALLOW
BEHIND THE SHORTWAVE TROUGH MAY LEAD TO BREAKS IN THE CLOUDINESS
AND WARMER TEMPERATURES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
THE NAM AND GFS SHOW MOISTURE SOMEWHAT SHALLOW WITH LITTLE
ISENTROPIC LIFT TONIGHT. USED THE GUIDANCE CONSENSUS AND
FORECASTED CHANCE POPS. HIGH LOW-LEVEL MOISTURE AND DIURNAL
COOLING PLUS CONVERGENCE NEAR THE WEDGE/WARM FRONT SHOULD HELP
SUPPORT FOG TONIGHT. DENSE FOG MAY OCCUR. THE NAM AND GFS MOS
PLUS SREF GUIDANCE INDICATE FOG.
THE MOISTURE INCREASE ASSOCIATED WITH THE STRONG H85 JET AND LIFT
WITH THE RIGHT ENTRANCE REGION OF THE H25 JET PLUS CONVERGENCE
ALONG THE COLD FRONT SUPPORT CATEGORICAL POPS SATURDAY. THE
NAM...GFS...AND SREF MEAN DISPLAY RAIN AMOUNTS AROUND 0.6 OF AN
INCH. THERE MAY BE ENOUGH INSTABILITY FOR THUNDERSTORMS. THE NAM
INDICATES SURFACE-BASED LI/S -2 TO -3. THE INSTABILITY IS
QUESTIONABLE BECAUSE IT SHOULD BE LIMITED BY CLOUDINESS AND FOG.
HOWEVER...IF SURFACE-BASED INSTABILITY DOES DEVELOP THEN DAMAGING
WIND MAY OCCUR WITH ANY THUNDERSTORMS BECAUSE OF STRONG SHEAR. THE
NAM AND GFS HAVE H85 WINDS OF 50 TO 60 KNOTS.
DRYING WILL OCCUR BEHIND THE FRONT SATURDAY NIGHT.
WE USED THE GUIDANCE CONSENSUS FOR THE TEMPERATURE FORECAST
THROUGH THE PERIOD EXCEPT THE COOLER GUIDANCE MAY BE BETTER
SATURDAY BECAUSE OF CLOUDINESS AND SHOWERS.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
THE GFS AND ECMWF SHOW DRY RIDGING DOMINATING SUNDAY INTO MONDAY.
THE MODELS DISPLAY MOISTURE ASSOCIATED WITH A COLD FRONT MONDAY
NIGHT AND TUESDAY MORNING. THE ECMWF SHOWS A STRONGER SYSTEM AND
ITS MOS HAS LIKELY POPS. WE KEPT CHANCE POPS FOR NOW AS GIVEN BY
THE GFS AND EKD MOS PLUS GFS ENSEMBLE MEAN. EXPECT A REINFORCING
COLD FRONT WITH LIMITED MOISTURE WEDNESDAY. ABOVE NORMAL
TEMPERATURES SHOULD OCCUR SUNDAY THROUGH TUESDAY...WITH NEAR OR
BELOW NORMAL READINGS BEHIND THE FRONT BY THURSDAY.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
HIGH PRESSURE CONTINUES TO MOVE AWAY FROM THE REGION AS LOW
PRESSURE DEVELOPS OVER THE CENTRAL PLAINS. SOUTHEASTERLY LOW LEVEL
WINDS CONTINUE TO PUSH MOISTURE INTO THE AREA WITH WSR-88D RETURNS
INDICATING LIGHT RAIN ACROSS THE AREA. RAIN WILL CONTINUE
INCREASING IN COVERAGE OVERNIGHT INTO FRIDAY MORNING AS ISENTROPIC
ASCENT PERSISTS. CIGS WILL BE THE MAIN CONCERN THROUGH THE PERIOD
WITH CIGS LOWERING TO AROUND 800 FEET BY 09Z...WITH FURTHER
LOWERING TO AROUND 500 FEET FROM 11/01Z THROUGH THE END OF THE TAF
PERIOD. EXPECT RAIN TO REMAIN LIGHT THROUGH 15-17Z WHEN THE BEST
MOISTURE FLUX SHIFTS NORTHWARD AND RAIN DIMINISHES. WINDS THROUGH
THE PERIOD WILL BE NORTHEASTERLY AT 6 KNOTS OR LESS.
EXTENDED AVIATION OUTLOOK...INCREASING CONFIDENCE IN CIG
RESTRICTIONS SATURDAY THROUGH SATURDAY NIGHT...WITH INCREASING
CHANCES OF SHOWERS SATURDAY MORNING AS A COLD FRONT APPROACHES.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
414 PM CST FRI JAN 10 2014
.DISCUSSION...
326 PM CST
THE RAPIDLY EVOLVING NEXT 18 TO 24 HOURS APPEAR TO BE THE MOST
CHALLENGING PORTION OF THE FORECAST FOR THE WEEKEND INTO NEXT WEEK.
ISOLATED THUNDERSTORMS HAVE MOVED INTO THE AREA THIS AFTERNOON AND
SUBFREEZING TEMPERATURES HAVE FOR THE MOST PART MOVED OUT...AT LEAST
FOR THE TIME BEING. THE PRIMARY FORECAST CONCERNS IN THE NEAR TERM
INCLUDE DENSE FOG AND THE POSSIBLE NEED FOR AN ADVISORY LATER
TONIGHT...THUNDERSTORM TRENDS AND COVERAGE...AND THE FLOOD POTENTIAL
GIVEN THE EXPECTED RAINFALL AND WARMING TEMPERATURES.
AS MENTIONED IN THE MORNING AFD UPDATE...THE FIRST QUESTION WOULD BE
WHETHER DENSE FOG DEVELOPS IN THE SATURATED SURFACE LAYER MOVING IN
OVER THE SNOWPACK WITH INCREASING DEWPOINTS. OBSERVATIONS JUST
UPSTREAM OF THE AREA ARE SHOWING VSBYS AT WORST AROUND 1 MILE AND
GENERALLY QUITE A BIT HIGHER...BUT FARTHER WEST AND SOUTHWEST TOWARD
THE APPROACHING LOW CENTER THEY ARE MORE COMMONLY AROUND 1/4 TO 1/2
MILE. STILL AM NOT ANTICIPATING THE NEED FOR FOG HEADLINES IN THE
IMMEDIATE TERM. WINDS IN THE TEENS AND MODERATE RAIN ACTUALLY SEEM
TO BE HELPING THINGS AS WELL...BUT THE EVENING SHIFT WILL NEED TO
REEVALUATE IN CASE CONDITIONS DETERIORATE AND A HEADLINE BECOMES
NECESSARY LATE THIS EVENING OR OVERNIGHT.
THE AREA OF THUNDERSTORMS SEEN EARLIER TODAY AROUND QUINCY HAS NOW
MOVED INTO THE LOCAL AREA AS ANTICIPATED...IN CONJUNCTION WITH THE
INCREASING LOW LEVEL MOISTURE FLUX DEPICTED IN THE RAP MODEL EAST OF
THE APPROACHING LOW PRESSURE CENTER. AM NOT SEEING ANYTHING TO
SUGGEST THIS ACTIVITY WILL BECOME WIDESPREAD THIS EVENING AS THE LOW
LIFTS NORTHEAST...BUT WILL MAINTAIN A FIRST PERIOD MENTION OF
ISOLATED TO SCATTERED THUNDERSTORMS MAINLY FOR THE SOUTHERN HALF OF
THE AREA.
AS FOR FLOODING POTENTIAL...HAVE BEEN CONSIDERING A FLOOD ADVISORY
FOR URBAN AREAS WHERE RAIN MAY BE PONDING DUE TO DRAINS CLOGGED WITH
ICE AND SNOW. AM NOT PLANNING ON ANY AREAL FLOOD WARNING HEADLINES
AT THIS TIME GIVEN SO MANY VARIABLES...INCLUDING LOCATION OF HEAVIER
RAIN AMOUNTS...DEGREE TO WHICH THE SNOWPACK WOULD SPONGE UP THE
RAIN...EVOLUTION OF DEWPOINT TEMPERATURES...AND THE BEHAVIOR OF ICE
ON THE RIVERS AND STREAMS. THE BEST POTENTIAL FOR MAINSTEM FLOODING
STILL APPEARS TO BE LIMITED TO THE KANKAKEE WHERE A FLOOD WARNING
WAS ISSUED EARLIER FOR ANTICIPATED MINOR FLOODING. THE OTHER RIVERS
HAVE A LITTLE MORE ROOM TO HANDLE THE RUNOFF.
FOR TONIGHT INTO TOMORROW MORNING...MAY TWEAK THE TIMING A BIT BUT
AM NOT PLANNING ANY BIG CHANGES TO PRECIPITATION TRENDS. STILL
EXPECTING MAINLY RAIN OVERNIGHT...EVOLVING TO DRIZZLE AND MAYBE A
PERIOD OF LIGHT SNOW AS COLD AIR MOVES IN TOWARD MORNING.
THE REMAINDER OF THE WEEKEND LOOKS DRY AND RELATIVELY MILD WITH
SOUTHERLY WINDS AND CLEARING SKIES SUNDAY. NEXT WEEK BRINGS A
RETURN TO SOMEWHAT MORE SEASONABLE...THOUGH STILL BELOW
NORMAL...TEMPERATURES AND MULTIPLE PERIODS OF LIGHT SNOW POTENTIAL
CORRESPONDING TO COLD FRONTAL PASSAGES. THE PRIMARY SURFACE CYCLONE
TRACK APPEARS TO STAY NORTH OF THE LOCAL AREA. THE MOST PRONOUNCED
COLD AIR INTRUSION LOOKS POISED TO ARRIVE LATE IN THE
WEEK...POTENTIALLY KEEPING HIGHS ONLY IN THE TEENS NEXT FRIDAY.
LENNING
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* LOW CEILINGS CONTINUING THROUGH THE REST OF THE DAY...IMPROVING
BEHIND COLD FRONT EARLY TOMORROW.
* VSBY GENERALLY 1-3SM...BUT POSSIBLY LESS THAN A QUARTER MILE IF
DENSE FOG WERE TO DEVELOP.
MDB
//DISCUSSION...UPDATED 22Z...
LIGHT TO MODERATE AND OCCASIONALLY HEAVY RAIN CONTINUES TO MOVE
ACROSS THE TERMINALS AND WILL CONTINUE TO DO SO INTO THE EARLY
EVENING. OBSERVATIONS SHOW A RANGE OF VISIBILITY GENERALLY IN THE
1-3SM RANGE WITH SOME SPOTS SLIGHTLY HIGHER. CIGS HAVE VARIED TO
MVFR AT TIMES IN SPOTS LIKELY DUE TO SOME EARLIER
CONVECTIVE/THUNDER ELEMENTS...BUT A MORE UNIFORM IFR/LIFR LAYER IS
EXPECTED TO PERSIST. STEADIER RAIN LOOKS TO BEGIN TO EXIT THE AREA
FROM THE WEST EARLY THIS EVENING. STILL MONITORING FOR DENSE FOG
POTENTIAL AS THE RAIN ENDS BUT WILL LEAVE VSBY AT 1SM FOR NOW THIS
EVENING/EARLY TONIGHT WITH THE WORST VISIBILITY POSSIBLY PASSING
TO THE WEST.
MDB
FROM 18Z...
A WASHED OUT WARM FRONT IS LIFTING INTO ILLINOIS EARLY THIS
AFTERNOON...WITH A BROAD DEWPOINT GRADIENT SPREADING NORTHWARD
ACROSS THE STATE. NORTH OF THE FRONT...CIGS ARE GENERALLY BETWEEN
002 AND 005 WHILE VSBY IS MORE VARIABLE...BUT NUMEROUS 1-3SM REPORTS
ARE NOTED ACROSS FAR NORTHERN ILLINOIS DUE TO FOG/MIST. AS LOW
PRESSURE TRACKS FROM EASTERN NEBRASKA THIS AFTERNOON INTO SOUTHERN
WISCONSIN LATER THIS EVENING...EXPECT NORTHWARD MOISTURE TRANSPORT TO
CONTINUE WITH DEWPOINTS RISING INTO THE MID OR UPPER 30S OVER THE
SNOWPACK. THE IMMEDIATE CONCERN HERE IS FOR THE POTENTIAL OF DENSE
FOG DEVELOPING...WITH MET GUIDANCE INDICATING VSBY TANKING THIS
AFTERNOON. FEEL GUIDANCE MAY BE HITTING THIS TOO HARD THOUGH GIVEN
THE BROAD TD GRADIENT...AND WILL LEAN TOWARDS A MORE OPTIMISTIC VSBY
FORECAST...ADMITTEDLY WITH LOW CONFIDENCE CONSIDERING THE MORE
WIDESPREAD 1/4 TO 1/2 SM VSBY IMMEDIATELY AHEAD OF THE LOW.
SHOWERS WILL OVERSPREAD THE AREA THIS AFTERNOON AS A POTENT UPPER
WAVE LIFTS ACROSS THE REGION. MID LEVEL LAPSE RATES MAY BE
SUFFICIENTLY STEEP ENOUGH TO SUPPORT EMBEDDED THUNDERSTORMS AS FAR
NORTH AS THE CHICAGO TERMINALS...HOWEVER FELL BEST CHANCES FOR FOR
THUNDER WILL STAY SOUTH OF THE I-80 CORRIDOR. RAIN IS EXPECTED TO BE
MODERATE WITH BRIEFLY HEAVY SHOWERS POSSIBLE. DEEPER MOISTURE WILL
PUSH OUT OF THE AREA MID TO LATE THIS EVENING WITH LINGERING DRIZZLE
POSSIBLE INTO THE EARLY OVERNIGHT HOURS. FEEL THAT ONCE THE RAIN
STOPS THIS EVENING...THIS WILL BE THE PERIOD THAT MAY HAVE TO BE
MONITORED MOST CLOSELY FOR FOG DEVELOPING. DEWPOINTS SHOULD BE
CLIMBING INTO THE 35-37 RANGE BY THIS POINT WHICH ASSUMING THERE IS
STILL SOME SNOW ON THE GROUND WOULD BE FAVORABLE FOR FOG TO INCREASE
IN THICKNESS. UNFORTUNATELY...MET/MAV GUIDANCE SHOWS THE
OPPOSITE...WITH IMPROVING VSBY TRENDS AFTER THE RAIN DEPARTS
OVERNIGHT...ONCE AGAIN RESULTING IN VERY LOW CONFIDENCE IN VSBY
FCST. WILL STICK WITH GOING VSBY TRENDS THIS PERIOD UNTIL HAVE
HIGHER CONFIDENCE IN A SOLUTION.
A COLD FRONT WILL SWEEP ACROSS THE AREA EARLY SATURDAY. WHILE
NOTABLE DRYING OCCURS ALOFT...APPEARS WE MAY STICK FOR SEVERAL HOURS
WITH SOME POST FRONTAL STRATUS...AT LEAST UNTIL SATURDAY AFTERNOON
WHEN IT MAY FINALLY SCATTER OUT. VSBY SHOULD SHARPLY IMPROVE BEHIND
THE FRONT THOUGH WITH WINDS TURNING WESTERLY AND BECOMING
INCREASINGLY GUSTY.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* LOW CONFIDENCE IN VSBY TRENDS THROUGH TONIGHT.
* HIGH CONFIDENCE IN IFR OR LOWER CIGS THROUGH THE OVERNIGHT HOURS.
* HIGH CONFIDENCE IN RAIN TIMING.
* MEDIUM-HIGH CONFIDENCE IN WIND DIRECTION...MEDIUM CONFIDENCE IN
WIND SPEED.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT...VFR PROBABLE.
SUNDAY...STRONG SOUTH WINDS...LLWS POSSIBLE AFTERNOON/EARLY
EVENING. VFR PROBABLE.
MONDAY...VFR.
TUESDAY...CHANCE OF SNOW/IFR.
WEDNESDAY AND THURSDAY...VFR PROBABLE.
IZZI
&&
.MARINE...
209 PM CST
LARGE DOME OF HIGH PRESSURE OVER THE EASTERN SEABOARD HAS DRIFTED
EAST...AND STRETCHES FROM CENTRAL QUEBEC SOUTH THROUGH THE CAROLINA
COAST. MEANWHILE ACROSS THE CENTRAL PLAINS A SERIES OF LOW PRESSURES
EXISTED...WITH ONE ACROSS THE NORTHERN PLAINS AND THE SECOND ACROSS
THE CENTRAL PLAINS. THESE TWO AREAS OF LOW PRESSURES WILL CONVERGE
UPON LAKE MICHIGAN...CONSOLIDATING INTO A SLIGHTLY STRONGER LOW
PRESSURE OVER THE NORTHERN PORTION OF LAKE MICHIGAN EARLY SATURDAY
MORNING. WINDS FOR MUCH OF THE LAKE WILL REMAIN SOUTHERLY...WITH THE
FAR NORTHERN PORTIONS NEAR THE STRAITS OF MACKINAW BEING SLIGHTLY
SOUTHEAST/EAST. THEN WITH THE LOW PASSAGE EXPECTED TO OCCUR SATURDAY
MORNING WITH A TRAILING FRONTAL BOUNDARY SLIDING EAST ACROSS THE
LAKE...THE GRADIENT IS EXPECTED TO TIGHTEN. FOR THE CENTRAL/SOUTHERN
PORTIONS WINDS WILL INCREASE TO NEAR 30 KT BY MIDDAY/EARLY AFTN SAT.
THEN AS THE FRONTAL BOUNDARY CONTINUES TO PRESS EAST...WINDS WILL
TURN MORE TO THE WEST. FOR THE NORTHERN HALF OF THE LAKE WINDS FOR A
PERIOD WILL BECOME NORTHWEST...BEFORE RELAXING TO THE WEST SAT LATE
AFTN.
HIGH PRESSURE ACROSS THE SOUTHERN PLAINS SAT AFTN WILL CONTINUE TO
SLIDE EAST...STRETCHING AN INFLUENCE NORTH TO LAKE MICHIGAN SATURDAY
NIGHT/EARLY SUN. THIS COUPLED WITH YET ANOTHER LOW PRESSURE SYSTEM
BEGINNING TO PUSH INTO CENTRAL CANADA...WILL ALLOW THE GRADIENT TO
TIGHTEN. WINDS SHOULD REMAIN BREEZY SUN AFTN/EVE. THE GRADIENT HAS
BECOME SLIGHTLY TIGHTER...ALONG WITH THE LOW PRESSURE BECOME DEEPER
TO 28.9 INCHES JUST NORTH OF LAKE SUPERIOR SUN EVE. THIS WILL LIKELY
CREATE A PERIOD OF GALES FOR THE LAKE DURING THE SUN AFTN/EVE
TIMEFRAME. THE GRADIENT THEN BEGINS TO SLACKEN OFF FOR THE MIDDLE OF
NEXT WEEK...WITH JUST A COUPLE WEAK WAVES TRAVERSING THE WESTERN
GREAT LAKES REGION. IN THE LONGER RANGE PERIODS FORECAST GUIDANCE IS
BEGINNING TO INDICATE A STRENGTHENING LOW PRESSURE OVER THE OHIO
VALLEY TUE NIGHT...WHICH COULD RESULT IN A TIGHTENING GRADIENT FOR
LAKE MICHIGAN WED AND BREEZY CONDITIONS RETURNING.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
326 PM CST FRI JAN 10 2014
.DISCUSSION...
326 PM CST
THE RAPIDLY EVOLVING NEXT 18 TO 24 HOURS APPEAR TO BE THE MOST
CHALLENGING PORTION OF THE FORECAST FOR THE WEEKEND INTO NEXT WEEK.
ISOLATED THUNDERSTORMS HAVE MOVED INTO THE AREA THIS AFTERNOON AND
SUBFREEZING TEMPERATURES HAVE FOR THE MOST PART MOVED OUT...AT LEAST
FOR THE TIME BEING. THE PRIMARY FORECAST CONCERNS IN THE NEAR TERM
INCLUDE DENSE FOG AND THE POSSIBLE NEED FOR AN ADVISORY LATER
TONIGHT...THUNDERSTORM TRENDS AND COVERAGE...AND THE FLOOD POTENTIAL
GIVEN THE EXPECTED RAINFALL AND WARMING TEMPERATURES.
AS MENTIONED IN THE MORNING AFD UPDATE...THE FIRST QUESTION WOULD BE
WHETHER DENSE FOG DEVELOPS IN THE SATURATED SURFACE LAYER MOVING IN
OVER THE SNOWPACK WITH INCREASING DEWPOINTS. OBSERVATIONS JUST
UPSTREAM OF THE AREA ARE SHOWING VSBYS AT WORST AROUND 1 MILE AND
GENERALLY QUITE A BIT HIGHER...BUT FARTHER WEST AND SOUTHWEST TOWARD
THE APPROACHING LOW CENTER THEY ARE MORE COMMONLY AROUND 1/4 TO 1/2
MILE. STILL AM NOT ANTICIPATING THE NEED FOR FOG HEADLINES IN THE
IMMEDIATE TERM. WINDS IN THE TEENS AND MODERATE RAIN ACTUALLY SEEM
TO BE HELPING THINGS AS WELL...BUT THE EVENING SHIFT WILL NEED TO
REEVALUATE IN CASE CONDITIONS DETERIORATE AND A HEADLINE BECOMES
NECESSARY LATE THIS EVENING OR OVERNIGHT.
THE AREA OF THUNDERSTORMS SEEN EARLIER TODAY AROUND QUINCY HAS NOW
MOVED INTO THE LOCAL AREA AS ANTICIPATED...IN CONJUNCTION WITH THE
INCREASING LOW LEVEL MOISTURE FLUX DEPICTED IN THE RAP MODEL EAST OF
THE APPROACHING LOW PRESSURE CENTER. AM NOT SEEING ANYTHING TO
SUGGEST THIS ACTIVITY WILL BECOME WIDESPREAD THIS EVENING AS THE LOW
LIFTS NORTHEAST...BUT WILL MAINTAIN A FIRST PERIOD MENTION OF
ISOLATED TO SCATTERED THUNDERSTORMS MAINLY FOR THE SOUTHERN HALF OF
THE AREA.
AS FOR FLOODING POTENTIAL...HAVE BEEN CONSIDERING A FLOOD ADVISORY
FOR URBAN AREAS WHERE RAIN MAY BE PONDING DUE TO DRAINS CLOGGED WITH
ICE AND SNOW. AM NOT PLANNING ON ANY AREAL FLOOD WARNING HEADLINES
AT THIS TIME GIVEN SO MANY VARIABLES...INCLUDING LOCATION OF HEAVIER
RAIN AMOUNTS...DEGREE TO WHICH THE SNOWPACK WOULD SPONGE UP THE
RAIN...EVOLUTION OF DEWPOINT TEMPERATURES...AND THE BEHAVIOR OF ICE
ON THE RIVERS AND STREAMS. THE BEST POTENTIAL FOR MAINSTEM FLOODING
STILL APPEARS TO BE LIMITED TO THE KANKAKEE WHERE A FLOOD WARNING
WAS ISSUED EARLIER FOR ANTICIPATED MINOR FLOODING. THE OTHER RIVERS
HAVE A LITTLE MORE ROOM TO HANDLE THE RUNOFF.
FOR TONIGHT INTO TOMORROW MORNING...MAY TWEAK THE TIMING A BIT BUT
AM NOT PLANNING ANY BIG CHANGES TO PRECIPITATION TRENDS. STILL
EXPECTING MAINLY RAIN OVERNIGHT...EVOLVING TO DRIZZLE AND MAYBE A
PERIOD OF LIGHT SNOW AS COLD AIR MOVES IN TOWARD MORNING.
THE REMAINDER OF THE WEEKEND LOOKS DRY AND RELATIVELY MILD WITH
SOUTHERLY WINDS AND CLEARING SKIES SUNDAY. NEXT WEEK BRINGS A
RETURN TO SOMEWHAT MORE SEASONABLE...THOUGH STILL BELOW
NORMAL...TEMPERATURES AND MULTIPLE PERIODS OF LIGHT SNOW POTENTIAL
CORRESPONDING TO COLD FRONTAL PASSAGES. THE PRIMARY SURFACE CYCLONE
TRACK APPEARS TO STAY NORTH OF THE LOCAL AREA. THE MOST PRONOUNCED
COLD AIR INTRUSION LOOKS POISED TO ARRIVE LATE IN THE
WEEK...POTENTIALLY KEEPING HIGHS ONLY IN THE TEENS NEXT FRIDAY.
LENNING
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* LOW CEILINGS CONTINUING THROUGH THE REST OF THE DAY...IMPROVING
BEHIND COLD FRONT EARLY TOMORROW.
* VSBY GENERALLY 1-3SM...BUT POSSIBLY LESS THAN A QUARTER MILE IF
DENSE FOG WERE TO DEVELOP.
BMD
//DISCUSSION...UPDATED 18Z...
A WASHED OUT WARM FRONT IS LIFTING INTO ILLINOIS EARLY THIS
AFTERNOON...WITH A BROAD DEWPOINT GRADIENT SPREADING NORTHWARD
ACROSS THE STATE. NORTH OF THE FRONT...CIGS ARE GENERALLY BETWEEN
002 AND 005 WHILE VSBY IS MORE VARIABLE...BUT NUMEROUS 1-3SM REPORTS
ARE NOTED ACROSS FAR NORTHERN ILLINOIS DUE TO FOG/MIST. AS LOW
PRESSURE TRACKS FROM EASTERN NEBRASKA THIS AFTERNOON INTO SOUTHERN
WISCONSIN LATER THIS EVENING...EXPECT NORTHWARD MOISTURE TRANSPORT TO
CONTINUE WITH DEWPOINTS RISING INTO THE MID OR UPPER 30S OVER THE
SNOWPACK. THE IMMEDIATE CONCERN HERE IS FOR THE POTENTIAL OF DENSE
FOG DEVELOPING...WITH MET GUIDANCE INDICATING VSBY TANKING THIS
AFTERNOON. FEEL GUIDANCE MAY BE HITTING THIS TOO HARD THOUGH GIVEN
THE BROAD TD GRADIENT...AND WILL LEAN TOWARDS A MORE OPTIMISTIC VSBY
FORECAST...ADMITTEDLY WITH LOW CONFIDENCE CONSIDERING THE MORE
WIDESPREAD 1/4 TO 1/2 SM VSBY IMMEDIATELY AHEAD OF THE LOW.
SHOWERS WILL OVERSPREAD THE AREA THIS AFTERNOON AS A POTENT UPPER
WAVE LIFTS ACROSS THE REGION. MID LEVEL LAPSE RATES MAY BE
SUFFICIENTLY STEEP ENOUGH TO SUPPORT EMBEDDED THUNDERSTORMS AS FAR
NORTH AS THE CHICAGO TERMINALS...HOWEVER FELL BEST CHANCES FOR FOR
THUNDER WILL STAY SOUTH OF THE I-80 CORRIDOR. RAIN IS EXPECTED TO BE
MODERATE WITH BRIEFLY HEAVY SHOWERS POSSIBLE. DEEPER MOISTURE WILL
PUSH OUT OF THE AREA MID TO LATE THIS EVENING WITH LINGERING DRIZZLE
POSSIBLE INTO THE EARLY OVERNIGHT HOURS. FEEL THAT ONCE THE RAIN
STOPS THIS EVENING...THIS WILL BE THE PERIOD THAT MAY HAVE TO BE
MONITORED MOST CLOSELY FOR FOG DEVELOPING. DEWPOINTS SHOULD BE
CLIMBING INTO THE 35-37 RANGE BY THIS POINT WHICH ASSUMING THERE IS
STILL SOME SNOW ON THE GROUND WOULD BE FAVORABLE FOR FOG TO INCREASE
IN THICKNESS. UNFORTUNATELY...MET/MAV GUIDANCE SHOWS THE
OPPOSITE...WITH IMPROVING VSBY TRENDS AFTER THE RAIN DEPARTS
OVERNIGHT...ONCE AGAIN RESULTING IN VERY LOW CONFIDENCE IN VSBY
FCST. WILL STICK WITH GOING VSBY TRENDS THIS PERIOD UNTIL HAVE
HIGHER CONFIDENCE IN A SOLUTION.
A COLD FRONT WILL SWEEP ACROSS THE AREA EARLY SATURDAY. WHILE
NOTABLE DRYING OCCURS ALOFT...APPEARS WE MAY STICK FOR SEVERAL HOURS
WITH SOME POST FRONTAL STRATUS...AT LEAST UNTIL SATURDAY AFTERNOON
WHEN IT MAY FINALLY SCATTER OUT. VSBY SHOULD SHARPLY IMPROVE BEHIND
THE FRONT THOUGH WITH WINDS TURNING WESTERLY AND BECOMING
INCREASINGLY GUSTY.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* VERY LOW CONFIDENCE IN VSBY TRENDS TODAY AND TONIGHT.
* HIGH CONFIDENCE IN IFR OR LOWER CIGS THROUGH THE OVERNIGHT HOURS.
* HIGH CONFIDENCE IN RAIN TIMING.
* MEDIUM-HIGH CONFIDENCE IN WIND DIRECTION...MEDIUM CONFIDENCE IN
WIND SPEED.
BMD
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT...VFR PROBABLE.
SUNDAY...STRONG SOUTH WINDS...LLWS POSSIBLE AFTERNOON/EARLY
EVENING. VFR PROBABLE.
MONDAY...VFR.
TUESDAY...CHANCE OF SNOW/IFR.
WEDNESDAY AND THURSDAY...VFR PROBABLE.
IZZI
&&
.MARINE...
209 PM CST
LARGE DOME OF HIGH PRESSURE OVER THE EASTERN SEABOARD HAS DRIFTED
EAST...AND STRETCHES FROM CENTRAL QUEBEC SOUTH THROUGH THE CAROLINA
COAST. MEANWHILE ACROSS THE CENTRAL PLAINS A SERIES OF LOW PRESSURES
EXISTED...WITH ONE ACROSS THE NORTHERN PLAINS AND THE SECOND ACROSS
THE CENTRAL PLAINS. THESE TWO AREAS OF LOW PRESSURES WILL CONVERGE
UPON LAKE MICHIGAN...CONSOLIDATING INTO A SLIGHTLY STRONGER LOW
PRESSURE OVER THE NORTHERN PORTION OF LAKE MICHIGAN EARLY SATURDAY
MORNING. WINDS FOR MUCH OF THE LAKE WILL REMAIN SOUTHERLY...WITH THE
FAR NORTHERN PORTIONS NEAR THE STRAITS OF MACKINAW BEING SLIGHTLY
SOUTHEAST/EAST. THEN WITH THE LOW PASSAGE EXPECTED TO OCCUR SATURDAY
MORNING WITH A TRAILING FRONTAL BOUNDARY SLIDING EAST ACROSS THE
LAKE...THE GRADIENT IS EXPECTED TO TIGHTEN. FOR THE CENTRAL/SOUTHERN
PORTIONS WINDS WILL INCREASE TO NEAR 30 KT BY MIDDAY/EARLY AFTN SAT.
THEN AS THE FRONTAL BOUNDARY CONTINUES TO PRESS EAST...WINDS WILL
TURN MORE TO THE WEST. FOR THE NORTHERN HALF OF THE LAKE WINDS FOR A
PERIOD WILL BECOME NORTHWEST...BEFORE RELAXING TO THE WEST SAT LATE
AFTN.
HIGH PRESSURE ACROSS THE SOUTHERN PLAINS SAT AFTN WILL CONTINUE TO
SLIDE EAST...STRETCHING AN INFLUENCE NORTH TO LAKE MICHIGAN SATURDAY
NIGHT/EARLY SUN. THIS COUPLED WITH YET ANOTHER LOW PRESSURE SYSTEM
BEGINNING TO PUSH INTO CENTRAL CANADA...WILL ALLOW THE GRADIENT TO
TIGHTEN. WINDS SHOULD REMAIN BREEZY SUN AFTN/EVE. THE GRADIENT HAS
BECOME SLIGHTLY TIGHTER...ALONG WITH THE LOW PRESSURE BECOME DEEPER
TO 28.9 INCHES JUST NORTH OF LAKE SUPERIOR SUN EVE. THIS WILL LIKELY
CREATE A PERIOD OF GALES FOR THE LAKE DURING THE SUN AFTN/EVE
TIMEFRAME. THE GRADIENT THEN BEGINS TO SLACKEN OFF FOR THE MIDDLE OF
NEXT WEEK...WITH JUST A COUPLE WEAK WAVES TRAVERSING THE WESTERN
GREAT LAKES REGION. IN THE LONGER RANGE PERIODS FORECAST GUIDANCE IS
BEGINNING TO INDICATE A STRENGTHENING LOW PRESSURE OVER THE OHIO
VALLEY TUE NIGHT...WHICH COULD RESULT IN A TIGHTENING GRADIENT FOR
LAKE MICHIGAN WED AND BREEZY CONDITIONS RETURNING.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
209 PM CST FRI JAN 10 2014
.DISCUSSION...
1114 AM CST
HAVE SPENT THE MORNING EXAMINING THE POTENTIAL FOR DENSE FOG AND
THE POSSIBLE NEED FOR AN ADVISORY LATER TODAY...THE APPROACHING
THUNDERSTORMS IN WEST CENTRAL ILLINOIS...AND THE FLOOD POTENTIAL
GIVEN THE EXPECTED RAINFALL AND WARMING TEMPERATURES.
FOR THE NEAR TERM WE ELECTED TO CANCEL THE FREEZING FOG ADVISORY A
LITTLE EARLY AS TEMPERATURES IN MOST LOCATIONS HAVE RISEN ABOVE OR
VERY NEAR FREEZING. THE NEXT QUESTION WOULD BE WHETHER DENSE FOG
DEVELOPS IN THE SATURATED SURFACE LAYER MOVING IN OVER THE
SNOWPACK WITH INCREASING DEWPOINTS. OBSERVATIONS JUST UPSTREAM OF
THE AREA ARE SHOWING VSBYS AT WORST AROUND 1 MILE...BUT FARTHER
UPSTREAM TOWARD THE APPROACHING LOW CENTER THEY ARE MORE COMMONLY
AROUND 1/4 TO 1/2 MILE. SO FOR THE AFTERNOON AM NOT ANTICIPATING
THE NEED FOR FOG HEADLINES...BUT WILL REEVALUATE LATER TODAY IN
CASE SOMETHING MAY BE NEEDED THIS EVENING OR OVERNIGHT.
THE AREA OF THUNDERSTORMS AROUND QUINCY AND SOUTHWEST TOWARD
JOPLIN MISSOURI IS WELL CORRELATED WITH AN AREA OF ENHANCED LOW
LEVEL MOISTURE FLUX SHOWN IN THE RAP MODEL EAST OF THE
APPROACHING LOW PRESSURE CENTER. AS THE AFTERNOON EVOLVES AND THE
LOW LIFTS NORTHEAST...THE RAP MODEL INCREASES THE MOISTURE FLUX
OVER CENTRAL AND NORTHERN ILLINOIS. AREAS OF STEEPER LAPSE RATES
ARE ALSO SEEN IN NAM/GFS SOUNDINGS FOR THE AFTERNOON AND EVENING
TIMEFRAME. WILL UPDATE FCST GRIDS TO INTRODUCE A SLIGHT CHANCE OF
TSTMS MAINLY FOR THE SOUTHERN HALF OF THE AREA.
AS FOR FLOODING POTENTIAL...AM NOT PLANNING ON ANY FLOOD WATCH
HEADLINES AT THIS TIME GIVEN SO MANY VARIABLES...INCLUDING
LOCATION OF HEAVIER RAIN AMOUNTS...DEGREE TO WHICH THE SNOWPACK
WOULD SPONGE UP THE RAIN...EVOLUTION OF DEWPOINT
TEMPERATURES...AND THE BEHAVIOR OF ICE ON THE RIVERS AND STREAMS.
THE BEST POTENTIAL FOR MAINSTEM FLOODING APPEARS TO BE ALONG THE
KANKAKEE WHERE A FLOOD WARNING HAS BEEN ISSUED FOR ANTICIPATED MINOR
FLOODING. THIS RIVER ALREADY HAD QUITE A BIT OF WATER IN IT...BUT
THE OTHERS HAVE A LITTLE MORE ROOM TO HANDLE THE RUNOFF.
LENNING
//PREV DISCUSSION...
338 AM CST
SHORT TERM...TODAY THROUGH SUNDAY NIGHT
TODAY/TONIGHT...
MULTIPLE CONCERNS IN THE NEAR TERM TODAY...INCLUDING DENSE
FOG...FREEZING DRIZZLE/RAIN AND THEN RAIN AND MELTING SNOW LATER
TODAY INTO THIS EVENING.
GRADUAL INCREASE IN SURFACE MOISTURE OVER DEEP SNOW PACK HAS
RESULTED IN FOG DEVELOPMENT EARLY THIS MORNING...WITH MULTIPLE
LOCATIONS AOB 1/2 MILE. FOG HAS BEEN MOST DENSE ALONG/WEST OF A LINE
FROM UGN TO VYS. WILL LIKELY NEED A DENSE FOG ADVISORY ADVISORY OR
FREEZING FOG ADVISORY FOR MOST IF NOT ALL IF THIS AREA FOR PART OF
TODAY UNTIL TEMPERATURES WARM AND STEADIER PRECIP ARRIVES
LATER...WITH CONTINUED MOISTURE INCREASE AND SATURATION OF SURFACE
LAYER OVER SNOWPACK.
WEAK ASCENT EARLY TO MID MORNING IN SOUTHWEST FLOW ALOFT WITH
INCOMING SHORTWAVE ENERGY COULD ALSO RESULT IN PATCHY FREEZING
DRIZZLE...BEST CHANCE OF SEEING MEASURABLE ZR- IN WESTERN HALF OF
CWA...BUT CONFIDENCE IS LOW IN ICE ACCUMULATIONS.
TEMPERATURE TRENDS WILL BE KEY TO EXTENT OF PROBLEMS TODAY WITH
FREEZING RAIN/DRIZZLE. UNTIL BETTER DEWPOINTS SOUTH OF OH RIVER
SURGE NORTHWARD...TEMPERATURES SHOULD VERY SLOWLY CLIMB. GUIDANCE IS
ALREADY A BIT TOO LOW ON CURRENT TEMPERATURES...SO THINK THAT ONCE
STRONGER MIDLEVEL WAVE/MOIST TRANSPORT ARRIVES EARLY TO MID
AFTERNOON...MOST IF NOT ALL AREAS SHOULD BE ABOVE FREEZING AND LIMIT
FREEZING RAIN THREAT. BIGGEST CONCERN IS FOR WI BORDER AREAS TO WARM
A BIT SLOWER AND THUS SEE A FEW HRS OF FREEZING RAIN BEFORE CHANGING
TO PLAIN RAIN. HAVE BETTER CONFIDENCE ROUGHLY SOUTH OF I-90 THAT
PLAIN RAIN WILL BE PREDOMINANT P-TYPE.
REGARDING RAIN AND SNOWMELT...STOUT MIDLEVEL WAVE AND ASSOCIATED
SURFACE LOW TRACKING WEST OF CWA WILL AIM PLUME OF 2-3 SD ABOVE
NORMAL/A BIT OVER .75 INCH PWAT/INTO AREA BY THIS EVENING. UNTIL
DRYSLOT ARRIVES LATE IN THE EVENING INTO THE OVERNIGHT AND SHUTS OFF
STEADY RAIN...THERE COULD BE PERIODS OF MODERATE RAIN. LOCAL WRF
GUIDANCE IS MUCH MORE BULLISH ON HOW WARM TEMPERATURES ARE THIS
EVENING/MID 40S FOR SOUTHEASTERN HALF OF CWA/WITH HEAVIEST RAINFALL.
IF TEMPERATURES ARE WARMER THAN UPPER 30S/LOW 40S/THIS COULD ENABLE
MORE RAPID SNOWMELT AND HEIGHTEN FLOODING CONCERNS. DO NOT HAVE
ENOUGH CONFIDENCE TO ISSUE ANY FLOOD WATCHES...BUT WILL CONTINUE
WITH PREVIOUSLY ISSUED ESF TO HIGHLIGHT FLOODING
POTENTIAL...INCLUDING BREAK UP ICE JAMS ON AREA RIVERS.
SATURDAY THROUGH SUNDAY NIGHT...
LOWERED POPS SATURDAY MORNING...WITH ONLY CHANCE POPS FOR FAR NORTH
AS DEFORMATION AXIS OF STRENGTHENING SURFACE AND UPPER SYSTEM OVER
THE REGION LOOKS TO AT BEST GRAZE THE FAR NORTH. MORE LIKELY
SCENARIO IS FOR DEFORMATION TO IMPACT CENTRAL WISCONSIN.
THEREFORE...WHILE THERMAL PROFILES WILL BECOME COLD ENOUGH...AT BEST
WOULD ONLY EXPECT LIGHT SNOW AND NO ACCUM IN FAR NORTHERN CWA. COOL
ADVECTION THROUGH THE DAY WILL RESULT IN ONLY A FEW DEGREE TEMP
CLIMB IN AFTERNOON FROM MORNING LOWS IN LOW-MID 30S.
THERE SHOULD BE ENOUGH TIME FOR WET SURFACES TO DRY OFF TO PRECLUDE
A BIG THREAT OF ICY SPOTS ON ROAD SURFACES SATURDAY NIGHT AS
TEMPERATURES FALL INTO THE TEENS AND 20S. RAPID WARM ADVECTION
PATTERN THEN SETS UP ON SUNDAY AS H85 TEMPS WARM BACK UP TO +6 TO
+8C. A LOOK AT FORECAST SOUNDINGS INDICATES THAT GLOBAL MODELS MAY
BE STRUGGLING WITH LOWER LEVEL THERMAL PROFILES DUE TO TRYING TO
RESOLVE EXISTING SNOWPACK. AS A RESULT...925 MB TEMPS ON HIGHER RES
NAM OF +6 TO +8C MAY BE THE BETTER ROUTE THAN LOW POSITIVE SINGLE
DIGITS. ASSUMING THAT MOST OF THE AREA STILL HAS AT LEAST 1 INCH OF
SNOW ON THE GROUND...WARMING POTENTIAL WILL BE LESS THAN WITHOUT
SNOW. HOWEVER...SOUTHERN EDGE OF SNOWPACK WILL LIKELY BE QUICKLY
ERODING...WITH MID 40S IF NOT WARMER POSSIBLE IN SOUTHERN CWA. ONLY
AREAS LIMITED TO THE UPPER 30S MAY BE THE FAR NORTHWEST. A COLD
FRONT TRAILING FROM CLIPPER SYSTEM OVER NORTHERN LAKES WILL THEN
SWING THROUGH CWA SUNDAY NIGHT LIKELY DRY EXCEPT PERHAPS FAR NORTH
WHERE SLIGHT POPS WERE MAINTAINED.
LONG TERM...MONDAY THROUGH THURSDAY...
OVERALL UPPER PATTERN WILL REALIGN TO A RIDGE IN THE WEST/TROUGH IN
THE EAST...WHICH IS KNOWN AS A POSITIVE PNA PATTERN. THIS IS
TYPICALLY A COLDER BUT FAIRLY DRY SET-UP FOR THE LOCAL AREA. WILL
NEED TO WATCH FOR CLIPPER TYPE SYSTEMS IN NORTHWEST FLOW ALOFT.
GUIDANCE BECOMES SPLIT ON WHETHER TO FOCUS MORE ENERGY IN SOUTHERN
STREAM SYSTEM OR NORTHERN VORT ON MONDAY NIGHT INTO TUESDAY. IN
PARTICULAR...ECMWF IS OF MOST INTEREST WITH ITS STRONGER SOUTHERN
STREAM WAVE. IF A QUICKER PHASE OCCURS WITH NORTHERN BRANCH
FEATURE...MORE THAN SOUTHEAST CWA COULD BE IMPACTED BY A SYSTEM IN
THIS TIMEFRAME. OPERATIONAL GFS DOES NOT SEEM TO HAVE MUCH ENSEMBLE
SUPPORT WITH ITS UNUSUALLY STRONG CLIPPER SYSTEM TRACKING ACROSS THE
AREA ON MONDAY NIGHT. HAVE SLIGHT TO LOW POPS MONDAY NIGHT INTO
TUESDAY...WITH THE POSSIBILITY THEN OF MORE CLIPPER ACITIVITY LATER
NEXT WEEK. IN BETWEEN LOOKS TO BE PRIMARILY DRY...WITH LAKE EFFECT
SNOW FOCUSED EAST OF FAR EASTERN CWA. THE CORE OF THE COLDEST AIR
DURING THIS TIME WILL REMAIN NORTH OF US WITH POLAR VORTEX OVER
HUDSON BAY...BUT OTHER THAN A BRIEF WARM-UP ON
THURSDAY...TEMPERATURES ARE LIKELY TO AVERAGE BELOW NORMAL THROUGH
EXTENDED AND BEYOND.
RC
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* LOW CEILINGS CONTINUING THROUGH THE REST OF THE DAY...IMPROVING
BEHIND COLD FRONT EARLY TOMORROW.
* VSBY GENERALLY 1-3SM...BUT POSSIBLY LESS THAN A QUARTER MILE IF
DENSE FOG WERE TO DEVELOP.
BMD
//DISCUSSION...UPDATED 18Z...
A WASHED OUT WARM FRONT IS LIFTING INTO ILLINOIS EARLY THIS
AFTERNOON...WITH A BROAD DEWPOINT GRADIENT SPREADING NORTHWARD
ACROSS THE STATE. NORTH OF THE FRONT...CIGS ARE GENERALLY BETWEEN
002 AND 005 WHILE VSBY IS MORE VARIABLE...BUT NUMEROUS 1-3SM REPORTS
ARE NOTED ACROSS FAR NORTHERN ILLINOIS DUE TO FOG/MIST. AS LOW
PRESSURE TRACKS FROM EASTERN NEBRASKA THIS AFTERNOON INTO SOUTHERN
WISCONSIN LATER THIS EVENING...EXPECT NORTHWARD MOISTURE TRANSPORT TO
CONTINUE WITH DEWPOINTS RISING INTO THE MID OR UPPER 30S OVER THE
SNOWPACK. THE IMMEDIATE CONCERN HERE IS FOR THE POTENTIAL OF DENSE
FOG DEVELOPING...WITH MET GUIDANCE INDICATING VSBY TANKING THIS
AFTERNOON. FEEL GUIDANCE MAY BE HITTING THIS TOO HARD THOUGH GIVEN
THE BROAD TD GRADIENT...AND WILL LEAN TOWARDS A MORE OPTIMISTIC VSBY
FORECAST...ADMITTEDLY WITH LOW CONFIDENCE CONSIDERING THE MORE
WIDESPREAD 1/4 TO 1/2 SM VSBY IMMEDIATELY AHEAD OF THE LOW.
SHOWERS WILL OVERSPREAD THE AREA THIS AFTERNOON AS A POTENT UPPER
WAVE LIFTS ACROSS THE REGION. MID LEVEL LAPSE RATES MAY BE
SUFFICIENTLY STEEP ENOUGH TO SUPPORT EMBEDDED THUNDERSTORMS AS FAR
NORTH AS THE CHICAGO TERMINALS...HOWEVER FELL BEST CHANCES FOR FOR
THUNDER WILL STAY SOUTH OF THE I-80 CORRIDOR. RAIN IS EXPECTED TO BE
MODERATE WITH BRIEFLY HEAVY SHOWERS POSSIBLE. DEEPER MOISTURE WILL
PUSH OUT OF THE AREA MID TO LATE THIS EVENING WITH LINGERING DRIZZLE
POSSIBLE INTO THE EARLY OVERNIGHT HOURS. FEEL THAT ONCE THE RAIN
STOPS THIS EVENING...THIS WILL BE THE PERIOD THAT MAY HAVE TO BE
MONITORED MOST CLOSELY FOR FOG DEVELOPING. DEWPOINTS SHOULD BE
CLIMBING INTO THE 35-37 RANGE BY THIS POINT WHICH ASSUMING THERE IS
STILL SOME SNOW ON THE GROUND WOULD BE FAVORABLE FOR FOG TO INCREASE
IN THICKNESS. UNFORTUNATELY...MET/MAV GUIDANCE SHOWS THE
OPPOSITE...WITH IMPROVING VSBY TRENDS AFTER THE RAIN DEPARTS
OVERNIGHT...ONCE AGAIN RESULTING IN VERY LOW CONFIDENCE IN VSBY
FCST. WILL STICK WITH GOING VSBY TRENDS THIS PERIOD UNTIL HAVE
HIGHER CONFIDENCE IN A SOLUTION.
A COLD FRONT WILL SWEEP ACROSS THE AREA EARLY SATURDAY. WHILE
NOTABLE DRYING OCCURS ALOFT...APPEARS WE MAY STICK FOR SEVERAL HOURS
WITH SOME POST FRONTAL STRATUS...AT LEAST UNTIL SATURDAY AFTERNOON
WHEN IT MAY FINALLY SCATTER OUT. VSBY SHOULD SHARPLY IMPROVE BEHIND
THE FRONT THOUGH WITH WINDS TURNING WESTERLY AND BECOMING
INCREASINGLY GUSTY.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* VERY LOW CONFIDENCE IN VSBY TRENDS TODAY AND TONIGHT.
* HIGH CONFIDENCE IN IFR OR LOWER CIGS THROUGH THE OVERNIGHT HOURS.
* HIGH CONFIDENCE IN RAIN TIMING.
* MEDIUM-HIGH CONFIDENCE IN WIND DIRECTION...MEDIUM CONFIDENCE IN
WIND SPEED.
BMD
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT...VFR PROBABLE.
SUNDAY...STRONG SOUTH WINDS...LLWS POSSIBLE AFTERNOON/EARLY
EVENING. VFR PROBABLE.
MONDAY...VFR.
TUESDAY...CHANCE OF SNOW/IFR.
WEDNESDAY AND THURSDAY...VFR PROBABLE.
IZZI
&&
.MARINE...
209 PM CST
LARGE DOME OF HIGH PRESSURE OVER THE EASTERN SEABOARD HAS DRIFTED
EAST...AND STRETCHES FROM CENTRAL QUEBEC SOUTH THROUGH THE CAROLINA
COAST. MEANWHILE ACROSS THE CENTRAL PLAINS A SERIES OF LOW PRESSURES
EXISTED...WITH ONE ACROSS THE NORTHERN PLAINS AND THE SECOND ACROSS
THE CENTRAL PLAINS. THESE TWO AREAS OF LOW PRESSURES WILL CONVERGE
UPON LAKE MICHIGAN...CONSOLIDATING INTO A SLIGHTLY STRONGER LOW
PRESSURE OVER THE NORTHERN PORTION OF LAKE MICHIGAN EARLY SATURDAY
MORNING. WINDS FOR MUCH OF THE LAKE WILL REMAIN SOUTHERLY...WITH THE
FAR NORTHERN PORTIONS NEAR THE STRAITS OF MACKINAW BEING SLIGHTLY
SOUTHEAST/EAST. THEN WITH THE LOW PASSAGE EXPECTED TO OCCUR SATURDAY
MORNING WITH A TRAILING FRONTAL BOUNDARY SLIDING EAST ACROSS THE
LAKE...THE GRADIENT IS EXPECTED TO TIGHTEN. FOR THE CENTRAL/SOUTHERN
PORTIONS WINDS WILL INCREASE TO NEAR 30 KT BY MIDDAY/EARLY AFTN SAT.
THEN AS THE FRONTAL BOUNDARY CONTINUES TO PRESS EAST...WINDS WILL
TURN MORE TO THE WEST. FOR THE NORTHERN HALF OF THE LAKE WINDS FOR A
PERIOD WILL BECOME NORTHWEST...BEFORE RELAXING TO THE WEST SAT LATE
AFTN.
HIGH PRESSURE ACROSS THE SOUTHERN PLAINS SAT AFTN WILL CONTINUE TO
SLIDE EAST...STRETCHING AN INFLUENCE NORTH TO LAKE MICHIGAN SATURDAY
NIGHT/EARLY SUN. THIS COUPLED WITH YET ANOTHER LOW PRESSURE SYSTEM
BEGINNING TO PUSH INTO CENTRAL CANADA...WILL ALLOW THE GRADIENT TO
TIGHTEN. WINDS SHOULD REMAIN BREEZY SUN AFTN/EVE. THE GRADIENT HAS
BECOME SLIGHTLY TIGHTER...ALONG WITH THE LOW PRESSURE BECOME DEEPER
TO 28.9 INCHES JUST NORTH OF LAKE SUPERIOR SUN EVE. THIS WILL LIKELY
CREATE A PERIOD OF GALES FOR THE LAKE DURING THE SUN AFTN/EVE
TIMEFRAME. THE GRADIENT THEN BEGINS TO SLACKEN OFF FOR THE MIDDLE OF
NEXT WEEK...WITH JUST A COUPLE WEAK WAVES TRAVERSING THE WESTERN
GREAT LAKES REGION. IN THE LONGER RANGE PERIODS FORECAST GUIDANCE IS
BEGINNING TO INDICATE A STRENGTHENING LOW PRESSURE OVER THE OHIO
VALLEY TUE NIGHT...WHICH COULD RESULT IN A TIGHTENING GRADIENT FOR
LAKE MICHIGAN WED AND BREEZY CONDITIONS RETURNING.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
200 PM CST FRI JAN 10 2014
.DISCUSSION...
1114 AM CST
HAVE SPENT THE MORNING EXAMINING THE POTENTIAL FOR DENSE FOG AND
THE POSSIBLE NEED FOR AN ADVISORY LATER TODAY...THE APPROACHING
THUNDERSTORMS IN WEST CENTRAL ILLINOIS...AND THE FLOOD POTENTIAL
GIVEN THE EXPECTED RAINFALL AND WARMING TEMPERATURES.
FOR THE NEAR TERM WE ELECTED TO CANCEL THE FREEZING FOG ADVISORY A
LITTLE EARLY AS TEMPERATURES IN MOST LOCATIONS HAVE RISEN ABOVE OR
VERY NEAR FREEZING. THE NEXT QUESTION WOULD BE WHETHER DENSE FOG
DEVELOPS IN THE SATURATED SURFACE LAYER MOVING IN OVER THE
SNOWPACK WITH INCREASING DEWPOINTS. OBSERVATIONS JUST UPSTREAM OF
THE AREA ARE SHOWING VSBYS AT WORST AROUND 1 MILE...BUT FARTHER
UPSTREAM TOWARD THE APPROACHING LOW CENTER THEY ARE MORE COMMONLY
AROUND 1/4 TO 1/2 MILE. SO FOR THE AFTERNOON AM NOT ANTICIPATING
THE NEED FOR FOG HEADLINES...BUT WILL REEVALUATE LATER TODAY IN
CASE SOMETHING MAY BE NEEDED THIS EVENING OR OVERNIGHT.
THE AREA OF THUNDERSTORMS AROUND QUINCY AND SOUTHWEST TOWARD
JOPLIN MISSOURI IS WELL CORRELATED WITH AN AREA OF ENHANCED LOW
LEVEL MOISTURE FLUX SHOWN IN THE RAP MODEL EAST OF THE
APPROACHING LOW PRESSURE CENTER. AS THE AFTERNOON EVOLVES AND THE
LOW LIFTS NORTHEAST...THE RAP MODEL INCREASES THE MOISTURE FLUX
OVER CENTRAL AND NORTHERN ILLINOIS. AREAS OF STEEPER LAPSE RATES
ARE ALSO SEEN IN NAM/GFS SOUNDINGS FOR THE AFTERNOON AND EVENING
TIMEFRAME. WILL UPDATE FCST GRIDS TO INTRODUCE A SLIGHT CHANCE OF
TSTMS MAINLY FOR THE SOUTHERN HALF OF THE AREA.
AS FOR FLOODING POTENTIAL...AM NOT PLANNING ON ANY FLOOD WATCH
HEADLINES AT THIS TIME GIVEN SO MANY VARIABLES...INCLUDING
LOCATION OF HEAVIER RAIN AMOUNTS...DEGREE TO WHICH THE SNOWPACK
WOULD SPONGE UP THE RAIN...EVOLUTION OF DEWPOINT
TEMPERATURES...AND THE BEHAVIOR OF ICE ON THE RIVERS AND STREAMS.
THE BEST POTENTIAL FOR MAINSTEM FLOODING APPEARS TO BE ALONG THE
KANKAKEE WHERE A FLOOD WARNING HAS BEEN ISSUED FOR ANTICIPATED MINOR
FLOODING. THIS RIVER ALREADY HAD QUITE A BIT OF WATER IN IT...BUT
THE OTHERS HAVE A LITTLE MORE ROOM TO HANDLE THE RUNOFF.
LENNING
//PREV DISCUSSION...
338 AM CST
SHORT TERM...TODAY THROUGH SUNDAY NIGHT
TODAY/TONIGHT...
MULTIPLE CONCERNS IN THE NEAR TERM TODAY...INCLUDING DENSE
FOG...FREEZING DRIZZLE/RAIN AND THEN RAIN AND MELTING SNOW LATER
TODAY INTO THIS EVENING.
GRADUAL INCREASE IN SURFACE MOISTURE OVER DEEP SNOW PACK HAS
RESULTED IN FOG DEVELOPMENT EARLY THIS MORNING...WITH MULTIPLE
LOCATIONS AOB 1/2 MILE. FOG HAS BEEN MOST DENSE ALONG/WEST OF A LINE
FROM UGN TO VYS. WILL LIKELY NEED A DENSE FOG ADVISORY ADVISORY OR
FREEZING FOG ADVISORY FOR MOST IF NOT ALL IF THIS AREA FOR PART OF
TODAY UNTIL TEMPERATURES WARM AND STEADIER PRECIP ARRIVES
LATER...WITH CONTINUED MOISTURE INCREASE AND SATURATION OF SURFACE
LAYER OVER SNOWPACK.
WEAK ASCENT EARLY TO MID MORNING IN SOUTHWEST FLOW ALOFT WITH
INCOMING SHORTWAVE ENERGY COULD ALSO RESULT IN PATCHY FREEZING
DRIZZLE...BEST CHANCE OF SEEING MEASURABLE ZR- IN WESTERN HALF OF
CWA...BUT CONFIDENCE IS LOW IN ICE ACCUMULATIONS.
TEMPERATURE TRENDS WILL BE KEY TO EXTENT OF PROBLEMS TODAY WITH
FREEZING RAIN/DRIZZLE. UNTIL BETTER DEWPOINTS SOUTH OF OH RIVER
SURGE NORTHWARD...TEMPERATURES SHOULD VERY SLOWLY CLIMB. GUIDANCE IS
ALREADY A BIT TOO LOW ON CURRENT TEMPERATURES...SO THINK THAT ONCE
STRONGER MIDLEVEL WAVE/MOIST TRANSPORT ARRIVES EARLY TO MID
AFTERNOON...MOST IF NOT ALL AREAS SHOULD BE ABOVE FREEZING AND LIMIT
FREEZING RAIN THREAT. BIGGEST CONCERN IS FOR WI BORDER AREAS TO WARM
A BIT SLOWER AND THUS SEE A FEW HRS OF FREEZING RAIN BEFORE CHANGING
TO PLAIN RAIN. HAVE BETTER CONFIDENCE ROUGHLY SOUTH OF I-90 THAT
PLAIN RAIN WILL BE PREDOMINANT P-TYPE.
REGARDING RAIN AND SNOWMELT...STOUT MIDLEVEL WAVE AND ASSOCIATED
SURFACE LOW TRACKING WEST OF CWA WILL AIM PLUME OF 2-3 SD ABOVE
NORMAL/A BIT OVER .75 INCH PWAT/INTO AREA BY THIS EVENING. UNTIL
DRYSLOT ARRIVES LATE IN THE EVENING INTO THE OVERNIGHT AND SHUTS OFF
STEADY RAIN...THERE COULD BE PERIODS OF MODERATE RAIN. LOCAL WRF
GUIDANCE IS MUCH MORE BULLISH ON HOW WARM TEMPERATURES ARE THIS
EVENING/MID 40S FOR SOUTHEASTERN HALF OF CWA/WITH HEAVIEST RAINFALL.
IF TEMPERATURES ARE WARMER THAN UPPER 30S/LOW 40S/THIS COULD ENABLE
MORE RAPID SNOWMELT AND HEIGHTEN FLOODING CONCERNS. DO NOT HAVE
ENOUGH CONFIDENCE TO ISSUE ANY FLOOD WATCHES...BUT WILL CONTINUE
WITH PREVIOUSLY ISSUED ESF TO HIGHLIGHT FLOODING
POTENTIAL...INCLUDING BREAK UP ICE JAMS ON AREA RIVERS.
SATURDAY THROUGH SUNDAY NIGHT...
LOWERED POPS SATURDAY MORNING...WITH ONLY CHANCE POPS FOR FAR NORTH
AS DEFORMATION AXIS OF STRENGTHENING SURFACE AND UPPER SYSTEM OVER
THE REGION LOOKS TO AT BEST GRAZE THE FAR NORTH. MORE LIKELY
SCENARIO IS FOR DEFORMATION TO IMPACT CENTRAL WISCONSIN.
THEREFORE...WHILE THERMAL PROFILES WILL BECOME COLD ENOUGH...AT BEST
WOULD ONLY EXPECT LIGHT SNOW AND NO ACCUM IN FAR NORTHERN CWA. COOL
ADVECTION THROUGH THE DAY WILL RESULT IN ONLY A FEW DEGREE TEMP
CLIMB IN AFTERNOON FROM MORNING LOWS IN LOW-MID 30S.
THERE SHOULD BE ENOUGH TIME FOR WET SURFACES TO DRY OFF TO PRECLUDE
A BIG THREAT OF ICY SPOTS ON ROAD SURFACES SATURDAY NIGHT AS
TEMPERATURES FALL INTO THE TEENS AND 20S. RAPID WARM ADVECTION
PATTERN THEN SETS UP ON SUNDAY AS H85 TEMPS WARM BACK UP TO +6 TO
+8C. A LOOK AT FORECAST SOUNDINGS INDICATES THAT GLOBAL MODELS MAY
BE STRUGGLING WITH LOWER LEVEL THERMAL PROFILES DUE TO TRYING TO
RESOLVE EXISTING SNOWPACK. AS A RESULT...925 MB TEMPS ON HIGHER RES
NAM OF +6 TO +8C MAY BE THE BETTER ROUTE THAN LOW POSITIVE SINGLE
DIGITS. ASSUMING THAT MOST OF THE AREA STILL HAS AT LEAST 1 INCH OF
SNOW ON THE GROUND...WARMING POTENTIAL WILL BE LESS THAN WITHOUT
SNOW. HOWEVER...SOUTHERN EDGE OF SNOWPACK WILL LIKELY BE QUICKLY
ERODING...WITH MID 40S IF NOT WARMER POSSIBLE IN SOUTHERN CWA. ONLY
AREAS LIMITED TO THE UPPER 30S MAY BE THE FAR NORTHWEST. A COLD
FRONT TRAILING FROM CLIPPER SYSTEM OVER NORTHERN LAKES WILL THEN
SWING THROUGH CWA SUNDAY NIGHT LIKELY DRY EXCEPT PERHAPS FAR NORTH
WHERE SLIGHT POPS WERE MAINTAINED.
LONG TERM...MONDAY THROUGH THURSDAY...
OVERALL UPPER PATTERN WILL REALIGN TO A RIDGE IN THE WEST/TROUGH IN
THE EAST...WHICH IS KNOWN AS A POSITIVE PNA PATTERN. THIS IS
TYPICALLY A COLDER BUT FAIRLY DRY SET-UP FOR THE LOCAL AREA. WILL
NEED TO WATCH FOR CLIPPER TYPE SYSTEMS IN NORTHWEST FLOW ALOFT.
GUIDANCE BECOMES SPLIT ON WHETHER TO FOCUS MORE ENERGY IN SOUTHERN
STREAM SYSTEM OR NORTHERN VORT ON MONDAY NIGHT INTO TUESDAY. IN
PARTICULAR...ECMWF IS OF MOST INTEREST WITH ITS STRONGER SOUTHERN
STREAM WAVE. IF A QUICKER PHASE OCCURS WITH NORTHERN BRANCH
FEATURE...MORE THAN SOUTHEAST CWA COULD BE IMPACTED BY A SYSTEM IN
THIS TIMEFRAME. OPERATIONAL GFS DOES NOT SEEM TO HAVE MUCH ENSEMBLE
SUPPORT WITH ITS UNUSUALLY STRONG CLIPPER SYSTEM TRACKING ACROSS THE
AREA ON MONDAY NIGHT. HAVE SLIGHT TO LOW POPS MONDAY NIGHT INTO
TUESDAY...WITH THE POSSIBILITY THEN OF MORE CLIPPER ACITIVITY LATER
NEXT WEEK. IN BETWEEN LOOKS TO BE PRIMARILY DRY...WITH LAKE EFFECT
SNOW FOCUSED EAST OF FAR EASTERN CWA. THE CORE OF THE COLDEST AIR
DURING THIS TIME WILL REMAIN NORTH OF US WITH POLAR VORTEX OVER
HUDSON BAY...BUT OTHER THAN A BRIEF WARM-UP ON
THURSDAY...TEMPERATURES ARE LIKELY TO AVERAGE BELOW NORMAL THROUGH
EXTENDED AND BEYOND.
RC
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* LOW CEILINGS CONTINUING THROUGH THE REST OF THE DAY...IMPROVING
BEHIND COLD FRONT EARLY TOMORROW.
* VSBY GENERALLY 1-3SM...BUT POSSIBLY LESS THAN A QUARTER MILE IF
DENSE FOG WERE TO DEVELOP.
BMD
//DISCUSSION...UPDATED 18Z...
A WASHED OUT WARM FRONT IS LIFTING INTO ILLINOIS EARLY THIS
AFTERNOON...WITH A BROAD DEWPOINT GRADIENT SPREADING NORTHWARD
ACROSS THE STATE. NORTH OF THE FRONT...CIGS ARE GENERALLY BETWEEN
002 AND 005 WHILE VSBY IS MORE VARIABLE...BUT NUMEROUS 1-3SM REPORTS
ARE NOTED ACROSS FAR NORTHERN ILLINOIS DUE TO FOG/MIST. AS LOW
PRESSURE TRACKS FROM EASTERN NEBRASKA THIS AFTERNOON INTO SOUTHERN
WISCONSIN LATER THIS EVENING...EXPECT NORTHWARD MOISTURE TRANSPORT TO
CONTINUE WITH DEWPOINTS RISING INTO THE MID OR UPPER 30S OVER THE
SNOWPACK. THE IMMEDIATE CONCERN HERE IS FOR THE POTENTIAL OF DENSE
FOG DEVELOPING...WITH MET GUIDANCE INDICATING VSBY TANKING THIS
AFTERNOON. FEEL GUIDANCE MAY BE HITTING THIS TOO HARD THOUGH GIVEN
THE BROAD TD GRADIENT...AND WILL LEAN TOWARDS A MORE OPTIMISTIC VSBY
FORECAST...ADMITTEDLY WITH LOW CONFIDENCE CONSIDERING THE MORE
WIDESPREAD 1/4 TO 1/2 SM VSBY IMMEDIATELY AHEAD OF THE LOW.
SHOWERS WILL OVERSPREAD THE AREA THIS AFTERNOON AS A POTENT UPPER
WAVE LIFTS ACROSS THE REGION. MID LEVEL LAPSE RATES MAY BE
SUFFICIENTLY STEEP ENOUGH TO SUPPORT EMBEDDED THUNDERSTORMS AS FAR
NORTH AS THE CHICAGO TERMINALS...HOWEVER FELL BEST CHANCES FOR FOR
THUNDER WILL STAY SOUTH OF THE I-80 CORRIDOR. RAIN IS EXPECTED TO BE
MODERATE WITH BRIEFLY HEAVY SHOWERS POSSIBLE. DEEPER MOISTURE WILL
PUSH OUT OF THE AREA MID TO LATE THIS EVENING WITH LINGERING DRIZZLE
POSSIBLE INTO THE EARLY OVERNIGHT HOURS. FEEL THAT ONCE THE RAIN
STOPS THIS EVENING...THIS WILL BE THE PERIOD THAT MAY HAVE TO BE
MONITORED MOST CLOSELY FOR FOG DEVELOPING. DEWPOINTS SHOULD BE
CLIMBING INTO THE 35-37 RANGE BY THIS POINT WHICH ASSUMING THERE IS
STILL SOME SNOW ON THE GROUND WOULD BE FAVORABLE FOR FOG TO INCREASE
IN THICKNESS. UNFORTUNATELY...MET/MAV GUIDANCE SHOWS THE
OPPOSITE...WITH IMPROVING VSBY TRENDS AFTER THE RAIN DEPARTS
OVERNIGHT...ONCE AGAIN RESULTING IN VERY LOW CONFIDENCE IN VSBY
FCST. WILL STICK WITH GOING VSBY TRENDS THIS PERIOD UNTIL HAVE
HIGHER CONFIDENCE IN A SOLUTION.
A COLD FRONT WILL SWEEP ACROSS THE AREA EARLY SATURDAY. WHILE
NOTABLE DRYING OCCURS ALOFT...APPEARS WE MAY STICK FOR SEVERAL HOURS
WITH SOME POST FRONTAL STRATUS...AT LEAST UNTIL SATURDAY AFTERNOON
WHEN IT MAY FINALLY SCATTER OUT. VSBY SHOULD SHARPLY IMPROVE BEHIND
THE FRONT THOUGH WITH WINDS TURNING WESTERLY AND BECOMING
INCREASINGLY GUSTY.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* VERY LOW CONFIDENCE IN VSBY TRENDS TODAY AND TONIGHT.
* HIGH CONFIDENCE IN IFR OR LOWER CIGS THROUGH THE OVERNIGHT HOURS.
* HIGH CONFIDENCE IN RAIN TIMING.
* MEDIUM-HIGH CONFIDENCE IN WIND DIRECTION...MEDIUM CONFIDENCE IN
WIND SPEED.
BMD
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT...VFR PROBABLE.
SUNDAY...STRONG SOUTH WINDS...LLWS POSSIBLE AFTERNOON/EARLY
EVENING. VFR PROBABLE.
MONDAY...VFR.
TUESDAY...CHANCE OF SNOW/IFR.
WEDNESDAY AND THURSDAY...VFR PROBABLE.
IZZI
&&
.MARINE...
417 AM CST
SOUTH WINDS WILL RAMP UP TODAY IN ADVANCE OF DEVELOPING LOW PRESSURE
OVER THE CORNBELT THIS AFTERNOON. THIS LOW WILL TRACK ACROSS
NORTHERN LM LATE TONIGHT/EARLY SAT AM ON ITS WAY TO QUEBEC BY
SUNDAY. WEAK RIDGE TRAVERSES THE LAKE SAT NIGHT BEFORE A VERY STRONG
LOW RACES EAST ACROSS SOUTHERN CANADA SUNDAY RESULTING IN WHAT LOOKS
TO BE A PRETTY GOOD SHOT OF SOUTH GALES SUNDAY INTO SUNDAY EVENING.
MODELS STRONGLY DIVERGE ON STRENGTH AND TIMING OF NORTHWEST FLOW
DISTURBANCES IN THE TUES/WED TIME RANGE RESULTING IN LOW CONFIDENCE
FORECAST.
IZZI
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1201 PM CST FRI JAN 10 2014
.DISCUSSION...
1114 AM CST
HAVE SPENT THE MORNING EXAMINING THE POTENTIAL FOR DENSE FOG AND
THE POSSIBLE NEED FOR AN ADVISORY LATER TODAY...THE APPROACHING
THUNDERSTORMS IN WEST CENTRAL ILLINOIS...AND THE FLOOD POTENTIAL
GIVEN THE EXPECTED RAINFALL AND WARMING TEMPERATURES.
FOR THE NEAR TERM WE ELECTED TO CANCEL THE FREEZING FOG ADVISORY A
LITTLE EARLY AS TEMPERATURES IN MOST LOCATIONS HAVE RISEN ABOVE OR
VERY NEAR FREEZING. THE NEXT QUESTION WOULD BE WHETHER DENSE FOG
DEVELOPS IN THE SATURATED SURFACE LAYER MOVING IN OVER THE
SNOWPACK WITH INCREASING DEWPOINTS. OBSERVATIONS JUST UPSTREAM OF
THE AREA ARE SHOWING VSBYS AT WORST AROUND 1 MILE...BUT FARTHER
UPSTREAM TOWARD THE APPROACHING LOW CENTER THEY ARE MORE COMMONLY
AROUND 1/4 TO 1/2 MILE. SO FOR THE AFTERNOON AM NOT ANTICIPATING
THE NEED FOR FOG HEADLINES...BUT WILL REEVALUATE LATER TODAY IN
CASE SOMETHING MAY BE NEEDED THIS EVENING OR OVERNIGHT.
THE AREA OF THUNDERSTORMS AROUND QUINCY AND SOUTHWEST TOWARD
JOPLIN MISSOURI IS WELL CORRELATED WITH AN AREA OF ENHANCED LOW
LEVEL MOISTURE FLUX SHOWN IN THE RAP MODEL EAST OF THE
APPROACHING LOW PRESSURE CENTER. AS THE AFTERNOON EVOLVES AND THE
LOW LIFTS NORTHEAST...THE RAP MODEL INCREASES THE MOISTURE FLUX
OVER CENTRAL AND NORTHERN ILLINOIS. AREAS OF STEEPER LAPSE RATES
ARE ALSO SEEN IN NAM/GFS SOUNDINGS FOR THE AFTERNOON AND EVENING
TIMEFRAME. WILL UPDATE FCST GRIDS TO INTRODUCE A SLIGHT CHANCE OF
TSTMS MAINLY FOR THE SOUTHERN HALF OF THE AREA.
AS FOR FLOODING POTENTIAL...AM NOT PLANNING ON ANY FLOOD WATCH
HEADLINES AT THIS TIME GIVEN SO MANY VARIABLES...INCLUDING
LOCATION OF HEAVIER RAIN AMOUNTS...DEGREE TO WHICH THE SNOWPACK
WOULD SPONGE UP THE RAIN...EVOLUTION OF DEWPOINT
TEMPERATURES...AND THE BEHAVIOR OF ICE ON THE RIVERS AND STREAMS.
THE BEST POTENTIAL FOR MAINSTEM FLOODING APPEARS TO BE ALONG THE
KANKAKEE WHERE A FLOOD WARNING HAS BEEN ISSUED FOR ANTICIPATED MINOR
FLOODING. THIS RIVER ALREADY HAD QUITE A BIT OF WATER IN IT...BUT
THE OTHERS HAVE A LITTLE MORE ROOM TO HANDLE THE RUNOFF.
LENNING
//PREV DISCUSSION...
338 AM CST
SHORT TERM...TODAY THROUGH SUNDAY NIGHT
TODAY/TONIGHT...
MULTIPLE CONCERNS IN THE NEAR TERM TODAY...INCLUDING DENSE
FOG...FREEZING DRIZZLE/RAIN AND THEN RAIN AND MELTING SNOW LATER
TODAY INTO THIS EVENING.
GRADUAL INCREASE IN SURFACE MOISTURE OVER DEEP SNOW PACK HAS
RESULTED IN FOG DEVELOPMENT EARLY THIS MORNING...WITH MULTIPLE
LOCATIONS AOB 1/2 MILE. FOG HAS BEEN MOST DENSE ALONG/WEST OF A LINE
FROM UGN TO VYS. WILL LIKELY NEED A DENSE FOG ADVISORY ADVISORY OR
FREEZING FOG ADVISORY FOR MOST IF NOT ALL IF THIS AREA FOR PART OF
TODAY UNTIL TEMPERATURES WARM AND STEADIER PRECIP ARRIVES
LATER...WITH CONTINUED MOISTURE INCREASE AND SATURATION OF SURFACE
LAYER OVER SNOWPACK.
WEAK ASCENT EARLY TO MID MORNING IN SOUTHWEST FLOW ALOFT WITH
INCOMING SHORTWAVE ENERGY COULD ALSO RESULT IN PATCHY FREEZING
DRIZZLE...BEST CHANCE OF SEEING MEASURABLE ZR- IN WESTERN HALF OF
CWA...BUT CONFIDENCE IS LOW IN ICE ACCUMULATIONS.
TEMPERATURE TRENDS WILL BE KEY TO EXTENT OF PROBLEMS TODAY WITH
FREEZING RAIN/DRIZZLE. UNTIL BETTER DEWPOINTS SOUTH OF OH RIVER
SURGE NORTHWARD...TEMPERATURES SHOULD VERY SLOWLY CLIMB. GUIDANCE IS
ALREADY A BIT TOO LOW ON CURRENT TEMPERATURES...SO THINK THAT ONCE
STRONGER MIDLEVEL WAVE/MOIST TRANSPORT ARRIVES EARLY TO MID
AFTERNOON...MOST IF NOT ALL AREAS SHOULD BE ABOVE FREEZING AND LIMIT
FREEZING RAIN THREAT. BIGGEST CONCERN IS FOR WI BORDER AREAS TO WARM
A BIT SLOWER AND THUS SEE A FEW HRS OF FREEZING RAIN BEFORE CHANGING
TO PLAIN RAIN. HAVE BETTER CONFIDENCE ROUGHLY SOUTH OF I-90 THAT
PLAIN RAIN WILL BE PREDOMINANT P-TYPE.
REGARDING RAIN AND SNOWMELT...STOUT MIDLEVEL WAVE AND ASSOCIATED
SURFACE LOW TRACKING WEST OF CWA WILL AIM PLUME OF 2-3 SD ABOVE
NORMAL/A BIT OVER .75 INCH PWAT/INTO AREA BY THIS EVENING. UNTIL
DRYSLOT ARRIVES LATE IN THE EVENING INTO THE OVERNIGHT AND SHUTS OFF
STEADY RAIN...THERE COULD BE PERIODS OF MODERATE RAIN. LOCAL WRF
GUIDANCE IS MUCH MORE BULLISH ON HOW WARM TEMPERATURES ARE THIS
EVENING/MID 40S FOR SOUTHEASTERN HALF OF CWA/WITH HEAVIEST RAINFALL.
IF TEMPERATURES ARE WARMER THAN UPPER 30S/LOW 40S/THIS COULD ENABLE
MORE RAPID SNOWMELT AND HEIGHTEN FLOODING CONCERNS. DO NOT HAVE
ENOUGH CONFIDENCE TO ISSUE ANY FLOOD WATCHES...BUT WILL CONTINUE
WITH PREVIOUSLY ISSUED ESF TO HIGHLIGHT FLOODING
POTENTIAL...INCLUDING BREAK UP ICE JAMS ON AREA RIVERS.
SATURDAY THROUGH SUNDAY NIGHT...
LOWERED POPS SATURDAY MORNING...WITH ONLY CHANCE POPS FOR FAR NORTH
AS DEFORMATION AXIS OF STRENGTHENING SURFACE AND UPPER SYSTEM OVER
THE REGION LOOKS TO AT BEST GRAZE THE FAR NORTH. MORE LIKELY
SCENARIO IS FOR DEFORMATION TO IMPACT CENTRAL WISCONSIN.
THEREFORE...WHILE THERMAL PROFILES WILL BECOME COLD ENOUGH...AT BEST
WOULD ONLY EXPECT LIGHT SNOW AND NO ACCUM IN FAR NORTHERN CWA. COOL
ADVECTION THROUGH THE DAY WILL RESULT IN ONLY A FEW DEGREE TEMP
CLIMB IN AFTERNOON FROM MORNING LOWS IN LOW-MID 30S.
THERE SHOULD BE ENOUGH TIME FOR WET SURFACES TO DRY OFF TO PRECLUDE
A BIG THREAT OF ICY SPOTS ON ROAD SURFACES SATURDAY NIGHT AS
TEMPERATURES FALL INTO THE TEENS AND 20S. RAPID WARM ADVECTION
PATTERN THEN SETS UP ON SUNDAY AS H85 TEMPS WARM BACK UP TO +6 TO
+8C. A LOOK AT FORECAST SOUNDINGS INDICATES THAT GLOBAL MODELS MAY
BE STRUGGLING WITH LOWER LEVEL THERMAL PROFILES DUE TO TRYING TO
RESOLVE EXISTING SNOWPACK. AS A RESULT...925 MB TEMPS ON HIGHER RES
NAM OF +6 TO +8C MAY BE THE BETTER ROUTE THAN LOW POSITIVE SINGLE
DIGITS. ASSUMING THAT MOST OF THE AREA STILL HAS AT LEAST 1 INCH OF
SNOW ON THE GROUND...WARMING POTENTIAL WILL BE LESS THAN WITHOUT
SNOW. HOWEVER...SOUTHERN EDGE OF SNOWPACK WILL LIKELY BE QUICKLY
ERODING...WITH MID 40S IF NOT WARMER POSSIBLE IN SOUTHERN CWA. ONLY
AREAS LIMITED TO THE UPPER 30S MAY BE THE FAR NORTHWEST. A COLD
FRONT TRAILING FROM CLIPPER SYSTEM OVER NORTHERN LAKES WILL THEN
SWING THROUGH CWA SUNDAY NIGHT LIKELY DRY EXCEPT PERHAPS FAR NORTH
WHERE SLIGHT POPS WERE MAINTAINED.
LONG TERM...MONDAY THROUGH THURSDAY...
OVERALL UPPER PATTERN WILL REALIGN TO A RIDGE IN THE WEST/TROUGH IN
THE EAST...WHICH IS KNOWN AS A POSITIVE PNA PATTERN. THIS IS
TYPICALLY A COLDER BUT FAIRLY DRY SET-UP FOR THE LOCAL AREA. WILL
NEED TO WATCH FOR CLIPPER TYPE SYSTEMS IN NORTHWEST FLOW ALOFT.
GUIDANCE BECOMES SPLIT ON WHETHER TO FOCUS MORE ENERGY IN SOUTHERN
STREAM SYSTEM OR NORTHERN VORT ON MONDAY NIGHT INTO TUESDAY. IN
PARTICULAR...ECMWF IS OF MOST INTEREST WITH ITS STRONGER SOUTHERN
STREAM WAVE. IF A QUICKER PHASE OCCURS WITH NORTHERN BRANCH
FEATURE...MORE THAN SOUTHEAST CWA COULD BE IMPACTED BY A SYSTEM IN
THIS TIMEFRAME. OPERATIONAL GFS DOES NOT SEEM TO HAVE MUCH ENSEMBLE
SUPPORT WITH ITS UNUSUALLY STRONG CLIPPER SYSTEM TRACKING ACROSS THE
AREA ON MONDAY NIGHT. HAVE SLIGHT TO LOW POPS MONDAY NIGHT INTO
TUESDAY...WITH THE POSSIBILITY THEN OF MORE CLIPPER ACITIVITY LATER
NEXT WEEK. IN BETWEEN LOOKS TO BE PRIMARILY DRY...WITH LAKE EFFECT
SNOW FOCUSED EAST OF FAR EASTERN CWA. THE CORE OF THE COLDEST AIR
DURING THIS TIME WILL REMAIN NORTH OF US WITH POLAR VORTEX OVER
HUDSON BAY...BUT OTHER THAN A BRIEF WARM-UP ON
THURSDAY...TEMPERATURES ARE LIKELY TO AVERAGE BELOW NORMAL THROUGH
EXTENDED AND BEYOND.
RC
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* LOW CEILINGS CONTINUING THROUGH THE REST OF THE DAY...IMPROVING
BEHIND COLD FRONT EARLY TOMORROW.
* VSBY GENERALLY 1-3SM...BUT POSSIBLY LESS THAN A QUARTER MILE IF
DENSE FOG WERE TO DEVELOP.
BMD
//DISCUSSION...UPDATED 18Z...
A WASHED OUT WARM FRONT IS LIFTING INTO ILLINOIS EARLY THIS
AFTERNOON...WITH A BROAD DEWPOINT GRADIENT SPREADING NORTHWARD
ACROSS THE STATE. NORTH OF THE FRONT...CIGS ARE GENERALLY BETWEEN
002 AND 005 WHILE VSBY IS MORE VARIABLE...BUT NUMEROUS 1-3SM REPORTS
ARE NOTED ACROSS FAR NORTHERN ILLINOIS DUE TO FOG/MIST. AS LOW
PRESSURE TRACKS FROM EASTERN NEBRASKA THIS AFTERNOON INTO SOUTHERN
WISCONSIN LATER THIS EVENING...EXPECT NORTHWARD MOISTURE TRANSPORT TO
CONTINUE WITH DEWPOINTS RISING INTO THE MID OR UPPER 30S OVER THE
SNOWPACK. THE IMMEDIATE CONCERN HERE IS FOR THE POTENTIAL OF DENSE
FOG DEVELOPING...WITH MET GUIDANCE INDICATING VSBY TANKING THIS
AFTERNOON. FEEL GUIDANCE MAY BE HITTING THIS TOO HARD THOUGH GIVEN
THE BROAD TD GRADIENT...AND WILL LEAN TOWARDS A MORE OPTIMISTIC VSBY
FORECAST...ADMITTEDLY WITH LOW CONFIDENCE CONSIDERING THE MORE
WIDESPREAD 1/4 TO 1/2 SM VSBY IMMEDIATELY AHEAD OF THE LOW.
SHOWERS WILL OVERSPREAD THE AREA THIS AFTERNOON AS A POTENT UPPER
WAVE LIFTS ACROSS THE REGION. MID LEVEL LAPSE RATES MAY BE
SUFFICIENTLY STEEP ENOUGH TO SUPPORT EMBEDDED THUNDERSTORMS AS FAR
NORTH AS THE CHICAGO TERMINALS...HOWEVER FELL BEST CHANCES FOR FOR
THUNDER WILL STAY SOUTH OF THE I-80 CORRIDOR. RAIN IS EXPECTED TO BE
MODERATE WITH BRIEFLY HEAVY SHOWERS POSSIBLE. DEEPER MOISTURE WILL
PUSH OUT OF THE AREA MID TO LATE THIS EVENING WITH LINGERING DRIZZLE
POSSIBLE INTO THE EARLY OVERNIGHT HOURS. FEEL THAT ONCE THE RAIN
STOPS THIS EVENING...THIS WILL BE THE PERIOD THAT MAY HAVE TO BE
MONITORED MOST CLOSELY FOR FOG DEVELOPING. DEWPOINTS SHOULD BE
CLIMBING INTO THE 35-37 RANGE BY THIS POINT WHICH ASSUMING THERE IS
STILL SOME SNOW ON THE GROUND WOULD BE FAVORABLE FOR FOG TO INCREASE
IN THICKNESS. UNFORTUNATELY...MET/MAV GUIDANCE SHOWS THE
OPPOSITE...WITH IMPROVING VSBY TRENDS AFTER THE RAIN DEPARTS
OVERNIGHT...ONCE AGAIN RESULTING IN VERY LOW CONFIDENCE IN VSBY
FCST. WILL STICK WITH GOING VSBY TRENDS THIS PERIOD UNTIL HAVE
HIGHER CONFIDENCE IN A SOLUTION.
A COLD FRONT WILL SWEEP ACROSS THE AREA EARLY SATURDAY. WHILE
NOTABLE DRYING OCCURS ALOFT...APPEARS WE MAY STICK FOR SEVERAL HOURS
WITH SOME POST FRONTAL STRATUS...AT LEAST UNTIL SATURDAY AFTERNOON
WHEN IT MAY FINALLY SCATTER OUT. VSBY SHOULD SHARPLY IMPROVE BEHIND
THE FRONT THOUGH WITH WINDS TURNING WESTERLY AND BECOMING
INCREASINGLY GUSTY.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* VERY LOW CONFIDENCE IN VSBY TRENDS TODAY AND TONIGHT.
* HIGH CONFIDENCE IN IFR OR LOWER CIGS THROUGH THE OVERNIGHT HOURS.
* MEDIUM-HIGH CONFIDENCE IN RAIN TIMING.
* MEDIUM-HIGH CONFIDENCE IN WIND DIRECTION...MEDIUM CONFIDENCE IN
WIND SPEED.
BMD
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT...VFR PROBABLE.
SUNDAY...STRONG SOUTH WINDS...LLWS POSSIBLE AFTERNOON/EARLY
EVENING. VFR PROBABLE.
MONDAY...VFR.
TUESDAY...CHANCE OF SNOW/IFR.
WEDNESDAY AND THURSDAY...VFR PROBABLE.
IZZI
&&
.MARINE...
417 AM CST
SOUTH WINDS WILL RAMP UP TODAY IN ADVANCE OF DEVELOPING LOW PRESSURE
OVER THE CORNBELT THIS AFTERNOON. THIS LOW WILL TRACK ACROSS
NORTHERN LM LATE TONIGHT/EARLY SAT AM ON ITS WAY TO QUEBEC BY
SUNDAY. WEAK RIDGE TRAVERSES THE LAKE SAT NIGHT BEFORE A VERY STRONG
LOW RACES EAST ACROSS SOUTHERN CANADA SUNDAY RESULTING IN WHAT LOOKS
TO BE A PRETTY GOOD SHOT OF SOUTH GALES SUNDAY INTO SUNDAY EVENING.
MODELS STRONGLY DIVERGE ON STRENGTH AND TIMING OF NORTHWEST FLOW
DISTURBANCES IN THE TUES/WED TIME RANGE RESULTING IN LOW CONFIDENCE
FORECAST.
IZZI
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1140 AM CST FRI JAN 10 2014
.DISCUSSION...
1114 AM CST
HAVE SPENT THE MORNING EXAMINING THE POTENTIAL FOR DENSE FOG AND
THE POSSIBLE NEED FOR AN ADVISORY LATER TODAY...THE APPROACHING
THUNDERSTORMS IN WEST CENTRAL ILLINOIS...AND THE FLOOD POTENTIAL
GIVEN THE EXPECTED RAINFALL AND WARMING TEMPERATURES.
FOR THE NEAR TERM WE ELECTED TO CANCEL THE FREEZING FOG ADVISORY A
LITTLE EARLY AS TEMPERATURES IN MOST LOCATIONS HAVE RISEN ABOVE OR
VERY NEAR FREEZING. THE NEXT QUESTION WOULD BE WHETHER DENSE FOG
DEVELOPS IN THE SATURATED SURFACE LAYER MOVING IN OVER THE
SNOWPACK WITH INCREASING DEWPOINTS. OBSERVATIONS JUST UPSTREAM OF
THE AREA ARE SHOWING VSBYS AT WORST AROUND 1 MILE...BUT FARTHER
UPSTREAM TOWARD THE APPROACHING LOW CENTER THEY ARE MORE COMMONLY
AROUND 1/4 TO 1/2 MILE. SO FOR THE AFTERNOON AM NOT ANTICIPATING
THE NEED FOR FOG HEADLINES...BUT WILL REEVALUATE LATER TODAY IN
CASE SOMETHING MAY BE NEEDED THIS EVENING OR OVERNIGHT.
THE AREA OF THUNDERSTORMS AROUND QUINCY AND SOUTHWEST TOWARD
JOPLIN MISSOURI IS WELL CORRELATED WITH AN AREA OF ENHANCED LOW
LEVEL MOISTURE FLUX SHOWN IN THE RAP MODEL EAST OF THE
APPROACHING LOW PRESSURE CENTER. AS THE AFTERNOON EVOLVES AND THE
LOW LIFTS NORTHEAST...THE RAP MODEL INCREASES THE MOISTURE FLUX
OVER CENTRAL AND NORTHERN ILLINOIS. AREAS OF STEEPER LAPSE RATES
ARE ALSO SEEN IN NAM/GFS SOUNDINGS FOR THE AFTERNOON AND EVENING
TIMEFRAME. WILL UPDATE FCST GRIDS TO INTRODUCE A SLIGHT CHANCE OF
TSTMS MAINLY FOR THE SOUTHERN HALF OF THE AREA.
AS FOR FLOODING POTENTIAL...AM NOT PLANNING ON ANY FLOOD WATCH
HEADLINES AT THIS TIME GIVEN SO MANY VARIABLES...INCLUDING
LOCATION OF HEAVIER RAIN AMOUNTS...DEGREE TO WHICH THE SNOWPACK
WOULD SPONGE UP THE RAIN...EVOLUTION OF DEWPOINT
TEMPERATURES...AND THE BEHAVIOR OF ICE ON THE RIVERS AND STREAMS.
THE BEST POTENTIAL FOR MAINSTEM FLOODING APPEARS TO BE ALONG THE
KANKAKEE WHERE A FLOOD WARNING HAS BEEN ISSUED FOR ANTICIPATED MINOR
FLOODING. THIS RIVER ALREADY HAD QUITE A BIT OF WATER IN IT...BUT
THE OTHERS HAVE A LITTLE MORE ROOM TO HANDLE THE RUNOFF.
LENNING
&&
.PREV DISCUSSION...
338 AM CST
SHORT TERM...TODAY THROUGH SUNDAY NIGHT
TODAY/TONIGHT...
MULTIPLE CONCERNS IN THE NEAR TERM TODAY...INCLUDING DENSE
FOG...FREEZING DRIZZLE/RAIN AND THEN RAIN AND MELTING SNOW LATER
TODAY INTO THIS EVENING.
GRADUAL INCREASE IN SURFACE MOISTURE OVER DEEP SNOW PACK HAS
RESULTED IN FOG DEVELOPMENT EARLY THIS MORNING...WITH MULTIPLE
LOCATIONS AOB 1/2 MILE. FOG HAS BEEN MOST DENSE ALONG/WEST OF A LINE
FROM UGN TO VYS. WILL LIKELY NEED A DENSE FOG ADVISORY ADVISORY OR
FREEZING FOG ADVISORY FOR MOST IF NOT ALL IF THIS AREA FOR PART OF
TODAY UNTIL TEMPERATURES WARM AND STEADIER PRECIP ARRIVES
LATER...WITH CONTINUED MOISTURE INCREASE AND SATURATION OF SURFACE
LAYER OVER SNOWPACK.
WEAK ASCENT EARLY TO MID MORNING IN SOUTHWEST FLOW ALOFT WITH
INCOMING SHORTWAVE ENERGY COULD ALSO RESULT IN PATCHY FREEZING
DRIZZLE...BEST CHANCE OF SEEING MEASURABLE ZR- IN WESTERN HALF OF
CWA...BUT CONFIDENCE IS LOW IN ICE ACCUMULATIONS.
TEMPERATURE TRENDS WILL BE KEY TO EXTENT OF PROBLEMS TODAY WITH
FREEZING RAIN/DRIZZLE. UNTIL BETTER DEWPOINTS SOUTH OF OH RIVER
SURGE NORTHWARD...TEMPERATURES SHOULD VERY SLOWLY CLIMB. GUIDANCE IS
ALREADY A BIT TOO LOW ON CURRENT TEMPERATURES...SO THINK THAT ONCE
STRONGER MIDLEVEL WAVE/MOIST TRANSPORT ARRIVES EARLY TO MID
AFTERNOON...MOST IF NOT ALL AREAS SHOULD BE ABOVE FREEZING AND LIMIT
FREEZING RAIN THREAT. BIGGEST CONCERN IS FOR WI BORDER AREAS TO WARM
A BIT SLOWER AND THUS SEE A FEW HRS OF FREEZING RAIN BEFORE CHANGING
TO PLAIN RAIN. HAVE BETTER CONFIDENCE ROUGHLY SOUTH OF I-90 THAT
PLAIN RAIN WILL BE PREDOMINANT P-TYPE.
REGARDING RAIN AND SNOWMELT...STOUT MIDLEVEL WAVE AND ASSOCIATED
SURFACE LOW TRACKING WEST OF CWA WILL AIM PLUME OF 2-3 SD ABOVE
NORMAL/A BIT OVER .75 INCH PWAT/INTO AREA BY THIS EVENING. UNTIL
DRYSLOT ARRIVES LATE IN THE EVENING INTO THE OVERNIGHT AND SHUTS OFF
STEADY RAIN...THERE COULD BE PERIODS OF MODERATE RAIN. LOCAL WRF
GUIDANCE IS MUCH MORE BULLISH ON HOW WARM TEMPERATURES ARE THIS
EVENING/MID 40S FOR SOUTHEASTERN HALF OF CWA/WITH HEAVIEST RAINFALL.
IF TEMPERATURES ARE WARMER THAN UPPER 30S/LOW 40S/THIS COULD ENABLE
MORE RAPID SNOWMELT AND HEIGHTEN FLOODING CONCERNS. DO NOT HAVE
ENOUGH CONFIDENCE TO ISSUE ANY FLOOD WATCHES...BUT WILL CONTINUE
WITH PREVIOUSLY ISSUED ESF TO HIGHLIGHT FLOODING
POTENTIAL...INCLUDING BREAK UP ICE JAMS ON AREA RIVERS.
SATURDAY THROUGH SUNDAY NIGHT...
LOWERED POPS SATURDAY MORNING...WITH ONLY CHANCE POPS FOR FAR NORTH
AS DEFORMATION AXIS OF STRENGTHENING SURFACE AND UPPER SYSTEM OVER
THE REGION LOOKS TO AT BEST GRAZE THE FAR NORTH. MORE LIKELY
SCENARIO IS FOR DEFORMATION TO IMPACT CENTRAL WISCONSIN.
THEREFORE...WHILE THERMAL PROFILES WILL BECOME COLD ENOUGH...AT BEST
WOULD ONLY EXPECT LIGHT SNOW AND NO ACCUM IN FAR NORTHERN CWA. COOL
ADVECTION THROUGH THE DAY WILL RESULT IN ONLY A FEW DEGREE TEMP
CLIMB IN AFTERNOON FROM MORNING LOWS IN LOW-MID 30S.
THERE SHOULD BE ENOUGH TIME FOR WET SURFACES TO DRY OFF TO PRECLUDE
A BIG THREAT OF ICY SPOTS ON ROAD SURFACES SATURDAY NIGHT AS
TEMPERATURES FALL INTO THE TEENS AND 20S. RAPID WARM ADVECTION
PATTERN THEN SETS UP ON SUNDAY AS H85 TEMPS WARM BACK UP TO +6 TO
+8C. A LOOK AT FORECAST SOUNDINGS INDICATES THAT GLOBAL MODELS MAY
BE STRUGGLING WITH LOWER LEVEL THERMAL PROFILES DUE TO TRYING TO
RESOLVE EXISTING SNOWPACK. AS A RESULT...925 MB TEMPS ON HIGHER RES
NAM OF +6 TO +8C MAY BE THE BETTER ROUTE THAN LOW POSITIVE SINGLE
DIGITS. ASSUMING THAT MOST OF THE AREA STILL HAS AT LEAST 1 INCH OF
SNOW ON THE GROUND...WARMING POTENTIAL WILL BE LESS THAN WITHOUT
SNOW. HOWEVER...SOUTHERN EDGE OF SNOWPACK WILL LIKELY BE QUICKLY
ERODING...WITH MID 40S IF NOT WARMER POSSIBLE IN SOUTHERN CWA. ONLY
AREAS LIMITED TO THE UPPER 30S MAY BE THE FAR NORTHWEST. A COLD
FRONT TRAILING FROM CLIPPER SYSTEM OVER NORTHERN LAKES WILL THEN
SWING THROUGH CWA SUNDAY NIGHT LIKELY DRY EXCEPT PERHAPS FAR NORTH
WHERE SLIGHT POPS WERE MAINTAINED.
LONG TERM...MONDAY THROUGH THURSDAY...
OVERALL UPPER PATTERN WILL REALIGN TO A RIDGE IN THE WEST/TROUGH IN
THE EAST...WHICH IS KNOWN AS A POSITIVE PNA PATTERN. THIS IS
TYPICALLY A COLDER BUT FAIRLY DRY SET-UP FOR THE LOCAL AREA. WILL
NEED TO WATCH FOR CLIPPER TYPE SYSTEMS IN NORTHWEST FLOW ALOFT.
GUIDANCE BECOMES SPLIT ON WHETHER TO FOCUS MORE ENERGY IN SOUTHERN
STREAM SYSTEM OR NORTHERN VORT ON MONDAY NIGHT INTO TUESDAY. IN
PARTICULAR...ECMWF IS OF MOST INTEREST WITH ITS STRONGER SOUTHERN
STREAM WAVE. IF A QUICKER PHASE OCCURS WITH NORTHERN BRANCH
FEATURE...MORE THAN SOUTHEAST CWA COULD BE IMPACTED BY A SYSTEM IN
THIS TIMEFRAME. OPERATIONAL GFS DOES NOT SEEM TO HAVE MUCH ENSEMBLE
SUPPORT WITH ITS UNUSUALLY STRONG CLIPPER SYSTEM TRACKING ACROSS THE
AREA ON MONDAY NIGHT. HAVE SLIGHT TO LOW POPS MONDAY NIGHT INTO
TUESDAY...WITH THE POSSIBILITY THEN OF MORE CLIPPER ACITIVITY LATER
NEXT WEEK. IN BETWEEN LOOKS TO BE PRIMARILY DRY...WITH LAKE EFFECT
SNOW FOCUSED EAST OF FAR EASTERN CWA. THE CORE OF THE COLDEST AIR
DURING THIS TIME WILL REMAIN NORTH OF US WITH POLAR VORTEX OVER
HUDSON BAY...BUT OTHER THAN A BRIEF WARM-UP ON
THURSDAY...TEMPERATURES ARE LIKELY TO AVERAGE BELOW NORMAL THROUGH
EXTENDED AND BEYOND.
RC
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* LIFR CONDITIONS GENERALLY EXPECTED TO PERSIST TODAY
* DENSE FOG POSSIBLE THIS AFTERNOON AND EVENING.
* RAIN DEVELOPS LATE THIS AFTERNOON AND CONTINUES THROUGH MID
EVENING...SOME MINOR IMPROVEMENTS TO CIGS/VSBY PSBL WITH THE
RAIN
IZZI
//DISCUSSION...UPDATED 12Z...
FAIRLY MOIST AND MILD AIR CONTINUES TO TRY AND STREAM NORTH INTO
THE AREA OVER THE DENSE COLD SNOW COVER RESULTING IN LOW CLOUDS
AND FOG. GENERALLY SPEAKING...ALL SIGNS WOULD TEND TO POINT TO
CONDITIONS NOT IMPROVING MUCH TODAY AND POSSIBLY DETERIORATING AS
HIGHER DEWPOINTS MOVE IN LATER THIS MORNING INTO THE AFTERNOON.
HAVE SEEN A FEW SITES POP UP WITH HIGHER CIGS/VSBY RECENTLY AND
STRUGGLING TO FIND A GOOD METEOROLOGICAL REASONING FOR THAT SO
FOR THE TAFS DECIDED TO TREAT THAT AS A TEMPORARY CONDITIONS
RATHER THAN THE BEGINNING OF A TREND...THOUGH NO DOUBT THE CHANCE
OF THE DAY SHIFT HAVING TO CHASE TRENDS IS PRETTY HIGH TODAY.
STILL MOSTLY ERRING ON THE OPTIMISTIC SIDE TO PERHAPS MIDDLE OF
THE ROAD IN THE TAFS...THOUGH FINALLY THREW IN THE TOWEL AND
LOWERED MDW AS THEY HAVE BEEN REPORTING VSBY BELOW 1SM FOR HOURS
NOW WITHOUT SHOWING ANY SIGNS OF IMPROVEMENT. GUIDANCE WOULD
SUGGEST CONDITIONS WORSENING THIS AFTERNOON...THOUGH AM HOLDING
OUT SOME HOPE FOR A LITTLE BIT OF IMPROVEMENT WHEN THE STEADIER
RAIN ARRIVES TOWARD SUNSET. EXPECT IFR/LIFR TO CONTINUE THROUGH
MOST OF TONIGHT AS THE HIGH DEWPOINTS EAT AWAY AT THE SNOW
COVER...THOUGH WIND SHIFT TO WEST TOWARD SUNRISE SHOULD BRING IN A
BIT DRIER AIR AND OFFER UP A BETTER CHANCE TO RISE ABOVE IFR.
IZZI
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* LOW CONFIDENCE IN VSBY TRENDS
* HIGH CONFIDENCE IN IFR/LIFR CIGS THROUGH TONIGHT
* HIGH CONFIDENCE IN TIMING OF ONSET OF STEADIER RAIN +/- AN HOUR
OR SO
IZZI/BMD
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT...VFR PROBABLE.
SUNDAY...STRONG SOUTH WINDS...LLWS POSSIBLE AFTERNOON/EARLY
EVENING. VFR PROBABLE.
MONDAY...VFR.
TUESDAY...CHANCE OF SNOW/IFR.
WEDNESDAY AND THURSDAY...VFR PROBABLE.
IZZI
&&
.MARINE...
417 AM CST
SOUTH WINDS WILL RAMP UP TODAY IN ADVANCE OF DEVELOPING LOW PRESSURE
OVER THE CORNBELT THIS AFTERNOON. THIS LOW WILL TRACK ACROSS
NORTHERN LM LATE TONIGHT/EARLY SAT AM ON ITS WAY TO QUEBEC BY
SUNDAY. WEAK RIDGE TRAVERSES THE LAKE SAT NIGHT BEFORE A VERY STRONG
LOW RACES EAST ACROSS SOUTHERN CANADA SUNDAY RESULTING IN WHAT LOOKS
TO BE A PRETTY GOOD SHOT OF SOUTH GALES SUNDAY INTO SUNDAY EVENING.
MODELS STRONGLY DIVERGE ON STRENGTH AND TIMING OF NORTHWEST FLOW
DISTURBANCES IN THE TUES/WED TIME RANGE RESULTING IN LOW CONFIDENCE
FORECAST.
IZZI
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
332 AM CST FRI JAN 10 2014
.DISCUSSION...
816 PM CST
RADAR MOSAIC SHOWS CONTINUED LIGHT SNOW ACROSS MUCH OF THE EASTERN
CWA FROM NEAR PONTIAC NORTHEAST TO THE NORTHERN CHICAGO METRO.
WARM ASCENT CONTINUES ABOVE WITH ADDITIONAL ASCENT LOOKING TO BE
PROVIDED BY AN ELONGATED AREA OF CYCLONIC VORTICITY TRAILING A
SHORTWAVE DEPARTING TO THE EAST. ASCENT AHEAD OF SUBTLE WAVE
MOVING INTO WEST CENTRAL IL MAY ALSO BE PLAYING A ROLE. RECENT
AIRCRAFT SOUNDINGS AND FORECAST RAP SOUNDINGS SHOW THE TOP OF THE
MOIST LAYER NEAR -10C SUPPORTING NEEDLE AND COLUMN LIKE CRYSTALS.
MAINLY NEEDLES APPEAR TO BE FALLING AT THE OFFICE AT THE MOMENT.
THIS FINER CRYSTAL STRUCTURE SUGGESTS MINIMAL ACCUMULATION BUT A
COATING TO A TENTH OR TWO IS IS LIKELY UNTIL THIS BETTER ORGANIZED
SNOW BAND DEPARTS...WHICH SHOULD OCCUR IN THE NEXT FEW HOURS. HAVE
INCREASED POPS FOR THE NEXT FEW HOURS AND ADDED SOME MINIMAL
ACCUMULATION TO THE GRIDS. GIVEN THE SNOW FALLING...FREEZING
DRIZZLE LOOKS TO HOLD OFF UNTIL LATER THIS EVENING AS THE SNOW
DEPARTS AND COLUMN MOISTURE BECOMES MORE SHALLOW LEADING TO A
LOWER PERCENTAGE OF ICE IN THE CLOUDS...BUT THIS STILL LOOKS TO BE
PATCHY IN COVERAGE IF IT OCCURS. OTHERWISE VSBY LOOKS TO BE
REDUCED IN MIST WHICH MAY BE ENOUGH TO PROVIDE SOME SLICK SPOTS ON
SOLID SURFACES INTO THE OVERNIGHT BUT DENSE FREEZING/ACCUMULATING
FOG IS NOT EXPECTED AT THIS TIME.
MDB
//PREV DISCUSSION...
339 PM CST
MAIN FORECAST CHALLENGES/CONCERNS ARE WITH LIGHT SNOW OR LIGHT
FREEZING DRIZZLE POTENTIAL LINGERING INTO THIS EVENING...POTENTIAL
FOR FREEZING RAIN OR FREEZING DRIZZLE ONCE AGAIN FRIDAY
MORNING...AND THEN A CONTINUED WARM UP WITH ALL RAIN LIKELY FRIDAY
AFTERNOON THROUGH EARLY SATURDAY MORNING.
CONCERNS IN THE NEAR TERM REMAIN WITH ONGOING LIGHT SNOW...AS WELL
AS A TRANSITION TO EITHER LIGHT SNOW OR LIGHT FREEZING DRIZZLE
LATE THIS AFTERNOON INTO THE EARLY EVENING. LATEST RADAR IMAGERY
DEPICTING ONLY LIGHT RETURNS ON RADAR...WITH SURFACE OBS STILL
REPORTING ALL SNOW ACROSS THE AREA. THIS SNOW HAS BEEN IN RESPONSE
TO A SHORT WAVE TROUGH LIFTING EAST/NORTHEAST ACROSS THE
REGION...AS WELL AS A WAA WING SWINGING A SWATH PRECIP ACROSS
MAINLY THE SOUTHEAST TWO THIRDS OF THE CWA. AN OVERALL DIMINISHING
TREND AS BEEN OBSERVED THIS PAST HOUR AND EXPECT THIS TO CONTINUE
LATE THIS AFTERNOON...AS WITH THIS WEAK FORCING FURTHER WEAKENING
WHILE SHIFTING EAST OUT OF THE AREA. SNOWFALL THIS PAST AFTERNOON
HAS BEEN FROM A DUSTING UP TO A HALF INCH...VIA REPORTS FROM
FACEBOOK/TWITTER...AND WOULD EXPECT AT MOST A COUPLE OF TENTHS OF
AN INCH OF ADDITIONAL SNOWFALL THIS AFTERNOON. ALTHOUGH THERE
STILL REMAINS CONCERNS FOR A TRANSITION OVER TO FREEZING DRIZZLE
LATE THIS AFTERNOON...CONCERNS FOR ANY LONG DURATION/PREVAILING
FREEZING DRIZZLE ARE BEGINNING TO LESSEN. AS DEEPER MOISTURE
CONTINUES TO STREAM OVER THE REGION...PRECIP TYPE REMAINS ALL SNOW
AT THIS HOUR. THROUGH THE 00Z TIME FRAME IT DOES APPEAR THAT THIS
DEEPER MOISTURE IS LOSS...BUT STILL ON THE LOWER THRESHOLD FOR
CRYSTALS TO BE PRESENT AND THUS FOR SNOW FOR MOST AREAS. 00Z AND
BEYOND...CONTINUED LOSS OF THIS MOISTURE WILL OCCUR AND ITS DURING
THIS TIME FRAME THAT I THINK THERE WILL BE THE POTENTIAL FOR LIGHT
FREEZING DRIZZLE. ALTHOUGH...LATEST GUIDANCE IN FAIR AGREEMENT
WITH THE BETTER LIFT/OMEGA IN THE LOWER LEVEL MOIST LAYER TO BEGIN
SHIFTING EAST OF THE CWA ALSO DURING THIS TIME. SO DO FEEL THAT
THERE IS STILL POTENTIAL FOR LIGHT FREEZING DRIZZLE THIS
EVENING...THINK ITS A SMALL WINDOW FOR THIS OPPORTUNITY BEFORE ALL
LIFT DEPARTS. HAVE TRENDED THE GRIDS THIS WAY FOR THIS
EVENING...BUT DID LEAVE PATCHY FREEZING DRIZZLE IN OVERNIGHT FOR
MOST AREAS. LATEST SATELLITE IMAGERY/OBSERVATIONS DEPICTING LOW
LEVEL MOISTURE STILL WORKING ITS WAY NORTH ACROSS THE REGION. IN
THE HIGHLY SATURATED LOWER LEVELS...CONCERNED THAT THIS PATCHY
LIGHT FREEZING DRIZZLE COULD STILL OCCUR. AM NOT EXPECTING MUCH IN
TERMS OF ICE ACCUMULATION...BUT CANNOT RULE OUT ISOLATED SLIPPERY
CONDITIONS TO DEVELOP. TEMPERATURES LATE THIS AFTERNOON/EARLY
EVENING WILL BE OUR LOWS FOR THE NIGHT...AS STRONG WAA CONTINUES
TONIGHT WITH RISING TEMPS EXPECTED TONIGHT INTO FRIDAY MORNING.
DESPITE WARMING TEMPS THROUGH EARLY FRIDAY MORNING...SURFACE TEMPS
WILL STILL BE AT OR JUST BELOW FREEZING THROUGH MID LATE MORNING.
ASCENT WILL BE ON THE INCREASE ON FRIDAY AS A STRONG MID/UPPER
LEVEL TROUGH SHIFTS EAST ACROSS THE CENTRAL PLAINS. WITH THERMAL
PROFILES DURING THIS TIME SUPPORTIVE OF ALL LIQUID...AM STILL
CONCERNED THAT A BRIEF PERIOD OF FREEZING RAIN COULD OCCUR. THE
QUESTIONS WILL BE IF FORCING/PRECIP RETURNS SOON ENOUGH BEFORE
TEMPS RISE ABOVE FREEZING. ALTHOUGH DO FEEL THAT THIS BETTER
PRECIP AXIS WONT ARRIVE UNTIL TEMPS RISE AT OR ABOVE FREEZING BY
THIS MID LATE MORNING PERIOD. IF FREEZING RAIN DOES OCCUR...IT
SHOULD BE A NARROW TIME FRAME WITH THE WEST/SOUTHWEST AREAS IN A
MORE PREFERRED LOCATION IN THE MORNING...AND POSSIBLY FOR THE FAR
NORTHWEST CWA THROUGH MID DAY. CONTINUED WARMING CONTINUES INTO
THE AFTERNOON WITH ALL RAIN THEN OCCURRING FRIDAY AFTERNOON INTO
FRIDAY NIGHT FOR ALL AREAS...WITH THREE QUARTERS OF AN INCH TO ONE
INCH POSSIBLE AREA WIDE. LATEST TRENDS HAVE BEEN FOR A QUICKER
TRANSITION BACK TOWARDS SNOW LATE FRIDAY NIGHT INTO EARLY SATURDAY
MORNING...WITH ALL SNOW LIKELY THEN SATURDAY BEFORE THIS PRECIP
EXITS. ALTHOUGH ANY LINGERING SNOW SHOULD BE ON THE LIGHT
SIDE...AND DONT ANTICIPATE ANY ADDITIONAL SNOW ACCUMULATION.
RODRIGUEZ
&&
.HYDROLOGY...
339 PM CST
ALSO OF INTEREST THIS FORECAST CONTINUE TO BE WITH HYDROLOGIC
ISSUES...WITH A WARMER AND MORE MOIST AIR MASS MOVING NORTH ACROSS
THE REGION TONIGHT THROUGH FRIDAY. THIS WILL ALLOW FOR A
TRANSITION TO ALL RAIN BY MID DAY FRIDAY...CONTINUING INTO EARLY
SATURDAY MORNING. RAINFALL TOTALS OF THREE QUARTERS OF AN INCH TO
ONE INCH ARE POSSIBLE AREA WIDE FROM FRIDAY AFTERNOON THROUGH
EARLY SATURDAY MORNING. CONCERNS WITH THE WARM
UP...RAINFALL...FROZEN GROUND WITH CURRENT SNOWPACK IN PLACE COULD
ALL RESULT IN RISES IN AREA RIVERS/STREAMS/CREEKS AS WELL AS
POTENTIAL FOR FLOODING AND ICE JAM FLOODING. CONFIDENCE IS NOT TOO
HIGH WITH REGARDS TO THE EXTENT OF THE
SNOWMELT...NONETHELESS...THE PREVIOUSLY MENTIONED CONCERNS WARRANT
CONTINUED CLOSE MONITOR OF THIS SITUATION INTO THE WEEKEND. FOR
MORE INFORMATION ON THIS FLOOD POTENTIAL SEE THE HYDROLOGIC
OUTLOOK ISSUED EARLIER THIS AFTERNOON...ESF.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 09Z...
* LIFR CIGS POSSIBLY DROPPING TO VLIFR THIS MORNING
* SMALL CHANCE OF -FZDZ THIS MORNING
* DENSE FOG POSSIBLE THIS MORNING INTO THE EARLY AFTERNOON
* RAIN DEVELOPS LATE THIS AFTERNOON AND CONTINUES THROUGH MID
EVENING...SOME MINOR IMPROVEMENTS TO CIGS/VSBY LIKELY WITH THE
RAIN
IZZI
//DISCUSSION...UPDATED 09Z...
BIGGEST CHANGE FROM THE 06Z TAFS WAS TO BRING CONDITIONS. CIGS AND
VSBYS HAVE TRENDED SHARPLY DOWNWARD THE PAST COUPLE HOURS AND CANT
THINK OF ANY GOOD REASON FOR ANY SUSTAINED IMPROVEMENT UNTIL
STEADY RAIN DEVELOPS LATE THIS AFTERNOON. CONTINUE TO ERR ON THE
OPTIMISTIC SIDE WITH REGARDS TO VSBY...BUT STILL THINK THERE IS A
PRETTY GOOD CHANCE THAT MDW WILL BE DROPPING BELOW RVR MINIMUMS
THIS MORNING AND REMAIN THERE INTO THE AFTERNOON AS PROGRESSIVELY
HIGHER DEWPOINTS ARE ADVECTED NORTH OVER THE DEEP SNOW PACK.
IZZI
UPDATED 06Z...
WARM FRONT WILL LIFT NORTHWARD ACROSS THE REGION FRIDAY WITH A
PRETTY STRONG SURGE OF MOIST AND FAIRLY MILD AIR MOVING UP INTO
THE AREA OVER A DENSE SNOW PACK. ALREADY HAVE WIDESPREAD LIFR CIGS
UPSTREAM HEADING INTO THE AREA AND ANTICIPATE CONDITIONS TO LIKELY
TO CONTINUE TO DETERIORATE THROUGH THE NIGHT AND PROBABLY FRIDAY
MORNING AS WELL. SUSPECT THAT IF ANYTHING THESE TAFS ARE
OPTIMISTIC WITH REGARDS TO CIGS/VSBY WITH AT LEAST SOME POTENTIAL
FOR DENSE FOG AND VV001 DEVELOPING FRIDAY MORNING...BUT RELUCTANT
TO TREND THAT LOW YET DUE TO LACK OF CONFIDENCE. ALSO CONCERNED
THAT SOME FZDZ COULD DEVELOP FOR A TIME FRIDAY MORNING BEFORE
TEMPERATURES RISE ABOVE FREEZING...BUT FORECAST SOUNDINGS SUGGEST
FAIRLY SHALLOW MOIST LAYER UNTIL CLOSER TO MIDDAY BY WHICH TIME
TEMPS SHOULD BE ABOVE FREEZING. IF DZ MATERIALIZES SOONER THAN
EXPECTED THEN A PERIOD OF FZDZ WOULD BE POSSIBLE FRIDAY MORNING.
STEADY RAIN DEVELOPS LATE FRIDAY AFTERNOON LIKELY MIXING OUT THE
LOWEST CIGS WITH SOME IMPROVEMENT IN CONDITIONS AT THAT TIME...BUT
LIKELY TO REMAIN IFR. RAIN SHOULD TAPER OFF TO MORE OCNL -SHRA OR
-DZ LATER FRIDAY EVENING INTO THE OVERNIGHT WITH IFR PROBABLY
CONTINUING.
IZZI
//ORD AND MDW CONFIDENCE...UPDATED 09Z...
* HIGH CONFIDENCE IN LIFR OR LOWER CONDITIONS THROUGH EARLY THIS
AFTERNOON
* LOW CONFIDENCE IN POTENTIAL FOR VLIFR IN DENSE FOG THIS MORNING
* HIGH CONFIDENCE IN TIMING OF ONSET OF STEADIER RAIN +/- AN HOUR
OR SO
* LOW CONFIDENCE IN POTENTIAL FOR FZDZ THIS MORNING
IZZI
//OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z...
00Z...
SATURDAY...GUSTY WEST WINDS WITH A CHANCE OF -SN WITH IFR/MVFR
POSSIBLE EARLY. VFR/WX NIL OVERNIGHT.
SUNDAY...GUSTY SOUTH WINDS. VFR/WX NIL EARLY. SLIGHT CHANCE OF
RAIN OR SNOW WITH MVFR POSSIBLE OVERNIGHT.
MONDAY...VFR/WX NIL.
TUESDAY...SLIGHT CHANCE OF SNOW. MVFR POSSIBLE.
WEDNESDAY...VFR/WX NIL.
KJB
&&
.MARINE...
219 PM CST
BROAD SURFACE RIDGE ALONG THE EASTERN SEABOARD STRETCHES FROM QUEBEC
SOUTH THROUGH THE CAROLINAS...WITH AN INFLUENCING REMAINING ACROSS
THE WESTERN GREAT LAKES THIS AFTERNOON. THE LARGEST INFLUENCE HAS
BEEN THE LACK OF A GRADIENT...WHICH HAS RESULTED IN WINDS BEING MUCH
LIGHTER THAN EARLIER ANTICIPATED. THUS HAVE SLOWED THE WIND SPEEDS
DOWN...AND ALSO HAS RESULTED IN WINDS REMAINING MORE SOUTHEASTERLY.
A BOUNDARY WAS LIFTING NORTH ACROSS THE OHIO VALLEY...AND WILL
LIKELY REACH THE SOUTHERN PORTIONS OF THE LAKE OVERNIGHT THEN ALLOW
WINDS TO TURN MORE SOUTHERLY FOR THE LAKE.
OVERNIGHT INTO FRIDAY GUIDANCE CONTINUES TO SUGGEST THE LACK OF A
GRADIENT WILL REMAIN WEST OF LAKE MICHIGAN...THEN THE CHANNEL OF
BETTER WINDS WILL EVENTUALLY SLIDE EAST/SOUTHEAST ACROSS THE LAKE
FRIDAY AFTERNOON/EVENING. SFC FLOW WILL REMAIN SOUTHERLY...WITH
SPEEDS GENERALLY AROUND 20 TO 30 KT. AT THIS TIME IT APPEARS
HAZARDOUS WINDS FOR SMALL CRAFT WILL DEVELOP AROUND THIS TIME AS
WELL.
THEN THE FOCUS FOR THE WEEKEND WILL BE ON A DEVELOPING LOW PRESSURE
SYSTEM THAT IS EXPECTED TO DEVELOP ACROSS THE SOUTHERN
PLAINS...WHICH WILL EVENTUALLY LIFT NORTHEAST ACROSS LATE SATURDAY
MORNING. THE GRADIENT WILL TIGHTEN SATURDAY EVENING...POSSIBLY
BRINGING SOME OCCASIONAL GUSTS TO 30 KT. THEN THE GRADIENT BEGINS TO
SLACKEN OFF THROUGH EARLY SUNDAY. YET ANOTHER LOW PRESSURE SYSTEM IS
EXPECTED TO SLIDE EAST ACROSS THE UPPER MIDWEST SUN AFTN...WITH THE
GRADIENT TIGHTENING YET AGAIN FOR LAKE MICHIGAN. CURRENT FORECAST
GUIDANCE INDICATES THE POSSIBILITY OF OCCASIONAL GALE FORCE GUSTS
FOR THE OPEN WATERS SUN LATE AFTN/EVE.
THE PATTERN REMAINS RELATIVELY ACTIVE FOR EARLY NEXT WEEK...WITH
ANOTHER LOW PRESSURE SYSTEM POISED TO SLIDE SOUTHEAST FROM THE UPPER
MIDWEST INTO THE GREAT LAKES. THE GRADIENT WILL ONCE AGAIN
TIGHTEN...WITH WINDS EVENTUALLY TURNING WEST/NORTHWESTERLY TUE
NGT/WED.
THE AMOUNT OF ICE REMAINS HIGH ACROSS NEARSHORE WATERS AS SEEN IN
WEBCAMS AND SATELLITE IMAGERY. THUS WAVES WILL BE OMITTED FROM THE
NEARSHORE FORECAST.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1137 PM CST THU JAN 9 2014
.DISCUSSION...
816 PM CST
RADAR MOSAIC SHOWS CONTINUED LIGHT SNOW ACROSS MUCH OF THE EASTERN
CWA FROM NEAR PONTIAC NORTHEAST TO THE NORTHERN CHICAGO METRO.
WARM ASCENT CONTINUES ABOVE WITH ADDITIONAL ASCENT LOOKING TO BE
PROVIDED BY AN ELONGATED AREA OF CYCLONIC VORTICITY TRAILING A
SHORTWAVE DEPARTING TO THE EAST. ASCENT AHEAD OF SUBTLE WAVE
MOVING INTO WEST CENTRAL IL MAY ALSO BE PLAYING A ROLE. RECENT
AIRCRAFT SOUNDINGS AND FORECAST RAP SOUNDINGS SHOW THE TOP OF THE
MOIST LAYER NEAR -10C SUPPORTING NEEDLE AND COLUMN LIKE CRYSTALS.
MAINLY NEEDLES APPEAR TO BE FALLING AT THE OFFICE AT THE MOMENT.
THIS FINER CRYSTAL STRUCTURE SUGGESTS MINIMAL ACCUMULATION BUT A
COATING TO A TENTH OR TWO IS IS LIKELY UNTIL THIS BETTER ORGANIZED
SNOW BAND DEPARTS...WHICH SHOULD OCCUR IN THE NEXT FEW HOURS. HAVE
INCREASED POPS FOR THE NEXT FEW HOURS AND ADDED SOME MINIMAL
ACCUMULATION TO THE GRIDS. GIVEN THE SNOW FALLING...FREEZING
DRIZZLE LOOKS TO HOLD OFF UNTIL LATER THIS EVENING AS THE SNOW
DEPARTS AND COLUMN MOISTURE BECOMES MORE SHALLOW LEADING TO A
LOWER PERCENTAGE OF ICE IN THE CLOUDS...BUT THIS STILL LOOKS TO BE
PATCHY IN COVERAGE IF IT OCCURS. OTHERWISE VSBY LOOKS TO BE
REDUCED IN MIST WHICH MAY BE ENOUGH TO PROVIDE SOME SLICK SPOTS ON
SOLID SURFACES INTO THE OVERNIGHT BUT DENSE FREEZING/ACCUMULATING
FOG IS NOT EXPECTED AT THIS TIME.
MDB
//PREV DISCUSSION...
339 PM CST
MAIN FORECAST CHALLENGES/CONCERNS ARE WITH LIGHT SNOW OR LIGHT
FREEZING DRIZZLE POTENTIAL LINGERING INTO THIS EVENING...POTENTIAL
FOR FREEZING RAIN OR FREEZING DRIZZLE ONCE AGAIN FRIDAY
MORNING...AND THEN A CONTINUED WARM UP WITH ALL RAIN LIKELY FRIDAY
AFTERNOON THROUGH EARLY SATURDAY MORNING.
CONCERNS IN THE NEAR TERM REMAIN WITH ONGOING LIGHT SNOW...AS WELL
AS A TRANSITION TO EITHER LIGHT SNOW OR LIGHT FREEZING DRIZZLE
LATE THIS AFTERNOON INTO THE EARLY EVENING. LATEST RADAR IMAGERY
DEPICTING ONLY LIGHT RETURNS ON RADAR...WITH SURFACE OBS STILL
REPORTING ALL SNOW ACROSS THE AREA. THIS SNOW HAS BEEN IN RESPONSE
TO A SHORT WAVE TROUGH LIFTING EAST/NORTHEAST ACROSS THE
REGION...AS WELL AS A WAA WING SWINGING A SWATH PRECIP ACROSS
MAINLY THE SOUTHEAST TWO THIRDS OF THE CWA. AN OVERALL DIMINISHING
TREND AS BEEN OBSERVED THIS PAST HOUR AND EXPECT THIS TO CONTINUE
LATE THIS AFTERNOON...AS WITH THIS WEAK FORCING FURTHER WEAKENING
WHILE SHIFTING EAST OUT OF THE AREA. SNOWFALL THIS PAST AFTERNOON
HAS BEEN FROM A DUSTING UP TO A HALF INCH...VIA REPORTS FROM
FACEBOOK/TWITTER...AND WOULD EXPECT AT MOST A COUPLE OF TENTHS OF
AN INCH OF ADDITIONAL SNOWFALL THIS AFTERNOON. ALTHOUGH THERE
STILL REMAINS CONCERNS FOR A TRANSITION OVER TO FREEZING DRIZZLE
LATE THIS AFTERNOON...CONCERNS FOR ANY LONG DURATION/PREVAILING
FREEZING DRIZZLE ARE BEGINNING TO LESSEN. AS DEEPER MOISTURE
CONTINUES TO STREAM OVER THE REGION...PRECIP TYPE REMAINS ALL SNOW
AT THIS HOUR. THROUGH THE 00Z TIME FRAME IT DOES APPEAR THAT THIS
DEEPER MOISTURE IS LOSS...BUT STILL ON THE LOWER THRESHOLD FOR
CRYSTALS TO BE PRESENT AND THUS FOR SNOW FOR MOST AREAS. 00Z AND
BEYOND...CONTINUED LOSS OF THIS MOISTURE WILL OCCUR AND ITS DURING
THIS TIME FRAME THAT I THINK THERE WILL BE THE POTENTIAL FOR LIGHT
FREEZING DRIZZLE. ALTHOUGH...LATEST GUIDANCE IN FAIR AGREEMENT
WITH THE BETTER LIFT/OMEGA IN THE LOWER LEVEL MOIST LAYER TO BEGIN
SHIFTING EAST OF THE CWA ALSO DURING THIS TIME. SO DO FEEL THAT
THERE IS STILL POTENTIAL FOR LIGHT FREEZING DRIZZLE THIS
EVENING...THINK ITS A SMALL WINDOW FOR THIS OPPORTUNITY BEFORE ALL
LIFT DEPARTS. HAVE TRENDED THE GRIDS THIS WAY FOR THIS
EVENING...BUT DID LEAVE PATCHY FREEZING DRIZZLE IN OVERNIGHT FOR
MOST AREAS. LATEST SATELLITE IMAGERY/OBSERVATIONS DEPICTING LOW
LEVEL MOISTURE STILL WORKING ITS WAY NORTH ACROSS THE REGION. IN
THE HIGHLY SATURATED LOWER LEVELS...CONCERNED THAT THIS PATCHY
LIGHT FREEZING DRIZZLE COULD STILL OCCUR. AM NOT EXPECTING MUCH IN
TERMS OF ICE ACCUMULATION...BUT CANNOT RULE OUT ISOLATED SLIPPERY
CONDITIONS TO DEVELOP. TEMPERATURES LATE THIS AFTERNOON/EARLY
EVENING WILL BE OUR LOWS FOR THE NIGHT...AS STRONG WAA CONTINUES
TONIGHT WITH RISING TEMPS EXPECTED TONIGHT INTO FRIDAY MORNING.
DESPITE WARMING TEMPS THROUGH EARLY FRIDAY MORNING...SURFACE TEMPS
WILL STILL BE AT OR JUST BELOW FREEZING THROUGH MID LATE MORNING.
ASCENT WILL BE ON THE INCREASE ON FRIDAY AS A STRONG MID/UPPER
LEVEL TROUGH SHIFTS EAST ACROSS THE CENTRAL PLAINS. WITH THERMAL
PROFILES DURING THIS TIME SUPPORTIVE OF ALL LIQUID...AM STILL
CONCERNED THAT A BRIEF PERIOD OF FREEZING RAIN COULD OCCUR. THE
QUESTIONS WILL BE IF FORCING/PRECIP RETURNS SOON ENOUGH BEFORE
TEMPS RISE ABOVE FREEZING. ALTHOUGH DO FEEL THAT THIS BETTER
PRECIP AXIS WONT ARRIVE UNTIL TEMPS RISE AT OR ABOVE FREEZING BY
THIS MID LATE MORNING PERIOD. IF FREEZING RAIN DOES OCCUR...IT
SHOULD BE A NARROW TIME FRAME WITH THE WEST/SOUTHWEST AREAS IN A
MORE PREFERRED LOCATION IN THE MORNING...AND POSSIBLY FOR THE FAR
NORTHWEST CWA THROUGH MID DAY. CONTINUED WARMING CONTINUES INTO
THE AFTERNOON WITH ALL RAIN THEN OCCURRING FRIDAY AFTERNOON INTO
FRIDAY NIGHT FOR ALL AREAS...WITH THREE QUARTERS OF AN INCH TO ONE
INCH POSSIBLE AREA WIDE. LATEST TRENDS HAVE BEEN FOR A QUICKER
TRANSITION BACK TOWARDS SNOW LATE FRIDAY NIGHT INTO EARLY SATURDAY
MORNING...WITH ALL SNOW LIKELY THEN SATURDAY BEFORE THIS PRECIP
EXITS. ALTHOUGH ANY LINGERING SNOW SHOULD BE ON THE LIGHT
SIDE...AND DONT ANTICIPATE ANY ADDITIONAL SNOW ACCUMULATION.
RODRIGUEZ
&&
.HYDROLOGY...
ALSO OF INTEREST THIS FORECAST CONTINUE TO BE WITH HYDROLOGIC
ISSUES...WITH A WARMER AND MORE MOIST AIR MASS MOVING NORTH ACROSS
THE REGION TONIGHT THROUGH FRIDAY. THIS WILL ALLOW FOR A
TRANSITION TO ALL RAIN BY MID DAY FRIDAY...CONTINUING INTO EARLY
SATURDAY MORNING. RAINFALL TOTALS OF THREE QUARTERS OF AN INCH TO
ONE INCH ARE POSSIBLE AREA WIDE FROM FRIDAY AFTERNOON THROUGH
EARLY SATURDAY MORNING. CONCERNS WITH THE WARM
UP...RAINFALL...FROZEN GROUND WITH CURRENT SNOWPACK IN PLACE COULD
ALL RESULT IN RISES IN AREA RIVERS/STREAMS/CREEKS AS WELL AS
POTENTIAL FOR FLOODING AND ICE JAM FLOODING. CONFIDENCE IS NOT TOO
HIGH WITH REGARDS TO THE EXTENT OF THE
SNOWMELT...NONETHELESS...THE PREVIOUSLY MENTIONED CONCERNS WARRANT
CONTINUED CLOSE MONITOR OF THIS SITUATION INTO THE WEEKEND. FOR
MORE INFORMATION ON THIS FLOOD POTENTIAL SEE THE HYDROLOGIC
OUTLOOK ISSUED EARLIER THIS AFTERNOON...ESF.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* IFR CIGS LIKELY TREND DOWN TO LIFR OVERNIGHT OR EARLY FRI AM
* VLIFR/DENSE FOG POSSIBLE FRIDAY MORNING INTO THE EARLY AFTERNOON
* RAIN DEVELOPS LATE FRIDAY AFTERNOON AND CONTINUES THROUGH MID
EVENING FRIDAY...SOME MINOR IMPROVEMENTS TO CIGS/VSBY LIKELY
WITH THE RAIN
IZZI
//DISCUSSION...UPDATED 06Z...
WARM FRONT WILL LIFT NORTHWARD ACROSS THE REGION FRIDAY WITH A
PRETTY STRONG SURGE OF MOIST AND FAIRLY MILD AIR MOVING UP INTO
THE AREA OVER A DENSE SNOW PACK. ALREADY HAVE WIDESPREAD LIFR CIGS
UPSTREAM HEADING INTO THE AREA AND ANTICIPATE CONDITIONS TO LIKELY
TO CONTINUE TO DETERIORATE THROUGH THE NIGHT AND PROBABLY FRIDAY
MORNING AS WELL. SUSPECT THAT IF ANYTHING THESE TAFS ARE
OPTIMISTIC WITH REGARDS TO CIGS/VSBY WITH AT LEAST SOME POTENTIAL
FOR DENSE FOG AND VV001 DEVELOPING FRIDAY MORNING...BUT RELUCTANT
TO TREND THAT LOW YET DUE TO LACK OF CONFIDENCE. ALSO CONCERNED
THAT SOME FZDZ COULD DEVELOP FOR A TIME FRIDAY MORNING BEFORE
TEMPERATURES RISE ABOVE FREEZING...BUT FORECAST SOUNDINGS SUGGEST
FAIRLY SHALLOW MOIST LAYER UNTIL CLOSER TO MIDDAY BY WHICH TIME
TEMPS SHOULD BE ABOVE FREEZING. IF DZ MATERIALIZES SOONER THAN
EXPECTED THEN A PERIOD OF FZDZ WOULD BE POSSIBLE FRIDAY MORNING.
STEADY RAIN DEVELOPS LATE FRIDAY AFTERNOON LIKELY MIXING OUT THE
LOWEST CIGS WITH SOME IMPROVEMENT IN CONDITIONS AT THAT TIME...BUT
LIKELY TO REMAIN IFR. RAIN SHOULD TAPER OFF TO MORE OCNL -SHRA OR
-DZ LATER FRIDAY EVENING INTO THE OVERNIGHT WITH IFR PROBABLY
CONTINUING.
IZZI
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE IN IFR OR LOWER CONDITIONS THROUGH FRIDAY EVENING
* LOW CONFIDENCE IN POTENTIAL FOR VLIFR IN DENSE FOG FRIDAY
* HIGH CONFIDENCE IN TIMING OF ONSET OF STEADIER RAIN +/- AN HOUR
OR SO
* LOW CONFIDENCE IN POTENTIAL FOR FZDZ FRIDAY MORNING
IZZI
//OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z...
00Z...
SATURDAY...GUSTY WEST WINDS WITH A CHANCE OF -SN WITH IFR/MVFR
POSSIBLE EARLY. VFR/WX NIL OVERNIGHT.
SUNDAY...GUSTY SOUTH WINDS. VFR/WX NIL EARLY. SLIGHT CHANCE OF
RAIN OR SNOW WITH MVFR POSSIBLE OVERNIGHT.
MONDAY...VFR/WX NIL.
TUESDAY...SLIGHT CHANCE OF SNOW. MVFR POSSIBLE.
WEDNESDAY...VFR/WX NIL.
KJB
&&
.MARINE...
219 PM CST
BROAD SURFACE RIDGE ALONG THE EASTERN SEABOARD STRETCHES FROM QUEBEC
SOUTH THROUGH THE CAROLINAS...WITH AN INFLUENCING REMAINING ACROSS
THE WESTERN GREAT LAKES THIS AFTERNOON. THE LARGEST INFLUENCE HAS
BEEN THE LACK OF A GRADIENT...WHICH HAS RESULTED IN WINDS BEING MUCH
LIGHTER THAN EARLIER ANTICIPATED. THUS HAVE SLOWED THE WIND SPEEDS
DOWN...AND ALSO HAS RESULTED IN WINDS REMAINING MORE SOUTHEASTERLY.
A BOUNDARY WAS LIFTING NORTH ACROSS THE OHIO VALLEY...AND WILL
LIKELY REACH THE SOUTHERN PORTIONS OF THE LAKE OVERNIGHT THEN ALLOW
WINDS TO TURN MORE SOUTHERLY FOR THE LAKE.
OVERNIGHT INTO FRIDAY GUIDANCE CONTINUES TO SUGGEST THE LACK OF A
GRADIENT WILL REMAIN WEST OF LAKE MICHIGAN...THEN THE CHANNEL OF
BETTER WINDS WILL EVENTUALLY SLIDE EAST/SOUTHEAST ACROSS THE LAKE
FRIDAY AFTERNOON/EVENING. SFC FLOW WILL REMAIN SOUTHERLY...WITH
SPEEDS GENERALLY AROUND 20 TO 30 KT. AT THIS TIME IT APPEARS
HAZARDOUS WINDS FOR SMALL CRAFT WILL DEVELOP AROUND THIS TIME AS
WELL.
THEN THE FOCUS FOR THE WEEKEND WILL BE ON A DEVELOPING LOW PRESSURE
SYSTEM THAT IS EXPECTED TO DEVELOP ACROSS THE SOUTHERN
PLAINS...WHICH WILL EVENTUALLY LIFT NORTHEAST ACROSS LATE SATURDAY
MORNING. THE GRADIENT WILL TIGHTEN SATURDAY EVENING...POSSIBLY
BRINGING SOME OCCASIONAL GUSTS TO 30 KT. THEN THE GRADIENT BEGINS TO
SLACKEN OFF THROUGH EARLY SUNDAY. YET ANOTHER LOW PRESSURE SYSTEM IS
EXPECTED TO SLIDE EAST ACROSS THE UPPER MIDWEST SUN AFTN...WITH THE
GRADIENT TIGHTENING YET AGAIN FOR LAKE MICHIGAN. CURRENT FORECAST
GUIDANCE INDICATES THE POSSIBILITY OF OCCASIONAL GALE FORCE GUSTS
FOR THE OPEN WATERS SUN LATE AFTN/EVE.
THE PATTERN REMAINS RELATIVELY ACTIVE FOR EARLY NEXT WEEK...WITH
ANOTHER LOW PRESSURE SYSTEM POISED TO SLIDE SOUTHEAST FROM THE UPPER
MIDWEST INTO THE GREAT LAKES. THE GRADIENT WILL ONCE AGAIN
TIGHTEN...WITH WINDS EVENTUALLY TURNING WEST/NORTHWESTERLY TUE
NGT/WED.
THE AMOUNT OF ICE REMAINS HIGH ACROSS NEARSHORE WATERS AS SEEN IN
WEBCAMS AND SATELLITE IMAGERY. THUS WAVES WILL BE OMITTED FROM THE
NEARSHORE FORECAST.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1223 PM EST FRI JAN 10 2014
.SYNOPSIS...
ISSUED AT 420 AM EST FRI JAN 10 2014
SOME PATCHY DRIZZLE OF FREEZING DRIZZLE CAN BE EXPECTED THIS
MORNING AS AN UPPER LEVEL DISTURBANCE SHIFTS EAST OF THE AREA. A
STRONGER UPPER LEVEL DISTURBANCE WILL CONTINUE TO TAKE SHAPE
ACROSS THE PLAINS TODAY AND WILL TRACK EASTWARD TONIGHT BRINGING
WIDESPREAD RAIN TO THE AREA. RAIN WILL TAPER FROM WEST TO EAST
LATE TONIGHT INTO EARLY SATURDAY. HIGH TEMPERATURES THIS AFTERNOON
WILL RANGE FROM THE MID AND UPPER 30S ACROSS CENTRAL LOWER
MICHIGAN TO THE LOWER TO MID 40S FROM CENTRAL INDIANA INTO WEST
CENTRAL OHIO. LOW TEMPERATURES TONIGHT WILL DROP INTO THE MID AND
UPPER 30S FOR MOST LOCATIONS...WITH LOWER 40S ACROSS WEST CENTRAL
OHIO.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 420 AM EST FRI JAN 10 2014
BRIEF LULL IN MEASURABLE PRECIP IS SETTING UP THIS MORNING AS
STRONGEST DPVA WITH COMPACT SHORT WAVE HAS SHIFTED INTO NORTHWEST
OHIO...AND THIS FORCING WILL QUICKLY TRANSLATE EASTWARD THIS
MORNING OUT OF THE FORECAST AREA. REDUCED STATIC STABILITY IN THE
MID LEVELS AND STEEP MID/UPPER LEVEL LAPSE RATES HAVE ALLOWED
SECONDARY BLOSSOMING OF RADAR RETURNS PAST FEW HOURS ACROSS FAR
SOUTHEAST PORTIONS OF THE AREA. HOWEVER...DRIER MID LEVEL AIR IS
ALREADY ADVECTING ACROSS THESE LOCATIONS WITH RAP SHORT TERM
BUFFER SOUNDINGS INDICATING TRANSITION TO MORE OF A LIGHT FREEZING
DRIZZLE PRECIP TYPE. WEAK UPPER LEVEL SHORT WAVE
RIDGING/SUBSIDENCE WILL CONTINUE TO BUILD INTO THE AREA FOR A
SHORT TERM THIS MORNING WITH ONLY VERY SHALLOW AND WEAK VERTICAL
MOTIONS THIS MORNING. SECONDARY LOW LEVEL ISENTROPIC SURGE APPEARS
TO BE TAKING SHAPE ACROSS CENTRAL INDIANA WITH SECONDARY WARM
FRONT...AND REGIONAL RADAR MOSAIC/SFC OBS HAVE BEEN INDICATING
INCREASING -DZ/-FZDZ ACROSS CENTRAL INDIANA. EXPECTING DRIZZLE TO
INCREASE IN COVERAGE TOWARD 12Z ACROSS THE AREA WITH NEAR SFC WET
BULBS VERY MARGINAL IN TERMS OF SUPPORTING DRIZZLE OR FREEZING
DRIZZLE...PARTICULARLY ACROSS THE FAR SOUTH. WILL KEEP -FZDZ
MENTION GOING THIS MORNING AND HAVE MAINTAINED NATURE OF PREVIOUS
FORECAST IN SOUTH TO NORTH EVOLUTION THROUGH THE MORNING HOURS OF
TRANSITION FROM -FZDZ TO -DZ. WITH LOW CONFIDENCE IN
EXTENT/INTENSITY OF ANY FZDZ THIS MORNING AND INCREASING MARGINAL
LOW LEVEL WET BULB PROFILES WILL HOLD OFF ON ANY HEADLINES AND
CONTINUE MENTION IN MORNING HWO. OTHERWISE A MILDER DAY IN STORE
ALTHOUGH SOLID SNOWPACK ACROSS THE AREA WILL LIMIT EXTENT OF SFC
WARMUP WITH WAA...WITH HIGHS GENERALLY FROM MID 30S TO AROUND 40.
FOG ALSO EXPECTED TO BECOME MORE PREVALENT TODAY FROM SOUTHWEST TO
NORTHEAST WITH LOW LEVEL MOISTURE ADVECTION OVER SNOWPACK.
FOCUS FOR THE REMAINDER OF THE SHORT TERM WILL THEN SHIFT TO
INCREASING RAIN POTENTIAL LATER THIS AFTERNOON INTO TONIGHT ALONG
WITH POTENTIAL HYDROLOGIC IMPACTS. WATER VAPOR IMAGERY EARLY THIS
MORNING DEPICTS DIGGING UPPER TROUGH APPROACHING THE CENTRAL PLAINS
WITH SECONDARY WEAKER SHORT WAVE APPROACHING WEST TEXAS. MODEL
GUIDANCE HAS BEEN FAIRLY CONSISTENT IN MAINTAINING AN UNPHASED
NATURE WITH THESE TWO SHORT WAVES...QUICKLY TAKING THE WEST TEXAS
VORT MAX INTO THE WESTERN GREAT LAKES THIS EVENING. BROAD WARM/MOIST
ADVECTION TO OCCUR TODAY...WITH MORE FOCUSED AXIS OF DEEPER
MOISTURE SETTING UP IN VICINITY OF LOW/MID LEVEL CONFLUENCE ZONE
ACROSS THE WESTERN GREAT LAKES. HAVE CONTINUED UPWARD TREND TO
CATEGORICAL POPS FOR LATE THIS AFTERNOON ACROSS APPROXIMATELY
WESTERN THIRD OF THE AREA WITH PERIODS OF MODERATE RAIN EXPECTED
IN THE 21Z-03Z TIMEFRAME.
ON HEELS OF THIS LEAD WAVE...EXPECTING LARGER SCALE FRONTAL
RESPONSE TO INCREASE ACROSS THE MID MS RIVER VALLEY EARLY THIS
EVENING IN ADVANCE OF MORE AMPLIFIED CENTRAL PLAINS TROUGH. A
STRONG LLJ WILL VEER THIS EVENING IN ADVANCE OF THIS TROUGH AND
SHOULD ADVECT PRIMARY LOW LEVEL THERMAL/MOIST AXIS ACROSS SERN
PORTIONS OF THE FORECAST AREA LATER THIS EVENING INTO THE
OVERNIGHT HOURS. PREFRONTAL CONVERGENCE AXIS SHOULD BE PROGRESSIVE
ACROSS THE AREA SO CONFIDENCE SOMEWHAT LOW ON EXACT RAINFALL
AMOUNTS ACROSS SOUTHEAST OF THE AREA WITH POTENTIAL OF HEAVIEST
AMOUNTS REMAINING JUST TO EAST AND SOUTHEAST. HAVE MADE VERY FEW
CHANGES TO PREVIOUS FORECAST WITH RAINFALL AMOUNTS IN THE HALF
INCH TO INCH RANGE. IN ADDITION TO THIS RAIN...EXISTING SNOWPACK
DOES CONTAIN 1 TO 2 INCHES OF LIQUID EQUIVALENT...WITH 2+ INCHES
ACROSS THE FAR NORTH ACROSS SOUTHERN LOWER MICHIGAN. STILL SOME
UNCERTAINTY AS TO EXTENT/TIMING OF RUNOFF FROM RAIN/SNOWMELT GIVEN
FLUCTUATING SFC TEMPS OVER THE NEXT FEW DAYS. IF HIGHER END OF
FORECASTED RAINFALL AMOUNTS DO OCCUR...PORTIONS OF MAUMEE AND
WABASH RIVER BASINS STILL APPEAR TO STAND GREATEST RISK OF MINOR
FLOODING OVER NEXT FEW DAYS GIVEN WARMER LOW LEVEL PROFILES AND
GREATER RUNOFF FROM SNOWMELT. ACROSS THE FAR NORTH WHERE GREATER
LIQUID EQUIVALENT IN SNOWPACK EXISTS...CONFIDENCE REMAINS
SOMEWHAT LOWER IN TERMS OF EXTENT/TIMING OF SNOWMELT GIVEN COOLER
LOW LEVEL TEMPS ACROSS THESE LOCATIONS. HOWEVER...GIVEN MORE
FAVORABLE TRACK WITH INITIAL SHORT WAVE THIS EVENING...SOME
LOCALLY HIGHER RAINFALL AMOUNTS ARE POSSIBLE TONIGHT ACROSS
ESPECIALLY WESTERN PORTIONS OF ST. JOSEPH BASIN. WILL CONTINUE
WITH ESF THIS MORNING TO DISCUSS POSSIBLE HYDRO IMPACTS OVER THE
NEXT SEVERAL DAYS.
&&
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 420 AM EST FRI JAN 10 2014
VORT MAX WILL BE SWEEPING ACROSS THE CWA AT THE START OF THE
PERIOD...WITH RAIN QUICKLY SHIFTING WEST TO EAST DURING THE MORNING
HOURS AS COLD FRONT USHERS IN A QUICK SHOT OF COOLER AIR. THIS WILL
ALLOW A BRIEF PERIOD FOR RAIN/SNOW MIX ACROSS THE AREA. HOWEVER...BY
THIS POINT DEEPEST MSTR AND LIFT WILL BE SHIFTING EAST...KEEPING ANY
ACCUMULATION POTENTIAL TO A MINIMUM. PREV FORECAST GENERALLY LEFT
INTACT. 925 MB TEMPS WILL BOTTOM OUT AROUND -5 C BY LATE SAT
NGT...TRANSLATING TO LOWS IN THE MID TO UPR 20S...STILL A GOOD 10
DEGREES OR MORE ABOVE NORMAL FOR MID JANUARY.
UPPER LEVEL RIDGING WILL QUICKLY MOVE BACK IN BY SUNDAY WITH RETURN
TO ABOVE NORMAL TEMPS IN TO THE 30S AND POSSIBLY LOW 40S WITH
EFFECTS OF SNOWPACK BEING GREATLY REDUCED. TEMPS WILL STAY ABOVE
FREEZING INTO MONDAY IN ADVANCE OF YET ANOTHER NORTHERN STREAM
TROUGH TO BRING A CHANCE OF RAIN. A FEW OF THE MODELS SHOW POTENTIAL
INTERACTION WITH SOUTHERN STREAM ENERGY BUT EVEN THE STRONGEST ECMWF
ONLY SHOWS A SHARPENING OF THE PROGRESSIVE TROUGH. STATUS QUO FOR
THE TIME BEING MON/MON NGT WITH CHC POPS AS BEST POTENTIAL REMAINS N
AND S OF THE AREA. ACTIVE PATTERN CONTINUES WITH OVERALL LONGWAVE
TROUGH REMAINING IN PLACE ACROSS THE GREAT LAKES WITH A STRONGER
WAVE DROPPING THROUGH FOR MID WEEK. MODELS DIVERGE EVEN FURTHER WITH
ECMWF CLOSING OFF A PROGRESSIVE UPPER LOW OVER THE CAROLINAS BY
WEDNESDAY EVENING. WILL KEEP CONSERVATIVE LOW END POPS IN N AREAS
THURSDAY AS MAIN TROUGH MOVES IN. TEMPERATURES WILL HOVER EITHER
SIDE OF NORMAL WITH WARM UPS AHEAD OF EACH WAVE AND DROP TO SLIGHTLY
BELOW NORMAL BEHIND IT. SOME INDICATIONS OF RETURN OF COLDER...BELOW
NORMAL AIR OUTSIDE THE PERIOD BUT BY FAR MUCH WARMER THAN RECENT
POLAR BLAST.
FLOODING CONCERNS WILL LIKELY LINGER THROUGH MUCH OF THE
PERIOD...BUT EXACT MAGNITUDE WILL BE TRICKY TO SORT OUT AS MUCH OF
IT WILL FOCUS ON QPF OVER THE NEXT DAY OR SO. WILL CONTINUE WITH HWO
MENTION INTO MID WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1223 PM EST FRI JAN 10 2014
IFR CONDITIONS WILL PERSIST THROUGH MUCH OF THE PERIOD AS MOIST
SOUTHERLY FLOW CONTINUES OVER AN EXISTING/MELTING SNOWPACK. MAY
SEE A BRIEF PERIOD OF MVFR AT MAINLY FWA THIS AFTN BEFORE
WIDESPREAD RAIN/IFR SPREADS INTO NORTHERN INDIANA EARLY THIS
EVENING AND LINGERS INTO FRIDAY MORNING.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...DENSE FOG ADVISORY UNTIL 4 PM EST /3 PM CST/ THIS AFTERNOON FOR
INZ003>007.
MI...DENSE FOG ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR MIZ077>081.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...MARSILI
SHORT TERM...MARSILI
LONG TERM...FISHER
AVIATION...STEINWEDEL
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AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
645 AM EST FRI JAN 10 2014
.SYNOPSIS...
ISSUED AT 420 AM EST FRI JAN 10 2014
SOME PATCHY DRIZZLE OF FREEZING DRIZZLE CAN BE EXPECTED THIS
MORNING AS AN UPPER LEVEL DISTURBANCE SHIFTS EAST OF THE AREA. A
STRONGER UPPER LEVEL DISTURBANCE WILL CONTINUE TO TAKE SHAPE
ACROSS THE PLAINS TODAY AND WILL TRACK EASTWARD TONIGHT BRINGING
WIDESPREAD RAIN TO THE AREA. RAIN WILL TAPER FROM WEST TO EAST
LATE TONIGHT INTO EARLY SATURDAY. HIGH TEMPERATURES THIS AFTERNOON
WILL RANGE FROM THE MID AND UPPER 30S ACROSS CENTRAL LOWER
MICHIGAN TO THE LOWER TO MID 40S FROM CENTRAL INDIANA INTO WEST
CENTRAL OHIO. LOW TEMPERATURES TONIGHT WILL DROP INTO THE MID AND
UPPER 30S FOR MOST LOCATIONS...WITH LOWER 40S ACROSS WEST CENTRAL
OHIO.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 420 AM EST FRI JAN 10 2014
BRIEF LULL IN MEASURABLE PRECIP IS SETTING UP THIS MORNING AS
STRONGEST DPVA WITH COMPACT SHORT WAVE HAS SHIFTED INTO NORTHWEST
OHIO...AND THIS FORCING WILL QUICKLY TRANSLATE EASTWARD THIS
MORNING OUT OF THE FORECAST AREA. REDUCED STATIC STABILITY IN THE
MID LEVELS AND STEEP MID/UPPER LEVEL LAPSE RATES HAVE ALLOWED
SECONDARY BLOSSOMING OF RADAR RETURNS PAST FEW HOURS ACROSS FAR
SOUTHEAST PORTIONS OF THE AREA. HOWEVER...DRIER MID LEVEL AIR IS
ALREADY ADVECTING ACROSS THESE LOCATIONS WITH RAP SHORT TERM
BUFFER SOUNDINGS INDICATING TRANSITION TO MORE OF A LIGHT FREEZING
DRIZZLE PRECIP TYPE. WEAK UPPER LEVEL SHORT WAVE
RIDGING/SUBSIDENCE WILL CONTINUE TO BUILD INTO THE AREA FOR A
SHORT TERM THIS MORNING WITH ONLY VERY SHALLOW AND WEAK VERTICAL
MOTIONS THIS MORNING. SECONDARY LOW LEVEL ISENTROPIC SURGE APPEARS
TO BE TAKING SHAPE ACROSS CENTRAL INDIANA WITH SECONDARY WARM
FRONT...AND REGIONAL RADAR MOSAIC/SFC OBS HAVE BEEN INDICATING
INCREASING -DZ/-FZDZ ACROSS CENTRAL INDIANA. EXPECTING DRIZZLE TO
INCREASE IN COVERAGE TOWARD 12Z ACROSS THE AREA WITH NEAR SFC WET
BULBS VERY MARGINAL IN TERMS OF SUPPORTING DRIZZLE OR FREEZING
DRIZZLE...PARTICULARLY ACROSS THE FAR SOUTH. WILL KEEP -FZDZ
MENTION GOING THIS MORNING AND HAVE MAINTAINED NATURE OF PREVIOUS
FORECAST IN SOUTH TO NORTH EVOLUTION THROUGH THE MORNING HOURS OF
TRANSITION FROM -FZDZ TO -DZ. WITH LOW CONFIDENCE IN
EXTENT/INTENSITY OF ANY FZDZ THIS MORNING AND INCREASING MARGINAL
LOW LEVEL WET BULB PROFILES WILL HOLD OFF ON ANY HEADLINES AND
CONTINUE MENTION IN MORNING HWO. OTHERWISE A MILDER DAY IN STORE
ALTHOUGH SOLID SNOWPACK ACROSS THE AREA WILL LIMIT EXTENT OF SFC
WARMUP WITH WAA...WITH HIGHS GENERALLY FROM MID 30S TO AROUND 40.
FOG ALSO EXPECTED TO BECOME MORE PREVALENT TODAY FROM SOUTHWEST TO
NORTHEAST WITH LOW LEVEL MOISTURE ADVECTION OVER SNOWPACK.
FOCUS FOR THE REMAINDER OF THE SHORT TERM WILL THEN SHIFT TO
INCREASING RAIN POTENTIAL LATER THIS AFTERNOON INTO TONIGHT ALONG
WITH POTENTIAL HYDROLOGIC IMPACTS. WATER VAPOR IMAGERY EARLY THIS
MORNING DEPICTS DIGGING UPPER TROUGH APPROACHING THE CENTRAL PLAINS
WITH SECONDARY WEAKER SHORT WAVE APPROACHING WEST TEXAS. MODEL
GUIDANCE HAS BEEN FAIRLY CONSISTENT IN MAINTAINING AN UNPHASED
NATURE WITH THESE TWO SHORT WAVES...QUICKLY TAKING THE WEST TEXAS
VORT MAX INTO THE WESTERN GREAT LAKES THIS EVENING. BROAD WARM/MOIST
ADVECTION TO OCCUR TODAY...WITH MORE FOCUSED AXIS OF DEEPER
MOISTURE SETTING UP IN VICINITY OF LOW/MID LEVEL CONFLUENCE ZONE
ACROSS THE WESTERN GREAT LAKES. HAVE CONTINUED UPWARD TREND TO
CATEGORICAL POPS FOR LATE THIS AFTERNOON ACROSS APPROXIMATELY
WESTERN THIRD OF THE AREA WITH PERIODS OF MODERATE RAIN EXPECTED
IN THE 21Z-03Z TIMEFRAME.
ON HEELS OF THIS LEAD WAVE...EXPECTING LARGER SCALE FRONTAL
RESPONSE TO INCREASE ACROSS THE MID MS RIVER VALLEY EARLY THIS
EVENING IN ADVANCE OF MORE AMPLIFIED CENTRAL PLAINS TROUGH. A
STRONG LLJ WILL VEER THIS EVENING IN ADVANCE OF THIS TROUGH AND
SHOULD ADVECT PRIMARY LOW LEVEL THERMAL/MOIST AXIS ACROSS SERN
PORTIONS OF THE FORECAST AREA LATER THIS EVENING INTO THE
OVERNIGHT HOURS. PREFRONTAL CONVERGENCE AXIS SHOULD BE PROGRESSIVE
ACROSS THE AREA SO CONFIDENCE SOMEWHAT LOW ON EXACT RAINFALL
AMOUNTS ACROSS SOUTHEAST OF THE AREA WITH POTENTIAL OF HEAVIEST
AMOUNTS REMAINING JUST TO EAST AND SOUTHEAST. HAVE MADE VERY FEW
CHANGES TO PREVIOUS FORECAST WITH RAINFALL AMOUNTS IN THE HALF
INCH TO INCH RANGE. IN ADDITION TO THIS RAIN...EXISTING SNOWPACK
DOES CONTAIN 1 TO 2 INCHES OF LIQUID EQUIVALENT...WITH 2+ INCHES
ACROSS THE FAR NORTH ACROSS SOUTHERN LOWER MICHIGAN. STILL SOME
UNCERTAINTY AS TO EXTENT/TIMING OF RUNOFF FROM RAIN/SNOWMELT GIVEN
FLUCTUATING SFC TEMPS OVER THE NEXT FEW DAYS. IF HIGHER END OF
FORECASTED RAINFALL AMOUNTS DO OCCUR...PORTIONS OF MAUMEE AND
WABASH RIVER BASINS STILL APPEAR TO STAND GREATEST RISK OF MINOR
FLOODING OVER NEXT FEW DAYS GIVEN WARMER LOW LEVEL PROFILES AND
GREATER RUNOFF FROM SNOWMELT. ACROSS THE FAR NORTH WHERE GREATER
LIQUID EQUIVALENT IN SNOWPACK EXISTS...CONFIDENCE REMAINS
SOMEWHAT LOWER IN TERMS OF EXTENT/TIMING OF SNOWMELT GIVEN COOLER
LOW LEVEL TEMPS ACROSS THESE LOCATIONS. HOWEVER...GIVEN MORE
FAVORABLE TRACK WITH INITIAL SHORT WAVE THIS EVENING...SOME
LOCALLY HIGHER RAINFALL AMOUNTS ARE POSSIBLE TONIGHT ACROSS
ESPECIALLY WESTERN PORTIONS OF ST. JOSEPH BASIN. WILL CONTINUE
WITH ESF THIS MORNING TO DISCUSS POSSIBLE HYDRO IMPACTS OVER THE
NEXT SEVERAL DAYS.
&&
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 420 AM EST FRI JAN 10 2014
VORT MAX WILL BE SWEEPING ACROSS THE CWA AT THE START OF THE
PERIOD...WITH RAIN QUICKLY SHIFTING WEST TO EAST DURING THE MORNING
HOURS AS COLD FRONT USHERS IN A QUICK SHOT OF COOLER AIR. THIS WILL
ALLOW A BRIEF PERIOD FOR RAIN/SNOW MIX ACROSS THE AREA. HOWEVER...BY
THIS POINT DEEPEST MSTR AND LIFT WILL BE SHIFTING EAST...KEEPING ANY
ACCUMULATION POTENTIAL TO A MINIMUM. PREV FORECAST GENERALLY LEFT
INTACT. 925 MB TEMPS WILL BOTTOM OUT AROUND -5 C BY LATE SAT
NGT...TRANSLATING TO LOWS IN THE MID TO UPR 20S...STILL A GOOD 10
DEGREES OR MORE ABOVE NORMAL FOR MID JANUARY.
UPPER LEVEL RIDGING WILL QUICKLY MOVE BACK IN BY SUNDAY WITH RETURN
TO ABOVE NORMAL TEMPS IN TO THE 30S AND POSSIBLY LOW 40S WITH
EFFECTS OF SNOWPACK BEING GREATLY REDUCED. TEMPS WILL STAY ABOVE
FREEZING INTO MONDAY IN ADVANCE OF YET ANOTHER NORTHERN STREAM
TROUGH TO BRING A CHANCE OF RAIN. A FEW OF THE MODELS SHOW POTENTIAL
INTERACTION WITH SOUTHERN STREAM ENERGY BUT EVEN THE STRONGEST ECMWF
ONLY SHOWS A SHARPENING OF THE PROGRESSIVE TROUGH. STATUS QUO FOR
THE TIME BEING MON/MON NGT WITH CHC POPS AS BEST POTENTIAL REMAINS N
AND S OF THE AREA. ACTIVE PATTERN CONTINUES WITH OVERALL LONGWAVE
TROUGH REMAINING IN PLACE ACROSS THE GREAT LAKES WITH A STRONGER
WAVE DROPPING THROUGH FOR MID WEEK. MODELS DIVERGE EVEN FURTHER WITH
ECMWF CLOSING OFF A PROGRESSIVE UPPER LOW OVER THE CAROLINAS BY
WEDNESDAY EVENING. WILL KEEP CONSERVATIVE LOW END POPS IN N AREAS
THURSDAY AS MAIN TROUGH MOVES IN. TEMPERATURES WILL HOVER EITHER
SIDE OF NORMAL WITH WARM UPS AHEAD OF EACH WAVE AND DROP TO SLIGHTLY
BELOW NORMAL BEHIND IT. SOME INDICATIONS OF RETURN OF COLDER...BELOW
NORMAL AIR OUTSIDE THE PERIOD BUT BY FAR MUCH WARMER THAN RECENT
POLAR BLAST.
FLOODING CONCERNS WILL LIKELY LINGER THROUGH MUCH OF THE
PERIOD...BUT EXACT MAGNITUDE WILL BE TRICKY TO SORT OUT AS MUCH OF
IT WILL FOCUS ON QPF OVER THE NEXT DAY OR SO. WILL CONTINUE WITH HWO
MENTION INTO MID WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 622 AM EST FRI JAN 10 2014
THE SHORT WAVE WHICH BROUGHT SNOW TO THE AREA LAST EVENING HAS
EXITED TO THE EAST. DRY MID LEVEL AIR IN THE WAKE OF THIS SHORT
WAVE AND CONTINUED WEAK LOW LEVEL LIFT HAS ALLOWED FOR PATCHY
DRIZZLE/FREEZING DRIZZLE TO FORM ACROSS NORTHERN INDIANA.
INTENSITY OF THIS PRECIP WILL REMAIN VERY LIGHT THIS MORNING WITH
MOISTURE DEPTH INCREASING THIS AFTERNOON IN ADVANCE OF A STRONGER
UPPER LEVEL DISTURBANCE KICKING OUT OF THE PLAINS. WIDESPREAD RAIN
IS EXPECTED TO DEVELOP LATE AFTERNOON ACROSS NWRN INDIANA AND
SPREAD EASTWARD ACROSS NORTHERN INDIANA EARLY THIS EVENING.
CONTINUED LOW LEVEL WARM/MOISTURE ADVECTION THROUGH THE PERIOD
OVER EXISTING SNOWPACK WILL OFFER LITTLE OPPORTUNITY TO IMPROVE
IFR/LIFR CONDITIONS THROUGH THIS FORECAST PERIOD.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...MARSILI
SHORT TERM...MARSILI
LONG TERM...FISHER
AVIATION...MARSILI
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
433 AM EST FRI JAN 10 2014
.SYNOPSIS...
ISSUED AT 420 AM EST FRI JAN 10 2014
SOME PATCHY DRIZZLE OF FREEZING DRIZZLE CAN BE EXPECTED THIS
MORNING AS AN UPPER LEVEL DISTURBANCE SHIFTS EAST OF THE AREA. A
STRONGER UPPER LEVEL DISTURBANCE WILL CONTINUE TO TAKE SHAPE
ACROSS THE PLAINS TODAY AND WILL TRACK EASTWARD TONIGHT BRINGING
WIDESPREAD RAIN TO THE AREA. RAIN WILL TAPER FROM WEST TO EAST
LATE TONIGHT INTO EARLY SATURDAY. HIGH TEMPERATURES THIS AFTERNOON
WILL RANGE FROM THE MID AND UPPER 30S ACROSS CENTRAL LOWER
MICHIGAN TO THE LOWER TO MID 40S FROM CENTRAL INDIANA INTO WEST
CENTRAL OHIO. LOW TEMPERATURES TONIGHT WILL DROP INTO THE MID AND
UPPER 30S FOR MOST LOCATIONS...WITH LOWER 40S ACROSS WEST CENTRAL
OHIO.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 420 AM EST FRI JAN 10 2014
BRIEF LULL IN MEASURABLE PRECIP IS SETTING UP THIS MORNING AS
STRONGEST DPVA WITH COMPACT SHORT WAVE HAS SHIFTED INTO NORTHWEST
OHIO...AND THIS FORCING WILL QUICKLY TRANSLATE EASTWARD THIS
MORNING OUT OF THE FORECAST AREA. REDUCED STATIC STABILITY IN THE
MID LEVELS AND STEEP MID/UPPER LEVEL LAPSE RATES HAVE ALLOWED
SECONDARY BLOSSOMING OF RADAR RETURNS PAST FEW HOURS ACROSS FAR
SOUTHEAST PORTIONS OF THE AREA. HOWEVER...DRIER MID LEVEL AIR IS
ALREADY ADVECTING ACROSS THESE LOCATIONS WITH RAP SHORT TERM
BUFFER SOUNDINGS INDICATING TRANSITION TO MORE OF A LIGHT FREEZING
DRIZZLE PRECIP TYPE. WEAK UPPER LEVEL SHORT WAVE
RIDGING/SUBSIDENCE WILL CONTINUE TO BUILD INTO THE AREA FOR A
SHORT TERM THIS MORNING WITH ONLY VERY SHALLOW AND WEAK VERTICAL
MOTIONS THIS MORNING. SECONDARY LOW LEVEL ISENTROPIC SURGE APPEARS
TO BE TAKING SHAPE ACROSS CENTRAL INDIANA WITH SECONDARY WARM
FRONT...AND REGIONAL RADAR MOSAIC/SFC OBS HAVE BEEN INDICATING
INCREASING -DZ/-FZDZ ACROSS CENTRAL INDIANA. EXPECTING DRIZZLE TO
INCREASE IN COVERAGE TOWARD 12Z ACROSS THE AREA WITH NEAR SFC WET
BULBS VERY MARGINAL IN TERMS OF SUPPORTING DRIZZLE OR FREEZING
DRIZZLE...PARTICULARLY ACROSS THE FAR SOUTH. WILL KEEP -FZDZ
MENTION GOING THIS MORNING AND HAVE MAINTAINED NATURE OF PREVIOUS
FORECAST IN SOUTH TO NORTH EVOLUTION THROUGH THE MORNING HOURS OF
TRANSITION FROM -FZDZ TO -DZ. WITH LOW CONFIDENCE IN
EXTENT/INTENSITY OF ANY FZDZ THIS MORNING AND INCREASING MARGINAL
LOW LEVEL WET BULB PROFILES WILL HOLD OFF ON ANY HEADLINES AND
CONTINUE MENTION IN MORNING HWO. OTHERWISE A MILDER DAY IN STORE
ALTHOUGH SOLID SNOWPACK ACROSS THE AREA WILL LIMIT EXTENT OF SFC
WARMUP WITH WAA...WITH HIGHS GENERALLY FROM MID 30S TO AROUND 40.
FOG ALSO EXPECTED TO BECOME MORE PREVALENT TODAY FROM SOUTHWEST TO
NORTHEAST WITH LOW LEVEL MOISTURE ADVECTION OVER SNOWPACK.
FOCUS FOR THE REMAINDER OF THE SHORT TERM WILL THEN SHIFT TO
INCREASING RAIN POTENTIAL LATER THIS AFTERNOON INTO TONIGHT ALONG
WITH POTENTIAL HYDROLOGIC IMPACTS. WATER VAPOR IMAGERY EARLY THIS
MORNING DEPICTS DIGGING UPPER TROUGH APPROACHING THE CENTRAL PLAINS
WITH SECONDARY WEAKER SHORT WAVE APPROACHING WEST TEXAS. MODEL
GUIDANCE HAS BEEN FAIRLY CONSISTENT IN MAINTAINING AN UNPHASED
NATURE WITH THESE TWO SHORT WAVES...QUICKLY TAKING THE WEST TEXAS
VORT MAX INTO THE WESTERN GREAT LAKES THIS EVENING. BROAD WARM/MOIST
ADVECTION TO OCCUR TODAY...WITH MORE FOCUSED AXIS OF DEEPER
MOISTURE SETTING UP IN VICINITY OF LOW/MID LEVEL CONFLUENCE ZONE
ACROSS THE WESTERN GREAT LAKES. HAVE CONTINUED UPWARD TREND TO
CATEGORICAL POPS FOR LATE THIS AFTERNOON ACROSS APPROXIMATELY
WESTERN THIRD OF THE AREA WITH PERIODS OF MODERATE RAIN EXPECTED
IN THE 21Z-03Z TIMEFRAME.
ON HEELS OF THIS LEAD WAVE...EXPECTING LARGER SCALE FRONTAL
RESPONSE TO INCREASE ACROSS THE MID MS RIVER VALLEY EARLY THIS
EVENING IN ADVANCE OF MORE AMPLIFIED CENTRAL PLAINS TROUGH. A
STRONG LLJ WILL VEER THIS EVENING IN ADVANCE OF THIS TROUGH AND
SHOULD ADVECT PRIMARY LOW LEVEL THERMAL/MOIST AXIS ACROSS SERN
PORTIONS OF THE FORECAST AREA LATER THIS EVENING INTO THE
OVERNIGHT HOURS. PREFRONTAL CONVERGENCE AXIS SHOULD BE PROGRESSIVE
ACROSS THE AREA SO CONFIDENCE SOMEWHAT LOW ON EXACT RAINFALL
AMOUNTS ACROSS SOUTHEAST OF THE AREA WITH POTENTIAL OF HEAVIEST
AMOUNTS REMAINING JUST TO EAST AND SOUTHEAST. HAVE MADE VERY FEW
CHANGES TO PREVIOUS FORECAST WITH RAINFALL AMOUNTS IN THE HALF
INCH TO INCH RANGE. IN ADDITION TO THIS RAIN...EXISTING SNOWPACK
DOES CONTAIN 1 TO 2 INCHES OF LIQUID EQUIVALENT...WITH 2+ INCHES
ACROSS THE FAR NORTH ACROSS SOUTHERN LOWER MICHIGAN. STILL SOME
UNCERTAINTY AS TO EXTENT/TIMING OF RUNOFF FROM RAIN/SNOWMELT GIVEN
FLUCTUATING SFC TEMPS OVER THE NEXT FEW DAYS. IF HIGHER END OF
FORECASTED RAINFALL AMOUNTS DO OCCUR...PORTIONS OF MAUMEE AND
WABASH RIVER BASINS STILL APPEAR TO STAND GREATEST RISK OF MINOR
FLOODING OVER NEXT FEW DAYS GIVEN WARMER LOW LEVEL PROFILES AND
GREATER RUNOFF FROM SNOWMELT. ACROSS THE FAR NORTH WHERE GREATER
LIQUID EQUIVALENT IN SNOWPACK EXISTS...CONFIDENCE REMAINS
SOMEWHAT LOWER IN TERMS OF EXTENT/TIMING OF SNOWMELT GIVEN COOLER
LOW LEVEL TEMPS ACROSS THESE LOCATIONS. HOWEVER...GIVEN MORE
FAVORABLE TRACK WITH INITIAL SHORT WAVE THIS EVENING...SOME
LOCALLY HIGHER RAINFALL AMOUNTS ARE POSSIBLE TONIGHT ACROSS
ESPECIALLY WESTERN PORTIONS OF ST. JOSEPH BASIN. WILL CONTINUE
WITH ESF THIS MORNING TO DISCUSS POSSIBLE HYDRO IMPACTS OVER THE
NEXT SEVERAL DAYS.
&&
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 420 AM EST FRI JAN 10 2014
VORT MAX WILL BE SWEEPING ACROSS THE CWA AT THE START OF THE
PERIOD...WITH RAIN QUICKLY SHIFTING WEST TO EAST DURING THE MORNING
HOURS AS COLD FRONT USHERS IN A QUICK SHOT OF COOLER AIR. THIS WILL
ALLOW A BRIEF PERIOD FOR RAIN/SNOW MIX ACROSS THE AREA. HOWEVER...BY
THIS POINT DEEPEST MSTR AND LIFT WILL BE SHIFTING EAST...KEEPING ANY
ACCUMULATION POTENTIAL TO A MINIMUM. PREV FORECAST GENERALLY LEFT
INTACT. 925 MB TEMPS WILL BOTTOM OUT AROUND -5 C BY LATE SAT
NGT...TRANSLATING TO LOWS IN THE MID TO UPR 20S...STILL A GOOD 10
DEGREES OR MORE ABOVE NORMAL FOR MID JANUARY.
UPPER LEVEL RIDGING WILL QUICKLY MOVE BACK IN BY SUNDAY WITH RETURN
TO ABOVE NORMAL TEMPS IN TO THE 30S AND POSSIBLY LOW 40S WITH
EFFECTS OF SNOWPACK BEING GREATLY REDUCED. TEMPS WILL STAY ABOVE
FREEZING INTO MONDAY IN ADVANCE OF YET ANOTHER NORTHERN STREAM
TROUGH TO BRING A CHANCE OF RAIN. A FEW OF THE MODELS SHOW POTENTIAL
INTERACTION WITH SOUTHERN STREAM ENERGY BUT EVEN THE STRONGEST ECMWF
ONLY SHOWS A SHARPENING OF THE PROGRESSIVE TROUGH. STATUS QUO FOR
THE TIME BEING MON/MON NGT WITH CHC POPS AS BEST POTENTIAL REMAINS N
AND S OF THE AREA. ACTIVE PATTERN CONTINUES WITH OVERALL LONGWAVE
TROUGH REMAINING IN PLACE ACROSS THE GREAT LAKES WITH A STRONGER
WAVE DROPPING THROUGH FOR MID WEEK. MODELS DIVERGE EVEN FURTHER WITH
ECMWF CLOSING OFF A PROGRESSIVE UPPER LOW OVER THE CAROLINAS BY
WEDNESDAY EVENING. WILL KEEP CONSERVATIVE LOW END POPS IN N AREAS
THURSDAY AS MAIN TROUGH MOVES IN. TEMPERATURES WILL HOVER EITHER
SIDE OF NORMAL WITH WARM UPS AHEAD OF EACH WAVE AND DROP TO SLIGHTLY
BELOW NORMAL BEHIND IT. SOME INDICATIONS OF RETURN OF COLDER...BELOW
NORMAL AIR OUTSIDE THE PERIOD BUT BY FAR MUCH WARMER THAN RECENT
POLAR BLAST.
FLOODING CONCERNS WILL LIKELY LINGER THROUGH MUCH OF THE
PERIOD...BUT EXACT MAGNITUDE WILL BE TRICKY TO SORT OUT AS MUCH OF
IT WILL FOCUS ON QPF OVER THE NEXT DAY OR SO. WILL CONTINUE WITH HWO
MENTION INTO MID WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 420 AM EST FRI JAN 10 2014
VERY LITTLE CHANGE IN FORECAST THINKING FOR THE 06Z TAFS.
STRONGEST DPVA WITH UPPER LEVEL VORT MAX WILL CONTINUE SLIDING
THORUGH FAR NORTHEAST INDIANA OVER NEXT FEW HOURS. CONVECTIVE TYPE
SNOW SHOWERS SHOULD TRANSITION TO MORE OF DRIZZLY STRATIFORM TYPE
PRECIP OVERNIGHT AS MID LEVEL DRYING ENSUES BEHIND THIS SHORT
WAVE. HAVE INCLUDED -FZDZSN MENTION AT KFWA BUT OVERALL IMPACTS
SHOULD BE MINIMAL. IFR CONDITIONS SHOULD DETERIORATE TO LIFR WITH
LOW LEVEL WARM/MOISTURE ADVECTION RAMPING UP OVER THE SNOWPACK
ACROSS THE AREA. NEXT LARGER SCALE STORM SYSTEM WILL DEEPEN ACROSS
THE PLAINS THIS AFTERNOON AND SHIFT EASTWARD TONIGHT...BRINGING
WIDESPREAD RAIN TO THE TERMINALS FROM LATE THIS AFTERNOON THROUGH
TONIGHT.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...MARSILI
SHORT TERM...MARSILI
LONG TERM...FISHER
AVIATION...MARSILI
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION...CORRECTED UPDATE
NWS QUAD CITIES IA IL
453 PM CST FRI JAN 10 2014
.UPDATE...
ISSUED AT 444 PM CST FRI JAN 10 2014
EXPANDED ADVISORY TO INCLUDE JACKSON COUNTY IN IOWA AND JO DAVIESS
AND STEPHENSON COUNTIES IN FAR NORTHERN ILLINOIS. REPORTS OF
SEVERAL ROADS COMPLETELY COVERED IN JACKSON COUNTY... IA38...IA136
IA64. PAVEMENT TEMPS HOVERING AROUND FREEZING IN THESE AREAS
ALLOWING FOR THE ICY CONDITIONS TO DEVELOP.
COULD ACTUALLY SEE SOME IMPROVEMENT FOR A TIME THIS EVENING AS TEMPS
CONTINUE TO SLOWLY CLIMB AHEAD OF AN APPROACHING SURFACE LOW.
HOWEVER....ONCE THIS PASSES AND WINDS SHIFT TO WEST WILL SEE TEMPS
DROP LATE THIS EVE AND OVERNIGHT AND MAY SEE MORE ICING WHETHER
THROUGH REFREEZE OR POSSIBLY SOME LIGHT FREEZING DRIZZLE/FREEZING
RAIN.
UPDATE ISSUED AT 336 PM CST FRI JAN 10 2014
CALLS ARE NOW COMING IN REPORTING SLICK ROADS. THUS WILL HOIST A
FREEZING RAIN ADVISORY FOR LATE AFTERNOON AND EVENING. TEMPORAL
AND AREAL COVERAGE OF THE ADVISORY MAY NEED TO CHANGED THIS
EVENING.
&&
.SYNOPSIS...
ISSUED AT 248 PM CST FRI JAN 10 2014
12Z UA ANALYSIS HAS A LLJ RUNNING FROM TEXAS INTO WESTERN MISSOURI.
MOISTURE ASSOCIATED WITH THIS JET WAS IMPINGING UPON AN 850 MB WARM
FRONT RUNNING FROM KANSAS INTO SOUTHERN ILLINOIS. RADAR TRENDS
THROUGH MID AFTERNOON HAD A LARGE AREA OF RAIN FROM MISSOURI INTO
ILLINOIS WITH LIGHTER RAIN/DRIZZLE MIXED WITH SOME FREEZING
RAIN/DRIZZLE ACROSS IOWA.
18Z SFC ANALYSIS HAS A WEAK LOW NEAR KMHK WITH A WARM FRONT EAST
ALONG THE MISSOURI RIVER. THE COLD FRONT RAN FROM THE LOW INTO
SOUTHWEST OKLAHOMA. DEW POINTS WERE IN THE 20S AND 30S ACROSS THE
UPPER MIDWEST AND GREAT LAKES WITH 40S AND HIGHER FROM THE OHIO
VALLEY AND SOUTHERN PLAINS.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 248 PM CST FRI JAN 10 2014
BASED ON TRENDS FROM PRESSURE FALLS AND THE RAP MODEL...THE LOW
SHOULD PASS OVER THE FAR NORTHWEST AREA BETWEEN KALO AND KCID THIS
EVENING. WINDS WILL DECREASE AS THE LOW APPROACHES AND THE FOG IS
EXPECTED TO BECOME MORE WIDESPREAD. RIGHT NOW NO ADVISORY FOR DENSE
FOG IS PLANNED. HOWEVER...I WOULD NOT BE SURPRISED IF ONE IS NEEDED
AT SOME POINT DURING THE EVENING.
TEMPERATURES HAVE NOT BUDGED MUCH IN THE HIGHWAY 20 CORRIDOR FROM
KDBQ ON WEST. THUS THIS AREA IS RIGHT ON THE CUSP OF SEEING FREEZING
RAIN LATE THIS AFTERNOON AND EVENING AS LIFT CONTINUES TO INCREASE.
HOWEVER...THE TRACK OF THE LOW SHOULD ALLOW TEMPERATURES TO RISE
ABOUT ANOTHER DEGREE. FREEZING RAIN IS EXPECTED TO BE LOCALLY SPOTTY
OVER THE FOUR NORTHWEST COUNTIES AND POSSIBLY WESTERN DUBUQUE COUNTY
THROUGH MID EVENING.
ONCE THE LOW PASSES...COLD AIR WILL SLOWLY BEGIN TO MOVE INTO THE
AREA ALLOWING THE RAIN TO MIX WITH AND CHANGE TO SNOW FROM WEST TO
EAST OVERNIGHT. DURING THE CHANGE OVER...A BRIEF PERIOD OF FREEZING
RAIN WILL BE POSSIBLE. SNOW AMOUNTS WILL RANGE FROM A TRACE TO UNDER
AN INCH.
ON SATURDAY...LINGERING LIGHT SNOW WILL BE SEE OVER ROUGHLY THE
NORTHEAST/EAST HALF OF THE AREA DURING THE MORNING. OTHERWISE DRY
CONDITIONS ARE EXPECTED DURING THE DAY. SNOW AMOUNTS SATURDAY
MORNING WILL BE A DUSTING AT BEST.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 248 PM CST FRI JAN 10 2014
NEARLY ZONAL UPPER AIR FLOW WILL BE OVER THE AREA THE REST OF THE
WEEKEND THEN THE PATTERN CHANGES TO A RIDGE DOMINATED WESTERN U.S.
AND A MEAN TROF SETTING UP OVER THE EAST.
MILD CONDITIONS ARE ANTICIPATED FOR THE REGION SUNDAY AS UPPER
RIDGING BUILDS OVER THE AREA SATURDAY NIGHT INTO SUNDAY. IN THE LOW
LEVELS A SURFACE RIDGE WILL MOVE THROUGH THE REGION SATURDAY EVENING
FOLLOWED BY STRONG LOW LEVEL WAA AHEAD OF A TROF DIGGING INTO THE
SOUTHWEST U.S. AND A COLD FRONT OVER THE PLAINS. A LOW LEVEL
THERMAL RIDGE CROSSES THE MID MISSISSIPPI VALLEY SUNDAY WITH H8
TEMPS PEAKING IN THE +8 TO +10C RANGE DURING THE AFTERNOON. GOOD
MIXING IS ALSO SUGGESTED WITH A TIGHT SLP GRADIENT AHEAD OF THE COLD
FRONT. EVEN WITH THE SNOW COVER...WE SHOULD SEE HIGHS TOPPING OUT
IN THE MID 30S TO MID 40S. MODELS MOVE THE FRONT THROUGH THE REGION
WITH OUT ANY PRECIPITATION SUNDAY NIGHT. THIS LOOKS REASONABLE WITH
THE BETTER MOISTURE GETTING PUSHED OUT WELL AHEAD OF THE SYSTEM.
THERE IS SOME CONCERN MONDAY WITH THE LESS PHASED ECM SOLUTION
LIFTING A PIECE OF THE UPPER TROF OUT OF TEXAS...SENDING A SURFACE
LOW NORTHEAST THROUGH THE OHIO VALLEY. THE ECMS PRECIP SHIELD WITH
THIS FEATURE JUST MISSES THE SOUTHEAST CWFA MONDAY.
MODELS DO AGREE ON A WEAK S/W RACING SOUTHEAST THROUGH THE DAKOTAS
AND MN MONDAY AND MONDAY NIGHT WITH THE LATEST RUNS MOVING IT/S WEAK
SURFACE LOW THROUGH IA AND FAVOR THE NORTHEAST CWFA FOR SOME LOW
POPS FOR LIGHT SNOW. JUST A QUICK SHOT OF COLD AIR IS EXPECTED
BEHIND THIS FEATURE WITH THE COLDEST TEMPS EXPECTED WEDNESDAY
MORNING WITH LOWS IN THE SINGLE DIGITS AND TEENS.
FOR THE END OF THE WEEK ANOTHER S/W MOVING OUT OF THE CANADIAN
ROCKIES WILL SEND A SURFACE LOW EAST ALONG THE U.S. CANADIAN
BORDER...DRAGGING A COLD FRONT THROUGH THE REGION WEDNESDAY NIGHT OR
THURSDAY MORNING. THE FRONT SHOULD MOVE THROUGH DRY WITH A LARGE
AREA OF HIGH PRESSURE OVER THE WESTERN GULF BLOCKING ANY MOISTURE
RETURN. BUT THE NORTHEAST COULD SEE SOME LIGHT SNOW IN THE CYCLONIC
FLOW AROUND THE SURFACE LOW AS IT MOVES INTO EASTERN CANADA THURSDAY
NIGHT AND FRIDAY. MODELS SHOW THE SYSTEM DRAGGING DOWN ANOTHER CHUNK
OF ARCTIC AIR WITH BOTH THE ECM AND GFS BRINGING H8 TEMPS AS COLD AS
-22C OVER THE AREA THURSDAY NIGHT. THIS COULD RESULT IN SUBZERO
TEMPERATURES OVER THE NORTH BY SATURDAY MORNING.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1208 PM CST FRI JAN 10 2014
LIFR/VLIFR CONDITIONS WILL CONTINUE THROUGH 12Z/11 WITH THE
POTENTIAL FOR CONDITIONS TO BE BELOW MINIMUMS. LOW PRESSURE WILL
TRACK UP THROUGH EASTERN IOWA THIS EVENING BEFORE MOVING INTO
WISCONSIN. FRONTAL PASSAGE AFTER 03Z/11 WILL BRING THE RISK OF
MIXED PRECIPITATION WITH A BRIEF PERIOD OF FZRA BEFORE CHANGING TO
SNOW. AFTER 12Z/11 CONDITIONS WILL SLOWLY IMPROVE TO MVFR.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...FREEZING RAIN ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR BENTON-
BUCHANAN-DELAWARE-DUBUQUE-JACKSON-JONES-LINN.
IL...FREEZING RAIN ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR JO DAVIESS-
STEPHENSON.
MO...NONE.
&&
$$
UPDATE...05
SYNOPSIS...08
SHORT TERM...08
LONG TERM...DLF
AVIATION...08
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
339 PM CST FRI JAN 10 2014
.UPDATE...
ISSUED AT 336 PM CST FRI JAN 10 2014
CALLS ARE NOW COMING IN REPORTING SLICK ROADS. THUS WILL HOIST A
FREEZING RAIN ADVISORY FOR LATE AFTERNOON AND EVENING. TEMPORAL
AND AREAL COVERAGE OF THE ADVISORY MAY NEED TO CHANGED THIS
EVENING.
&&
.SYNOPSIS...
ISSUED AT 248 PM CST FRI JAN 10 2014
12Z UA ANALYSIS HAS A LLJ RUNNING FROM TEXAS INTO WESTERN MISSOURI.
MOISTURE ASSOCIATED WITH THIS JET WAS IMPINGING UPON AN 850 MB WARM
FRONT RUNNING FROM KANSAS INTO SOUTHERN ILLINOIS. RADAR TRENDS
THROUGH MID AFTERNOON HAD A LARGE AREA OF RAIN FROM MISSOURI INTO
ILLINOIS WITH LIGHTER RAIN/DRIZZLE MIXED WITH SOME FREEZING
RAIN/DRIZZLE ACROSS IOWA.
18Z SFC ANALYSIS HAS A WEAK LOW NEAR KMHK WITH A WARM FRONT EAST
ALONG THE MISSOURI RIVER. THE COLD FRONT RAN FROM THE LOW INTO
SOUTHWEST OKLAHOMA. DEW POINTS WERE IN THE 20S AND 30S ACROSS THE
UPPER MIDWEST AND GREAT LAKES WITH 40S AND HIGHER FROM THE OHIO
VALLEY AND SOUTHERN PLAINS.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 248 PM CST FRI JAN 10 2014
BASED ON TRENDS FROM PRESSURE FALLS AND THE RAP MODEL...THE LOW
SHOULD PASS OVER THE FAR NORTHWEST AREA BETWEEN KALO AND KCID THIS
EVENING. WINDS WILL DECREASE AS THE LOW APPROACHES AND THE FOG IS
EXPECTED TO BECOME MORE WIDESPREAD. RIGHT NOW NO ADVISORY FOR DENSE
FOG IS PLANNED. HOWEVER...I WOULD NOT BE SURPRISED IF ONE IS NEEDED
AT SOME POINT DURING THE EVENING.
TEMPERATURES HAVE NOT BUDGED MUCH IN THE HIGHWAY 20 CORRIDOR FROM
KDBQ ON WEST. THUS THIS AREA IS RIGHT ON THE CUSP OF SEEING FREEZING
RAIN LATE THIS AFTERNOON AND EVENING AS LIFT CONTINUES TO INCREASE.
HOWEVER...THE TRACK OF THE LOW SHOULD ALLOW TEMPERATURES TO RISE
ABOUT ANOTHER DEGREE. FREEZING RAIN IS EXPECTED TO BE LOCALLY SPOTTY
OVER THE FOUR NORTHWEST COUNTIES AND POSSIBLY WESTERN DUBUQUE COUNTY
THROUGH MID EVENING.
ONCE THE LOW PASSES...COLD AIR WILL SLOWLY BEGIN TO MOVE INTO THE
AREA ALLOWING THE RAIN TO MIX WITH AND CHANGE TO SNOW FROM WEST TO
EAST OVERNIGHT. DURING THE CHANGE OVER...A BRIEF PERIOD OF FREEZING
RAIN WILL BE POSSIBLE. SNOW AMOUNTS WILL RANGE FROM A TRACE TO UNDER
AN INCH.
ON SATURDAY...LINGERING LIGHT SNOW WILL BE SEE OVER ROUGHLY THE
NORTHEAST/EAST HALF OF THE AREA DURING THE MORNING. OTHERWISE DRY
CONDITIONS ARE EXPECTED DURING THE DAY. SNOW AMOUNTS SATURDAY
MORNING WILL BE A DUSTING AT BEST.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 248 PM CST FRI JAN 10 2014
NEARLY ZONAL UPPER AIR FLOW WILL BE OVER THE AREA THE REST OF THE
WEEKEND THEN THE PATTERN CHANGES TO A RIDGE DOMINATED WESTERN U.S.
AND A MEAN TROF SETTING UP OVER THE EAST.
MILD CONDITIONS ARE ANTICIPATED FOR THE REGION SUNDAY AS UPPER
RIDGING BUILDS OVER THE AREA SATURDAY NIGHT INTO SUNDAY. IN THE LOW
LEVELS A SURFACE RIDGE WILL MOVE THROUGH THE REGION SATURDAY EVENING
FOLLOWED BY STRONG LOW LEVEL WAA AHEAD OF A TROF DIGGING INTO THE
SOUTHWEST U.S. AND A COLD FRONT OVER THE PLAINS. A LOW LEVEL
THERMAL RIDGE CROSSES THE MID MISSISSIPPI VALLEY SUNDAY WITH H8
TEMPS PEAKING IN THE +8 TO +10C RANGE DURING THE AFTERNOON. GOOD
MIXING IS ALSO SUGGESTED WITH A TIGHT SLP GRADIENT AHEAD OF THE COLD
FRONT. EVEN WITH THE SNOW COVER...WE SHOULD SEE HIGHS TOPPING OUT
IN THE MID 30S TO MID 40S. MODELS MOVE THE FRONT THROUGH THE REGION
WITH OUT ANY PRECIPITATION SUNDAY NIGHT. THIS LOOKS REASONABLE WITH
THE BETTER MOISTURE GETTING PUSHED OUT WELL AHEAD OF THE SYSTEM.
THERE IS SOME CONCERN MONDAY WITH THE LESS PHASED ECM SOLUTION
LIFTING A PIECE OF THE UPPER TROF OUT OF TEXAS...SENDING A SURFACE
LOW NORTHEAST THROUGH THE OHIO VALLEY. THE ECMS PRECIP SHIELD WITH
THIS FEATURE JUST MISSES THE SOUTHEAST CWFA MONDAY.
MODELS DO AGREE ON A WEAK S/W RACING SOUTHEAST THROUGH THE DAKOTAS
AND MN MONDAY AND MONDAY NIGHT WITH THE LATEST RUNS MOVING IT/S WEAK
SURFACE LOW THROUGH IA AND FAVOR THE NORTHEAST CWFA FOR SOME LOW
POPS FOR LIGHT SNOW. JUST A QUICK SHOT OF COLD AIR IS EXPECTED
BEHIND THIS FEATURE WITH THE COLDEST TEMPS EXPECTED WEDNESDAY
MORNING WITH LOWS IN THE SINGLE DIGITS AND TEENS.
FOR THE END OF THE WEEK ANOTHER S/W MOVING OUT OF THE CANADIAN
ROCKIES WILL SEND A SURFACE LOW EAST ALONG THE U.S. CANADIAN
BORDER...DRAGGING A COLD FRONT THROUGH THE REGION WEDNESDAY NIGHT OR
THURSDAY MORNING. THE FRONT SHOULD MOVE THROUGH DRY WITH A LARGE
AREA OF HIGH PRESSURE OVER THE WESTERN GULF BLOCKING ANY MOISTURE
RETURN. BUT THE NORTHEAST COULD SEE SOME LIGHT SNOW IN THE CYCLONIC
FLOW AROUND THE SURFACE LOW AS IT MOVES INTO EASTERN CANADA THURSDAY
NIGHT AND FRIDAY. MODELS SHOW THE SYSTEM DRAGGING DOWN ANOTHER CHUNK
OF ARCTIC AIR WITH BOTH THE ECM AND GFS BRINGING H8 TEMPS AS COLD AS
-22C OVER THE AREA THURSDAY NIGHT. THIS COULD RESULT IN SUBZERO
TEMPERATURES OVER THE NORTH BY SATURDAY MORNING.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1208 PM CST FRI JAN 10 2014
LIFR/VLIFR CONDITIONS WILL CONTINUE THROUGH 12Z/11 WITH THE
POTENTIAL FOR CONDITIONS TO BE BELOW MINIMUMS. LOW PRESSURE WILL
TRACK UP THROUGH EASTERN IOWA THIS EVENING BEFORE MOVING INTO
WISCONSIN. FRONTAL PASSAGE AFTER 03Z/11 WILL BRING THE RISK OF
MIXED PRECIPITATION WITH A BRIEF PERIOD OF FZRA BEFORE CHANGING TO
SNOW. AFTER 12Z/11 CONDITIONS WILL SLOWLY IMPROVE TO MVFR.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...FREEZING RAIN ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR BENTON-
BUCHANAN-DELAWARE-DUBUQUE-JONES-LINN.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...08
SYNOPSIS...08
SHORT TERM...08
LONG TERM...DLF
AVIATION...08
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
250 PM CST FRI JAN 10 2014
.SYNOPSIS...
ISSUED AT 248 PM CST FRI JAN 10 2014
12Z UA ANALYSIS HAS A LLJ RUNNING FROM TEXAS INTO WESTERN MISSOURI.
MOISTURE ASSOCIATED WITH THIS JET WAS IMPINGING UPON AN 850 MB WARM
FRONT RUNNING FROM KANSAS INTO SOUTHERN ILLINOIS. RADAR TRENDS
THROUGH MID AFTERNOON HAD A LARGE AREA OF RAIN FROM MISSOURI INTO
ILLINOIS WITH LIGHTER RAIN/DRIZZLE MIXED WITH SOME FREEZING
RAIN/DRIZZLE ACROSS IOWA.
18Z SFC ANALYSIS HAS A WEAK LOW NEAR KMHK WITH A WARM FRONT EAST
ALONG THE MISSOURI RIVER. THE COLD FRONT RAN FROM THE LOW INTO
SOUTHWEST OKLAHOMA. DEW POINTS WERE IN THE 20S AND 30S ACROSS THE
UPPER MIDWEST AND GREAT LAKES WITH 40S AND HIGHER FROM THE OHIO
VALLEY AND SOUTHERN PLAINS.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 248 PM CST FRI JAN 10 2014
BASED ON TRENDS FROM PRESSURE FALLS AND THE RAP MODEL...THE LOW
SHOULD PASS OVER THE FAR NORTHWEST AREA BETWEEN KALO AND KCID THIS
EVENING. WINDS WILL DECREASE AS THE LOW APPROACHES AND THE FOG IS
EXPECTED TO BECOME MORE WIDESPREAD. RIGHT NOW NO ADVISORY FOR DENSE
FOG IS PLANNED. HOWEVER...I WOULD NOT BE SURPRISED IF ONE IS NEEDED
AT SOME POINT DURING THE EVENING.
TEMPERATURES HAVE NOT BUDGED MUCH IN THE HIGHWAY 20 CORRIDOR FROM
KDBQ ON WEST. THUS THIS AREA IS RIGHT ON THE CUSP OF SEEING FREEZING
RAIN LATE THIS AFTERNOON AND EVENING AS LIFT CONTINUES TO INCREASE.
HOWEVER...THE TRACK OF THE LOW SHOULD ALLOW TEMPERATURES TO RISE
ABOUT ANOTHER DEGREE. FREEZING RAIN IS EXPECTED TO BE LOCALLY SPOTTY
OVER THE FOUR NORTHWEST COUNTIES AND POSSIBLY WESTERN DUBUQUE COUNTY
THROUGH MID EVENING.
ONCE THE LOW PASSES...COLD AIR WILL SLOWLY BEGIN TO MOVE INTO THE
AREA ALLOWING THE RAIN TO MIX WITH AND CHANGE TO SNOW FROM WEST TO
EAST OVERNIGHT. DURING THE CHANGE OVER...A BRIEF PERIOD OF FREEZING
RAIN WILL BE POSSIBLE. SNOW AMOUNTS WILL RANGE FROM A TRACE TO UNDER
AN INCH.
ON SATURDAY...LINGERING LIGHT SNOW WILL BE SEE OVER ROUGHLY THE
NORTHEAST/EAST HALF OF THE AREA DURING THE MORNING. OTHERWISE DRY
CONDITIONS ARE EXPECTED DURING THE DAY. SNOW AMOUNTS SATURDAY
MORNING WILL BE A DUSTING AT BEST.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 248 PM CST FRI JAN 10 2014
NEARLY ZONAL UPPER AIR FLOW WILL BE OVER THE AREA THE REST OF THE
WEEKEND THEN THE PATTERN CHANGES TO A RIDGE DOMINATED WESTERN U.S.
AND A MEAN TROF SETTING UP OVER THE EAST.
MILD CONDITIONS ARE ANTICIPATED FOR THE REGION SUNDAY AS UPPER
RIDGING BUILDS OVER THE AREA SATURDAY NIGHT INTO SUNDAY. IN THE LOW
LEVELS A SURFACE RIDGE WILL MOVE THROUGH THE REGION SATURDAY EVENING
FOLLOWED BY STRONG LOW LEVEL WAA AHEAD OF A TROF DIGGING INTO THE
SOUTHWEST U.S. AND A COLD FRONT OVER THE PLAINS. A LOW LEVEL
THERMAL RIDGE CROSSES THE MID MISSISSIPPI VALLEY SUNDAY WITH H8
TEMPS PEAKING IN THE +8 TO +10C RANGE DURING THE AFTERNOON. GOOD
MIXING IS ALSO SUGGESTED WITH A TIGHT SLP GRADIENT AHEAD OF THE COLD
FRONT. EVEN WITH THE SNOW COVER...WE SHOULD SEE HIGHS TOPPING OUT
IN THE MID 30S TO MID 40S. MODELS MOVE THE FRONT THROUGH THE REGION
WITH OUT ANY PRECIPITATION SUNDAY NIGHT. THIS LOOKS REASONABLE WITH
THE BETTER MOISTURE GETTING PUSHED OUT WELL AHEAD OF THE SYSTEM.
THERE IS SOME CONCERN MONDAY WITH THE LESS PHASED ECM SOLUTION
LIFTING A PIECE OF THE UPPER TROF OUT OF TEXAS...SENDING A SURFACE
LOW NORTHEAST THROUGH THE OHIO VALLEY. THE ECMS PRECIP SHIELD WITH
THIS FEATURE JUST MISSES THE SOUTHEAST CWFA MONDAY.
MODELS DO AGREE ON A WEAK S/W RACING SOUTHEAST THROUGH THE DAKOTAS
AND MN MONDAY AND MONDAY NIGHT WITH THE LATEST RUNS MOVING IT/S WEAK
SURFACE LOW THROUGH IA AND FAVOR THE NORTHEAST CWFA FOR SOME LOW
POPS FOR LIGHT SNOW. JUST A QUICK SHOT OF COLD AIR IS EXPECTED
BEHIND THIS FEATURE WITH THE COLDEST TEMPS EXPECTED WEDNESDAY
MORNING WITH LOWS IN THE SINGLE DIGITS AND TEENS.
FOR THE END OF THE WEEK ANOTHER S/W MOVING OUT OF THE CANADIAN
ROCKIES WILL SEND A SURFACE LOW EAST ALONG THE U.S. CANADIAN
BORDER...DRAGGING A COLD FRONT THROUGH THE REGION WEDNESDAY NIGHT OR
THURSDAY MORNING. THE FRONT SHOULD MOVE THROUGH DRY WITH A LARGE
AREA OF HIGH PRESSURE OVER THE WESTERN GULF BLOCKING ANY MOISTURE
RETURN. BUT THE NORTHEAST COULD SEE SOME LIGHT SNOW IN THE CYCLONIC
FLOW AROUND THE SURFACE LOW AS IT MOVES INTO EASTERN CANADA THURSDAY
NIGHT AND FRIDAY. MODELS SHOW THE SYSTEM DRAGGING DOWN ANOTHER CHUNK
OF ARCTIC AIR WITH BOTH THE ECM AND GFS BRINGING H8 TEMPS AS COLD AS
-22C OVER THE AREA THURSDAY NIGHT. THIS COULD RESULT IN SUBZERO
TEMPERATURES OVER THE NORTH BY SATURDAY MORNING.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1208 PM CST FRI JAN 10 2014
LIFR/VLIFR CONDITIONS WILL CONTINUE THROUGH 12Z/11 WITH THE
POTENTIAL FOR CONDITIONS TO BE BELOW MINIMUMS. LOW PRESSURE WILL
TRACK UP THROUGH EASTERN IOWA THIS EVENING BEFORE MOVING INTO
WISCONSIN. FRONTAL PASSAGE AFTER 03Z/11 WILL BRING THE RISK OF
MIXED PRECIPITATION WITH A BRIEF PERIOD OF FZRA BEFORE CHANGING TO
SNOW. AFTER 12Z/11 CONDITIONS WILL SLOWLY IMPROVE TO MVFR.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...08
SHORT TERM...08
LONG TERM...DLF
AVIATION...08
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1204 PM CST Fri Jan 10 2014
...Updated Aviation Section...
.SHORT TERM...(Today and tonight)
ISSUED AT 1251 AM CST FRI JAN 10 2014
This morning:
Immediate near term concern is fog. Issued a dense fog advisory earlier
based off HRRR and WRF visibilities as well a trend in the observations.
Winds have remained elevated as the warm sector has spread across SW
Kansas early this morning. Will continue with the advisory as is and
later shifts can cancel or trim counties as seen fit. Downslope/dry
air advection is expected later today in the wake of a passing cold
front, which should scour low level moisture out.
Today:
A synoptic trof ushering in the passage of said front will move across
the region through the day. Mesoscale and global models have a hint
of QPF across NW Kansas at the base of the 400 hPa PVU hook. Not overly
impressive for my counties as isentropic downglide develops in earnest
with the passage of the trof. Will go with ghost probability percentage
precipitation points for now up north. Otherwise, Boise verification
shows a bias in recent temperatures forecasts, and will trend with
the GEM for now, which has been performing better recently. Low 40sF
northwest to upper 40sF southeast.
Tonight:
Westerly to northwesterly flow at the surface and a dry northwesterly
flow aloft will continue tonight. Continued dry air advection with resultant
decreasing dewpoints and weaker winds favor cooler minimum temperatures
through the overnight - 20sF.
.LONG TERM...(Saturday through Thursday)
ISSUED AT 320 AM CST FRI JAN 10 2014
No precipitation is anticipated for the days 2 through 7 period. No
strong upper level feature will be crossing the plains, and a couple
of fronts will pass through dry.
Saturday will see an upper level trough over the Mississippi Valley,
and the 500mb flow from the northwest across western Kansas. A
broad ridge aloft will drift across the plains, bringing mostly
sunny skies and warming temperatures this weekend. Saturday will see
highs in the middle 50s, and then warming into the mid 50s to
lower 60s on Sunday. The upper flow pattern will turn to zonal on
Monday, bringing a few upper level clouds and just a slight cool
down to temperatures. Monday`s highs will range in the lower 50s
in central Kansas to near the mid 50s along the Oklahoma border.
Tuesday will bring a cool down, with highs in the upper 40s north
of I-70 to the lower 50s near Meade and Ashland. Then we will
return to a down slope, northwesterly flow aloft Wednesday. A warm
front should shoot northeastward through western Kansas Tuesday
night, and bring maximum temperatures in the middle 50s for most
locations in southwestern Kansas on Wednesday. Minimum temperatures
throughout the Saturday through Friday period will average from the
middle 20s to the middle 30s.
Surface winds will generally be northwest 15 mph gusting 25 mph
during most afternoons. The winds will die down in the evening, and
be less than 10 mph during the night time periods. The only night
that will be an exception to that will be Tuesday night behind the
frontal passage, with north winds at 15 to 20 mph.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
ISSUED AT 1155 AM CST FRI JAN 10 2014
An upper disturbance and associated surface low over Kansas this
early afternoon, will shift quickly east into the Mississippi
Valley by early evening. This will move a band of light snow with
mvfr ceilings over north central Kansas this morning, east of Hays
by mid afternoon with an unlimited ceiling and visibility
prevailing through the remainder of the period. Winds will
increase behind the exiting surface low and may approach sustained
speeds of 25 knots at DDC and HYS terminals but confidence is not
high enough at this point to increase speeds to this level.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 46 24 57 30 / 10 0 0 0
GCK 44 22 56 29 / 0 0 0 0
EHA 48 26 62 33 / 0 0 0 0
LBL 48 21 60 31 / 0 0 0 0
HYS 44 24 54 29 / 90 0 0 0
P28 50 25 59 31 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...Sugden
SHORT TERM...Sugden
LONG TERM...Burke
AVIATION...AJohnson
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
331 AM CST Fri Jan 10 2014
...Updated for the long term discussion...
.SYNOPSIS...
ISSUED AT 1020 PM CST THU JAN 9 2014
The 10.00Z 250 hPa map showed strong NNW flow across the Pacific Northwest
with magnitudes in the 120-130 kt range. Downstream, SW to W flow continued
across the rest of the United States with magnitudes in the 90-100 kt
range. At 500 hPa, a trof was moving across the central and northern
Rockies. The KDDC raob showed a veering/warm air advection pattern in
the low levels ahead of the aforementioned synoptic trof. At the sfc,
a frontal boundary extended across the southern High Plains. Low level
moisture was advecting northward across the region.
&&
.SHORT TERM...(Today and tonight)
ISSUED AT 1251 AM CST FRI JAN 10 2014
This morning:
Immediate near term concern is fog. Issued a dense fog advisory earlier
based off HRRR and WRF visibilities as well a trend in the observations.
Winds have remained elevated as the warm sector has spread across SW
Kansas early this morning. Will continue with the advisory as is and
later shifts can cancel or trim counties as seen fit. Downslope/dry
air advection is expected later today in the wake of a passing cold
front, which should scour low level moisture out.
Today:
A synoptic trof ushering in the passage of said front will move across
the region through the day. Mesoscale and global models have a hint
of QPF across NW Kansas at the base of the 400 hPa PVU hook. Not overly
impressive for my counties as isentropic downglide develops in earnest
with the passage of the trof. Will go with ghost probability percentage
precipitation points for now up north. Otherwise, Boise verification
shows a bias in recent temperatures forecasts, and will trend with
the GEM for now, which has been performing better recently. Low 40sF
northwest to upper 40sF southeast.
Tonight:
Westerly to northwesterly flow at the surface and a dry northwesterly
flow aloft will continue tonight. Continued dry air advection with resultant
decreasing dewpoints and weaker winds favor cooler minimum temperatures
through the overnight - 20sF.
.LONG TERM...(Saturday through Thursday)
ISSUED AT 320 AM CST FRI JAN 10 2014
No precipitation is anticipated for the days 2 through 7 period. No
strong upper level feature will be crossing the plains, and a couple
of fronts will pass through dry.
Saturday will see an upper level trough over the Mississippi Valley,
and the 500mb flow from the northwest across western Kansas. A
broad ridge aloft will drift across the plains, bringing mostly
sunny skies and warming temperatures this weekend. Saturday will see
highs in the middle 50s, and then warming into the mid 50s to
lower 60s on Sunday. The upper flow pattern will turn to zonal on
Monday, bringing a few upper level clouds and just a slight cool
down to temperatures. Monday`s highs will range in the lower 50s
in central Kansas to near the mid 50s along the Oklahoma border.
Tuesday will bring a cool down, with highs in the upper 40s north
of I-70 to the lower 50s near Meade and Ashland. Then we will
return to a down slope, northwesterly flow aloft Wednesday. A warm
front should shoot northeastward through western Kansas Tuesday
night, and bring maximum temperatures in the middle 50s for most
locations in southwestern Kansas on Wednesday. Minimum temperatures
throughout the Saturday through Friday period will average from the
middle 20s to the middle 30s.
Surface winds will generally be northwest 15 mph gusting 25 mph
during most afternoons. The winds will die down in the evening, and
be less than 10 mph during the night time periods. The only night
that will be an exception to that will be Tuesday night behind the
frontal passage, with north winds at 15 to 20 mph.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
ISSUED AT 1100 PM CST THU JAN 9 2014
Cigs will continue to decrease through the overnight in association
with stratus and fog. VFR cigs expected by mid morning as drier
air advects in the wake of a frontal passage. Southerly winds will
veer northwesterly 10-20 kt.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 46 25 55 30 / 0 0 0 0
GCK 44 26 56 29 / 0 0 0 0
EHA 45 25 58 33 / 0 0 0 0
LBL 45 23 58 31 / 0 0 0 0
HYS 45 25 53 29 / 10 0 0 0
P28 48 28 56 31 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY until 9 AM CST this morning FOR KSZ030-031-
043>046-063>066-076>081-087>090.
&&
$$
SYNOPSIS...Sugden
SHORT TERM...Sugden
LONG TERM...Burke
AVIATION...Sugden
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1256 AM MST FRI JAN 10 2014
.SHORT TERM...(THIS AFTERNOON THROUGH FRIDAY)
ISSUED AT 106 PM MST THU JAN 9 2014
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOW A PROGRESSIVE ZONAL
PATTERN IN PLACE ACROSS THE CONUS WITH A SPLIT TROUGH OVER THE
WESTERN US. PV HEIGHT MINIMUM IS OVER SOUTHERN IDAHO WITH
ENHANCEMENT AHEAD OF THIS FEATURE ON WV IMAGERY ACROSS WYOMING.
THIS AFTERNOON...FOG HAS LIFTED OVER THE CWA...HOWEVER THERE
CONTINUES TO BE SEVERAL AREAS OF LOW STRATUS LINGERING ACROSS THE
REGION...WITH THE MOST EXTENSIVE AREA OVER CENTRAL KANSAS. WHILE
SURFACE TROUGH HAS SHIFTED EAST AND ALL INDICATIONS BY SHORT RANGE
GUIDANCE TEMPS HAVE MODIFIED ALOFT...WITH COLD POOL SHIFTING EAST.
THERE HAS BEEN LESS OF A REFLECTION OF THE CHANGE IN AIR MASS WITH
TEMPS SLOW TO RECOVER SO FAR. WILL LIKELY NEED TO KEEP AN EYE ON
TRENDS...BUT I BUMPED EXPECTED HIGHS DOWN A LITTLE TO MATCH THE
SLOWER RATE OF WARMING THIS AFTERNOON.
TONIGHT-FRIDAY...AS UPPER TROUGH SHIFTS EAST TONIGHT BEST
FORCING/MOISTURE WILL REMAIN WELL EAST OF THE CWA. BL MOISTURE WILL
REMAIN HIGH HOWEVER OVER EASTERN LOCATIONS WHERE FOG/STRATUS HAVE
BEEN SLOWER TO ERODE AND FURTHER FOG/STRATUS DEVELOPMENT IS LIKELY.
AS THE UPPER LEVEL SYSTEM SHIFTS EAST ANY FOG THAT DOES DEVELOP
SHOULD QUICKLY PUSH EAST AS GUSTY NW WINDS DRY OUT THE BL. WHILE
FORCING WILL BE INCREASING AS NOSE OF H3 JET ON THE BACK SIDE OF THE
UPPER LOW MOVES ACROSS OUR CWA LATE TONIGHT THROUGH
FRIDAY...MOISTURE PROFILES CONTINUE TO BE UNIMPRESSIVE THROUGH MOST
OF THESE PERIODS. 15-18Z MODEL SOUNDINGS ARE MORE IMPRESSIVE AND
WOULD SUPPORT PRECIPITATION. I KEPT POP MENTION TO SLIGHT CHANCE
STARTING AFTER 06Z TONIGHT IN THE NW AND OVERSPREADING MOST OF THE
CWA THROUGH FRIDAY. ANY PRECIP SHOULD START OUT AS LIGHT SNOW MIXING
WITH AND CHANGING TO RAIN DURING THE DAYTIME PERIOD. DUE TO THE
QUICK NATURE OF THE SYSTEM AND GENERAL LACK OF MOISTURE AMOUNTS
SHOULD BE VERY LIGHT.
.LONG TERM...(MONDAY THROUGH NEXT FRIDAY)
ISSUED AT 1253 AM MST FRI JAN 10 2014
THE LONG TERM PERIOD WILL BE QUIET UNDER THE INFLUENCE OF A RIDGE
CENTERED OVER THE GREAT BASIN. A COUPLE OF FRONTAL PASSAGES
ASSOCIATED WITH SHORTWAVE TROUGHS EMBEDDED IN THE NORTHWEST FLOW
WILL RESULT IN BRIEF COOL DOWNS...BUT OVERALL TEMPERATURES WILL BE
ABOVE NORMAL THROUGH THE PERIOD. NO PRECIPITATION IS EXPECTED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1005 PM MST THU JAN 9 2014
KGLD...WITHIN THE PAST HOUR OR TWO WINDS HAVE BECOME MORE
SOUTHERLY VS SOUTHWESTERLY WHICH HAS ALLOWED LOW LEVEL STRATUS/FOG
AND MVFR CONDITIONS TO ADVANCE FURTHER WEST THEN PREVIOUSLY
EXPECTED. THESE CONDITIONS EXPECTED THROUGH APPROXIMATELY 9-10Z
BEFORE SOUTHWEST WINDS RE-ESTABLISH THEMSELVES AND PUSH IFR/LIFR
CONDITIONS TO THE EAST AND THUS BRING VFR CONDITIONS BACK AND
CONTINUE THROUGH THE REST OF THE TAF PERIOD. LIKE PREVIOUS
DISCUSSION GUSTY NORTHWEST WINDS EXPECTED BY 11Z AND CONTINUE
THROUGH 23Z BEFORE DECREASING AROUND 10KTS FROM THE WEST/NORTHWEST
FROM 23Z-06Z. MAY SEE A SNOW SHOWER OR FLURRIES MOVE THROUGH IN THE
11Z-15Z TIMEFRAME AS WELL AS A WEATHER DISTURBANCE MOVES THROUGH.
KMCK...MVFR VIS ONGOING WITH LIGHT SOUTHEAST WINDS. THESE
CONDITIONS EXPECTED TO CONTINUE THROUGH 14Z BEFORE NORTHWEST WINDS
OF 15-20KTS WITH HIGHER GUSTS MOVE IN...PUSHING MVFR AIRMASS OUT.
HOWEVER...ANOTHER DISTURBANCE AND MVFR CIGS MOVE IN DURING THE
16Z-20Z TIMEFRAME BRINGING A RETURN TO MVFR CONDITIONS. BY 23Z VFR
CONDITIONS EXPECTED THROUGH THE REST OF THE TAF PERIOD ALONG WITH
WEST/NORTHWEST WINDS AROUND 11KTS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...024
AVIATION...99
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1251 AM CST Fri Jan 10 2014
...Update to short term discussion...
.SYNOPSIS...
ISSUED AT 1020 PM CST THU JAN 9 2014
The 10.00Z 250 hPa map showed strong NNW flow across the Pacific Northwest
with magnitudes in the 120-130 kt range. Downstream, SW to W flow continued
across the rest of the United States with magnitudes in the 90-100 kt
range. At 500 hPa, a trof was moving across the central and northern
Rockies. The KDDC raob showed a veering/warm air advection pattern in
the low levels ahead of the aforementioned synoptic trof. At the sfc,
a frontal boundary extended across the southern High Plains. Low level
moisture was advecting northward across the region.
&&
.SHORT TERM...(Today and tonight)
ISSUED AT 1251 AM CST FRI JAN 10 2014
This morning:
Immediate near term concern is fog. Issued a dense fog advisory earlier
based off HRRR and WRF visibilities as well a trend in the observations.
Winds have remained elevated as the warm sector has spread across SW
Kansas early this morning. Will continue with the advisory as is and
later shifts can cancel or trim counties as seen fit. Downslope/dry
air advection is expected later today in the wake of a passing cold
front, which should scour low level moisture out.
Today:
A synoptic trof ushering in the passage of said front will move across
the region through the day. Mesoscale and global models have a hint
of QPF across NW Kansas at the base of the 400 hPa PVU hook. Not overly
impressive for my counties as isentropic downglide develops in earnest
with the passage of the trof. Will go with ghost probability percentage
precipitation points for now up north. Otherwise, Boise verification
shows a bias in recent temperatures forecasts, and will trend with
the GEM for now, which has been performing better recently. Low 40sF
northwest to upper 40sF southeast.
Tonight:
Westerly to northwesterly flow at the surface and a dry northwesterly
flow aloft will continue tonight. Continued dry air advection with resultant
decreasing dewpoints and weaker winds favor cooler minimum temperatures
through the overnight - 20sF.
.LONG TERM...(Friday night through Thursday)
ISSUED AT 352 PM CST THU JAN 9 2014
Shortwave ridging will progress across the high plains Saturday as
the next upper level system moves onshore into the western United
States. Highs should reach into the 50s given the lee troughing and
south to southwesterly surface winds. The system over the western
USA will progress across the high plains on Sunday; but given the
progressiveness of the system and lack of rich low to mid level
moisture, precipitation is not expected.
Fair weather can be expected Monday through Wednesday as
northwesterly mid to upper level flow develops over the plains
region. High temperatures will be in the 50s Monday ahead of a cold
front, then back into the upper 40s to lower 50s Tuesday behind the
weak front, and then up into the 50s by Wednesday as surface
troughing and southwesterly winds return.
The next progressive upper level system in northwesterly flow
will progress across the plains region by Wednesday night and early
Thursday. Progressive systems in January usually pass dry, and this
should be no exception. Behind the associated weak cold front, high
temperatures will fall back to the upper 40s to near 50F.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
ISSUED AT 1100 PM CST THU JAN 9 2014
Cigs will continue to decrease through the overnight in association
with stratus and fog. VFR cigs expected by mid morning as drier
air advects in the wake of a frontal passage. Southerly winds will
veer northwesterly 10-20 kt.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 46 25 55 30 / 0 0 0 0
GCK 44 26 56 29 / 0 0 0 0
EHA 45 25 58 33 / 0 0 0 0
LBL 45 23 58 31 / 0 0 0 0
HYS 45 25 53 29 / 10 0 0 0
P28 48 28 56 31 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY until 9 AM CST this morning FOR KSZ030-031-
043>046-063>066-076>081-087>090.
&&
$$
SYNOPSIS...Sugden
SHORT TERM...Sugden
LONG TERM...Finch
AVIATION...Sugden
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1005 PM MST THU JAN 9 2014
.SHORT TERM...(THIS AFTERNOON THROUGH FRIDAY)
ISSUED AT 106 PM MST THU JAN 9 2014
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOW A PROGRESSIVE ZONAL
PATTERN IN PLACE ACROSS THE CONUS WITH A SPLIT TROUGH OVER THE
WESTERN US. PV HEIGHT MINIMUM IS OVER SOUTHERN IDAHO WITH
ENHANCEMENT AHEAD OF THIS FEATURE ON WV IMAGERY ACROSS WYOMING.
THIS AFTERNOON...FOG HAS LIFTED OVER THE CWA...HOWEVER THERE
CONTINUES TO BE SEVERAL AREAS OF LOW STRATUS LINGERING ACROSS THE
REGION...WITH THE MOST EXTENSIVE AREA OVER CENTRAL KANSAS. WHILE
SURFACE TROUGH HAS SHIFTED EAST AND ALL INDICATIONS BY SHORT RANGE
GUIDANCE TEMPS HAVE MODIFIED ALOFT...WITH COLD POOL SHIFTING EAST.
THERE HAS BEEN LESS OF A REFLECTION OF THE CHANGE IN AIR MASS WITH
TEMPS SLOW TO RECOVER SO FAR. WILL LIKELY NEED TO KEEP AN EYE ON
TRENDS...BUT I BUMPED EXPECTED HIGHS DOWN A LITTLE TO MATCH THE
SLOWER RATE OF WARMING THIS AFTERNOON.
TONIGHT-FRIDAY...AS UPPER TROUGH SHIFTS EAST TONIGHT BEST
FORCING/MOISTURE WILL REMAIN WELL EAST OF THE CWA. BL MOISTURE WILL
REMAIN HIGH HOWEVER OVER EASTERN LOCATIONS WHERE FOG/STRATUS HAVE
BEEN SLOWER TO ERODE AND FURTHER FOG/STRATUS DEVELOPMENT IS LIKELY.
AS THE UPPER LEVEL SYSTEM SHIFTS EAST ANY FOG THAT DOES DEVELOP
SHOULD QUICKLY PUSH EAST AS GUSTY NW WINDS DRY OUT THE BL. WHILE
FORCING WILL BE INCREASING AS NOSE OF H3 JET ON THE BACK SIDE OF THE
UPPER LOW MOVES ACROSS OUR CWA LATE TONIGHT THROUGH
FRIDAY...MOISTURE PROFILES CONTINUE TO BE UNIMPRESSIVE THROUGH MOST
OF THESE PERIODS. 15-18Z MODEL SOUNDINGS ARE MORE IMPRESSIVE AND
WOULD SUPPORT PRECIPITATION. I KEPT POP MENTION TO SLIGHT CHANCE
STARTING AFTER 06Z TONIGHT IN THE NW AND OVERSPREADING MOST OF THE
CWA THROUGH FRIDAY. ANY PRECIP SHOULD START OUT AS LIGHT SNOW MIXING
WITH AND CHANGING TO RAIN DURING THE DAYTIME PERIOD. DUE TO THE
QUICK NATURE OF THE SYSTEM AND GENERAL LACK OF MOISTURE AMOUNTS
SHOULD BE VERY LIGHT.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 220 PM MST THU JAN 9 2014
FRIDAY NIGHT A STRONG 300MB JET STREAK WILL MOVE IN BEHIND THE
EXITING TROUGH AXIS. AS THE JET STREAK MOVES IN THE LEFT EXIT OF
THE JET STREAK WILL MOVE OVER THE AREA. WITH SATURATED MID LEVELS
REMAINING BEHIND THE TROUGH AXIS AND A 500MB SHORT WAVE TROUGH ALSO
MOVING OVER THE AREA...CANNOT COMPLETELY RULE OUT SOME LINGERING
LIGHT SNOW DURING THE NIGHT. BEHIND THE 500MB SHORT WAVE TROUGH THE
ENVIRONMENT WILL DRY OUT AND SUBSIDENCE WILL MOVE IN.
SATURDAY AN UPPER LEVEL RIDGE WILL MOVE THROUGH DURING THE DAY AND
THE ENVIRONMENT WILL CONTINUE TO DRY OUT. BEHIND THE RIDGE AXIS
WARMER AIR WILL ADVECT OVER THE AREA ALLOWING TEMPERATURES TO WARM.
SATURDAY NIGHT A SURFACE TROUGH WILL MOVE THROUGH THE AREA. DUE TO
THE DRY ENVIRONMENT IN PLACE AM NOT ANTICIPATING ANYTHING MORE THAN
HIGH CLOUDS TO ACCOMPANY THE TROUGH PASSAGE.
FOR SUNDAY THROUGH THURSDAY WARMER AND WINDY WILL BE THE PRIMARY
WEATHER THEME. AN UPPER LEVEL SHORT WAVE TROUGH WILL MOVE OVER THE
AREA SUNDAY WHICH MAY BRING SOME MINIMAL CHANCES FOR RAINFALL TO
PARTS OF THE AREA. HOWEVER MODELS ARE SUGGESTING A SPLIT UPPER
LEVEL JET WHICH USUALLY IS NOT FAVORABLE FOR DEVELOPING PRECIP. OVER
THE TRI-STATE AREA. BEHIND THE TROUGH THE UPPER LEVEL FLOW WILL
REMAIN FROM THE NORTHWEST THROUGH THE PERIOD AS AN UPPER LEVEL RIDGE
BUILDS OVER THE WESTERN CONUS. A COLD FRONT WILL MOVE THROUGH
TUESDAY AND THURSDAY ALONG WITH AN UPPER LEVEL SHORT WAVE TROUGH.
HOWEVER THE MAJORITY OF THE JET DYNAMICS WITH THE SHORT WAVE TROUGH
WILL BE OVER THE GREAT LAKES. AS SUCH BELIEVE THE AREA WILL BE DRY
WITH BOTH FRONTAL PASSAGES. WITH A STRONG NORTHWEST FLOW PATTERN
OVER THE AREA THIS PERIOD WILL BE WINDY.
HIGH TEMPERATURES FOR THE PERIOD WILL BE ABOVE NORMAL EXCEPT FOR
TUESDAY AND THURSDAY WHEN A COLD FRONT MOVES THROUGH. LOW
TEMPERATURES FOR THE PERIOD WILL BE NEAR NORMAL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1005 PM MST THU JAN 9 2014
KGLD...WITHIN THE PAST HOUR OR TWO WINDS HAVE BECOME MORE
SOUTHERLY VS SOUTHWESTERLY WHICH HAS ALLOWED LOW LEVEL STRATUS/FOG
AND MVFR CONDITIONS TO ADVANCE FURTHER WEST THEN PREVIOUSLY
EXPECTED. THESE CONDITIONS EXPECTED THROUGH APPROXIMATELY 9-10Z
BEFORE SOUTHWEST WINDS RE-ESTABLISH THEMSELVES AND PUSH IFR/LIFR
CONDITIONS TO THE EAST AND THUS BRING VFR CONDITIONS BACK AND
CONTINUE THROUGH THE REST OF THE TAF PERIOD. LIKE PREVIOUS
DISCUSSION GUSTY NORTHWEST WINDS EXPECTED BY 11Z AND CONTINUE
THROUGH 23Z BEFORE DECREASING AROUND 10KTS FROM THE WEST/NORTHWEST
FROM 23Z-06Z. MAY SEE A SNOW SHOWER OR FLURRIES MOVE THROUGH IN THE
11Z-15Z TIMEFRAME AS WELL AS A WEATHER DISTURBANCE MOVES THROUGH.
KMCK...MVFR VIS ONGOING WITH LIGHT SOUTHEAST WINDS. THESE
CONDITIONS EXPECTED TO CONTINUE THROUGH 14Z BEFORE NORTHWEST WINDS
OF 15-20KTS WITH HIGHER GUSTS MOVE IN...PUSHING MVFR AIRMASS OUT.
HOWEVER...ANOTHER DISTURBANCE AND MVFR CIGS MOVE IN DURING THE
16Z-20Z TIMEFRAME BRINGING A RETURN TO MVFR CONDITIONS. BY 23Z VFR
CONDITIONS EXPECTED THROUGH THE REST OF THE TAF PERIOD ALONG WITH
WEST/NORTHWEST WINDS AROUND 11KTS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...JTL
AVIATION...99
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
948 PM EST Sat Jan 11 2014
...Forecast Update...
Issued at 940 PM EST Sat Jan 11 2014
Updated the forecast to tweak sky cover, temps, and dewpts. Also
removed patchy fog from south central KY. Observations revealed a
sfc trough over central IL/central IN moving southeast along with an
upper level shortwave on the back side of an upper trough which was
exiting the region. Latest RAP and gridded LAMP guidance indicates
we`ll see low clouds over southern Indiana as well as north central
and east central KY late tonight as these features pass through the
area. Tweaked skies grids to match the latest high-res models.
Took patchy fog out of south central KY since it looks like the
atmosphere will remain too mixy with the trough and shortwave
passing through and slightly drier air will advect in behind the
trough. Most high-res models agree, but the 0Z NAM does not.
Therefore, will need to keep an eye on things overnight in case the
NAM soln is correct.
Issued at 645 PM EST Sat Jan 11 2014
Did a quick forecast update to refresh temps/dewpts and adjust sky
cover some. Low clouds are making quicker progress eastward than
previously forecast. Still looks like we`ll see low clouds
re-enforced late tonight over southeast Indiana and portions of
north and east central KY late tonight as a final shortwave dives
down on the back side of the upper trough exiting the region.
.SHORT TERM (Now through Sunday Night)...
Issued at 245 PM EST Sat Jan 11 2014
The cold front has moved through the region this afternoon and
temperatures have fallen into the 40s with gusty westerly winds. For
tonight the upper level trough will swing across the area. Models do
show a shallow layer of moisture will remain, with perhaps enough
for light drizzle tonight across far northern portions of the
forecast area, though certainty for this is not high. For now just
have higher cloud cover across the northern portions of the area.
The other question will be the potential for some patchy fog across
south central Kentucky where clouds do clear out. This will be
highly dependent on cloud cover and winds. Temperatures tonight will
fall to near or just below freezing.
For tomorrow a progressive upper level and surface ridge will scoot
across the lower Ohio Valley. This will bring mostly sunny skies and
temperatures rising into the upper 40s to lower 50s. Clouds will be
on the increase tomorrow night as the next system begins to approach
the area, though we should stay dry overnight. Tempertures will fall
into the upper 30s to lower 40s.
.LONG TERM (Monday through Saturday)...
Issued at 255 PM EST Sat Jan 11 2014
Progressive but still somewhat amplified pattern will evolve into a
mean eastern CONUS trough by the end of the week, with an overall
trend back to below-normal temps.
The first in a series of disturbances will move through the Ohio
Valley late Monday, with a southern stream wave as the main player.
Some uncertainty over the degree of phasing with the northern
stream, but it is worth noting the GFS and ECMWF are in decent
agreement that phasing will occur, with the less phased NAM as an
outlier. Therefore will continue to favor the wetter solution with
likely POPs in south-central and east-central Kentucky, tapering
down to 30-40% over southern Indiana. Temps will be easily warm
enough to keep this all rain, but there is no instability to support
thunder with this system. Cold air will mainly be chasing the
moisture out of here Monday night, but we could see a changeover to
snow before the precip ends, mainly south of the Bluegrass region.
Tuesday looks to at least start mild and dry ahead of the next
disturbance, which will dive SE out of Canada. POPs will ramp up
late in the day, and we could see falling afternoon temps given what
should be a decent temp/dewpoint spread. Went with a rain/snow mix
to start, but will carry all snow Tuesday night as the cold air
spills in. Best chance for snow will be in southern Indiana late
Tuesday night, and the Bluegrass region during the day on Wednesday.
Could see a quick half inch of snow in these areas, and temps will
struggle to crack 30 degrees. This remains a lower probability event
as the latest Euro keeps the best forcing for a deformation band
cleanly to our north.
Quick rebound in temps Thursday under strong shortwave ridging, and
then another shot of cold air arrives on Friday with a deep upper
trof diving into the Great Lakes. Continuing to lean on the colder
ECMWF temps, even as this run starts to look a bit more progressive.
The 12Z ECMWF is still closer to its predecessors than to the much
more progressive GFS. High confidence that we will be near or below
freezing for highs on Friday, but there is some doubt as to how long
the cold air will stick around in the Ohio Valley. In this pattern
it`s difficult to rule out a few flurries, especially in the north
and east. However, moisture appears to be limited, so will not carry
flurries just yet. Coldest night will be Friday night. At this point
the cold air mass does not appear to pack the same punch as the cold
outbreak earlier this week, but it still bears watching for
unseasonable cold.
&&
.AVIATION (00Z TAF Update)...
Updated at 625 PM EST Sat Jan 11 2014
The biggest TAF challenges will be timing of low clouds out of
SDF/LEX this evening and then possible low clouds late tonight at
SDF/LEX and light fog at BWG. Currently we sit in the base of an
upper level trough with MVFR cigs at SDF/LEX although as the trough
moves out this evening, the low clouds will exit the terminals by
1-3Z. Late tonight a final shortwave on the back side of the upper
trough will dive into the Midwest. Low clouds associated with this
wave were over Iowa and northern Illinois as of 2330Z. Judging by
the current trajectory for this wave using satellite imagery, it
seems low clouds will mainly fill in over central Indiana through
southern Ohio late tonight. However, a few models like the 18Z NAM
do bring some of those low clouds into the SDF/LEX terminals. Think
that LEX would stand the best chance at seeing a second period of
MVFR cigs tomorrow morning. Will leave SDF VFR for now but keep an
eye on the low clouds as they travel southeast toward our region
tonight. BWG could see some light MVFR fog toward sunrise as
ridging works into the region causing a stronger inversion and
lighter winds. However, with windy conditions today, don`t feel
like there should be much low level moisture left over to work with
for fog production. Will continue 5sm br at BWG from 10-13Z. After
13-15Z, conditions should return to VFR at all TAF sites. Winds
will back from W this evening to SW overnight and tomorrow to S by
tomorrow evening. Wind speeds will remain around or above 7kts for
a large portion of the SDF/LEX TAF period.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Update.........AMS
Short Term.....EER
Long Term......RAS
Aviation.......AMS
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
441 PM EST FRI JAN 10 2014
.SYNOPSIS...
HIGH PRESSURE MOVES OFFSHORE TODAY AND TONIGHT AS A SERIES OF WEAK
UPPER LEVEL TROUGHS TRACK ACROSS THE MID ATLANTIC REGION. A COLD
FRONT APPROACHES FROM THE WEST SATURDAY AND PUSHES THROUGH THE
REGION SATURDAY NIGHT EVENING. HIGH PRESSURE RETURNS FROM THE WEST
LATER SATURDAY NIGHT INTO SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
LATEST SURFACE ANALYSIS INDICATES A ~1034MB SFC HIGH PRESSURE NOW
WELL OFF THE NEW ENGLAND COASTLINE...WITH A SFC RIDGE AXIS
EXTENDING SW ALONG THE PIEDMONT INTO NE GA. TO THE SOUTHEAST, A
COASTAL TROUGH HAS NOW LIFTED INLAND ACROSS THE COASTAL
CAROLINAS...AND BRIEFLY LIFTED ACROSS FAR SE TIP OF THE
COMMONWEALTH EARLY THIS AFTN (TEMPS JUMPED INTO THE LOW 60S EARLY
THIS AFTN BEFORE DROPPING BACK INTO THE U40S OVER THE PAST FEW
HRS).
WARM/MOIST ADVECTION CONTINUES THIS AFTN...WITH SHRAS IN ASSN
WITH THE LATEST SLUG OF OVERRUNNING MOISTURE MOVING ACROSS THE
REGION ATTM. WV SAT IMAGERY SHOWING DISTURBANCE RESPONSIBLE FOR
THIS LATEST ROUND OF SHRAS LIFTING E-NE ACROSS THE LOWER MID-
ATLANTIC IN SSW FLOW ALOFT. OCCASIONAL LIGHT RAINFALL WILL
CONTINUE OVER THE NEXT FEW HOURS AS THIS WAVE MOVES THROUGH...WITH
SHRAS BECOMING LESS WIDESPREAD LATE TONIGHT AND ESPECIALLY AFTER
MIDNIGHT AS FRONT SHIFTS NORTH. FOR TEMPS, WE`VE FOLLOWED THE LEAD
OF THE HRRR AND HIGH RES NAM W/TEMP TRENDS THROUGH EARLY SAT
MORNING. EXPECT TEMPS WILL FALL VERY LITTLE EARLY TONIGHT ACROSS
CENTRAL AND NORTHERN ZONES...LIKELY RISING GRADUALLY TOWARD
MORNING AS THE WARM FRONT LIFTS NORTH ACROSS AREA. CONSIDERING THE
LIGHT WINDS, THIS WILL ALSO BRING WIDESPREAD STRATUS/AREAS OF FOG
INLAND EARLY TONIGHT THROUGH EARLY SATURDAY MORNING.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
WEEKEND GETS OFF TO A VERY WET START, WITH HIGH CONFIDENCE OF A
STEADY AND LOCALLY HEAVY RAINFALL ON SATURDAY. DEEP MOISTURE
THROUGH 300MB COMBINED WITH STRONG LIFT SHOULD PRODUCE MODERATE TO
OCCASIONALLY HEAVY RAIN BY AFTN. HOWEVER...QPF SHOULD LARGELY AVG
0.75-1.25" DUE TO THE QUICK MOTION OF THE SYSTEM. TEMPERATURES
SHOULD BE VERY MILD, AS THE SURFACE WARM FRONT SURGES N OF THE
LOCAL AREA EARLY IN THE DAY. BREEZY CONDITIONS DEVELOP FOR THE
EASTERN THIRD OF THE AREA...WITH A S WIND OF 15-20MPH IN THE WARM
SECTOR, WITH GUSTS TO AROUND 30MPH EXPECTED. FORECAST HIGHS WILL
RANGE FROM THE U50S/L60S IN THE MODIFIED WEDGE AIRMASS ACROSS THE
FAR NW TIER...WITH MID 60S TO AROUND 70 OVER THE I-95 CORRIDOR AND
THE LOWER EASTERN SHORE...AND LOW 70S ACROSS FAR EASTERN VA AND
INTERIOR NE NC. SEE CLIMATE SECTION BELOW...AS A FEW RECORD HIGHS
FOR THE DATE APPEAR ATTAINABLE. SREF CONTINUES TO ADVERTISE 90+%
CONFIDENCE IN 2M DEWPOINT VALUES AOA 60F ACROSS CENTRAL/EASTERN
SECTIONS. THIS COULD LEAD TO ISOLATED THUNDERSTORMS SAT AFTN,
PRIMARILY SOUTH AND EAST OF RIC /TRI- CITIES AREA TOWARDS HAMPTON
ROADS/TIDEWATER AREAS.
GOOD MODEL AGREEMENT IN DEPICTION OF STRONG LIFT (UPRIGHT
FRONTOGENESIS) FROM THE SURFACE TO ~850MB ON MODEL CROSS SECTIONS
PER THE GFS/NAM SAT AFTN. THIS IS PROGGED TO OCCUR IN A SYNOPTIC
ENVIRONMENT FEATURING A 65-70KT LLJ...50-60KT OF SW 0-6KM BULK
SHEAR...AND 500-700 J/KG MLCAPE. GIVEN THIS COMBINATION OF
SYNOPTIC AND MESOSCALE FACTORS...THERE IS A HIGH CONFIDENCE IN
WIDESPREAD MOD RAINFALL (FALLING HEAVILY AT TIMES). HOWEVER,
THERE IS ALSO POTENTIAL FOR A FORCED LINE OF LOW-TOPPED CONVECTION
(RARE BUT NOT UNPRECEDENTED FOR JANUARY) CAPABLE OF MIXING DOWN
SOME STRONG TO POTENTIALLY DAMAGING WIND GUSTS. AREA OF CONCERN
REMAINS MAINLY ACROSS THE AFOREMENTIONED AREAS OF S-CENTRAL/SE VA
AND NE NC. BASED ON THE LATEST 12Z/10 DATA...THE TIMING OF THE
GREATEST THREAT WOULD BE AFTER 18Z/1P SAT AFTERNOON INTO EARLY
EVENING. SE PORTIONS OF THE AREA REMAIN HIGHLIGHTED IN A DAY 2
SLIGHT RISK BY THE SPC...AND WILL CONTINUE TO HIGHLIGHT THIS AREA
IN THE HWO.
A TRANSITION DAY SUNDAY AND EARLY MONDAY AS UPPER TROUGH PIVOTS
OFFSHORE AND QUASI-ZONAL FLOW BRINGS A CLEARING SKY. WHILE NOT
NEARLY AS MILD AS SATURDAY, MAXIMA REMAIN ~1 S.D. ABOVE
NORMAL...CLIMBING INTO THE MID 50S TO NEAR 60 FOR MOST. EARLY
MORNING LOWS MONDAY IN THE 30S TO NEAR 40. FLOW ALOFT BECOMES
INCREASINGLY SW ON MONDAY...WITH GRADUALLY INCREASING HIGH CLOUDS
LATER IN THE DAY AS AN UPPER LEVEL TROUGH BARRELS EASTWARD FROM THE
PLAINS MONDAY THROUGH MONDAY NIGHT. ECMWF IS A BIT MORE AGGRESSIVE
WITH THIS FEATURE THAN THE GFS. FOR NOW, HAVE PLAYED TOWARDS THE
DRIER/WEAKER GFS SOLUTION...WITH WARM SW FLOW ALLOWING MAXIMA TO
WARM BACK INTO THE U50S TO L60S.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MEDIUM RANGE MODELS IN GENERAL AGREEMENT WITH AMPLIFIED...BUT
PROGRESSIVE UPPER LEVEL PATTERN THROUGH THE EXTENDED PERIOD.
HOWEVER...MODELS CONTINUE TO STRUGGLE WITH MID-LEVEL FEATURES
DOWNSTREAM OF A LONGWAVE TROUGH OVER THE ERN CONUS. LONGWAVE
TROUGH WILL PROGRESS EWD OVER THE CENTRAL CONUS MON NIGHT-TUES AS
SHORTWAVE ENERGY ROUNDS THE BASE OF THE TROUGH AND EJECTS NEWD
FROM THE DEEP SOUTH. SHORTWAVE ENERGY WILL EJECT FROM THE DEEP
SOUTH TUES MORNING OVER THE MID- ATLANTIC TUES AFTERNOON. ECMWF IS
MUCH STRONGER WITH THE SHORTWAVE ENERGY AND SWLY FLOW WHICH WOULD
ADVECT DEEPER MOISTURE INTO THE REGION IN ADVANCE OF A COLD FRONT.
MEANWHILE...GFS IS MUCH WEAKER WITH THE ENERGY AND HAS LIMITED
MOISTURE. SFC PATTERNS ALSO QUITE DIFFERENT AS SFC LOW PRESSURE
CROSSES THE OH VALLEY. HAVE TRENDED CURRENT FORECAST TOWARD THE
ECMWF...BUT MAINTAINED SOME GFS GUIDANCE TO ACCOUNT FOR
UNCERTAINTIES. THE RESULT IS CHANCE POPS ACROSS THE REGION
BEGINNING TUES MORNING INTO TUES AFTERNOON AS THE SYSTEM LIFTS
OVER THE REGION. COLD FRONT/MOISTURE WILL PUSH OFFSHORE LATE TUES
BRINGING AN END TO THE PRECIP. BASE OF THE TROUGH WILL EXTEND INTO
THE DEEP SOUTH TUES NIGHT-WEDS MORNING AS AN ASSOCIATED STRONGER
COLD FRONT MOVES INTO THE REGION. UPPER DYNAMICS WILL DEVELOP A
WAVE ALONG THE FRONT...LEADING TO CYCLOGENESIS OVER THE LOCAL AREA
TO JUST OFFSHORE EARLY WEDS. MOISTURE WILL BE RATHER
LIMITED/SHALLOW...BUT BASED ON DYNAMICS...SLIGHT CHANCE POPS ARE
WARRANTED ATTM.
TROUGH AXIS WILL PUSH OFFSHORE WED NIGHT-THURS MORNING AS SFC HIGH
PRESSURE BUILDS EWD OVER THE DEEP SOUTH...RIDGING NWD INTO THE LOCAL
AREA. NRN STREAM WILL REMAIN ACTIVE AS ANOTHER SHORTWAVE DIGS OVER
THE GREAT LAKES REGION LATE THURS-FRI...PUSHING A COLD FRONT ACROSS
THE OH VALLEY INTO THE MID-ATLANTIC REGION FRI. UNCERTAINTY IS
QUITE HIGH THIS FAR OUT...SO HAVE LEFT THE END OF THE WORK WEEK DRY.
HIGH TEMPS WILL WARM ABOVE NORMAL TUES (UPPER 50S-LOW 60S) BEFORE
FALLING BACK TO SEASONABLE NORMS THRU THE EXTENDED. MILD MON NIGHT
(LOW-MID 40S) BEFORE RETURNING TO NEAR OR SLIGHTLY ABOVE SEASONABLE
LOWS (LOW-MID 30S) THRU THE EXTENDED.
&&
.AVIATION /22Z FRIDAY THROUGH WEDNESDAY/...
-RA AND BR ACROSS THE AREA WILL CONTINUE THROUGH TONIGHT. SITES
NORTH AND WEST OF A WARM FRONT(KRIC AND KSBY) ARE EXPERIENCING
IFR CONDITIONS AND WILL CONTINUE TO DO SO UNTIL THE WARM FRONT
LIFTS THROUGH THOSE AREAS. EXPECT WINDS TO GUST OVER 20KT SAT
AS PRESSURE GRADIENT TIGHTENS BETWEEN APPROACHING TROUGH FROM THE
WEST AND HIGH PRESSURE OFFSHORE. SCATTERED SHOWERS ARE POSSIBLE
DURING THE LATE MORNING/EARLY AFTN HOURS SAT AS A COLD FRONT
PUSHES EAST.
OUTLOOK...A MORE ORGANIZED FRONTAL SYSTEM APPROACHES THE REGION ON
SATURDAY...WITH PERIODS OF RAIN AND WIDESPREAD MVFR/OCNL IFR
CONDITIONS AND GUSTY WINDS SAT AFTN. LOOK FOR DRY AND VFR CONDITIONS
SUNDAY AND MONDAY THEN DETERIORATING CONDS ONCE AGAIN AROUND
TUESDAY.
&&
.MARINE...
HIGH PRESSURE HAS LOCATED OVER THE WRN ATLANTIC THIS AFTERNOON.
FLOW WILL TURN TO THE SOUTH AND INCREASE BEHIND A LIFTING WARM
FRONT TONIGHT. GRADIENT WILL STRENGTHENS AS LOW PRESSURE AND AN
ASSOCIATED COLD FRONT APPROACH FROM THE WEST. LOW-LEVEL WINDS
(925MB) WILL INCREASE TO ~50 KT TONIGHT-SAT MORNING...BUT WAA/WEAK
LAPSE RATES AND COLD WATERS WILL LIMIT THE HIGHER VELOCITY WINDS
FROM REACHING THE WATER. HOWEVER...MODELS IN GOOD AGREEMENT FOR
SOLID SCA CONDITIONS TONIGHT-SAT. SEAS WILL BUILD TO 5 TO 9 FT (UP
TO 10+ FT 20 NM OUT IN THE NRN COASTAL WATERS). COLD FRONT WILL
CROSS THE WATERS LATE SAT-EARLY SAT NIGHT AS WINDS BACK TO THE
WEST AND REMAIN 15-20 KT OVER THE BAY/RIVERS AND 20-25 KT OVER THE
COASTAL WATERS. A LINE OF CONVECTION IS EXPECTED ALONG THE COLD
FRONT LATE SAT...WHICH MAY BRIEFLY PRODUCE GALE FORCE WINDS.
HOWEVER...WILL LIKELY HANDLE THESE BRIEF/STRONG WINDS WITH SPECIAL
MARINE WARNINGS INSTEAD OF GALE WORDING. HIGH PRESSURE WILL BUILD
EWD OVER THE DEEP SOUTH SAT NIGHT-SUN...EXTENDING NWD OVER THE
LOCAL AREA LATE SUN MORNING. THIS WILL ALLOW THE GRADIENT TO RELAX
AND SPEEDS TO DIMINISH. AS HIGH PRESSURE PUSHES OFF THE SE COAST
SUN NIGHT...FLOW WILL RETURN TO THE SOUTH. UNSETTLED CONDITIONS
WILL RETURN TO THE WATERS TUES-WEDS.
&&
.CLIMATE...
RECORD HIGH TEMPERATURES SATURDAY JANUARY 11
RIC 72/1975
ORF 75/1974
SBY 68/1975
ECG 75/1974
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 7 AM SATURDAY TO 6 AM EST SUNDAY FOR
ANZ635>637.
SMALL CRAFT ADVISORY FROM 4 AM SATURDAY TO 10 AM EST SUNDAY
FOR ANZ632>634.
SMALL CRAFT ADVISORY FROM 4 AM SATURDAY TO 6 AM EST SUNDAY FOR
ANZ630-631.
SMALL CRAFT ADVISORY FROM 7 AM SATURDAY TO 10 AM EST SUNDAY
FOR ANZ638.
SMALL CRAFT ADVISORY FROM 4 AM SATURDAY TO 4 PM EST SUNDAY FOR
ANZ650-652-654-656-658.
&&
$$
SYNOPSIS...MAM
NEAR TERM...MAM
SHORT TERM...AJZ/MAM
LONG TERM...SAM
AVIATION...JDM/DAP
MARINE...SAM
CLIMATE...
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
430 PM EST FRI JAN 10 2014
.SYNOPSIS...
HIGH PRESSURE MOVES OFFSHORE TODAY AND TONIGHT AS A SERIES OF WEAK
UPPER LEVEL TROUGHS TRACK ACROSS THE MID ATLANTIC REGION. A COLD
FRONT APPROACHES FROM THE WEST SATURDAY AND PUSHES THROUGH THE
REGION SATURDAY NIGHT EVENING. HIGH PRESSURE RETURNS FROM THE WEST
LATER SATURDAY NIGHT INTO SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
LATEST SURFACE ANALYSIS INDICATES A ~1034MB SFC HIGH PRESSURE NOW
WELL OFF THE NEW ENGLAND COASTLINE...WITH A SFC RIDGE AXIS
EXTENDING SW ALONG THE PIEDMONT INTO NE GA. TO THE SOUTHEAST, A
COASTAL TROUGH HAS NOW LIFTED INLAND ACROSS THE COASTAL
CAROLINAS...AND BRIEFLY LIFTED ACROSS FAR SE TIP OF THE
COMMONWEALTH EARLY THIS AFTN (TEMPS JUMPED INTO THE LOW 60S EARLY
THIS AFTN BEFORE DROPPING BACK INTO THE U40S OVER THE PAST FEW
HRS).
WARM/MOIST ADVECTION CONTINUES THIS AFTN...WITH SHRAS IN ASSN
WITH THE LATEST SLUG OF OVERRUNNING MOISTURE MOVING ACROSS THE
REGION ATTM. WV SAT IMAGERY SHOWING DISTURBANCE RESPONSIBLE FOR
THIS LATEST ROUND OF SHRAS LIFTING E-NE ACROSS THE LOWER MID-
ATLANTIC IN SSW FLOW ALOFT. OCCASIONAL LIGHT RAINFALL WILL
CONTINUE OVER THE NEXT FEW HOURS AS THIS WAVE MOVES THROUGH...WITH
SHRAS BECOMING LESS WIDESPREAD LATE TONIGHT AND ESPECIALLY AFTER
MIDNIGHT AS FRONT SHIFTS NORTH. FOR TEMPS, WE`VE FOLLOWED THE LEAD
OF THE HRRR AND HIGH RES NAM W/TEMP TRENDS THROUGH EARLY SAT
MORNING. EXPECT TEMPS WILL FALL VERY LITTLE EARLY TONIGHT ACROSS
CENTRAL AND NORTHERN ZONES...LIKELY RISING GRADUALLY TOWARD
MORNING AS THE WARM FRONT LIFTS NORTH ACROSS AREA. CONSIDERING THE
LIGHT WINDS, THIS WILL ALSO BRING WIDESPREAD STRATUS/AREAS OF FOG
INLAND EARLY TONIGHT THROUGH EARLY SATURDAY MORNING.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY/...
WEEKEND GETS OFF TO A VERY WET START, WITH HIGH CONFIDENCE OF A
STEADY AND LOCALLY HEAVY RAINFALL ON SATURDAY. DEEP MOISTURE
THROUGH 300MB COMBINED WITH STRONG LIFT SHOULD PRODUCE MODERATE
TO OCCASIONALLY HEAVY RAIN BY AFTN. HOWEVER...QPF SHOULD LARGELY
AVG 0.75-1.25" DUE TO THE QUICK MOTION OF THE SYSTEM. TEMPERATURES
SHOULD BE VERY MILD, AS THE SURFACE WARM FRONT SURGES N OF THE
LOCAL AREA EARLY IN THE DAY. BREEZY CONDITIONS DEVELOP FOR THE
EASTERN THIRD OF THE AREA...WITH A S WIND OF 15-20MPH IN THE WARM
SECTOR, WITH GUSTS TO AROUND 30MPH EXPECTED. FORECAST HIGHS WILL
RANGE FROM THE U50S/L60S IN THE MODIFIED WEDGE AIRMASS ACROSS THE
FAR NW TIER...WITH MID 60S TO AROUND 70 OVER THE I-95 CORRIDOR AND
THE LOWER EASTERN SHORE...AND LOW 70S ACROSS FAR EASTERN VA AND
INTERIOR NE NC. SEE CLIMATE SECTION BELOW...AS A FEW RECORD HIGHS
FOR THE DATE APPEAR ATTAINABLE. SREF CONTINUES TO ADVERTISE 90+%
CONFIDENCE IN 2M DEWPOINT VALUES AOA 60F ACROSS CENTRAL/EASTERN
SECTIONS. THIS COULD LEAD TO ISOLATED THUNDERSTORMS SAT AFTN,
PRIMARILY SOUTH AND EAST OF RIC /TRI- CITIES AREA TOWARDS HAMPTON
ROADS/TIDEWATER AREAS.
GOOD MODEL AGREEMENT IN DEPICTION OF STRONG LIFT (UPRIGHT
FRONTOGENESIS) FROM THE SURFACE TO ~850MB ON MODEL CROSS SECTIONS
PER THE GFS/NAM SAT AFTN. THIS IS PROGGED TO OCCUR IN A SYNOPTIC
ENVIRONMENT FEATURING A 65-70KT LLJ...50-60KT OF SW 0-6KM BULK
SHEAR...AND 500-700 J/KG MLCAPE. GIVEN THIS COMBINATION OF
SYNOPTIC AND MESOSCALE FACTORS...THERE IS A HIGH CONFIDENCE IN
WIDESPREAD MOD RAINFALL (FALLING HEAVILY AT TIMES). HOWEVER,
THERE IS ALSO POTENTIAL FOR A FORCED LINE OF LOW-TOPPED CONVECTION
(RARE BUT NOT UNPRECEDENTED FOR JANUARY) CAPABLE OF MIXING DOWN
SOME STRONG TO POTENTIALLY DAMAGING WIND GUSTS. AREA OF CONCERN
REMAINS MAINLY ACROSS THE AFOREMENTIONED AREAS OF S-CENTRAL/SE VA
AND NE NC. BASED ON THE LATEST 12Z/10 DATA...THE TIMING OF THE
GREATEST THREAT WOULD BE AFTER 18Z/1P SAT AFTERNOON INTO EARLY
EVENING. SE PORTIONS OF THE AREA REMAIN HIGHLIGHTED IN A DAY 2
SLIGHT RISK BY THE SPC...AND WILL CONTINUE TO HIGHLIGHT THIS AREA
IN THE HWO.
A TRANSITION DAY SUNDAY AND EARLY MONDAY AS UPPER TROUGH PIVOTS
OFFSHORE AND QUASI-ZONAL FLOW BRINGS A CLEARING SKY. WHILE NOT
NEARLY AS MILD AS SATURDAY, MAXIMA REMAIN ~1 S.D. ABOVE
NORMAL...CLIMBING INTO THE MID 50S TO NEAR 60 FOR MOST. EARLY
MORNING LOWS MONDAY IN THE 30S TO NEAR 40. FLOW ALOFT BECOMES
INCREASINGLY SW ON MONDAY...WITH GRADUALLY INCREASING HIGH CLOUDS
LATER IN THE DAY AS AN UPPER LEVEL TROUGH BARRELS EASTWARD FROM THE
PLAINS MONDAY THROUGH MONDAY NIGHT. ECMWF IS A BIT MORE AGGRESSIVE
WITH THIS FEATURE THAN THE GFS. FOR NOW, HAVE PLAYED TOWARDS THE
DRIER/WEAKER GFS SOLUTION...WITH WARM SW FLOW ALLOWING MAXIMA TO
WARM BACK INTO THE U50S TO L60S.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
MEDIUM RANGE MODELS IN GENERAL AGREEMENT WITH AMPLIFIED...BUT
PROGRESSIVE UPPER LEVEL PATTERN THROUGH THE EXTENDED PERIOD.
HOWEVER...MODELS CONTINUE TO STRUGGLE WITH MID-LEVEL FEATURES
DOWNSTREAM OF A LONGWAVE TROUGH OVER THE ERN CONUS. LONGWAVE TROUGH
WILL PROGRESS EWD OVER THE CENTRAL CONUS MON NIGHT-TUES AS SHORTWAVE
ENERGY ROUNDS THE BASE OF THE TROUGH AND EJECTS NEWD FROM THE DEEP
SOUTH. SHORTWAVE ENERGY WILL EJECT FROM THE DEEP SOUTH TUES MORNING
OVER THE MID-ATLANTIC TUES AFTERNOON. ECMWF IS MUCH STRONGER WITH
THE SHORTWAVE ENERGY AND SWLY FLOW WHICH WOULD ADVECT DEEPER
MOISTURE INTO THE REGION IN ADVANCE OF A COLD FRONT. MEANWHILE...GFS
IS MUCH WEAKER WITH THE ENERGY AND HAS LIMITED MOISTURE. SFC
PATTERNS ALSO QUITE DIFFERENT AS SFC LOW PRESSURE CROSSES THE OH
VALLEY. HAVE TRENDED CURRENT FORECAST TOWARD THE ECMWF...BUT
MAINTAINED SOME GFS GUIDANCE TO ACCOUNT FOR UNCERTAINTIES. THE
RESULT IS CHANCE POPS ACROSS THE REGION BEGINNING TUES MORNING INTO
TUES AFTERNOON AS THE SYSTEM LIFTS OVER THE REGION. COLD
FRONT/MOISTURE WILL PUSH OFFSHORE LATE TUES BRINGING AN END TO THE
PRECIP. BASE OF THE TROUGH WILL EXTEND INTO THE DEEP SOUTH TUES
NIGHT-WEDS MORNING AS AN ASSOCIATED STRONGER COLD FRONT MOVES INTO
THE REGION. UPPER DYNAMICS WILL DEVELOP A WAVE ALONG THE
FRONT...LEADING TO CYCLOGENESIS OVER THE LOCAL AREA TO JUST OFFSHORE
EARLY WEDS. MOISTURE WILL BE RATHER LIMITED/SHALLOW...BUT BASED ON
DYNAMICS...SLIGHT CHANCE POPS ARE WARRANTED ATTM.
TROUGH AXIS WILL PUSH OFFSHORE WED NIGHT-THURS MORNING AS SFC HIGH
PRESSURE BUILDS EWD OVER THE DEEP SOUTH...RIDGING NWD INTO THE LOCAL
AREA. NRN STREAM WILL REMAIN ACTIVE AS ANOTHER SHORTWAVE DIGS OVER
THE GREAT LAKES REGION LATE THURS-FRI...PUSHING A COLD FRONT ACROSS
THE OH VALLEY INTO THE MID-ATLANTIC REGION FRI. UNCERTAINTY IS
QUITE HIGH THIS FAR OUT...SO HAVE LEFT THE END OF THE WORK WEEK DRY.
HIGH TEMPS WILL WARM ABOVE NORMAL TUES (UPPER 50S-LOW 60S) BEFORE
FALLING BACK TO SEASONABLE NORMS THRU THE EXTENDED. MILD MON NIGHT
(LOW-MID 40S) BEFORE RETURNING TO NEAR OR SLIGHTLY ABOVE SEASONABLE
LOWS (LOW-MID 30S) THRU THE EXTENDED.
&&
.AVIATION /22Z FRIDAY THROUGH WEDNESDAY/...
-RA AND BR ACROSS THE AREA WILL CONTINUE THROUGH TONIGHT. SITES
NORTH AND WEST OF A WARM FRONT(KRIC AND KSBY) ARE EXPERIENCING
IFR CONDITIONS AND WILL CONTINUE TO DO SO UNTIL THE WARM FRONT
LIFTS THROUGH THOSE AREAS. EXPECT WINDS TO GUST OVER 20KT SAT
AS PRESSURE GRADIENT TIGHTENS BETWEEN APPROACHING TROUGH FROM THE
WEST AND HIGH PRESSURE OFFSHORE. SCATTERED SHOWERS ARE POSSIBLE
DURING THE LATE MORNING/EARLY AFTN HOURS SAT AS A COLD FRONT
PUSHES EAST.
OUTLOOK...A MORE ORGANIZED FRONTAL SYSTEM APPROACHES THE REGION ON
SATURDAY...WITH PERIODS OF RAIN AND WIDESPREAD MVFR/OCNL IFR
CONDITIONS AND GUSTY WINDS SAT AFTN. LOOK FOR DRY AND VFR CONDITIONS
SUNDAY AND MONDAY THEN DETERIORATING CONDS ONCE AGAIN AROUND
TUESDAY.
&&
.MARINE...
HIGH PRESSURE MOVES OFF THE NEW ENGLAND COAST TODAY...AS A TROF OF LOW
PRESSURE DEVELOPS ALONG THE CAROLINA COAST. E WINDS 10 KT OR LESS
THIS MORNING WILL BECOME SE 10-15 KT BY EVENING. SE WINDS WILL THEN
INCREASE TO 15 TO 20 KT LATE TONIGHT BEFORE BECOME S AND INCREASING
TO 15 TO 25 KT AND GUSTY FOR SAT...AS A WARM FRONT LIFTS NWRD THRU
THE AREA...FOLLOWED BY THE APPROACH OF A COLD FRONT. HAVE ISSUED
SCA`S BEGINNING EARLY SAT MORNING FOR ALL WATERS BASED ON GOOD
AGREEMENT IN MODELS FOR GUSTY WINDS DURING SAT INTO SAT NIGHT...
ALONG WITH SEAS BUILDING TO 5-9 FT. GALE FORCE WINDS ARE NOT
EXPECTED ATTM EXCEPT POSSIBLY IN A NARROW BAND OF CONVECTION THAT
MAY MOVE THRU WITH THE COLD FRONT LATE SAT. THIS CAN LIKELY BE
HANDLED WITH SPECIAL MARINE WARNINGS AS OPPOSED TO A SHORT DURATION
GALE WARNING. S-SW WINDS SAT INTO SAT EVE WILL VEER TO THE WNW AND
REMAIN GUSTY BEHIND THE FRONT SAT NIGHT INTO SUN MORNING...THEN
SETTLE DOWN AND BECOME SW LATE SUNDAY AS HIGH PRESSURE BUILDS IN.
ANOTHER ROUND OF UNSETTLED CONDITIONS IS POSSIBLE BY TUESDAY.
&&
.CLIMATE...
RECORD HIGH TEMPERATURES SATURDAY JANUARY 11
RIC 72/1975
ORF 75/1974
SBY 68/1975
ECG 75/1974
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 7 AM SATURDAY TO 6 AM EST SUNDAY FOR
ANZ635>637.
SMALL CRAFT ADVISORY FROM 4 AM SATURDAY TO 10 AM EST SUNDAY
FOR ANZ632>634.
SMALL CRAFT ADVISORY FROM 4 AM SATURDAY TO 6 AM EST SUNDAY FOR
ANZ630-631.
SMALL CRAFT ADVISORY FROM 7 AM SATURDAY TO 10 AM EST SUNDAY
FOR ANZ638.
SMALL CRAFT ADVISORY FROM 4 AM SATURDAY TO 4 PM EST SUNDAY FOR
ANZ650-652-654-656-658.
&&
$$
SYNOPSIS...MAM
NEAR TERM...MAM
SHORT TERM...AJZ/MAM
LONG TERM...SAM
AVIATION...JDM/DAP
MARINE...JDM
CLIMATE...
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
411 PM EST FRI JAN 10 2014
.SYNOPSIS...
HIGH PRESSURE MOVES OFFSHORE TODAY AND TONIGHT AS A SERIES OF WEAK
UPPER LEVEL TROUGHS TRACK ACROSS THE MID ATLANTIC REGION. A COLD
FRONT APPROACHES FROM THE WEST SATURDAY AND PUSHES THROUGH THE
REGION SATURDAY NIGHT EVENING. HIGH PRESSURE RETURNS FROM THE WEST
LATER SATURDAY NIGHT INTO SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
LATEST SURFACE ANALYSIS INDICATES A ~1034MB SFC HIGH PRESSURE NOW
WELL OFF THE NEW ENGLAND COASTLINE...WITH A SFC RIDGE AXIS
EXTENDING SW ALONG THE PIEDMONT INTO NE GA. TO THE SOUTHEAST, A
COASTAL TROUGH HAS NOW LIFTED INLAND ACROSS THE COASTAL
CAROLINAS...AND BRIEFLY LIFTED ACROSS FAR SE TIP OF THE
COMMONWEALTH EARLY THIS AFTN (TEMPS JUMPED INTO THE LOW 60S EARLY
THIS AFTN BEFORE DROPPING BACK INTO THE U40S OVER THE PAST FEW
HRS).
WARM/MOIST ADVECTION CONTINUES THIS AFTN...WITH SHRAS IN ASSN
WITH THE LATEST SLUG OF OVERRUNNING MOISTURE MOVING ACROSS THE
REGION ATTM. WV SAT IMAGERY SHOWING DISTURBANCE RESPONSIBLE FOR
THIS LATEST ROUND OF SHRAS LIFTING E-NE ACROSS THE LOWER MID-
ATLANTIC IN SSW FLOW ALOFT. OCCASIONAL LIGHT RAINFALL WILL
CONTINUE OVER THE NEXT FEW HOURS AS THIS WAVE MOVES THROUGH...WITH
SHRAS BECOMING LESS WIDESPREAD LATE TONIGHT AND ESPECIALLY AFTER
MIDNIGHT AS FRONT SHIFTS NORTH. FOR TEMPS, WE`VE FOLLOWED THE LEAD
OF THE HRRR AND HIGH RES NAM W/TEMP TRENDS THROUGH EARLY SAT
MORNING. EXPECT TEMPS WILL FALL VERY LITTLE EARLY TONIGHT ACROSS
CENTRAL AND NORTHERN ZONES...LIKELY RISING GRADUALLY TOWARD
MORNING AS THE WARM FRONT LIFTS NORTH ACROSS AREA. CONSIDERING THE
LIGHT WINDS, THIS WILL ALSO BRING WIDESPREAD STRATUS/AREAS OF FOG
INLAND EARLY TONIGHT THROUGH EARLY SATURDAY MORNING.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY/...
WEEKEND GETS OFF TO A VERY WET START, WITH HIGH CONFIDENCE OF A
STEADY AND LOCALLY HEAVY RAINFALL ON SATURDAY. DEEP MOISTURE
THROUGH 300MB COMBINED WITH STRONG LIFT SHOULD PRODUCE MODERATE
TO OCCASIONALLY HEAVY RAIN BY AFTN. HOWEVER...QPF SHOULD LARGELY
AVG 0.75-1.00IN DUE TO THE QUICK MOTION OF THE SYSTEM.
TEMPERATURES SHOULD BE VERY MILD, AS THE SURFACE WARM FRONT SURGES
N OF THE LOCAL AREA EARLY IN THE DAY. BREEZY CONDITIONS DEVELOP
FOR THE EASTERN THIRD OF THE AREA...WITH A S WIND OF 15-20MPH IN
THE WARM SECTOR, WITH GUSTS TO AROUND 30MPH EXPECTED. FORECAST
HIGHS WILL RANGE FROM THE U50S/L60S IN THE MODIFIED WEDGE AIRMASS
ACROSS THE FAR NW TIER...WITH MID 60S TO AROUND 70 OVER THE I-95
CORRIDOR AND THE LOWER EASTERN SHORE...AND LOW 70S ACROSS FAR
EASTERN VA AND INTERIOR NE NC. SEE CLIMATE SECTION BELOW...AS A
FEW RECORD HIGHS FOR THE DATE APPEAR ATTAINABLE. SREF CONTINUES
TO ADVERTISE 90+% CONFIDENCE IN 2M DEWPOINT VALUES AOA 60F ACROSS
CENTRAL/EASTERN SECTIONS. THIS COULD LEAD TO ISOLATED
THUNDERSTORMS SAT AFTN, PRIMARILY SOUTH AND EAST OF RIC /TRI-
CITIES AREA TOWARDS HAMPTON ROADS/TIDEWATER AREAS.
GOOD MODEL AGREEMENT IN DEPICTION OF STRONG LIFT (UPRIGHT
FRONTOGENESIS) FROM THE SURFACE TO ~850MB ON MODEL CROSS SECTIONS
PER THE GFS/NAM SAT AFTN. THIS IS PROGGED TO OCCUR IN A SYNOPTIC
ENVIRONMENT FEATURING A 65-70KT LLJ...50-60KT OF SW 0-6KM BULK
SHEAR...AND 500-700 J/KG MLCAPE. GIVEN THIS COMBINATION OF
SYNOPTIC AND MESOSCALE FACTORS...THERE IS A HIGH CONFIDENCE IN
WIDESPREAD MOD RAINFALL (FALLING HEAVILY AT TIMES). HOWEVER,
THERE IS ALSO POTENTIAL FOR A FORCED LINE OF LOW-TOPPED CONVECTION
(RARE BUT NOT UNPRECEDENTED FOR JANUARY) CAPABLE OF MIXING DOWN
SOME STRONG TO POTENTIALLY DAMAGING WIND GUSTS. AREA OF CONCERN
REMAINS MAINLY ACROSS THE AFOREMENTIONED AREAS OF S-CENTRAL/SE VA
AND NE NC. BASED ON THE LATEST 12Z/10 DATA...THE TIMING OF THE
GREATEST THREAT WOULD BE AFTER 18Z/1P SAT AFTERNOON INTO EARLY
EVENING. SE PORTIONS OF THE AREA REMAIN HIGHLIGHTED IN A DAY 2
SLIGHT RISK BY THE SPC...AND WILL CONTINUE TO HIGHLIGHT THIS AREA
IN THE HWO.
A TRANSITION DAY SUNDAY AND EARLY MONDAY AS UPPER TROUGH PIVOTS
OFFSHORE AND QUASI-ZONAL FLOW BRINGS A CLEARING SKY. WHILE NOT
NEARLY AS MILD AS SATURDAY, MAXIMA REMAIN ~1 S.D. ABOVE
NORMAL...CLIMBING INTO THE MID 50S TO NEAR 60 FOR MOST. EARLY
MORNING LOWS MONDAY IN THE 30S TO NEAR 40. FLOW ALOFT BECOMES
INCREASINGLY SW ON MONDAY...WITH GRADUALLY INCREASING HIGH CLOUDS
LATER IN THE DAY AS AN UPPER LEVEL TROUGH BARRELS EASTWARD FROM THE
PLAINS MONDAY THROUGH MONDAY NIGHT. ECMWF IS A BIT MORE AGGRESSIVE
WITH THIS FEATURE THAN THE GFS. FOR NOW, HAVE PLAYED TOWARDS THE
DRIER/WEAKER GFS SOLUTION...WITH WARM SW FLOW ALLOWING MAXIMA TO
WARM BACK INTO THE U50S TO L60S.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
MEDIUM RANGE MODELS IN GENERAL AGREEMENT WITH AMPLIFIED...BUT
PROGRESSIVE UPPER LEVEL PATTERN THROUGH THE EXTENDED PERIOD.
HOWEVER...MODELS CONTINUE TO STRUGGLE WITH MID-LEVEL FEATURES
DOWNSTREAM OF A LONGWAVE TROUGH OVER THE ERN CONUS. LONGWAVE TROUGH
WILL PROGRESS EWD OVER THE CENTRAL CONUS MON NIGHT-TUES AS SHORTWAVE
ENERGY ROUNDS THE BASE OF THE TROUGH AND EJECTS NEWD FROM THE DEEP
SOUTH. SHORTWAVE ENERGY WILL EJECT FROM THE DEEP SOUTH TUES MORNING
OVER THE MID-ATLANTIC TUES AFTERNOON. ECMWF IS MUCH STRONGER WITH
THE SHORTWAVE ENERGY AND SWLY FLOW WHICH WOULD ADVECT DEEPER
MOISTURE INTO THE REGION IN ADVANCE OF A COLD FRONT. MEANWHILE...GFS
IS MUCH WEAKER WITH THE ENERGY AND HAS LIMITED MOISTURE. SFC
PATTERNS ALSO QUITE DIFFERENT AS SFC LOW PRESSURE CROSSES THE OH
VALLEY. HAVE TRENDED CURRENT FORECAST TOWARD THE ECMWF...BUT
MAINTAINED SOME GFS GUIDANCE TO ACCOUNT FOR UNCERTAINTIES. THE
RESULT IS CHANCE POPS ACROSS THE REGION BEGINNING TUES MORNING INTO
TUES AFTERNOON AS THE SYSTEM LIFTS OVER THE REGION. COLD
FRONT/MOISTURE WILL PUSH OFFSHORE LATE TUES BRINGING AN END TO THE
PRECIP. BASE OF THE TROUGH WILL EXTEND INTO THE DEEP SOUTH TUES
NIGHT-WEDS MORNING AS AN ASSOCIATED STRONGER COLD FRONT MOVES INTO
THE REGION. UPPER DYNAMICS WILL DEVELOP A WAVE ALONG THE
FRONT...LEADING TO CYCLOGENESIS OVER THE LOCAL AREA TO JUST OFFSHORE
EARLY WEDS. MOISTURE WILL BE RATHER LIMITED/SHALLOW...BUT BASED ON
DYNAMICS...SLIGHT CHANCE POPS ARE WARRANTED ATTM.
TROUGH AXIS WILL PUSH OFFSHORE WED NIGHT-THURS MORNING AS SFC HIGH
PRESSURE BUILDS EWD OVER THE DEEP SOUTH...RIDGING NWD INTO THE LOCAL
AREA. NRN STREAM WILL REMAIN ACTIVE AS ANOTHER SHORTWAVE DIGS OVER
THE GREAT LAKES REGION LATE THURS-FRI...PUSHING A COLD FRONT ACROSS
THE OH VALLEY INTO THE MID-ATLANTIC REGION FRI. UNCERTAINTY IS
QUITE HIGH THIS FAR OUT...SO HAVE LEFT THE END OF THE WORK WEEK DRY.
HIGH TEMPS WILL WARM ABOVE NORMAL TUES (UPPER 50S-LOW 60S) BEFORE
FALLING BACK TO SEASONABLE NORMS THRU THE EXTENDED. MILD MON NIGHT
(LOW-MID 40S) BEFORE RETURNING TO NEAR OR SLIGHTLY ABOVE SEASONABLE
LOWS (LOW-MID 30S) THRU THE EXTENDED.
&&
.AVIATION /21Z FRIDAY THROUGH WEDNESDAY/...
-RA AND BR ACROSS THE AREA WILL CONTINUE THROUGH TONIGHT. SITES
NORTH AND WEST OF A WARM FRONT(KRIC AND KSBY) ARE EXPERIENCING
IFR CONDITIONS AND WILL CONTINUE TO DO SO UNTIL THE WARM FRONT
LIFTS THROUGH THOSE AREAS. EXPECT WINDS TO GUST OVER 20KT SAT
AS PRESSURE GRADIENT TIGHTENS BETWEEN APPROACHING TROUGH FROM THE
WEST AND HIGH PRESSURE OFFSHORE. SCATTERED SHOWERS ARE POSSIBLE
DURING THE LATE MORNING/EARLY AFTN HOURS SAT AS A COLD FRONT
PUSHES EAST.
OUTLOOK...A MORE ORGANIZED FRONTAL SYSTEM APPROACHES THE REGION ON
SATURDAY...WITH PERIODS OF RAIN AND WIDESPREAD MVFR/OCNL IFR
CONDITIONS AND GUSTY WINDS SAT AFTN. LOOK FOR DRY AND VFR CONDITIONS
SUNDAY AND MONDAY THEN DETERIORATING CONDS ONCE AGAIN AROUND
TUESDAY.
&&
.MARINE...
HIGH PRESSURE MOVES OFF THE NEW ENGLAND COAST TODAY...AS A TROF OF LOW
PRESSURE DEVELOPS ALONG THE CAROLINA COAST. E WINDS 10 KT OR LESS
THIS MORNING WILL BECOME SE 10-15 KT BY EVENING. SE WINDS WILL THEN
INCREASE TO 15 TO 20 KT LATE TONIGHT BEFORE BECOME S AND INCREASING
TO 15 TO 25 KT AND GUSTY FOR SAT...AS A WARM FRONT LIFTS NWRD THRU
THE AREA...FOLLOWED BY THE APPROACH OF A COLD FRONT. HAVE ISSUED
SCA`S BEGINNING EARLY SAT MORNING FOR ALL WATERS BASED ON GOOD
AGREEMENT IN MODELS FOR GUSTY WINDS DURING SAT INTO SAT NIGHT...
ALONG WITH SEAS BUILDING TO 5-9 FT. GALE FORCE WINDS ARE NOT
EXPECTED ATTM EXCEPT POSSIBLY IN A NARROW BAND OF CONVECTION THAT
MAY MOVE THRU WITH THE COLD FRONT LATE SAT. THIS CAN LIKELY BE
HANDLED WITH SPECIAL MARINE WARNINGS AS OPPOSED TO A SHORT DURATION
GALE WARNING. S-SW WINDS SAT INTO SAT EVE WILL VEER TO THE WNW AND
REMAIN GUSTY BEHIND THE FRONT SAT NIGHT INTO SUN MORNING...THEN
SETTLE DOWN AND BECOME SW LATE SUNDAY AS HIGH PRESSURE BUILDS IN.
ANOTHER ROUND OF UNSETTLED CONDITIONS IS POSSIBLE BY TUESDAY.
&&
.CLIMATE...
RECORD HIGH TEMPERATURES SATURDAY JANUARY 11
RIC 72/1975
ORF 75/1974
SBY 68/1975
ECG 75/1974
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 7 AM SATURDAY TO 6 AM EST SUNDAY FOR
ANZ635>637.
SMALL CRAFT ADVISORY FROM 4 AM SATURDAY TO 10 AM EST SUNDAY
FOR ANZ632>634.
SMALL CRAFT ADVISORY FROM 4 AM SATURDAY TO 6 AM EST SUNDAY FOR
ANZ630-631.
SMALL CRAFT ADVISORY FROM 7 AM SATURDAY TO 10 AM EST SUNDAY
FOR ANZ638.
SMALL CRAFT ADVISORY FROM 4 AM SATURDAY TO 4 PM EST SUNDAY FOR
ANZ650-652-654-656-658.
&&
$$
SYNOPSIS...MAM
NEAR TERM...MAM
SHORT TERM...AJZ/MAM
LONG TERM...SAM
AVIATION...JDM/DAP
MARINE...JDM
CLIMATE...
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
140 PM EST FRI JAN 10 2014
.SYNOPSIS...
HIGH PRESSURE MOVES OFFSHORE TODAY AND TONIGHT AS A SERIES OF WEAK
UPPER LEVEL TROUGHS TRACK ACROSS THE MID ATLANTIC REGION. A COLD
FRONT APPROACHES FROM THE WEST SATURDAY AND PUSHES THROUGH THE
REGION SATURDAY NIGHT EVENING. HIGH PRESSURE RETURNS FROM THE WEST
LATER SATURDAY NIGHT INTO SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
QUICK UPDATE TO REFLECT EXPIRATION OF FZRA ADVISORY. WHILE
AWOS/MESONET DATA REFLECT THAT TEMPS ARE AOA32 DEG ACROSS THE
AREA, WE HAVE HAD SEVERAL REPORTS OF LIGHT FZRA/ICY ROAD
CONDITIONS FROM EARLIER THIS MORNING ACROSS THE NOW EXPIRED ADVY
AREA. DID ISSUE AN SPS TO REFLECT SOME LINGERING ICY PATCHES
ACROSS THIS SAME AREA NW OF RIC METRO THROUGH LATE MORNING.
OTHERWISE...NO CHANGES NEEDED ATTM.
UPDATED PREV DISCUSSION...ISSUED 718 AM EST
THE LATEST SURFACE ANALYSIS INDICATES A ~1036MB SFC HIGH PRESSURE
CENTERED OFF CAPE COD...WITH A SFC RIDGE AXIS EXTENDING SW ALONG
THE PIEDMONT INTO NE GA...AND A COASTAL TROUGH NOW PRESENT OVER
THE NC COASTAL PLAIN INTO SE VA. THE LATEST REGIONAL RADAR MOSAIC
INDICATES AN AREA OF WARM ADVECTION EXTENDING FROM THE SOUTHERN
APPALACHIANS TO THE MID ATLANTIC. THE HRRR AND RUC BOTH SHOW
MOISTURE CONTINUING TO STREAM OVER THE AREA THROUGH THE DAY.
WARM/MOIST ADVECTION CONTINUES TODAY. THE SHORTWAVE TROUGH
RESPONSIBLE FOR THE MORNING PRECIP LIFTS TO THE NE THIS MORNING.
HOWEVER...ANOTHER MID-LEVEL WAVE LIFTS ACROSS THE REGION IN SSW
FLOW ALOFT THIS AFTERNOON. THIS WILL BRING ANOTHER ROUND OF RA TO
PRIMARILY CENTRAL PORTIONS OF THE AREA LATER THIS AFTERNOON.
HIGH TEMPERATURES WILL VARY FROM AROUND 40 NW TODAY WITH A CAD
WEDGE IN PLACE...TO NEAR 60 SE AS THE COASTAL FRONT MOVES INLAND.
WEAK FLOW AND ABUNDANT MOISTURE BELOW 700MB WILL RESULT IN
OVERCAST CONDITIONS THROUGHOUT TODAY.
TEMPERATURES SHOULD FALL VERY LITTLE TONIGHT (AND LIKELY RISE
TOWARD SATURDAY MORNING) AS THE SURFACE WARM FRONT LIFTS THROUGH
THE AREA...RESULTING IN WIDESPREAD STRATUS AND OCCASIONAL -RA/DZ.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
THE TROUGH PRESENTLY DIGGING FROM THE INTERMOUNTAIN WEST TOWARD THE
HIGH PLAINS PER GOES WATER VAPOR IMAGERY WILL CONTINUE TO AMPLIFY
ACROSS THE CENTRAL CONUS TODAY. INCREASINGLY ZONAL FLOW OVER THE
WESTERN US EVENTUALLY PUSHES THE TROUGH AXIS ACROSS THE APPALACHIANS
BY SAT/SAT EVENING. ASIDE FROM SUBTLE TIMING DIFFERENCES...GEFS/SREF
ENSEMBLE GUIDANCE ALONG WITH DETERMINISTIC ECMWF/GFS/NAM/CMC NOW
DEMONSTRATE DECENT AGREEMENT WITH THIS SYSTEM.
THERE IS A HIGH CONFIDENCE OF MEASURABLE RAIN IN THE SAT/SAT EVENING
TIMEFRAME. DEEP MOISTURE THROUGH 300MB COMBINED WITH STRONG LIFT
SHOULD PRODUCE MODERATE TO OCCASIONALLY HEAVY RA. HOWEVER...QPF
SHOULD LARGELY AVG 0.75-1.00IN DUE TO THE QUICK MOTION OF THE SYSTEM.
TEMPERATURES SHOULD BE VERY MILD AS THE SURFACE WARM FRONT LIFTS N
OF THE LOCAL AREA AND 850MB TEMPERATURE SURGE TO 10-12C. FORECAST
HIGHS FROM THE MID 60S TO AROUND 70 WILL BE MAINTAINED FOR MUCH OF
THE FORECAST AREA. THERE IS STILL SOME UNCERTAINTY WITH RESPECT TO
TEMPERATURE OVER NW PORTIONS...AS THERE IS A POSSIBILITY THAT A
MODIFIED WEDGE AIRMASS MAY REMAIN LOCKED IN...WHICH COULD KEEP HIGHS
IN THE 50S. BREEZY CONDITIONS DEVELOP FOR THE EASTERN THIRD OF THE
AREA...WITH A S WIND OF 15-20MPH WITH GUSTS TO AROUND 30MPH.
10/03Z SREF PROBS CONTINUE TO INDICATE A 90% CHANCE OF 2M DEWPOINTS
EXCEEDING 60F ACROSS S-CENTRAL/SE VA AND NE NC...AND 10/00Z NAM
INDICATES STRONG UPRIGHT FRONTOGENESIS FROM THE SURFACE TO
~850MB...WHICH ENHANCES LOW-LEVEL VERTICAL ASCENT. THIS IS PROGGED
TO OCCUR IN A SYNOPTIC ENVIRONMENT FEATURING 65-70KT 850-700MB LAYER
AVG SSW WIND...50-60KT OF SW 0-6KM BULK SHEAR...AND 250-500 J/KG ML
CAPE. GIVEN THE COMBINATION OF SYNOPTIC AND MESOSCALE
FACTORS...THERE IS AN INCREASING PROB FOR A FORCED LINE OF
CONVECTION (RARE BUT NOT UNPRECEDENTED FOR JAN) CAPABLE OF PRODUCING
STRONG TO POTENTIALLY DAMAGING WIND GUSTS...MAINLY ACROSS
S-CENTRAL/SE VA AND NE NC. BASED ON THE LATEST DATA...THE TIMING OF
THE GREATEST THREAT WOULD BE FROM SAT AFTERNOON INTO EARLY EVENING.
A TRANSITION DAY ON SUNDAY AS UPPER TROUGH PIVOTS OFFSHORE AND
QUASI-ZONAL FLOW BRING A CLEARING AND STILL-MILD DAY. HIGHS
GENERALLY IN THE 50S TO NEAR 60.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
STAYING CLOSE TO THE 12Z ECMWF FOR THE EXTENDED PERIOD. HI PRES WILL
SLIDE OFF THE CST AND OUT TO SEA SUN NGT THRU MON...PROVIDING MSTLY
CLEAR/PARTLY TO MOSTLY SUNNY CONDITIONS ACRS THE AREA. LATE MON NGT
THRU TUE...THE LATEST ECMWF BRINGS A SRN STREAM LO AND A COLD FRONT
TWD/AND ACRS THE AREA LATE MON NGT THRU TUE. AT THIS TIME...HAVE
SLGT CHC (20) POPS THEN CHC (30) POPS OVR THE REGION. THE FRONT
PUSHES OUT TO SEA TUE EVENG...BUT A SECONDARY BOUNDARY MAY CROSS THE
AREA ON WED. HAVE KEPT A DRY FCST FOR WED AT THIS TIME. DRIER AND
COOLER WNW FLO FILTERS IN FOR WED NGT THRU THU...AS HI PRES BLDS
INTO AND OVR THE REGION. MIN TEMPS WILL RANGE THRU THE 30S MON
MORNG...IN THE UPR 30S TO MID 40S TUE MORNG...IN THE 30S WED
MORNG...AND IN THE MID 20S TO LWR 30S THU MORNG. MAX TEMPS WILL
RANGE FM THE MID 50S TO LWR 60S MON...IN THE 50S TUE...IN THE MID
40S TO LWR 50S WED...AND IN THE 40S THU.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
-RA AND BR ACROSS THE AREA WILL CONTINUE THROUGH TONIGHT. SITES
NORTH AND WEST OF A WARM FRONT(KRIC AND KSBY) ARE EXPERIENCING
IFR CONDITIONS AND WILL CONTINUE TO DO SO UNTIL THE WARM FRONT
LIFTS THROUGH THOSE AREAS. EXPECT WINDS TO GUST OVER 20KT SAT
AS PRESSURE GRADIENT TIGHTENS BETWEEN APPROACHING TROUGH FROM THE
WEST AND HIGH PRESSURE OFFSHORE. SCATTERED SHOWERS ARE POSSIBLE
DURING THE LATE MORNING/EARLY AFTN HOURS SAT AS A COLD FRONT
PUSHES EAST.
OUTLOOK...A MORE ORGANIZED FRONTAL SYSTEM APPROACHES THE REGION ON
SATURDAY...WITH PERIODS OF RAIN AND WIDESPREAD MVFR/OCNL IFR
CONDITIONS AND GUSTY WINDS SAT AFTN. LOOK FOR DRY AND VFR CONDITIONS
SUNDAY AND MONDAY THEN DETERIORATING CONDS ONCE AGAIN AROUND
TUESDAY.
&&
.MARINE...
HIGH PRESSURE MOVES OFF THE NEW ENGLAND COAST TODAY...AS A TROF OF LOW
PRESSURE DEVELOPS ALONG THE CAROLINA COAST. E WINDS 10 KT OR LESS
THIS MORNING WILL BECOME SE 10-15 KT BY EVENING. SE WINDS WILL THEN
INCREASE TO 15 TO 20 KT LATE TONIGHT BEFORE BECOME S AND INCREASING
TO 15 TO 25 KT AND GUSTY FOR SAT...AS A WARM FRONT LIFTS NWRD THRU
THE AREA...FOLLOWED BY THE APPROACH OF A COLD FRONT. HAVE ISSUED
SCA`S BEGINNING EARLY SAT MORNING FOR ALL WATERS BASED ON GOOD
AGREEMENT IN MODELS FOR GUSTY WINDS DURING SAT INTO SAT NIGHT...
ALONG WITH SEAS BUILDING TO 5-9 FT. GALE FORCE WINDS ARE NOT
EXPECTED ATTM EXCEPT POSSIBLY IN A NARROW BAND OF CONVECTION THAT
MAY MOVE THRU WITH THE COLD FRONT LATE SAT. THIS CAN LIKELY BE
HANDLED WITH SPECIAL MARINE WARNINGS AS OPPOSED TO A SHORT DURATION
GALE WARNING. S-SW WINDS SAT INTO SAT EVE WILL VEER TO THE WNW AND
REMAIN GUSTY BEHIND THE FRONT SAT NIGHT INTO SUN MORNING...THEN
SETTLE DOWN AND BECOME SW LATE SUNDAY AS HIGH PRESSURE BUILDS IN.
ANOTHER ROUND OF UNSETTLED CONDITIONS IS POSSIBLE BY TUESDAY.
&&
.CLIMATE...
RECORD HIGH TEMPERATURES SATURDAY JANUARY 11
RIC 72/1975
ORF 75/1974
SBY 68/1975
ECG 75/1974
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 7 AM SATURDAY TO 6 AM EST SUNDAY FOR
ANZ635>638.
SMALL CRAFT ADVISORY FROM 4 AM SATURDAY TO 6 AM EST SUNDAY FOR
ANZ630>634-650-652-654-656-658.
&&
$$
SYNOPSIS...AJZ
NEAR TERM...AJZ
SHORT TERM...AJZ/MAM
LONG TERM...TMG
AVIATION...JDM/DAP
MARINE...JDM
CLIMATE...
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
940 AM EST FRI JAN 10 2014
.SYNOPSIS...
HIGH PRESSURE MOVES OFFSHORE TODAY AND TONIGHT AS A SERIES OF WEAK
UPPER LEVEL TROUGHS TRACK ACROSS THE MID ATLANTIC REGION. A COLD
FRONT APPROACHES FROM THE WEST SATURDAY AND PUSHES THROUGH THE
REGION SATURDAY NIGHT EVENING. HIGH PRESSURE RETURNS FROM THE WEST
LATER SATURDAY NIGHT INTO SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
QUICK UPDATE TO REFLECT EXPIRATION OF FZRA ADVISORY. WHILE
AWOS/MESONET DATA REFLECT THAT TEMPS ARE AOA32 DEG ACROSS THE
AREA, WE HAVE HAD SEVERAL REPORTS OF LIGHT FZRA/ICY ROAD
CONDITIONS FROM EARLIER THIS MORNING ACROSS THE NOW EXPIRED ADVY
AREA. DID ISSUE AN SPS TO REFLECT SOME LINGERING ICY PATCHES
ACROSS THIS SAME AREA NW OF RIC METRO THROUGH LATE MORNING.
OTHERWISE...NO CHANGES NEEDED ATTM.
UPDATED PREV DISCUSSION...ISSUED 718 AM EST
THE LATEST SURFACE ANALYSIS INDICATES A ~1036MB SFC HIGH PRESSURE
CENTERED OFF CAPE COD...WITH A SFC RIDGE AXIS EXTENDING SW ALONG
THE PIEDMONT INTO NE GA...AND A COASTAL TROUGH NOW PRESENT OVER
THE NC COASTAL PLAIN INTO SE VA. THE LATEST REGIONAL RADAR MOSAIC
INDICATES AN AREA OF WARM ADVECTION EXTENDING FROM THE SOUTHERN
APPALACHIANS TO THE MID ATLANTIC. THE HRRR AND RUC BOTH SHOW
MOISTURE CONTINUING TO STREAM OVER THE AREA THROUGH THE DAY.
WARM/MOIST ADVECTION CONTINUES TODAY. THE SHORTWAVE TROUGH
RESPONSIBLE FOR THE MORNING PRECIP LIFTS TO THE NE THIS MORNING.
HOWEVER...ANOTHER MID-LEVEL WAVE LIFTS ACROSS THE REGION IN SSW
FLOW ALOFT THIS AFTERNOON. THIS WILL BRING ANOTHER ROUND OF RA TO
PRIMARILY CENTRAL PORTIONS OF THE AREA LATER THIS AFTERNOON.
HIGH TEMPERATURES WILL VARY FROM AROUND 40 NW TODAY WITH A CAD
WEDGE IN PLACE...TO NEAR 60 SE AS THE COASTAL FRONT MOVES INLAND.
WEAK FLOW AND ABUNDANT MOISTURE BELOW 700MB WILL RESULT IN
OVERCAST CONDITIONS THROUGHOUT TODAY.
TEMPERATURES SHOULD FALL VERY LITTLE TONIGHT (AND LIKELY RISE
TOWARD SATURDAY MORNING) AS THE SURFACE WARM FRONT LIFTS THROUGH
THE AREA...RESULTING IN WIDESPREAD STRATUS AND OCCASIONAL -RA/DZ.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
THE TROUGH PRESENTLY DIGGING FROM THE INTERMOUNTAIN WEST TOWARD THE
HIGH PLAINS PER GOES WATER VAPOR IMAGERY WILL CONTINUE TO AMPLIFY
ACROSS THE CENTRAL CONUS TODAY. INCREASINGLY ZONAL FLOW OVER THE
WESTERN US EVENTUALLY PUSHES THE TROUGH AXIS ACROSS THE APPALACHIANS
BY SAT/SAT EVENING. ASIDE FROM SUBTLE TIMING DIFFERENCES...GEFS/SREF
ENSEMBLE GUIDANCE ALONG WITH DETERMINISTIC ECMWF/GFS/NAM/CMC NOW
DEMONSTRATE DECENT AGREEMENT WITH THIS SYSTEM.
THERE IS A HIGH CONFIDENCE OF MEASURABLE RAIN IN THE SAT/SAT EVENING
TIMEFRAME. DEEP MOISTURE THROUGH 300MB COMBINED WITH STRONG LIFT
SHOULD PRODUCE MODERATE TO OCCASIONALLY HEAVY RA. HOWEVER...QPF
SHOULD LARGELY AVG 0.75-1.00IN DUE TO THE QUICK MOTION OF THE SYSTEM.
TEMPERATURES SHOULD BE VERY MILD AS THE SURFACE WARM FRONT LIFTS N
OF THE LOCAL AREA AND 850MB TEMPERATURE SURGE TO 10-12C. FORECAST
HIGHS FROM THE MID 60S TO AROUND 70 WILL BE MAINTAINED FOR MUCH OF
THE FORECAST AREA. THERE IS STILL SOME UNCERTAINTY WITH RESPECT TO
TEMPERATURE OVER NW PORTIONS...AS THERE IS A POSSIBILITY THAT A
MODIFIED WEDGE AIRMASS MAY REMAIN LOCKED IN...WHICH COULD KEEP HIGHS
IN THE 50S. BREEZY CONDITIONS DEVELOP FOR THE EASTERN THIRD OF THE
AREA...WITH A S WIND OF 15-20MPH WITH GUSTS TO AROUND 30MPH.
10/03Z SREF PROBS CONTINUE TO INDICATE A 90% CHANCE OF 2M DEWPOINTS
EXCEEDING 60F ACROSS S-CENTRAL/SE VA AND NE NC...AND 10/00Z NAM
INDICATES STRONG UPRIGHT FRONTOGENESIS FROM THE SURFACE TO
~850MB...WHICH ENHANCES LOW-LEVEL VERTICAL ASCENT. THIS IS PROGGED
TO OCCUR IN A SYNOPTIC ENVIRONMENT FEATURING 65-70KT 850-700MB LAYER
AVG SSW WIND...50-60KT OF SW 0-6KM BULK SHEAR...AND 250-500 J/KG ML
CAPE. GIVEN THE COMBINATION OF SYNOPTIC AND MESOSCALE
FACTORS...THERE IS AN INCREASING PROB FOR A FORCED LINE OF
CONVECTION (RARE BUT NOT UNPRECEDENTED FOR JAN) CAPABLE OF PRODUCING
STRONG TO POTENTIALLY DAMAGING WIND GUSTS...MAINLY ACROSS
S-CENTRAL/SE VA AND NE NC. BASED ON THE LATEST DATA...THE TIMING OF
THE GREATEST THREAT WOULD BE FROM SAT AFTERNOON INTO EARLY EVENING.
A TRANSITION DAY ON SUNDAY AS UPPER TROUGH PIVOTS OFFSHORE AND
QUASI-ZONAL FLOW BRING A CLEARING AND STILL-MILD DAY. HIGHS
GENERALLY IN THE 50S TO NEAR 60.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
STAYING CLOSE TO THE 12Z ECMWF FOR THE EXTENDED PERIOD. HI PRES WILL
SLIDE OFF THE CST AND OUT TO SEA SUN NGT THRU MON...PROVIDING MSTLY
CLEAR/PARTLY TO MOSTLY SUNNY CONDITIONS ACRS THE AREA. LATE MON NGT
THRU TUE...THE LATEST ECMWF BRINGS A SRN STREAM LO AND A COLD FRONT
TWD/AND ACRS THE AREA LATE MON NGT THRU TUE. AT THIS TIME...HAVE
SLGT CHC (20) POPS THEN CHC (30) POPS OVR THE REGION. THE FRONT
PUSHES OUT TO SEA TUE EVENG...BUT A SECONDARY BOUNDARY MAY CROSS THE
AREA ON WED. HAVE KEPT A DRY FCST FOR WED AT THIS TIME. DRIER AND
COOLER WNW FLO FILTERS IN FOR WED NGT THRU THU...AS HI PRES BLDS
INTO AND OVR THE REGION. MIN TEMPS WILL RANGE THRU THE 30S MON
MORNG...IN THE UPR 30S TO MID 40S TUE MORNG...IN THE 30S WED
MORNG...AND IN THE MID 20S TO LWR 30S THU MORNG. MAX TEMPS WILL
RANGE FM THE MID 50S TO LWR 60S MON...IN THE 50S TUE...IN THE MID
40S TO LWR 50S WED...AND IN THE 40S THU.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
-RA WILL BEGIN TO SPREAD INTO WESTERN PORTIONS OF THE FA AROUND
DAYBREAK...AFFECTING KRIC BY 11Z-12Z. MVFR CONDITIONS WILL THEN
OVERSPREAD THE ENTIRE AREA BY LATE MORNING...AND LIKELY CONTINUES
INTO TONIGHT. BEST CHANCE FOR IFR CONDITIONS WILL BE AT KRIC.
OUTLOOK...A MORE ORGANIZED FRONTAL SYSTEM APPROACHES THE REGION ON
SATURDAY...WITH PERIODS OF RAIN AND WIDESPREAD MVFR/OCNL IFR
CONDITIONS AND GUSTY WINDS. LOOK FOR DRY AND VFR CONDITIONS SUNDAY
AND MONDAY THEN DETERIORATING CONDS ONCE AGAIN AROUND TUESDAY.
&&
.MARINE...
HIGH PRESSURE MOVES OFF THE NEW ENGLAND COAST TODAY...AS A TROF OF LOW
PRESSURE DEVELOPS ALONG THE CAROLINA COAST. E WINDS 10 KT OR LESS
THIS MORNING WILL BECOME SE 10-15 KT BY EVENING. SE WINDS WILL THEN
INCREASE TO 15 TO 20 KT LATE TONIGHT BEFORE BECOME S AND INCREASING
TO 15 TO 25 KT AND GUSTY FOR SAT...AS A WARM FRONT LIFTS NWRD THRU
THE AREA...FOLLOWED BY THE APPROACH OF A COLD FRONT. HAVE ISSUED
SCA`S BEGINNING EARLY SAT MORNING FOR ALL WATERS BASED ON GOOD
AGREEMENT IN MODELS FOR GUSTY WINDS DURING SAT INTO SAT NIGHT...
ALONG WITH SEAS BUILDING TO 5-9 FT. GALE FORCE WINDS ARE NOT
EXPECTED ATTM EXCEPT POSSIBLY IN A NARROW BAND OF CONVECTION THAT
MAY MOVE THRU WITH THE COLD FRONT LATE SAT. THIS CAN LIKELY BE
HANDLED WITH SPECIAL MARINE WARNINGS AS OPPOSED TO A SHORT DURATION
GALE WARNING. S-SW WINDS SAT INTO SAT EVE WILL VEER TO THE WNW AND
REMAIN GUSTY BEHIND THE FRONT SAT NIGHT INTO SUN MORNING...THEN
SETTLE DOWN AND BECOME SW LATE SUNDAY AS HIGH PRESSURE BUILDS IN.
ANOTHER ROUND OF UNSETTLED CONDITIONS IS POSSIBLE BY TUESDAY.
&&
.CLIMATE...
RECORD HIGH TEMPERATURES SATURDAY JANUARY 11
RIC 72/1975
ORF 75/1974
SBY 68/1975
ECG 75/1974
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 7 AM SATURDAY TO 6 AM EST SUNDAY FOR
ANZ635>638.
SMALL CRAFT ADVISORY FROM 4 AM SATURDAY TO 6 AM EST SUNDAY FOR
ANZ630>634-650-652-654-656-658.
&&
$$
SYNOPSIS...AJZ
NEAR TERM...AJZ
SHORT TERM...AJZ/MAM
LONG TERM...TMG
AVIATION...JDM
MARINE...JDM
CLIMATE...
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
718 AM EST FRI JAN 10 2014
.SYNOPSIS...
HIGH PRESSURE MOVES OFFSHORE TODAY AND TONIGHT AS A SERIES OF WEAK
UPPER LEVEL TROUGHS TRACK ACROSS THE MID ATLANTIC REGION. A COLD
FRONT APPROACHES FROM THE WEST SATURDAY AND PUSHES THROUGH THE
REGION SATURDAY NIGHT EVENING. HIGH PRESSURE RETURNS FROM THE WEST
LATER SATURDAY NIGHT INTO SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE LATEST SURFACE ANALYSIS INDICATES A ~1036MB SFC HIGH PRESSURE
CENTERED OFF CAPE COD...WITH A SFC RIDGE AXIS EXTENDING SW ALONG
THE PIEDMONT INTO NE GA...AND A COASTAL TROUGH NOW PRESENT OVER
THE NC COASTAL PLAIN INTO SE VA. THE LATEST REGIONAL RADAR MOSAIC
INDICATES AN AREA OF WARM ADVECTION EXTENDING FROM THE SOUTHERN
APPALACHIANS TO THE MID ATLANTIC. THE HRRR AND RUC BOTH SHOW
MOISTURE CONTINUING TO STREAM OVER THE AREA THROUGH THE DAY.
MODEL THICKNESSES AND BUFKIT SOUNDINGS INDICATE THE POTENTIAL FOR
A LIGHT MIX (MAINLY NW A LINE FROM DAN-OFP-BWI) EARLY THIS
MORNING...WHICH IS SUPPORTED BY REGIONAL OBS OVER THE CENTRAL VA
PIEDMONT. BASED ON LATEST FORECAST SOUNDINGS...EXPECT LIGHT
PRECIP TO BEGIN AS SLEET/IP...BEFORE TRANSITIONING QUICKLY TO
FZRA. ANY QPF WILL BE VERY LIGHT (LESS THAN 0.10IN).
HOWEVER...CONSIDERING THE TIMING OF ANY LGT PRECIP COINCIDING WITH
THE EARLY PORTION OF THE MORNING RUSH...A SHORT DURATION FZRA
ADVISORY WILL REMAIN IN AFFECT OVER THE PIEDMONT NW OF RIC METRO
THROUGH 14Z. OF NOTE...MECKLENBURG AND LUNENBURG COUNTIES HAVE
BEEN REMOVED FROM THE ADVISORY AS CURRENT OBSERVATIONAL DATA AND
MODEL DATA DOES NOT SUPPORT THE POTENTIAL FOR EVEN MINOR ICING.
POINTS FARTHER EAST...SUCH AS THE NORTHERN NECK AND INTERIOR LOWER
MD EASTERN SHORE COULD EXPERIENCE SOME IP AT THE ONSET.
HOWEVER...THERE IS LITTLE SUPPORT FOR ICING IN THESE LOCATIONS.
ANY LINGERING FZRA THIS MORNING SHOULD TRANSITION TO RA AFTER 9 AM
THIS MORNING.
WARM/MOIST ADVECTION CONTINUES TODAY. THE SHORTWAVE TROUGH
RESPONSIBLE FOR THE MORNING PRECIP LIFTS TO THE NE THIS MORNING.
HOWEVER...ANOTHER MID-LEVEL WAVE LIFTS ACROSS THE REGION IN SSW
FLOW ALOFT THIS AFTERNOON. THIS WILL BRING ANOTHER ROUND OF RA TO
PRIMARILY CENTRAL PORTIONS OF THE AREA LATER THIS AFTERNOON.
HIGH TEMPERATURES WILL VARY FROM AROUND 40 NW TODAY WITH A CAD
WEDGE IN PLACE...TO NEAR 60 SE AS THE COASTAL FRONT MOVES INLAND.
WEAK FLOW AND ABUNDANT MOISTURE BELOW 700MB WILL RESULT IN
OVERCAST CONDITIONS THROUGHOUT TODAY.
TEMPERATURES SHOULD FALL VERY LITTLE TONIGHT (AND LIKELY RISE
TOWARD SATURDAY MORNING) AS THE SURFACE WARM FRONT LIFTS THROUGH
THE AREA...RESULTING IN WIDESPREAD STRATUS AND OCCASIONAL -RA/DZ.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
THE TROUGH PRESENTLY DIGGING FROM THE INTERMOUNTAIN WEST TOWARD THE
HIGH PLAINS PER GOES WATER VAPOR IMAGERY WILL CONTINUE TO AMPLIFY
ACROSS THE CENTRAL CONUS TODAY. INCREASINGLY ZONAL FLOW OVER THE
WESTERN US EVENTUALLY PUSHES THE TROUGH AXIS ACROSS THE APPALACHIANS
BY SAT/SAT EVENING. ASIDE FROM SUBTLE TIMING DIFFERENCES...GEFS/SREF
ENSEMBLE GUIDANCE ALONG WITH DETERMINISTIC ECMWF/GFS/NAM/CMC NOW
DEMONSTRATE DECENT AGREEMENT WITH THIS SYSTEM.
THERE IS A HIGH CONFIDENCE OF MEASURABLE RAIN IN THE SAT/SAT EVENING
TIMEFRAME. DEEP MOISTURE THROUGH 300MB COMBINED WITH STRONG LIFT
SHOULD PRODUCE MODERATE TO OCCASIONALLY HEAVY RA. HOWEVER...QPF
SHOULD LARGELY AVG 0.75-1.00IN DUE TO THE QUICK MOTION OF THE SYSTEM.
TEMPERATURES SHOULD BE VERY MILD AS THE SURFACE WARM FRONT LIFTS N
OF THE LOCAL AREA AND 850MB TEMPERATURE SURGE TO 10-12C. FORECAST
HIGHS FROM THE MID 60S TO AROUND 70 WILL BE MAINTAINED FOR MUCH OF
THE FORECAST AREA. THERE IS STILL SOME UNCERTAINTY WITH RESPECT TO
TEMPERATURE OVER NW PORTIONS...AS THERE IS A POSSIBILITY THAT A
MODIFIED WEDGE AIRMASS MAY REMAIN LOCKED IN...WHICH COULD KEEP HIGHS
IN THE 50S. BREEZY CONDITIONS DEVELOP FOR THE EASTERN THIRD OF THE
AREA...WITH A S WIND OF 15-20MPH WITH GUSTS TO AROUND 30MPH.
10/03Z SREF PROBS CONTINUE TO INDICATE A 90% CHANCE OF 2M DEWPOINTS
EXCEEDING 60F ACROSS S-CENTRAL/SE VA AND NE NC...AND 10/00Z NAM
INDICATES STRONG UPRIGHT FRONTOGENESIS FROM THE SURFACE TO
~850MB...WHICH ENHANCES LOW-LEVEL VERTICAL ASCENT. THIS IS PROGGED
TO OCCUR IN A SYNOPTIC ENVIRONMENT FEATURING 65-70KT 850-700MB LAYER
AVG SSW WIND...50-60KT OF SW 0-6KM BULK SHEAR...AND 250-500 J/KG ML
CAPE. GIVEN THE COMBINATION OF SYNOPTIC AND MESOSCALE
FACTORS...THERE IS AN INCREASING PROB FOR A FORCED LINE OF
CONVECTION (RARE BUT NOT UNPRECEDENTED FOR JAN) CAPABLE OF PRODUCING
STRONG TO POTENTIALLY DAMAGING WIND GUSTS...MAINLY ACROSS
S-CENTRAL/SE VA AND NE NC. BASED ON THE LATEST DATA...THE TIMING OF
THE GREATEST THREAT WOULD BE FROM SAT AFTERNOON INTO EARLY EVENING.
A TRANSITION DAY ON SUNDAY AS UPPER TROUGH PIVOTS OFFSHORE AND
QUASI-ZONAL FLOW BRING A CLEARING AND STILL-MILD DAY. HIGHS
GENERALLY IN THE 50S TO NEAR 60.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
STAYING CLOSE TO THE 12Z ECMWF FOR THE EXTENDED PERIOD. HI PRES WILL
SLIDE OFF THE CST AND OUT TO SEA SUN NGT THRU MON...PROVIDING MSTLY
CLEAR/PARTLY TO MOSTLY SUNNY CONDITIONS ACRS THE AREA. LATE MON NGT
THRU TUE...THE LATEST ECMWF BRINGS A SRN STREAM LO AND A COLD FRONT
TWD/AND ACRS THE AREA LATE MON NGT THRU TUE. AT THIS TIME...HAVE
SLGT CHC (20) POPS THEN CHC (30) POPS OVR THE REGION. THE FRONT
PUSHES OUT TO SEA TUE EVENG...BUT A SECONDARY BOUNDARY MAY CROSS THE
AREA ON WED. HAVE KEPT A DRY FCST FOR WED AT THIS TIME. DRIER AND
COOLER WNW FLO FILTERS IN FOR WED NGT THRU THU...AS HI PRES BLDS
INTO AND OVR THE REGION. MIN TEMPS WILL RANGE THRU THE 30S MON
MORNG...IN THE UPR 30S TO MID 40S TUE MORNG...IN THE 30S WED
MORNG...AND IN THE MID 20S TO LWR 30S THU MORNG. MAX TEMPS WILL
RANGE FM THE MID 50S TO LWR 60S MON...IN THE 50S TUE...IN THE MID
40S TO LWR 50S WED...AND IN THE 40S THU.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
-RA WILL BEGIN TO SPREAD INTO WESTERN PORTIONS OF THE FA AROUND
DAYBREAK...AFFECTING KRIC BY 11Z-12Z. MVFR CONDITIONS WILL THEN
OVERSPREAD THE ENTIRE AREA BY LATE MORNING...AND LIKELY CONTINUES
INTO TONIGHT. BEST CHANCE FOR IFR CONDITIONS WILL BE AT KRIC.
OUTLOOK...A MORE ORGANIZED FRONTAL SYSTEM APPROACHES THE REGION ON
SATURDAY...WITH PERIODS OF RAIN AND WIDESPREAD MVFR/OCNL IFR
CONDITIONS AND GUSTY WINDS. LOOK FOR DRY AND VFR CONDITIONS SUNDAY
AND MONDAY THEN DETERIORATING CONDS ONCE AGAIN AROUND TUESDAY.
&&
.MARINE...
HIGH PRESSURE MOVES OFF THE NEW ENGLAND COAST TODAY...AS A TROF OF LOW
PRESSURE DEVELOPS ALONG THE CAROLINA COAST. E WINDS 10 KT OR LESS
THIS MORNING WILL BECOME SE 10-15 KT BY EVENING. SE WINDS WILL THEN
INCREASE TO 15 TO 20 KT LATE TONIGHT BEFORE BECOME S AND INCREASING
TO 15 TO 25 KT AND GUSTY FOR SAT...AS A WARM FRONT LIFTS NWRD THRU
THE AREA...FOLLOWED BY THE APPROACH OF A COLD FRONT. HAVE ISSUED
SCA`S BEGINNING EARLY SAT MORNING FOR ALL WATERS BASED ON GOOD
AGREEMENT IN MODELS FOR GUSTY WINDS DURING SAT INTO SAT NIGHT...
ALONG WITH SEAS BUILDING TO 5-9 FT. GALE FORCE WINDS ARE NOT
EXPECTED ATTM EXCEPT POSSIBLY IN A NARROW BAND OF CONVECTION THAT
MAY MOVE THRU WITH THE COLD FRONT LATE SAT. THIS CAN LIKELY BE
HANDLED WITH SPECIAL MARINE WARNINGS AS OPPOSED TO A SHORT DURATION
GALE WARNING. S-SW WINDS SAT INTO SAT EVE WILL VEER TO THE WNW AND
REMAIN GUSTY BEHIND THE FRONT SAT NIGHT INTO SUN MORNING...THEN
SETTLE DOWN AND BECOME SW LATE SUNDAY AS HIGH PRESSURE BUILDS IN.
ANOTHER ROUND OF UNSETTLED CONDITIONS IS POSSIBLE BY TUESDAY.
&&
.CLIMATE...
RECORD HIGH TEMPERATURES SATURDAY JANUARY 11
RIC 72/1975
ORF 75/1974
SBY 68/1975
ECG 75/1974
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...FREEZING RAIN ADVISORY UNTIL 9 AM EST THIS MORNING FOR VAZ048-
049-060>064-067>069.
MARINE...SMALL CRAFT ADVISORY FROM 4 AM SATURDAY TO 6 AM EST SUNDAY FOR
ANZ630>634-650-652-654-656-658.
SMALL CRAFT ADVISORY FROM 7 AM SATURDAY TO 6 AM EST SUNDAY FOR
ANZ635>638.
&&
$$
SYNOPSIS...AJZ
NEAR TERM...AJZ
SHORT TERM...AJZ/MAM
LONG TERM...TMG
AVIATION...JDM
MARINE...JDM
CLIMATE...AJZ
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
416 AM EST FRI JAN 10 2014
.SYNOPSIS...
HIGH PRESSURE MOVES OFFSHORE TODAY AND TONIGHT AS A SERIES OF WEAK
UPPER LEVEL TROUGHS TRACK ACROSS THE MID ATLANTIC REGION. A COLD
FRONT APPROACHES FROM THE WEST SATURDAY AND PUSHES THROUGH THE
REGION SATURDAY NIGHT EVENING. HIGH PRESSURE RETURNS FROM THE WEST
LATER SATURDAY NIGHT INTO SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE LATEST SURFACE ANALYSIS INDICATES A ~1038MB SFC HIGH PRESSURE
CENTERED OVER CAPE COD...WITH A SFC RIDGE AXIS EXTENDING SW ALONG
THE PIEDMONT INTO NE GA. LATEST WATER VAPOR SHOWS NICE PV MAX
MOVING FROM OH INTO WRN PA. THIS IS PUSHING CLOUDS ACROSS INTO THE
NORTHERN SECTIONS OF THE CWA BUT ALL PRECIP WITH THIS HAS STAYED
TO THE NORTH AND WEST OF THE AREA. ANOTHER AREA OF WARM ADVECTION
IS BEGINNING TO DEVELOP TO THE SOUTHWEST OVER THE WRN CAROLINAS.
THE HRRR AND RUC BOTH SHOW MOISTURE FROM THIS MOVING NORTH AND
MERGING WITH THE NRN SYSTEM. THIS WILL BRING THE PRECIP INTO THE
WRN SECTIONS NEAR SUNRISE. MOST MODELS AGREE THAT THE ONSET OCCURS
BETWEEN 10Z AND 12Z.
AS OF 06Z...CLOUDS HAVE OVERSPREAD MUCH OF THE LOCAL AREA. THIS
HAS ALLOWED TEMPERATURES TO RISE A FEW DEGREES...WITH A MORE
NOTABLE RISE FOR SE COASTAL LOCATIONS AS A COASTAL FRONT BEGINS TO
INTRUDE. DEWPOINTS REMAIN IN THE LOW/MID 20S OVER THE NW PIEDMONT
COUNTIES...AND THIS WILL COMPLICATE PRECIP TYPE AS MOISTURE
ARRIVES TOWARD MORNING.
MODEL THICKNESSES AND BUFKIT SOUNDINGS INDICATE THE POTENTIAL FOR
A LIGHT MIX (MAINLY NW A LINE FROM DAN-OFP-BWI) TOWARD FRIDAY
MORNING. BASED ON LATEST FORECAST SOUNDINGS...EXPECT LIGHT PRECIP
TO BEGIN AS SLEET/IP...BEFORE TRANSITIONING QUICKLY TO FZRA. ANY
QPF WILL BE VERY LIGHT (LESS THAN 0.10IN). HOWEVER...CONSIDERING
THE TIMING OF ANY LGT PRECIP COINCIDING WITH THE EARLY PORTION OF
THE MORNING RUSH...A SHORT DURATION FZRA ADVISORY WILL REMAIN IN
AFFECT OVER THE PIEDMONT NW OF RIC METRO THROUGH 14Z. OF
NOTE...MECKLENBURG AND LUNENBURG COUNTIES HAVE BEEN REMOVED FROM
THE ADVISORY AS CURRENT OBSERVATIONAL DATA AND MODEL DATA DOES NOT
SUPPORT THE POTENTIAL FOR EVEN MINOR ICING. POINTS FARTHER
EAST...SUCH AS THE NORTHERN NECK AND INTERIOR LOWER MD EASTERN
SHORE COULD EXPERIENCE SOME IP AT THE ONSET. HOWEVER...THERE IS
LITTLE SUPPORT FOR ICING IN THESE LOCATIONS. ANY LINGERING FZRA
THIS MORNING SHOULD TRANSITION TO RA AFTER 9 AM THIS MORNING.
WARM/MOIST ADVECTION CONTINUES TODAY. THE SHORTWAVE TROUGH
RESPONSIBLE FOR THE MORNING PRECIP LIFTS TO THE NE THIS MORNING.
HOWEVER...ANOTHER MID-LEVEL WAVE LIFTS ACROSS THE REGION IN SSW
FLOW ALOFT THIS AFTERNOON. THIS WILL BRING ANOTHER ROUND OF RA TO
PRIMARILY CENTRAL PORTIONS OF THE AREA LATER THIS AFTERNOON.
HIGH TEMPERATURES WILL VARY FROM AROUND 40 NW TODAY WITH A CAD
WEDGE IN PLACE...TO NEAR 60 SE AS THE COASTAL FRONT MOVES INLAND.
WEAK FLOW AND ABUNDANT MOISTURE BELOW 700MB WILL RESULT IN
OVERCAST CONDITIONS THROUGHOUT TODAY.
TEMPERATURES SHOULD FALL VERY LITTLE TONIGHT (AND LIKELY RISE
TOWARD SATURDAY MORNING) AS THE SURFACE WARM FRONT LIFTS THROUGH
THE AREA...RESULTING IN WIDESPREAD STRATUS AND OCCASIONAL -RA/DZ.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
THE TROUGH PRESENTLY DIGGING FROM THE INTERMOUNTAIN WEST TOWARD THE
HIGH PLAINS PER GOES WATER VAPOR IMAGERY WILL CONTINUE TO AMPLIFY
ACROSS THE CENTRAL CONUS TODAY. INCREASINGLY ZONAL FLOW OVER THE
WESTERN US EVENTUALLY PUSHES THE TROUGH AXIS ACROSS THE APPALACHIANS
BY SAT/SAT EVENING. ASIDE FROM SUBTLE TIMING DIFFERENCES...GEFS/SREF
ENSEMBLE GUIDANCE ALONG WITH DETERMINISTIC ECMWF/GFS/NAM/CMC NOW
DEMONSTRATE DECENT AGREEMENT WITH THIS SYSTEM.
THERE IS A HIGH CONFIDENCE OF MEASURABLE RAIN IN THE SAT/SAT EVENING
TIMEFRAME. DEEP MOISTURE THROUGH 300MB COMBINED WITH STRONG LIFT
SHOULD PRODUCE MODERATE TO OCCASIONALLY HEAVY RA. HOWEVER...QPF
SHOULD LARGELY AVG 0.75-1.00IN DUE TO THE QUICK MOTION OF THE SYSTEM.
TEMPERATURES SHOULD BE VERY MILD AS THE SURFACE WARM FRONT LIFTS N
OF THE LOCAL AREA AND 850MB TEMPERATURE SURGE TO 10-12C. FORECAST
HIGHS FROM THE MID 60S TO AROUND 70 WILL BE MAINTAINED FOR MUCH OF
THE FORECAST AREA. THERE IS STILL SOME UNCERTAINTY WITH RESPECT TO
TEMPERATURE OVER NW PORTIONS...AS THERE IS A POSSIBILITY THAT A
MODIFIED WEDGE AIRMASS MAY REMAIN LOCKED IN...WHICH COULD KEEP HIGHS
IN THE 50S. BREEZY CONDITIONS DEVELOP FOR THE EASTERN THIRD OF THE
AREA...WITH A S WIND OF 15-20MPH WITH GUSTS TO AROUND 30MPH.
10/03Z SREF PROBS CONTINUE TO INDICATE A 90% CHANCE OF 2M DEWPOINTS
EXCEEDING 60F ACROSS S-CENTRAL/SE VA AND NE NC...AND 10/00Z NAM
INDICATES STRONG UPRIGHT FRONTOGENESIS FROM THE SURFACE TO
~850MB...WHICH ENHANCES LOW-LEVEL VERTICAL ASCENT. THIS IS PROGGED
TO OCCUR IN A SYNOPTIC ENVIRONMENT FEATURING 65-70KT 850-700MB LAYER
AVG SSW WIND...50-60KT OF SW 0-6KM BULK SHEAR...AND 250-500 J/KG ML
CAPE. GIVEN THE COMBINATION OF SYNOPTIC AND MESOSCALE
FACTORS...THERE IS AN INCREASING PROB FOR A FORCED LINE OF
CONVECTION (RARE BUT NOT UNPRECEDENTED FOR JAN) CAPABLE OF PRODUCING
STRONG TO POTENTIALLY DAMAGING WIND GUSTS...MAINLY ACROSS
S-CENTRAL/SE VA AND NE NC. BASED ON THE LATEST DATA...THE TIMING OF
THE GREATEST THREAT WOULD BE FROM SAT AFTERNOON INTO EARLY EVENING.
A TRANSITION DAY ON SUNDAY AS UPPER TROUGH PIVOTS OFFSHORE AND
QUASI-ZONAL FLOW BRING A CLEARING AND STILL-MILD DAY. HIGHS
GENERALLY IN THE 50S TO NEAR 60.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
STAYING CLOSE TO THE 12Z ECMWF FOR THE EXTENDED PERIOD. HI PRES WILL
SLIDE OFF THE CST AND OUT TO SEA SUN NGT THRU MON...PROVIDING MSTLY
CLEAR/PARTLY TO MOSTLY SUNNY CONDITIONS ACRS THE AREA. LATE MON NGT
THRU TUE...THE LATEST ECMWF BRINGS A SRN STREAM LO AND A COLD FRONT
TWD/AND ACRS THE AREA LATE MON NGT THRU TUE. AT THIS TIME...HAVE
SLGT CHC (20) POPS THEN CHC (30) POPS OVR THE REGION. THE FRONT
PUSHES OUT TO SEA TUE EVENG...BUT A SECONDARY BOUNDARY MAY CROSS THE
AREA ON WED. HAVE KEPT A DRY FCST FOR WED AT THIS TIME. DRIER AND
COOLER WNW FLO FILTERS IN FOR WED NGT THRU THU...AS HI PRES BLDS
INTO AND OVR THE REGION. MIN TEMPS WILL RANGE THRU THE 30S MON
MORNG...IN THE UPR 30S TO MID 40S TUE MORNG...IN THE 30S WED
MORNG...AND IN THE MID 20S TO LWR 30S THU MORNG. MAX TEMPS WILL
RANGE FM THE MID 50S TO LWR 60S MON...IN THE 50S TUE...IN THE MID
40S TO LWR 50S WED...AND IN THE 40S THU.
&&
.AVIATION /09Z FRIDAY THROUGH TUESDAY/...
-RA WILL BEGIN TO SPREAD INTO WESTERN PORTIONS OF THE FA AROUND
DAYBREAK...AFFECTING KRIC BY 11Z-12Z. MVFR CONDITIONS WILL THEN
OVERSPREAD THE ENTIRE AREA BY LATE MORNING...AND LIKELY CONTINUES
INTO TONIGHT. BEST CHANCE FOR IFR CONDITIONS WILL BE AT KRIC.
OUTLOOK...A MORE ORGANIZED FRONTAL SYSTEM APPROACHES THE REGION ON
SATURDAY...WITH PERIODS OF RAIN AND WIDESPREAD MVFR/OCNL IFR
CONDITIONS AND GUSTY WINDS. LOOK FOR DRY AND VFR CONDITIONS SUNDAY
AND MONDAY THEN DETERIORATING CONDS ONCE AGAIN AROUND TUESDAY.
&&
.MARINE...
HIGH PRESSURE MOVES OFF THE NEW ENGLAND COAST TODAY...AS A TROF OF LOW
PRESSURE DEVELOPS ALONG THE CAROLINA COAST. E WINDS 10 KT OR LESS
THIS MORNING WILL BECOME SE 10-15 KT BY EVENING. SE WINDS WILL THEN
INCREASE TO 15 TO 20 KT LATE TONIGHT BEFORE BECOME S AND INCREASING
TO 15 TO 25 KT AND GUSTY FOR SAT...AS A WARM FRONT LIFTS NWRD THRU
THE AREA...FOLLOWED BY THE APPROACH OF A COLD FRONT. HAVE ISSUED
SCA`S BEGINNING EARLY SAT MORNING FOR ALL WATERS BASED ON GOOD
AGREEMENT IN MODELS FOR GUSTY WINDS DURING SAT INTO SAT NIGHT...
ALONG WITH SEAS BUILDING TO 5-9 FT. GALE FORCE WINDS ARE NOT
EXPECTED ATTM EXCEPT POSSIBLY IN A NARROW BAND OF CONVECTION THAT
MAY MOVE THRU WITH THE COLD FRONT LATE SAT. THIS CAN LIKELY BE
HANDLED WITH SPECIAL MARINE WARNINGS AS OPPOSED TO A SHORT DURATION
GALE WARNING. S-SW WINDS SAT INTO SAT EVE WILL VEER TO THE WNW AND
REMAIN GUSTY BEHIND THE FRONT SAT NIGHT INTO SUN MORNING...THEN
SETTLE DOWN AND BECOME SW LATE SUNDAY AS HIGH PRESSURE BUILDS IN.
ANOTHER ROUND OF UNSETTLED CONDITIONS IS POSSIBLE BY TUESDAY.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...FREEZING RAIN ADVISORY UNTIL 9 AM EST THIS MORNING FOR VAZ048-
049-060>064-067>069.
MARINE...SMALL CRAFT ADVISORY FROM 4 AM SATURDAY TO 6 AM EST SUNDAY FOR
ANZ630>634-650-652-654-656-658.
SMALL CRAFT ADVISORY FROM 7 AM SATURDAY TO 6 AM EST SUNDAY FOR
ANZ635>638.
&&
$$
SYNOPSIS...AJZ
NEAR TERM...AJZ
SHORT TERM...AJZ/MAM
LONG TERM...TMG
AVIATION...JDM
MARINE...JDM
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
138 AM EST FRI JAN 10 2014
.SYNOPSIS...
HIGH PRESSURE BUILDS OVER NEW ENGLAND OVERNIGHT AS A TROUGH OF LOW
PRESSURE DEVELOPS ALONG THE CAROLINA COAST. HIGH PRESSURE MOVES
OFFSHORE FRIDAY AS A WEAK UPPER LEVEL TROUGH PASSES ACROSS THE MID
ATLANTIC. A COLD FRONT APPROACHES FROM THE WEST SATURDAY AND
PUSHES THROUGH THE REGION SATURDAY NIGHT. HIGH PRESSURE RETURNS
FROM THE WEST SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
THE LATEST SURFACE ANALYSIS INDICATES A ~1038MB SFC HIGH PRESSURE
CENTERED OVER CAPE COD...WITH A SFC RIDGE AXIS EXTENDING SW ALONG
THE PIEDMONT INTO NE GA. LATEST WATER VAPOR SHOWS NICE PV MAX
MOVING FROM OH INTO WRN PA. THIS IS PUSHING CLOUDS ACROSS INTO THE
NORTHERN SECTIONS OF THE CWA BUT ALL PRECIP WITH THIS HAS STAYED
TO THE NORTH AND WEST OF THE AREA. ANOTHER AREA OF WARM ADVECTION
IS BEGINNING TO DEVELOP TO THE SOUTHWEST OVER THE WRN CAROLINAS.
THE HRRR AND RUC BOTH SHOW MOISTURE FROM THIS MOVING NORTH AND
MERGING WITH THE NRN SYSTEM. THIS WILL BRING THE PRECIP INTO THE
WRN SECTIONS NEAR SUNRISE. MOST MODELS AGREE THAT THE ONSET OCCURS
BETWEEN 10Z AND 12Z.
AS OF 06Z...CLOUDS HAVE OVERSPREAD MUCH OF THE LOCAL AREA. THIS
HAS ALLOWED TEMPERATURES TO RISE A FEW DEGREES...WITH A MORE
NOTABLE RISE FOR SE COASTAL LOCATIONS AS A COASTAL FRONT BEGINS TO
INTRUDE. DEWPOINTS REMAIN IN THE LOW/MID 20S OVER THE NW PIEDMONT
COUNTIES...AND THIS WILL COMPLICATE PRECIP TYPE AS MOISTURE
ARRIVES TOWARD MORNING.
MODEL THICKNESSES AND BUFKIT SOUNDINGS INDICATE THE POTENTIAL FOR
A LIGHT MIX (MAINLY NW A LINE FROM DAN-OFP-BWI) TOWARD FRIDAY
MORNING. BASED ON LATEST FORECAST SOUNDINGS...EXPECT LIGHT PRECIP
TO BEGIN AS SLEET/IP...BEFORE TRANSITIONING QUICKLY TO FZRA. ANY
QPF WILL BE VERY LIGHT (LESS THAN 0.10IN). HOWEVER...CONSIDERING
THE TIMING OF ANY LGT PRECIP COINCIDING WITH THE EARLY PORTION OF
THE MORNING RUSH...A SHORT DURATION FZRA ADVISORY WILL REMAIN IN
AFFECT OVER THE PIEDMONT NW OF RIC METRO THROUGH 14Z. OF
NOTE...MECKLENBURG AND LUNENBURG COUNTIES HAVE BEEN REMOVED FROM
THE ADVISORY AS CURRENT OBSERVATIONAL DATA AND MODEL DATA DOES NOT
SUPPORT THE POTENTIAL FOR EVEN MINOR ICING. POINTS FARTHER
EAST...SUCH AS THE NORTHERN NECK AND INTERIOR LOWER MD EASTERN
SHORE COULD EXPERIENCE SOME IP AT THE ONSET. HOWEVER...THERE IS
LITTLE SUPPORT FOR ICING IN THESE LOCATIONS. ANY LINGERING FZRA
THIS MORNING SHOULD TRANSITION TO RA AFTER 9 AM THIS MORNING.
WARM/MOIST ADVECTION CONTINUES TODAY. THE SHORTWAVE TROUGH
RESPONSIBLE FOR THE MORNING PRECIP LIFTS TO THE NE THIS MORNING.
HOWEVER...ANOTHER MID-LEVEL WAVE LIFTS ACROSS THE REGION IN SSW
FLOW ALOFT THIS AFTERNOON. THIS WILL BRING ANOTHER ROUND OF RA TO
PRIMARILY CENTRAL PORTIONS OF THE AREA LATER THIS AFTERNOON.
HIGH TEMPERATURES WILL VARY FROM AROUND 40 NW TODAY WITH A CAD
WEDGE IN PLACE...TO NEAR 60 SE AS THE COASTAL FRONT MOVES INLAND.
WEAK FLOW AND ABUNDANT MOISTURE BELOW 700MB WILL RESULT IN
OVERCAST CONDITIONS THROUGHOUT TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
TEMPERATURES SHOULD FALL VERY LITTLE TONIGHT AS THE SURFACE WARM
FRONT LIFTS THROUGH THE AREA...RESULTING IN WIDESPREAD STRATUS.
THE TROUGH PRESENTLY TRAVERSING THE INTERMOUNTAIN WEST THIS AFTN
WILL PUSH ACROSS THE ROCKIES THROUGH TONIGHT...EVENTUALLY
AMPLIFYING ACROSS THE CENTRAL CONUS ON FRI. SUBSEQUENT INCREASINGLY
ZONAL FLOW OVER THE WESTERN US EVENTUALLY WILL EJECT THE TROUGH
AXIS EAST ACROSS THE APPALACHIANS BY SAT/SAT EVENING. PLENTY OF
SPREAD EXISTS AMONGST GEFS/SREF ENSEMBLE GUIDANCE AS WELL AS
THE DETERMINISTIC MODELS WITH RESPECT TO TIMING. MODELS APPEAR IN
BETTER AGREEMENT WITH QUICKLY SHUNTING THE WARM FRONT NORTHWARD
SAT MORNING. THERE IS A HIGH CONFIDENCE OF MEASURABLE RAIN IN THE
SAT/SAT EVENING TIME FRAME. DEEP MOISTURE THROUGH 300MB COMBINED
WITH STRONG LIFT SHOULD PRODUCE MODERATE TO OCCASIONALLY HEAVY
RAINFALL. HOWEVER...QPF SHOULD LARGELY BE 0.75-1.00IN DUE TO THE
QUICK MOTION OF THE SYSTEM. TEMPERATURES SHOULD BE VERY MILD AS
THE AFOREMENTIONED SURFACE WARM FRONT LIFTS N OF THE LOCAL AREA
AND 850MB TEMPERATURE SURGE TO 10-12C. HIGHS HAVE BEEN NUDGED
UPWARD SLIGHTLY ONCE AGAIN INTO THE MID 60S FAR NW...65-70 FOR
CENTRAL AND EASTERN PORTIONS OF THE AREA. SREF PROBS CONTINUE TO
INDICATE A 90% CHANCE OF 2M DEWPOINTS EXCEEDING 60F ACROSS
S-CENTRAL/SE VA AND NE NC...AND 09/21Z NAM INDICATES STRONG
UPRIGHT FRONTOGENESIS FROM THE SURFACE TO ~750MB (09/00Z ECMWF
INDICATES THIS TO A LESSER EXTENT). THIS IS CONSIDERED A LOW PROB
AT THIS TIME...BUT THERE IS A POTENTIAL FOR A FORCED LINE OF
CONVECTION (RARE BUT NOT UNPRECEDENTED FOR JAN)...GIVEN STRONG
SYNOPTIC FLOW (60-65KT 850-700MB LAYER AVG) COMBINED WITH THE
AFOREMENTIONED ABUNDANT MOISTURE AND MESOSCALE FORCING.
A TRANSITION DAY ON SUNDAY AS UPPER TROUGH PIVOTS OFFSHORE AND
QUASI-ZONAL FLOW BRING A CLEARING AND STILL-MILD DAY. HIGHS
GENERALLY IN THE 50S TO NEAR 60.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
STAYING CLOSE TO THE 12Z ECMWF FOR THE EXTENDED PERIOD. HI PRES WILL
SLIDE OFF THE CST AND OUT TO SEA SUN NGT THRU MON...PROVIDING MSTLY
CLEAR/PARTLY TO MOSTLY SUNNY CONDITIONS ACRS THE AREA. LATE MON NGT
THRU TUE...THE LATEST ECMWF BRINGS A SRN STREAM LO AND A COLD FRONT
TWD/AND ACRS THE AREA LATE MON NGT THRU TUE. AT THIS TIME...HAVE
SLGT CHC (20) POPS THEN CHC (30) POPS OVR THE REGION. THE FRONT
PUSHES OUT TO SEA TUE EVENG...BUT A SECONDARY BOUNDARY MAY CROSS THE
AREA ON WED. HAVE KEPT A DRY FCST FOR WED AT THIS TIME. DRIER AND
COOLER WNW FLO FILTERS IN FOR WED NGT THRU THU...AS HI PRES BLDS
INTO AND OVR THE REGION. MIN TEMPS WILL RANGE THRU THE 30S MON
MORNG...IN THE UPR 30S TO MID 40S TUE MORNG...IN THE 30S WED
MORNG...AND IN THE MID 20S TO LWR 30S THU MORNG. MAX TEMPS WILL
RANGE FM THE MID 50S TO LWR 60S MON...IN THE 50S TUE...IN THE MID
40S TO LWR 50S WED...AND IN THE 40S THU.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
A LIGHT EASTERLY FLOW WILL GRADUALLY INCREASE MOISTURE INTO THE AREA
OVERNIGHT. CLOUDS BEGIN TO DEVELOP BELOW 10K FT AFTER MIDNIGHT AS AN
INVERTED TROUGH/COASTAL FRONT DEVELOP TOWARD MORNING PROVIDING SOME
LIFT. THE LOCATION OF THIS FRONT WILL AFFECT THE WIND DIRECTION (SE
WINDS TO THE EAST OF THE FRONT) AND IMPACT THE CEILING HEIGHT ON
FRIDAY. AS THIS FRONT DEVELOPS MID TO LATE MORNING...IT SHOULD SET
UP WEST OF ALL THE TAF SITES EXCEPT RIC THROUGH MIDDAY. THUS HAVE
IFR LATE MORNING AT RIC BUT MVFR OR BETTER AT THE REST. EVENTUALLY
THE FRONT IS EXPECTED TO MOVE SLIGHTLY TO THE WEST OF RIC...
IMPROVING CONDS THERE TO MVFR. USED NAM AND GFS SOUNDINGS AND
POP GRIDS TO DETERMINE TIMING OF THE PCPN. HAVE IT BEGIN MID TO LATE
MORNING BUT STAYING NORTH OF ECG. RAIN DIMINISHES AFT 18Z.
THE POTENTIAL FOR FZRA OR PL (BRIEFLY AROUND 12Z FRIDAY) IS MAINLY
WEST OF RIC AND ANY THAT OCCURS SHOULD HAVE LITTLE TO NO IMPACT.
OUTLOOK...A MORE ORGANIZED FRONTAL SYSTEM APPROACHES THE REGION ON
SATURDAY...WITH PERIODS OF RAIN AND WIDESPREAD MVFR/OCNL IFR
CONDITIONS AND GUSTY WINDS. LOOK FOR DRY AND VFR SUNDAY AND MONDAY
THEN DETERIORATING CONDS ONCE AGAIN AROUND TUESDAY.
&&
.MARINE...
DO NOT HAVE ANY HEADLINES IN THE SHORT TERM TNGT THRU FRI NIGHT. HI
PRES WILL MOVE OFF THE NEW ENGLAND CST TNGT...AS A TROF OF LO PRES
DEVELOPS ALNG THE CAROLINA CST. NE WINDS 10 KT OR LESS THIS
EVENG...WILL BECOME ESE FOR TNGT THRU FRI. SE WINDS WILL THEN
INCREASE TO NEAR 15 TO 20 KT LATE FRI NGT...THEN BECOME S AND
INCREASE TO 15 TO 25 KT AND GUSTY FOR SAT...AS A WARM FRONT LIFTS
NWRD THRU THE AREA...FOLLOWED BY THE APPROACH OF A COLD FRONT.
SCA FLAGS WILL BE LIKELY FOR STRONG SOUTHERLY WINDS SAT AFTN/SAT
NGT...WITH SEAS BUILDING TO 5-9 FT. WINDS BECOME WNW AND REMAIN
RATHER STRONG BEHIND THE FRONT SAT NGT INTO SUN AFTN...THEN SETTLE
DOWN AND BECOME SW SUN NGT...AS HI PRES BLDS IN THEN MOVES OFFSHR.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...FREEZING RAIN ADVISORY UNTIL 9 AM EST THIS MORNING FOR VAZ048-
049-060>064-067>069.
MARINE...NONE.
&&
$$
SYNOPSIS...MAM
NEAR TERM...AJZ
SHORT TERM...AJZ/MAM
LONG TERM...TMG
AVIATION...LSA
MARINE...TMG
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1146 PM EST THU JAN 9 2014
.AVIATION...
//DISCUSSION...
SNOW CONTINUES TO LIFT THROUGH SOUTHEAST MICHIGAN OVERNIGHT AHEAD OF
A WARM FRONT LIFTING NORTH. IT APPEARS THE SNOW WILL MISS MBS FOR
THE MOST PART. ONCE THE SNOW LIFTS OUT OF THE AREA LIGHT SNOW AND
FLURRIES WILL REMAIN BEFORE MID LEVEL MOISTURE GETS SCOURED OUT
EARLY FRIDAY MORNING...BRINGING FREEZING DRIZZLE TO THE TAF SITES.
THE POTENTIAL FOR FREEZING DRIZZLE IS HIGHER TOWARD SUNRISE IN THE
DTW TO PTK CORRIDOR CLOSER TO THE SURFACE WARM FRONT BUT IT IS
POSSIBLE AS FAR NORTH AS MBS JUST WITH LOWER CONFIDENCE THERE.
CIGS/VSBYS ARE DIFFICULT TO GET A HANDLE ON AS THEY VARY FROM VFR TO
IFR. OVERALL EXPECT CONDITIONS TO SETTLE INTO THE MVFR
CATEGOR...EVENTUALLY FALLING TO IFR BEHIND THE WARM FRONT FRIDAY
MORNING AND REMAINING THERE AS DRIZZLE AND RAIN IMPACT THE TAF SITES
THROUGH FRIDAY EVENING.
FOR DTW...A FEW HOURS OF FREEZING DRIZZLE IS EXPECTED TO BEGIN
TOWARD SUNRISE AND LAST THROUGH LATE MORNING WHEN TEMPERATURE IS ON
SCHEDULE TO RISE ABOVE FREEZING.
//DTW THRESHOLD THREATS...
* HIGH CONFIDENCE IN CEILINGS BELOW 5000 FEET THROUGH THE TAF PERIOD.
* HIGH CONFIDENCE IN SNOW AS PRECIPITATION TYPE OVERNIGHT.
* MEDIUM CONFIDENCE IN FREEZING DRIZZLE DEVELOPMENT TOWARD SUNRISE
FRIDAY.
&&
.PREV DISCUSSION...ISSUED 359 PM EST THU JAN 9 2014/
SHORT TERM... AFTERNOON AND TONIGHT
AFTERNOON RADAR COMPOSITE AND SURFACE OBSERVATIONS INDICATE THE SNOW
SHOWER PATTERN COMING TOGETHER WITH SOME GUSTO OVER NORTHERN INDIANA
AND WESTERN OHIO. THE MID LEVEL SHORT WAVE SHOWN ON WATER VAPOR
IMAGERY LOOKS QUITE DYNAMIC AND IS HELPING SHAPE UP THE WARM FRONT
OVER THE OHIO VALLEY AT THE SURFACE AND ENHANCING ISENTROPIC LIFT TO
THE NORTH OF THE FRONT INTO LOWER MICHIGAN. MODEL CROSS SECTIONS
INDICATE THE SHORT WAVE INDUCED DCVA AND ISENTROPIC LIFT OCCURRING IN
A LOW STABILITY ENVIRONMENT AND WITH A GENEROUS AMOUNT OF MOISTURE
RESULTING IN THE STRONG VERTICAL MOTION RESPONSE. THE TEXTURE OF THE
RADAR COMPOSITE EVEN SUGGESTS WEAK CONVECTIVE INSTABILITY ABOVE THE
FRONTAL SURFACE, ROUGHLY IN THE 700-500 MB LAYER JUDGING FROM MODEL
THETA-E PROFILES. THE LATEST RUNS OF THE NAM AND RAP HAVE A
REASONABLE HANDLE ON THE EVOLUTION OF THE PATTERN AS THE WAVE SLIDES
JUST SOUTH OF THE OHIO BORDER. THEY SHOW THE MOST INTENSE VERTICAL
MOTION OCCURRING ROUGHLY ALONG AND SOUTH OF A LINE FROM HOWELL TO
PORT HURON WITH A PEAK INTENSITY OCCURRING AROUND MID EVENING. THIS
WILL CONSIST OF A GOOD COMBINATION OF LOW LEVEL ISENTROPIC LIFT AND
MID LEVEL SHEARING DEFORMATION FUELED BY SPECIFIC HUMIDITY NEAR 3
G/KG. EXPECT THE RESULT TO BE WIDESPREAD LIGHT SNOW WITH IMBEDDED
HEAVIER BURSTS ADDING UP TO ABOUT AN INCH OF ACCUMULATION AS FAR
NORTH AS INTERSTATE 69. BOTH COVERAGE AND INTENSITY WILL BE LESS
TOWARD THE TRI CITIES AND NORTHERN THUMB AND THEN WILL DIMINISH OVER
THE SOUTH AFTER MIDNIGHT.
STRONG MID LEVEL SUBSIDENCE TRAILING THE WAVE WILL THEN SET THE
STAGE FOR FREEZING DRIZZLE POTENTIAL TOWARD SUNRISE. MODEL
SOUNDINGS INDICATE SUBSIDENCE INDUCED MID LEVEL DRYING TAKING
PLACE TOWARD 12Z WHICH WILL ELIMINATE ICE CRYSTAL NUCLEATION. THAT
WILL LEAVE A FAVORABLE PROFILE FOR FREEZING DRIZZLE FORCED BY WIND
SHEAR AND INSTABILITY AT THE TOP OF THE BOUNDARY LAYER/FRONTAL
SLOPE. WHILE THE LARGE SCALE ENVIRONMENT IS SUPPORTIVE AND GROUND
SURFACES ARE VERY COLD, UNCERTAINTY ON COVERAGE, DURATION, AND
INTENSITY IS HIGH ENOUGH TO HOLD OFF ON HEADLINE ISSUANCE AT THIS
POINT. OTHERWISE, THE STRONG NONDIURNAL TEMPERATURE TREND WILL
HAVE MINS OCCURRING DURING EARLY EVENING FOLLOWED BY RISING TEMPS
OVERNIGHT, BUT ONLY INTO THE LOWER AND MID 20S BY SUNRISE FRIDAY.
LONG TERM...FRIDAY THROUGH SATURDAY NIGHT
MAIN CONCERNS OVER THIS TIME PERIOD IS THE START TIME AND TYPE OF
PRECIPITATION...ESPECIALLY FRIDAY AFTERNOON INTO EVENING BEFORE
WARMER AIR WORKS UP INTO THE AREA. WEAK RIDGING AHEAD OF THE MAIN
UPPER LEVEL TROUGH MOVING ACROSS THE AREA WILL ALLOW FOR A SLIGHT
DOWNTURN IN THE PRECIP FRIDAY MORNING BEFORE MORE SUBSTANTIAL
PRECIPITATION WORKS IN WITH THE NEXT LOW PRESSURE SYSTEM FRIDAY INTO
SATURDAY. 120+ KNOT JET GETS GOING WITH THE LEFT ENTRANCE REGION
MOVING OVER THE AREA. THIS JET THEN STRENGTHENS AS IT MOVES TO THE
EAST OF THE AREA SATURDAY AFTERNOON. MODELS HAVE FINALLY COME INTO
BETTER AGREEMENT ON THE TIMING AND DURATION OF THIS SYSTEM. AS THE
LOW TRACKS NORTHEAST ACROSS WISCONSIN AND UPPER MICHIGAN...THIS
WILL PULL A WARM FRONT UP THROUGH THE AREA FRIDAY BRINGING
MOISTURE AND WARMER AIR TO SE MI. AS WITH THE CASE OF
TRANSITIONING PRECIP TYPE THE BIGGEST CAVEAT WILL BE HOW LONG
FREEZING DRIZZLE/RAIN LINGERS BEFORE THE WARMER AIR WORKS IN
CHANGING PRECIP TO ALL RAIN. THIS TRANSITION DOES APPEAR TO BE OF
SHORTER DURATION AS THE LOW LEVEL JET GETS GOING AND PUSHES IN THE
WARMER AIR. SOUNDING PROFILES SHOW SATURATED LOW LEVELS WITH DRIER
AIR IN THE MID LEVELS SUPPORTIVE OF DRIZZLE WITH THE ONSET OF
PRECIP BEFORE MID LEVELS SATURATE. BETTER FORCING AND PRECIP
CHANCES HOLD OFF UNTIL SATURDAY EVENING AS THE COLD FRONT
APPROACHES. POPS INCREASE FROM 00Z TO 12Z ON SATURDAY WHICH
COINCIDES WITH FAVORED ISENTROPIC ASCENT AHEAD OF THE COLD FRONT.
PWAT VALUES REMAINED NEAR 3/4 OF AN INCH...WHICH IS GOOD FOR THIS
TIME OF YEAR. WITH THE 12Z MODEL RUNS PUSHING THE COLD FRONT
THROUGH A LITTLE FASTER...PRECIP AMOUNTS WERE LOWERED A TINY BIT.
THE COLD FRONT IS EXPECTED TO EXIT THE AREA EARLY SATURDAY
MORNING...BRINGING AN END TO THE HEAVIER PRECIP. SHOWERS WILL
LINGER BEHIND THE FRONT BEFORE RIDGING MOVES BACK IN AND
TEMPERATURES DROP BACK BELOW FREEZING. TEMPERATURES WERE DROPPED A
LITTLE BIT TO TAKE INTO ACCOUNT THE SNOW COVER AND THE FASTER
TIMING OF THE COLD FRONT THROUGH THE AREA SATURDAY EVENING. WAA
WORKS IN AS STRONG SOUTHERLY FLOW INCREASES BEHIND THE WARM FRONT
LATE FRIDAY BEFORE CAA TAKES OVER WITH THE EXITING COLD FRONT
SATURDAY AFTERNOON. TEMPERATURES REMAIN ABOVE FREEZING AND STEADY
FRIDAY INTO FRIDAY NIGHT BEFORE DROPPING BACK DOWN ONCE AGAIN.
SURFACE RIDGING OVER THE GREAT LAKES REGION WILL KEEP SUNDAY MOSTLY
DRY. SOUTHWESTERLY WINDS PICK UP ON SUNDAY WITH GUSTS UP TO 25 MPH
DURING THE DAY. THERE IS SOME UNCERTAINTY AMONGST MODELS REGARDING
PRECIPITATION CHANCES ON MONDAY. THEREFORE...HAVE ONLY KEPT A SLIGHT
CHANCE IN THE FORECAST. HOWEVER...THERE LOOKS TO BE BETTER AGREEMENT
THAT TUESDAY COULD BRING SOME PRECIP TO THE REGION. 850 MB TEMPS
LOOK TO BE COLD ENOUGH TO SUPPORT ALL SNOW FOR PRECIP ON TUESDAY.
HIGH TEMPERATURES WILL START OFF ABOVE NORMAL /FORECASTED HIGHS IN
THE UPPER 30S/ ON MONDAY AND SLOWLY DECREASE THROUGHOUT THE
REMAINDER OF THE WEEK DROPPING TO THE MID 20S BY THURSDAY. LOWS WILL
ALSO START OFF ABOVE NORMAL /LOW 30S/ FOR MONDAY NIGHT AND STEADILY
DROP INTO THE LOW TEENS /BELOW NORMAL/ BY THURSDAY NIGHT.
MARINE...
SOUTHERLY FLOW WILL CONTINUE TO INCREASE THROUGH TONIGHT AS HIGH
PRESSURE SLIDES TOWARDS THE EAST COAST. LOW PRESSURE APPROACHING
FROM THE PLAINS WILL THEN MAINTAIN SOUTHERLY FLOW THROUGH
FRIDAY...WITH SPEEDS INCREASING FRIDAY NIGHT AS A WARM FRONT LIFTS
UP THROUGH THE GREAT LAKES. SOUTH TO SOUTHEAST WINDS WILL BECOME
GUSTY OVER LAKE HURON FRIDAY NIGHT AS THE LOW TRACKS UP THROUGH LAKE
MICHIGAN. SUSTAINED SPEEDS LOOK TO RANGE BETWEEN 20 AND 28 KNOTS
OVER MUCH OF THE LAKE...HOWEVER WARMER AIR FLOWING OVER THE LAKE
SURFACE WILL KEEP STABILITY HIGH AND LIMIT WIND GUSTS TO BELOW GALE
FORCE. COLDER AIR WILL POUR INTO THE REGION ON THE BACKSIDE OF THE
SYSTEM ON SATURDAY. THE ARRIVAL OF THE COLDER AIR COMBINED WITH A
TIGHT SURFACE PRESSURE GRADIENT AND STRONG WINDS ABOVE THE LAKE
SURFACE MAY ALLOW GALE FORCE WINDS TO DEVELOP OVER THE CENTRAL
PORTION OF LAKE HURON. A GALE WATCH IS NOW IN EFFECT OVER THE
CENTRAL PORTION OF THE LAKE ON SATURDAY...INCLUDING SAGINAW BAY AND
THE NEARSHORE WATERS FROM PORT AUSTIN TO HARBOR BEACH. WIND SPEEDS
WILL DECREASE SATURDAY NIGHT AND SUNDAY AS HIGH PRESSURE BUILDS
BRIEFLY BACK OVER THE AREA.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...
GALE WATCH...LHZ362-LHZ363-LHZ421-LHZ422-LHZ441-LHZ462...FROM 7 AM
SATURDAY TO 7 PM SATURDAY.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....KURIMSKI
SHORT TERM...BT
LONG TERM....SS/RK/HLO
MARINE.......SS/HLO
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
333 PM CST FRI JAN 10 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 255 PM CST FRI JAN 10 2014
BEGINNING TO LOOK LIKE FZDZ MIGHT BE ABOUT ALL THE MPX AREA SEES
FROM THE UPPER WAVES WORKING ACROSS THE CENTRAL CONUS NOW. THE
PROBLEM CONTINUES TO BE A DELAYED PHASING OF A NORTHERN STREAM
WAVE CURRENTLY HEADING FOR NW MN AND A SRN STREAM WAVE THAT IS
MOVING UP OUT OF IA TOWARD WI. THESE TWO SYSTEMS DO NOT REALLY
LOOK TO BECOME ONE UNTIL SAT MORNING OVER MICH. THE RUB THERE IS
THAT THE SRN STREAM WAVE IS THE ONE WITH ALL OF THE MOISTURE AND
THEREFORE PRECIPITATION AND WITH THESE SYSTEMS NOT PHASING UNTIL
SATURDAY...WE ARE SEEING THE PRECIPITATION MOVING THROUGH FASTER
AND FARTHER EAST TODAY/TONIGHT. RUNS OF THE HOPWRF TODAY HAVE BEEN
PROGRESSIVELY INCHING A DEFORMATION BAND EAST WITH TIME AND WITH
THE 15Z RUN ALL 4 MEMBERS ARE NOW SHOWING A BAND OF ENHANCED
PRECIP FALLING FROM ABOUT DECORAH...IA UP TOWARD WAUSAU...EAST OF
THE MPX CWA. ON RADAR...THERE IS A CLUSTER OF HIGHER RETURNS THAT
MATCHES UP WELL WITH THESE PRECIPITATION SWATHS AND WITH THE HRRR
PICKING UP ON THIS SCENARIO NOW AS WELL...CONFIDENCE IS BEGINNING
TO INCREASE THAT THIS SYSTEM WILL BE A DUD IN THE SNOWFALL
DEPARTMENT FOR THE MPX AREA.
WITH ALL OF THAT SAID...STILL ANTICIPATE SOME LIGHT SNOW TO DEVELOP
MAINLY EAST OF THE I-35 CORRIDOR AS THE SFC TROUGH THAT IS STILL
HANGING OUT ALONG THE MN/DAKOTAS BORDER SLIDES EAST THIS
EVENING...MEETING UP WITH THE DEEPER MOISTURE STREAMING NORTH INTO
WI. HAVE FOLLOWED THE IDEA OF THE HRRR AND OTHER HI-RES MODELS WHICH
SHOW JUST LIGHT QPF/SIMULATED REFLECTIVITY DEVELOPING OVER ERN MN
WITHIN THE NEXT COUPLE OF HOURS BEFORE SLOWLY SLIDING EAST. SAID SFC
TROUGH WILL CLEAR THE MPX AREA AROUND 9Z...WITH ANY SNOW LIKELY
CUTTING OFF AFTER THAT. BASICALLY...THERE MIGHT BE ONE OR TWO LUCKY
FOLKS OUT THERE THAT PICK UP A HALF INCH OF SNOW OUT OF
THIS...OTHERWISE IT IS JUST A SEA OF LOW CLOUDS AND HAZE UNTIL THE
SFC TROUGH CLEARS AND WINDS BECOME WNW.
AS FOR TONIGHT...FOLLOWED THE IDEA OF THE RAP AND NAM OF SKIES
SCATTERING OUT AT LEAST FOR A LITTLE WHILE AS BOUNDARY LAYER WINDS
BECOME MORE WRLY...MUCH LIKE WHAT HAS BEEN SEEN TODAY ACROSS THE
DAKOTAS. THINKING WE WOULD SEE SOME CLEARING...DID FOLLOW THE IDEA
MOST GUIDANCE SHOWS OF KNOCKING LOWS BACK INTO THE LOWER TEENS FOR
MUCH OF THE AREA WEST OF TWIN CITIES.
NOT MUCH TO SAY ABOUT SATURDAY...OTHER CLOUDS CURRENTLY MOVING INTO
NRN NODAK SWEEP THROUGH HERE DURING THE MORNING/EARLY AFTERNOON WITH
HIGHS STILL LOOKING TO NESTLE UP INTO THE 5-10 DEGREES ABOVE NORMAL
RANGE. SO MADE ONLY MINOR CHANGES TO EXISTING FORECAST...MAINLY
JUST BLENDING IN LATEST BIAS CORRECTED MODEL DATA.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 255 PM CST FRI JAN 10 2014
LONGER TERM TRENDS CONTINUE TO INDICATE RATHER PROGRESSIVE UPPER
LEVEL FLOW PATTERN OVER THE AREA DURING THE PERIOD. COOLING TREND
APPEARS TO TAKE HOLD BY LATE IN THE PERIOD AS ANOTHER AREA OF COLD
AIR DIVES SOUTHEAST ALONG THE AMPLIFYING HUDSON BAY VORTEX.
A LIGHT MIX OF PRECIPITATION MAY STILL OCCUR UNDER STRONG WAA
PATTERN UNDER STRONG 130KT H25 JET SUNDAY INTO SUNDAY NIGHT.
WARMING ALOFT INDICATES FAVORABLE THICKNESS FOR POSSIBLE LIGHT
ZR-/ZL- INTO THE DAY AS SURFACE TEMPERATURES WARM THROUGH THE LOWER
30S DURING TH DAY. WHATEVER IS LEFT INTO THE EVENING/SUNDAY
OVERNIGHT WILL CHANGE OVER TO SNOW...BUT ONLY LIGHT QPF AMOUNTS
ARE INDICATED.
DETERMINISTIC EC AND GFS CONTINUE TO SHOW ANOTHER WEAK CLIPPER
TYPE SYSTEM DIVING SOUTHEAST ALONG WEAK SURFACE BOUNDARY...AFFECTING
MAINLY SOUTHERN CWA DURING THE MONDAY INTO MONDAY NIGHT PERIOD.
TIMING IS IN QUESTION...WITH THE 12Z GFS A BIT FASTER THAN THE 12Z
EC. WONT GET TOO CUTE ON TIMING OF THIS SYSTEM NOW...BUT WE COULD
SEE SOME LIGHT SNOW ACCUMULATION WITH THIS AS IT PASSES THROUGH.
BRIEF SHOT OF COLDER AIR ARRIVES FOR TUESDAY/TUESDAY NIGHT
AHEAD OF NEXT SURGE OF PACIFIC AIR FOR WEDNESDAY. MODELS INDICATE
THE NEXT MAIN SURGE OF ARCTIC AIR ARRIVES THURSDAY AND WILL LINGER
THROUGH THE END OF THE PERIOD AS THE EASTERN CONUS TROUGH DIGS SOUTHEAST.
AT THE MOMENT...IT DOESNT APPEAR TO BE AS COLD AS THE LAST
WILL HAVE TO MONITOR DEVELOPMENT OF THE TROUGH INTO NEXT WEEK.
COULD SEE SOME LIGHT SNOW/SNOW SHOWERS WITH THIS AS IT DIVES SOUTHEAST
AND THE COLD AIR ARRIVES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1201 PM CST FRI JAN 10 2014
SFC TROUGH CURRENTLY APPROACHING THE WRN MN BORDER WILL BE KEY
PLAYER THIS TAF PERIOD...AS WNW WINDS BEHIND IT ARE ALSO BRINGING
IN MO CLR SKIES AND P6SM VIS. IFR CIGS/VIS WILL REMAIN FIRMLY IN
PLACE EAST OF THIS TROUGH...WITH LITTLE IN THE WAY OF CHANGES FROM
CURRENT CONDITIONS EXPECTED UNTIL IT MOVES THROUGH. HAVE IGNORED
THE GFSLAMP SKY FORECAST FOR BEHIND THIS BOUNDARY...AS IT IS HARD
TO BELIEVE THE LOW CIGS WILL CONTINUE TO BE A PROBLEM ONCE WNW
WINDS SET IN BASED ON THE LACK OF CLOUDS CURRENTLY ACROSS THE
DAKOTAS. TIMED CIG IMPROVEMENTS THROUGH BASED ON A RAP/NAM/GFS
TIMING. FOR PRECIP...KMPX RADAR RETURNS THE LAST HOUR HAVE BEEN
BLOSSOMING...INDICATIVE OF THE LIGHT FZDZ CURRENTLY BEING REPORTED
AT MSP. EXPECT MOST OF THE FZDZ TO BE DONE BY 21Z...BUT IT IS NOT
OUT OF THE QUESTION THAT WE MAY SEE NOTHING BUT FZDZ UNTIL THE SFC
TROUGH MOVES THROUGH. FOR SNOW...CONFINED IT MAINLY TO EAU...WITH
TIMING BASED ON THE HRRR. WITH THE NAM/RAP/HOPWRF SHOWING VERY
LITTLE QPF BACK THIS FAR WEST...CONFIDENCE IN THE SNOWFALL
FORECAST REMAINS LOW. AT BEST...AN INCH OF SNOW WILL BE POSSIBLE
AT EAU.
KMSP...HIGH CONFIDENCE IN CIG/VIS FORECAST THROUGH 03Z. AFTER
THAT...CONFIDENCE DECREASES SOME WITH WHEN VFR CIGS RETURN...BUT
LOOKS LIKELY TO HAPPEN IN THE 4-8Z WINDOW. MAY SEE SOME LIGHT SNOW
IN THE 22-02Z WINDOW AS WELL... BUT DO NOT EXPECT VIS
RESTRICTIONS TO BE ANY WORSE THAN WHAT WE ARE SEEING WITH CURRENT
BR. FOR LATE SATURDAY MORNING INTO THE AFTERNOON...WILL HAVE TO
WATCH HOW FAR SOUTH MVFR CIGS IN SE SASKATCHEWAN BUILD AS THEY MOVE
SE PER THE NAM AND GFS. MAY SEE A FEW HOURS WERE CIGS DIP BACK
DOWN TO AROUND 020 AS THAT BIT OF MOISTURE MOVES THROUGH.
/OUTLOOK FOR KMSP/
SUN...VFR. WINDS SW 10-15 KTS.
MON...VFR. CHC MVFR/-SN OVERNIGHT. WINDS W-SW 5-10 KTS.
TUE...VFR. CHC MVFR CIGS. WINDS NW 15G25 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...DWE
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1123 AM CST FRI JAN 10 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 338 AM CST FRI JAN 10 2014
THE RAP HAS ANALYZED A H500 MB SHORT WAVE ACROSS ERN WYOMING THIS
MORNING. THE PV15 ANOMALY EXTENDS FROM KCYS SOUTH THROUGH KDEN.
IF THE RAP AND THE OTHER MODELS ARE CORRECT THEN SCATTERED SNOW
SHOWERS SHOULD DEVELOP ACROSS NW NEB IN A FEW HOURS AND MOVE
SOUTHEAST THROUGH SWRN AND SCNTL NEB. THE ONGOING RADAR RETURNS
ACROSS NERN COLO ARE RAIN AND THE SNOW SHOWERS SHOULD DEVELOP
ONCE THE THERMAL RIDGE ACROSS SWRN NEB MOVES EAST LATER THIS
MORNING.
OTHERWISE...THE ARCTIC DRAPE WILL MOVE EAST OF THE FCST AREA IN A
FEW HOURS AHEAD THE SHORT WAVE AND ALL OF THIS WEATHER SHOULD
EXIT THE FCST AREA TO THE EAST BY 21Z PROVIDING FOR A PARTLY
SUNNY AFTERNOON WITH HIGHS IN THE UPPER 30S TO MID 40S.
FOR TONIGHT...A WEAK COLD FRONT WILL BE PRESSING INTO NRN
NEBRASKA TOWARD MORNING. THERE IS VERY LITTLE THERMAL RIDGING
AHEAD OF THE FRONT AND H850 WINDS INCREASE FROM 25 TO 35 KT
FRIDAY EVENING TO 40 TO 50 KT BY SATURDAY MORNING. ALL OF THIS
SUGGESTS...GIVEN THE GENERALLY CLEAR SKIES TONIGHT...LOWS IN THE
20S MOST AREAS WITH TEENS IN THE PLATTE VALLEY AND CUSTER COUNTY.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 338 AM CST FRI JAN 10 2014
LITTLE CHANGE TO THE OVERALL PATTERN WITH A RIDGE IN THE WEST AND
A TROUGH IN THE EAST...AND NORTHWEST FLOW ACROSS THE HIGH PLAINS.
SEVERAL WEAK TROUGHS/CLIPPERS WILL PUSH ACROSS THE PLAINS...WITH
A SLIGHT WARM UP AHEAD OF THE SYSTEM...AND A SLIGHT COOL DOWN
WITH AN INCREASE OF CLOUDS WITH EACH TROUGH.
WARM AIR ARRIVES FOR SATURDAY AHEAD OF THE NEXT TROUGH HIGHS
NEARING THE MID 50S FOR THE SW AS 850 MB TEMPS PUSH TO AROUND 10
C. COOLER OVER N CENTRAL...MID 40S WITH 850 MB TEMPS CLOSER TO
ZERO. SATURDAY NIGHT INTO SUNDAY THE TROUGH WILL CROSS THE CWA.
MIXING ALONG AHEAD OF THE TROUGH WILL PUSH TEMPS BACK TO AROUND
50...WITH THE NW HOLDING CLOSER TO 40. THERE IS A CHANCE FOR SOME
VERY LIGHT PRECIP /FLURRIES OR SPRINKLES/ ALTHOUGH LOW
CONFIDENCE. MODELS HAVE SEVERAL MARGINAL POSITIVES TO LIGHT
PRECIP...HOWEVER THEY ARE NOT OVERLAPPING. THE NW ZONES HAS THE
STEEPEST LAPSE RATES HOWEVER THE RIGHT ENTRANCE TO A JET STREAK
FAVORS THE SW. LL MOISTURE IS LIMITED AND MODELS VARY WITH
POCKETS OF LOWER CONDENSATION DEFICITS...LESS THAN 20 MB. BY
SUNDAY EVENING TROUGH AXIS IS EAST AND ANY LIGHT PRECIP WILL HAVE
ENDED.
MONDAY THE RIDGE RETURNS LATE IN THE DAY...AND HIGHS SHOULD
REBOUND LATE TO AROUND 50 SW TO MID 50S N. BY MONDAY NIGHT A WEAK
UPPER LEVEL DISTURBANCE TO RIDE THE NW FLOW. BETTER ENERGY IS
ACROSS THE NORTHERN PLAINS...HOWEVER MAY GET SOME LIGHT SNOW
ACROSS THE NW...WHERE MODELS HAVE A LITTLE UPPER LEVEL SUPPORT
FROM THE LEFT EXIT REGION OF THE NEXT JET STREAK.
THIS WILL WEAK SYSTEM WILL QUICKLY PASS TO THE EAST ON
TUESDAY...ALTHOUGH SOME LINGERING CLOUDS EARLY ON IN THE DAY MAY
LIMIT HEATING AND FOLLOWED SLIGHT COOL DOWN FROM THE DAY
BEFORE...PER GUIDANCE.
AS SYSTEM DIGITS ACROSS THE GREAT LAKES REGION/MID ATLANTIC FOR
WEDNESDAY...RIDGE EXPANDS ACROSS THE WEST. MODELS IN GOOD
AGREEMENT WITH ANOTHER SURGE OF WARMER AIR ACROSS THE HIGH
PLAINS. HIGHS ONCE AGAIN INTO THE MID AND UPPER 50S FOR SW NEB
AND UPPER 40S ELSEWHERE. THIS WARM AIR WILL BE AHEAD OF THE NEXT
CLIPPER WHICH SHOULD ARRIVE WED NIGHT. THIS WILL BRING ANOTHER
COOL DOWN FOR THURSDAY.
ONE COMMON THEME THROUGH THE END OF THE WEEKEND INTO NEXT WEEK
WILL BE BREEZY TO WINDY CONDITIONS. FAST MOVING SYSTEMS ARE
STEERED BY SWIFT WINDS ALOFT AND WITH HIGHS ABOVE SEASONAL
AVERAGES...GOOD MIXING WILL TAP INTO THE STRONGER WINDS. DAY TIME
SFC WINDS OF 15 TO 30 MPH...WITH HIGHER GUSTS...CAN BE EXPECTED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1120 AM CST FRI JAN 10 2014
MAIN CONCERN FOR THE CURRENT TAF PERIOD IS THE POTENTIAL FOR SNOW
SHOWERS ACROSS WESTERN AND NORTH CENTRAL NEBRASKA THROUGH FRIDAY
AFTERNOON...MAINLY IMPACTING THE KLBF TERMINAL WHERE A TEMPO GROUP
HAS BEEN INCLUDED FOR -SHSN AND VISBYS DOWN TO 3SM OR LESS IN THE
18Z TO 21Z TIME FRAME. SKIES WILL BEGIN TO CLEAR UP LATE THIS
AFTERNOON AND EVENING WITH VFR CONDITIONS EXPECTED THROUGH 18Z
SATURDAY. A STRATUS DECK WILL MOVE INTO KVTN TOWARD THE EARLY
MORNING HOURS SATURDAY...HOWEVER AT THIS TIME IT LOOKS TO REMAIN
ABOVE MVFR LEVELS.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...MASEK
AVIATION...MARTIN
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
532 AM CST FRI JAN 10 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 338 AM CST FRI JAN 10 2014
THE RAP HAS ANALYZED A H500 MB SHORT WAVE ACROSS ERN WYOMING THIS
MORNING. THE PV15 ANOMALY EXTENDS FROM KCYS SOUTH THROUGH KDEN.
IF THE RAP AND THE OTHER MODELS ARE CORRECT THEN SCATTERED SNOW
SHOWERS SHOULD DEVELOP ACROSS NW NEB IN A FEW HOURS AND MOVE
SOUTHEAST THROUGH SWRN AND SCNTL NEB. THE ONGOING RADAR RETURNS
ACROSS NERN COLO ARE RAIN AND THE SNOW SHOWERS SHOULD DEVELOP
ONCE THE THERMAL RIDGE ACROSS SWRN NEB MOVES EAST LATER THIS
MORNING.
OTHERWISE...THE ARCTIC DRAPE WILL MOVE EAST OF THE FCST AREA IN A
FEW HOURS AHEAD THE SHORT WAVE AND ALL OF THIS WEATHER SHOULD
EXIT THE FCST AREA TO THE EAST BY 21Z PROVIDING FOR A PARTLY
SUNNY AFTERNOON WITH HIGHS IN THE UPPER 30S TO MID 40S.
FOR TONIGHT...A WEAK COLD FRONT WILL BE PRESSING INTO NRN
NEBRASKA TOWARD MORNING. THERE IS VERY LITTLE THERMAL RIDGING
AHEAD OF THE FRONT AND H850 WINDS INCREASE FROM 25 TO 35 KT
FRIDAY EVENING TO 40 TO 50 KT BY SATURDAY MORNING. ALL OF THIS
SUGGESTS...GIVEN THE GENERALLY CLEAR SKIES TONIGHT...LOWS IN THE
20S MOST AREAS WITH TEENS IN THE PLATTE VALLEY AND CUSTER COUNTY.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 338 AM CST FRI JAN 10 2014
LITTLE CHANGE TO THE OVERALL PATTERN WITH A RIDGE IN THE WEST AND
A TROUGH IN THE EAST...AND NORTHWEST FLOW ACROSS THE HIGH PLAINS.
SEVERAL WEAK TROUGHS/CLIPPERS WILL PUSH ACROSS THE PLAINS...WITH
A SLIGHT WARM UP AHEAD OF THE SYSTEM...AND A SLIGHT COOL DOWN
WITH AN INCREASE OF CLOUDS WITH EACH TROUGH.
WARM AIR ARRIVES FOR SATURDAY AHEAD OF THE NEXT TROUGH HIGHS
NEARING THE MID 50S FOR THE SW AS 850 MB TEMPS PUSH TO AROUND 10
C. COOLER OVER N CENTRAL...MID 40S WITH 850 MB TEMPS CLOSER TO
ZERO. SATURDAY NIGHT INTO SUNDAY THE TROUGH WILL CROSS THE CWA.
MIXING ALONG AHEAD OF THE TROUGH WILL PUSH TEMPS BACK TO AROUND
50...WITH THE NW HOLDING CLOSER TO 40. THERE IS A CHANCE FOR SOME
VERY LIGHT PRECIP /FLURRIES OR SPRINKLES/ ALTHOUGH LOW
CONFIDENCE. MODELS HAVE SEVERAL MARGINAL POSITIVES TO LIGHT
PRECIP...HOWEVER THEY ARE NOT OVERLAPPING. THE NW ZONES HAS THE
STEEPEST LAPSE RATES HOWEVER THE RIGHT ENTRANCE TO A JET STREAK
FAVORS THE SW. LL MOISTURE IS LIMITED AND MODELS VARY WITH
POCKETS OF LOWER CONDENSATION DEFICITS...LESS THAN 20 MB. BY
SUNDAY EVENING TROUGH AXIS IS EAST AND ANY LIGHT PRECIP WILL HAVE
ENDED.
MONDAY THE RIDGE RETURNS LATE IN THE DAY...AND HIGHS SHOULD
REBOUND LATE TO AROUND 50 SW TO MID 50S N. BY MONDAY NIGHT A WEAK
UPPER LEVEL DISTURBANCE TO RIDE THE NW FLOW. BETTER ENERGY IS
ACROSS THE NORTHERN PLAINS...HOWEVER MAY GET SOME LIGHT SNOW
ACROSS THE NW...WHERE MODELS HAVE A LITTLE UPPER LEVEL SUPPORT
FROM THE LEFT EXIT REGION OF THE NEXT JET STREAK.
THIS WILL WEAK SYSTEM WILL QUICKLY PASS TO THE EAST ON
TUESDAY...ALTHOUGH SOME LINGERING CLOUDS EARLY ON IN THE DAY MAY
LIMIT HEATING AND FOLLOWED SLIGHT COOL DOWN FROM THE DAY
BEFORE...PER GUIDANCE.
AS SYSTEM DIGITS ACROSS THE GREAT LAKES REGION/MID ATLANTIC FOR
WEDNESDAY...RIDGE EXPANDS ACROSS THE WEST. MODELS IN GOOD
AGREEMENT WITH ANOTHER SURGE OF WARMER AIR ACROSS THE HIGH
PLAINS. HIGHS ONCE AGAIN INTO THE MID AND UPPER 50S FOR SW NEB
AND UPPER 40S ELSEWHERE. THIS WARM AIR WILL BE AHEAD OF THE NEXT
CLIPPER WHICH SHOULD ARRIVE WED NIGHT. THIS WILL BRING ANOTHER
COOL DOWN FOR THURSDAY.
ONE COMMON THEME THROUGH THE END OF THE WEEKEND INTO NEXT WEEK
WILL BE BREEZY TO WINDY CONDITIONS. FAST MOVING SYSTEMS ARE
STEERED BY SWIFT WINDS ALOFT AND WITH HIGHS ABOVE SEASONAL
AVERAGES...GOOD MIXING WILL TAP INTO THE STRONGER WINDS. DAY TIME
SFC WINDS OF 15 TO 30 MPH...WITH HIGHER GUSTS...CAN BE EXPECTED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 531 AM CST FRI JAN 10 2014
THE LIFR AT KLBF COULD IMPROVE TO VFR AT ANY TIME GIVEN THE
NORTHWEST WINDS AT KOGA.
THE MODELS DEVELOP SCATTERED SNOW SNOWERS THIS MORNING THROUGH
EARLY AFTN. THIS MAY NOT VERIFY AS THE BEST FORCING IS CURRENTLY
MOVING THROUGH NERN COLO/SWRN NEB AND VFR IS WIDESPREAD ACROSS
NWRN NEB AND ERN WY WHERE THE MODELS EXPECT THE SNOW SHOWERS TO
DEVELOP. THERE ARE RADAR RETURNS SHOWING IN THE THESE AREAS
HOWEVER SO COVERAGE COULD BE ISOLATED VS THE SCATTERED COVERAGE
FORECAST.
VFR IS EXPECTED 21Z THROUGH 06Z. THEREAFTER...MVFR CIGS MAY INVADE
THE AREA FROM NORTH TO SOUTH AS ANOTHER COLD FRONT MOVES INTO NRN
NEB.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...MASEK
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
340 AM CST FRI JAN 10 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 338 AM CST FRI JAN 10 2014
THE RAP HAS ANALYZED A H500 MB SHORT WAVE ACROSS ERN WYOMING THIS
MORNING. THE PV15 ANOMALY EXTENDS FROM KCYS SOUTH THROUGH KDEN.
IF THE RAP AND THE OTHER MODELS ARE CORRECT THEN SCATTERED SNOW
SHOWERS SHOULD DEVELOP ACROSS NW NEB IN A FEW HOURS AND MOVE
SOUTHEAST THROUGH SWRN AND SCNTL NEB. THE ONGOING RADAR RETURNS
ACROSS NERN COLO ARE RAIN AND THE SNOW SHOWERS SHOULD DEVELOP
ONCE THE THERMAL RIDGE ACROSS SWRN NEB MOVES EAST LATER THIS
MORNING.
OTHERWISE...THE ARCTIC DRAPE WILL MOVE EAST OF THE FCST AREA IN A
FEW HOURS AHEAD THE SHORT WAVE AND ALL OF THIS WEATHER SHOULD
EXIT THE FCST AREA TO THE EAST BY 21Z PROVIDING FOR A PARTLY
SUNNY AFTERNOON WITH HIGHS IN THE UPPER 30S TO MID 40S.
FOR TONIGHT...A WEAK COLD FRONT WILL BE PRESSING INTO NRN
NEBRASKA TOWARD MORNING. THERE IS VERY LITTLE THERMAL RIDGING
AHEAD OF THE FRONT AND H850 WINDS INCREASE FROM 25 TO 35 KT
FRIDAY EVENING TO 40 TO 50 KT BY SATURDAY MORNING. ALL OF THIS
SUGGESTS...GIVEN THE GENERALLY CLEAR SKIES TONIGHT...LOWS IN THE
20S MOST AREAS WITH TEENS IN THE PLATTE VALLEY AND CUSTER COUNTY.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 338 AM CST FRI JAN 10 2014
LITTLE CHANGE TO THE OVERALL PATTERN WITH A RIDGE IN THE WEST AND
A TROUGH IN THE EAST...AND NORTHWEST FLOW ACROSS THE HIGH PLAINS.
SEVERAL WEAK TROUGHS/CLIPPERS WILL PUSH ACROSS THE PLAINS...WITH
A SLIGHT WARM UP AHEAD OF THE SYSTEM...AND A SLIGHT COOL DOWN
WITH AN INCREASE OF CLOUDS WITH EACH TROUGH.
WARM AIR ARRIVES FOR SATURDAY AHEAD OF THE NEXT TROUGH HIGHS
NEARING THE MID 50S FOR THE SW AS 850 MB TEMPS PUSH TO AROUND 10
C. COOLER OVER N CENTRAL...MID 40S WITH 850 MB TEMPS CLOSER TO
ZERO. SATURDAY NIGHT INTO SUNDAY THE TROUGH WILL CROSS THE CWA.
MIXING ALONG AHEAD OF THE TROUGH WILL PUSH TEMPS BACK TO AROUND
50...WITH THE NW HOLDING CLOSER TO 40. THERE IS A CHANCE FOR SOME
VERY LIGHT PRECIP /FLURRIES OR SPRINKLES/ ALTHOUGH LOW
CONFIDENCE. MODELS HAVE SEVERAL MARGINAL POSITIVES TO LIGHT
PRECIP...HOWEVER THEY ARE NOT OVERLAPPING. THE NW ZONES HAS THE
STEEPEST LAPSE RATES HOWEVER THE RIGHT ENTRANCE TO A JET STREAK
FAVORS THE SW. LL MOISTURE IS LIMITED AND MODELS VARY WITH
POCKETS OF LOWER CONDENSATION DEFICITS...LESS THAN 20 MB. BY
SUNDAY EVENING TROUGH AXIS IS EAST AND ANY LIGHT PRECIP WILL HAVE
ENDED.
MONDAY THE RIDGE RETURNS LATE IN THE DAY...AND HIGHS SHOULD
REBOUND LATE TO AROUND 50 SW TO MID 50S N. BY MONDAY NIGHT A WEAK
UPPER LEVEL DISTURBANCE TO RIDE THE NW FLOW. BETTER ENERGY IS
ACROSS THE NORTHERN PLAINS...HOWEVER MAY GET SOME LIGHT SNOW
ACROSS THE NW...WHERE MODELS HAVE A LITTLE UPPER LEVEL SUPPORT
FROM THE LEFT EXIT REGION OF THE NEXT JET STREAK.
THIS WILL WEAK SYSTEM WILL QUICKLY PASS TO THE EAST ON
TUESDAY...ALTHOUGH SOME LINGERING CLOUDS EARLY ON IN THE DAY MAY
LIMIT HEATING AND FOLLOWED SLIGHT COOL DOWN FROM THE DAY
BEFORE...PER GUIDANCE.
AS SYSTEM DIGITS ACROSS THE GREAT LAKES REGION/MID ATLANTIC FOR
WEDNESDAY...RIDGE EXPANDS ACROSS THE WEST. MODELS IN GOOD
AGREEMENT WITH ANOTHER SURGE OF WARMER AIR ACROSS THE HIGH
PLAINS. HIGHS ONCE AGAIN INTO THE MID AND UPPER 50S FOR SW NEB
AND UPPER 40S ELSEWHERE. THIS WARM AIR WILL BE AHEAD OF THE NEXT
CLIPPER WHICH SHOULD ARRIVE WED NIGHT. THIS WILL BRING ANOTHER
COOL DOWN FOR THURSDAY.
ONE COMMON THEME THROUGH THE END OF THE WEEKEND INTO NEXT WEEK
WILL BE BREEZY TO WINDY CONDITIONS. FAST MOVING SYSTEMS ARE
STEERED BY SWIFT WINDS ALOFT AND WITH HIGHS ABOVE SEASONAL
AVERAGES...GOOD MIXING WILL TAP INTO THE STRONGER WINDS. DAY TIME
SFC WINDS OF 15 TO 30 MPH...WITH HIGHER GUSTS...CAN BE EXPECTED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1134 PM CST THU JAN 9 2014
OR THE REST OF TONIGHT...EXPECT IFR CIGS AT THE KLBF TERMINAL
THROUGH 10Z FRIDAY. WINDS WILL SHIFT TO THE SOUTHWEST AROUND THIS
TIME...WHICH WILL ALLOW CIGS TO INCREASE TO 6000 FT AGL.
TOWARD SUNRISE FRIDAY...AN UPPER LEVEL TROUGH OF LOW PRESSURE WILL
APPROACH WESTERN AND NORTH CENTRAL NEBRASKA. THIS WILL LEAD TO
LOWERING CIGS AND AN INCREASED THREAT FOR SNOW FRIDAY MORNING. AT
THIS TIME...THE THREAT FOR SNOW IS GREATEST ACROSS PORTIONS OF
SOUTHWESTERN NEBRASKA. SNOW MAY IMPACT THE KLBF TERMINAL DURING
THE 16Z TO 20Z TIME FRAME FRIDAY MORNING. VISBYS MAY DROP DOWN TO
1SM WITH OVERCAST CIGS DOWN TO 1000 FT AGL. FOR THE KVTN
TERMINAL...THE THREAT FOR SNOW WILL BE FROM 14Z TO 18Z FRIDAY WITH
VISBYS POSSIBLY DOWN TO 2SM. CIGS AT THE KVTN TERMINAL WILL RANGE
FROM 1000 TO 1500 FT AGL FRIDAY MORNING INTO EARLY FRIDAY
AFTERNOON. FOR BOTH TERMINALS...CIGS WILL INCREASE TO VFR AFTER
22Z FRIDAY.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...MASEK
AVIATION...CLB
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1056 PM CST THU JAN 9 2014
.UPDATE...
ISSUED AT 1010 PM CST THU JAN 9 2014
UPDATED THE FORECAST FOR TONIGHT INTO FRIDAY TO INCREASE
TEMPERATURE AND DEWPOINT BY ROUGHLY 3 DEGREES OR SO ACROSS THE
BOARD AS SKY COVER AND WARM AIR ADVECTION ENSURE THAT COOLING WILL
BE TEMPERED.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 306 PM CST THU JAN 9 2014
FOCUS IS ON POTENTIAL FOR LIGHT PRECIPITATION AS A SHORTWAVE
TROUGH CROSSES THE CENTRAL PLAINS. WATER VAPOR IMAGERY INDICATED A
PROGRESSIVE PATTERN IN THE WESTERLIES WITH A SHORTWAVE TROUGH
DIGGING OVER THE ROCKIES EARLY THIS AFTERNOON. STRATUS AND SNOW
COVER HAS IMPACTED TEMPERATURES TODAY...WITH THE STRATUS SLOW TO
ERODE ACROSS OUR NORTHWEST ZONES...WHILE A NEW AREA OF STRATUS IS
ADVECTING NORTHWARD THROUGH KS EARLY THIS AFTN. TEMPS HAVE MANAGED
TO REACH THE MID 20S TO THE MID 30S SO FAR WITH A FEW MORE HOURS
OF INSOLATION LEFT.
FOR TONIGHT...SOUTHERLY LLVL FLOW INCREASES AHEAD OF THE TROUGH
EMERGING ONTO THE HIGH PLAINS. STRATUS WILL CONTINUE TO ADVECT TO
THE NORTH AND EAST AND SIMILAR TO THIS MORNING WE ARE LOOKING AT THE
POTENTIAL FOR FOG DEVELOPMENT. WINDS LOOK TO REMAIN STEADY ENOUGH
TO LIMIT DENSE FOG POTENTIAL BUT WILL NEED TO MONITOR AS THE RAP AND
HRRR INDICATE SOME LOCATIONS COULD SEE DENSE FOG. AHEAD OF THE
APPROACHING TROUGH...ISENTROPIC LIFT INCREASES AS INDICATED ON THE
295K SURFACE...PRIMARILY ORIENTED ACROSS OUR SOUTHEAST ZONES AND THE
LIFT OVER THE LLVL MOISTURE COULD LEAD TO FREEZING DRIZZLE TOWARD
MORNING AND THIS REMAINS IN THE FORECAST. ALSO ACROSS OUR WESTERN
ZONES...HAVE INTRODUCED LOW POPS TOWARD DAYBREAK FRIDAY AS THE
MID LEVEL TROUGH REACHES THIS AREA AND FORECAST SOUNDINGS FROM THE
RAP INITIALLY INDICATE THE POTENTIAL FOR FREEZING DRIZZLE...THEN
SATURATE TO MORE OF A IP/SN SOUNDING. HAVE MENTIONED ZL/IP FOR NOW
WITH PCPN TYPE TRANSITIONING TO R/S DURING THE DAY FRIDAY.
THERE IS STILL A FAIR AMOUNT OF UNCERTAINTY ON HOW MUCH PCPN WILL
BE AROUND DURING THE DAY ON FRIDAY WITH THE NAM REMAINING THE
DRIEST AMONGST THE MODELS. THE SURFACE COLD FRONT SWEEPS EASTWARD
FRIDAY MORNING...AND THE MID LEVEL TROUGH EXTENDS ACROSS OUR
CENTRAL CWA AROUND MIDDAY BEFORE TRANSLATING EASTWARD DURING THE
AFTERNOON. MID LEVEL MOISTURE INCREASES AS THE TROUGH MOVES IN AND
A NARROW BAND OF MID LEVEL FRONTOGENESIS/LIFT MOVE ACROSS FM LATE
MORNING INTO EARLY AFTERNOON...MORE ALIGNED ACROSS THE EASTERN
HALF OF OUR CWA. HAVE INCREASED POPS DURING THIS TIME FRAME AS SPC
WRF...GFS...ECMWF AND EVEN THE GEM INDICATE THE POTENTIAL FOR
BANDED PCPN. FORECAST SOUNDINGS INDICATE THE POSSIBILITY OF A
QUICK SHOT OF SNOW INITIALLY THEN DRY OUT/WARM BEHIND THE TROUGH
AND HAVE MAINTAINED A SIMPLE RAIN/SNOW MIX FOR PCPN TYPE ATTM.
WITH A WARMING TEMP PROFILE...GENERALLY DO NOT EXPECT MUCH IN THE
WAY OF ACCUMULATION BUT WOULD NOT BE SURPRISED TO SEE MINOR
AMOUNTS...GENERALLY UNDER ONE HALF OF AN INCH.
THE TROUGH AXIS SHIFTS EASTWARD BY FRIDAY EVENING WITH CONDITIONS
DRYING OUT/CLOUDS DECREASING IN SUBSIDENCE BEHIND THE DEPARTING
SYSTEM.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 306 PM CST THU JAN 9 2014
OVERALL...THE LONG TERM PERIOD LOOKS TO BE MOSTLY DRY.
BY FRIDAY NIGHT...THE MAIN TROUGH AXIS AND SURFACE LOW PRESSURE
SYSTEM HAVE SHIFTED TO THE EAST OF THE PLAINS...WHILE AN UPPER LEVEL
RIDGE AXIS SLOWLY BEGINS TO SHIFT ACROSS THE ROCKIES. WITH THIS
RIDGE...AND A DEVELOPING LEE SURFACE TROUGH...SOUTHWEST WINDS WILL
HELP BRING WARMER AIR TO THE PLAINS FOR SATURDAY. WENT A BIT ABOVE
GUIDANCE FOR SATURDAY...WITH MOSTLY SUNNY SKIES AND SOUTHWEST
WINDS...SEE NO REASON WHY WE CANNOT REACH THE UPPER 40S TO EVEN NEAR
50.
BY SUNDAY...A WEAK UPPER LEVEL DISTURBANCE SHIFTS ACROSS THE PLAINS
HELPING TO BREAK DOWN THE RIDGE. AS THE MAIN SURFACE LOW REMAINS
WELL TO THE NORTH OF THE REGION...AN ASSOCIATED COLD FRONT WILL PASS
THROUGH THE PLAINS SUNDAY. AT THIS POINT...WILL NOT REINTRODUCE
POPS TO THE FORECAST AS THE SURFACE LOW REMAINS WELL TO THE NORTH.
THAT BEING SAID...CANNOT RULE OUT A FEW SPRINKLES OR FLURRIES DURING
THE DAY AND NIGHT ON SUNDAY.
THE WAVE DEEPENS ACROSS THE PLAINS BY MONDAY...BRINGING COOLER 850
MB TEMPERATURES INTO THE OUTLOOK AREA. PERHAPS MONDAY MIGHT NEED TO
BE A TAD COOLER THAN FORECAST BUT STILL CURRENTLY EXPECTING MID 40S
FOR HIGHS.
THROUGH THE REST OF THE LONG TERM...NUMEROUS WAVES CONTINUES TO DIVE
SOUTH AND SKIRT ALONG THE PLAINS. HOWEVER...NONE OF THEM SUGGEST
ANYTHING IN THE WAY OF PRECIPITATION OR A LONG LASTING COLD SPELL.
IN FACT...RIDGING REBOUNDS ACROSS THE AREA BY WEDNESDAY BRINGING
TEMPERATURES BACK UP TO NEAR 50. TOWARDS THURSDAY...YET ANOTHER
UPPER LEVEL WAVE/CLOSED LOW WILL SHIFT THROUGH THE GREAT LAKES
REGION DRAGGING A COLD FRONT ACROSS THE AREA.
&&
.AVIATION...(FOR THE 06Z KGRI TAF THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1054 PM CST THU JAN 9 2014
STRATUS WILL CONTINUE DO DESCEND OVERNIGHT WITH LOWERING
VISIBILITY. MODELS ARE STILL NOT INITIALIZING WELL...SO GOING
WITH BEST GUESS. FOLLOWED MORE CLOSELY TO NAM MOS. FREEZING
DRIZZLE SHOULD REMAIN SOUTH OF THE TERMINAL OVERNIGHT. COULD GET
SOME RAIN/SNOW AS A TROUGH APPROACHES. WHEN THE WIND SWITCHES TO
THE WEST/NORTHWEST BEHIND THE TROUGH...VISIBILITY AND CEILING WILL
IMPROVE. CEILING SHOULD SCATTER BY FRIDAY EVENING AS THE TROUGH
CONTINUES TO DEPART.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...HEINLEIN
SHORT TERM...FAY
LONG TERM...SALTZMAN
AVIATION...HEINLEIN
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1012 PM CST THU JAN 9 2014
.UPDATE...
ISSUED AT 1010 PM CST THU JAN 9 2014
UPDATED THE FORECAST FOR TONIGHT INTO FRIDAY TO INCREASE
TEMPERATURE AND DEWPOINT BY ROUGHLY 3 DEGREES OR SO ACROSS THE
BOARD AS SKY COVER AND WARM AIR ADVECTION ENSURE THAT COOLING WILL
BE TEMPERED.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 306 PM CST THU JAN 9 2014
FOCUS IS ON POTENTIAL FOR LIGHT PRECIPITATION AS A SHORTWAVE
TROUGH CROSSES THE CENTRAL PLAINS. WATER VAPOR IMAGERY INDICATED A
PROGRESSIVE PATTERN IN THE WESTERLIES WITH A SHORTWAVE TROUGH
DIGGING OVER THE ROCKIES EARLY THIS AFTERNOON. STRATUS AND SNOW
COVER HAS IMPACTED TEMPERATURES TODAY...WITH THE STRATUS SLOW TO
ERODE ACROSS OUR NORTHWEST ZONES...WHILE A NEW AREA OF STRATUS IS
ADVECTING NORTHWARD THROUGH KS EARLY THIS AFTN. TEMPS HAVE MANAGED
TO REACH THE MID 20S TO THE MID 30S SO FAR WITH A FEW MORE HOURS
OF INSOLATION LEFT.
FOR TONIGHT...SOUTHERLY LLVL FLOW INCREASES AHEAD OF THE TROUGH
EMERGING ONTO THE HIGH PLAINS. STRATUS WILL CONTINUE TO ADVECT TO
THE NORTH AND EAST AND SIMILAR TO THIS MORNING WE ARE LOOKING AT THE
POTENTIAL FOR FOG DEVELOPMENT. WINDS LOOK TO REMAIN STEADY ENOUGH
TO LIMIT DENSE FOG POTENTIAL BUT WILL NEED TO MONITOR AS THE RAP AND
HRRR INDICATE SOME LOCATIONS COULD SEE DENSE FOG. AHEAD OF THE
APPROACHING TROUGH...ISENTROPIC LIFT INCREASES AS INDICATED ON THE
295K SURFACE...PRIMARILY ORIENTED ACROSS OUR SOUTHEAST ZONES AND THE
LIFT OVER THE LLVL MOISTURE COULD LEAD TO FREEZING DRIZZLE TOWARD
MORNING AND THIS REMAINS IN THE FORECAST. ALSO ACROSS OUR WESTERN
ZONES...HAVE INTRODUCED LOW POPS TOWARD DAYBREAK FRIDAY AS THE
MID LEVEL TROUGH REACHES THIS AREA AND FORECAST SOUNDINGS FROM THE
RAP INITIALLY INDICATE THE POTENTIAL FOR FREEZING DRIZZLE...THEN
SATURATE TO MORE OF A IP/SN SOUNDING. HAVE MENTIONED ZL/IP FOR NOW
WITH PCPN TYPE TRANSITIONING TO R/S DURING THE DAY FRIDAY.
THERE IS STILL A FAIR AMOUNT OF UNCERTAINTY ON HOW MUCH PCPN WILL
BE AROUND DURING THE DAY ON FRIDAY WITH THE NAM REMAINING THE
DRIEST AMONGST THE MODELS. THE SURFACE COLD FRONT SWEEPS EASTWARD
FRIDAY MORNING...AND THE MID LEVEL TROUGH EXTENDS ACROSS OUR
CENTRAL CWA AROUND MIDDAY BEFORE TRANSLATING EASTWARD DURING THE
AFTERNOON. MID LEVEL MOISTURE INCREASES AS THE TROUGH MOVES IN AND
A NARROW BAND OF MID LEVEL FRONTOGENESIS/LIFT MOVE ACROSS FM LATE
MORNING INTO EARLY AFTERNOON...MORE ALIGNED ACROSS THE EASTERN
HALF OF OUR CWA. HAVE INCREASED POPS DURING THIS TIME FRAME AS SPC
WRF...GFS...ECMWF AND EVEN THE GEM INDICATE THE POTENTIAL FOR
BANDED PCPN. FORECAST SOUNDINGS INDICATE THE POSSIBILITY OF A
QUICK SHOT OF SNOW INITIALLY THEN DRY OUT/WARM BEHIND THE TROUGH
AND HAVE MAINTAINED A SIMPLE RAIN/SNOW MIX FOR PCPN TYPE ATTM.
WITH A WARMING TEMP PROFILE...GENERALLY DO NOT EXPECT MUCH IN THE
WAY OF ACCUMULATION BUT WOULD NOT BE SURPRISED TO SEE MINOR
AMOUNTS...GENERALLY UNDER ONE HALF OF AN INCH.
THE TROUGH AXIS SHIFTS EASTWARD BY FRIDAY EVENING WITH CONDITIONS
DRYING OUT/CLOUDS DECREASING IN SUBSIDENCE BEHIND THE DEPARTING
SYSTEM.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 306 PM CST THU JAN 9 2014
OVERALL...THE LONG TERM PERIOD LOOKS TO BE MOSTLY DRY.
BY FRIDAY NIGHT...THE MAIN TROUGH AXIS AND SURFACE LOW PRESSURE
SYSTEM HAVE SHIFTED TO THE EAST OF THE PLAINS...WHILE AN UPPER LEVEL
RIDGE AXIS SLOWLY BEGINS TO SHIFT ACROSS THE ROCKIES. WITH THIS
RIDGE...AND A DEVELOPING LEE SURFACE TROUGH...SOUTHWEST WINDS WILL
HELP BRING WARMER AIR TO THE PLAINS FOR SATURDAY. WENT A BIT ABOVE
GUIDANCE FOR SATURDAY...WITH MOSTLY SUNNY SKIES AND SOUTHWEST
WINDS...SEE NO REASON WHY WE CANNOT REACH THE UPPER 40S TO EVEN NEAR
50.
BY SUNDAY...A WEAK UPPER LEVEL DISTURBANCE SHIFTS ACROSS THE PLAINS
HELPING TO BREAK DOWN THE RIDGE. AS THE MAIN SURFACE LOW REMAINS
WELL TO THE NORTH OF THE REGION...AN ASSOCIATED COLD FRONT WILL PASS
THROUGH THE PLAINS SUNDAY. AT THIS POINT...WILL NOT REINTRODUCE
POPS TO THE FORECAST AS THE SURFACE LOW REMAINS WELL TO THE NORTH.
THAT BEING SAID...CANNOT RULE OUT A FEW SPRINKLES OR FLURRIES DURING
THE DAY AND NIGHT ON SUNDAY.
THE WAVE DEEPENS ACROSS THE PLAINS BY MONDAY...BRINGING COOLER 850
MB TEMPERATURES INTO THE OUTLOOK AREA. PERHAPS MONDAY MIGHT NEED TO
BE A TAD COOLER THAN FORECAST BUT STILL CURRENTLY EXPECTING MID 40S
FOR HIGHS.
THROUGH THE REST OF THE LONG TERM...NUMEROUS WAVES CONTINUES TO DIVE
SOUTH AND SKIRT ALONG THE PLAINS. HOWEVER...NONE OF THEM SUGGEST
ANYTHING IN THE WAY OF PRECIPITATION OR A LONG LASTING COLD SPELL.
IN FACT...RIDGING REBOUNDS ACROSS THE AREA BY WEDNESDAY BRINGING
TEMPERATURES BACK UP TO NEAR 50. TOWARDS THURSDAY...YET ANOTHER
UPPER LEVEL WAVE/CLOSED LOW WILL SHIFT THROUGH THE GREAT LAKES
REGION DRAGGING A COLD FRONT ACROSS THE AREA.
&&
.AVIATION...(FOR THE 00Z KGRI TAF THROUGH 00Z FRIDAY EVENING)
ISSUED AT 555 PM CST THU JAN 9 2014
STRATUS WILL CONTINUE DO DESCEND OVERNIGHT WITH LOWERING
VISIBILITY. MODELS ARE NOT INITIALIZING WELL...SO GOING WITH BEST
GUESS. FOLLOWED MORE CLOSELY TO NAM MOS. FREEZING DRIZZLE SHOULD
REMAIN SOUTH OF THE TERMINAL OVERNIGHT. COULD GET SOME RAIN/SNOW
AS A TROUGH APPROACHES. WHEN THE WIND SWITCHES TO THE
WEST/NORTHWEST BEHIND THE TROUGH...VISIBILITY AND CEILING WILL
IMPROVE.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...HEINLEIN
SHORT TERM...FAY
LONG TERM...SALTZMAN
AVIATION...HEINLEIN
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
ISSUED BY NATIONAL WEATHER SERVICE CHARLESTON SC
1249 PM EST FRI JAN 10 2014
.SYNOPSIS...
A COASTAL FRONT HAS PUSHED INLAND TODAY...ALLOWING HUMID
SUBTROPICAL AIR INTO THE AREA. AN EASTWARD MOVING COLD FRONT WILL
SWEEP ACROSS THE AREA LATE SATURDAY. WEAK HIGH PRESSURE WILL COVER
THE SOUTHEAST STATES SUNDAY AND MONDAY. LOW COAST LOW PRESSURE
WILL PASS SOUTH OF THE CAROLINAS TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MOST PRECIP HAS MOVED OUT OF THE CWA WITH ONLY SMALL RETURNS
SHOWING ON RADAR. SLIGHT MODEL DIFFERENCES WITH RESPECT TO SHOWERS
THIS AFTERNOON. HRRR AND NAM FLIRT WITH SHOWERS OVER THE WESTERN
COUNTIES. KEPT POPS IN THE 40 TO 60 PERCENT RANGE TO ACCOUNT FOR
DEVELOPING SHOWERS AS TEMPS...HUMIDITY AND ISENTROPIC ASCENT
CONTINUE TO INCREASE. THERE IS ROUGHLY A 20 DEGREE TEMP GRADIENT
BETWEEN THE COASTAL AND INLAND COUNTIES AS THE WARM FRONT HAS
PROGRESSED WEST. STILL EXPECT THIS FEATURE TO STALL NEAR THE I95
CORRIDOR
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
EXPECT A WARM AND WET FIRST HALF OF THE WEEKEND IN SHOWERS AND
ISOLATED THUNDERSTORMS AS COLD FRONT MAKES ITS WAY THROUGH THE
CAROLINAS ON SATURDAY. ENTRENCHED IN THE WARM SECTOR ON
SATURDAY...TEMPS WILL REACH INTO THE 70S MOST PLACES WITH DEWPOINT
TEMPS INTO THE MID 60S. LLJ INCREASES UP TO 50 KTS WITH PCP WATER
VALUES REACHING ABOVE 1.5 INCHES BY SAT AFTN. OVERALL CAPE SEEMS
FAIRLY LOW BUT MAY SEE SOME STRONGER WINDS ALOFT MAKE IT DOWN TO
SURFACE IN DEEPER CONVECTIVE DEVELOPMENT THROUGH SAT AFTN INTO
EARLY SAT EVENING. ONCE COOLING OCCURS AT SURFACE EXPECT ANY
STRONGER CONVECTION TO WANE. SPC CONTINUES TO KEEP AREA IN SLIGHT
RISK OF SEVERE THUNDERSTORMS WITH MAIN THREAT OF POTENTIAL FOR
DAMAGING WIND GUSTS. BEST UPPER LEVEL SUPPORT LOOKS LIKE IT WILL
BE HELD BACK TO THE WEST WITH H5 TROUGH CROSSING THE COAST AFTER
MIDNIGHT. EXPECT HEAVIER RAIN IN SHOWERS AND THUNDERSTORMS TO
PRODUCE RAINFALL TOTALS UP AROUND AN INCH OR HIGHER IN SPOTS.
COLD FRONT WILL MAKE ITS WAY OFF SHORE BY MIDNIGHT SAT NIGHT WITH
DRIER AIR ADVECTING IN AS HIGH PRESSURE BUILDS IN BEHIND IT. SKIES
WILL CLEAR WITH DEEP DRY COLUMN BY SUNDAY WITH PCP WATER VALUES DOWN
CLOSE TO A QUARTER OF AN INCH. RIDGE OF HIGH PRESSURE WILL BUILD
RAPIDLY EAST BEHIND FRONT WITH WINDS MAINTAINING A STRONG WESTERLY
COMPONENT TO THE FLOW. THIS WILL ALLOW FOR QUICK RECOVERY OF TEMPS.
THE 850 TEMPS UP AROUND 12C WILL DROP DOWN CLOSE TO 2 C BY SUN
MORNING BUT WILL BOUNCE BACK AS WINDS COME AROUND TO THE W-SW
THROUGH SUNDAY.
HIGH TEMPS ON SAT WILL REACH INTO THE 70S BUT WILL DROP DOWN BEHIND
COLD FRONT SAT NIGHT DOWN BELOW 50 BY MORNING. SUNDAY WILL RECOVER
TO AROUND 60 UNDER SUNNY SKIES AIDED BY DECENT DOWNSLOPE WESTERLY
WIND. TEMPS SUNDAY NIGHT WILL BE CLOSER TO NORMAL WITH MID TO UPPER
30S MOST PLACES.
&&
.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
WINDS WILL ALREADY BE BACK AROUND TO THE SOUTHWEST ON MONDAY WITH
WARMER AND MOISTER AIR ADVECTING OVER THE CAROLINAS IN A MUCH MORE
PROGRESSIVE PATTERN. MODELS STILL SHOWING HIGH PRESSURE OFF THE
COAST BY MONDAY AS DEEPENING MID TO UPPER TROUGH PUSHES NEXT
SYSTEM EAST. THE GFS RUNNING A BIT SLOWER AGAIN LINING UP SLIGHTLY
BETTER WITH ECMWF BUT STILL KEEPS WAVE OF LOW PRESSURE RIDING UP
FROM THE GULF FARTHER EAST WITH MOST PCP LINING UP RIGHT ALONG THE
COAST OR IN THE ATLANTIC WATERS BY MON NIGHT. OVERALL EXPECT
INCREASING CLOUDS BY LATE MONDAY WITH BEST CHC OF PCP OVERNIGHT
MONDAY AS LOW MOVES UP THE COAST AND COLD FRONT APPROACHES FROM
THE W-NW. WILL NOT TAP INTO TOO MUCH IN THE WAY OF GULF MOISTURE
AND THEREFORE NOT COUNTING ON GREAT QPF MON NIGHT AS PCP WATER
VALUES REACH AROUND AN INCH BEFORE DROPPING DOWN TO A QUARTER OF
INCH BY TUES AFTERNOON IN DEEP DRY AND COOL ADVECTION. WILL GET
ANOTHER REINFORCING SHOT OF COOL AIR BY LATE WEDNESDAY AS MID TO
UPPER TROUGH DIGS DOWN ACROSS THE SOUTHEAST AND MOVES THROUGH.
WITH FLOW REMAINING PROGRESSIVE THROUGH THE WEEK...HIGH PRESSURE
BUILDING UP FROM THE GULF ON THURS WILL SHIFT OFF SHORE BY FRIDAY
WITH A TRANSITION TO A SOUTHERLY RETURN FLOW BRIEFLY THROUGH FRI.
TEMPS WILL REMAIN CLOSER TO NORMAL AFTER BEING KNOCKED DOWN BEHIND
COLD FRONT ON TUES...WITH READINGS IN THE MID 50S FOR HIGHS AND
30S AT NIGHT THROUGH MUCH OF THE WEEK AHEAD.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
SHOWERS HAVE MOVED OUT OF THE CWA AND MOST TERMINALS ARE EXPECTED
TO BE VFR. THERE ARE SOME SCATTERED AREAS OF MVFR CIGS WHERE THE
DEW POINT DEPRESSIONS ARE SMALLER. A VERY MOIST AIR MASS WILL BE IN
PLACE OVERNIGHT...EXPECT AN INCREASED POTENTIAL FOR FOG/STRATUS.
BEST CHANCES FOR IFR CIGS WILL BE AT KFLO/KLBT...WHILE KCRE/KMYR
COULD BATTLE SEA FOG AS THE WINDS BECOME MORE SOUTHERLY TONIGHT.
EXTENDED OUTLOOK...SHOWERS WITH ISOLATED T-STORMS AND MVFR/IFR
CONDITIONS ON SATURDAY. ALSO EXPECT GUSTY SOUTH WINDS ON SATURDAY
AHEAD OF THE COLD FRONT. VFR SUNDAY THROUGH TUESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
SEAS WILL GRADUALLY BUILD AS HIGH AS 6-7 FEET OUT NEAR 20 MILES
FROM SHORE. WIND DIRECTIONS WILL VEER MORE SOUTHERLY TONIGHT AS A
COLD FRONT CROSSES THE LOWER MISSISSIPPI VALLEY. THIS WILL
INCREASE THE TIME AIR PARCELS PASS OVER THE COLDER NEARSHORE
WATERS ALONG THE SOUTH CAROLINA COAST AND ALSO JUST NORTH OF CAPE
FEAR...OPENING THE WINDOW FOR PATCHY SEA FOG AS THE AIR IS CHILLED
BY ITS PASSAGE ACROSS THE COLD NEARSHORE OCEAN. WIND SPEEDS SHOULD
DIMINISH SLIGHTLY AS WELL...PERHAPS LEAVING A PERIOD OF 6-10 HOURS
WHERE WE DON`T MEET SMALL CRAFT ADVISORY CONDITIONS TONIGHT INTO
EARLY SATURDAY MORNING. AFTER COLLABORATING WITH THE WEEKEND
FORECASTER WHO EXPECTS INCREASING WIND SPEEDS SATURDAY...THE
ADVISORY WILL REMAIN POSTED INTO SUNDAY.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
WINDS WILL CONTINUE TO INCREASE AND VEER AROUND FROM THE S TO SW
ON SATURDAY AHEAD OF THE APPROACHING COLD FRONT...BECOMING 20-25
KTS OR MORE...WITH GUSTS TO GALE FORCE POSSIBLE SATURDAY
EVE...BEFORE THE COLD FRONT CROSSES BY WITH A WIND SHIFT TO THE
W-NW AT AROUND 20 KTS OVERNIGHT. THESE INCREASING SOUTHERLY WINDS
AHEAD OF THE FRONT WILL CONTINUE TO DRIVE SEAS UP TO 6 TO 9 FT BY
LATE SATURDAY MAINTAINING SMALL CRAFT ADVISORY CONDITIONS THROUGH
SATURDAY INTO SUNDAY MORNING. WINDS AND SEAS SHOULD PEAK JUST
AHEAD OF THE COLD FRONT SAT EVENING. A GALE WARNING MAY BE NEEDED
INSTEAD IF WINDS END UP JUST A BIT STRONGER SAT EVENING.
AS WINDS BECOME OFF SHORE BEHIND COLD FRONT AFTER MIDNIGHT SAT
NIGHT...THE SEAS WILL DROP OFF ESPECIALLY NEAR SHORE. WINDS SHOULD
DIMINISH TO 15 TO 20 KTS BY SUN MORNING DECREASING FURTHER THROUGH
THE DAY AS HIGH PRESSURE MOVES ACROSS THE SOUTHEAST. BY NOON ON
SUNDAY WINDS AND SEAS SHOULD BEGIN TO DROP BELOW SCA THRESHOLDS
AND WILL DROP RAPIDLY DOWN TO 2 TO 4 FT BY SUN NIGHT AS WINDS
LIGHTEN AS HIGH PRESSURE MOVES OVERHEAD.
LONG TERM /MONDAY THROUGH TUESDAY...
RETURN FLOW AROUND 10 TO 15 KTS WILL INCREASE THROUGH LATE MONDAY
INTO TUESDAY AS HIGH PRESSURE SHIFTS FARTHER OFF SHORE AND A COLD
FRONT APPROACHES FROM THE NORTHWEST AND WAVE OF LOW PRESSURE MOVES
UP FROM THE GULF COAST INTO THE ATLANTIC WATERS. THE WARMER WINDS
MOVING OVER THE VERY COOL SHELF WATERS WILL MAINTAIN A MORE STABLE
MARINE LAYER PREVENTING THE WINDS FROM REACHING THE OCEAN SURFACE.
SEAS WILL THEREFORE NOT HAVE MUCH TIME TO BUILD BEFORE COLD FRONT
MOVES THROUGH AND WINDS SHIFT AROUND TO THE W-NW AGAIN BY TUES
AFTN. THE SEAS WILL QUICKLY BUILD OVER THE OUTER WATERS OFF CAPE
FEAR THROUGH MON AFTN AND COULD REACH 5 FT BEFORE DROPPING AGAIN
THROUGH EARLY TUES BEHIND FRONT. WNA SHOWING WINDS BACKING AND
INCREASING THROUGH TUES NIGHT ONCE AGAIN AS HIGH PRESSURE BUILDS
IN FROM THE WEST.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST SUNDAY FOR AMZ250-252-254-
256.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
AREA FORECAST DISCUSSION
NWS RALEIGH NC
646 AM EST FRI JAN 10 2014
.SYNOPSIS...MOISTURE INCREASES OVER THE REGION TODAY AS HIGH
PRESSURE MOVES EAST INTO THE ATLANTIC. A STRONG COLD FRONT SWEEPS
ACROSS THE REGION SATURDAY. HIGH PRESSURE BUILDS BACK IN ON SUNDAY.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 305 AM FRIDAY...
WATER VAPOR IMAGERY SHOWS AT LEAST MODEST MID-LEVEL SHORTWAVES
MOVING TOWARD CENTRAL NORTH CAROLINA FROM THE SOUTHWEST...WHILE THE
00Z UPPER-AIR INFORMATION NOTED INCREASING 700MB AND 850MB MOISTURE
UPSTREAM...AND 500MB DIFFLUENCE JUST TO OUR WEST. WITH THE APPROACH
OF THE SHORTWAVES...MODEL FORECAST LIFT INCREASES AS WELL...WITH
MODEST UPPER-LEVEL DIFFLUENCE TAKING PLACE FOR MUCH OF THE DAY.
GUIDANCE POPS ARE HIGH...AND CURRENTLY THIS SEEMS REASONABLE GIVEN
THE AVAILABLE SYNOPTIC LIFT AND INCREASING MOISTURE. THE VARIETY OF
WRF GUIDANCE IS BULLISH ON PRECIPITATION CHANCES AS WELL...WITH THE
LATEST HRRR WRF NOTING LIKELY CHANCES FOR PRECIPITATION AS FAR EAST
AS THE NORTHEAST COASTAL PLAIN EARLY THIS AFTERNOON. WILL FORECAST
BASICALLY CATEGORICAL CHANCES FOR RAIN TODAY MAINLY ALONG AND WEST
OF U.S. 1...AND ESSENTIALLY LIKELY CHANCES EAST OF THERE. THE LATEST
SPC MESOANALYSIS SHOWED THE WET-BULB ZERO LINE NORTH OF CENTRAL
NORTH CAROLINA...BASICALLY NEAR OR NORTH OF THE VIRGINIA BORDER
COINCIDENT WITH THE PIEDMONT...AND IN MANY AREAS THE SURFACE DEW
POINT WAS APPROACHING...OR EVEN ABOVE...30 DEGREES. THE IMMEDIATE
TRIAD HAD DEW POINTS STILL AROUND 20...BUT GIVEN THE KEXX DEW POINT
ABOVE 32...AND TEMPERATURES IN THE TRIAD AROUND 40...THINK THE
POTENTIAL FOR ANY FREEZING PRECIPITATION IS VERY SLIM AND THIS
FORECAST WILL CONTINUE TO BE ALL LIQUID.
TEMPERATURES TODAY WILL BE SOMEWHAT CHALLENGING...BUT WITH THE CLOUD
COVER AND PRECIPITATION MOVING IN FROM THE SOUTHWEST...IT MAY BE
DIFFICULT FOR MUCH OF A RISE. WILL KEEP IN MIND...THOUGH...THAT
TEMPERATURES IN MANY LOCATIONS ARE AT LEAST AROUND 40...AND IN THE
MID 40S IN PARTS OF THE SANDHILLS AND SOUTHERN COASTAL PLAIN. WILL
STILL LIKELY HEDGE TOWARD THE COOLER SIDE OF GUIDANCE...OR A BLEND
SUCH AS TOWARD THE TRIAD WHERE THE MET 39 MAY BE TOO COOL BUT THE
MAV 46 MAY BE TOO WARM GIVEN THE EXPECTED NORTHEAST FLOW AND MORE
AREAS OF RAIN THROUGHOUT THE DAY. STILL...A GOOD TEMPERATURE RANGE
ANTICIPATED FROM AROUND 40 TO THE LOWER 40S NORTHWEST...TO THE LOWER
60S TOWARD KCTZ.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
AS OF 645 AM FRIDAY...
TONIGHT...THE BETTER LIFT THAT IS FORECAST BY THE GFS TODAY MOVES
OFF TO THE EAST...BEFORE BETTER LIFT TAKES PLACE AGAIN ALONG AND IN
ADVANCE OF THE STRONG COLD FRONT TO MOVE THROUGH SATURDAY. GFS BUFR
SOUNDINGS SHOW THE LOW-LEVELS REMAINING FAIRLY SATURATED ACROSS
CENTRAL NORTH CAROLINA...AS 850MB WINDS START TO INCREASE OVERNIGHT.
WHILE 850MB THETA-E VALUES INCREASE STEADILY TODAY INTO THIS
EVENING...THE GFS DOES FORECAST A PERIOD OF DECREASING 850MB THETA-E
LATE TONIGHT INTO EARLY SATURDAY MORNING. IT IS IN THIS SAME PERIOD
WHERE THE STATISTICAL GUIDANCE SHOWS A SHORT DIMINISHING TREND IN
CHANCES FOR RAIN...AND THE CONSENSUS OF WRF GUIDANCE NOTES LESSER
COVERAGE OF PRECIPITATION. THE CURRENT THINKING IS THAT SCATTERED TO
NUMEROUS AREAS OF RAIN AND DRIZZLE THROUGH THE EVENING AND INTO THE
OVERNIGHT HOURS MAY BECOME MORE ISOLATED TO SCATTERED LATE
TONIGHT...POSSIBLY INCREASING AGAIN TOWARD THE YADKIN RIVER VERY
LATE TONIGHT INTO EARLY SATURDAY IN GOOD ISENTROPIC LIFT ON THE 295K
AND 300K SURFACES. OVERNIGHT LOWS MAY OCCUR EARLY BEFORE
TEMPERATURES SLOWLY INCREASE DURING THE NIGHT. ONCE AGAIN WILL LEAN
TOWARD A BLEND OF THE GUIDANCE IN THE TRIAD WHERE THERE IS THE
LARGEST DISCREPANCY BETWEEN THE MAV AND THE MET...AND RIGHT NOW
MAINLY ON THE COOLER SIDE ELSEWHERE THOUGH...AS NOTED...READINGS
SHOULD GRADUALLY RISE OVERNIGHT.
NOTED IN THE RECENT FORECAST UPDATE PATCHY FOG PARTICULARLY IN THE
WEST AND NORTHWEST PIEDMONT MAINLY THIS EVENING. IN THE COOLER
AREAS...AS MOISTURE INCREASES AND BEFORE SURFACE WINDS START TO
INCREASE LATER AT NIGHT...PATCHY FOG COULD RESULT. THE SREF
PROBABILISTIC GUIDANCE SUGGESTS A HIGH PROBABILITY OF VISIBILITIES
LESS THAN ONE MILE IN MANY AREAS WEST OF U.S. 1 THROUGH THE
OVERNIGHT HOURS...BUT CURRENTLY THINK IF THE WINDS START TO INCREASE
IN SPEED THIS COULD LIMIT SOME OF THE LATE NIGHT FOG POTENTIAL. THIS
WILL BE ASSESSED FURTHER DURING THE DAY.
SATURDAY INTO SATURDAY NIGHT...PRECIPITATION CHANCES INCREASE
SOLIDLY WITH THE APPROACH AND PASSAGE OF THE FRONT. HEIGHT FALLS
ALOFT SHOULD BE STRONG AS WELL AS THE MID-LEVEL TROUGH APPROACHES
FROM THE WEST LATE IN THE DAY SATURDAY. INSTABILITY IS NOT GREAT
BASED ON THE MODEL SOUNDING LAPSE RATES AND THE MIXED-LAYER CAPE
FORECAST ON THE GFS IN THE LOWEST KM. IN FACT...THE MLCAPE REGISTERS
ONLY TOWARD THE FAR SOUTHEAST...FROM ABOUT KMEB TO KGSB OR SO...
WITH VALUES OF 500J/KG OR LESS. INTERESTINGLY...THOUGH...DOWNDRAFT
CAPE INCREASES NOTICABLY ALONG AND NORTH OF U.S. 64 DURING THE
AFTERNOON TO VALUES AROUND 700J/KG. EVEN THOUGH THE GFS BUFR
SOUNDINGS SHOW THE MIXED LAYER TO BE FAIRLY SHALLOW SATURDAY
AFTERNOON...WHERE THERE IS EVEN A BIT OF INSTABILITY...WINDS ALOFT
INCREASE RAPIDLY TO 40 TO 50KT. THUNDER...OVERALL...MAY BE SOMEWHAT
DIFFICULT TO COME BY...BUT GIVEN THE 40 TO 50KT 925MB WINDS IN THE
AFTERNOON...AND 60 TO 70KT AT 850MB ALONG WITH GOOD THICKNESS
PACKING AS THE FRONT MOVES THROUGH...A STRONGLY-FORCED LINE OF
SHOWERS COULD TAKE PLACE RESULTING IN GUSTY WINDS. WILL NOTE THE
POTENTIAL FOR STRONG TO SEVERE CONDITIONS IN THE HWO FOR SATURDAY...
MAINLY IN THE AFTERNOON AND...FOR THE MOST PART...EAST OF THE FAR
WESTERN PIEDMONT. MAV GUIDANCE FOR HIGHS SATURDAY ARE WARM...AND AT
KRDU ARE ONLY A COUPLE OF DEGREES SHY OF THE RECORD. FOR NOTE...
HIGH TEMPERATURE RECORDS ARE 73 AT KGSO IN 1949...AND 73 AT KRDU AND
79 AT KFAY IN 1930. ONCE AGAIN...WILL CURRENTLY PLAN A FORECAST WITH
A BLEND OF THE MAV AND MET MOS.
DRYING TAKES PLACE SATURDAY NIGHT AND THE CHANCES FOR PRECIPITATION
DIMINISH WEST TO EAST AS K INDICES GO MOSTLY NEGATIVE BY 12Z SUNDAY.
GUSTY WINDS IN THE EVENING DIMINISH SOME OVERNIGHT...AND THE
APPROACH OF THE STRONG TROUGH ALOFT COULD LINGER CLOUDS AND SOME
RAIN CHANCES THROUGH THE EVENING...AND INTO THE EARLY PART OF THE
OVERNIGHT HOURS EAST OF U.S. 1. OVERNIGHT LOWS AROUND 40 TO THE MID
40S.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 305 AM FRIDAY...
THE LONG WAVE TROUGH AXIS WILL BE EXITING THE EAST COAST EARLY
SUNDAY...WITH INCREASING HEIGHTS ACROSS OUR REGION THROUGH THE DAY.
AT THE SURFACE...A HIGH PRESSURE CENTER WILL QUICKLY MOVE FROM THE
NORTHERN GULF COAST AT 12Z SUNDAY TO A POSITION OFF THE SE COAST BY
00Z MONDAY. FOR OUR SENSIBLE WEATHER...SUBSIDENCE AND SUBSEQUENT
DRYING WILL YIELD MOSTLY SUNNY SKIES DURING THE DAY. LOW LEVEL
THICKNESSES...WHILE EXPECTED TO BOTTOM OUT AROUND 1305M EARLY IN THE
DAY BEHIND THE DEPARTING TROUGH...WILL INCREASE TO AROUND 1330M BY
LATE AFTERNOON. THUS LOOK FOR HIGHS TO RANGE FROM THE MID 50S NW TO
LOWER 60S SE. SUNDAY NIGHT...THE MID/UPR RIDGE AXIS WILL BE TO OUR
EAST AND THE NEXT TROUGH WILL BE MOVING ACROSS THE PLAINS.
INCREASING SW FLOW ALOFT WILL RESULT IN THICKENING MID/HI CLOUDS
ACROSS OUR AREA. LOWS IN THE MID-UPR 30S.
MONDAY WILL SEE INCREASING CLOUDS AHEAD OF THE AFOREMENTIONED
TROUGH...WHICH WILL BE CROSSING THE MISS RIVER VALLEY BY 00Z
TUESDAY. HIGHS WILL CLIMB WELL ABOVE NORMAL IN THE PRE-FRONTAL
AIRMASS. HIGHS IN THE LOWER 60S. THEN...SUBSTANTIAL DIFFERENCES
CONTINUE IN THE LATEST GFS AND ECMWF RUNS REGARDING THE TIMING AND
STRENGTH OF THE PROGRESSIVE BUT DAMPENING SHORT WAVE PROGGED TO LIFT
NE AND ACROSS OUR AREA MONDAY NIGHT (PER GFS) OR LATE MONDAY NIGHT
AND DURING THE DAY TUESDAY (PER ECMWF). THE ECMWF IS THE WETTER OF
THE TWO THANKS TO ITS STRONGER SHORT WAVE AND MUCH-STRONGER
(COMPARED TO GFS) LOW LEVEL JET AND MOISTURE TRANSPORT...THUS
SHOWING AROUND 1/2 INCH QPF. IF THE TRENDS GO THE ECMWF WAY WITH
FUTURE RUNS...WILL ALSO NEED TO KEEP A CLOSE EYE ON THERMAL PROFILES
AND THE POTENTIAL FOR CONVECTION ON TUESDAY ALONG AND AHEAD OF THE
COLD FRONT.
BY LATE TUESDAY...THE COLD FRONT WILL BE TO OUR EAST...WITH
SUBSIDENCE...CAA...AND DRYING IN IT`S WAKE. WE`LL THEN TURN OUR
ATTENTION TO THE NEXT SHORT WAVE PROGGED TO DROP SE ACROSS THE
MIDWEST AND OH VALLEY TUESDAY NIGHT. THE GFS AND ECMWF ARE IN DECENT
AGREEMENT EARLY WITH THIS SYSTEM WHILE IT`S UPSTREAM OF US...BUT
THEN START TO DIFFER QUITE DRAMATICALLY AS THE WAVE BOTTOMS OUT
ACROSS THE CAROLINAS. THE ECMWF IS MUCH SLOWER AND CLOSES OFF THE
MID LEVEL WAVE AS IT CROSSES THE CAROLINAS AND RESULTS IN SFC
CYCLOGENESIS JUST OFF THE COAST. THE GFS ON THE OTHER HAND IS MUCH
FASTER WITH AN OPEN WAVE THAT QUICKLY MOVES ACROSS AND EXITS OUR
AREA. WHILE FORECAST SOUNDINGS AND PARTIAL THICKNESSES FROM BOTH
SUGGEST THAT THE AIRMASS WILL LIKELY BE COLD ENOUGH FOR A MIX OF
RAIN/SNOW OR ALL SNOW...BOTH SOLUTIONS ARE RATHER MOISTURE-STARVED
WITH NO GULF AND VERY LITTLE ATLANTIC MOISTURE...UNTIL THE SYSTEM IS
TO OUR EAST. SO FOR NOW...WILL KEEP POPS WITH THIS SYSTEM LIMITED TO
CLIMO VALUES. THIS NW FLOW SYSTEM APPEARS TO BE THE LOWER-IMPACT
TYPE THAT RESULTS IN PERHAPS A FEW FLURRIES...OR PERHAPS A BRIEF
SNOW SHOWER OR TWO...WHICH WOULD OCCUR LATE WEDNESDAY OR WEDNESDAY
NIGHT.
THEN FOR THE LATTER HALF OF THE WEEK...THURSDAY LOOKS DRY WITH A
SHORTWAVE RIDGE CROSSING THE AREA...THEN ANOTHER MOISTURE-STARVED
SHORTWAVE TROUGH IS PROGGED TO MOVE ACROSS UNEVENTFULLY BY WEEKS
END. MEX TEMPS LOOK TOO HIGH FOR THE LATTER HALF OF NEXT WEEK GIVEN
LOW LEVEL THICKNESSES...THUS WILL MAKE APPROPRIATE DOWNWARD
ADJUSTMENTS...TEMPS NEAR OR SLIGHTLY BELOW NORMAL DURING THIS TIME.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AS OF 645 AM FRIDAY...
GRADUALLY DIMINISHING CONDITIONS WILL CONTINUE TO OCCUR IN CENTRAL
NORTH CAROLINA DURING THE 12Z VALID TAF PERIOD. NUMEROUS AREAS OF
RAIN WERE MOVING INTO THE WESTERN PIEDMONT WITH THE RAIN MORE
SCATTERED IN MOST AREAS ALONG AND EAST OF U.S. 1. AS RAIN
OCCURS...ANTICIPATE CEILINGS LOWERING TO MVFR...THEN AS MOISTURE
CONTINUES TO INCREASE ALL MODELS SUPPORT CEILINGS FALLING TO IFR OR
LIFR. RAIN WILL OCCUR LATEST TOWARD KRWI...AND ANTICIPATE AREAS OF
LIGHT RAIN AND/OR DRIZZLE CONTINUING FROM LATE TODAY THROUGH THE
EVENING. GFS MODEL SOUNDINGS STILL SHOW WINDS VEERING ALOFT AND
INCREASING IN SPEED...STILL SUGGESTING WIND SPEEDS GRADUALLY
INCREASING THROUGH AND ABOVE 2000FT. BETWEEN 09Z AND 12Z THERE IS A
MARGINAL LLWS SIGNAL COINCIDENT WITH AN EXPECTED SURFACE WIND
INCREASE...SO AGAIN HAVE KEPT LLWS OUT OF THE TAFS FOR THE 12Z
ISSUANCE. REGARDLESS...AVIATION INTERESTS SHOULD BE PREPARED FOR
VEERING WINDS WITH HEIGHT AS THEY INCREASE...WITH VALUES AT LEAST TO
35KT AT AND JUST ABOVE 2000FT LATE TONIGHT.
BEYOND THE 12Z VALID TAF PERIOD...ALONG WITH SOME CONCERNS FOR
LLWS...WIDESPREAD SUB-VFR CONDITIONS...MANY AREAS IFR OR
LIFR...CONTINUE INTO SATURDAY...AHEAD OF A STRONG COLD FRONT THAT
SWEEPS ACROSS CENTRAL NORTH CAROLINA. WHILE AN ISOLATED THUNDERSTORM
COULD OCCUR SATURDAY IN CENTRAL NORTH CAROLINA...A BAND OF SHOWERS
PRODUCING GUSTY WESTERLY WINDS MOVING ACROSS CENTRAL NORTH CAROLINA
DURING THE AFTERNOON AND VERY EARLY EVENING COULD CERTAINLY POSE AN
AVIATION CONCERN. AVIATION INTERESTS OPERATING SATURDAY SHOULD
MONITOR THE LATEST CONVECTIVE AVIATION INFORMATION AND THE TIMING OF
ANY SUCH BAND. CONDITIONS RAPIDLY BECOME VFR SATURDAY NIGHT
CONTINUING INTO MONDAY. A PERIOD OR TWO OF MVFR CONDITIONS IS
POSSIBLE IN LIGHT PRECIPITATION LATE MONDAY NIGHT INTO TUESDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...DJF
SHORT TERM...DJF
LONG TERM...NP
AVIATION...DJF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
307 AM EST FRI JAN 10 2014
.SYNOPSIS...MOISTURE INCREASES OVER THE REGION TODAY AS HIGH
PRESSURE MOVES EAST INTO THE ATLANTIC. A STRONG COLD FRONT SWEEPS
ACROSS THE REGION SATURDAY. HIGH PRESSURE BUILDS BACK IN ON SUNDAY.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 305 AM FRIDAY...
WATER VAPOR IMAGERY SHOWS AT LEAST MODEST MID-LEVEL SHORTWAVES
MOVING TOWARD CENTRAL NORTH CAROLINA FROM THE SOUTHWEST...WHILE THE
00Z UPPER-AIR INFORMATION NOTED INCREASING 700MB AND 850MB MOISTURE
UPSTREAM...AND 500MB DIFFLUENCE JUST TO OUR WEST. WITH THE APPROACH
OF THE SHORTWAVES...MODEL FORECAST LIFT INCREASES AS WELL...WITH
MODEST UPPER-LEVEL DIFFLUENCE TAKING PLACE FOR MUCH OF THE DAY.
GUIDANCE POPS ARE HIGH...AND CURRENTLY THIS SEEMS REASONABLE GIVEN
THE AVAILABLE SYNOPTIC LIFT AND INCREASING MOISTURE. THE VARIETY OF
WRF GUIDANCE IS BULLISH ON PRECIPITATION CHANCES AS WELL...WITH THE
LATEST HRRR WRF NOTING LIKELY CHANCES FOR PRECIPITATION AS FAR EAST
AS THE NORTHEAST COASTAL PLAIN EARLY THIS AFTERNOON. WILL FORECAST
BASICALLY CATEGORICAL CHANCES FOR RAIN TODAY MAINLY ALONG AND WEST
OF U.S. 1...AND ESSENTIALLY LIKELY CHANCES EAST OF THERE. THE LATEST
SPC MESOANALYSIS SHOWED THE WET-BULB ZERO LINE NORTH OF CENTRAL
NORTH CAROLINA...BASICALLY NEAR OR NORTH OF THE VIRGINIA BORDER
COINCIDENT WITH THE PIEDMONT...AND IN MANY AREAS THE SURFACE DEW
POINT WAS APPROACHING...OR EVEN ABOVE...30 DEGREES. THE IMMEDIATE
TRIAD HAD DEW POINTS STILL AROUND 20...BUT GIVEN THE KEXX DEW POINT
ABOVE 32...AND TEMPERATURES IN THE TRIAD AROUND 40...THINK THE
POTENTIAL FOR ANY FREEZING PRECIPITATION IS VERY SLIM AND THIS
FORECAST WILL CONTINUE TO BE ALL LIQUID.
TEMPERATURES TODAY WILL BE SOMEWHAT CHALLENGING...BUT WITH THE CLOUD
COVER AND PRECIPITATION MOVING IN FROM THE SOUTHWEST...IT MAY BE
DIFFICULT FOR MUCH OF A RISE. WILL KEEP IN MIND...THOUGH...THAT
TEMPERATURES IN MANY LOCATIONS ARE AT LEAST AROUND 40...AND IN THE
MID 40S IN PARTS OF THE SANDHILLS AND SOUTHERN COASTAL PLAIN. WILL
STILL LIKELY HEDGE TOWARD THE COOLER SIDE OF GUIDANCE...OR A BLEND
SUCH AS TOWARD THE TRIAD WHERE THE MET 39 MAY BE TOO COOL BUT THE
MAV 46 MAY BE TOO WARM GIVEN THE EXPECTED NORTHEAST FLOW AND MORE
AREAS OF RAIN THROUGHOUT THE DAY. STILL...A GOOD TEMPERATURE RANGE
ANTICIPATED FROM AROUND 40 TO THE LOWER 40S NORTHWEST...TO THE LOWER
60S TOWARD KCTZ.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
AS OF 305 AM FRIDAY...
TONIGHT...THE BETTER LIFT THAT IS FORECAST BY THE GFS TODAY MOVES
OFF TO THE EAST...BEFORE BETTER LIFT TAKES PLACE AGAIN ALONG AND IN
ADVANCE OF THE STRONG COLD FRONT TO MOVE THROUGH SATURDAY. GFS BUFR
SOUNDINGS SHOW THE LOW-LEVELS REMAINING FAIRLY SATURATED ACROSS
CENTRAL NORTH CAROLINA...AS 850MB WINDS START TO INCREASE OVERNIGHT.
WHILE 850MB THETA-E VALUES INCREASE STEADILY TODAY INTO THIS
EVENING...THE GFS DOES FORECAST A PERIOD OF DECREASING 850MB THETA-E
LATE TONIGHT INTO EARLY SATURDAY MORNING. IT IS IN THIS SAME PERIOD
WHERE THE STATISTICAL GUIDANCE SHOWS A SHORT DIMINISHING TREND IN
CHANCES FOR RAIN...AND THE CONSENSUS OF WRF GUIDANCE NOTES LESSER
COVERAGE OF PRECIPITATION. THE CURRENT THINKING IS THAT SCATTERED TO
NUMEROUS AREAS OF RAIN AND DRIZZLE THROUGH THE EVENING AND INTO THE
OVERNIGHT HOURS MAY BECOME MORE ISOLATED TO SCATTERED LATE
TONIGHT...POSSIBLY INCREASING AGAIN TOWARD THE YADKIN RIVER VERY
LATE TONIGHT INTO EARLY SATURDAY IN GOOD ISENTROPIC LIFT ON THE 295K
AND 300K SURFACES. OVERNIGHT LOWS MAY OCCUR EARLY BEFORE
TEMPERATURES SLOWLY INCREASE DURING THE NIGHT. ONCE AGAIN WILL LEAN
TOWARD A BLEND OF THE GUIDANCE IN THE TRIAD WHERE THERE IS THE
LARGEST DISCREPANCY BETWEEN THE MAV AND THE MET...AND RIGHT NOW
MAINLY ON THE COOLER SIDE ELSEWHERE THOUGH...AS NOTED...READINGS
SHOULD GRADUALLY RISE OVERNIGHT.
SATURDAY INTO SATURDAY NIGHT...PRECIPITATION CHANCES INCREASE
SOLIDLY WITH THE APPROACH AND PASSAGE OF THE FRONT. HEIGHT FALLS
ALOFT SHOULD BE STRONG AS WELL AS THE MID-LEVEL TROUGH APPROACHES
FROM THE WEST LATE IN THE DAY SATURDAY. INSTABILITY IS NOT GREAT
BASED ON THE MODEL SOUNDING LAPSE RATES AND THE MIXED-LAYER CAPE
FORECAST ON THE GFS IN THE LOWEST KM. IN FACT...THE MLCAPE REGISTERS
ONLY TOWARD THE FAR SOUTHEAST...FROM ABOUT KMEB TO KGSB OR SO...
WITH VALUES OF 500J/KG OR LESS. INTERESTINGLY...THOUGH...DOWNDRAFT
CAPE INCREASES NOTICABLY ALONG AND NORTH OF U.S. 64 DURING THE
AFTERNOON TO VALUES AROUND 700J/KG. EVEN THOUGH THE GFS BUFR
SOUNDINGS SHOW THE MIXED LAYER TO BE FAIRLY SHALLOW SATURDAY
AFTERNOON...WHERE THERE IS EVEN A BIT OF INSTABILITY...WINDS ALOFT
INCREASE RAPIDLY TO 40 TO 50KT. THUNDER...OVERALL...MAY BE SOMEWHAT
DIFFICULT TO COME BY...BUT GIVEN THE 40 TO 50KT 925MB WINDS IN THE
AFTERNOON...AND 60 TO 70KT AT 850MB ALONG WITH GOOD THICKNESS
PACKING AS THE FRONT MOVES THROUGH...A STRONGLY-FORCED LINE OF
SHOWERS COULD TAKE PLACE RESULTING IN GUSTY WINDS. WILL NOTE THE
POTENTIAL FOR STRONG TO SEVERE CONDITIONS IN THE HWO FOR SATURDAY...
MAINLY IN THE AFTERNOON AND...FOR THE MOST PART...EAST OF THE FAR
WESTERN PIEDMONT. MAV GUIDANCE FOR HIGHS SATURDAY ARE WARM...AND AT
KRDU ARE ONLY A COUPLE OF DEGREES SHY OF THE RECORD. FOR NOTE...
HIGH TEMPERATURE RECORDS ARE 73 AT KGSO IN 1949...AND 73 AT KRDU AND
79 AT KFAY IN 1930. ONCE AGAIN...WILL CURRENTLY PLAN A FORECAST WITH
A BLEND OF THE MAV AND MET MOS.
DRYING TAKES PLACE SATURDAY NIGHT AND THE CHANCES FOR PRECIPITATION
DIMINISH WEST TO EAST AS K INDICES GO MOSTLY NEGATIVE BY 12Z SUNDAY.
GUSTY WINDS IN THE EVENING DIMINISH SOME OVERNIGHT...AND THE
APPROACH OF THE STRONG TROUGH ALOFT COULD LINGER CLOUDS AND SOME
RAIN CHANCES THROUGH THE EVENING...AND INTO THE EARLY PART OF THE
OVERNIGHT HOURS EAST OF U.S. 1. OVERNIGHT LOWS AROUND 40 TO THE MID
40S.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 305 AM FRIDAY...
THE LONG WAVE TROUGH AXIS WILL BE EXITING THE EAST COAST EARLY
SUNDAY...WITH INCREASING HEIGHTS ACROSS OUR REGION THROUGH THE DAY.
AT THE SURFACE...A HIGH PRESSURE CENTER WILL QUICKLY MOVE FROM THE
NORTHERN GULF COAST AT 12Z SUNDAY TO A POSITION OFF THE SE COAST BY
00Z MONDAY. FOR OUR SENSIBLE WEATHER...SUBSIDENCE AND SUBSEQUENT
DRYING WILL YIELD MOSTLY SUNNY SKIES DURING THE DAY. LOW LEVEL
THICKNESSES...WHILE EXPECTED TO BOTTOM OUT AROUND 1305M EARLY IN THE
DAY BEHIND THE DEPARTING TROUGH...WILL INCREASE TO AROUND 1330M BY
LATE AFTERNOON. THUS LOOK FOR HIGHS TO RANGE FROM THE MID 50S NW TO
LOWER 60S SE. SUNDAY NIGHT...THE MID/UPR RIDGE AXIS WILL BE TO OUR
EAST AND THE NEXT TROUGH WILL BE MOVING ACROSS THE PLAINS.
INCREASING SW FLOW ALOFT WILL RESULT IN THICKENING MID/HI CLOUDS
ACROSS OUR AREA. LOWS IN THE MID-UPR 30S.
MONDAY WILL SEE INCREASING CLOUDS AHEAD OF THE AFOREMENTIONED
TROUGH...WHICH WILL BE CROSSING THE MISS RIVER VALLEY BY 00Z
TUESDAY. HIGHS WILL CLIMB WELL ABOVE NORMAL IN THE PRE-FRONTAL
AIRMASS. HIGHS IN THE LOWER 60S. THEN...SUBSTANTIAL DIFFERENCES
CONTINUE IN THE LATEST GFS AND ECMWF RUNS REGARDING THE TIMING AND
STRENGTH OF THE PROGRESSIVE BUT DAMPENING SHORT WAVE PROGGED TO LIFT
NE AND ACROSS OUR AREA MONDAY NIGHT (PER GFS) OR LATE MONDAY NIGHT
AND DURING THE DAY TUESDAY (PER ECMWF). THE ECMWF IS THE WETTER OF
THE TWO THANKS TO ITS STRONGER SHORT WAVE AND MUCH-STRONGER
(COMPARED TO GFS) LOW LEVEL JET AND MOISTURE TRANSPORT...THUS
SHOWING AROUND 1/2 INCH QPF. IF THE TRENDS GO THE ECMWF WAY WITH
FUTURE RUNS...WILL ALSO NEED TO KEEP A CLOSE EYE ON THERMAL PROFILES
AND THE POTENTIAL FOR CONVECTION ON TUESDAY ALONG AND AHEAD OF THE
COLD FRONT.
BY LATE TUESDAY...THE COLD FRONT WILL BE TO OUR EAST...WITH
SUBSIDENCE...CAA...AND DRYING IN IT`S WAKE. WE`LL THEN TURN OUR
ATTENTION TO THE NEXT SHORT WAVE PROGGED TO DROP SE ACROSS THE
MIDWEST AND OH VALLEY TUESDAY NIGHT. THE GFS AND ECMWF ARE IN DECENT
AGREEMENT EARLY WITH THIS SYSTEM WHILE IT`S UPSTREAM OF US...BUT
THEN START TO DIFFER QUITE DRAMATICALLY AS THE WAVE BOTTOMS OUT
ACROSS THE CAROLINAS. THE ECMWF IS MUCH SLOWER AND CLOSES OFF THE
MID LEVEL WAVE AS IT CROSSES THE CAROLINAS AND RESULTS IN SFC
CYCLOGENESIS JUST OFF THE COAST. THE GFS ON THE OTHER HAND IS MUCH
FASTER WITH AN OPEN WAVE THAT QUICKLY MOVES ACROSS AND EXITS OUR
AREA. WHILE FORECAST SOUNDINGS AND PARTIAL THICKNESSES FROM BOTH
SUGGEST THAT THE AIRMASS WILL LIKELY BE COLD ENOUGH FOR A MIX OF
RAIN/SNOW OR ALL SNOW...BOTH SOLUTIONS ARE RATHER MOISTURE-STARVED
WITH NO GULF AND VERY LITTLE ATLANTIC MOISTURE...UNTIL THE SYSTEM IS
TO OUR EAST. SO FOR NOW...WILL KEEP POPS WITH THIS SYSTEM LIMITED TO
CLIMO VALUES. THIS NW FLOW SYSTEM APPEARS TO BE THE LOWER-IMPACT
TYPE THAT RESULTS IN PERHAPS A FEW FLURRIES...OR PERHAPS A BRIEF
SNOW SHOWER OR TWO...WHICH WOULD OCCUR LATE WEDNESDAY OR WEDNESDAY
NIGHT.
THEN FOR THE LATTER HALF OF THE WEEK...THURSDAY LOOKS DRY WITH A
SHORTWAVE RIDGE CROSSING THE AREA...THEN ANOTHER MOISTURE-STARVED
SHORTWAVE TROUGH IS PROGGED TO MOVE ACROSS UNEVENTFULLY BY WEEKS
END. MEX TEMPS LOOK TOO HIGH FOR THE LATTER HALF OF NEXT WEEK GIVEN
LOW LEVEL THICKNESSES...THUS WILL MAKE APPROPRIATE DOWNWARD
ADJUSTMENTS...TEMPS NEAR OR SLIGHTLY BELOW NORMAL DURING THIS TIME.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 105 AM FRIDAY...
GRADUALLY DIMINISHING CONDITIONS WILL OCCUR IN CENTRAL NORTH
CAROLINA DURING THE 06Z VALID TAF PERIOD. ALREADY...NUMEROUS AREAS
OF RAIN WERE DEVELOPING OVER THE UPSTATE OF SOUTH CAROLINA MOVING
INTO NORTH CAROLINA...WHERE CEILINGS WERE FALLING INTO THE MVFR
RANGE. AS RAIN OCCURS...ANTICIPATE CEILINGS LOWERING TO MVFR...THEN
AS MOISTURE CONTINUES TO INCREASE ALL MODELS SUPPORT CEILINGS
FALLING TO IFR OR LIFR. RAIN SHOULD OCCUR LATEST TOWARD KRWI...AND
ANTICIPATE AREAS OF LIGHT RAIN AND/OR DRIZZLE CONTINUING FROM LATE
TODAY THROUGH THE EVENING. WINDS VEER ALOFT BUT THE LATEST GUIDANCE
SUGGESTS WIND SPEEDS MORE GRADUALLY INCREASE THROUGH AND ABOVE
2000FT. AS A RESULT...HAVE KEPT LLWS OUT OF THE TAFS FOR THE 06Z
ISSUANCE.
BEYOND THE 06Z VALID TAF PERIOD...CONCERNS FOR LLWS INCREASE...
THOUGH THE SURFACE WINDS MAY ALSO INCREASE ENOUGH LATE TONIGHT AND
INTO SATURDAY TO KEEP LLWS ON THE MARGINS AS THE SURFACE WINDS VEER.
WIDESPREAD SUB-VFR CONDITIONS...MANY AREAS IFR OR LIFR...CONTINUE
INTO SATURDAY...AHEAD OF A STRONG COLD FRONT THAT SWEEPS ACROSS
CENTRAL NORTH CAROLINA. WHILE AN ISOLATED THUNDERSTORM COULD OCCUR
SATURDAY IN CENTRAL NORTH CAROLINA...A BAND OF SHOWERS PRODUCING
GUSTY WESTERLY WINDS MOVING ACROSS CENTRAL NORTH CAROLINA DURING THE
AFTERNOON AND VERY EARLY EVENING COULD CERTAINLY POSE AN AVIATION
CONCERN. AVIATION INTERESTS OPERATING SATURDAY SHOULD MONITOR THE
LATEST CONVECTIVE AVIATION INFORMATION AND THE TIMING OF ANY SUCH
BAND. CONDITIONS RAPIDLY BECOME VFR SATURDAY NIGHT CONTINUING INTO
MONDAY. A PERIOD OR TWO OF MVFR CONDITIONS IS POSSIBLE IN LIGHT
PRECIPITATION LATE MONDAY NIGHT INTO TUESDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...DJF
SHORT TERM...DJF
LONG TERM...NP
AVIATION...DJF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
106 AM EST FRI JAN 10 2014
.SYNOPSIS...MOISTURE INCREASES OVER THE REGION TODAY AS HIGH
PRESSURE MOVES EAST INTO THE ATLANTIC. A STRONG COLD FRONT SWEEPS
ACROSS THE REGION SATURDAY. HIGH PRESSURE BUILDS BACK IN ON SUNDAY.
&&
.NEAR TERM /TONIGHT THROUGH FRIDAY NIGHT/...
AS OF 930 PM THURSDAY...
TONIGHT:
A DETERIORATING SHORTWAVE MOVING THROUGH THE OHIO VALLEY HAS
STRENGTHENED THE PRESSURE GRADIENT BETWEEN ITSELF AND THE SURFACE
HIGH OVER THE MID-ATLANTIC. STRONG WARM AIR ADVECTION...EASILY
DEPICTED BY A VERY LARGE WARM NOSE AT 925 MB HAS CONTINUED TO CHARGE
NORTHWARD THIS EVENING AND WILL CONTINUE TO DO SO OVERNIGHT. THIS
WILL HELP TO LIMIT THE THREAT OF ANY FREEZING RAIN IN THE TRIAD
OVERNIGHT. CURRENT RUN OF THE RAP MODEL HAS TEMPERATURES ONLY DOWN
TO ABOUT 39 DEGREES OR SO IN THE TRIAD AND 37 IN ROXBORO BEFORE THE
ONSET OF PRECIPITATION AND THE 00Z RUN OF THE NAM HAS ABOUT 35
DEGREES AND BOTH MODELS HAVE WETBULB TEMPERATURES AT ABOUT THE SAME.
AS FAR AS OBSERVATIONS ARE CONCERNED AS OF 2Z KINT WAS RUNNING AT 42
DEGREES WITH A DEWPOINT OF 14 BUT DEWPOINTS JUST A COUNTY SOUTHWARD
IN THE MID 20S WHICH WILL BE ADVECTING NORTHWARDS OVER THE NEXT
COUPLE OF HOURS. AT THIS POINT HAVE DECIDED AGAINST AN ADVISORY FOR
FREEZING WITH FAIRLY HIGH CONFIDENCE THAT NONE WILL OCCUR AND EVEN
IF SO...IMPACTS WOULD BE VERY MINIMAL TO NONE AT ALL. WILL ADJUST
MINIMUM TEMPERATURES UPWARDS WITH NEXT UPDATE...MID TO UPPER 30S
ACROSS THE AREA.
ALTHOUGH FREEZING PRECIPITATION IS NOT EXPECTED...STRONG ISENTROPIC
LIFT AND THE ADVECTION OF WARM MOIST LOW LEVEL AIR WILL BRING
PRECIPITATION MAINLY TO THE WESTERN PIEDMONT WITH THE RAP SHOWING
FIRST ACCUMULATIONS IN THE SW AFTER 6Z AND SPREADING UP INTO THE
TRIAD BY 8 OR 9Z. CURRENT RADAR SHOWS OUR FIRST RETURNS OF THE NIGHT
BUT THIS IS IN ALL LIKELIHOOD NOT YET REACHING THE GROUND. IN
GENERAL THE EAST WILL BE DRY COMPARED TO THE WEST BUT CANNOT RULE
OUT LIGHT RAIN EVEN IN EASTERN LOCALS BY DAYBREAK. -ELLIS
FRIDAY AND FRIDAY NIGHT:
THE BEST SURGE OF ISENTROPIC LIFT LOOKS TO
MAXIMIZE ACROSS THE AREA BY LATE MORNING BEFORE LIFTING OFF TO THE
NORTH...WITH CONTINUED BROAD WAA THROUGH THE REMAINDER OF THE DAY.
SO WE COULD BE LOOKING AT A LULL IN MEASURABLE PRECIP BY NOON WITH
MORE IN THE WAY OF DRIZZLE THROUGH THE AFTERNOON AND
EVENING...ESPECIALLY IN THE EAST REMOVED FROM THE HEART OF THE
DAMMING AIRMASS AND BETTER FGEN GRADIENT ACROSS THE WESTERN
PIEDMONT.
TEMPERATURES: WILL SEE THE TYPICAL SHARP NW-SE TEMPERATURE GRADIENT
ASSOCIATED WITH CAD EVENTS...RANGING FROM MID TO UPPER 30S IN THE
TRIAD TO MID AND UPPER 50S IN THE FAR SE COASTAL PLAIN. MODELS
INDICATE WEDGE WILL ERODE OVERNIGHT FRIDAY NIGHT WITH LOW TEMPS SAT
MORNING LIKELY OCCURRING AT MIDNIGHT WITH RISING TEMPS THEREAFTER.
WILL INDICATE TEMPS RISING INTO THE MID/UPPER 50S TO LOWER 60S
ALONG/EAST OF HWY 1 (WARMEST SE COASTAL PLAIN) TO MID/UPPER 40S IN
THE TRIAD. -CBL
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 225 PM THURSDAY...
FOR SAT/SAT NIGHT: A WET AND POTENTIALLY STORMY DAY. THE WARM
FRONTAL ZONE WILL LIKELY STILL BE SITUATED SE OF THE TRIAD AT
DAYBREAK BUT WE SHOULD BE FULLY IN THE WARM SECTOR BY AROUND 18Z SAT
AS THE WARM FRONTAL MOMENTUM SHOULD EASILY OVERTAKE THE THINNING
STABLE POOL. (THE GFS IS A FEW HOURS SLOWER THAN THE NAM WITH ITS
WARM FRONTAL PASSAGE.) DEEP MID LEVEL TROUGHING THROUGH THE CENTRAL
CONUS WILL SHIFT EASTWARD THROUGH THE EASTERN CONUS SAT/SAT NIGHT...
WITH SURFACE COLD FRONT PASSAGE THROUGH NC SAT AFTERNOON AND
EVENING. CERTAINTY IS HIGH THAT WE`LL SEE WIDESPREAD SHOWERS AHEAD
OF THIS FRONT GIVEN THE SURGE IN MOISTURE WITH A STRONG GULF FEED
AND INCOMING PW VALUES OF 1.3-1.7. VIGOROUS DYNAMIC FORCING WILL
CONTRIBUTE TO ASCENT WITH STRENGTHENING UPPER LEVEL DIVERGENCE AND
MID LEVEL DPVA... 500 MB WINDS OVER 500 MB... 12-HR HEIGHT FALLS OF
180-240 METERS... AND AN 850 MB JET FROM THE SW INTENSIFYING TO 50-
60 KTS. THESE POTENT DYNAMICS APPEAR TO MAXIMIZE OVER NC AROUND 18Z
(GIVE OR TAKE AN HOUR OR TWO)... WHEN WE ALSO SEE RISING MODEL
FORECAST INSTABILITY... WITH THE NAM DEPICTING 400-800 J/KG OF
SURFACE CAPE ALONG/EAST OF HIGHWAY 1. LOW LEVEL SHEAR RAMPS UP EARLY
SAT AS WELL... WITH 0-1 KM SHEAR TOPPING OUT AT 45-50 KTS (HIGHEST
IN THE PIEDMONT) SAT AFTERNOON... AND LOW LCLS. ALL OF THIS EQUATES
TO A RISK OF STRONG FAST-MOVING BOWING SEGMENTS AND PERHAPS A
SUPERCELL OR TWO... PROVIDED THE PREDICTED INSTABILITY CAN BE
REALIZED AND WE DO INDEED SEE SURFACE DEW POINTS IN THE 60S AS
MODELS GENERALLY AGREE WILL HAPPEN. THE ONE CAVEAT IS THE
POSSIBILITY OF MORNING SHOWERS PRECEDING THE PRIMARY BAND OF
SHOWERS... AS THIS MAY TEMPER INSTABILITY ESPECIALLY IN THE WRN HALF
OF THE CWA WHERE THE LOW LEVEL SHEAR WILL BE STRONGEST. WILL ADD A
MENTION OF THUNDER SAT... ESPECIALLY EAST... AND ADD A MENTION OF
POSSIBLE STRONG STORMS TO THE HAZARDOUS WEATHER OUTLOOK. EXPECT
MOSTLY CLOUDY TO CLOUDY SKIES THROUGH THE DAY... QUITE WINDY WITH
SUSTAINED WINDS OF 15-20 MPH GUSTING TO 35 MPH (AND OCCASIONALLY
HIGHER)... AND CATEGORICAL POPS. BASED ON MODEL GUIDANCE AND SREF
PROBABILITIES... RAINFALL AMOUNTS ARE EXPECTED TO REACH AROUND 1.0-
1.25 INCHES FOR THE ENTIRE EVENT. EXPECT A SLOWER TEMP RISE IN THE
TRIAD UNTIL THE VERY SHALLOW SURFACE-BASED STABLE POOL IS ERODED
THERE... BUT OVERALL IT SHOULD BE A MILD DAY WITH HIGHS FROM THE LOW
60S NW TO LOW 70S SE. BOTH THE NAM AND GFS INDICATE CLEARING SKIES
SAT NIGHT ALTHOUGH THE GFS IS MUCH FASTER WITH DEEP DRYING TAKING
PLACE WHILE THE NAM IS SLOWER AND HOLDS ONTO PLENTY OF MOISTURE
BELOW 600 MB WELL INTO THE EVENING. THE NAM ALSO STAYS WELL-MIXED
FOR SEVERAL HOURS JUST BEHIND THE COLD FRONT AS THE 925-700 MB LAYER
COOLS WITH THE DELAY IN SURFACE COOLING... AND THIS WOULD SUGGEST A
FEW SHALLOW SHOWERS BEHIND THE FRONT. BUT IN EITHER CASE WE SHOULD
SEE CLEARING AFTER MIDNIGHT WITH DEEP DRYING. WITH THE MIXING
HOLDING THROUGH THE NIGHT... EXPECT WINDS TO STAY UP... AND THIS
STIRRING WILL SOMEWHAT OFFSET THE COLD AIR ADVECTION AND HINDER THE
DROP IN TEMPS. LOWS 40-49.
FOR SUN/SUN NIGHT: MODELS INDICATE IMPRESSIVE HEIGHT RISES OF 220-
260 M BEHIND THE TROUGH AND STRONG MID LEVEL SUBSIDENCE AND WARMING
STARTING IN THE PREDAWN HOURS SUNDAY. EXPECT CLEAR SKIES WITH
MODIFIED SURFACE HIGH PRESSURE BUILDING IN FROM THE SW. THICKNESSES
WILL HAVE COOLED MARKEDLY FROM SATURDAY BUT ARE STILL LIKELY TO BE
ABOUT 5-10 M ABOVE NORMAL... EQUATING TO HIGHS OF 53-62... A TAD
UNDER STATISTICAL GUIDANCE. THE SURFACE HIGH SHIFTS QUICKLY OFF THE
SE COAST SUN NIGHT WITHIN A PROGRESSIVE LONGWAVE PATTERN ACROSS THE
CONUS. AS OUR NEXT LONGWAVE TROUGH SHIFTS THROUGH THE CENTRAL STATES
SUN NIGHT WITH A SHOT OF SOUTHERN STREAM ENERGY MOVING IN FROM THE
SW... WE`LL SEE INCREASING SOUTHWEST FLOW ALOFT OVER NC RESULTING IN
INCREASING AND THICKENING HIGH CLOUDS OVERNIGHT. LOWS 34-40. -GIH
&&
.LONG TERM /MONDAY THROUGH THURSDAY...
AS OF 245 PM THURSDAY...
CHALLENGING FORECAST FOR THE EARLY TO MIDDLE PART OF NEXT WEEK AS
SOME MODEL DISAGREEMENT EMERGES. THE LONGWAVE TROUGH OVER THE
CENTRAL US EARLY MONDAY MORNING PROGRESSES EASTWARD THROUGH MON
NIGHT WITH ENERGY DIGGING INTO THE TROUGH BASE... MUCH MORE DEEPLY
OVER THE DEEP SOUTH ON THE ECMWF THAN THE GFS. AS A RESULT... THE
ECMWF PULLS THE OLD FRONTAL ZONE TO OUR SOUTH WELL TO THE NNW AND
BACK INTO NC AS A WARM FRONT BY LATE MON NIGHT... WITH A STRONG
SURFACE CYCLONE MOVING NE THROUGH NC TUE MORNING. MEANWHILE... THE
WEAKER AND FASTER GFS BRINGS THE FRONTAL ZONE BACK NW ONLY TO THE
COASTAL CAROLINAS WITH A COLD FRONT (AND NO STRONG CYCLONE) SHIFTING
THROUGH NC MON NIGHT. TOUGH TO PICK OUT A WINNER BETWEEN THESE TWO
CAMPS... PARTICULARLY CONSIDERING THAT BOTH HAVE VARYING DEGREES OF
POLAR STREAM ENERGY DIVING IN THE BACK SIDE OF THE LONGWAVE TROUGH
EARLY TUE... WHICH SERVES TO DEEPEN THE TROUGH OVER THE EASTERN
CONUS WED/THU. GIVEN THE UNCERTAINTY... WILL AVOID FORECASTING ANY
EXTREMES... AND STICK WITH A CHANCE OF RAIN STARTING WITH THE
APPROACH OF THE FRONT MON NIGHT... LASTING INTO TUE EVENING. BOTH
THE GFS AND ECMWF SWING THE TROUGH BASE THROUGH NC WED WITH AT LEAST
SOME CLOUDINESS AND POTENTIALLY SOME PRECIP AS WELL. THESE
DETERMINISTIC MODELS SUGGEST THAT IT COULD BE A QUICK SHOT OF LIGHT
MIXED RAIN/SNOW BASED ON FORECAST PARTIAL THICKNESSES... HOWEVER
GIVEN THAT WE COULD HAVE SUBSTANTIAL DOWNSLOPE FLOW COMPONENT
ESPECIALLY WITH A WEAKER SYSTEM... WILL PUT IN CLOUDS FOR NOW BUT
HOLD OFF ON ANY PRECIP CHANCES ON WED. CLEARING BY THU WITH SOUTHERN
STREAM HIGH PRESSURE BUILDING INTO THE SOUTHEAST. WILL KEEP TEMPS
WITHIN A CATEGORY OF CLIMATOLOGY THROUGHOUT THIS PERIOD... BUT
CONFIDENCE IS NOT HIGH... AS A MUCH STRONGER OR WEAKER SYSTEM COULD
HAVE LARGE EFFECTS ON TEMPS. -GIH
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 105 AM FRIDAY...
GRADUALLY DIMINISHING CONDITIONS WILL OCCUR IN CENTRAL NORTH
CAROLINA DURING THE 06Z VALID TAF PERIOD. ALREADY...NUMEROUS AREAS
OF RAIN WERE DEVELOPING OVER THE UPSTATE OF SOUTH CAROLINA MOVING
INTO NORTH CAROLINA...WHERE CEILINGS WERE FALLING INTO THE MVFR
RANGE. AS RAIN OCCURS...ANTICIPATE CEILINGS LOWERING TO MVFR...THEN
AS MOISTURE CONTINUES TO INCREASE ALL MODELS SUPPORT CEILINGS
FALLING TO IFR OR LIFR. RAIN SHOULD OCCUR LATEST TOWARD KRWI...AND
ANTICIPATE AREAS OF LIGHT RAIN AND/OR DRIZZLE CONTINUING FROM LATE
TODAY THROUGH THE EVENING. WINDS VEER ALOFT BUT THE LATEST GUIDANCE
SUGGESTS WIND SPEEDS MORE GRADUALLY INCREASE THROUGH AND ABOVE
2000FT. AS A RESULT...HAVE KEPT LLWS OUT OF THE TAFS FOR THE 06Z
ISSUANCE.
BEYOND THE 06Z VALID TAF PERIOD...CONCERNS FOR LLWS INCREASE...
THOUGH THE SURFACE WINDS MAY ALSO INCREASE ENOUGH LATE TONIGHT AND
INTO SATURDAY TO KEEP LLWS ON THE MARGINS AS THE SURFACE WINDS VEER.
WIDESPREAD SUB-VFR CONDITIONS...MANY AREAS IFR OR LIFR...CONTINUE
INTO SATURDAY...AHEAD OF A STRONG COLD FRONT THAT SWEEPS ACROSS
CENTRAL NORTH CAROLINA. WHILE AN ISOLATED THUNDERSTORM COULD OCCUR
SATURDAY IN CENTRAL NORTH CAROLINA...A BAND OF SHOWERS PRODUCING
GUSTY WESTERLY WINDS MOVING ACROSS CENTRAL NORTH CAROLINA DURING THE
AFTERNOON AND VERY EARLY EVENING COULD CERTAINLY POSE AN AVIATION
CONCERN. AVIATION INTERESTS OPERATING SATURDAY SHOULD MONITOR THE
LATEST CONVECTIVE AVIATION INFORMATION AND THE TIMING OF ANY SUCH
BAND. CONDITIONS RAPIDLY BECOME VFR SATURDAY NIGHT CONTINUING INTO
MONDAY. A PERIOD OR TWO OF MVFR CONDITIONS IS POSSIBLE IN LIGHT
PRECIPITATION LATE MONDAY NIGHT INTO TUESDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...ELLIS/CBL
SHORT TERM...HARTFIELD
LONG TERM...HARTFIELD
AVIATION...DJF
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
540 PM EST FRI JAN 10 2014
.SYNOPSIS...
AN APPROACHING UPPER LEVEL TROUGH WILL MOVE INTO THE AREA
TONIGHT...WITH RAIN EXPECTED TONIGHT AND INTO SATURDAY. A COLD FRONT WILL
CROSS THE REGION BY SATURDAY AFTERNOON...LOWERING TEMPERATURES
THROUGH SUNDAY. HIGH PRESSURE WILL ENTER THE SOUTHEASTERN STATES
ON SUNDAY...WITH RIDGING BRINGING FAIR CONDITIONS TO THE OHIO
VALLEY THROUGH EARLY MONDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
A QUICK UPDATE HAS BEEN PRODUCED TO ALLOW FOR THE ISSUANCE OF A
DENSE FOG ADVISORY. THE AREA OF DENSE FOG HAS CONTINUED TO EXPAND
NORTHWARD...ENVELOPING LARGE ENOUGH SECTIONS OF SEVERAL COUNTIES
TO REQUIRE AN ADVISORY TO BE ISSUED. THE SOUTHERN EDGE OF THIS
ADVISORY WILL LIKELY BE ABLE TO BE DROPPED EARLY...AS VISIBILITIES
ARE VERY GRADUALLY IMPROVING FROM THE SOUTH. HOWEVER...THE NEWEST
HIGH-RESOLUTION MODEL DATA INDICATES THAT SURFACE SATURATION IS
LIKELY TO CONTINUE IN THE NORTHWESTERN CWA FOR AT LEAST SEVERAL
MORE HOURS.
PREVIOUS DISCUSSION >
THE PRIMARY WEATHER CONCERN FOR THE NEAR TERM IS FOG POTENTIAL. A
NARROW AXIS FROM THE WEST-CENTRAL CWA (AROUND FRANKLIN COUNTY
INDIANA) THROUGH THE NORTHEAST CWA (DELAWARE COUNTY OHIO) CONTAINS
A FEW OBSERVATION SITES REPORTING QUARTER-MILE DENSE FOG. RH
PROJECTIONS AND SREF/HRRR/RAP VISIBILITY PRODUCTS ALL INDICATE A
POTENTIAL FOR THIS TO CONTINUE TONIGHT...WITH THE LOWER
VISIBILITIES GRADUALLY SHIFTING NORTH AND WEST WITH TIME. FOR NOW
THIS THREAT WILL BE COVERED BY THE HWO AND A NEW SPECIAL WEATHER
STATEMENT...BUT IF THE DENSE AREA EXPANDS AT ALL...AN ADVISORY MAY
BECOME NECESSARY. RIGHT NOW...THIS AREA IS FAIRLY NARROW AND NOT
WIDESPREAD ENOUGH TO REQUIRE A HEADLINE.
INCREASING ISENTROPIC LIFT AHEAD OF A DEEPENING MID-LEVEL TROUGH
WILL GRADUALLY LEAD TO AN INCREASE IN PRECIPITATION POTENTIAL THIS
EVENING...PRIMARILY FOR THE WESTERN HALF OF THE CWA. DESPITE THE
RELATIVELY ABUNDANT LOW-LEVEL MOISTURE...IT IS NOT APPARENT THAT
CURRENT ECHOES IN THE SOUTHWEST CWA ARE REACHING THE GROUND...SO
MEASURABLE PRECIPITATION MAY STILL BE A FEW HOURS OFF. MOST OF THE
IMPACTS FROM THE APPROACHING TROUGH AND COLD FRONT WILL BE COVERED
IN THE SHORT TERM DISCUSSION.
TEMPERATURES OVERNIGHT ARE EXPECTED TO REMAIN RELATIVELY STEADY
FOR A WHILE...BEFORE RISING (ESPECIALLY IN THE SOUTHERN CWA)
CLOSER TO DAYBREAK. THE RAP WAS USED AS A BASIS FOR THESE
NON-DIURNAL TEMPERATURES...AS IT IS HANDLING THE CURRENT SITUATION
WELL.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AHEAD OF A MID-LEVEL TROUGH MOVING EAST OUT OF THE MISSISSIPPI
VALLEY...A SURFACE LOW WILL TRACK NORTHEASTWARD INTO THE GREAT
LAKES REGION ON SATURDAY. THIS WILL BRING A COLD FRONT THROUGH THE
OHIO VALLEY BY SATURDAY AFTERNOON.
AHEAD OF THE COLD FRONT...THE OHIO VALLEY WILL BE WITHIN A REGIME
OF DEEP SOUTHERLY FLOW...ADVECTING A VERY MOIST AIR MASS INTO THE
REGION. BY EARLY SATURDAY MORNING...PRECIPITABLE WATER VALUES WILL
BE WELL OVER AN INCH ACROSS THE ILN CWA...EXCEEDING 300 PERCENT OF
NORMAL FOR JANUARY. THE STRONGEST PUSH OF MOISTURE WILL COME ON
THE NOSE OF A LOW LEVEL JET BETWEEN 08Z AND 12Z...FOCUSED
PRIMARILY ON THE SOUTHERN AND SOUTHEASTERN SECTIONS OF THE ILN
CWA. WITH SOUNDINGS APPEARING MOIST ADIABATIC (AS WOULD BE
EXPECTED)...INSTABILITY WILL BE HARD TO COME BY. THERE APPEARS TO
BE JUST ENOUGH CONDITIONAL ELEVATED INSTABILITY TO SUPPORT A
CHANCE OF THUNDER IN THE SOUTH AND SOUTHEAST CWA EARLY SATURDAY
MORNING...AND AT THE VERY LEAST...SOME OF THE SHOWERS WILL LIKELY
BE A LITTLE BIT CONVECTIVE IN NATURE.
THE LARGER-SCALE MODELS INDICATE PRECIPITATION TOTALS OF GENERALLY
JUST UNDER AN INCH...WHILE SOME OF THE MESOSCALE MODELS SHOW AN
AXIS OF OVER AN INCH THAT WORKS THROUGH THE SOUTH-CENTRAL PORTIONS
OF THE ILN CWA. BASED ON THE APPEARANCE OF SIMULATED
REFLECTIVITY ON THE HIGH-RES RUNS...AND THE POTENTIAL FOR SOME
ISOLATED ELEVATED CONVECTIVE ELEMENTS...SOME LOCALIZED
PRECIPITATION AMOUNTS MAY GET AS HIGH AS AN INCH AND A HALF. BASED
ON FLASH FLOOD GUIDANCE AND MMEFS RUNS (USING NAEF/SREF/GEFS
INPUT)...IT DOES NOT APPEAR THAT THIS WILL BE ENOUGH RAIN TO LEAD
TO SIGNIFICANT FLOODING ISSUES. A FEW ACTION STAGE RIVER
READINGS...OR PERHAPS AN ADVISORY OR TWO...MAY NOT BE OUT OF THE
QUESTION.
NON-DIURNAL TEMPERATURE TRENDS ARE BEING CONTINUED THROUGH
SATURDAY...AS COLD FRONTAL PASSAGE OCCURS. DEEP MOISTURE WILL
DISAPPEAR AFTER THE FRONT HAS PASSED...BUT POPS WILL BE MAINTAINED
AS ADDITIONAL RAIN SHOWERS (MIXING WITH SNOW LATE) APPEAR LIKELY.
THIS POST-FRONTAL REGIME (UNDER THE MID-LEVEL TROUGH AXIS) WILL BE
CHARACTERIZED BY A MIXED LAYER WITH WEAK AND SHALLOW
INSTABILITY...AND ABUNDANT LOW- LEVEL MOISTURE. EVENTUALLY...AS
THE NIGHT PROGRESSES...MOISTURE BECOMES SHALLOW ENOUGH THAT ICE
CRYSTALS MAY NOT BE ABLE TO FORM. FLURRIES HAVE BEEN INTRODUCED
THROUGH SATURDAY NIGHT...BUT IT IS VERY POSSIBLE THAT THIS WILL
END UP BEING DRIZZLE (OR EVEN FREEZING DRIZZLE BASED ON SURFACE
TEMPS).
BY SUNDAY MORNING...RIDGING WILL BE ENTERING THE CWA...WITH
SURFACE HIGH PRESSURE BUILDING IN FROM THE SOUTH. THE LOW LEVEL
MOISTURE MAY NOT ALLOW CLOUDS TO SCOUR VERY QUICKLY...BUT MOSTLY
SUNNY SKIES ARE EXPECTED BY AFTERNOON FOR MOST OF THE CWA (WITH
CLOUDS DISSIPATING EARLIER IN THE SOUTH). WITH THE CWA RETURNING
TO A WARM ADVECTION PATTERN...TEMPS WILL RISE AGAIN ON
SUNDAY...AND STRUGGLE TO EVEN CROSS BACK UNDER THE FREEZING MARK
ON SUNDAY NIGHT / EARLY MONDAY MORNING.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
RAIN WILL BE LIKELY MONDAY AS A SURGE OF GULF MOISTURE MOVES UP A
FRONTAL BOUNDARY ON A SOUTHWEST UPPER FLOW. SOME LOCATIONS MAY SEE
AN INCH OF RAIN WITH THIS EVENT. RAIN AND SNOW SHOWERS ARE POSSIBLE
FOR TUESDAY IN THE NORTHWEST FLOW BEHIND THE FRONT.
SNOW SHOWERS MAY LINGER ON WEDNESDAY IN THE COLDER NORTHWEST FLOW. A
PERIOD OF DRY WEATHER IS INDICATED FOR THURSDAY WHEN A RIDGE OF HIGH
PRESSURE IS FORECAST TO PUSH ACROSS THE REGION. SNOW SHOWERS WILL BE
POSSIBLE AGAIN ON FRIDAY DUE TO A TROUGH AND ASSOCIATED MOISTURE AND
COLD ADVECTION.
TEMPERATURES WILL START ABOVE NORMAL MONDAY AND TUESDAY...WITH HIGHS
MAINLY IN THE 40S. COLD ADVECTION WILL PUSH READINGS BELOW NORMAL ON
WEDNESDAY AND FRIDAY WITH HIGHS IN THE 20S...WHILE THE RIDGE WILL
PROVIDE SOME WARM ADVECTION AND NEAR NORMAL 30S FOR THURSDAY.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
ABUNDANT LOW LEVEL MOISTURE SHROUDING ILN/S TAFS IN IFR CIGS AND
IFR/MVFR VSBYS IN FOG NORTH OF E-W ORIENTED WARM FRONT. LOW CLOUDS
AND VSBYS WILL BE SLOW TO IMPROVE THRU THE AFTN.
NEXT MID LEVEL TROF TO SHARPEN UP OVER THE PLAINS WITH MID LEVEL
FLOW BACKING ACRS THE OHIO VALLEY. FAVORABLE ISENTROPIC LIFT WILL
DEVELOP AHD OF THIS SYSTEM DURG THE AFTN. BASED ON LATEST MODEL TRENDS
HAVE VCSH DEVELOPING DURG EARLY EVENING AND THEN PREVAILING RAIN
DEVELOPING BETWEEN 04Z AND 07Z. EXPECT IFR CIGS WITH MVFR VSBYS DURG
RAIN. COLD FRONT EXPECTED TO SWEEP EAST THRU THE TAF SITES DURG EARLY
MORNING SATURDAY. WINDS WILL SHIFT TO THE WEST AND GUST UP TO 26 KTS.
EXPECT MVFR CIGS TO LINGER THRU SATURDAY AFTN.
OUTLOOK...MVFR TO IFR CEILINGS LIKELY THROUGH SATURDAY NIGHT. MVFR
VISIBILITIES POSSIBLE INTO EARLY SATURDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...DENSE FOG ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR OHZ026-034-
035-042>045-051>053-060-061.
KY...NONE.
IN...DENSE FOG ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR INZ050-058-
059.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...HATZOS
SHORT TERM...HATZOS
LONG TERM...CONIGLIO
AVIATION...AR
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
357 PM EST FRI JAN 10 2014
.SYNOPSIS...
AN APPROACHING UPPER LEVEL TROUGH WILL MOVE INTO THE AREA
TONIGHT...WITH RAIN EXPECTED TONIGHT AND INTO SATURDAY. A COLD FRONT WILL
CROSS THE REGION BY SATURDAY AFTERNOON...LOWERING TEMPERATURES
THROUGH SUNDAY. HIGH PRESSURE WILL ENTER THE SOUTHEASTERN STATES
ON SUNDAY...WITH RIDGING BRINGING FAIR CONDITIONS TO THE OHIO
VALLEY THROUGH EARLY MONDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
THE PRIMARY WEATHER CONCERN FOR THE NEAR TERM IS FOG POTENTIAL. A
NARROW AXIS FROM THE WEST-CENTRAL CWA (AROUND FRANKLIN COUNTY
INDIANA) THROUGH THE NORTHEAST CWA (DELAWARE COUNTY OHIO) CONTAINS
A FEW OBSERVATION SITES REPORTING QUARTER-MILE DENSE FOG. RH
PROJECTIONS AND SREF/HRRR/RAP VISIBILITY PRODUCTS ALL INDICATE A
POTENTIAL FOR THIS TO CONTINUE TONIGHT...WITH THE LOWER
VISIBILITIES GRADUALLY SHIFTING NORTH AND WEST WITH TIME. FOR NOW
THIS THREAT WILL BE COVERED BY THE HWO AND A NEW SPECIAL WEATHER
STATEMENT...BUT IF THE DENSE AREA EXPANDS AT ALL...AN ADVISORY MAY
BECOME NECESSARY. RIGHT NOW...THIS AREA IS FAIRLY NARROW AND NOT
WIDESPREAD ENOUGH TO REQUIRE A HEADLINE.
INCREASING ISENTROPIC LIFT AHEAD OF A DEEPENING MID-LEVEL TROUGH
WILL GRADUALLY LEAD TO AN INCREASE IN PRECIPITATION POTENTIAL THIS
EVENING...PRIMARILY FOR THE WESTERN HALF OF THE CWA. DESPITE THE
RELATIVELY ABUNDANT LOW-LEVEL MOISTURE...IT IS NOT APPARENT THAT
CURRENT ECHOES IN THE SOUTHWEST CWA ARE REACHING THE GROUND...SO
MEASURABLE PRECIPITATION MAY STILL BE A FEW HOURS OFF. MOST OF THE
IMPACTS FROM THE APPROACHING TROUGH AND COLD FRONT WILL BE COVERED
IN THE SHORT TERM DISCUSSION.
TEMPERATURES OVERNIGHT ARE EXPECTED TO REMAIN RELATIVELY STEADY
FOR A WHILE...BEFORE RISING (ESPECIALLY IN THE SOUTHERN CWA)
CLOSER TO DAYBREAK. THE RAP WAS USED AS A BASIS FOR THESE
NON-DIURNAL TEMPERATURES...AS IT IS HANDLING THE CURRENT SITUATION
WELL.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AHEAD OF A MID-LEVEL TROUGH MOVING EAST OUT OF THE MISSISSIPPI
VALLEY...A SURFACE LOW WILL TRACK NORTHEASTWARD INTO THE GREAT
LAKES REGION ON SATURDAY. THIS WILL BRING A COLD FRONT THROUGH THE
OHIO VALLEY BY SATURDAY AFTERNOON.
AHEAD OF THE COLD FRONT...THE OHIO VALLEY WILL BE WITHIN A REGIME
OF DEEP SOUTHERLY FLOW...ADVECTING A VERY MOIST AIR MASS INTO THE
REGION. BY EARLY SATURDAY MORNING...PRECIPITABLE WATER VALUES WILL
BE WELL OVER AN INCH ACROSS THE ILN CWA...EXCEEDING 300 PERCENT OF
NORMAL FOR JANUARY. THE STRONGEST PUSH OF MOISTURE WILL COME ON
THE NOSE OF A LOW LEVEL JET BETWEEN 08Z AND 12Z...FOCUSED
PRIMARILY ON THE SOUTHERN AND SOUTHEASTERN SECTIONS OF THE ILN
CWA. WITH SOUNDINGS APPEARING MOIST ADIABATIC (AS WOULD BE
EXPECTED)...INSTABILITY WILL BE HARD TO COME BY. THERE APPEARS TO
BE JUST ENOUGH CONDITIONAL ELEVATED INSTABILITY TO SUPPORT A
CHANCE OF THUNDER IN THE SOUTH AND SOUTHEAST CWA EARLY SATURDAY
MORNING...AND AT THE VERY LEAST...SOME OF THE SHOWERS WILL LIKELY
BE A LITTLE BIT CONVECTIVE IN NATURE.
THE LARGER-SCALE MODELS INDICATE PRECIPITATION TOTALS OF GENERALLY
JUST UNDER AN INCH...WHILE SOME OF THE MESOSCALE MODELS SHOW AN
AXIS OF OVER AN INCH THAT WORKS THROUGH THE SOUTH-CENTRAL PORTIONS
OF THE ILN CWA. BASED ON THE APPEARANCE OF SIMULATED
REFLECTIVITY ON THE HIGH-RES RUNS...AND THE POTENTIAL FOR SOME
ISOLATED ELEVATED CONVECTIVE ELEMENTS...SOME LOCALIZED
PRECIPITATION AMOUNTS MAY GET AS HIGH AS AN INCH AND A HALF. BASED
ON FLASH FLOOD GUIDANCE AND MMEFS RUNS (USING NAEF/SREF/GEFS
INPUT)...IT DOES NOT APPEAR THAT THIS WILL BE ENOUGH RAIN TO LEAD
TO SIGNIFICANT FLOODING ISSUES. A FEW ACTION STAGE RIVER
READINGS...OR PERHAPS AN ADVISORY OR TWO...MAY NOT BE OUT OF THE
QUESTION.
NON-DIURNAL TEMPERATURE TRENDS ARE BEING CONTINUED THROUGH
SATURDAY...AS COLD FRONTAL PASSAGE OCCURS. DEEP MOISTURE WILL
DISAPPEAR AFTER THE FRONT HAS PASSED...BUT POPS WILL BE MAINTAINED
AS ADDITIONAL RAIN SHOWERS (MIXING WITH SNOW LATE) APPEAR LIKELY.
THIS POST-FRONTAL REGIME (UNDER THE MID-LEVEL TROUGH AXIS) WILL BE
CHARACTERIZED BY A MIXED LAYER WITH WEAK AND SHALLOW
INSTABILITY...AND ABUNDANT LOW- LEVEL MOISTURE. EVENTUALLY...AS
THE NIGHT PROGRESSES...MOISTURE BECOMES SHALLOW ENOUGH THAT ICE
CRYSTALS MAY NOT BE ABLE TO FORM. FLURRIES HAVE BEEN INTRODUCED
THROUGH SATURDAY NIGHT...BUT IT IS VERY POSSIBLE THAT THIS WILL
END UP BEING DRIZZLE (OR EVEN FREEZING DRIZZLE BASED ON SURFACE
TEMPS).
BY SUNDAY MORNING...RIDGING WILL BE ENTERING THE CWA...WITH
SURFACE HIGH PRESSURE BUILDING IN FROM THE SOUTH. THE LOW LEVEL
MOISTURE MAY NOT ALLOW CLOUDS TO SCOUR VERY QUICKLY...BUT MOSTLY
SUNNY SKIES ARE EXPECTED BY AFTERNOON FOR MOST OF THE CWA (WITH
CLOUDS DISSIPATING EARLIER IN THE SOUTH). WITH THE CWA RETURNING
TO A WARM ADVECTION PATTERN...TEMPS WILL RISE AGAIN ON
SUNDAY...AND STRUGGLE TO EVEN CROSS BACK UNDER THE FREEZING MARK
ON SUNDAY NIGHT / EARLY MONDAY MORNING.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
RAIN WILL BE LIKELY MONDAY AS A SURGE OF GULF MOISTURE MOVES UP A
FRONTAL BOUNDARY ON A SOUTHWEST UPPER FLOW. SOME LOCATIONS MAY SEE
AN INCH OF RAIN WITH THIS EVENT. RAIN AND SNOW SHOWERS ARE POSSIBLE
FOR TUESDAY IN THE NORTHWEST FLOW BEHIND THE FRONT.
SNOW SHOWERS MAY LINGER ON WEDNESDAY IN THE COLDER NORTHWEST FLOW. A
PERIOD OF DRY WEATHER IS INDICATED FOR THURSDAY WHEN A RIDGE OF HIGH
PRESSURE IS FORECAST TO PUSH ACROSS THE REGION. SNOW SHOWERS WILL BE
POSSIBLE AGAIN ON FRIDAY DUE TO A TROUGH AND ASSOCIATED MOISTURE AND
COLD ADVECTION.
TEMPERATURES WILL START ABOVE NORMAL MONDAY AND TUESDAY...WITH HIGHS
MAINLY IN THE 40S. COLD ADVECTION WILL PUSH READINGS BELOW NORMAL ON
WEDNESDAY AND FRIDAY WITH HIGHS IN THE 20S...WHILE THE RIDGE WILL
PROVIDE SOME WARM ADVECTION AND NEAR NORMAL 30S FOR THURSDAY.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
ABUNDANT LOW LEVEL MOISTURE SHROUDING ILN/S TAFS IN IFR CIGS AND
IFR/MVFR VSBYS IN FOG NORTH OF E-W ORIENTED WARM FRONT. LOW CLOUDS
AND VSBYS WILL BE SLOW TO IMPROVE THRU THE AFTN.
NEXT MID LEVEL TROF TO SHARPEN UP OVER THE PLAINS WITH MID LEVEL
FLOW BACKING ACRS THE OHIO VALLEY. FAVORABLE ISENTROPIC LIFT WILL
DEVELOP AHD OF THIS SYSTEM DURG THE AFTN. BASED ON LATEST MODEL TRENDS
HAVE VCSH DEVELOPING DURG EARLY EVENING AND THEN PREVAILING RAIN
DEVELOPING BETWEEN 04Z AND 07Z. EXPECT IFR CIGS WITH MVFR VSBYS DURG
RAIN. COLD FRONT EXPECTED TO SWEEP EAST THRU THE TAF SITES DURG EARLY
MORNING SATURDAY. WINDS WILL SHIFT TO THE WEST AND GUST UP TO 26 KTS.
EXPECT MVFR CIGS TO LINGER THRU SATURDAY AFTN.
OUTLOOK...MVFR TO IFR CEILINGS LIKELY THROUGH SATURDAY NIGHT. MVFR
VISIBILITIES POSSIBLE INTO EARLY SATURDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...HATZOS
SHORT TERM...HATZOS
LONG TERM...CONIGLIO
AVIATION...AR
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
110 PM EST FRI JAN 10 2014
.SYNOPSIS...
UPPER TROUGH EXITS EAST BY NOON. TEMPERATURES MODERATING INTO
SATURDAY BEFORE COLD FRONT WITH RAIN CROSSES. WEAK HIGH PRESSURE
PASSES SUNDAY. COLD FRONTS DUE EARLY AND LATE NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
NO CHANGES. WORKING ON THE AFTERNOON PACKAGE.
PREVIOUS DISCUSSION...
RADAR IMAGES SHOW A BROAD AREA OF LIGHT PCPN BOUNCING FROM LIGHT
RAIN TO MIXED SNOW MAINLY NORTHERN PORTIONS OF SOUTHEAST OH AND
NORTHERN EXTREME OF WV. EXPECT THIS AREA TO GRADUALLY MOVE
EASTWARD THROUGH THE EARLY MORNING HOURS. PCPN SHOULD BE PUSHED
EAST OVER THE EASTERN MOUNTAINS BY MID MORNING LEAVING THE
LOWLANDS PCPN FREE...AND DIMINISHING OVER THE MOUNTAINS TOWARDS
NOON.
THE HIGH RESOLUTION MODEL HRRR HAS THE CLOSER SOLUTION WHEN
COMPARED WITH RADAR IMAGES. THE RUC13 LOOKS ABOUT 6 TO 12 HOURS
SLOWER THAN ACTUAL WEATHER MOVING THROUGH. ADJUSTED POPS PER
LATEST RADAR IMAGES AND THE MATCHING HRRR MODELS THROUGH FRIDAY
MORNING.
TEMPERATURES ACROSS THE LOWLANDS SLOWLY INCREASING MAKING
TRANSITIONING PCPN INTO ALL RAIN. WARM AIR ADVECTION WILL CONTINUE
UNDER SOUTHWEST FLOW KEEPING PCPN LIQUID AND BRINGING RELATIVELY
WARMER TEMPERATURES COMPARED WITH PREVIOUS DAYS.
BELIEVE ONCE RAIN SHOWERS MOVE EAST BY NOON...IT WILL BE A
RELATIVELY DRY FRIDAY. HOWEVER...A STRONG COLD FRONT APPROACHES
FROM THE WEST LATE TONIGHT...WITH A GOOD CHANCE FOR PCPN AND SOME
GUSTY WIND. NOT EXITED ABOUT MODELS SHOWING H85 FLOW ABOUT 50 KNOTS
LATER TONIGHT INTO EARLY SATURDAY MORNING. SOUTHWEST FLOW PARALLEL
TO THE MOUNTAIN...UPGLIDE NOTICEABLE IN 280K ISENTROPIC
CHARTS...AND THE POSSIBILITY OF NIGHT TIME DECOUPLING WILL MAKE
THIS STRONG FLOW TO STRUGGLE TO MIX DOWN TO THE SFC TONIGHT.
INCREASED ONSET OF PCPN TO CATEGORICAL LATE TONIGHT SPREADING FROM
WEST TO EAST. WENT WITH THE MOST REASONABLE MOS CONSENSUS FOR
TEMPERATURES THROUGH THE PERIOD.
TEMPERATURES OVER THE EASTERN SLOPES COULD REMAIN AT OR BELOW
FREEZING ON PROTECTED VALLEYS. THEREFORE...KEPT THE WINTER WEATHER
ADVISORY FOR FREEZING RAIN FOR POCAHONTAS AND RANDOLPH COUNTIES
THROUGH 8 AM THIS MORNING.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
PACIFIC COLD FRONT STILL ON TRACK TO SWEEP ACROSS THE FORECAST
AREA FROM WEST TO EAST SATURDAY MORNING...WITH ASSOC UPPER TROUGH
PROGRESSING NORTHEASTWARD ACROSS THE GREAT LAKES REGION DURING THE
DAY ON SATURDAY. STRONG LOW LEVEL WINDS PUSH INTO MAINLY THE
WESTERN PARTS OF THE AREA OVERNIGHT FRI NIGHT...WHICH CONTINUE
INTO THE SHORT TERM PERIOD EARLY SATURDAY MORNING. 850MB WINDS ARE
PROGGED AROUND 70-75KTS ACROSS THE WESTERN ZONES AND NEAR 50KTS AT
925MB. WIND SPEEDS THIS STRONG AT THIS ALTITUDE WITH ASSOC PRECIP
ALWAYS BRING SOME CONCERN...AS IT/S TOUGH TO KNOW JUST HOW MUCH
PRECIP DRAG WILL BE ABLE TO BRING STRONG WINDS TO THE SURFACE.
HOWEVER...WITH A STOUT INVERSION BELOW 900MB AND A TURNING OF WIND
DIRECTION IN LOW-LEVELS SHOULD RESULT IN LESS RISK FOR HIGH WINDS
AT THE SURFACE VERSUS PREVIOUS EVENTS THIS FALL/WINTER. SPC HAS
NOT INCLUDED OUR FORECAST AREA IN A GENERAL RISK.
NONETHELESS..SOMETHING TO WATCH EARLY SATURDAY MORNING AS THE
PRECIP MOVES ACROSS. ALL IN ALL THOUGH...NOT MUCH CHANGE WITH PREV
FORECAST THINKING. CATEGORICAL POPS EVERYWHERE DURING THE MORNING
HOURS SATURDAY WITH THE FRONT. HIGH PWATS AROUND AN INCH SHOULD
SPELL A FAIRLY QUICK QUARTER TO HALF INCH OF RAIN FOR MOST
LOCATIONS...PERHAPS A LITTLE MORE IN THE EASTERN MOUNTAINS. NO
HYDRO CONCERNS ARE EXPECTED WITH THIS SYSTEM HOWEVER. CONTINUED
PREV FORECAST THINKING WITH REGARD TO A SLIGHT NON-DIURNAL TREND
IN TEMPS ON SATURDAY WITH THE WARMEST 850MB/925MB TEMPS OCCURRING
OVER WESTERN/CENTRAL AREAS BTWN 15Z-18Z SAT. THE BULK OF THE
PRECIP SHOULD BE ALONG AND EAST OF THE I79 CORRIDOR BY 18Z
SAT...WITH SYNOPTIC PRECIP WINDING DOWN AREA-WIDE BY 00Z SUN. WILL
KEEP INHERITED HIGH CHANCE POPS HOWEVER ALONG THE EASTERN SLOPES A
LITTLE LONGER WITH A WESTERLY UPSLOPE FLOW CONTINUING. STILL
APPEARS THE STRONGEST WINDS COME LATE SAT AFTERNOON INTO THE EARLY
OVERNIGHT HOURS SAT NIGHT POST-FRONT...WITH GUSTS IN THE HIGH
COUNTRY TOPPING 40KTS.
BY SATURDAY NIGHT ALL LOCATIONS EXCEPT THE EASTERN MOUNTAINS SHOULD
BE PRECIP-FREE. HIGHER ELEVATIONS MAY SEE SOME LINGERING LIGHT RAIN
OR SNOW SHOWERS THROUGH AROUND THE 06Z-09Z SUN TIME FRAME WITH DEPTH
OF LLVL MOISTURE DECREASING...BUT AGAIN...AMOUNTS ARE EXPECTED TO BE
VERY LIGHT WITH MOST AREAS PROBABLY ACTUALLY ONLY EXPERIENCING
DRIZZLE OR FLURRIES. OVERNIGHT MINS BY EARLY SUN STILL EXPECTED TO
BE IN THE LOW/MID 30S MOST LOWLAND LOCATIONS...WITH MID/UPPER 20S
FOR THE MOUNTAINS. INITIALLY CLOUDY SKIES DURING THE EARLY OVERNIGHT
HOURS SHOULD GRADUALLY BECOME MOSTLY CLEAR TO PARTLY CLOUDY FOR THE
LOWLANDS BY DAWN SUNDAY...WITH OF COURSE LINGERING CLOUDS IN THE
MOUNTAINS.
SUNDAY AND SUNDAY NIGHT...SFC HIGH PRESSURE PASSES TO OUR SOUTH WITH
WINDS BACKING FROM THE WEST TO THE SOUTH BY SUNDAY NIGHT. FLOW ALOFT
ALSO BACKS FROM NEAR ZONAL TO SOUTHWESTERLY AS THE NEXT UPPER TROUGH
DIGS QUICKLY SOUTHEAST INTO THE CENTRAL CONUS. STILL...A NICE PERIOD
WITH MOSTLY SUNNY SKIES FOR ALL LOCATIONS IS EXPECTED. CONTINUED TO
NUDGE MAX TEMPS UPWARD FOR SUNDAY...AS WAS THE PREVIOUS FORECAST
TREND. 850MB/925MB TEMPS SUGGEST LOWLAND LOCATIONS NEAR THE CRW-HTS
CORRIDOR APPROACHING 50F DEGREES. WILL RAISE TEMPS GENERALLY TO THE
MID/UPPER 40S LOWLANDS...WITH MID 30S ON HIGHEST PEAKS. OVERNIGHT
MINS SUNDAY NIGHT/MONDAY MORNING FOR THE LOWLANDS IN THE LOW/MID 30S
STILL LOOK ON TRACK. DID RAISE EASTERN MOUNTAIN MINS UP AND ALSO
CODED UP A NON-DIURNAL TEMP CURVE HERE...WITH DECENT 850MB WARM
ADVECTION NOTED ON CONSENSUS OF MODEL OUTPUT IT APPEARS THAT THE MIN
TEMP WILL BE REALIZED CLOSE TO MIDNIGHT FOR LOCATIONS SUCH AS SNOW
WITH TEMPS CONTINUING A SLOW RISE TOWARDS DAWN MONDAY.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
HIGH PRESSURE OF THE SE US WILL BRING A DRY START TO THE LONG TERM
PERIOD. THERE IS POOR AGREEMENT BETWEEN THE ECMWF AND GFS ON SYSTEM
ARRIVING LATE MONDAY. BOTH INDICATE A FRONTAL PASSAGE...BUT THE
ECMWF ALSO SHOWS A SURFACE WAVE RIDING THE FRONT OUT OF THE
SE...NORTHEAST JUST EAST OF THE APPALACHIANS. THE GFS DOES NOT HAVE
THIS...AND IS INSTEAD JUST A COLD FRONTAL PASSAGE CONNECTED TO A
SURFACE LOW NORTH OF THE GREAT LAKES. TRENDED TOWARD THE
ECMWF...WHICH MESHES WELL WITH LATEST WPC GUIDANCE TOO. HAVE CHANCE
POPS ACROSS WV ZONES WITH THE FRONT/SURFACE WAVE...SLIDE THOSE OUT
TUESDAY. 500MB SHORTWAVE TROUGH PASSES WITH THE FRONT...WITH LARGER
SCALE TROUGH ARRIVING MIDWEEK...BRINGING AN INCREASE IN POPS AGAIN
TUESDAY NIGHT INTO WEDNESDAY.
&&
.AVIATION /17Z FRIDAY THROUGH TUESDAY/...
WITH THE ATMOSPHERE DRYING OUT...SOUTHEAST FLOW AT THE SURFACE
WILL ALLOW FOR DOWNSLOPING AND LIFTING OF THE CEILINGS TO VFR
LATER THIS AFTERNOON AND EVENING. KEEPING THE TERMINALS DRY PER
MODEL GUIDANCE AHEAD OF THE STRONG COLD FRONT EXPECTED AFTER 06Z
SATURDAY.
WITH THE NATURE OF THE COLD FRONT BEING A CLEAN SWEEP TYPE FEATURE
THAT WILL BARREL THROUGH THE CWA...DO NOT THINK THE CEILINGS WILL
GO DOWN TO IFR WITH THE FRONTAL PASSAGE. THE LOWEST CONFIDENCE
WILL COME IN FOR BKW STRICTLY FOR BEING A HIGHER ELEVATION AND NOT
IN A PROTECTED VALLEY. KEEP THAT TAF CONSERVATIVE FOR NOW.
VISIBILITIES COULD DROP TO IFR IN SHOWERS...BUT AGAIN...WITH THE
COLD FRONT PLOWING THROUGH AND NOT GETTING HELD UP BY THE
MOUNTAINS...THE LOW VISIBILITIES SHOULD EXIT WITH THE COLD FRONT.
WINDS WILL INCREASE OUT OF THE SOUTH AHEAD OF THE FRONT WITH GUSTS
HITTING THE 15KT TO 25KT RANGE. AFTER PASSAGE OF THE COLD
FRONT...EXPECT THE WINDS TO TURN SOUTHWESTERLY WITH GUSTS
PERSISTING TO 25KTS.
MAY NEED TO ADD TEMPO GROUPS WITH THE COLD FRONT AS SHOWERS BRING
DOWN GUSTIER WINDS ALOFT FOR AN HOUR OR TWO.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z SATURDAY...
FORECAST CONFIDENCE: HIGH TODAY. MEDIUM TONIGHT.
ALTERNATE SCENARIOS: MAY NEED HIGHER WINDS BEFORE...WITH...AND
AFTER THE FRONT. TIMING ISSUES MAY ONLY BE MINOR...WITHIN A COUPLE
HOURS.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EST 1HRLY 13 14 15 16 17 18 19 20 21 22 23 00
CRW CONSISTENCY H H M M M M M M H H H H
HTS CONSISTENCY H H H M H H L L M H H H
BKW CONSISTENCY M H H H H L L L L L L L
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H H H H H H L L H H H L
CKB CONSISTENCY H H H H H H L L H H H H
AFTER 18Z SATURDAY...
IFR CONDITIONS IN RAIN COULD DEVELOP SATURDAY INTO SUNDAY IN STRONG FLOW
ALOFT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/50
NEAR TERM...ARJ/26
SHORT TERM...50
LONG TERM...MZ
AVIATION...26
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
549 AM EST FRI JAN 10 2014
.SYNOPSIS...
UPPER TROUGH EXITS EAST BY NOON. TEMPERATURES MODERATING INTO
SATURDAY BEFORE COLD FRONT WITH RAIN CROSSES. WEAK HIGH PRESSURE
PASSES SUNDAY. COLD FRONTS DUE EARLY AND LATE NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
RADAR IMAGES SHOW A BROAD AREA OF LIGHT PCPN BOUNCING FROM LIGHT
RAIN TO MIXED SNOW MAINLY NORTHERN PORTIONS OF SOUTHEAST OH AND
NORTHERN EXTREME OF WV. EXPECT THIS AREA TO GRADUALLY MOVE
EASTWARD THROUGH THE EARLY MORNING HOURS. PCPN SHOULD BE PUSHED
EAST OVER THE EASTERN MOUNTAINS BY MID MORNING LEAVING THE
LOWLANDS PCPN FREE...AND DIMINISHING OVER THE MOUNTAINS TOWARDS
NOON.
THE HIGH RESOLUTION MODEL HRRR HAS THE CLOSER SOLUTION WHEN
COMPARED WITH RADAR IMAGES. THE RUC13 LOOKS ABOUT 6 TO 12 HOURS
SLOWER THAN ACTUAL WEATHER MOVING THROUGH. ADJUSTED POPS PER
LATEST RADAR IMAGES AND THE MATCHING HRRR MODELS THROUGH FRIDAY
MORNING.
TEMPERATURES ACROSS THE LOWLANDS SLOWLY INCREASING MAKING
TRANSITIONING PCPN INTO ALL RAIN. WARM AIR ADVECTION WILL CONTINUE
UNDER SOUTHWEST FLOW KEEPING PCPN LIQUID AND BRINGING RELATIVELY
WARMER TEMPERATURES COMPARED WITH PREVIOUS DAYS.
BELIEVE ONCE RAIN SHOWERS MOVE EAST BY NOON...IT WILL BE A
RELATIVELY DRY FRIDAY. HOWEVER...A STRONG COLD FRONT APPROACHES
FROM THE WEST LATE TONIGHT...WITH A GOOD CHANCE FOR PCPN AND SOME
GUSTY WIND. NOT EXITED ABOUT MODELS SHOWING H85 FLOW ABOUT 50 KNOTS
LATER TONIGHT INTO EARLY SATURDAY MORNING. SOUTHWEST FLOW PARALLEL
TO THE MOUNTAIN...UPGLIDE NOTICEABLE IN 280K ISENTROPIC
CHARTS...AND THE POSSIBILITY OF NIGHT TIME DECOUPLING WILL MAKE
THIS STRONG FLOW TO STRUGGLE TO MIX DOWN TO THE SFC TONIGHT.
INCREASED ONSET OF PCPN TO CATEGORICAL LATE TONIGHT SPREADING FROM
WEST TO EAST. WENT WITH THE MOST REASONABLE MOS CONSENSUS FOR
TEMPERATURES THROUGH THE PERIOD.
TEMPERATURES OVER THE EASTERN SLOPES COULD REMAIN AT OR BELOW
FREEZING ON PROTECTED VALLEYS. THEREFORE...KEPT THE WINTER WEATHER
ADVISORY FOR FREEZING RAIN FOR POCAHONTAS AND RANDOLPH COUNTIES
THROUGH 8 AM THIS MORNING.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
PACIFIC COLD FRONT STILL ON TRACK TO SWEEP ACROSS THE FORECAST
AREA FROM WEST TO EAST SATURDAY MORNING...WITH ASSOC UPPER TROUGH
PROGRESSING NORTHEASTWARD ACROSS THE GREAT LAKES REGION DURING THE
DAY ON SATURDAY. STRONG LOW LEVEL WINDS PUSH INTO MAINLY THE
WESTERN PARTS OF THE AREA OVERNIGHT FRI NIGHT...WHICH CONTINUE
INTO THE SHORT TERM PERIOD EARLY SATURDAY MORNING. 850MB WINDS ARE
PROGGED AROUND 70-75KTS ACROSS THE WESTERN ZONES AND NEAR 50KTS AT
925MB. WIND SPEEDS THIS STRONG AT THIS ALTITUDE WITH ASSOC PRECIP
ALWAYS BRING SOME CONCERN...AS IT/S TOUGH TO KNOW JUST HOW MUCH
PRECIP DRAG WILL BE ABLE TO BRING STRONG WINDS TO THE SURFACE.
HOWEVER...WITH A STOUT INVERSION BELOW 900MB AND A TURNING OF WIND
DIRECTION IN LOW-LEVELS SHOULD RESULT IN LESS RISK FOR HIGH WINDS
AT THE SURFACE VERSUS PREVIOUS EVENTS THIS FALL/WINTER. SPC HAS
NOT INCLUDED OUR FORECAST AREA IN A GENERAL RISK.
NONETHELESS..SOMETHING TO WATCH EARLY SATURDAY MORNING AS THE
PRECIP MOVES ACROSS. ALL IN ALL THOUGH...NOT MUCH CHANGE WITH PREV
FORECAST THINKING. CATEGORICAL POPS EVERYWHERE DURING THE MORNING
HOURS SATURDAY WITH THE FRONT. HIGH PWATS AROUND AN INCH SHOULD
SPELL A FAIRLY QUICK QUARTER TO HALF INCH OF RAIN FOR MOST
LOCATIONS...PERHAPS A LITTLE MORE IN THE EASTERN MOUNTAINS. NO
HYDRO CONCERNS ARE EXPECTED WITH THIS SYSTEM HOWEVER. CONTINUED
PREV FORECAST THINKING WITH REGARD TO A SLIGHT NON-DIURNAL TREND
IN TEMPS ON SATURDAY WITH THE WARMEST 850MB/925MB TEMPS OCCURRING
OVER WESTERN/CENTRAL AREAS BTWN 15Z-18Z SAT. THE BULK OF THE
PRECIP SHOULD BE ALONG AND EAST OF THE I79 CORRIDOR BY 18Z
SAT...WITH SYNOPTIC PRECIP WINDING DOWN AREA-WIDE BY 00Z SUN. WILL
KEEP INHERITED HIGH CHANCE POPS HOWEVER ALONG THE EASTERN SLOPES A
LITTLE LONGER WITH A WESTERLY UPSLOPE FLOW CONTINUING. STILL
APPEARS THE STRONGEST WINDS COME LATE SAT AFTERNOON INTO THE EARLY
OVERNIGHT HOURS SAT NIGHT POST-FRONT...WITH GUSTS IN THE HIGH
COUNTRY TOPPING 40KTS.
BY SATURDAY NIGHT ALL LOCATIONS EXCEPT THE EASTERN MOUNTAINS SHOULD
BE PRECIP-FREE. HIGHER ELEVATIONS MAY SEE SOME LINGERING LIGHT RAIN
OR SNOW SHOWERS THROUGH AROUND THE 06Z-09Z SUN TIME FRAME WITH DEPTH
OF LLVL MOISTURE DECREASING...BUT AGAIN...AMOUNTS ARE EXPECTED TO BE
VERY LIGHT WITH MOST AREAS PROBABLY ACTUALLY ONLY EXPERIENCING
DRIZZLE OR FLURRIES. OVERNIGHT MINS BY EARLY SUN STILL EXPECTED TO
BE IN THE LOW/MID 30S MOST LOWLAND LOCATIONS...WITH MID/UPPER 20S
FOR THE MOUNTAINS. INITIALLY CLOUDY SKIES DURING THE EARLY OVERNIGHT
HOURS SHOULD GRADUALLY BECOME MOSTLY CLEAR TO PARTLY CLOUDY FOR THE
LOWLANDS BY DAWN SUNDAY...WITH OF COURSE LINGERING CLOUDS IN THE
MOUNTAINS.
SUNDAY AND SUNDAY NIGHT...SFC HIGH PRESSURE PASSES TO OUR SOUTH WITH
WINDS BACKING FROM THE WEST TO THE SOUTH BY SUNDAY NIGHT. FLOW ALOFT
ALSO BACKS FROM NEAR ZONAL TO SOUTHWESTERLY AS THE NEXT UPPER TROUGH
DIGS QUICKLY SOUTHEAST INTO THE CENTRAL CONUS. STILL...A NICE PERIOD
WITH MOSTLY SUNNY SKIES FOR ALL LOCATIONS IS EXPECTED. CONTINUED TO
NUDGE MAX TEMPS UPWARD FOR SUNDAY...AS WAS THE PREVIOUS FORECAST
TREND. 850MB/925MB TEMPS SUGGEST LOWLAND LOCATIONS NEAR THE CRW-HTS
CORRIDOR APPROACHING 50F DEGREES. WILL RAISE TEMPS GENERALLY TO THE
MID/UPPER 40S LOWLANDS...WITH MID 30S ON HIGHEST PEAKS. OVERNIGHT
MINS SUNDAY NIGHT/MONDAY MORNING FOR THE LOWLANDS IN THE LOW/MID 30S
STILL LOOK ON TRACK. DID RAISE EASTERN MOUNTAIN MINS UP AND ALSO
CODED UP A NON-DIURNAL TEMP CURVE HERE...WITH DECENT 850MB WARM
ADVECTION NOTED ON CONSENSUS OF MODEL OUTPUT IT APPEARS THAT THE MIN
TEMP WILL BE REALIZED CLOSE TO MIDNIGHT FOR LOCATIONS SUCH AS SNOW
WITH TEMPS CONTINUING A SLOW RISE TOWARDS DAWN MONDAY.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
HIGH PRESSURE OF THE SE US WILL BRING A DRY START TO THE LONG TERM
PERIOD. THERE IS POOR AGREEMENT BETWEEN THE ECMWF AND GFS ON SYSTEM
ARRIVING LATE MONDAY. BOTH INDICATE A FRONTAL PASSAGE...BUT THE
ECMWF ALSO SHOWS A SURFACE WAVE RIDING THE FRONT OUT OF THE
SE...NORTHEAST JUST EAST OF THE APPALACHIANS. THE GFS DOES NOT HAVE
THIS...AND IS INSTEAD JUST A COLD FRONTAL PASSAGE CONNECTED TO A
SURFACE LOW NORTH OF THE GREAT LAKES. TRENDED TOWARD THE
ECMWF...WHICH MESHES WELL WITH LATEST WPC GUIDANCE TOO. HAVE CHANCE
POPS ACROSS WV ZONES WITH THE FRONT/SURFACE WAVE...SLIDE THOSE OUT
TUESDAY. 500MB SHORTWAVE TROUGH PASSES WITH THE FRONT...WITH LARGER
SCALE TROUGH ARRIVING MIDWEEK...BRINGING AN INCREASE IN POPS AGAIN
TUESDAY NIGHT INTO WEDNESDAY.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
LATEST RADAR IMAGES INDICATE AN AREA OF SHOWERS MOVING OVER THE
EASTERN MOUNTAINS THIS MORNING. EXPECT RAIN SHOWERS TO EXIT THE
EASTERN MOUNTAINS BY MID MORNING. HOWEVER...AREAS UNDER
TEMPERATURES AT OR BELOW FREEZING IN POCAHONTAS AND RANDOLPH
COUNTIES COULD EXPERIENCE BRIEF PERIODS OF FREEZING RAIN.
SOUTHWEST FLOW BRINGS WARM AIR ADVECTION...WHILE COLD AIR MASS
REMAINS IN PLACE FAR NORTH OVER PORTIONS OF SOUTHEAST OH AND
EXTREME NORTHERN WV. ALL PCPN SHOULD BE ALL RAIN FROM NOW ON
ACROSS THE LOWLANDS AND CENTRAL MOUNTAINS.
BRIEF PERIODS OF IFR/MVFR CEILINGS EXPECTED AT BKW AFTER 09Z...AND
ACROSS ALL SITES FRIDAY AFTERNOON AROUND 17Z. OTHERWISE...VFR/MVFR
MIST AND RAIN EXPECTED FOR THE MOST PART ON FRIDAY. PCPN SHOULD
START DIMINISHING FROM WEST TO EAST FROM 13Z TO 17 FRIDAY.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z SATURDAY...
ALTERNATE SCENARIOS: TIMING AND ONSET OF PRECIP MAY VARY. PRECIP
TYPE AND CIG CATEGORY MAY VARY FROM FORECAST.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 11 12 13 14 15 16 17 18 19 20 21 22
EST 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY M H H H H H H H H H H H
BKW CONSISTENCY H H H M M M M M M M M M
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 12Z SATURDAY...
IFR CONDITIONS IN RAIN COULD DEVELOP SATURDAY INTO SUNDAY IN STRONG FLOW
ALOFT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FREEZING RAIN ADVISORY UNTIL 8 AM EST THIS MORNING FOR WVZ046-
047.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/50
NEAR TERM...ARJ
SHORT TERM...50
LONG TERM...MZ
AVIATION...ARJ
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
347 AM EST FRI JAN 10 2014
.SYNOPSIS...
UPPER TROUGH EXITS EAST BY NOON. TEMPERATURES MODERATING INTO
SATURDAY BEFORE COLD FRONT WITH RAIN CROSSES. WEAK HIGH PRESSURE
PASSES SUNDAY. COLD FRONTS DUE EARLY AND LATE NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
RADAR IMAGES SHOW A BROAD AREA OF LIGHT PCPN BOUNCING FROM LIGHT
RAIN TO MIXED SNOW MAINLY NORTHERN PORTIONS OF SOUTHEAST OH AND
NORTHERN EXTREME OF WV. EXPECT THIS AREA TO GRADUALLY MOVE
EASTWARD THROUGH THE EARLY MORNING HOURS. PCPN SHOULD BE PUSHED
EAST OVER THE EASTERN MOUNTAINS BY MID MORNING LEAVING THE
LOWLANDS PCPN FREE...AND DIMINISHING OVER THE MOUNTAINS TOWARDS
NOON.
THE HIGH RESOLUTION MODEL HRRR HAS THE CLOSER SOLUTION WHEN
COMPARED WITH RADAR IMAGES. THE RUC13 LOOKS ABOUT 6 TO 12 HOURS
SLOWER THAN ACTUAL WEATHER MOVING THROUGH. ADJUSTED POPS PER
LATEST RADAR IMAGES AND THE MATCHING HRRR MODELS THROUGH FRIDAY
MORNING.
TEMPERATURES ACROSS THE LOWLANDS SLOWLY INCREASING MAKING
TRANSITIONING PCPN INTO ALL RAIN. WARM AIR ADVECTION WILL CONTINUE
UNDER SOUTHWEST FLOW KEEPING PCPN LIQUID AND BRINGING RELATIVELY
WARMER TEMPERATURES COMPARED WITH PREVIOUS DAYS.
BELIEVE ONCE RAIN SHOWERS MOVE EAST BY NOON...IT WILL BE A
RELATIVELY DRY FRIDAY. HOWEVER...A STRONG COLD FRONT APPROACHES
FROM THE WEST LATE TONIGHT...WITH A GOOD CHANCE FOR PCPN AND SOME
GUSTY WIND. NOT EXITED ABOUT MODELS SHOWING H85 FLOW ABOUT 50 KNOTS
LATER TONIGHT INTO EARLY SATURDAY MORNING. SOUTHWEST FLOW PARALLEL
TO THE MOUNTAIN...UPGLIDE NOTICEABLE IN 280K ISENTROPIC
CHARTS...AND THE POSSIBILITY OF NIGHT TIME DECOUPLING WILL MAKE
THIS STRONG FLOW TO STRUGGLE TO MIX DOWN TO THE SFC TONIGHT.
INCREASED ONSET OF PCPN TO CATEGORICAL LATE TONIGHT SPREADING FROM
WEST TO EAST. WENT WITH THE MOST REASONABLE MOS CONSENSUS FOR
TEMPERATURES THROUGH THE PERIOD.
TEMPERATURES OVER THE EASTERN SLOPES COULD REMAIN AT OR BELOW
FREEZING ON PROTECTED VALLEYS. THEREFORE...KEPT THE WINTER WEATHER
ADVISORY FOR FREEZING RAIN FOR POCAHONTAS AND RANDOLPH COUNTIES
THROUGH 8 AM THIS MORNING.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
PACIFIC COLD FRONT STILL ON TRACK TO SWEEP ACROSS THE FORECAST
AREA FROM WEST TO EAST SATURDAY MORNING...WITH ASSOC UPPER TROUGH
PROGRESSING NORTHEASTWARD ACROSS THE GREAT LAKES REGION DURING THE
DAY ON SATURDAY. STRONG LOW LEVEL WINDS PUSH INTO MAINLY THE
WESTERN PARTS OF THE AREA OVERNIGHT FRI NIGHT...WHICH CONTINUE
INTO THE SHORT TERM PERIOD EARLY SATURDAY MORNING. 850MB WINDS ARE
PROGGED AROUND 70-75KTS ACROSS THE WESTERN ZONES AND NEAR 50KTS AT
925MB. WIND SPEEDS THIS STRONG AT THIS ALTITUDE WITH ASSOC PRECIP
ALWAYS BRING SOME CONCERN...AS IT/S TOUGH TO KNOW JUST HOW MUCH
PRECIP DRAG WILL BE ABLE TO BRING STRONG WINDS TO THE SURFACE.
HOWEVER...WITH A STOUT INVERSION BELOW 900MB AND A TURNING OF WIND
DIRECTION IN LOW-LEVELS SHOULD RESULT IN LESS RISK FOR HIGH WINDS
AT THE SURFACE VERSUS PREVIOUS EVENTS THIS FALL/WINTER. SPC HAS
NOT INCLUDED OUR FORECAST AREA IN A GENERAL RISK.
NONETHELESS..SOMETHING TO WATCH EARLY SATURDAY MORNING AS THE
PRECIP MOVES ACROSS. ALL IN ALL THOUGH...NOT MUCH CHANGE WITH PREV
FORECAST THINKING. CATEGORICAL POPS EVERYWHERE DURING THE MORNING
HOURS SATURDAY WITH THE FRONT. HIGH PWATS AROUND AN INCH SHOULD
SPELL A FAIRLY QUICK QUARTER TO HALF INCH OF RAIN FOR MOST
LOCATIONS...PERHAPS A LITTLE MORE IN THE EASTERN MOUNTAINS. NO
HYDRO CONCERNS ARE EXPECTED WITH THIS SYSTEM HOWEVER. CONTINUED
PREV FORECAST THINKING WITH REGARD TO A SLIGHT NON-DIURNAL TREND
IN TEMPS ON SATURDAY WITH THE WARMEST 850MB/925MB TEMPS OCCURRING
OVER WESTERN/CENTRAL AREAS BTWN 15Z-18Z SAT. THE BULK OF THE
PRECIP SHOULD BE ALONG AND EAST OF THE I79 CORRIDOR BY 18Z
SAT...WITH SYNOPTIC PRECIP WINDING DOWN AREA-WIDE BY 00Z SUN. WILL
KEEP INHERITED HIGH CHANCE POPS HOWEVER ALONG THE EASTERN SLOPES A
LITTLE LONGER WITH A WESTERLY UPSLOPE FLOW CONTINUING. STILL
APPEARS THE STRONGEST WINDS COME LATE SAT AFTERNOON INTO THE EARLY
OVERNIGHT HOURS SAT NIGHT POST-FRONT...WITH GUSTS IN THE HIGH
COUNTRY TOPPING 40KTS.
BY SATURDAY NIGHT ALL LOCATIONS EXCEPT THE EASTERN MOUNTAINS SHOULD
BE PRECIP-FREE. HIGHER ELEVATIONS MAY SEE SOME LINGERING LIGHT RAIN
OR SNOW SHOWERS THROUGH AROUND THE 06Z-09Z SUN TIME FRAME WITH DEPTH
OF LLVL MOISTURE DECREASING...BUT AGAIN...AMOUNTS ARE EXPECTED TO BE
VERY LIGHT WITH MOST AREAS PROBABLY ACTUALLY ONLY EXPERIENCING
DRIZZLE OR FLURRIES. OVERNIGHT MINS BY EARLY SUN STILL EXPECTED TO
BE IN THE LOW/MID 30S MOST LOWLAND LOCATIONS...WITH MID/UPPER 20S
FOR THE MOUNTAINS. INITIALLY CLOUDY SKIES DURING THE EARLY OVERNIGHT
HOURS SHOULD GRADUALLY BECOME MOSTLY CLEAR TO PARTLY CLOUDY FOR THE
LOWLANDS BY DAWN SUNDAY...WITH OF COURSE LINGERING CLOUDS IN THE
MOUNTAINS.
SUNDAY AND SUNDAY NIGHT...SFC HIGH PRESSURE PASSES TO OUR SOUTH WITH
WINDS BACKING FROM THE WEST TO THE SOUTH BY SUNDAY NIGHT. FLOW ALOFT
ALSO BACKS FROM NEAR ZONAL TO SOUTHWESTERLY AS THE NEXT UPPER TROUGH
DIGS QUICKLY SOUTHEAST INTO THE CENTRAL CONUS. STILL...A NICE PERIOD
WITH MOSTLY SUNNY SKIES FOR ALL LOCATIONS IS EXPECTED. CONTINUED TO
NUDGE MAX TEMPS UPWARD FOR SUNDAY...AS WAS THE PREVIOUS FORECAST
TREND. 850MB/925MB TEMPS SUGGEST LOWLAND LOCATIONS NEAR THE CRW-HTS
CORRIDOR APPROACHING 50F DEGREES. WILL RAISE TEMPS GENERALLY TO THE
MID/UPPER 40S LOWLANDS...WITH MID 30S ON HIGHEST PEAKS. OVERNIGHT
MINS SUNDAY NIGHT/MONDAY MORNING FOR THE LOWLANDS IN THE LOW/MID 30S
STILL LOOK ON TRACK. DID RAISE EASTERN MOUNTAIN MINS UP AND ALSO
CODED UP A NON-DIURNAL TEMP CURVE HERE...WITH DECENT 850MB WARM
ADVECTION NOTED ON CONSENSUS OF MODEL OUTPUT IT APPEARS THAT THE MIN
TEMP WILL BE REALIZED CLOSE TO MIDNIGHT FOR LOCATIONS SUCH AS SNOW
WITH TEMPS CONTINUING A SLOW RISE TOWARDS DAWN MONDAY.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
HIGH PRESSURE OF THE SE US WILL BRING A DRY START TO THE LONG TERM
PERIOD. THERE IS POOR AGREEMENT BETWEEN THE ECMWF AND GFS ON SYSTEM
ARRIVING LATE MONDAY. BOTH INDICATE A FRONTAL PASSAGE...BUT THE
ECMWF ALSO SHOWS A SURFACE WAVE RIDING THE FRONT OUT OF THE
SE...NORTHEAST JUST EAST OF THE APPALACHIANS. THE GFS DOES NOT HAVE
THIS...AND IS INSTEAD JUST A COLD FRONTAL PASSAGE CONNECTED TO A
SURFACE LOW NORTH OF THE GREAT LAKES. TRENDED TOWARD THE
ECMWF...WHICH MESHES WELL WITH LATEST WPC GUIDANCE TOO. HAVE CHANCE
POPS ACROSS WV ZONES WITH THE FRONT/SURFACE WAVE...SLIDE THOSE OUT
TUESDAY. 500MB SHORTWAVE TROUGH PASSES WITH THE FRONT...WITH LARGER
SCALE TROUGH ARRIVING MIDWEEK...BRINGING AN INCREASE IN POPS AGAIN
TUESDAY NIGHT INTO WEDNESDAY.
&&
.AVIATION /09Z FRIDAY THROUGH TUESDAY/...
RADAR IMAGES INDICATE AN AREA OF SHOWERS MOVING FROM THE SOUTHWEST
INTO WV AND SOUTHEAST OH OVERNIGHT. EXPECT MVFR CONDITIONS UNDER
RAIN...MAINLY ALONG AND NORTH OF LINES FROM HTS TO CRW...AND CRW
TO BKW AND ELEVATED TERRAIN.
SOUTHWEST FLOW BRINGS WAA TO THE AREA...WHILE COLD AIR MASS
REMAINS IN PLACE FAR NORTH OVER PORTIONS OF SOUTHEAST OH AND
EXTREME NORTHERN WV. EXPECT SNOW MIXED WITH SLEET OR
RAIN...OVERNIGHT TRANSITIONING TO ALL RAIN BY FRIDAY MORNING.
SOUTH OF THE AFOREMENTIONED LINES PCPN SHOULD STAY ALL RAIN.
BRIEF PERIODS OF IFR/MVFR CEILINGS EXPECTED AT BKW AFTER 09Z...AND
ACROSS ALL SITES FRIDAY AFTERNOON AROUND 17Z. OTHERWISE...VFR/MVFR
MIST AND RAIN EXPECTED FOR THE MOST PART ON FRIDAY. PCPN SHOULD
START DIMINISHING FROM WEST TO EAST FROM 13Z TO 17 FRIDAY.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z SATURDAY...
ALTERNATE SCENARIOS: TIMING AND ONSET OF PRECIP MAY VARY. PRECIP
TYPE AND CIG CATEGORY MAY VARY FROM FORECAST.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE FRI 01/10/14
UTC 1HRLY 08 09 10 11 12 13 14 15 16 17 18 19
EST 1HRLY 03 04 05 06 07 08 09 10 11 12 13 14
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H M H H H H H M H
BKW CONSISTENCY H H H H H H M M M M M M
EKN CONSISTENCY M H H H H H H H H H H H
PKB CONSISTENCY M M H H H H H H H H H H
CKB CONSISTENCY M M H H H H H H H H H H
AFTER 06Z SATURDAY...
IFR CONDITIONS IN RAIN COULD DEVELOP SATURDAY INTO SUNDAY IN STRONG FLOW
ALOFT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FREEZING RAIN ADVISORY UNTIL 8 AM EST THIS MORNING FOR WVZ046-
047.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/50
NEAR TERM...ARJ
SHORT TERM...50
LONG TERM...MZ
AVIATION...ARJ
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
102 AM EST FRI JAN 10 2014
.SYNOPSIS...
UPPER TROUGH PASSES TONIGHT. TEMPERATURES MODERATING INTO SATURDAY
BEFORE COLD FRONT WITH RAIN CROSSES. WEAK HIGH PRESSURE PASSES
SUNDAY. COLD FRONTS DUE EARLY AND LATE NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
ADJUSTED POPS PER LATEST RADAR IMAGES AND THE MATCHING HRRR MODELS
THROUGH FRIDAY MORNING. REST OF FORECAST REMAINS REPRESENTATIVE. KEPT WINTER
WEATHER ADVISORY FOR FREEZING RAIN ACROSS POCAHONTAS AND RANDOLPH
UNTIL 8AM FRIDAY.
PREVIOUS DISCUSSION BELOW...
9 PM...TWEAKED POP FORECAST. PRECIPITATION HAVING A HARD TIME
REACHING GROUND AT THIS POINT AS ATMOSPHERE STILL A BIT TOO
DRY...BUT DEW POINTS ARE RISING...AND ATMOSPHERE MOISTENING
UP...SO EXPECTING PRECIPITATION TO BE REACHING THE GROUND IN THE
CWA SHORTLY.
PREVIOUS DISCUSSION FOLLOWS...
HIGH PRESSURE CURRENTLY DEPARTING OFF THE NEW YORK/NEW JERSEY COAST
THIS AFTERNOON WITH MID LEVEL MOISTURE OVERSPREADING THE REGION.
A TROUGH EMBEDDED IN THE 500MB FLOW WILL TRAVERSE THE MIDDLE OHIO
VALLEY TONIGHT BRINGING THE NEXT ROUND OF PRECIPITATION FOR THE CWA.
TWO MAIN ISSUES WILL BE AT PLAY HERE. FIRST IS THE TEMPERATURES LATE
THIS EVENING AND EARLY TONIGHT AS THEY FALL INTO THE LOWER TO MIDDLE
30S OVER THE LOWLANDS. THE NORTHERN TIER OF COUNTIES COULD FLIRT
WITH THE FREEZING MARK...AND WITH A WARM LAYER OFF THE
SURFACE...MIXED PRECIPITATION TYPES ARE POSSIBLE AT THE ONSET.
SOUNDINGS ARE MORE SUPPORTIVE OF THE SNOW/SLEET/RAIN REGIME THROUGH
TIME THAN FREEZING RAIN WEST OF THE MOUNTAINS. THIS WARM LAYER ALOFT
WEST OF THE MOUNTAINS WILL BE SUPPLIED BY INCREASING SOUTHWESTERLY
FLOW THROUGH 850MB.
THE SECOND ITEM IS THE SOUTH SOUTHEAST FLOW AT THE SURFACE...AND IN
THE LOWER LEVELS ALONG THE EASTERN SLOPES OF THE NORTHEAST
MOUNTAINS. THIS UPSLOPE WILL WORK AT TIMES IN CONJUNCTION WITH THE
FORCING ALOFT FROM THE VORTICITY ADVECTION AND WILL RESULT IN
FREEZING RAIN THANKS TO TEMPERATURES THAT WILL BEGIN COLDER THAN
AREAS WEST AND SUPPORTED THROUGH 12Z FRIDAY BY THE COOL UPSLOPE
FLOW. AFTER THIS TIME FRAME...WARM ADVECTION JUST ABOVE THE SURFACE
WILL FINALLY TAKE OVER AND SCOUR OUT THE COLD AIR WEDGE ON THE EAST
SIDE OF THE MOUNTAINS.
IT IS IMPORTANT TO NOTE THAT THE NATURE OF THE FLOW BEING SOUTH
SOUTHEASTERLY AS OPPOSED TO SOUTHEASTERLY WILL LIKELY EXCLUDE THE
SOUTHERN MOUNTAINS FROM THE UPSLOPING CONDITIONS. EXPECTING THE BULK
OF THE FREEZING RAIN TO FALL IN RANDOLPH AND POCAHONTAS
COUNTIES...AND ALONG THE FAR EASTERN PORTIONS OF
WEBSTER...NICHOLAS...AND FAYETTE.
BY THE LATE MORNING FRIDAY...ALL ZONES SHOULD BE IN PLAIN RAIN AS
THE DISTURBANCE ALOFT QUICKLY LIFTS INTO NEW ENGLAND AND THE SOUTH
SOUTHEAST UPSLOPE CEASES.
850MB TEMPERATURES CONTINUE TO CLIMB THROUGH FRIDAY...AND WILL
EXPECT SOME LOWLAND LOW 50S DESPITE THE LACK OF APPRECIABLE
INSOLATION.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY/...
MODEL TIMING IS A LITTLE FASTER ON OCCLUSION THAT MOVES THROUGH
SAT. PRECIPITATION ARRIVES AFTER MIDNIGHT FRI NT FROM THE W...AND
IN THE GREENBRIER VALLEY ON SSE UPSLOPE FLOW THERE. PW VALUES
CLIMB JUST OVER AN INCH SO A QUICK HALF INCH RAINFALL APPEARS
PLAUSIBLE...HIGHER AMOUNTS IN THE MOUNTAINS AND LOWER IN THE W.
STRONG LOW LEVEL WINDS AHEAD OF THE FRONT WILL NOT MIX DOWN VERY
WELL GIVEN BOUNDARY LAYER INVERSION. PEAK GUSTS WILL BE BEHIND THE
FRONT SAT AFTERNOON AND NT...UP OVER 40 KTS OVER THE HIGHER TERRAIN.
THE FRONT MOVES THROUGH AROUND MIDDAY AND EARLY AFTERNOON...FOLLOWED
BY LIGHT UPSLOPE SHOWERS AND DRIZZLE ON W FLOW. OF PACIFIC
ORIGIN...THIS AIR MASS PALES IN COMPARISON TO ITS PREDECESSOR
EARLIER THIS WEEK...THE OPPORTUNITY FOR SNOW ON THE BACKSIDE IS
LIMITED TO THE HIGHEST TERRAIN...AS H85 TEMPERATURES ONLY GET DOWN
TO -5C OR SO.
THE WEAK PACIFIC HIGH PASSES S OF THE AREA SUN...WITH A RETURN TO S
FLOW IN THE AFTERNOON. UPSLOPE FLOW WILL BE UT OFF AND CLEARING
WILL ENSUE.
TEMPERATURES RISE A BIT OVERNIGHT FRI NT AHEAD OF THE FRONT AND THEN
START TO FALL A BIT SAT AFTERNOON BEHIND IT...USED MAINLY THE MET
AND HAVE SMALLER DIURNAL RANGE THAN PREVIOUS. LOWS SAT NT LOOKED
GOOD EVEN WITH THE QUICKER COLD ADVECTION. RAISED HIGHS SUN A BIT
VIA THE BIAS CORRECTED MEX GIVEN FASTER CLEARING AND REVERSAL TO
WARM ADVECTION COME SUN AFTERNOON.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
HIGH PRESSURE OF THE SE US WILL BRING A DRY START TO THE LONG TERM
PERIOD. THERE IS POOR AGREEMENT BETWEEN THE ECMWF AND GFS ON SYSTEM
ARRIVING LATE MONDAY. BOTH INDICATE A FRONTAL PASSAGE...BUT THE
ECMWF ALSO SHOWS A SURFACE WAVE RIDING THE FRONT OUT OF THE
SE...NORTHEAST JUST EAST OF THE APPALACHIANS. THE GFS DOES NOT HAVE
THIS...AND IS INSTEAD JUST A COLD FRONTAL PASSAGE CONNECTED TO A
SURFACE LOW NORTH OF THE GREAT LAKES. TRENDED TOWARD THE
ECMWF...WHICH MESHES WELL WITH LATEST WPC GUIDANCE TOO. HAVE CHANCE
POPS ACROSS WV ZONES WITH THE FRONT/SURFACE WAVE...SLIDE THOSE OUT
TUESDAY. 500MB SHORTWAVE TROUGH PASSES WITH THE FRONT...WITH LARGER
SCALE TROUGH ARRIVING MIDWEEK...BRINGING AN INCREASE IN POPS AGAIN
TUESDAY NIGHT INTO WEDNESDAY.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
RADAR IMAGES INDICATE AN AREA OF SHOWERS MOVING FROM THE SOUTHWEST
INTO WV AND SOUTHEAST OH OVERNIGHT. EXPECT MVFR CONDITIONS UNDER
RAIN...MAINLY ALONG AND NORTH OF LINES FROM HTS TO CRW...AND CRW
TO BKW AND ELEVATED TERRAIN.
SOUTHWEST FLOW BRINGS WAA TO THE AREA...WHILE COLD AIR MASS
REMAINS IN PLACE FAR NORTH OVER PORTIONS OF SOUTHEAST OH AND
EXTREME NORTHERN WV. EXPECT SNOW MIXED WITH SLEET OR
RAIN...OVERNIGHT TRANSITIONING TO ALL RAIN BY FRIDAY MORNING.
SOUTH OF THE AFOREMENTIONED LINES PCPN SHOULD STAY ALL RAIN.
BRIEF PERIODS OF IFR/MVFR CEILINGS EXPECTED AT BKW AFTER 09Z...AND
ACROSS ALL SITES FRIDAY AFTERNOON AROUND 17Z. OTHERWISE...VFR/MVFR
MIST AND RAIN EXPECTED FOR THE MOST PART ON FRIDAY. PCPN SHOULD
START DIMINISHING FROM WEST TO EAST FROM 13Z TO 17 FRIDAY.
FORECAST CONFIDENCE: HIGH UNTIL 06Z FRIDAY. MEDIUM.
ALTERNATE SCENARIOS: TIMING AND ONSET OF PRECIP MAY VARY. PRECIP
TYPE AND CIG CATEGORY MAY VARY FROM FORECAST.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE FRI 01/10/14
UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
EST 1HRLY 01 02 03 04 05 06 07 08 09 10 11 12
CRW CONSISTENCY H M H H H H H H H H H H
HTS CONSISTENCY M M H H H H M H H H H M
BKW CONSISTENCY H H H H H H H H M M M M
EKN CONSISTENCY H M M H H H H H H H H H
PKB CONSISTENCY M M M M H H H H H H H H
CKB CONSISTENCY H M M M H H H H H H H H
AFTER 06Z SATURDAY...
IFR CONDITIONS IN RAIN COULD DEVELOP SATURDAY INTO SUNDAY IN STRONG FLOW
ALOFT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FREEZING RAIN ADVISORY UNTIL 8 AM EST THIS MORNING FOR WVZ046-
047.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/MZ/26
NEAR TERM...ARJ/SL/26
SHORT TERM...TRM
LONG TERM...MZ
AVIATION...ARJ
AREA FORECAST DISCUSSION
NWS TULSA OK
1123 PM CST THU JAN 9 2014
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
LIFR CONDITIONS WILL CONTINUE THROUGH EARLY FRIDAY MORNING IN MOST
AREAS WITH INCREASING CHANCES OF LIGHT DRIZZLE OR RAIN OVER THE
NEXT FEW HOURS. DEEPER MOISTURE SURGING NORTH AHEAD OF AN UPPER
LEVEL SYSTEM WILL LEAD TO WIDESPREAD RAIN AFTER 12Z MAINLY ACROSS
SE OK AND NW AR WITH SOME EMBEDDED THUNDER LIKELY THROUGH ABOUT
18Z. ONSET OF PRECIP WILL LIKELY CORRESPOND TO A SMALL IMPROVEMENT
IN FLIGHT CONDITIONS...WITH FURTHER IMPROVEMENT TO MVFR AND
FINALLY VFR LATE IN THE PERIOD AS A COLD FRONT SWEEPS THROUGH.
&&
.PREV DISCUSSION... /ISSUED 915 PM CST THU JAN 9 2014/
..UPDATE...
DISCUSSION...
A LOW CLOUD DECK WITH PATCHY AREAS OF REDUCED VIS CONTINUED ACROSS
EASTERN OKLAHOMA AND NORTHWEST ARKANSAS THIS EVENING. THESE
CONDITIONS HAVE KEPT TEMPS FROM CHANGING MUCH THROUGH THE EVENING
HOURS...AND IN SOME PLACES...THE TEMP HAS COME UP A DEGREE OR SO.
TEMPERATURES WILL CONTINUE TO HOVER CLOSE TO CURRENT READINGS INTO
THE OVERNIGHT HOURS AND BEGIN SLOWLY WARMING DURING THE EARLY
MORNING HOURS AS AN UPPER LEVEL SHORTWAVE AND ASSOCIATED COLD
FRONT APPROACH THE REGION. THUS...LOW TEMPS TONIGHT WILL MORE THAN
LIKELY BE REALIZED OVER THE NEXT FEW HOURS FOR MOST LOCATIONS.
RAIN CHANCES WILL INCREASE LATE TONIGHT INTO FRIDAY FROM SOUTH TO
NORTH WITH ALSO ISOLATED CHANCES FOR THUNDER AS THE WAVE
APPROACHES. LATEST LOCAL MODEL AND HRRR HAVE BACKED OFF ON THE
TIMING OF PRECIP SPREADING ACROSS THE REGION TONIGHT. THUS...HAVE
BACKED OFF ON POPS SOME THROUGH 12Z FOR THE EVENING UPDATE...
OTHERWISE THE REST OF THE CURRENT FORECAST FOR TONIGHT SEEMS TO BE
HANDLING WELL.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
SHORT TERM...99
LONG TERM....99
AVIATION...14
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1152 PM CST THU JAN 9 2014
.UPDATE...
UPDATED FOR THE 06Z AVIATION DISCUSSION.
&&
.PREV DISCUSSION... /ISSUED 925 PM CST THU JAN 9 2014/
UPDATE...
VISIBILITIES HAD DROPPED TO A LESS THAN 1 MILE NORTH OF JONESBORO
THIS EVENING. THIS AREA WAS NORTH OF A WEAK SURFACE WARM FRONT
THAT EXTENDED ROUGHLY ALONG INTERSTATE 40. HRRR AND GFS LAMP
GUIDANCE SUGGEST WARM ADVECTION OVER THE NEARLY STATIONARY FRONT
WILL DROP VISIBILITIES LOWER DURING THE OVERNIGHT. WITH TEMPS NEAR
FREEZING...WILL NEED TO MONITOR TEMPS CLOSELY INTO THE EARLY
OVERNIGHT. THEREAFTER...00Z NAM DEPICTS WARMING SURFACE TEMPS WITH
WARM FRONT LIFTING THROUGH.
HRRR DEPICTS ADDITIONAL AREAS OF FOG FORMING IN THE CLEAR SLOT
OVER CENTRAL MS... AND SPREADING NORTH OVERNIGHT. FOR THE 9 PM
UPDATE... HAVE KEPT THE MENTION OF DENSE FOG WEST OF THE MS RIVER...
BUT DENSE FOG CANNOT BE RULED OUT EAST OF THE MS RIVER TOWARD
MORNING...ASSOCIATED WITH A MARINE WARM FRONT LIFTING NORTH.
PWB
&&
.PREV DISCUSSION... /ISSUED 339 PM CST THU JAN 9 2014/
NEAR NORMAL TO SLIGHTLY ABOVE NORMAL TEMPERATURES EXPECTED OVER
MUCH OF THE NEXT SEVEN DAYS.
THE SHORTWAVE THAT HAS CAUSED THE WINTRY MIX AND RAIN TODAY IS
PUSHING OUT OF THE MIDSOUTH. HOWEVER EXPECT SMALL CHANCES OF RAIN
WILL CONTINUE TONIGHT INTO FRIDAY AS WARM AIR ADVECTION MAY
PRODUCE SOME LIGHT SHOWERS ACROSS THE AREA. LOWS WILL ACTUALLY
OCCUR THIS EVENING DUE TO THE WARM AIR ADVECTION TONIGHT.
TEMPERATURES WILL SLOWLY RISE OVERNIGHT. THIS MEANS LOWS WILL BE
AT OR ABOVE FREEZING TONIGHT WITH READINGS RANGING FROM THE LOWER
30S TO AROUND 40 DEGREES. HIGHS ON FRIDAY WILL BE IN THE 50S AND
WILL FEEL GREAT AFTER THE EXTREME COLD THAT THE MIDSOUTH HAS
EXPERIENCED.
A COLD FRONT WILL MOVE THROUGH THE MIDSOUTH FRIDAY NIGHT. BETTER
CHANCES FOR SHOWERS WILL OCCUR AS A RESULT. ALSO...CAN/T RULE OUT
A FEW THUNDERSTORMS OCCURRING ACROSS NORTH MISSISSIPPI. DO NOT REALLY EXPECT
MUCH IF ANY COOL DOWN AT ALL BEHIND THE FRONT AS IT IS MORE OF A PACIFIC
ORIGIN FRONT THAN AN ARCTIC FRONT.
HIGH PRESSURE WILL SETTLE OVER THE REGION FOR THE WEEKEND. A NICE
WARMING TREND IS EXPECTED ON SUNDAY AS THE HIGH SHIFTS EAST AND
WINDS TURN AROUND TO THE SOUTH. AS A RESULT...HIGHS WILL GET INTO
THE LOWER TO MID 60S IN MANY LOCATIONS.
A COLD FRONT WILL MOVE THROUGH SUNDAY NIGHT. THE GFS HAS LITTLE
PRECIPITATION WITH THE FRONT WHILE THE ECMWF DEVELOPS A SFC LOW
ALONG THE FRONT. AS A RESULT...THE MODEL PRODUCES QUITE A BIT OF
QPF ACROSS THE AREA WITH BEST CHANCES OCCURRING ACROSS NORTHEAST
MISSISSIPPI. HAVE TRIED TO GO WITH AN IN BETWEEN SOLUTION FOR NOW.
HIGH PRESSURE WILL RETURN ON MONDAY AND MONDAY NIGHT. HOWEVER A
REINFORCING FRONT WILL MOVE THROUGH ON TUESDAY AND WILL BRING COLDER
AIR INTO THE AREA. HOW COLD THE AIR WILL BE DEPENDS ON WHICH MODEL
YOU LOOK AT. THE ECMWF IS MUCH COLDER THAN THE GFS. AGAIN HAVE
TRIED TO IN BETWEEN FOR TEMPERATURES FROM TUESDAY AND BEYOND AS
RESULT OF THE DIFFERENT SOLUTIONS. HIGH PRESSURE WILL RETURN TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT.
ANOTHER COLD FRONT WILL APPROACH ON THURSDAY.
KRM
&&
.AVIATION...
06Z TAF CYCLE
A WEAK SURFACE BOUNDARY REMAINS STRETCHED ACROSS SOUTHEAST
ARKANSAS INTO WEST TENNESSEE ROUGHLY JUST NORTH OF THE I-40
CORRIDOR. LIFR OR LOWER CIGS AND REDUCED VSBYS PERSIST NORTH OF THE
BOUNDARY AT KJBR AND SHOULD REMAIN IN PLACE THROUGH MUCH OF THE
NIGHT. SOUTH OF THE BOUNDARY TO INCLUDE KMEM AND KMKL...LOW
STRATUS HAS SCATTERED OUT WITH LIGHT SOUTHEAST WINDS AND
A RETURN TO VFR CIGS/VSBYS EXPECTED UNTIL LATER TONIGHT. BEYOND
10Z...EXPECT LOW STRATUS AND FOG TO RETURN AS MOISTURE ADVECTS
FROM THE SOUTH WITHIN WEAK ISENTROPIC ASCENT. LOW STRATUS WILL
LIKELY INVADE KTUP WITHIN THE NEXT FEW HOURS ALONG WITH FOG
DROPPING CIGS TO LIFR ALONG WITH REDUCED VSBYS. SCATTERED SHOWERS
WILL BE POSSIBLE AS WELL OVERNIGHT AT KMEM AND KMKL WITH DRIZZLE
POSSIBLE AT KJBR.
CIGS SHOULD SLOWLY RISE WITH THE PASSAGE OF A SECONDARY WARM
FRONT FRIDAY MORNING AT KMEM...KTUP...AND KMKL...BEFORE LOWERING
AGAIN TOWARDS THE END OF THE PERIOD WITH THE APPROACH OF THE NEXT
SHORTWAVE. FURTHER NORTH AT KJBR...CIGS AND VSBYS WILL STRUGGLE TO
RISE AND SHOULD REMAIN QUITE LOW THROUGH THE TAF PERIOD. A PERIOD
OF SHOWERS IS POSSIBLE WITH THE WARM FRONT IN THE MORNING AT
KMEM...KTUP...AND KMKL. THERE SHOULD THEN BE A BREAK FOR A FEW
HOURS BEFORE MORE RAIN DEVELOPS TOWARDS THE END OF THE PERIOD WITH
APPROACHING SHORTWAVE FROM THE WEST. AT KJBR...RAIN CHANCES SHOULD
CONTINUE THROUGH MUCH OF FRIDAY DUE TO CLOSE PROXIMITY OF THE
FRONT AND EVENTUAL INFLUENCE FROM UPPER WAVE AS WELL BY AFTERNOON.
WINDS SHOULD EVENTUALLY GO SOUTHERLY EVERYWHERE ON FRIDAY AND
INCREASE IN SPEEDS WITH APPROACH OF WESTERN DISTURBANCE ALOFT.
WIDESPREAD RAIN AND A FEW THUNDERSTORMS CAN BE EXPECTED AT ALL
TERMINALS FRIDAY EVENING WITH IFR OR LOWER CIGS EXPECTED.
JLH
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 42 57 45 57 / 30 50 100 10
MKL 39 56 46 56 / 20 40 100 10
JBR 34 50 36 52 / 30 70 100 10
TUP 46 58 52 62 / 20 30 100 20
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...DENSE FOG ADVISORY UNTIL 8 AM CST FRIDAY FOR CLAY-CRAIGHEAD-
CRITTENDEN-CROSS-GREENE-LAWRENCE-MISSISSIPPI-POINSETT-
RANDOLPH-ST. FRANCIS.
MO...DENSE FOG ADVISORY UNTIL 8 AM CST FRIDAY FOR DUNKLIN-PEMISCOT.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
927 PM EST SAT JAN 11 2014
.SYNOPSIS...
A COLD FRONT WILL PROGRESS ACROSS THE AREA THIS EVENING AND BE
WELL OFF THE ATLANTIC COAST BY SUNDAY MORNING. HIGH PRESSURE WILL
BUILD INTO THE REGION FOR THE REMAINDER OF THE WEEKEND. A WARM
FRONT WILL LIFT ACROSS THE AREA ON MONDAY...FOLLOWED BY A COLD
FRONT ON TUESDAY INTO WEDNESDAY.
&&
.NEAR TERM /THROUGH SUNDAY/...
AS OF 920 PM EST SATURDAY...
A FEW OF THE SHOWERS ALONG AND AHEAD OF THE FRONT ARE GROWING TALL
ENOUGH TO BECOME THUNDERSTORMS AND PRODUCE SOME SMALL HAIL. HAVE
BEEN ACCOUNTING FOR THIS IN SPECIAL WEATHER STATEMENTS. THE LATEST
FORECAST UPDATE WILL INCLUDE THIS POTENTIAL AS WELL FOR THE NEXT
HOUR OR TWO. NO MAJOR ADDITIONAL ADJUSTMENTS AT THIS TIME. HAVE
ONLY TWEAKED HOURLY TEMPERATURES AND DEW POINTS TO REFLECT THE
LATEST OBSERVATIONS AND EXPECTED TRENDS INTO THE EARLY MORNING
HOURS.
AS OF 650 PM EST SATURDAY...
SHOWERS ALONG THE COLD FRONT ARE CONTINUING TO PROGRESS EASTWARD
THROUGH THE AREA. A LOOK AT THE LOCAL WRF AND HRRR MODELS ARE
CAPTURING THIS ACTIVITY...AND OFFER A SOLUTION THAT BRINGS AT
LEAST ISOLATED COVERAGE ACROSS THE ENTIRE REGION COINCIDENT TO THE
FRONT. HAVE UPDATED THE FORECAST TO REFLECT THIS. NO OTHER
SIGNIFICANT CHANGES HAVE BEEN MADE.
AS OF 525 PM EST SATURDAY...
INSTABILITY HAS DEVELOPED IN THE DRY SLOT IMMEDIATELY COINCIDENT
TO THE COLD FRONT. ENOUGH HEATING HAS ALLOWED FOR SOME SCATTERED
SHOWERS TO DEVELOP OVER WEST VIRGINIA THAT ARE PROGRESSING INTO
THE WESTERN PORTION OF THE FORECAST AREA. AM NOT ANTICIPATING THE
SHOWERS TO MAKE A LOT OF PROGRESS AND DISSIPATE AROUND SUNSET.
AS OF 315 PM EST SATURDAY...
A COLD FRONT WAS ABOUT TO ENTER THE WESTERN PORTIONS OF THE FORECAST
AREA. PRECIPITATION HEAD OF IT WAS BECOMING CONFINED TO PRIMARILY
THE EASTERN HALF OF THE REGION AND PROGRESSING EASTWARD VERY
QUICKLY. ANTICIPATE THAT THE BACK EDGE OF THE PRECIPITATION WILL
EXIT THE EASTERN PART OF THE FORECAST AREA BY 800 PM EST. BEHIND THE
COLD FRONT...WINDS WILL SHIFT NORTHWEST AND BECOME GUSTY THROUGH THE
OVERNIGHT HOURS...ESPECIALLY ACROSS THE MOUNTAINS. 850 MB WINDS ARE
PROGGED TO PEAK BETWEEN 45 AND 50 KTS WITH AN ORIENTATION THAT GIVES
GOOD CROSS-BARRIER FLOW. WE ARE EXPECTED WIND ADVISORY CRITERIA
GUSTS ACROSS THE HIGHER TERRAIN OF THE NORTHERN MOUNTAINS OF NORTH
CAROLINA...NORTH INTO GRAYSON COUNTY VIRGINIA. THE PRESSURE GRADIENT
AND SUBSEQUENT 850 WINDS ARE PROGGED TO DECREASE QUICKLY DURING THE
FORENOON SUNDAY...THUS THE 900 PM END TIME FOR THE ADVISORY. THESE
SAME NORTHWEST WINDS WILL BE WEAKER ACROSS THE PIEDMONT...AND HELP
TO ERODE THE CLOUD COVER THANKS TO THE GENERATED SUBSIDENCE.
THE NORTHWEST FLOW AND LINGERING LOW LEVEL MOISTURE WILL HELP TO
GENERATE SOME UPSLOPE PRECIPITATION ACROSS SOUTHEAST WEST VIRGINIA
SOUTH INTO THE NORTHERN MOUNTAINS OF NORTH CAROLINA. WHILE WE WILL
MENTION SOME SNOW SHOWERS WHERE TEMPERATURES FALL LOW
ENOUGH...CONFIDENCE IN SNOW OCCURRING IS NOT VERY HIGH. PLENTY OF
DRY AIR WILL WORK INTO THE AREA BETWEEN ROUGHLY THE -6 C TO -25 C
RANGE...SO THERE LIKELY WILL NOT BE ANY ICE CRYSTALS FOR DENTRITIC
GROWTH. WILL MENTION THE POTENTIAL FOR DRIZZLE OR FREEZING DRIZZLE
GIVEN THE LOCAL TEMPERATURE. HOWEVER...HIGH LEVEL CLOUD COVER ABOVE
THIS DRY LAYER MAY HELP TO PROVIDE FOR SOME SEEDER FEEDER SNOW
PRODUCTION...BUT THE POTENTIAL FOR THAT IS ALSO ON THE LOW SIDE.
HAVE GONE FAIRLY CLOSE TO GUIDANCE ADJUSTED FOR LOCAL BIASES FOR THE
OVERNIGHT LOWS. THIS OFFERS LOWS OF THE LOW TO MID 30S OVER THE
MOUNTAINS WITH MID TO UPPER 30S ACROSS THE PIEDMONT.
ON SUNDAY...THE NORTHWEST WINDS WILL CONTINUE THROUGH ABOUT MIDDAY
BEFORE THEY WEAKEN AND BACK SOUTHWEST AS AN UPPER RIDGE STARTS TO
DEVELOP OVER THE REGION. WE EXPECT PLENTY OF DRY AIR TO CONTINUE
ADVECTING INTO THE AREA...AND THE TREND FOR ERODING CLOUD COVER WILL
TAKE PLACE ACROSS THE MOUNTAINS. HAVE FAVORED A BLEND OF THE MAV AND
MET MOS NUMBERS ADJUSTED FOR LOCAL BIASES FOR THE HIGH TEMPERATURES.
THIS WILL PLACE MID TO UPPER 40S ACROSS MOST OF THE MOUNTAIN
COUNTIES AND LOW TO MID 50S ACROSS THE PIEDMONT.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
AS OF 300 PM EST SATURDAY...
WILL START SUNDAY EVENING WITH A WEAK UPPER LEVEL RIDGE CROSSING THE
APPALACHIANS...WHILE HIGH PRESSURE IN THE LOW LEVELS MOVES OFFSHORE
FROM THE SOUTHEASTERN STATES. SOUTHWESTERLY FLOW AROUND THE
DEPARTING HIGH WILL DRAW WARM GULF AIR INTO OUR REGION...PUSHING
MONDAY AFTERNOON HIGHS INTO THE MID TO UPPER 50S FOR MOST
LOCATIONS... SEVERAL DEGREES ABOVE SEASONAL NORMALS.
THE UPPER RIDGE WILL BE MAKING A QUICK EXIT MONDAY AFTERNOON...IN
FAVOR OF AN UPPER LEVEL TROUGH AND ASSOCIATED COOL FRONT APPROACHING
FROM THE UPPER MIDWEST. LATEST FORECAST MODELS INDICATE THE TROUGH
IS NOT AS SHARP OR NEGATIVELY TILTED AS INDICATED IN PREVIOUS MODEL
RUNS...AND AM NO LONGER CONTEMPLATING THE POSSIBILITY OF
THUNDERSTORMS ACROSS THE SOUTHSIDE MONDAY NIGHT. PRECIPITATION IS A
GOOD BET HOWEVER...AND TEMPERATURES WILL BE WARM ENOUGH THROUGH THE
NIGHT TO SUPPORT RAIN.
THE COOL FRONT WILL PUSH THROUGH THE REGION EARLY TUESDAY MORNING...
BRINGING TUESDAY AFTERNOON HIGHS CLOSER TO SEASONAL NORMALS. WILL
SEE BRIEF PERIOD OF MAINLY DRY WEATHER TUESDAY AFTERNOON...BEFORE
OUR NEXT UPPER LEVEL TROUGH AND ASSOCIATED COLD FRONT ARRIVE TUESDAY
NIGHT. THIS TROUGH WILL BE COLDER THAN THE PREVIOUS SYSTEM
AND...WHILE THERE WILL NOT BE A GREAT DEAL OF MOISTURE FOR IT TO
WORK WITH...IS EXPECTED TO CAUSE RAIN SHOWERS TO CHANGE OVER TO SNOW
IN THE MOUNTAINS DURING THE EARLY MORNING HOURS OF WEDNESDAY. ANY
SNOW ACCUMULATIONS ARE EXPECTED TO BE LIGHT...AND CONFINED TO MAINLY
THE HIGHER RIDGES IN SOUTHEAST WEST VIRGINIA.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 300 PM EST SATURDAY...
POLAR VORTEX/EASTERN U.S. TROUGHING WILL PREVAIL DURING THE MEDIUM
RANGE. NORTHWEST FLOW ALOFT WILL DOMINATE THROUGH THE MUCH OF THE
PERIOD...AS THE MAIN TROUGH AXIS GRADUALLY PIVOTS NORTHEAST OF THE
REGION. A COUPLE OF ALBERTA CLIPPERS WILL ROTATE EASTWARD THROUGH
THE MEAN TROUGH WITH LIMITED MOISTURE. IN GENERAL...EXPECT
SEASONABLY COOL TEMPERATURES THROUGH THE PERIOD. UPSLOPE CLOUDS AND
COLDER TEMPERATURES ARE ON TAP FOR THE MOUNTAINS...WHILE SUNSHINE
WILL RESULT IN WARMER READINGS FOR THE EAST. KEPT THE HIGHEST POPS
ON WEDNESDAY IN THE NORTHWEST AS A WAVE TRAVEL ACROSS REGION. STILL
LOOK LIKE MOST OF THE MOISTURE WILL RIDE NORTHEAST OF OUR AREA. THE
FRONT PUSHES OFF TO THE EAST AND A DRY HIGH PRESSURE BUILDS IN FROM
THE WEST BY THURSDAY. ANOTHER MOISTURE-STARVED SURFACE COLD FRONT
WITH ARRIVES AROUND FRIDAY...FOLLOWED BY HIGH PRESSURE ON SATURDAY.
&&
.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
AS OF 635 PM EST SATURDAY...
A COLD FRONT IS CURRENTLY MOVING THROUGH THE REGION...VERY NEAR A
KBLF-KHSP LINE. SCATTERED SHOWERS HAVE DEVELOPED ALONG THE
FRONT...AND ARE PROGRESSING EASTWARD ACROSS THE AREA. ANTICIPATE
AT LEAST SOME ISOLATED COVERAGE TO ACCOMPANY THE FRONT THROUGH THE
FORECAST AREA...BUT THE GREATEST COVERAGE WILL CONTINUE EASTWARD
TO THE CREST OF THE BLUE RIDGE. SKY COVER OVERNIGHT WILL TREND TO
VFR EAST OF THE CREST OF THE RIDGE THANKS TO GOOD DOWNSLOPING.
ACROSS THE MOUNTAINS A MIX OF MVFR AND LOW AND VFR CLOUDS ARE
EXPECTED. SOME LIGHT SNOW OR DRIZZLE OR FREEZING DRIZZLE IS
POSSIBLE ACROSS SOUTHEAST WEST VIRGINIA SOUTH INTO THE NORTHERN
MOUNTAINS OF NORTH CAROLINA. ALL AREAS ARE EXPECTED TO BE VFR BY
LATE SUNDAY MORNING. GUSTY NORTHWEST WINDS WILL PREVAIL ACROSS THE
MOUNTAINS OVERNIGHT WITH THE HIGHER PEAKS APPROACHING 40 TO 45
KTS. WINDS WILL DECREASE THROUGH THE DAY SUNDAY...AND LOW LEVEL
WINDS BACK AND AN UPPER RIDGE STARTS TO BUILD OVER THE AREA.
AS OF 110 PM EST SATURDAY...
THE NEXT LOW PRESSURE SYSTEM IS PROJECTED TO ARRIVE BY MONDAY
NIGHT INTO TUESDAY MORNING...WHICH WOULD BRING SOME MVFR
CONDITIONS AND RAIN SHOWERS IN THE PIEDMONT...WITH A FEW SNOW
SHOWERS POSSIBLE IN THE MOUNTAINS. THE LONG RANGE MODELS SHOW A
SMALL CLIPPER SYSTEM TRACKING OVER THE MID ATLANTIC BY TUESDAY
NIGHT INTO WEDNESDAY. SOME UNCERTAINTY STILL EXISTS WITH THIS
COMPACT FEATURE...BUT IT WILL BE WORTH WATCHING AS SOME
ACCUMULATING SNOW MAY OCCUR FOR BLF/LWB ON WEDNESDAY...AND EVEN
BCB/ROA MAY SEE A FEW SNOW SHOWERS. OTHERWISE...VFR CONDITIONS
SHOULD PREVAIL ACROSS THE PIEDMONT FOR MOST OF NEXT WEEK...WHILE
MVFR CONDITIONS MAY BE MORE LIKELY IN THE MOUNTAINS DURING
WEDNESDAY AND THURSDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WIND ADVISORY UNTIL 9 AM EST SUNDAY FOR VAZ015.
NC...WIND ADVISORY UNTIL 9 AM EST SUNDAY FOR NCZ001-018.
WV...NONE.
&&
$$
SYNOPSIS...DS
NEAR TERM...DS
SHORT TERM...NF
LONG TERM...KK
AVIATION...DS/PW
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
652 PM EST SAT JAN 11 2014
.SYNOPSIS...
A COLD FRONT WILL PROGRESS ACROSS THE AREA THIS EVENING AND BE
WELL OFF THE ATLANTIC COAST BY SUNDAY MORNING. HIGH PRESSURE WILL
BUILD INTO THE REGION FOR THE REMAINDER OF THE WEEKEND. A WARM
FRONT WILL LIFT ACROSS THE AREA ON MONDAY...FOLLOWED BY A COLD
FRONT ON TUESDAY INTO WEDNESDAY.
&&
.NEAR TERM /THROUGH SUNDAY/...
AS OF 650 PM EST SATURDAY...
SHOWERS ALONG THE COLD FRONT ARE CONTINUING TO PROGRESS EASTWARD
THROUGH THE AREA. A LOOK AT THE LOCAL WRF AND HRRR MODELS ARE
CAPTURING THIS ACTIVITY...AND OFFER A SOLUTION THAT BRINGS AT
LEAST ISOLATED COVERAGE ACROSS THE ENTIRE REGION COINCIDENT TO THE
FRONT. HAVE UPDATED THE FORECAST TO REFLECT THIS. NO OTHER
SIGNIFICANT CHANGES HAVE BEEN MADE.
AS OF 525 PM EST SATURDAY...
INSTABILITY HAS DEVELOPED IN THE DRY SLOT IMMEDIATELY COINCIDENT
TO THE COLD FRONT. ENOUGH HEATING HAS ALLOWED FOR SOME SCATTERED
SHOWERS TO DEVELOP OVER WEST VIRGINIA THAT ARE PROGRESSING INTO
THE WESTERN PORTION OF THE FORECAST AREA. AM NOT ANTICIPATING THE
SHOWERS TO MAKE A LOT OF PROGRESS AND DISSIPATE AROUND SUNSET.
AS OF 315 PM EST SATURDAY...
A COLD FRONT WAS ABOUT TO ENTER THE WESTERN PORTIONS OF THE FORECAST
AREA. PRECIPITATION HEAD OF IT WAS BECOMING CONFINED TO PRIMARILY
THE EASTERN HALF OF THE REGION AND PROGRESSING EASTWARD VERY
QUICKLY. ANTICIPATE THAT THE BACK EDGE OF THE PRECIPITATION WILL
EXIT THE EASTERN PART OF THE FORECAST AREA BY 800 PM EST. BEHIND THE
COLD FRONT...WINDS WILL SHIFT NORTHWEST AND BECOME GUSTY THROUGH THE
OVERNIGHT HOURS...ESPECIALLY ACROSS THE MOUNTAINS. 850 MB WINDS ARE
PROGGED TO PEAK BETWEEN 45 AND 50 KTS WITH AN ORIENTATION THAT GIVES
GOOD CROSS-BARRIER FLOW. WE ARE EXPECTED WIND ADVISORY CRITERIA
GUSTS ACROSS THE HIGHER TERRAIN OF THE NORTHERN MOUNTAINS OF NORTH
CAROLINA...NORTH INTO GRAYSON COUNTY VIRGINIA. THE PRESSURE GRADIENT
AND SUBSEQUENT 850 WINDS ARE PROGGED TO DECREASE QUICKLY DURING THE
FORENOON SUNDAY...THUS THE 900 PM END TIME FOR THE ADVISORY. THESE
SAME NORTHWEST WINDS WILL BE WEAKER ACROSS THE PIEDMONT...AND HELP
TO ERODE THE CLOUD COVER THANKS TO THE GENERATED SUBSIDENCE.
THE NORTHWEST FLOW AND LINGERING LOW LEVEL MOISTURE WILL HELP TO
GENERATE SOME UPSLOPE PRECIPITATION ACROSS SOUTHEAST WEST VIRGINIA
SOUTH INTO THE NORTHERN MOUNTAINS OF NORTH CAROLINA. WHILE WE WILL
MENTION SOME SNOW SHOWERS WHERE TEMPERATURES FALL LOW
ENOUGH...CONFIDENCE IN SNOW OCCURRING IS NOT VERY HIGH. PLENTY OF
DRY AIR WILL WORK INTO THE AREA BETWEEN ROUGHLY THE -6 C TO -25 C
RANGE...SO THERE LIKELY WILL NOT BE ANY ICE CRYSTALS FOR DENTRITIC
GROWTH. WILL MENTION THE POTENTIAL FOR DRIZZLE OR FREEZING DRIZZLE
GIVEN THE LOCAL TEMPERATURE. HOWEVER...HIGH LEVEL CLOUD COVER ABOVE
THIS DRY LAYER MAY HELP TO PROVIDE FOR SOME SEEDER FEEDER SNOW
PRODUCTION...BUT THE POTENTIAL FOR THAT IS ALSO ON THE LOW SIDE.
HAVE GONE FAIRLY CLOSE TO GUIDANCE ADJUSTED FOR LOCAL BIASES FOR THE
OVERNIGHT LOWS. THIS OFFERS LOWS OF THE LOW TO MID 30S OVER THE
MOUNTAINS WITH MID TO UPPER 30S ACROSS THE PIEDMONT.
ON SUNDAY...THE NORTHWEST WINDS WILL CONTINUE THROUGH ABOUT MIDDAY
BEFORE THEY WEAKEN AND BACK SOUTHWEST AS AN UPPER RIDGE STARTS TO
DEVELOP OVER THE REGION. WE EXPECT PLENTY OF DRY AIR TO CONTINUE
ADVECTING INTO THE AREA...AND THE TREND FOR ERODING CLOUD COVER WILL
TAKE PLACE ACROSS THE MOUNTAINS. HAVE FAVORED A BLEND OF THE MAV AND
MET MOS NUMBERS ADJUSTED FOR LOCAL BIASES FOR THE HIGH TEMPERATURES.
THIS WILL PLACE MID TO UPPER 40S ACROSS MOST OF THE MOUNTAIN
COUNTIES AND LOW TO MID 50S ACROSS THE PIEDMONT.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
AS OF 300 PM EST SATURDAY...
WILL START SUNDAY EVENING WITH A WEAK UPPER LEVEL RIDGE CROSSING THE
APPALACHIANS...WHILE HIGH PRESSURE IN THE LOW LEVELS MOVES OFFSHORE
FROM THE SOUTHEASTERN STATES. SOUTHWESTERLY FLOW AROUND THE
DEPARTING HIGH WILL DRAW WARM GULF AIR INTO OUR REGION...PUSHING
MONDAY AFTERNOON HIGHS INTO THE MID TO UPPER 50S FOR MOST
LOCATIONS... SEVERAL DEGREES ABOVE SEASONAL NORMALS.
THE UPPER RIDGE WILL BE MAKING A QUICK EXIT MONDAY AFTERNOON...IN
FAVOR OF AN UPPER LEVEL TROUGH AND ASSOCIATED COOL FRONT APPROACHING
FROM THE UPPER MIDWEST. LATEST FORECAST MODELS INDICATE THE TROUGH
IS NOT AS SHARP OR NEGATIVELY TILTED AS INDICATED IN PREVIOUS MODEL
RUNS...AND AM NO LONGER CONTEMPLATING THE POSSIBILITY OF
THUNDERSTORMS ACROSS THE SOUTHSIDE MONDAY NIGHT. PRECIPITATION IS A
GOOD BET HOWEVER...AND TEMPERATURES WILL BE WARM ENOUGH THROUGH THE
NIGHT TO SUPPORT RAIN.
THE COOL FRONT WILL PUSH THROUGH THE REGION EARLY TUESDAY MORNING...
BRINGING TUESDAY AFTERNOON HIGHS CLOSER TO SEASONAL NORMALS. WILL
SEE BRIEF PERIOD OF MAINLY DRY WEATHER TUESDAY AFTERNOON...BEFORE
OUR NEXT UPPER LEVEL TROUGH AND ASSOCIATED COLD FRONT ARRIVE TUESDAY
NIGHT. THIS TROUGH WILL BE COLDER THAN THE PREVIOUS SYSTEM
AND...WHILE THERE WILL NOT BE A GREAT DEAL OF MOISTURE FOR IT TO
WORK WITH...IS EXPECTED TO CAUSE RAIN SHOWERS TO CHANGE OVER TO SNOW
IN THE MOUNTAINS DURING THE EARLY MORNING HOURS OF WEDNESDAY. ANY
SNOW ACCUMULATIONS ARE EXPECTED TO BE LIGHT...AND CONFINED TO MAINLY
THE HIGHER RIDGES IN SOUTHEAST WEST VIRGINIA.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 300 PM EST SATURDAY...
POLAR VORTEX/EASTERN U.S. TROUGHING WILL PREVAIL DURING THE MEDIUM
RANGE. NORTHWEST FLOW ALOFT WILL DOMINATE THROUGH THE MUCH OF THE
PERIOD...AS THE MAIN TROUGH AXIS GRADUALLY PIVOTS NORTHEAST OF THE
REGION. A COUPLE OF ALBERTA CLIPPERS WILL ROTATE EASTWARD THROUGH
THE MEAN TROUGH WITH LIMITED MOISTURE. IN GENERAL...EXPECT
SEASONABLY COOL TEMPERATURES THROUGH THE PERIOD. UPSLOPE CLOUDS AND
COLDER TEMPERATURES ARE ON TAP FOR THE MOUNTAINS...WHILE SUNSHINE
WILL RESULT IN WARMER READINGS FOR THE EAST. KEPT THE HIGHEST POPS
ON WEDNESDAY IN THE NORTHWEST AS A WAVE TRAVEL ACROSS REGION. STILL
LOOK LIKE MOST OF THE MOISTURE WILL RIDE NORTHEAST OF OUR AREA. THE
FRONT PUSHES OFF TO THE EAST AND A DRY HIGH PRESSURE BUILDS IN FROM
THE WEST BY THURSDAY. ANOTHER MOISTURE-STARVED SURFACE COLD FRONT
WITH ARRIVES AROUND FRIDAY...FOLLOWED BY HIGH PRESSURE ON SATURDAY.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
AS OF 635 PM EST SATURDAY...
A COLD FRONT IS CURRENTLY MOVING THROUGH THE REGION...VERY NEAR A
KBLF-KHSP LINE. SCATTERED SHOWERS HAVE DEVELOPED ALONG THE
FRONT...AND ARE PROGRESSING EASTWARD ACROSS THE AREA. ANTICIPATE
AT LEAST SOME ISOLATED COVERAGE TO ACCOMPANY THE FRONT THROUGH THE
FORECAST AREA...BUT THE GREATEST COVERAGE WILL CONTINUE EASTWARD
TO THE CREST OF THE BLUE RIDGE. SKY COVER OVERNIGHT WILL TREND TO
VFR EAST OF THE CREST OF THE RIDGE THANKS TO GOOD DOWNSLOPING.
ACROSS THE MOUNTAINS A MIX OF MVFR AND LOW AND VFR CLOUDS ARE
EXPECTED. SOME LIGHT SNOW OR DRIZZLE OR FREEZING DRIZZLE IS
POSSIBLE ACROSS SOUTHEAST WEST VIRGINIA SOUTH INTO THE NORTHERN
MOUNTAINS OF NORTH CAROLINA. ALL AREAS ARE EXPECTED TO BE VFR BY
LATE SUNDAY MORNING. GUSTY NORTHWEST WINDS WILL PREVAIL ACROSS THE
MOUNTAINS OVERNIGHT WITH THE HIGHER PEAKS APPROACHING 40 TO 45
KTS. WINDS WILL DECREASE THROUGH THE DAY SUNDAY...AND LOW LEVEL
WINDS BACK AND AN UPPER RIDGE STARTS TO BUILD OVER THE AREA.
AS OF 110 PM EST SATURDAY...
THE NEXT LOW PRESSURE SYSTEM IS PROJECTED TO ARRIVE BY MONDAY
NIGHT INTO TUESDAY MORNING...WHICH WOULD BRING SOME MVFR
CONDITIONS AND RAIN SHOWERS IN THE PIEDMONT...WITH A FEW SNOW
SHOWERS POSSIBLE IN THE MOUNTAINS. THE LONG RANGE MODELS SHOW A
SMALL CLIPPER SYSTEM TRACKING OVER THE MID ATLANTIC BY TUESDAY
NIGHT INTO WEDNESDAY. SOME UNCERTAINTY STILL EXISTS WITH THIS
COMPACT FEATURE...BUT IT WILL BE WORTH WATCHING AS SOME
ACCUMULATING SNOW MAY OCCUR FOR BLF/LWB ON WEDNESDAY...AND EVEN
BCB/ROA MAY SEE A FEW SNOW SHOWERS. OTHERWISE...VFR CONDITIONS
SHOULD PREVAIL ACROSS THE PIEDMONT FOR MOST OF NEXT WEEK...WHILE
MVFR CONDITIONS MAY BE MORE LIKELY IN THE MOUNTAINS DURING
WEDNESDAY AND THURSDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WIND ADVISORY UNTIL 9 AM EST SUNDAY FOR VAZ015.
NC...WIND ADVISORY UNTIL 9 AM EST SUNDAY FOR NCZ001-018.
WV...NONE.
&&
$$
SYNOPSIS...DS
NEAR TERM...DS
SHORT TERM...NF
LONG TERM...KK
AVIATION...DS/PW
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
206 PM CST FRI JAN 10 2014
.SHORT TERM...(TONIGHT THROUGH SATURDAY NIGHT)
ISSUED AT 206 PM CST FRI JAN 10 2014
MAIN CONCERNS IN THE SHORT TERM WILL BE DEALING WITH WINTRY MIX INTO
TONIGHT. A WINTER WEATHER ADVISORY IS IN EFFECT UNTIL 6 AM SATURDAY.
WATER VAPOR IMAGERY SHOWING A DEEP MID-LEVEL TROUGH MOVING ACROSS
CENTRAL CONUS AT THIS TIME. AT THE SURFACE...A TROUGH EXTENDED FROM
ALONG THE DAKOTAS/MN BORDER...INTO EASTERN NEBRASKA/KANSAS. THESE
FEATURES WERE PRODUCING ISENTROPIC LIFT AND MOISTURE TRANSPORT INTO
THE AREA FOR A WINTRY MIX OF PRECIPITATION AT GROUND LEVEL. RADAR
SHOWING RETURNS ACROSS THE ENTIRE AREA WITH AREAS OF MAINLY DRIZZLE
AND FREEZING DRIZZLE BEING REPORTED. SOME SLEET WAS ALSO SHOWING UP
ACROSS PARTS OF NORTHEAST IA. OTHERWISE...TEMPERATURES ACROSS THE
AREA RANGED FROM THE MIDDLE 20S ACROSS NORTH CENTRAL WI...TO THE
LOWER 30S ACROSS NORTHEAST IA INTO FAR SOUTHWEST WI.
LOOK FOR THE MID-LEVEL/SURFACE TROUGH TO MOVE EAST THROUGH THE AREA
TONIGHT...WITH MOST OF THE PRECIPITATION CHANGING OVER TO LIGHT SNOW
THIS EVENING. THE ONLY EXCEPTION WILL BE ACROSS PORTIONS OF
NORTHEAST IA INTO FAR SOUTHWEST AND CENTRAL WI WHERE THERE WILL BE
LACK OF ICE ISSUES IN THE COLUMN AND WARMER AIR ALOFT. SO...A
MIXTURE OF DRIZZLE...FREEZING DRIZZLE...SLEET AND LIGHT SNOW WILL
STILL BE POSSIBLE THERE. WHERE THE SNOW FALLS...GENERALLY ALONG AND
NORTHWEST OF A TOMAH/LA CROSSE/OELWEIN LINE...PERHAPS 1/2-1 INCH IS
POSSIBLE. OF NOTE IS THE RAP SHOWING LOSS OF ICE IN THE CLOUD AGAIN
AFTER MIDNIGHT...HINTING AT THE POSSIBILITY OF MIXING WITH OR
CHANGING OVER TO LIGHT FREEZING DRIZZLE OVERNIGHT. WITH THIS IN
MIND...WILL KEEP WINTER WEATHER ADVISORY GOING THROUGH 6 AM
SATURDAY. OVERNIGHT LOWS ARE EXPECTED TO DIP INTO THE 20S.
MAY STILL BE SOME LIGHT SNOW/FLURRY ACTIVITY EARLY ON SATURDAY
MORNING...BUT LOOKING FOR ANY LINGERING PRECIPITATION TO SHIFT OFF
TO THE EAST BY NOON AS A RIDGE OF HIGH PRESSURE BUILDS IN FROM THE
PLAINS. AREAS WEST OF THE MISSISSIPPI WILL LIKELY SEE A GOOD AMOUNT
OF SUNSHINE BY AFTERNOON WITH CLEARING PUSHING EAST OF THE
MISSISSIPPI LATER IN THE AFTERNOON. HIGHS ON SATURDAY EXPECTED TO
RISE INTO THE UPPER 20S TO LOWER 30S.
RIDGE OF HIGH PRESSURE WILL CONTINUE TO MOVE EAST ACROSS THE AREA
SATURDAY NIGHT FOR QUIET WEATHER CONDITIONS. WILL SEE SOME INCREASE
IN MID/HIGH LEVEL CLOUDS THOUGH AHEAD OF A WARM FRONT PUSHING EAST
OUT OF THE NORTHERN/CENTRAL PLAINS. OVERNIGHT LOWS WILL BE IN THE
LOWER TO MIDDLE TEENS.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 206 PM CST FRI JAN 10 2014
MILDER PACIFIC ORIGIN AIR WILL PUSH INTO THE AREA ON SUNDAY WITH
HIGHS EXPECTED TO TOP OFF IN THE LOWER/MIDDLE 30S. UNFORTUNATELY...
INCREASING CLOUD COVER AND SOUTHWEST WINDS IN THE 10 TO 20 MPH RANGE
WILL MAKE IT FEEL MORE LIKE THE LOWER/MIDDLE 20S.
A COLD FRONT WILL THEN PUSH INTO/THROUGH THE AREA SUNDAY NIGHT. THIS
WILL GIVE THE AREA A CHANCE OF A WINTRY MIX WITH A TRICKY THERMAL
PROFILE IN PLACE. COLDER AIR UNDERCUTTING RELATIVELY MILDER AIR
ALOFT MAY PRODUCE A LIGHT WINTRY MIX OF FREEZING RAIN/SLEET/SNOW AS
OVERNIGHT LOWS FALL INTO THE TEENS/LOWER 20S. FORTUNATELY...
PRECIPITATION LOOKS VERY LIGHT...BUT ANY FREEZING PRECIPITATION COULD
CAUSE HEADACHES. WILL CONTINUE TO TO KEEP A CLOSE EYE ON THIS.
COLDER AIR WILL FILTER INTO AREA MONDAY THROUGH TUESDAY AS A DEEP
MID-LEVEL TROUGH CARVES OUT OVER THE CENTRAL CONUS. SOME EMBEDDED
ENERGY WITHIN THE TROUGH WILL GIVE THE AREA A CHANCE FOR LIGHT SNOW
AS WELL. LOOK FOR HIGHS MONDAY AND TUESDAY IN THE 20S WITH LOWS
MONDAY NIGHT IN THE UPPER SINGLE DIGITS AND TEENS.
ANOTHER SHOT AT SOME LIGHT SNOW LOOKS TO OCCUR WEDNESDAY NIGHT INTO
THURSDAY AS WARM AIR ADVECTION TAKES PLACE AHEAD OF LOW PRESSURE
MOVING ACROSS SOUTHERN CANADA. SOME LINGERING LIGHT SNOW OF FLURRY
CHANCES WILL BE SEEN THURSDAY NIGHT AS THE COLD FRONT FROM THIS LOW
PASSES THROUGH.
MUCH COLDER AIR IS ON TAP GOING INTO FRIDAY AS ANOTHER MODIFIED SHOT
OF ARCTIC AIR MAKES ITS WAY INTO THE AREA. HIGHS ARE EXPECTED TO
DROP BACK INTO THE TEENS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1135 AM CST FRI JAN 10 2014
WIDESPREAD IFR CONDITIONS PREVAIL ACROSS THE REGION AND NOT
EXPECTING MUCH CHANGE TO OCCUR UNTIL A COLD FRONT MOVES ACROSS THE
REGION OVERNIGHT. SOME LIGHT FREEZING DRIZZLE OCCURRING WITH THE
LOW CLOUDS AND FOG AND THIS WILL REMAIN A POSSIBILITY THROUGH
ABOUT THE MIDDLE OF THE AFTERNOON. LOOKS LIKE ICE WILL THEN BE
INTRODUCED IN THE CLOUDS TO ALLOW THE FREEZING DRIZZLE TO CHANGE
OVER TO LIGHT SNOW. THIS SNOW SHOULD THEN CONTINUE UNTIL THE FRONT
COMES THROUGH SWINGING THE WINDS AROUND TO THE WEST/NORTHWEST.
SATELLITE CURRENTLY INDICATING SOME CLEARING OCCURRING BEHIND THE
FRONT OVER THE DAKOTAS AND THE BUFKIT SOUNDINGS FROM THE 10.12Z
NAM SUGGEST THIS COULD OCCUR LATE TONIGHT AS WELL. WILL TREND
TOWARD THIS TAKING THE IFR CONDITIONS OUT LATE TONIGHT AND GO TO A
HIGH VFR CEILING WHILE HOLDING ONTO A BIT OF FOG UNTIL THE WIND
CAN COME UP ENOUGH TO MIX THINGS OUT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY UNTIL 6 AM CST SATURDAY FOR WIZ017-029-
034-041>044-053>055-061.
MN...WINTER WEATHER ADVISORY UNTIL 6 AM CST SATURDAY FOR MNZ096.
IA...WINTER WEATHER ADVISORY UNTIL 6 AM CST SATURDAY FOR IAZ010-011-
029-030.
&&
$$
SHORT TERM...DAS
LONG TERM...DAS
AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
504 AM CST FRI JAN 10 2014
.UPDATE...THIS MORNING
ISSUED AT 504 AM CST FRI JAN 10 2014
WITH VISIBILTIIES DETERIORATING RAPIDLY ACROSS THE AREA...DECIDED
TO GO WITH A DENSE FOG ADVISORY FOR MUCH OF THE FORECAST AREA. THE
LONE EXCEPTIONS ARE CLARK AND TAYLOR COUNTIES IN CENTRAL AND NORTH
CENTRAL WISCONSIN. WHILE THE VISIBILITIES ARE STILL MVFR NORTH OF
INTERSTATE 90...EXPECT THESE TO RAPIDLY DETERIORATE AS
TEMPERATURES CONTINUE TO CLIMB ABOVE THE GROUND TEMPERATURE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 402 AM CST FRI JAN 10 2014
AT 4 AM...A SHORT WAVE TROUGH WAS LOCATED OVER THE DAKOTAS.
SOUTHERLY WINDS AND WARM AIR ADVECTION AHEAD OF THIS SYSTEM HAVE
CAUSED THE TEMPERATURES TO SLOWLY RISE OVERNIGHT. VISIBILITIES
HAVE DROPPED TO LESS THAN A MILE ACROSS MUCH OF NORTHEAST IOWA AND
SOUTHEAST MINNESOTA. WE HAVE STARTED TO HEAR OF A FEW ACCIDENTS
DUE TO THE SLICK ROADS. WHILE SOME OF THIS MOISTURE IS BEING
DEPOSITED BY THE FOG AND THE REMAINDER OF IT IS BEING CAUSED BY
THE DEW POINT TEMPERATURES CLIMBING ABOVE THE GROUND TEMPERATURE.
WITH TEMPERATURES BELOW FREEZING THIS MOISTURE IS FREEZING. STILL
DEBATING ON WHETHER TO ISSUE A FREEZING FOG ADVISORY OR A SPECIAL
WEATHER STATEMENT.
LIKE THE 09.18Z MODELS...WITH BOTH THE 270 AND 280K SHOWING VERY
LITTLE LIFT THIS MORNING AND THE BUFKIT SOUNDINGS SHOWING
SUBSIDENCE CO-LOCATED WITH THE LOW LEVEL MOISTURE...NOT EXPECTING
MUCH PRECIPITATION THIS MORNING. DUE TO THIS...DRAMATICALLY
LOWERED THE PRECIPITATION CHANCES FOR THIS MORNING. IF THERE IS
ANY PRECIPITATION IT WILL BE IN THE FORM OF DRIZZLE OR FREEZING
DRIZZLE. THIS PART OF THE FORECAST IS VERY TRICKY BECAUSE IT WILL
BE HIGHLY DEPENDENT UPON HOW MUCH ARE THE ROADS ABLE TO WARM.
DESPITE THE CLOUDS...THE SUN/S INFRARED RADIATION WILL CAUSE THE
ROADS TO WARM UP. OVER THE PAST COUPLE OF DAYS...THE ROADS HAVE
WARMED INTO THE MID AND UPPER 20S DURING THE AFTERNOON. THIS IS
DESPITE THE VERY COLD AIR TEMPERATURES. WITH TEMPERATURES MUCH
WARMER TODAY /LOWER TO MID 30S/...EXPECT THE UNSHELTERED ROADS TO
WARM VERY CLOSE TO THE AIR TEMPERATURE.
FOR THIS AFTERNOON AND EVENING...THE 10.00Z HAVE SHIFTED SOUTH
WITH ITS 500 MB VORTICITY MAXIMUM. AS A RESULT...THE TRACK OF THE
LOW PRESSURE SYSTEM AND ITS PRECIPITATION SHIFTED FURTHER TO THE
SOUTHEAST. DESPITE THE WARM LAYER ALOFT COOLING ALOFT...THERE HAS
ALSO BEEN A LOSS ICE ALOFT IN THE BUFKIT SOUNDINGS. THE -10C
SURFACE SHOWS THAT THE RELATIVE HUMIDITIES FROM CHARLES CITY IOWA
TO WAUSAU ARE AS LOW AS 70 PERCENT. AS A RESULT...EXPECT A BIT
MORE LIQUID THAN SNOW WITH THIS SYSTEM. THIS MORE PROBLEMATIC LATE
THIS AFTERNOON AND EVENING...BECAUSE WE WILL BE LOSING THE LONG
RADIATION FROM THE SUN AND THIS WILL CAUSE THE MANY OF THE ROADS
TO FALL QUICKLY BELOW FREEZING. DUE TO THE MIX PRECIPITATION AND A
FURTHER SOUTHEAST SHIFT IN THE PRECIPITATION...LOWERED THE SNOW
AMOUNTS INTO THE 1 TO 3 INCH RANGE. ICING WILL BE GENERALLY LESS
THAN 5 HUNDREDTHS OF AN INCH. DUE TO THIS ICING...KEPT THE WINTER
WEATHER ADVISORY GOING.
FOR LATE TONIGHT...THE PRECIPITATION WILL BEGIN TO SHIFT EAST OF
THE AREA. AS THIS OCCURS...BOTH THE BUFKIT SOUNDINGS AND -10C
SURFACE SHOW THAT ICE WILL BE RETURNING TO THE AREA. AS A
RESULT...EXPECT THAT PRECIPITATION WILL CHANGE OVER LIGHT SNOW
BEFORE IT ENDS.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 402 AM CST FRI JAN 10 2014
ON SATURDAY...A DEFORMATION BAND WILL PRODUCE SOME LIGHT SNOW
MAINLY EAST OF THE MISSISSIPPI RIVER DURING THE MORNING. LITTLE...
IF ANY...ACCUMULATION IS EXPECTED.
ON SATURDAY NIGHT AND SUNDAY MORNING...A WARM FRONT WILL MOVE
THROUGH THE REGION. 850 MB TEMPERATURES QUICKLY WARM TO AROUND 7C.
SOUTHERLY WINDS IN THE WARM SECTOR OF THIS SYSTEM WILL ALLOW
TEMPERATURES TO WARM INTO THE MID AND UPPER 30S. WHILE THE GEM
GENERATES SOME PRECIPITATION AHEAD OF THIS FRONT...THE REMAINDER
OF THE MODELS KEEP THE AREA DRY. AS A RESULT...WENT WITH A DRY
FORECAST FOR THE AREA.
ON SUNDAY NIGHT...A COLD FRONT MOVES THROUGH THE REGION. MUCH OF
THE FORCING ASSOCIATED WITH THIS SYSTEM WILL REMAIN WELL NORTH OF
THE FORECAST AREA. HOWEVER THERE APPEARS TO BE ENOUGH
FRONTOGENESIS ALONG THIS FRONT TO PROVIDE ENOUGH LIFT TO WARRANT A
SLIGHT CHANCE OF RAIN AND SNOW.
ON MONDAY NIGHT AND TUESDAY...BOTH THE GFS AND ECMWF ARE SHOWING
THAT A STRENGTHENING SHORT WAVE TROUGH WILL MOVE THROUGH NORTHEAST
IOWA AND SOUTHERN WISCONSIN. WITH THIS BEING A NEW FEATURE IN THE
MODELS...OPTED TO JUST ADD A SMALL CHANCE OF SNOW WITH IT.
ON TUESDAY AND TUESDAY NIGHT...THE MODELS ARE NOW SHOWING STRONG
COLD AIR ADVECTION DEVELOPING IN THE WAKE OF THE SHORT WAVE
TROUGH. THIS DROPS THE 850 MB TEMPERATURES DOWN TO -10C. IF THIS
VERIFIES...HIGH TEMPERATURES WILL REMAIN IN THE TEENS. SINCE THIS
IS A NEW FEATURE...LOWERED THE TEMPERATURES BY 2 TO 3 DEGREES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1100 PM CST THU JAN 9 2014
IFR/MVFR CLOUDS HELD FAST ACROSS THE TAF SITES...AND WILL PERSIST
THROUGH FRI NIGHT. EXPECTING SOME ADDITIONAL LOWERING ON FRI AS THE
LOW SATURATION INCREASES AHEAD OF AN APPROACHING LOW. COULD BE SOME
FZDZ EARLY FRI AFTERNOON WHEN CLOUD DEPTH AND SUFFICIENT LIFT COME
TOGETHER. GRADUALLY...CLOUD DEPTH WILL DEEPEN ENOUGH FOR ICE IN THE
CLOUD...AND SNOW. THIS LOOKS TO BE NEAR 00Z AT KRST/KLSE. EXPECTING
SNOW ACCUMULATIONS OF 2 TO 4 INCHES...MOST OF WHICH WILL FALL FRI
NIGHT. THINK THE THREAT FOR FZRA/PL IS LIMITED AT THIS TIME...BETTER
CHANCES SOUTH/SOUTHEAST. WINDS WILL STAY SOUTHERLY THROUGH MUCH OF
FRIDAY...BECOMING WEST/NORTHWEST AS THE LOW TRACKS INTO SOUTHERN WI
FRI EVENING.
INTERESTING NOTE FOR THIS EVENING...VERY FINE -SN HAS FALLEN FOR A
FEW HOURS AT KRST. LATEST RAP SOUNDINGS INDICATE NEAR SFC TEMPS ARE
NEAR -10 C...WHICH WOULD BE ENOUGH TO PRODUCE ICE CRYSTALS...AND IS
THE LIKELY CAUSE FOR THE VERY LIGHT PCPN. IT WILL CONTRIBUTE TO VSBY
REDUCTIONS...AND COULD MAKE RUNWAYS SLICK. CURRENT EXPECTATION IS
THAT IT COULD LAST INTO THE OVERNIGHT HOURS...BUT SHOULD BE DONE
BEFORE 12Z.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...DENSE FOG ADVISORY UNTIL NOON CST TODAY FOR WIZ032>034-041>044-
053>055-061.
WINTER WEATHER ADVISORY FROM NOON TODAY TO 6 AM CST SATURDAY FOR
WIZ017-029-034-041>044-053>055-061.
MN...DENSE FOG ADVISORY UNTIL NOON CST TODAY FOR MNZ079-086>088-
094>096.
WINTER WEATHER ADVISORY FROM NOON TODAY TO 6 AM CST SATURDAY FOR
MNZ096.
IA...DENSE FOG ADVISORY UNTIL NOON CST TODAY FOR IAZ008>011-018-019-
029-030.
WINTER WEATHER ADVISORY FROM NOON TODAY TO 6 AM CST SATURDAY FOR
IAZ010-011-029-030.
&&
$$
UPDATE...BOYNE
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
403 AM CST FRI JAN 10 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 402 AM CST FRI JAN 10 2014
AT 4 AM...A SHORT WAVE TROUGH WAS LOCATED OVER THE DAKOTAS.
SOUTHERLY WINDS AND WARM AIR ADVECTION AHEAD OF THIS SYSTEM HAVE
CAUSED THE TEMPERATURES TO SLOWLY RISE OVERNIGHT. VISIBILITIES
HAVE DROPPED TO LESS THAN A MILE ACROSS MUCH OF NORTHEAST IOWA AND
SOUTHEAST MINNESOTA. WE HAVE STARTED TO HEAR OF A FEW ACCIDENTS
DUE TO THE SLICK ROADS. WHILE SOME OF THIS MOISTURE IS BEING
DEPOSITED BY THE FOG AND THE REMAINDER OF IT IS BEING CAUSED BY
THE DEW POINT TEMPERATURES CLIMBING ABOVE THE GROUND TEMPERATURE.
WITH TEMPERATURES BELOW FREEZING THIS MOISTURE IS FREEZING. STILL
DEBATING ON WHETHER TO ISSUE A FREEZING FOG ADVISORY OR A SPECIAL
WEATHER STATEMENT.
LIKE THE 09.18Z MODELS...WITH BOTH THE 270 AND 280K SHOWING VERY
LITTLE LIFT THIS MORNING AND THE BUFKIT SOUNDINGS SHOWING
SUBSIDENCE CO-LOCATED WITH THE LOW LEVEL MOISTURE...NOT EXPECTING
MUCH PRECIPITATION THIS MORNING. DUE TO THIS...DRAMATICALLY
LOWERED THE PRECIPITATION CHANCES FOR THIS MORNING. IF THERE IS
ANY PRECIPITATION IT WILL BE IN THE FORM OF DRIZZLE OR FREEZING
DRIZZLE. THIS PART OF THE FORECAST IS VERY TRICKY BECAUSE IT WILL
BE HIGHLY DEPENDENT UPON HOW MUCH ARE THE ROADS ABLE TO WARM.
DESPITE THE CLOUDS...THE SUN/S INFRARED RADIATION WILL CAUSE THE
ROADS TO WARM UP. OVER THE PAST COUPLE OF DAYS...THE ROADS HAVE
WARMED INTO THE MID AND UPPER 20S DURING THE AFTERNOON. THIS IS
DESPITE THE VERY COLD AIR TEMPERATURES. WITH TEMPERATURES MUCH
WARMER TODAY /LOWER TO MID 30S/...EXPECT THE UNSHELTERED ROADS TO
WARM VERY CLOSE TO THE AIR TEMPERATURE.
FOR THIS AFTERNOON AND EVENING...THE 10.00Z HAVE SHIFTED SOUTH
WITH ITS 500 MB VORTICITY MAXIMUM. AS A RESULT...THE TRACK OF THE
LOW PRESSURE SYSTEM AND ITS PRECIPITATION SHIFTED FURTHER TO THE
SOUTHEAST. DESPITE THE WARM LAYER ALOFT COOLING ALOFT...THERE HAS
ALSO BEEN A LOSS ICE ALOFT IN THE BUFKIT SOUNDINGS. THE -10C
SURFACE SHOWS THAT THE RELATIVE HUMIDITIES FROM CHARLES CITY IOWA
TO WAUSAU ARE AS LOW AS 70 PERCENT. AS A RESULT...EXPECT A BIT
MORE LIQUID THAN SNOW WITH THIS SYSTEM. THIS MORE PROBLEMATIC LATE
THIS AFTERNOON AND EVENING...BECAUSE WE WILL BE LOSING THE LONG
RADIATION FROM THE SUN AND THIS WILL CAUSE THE MANY OF THE ROADS
TO FALL QUICKLY BELOW FREEZING. DUE TO THE MIX PRECIPITATION AND A
FURTHER SOUTHEAST SHIFT IN THE PRECIPITATION...LOWERED THE SNOW
AMOUNTS INTO THE 1 TO 3 INCH RANGE. ICING WILL BE GENERALLY LESS
THAN 5 HUNDREDTHS OF AN INCH. DUE TO THIS ICING...KEPT THE WINTER
WEATHER ADVISORY GOING.
FOR LATE TONIGHT...THE PRECIPITATION WILL BEGIN TO SHIFT EAST OF
THE AREA. AS THIS OCCURS...BOTH THE BUFKIT SOUNDINGS AND -10C
SURFACE SHOW THAT ICE WILL BE RETURNING TO THE AREA. AS A
RESULT...EXPECT THAT PRECIPITATION WILL CHANGE OVER LIGHT SNOW
BEFORE IT ENDS.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 402 AM CST FRI JAN 10 2014
ON SATURDAY...A DEFORMATION BAND WILL PRODUCE SOME LIGHT SNOW
MAINLY EAST OF THE MISSISSIPPI RIVER DURING THE MORNING. LITTLE...
IF ANY...ACCUMULATION IS EXPECTED.
ON SATURDAY NIGHT AND SUNDAY MORNING...A WARM FRONT WILL MOVE
THROUGH THE REGION. 850 MB TEMPERATURES QUICKLY WARM TO AROUND 7C.
SOUTHERLY WINDS IN THE WARM SECTOR OF THIS SYSTEM WILL ALLOW
TEMPERATURES TO WARM INTO THE MID AND UPPER 30S. WHILE THE GEM
GENERATES SOME PRECIPITATION AHEAD OF THIS FRONT...THE REMAINDER
OF THE MODELS KEEP THE AREA DRY. AS A RESULT...WENT WITH A DRY
FORECAST FOR THE AREA.
ON SUNDAY NIGHT...A COLD FRONT MOVES THROUGH THE REGION. MUCH OF
THE FORCING ASSOCIATED WITH THIS SYSTEM WILL REMAIN WELL NORTH OF
THE FORECAST AREA. HOWEVER THERE APPEARS TO BE ENOUGH
FRONTOGENESIS ALONG THIS FRONT TO PROVIDE ENOUGH LIFT TO WARRANT A
SLIGHT CHANCE OF RAIN AND SNOW.
ON MONDAY NIGHT AND TUESDAY...BOTH THE GFS AND ECMWF ARE SHOWING
THAT A STRENGTHENING SHORT WAVE TROUGH WILL MOVE THROUGH NORTHEAST
IOWA AND SOUTHERN WISCONSIN. WITH THIS BEING A NEW FEATURE IN THE
MODELS...OPTED TO JUST ADD A SMALL CHANCE OF SNOW WITH IT.
ON TUESDAY AND TUESDAY NIGHT...THE MODELS ARE NOW SHOWING STRONG
COLD AIR ADVECTION DEVELOPING IN THE WAKE OF THE SHORT WAVE
TROUGH. THIS DROPS THE 850 MB TEMPERATURES DOWN TO -10C. IF THIS
VERIFIES...HIGH TEMPERATURES WILL REMAIN IN THE TEENS. SINCE THIS
IS A NEW FEATURE...LOWERED THE TEMPERATURES BY 2 TO 3 DEGREES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1100 PM CST THU JAN 9 2014
IFR/MVFR CLOUDS HELD FAST ACROSS THE TAF SITES...AND WILL PERSIST
THROUGH FRI NIGHT. EXPECTING SOME ADDITIONAL LOWERING ON FRI AS THE
LOW SATURATION INCREASES AHEAD OF AN APPROACHING LOW. COULD BE SOME
FZDZ EARLY FRI AFTERNOON WHEN CLOUD DEPTH AND SUFFICIENT LIFT COME
TOGETHER. GRADUALLY...CLOUD DEPTH WILL DEEPEN ENOUGH FOR ICE IN THE
CLOUD...AND SNOW. THIS LOOKS TO BE NEAR 00Z AT KRST/KLSE. EXPECTING
SNOW ACCUMULATIONS OF 2 TO 4 INCHES...MOST OF WHICH WILL FALL FRI
NIGHT. THINK THE THREAT FOR FZRA/PL IS LIMITED AT THIS TIME...BETTER
CHANCES SOUTH/SOUTHEAST. WINDS WILL STAY SOUTHERLY THROUGH MUCH OF
FRIDAY...BECOMING WEST/NORTHWEST AS THE LOW TRACKS INTO SOUTHERN WI
FRI EVENING.
INTERESTING NOTE FOR THIS EVENING...VERY FINE -SN HAS FALLEN FOR A
FEW HOURS AT KRST. LATEST RAP SOUNDINGS INDICATE NEAR SFC TEMPS ARE
NEAR -10 C...WHICH WOULD BE ENOUGH TO PRODUCE ICE CRYSTALS...AND IS
THE LIKELY CAUSE FOR THE VERY LIGHT PCPN. IT WILL CONTRIBUTE TO VSBY
REDUCTIONS...AND COULD MAKE RUNWAYS SLICK. CURRENT EXPECTATION IS
THAT IT COULD LAST INTO THE OVERNIGHT HOURS...BUT SHOULD BE DONE
BEFORE 12Z.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY FROM NOON TODAY TO 6 AM CST SATURDAY FOR
WIZ017-029-034-041>044-053>055-061.
MN...WINTER WEATHER ADVISORY FROM NOON TODAY TO 6 AM CST SATURDAY FOR
MNZ096.
IA...WINTER WEATHER ADVISORY FROM NOON TODAY TO 6 AM CST SATURDAY FOR
IAZ010-011-029-030.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1105 PM CST THU JAN 9 2014
.SHORT TERM...(TONIGHT THROUGH FRIDAY NIGHT)
ISSUED AT 324 PM CST THU JAN 9 2014
MAIN FORECAST CONCERNS CONTINUES FOCUSED ON THE STORM SYSTEM
IMPACTING THE REGION FRIDAY THROUGH FRIDAY NIGHT WITH THE POTENTIAL
FOR 2-5 INCHES OF SNOW AND A WINTRY MIX OF SNOW...FREEZING
DRIZZLE/RAIN...AND SLEET.
WATER VAPOR THIS AFTERNOON SHOWS SEVERAL EMBEDDED MID-LEVEL TROUGHS
AFFECTING OR THAT WILL BE AFFECTING THE AREA. TROUGHS OVER
MN/NORTHERN IL WERE SPREADING CLOUDS NORTHWARD INTO THE AREA.
SOUTHERLY WINDS AHEAD ON THE MN TROUGH AND ON THE BACKSIDE OF
SURFACE HIGH PRESSURE WAS HELPING TO BRING MODERATING TEMPERATURE
OVER THE REGION. TEMPERATURES AT 2 PM WERE IN THE SINGLE DIGITS AND
TEENS ABOVE ZERO. A MORE SIGNIFICANT MID-LEVEL WAVE WAS MOVING EAST
OUT OF THE INTERMOUNTAIN WEST...WHICH WILL PRODUCE A WINTRY
MIX/SNOWFALL ACROSS THE AREA FOR FRIDAY THROUGH FRIDAY NIGHT.
FOR TONIGHT...WILL BE WATCHING THE WAVE COMING OUT OF THE
INTERMOUNTAIN WEST INTO THE PLAINS. SOUTHERLY FLOW WILL AHEAD OF
THIS TROUGH/WAVE WILL CONTINUE TO ADVECT MOISTURE AND CLOUD COVER
INTO THE AREA. AS A RESULT...NOT LOOKING FOR MUCH TEMPERATURE DROP
OFF. LOWS SHOULD BOTTOM OUT 3-5 DEGREES COOLER THAN THE HIGHS FROM
TODAY...OR IN THE UPPER SINGLE DIGITS TO MIDDLE TEENS.
ON FRIDAY...AS THE TROUGH CLOSES IN ON THE REGION AND AIDING IN LIFT
...LOOKING FOR A SMALL CHANCE FOR SOME FREEZING DRIZZLE IN THE
MORNING. BUFKIT SOUNDINGS THEN SHOW THE COLUMN SATURATING UP TO
AROUND 5KFT DURING THE AFTERNOON HOURS...DEEP ENOUGH FOR A
DRIZZLE/RAIN MIX FOR PORTIONS OF THE AREA WITH LACK OF ICE IN THE
CLOUD FOR MAKING SNOW. ALTHOUGH FORECASTING TEMPERATURES TO WARM
INTO THE 32-35 DEGREE RANGE...FEEL THAT THE RECENT VERY COLD SNAP
WILL KEEP ROAD TEMPERATURES SOMEWHERE IN THE MID-UPPER 20S. THIS
WILL LIKELY LEAD TO SOME FREEZING RAIN...ESPECIALLY ALONG AND EAST
OF THE MISSISSIPPI RIVER. AREAS WEST OF THIS LOOK TO HAVE ENOUGH ICE
IN THE COLUMN FOR MORE SNOW. WILL LIKELY SEE ICE ACCUMULATIONS
RANGING FROM A TRACE TO 0.05 INCH THROUGH MAINLY THE
AFTERNOON//AGAIN MAINLY ALONG AND EAST OF THE MISSISSIPPI
RIVER//...WITH A FEW TENTHS OF SNOWFALL WEST OF A WINONA MN TO
CHARLES CITY LINE.
LOOK FOR THE WINTRY MIX TO CHANGE OVER TO SNOW FRIDAY NIGHT...EXCEPT
FOR AREAS OF NORTHEAST IA INTO FAR SOUTHWEST WI WHERE WARMER AIR
ALOFT LINGERS A BIT LONGER. ALSO OF NOTE IS ALMOST ALL OF THE MODELS
POINTING TOWARD A CLOSED/CLOSING MID-LEVEL LOW MOVING NORTHEAST
ACROSS THE AREA FRIDAY NIGHT AND THE POTENTIAL FOR A STRONGER BAND
OF 700-500MB FRONTOGENESIS/HEAVIER SNOWFALL FOR PORTIONS OF THE
AREA. THE HIGHEST LIKELIHOOD OF THIS HAPPENING LOOKS TO BE IN AN AXIS
FROM LA CROSSE AND BLACK RIVER FALLS ...INTO CENTRAL AND NORTHEAST
WI. 2-5 INCHES OF SNOWFALL LOOKS LIKELY ACROSS OUR AREA IN THE
AFOREMENTIONED AXIS.
BASED ON THE WINTRY MIX AND LIKELIHOOD FOR 2-5 INCHES OF
SNOWFALL...HAVE HOISTED A WINTER WEATHER ADVISORY FOR A PART OF
NORTHEAST EAST IA AND PORTIONS OF SOUTHWEST INTO CENTRAL WI...IN
EFFECT FROM NOON FRIDAY THROUGH FRIDAY NIGHT OR 12Z SATURDAY.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 324 PM CST THU JAN 9 2014
EXPECTING THE MID-LEVEL/SURFACE LOW TO PULL NORTHEAST OF THE AREA
SATURDAY MORNING WITH PERHAPS SOME LINGERING LIGHT SNOW ALONG AND
EAST OF THE MISSISSIPPI RIVER. LOOK FOR HIGHS ON SATURDAY IN THE
UPPER 20S TO LOWER 30S...BUT INCREASING NORTHWEST WINDS ON THE
BACKSIDE OF THE DEPARTING LOW WILL MAKE IT FEEL MORE LIKE THE TEENS
TO LOWER 20S.
A RIDGE OF HIGH PRESSURE WILL GIVE THE AREA A BRIEF QUIET PERIOD
SATURDAY NIGHT WITH LOWS BOTTOMING OUT IN THE 10 TO 15 DEGREE RANGE.
CLOUDS AND A CHANCE OF A WINTRY MIX WILL ENTER THE PICTURE AGAIN
SUNDAY INTO SUNDAY NIGHT AS A COLD FRONT DROPS INTO THE REGION.
EXPECTING HIGHS ON SUNDAY IN THE 30S IN ADVANCE OF THE COLD
FRONT...AND THEN DROPPING INTO THE TEENS/LOWER 20S SUNDAY NIGHT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1100 PM CST THU JAN 9 2014
IFR/MVFR CLOUDS HELD FAST ACROSS THE TAF SITES...AND WILL PERSIST
THROUGH FRI NIGHT. EXPECTING SOME ADDITIONAL LOWERING ON FRI AS THE
LOW SATURATION INCREASES AHEAD OF AN APPROACHING LOW. COULD BE SOME
FZDZ EARLY FRI AFTERNOON WHEN CLOUD DEPTH AND SUFFICIENT LIFT COME
TOGETHER. GRADUALLY...CLOUD DEPTH WILL DEEPEN ENOUGH FOR ICE IN THE
CLOUD...AND SNOW. THIS LOOKS TO BE NEAR 00Z AT KRST/KLSE. EXPECTING
SNOW ACCUMULATIONS OF 2 TO 4 INCHES...MOST OF WHICH WILL FALL FRI
NIGHT. THINK THE THREAT FOR FZRA/PL IS LIMITED AT THIS TIME...BETTER
CHANCES SOUTH/SOUTHEAST. WINDS WILL STAY SOUTHERLY THROUGH MUCH OF
FRIDAY...BECOMING WEST/NORTHWEST AS THE LOW TRACKS INTO SOUTHERN WI
FRI EVENING.
INTERESTING NOTE FOR THIS EVENING...VERY FINE -SN HAS FALLEN FOR A
FEW HOURS AT KRST. LATEST RAP SOUNDINGS INDICATE NEAR SFC TEMPS ARE
NEAR -10 C...WHICH WOULD BE ENOUGH TO PRODUCE ICE CRYSTALS...AND IS
THE LIKELY CAUSE FOR THE VERY LIGHT PCPN. IT WILL CONTRIBUTE TO VSBY
REDUCTIONS...AND COULD MAKE RUNWAYS SLICK. CURRENT EXPECTATION IS
THAT IT COULD LAST INTO THE OVERNIGHT HOURS...BUT SHOULD BE DONE
BEFORE 12Z.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY FROM NOON FRIDAY TO 6 AM CST SATURDAY
FOR WIZ017-029-034-041>044-053>055-061.
MN...WINTER WEATHER ADVISORY FROM NOON FRIDAY TO 6 AM CST SATURDAY
FOR MNZ096.
IA...WINTER WEATHER ADVISORY FROM NOON FRIDAY TO 6 AM CST SATURDAY
FOR IAZ010-011-029-030.
&&
$$
SHORT TERM...DAS
LONG TERM....DAS
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS TAUNTON MA
344 AM EST SUN JAN 12 2014
.SYNOPSIS...
WEAK AREA OF HIGH PRESSURE WILL MOVE SOUTH OF THE REGION TODAY
INTO TOMORROW. THIS WILL BRING A PERIOD OF GUSTY WINDS TODAY...BUT
MILD TEMPERATURES BOTH TODAY AND TOMORROW. A PERIOD OF UNSETTLED
WEATHER IS EXPECTED TUE AND AGAIN LATE WED OR WED NIGHT AS A
SERIES OF LOW PRESSURE SYSTEMS MOVES INTO THE REGION. HIGH PRES
RETURNS THU THEN A STRONG COLD FRONT WILL BRING BELOW NORMAL
TEMPERATURES THIS WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SFC COLD FRONT CURRENTLY DRAPED FROM JUST S OF BOS SW TO CENTRAL
CT AND CONTINUING TO MOVE E. THIS SHOULD BE OFFSHORE BY AROUND
11-12Z. PWATS AHEAD OF THIS FRONT STILL HOVERING AROUND 1.0 INCHES
SO THE FRONT IS PROVIDING JUST ENOUGH LIFT TO KEEP SOME LIGHT TO
MOD -SHRA GOING. THESE TOO WILL BE GRADUALLY ENDING BY ABOUT 12Z
SO HAVE TIMED POPS ACCORDINGLY...BASED MAINLY ON A BLEND OF HRRR
AND RAP WHICH ARE HANDLING THE CURRENT -SHRA BANDS WELL.
OTHERWISE...AM ALREADY NOTING SOME CLEARING ACROSS WRN INTERIOR
ZONES BUT THE MIXING PROVIDED BY THE FRONT AND THE MID LVL COLD
ADVECTION HAVE KEPT TEMPS FROM DROPPING OFF TOO FAST. ONLY SOME
UPPER 30S APPARENT IN NW MASS AND SW NH. THEREFORE...SUSPECT MANY
LOCATIONS WILL STILL BE IN THE MID 30S TO MID 40S BY DAYBREAK WITH
ENOUGH CLEARING BY THEN THAT MUCH OF THE REGION SHOULD SEE
SUNSHINE EARLY. THEREFORE...MIXING SHOULD BE ESTABLISHED EARLY AND
WITH TEMPS ABOVE NORMAL...SUSPECT MIXING TO COME CLOSE TO TAPPING
H85. TEMPS MAY CONTINUE TO DROP THROUGH ABOUT MID MORNING BUT
MIXING SHOULD ALLOW THEM TO START TO RISE AGAIN INTO THE
AFTERNOON...WITH MAX VALUES RANGING FROM THE LOW 40S TO CLOSE TO
50 IN THE COASTAL PLAIN OF MA.
THE MAIN ISSUE WITH THESE ANOMALOUSLY WARM TEMPS AND DECENT MIXING
IS THAT GUIDANCE CONTINUES TO BE FAIRLY CONSISTENT WITH A 40-45
KT WSW WIND SPEED MAX AT THIS LEVEL...WHICH PEAKS MID AFTERNOON.
THEREFORE...FEEL THIS MOMENTUM WILL BE TAPPED. THE MAIN CORE OF
THE MAX FALLS MAINLY ACROSS WRN MA AND SRN NH. THEREFORE...WILL BE
ISSUING A WIND ADVISORY FOR WINDS AROUND 45 MPH THROUGH THE
DAYLIGHT HOURS. FOR NOW THE FOCUS WILL BE ON WRN MA AND SRN
NH WHERE CONFIDENCE IS HIGHER AND DOWNSLOPING MAY ASSIST WITH
MIXING THE BL...BUT MAY NEED TO MONITOR FOR POSSIBLE EXPANSION S
AND E SHOULD THE CORE OF THIS SPEED MAX SHIFT SOMEWHAT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
TONIGHT...
WINDS RAPIDLY DIE OFF OVER LAND TONIGHT THANKS TO A COMBINATION OF
LACK OF MIXING AFTER SUNSET AND GRADUAL CREST OF HIGH PRES TO THE
S. THIS RIDGE WILL ALLOW SKIES TO BE MAINLY CLEAR THROUGH THE
OVERNIGHT HOURS AND THE WEAK FLOW WILL LEAD TO DECENT SETUP FOR
RADIATIONAL COOLING ACROSS THE REGION AWAY FROM THE COAST.
THEREFORE...EXPECT MINS TO FALL BACK INTO THE 20S AND LOW 30S.
MONDAY...
SFC HIGH PRES WILL MOVE OFFSHORE AS MID LVL RIDGING CRESTS OVER
THE REGION DURING THE DAYLIGHT HOURS THEREFORE...EXPECTING A
MAINLY DRY DAY AS THE HIGH SHOULD PREVENT PRECIP IN ADVANCE OF A
SECONDARY COLD FRONT TO THE W FROM AFFECTING THE REGION UNTIL THE
OVERNIGHT HOURS. LITTLE CHANGE IN THE AIRMASS IN PLACE AND ANOTHER
ROUND OF DECENT MIXING SUGGESTS MAX TEMPS WILL BE CLOSE TO IF NOT
SLIGHTLY WARMER THAN SUNDAY ALBEIT WITH WEAKER SW FLOW.
THEREFORE...HAVE HIGHS IN THE LOW 40S TO AROUND 50 DESPITE A SLOW
INCREASE IN AFTERNOON AND EVENING CLOUD COVER IN ADVANCE OF THE
INCOMING WAVE.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
HIGHLIGHTS...
* ABOVE NORMAL TEMPERATURES THROUGH FRIDAY
* RAIN LIKELY TUE...ESPECIALLY NEAR THE COAST THEN RAIN/SNOW SHOWERS
POSSIBLE WED/WED NIGHT
* COLDER NEXT WEEKEND WITH BELOW NORMAL TEMPS
OVERVIEW...
MEDIUM RANGE GUIDANCE IN REASONABLY GOOD AGREEMENT ON AMPLIFYING
PATTERN NEXT WEEK WITH MAIN FEATURES BEING A BUILDING RIDGE ACROSS
THE WESTERN CONUS AND A MEAN TROF OVER THE LAKES. A SERIES OF
FRONTAL WAVES WILL DEVELOP AND MOVE THROUGH THE NE...BUT THERE ARE
DIFFERENCES IN THE TRACK AND STRENGTH OF THESE WAVES WHICH AFFECT
SENSIBLE WEATHER. GENERALLY ABOVE NORMAL TEMPS EXPECTED THROUGH THE
END OF THE WEEK. THERE WILL BE TWO MAIN THREATS OF PRECIP...LATE
MON NIGHT AND TUE AND AGAIN LATE WED/WED NIGHT BUT THERE ARE
DIFFERENCES IN THE GUIDANCE. INTERNATIONAL MODEL SUITE IS CLOSER TO
THE COAST WITH THE FRONTAL WAVE AND WETTER THAN US MODELS FOR TUE
AND WE LEANED TOWARD WETTER SOLUTION. MEANWHILE GFS IS MORE ROBUST
THAN ECMWF AND ITS ENSEMBLES WITH A WAVE MOVING INTO NEW ENG WED
NIGHT WITH A LIGHT INTERIOR SNOWFALL AS A MORE AMPLIFIED TROF
APPROACHES...BUT ECMWF SHOWING JUST A FROPA. THESE FRONTAL WAVES AT
LONGER TIME RANGES OFFER LOW PREDICTABILITY SO CONFIDENCE IS BELOW
AVERAGE. THE MAIN LONGWAVE TROF AXIS EVENTUALLY MOVES EAST INTO NEW
ENG FOR THE WEEKEND WHICH WILL BRING COLDER TEMPS.
DAILIES...
MON NIGHT INTO TUE...
APPROACHING COLD FRONT WILL BRING INCREASING CHC SHOWERS TO INTERIOR
MON NIGHT...THEN WE TRENDED FORECAST TOWARD WETTER ECMWF SOLUTION
WITH DEVELOPING FRONTAL WAVE ON THE BAROCLINIC ZONE BRINGING A
PERIOD OF RAIN...ESPECIALLY TUE AFTERNOON INTO THE EARLY EVENING IN
THE COASTAL PLAIN. POPS WERE INCREASED TO LIKELY NEAR THE COAST.
UKMET RATHER BULLISH ON RAINFALL WITH UP TO AN INCH NEAR THE COAST
AND ECMWF WHILE LIGHTER ALSO HAS DECENT SLUG OF QPF.
HOWEVER...FORECAST CONFIDENCE IS BELOW AVERAGE AND NOTE THAT GFS/NAM
ARE MAINLY DRY TUE AFTERNOON. ANOTHER MILD DAY WITH TEMPS WELL
ABOVE NORMAL.
WED INTO WED NIGHT...
NEXT MORE AMPLIFIED TROF APPROACHES FROM THE WEST WITH A COLD FRONT
MOVING INTO THE REGION LATE WED/WED NIGHT. THIS SHOULD BRING
RAIN/SNOW SHOWERS...BUT LOW CONFIDENCE ON POTENTIAL FOR A COASTAL
WAVE BRINGING A MORE ORGANIZED SNOWFALL TO THE INTERIOR PER GFS.
THURSDAY...
LOOKS MAINLY DRY AS RIDGING DEVELOPS BEHIND DEPARTING WAVE...WITH
OCEAN LOW DEVELOPMENT ASSOCD WITH SOUTHERN PART OF THE TROF REMAINING
FAR ENOUGH OFFSHORE. COOLER TEMPS IN POST FRONTAL AIRMASS...BUT
JUST CLOSER TO SEASONABLE NORMALS.
FRIDAY AND SATURDAY... SOMEWHAT MILDER TEMPS MOVE BACK IN FRI AHEAD
OF THE MAIN TROF AND COLD FRONT...THEN COLDER TEMPS TRENDING BELOW
NORMAL FOR NEXT WEEKEND. CHC SNOW SHOWERS FRI NIGHT AND SAT AS TROF
AXIS MOVES INTO NEW ENG...AND WILL HAVE TO WATCH FOR A POSSIBLE WAVE
DEVELOPING JUST OFFSHORE ON THE FRONT FOR SAT.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH MONDAY/...
HIGH CONFIDENCE IN TRENDS...LOWER CONFIDENCE IN TIMING THIS
MORNING.
THROUGH 12Z...
GRADUALLY IMPROVEMENT TO VFR EVERYWHERE AS THE
COLD FRONT MOVES THROUGH THE ERN TERMINALS IN THE NEXT COUPLE OF
HOURS. WINDS WILL BE SHIFTING FROM MOSTLY SSW TO WSW AS THE FRONT
MOVES THROUGH. ONCE THE WINDS SHIFT VFR IS EXPECTED EVERYWHERE.
OTHERWISE...
VFR DOMINATES THROUGH MONDAY. MAIN CONCERN WILL BE THE THREAT FOR
WSW WIND GUSTS AROUND 40 KT DURING THE DAYLIGHT HOURS TODAY. THIS
WILL BE A THREAT OVER NEARLY ALL TERMINALS...BUT TERMINALS AT
HIGHER ELEVATIONS WILL HAVE A SLIGHTLY BETTER CHANCE. THE WINDS
SHOULD DROP OFF OVERNIGHT AND INCREASE AGAIN A BIT MONDAY...BUT
NOT AS STRONG.
KBOS TAF...HIGH CONFIDENCE IN TRENDS. LOWER CONFIDENCE IN EXACT
TIMING OF STRONGER WIND GUSTS AFTER SUNRISE.
KBDL TAF...HIGH CONFIDENCE IN TRENDS. LOWER CONFIDENCE IN EXACT
TIMING OF STRONGER WIND GUSTS AFTER SUNRISE.
OUTLOOK...MONDAY NIGHT THROUGH THURSDAY...
MON NIGHT INTO TUE...MODERATE CONFIDENCE. LOWERING TO MVFR/IFR AS
SHOWERS MOVE INTO THE REGION FROM THE WEST MON NIGHT...WITH MAIN
FOCUS FOR RAIN ON TUESDAY IN THE COASTAL PLAIN.
WED...LOW CONFIDENCE. CONDITIONS MAY LOWER TO MVFR/IFR IN ANOTHER
PERIOD OF RA/SNOW SHOWERS WED INTO WED NIGHT.
THU...MODERATE CONFIDENCE. VFR.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
NEAR TERM /THROUGH MONDAY/...HIGH CONFIDENCE.
TODAY INTO EARLY MONDAY...
W GALE FORCE WINDS /TO AROUND 40 KT IN SPOTS/ ARE EXPECTED THROUGH
THE DAY TODAY WHICH WILL GIVE WAY TO 25-30 KT WINDS THIS EVENING
AND FINALLY SUB 25 KT WINDS BY EARLY MONDAY MORNING. THEREFORE
GALE WARNINGS PREVAIL THROUGH THE DAY TODAY WHICH WILL GIVE WAY
TO SMALL CRAFT ADVISORIES OVERNIGHT. THE SMALL CRAFTS ARE LIKELY
TO STAY UP INTO THE MID DAY HOURS MONDAY AS SEAS WILL TAKE SOME
TIME TO DROP BELOW 5 FT ON THE OCEAN WATERS ESPECIALLY.
LATE MONDAY...
ALTHOUGH WINDS WILL SHIFT TO THE SW AND DROP OFF FOR MUCH OF THE
DAY...SEAS MAY HOLD AT OR ABOVE 5 FT ON OCEAN WATERS. SOME SMALL
CRAFTS MAY CONTINUE.
OUTLOOK...MONDAY NIGHT THROUGH THURSDAY...
MON NIGHT INTO TUE...A PERIOD OF SCA SW WINDS LIKELY MON NIGHT
ASSOCD WITH A LOW LEVEL JET...THEN DIMINISHING WIND TUE. BUT LOW
CONFIDENCE ON POTENTIAL FOR STRONGER WINDS DEVELOPING OVER EASTERN
WATERS WITH LOW PRES. VSBYS OCCASIONALLY REDUCED IN RAIN AND
FOG...ESPECIALLY ON TUE.
WED...MODERATE CONFIDENCE. SW WINDS MAINLY BELOW SCA...SHIFTING TO
W/NW WED NIGHT.
THU...MODERATE CONFIDENCE. WINDS BELOW SCA THU...BUT INCREASING SW
FLOW THU NIGHT AHEAD OF A COLD FRONT.
&&
.HYDROLOGY...
* FLOOD WATCHES REMAIN IN PLACE FOR NORTHERN CT...WESTERN MA AND
SRN NH.
BULK OF THE RAIN HAS ENDED SAVE FOR A FEW SHOWERS OVER ERN MA/RI
WHICH WILL BE OFFSHORE BY AROUND 7 AM. OVERALL RAINFALL TOTALS
WERE GENERALLY CLOSE TO IF NOT SLIGHTLY BELOW THE PROJECTED
AMOUNTS WITH IN THE WATCH AND A BIT HIGHER IN ERN MA AND RI.
HOWEVER...ICE IS NOT AS MUCH OF AN ISSUE WHERE THE HEAVIER RAIN
FELL.
DESPITE THE FACT THAT RAIN TOTALS WERE NOT AS HIGH IS THEY MIGHT
HAVE BEEN...WE CONTINUE TO NOTE RAPID RISES OF SEVERAL STREAMS IN
WRN MA/NH PARTICULARLY THOSE WHICH WERE KNOWN TO BE ICE COVERED.
THEREFORE...SINCE TEMPERATURES ARE GENERALLY EXPECTED TO REMAIN
ABOVE FREEZING THROUGH THE DAY TODAY...MORE ICE MOVEMENT IS
POSSIBLE WHICH COULD TRIGGER DAMMING AND RAPID RISES UNTIL THE NEW
RAINFALL IS FLUSHED OUT. THEREFORE...WILL MAINTAIN THE CURRENT
WATCH AND ITS TIMING THROUGH THIS EVENING DUE TO THE CONTINUED
THREAT. IF...BY LATE THIS EVENING NOT MUCH MOVEMENT OR DAMMING IS
OBSERVED...THE LACK OF RAINFALL FOR ABOUT 12 HOURS...AND THE FACT
THAT TEMPERATURES WILL DROP BACK TO FREEZING AGAIN TONIGHT SHOULD
MITIGATE FURTHER RISK.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...FLOOD WATCH THROUGH THIS AFTERNOON FOR CTZ002>004.
MA...FLOOD WATCH THROUGH THIS AFTERNOON FOR MAZ002>004-008>012-026.
WIND ADVISORY FROM 7 AM THIS MORNING TO 7 PM EST THIS EVENING
FOR MAZ002>004-008>012-026.
NH...FLOOD WATCH THROUGH THIS AFTERNOON FOR NHZ011-012-015.
WIND ADVISORY FROM 7 AM THIS MORNING TO 7 PM EST THIS EVENING
FOR NHZ011-012-015.
RI...NONE.
MARINE...GALE WARNING FROM 10 AM THIS MORNING TO 7 PM EST THIS EVENING
FOR ANZ231>234.
GALE WARNING FROM 7 AM THIS MORNING TO 7 PM EST THIS EVENING
FOR ANZ230-235>237.
GALE WARNING FROM 7 AM THIS MORNING TO 10 PM EST THIS EVENING
FOR ANZ250-251-254>256.
&&
$$
SYNOPSIS...KJC/DOODY
NEAR TERM...DOODY
SHORT TERM...DOODY
LONG TERM...KJC
AVIATION...KJC/DOODY
MARINE...KJC/DOODY
HYDROLOGY...STAFF
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
131 AM EST SUN JAN 12 2014
.SYNOPSIS...
AN INTENSIFYING LOW PRESSURE SYSTEM OVER SOUTHERN CANADA WILL
CAUSE ITS ASSOCIATED COLD FRONT TO CROSS THE REGION OVERNIGHT.
HIGH PRESSURE WILL THEN BUILD OVER THE AREA SUNDAY AND MONDAY,
FOLLOWED BY ANOTHER COLD FRONT ON TUESDAY. A SECONDARY COLD FRONT
IS EXPECTED TO MOVE THROUGH THE AREA WEDNESDAY WITH A LOW PRESSURE
SYSTEM POSSIBLY DEVELOPING ALONG IT NEAR OUR FORECAST AREA. A HIGH
PRESSURE SYSTEM FROM THE SOUTHERN ROCKIES WILL THEN NOSE INTO THE
REGION ON THURSDAY. AN ARCTIC COLD FRONT IS FORECAST TO MOVE
THROUGH THE AREA LATER FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
THE COLD FRONT IS IN THE DELAWARE VALLEY AND WILL BE MOVING
OFFSHORE IN THE NEXT ONE TO TWO HOURS. THE STRONG SHORT WAVE ON
THE LEADING SIDE OF THE TROF IN PA IS MAKING ONE LAST DITCHED
EFFORT TO GENERATE SOME SHOWERS AS IT MOVES THROUGH. WE ADJUSTED
POPS SLIGHTLY FOR THIS FEATURE. HRRR LOOKS WELL TIMED WITH IT.
OTHERWISE VERY FEW OTHER ADJUSTMENTS WERE MADE WITH THIS UPDATE.
ONCE THE FRONT CROSSES THE AREA...WINDS WILL SHIFT TO WEST AND
BECOME SOMEWHAT GUSTY. SKIES WILL REMAIN CLOUDY OVERNIGHT WITH
SOME BREAKS DEVELOPING TOWARDS DAWN. TEMPERATURES WILL FALL
STEADILY AFTER FROPA...REACHING THE MID/UPPER 30S IN MOST AREAS
OVERNIGHT (A FEW LOW 30S UP NORTH).
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM MONDAY/...
A BRISK BUT DRY DAY FOR SUNDAY. WITH THE NORTHWEST FLOW OFF ONTARIO
AND AT LEAST A HIGH ENOUGH INVERSION, WE KEPT THE MENTION OF SOME
SNOW FLURRIES FOR THE POCONOS. ELSEWHERE, MOSTLY SUNNY SKIES SHOULD
OCCUR. A MET/MAV GUIDANCE BLEND WAS USED AND RESULTED IN VERY LITTLE
CHANGE FROM PREVIOUS FORECAST.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
WITH THE ON-GOING AND MONITORING THE RIVER LEVELS DID NOT CHANGE
MUCH BEYOND TUESDAY THOUGH DID BLEND IN SOME NEW 12Z WPC GUIDANCE
WITH OUR PREVIOUS FORECAST.
WE START OFF WITH BUILDING HEIGHTS AND MID-LEVEL RIDGING CONTINUING
TO WORKS ITS WAY IN FROM THE WEST. THIS SHOULD PROVIDE CLEAR SKIES
MONDAY MORNING PROVIDING GOOD RADIATIONAL COOLING CONDITIONS. WITH
THE HEIGHTS RISING SO DO THE TEMPERATURES...AGAIN. DAYTIME HIGHS
SHOULD BE A FEW DEGREES WARMER THAN ON SUNDAY...STILL NEARLY 10
DEGREES ABOVE NORMAL SO OUR THAWING WILL CONTINUE AND WE WILL REMAIN
DRY.
AS FOR NOW, WITH THE NEXT SYSTEM EXPECTED TO ENTER FROM THE WEST
LATE MONDAY NIGHT INTO TUESDAY, THE MID-LEVEL FLOW STILL KEEPS US
UNDER ITS SOUTHWEST INFLUENCE ALLOWING FOR BETTER MOISTURE ADVECTION
AND WARMER TEMPERATURES. AS THE FRONT NEARS RAIN WILL OVERSPREAD
FROM THE SOUTHWEST WITH STRONGER THETA-E ADVECTION AND THEN THE COLD
FRONT SWEEPS THROUGH. THE MID-LEVEL WAVELENGTH APPEARS RATHER LONG
AND THUS A QUICK EXIT IS EXPECTED WITH THIS SYSTEM.
THERE SHOULD BE A PCPN BREAK ON TUESDAY NIGHT BEFORE THE NEXT COLD
FRONT ARRIVES ON WEDNESDAY. HERE A MAJORITY OF THE GUIDANCE SHOWS
MORE OF A POSITIVE TILT TO THE TROUGHING AS IT NEARS FROM THE
WEST-NORTHWEST, THOUGH THE STRENGTH OF THE SYSTEM IS VARIABLE FROM
THE GFS TO THE EC TO THE NHGEM. AGAIN THE MID-LEVEL WAVELENGTH
APPEARS TO BE TOO LONG AND THE QUESTION THEN BECOMES CAN ENOUGH
ENERGY BE PUMPED INTO THE BACKSIDE OF THE TROUGH TO HELP IT SHARPEN
AND CUT ITS WAVELENGTH IN HALF...DOWNSTREAM BLOCKING DOES NOT SEEM
TO HELP THIS A QUICKER SHARPENING. THIS IS FAR FROM BEING ETCHED IN
STONE AND THIS ONE WOULD BE COLD ENOUGH TO HAVE SOME SNOW OCCUR.
AFTER THIS LOW DEPARTS, HIGH PRESSURE WILL BUILD INTO THE REGION.
WHILE TEMPERATURES SHOULD RETURN CLOSER TO NORMAL, THIS HIGH`S
ORIGIN IS FROM THE PACIFIC. SO UNLIKE LAST WEEK`S VERSION, THIS AIR
MASS HAS MORE OF ITS COLDNESS (RELATIVE TO NORMAL) IN THE UPPER HALF
OF THE TROPOSPHERE. THE NEXT COLD FRONT IS SCHEDULED FOR FRIDAY.
THIS ONE MAY BE MOISTURE STARVED. BUT THE ENSUING HIGH BEHIND THIS
FRONT IS COMING FROM WESTERN CANADA AND WILL BRING EVEN COLDER AIR
BACK INTO THE REGION. PLEASE DONT CURB YOUR ENTHUSIASM.
&&
.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THE 06Z TAFS ARE PRIMARILY VFR. WE KEPT SOME MVFR CIGS EARLY AT
KMIV AND KACY UNTIL THE FRONT CLEARS THEM AROUND 07Z. ELSEWHERE A
VFR CIG STARTS THE TAFS ALONG WITH SOME GUSTINESS IN THE NEWFOUND
WESTERLY FLOW. FOG SHOULD NOT BE AN ISSUE ONCE THE FRONT CLEARS,
SO EVEN EASTERNMOST AIRPORTS ARE ABOUT TO LOSE ANY FOG PROBLEMS.
TOWARD MORNING WE DROP THE WIND GUSTS AND ALSO LOSE THE VFR CIG
MAKING IT EITHER CLEAR TOWARD THE COAST OR SCATTERED AT INLAND
AIRPORTS.
THIS MORNING, NORTHWEST WINDS SHOULD INCREASE AND AVERAGE CLOSE TO
15 KTS WITH GUSTS BETWEEN 20 AND 30 KTS. THIS WILL CONTINUE INTO
THE AFTERNOON. CLOUDS: WE DO BRING A TEMPORARY VFR CIG INTO KABE
AND KRDG. ELSEWHERE WE KEPT THE CU/SC DECK AT FEW/SCATTERED
COVERAGE. TOWARD THE COAST WE JUST MENTION SOME CIRRUS.
SUNDAY EVENING AND INTO THE EARLY OVERNIGHT. WINDS WILL DECREASE
RAPIDLY AND ANY CU OR SC CLOUDS WILL DISSIPATE. BY THE MIDDLE/LATE
EVENING MOST TERMINALS WILL HAVE LIGHT AND VARIABLE WINDS.
EXCEPTION IS KPHL WHERE WE BACKED THE (STILL LIGHTER) WINDS TO
THE SOUTHWEST.
OUTLOOK...
MONDAY...VFR. GUSTY SOUTHWEST WINDS DEVELOPING.
MONDAY NIGHT AND TUESDAY...VFR GIVING WAY TO POSSIBLE MVFR IN RAIN.
POSSIBLE RAIN/SNOW MIX WELL NORTH AND WEST OF ABE.
TUESDAY NIGHT...A VFR PERIOD. CONFIDENCE OF TIMING BETWEEN SYSTEMS
IS LOW.
WEDNESDAY...MVFR TO IFR CONDITIONS POSSIBLE. GUSTY NORTHWEST WINDS
LATER WEDNESDAY. CHANGEOVER FROM RAIN TO SNOW POSSIBLE...CONFIDENCE
IS LOW AT THIS POINT.
&&
.MARINE...
VERY LITTLE CHANGE ON THE AFTERNOON UPDATE. GALE WARNINGS CONTINUE
UNTIL 100 AM AND WILL BE FOLLOWED BY SMALL CRAFT ADVISORIES.
WIDESPREAD FOG WITH VISIBILITIES DOWN TO A HALF MILE (AND EVEN LOWER
IN SOME LOCATIONS) WILL CONTINUE UNTIL THE COLD FRONT PASSES THIS
EVENING.
SUNDAY...SMALL CRAFT CONDITIONS ARE EXPECTED...DIMINISHING LATE IN
THE DAY AS THE CAA WEAKENS AS DOES THE WESTERLY FLOW.
OUTLOOK...
MONDAY AND MONDAY NIGHT...POSSIBLE LOW END SMALL CRAFT ADVISORY
CRITERIA IN SOUTHERLY FLOW PRECEDING A COLD FRONT.
TUESDAY...NEAR SMALL CRAFT ADVISORY CRITERIA ON THE OCEAN AS ANOTHER
COLD FRONT MOVES THROUGH. SUB SMALL CRAFT ADVISORY CRITERIA ON
DELAWARE BAY.
TUESDAY NIGHT AND WEDNESDAY...A POSSIBLE SMALL CRAFT ADVISORY LULL
PERIOD WITH AN INCREASING LIKELIHOOD OF SMALL CRAFT ADVISORY CRITERIA
RETURNING BEHIND THE PASSAGE OF THE NEXT COLD FRONT.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR
ANZ450>455.
SMALL CRAFT ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR ANZ430-
431.
&&
$$
SYNOPSIS...GIGI/MIKETTA
NEAR TERM...GIGI/SZATKOWSKI/O`HARA
SHORT TERM...SZATKOWSKI
LONG TERM...GIGI/HEAVENER
AVIATION...GIGI/HEAVENER
MARINE...GIGI/SZATKOWSKI/HEAVENER
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1223 AM EST SUN JAN 12 2014
.SYNOPSIS...
AN INTENSIFYING LOW PRESSURE SYSTEM OVER SOUTHERN CANADA WILL
CAUSE ITS ASSOCIATED COLD FRONT TO CROSS THE REGION OVERNIGHT.
HIGH PRESSURE WILL THEN BUILD OVER THE AREA SUNDAY AND MONDAY,
FOLLOWED BY ANOTHER COLD FRONT ON TUESDAY. A SECONDARY COLD FRONT
IS EXPECTED TO MOVE THROUGH THE AREA WEDNESDAY WITH A LOW PRESSURE
SYSTEM POSSIBLY DEVELOPING ALONG IT NEAR OUR FORECAST AREA. A HIGH
PRESSURE SYSTEM FROM THE SOUTHERN ROCKIES WILL THEN NOSE INTO THE
REGION ON THURSDAY. AN ARCTIC COLD FRONT IS FORECAST TO MOVE
THROUGH THE AREA LATER FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
THE COLD FRONT IS IN THE DELAWARE VALLEY AND WILL BE MOVING
OFFSHORE IN THE NEXT ONE TO TWO HOURS. THE STRONG SHORT WAVE ON
THE LEADING SIDE OF THE TROF IN PA IS MAKING ONE LAST DITCHED
EFFORT TO GENERATE SOME SHOWERS AS IT MOVES THROUGH. WE ADJUSTED
POPS SLIGHTLY FOR THIS FEATURE. HRRR LOOKS WELL TIMED WITH IT.
OTHERWISE VERY FEW OTHER ADJUSTMENTS WERE MADE WITH THIS UPDATE.
ONCE THE FRONT CROSSES THE AREA...WINDS WILL SHIFT TO WEST AND
BECOME SOMEWHAT GUSTY. SKIES WILL REMAIN CLOUDY OVERNIGHT WITH
SOME BREAKS DEVELOPING TOWARDS DAWN. TEMPERATURES WILL FALL
STEADILY AFTER FROPA...REACHING THE MID/UPPER 30S IN MOST AREAS
OVERNIGHT (A FEW LOW 30S UP NORTH).
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM MONDAY/...
A BRISK BUT DRY DAY FOR SUNDAY. WITH THE NORTHWEST FLOW OFF ONTARIO
AND AT LEAST A HIGH ENOUGH INVERSION, WE KEPT THE MENTION OF SOME
SNOW FLURRIES FOR THE POCONOS. ELSEWHERE, MOSTLY SUNNY SKIES SHOULD
OCCUR. A MET/MAV GUIDANCE BLEND WAS USED AND RESULTED IN VERY LITTLE
CHANGE FROM PREVIOUS FORECAST.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
WITH THE ON-GOING AND MONITORING THE RIVER LEVELS DID NOT CHANGE
MUCH BEYOND TUESDAY THOUGH DID BLEND IN SOME NEW 12Z WPC GUIDANCE
WITH OUR PREVIOUS FORECAST.
WE START OFF WITH BUILDING HEIGHTS AND MID-LEVEL RIDGING CONTINUING
TO WORKS ITS WAY IN FROM THE WEST. THIS SHOULD PROVIDE CLEAR SKIES
MONDAY MORNING PROVIDING GOOD RADIATIONAL COOLING CONDITIONS. WITH
THE HEIGHTS RISING SO DO THE TEMPERATURES...AGAIN. DAYTIME HIGHS
SHOULD BE A FEW DEGREES WARMER THAN ON SUNDAY...STILL NEARLY 10
DEGREES ABOVE NORMAL SO OUR THAWING WILL CONTINUE AND WE WILL REMAIN
DRY.
AS FOR NOW, WITH THE NEXT SYSTEM EXPECTED TO ENTER FROM THE WEST
LATE MONDAY NIGHT INTO TUESDAY, THE MID-LEVEL FLOW STILL KEEPS US
UNDER ITS SOUTHWEST INFLUENCE ALLOWING FOR BETTER MOISTURE ADVECTION
AND WARMER TEMPERATURES. AS THE FRONT NEARS RAIN WILL OVERSPREAD
FROM THE SOUTHWEST WITH STRONGER THETA-E ADVECTION AND THEN THE COLD
FRONT SWEEPS THROUGH. THE MID-LEVEL WAVELENGTH APPEARS RATHER LONG
AND THUS A QUICK EXIT IS EXPECTED WITH THIS SYSTEM.
THERE SHOULD BE A PCPN BREAK ON TUESDAY NIGHT BEFORE THE NEXT COLD
FRONT ARRIVES ON WEDNESDAY. HERE A MAJORITY OF THE GUIDANCE SHOWS
MORE OF A POSITIVE TILT TO THE TROUGHING AS IT NEARS FROM THE
WEST-NORTHWEST, THOUGH THE STRENGTH OF THE SYSTEM IS VARIABLE FROM
THE GFS TO THE EC TO THE NHGEM. AGAIN THE MID-LEVEL WAVELENGTH
APPEARS TO BE TOO LONG AND THE QUESTION THEN BECOMES CAN ENOUGH
ENERGY BE PUMPED INTO THE BACKSIDE OF THE TROUGH TO HELP IT SHARPEN
AND CUT ITS WAVELENGTH IN HALF...DOWNSTREAM BLOCKING DOES NOT SEEM
TO HELP THIS A QUICKER SHARPENING. THIS IS FAR FROM BEING ETCHED IN
STONE AND THIS ONE WOULD BE COLD ENOUGH TO HAVE SOME SNOW OCCUR.
AFTER THIS LOW DEPARTS, HIGH PRESSURE WILL BUILD INTO THE REGION.
WHILE TEMPERATURES SHOULD RETURN CLOSER TO NORMAL, THIS HIGH`S
ORIGIN IS FROM THE PACIFIC. SO UNLIKE LAST WEEK`S VERSION, THIS AIR
MASS HAS MORE OF ITS COLDNESS (RELATIVE TO NORMAL) IN THE UPPER HALF
OF THE TROPOSPHERE. THE NEXT COLD FRONT IS SCHEDULED FOR FRIDAY.
THIS ONE MAY BE MOISTURE STARVED. BUT THE ENSUING HIGH BEHIND THIS
FRONT IS COMING FROM WESTERN CANADA AND WILL BRING EVEN COLDER AIR
BACK INTO THE REGION. PLEASE DONT CURB YOUR ENTHUSIASM.
&&
.AVIATION /05Z SUNDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THE 06Z TAFS ARE PRIMARILY VFR. WE KEPT SOME MVFR CIGS EARLY AT
KMIV AND KACY UNTIL THE FRONT CLEARS THEM AROUND 07Z. ELSEWHERE A
VFR CIG STARTS THE TAFS ALONG WITH SOME GUSTINESS IN THE NEWFOUND
WESTERLY FLOW. FOG SHOULD NOT BE AN ISSUE ONCE THE FRONT CLEARS,
SO EVEN EASTERNMOST AIRPORTS ARE ABOUT TO LOSE ANY FOG PROBLEMS.
TOWARD MORNING WE DROP THE WIND GUSTS AND ALSO LOSE THE VFR CIG
MAKING IT EITHER CLEAR TOWARD THE COAST OR SCATTERED AT INLAND
AIRPORTS.
THIS MORNING, NORTHWEST WINDS SHOULD INCREASE AND AVERAGE CLOSE TO
15 KTS WITH GUSTS BETWEEN 20 AND 30 KTS. THIS WILL CONTINUE INTO
THE AFTERNOON. CLOUDS: WE DO BRING A TEMPORARY VFR CIG INTO KABE
AND KRDG. ELSEWHERE WE KEPT THE CU/SC DECK AT FEW/SCATTERED
COVERAGE. TOWARD THE COAST WE JUST MENTION SOME CIRRUS.
SUNDAY EVENING AND INTO THE EARLY OVERNIGHT. WINDS WILL DECREASE
RAPIDLY AND ANY CU OR SC CLOUDS WILL DISSIPATE. BY THE MIDDLE/LATE
EVENING MOST TERMINALS WILL HAVE LIGHT AND VARIABLE WINDS.
EXCEPTION IS KPHL WHERE WE BACKED THE (STILL LIGHTER) WINDS TO
THE SOUTHWEST.
OUTLOOK...
MONDAY...VFR. GUSTY SOUTHWEST WINDS DEVELOPING.
MONDAY NIGHT AND TUESDAY...VFR GIVING WAY TO POSSIBLE MVFR IN RAIN.
POSSIBLE RAIN/SNOW MIX WELL NORTH AND WEST OF ABE.
TUESDAY NIGHT...A VFR PERIOD. CONFIDENCE OF TIMING BETWEEN SYSTEMS
IS LOW.
WEDNESDAY...MVFR TO IFR CONDITIONS POSSIBLE. GUSTY NORTHWEST WINDS
LATER WEDNESDAY. CHANGEOVER FROM RAIN TO SNOW POSSIBLE...CONFIDENCE
IS LOW AT THIS POINT.
&&
.MARINE...
VERY LITTLE CHANGE ON THE AFTERNOON UPDATE. GALE WARNINGS CONTINUE
UNTIL 100 AM AND WILL BE FOLLOWED BY SMALL CRAFT ADVISORIES.
WIDESPREAD FOG WITH VISIBILITIES DOWN TO A HALF MILE (AND EVEN LOWER
IN SOME LOCATIONS) WILL CONTINUE UNTIL THE COLD FRONT PASSES THIS
EVENING.
SUNDAY...SMALL CRAFT CONDITIONS ARE EXPECTED...DIMINISHING LATE IN
THE DAY AS THE CAA WEAKENS AS DOES THE WESTERLY FLOW.
OUTLOOK...
MONDAY AND MONDAY NIGHT...POSSIBLE LOW END SMALL CRAFT ADVISORY
CRITERIA IN SOUTHERLY FLOW PRECEDING A COLD FRONT.
TUESDAY...NEAR SMALL CRAFT ADVISORY CRITERIA ON THE OCEAN AS ANOTHER
COLD FRONT MOVES THROUGH. SUB SMALL CRAFT ADVISORY CRITERIA ON
DELAWARE BAY.
TUESDAY NIGHT AND WEDNESDAY...A POSSIBLE SMALL CRAFT ADVISORY LULL
PERIOD WITH AN INCREASING LIKELIHOOD OF SMALL CRAFT ADVISORY CRITERIA
RETURNING BEHIND THE PASSAGE OF THE NEXT COLD FRONT.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...GALE WARNING UNTIL 1 AM EST EARLY THIS MORNING FOR ANZ430-431-
450>455.
&&
$$
SYNOPSIS...GIGI/MIKETTA
NEAR TERM...GIGI/SZATKOWSKI/O`HARA
SHORT TERM...SZATKOWSKI
LONG TERM...GIGI/HEAVENER
AVIATION...GIGI/HEAVENER
MARINE...GIGI/SZATKOWSKI/HEAVENER
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1226 AM EST Sun Jan 12 2014
...Updated Aviation Discussion...
...Forecast Update...
Issued at 940 PM EST Sat Jan 11 2014
Updated the forecast to tweak sky cover, temps, and dewpts. Also
removed patchy fog from south central KY. Observations revealed a
sfc trough over central IL/central IN moving southeast along with an
upper level shortwave on the back side of an upper trough which was
exiting the region. Latest RAP and gridded LAMP guidance indicates
we`ll see low clouds over southern Indiana as well as north central
and east central KY late tonight as these features pass through the
area. Tweaked skies grids to match the latest high-res models.
Took patchy fog out of south central KY since it looks like the
atmosphere will remain too mixy with the trough and shortwave
passing through and slightly drier air will advect in behind the
trough. Most high-res models agree, but the 0Z NAM does not.
Therefore, will need to keep an eye on things overnight in case the
NAM soln is correct.
Issued at 645 PM EST Sat Jan 11 2014
Did a quick forecast update to refresh temps/dewpts and adjust sky
cover some. Low clouds are making quicker progress eastward than
previously forecast. Still looks like we`ll see low clouds
re-enforced late tonight over southeast Indiana and portions of
north and east central KY late tonight as a final shortwave dives
down on the back side of the upper trough exiting the region.
.SHORT TERM (Now through Sunday Night)...
Issued at 245 PM EST Sat Jan 11 2014
The cold front has moved through the region this afternoon and
temperatures have fallen into the 40s with gusty westerly winds. For
tonight the upper level trough will swing across the area. Models do
show a shallow layer of moisture will remain, with perhaps enough
for light drizzle tonight across far northern portions of the
forecast area, though certainty for this is not high. For now just
have higher cloud cover across the northern portions of the area.
The other question will be the potential for some patchy fog across
south central Kentucky where clouds do clear out. This will be
highly dependent on cloud cover and winds. Temperatures tonight will
fall to near or just below freezing.
For tomorrow a progressive upper level and surface ridge will scoot
across the lower Ohio Valley. This will bring mostly sunny skies and
temperatures rising into the upper 40s to lower 50s. Clouds will be
on the increase tomorrow night as the next system begins to approach
the area, though we should stay dry overnight. Tempertures will fall
into the upper 30s to lower 40s.
.LONG TERM (Monday through Saturday)...
Issued at 255 PM EST Sat Jan 11 2014
Progressive but still somewhat amplified pattern will evolve into a
mean eastern CONUS trough by the end of the week, with an overall
trend back to below-normal temps.
The first in a series of disturbances will move through the Ohio
Valley late Monday, with a southern stream wave as the main player.
Some uncertainty over the degree of phasing with the northern
stream, but it is worth noting the GFS and ECMWF are in decent
agreement that phasing will occur, with the less phased NAM as an
outlier. Therefore will continue to favor the wetter solution with
likely POPs in south-central and east-central Kentucky, tapering
down to 30-40% over southern Indiana. Temps will be easily warm
enough to keep this all rain, but there is no instability to support
thunder with this system. Cold air will mainly be chasing the
moisture out of here Monday night, but we could see a changeover to
snow before the precip ends, mainly south of the Bluegrass region.
Tuesday looks to at least start mild and dry ahead of the next
disturbance, which will dive SE out of Canada. POPs will ramp up
late in the day, and we could see falling afternoon temps given what
should be a decent temp/dewpoint spread. Went with a rain/snow mix
to start, but will carry all snow Tuesday night as the cold air
spills in. Best chance for snow will be in southern Indiana late
Tuesday night, and the Bluegrass region during the day on Wednesday.
Could see a quick half inch of snow in these areas, and temps will
struggle to crack 30 degrees. This remains a lower probability event
as the latest Euro keeps the best forcing for a deformation band
cleanly to our north.
Quick rebound in temps Thursday under strong shortwave ridging, and
then another shot of cold air arrives on Friday with a deep upper
trof diving into the Great Lakes. Continuing to lean on the colder
ECMWF temps, even as this run starts to look a bit more progressive.
The 12Z ECMWF is still closer to its predecessors than to the much
more progressive GFS. High confidence that we will be near or below
freezing for highs on Friday, but there is some doubt as to how long
the cold air will stick around in the Ohio Valley. In this pattern
it`s difficult to rule out a few flurries, especially in the north
and east. However, moisture appears to be limited, so will not carry
flurries just yet. Coldest night will be Friday night. At this point
the cold air mass does not appear to pack the same punch as the cold
outbreak earlier this week, but it still bears watching for
unseasonable cold.
&&
.AVIATION (06Z TAF Update)...
Updated at 1225 AM EST Sun Jan 12 2014
Quiet TAF period in store as surface high pressure and weak upper
ridge dominate. Do have some concern about solid MVFR ceilings
working south toward SDF/LEX toward dawn, but higher res models have
a good handle currently and it looks like the ceiling should remain
just north of SDF. LEX may have a few hours just after dawn of
ceilings below fuel alternate. Otherwise, expect general winds
between WSW and S between 5 and 10 mph. Mostly sunny skies should
prevail for much of the afternoon.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Updates........AMS
Short Term.....EER
Long Term......RAS
Aviation.......BJS
AREA FORECAST DISCUSSION
NWS DULUTH MN
344 AM CST SUN JAN 12 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 343 AM CST SUN JAN 12 2014
THIS WAS A CHALLENGING SHORT TERM FORECAST. THE MAIN FOCUS IS ON
THE POTENTIAL FOR FREEZING RAIN AND A WINTRY MIXTURE OF PCPN THIS
MORNING WITH A WARM FRONT IN THE NORTHERN PLAINS EARLY THIS
MORNING THAT WILL MOVE THROUGH THE NORTHLAND TODAY. THIS WARM
FRONT WILL BE ASSOCIATED WITH A LOW PRESSURE SYSTEM MOVING EAST
ACROSS SOUTH CENTRAL CANADA. THE MODEL SOUNDINGS CONTINUE TO
INDICATE A SHORT PERIOD WHERE SNOW ALOFT WILL FALL INTO A
RELATIVELY WARM LAYER ABOVE FREEZING (AROUND 1 TO 4 DEGREES
CELSIUS)...RESULTING IN FREEZING RAIN AND/OR SLEET AS IT FALLS TO
THE COLD SURFACE...WHICH IS BELOW FREEZING THIS MORNING.
THE CHALLENGING PART THOUGH IS THAT THERE ARE STILL SIGNIFICANT
DIFFERENCES BETWEEN THE MODELS AS TO THE TRACK AND PCPN AMOUNTS
TODAY. I WAS HOPING FOR BETTER MODEL AGREEMENT BY NOW COMPARED TO
MY PREVIOUS SHIFT. THE GFS/GEM/ECMWF/RAP13/HRRR PRIMARILY BRING
THE PCPN THROUGH NE MINNESOTA. ON THE OTHER HAND...THE NAM/WRF/GEM
REGIONAL WERE PRIMARILY BRINGING THE PCPN THROUGH THE INTERSTATE
35 CORRIDOR AND NW WISCONSIN. THE GFS IS MUCH MORE AGGRESSIVE WITH
THE PCPN THAN MOST OF THE OTHER MODELS...AND THE 06Z NAM12 CAME IN
WITH NO PCPN. THIS IS QUITE THE RANGE OF DIFFERENCES. IT APPEARS
THE RAP13 AND HRRR MIGHT BE DOING FAIRLY WELL WITH THE CURRENT
PCPN IN THE NORTHERN PLAINS AT THIS POINT...SO I LEANING ON NE
MINNESOTA BEING THE MOST AFFECTED. HOWEVER...I EXPANDED THE
FREEZING RAIN ACCUMULATION AND WINTER WEATHER ADVISORY TO MUCH OF
NW WISCONSIN SINCE THIS AREA COULD EASILY GET A LIGHT COATING OF
ICE TO MAKE FOR DIFFICULT TRAVEL CONDITIONS.
I EXPECT MUCH OF NE MINNESOTA AND NW WISCONSIN TO GET A LIGHT
COATING OF ICE...AROUND A COUPLE HUNDREDTHS OF AN INCH...THIS
MORNING. SOME ISOLATED LOCATIONS COULD GET UP TO AROUND 5
HUNDREDTHS OF AN INCH DEPENDING ON ANY MORE INTENSE SHOWER BANDS
THAT SET UP. THIS WILL LIKELY CAUSE DIFFICULT TRAVEL CONDITIONS
THIS MORNING UNTIL CONDITIONS BEGIN TO IMPROVE THIS AFTERNOON WITH
THE WARMING TEMPERATURES AND AS THE PCPN BEGINS TO EXIT THE
NORTHLAND.
THE MODEL AND MOS GUIDANCE IS IN PRETTY GOOD AGREEMENT WITH HIGH
TEMPERATURES TODAY WITH WIDESPREAD HIGHS IN THE MID 30S. THE
ARROWHEAD WILL MORE LIKELY REACH THE LOW 30S...WHILE THE BRAINERD
LAKES AREA MORE IN THE UPPER 30S. THERE WILL LIKELY BE SOME
PARTIAL CLEARING THIS AFTERNOON IN THE WAKE OF THE WARM FRONT.
TONIGHT...THE CANADIAN LOW PRESSURE WILL MOVE INTO CENTRAL
ONTARIO...AND ITS COLD FRONT WILL MOVE THROUGH THE NORTHLAND. THIS
WILL BRING COLDER TEMPERATURES WITH LOWS DIPPING DOWN TO THE TEENS
AND SINGLE DIGITS ACROSS NE MINNESOTA. THERE COULD BE LIGHT SNOW
WITH LITTLE TO NO ACCUMULATION ACROSS MUCH OF NE MINNESOTA.
MONDAY...HIGH TEMPERATURES WILL BE SIGNIFICANTLY COLDER THAN TODAY
WITH HIGHS IN THE TEENS AND LOW 20S. THERE MIGHT BE LINGERING
LIGHT SNOW IN THE MORNING...AND THEN A WEAK RIDGE OF HIGH PRESSURE
IN THE NORTHERN PLAINS WILL SHIFT INTO THE NORTHLAND DURING THE
AFTERNOON. THIS COULD BRING SOME PARTIAL CLEARING DURING THE
AFTERNOON...BUT I LEANED ON THE CLOUDIER SIDE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 343 AM CST SUN JAN 12 2014
A SERIES OF DISTURBANCES WILL IMPACT THE NORTHLAND THROUGH THE
EXTENDED PERIOD.
A CLIPPER WILL MOVE SOUTHEAST THROUGH THE AREA MONDAY NIGHT INTO
TUESDAY MORNING BRINGING THE POTENTIAL FOR A COUPLE INCHES OF SNOW
TO ABOUT THE SOUTHERN HALF/THIRD OF THE NORTHLAND. THE MODELS ARE
IN BETTER AGREEMENT TONIGHT THAN 24 HOURS AGO...BUT DIFFERENCES
REMAIN. THE ECMWF/GFS ARE FURTHER NORTH WITH THE TRACK OF THE LOW
AND WITH THE PRECIP...BUT THE LATEST NAM HAS TRENDED A BIT FURTHER
SOUTH. WE RAISED POPS TO LIKELY OVER OUR FAR SOUTHERN
ZONES...WHERE THE BEST CHANCE FOR 1 TO 2 INCHES OF SNOW EXISTS.
SOME HIGHER SNOWFALL AMOUNTS WILL ALSO BE POSSIBLE IN THE SNOWBELT
OF ASHLAND/IRON COUNTIES MONDAY NIGHT INTO TUESDAY DUE TO COLDER
AIR MOVING OVER THE LAKE ON NORTHWEST LOW LEVEL FLOW.
MOST AREAS WILL BE DRY TUESDAY AFTERNOON INTO TUESDAY NIGHT AS A
RIDGE MOVES OVER THE REGION. LAKE EFFECT SNOW WILL CONTINUE TO
BE POSSIBLE OVER PORTIONS OF THE SNOWBELT OF ASHLAND/IRON
COUNTIES.
A STRONGER SYSTEM WILL START TO IMPACT THE NORTHLAND WEDNESDAY. A
SURFACE LOW WILL TRACK FROM MANITOBA WEDNESDAY EVENING SOUTHEAST
TOWARD EASTERN LAKE SUPERIOR/NORTHERN MICHIGAN BY THURSDAY
EVENING. A STRONG AREA OF WAA WILL OCCUR AHEAD OF THE LOW
WEDNESDAY...BRINGING A CHANCE FOR PRECIPITATION TO MUCH OF THE
NORTHLAND BY WEDNESDAY AFTERNOON OR WEDNESDAY NIGHT. WE RAISED
POPS WEDNESDAY INTO WEDNESDAY NIGHT FOR MOST AREAS...AS A PERIOD
OF PRECIPITATION IS LOOKING MORE LIKELY. AT THIS TIME...WE HAVE
HIGHEST POPS OVER NORTHERN MINNESOTA. THE SYSTEM DOES NOT LOOK
QUITE AS WARM AS EARLIER MODEL RUNS...BUT WE DID KEEP A MENTION OF
FREEZING RAIN OVER PORTIONS OF OUR SOUTHERN AREA WEDNESDAY
AFTERNOON. LIGHT TO MODERATE SNOW ACCUMULATIONS WILL BE POSSIBLE
FROM WEDNESDAY AFTERNOON INTO THURSDAY. A PERIOD OF WINDY
CONDITIONS WILL ACCOMPANY A COLD FRONTAL PASSAGE WEDNESDAY NIGHT
INTO THURSDAY. WE HAVE HIGH TEMPS THURSDAY FROM 20 ALONG THE
INTERNATIONAL BORDER TO THE MID TWENTIES ACROSS THE SOUTH. THESE
WILL LIKELY FALL THROUGH THE DAY AS STRONG COLD AIR ADVECTION
OCCURS.
NORTHERLY WINDS THURSDAY INTO FRIDAY WILL COMBINE WITH THE MUCH
COLDER AIR TO PRODUCE A PERIOD OF LAKE EFFECT SNOW SHOWERS ALONG
THE SOUTH SHORE...ESPECIALLY ASHLAND/IRON COUNTIES. THE POTENTIAL
FOR SIGNIFICANT SNOWFALL EXISTS THURSDAY INTO FRIDAY.
MOST AREAS LOOK TO BE DRY FRIDAY INTO THE WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1133 PM CST SAT JAN 11 2014
A MIX OF MVFR/IFR CEILINGS AROUND 800-1200 FT WILL PREVAIL THROUGH
THE EARLY MORNING AS MID LEVEL CEILINGS INCREASE FROM THE WEST.
A BRIEF WINDOW OF VFR IS EXPECTED THROUGH DAYBREAK AS A RIDGE OF
HIGH PRESSURE TRACKS OVER THE NORTHLAND. HAVE LOW LEVEL WIND SHEAR
LATE TONIGHT AT ALL MN TERMINALS AS 2 KFT WINDS INCREASE OUT OF
THE SOUTH AROUND 40 KT. A SURGE OF WARM MID- LEVEL AIR AHEAD OF A
FAST MOVING TROUGH WILL BRING A THREAT FOR -FZRA/-SN LATE TONIGHT
THROUGH SUNDAY MORNING. THE WINTRY PRECIP IS EXPECTED TO ARRIVE IN
THE KINL TO KBRD AREAS AFTER 10Z...TRANSLATING EAST TO THE
KHIB/KDLH TERMINALS AROUND 14Z. THE MIX OF -FZRA/SN IS EXPECTED TO
LAST FOR A 2-4 HR PERIOD WITH A LIGHT GLAZE OF ICE ACCUMULATION IN
THE KINL/KHIB/KDLH/KDLH AREAS THROUGH 18Z. AN ADDITIONAL INCH OR
SO OF SNOW IS LIKELY AT KINL AND KHIB. DUE TO MODEL INCONSISTENCY
IN PLACEMENT OF THE PRECIP...AND THE WARMER SFC TEMPS SUNDAY
AFTERNOON...CONFIDENCE IN PTYPE LOWEST IN KHYR AREA.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 34 16 19 6 / 40 10 10 30
INL 36 7 11 -4 / 40 30 20 10
BRD 38 15 18 10 / 40 10 10 70
HYR 37 21 23 8 / 40 10 20 70
ASX 36 21 23 8 / 40 10 10 50
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR MNZ037-038.
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR MNZ010-011-018-
019-025-026-033>036.
WINTER WEATHER ADVISORY FROM 8 AM THIS MORNING TO 2 PM CST THIS
AFTERNOON FOR MNZ012-020-021.
WI...WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR WIZ001-006.
WINTER WEATHER ADVISORY FROM 8 AM THIS MORNING TO NOON CST TODAY
FOR WIZ002-003-007-008.
LS...NONE.
&&
$$
SHORT TERM...GROCHOCINSKI
LONG TERM...MELDE
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1245 AM EST SUN JAN 12 2014
.SYNOPSIS...
A COLD FRONT WILL APPROACH WILL CROSS THE AREA TONIGHT. HIGH
PRESSURE WILL BUILD IN SUNDAY AND MOVE OFFSHORE MONDAY. LOW PRESSURE
WILL PASS NORTH OF THE AREA LATE TUESDAY DRAGGING A COLD FRONT
THROUGH THE REGION WEDNESDAY. HIGH PRESSURE WILL BRIEFLY BUILD IN
THURSDAY FOLLOWED BY ANOTHER COLD FRONT CROSSING FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1245 AM SUNDAY...COLD FRONT IS MOVING THROUGH THE EASTERN
PIEDMONT AND SHOULD REACH THE COAST OVER THE NEXT SEVERAL HOURS.
WITH RADAR COMPOSITES SHOWING SOME LIGHT SHOWERS ACROSS CENTRAL NC
AND WITH THE RAP AND 4 KM WRF SHOWING SOME LIGHT PRECIP POSSIBLE
OVER EASTERN NC...HAVE MAINTAINED SLIGHT CHC POPS THROUGH THE
EARLY MORNING HOURS. ALL PRECIP SHOULD BE OFFSHORE BY DAYBREAK.
TEMPS FALLING A BIT MORE SLOWLY THAN ANTICIPATED GIVEN THE
SLIGHTLY SLOWER MOVEMENT OF THE FRONT AND HAVE RAISED TEMPS BY A
DEGREE OR TWO FOR OVERNIGHT LOWS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TODAY/...
AS OF 215 PM SAT...HIGH PRES WILL BUILD IN SUNDAY WITH MOSTLY
CLEAR SKIES. GUSTY NW WINDS EARLY WILL GRAD DIMINISH AND BECOME
MORE WESTERLY LATE. HIGHS MAINLY 55 TO 60.
&&
.LONG TERM /TONIGHT THROUGH SATURDAY/...
AS OF 245 PM SATURDAY...A PROGRESSIVE PATTERN WILL CONTINUE
THROUGH THE LONG TERM WITH SEVERAL AMPLIFIED SYSTEMS MOVING
THROUGH THE FLOW ALOFT. HIGH PRES CENTERED OVER THE AREA SUN
EVENING WILL PUSH OFFSHORE LATE SUN NIGHT AND MON AS A ROBUST
SHORTWAVE TROUGH DIGS INTO THE SOUTHERN PLAINS. MODELS QUICKLY
DAMPEN THE SHORTWAVE AS IT LIFTS NE ACROSS THE AREA AND HAVE
SHIFTED THE LOW PRES CENTER FARTHER SOUTH FROM PREVIOUS RUNS...THE
MORE PROGRESSIVE AND DRIER GFS NOW OFF THE SE COAST AND WETTER
ECMWF ALONG THE SC/NC COAST. CONTINUE TO FAVOR THE ECMWF THROUGH
MUCH OF THE LONG TERM WITH PRECIP CHANCES INCREASING ACROSS THE
AREA MON NIGHT AND CONTINUING INTO TUES WITH THE COLD FRONT
PROGGED TO PUSH THROUGH TUES AFTERNOON. ALTHOUGH MODELS STILL
INDICATING STRONG LOW LEVEL SHEAR WILL BE IN PLACE...SEVERE
CHANCES APPEAR MINIMAL AT THIS TIME AS MODELS DEPICTING POSITIVE
LI`S ACROSS THE REGION. SOUTHERLY FLOW BRINGS ABOVE NORMAL TEMPS
MON THROUGH TUE WITH HIGHS IN THE 60S AND LOWS IN THE 40S.
A LONGWAVE UPPER TROUGH WILL REMAIN ACROSS THE EASTERN CONUS TUES
NIGHT WITH ANOTHER ROBUST UPPER TROUGH AND COLD FRONT PROGGED TO
PUSH ACROSS THE REGION WED AND WED NIGHT. FORCING AHEAD OF THIS
TROUGH COULD BRING ADDITIONAL RAIN CHANCES WED BUT MOISTURE WILL
BE LIMITED AND QPF AMOUNTS EXPECTED TO BE LIGHT. THE UPPER TROUGH
QUICKLY PUSHES OFFSHORE EARLY THURS WITH SHORTWAVE RIDGING AND SFC
HIGH PRES BRIEFLY BUILDING IN THURS. CYCLONIC FLOW RETURNS ALOFT
THURS NIGHT AND FRI WITH THE SFC HIGH PRES SLIDES OFFSHORE AHEAD
OF THE NEXT FRONTAL SYSTEM. MOISTURE LOOKS RATHER LIMITED WITH
THIS NRN STREAM SYSTEM AS WELL WITH MAINLY A DRY FRONTAL PASSAGE
FRI NIGHT. TEMPS AT OR SLIGHTLY BELOW SEASONAL NORMS LATE IN THE
WEEK WITH HIGHS IN THE MID 40S TO MID 50S AND LOWS IN THE UPPER
20S INLAND TO 30S COAST.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
SHORT TERM /THROUGH SUNDAY EVENING/...
AS OF 1245 AM SUN...MVFR CEILINGS EXPECTED AHEAD OF COLD FRONT
OVER THE NEXT FEW HOURS GIVEN A MOIST BOUNDARY LAYER. SKIES SHOULD
BECOME CLEAR BY DAYBREAK. SKC EXPECTED SUNDAY WITH WESTERLY WINDS
GUSTING 15-20 KNOTS DURING THE AFTERNOON.
LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 245 PM SATURDAY...VFR CONDITIONS SHOULD PREVAIL SUNDAY NIGHT
THROUGH MONDAY NIGHT WITH HIGH PRES RIDGING INTO THE AREA. LOW-LEVEL
MOISTURE INCREASES WITH SOME SUB-VFR CONDITIONS POSSIBLE IN
SCATTERED LIGHT SHOWERS LATE MONDAY NIGHT INTO TUESDAY. COLDER AND
DRIER AIR RETURNS FOR MIDWEEK AND ALTHOUGH SOME ISOLATED SHOWERS MAY
ACCOMPANY A SECONDARY FRONTAL PASSAGE ON WEDS...ALTHOUGH EXPECT VFR
CONDITIONS TO PREVAIL.
&&
.MARINE...
SHORT TERM /THROUGH SUNDAY/...
AS OF 1245 AM SUNDAY...WINDS REMAIN SW BUT SHOULD VEER TO NW AS
COLD FRONT PASSES OVER THE NEXT FEW HOURS AND WITH STRONG
CAA...WIND SPEEDS SHOULD INCREASE TO 20 TO 25 KNOT OVER THE
COASTAL WATERS AND SOUNDS BY MORNING. ON SUNDAY THE NW WINDS WILL
GRAD DIMINISH AND BECOME W 10 TO 15 KT LATE. SEAS...WHICH ARE
CURRENTLY IN THE 6 TO 8 FOOT RANGE...SHOULD GRADUALLY DROP BELOW 6
FEET FOR ALL BUT THE OUTER CNTRL WTRS BY LATE SUNDAY.
LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 245 PM SATURDAY...LIGHT WINDS EXPECTED SUN NIGHT WITH HIGH
PRES OVER THE AREA. WINDS WILL BECOME S/SW UP TO 15-20 KT MON
AHEAD OF THE NEXT FRONTAL SYSTEM WHILE SEAS WILL REMAIN AROUND 3-5
FT. WINDS/SEAS INCREASE FURTHER LATE MON NIGHT TUE JUST AHEAD OF
THE FRONT...UP TO 25 KT WITH SEAS AROUND 4-7 FT. SOME TIMING
DIFFERENCES AMONG THE MODELS FOR THE FRONTAL PASSAGE WITH THE MORE
PROGRESSIVE GFS PUSHING THE FRONT THROUGH EARLY IN THE DAY...BUT
THE PREFERRED ECMWF AND NAM DELAY FROPA UNTIL LATE AFTERNOON/EARLY
EVENING. WINDS BECOME W 5-15 KT TUE NIGHT WITH SEAS SUBSIDING TO
3-5 FT. WINDS QUICKLY BACK TO SW AND INCREASE TO 15-25 KT WED
AHEAD OF A SECONDARY FRONT PROGGED TO MOVE ACROSS THE WATERS WED
AFTERNOON/EVENING. STRONGER CAA BEHIND THIS FRONT WILL KEEP WINDS
ELEVATED...NW AROUND 15-25 KT...INTO THURS MORNING. SEAS GENERALLY
3-6 FT WED INTO THURS MORNING. WINDS DIMINISH SOME THURS
AFTERNOON...THEN BACK TO SW AROUND 10-20 KT THURS NIGHT WITH SEAS
GENERALLY 2-5 FT.
&&
.CLIMATE...
ACCORDING TO OUR 530 PM CLIMATE DATA...CAPE HATTERAS HAS TIED THE
PREVIOUS HIGH TEMPERATURE RECORD OF 70 DEGREES ORIGINALLY SET IN
1890.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EST THIS MORNING FOR AMZ130-
135.
SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR AMZ152-
154.
SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR AMZ150-
156-158.
&&
$$
SYNOPSIS...RF
NEAR TERM...CTC
SHORT TERM...RF
LONG TERM...SK
AVIATION...CTC/SK/DAG
MARINE...CTC/RF/SK/DAG/BM
CLIMATE...BM
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
219 AM CST SUN JAN 12 2014
.UPDATE...
ISSUED AT 220 AM CST SUN JAN 12 2014
WE ARE GETTING SOME ICING REPORTS ENTERING THE WESTERN FORECAST
AREA...AND RADAR RETURNS ARE INCREASING. THE RAP SEEMS TO
INITIALIZE WELL...AND BRINGS FREEZING RAIN FROM WEST TO EAST
THROUGH 15Z...AFFECTING AREAS ALONG AND SOUTH OF HIGHWAY 2. WE
HAVE ISSUED A FREEZING RAIN ADVISORY FOR THIS HAZARD.
UPDATE ISSUED AT 1151 PM CST SAT JAN 11 2014
WARM ADVECTION PRECIPITATION CONTINUES TO MOVE EAST. RADAR INDICATED
VERY LIGHT FREEZING RAIN IN WESTERN/CENTRAL ND. TEMPERATURES
CONTINUE TO RISE FROM THE WEST AS WELL AS INCREASING SOUTH/SOUTHWEST
WINDS OVERNIGHT. OVERNIGHT LOWS SHOULD HAVE ALREADY OCCURRED THIS
EVENING. PRECIPITABLE WATER RISES TO BETTER THAN HALF AN INCH
OVERNIGHT THEN DECREASES FROM THE WEST IN THE MORNING. NO CHANGES
THIS UPDATE.
UPDATE ISSUED AT 1000 PM CST SAT JAN 11 2014
UPPER AIR PATTERN FORECAST TO BE QUITE PROGRESSIVE NEXT COUPLE DAYS.
UPPER LEVEL RIDGE AXIS WAS LOCATED OVER THE CENTRAL DAKOTAS AND WILL
MOVE INTO SOUTHEAST CANADA BY SUN AFTERNOON.
PATCHY FOG HAD DEVELOPED OVER MN SIDE OF THE RED RIVER. HOWEVER MID
LEVEL CLOUDS WERE THICKENING ON THE MN SIDE AND VISIBILITIES WERE
INCREASING. WILL NOT MENTION ANY PATCHY FOG.
BIS OBSERVED SOUNDING INDICATED MOIST LAYER MOVING IN AROUND 600-700
HPA AND RELATIVELY DRY ATMOSPHERE BELOW 700 HPA. SOME PRECIPITATION
HAS BEEN REPORTED IN WESTERN ND. HOWEVER ONLY TRACE AMOUNTS HAVE
BEEN REPORTED. CLOUD CEILINGS REMAINS ABOVE 6 TO 7 THOUSAND FT.
NO PLANS TO ISSUE AN ADVISORY UNLESS CONDITIONS DETERIORATE.
UPDATE ISSUED AT 702 PM CST SAT JAN 11 2014
TEMPERATURES ARE FALLING QUICKLY WHERE EITHER A CLEAR OR THIN CIRRUS
WAS OVER THE AREA. WILL RAISE TEMPS A BIT IN THE FAR WESTERN ZONES.
WILL LOWER TEMPS FROM NEAR LANGDON TO NEAR PKD.
AREA RADARS INDICATED LIGHT PRECIPITATION IN WESTERN ND BUT DOES NOT
APPEAR TO BE REACHING THE GROUND. NO OBS SITE REPORTED PRECIP IN THE
WESTERN ND. MODELS MAINTAIN A DRY LAYER BETWEEN ABOUT 7 THOUSAND
FT AND THE SURFACE. SO WILL HOLD OFF ANY ANY ADVISORIES AT THIS
TIME OR FREEZING RAIN. WILL RE-EVALUATE AT 10 PM UPDATE.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 346 PM CST SAT JAN 11 2014
THE MAIN CHALLENGE WILL BE FAST MOVING SYSTEMS IN NW FLOW
ALOFT...PRECIP TYPE AND WIND SPEEDS THROUGH THE FORECAST. MODELS
ARE IN GENERAL AGREEMENT AND A GFS/ECMWF BLEND WAS USED FOR THIS
FORECAST.
FOR TONIGHT...STRONG WAA WILL BEGIN AT ALL LEVELS AS A POTENT
SHORTWAVE FROM THE PACIFIC NW MOVES THROUGH THE REGION. THERE
SHOULD BE A BAND OF FREEZING RAIN/SLEET WITH TEMPS ALOFT WELL
ABOVE 0C...BUT NOT EXPECTING TOO MUCH QPF GIVEN FAST MOVEMENT OF
SYSTEM. EXPECTING THE PCPN TO CREATE VERY ICY CONDITIONS BY
SUNDAY MORNING...AND HAS BEEN HIGHLIGHTED IN THE SPS.
ON SUNDAY...THERE SHOULD BE SOME MORNING FREEZING RAIN/RAIN MAINLY
IN THE SOUTH...THEN IT WILL BE VERY MILD WITH ALL AREAS ABOVE
FREEZING. IT COULD REACH THE UPPER 30S IN THE SOUTH WITH
FAVORABLE FLOW AS STRONG LOW PRESSURE PASSES NORTH OF THE REGION
ACROSS SOUTHERN CANADA.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 346 PM CST SAT JAN 11 2014
FOR MONDAY AND MON NIGHT...IT SHOULD BE COOLER THAN RECENT DAYS WITH
TEMPS STRUGGLING TO REACH 10 ABOVE IN MOST AREAS. TEMPS COULD EVEN
BE A BIT COOLER THAN FCST. OTHERWISE...SOME LIGHT SNOW IS POSSIBLE
WITH A CLIPPER TYPE SYSTEM MOVING THROUGH THE REGION...WITH PERHAPS
AN INCH OR 2 OF SNOW POSSIBLE.
TUESDAY NIGHT THROUGH SATURDAY...12 UTC GFS/ECMWF IN VERY GOOD
AGREEMENT BOTH SHOWING A STRONG NORTHERN PACIFIC SHORT-WAVE BREAKING
DOWN AND MOVING THROUGH THE WESTERN NOAM RIDGE...IMPACTING THE
NORTHERN PLAINS WED/THURS. WARM FRONT WILL PUSH ACROSS THE FORECAST
AREA WEDNESDAY WITH 850 HPA TEMPERATURES RISING WELL ABOVE ZERO
CELSIUS IN ITS WAKE. MODELS PAINT THE MAJORITY OF FRONTAL
PRECIPITATION ACROSS THE NORTHERN VALLEY INTO NORTH-CENTRAL MN...
BUT THERMAL PROFILES ARE FAVORABLE FOR FREEZING RAIN SO WILL ADD
MIXED PRECIPITATION TO WEATHER GRIDS WEDNESDAY AFTERNOON AND
EVENING. ANY PRECIPITATION WILL CHANGE OVER TO SNOW WEDNESDAY NIGHT
WITH COLD FRONTAL PASSAGE...BUT BIGGER IMPACT WILL BE VERY STRONG
NORTHWESTERLY WIND. GFS/ECMWF BOTH SHOW 40 TO 50 KTS AT 925 HPA
WEDNESDAY NIGHT AND THURSDAY ALONG AND WEST OF THE VALLEY AS THE
PRIMARY SURFACE LOW MOVES ACROSS SOUTHERN ONTARIO. THERE MAY NOT BE
MUCH FALLING SNOW CONCURRENT WITH THE HIGHEST WIND SPEEDS...BUT IT
MAY BE STRONG ENOUGH TO STILL CREATE HEADACHES AT THE SURFACE WITH
BLOWING AND DRIFTING SNOW. SOMETHING TO WATCH CAREFULLY OVER THE
NEXT SEVERAL DAYS. FRIDAY/SATURDAY WILL BE DRY.
TEMPERATURE-WISE...AFTERNOON HIGHS WILL PEAK IN THE MID 20S TO LOWER
30S ON WEDNESDAY IN THE SYSTEM/S WARM SECTOR WITH COOLER CONDITIONS
FOR THE LATTER HALF OF THE WEEK. BY FRIDAY EXPECT HIGHS GENERALLY IN
THE TEENS WITH MORNING LOWS IN THE SINGLE DIGITS BELOW ZERO. A
SLIGHT WARM-UP WILL COMMENCE FOR THE BEGINNING OF THE WEEKEND AS THE
WESTERN NOAM RIDGE REASSERTS ITSELF ACROSS THE CONTINENT/S MID-
SECTION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1151 PM CST SAT JAN 11 2014
FOG LOOP INDICATED THE TRAILING EDGE OF IFR/MVFR CIGS OVER NORTHEAST
ZONES WERE MOVING NORTHEAST AROUND 5 KNOTS. MUCH OF CLOUD DECK IS
NOW OBSCURED BY HIGHER CLOUDS ON LOOP. FEW CIGS AROUND 25 HUNDRED FT
WERE AT CAVALIER ND OTHERWISE MOST SITES ARE ABOVE 5 THOUSAND FT IN
THE NORTHWESTERN ZONES TO 12 THOUSAND FT IN THE SOUTHERN ZONES.
EXPECT IFR/MVFR CIGS TO CONTINUE SLOWLY MOVING NORTHEAST. REST OF
THE AREA SHOULD HAVE VFR CIGS THROUGH SUNRISE EXCEPT NEAR RAIN
SHOWERS. SOME CLEARING EXPECTED SUN MORNING.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...FREEZING RAIN ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR
NDZ024-026>030-038-039-049-052-053.
MN...FREEZING RAIN ADVISORY UNTIL 9 AM CST THIS MORNING FOR MNZ009-
013>017-022>024-027-028-030>032-040.
FREEZING RAIN ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR
MNZ001>003-029.
&&
$$
UPDATE...DK
SHORT TERM...HOPKINS
LONG TERM...ROGERS
AVIATION...HOPPES
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1232 AM EST SUN JAN 12 2014
.SYNOPSIS...
A COLD FRONT WILL PROGRESS ACROSS THE AREA THIS EVENING AND BE
WELL OFF THE ATLANTIC COAST BY SUNDAY MORNING. HIGH PRESSURE WILL
BUILD INTO THE REGION FOR THE REMAINDER OF THE WEEKEND. A WARM
FRONT WILL LIFT ACROSS THE AREA ON MONDAY...FOLLOWED BY A COLD
FRONT ON TUESDAY INTO WEDNESDAY.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 920 PM EST SATURDAY...
A FEW OF THE SHOWERS ALONG AND AHEAD OF THE FRONT ARE GROWING TALL
ENOUGH TO BECOME THUNDERSTORMS AND PRODUCE SOME SMALL HAIL. HAVE
BEEN ACCOUNTING FOR THIS IN SPECIAL WEATHER STATEMENTS. THE LATEST
FORECAST UPDATE WILL INCLUDE THIS POTENTIAL AS WELL FOR THE NEXT
HOUR OR TWO. NO MAJOR ADDITIONAL ADJUSTMENTS AT THIS TIME. HAVE
ONLY TWEAKED HOURLY TEMPERATURES AND DEW POINTS TO REFLECT THE
LATEST OBSERVATIONS AND EXPECTED TRENDS INTO THE EARLY MORNING
HOURS.
AS OF 650 PM EST SATURDAY...
SHOWERS ALONG THE COLD FRONT ARE CONTINUING TO PROGRESS EASTWARD
THROUGH THE AREA. A LOOK AT THE LOCAL WRF AND HRRR MODELS ARE
CAPTURING THIS ACTIVITY...AND OFFER A SOLUTION THAT BRINGS AT
LEAST ISOLATED COVERAGE ACROSS THE ENTIRE REGION COINCIDENT TO THE
FRONT. HAVE UPDATED THE FORECAST TO REFLECT THIS. NO OTHER
SIGNIFICANT CHANGES HAVE BEEN MADE.
AS OF 525 PM EST SATURDAY...
INSTABILITY HAS DEVELOPED IN THE DRY SLOT IMMEDIATELY COINCIDENT
TO THE COLD FRONT. ENOUGH HEATING HAS ALLOWED FOR SOME SCATTERED
SHOWERS TO DEVELOP OVER WEST VIRGINIA THAT ARE PROGRESSING INTO
THE WESTERN PORTION OF THE FORECAST AREA. AM NOT ANTICIPATING THE
SHOWERS TO MAKE A LOT OF PROGRESS AND DISSIPATE AROUND SUNSET.
AS OF 315 PM EST SATURDAY...
A COLD FRONT WAS ABOUT TO ENTER THE WESTERN PORTIONS OF THE FORECAST
AREA. PRECIPITATION HEAD OF IT WAS BECOMING CONFINED TO PRIMARILY
THE EASTERN HALF OF THE REGION AND PROGRESSING EASTWARD VERY
QUICKLY. ANTICIPATE THAT THE BACK EDGE OF THE PRECIPITATION WILL
EXIT THE EASTERN PART OF THE FORECAST AREA BY 800 PM EST. BEHIND THE
COLD FRONT...WINDS WILL SHIFT NORTHWEST AND BECOME GUSTY THROUGH THE
OVERNIGHT HOURS...ESPECIALLY ACROSS THE MOUNTAINS. 850 MB WINDS ARE
PROGGED TO PEAK BETWEEN 45 AND 50 KTS WITH AN ORIENTATION THAT GIVES
GOOD CROSS-BARRIER FLOW. WE ARE EXPECTED WIND ADVISORY CRITERIA
GUSTS ACROSS THE HIGHER TERRAIN OF THE NORTHERN MOUNTAINS OF NORTH
CAROLINA...NORTH INTO GRAYSON COUNTY VIRGINIA. THE PRESSURE GRADIENT
AND SUBSEQUENT 850 WINDS ARE PROGGED TO DECREASE QUICKLY DURING THE
FORENOON SUNDAY...THUS THE 900 PM END TIME FOR THE ADVISORY. THESE
SAME NORTHWEST WINDS WILL BE WEAKER ACROSS THE PIEDMONT...AND HELP
TO ERODE THE CLOUD COVER THANKS TO THE GENERATED SUBSIDENCE.
THE NORTHWEST FLOW AND LINGERING LOW LEVEL MOISTURE WILL HELP TO
GENERATE SOME UPSLOPE PRECIPITATION ACROSS SOUTHEAST WEST VIRGINIA
SOUTH INTO THE NORTHERN MOUNTAINS OF NORTH CAROLINA. WHILE WE WILL
MENTION SOME SNOW SHOWERS WHERE TEMPERATURES FALL LOW
ENOUGH...CONFIDENCE IN SNOW OCCURRING IS NOT VERY HIGH. PLENTY OF
DRY AIR WILL WORK INTO THE AREA BETWEEN ROUGHLY THE -6 C TO -25 C
RANGE...SO THERE LIKELY WILL NOT BE ANY ICE CRYSTALS FOR DENTRITIC
GROWTH. WILL MENTION THE POTENTIAL FOR DRIZZLE OR FREEZING DRIZZLE
GIVEN THE LOCAL TEMPERATURE. HOWEVER...HIGH LEVEL CLOUD COVER ABOVE
THIS DRY LAYER MAY HELP TO PROVIDE FOR SOME SEEDER FEEDER SNOW
PRODUCTION...BUT THE POTENTIAL FOR THAT IS ALSO ON THE LOW SIDE.
HAVE GONE FAIRLY CLOSE TO GUIDANCE ADJUSTED FOR LOCAL BIASES FOR THE
OVERNIGHT LOWS. THIS OFFERS LOWS OF THE LOW TO MID 30S OVER THE
MOUNTAINS WITH MID TO UPPER 30S ACROSS THE PIEDMONT.
ON SUNDAY...THE NORTHWEST WINDS WILL CONTINUE THROUGH ABOUT MIDDAY
BEFORE THEY WEAKEN AND BACK SOUTHWEST AS AN UPPER RIDGE STARTS TO
DEVELOP OVER THE REGION. WE EXPECT PLENTY OF DRY AIR TO CONTINUE
ADVECTING INTO THE AREA...AND THE TREND FOR ERODING CLOUD COVER WILL
TAKE PLACE ACROSS THE MOUNTAINS. HAVE FAVORED A BLEND OF THE MAV AND
MET MOS NUMBERS ADJUSTED FOR LOCAL BIASES FOR THE HIGH TEMPERATURES.
THIS WILL PLACE MID TO UPPER 40S ACROSS MOST OF THE MOUNTAIN
COUNTIES AND LOW TO MID 50S ACROSS THE PIEDMONT.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
AS OF 300 PM EST SATURDAY...
WILL START SUNDAY EVENING WITH A WEAK UPPER LEVEL RIDGE CROSSING THE
APPALACHIANS...WHILE HIGH PRESSURE IN THE LOW LEVELS MOVES OFFSHORE
FROM THE SOUTHEASTERN STATES. SOUTHWESTERLY FLOW AROUND THE
DEPARTING HIGH WILL DRAW WARM GULF AIR INTO OUR REGION...PUSHING
MONDAY AFTERNOON HIGHS INTO THE MID TO UPPER 50S FOR MOST
LOCATIONS... SEVERAL DEGREES ABOVE SEASONAL NORMALS.
THE UPPER RIDGE WILL BE MAKING A QUICK EXIT MONDAY AFTERNOON...IN
FAVOR OF AN UPPER LEVEL TROUGH AND ASSOCIATED COOL FRONT APPROACHING
FROM THE UPPER MIDWEST. LATEST FORECAST MODELS INDICATE THE TROUGH
IS NOT AS SHARP OR NEGATIVELY TILTED AS INDICATED IN PREVIOUS MODEL
RUNS...AND AM NO LONGER CONTEMPLATING THE POSSIBILITY OF
THUNDERSTORMS ACROSS THE SOUTHSIDE MONDAY NIGHT. PRECIPITATION IS A
GOOD BET HOWEVER...AND TEMPERATURES WILL BE WARM ENOUGH THROUGH THE
NIGHT TO SUPPORT RAIN.
THE COOL FRONT WILL PUSH THROUGH THE REGION EARLY TUESDAY MORNING...
BRINGING TUESDAY AFTERNOON HIGHS CLOSER TO SEASONAL NORMALS. WILL
SEE BRIEF PERIOD OF MAINLY DRY WEATHER TUESDAY AFTERNOON...BEFORE
OUR NEXT UPPER LEVEL TROUGH AND ASSOCIATED COLD FRONT ARRIVE TUESDAY
NIGHT. THIS TROUGH WILL BE COLDER THAN THE PREVIOUS SYSTEM
AND...WHILE THERE WILL NOT BE A GREAT DEAL OF MOISTURE FOR IT TO
WORK WITH...IS EXPECTED TO CAUSE RAIN SHOWERS TO CHANGE OVER TO SNOW
IN THE MOUNTAINS DURING THE EARLY MORNING HOURS OF WEDNESDAY. ANY
SNOW ACCUMULATIONS ARE EXPECTED TO BE LIGHT...AND CONFINED TO MAINLY
THE HIGHER RIDGES IN SOUTHEAST WEST VIRGINIA.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 300 PM EST SATURDAY...
POLAR VORTEX/EASTERN U.S. TROUGHING WILL PREVAIL DURING THE MEDIUM
RANGE. NORTHWEST FLOW ALOFT WILL DOMINATE THROUGH THE MUCH OF THE
PERIOD...AS THE MAIN TROUGH AXIS GRADUALLY PIVOTS NORTHEAST OF THE
REGION. A COUPLE OF ALBERTA CLIPPERS WILL ROTATE EASTWARD THROUGH
THE MEAN TROUGH WITH LIMITED MOISTURE. IN GENERAL...EXPECT
SEASONABLY COOL TEMPERATURES THROUGH THE PERIOD. UPSLOPE CLOUDS AND
COLDER TEMPERATURES ARE ON TAP FOR THE MOUNTAINS...WHILE SUNSHINE
WILL RESULT IN WARMER READINGS FOR THE EAST. KEPT THE HIGHEST POPS
ON WEDNESDAY IN THE NORTHWEST AS A WAVE TRAVEL ACROSS REGION. STILL
LOOK LIKE MOST OF THE MOISTURE WILL RIDE NORTHEAST OF OUR AREA. THE
FRONT PUSHES OFF TO THE EAST AND A DRY HIGH PRESSURE BUILDS IN FROM
THE WEST BY THURSDAY. ANOTHER MOISTURE-STARVED SURFACE COLD FRONT
WITH ARRIVES AROUND FRIDAY...FOLLOWED BY HIGH PRESSURE ON SATURDAY.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 635 PM EST SATURDAY...
SKY COVER OVERNIGHT WILL TREND TO VFR EAST OF THE CREST OF THE
RIDGE THANKS TO GOOD DOWNSLOPING BEHIND FRONT. ACROSS THE
MOUNTAINS A MIX OF MVFR ALONG WESTERN SLOPES TO LOW-END VFR
CLOUDS ARE EXPECTED THROUGH 12Z/7A SUNDAY. SOME LIGHT SNOW OR
DRIZZLE OR FREEZING DRIZZLE IS POSSIBLE ACROSS SOUTHEAST WEST
VIRGINIA SOUTH INTO THE NORTHERN MOUNTAINS OF NORTH CAROLINA. ALL
AREAS ARE EXPECTED TO BE VFR BY LATE SUNDAY MORNING. GUSTY
NORTHWEST WINDS WILL PREVAIL ACROSS THE MOUNTAINS OVERNIGHT WITH
THE HIGHER PEAKS APPROACHING 40 TO 45 KTS. WINDS WILL DECREASE
THROUGH THE DAY SUNDAY...AND LOW LEVEL WINDS BACK AND AN UPPER
RIDGE STARTS TO BUILD OVER THE AREA.
EXTENDED AVIATION FORECAST...
THE NEXT LOW PRESSURE SYSTEM IS PROJECTED TO ARRIVE BY MONDAY
NIGHT INTO TUESDAY MORNING...WHICH WOULD BRING SOME MVFR
CONDITIONS AND RAIN SHOWERS IN THE PIEDMONT...WITH A FEW SNOW
SHOWERS POSSIBLE IN THE MOUNTAINS. THE LONG RANGE MODELS SHOW A
SMALL CLIPPER SYSTEM TRACKING OVER THE MID ATLANTIC BY TUESDAY
NIGHT INTO WEDNESDAY. SOME UNCERTAINTY STILL EXISTS WITH THIS
COMPACT FEATURE...BUT IT WILL BE WORTH WATCHING AS SOME
ACCUMULATING SNOW MAY OCCUR FOR BLF/LWB ON WEDNESDAY...AND EVEN
BCB/ROA MAY SEE A FEW SNOW SHOWERS. OTHERWISE...VFR CONDITIONS
SHOULD PREVAIL ACROSS THE PIEDMONT FOR MOST OF NEXT WEEK...WHILE
MVFR CONDITIONS MAY BE MORE LIKELY IN THE MOUNTAINS DURING
WEDNESDAY AND THURSDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WIND ADVISORY UNTIL 9 AM EST THIS MORNING FOR VAZ015.
NC...WIND ADVISORY UNTIL 9 AM EST THIS MORNING FOR NCZ001-018.
WV...NONE.
&&
$$
SYNOPSIS...DS
NEAR TERM...DS
SHORT TERM...NF
LONG TERM...KK
AVIATION...DS
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
855 AM MST SUN JAN 12 2014
.UPDATE...
&&
.SHORT TERM...UPPER LEVEL TROF OVER EASTERN UTAH AND STRONG JET
MOVING OVER COLORADO WITH BATCH OF HEAVY SNOW DEVELOPING OVER
NORTH CENTRAL MOUNTAINS. WARNINGS ALREADY IN PLACE AND ONGOING
FORECAST LOOKS GOOD IN THE MOUNTAINS. SURFACE FRONT CONTINUES TO
PUSH SOUTH OVER THE DENVER AREA WITH GUSTY NORTHERLY WINDS
DEVELOPING BEHIND IT. THIS TIMING IS A LITTLE QUICKER THAN
PREVIOUS FORECAST SO HAVE BEEFED UP THE WINDS THIS MORNING. WITH
COLD ADVECTION THIS AFTERNOON...GOOD MIXING WILL ALLOW STRONG NW
WINDS TO DEVELOP OVER MUCH OF THE AREA. COULD CERTAINLY SEE SOME
GUSTS IN THE 30-50 MPH RANGE AND HAVE ALSO INCREASED THE WINDS ON
THE PLAINS. LATEST RAP AND HRRR SHOWING SOME QPF OVER THE PALMER
DIVIDE AND EAST AND SOUTH OF DENVER. SO HAVE ADDED SOME LOW POPS
FOR NOW.
.AVIATION...SURFACE FRONT PUSHING SOUTH THROUGH TERMINAL WITH
NORTH TO NORTHEAST WINDS BEHIND IT. WINDS WILL DIMINISH A BIT LATE
AM BEFORE INCREASING AGAIN FROM THE NORTHWEST THIS AFTERNOON WITH
STRONG MIXING EXPECTED IN THE LOW LEVELS. WILL LEAVE TERMINALS DRY
FOR NOW BUT WILL HAVE TO WATCH THE SHOWER DEVELOPMENT POSSIBLE
EAST AND SOUTH OF APA.
&&
.PREV DISCUSSION... /ISSUED 259 AM MST SUN JAN 12 2014/
SHORT TERM...FOR TODAY...A STRONG WESTERLY FLOW ALOFT WILL BE
OVER THE CWFA AS THE NEXT STORM SYSTEM PASSES ACROSS CO. THE
TROUGH AXIS WILL MOVE ACROSS EASTERN COLORADO BY EARLY AFTERNOON
WITH THE FLOW ALOFT BECOMING MORE WNWLY. SNOWFALL WILL REDEVELOP
ACROSS THE NORTH CENTRAL MOUNTAINS THIS MORNING...WITH INCREASING
MID AND UPPER LEVEL QG ASCENT AHEAD OF THE TROUGH AXIS. IN
ADDITION AN 110KT JET MAX WILL SHIFT ACROSS CO THIS MORNING AHEAD
OF THE TROUGH. STRONG WINDS HAVE PERSISTED OVERNIGHT WITH GUSTS TO
NEAR 80 MPH AOA 12K FT. BY THIS AFTN...STRONG QG DESCENT AND MID
LEVEL COLD AIR ADVECTION KICKS IN. BORA TYPE SETUP WITH STRONG
WINDS AND SNOW IN THE MOUNTAINS...ESPECIALLY THIS AFTN AND
EVENING. PERIOD OF THE BEST SNOW WILL BE FM BETWEEN 18Z THIS AFTN
AND 06Z TONIGHT. AS A RESULT...NO CHANGES REGARDING THE WINTER
STORM WARNING FOR TODAY AND TONIGHT. SNOWFALL WILL BE DRIVEN BY
PRIMARILY OROGRAPHICS AFTER 21Z THIS AFTN...WITH HEAVIEST SNOWFALL
EXPECTED ALONG WEST FACING SLOPES. THE HIGH WIND THREAT FOR THE
FOOTHILLS WILL RETURN THIS AFTN AND TONIGHT. MOUNTAIN WAVE
REDEVELOPS TONIGHT...WITH THE MOST FAVORABLE WAVE AMPLIFICATION
AFTER 06Z TONIGHT. STRONG BORA WINDS THIS AFTN AND EVENING WILL BE
A PRODUCT OF STRONG WINDS ALOFT...AND DOWNWARD TRANSPORT THROUGH
SUBSIDENCE AND MIXING THRU COLD AIR ADVECTION. OVERNIGHT TONIGHT
..KDEN-KGJT SFC PRESSURE GRADIENT WILL INTENSIFY WITH RIDGETOP
WINDS OF 70KTS WITH A MEAN STATE CRITICAL LAYER OF 10KTS OR LESS
AT 550 MB. FOR THE URBAN CORRIDOR AND NORTHEAST PLAINS...DRY BUT
VERY WINDY THIS AFTN FOLLOWING THE PASSAGE OF THE MID LEVEL TROUGH
AXIS. THE WIND WILL BE STRONGEST NEAR THE FOOTHILLS AND NEAR THE
WYOMING AND NEBRASKA BORDERS. ZONES 38 AND 39 WILL NEED TO BE
MONITORED FOR HIGH WIND ESPECIALLY AFTER MIDNIGHT TONIGHT. FOR
NOW...WILL STICK WITH THE CURRENT HIGHLIGHTS AND LET THE DAY SHIFT
ASSESS THE WIND POTENTIAL THERE.
LONG TERM...MONDAY THROUGH SATURDAY...THE LARGE SCALE WEATHER
PATTERN WILL STAGNATE NEXT WEEK ACROSS THE COUNTRY. A LONG WAVE
TROUGH WILL BE OVER THE EASTERN PART OF THE COUNTRY WITH A RIDGE
OVER THE WESTERN STATES. THIS PATTERN WILL LEAVE COLORADO UNDER A
NORTHWESTERLY FLOW THROUGH THE WEEK.
A STRONG AND SOMEWHAT MOIST NORTHWEST FLOW ALOFT WILL REMAIN OVER
THE MOUNTAINS MONDAY BEHIND THE EXITING TROUGH. MOISTURE BECOMES
SHALLOW DURING THE AFTERNOON HOURS. EXPECT SNOW TO DECREASE IN
COVERAGE AND INTENSITY THROUGH THE DAY MONDAY. WILL KEEP THE WINTER
STORM WARNING AS IS...THOUGH IT WILL LIKELY NEED TO BE ENDED A
LITTLE SOONER.
PATCHY OROGRAPHIC LIGHT SNOW WILL CONTINUE MONDAY NIGHT AND TUESDAY.
BECAUSE OF DECREASING MOISTURE AND A MORE NORTHERLY WIND COMPONENT
EXPECT ANY SNOWFALL TO BE LIGHT. A SHORT WAVE TROUGH EMBEDDED IN THE
NORTHWEST FLOW ALOFT WILL MOVE SOUTH ACROSS THE PLAINS STATES
TUESDAY. THE JET AXIS WILL MOVE OVER EASTERN COLORADO EARLY TUESDAY.
THE NORTHEAST CORNER OF THE STATE WILL BE UNDER THE FRONT LEFT
QUADRANT OF THE JET. WILL ADDED SOME LOW POPS INTO THE FORECAST FOR
THIS. EXPECT THIS SYSTEM TO BRING WINDY CONDITIONS TO THE NORTHEAST
PLAINS. IN ADDITION TO THE WINDS...TEMPERATURES WILL BE COOLER
TUESDAY.
TEMPERATURES REBOUND ON WEDNESDAY WITH MANY LOCATIONS OVER NORTHEAST
COLORADO CLIMBING ABOVE 50 DEGREES. ANOTHER STRONG WAVE WILL DIVE
SOUTH ACROSS THE PLAINS STATES THURSDAY. THIS WILL BRING COOLER
TEMPERATURES AND ANOTHER ROUND OF WINDY CONDITIONS ACROSS THE
NORTHEAST PLAINS.
FLOW ALOFT WILL WEAKEN FRIDAY AND SATURDAY AS THE UPPER LEVEL RIDGE
OVER THE WESTERN STATES STARTS TO SHIFT EASTWARD. THIS WILL BRING
MILD AND DRY CONDITIONS. TEMPERATURES BY SATURDAY SHOULD CLIMB INTO
THE 50S ACROSS NORTHEAST COLORADO.
AVIATION...VFR CONDITIONS OVER THE NEXT 24 HRS. LIGHTER SLY WIND
COMPONENT WAFFLING FM SE-SWLY THIS MORNING. SHOULD SEE WINDS
INCREASE AND BECOME SWLY AFTN 15Z THIS MORNING...THEN PICK UP FM
THE WEST/NORTHWEST 17-18Z FOLLOWING FROPA. GENERAL 15-25 KTS WITH
SOME GUSTS TO 35 KTS FM 20Z-01Z. WINDS WILL DECREASE THIS EVENING
BUT PERSISTENT WSWLY DIRECTION OVERNIGHT. AT KBJC STRONG WINDS
WILL DEVELOP THIS AFTN AND CONTINUE TONIGHT. STRONGEST WIND WILL
BE THIS AFTN AND LATE TONIGHT...AFTER 06Z WITH GUSTS OF 50+ KTS
PSBL AT THAT TIME.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 5 PM MST MONDAY FOR COZ031-033-034.
HIGH WIND WARNING FROM 2 PM THIS AFTERNOON TO 11 AM MST MONDAY
FOR COZ035-036.
WINTER WEATHER ADVISORY UNTIL 8 PM MST THIS EVENING FOR COZ030-
032.
&&
$$
SHORT TERM...ENTREKIN
LONG TERM....MEIER
AVIATION...ENTREKIN
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
309 AM MST SUN JAN 12 2014
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 308 AM MST SUN JAN 12 2014
SURFACE COLD FRONT STRETCHED FROM WRN WY ACROSS NRN UT TO SRN NV AT
09Z. REGIONAL RADARS SHOWED PRECIP GENERALLY CONFINED TO ALONG AND
BEHIND THE FRONT...WITH RAIN REPORTED AT SLC. THE UPPER LOW CENTER
WAS CROSSING THE NRN ROCKIES WITH AN EAST-SOUTHEAST PUSH TO THE
ASSOCIATED TROUGH EXTENDING DOWN TO NRN NV. WHERE GUSTY WINDS
DEVELOP AT THE SURFACE...THE TURBULENT MIXING HAS RESULTED IN TEMPS
EXHIBITING A SPIKE UPWARDS. MEEKER AND CRAIG BOTH TOUCHED 40F
EARLIER IN THE NIGHT WHEN THIS OCCURRED.
PRECIPITATION HAS BE SLOW TO START OVER OUR AREA THOUGH STRONG
LOW-LEVEL WARM ADVECTION LIKELY PUTTING AT LEAST SOME AREAS OF LIGHT
SNOW OVER THE HIGHER ELEVS OF THE ERN UINTAS AND NRN CO MTNS. A FEW
MTN SNOTEL SITES REGISTERING LIGHT AMOUNTS SUPPORT THIS. CLOUDS
BASES HAVE BEEN SLOWLY LOWERING...SO SUSPECT THAT PRECIP WILL BE
RAMPING UP BY 12Z WHEN THE RUC13 MODEL HAS THE FRONT REACHING A
MOAB-CRAIG LINE....AND THEN TO THE SAN JUANS BY MIDDAY. AS THE UPPER
JET ON THE FRONT SIDE OF THE TROUGH MOVES OVERHEAD...THE COMBINATION
OF DYNAMICS AND FRONTAL LIFT WITH DEEP INSTABILITY SHOULD BRING
WIDESPREAD SNOW TO THE MOUNTAINS AND TO MANY NORTHERN AND CENTRAL
VALLEYS THIS MORNING. STRONG WINDS ALOFT WITH GUSTY WINDS AT THE
SURFACE WILL PRODUCE AREAS OF BLOWING SNOW ACROSS THE NORTH AND
CENTRAL AREAS. STRONGEST WINDS SHOULD BE OVER THE FLATTOPS AND
ELKHEAD/PARK/GORE MTNS. SNOW AND BLOWING SNOW WILL MAKE TRAVEL VERY
DIFFICULT OVER RABBIT EARS AND VAIL PASSES THIS AFTERNOON AND
EVENING...AND PROBABLY MONDAY TOO.
AS THE FRONT AND UPPER TROUGH MOVE PAST... FORCING BECOMES MORE
OROGRAPHICALLY DRIVEN AS NORTHWEST FLOW SETS UP THIS AFTERNOON AND
EVENING. PRECIPITABLE WATER AND SPECIFIC HUMIDITY VALUES DROP QUICKLY
BEHIND THE FRONT TODAY...BUT THE NAM/GFS MAINTAIN A MOIST DENDRITIC
SNOW GROWTH LAYER ACROSS THE NRN MTNS WITH A SECOND PUSH OF MOISTURE
TONIGHT THAT SHOULD HELP MAINTAIN SNOW THERE INTO MONDAY.
ASIDE FROM THE BIT SLOWER START TO PRECIPITATION...THE CURRENT
FORECAST GRIDS AND WINTER HIGHLIGHTS LOOK ON TRACK. MADE ONLY MINOR
CHANGES SUCH AS TO EXPAND BLOWING SNOW IN THE GRIDS INTO MORE OF
THE NW CO VALLEYS TODAY
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 308 AM MST SUN JAN 12 2014
NWLY FLOW WILL KEEP SOME SNOW SHOWERS IN THE PICTURE FOR THE NRN
MTNS THOUGH ACCUMULATIONS WILL BE ON THE LIGHT SIDE MONDAY NIGHT
INTO TUESDAY. BOTH THE GFS AND NAM HIGHLIGHT THIS PRECIP THROUGH TUE
AFTN SO KEPT CHCS FOR PRECIP IN FORECAST. AFTER THAT...A LARGE
RIDGE OF HIGH PRESSURE TO THE WEST WILL BUILD IN KEEPING OUR CWA
HIGH AND DRY THROUGH THE REMAINDER OF THE FORECAST PERIOD. SOME
DISCREPANCIES POP UP TOWARDS THE WEEKEND BTWN THE EC AND GFS BUT
LOW CONFIDENCE IN FORECAST AS SOLNS ARE SO FAR OUT.
EXPECT TEMPERATURES TO CLIMB A FEW DEGREES ABOVE NORMAL FOR THIS
TIME OF YEAR FROM TUESDAY ONWARDS EXCEPT FOR THOSE VALLEYS WHERE
INVERSIONS SET UP...THE GRAND VALLEY...TELLURIDE AND DURANGO TO
NAME A FEW.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 308 AM MST SUN JAN 12 2014
CONDITIONS WILL DETERIORATE AS THE DAY PROGRESSES FOR MOUNTAINOUS
TERRAIN. ANTICIPATE MVFR TO IFR CONDITIONS FOR KSBS...KCAG...KHDN
AND SIMILAR CONDITIONS FOR KASE AND KEGE THOUGH ALL TAF SITES MAY
SEE SOME BRIEF SNOW AS A COLD FRONT MOVES ACROSS THE REGION TODAY.
ONCE THE FRONT HAS MOVED THROUGH BY THIS EVENING...SNOWFALL WILL
CONTINUE FOR THE NRN AND CENTRAL MTNS. ALONG WITH SNOW...EXPECT
GUSTY WINDS WITH SOME BLOWING SNOW EXPECTED ALSO DROPPING VISIBILITIES.
STRONGER WINDS CAN BE EXPECTED AT HIGHER ELEVATIONS CAUSING SOME
MECHANICAL TURBULENCE WHILE MTN OBSCURATIONS WILL BE COMMON TODAY
AND TONIGHT.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER WEATHER ADVISORY UNTIL 9 PM MST THIS EVENING COZ008-014.
WINTER STORM WARNING UNTIL MIDNIGHT MST TONIGHT COZ009-012-018.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT MST TONIGHT COZ003-017.
WINTER STORM WARNING UNTIL 5 PM MST MONDAY COZ004-010-013.
WINTER STORM WARNING UNTIL 3 AM MST MONDAY COZ005.
WINTER WEATHER ADVISORY UNTIL 5 PM MST THIS AFTERNOON COZ002.
UT...NONE.
&&
$$
SHORT TERM...JAD
LONG TERM...TGR
AVIATION...TGR
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
931 AM EST SUN JAN 12 2014
.SYNOPSIS...
A LARGE AREA OF LOW PRESSURE OVER EASTERN CANADA WILL MOVE INTO THE
ATLANTIC TODAY. HIGH PRESSURE WILL BUILD ACROSS THE REGION TONIGHT
THROUGH MONDAY...BUT THEN MOVE AWAY FROM THE AREA. LOW PRESSURE WILL
MOVE ACROSS THE GREAT LAKES TUESDAY SENDING A FRONT ACROSS THE AREA
TUESDAY. ANOTHER WAVE OF LOW PRESSURE WILL AFFECT THE AREA TUESDAY
NIGHT FOLLOWED BY A COLD FRONT LATER WEDNESDAY. HIGH PRESSURE WILL
BUILD IN FOR THURSDAY...FOLLOWED BY ANOTHER LOW PRESSURE AREA FOR
EARLY NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
ADJUSTED CLOUD COVER UP A BIT MORE AND FOR A LITTLE LONGER THROUGH
THE MORNING HOURS. LATEST RUC IS SHOWING A LOT OF STUBBORN
MOISTURE AT 925MB HANGING AROUND THROUGH MUCH OF THE DAY BUT DID
NOT GO THAT PESSIMISTIC AS WE SHOULD START TO SEE BETTER BUILDING
HEIGHTS AND MORE SUBSIDENCE TAKING PLACE. SHOULD START TO SEE MORE
BREAKS IN THE STRATOCU DECK BY LATE MORNING WITH MORE DOWNSLOPING
AND THE HIGHER SUNANGLE.
OTHERWISE, BOTH THE GFS AND WRF-NMMB INITIALIZATION LOOKED GOOD
AT 500MB, AT 850MB AND 925MB THEY WERE ADVECTING IN THE COLD AIR
TOO QUICKLY AND THEIR BIAS OF THE CORE OVER THE LOWER LAKES WAS
AROUND 1C TOO COLD.
WITH NO MEASURABLE PCPN TO SPEAK ABOUT, THE HIGHER CONCERN IS ON
TEMPS. WE LEANED TOWARD THE HIGHER STAT GUIDANCE BECAUSE OF THE SAID
BIAS AND ALSO OUR CURRENT RELATIVE WARMTH. ANOTHER WINTER DAY IN
WHICH OUR CALENDAR DAY HIGH LIKELY ALREADY OCCURRED AT 1201 AM. THIS
IS A QUICK SHOT OF "COOLER AIR" AS THE THERMAL TROF PASSES THROUGH
THIS MORNING. IT WILL BE A BRISK DAY AS THERE STILL WILL BE 25 TO 30
KTS OF WIND FORECAST AT 925 MB INTO THIS AFTERNOON. MOST OF IT
SHOULD MIX DOWN EASIER THAN YESTERDAY (NOT COMPLAINING AS THE WINDS
AT 925MB WERE TWICE AS STRONG YESTERDAY). WE HAVE PEAK GUSTS CLOSE
TO 30 MPH IN MOST OF THE AREA. LASTLY ABOUT CLOUDS, THE GFS IS
FORECASTING A LOWER CONVECTIVE TEMP THAN THE WRF-NMMB. BOTH THE
ECMWF AND CAN RGEM LOOK CLOSER TO THE GFS. SO WE DID NOT GO
COMPLETELY SUNNY. STILL PLENTY OF STRATOCU TO OUR WEST. AS IS
TYPICALLY THE CASE, THE CONVECTIVE TEMP GETS EASILY REACHED FAR
NORTH, JUST GETS REACHED ALONG I95 AND NOT AT ALL IN DELMARVA. WE
TRIED TO REFLECT THIS IN THE GRIDS. BECAUSE OF SOME LAKE EFFECT
ECHOES IN WESTERN PA (THE FLOW LOOKS MORE WNW THAN WE EXPECTED
YESTERDAY), WE DID KEEP THE CHANCE OF MORNING FLURRIES IN THE
POCONOS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
A RADIATIONAL COOLING NIGHT IS FORECAST FOR MOST OF TONIGHT. BOUNDARY LAYER
WINDS START WEAK ENOUGH TO PERMIT DECOUPLING IN THE EVENING. THEY DO
INCREASE TOWARD MORNING, WE HAVE MINS OCCURRING SLIGHTLY EARLIER
THAN USUAL. THE WRF-NMMB MORE THAN THE GFS BRINGS CIRRUS NORTH AFTER
MIDNIGHT. EVEN WITH THIS GIVEN MOST OF THE NIGHT SHOULD BE CLEAR, WE
ARE NOT EXPECTING THE CLOUDS TO HAVE AN IMPACT ON THE FINAL MINS.
WE LEANED CLOSER TO THE LOWER STAT GUIDANCE IN NON-URBAN/NON-COASTAL
AREAS FOR MIN TEMPS.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
MONDAY WILL PROBABLY HAVE THE BEST WEATHER OF THE UPCOMING WEEK. IT
IS EXPECTED TO BE DRY AS A RIDGE OF HIGH PRESSURE WILL BE ACROSS THE
AREA. THE AIRMASS IN PLACE IS NOT COLD...SO HIGH TEMPERATURES WILL
BE ABOVE NORMAL. HIGHS SHOULD RANGE FROM THE UPPER 40S/LOW 50S
ACROSS THE NORTH TO THE MID 50S OVER THE DELMARVA.
SEVERAL AREAS OF LOW PRESSURE WILL MOVE TOWARDS THE EAST COAST
TUESDAY AND WEDNESDAY. ONE WILL BE MOVING ACROSS THE SOUTHEAST U.S.
AND THIS SYSTEM WILL BRING MOISTURE TO THE AREA MONDAY NIGHT INTO
TUESDAY. THE TEMPERATURES WILL STILL BE WARM ENOUGH FOR MOSTLY RAIN
ACROSS THE AREA. WE HAVE USED THE WPC POPS AND ADJUSTED THEM TO FIT
THE NEARBY OFFICES...SO POPS ARE MOSTLY IN THE HIGH CHC/LOW LIKELY
RANGE. THE LOW WILL MOVE OFF THE COAST TUESDAY NIGHT WHILE A SECOND
LOW MOVES ACROSS THE GREAT LAKES. THIS SECOND LOW WILL USHER IN
COLDER AIR BEHIND IT FOR THE MIDDLE OF THE WEEK. PCPN WILL MOSTLY BE
RAIN WEDNESDAY...BUT THEN CHANGE TO SNOW WED EVENING BEFORE ENDING.
POPS ARE IN THE CHC RANGE AT THIS TIME. SINCE THE SYSTEM WILL BE
MOVING RATHER QUICKLY...ANY SNOW AMTS WILL BE LIGHT. LOWS WILL DROP
INTO THE 20S WED NIGHT.
THE REST OF THE EXTENDED PERIOD WILL FEATURE DRY WEATHER AND
TEMPERATURES WHICH WILL BE NORMAL OR ABOVE (THU/FRI) AND THEN BELOW
NORMAL FOR SAT. A COLD FRONT WILL CROSS THE AREA FRI NIGHT. THE
LATEST EC MODEL IS SHOWING THE POSSIBILITY FOR SOME PCPN FRI NIGHT
AND SAT...BUT CONFID IN ANY MODEL SOLUTION THAT FAR OUT IS LOW ATTM
AND WE WILL STICK WITH THE DRY FCST OFFERED BY WPC.
&&
.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THE 12Z TAFS ARE VFR THRUT.
THIS MORNING, NORTHWEST WINDS SHOULD INCREASE AND AVERAGE CLOSE TO
15 KTS WITH GUSTS BETWEEN 20 AND 30 KTS BY THE END OF THE MORNING.
THIS WILL CONTINUE INTO THE AFTERNOON. CLOUDS: WE CARRY A VFR
STRATOCU CIG FOR MOST OF OUR TERMINALS THROUGH THE MORNING HOURS
BEFORE SCATTERING THEM OUT. THIS AFTERNOON WE ARE EXPECTING
FEW/SCATTERED CU/SC. MOST COVERAGE AND POSSIBLE VFR CIGS AT KABE
AND KRDG.
SUNDAY EVENING AND INTO THE OVERNIGHT. WINDS WILL DECREASE
RAPIDLY AND ANY LEFTOVER CU OR SC CLOUDS WILL DISSIPATE. BY THE
MIDDLE/LATE EVENING MOST TERMINALS WILL HAVE LIGHT AND VARIABLE
WINDS. EXCEPTION IS KPHL WHERE WE BACKED THE (STILL LIGHTER) WINDS
TO THE SOUTHWEST.
ON MONDAY MORNING WE START KPHL WITH A SOUTHSOUTHWEST WIND AND THE
ARRIVAL OF SOME CIRRUS.
OUTLOOK...
MONDAY...VFR EXPECTED.
MON NIGHT THRU WED...MOSTLY MVFR WITH BRIEF IFR POSSIBLE IN
SHOWERS.
WED NIGHT/THU...MOSTLY VFR. SNOW SHOWERS POSSIBLE NORTH.
&&
.MARINE...
WHILE THERE IS COLD AIR ADVECTION TODAY, THE AIR MASS IS NOT A
PARTICULARLY COLD ONE. THIS IS INDICATED IN THE FORECAST SOUNDINGS
THAT EVEN OVER THE OCEAN ARE NOT MIXING COMPLETELY AOB 900MB. WE
WILL CONTINUE WITH THE SCA FOR ALL OF OUR WATERS FOR TODAY. AS THE
AFTERNOON PROGRESSES CONFIDENCE ABOUT SMALL CRAFT ADVISORY CRITERIA
WINDS CONTINUING ON DELAWARE BAY LESSEN.
FOR TONIGHT, WE WILL START DELAWARE BAY BELOW SMALL CRAFT ADVISORY
CRITERIA. THE EVENING SMALL CRAFT ADVISORY FOR THE OCEAN IS MORE FOR
THE SEAS THAN WINDS AS WAVE WATCH GUIDANCE HAS BEEN CONSISTENT IN
NEEDING THIS MUCH TIME FOR THE SERLY SWELLS TO SUBSIDE.
OUTLOOK...
MON/TUE...WINDS SEAS BUILDING WITH SCA FLAGS ON THE OCEAN.
TUE NGT/WED NGT...SUB-SCA CONDITIONS. SHOWERS/FOG POSSIBLE.
THU...SCA FLAGS POSSIBLE FOR THE OCEAN.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR
ANZ450>455.
SMALL CRAFT ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR ANZ430-
431.
&&
$$
SYNOPSIS...O`HARA
NEAR TERM...GIGI/HEAVENER
SHORT TERM...GIGI
LONG TERM...O`HARA
AVIATION...GIGI/O`HARA
MARINE...GIGI/O`HARA
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
1000 AM EST SUN JAN 12 2014
.UPDATE...
15Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS THE SHARP UPPER LEVEL
TROUGH RESPONSIBLE FOR SATURDAYS STORMS NOW QUICKLY EXITING EAST
INTO THE WESTERN ATLANTIC. REBOUNDING HEIGHTS AND STRONG
SUBSIDENCE IN THE WAKE OF THIS FEATURE HAVE EXPANDED OVER THE
FLORIDA PENINSULA. AN IMPRESSIVE TONGUE OF DRY MID/UPPER LEVEL AIR
IS SEEN IN WATER VAPOR OVER NORTHERN FLORIDA WITH MOISTURE GRADUALLY
INCREASING SOUTHWARD AS OVERALL SYNOPTIC SUBSIDENCE WEAKENS. 12/12Z
KTBW SOUNDING PROFILE SHOWS THAT THIS DRY AIR EXTENDS THROUGH MUCH
OF THE TROPOSPHERE...WITH IMPRESSIVE DEWPOINT DEPRESSIONS
OBSERVED DOWN TO ALMOST 900MB. THE SYNOPTIC SUBSIDENCE CAN ALSO
BE SEEN STRONGLY IN THE COLUMN PW WHICH DROPPED FROM A HIGH 1.77"
LAST EVENING TO A LOW 0.36" BY THIS MORNING.
LOOKING UPSTREAM IN THE UPPER LEVELS WE SEE WEAK RIDGING EXPANDING
EASTWARD FROM THE CENTRAL CONUS. THIS RIDGING WILL PROVIDE FAIR AND
SEASONABLE WEATHER FOR THE REGION THROUGH MUCH OF MONDAY.
HOWEVER...FURTHER UPSTREAM WE SEE OUR NEXT WEATHER MAKER IN THE FORM
OF A DIGGING TROUGH THROUGH THE INTER-MOUNTAIN WEST. THIS ENERGY
WILL BE QUITE PROGRESSIVE THE NEXT DAY OR TWO AS IT CONTINUES TO
AMPLIFY. THE LARGE SCALE FORCING AND INCREASED RAIN CHANCES
ASSOCIATED WITH THIS NEXT SYSTEM ARE SCHEDULED TO ARRIVE ACROSS
NORTHERN AND CENTRAL FLORIDA BY MONDAY NIGHT. SO...IT WILL BE A
QUICK BOUT OF FAIR WEATHER BETWEEN STORMS...BUT AT LEAST WE MANAGED
TO SALVAGE A SUNNY AND DRY WEEKEND DAY.
AT THE SURFACE...1020+MB HIGH PRESSURE WILL BECOME CENTERED OVER
NORTHERN FLORIDA BY THIS AFTERNOON...AND THEN SHIFT OFF THE
SOUTHEAST CONUS COAST OVERNIGHT.
WITH ALL THE DRY AIR AND SUBSIDENCE ALOFT...OUR SKIES ARE MOSTLY
CLEAR LATE THIS MORNING AND EXPECT THIS TO CONTINUE THROUGH THE
REMAINDER OF THE DAY. A BIT COOLER AIRMASS HAS ARRIVED COMPARED TO
THE TEMPS AND DEWPOINTS ON SATURDAY...HOWEVER AFTERNOON HIGHS IN THE
MID/UPPER 60S NORTH AND MIDDLE 70S SOUTH ARE STILL QUITE SEASONABLE
FOR MID JANUARY.
EXPECTING A COOLER NIGHT WITH THE DRY AIR IN PLACE AND THE CLOSE
PROXIMITY OF THE SURFACE RIDGE. HOWEVER...THIS AIRMASS IS NOTHING
LIKE THE ONE FROM LAST WEEK...AND WE DO NOT ANTICIPATE ANY
SUB-FREEZING TEMPS TO OCCUR. A FEW VERY ISOLATED PATCHES OF FROST
ARE NOT OUT OF THE QUESTION FOR LEVY COUNTY AT THE NORMALLY COLDER
AND MORE EFFICIENT RADIATIONAL COOLING SITES...BUT EVEN THIS MAY BE
A STRETCH. ELSEWHERE LOW TEMPS BY SUNRISE ON MONDAY WILL RANGE FROM
THE 40S NORTH OF THE I-4 CORRIDOR TO THE UPPER 40S AND LOWER 50S
ACROSS CENTRAL FLORIDA AND THE LOWER/MID 50S DOWN TOWARD FORT MYERS.
MAY SEE SOME INCREASE IN THIN HIGH CIRRUS DURING THE OVERNIGHT...BUT
WILL CONTINUE TO CALL IT MOSTLY CLEAR.
MONDAY...UPPER TROUGH AND ASSOCIATED SYNOPTIC FORCING WILL BEGIN TO
SPREAD EASTWARD ALONG THE NORTHERN GULF COAST. MID/UPPER LEVEL PV
ANOMALY DIGGING TOWARD THE CENTRAL GULF COAST AND AN ASSOCIATED
STRONG JET STREAK ALIGNED ALONG AND EAST OF THE MS VALLEY SHOULD
INITIATE WEAK CYCLOGENESIS OVER THE NORTH-CENTRAL GULF OF MEXICO
BAROCLINIC ZONE DURING THE DAY...WITH AN ATTENDANT WARM FRONT
DEVELOPING EASTWARD TO NORTH FLORIDA BY EVENING. MOST OF THE
GLOBAL GUIDANCE DOES NOT SHOW ANY QPF OVER THE NORTHERN NATURE COAST
BEFORE MONDAY NIGHT...HOWEVER NWP GUIDANCE IS ALMOST ALWAYS BIASED
ON THE SLOW SIDE TOWARD COLUMN MOISTENING AND PRECIP INITIATION
WITHIN ISENTROPIC UPGLIDE REGIMES. WITH THIS IN MIND FEEL AT LEAST A
SMALL RAIN CHANCE IS WARRANTED UP TOWARD CITRUS/LEVY COUNTY BY THE
SECOND HALF OF MONDAY AFTERNOON. THE BEST CHANCES FOR RAIN OVER
NORTHERN AND CENTRAL FLORIDA WILL THEN ARRIVE MONDAY NIGHT AS THE
HEIGHT FALLS/DCVA AND RRQ JET DYNAMICS BECOME MOST COINCIDENT OVER
THE REGION.
WHILE STILL SEVERAL DAYS AWAY...GLOBAL GUIDANCE MEMBERS ARE IN
AGREEMENT OF A BRIEF...BUT MUCH STRONGER BLAST OF COLD AIR ARRIVING
INTO THE PENINSULA DURING WEDNESDAY. POTENTIAL FOR FREEZING
TEMPERATURES IS CERTAINLY THERE FOR BOTH WEDNESDAY NIGHT AND
THURSDAY NIGHT...ESPECIALLY OVER THE NATURE COAST. LOW WIND CHILLS
ARE LIKELY FOR ALL OF THE REGION WEDNESDAY NIGHT/EARLY THURSDAY
MORNING. WE WILL CONTINUE TO MONITOR THIS POTENTIAL FREEZE EVENT FOR
LATER IN THE WEEK.
&&
.AVIATION...
12/12Z-13/12Z...VFR PREVAIL WITH FEW-SCT CLOUDS. NORTHERLY WINDS
GRADUALLY BECOME NORTHEASTERLY.
&&
.MARINE...
NORTHERLY FLOW IN THE WAKE OF A COLD FRONT CONTINUES TO RESULT IN
CAUTIONARY LEVEL WINDS AND SEAS OVER THE OFFSHORE WATERS THIS
MORNING. THESE CONDITIONS WILL GRADUALLY SUBSIDE INTO THE AFTERNOON
HOURS WITH ALL HEADLINES DROPPED BY THIS EVENING. WINDS WILL SHIFT
EAST AND THEN SOUTHEAST TONIGHT INTO MONDAY AS HIGH PRESSURE PASSES
EAST OF THE REGION. THE NEXT COLD FRONT IS FORECAST TO PASS THROUGH
THE EASTERN GULF MONDAY NIGHT OR EARLY TUESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 71 52 73 66 / 0 10 10 70
FMY 76 55 79 67 / 0 10 10 40
GIF 73 50 77 64 / 0 10 10 60
SRQ 71 53 75 66 / 0 0 10 60
BKV 70 43 75 61 / 0 10 10 70
SPG 70 55 74 67 / 0 10 10 70
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
UPDATE...MROCZKA
AVIATION...RUDE
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
854 AM CST SUN JAN 12 2014
.UPDATE...
ISSUED AT 854 AM CST SUN JAN 12 2014
HAVE HAD TO ISSUE A RATHER SHORT FUSE FREEZING RAIN ADVISORY IN
CENTRAL MINNESOTA FOR AREA OF LIGHT RAIN MOVING THROUGH. ALTHOUGH
MOST REPORTING LOCATIONS HAVE ONLY REPORTED PRECIP FOR 1 TO 2
HOURS...WITH TEMPERATURES RANGING FROM 28 TO 32...WE HAVE SEEN A
SIGNIFICANT AMOUNT OF TRAVEL CONCERNS DEVELOP ACROSS CENTRAL MN
WITH ICING CONDITIONS. MNDOT TRAVEL MAP HAS CATEGORIZED ROADS
ACROSS CENTRAL MN AS HAZARDOUS WITH TRAVEL NOT ADVISED...WHICH WAS
A BIG REASON FOR ISSUING THIS ADVISORY.
HOPWRF AND HRRR SHOW THIS BAND OF PRECIP LIFTING NE TOWARD
DLH...SO SEE NO NEED TO EXPAND THE FREEZING RAIN ADVISORY EAST
INTO WEST CENTRAL WI...AS ALL SHORT TERM MODELS INDICATE THAT THEY
WILL SEE NO PRECIPITATION OVER THERE. THE WEST EDGE OF THE ADVISORY
WAS SET BASED ON WHERE PRECIP IS CURRENTLY FALLING...COULD HAVE
ADDED BENSON UP THROUGH ALEXANDRIA TO THE ADVISORY...BUT RAIN
THERE IS ALREADY DONE...WITH TEMPERATURES ALREADY STARTING TO
SNEAK ABOVE FREEZING WEST OF THE ADVY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 228 AM CST SUN JAN 12 2014
LATEST WATER VAPOR IMAGERY SHOWS HIGH CLOUDS AND MOISTURE MOVING
EAST WITH THE UPPER RIDGE AXIS ACROSS THE REGION AT THE CURRENT
TIME. THIS HAS HELPED TO INCREASE THE MID-HIGH CLOUDS OVER OUR
AREA... WITH LOWER CLOUDS STILL TO THE WEST WHERE SOME PCPN IS
APPARENT ON RADAR AND SURFACE OBS. THAT PCPN IS PRIMARILY BEING
FORCED BY SOME DECENT ISENTROPIC LIFT AHEAD OF THE UPPER TROUGH...
WHICH IS LAGGING BACK WELL TO THE WEST. THE CURRENT AREA OF PCPN
WILL TRY TO HOLD TOGETHER AS IT MOVES EAST TODAY... BUT IT STILL
APPEARS THAT THE BEST CHANCE FOR PCPN WILL BE OVER THE FAR NORTHERN
PART OF THE FORECAST AREA... WHERE DEEPER MOISTURE LOOKS TO BE
PRESENT THROUGH THE DAY. HOWEVER... EVEN THERE IT DOESN/T APPEAR AS
THOUGH PCPN AMOUNTS WILL BE SUBSTANTIAL... AND IT/S POSSIBLE SOME
LOCATIONS WON/T MEASURE AT ALL... SO STILL KEPT POPS AS CHANCES
RATHER THAN LIKELY. PCPN-TYPE WITH WHATEVER OCCURS WILL BE TRICKY...
SINCE TEMPERATURES ARE ALREADY CLIMBING ABOVE FREEZING ALOFT... AS
WAS EVIDENT IN THE UPSTREAM SOUNDINGS AT 00Z WHICH SHOWED THE WARM
NOSE AROUND 900-850MB. WITH CONTINUED WARM ADVECTION THROUGH THE DAY
THAT SITUATION SHOULDN/T IMPROVE. SO... WOULD EXPECT PARTIAL TO
COMPLETE MELTING OF PCPN ALOFT... BUT SURFACE TEMPERATURES WILL TAKE
A BIT OF TIME BEFORE THEY CLIMB ABOVE FREEZING TODAY... SO THERE
STILL APPEARS TO BE A CHANCE FOR SOME SLEET AND FREEZING
RAIN/DRIZZLE THIS MORNING WITH ANY PCPN WHICH MOVES ACROSS THE
NORTHERN PORTION OF THE AREA. BUT... AS MENTIONED... WHATEVER OCCURS
SHOULD BE LIGHT. THE UPPER TROUGH CURRENTLY EVIDENT ON WATER VAPOR
OVER THE WESTERN US WILL CONTINUE TO MOVE EAST TONIGHT... AND LOOKS
TO MOVE INTO THE WESTERN PART OF OUR AREA AFTER 06Z. WE/LL SEE AN
INITIAL COLD FRONT MOVE THROUGH THIS EVENING... WHICH WON/T DO TOO
MUCH TO COOL THINGS OFF... BUT WILL SERVE TO SHIFT WINDS AROUND TO
THE WEST AND NORTHWEST... FURTHER LIMITING THE CHANCE FOR ANY
MOISTURE RETURN AHEAD OF THE UPPER TROUGH AND MORE MEANINGFUL COLD
FRONT WHICH MOVES THROUGH OVERNIGHT. THERE COULD BE SOME LIGHT PCPN
LATE TONIGHT AS THE UPPER TROUGH AND SECONDARY FRONT MOVE THROUGH...
BUT AT THIS POINT IT DOESN/T LOOK TO BE ANY MORE THAN FLURRIES... SO
DIDN/T INCLUDE ANYTHING IN THE FORECAST. THE MAIN THING WILL BE THE
PUSH OF COLDER AIR THE SYSTEM BRINGS.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 228 AM CST SUN JAN 12 2014
THE EXTENDED PERIOD WILL BE MARKED WITH A TWO STORM SYSTEMS WHICH
WILL AFFECT THE UPPER MIDWEST EARLY TUESDAY...AND THEN THURSDAY.
BOTH OF THESE SYSTEMS WILL HAVE A STRONG INFLUENCE OF THICKNESS
VALUES RISING ENOUGH TO CONSIDER A MIXTURE OF SLEET/FREEZING
RAIN/RAIN IN THE FAR SW CWA. EVEN IF WE DO GET PRECIPITATION IN
THIS AREA...THE INCREASING THICKNESS VALUES AND ASSOCIATED 85/92H
TEMPS RISING TO LIMIT THE BEST FORMATION OF ICE CRYSTALS /MORE
FREEZING RAIN/DRIZZLE AND SUPERCOOLED LIQUID WATER DROPLETS/...WILL
LIMIT SNOWFALL AMTS. BEST CHC OF RECEIVING MEASURABLE
PRECIPITATION IN SW/SC MN WILL OCCUR WITH EARLY TUESDAY/S SYSTEM.
TAKING A CROSS SECTION ALONG A KOMA TO KDLH LINE INDICATES THAT
BOTH THE GFS/EC HAVE SIMILAR SCENARIO/S OF A BRIEF PERIOD OF
STRONG LIFT ARND 6Z TUESDAY IN THE DENDRITIC SNOW ZONE. FORCING IS
VERY LIMITED 6 HRS BEFORE AND AFTER THIS TIME FRAME. AS DISCUSS
WITH THICKNESS VALUES AND THE INFLUENCE OF HIGHER 92H/85H
TEMPS...SNOWFALL AMTS MAY BE LIGHTER THAN EXPECTED. EVEN WITH A 13
TO 15-1 SNOWFALL RATIO BETWEEN 00-12Z TUESDAY...SNOWFALL AMTS WILL
RANGE FROM 1" TO 2.5". ALTHOUGH MODELS HAVE BEEN MORE CONSISTENT
IN TERMS OF A SFC LOW DEVELOPING ACROSS THE DAKOTAS...AND MOVING
THIS SYSTEM RAPIDLY SE ACROSS THE MIDWEST TUESDAY AFTN...PLACEMENT
OF THE SFC LOW WILL BE CRITICAL IN TERMS OF WHERE THE HEAVIER SNOW
BANDS DEVELOP EARLY TUESDAY. BASED ON CURRENT MODELS...THE BEST
PLACEMENT AND ASSOCIATED QPF FIELD HAS A BAND OF 1.5 TO 2.5" OF
SNOWFALL FROM LONG PRAIRIE...SE TO THE NORTHERN SUBURBS OF THE
TWIN CITIES...TO RIVER FALLS WI. ANY DEVIATION OF THIS SFC
LOW...OR STRONGER INFLUX OF WARMER AIR FROM THE SW...WILL LIMIT
SNOWFALL AMTS.
THURSDAY SYSTEM LOOKS TO BE MAINLY IN THE FORM OF SNOW...BUT DUE
TO THE FAST NATURE OF THE SYSTEM AND LIMITED DEEP MOISTURE AND
LIFT...AMTS WILL BE LIGHT AND FOCUSED NE OF MPX CWA. THE MAJOR
DIFFERENCES BETWEEN TUESDAY/S AND THURSDAY/S SYSTEM IS THE
PRESSURE GRADIENT AND ASSOCIATED STRONG SFC WIND FIELD. BASED ON
THE SFC WINDS AND GUST POTENTIAL...AND IF ANY SNOW CAN BE PICK UP
FROM THE GROUND...BLIZZARD LIKE CONDS MAY DEVELOP...ESPECIALLY IN
THE TYPICAL AREAS OF WC/SW/SC MN THU/THU NIGHT. HAVE INTRODUCED
BLOWING SNOW DURING THIS TIME FRAME...BUT IF CURRENT MODEL TRENDS
HAVE THE CONTINUED SFC PRESSURE GRADIENT FIELD THE SAME...A
BLIZZARD WATCH OR SOME OTHER HIGHLIGHTED WX EVENT IS POSSIBLE.
BEHIND THIS SYSTEM...ANOTHER ARCTIC OUTBREAK WILL OCCUR...BUT NOT
AS COLD AS THE FIRST WEEK OF JANUARY. 92H/85H TEMPS ARE 10 TO 15
DEGREES WARMER THAN THE ARCTIC CORE FROM EARLIER THIS MONTH.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 511 AM CST SUN JAN 12 2014
ALTHOUGH THERE WILL BE PLENTY OF CLOUD COVER THROUGH THE FORECAST
PERIOD... NEARLY ALL OF IT LOOKS TO BE VFR... WITH MOST OF THAT
AOA 10K FT AGL. WARM ADVECTION WILL BE FAIRLY STRONG OVER THE AREA
TODAY... WHICH IS HELPING PRODUCE WIDESPREAD MID-HIGH CLOUDS.
THERE HAS BEEN SOME VERY LIGHT PCPN OVER THE DAKOTAS OVERNIGHT...
BUT IT HAS BEEN DISSIPATING WHILE MOVING EAST INTO DRIER AIR... AS
WAS SUGGESTED BY THE HOPWRF... HRRR... AND EVEN THE COARSER
RESOLUTION GUIDANCE TO SOME EXTENT. THERE IS A SLIGHT CHANCE A BIT
OF THIS LIGHT PCPN COULD IMPACT THE NORTHERN SITES THIS MORNING...
BUT THE PROBABILITY IS TOO LOW TO INCLUDE IN THE TAFS. WE WILL SEE
AN UPPER TROUGH MOVE TOWARD THE AREA TONIGHT... WHICH WILL PUSH A
COLD FRONTAL BOUNDARY ACROSS THE REGION. THERE IS A CHANCE FOR
SOME MVFR CEILINGS BEHIND THE COLD FRONT... SO INCLUDED SOME
POTENTIAL FOR THAT TOWARD THE TAIL END OF THE TAFS. SOME LIGHT
SNOW/FLURRIES COULD ACCOMPANY THE POST FRONTAL COLD ADVECTION AND
STEEPENING LAPSE RATES... BUT AT THIS POINT IT DOESN/T LOOK TO
WARRANT ANY SORT OF VISIBILITY RESTRICTION.
KMSP...TAF REFLECTS EXPECTATIONS WITH GENERALLY HIGH CONFIDENCE.
ONLY CONCERN WOULD BE POTENTIAL FOR SOME MVFR CEILINGS VERY LATE
TONIGHT OR MONDAY MORNING... BUT PLAYED THINGS SOMEWHAT OPTIMISTIC
FOR NOW.
/OUTLOOK FOR KMSP/
MONDAY AFTERNOON...MVFR CEILINGS POSSIBLE. NORTHWEST WIND 10 TO 15 KT.
MONDAY NIGHT...MVFR CEILINGS AND VISIBILITIES EXPECTED WITH
SNOW... IFR CONDITIONS POSSIBLE. SOUTHWEST WIND 10 TO 20 KT
SHIFTING NORTHWEST.
TUESDAY...MVFR CEILINGS EXPECTED... MVFR VISIBILITIES POSSIBLE
WITH A CHANCE OF SNOW. NORTHWEST WIND 10 TO 20 KT.
TUESDAY NIGHT...MVFR CEILINGS POSSIBLE. NORTHWEST WIND 10 TO 15 KT.
WEDNESDAY...VFR. NORTHWEST WIND 5 TO 10 KT BECOMING SOUTHWEST 10
TO 20 KT.
WEDNESDAY NIGHT...MVFR CEILINGS POSSIBLE LATE. SOUTHWEST WIND 15
TO 25 KT.
THURSDAY...MVFR CEILINGS EXPECTED... MVFR VISIBILITIES POSSIBLE
WITH A CHANCE OF SNOW. WEST WIND 15 TO 25 KT SHIFTING NORTHWEST
WITH GUSTS TO 35 KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...FREEZING RAIN ADVISORY UNTIL NOON CST TODAY FOR MNZ042>045-049-
050.
WI...NONE.
&&
$$
UPDATE...MPG
SHORT TERM...
LONG TERM...JLT
AVIATION...
AREA FORECAST DISCUSSION
NWS DULUTH MN
617 AM CST SUN JAN 12 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 343 AM CST SUN JAN 12 2014
THIS WAS A CHALLENGING SHORT TERM FORECAST. THE MAIN FOCUS IS ON
THE POTENTIAL FOR FREEZING RAIN AND A WINTRY MIXTURE OF PCPN THIS
MORNING WITH A WARM FRONT IN THE NORTHERN PLAINS EARLY THIS
MORNING THAT WILL MOVE THROUGH THE NORTHLAND TODAY. THIS WARM
FRONT WILL BE ASSOCIATED WITH A LOW PRESSURE SYSTEM MOVING EAST
ACROSS SOUTH CENTRAL CANADA. THE MODEL SOUNDINGS CONTINUE TO
INDICATE A SHORT PERIOD WHERE SNOW ALOFT WILL FALL INTO A
RELATIVELY WARM LAYER ABOVE FREEZING (AROUND 1 TO 4 DEGREES
CELSIUS)...RESULTING IN FREEZING RAIN AND/OR SLEET AS IT FALLS TO
THE COLD SURFACE...WHICH IS BELOW FREEZING THIS MORNING.
THE CHALLENGING PART THOUGH IS THAT THERE ARE STILL SIGNIFICANT
DIFFERENCES BETWEEN THE MODELS AS TO THE TRACK AND PCPN AMOUNTS
TODAY. I WAS HOPING FOR BETTER MODEL AGREEMENT BY NOW COMPARED TO
MY PREVIOUS SHIFT. THE GFS/GEM/ECMWF/RAP13/HRRR PRIMARILY BRING
THE PCPN THROUGH NE MINNESOTA. ON THE OTHER HAND...THE NAM/WRF/GEM
REGIONAL WERE PRIMARILY BRINGING THE PCPN THROUGH THE INTERSTATE
35 CORRIDOR AND NW WISCONSIN. THE GFS IS MUCH MORE AGGRESSIVE WITH
THE PCPN THAN MOST OF THE OTHER MODELS...AND THE 06Z NAM12 CAME IN
WITH NO PCPN. THIS IS QUITE THE RANGE OF DIFFERENCES. IT APPEARS
THE RAP13 AND HRRR MIGHT BE DOING FAIRLY WELL WITH THE CURRENT
PCPN IN THE NORTHERN PLAINS AT THIS POINT...SO I LEANING ON NE
MINNESOTA BEING THE MOST AFFECTED. HOWEVER...I EXPANDED THE
FREEZING RAIN ACCUMULATION AND WINTER WEATHER ADVISORY TO MUCH OF
NW WISCONSIN SINCE THIS AREA COULD EASILY GET A LIGHT COATING OF
ICE TO MAKE FOR DIFFICULT TRAVEL CONDITIONS.
I EXPECT MUCH OF NE MINNESOTA AND NW WISCONSIN TO GET A LIGHT
COATING OF ICE...AROUND A COUPLE HUNDREDTHS OF AN INCH...THIS
MORNING. SOME ISOLATED LOCATIONS COULD GET UP TO AROUND 5
HUNDREDTHS OF AN INCH DEPENDING ON ANY MORE INTENSE SHOWER BANDS
THAT SET UP. THIS WILL LIKELY CAUSE DIFFICULT TRAVEL CONDITIONS
THIS MORNING UNTIL CONDITIONS BEGIN TO IMPROVE THIS AFTERNOON WITH
THE WARMING TEMPERATURES AND AS THE PCPN BEGINS TO EXIT THE
NORTHLAND.
THE MODEL AND MOS GUIDANCE IS IN PRETTY GOOD AGREEMENT WITH HIGH
TEMPERATURES TODAY WITH WIDESPREAD HIGHS IN THE MID 30S. THE
ARROWHEAD WILL MORE LIKELY REACH THE LOW 30S...WHILE THE BRAINERD
LAKES AREA MORE IN THE UPPER 30S. THERE WILL LIKELY BE SOME
PARTIAL CLEARING THIS AFTERNOON IN THE WAKE OF THE WARM FRONT.
TONIGHT...THE CANADIAN LOW PRESSURE WILL MOVE INTO CENTRAL
ONTARIO...AND ITS COLD FRONT WILL MOVE THROUGH THE NORTHLAND. THIS
WILL BRING COLDER TEMPERATURES WITH LOWS DIPPING DOWN TO THE TEENS
AND SINGLE DIGITS ACROSS NE MINNESOTA. THERE COULD BE LIGHT SNOW
WITH LITTLE TO NO ACCUMULATION ACROSS MUCH OF NE MINNESOTA.
MONDAY...HIGH TEMPERATURES WILL BE SIGNIFICANTLY COLDER THAN TODAY
WITH HIGHS IN THE TEENS AND LOW 20S. THERE MIGHT BE LINGERING
LIGHT SNOW IN THE MORNING...AND THEN A WEAK RIDGE OF HIGH PRESSURE
IN THE NORTHERN PLAINS WILL SHIFT INTO THE NORTHLAND DURING THE
AFTERNOON. THIS COULD BRING SOME PARTIAL CLEARING DURING THE
AFTERNOON...BUT I LEANED ON THE CLOUDIER SIDE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 343 AM CST SUN JAN 12 2014
A SERIES OF DISTURBANCES WILL IMPACT THE NORTHLAND THROUGH THE
EXTENDED PERIOD.
A CLIPPER WILL MOVE SOUTHEAST THROUGH THE AREA MONDAY NIGHT INTO
TUESDAY MORNING BRINGING THE POTENTIAL FOR A COUPLE INCHES OF SNOW
TO ABOUT THE SOUTHERN HALF/THIRD OF THE NORTHLAND. THE MODELS ARE
IN BETTER AGREEMENT TONIGHT THAN 24 HOURS AGO...BUT DIFFERENCES
REMAIN. THE ECMWF/GFS ARE FURTHER NORTH WITH THE TRACK OF THE LOW
AND WITH THE PRECIP...BUT THE LATEST NAM HAS TRENDED A BIT FURTHER
SOUTH. WE RAISED POPS TO LIKELY OVER OUR FAR SOUTHERN
ZONES...WHERE THE BEST CHANCE FOR 1 TO 2 INCHES OF SNOW EXISTS.
SOME HIGHER SNOWFALL AMOUNTS WILL ALSO BE POSSIBLE IN THE SNOWBELT
OF ASHLAND/IRON COUNTIES MONDAY NIGHT INTO TUESDAY DUE TO COLDER
AIR MOVING OVER THE LAKE ON NORTHWEST LOW LEVEL FLOW.
MOST AREAS WILL BE DRY TUESDAY AFTERNOON INTO TUESDAY NIGHT AS A
RIDGE MOVES OVER THE REGION. LAKE EFFECT SNOW WILL CONTINUE TO
BE POSSIBLE OVER PORTIONS OF THE SNOWBELT OF ASHLAND/IRON
COUNTIES.
A STRONGER SYSTEM WILL START TO IMPACT THE NORTHLAND WEDNESDAY. A
SURFACE LOW WILL TRACK FROM MANITOBA WEDNESDAY EVENING SOUTHEAST
TOWARD EASTERN LAKE SUPERIOR/NORTHERN MICHIGAN BY THURSDAY
EVENING. A STRONG AREA OF WAA WILL OCCUR AHEAD OF THE LOW
WEDNESDAY...BRINGING A CHANCE FOR PRECIPITATION TO MUCH OF THE
NORTHLAND BY WEDNESDAY AFTERNOON OR WEDNESDAY NIGHT. WE RAISED
POPS WEDNESDAY INTO WEDNESDAY NIGHT FOR MOST AREAS...AS A PERIOD
OF PRECIPITATION IS LOOKING MORE LIKELY. AT THIS TIME...WE HAVE
HIGHEST POPS OVER NORTHERN MINNESOTA. THE SYSTEM DOES NOT LOOK
QUITE AS WARM AS EARLIER MODEL RUNS...BUT WE DID KEEP A MENTION OF
FREEZING RAIN OVER PORTIONS OF OUR SOUTHERN AREA WEDNESDAY
AFTERNOON. LIGHT TO MODERATE SNOW ACCUMULATIONS WILL BE POSSIBLE
FROM WEDNESDAY AFTERNOON INTO THURSDAY. A PERIOD OF WINDY
CONDITIONS WILL ACCOMPANY A COLD FRONTAL PASSAGE WEDNESDAY NIGHT
INTO THURSDAY. WE HAVE HIGH TEMPS THURSDAY FROM 20 ALONG THE
INTERNATIONAL BORDER TO THE MID TWENTIES ACROSS THE SOUTH. THESE
WILL LIKELY FALL THROUGH THE DAY AS STRONG COLD AIR ADVECTION
OCCURS.
NORTHERLY WINDS THURSDAY INTO FRIDAY WILL COMBINE WITH THE MUCH
COLDER AIR TO PRODUCE A PERIOD OF LAKE EFFECT SNOW SHOWERS ALONG
THE SOUTH SHORE...ESPECIALLY ASHLAND/IRON COUNTIES. THE POTENTIAL
FOR SIGNIFICANT SNOWFALL EXISTS THURSDAY INTO FRIDAY.
MOST AREAS LOOK TO BE DRY FRIDAY INTO THE WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 616 AM CST SUN JAN 12 2014
MAINLY VFR CONDITIONS COVERED THE NORTHLAND EARLY THIS
MORNING...WITH IFR CEILINGS OVER THE ARROWHEAD DOWN INTO THE TWIN
PORTS...AND AROUND KPBH TO KD25. PRECIP COVERAGE IS LIMITED SO FAR
THIS MORNING...CLOSER TO WHAT THE NAM WAS DEPICTING. WE HAVE A
TEMPO GROUP FOR MOST TAF SITES FOR SOME FZRA/PL THIS MORNING. THE
LATEST RAP SUGGESTS MVFR OR IFR CEILINGS WILL REDEVELOP THROUGH THE
DAY TODAY...BUT CONFIDENCE IS LOW ON WHETHER OR NOT THAT WILL
MATERIALIZE. A COLD FRONT WILL MOVE THROUGH THE NORTHLAND TONIGHT
CAUSING WINDS TO TURN W TO NW. A BETTER CHANCE FOR MVFR CEILINGS
WILL OCCUR LATER TONIGHT WITH STRONGER CAA BEHIND THE FRONT. SOME
LIGHT SNOW OR FLURRIES MAY ALSO OCCUR TONIGHT...MAINLY AFFECTING
KHIB/KINL.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 34 16 19 6 / 40 10 10 30
INL 36 7 11 -4 / 40 30 20 10
BRD 38 15 18 10 / 50 10 10 70
HYR 37 21 23 8 / 40 10 20 70
ASX 36 21 23 8 / 40 10 10 50
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR MNZ010-011-018-
019-025-026-033>038.
WINTER WEATHER ADVISORY UNTIL 2 PM CST THIS AFTERNOON FOR MNZ012-
020-021.
WI...WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR WIZ001-006.
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR WIZ002-003-007-
008.
LS...NONE.
&&
$$
SHORT TERM...GROCHOCINSKI
LONG TERM...MELDE
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS NORMAN OK
546 AM CST SUN JAN 12 2014
.AVIATION...
12/12Z TAFS...VFR CONDITIONS WILL PREVAIL. LLWS WILL BE SEEN FIRST
3 OR 4 HOURS ACROSS ALL BUT NORTHWEST OKLAHOMA TERMINALS. STRONG
SOUTHWEST WINDS WILL OCCUR AHEAD OF COLD FRONT. FROPA EXPECTED
NORTHWEST OKLAHOMA TERMINALS AROUND 22Z WITH SOUTHWARD PROGRESSION
CLEARING ALL TERMINALS BY 13/04Z.
&&
.PREV DISCUSSION... /ISSUED 422 AM CST SUN JAN 12 2014/
DISCUSSION...
VERY WARM...DRY...AND WINDY CONDITIONS ACROSS THE REGION TODAY. WE
WENT WITH THE RAP MODEL FOR SHORT-TERM FORECAST SOLUTION WHICH
SPREADS RED FLAG WILDFIRE CONDITIONS ACROSS A LARGE PART OF
WESTERN OKLAHOMA AND WESTERN NORTH TEXAS. THIS SOLUTION IS MUCH
DRIER THAN OTHER GUIDANCE AND WILL LIKELY BE CLOSER TO VERIFYING
GIVEN STRONG DOWNSLOPE COMPONENT TO FLOW AND UPSTREAM DRY AIR ON
REGIONAL SOUNDINGS. THERE VERY WELL COULD BE FAIRLY TIGHT MOISTURE
GRADIENT LATE TODAY JUST EAST OF INTERSTATE-44 CORRIDOR. THIS WILL
BE WATCHED CLOSELY...AND IF NEED BE...ADJUSTMENTS TO CURRENT RED
FLAG WARNING WILL BE MADE. ALTHOUGH IT WILL BE WINDY AND WARM
ACROSS CENTRAL AND SOUTHERN PARTS OF OKLAHOMA... WHICH WILL STILL
CREATE WILDFIRE CONCERNS...CURRENT HUMIDITY FORECAST EXPECTED TO
KEEP OKC AND POINTS SOUTH AND EAST OUTSIDE OF RED FLAG CRITERIA.
WITH ALL OF THAT BEING TYPED...OUTDOOR BURNING AND OTHER ACTIVITIES
THAT COULD LEAD TO WILDFIRES IS DISCOURAGED ACROSS ALL OF OKLAHOMA
AND WESTERN NORTH TEXAS. THERE ARE BURN BANS IN EFFECT ACROSS
NORTH TEXAS.
COLD FRONT WILL MOVE INTO NORTHERN OKLAHOMA MID-LATE
AFTERNOON...WHICH WILL EFFECTIVELY WEAKEN THE PRESSURE GRADIENT
AND ALLOW WINDS TO DECREASE. ALTHOUGH THEY COULD SEE WIND ADVISORY
WORTHY WINDS BRIEFLY LATE THIS MORNING OR EARLY AFTERNOON...THEY
WERE LEFT OUT OF WIND ADVISORY. THIS FRONT WILL BRING IN MUCH
COLDER AIR...WHEN COMPARED TO WHAT WE WILL SEE TODAY. WITH
NUMEROUS COLD FRONTS PASSING OVER THE REGION THROUGH THE WEEK...
TEMPERATURES ARE EXPECTED TO REMAIN NEAR OR SLIGHTLY ABOVE AVERAGE
FOR THE MOST PART. DRY WEATHER EXPECTED.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 70 34 60 32 / 0 10 0 0
HOBART OK 73 32 59 29 / 0 10 0 0
WICHITA FALLS TX 76 35 63 32 / 0 10 0 0
GAGE OK 69 29 59 26 / 0 10 0 0
PONCA CITY OK 67 31 59 31 / 0 10 0 0
DURANT OK 70 42 62 36 / 0 10 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...WIND ADVISORY FROM 10 AM THIS MORNING TO 6 PM CST THIS EVENING
FOR OKZ013-016>047-050-051.
RED FLAG WARNING FROM NOON TODAY TO 6 PM CST THIS EVENING FOR
OKZ014-016-021>023-027-033>039-044-045.
TX...WIND ADVISORY FROM 10 AM THIS MORNING TO 6 PM CST THIS EVENING
FOR TXZ083>090.
RED FLAG WARNING FROM NOON TODAY TO 6 PM CST THIS EVENING FOR
TXZ083>090.
&&
$$
06/11/11
AREA FORECAST DISCUSSION
NWS NORMAN OK
422 AM CST SUN JAN 12 2014
.DISCUSSION...
VERY WARM...DRY...AND WINDY CONDITIONS ACROSS THE REGION TODAY. WE
WENT WITH THE RAP MODEL FOR SHORT-TERM FORECAST SOLUTION WHICH
SPREADS RED FLAG WILDFIRE CONDITIONS ACROSS A LARGE PART OF
WESTERN OKLAHOMA AND WESTERN NORTH TEXAS. THIS SOLUTION IS MUCH
DRIER THAN OTHER GUIDANCE AND WILL LIKELY BE CLOSER TO VERIFYING
GIVEN STRONG DOWNSLOPE COMPONENT TO FLOW AND UPSTREAM DRY AIR ON
REGIONAL SOUNDINGS. THERE VERY WELL COULD BE FAIRLY TIGHT MOISTURE
GRADIENT LATE TODAY JUST EAST OF INTERSTATE-44 CORRIDOR. THIS WILL
BE WATCHED CLOSELY...AND IF NEED BE...ADJUSTMENTS TO CURRENT RED
FLAG WARNING WILL BE MADE. ALTHOUGH IT WILL BE WINDY AND WARM
ACROSS CENTRAL AND SOUTHERN PARTS OF OKLAHOMA... WHICH WILL STILL
CREATE WILDFIRE CONCERNS...CURRENT HUMIDITY FORECAST EXPECTED TO
KEEP OKC AND POINTS SOUTH AND EAST OUTSIDE OF RED FLAG CRITERIA.
WITH ALL OF THAT BEING TYPED...OUTDOOR BURNING AND OTHER ACTIVITIES
THAT COULD LEAD TO WILDFIRES IS DISCOURAGED ACROSS ALL OF OKLAHOMA
AND WESTERN NORTH TEXAS. THERE ARE BURN BANS IN EFFECT ACROSS
NORTH TEXAS.
COLD FRONT WILL MOVE INTO NORTHERN OKLAHOMA MID-LATE
AFTERNOON...WHICH WILL EFFECTIVELY WEAKEN THE PRESSURE GRADIENT
AND ALLOW WINDS TO DECREASE. ALTHOUGH THEY COULD SEE WIND ADVISORY
WORTHY WINDS BRIEFLY LATE THIS MORNING OR EARLY AFTERNOON...THEY
WERE LEFT OUT OF WIND ADVISORY. THIS FRONT WILL BRING IN MUCH
COLDER AIR...WHEN COMPARED TO WHAT WE WILL SEE TODAY. WITH
NUMEROUS COLD FRONTS PASSING OVER THE REGION THROUGH THE WEEK...
TEMPERATURES ARE EXPECTED TO REMAIN NEAR OR SLIGHTLY ABOVE AVERAGE
FOR THE MOST PART. DRY WEATHER EXPECTED.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 70 34 60 32 / 0 10 0 0
HOBART OK 73 32 59 29 / 0 10 0 0
WICHITA FALLS TX 76 35 63 32 / 0 10 0 0
GAGE OK 69 29 59 26 / 0 10 0 0
PONCA CITY OK 67 31 59 31 / 0 10 0 0
DURANT OK 70 42 62 36 / 0 10 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...WIND ADVISORY FROM 10 AM THIS MORNING TO 6 PM CST THIS EVENING
FOR OKZ013-016>047-050-051.
RED FLAG WARNING FROM NOON TODAY TO 6 PM CST THIS EVENING FOR
OKZ014-016-021>023-027-033>039-044-045.
TX...WIND ADVISORY FROM 10 AM THIS MORNING TO 6 PM CST THIS EVENING
FOR TXZ083>090.
RED FLAG WARNING FROM NOON TODAY TO 6 PM CST THIS EVENING FOR
TXZ083>090.
&&
$$
06/11
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1009 AM MST SUN JAN 12 2014
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 308 AM MST SUN JAN 12 2014
SURFACE COLD FRONT STRETCHED FROM WRN WY ACROSS NRN UT TO SRN NV AT
09Z. REGIONAL RADARS SHOWED PRECIP GENERALLY CONFINED TO ALONG AND
BEHIND THE FRONT...WITH RAIN REPORTED AT SLC. THE UPPER LOW CENTER
WAS CROSSING THE NRN ROCKIES WITH AN EAST-SOUTHEAST PUSH TO THE
ASSOCIATED TROUGH EXTENDING DOWN TO NRN NV. WHERE GUSTY WINDS
DEVELOP AT THE SURFACE...THE TURBULENT MIXING HAS RESULTED IN TEMPS
EXHIBITING A SPIKE UPWARDS. MEEKER AND CRAIG BOTH TOUCHED 40F
EARLIER IN THE NIGHT WHEN THIS OCCURRED.
PRECIPITATION HAS BE SLOW TO START OVER OUR AREA THOUGH STRONG
LOW-LEVEL WARM ADVECTION LIKELY PUTTING AT LEAST SOME AREAS OF LIGHT
SNOW OVER THE HIGHER ELEVS OF THE ERN UINTAS AND NRN CO MTNS. A FEW
MTN SNOTEL SITES REGISTERING LIGHT AMOUNTS SUPPORT THIS. CLOUDS
BASES HAVE BEEN SLOWLY LOWERING...SO SUSPECT THAT PRECIP WILL BE
RAMPING UP BY 12Z WHEN THE RUC13 MODEL HAS THE FRONT REACHING A
MOAB-CRAIG LINE....AND THEN TO THE SAN JUANS BY MIDDAY. AS THE UPPER
JET ON THE FRONT SIDE OF THE TROUGH MOVES OVERHEAD...THE COMBINATION
OF DYNAMICS AND FRONTAL LIFT WITH DEEP INSTABILITY SHOULD BRING
WIDESPREAD SNOW TO THE MOUNTAINS AND TO MANY NORTHERN AND CENTRAL
VALLEYS THIS MORNING. STRONG WINDS ALOFT WITH GUSTY WINDS AT THE
SURFACE WILL PRODUCE AREAS OF BLOWING SNOW ACROSS THE NORTH AND
CENTRAL AREAS. STRONGEST WINDS SHOULD BE OVER THE FLATTOPS AND
ELKHEAD/PARK/GORE MTNS. SNOW AND BLOWING SNOW WILL MAKE TRAVEL VERY
DIFFICULT OVER RABBIT EARS AND VAIL PASSES THIS AFTERNOON AND
EVENING...AND PROBABLY MONDAY TOO.
AS THE FRONT AND UPPER TROUGH MOVE PAST... FORCING BECOMES MORE
OROGRAPHICALLY DRIVEN AS NORTHWEST FLOW SETS UP THIS AFTERNOON AND
EVENING. PRECIPITABLE WATER AND SPECIFIC HUMIDITY VALUES DROP QUICKLY
BEHIND THE FRONT TODAY...BUT THE NAM/GFS MAINTAIN A MOIST DENDRITIC
SNOW GROWTH LAYER ACROSS THE NRN MTNS WITH A SECOND PUSH OF MOISTURE
TONIGHT THAT SHOULD HELP MAINTAIN SNOW THERE INTO MONDAY.
ASIDE FROM THE BIT SLOWER START TO PRECIPITATION...THE CURRENT
FORECAST GRIDS AND WINTER HIGHLIGHTS LOOK ON TRACK. MADE ONLY MINOR
CHANGES SUCH AS TO EXPAND BLOWING SNOW IN THE GRIDS INTO MORE OF
THE NW CO VALLEYS TODAY
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 308 AM MST SUN JAN 12 2014
NWLY FLOW WILL KEEP SOME SNOW SHOWERS IN THE PICTURE FOR THE NRN
MTNS THOUGH ACCUMULATIONS WILL BE ON THE LIGHT SIDE MONDAY NIGHT
INTO TUESDAY. BOTH THE GFS AND NAM HIGHLIGHT THIS PRECIP THROUGH TUE
AFTN SO KEPT CHCS FOR PRECIP IN FORECAST. AFTER THAT...A LARGE
RIDGE OF HIGH PRESSURE TO THE WEST WILL BUILD IN KEEPING OUR CWA
HIGH AND DRY THROUGH THE REMAINDER OF THE FORECAST PERIOD. SOME
DISCREPANCIES POP UP TOWARDS THE WEEKEND BTWN THE EC AND GFS BUT
LOW CONFIDENCE IN FORECAST AS SOLNS ARE SO FAR OUT.
EXPECT TEMPERATURES TO CLIMB A FEW DEGREES ABOVE NORMAL FOR THIS
TIME OF YEAR FROM TUESDAY ONWARDS EXCEPT FOR THOSE VALLEYS WHERE
INVERSIONS SET UP...THE GRAND VALLEY...TELLURIDE AND DURANGO TO
NAME A FEW.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY NOON)
ISSUED AT 1010 AM MST SUN JAN 12 2014
AT 10AM THE COLD FRONT HAD WORKED INTO THE SAN JUAN MOUNTAINS AND
WILL PUSH SOUTHEAST OF THE ENTIRE FORECAST AREA BY EARLY
AFTERNOON. CONVECTIVE SNOW SHOWERS WILL BE WIDESPREAD THROUGH 00Z
FOR ALL TAF SITES EXCEPT DRO. IN SHOWERS EXPECT CIGS AOB 010 AND
VSBY AOB 1SM. MOUNTAINS WILL BE FQTLY OBSCURED. BY THIS
EVENING...SNOWFALL WILL CONTINUE FOR THE NRN AND CENTRAL MTNS. FOR
KHDN...KSBS...KEGE...KASE EXPECT CIGS BLOW 030 VSBY BLO 3SM IN SN
BR. ALONG WITH SNOW...EXPECT GUSTY WINDS WITH SOME BLOWING SNOW
EXPECTED ALSO DROPPING VISIBILITIES. STRONGER WINDS CAN BE
EXPECTED AT HIGHER ELEVATIONS CAUSING SOME MECHANICAL TURBULENCE
WHILE MTN OBSCURATIONS WILL BE COMMON TONIGHT THROUGH MONDAY
MORNING.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER WEATHER ADVISORY UNTIL 9 PM MST THIS EVENING COZ008-014.
WINTER STORM WARNING UNTIL MIDNIGHT MST TONIGHT COZ009-012-018.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT MST TONIGHT COZ003-017.
WINTER STORM WARNING UNTIL 5 PM MST MONDAY COZ004-010-013.
WINTER STORM WARNING UNTIL 3 AM MST MONDAY COZ005.
WINTER STORM WARNING UNTIL 5 PM MST THIS AFTERNOON COZ002.
UT...NONE.
&&
$$
SHORT TERM...JAD
LONG TERM...TGR
AVIATION...TGR
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
325 PM EST SUN JAN 12 2014
.SYNOPSIS...
19Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS THE SHARP UPPER LEVEL
TROUGH RESPONSIBLE FOR SATURDAYS STORMS NOW WELL EAST INTO THE
WESTERN ATLANTIC. REBOUNDING HEIGHTS AND STRONG SUBSIDENCE IN THE
WAKE OF THIS FEATURE HAVE EXPANDED OVER THE FLORIDA PENINSULA. AN
IMPRESSIVE TONGUE OF DRY MID/UPPER LEVEL AIR IS SEEN IN WATER VAPOR
OVER NORTHERN FLORIDA WITH MOISTURE GRADUALLY INCREASING SOUTHWARD
AS OVERALL SYNOPTIC SUBSIDENCE WEAKENS. 12/12Z KTBW SOUNDING PROFILE
SHOWS THAT THIS DRY AIR EXTENDS THROUGH MUCH OF THE TROPOSPHERE...
WITH IMPRESSIVE DEWPOINT DEPRESSIONS OBSERVED DOWN TO ALMOST 900MB.
THE SYNOPTIC SUBSIDENCE CAN ALSO BE SEEN STRONGLY IN THE COLUMN PW
WHICH DROPPED FROM A HIGH 1.77" LAST EVENING TO A LOW 0.36" BY THIS
MORNING.
LOOKING UPSTREAM IN THE UPPER LEVELS WE SEE WEAK RIDGING EXPANDING
EASTWARD FROM THE CENTRAL CONUS. THIS RIDGING WILL PROVIDE FAIR AND
SEASONABLE WEATHER FOR THE REGION THROUGH MUCH OF MONDAY.
HOWEVER...FURTHER UPSTREAM WE SEE OUR NEXT WEATHER MAKER IN THE FORM
OF A DIGGING TROUGH THROUGH THE INTER-MOUNTAIN WEST. THIS ENERGY
WILL BE QUITE PROGRESSIVE THE NEXT DAY OR TWO AS IT CONTINUES TO
AMPLIFY. THE LARGE SCALE FORCING AND INCREASED RAIN CHANCES
ASSOCIATED WITH THIS NEXT SYSTEM ARE SCHEDULED TO ARRIVE ACROSS
NORTHERN AND CENTRAL FLORIDA BY MONDAY NIGHT. SO...IT WILL BE A
QUICK BOUT OF FAIR WEATHER BETWEEN STORMS...BUT AT LEAST WE MANAGED
TO SALVAGE A SUNNY AND DRY WEEKEND DAY.
AT THE SURFACE...1020+MB HIGH PRESSURE HAS BECOME CENTERED OVER
NORTHERN FLORIDA BY THIS AFTERNOON...AND THEN WILL SHIFT OFF THE
SOUTHEAST CONUS COAST OVERNIGHT.
&&
.SHORT TERM (TONIGHT THROUGH TUESDAY NIGHT)...
EXPECTING A COOLER NIGHT WITH THE DRY AIR IN PLACE AND THE CLOSE
PROXIMITY OF THE SURFACE RIDGE. HOWEVER...THIS AIRMASS IS NOTHING
LIKE THE ONE FROM LAST WEEK...AND WE DO NOT ANTICIPATE ANY
SUB-FREEZING TEMPS TO OCCUR. A FEW VERY ISOLATED PATCHES OF FROST
ARE NOT OUT OF THE QUESTION FOR LEVY COUNTY AT THE NORMALLY COLDER
AND MORE EFFICIENT RADIATIONAL COOLING SITES...BUT EVEN THIS MAY BE
A STRETCH. ELSEWHERE LOW TEMPS BY SUNRISE ON MONDAY WILL RANGE FROM
THE 40S NORTH OF THE I-4 CORRIDOR TO THE UPPER 40S AND LOWER 50S
ACROSS CENTRAL FLORIDA AND THE LOWER/MID 50S DOWN TOWARD FORT MYERS.
MAY SEE SOME INCREASE IN THIN HIGH CIRRUS DURING THE OVERNIGHT...BUT
WILL CONTINUE TO CALL IT MOSTLY CLEAR.
MONDAY/MONDAY NIGHT...UPPER TROUGH AND ASSOCIATED SYNOPTIC FORCING
WILL BEGIN TO SPREAD EASTWARD ALONG THE NORTHERN GULF COAST.
MID/UPPER LEVEL PV ANOMALY DIGGING TOWARD THE CENTRAL GULF COAST AND
AN ASSOCIATED STRONG JET STREAK ALIGNED ALONG AND EAST OF THE MS
VALLEY SHOULD INITIATE WEAK CYCLOGENESIS OVER THE NORTH-CENTRAL GULF
OF MEXICO BAROCLINIC ZONE DURING THE DAY...WITH AN ATTENDANT WARM
FRONT DEVELOPING EASTWARD TO NORTH FLORIDA BY EVENING. MOST OF THE
GLOBAL GUIDANCE DOES NOT SHOW ANY QPF OVER THE NORTHERN NATURE COAST
BEFORE MONDAY NIGHT...HOWEVER NWP GUIDANCE IS ALMOST ALWAYS BIASED
ON THE SLOW SIDE TOWARD COLUMN MOISTENING AND PRECIP INITIATION
WITHIN ISENTROPIC UPGLIDE REGIMES. WITH THIS IN MIND FEEL AT LEAST A
SMALL RAIN CHANCE IS WARRANTED UP TOWARD CITRUS/LEVY COUNTY BY THE
SECOND HALF OF MONDAY AFTERNOON. THE BEST CHANCES
(LIKELY/CATEGORICAL) FOR RAIN OVER NORTHERN AND CENTRAL FLORIDA
WILL THEN ARRIVE MONDAY NIGHT AS THE HEIGHT FALLS/DCVA AND RRQ JET
DYNAMICS BECOME MOST COINCIDENT OVER THE REGION.
TUESDAY/TUESDAY NIGHT..
UPPER LEVEL PV ANOMALY QUICKLY PIVOTS NORTHEASTWARD EARLY TUESDAY
AND IS NOT IN GOOD PHASE WITH THE LOWER LEVEL CYCLONE RESULTING IN
LITTLE IF ANY DEEPENING TO THE LOW AS IT CROSSES GA TOWARD THE
ATLANTIC SEABOARD. TRAILING COLD FRONT WILL SLOWLY SHIFT SOUTH
THROUGH THE DAY WHILE OVERALL SYNOPTIC FORCING FOR ASCENT AND UPPER
JET BOTH WEAKEN OVERHEAD WITH TIME. WITH ALL THIS IN MIND WOULD
EXPECT THE BAND OF SHOWERS/AREAS OF RAIN TO SLOWLY SHIFT SOUTH
THROUGH THE PENINSULA AND BECOME LESS ORGANIZED THROUGH THE DAY. NOT
A SIGNIFICANT PUSH OF COLDER AIR BEHIND THIS FIRST FRONT...SO THE
TEMPERATURE POTENTIAL WILL STILL BE QUITE WARM...IT WILL SIMPLY
DEPEND ON THE DEGREE OF CLOUDS AND SHOWERS. FOR NOW...70S SEEM A
GOOD BET FOR ALL BUT THE FAR NORTHERN NATURE COAST...ESPECIALLY
SINCE MONDAY NIGHT WILL BE AN OVERALL WARM NIGHT FROM WHICH THE
TEMPERATURES CAN BEGIN THEIR DIURNAL RECOVERY. TUESDAY NIGHT...THE
BEST INDICATIONS ARE THAT THE FRONT WILL CLEAR OUR REGION ALONG WITH
ANY LOW LEVEL FOCUS FOR SHOWERS. THE SREF ENSEMBLES HAVE BEEN TRYING
TO KEEP SOME RESIDUAL MOISTURE OVER SOUTH FLORIDA AND WILL KEEP A
SLIGHT CHANCE POP DOWN TOWARD FORT MYERS IN CASE THEY VERIFY.
ELSEWHERE...THE FORECAST IS RAIN-FREE. OUR EYES HOWEVER WILL BE
TURNING TO OUR NORTH AT THIS POINT AS ANOTHER SHARP AND DEEP TROUGH
DIGS INTO THE EASTERN HALF OF THE NATION. THIS TROUGH WILL PROPEL A
MUCH STRONGER FRONT (BUT DRY) THROUGH THE PENINSULA DURING
WEDNESDAY.
POTENTIAL FREEZE EVENT...WHILE STILL SEVERAL DAYS AWAY...GLOBAL
GUIDANCE MEMBERS ARE IN GOOD AGREEMENT OF A MUCH STRONGER BLAST OF
COLD AIR ARRIVING INTO THE PENINSULA BY WEDNESDAY NIGHT. POTENTIAL
FOR FREEZING TEMPERATURES IS CERTAINLY THERE FOR BOTH WEDNESDAY
NIGHT AND THURSDAY NIGHT...ESPECIALLY OVER THE NATURE COAST. LOW
WIND CHILLS ARE LIKELY FOR ALL OF THE REGION WEDNESDAY NIGHT/EARLY
THURSDAY MORNING. THOSE WITH AGRICULTURAL INTEREST OR OUTDOOR PLANS
FOR LATER THIS WEEK SHOULD MONITOR THE LATEST FORECASTS WITH REGARD
TO THIS POTENTIAL FREEZE EVENT.
&&
.LONG TERM (WEDNESDAY THROUGH NEXT SATURDAY)...MODEL SOLUTIONS HAVE
COME INTO BETTER AGREEMENT AND ONLY MINOR DIFFERENCES ARE NOTED
THROUGH THE LONG TERM PERIOD. WEAK HIGH PRESSURE WILL BUILD IN
BEHIND A DEPARTING COLD FRONT TUESDAY NIGHT...WITH ANOTHER
RE-ENFORCING COLD FRONT TAKING AIM ON THE AREA FOR WEDNESDAY. THIS
COLD FRONT WILL SWING THROUGH THE REGION DURING THE DAY ON
WEDNESDAY...WITH HIGH PRESSURE THEN BUILDING BACK INTO THE AREA
THROUGH THE REMAINDER OF THE WORK WEEK. ANOTHER COLD FRONT IS THEN
EXPECTED TO MOVE THROUGH THE AREA FRIDAY NIGHT...WITH HIGH PRESSURE
THEN BUILDING BACK INTO THE REGION OVER THE UPCOMING WEEKEND.
AS FOR FORECAST DETAILS...WILL CARRY SLIGHT CHANCE POPS TUESDAY
NIGHT AS A FEW SHOWERS MAY LINGER OVER SOUTHERN ZONES BEHIND THE
DEPARTING COLD FRONT DURING THE EVENING HOURS. OTHERWISE...EACH
SUCCESSIVE COLD FRONT WILL LACK ANY RETURN FLOW MOISTURE FROM THE
GULF OF MEXICO...SO WE ANTICIPATE DRY FRONTAL PASSAGES AND WILL KEEP
THE FORECAST FREE FROM RAIN. TEMPERATURES ARE EXPECTED TO REMAIN
BELOW NORMAL THROUGH THE LONG TERM PERIOD.
&&
.AVIATION...
12/18Z-13/18Z...VFR WITH FEW-SCT CLOUDS ALTHOUGH SOUTHERN TERMINALS
MAY SEE A FEW MORE CLOUDS AND SOONER AS MOISTURE RETURNS. NORTHERLY
WINDS BECOME LIGHT VARIABLE/EASTERLY OVERNIGHT THEN SE AFTER SUNRISE.
&&
.MARINE...
WINDS AND SEAS CONTINUE TO GRADUALLY SUBSIDE THIS AFTERNOON WITH ALL
HEADLINES NOW DROPPED. WINDS WILL SHIFT EAST AND THEN SOUTHEAST
TONIGHT INTO MONDAY AS HIGH PRESSURE PASSES OFF INTO THE ATLANTIC.
THE NEXT COLD FRONT IS FORECAST TO PASS THROUGH THE EASTERN GULF
MONDAY NIGHT OR EARLY TUESDAY.
&&
.FIRE WEATHER...
AFTER A DRY DAY TO END THE WEEKEND...HIGH PRESSURE WILL SHIFT EAST
AND ALLOW SOME ATLANTIC MOISTURE TO ONCE AGAIN MOVE INTO THE
REGION. TEMPERATURES WILL BE WARMER ON MONDAY...HOWEVER WITH THE
INCREASING LOW LEVEL MOISTURE...NO CRITICAL LEVELS OF RELATIVE
HUMIDITY ARE ANTICIPATED. A WEAK COLD FRONT WILL CROSS THE REGION
MONDAY NIGHT AND TUESDAY WITH ANOTHER BOUT OF SHOWERS AND STORMS. A
STRONGER COLD FRONT WILL THEN CROSS THE REGION ON WEDNESDAY USHERING
IN A VERY DRY AND WELL BELOW NORMAL TEMPERATURE REGIME FOR THE END
OF THE WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 53 76 65 71 / 10 10 70 60
FMY 57 82 66 77 / 10 10 40 50
GIF 50 78 61 73 / 10 10 60 60
SRQ 53 76 67 71 / 0 10 60 60
BKV 41 76 62 71 / 10 10 80 60
SPG 57 76 66 69 / 10 10 70 60
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/MARINE/FIRE WX...MROCZKA
AVIATION...RUDE
LONG TERM...JELSEMA
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1207 PM CST SUN JAN 12 2014
.UPDATE...
ISSUED AT 854 AM CST SUN JAN 12 2014
HAVE HAD TO ISSUE A RATHER SHORT FUSE FREEZING RAIN ADVISORY IN
CENTRAL MINNESOTA FOR AREA OF LIGHT RAIN MOVING THROUGH. ALTHOUGH
MOST REPORTING LOCATIONS HAVE ONLY REPORTED PRECIP FOR 1 TO 2
HOURS...WITH TEMPERATURES RANGING FROM 28 TO 32...WE HAVE SEEN A
SIGNIFICANT AMOUNT OF TRAVEL CONCERNS DEVELOP ACROSS CENTRAL MN
WITH ICING CONDITIONS. MNDOT TRAVEL MAP HAS CATEGORIZED ROADS
ACROSS CENTRAL MN AS HAZARDOUS WITH TRAVEL NOT ADVISED...WHICH WAS
A BIG REASON FOR ISSUING THIS ADVISORY.
HOPWRF AND HRRR SHOW THIS BAND OF PRECIP LIFTING NE TOWARD
DLH...SO SEE NO NEED TO EXPAND THE FREEZING RAIN ADVISORY EAST
INTO WEST CENTRAL WI...AS ALL SHORT TERM MODELS INDICATE THAT THEY
WILL SEE NO PRECIPITATION OVER THERE. THE WEST EDGE OF THE ADVISORY
WAS SET BASED ON WHERE PRECIP IS CURRENTLY FALLING...COULD HAVE
ADDED BENSON UP THROUGH ALEXANDRIA TO THE ADVISORY...BUT RAIN
THERE IS ALREADY DONE...WITH TEMPERATURES ALREADY STARTING TO
SNEAK ABOVE FREEZING WEST OF THE ADVY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 228 AM CST SUN JAN 12 2014
LATEST WATER VAPOR IMAGERY SHOWS HIGH CLOUDS AND MOISTURE MOVING
EAST WITH THE UPPER RIDGE AXIS ACROSS THE REGION AT THE CURRENT
TIME. THIS HAS HELPED TO INCREASE THE MID-HIGH CLOUDS OVER OUR
AREA... WITH LOWER CLOUDS STILL TO THE WEST WHERE SOME PCPN IS
APPARENT ON RADAR AND SURFACE OBS. THAT PCPN IS PRIMARILY BEING
FORCED BY SOME DECENT ISENTROPIC LIFT AHEAD OF THE UPPER TROUGH...
WHICH IS LAGGING BACK WELL TO THE WEST. THE CURRENT AREA OF PCPN
WILL TRY TO HOLD TOGETHER AS IT MOVES EAST TODAY... BUT IT STILL
APPEARS THAT THE BEST CHANCE FOR PCPN WILL BE OVER THE FAR NORTHERN
PART OF THE FORECAST AREA... WHERE DEEPER MOISTURE LOOKS TO BE
PRESENT THROUGH THE DAY. HOWEVER... EVEN THERE IT DOESN/T APPEAR AS
THOUGH PCPN AMOUNTS WILL BE SUBSTANTIAL... AND IT/S POSSIBLE SOME
LOCATIONS WON/T MEASURE AT ALL... SO STILL KEPT POPS AS CHANCES
RATHER THAN LIKELY. PCPN-TYPE WITH WHATEVER OCCURS WILL BE TRICKY...
SINCE TEMPERATURES ARE ALREADY CLIMBING ABOVE FREEZING ALOFT... AS
WAS EVIDENT IN THE UPSTREAM SOUNDINGS AT 00Z WHICH SHOWED THE WARM
NOSE AROUND 900-850MB. WITH CONTINUED WARM ADVECTION THROUGH THE DAY
THAT SITUATION SHOULDN/T IMPROVE. SO... WOULD EXPECT PARTIAL TO
COMPLETE MELTING OF PCPN ALOFT... BUT SURFACE TEMPERATURES WILL TAKE
A BIT OF TIME BEFORE THEY CLIMB ABOVE FREEZING TODAY... SO THERE
STILL APPEARS TO BE A CHANCE FOR SOME SLEET AND FREEZING
RAIN/DRIZZLE THIS MORNING WITH ANY PCPN WHICH MOVES ACROSS THE
NORTHERN PORTION OF THE AREA. BUT... AS MENTIONED... WHATEVER OCCURS
SHOULD BE LIGHT. THE UPPER TROUGH CURRENTLY EVIDENT ON WATER VAPOR
OVER THE WESTERN US WILL CONTINUE TO MOVE EAST TONIGHT... AND LOOKS
TO MOVE INTO THE WESTERN PART OF OUR AREA AFTER 06Z. WE/LL SEE AN
INITIAL COLD FRONT MOVE THROUGH THIS EVENING... WHICH WON/T DO TOO
MUCH TO COOL THINGS OFF... BUT WILL SERVE TO SHIFT WINDS AROUND TO
THE WEST AND NORTHWEST... FURTHER LIMITING THE CHANCE FOR ANY
MOISTURE RETURN AHEAD OF THE UPPER TROUGH AND MORE MEANINGFUL COLD
FRONT WHICH MOVES THROUGH OVERNIGHT. THERE COULD BE SOME LIGHT PCPN
LATE TONIGHT AS THE UPPER TROUGH AND SECONDARY FRONT MOVE THROUGH...
BUT AT THIS POINT IT DOESN/T LOOK TO BE ANY MORE THAN FLURRIES... SO
DIDN/T INCLUDE ANYTHING IN THE FORECAST. THE MAIN THING WILL BE THE
PUSH OF COLDER AIR THE SYSTEM BRINGS.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 228 AM CST SUN JAN 12 2014
THE EXTENDED PERIOD WILL BE MARKED WITH A TWO STORM SYSTEMS WHICH
WILL AFFECT THE UPPER MIDWEST EARLY TUESDAY...AND THEN THURSDAY.
BOTH OF THESE SYSTEMS WILL HAVE A STRONG INFLUENCE OF THICKNESS
VALUES RISING ENOUGH TO CONSIDER A MIXTURE OF SLEET/FREEZING
RAIN/RAIN IN THE FAR SW CWA. EVEN IF WE DO GET PRECIPITATION IN
THIS AREA...THE INCREASING THICKNESS VALUES AND ASSOCIATED 85/92H
TEMPS RISING TO LIMIT THE BEST FORMATION OF ICE CRYSTALS /MORE
FREEZING RAIN/DRIZZLE AND SUPERCOOLED LIQUID WATER DROPLETS/...WILL
LIMIT SNOWFALL AMTS. BEST CHC OF RECEIVING MEASURABLE
PRECIPITATION IN SW/SC MN WILL OCCUR WITH EARLY TUESDAY/S SYSTEM.
TAKING A CROSS SECTION ALONG A KOMA TO KDLH LINE INDICATES THAT
BOTH THE GFS/EC HAVE SIMILAR SCENARIO/S OF A BRIEF PERIOD OF
STRONG LIFT ARND 6Z TUESDAY IN THE DENDRITIC SNOW ZONE. FORCING IS
VERY LIMITED 6 HRS BEFORE AND AFTER THIS TIME FRAME. AS DISCUSS
WITH THICKNESS VALUES AND THE INFLUENCE OF HIGHER 92H/85H
TEMPS...SNOWFALL AMTS MAY BE LIGHTER THAN EXPECTED. EVEN WITH A 13
TO 15-1 SNOWFALL RATIO BETWEEN 00-12Z TUESDAY...SNOWFALL AMTS WILL
RANGE FROM 1" TO 2.5". ALTHOUGH MODELS HAVE BEEN MORE CONSISTENT
IN TERMS OF A SFC LOW DEVELOPING ACROSS THE DAKOTAS...AND MOVING
THIS SYSTEM RAPIDLY SE ACROSS THE MIDWEST TUESDAY AFTN...PLACEMENT
OF THE SFC LOW WILL BE CRITICAL IN TERMS OF WHERE THE HEAVIER SNOW
BANDS DEVELOP EARLY TUESDAY. BASED ON CURRENT MODELS...THE BEST
PLACEMENT AND ASSOCIATED QPF FIELD HAS A BAND OF 1.5 TO 2.5" OF
SNOWFALL FROM LONG PRAIRIE...SE TO THE NORTHERN SUBURBS OF THE
TWIN CITIES...TO RIVER FALLS WI. ANY DEVIATION OF THIS SFC
LOW...OR STRONGER INFLUX OF WARMER AIR FROM THE SW...WILL LIMIT
SNOWFALL AMTS.
THURSDAY SYSTEM LOOKS TO BE MAINLY IN THE FORM OF SNOW...BUT DUE
TO THE FAST NATURE OF THE SYSTEM AND LIMITED DEEP MOISTURE AND
LIFT...AMTS WILL BE LIGHT AND FOCUSED NE OF MPX CWA. THE MAJOR
DIFFERENCES BETWEEN TUESDAY/S AND THURSDAY/S SYSTEM IS THE
PRESSURE GRADIENT AND ASSOCIATED STRONG SFC WIND FIELD. BASED ON
THE SFC WINDS AND GUST POTENTIAL...AND IF ANY SNOW CAN BE PICK UP
FROM THE GROUND...BLIZZARD LIKE CONDS MAY DEVELOP...ESPECIALLY IN
THE TYPICAL AREAS OF WC/SW/SC MN THU/THU NIGHT. HAVE INTRODUCED
BLOWING SNOW DURING THIS TIME FRAME...BUT IF CURRENT MODEL TRENDS
HAVE THE CONTINUED SFC PRESSURE GRADIENT FIELD THE SAME...A
BLIZZARD WATCH OR SOME OTHER HIGHLIGHTED WX EVENT IS POSSIBLE.
BEHIND THIS SYSTEM...ANOTHER ARCTIC OUTBREAK WILL OCCUR...BUT NOT
AS COLD AS THE FIRST WEEK OF JANUARY. 92H/85H TEMPS ARE 10 TO 15
DEGREES WARMER THAN THE ARCTIC CORE FROM EARLIER THIS MONTH.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1207 PM CST SUN JAN 12 2014
LAST VESTIGES OF LIGHT FREEZING RAIN EXITING THE AREA JUST NORTH
AND NORTHEAST OF KSTC AS OF 18Z. JUST MID AND HIGH CLOUDS INTO THIS
EVENING. NEXT WEAK TROUGH WILL ENTER WEST CENTRAL MN AFTER 06Z.
SECONDARY COLD FRONT WILL BE ASSOCIATED WITH THIS AND MOISTURE
PROFILE SUGGESTS MVFR CEILINGS OVER MOST OF THE AREA FOR ABOUT 6
HOURS IN ANY GIVEN LOCATION. SOME FLURRIES ARE QUITE POSSIBLE.
VISIBILITIES SHOULD MOSTLY BE UNRESTRICTED...BUT THERE IS A SMALL
CHANCE OF GETTING TO 5SM FOR AN HOUR OR SO. ONCE THAT GOES
BY...STRONGER TROUGH AND SNOW WILL ARRIVE IN WEST CENTRAL MN
MONDAY AFTERNOON... JUST BEYOND THE 24 HOUR PERIOD FOR TAFS. NEXT
TAF SET WILL LIKELY REFLECT THE INCOMING SNOW.
KMSP...JUST SOME MID AND HIGH CLOUDS THROUGH MOST OF THE PERIOD.
THERE IS A SMALL CHANCE THAT LIGHT SNOW WILL BEGIN AROUND THE 30
HOUR TIME FRAME BUT IT IS MORE LIKELY TO START MONDAY EVENING AT
KMSP. ONLY OTHER MATTER IS WIND. SOUTHWEST WIND SHOULD REMAIN
AROUND 10 KNOTS FOR SEVERAL HOURS THIS AFTERNOON THEN TAPER OFF A
BIT AS GRADIENT WEAKENS. SECONDARY COLD FRONT WILL ARRIVE LATE
TONIGHT WITH AN INCREASE TO AROUND 10 KNOTS. MIGHT BE SOME GUSTS
TO 15 KNOTS BUT HAVE NOT INCLUDED THAT RIGHT NOW.
/OUTLOOK FOR KMSP/
MONDAY NIGHT...MVFR CEILINGS/VISIBILITIES EXPECTED WITH SNOW...
IFR CONDITIONS POSSIBLE. SOUTHWEST WIND 10 TO 15 KT.
TUESDAY...MVFR CEILINGS/VISIBILITIES EXPECTED WITH LIGHT SNOW
POSSIBLE IN THE MORNING...THEN BECOMING VFR. NORTHWEST WIND 15 TO
20 KT.
WEDNESDAY...VFR. NORTHWEST WIND 5 TO 10 KT BECOMING SOUTH 5 TO 10
KT.
THURSDAY...MVFR CEILINGS/VISIBILITIES POSSIBLE WITH A CHANCE OF
SNOW. WEST TO NORTHWEST WIND 15 TO 25 KT WITH GUSTS TO 30 KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
UPDATE...MPG
SHORT TERM...
LONG TERM...JLT
AVIATION...TDK
AREA FORECAST DISCUSSION
NWS DULUTH MN
1204 PM CST SUN JAN 12 2014
.UPDATE...
ISSUED AT 1204 PM CST SUN JAN 12 2014
UPDATED AVIATION SECTION BELOW.
UPDATE ISSUED AT 1011 AM CST SUN JAN 12 2014
MAIN UPPER LEVEL WAVE AXIS AND EFFECTIVE SURFACE WARM FRONT LIE
JUST TO THE WEST OF THE DULUTH CWA AS OF 10 AM..WITH MODERATE TO
STRONG FORCING FOR ASCENT PERSISTING ACROSS MUCH OF THE DULUTH
CWA. IT TOOK A BIT LONGER FOR THE FORCING TO ATTAIN DEEP LAYER
SATURATION THAN THE MODEL GUIDANCE FROM YDAY INDICATED..BUT ONCE
SATURATION WAS ACHIEVED..WE EXPERIENCED A RATHER EXPLOSIVE INCREASE
IN AREAL COVERAGE OF RADAR ECHOES BETWEEN 8-9 AM OVER PRETTY MUCH
THE ENTIRE EASTERN HALF OF THE DULUTH CWA.
PTYPE HAS STILL BEEN A HEADACHE. WITH RAPID NEWD ADVECTION OF
STRONG WARM NOSE ALOFT..PRECIP HAS BEEN ALMOST ALL FREEZING RAIN
SOUTH/WEST OF A LINE ROUGHLY FROM VOYAGEURS N.P. TO SILVER BAY.
HOWEVER..PRECIP IS STARTING AS SNOW OR A WINTRY MIX OVER THE
ARROWHEAD..BUT SHUD TRANSITION TO MORE SLEET/FZRA THERE BY EARLY
AFTERNOON..ALTHOUGH IT MAY BE A BIT HARDER TO WARM THE LOWER PART
OF THE TEMP PROFILE NOW THAT IT IS SATURATED OVER THE ARROWHEAD.
THE MAIN CHANGES FOR THE MORNING UPDATE THAT WAS MADE AVAILABLE
ABOUT 45 MINUTES AGO WERE TO 1) DRASTICALLY INCREASE POPS TO
ACCOUNT FOR WIDESPREAD PRECIP COVERAGE THRU EARLY AFTERNOON 2)
TWEAK PTYPE IN LINE WITH OBS AND SHORT RANGE GUIDANCE 3) INCREASE
SKY COVER TO NEAR 100 PERCENT AND 4) LOWER TEMPS..ESP OVER THE
NORTHEAST HALF OF THE CWA. NO CHANGES WERE MADE TO THE ADVISORY AT
THIS TIME. ADDITIONAL LIGHT PRECIP MAY REDEVELOP ALONG THE WESTERN
EDGE OF THE DULUTH CWA WHERE FORCING FOR ASCENT IS STILL
OCCURRING..BUT TEMPS SHOULD BE PUSHING THE FREEZING POINT OUT WEST
BY MIDDAY AS THE SURFACE WARM FRONT MAKES SLOW EASTWARD PROGRESS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 343 AM CST SUN JAN 12 2014
THIS WAS A CHALLENGING SHORT TERM FORECAST. THE MAIN FOCUS IS ON
THE POTENTIAL FOR FREEZING RAIN AND A WINTRY MIXTURE OF PCPN THIS
MORNING WITH A WARM FRONT IN THE NORTHERN PLAINS EARLY THIS
MORNING THAT WILL MOVE THROUGH THE NORTHLAND TODAY. THIS WARM
FRONT WILL BE ASSOCIATED WITH A LOW PRESSURE SYSTEM MOVING EAST
ACROSS SOUTH CENTRAL CANADA. THE MODEL SOUNDINGS CONTINUE TO
INDICATE A SHORT PERIOD WHERE SNOW ALOFT WILL FALL INTO A
RELATIVELY WARM LAYER ABOVE FREEZING (AROUND 1 TO 4 DEGREES
CELSIUS)...RESULTING IN FREEZING RAIN AND/OR SLEET AS IT FALLS TO
THE COLD SURFACE...WHICH IS BELOW FREEZING THIS MORNING.
THE CHALLENGING PART THOUGH IS THAT THERE ARE STILL SIGNIFICANT
DIFFERENCES BETWEEN THE MODELS AS TO THE TRACK AND PCPN AMOUNTS
TODAY. I WAS HOPING FOR BETTER MODEL AGREEMENT BY NOW COMPARED TO
MY PREVIOUS SHIFT. THE GFS/GEM/ECMWF/RAP13/HRRR PRIMARILY BRING
THE PCPN THROUGH NE MINNESOTA. ON THE OTHER HAND...THE NAM/WRF/GEM
REGIONAL WERE PRIMARILY BRINGING THE PCPN THROUGH THE INTERSTATE
35 CORRIDOR AND NW WISCONSIN. THE GFS IS MUCH MORE AGGRESSIVE WITH
THE PCPN THAN MOST OF THE OTHER MODELS...AND THE 06Z NAM12 CAME IN
WITH NO PCPN. THIS IS QUITE THE RANGE OF DIFFERENCES. IT APPEARS
THE RAP13 AND HRRR MIGHT BE DOING FAIRLY WELL WITH THE CURRENT
PCPN IN THE NORTHERN PLAINS AT THIS POINT...SO I LEANING ON NE
MINNESOTA BEING THE MOST AFFECTED. HOWEVER...I EXPANDED THE
FREEZING RAIN ACCUMULATION AND WINTER WEATHER ADVISORY TO MUCH OF
NW WISCONSIN SINCE THIS AREA COULD EASILY GET A LIGHT COATING OF
ICE TO MAKE FOR DIFFICULT TRAVEL CONDITIONS.
I EXPECT MUCH OF NE MINNESOTA AND NW WISCONSIN TO GET A LIGHT
COATING OF ICE...AROUND A COUPLE HUNDREDTHS OF AN INCH...THIS
MORNING. SOME ISOLATED LOCATIONS COULD GET UP TO AROUND 5
HUNDREDTHS OF AN INCH DEPENDING ON ANY MORE INTENSE SHOWER BANDS
THAT SET UP. THIS WILL LIKELY CAUSE DIFFICULT TRAVEL CONDITIONS
THIS MORNING UNTIL CONDITIONS BEGIN TO IMPROVE THIS AFTERNOON WITH
THE WARMING TEMPERATURES AND AS THE PCPN BEGINS TO EXIT THE
NORTHLAND.
THE MODEL AND MOS GUIDANCE IS IN PRETTY GOOD AGREEMENT WITH HIGH
TEMPERATURES TODAY WITH WIDESPREAD HIGHS IN THE MID 30S. THE
ARROWHEAD WILL MORE LIKELY REACH THE LOW 30S...WHILE THE BRAINERD
LAKES AREA MORE IN THE UPPER 30S. THERE WILL LIKELY BE SOME
PARTIAL CLEARING THIS AFTERNOON IN THE WAKE OF THE WARM FRONT.
TONIGHT...THE CANADIAN LOW PRESSURE WILL MOVE INTO CENTRAL
ONTARIO...AND ITS COLD FRONT WILL MOVE THROUGH THE NORTHLAND. THIS
WILL BRING COLDER TEMPERATURES WITH LOWS DIPPING DOWN TO THE TEENS
AND SINGLE DIGITS ACROSS NE MINNESOTA. THERE COULD BE LIGHT SNOW
WITH LITTLE TO NO ACCUMULATION ACROSS MUCH OF NE MINNESOTA.
MONDAY...HIGH TEMPERATURES WILL BE SIGNIFICANTLY COLDER THAN TODAY
WITH HIGHS IN THE TEENS AND LOW 20S. THERE MIGHT BE LINGERING
LIGHT SNOW IN THE MORNING...AND THEN A WEAK RIDGE OF HIGH PRESSURE
IN THE NORTHERN PLAINS WILL SHIFT INTO THE NORTHLAND DURING THE
AFTERNOON. THIS COULD BRING SOME PARTIAL CLEARING DURING THE
AFTERNOON...BUT I LEANED ON THE CLOUDIER SIDE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 343 AM CST SUN JAN 12 2014
A SERIES OF DISTURBANCES WILL IMPACT THE NORTHLAND THROUGH THE
EXTENDED PERIOD.
A CLIPPER WILL MOVE SOUTHEAST THROUGH THE AREA MONDAY NIGHT INTO
TUESDAY MORNING BRINGING THE POTENTIAL FOR A COUPLE INCHES OF SNOW
TO ABOUT THE SOUTHERN HALF/THIRD OF THE NORTHLAND. THE MODELS ARE
IN BETTER AGREEMENT TONIGHT THAN 24 HOURS AGO...BUT DIFFERENCES
REMAIN. THE ECMWF/GFS ARE FURTHER NORTH WITH THE TRACK OF THE LOW
AND WITH THE PRECIP...BUT THE LATEST NAM HAS TRENDED A BIT FURTHER
SOUTH. WE RAISED POPS TO LIKELY OVER OUR FAR SOUTHERN
ZONES...WHERE THE BEST CHANCE FOR 1 TO 2 INCHES OF SNOW EXISTS.
SOME HIGHER SNOWFALL AMOUNTS WILL ALSO BE POSSIBLE IN THE SNOWBELT
OF ASHLAND/IRON COUNTIES MONDAY NIGHT INTO TUESDAY DUE TO COLDER
AIR MOVING OVER THE LAKE ON NORTHWEST LOW LEVEL FLOW.
MOST AREAS WILL BE DRY TUESDAY AFTERNOON INTO TUESDAY NIGHT AS A
RIDGE MOVES OVER THE REGION. LAKE EFFECT SNOW WILL CONTINUE TO
BE POSSIBLE OVER PORTIONS OF THE SNOWBELT OF ASHLAND/IRON
COUNTIES.
A STRONGER SYSTEM WILL START TO IMPACT THE NORTHLAND WEDNESDAY. A
SURFACE LOW WILL TRACK FROM MANITOBA WEDNESDAY EVENING SOUTHEAST
TOWARD EASTERN LAKE SUPERIOR/NORTHERN MICHIGAN BY THURSDAY
EVENING. A STRONG AREA OF WAA WILL OCCUR AHEAD OF THE LOW
WEDNESDAY...BRINGING A CHANCE FOR PRECIPITATION TO MUCH OF THE
NORTHLAND BY WEDNESDAY AFTERNOON OR WEDNESDAY NIGHT. WE RAISED
POPS WEDNESDAY INTO WEDNESDAY NIGHT FOR MOST AREAS...AS A PERIOD
OF PRECIPITATION IS LOOKING MORE LIKELY. AT THIS TIME...WE HAVE
HIGHEST POPS OVER NORTHERN MINNESOTA. THE SYSTEM DOES NOT LOOK
QUITE AS WARM AS EARLIER MODEL RUNS...BUT WE DID KEEP A MENTION OF
FREEZING RAIN OVER PORTIONS OF OUR SOUTHERN AREA WEDNESDAY
AFTERNOON. LIGHT TO MODERATE SNOW ACCUMULATIONS WILL BE POSSIBLE
FROM WEDNESDAY AFTERNOON INTO THURSDAY. A PERIOD OF WINDY
CONDITIONS WILL ACCOMPANY A COLD FRONTAL PASSAGE WEDNESDAY NIGHT
INTO THURSDAY. WE HAVE HIGH TEMPS THURSDAY FROM 20 ALONG THE
INTERNATIONAL BORDER TO THE MID TWENTIES ACROSS THE SOUTH. THESE
WILL LIKELY FALL THROUGH THE DAY AS STRONG COLD AIR ADVECTION
OCCURS.
NORTHERLY WINDS THURSDAY INTO FRIDAY WILL COMBINE WITH THE MUCH
COLDER AIR TO PRODUCE A PERIOD OF LAKE EFFECT SNOW SHOWERS ALONG
THE SOUTH SHORE...ESPECIALLY ASHLAND/IRON COUNTIES. THE POTENTIAL
FOR SIGNIFICANT SNOWFALL EXISTS THURSDAY INTO FRIDAY.
MOST AREAS LOOK TO BE DRY FRIDAY INTO THE WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1204 PM CST SUN JAN 12 2014
MAIN AREA OF FREEZING RAIN IS NOW MOSTLY EAST OF THE
TERMINALS...THOUGH EXPECT THAT KDLH AND KHIB MAY STILL GET SOME
SHOWERS FOR A COUPLE MORE HOURS...BUT ONLY WITH MVFR CONDITIONS IN
THE SHOWERS. KHIB STILL IN MVFR...BUT EXPECT THEM TO GO VFR BY
20Z. REMAINDER OF TAF SITES TO REMAIN VFR THROUGH THE AFTERNOON
AND EVENING. AFTER 05Z AN AREA OF STRATUS TO PUSH INTO THE AREA
FROM THE NORTHWEST...BRINGING MVFR STRATUS 15HFT-25HFT. SCATTERED
SNOW SHOWERS EXPECTED WITH THIS STRATUS...BUT TIMING AND LOCATION
UNCERTAIN SO HAVE VCSH FOR NOW.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 33 16 19 6 / 70 10 10 30
INL 34 7 11 -4 / 60 30 20 10
BRD 37 15 18 10 / 70 10 10 70
HYR 35 21 23 8 / 50 10 20 70
ASX 34 21 23 8 / 60 10 10 50
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR MNZ010-011-018-
019-025-026-033>038.
WINTER WEATHER ADVISORY UNTIL 2 PM CST THIS AFTERNOON FOR MNZ012-
020-021.
WI...WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR WIZ001>003-
006>008.
LS...NONE.
&&
$$
UPDATE...LE
SHORT TERM...GROCHOCINSKI
LONG TERM...MELDE
AVIATION...LE
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1011 AM CST SUN JAN 12 2014
.UPDATE...
ISSUED AT 1011 AM CST SUN JAN 12 2014
MAIN UPPER LEVEL WAVE AXIS AND EFFECTIVE SURFACE WARM FRONT LIE
JUST TO THE WEST OF THE DULUTH CWA AS OF 10 AM..WITH MODERATE TO
STRONG FORCING FOR ASCENT PERSISTING ACROSS MUCH OF THE DULUTH
CWA. IT TOOK A BIT LONGER FOR THE FORCING TO ATTAIN DEEP LAYER
SATURATION THAN THE MODEL GUIDANCE FROM YDAY INDICATED..BUT ONCE
SATURATION WAS ACHIEVED..WE EXPERIENCED A RATHER EXPLOSIVE INCREASE
IN AREAL COVERAGE OF RADAR ECHOES BETWEEN 8-9 AM OVER PRETTY MUCH
THE ENTIRE EASTERN HALF OF THE DULUTH CWA.
PTYPE HAS STILL BEEN A HEADACHE. WITH RAPID NEWD ADVECTION OF
STRONG WARM NOSE ALOFT..PRECIP HAS BEEN ALMOST ALL FREEZING RAIN
SOUTH/WEST OF A LINE ROUGHLY FROM VOYAGEURS N.P. TO SILVER BAY.
HOWEVER..PRECIP IS STARTING AS SNOW OR A WINTRY MIX OVER THE
ARROWHEAD..BUT SHUD TRANSITION TO MORE SLEET/FZRA THERE BY EARLY
AFTERNOON..ALTHOUGH IT MAY BE A BIT HARDER TO WARM THE LOWER PART
OF THE TEMP PROFILE NOW THAT IT IS SATURATED OVER THE ARROWHEAD.
THE MAIN CHANGES FOR THE MORNING UPDATE THAT WAS MADE AVAILABLE
ABOUT 45 MINUTES AGO WERE TO 1) DRASTICALLY INCREASE POPS TO
ACCOUNT FOR WIDESPREAD PRECIP COVERAGE THRU EARLY AFTERNOON 2)
TWEAK PTYPE IN LINE WITH OBS AND SHORT RANGE GUIDANCE 3) INCREASE
SKY COVER TO NEAR 100 PERCENT AND 4) LOWER TEMPS..ESP OVER THE
NORTHEAST HALF OF THE CWA. NO CHANGES WERE MADE TO THE ADVISORY AT
THIS TIME. ADDITIONAL LIGHT PRECIP MAY REDEVELOP ALONG THE WESTERN
EDGE OF THE DULUTH CWA WHERE FORCING FOR ASCENT IS STILL
OCCURRING..BUT TEMPS SHOULD BE PUSHING THE FREEZING POINT OUT WEST
BY MIDDAY AS THE SURFACE WARM FRONT MAKES SLOW EASTWARD PROGRESS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 343 AM CST SUN JAN 12 2014
THIS WAS A CHALLENGING SHORT TERM FORECAST. THE MAIN FOCUS IS ON
THE POTENTIAL FOR FREEZING RAIN AND A WINTRY MIXTURE OF PCPN THIS
MORNING WITH A WARM FRONT IN THE NORTHERN PLAINS EARLY THIS
MORNING THAT WILL MOVE THROUGH THE NORTHLAND TODAY. THIS WARM
FRONT WILL BE ASSOCIATED WITH A LOW PRESSURE SYSTEM MOVING EAST
ACROSS SOUTH CENTRAL CANADA. THE MODEL SOUNDINGS CONTINUE TO
INDICATE A SHORT PERIOD WHERE SNOW ALOFT WILL FALL INTO A
RELATIVELY WARM LAYER ABOVE FREEZING (AROUND 1 TO 4 DEGREES
CELSIUS)...RESULTING IN FREEZING RAIN AND/OR SLEET AS IT FALLS TO
THE COLD SURFACE...WHICH IS BELOW FREEZING THIS MORNING.
THE CHALLENGING PART THOUGH IS THAT THERE ARE STILL SIGNIFICANT
DIFFERENCES BETWEEN THE MODELS AS TO THE TRACK AND PCPN AMOUNTS
TODAY. I WAS HOPING FOR BETTER MODEL AGREEMENT BY NOW COMPARED TO
MY PREVIOUS SHIFT. THE GFS/GEM/ECMWF/RAP13/HRRR PRIMARILY BRING
THE PCPN THROUGH NE MINNESOTA. ON THE OTHER HAND...THE NAM/WRF/GEM
REGIONAL WERE PRIMARILY BRINGING THE PCPN THROUGH THE INTERSTATE
35 CORRIDOR AND NW WISCONSIN. THE GFS IS MUCH MORE AGGRESSIVE WITH
THE PCPN THAN MOST OF THE OTHER MODELS...AND THE 06Z NAM12 CAME IN
WITH NO PCPN. THIS IS QUITE THE RANGE OF DIFFERENCES. IT APPEARS
THE RAP13 AND HRRR MIGHT BE DOING FAIRLY WELL WITH THE CURRENT
PCPN IN THE NORTHERN PLAINS AT THIS POINT...SO I LEANING ON NE
MINNESOTA BEING THE MOST AFFECTED. HOWEVER...I EXPANDED THE
FREEZING RAIN ACCUMULATION AND WINTER WEATHER ADVISORY TO MUCH OF
NW WISCONSIN SINCE THIS AREA COULD EASILY GET A LIGHT COATING OF
ICE TO MAKE FOR DIFFICULT TRAVEL CONDITIONS.
I EXPECT MUCH OF NE MINNESOTA AND NW WISCONSIN TO GET A LIGHT
COATING OF ICE...AROUND A COUPLE HUNDREDTHS OF AN INCH...THIS
MORNING. SOME ISOLATED LOCATIONS COULD GET UP TO AROUND 5
HUNDREDTHS OF AN INCH DEPENDING ON ANY MORE INTENSE SHOWER BANDS
THAT SET UP. THIS WILL LIKELY CAUSE DIFFICULT TRAVEL CONDITIONS
THIS MORNING UNTIL CONDITIONS BEGIN TO IMPROVE THIS AFTERNOON WITH
THE WARMING TEMPERATURES AND AS THE PCPN BEGINS TO EXIT THE
NORTHLAND.
THE MODEL AND MOS GUIDANCE IS IN PRETTY GOOD AGREEMENT WITH HIGH
TEMPERATURES TODAY WITH WIDESPREAD HIGHS IN THE MID 30S. THE
ARROWHEAD WILL MORE LIKELY REACH THE LOW 30S...WHILE THE BRAINERD
LAKES AREA MORE IN THE UPPER 30S. THERE WILL LIKELY BE SOME
PARTIAL CLEARING THIS AFTERNOON IN THE WAKE OF THE WARM FRONT.
TONIGHT...THE CANADIAN LOW PRESSURE WILL MOVE INTO CENTRAL
ONTARIO...AND ITS COLD FRONT WILL MOVE THROUGH THE NORTHLAND. THIS
WILL BRING COLDER TEMPERATURES WITH LOWS DIPPING DOWN TO THE TEENS
AND SINGLE DIGITS ACROSS NE MINNESOTA. THERE COULD BE LIGHT SNOW
WITH LITTLE TO NO ACCUMULATION ACROSS MUCH OF NE MINNESOTA.
MONDAY...HIGH TEMPERATURES WILL BE SIGNIFICANTLY COLDER THAN TODAY
WITH HIGHS IN THE TEENS AND LOW 20S. THERE MIGHT BE LINGERING
LIGHT SNOW IN THE MORNING...AND THEN A WEAK RIDGE OF HIGH PRESSURE
IN THE NORTHERN PLAINS WILL SHIFT INTO THE NORTHLAND DURING THE
AFTERNOON. THIS COULD BRING SOME PARTIAL CLEARING DURING THE
AFTERNOON...BUT I LEANED ON THE CLOUDIER SIDE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 343 AM CST SUN JAN 12 2014
A SERIES OF DISTURBANCES WILL IMPACT THE NORTHLAND THROUGH THE
EXTENDED PERIOD.
A CLIPPER WILL MOVE SOUTHEAST THROUGH THE AREA MONDAY NIGHT INTO
TUESDAY MORNING BRINGING THE POTENTIAL FOR A COUPLE INCHES OF SNOW
TO ABOUT THE SOUTHERN HALF/THIRD OF THE NORTHLAND. THE MODELS ARE
IN BETTER AGREEMENT TONIGHT THAN 24 HOURS AGO...BUT DIFFERENCES
REMAIN. THE ECMWF/GFS ARE FURTHER NORTH WITH THE TRACK OF THE LOW
AND WITH THE PRECIP...BUT THE LATEST NAM HAS TRENDED A BIT FURTHER
SOUTH. WE RAISED POPS TO LIKELY OVER OUR FAR SOUTHERN
ZONES...WHERE THE BEST CHANCE FOR 1 TO 2 INCHES OF SNOW EXISTS.
SOME HIGHER SNOWFALL AMOUNTS WILL ALSO BE POSSIBLE IN THE SNOWBELT
OF ASHLAND/IRON COUNTIES MONDAY NIGHT INTO TUESDAY DUE TO COLDER
AIR MOVING OVER THE LAKE ON NORTHWEST LOW LEVEL FLOW.
MOST AREAS WILL BE DRY TUESDAY AFTERNOON INTO TUESDAY NIGHT AS A
RIDGE MOVES OVER THE REGION. LAKE EFFECT SNOW WILL CONTINUE TO
BE POSSIBLE OVER PORTIONS OF THE SNOWBELT OF ASHLAND/IRON
COUNTIES.
A STRONGER SYSTEM WILL START TO IMPACT THE NORTHLAND WEDNESDAY. A
SURFACE LOW WILL TRACK FROM MANITOBA WEDNESDAY EVENING SOUTHEAST
TOWARD EASTERN LAKE SUPERIOR/NORTHERN MICHIGAN BY THURSDAY
EVENING. A STRONG AREA OF WAA WILL OCCUR AHEAD OF THE LOW
WEDNESDAY...BRINGING A CHANCE FOR PRECIPITATION TO MUCH OF THE
NORTHLAND BY WEDNESDAY AFTERNOON OR WEDNESDAY NIGHT. WE RAISED
POPS WEDNESDAY INTO WEDNESDAY NIGHT FOR MOST AREAS...AS A PERIOD
OF PRECIPITATION IS LOOKING MORE LIKELY. AT THIS TIME...WE HAVE
HIGHEST POPS OVER NORTHERN MINNESOTA. THE SYSTEM DOES NOT LOOK
QUITE AS WARM AS EARLIER MODEL RUNS...BUT WE DID KEEP A MENTION OF
FREEZING RAIN OVER PORTIONS OF OUR SOUTHERN AREA WEDNESDAY
AFTERNOON. LIGHT TO MODERATE SNOW ACCUMULATIONS WILL BE POSSIBLE
FROM WEDNESDAY AFTERNOON INTO THURSDAY. A PERIOD OF WINDY
CONDITIONS WILL ACCOMPANY A COLD FRONTAL PASSAGE WEDNESDAY NIGHT
INTO THURSDAY. WE HAVE HIGH TEMPS THURSDAY FROM 20 ALONG THE
INTERNATIONAL BORDER TO THE MID TWENTIES ACROSS THE SOUTH. THESE
WILL LIKELY FALL THROUGH THE DAY AS STRONG COLD AIR ADVECTION
OCCURS.
NORTHERLY WINDS THURSDAY INTO FRIDAY WILL COMBINE WITH THE MUCH
COLDER AIR TO PRODUCE A PERIOD OF LAKE EFFECT SNOW SHOWERS ALONG
THE SOUTH SHORE...ESPECIALLY ASHLAND/IRON COUNTIES. THE POTENTIAL
FOR SIGNIFICANT SNOWFALL EXISTS THURSDAY INTO FRIDAY.
MOST AREAS LOOK TO BE DRY FRIDAY INTO THE WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 616 AM CST SUN JAN 12 2014
MAINLY VFR CONDITIONS COVERED THE NORTHLAND EARLY THIS
MORNING...WITH IFR CEILINGS OVER THE ARROWHEAD DOWN INTO THE TWIN
PORTS...AND AROUND KPBH TO KD25. PRECIP COVERAGE IS LIMITED SO FAR
THIS MORNING...CLOSER TO WHAT THE NAM WAS DEPICTING. WE HAVE A
TEMPO GROUP FOR MOST TAF SITES FOR SOME FZRA/PL THIS MORNING. THE
LATEST RAP SUGGESTS MVFR OR IFR CEILINGS WILL REDEVELOP THROUGH THE
DAY TODAY...BUT CONFIDENCE IS LOW ON WHETHER OR NOT THAT WILL
MATERIALIZE. A COLD FRONT WILL MOVE THROUGH THE NORTHLAND TONIGHT
CAUSING WINDS TO TURN W TO NW. A BETTER CHANCE FOR MVFR CEILINGS
WILL OCCUR LATER TONIGHT WITH STRONGER CAA BEHIND THE FRONT. SOME
LIGHT SNOW OR FLURRIES MAY ALSO OCCUR TONIGHT...MAINLY AFFECTING
KHIB/KINL.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 32 16 19 6 / 70 10 10 30
INL 35 7 11 -4 / 60 30 20 10
BRD 37 15 18 10 / 70 10 10 70
HYR 35 21 23 8 / 50 10 20 70
ASX 33 21 23 8 / 60 10 10 50
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR MNZ010-011-018-
019-025-026-033>038.
WINTER WEATHER ADVISORY UNTIL 2 PM CST THIS AFTERNOON FOR MNZ012-
020-021.
WI...WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR WIZ001>003-
006>008.
LS...NONE.
&&
$$
UPDATE...MILLER
SHORT TERM...GROCHOCINSKI
LONG TERM...MELDE
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS NORMAN OK
1136 AM CST SUN JAN 12 2014
.DISCUSSION...
AVIATION DISCUSSION FOR THE 18Z TAFS IS BELOW.
&&
.AVIATION...
VFR CONDITIONS ARE EXPECTED TO CONTINUE. THE MAIN CONCERN
IS STRONG WINDS MAINLY BEFORE 00Z. NO SIGNIFICANT CHANGES
WERE MADE TO THE TAFS.
THE STRONGEST WINDS WILL REMAIN SOUTHEAST OF KEND-KCDS
THROUGH 00Z WITH A FEW GUSTS NEAR 40 KT. NON CONVECTIVE
LOW LEVEL WIND MAY BE OCCURRING IN THESE LOCATIONS
SOUTHEAST OF KEND-KCDS...BUT DID NOT MENTION DUE TO
LOW CONFIDENCE AS STRONGER WINDS 1000-2000 FT AGL
APPEAR TO BE MIXING DOWN TO THE GROUND.
A COLD FRONT WILL MOVE SOUTHEAST AND THROUGH ALL SITES
21-05Z. THINK FRONTAL PASSAGE WILL BE NEAR 02-04Z AT
KOKC...KLAW...AND KSPS. A WIND SHIFT TO THE NORTH AND
NORTHWEST WILL OCCUR WITH THE FRONT.
MBS
&&
.PREV DISCUSSION... /ISSUED 1046 AM CST SUN JAN 12 2014/
DISCUSSION...
A MILD AND WINDY DAY IS IN PROGRESS ACROSS THE SOUTHERN PLAINS.
FIRE WEATHER REMAINS THE MAIN CONCERN...AS RELATIVE HUMIDITY
VALUES CONTINUE TO PLUMMET. WE EXPECT THE HUMIDITY TO DROP BELOW
20 PERCENT ACROSS MOST OF WESTERN OKLAHOMA AND WESTERN NORTH TEXAS
BY MID-AFTERNOON...WHILE TEMPERATURES CLIMB INTO THE 70S OVER THIS
SAME AREA. MEANWHILE...THE SOUTHWEST WINDS WILL CONTINUE WITH
LITTLE CHANGE THIS AFTERNOON...OTHER THAN PERHAPS A SLIGHT
DECREASE IN THE NORTHWEST PARTS OF OKLAHOMA...WHERE THE PROXIMITY
OF THE FRONT WILL REDUCE THE PRESSURE GRADIENT SLIGHTLY.
THE LATEST SHORT-TERM MODEL GUIDANCE AND ACTUAL OBSERVATIONS
GENERALLY SUPPORT OUR CURRENT FORECAST WITH NO SIGNIFICANT
CHANGES. SO...NO UPDATE IS PLANNED FOR THIS MORNING.
PREV DISCUSSION... /ISSUED 546 AM CST SUN JAN 12 2014/
AVIATION...
12/12Z TAFS...VFR CONDITIONS WILL PREVAIL. LLWS WILL BE SEEN FIRST
3 OR 4 HOURS ACROSS ALL BUT NORTHWEST OKLAHOMA TERMINALS. STRONG
SOUTHWEST WINDS WILL OCCUR AHEAD OF COLD FRONT. FROPA EXPECTED
NORTHWEST OKLAHOMA TERMINALS AROUND 22Z WITH SOUTHWARD PROGRESSION
CLEARING ALL TERMINALS BY 13/04Z.
PREV DISCUSSION... /ISSUED 422 AM CST SUN JAN 12 2014/
DISCUSSION...
VERY WARM...DRY...AND WINDY CONDITIONS ACROSS THE REGION TODAY. WE
WENT WITH THE RAP MODEL FOR SHORT-TERM FORECAST SOLUTION WHICH
SPREADS RED FLAG WILDFIRE CONDITIONS ACROSS A LARGE PART OF
WESTERN OKLAHOMA AND WESTERN NORTH TEXAS. THIS SOLUTION IS MUCH
DRIER THAN OTHER GUIDANCE AND WILL LIKELY BE CLOSER TO VERIFYING
GIVEN STRONG DOWNSLOPE COMPONENT TO FLOW AND UPSTREAM DRY AIR ON
REGIONAL SOUNDINGS. THERE VERY WELL COULD BE FAIRLY TIGHT MOISTURE
GRADIENT LATE TODAY JUST EAST OF INTERSTATE-44 CORRIDOR. THIS WILL
BE WATCHED CLOSELY...AND IF NEED BE...ADJUSTMENTS TO CURRENT RED
FLAG WARNING WILL BE MADE. ALTHOUGH IT WILL BE WINDY AND WARM
ACROSS CENTRAL AND SOUTHERN PARTS OF OKLAHOMA... WHICH WILL STILL
CREATE WILDFIRE CONCERNS...CURRENT HUMIDITY FORECAST EXPECTED TO
KEEP OKC AND POINTS SOUTH AND EAST OUTSIDE OF RED FLAG CRITERIA.
WITH ALL OF THAT BEING TYPED...OUTDOOR BURNING AND OTHER ACTIVITIES
THAT COULD LEAD TO WILDFIRES IS DISCOURAGED ACROSS ALL OF OKLAHOMA
AND WESTERN NORTH TEXAS. THERE ARE BURN BANS IN EFFECT ACROSS
NORTH TEXAS.
COLD FRONT WILL MOVE INTO NORTHERN OKLAHOMA MID-LATE
AFTERNOON...WHICH WILL EFFECTIVELY WEAKEN THE PRESSURE GRADIENT
AND ALLOW WINDS TO DECREASE. ALTHOUGH THEY COULD SEE WIND ADVISORY
WORTHY WINDS BRIEFLY LATE THIS MORNING OR EARLY AFTERNOON...THEY
WERE LEFT OUT OF WIND ADVISORY. THIS FRONT WILL BRING IN MUCH
COLDER AIR...WHEN COMPARED TO WHAT WE WILL SEE TODAY. WITH
NUMEROUS COLD FRONTS PASSING OVER THE REGION THROUGH THE WEEK...
TEMPERATURES ARE EXPECTED TO REMAIN NEAR OR SLIGHTLY ABOVE AVERAGE
FOR THE MOST PART. DRY WEATHER EXPECTED.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 70 34 60 32 / 0 10 0 0
HOBART OK 73 32 59 29 / 0 10 0 0
WICHITA FALLS TX 76 35 63 32 / 0 10 0 0
GAGE OK 69 29 59 26 / 0 10 0 0
PONCA CITY OK 67 31 59 31 / 0 10 0 0
DURANT OK 70 42 62 36 / 0 10 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR OKZ013-016>047-050-
051.
RED FLAG WARNING UNTIL 6 PM CST THIS EVENING FOR OKZ014-016-
021>023-027-033>039-044-045.
TX...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR TXZ083>090.
RED FLAG WARNING UNTIL 6 PM CST THIS EVENING FOR TXZ083>090.
&&
$$
23/17/17
AREA FORECAST DISCUSSION
NWS NORMAN OK
1046 AM CST SUN JAN 12 2014
.DISCUSSION...
A MILD AND WINDY DAY IS IN PROGRESS ACROSS THE SOUTHERN PLAINS.
FIRE WEATHER REMAINS THE MAIN CONCERN...AS RELATIVE HUMIDITY
VALUES CONTINUE TO PLUMMET. WE EXPECT THE HUMIDITY TO DROP BELOW
20 PERCENT ACROSS MOST OF WESTERN OKLAHOMA AND WESTERN NORTH TEXAS
BY MID-AFTERNOON...WHILE TEMPERATURES CLIMB INTO THE 70S OVER THIS
SAME AREA. MEANWHILE...THE SOUTHWEST WINDS WILL CONTINUE WITH
LITTLE CHANGE THIS AFTERNOON...OTHER THAN PERHAPS A SLIGHT
DECREASE IN THE NORTHWEST PARTS OF OKLAHOMA...WHERE THE PROXIMITY
OF THE FRONT WILL REDUCE THE PRESSURE GRADIENT SLIGHTLY.
THE LATEST SHORT-TERM MODEL GUIDANCE AND ACTUAL OBSERVATIONS
GENERALLY SUPPORT OUR CURRENT FORECAST WITH NO SIGNIFICANT
CHANGES. SO...NO UPDATE IS PLANNED FOR THIS MORNING.
&&
.PREV DISCUSSION... /ISSUED 546 AM CST SUN JAN 12 2014/
AVIATION...
12/12Z TAFS...VFR CONDITIONS WILL PREVAIL. LLWS WILL BE SEEN FIRST
3 OR 4 HOURS ACROSS ALL BUT NORTHWEST OKLAHOMA TERMINALS. STRONG
SOUTHWEST WINDS WILL OCCUR AHEAD OF COLD FRONT. FROPA EXPECTED
NORTHWEST OKLAHOMA TERMINALS AROUND 22Z WITH SOUTHWARD PROGRESSION
CLEARING ALL TERMINALS BY 13/04Z.
PREV DISCUSSION... /ISSUED 422 AM CST SUN JAN 12 2014/
DISCUSSION...
VERY WARM...DRY...AND WINDY CONDITIONS ACROSS THE REGION TODAY. WE
WENT WITH THE RAP MODEL FOR SHORT-TERM FORECAST SOLUTION WHICH
SPREADS RED FLAG WILDFIRE CONDITIONS ACROSS A LARGE PART OF
WESTERN OKLAHOMA AND WESTERN NORTH TEXAS. THIS SOLUTION IS MUCH
DRIER THAN OTHER GUIDANCE AND WILL LIKELY BE CLOSER TO VERIFYING
GIVEN STRONG DOWNSLOPE COMPONENT TO FLOW AND UPSTREAM DRY AIR ON
REGIONAL SOUNDINGS. THERE VERY WELL COULD BE FAIRLY TIGHT MOISTURE
GRADIENT LATE TODAY JUST EAST OF INTERSTATE-44 CORRIDOR. THIS WILL
BE WATCHED CLOSELY...AND IF NEED BE...ADJUSTMENTS TO CURRENT RED
FLAG WARNING WILL BE MADE. ALTHOUGH IT WILL BE WINDY AND WARM
ACROSS CENTRAL AND SOUTHERN PARTS OF OKLAHOMA... WHICH WILL STILL
CREATE WILDFIRE CONCERNS...CURRENT HUMIDITY FORECAST EXPECTED TO
KEEP OKC AND POINTS SOUTH AND EAST OUTSIDE OF RED FLAG CRITERIA.
WITH ALL OF THAT BEING TYPED...OUTDOOR BURNING AND OTHER ACTIVITIES
THAT COULD LEAD TO WILDFIRES IS DISCOURAGED ACROSS ALL OF OKLAHOMA
AND WESTERN NORTH TEXAS. THERE ARE BURN BANS IN EFFECT ACROSS
NORTH TEXAS.
COLD FRONT WILL MOVE INTO NORTHERN OKLAHOMA MID-LATE
AFTERNOON...WHICH WILL EFFECTIVELY WEAKEN THE PRESSURE GRADIENT
AND ALLOW WINDS TO DECREASE. ALTHOUGH THEY COULD SEE WIND ADVISORY
WORTHY WINDS BRIEFLY LATE THIS MORNING OR EARLY AFTERNOON...THEY
WERE LEFT OUT OF WIND ADVISORY. THIS FRONT WILL BRING IN MUCH
COLDER AIR...WHEN COMPARED TO WHAT WE WILL SEE TODAY. WITH
NUMEROUS COLD FRONTS PASSING OVER THE REGION THROUGH THE WEEK...
TEMPERATURES ARE EXPECTED TO REMAIN NEAR OR SLIGHTLY ABOVE AVERAGE
FOR THE MOST PART. DRY WEATHER EXPECTED.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 70 34 60 32 / 0 10 0 0
HOBART OK 73 32 59 29 / 0 10 0 0
WICHITA FALLS TX 76 35 63 32 / 0 10 0 0
GAGE OK 69 29 59 26 / 0 10 0 0
PONCA CITY OK 67 31 59 31 / 0 10 0 0
DURANT OK 70 42 62 36 / 0 10 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR OKZ013-016>047-050-
051.
RED FLAG WARNING UNTIL 6 PM CST THIS EVENING FOR OKZ014-016-
021>023-027-033>039-044-045.
TX...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR TXZ083>090.
RED FLAG WARNING UNTIL 6 PM CST THIS EVENING FOR TXZ083>090.
&&
$$
23/17
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
322 PM CST SUN JAN 12 2014
.SHORT TERM...(TONIGHT THROUGH MONDAY)
ISSUED AT 322 PM CST SUN JAN 12 2014
THE UPPER MISSISSIPPI RIVER VALLEY REGION WAS ENJOYING THE WARM
SECTOR OF A 983MB AREA OF LOW PRESSURE MOVING THROUGH WESTERN
ONTARIO. AT 3 PM...TEMPERATURES ACROSS THE AREA RANGED FROM THE
MIDDLE 30S ACROSS NORTH CENTRAL WISCONSIN...TO THE UPPER 30S AND
EVEN A FEW LOWER 40S ACROSS THE REST OF THE FORECAST AREA.
AS THE LOW CONTINUES TO MOVE THROUGH ONTARIO...IT WILL DRAG A COLD
FRONT SLOWLY SOUTHEASTWARD ACROSS THE AREA. RAP SHOWING SOME FAIRLY
STRONG 700-500MB FRONTOGENESIS AND RIGHT ENTRANCE REGION OF 300MB
JET MOVING ACROSS THE AREA THIS EVENING FOR A CHANCE OF RAIN. WITH
TEMPERATURES REMAINING IN THE MIDDLE 30S FOR THE MOST PART THROUGH
THE EVENING...THREAT OF ANY FREEZING RAIN LOOKS MINIMAL. THE
EXCEPTIONS WILL BE LOWER-LYING COLD POCKET AREAS WITH UNTREATED
ROADWAYS. THINK THE HIGHEST THREAT AREA FOR THIS HAPPENING WILL BE
IN THE CRANBERRY BOG AREAS OF CENTRAL WI WHERE IT TYPICALLY GETS
COLDER QUICKER. AS THE SURFACE COLD FRONT CONTINUES TO MOVE THROUGH
THE AREA AFTER MIDNIGHT...APPEARS THE CHANCE OF A RAIN/FREEZING
SHIFTS MAINLY SOUTHEAST OF A LINE FROM MAUSTON TO BOSCOBEL WI LINE.
KEEPING POPS IN THE CHANCE CATEGORY SINCE BUFKIT IS STILL SHOWING
SOME SATURATION ISSUES THROUGH THE COLUMN. WILL CONTINUE TO MONITOR
THIS SITUATION...BUT NOT THINKING ANY WINTER HEADLINES NEEDED AT
THIS TIME. OTHERWISE...LOOK FOR OVERNIGHT LOWS IN THE 25-30 DEGREE
RANGE BY 6AM.
COLD AIR ADVECTION WILL BE IN PLACE ACROSS THE AREA ON MONDAY ALONG
WITH CYCLONIC FLOW ALOFT. THINKING THIS WILL GIVE US A MIXED BAG OF
CLOUD COVER WITH STEEPER LAPSE RATE TYPE STRATOCUMULUS AND THEN
INCREASING MID CLOUD LATE IN THE AFTERNOON AHEAD LOW PRESSURE AND A
WARM FRONT MOVING INTO THE DAKOTAS/WESTERN MN. HIGHS MONDAY EXPECTED
TO CLIMB ONLY A COUPLE DEGREES FROM THE OVERNIGHT LOWS...TOPPING OFF
IN THE MIDDLE 20S TO THE LOWER 30S.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 322 PM CST SUN JAN 12 2014
12.12Z MODELS VERY CONSISTENT IN BRINGING A VIGOROUS MID-LEVEL
TROUGH AND SURFACE LOW ACROSS THE AREA MONDAY NIGHT THROUGH TUESDAY.
MODELS PRETTY MUCH LOCKING ONTO A COMMON SOLUTION...BRINGING THE
HEAVIEST SNOW THROUGH THE I-90/94 CORRIDOR AREAS. THE NAM IS THE
HIGHEST WITH ITS SNOW AMOUNTS RANGING FROM 2-5 INCHES WHILE THE
ECMFW IS INDICATING 1-3 INCHES. THE GFS COMES IN AT 1-4 INCHES. SREF
IS RIGHT IN THE MIDDLE WITH 1-4 INCHES. ALSO LOOKS LIKE THERE WILL
BE THE POTENTIAL FOR SOME BLOWING SNOW ACROSS THE OPEN PORTIONS OF
NORTHEAST IA AND SOUTHEAST MN TUESDAY AFTERNOON AS GUSTY NORTHWEST
WINDS SPREAD IN BEHIND THE SURFACE LOW. DUE TO THE GIVEN SNOWFALL
AMOUNTS AND WIND/BLOWING SNOW ISSUES...A WINTER WEATHER ADVISORY
HEADLINE WILL EVENTUALLY BE NEEDED FOR THIS EVENT AND WILL LIKELY BE
HOISTED BY THE MIDSHIFT CREW TONIGHT. OTHERWISE...LOOK FOR
TEMPERATURES MONDAY NIGHT IN THE TEENS TO LOWER 20S...THEN CLIMBING
THROUGH THE 20S ON TUESDAY.
ANOTHER SHOT AT SOME SNOW WILL COME ALONG WEDNESDAY NIGHT AS LIFT
INCREASES AHEAD OF A WARM FRONT EXTENDING FROM A VIGOROUS LOW
PASSING ACROSS SOUTHERN CANADA. SNOW CHANCES WILL CONTINUE INTO
THURSDAY WITH COLDER/UNSTABLE CYCLONIC FLOW ENTERING THE REGION.
ANOTHER TROUGH WILL DROP INTO THE REGION THURSDAY NIGHT FOR A
CONTINUED CHANCE OF LIGHT SNOW MAINLY EAST OF THE MISSISSIPPI RIVER.
EXPECT LOWS WEDNESDAY NIGHT IN THE TEENS WITH HIGHS ON THURSDAY
WARMING INTO THE 25 TO 32 DEGREE RANGE. COLDER AIR FILTERING INTO
THE AREA THURSDAY NIGHT WILL PRODUCE LOWS IN THE SINGLE DIGITS ABOVE
AND BELOW ZERO.
FRIDAY THROUGH THE WEEKEND LOOKS QUIET WEATHER-WISE AS A MID/UPPER
RIDGE OF HIGH PRESSURE BUILDS IN FROM THE PLAINS. LOOK FOR HIGHS
STARTING OUT COLD IN THE 10-15 DEGREE RANGE FRIDAY...MODERATING INTO
THE 20S SATURDAY AND SUNDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1200 PM CST SUN JAN 12 2014
PASSAGE OF SHORT TERM UPPER RIDGE TODAY ACTUALLY WILL BRING IN
SOUTHWEST FLOW AHEAD OF APPROACHING SHORT WAVE TROUGHS. FAIRLY
DECENT LIFT IN WARM AIR ADVECTION ZONE MAY STILL TAKE AWHILE TO
SATURATE DRY LOWER LEVELS BUT SHORT TERM GUIDANCE STILL SUGGESTING
THIS COULD LEAD TO SOME LIGHT PRECIPITATION LATE TODAY. CONFIDENCE
IN THIS IS ONLY MARGINAL WITH CEILINGS EXPECTED TO REMAIN IN VFR
RANGE. PRESSURE GRADIENT SHOULD ALSO LOOSEN THIS AFTERNOON SO GUSTY
WINDS MAY HAVE ALREADY BEEN AT PEAK.
AS FIRST SHORT WAVE BRINGS COLD FRONT IN OVERNIGHT...COLD AIR
ADVECTION SCHEME SETS UP AND WITH NORTHWEST WINDS...COULD BRING IN
PERIOD OF MVFR TO PATCHY IFR CONDITIONS MONDAY MORNING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM...DAS
AVIATION...SHEA