Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 01/02/15
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
910 AM MST WED DEC 31 2014
&&
...MAJOR WINTER STORM WILL IMPACT CALIFORNIA AND ARIZONA TODAY AND
EARLY THURSDAY...
.SYNOPSIS...
A MAJOR WINTER STORM SYSTEM WILL AFFECT THE REGION TODAY AND EARLY
THURSDAY WITH WIDESPREAD DESERT RAIN AND MOUNTAIN SNOW. SNOW LEVELS
WILL FALL TO AS LOW AS 2000 FT FOR A PERIOD...WITH SUBSTANTIAL
SNOWFALL ACCUMULATIONS OVER MOUNTAINOUS TERRAIN. COOLER BUT DRY
WEATHER WILL RETURN BY THE END OF THE WEEK THROUGH SATURDAY.
BUILDING HIGH PRESSURE WILL MOVE IN STARTING SUNDAY ALLOWING
TEMPERATURES TO WARM BACK TO NORMAL TO SLIGHTLY ABOVE NORMAL.
&&
.DISCUSSION...
A VERY COLD STORM...FOR OUR NECK-OF-THE-WOODS...CONTINUES TO MOVE
INTO THE REGION THIS MORNING. LATEST SATELLITE IMAGERY IS NOW
SHOWING THE MAIN UPPER LOW CENTER NOW MOVING INLAND INTO EXTREME
SOUTHERN SAN DIEGO COUNTY...WITH ACCUMULATING SNOW BEING REPORTED
DOWN TO AS LOW AS 1000FT ACROSS PARTS OF SOUTHERN CA EARLIER THIS
MORNING AS THIS SYSTEM MOVED THROUGH. THE 88D RADAR IS CURRENTLY
SHOWING RAIN...AND SNOW SHOWERS NOW BREAKING OUT OVER WESTERN
MARICOPA COUNTY AS DRIER...AND COLDER AIR THAT IS POURING DOWN THE
COLORADO RIVER VALLEY SPREADS EASTWARD ACROSS SW ARIZONA HELPS TO
LOWER SNOW LEVELS ACROSS THAT REGION...WITH SNOW ALREADY BEING
REPORTED ACROSS THE WICKENBURG AREA...AND SNOW EVEN NOW BEING
REPORTED IN LAKE HAVASU CITY AS WELL. BASED ON LATEST TRENDS AND
UPDATED HRRR HI-RES RUNS...HAVE LOWERED TEMPS ACROSS THE LOWER
ELEVATIONS OF OUR CWA...AND RAISED POPS FOR THIS AFTERNOON ACROSS
SOUTH-CENTRAL AZ.
&&
.PREVIOUS DISCUSSION...
THE MAJOR WINTER STORM IS NOW MAKING ITS WAY INTO OUR REGION WITH
RAIN AND SNOW CURRENTLY FALLING ACROSS MUCH OF SOUTHEAST CALIFORNIA.
THE UPPER LOW CENTER CURRENTLY CENTERED OVER SOUTHERN CALIFORNIA IS
STARTING TO MAKE SOME EASTWARD PROGRESS AND ITS FORWARD SPEED IS
EXPECTED TO SLOW DOWN OVER THE NEXT 12 HOURS AS THE UPPER TROUGH
BECOMES MORE NEUTRALLY TILTED. AN IMPRESSIVE 125KT UPPER JET CORE
SITUATED ACROSS NORTHERN ARIZONA INTO SOUTHERN COLORADO IS PROVIDING
STRONG VERTICAL LIFT ACROSS SOUTHEAST CALIFORNIA INTO CENTRAL
ARIZONA. EXPECTING RAPID SHOWER DEVELOPMENT OVER THE NEXT SIX HOURS
TO BREAK OUT OVER SOUTHWEST AND SOUTH-CENTRAL ARIZONA IN RESPONSE TO
THE INCREASING LIFT FROM THE SOUTHEASTWARD SHIFTING JET CORE AND
RAPID MOISTENING FROM COLD AIR ALOFT MOVING IN AND FROM A STREAM OF
LOW LEVEL MOISTURE ADVECTING IN ALONG THE SOUTHERN EDGE OF THE UPPER
TROUGH. ENHANCED LIFT FROM A STRONG PVA REGION NOW OVER SOUTHERN
CALIFORNIA WILL ALSO SHIFT EASTWARD INTO SOUTHWEST ARIZONA THROUGH
THE LATE MORNING HOURS AND THROUGH SOUTH-CENTRAL ARIZONA BY LATE
THIS AFTERNOON.
THE MAIN IMPACT FROM THIS STORM SYSTEM WILL BE THE POTENTIAL FOR
ACCUMULATING SNOWS ACROSS HIGHER TERRAIN LOCATIONS...ESPECIALLY
ACROSS CENTRAL AND EASTERN ARIZONA. SNOW LEVELS WILL RAPIDLY FALL
FROM WEST TO EAST TODAY INTO THE 2K-3K FOOT RANGE BY LATE TONIGHT.
THE INITIAL BAND OF PRECIPITATION THIS MORNING ACROSS SOUTH-CENTRAL
ARIZONA WILL MAINLY FALL AS RAIN ACROSS OUR CWA...BUT AS SNOW LEVELS
FALL THROUGHOUT THE DAY...RAIN WILL CHANGE TO SNOW ACROSS THE HIGHER
TERRAIN NORTH AND EAST OF PHOENIX. THE BULK OF THE ACCUMULATING
SNOWFALL WILL START LATE THIS AFTERNOON AND LAST INTO TONIGHT WITH
POSSIBLE ACCUMULATIONS OF 2 TO 6 INCHES ABOVE 3500 FEET AND 6 TO 10
INCHES ABOVE 5000 FEET. WINDS ARE EXPECTED TO BE FAIRLY LIGHT...SO
BLOWING AND DRIFTING OF SNOW SHOULD NOT BE MUCH OF A FACTOR...BUT AS
TEMPERATURES FALL BELOW FREEZING SOMETIME THIS EVENING...SOME
ROADWAYS WILL LIKELY BECOME SNOW COVERED. WILL KEEP THE WINTER STORM
WARNING STARTING 18Z TODAY IN PLACE WITH NO CHANGES FOR ELEVATIONS
ABOVE 3500 FEET FOR ZONE 24.
LATEST MODEL QPF AMOUNTS ARE BASICALLY RIGHT IN LINE WITH THE
PREVIOUS FORECAST AND NO SIGNIFICANT ADJUSTMENTS WERE NEEDED. WITH
FAIRLY LIMITED MOISTURE...MOST LOWER DESERT AREAS FAR REMOVED FROM
THE HIGH TERRAIN SHOULD ONLY SEE A FEW HUNDREDTHS TO UP TO A TENTH
OF AN INCH. HIGHER AMOUNTS...UP TO A QUARTER INCH...SHOULD FALL FROM
PHOENIX NORTHWARD DUE TO THE STRONG UPSLOPING NATURE OF THIS EVENT.
THE BULK OF THE RAIN WILL END EVEN BY LATE THIS AFTERNOON WITH SOME
LINGERING RAIN OR SNOW TO THE NORTH AND EAST OF PHOENIX INTO
TONIGHT. DRYING AND SUBSIDENCE ALOFT SHOULD OVERTAKE MUCH OF THE
LOWER DESERTS BY THIS EVENING...BUT LOW LEVEL SOUTHERLY WINDS WILL
CONTINUE SOME UPSLOPE PRECIPITATION TO THE NORTH AND EAST OF PHOENIX
THROUGH TONIGHT BEFORE TAPERING OFF SOMETIME THURSDAY.
ATTENTION THEN TURNS TO THE INCREASING LIKELIHOOD OF A WIDESPREAD
FREEZE EVENT ACROSS THE LOWER DESERTS STARTING TONIGHT AND POSSIBLY
LASTING THROUGH FRIDAY NIGHT. THERE IS SOME DOUBT AS TO HOW QUICKLY
SKIES WILL CLEAR OUT TONIGHT ACROSS PORTIONS OF SOUTH-CENTRAL
ARIZONA...BUT THERE IS ENOUGH CONFIDENCE TO ISSUE FREEZE WARNINGS
FOR ALL BUT THE PHOENIX ZONE. WILL STRESS THE NEAR FREEZING
CONDITIONS FOR PHOENIX...SOUTHEAST CALIFORNIA...AND YUMA IN AN SPS
FOR TONIGHT. THURSDAY NIGHT SHOULD END UP BEING THE COLDEST NIGHT
WITH WIDESPREAD CLEAR TO MOSTLY CLEAR SKIES...LIGHT WINDS...AND
850MB TEMPERATURES NEAR 0C. WILL CARRY THE FREEZE WARNING AGAIN FOR
THURSDAY NIGHT WHILE ALSO INCLUDING PHOENIX IN THE WARNING. FRIDAY
NIGHT MAY ALSO END UP NEEDING SOME HEADLINES FOR THE COLD
TEMPERATURES...BUT MODELS SUGGEST SOME WARMING BEGINNING BY
THEN...SO WILL HOLD OFF ISSUING ANY HEADLINES FOR NOW.
STARTING FRIDAY...MODELS ARE IN GOOD AGREEMENT SHIFTING THE UPPER
LOW EASTWARD OUT OF OUR REGION AND ALLOWING A GRADUAL INCREASE IN
UPPER HEIGHTS. THE HIGH AMPLITUDE RIDGE THAT HAS BEEN OVER THE
EASTERN PACIFIC THE PAST SEVERAL DAYS WILL BEGIN TO TILT EASTWARD
INTO THE DESERT SOUTHWEST BY EARLY NEXT WEEK. THERE IS SOME MODEL
DISAGREEMENT AT THIS POINT...BUT OVERALL LONG RANGE MODELS SUGGEST
INCREASED HEIGHTS WHICH POINTS TO A SUBSTANTIAL WARM-UP. HIGHS
SHOULD BOUNCE BACK TO NEAR NORMAL BY NEXT MONDAY AND POSSIBLY REACH
INTO THE LOWER 70S ACROSS THE LOWER DESERTS BY THE MIDDLE OF NEXT
WEEK. DRY CONDITIONS WILL BE THE RULE AFTER THURSDAY WITH NO
SIGNIFICANT LOW PRESSURE SYSTEMS THREATENING OUR REGION THROUGH THE
MIDDLE OF NEXT WEEK.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
A COLD FRONT APPROACHING. THROUGH 16Z WED...CIGS NEAR 5 THSD AGL...
SCT R SHWRS. FROM 16Z WED TO 21Z WED...CIGS LOWERING IN LIGHT
RAIN...BECOMING BKN-OVC 30-40 THSD AGL WITH SCT LOWER CLDS. LIGHT
SOUTHWEST WIND UNDER 8 KNOTS. FROM 21Z WED TO 03Z THU. DRIER AIR
MOVING IN BEHIND THE COLD FRONT. CIGS LIFTING TO BETWEEN 4 TO 6 THSD
AGL. ISOLD LIGHT SHWRS. LIGHT WEST WIND UNDER 8 KNOTS.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA...INCLUDING KIPL AND KBLH...
COLD FRONTAL PASSAGE. THROUGH 16Z WED...CIGS 4 TO 6 THSD AGL. SCT R
SHOWERS. NORTH TO NORTHWEST WIND 10 TO 15 KNOTS. BETWEEN 16Z WED AND
01Z THU...A DRIER AIR MOVING IN. CIGS LIFTING TO BETWEEN 6 AND 8
THSD AGL. ISOLD R SHWRS. NORTH WIND 10 TO 20 KNOTS. FROM 01Z THU TO
06Z THU...SCT CLDS NEAR 10 THSD AGL. NORTH WIND 5 TO 10 KNOTS.
.FIRE WEATHER...
FRIDAY THROUGH TUESDAY...
MOSTLY CLEAR SKIES AND MUCH BELOW NORMAL TEMPERATURES ARE EXPECTED
FRIDAY THROUGH SUNDAY...WARMING SOMEWHAT MONDAY AND TUESDAY. MINIMUM
RELATIVE HUMIDITIES FRIDAY WILL RANGE FROM 20 PERCENT IN SOUTHEAST
CALIFORNIA TO 50 PERCENT IN SOUTHERN GILA COUNTY...DECREASING MONDAY
AND TUESDAY BY 15 TO 20 PERCENT RANGE AREA-WIDE. LIGHT WIND.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...FREEZE WARNING FROM 11 PM THIS EVENING TO 9 AM MST THURSDAY
AZZ020>022-026>028.
FREEZE WARNING FROM 11 PM THURSDAY TO 9 AM MST FRIDAY
AZZ020>023-026>028.
WINTER STORM WARNING FROM 11 AM THIS MORNING TO 5 PM MST
THURSDAY ABOVE 3500 FEET FOR AZZ024.
CA...WINTER WEATHER ADVISORY UNTIL 4 PM PST THIS AFTERNOON ABOVE
2000 FEET FOR CAZ030.
&&
$$
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DISCUSSION...PERCHA/KUHLMAN
AVIATION....VASQUEZ
FIRE WEATHER...VASQUEZ
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
342 AM PST WED DEC 31 2014
...A COLD AND WINDY END TO 2014...
.SYNOPSIS...GUSTY NORTH TO NORTHEAST WINDS WILL CONTINUE THROUGH
MID MORNING BEFORE DIMINISHING TODAY. THE COLD AIRMASS IN PLACE
AND CLEAR SKIES WILL RESULT IN THE COLDEST TEMPERATURES OF THE
SEASON TONIGHT. TEMPERATURES GRADUALLY WARM LATE IN THE WEEK INTO
THE WEEKEND.
&&
.DISCUSSION...AS OF 3:30 AM PST WEDNESDAY...A DEEP UPPER LOW THAT
MOVED THROUGH THE AREA IS NOW CENTERED OVER SOUTHERN CALIFORNIA.
THE SURFACE LOW ALSO OVER SOUTHERN CALIFORNIA COMBINED WITH STRONG
HIGH PRESSURE OVER THE GREAT BASIN HAS RESULTED IN ROBUST PRESSURE
GRADIENTS DRIVING STRONG WINDS SINCE LATE MORNING YESTERDAY.
NUMEROUS DOWNED TREES WERE NOTED...SEE LOCAL STORM REPORT
SUMMARY...AND CAUSED THOUSANDS TO LOSE ELECTRICAL POWER.
THE WINDS HAVE SUBSIDED SOMEWHAT OVERNIGHT...PARTICULARLY OVER
LOWER ELEVATIONS AS VERTICAL MIXING HAS DECREASED...THOUGH WINDS
REMAIN GUSTY. SFO IS STILL GUSTING TO 31 MPH WHILE MT DIABLO
REPORTS A PEAK WIND OF 51 MPH IN THE LAST HOUR. THESE STRONGER
WINDS WILL CONTINUE TO DECREASE THROUGH THE MORNING AS THE LOW
CENTER CONTINUES TO MOVE SOUTH. WINDS HAVE KEPT THE ATMOSPHERE
MIXED OVERNIGHT PREVENTING VERY COLD TEMPERATURES FROM DEVELOPING
THOUGH THE BRISK WINDS ARE MAKING IT FEEL RATHER COLD.
AS WINDS DIMINISH TODAY...TEMPERATURES ARE FORECAST TO BE
ESPECIALLY COLD TONIGHT. THE COLD DRY AIRMASS COMBINED WITH CLEAR
SKIES PROMOTING RADIATIONAL COOLING WILL ALLOW TEMPERATURES TO
DROP BELOW FREEZING IN MANY INLAND AREAS AND INTO THE LOW TO MID
30S NEAR SF BAY.
THE AIRMASS GRADUALLY WARMS INTO THE END OF THE WEEK AS RIDGING
STARTS TO NUDGE INTO THE AREA FROM THE WEST. TEMPS WILL GRADUALLY
INCREASE THOUGH THE COLD DRY AIR WILL LIKELY STICK AROUND FOR
ANOTHER NIGHT. AS THE RIDGE CONTINUES TO BUILD INTO THE WEEKEND
TEMPS WILL RISE TO NEAR NORMAL THOUGH THE LONG CLEAR WINTER NIGHTS
WILL KEEP OVERNIGHT LOWS CHILLY.
DRY WEATHER WILL CONTINUE THROUGH THE FORECAST PERIOD. THE GLOBAL
MODELS POINT TO A SHORTWAVE IMPACTING THE AREA THE MIDDLE OF NEXT
WEEK. THE AFTERNOON RUN OF THE GFS HAS INCREASED THE INTENSITY OF
THIS STORM THOUGH IT APPEARS TO LACK A CONNECTION TO SUBTROPICAL
MOISTURE WITH A SIGNIFICANT BLOCKING PATTERN FURTHER WEST IN THE
PACIFIC.
&&
.AVIATION...AS OF 10 PM PST TUESDAY...AN ENERGETIC WINDSTORM WILL
CONTINUE TO BRING GUSTY NORTH WINDS WHILE DESCENDING INTO SOUTHERN
CALIFORNIA LATE THIS EVENING. AIRPORTS ACROSS THE REGION HAVE
REPORTED SIGNIFICANT DECLINES IN WIND SPEEDS WITH THE NOTABLE
EXCEPTION OF SFO... WHICH CONTINUES TO GUST TO AROUND 40KTS.
MODELS HAVE STRUGGLED WITH WIND SPEEDS AND TIMING SO FAR...
HOWEVER THE HRRR HAS BEEN CONSISTENT IN WEAKENING NEAR SURFACE
WINDS BY 07Z SINCE THIS AFTERNOON. WINDS AND GUSTS WILL DIMINISH
THROUGH THE NIGHT.
VICINITY OF KSFO...VFR. NORTH WINDS WILL REMAIN GUSTY THROUGH THE
NIGHT AT KSFO. STRONGEST WINDS SHOULD DIMINISH AFTER 07Z.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...VFR.
&&
.MARINE...AS OF 03:02 AM PST WEDNESDAY...MODERATE NORTHERLY WINDS
WILL PERSIST OVER PORTIONS OF THE COASTAL WATERS THIS
MORNING...BUT ARE EXPECTED TO DIMINISH THROUGH OUT THE DAY AS THE
PARENT STORM SYSTEM MOVES FURTHER INLAND. EXPECT FRESH SWELL WITH
CHAOTIC SEAS ALONG THE COAST THIS MORNING. SEAS WILL IMPROVE THIS
EVENING AS THE WINDS DIMINISH. GENTLE SEAS AND LIGHT WINDS ARE
THEN EXPECTED THROUGH THE WEEKEND.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...WIND ADVISORY...ENTIRE SF BAY AREA AND SANTA CRUZ COUNTY
SCA...MONTEREY BAY UNTIL 9 AM
SCA...PT REYES TO PIGEON PT 0-10 NM UNTIL 9 AM
SCA...PIGEON PT TO PT PINOS 0-10 NM UNTIL 9 AM
SCA...SF BAY NORTH OF THE BAY BRIDGE UNTIL 1 PM
SCA...SF BAY SOUTH OF THE BAY BRIDGE UNTIL 1 PM
SCA...PT REYES TO PIGEON PT 10-60 NM UNTIL 1 PM
SCA...PIGEON PT TO PT PINOS 10-60 NM UNTIL 1 PM
SCA...PT PINOS TO PT PIEDRAS BLANCAS 10-60 NM UNTIL 1 PM
&&
$$
PUBLIC FORECAST: AC
AVIATION: DRP
MARINE: LARRY
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AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
953 PM PST TUE DEC 30 2014
...A COLD AND WINDY END TO 2014...
.SYNOPSIS...STRONG AND GUSTY NORTH TO NORTHEAST WINDS WILL
CONTINUE ACROSS THE SAN FRANCISCO BAY AREA THROUGH WEDNESDAY
MORNING BUT NOT AS STRONG AS TUESDAY AFTERNOON. A COLD AIRMASS
IN PLACE WILL RESULT IN LOW WIND CHILLS TONIGHT AND THEN THE
COLDEST TEMPERATURES OF THE SEASON WEDNESDAY NIGHT AS WINDS SUBSIDE.
TEMPERATURES WARM LATE IN THE WEEK INTO THE WEEKEND.
&&
.DISCUSSION...AS OF 9:00 PM PST TUESDAY...DEEP UPPER LEVEL LOW
OVER SOUTHERN CALIFORNIA IS BRINGING A COLD AIRMASS WITH STRONG
NORTH TO NORTHEAST FLOW OVER THE AREA. WINDS INCREASED
DRAMATICALLY DURING THE LATE MORNING AND AFTERNOON HOURS JUST
AFTER THE TROUGH AXIS PASSED WHEN VERTICAL MIXING WAS GREATEST
ALLOWING THE STRONG WINDS ALOFT TO MIX TO THE SURFACE. PEAK WIND
GUSTS WERE IN THE 40-45 MPH RANGE AROUND THE SFO BAY AREA WHILE
PEAK WINDS OVER 60 MPH WERE REPORTED IN THE EAST BAY HILLS.
LATEST MODELS SHOW 925 MB WINDS IN THE 35-40 KT RANGE THROUGH THE
EVENING. THIS WILL KEEP STRONG WINDS GOING IN THE NORTH AND EAST
BAY HILLS AND SANTA CRUZ MOUNTAINS THROUGH WEDNESDAY MORNING. WINDS
AT THE LOWER ELEVATIONS WILL NOT BE AS STRONG AS THEY WERE THIS AFTERNOON
AS THE LOW IS MOVING SOUTHEAST AWAY FROM THE DISTRICT AND THE
VERTICAL MIXING IS WEAKER...HOWEVER WIND GUSTS IN THE 30-35 MPH
RANGE CAN STILL BE EXPECTED THROUGH THE NIGHT IN THE LOWER
ELEVATIONS OF THE SFO BAY AREA. THE WIND ADVISORY WILL BE
CONTINUED THROUGH WEDNESDAY MORNING.
WINDS WILL DECREASE WEDNESDAY AS THE LOW CONTINUES TO MOVE OFF.
THIS WILL ALLOW FOR COLDER TEMPERATURES WEDNESDAY NIGHT.
TEMPERATURES ARE EXPECTED TO DROP BELOW FREEZING IN MANY INLAND
VALLEY LOCATIONS WITH MID TO UPPER 30S AROUND THE URBAN SFO BAY
AREA AND MRY BAY AREA. A FREEZE WARNING MAY BE ISSUED FOR WEDNESDAY
NIGHT FOR THE INLAND AND MOUNTAIN AREAS. A FROST ADVISORY MAY BE
NEEDED FOR PARTS OF THE URBAN SFO BAY AREA AND THE MRY BAY AREA.
FREEZE WARNINGS AND FROST ADVISORIES MAY BE NEEDED AGAIN THURSDAY
NIGHT. THE AIRMASS ALOFT WILL BE WARMER AS 850 MB TEMPERATURES IS
FORECAST TO BE ABOUT +6C BUT THE AIR WILL BE VERY DRY ALLOWING FOR
BETTER RADIATIONAL COOLING.
TEMPERATURES WILL SLOWLY WARM THIS WEEKEND AS AN UPPER LEVEL RIDGE
MOVES OVER THE AREA FROM THE WEST. THE RIDGE WILL HOLD THROUGH
EARLY NEXT WEEK. MEDIUM RANGE MODELS ARE HINTING AT A CHANCE OF
RAIN THE MIDDLE OF NEXT WEEK. THE LATEST GFS AND ECMWF ARE
SHOWING THIS AND EVEN THE LATEST RUN OF THE CANADIAN IS ON BOARD
NOW. SO HOPES ARE RISING THAT WE MAY SEE SOME RAIN AROUND THE
MIDDLE OF NEXT WEEK BUT IT WONT BE A LOT OF RAIN.
&&
.AVIATION...AS OF 10 PM PST TUESDAY...AN ENERGETIC WINDSTORM WILL
CONTINUE TO BRING GUSTY NORTH WINDS WHILE DESCENDING INTO SOUTHERN
CALIFORNIA LATE THIS EVENING. AIRPORTS ACROSS THE REGION HAVE
REPORTED SIGNIFIANT DECLINES IN WIND SPEEDS WITH THE NOTABLE
EXCEPTION OF SFO... WHICH CONTINUES TO GUST TO AROUND 40KTS.
MODELS HAVE STRUGGLED WITH WIND SPEEDS AND TIMING SO FAR...
HOWEVER THE HRRR HAS BEEN CONSISTENT IN WEAKENING NEAR SURFACE
WINDS BY 07Z SINCE THIS AFTERNOON. WINDS AND GUSTS WILL DIMINISH
THROUGH THE NIGHT.
VICINITY OF KSFO...VFR. NORTH WINDS WILL REMAIN GUSTY THROUGH THE
NIGHT AT KSFO. STRONGEST WINDS SHOULD DIMINISH AFTER 07Z.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...VFR.
&&
.MARINE...AS OF 9 PM PST TUESDAY...STRONG NORTHEAST WINDS WILL
PERSIST THROUGH THE REMAINDER OF THE EVENING BEFORE TAPERING LATE
TONIGHT AND EARLY WEDNESDAY. EXPECT FRESH SWELL WITH CHAOTIC SEAS
AND HAZARDOUS CONDITIONS ALONG THE COAST WITH THE STRONG OFFSHORE
WINDS. DIMINISHING NW SWELL THROUGH THE FORECAST PERIOD.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...WIND ADVISORY...ENTIRE SFO BAY AREA AND SANTA CRUZ COUNTY
SCA...SF BAY SOUTH OF THE BAY BRIDGE
SCA...PT ARENA TO PT REYES 0-10 NM
SCA...PT REYES TO PIGEON PT 0-10 NM
SCA...PIGEON PT TO PT PINOS 0-10 NM
SCA...PT ARENA TO PT REYES 10-60 NM
SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM UNTIL 4 AM
SCA...PT REYES TO PIGEON PT 10-60 NM
SCA...PIGEON PT TO PT PINOS 10-60 NM
SCA...PT PINOS TO PT PIEDRAS BLANCAS 10-60 NM
SCA...MONTEREY BAY UNTIL 3 AM
GLW...SF BAY NORTH OF THE BAY BRIDGE
&&
$$
PUBLIC FORECAST: W PI
AVIATION: DRP
MARINE: MM
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AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
610 PM MST THU JAN 1 2015
.UPDATE...
ISSUED AT 609 PM MST THU JAN 1 2015
THE WINTER STORM WARNING FOR THE CORTEZ AREA WAS ALLOWED TO
EXPIRE. OCCASIONAL SNOWFALL WILL CONTINUE BUT ADDITIONAL
ACCUMULATE SHOULD BE LESS THAN 2 INCHES.
&&
.SHORT TERM...(TONIGHT THROUGH FRIDAY NIGHT)
ISSUED AT 320 PM MST THU JAN 1 2015
THE HEAVIEST SNOWFALL OCCURRED LATE LAST NIGHT AND EARLY THIS
MORNING ACROSS THE FOUR CORNERS REGION AS PREDICTED. REPORTS
INDICATED 3 TO 5 INCHES OF SNOWFALL ACROSS MUCH OF THE REGION
WITH SNOWFALL RATES NEAR 1 INCH PER HOUR IN SOME LOCATIONS. UPWARD
FORCING IMPRESSIVE DURING THIS PERIOD AHEAD OF MID-LEVEL LOW
CENTERED OVER NORTH-CENTRAL ARIZONA. AT 12Z...GOOD SURFACE
CONVERGENCE IN EVIDENCE WITH SURFACE LOW CENTERED SOUTH OF KDRO
ACCORDING TO RAP ANALYSIS. CONCURRENTLY...STRONG MID-LEVEL QG
ASCENT OVER THE AREA TOPPED BY DIVERGENCE AT HIGHER LEVELS OF THE
TROPOSPHERE WHERE LEFT EXIT REGION OF JET WAS POSITIONED.
HOWEVER...DURING THE AFTERNOON COVERAGE AND SNOWFALL RATES HAD
DECREASED SIGNIFICANTLY AS FORCING WAS DIMINISHED. SOUTHWESTWARD
FLOWING JET ON THE BACK SIDE OF THE LOW CONTINUED TO PROPAGATE TO
THE SOUTHWEST WHILE THE NORTHEASTWARD FLOWING JET ON THE LEADING
EDGE MOVED OVER THE SOUTHERN PLAINS. THE SHEARING MOMENT BETWEEN
THESE FLOWS STRETCHED THE LOW ALONG A SOUTHWEST TO NORTHEAST AXIS.
AS A RESULT...DYNAMIC FORCING SHIFTED TO THE NORTHEAST CAUSING THE
SURFACE AND 7H LOW CIRCULATIONS TO MOVE IN THAT DIRECTION. IN
ADDITION TO THE LOSS OF DYNAMIC FORCING OVER THE SOUTHERN FORECAST
AREA...OROGRAPHIC LIFT ALSO IMPACTED AS WEAK 7H LOW RECENTERED
OVER THE SAN JUANS RESULTING IN WEAK AND VARIED WINDS.
MODELS IN GOOD AGREEMENT...GENERATING VERY LITTLE QPF OVER MOST OF
THE LOWER ELEVATIONS OF SOUTHEAST UTAH AND SOUTHWEST COLORADO
DURING THE REMAINDER OF THE AFTERNOON AND THIS EVENING. THEREFORE
...WILL CANCEL WINTER STORM WARNINGS FOR THESE AREAS WITH THIS
PACKAGE. HOWEVER...RAP13 AND HRRR BOTH INDICATED MODERATE SNOWFALL
WILL CONTINUE ALONG A SOUTHWEST TO NORTHEAST ORIENTED BAND
CENTERED OVER KCEZ. CONSEQUENTLY...WILL HOLD ONTO WINTER STORM
WARNING FOR MODERATE SNOWFALL OVER THE SOUTHWEST CORNER OF THE
STATE. IN ADDITION...LIGHT TO MODERATE SNOW SHOULD CONTINUE OVER
THE SAN JUAN MOUNTAINS WHILE COVERAGE INCREASES OVER THE CENTRAL
COLORADO MOUNTAINS AS DYNAMIC FORCING BECOMES MORE FAVORABLE. ONLY
EXPECTING 2 TO 4 INCHES WITH LOCALLY HIGHER AMOUNTS IN THE CENTRAL
MOUNTAINS SO WILL NOT EXPAND WINTER WEATHER ADVISORIES...THOUGH
WILL CONTINUE HILITES ACROSS THE SAN JUANS INTO THE EVENING.
SUBSIDENCE AND DRYING SETS IN LATER TONIGHT AS THE LOW CENTER IS
DRIVEN SOUTHWARD BY THE SOUTHWESTWARD PROPAGATING JET ON THE LOW/S
REAR FLANK. AS A RESULT...SNOWFALL WILL DIMINISH TO A FEW
FLURRIES OVER THE CENTRAL MOUNTAINS AFTER MIDNIGHT. ANTICYCLONIC
FLOW TO THE NORTH WILL INHIBIT SNOWFALL FRIDAY...THOUGH CANNOT
ENTIRELY RULE OUT A FEW FLURRIES ALONG THE DIVIDE FRIDAY
AFTERNOON. A SHORTWAVE TROUGH DROPPING TOWARD THE REGION FROM THE
NORTHWEST WILL BE THE NEXT SNOW PRODUCER OVER THE FORECAST AREA
POSSIBLY IMPACTING THE NORTHERN COLORADO MOUNTAINS FRIDAY NIGHT.
THE AREA WILL BE UNDER WARM AIR ADVECTION WHILE FLOW REMAINS
ANTICYCLONIC SO EXPECT SNOW WILL BE SCATTERED AND LIGHT...LIKELY
HOLDING OFF UNTIL AFTER MIDNIGHT AS INDICATED BY FAVORED GFS AND
ECMWF SOLUTIONS.
WAA WILL ALLOW AIRMASS TO MODERATE A BIT...BUT TEMPERATURES WILL
REMAIN COLDER THAN NORMAL FOR THE LATTER PART OF THE WEEK.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 320 PM MST THU JAN 1 2015
EXPECT SNOW WILL INCREASE OVER THE NORTHERN COLORADO MOUNTAINS
SATURDAY AS THE SHORTWAVE TROUGH DISCUSSED PREVIOUSLY PUSHES
ACROSS SOUTHWEST WYOMING IN THE MORNING...THEN ACROSS NORTHWEST
COLORADO DURING THE AFTERNOON. MODELS NOT GENERATING SIGNIFICANT
SNOW ACCUMULATIONS AT THIS POINT...BUT THERE REMAINS THE POTENTIAL
FOR ADVISORY LEVEL SNOW ACROSS THE PARK...GORE...ELKHEAD...AND
FLATTOP RANGES. A TIGHTENING GRADIENT ALOFT BENEATH THE NOSE OF A
SOUTHWARD FLOWING 120 KT JET WILL GENERATE STRONG AND GUSTY
NORTHWEST WINDS ACROSS THE RIDGES GENERATING AREAS OF BLOWING
SNOW.
MODELS INDICATED ANOTHER SHORTWAVE IN THE NORTHWESTERLIES WILL
BRING SIMILAR CONDITIONS SUNDAY AFTERNOON THROUGH SUNDAY NIGHT...
THOUGH IT APPEARS TO BE WEAKER THAN SATURDAY/S SYSTEM. HOWEVER...
ECMWF INDICATED THAT OROGRAPHIC SNOWFALL COULD CONTINUE WELL INTO
MONDAY SO MAY BE MORE IMPACTFUL THAN DEPICTED NOW. A RIDGE OF HIGH
PRESSURE EASES EASTWARD FROM TUESDAY TO THURSDAY BRINGING DRY AND
MILDER CONDITIONS FOR THE MIDDLE PART OF THE COMING WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 320 PM MST THU JAN 1 2015
WITH THE STORM CIRCULATION CENTER MOVING THROUGH NORTH-CENTRAL
THEN NORTHEAST NEW MEXICO TONIGHT AND THE JET RUNNING FURTHER
SOUTH AND EAST...MOST OF THE PRECIPITATION HAS SHIFTED TO THE
NORTHERN HEMISPHERE OF THE STORM. THE BEST ENHANCEMENT WILL BE
NORTH AND WEST OF A DISTURBANCE CIRCULATING OVER KCOS.
PRECIPITATION ENHANCED BY THAT DISTURBANCE WILL MOVE OVER KASE
THROUGH EARLY THIS EVENING...PROVIDING THE FURTHER DEGRADATION OF
FLIGHT CONDITIONS THERE. EXPECT MVFR CIGS AND VSBYS OVER KASE
UNTIL ABOUT 06Z AND INTERMITTENT IFR IN STRONGER SNOW SHOWERS
THROUGH ABOUT 02Z. KEGE...KRIL SHOULD SEE BRIEF MVFR CIGS AND
VSBYS THRU ABOUT 04Z AS SNOW SHOWERS ROTATE OVER THOSE LOCATIONS.
KGJT...KVEL AND ALL AIRPORTS NORTH OF I-70 SHOULD REMAIN VFR.
THE NORTHERN EDGE OF THE MAIN PRECIP BAND WILL EXTEND FROM KFNL
THEN SOUTHWEST TO KCNY. THE HEAVIEST PRECIP IN THE BAND SHOULD
EXTEND FROM KASE TO KMTJ TO ABOUT KBDG. MOUNTAINS AND HIGH PASSES
ACROSS CENTRAL CO AND SE UT WILL REMAIN OBSCURED TONIGHT AND BEGIN
OPENING UP AFTER SUNRISE. CONDITIONS WILL IMPROVE SIGNIFICANTLY
AFTER ABOUT 08Z TONIGHT.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER WEATHER ADVISORY UNTIL MIDNIGHT MST TONIGHT FOR COZ018.
WINTER STORM WARNING UNTIL MIDNIGHT MST TONIGHT FOR COZ019.
UT...WINTER STORM WARNING UNTIL MIDNIGHT MST TONIGHT FOR UTZ028.
&&
$$
UPDATE...CC
SHORT TERM...NL
LONG TERM...NL
AVIATION...CC
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
953 AM EST WED DEC 31 2014
.DISCUSSION...
...OVERCAST AND COOL MOST PLACES...
...POOR BOATING CONDITIONS TODAY...
TODAY...RADAR SHOWING A BAND OF SHOWERS OFFSHORE ST LUCIE AND MARTIN
COUNTIES WITH INDICATIONS OF WEAK LOW LEVEL SWIRL. THIS REPRESENTS
A FLORIDA FRONTAL SIGNATURE. THE BOUNDARY THEN SNAKES WEST/SOUTHWEST
ACROSS THE SOUTHERN PENINSULA. THE MAIN QUESTION REVOLVES AROUND
POPS AND WHETHER SOME OF THE DOWNPOURS OFFSHORE WILL IMPACT THE
COAST...PARTICULARLY THE TREASURE COAST.
THE GFS KEEPS THE MAIN AREA OF MODERATE PRECIP AMOUNTS OFFSHORE.
EVEN THE NAM...WHICH SHOWS THE WEAK LOW LEVEL SWIRL...DOES NOT BRING
ANY MODERATE AMOUNTS INTO THE COAST. THE HRRR AND LOCAL WRF ARE ALSO
NOT BULLISH WITH PRECIP ALONG THE SOUTH COAST.
THE REST OF THE AREA WILL HAVE EXTENSIVE LOW CLOUDINESS AS EVIDENCED
BY SATELLITE AND SOUNDINGS WHICH SHOW MOISTURE OVERRUNNING THE
SHALLOW COOL AIR. OVERALL ISENTROPIC LIFT HAS BEEN DIMINISHING SO
THE MAIN CHANCE FOR LIGHT PRECIP WILL BE ALONG THE COAST WHERE LOW
LEVEL ONSHORE FLOW IS DEVELOPING. FLOW OFF THE COOL SHELF WATERS
AND CLOUD COVER WILL KEEP MAX TEMPS DOWN ESPECIALLY IN THE NORTH.
MAY HAVE TO TWEAK READINGS DOWN A FEW DEGREES EVERYWHERE.
PRELIMINARY POP GRID UPDATE SHOWS POPS TRIMMED BACK INLAND AND NORTH
WITH LIGHT PRECIP AMOUNTS...AND HIGHEST POPS/QPF ALONG THE TREASURE
COAST.
&&
.AVIATION...PREVAILING MVFR CEILINGS WITH AREAS OF IFR ACROSS THE
NORTH TERMINALS FOR MUCH OF THE PERIOD. FEW PATCHES OF LIGHT
RAIN/MIST THERE TOO. SOME OF THE SHOWER ACTIVITY PUSHING INTO THE
COAST KMLB TO KSUA COULD ALSO RESULT IN IFR CONDITIONS. ONLY SMALL
UPDATES EXPECTED TO THE CURRENT SET OF TAFS.
&&
.MARINE...
CURRENTLY-NEW YEARS DAY...NORTH/NORTHEAST WIND SURGE WORKING
DOWN THE COAST BEHIND FRONTAL BOUNDARY WILL PRODUCE MARGINALLY
HAZARDOUS CONDITIONS FOR SMALL CRAFT FROM ABOUT CAPE CANAVERAL
NORTHWARD.
CONTINUED VEERING OF THE WINDS SHOULD CAUSE THE FRONTAL BOUNDARY TO
REMAIN QUASI STATIONARY NEAR THE SOUTHERN WATERS. THIS WILL LIKELY
RESULT IN LIGHTER AND MORE VARIABLE WINDS THERE...BUT WEATHER WILL
BE POOR DUE TO A HIGHER COVERAGE OF SHOWERS.
THE NAM INDICATES NORTHEAST/EAST WINDS REMAINING ELEVATED LONGER IN
THE NORTH WITH A WEAK LOW SPINNING UP OFF OUR COAST. WILL NOT QUITE
GO WITH THAT SOLUTION YET...BUT FAVOR THE 15-20 KNOT WINDS HOLDING
ON LONGER THAN THE GFS INDICATES.
THEREFORE WILL FORECAST SMALL CRAFT EXERCISE CAUTION IN THE
NORTHERN WATERS INTO TONIGHT. EARLY NEW YEARS DAY BOATING
CONDITIONS MAY ALSO BE POOR IN THE NORTH...SO SMALL CRAFT OPERATORS
WILL WANT TO KEEP THAT IN MIND WHEN PLANNING THEIR ACTIVITIES.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
FORECASTS...LASCODY
IMPACT WX...WIMMER
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
731 PM EST THU JAN 1 2015
.UPDATE...
ISSUED AT 731 PM EST THU JAN 1 2015
MOISTURE IS ON ITS WAY IN AS EVIDENT BY THE LIGHT RADAR RETURNS
CURRENTLY SHOWING UP ACROSS WESTERN TN/KY. TEMPERATURES ACROSS THE
SOUTHERN PORTION ARE RANGING FROM 36 TO 41 DEGREES...WITH DEW POINTS
RUNNING FROM THE MID TEENS TO THE MID 20S. THE CURRENT SHORT RANGE
MODELS CONTINUE TO SUPPORT SOME LIGHT PRECIP SKIMMING THE KY/TN
BORDER THROUGH THE OVERNIGHT...FALLING AS LIGHT RAIN/SLEET/FREEZING
RAIN DEPENDING ON HOW QUICKLY THE COLUMN SATURATES. INITIALLY...THE
DEW POINTS WILL MOST LIKELY COME UP FASTER THAN THE TEMPERATURE DROPS
OFF. THIS MAY KEEP THE FREEZING RAIN POTENTIAL LOWER SINCE GROUND
TEMPERATURES ARE GENERALLY IN THE UPPER 30S. FURTHER NORTH...SKIES
HAVE PARTIALLY CLEARED THROUGH EARLY THIS EVENING...WITH A FEW
VALLEYS ALREADY CLOSE IF NOT DROPPING BELOW FORECAST LOWS. WILL ALLOW
FROM SOME MID 20S IN THE SHELTERED VALLEYS IN THE NORTHEAST...WHERE
THICKER CLOUDS WILL LIKELY HOLD OFF FOR ANOTHER FEW HOURS. THE MODELS
CONTINUE TO SHOW A LITTLE SURGE OF PRECIP COMING IN FROM NORTH
CENTRAL KENTUCKY TOWARDS DAWN. THIS APPEARS TO BE ASSOCIATED WITH A
SMALL POCKET OF UPPER LEVEL DIVERGENCE. THE HRRR SHOWS ONLY WEAK
RETURNS MAKING IT IN TO OUR NORTH TOWARDS DAWN...AND ANYTHING THAT
DOES MAKE IT TO THE GROUND WOULD LIKELY BE IN THE FORM OF SLEET BASED
ON THE FORECAST SOUNDINGS. WILL MAINTAIN THE DRY FORECAST FOR THE
NORTH FOR NOW AND REASSESS ONCE THE 00Z DATA COMES IN. UPDATES WILL
BE FORTHCOMING.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 348 PM EST THU JAN 1 2015
HIGH PRESSURE WILL GIVE WAY TO AN ADVANCING STORM SYSTEM OVER THE
NEXT 36 HOURS. A WARM FRONT WILL PASS THROUGH OUR REGION FRIDAY
NIGHT BRINGING STRONG RAIN CHANCES. BEFORE THAT HAPPENS...WEAK
OVERRUNNING WILL CAUSE CLOUDS TO ADVANCE BACK TO THE NORTH TONIGHT
AND THEN LOWER DURING THE DAY FRIDAY AS THE AIRMASS MOISTENS FROM
THE TOP DOWN. FORECAST MODELS CONTINUE TO INDICATE THE POSSIBILITY
OF SOME LIGHT PRECIP BREAKING OUT LATE TONIGHT INTO EARLY FRIDAY
MORNING. BEST CHANCES FOR THAT HAPPENING ARE ALONG THE TENNESSEE
BORDER...BUT SOME SPOTTY PRECIP MAY SNEAK NORTHWARD EARLY SATURDAY
MORNING. WILL ADVERTISE A MIX OF LIGHT RAIN AND SLEET WITH SOME
SPOTTY FREEZING RAIN WHERE FORECAST TEMPS FLIRT WITH FREEZING...
ALTHOUGH PROBABILITY OF OCCURRENCE OF ANY PRECIP IS LOW (GENERALLY
ONLY 20 TO 30 PERCENT). RAIN CHANCES RAMP UP FRIDAY AFTERNOON AND
FRIDAY NIGHT AFTER SURFACE TEMPS WARM WELL ABOVE FREEZING ENDING ANY
THREAT FOR WINTRY PRECIP. DECIDED TO REMOVE ANY MENTION OF FREEZING
RAIN FROM THE FORECAST NORTH OF I-64 LATE FRIDAY NIGHT FIGURING
SURFACE TEMPS WILL HAVE A HARD TIME FALLING BACK TOWARD FREEZING
WITH SOUTHERLY FLOW/WARM ADVECTION IN PLACE.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 348 PM EST THU JAN 1 2015
MODELS ARE STILL IN DECENT AGREEMENT STARTING OUT THE EXTENDED
PORTION OF THE FORECAST. BY SATURDAY MORNING...MODELS ARE CONTINUING
TO DEPICT PARTIAL PHASING OF THE NORTHERN AND SOUTHERN STREAMS OVER
NORTH AMERICA. A CLOSED LOW WHICH IS EXPECTED TO BE IN NEW MEXICO
AND NORTHERN TX WILL BE THE MAIN FOCUS OF CONCERN AS WE START OUT
THE FORECAST. THIS LOW WILL SHIFT NEWARD AND LOSE CONSIDERABLE
STRENGTH AS IT MOVES JUST N OF THE OHIO RIVER VALLEY THROUGH SUNDAY
MORNING. AFTER IT PASSES...MUCH OF THE CENTRAL CONUS WILL BE LEFT IN
A GENERAL TROUGHING PATTERN...WITH MUCH OF KY IN A STRONG PRESSURE
GRADIENT ON THE LEEWARD SIDE OF THE TROUGH AT 12Z SUNDAY WITH SW
FLOW. AS THE THROUGH SHIFTS EASTWARD...HEIGHTS WILL RAPIDLY DECREASE
ACROSS KY THROUGH SUNDAY EVENING...THOUGH THE TROUGH ITSELF DOES
SHOW SIGNS OF BROADENING OUT. MODELS ARE SURPRISINGLY STILL IN GOOD
AGREEMENT AS THE AXIS OF THIS TROUGH PASSES OVER KY SUNDAY NIGHT AND
MONDAY...BEFORE HEIGHTS FINALLY START RISING AGAIN ON THE BACK END
MONDAY NIGHT AND ON. IT APPEARS AS THOUGH THE LOW RESPONSIBLE FOR
THIS TROUGH /OVER NE CANADA/ WILL SLOW ITS PROPAGATION...SO THE RISE
IN HEIGHTS WILL BE MUCH SLOWER AND CONTINUE THROUGH THE REMAINDER OF
THE EXTENDED...COMPARED TO HOW QUICKLY THEY DECREASED AS THE TROUGH
NEARED KY.
A SURFACE LOW WILL PROCEED THE CLOSED LOW THAT IS EXPECTED TO MOVE
JUST NORTH OF KY. MODELS CONTINUE TO DEPICT DECENT OVERRUNNING AS
THE SURFACE LOW GRAZES THE WESTERN PORTION OF KY ON ITS TRACK NEWARD
DURING THE DAY SATURDAY. THIS OVERRUNNING...IN ADDITION TO A GOOD
SOUTHERLY FLOW OF MOISTURE FROM THE GULF OF MEXICO...WILL LEAD TO
WIDESPREAD MODERATE PRECIP ACROSS THE REGION. KY WILL ORIGINALLY
FIND ITSELF IN THE WARM SECTOR OF THIS SYSTEM AT 12Z SATURDAY...WITH
SW FLOW BRINGING IN WARMER TEMPS IN THE LOW...MID AND UPPER LEVELS.
THIS STILL SUPPORTS AN IMPRESSIVE WARM NOSE DEVELOPING...SUGGESTING
THAT MOST OF THE PRECIP WILL FALL AS RAIN. TEMPERATURES WERE RAISED
A DEGREE OR TWO IN THE NORTH...SO REMOVED ANY MENTION OF FREEZING
RAIN OR SNOW FOR 12Z SATURDAY. GIVEN HOW FAST THE SYSTEM IS TRACKING
ACROSS KY...AND THE RAPID DECREASE IN HEIGHTS ALOFT...IN ADDITION TO
WARMER TEMPS AND STRONG SW FLOW...WILL CONTINUE WITH MENTION OF
POSSIBLE THUNDERSTORMS SATURDAY AFTERNOON AND NIGHT...MAINLY DURING
THE HEAVIEST RAIN. BY SUNDAY MORNING...THE SURFACE SYSTEM WILL HAVE
PASSED EAST OF THE REGION...WHILE LOSING CONSIDERABLE STRENGTH
ALOFT. THE TROUGHING PATTERN OVER THE CONUS...HOWEVER...WILL LEAVE
SW FLOW IN PLACE...SO WILL KEEP WITH CHANCES OF RAIN SATURDAY NIGHT
AND DURING THE DAY SUNDAY.
WINDS AT THIS POINT WILL THEN SWITCH TO A MORE WRLY DIRECTION IN THE
MID AND UPPER LEVELS...WITH MUCH DRIER AIR USHERING IN. CONTINUED
LOW LEVEL WRAP AROUND MOISTURE IS STILL POSSIBLE THROUGH SUNDAY
EVENING...BUT WILL QUICKLY TAPER OFF. UPSLOPE FLOW WILL KEEP POPS IN
SLIGHTLY LONGER ACROSS THE HIGHER TERRAIN IN THE SE. THIS WILL BE
THE POINT WHEN THE UPPER LEVEL TROUGH AXIS IS MOVING ACROSS AND JUST
EAST OF THE REGION...WITH MUCH COLDER AIR USHERING INTO THE REGION.
AS A RESULT...PREVIOUS FORECAST HAD LINGERING RAIN CHANGING OVER TO
SNOW SUNDAY EVENING. HOWEVER...IT SEEMS AS THOUGH MODELS ARE
TRENDING THE POPS OUT SLIGHTLY FASTER NOW...SO EXPECT THAT BELOW
FREEZING TEMPS WON/T PLAY MUCH OF A CONCERN SINCE PRECIP WILL BE OUT
OF THE AREA BEFORE IT TAKES AFFECT. KEPT ANY PRECIP SUNDAY EVENING
AS RAIN BEFORE TAPERING OFF.
RISING HEIGHTS AND SURFACE HIGH PRESSURE SHOULD KEEP MOST OF THE
CONCERN FOR FURTHER PRECIP OUT OF THE REGION THROUGH MIDWEEK WHILE
TEMPERATURES STAY WELL BELOW NORMAL. SEVERAL SHORTWAVES WILL LIKELY
QUICKLY PASS ALONG THE LONGWAVE TROUGH AXIS...BRINGING THE THREAT OF
SHORT LIVED SHOTS OF PRECIP THROUGH THE LAST PART OF THE FORECAST.
THE FIRST OF THESE WILL BE TUESDAY NIGHT...WITH SOME POSSIBILITY
THAT THE PRECIP COULD GRAZE OUR FAR NORTHERN COUNTIES IN THE FORM OF
A QUICK LIGHT SNOW. ANOTHER ONE MAY IMPACT THE REGION WEDNESDAY
NIGHT INTO THURSDAY AS WELL.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 731 PM EST THU JAN 1 2015
CLOUDS WILL GRADUALLY LOWER AND ADVANCE NORTHWARD THROUGH THE
NIGHT...WITH LIGHT PRECIPITATION THREATENING MAINLY ALONG AND SOUTH
OF THE HAL ROGERS PARKWAY. THIS WILL FALL AS MAINLY LIGHT
RAIN...HOWEVER SOME SLEET IS ALSO POSSIBLE AT ONSET. EXPECT MVFR
CLOUDS TO MOVE IN THE SOUTH BETWEEN 06 AND 09Z...AND THEN GRADUALLY
BUILD NORTHWARD THROUGH THE DAY ON FRIDAY...WITH LOCATIONS ALONG AND
NORTH OF THE I-64 CORRIDOR LIKELY STAYING VFR UNTIL LATER FRIDAY
EVENING WHEN A WARM FRONT ADVANCES ACROSS THE AREA FROM THE SOUTH.
SOUTHWEST WINDS OF 5 TO 10 KTS...WITH LOCATIONS ALONG THE I-64
CORRIDOR MAINTAINING AROUND 10 KTS...WILL CONTINUE THROUGH THE
NIGHT BEFORE DIMINISHING TOWARDS DAWN.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEOGERIAN
SHORT TERM...ABE
LONG TERM...JMW
AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
840 PM CST THU JAN 1 2015
.DISCUSSION...
WIDESPREAD RAIN CONTINUES ACROSS THE EASTERN TWO THIRDS OF THE
REGION THIS EVENING. HAVE EVEN SEEN SOME ELEVATED THUNDERSTORMS
ACROSS OUR SOUTHERN ZONES ALONG AN ELEVATED INSTABILITY AXIS WHICH
IS SLOWLY TRYING TO ADVANCE NORTHWARD. REGIONAL RADAR MOSAICS
SHOWING SOME BREAKS IN THE COVERAGE ACROSS PORTIONS OF CENTRAL AND
NORTHEAST TEXAS. HOWEVER...OBSERVATIONS STILL SHOWING LIGHT RAIN
WITH MEASURABLE DRIZZLE ONGOING ACROSS THESE OBSERVATIONS SITES.
FOR THE UPDATE...THOUGHT ABOUT LOWERING CATEGORICAL POPS ACROSS
THE WEST OVERNIGHT WHERE THE BREAK IN THE OBSERVABLE COVERAGE
EXISTS BUT THE LATEST HRRR SUGGESTS THAT MORE DEVELOPMENT IS
POSSIBLE ACROSS CENTRAL TX AFTER MIDNIGHT...MOVING INTO OUR NE TX
ZONES. LATEST 00Z NAM OUTPUT SUPPORTS THIS REASONING AS WELL SO
TRIMMED QPF AMOUNTS BACK SOMEWHAT IN THE WEST BUT KEPT THE
CATEGORICAL WORDING. ALSO ADDED THUNDERSTORM MENTION ALONG AND
SOUTH OF A LFK/SHV/MLU LINE THROUGH THE NIGHT AS WELL.
CONCERNING OVERNIGHT TEMPS...EXPECTING VERY LITTLE CHANGE IN
TEMPERATURES THROUGH THE NIGHT. IN FACT...SINCE 4 PM...AMBIENT
TEMPS HAVE EITHER STAYED PUT OR RISEN A DEGREE OR TWO THROUGH THE
EVENING AND WOULD NOT BE SURPRISED TO SEE AN ADDITIONAL DEGREE OR
TWO CLIMB AS THE LOW LEVELS CONTINUE TO WARM. MADE THIS CHANGE TO
THE OVERNIGHT FCST ALONG WITH DEWPOINT AND RH GRIDS.
OTHERWISE...FCST IS IN PRETTY GOOD SHAPE WITH NO OTHER ADDITIONAL
CHANGES NECESSARY...13.
&&
.PREV DISCUSSION... /ISSUED 634 PM CST THU JAN 1 2015/
AVIATION...
TAF SITES WILL REMAIN UNDER MVFR/IFR CONDITIONS THROUGHOUT THE
PD...AS WIDESPREAD RAINFALL WITH LOW CIGS CONTINUES. SOME BRIEF
IMPROVEMENTS MAY BE SEEN...BUT THEY WILL BE SHORT-LIVED. WINDS
WILL REMAIN OUT OF THE NE AT 5-10 KTS.
/12/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 39 44 43 55 37 / 100 90 90 90 10
MLU 39 47 45 60 40 / 100 80 90 90 20
DEQ 37 41 39 48 33 / 90 90 90 60 10
TXK 36 41 40 51 35 / 100 90 90 70 10
ELD 37 42 41 53 37 / 100 90 90 90 10
TYR 38 42 40 54 35 / 100 90 90 70 10
GGG 39 43 42 54 36 / 100 90 90 70 10
LFK 43 48 45 56 38 / 100 70 90 90 10
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
12/13
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
703 PM EST THU JAN 1 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 351 PM EST THU JAN 1 2015
DEEP TROUGH ALOFT CENTERED OVER HUDSON BAY. MULTIPLE SHORTWAVES
MOVING THROUGH THE BASE OF THE TROUGH...BUT AFTER THE SHORTWAVE
MOVED THROUGH THIS MORNING...THERE IS NO LARGER SCALE SUPPORT OVER
THE AREA OR UPSTREAM. PRIMARY COLD FRONT TIED TO THE LAST SHORTWAVE
IS CURRENTLY SINKING SOUTHWARD OVER UPR MICHIGAN. BAND OF HEAVY SNOW
ALONG THE FRONT HAS WORKED THROUGH MARQUETTE AND MUNISING AND IS NOW
ALLIGNED FM SAWYER TO CHATHAM TO SHINGLETON AND TO NEWBERRY AS OF 20Z.
VSBY DOWN TO 1/4SM IN THIS SNOW BAND...BUT IT IS NOT LASTING TOO LONG.
LES OVER THE WESTERN CWA IS SCUFFLING ALONG. IN FACT AFTER THE FRONT
MOVED THROUGH THE KEWEENAW...SPOTS HAVE CLEARED OUT BRIEFLY. HINTS OF
WIND PARALLEL BANDS OVER WESTERN LK SUPERIOR...BUT DRY AIR AND
INVERSIONS BLO 5KFT IS LIMITING THIS DEVELOPMENT. BETTER LES
DEVELOPMENT OVER EASTERN LK SUPERIOR WITH CLOUD STREETS EXTENDING
BACK TO NCNTRL LK SUPERIOR. WILL TAKE A FEW HOURS...BUT DO EXPECT AT
LEAST MODERATE LES TO DEVELOP IN THE NW LOW-LEVEL WINDS INTO EASTERN
CWA. BLYR WINDS OVER 30 KTS INTO THE EVENING WILL RESULT IN BLSN/POOR
VSBY IN THE HEAVIER SNOW BANDS. INVERSIONS 5-8 KFT AND TEMPS AT
INVERSION TOP OF -20C SHOULD AT LEAST RESULT IN SCT HEAVIER SNOW
SHOWERS. 17Z HRRR DOING NICE JOB WITH EXPECTED EVOLUTION THROUGH THE
EVENING...THOUGH IT SEEMS A BIT SLOW WITH TIMING OF HEAVIER SNOW BAND
TIED TO THE FRONT.
ADDITIONAL SNOW AMOUNTS SHOULD STAY IN CHECK GIVEN LACK OF ENHANCED
MOISTURE AND LIFT SINCE WE ARE WITHIN A PURE LES REGIME. SUPPOSE IF
SNOW BANDS CAN STAY ANCHORED IN ONE PLACE THROUGH THE NIGHT...MAY SEE
SEVERAL INCHES OF FLUFFY ACCUMS AS ALL CONVECTIVE DEPTH IS WITHIN THE
DGZ. ALREADY ISSUED LES ADVISORY THROUGH MIDNIGHT FOR ALGER...NORTHERN
SCHOOLCRAFT...AND LUCE COUNTIES. AFTER MIDNIGHT SEEMS THAT DRY AIR
AND LOWER INVERSIONS THAT ARE AFFECTING WESTERN LK SUPERIOR AND CWA
WILL PUT CRIMP IN THE LES INTENSITY OVERNIGHT. WEAK LES WILL CONTINUE
INTO FRIDAY...MAINLY FOR AREAS FAVORED BY WNW-W WINDS...SO ESSENTIALLY
THE SNOW BELTS OF THE KEWEENAW AND ALSO TO THE EAST OF MUNISING.
CONDITIONS EVEN MORE UNFAVORABLE THAN LATER TONIGHT...BUT WITH DGZ
DOMINATING THE CONVECTIVE LAYER STILL COULD SQUEEZE OUT A COUPLE MORE
INCHES OF FLUFF IN PERSISTENT SNOW SHOWERS.
AWAY FM THE LES TONIGHT...LOWERED SKY COVER AND TEMPERATURES AS THE
DRIER AIR SHOULD WIN OUT AS IS OCCURRING UPSTREAM IN MINNESOTA AND
NORTHWEST ONTARIO THIS AFTN. INTERIOR TEMPS SHOULD DIP WELL BLO ZERO
ONCE THE NW WINDS BEHIND THE COLD FRONT BEGIN TO BACK OFF. SHOULD BE
SHARP GRADIENT TO MIN TEMPS AS YOU GET CLOSER TO LK SUPERIOR DUE TO
LINGERING LAKE EFFECT CLOUDS AS 925MB WINDS STAY WNW-NW THROUGH THE
NIGHT. ALSO MAY SEE TEMPS STEADY OR RISE LATE IN THE WEST WITH
ADVANCING DECK OF 6-9KFT ALTOSTRATUS CLOUDS. ANOTHER COOL DAY WITH
AFTN READINGS IN THE TEENS OVER THE CWA.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 408 PM EST THU JAN 1 2015
A PROMINENT RIDGE GRADUALLLY BUILDING TO THE EAST INTO WRN NOAM WILL
MAINTAIN A BROAD TROUGH FROM CENTRAL CANADA INTO THE GREAT LAKES.
AFTER LOW PRESSURE SYSTEM LIFTS NE FROM THE CNTRL GREAT LAKES...MUCH
COLDER AIR WILL MOVE INTO THE REGION AND REMAIN THROUGH MUCH OF NEXT
WEEK KEEPING LES GOING FOR MAINLY NW TO WNW FLOW FAVORED LOCATIONS.
FRI NIGHT AND SAT...A BROAD 850-600 MB WARM ADVECTION 280K-295
ISENTROPIC LIFT ZONE WILL DEVELOP FROM THE NRN PLAINS INTO NRN MN AND NRN
LAKE SUPERIOR IN RESPONSE TO THE DEVELOPING TROUGH OVER THE PLAINS
AND UPPER LEVEL DIV WITH THE RIGHT ENTRANCE OF A 250-300 MB JET
STREAK THROUGH NRN ONTARIO. THE MODELS KEEP MOST OF THE PCPN WITH
THIS FEATURE NORTH OF UPPER MI. WAA WILL RAISE TEMPS AT OR
SLIGHTLY ABOVE AVERAGE WITH READINGS IN THE MID TO UPPER 20S.
SAT NIGHT INTO SUN...A SHRTWV ORIGINATING FROM THE GULF OF ALASKA
DIVING INTO THE WRN CONUS TROUGH WILL HELP EJECT THE SW CLOSED LOW
NE TOWARD THE GREAT LAKES. THE 12Z GFS/ECMWF ALONG WITH ENSEMBLES
FAVOR A LOW TRACK FROM THE SRN END OF LAKE MI TO CNTRL LAKE HURON
AND THEN NE INTO QUEBEC. STRONG 700-300 MB QVECTOR CONV ASSOCIATED
WITH THE SHRTWV WILL SUPPORT A BROAD AREA OF SNOW FROM WI INTO UPPER
MI BY LATE SAT AND ESPECIALLY LATE SAT NIGHT. MDLS CONSENSUS QPF IN
THE 0.20 TO 0.35 INCH RANGE WITH SLR VALUES AROUND 14/1 WILL SUPPORT
POTENTIAL FOR 3 TO 6 INCHES BY 18Z/SUN. ADDITIONAL SUPPORT FOR
HEAVIER SNOW IS EXPECTED OVER THE NORTH CYCLONIC NRLY FLOW AND 850
MB TEMPS DROPPING FROM -10C TO -15C BY 12Z TO -14C TO -19C BY 18Z
WILL RESULT HIGHER AMOUNTS THROUGH LAKE ENHANCEMENT. BY SUN
AFTERNOON THE DEEPER MOISTURE AND SYNOPTIC SUPPORT LIFT QUICKLY WITH
A TRANSITION TO LIGHTER PURE LES.
SUN NIGHT INTO MON...VERY COLD ARCTIC AIR WILL PLUNGE INTO THE
REGION WITH 850 MB TEMPS DROPPING TO AROUND -27C BY 12Z MON. THIS
WILL LOWER THE DGZ TOWARD THE SFC AND REDUCE POTENTIAL FOR
SIGNIFICANT LES. HOWEVER...WIND CHILL WITH A MORE WRLY SFC WIND
COMPONENT RESULTING FROM LAKE INDUCED TROUGHING WILL ALLOW TEMPS TO
DROP OFF OVER MUCH OF THE CWA. WIND CHILL VALUES IN THE -20 TO -35
RANGE ARE EXPECTED.
TUE-THU...A FEW CLIPPER SHRTWVS ARE LIKELY TO MOVE THROUGH THE REGION WITH
NW-NNW MID LEVEL FLOW IN PLACE. THIS MAY BRING REINFORCING BOUTS OF
COLD AIR AND SHIFT THE POSITIONS OF THE HEAVIER LES BANDS. TEMPS MAY
MODERATE SLIGHTLY IF SFC WINDS VEER MORE TO THE NW WITH MORE MARINE
MODIFICATION. HOWEVER...WIND CHILLS MAY REMAIN NEAR ADVY THRESHOLD
DURING THE LATER NIGHT INTO MORNING HOURS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 703 PM EST THU JAN 1 2015
UNDER A COLD AIR MASS AND WNW FLOW...LAKE EFFECT SNOW SHOWERS WILL
CONTINUE TO AFFECT KCMX THRU THIS FCST PERIOD WITH MVFR CONDITIONS
LIKELY PREVAILING. EXPECT SOME PERIODS OF VFR THIS EVENING AS DRIER
AIR HAS CAUSED -SHSN TO DIMINISH. ON FRI...BACKING WINDS SHOULD
RESULT IN ENHANCED CONVERGENCE AND A BAND OF HEAVIER -SHSN LIFTING N
AND IMPACTING KCMX LATE MORNING/EARLY AFTN WITH IFR CONDITIONS
POSSIBLE. AT KIWD...DRY AIR AND WINDS HAVING JUST ENOUGH OF A
WESTERLY COMPONENT SHOULD KEEP LAKE EFFECT SNOW SHOWERS/MVFR
CONDITIONS N OF THE TERMINAL TONIGHT. SO...VFR CONDITIONS ARE
EXPECTED TO PREVAIL TONIGHT. WITH WINDS BACKING FURTHER ON FRI...
VFR CONDITIONS WILL CONTINUE AT KIWD. AT KSAW...DOWNSLOPE COMPONENT
TO THE WIND TONIGHT SHOULD KEEP CONDITIONS VFR. VFR CONDITIONS WILL
THEN CONTINUE THRU FRI.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 351 PM EST THU JAN 1 2015
NW GALES DIMINISH THIS EVENING OVER THE EAST HALF. HEAVY FREEZING
SPRAY WILL ALSO END LATE TONIGHT. WINDS SETTLE DOWN TO LESS THAN 25
KTS LATER TONIGHT THROUGH FRIDAY NIGHT AS HIGH PRESSURE MOVES
OVERHEAD. EXPECT A BRIEF PERIOD OF STRONGER SE WINDS ON SATURDAY...BUT
THE BETTER CHANCE OF STRONGER WINDS WILL BE LATE SATURDAY NIGHT INTO
SUNDAY AS NORTH TO NORTHWEST WINDS INCREASE AS A LOW PRESSURE SYSTEM
LIFTS OVER THE GREAT LAKES THEN MOVES EAST OVER QUEBEC. BEST SHOT OF
GALES WILL BE OVER THE EAST HALF OF LK SUPERIOR ON SUNDAY. NW WINDS
TO 30 KTS WILL LINGER OVER MUCH OF LK SUPERIOR INTO EARLY NEXT WEEK
BEHIND THE WEEKEND SYSTEM. MORE HEAVY FREEZING SPRAY IS EXPECTED LATE
THIS WEEKEND INTO EARLY NEXT WEEK AS ARCTIC AIR FLOWS ACROSS LK
SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR MIZ006-
007-085.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 1 AM EST FRIDAY FOR LSZ265-
267.
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST /6 AM CST/ FRIDAY
FOR LSZ241>245-263-264-266.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...JLB
AVIATION...ROLFSON
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
430 PM EST WED DEC 31 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 429 PM EST WED DEC 31 2014
WV IMAGERY AND RUC ANALYSIS INDICATED NW MID/UPPER LEVEL FLOW FROM
NW CANADA INTO THE GREAT LAKES BETWEEN A TROUGH OVER HUDSON BAY AND
A RIDGE FROM THE ERN PACIFIC INTO BC. A SHORTWAVE TROUGH WAS MOVING
THROUGH UPPER MI WITH ANOTHER WEAKER SHRTWV UPSTREAM OVER MANITOBA.
ANOTHER CLIPPER SHRTWV WAS FARTHER UPSTREAM OVER NW SASK. AT THE
SFC...STRONG WEST WINDS PREVAILED ACROSS THE REGION BETWEEN A 988 MB
LOW NEAR HUDSON BAY AND 1036 MB ARCTIC HIGH PRES INTO THE SRN
PLAINS. THE STRONGEST WINDS THIS MORNING INTO EARLY AFTERNOON ACROSS
LAKE SUPERIOR OCCURRED AS THE STRONGER PRES FALLS SLID THROUGH NRN
ONTARIO. WITH 850 MB TEMPS AROUND -19C AND CONVERGENT WRLY FLOW
DEVELOPING LES HAS INCREASED ACROSS THE KEWEENAW AS WINDS VEERED
FROM SW TO W.
TONIGHT...EXPECT THE STRONGEST LOW LEVEL CONV SUPPORTING LES TO
REMAIN OVER THE KEWEENAW. EVEN WITH A FAVORABLE POSITION OF THE DGZ
IN THE CLOUD LAYER...THE STRONGER WINDS WILL CREATE ENOUGH
COMPACTION/FRACTURING TO LIMIT SLR VALUES CLOSER TO 20/1. SO OVERALL
ACCUMULATIONS TONIGHT IN THE 2 TO 5 INCH RANGE ARE EXPECTED. WINDS
GUSTING INTO THE 30 TO 40 MPH RANGE WILL ALSO CONTINUE TO PRODUCE
CONSIDERABLE BLOWING AND DRIFTING SNOW IN OPEN AREAS WHERE OCNL
WHITEOUT CONDITIONS ARE POSSIBLE. WINDS ARE EXPECTED TO DIMINISH
OVERNIGHT REDUCING THE BLSN HAZARDS.
THU...THE NRN SASK SHRTWV TROUGH WILL BRUSH THE AREA WITH ENOUGH
700-500 MB QVECTOR CONV AND 800-600 MB FGEN TO SUPPORT AN AREA OF
LIGHT SNOW FROM NRN MN INTO NRN WI AND UPPER MI. WITH THE LACK OF
SIGNFICANT MOISTURE INFLOW/AVAILABILITY...SNOW AMOUNTS OF A HALF
INCH OR LESS ARE EXPECTED. HOWEVER...THE DEEPER MOISTURE WITH
INCREASING INVERSION HEIGHTS INTO THE AREA WILL SUPPORT GREATER LES
INTENSITY FOR THE W TO WNW FLOW LES SNOW BELTS. SINCE THE STRONGER
LOW LEVEL CONV IS EXPECTED TO SHIFT SOUTHWARD OVERALL SNOW AMOUNTS
SHOULD REMAIN IN THE 1 TO 3 INCH RANGE.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 316 PM EST WED DEC 31 2014
AN UPPER TROUGH OVER EASTERN CANADA LEAD TO COLD AIR AND LAKE
EFFECT SNOW OVER THE NORTHWEST WIND SNOW BELTS TO START THE PERIOD.
THIS LIGHT TO OCCASIONALLY MODERATE LAKE EFFECT SNOW WILL CONTINUE
IN THOSE NORTHWEST WIND BELTS ON THURSDAY NIGHT...BUT AS THE LOW
LEVEL WINDS BACK LATE THURSDAY NIGHT INTO FRIDAY MORNING...WILL
FOCUS THE POPS/SNOW TO THE WEST-NORTHWEST AREAS ON FRIDAY (AND
WESTERLY AREAS LATE FRIDAY AFTERNOON). WHILE LAKE INDUCED
EQUILIBRIUM LEVELS WILL BE AROUND 8KFT...THERE ARE SOME CONCERNS IN
THE AMOUNT OF MOISTURE AVAILABLE AS SUBSIDENCE AND DRIER AIR ARRIVE
THURSDAY NIGHT FROM A HIGH MOVING SOUTHEAST INTO MINNESOTA.
THUS...WILL STICK WITH A DUSTING TO 3-4IN EVERY 12HRS THROUGH
FRIDAY...WITH THE HIGHEST AMOUNTS OVER THE EAST WITH THE LONGER
FETCH AND SOME INDICATIONS OF A LINGERING TROUGH AIDING
CONVERGENCE TOWARDS WHITEFISH POINT. THE HIGH WILL SHIFT SOUTHEAST
OF THE AREA ON FRIDAY EVENING...BACKING WINDS TO THE SOUTHWEST AND
ONLY LEAVING LAKE EFFECT SNOW OVER THE KEWEENAW FOR FRIDAY NIGHT.
THE FOCUS THEN TURNS TO THE INTERACTION AND PHASING OF THE SPLIT
FLOW FOR THE START OF THE WEEKEND. MODELS SEEM TO COMING INTO
BETTER AGREEMENT ON THE OVERALL IDEA FOR THE WEEKEND...ALTHOUGH
THERE ARE STILL SMALLER DIFFERENCES THAT COULD HAVE AN IMPACT ON
THE AMOUNT OF SNOW SEEN OVER PARTS OF THE U.P. THERE ARE TWO
FEATURES AT PLAY FOR THIS WEEKEND...THE FIRST IS THE REMNANTS OF
THE UPPER LOW PRODUCING SNOW OVER THE SOUTHWEST CONUS TODAY AND THE
SECOND FEATURE IS A SHORTWAVE CURRENTLY OVER THE ALEUTIANS ISLANDS
AND DROPPING SOUTHEAST INTO THE NORTHERN ROCKIES ON FRIDAY NIGHT.
THIS WILL LEAD TO A LOW DEVELOPING IN THE LEE OF THE NORTHERN
ROCKIES AND THEN MOVING EAST INTO THE DAKOTAS AND WESTERN MINNESOTA
BY SATURDAY MORNING. EXPECT SNOW TO SPREAD EAST AHEAD OF THIS LOW
AND INTO THE NORTHWEST HALF OF THE CWA...ASSOCIATED WITH STRONG MID
LEVEL WARM AIR ADVECTION. WHILE THE HEAVIEST SNOW APPEARS TO OCCUR
OVER LAKE SUPERIOR...WILL SHOW SOME LIKELY POPS OVER AND AROUND THE
KEWEENAW PENINSULA FOR SATURDAY. AS THAT IS OCCURRING...THE
NORTHERN SHORTWAVE WILL CONTINUE TO DIVE SOUTHEAST AND PHASE WITH
THE SOUTHERN UPPER LOW AND LEAD TO BOTH EJECTING NORTHEAST THROUGH
THE LOWER GREAT LAKES REGION SATURDAY NIGHT INTO SUNDAY. AS
EXPECTED IN THESE PHASING EVENTS...EACH MODEL RUN GIVES A SLIGHTLY
DIFFERENT IDEA ON THE EVOLUTION OF THE PHASED FEATURES AND IN TURN
THE SURFACE FEATURES. OVERALL...THE GENERAL IDEA IS FOR A
STRENGTHENING LOW TO LIFT NORTHEAST THROUGH SOUTHEAST LOWER
MICHIGAN ON SATURDAY NIGHT AND THEN INTO QUEBEC ON SUNDAY. WITH
THAT TRACK...WOULD EXPECT MUCH OF THE SYNOPTIC
FORCING/PRECIPITATION ASSOCIATED WITH THOSE FEATURES TO MISS THE
U.P....BUT WOULD STILL EXPECT AT LEAST SOME LAKE ENHANCEMENT AS THE
WINDS TURN TO THE NORTHWEST BEHIND THE ELONGATED SURFACE TROUGH
STRETCHING NORTH OVER EASTERN LAKE SUPERIOR LATE SATURDAY NIGHT.
INITIALLY...WOULDN/T EXPECT THE LAKE ENHANCEMENT TO AMOUNT TO TOO
HIGH OF SNOWFALL AMOUNTS ON SATURDAY NIGHT...BUT AS MUCH COLDER AIR
MOVES INTO THE AREA (850MB TEMPS FALLING TO -25C BY 00Z MONDAY) AND
THE DEEPER MOISTURE IS STILL PRESENT FROM THE DEPARTING
SYSTEM...WOULD EXPECT THE LAKE ENHANCEMENT/EFFECT SNOW TO TAKE OFF
ON SUNDAY IN THE NORTHWEST WIND SNOW BELTS. WILL TREND POPS UP TO
DEFINITE VALUES DURING THIS PERIOD AND CONTINUE TO MENTION
MODERATE/HEAVY SNOW WORDING IN THE HWO.
BEHIND THE LOW...EXPECT THE FIRST PART OF THE WORK WEEK TO BE VERY
COLD WITH CONTINUED LAKE EFFECT SNOW. THE CANADIAN UPPER TROUGH
WILL SAG SOUTH INTO THE GREAT LAKES REGION AND KEEP THE COLD AIR IN
PLACE (850MB TEMPS IN THE LOW 20C BELOW ZERO)...WITH ANOTHER
SHORTWAVE MOVING THROUGH ON MONDAY NIGHT POTENTIALLY PULLING 850MB
TEMPERATURES CLOSE TO -30C FOR TUESDAY. THAT WILL LEAD TO VERY COLD
HIGH TEMPERATURES FOR MONDAY/TUESDAY...WITH SOME LOCATIONS OVER THE
INTERIOR WEST EVEN STRUGGLING TO RISE ABOVE 0. IN FACT...LOOKING AT
THE 00Z ECMWF ENSEMBLE MEMBERS AT KSAW AND OTHER SITES IN THE
WESTERN/CENTRAL U.P....THERE MAY END UP BEING A 24-36 HOUR PERIOD OF
SUB ZERO TEMPERATURES LATE SUNDAY NIGHT THROUGH AT LEAST TUESDAY
MORNING. THE COMBINATION OF THE COLD TEMPERATURES AT NIGHT (SINGLE
DIGITS AND TEENS BELOW ZERO) AND WINDS IN THE 5-10MPH RANGE WILL
LEAD TO LOW WIND CHILL VALUES MONDAY/TUESDAY MORNINGS AND
POTENTIALLY EVENING WEDNESDAY MORNING. AS LONG AS THE WIND SPEEDS
STAY UP...WOULD EXPECT THE NEED FOR WIND CHILL ADVISORIES AT A
MINIMUM AND WILL CONTINUE TO ADDRESS IN THE HWO.
AS FOR LAKE EFFECT DURING THE FIRST PART OF NEXT WEEK...EXPECT WINDS
TO BACK TO THE WEST ON MONDAY AND WILL FOCUS THE LAKE EFFECT POPS
IN THOSE AREAS. WITH THE AMOUNT OF COLD AIR IN PLACE...VERY LITTLE
OF THE CLOUD LAYER WILL BE IN THE DGZ AND MOST WILL BE ABOVE
IT...WHICH LEADS TO MORE COLUMN/PLATE SNOWFLAKES AND WOULD EXPECT
ACCUMULATIONS TO BE LIMITED. WINDS WILL SHIFT MORE TO THE NORTHWEST
ON TUESDAY BEHIND THAT NEXT SHORTWAVE AND WILL TREND POPS TO THAT
FAVORED WIND DIRECTION. WITH THE AMOUNT OF COLD AIR...THERE
SHOULDN/T BE MUCH OF AN ISSUE FOR AT LEAST SOME LAKE EFFECT...SO
DID TREND POPS UP TO LIKELY-DEFINITE VALUES EVEN THOUGH AMOUNTS
SHOULD BE LIMITED. AS THE UPPER TROUGH SHIFTS EAST ON WEDNESDAY AND
THROUGH THE END OF THE WORK WEEK...THE UPPER GREAT LAKES REGION
SHOULD SEE A MODERATION IN THEIR TEMPERATURES TOWARDS MORE NORMAL
VALUES TOWARDS THE END OF NEXT WEEK. LOOKING AT THE 00Z ECMWF
ENSEMBLE MEAN FOR DAYS 9-15...IT SHOWS MORE OF A ZONAL FLOW ACROSS
THE CONUS...WHICH WOULD TRANSLATE TO MORE NORMAL OR EVEN SLIGHTLY
ABOVE NORMAL TEMPERATURES HEADING INTO THE MIDDLE OF JANUARY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1243 PM EST WED DEC 31 2014
GUSTY WEST WINDS OVER 30 KNOTS WITH BLSN AND LES ACROSS THE KEWEENAW
DROP VSBY INTO THE LIFR/VLIFR RANGE THIS AFTERNOON INTO TONIGHT.
THERE MAY BE SOME IMPROVEMENT BY LATE TONIGHT OR EARLY THURSDAY AS
WINDS DIMINISH AND VEER MORE TO THE NW. OTHERWISE...MAINLY VFR
CONDITIONS AT IWD MAY GIVE WAY TO SOME MVFR CIGS LATE TONIGHT AS LOW
LEVEL WINDS ACROSS THE LAKE VEER MORE TO THE NW. THE SW TO W FLOW AT
SAW LATE TONIGHT WILL FAVOR CONTINUATION OF VFR CONDITIONS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 429 PM EST WED DEC 31 2014
LAKE SUPERIOR WILL BE STUCK BETWEEN VERY STRONG HIGH PRESSURE ACROSS
THE S PLAINS AND A DEEP HUDSON BAY LOW TODAY. GALES OF 35-45KTS WILL
CONTINUE BEFORE SLOWLY DIMINISHING TO 35KTS LATE TONIGHT INTO
THURSDAY MORNING OUT OF THE W-NW. GIVEN PLENTY OF COLD AIR...AND
STRONG WINDS...HEAVY FREEZING SPRAY WILL ALSO BE A CONCERN INTO
THURSDAY.
LOOK FOR THE TROUGH OVER LAKE SUPERIOR TO DEEPEN TONIGHT THROUGH
THURSDAY. THE HUDSON BAY LOW WILL SHIFT AND WEAKEN ACROSS N QUEBEC
THURSDAY NIGHT...ALLOWING THE TROUGH ACROSS LAKE SUPERIOR TO WEAKEN
AS WELL. HIGH PRESSURE SINKING ACROSS MANITOBA AND MINNESOTA
THURSDAY NIGHT WILL BUILD RIDGE ACROSS LAKE SUPERIOR ON FRIDAY AS IT
PROGRESSES ACROSS THE REMAINDER OF THE GREAT LAKES. A WEAK TROUGH
WILL LIKELY LINGER ACROSS MAINLY E LAKE SUPERIOR DURING THIS TIME.
EXPECT A LOW NEAR MONTANA ON FRIDAY TO TRACK ACROSS THE N AND
CENTRAL PLAINS SATURDAY MORNING...AND THE MID MISSISSIPPI VALLEY
SATURDAY AFTERNOON...BEFORE DEEPENING NORTHEASTWARD ACROSS THE LOWER
GREAT LAKES AND QUEBEC LATE SATURDAY NIGHT INTO SUNDAY. THIS WILL
BRING A TROUGH THROUGH THE AREA SATURDAY NIGHT INTO SUNDAY...ALONG
WITH THE POTENTIAL FOR N-NW GALES. HEAVY FREEZING SPRAY WILL
ALSO MAKE A RETURN ACROSS MUCH OF LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST THURSDAY FOR MIZ001-003.
LAKESHORE FLOOD ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR MIZ001-
003.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 4 AM EST /3 AM CST/ THURSDAY
FOR LSZ162-240>245-248>251-263>267.
GALE WARNING UNTIL 10 AM EST THURSDAY FOR LSZ266-267.
GALE WARNING UNTIL 7 AM EST /6 AM CST/ THURSDAY FOR LSZ162-
241>248-263>265.
HEAVY FREEZING SPRAY WARNING UNTIL 1 AM EST THURSDAY FOR LSZ246-
247.
GALE WARNING UNTIL 7 AM EST THURSDAY FOR LSZ249>251.
LAKE MICHIGAN...
HEAVY FREEZING SPRAY WARNING UNTIL 1 AM EST THURSDAY FOR LMZ221-
248-250.
GALE WARNING UNTIL 1 AM EST THURSDAY FOR LMZ221-250.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
218 PM EST WED DEC 31 2014
LATEST UPDATE...
HYDRO
.SYNOPSIS...
ISSUED AT 1210 PM EST WED DEC 31 2014
SNOW SHOWERS WILL CONTINUE THROUGH THIS AFTERNOON BUT
ACCUMULATIONS WILL BE LIGHT. IT WILL STAY COLD AND WINDY TONIGHT.
A STORM WITH SNOW OR MIXED PRECIPITATION IS EXPECTED THIS WEEKEND.
&&
.UPDATE...
ISSUED AT 1210 PM EST WED DEC 31 2014
BASED ON CURRENT RADAR TRENDS AND MODEL GUIDANCE...THE POPS HAVE
BEEN INCREASED FOR THIS AFTERNOON AS WEST FLOW LAKE EFFECT SNOW
SHOWERS WILL CONTINUE.
UPDATE ISSUED AT 611 AM EST WED DEC 31 2014
I DISPLACED THE HIGHEST POP AND GREATEST SNOW ACCUMULATIONS INLAND
TO NEAR US-131 INSTEAD OF NEAR THE LAKE SHORE. CURRENTLY (6 AM)
THE LOWEST REPORTED VISIBILITIES ARE LOCATIONS NEAR US-131
(RQB...FFX...GRR TO LAN ) AND NOT BY THE LAKE SHORE. ALL STATIONS
NEAR THE LAKE SHORE HAVE HAD VISIBILITIES GREATER THAN 6 MILES SINCE
I CAME TO WORK AROUND MIDNIGHT. THE HRRR AND NAM ALSO SHOW THE
LOCATION OF THE HIGHEST ACCUMULATION NEAR AND NORTH OF I-96...BY
US-131 INTO THIS AFTERNOON. THE REASON FOR THIS IS THE WINDS IN
THE CLOUD LAYER INCREASING TO 40 KNOT. THOSE STRONG OF WIND ALWAYS
BLOW THE HEAVIEST SNOW SHOWERS INLAND. THERE SHOULD BE DECREASE IN
THE SNOW SHOWER ACTIVITY THIS AFTERNOON AS MID LEVEL TEMPERATURES
START TO RISE AND SHORTWAVE CAUSING THE CURRENT BUST OF ACTIVITY
MOVES EAST OF THE AREA.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 326 AM EST WED DEC 31 2014
FORECAST CONCERNS DEAL WITH LAKE EFFECT SNOW SHOWERS TODAY AND WINDS
THIS AFTERNOON.
RADAR SHOWS SHSN CONTINUING ACROSS THE WESTERN CWA AS THE CORE OF
THE COLD AIR MOVES THROUGH. H8 TEMPS NEAR -20C ARE PROVIDING GOOD
INSTABILITY OVER THE LAKE. EVEN THOUGH MOISTURE IS SHALLOW...WE/RE
SEEING SOME LIGHT SNOW. ACCUMS ARE ONLY A FEW TENTHS OF AN INCH
THOUGH DUE TO A LOW AND SHALLOW DGZ WITH LIMITED LIFT WITHIN THAT
ZONE. AS THE CORE OF THE COLD AIR MOVES EAST...THE SHSN WILL
DIMINISH LATE TODAY. WINDS WILL ALSO INCREASE AS THE NEXT COLD FRONT
DROPS SOUTH INTO THE NORTHERN GREAT LAKES. WIND PROFILES IN THE FAR
NW CWA SUGGEST WE COULD SEE WIND GUSTS IN EXCESS OF 45 KTS...SO WE
HAVE ISSUED A WIND ADVISORY FOR MASON COUNTY FROM THIS AFTERNOON
THROUGH TONIGHT.
A STRONG SHORT WAVE WILL ACCOMPANY THE COLD FRONT THURSDAY AND
THURSDAY NIGHT AS IT MOVES OVER NORTHERN LOWER MICHIGAN. SOME LIGHT
SNOW IS POSSIBLE WITH THE SYSTEM WITH BOUNDARY LAYER RH AROUND 90
PERCENT. OVERALL MOISTURE IS DEEPER WITH THIS SYSTEM BUT THE MAIN
AREA OF LIFT IS WELL BELOW THE DGZ WHICH IS PROGGED AOA 10K FT. THIS
WILL CUT DOWN ON ACCUMS QUITE A BIT. PLACED HIGHEST POPS OVER THE
NRN CWA.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 326 AM EST WED DEC 31 2014
MY FORECAST CONFIDENCE FOR A SYSTEM MOVING THROUGH SOUTHERN LOWER
MICHIGAN SATURDAY INTO EARLY SUNDAY CONTINUES TO INCREASE. IT IS
LOOKING MORE AND MORE LIKE MOSTLY SNOW...WITH MIXED PRECIPITATION IN
THE I-69 AREA SATURDAY EVENING. BEHIND THAT MUCH COLDER AIR MOVES IN
THAT WILL REMAIN IN PLACE MOST OF NEXT WEEK. LAKE EFFECT SNOW WILL
BE ACTIVE THROUGH THE SUNDAY TO TUESDAY TIME FRAME.
THE SATURDAY STORM SYSTEM RESULTS FROM THE PHASING OF THREE SYSTEMS.
WHAT PHASES IS THE CLOSED UPPER LOW CURRENTLY OVER THE SOUTHWEST
UNITED STATES....AND A DIGGING ARCTIC SHORTWAVE AND A PACIFIC
SHORTWAVE. THE PHASING OF THESE THREE SYSTEMS HAPPENS ON SATURDAY AS
THE STORM APPROACHES OUR AREA. THERE IS STILL SOME QUESTION AS TO
THE TRACK AND HOW MUCH WARM AIR COMES WEST OF THE SYSTEM. HOWEVER...
UNLIKE THE SYSTEM ON CHRISTMAS...THIS SYSTEM HAS A LOT OF COLD AIR
TO WORK WITH SO THERE SHOULD BE MUCH LESS OF AN ISSUE WITH GETTING A
SIGNIFICANT AMOUNT OF THE STORMS PRECIPITATION IN OUR CWA TO BE SNOW
GIVEN THE TRACK IS THROUGH SOUTHEAST MICHIGAN. I STILL ALLOWED FOR
SLEET...FREEZING RAIN TO MIX IN OVER MOST AREAS NEAR AND EAST OF
GRAND RAPIDS SATURDAY AFTERNOON. THIS WILL HAVE TO BE ADJUSTED AS
THE STORM TRACK BECOMES MORE CERTAIN.
BEHIND THE SYSTEM WE TO HAVE THE ISSUE WITH SPLITTING POLAR VORTEX.
THAT WILL ASSURES A SIGNIFICANT PUSH OF MUCH COLDER AIR BEHIND THE
SYSTEM SATURDAY NIGHT. BOTH THE ECMWF AND GFS HAVE 850 TEMPS
FALLING TO NEAR -25C IN THE MONDAY-TUESDAY TIME FRAME. GIVEN THAT
AMOUNT OF COLD AIR AND A SERIES OF SHORTWAVES ON THE NORTHERN BRANCH
OF THE POLAR JET..LITTLE QUESTION IN MY MIND...LAKE EFFECT SNOW WILL
BE ON-GOING THROUGH THE MIDDLE OF NEXT WEEK.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 326 AM EST WED DEC 31 2014
FORECAST CONCERNS DEAL WITH LAKE EFFECT SNOW SHOWERS TODAY AND WINDS
THIS AFTERNOON.
RADAR SHOWS SHSN CONTINUING ACROSS THE WESTERN CWA AS THE CORE OF
THE COLD AIR MOVES THROUGH. H8 TEMPS NEAR -20C ARE PROVIDING GOOD
INSTABILITY OVER THE LAKE. EVEN THOUGH MOISTURE IS SHALLOW...WE/RE
SEEING SOME LIGHT SNOW. ACCUMS ARE ONLY A FEW TENTHS OF AN INCH
THOUGH DUE TO A LOW AND SHALLOW DGZ WITH LIMITED LIFT WITHIN THAT
ZONE. AS THE CORE OF THE COLD AIR MOVES EAST...THE SHSN WILL
DIMINISH LATE TODAY. WINDS WILL ALSO INCREASE AS THE NEXT COLD FRONT
DROPS SOUTH INTO THE NORTHERN GREAT LAKES. WIND PROFILES IN THE FAR
NW CWA SUGGEST WE COULD SEE WIND GUSTS IN EXCESS OF 45 KTS...SO WE
HAVE ISSUED A WIND ADVISORY FOR MASON COUNTY FROM THIS AFTERNOON
THROUGH TONIGHT.
A STRONG SHORT WAVE WILL ACCOMPANY THE COLD FRONT THURSDAY AND
THURSDAY NIGHT AS IT MOVES OVER NORTHERN LOWER MICHIGAN. SOME LIGHT
SNOW IS POSSIBLE WITH THE SYSTEM WITH BOUNDARY LAYER RH AROUND 90
PERCENT. OVERALL MOISTURE IS DEEPER WITH THIS SYSTEM BUT THE MAIN
AREA OF LIFT IS WELL BELOW THE DGZ WHICH IS PROGGED AOA 10K FT. THIS
WILL CUT DOWN ON ACCUMS QUITE A BIT. PLACED HIGHEST POPS OVER THE
NRN CWA.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 326 AM EST WED DEC 31 2014
MY FORECAST CONFIDENCE FOR A SYSTEM MOVING THROUGH SOUTHERN LOWER
MICHIGAN SATURDAY INTO EARLY SUNDAY CONTINUES TO INCREASE. IT IS
LOOKING MORE AND MORE LIKE MOSTLY SNOW...WITH MIXED PRECIPITATION IN
THE I-69 AREA SATURDAY EVENING. BEHIND THAT MUCH COLDER AIR MOVES IN
THAT WILL REMAIN IN PLACE MOST OF NEXT WEEK. LAKE EFFECT SNOW WILL
BE ACTIVE THROUGH THE SUNDAY TO TUESDAY TIME FRAME.
THE SATURDAY STORM SYSTEM RESULTS FROM THE PHASING OF THREE SYSTEMS.
WHAT PHASES IS THE CLOSED UPPER LOW CURRENTLY OVER THE SOUTHWEST
UNITED STATES....AND A DIGGING ARCTIC SHORTWAVE AND A PACIFIC
SHORTWAVE. THE PHASING OF THESE THREE SYSTEMS HAPPENS ON SATURDAY AS
THE STORM APPROACHES OUR AREA. THERE IS STILL SOME QUESTION AS TO
THE TRACK AND HOW MUCH WARM AIR COMES WEST OF THE SYSTEM. HOWEVER...
UNLIKE THE SYSTEM ON CHRISTMAS...THIS SYSTEM HAS A LOT OF COLD AIR
TO WORK WITH SO THERE SHOULD BE MUCH LESS OF AN ISSUE WITH GETTING A
SIGNIFICANT AMOUNT OF THE STORMS PRECIPITATION IN OUR CWA TO BE SNOW
GIVEN THE TRACK IS THROUGH SOUTHEAST MICHIGAN. I STILL ALLOWED FOR
SLEET...FREEZING RAIN TO MIX IN OVER MOST AREAS NEAR AND EAST OF
GRAND RAPIDS SATURDAY AFTERNOON. THIS WILL HAVE TO BE ADJUSTED AS
THE STORM TRACK BECOMES MORE CERTAIN.
BEHIND THE SYSTEM WE TO HAVE THE ISSUE WITH SPLITTING POLAR VORTEX.
THAT WILL ASSURES A SIGNIFICANT PUSH OF MUCH COLDER AIR BEHIND THE
SYSTEM SATURDAY NIGHT. BOTH THE ECMWF AND GFS HAVE 850 TEMPS
FALLING TO NEAR -25C IN THE MONDAY-TUESDAY TIME FRAME. GIVEN THAT
AMOUNT OF COLD AIR AND A SERIES OF SHORTWAVES ON THE NORTHERN BRANCH
OF THE POLAR JET..LITTLE QUESTION IN MY MIND...LAKE EFFECT SNOW WILL
BE ON-GOING THROUGH THE MIDDLE OF NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1221 PM EST WED DEC 31 2014
MOSTLY MVFR CONDITIONS EXISTED ACROSS THE REGION EARLY THIS
AFTERNOON...HOWEVER SCATTERED AREAS OF IFR PERSISTED IN LAKE
EFFECT SNOW SHOWERS. NOT MUCH CHANGE IS EXPECTED UNTIL PERHAPS MID
THURSDAY MORNING. MEAN LOW LEVEL WINDS ARE EXPECTED TO REMAIN
240-260 AND THIS WILL FAVOR MKG AND GRR WITH PERIODIC SNOW SHOWERS
AND OCCASIONAL IFR VSBYS. DRIER AIR DOES NOT ARRIVE UNTIL THURSDAY
MORNING...WHEN THE FREQUENCY OF THE SNOW SHOWERS SHOULD FINALLY
DIMINISH. THE REST OF THE SW MI TAF SITES SHOULD SEE A MIX OF MVFR
AND VFR.
WSW WINDS WILL CONTINUE TO GUST 20-30 KNOTS THROUGH THE NEXT 24
HOURS.
&&
.MARINE...
ISSUED AT 1210 PM EST WED DEC 31 2014
KEPT THE MARINE HEADLINES UNCHANGED. ADDED FREEZING SPRAY TO THE
FORECAST BUT DID NOT ISSUE ADVISORY OR WARNING BASED ON
COORDINATION WITH SURROUNDING OFFICES.
&&
.HYDROLOGY...
ISSUED AT 218 PM EST WED DEC 31 2014
ICE DEVELOPMENT ON SOME RIVERS AND STREAMS OVER THE NEXT COUPLE
OF DAYS. WARMER TEMPS EXPECTED FRI-SUN WITH DAYTIME HIGHS IN THE
UPPER 20S TO LOWER 30S. ANOTHER SHOT OF ARCTIC AIR ARRIVES LATE IN
THE WEEKEND WITH LOWS SUNDAY NIGHT IN THE SINGLE DIGITS. HIGHS
ONLY IN THE TEENS ON MONDAY.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WIND ADVISORY UNTIL 6 AM EST THURSDAY FOR MIZ037.
LM...GALE WARNING UNTIL 6 AM EST THURSDAY FOR LMZ844>849.
&&
$$
UPDATE...OSTUNO
SYNOPSIS...OSTUNO
SHORT TERM...93
LONG TERM...WDM
AVIATION...JK
HYDROLOGY...EBW
MARINE...OSTUNO
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1221 PM EST WED DEC 31 2014
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 1210 PM EST WED DEC 31 2014
SNOW SHOWERS WILL CONTINUE THROUGH THIS AFTERNOON BUT
ACCUMULATIONS WILL BE LIGHT. IT WILL STAY COLD AND WINDY TONIGHT.
A STORM WITH SNOW OR MIXED PRECIPITATION IS EXPECTED THIS WEEKEND.
&&
.UPDATE...
ISSUED AT 1210 PM EST WED DEC 31 2014
BASED ON CURRENT RADAR TRENDS AND MODEL GUIDANCE...THE POPS HAVE
BEEN INCREASED FOR THIS AFTERNOON AS WEST FLOW LAKE EFFECT SNOW
SHOWERS WILL CONTINUE.
UPDATE ISSUED AT 611 AM EST WED DEC 31 2014
I DISPLACED THE HIGHEST POP AND GREATEST SNOW ACCUMULATIONS INLAND
TO NEAR US-131 INSTEAD OF NEAR THE LAKE SHORE. CURRENTLY (6 AM)
THE LOWEST REPORTED VISIBILITIES ARE LOCATIONS NEAR US-131
(RQB...FFX...GRR TO LAN ) AND NOT BY THE LAKE SHORE. ALL STATIONS
NEAR THE LAKE SHORE HAVE HAD VISIBILITIES GREATER THAN 6 MILES SINCE
I CAME TO WORK AROUND MIDNIGHT. THE HRRR AND NAM ALSO SHOW THE
LOCATION OF THE HIGHEST ACCUMULATION NEAR AND NORTH OF I-96...BY
US-131 INTO THIS AFTERNOON. THE REASON FOR THIS IS THE WINDS IN
THE CLOUD LAYER INCREASING TO 40 KNOT. THOSE STRONG OF WIND ALWAYS
BLOW THE HEAVIEST SNOW SHOWERS INLAND. THERE SHOULD BE DECREASE IN
THE SNOW SHOWER ACTIVITY THIS AFTERNOON AS MID LEVEL TEMPERATURES
START TO RISE AND SHORTWAVE CAUSING THE CURRENT BUST OF ACTIVITY
MOVES EAST OF THE AREA.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 326 AM EST WED DEC 31 2014
FORECAST CONCERNS DEAL WITH LAKE EFFECT SNOW SHOWERS TODAY AND WINDS
THIS AFTERNOON.
RADAR SHOWS SHSN CONTINUING ACROSS THE WESTERN CWA AS THE CORE OF
THE COLD AIR MOVES THROUGH. H8 TEMPS NEAR -20C ARE PROVIDING GOOD
INSTABILITY OVER THE LAKE. EVEN THOUGH MOISTURE IS SHALLOW...WE/RE
SEEING SOME LIGHT SNOW. ACCUMS ARE ONLY A FEW TENTHS OF AN INCH
THOUGH DUE TO A LOW AND SHALLOW DGZ WITH LIMITED LIFT WITHIN THAT
ZONE. AS THE CORE OF THE COLD AIR MOVES EAST...THE SHSN WILL
DIMINISH LATE TODAY. WINDS WILL ALSO INCREASE AS THE NEXT COLD FRONT
DROPS SOUTH INTO THE NORTHERN GREAT LAKES. WIND PROFILES IN THE FAR
NW CWA SUGGEST WE COULD SEE WIND GUSTS IN EXCESS OF 45 KTS...SO WE
HAVE ISSUED A WIND ADVISORY FOR MASON COUNTY FROM THIS AFTERNOON
THROUGH TONIGHT.
A STRONG SHORT WAVE WILL ACCOMPANY THE COLD FRONT THURSDAY AND
THURSDAY NIGHT AS IT MOVES OVER NORTHERN LOWER MICHIGAN. SOME LIGHT
SNOW IS POSSIBLE WITH THE SYSTEM WITH BOUNDARY LAYER RH AROUND 90
PERCENT. OVERALL MOISTURE IS DEEPER WITH THIS SYSTEM BUT THE MAIN
AREA OF LIFT IS WELL BELOW THE DGZ WHICH IS PROGGED AOA 10K FT. THIS
WILL CUT DOWN ON ACCUMS QUITE A BIT. PLACED HIGHEST POPS OVER THE
NRN CWA.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 326 AM EST WED DEC 31 2014
MY FORECAST CONFIDENCE FOR A SYSTEM MOVING THROUGH SOUTHERN LOWER
MICHIGAN SATURDAY INTO EARLY SUNDAY CONTINUES TO INCREASE. IT IS
LOOKING MORE AND MORE LIKE MOSTLY SNOW...WITH MIXED PRECIPITATION IN
THE I-69 AREA SATURDAY EVENING. BEHIND THAT MUCH COLDER AIR MOVES IN
THAT WILL REMAIN IN PLACE MOST OF NEXT WEEK. LAKE EFFECT SNOW WILL
BE ACTIVE THROUGH THE SUNDAY TO TUESDAY TIME FRAME.
THE SATURDAY STORM SYSTEM RESULTS FROM THE PHASING OF THREE SYSTEMS.
WHAT PHASES IS THE CLOSED UPPER LOW CURRENTLY OVER THE SOUTHWEST
UNITED STATES....AND A DIGGING ARCTIC SHORTWAVE AND A PACIFIC
SHORTWAVE. THE PHASING OF THESE THREE SYSTEMS HAPPENS ON SATURDAY AS
THE STORM APPROACHES OUR AREA. THERE IS STILL SOME QUESTION AS TO
THE TRACK AND HOW MUCH WARM AIR COMES WEST OF THE SYSTEM. HOWEVER...
UNLIKE THE SYSTEM ON CHRISTMAS...THIS SYSTEM HAS A LOT OF COLD AIR
TO WORK WITH SO THERE SHOULD BE MUCH LESS OF AN ISSUE WITH GETTING A
SIGNIFICANT AMOUNT OF THE STORMS PRECIPITATION IN OUR CWA TO BE SNOW
GIVEN THE TRACK IS THROUGH SOUTHEAST MICHIGAN. I STILL ALLOWED FOR
SLEET...FREEZING RAIN TO MIX IN OVER MOST AREAS NEAR AND EAST OF
GRAND RAPIDS SATURDAY AFTERNOON. THIS WILL HAVE TO BE ADJUSTED AS
THE STORM TRACK BECOMES MORE CERTAIN.
BEHIND THE SYSTEM WE TO HAVE THE ISSUE WITH SPLITTING POLAR VORTEX.
THAT WILL ASSURES A SIGNIFICANT PUSH OF MUCH COLDER AIR BEHIND THE
SYSTEM SATURDAY NIGHT. BOTH THE ECMWF AND GFS HAVE 850 TEMPS
FALLING TO NEAR -25C IN THE MONDAY-TUESDAY TIME FRAME. GIVEN THAT
AMOUNT OF COLD AIR AND A SERIES OF SHORTWAVES ON THE NORTHERN BRANCH
OF THE POLAR JET..LITTLE QUESTION IN MY MIND...LAKE EFFECT SNOW WILL
BE ON-GOING THROUGH THE MIDDLE OF NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1221 PM EST WED DEC 31 2014
MOSTLY MVFR CONDITIONS EXISTED ACROSS THE REGION EARLY THIS
AFTERNOON...HOWEVER SCATTERED AREAS OF IFR PERSISTED IN LAKE
EFFECT SNOW SHOWERS. NOT MUCH CHANGE IS EXPECTED UNTIL PERHAPS MID
THURSDAY MORNING. MEAN LOW LEVEL WINDS ARE EXPECTED TO REMAIN
240-260 AND THIS WILL FAVOR MKG AND GRR WITH PERIODIC SNOW SHOWERS
AND OCCASIONAL IFR VSBYS. DRIER AIR DOES NOT ARRIVE UNTIL THURSDAY
MORNING...WHEN THE FREQUENCY OF THE SNOW SHOWERS SHOULD FINALLY
DIMINISH. THE REST OF THE SW MI TAF SITES SHOULD SEE A MIX OF MVFR
AND VFR.
WSW WINDS WILL CONTINUE TO GUST 20-30 KNOTS THROUGH THE NEXT 24
HOURS.
&&
.MARINE...
ISSUED AT 1210 PM EST WED DEC 31 2014
KEPT THE MARINE HEADLINES UNCHANGED. ADDED FREEZING SPRAY TO THE
FORECAST BUT DID NOT ISSUE ADVISORY OR WARNING BASED ON
COORDINATION WITH SURROUNDING OFFICES.
&&
.HYDROLOGY...
ISSUED AT 326 AM EST WED DEC 31 2014
COLD TEMPS WILL CONTINUE TO AID IN ICE DEVELOPMENT ON AREA
WATERWAYS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WIND ADVISORY UNTIL 6 AM EST THURSDAY FOR MIZ037.
LM...GALE WARNING UNTIL 6 AM EST THURSDAY FOR LMZ844>849.
&&
$$
UPDATE...OSTUNO
SYNOPSIS...OSTUNO
SHORT TERM...93
LONG TERM...WDM
AVIATION...JK
HYDROLOGY...93
MARINE...OSTUNO
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1210 PM EST WED DEC 31 2014
LATEST UPDATE...
UPDATE/SYNOPSIS/MARINE
.SYNOPSIS...
ISSUED AT 1210 PM EST WED DEC 31 2014
SNOW SHOWERS WILL CONTINUE THROUGH THIS AFTERNOON BUT
ACCUMULATIONS WILL BE LIGHT. IT WILL STAY COLD AND WINDY TONIGHT.
A STORM WITH SNOW OR MIXED PRECIPITATION IS EXPECTED THIS WEEKEND.
&&
.UPDATE...
ISSUED AT 1210 PM EST WED DEC 31 2014
BASED ON CURRENT RADAR TRENDS AND MODEL GUIDANCE...THE POPS HAVE
BEEN INCREASED FOR THIS AFTERNOON AS WEST FLOW LAKE EFFECT SNOW
SHOWERS WILL CONTINUE.
UPDATE ISSUED AT 611 AM EST WED DEC 31 2014
I DISPLACED THE HIGHEST POP AND GREATEST SNOW ACCUMULATIONS INLAND
TO NEAR US-131 INSTEAD OF NEAR THE LAKE SHORE. CURRENTLY (6 AM)
THE LOWEST REPORTED VISIBILITIES ARE LOCATIONS NEAR US-131
(RQB...FFX...GRR TO LAN ) AND NOT BY THE LAKE SHORE. ALL STATIONS
NEAR THE LAKE SHORE HAVE HAD VISIBILITIES GREATER THAN 6 MILES SINCE
I CAME TO WORK AROUND MIDNIGHT. THE HRRR AND NAM ALSO SHOW THE
LOCATION OF THE HIGHEST ACCUMULATION NEAR AND NORTH OF I-96...BY
US-131 INTO THIS AFTERNOON. THE REASON FOR THIS IS THE WINDS IN
THE CLOUD LAYER INCREASING TO 40 KNOT. THOSE STRONG OF WIND ALWAYS
BLOW THE HEAVIEST SNOW SHOWERS INLAND. THERE SHOULD BE DECREASE IN
THE SNOW SHOWER ACTIVITY THIS AFTERNOON AS MID LEVEL TEMPERATURES
START TO RISE AND SHORTWAVE CAUSING THE CURRENT BUST OF ACTIVITY
MOVES EAST OF THE AREA.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 326 AM EST WED DEC 31 2014
FORECAST CONCERNS DEAL WITH LAKE EFFECT SNOW SHOWERS TODAY AND WINDS
THIS AFTERNOON.
RADAR SHOWS SHSN CONTINUING ACROSS THE WESTERN CWA AS THE CORE OF
THE COLD AIR MOVES THROUGH. H8 TEMPS NEAR -20C ARE PROVIDING GOOD
INSTABILITY OVER THE LAKE. EVEN THOUGH MOISTURE IS SHALLOW...WE/RE
SEEING SOME LIGHT SNOW. ACCUMS ARE ONLY A FEW TENTHS OF AN INCH
THOUGH DUE TO A LOW AND SHALLOW DGZ WITH LIMITED LIFT WITHIN THAT
ZONE. AS THE CORE OF THE COLD AIR MOVES EAST...THE SHSN WILL
DIMINISH LATE TODAY. WINDS WILL ALSO INCREASE AS THE NEXT COLD FRONT
DROPS SOUTH INTO THE NORTHERN GREAT LAKES. WIND PROFILES IN THE FAR
NW CWA SUGGEST WE COULD SEE WIND GUSTS IN EXCESS OF 45 KTS...SO WE
HAVE ISSUED A WIND ADVISORY FOR MASON COUNTY FROM THIS AFTERNOON
THROUGH TONIGHT.
A STRONG SHORT WAVE WILL ACCOMPANY THE COLD FRONT THURSDAY AND
THURSDAY NIGHT AS IT MOVES OVER NORTHERN LOWER MICHIGAN. SOME LIGHT
SNOW IS POSSIBLE WITH THE SYSTEM WITH BOUNDARY LAYER RH AROUND 90
PERCENT. OVERALL MOISTURE IS DEEPER WITH THIS SYSTEM BUT THE MAIN
AREA OF LIFT IS WELL BELOW THE DGZ WHICH IS PROGGED AOA 10K FT. THIS
WILL CUT DOWN ON ACCUMS QUITE A BIT. PLACED HIGHEST POPS OVER THE
NRN CWA.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 326 AM EST WED DEC 31 2014
MY FORECAST CONFIDENCE FOR A SYSTEM MOVING THROUGH SOUTHERN LOWER
MICHIGAN SATURDAY INTO EARLY SUNDAY CONTINUES TO INCREASE. IT IS
LOOKING MORE AND MORE LIKE MOSTLY SNOW...WITH MIXED PRECIPITATION IN
THE I-69 AREA SATURDAY EVENING. BEHIND THAT MUCH COLDER AIR MOVES IN
THAT WILL REMAIN IN PLACE MOST OF NEXT WEEK. LAKE EFFECT SNOW WILL
BE ACTIVE THROUGH THE SUNDAY TO TUESDAY TIME FRAME.
THE SATURDAY STORM SYSTEM RESULTS FROM THE PHASING OF THREE SYSTEMS.
WHAT PHASES IS THE CLOSED UPPER LOW CURRENTLY OVER THE SOUTHWEST
UNITED STATES....AND A DIGGING ARCTIC SHORTWAVE AND A PACIFIC
SHORTWAVE. THE PHASING OF THESE THREE SYSTEMS HAPPENS ON SATURDAY AS
THE STORM APPROACHES OUR AREA. THERE IS STILL SOME QUESTION AS TO
THE TRACK AND HOW MUCH WARM AIR COMES WEST OF THE SYSTEM. HOWEVER...
UNLIKE THE SYSTEM ON CHRISTMAS...THIS SYSTEM HAS A LOT OF COLD AIR
TO WORK WITH SO THERE SHOULD BE MUCH LESS OF AN ISSUE WITH GETTING A
SIGNIFICANT AMOUNT OF THE STORMS PRECIPITATION IN OUR CWA TO BE SNOW
GIVEN THE TRACK IS THROUGH SOUTHEAST MICHIGAN. I STILL ALLOWED FOR
SLEET...FREEZING RAIN TO MIX IN OVER MOST AREAS NEAR AND EAST OF
GRAND RAPIDS SATURDAY AFTERNOON. THIS WILL HAVE TO BE ADJUSTED AS
THE STORM TRACK BECOMES MORE CERTAIN.
BEHIND THE SYSTEM WE TO HAVE THE ISSUE WITH SPLITTING POLAR VORTEX.
THAT WILL ASSURES A SIGNIFICANT PUSH OF MUCH COLDER AIR BEHIND THE
SYSTEM SATURDAY NIGHT. BOTH THE ECMWF AND GFS HAVE 850 TEMPS
FALLING TO NEAR -25C IN THE MONDAY-TUESDAY TIME FRAME. GIVEN THAT
AMOUNT OF COLD AIR AND A SERIES OF SHORTWAVES ON THE NORTHERN BRANCH
OF THE POLAR JET..LITTLE QUESTION IN MY MIND...LAKE EFFECT SNOW WILL
BE ON-GOING THROUGH THE MIDDLE OF NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 611 AM EST WED DEC 31 2014
FOR THE MOST PART MVFR CEILING PREVAIL AT MOST TAF SITES AT 11Z THIS
MORNING. SNOW SHOWERS HAVE BROUGHT IFR VISIBILITIES TO GRR....LAN
AND JXN OVER THE PAST FEW HOURS BUT NOT MKG...AZO OR BTL. I EXPECT
THE SNOW SHOWER ACTIVITY TO CONTINUE INTO LATE MORNING BEFORE
DECREASING SOME AS DRIER AIR MOVES IN. I WOULD ALSO EXPECT THE
I-96 TAF SITES... EXCEPT FOR MKG (TO CLOSE TO THE LAKE SHORE WITH
THE STRONG WINDS IN THE CLOUDS TODAY) WILL CONTINUE TO SEE
OCCASIONAL IFR VISIBILITIES IN SNOW SHOWERS INTO LATE MORNING OR
EARLY AFTERNOON. VFR CONDITIONS WITH STRONG WEST WINDS WILL
PREVAIL THIS AFTERNOON. ADDITIONAL LIGHT SNOW SHOWERS WILL
REDEVELOP AFTER 06Z AS ANOTHER SHORTWAVE MOVES INTO THE AREA.
&&
.MARINE...
ISSUED AT 1210 PM EST WED DEC 31 2014
KEPT THE MARINE HEADLINES UNCHANGED. ADDED FREEZING SPRAY TO THE
FORECAST BUT DID NOT ISSUE ADVISORY OR WARNING BASED ON
COORDINATION WITH SURROUNDING OFFICES.
&&
.HYDROLOGY...
ISSUED AT 326 AM EST WED DEC 31 2014
COLD TEMPS WILL CONTINUE TO AID IN ICE DEVELOPMENT ON AREA
WATERWAYS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WIND ADVISORY UNTIL 6 AM EST THURSDAY FOR MIZ037.
LM...SMALL CRAFT ADVISORY UNTIL NOON EST TODAY FOR LMZ844>849.
GALE WARNING UNTIL 6 AM EST THURSDAY FOR LMZ844>849.
&&
$$
UPDATE...OSTUNO
SYNOPSIS...OSTUNO
SHORT TERM...93
LONG TERM...WDM
AVIATION...WDM
HYDROLOGY...93
MARINE...OSTUNO
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
613 AM EST WED DEC 31 2014
LATEST UPDATE...
UPDATE/AVIATION
.SYNOPSIS...
ISSUED AT 326 AM EST WED DEC 31 2014
LIGHT LAKE EFFECT SNOW SHOWERS WILL CONTINUE THIS MORNING AND THEN
DIMINISH LATE THIS AFTERNOON AND EVENING AS THE CORE OF THE COLD AIR
ALOFT MOVES EAST. BREEZY CONDITIONS WILL DEVELOP BY THIS AFTERNOON
ESPECIALLY NEAR THE LAKE NORTH OF US-10. APPARENT TEMPERATURES WILL
FALL TO AROUND 0 TONIGHT. ANOTHER COLD FRONT WILL DROP SOUTH
THURSDAY NIGHT PROVIDING ANOTHER OPPORTUNITY FOR LIGHT SNOW SHOWERS.
&&
.UPDATE...
ISSUED AT 611 AM EST WED DEC 31 2014
I DISPLACED THE HIGHEST POP AND GREATEST SNOW ACCUMULATIONS INLAND
TO NEAR US-131 INSTEAD OF NEAR THE LAKE SHORE. CURRENTLY (6 AM)
THE LOWEST REPORTED VISIBILITIES ARE LOCATIONS NEAR US-131
(RQB...FFX...GRR TO LAN ) AND NOT BY THE LAKE SHORE. ALL STATIONS
NEAR THE LAKE SHORE HAVE HAD VISIBILITIES GREATER THAN 6 MILES SINCE
I CAME TO WORK AROUND MIDNIGHT. THE HRRR AND NAM ALSO SHOW THE
LOCATION OF THE HIGHEST ACCUMULATION NEAR AND NORTH OF I-96...BY
US-131 INTO THIS AFTERNOON. THE REASON FOR THIS IS THE WINDS IN
THE CLOUD LAYER INCREASING TO 40 KNOT. THOSE STRONG OF WIND ALWAYS
BLOW THE HEAVIEST SNOW SHOWERS INLAND. THERE SHOULD BE DECREASE IN
THE SNOW SHOWER ACTIVITY THIS AFTERNOON AS MID LEVEL TEMPERATURES
START TO RISE AND SHORTWAVE CAUSING THE CURRENT BUST OF ACTIVITY
MOVES EAST OF THE AREA.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 326 AM EST WED DEC 31 2014
FORECAST CONCERNS DEAL WITH LAKE EFFECT SNOW SHOWERS TODAY AND WINDS
THIS AFTERNOON.
RADAR SHOWS SHSN CONTINUING ACROSS THE WESTERN CWA AS THE CORE OF
THE COLD AIR MOVES THROUGH. H8 TEMPS NEAR -20C ARE PROVIDING GOOD
INSTABILITY OVER THE LAKE. EVEN THOUGH MOISTURE IS SHALLOW...WE/RE
SEEING SOME LIGHT SNOW. ACCUMS ARE ONLY A FEW TENTHS OF AN INCH
THOUGH DUE TO A LOW AND SHALLOW DGZ WITH LIMITED LIFT WITHIN THAT
ZONE. AS THE CORE OF THE COLD AIR MOVES EAST...THE SHSN WILL
DIMINISH LATE TODAY. WINDS WILL ALSO INCREASE AS THE NEXT COLD FRONT
DROPS SOUTH INTO THE NORTHERN GREAT LAKES. WIND PROFILES IN THE FAR
NW CWA SUGGEST WE COULD SEE WIND GUSTS IN EXCESS OF 45 KTS...SO WE
HAVE ISSUED A WIND ADVISORY FOR MASON COUNTY FROM THIS AFTERNOON
THROUGH TONIGHT.
A STRONG SHORT WAVE WILL ACCOMPANY THE COLD FRONT THURSDAY AND
THURSDAY NIGHT AS IT MOVES OVER NORTHERN LOWER MICHIGAN. SOME LIGHT
SNOW IS POSSIBLE WITH THE SYSTEM WITH BOUNDARY LAYER RH AROUND 90
PERCENT. OVERALL MOISTURE IS DEEPER WITH THIS SYSTEM BUT THE MAIN
AREA OF LIFT IS WELL BELOW THE DGZ WHICH IS PROGGED AOA 10K FT. THIS
WILL CUT DOWN ON ACCUMS QUITE A BIT. PLACED HIGHEST POPS OVER THE
NRN CWA.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 326 AM EST WED DEC 31 2014
MY FORECAST CONFIDENCE FOR A SYSTEM MOVING THROUGH SOUTHERN LOWER
MICHIGAN SATURDAY INTO EARLY SUNDAY CONTINUES TO INCREASE. IT IS
LOOKING MORE AND MORE LIKE MOSTLY SNOW...WITH MIXED PRECIPITATION IN
THE I-69 AREA SATURDAY EVENING. BEHIND THAT MUCH COLDER AIR MOVES IN
THAT WILL REMAIN IN PLACE MOST OF NEXT WEEK. LAKE EFFECT SNOW WILL
BE ACTIVE THROUGH THE SUNDAY TO TUESDAY TIME FRAME.
THE SATURDAY STORM SYSTEM RESULTS FROM THE PHASING OF THREE SYSTEMS.
WHAT PHASES IS THE CLOSED UPPER LOW CURRENTLY OVER THE SOUTHWEST
UNITED STATES....AND A DIGGING ARCTIC SHORTWAVE AND A PACIFIC
SHORTWAVE. THE PHASING OF THESE THREE SYSTEMS HAPPENS ON SATURDAY AS
THE STORM APPROACHES OUR AREA. THERE IS STILL SOME QUESTION AS TO
THE TRACK AND HOW MUCH WARM AIR COMES WEST OF THE SYSTEM. HOWEVER...
UNLIKE THE SYSTEM ON CHRISTMAS...THIS SYSTEM HAS A LOT OF COLD AIR
TO WORK WITH SO THERE SHOULD BE MUCH LESS OF AN ISSUE WITH GETTING A
SIGNIFICANT AMOUNT OF THE STORMS PRECIPITATION IN OUR CWA TO BE SNOW
GIVEN THE TRACK IS THROUGH SOUTHEAST MICHIGAN. I STILL ALLOWED FOR
SLEET...FREEZING RAIN TO MIX IN OVER MOST AREAS NEAR AND EAST OF
GRAND RAPIDS SATURDAY AFTERNOON. THIS WILL HAVE TO BE ADJUSTED AS
THE STORM TRACK BECOMES MORE CERTAIN.
BEHIND THE SYSTEM WE TO HAVE THE ISSUE WITH SPLITTING POLAR VORTEX.
THAT WILL ASSURES A SIGNIFICANT PUSH OF MUCH COLDER AIR BEHIND THE
SYSTEM SATURDAY NIGHT. BOTH THE ECMWF AND GFS HAVE 850 TEMPS
FALLING TO NEAR -25C IN THE MONDAY-TUESDAY TIME FRAME. GIVEN THAT
AMOUNT OF COLD AIR AND A SERIES OF SHORTWAVES ON THE NORTHERN BRANCH
OF THE POLAR JET..LITTLE QUESTION IN MY MIND...LAKE EFFECT SNOW WILL
BE ON-GOING THROUGH THE MIDDLE OF NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 611 AM EST WED DEC 31 2014
FOR THE MOST PART MVFR CEILING PREVAIL AT MOST TAF SITES AT 11Z THIS
MORNING. SNOW SHOWERS HAVE BROUGHT IFR VISIBILITIES TO GRR....LAN
AND JXN OVER THE PAST FEW HOURS BUT NOT MKG...AZO OR BTL. I EXPECT
THE SNOW SHOWER ACTIVITY TO CONTINUE INTO LATE MORNING BEFORE
DECREASING SOME AS DRIER AIR MOVES IN. I WOULD ALSO EXPECT THE
I-96 TAF SITES... EXCEPT FOR MKG (TO CLOSE TO THE LAKE SHORE WITH
THE STRONG WINDS IN THE CLOUDS TODAY) WILL CONTINUE TO SEE
OCCASIONAL IFR VISIBILITIES IN SNOW SHOWERS INTO LATE MORNING OR
EARLY AFTERNOON. VFR CONDITIONS WITH STRONG WEST WINDS WILL
PREVAIL THIS AFTERNOON. ADDITIONAL LIGHT SNOW SHOWERS WILL
REDEVELOP AFTER 06Z AS ANOTHER SHORTWAVE MOVES INTO THE AREA.
&&
.MARINE...
ISSUED AT 326 AM EST WED DEC 31 2014
EXTENDED THE SCA THROUGH THIS MORNING AND ISSUED A GALE WARNING FROM
NOON THROUGH TONIGHT. WINDS WILL INCREASE TO 40 KTS BY THIS EVENING
AS DEEP MIXING DEVELOPS IN THE WAKE OF THE COLD FRONT.
&&
.HYDROLOGY...
ISSUED AT 326 AM EST WED DEC 31 2014
COLD TEMPS WILL CONTINUE TO AID IN ICE DEVELOPMENT ON AREA
WATERWAYS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WIND ADVISORY FROM NOON TODAY TO 6 AM EST THURSDAY FOR MIZ037.
LM...SMALL CRAFT ADVISORY UNTIL NOON EST TODAY FOR LMZ844>849.
GALE WARNING FROM NOON TODAY TO 6 AM EST THURSDAY FOR LMZ844>849.
&&
$$
UPDATE...WDM
SYNOPSIS...93
SHORT TERM...93
LONG TERM...WDM
AVIATION...WDM
HYDROLOGY...93
MARINE...93
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
359 AM EST WED DEC 31 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 427 PM EST TUE DEC 30 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A PROMINENT MID/UPPER LEVEL
RIDGE FROM THE ERN PACIFIC INTO BC AND A TROUGH OVER NE CANADA
RESULTING IN NNW FLOW TOWARD NRN ONTARIO AND THE NRN LAKES. A
SHORTWAVE TROUGH AXIS EXTENDED FROM JAMES BAY INTO SE NORTH DAKOTA.
WITH ONLY WEAK FORCING AND LITTLE MOISTURE AVAILABLE...NO PCPN WAS
ASSOCIATED WITH THIS FEATURE. FURTHER UPSTREAM...A STRONGER SHRTWV
WAS MOVING THROUGH NRN SASK/MANITOBA. AT THE SFC...W TO WNW FLOW
PREVAILED ACROSS UPPER MI AND LAKE SUPERIOR AS 1048 MB HIGH PRES
CONTINUES TO SINK THROUGH THE NRN AND CNTRL PLAINS. EVEN WITH 850 MB
TEMPS NEAR -23C...SATELLITE/RADAR INDICATED ONLY LIGHT TO MODERATE
LES INTO NW UPPER MI AND EAST OF MUNISING AS INVERSION HEIGHTS
REMAINED NEAR 4K FT WITH VERY DRY AIR UPSTREAM.
TONIGHT...EXPECT WINDS TO GRADUALLY BACK TO SW AHEAD OF THE
SASK/MANITOBA SHRTWV WHICH WILL PUSH THE LES MOSTLY OFFSHORE.
HOWEVER...ADDITIONAL SNOWFALL AMOUNTS OF 1 TO 3 INCHES NW(KEWEENAW
AND 2 TO 4 INCHES NE (NE OF P53) ARE POSSIBLE. TEMPS FALLING OFF
INTO THE -7F TO -12F RANGE AND WINDS NEAR 10 MPH WILL DROP WIND
CHILLS INTO THE -20 TO -33 RANGE OVER THE INTERIOR WRN HALF WHERE
WIND CHILL ADVISORIES WILL REMAIN IN EFFECT.
WEDNESDAY...AS THE SHRTWV MOVES THROUGH THE NRN LAKES AND DRAGS A
WEAK TROUGH THE AREA...WINDS WILL VEER AGAIN FROM SW TO W BY
AFTERNOON. THIS WILL BRING THE LES INTO THE NRN KEWEENAW BY MIDDAY
AND INTO MUCH OF THE REST OF THE PENINSULA BY MID TO LATE AFTERNOON.
THE COMBINATION OF THE LES AND WIND GUSTS OVER 40 MPH WILL LEAD TO
VERY POOR VSBY WHICH WILL LINGER INTO THE EVENING...PROMPTING THE
ISSUANCE OF AN LES ADVY. ALTHOUGH THERE WILL BE A PERIOD OF DEEPER
MOISTURE THAT SHOULD INTENSIFY LES...THE SHIFTING WIND DIRECTIONS
SHOULD LIMIT OVERALL AMOUNTS TO THE 1 TO 3 INCH RANGE BY EVENING.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 427 PM EST TUE DEC 30 2014
UPPER AIR PATTERN STARTS OUT WITH TROUGHING ANCHORED OVER HUDSON BAY
AND ANOTHER MORE COMPACT TROUGH OVER DESERT SOUTHWEST OF CONUS. ONLY
RIDGING OF NOTE IS OVER THE EASTERN PACIFIC OCEAN INTO FAR WESTERN
CANADA. ATTENTION THIS WEEKEND WILL BE ON THE SOUTHWEST CONUS TROUGH.
MODELS CONTINUE TO FAVOR IDEA THAT AS STRONG JET ENERGY ADVANCES
AHEAD OF TROUGH...IT WILL EMERGE OVER THE SOUTHERN PLAINS ON
SATURDAY AND LIFT OVER THE GREAT LAKES ON SUNDAY. MEANWHILE...ANOTHER
SHORTWAVE WITHIN THE BASE OF LARGER TROUGHING OVER EASTERN CANADA
WILL WORK OVER THE UPPER GREAT LAKES. ONE OR BOTH OF THESE FEATURES
MAY BRING WIDESPREAD SNOW TO UPR MICHIGAN FRIDAY NIGHT THROUGH
SATURDAY NIGHT. THERE IS POTENTIAL THAT THE TWO FEATURES COULD
PHASE...THOUGH THAT IS NOT CERTAIN...AND THAT WOULD RESULT IN
GREATEST CHANCE OF SEEING HIGHER END SNOW EVENT.
NO MATTER HOW IT SHAKES OUT...THERE ARE INDICATIONS VERY CHILLY
AIRMASS...EVEN COLDER THAN ONE CURRENTLY AFFECTING THE REGION...WILL
SETTLE OVER UPR GREAT LAKES BY EARLY NEXT WEEK. BEYOND END OF
EXTENDED THERE ARE SIGNALS THAT RIDGE OVER EAST PACIFIC BREAKS DOWN
AND MORE MILD AIR RETURNS TO MUCH OF THE CONUS. PATTERN SHIFT THE
CFSV2 HAS BEEN SHOWING FOR A WHILE NOW. THUS...OVERALL IT DOES NOT
APPEAR THAT THE UPCOMING COLD WILL BE THAT LONG LASTING.
INTIALLY THE MAIN ISSUE WILL BE THE ONGOING WEST FLOW LAKE EFFECT
AND BLOWING SNOW WITH POOR VSBY OVER THE KEWEENAW. DECENT AGREEMENT
THAT SHORTWAVE DROPPING WNW-ESE OVER LK SUPERIOR AND UPR MICHIGAN
WEDNESDAY EVENING WITH LEADING SFC TROUGH AND ENHANCED CONVERGENCE
AND ADDITIONAL MOISTURE WILL RESULT IN A A BRIEF PERIOD OF MODERATE
TO HEAVY LES. WIND CORE MAX AT 950-925MB OVER 40 KTS WILL BE EASING
BY WEDNESDAY EVENING...BUT MIXED LAYER WINDS UP TO 40 KTS WILL STILL
RESULT IN STRONG/GUSTY WINDS OVER 30 MPH AND BLSN/POOR VSBY.
SOUNDINGS SHOW MARGINAL MOISTURE AND INSTABILITY FOR SIGNIFICANT LES
THOUGH AFTER THE TROUGH PASSAGE WITH INVERSIONS PEAKING AT 5-7 KFT
AGL WEDNESDAY EVENING AND LAKE INDUCED EQL NOT MUCH HIGHER THAN
THAT. MAJORITY OF THE MOIST LAYER IS WITHIN THE DGZ BUT STRONG WINDS
WILL LIKELY CUT DOWN SLR/S. POOR VSBY WILL BE THE BIGGER STORY
COMPARED TO SNOW AMOUNTS. AFTER COORDINATING WITH SHORT TERM
FORECASTER... DECIDED TO GO WITH LAKE EFFECT SNOW ADVISORY FOR SNOW
AND BLOWING SNOW WEDNESDAY AFTN THROUGH EARLY AFTERNOON ON NEW YEARS
DAY. WILL MENTION OCCASIONAL WHITEOUT CONDITIONS IN THE WSW
STATEMENT.
LAKE EFFECT AND BLOWING SNOW BECOME FACTOR LATE WEDNESDAY NIGHT INTO
THURSDAY FOR AREAS FAVORED BY WNW WINDS...ONTONAGON COUNTY OVER THE
WEST AND IN THE SNOW BELTS OF EASTERN HALF OF UPR MICHIGAN. LOOKING
AT ONLY A PURE LES SETUP AS SOUNDINGS SHOW SHARP DRYING ABOVE 8KFT.
TEMPS AT TOP OF INVERSION BLO -20C LEAD TO MARGINAL INSTABILITY GIVEN
WATER TEMPS 2-3C. MOST OF LAKE CONVECTIVE LAYER WILL BE IN THE DGZ
AND WINDS WILL BE DIMINISHING...SO FLUFF FACTOR WILL PLAY MORE OF A
ROLE. OVERALL...ADVY SNOW AMOUNTS SEEM POSSIBLE INTO NEW YEARS DAY
FOR THE WNW FLOW AREAS.
LAKE EFFECT LINGERS FOR WNW FLOW AREAS INTO FRIDAY...BUT WILL
CONTINUE TO DIMINISH AS HIGH PRESSURE RIDGE SLIDES ACROSS WESTERN
GREAT LAKES. COLD WILL SLOWLY EASE...THOUGH TEMPS WELL BLO ZERO
EXPECTED THURSDAY NIGHT OVER INTERIOR CNTRL UPR MICHIGAN. INCREASE
OF MID CLOUDS MAY RESULT IN LESS TEMP DROP OVER WEST CWA.
MAIN QUESTION THIS WEEKEND IS HOW MUCH PHASING OCCURS BTWN
APPROACHING NORTHERN STREAM SHORTWAVE TROUGH AND THE UPPER LOW
OPENING UP AS IT LIFTS INTO THE CNTRL PLAINS FM THE SOUTHWEST CONUS.
SINCE MAJORITY OF JET ENERGY REMAINS AHEAD OF THE SOUTHERN STREAM
TROUGH...WOULD EXPECT IT TO STAY FAIRLY PROGRESSIVE AND HAVE LESS
CHANCE OF PHASING WITH NORTHERN STREAM SYSTEM. EVEN SO...THE
NORTHERN STREAM SHORTWAVE ALONG WITH INCREASING NNE-NNW FLOW WITH
H85 TEMPS BLO -12C SATURDAY NIGHT INTO SUNDAY MAY LEAD TO SEVERAL
INCHES OF SNOW. BEST SHOT OF SYNOPTIC SNOW WOULD BE OVER THE SOUTH
AND EAST CWA WHILE THE GREATEST CHANCE FOR LAKE ENHANCEMENT WOULD BE
OVER THE WEST AND NORTH CENTRAL CWA. TIGHT PRESSURE GRADIENT RESULTS
IN GUSTY WINDS AND BLOWING SNOW AS WELL. MODEL TRENDS FOR THIS
SYSTEM ARE VARIABLE WITH EARLIER RUNS A FEW DAYS AGO SHOWING A
WRAPPED UP SYSTEM AND RECENT RUNS BACKING AWAY FM THAT. LATEST RUNS
SEEM TO BE TRYING TO COME BACK TO AT LEAST A FARTHER WEST TRACK TO
THE SOUTHERN STREAM SYSTEM IF NOT A MORE PHASED SYSTEM. SYSTEM BEARS
WATCHING AS IT COULD RESULT IN SOME HEADLINES.
BEHIND THE SYSTEM...LOOKS VERY COLD WITH H85 TEMPS DOWN TO -28C BY
NEXT MONDAY. INCREASED POPS FOR LAKE EFFECT IN WNW-W FLOW AREAS.
MAJORITY OF LAKE CONVECTIVE LAYER IS AT TEMPS BLO -20C...SO SLR/S
WILL BE LOW AND MAIN PROBLEM COULD BE POOR VSBY. COULD ALSO HAVE
WIND CHILL ISSUES FOR THE FIRST DAY BACK TO SCHOOL AFTER WINTER
VACATION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1156 PM EST TUE DEC 30 2014
LAKE EFFECT SNOW WILL FAVOR PERSISTENT MVFR CIGS AND IFR/LIFR VSBY
AT CMX THROUGH THE PERIOD. GUSTY WINDS INTO WED MORNING WILL ALSO
REDUCE VSBY WITH BLSN. AT SAW AND IWD...VFR CONDITIONS WILL CONTINUE
THROUGH THE PERIOD. WILL GET GUSTY AT ALL SITES LATE TONIGHT THROUGH
WED.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 358 AM EST WED DEC 31 2014
LAKE SUPERIOR WILL BE STUCK BETWEEN VERY STRONG HIGH PRESSURE ACROSS
THE S PLAINS AND A DEEP HUDSON BAY LOW TODAY. GALES OF 35-45KTS WILL
CONTINUE BEFORE SLOWLY DIMINISHING TO 35KTS LATE TONIGHT INTO
THURSDAY MORNING OUT OF THE W-NW. GIVEN PLENTY OF COLD AIR...AND
STRONG WINDS...HEAVY FREEZING SPRAY WILL ALSO BE A CONCERN INTO
THURSDAY.
LOOK FOR THE TROUGH OVER LAKE SUPERIOR TO DEEPEN TONIGHT THROUGH
THURSDAY. THE HUDSON BAY LOW WILL SHIFT AND WEAKEN ACROSS N QUEBEC
THURSDAY NIGHT...ALLOWING THE TROUGH ACROSS LAKE SUPERIOR TO WEAKEN
AS WELL. HIGH PRESSURE SINKING ACROSS MANITOBA AND MINNESOTA
THURSDAY NIGHT WILL BUILD RIDGE ACROSS LAKE SUPERIOR ON FRIDAY AS IT
PROGRESSES ACROSS THE REMAINDER OF THE GREAT LAKES. A WEAK TROUGH
WILL LIKELY LINGER ACROSS MAINLY E LAKE SUPERIOR DURING THIS TIME.
EXPECT A LOW NEAR MONTANA ON FRIDAY TO TRACK ACROSS THE N AND
CENTRAL PLAINS SATURDAY MORNING...AND THE MID MISSISSIPPI VALLEY
SATURDAY AFTERNOON...BEFORE DEEPENING NORTHEASTWARD ACROSS THE LOWER
GREAT LAKES AND QUEBEC LATE SATURDAY NIGHT INTO SUNDAY. THIS WILL
BRING A TROUGH OF SATURDAY NIGHT INTO SUNDAY ACROSS LAKE
SUPERIOR...ALONG WITH THE RETURN OF N-NW GALES OF 35-40KTS. HEAVY
FREEZING SPRAY WILL ALSO MAKE A RETURN ACROSS MUCH OF LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND CHILL ADVISORY UNTIL 10 AM EST /9 AM CST/ THIS MORNING FOR
MIZ002-004-005-009>012-084.
LAKE EFFECT SNOW ADVISORY FROM 1 PM THIS AFTERNOON TO 1 PM EST
THURSDAY FOR MIZ001-003.
LAKESHORE FLOOD ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR MIZ001-
003.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST /NOON CST/ THURSDAY
FOR LSZ240>251-263>267.
GALE WARNING UNTIL 1 PM EST THURSDAY FOR LSZ244-245-264>267.
GALE WARNING FROM 7 PM THIS EVENING TO 1 PM EST THURSDAY FOR
LSZ249>251.
GALE WARNING FROM 10 AM THIS MORNING TO 1 PM EST THURSDAY FOR
LSZ246>248.
GALE WARNING UNTIL 7 AM EST /6 AM CST/ THURSDAY FOR LSZ162-
241>243-263.
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST /6 AM CST/ THURSDAY
FOR LSZ162.
LAKE MICHIGAN...
HEAVY FREEZING SPRAY WARNING FROM 10 AM THIS MORNING TO 1 PM EST
THURSDAY FOR LMZ221-248-250.
GALE WARNING FROM 10 AM THIS MORNING TO 1 AM EST THURSDAY FOR
LMZ221-250.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...07
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1156 PM EST TUE DEC 30 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 427 PM EST TUE DEC 30 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A PROMINENT MID/UPPER LEVEL
RIDGE FROM THE ERN PACIFIC INTO BC AND A TROUGH OVER NE CANADA
RESULTING IN NNW FLOW TOWARD NRN ONTARIO AND THE NRN LAKES. A
SHORTWAVE TROUGH AXIS EXTENDED FROM JAMES BAY INTO SE NORTH DAKOTA.
WITH ONLY WEAK FORCING AND LITTLE MOISTURE AVAILABLE...NO PCPN WAS
ASSOCIATED WITH THIS FEATURE. FURTHER UPSTREAM...A STRONGER SHRTWV
WAS MOVING THROUGH NRN SASK/MANITOBA. AT THE SFC...W TO WNW FLOW
PREVAILED ACROSS UPPER MI AND LAKE SUPERIOR AS 1048 MB HIGH PRES
CONTINUES TO SINK THROUGH THE NRN AND CNTRL PLAINS. EVEN WITH 850 MB
TEMPS NEAR -23C...SATELLITE/RADAR INDICATED ONLY LIGHT TO MODERATE
LES INTO NW UPPER MI AND EAST OF MUNISING AS INVERSION HEIGHTS
REMAINED NEAR 4K FT WITH VERY DRY AIR UPSTREAM.
TONIGHT...EXPECT WINDS TO GRADUALLY BACK TO SW AHEAD OF THE
SASK/MANITOBA SHRTWV WHICH WILL PUSH THE LES MOSTLY OFFSHORE.
HOWEVER...ADDITIONAL SNOWFALL AMOUNTS OF 1 TO 3 INCHES NW(KEWEENAW
AND 2 TO 4 INCHES NE (NE OF P53) ARE POSSIBLE. TEMPS FALLING OFF
INTO THE -7F TO -12F RANGE AND WINDS NEAR 10 MPH WILL DROP WIND
CHILLS INTO THE -20 TO -33 RANGE OVER THE INTERIOR WRN HALF WHERE
WIND CHILL ADVISORIES WILL REMAIN IN EFFECT.
WEDNESDAY...AS THE SHRTWV MOVES THROUGH THE NRN LAKES AND DRAGS A
WEAK TROUGH THE AREA...WINDS WILL VEER AGAIN FROM SW TO W BY
AFTERNOON. THIS WILL BRING THE LES INTO THE NRN KEWEENAW BY MIDDAY
AND INTO MUCH OF THE REST OF THE PENINSULA BY MID TO LATE AFTERNOON.
THE COMBINATION OF THE LES AND WIND GUSTS OVER 40 MPH WILL LEAD TO
VERY POOR VSBY WHICH WILL LINGER INTO THE EVENING...PROMPTING THE
ISSUANCE OF AN LES ADVY. ALTHOUGH THERE WILL BE A PERIOD OF DEEPER
MOISTURE THAT SHOULD INTENSIFY LES...THE SHIFTING WIND DIRECTIONS
SHOULD LIMIT OVERALL AMOUNTS TO THE 1 TO 3 INCH RANGE BY EVENING.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 427 PM EST TUE DEC 30 2014
UPPER AIR PATTERN STARTS OUT WITH TROUGHING ANCHORED OVER HUDSON BAY
AND ANOTHER MORE COMPACT TROUGH OVER DESERT SOUTHWEST OF CONUS. ONLY
RIDGING OF NOTE IS OVER THE EASTERN PACIFIC OCEAN INTO FAR WESTERN
CANADA. ATTENTION THIS WEEKEND WILL BE ON THE SOUTHWEST CONUS TROUGH.
MODELS CONTINUE TO FAVOR IDEA THAT AS STRONG JET ENERGY ADVANCES
AHEAD OF TROUGH...IT WILL EMERGE OVER THE SOUTHERN PLAINS ON
SATURDAY AND LIFT OVER THE GREAT LAKES ON SUNDAY. MEANWHILE...ANOTHER
SHORTWAVE WITHIN THE BASE OF LARGER TROUGHING OVER EASTERN CANADA
WILL WORK OVER THE UPPER GREAT LAKES. ONE OR BOTH OF THESE FEATURES
MAY BRING WIDESPREAD SNOW TO UPR MICHIGAN FRIDAY NIGHT THROUGH
SATURDAY NIGHT. THERE IS POTENTIAL THAT THE TWO FEATURES COULD
PHASE...THOUGH THAT IS NOT CERTAIN...AND THAT WOULD RESULT IN
GREATEST CHANCE OF SEEING HIGHER END SNOW EVENT.
NO MATTER HOW IT SHAKES OUT...THERE ARE INDICATIONS VERY CHILLY
AIRMASS...EVEN COLDER THAN ONE CURRENTLY AFFECTING THE REGION...WILL
SETTLE OVER UPR GREAT LAKES BY EARLY NEXT WEEK. BEYOND END OF
EXTENDED THERE ARE SIGNALS THAT RIDGE OVER EAST PACIFIC BREAKS DOWN
AND MORE MILD AIR RETURNS TO MUCH OF THE CONUS. PATTERN SHIFT THE
CFSV2 HAS BEEN SHOWING FOR A WHILE NOW. THUS...OVERALL IT DOES NOT
APPEAR THAT THE UPCOMING COLD WILL BE THAT LONG LASTING.
INTIALLY THE MAIN ISSUE WILL BE THE ONGOING WEST FLOW LAKE EFFECT
AND BLOWING SNOW WITH POOR VSBY OVER THE KEWEENAW. DECENT AGREEMENT
THAT SHORTWAVE DROPPING WNW-ESE OVER LK SUPERIOR AND UPR MICHIGAN
WEDNESDAY EVENING WITH LEADING SFC TROUGH AND ENHANCED CONVERGENCE
AND ADDITIONAL MOISTURE WILL RESULT IN A A BRIEF PERIOD OF MODERATE
TO HEAVY LES. WIND CORE MAX AT 950-925MB OVER 40 KTS WILL BE EASING
BY WEDNESDAY EVENING...BUT MIXED LAYER WINDS UP TO 40 KTS WILL STILL
RESULT IN STRONG/GUSTY WINDS OVER 30 MPH AND BLSN/POOR VSBY.
SOUNDINGS SHOW MARGINAL MOISTURE AND INSTABILITY FOR SIGNIFICANT LES
THOUGH AFTER THE TROUGH PASSAGE WITH INVERSIONS PEAKING AT 5-7 KFT
AGL WEDNESDAY EVENING AND LAKE INDUCED EQL NOT MUCH HIGHER THAN
THAT. MAJORITY OF THE MOIST LAYER IS WITHIN THE DGZ BUT STRONG WINDS
WILL LIKELY CUT DOWN SLR/S. POOR VSBY WILL BE THE BIGGER STORY
COMPARED TO SNOW AMOUNTS. AFTER COORDINATING WITH SHORT TERM
FORECASTER... DECIDED TO GO WITH LAKE EFFECT SNOW ADVISORY FOR SNOW
AND BLOWING SNOW WEDNESDAY AFTN THROUGH EARLY AFTERNOON ON NEW YEARS
DAY. WILL MENTION OCCASIONAL WHITEOUT CONDITIONS IN THE WSW
STATEMENT.
LAKE EFFECT AND BLOWING SNOW BECOME FACTOR LATE WEDNESDAY NIGHT INTO
THURSDAY FOR AREAS FAVORED BY WNW WINDS...ONTONAGON COUNTY OVER THE
WEST AND IN THE SNOW BELTS OF EASTERN HALF OF UPR MICHIGAN. LOOKING
AT ONLY A PURE LES SETUP AS SOUNDINGS SHOW SHARP DRYING ABOVE 8KFT.
TEMPS AT TOP OF INVERSION BLO -20C LEAD TO MARGINAL INSTABILITY GIVEN
WATER TEMPS 2-3C. MOST OF LAKE CONVECTIVE LAYER WILL BE IN THE DGZ
AND WINDS WILL BE DIMINISHING...SO FLUFF FACTOR WILL PLAY MORE OF A
ROLE. OVERALL...ADVY SNOW AMOUNTS SEEM POSSIBLE INTO NEW YEARS DAY
FOR THE WNW FLOW AREAS.
LAKE EFFECT LINGERS FOR WNW FLOW AREAS INTO FRIDAY...BUT WILL
CONTINUE TO DIMINISH AS HIGH PRESSURE RIDGE SLIDES ACROSS WESTERN
GREAT LAKES. COLD WILL SLOWLY EASE...THOUGH TEMPS WELL BLO ZERO
EXPECTED THURSDAY NIGHT OVER INTERIOR CNTRL UPR MICHIGAN. INCREASE
OF MID CLOUDS MAY RESULT IN LESS TEMP DROP OVER WEST CWA.
MAIN QUESTION THIS WEEKEND IS HOW MUCH PHASING OCCURS BTWN
APPROACHING NORTHERN STREAM SHORTWAVE TROUGH AND THE UPPER LOW
OPENING UP AS IT LIFTS INTO THE CNTRL PLAINS FM THE SOUTHWEST CONUS.
SINCE MAJORITY OF JET ENERGY REMAINS AHEAD OF THE SOUTHERN STREAM
TROUGH...WOULD EXPECT IT TO STAY FAIRLY PROGRESSIVE AND HAVE LESS
CHANCE OF PHASING WITH NORTHERN STREAM SYSTEM. EVEN SO...THE
NORTHERN STREAM SHORTWAVE ALONG WITH INCREASING NNE-NNW FLOW WITH
H85 TEMPS BLO -12C SATURDAY NIGHT INTO SUNDAY MAY LEAD TO SEVERAL
INCHES OF SNOW. BEST SHOT OF SYNOPTIC SNOW WOULD BE OVER THE SOUTH
AND EAST CWA WHILE THE GREATEST CHANCE FOR LAKE ENHANCEMENT WOULD BE
OVER THE WEST AND NORTH CENTRAL CWA. TIGHT PRESSURE GRADIENT RESULTS
IN GUSTY WINDS AND BLOWING SNOW AS WELL. MODEL TRENDS FOR THIS
SYSTEM ARE VARIABLE WITH EARLIER RUNS A FEW DAYS AGO SHOWING A
WRAPPED UP SYSTEM AND RECENT RUNS BACKING AWAY FM THAT. LATEST RUNS
SEEM TO BE TRYING TO COME BACK TO AT LEAST A FARTHER WEST TRACK TO
THE SOUTHERN STREAM SYSTEM IF NOT A MORE PHASED SYSTEM. SYSTEM BEARS
WATCHING AS IT COULD RESULT IN SOME HEADLINES.
BEHIND THE SYSTEM...LOOKS VERY COLD WITH H85 TEMPS DOWN TO -28C BY
NEXT MONDAY. INCREASED POPS FOR LAKE EFFECT IN WNW-W FLOW AREAS.
MAJORITY OF LAKE CONVECTIVE LAYER IS AT TEMPS BLO -20C...SO SLR/S
WILL BE LOW AND MAIN PROBLEM COULD BE POOR VSBY. COULD ALSO HAVE
WIND CHILL ISSUES FOR THE FIRST DAY BACK TO SCHOOL AFTER WINTER
VACATION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1156 PM EST TUE DEC 30 2014
LAKE EFFECT SNOW WILL FAVOR PERSISTENT MVFR CIGS AND IFR/LIFR VSBY
AT CMX THROUGH THE PERIOD. GUSTY WINDS INTO WED MORNING WILL ALSO
REDUCE VSBY WITH BLSN. AT SAW AND IWD...VFR CONDITIONS WILL CONTINUE
THROUGH THE PERIOD. WILL GET GUSTY AT ALL SITES LATE TONIGHT THROUGH
WED.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 427 PM EST TUE DEC 30 2014
WEST TO SOUTHWEST GALES 40-45 KTS ARE EXPECTED OVER MOST OF LK
SUPERIOR BEGINNING LATER TONIGHT WILL SHIFT TO WEST-NORTHWEST GALES
TO 35 KTS LATE WEDNESDAY NIGHT INTO THURSDAY MORNING. IN ADDITION TO
THE GALES... HEAVY FREEZING SPRAY WILL AFFECT MOST OF THE LAKE INTO
THURSDAY. WINDS DIMINISH TO LESS THAN 25 KTS BY FRIDAY...BUT THE
LULL WILL BE BRIEF AS NORTHERLY WINDS INCREASE TO GALES TO 40 KTS
SATURDAY NIGHT INTO SUNDAY. MORE HEAVY FREEZING SPRAY WILL OCCUR AT
THIS TIME AS WELL.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND CHILL ADVISORY UNTIL 10 AM EST /9 AM CST/ WEDNESDAY FOR
MIZ002-004-005-009>012-084.
LAKE EFFECT SNOW ADVISORY FROM 1 PM WEDNESDAY TO 1 PM EST
THURSDAY FOR MIZ001-003.
LAKESHORE FLOOD ADVISORY FROM 6 AM WEDNESDAY TO MIDNIGHT EST
WEDNESDAY NIGHT FOR MIZ001-003.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST /NOON CST/ THURSDAY
FOR LSZ240>245-248>251-263>267.
GALE WARNING UNTIL 1 PM EST THURSDAY FOR LSZ244-245-264>267.
GALE WARNING FROM 7 PM WEDNESDAY TO 1 PM EST THURSDAY FOR
LSZ249>251.
GALE WARNING FROM 10 AM WEDNESDAY TO 1 PM EST THURSDAY FOR
LSZ246>248.
HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST THURSDAY FOR LSZ246-
247.
GALE WARNING UNTIL 7 AM EST /6 AM CST/ THURSDAY FOR LSZ162-
241>243-263.
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST /6 AM CST/ THURSDAY
FOR LSZ162.
LAKE MICHIGAN...
HEAVY FREEZING SPRAY WARNING FROM 10 AM WEDNESDAY TO 1 PM EST
THURSDAY FOR LMZ221-248-250.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...07
MARINE...JLA
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
830 PM CST THU JAN 1 2015
...WET WEATHER PATTERN INTO FIRST HALF OF WEEKEND...WITH INCREASING
RISK OF STRONG TO SEVERE STORMS AND HEAVY DOWNPOURS ON SATURDAY...
.UPDATE...ISENTROPIC LIFT ON SURFACES BETWEEN 300K AND 310K THIS
AFTERNOON INTO THIS EVENING HAS BEEN THE DRIVING MECHANISM BEHIND
STEADY RAIN STREAMING ACROSS THE NORTHERN TWO-THIRDS OF THE REGION.
CHILLY HIGH PRESSURE AT THE SURFACE UNDERNEATH BUILDING MOIST
SOUTHERLY FLOW WILL SLOWLY TRANSITION TO THE EAST INTO EARLY
TOMORROW....WHICH WILL HAVE THE TANGIBLE EFFECT OF WEAKENING THE
ISENTROPIC LIFT ASPECT BY DAYBREAK FRIDAY. BUT THAT CERTAINLY DOES
NOT MEAN RAIN WILL CEASE BY FRIDAY MORNING BECAUSE INCREASING
MOISTURE ADVECTION AND LIFT ASSOCIATED WITH UPPER LEVEL JET DYNAMICS
WILL KEEP AT LEAST SCATTERED SHOWERY-TYPE PRECIP GOING WELL INTO
TOMORROW MORNING. IT IS NOT UNTIL TOMORROW AFTERNOON THAT THERE
MIGHT NOT BE A DEFINITE LULL IN RAINFALL AS MULTIPLE ATMOSPHERIC
LIFTING MECHANISMS RETREAT BACK TO THE WEST TEMPORARILY...MARSHALING
FORCES FOR A UNIFIED RUN AT THE LOWER MS VALLEY LATER FRIDAY NIGHT
AND SATURDAY.
BUT...FOR TONIGHT...INHERITED FORECAST WAS IN PRETTY GOOD SHAPE AND
ADJUSTMENTS WERE RATHER MINOR. FOLLOWED HRRR HOURLY TEMPS VERY
CLOSELY AS THIS MODEL SEEMS QUITE ACCURATE IN ITS DEPICTION OF A
SLOW RISE THROUGH THE NIGHT AND INTO TOMORROW MORNING. POPS WERE
KEPT AT CATEGORICAL FOR THE NORTHERN TWO-THIRDS OF ZONES BUT WERE
LOWERED A BIT IN SOUTHERN ZONES SINCE THE BAROCLINIC NATURE OF RAIN
PRODUCTION TONIGHT DOES NOT FAVOR A GREAT DEAL OF RAIN SOUTH OF THE
ELEVATED BAROCLINIC ZONE. ALSO LIMITED THUNDER POTENTIAL FOR THIS
EVENING TO WEST-CENTRAL ZONES WHERE AN ELEVATED THUNDERSTORM SOURCE
NEAR THE SABINE RIVER COULD MANIFEST IN A FEW BOOMS LARGELY WEST OF
THE MS RIVER BEFORE MIDNIGHT. AFTER MIDNIGHT THE POTENTIAL FOR A
STRAY RUMBLE OF THUNDER WILL EXPAND AS THE POOL OF ELEVATED
INSTABILITY MARCHES FURTHER NORTH. NO SEVERE WEATHER IS EXPECTED
WITH ANY THUNDERSTORMS TONIGHT AND...WHILE A FEW HEAVIER DOWNPOURS
ARE POSSIBLE AT TIMES IN NORTHERN ZONES...NO FLOODING ISSUES ARE
ANTICIPATED UNTIL LATER ON TOMORROW AT THE EARLIEST. /BB/
&&
.PREV DISCUSSION... /ISSUED 339 PM CST THU JAN 1 2015/
SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT...RAIN HAS BECOME
WIDESPREAD OVER MOST OF OUR AREA THIS AFTERNOON WITH THE EXCEPTION
OF THE HIGHWAY 98 CORRIDOR. POCKETS OF MODERATE TO HEAVY RAIN ARE
OCCURRING OVER THE NORTHWEST HALF OF THE AREA. TRENDS AND MODELS
INDICATE THIS RAIN WILL CONTINUE FOR AT LEAST SEVERAL MORE HOURS AS
ISENTROPIC ASCENT CONTINUES AHEAD OF LEAD S/WV SHOWN IN WATER VAPOR
OVER EASTERN TX ATTM. MODELS INDICATE A LULL IN THE PRECIPITATION
LATER TONIGHT INTO FRIDAY AS LOW LEVEL VEERS IN WAKE OF INITIAL
WAVE. HAVE WENT ALONG WITH THIS TREND BY LOWERING POPS A BIT DURING
THIS TIME FROM CATEGORICAL VALUES OF EARLIER TONIGHT. WHILE POPS
WILL BE LOWER...STILL EXPECT SOME PRECIPITATION TO CONTINUE AS
ISENTROPIC ASCENT OF MOIST AND SOMEWHAT UNSTABLE GULF AIR CONTINUES
ATOP RESIDUAL COOL DOME NEAR SURFACE. HIGH RESOLUTION MODELS SHOW
MORE SHOWERY NATURE TO PRECIPITATION AND HAVE DEPICTED WEATHER GRIDS
ACCORDINGLY.
FURTHER UPTICK IN PRECIPITATION COVERAGE EXPECTED AGAIN LATER FRIDAY
NIGHT INTO EARLY SATURDAY. MODELS DEPICT THIS IN TWO FOCI...ONE OVER
OUR FAR WESTERN AREAS AS MAIN UPPER TROUGH BEGINS TO APPROACH...AND
ANOTHER FARTHER EAST IN AREA OF INCREASING LOW LEVEL WARM AIR
ADVECTION/ISENTROPIC ASCENT OVER EASTERN HALF OF MS. CONSENSUS OF
MODEL POPS CAPTURE THIS SCENARIO PRETTY WELL AND HAVE ACCEPTED.
MAIN TIME PERIOD FOR HAZARDOUS WEATHER POTENTIAL LOOKS TO BE
SAT INTO SAT EVE. MODELS IN AGREEMENT THAT SW CONUS MID/UPPER LEVEL
LOW WILL EJECT THROUGH THE SOUTHERN PLAINS...INCITING DEVELOPING
SURFACE CYCLONE TO OUR NW. UNUSUALLY WARM/MOIST AIRMASS WHICH WILL
HAVE BEEN BUILDING OFFSHORE NEXT 24-36 HOURS WILL SURGE NORTH AS
PRESSURES FALL ACROSS REGION. GFS/EURO AGREE ON 65-70F SURFACE
DEWPOINTS OVERSPREADING MOST OF OUR AREA BY MIDDAY SAT. LAPSE RATES
WILL ACTUALLY BE RELATIVELY ROBUST FOR MID WINTER AS WELL WITH
VERTICAL TOTALS IN THE 27-28C RANGE. THIS WILL SUPPORT MLCAPE VALUES
OF 750 TO 1250 J/KG...POTENTIALLY A BIT HIGHER IN ANY AREAS WHICH
GET A LITTLE SUN. LOW AND DEEP LAYER SHEAR WILL BE VERY FAVORABLE
FOR SEVERE WEATHER AS LOW/MID LEVEL JETSTREAKS OVERSPREAD AREA WITH
THE EJECTING TROUGH. ALL THIS SPELLS AN INCREASING RISK FOR SEVERE
STORMS SAT...INCLUDING THE POTENTIAL FOR SOME TORNADOES. MAIN UPPER
TROUGH IS EJECTING WELL TO OUR NW WHICH WILL LIMIT MID LEVEL HEIGHT
FALLS THE FARTHER SOUTH ONE GOES. HOWEVER...IT DOES APPEAR THERE
WILL BE AN OVERLAY OF DECENT HEIGHT FALLS AND FAVORABLE PARAMETER
SPACING OVER THE NW 2/3 OF OUR AREA...AND UPPER JET SUPPORT IS
FAVORABLE IN ENTRANCE REGION OF 150 KT 250 MB JET PULLING THROUGH
MID MS VALLEY. FOR NOW HAVE INCREASED THE AREA GENERALLY ALONG AND
JUST NW OF THE NATCHEZ TRACE TO AN ELEVATED RISK OF SEVERE...AND
EXPECT FURTHER REFINEMENTS WILL BE NEEDED THE CLOSER THE EVENT COMES.
WITH REGARD TO HEAVY RAINFALL POTENTIAL...AS MENTIONED ABOVE MODELS
SUGGEST VERY FAVORABLE UPPER JET SUPPORT FOR ROBUST CONVECTION ACROSS
AREA SAT INTO SAT NIGHT. RIGHT NOW APPEARS AS THOUGH THERE WILL BE
TWO FOCI FOR ORGANIZED HEAVY RAIN PRODUCING STORMS. FIRST WILL BE IN
THE WESTERN AREAS FRI NIGHT THROUGH EARLY SAT AFTERNOON AS UPPER
DIVERGENCE OVERSPREADS AREA JUST EAST OF AN AXIS OF STRONG MOISTURE
TRANSPORT. GFS SHOWS A WEAKNESS IN CORFIDI VECTORS HERE DURING THIS
TIME PERIOD IMPLYING INCREASED RISK OF TRAINING. OF PERHAPS MORE
CONCERN IS AREA OF SURGING SUBTROPICAL AIRMASS WITH 330+K 850 MB
THETA E AND PW VALUES APPROACHING 2 INCHES WHICH ECMWF/GFS SHOW
COMING UP INTO SOUTHERN MS BY SAT AFTERNOON. THIS SETS UP A STRONG
AXIS OF MOISTURE TRANSPORT FROM SC LA THROUGH NE MS WHICH HOLDS IN
PLACE FOR ABOUT 12 HOURS AS UPPER JET SUPPORT OVERSPREADS AREA. THIS
COULD RESULT IN TRAINING OF EFFICIENT RAIN PRODUCING STORMS FOR
SEVERAL HOURS SOMEWHERE ACROSS CENTRAL/ERN MS SAT AFTERNOON AND
EVENING. FOR NOW GIVEN RATHER MESOSCALE NATURE OF THIS POTENTIAL
SETUP WILL JUST LEAVE FLOODING POTENTIAL IN HWO AS LIMITED...BUT WILL
NEED TO MONITOR FOR GREATER RISK AND POSSIBLE FLASH FLOOD WATCH AS
THE EVENT APPROACHES. THERE WILL ALSO BE SOME RISK OF PONDING ISSUES
DUE TO PROLONGED NATURE OF WAVES OF MODERATE TO HEAVY RAIN WITH
EMBEDDED TSRA TONIGHT THROUGH FRIDAY NIGHT AND THIS WILL ALSO BE
MENTIONED IN HWO. GFS AND EURO NOW SHOWING 72 HOUR TOTALS OF 2-4
INCHES OVER MOST OF OUR AREA BY SUNDAY MORNING. /AEG/
LONG TERM...SUNDAY THROUGH THURSDAY...ONCE IMPACT WEATHER SYSTEM
MOVES EAST OF THE AREA BY EARLY SUNDAY...WEATHER FOCUS WILL SHIFT TO
THREAT OF BELOW TO MUCH BELOW NORMAL TEMPERATURES MUCH OF NEXT WEEK.
MODELS AGREE ON A COUPLE OF STRONG ARCTIC HIGHS BUILDING DOWN INTO
REGION...FIRST MON/TUE AND THE NEXT LATE WED INTO FRI. RIGHT NOW
MODELS SHOW COLDEST AIR COMING DOWN WITH SECOND HIGH...WITH PARALLEL
GFS AND EURO SHOWING POTENTIAL FOR SOME HARD FREEZE CONDITIONS OVER
THE HIGHWAY 82 CORRIDOR WITH LOWS DOWN INTO UPPER TEENS AND HIGHS
NEAR FREEZING ON THU. HOWEVER...A LITTLE HESITANT TO BITE OFF ON THIS
SOLUTION JUST YET GIVEN THAT 500 MB PATTERN IS SOMEWHAT PROGRESSIVE
AND TELECONNECTION INDICES ARE NOT VERY SUPPORTIVE OF A BIG ARCTIC
DUMP. FOR NOW HAVE JUST TRENDED A TAD BELOW MODEL CONSENSUS TEMPS
WHICH TOWARD DAYS 6 AND 7. OVERALL SHOULD BE A DRY PERIOD WITH COOL
TO COLD TEMPS. SEVERAL DAYS OF SUBFREEZING MINS ARE LIKELY...AND
COULD BE SOME MORNINGS WITH WIND CHILL READINGS DOWN INTO AT LEAST
THE TEENS. /AEG/
&&
.AVIATION...IFR CONDITIONS ARE PUSHING EAST INTO THE ARKLAMISS DELTA
THIS EVENING AND ARE EXPECTED TO OVERSPREAD MOST OF THE
REGION...ASIDE FROM PERHAPS MEI/PIB/HBG SITES...BUT DAYBREAK FRIDAY.
RAIN WILL ACCOMPANY DETERIORATED FLIGHT CATS THROUGH THE
NIGHT...ESPECIALLY ALONG AND NORTH OF THE I-20 CORRIDOR. FURTHER
SOUTH ANTICIPATED AT LEAST MVFR FLIGHT CATS AND A FEW SHOWERS. WINDS
TONIGHT WILL BE FROM THE NORTHEAST...BUT WILL BE VEERING TO EAST AND
SOUTHEAST BY TOMORROW. EXPECT FRIDAY TO BE A POOR AVIATION WEATHER
DAY WITH WIDESPREAD RA/TSRA EVENTUALLY PRODUCING IFR CONDITIONS OVER
THE ENTIRE AREA. LOOKING AHEAD TO FRIDAY NIGHT...WITH STRONG WARM
ADVECTION...FOG AND LIFR CONDITIONS MAY BE AN INCREASING CONCERN.
/EC/BB/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 44 54 55 72 / 89 79 57 91
MERIDIAN 44 52 54 73 / 82 87 65 92
VICKSBURG 41 53 54 71 / 97 76 60 92
HATTIESBURG 49 59 60 74 / 50 72 52 90
NATCHEZ 42 59 60 71 / 75 65 52 92
GREENVILLE 39 47 47 68 / 100 83 74 92
GREENWOOD 41 48 50 69 / 100 82 63 92
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
BB/AEG/EC
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
538 PM CST Thu Jan 1 2015
.SHORT TERM: (Tonight and Friday)
Issued at 338 PM CST Thu Jan 1 2015
The area is sandwiched between high pressure to the south and a trof
of low pressure up across the Upper Midwest. Southwest flow is the
result and temperatures have rebounded into the mid and upper 30s
across the entire area. With abundant cloud cover and weak
southwest flow continuing tonight, expect that lows tonight will be
several degrees warmer tonight than they were last night. Most
areas should get back down below freezing again, but think temps
should stay mostly in the upper 20s to low 30s across the majority
of the area (with the exception of northern MO and west central IL
where clouds should be thinner allowing for more radiational
cooling). NAM, GFS, and RAP develop some weak moisture convergence
on the 850mb baroclinic zone Friday morning just south of the STL
Metro area. While the GFS says dry, the NAM and to a lesser extent
the RAP do print out a little very light QPF. 4km NCEP and NSSL WRF
models also show very light QPF Friday morning, and light simulated
radar returns as well. Therefore, feel there`s enough signal to
bump up PoPs slightly for Friday morning along and southeast of
I-44/US-50. P-types will likely start out as a little rain/sleet
mix and where temps are below freezing there could be a bit of
glaze, but amounts look very light. Precip should turn quickly to
light rain or just sprinkles with a couple of hours of sunrise, and
highs look to be in the mid to upper 30s across the area on Friday.
Carney
.LONG TERM: (Friday Night through Next Thursday)
Issued at 421 PM CST Thu Jan 1 2015
Models are coming into better consensus with the storm system for
Friday night and Saturday. GFS and NAM continue to warm up bit by
bit. Most recent partial thickness forecasts show all critical
thickness lines for rain/snow well up into northern
Missouri/southern Iowa by the time the precipitation starts on
Friday night. Forecast soundings also have little or no cold layer
in the low levels indicating that sleet is becoming less and less
likely. So have more or less confined any chances of sleet to
northern zones Friday evening, changing over to all rain and
freezing rain where surface temperatures dictate. Think any
accumulations of freezing rain will be minor due to warm ground
temperatures and diabatic warming due to latent heat release.
Temperatures should warm above freezing after sunrise on Saturday
morning at any rate which should stop any ice accumulation. Think
the greatest amount of accumulation will be over northern MO and
west central IL and amounts should be between a trace and 0.05 inch.
Dry slot should wrap around into the storm on Saturday afternoon
which will likely make the rain slack off and even end across
southern portions of the area. Cold front moves through Saturday
evening with the tail end of the def-zone clipping our area.
Guidance seems to want to keep the majority of the QPF out of our
area over northwest Missouri and southern Iowa. However, it looks
like our northwest counties could get clipped with an inch or two of
snow before all the shouting is over.
Remainder of the forecast looks cold and dry as a longwave trof
deepens over the eastern CONUS. This will allow a couple of Arctic
air intrusions into the lower 48...one on Sunday and Monday behind
the weekend storm, and another midweek. This should keep
temperatures well below normal through the end of the forecast
period.
Carney
&&
.AVIATION: (For the 00z TAFs through 00z Friday Evening)
Issued at 528 PM CST Thu Jan 1 2015
Present indications are that VFR flight conditions should prevail
tonight although will have to keep an eye on a few patches of MVFR
cigs floating around southern MO. We should see MVFR cigs begin to
spread northeast into KCOU and the St. Louis terminals around
daybreak and gradually lower during the day. There might also be
some patchy light rain in the St. Louis area between around 12-15z,
but confidence is no greater than a PROB group - surface temps
should be just above freezing.
Specifics for KSTL:
Present indications are that VFR flight conditions should prevail
tonight although will have to keep an eye on a few patches of MVFR
cigs floating around southern MO. We should see MVFR cigs begin to
spread northeast into the St. Louis terminals around daybreak and
gradually lower during the day. There might also be some patchy
light rain between around 12-15z, but confidence is no greater
than a PROB group - surface temps should be just above freezing.
Glass
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1004 PM EST THU JAN 1 2015
.SYNOPSIS...
ACCUMULATING LAKE EFFECT SNOW WILL OCCUR TO THE SOUTHEAST OF LAKE
ONTARIO THROUGH FRIDAY NIGHT. A MORE WIDESPREAD STORM SYSTEM IS
EXPECTED TO BRING A MIX OF SNOW...SLEET AND FREEZING RAIN INTO THE
AREA BY LATE SATURDAY AFTERNOON. THE WINTRY MIX WILL THEN CHANGE
TO RAIN DURING THE NIGHT...FOLLOWED BY WARMER TEMPERATURES AND
SHOWERS ON SUNDAY.
&&
.NEAR TERM /THROUGH FRIDAY NIGHT/...
10 PM UPDATE...
SOUTHERN PERIPHERY OF LAKE ONTARIO SNOW BAND IS JUST NOW TOUCHING
THE FAR NORTHERN BORDER OF ONEIDA COUNTY. BASED ON WINDS OFF THE
LAKE AND LATEST MESO MODEL OUTPUT, BELIEVE THE BAND WILL DROP INTO
OUR FA IN THE NEXT 2 TO 3 HOURS. SNOWFALL INTENSITIES COULD REACH
1 TO 2 INCHES PER HOUR BETWEEN 6Z AND 12Z.
THE SYR BUFKIT PROFILE OFF THE 18Z NAM SUGGESTS THE BAND WILL DROP
SOUTH TO I-90 LATE TOMORROW MORNING OR EARLY AFTERNOON. WILL NEED
TO WATCH IF THE BAND CAN MAKE IT DOWN INTO THE CITY. IT WILL BE A
VERY CLOSE CALL REGARDLESS.
RAISED MINS FOR MOST LOCALES OVERNIGHT. SOUTHWESTERLY FLOW THIS
EVENING HAS HELD TEMPS NEAR 30 DEGREES IN MANY SPOTS. USED A
COMBINATION OF LAMP AND RAP HOURLY GUIDANCE FOR OVERNIGHT TEMPS.
3 PM UPDATE...
LOWER CLDS EXPECTED ALONG NRN ZONES AS MOISTURE CONTS TO STREAM
OFF OF UPSTREAM LKS IN SW FLOW. MAJORITY OF CWA SEEING FILTERED
SUNSHINE THRU HIGH CIRRUS. SFC LOW LOCATED NR HUDSON BAY AND CDFNT
EXTNDG BACK TO THE SW THRU LK SUPERIOR WL SHIFT SOUTH TONIGHT.
ADDED LIFT ALONG FRONT COMBINED WITH LK MOISTURE WL SET THE STAGE
FOR SIGNIFICANT LK SNOWS FOR LATE TONIGHT AND FRIDAY.
SNOWS WL BEGIN TO DROP INTO EXTRM NRN ONEIDA CNTY ARND MIDNIGHT
TONIGHT WITH DEEP INVERSION BCMG ESTABLISHED DRG THE MID-MRNG HRS.
INVERSION LOOKS TO BE ABOUT 7KFT DEEP WITH WELL-ALIGNED FLOW AND
QUITE A BIT OF INSTABILITY. AS THE CDFNT SHIFTS SOUTH AFT DAYBREAK
WINDS WL ALIGN FM A 280-290 FLOW AND RESULT IN SINGLE BAND OF SNOW.
LOOKS AS THO GEORGIAN BAY CONNECTION WL BE ESTABLISHED DRG THE LATE
MRNG/AFTN HRS. BAND LOOKS TO BE FAIRLY STEADY-STATE BTWN 15Z-21Z THO
IT WL BE WOBBLING A BIT. THUS EXPECT MAX SNOWFALL RATES OF 1-2
INCHES PER HR DRG THE LATE MRNG HRS AND POSSIBLY INTO THE AFTN.
AS DIURNAL HTG BEGINS TO WORK IT`S MAGIC EXPECT THAT SINGLE BAND WL
GO MORE CELLULAR DRG THE AFTN AND INTENSITY WL GRADUALLY BEGIN TO
LESSEN. STORM TOTAL SNOW ACCUMS FM 03Z TONIGHT TO 00Z SAT WL RANGE
FM 5-8 INCHES NORTH OF THE NY THRUWAY. EXCEPTION WL BE EXTRM NW
ONEIDA CNTY WHERE UP TO ONE FOOT OF SNOW IS EXPECTED TO FALL. THUS
HV GONE WITH LES WARNING FOR NRN ONEIDA AND LES ADVISORY FOR
ONONDAGA, MADISON AND SRN ONEIDA CNTYS FM 03Z TONIGHT TO 00Z SAT.
SNOWS WL SLIDE NORTH ON FRI NGT AND CONTRACT BACK TWD THE SHORE LINE
WITH JUST SCTD SNOW SHOWERS AS WINDS BACK ARND TO THE SW. 1035MB SFC
HIGH WL SETTLE ACRS SRN QUEBEC FRI NGT WITH RIDGE AXIS EXTNDG SWRD
INTO CWA ASSURING A QUIET NIGHT WHILE WE WAIT FOR THE NEXT SYSTEM.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
GLOBAL AND REGIONAL COMPUTER MODELS FROM AROUND THE WORLD REMAIN
CONSISTENT WITH A LOW PRESSURE AREA LIFTING OUT OF THE SOUTHERN
PLAINS EARLY THIS WEEKEND...AND TRACKING THROUGH THE GREAT LAKES
AND EASTERN CANADIAN PROVINCES ON SUNDAY. THE OVERALL PATTERN
RECOGNITION OF THIS SYSTEM SUGGESTS A RAPIDLY TRANSITIONING WINTRY
MIX EVOLVING OVER CNY AND NEPA FROM SATURDAY AFTERNOON TO EARLY
SUNDAY MORNING. AT THIS STAGE OF THE GAME...THE BEST SOLUTION IS
TO STILL BLEND THE VARIOUS GUIDANCE PACKAGES TO DETERMINE THE
THERMAL PROFILES AND RESULTING TIMING OF THE VARIOUS PRECIP TYPES.
MOST OF THE FIELDS ARE WITHIN A DEGREE OR TWO...BUT IT WAS NOTED
THAT THE NAM WAS SUGGESTING SLIGHTLY COLDER SFC VALUES AND WARMER
THICKNESS PATTERNS ALOFT AS THE PRECIP MOVES IN. OTHERWISE...THE
DETAILED SOUNDING PROFILES INDICATE THE WARM LAYERS TO BE FAIRLY
HIGH IN THE ATMOSPHERE WITH A SUBSTANTIAL (4-5 KFT) DEPTH OF SUB
FREEZING AIR TO THE SURFACE. THIS ACTUALLY SUGGESTS THERE COULD BE
A FAIR AMOUNT OF SLEET GOING ON WITH THE SNOW AND BETWEEN THE
CHANGE TO FRZG RAIN AND RAIN. ISENTROPIC LIFT SHOULD ALLOW PRECIP
TO BREAK OUT A LITTLE SOONER THAN WHAT THE GFS/ECMWF HAD
PREVIOUSLY ADVERTISED. THE NAM WAS THE FASTEST WITH ONSET...BUT
NOW LOOKS LIKE THE 12Z GFS HAS CAUGHT UP...SO THERE WILL BE
ADJUSTMENTS TO CATEGORICAL/LIKELY POPS BY A FEW HOURS TO INDICATE
PRECIP COMING DOWN IN THE AREA BY DARK. AMOUNTS OF ANY ONE P-TYPE
LOOK TO BE LIMITED GIVEN WHAT IS EXPECTED TO BE ONLY A SHORT
AMOUNT OF RESIDENT TIME FOR THE PHASE CHANGES. MOST AREAS SHOULD
SEE ONLY A COUPLE INCHES OR LESS OF SNOW/SLEET...AND A GLAZE OF
ICE ACCRETION. WARM AIR ALOFT QUICKLY EXCEEDS 3 DEG CELSIUS WHICH
CAN INDICATE THE RAIN IS WARM AND WILL HAVE DIFFICULTY ACCRETING
ON SURFACES. STILL...A FZRA EVENT IS NOTHING TO SNEEZE AT AND
PREPARATIONS TO MITIGATE THE TRAVEL HAZARD SHOULD BE PLANNED FOR
THIS WEEKEND.
BEHIND THIS SYSTEM...A SHORT...MILD SPELL IS EXPECTED IN A NARROW
WARM SECTOR ON SUNDAY WITH A FEW RAIN SHOWERS AS THE SYSTEM DRY
SLOT PUSHES OVERHEAD. THEN...A RETURN TO THE ARCTIC AIR IS LIKELY
AND THE PATTERN SUGGESTS THERE COULD BE ANOTHER ROUND OF
SIGNIFICANT LAKE EFFECT POURING OFF THE EASTERN AND SOUTHEASTERN
SHORES OF LAKE ONTARIO AND INTO THE SYRACUSE-ROME-UTICA AREAS FROM
SUNDAY NIGHT THROUGH MONDAY NIGHT. WE HAVE FAIRLY GOOD CONFIDENCE
IN THIS EVENT OCCURRING...AND HAVE BUMPED UP POPS IN THE LAKE BELT
ZONES DURING THAT TIME.
NORTHWEST WINDS SHOULD ALSO BEGIN CRANKING UP WITHIN THE COLD
ADVECTIVE AND UNSTABLE REGIME...WITH A POTENTIAL FOR SUSTAINED
WIND SPEEDS IN THE 15-25 MPH WITH GUSTS INTO THE 30S FROM SUN
NIGHT INTO MONDAY.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
LAKE EFFECT EVENT WILL PROBABLY BE ONGOING AT THE BEGINNING OF
THIS PERIOD...ONLY TO BE INTERRUPTED BY A PASSING UPPER WAVE AND
CLIPPER TYPE SURFACE LOW ON TUESDAY AS INDICATED BY BOTH ECMWF AND
GFS. THIS WILL LIKELY MEAN A CHANCE FOR WIDESPREAD LIGHT SNOW OF A
FEW INCHES. EVEN COLDER AIR USHERS IN ON THE BACKSIDE OF THAT LOW
WITH A CONTINUATION OF BROAD CYCLONIC FLOW ALOFT OVER THE AREA. A
STRONG 1040-1045 MB HIGH TO OUR WEST AND COLD NORTHWEST BOUNDARY
LAYER FLOW WILL ONCE AGAIN REKINDLE THE LAKE EFFECT SNOWS AND
UPSLOPE INSTABILITY SNOW SHOWERS THROUGH NEXT THURSDAY.
GENERALLY FOLLOWED THE WPC GUIDANCE GRIDS WITH MINOR ADJUSTMENTS
TO POPS FOR LAKE EFFECT.
COLDER THAN NORMAL ALL NEXT WEEK AND UNSETTLED SEEMS TO BE THE
OVERALL THEME.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
A SFC TROF WILL PASS THROUGH THE AREA LATE TONIGHT AND BRING A
PERIOD OF LAKE EFFECT SNOW SHOWERS TO THE KRME/KSYR TERMINALS. AT
KRME, RESTRICTIONS NEAR THE ALT MIN CONDITION WILL BE LIKELY FROM
10Z-16Z WITH JUST LIGHT SNOW SHOWERS AND MVFR CIGS AFTERWARDS AS
THE BAND DROPS SOUTH. AT KSYR, IFR SNOW SHOWERS ARE LIKELY FROM
13Z-18Z THEN JUST LIGHT SNOW SHOWERS AND MVFR CIGS AS THE BAND
WEAKENS AND DROPS SOUTH. REST OF TERMINALS VFR WITH CIGS DROPPING
TO AROUND 4K FT LATE TONIGHT. AT KITH, FLURRIES AND MVFR CIGS LOOK
LIKELY AFTER 09Z UNDER NW FLOW.
SOUTHWEST WINDS AT 08-12 KNOTS WITH GUSTS TO 18 KNOTS BECOMING WNW
MID MORNING FRIDAY AT 10-15 KNOTS WITH GUSTS AROUND 20 KNOTS.
OUTLOOK...
SAT/SAT NGT...BECOMING IFR WITH SNOW DEVELOPING, CHANGING TO
WINTRY MIX AND OCNL RAIN/FRZG RAIN OVERNIGHT.
SUN...VFR. SCT RAIN SHOWERS.
MON...MVFR. SCT SNOW SHOWERS.
TUE...IFR RESTRICTIONS IN SNOW SHOWERS, ESPECIALLY RME-SYR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST FRIDAY FOR NYZ018-036-
037.
LAKE EFFECT SNOW WARNING UNTIL 7 PM EST FRIDAY FOR NYZ009.
&&
$$
SYNOPSIS...PVF
NEAR TERM...DJP/PVF
SHORT TERM...JAB
LONG TERM...JAB
AVIATION...RRM
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1242 AM EST WED DEC 31 2014
.SYNOPSIS...
A WESTERLY FLOW OF COLD AIR ACROSS LAKE ONTARIO WILL DEVELOP LAKE
EFFECT SNOW TONIGHT WHICH WILL IMPACT NORTHERN ONEIDA COUNTY. MUCH
OF THE REST OF THE AREA WILL REMAIN DRY WITH ONLY SCATTERED SNOW
SHOWERS AND FLURRIES FROM TIME TO TIME.
&&
.NEAR TERM /THROUGH TODAY/...
820 PM UPDATE...
LAKE EFFECT SNOW BAND IS SHOWING ITS FIRST SIGNS OF ORGANIZATION
OVER NORTHEASTERN LAKE ONTARIO. MADE SLIGHT CHANGES TO THE GRIDS
AND TO THE WSW TEXT TO BRING THE STEADY SNOW INTO NORTHWESTERN
ONEIDA COUNTY SOMETIME BETWEEN 11 PM AND 2 AM. NAM AND RAP RADAR
OUTPUT SUGGEST THIS IS A LIKELY TIME WINDOW.
THE BAND WILL FLUCTUATE QUITE A BIT OVERNIGHT, SO NOT CONFIDENT
THAT ACCUMULATIONS WILL BE SIGNIFICANT BY MORNING. THE BAND SHOWS
BETTER ALIGNMENT AND A STEADIER STATE AFTER SUNRISE.
4 PM UPDATE...
AFTER A FINAL BURST...NW FLOW LE EVENT OVER THE CNTRL ZONES IS
FINALLY WINDING DOWN. ALREADY EVIDENCE OF BACKING FLOW OVER WRN NY
WHICH WILL END THE CNTRL NY SNOW...AND BEGIN TO DVLP THE SINGLE
BAND LE EVENT XPCTD LTR TNGT AND WED. MODELS AND FCST OFFICES IN
GNRL AGREEMENT ON THE IDEA THAT A SINGLE BAND WILL DVLP AFT 00Z.
DFCLTY IS IN THE PLACEMENT OF THE BAND WITH A MEAN FLOW ARND
260-270 WHICH SHD JUST CLIP THE POINTS IN NRN ONEIDA COUNTY.
ALSO...MODEL FCSTD REFLECTIVITY AND QPF HAS A LIMITED INLAND
EXTENT OF THE HEAVIER BANDS. FOR THAT REASON...XPCT THE HEAVIEST
SNOW IN THE FAR NE CORNER OF NYZ009...WITH LESSER AMTS BUT STILL
ARND WARNING CRITERIA OVER THE NW. TIMING BRINGS THE BAND INTO THE
WARNING AREA BETWEEN 03Z AND 06Z. BAND MAY BRIEFLY LFT NORTH ARND
DAYBRK AS A WV ZIPS BY BEFORE SETTLING BACK IN THE NRN PARTS OF
ONEIDA FOR MUCH OF THE REST OF THE DAY. LOOKS LIKE THE BAND LFTS
OUT FOR GOOD AFT 21Z.
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY/...
SOUTHWEST FLOW CONTS WED NGT INTO THU KEEPING LAKE ERIE AND
ONTARIO BAND OUT OF THE AREA. SOME LIFT OVER THE TERRAIN...ESP THE
WRN CATS...COULD GENERATE SOME LGTR FLURRIES AT TIMES...AND THE
FINGER LAKES COULD SEE A BOT OF LGT SNOW SHWR ACTIVITY AT THE EDGE
OF THE LE.
SHRT WV THU NGT AND EARLY FRI WILL BRING A MORE NWLY FLOW AND A
RE-ENFORCING SHOT OF COLD AIR. THIS SHD HELP BRING MORE WIDESPREAD
SNOW SHWRS AND FLURRIES TO THE FCST AREA LATE THU NGT AND ON FRI.
WITH THE BROAD TROFF OVER THE AREA AND ARCTIC SOURCE REGION FOR
OUR AIR...TEMPS SHD AVG BLO NRML THRU THE SHRT TERM PD.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
230 PM UPDATE...
HIPRES WL START OFF THE LONG TERM PORTION OF THE FCST. 1040MB SFC
HIGH WL RESULT IN COLD-AIR DAMMING BFR NEXT STORM SYSTEM MVS IN FOR
LATE IN THE WEEKEND. H5 S/WV EJECTS OUT OF THE SRN PLAINS ON
SATURDAY AND LOOKS TO PHASE WITH WV DROPPING DOWN THRU THE UPR
MIDWEST. MED RANGE MODELS COMING INTO BETTER AGREEMENT WITH SFC
CYCLOGENESIS OCCURRING IN VICINITY OF GREAT LKS 06Z SUNDAY.
MOISTURE WL ENTER CWA AFT 18Z SAT IN THE FORM OF RAIN/SNOW, MAINLY
SNOW ACRS THE COLD-AIR DAMMED ERN ZONES. WARM AIR WRAPS IN RAPIDLY
LATE SAT NGT WITH A WINTRY MESS EXPECTED THRU 12Z SUN BFR DRY SLOT
WORKS IN.
AFT SYSTEM DEPARTS JUST EXPECTING WRAP-ARND SHOWERS ON SUNDAY. WITH
COLD-AIR FILTERING IN BHND EXPECT A VRY GRADUAL CHANGEOVER TO SNOW
SHOWERS THRU THE AFTN. BY 00Z MONDAY JUST EXPECT LK EFFECT SNOW
SHOWERS THROUGH THE END OF THE LONG TERM.
TEMPS WL BE TRICKY THRU THE PD. TEMPS WL BE NEAR TO SLIGHTLY ABV
NORMAL FOR THE WEEKEND. CANNOT RULE OUT A NON-DIURNAL TEMP TREND FOR
SAT NGT AS TEMPS WARM WITH SYSTEM PASSING TO THE WEST. BHND LOW
TEMPS DROP DOWN TO BLO NORMAL VALUES AGAIN INTO EARLY NEXT WEEK.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
LAKE EFFECT CLOUDS AND SNOW SHOWERS WILL RESULT IN MAINLY LOW END VFR TO
MVFR CONDITIONS OVERNIGHT INTO WEDNESDAY FOR KRME/KSYR/KITH. AS A
BAND CONTINUES TO GET ORGANIZED OVERNIGHT EAST OF LAKE ONTARIO WE
EXPECT THE BRUNT OF THIS BAND TO STAY MAINLY NORTH OF KRME/KSYR
HOWEVER KRME WILL LIKELY BE IN AND OUT OF SNOW SHOWERS RESULTING
IN MVFR CIGS AND AT TIMES MVFR VISBYS. A PERIOD OF IFR VISBYS IS
LIKELY WEDNESDAY MORNING FOR KRME AS THE BAND BRIEFLY SHIFTS
SOUTH. KSYR SHOULD STAY DRY OVERNIGHT BUT WILL LIKELY SEE SOME
SNOW SHOWERS AT TIMES WEDNESDAY MORNING RESULTING IN MVFR
CIGS/VISBYS. EXPECT VARIABLE CONDITIONS FOR KITH AS THEY REMAIN IN
AND OUT OF FLURRIES OFF LAKE ERIE OVERNIGHT INTO WEDNESDAY MORNING
RESULTING IN MVFR CONDITIONS AT TIMES AND EVEN BRIEF IFR CIGS.
KRME/KSYR/KITH ARE EXPECTED TO ALL BE VFR BY LATE DAY WEDNESDAY AS
THE LAKE EFFECT SHIFTS NORTH WITH THE REMAINING THREE SITES
(KBGM/KELM/KAVP) EXPECTED TO STAY VFR THROUGH THE TAF PERIOD.
OUTLOOK...
WED NIGHT THRU FRI...RESTRICTIONS POSSIBLE AT TIMES FOR KRME/KSYR
DUE TO MEANDERING LAKE EFFECT -SHSN. OTHERWISE VFR IS EXPECTED.
SAT/SAT NGT...CHANCE FOR MIXED PRECIP AND ASSOCIATED RESTRICTIONS.
SUN...MVFR RESTRICTIONS POSSIBLE IN LIGHT SNOW SHOWERS BEHIND
DEPARTING SYSTEM.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...LAKE EFFECT SNOW WARNING UNTIL 7 PM EST THIS EVENING FOR
NYZ009.
&&
$$
SYNOPSIS...DGM/DJP
NEAR TERM...DGM
SHORT TERM...DGM
LONG TERM...PVF
AVIATION...PCF/RRM
AREA FORECAST DISCUSSION
NWS RALEIGH NC
906 PM EST THU JAN 1 2015
.SYNOPSIS... STRONG HIGH PRESSURE WILL EXTEND INTO THE REGION FROM
THE NORTH FRIDAY AND FRIDAY NIGHT. A DEVELOPING LOW PRESSURE SYSTEM
WILL TRACK NORTHWARD FROM THE DEEP SOUTH INTO THE OHIO VALLEY ON
SATURDAY... AND THE GREAT LAKES SATURDAY NIGHT. THE ASSOCIATED COLD
FRONT WILL CROSS OUR REGION SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 906 PM THURSDAY...
THE LATEST SATELLITE DATA INDICATED A RAPID INCREASE IN CLOUDINESS
AT SEVERAL LEVELS FROM THE WEST THIS EVENING. GIVEN THE EXTENSIVE
CLOUDINESS AND MOISTURE UPSTREAM ESPECIALLY IN THE MID AND HIGH
LEVELS... THE SKIES OVERNIGHT WILL BE MOSTLY CLOUDY TO CLOUDY. THERE
MAY BE A FEW THIN SPOTS OR BREAKS IN THE OVERCAST BUT THE CLOUDINESS
COMBINED WITH THE LIGHT SW FLOW AT 5-10 MPH SHOULD KEEP TEMPERATURES
IN CHECK. READINGS AT MID EVENING RANGED IN THE LOWER TO MID 40S
EXCEPT FOR SOME UPPER 30S WHERE THE CLOUDS WERE YET TO THICKEN UP.
TEMPERATURES SHOULD ONLY FALL OFF ABOUT 5 MORE DEGREES OR SO THEN
LEVEL OFF AS THE CLOUDS THICKEN. LOWS IN THE MID 30S TO NEAR 40
EXPECTED.
AS FOR THE PRECIPITATION CHANCES... RADAR INDICATED PATCHY LIGHT
RAIN ALREADY SPREADING GEORGIA AND MUCH OF TENNESSEE. HOWEVER...
THERE CONTINUED TO BE QUITE A BIT OF DRY AIR TO OVERCOME FROM THE
BOUNDARY LAYER THROUGH H7. MOST OF THE PRECIPITATION IS EXPECTED TO
FALL AS VIRGA THROUGH AT LEAST 12Z GIVEN THE AMOUNT OF DRY AIR TO
MOISTEN UP. THE HRRR INDICATED SOME LIGHT QPF (POSSIBLY 0.01 OR SO)
ACROSS THE SOUTH LATE.
&&
.SHORT TERM /FRIDAY AND FRIDAY NIGHT/...
AS OF 320 PM THURSDAY...
THE CLOSED LOW CENTERED NEAR THE FOUR CORNERS REGION EARLY FRIDAY
WILL SHIFT EAST REACHING THE TEXAS PANHANDLE BY SATURDAY MORNING. AT
THE SAME TIME...SURFACE HIGH PRESSURE DEVELOPS OVER THE NORTHEAST IN
RESPONSE TO THE STRONG CONVERGENT FLOW ALOFT. THIS AREA OF HIGH
PRESSURE RIDGES INTO THE CAROLINAS BY EARLY SATURDAY
MORNING...SETTING THE STAGE FOR ANOTHER COLD AIR DAMMING EVENT OVER
THE WEEKEND. PRECIPITATION IS LIKELY TO BE PRETTY SPOTTY ON FRIDAY
MORNING GIVEN THE WEAK FORCING FOR ASCENT AND LARGELY FOCUSED TO THE
WEST AND SOUTH OF GREENSBORO AND SANFORD. AS DEEP LAYER ISENTROPIC
LIFT INCREASES LATE FRIDAY AND FRIDAY NIGHT...EXPECT PRECIPITATION
IN THE FORM OF RAIN TO OVERSPREAD AND EXPAND ACROSS CENTRAL NC. THIS
WILL SUPPORT CHANCE POPS FRIDAY EVENING INCREASING TO LIKELY
OVERNIGHT. A COOL AIR MASS AND WIDESPREAD CLOUDINESS SHOULD KEEP
TEMPERATURES IN THE 50 TO 55 RANGE ON FRIDAY. LOWS FRIDAY NIGHT WILL
FALL INTO THE UPPER 30S TO LOWER 40S. -BLAES &&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
AS OF 220 PM THURSDAY
SATURDAY THROUGH SUNDAY NIGHT: THE UPPER LEVEL LOW OVER THE TX
PANHANDLE REGION EARLY SATURDAY WILL MIGRATE NNE INTO THE MID WEST
WHERE IT WILL MERGE WITH THE NORTHERN STREAM TROUGH BY LATE
SATURDAY. THE LOW WILL THEN BECOME MORE OF A SHORTWAVE SLIDING NE
ALONG THE EASTERN PERIPHERY OF THE TROUGH THROUGH THE GREAT LAKES AND
INTO NE CANADA BY SUNDAY NIGHT. THE MAIN TROUGH WILL LINGER OVER THE
MIDWEST ON SUNDAY...PUSHING INTO THE CAROLINAS AND FLATTENING OUT BY
MONDAY AFTERNOON. AT THE SURFACE...HIGH PRESSURE CENTERED OVER THE
NE ON SATURDAY WILL RIDGE SW INTO WESTERN NC...SETTING UP A COLD AIR
WEDGE OVER THE NW PIEDMONT. ALSO ON SATURDAY...A LOW WILL DEVELOP
OVER THE TX GULF COAST AND MOVE NNE INTO THE MID WEST AND THROUGH
THE GREAT LAKES BY SUNDAY EVENING...TRAILING A COLD FRONT BEHIND IT.
AS THE SURFACE LOW BEGINS IT TREK NNE...A WARM FRONT WILL BEGIN
LIFTING NORTHWARD THROUGH NC WHERE IT WILL IMPINGE UPON THE WEDGE
BOUNDARY. THE WEDGE WILL LIKELY REMAIN OVER THE NW PIEDMONT THROUGH
SATURDAY NIGHT...BREAKING ON SUNDAY...ALLOWING THE WARM FRONT TO
LIFT THROUGH THE REST OF CENTRAL NC FOR A BRIEF PERIOD BEFORE THE
COLD FRONTAL PASSAGE SUNDAY NIGHT. THE WARM MOIST ADVECTION AHEAD OF
THE COLD FRONT WILL BE STRONG...WHICH WILL RESULT IN TEMPS WELL
ABOVE NORMAL...ESPECIALLY IN THE SE SOUTH OF THE WARM FRONT.
HOWEVER...GIVEN THE UNCERTAINTY OF WHEN AND IF THE WEDGE WILL BREAK
AHEAD OF THE COLD FRONT...CONFIDENCE IN THE TEMPERATURES FOR SUNDAY
AND SUNDAY NIGHT IS STILL RELATIVELY LOW. THE MODELS INDICATE A FEW
HUNDRED JOULES OF CAPE ON SUNDAY AHEAD OF THE FRONT...THUS HAVE GONE
AHEAD AND ADDED A SLIGHT CHANCE FOR THUNDER INTO THE FORECAST FOR
SUNDAY AFTERNOON THROUGH APPROX MIDNIGHT. THE MODELS ARE IN BETTER
AGREEMENT WITH THE TIMING OF THE COLD FRONT...WHICH WILL PUSH
THROUGH THE ENTIRE AREA BY 12Z MONDAY. KEEPING IN MIND THE LOW
CONFIDENCE IN TEMPS MENTIONED ABOVE...EXPECT HIGHS AND LOWS SATURDAY
AND SATURDAY NIGHT GENERALLY IN THE MID 40S NW TO MID 50S. THE
TEMPERATURES SHOULD GRADUALLY RISE OVERNIGHT SATURDAY TO UPPER 40S
NW TO LOW 60S SE BY 12Z SUNDAY...INCREASING FURTHER TO HIGHS AROUND
60 DEGREES NW TO AROUND 70 DEGREES SE ON SUNDAY. LOWS SUNDAY NIGHT
MAINLY IN THE MID 30S NW TO LOW 40S SE.
MONDAY THROUGH THURSDAY: EXPECT GENERALLY FAIR/DRY WEATHER TO RETURN
ON MONDAY BEHIND THE COLD FRONT...WITH AN ARCTIC HIGH RIDGING INTO
THE AREA AS THE CENTER OF THE HIGH MOVE EAST THROUGH THE VIRGINIAS.
EXPECT BELOW NORMAL TEMPERATURES GRADUALLY DECREASING FROM MONDAY...
MID 40S NW TO LOW 50S SE...TO THURSDAY...UPPER 30S NORTH TO AROUND
40 DEGREES SOUTH.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
AS OF 715 PM THURSDAY...
MID AND HIGH CLOUDS WILL CONTINUE TO INCREASE AND THICKEN OVERNIGHT
IN ADVANCE OF THE UPPER LOW OVER THE SOUTHWEST US. CONFIDENCE IS
HIGH THAT VFR CONDITIONS WILL PERSIST THROUGH THE 24 HOUR PERIOD
ENDING AT 00Z SATURDAY WITH CEILINGS LOWERING TO THE 5 TO 8KFT
RANGE. WEAK SHORTWAVE IMPULSES EMBEDDED IN THE WESTERLY FLOW ALOFT
COULD RESULT IN SOME SPOTTY-VERY LIGHT RAIN ACROSS THE AREA AROUND
DAYBREAK...HOWEVER IT SHOULD PROVE OF LITTLE CONSEQUENCE WITH NO
VSBY/CIG RESTRICTIONS EXPECTED.
WINDS WILL REMAIN LIGHT AND VARIABLE THROUGH THE PERIOD.
OUTLOOK...ADVERSE AVIATION CONDITIONS ARE EXPECTED TO DEVELOP FRIDAY
EVENING/NIGHT AND PERSIST THROUGH MUCH OF THE WEEKEND AS A COLD AIR
DAMMING WEDGE DEVELOPS IN ADVANCE OF AN APPROACHING COLD FRONT WHICH
MOVES THROUGH THE AREA LATE SUNDAY. THE POOREST CONDITIONS ARE
LIKELY TO PERSIST ACROSS INTERIOR PORTIONS OF THE PIEDMONT ON
SATURDAY AND SATURDAY NIGHT. FAIR WEATHER CONDITIONS ARE EXPECTED TO
RETURN ON MONDAY AND TUESDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BADGETT
NEAR TERM...BADGETT
SHORT TERM...BLAES
LONG TERM...KC
AVIATION...CBL/BLAES
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1228 PM EST WED DEC 31 2014
.SYNOPSIS...
DRY AND COOL CONDITIONS ARE EXPECTED TODAY AND NEW YEAR`S DAY AS
HIGH PRESSURE PUSHES INTO THE AREA. A WARM FRONT WILL BRING
INCREASING CLOUDS FRIDAY WITH PERIODS OF RAIN SATURDAY. MILD
TEMPERATURES WILL FOLLOW SUNDAY AHEAD OF A STRONG COLD FRONT. THE
FRONT MAY BRING A FEW THUNDERSTORMS SUNDAY AFTERNOON AND NIGHT.
CLEARING AND COLD CONDITIONS WILL OVERSPREAD THE CAROLINAS EARLY
NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 945 AM WEDNESDAY...ARCTIC HIGH PRESSURE CENTERED OVER THE HIGH
PLAINS COVERS THE EASTERN THREE-QUARTERS OF THE NATION AND IS
FEEDING DRY CHILLY AIR SOUTHWARD INTO THE COASTAL CAROLINAS. THE
BIGGEST FORECAST CHALLENGE TODAY IS ANTICIPATING THE AMOUNT AND
OPACITY OF CIRRUS THAT WILL COVER THE SKY...PARTICULARLY ACROSS THE
NORTHERN HALF OF OUR FORECAST AREA WHERE RECENT NAM AND RUC RELATIVE
HUMIDITY FORECASTS AT AND ABOVE 300 MB SHOW A GOOD DEAL OF MOISTURE
AND POTENTIAL CLOUDINESS.
VISIBLE SATELLITE SHOWS CIRRUS ACROSS ALL BUT GEORGETOWN AND
WILLIAMSBURG COUNTY. ALTHOUGH THE SATELLITE PERSPECTIVE DOES NOT
LOOK IMPRESSIVE...A PEEK OUT THE WINDOW SHOWS THIS CIRRUS IS
SURPRISINGLY OPTICALLY DENSE AND IS BLOCKING OUT A GOOD DEAL OF
SUNLIGHT. I HAVE SHAVED OFF A DEGREE OR TWO FROM FORECAST HIGH
TEMPERATURES ACROSS SE NORTH CAROLINA AND THE DILLON-BENNETTSVILLE
REGION OF SOUTH CAROLINA...WITH LITTLE CHANGE MADE ELSEWHERE. THIS
UPPER LEVEL MOISTURE IS ADVECTING EASTWARD ALONG THE SOUTHERN EDGE
OF A 170 KNOT JET STREAK EXTENDING ACROSS THE OHIO VALLEY AND THE
NORTHERN MID-ATLANTIC STATES.
DEWPOINTS SHOULD STEADILY FALL THROUGHOUT THE DAY REACHING THE MID
TO UPPER 20S OVER THE NEXT FEW HOURS FOR MOST AREAS.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 330 AM WEDNESDAY...BEGINNING OF THE MEDIUM RANGE PERIOD
LOOKS TO BE COOL AND DRY AS SURFACE RIDGE ACROSS THE SE AND H5
ZONAL FLOW KEEP REGION DRY AND COOL. MOISTURE STARTS TO INCREASE
ACROSS THE REGION BY FRIDAY MORNING WITH CLOUDS MOVING IN FROM THE
WEST/SOUTHWEST IN RESPONSE TO DIGGING TROF AND H5 CUT OFF LOW
ACROSS THE 4 CORNERS AREA AND SW FLOW OUT OF THE GULF. START TO
INCREASE CLOUD COVER AND INTRODUCE SLIGHT CHANCE OF PCPN DURING
THE DAYLIGHT HOURS. RAMP UP POPS BY EVENING INTO CHANCE CATEGORY
AND THIS SHOULD BE THE RULE FOR THE WEEKEND AS H5 LOW ACROSS THE
SW EJECTS TO THE E THEN NE AND BECOMES AN OPEN WAVE. HIGH PRESSURE
EAST OF FL INTERACTS WITH THIS LOW AND INCREASED JET STREAMS GULF
MOISTURE ACROSS THE SE INTO THE CAROLINAS. TEMPS MODERATE TO NEAR
CLIMO BY FRIDAY.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 330 AM WEDNESDAY...WEEKEND STAYS UNSETTLED BUT MILD AS SW
FLOW ALOFT AND AT THE SURFACE TRANSPORTS MILDER AIR INTO THE
REGION AS SURFACE LOW TO OUR WEST HEADS TO THE GREAT LAKES.
COASTAL TROUGH MOVES ONSHORE BY SUNDAY BOOSTING TEMPS WELL INTO
THE 60S AND PERHAPS SOME LOWER 70S READINGS. WITH THIS CANNOT RULE
OUT A CHANCE OF A RUMBLE OR TWO OF THUNDER SUNDAY AND SUNDAY NIGHT
AS INCREASED LOW LEVEL JET INCREASES INSTABILITY ABOVE THE
SURFACE. EVEN THOUGH FORECASTING LESS THAN 1/2 INCH OF PCPN WOULD
NOT BE SURPRISED TO SEE SOME ISOLATED HIGHER AMOUNTS AS TROUGH
INTERACTS WITH ADVANCING COLD FRONT ON SUNDAY. I DO NOT EXPECT A
TOTAL WASHOUT OVER THE WEEKEND AS WE WILL SEE SOME DRY PERIODS
MIXED IN WITH THE OCCASIONAL LIGHT RAIN. THE UNSETTLED PERIOD WILL
END LATE SUNDAY EARLY MONDAY AS A COLD FRONT SWEEPS INTO THE
REGION AND DRYS OUT THE AREA. EXPECT COOLER WEATHER TO USHER BACK
IN TO THE AREA NEXT WEEK AND THE POSSIBILITY OF ANOTHER SHOT OF
RAIN TOWARDS THE END OF THE PERIOD AS GFS DEVELOPS A LOW OFF THE
SE COAST ALONG A COASTAL TROUGH. SO BRIEF PERIOD OF MILD
TEMPERATURES OVER THE WEEKEND WILL COME TO AN END MONDAY. H5
PATTERNS SHOWS A FULL LATITUDE TROUGH DEVELOPING ACROSS THE
CENTRAL PORTION OF THE U.S. AND MOVING EASTWARD BY THE END OF THE
PERIOD.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 18Z...VFR THIS TAF VALID PERIOD. SCT HIGH CLOUDS TODAY WITH
SCT MID/BKN HIGH CLOUDS TOWARDS THE LATTER PART OF THE PERIOD. LIGHT
N WINDS WILL BECOME CALM EARLY THIS EVENING. DESPITE EXCELLENT
RADIATIONAL COOLING CONDITIONS NOT EXPECTING ANY FOG ISSUES TONIGHT
WITH A DRY AIRMASS IN PLACE. AFTER SUNRISE LGT/VRBL WINDS EXPECTED.
EXTENDED OUTLOOK...VFR INTO FRI. CHANCE OF RAIN AND MVFR/TEMPO IFR
CONDITIONS FRI NIGHT THROUGH SUN. BECOMING VFR LATE SUN. VFR MON.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 945 AM WEDNESDAY...ARCTIC HIGH PRESSURE OVER THE HIGH PLAINS
CONTROLS THE WEATHER OVER THE EASTERN THREE-QUARTERS OF THE NATION.
NORTHERLY WINDS ON THE EASTERN PERIPHERY OF THIS HIGH WILL CONTINUE
THROUGH TONIGHT. WIND SPEEDS ARE AS STRONG AS THEY`LL BE THE REST OF
THE DAY RIGHT NOW...AND GRADUALLY DIMINISHING SPEEDS ARE EXPECTED
THIS AFTERNOON INTO TONIGHT.
SEAS ARE CURRENTLY 4 FEET AT THE FRYING PAN SHOALS BUOY AND 1-4 FEET
AT VARIOUS LOCATIONS WITHIN THE NEARSHORE WATERS DEPENDING ON THE
DEGREE OF SHOALING/BLOCKING DUE TO THE SHALLOW WATERS ON FRYING PAN
SHOALS. THE BULK OF THE WAVE ENERGY IS DUE TO A 8-9 SECOND NE SWELL
BEING PRODUCED BY THE NORTHERLY WINDS BEHIND LOW PRESSURE IN THE
CENTRAL ATLANTIC. THE LOCAL SWAN MODEL ACTUALLY SHOWS THIS QUITE
WELL...AND THE MAJOR CHANGES I HAVE MADE TO FORECAST SEA HEIGHTS
OVER THE NEXT 24 HOURS ARE THE RESULT OF INCORPORATING THE SWAN
MODEL INTO OUR FORECAST. THE LARGEST ADJUSTMENTS IN THE FORECAST
WERE ALONG THE BRUNSWICK AND UPPER HORRY COUNTY COASTLINE WHERE SEA
HEIGHT FORECASTS HAVE BEEN SLASHED BY ABOUT HALF...VERIFIED BY
CURRENT DATA FROM THE SUNSET BEACH NEARSHORE BUOY.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 330 AM WEDNESDAY...PREVIOUS DISCUSSION LOOKS GOOD AND SEE
NO REASON TO CHANGE AT THIS POINT...HIGH PRESSURE WILL CONTINUES
TO SLOWLY BUILD IN ACROSS THE WATERS WEDNESDAY INTO THURSDAY.
NORTHERLY WINDS 10 TO 15 KTS WILL SUBSIDE TO AROUND 10 KTS LATE
OVERNIGHT WEDNESDAY INTO THURSDAY BECOMING NORTHEASTERLY FOR THE
REMAINDER OF THE PERIOD. SEAS 2 TO 3 FT..WITH 4 FOOTERS POSSIBLE
IN THE EXTREME OUTER WATERS...BECOMING GENERALLY 1 TO 3 FT INTO
THURSDAY.
LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 330 AM WEDNESDAY...WINDS AND SEAS START TO BUILD OVER THE
COASTAL WATERS INTO AND THE THROUGH THE WEEKEND AS GRADIENT
STARTS TO INCREASE IN RESPONSE TO A COASTAL TROUGH AND ADVANCING
COLD FRONT TO OUR WEST. SEAS WILL BUILD TO AROUND 5 TO 6 FEET ON
SUNDAY ACROSS THE OUTER WATERS WITH 2-4 FEET INLAND...WILL NEED TO
MONITOR FOR POSSIBLE SCA AS SW WINDS OF 15-20 KT AND SOME SLIGHT
CHOP TO THE SEAS. WINDS SUNDAY AFTERNOON INTO EVENING START TO
VEER TO THE W THEN NW AND ABATE A BIT BEFORE KICKING UP AGAIN
AFTER FROPA SUNDAY NIGHT EARLY MONDAY. AGAIN THE THREAT OF SOME
CONVECTION IS BEST ON SUNDAY AND SUNDAY NIGHT ACROSS THE WATERS.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...TRA
SHORT TERM...MAC
LONG TERM...MAC
AVIATION...MRR
AREA FORECAST DISCUSSION
NWS BISMARCK ND
137 AM CST WED DEC 31 2014
.UPDATE...
ISSUED AT 137 AM CST WED DEC 31 2014
NORTHWEST FLOW ALOFT THIS MORNING WITH DEEP LOW PRESSURE TO OUR
NORTHEAST OVER THE HUDSON BAY. TIGHT PRESSURE GRADIENT AROUND THE
LOW EXTENDS ACROSS THE NORTHERN PLAINS...AND CREATES A RATHER
ROBUST SOUTHWEST WIND. WEAK WAA COUPLED WITH THIS STRONG MIXING
WIND RESULTS IN TEMPERATURES STEADY OR RISING ACROSS WEST AND
CENTRAL NORTH DAKOTA.
WE ARE BARELY REACHING WIND CHILL CRITERIA SOME LOCATIONS AND NOT
AT ALL MOST PLACES. WILL KEEP HEADLINES AS IS FOR THIS UPDATE BUT
WILL BE CANCELING ALL HEADLINES WITH THE NEXT FORECAST UPDATE 3-4
AM CST.
LARGE AREA OF LOW STRATUS OVER SOUTH CENTRAL CANADA IS SURGING
SOUTHWARD TOWARDS THE NORTHERN PLAINS. TIME OF ARRIVAL PUTS THE
LEADING EDGE OF THE CLOUDS ACROSS THE INTERNATIONAL BORDER BY
AROUND 9-10Z AND ACROSS ALL OF WEST AND CENTRAL NORTH DAKOTA BY
18Z AT THE LATEST. THUS SIGNIFICANT CHANGES WERE MADE TO SKY GRIDS
FOR THIS UPDATE. LATEST RAP AND GFS HAVE THE BEST HANDLE ON THE
CLOUDS. STRATUS LOOKS TO LINGER OVER MY NORTH CENTRAL AND EAST
THROUGH MUCH OF WEDNESDAY....WITH MODELS INDICATING SOME EROSION
OVER THE WEST/CENTRAL WED AFTERNOON. OPTED TO THROW IN ISOLATED
FLURRIES AS WELL THIS MORNING WITH NUMEROUS OBSERVING SITES IN
SOUTH CENTRAL CANADA REPORTED LIGHT SNOW BUT WITH VISIBILITIES
P6SM. HELD OFF ON AFTERNOON FLURRIES FOR NOW.
UPDATE ISSUED AT 931 PM CST TUE DEC 30 2014
WINDS ARE BEGINNING TO INCREASE OVER NORTHWESTERN NORTH DAKOTA IN
RESPONSE TO LOW PRESSURE ENTERING NORTHERN MANITOBA. EVEN THOUGH
THE WIND SPEEDS ARE INCREASING...SO ARE THE AMBIENT AIR TEMPERATURES
DUE TO VERTICAL MIXING.
WIND CHILLS ARE STILL EXPECTED TO DIP TO NEAR 30 BELOW ZERO OVER
WESTERN AND CENTRAL NORTH DAKOTA TONIGHT. HOWEVER...IT IS LIKELY
THAT NORTHWESTERN AND PARTS OF NORTH CENTRAL NORTH DAKOTA HAVE
ALREADY OBSERVED THEIR OVERNIGHT LOWS...WITH INCREASING AMBIENT
AIR TEMPERATURES FORECAST NORTH THROUGH THE REST OF THE NIGHT DUE
TO INCREASING WIND SPEED/VERTICAL MIXING.
ONLY MADE MINOR ADJUSTMENTS TO THE HOURLY TEMP/DEWPOINT/WIND GRIDS
BASED ON CURRENT OBS/TRENDS. THE CURRENT WIND CHILL ADVISORY LOOKS
TO BE IN GOOD SHAPE AS WELL. THE UPDATED PRODUCTS HAVE BEEN SENT.
UPDATE ISSUED AT 533 PM CST TUE DEC 30 2014
NO MAJOR UPDATES WERE REQUIRED TO THE ONGOING FORECAST. THE
CURRENT WIND CHILL ADVISORY FOR TONIGHT IS IN GOOD SHAPE. ONLY
ADJUSTED THE HOURLY SENSIBLE WEATHER GRIDS BASED ON CURRENT
OBS/TRENDS. THE FRESHENED UP PRODUCTS HAVE BEEN SENT.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 312 PM CST TUE DEC 30 2014
SEVERAL AREAS OF CONCERN TONIGHT. TEMPERATURES ONLY WARMED TO
AROUND ZERO MOST AREAS TODAY AND EVENING TEMPERATURES LIKELY TO
FALL QUICKLY INITIALLY. STRENGTHENING MID LEVEL FLOW ALONG WITH
SURFACE PRESSURE GRADIENT ASSOCIATED WITH DEPARTING ARCTIC HIGH
WILL BRING INCREASING WESTERLY WINDS. THIS CAUSES WIND CHILL
ISSUES AGAIN TONIGHT WITH VALUES FALLING TO 25 TO 30 BELOW MOST
AREAS. ALTHOUGH NOT AS WIDESPREAD AND COLD AS LAST NIGHT...IN CO-
ORDINATION WITH SURROUNDING OFFICES WILL ISSUE ANOTHER WIND CHILL
ADVISORY TONIGHT. WARMING AFTER MIDNIGHT WILL BE COUNTERBALANCED AT
FIRST WITH INCREASING WINDS. EVEN THOUGH 850MB WINDS ARE 50KTS
ACROSS THE REGION TONIGHT DO NOT THINK THIS WILL NAVIGATE TO THE
SURFACE. STRONG WARM ADVECTION WILL LIMIT THE POTENTIAL FOR
MOMENTUM TRANSFER. HOWEVER THINK WITH 20 TO 30 MPH WIND GUSTS
NORTH CENTRAL AND SOUTHWEST THERE WILL BE SOME PATCHY BLOWING
SNOW TONIGHT. WEDNESDAY BREEZY AND NOT AS COLD.
.LONG TERM...(NEW YEARS EVE WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 312 PM CST TUE DEC 30 2014
NEW YEARS EVE: EXPECTING WESTERLY WINDS AT 10 TO 15 MPH TO PERSIST
THROUGH THE NIGHT. NEUTRAL TEMPERATURE ADVECTION WITH THE STATE
BETWEEN SYSTEMS - THUS TEMPERATURES SHOULD NOT DROP MUCH FROM THE
DAYTIME HIGHS ON WEDNESDAY...WITH EXPECTED LOW TEMPERATURES FROM
NEAR 10 ABOVE TO 15 ABOVE. LOOK FOR INCREASING CLOUDS FROM NORTH TO
SOUTH WITH THE APPROACH OF AN UPPER LEVEL SHORTWAVE MOVING SOUTHEAST
TOWARDS NORTH DAKOTA FROM SASKATCHEWAN. AFTER MIDNIGHT THERE IS A
CHANCE OF LIGHT SNOW...MAINLY ACROSS THE BOTTINEAU/TURTLE MOUNTAINS
AREA TO THE NORTHERN JAMES VALLEY.
NEW YEARS DAY: THE UPPER LEVEL SHORTWAVE CONTINUES MOVING SOUTHEAST
AS A WEAK COLD FRONT DROPS SOUTH ACROSS THE STATE. A SLIGHT CHANCE
OF LIGHT SNOW WITH VERY LIGHT ACCUMULATIONS EXPECTED. HIGHS SHOULD
RANGE FROM THE TEENS NORTH CENTRAL THROUGH JAMESTOWN...TO THE UPPER
20S IN THE SOUTHWEST.
NORTHWESTERLY FLOW REMAINS OVER THE REGION THROUGH REST OF THE
PERIOD WITH A VARIETY OF DISTURBANCES SLIDING THROUGH. THE
NEXT...AND MORE SIGNIFICANT...WAVE APPROACHES THE AREA ON FRIDAY
INTO SATURDAY. MODELS HAVE BEEN HAVING SOME TROUBLE ON THE EXACT
PLACEMENT OF SOME KEY FEATURES...BUT THE MAIN POINT IS THAT THERE IS
A RATHER GOOD CHANCE FOR SNOWFALL FRIDAY AFTERNOON THROUGH SATURDAY.
THE LATEST ESTIMATES ARE FOR 1 TO 3 INCH AMOUNTS THROUGH THIS
PERIOD. FINALLY...ANOTHER SHORT WAVE IS EXPECTED TO PUSH THROUGH THE
NORTHERN PLAINS ON MONDAY. AGAIN...POSITION OF SYSTEM IS STILL IN
QUESTION BUT MEASURABLE SNOWFALL IS POSSIBLE.
TEMPERATURES WILL BE NEAR TO ABOVE AVERAGE FRIDAY...BUT LOOK FOR
BELOW AVERAGE TEMPERATURES THIS WEEKEND AND INTO EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY EVENING)
ISSUED AT 137 AM CST WED DEC 31 2014
MVFR STRATUS WILL SURGE SOUTHWARD 09-15Z ACROSS NORTH DAKOTA.
KISN-KMOT WILL SEE INCREASING LOW CLOUDS 10-12Z...AND KBIS-KJMS-
KDIK 14-16Z. STRATUS ERODES OVER WESTERN AND SOUTH CENTRAL
TERMINALS LATER WED MORNING INTO THE AFTERNOON...BUT COULD LINGER
NORTH CENTRAL AND EAST INTO WED EVENING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL 6 AM CST /5 AM MST/ EARLY THIS MORNING
FOR NDZ001>005-009>013-017>023-025-031>037-040>048-050-051.
&&
$$
UPDATE...NH
SHORT TERM...WAA
LONG TERM...JV
AVIATION...NH
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
920 AM CST WED DEC 31 2014
.UPDATE...
LET THE WIND CHILL ADVISORY EXPIRE AT 15Z AS FORECAST. READINGS
ARE PRETTY MUCH OUT OF CRITERIA NOW AND WIND CHILLS WILL SLOWLY
IMPROVE THROUGH THE REMAINDER OF THE MORNING AS TEMPS CLIMB.
DOWNSLOPE WIND EVENT IS ONGOING WITH PEEVER HAVING GUSTED TO 61
MPH EARLIER THIS MORNING. SPEEDS ARE SLOWLY WINDING DOWN AND
EXPECT BY NOON THINGS WILL HAVE QUIETED DOWN DRAMATICALLY. PEEVER
WEB CAM DOES SHOW A PATCH OF BLOWING SNOW AND LOW VSBY...BUT LOOKS
RATHER LOCALIZED. WILL CONTINUE WITH THE SPS STATEMENT CONCERNING
STRONG WINDS. HRRR AND HOP WRF PICKING UP ON THIS NICELY AND SHOW
SPEEDS IMPROVING BY 18Z AS STRONGEST 925 MB WINDS SHIFT OFF TO THE
SOUTH AND EAST.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH FRIDAY
CURRENT MSAS SURFACE PRESSURE FALLS RANGE FROM 4 TO 5 MB AS A
TROUGH DROPS SOUTH OUT OF CANADA. WARM AIR ADVECTION AHEAD OF
THIS TROUGH HAS ALLOWED TEMPERATURES TO STEADY...AND IN SOME
LOCATIONS...RISE A FEW DEGREES THIS MORNING. WIND SPEEDS AT MOST
LOCATIONS ARE BETWEEN 10 AND 15 MPH...ALLOWING SCATTERED OBS
ACROSS THE REGION TO REPORT WINDCHILL READINGS WITHIN ADVISORY
CRITERIA. OTHERS ARE VERY CLOSE TO CRITERIA...SO CONTINUED THE
ADVISORY AS PLANNED. ALSO LEFT THE MENTION OF BLOWING SNOW IN THE
LEE OF THE SISSETON HILLS. THE RWIS STATION NEAR PEEVER WAS
REPORTING WIND GUSTS UP TO 40 MPH BETWEEN 11PM AND
MIDNIGHT...HOWEVER...HAVE SINCE DECREASED TO THE 20 MPH RANGE.
WEBCAMS HAVE NOT INDICATED ANY SIGNIFICANT TRAVEL ISSUES.
TODAY...WINDS WILL SWITCH AROUND TO THE WEST NORTHWEST BEHIND THE
SURFACE TROUGH. TEMPERATURES WILL BE WARMER...RELATIVELY
SPEAKING...WITH HIGHS IN THE TEENS AND 20S.
A SECONDARY COLD FRONT WILL SWEEP ACROSS THE NORTHERN PLAINS
LATER ON THURSDAY. ALTHOUGH WARM AIR ADVECTION AHEAD OF THIS FRONT
SHOULD ALLOW AFTERNOON TEMPS TO RISE INTO THE 20S AND 30S. ANY
PRECIPITATION ASSOCIATED WITH THIS FRONT APPEARS TO REMAIN NORTH
OF THIS CWA...HOWEVER FLURRIES MAY BE POSSIBLE ACROSS THE FAR
NORTHEAST CWA.
HIGH PRESSURE SLIDES ACROSS THE REGION THURSDAY NIGHT AND FRIDAY
MORNING...BEFORE RETURN FLOW TAKES OVER FRIDAY AFTERNOON.
.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY
THERE CONTINUES TO BE SIGNIFICANT INCONSISTENCY WITH THE MODELS IN
THE EXTENDED PERIOD...BUT IT DOES LOOK AS THOUGH THERE IS
POTENTIAL FOR A COUPLE OF SYSTEMS TO AFFECT THE AREA. THE FIRST
WILL COME LATE FRIDAY NIGHT AND SATURDAY AS A LOW PRESSURE SYSTEM
TRACKS ACROSS THE NORTHERN PLAINS. THE GFS IS FURTHER SOUTH WITH
THE LOW...POSSIBLY BRINGING ONE TO THREE INCHES OF SNOW TO THE
NORTHEASTERN CWA...WHILE THE ECMWF IS FURTHER NORTH AND BRINGS
VERY LITTLE SNOW. THE POTENTIAL FOR THE SECOND SYSTEM COMES ON
MONDAY...BUT THE MODELS ARE VERY DIFFERENT IN THEIR DEPICTIONS.
THE GFS BRINGS A STRONGER LOW ACROSS THE CENTRAL PLAINS...THEREBY
BRINGING SNOW TO CWA. THE ECMWF HAS NO HINT WHAT SO EVER OF THE
LOW PRESSURE SYSTEM...AND THEREFORE NO PRECIPITATION. FOR THE TIME
BEING...WILL STICK CLOSE TO THE SUPERBLEND WHICH JUST HAS SOME
SCHC/CHC POPS SUNDAY NIGHT AND MONDAY.
SATURDAY WILL BE THE WARMEST DAY OF THE PERIOD WITH HIGHS IN THE
TEENS TO LOWER 20S. WILL THEN SEE COOLER AIR MOVE BACK IN WITH H85
TEMPS FALLING INTO THE UPPER TEENS TO LOWER 20S BELOW ZERO. THIS
WILL RESULT IN HIGHS MAINLY IN THE SINGLE DIGITS SUNDAY THROUGH
TUESDAY.
&&
.AVIATION...
12Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
VFR CONDITIONS WILL PREVAIL ACROSS THE AREA TODAY AND TONIGHT.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...TMT
SHORT TERM...SERR
LONG TERM...PARKIN
AVIATION...PARKIN
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION...UPDATED
NWS NASHVILLE TN
911 PM CST THU JAN 1 2015
.UPDATE...
IN LOOKING AT REGIONAL RADAR MOSIAC TRENDS...00Z KOHX SOUNDING PROFILE...
SHORT RANGE MODEL GUIDANCE...MODEL AND BUFKIT SOUNDINGS...AND SFC
OBS...LOOKS LIKE THE BEST CHANCE FOR RAINFALL WILL BE S OF THE MID
STATE REMAINDER OF EVENING AND OVERNIGHT WITH HIGHEST POPS FOR LOCATIONS
APPROACHING THE TN/KY BORDER AND FOR SRN LOCATIONS OF THE TN RIVER VALLEY
REGION OF W MID TN. BULK OF BEST POTENTIAL OF RAINFALL LOOKS TO MOVE
INTO AREA AT OR AROUND 08Z. THUS...IN GENERAL...HAVE BACKED OFF ON POPS
FROM SW TO NE ACROSS THE MID STATE THRU REMAINDER OF EVENING AND EVEN
INTO THE FIRST FEW OVERNIGHT HOURS...PUSHING BACK THE POTENTIAL FOR
MOST RAINFALL TO THE LATER PORTION OF THE EARLY MORNING HRS. WILL
CONTINUE TO MENTION THE POSSIBILITY OF A WINTRY MIX ACROSS NRN PORTIONS
OF MID STATE...HIGHLAND RIM AND NRN PORTIONS OF UPPER CUMBERLAND...TOWARD
THE LATER PORTION OF THE EARLY MORNING HRS TOO. HOWEVER...OVERALL CHANCES
OF WINTRY MIX DEVELOPING ACROSS THESE PORTIONS OF THE MID STATE DURING
THIS TIME PERIOD LOOK TO BE LESS LIKELY THAN PREVIOUSLY THOUGHT.
&&
.PREV DISCUSSION.../ISSUED 603 PM CST THU JAN 1 2015/
UPDATE...
UPDATED THE SUITE OF FORECAST PRODUCTS TO REMOVE THE THRU LATE AFTERNOON
GROUPING IN THE ZONE FORECAST PRODUCT. ADDITIONALLY...PER CURRENT RADAR
MOSAICS AND SHORT RANGE MODEL TRENDS...ONLY WENT GO WITH A SLIGHT CHANCE
OF RAIN ACROSS N CNTRL AND UPPER CUMBERLAND REGIONS ACROSS MID STATE
THRU EARLY EVENING HRS. MOST RECENT HRLY TEMP TRENDS ALSO SUPPORTING
RAISING OVERNIGHT LOWS INTO THE MID 30S ACROSS THE PLATEAU REGION.
OTHERWISE...CURRENT FORECAST AND BELOW FORECAST REASONING REMAINS ON TRACK.
PREV DISCUSSION.../ISSUED 554 PM CST THU JAN 1 2015/
UPDATE...FOR 00Z AVIATION DISCUSSION
AVIATION...
FOR THE 00Z TAFS, THERE IS LOW CONFIDENCE WITH RESPECT TO FLIGHT
CATEGORIES, PRECIPITATION TIMING, AND EVEN PRECIPITATION TYPE.
THE OVERALL TREND WILL BE FOR DETERIORATING CONDITIONS BEGINNING
OVERNIGHT.
WE DON`T THINK IT WILL RAIN THE ENTIRE TAF CYCLE, BUT PERIODS OF
LIGHT PRECIPITATION ARE EXPECTED.
HAVE MODERATE TO HIGH CONFIDENCE THAT -RA WILL BE THE
PRECIPITATION TYPE AT KBNA AND KCSV. AT KCKV, HOWEVER, CAN`T RULE
OUT A BRIEF PERIOD OF A -RA/-FZRA MIX, ESPECIALLY 08Z-14Z.
JACKSON
PREV DISCUSSION... /ISSUED 214 PM CST THU JAN 1 2015/
DISCUSSION...WEAK HIGH PRESSURE CONTINUES TO COVER MIDDLE
TENNESSEE EARLY THIS AFTERNOON WITH A VFR OVERCAST STRATOCU DECK
KEEPING A LID ON TEMPERATURES. RADAR MOSAIC SHOWS A LARGE AREA OF
MAINLY LIGHT RAIN OVER NORTHERN MS AND EXTREME SW TN, BUT GIVEN
LARGE DEW POINT SPREADS STILL IN PLACE ACROSS THE MID STATE, RAIN
WILL BE SLOW TO ARRIVE HERE. HRRR DOES SHOW SOME DEVELOPMENT
DURING THE EVENING AND OVERNIGHT, WITH MOST OF THE ACTIVITY
REMAINING IN THE RELATIVELY WARM AIR OF SOUTHERN MIDDLE TENNESSEE.
SCATTERED ACTIVITY MAY DEVELOP ACROSS OUR NORTH BEFORE 12Z, AND UP
AGAINST THE KY STATE LINE THIS PRECIPITATION MAY START OFF AS A
RA/FZRA OR RA/IP MIXTURE, BUT ACCUMULATIONS ARE NOT EXPECTED. IN
THE MEANTIME, A DEVELOPING LOW TO OUR SW WILL COME RACING NE`WD
INTO THE OZARKS BY 12Z SATURDAY, BRINGING A WARM FRONT NORTHWARD
ACROSS MIDDLE TENNESSEE SO THAT TEMPERATURES SATURDAY MAY WARM
INTO THE 60`S OFF THE PLATEAU. MODEL SOUNDINGS DO SHOW SOME
ELEVATED INSTABILITY WITH THIS SYSTEM, SO WILL INCLUDE TS IN THE
FORECAST FOR SATURDAY AND SATURDAY NIGHT. CAN`T COMPLETELY RULE
OUT A THUNDERSTORM OR TWO PRIOR TO 12Z SATURDAY, BUT THE BEST
INSTABILITY WON`T OCCUR UNTIL DURING THE DAY, SO WILL LIMIT TS TO
DAY 3 ONLY. SPC ALSO HAS US IN A GENERAL THUNDERSTORM AREA ON DAY
3, WITH FROPA OCCURRING BETWEEN 00Z AND 12Z SUNDAY. THERE WILL
LIKELY BE SOME LEFTOVER RAIN ON SUNDAY, BUT THEN LOOK FOR DRY
WEATHER FROM SUNDAY NIGHT AT LEAST THROUGH THURSDAY. TEMPERATURES
NEXT WEEK WILL REMAIN COLDER THAN NORMAL AS WE NEVER DO REALLY
ESTABLISH ANY MEANINGFUL RETURN FLOW, SO IT`S GOING TO A COLD
WEEK.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
31
AREA FORECAST DISCUSSION...UPDATED
NWS NASHVILLE TN
603 PM CST THU JAN 1 2015
.UPDATE...
UPDATED THE SUITE OF FORECAST PRODUCTS TO REMOVE THE THRU LATE AFTERNOON
GROUPING IN THE ZONE FORECAST PRODUCT. ADDITIONALLY...PER CURRENT RADAR
MOSAICS AND SHORT RANGE MODEL TRENDS...ONLY WENT GO WITH A SLIGHT CHANCE
OF RAIN ACROSS N CNTRL AND UPPER CUMBERLAND REGIONS ACROSS MID STATE
THRU EARLY EVENING HRS. MOST RECENT HRLY TEMP TRENDS ALSO SUPPORTING
RAISING OVERNIGHT LOWS INTO THE MID 30S ACROSS THE PLATEAU REGION.
OTHERWISE...CURRENT FORECAST AND BELOW FORECAST REASONING REMAINS ON TRACK.
&&
.PREV DISCUSSION.../ISSUED 554 PM CST THU JAN 1 2015/
UPDATE...FOR 00Z AVIATION DISCUSSION
AVIATION...
FOR THE 00Z TAFS, THERE IS LOW CONFIDENCE WITH RESPECT TO FLIGHT
CATEGORIES, PRECIPITATION TIMING, AND EVEN PRECIPITATION TYPE.
THE OVERALL TREND WILL BE FOR DETERIORATING CONDITIONS BEGINNING
OVERNIGHT.
WE DON`T THINK IT WILL RAIN THE ENTIRE TAF CYCLE, BUT PERIODS OF
LIGHT PRECIPITATION ARE EXPECTED.
HAVE MODERATE TO HIGH CONFIDENCE THAT -RA WILL BE THE
PRECIPITATION TYPE AT KBNA AND KCSV. AT KCKV, HOWEVER, CAN`T RULE
OUT A BRIEF PERIOD OF A -RA/-FZRA MIX, ESPECIALLY 08Z-14Z.
JACKSON
PREV DISCUSSION... /ISSUED 214 PM CST THU JAN 1 2015/
DISCUSSION...WEAK HIGH PRESSURE CONTINUES TO COVER MIDDLE
TENNESSEE EARLY THIS AFTERNOON WITH A VFR OVERCAST STRATOCU DECK
KEEPING A LID ON TEMPERATURES. RADAR MOSAIC SHOWS A LARGE AREA OF
MAINLY LIGHT RAIN OVER NORTHERN MS AND EXTREME SW TN, BUT GIVEN
LARGE DEW POINT SPREADS STILL IN PLACE ACROSS THE MID STATE, RAIN
WILL BE SLOW TO ARRIVE HERE. HRRR DOES SHOW SOME DEVELOPMENT
DURING THE EVENING AND OVERNIGHT, WITH MOST OF THE ACTIVITY
REMAINING IN THE RELATIVELY WARM AIR OF SOUTHERN MIDDLE TENNESSEE.
SCATTERED ACTIVITY MAY DEVELOP ACROSS OUR NORTH BEFORE 12Z, AND UP
AGAINST THE KY STATE LINE THIS PRECIPITATION MAY START OFF AS A
RA/FZRA OR RA/IP MIXTURE, BUT ACCUMULATIONS ARE NOT EXPECTED. IN
THE MEANTIME, A DEVELOPING LOW TO OUR SW WILL COME RACING NE`WD
INTO THE OZARKS BY 12Z SATURDAY, BRINGING A WARM FRONT NORTHWARD
ACROSS MIDDLE TENNESSEE SO THAT TEMPERATURES SATURDAY MAY WARM
INTO THE 60`S OFF THE PLATEAU. MODEL SOUNDINGS DO SHOW SOME
ELEVATED INSTABILITY WITH THIS SYSTEM, SO WILL INCLUDE TS IN THE
FORECAST FOR SATURDAY AND SATURDAY NIGHT. CAN`T COMPLETELY RULE
OUT A THUNDERSTORM OR TWO PRIOR TO 12Z SATURDAY, BUT THE BEST
INSTABILITY WON`T OCCUR UNTIL DURING THE DAY, SO WILL LIMIT TS TO
DAY 3 ONLY. SPC ALSO HAS US IN A GENERAL THUNDERSTORM AREA ON DAY
3, WITH FROPA OCCURRING BETWEEN 00Z AND 12Z SUNDAY. THERE WILL
LIKELY BE SOME LEFTOVER RAIN ON SUNDAY, BUT THEN LOOK FOR DRY
WEATHER FROM SUNDAY NIGHT AT LEAST THROUGH THURSDAY. TEMPERATURES
NEXT WEEK WILL REMAIN COLDER THAN NORMAL AS WE NEVER DO REALLY
ESTABLISH ANY MEANINGFUL RETURN FLOW, SO IT`S GOING TO A COLD
WEEK.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
31
AREA FORECAST DISCUSSION...UPDATED
NWS NASHVILLE TN
554 PM CST THU JAN 1 2015
.UPDATE...FOR 00Z AVIATION DISCUSSION
&&
.AVIATION...
FOR THE 00Z TAFS, THERE IS LOW CONFIDENCE WITH RESPECT TO FLIGHT
CATEGORIES, PRECIPITATION TIMING, AND EVEN PRECIPITATION TYPE.
THE OVERALL TREND WILL BE FOR DETERIORATING CONDITIONS BEGINNING
OVERNIGHT.
WE DON`T THINK IT WILL RAIN THE ENTIRE TAF CYCLE, BUT PERIODS OF
LIGHT PRECIPITATION ARE EXPECTED.
HAVE MODERATE TO HIGH CONFIDENCE THAT -RA WILL BE THE
PRECIPITATION TYPE AT KBNA AND KCSV. AT KCKV, HOWEVER, CAN`T RULE
OUT A BRIEF PERIOD OF A -RA/-FZRA MIX, ESPECIALLY 08Z-14Z.
JACKSON
&&
.PREV DISCUSSION... /ISSUED 214 PM CST THU JAN 1 2015/
DISCUSSION...WEAK HIGH PRESSURE CONTINUES TO COVER MIDDLE
TENNESSEE EARLY THIS AFTERNOON WITH A VFR OVERCAST STRATOCU DECK
KEEPING A LID ON TEMPERATURES. RADAR MOSAIC SHOWS A LARGE AREA OF
MAINLY LIGHT RAIN OVER NORTHERN MS AND EXTREME SW TN, BUT GIVEN
LARGE DEW POINT SPREADS STILL IN PLACE ACROSS THE MID STATE, RAIN
WILL BE SLOW TO ARRIVE HERE. HRRR DOES SHOW SOME DEVELOPMENT
DURING THE EVENING AND OVERNIGHT, WITH MOST OF THE ACTIVITY
REMAINING IN THE RELATIVELY WARM AIR OF SOUTHERN MIDDLE TENNESSEE.
SCATTERED ACTIVITY MAY DEVELOP ACROSS OUR NORTH BEFORE 12Z, AND UP
AGAINST THE KY STATE LINE THIS PRECIPITATION MAY START OFF AS A
RA/FZRA OR RA/IP MIXTURE, BUT ACCUMULATIONS ARE NOT EXPECTED. IN
THE MEANTIME, A DEVELOPING LOW TO OUR SW WILL COME RACING NE`WD
INTO THE OZARKS BY 12Z SATURDAY, BRINGING A WARM FRONT NORTHWARD
ACROSS MIDDLE TENNESSEE SO THAT TEMPERATURES SATURDAY MAY WARM
INTO THE 60`S OFF THE PLATEAU. MODEL SOUNDINGS DO SHOW SOME
ELEVATED INSTABILITY WITH THIS SYSTEM, SO WILL INCLUDE TS IN THE
FORECAST FOR SATURDAY AND SATURDAY NIGHT. CAN`T COMPLETELY RULE
OUT A THUNDERSTORM OR TWO PRIOR TO 12Z SATURDAY, BUT THE BEST
INSTABILITY WON`T OCCUR UNTIL DURING THE DAY, SO WILL LIMIT TS TO
DAY 3 ONLY. SPC ALSO HAS US IN A GENERAL THUNDERSTORM AREA ON DAY
3, WITH FROPA OCCURRING BETWEEN 00Z AND 12Z SUNDAY. THERE WILL
LIKELY BE SOME LEFTOVER RAIN ON SUNDAY, BUT THEN LOOK FOR DRY
WEATHER FROM SUNDAY NIGHT AT LEAST THROUGH THURSDAY. TEMPERATURES
NEXT WEEK WILL REMAIN COLDER THAN NORMAL AS WE NEVER DO REALLY
ESTABLISH ANY MEANINGFUL RETURN FLOW, SO IT`S GOING TO A COLD
WEEK.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
JBW/JJ
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
934 PM CST THU JAN 1 2015
.UPDATE...INCREASED POPS ACROSS CENTRAL AND WESTERN ZONES FOR THE
OVERNIGHT THROUGH 6AM GIVEN RADAR TRENDS AND OBSERVATIONS INDICATING
THE LIGHT DRIZZLE REACHING THE SURFACE. ALSO INCREASED POPS BY ABOUT
10% FOR TOMORROW GIVEN HRRR/HI-RES OUTPUT. HOURLY TEMPERATURES AND
DEWPOINTS WERE MASSAGED TO ACCOUNT FOR CURRENT TRENDS. SEE UPDATED
DISCUSSION BELOW FOR MORE DETAILS.
&&
.DISCUSSION...AREAS OF FOG AND WIDESPREAD LIGHT RAIN SHOWERS AND DRIZZLE
IS ONGOING ACROSS MUCH OF THE REGION THIS EVENING. MOIST
ISENTROPIC UPGLIDE CONTINUES TO AID IN LIGHT PRECIPITATION
DEVELOPMENT AND THIS IS EXPECTED TO PERSIST THROUGH THE OVERNIGHT.
HAVE BUMPED UP POPS ACCORDINGLY AND ADDED A FEW HUNDREDTHS MORE TO
RAINFALL ACCUMULATION TOTALS. WHILE ALL AREAS ARE ABOVE
FREEZING...AREAS IN NORTHERN EDWARDS COUNTY ARE CLOSE TO THAT MARK
WITH ROCKSPRINGS AT 34 DEGREES AND SONORA AT 32 DEGREES. ALL SHORT
TERM GUIDANCE DOES KEEP AREA ABOVE FREEZING OVERNIGHT AND DONT
EXPECT ANY FREEZING RAIN ACROSS SOUTHERN EDWARDS PLATEAU IN THIS
PARTICULAR AREA.
FOR FRIDAY MORNING AND INTO THE AFTERNOON...HI-RES AND HRRR GUIDANCE
ARE INDICATING SLIGHTLY MORE ORGANIZED RAIN SHOWER BANDING AS
INCREASED LIFT OCCURS IN ADVANCE OF SHORTWAVE TROUGH PASSAGE. SOME
OF THIS BANDING COULD HAVE EMBEDDED THUNDERSTORM ACTIVITY GIVEN
SOME SUPPORT FROM NEAR 7C H7-H5 LAPSE RATES LEADING TO 300-600
J/KG MUCAPE PER EC AND NAM. HAVE INCREASED RAINFALL AMOUNTS
UPWARD ABOUT 0.05 TO 0.1" FOR THE SOUTHERN HILL COUNTRY AND JUST
NORTH AND WEST OF THE I-35 CORRIDOR IN THE 6AM TO NOON TIME FRAME.
A SMALL BREAK LOOKS TO OCCUR DURING THE AFTERNOON BEFORE ANOTHER
ROUND OF RAIN OCCURS OVERNIGHT FRIDAY INTO SATURDAY MORNING AS THE
MAIN TROUGH AXIS MOVES OVER THE AREA AND DRIER AIR MOVES IN.
/ALLEN/
&&
.PREV DISCUSSION... /ISSUED 554 PM CST THU JAN 1 2015/
AVIATION...
/00Z TAFS/
CIGS AND VBSYS WILL NOT IMPROVE MUCH THROUGH THE FORECAST PERIOD
WITH IFR/LIFR CONDITIONS. EXPECT LIGHT RAIN/DRIZZLE AND PATCHY FOG
ACROSS THE AREA AIRPORTS AS ISENTROPIC LIFT CONTINUES TO DOMINATE
ALOFT WITH A COOLER AIRMASS AT THE SURFACE. LOW LEVEL WINDS WILL
BE FROM THE NORTH AND NORTHEAST AND EVEN VARIABLE TONIGHT INTO
FRIDAY. THERE IS A SLIGHT CHANCE FOR ISOLATED THUNDERSTORMS ACROSS
SOUTH CENTRAL TEXAS ON FRIDAY AS AN UPPER LEVEL TROUGH PUSHES
ACROSS THE DESSERT SOUTHWEST INTO THE SOUTHERN PLAINS. HOWEVER...
AT THIS TIME...OPTED TO KEEP TS OUT. WILL REVISIT DURING THE 06Z
PACKAGE.
PREV DISCUSSION... /ISSUED 328 PM CST THU JAN 1 2015/
SHORT TERM (TONIGHT THROUGH FRIDAY NIGHT)...
WITH THE FREEZING LINE NOW JUST NORTH OF THE CWA...A EVENING AND
OVERNIGHT PERIOD OF COLD LIGHT RAIN...DRIZZLE...AND FOG ARE IN
STORE. WITH VISIBILITIES NEVER REACHING ABOVE 6 SM ACROSS THE
CWA...DIDNT THINK THEY WOULD IMPROVE ANY OVER THE NEXT 24 HOURS AS
THE SAME MOISTURE LOOKS TO BE IN PLACE UNTIL THE UPPER LEVEL
SYSTEM CLEARS OUT SUNDAY. THEREFORE INCLUDED AREAS OF FOG FOR THE
CWA THROUGH FRIDAY.
CONTINUAL OVERRUNNING AND THE SLOW EASTWARD TRANSLATION OF THE UPPER
LEVEL LOW WILL KEEP POP CHANCES HIGH FOR THE NORTH AND EAST ZONES
THROUGHOUT THE NEXT 24 HOURS. ELEVATED LAPSE RATES CONTINUED TO BE
STEEP AND WITH MORNING CONVECTION TODAY RESULTING IN SOME
LIGHTNING STRIKES...LEFT ISO T MENTION IN THE WX GRID THROUGH FRIDAY.
EVEN THOUGH RAIN WILL BE IN THE FORECAST THROUGH SATURDAY
MORNING...QPF VALUES SHOULD STAY BELOW CONCERNABLE VALUES DUE TO
THE FACT THE RAIN SHOULD STAY LIGHT. CURRENTLY...THE TOTAL QPF
FORECAST BETWEEN TONIGHT AND SATURDAY IS LESS THAN AN INCH ACROSS
THE CWA.
LONG TERM (SATURDAY THROUGH THURSDAY)...
THE UPPER LEVEL SYSTEM WILL FINALLY CLEAR OUT OF THE AREA SATURDAY
FROM THE WEST TO THE EAST. LATER IN THE EVENING...A STRONG BUT DRY
CP AIR MASS WILL DIVE SOUTH OUT OF THE PANHANDLE BRINGING GUSTY
WINDS SUNDAY DUE TO A RAPIDLY TIGHTENING PRESSURE GRADIENT...AND A
VERY COLD MORNING ON MONDAY. GUIDANCE IS CURRENTLY SUGGESTING
TEMPERATURES IN THE LOWER 20S IN THE NORTH AND AROUND 30 IN OUR
SOUTHERNMOST LOCATIONS SO IF THE FORECAST HOLDS...THE REMAINING
COUNTIES THAT HAVE NOT REACHED A WIDESPREAD FREEZE WILL DO SO COME
MONDAY.
THIS COOL PATTERN OF COLD MORNINGS AND COOL DAYS WILL PERSIST
THROUGH THE EXTENDED. A UPPER LEVEL RIDGE WILL MOVE OVER THE ROCKY
MOUNTAINS BY THURSDAY WHILE A WEAK DISTURBANCE FROM BAJA CREEPS
INTO THE SOUTHWEST. THIS MAY BRING SHOWER ACTIVITY BACK INTO THE
FORECAST TOWARDS THE END OF THE WEEK. MORE TO COME ON THIS AS
LATER MODEL RUNS PROVIDE MORE CLARITY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 37 42 40 59 36 / 80 90 90 20 10
AUSTIN BERGSTROM INTL AIRPORT 38 44 39 60 36 / 80 80 90 20 10
NEW BRAUNFELS MUNI AIRPORT 39 45 40 63 37 / 70 80 90 20 10
BURNET MUNI AIRPORT 35 40 35 57 32 / 80 80 90 20 10
DEL RIO INTL AIRPORT 37 49 40 63 37 / 60 60 60 - 0
GEORGETOWN MUNI AIRPORT 36 42 38 58 34 / 80 90 90 20 10
HONDO MUNI AIRPORT 38 47 39 63 35 / 60 70 70 10 10
SAN MARCOS MUNI AIRPORT 38 44 39 61 36 / 70 80 90 20 10
LA GRANGE - FAYETTE REGIONAL 41 47 44 60 38 / 80 80 90 40 10
SAN ANTONIO INTL AIRPORT 39 46 41 62 36 / 70 80 90 20 10
STINSON MUNI AIRPORT 40 46 40 63 37 / 70 70 80 20 10
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...17
SYNOPTIC/GRIDS...15
PUBLIC SERVICE/DATA COLLECTION...33
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
316 PM CST WED DEC 31 2014
.DISCUSSION...
CHALLENGING FORECAST TODAY AS THE INFLUENCE OF A COMPLEX WESTERN
U.S. TROUGH AFFECTS MUCH OF TEXAS BEGINNING TONIGHT. WITH ARCTIC
AIR IN PLACE ACROSS THE REGION...FREEZING AND FROZEN PRECIPITATION
WILL BE A SIGNIFICANT THREAT TONIGHT AND THURSDAY MORNING...
ESPECIALLY ALONG AND WEST OF INTERSTATE 35.
WE WILL CONTINUE WITH THE WINTER STORM WARNING FOR 8 COUNTIES IN
THE WESTERN SECTIONS OF NORTH TEXAS WHERE UP TO ONE QUARTER INCH
OF FREEZING RAIN MAY FALL TONIGHT AND EARLY THURSDAY. TEMPERATURES
IN THE WARNING AREA ARE FORECAST TO BE IN THE MID TO UPPER 20S
DURING THE ONSET OF HEAVIER BANDED PRECIPITATION AFTER MIDNIGHT
TONIGHT. PROGRESSIVELY LESSER IMPACTS ARE EXPECTED FURTHER EAST
FROM THE WARNING AREA...WITH TEMPERATURES NEAR OR JUST BELOW
FREEZING FORECAST DURING THE PRECIPITATION. THE EXACT IMPACTS IN
ANY GIVEN LOCATION IN THE ADVISORY AND WARNING AREAS THROUGH EARLY
THURSDAY WILL BE DETERMINED BY TEMPERATURES DURING THE ONSET OF
HEAVIER PRECIPITATION AND THE LOCATION OF ANY SLEET SHOWERS THAT
SPREAD EASTWARD OVERNIGHT.
WITH REGARD TO THE KEY WEATHER FEATURES...THE STRONG UPPER TROUGH
CURRENTLY DEVELOPING INTO WESTERN ARIZONA WILL EJECT INTO THE
PLAINS WITH TWO DISTINCTIVE WAVES. THE FIRST WAVE OF ENERGY IS
FORECAST TO MOVE ACROSS NORTHERN NEW MEXICO AND EASTERN COLORADO
ON THURSDAY AND WILL BE RESPONSIBLE FOR THE WINTER WEATHER EVENT
TONIGHT. PLENTIFUL PACIFIC MOISTURE...STRONG LOW LEVEL WARM AIR
ADVECTION...AND SOME MID LEVEL FRONTOGENESIS WILL LEAD TO THE
DEVELOPMENT OF WIDESPREAD PRECIPITATION FROM WEST TO EAST AFTER
MIDNIGHT. SOME CONVECTIVE BANDS /SHOWERS/ ARE FORECAST TO DEVELOP
IN THE AXIS OF FRONTOGENESIS TONIGHT WHICH IS FORECAST TO BE
CENTERED FROM THE EASTLAND AND BRECKENRIDGE AREAS EASTWARD INTO
THE DFW METROPLEX AFTER MIDNIGHT. WINTER WEATHER IMPACTS WILL BE
ENHANCED LOCALLY NEAR ANY OF THE HEAVIER SLEET SHOWERS THAT
DEVELOP IN AREAS WITH SURFACE TEMPERATURES NEAR OR BELOW FREEZING.
EXPECT PRECIPITATION TO CONTINUE IN MOST AREAS DURING FOR MUCH OF
THE DAY THURSDAY AND WILL GRADUALLY TRANSITION TO ALL LIQUID RAIN
DURING THE AFTERNOON HOURS AS TEMPERATURES SLOWLY RISE TO ABOVE
FREEZING. THE NUMERICAL MODEL GUIDANCE SUGGESTS THAT THE
MODIFICATION OF THE ARCTIC AIRMASS MAY BE ACCELERATED IN TWO WAYS.
FIRST...THE RELATIVELY WARM RAINDROPS FALLING THROUGH THE
INCREASINGLY WARM AIR ABOVE THE FRONTAL INVERSION WILL EFFECTIVELY
TRANSFER HEAT TO THE NEAR SURFACE AIR. SECOND...THE RELEASE OF
LATENT HEATING BY THE PRECIPITATION PRODUCTION PROCESS IN THE
ABSENCE OF LOW LEVEL COLD ADVECTION COULD ALSO RESULT IN SLOWLY
RISING TEMPERATURES. BY LATE THURSDAY AFTERNOON...EXPECT
TEMPERATURES TO BE AT 32 OR HIGHER IN ALL AREAS...WITH THE COLDEST
TEMPERATURES IN THE FAR NORTHWEST ZONES.
THERE MAY BE A BRIEF 6-12 HOUR LULL IN THE RAIN THURSDAY EVENING
AND THURSDAY NIGHT AS THE FIRST WAVE OF ENERGY FROM THE SOUTHWEST
U.S. SYSTEM MOVES ACROSS KANSAS THURSDAY NIGHT. HOWEVER...THE
PRIMARY SHORTWAVE / SECOND WAVE OF ENERGY / IS FORECAST TO EJECT
EASTWARD INTO NEW MEXICO AND WEST TEXAS BY LATE FRIDAY. WIDESPREAD
RAIN WILL REDEVELOP IN ALL AREAS BY LATE THURSDAY NIGHT OR EARLY
FRIDAY AND CONTINUE INTO FRIDAY NIGHT. THE RAINS AND ISOLATED
THUNDERSTORMS WILL END FROM WEST TO EAST ON SATURDAY AFTERNOON AS
THE SHORTWAVE EJECTS QUICKLY ACROSS OKLAHOMA.
A THIRD SYSTEM WILL MOVE ACROSS THE AREA ON SUNDAY...BUT THIS
SYSTEM SHOULD BE WEAKER AND LACK SIGNIFICANT MOISTURE TO PRODUCE
PRECIPITATION. WILL KEEP THE FORECAST FOR SUNDAY INTO THE MIDDLE
OF NEXT WEEK DRY...WITH TEMPERATURES CONTINUING TO AVERAGE BELOW
NORMAL.
09/GP
&&
.AVIATION...
/ISSUED 1212 PM CST WED DEC 31 2014/
/18Z TAF ISSUANCE/
PRIMARY CONCERN WITH THIS TAF ISSUANCE IS THE OCCURRENCE...TIMING
AND LOCATION OF FREEZING RAIN AT THE METROPLEX AIRPORT SITES THROUGH
THURSDAY MORNING. BY 12Z THURS...THERE WILL BE A ROUGH DEMARCATION
ACROSS THE DFW METROPLEX BETWEEN SITES THAT RECEIVE NO ICING AT
ALL...AND THOSE THAT HAVE VARYING DEGREES OF ICE IMPACT ON PAVED
AREAS AND ELEVATED SURFACES. WACO TAF SITE WILL ALSO BE ON THE
BORDERLINE AS FAR AS IMPACTS...BUT PROBABLY STAY LIQUID.
ARCTIC AIRMASS WILL REMAIN IN PLACE ACROSS NORTH TEXAS THROUGH
FRIDAY. WHILE SURFACE TEMPERATURES AT ALL SITES ARE NOW RUNNING IN
THE MID 30S...BELIEVE THESE READINGS WILL SLIP BACK TOWARD
FREEZING BEGINNING THIS EVENING...AIDED BY SOME WEAK COLD
ADVECTION AND PRECIPITATION-INDUCED COOLING. SPOTTY LIGHT RAIN
WILL LIKELY BEGIN ACROSS NORTH TEXAS AFTER 02Z THIS
EVENING...BECOMING MORE WIDESPREAD AFTER 06Z AND CONTINUING
THROUGH AT LEAST 21Z THURSDAY. ONSET AT WACO WILL BE DELAYED
SOMEWHAT...BUT EXPECT CATEGORICAL RAIN THERE BY 08Z.
BASED ON LATEST HRRR AND NAM MODELS...CURRENT THINKING IS THAT
SUB-FREEZING AIR TEMPS WILL EXIST FOR SEVERAL HOURS IN THE WESTERN
PORTIONS OF THE DFW METROPLEX AFTER 08Z...CREATING SOME ICE IMPACTS
AT KAFW AND KFTW THRU AT LEAST 15Z. KDFW...KDAL AND KGKY WILL BE
BORDERLINE...BUT BELIEVE THERE WILL BE A PERIOD AFTER 09Z WHEN
-FZRA WILL OCCUR...AT LEAST ON ELEVATED SURFACES. NOT CONFIDENT
ENOUGH OF ANY SUSTAINED FREEZING PRECIPITATION AT WACO TO MENTION
IN TAF AT PRESENT. RAINFALL WILL PICK UP IN INTENSITY AFTER
12Z...AND EXPECT A SLIGHT REBOUND IN TEMPERATURES TO LOWER/MIDDLE
30S AFTER THAT TIME. ANY ICE THAT DOES DEVELOP AT METROPLEX TAF
SITES SHOULD DISSIPATE DUE TO COMBINATION OF HEAVIER RAIN AND
SLIGHTLY WARMER AIR AND PRECIPITATION TEMPERATURES.
BRADSHAW
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 30 36 36 41 40 / 60 80 70 80 70
WACO, TX 32 38 38 42 39 / 70 80 80 80 70
PARIS, TX 32 37 36 42 40 / 40 90 80 80 80
DENTON, TX 27 35 35 40 38 / 60 80 70 80 70
MCKINNEY, TX 27 35 35 41 39 / 50 80 70 80 70
DALLAS, TX 31 37 37 41 40 / 60 80 70 80 70
TERRELL, TX 33 37 37 41 40 / 50 80 80 80 70
CORSICANA, TX 34 39 39 42 41 / 60 80 80 80 80
TEMPLE, TX 32 38 38 41 39 / 70 80 80 80 70
MINERAL WELLS, TX 26 33 33 39 36 / 70 80 70 80 70
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 3 PM CST THURSDAY FOR TXZ100-101-115-
116-129-130-141-142.
WINTER WEATHER ADVISORY UNTIL 3 PM CST THURSDAY FOR TXZ091>094-
102>104-117>120-131>134-143>145-156>159.
&&
$$
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
1212 PM CST WED DEC 31 2014
.AVIATION...
/18Z TAF ISSUANCE/
PRIMARY CONCERN WITH THIS TAF ISSUANCE IS THE OCCURRENCE...TIMING
AND LOCATION OF FREEZING RAIN AT THE METROPLEX AIRPORT SITES THROUGH
THURSDAY MORNING. BY 12Z THURS...THERE WILL BE A ROUGH DEMARCATION
ACROSS THE DFW METROPLEX BETWEEN SITES THAT RECEIVE NO ICING AT
ALL...AND THOSE THAT HAVE VARYING DEGREES OF ICE IMPACT ON PAVED
AREAS AND ELEVATED SURFACES. WACO TAF SITE WILL ALSO BE ON THE
BORDERLINE AS FAR AS IMPACTS...BUT PROBABLY STAY LIQUID.
ARCTIC AIRMASS WILL REMAIN IN PLACE ACROSS NORTH TEXAS THROUGH
FRIDAY. WHILE SURFACE TEMPERATURES AT ALL SITES ARE NOW RUNNING IN
THE MID 30S...BELIEVE THESE READINGS WILL SLIP BACK TOWARD
FREEZING BEGINNING THIS EVENING...AIDED BY SOME WEAK COLD
ADVECTION AND PRECIPITATION-INDUCED COOLING. SPOTTY LIGHT RAIN
WILL LIKELY BEGIN ACROSS NORTH TEXAS AFTER 02Z THIS
EVENING...BECOMING MORE WIDESPREAD AFTER 06Z AND CONTINUING
THROUGH AT LEAST 21Z THURSDAY. ONSET AT WACO WILL BE DELAYED
SOMEWHAT...BUT EXPECT CATEGORICAL RAIN THERE BY 08Z.
BASED ON LATEST HRRR AND NAM MODELS...CURRENT THINKING IS THAT
SUB-FREEZING AIR TEMPS WILL EXIST FOR SEVERAL HOURS IN THE WESTERN
PORTIONS OF THE DFW METROPLEX AFTER 08Z...CREATING SOME ICE IMPACTS
AT KAFW AND KFTW THRU AT LEAST 15Z. KDFW...KDAL AND KGKY WILL BE
BORDERLINE...BUT BELIEVE THERE WILL BE A PERIOD AFTER 09Z WHEN
-FZRA WILL OCCUR...AT LEAST ON ELEVATED SURFACES. NOT CONFIDENT
ENOUGH OF ANY SUSTAINED FREEZING PRECIPITATION AT WACO TO MENTION
IN TAF AT PRESENT. RAINFALL WILL PICK UP IN INTENSITY AFTER
12Z...AND EXPECT A SLIGHT REBOUND IN TEMPERATURES TO LOWER/MIDDLE
30S AFTER THAT TIME. ANY ICE THAT DOES DEVELOP AT METROPLEX TAF
SITES SHOULD DISSIPATE DUE TO COMBINATION OF HEAVIER RAIN AND
SLIGHTLY WARMER AIR AND PRECIPITATION TEMPERATURES.
BRADSHAW
&&
.UPDATE...
...WINTER WEATHER ADVISORY EXPANDED EASTWARD TO INCLUDE DALLAS AND WACO...
CURRENT OBSERVED TRENDS AND UPDATED MODEL GUIDANCE CONTINUE TO
COME IN COLDER THAN PREVIOUSLY EXPECTED...SO HAVE NUDGED DAYTIME
HIGHS AND OVERNIGHT LOWS DOWN A FEW DEGREES FOR THE NEXT 24 HOURS.
THE UPPER LEVEL DISTURBANCE THAT WILL PROVIDE THE NECESSARY LIFT
FOR PRECIPITATION TONIGHT AND TOMORROW FOR NORTH AND CENTRAL TEXAS IS
CENTERED OVER SOUTHERN CALIFORNIA/WESTERN ARIZONA AS OF 9 AM.
MODEL GUIDANCE APPEARS TO BE IN GOOD AGREEMENT THAT THIS ENERGY
WILL AFFECT THE REGION AS EARLY AS TONIGHT. AS A RESULT OF THE
TEMPERATURE TRENDS AND UPPER LEVEL SUPPORT EXPECTED TO BE IN PLACE...A
LARGER AREA OF NORTH AND CENTRAL TEXAS IS EXPECTED TO RECEIVE A
MIXED BAG OF WINTER PRECIPITATION THROUGH MIDDAY TOMORROW. THIS
TEMPERATURE TREND WARRANTED THE EASTWARD EXPANSION OF THE WINTER
WEATHER ADVISORY AS WELL.
AJS
&&
.PREV DISCUSSION... /ISSUED 420 AM CST WED DEC 31 2014/
LIGHT BANDS OF FREEZING DRIZZLE...FREEZING RAIN...SLEET AND EVEN
SOME LIGHT SNOW SET UP OVERNIGHT ACROSS THE NORTH/NORTHWEST
COUNTIES OF NORTH TEXAS. SOME LIGHT ACCUMULATIONS OF MAINLY SNOW WERE
REPORTED ACROSS PORTIONS OF JACK COUNTY AND WISE COUNTY. MOIST
ISENTROPIC LIFT OVER THE ARCTIC AIR MASS WAS RESPONSIBLE FOR THE
PRECIP. THE FREEZING DRIZZLE AND SLEET WAS EXPECTED BUT WAS A BIT
SURPRISED TO SEE THE LITTLE BANDS OF SNOW SINCE THE DENDRITIC
GROWTH ZONE WAS NO WHERE NEAR SATURATED. MODELS INDICATE THAT THE
ISENTROPIC LIFT WILL WEAKEN IN THE NORTHWEST ZONES THROUGH SUNRISE
SO PRECIP SHOULD CONTINUE TO WEAKEN/DISSIPATE.
MODELS ARE IN FAIRLY GOOD AGREEMENT THAT ISENTROPIC LIFT WILL BE ON
THE INCREASE ACROSS THE SOUTHWEST ZONES OF NORTH TEXAS DURING THE
DAY TODAY AND WE WOULD NOT BE SURPRISED TO SEE MORE MIXED WINTER
PRECIPITATION DEVELOP BEFORE SUNSET.
LARGE SCALE UPWARD FORCING WILL BE ON THE INCREASE TONIGHT AS THE
STRONG UPPER LOW CURRENTLY OVER SOUTHERN CALIFORNIA MOVES EAST
ACROSS ARIZONA. ALTHOUGH THE BEST LIFT WILL STILL REMAIN WEST OF
THE REGION UNTIL THE UPPER LOW GETS CLOSER...ALL 00Z MODEL RUNS
INDICATE THAT A PIECE OF ENERGY WILL ROUND THE BASE OF THE UPPER
LOW AND MOVE EAST NORTHEAST ACROSS THE REGION. FOR THIS REASON WE
HAVE DECIDED TO EXPAND THE ADVISORY THAT IS CURRENTLY IN EFFECT TO
INCLUDE ONE MORE ROW OF COUNTIES TO THE EAST AND ALSO GRAYSON...FANNIN
AND COLLIN COUNTIES. WE HAVE ALSO CHANGED THE FREEZING RAIN ADVISORY TO A
WINTER WEATHER ADVISORY SINCE THE PRECIP TONIGHT MAY BE MORE OF A
MIX OF FREEZING RAIN AND SLEET. IT DOES APPEAR THAT FREEZING RAIN
WILL BECOME THE DOMINANT WEATHER TYPE AFTER SUNRISE THURSDAY ONCE
THE WARM LAYER ABOVE THE ARCTIC AIR DEEPENS. OUR PRIMARY CONCERN
IS THAT THE NORTHWEST ZONES WHICH ARE CURRENTLY IN THE MIDDLE 20S
WILL NOT WARM UP MUCH TODAY AND THAT THERE WILL BE A PERIOD OF
FAIRLY SIGNIFICANT ICE AND SOME SLEET THURSDAY MORNING. FOR THIS
REASON WE HAVE DECIDED TO UPGRADE THE CURRENT ADVISORY TO A WINTER
STORM WARNING. THE WARNING AREA WILL INCLUDE LOCATIONS ALONG AND
WEST OF A LINE FROM JACKSBORO TO STEPHENVILLE TO GOLDTHWAITE.
ACCUMULATIONS OF ICE AND SLEET IN THE REGION COULD TOTAL ONE
QUARTER INCH. AM GROWING MORE CONCERNED THAT ALL MODELS ARE
TRENDING WETTER AND COLDER SO FUTURE UPGRADES AND ADJUSTMENTS ARE
VERY POSSIBLE.
PRECIPITATION SHOULD TRANSITION INTO A COLD RAIN FOR NEARLY ALL OF
NORTH TEXAS THURSDAY AFTERNOON. SOME FREEZING RAIN MAY HOLD ON IN
THE NORTHWEST ZONES BUT SURFACE TEMPS SHOULD WARM CLOSER TO
FREEZING. RAIN WILL CONTINUE ACROSS ALL OF NORTH TEXAS THURSDAY
NIGHT THROUGH FRIDAY AS THE UPPER LOW APPROACHES. FOR NOW WE HAVE
KEPT ALL TEMPS THURSDAY NIGHT THROUGH FRIDAY NIGHT ABOVE FREEZING
WITH ONLY RAIN EXPECTED BUT WE WILL HAVE TO WATCH THE THURSDAY
NIGHT TIME PERIOD AS A FEW SPOTS MAY BE VERY CLOSE TO FREEZING.
RAIN CHANCES WILL END FROM WEST TO EAST SATURDAY AS THE UPPER LOW
MOVES NORTHEAST INTO THE CENTRAL PLAINS.
SATURDAY NIGHT THROUGH TUESDAY WILL BE DRY WITH NORTHWEST FLOW
ALOFT AND LIMITED SURFACE MOISTURE.
79
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 37 30 40 35 40 / 10 50 70 70 70
WACO, TX 40 31 40 36 42 / 20 40 80 70 70
PARIS, TX 38 30 37 34 42 / 10 20 80 80 70
DENTON, TX 35 29 37 33 40 / 10 50 70 60 70
MCKINNEY, TX 38 29 38 33 39 / 10 20 80 70 70
DALLAS, TX 38 32 42 36 41 / 10 40 80 70 70
TERRELL, TX 41 33 38 36 40 / 10 20 80 70 70
CORSICANA, TX 41 32 39 37 41 / 10 30 80 70 70
TEMPLE, TX 41 33 40 36 41 / 20 40 70 70 70
MINERAL WELLS, TX 32 28 37 33 38 / 20 50 70 60 70
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 3 PM CST THURSDAY FOR TXZ100-101-115-
116-129-130-141-142.
WINTER WEATHER ADVISORY UNTIL 3 PM CST THURSDAY FOR TXZ091>094-
102>104-117>120-131>134-143>145-156>159.
&&
$$
66/
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
944 PM MST THU JAN 1 2015
.UPDATE...
ISSUED AT 609 PM MST THU JAN 1 2015
THE WINTER STORM WARNING FOR THE CORTEZ AREA WAS ALLOWED TO
EXPIRE. OCCASIONAL SNOWFALL WILL CONTINUE BUT ADDITIONAL
ACCUMULATE SHOULD BE LESS THAN 2 INCHES.
&&
.SHORT TERM...(TONIGHT THROUGH FRIDAY NIGHT)
ISSUED AT 320 PM MST THU JAN 1 2015
THE HEAVIEST SNOWFALL OCCURRED LATE LAST NIGHT AND EARLY THIS
MORNING ACROSS THE FOUR CORNERS REGION AS PREDICTED. REPORTS
INDICATED 3 TO 5 INCHES OF SNOWFALL ACROSS MUCH OF THE REGION
WITH SNOWFALL RATES NEAR 1 INCH PER HOUR IN SOME LOCATIONS. UPWARD
FORCING IMPRESSIVE DURING THIS PERIOD AHEAD OF MID-LEVEL LOW
CENTERED OVER NORTH-CENTRAL ARIZONA. AT 12Z...GOOD SURFACE
CONVERGENCE IN EVIDENCE WITH SURFACE LOW CENTERED SOUTH OF KDRO
ACCORDING TO RAP ANALYSIS. CONCURRENTLY...STRONG MID-LEVEL QG
ASCENT OVER THE AREA TOPPED BY DIVERGENCE AT HIGHER LEVELS OF THE
TROPOSPHERE WHERE LEFT EXIT REGION OF JET WAS POSITIONED.
HOWEVER...DURING THE AFTERNOON COVERAGE AND SNOWFALL RATES HAD
DECREASED SIGNIFICANTLY AS FORCING WAS DIMINISHED. SOUTHWESTWARD
FLOWING JET ON THE BACK SIDE OF THE LOW CONTINUED TO PROPAGATE TO
THE SOUTHWEST WHILE THE NORTHEASTWARD FLOWING JET ON THE LEADING
EDGE MOVED OVER THE SOUTHERN PLAINS. THE SHEARING MOMENT BETWEEN
THESE FLOWS STRETCHED THE LOW ALONG A SOUTHWEST TO NORTHEAST AXIS.
AS A RESULT...DYNAMIC FORCING SHIFTED TO THE NORTHEAST CAUSING THE
SURFACE AND 7H LOW CIRCULATIONS TO MOVE IN THAT DIRECTION. IN
ADDITION TO THE LOSS OF DYNAMIC FORCING OVER THE SOUTHERN FORECAST
AREA...OROGRAPHIC LIFT ALSO IMPACTED AS WEAK 7H LOW RECENTERED
OVER THE SAN JUANS RESULTING IN WEAK AND VARIED WINDS.
MODELS IN GOOD AGREEMENT...GENERATING VERY LITTLE QPF OVER MOST OF
THE LOWER ELEVATIONS OF SOUTHEAST UTAH AND SOUTHWEST COLORADO
DURING THE REMAINDER OF THE AFTERNOON AND THIS EVENING. THEREFORE
...WILL CANCEL WINTER STORM WARNINGS FOR THESE AREAS WITH THIS
PACKAGE. HOWEVER...RAP13 AND HRRR BOTH INDICATED MODERATE SNOWFALL
WILL CONTINUE ALONG A SOUTHWEST TO NORTHEAST ORIENTED BAND
CENTERED OVER KCEZ. CONSEQUENTLY...WILL HOLD ONTO WINTER STORM
WARNING FOR MODERATE SNOWFALL OVER THE SOUTHWEST CORNER OF THE
STATE. IN ADDITION...LIGHT TO MODERATE SNOW SHOULD CONTINUE OVER
THE SAN JUAN MOUNTAINS WHILE COVERAGE INCREASES OVER THE CENTRAL
COLORADO MOUNTAINS AS DYNAMIC FORCING BECOMES MORE FAVORABLE. ONLY
EXPECTING 2 TO 4 INCHES WITH LOCALLY HIGHER AMOUNTS IN THE CENTRAL
MOUNTAINS SO WILL NOT EXPAND WINTER WEATHER ADVISORIES...THOUGH
WILL CONTINUE HILITES ACROSS THE SAN JUANS INTO THE EVENING.
SUBSIDENCE AND DRYING SETS IN LATER TONIGHT AS THE LOW CENTER IS
DRIVEN SOUTHWARD BY THE SOUTHWESTWARD PROPAGATING JET ON THE LOW/S
REAR FLANK. AS A RESULT...SNOWFALL WILL DIMINISH TO A FEW
FLURRIES OVER THE CENTRAL MOUNTAINS AFTER MIDNIGHT. ANTICYCLONIC
FLOW TO THE NORTH WILL INHIBIT SNOWFALL FRIDAY...THOUGH CANNOT
ENTIRELY RULE OUT A FEW FLURRIES ALONG THE DIVIDE FRIDAY
AFTERNOON. A SHORTWAVE TROUGH DROPPING TOWARD THE REGION FROM THE
NORTHWEST WILL BE THE NEXT SNOW PRODUCER OVER THE FORECAST AREA
POSSIBLY IMPACTING THE NORTHERN COLORADO MOUNTAINS FRIDAY NIGHT.
THE AREA WILL BE UNDER WARM AIR ADVECTION WHILE FLOW REMAINS
ANTICYCLONIC SO EXPECT SNOW WILL BE SCATTERED AND LIGHT...LIKELY
HOLDING OFF UNTIL AFTER MIDNIGHT AS INDICATED BY FAVORED GFS AND
ECMWF SOLUTIONS.
WAA WILL ALLOW AIRMASS TO MODERATE A BIT...BUT TEMPERATURES WILL
REMAIN COLDER THAN NORMAL FOR THE LATTER PART OF THE WEEK.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 320 PM MST THU JAN 1 2015
EXPECT SNOW WILL INCREASE OVER THE NORTHERN COLORADO MOUNTAINS
SATURDAY AS THE SHORTWAVE TROUGH DISCUSSED PREVIOUSLY PUSHES
ACROSS SOUTHWEST WYOMING IN THE MORNING...THEN ACROSS NORTHWEST
COLORADO DURING THE AFTERNOON. MODELS NOT GENERATING SIGNIFICANT
SNOW ACCUMULATIONS AT THIS POINT...BUT THERE REMAINS THE POTENTIAL
FOR ADVISORY LEVEL SNOW ACROSS THE PARK...GORE...ELKHEAD...AND
FLATTOP RANGES. A TIGHTENING GRADIENT ALOFT BENEATH THE NOSE OF A
SOUTHWARD FLOWING 120 KT JET WILL GENERATE STRONG AND GUSTY
NORTHWEST WINDS ACROSS THE RIDGES GENERATING AREAS OF BLOWING
SNOW.
MODELS INDICATED ANOTHER SHORTWAVE IN THE NORTHWESTERLIES WILL
BRING SIMILAR CONDITIONS SUNDAY AFTERNOON THROUGH SUNDAY NIGHT...
THOUGH IT APPEARS TO BE WEAKER THAN SATURDAY/S SYSTEM. HOWEVER...
ECMWF INDICATED THAT OROGRAPHIC SNOWFALL COULD CONTINUE WELL INTO
MONDAY SO MAY BE MORE IMPACTFUL THAN DEPICTED NOW. A RIDGE OF HIGH
PRESSURE EASES EASTWARD FROM TUESDAY TO THURSDAY BRINGING DRY AND
MILDER CONDITIONS FOR THE MIDDLE PART OF THE COMING WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 945 PM MST THU JAN 1 2015
MVFR TO IFR CONDITIONS STILL IN PLACE ACROSS SEVERAL FORECAST
TERMINAL SITES IN SOUTHWEST COLORADO AS WEAK LIFT AND MOISTURE
CONTINUE TO WRAP WESTWARD INTO THE REGION. MODELS TREND CONTINUE
TO SUGGEST IMPROVEMENT THROUGH 02/09Z AS THIS SYSTEM SPLITS AND
LEAVES OUR CWA VOID OF UPPER SUPPORT. WITH RECENT PRECIPITATION
ALWAYS A CHANCE OF STRATUS AND FOG DEVELOPING SUCH AS THE CASE AT
DRO THIS EVENING. WILL CONTINUE TO MONITOR LOW CLOUD/FOG SATELLITE
IMAGERY AND TRY AND DEFINE BEST PERIODS WHEN LOWERED FLIGHT
CRITERIA WILL BE PREVAILING. WITH LACK OF UPPER SUPPORT AND DRYING
ALOFT TOMORROW MAINLY DRY CONDITIONS ARE EXPECTED. DENDRITIC
LAYERS STAY UNSATURATED THROUGH THE EVENING LEAVING ONLY LIGHT
OROGRAPHIC SHOWERS AS A THREAT AN IMPACTS TO FORECAST TERMINALS
APPEAR REMOTE ATTM.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER WEATHER ADVISORY UNTIL MIDNIGHT MST TONIGHT FOR COZ018.
WINTER STORM WARNING UNTIL MIDNIGHT MST TONIGHT FOR COZ019.
UT...WINTER STORM WARNING UNTIL MIDNIGHT MST TONIGHT FOR UTZ028.
&&
$$
UPDATE...CC
SHORT TERM...NL
LONG TERM...NL
AVIATION...TGJT
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
352 AM EST FRI JAN 2 2015
.UPDATE...
THE SYNOPSIS...NEAR TERM...SHORT TERM
AND LONG TERM SECTIONS HAVE BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 348 AM EST FRI JAN 2 2015
A LOW PRESSURE SYSTEM APPROACHING FROM THE PLAINS WILL BRING A
CHANCE FOR SOME LIGHT FREEZING RAIN AND RAIN TO THE AREA TONIGHT AND
MODERATE TO HEAVY RAIN AT TIMES ON SATURDAY. COULD SEE A CHANCE FOR
SNOW ON SUNDAY AS THE SYSTEM MOVES OUT AND COLDER AIR ARRIVES. A
CLIPPER SYSTEM WILL BRING LIGHT SNOW CHANCES MONDAY NIGHT THROUGH
TUESDAY AND COLDER AIR WILL SETTLE IN OVER THE AREA.
&&
.NEAR TERM /THIS MORNING AND TODAY/...
ISSUED AT 348 AM EST FRI JAN 2 2015
RADAR LOOP AND OBSERVATIONS ARE SHOWING SOME LIGHT SNOW AND RAIN
ACROSS SOUTHERN PORTIONS OF CENTRAL INDIANA. HRRR AND RAP SHOW THESE
LIGHT SHOWERS CONTINUING OFF AND ON THROUGH AROUND 12-15Z SO ADDED
SOME LOW CHANCE POPS INTO THE SOUTH TO COVER THESE FOR THE NEXT FEW
HOURS. COULD SEE SOME VERY LIGHT SLEET AS WELL IN THIS WINTRY
MIX...AND THIS COMBINATION COULD CAUSE SOME SLICK SPOTS ON UNTREATED
ROADS IN SOUTHERN PARTS OF CENTRAL INDIANA EARLY THIS MORNING.
AFTER THE AFOREMENTIONED SHOWERS MOVE OFF TO THE EAST SHOULD SEE DRY
CONDITIONS ACROSS THE AREA FOR THE REST OF THE DAY. CLOUDS WILL
CONTINUE TO STREAM IN FROM THE SOUTH OVERRUNNING THE WARM FRONT AND
THIS SHOULD KEEP TEMPERATURES FROM RISING TOO SIGNIFICANTLY TODAY.
SHOULD SEE HIGHS MAINLY IN THE 30S.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 348 AM EST FRI JAN 2 2015
FORECAST FOCUS IS ON PRECIP TIMING WITH WEEKEND SYSTEM AS WELL AS
PRECIP TYPE. MODELS ARE IN FAIRLY GOOD AGREEMENT AND WILL USE A
CONSENSUS APPROACH FOR THE MOST PART.
TO BEGIN THE TONIGHT PERIOD LOOKS LIKE A WARM FRONT WILL BE
APPROACHING FROM THE SOUTH AS A LOW PRESSURE SYSTEM PREPARES TO
TRAVEL THROUGH THE OHIO VALLEY FROM THE PLAINS. PRECIPITATION WILL
MOVE IN FROM THE SOUTHWEST. THIS SET OF MODEL RUNS IS FASTER WITH
THE APPROACH OF THE SYSTEM SO TRENDED THAT WAY AND BROUGHT IN POPS
AFTER 3Z. THICKNESSES AND SOUNDINGS INDICATE THE POTENTIAL FOR
FREEZING RAIN FOR A PERIOD AT ONSET...BUT THE WARM ADVECTION LOOKS
STOUT AND MODELS ARE ALL PROGGING SURFACE TEMPERATURES TO START
RISING BETWEEN 3 AND 9Z. WITH SURFACE TEMPERATURES POSSIBLY WARMING
ABOVE FREEZING DURING THE OVERNIGHT INCLUDED CHANCES FOR FREEZING
RAIN ALONG WITH THE RAIN BUT ELIMINATED THE FREEZING RAIN FROM SOUTH
TO NORTH STILL DURING THE TONIGHT PERIOD BASED ON HOURLY SURFACE
TEMPERATURES SURPASSING FREEZING. STILL MAINTAINED A CHANCE FOR
FREEZING RAIN IN THE NORTHERN COUNTIES FROM 12-15Z SATURDAY IN CASE
SURFACE TEMPERATURES DO NOT RISE AS QUICKLY AS ANTICIPATED.
SATURDAY STRONG ISENTROPIC LIFT ALONG WITH UPPER FORCING AND FORCING
FROM THE APPROACH AND PASSAGE OF THE SURFACE LOW WILL BRING RAIN TO
THE ENTIRE AREA. A STRONG LOW LEVEL JET WILL BRING AMPLE MOISTURE
UP AHEAD OF THE SYSTEM AND COULD SEE RAINFALL TOTALS IN EXCESS OF
1.5-2 INCHES IN SOME PLACES. RAIN SHOULD CONTINUE INTO SATURDAY
NIGHT AND COULD SEE SOME SNOW MIX IN LATE IN THE NORTHWEST.
UPPER SHORTWAVE WILL MOVE THROUGH THE AREA ON SUNDAY. ALTHOUGH THE
ATMOSPHERE SHOULD BE PRETTY DRY...WITH THE WAVE MOVING THROUGH ALONG
WITH MUCH COLDER AIR COMING INTO PLACE THING SEEING SOME SNOW IS NOT
OUT OF THE QUESTION. THUS WENT WITH CONSENSUS LOW CHANCE POPS IN THE
NORTHWEST CLOSER TO THE TRACK OF THE SHORTWAVE TAPERING TO SLIGHT
CHANCE IN THE SOUTHWEST. COLUMN SHOULD BE COOL ENOUGH FOR ANY PRECIP
SUNDAY TO FALL AS SNOW. BY SUNDAY NIGHT THE UPPER WAVE WILL BE
THROUGH AND SHOULD SEE DRY CONDITIONS. COLD ADVECTION ON DECENT
NORTHWESTERLY WINDS SHOULD ALLOW TEMPERATURES TO DROP BUT THE MIXING
FROM THE WIND SHOULD KEEP THEM FROM BOTTOMING OUT. THUS ACCEPTED THE
SLIGHTLY WARMER CONSENSUS NUMBERS WITH SINGLE DIGITS NORTHWEST TO
MID TEENS SOUTHEAST.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
ISSUED AT 348 AM EST FRI JAN 2 2015
APPEARS THE MAJORITY OF THE EXTENDED PERIOD WILL BE DRY...SAVE FOR
ONE QUICK CLIPPER SYSTEM SET TO IMPACT THE AREA MONDAY NIGHT THROUGH
TUESDAY. ANYWHERE FROM HALF AN INCH TO UPWARDS OF NEAR AN INCH OF
SNOW IS POSSIBLE AT THIS TIME...SO ACCUMULATIONS LOOK LIGHT AT THIS
TIME.
THE OTHER BIGGER STORY DURING THIS TIME IS POTENTIALLY THE
COLDEST AIR OF THE SEASON BEARING DOWN ON THE REGION AFTER THAT
CLIPPER SYSTEM EXITS THE REGION. BY TUESDAY NIGHT ALREADY LOOKING AT
SINGLE DIGIT TEMPS...SAME FOR WEDNESDAY NIGHT. THESE VERY COLD TEMPS
COMBINED WITH STRONG SURFACE N/NW FLOW WILL CREATE WIND CHILLS THAT
MAY APPROACH WIND CHILL ADVISORY CRITERIA AT TIMES TUESDAY NIGHT
THROUGH THURSDAY.
&&
.AVIATION /DISCUSSION FOR THE 020600Z TAF ISSUANCE/...
ISSUED AT 318 AM EST FRI JAN 2 2015
0815Z UPDATE...NO CHANGES NEEDED AT THIS TIME. PREVIOUS DISCUSSION
FOLLOWS.
VFR EXPECTED AT LEAST THROUGH THE BULK OF THE DAY TOMORROW. AFTER
20Z AT HUF AND BMG AND 00Z SATURDAY AT IND...COULD SEE CONDITIONS
DETERIORATE TO MVFR OR WORSE AS CU EXPANDS NORTHWARD ACROSS THE
TERMINALS IN SOUTHERLY FLOW AHEAD OF A SOUTHERN SYSTEM.
WINDS SHOULD BE SOUTHWEST LESS THAN 10 KNOTS UNTIL AFTER 18Z WHEN
WINDS WILL BACK TO SOUTH AND THEN SOUTHEAST.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...CP
SHORT TERM...CP
LONG TERM....SMF
AVIATION...SMF/KOCH
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
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AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
357 AM EST FRI JAN 2 2015
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 340 AM EST FRI JAN 2 2015
08Z SFC ANALYSIS SHOWS HIGH PRESSURE FADING OVER EASTERN KENTUCKY IN
ADVANCE OF A DEVELOPING WX SYSTEM TO THE SOUTHWEST AND AN AREA OF LOW
PRESSURE OFF TO THE NORTHEAST. THE CLOUDS ASSOCIATED WITH THE
SOUTHWEST SYSTEM HAVE OVERSPREAD THE AREA WITH POCKETS OF LIGHT PCPN
SHOWING UP ON THE REGIONAL RADAR...MAINLY SOUTH OF THE STATE
BORDER...THOUGH SOME RETURNS HAVE DEVELOPED ALONG INTERSTATE 64 IN
CENTRAL KENTUCKY...IN LINE WITH THE LATEST HRRR. THROUGH EAST
KENTUCKY TEMPERATURES ARE FAIRLY UNIFORM IN THE MID 30S WHILE
DEWPOINTS ARE GENERALLY IN THE MID 20S. DEW POINT DEPRESSIONS ON THE
ORDER OF 10 DEGREES WILL LEAD TO A CONCERN FOR WETBULBING WITH ANY
EARLY PCPN THIS MORNING THAT SHOULD RESULT IN PATCHES OF SLEET ALONG
WITH THE LIGHT RAIN. WILL CONTINUE TO DEPICT THIS IN THE GRIDS AND
MENTION IT IN THE HWO AND ZONES...THOUGH ANY IMPACTS ARE EXPECTED TO
BE MINIMAL GIVEN PAVEMENT TEMPERATURES ABOVE FREEZING THROUGH THE
EASTERN PARTS OF THE STATE. WINDS REMAIN LIGHT FROM THE SOUTHWEST
THROUGH THE AREA EARLY THIS MORNING.
THE MODELS ARE IN GOOD AGREEMENT ALOFT FOR THE SHORT TERM PORTION OF
THE FORECAST AS THEY ALL SHOW THE SOUTHWESTERN CLOSED LOW GETTING
PARTIALLY PICKED UP BY THE NORTHERN STREAM LATER TODAY. THIS PROCESS
RELEASES A BATCH OF ENERGY AND LOWER HEIGHTS INTO THE CENTRAL PLAINS
BY EVENING WHILE A LARGER PORTION STAYS SEPARATE OVER SOUTHERN NEW
MEXICO. THE EXPELLED NORTHERN WAVE IS QUICKLY ABSORBED INTO THE
LARGER FLOW AND SPREAD OVER THE CENTRAL GREAT LAKES BY MIDDAY
SATURDAY WHILE THE MAIN LOW IS KICKED EAST BY SOME ENERGY RIDING INTO
ITS BACKSIDE LATER SATURDAY. AHEAD OF THESE WAVES...BROAD SOUTHWEST
FLOW WILL SEND WARMER AND MORE MOIST AIR INTO THE TENNESSEE AND OHIO
VALLEYS TODAY THROUGH SATURDAY. GIVEN THE MODEL AGREEMENT HAVE
FOLLOWED THE HIGHER RESOLUTION NAM12 AND HRRR MOST CLOSELY.
SENSIBLE WEATHER WILL FEATURE THE NET RESULT OF A MOISTENING
ENVIRONMENT AND A DEVELOPING SFC LOW TO THE SOUTHWEST...RAIN CHANCES
MOVING IN FROM SOUTHWEST TO NORTHEAST TODAY. THE BETTER CHANCES
ARRIVE AFTER 18Z FOR THE BULK OF THE JKL CWA ALLOWING THE WARMER AIR
TO BRING UP TEMPERATURES WHILE DEWPOINTS CLIMB ABOVE FREEZING MAKING
ALL THE PCPN LIQUID AFTER THE EARLY MORNING POCKETS OF LIGHT MIXED
PCPN. THE REAL SURGE OF SHOWERS WILL ARRIVE LATER TONIGHT AS A
DEVELOPING WARM FRONT LIFTS INTO THE AREA AND PROVIDES A GOOD
FOCUSING MECHANISM FOR THE INCREASINGLY MOIST AIR. BY DAWN SATURDAY
THE DEEPENING SFC LOW OVER THE LOWER MISSISSIPPI VALLEY WILL LIFT ITS
WARM FRONT NORTH OF THE AREA PLACING OUR AREA IN THE WARM SECTOR OF A
RAPIDLY DEVELOPING SYSTEM TO THE WEST. AS A RESULT...WINDS WILL
INCREASE STEADILY DURING THE DAY SATURDAY WITH ENOUGH INSTABILITY
AVAILABLE FOR A RISK OF THUNDER ACROSS THE ENTIRE AREA...POSSIBLY
ARRIVING BEFORE DAWN SATURDAY PER THE LATEST SWODY1. A BREEZY AND
MILD DAY ENSUES AHEAD OF THE SYSTEM/S COLD FRONT LATER SATURDAY WITH
DRY WEATHER EXPECTED FOR A GOOD PORTION OF THE TIME...THOUGH SOME
SCATTERED SHOWERS AND POSSIBLE THUNDERSTORMS WILL BE AROUND EASTERN
KENTUCKY INTO SATURDAY EVENING. WILL HIT THE THUNDER CHANCES AND THE
BREEZY CONDITIONS HARDER IN THE HWO TO BE ISSUED LATER THIS MORNING.
USED THE BCCONSSHORT AS A STARTING POINT FOR TEMPS...TD...AND WINDS
THROUGH 21Z FRIDAY AND THEN THE SUPERBLEND THROUGH 00Z SUNDAY. ONLY
SLIGHTLY TWEAKED POINT TEMPERATURE DATA FOR MAXES AND MINS. AS FOR
POPS...FAVORED A BLEND OF THE HRRR AND NAM12 EARLY THEN MAINLY THE
NAM12 THROUGH TONIGHT AND SATURDAY. ON THE WHOLE...ENDED UP SIMILAR
TO THE MOS BLEND WITH POPS THROUGH THE SHORT TERM...BUT DETAILS WHERE
ADDED TO SHOW SOME BREAKS WITHIN THE WARM SECTOR DRY SLOTTING
EXPECTED ON SATURDAY.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 357 AM EST FRI JAN 2 2015
THE EXTENDED FORECAST PERIOD BEGINS ON SATURDAY NIGHT WITH AN
AMPLIFIED UPPER LEVEL PATTERN OVER THE CONUS. A LARGE LONGWAVE
TROUGH MOVES THROUGH THE CENTRAL PAINS AND INTO THE MS RIVER VALLEY.
AT THIS TIME A POTENT SHORT WAVE IS LIFTING OUT OF THE MID MS RIVER
VALLEY AND MOVING INTO THE OH VALLEY...WHILE A SECOND STRONG
SHORTWAVE DEVELOPS ALONG THE LOWER PORTION OF THE MS VALLEY AND
QUICK LIFTS NORTHEAST AS WELL INTO THE LOWER APPALACHIAN RANGE. A
STRONG JET DEVELOPING IN THE UPPER LEVELS ON SUNDAY NIGHT OVER THE
MID ATLANTIC WILL LIFT THE UPPER LEVEL TROUGH NORTHEAST INTO THE NEW
ENGLAND AREA. THIS SETS THE PATTERN FROM MONDAY THROUGH THURSDAY OF
A SEMI PERMANENT UPPER LEVEL LONGWAVE TROUGH OVER THE GREAT LAKES
AND NEW ENGLAND AREA. THIS CYCLONIC FLOW OVER THE NORTHEASTERN CONUS
WILL LEAD TO NORTHWEST FLOW FOR EASTERN KENTUCKY THROUGH THE REST OF
THE EXTENDED.
CLOSER TO THE SURFACE FOR THE FRONT MOVING THROUGH SAT NIGHT THROUGH
SUNDAY NIGHT...THE INHERITED FORECAST AND RESULT OF THE BLEND OF
MODELS LEAVES QUITE A BIT OF PRECIP MOVING THROUGH SAT NIGHT THROUGH
SUNDAY. PWATS DURING THIS TIME WITH MODEL SOUNDINGS SHOW 1.34 INCHES
WHICH IS AMPLE THIS TIME OF YEAR. HPC RESULTS ALONG WITH THE MODEL
BLEND PUT AROUND AN INCH IN THE AREA FOR THE STA NIGHT AND SUNDAY
TIME FRAME AND HAVE GONE WITH THESE VALUES AS THOUGH...WEAKENING THE
SHOWERS WITH THE FRONT MOVING THROUGH COULD PRODUCE SOME DECENT
RAINFALL AT TIMES. AS MENTIONED WITH THE LOW SHOWING A WEAKENING
TREND...THERE IS A DECENT AMOUNT OF ISENTROPIC LIFT AHEAD AND WITH
THIS FRONT AND WITH THE INHERITED FORECAST COUPLED WITH A CONSENSUS
OF NEIGHBORING OFFICES...DECIDED TO KEEP A SLIGHT CHANCE OF THUNDER
IN THE SATURDAY NIGHT PORTION. AS MENTIONED WITH THE PROGRESSIVE
FLOW AND QUICK EXIT OF THIS FEATURE...PRECIP HANGING UP ON THE
EASTERN RIDGES SHOULD BE SHORT IN DURATION AND HAVE ALL POPS
EXITING EARLY SUNDAY NIGHT. AS SUCH...THE MOISTURE WILL EXIT THE
AREA BEFORE ANY COLD AIR FILTERS IN. ANY CHANGE OVER TO SNOW ACROSS
THE AREA IS NOT EXPECTED.
THE DRIER NORTHWEST FLOW SETTING UP BY TUESDAY WILL HINDER PRECIP
MAKING IT FAR ENOUGH SOUTH INTO EASTERN KENTUCKY FOR SNOWFALL. BASED
ON INHERITED FORECAST...PATTERN RECOGNITION AND COLLABORATION WITH
THE NEIGHBORING OFFICES...HAVE GONE DRY WITH THE WEAK SHORTWAVE
MOVING THROUGH THE OH VALLEY TUESDAY NIGHT INTO WEDNESDAY. WHILE A
FEW FLURRIES ARE POSSIBLE AS WELL...THE GENERAL TREND WITH THIS IS
THAT AS MOISTURE STARVED AS THESE CLIPPER SYSTEMS ARE...THE BULK OF
THE UPPER LEVEL SUPPORT STAYS TO THE NORTH WITH THIS WAVE. AFTER
SUNDAY NIGHT...HAVE GONE DRY OVER EASTERN KENTUCKY FOR THE REST OF
THE FORECAST. THE DEW POINTS WITH THIS ARCTIC AIR MASS MOVING IN
DURING THE LAST PART OF THE EXTENDED IS QUITE IMPRESSIVE. QUITE A
COLD AND DRY AIR MASS MAKES ITS PRESENCE KNOWN DIVING SOUTH INTO THE
CENTRAL CONUS AND MEANDERING SOUTHEAST BY THE END OF THE EXTENDED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 100 AM EST FRI JAN 2 2015
CLOUDS WILL GRADUALLY LOWER THROUGH THE NIGHT...WITH LIGHT
PRECIPITATION THREATENING TOWARD DAWN MAINLY ALONG AND SOUTH OF THE
HAL ROGERS PARKWAY. THIS WILL FALL AS MOSTLY LIGHT RAIN...HOWEVER
SOME SLEET IS ALSO POSSIBLE AT ONSET. EXPECT MVFR CLOUDS TO MOVE
OVER THE SOUTH BETWEEN 09 AND 12Z...AND THEN GRADUALLY OVERTAKE MORE
OF THE AREA FROM SOUTH TO NORTHWARD THROUGH THE DAY FRIDAY...WITH
LOCATIONS ALONG AND NORTH OF THE I-64 CORRIDOR LIKELY STAYING VFR
UNTIL LATER FRIDAY AFTERNOON WHEN A DEVELOPING WARM FRONT LIFT INTO
THE AREA FROM THE SOUTH. SOUTHWEST WINDS OF 5 TO 10 KTS CAN BE
EXPECTED THROUGH THE REST OF THE NIGHT AND INTO THE DAY FRIDAY.
HOWEVER...LOCATIONS ALONG THE I-64 CORRIDOR WILL LIKELY MAINTAIN
SPEEDS 10 KTS BEFORE DIMINISHING TOWARDS DAWN.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GREIF
LONG TERM...SHALLENBERGER
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
120 AM EST FRI JAN 2 2015
.UPDATE...
ISSUED AT 120 AM EST FRI JAN 2 2015
THE CURRENT FORECAST IS ON TRACK FROM THE LAST UPDATED WITH THE HRRR
AND 00Z NAM12 KEEPING THE CWA PRETTY MUCH DRY THROUGH THE REST OF
THE NIGHT. HAVE JUST FINE TUNED TEMPS AND DEW POINTS PER THE LATEST
OBS...TRENDS...AND CONSSHORT GUIDANCE. THESE UPDATES HAVE BEEN SENT
TO THE NDFD AND WEB SERVERS.
UPDATE ISSUED AT 1116 PM EST THU JAN 1 2015
TEMPERATURES HAVE BEEN WARMING IN MOST OF THE VALLEY LOCATIONS THIS
EVENING...AS CLOUDS AND SOUTHWEST TO WEST SOUTHWEST WINDS HAVE BEEN
KEEPING THINGS MIXED...MORE TYPICAL OF THE DAYTIME BOUNDARY LAYER
PROCESS. PRECIPITATION CHANCES ARE TRENDING DRIER IN THE MODELS
THROUGH FRIDAY MORNING. HAVE REDUCED POPS BACK TO SLIGHT CHANCE
WITHIN THE CUMBERLAND VALLEY. GIVEN THE DRIER AIR IN PLACE...WILL
STILL ALLOW FOR A SLIGHT CHANCE OF SLEET...HOWEVER DO NOT EXPECT THIS
TO BE MUCH OF AN IMPACT AS IT WILL BE VERY LIGHT...AND GROUND
TEMPERATURES SHOULD REMAIN ABOVE FREEZING. UPDATES HAVE BEEN SENT.
UPDATE ISSUED AT 731 PM EST THU JAN 1 2015
MOISTURE IS ON ITS WAY IN AS EVIDENT BY THE LIGHT RADAR RETURNS
CURRENTLY SHOWING UP ACROSS WESTERN TN/KY. TEMPERATURES ACROSS THE
SOUTHERN PORTION ARE RANGING FROM 36 TO 41 DEGREES...WITH DEW POINTS
RUNNING FROM THE MID TEENS TO THE MID 20S. THE CURRENT SHORT RANGE
MODELS CONTINUE TO SUPPORT SOME LIGHT PRECIP SKIMMING THE KY/TN
BORDER THROUGH THE OVERNIGHT...FALLING AS LIGHT RAIN/SLEET/FREEZING
RAIN DEPENDING ON HOW QUICKLY THE COLUMN SATURATES. INITIALLY...THE
DEW POINTS WILL MOST LIKELY COME UP FASTER THAN THE TEMPERATURE DROPS
OFF. THIS MAY KEEP THE FREEZING RAIN POTENTIAL LOWER SINCE GROUND
TEMPERATURES ARE GENERALLY IN THE UPPER 30S. FURTHER NORTH...SKIES
HAVE PARTIALLY CLEARED THROUGH EARLY THIS EVENING...WITH A FEW
VALLEYS ALREADY CLOSE IF NOT DROPPING BELOW FORECAST LOWS. WILL ALLOW
FROM SOME MID 20S IN THE SHELTERED VALLEYS IN THE NORTHEAST...WHERE
THICKER CLOUDS WILL LIKELY HOLD OFF FOR ANOTHER FEW HOURS. THE MODELS
CONTINUE TO SHOW A LITTLE SURGE OF PRECIP COMING IN FROM NORTH
CENTRAL KENTUCKY TOWARDS DAWN. THIS APPEARS TO BE ASSOCIATED WITH A
SMALL POCKET OF UPPER LEVEL DIVERGENCE. THE HRRR SHOWS ONLY WEAK
RETURNS MAKING IT IN TO OUR NORTH TOWARDS DAWN...AND ANYTHING THAT
DOES MAKE IT TO THE GROUND WOULD LIKELY BE IN THE FORM OF SLEET BASED
ON THE FORECAST SOUNDINGS. WILL MAINTAIN THE DRY FORECAST FOR THE
NORTH FOR NOW AND REASSESS ONCE THE 00Z DATA COMES IN. UPDATES WILL
BE FORTHCOMING.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 348 PM EST THU JAN 1 2015
HIGH PRESSURE WILL GIVE WAY TO AN ADVANCING STORM SYSTEM OVER THE
NEXT 36 HOURS. A WARM FRONT WILL PASS THROUGH OUR REGION FRIDAY
NIGHT BRINGING STRONG RAIN CHANCES. BEFORE THAT HAPPENS...WEAK
OVERRUNNING WILL CAUSE CLOUDS TO ADVANCE BACK TO THE NORTH TONIGHT
AND THEN LOWER DURING THE DAY FRIDAY AS THE AIR MASS MOISTENS FROM
THE TOP DOWN. FORECAST MODELS CONTINUE TO INDICATE THE POSSIBILITY
OF SOME LIGHT PRECIP BREAKING OUT LATE TONIGHT INTO EARLY FRIDAY
MORNING. BEST CHANCES FOR THAT HAPPENING ARE ALONG THE TENNESSEE
BORDER...BUT SOME SPOTTY PRECIP MAY SNEAK NORTHWARD EARLY SATURDAY
MORNING. WILL ADVERTISE A MIX OF LIGHT RAIN AND SLEET WITH SOME
SPOTTY FREEZING RAIN WHERE FORECAST TEMPS FLIRT WITH FREEZING...
ALTHOUGH PROBABILITY OF OCCURRENCE OF ANY PRECIP IS LOW (GENERALLY
ONLY 20 TO 30 PERCENT). RAIN CHANCES RAMP UP FRIDAY AFTERNOON AND
FRIDAY NIGHT AFTER SURFACE TEMPS WARM WELL ABOVE FREEZING ENDING ANY
THREAT FOR WINTRY PRECIP. DECIDED TO REMOVE ANY MENTION OF FREEZING
RAIN FROM THE FORECAST NORTH OF I-64 LATE FRIDAY NIGHT FIGURING
SURFACE TEMPS WILL HAVE A HARD TIME FALLING BACK TOWARD FREEZING
WITH SOUTHERLY FLOW/WARM ADVECTION IN PLACE.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 348 PM EST THU JAN 1 2015
MODELS ARE STILL IN DECENT AGREEMENT STARTING OUT THE EXTENDED
PORTION OF THE FORECAST. BY SATURDAY MORNING...MODELS ARE CONTINUING
TO DEPICT PARTIAL PHASING OF THE NORTHERN AND SOUTHERN STREAMS OVER
NORTH AMERICA. A CLOSED LOW WHICH IS EXPECTED TO BE IN NEW MEXICO
AND NORTHERN TX WILL BE THE MAIN FOCUS OF CONCERN AS WE START OUT
THE FORECAST. THIS LOW WILL SHIFT NEWARD AND LOSE CONSIDERABLE
STRENGTH AS IT MOVES JUST N OF THE OHIO RIVER VALLEY THROUGH SUNDAY
MORNING. AFTER IT PASSES...MUCH OF THE CENTRAL CONUS WILL BE LEFT IN
A GENERAL TROUGHING PATTERN...WITH MUCH OF KY IN A STRONG PRESSURE
GRADIENT ON THE LEEWARD SIDE OF THE TROUGH AT 12Z SUNDAY WITH SW
FLOW. AS THE THROUGH SHIFTS EASTWARD...HEIGHTS WILL RAPIDLY DECREASE
ACROSS KY THROUGH SUNDAY EVENING...THOUGH THE TROUGH ITSELF DOES
SHOW SIGNS OF BROADENING OUT. MODELS ARE SURPRISINGLY STILL IN GOOD
AGREEMENT AS THE AXIS OF THIS TROUGH PASSES OVER KY SUNDAY NIGHT AND
MONDAY...BEFORE HEIGHTS FINALLY START RISING AGAIN ON THE BACK END
MONDAY NIGHT AND ON. IT APPEARS AS THOUGH THE LOW RESPONSIBLE FOR
THIS TROUGH /OVER NE CANADA/ WILL SLOW ITS PROPAGATION...SO THE RISE
IN HEIGHTS WILL BE MUCH SLOWER AND CONTINUE THROUGH THE REMAINDER OF
THE EXTENDED...COMPARED TO HOW QUICKLY THEY DECREASED AS THE TROUGH
NEARED KY.
A SURFACE LOW WILL PROCEED THE CLOSED LOW THAT IS EXPECTED TO MOVE
JUST NORTH OF KY. MODELS CONTINUE TO DEPICT DECENT OVERRUNNING AS
THE SURFACE LOW GRAZES THE WESTERN PORTION OF KY ON ITS TRACK NEWARD
DURING THE DAY SATURDAY. THIS OVERRUNNING...IN ADDITION TO A GOOD
SOUTHERLY FLOW OF MOISTURE FROM THE GULF OF MEXICO...WILL LEAD TO
WIDESPREAD MODERATE PRECIP ACROSS THE REGION. KY WILL ORIGINALLY
FIND ITSELF IN THE WARM SECTOR OF THIS SYSTEM AT 12Z SATURDAY...WITH
SW FLOW BRINGING IN WARMER TEMPS IN THE LOW...MID AND UPPER LEVELS.
THIS STILL SUPPORTS AN IMPRESSIVE WARM NOSE DEVELOPING...SUGGESTING
THAT MOST OF THE PRECIP WILL FALL AS RAIN. TEMPERATURES WERE RAISED
A DEGREE OR TWO IN THE NORTH...SO REMOVED ANY MENTION OF FREEZING
RAIN OR SNOW FOR 12Z SATURDAY. GIVEN HOW FAST THE SYSTEM IS TRACKING
ACROSS KY...AND THE RAPID DECREASE IN HEIGHTS ALOFT...IN ADDITION TO
WARMER TEMPS AND STRONG SW FLOW...WILL CONTINUE WITH MENTION OF
POSSIBLE THUNDERSTORMS SATURDAY AFTERNOON AND NIGHT...MAINLY DURING
THE HEAVIEST RAIN. BY SUNDAY MORNING...THE SURFACE SYSTEM WILL HAVE
PASSED EAST OF THE REGION...WHILE LOSING CONSIDERABLE STRENGTH
ALOFT. THE TROUGHING PATTERN OVER THE CONUS...HOWEVER...WILL LEAVE
SW FLOW IN PLACE...SO WILL KEEP WITH CHANCES OF RAIN SATURDAY NIGHT
AND DURING THE DAY SUNDAY.
WINDS AT THIS POINT WILL THEN SWITCH TO A MORE WRLY DIRECTION IN THE
MID AND UPPER LEVELS...WITH MUCH DRIER AIR USHERING IN. CONTINUED
LOW LEVEL WRAP AROUND MOISTURE IS STILL POSSIBLE THROUGH SUNDAY
EVENING...BUT WILL QUICKLY TAPER OFF. UPSLOPE FLOW WILL KEEP POPS IN
SLIGHTLY LONGER ACROSS THE HIGHER TERRAIN IN THE SE. THIS WILL BE
THE POINT WHEN THE UPPER LEVEL TROUGH AXIS IS MOVING ACROSS AND JUST
EAST OF THE REGION...WITH MUCH COLDER AIR USHERING INTO THE REGION.
AS A RESULT...PREVIOUS FORECAST HAD LINGERING RAIN CHANGING OVER TO
SNOW SUNDAY EVENING. HOWEVER...IT SEEMS AS THOUGH MODELS ARE
TRENDING THE POPS OUT SLIGHTLY FASTER NOW...SO EXPECT THAT BELOW
FREEZING TEMPS WON/T PLAY MUCH OF A CONCERN SINCE PRECIP WILL BE OUT
OF THE AREA BEFORE IT TAKES AFFECT. KEPT ANY PRECIP SUNDAY EVENING
AS RAIN BEFORE TAPERING OFF.
RISING HEIGHTS AND SURFACE HIGH PRESSURE SHOULD KEEP MOST OF THE
CONCERN FOR FURTHER PRECIP OUT OF THE REGION THROUGH MIDWEEK WHILE
TEMPERATURES STAY WELL BELOW NORMAL. SEVERAL SHORTWAVES WILL LIKELY
QUICKLY PASS ALONG THE LONGWAVE TROUGH AXIS...BRINGING THE THREAT OF
SHORT LIVED SHOTS OF PRECIP THROUGH THE LAST PART OF THE FORECAST.
THE FIRST OF THESE WILL BE TUESDAY NIGHT...WITH SOME POSSIBILITY
THAT THE PRECIP COULD GRAZE OUR FAR NORTHERN COUNTIES IN THE FORM OF
A QUICK LIGHT SNOW. ANOTHER ONE MAY IMPACT THE REGION WEDNESDAY
NIGHT INTO THURSDAY AS WELL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 100 AM EST FRI JAN 2 2015
CLOUDS WILL GRADUALLY LOWER THROUGH THE NIGHT...WITH LIGHT
PRECIPITATION THREATENING TOWARD DAWN MAINLY ALONG AND SOUTH OF THE
HAL ROGERS PARKWAY. THIS WILL FALL AS MOSTLY LIGHT RAIN...HOWEVER
SOME SLEET IS ALSO POSSIBLE AT ONSET. EXPECT MVFR CLOUDS TO MOVE
OVER THE SOUTH BETWEEN 09 AND 12Z...AND THEN GRADUALLY OVERTAKE MORE
OF THE AREA FROM SOUTH TO NORTHWARD THROUGH THE DAY FRIDAY...WITH
LOCATIONS ALONG AND NORTH OF THE I-64 CORRIDOR LIKELY STAYING VFR
UNTIL LATER FRIDAY AFTERNOON WHEN A DEVELOPING WARM FRONT LIFT INTO
THE AREA FROM THE SOUTH. SOUTHWEST WINDS OF 5 TO 10 KTS CAN BE
EXPECTED THROUGH THE REST OF THE NIGHT AND INTO THE DAY FRIDAY.
HOWEVER...LOCATIONS ALONG THE I-64 CORRIDOR WILL LIKELY MAINTAIN
SPEEDS 10 KTS BEFORE DIMINISHING TOWARDS DAWN.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...ABE
LONG TERM...JMW
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1116 PM EST THU JAN 1 2015
.UPDATE...
ISSUED AT 1116 PM EST THU JAN 1 2015
TEMPERATURES HAVE BEEN WARMING IN MOST OF THE VALLEY LOCATIONS THIS
EVENING...AS CLOUDS AND SOUTHWEST TO WEST SOUTHWEST WINDS HAVE BEEN
KEEPING THINGS MIXED...MORE TYPICAL OF THE DAYTIME BOUNDARY LAYER
PROCESS. PRECIPITATION CHANCES ARE TRENDING DRIER IN THE MODELS
THROUGH FRIDAY MORNING. HAVE REDUCED POPS BACK TO SLIGHT CHANCE
WITHIN THE CUMBERLAND VALLEY. GIVEN THE DRIER AIR IN PLACE...WILL
STILL ALLOW FOR A SLIGHT CHANCE OF SLEET...HOWEVER DO NOT EXPECT THIS
TO BE MUCH OF AN IMPACT AS IT WILL BE VERY LIGHT...AND GROUND
TEMPERATURES SHOULD REMAIN ABOVE FREEZING. UPDATES HAVE BEEN SENT.
UPDATE ISSUED AT 731 PM EST THU JAN 1 2015
MOISTURE IS ON ITS WAY IN AS EVIDENT BY THE LIGHT RADAR RETURNS
CURRENTLY SHOWING UP ACROSS WESTERN TN/KY. TEMPERATURES ACROSS THE
SOUTHERN PORTION ARE RANGING FROM 36 TO 41 DEGREES...WITH DEW POINTS
RUNNING FROM THE MID TEENS TO THE MID 20S. THE CURRENT SHORT RANGE
MODELS CONTINUE TO SUPPORT SOME LIGHT PRECIP SKIMMING THE KY/TN
BORDER THROUGH THE OVERNIGHT...FALLING AS LIGHT RAIN/SLEET/FREEZING
RAIN DEPENDING ON HOW QUICKLY THE COLUMN SATURATES. INITIALLY...THE
DEW POINTS WILL MOST LIKELY COME UP FASTER THAN THE TEMPERATURE DROPS
OFF. THIS MAY KEEP THE FREEZING RAIN POTENTIAL LOWER SINCE GROUND
TEMPERATURES ARE GENERALLY IN THE UPPER 30S. FURTHER NORTH...SKIES
HAVE PARTIALLY CLEARED THROUGH EARLY THIS EVENING...WITH A FEW
VALLEYS ALREADY CLOSE IF NOT DROPPING BELOW FORECAST LOWS. WILL ALLOW
FROM SOME MID 20S IN THE SHELTERED VALLEYS IN THE NORTHEAST...WHERE
THICKER CLOUDS WILL LIKELY HOLD OFF FOR ANOTHER FEW HOURS. THE MODELS
CONTINUE TO SHOW A LITTLE SURGE OF PRECIP COMING IN FROM NORTH
CENTRAL KENTUCKY TOWARDS DAWN. THIS APPEARS TO BE ASSOCIATED WITH A
SMALL POCKET OF UPPER LEVEL DIVERGENCE. THE HRRR SHOWS ONLY WEAK
RETURNS MAKING IT IN TO OUR NORTH TOWARDS DAWN...AND ANYTHING THAT
DOES MAKE IT TO THE GROUND WOULD LIKELY BE IN THE FORM OF SLEET BASED
ON THE FORECAST SOUNDINGS. WILL MAINTAIN THE DRY FORECAST FOR THE
NORTH FOR NOW AND REASSESS ONCE THE 00Z DATA COMES IN. UPDATES WILL
BE FORTHCOMING.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 348 PM EST THU JAN 1 2015
HIGH PRESSURE WILL GIVE WAY TO AN ADVANCING STORM SYSTEM OVER THE
NEXT 36 HOURS. A WARM FRONT WILL PASS THROUGH OUR REGION FRIDAY
NIGHT BRINGING STRONG RAIN CHANCES. BEFORE THAT HAPPENS...WEAK
OVERRUNNING WILL CAUSE CLOUDS TO ADVANCE BACK TO THE NORTH TONIGHT
AND THEN LOWER DURING THE DAY FRIDAY AS THE AIR MASS MOISTENS FROM
THE TOP DOWN. FORECAST MODELS CONTINUE TO INDICATE THE POSSIBILITY
OF SOME LIGHT PRECIP BREAKING OUT LATE TONIGHT INTO EARLY FRIDAY
MORNING. BEST CHANCES FOR THAT HAPPENING ARE ALONG THE TENNESSEE
BORDER...BUT SOME SPOTTY PRECIP MAY SNEAK NORTHWARD EARLY SATURDAY
MORNING. WILL ADVERTISE A MIX OF LIGHT RAIN AND SLEET WITH SOME
SPOTTY FREEZING RAIN WHERE FORECAST TEMPS FLIRT WITH FREEZING...
ALTHOUGH PROBABILITY OF OCCURRENCE OF ANY PRECIP IS LOW (GENERALLY
ONLY 20 TO 30 PERCENT). RAIN CHANCES RAMP UP FRIDAY AFTERNOON AND
FRIDAY NIGHT AFTER SURFACE TEMPS WARM WELL ABOVE FREEZING ENDING ANY
THREAT FOR WINTRY PRECIP. DECIDED TO REMOVE ANY MENTION OF FREEZING
RAIN FROM THE FORECAST NORTH OF I-64 LATE FRIDAY NIGHT FIGURING
SURFACE TEMPS WILL HAVE A HARD TIME FALLING BACK TOWARD FREEZING
WITH SOUTHERLY FLOW/WARM ADVECTION IN PLACE.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 348 PM EST THU JAN 1 2015
MODELS ARE STILL IN DECENT AGREEMENT STARTING OUT THE EXTENDED
PORTION OF THE FORECAST. BY SATURDAY MORNING...MODELS ARE CONTINUING
TO DEPICT PARTIAL PHASING OF THE NORTHERN AND SOUTHERN STREAMS OVER
NORTH AMERICA. A CLOSED LOW WHICH IS EXPECTED TO BE IN NEW MEXICO
AND NORTHERN TX WILL BE THE MAIN FOCUS OF CONCERN AS WE START OUT
THE FORECAST. THIS LOW WILL SHIFT NEWARD AND LOSE CONSIDERABLE
STRENGTH AS IT MOVES JUST N OF THE OHIO RIVER VALLEY THROUGH SUNDAY
MORNING. AFTER IT PASSES...MUCH OF THE CENTRAL CONUS WILL BE LEFT IN
A GENERAL TROUGHING PATTERN...WITH MUCH OF KY IN A STRONG PRESSURE
GRADIENT ON THE LEEWARD SIDE OF THE TROUGH AT 12Z SUNDAY WITH SW
FLOW. AS THE THROUGH SHIFTS EASTWARD...HEIGHTS WILL RAPIDLY DECREASE
ACROSS KY THROUGH SUNDAY EVENING...THOUGH THE TROUGH ITSELF DOES
SHOW SIGNS OF BROADENING OUT. MODELS ARE SURPRISINGLY STILL IN GOOD
AGREEMENT AS THE AXIS OF THIS TROUGH PASSES OVER KY SUNDAY NIGHT AND
MONDAY...BEFORE HEIGHTS FINALLY START RISING AGAIN ON THE BACK END
MONDAY NIGHT AND ON. IT APPEARS AS THOUGH THE LOW RESPONSIBLE FOR
THIS TROUGH /OVER NE CANADA/ WILL SLOW ITS PROPAGATION...SO THE RISE
IN HEIGHTS WILL BE MUCH SLOWER AND CONTINUE THROUGH THE REMAINDER OF
THE EXTENDED...COMPARED TO HOW QUICKLY THEY DECREASED AS THE TROUGH
NEARED KY.
A SURFACE LOW WILL PROCEED THE CLOSED LOW THAT IS EXPECTED TO MOVE
JUST NORTH OF KY. MODELS CONTINUE TO DEPICT DECENT OVERRUNNING AS
THE SURFACE LOW GRAZES THE WESTERN PORTION OF KY ON ITS TRACK NEWARD
DURING THE DAY SATURDAY. THIS OVERRUNNING...IN ADDITION TO A GOOD
SOUTHERLY FLOW OF MOISTURE FROM THE GULF OF MEXICO...WILL LEAD TO
WIDESPREAD MODERATE PRECIP ACROSS THE REGION. KY WILL ORIGINALLY
FIND ITSELF IN THE WARM SECTOR OF THIS SYSTEM AT 12Z SATURDAY...WITH
SW FLOW BRINGING IN WARMER TEMPS IN THE LOW...MID AND UPPER LEVELS.
THIS STILL SUPPORTS AN IMPRESSIVE WARM NOSE DEVELOPING...SUGGESTING
THAT MOST OF THE PRECIP WILL FALL AS RAIN. TEMPERATURES WERE RAISED
A DEGREE OR TWO IN THE NORTH...SO REMOVED ANY MENTION OF FREEZING
RAIN OR SNOW FOR 12Z SATURDAY. GIVEN HOW FAST THE SYSTEM IS TRACKING
ACROSS KY...AND THE RAPID DECREASE IN HEIGHTS ALOFT...IN ADDITION TO
WARMER TEMPS AND STRONG SW FLOW...WILL CONTINUE WITH MENTION OF
POSSIBLE THUNDERSTORMS SATURDAY AFTERNOON AND NIGHT...MAINLY DURING
THE HEAVIEST RAIN. BY SUNDAY MORNING...THE SURFACE SYSTEM WILL HAVE
PASSED EAST OF THE REGION...WHILE LOSING CONSIDERABLE STRENGTH
ALOFT. THE TROUGHING PATTERN OVER THE CONUS...HOWEVER...WILL LEAVE
SW FLOW IN PLACE...SO WILL KEEP WITH CHANCES OF RAIN SATURDAY NIGHT
AND DURING THE DAY SUNDAY.
WINDS AT THIS POINT WILL THEN SWITCH TO A MORE WRLY DIRECTION IN THE
MID AND UPPER LEVELS...WITH MUCH DRIER AIR USHERING IN. CONTINUED
LOW LEVEL WRAP AROUND MOISTURE IS STILL POSSIBLE THROUGH SUNDAY
EVENING...BUT WILL QUICKLY TAPER OFF. UPSLOPE FLOW WILL KEEP POPS IN
SLIGHTLY LONGER ACROSS THE HIGHER TERRAIN IN THE SE. THIS WILL BE
THE POINT WHEN THE UPPER LEVEL TROUGH AXIS IS MOVING ACROSS AND JUST
EAST OF THE REGION...WITH MUCH COLDER AIR USHERING INTO THE REGION.
AS A RESULT...PREVIOUS FORECAST HAD LINGERING RAIN CHANGING OVER TO
SNOW SUNDAY EVENING. HOWEVER...IT SEEMS AS THOUGH MODELS ARE
TRENDING THE POPS OUT SLIGHTLY FASTER NOW...SO EXPECT THAT BELOW
FREEZING TEMPS WON/T PLAY MUCH OF A CONCERN SINCE PRECIP WILL BE OUT
OF THE AREA BEFORE IT TAKES AFFECT. KEPT ANY PRECIP SUNDAY EVENING
AS RAIN BEFORE TAPERING OFF.
RISING HEIGHTS AND SURFACE HIGH PRESSURE SHOULD KEEP MOST OF THE
CONCERN FOR FURTHER PRECIP OUT OF THE REGION THROUGH MIDWEEK WHILE
TEMPERATURES STAY WELL BELOW NORMAL. SEVERAL SHORTWAVES WILL LIKELY
QUICKLY PASS ALONG THE LONGWAVE TROUGH AXIS...BRINGING THE THREAT OF
SHORT LIVED SHOTS OF PRECIP THROUGH THE LAST PART OF THE FORECAST.
THE FIRST OF THESE WILL BE TUESDAY NIGHT...WITH SOME POSSIBILITY
THAT THE PRECIP COULD GRAZE OUR FAR NORTHERN COUNTIES IN THE FORM OF
A QUICK LIGHT SNOW. ANOTHER ONE MAY IMPACT THE REGION WEDNESDAY
NIGHT INTO THURSDAY AS WELL.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 731 PM EST THU JAN 1 2015
CLOUDS WILL GRADUALLY LOWER AND ADVANCE NORTHWARD THROUGH THE
NIGHT...WITH LIGHT PRECIPITATION THREATENING MAINLY ALONG AND SOUTH
OF THE HAL ROGERS PARKWAY. THIS WILL FALL AS MAINLY LIGHT
RAIN...HOWEVER SOME SLEET IS ALSO POSSIBLE AT ONSET. EXPECT MVFR
CLOUDS TO MOVE IN THE SOUTH BETWEEN 06 AND 09Z...AND THEN GRADUALLY
BUILD NORTHWARD THROUGH THE DAY ON FRIDAY...WITH LOCATIONS ALONG AND
NORTH OF THE I-64 CORRIDOR LIKELY STAYING VFR UNTIL LATER FRIDAY
EVENING WHEN A WARM FRONT ADVANCES ACROSS THE AREA FROM THE SOUTH.
SOUTHWEST WINDS OF 5 TO 10 KTS...WITH LOCATIONS ALONG THE I-64
CORRIDOR MAINTAINING AROUND 10 KTS...WILL CONTINUE THROUGH THE
NIGHT BEFORE DIMINISHING TOWARDS DAWN.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEOGERIAN
SHORT TERM...ABE
LONG TERM...JMW
AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1140 PM CST THU JAN 1 2015
.AVIATION...
EXPECT LOW CIGS AND WIDESPREAD RAINFALL TO KEEP IFR CONDITIONS
PREVAILING THROUGHOUT THE 06Z TAF PD. ISOLD TSTMS WILL ALSO BE
POSSIBLE ALONG AND E OF A KLFK/KSHV/KELD LINE. WINDS WILL REMAIN
OUT OF THE NE AT 5-10 KTS FOR MUCH OF THE PD...BECOMING VRBL AFTER
SUNSET FRIDAY EVENING. /12/
&&
.PREV DISCUSSION... /ISSUED 840 PM CST THU JAN 1 2015/
DISCUSSION...
WIDESPREAD RAIN CONTINUES ACROSS THE EASTERN TWO THIRDS OF THE
REGION THIS EVENING. HAVE EVEN SEEN SOME ELEVATED THUNDERSTORMS
ACROSS OUR SOUTHERN ZONES ALONG AN ELEVATED INSTABILITY AXIS WHICH
IS SLOWLY TRYING TO ADVANCE NORTHWARD. REGIONAL RADAR MOSAICS
SHOWING SOME BREAKS IN THE COVERAGE ACROSS PORTIONS OF CENTRAL AND
NORTHEAST TEXAS. HOWEVER...OBSERVATIONS STILL SHOWING LIGHT RAIN
WITH MEASURABLE DRIZZLE ONGOING ACROSS THESE OBSERVATIONS SITES.
FOR THE UPDATE...THOUGHT ABOUT LOWERING CATEGORICAL POPS ACROSS
THE WEST OVERNIGHT WHERE THE BREAK IN THE OBSERVABLE COVERAGE
EXISTS BUT THE LATEST HRRR SUGGESTS THAT MORE DEVELOPMENT IS
POSSIBLE ACROSS CENTRAL TX AFTER MIDNIGHT...MOVING INTO OUR NE TX
ZONES. LATEST 00Z NAM OUTPUT SUPPORTS THIS REASONING AS WELL SO
TRIMMED QPF AMOUNTS BACK SOMEWHAT IN THE WEST BUT KEPT THE
CATEGORICAL WORDING. ALSO ADDED THUNDERSTORM MENTION ALONG AND
SOUTH OF A LFK/SHV/MLU LINE THROUGH THE NIGHT AS WELL.
CONCERNING OVERNIGHT TEMPS...EXPECTING VERY LITTLE CHANGE IN
TEMPERATURES THROUGH THE NIGHT. IN FACT...SINCE 4 PM...AMBIENT
TEMPS HAVE EITHER STAYED PUT OR RISEN A DEGREE OR TWO THROUGH THE
EVENING AND WOULD NOT BE SURPRISED TO SEE AN ADDITIONAL DEGREE OR
TWO CLIMB AS THE LOW LEVELS CONTINUE TO WARM. MADE THIS CHANGE TO
THE OVERNIGHT FCST ALONG WITH DEWPOINT AND RH GRIDS.
OTHERWISE...FCST IS IN PRETTY GOOD SHAPE WITH NO OTHER ADDITIONAL
CHANGES NECESSARY...13.
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 39 44 43 55 37 / 100 90 90 90 10
MLU 39 47 45 60 40 / 100 80 90 90 20
DEQ 37 41 39 48 33 / 90 90 90 60 10
TXK 36 41 40 51 35 / 100 90 90 70 10
ELD 37 42 41 53 37 / 100 90 90 90 10
TYR 38 42 40 54 35 / 100 90 90 70 10
GGG 39 43 42 54 36 / 100 90 90 70 10
LFK 43 48 45 56 38 / 100 70 90 90 10
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
12
AREA FORECAST DISCUSSION
NWS CARIBOU ME
104 AM EST FRI JAN 2 2015
.SYNOPSIS...
AN ARCTIC FRONT WILL SWEEP NORTHWEST TO SOUTHEAST THROUGH THE
REGION LATE OVERNIGHT INTO FRIDAY. HIGH PRESSURE WILL BUILD
ACROSS THE REGION FRIDAY NIGHT THROUGH SATURDAY. LOW PRESSURE
TRACKING NORTHWEST OF MAINE WILL ALLOW A WARM FRONT TO APPROACH
THE REGION SUNDAY.
&&
.NEAR TERM /THROUGH TODAY/...
1245 AM UPDATE: ADJUSTED THE POPS TO ALIGN BETTER W/THE LATEST
RADAR AND OBS SHOWING SOME SNOW MOVING ACROSS PORTIONS OF NORTHERN
MAINE. 05Z SURFACE ANALYSIS SHOWED PRE-FRONTAL TROF W/A LOW OVER
NW MAINE PUSHING E. TEH ARCTIC FRONT WAS STILL BACK INTO QUEBEC.
THIS PRE-FRONTAL TROF IS RESPONSIBLE FOR THE FIRST BURST OF SNOW,
MAINLY LIGHT. TEMPERATURES HOLDING IN THE UPPER TEENS AND LOW 20S
ACROSS THE NORTH AND WEST W/LOW TO MID 20S ELSEWHERE. THE MORE
SIGNIFICANT EVENT W/HEAVIER SNOW SHOWERS AND PERHAPS SOME SQUALLS
SET TO MOVE ACROSS NORTHERN AND WESTERN AREAS BETWEEN 3 AND 7 AM.
A QUICK INCH OF SNOW IS POSSIBLE W/SOME GUSTY WINDS. BTV SNOW
SQUALL PARAMETER SHOWS SOME ENHANCED SNOW SHOWERS/SQUALLS ACROSS
NORTHERN MAINE BETWEEN 4 AND 10 AM THIS MORNING. THE NAM12
SOUNDING INDICATED HEAVIEST ACTION BETWEEN 09-15Z AND WAS MATCHING
UP WELL PER 05Z OBS/RADAR.
THE TEMPERATURES WILL STAY UP FOR A TIME AS THE ARCTIC FRONT IS
SLOWER IN ARRIVING PER THE LATEST RAP AND NAM12 GUIDANCE.
TEMPERATURE WILL DROP OFF SHARPLY BEHIND THE FRONT AFTER 10 AM.
THE AFOREMENTIONED FRONT WILL FINISH ITS SOUTHWARD PUSH AND WILL
BE OFFSHORE BY LATER THIS AFTERNOON. AS SUCH, THE BULK OF THE
SNOW SHOWERS WILL COME TO AN END WITH JUST A FEW LINGERING SNOW
FLAKES POSSIBLE OVER NORTHERN MAINE. HIGHS WILL BE CHILLY IN THE
NORTH...10 TO 15 DEGREES...BUT CENTRAL AND SOUTHERN MAINE WILL BE
A BIT BETTER, TOPPING OUT IN THE 20S TO AROUND 30.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY/...
COULD HAVE A SLIGHT CHANCE OF SNOW SHOWERS ACROSS THE
NORTH/MOUNTAINS EARLY FRIDAY NIGHT. OTHERWISE...HIGH PRESSURE
BUILDS EAST TOWARD THE REGION FRIDAY NIGHT WITH DECREASING CLOUDS
NORTH AND MOSTLY CLEAR SKIES DOWNEAST. HIGH PRESSURE THEN CROSSES
THE REGION SATURDAY WITH PARTLY/MOSTLY SUNNY SKIES. LOW PRESSURE
LIFTING ACROSS THE GREAT LAKES WILL DRAW A WARM FRONT TOWARD NEW
ENGLAND SATURDAY NIGHT. CLOUD COVER WILL INCREASE ACROSS THE
REGION EARLY SATURDAY NIGHT. LOW TEMPERATURES SATURDAY NIGHT WILL
OCCUR EARLY THEN BEGIN TO RISE OVERNIGHT WITH THE INCREASING
CLOUDS. OVERRUNNING PRECIPITATION WILL THEN EXPAND ACROSS THE
FORECAST AREA LATER SATURDAY NIGHT. BASED ON CRITICAL
THICKNESSES...EXPECT PRECIPITATION TO REMAIN MOSTLY IN THE FORM OF
SNOW ACROSS THE FORECAST AREA SATURDAY NIGHT. HOWEVER...THE SNOW
COULD BEGIN TO TRANSITION TO A WINTRY MIX ACROSS DOWNEAST AREAS
LATE. THE PRIMARY GREAT LAKES LOW TRACKS NORTHWEST OF THE REGION
SUNDAY DRAWING THE WARM FRONT NORTH ACROSS THE REGION. MODELS
INDICATE THE POSSIBILITY THAT A WEAK SECONDARY LOW COULD DEVELOP
ALONG THE WARM FRONT AND MOVE ALONG THE COAST...THOUGH THE EXTENT
TO WHICH THE LOW DEVELOPS IS UNCERTAIN. EXPECT A WINTRY MIX TO
TRANSITION TO MOSTLY RAIN ACROSS MUCH OF THE DOWNEAST AREA SUNDAY
AFTERNOON...WITH SNOW TRANSITIONING TO A WINTRY MIX ACROSS
NORTHERN AREAS. PRECIPITATION TYPES WILL BE DEPENDENT ON HOW
QUICKLY THE LOW LEVEL COLD AIR CAN BE ERODED. A STRONGER SECONDARY
LOW MOVING ALONG THE COAST WOULD HELP THE LOW LEVEL COLD AIR
REMAIN MORE PERSISTENT ACROSS INTERIOR DOWNEAST AREAS...WHILE A
WEAKER LOW WOULD ALLOW THE LOW LEVEL COLD AIR TO BE ERODED MORE
RAPIDLY. GENERALLY EXPECT STORM TOTAL SNOW ACCUMULATION OF 4 TO 7
INCHES ACROSS NORTHERN AREAS THROUGH SUNDAY WITH 3 TO 5 INCHES
DOWNEAST. SLEET AND ICE ACCUMULATIONS WILL BE DEPENDENT ON THE
TIMING OF THE TRANSITION FROM SNOW WHICH IS STILL UNCERTAIN AT
THIS TIME. TEMPERATURES WILL BE AT BELOW NORMAL LEVELS
SATURDAY...THEN AT ABOVE NORMAL LEVELS SUNDAY DEPENDENT ON THE
EXTENT OF LOW LEVEL WARMING.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
LATEST RUN OF GFS/ECMWF IN GOOD AGREEMENT TRACKING LOW PRESSURE
NORTH OF CWA THROUGH MONDAY WITH STRONG NORTHWEST TO NORTH
GRADIENT ESTABLISHING FOR GUSTY WINDS AND A RAPID DECREASE IN
TEMPERATURES. SNOW SHOWER ACTIVITY...OR MIXED PRECIPITATION ALONG
DOWNEAST...WILL DIMINISH QUICKLY ACROSS THE AREA BY MONDAY NIGHT.
ANOTHER LOW APPROACHES FROM THE GREAT LAKES ON TUESDAY BUT CURRENT
GUIDANCE KEEPS THE SYSTEM OFFSHORE RESULTING IN CHANCE POPS ALONG
DOWNEAST COAST AND SLIGHT CHANCE TO CENTRAL AREAS THROUGH EARLY
THURSDAY. HIGH PRESSURE THEN BUILDS IN FROM THE WEST ON THURSDAY
FOR A BRIEF RESPITE BEFORE A CLIPPER SYSTEM APPROACHES AGAIN FROM
THE WEST. TEMPERATURES THROUGH THE WEEK WILL REMAIN WELL BELOW
NORMALS.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
NEAR TERM: VFR CONDITIONS WILL PREVAIL AT THE SOUTHERN TERMINALS
THROUGH THE PERIOD. HOWEVER, AT KCAR/KFVE/KPQI, A COLD FRONTAL
PASSAGE WILL BRING SNOW SHOWERS AND PERHAPS EVEN SNOW SQUALLS.
PREVAILING MVFR CONDITIONS ARE EXPECTED 22Z THU THRU 12Z FRIDAY,
WITH IFR/LIFR POSSIBLE IN ANY SNOW. CONDITIONS WILL IMPROVE
THROUGH THE DAY FRIDAY WITH LIFTING CEILINGS AND DECREASING
COVERAGE OF SNOW SHOWERS.
SHORT TERM: COULD HAVE LOCALIZED MVFR CONDITIONS ACROSS THE
NORTH AND MOUNTAINS EARLY FRIDAY NIGHT. OTHERWISE...VFR
CONDITIONS ARE EXPECTED ACROSS THE REGION FRIDAY NIGHT INTO EARLY
SATURDAY NIGHT. CONDITIONS WILL LOWER TO IFR/LIFR LEVELS LATER
SATURDAY NIGHT WITH SIMILAR CONDITIONS PERSISTING INTO EARLY
SUNDAY NIGHT. CONDITIONS WILL IMPROVE TO MVFR/VFR LEVELS ACROSS
NORTHERN AREAS LATER SUNDAY NIGHT...WITH VFR CONDITIONS DEVELOPING
DOWNEAST. OCCASIONAL MVFR CONDITIONS COULD PERSIST ACROSS THE
NORTH AND MOUNTAINS MONDAY. OTHERWISE...VFR CONDITIONS ARE
EXPECTED ACROSS THE REGION MONDAY INTO TUESDAY.
&&
.MARINE...
NEAR TERM: A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR TONIGHT,
BUT IT HAS BEEN EXTENDED THROUGH FRIDAY. WINDS WILL INCREASE AHEAD
OF AN APPROACHING COLD FRONT TONIGHT, AND THEN SWITCH TO THE
WEST/NORTHWEST FRIDAY AS THE FRONT CROSSES THE GULF OF MAINE.
WINDS OF 10 TO 20 KT WITH GUSTS UP TO 30 KT ARE EXPECTED THROUGH
THE PERIOD.
SHORT TERM: SMALL CRAFT ADVISORY CONDITIONS WILL OCCUR FRIDAY
NIGHT INTO EARLY SATURDAY. CONDITIONS WILL BRIEFLY FALL BELOW
SMALL CRAFT ADVISORY LEVELS SATURDAY AFTERNOON INTO EARLY
SATURDAY NIGHT. SMALL CRAFT ADVISORY CONDITIONS WILL DEVELOP AGAIN
LATER SATURDAY NIGHT. STRONG SMALL CRAFT ADVISORY...OR POSSIBLY
GALE CONDITIONS...WILL OCCUR SUNDAY. VISIBILITIES WILL LOWER IN
DEVELOPING SNOW AND MIXED PRECIPITATION LATER SATURDAY
NIGHT...WITH MIXED PRECIPITATION CHANGING TO RAIN SUNDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST SATURDAY FOR ANZ050>052.
&&
$$
NEAR TERM...HEWITT
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
333 AM EST FRI JAN 2 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 351 PM EST THU JAN 1 2015
DEEP TROUGH ALOFT CENTERED OVER HUDSON BAY. MULTIPLE SHORTWAVES
MOVING THROUGH THE BASE OF THE TROUGH...BUT AFTER THE SHORTWAVE
MOVED THROUGH THIS MORNING...THERE IS NO LARGER SCALE SUPPORT OVER
THE AREA OR UPSTREAM. PRIMARY COLD FRONT TIED TO THE LAST SHORTWAVE
IS CURRENTLY SINKING SOUTHWARD OVER UPR MICHIGAN. BAND OF HEAVY SNOW
ALONG THE FRONT HAS WORKED THROUGH MARQUETTE AND MUNISING AND IS NOW
ALLIGNED FM SAWYER TO CHATHAM TO SHINGLETON AND TO NEWBERRY AS OF 20Z.
VSBY DOWN TO 1/4SM IN THIS SNOW BAND...BUT IT IS NOT LASTING TOO LONG.
LES OVER THE WESTERN CWA IS SCUFFLING ALONG. IN FACT AFTER THE FRONT
MOVED THROUGH THE KEWEENAW...SPOTS HAVE CLEARED OUT BRIEFLY. HINTS OF
WIND PARALLEL BANDS OVER WESTERN LK SUPERIOR...BUT DRY AIR AND
INVERSIONS BLO 5KFT IS LIMITING THIS DEVELOPMENT. BETTER LES
DEVELOPMENT OVER EASTERN LK SUPERIOR WITH CLOUD STREETS EXTENDING
BACK TO NCNTRL LK SUPERIOR. WILL TAKE A FEW HOURS...BUT DO EXPECT AT
LEAST MODERATE LES TO DEVELOP IN THE NW LOW-LEVEL WINDS INTO EASTERN
CWA. BLYR WINDS OVER 30 KTS INTO THE EVENING WILL RESULT IN BLSN/POOR
VSBY IN THE HEAVIER SNOW BANDS. INVERSIONS 5-8 KFT AND TEMPS AT
INVERSION TOP OF -20C SHOULD AT LEAST RESULT IN SCT HEAVIER SNOW
SHOWERS. 17Z HRRR DOING NICE JOB WITH EXPECTED EVOLUTION THROUGH THE
EVENING...THOUGH IT SEEMS A BIT SLOW WITH TIMING OF HEAVIER SNOW BAND
TIED TO THE FRONT.
ADDITIONAL SNOW AMOUNTS SHOULD STAY IN CHECK GIVEN LACK OF ENHANCED
MOISTURE AND LIFT SINCE WE ARE WITHIN A PURE LES REGIME. SUPPOSE IF
SNOW BANDS CAN STAY ANCHORED IN ONE PLACE THROUGH THE NIGHT...MAY SEE
SEVERAL INCHES OF FLUFFY ACCUMS AS ALL CONVECTIVE DEPTH IS WITHIN THE
DGZ. ALREADY ISSUED LES ADVISORY THROUGH MIDNIGHT FOR ALGER...NORTHERN
SCHOOLCRAFT...AND LUCE COUNTIES. AFTER MIDNIGHT SEEMS THAT DRY AIR
AND LOWER INVERSIONS THAT ARE AFFECTING WESTERN LK SUPERIOR AND CWA
WILL PUT CRIMP IN THE LES INTENSITY OVERNIGHT. WEAK LES WILL CONTINUE
INTO FRIDAY...MAINLY FOR AREAS FAVORED BY WNW-W WINDS...SO ESSENTIALLY
THE SNOW BELTS OF THE KEWEENAW AND ALSO TO THE EAST OF MUNISING.
CONDITIONS EVEN MORE UNFAVORABLE THAN LATER TONIGHT...BUT WITH DGZ
DOMINATING THE CONVECTIVE LAYER STILL COULD SQUEEZE OUT A COUPLE MORE
INCHES OF FLUFF IN PERSISTENT SNOW SHOWERS.
AWAY FM THE LES TONIGHT...LOWERED SKY COVER AND TEMPERATURES AS THE
DRIER AIR SHOULD WIN OUT AS IS OCCURRING UPSTREAM IN MINNESOTA AND
NORTHWEST ONTARIO THIS AFTN. INTERIOR TEMPS SHOULD DIP WELL BLO ZERO
ONCE THE NW WINDS BEHIND THE COLD FRONT BEGIN TO BACK OFF. SHOULD BE
SHARP GRADIENT TO MIN TEMPS AS YOU GET CLOSER TO LK SUPERIOR DUE TO
LINGERING LAKE EFFECT CLOUDS AS 925MB WINDS STAY WNW-NW THROUGH THE
NIGHT. ALSO MAY SEE TEMPS STEADY OR RISE LATE IN THE WEST WITH
ADVANCING DECK OF 6-9KFT ALTOSTRATUS CLOUDS. ANOTHER COOL DAY WITH
AFTN READINGS IN THE TEENS OVER THE CWA.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 333 AM EST FRI JAN 2 2015
NAM SHOWS A 500 MB TROUGH OVER THE SOUTHERN PLAINS 12Z SAT WITH A
TROUGH ALSO IN THE NORTHERN ROCKIES. THE TROUGH IN THE SOUTHERN
PLAINS HEADS NORTHEAST WHILE THE NORTHERN ROCKIES TROUGH HEADS EAST
ON SAT AND THEY COMBINE SAT NIGHT TO CARVE OUT A DEEP TROUGH OVER
THE UPPER GREAT LAKES WHICH REMAINS THROUGH SUN NIGHT. NAM AND GFS
SHOW 850-500 MB Q-VECTOR CONVERGENCE MOVING THROUGH ON SAT AND SAT
NIGHT WITH MORE CONVERGENCE RETURNING FOR SUN NIGHT.
DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST. DID INTRODUCE
SOME POPS IN FOR SATURDAY DUE TO LAKE ENHANCEMENT FROM LAKE MICHIGAN
COMING IN AS LAKE SURFACE TEMPERATURES ARE AROUND 2C TO 4C AND 850
MB TEMPERATURES ON SOUTH WINDS ARE AROUND -6C TO -4C AND THAT IS
ENOUGH FOR SOME LIGHT LAKE ENHANCEMENT POSSIBILITIES ANYWAY AS THE
SOUTHERN SHORTWAVE HEADS NORTHEAST AND CLIPS THE SOUTHERN CWA SAT
AFTERNOON. HAVE HIGH POPS IN FOR SAT NIGHT WITH CATEGORICAL POPS AS
THE TWO SYSTEMS COMBINE OVER THE AREA WITH THE HIGHER QPF AMOUNTS
REMAINING TO THE SOUTHEAST OF THE CWA WITH THE CWA FEELING THE
EFFECTS MOST FROM THE NORTHERN SYSTEM. COL AIR WILL MOVE IN FOR SAT
NIGHT INTO SUNDAY. LAKE EFFECT THEN GETS GOING FOR SUNDAY AND WENT
HIGHEST POPS IN NORTH TO NORTHWEST LAKE EFFECT SNOW BELTS.
IN THE EXTENDED...GFS AND ECMWF SHOW A DEEP 500 MB TROUGH OVER MOST
OF THE U.S. 12Z MON WITH VERY COLD AIR ENTRENCHED OVER THE AREA.
THIS UPPER TROUGH REMAINS OVER THE AREA INTO WED BEFORE THE TROUGH
AXIS AND THE COLDEST AIR MOVE OFF TO THE EAST AND SOME MODIFICATION
IN THE AIRMASS BEGINS FOR THU. TEMPERATURES WILL CONTINUE TO BE WELL
BELOW NORMAL AND LAKE EFFECT SNOW WILL CONTINUE FOR THIS FORECAST
PERIOD AS SFC HIGH PRESSURE REMAINS OVER THE CENTRAL PLAINS FOR THIS
PERIOD. LOOKS LIKE THERE COULD BE AN ALBERTA CLIPPER TYPE SYSTEM
PASSING BY FOR THU.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1153 PM EST THU JAN 1 2015
UNDER A COLD AIR MASS AND WNW FLOW...LAKE EFFECT SNOW SHOWERS WILL
AFFECT KCMX THRU THE FIRST HALF OF THIS FCST PERIOD WITH MVFR
CONDITIONS LIKELY PREVAILING. EXPECT SOME PERIODS OF VFR INITIALLY
AS DRIER AIR HAS CAUSED -SHSN TO DIMINISH. TODAY...BACKING WINDS
SHOULD RESULT IN A ZONE OF ENHANCED CONVERGENCE AND A BAND OF
HEAVIER -SHSN LIFTING N AND IMPACTING KCMX LATE MORNING/EARLY AFTN
WITH IFR CONDITIONS POSSIBLE. THEREAFTER...CONDITIONS SHOULD BECOME
VFR AS SW WINDS PUSH LAKE EFFECT N OF THE TERMINAL. AT KIWD...VFR
CONDITIONS WILL PREVAIL OVERNIGHT AS DRY AIR AND WINDS HAVING JUST
ENOUGH OF A WESTERLY COMPONENT WILL KEEP LAKE EFFECT SNOW
SHOWERS/MVFR CONDITIONS N OF THE TERMINAL. WITH WINDS BACKING
FURTHER TODAY...VFR CONDITIONS WILL CONTINUE AT KIWD. AT KSAW...
DOWNSLOPE COMPONENT TO THE WIND OVERNIGHT SHOULD KEEP CONDITIONS
VFR. VFR CONDITIONS WILL THEN CONTINUE THRU TODAY.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 351 PM EST THU JAN 1 2015
NW GALES DIMINISH THIS EVENING OVER THE EAST HALF. HEAVY FREEZING
SPRAY WILL ALSO END LATE TONIGHT. WINDS SETTLE DOWN TO LESS THAN 25
KTS LATER TONIGHT THROUGH FRIDAY NIGHT AS HIGH PRESSURE MOVES
OVERHEAD. EXPECT A BRIEF PERIOD OF STRONGER SE WINDS ON SATURDAY...BUT
THE BETTER CHANCE OF STRONGER WINDS WILL BE LATE SATURDAY NIGHT INTO
SUNDAY AS NORTH TO NORTHWEST WINDS INCREASE AS A LOW PRESSURE SYSTEM
LIFTS OVER THE GREAT LAKES THEN MOVES EAST OVER QUEBEC. BEST SHOT OF
GALES WILL BE OVER THE EAST HALF OF LK SUPERIOR ON SUNDAY. NW WINDS
TO 30 KTS WILL LINGER OVER MUCH OF LK SUPERIOR INTO EARLY NEXT WEEK
BEHIND THE WEEKEND SYSTEM. MORE HEAVY FREEZING SPRAY IS EXPECTED LATE
THIS WEEKEND INTO EARLY NEXT WEEK AS ARCTIC AIR FLOWS ACROSS LK
SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM LATE SATURDAY NIGHT THROUGH MONDAY MORNING FOR
LSZ266-267.
HEAVY FREEZING SPRAY WATCH FROM SUNDAY EVENING THROUGH TUESDAY
EVENING FOR LSZ267.
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST /6 AM CST/ THIS
MORNING FOR LSZ241>245-263-264-266.
HEAVY FREEZING SPRAY WATCH FROM LATE SATURDAY NIGHT THROUGH
TUESDAY EVENING FOR LSZ266.
GALE WATCH FROM LATE SATURDAY NIGHT THROUGH SUNDAY AFTERNOON FOR
LSZ263>265.
HEAVY FREEZING SPRAY WATCH FROM LATE SATURDAY NIGHT THROUGH LATE
MONDAY NIGHT FOR LSZ263>265.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...07
AVIATION...ROLFSON
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1156 PM EST THU JAN 1 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 351 PM EST THU JAN 1 2015
DEEP TROUGH ALOFT CENTERED OVER HUDSON BAY. MULTIPLE SHORTWAVES
MOVING THROUGH THE BASE OF THE TROUGH...BUT AFTER THE SHORTWAVE
MOVED THROUGH THIS MORNING...THERE IS NO LARGER SCALE SUPPORT OVER
THE AREA OR UPSTREAM. PRIMARY COLD FRONT TIED TO THE LAST SHORTWAVE
IS CURRENTLY SINKING SOUTHWARD OVER UPR MICHIGAN. BAND OF HEAVY SNOW
ALONG THE FRONT HAS WORKED THROUGH MARQUETTE AND MUNISING AND IS NOW
ALLIGNED FM SAWYER TO CHATHAM TO SHINGLETON AND TO NEWBERRY AS OF 20Z.
VSBY DOWN TO 1/4SM IN THIS SNOW BAND...BUT IT IS NOT LASTING TOO LONG.
LES OVER THE WESTERN CWA IS SCUFFLING ALONG. IN FACT AFTER THE FRONT
MOVED THROUGH THE KEWEENAW...SPOTS HAVE CLEARED OUT BRIEFLY. HINTS OF
WIND PARALLEL BANDS OVER WESTERN LK SUPERIOR...BUT DRY AIR AND
INVERSIONS BLO 5KFT IS LIMITING THIS DEVELOPMENT. BETTER LES
DEVELOPMENT OVER EASTERN LK SUPERIOR WITH CLOUD STREETS EXTENDING
BACK TO NCNTRL LK SUPERIOR. WILL TAKE A FEW HOURS...BUT DO EXPECT AT
LEAST MODERATE LES TO DEVELOP IN THE NW LOW-LEVEL WINDS INTO EASTERN
CWA. BLYR WINDS OVER 30 KTS INTO THE EVENING WILL RESULT IN BLSN/POOR
VSBY IN THE HEAVIER SNOW BANDS. INVERSIONS 5-8 KFT AND TEMPS AT
INVERSION TOP OF -20C SHOULD AT LEAST RESULT IN SCT HEAVIER SNOW
SHOWERS. 17Z HRRR DOING NICE JOB WITH EXPECTED EVOLUTION THROUGH THE
EVENING...THOUGH IT SEEMS A BIT SLOW WITH TIMING OF HEAVIER SNOW BAND
TIED TO THE FRONT.
ADDITIONAL SNOW AMOUNTS SHOULD STAY IN CHECK GIVEN LACK OF ENHANCED
MOISTURE AND LIFT SINCE WE ARE WITHIN A PURE LES REGIME. SUPPOSE IF
SNOW BANDS CAN STAY ANCHORED IN ONE PLACE THROUGH THE NIGHT...MAY SEE
SEVERAL INCHES OF FLUFFY ACCUMS AS ALL CONVECTIVE DEPTH IS WITHIN THE
DGZ. ALREADY ISSUED LES ADVISORY THROUGH MIDNIGHT FOR ALGER...NORTHERN
SCHOOLCRAFT...AND LUCE COUNTIES. AFTER MIDNIGHT SEEMS THAT DRY AIR
AND LOWER INVERSIONS THAT ARE AFFECTING WESTERN LK SUPERIOR AND CWA
WILL PUT CRIMP IN THE LES INTENSITY OVERNIGHT. WEAK LES WILL CONTINUE
INTO FRIDAY...MAINLY FOR AREAS FAVORED BY WNW-W WINDS...SO ESSENTIALLY
THE SNOW BELTS OF THE KEWEENAW AND ALSO TO THE EAST OF MUNISING.
CONDITIONS EVEN MORE UNFAVORABLE THAN LATER TONIGHT...BUT WITH DGZ
DOMINATING THE CONVECTIVE LAYER STILL COULD SQUEEZE OUT A COUPLE MORE
INCHES OF FLUFF IN PERSISTENT SNOW SHOWERS.
AWAY FM THE LES TONIGHT...LOWERED SKY COVER AND TEMPERATURES AS THE
DRIER AIR SHOULD WIN OUT AS IS OCCURRING UPSTREAM IN MINNESOTA AND
NORTHWEST ONTARIO THIS AFTN. INTERIOR TEMPS SHOULD DIP WELL BLO ZERO
ONCE THE NW WINDS BEHIND THE COLD FRONT BEGIN TO BACK OFF. SHOULD BE
SHARP GRADIENT TO MIN TEMPS AS YOU GET CLOSER TO LK SUPERIOR DUE TO
LINGERING LAKE EFFECT CLOUDS AS 925MB WINDS STAY WNW-NW THROUGH THE
NIGHT. ALSO MAY SEE TEMPS STEADY OR RISE LATE IN THE WEST WITH
ADVANCING DECK OF 6-9KFT ALTOSTRATUS CLOUDS. ANOTHER COOL DAY WITH
AFTN READINGS IN THE TEENS OVER THE CWA.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 408 PM EST THU JAN 1 2015
A PROMINENT RIDGE GRADUALLLY BUILDING TO THE EAST INTO WRN NOAM WILL
MAINTAIN A BROAD TROUGH FROM CENTRAL CANADA INTO THE GREAT LAKES.
AFTER LOW PRESSURE SYSTEM LIFTS NE FROM THE CNTRL GREAT LAKES...MUCH
COLDER AIR WILL MOVE INTO THE REGION AND REMAIN THROUGH MUCH OF NEXT
WEEK KEEPING LES GOING FOR MAINLY NW TO WNW FLOW FAVORED LOCATIONS.
FRI NIGHT AND SAT...A BROAD 850-600 MB WARM ADVECTION 280K-295
ISENTROPIC LIFT ZONE WILL DEVELOP FROM THE NRN PLAINS INTO NRN MN AND NRN
LAKE SUPERIOR IN RESPONSE TO THE DEVELOPING TROUGH OVER THE PLAINS
AND UPPER LEVEL DIV WITH THE RIGHT ENTRANCE OF A 250-300 MB JET
STREAK THROUGH NRN ONTARIO. THE MODELS KEEP MOST OF THE PCPN WITH
THIS FEATURE NORTH OF UPPER MI. WAA WILL RAISE TEMPS AT OR
SLIGHTLY ABOVE AVERAGE WITH READINGS IN THE MID TO UPPER 20S.
SAT NIGHT INTO SUN...A SHRTWV ORIGINATING FROM THE GULF OF ALASKA
DIVING INTO THE WRN CONUS TROUGH WILL HELP EJECT THE SW CLOSED LOW
NE TOWARD THE GREAT LAKES. THE 12Z GFS/ECMWF ALONG WITH ENSEMBLES
FAVOR A LOW TRACK FROM THE SRN END OF LAKE MI TO CNTRL LAKE HURON
AND THEN NE INTO QUEBEC. STRONG 700-300 MB QVECTOR CONV ASSOCIATED
WITH THE SHRTWV WILL SUPPORT A BROAD AREA OF SNOW FROM WI INTO UPPER
MI BY LATE SAT AND ESPECIALLY LATE SAT NIGHT. MDLS CONSENSUS QPF IN
THE 0.20 TO 0.35 INCH RANGE WITH SLR VALUES AROUND 14/1 WILL SUPPORT
POTENTIAL FOR 3 TO 6 INCHES BY 18Z/SUN. ADDITIONAL SUPPORT FOR
HEAVIER SNOW IS EXPECTED OVER THE NORTH CYCLONIC NRLY FLOW AND 850
MB TEMPS DROPPING FROM -10C TO -15C BY 12Z TO -14C TO -19C BY 18Z
WILL RESULT HIGHER AMOUNTS THROUGH LAKE ENHANCEMENT. BY SUN
AFTERNOON THE DEEPER MOISTURE AND SYNOPTIC SUPPORT LIFT QUICKLY WITH
A TRANSITION TO LIGHTER PURE LES.
SUN NIGHT INTO MON...VERY COLD ARCTIC AIR WILL PLUNGE INTO THE
REGION WITH 850 MB TEMPS DROPPING TO AROUND -27C BY 12Z MON. THIS
WILL LOWER THE DGZ TOWARD THE SFC AND REDUCE POTENTIAL FOR
SIGNIFICANT LES. HOWEVER...WIND CHILL WITH A MORE WRLY SFC WIND
COMPONENT RESULTING FROM LAKE INDUCED TROUGHING WILL ALLOW TEMPS TO
DROP OFF OVER MUCH OF THE CWA. WIND CHILL VALUES IN THE -20 TO -35
RANGE ARE EXPECTED.
TUE-THU...A FEW CLIPPER SHRTWVS ARE LIKELY TO MOVE THROUGH THE REGION WITH
NW-NNW MID LEVEL FLOW IN PLACE. THIS MAY BRING REINFORCING BOUTS OF
COLD AIR AND SHIFT THE POSITIONS OF THE HEAVIER LES BANDS. TEMPS MAY
MODERATE SLIGHTLY IF SFC WINDS VEER MORE TO THE NW WITH MORE MARINE
MODIFICATION. HOWEVER...WIND CHILLS MAY REMAIN NEAR ADVY THRESHOLD
DURING THE LATER NIGHT INTO MORNING HOURS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1153 PM EST THU JAN 1 2015
UNDER A COLD AIR MASS AND WNW FLOW...LAKE EFFECT SNOW SHOWERS WILL
AFFECT KCMX THRU THE FIRST HALF OF THIS FCST PERIOD WITH MVFR
CONDITIONS LIKELY PREVAILING. EXPECT SOME PERIODS OF VFR INITIALLY
AS DRIER AIR HAS CAUSED -SHSN TO DIMINISH. TODAY...BACKING WINDS
SHOULD RESULT IN A ZONE OF ENHANCED CONVERGENCE AND A BAND OF
HEAVIER -SHSN LIFTING N AND IMPACTING KCMX LATE MORNING/EARLY AFTN
WITH IFR CONDITIONS POSSIBLE. THEREAFTER...CONDITIONS SHOULD BECOME
VFR AS SW WINDS PUSH LAKE EFFECT N OF THE TERMINAL. AT KIWD...VFR
CONDITIONS WILL PREVAIL OVERNIGHT AS DRY AIR AND WINDS HAVING JUST
ENOUGH OF A WESTERLY COMPONENT WILL KEEP LAKE EFFECT SNOW
SHOWERS/MVFR CONDITIONS N OF THE TERMINAL. WITH WINDS BACKING
FURTHER TODAY...VFR CONDITIONS WILL CONTINUE AT KIWD. AT KSAW...
DOWNSLOPE COMPONENT TO THE WIND OVERNIGHT SHOULD KEEP CONDITIONS
VFR. VFR CONDITIONS WILL THEN CONTINUE THRU TODAY.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 351 PM EST THU JAN 1 2015
NW GALES DIMINISH THIS EVENING OVER THE EAST HALF. HEAVY FREEZING
SPRAY WILL ALSO END LATE TONIGHT. WINDS SETTLE DOWN TO LESS THAN 25
KTS LATER TONIGHT THROUGH FRIDAY NIGHT AS HIGH PRESSURE MOVES
OVERHEAD. EXPECT A BRIEF PERIOD OF STRONGER SE WINDS ON SATURDAY...BUT
THE BETTER CHANCE OF STRONGER WINDS WILL BE LATE SATURDAY NIGHT INTO
SUNDAY AS NORTH TO NORTHWEST WINDS INCREASE AS A LOW PRESSURE SYSTEM
LIFTS OVER THE GREAT LAKES THEN MOVES EAST OVER QUEBEC. BEST SHOT OF
GALES WILL BE OVER THE EAST HALF OF LK SUPERIOR ON SUNDAY. NW WINDS
TO 30 KTS WILL LINGER OVER MUCH OF LK SUPERIOR INTO EARLY NEXT WEEK
BEHIND THE WEEKEND SYSTEM. MORE HEAVY FREEZING SPRAY IS EXPECTED LATE
THIS WEEKEND INTO EARLY NEXT WEEK AS ARCTIC AIR FLOWS ACROSS LK
SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR MIZ006-
007-085.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 1 AM EST FRIDAY FOR LSZ265-
267.
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST /6 AM CST/ FRIDAY
FOR LSZ241>245-263-264-266.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...JLB
AVIATION...ROLFSON
MARINE...JLA
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1144 PM CST Thu Jan 1 2015
.UPDATE:
Issued at 1005 PM CST Thu Jan 1 2015
Activity picking up a bit on radar as of 04z. Fairly light, in the
form of light rain and some sleet being reported. With further
north placement, upped pops to slight chance as far north as I-70
through the early morning hours of Friday.
Byrd
&&
.SHORT TERM: (Tonight and Friday)
Issued at 338 PM CST Thu Jan 1 2015
The area is sandwiched between high pressure to the south and a trof
of low pressure up across the Upper Midwest. Southwest flow is the
result and temperatures have rebounded into the mid and upper 30s
across the entire area. With abundant cloud cover and weak
southwest flow continuing tonight, expect that lows tonight will be
several degrees warmer tonight than they were last night. Most
areas should get back down below freezing again, but think temps
should stay mostly in the upper 20s to low 30s across the majority
of the area (with the exception of northern MO and west central IL
where clouds should be thinner allowing for more radiational
cooling). NAM, GFS, and RAP develop some weak moisture convergence
on the 850mb baroclinic zone Friday morning just south of the STL
Metro area. While the GFS says dry, the NAM and to a lesser extent
the RAP do print out a little very light QPF. 4km NCEP and NSSL WRF
models also show very light QPF Friday morning, and light simulated
radar returns as well. Therefore, feel there`s enough signal to
bump up PoPs slightly for Friday morning along and southeast of
I-44/US-50. P-types will likely start out as a little rain/sleet
mix and where temps are below freezing there could be a bit of
glaze, but amounts look very light. Precip should turn quickly to
light rain or just sprinkles with a couple of hours of sunrise, and
highs look to be in the mid to upper 30s across the area on Friday.
Carney
.LONG TERM: (Friday Night through Next Thursday)
Issued at 421 PM CST Thu Jan 1 2015
Models are coming into better consensus with the storm system for
Friday night and Saturday. GFS and NAM continue to warm up bit by
bit. Most recent partial thickness forecasts show all critical
thickness lines for rain/snow well up into northern
Missouri/southern Iowa by the time the precipitation starts on
Friday night. Forecast soundings also have little or no cold layer
in the low levels indicating that sleet is becoming less and less
likely. So have more or less confined any chances of sleet to
northern zones Friday evening, changing over to all rain and
freezing rain where surface temperatures dictate. Think any
accumulations of freezing rain will be minor due to warm ground
temperatures and diabatic warming due to latent heat release.
Temperatures should warm above freezing after sunrise on Saturday
morning at any rate which should stop any ice accumulation. Think
the greatest amount of accumulation will be over northern MO and
west central IL and amounts should be between a trace and 0.05 inch.
Dry slot should wrap around into the storm on Saturday afternoon
which will likely make the rain slack off and even end across
southern portions of the area. Cold front moves through Saturday
evening with the tail end of the def-zone clipping our area.
Guidance seems to want to keep the majority of the QPF out of our
area over northwest Missouri and southern Iowa. However, it looks
like our northwest counties could get clipped with an inch or two of
snow before all the shouting is over.
Remainder of the forecast looks cold and dry as a longwave trof
deepens over the eastern CONUS. This will allow a couple of Arctic
air intrusions into the lower 48...one on Sunday and Monday behind
the weekend storm, and another midweek. This should keep
temperatures well below normal through the end of the forecast
period.
Carney
&&
.AVIATION: (For the 06z TAFs through 06z Friday Night)
Issued at 1134 PM CST Thu Jan 1 2015
Patchy light rain mixed at times with light sleet will impact the
St. Louis area terminals through 07-08z, otherwise VFR flight
conditions expected overnight. Still anticipating MVFR cigs moving
into KCOU and the St. Louis terminals around daybreak and gradually
lowering cigs during the afternoon. Main thrust of precipitation
in the form of rain should begin on Friday evening and have
introduced some PROB30 groups for initial estimate of the onset
timing. IFR flight conditions and nearly continuous rainfall
expected to evolve after 06z Saturday.
Specifics for KSTL:
Patchy light rain mixed at times with light sleet will be possible
through around 07z, otherwise VFR flight conditions expected
overnight. Still anticipating MVFR cigs moving into KSTL near daybreak
and gradually lowering cigs during the afternoon. Main thrust of
precipitation in the form of rain should begin on Friday evening
and have introduced a PROB30 group for initial estimate of the
onset timing at 03z. IFR flight conditions and nearly continuous
rainfall expected to evolve after 06z Saturday.
Glass
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1009 PM CST Thu Jan 1 2015
.UPDATE:
Issued at 1005 PM CST Thu Jan 1 2015
Activity picking up a bit on radar as of 04z. Fairly light, in the
form of light rain and some sleet being reported. With further
north placement, upped pops to slight chance as far north as I-70
through the early morning hours of Friday.
Byrd
&&
.SHORT TERM: (Tonight and Friday)
Issued at 338 PM CST Thu Jan 1 2015
The area is sandwiched between high pressure to the south and a trof
of low pressure up across the Upper Midwest. Southwest flow is the
result and temperatures have rebounded into the mid and upper 30s
across the entire area. With abundant cloud cover and weak
southwest flow continuing tonight, expect that lows tonight will be
several degrees warmer tonight than they were last night. Most
areas should get back down below freezing again, but think temps
should stay mostly in the upper 20s to low 30s across the majority
of the area (with the exception of northern MO and west central IL
where clouds should be thinner allowing for more radiational
cooling). NAM, GFS, and RAP develop some weak moisture convergence
on the 850mb baroclinic zone Friday morning just south of the STL
Metro area. While the GFS says dry, the NAM and to a lesser extent
the RAP do print out a little very light QPF. 4km NCEP and NSSL WRF
models also show very light QPF Friday morning, and light simulated
radar returns as well. Therefore, feel there`s enough signal to
bump up PoPs slightly for Friday morning along and southeast of
I-44/US-50. P-types will likely start out as a little rain/sleet
mix and where temps are below freezing there could be a bit of
glaze, but amounts look very light. Precip should turn quickly to
light rain or just sprinkles with a couple of hours of sunrise, and
highs look to be in the mid to upper 30s across the area on Friday.
Carney
.LONG TERM: (Friday Night through Next Thursday)
Issued at 421 PM CST Thu Jan 1 2015
Models are coming into better consensus with the storm system for
Friday night and Saturday. GFS and NAM continue to warm up bit by
bit. Most recent partial thickness forecasts show all critical
thickness lines for rain/snow well up into northern
Missouri/southern Iowa by the time the precipitation starts on
Friday night. Forecast soundings also have little or no cold layer
in the low levels indicating that sleet is becoming less and less
likely. So have more or less confined any chances of sleet to
northern zones Friday evening, changing over to all rain and
freezing rain where surface temperatures dictate. Think any
accumulations of freezing rain will be minor due to warm ground
temperatures and diabatic warming due to latent heat release.
Temperatures should warm above freezing after sunrise on Saturday
morning at any rate which should stop any ice accumulation. Think
the greatest amount of accumulation will be over northern MO and
west central IL and amounts should be between a trace and 0.05 inch.
Dry slot should wrap around into the storm on Saturday afternoon
which will likely make the rain slack off and even end across
southern portions of the area. Cold front moves through Saturday
evening with the tail end of the def-zone clipping our area.
Guidance seems to want to keep the majority of the QPF out of our
area over northwest Missouri and southern Iowa. However, it looks
like our northwest counties could get clipped with an inch or two of
snow before all the shouting is over.
Remainder of the forecast looks cold and dry as a longwave trof
deepens over the eastern CONUS. This will allow a couple of Arctic
air intrusions into the lower 48...one on Sunday and Monday behind
the weekend storm, and another midweek. This should keep
temperatures well below normal through the end of the forecast
period.
Carney
&&
.AVIATION: (For the 00z TAFs through 00z Friday Evening)
Issued at 528 PM CST Thu Jan 1 2015
Present indications are that VFR flight conditions should prevail
tonight although will have to keep an eye on a few patches of MVFR
cigs floating around southern MO. We should see MVFR cigs begin to
spread northeast into KCOU and the St. Louis terminals around
daybreak and gradually lower during the day. There might also be
some patchy light rain in the St. Louis area between around 12-15z,
but confidence is no greater than a PROB group - surface temps
should be just above freezing.
Specifics for KSTL:
Present indications are that VFR flight conditions should prevail
tonight although will have to keep an eye on a few patches of MVFR
cigs floating around southern MO. We should see MVFR cigs begin to
spread northeast into the St. Louis terminals around daybreak and
gradually lower during the day. There might also be some patchy
light rain between around 12-15z, but confidence is no greater
than a PROB group - surface temps should be just above freezing.
Glass
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
103 AM EST FRI JAN 2 2015
.SYNOPSIS...
ACCUMULATING LAKE EFFECT SNOW WILL OCCUR TO THE SOUTHEAST OF LAKE
ONTARIO THROUGH FRIDAY NIGHT. A MORE WIDESPREAD STORM SYSTEM IS
EXPECTED TO BRING A MIX OF SNOW...SLEET AND FREEZING RAIN INTO THE
AREA BY LATE SATURDAY AFTERNOON. THE WINTRY MIX WILL THEN CHANGE
TO RAIN DURING THE NIGHT...FOLLOWED BY WARMER TEMPERATURES AND
SHOWERS ON SUNDAY.
&&
.NEAR TERM /THROUGH TODAY/...
10 PM UPDATE...
SOUTHERN PERIPHERY OF LAKE ONTARIO SNOW BAND IS JUST NOW TOUCHING
THE FAR NORTHERN BORDER OF ONEIDA COUNTY. BASED ON WINDS OFF THE
LAKE AND LATEST MESO MODEL OUTPUT, BELIEVE THE BAND WILL DROP INTO
OUR FA IN THE NEXT 2 TO 3 HOURS. SNOWFALL INTENSITIES COULD REACH
1 TO 2 INCHES PER HOUR BETWEEN 6Z AND 12Z.
THE SYR BUFKIT PROFILE OFF THE 18Z NAM SUGGESTS THE BAND WILL DROP
SOUTH TO I-90 LATE TOMORROW MORNING OR EARLY AFTERNOON. WILL NEED
TO WATCH IF THE BAND CAN MAKE IT DOWN INTO THE CITY. IT WILL BE A
VERY CLOSE CALL REGARDLESS.
RAISED MINS FOR MOST LOCALES OVERNIGHT. SOUTHWESTERLY FLOW THIS
EVENING HAS HELD TEMPS NEAR 30 DEGREES IN MANY SPOTS. USED A
COMBINATION OF LAMP AND RAP HOURLY GUIDANCE FOR OVERNIGHT TEMPS.
3 PM UPDATE...
LOWER CLDS EXPECTED ALONG NRN ZONES AS MOISTURE CONTS TO STREAM
OFF OF UPSTREAM LKS IN SW FLOW. MAJORITY OF CWA SEEING FILTERED
SUNSHINE THRU HIGH CIRRUS. SFC LOW LOCATED NR HUDSON BAY AND CDFNT
EXTNDG BACK TO THE SW THRU LK SUPERIOR WL SHIFT SOUTH TONIGHT.
ADDED LIFT ALONG FRONT COMBINED WITH LK MOISTURE WL SET THE STAGE
FOR SIGNIFICANT LK SNOWS FOR LATE TONIGHT AND FRIDAY.
SNOWS WL BEGIN TO DROP INTO EXTRM NRN ONEIDA CNTY ARND MIDNIGHT
TONIGHT WITH DEEP INVERSION BCMG ESTABLISHED DRG THE MID-MRNG HRS.
INVERSION LOOKS TO BE ABOUT 7KFT DEEP WITH WELL-ALIGNED FLOW AND
QUITE A BIT OF INSTABILITY. AS THE CDFNT SHIFTS SOUTH AFT DAYBREAK
WINDS WL ALIGN FM A 280-290 FLOW AND RESULT IN SINGLE BAND OF SNOW.
LOOKS AS THO GEORGIAN BAY CONNECTION WL BE ESTABLISHED DRG THE LATE
MRNG/AFTN HRS. BAND LOOKS TO BE FAIRLY STEADY-STATE BTWN 15Z-21Z THO
IT WL BE WOBBLING A BIT. THUS EXPECT MAX SNOWFALL RATES OF 1-2
INCHES PER HR DRG THE LATE MRNG HRS AND POSSIBLY INTO THE AFTN.
AS DIURNAL HTG BEGINS TO WORK IT`S MAGIC EXPECT THAT SINGLE BAND WL
GO MORE CELLULAR DRG THE AFTN AND INTENSITY WL GRADUALLY BEGIN TO
LESSEN. STORM TOTAL SNOW ACCUMS FM 03Z TONIGHT TO 00Z SAT WL RANGE
FM 5-8 INCHES NORTH OF THE NY THRUWAY. EXCEPTION WL BE EXTRM NW
ONEIDA CNTY WHERE UP TO ONE FOOT OF SNOW IS EXPECTED TO FALL. THUS
HV GONE WITH LES WARNING FOR NRN ONEIDA AND LES ADVISORY FOR
ONONDAGA, MADISON AND SRN ONEIDA CNTYS FM 03Z TONIGHT TO 00Z SAT.
SNOWS WL SLIDE NORTH ON FRI NGT AND CONTRACT BACK TWD THE SHORE LINE
WITH JUST SCTD SNOW SHOWERS AS WINDS BACK ARND TO THE SW. 1035MB SFC
HIGH WL SETTLE ACRS SRN QUEBEC FRI NGT WITH RIDGE AXIS EXTNDG SWRD
INTO CWA ASSURING A QUIET NIGHT WHILE WE WAIT FOR THE NEXT SYSTEM.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
GLOBAL AND REGIONAL COMPUTER MODELS FROM AROUND THE WORLD REMAIN
CONSISTENT WITH A LOW PRESSURE AREA LIFTING OUT OF THE SOUTHERN
PLAINS EARLY THIS WEEKEND...AND TRACKING THROUGH THE GREAT LAKES
AND EASTERN CANADIAN PROVINCES ON SUNDAY. THE OVERALL PATTERN
RECOGNITION OF THIS SYSTEM SUGGESTS A RAPIDLY TRANSITIONING WINTRY
MIX EVOLVING OVER CNY AND NEPA FROM SATURDAY AFTERNOON TO EARLY
SUNDAY MORNING. AT THIS STAGE OF THE GAME...THE BEST SOLUTION IS
TO STILL BLEND THE VARIOUS GUIDANCE PACKAGES TO DETERMINE THE
THERMAL PROFILES AND RESULTING TIMING OF THE VARIOUS PRECIP TYPES.
MOST OF THE FIELDS ARE WITHIN A DEGREE OR TWO...BUT IT WAS NOTED
THAT THE NAM WAS SUGGESTING SLIGHTLY COLDER SFC VALUES AND WARMER
THICKNESS PATTERNS ALOFT AS THE PRECIP MOVES IN. OTHERWISE...THE
DETAILED SOUNDING PROFILES INDICATE THE WARM LAYERS TO BE FAIRLY
HIGH IN THE ATMOSPHERE WITH A SUBSTANTIAL (4-5 KFT) DEPTH OF SUB
FREEZING AIR TO THE SURFACE. THIS ACTUALLY SUGGESTS THERE COULD BE
A FAIR AMOUNT OF SLEET GOING ON WITH THE SNOW AND BETWEEN THE
CHANGE TO FRZG RAIN AND RAIN. ISENTROPIC LIFT SHOULD ALLOW PRECIP
TO BREAK OUT A LITTLE SOONER THAN WHAT THE GFS/ECMWF HAD
PREVIOUSLY ADVERTISED. THE NAM WAS THE FASTEST WITH ONSET...BUT
NOW LOOKS LIKE THE 12Z GFS HAS CAUGHT UP...SO THERE WILL BE
ADJUSTMENTS TO CATEGORICAL/LIKELY POPS BY A FEW HOURS TO INDICATE
PRECIP COMING DOWN IN THE AREA BY DARK. AMOUNTS OF ANY ONE P-TYPE
LOOK TO BE LIMITED GIVEN WHAT IS EXPECTED TO BE ONLY A SHORT
AMOUNT OF RESIDENT TIME FOR THE PHASE CHANGES. MOST AREAS SHOULD
SEE ONLY A COUPLE INCHES OR LESS OF SNOW/SLEET...AND A GLAZE OF
ICE ACCRETION. WARM AIR ALOFT QUICKLY EXCEEDS 3 DEG CELSIUS WHICH
CAN INDICATE THE RAIN IS WARM AND WILL HAVE DIFFICULTY ACCRETING
ON SURFACES. STILL...A FZRA EVENT IS NOTHING TO SNEEZE AT AND
PREPARATIONS TO MITIGATE THE TRAVEL HAZARD SHOULD BE PLANNED FOR
THIS WEEKEND.
BEHIND THIS SYSTEM...A SHORT...MILD SPELL IS EXPECTED IN A NARROW
WARM SECTOR ON SUNDAY WITH A FEW RAIN SHOWERS AS THE SYSTEM DRY
SLOT PUSHES OVERHEAD. THEN...A RETURN TO THE ARCTIC AIR IS LIKELY
AND THE PATTERN SUGGESTS THERE COULD BE ANOTHER ROUND OF
SIGNIFICANT LAKE EFFECT POURING OFF THE EASTERN AND SOUTHEASTERN
SHORES OF LAKE ONTARIO AND INTO THE SYRACUSE-ROME-UTICA AREAS FROM
SUNDAY NIGHT THROUGH MONDAY NIGHT. WE HAVE FAIRLY GOOD CONFIDENCE
IN THIS EVENT OCCURRING...AND HAVE BUMPED UP POPS IN THE LAKE BELT
ZONES DURING THAT TIME.
NORTHWEST WINDS SHOULD ALSO BEGIN CRANKING UP WITHIN THE COLD
ADVECTIVE AND UNSTABLE REGIME...WITH A POTENTIAL FOR SUSTAINED
WIND SPEEDS IN THE 15-25 MPH WITH GUSTS INTO THE 30S FROM SUN
NIGHT INTO MONDAY.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
LAKE EFFECT EVENT WILL PROBABLY BE ONGOING AT THE BEGINNING OF
THIS PERIOD...ONLY TO BE INTERRUPTED BY A PASSING UPPER WAVE AND
CLIPPER TYPE SURFACE LOW ON TUESDAY AS INDICATED BY BOTH ECMWF AND
GFS. THIS WILL LIKELY MEAN A CHANCE FOR WIDESPREAD LIGHT SNOW OF A
FEW INCHES. EVEN COLDER AIR USHERS IN ON THE BACKSIDE OF THAT LOW
WITH A CONTINUATION OF BROAD CYCLONIC FLOW ALOFT OVER THE AREA. A
STRONG 1040-1045 MB HIGH TO OUR WEST AND COLD NORTHWEST BOUNDARY
LAYER FLOW WILL ONCE AGAIN REKINDLE THE LAKE EFFECT SNOWS AND
UPSLOPE INSTABILITY SNOW SHOWERS THROUGH NEXT THURSDAY.
GENERALLY FOLLOWED THE WPC GUIDANCE GRIDS WITH MINOR ADJUSTMENTS
TO POPS FOR LAKE EFFECT.
COLDER THAN NORMAL ALL NEXT WEEK AND UNSETTLED SEEMS TO BE THE
OVERALL THEME.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
06Z UPDATE...
PASSAGE OF A SURFACE TROUGH IS IN THE PROCESS OF REDIRECTING LAKE
EFFECT SNOW TO KSYR-KRME CORRIDOR. MINOR RESTRICTIONS ARE
ONGOING...WITH FURTHER DEGRADATION TO FUEL ALT REQ MVFR CIG AND IFR
VIS FIGURED FOR 10Z-14Z TIME PERIOD KRME...AND AT LEAST 11Z- 15Z
FOR KSYR AS THE LAKE EFFECT BAND SHIFTS OVER THOSE TERMINALS. BAND
LOOKS LIKELY TO SET UP NEAR KSYR FOR A FAIR CHUNK OF THE DAY EVEN
AFTER 15Z...WHILE BEING MAINLY SOUTH OF KRME /THOUGH STILL MVFR/
BEFORE REVISITING WHILE SHIFTING NORTH THIS EVENING. SOME
UNCERTAINTY ON DURATION OF THAT SINCE INLAND EXTENT OF LAKE EFFECT
WILL BE DECREASING WITH TIME THIS EVENING. FOR KELM-KITH-
KBGM...IN-AND-OUT OF MVFR CONDITIONS AS LAKE ERIE CLOUDS WILL BE
PRESENT THROUGH MOST OF THE TAF PERIOD...WITH OCCASIONAL FLURRIES.
KAVP VFR WHOLE PERIOD. CURRENT WSW TO W WINDS 9-12 KTS WILL VEER
WITH TROUGH PASSAGE TO WNW DURING THE DAY...WITH GUSTS AROUND 20
KTS...BEFORE DIMINISHING LATE AFTERNOON-EVENING.
OUTLOOK...
SAT/SAT NGT...BECOMING IFR WITH SNOW DEVELOPING, CHANGING TO
WINTRY MIX AND OCNL RAIN/FRZG RAIN OVERNIGHT.
SUN...MAINLY VFR. SCT RAIN SHOWERS.
MON-TUE...SCT SNOW SHOWERS AND MINOR RESTRICTIONS...BUT MORE
SIGNIFICANT RESTRICTIONS POSSIBLE KSYR-KRME FROM LAKE EFFECT SNOW.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR
NYZ018-036-037.
LAKE EFFECT SNOW WARNING UNTIL 7 PM EST THIS EVENING FOR
NYZ009.
&&
$$
SYNOPSIS...PVF
NEAR TERM...DJP/PVF
SHORT TERM...JAB
LONG TERM...JAB
AVIATION...MDP
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1245 AM EST FRI JAN 2 2015
.SYNOPSIS...HIGH PRESSURE WILL EXTEND OVER THE ARE TODAY. A WARM
FRONT OVER THE GULF COAST WILL MOVE NORTHWARD INTO THE REGION LATE
TODAY THROUGH SATURDAY... AS ASSOCIATED LOW PRESSURE TRACKS FROM THE
DEEP SOUTH NORTHWARD TO THE GREAT LAKES. A COLD FRONT WILL CROSS THE
CAROLINAS FROM THE WEST ON SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 906 PM THURSDAY...
THE LATEST SATELLITE DATA INDICATED A RAPID INCREASE IN CLOUDINESS
AT SEVERAL LEVELS FROM THE WEST THIS EVENING. GIVEN THE EXTENSIVE
CLOUDINESS AND MOISTURE UPSTREAM ESPECIALLY IN THE MID AND HIGH
LEVELS... THE SKIES OVERNIGHT WILL BE MOSTLY CLOUDY TO CLOUDY. THERE
MAY BE A FEW THIN SPOTS OR BREAKS IN THE OVERCAST BUT THE CLOUDINESS
COMBINED WITH THE LIGHT SW FLOW AT 5-10 MPH SHOULD KEEP TEMPERATURES
IN CHECK. READINGS AT MID EVENING RANGED IN THE LOWER TO MID 40S
EXCEPT FOR SOME UPPER 30S WHERE THE CLOUDS WERE YET TO THICKEN UP.
TEMPERATURES SHOULD ONLY FALL OFF ABOUT 5 MORE DEGREES OR SO THEN
LEVEL OFF AS THE CLOUDS THICKEN. LOWS IN THE MID 30S TO NEAR 40
EXPECTED.
AS FOR THE PRECIPITATION CHANCES... RADAR INDICATED PATCHY LIGHT
RAIN ALREADY SPREADING GEORGIA AND MUCH OF TENNESSEE. HOWEVER...
THERE CONTINUED TO BE QUITE A BIT OF DRY AIR TO OVERCOME FROM THE
BOUNDARY LAYER THROUGH H7. MOST OF THE PRECIPITATION IS EXPECTED TO
FALL AS VIRGA THROUGH AT LEAST 12Z GIVEN THE AMOUNT OF DRY AIR TO
MOISTEN UP. THE HRRR INDICATED SOME LIGHT QPF (POSSIBLY 0.01 OR SO)
ACROSS THE SOUTH LATE.
&&
.SHORT TERM /FRIDAY AND FRIDAY NIGHT/...
AS OF 320 PM THURSDAY...
THE CLOSED LOW CENTERED NEAR THE FOUR CORNERS REGION EARLY FRIDAY
WILL SHIFT EAST REACHING THE TEXAS PANHANDLE BY SATURDAY MORNING. AT
THE SAME TIME...SURFACE HIGH PRESSURE DEVELOPS OVER THE NORTHEAST IN
RESPONSE TO THE STRONG CONVERGENT FLOW ALOFT. THIS AREA OF HIGH
PRESSURE RIDGES INTO THE CAROLINAS BY EARLY SATURDAY
MORNING...SETTING THE STAGE FOR ANOTHER COLD AIR DAMMING EVENT OVER
THE WEEKEND. PRECIPITATION IS LIKELY TO BE PRETTY SPOTTY ON FRIDAY
MORNING GIVEN THE WEAK FORCING FOR ASCENT AND LARGELY FOCUSED TO THE
WEST AND SOUTH OF GREENSBORO AND SANFORD. AS DEEP LAYER ISENTROPIC
LIFT INCREASES LATE FRIDAY AND FRIDAY NIGHT...EXPECT PRECIPITATION
IN THE FORM OF RAIN TO OVERSPREAD AND EXPAND ACROSS CENTRAL NC. THIS
WILL SUPPORT CHANCE POPS FRIDAY EVENING INCREASING TO LIKELY
OVERNIGHT. A COOL AIR MASS AND WIDESPREAD CLOUDINESS SHOULD KEEP
TEMPERATURES IN THE 50 TO 55 RANGE ON FRIDAY. LOWS FRIDAY NIGHT WILL
FALL INTO THE UPPER 30S TO LOWER 40S. -BLAES &&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
AS OF 220 PM THURSDAY...
SATURDAY THROUGH SUNDAY NIGHT: THE UPPER LEVEL LOW OVER THE TX
PANHANDLE REGION EARLY SATURDAY WILL MIGRATE NNE INTO THE MID WEST
WHERE IT WILL MERGE WITH THE NORTHERN STREAM TROUGH BY LATE
SATURDAY. THE LOW WILL THEN BECOME MORE OF A SHORTWAVE SLIDING NE
ALONG THE EASTERN PERIPHERY OF THE TROUGH THROUGH THE GREAT LAKES AND
INTO NE CANADA BY SUNDAY NIGHT. THE MAIN TROUGH WILL LINGER OVER THE
MIDWEST ON SUNDAY...PUSHING INTO THE CAROLINAS AND FLATTENING OUT BY
MONDAY AFTERNOON. AT THE SURFACE...HIGH PRESSURE CENTERED OVER THE
NE ON SATURDAY WILL RIDGE SW INTO WESTERN NC...SETTING UP A COLD AIR
WEDGE OVER THE NW PIEDMONT. ALSO ON SATURDAY...A LOW WILL DEVELOP
OVER THE TX GULF COAST AND MOVE NNE INTO THE MID WEST AND THROUGH
THE GREAT LAKES BY SUNDAY EVENING...TRAILING A COLD FRONT BEHIND IT.
AS THE SURFACE LOW BEGINS IT TREK NNE...A WARM FRONT WILL BEGIN
LIFTING NORTHWARD THROUGH NC WHERE IT WILL IMPINGE UPON THE WEDGE
BOUNDARY. THE WEDGE WILL LIKELY REMAIN OVER THE NW PIEDMONT THROUGH
SATURDAY NIGHT...BREAKING ON SUNDAY...ALLOWING THE WARM FRONT TO
LIFT THROUGH THE REST OF CENTRAL NC FOR A BRIEF PERIOD BEFORE THE
COLD FRONTAL PASSAGE SUNDAY NIGHT. THE WARM MOIST ADVECTION AHEAD OF
THE COLD FRONT WILL BE STRONG...WHICH WILL RESULT IN TEMPS WELL
ABOVE NORMAL...ESPECIALLY IN THE SE SOUTH OF THE WARM FRONT.
HOWEVER...GIVEN THE UNCERTAINTY OF WHEN AND IF THE WEDGE WILL BREAK
AHEAD OF THE COLD FRONT...CONFIDENCE IN THE TEMPERATURES FOR SUNDAY
AND SUNDAY NIGHT IS STILL RELATIVELY LOW. THE MODELS INDICATE A FEW
HUNDRED JOULES OF CAPE ON SUNDAY AHEAD OF THE FRONT...THUS HAVE GONE
AHEAD AND ADDED A SLIGHT CHANCE FOR THUNDER INTO THE FORECAST FOR
SUNDAY AFTERNOON THROUGH APPROX MIDNIGHT. THE MODELS ARE IN BETTER
AGREEMENT WITH THE TIMING OF THE COLD FRONT...WHICH WILL PUSH
THROUGH THE ENTIRE AREA BY 12Z MONDAY. KEEPING IN MIND THE LOW
CONFIDENCE IN TEMPS MENTIONED ABOVE...EXPECT HIGHS AND LOWS SATURDAY
AND SATURDAY NIGHT GENERALLY IN THE MID 40S NW TO MID 50S. THE
TEMPERATURES SHOULD GRADUALLY RISE OVERNIGHT SATURDAY TO UPPER 40S
NW TO LOW 60S SE BY 12Z SUNDAY...INCREASING FURTHER TO HIGHS AROUND
60 DEGREES NW TO AROUND 70 DEGREES SE ON SUNDAY. LOWS SUNDAY NIGHT
MAINLY IN THE MID 30S NW TO LOW 40S SE.
MONDAY THROUGH THURSDAY: EXPECT GENERALLY FAIR/DRY WEATHER TO RETURN
ON MONDAY BEHIND THE COLD FRONT...WITH AN ARCTIC HIGH RIDGING INTO
THE AREA AS THE CENTER OF THE HIGH MOVE EAST THROUGH THE VIRGINIAS.
EXPECT BELOW NORMAL TEMPERATURES GRADUALLY DECREASING FROM MONDAY...
MID 40S NW TO LOW 50S SE...TO THURSDAY...UPPER 30S NORTH TO AROUND
40 DEGREES SOUTH.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 1245 AM FRIDAY...
PRIMARY AVIATION CONCERN: A TREND TOWARD MVFR CIGS FROM SW TO NE
STARTING LATE THIS AFTERNOON.
LOW PRESSURE DEVELOPING JUST OFF THE TX GULF COAST HAS A WARM FRONT
EXTENDING EASTWARD ALONG THE GULF COAST. THIS LOW WILL STRENGTHEN
AND TRACK NE THROUGH THE LOWER MISS VALLEY TOWARD MICH TODAY AND
TONIGHT... AS THE WARM FRONT TRACKS NORTHWARD TOWARD NC. VFR CLOUDS
WILL CONTINUE TO SPREAD IN FROM THE WEST AND STEADILY THICKEN AND
LOWER OVER CENTRAL NC THROUGH TODAY... BUT CIGS ARE EXPECTED TO
REMAIN VFR THROUGH AT LEAST 20Z. CIGS SHOULD THEN SLOWLY LOWER TO
MVFR BETWEEN 21Z AND 00Z... FIRST AFFECTING INT/GSO/FAY THEN
RDU/RWI. MVFR CIGS SHOULD THEN DOMINATE AT ALL SITES AFTER 00Z
THROUGH THE END OF THE TAF VALID PERIOD... WITH PATCHY LIGHT RAIN
MOVING IN... ALTHOUGH VFR VSBYS SHOULD REMAIN DOMINANT INITIALLY.
WINDS WILL STAY LIGHT AND VARIABLE WITH SPEEDS MAINLY UNDER 5 KTS...
BECOMING PREDOMINANTLY FROM THE ENE AFTER 00Z.
LOOKING BEYOND 06Z EARLY SAT MORNING... HIGH CONFIDENCE THAT CIGS
WILL CONTINUE TO TREND DOWNWARD... TO IFR/LIFR OVERNIGHT AT ALL
SITES WITH RAIN BECOMING MORE WIDESPREAD YIELDING SUB-VFR VSBYS.
STARTING BY DAYBREAK SAT AND CONTINUING SAT THROUGH SAT NIGHT...
EXPECT IFR/LIFR CIGS AND MVFR/IFR VSBYS WITH PERIODS OF LIGHT RAIN
AND DRIZZLE AT ALL SITES. THE CRITERIA OF LOW LEVEL WIND SHEAR ARE
UNLIKELY TO BE MET INITIALLY... ALTHOUGH WE WILL STILL SEE
STRENGTHENING AND VEERING WINDS WITH HEIGHT LATE TONIGHT THROUGH
SAT. BY SUNSET SAT THE CHANCE OF LLWS WILL INCREASE AND REMAIN HIGH
THROUGH SAT NIGHT... UNTIL THE WARM FRONT TRACKS TO THE N OR NW
THROUGH THE AREA. SUB-VFR CIGS WILL HOLD INTO SUN... WITH A GOOD
CHANCE OF SHOWERS AND FEW STORMS AHEAD OF A COLD FRONT THAT WILL
SWEEP EAST THROUGH THE AREA SUN AFTERNOON/EVENING. VFR CONDITIONS
WILL RESUME POST-FRONT SUN NIGHT THROUGH TUE AS HIGH PRESSURE BUILDS
INTO THE AREA. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...BADGETT
SHORT TERM...BLAES
LONG TERM...KC
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION...UPDATED
NWS NASHVILLE TN
1152 PM CST THU JAN 1 2015
.UPDATE...FOR 06Z AVIATION DISCUSSION
&&
.AVIATION...
STILL A LOW CONFIDENCE FORECAST WITH RESPECT TO FLIGHT CATEGORIES
AND TIMING PRECIPITATION.
-SHRA OVER EASTERN ARKANSAS COULD IMPACT THE TERMINALS THROUGH 12Z
IF THEY HOLD TOGETHER, BUT THESE WILL BEST BE HANDLED WITH A
SHORT TEMPO GROUP IF IT APPEARS THEY`LL IMPACT A TERMINAL. BETTER
CHANCES FOR PERIODS OF -SHRA/-RA WILL OCCUR AFTER 13Z. CAN`T RULE
OUT A RUMBLE OF THUNDER OR TWO FRIDAY AFTERNOON/EVENING, BUT
CONFIDENCE OF OCCURRENCE IS TOO LOW TO MENTION AT THIS TIME.
HAVE MODERATE CONFIDENCE WITH RESPECT TO FLIGHT CATEGORIES, BUT LOW
CONFIDENCE WITH RESPECT TO TIMING THE CATEGORIES. A PERIOD OF LIFR
CONDITIONS WILL EVEN BE POSSIBLE AT ALL TERMINALS AFTER 22Z, BUT
CONFIDENCE IS CURRENTLY TOO LOW TO MENTION.
WE WERE SLIGHTLY CONCERNED WITH A SHORT PERIOD OF -FZRA AT KCKV
09Z-14Z, BUT CONFIDENCE IS INCREASING THAT THIS WILL LIKELY NOT
OCCUR. EVEN IF -FZRA DOES OCCUR, IT WILL BE FOR LESS THAN AN HOUR
AT MOST. HAVE HIGH CONFIDENCE THAT NO FROZEN PRECIPITATION WILL
OCCUR AT KBNA AND KCSV.
JACKSON
&&
.PREV DISCUSSION... /ISSUED 911 PM CST THU JAN 1 2015/
UPDATE...
IN LOOKING AT REGIONAL RADAR MOSIAC TRENDS...00Z KOHX SOUNDING PROFILE...
SHORT RANGE MODEL GUIDANCE...MODEL AND BUFKIT SOUNDINGS...AND SFC
OBS...LOOKS LIKE THE BEST CHANCE FOR RAINFALL WILL BE S OF THE MID
STATE REMAINDER OF EVENING AND OVERNIGHT WITH HIGHEST POPS FOR LOCATIONS
APPROACHING THE TN/KY BORDER AND FOR SRN LOCATIONS OF THE TN RIVER VALLEY
REGION OF W MID TN. BULK OF BEST POTENTIAL OF RAINFALL LOOKS TO MOVE
INTO AREA AT OR AROUND 08Z. THUS...IN GENERAL...HAVE BACKED OFF ON POPS
FROM SW TO NE ACROSS THE MID STATE THRU REMAINDER OF EVENING AND EVEN
INTO THE FIRST FEW OVERNIGHT HOURS...PUSHING BACK THE POTENTIAL FOR
MOST RAINFALL TO THE LATER PORTION OF THE EARLY MORNING HRS. WILL
CONTINUE TO MENTION THE POSSIBILITY OF A WINTRY MIX ACROSS NRN PORTIONS
OF MID STATE...HIGHLAND RIM AND NRN PORTIONS OF UPPER CUMBERLAND...TOWARD
THE LATER PORTION OF THE EARLY MORNING HRS TOO. HOWEVER...OVERALL CHANCES
OF WINTRY MIX DEVELOPING ACROSS THESE PORTIONS OF THE MID STATE DURING
THIS TIME PERIOD LOOK TO BE LESS LIKELY THAN PREVIOUSLY THOUGHT.
PREV DISCUSSION.../ISSUED 603 PM CST THU JAN 1 2015/
UPDATE...
UPDATED THE SUITE OF FORECAST PRODUCTS TO REMOVE THE THRU LATE AFTERNOON
GROUPING IN THE ZONE FORECAST PRODUCT. ADDITIONALLY...PER CURRENT RADAR
MOSAICS AND SHORT RANGE MODEL TRENDS...ONLY WENT GO WITH A SLIGHT CHANCE
OF RAIN ACROSS N CNTRL AND UPPER CUMBERLAND REGIONS ACROSS MID STATE
THRU EARLY EVENING HRS. MOST RECENT HRLY TEMP TRENDS ALSO SUPPORTING
RAISING OVERNIGHT LOWS INTO THE MID 30S ACROSS THE PLATEAU REGION.
OTHERWISE...CURRENT FORECAST AND BELOW FORECAST REASONING REMAINS ON TRACK.
PREV DISCUSSION.../ISSUED 554 PM CST THU JAN 1 2015/
UPDATE...FOR 00Z AVIATION DISCUSSION
AVIATION...
FOR THE 00Z TAFS, THERE IS LOW CONFIDENCE WITH RESPECT TO FLIGHT
CATEGORIES, PRECIPITATION TIMING, AND EVEN PRECIPITATION TYPE.
THE OVERALL TREND WILL BE FOR DETERIORATING CONDITIONS BEGINNING
OVERNIGHT.
WE DON`T THINK IT WILL RAIN THE ENTIRE TAF CYCLE, BUT PERIODS OF
LIGHT PRECIPITATION ARE EXPECTED.
HAVE MODERATE TO HIGH CONFIDENCE THAT -RA WILL BE THE
PRECIPITATION TYPE AT KBNA AND KCSV. AT KCKV, HOWEVER, CAN`T RULE
OUT A BRIEF PERIOD OF A -RA/-FZRA MIX, ESPECIALLY 08Z-14Z.
JACKSON
PREV DISCUSSION... /ISSUED 214 PM CST THU JAN 1 2015/
DISCUSSION...WEAK HIGH PRESSURE CONTINUES TO COVER MIDDLE
TENNESSEE EARLY THIS AFTERNOON WITH A VFR OVERCAST STRATOCU DECK
KEEPING A LID ON TEMPERATURES. RADAR MOSAIC SHOWS A LARGE AREA OF
MAINLY LIGHT RAIN OVER NORTHERN MS AND EXTREME SW TN, BUT GIVEN
LARGE DEW POINT SPREADS STILL IN PLACE ACROSS THE MID STATE, RAIN
WILL BE SLOW TO ARRIVE HERE. HRRR DOES SHOW SOME DEVELOPMENT
DURING THE EVENING AND OVERNIGHT, WITH MOST OF THE ACTIVITY
REMAINING IN THE RELATIVELY WARM AIR OF SOUTHERN MIDDLE TENNESSEE.
SCATTERED ACTIVITY MAY DEVELOP ACROSS OUR NORTH BEFORE 12Z, AND UP
AGAINST THE KY STATE LINE THIS PRECIPITATION MAY START OFF AS A
RA/FZRA OR RA/IP MIXTURE, BUT ACCUMULATIONS ARE NOT EXPECTED. IN
THE MEANTIME, A DEVELOPING LOW TO OUR SW WILL COME RACING NE`WD
INTO THE OZARKS BY 12Z SATURDAY, BRINGING A WARM FRONT NORTHWARD
ACROSS MIDDLE TENNESSEE SO THAT TEMPERATURES SATURDAY MAY WARM
INTO THE 60`S OFF THE PLATEAU. MODEL SOUNDINGS DO SHOW SOME
ELEVATED INSTABILITY WITH THIS SYSTEM, SO WILL INCLUDE TS IN THE
FORECAST FOR SATURDAY AND SATURDAY NIGHT. CAN`T COMPLETELY RULE
OUT A THUNDERSTORM OR TWO PRIOR TO 12Z SATURDAY, BUT THE BEST
INSTABILITY WON`T OCCUR UNTIL DURING THE DAY, SO WILL LIMIT TS TO
DAY 3 ONLY. SPC ALSO HAS US IN A GENERAL THUNDERSTORM AREA ON DAY
3, WITH FROPA OCCURRING BETWEEN 00Z AND 12Z SUNDAY. THERE WILL
LIKELY BE SOME LEFTOVER RAIN ON SUNDAY, BUT THEN LOOK FOR DRY
WEATHER FROM SUNDAY NIGHT AT LEAST THROUGH THURSDAY. TEMPERATURES
NEXT WEEK WILL REMAIN COLDER THAN NORMAL AS WE NEVER DO REALLY
ESTABLISH ANY MEANINGFUL RETURN FLOW, SO IT`S GOING TO A COLD
WEEK.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
JBW/JJ
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
1157 PM CST THU JAN 1 2015
.AVIATION...
/06Z TAFS/
ISENTROPIC LIFT WILL CONTINUE LATE THIS EVENING THROUGH FRIDAY
WITH IFR/LIFR CIGS/VBSYS CATEGORY PREVAILING FOR MOST OF THE
FORECAST CYCLE. LIGHT RAIN/DRIZZLE WILL CONTINUE TO AFFECT THE
I-35 SITES...ESPECIALLY THE AUSTIN AREA AIRPORTS AND KSAT. ANOTHER
AVIATION CONCERN FOR THIS PACKAGE WILL BE AREAS OF PATCHY TO DENSE
FOG DEVELOPING OVERNIGHT AND EARLY FRIDAY MORNING. SO FAR...HI-RES
MODELS SUGGEST AREAS OF DENSE FOG OVER PART OF THE ESCARPMENT AND
NORTHERN PART OF THE HILL COUNTRY AND JUST TO THE NORTHWEST OF
KAUS. HAVE ADDED A TEMPO GROUP TO KAUS SHOWING THE POTENTIAL OF
AREAS OF DENSE FOG ACROSS THE AIRPORT FROM 10Z TO 14Z FRIDAY.
FLYING CONDITIONS WILL NOT IMPROVE FROM THE LIFR CATEGORY UNTIL
LATE FRIDAY AFTERNOON WITH CIGS/VSBYS ONLY IMPROVING TO IFR FOR
COUPLE OF HOURS BEFORE DROPPING ONCE AGAIN INTO LIFR. THERE COULD
BE ISOLATED THUNDERSTORMS OUT WEST BY FRIDAY MORNING AND SHIFTING
EASTWARD DURING THE AFTERNOON HOURS. AT THIS TIME...OPTED TO KEEP
OUT MENTIONING TS AT TAF SITES DUE TO LOW CONFIDENCE ON TIMING AND
AERIAL COVERAGE.
&&
.PREV DISCUSSION... /ISSUED 934 PM CST THU JAN 1 2015/
UPDATE...INCREASED POPS ACROSS CENTRAL AND WESTERN ZONES FOR THE
OVERNIGHT THROUGH 6AM GIVEN RADAR TRENDS AND OBSERVATIONS INDICATING
THE LIGHT DRIZZLE REACHING THE SURFACE. ALSO INCREASED POPS BY ABOUT
10% FOR TOMORROW GIVEN HRRR/HI-RES OUTPUT. HOURLY TEMPERATURES AND
DEWPOINTS WERE MASSAGED TO ACCOUNT FOR CURRENT TRENDS. SEE UPDATED
DISCUSSION BELOW FOR MORE DETAILS.
DISCUSSION...AREAS OF FOG AND WIDESPREAD LIGHT RAIN SHOWERS AND DRIZZLE
IS ONGOING ACROSS MUCH OF THE REGION THIS EVENING. MOIST
ISENTROPIC UPGLIDE CONTINUES TO AID IN LIGHT PRECIPITATION
DEVELOPMENT AND THIS IS EXPECTED TO PERSIST THROUGH THE OVERNIGHT.
HAVE BUMPED UP POPS ACCORDINGLY AND ADDED A FEW HUNDREDTHS MORE TO
RAINFALL ACCUMULATION TOTALS. WHILE ALL AREAS ARE ABOVE
FREEZING...AREAS IN NORTHERN EDWARDS COUNTY ARE CLOSE TO THAT MARK
WITH ROCKSPRINGS AT 34 DEGREES AND SONORA AT 32 DEGREES. ALL SHORT
TERM GUIDANCE DOES KEEP AREA ABOVE FREEZING OVERNIGHT AND DONT
EXPECT ANY FREEZING RAIN ACROSS SOUTHERN EDWARDS PLATEAU IN THIS
PARTICULAR AREA.
FOR FRIDAY MORNING AND INTO THE AFTERNOON...HI-RES AND HRRR GUIDANCE
ARE INDICATING SLIGHTLY MORE ORGANIZED RAIN SHOWER BANDING AS
INCREASED LIFT OCCURS IN ADVANCE OF SHORTWAVE TROUGH PASSAGE. SOME
OF THIS BANDING COULD HAVE EMBEDDED THUNDERSTORM ACTIVITY GIVEN
SOME SUPPORT FROM NEAR 7C H7-H5 LAPSE RATES LEADING TO 300-600
J/KG MUCAPE PER EC AND NAM. HAVE INCREASED RAINFALL AMOUNTS
UPWARD ABOUT 0.05 TO 0.1" FOR THE SOUTHERN HILL COUNTRY AND JUST
NORTH AND WEST OF THE I-35 CORRIDOR IN THE 6AM TO NOON TIME FRAME.
A SMALL BREAK LOOKS TO OCCUR DURING THE AFTERNOON BEFORE ANOTHER
ROUND OF RAIN OCCURS OVERNIGHT FRIDAY INTO SATURDAY MORNING AS THE
MAIN TROUGH AXIS MOVES OVER THE AREA AND DRIER AIR MOVES IN.
/ALLEN/
PREV DISCUSSION... /ISSUED 554 PM CST THU JAN 1 2015/
AVIATION...
/00Z TAFS/
CIGS AND VBSYS WILL NOT IMPROVE MUCH THROUGH THE FORECAST PERIOD
WITH IFR/LIFR CONDITIONS. EXPECT LIGHT RAIN/DRIZZLE AND PATCHY FOG
ACROSS THE AREA AIRPORTS AS ISENTROPIC LIFT CONTINUES TO DOMINATE
ALOFT WITH A COOLER AIRMASS AT THE SURFACE. LOW LEVEL WINDS WILL
BE FROM THE NORTH AND NORTHEAST AND EVEN VARIABLE TONIGHT INTO
FRIDAY. THERE IS A SLIGHT CHANCE FOR ISOLATED THUNDERSTORMS ACROSS
SOUTH CENTRAL TEXAS ON FRIDAY AS AN UPPER LEVEL TROUGH PUSHES
ACROSS THE DESSERT SOUTHWEST INTO THE SOUTHERN PLAINS. HOWEVER...
AT THIS TIME...OPTED TO KEEP TS OUT. WILL REVISIT DURING THE 06Z
PACKAGE.
PREV DISCUSSION... /ISSUED 328 PM CST THU JAN 1 2015/
SHORT TERM (TONIGHT THROUGH FRIDAY NIGHT)...
WITH THE FREEZING LINE NOW JUST NORTH OF THE CWA...A EVENING AND
OVERNIGHT PERIOD OF COLD LIGHT RAIN...DRIZZLE...AND FOG ARE IN
STORE. WITH VISIBILITIES NEVER REACHING ABOVE 6 SM ACROSS THE
CWA...DIDNT THINK THEY WOULD IMPROVE ANY OVER THE NEXT 24 HOURS AS
THE SAME MOISTURE LOOKS TO BE IN PLACE UNTIL THE UPPER LEVEL
SYSTEM CLEARS OUT SUNDAY. THEREFORE INCLUDED AREAS OF FOG FOR THE
CWA THROUGH FRIDAY.
CONTINUAL OVERRUNNING AND THE SLOW EASTWARD TRANSLATION OF THE UPPER
LEVEL LOW WILL KEEP POP CHANCES HIGH FOR THE NORTH AND EAST ZONES
THROUGHOUT THE NEXT 24 HOURS. ELEVATED LAPSE RATES CONTINUED TO BE
STEEP AND WITH MORNING CONVECTION TODAY RESULTING IN SOME
LIGHTNING STRIKES...LEFT ISO T MENTION IN THE WX GRID THROUGH FRIDAY.
EVEN THOUGH RAIN WILL BE IN THE FORECAST THROUGH SATURDAY
MORNING...QPF VALUES SHOULD STAY BELOW CONCERNABLE VALUES DUE TO
THE FACT THE RAIN SHOULD STAY LIGHT. CURRENTLY...THE TOTAL QPF
FORECAST BETWEEN TONIGHT AND SATURDAY IS LESS THAN AN INCH ACROSS
THE CWA.
LONG TERM (SATURDAY THROUGH THURSDAY)...
THE UPPER LEVEL SYSTEM WILL FINALLY CLEAR OUT OF THE AREA SATURDAY
FROM THE WEST TO THE EAST. LATER IN THE EVENING...A STRONG BUT DRY
CP AIR MASS WILL DIVE SOUTH OUT OF THE PANHANDLE BRINGING GUSTY
WINDS SUNDAY DUE TO A RAPIDLY TIGHTENING PRESSURE GRADIENT...AND A
VERY COLD MORNING ON MONDAY. GUIDANCE IS CURRENTLY SUGGESTING
TEMPERATURES IN THE LOWER 20S IN THE NORTH AND AROUND 30 IN OUR
SOUTHERNMOST LOCATIONS SO IF THE FORECAST HOLDS...THE REMAINING
COUNTIES THAT HAVE NOT REACHED A WIDESPREAD FREEZE WILL DO SO COME
MONDAY.
THIS COOL PATTERN OF COLD MORNINGS AND COOL DAYS WILL PERSIST
THROUGH THE EXTENDED. A UPPER LEVEL RIDGE WILL MOVE OVER THE ROCKY
MOUNTAINS BY THURSDAY WHILE A WEAK DISTURBANCE FROM BAJA CREEPS
INTO THE SOUTHWEST. THIS MAY BRING SHOWER ACTIVITY BACK INTO THE
FORECAST TOWARDS THE END OF THE WEEK. MORE TO COME ON THIS AS
LATER MODEL RUNS PROVIDE MORE CLARITY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 37 42 40 59 36 / 80 90 90 20 10
AUSTIN BERGSTROM INTL AIRPORT 38 44 39 60 36 / 80 80 90 20 10
NEW BRAUNFELS MUNI AIRPORT 39 45 40 63 37 / 70 80 90 20 10
BURNET MUNI AIRPORT 35 40 35 57 32 / 80 80 90 20 10
DEL RIO INTL AIRPORT 37 49 40 63 37 / 60 60 60 - 0
GEORGETOWN MUNI AIRPORT 36 42 38 58 34 / 80 90 90 20 10
HONDO MUNI AIRPORT 38 47 39 63 35 / 60 70 70 10 10
SAN MARCOS MUNI AIRPORT 38 44 39 61 36 / 70 80 90 20 10
LA GRANGE - FAYETTE REGIONAL 41 47 44 60 38 / 80 80 90 40 10
SAN ANTONIO INTL AIRPORT 39 46 41 62 36 / 70 80 90 20 10
STINSON MUNI AIRPORT 40 46 40 63 37 / 70 70 80 20 10
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...17
SYNOPTIC/GRIDS...15
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
301 AM CST FRI JAN 2 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 301 AM CST FRI JAN 2 2015
CURRENTLY AS OF 09Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED A SHORTWAVE TROUGH OVER THE YUKON OF CANADA...A POTENT UPPER
TROUGH OVER NORTHERN BRITISH COLUMBIA...UPPER LOWS OVER ARIZONA AND
THE DENVER AREA...AND BROAD UPPER TROUGHING OVER EASTERN CANADA INTO
THE GREAT LAKES. WITH THE FORECAST AREA UNDER THE NORTHWEST FLOW ON
THE EDGE OF THIS UPPER TROUGHING...SUBSIDENCE AND DRYING HAS BEEN
OCCURRING. THIS HAS TRANSLATED INTO CLEARING SKIES IN THE WAKE OF A
SURFACE COLD FRONTAL PASSAGE DURING THE NIGHT. A BIT OF ARCTIC AIR
HAS BEEN SPILLING INTO NORTHERN WISCONSIN...NORTH OF HIGHWAY 29...
REFLECTED BY 925MB TEMPS DROPPING TO -12 TO -16C THERE AND SURFACE
TEMPERATURES IN THE SINGLE DIGITS ABOVE AND BELOW ZERO. READINGS ARE
MOSTLY IN THE TEENS ELSEWHERE IN THE FORECAST AREA. ONLY OTHER ITEM
OF NOTE WAS A LOOK AT PRECIPITABLE WATER VALUES FROM 00Z RAOBS. MOST
READINGS ACROSS THE CENTRAL/NORTHERN PLAINS AND OUR REGION WERE
BETWEEN 0.2 AND 0.35...FAIRLY DRY. HOWEVER...0.7-1 INCH VALUES WERE
PRESENT ACROSS THE SOUTHERN PLAINS AHEAD OF THE ARIZONA UPPER LOW.
MUCH OF THE SHORT TERM PERIOD IS QUIET THANKS TO THE DRY AIRMASS IN
PLACE REFLECTED BY 00Z RAOBS. HOWEVER...AS WE GET INTO THE AFTER
MIDNIGHT HOURS TONIGHT...THE 02.00Z GFS AND NAM SPREAD SOME LIGHT
QPF FROM THE SOUTH INTO CLAYTON/GRANT COUNTY AREA. THE 02.06Z
NAM/02.00Z ECMWF TAKE IT ONE STEP FURTHER AND SPREAD IT ALL THE WAY
THROUGH ABOUT THE EAST HALF OR MORE OF THE FORECAST AREA. MUCH OF
THIS QPF IS A RESULT OF AN ISENTROPIC LIFT / WARM ADVECTION REGIME
DEVELOPING DOWNSTREAM OF THE ARIZONA UPPER LOW...WHICH BY 12Z
SATURDAY IS PROGGED TO BE IN WEST TEXAS. ADDITIONALLY...WE HAVE THAT
UPPER LOW NEAR DENVER COMING THROUGH TO ADD IN SOME DPVA FORCING.
HAVE ADDED 20-40 PERCENT CHANCES INTO THE FORECAST FOR THIS FEATURE
AND THESE MAY NEED TO BE INCREASED LATER TODAY. MUCH OF THE LIFT IS
TAKING PLACE BETWEEN 10 KFT-15 KFT...BUT ENOUGH LOW LEVEL SATURATION
OCCURS TO ALLOW SNOW TO REACH THE SURFACE. IT SHOULD BE
NOTED...THOUGH...AS WE APPROACH 12Z THE ICE BEGINS TO EXITS THE
CLOUDS IN BOTH THE 02.00Z/06Z NAM AND GFS. SO...ANY LINGERING LIFT
APPROACHING THIS TIME COULD RESULT IN FREEZING DRIZZLE. HAVE ADDED
THIS POTENTIAL TO THE FORECAST. PROBABILITY FOR THIS FREEZING
DRIZZLE IS TOO LOW FOR AN ADVISORY AT THIS TIME.
WITH THE WARM ADVECTION REGIME DEVELOPING OVER THE NEXT 24 HOURS...
THE ARCTIC AIR TRYING TO SPILL INTO FAR NORTHERN SECTIONS OF THE
FORECAST AREA RIGHT NOW WILL STRUGGLE MAKING IT FARTHER SOUTH. IN
FACT...BY 00Z THIS EVENING...925MB TEMPS ALREADY ARE PROGGED FROM
-5C SOUTHWEST TO -9C NORTHEAST. WITH WHAT SHOULD BE A MOSTLY SUNNY
DAY...ANTICIPATE HIGHS CAN TOP OUT IN THE TEENS OVER TAYLOR/CLARK
COUNTIES TO THE 20S OVER THE REST OF THE SNOW PACK AREAS...AND LOW
30Z OVER SNOW FREE AREAS. WARM ADVECTION PERSISTS TONIGHT...WHICH
WITH CLOUDS INCREASING OVERNIGHT SHOULD HELP SOMEWHAT ON
TEMPERATURES. HOWEVER...WITH A MOSTLY CLEAR EVENING AND A WEAK
GRADIENT...READINGS COULD DROP INTO THE SINGLE DIGITS OVER
TAYLOR/CLARK TO THE TEENS TO LOW 20S ELSEWHERE.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 301 AM CST FRI JAN 2 2015
THE FOCUS FOR SATURDAY AND SATURDAY NIGHT CONTINUES TO REVOLVE
AROUND THE CURRENT UPPER LOW IN ARIZONA AND THE SHORTWAVE TROUGH
OVER BRITISH COLUMBIA. IT APPEARS THE MAIN ROLE OF THE BRITISH
COLUMBIA SHORTWAVE IS TO SERVE AS A KICKER FOR THE UPPER LOW. GOOD
MODEL CONSENSUS EXISTS FOR THE UPPER LOW TO TRACK THROUGH THE
DAVENPORT IA AREA AROUND 06Z SUNDAY AND INTO LOWER MICHIGAN BY 12Z
SUNDAY. HOWEVER...THE BRITISH COLUMBIA TROUGH DOES SPLIT APART WITH
A SHORTWAVE THAT COMES OFF IT WHICH MODELS BRING THROUGH THE
FORECAST AREA SATURDAY NIGHT. THAT SHORTWAVE EVENTUALLY PHASES WITH
THE UPPER LOW OVER LOWER MICHIGAN...RESULTING IN A DEEPENING SURFACE
LOW WELL OFF TO OUR EAST.
THE ISENTROPIC LIFT REGIME THAT DEVELOPED TONIGHT LOOKS TO PERSIST
THROUGH SATURDAY...THOUGH MAINLY FOCUSED OVER THE SOUTHEAST 1/3 TO
1/2 OF THE FORECAST AREA. THUS...THIS IS WHERE THE MAIN FOCUS FOR
PRECIPITATION EXISTS. AGAIN...BOTH THE 02.00Z NAM AND GFS POINT TO
WAVES OF ICE IN AND OUT OF THE CLOUDS...THUS THE FORECAST INCLUDES A
MENTION OF BOTH SNOW AND DRIZZLE/FREEZING DRIZZLE. WITH A GREATER
CHANCE FOR PRECIPITATION...MAY NEED AN ADVISORY FOR THIS WINTRY MIX
ASPECT. BEING DURING THE DAYTIME AND TEMPERATURES PERHAPS CLIMBING
ABOVE THE FREEZING MARK...THIS SHOULD HELP LIMIT ICE ACCUMULATION.
PRECIPITATION CHANCES INCREASE ACROSS THE ENTIRE FORECAST AREA
SATURDAY NIGHT WITH THE CROSSING OF THE SHORTWAVE AND BRUSH BY FROM
THE UPPER LOW. THE DEFORMATION SNOW BAND ACCOMPANYING THE NORTHWEST
SIDE OF THE DEEPENING SURFACE LOW MAY CLIP THE SOUTHEAST 1/3 OF THE
FORECAST AREA...THUS HIGHEST PRECIPITATION CHANCES AND QPF ARE
CONFINED THERE. PRECIPITATION SHOULD DIMINISH WEST TO EAST QUICKLY
LATE IN THE NIGHT AS SUBSIDENCE AND MUCH COLDER AND DRIER AIR ADVECT
IN. SNOWFALL AMOUNTS OVERALL HAVE COME DOWN QUITE A BIT WITH THE
02.00Z CYCLE...INCLUDING WITH THE 02.00Z ECMWF. THIS DECLINE IS A
COMBINATION OF THE AFOREMENTIONED WINTRY MIX AND MODELS NOT NEARLY
AS IMPRESSIVE WITH THE DEFORMATION BAND. IT SHOULD BE NOTED THAT THE
02.06Z NAM AND TO SOME DEGREE THE 02.00Z ECMWF HAVE THE DEFORMATION
BAND MISS MUCH OF THE FORECAST AREA...WITH MUCH OF THE PRECIP FOCUS
ON THE SNOW ACCOMPANYING THE SHORTWAVE. IF THIS HAPPENS...EVEN LESS
SNOW WILL FALL OVER THE SOUTHEAST 1/2 OF THE AREA.
FOCUS FOR THE REST OF THE FORECAST TURNS TO ARCTIC AIR. WE HAVE TWO
BIG BLASTS TO CONTEND WITH...THE FIRST COMING IN LATE SATURDAY NIGHT
AND THE SECOND COMING IN TUESDAY NIGHT. BOTH BLASTS HAVE A 35-45 KT
925MB WINDS CORE COMING ACROSS...WHICH MEANS THERE IS POTENTIAL WIND
SPEEDS COULD TRY TO APPROACH ADVISORY CRITERIA. HOWEVER...THE ARCTIC
AIR ACCOMPANYING THE WIND WILL FORCE WIND CHILL AS THE BIGGER
HAZARD. HOW COLD WE GET WILL DEPEND SOMEWHAT ON HOW MUCH SNOW WE GET
OVER THE NEXT FEW DAYS GIVEN THE LACK OF SNOW OVER THE SOUTHEAST
HALF OF THE FORECAST AREA. DETAILS...925MB TEMPS FALL FROM -4 TO -9C
AT 06Z SUNDAY TO -23 TO -26C BY 00Z MONDAY AND -26 TO -30C BY 12Z
MONDAY...WHICH MEANS TEMPERATURES SHOULD JUST FALL THROUGH THE DAY
SUNDAY...WITH MUCH OF THE NORTHWEST HALF BELOW ZERO FOR MUCH OF THE
DAY. WIND CHILL ADVISORIES LOOK LIKELY FOR THE NORTHWEST HALF ON
SUNDAY...EXPANDING EVERYWHERE SUNDAY NIGHT INTO MONDAY WITH MAYBE
SOME WARNINGS FOR TAYLOR/CLARK AND SOUTHEAST MN. THERE IS A BRIEF
WARM UP FOR MONDAY NIGHT INTO TUESDAY AS A NORTHWEST FLOW SHORTWAVE
TROUGH AND SYSTEM MOVE THROUGH THE REGION. PRECIPITATION CHANCES ARE
INCLUDED FOR THE SNOW ASPECT FOR THIS SYSTEM...WHICH COULD BE
ADVISORY WORTHY FOR SOME FLUFFY SNOW. THEN THE NEXT ARCTIC BLAST
FOLLOWS IN ITS WAKE FOR TUESDAY NIGHT AS A VERY DEEP TROUGH DROPS
INTO THE WESTERN GREAT LAKES. 925MB TEMPS PLUMMET FROM -14 TO -18C
AT 18Z TUESDAY TO AGAIN -26 TO -30C BY 12Z WEDNESDAY. WIND CHILL
ADVISORIES AND WARNINGS ARE LIKELY TO BE NEEDED. TEMPERATURES MAY
STRUGGLE TO CLIMB MUCH WEDNESDAY. LOWERED HIGHS SOME AND THESE MAY
NEED FURTHER LOWERING. ON A POSITIVE NOTE...MASSIVE WARM ADVECTION
IS PROGGED FOR WEDNESDAY NIGHT AND THURSDAY AS THE DEEP TROUGH MOVES
WELL OFF TO THE EAST. SO HIGHS SHOULD REBOUND NICELY FOR
THURSDAY...BUT STILL BELOW NORMAL.
INTERESTINGLY...THIS ARCTIC OUTBREAK FOR SUNDAY...MONDAY AND
WEDNESDAY ENDS UP BEING AT EXACTLY THE SAME TIME AS LAST YEARS
ARCTIC OUTBREAK. WIND CHILLS MAY NOT BE AS COLD...SINCE 925MB
TEMPS ARE A LITTLE WARMER THAN LAST YEARS ARCTIC OUTBREAK...BUT
ITS STILL LOOKS DANGEROUSLY COLD FOR SOME OF THIS TIME.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1113 PM CST THU JAN 1 2015
THE BAND OF MVFR/VFR CLOUDS HAS BEEN SLOWER THAN EXPECTED TO SLIP
SOUTH OF THE AREA...BUT THE BACK EDGE IS GETTING VERY CLOSE TO
BOTH TAF SITES AND EXPECTING THESE CLOUDS TO MOVE OUT OVERNIGHT.
AFTER THAT...VFR CONDITIONS AS HIGH PRESSURE SLIDES SOUTHEAST
ACROSS THE REGION WITH THE WINDS COMING AROUND TO THE SOUTH FRIDAY
MORNING. MOISTURE RETURNING TO THE AREA ON THE BACK SIDE OF THE
HIGH COULD RESULT IN THE DEVELOPMENT OF SOME MVFR CEILINGS...BUT
THIS IS NOT EXPECTED TO OCCUR UNTIL AFTER 03.06Z.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...04
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1157 PM MST THU JAN 1 2015
.UPDATE...
ISSUED AT 911 PM MST THU JAN 1 2015
SNOWING MORE STEADILY TO OUR SOUTH IN NORTHERN COLORADO BETWEEN
CHEYENNE AND FORT MORGAN ON THE NORTHERN SIDE OF A WEAK MIDLEVEL
CIRCULATION. THE SNOWBAND IS HAVING A REALLY HARD TIME WORKING
ITS WAY NORTH TO THE WYOMING BORDER GIVEN DEEPER DRY AIR OVER OUR
AREA. LATEST HRRR AND NAM MODELS INDICATING SOME ENHANCEMENT OF
LIGHT SNOW SHOWERS OVER OUR AREA AFTER MIDNIGHT...LASTING ONLY
THROUGH ABOUT 5 AM. THE LATEST NAM IS THE HEAVIEST WITH
ACCUMULATIONS INDICATING POSSIBLY A FEW INCHES OVER SOUTHEAST
WYOMING BY DAYBREAK...WITH THE HRRR SHOWING LESSER AMOUNTS. THE
LATEST 00Z GFS SHOWS LITTLE TO ANY QPF OR SNOWFALL ACCUMULATION
OVER OUR AREA KEEPING MOST IF ANY ACCUMULATION TO OUR SOUTH
THROUGH MORNING CLOSER TO THE MIDLEVEL CIRCULATION. WE ARE SEEING
SOME INCREASE IN LIGHT RADAR REFLECTIVITY AROUND WHEATLAND AND
CHUGWATER...BUT UNDERNEATH THE STRONGER RETURNS OF 15 TO 25 DBZ
SPOTTERS ARE CURRENTLY REPORTING NO SNOW FALLING. THERE MAY BE A
FEW FLURRIES OCCURRING RIGHT NOW ALONG I-25 BETWEEN CHEYENNE AND
CHUGWATER...BUT NOTHING SIGNIFICANT.
WE UPDATED ZONES TO INCLUDE ISOLATED LIGHT SNOW SHOWERS ACROSS
THE SOUTHEASTERN QUARTER OF OUR FORECAST AREA LATE TONIGHT WITH
LITTLE ADDITIONAL SNOW ACCUMULATION EXPECTED. IF THE NAM PANS OUT
TO BE MORE CORRECT (AND WE SUSPECT IT IS OVERDOING THE SNOWFALL
COVERAGE AND INTENSITY LATE TONIGHT)...THEN AN UPDATE TO INCREASE
COVERAGE MAY BE NECESSARY (WE WILL KEEP AN EYE ON IT). BOTTOM LINE
RIGHT NOW...WE THINK ANY ACCUMULATION WE GET ANYWHERE IN OUR AREA
TONIGHT WILL BE FAIRLY LIGHT (MOSTLY A VERY LIGHT DUSTING) IF ANY
BASED ON WHAT WE ARE SEEING AT THIS TIME. JG
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 300 PM MST THU JAN 1 2015
QUIET WEATHER THIS AFTERNOON BUT CLOUDS CONVERGING FROM NORTH AND
SOUTH AS THE CWA LIES BETWEEN TWO STREAMFLOWS. EXPECT CLOUDS TO
CONTINUE INCREASING OVER THE CWA THROUGH THIS EVENING. MEANWHILE
MODELS CONTINUE TO ADVERTISE A PIECE OF ENERGY BREAKING OFF FROM
THE UPPER LOW NEAR THE FOUR-CORNERS AREA AND DEVELOPING A SECOND
UPPER LOW OVER NORTHEAST COLORADO OVERNIGHT. VISIBLE SATELLITE
SEEMS TO HINT THAT THIS IS HAPPENING. WILL CONTINUE TO MENTION SOME
FLURRIES OVER PARTS OF THE CWA TONIGHT AS THE NEW UPPER LOW DRIFTS
SLOWLY NORTHEAST TONIGHT AND FRIDAY BUT DRY AIRMASS WILL LIMIT
SNOWFALL. TEMPS NOT AS COLD TONIGHT WITH MORE CLOUDCOVER. A QUIET
DAY FOR FRIDAY WITH A SHORT UPPER RIDGE PASSING BY.
ATTENTION WILL THEN TURN TO CLIPPER-LIKE SYSTEM THAT WILL MOVE
SOUTHEAST INTO THE NORTHERN HIGH PLAINS BY SAT MORNING WITH AN
ACCOMPANYING COLD FRONT THAT WILL THEN PASS ACROSS THE CWA SAT
MORNING. EXPECT TO SEE A PERIOD OF LIGHT SNOWS BEHIND THIS FRONT
GIVEN UPSLOPE FLOW AND SOME UPPER SUPPORT. DURATION OF SNOW NOT
LONG THUS AMOUNTS SHOULD STAY LIGHT. TEMPS LIKELY STEADY TO SLOWLY
FALLING SATURDAY AFTERNOON BEHIND THE FRONT WITH SNOW ENDING BY
EVENING EXCEPT OVER THE HIGHER MTNS WHERE SOME SNOW SHOWERS SHOULD
HANG ON THROUGH SAT NIGHT. DECENT MID-LEVEL WINDS SHOULD MIX DOWN
SATURDAY RESULTING IN QUITE BREEZY CONDITIONS OVER THE PLAINS.
.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 300 PM MST THU JAN 1 2015
SHORTWAVE IN NORTHWESTERLY FLOW ALOFT WILL SLIDE SOUTHEASTWARD FROM
MONTANA INTO THE DAKOTAS ON SUN. THIS WILL CAUSE A WEAK FRONT TO
BACK ACROSS AREAS TO THE EAST OF THE LARAMIE RANGE FOR A
CONTINUATION OF BELOW NORMAL TEMPS. WITH THE SFC TROUGH DRAPED
ACROSS THE ARLINGTON AREA...WILL SEE GUSTY WEST TO SOUTHWEST WINDS
FROM LARAMIE TO RAWLINS DURING THE AFTERNOON. THE 12Z ECMWF IS MORE
IN LINE WITH THE DRIER GFS BEHIND THE FROPA...HOWEVER STILL HAVE
SLIGHT CHANCE POPS OVER THE PLAINS THROUGH SUN NIGHT.
THE MODELS HAVE DELAYED THE INCREASE IN LLVL GRADIENT ACROSS
SOUTHEAST WY UNTIL MON. THE GFS SHOWS THE 850MB CAG-CPR GRADIENT
RISING TO 75-80 METERS BY MON AFTN WITH A SFC LOW OVER NORTHEAST WY.
IN ADDITION...SUBSIDENCE IN THE RIGHT EXIT REGION OF THE UPPER
JET MOVES OVERHEAD. THUS...IT LOOKS LIKE THE TIME PERIOD FROM
MIDDAY MON THROUGH MON NIGHT WILL BE FAVORED FOR HIGH WINDS IN THE
WIND PRONE AREAS AND PERHAPS SPREADING OVER PORTIONS OF THE
ADJACENT PLAINS IN SOUTHEAST WY. TEMPS WILL RISE AROUND 10 DEGREES
BUT STILL BE AVERAGE FOR EARLY JAN. WINDS WILL COME DOWN BY MON
NIGHT INTO TUES AS HIGHER PRESSURES MOVE INTO THE NORTHERN HIGH
PLAINS. TEMPS TRY TO MODERATE SOME BY TUES AND WED...MOST NOTABLY
OVER SOUTHEAST WY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1153 PM MST THU JAN 1 2015
VFR...WITH LOCALIZED MVFR IN SNOW SHOWERS THROUGH 12Z.
&&
.FIRE WEATHER...
ISSUED AT 300 PM MST THU JAN 1 2015
SEE NO REAL CONCERNS INTO AT LEAST EARLY NEXT WEEK WITH COOL
TEMPERATURES AND SNOW COVER. WINDS LOOK TO BECOME GUSTY OVER THE
PLAINS SATURDAY THEN BECOME GUSTY SUNDAY INTO MONDAY AROUND THE SE
WYOMING MTNS.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...JG
SHORT TERM...RE
LONG TERM...ZF
AVIATION...RUBIN
FIRE WEATHER...RE
AREA FORECAST DISCUSSION...UPDATED
NWS CHEYENNE WY
911 PM MST THU JAN 1 2015
.UPDATE...
ISSUED AT 911 PM MST THU JAN 1 2015
SNOWING MORE STEADILY TO OUR SOUTH IN NORTHERN COLORADO BETWEEN
CHEYENNE AND FORT MORGAN ON THE NORTHERN SIDE OF A WEAK MIDLEVEL
CIRCULATION. THE SNOWBAND IS HAVING A REALLY HARD TIME WORKING
ITS WAY NORTH TO THE WYOMING BORDER GIVEN DEEPER DRY AIR OVER OUR
AREA. LATEST HRRR AND NAM MODELS INDICATING SOME ENHANCEMENT OF
LIGHT SNOW SHOWERS OVER OUR AREA AFTER MIDNIGHT...LASTING ONLY
THROUGH ABOUT 5 AM. THE LATEST NAM IS THE HEAVIEST WITH
ACCUMULATIONS INDICATING POSSIBLY A FEW INCHES OVER SOUTHEAST
WYOMING BY DAYBREAK...WITH THE HRRR SHOWING LESSER AMOUNTS. THE
LATEST 00Z GFS SHOWS LITTLE TO ANY QPF OR SNOWFALL ACCUMULATION
OVER OUR AREA KEEPING MOST IF ANY ACCUMULATION TO OUR SOUTH
THROUGH MORNING CLOSER TO THE MIDLEVEL CIRCULATION. WE ARE SEEING
SOME INCREASE IN LIGHT RADAR REFLECTIVITY AROUND WHEATLAND AND
CHUGWATER...BUT UNDERNEATH THE STRONGER RETURNS OF 15 TO 25 DBZ
SPOTTERS ARE CURRENTLY REPORTING NO SNOW FALLING. THERE MAY BE A
FEW FLURRIES OCCURRING RIGHT NOW ALONG I-25 BETWEEN CHEYENNE AND
CHUGWATER...BUT NOTHING SIGNIFICANT.
WE UPDATED ZONES TO INCLUDE ISOLATED LIGHT SNOW SHOWERS ACROSS
THE SOUTHEASTERN QUARTER OF OUR FORECAST AREA LATE TONIGHT WITH
LITTLE ADDITIONAL SNOW ACCUMULATION EXPECTED. IF THE NAM PANS OUT
TO BE MORE CORRECT (AND WE SUSPECT IT IS OVERDOING THE SNOWFALL
COVERAGE AND INTENSITY LATE TONIGHT)...THEN AN UPDATE TO INCREASE
COVERAGE MAY BE NECESSARY (WE WILL KEEP AN EYE ON IT). BOTTOM LINE
RIGHT NOW...WE THINK ANY ACCUMULATION WE GET ANYWHERE IN OUR AREA
TONIGHT WILL BE FAIRLY LIGHT (MOSTLY A VERY LIGHT DUSTING) IF ANY
BASED ON WHAT WE ARE SEEING AT THIS TIME. JG
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 300 PM MST THU JAN 1 2015
QUIET WEATHER THIS AFTERNOON BUT CLOUDS CONVERGING FROM NORTH AND
SOUTH AS THE CWA LIES BETWEEN TWO STREAMFLOWS. EXPECT CLOUDS TO
CONTINUE INCREASING OVER THE CWA THROUGH THIS EVENING. MEANWHILE
MODELS CONTINUE TO ADVERTISE A PIECE OF ENERGY BREAKING OFF FROM
THE UPPER LOW NEAR THE FOUR-CORNERS AREA AND DEVELOPING A SECOND
UPPER LOW OVER NORTHEAST COLORADO OVERNIGHT. VISIBLE SATELLITE
SEEMS TO HINT THAT THIS IS HAPPENING. WILL CONTINUE TO MENTION SOME
FLURRIES OVER PARTS OF THE CWA TONIGHT AS THE NEW UPPER LOW DRIFTS
SLOWLY NORTHEAST TONIGHT AND FRIDAY BUT DRY AIRMASS WILL LIMIT
SNOWFALL. TEMPS NOT AS COLD TONIGHT WITH MORE CLOUDCOVER. A QUIET
DAY FOR FRIDAY WITH A SHORT UPPER RIDGE PASSING BY.
ATTENTION WILL THEN TURN TO CLIPPER-LIKE SYSTEM THAT WILL MOVE
SOUTHEAST INTO THE NORTHERN HIGH PLAINS BY SAT MORNING WITH AN
ACCOMPANYING COLD FRONT THAT WILL THEN PASS ACROSS THE CWA SAT
MORNING. EXPECT TO SEE A PERIOD OF LIGHT SNOWS BEHIND THIS FRONT
GIVEN UPSLOPE FLOW AND SOME UPPER SUPPORT. DURATION OF SNOW NOT
LONG THUS AMOUNTS SHOULD STAY LIGHT. TEMPS LIKELY STEADY TO SLOWLY
FALLING SATURDAY AFTERNOON BEHIND THE FRONT WITH SNOW ENDING BY
EVENING EXCEPT OVER THE HIGHER MTNS WHERE SOME SNOW SHOWERS SHOULD
HANG ON THROUGH SAT NIGHT. DECENT MID-LEVEL WINDS SHOULD MIX DOWN
SATURDAY RESULTING IN QUITE BREEZY CONDITIONS OVER THE PLAINS.
.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 300 PM MST THU JAN 1 2015
SHORTWAVE IN NORTHWESTERLY FLOW ALOFT WILL SLIDE SOUTHEASTWARD FROM
MONTANA INTO THE DAKOTAS ON SUN. THIS WILL CAUSE A WEAK FRONT TO
BACK ACROSS AREAS TO THE EAST OF THE LARAMIE RANGE FOR A
CONTINUATION OF BELOW NORMAL TEMPS. WITH THE SFC TROUGH DRAPED
ACROSS THE ARLINGTON AREA...WILL SEE GUSTY WEST TO SOUTHWEST WINDS
FROM LARAMIE TO RAWLINS DURING THE AFTERNOON. THE 12Z ECMWF IS MORE
IN LINE WITH THE DRIER GFS BEHIND THE FROPA...HOWEVER STILL HAVE
SLIGHT CHANCE POPS OVER THE PLAINS THROUGH SUN NIGHT.
THE MODELS HAVE DELAYED THE INCREASE IN LLVL GRADIENT ACROSS
SOUTHEAST WY UNTIL MON. THE GFS SHOWS THE 850MB CAG-CPR GRADIENT
RISING TO 75-80 METERS BY MON AFTN WITH A SFC LOW OVER NORTHEAST WY.
IN ADDITION...SUBSIDENCE IN THE RIGHT EXIT REGION OF THE UPPER
JET MOVES OVERHEAD. THUS...IT LOOKS LIKE THE TIME PERIOD FROM
MIDDAY MON THROUGH MON NIGHT WILL BE FAVORED FOR HIGH WINDS IN THE
WIND PRONE AREAS AND PERHAPS SPREADING OVER PORTIONS OF THE
ADJACENT PLAINS IN SOUTHEAST WY. TEMPS WILL RISE AROUND 10 DEGREES
BUT STILL BE AVERAGE FOR EARLY JAN. WINDS WILL COME DOWN BY MON
NIGHT INTO TUES AS HIGHER PRESSURES MOVE INTO THE NORTHERN HIGH
PLAINS. TEMPS TRY TO MODERATE SOME BY TUES AND WED...MOST NOTABLY
OVER SOUTHEAST WY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 427 PM MST THU JAN 1 2015
CLOUDS ARE INCREASING ACROSS MOST OF THE SITES WITH VFR CIGS GENERALLY
5-10 THOUSAND FEET AGL. MVFR CIGS WILL BE POSSIBLE AT LAR THROUGH
THE EARLY NIGHT. A BAND OF LIGHT SNOW SHOWERS IS CURRENTLY MOVING
ACROSS NORTHERN COLORADO. A FEW FLURRIES COULD BE POSSIBLE THROUGH
06Z AT CYS AND SNY...ALTHOUGH VIS SHOULD NOT DROP SIGNIFICANTLY.
WINDS THROUGH THE PERIOD WILL BE LESS THAN 15 KTS.
&&
.FIRE WEATHER...
ISSUED AT 300 PM MST THU JAN 1 2015
SEE NO REAL CONCERNS INTO AT LEAST EARLY NEXT WEEK WITH COOL
TEMPERATURES AND SNOW COVER. WINDS LOOK TO BECOME GUSTY OVER THE
PLAINS SATURDAY THEN BECOME GUSTY SUNDAY INTO MONDAY AROUND THE SE
WYOMING MTNS.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...JG
SHORT TERM...RE
LONG TERM...ZF
AVIATION...ZF
FIRE WEATHER...RE
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
734 AM MST FRI JAN 2 2015
.UPDATE...
ISSUED AT 734 AM MST FRI JAN 2 2015
CLOUD BAND NORTH OF I-70 IS BARELY MOVING AT THIS POINT SO ADDED
MORE CLOUDS TO THE MORNING FORECAST ESPECIALLY OVER THE NORTHERN
HALF OF THE FORECAST AREA. THERE SHOULD BE BREAKAGE BY MID DAY PER
LATEST RAP OUTPUT...BUT COULD LINGER OVER THE NORTHEAST CORNER
INTO THE AFTERNOON. ALSO ADDED A FEW SNOW SHOWERS NEAR THE WYOMING
BORDER PER LATEST OBS AND RADAR RETURNS.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 400 AM MST FRI JAN 2 2015
AN UPPER LOW JUST SOUTH OF THE FOUR CORNERS AND A SECONDARY UPPER
LOW OVER NORTHEAST COLORADO ARE CONNECTED BY AN ELONGATED UPPER
TROUGH. LOW CLOUDS AND POCKETS OF LIGHT SNOWFALL ACROSS NORTHERN
SECTIONS OF THE CWA COINCIDE WITH A +70KT JET MAXIMA ROUNDING THE
NORTHWEST SIDE OF THE UPPER LOW OVER NERN COLORADO. LOW IS EVIDENT
ON IR AND H20 VAPOR SATL IMAGERY. MODELS SHOW THIS NORTHERN LOW
AND ITS ACCOMPANYING CLOUD BAND AND LIGHT PRECIP TRACKING
NORTHEAST AWAY FROM THE FRONT RANGE AND ACROSS NEBRASKA THIS
MORNING. ONCE OUT OF THE AREA...SHOULD SEE CLEARING MOST AREAS AS
DRIER SLIGHTLY WARMER AIR ALOFT ADVECTS IN FROM THE NORTHWEST.
EXPECT HIGHS TODAY TO BE 8-12F WARMER THAN YESTERDAY.
TONIGHT...AFTER CLEAR SKIES AND LIGHT BREEZES IN THE
EVENING...MID AND HIGH CLOUDS ARE EXPECTED TO ENCROACH UPON THE
NRN MTN RANGES AFTER MIDNIGHT IN ADVANCE OF A CLIPPER WEATHER
SYSTEM RACING DOWN FROM BRITISH COLUMBIA. COULD POSSIBLY SEE A
LIGHT SNOW SHOWERS REACHING THE PARK AND GORE RANGES BEFORE
MORNING. IN ADDITION...STRENGTHENING NORTHWEST FLOW ALOFT WILL
CAUSE WLY WINDS TO INCREASE IN SPEED ON MTN RIDGES AND UPPER EAST
SLOPES OF THE FRONT RANGE AFTER MIDNIGHT. IN THESE AREAS COULD
SEE GUSTS IN THE 40-50 MPH RANGE. OTHERWISE IT WILL REMAIN DRY AT
LOWER ELEVATIONS.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 400 AM MST FRI JAN 2 2015
MAIN CONCERN WILL BE IMPACT FROM THE UPPER LEVEL TROF WHICH WILL
MOVE RAPIDLY FROM THE NORTHERN ROCKIES AND THROUGH COLORADO ON
SATURDAY. ASSOCIATED COLD FRONT WILL MOVE SOUTHWARD OVER THE
PLAINS MIDDAY ON SATURDAY WITH INCREASING NORTHERLY UPSLOPE FLOW
AND MOISTURE DURING THE AFTERNOON. MODEST QG UPWARD FORCING/JET
DYNAMICS AND RATHER STEEP LAPSE RATES WILL RESULT IN A WINDOW OF
SNOW SATURDAY AFTERNOON AND EVENING OVER MUCH OF CWA. GIVEN THE
STEEPENING LAPSE RATES AND INFLUX OF COLDER AIR...COULD SEE A FEW
HOURS OF MODERATE TO HEAVY SNOW OVER PORTIONS OF THE PLAINS.
LATEST GFS/NAM SHOWING 1-4 INCHES OF SNOW WHILE EUROPEAN A BIT
LESS WITH 1-2 INCHES. WITH MORE MODEL CONSISTENCY IN THE RUN TO
RUNS SHOWING UP IN THE PAST FEW DAYS...WILL BOOST POPS UP TO
LIKELY FOR MUCH OF THE AREA.
BEHIND THE DISTURBANCE...THE FLOW WILL INCREASE FROM THE
NORTHWEST WITH SOME DEVELOPMENT OF DOWNSLOPE WINDS OVER THE
MOUNTAINS AND EAST SLOPES FROM SUNDAY THROUGH TUESDAY. GUSTS IN
THE 50-70 MPH RANGE IS POSSIBLE SO WILL HAVE TO WATCH FOR
POTENTIAL FOR HIGH WINDS IN THESE PERIODS. WITH THE DOWNSLOPE
WINDS...TEMPERATURES WILL WARM TO SEASONAL NORMALS ACROSS LOWER
ELEVATIONS. LATEST LONG RANGE MODELS ARE NOW SHOWING ANOTHER
INFLUX OF COLDER AIR AND CHANCE OF PRECIP LATE TUESDAY AFTERNOON
AND NIGHT. WILL ADD SOME LOW POPS OVER THE FAR NORTHEAST CORNER IN
PROXIMITY TO THE UPPER JET. WITH THIS FLOW PATTERN...THE NORTHERN
MOUNTAINS WILL BE SUSCEPTIBLE TO A CHANCE OF LIGHT SNOW THROUGH
TUESDAY.
&&
.AVIATION...(FOR THE TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 400 AM MST FRI JAN 2 2015
5000-7000 FT AGL CIGS OVER DENVER AREA TERMINALS THROUGH 13Z...
THEN LOOK FOR CLEARING SKIES AS DRIER AIR SPREADS DOWN FROM THE
NORTHWEST. WEST-SOUTHWEST WINDS UNDER 10KTS FORECAST TO GO
SOUTHERLY AT SIMILAR SPEEDS BY MID-MORNING...THEN MORE
SOUTHEASTERLY BY EARLY AFTERNOON. WINDS AT KDEN...KAPA AND KBJC
ARE EXPECTED TO RETURN TO A SOUTH-SOUTHWEST DIRECTION AT 6-12KTS
AFTER 22Z AND REMAIN THERE OVERNIGHT UNDER CLEAR TO MOSTLY CLEAR
SKIES.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BARJENBRUCH
SHORT TERM...BAKER
LONG TERM...ENTREKIN
AVIATION...BAKER
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
839 AM EST FRI JAN 2 2015
.UPDATE...FORECAST AREA TO REMAIN IN MOIST LAYER BENEATH FRONTAL
INVERSION WITH WEAK ISENTROPIC LIFT SUPPORTING WIDESPREAD LOW
CLOUD COVER TODAY. MODELS SHOW LIFT BREAKING DOWN SOME TODAY...
PARTICULARLY SOUTHERN AREAS WHERE WE MIGHT SEE SOME BREAKS IN
CLOUDINESS AND HIGHER AFTERNOON TEMPS AS A RESULT...AS SUGGESTED
BY CONSENSUS GUIDANCE. SEE LITTLE IN WAY OF PRECIP POTENTIAL FOR
OUR AREA OF RESPONSIBILITY TODAY..THOUGH WE MAY SEE A FEW SHOWERS
OCCUR JUST NORTHWEST OF OUR GA COUNTIES THIS AFTERNOON...KEPT 10-20
POPS FOR OUR NORTHWESTERNMOST COUNTIES TODAY.
WILL MAINTAIN CURRENT HIGH TEMP FORECAST OF MID/UPR 60S I-10
CORRIDOR NORTHWARD...WITH MID 70S POSSIBLE MARION/FLAGLER COUNTIES.
&&
.AVIATION...IFR CIGS THIS MORNING. HRRR GUIDANCE SUGGESTS CIGS RISE
CLOSE TO BKN030 THIS AFTN...AND TAFS SHOW THIS TREND. EXPECT CIGS
TO LOWER TO IFR BY LATE TONIGHT.
&&
.MARINE...NO SIGNIFICANT CHANGES PLANNED IN CWF UPDATE.
A COASTAL TROUGH WILL MOVE NORTHEAST ACROSS THE COASTAL WATERS
THROUGH TONIGHT. HIGH PRESSURE WILL BUILD EAST OF AREA WATERS LATE
TONIGHT THROUGH SATURDAY NIGHT. A COLD FRONT WILL MOVE SOUTHEAST
ACROSS THE WATERS SUNDAY NIGHT. THIS BOUNDARY WILL STALL NEAR THE
REGION THROUGH TUESDAY. STRONG HIGH PRESSURE WILL BUILD NORTHWEST OF
THE REGION TOWARD MID WEEK...WHICH COULD LEAD TO ELEVATED WINDS AND
SEAS.
RIP CURRENTS: LOW RISK TODAY AND SATURDAY WITH 10KT NE WINDS AND
DECREASING HEIGHT/PERIOD OF EASTERLY SWELL.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 65 54 76 62 / 10 20 30 30
SSI 63 58 71 61 / 10 10 20 20
JAX 69 58 79 63 / 10 10 30 20
SGJ 70 62 78 66 / 10 10 30 20
GNV 72 58 81 62 / 10 10 30 20
OCF 75 61 83 65 / 10 10 20 20
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...NONE.
&&
$$
WOLF/ENYEDI/WALSH
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
633 AM EST FRI JAN 2 2015
.SYNOPSIS...
MOISTURE WILL INCREASE ACROSS THE AREA TODAY AS A LOW PRESSURE
SYSTEM AND COLD FRONT APPROACHES THE REGION FROM THE WEST. CHANCE
OF RAIN THROUGH THE WEEKEND. COLD HIGH PRESSURE AND DRY
CONDITIONS WILL BUILD BACK INTO THE REGION SUNDAY NIGHT AND MONDAY
THROUGH MID-WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SURFACE HIGH PRESSURE CONTINUES TO BUILD INTO THE REGION WHILE
THE WATER VAPOR IMAGERY SHOWS A DEEP UPPER LEVEL LOW OVER THE DESERT
SOUTHWEST WITH GENERALLY WEST- SOUTHWESTERLY FLOW ALOFT ACROSS THE
SOUTHERN PART OF THE COUNTRY. PATCHY LIGHT RAIN MOVED THROUGH THE
SOUTHERN PORTION OF THE CWA DURING THE OVERNIGHT. RADAR AT 10Z
INDICATING MORE RAIN UPSTREAM IN EASTERN ALABAMA AND WESTERN
GEORGIA. LATEST HRRR AND RAP MODELS SUGGEST THIS RAIN WILL MOVE
INTO SOUTH CAROLINA AND EAST CENTRAL GEORGIA THIS MORNING. RAIN
APPEARS TO BE ASSOCIATED WITH WEAK SHORT WAVE TROUGH EMBEDDED IN
WEST-SOUTHWEST UPPER LEVEL FLOW AND WEAK ISENTROPIC LIFT FOCUSED
IN THAT REGION AT THE MOMENT. BASED ON LATEST HRRR RUN WILL RAISE
POPS CSRA/WESTERN MIDLANDS/PIEDMONT THIS MORNING. PRECIPITABLE
WATER REMAINS LOW BUT WILL SLOWLY INCREASE THROUGH THE DAY.
RAINFALL AMOUNTS SHOULD BE LIGHT. IN-SITU WEDGE LIKELY TO DEVELOP
LEANED MORE TOWARD LOCAL WEDGE AND ECMWF OUTPUT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
WEDGE APPEARS TO STRENGTHEN TONIGHT WITH SURFACE RIDGE CENTER IN
FAVORABLE LOCATION IN THE NORTHEASTERN STATES EXTENDING SOUTHWEST
ACROSS THE CAROLINAS. CONFIDENCE HIGHER FOR COOL TEMPERATURES
SATURDAY. LITTLE CHANCE MADE TO TEMPERATURE FORECAST FROM
PREVIOUS FORECAST...SHOULD BE COOLER THAN TODAY AND LEANED TOWARD
LOCAL WEDGE TEMPERATURE OUTPUT/PREVIOUS FORECAST OVER MOS. CHANCE
OF RAIN/DRIZZLE HIGHER AS 850MB SOUTH FLOW INCREASES TO 20 TO 30
KTS BY AFTERNOON. ISENTROPIC LIFT 295K-300K SURFACE APPEARS
MODERATELY STRONG IN THE CENTRAL AND NORTH MIDLANDS/CSRA IN THE
AFTERNOON...SO PREFER HIGHER POP GUIDANCE...ALTHOUGH QPF LOW.
WEDGE CONTINUES ON SATURDAY SO TEMPS NEARLY STEADY BELOW
GUIDANCE. SATURDAY NIGHT THE COLD FRONT APPROACHES RAPIDLY FROM
THE WEST AND WARMER MOIST AIR STARTS TO PUSH NORTH AHEAD OF THE
FRONT. MIN TEMPS WILL LIKELY OCCUR EARLY WITH TEMPS RISING
OVERNIGHT ESPECIALLY IN THE SOUTHERN PART OF THE AREA. HAVE POPS
SATURDAY AND SATURDAY NIGHT IN THE 40 TO 60 PERCENT RANGE. RAIN
MAY FOCUS TO THE NORTH AND WEST SATURDAY NIGHT WHERE MOISTURE
DEEPER. WEDGE EXPECTED TO SLOWLY ERODE OVERNIGHT AS WARM FRONT
MOVES INTO THE AREA. TEMPERATURES EXPECTED TO REMAIN STEADY OR
RISE TOWARD SUNDAY MORNING.
THE BEST CHANCE FOR ACTIVE WEATHER WILL BE ON SUNDAY AS A SURFACE
LOW LIFTS NORTHWARD THROUGH THE OHIO RIVER VALLEY AND A COLD FRONT
MOVES EASTWARD TOWARDS THE REGION. MODELS IN GOOD AGREEMENT
BRINGING THE SURFACE FRONT THROUGH THE REGION DURING THE DAY ON
SUNDAY. WITH A STRONG LOW-LEVEL JET MOVING ALONG THE FRONT DURING
THE DAY...AND WITH SOME LIMITED INSTABILITY DURING THE
AFTERNOON...THERE IS SOME POTENTIAL FOR THUNDER. WITH MODEL LI/S
AROUND -1 TO -2 AND STRONG SHEAR...WILL MONITOR POTENTIAL FOR HIGH
SHEAR LOW CAPE CONVECTION AS THE FRONT PUSHES THROUGH.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
THE COLD FRONT WILL MOVE EAST OF THE FORECAST AREA SUNDAY
NIGHT...ALLOWING HIGH PRESSURE TO ONCE AGAIN BUILD BACK INTO THE
REGION FOR THE EARLY PART OF NEXT WEEK. MODELS BRING ANOTHER
STRONG ARCTIC HIGH DOWN INTO THE CENTRAL PLAINS BY THE MIDDLE OF
NEXT WEEK...WHICH WOULD BRING A DRY COLD FRONT INTO THE REGION
ALONG WITH COLDER TEMPERATURES. SO AT THIS TIME IT LOOKS TO BE DRY
FOR THE MONDAY THROUGH THURSDAY PERIOD WITH BELOW NORMAL
TEMPERATURES THROUGH THE PERIOD.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS STILL EXPECTED THROUGH MUCH OF THE PERIOD...WITH
POSSIBLE RETURN TO MVFR AFTER 06Z.
REGIONAL RADARS CONTINUE TO SHOW SHOWERS ASSOCIATED WITH WEAK
SHORTWAVE ENERGY MOVING ACROSS CENTRAL GA THIS MORNING. HRRR MODEL
INDICATES THIS ACTIVITY WILL HOLD TOGETHER AND MOVE INTO THE CSRA BY
13Z...THEN INTO THE CENTRAL MIDLANDS BY 14Z. THERE MAY BE SLIGHT
TIMING DIFFERENCES...BUT WILL GO WITH TEMPO GROUP IN THE CSRA
BEGINNING AT 13Z FOR -RA...THEN AT MIDLANDS SITES AT 14Z. GO
PREDOMINANT -RA AFTER THOSE TIMES....LASTING UNTIL EARLY AFTERNOON.
EXPECTING CONDITIONS TO REMAIN VFR THROUGH THE DAY...EVEN WITH THE
LIGHT RAIN. THE RAIN MAY LAST LONGER INTO THE AFTERNOON...BUT
CONFIDENCE NOT HIGH ENOUGH TO CONTINUE WITH RAIN IN THE TAFS AT THIS
TIME. SOME OF THE MODELS BEGIN INDICATING THAT MVFR CONDITIONS MAY
BE ABLE TO DEVELOP AFTER MIDNIGHT...WHILE OTHERS STILL SHOWING VFR.
HAVE TRENDED TOWARDS LOW END VFR CONDITIONS FOR THE OVERNIGHT
HOURS...BUT THIS MAY CONTINUE TO TREND DOWNWARD INTO MVFR WITH LATER
FORECAST UPDATES. EXPECT LIGHT AND VARIABLE WINDS THROUGH THE
PERIOD.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS FOR BOTH CEILINGS AND
VISIBILITIES WILL BE POSSIBLE SATURDAY AND SUNDAY AHEAD OF THE NEXT
STORM SYSTEM. THUNDERSTORMS MAY IMPACT TAF SITES ON SUNDAY JUST
AHEAD OF THE MAIN SURFACE COLD FRONT.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
514 AM EST FRI JAN 2 2015
.SYNOPSIS...
MOISTURE WILL INCREASE ACROSS THE AREA TODAY AS A LOW PRESSURE
SYSTEM AND COLD FRONT APPROACHES THE REGION FROM THE WEST. CHANCE
OF RAIN THROUGH THE WEEKEND. COLD HIGH PRESSURE AND DRY
CONDITIONS WILL BUILD BACK INTO THE REGION SUNDAY NIGHT AND MONDAY
THROUGH MID-WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SURFACE HIGH PRESSURE CONTINUES TO BUILD INTO THE REGION WHILE
THE WATER VAPOR IMAGERY SHOWS A DEEP UPPER LEVEL LOW OVER THE DESERT
SOUTHWEST WITH GENERALLY WEST- SOUTHWESTERLY FLOW ALOFT ACROSS THE
SOUTHERN PART OF THE COUNTRY. PATCHY LIGHT RAIN MOVED THROUGH THE
SOUTHERN PORTION OF THE CWA DURING THE OVERNIGHT. RADAR AT 10Z
INDICATING MORE RAIN UPSTREAM IN EASTERN ALABAMA AND WESTERN
GEORGIA. LATEST HRRR AND RAP MODELS SUGGEST THIS RAIN WILL MOVE
INTO SOUTH CAROLINA AND EAST CENTRAL GEORGIA THIS MORNING. RAIN
APPEARS TO BE ASSOCIATED WITH WEAK SHORT WAVE TROUGH EMBEDDED IN
WEST-SOUTHWEST UPPER LEVEL FLOW AND WEAK ISENTROPIC LIFT FOCUSED
IN THAT REGION AT THE MOMENT. BASED ON LATEST HRRR RUN WILL RAISE
POPS CSRA/WESTERN MIDLANDS/PIEDMONT THIS MORNING. PRECIPITABLE
WATER REMAINS LOW BUT WILL SLOWLY INCREASE THROUGH THE DAY.
RAINFALL AMOUNTS SHOULD BE LIGHT. IN-SITU WEDGE LIKELY TO DEVELOP
LEANED MORE TOWARD LOCAL WEDGE AND ECMWF OUTPUT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
WEDGE APPEARS TO STRENGTHEN TONIGHT WITH SURFACE RIDGE CENTER IN
FAVORABLE LOCATION IN THE NORTHEASTERN STATES EXTENDING SOUTHWEST
ACROSS THE CAROLINAS. CONFIDENCE HIGHER FOR COOL TEMPERATURES
SATURDAY. LITTLE CHANCE MADE TO TEMPERATURE FORECAST FROM
PREVIOUS FORECAST...SHOULD BE COOLER THAN TODAY AND LEANED TOWARD
LOCAL WEDGE TEMPERATURE OUTPUT/PREVIOUS FORECAST OVER MOS. CHANCE
OF RAIN/DRIZZLE HIGHER AS 850MB SOUTH FLOW INCREASES TO 20 TO 30
KTS BY AFTERNOON. ISENTROPIC LIFT 295K-300K SURFACE APPEARS
MODERATELY STRONG IN THE CENTRAL AND NORTH MIDLANDS/CSRA IN THE
AFTERNOON...SO PREFER HIGHER POP GUIDANCE...ALTHOUGH QPF LOW.
WEDGE CONTINUES ON SATURDAY SO TEMPS NEARLY STEADY BELOW
GUIDANCE. SATURDAY NIGHT THE COLD FRONT APPROACHES RAPIDLY FROM
THE WEST AND WARMER MOIST AIR STARTS TO PUSH NORTH AHEAD OF THE
FRONT. MIN TEMPS WILL LIKELY OCCUR EARLY WITH TEMPS RISING
OVERNIGHT ESPECIALLY IN THE SOUTHERN PART OF THE AREA. HAVE POPS
SATURDAY AND SATURDAY NIGHT IN THE 40 TO 60 PERCENT RANGE. RAIN
MAY FOCUS TO THE NORTH AND WEST SATURDAY NIGHT WHERE MOISTURE
DEEPER. WEDGE EXPECTED TO SLOWLY ERODE OVERNIGHT AS WARM FRONT
MOVES INTO THE AREA. TEMPERATURES EXPECTED TO REMAIN STEADY OR
RISE TOWARD SUNDAY MORNING.
THE BEST CHANCE FOR ACTIVE WEATHER WILL BE ON SUNDAY AS A SURFACE
LOW LIFTS NORTHWARD THROUGH THE OHIO RIVER VALLEY AND A COLD FRONT
MOVES EASTWARD TOWARDS THE REGION. MODELS IN GOOD AGREEMENT
BRINGING THE SURFACE FRONT THROUGH THE REGION DURING THE DAY ON
SUNDAY. WITH A STRONG LOW-LEVEL JET MOVING ALONG THE FRONT DURING
THE DAY...AND WITH SOME LIMITED INSTABILITY DURING THE
AFTERNOON...THERE IS SOME POTENTIAL FOR THUNDER. WITH MODEL LI/S
AROUND -1 TO -2 AND STRONG SHEAR...WILL MONITOR POTENTIAL FOR HIGH
SHEAR LOW CAPE CONVECTION AS THE FRONT PUSHES THROUGH.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
THE COLD FRONT WILL MOVE EAST OF THE FORECAST AREA SUNDAY
NIGHT...ALLOWING HIGH PRESSURE TO ONCE AGAIN BUILD BACK INTO THE
REGION FOR THE EARLY PART OF NEXT WEEK. MODELS BRING ANOTHER
STRONG ARCTIC HIGH DOWN INTO THE CENTRAL PLAINS BY THE MIDDLE OF
NEXT WEEK...WHICH WOULD BRING A DRY COLD FRONT INTO THE REGION
ALONG WITH COLDER TEMPERATURES. SO AT THIS TIME IT LOOKS TO BE DRY
FOR THE MONDAY THROUGH THURSDAY PERIOD WITH BELOW NORMAL
TEMPERATURES THROUGH THE PERIOD.
&&
.AVIATION /10Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS STILL EXPECTED THROUGH THE PERIOD.
REGIONAL RADARS SHOWING LIGHT RAINFALL MOVING EAST OF THE CSRA AND
CENTRAL MIDLANDS. SHOULD SEE A BREAK IN THE LIGHT RAIN OVER THE
NEXT SEVERAL HOURS. CEILINGS TO REMAIN VFR WITH HEIGHTS AROUND
10KFT. WITH PLENTY OF CLOUD COVER...DO NOT ANTICIPATE ANY FOG
FORMATION DURING THE MORNING. THROUGH THE DAY FRIDAY CEILINGS WILL
TREND SLOWLY DOWNWARD...BUT STILL REMAINING VFR. EXPECT LIGHT AND
VARIABLE WINDS THROUGH THE PERIOD. MAY SEE ADDITIONAL LIGHT
RAINFALL LATE IN THE DAYTIME PERIOD AND INTO PORTIONS OF THE
OVERNIGHT...HOWEVER TIMING AND LOW CONFIDENCE PRECLUDE MENTION IN
THE TAFS AT THIS TIME.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS FOR BOTH CEILINGS AND
VISIBILITIES WILL BE POSSIBLE LATE FRIDAY NIGHT AND THROUGH THE
WEEKEND WITH NEXT STORM SYSTEM APPROACHING.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
609 AM EST FRI JAN 2 2015
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 348 AM EST FRI JAN 2 2015
A LOW PRESSURE SYSTEM APPROACHING FROM THE PLAINS WILL BRING A
CHANCE FOR SOME LIGHT FREEZING RAIN AND RAIN TO THE AREA TONIGHT AND
MODERATE TO HEAVY RAIN AT TIMES ON SATURDAY. COULD SEE A CHANCE FOR
SNOW ON SUNDAY AS THE SYSTEM MOVES OUT AND COLDER AIR ARRIVES. A
CLIPPER SYSTEM WILL BRING LIGHT SNOW CHANCES MONDAY NIGHT THROUGH
TUESDAY AND COLDER AIR WILL SETTLE IN OVER THE AREA.
&&
.NEAR TERM /THIS MORNING AND TODAY/...
ISSUED AT 348 AM EST FRI JAN 2 2015
RADAR LOOP AND OBSERVATIONS ARE SHOWING SOME LIGHT SNOW AND RAIN
ACROSS SOUTHERN PORTIONS OF CENTRAL INDIANA. HRRR AND RAP SHOW THESE
LIGHT SHOWERS CONTINUING OFF AND ON THROUGH AROUND 12-15Z SO ADDED
SOME LOW CHANCE POPS INTO THE SOUTH TO COVER THESE FOR THE NEXT FEW
HOURS. COULD SEE SOME VERY LIGHT SLEET AS WELL IN THIS WINTRY
MIX...AND THIS COMBINATION COULD CAUSE SOME SLICK SPOTS ON UNTREATED
ROADS IN SOUTHERN PARTS OF CENTRAL INDIANA EARLY THIS MORNING.
AFTER THE AFOREMENTIONED SHOWERS MOVE OFF TO THE EAST SHOULD SEE DRY
CONDITIONS ACROSS THE AREA FOR THE REST OF THE DAY. CLOUDS WILL
CONTINUE TO STREAM IN FROM THE SOUTH OVERRUNNING THE WARM FRONT AND
THIS SHOULD KEEP TEMPERATURES FROM RISING TOO SIGNIFICANTLY TODAY.
SHOULD SEE HIGHS MAINLY IN THE 30S.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 348 AM EST FRI JAN 2 2015
FORECAST FOCUS IS ON PRECIP TIMING WITH WEEKEND SYSTEM AS WELL AS
PRECIP TYPE. MODELS ARE IN FAIRLY GOOD AGREEMENT AND WILL USE A
CONSENSUS APPROACH FOR THE MOST PART.
TO BEGIN THE TONIGHT PERIOD LOOKS LIKE A WARM FRONT WILL BE
APPROACHING FROM THE SOUTH AS A LOW PRESSURE SYSTEM PREPARES TO
TRAVEL THROUGH THE OHIO VALLEY FROM THE PLAINS. PRECIPITATION WILL
MOVE IN FROM THE SOUTHWEST. THIS SET OF MODEL RUNS IS FASTER WITH
THE APPROACH OF THE SYSTEM SO TRENDED THAT WAY AND BROUGHT IN POPS
AFTER 3Z. THICKNESSES AND SOUNDINGS INDICATE THE POTENTIAL FOR
FREEZING RAIN FOR A PERIOD AT ONSET...BUT THE WARM ADVECTION LOOKS
STOUT AND MODELS ARE ALL PROGGING SURFACE TEMPERATURES TO START
RISING BETWEEN 3 AND 9Z. WITH SURFACE TEMPERATURES POSSIBLY WARMING
ABOVE FREEZING DURING THE OVERNIGHT INCLUDED CHANCES FOR FREEZING
RAIN ALONG WITH THE RAIN BUT ELIMINATED THE FREEZING RAIN FROM SOUTH
TO NORTH STILL DURING THE TONIGHT PERIOD BASED ON HOURLY SURFACE
TEMPERATURES SURPASSING FREEZING. STILL MAINTAINED A CHANCE FOR
FREEZING RAIN IN THE NORTHERN COUNTIES FROM 12-15Z SATURDAY IN CASE
SURFACE TEMPERATURES DO NOT RISE AS QUICKLY AS ANTICIPATED.
SATURDAY STRONG ISENTROPIC LIFT ALONG WITH UPPER FORCING AND FORCING
FROM THE APPROACH AND PASSAGE OF THE SURFACE LOW WILL BRING RAIN TO
THE ENTIRE AREA. A STRONG LOW LEVEL JET WILL BRING AMPLE MOISTURE
UP AHEAD OF THE SYSTEM AND COULD SEE RAINFALL TOTALS IN EXCESS OF
1.5-2 INCHES IN SOME PLACES. RAIN SHOULD CONTINUE INTO SATURDAY
NIGHT AND COULD SEE SOME SNOW MIX IN LATE IN THE NORTHWEST.
UPPER SHORTWAVE WILL MOVE THROUGH THE AREA ON SUNDAY. ALTHOUGH THE
ATMOSPHERE SHOULD BE PRETTY DRY...WITH THE WAVE MOVING THROUGH ALONG
WITH MUCH COLDER AIR COMING INTO PLACE THING SEEING SOME SNOW IS NOT
OUT OF THE QUESTION. THUS WENT WITH CONSENSUS LOW CHANCE POPS IN THE
NORTHWEST CLOSER TO THE TRACK OF THE SHORTWAVE TAPERING TO SLIGHT
CHANCE IN THE SOUTHWEST. COLUMN SHOULD BE COOL ENOUGH FOR ANY PRECIP
SUNDAY TO FALL AS SNOW. BY SUNDAY NIGHT THE UPPER WAVE WILL BE
THROUGH AND SHOULD SEE DRY CONDITIONS. COLD ADVECTION ON DECENT
NORTHWESTERLY WINDS SHOULD ALLOW TEMPERATURES TO DROP BUT THE MIXING
FROM THE WIND SHOULD KEEP THEM FROM BOTTOMING OUT. THUS ACCEPTED THE
SLIGHTLY WARMER CONSENSUS NUMBERS WITH SINGLE DIGITS NORTHWEST TO
MID TEENS SOUTHEAST.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
ISSUED AT 348 AM EST FRI JAN 2 2015
APPEARS THE MAJORITY OF THE EXTENDED PERIOD WILL BE DRY...SAVE FOR
ONE QUICK CLIPPER SYSTEM SET TO IMPACT THE AREA MONDAY NIGHT THROUGH
TUESDAY. ANYWHERE FROM HALF AN INCH TO UPWARDS OF NEAR AN INCH OF
SNOW IS POSSIBLE AT THIS TIME...SO ACCUMULATIONS LOOK LIGHT AT THIS
TIME.
THE OTHER BIGGER STORY DURING THIS TIME IS POTENTIALLY THE
COLDEST AIR OF THE SEASON BEARING DOWN ON THE REGION AFTER THAT
CLIPPER SYSTEM EXITS THE REGION. BY TUESDAY NIGHT ALREADY LOOKING AT
SINGLE DIGIT TEMPS...SAME FOR WEDNESDAY NIGHT. THESE VERY COLD TEMPS
COMBINED WITH STRONG SURFACE N/NW FLOW WILL CREATE WIND CHILLS THAT
MAY APPROACH WIND CHILL ADVISORY CRITERIA AT TIMES TUESDAY NIGHT
THROUGH THURSDAY.
&&
.AVIATION /DISCUSSION FOR THE 021200Z TAF ISSUANCE/...
ISSUED AT 605 AM EST FRI JAN 2 2015
VFR EXPECTED AT LEAST THROUGH THE BULK OF THE DAY. AFTER 20Z AT
HUF AND BMG AND 00Z SAT AT IND...COULD SEE CONDITIONS DETERIORATE
TO MVFR OR WORSE AS CU EXPANDS NORTHWARD ACROSS THE TERMINALS IN
SOUTHERLY FLOW AHEAD OF A SOUTHERN SYSTEM. WINDS SHOULD BE
SOUTHWEST LESS THAN 10 KNOTS UNTIL AFTER 18Z WHEN WINDS WILL BACK
TO SOUTH AND THEN SOUTHEAST. THEN EITHER -FZRA OR A MIXTURE WITH
RAIN WILL MOVE INTO SOUTH CENTRAL INDIANA AFTER MIDNIGHT...MIX FOR
A FEW HOURS OVER ALL OF THE TAF SITES EARLY SATURDAY MORNING
BEFORE CHANGING OVER TO A MODERATE RAIN AND DROPPING TO IFR LATE
IN THE PERIOD. BEFORE THE DROP TO IFR...EXPECT MFVR CONDITIONS
BEFORE THE ARRIVAL OF PRECIP WITH LOW STRATO CU AND WITH THE -FZRA
MIX.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...CP
SHORT TERM...CP
LONG TERM....SMF
AVIATION...SMF
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS JACKSON KY
1012 AM EST FRI JAN 2 2015
.UPDATE...
ISSUED AT 1011 AM EST FRI JAN 2 2015
WENT AHEAD AND KEPT THE MENTION OF SLEET AND SNOW MIXING IN WITH RAIN
ACROSS THE NORTHERN PORTION OF THE CWA FOR THE NEXT COUPLE OF HOURS.
TEMPERATURES ARE STILL HOVERING IN THE 33 TO 35 DEGREE RANGE
HERE...BUT MOST OF THE AIR/MOISTURE ALOFT SHOULD STILL BE BELOW FREEZING.
ALSO BUMPED UP POPS IN THIS LOCATION FOR THE NEXT SEVERAL HOURS AS
WELL...AS ISOLATED TO SCATTERED LIGHT SHOWERS CONTINUE TO MOVE FROM
WEST TO EAST ACROSS NORTHERN KY. OTHER REFLECTIVITIES ARE CONTINUING
TO SHOW UP ACROSS THE WESTERN PORTION OF THE CWA MOVING EASTWARD AS
WELL. SO FAR...THE LATEST OBS ARE NOT SHOWING ANY OF THIS MOISTURE
ACTUALLY HITTING THE GROWN...BUT THOUGHT IT BEST TO GO AHEAD AND
INCLUDE THE MENTION OF SLIGHT CHANCES FOR PRECIP OVER THE NEXT FEW
HOURS ACROSS THE WESTERN CWA IN CASE SOMETHING IS ABLE TO WETBULB TO
THE SURFACE. ANY ICE POTENTIAL SHOULD BE OUT OF THE NORTHERN CWA BY
18Z THIS AFTERNOON AS TEMPERATURES CONTINUE TO SLOWLY RISE. THE NEXT
WAVE OF RAIN IS STILL EXPECTED TO ENTER INTO THE SOUTHERN CWA BY THIS
AFTERNOON.
UPDATE ISSUED AT 750 AM EST FRI JAN 2 2015
THE MORNING IS UNFOLDING MOSTLY AS EXPECTED...BUT THE LIGHT PCPN
NORTH OF THE MOUNTAIN PARKWAY IS MAKING ITS WAY TO THE SFC MORE
EFFECTIVELY THAN INITIALLY EXPECTED WHILE TO THE SOUTH THE INBOUND
PCPN HAS BEEN SLOWER TO ARRIVE. HAVE UPDATED THE NEXT SEVERAL HOURS
FOR THESE ADJUSTMENTS TAKING INTO ACCOUNT THE LATEST HRRR SCENARIO.
ALSO FINE TUNED THE T AND TD GRIDS PER THE LATEST OBS AND TRENDS.
THESE HAVE BEEN SENT TO THE NDFD AND WEB SERVERS.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 340 AM EST FRI JAN 2 2015
08Z SFC ANALYSIS SHOWS HIGH PRESSURE FADING OVER EASTERN KENTUCKY IN
ADVANCE OF A DEVELOPING WX SYSTEM TO THE SOUTHWEST AND AN AREA OF LOW
PRESSURE OFF TO THE NORTHEAST. THE CLOUDS ASSOCIATED WITH THE
SOUTHWEST SYSTEM HAVE OVERSPREAD THE AREA WITH POCKETS OF LIGHT PCPN
SHOWING UP ON THE REGIONAL RADAR...MAINLY SOUTH OF THE STATE
BORDER...THOUGH SOME RETURNS HAVE DEVELOPED ALONG INTERSTATE 64 IN
CENTRAL KENTUCKY...IN LINE WITH THE LATEST HRRR. THROUGH EAST
KENTUCKY TEMPERATURES ARE FAIRLY UNIFORM IN THE MID 30S WHILE
DEWPOINTS ARE GENERALLY IN THE MID 20S. DEW POINT DEPRESSIONS ON THE
ORDER OF 10 DEGREES WILL LEAD TO A CONCERN FOR WETBULBING WITH ANY
EARLY PCPN THIS MORNING THAT SHOULD RESULT IN PATCHES OF SLEET ALONG
WITH THE LIGHT RAIN. WILL CONTINUE TO DEPICT THIS IN THE GRIDS AND
MENTION IT IN THE HWO AND ZONES...THOUGH ANY IMPACTS ARE EXPECTED TO
BE MINIMAL GIVEN PAVEMENT TEMPERATURES ABOVE FREEZING THROUGH THE
EASTERN PARTS OF THE STATE. WINDS REMAIN LIGHT FROM THE SOUTHWEST
THROUGH THE AREA EARLY THIS MORNING.
THE MODELS ARE IN GOOD AGREEMENT ALOFT FOR THE SHORT TERM PORTION OF
THE FORECAST AS THEY ALL SHOW THE SOUTHWESTERN CLOSED LOW GETTING
PARTIALLY PICKED UP BY THE NORTHERN STREAM LATER TODAY. THIS PROCESS
RELEASES A BATCH OF ENERGY AND LOWER HEIGHTS INTO THE CENTRAL PLAINS
BY EVENING WHILE A LARGER PORTION STAYS SEPARATE OVER SOUTHERN NEW
MEXICO. THE EXPELLED NORTHERN WAVE IS QUICKLY ABSORBED INTO THE
LARGER FLOW AND SPREAD OVER THE CENTRAL GREAT LAKES BY MIDDAY
SATURDAY WHILE THE MAIN LOW IS KICKED EAST BY SOME ENERGY RIDING INTO
ITS BACKSIDE LATER SATURDAY. AHEAD OF THESE WAVES...BROAD SOUTHWEST
FLOW WILL SEND WARMER AND MORE MOIST AIR INTO THE TENNESSEE AND OHIO
VALLEYS TODAY THROUGH SATURDAY. GIVEN THE MODEL AGREEMENT HAVE
FOLLOWED THE HIGHER RESOLUTION NAM12 AND HRRR MOST CLOSELY.
SENSIBLE WEATHER WILL FEATURE THE NET RESULT OF A MOISTENING
ENVIRONMENT AND A DEVELOPING SFC LOW TO THE SOUTHWEST...RAIN CHANCES
MOVING IN FROM SOUTHWEST TO NORTHEAST TODAY. THE BETTER CHANCES
ARRIVE AFTER 18Z FOR THE BULK OF THE JKL CWA ALLOWING THE WARMER AIR
TO BRING UP TEMPERATURES WHILE DEWPOINTS CLIMB ABOVE FREEZING MAKING
ALL THE PCPN LIQUID AFTER THE EARLY MORNING POCKETS OF LIGHT MIXED
PCPN. THE REAL SURGE OF SHOWERS WILL ARRIVE LATER TONIGHT AS A
DEVELOPING WARM FRONT LIFTS INTO THE AREA AND PROVIDES A GOOD
FOCUSING MECHANISM FOR THE INCREASINGLY MOIST AIR. BY DAWN SATURDAY
THE DEEPENING SFC LOW OVER THE LOWER MISSISSIPPI VALLEY WILL LIFT ITS
WARM FRONT NORTH OF THE AREA PLACING OUR AREA IN THE WARM SECTOR OF A
RAPIDLY DEVELOPING SYSTEM TO THE WEST. AS A RESULT...WINDS WILL
INCREASE STEADILY DURING THE DAY SATURDAY WITH ENOUGH INSTABILITY
AVAILABLE FOR A RISK OF THUNDER ACROSS THE ENTIRE AREA...POSSIBLY
ARRIVING BEFORE DAWN SATURDAY PER THE LATEST SWODY1. A BREEZY AND
MILD DAY ENSUES AHEAD OF THE SYSTEM/S COLD FRONT LATER SATURDAY WITH
DRY WEATHER EXPECTED FOR A GOOD PORTION OF THE TIME...THOUGH SOME
SCATTERED SHOWERS AND POSSIBLE THUNDERSTORMS WILL BE AROUND EASTERN
KENTUCKY INTO SATURDAY EVENING. WILL HIT THE THUNDER CHANCES AND THE
BREEZY CONDITIONS HARDER IN THE HWO TO BE ISSUED LATER THIS MORNING.
USED THE BCCONSSHORT AS A STARTING POINT FOR TEMPS...TD...AND WINDS
THROUGH 21Z FRIDAY AND THEN THE SUPERBLEND THROUGH 00Z SUNDAY. ONLY
SLIGHTLY TWEAKED POINT TEMPERATURE DATA FOR MAXES AND MINS. AS FOR
POPS...FAVORED A BLEND OF THE HRRR AND NAM12 EARLY THEN MAINLY THE
NAM12 THROUGH TONIGHT AND SATURDAY. ON THE WHOLE...ENDED UP SIMILAR
TO THE MOS BLEND WITH POPS THROUGH THE SHORT TERM...BUT DETAILS WHERE
ADDED TO SHOW SOME BREAKS WITHIN THE WARM SECTOR DRY SLOTTING
EXPECTED ON SATURDAY.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 357 AM EST FRI JAN 2 2015
THE EXTENDED FORECAST PERIOD BEGINS ON SATURDAY NIGHT WITH AN
AMPLIFIED UPPER LEVEL PATTERN OVER THE CONUS. A LARGE LONGWAVE
TROUGH MOVES THROUGH THE CENTRAL PAINS AND INTO THE MS RIVER VALLEY.
AT THIS TIME A POTENT SHORT WAVE IS LIFTING OUT OF THE MID MS RIVER
VALLEY AND MOVING INTO THE OH VALLEY...WHILE A SECOND STRONG
SHORTWAVE DEVELOPS ALONG THE LOWER PORTION OF THE MS VALLEY AND
QUICK LIFTS NORTHEAST AS WELL INTO THE LOWER APPALACHIAN RANGE. A
STRONG JET DEVELOPING IN THE UPPER LEVELS ON SUNDAY NIGHT OVER THE
MID ATLANTIC WILL LIFT THE UPPER LEVEL TROUGH NORTHEAST INTO THE NEW
ENGLAND AREA. THIS SETS THE PATTERN FROM MONDAY THROUGH THURSDAY OF
A SEMI PERMANENT UPPER LEVEL LONGWAVE TROUGH OVER THE GREAT LAKES
AND NEW ENGLAND AREA. THIS CYCLONIC FLOW OVER THE NORTHEASTERN CONUS
WILL LEAD TO NORTHWEST FLOW FOR EASTERN KENTUCKY THROUGH THE REST OF
THE EXTENDED.
CLOSER TO THE SURFACE FOR THE FRONT MOVING THROUGH SAT NIGHT THROUGH
SUNDAY NIGHT...THE INHERITED FORECAST AND RESULT OF THE BLEND OF
MODELS LEAVES QUITE A BIT OF PRECIP MOVING THROUGH SAT NIGHT THROUGH
SUNDAY. PWATS DURING THIS TIME WITH MODEL SOUNDINGS SHOW 1.34 INCHES
WHICH IS AMPLE THIS TIME OF YEAR. HPC RESULTS ALONG WITH THE MODEL
BLEND PUT AROUND AN INCH IN THE AREA FOR THE STA NIGHT AND SUNDAY
TIME FRAME AND HAVE GONE WITH THESE VALUES AS THOUGH...WEAKENING THE
SHOWERS WITH THE FRONT MOVING THROUGH COULD PRODUCE SOME DECENT
RAINFALL AT TIMES. AS MENTIONED WITH THE LOW SHOWING A WEAKENING
TREND...THERE IS A DECENT AMOUNT OF ISENTROPIC LIFT AHEAD AND WITH
THIS FRONT AND WITH THE INHERITED FORECAST COUPLED WITH A CONSENSUS
OF NEIGHBORING OFFICES...DECIDED TO KEEP A SLIGHT CHANCE OF THUNDER
IN THE SATURDAY NIGHT PORTION. AS MENTIONED WITH THE PROGRESSIVE
FLOW AND QUICK EXIT OF THIS FEATURE...PRECIP HANGING UP ON THE
EASTERN RIDGES SHOULD BE SHORT IN DURATION AND HAVE ALL POPS
EXITING EARLY SUNDAY NIGHT. AS SUCH...THE MOISTURE WILL EXIT THE
AREA BEFORE ANY COLD AIR FILTERS IN. ANY CHANGE OVER TO SNOW ACROSS
THE AREA IS NOT EXPECTED.
THE DRIER NORTHWEST FLOW SETTING UP BY TUESDAY WILL HINDER PRECIP
MAKING IT FAR ENOUGH SOUTH INTO EASTERN KENTUCKY FOR SNOWFALL. BASED
ON INHERITED FORECAST...PATTERN RECOGNITION AND COLLABORATION WITH
THE NEIGHBORING OFFICES...HAVE GONE DRY WITH THE WEAK SHORTWAVE
MOVING THROUGH THE OH VALLEY TUESDAY NIGHT INTO WEDNESDAY. WHILE A
FEW FLURRIES ARE POSSIBLE AS WELL...THE GENERAL TREND WITH THIS IS
THAT AS MOISTURE STARVED AS THESE CLIPPER SYSTEMS ARE...THE BULK OF
THE UPPER LEVEL SUPPORT STAYS TO THE NORTH WITH THIS WAVE. AFTER
SUNDAY NIGHT...HAVE GONE DRY OVER EASTERN KENTUCKY FOR THE REST OF
THE FORECAST. THE DEW POINTS WITH THIS ARCTIC AIR MASS MOVING IN
DURING THE LAST PART OF THE EXTENDED IS QUITE IMPRESSIVE. QUITE A
COLD AND DRY AIR MASS MAKES ITS PRESENCE KNOWN DIVING SOUTH INTO THE
CENTRAL CONUS AND MEANDERING SOUTHEAST BY THE END OF THE EXTENDED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 715 AM EST FRI JAN 2 2015
CIGS HAVE FALLEN TO MVFR IN THE SOUTHERN PARTS OF THE AREA UP TO JKL
AND NOW SJS. THESE WILL STAY LOW THROUGH THE REMAINDER OF THE TAF
PERIOD AS THE LOW LEVELS OF THE ATMOSPHERE FURTHER SATURATE. LIGHT
PCPN WILL AFFECT THE AREA THIS MORNING...FALLING MOSTLY AS RAIN...
HOWEVER SOME SLEET WILL BE POSSIBLE AT THE ONSET. EXPECT MVFR CLOUDS
TO OVERTAKE THE REST OF THE AREA FROM SOUTH TO NORTH THROUGH THE
MORNING...WITH LOCATIONS NORTH OF THE I-64 CORRIDOR LIKELY STAYING
LOW VFR UNTIL THIS AFTERNOON WHEN A DEVELOPING WARM FRONT LIFTS INTO
THIS PART OF KENTUCKY FROM THE SOUTH. LOWER CIGS IN THE IFR OR LIFR
RANGE ARE EXPECTED TONIGHT ALONG WITH RAIN AND BR LEADING TO VIS
RESTRICTIONS. SOUTHWEST WINDS OF 5 TO 10 KTS CAN BE EXPECTED THROUGH
THE DAY WITH AN INCREASE IN SPEEDS JUST OFF THE SFC TONIGHT FROM THE
SOUTHWEST. HAVE ADDED LLWS FOR THIS AT UP TO 35 KTS AT 1500 FEET TO
ALL THE TAFS STARTING AT EARLY AS 6Z.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JMW
SHORT TERM...GREIF
LONG TERM...SHALLENBERGER
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
750 AM EST FRI JAN 2 2015
.UPDATE...
ISSUED AT 750 AM EST FRI JAN 2 2015
THE MORNING IS UNFOLDING MOSTLY AS EXPECTED...BUT THE LIGHT PCPN
NORTH OF THE MOUNTAIN PARKWAY IS MAKING ITS WAY TO THE SFC MORE
EFFECTIVELY THAN INITIALLY EXPECTED WHILE TO THE SOUTH THE INBOUND
PCPN HAS BEEN SLOWER TO ARRIVE. HAVE UPDATED THE NEXT SEVERAL HOURS
FOR THESE ADJUSTMENTS TAKING INTO ACCOUNT THE LATEST HRRR SCENARIO.
ALSO FINE TUNED THE T AND TD GRIDS PER THE LATEST OBS AND TRENDS.
THESE HAVE BEEN SENT TO THE NDFD AND WEB SERVERS.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 340 AM EST FRI JAN 2 2015
08Z SFC ANALYSIS SHOWS HIGH PRESSURE FADING OVER EASTERN KENTUCKY IN
ADVANCE OF A DEVELOPING WX SYSTEM TO THE SOUTHWEST AND AN AREA OF LOW
PRESSURE OFF TO THE NORTHEAST. THE CLOUDS ASSOCIATED WITH THE
SOUTHWEST SYSTEM HAVE OVERSPREAD THE AREA WITH POCKETS OF LIGHT PCPN
SHOWING UP ON THE REGIONAL RADAR...MAINLY SOUTH OF THE STATE
BORDER...THOUGH SOME RETURNS HAVE DEVELOPED ALONG INTERSTATE 64 IN
CENTRAL KENTUCKY...IN LINE WITH THE LATEST HRRR. THROUGH EAST
KENTUCKY TEMPERATURES ARE FAIRLY UNIFORM IN THE MID 30S WHILE
DEWPOINTS ARE GENERALLY IN THE MID 20S. DEW POINT DEPRESSIONS ON THE
ORDER OF 10 DEGREES WILL LEAD TO A CONCERN FOR WETBULBING WITH ANY
EARLY PCPN THIS MORNING THAT SHOULD RESULT IN PATCHES OF SLEET ALONG
WITH THE LIGHT RAIN. WILL CONTINUE TO DEPICT THIS IN THE GRIDS AND
MENTION IT IN THE HWO AND ZONES...THOUGH ANY IMPACTS ARE EXPECTED TO
BE MINIMAL GIVEN PAVEMENT TEMPERATURES ABOVE FREEZING THROUGH THE
EASTERN PARTS OF THE STATE. WINDS REMAIN LIGHT FROM THE SOUTHWEST
THROUGH THE AREA EARLY THIS MORNING.
THE MODELS ARE IN GOOD AGREEMENT ALOFT FOR THE SHORT TERM PORTION OF
THE FORECAST AS THEY ALL SHOW THE SOUTHWESTERN CLOSED LOW GETTING
PARTIALLY PICKED UP BY THE NORTHERN STREAM LATER TODAY. THIS PROCESS
RELEASES A BATCH OF ENERGY AND LOWER HEIGHTS INTO THE CENTRAL PLAINS
BY EVENING WHILE A LARGER PORTION STAYS SEPARATE OVER SOUTHERN NEW
MEXICO. THE EXPELLED NORTHERN WAVE IS QUICKLY ABSORBED INTO THE
LARGER FLOW AND SPREAD OVER THE CENTRAL GREAT LAKES BY MIDDAY
SATURDAY WHILE THE MAIN LOW IS KICKED EAST BY SOME ENERGY RIDING INTO
ITS BACKSIDE LATER SATURDAY. AHEAD OF THESE WAVES...BROAD SOUTHWEST
FLOW WILL SEND WARMER AND MORE MOIST AIR INTO THE TENNESSEE AND OHIO
VALLEYS TODAY THROUGH SATURDAY. GIVEN THE MODEL AGREEMENT HAVE
FOLLOWED THE HIGHER RESOLUTION NAM12 AND HRRR MOST CLOSELY.
SENSIBLE WEATHER WILL FEATURE THE NET RESULT OF A MOISTENING
ENVIRONMENT AND A DEVELOPING SFC LOW TO THE SOUTHWEST...RAIN CHANCES
MOVING IN FROM SOUTHWEST TO NORTHEAST TODAY. THE BETTER CHANCES
ARRIVE AFTER 18Z FOR THE BULK OF THE JKL CWA ALLOWING THE WARMER AIR
TO BRING UP TEMPERATURES WHILE DEWPOINTS CLIMB ABOVE FREEZING MAKING
ALL THE PCPN LIQUID AFTER THE EARLY MORNING POCKETS OF LIGHT MIXED
PCPN. THE REAL SURGE OF SHOWERS WILL ARRIVE LATER TONIGHT AS A
DEVELOPING WARM FRONT LIFTS INTO THE AREA AND PROVIDES A GOOD
FOCUSING MECHANISM FOR THE INCREASINGLY MOIST AIR. BY DAWN SATURDAY
THE DEEPENING SFC LOW OVER THE LOWER MISSISSIPPI VALLEY WILL LIFT ITS
WARM FRONT NORTH OF THE AREA PLACING OUR AREA IN THE WARM SECTOR OF A
RAPIDLY DEVELOPING SYSTEM TO THE WEST. AS A RESULT...WINDS WILL
INCREASE STEADILY DURING THE DAY SATURDAY WITH ENOUGH INSTABILITY
AVAILABLE FOR A RISK OF THUNDER ACROSS THE ENTIRE AREA...POSSIBLY
ARRIVING BEFORE DAWN SATURDAY PER THE LATEST SWODY1. A BREEZY AND
MILD DAY ENSUES AHEAD OF THE SYSTEM/S COLD FRONT LATER SATURDAY WITH
DRY WEATHER EXPECTED FOR A GOOD PORTION OF THE TIME...THOUGH SOME
SCATTERED SHOWERS AND POSSIBLE THUNDERSTORMS WILL BE AROUND EASTERN
KENTUCKY INTO SATURDAY EVENING. WILL HIT THE THUNDER CHANCES AND THE
BREEZY CONDITIONS HARDER IN THE HWO TO BE ISSUED LATER THIS MORNING.
USED THE BCCONSSHORT AS A STARTING POINT FOR TEMPS...TD...AND WINDS
THROUGH 21Z FRIDAY AND THEN THE SUPERBLEND THROUGH 00Z SUNDAY. ONLY
SLIGHTLY TWEAKED POINT TEMPERATURE DATA FOR MAXES AND MINS. AS FOR
POPS...FAVORED A BLEND OF THE HRRR AND NAM12 EARLY THEN MAINLY THE
NAM12 THROUGH TONIGHT AND SATURDAY. ON THE WHOLE...ENDED UP SIMILAR
TO THE MOS BLEND WITH POPS THROUGH THE SHORT TERM...BUT DETAILS WHERE
ADDED TO SHOW SOME BREAKS WITHIN THE WARM SECTOR DRY SLOTTING
EXPECTED ON SATURDAY.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 357 AM EST FRI JAN 2 2015
THE EXTENDED FORECAST PERIOD BEGINS ON SATURDAY NIGHT WITH AN
AMPLIFIED UPPER LEVEL PATTERN OVER THE CONUS. A LARGE LONGWAVE
TROUGH MOVES THROUGH THE CENTRAL PAINS AND INTO THE MS RIVER VALLEY.
AT THIS TIME A POTENT SHORT WAVE IS LIFTING OUT OF THE MID MS RIVER
VALLEY AND MOVING INTO THE OH VALLEY...WHILE A SECOND STRONG
SHORTWAVE DEVELOPS ALONG THE LOWER PORTION OF THE MS VALLEY AND
QUICK LIFTS NORTHEAST AS WELL INTO THE LOWER APPALACHIAN RANGE. A
STRONG JET DEVELOPING IN THE UPPER LEVELS ON SUNDAY NIGHT OVER THE
MID ATLANTIC WILL LIFT THE UPPER LEVEL TROUGH NORTHEAST INTO THE NEW
ENGLAND AREA. THIS SETS THE PATTERN FROM MONDAY THROUGH THURSDAY OF
A SEMI PERMANENT UPPER LEVEL LONGWAVE TROUGH OVER THE GREAT LAKES
AND NEW ENGLAND AREA. THIS CYCLONIC FLOW OVER THE NORTHEASTERN CONUS
WILL LEAD TO NORTHWEST FLOW FOR EASTERN KENTUCKY THROUGH THE REST OF
THE EXTENDED.
CLOSER TO THE SURFACE FOR THE FRONT MOVING THROUGH SAT NIGHT THROUGH
SUNDAY NIGHT...THE INHERITED FORECAST AND RESULT OF THE BLEND OF
MODELS LEAVES QUITE A BIT OF PRECIP MOVING THROUGH SAT NIGHT THROUGH
SUNDAY. PWATS DURING THIS TIME WITH MODEL SOUNDINGS SHOW 1.34 INCHES
WHICH IS AMPLE THIS TIME OF YEAR. HPC RESULTS ALONG WITH THE MODEL
BLEND PUT AROUND AN INCH IN THE AREA FOR THE STA NIGHT AND SUNDAY
TIME FRAME AND HAVE GONE WITH THESE VALUES AS THOUGH...WEAKENING THE
SHOWERS WITH THE FRONT MOVING THROUGH COULD PRODUCE SOME DECENT
RAINFALL AT TIMES. AS MENTIONED WITH THE LOW SHOWING A WEAKENING
TREND...THERE IS A DECENT AMOUNT OF ISENTROPIC LIFT AHEAD AND WITH
THIS FRONT AND WITH THE INHERITED FORECAST COUPLED WITH A CONSENSUS
OF NEIGHBORING OFFICES...DECIDED TO KEEP A SLIGHT CHANCE OF THUNDER
IN THE SATURDAY NIGHT PORTION. AS MENTIONED WITH THE PROGRESSIVE
FLOW AND QUICK EXIT OF THIS FEATURE...PRECIP HANGING UP ON THE
EASTERN RIDGES SHOULD BE SHORT IN DURATION AND HAVE ALL POPS
EXITING EARLY SUNDAY NIGHT. AS SUCH...THE MOISTURE WILL EXIT THE
AREA BEFORE ANY COLD AIR FILTERS IN. ANY CHANGE OVER TO SNOW ACROSS
THE AREA IS NOT EXPECTED.
THE DRIER NORTHWEST FLOW SETTING UP BY TUESDAY WILL HINDER PRECIP
MAKING IT FAR ENOUGH SOUTH INTO EASTERN KENTUCKY FOR SNOWFALL. BASED
ON INHERITED FORECAST...PATTERN RECOGNITION AND COLLABORATION WITH
THE NEIGHBORING OFFICES...HAVE GONE DRY WITH THE WEAK SHORTWAVE
MOVING THROUGH THE OH VALLEY TUESDAY NIGHT INTO WEDNESDAY. WHILE A
FEW FLURRIES ARE POSSIBLE AS WELL...THE GENERAL TREND WITH THIS IS
THAT AS MOISTURE STARVED AS THESE CLIPPER SYSTEMS ARE...THE BULK OF
THE UPPER LEVEL SUPPORT STAYS TO THE NORTH WITH THIS WAVE. AFTER
SUNDAY NIGHT...HAVE GONE DRY OVER EASTERN KENTUCKY FOR THE REST OF
THE FORECAST. THE DEW POINTS WITH THIS ARCTIC AIR MASS MOVING IN
DURING THE LAST PART OF THE EXTENDED IS QUITE IMPRESSIVE. QUITE A
COLD AND DRY AIR MASS MAKES ITS PRESENCE KNOWN DIVING SOUTH INTO THE
CENTRAL CONUS AND MEANDERING SOUTHEAST BY THE END OF THE EXTENDED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 715 AM EST FRI JAN 2 2015
CIGS HAVE FALLEN TO MVFR IN THE SOUTHERN PARTS OF THE AREA UP TO JKL
AND NOW SJS. THESE WILL STAY LOW THROUGH THE REMAINDER OF THE TAF
PERIOD AS THE LOW LEVELS OF THE ATMOSPHERE FURTHER SATURATE. LIGHT
PCPN WILL AFFECT THE AREA THIS MORNING...FALLING MOSTLY AS RAIN...
HOWEVER SOME SLEET WILL BE POSSIBLE AT THE ONSET. EXPECT MVFR CLOUDS
TO OVERTAKE THE REST OF THE AREA FROM SOUTH TO NORTH THROUGH THE
MORNING...WITH LOCATIONS NORTH OF THE I-64 CORRIDOR LIKELY STAYING
LOW VFR UNTIL THIS AFTERNOON WHEN A DEVELOPING WARM FRONT LIFTS INTO
THIS PART OF KENTUCKY FROM THE SOUTH. LOWER CIGS IN THE IFR OR LIFR
RANGE ARE EXPECTED TONIGHT ALONG WITH RAIN AND BR LEADING TO VIS
RESTRICTIONS. SOUTHWEST WINDS OF 5 TO 10 KTS CAN BE EXPECTED THROUGH
THE DAY WITH AN INCREASE IN SPEEDS JUST OFF THE SFC TONIGHT FROM THE
SOUTHWEST. HAVE ADDED LLWS FOR THIS AT UP TO 35 KTS AT 1500 FEET TO
ALL THE TAFS STARTING AT EARLY AS 6Z.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...GREIF
LONG TERM...SHALLENBERGER
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS CARIBOU ME
917 AM EST FRI JAN 2 2015
.SYNOPSIS...
AN ARCTIC FRONT WILL SWEEP ACROSS THE REGION THIS AFTERNOON. HIGH
PRESSURE WILL BUILD INTO THE AREA TONIGHT THROUGH SATURDAY. LOW
PRESSURE TRACKING NORTHWEST OF MAINE WILL ALLOW A WARM FRONT TO
APPROACH THE REGION SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
915 AM UPDATE...WE`RE CONTINUING TO SEE SCATTERED SHOWERS ACROSS
OUR NORTHERN AREAS THIS MORNING. SOME OF THESE SHOWERS ARE BRIEFLY
HEAVY AND COULD REDUCE VISIBILITY SHARPLY AT TIMES. THIS ACTIVITY
WILL SHIFT INTO NEW BRUNSWICK THROUGH THE MORNING HOURS. IN THE
MEANTIME, A COLD FRONT LIES POISED ON OUR WESTERN BORDER.
TEMPERATURES ARE MUCH COLDER ON THE BACK SIDE OF THIS FRONT, WITH
MANY STATIONS IN SOUTHERN QUEBEC IN THE SINGLE DIGITS AT THIS
HOUR. EXPECT TEMPERATURES IN NORTHERN MAINE TO HOLD STEADY OR
PERHAPS RISE A DEGREE OR TWO OVER THE NEXT HOUR OR SO, BUT THEN
TEMPERATURES WILL DROP QUICKLY AS THE FRONT PASSES THROUGH THE
AREA. SOUTHERN MAINE WILL HAVE MORE OF A CHANCE OF WARMING A BIT
MORE BEFORE THE FRONT COMES THROUGH. WINDS WILL SWITCH TO THE
WEST NORTHWEST BEHIND THE FRONT AS WELL, WHICH WILL ALLOW FOR SOME
STREAMERS TO COME OFF THE SAINT LAWRENCE RIVER. AS SUCH, SNOW
SHOWERS WILL CONTINUE TO BE POSSIBLE OVER THE NORTHERN PORTIONS OF
THE COUNTY THROUGH THE AFTERNOON HOURS. HAVE MADE SOME SLIGHT
ADJUSTMENTS TO POPS, TEMPS, AND WINDS TO MATCH CURRENT
OBSERVATIONS AND RADAR IMAGERY. NO OTHER CHANGES WERE NEEDED.
PREVIOUS DISCUSSION...THE NAM AND LATEST HRRR 3KM WERE DOING
QUITE WELL W/THE CURRENT SETUP. THINKING HERE IS THAT THE FIRST
BATCH OF SNOW SHOWERS OCCURRING ATTM WILL MOVE ACROSS THE REGION
W/THE BEST ENHANCEMENT FROM MT. KATAHDIN TO THE SHERMAN-PATTEN
REGION AS UP TO AN INCH OR SNOW COULD ACCUMULATE. ANOTHER BATCH OF
SNOW SHOWERS AND A FEW SQUALLS LOOK LIKE THEY WILL SET UP BETWEEN
7 AM AND 10 AM THIS MORNING W/THE ARCTIC FRONT APPROACHING. THE
NAM SOUNDING SUPPORTS 850-700MBS LAPSE RATES AROUND 7.0 C/KM W/A
FCST CAPE IN THE RANGE OF 75-100 JOULES. THIS IS WHERE IS SOME
AREAS COULD PICK UP ANOTHER INCH OF SNOW W/SOME GUSTY WINDS.
FURTHER SOUTH FROM THE CENTRAL HIGHLANDS DOWN TO INTO TEH DOWNEAST
REGION, MAINLY MOSTLY CLOUDY W/A FEW FLURRIES. THINGS WIND DOWN
NEAR OR AFTER 18Z. TEMPERATURES LOOK LIKE THEY COULD ACTUALLY
CLIMB SOME THIS MORNING AHEAD OF THE FRONT AND THEN FALL BACK
SHARPLY THIS AFTERNOON INTO THE EVENING. ADJUSTMENTS WERE NEEDED
TO THE MAXES TODAY TO BRING THEM UP AND SHOW AN EARLY DAYTIME HIGH
TEMP. CLOUDS SHOULD BREAK UP THIS AFTERNOON AS THE LATEST IR
SATELLITE IMAGERY SHOWS THAT CLEARING BACK ACROSS QUEBEC AND THIS
IS SUPPORTED BY THE NAM GUIDANCE. WINDS WILL ALSO PICK UP FOR A
TIME AS THE FRONT MOVES IN.
THE CHALLENGE TONIGHT WILL BE HOW SOON THE REGION CLEARS OUT AND
HOW QUICKLY THE WINDS DROP OFF W/HIGH PRES MOVING RAPIDLY INTO
THE REGION OVERNIGHT. ANOTHER FACTOR WILL BE THE WNW FLOW COMING
OFF THE OPEN ST. LAWRENCE AS THIS AIRMASS IS QUITE COLD. SOUNDINGS
SHOW THE COLUMN TO DRY OUT THROUGH 500MBS W/THE EXCEPTION OF THE
CROWN OF MAINE AS SOME MOISTURE STAYS TRAPPED BETWEEN 925-850MBS.
DECIDED TO HANG ON TO SOME CLOUDS ACROSS THE CROWN AND WENT
W/CLEARING FOR THE REST OF THE CWA. SOMETIMES W/A SCENARIO LIKE
THIS ONE, LIGHT SNOW COULD SET UP, BUT SINCE THE AIRMASS LOOKS BE
DRY ABOVE 850MBS OVER THE CROWN, DECIDED TO STAY AWAY FROM ANY
MENTION OF LIGHT SNOW ATTM. STAYED CLOSE TO THE DAYCREW`S THINKING
OF OVERNIGHT LOWS DROPPING TO 10-15 BELOW ACROSS THE NORTH AND
CENTRAL AREAS W/SINGLE NUMBERS FOR THE DOWNEAST REGION INCLUDING
THE COAST. IF THE WINDS DROP OFF SOONER, THEN TEMPERATURES COULD
BE EVEN COLDER BY 7 AM SATURDAY. THIS CAN BE ASSESSED FURTHER BY
THE ONCOMING DAYCREW.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
SATURDAY IS SHAPING UP AS THE BETTER OF THE TWO WEEKEND DAYS AS
LONG AS YOU DONT MIND THE COLD. EXPECT PLENTY OF SUN TO START AS
HIGH PRESSURE MOVES ACROSS THE REGION. HIGH CLOUDS WILL BEGIN TO
INCREASE BY AFTERNOON. HIGH TEMPERATURES ON SATURDAY WILL ONLY
RANGE FROM THE SINGLE DIGITS TO AROUND 10 ABOVE NORTH AND CENTRAL
AREAS WITH MID TO UPPER TEENS DOWN EAST.
CLOUDS WILL CONTINUE TO INCREASE AND THICKEN SATURDAY EVENING IN
ADVANCE OF LOW PRESSURE APPROACHING FROM THE WEST. EXPECT
PRECIPITATION IN THE FORM OF SNOW TO DEVELOP FROM SOUTHWEST TO
NORTHEAST BY OR SHORTLY AFTER MIDNIGHT. WARMER AIR MOVING IN ALOFT
WILL RESULT IN THE PRECIPITATION MIXING WITH SLEET AND FREEZING
RAIN ACROSS DOWN EAST AREAS BY LATE SATURDAY NIGHT BUT THE
PRECIPITATION WILL REMAIN IN THE FORM OF ALL SNOW ACROSS NORTHERN
AND CENTRAL AREAS THROUGH THE NIGHT SATURDAY WITH SEVERAL INCHES
OF SNOW POSSIBLE BY DAYBREAK SUNDAY. LOW TEMPERATURES WILL OCCUR
EARLY IN THE EVENING SATURDAY BEFORE SLOWLY RISING OVERNIGHT.
PRECIPITATION WILL BE ONGOING FIRST THING SUNDAY AS LOW PRESSURE
CONTINUES TO TRACK TO OUR NORTHWEST. MODELS CONTINUE TO HINT AT A
WEAK TRIPLE POINT LOW FORMING ALONG THE MAINE COAST DURING SUNDAY.
AS THE PRIMARY LOW CONTINUES TO TRACK TO OUR NORTHWEST ON SUNDAY
WARMER AIR ALOFT WILL CONTINUE TO BRING MILDER AIR ALOFT WITH
PRECIPITATION CHANGE TO SLEET AND FREEZING RAIN ACROSS NORTHERN
AND CENTRAL AREAS AND EVEN ALL RAIN ACROSS DOWN EAST ESPECIALLY
THE COAST. RIGHT NOW IT APPEARS AS IF MOST AREAS WILL SEE SNOW
TOTAL RANGING FROM 3 TO 6 INCHES BEFORE THE CHANGEOVER OCCURS ON
SUNDAY. ICE ACCUMULATIONS ARE EXPECTED TO RANGE FROM ABOUT A
TENTH OF AN INCH CENTRAL AND DOWN EAST AND LESS THAN A TENTH OF AN
INCH ACROSS NORTHERN AREAS. SINCE THIS IS STILL A LATE FOURTH INTO
FIFTH PERIOD EVENT WONT BE ISSUING ANY HEADLINES YET BUT A THIS
TIME IT LOOKS LIKE WINTER WEATHER ADVISORIES WILL PROBABLY BE
NEEDED FOR JUST ABOUT ALL AREAS OF OUR CWA FOR SATURDAY NIGHT AND
SUNDAY FOR THE COMBINATION OF SNOW AND MIXED PRECIPITATION. THE
STEADY PRECIPITATION IS EXPECTED TO WIND DOWN ACROSS THE AREA AS
THE LOW CONTINUES TO TRACK TO THE NORTHEAST.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
LOW PRESSURE WILL CONTINUE TO TRACK AWAY FROM THE REGION SUNDAY
NIGHT. ANY LINGERING SNOW SHOWERS OR MIXED PRECIPITATION WILL BE
DIMINISHING EARLY SUNDAY EVENING.
MUCH COLDER AIR WILL BEGIN TO POUR INTO THE REGION ON MONDAY WITH
HIGH TEMPERATURES OCCURRING EARLY IN THE DAY AND THEN FALLING IN
THE AFTERNOON. MONDAY NIGHT IS SHAPING UP AS A MAINLY CLEAR AND
BITTER COLD NIGHT WITH LOW FALLING TO 10 BELOW TO 15 BELOW ZERO
ACROSS THE NORTH AND ZERO TO 5 BELOW ZERO ACROSS CENTRAL AND DOWN
EAST. MAY NEED WIND CHILL ADVISORIES FOR NORTHERN AREAS AS WELL
AS WEST WINDS WILL MAKE IT FEEL EVEN COLDER.
TUESDAY WILL START OFF MAINLY CLEAR BEFORE CLOUDS BEGIN TO INCREASE
IN ADVANCE OF A CLIPPER TYPE SYSTEM APPROACHING FROM THE WEST.
EXPECT THE CHANCE FOR SNOW ESPECIALLY ACROSS DOWN EAST AREAS AS
THE SYSTEM MOVES EAST. THE SNOW MAY CONTINUE INTO THE FIRST PART
OF WEDNESDAY BEFORE DIMINISHING WEDNESDAY AFTERNOON.
EXPECT MAINLY DRY WEATHER WEDNESDAY NIGHT AND THURSDAY BUT
CONTINUED BELOW NORMAL TEMPERATURES.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
NEAR TERM: VFR CONDITIONS FOR THE MOST PART ACROSS THE REGION
W/TEMPO MVFR FOR THE NORTHERN TERMINALS TODAY W/SOME SNOW. WINDS
WILL PICK UP LATER THIS MORNING INTO THE AFTERNOON W/GUST
POTENTIAL ACROSS NORTHERN AREAS OF 25KTS.
SHORT TERM: VFR CONDITIONS EXPECTED ON SATURDAY. WIDESPREAD FLIGHT
RESTRICTIONS ARE EXPECTED TO DEVELOP SATURDAY NIGHT AND CONTINUE
ON SUNDAY WITH SNOW/SLEET/FREEZING RAIN EXPECTED TO AFFECT ALL
TERMINALS. R/WY SNOW ACCUMULATIONS FROM LATE SATURDAY NIGHT
THROUGH SUNDAY MAY RANGE FROM 3 TO 6 INCHES AT ALL THE TERMINALS
ALONG WITH THE POSSIBILITY OF SOME ICE ACCUMULATION ESPECIALLY
KBGR/KHUL TERMINALS. PRECIPITATION WILL BEGIN TO DIMINISH SUNDAY
EVENING WITH CONDITIONS IMPROVING TO VFR BY LATER SUNDAY NIGHT.
VFR CONDITIONS EXPECTED MONDAY. VFR MOST OF TUESDAY BUT POTENTIAL
FOR SNOW DEVELOPING LATE IN THE DAY ESPECIALLY KBGR/KBHB WITH
POSSIBLE IFR CONDITIONS BY TUE EVE.
&&
.MARINE...
NEAR TERM: A SMALL CRAFT ADVISORY REMAINS IN EFFECT THROUGH
TONIGHT W/GUSTS HITTING CLOSE TO 30 KTS. SEAS ARE RUNNING 7-10 FT
OVER THE OUTER ZONES AND THEY COULD BUILD A FEW MORE FT BEFORE
LEVELING OFF. SW WINDS WILL VEER TO THE WNW THIS AFTERNOON INTO
TONIGHT. ADJUSTMENTS WERE MADE TO THE SEAS TO ACCOUNT FOR THE
CURRENT CONDITIONS.
SHORT TERM: SMALL CRAFT ADVISORY CONDITIONS ARE POSSIBLE
SATURDAY. WINDS/SEAS WILL BRIEFLY DIMINISH EARLY SATURDAY EVENING
BEFORE INCREASING LATE SATURDAY NIGHT AND SUNDAY. A GALE WATCH
MAY BE REQUIRED FOR LATER SATURDAY NIGHT AND SUNDAY WITH CONTINUED
POTENTIAL FOR GALE FORCE WIND EARLY NEXT WEEK IN THE COLD
ADVECTION. VISIBILITY WILL BE UNRESRICTED SATURDAY AND THEN A
MILE OR LESS IN PRECIPITATION LATER SATURDAY NIGHT AND SUNDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST SATURDAY FOR ANZ050>052.
&&
$$
NEAR TERM...HASTINGS/HEWITT
SHORT TERM...DUDA
LONG TERM...DUDA
AVIATION...HASTINGS/HEWITT/DUDA
MARINE...HASTINGS/HEWITT/DUDA
AREA FORECAST DISCUSSION
NWS CARIBOU ME
634 AM EST FRI JAN 2 2015
.SYNOPSIS...
AN ARCTIC FRONT WILL SWEEP ACROSS THE REGION THIS AFTERNOON. HIGH
PRESSURE WILL BUILD INTO THE AREA TONIGHT THROUGH SATURDAY. LOW
PRESSURE TRACKING NORTHWEST OF MAINE WILL ALLOW A WARM FRONT TO
APPROACH THE REGION SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
630 AM UPDATE...ADJUSTED THE HRLY TEMPERATURES TO BRING THEM UP
FROM THE PREVIOUS THINKING COLDER IS JUST BEGINNING TO APCH
WESTERN MAINE ATTM W/THE ARCTIC FRONT. ANOTHER ADJUSTMENT WAS FOR
SNOW SHOWERS & SQUALLS A BIT FURTHER SOUTH THAN PREVIOUSLY
THOUGHT. MADE MANUAL ADJUSTMENTS TO THE POPS AND AREAL COVERAGE TO
ACCOUNT FOR ACTIVITY MAKING ITS WAY ACROSS CENTRAL AREAS. AN INCH
OF SNOW AT BEST IN THE HEAVIEST ACTIVITY THIS MORNING.
THE NAM AND LATEST HRRR 3KM WERE DOING QUITE WELL W/THE CURRENT
SETUP. THINKING HERE IS THAT THE FIRST BATCH OF SNOW SHOWERS
OCCURRING ATTM WILL MOVE ACROSS THE REGION W/THE BEST ENHANCEMENT
FROM MT. KATAHDIN TO THE SHERMAN-PATTEN REGION AS UP TO AN INCH OR
SNOW COULD ACCUMULATE. ANOTHER BATCH OF SNOW SHOWERS AND A FEW
SQUALLS LOOK LIKE THEY WILL SET UP BETWEEN 7 AM AND 10 AM THIS
MORNING W/THE ARCTIC FRONT APPROACHING. THE NAM SOUNDING SUPPORTS
850-700MBS LAPSE RATES AROUND 7.0 C/KM W/A FCST CAPE IN THE RANGE
OF 75-100 JOULES. THIS IS WHERE IS SOME AREAS COULD PICK UP
ANOTHER INCH OF SNOW W/SOME GUSTY WINDS. FURTHER SOUTH FROM THE
CENTRAL HIGHLANDS DOWN TO INTO TEH DOWNEAST REGION, MAINLY MOSTLY
CLOUDY W/A FEW FLURRIES. THINGS WIND DOWN NEAR OR AFTER 18Z.
TEMPERATURES LOOK LIKE THEY COULD ACTUALLY CLIMB SOME THIS MORNING
AHEAD OF THE FRONT AND THEN FALL BACK SHARPLY THIS AFTERNOON INTO
THE EVENING. ADJUSTMENTS WERE NEEDED TO THE MAXES TODAY TO BRING
THEM UP AND SHOW AN EARLY DAYTIME HIGH TEMP. CLOUDS SHOULD BREAK
UP THIS AFTERNOON AS THE LATEST IR SATELLITE IMAGERY SHOWS THAT
CLEARING BACK ACROSS QUEBEC AND THIS IS SUPPORTED BY THE NAM
GUIDANCE. WINDS WILL ALSO PICK UP FOR A TIME AS THE FRONT MOVES
IN.
THE CHALLENGE TONIGHT WILL BE HOW SOON THE REGION CLEARS OUT AND
HOW QUICKLY THE WINDS DROP OFF W/HIGH PRES MOVING RAPIDLY INTO
THE REGION OVERNIGHT. ANOTHER FACTOR WILL BE THE WNW FLOW COMING
OFF THE OPEN ST. LAWRENCE AS THIS AIRMASS IS QUITE COLD. SOUNDINGS
SHOW THE COLUMN TO DRY OUT THROUGH 500MBS W/THE EXCEPTION OF THE
CROWN OF MAINE AS SOME MOISTURE STAYS TRAPPED BETWEEN 925-850MBS.
DECIDED TO HANG ON TO SOME CLOUDS ACROSS THE CROWN AND WENT
W/CLEARING FOR THE REST OF THE CWA. SOMETIMES W/A SCENARIO LIKE
THIS ONE, LIGHT SNOW COULD SET UP, BUT SINCE THE AIRMASS LOOKS BE
DRY ABOVE 850MBS OVER THE CROWN, DECIDED TO STAY AWAY FROM ANY
MENTION OF LIGHT SNOW ATTM. STAYED CLOSE TO THE DAYCREW`S THINKING
OF OVERNIGHT LOWS DROPPING TO 10-15 BELOW ACROSS THE NORTH AND
CENTRAL AREAS W/SINGLE NUMBERS FOR THE DOWNEAST REGION INCLUDING
THE COAST. IF THE WINDS DROP OFF SOONER, THEN TEMPERATURES COULD
BE EVEN COLDER BY 7 AM SATURDAY. THIS CAN BE ASSESSED FURTHER BY
THE ONCOMING DAYCREW.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
SATURDAY IS SHAPING UP AS THE BETTER OF THE TWO WEEKEND DAYS AS
LONG AS YOU DONT MIND THE COLD. EXPECT PLENTY OF SUN TO START AS
HIGH PRESSURE MOVES ACROSS THE REGION. HIGH CLOUDS WILL BEGIN TO
INCREASE BY AFTERNOON. HIGH TEMPERATURES ON SATURDAY WILL ONLY
RANGE FROM THE SINGLE DIGITS TO AROUND 10 ABOVE NORTH AND CENTRAL
AREAS WITH MID TO UPPER TEENS DOWN EAST.
CLOUDS WILL CONTINUE TO INCREASE AND THICKEN SATURDAY EVENING IN
ADVANCE OF LOW PRESSURE APPROACHING FROM THE WEST. EXPECT
PRECIPITATION IN THE FORM OF SNOW TO DEVELOP FROM SOUTHWEST TO
NORTHEAST BY OR SHORTLY AFTER MIDNIGHT. WARMER AIR MOVING IN ALOFT
WILL RESULT IN THE PRECIPITATION MIXING WITH SLEET AND FREEZING
RAIN ACROSS DOWN EAST AREAS BY LATE SATURDAY NIGHT BUT THE
PRECIPITATION WILL REMAIN IN THE FORM OF ALL SNOW ACROSS NORTHERN
AND CENTRAL AREAS THROUGH THE NIGHT SATURDAY WITH SEVERAL INCHES
OF SNOW POSSIBLE BY DAYBREAK SUNDAY. LOW TEMPERATURES WILL OCCUR
EARLY IN THE EVENING SATURDAY BEFORE SLOWLY RISING OVERNIGHT.
PRECIPITATION WILL BE ONGOING FIRST THING SUNDAY AS LOW PRESSURE
CONTINUES TO TRACK TO OUR NORTHWEST. MODELS CONTINUE TO HINT AT A
WEAK TRIPLE POINT LOW FORMING ALONG THE MAINE COAST DURING SUNDAY.
AS THE PRIMARY LOW CONTINUES TO TRACK TO OUR NORTHWEST ON SUNDAY
WARMER AIR ALOFT WILL CONTINUE TO BRING MILDER AIR ALOFT WITH
PRECIPITATION CHANGE TO SLEET AND FREEZING RAIN ACROSS NORTHERN
AND CENTRAL AREAS AND EVEN ALL RAIN ACROSS DOWN EAST ESPECIALLY
THE COAST. RIGHT NOW IT APPEARS AS IF MOST AREAS WILL SEE SNOW
TOTAL RANGING FROM 3 TO 6 INCHES BEFORE THE CHANGEOVER OCCURS ON
SUNDAY. ICE ACCUMULATIONS ARE EXPECTED TO RANGE FROM ABOUT A
TENTH OF AN INCH CENTRAL AND DOWN EAST AND LESS THAN A TENTH OF AN
INCH ACROSS NORTHERN AREAS. SINCE THIS IS STILL A LATE FOURTH INTO
FIFTH PERIOD EVENT WONT BE ISSUING ANY HEADLINES YET BUT A THIS
TIME IT LOOKS LIKE WINTER WEATHER ADVISORIES WILL PROBABLY BE
NEEDED FOR JUST ABOUT ALL AREAS OF OUR CWA FOR SATURDAY NIGHT AND
SUNDAY FOR THE COMBINATION OF SNOW AND MIXED PRECIPITATION. THE
STEADY PRECIPITATION IS EXPECTED TO WIND DOWN ACROSS THE AREA AS
THE LOW CONTINUES TO TRACK TO THE NORTHEAST.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
LOW PRESSURE WILL CONTINUE TO TRACK AWAY FROM THE REGION SUNDAY
NIGHT. ANY LINGERING SNOW SHOWERS OR MIXED PRECIPITATION WILL BE
DIMINISHING EARLY SUNDAY EVENING.
MUCH COLDER AIR WILL BEGIN TO POUR INTO THE REGION ON MONDAY WITH
HIGH TEMPERATURES OCCURRING EARLY IN THE DAY AND THEN FALLING IN
THE AFTERNOON. MONDAY NIGHT IS SHAPING UP AS A MAINLY CLEAR AND
BITTER COLD NIGHT WITH LOW FALLING TO 10 BELOW TO 15 BELOW ZERO
ACROSS THE NORTH AND ZERO TO 5 BELOW ZERO ACROSS CENTRAL AND DOWN
EAST. MAY NEED WIND CHILL ADVISORIES FOR NORTHERN AREAS AS WELL
AS WEST WINDS WILL MAKE IT FEEL EVEN COLDER.
TUESDAY WILL START OFF MAINLY CLEAR BEFORE CLOUDS BEGIN TO INCREASE
IN ADVANCE OF A CLIPPER TYPE SYSTEM APPROACHING FROM THE WEST.
EXPECT THE CHANCE FOR SNOW ESPECIALLY ACROSS DOWN EAST AREAS AS
THE SYSTEM MOVES EAST. THE SNOW MAY CONTINUE INTO THE FIRST PART
OF WEDNESDAY BEFORE DIMINISHING WEDNESDAY AFTERNOON.
EXPECT MAINLY DRY WEATHER WEDNESDAY NIGHT AND THURSDAY BUT
CONTINUED BELOW NORMAL TEMPERATURES.
&&
.AVIATION /11Z FRIDAY THROUGH TUESDAY/...
NEAR TERM: VFR CONDITIONS FOR THE MOST PART ACROSS THE REGION
W/TEMPO MVFR FOR THE NORTHERN TERMINALS TODAY W/SOME SNOW. WINDS
WILL PICK UP LATER THIS MORNING INTO THE AFTERNOON W/GUST
POTENTIAL ACROSS NORTHERN AREAS OF 25KTS.
SHORT TERM: VFR CONDITIONS EXPECTED ON SATURDAY. WIDESPREAD FLIGHT
RESTRICTIONS ARE EXPECTED TO DEVELOP SATURDAY NIGHT AND CONTINUE
ON SUNDAY WITH SNOW/SLEET/FREEZING RAIN EXPECTED TO AFFECT ALL
TERMINALS. R/WY SNOW ACCUMULATIONS FROM LATE SATURDAY NIGHT
THROUGH SUNDAY MAY RANGE FROM 3 TO 6 INCHES AT ALL THE TERMINALS
ALONG WITH THE POSSIBILITY OF SOME ICE ACCUMULATION ESPECIALLY
KBGR/KHUL TERMINALS. PRECIPITATION WILL BEGIN TO DIMINISH SUNDAY
EVENING WITH CONDITIONS IMPROVING TO VFR BY LATER SUNDAY NIGHT.
VFR CONDITIONS EXPECTED MONDAY. VFR MOST OF TUESDAY BUT POTENTIAL
FOR SNOW DEVELOPING LATE IN THE DAY ESPECIALLY KBGR/KBHB WITH
POSSIBLE IFR CONDITIONS BY TUE EVE.
&&
.MARINE...
NEAR TERM: A SMALL CRAFT ADVISORY REMAINS IN EFFECT THROUGH
TONIGHT W/GUSTS HITTING CLOSE TO 30 KTS. SEAS ARE RUNNING 7-10 FT
OVER THE OUTER ZONES AND THEY COULD BUILD A FEW MORE FT BEFORE
LEVELING OFF. SW WINDS WILL VEER TO THE WNW THIS AFTERNOON INTO
TONIGHT. ADJUSTMENTS WERE MADE TO THE SEAS TO ACCOUNT FOR THE
CURRENT CONDITIONS.
SHORT TERM: SMALL CRAFT ADVISORY CONDITIONS ARE POSSIBLE
SATURDAY. WINDS/SEAS WILL BRIEFLY DIMINISH EARLY SATURDAY EVENING
BEFORE INCREASING LATE SATURDAY NIGHT AND SUNDAY. A GALE WATCH
MAY BE REQUIRED FOR LATER SATURDAY NIGHT AND SUNDAY WITH CONTINUED
POTENTIAL FOR GALE FORCE WIND EARLY NEXT WEEK IN THE COLD
ADVECTION. VISIBILITY WILL BE UNRESRICTED SATURDAY AND THEN A
MILE OR LESS IN PRECIPITATION LATER SATURDAY NIGHT AND SUNDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST SATURDAY FOR ANZ050>052.
&&
$$
NEAR TERM...HEWITT
SHORT TERM...DUDA
LONG TERM...DUDA
AVIATION...HEWITT/DUDA
MARINE...HEWITT/DUDA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
508 AM EST FRI JAN 2 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 351 PM EST THU JAN 1 2015
DEEP TROUGH ALOFT CENTERED OVER HUDSON BAY. MULTIPLE SHORTWAVES
MOVING THROUGH THE BASE OF THE TROUGH...BUT AFTER THE SHORTWAVE
MOVED THROUGH THIS MORNING...THERE IS NO LARGER SCALE SUPPORT OVER
THE AREA OR UPSTREAM. PRIMARY COLD FRONT TIED TO THE LAST SHORTWAVE
IS CURRENTLY SINKING SOUTHWARD OVER UPR MICHIGAN. BAND OF HEAVY SNOW
ALONG THE FRONT HAS WORKED THROUGH MARQUETTE AND MUNISING AND IS NOW
ALLIGNED FM SAWYER TO CHATHAM TO SHINGLETON AND TO NEWBERRY AS OF 20Z.
VSBY DOWN TO 1/4SM IN THIS SNOW BAND...BUT IT IS NOT LASTING TOO LONG.
LES OVER THE WESTERN CWA IS SCUFFLING ALONG. IN FACT AFTER THE FRONT
MOVED THROUGH THE KEWEENAW...SPOTS HAVE CLEARED OUT BRIEFLY. HINTS OF
WIND PARALLEL BANDS OVER WESTERN LK SUPERIOR...BUT DRY AIR AND
INVERSIONS BLO 5KFT IS LIMITING THIS DEVELOPMENT. BETTER LES
DEVELOPMENT OVER EASTERN LK SUPERIOR WITH CLOUD STREETS EXTENDING
BACK TO NCNTRL LK SUPERIOR. WILL TAKE A FEW HOURS...BUT DO EXPECT AT
LEAST MODERATE LES TO DEVELOP IN THE NW LOW-LEVEL WINDS INTO EASTERN
CWA. BLYR WINDS OVER 30 KTS INTO THE EVENING WILL RESULT IN BLSN/POOR
VSBY IN THE HEAVIER SNOW BANDS. INVERSIONS 5-8 KFT AND TEMPS AT
INVERSION TOP OF -20C SHOULD AT LEAST RESULT IN SCT HEAVIER SNOW
SHOWERS. 17Z HRRR DOING NICE JOB WITH EXPECTED EVOLUTION THROUGH THE
EVENING...THOUGH IT SEEMS A BIT SLOW WITH TIMING OF HEAVIER SNOW BAND
TIED TO THE FRONT.
ADDITIONAL SNOW AMOUNTS SHOULD STAY IN CHECK GIVEN LACK OF ENHANCED
MOISTURE AND LIFT SINCE WE ARE WITHIN A PURE LES REGIME. SUPPOSE IF
SNOW BANDS CAN STAY ANCHORED IN ONE PLACE THROUGH THE NIGHT...MAY SEE
SEVERAL INCHES OF FLUFFY ACCUMS AS ALL CONVECTIVE DEPTH IS WITHIN THE
DGZ. ALREADY ISSUED LES ADVISORY THROUGH MIDNIGHT FOR ALGER...NORTHERN
SCHOOLCRAFT...AND LUCE COUNTIES. AFTER MIDNIGHT SEEMS THAT DRY AIR
AND LOWER INVERSIONS THAT ARE AFFECTING WESTERN LK SUPERIOR AND CWA
WILL PUT CRIMP IN THE LES INTENSITY OVERNIGHT. WEAK LES WILL CONTINUE
INTO FRIDAY...MAINLY FOR AREAS FAVORED BY WNW-W WINDS...SO ESSENTIALLY
THE SNOW BELTS OF THE KEWEENAW AND ALSO TO THE EAST OF MUNISING.
CONDITIONS EVEN MORE UNFAVORABLE THAN LATER TONIGHT...BUT WITH DGZ
DOMINATING THE CONVECTIVE LAYER STILL COULD SQUEEZE OUT A COUPLE MORE
INCHES OF FLUFF IN PERSISTENT SNOW SHOWERS.
AWAY FM THE LES TONIGHT...LOWERED SKY COVER AND TEMPERATURES AS THE
DRIER AIR SHOULD WIN OUT AS IS OCCURRING UPSTREAM IN MINNESOTA AND
NORTHWEST ONTARIO THIS AFTN. INTERIOR TEMPS SHOULD DIP WELL BLO ZERO
ONCE THE NW WINDS BEHIND THE COLD FRONT BEGIN TO BACK OFF. SHOULD BE
SHARP GRADIENT TO MIN TEMPS AS YOU GET CLOSER TO LK SUPERIOR DUE TO
LINGERING LAKE EFFECT CLOUDS AS 925MB WINDS STAY WNW-NW THROUGH THE
NIGHT. ALSO MAY SEE TEMPS STEADY OR RISE LATE IN THE WEST WITH
ADVANCING DECK OF 6-9KFT ALTOSTRATUS CLOUDS. ANOTHER COOL DAY WITH
AFTN READINGS IN THE TEENS OVER THE CWA.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 333 AM EST FRI JAN 2 2015
NAM SHOWS A 500 MB TROUGH OVER THE SOUTHERN PLAINS 12Z SAT WITH A
TROUGH ALSO IN THE NORTHERN ROCKIES. THE TROUGH IN THE SOUTHERN
PLAINS HEADS NORTHEAST WHILE THE NORTHERN ROCKIES TROUGH HEADS EAST
ON SAT AND THEY COMBINE SAT NIGHT TO CARVE OUT A DEEP TROUGH OVER
THE UPPER GREAT LAKES WHICH REMAINS THROUGH SUN NIGHT. NAM AND GFS
SHOW 850-500 MB Q-VECTOR CONVERGENCE MOVING THROUGH ON SAT AND SAT
NIGHT WITH MORE CONVERGENCE RETURNING FOR SUN NIGHT.
DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST. DID INTRODUCE
SOME POPS IN FOR SATURDAY DUE TO LAKE ENHANCEMENT FROM LAKE MICHIGAN
COMING IN AS LAKE SURFACE TEMPERATURES ARE AROUND 2C TO 4C AND 850
MB TEMPERATURES ON SOUTH WINDS ARE AROUND -6C TO -4C AND THAT IS
ENOUGH FOR SOME LIGHT LAKE ENHANCEMENT POSSIBILITIES ANYWAY AS THE
SOUTHERN SHORTWAVE HEADS NORTHEAST AND CLIPS THE SOUTHERN CWA SAT
AFTERNOON. HAVE HIGH POPS IN FOR SAT NIGHT WITH CATEGORICAL POPS AS
THE TWO SYSTEMS COMBINE OVER THE AREA WITH THE HIGHER QPF AMOUNTS
REMAINING TO THE SOUTHEAST OF THE CWA WITH THE CWA FEELING THE
EFFECTS MOST FROM THE NORTHERN SYSTEM. COL AIR WILL MOVE IN FOR SAT
NIGHT INTO SUNDAY. LAKE EFFECT THEN GETS GOING FOR SUNDAY AND WENT
HIGHEST POPS IN NORTH TO NORTHWEST LAKE EFFECT SNOW BELTS.
IN THE EXTENDED...GFS AND ECMWF SHOW A DEEP 500 MB TROUGH OVER MOST
OF THE U.S. 12Z MON WITH VERY COLD AIR ENTRENCHED OVER THE AREA.
THIS UPPER TROUGH REMAINS OVER THE AREA INTO WED BEFORE THE TROUGH
AXIS AND THE COLDEST AIR MOVE OFF TO THE EAST AND SOME MODIFICATION
IN THE AIRMASS BEGINS FOR THU. TEMPERATURES WILL CONTINUE TO BE WELL
BELOW NORMAL AND LAKE EFFECT SNOW WILL CONTINUE FOR THIS FORECAST
PERIOD AS SFC HIGH PRESSURE REMAINS OVER THE CENTRAL PLAINS FOR THIS
PERIOD. LOOKS LIKE THERE COULD BE AN ALBERTA CLIPPER TYPE SYSTEM
PASSING BY FOR THU.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1153 PM EST THU JAN 1 2015
UNDER A COLD AIR MASS AND WNW FLOW...LAKE EFFECT SNOW SHOWERS WILL
AFFECT KCMX THRU THE FIRST HALF OF THIS FCST PERIOD WITH MVFR
CONDITIONS LIKELY PREVAILING. EXPECT SOME PERIODS OF VFR INITIALLY
AS DRIER AIR HAS CAUSED -SHSN TO DIMINISH. TODAY...BACKING WINDS
SHOULD RESULT IN A ZONE OF ENHANCED CONVERGENCE AND A BAND OF
HEAVIER -SHSN LIFTING N AND IMPACTING KCMX LATE MORNING/EARLY AFTN
WITH IFR CONDITIONS POSSIBLE. THEREAFTER...CONDITIONS SHOULD BECOME
VFR AS SW WINDS PUSH LAKE EFFECT N OF THE TERMINAL. AT KIWD...VFR
CONDITIONS WILL PREVAIL OVERNIGHT AS DRY AIR AND WINDS HAVING JUST
ENOUGH OF A WESTERLY COMPONENT WILL KEEP LAKE EFFECT SNOW
SHOWERS/MVFR CONDITIONS N OF THE TERMINAL. WITH WINDS BACKING
FURTHER TODAY...VFR CONDITIONS WILL CONTINUE AT KIWD. AT KSAW...
DOWNSLOPE COMPONENT TO THE WIND OVERNIGHT SHOULD KEEP CONDITIONS
VFR. VFR CONDITIONS WILL THEN CONTINUE THRU TODAY.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 508 AM EST FRI JAN 2 2015
THE BUSY MARINE WEATHER WILL PICK UP AGAIN AS WE HEAD INTO THE
WEEKEND...WITH GALES AND HEAVY FREEZING SPRAY RETURNING.
HEAVY FREEZING SPRAY WILL SLOWLY DIMINISH THIS MORNING AS WINDS
DECREASE TO AROUND 20KTS OR LESS. A WEAK TROUGH ACROSS THE E HALF OF
LAKE SUPERIOR WILL BE REPLACED BY A RIDGE TODAY AS THE MAIN HIGH
ACROSS WISCONSIN BUILDS ACROSS MICHIGAN AND EXITS ACROSS LOWER GREAT
LAKES LATE THIS AFTERNOON. A LOW PRESSURE ACROSS THE N PLAINS THIS
EVENING WILL SLIDE SE AND CONSOLIDATE WITH A MID MISSISSIPPI VALLEY
LOW. THE LOW WILL THEN DEEPEN ACROSS S LOWER MICHIGAN SUNDAY
EVENING...AND LAKE HURON EARLY SUNDAY MORNING. THE LOW WILL CONTINUE
INTO S QUEBEC SUNDAY...KEEPING A TROUGH OVER LAKE SUPERIOR SUNDAY
INTO MONDAY. FOR MONDAY AND TUESDAY A RIDGE WILL SETTLE ACROSS THE
PLAINS STATES AS A WEAK LOW DRIFTS OVER THE GREAT LAKES REGION
TUESDAY.
HEAVY FREEZING SPRAY AND GALE WATCHES HAVE BEEN POSTED FOR MUCH OF
LAKE SUPERIOR FROM LATE SATURDAY NIGHT THROUGH SUNDAY...WITH HEAVY
FREEZING SPRAY WARNINGS CONTINUING INTO AT LEAST TUESDAY. WILL NOT
BE SURPRISED IF HEAVY FREEZING SPRAY HEADLINES NEEDED TO BE EXTENDED
BEYOND WEDNESDAY AS THE COLDEST AIR OF THE SEASON SETTLES INTO THE
REGION.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM LATE SATURDAY NIGHT THROUGH MONDAY MORNING FOR
LSZ266-267.
HEAVY FREEZING SPRAY WATCH FROM SUNDAY EVENING THROUGH TUESDAY
EVENING FOR LSZ267.
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST /6 AM CST/ THIS
MORNING FOR LSZ241>245-263>266.
HEAVY FREEZING SPRAY WATCH FROM LATE SATURDAY NIGHT THROUGH
TUESDAY EVENING FOR LSZ266.
HEAVY FREEZING SPRAY WATCH FROM LATE SATURDAY NIGHT THROUGH
MONDAY AFTERNOON FOR LSZ162.
GALE WATCH FROM LATE SATURDAY NIGHT THROUGH SUNDAY AFTERNOON FOR
LSZ263>265.
HEAVY FREEZING SPRAY WATCH FROM LATE SATURDAY NIGHT THROUGH LATE
MONDAY NIGHT FOR LSZ263>265.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...07
AVIATION...ROLFSON
MARINE...KF
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
554 AM CST FRI JAN 2 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 255 AM CST FRI JAN 2 2015
A QUIET SHORT TERM PERIOD FOR TODAY AND TONIGHT. MAIN CHANGE TO
THE FORECAST WAS TO INCREASE SKY COVER AS A SOLID DECK OF
STRATUS CONTINUES BUILDING IN FROM THE WEST. THIS TREND IS
EXPECTED TO CONTINUE...WITH THE SKY BECOMING INCREASINGLY CLOUDY
FROM WEST TO EAST TODAY. SURFACE HIGH PRESSURE SLIDING EAST ACROSS
THE FA EARLY THIS MORNING HAS ALLOWED SOUTHERLY FLOW WITH WAA TO
ENTER WESTERN MN...WHICH IS CO-LOCATED WITH THE STRATUS DECK.
TEMPERATURES ARE BEING HELD IN THE UPPER TEENS FOR MUCH OF THAT
AREA...WHERE SINGLE DIGITS ON EITHER SIDE OF ZERO WHERE PREVALENT
FURTHER EAST UNDER CLEAR SKIES EARLY THIS MORNING.
FOR TODAY...AS THE HIGH CONTINUES EAST...A WEAK WARM FRONT WILL
LIFT THROUGH THE STATE AHEAD OF A LOW PRESSURE AREA THAT WILL BE
DROPPING SOUTHEAST OUT OF SOUTHWESTERN CANADA. WHILE SLIGHTLY
COOLER TEMPERATURES THAN YESTERDAY ARE EXPECTED...TODAY`S HIGHS
WILL BE NEAR NORMAL FOR THIS TIME OF YEAR. THE LOW WILL ADVANCES
SOUTHEAST TO NEAR FARGO BY TOMORROW MORNING...WITH ACCUMULATING
SNOW ONGOING TO THE NORTH OF THE LOW AT THAT TIME. BEST FORCING
STILL REMAINS NORTH OF THE FA...SO KEPT POPS OUT FOR THE SHORT
TERM FORECAST.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 255 AM CST FRI JAN 2 2015
MAIN CONCERNS FOR THE LONG TERM ARE...A CLIPPER-TYPE SYSTEM FOR
SAT AFTN-EVE...VERY COLD AIR FOR THE FIRST HALF OF NEXT WEEK...
AND ANOTHER CLIPPER-TYPE SYSTEM MON NIGHT INTO EARLY TUE.
SPLIT UPPER LEVEL FLOW WILL PRESENT TWO DISTINCT AREAS OF LOW
PRESSURE FOR THE CENTRAL CONUS...ONE A CLIPPER-TYPE SYSTEM OVER
THE NRN TIER STATES AND ANOTHER DEVELOPING OVER THE TX/OK
PANHANDLES. THE FOCUS WILL BE ON THE NRN STREAM SYSTEM AS GOOD
MODEL AGREEMENT PUTS THE SRN STREAM SYSTEM TOO FAR DISPLACED TO
THE S...EVEN WHILE IT IS MOVING NE...TO BE A FACTOR FOR SENSIBLE
WX IN MN AND WRN WI. THE PHASING OF THESE TWO STREAMS WILL TAKE
PLACE OVER THE CENTRAL-ERN GREAT LAKES...THUS NOT FACTORING INTO
THE WX IN THIS AREA. THEREFORE...FOCUSING ON THE NRN STREAM
SYSTEM...THIS SYSTEM WILL DROP ACRS THE REGION SAT AFTN THRU SAT
EVE. THOUGH THE BEST FORCING WILL BE N OF THE AREA...PRODUCING
MORE SNOWFALL OVER NRN MN THAN CENTRAL-SRN MN...A VERY TIGHT PRES
GRADIENT ON THE BACKSIDE OF THIS SYSTEM WILL LIKELY PRODUCE
BLOWING/DRIFTING SNOW WITH EVEN MINOR SNOWFALL ACCUMULATIONS ACRS
MUCH OF THE WFO MPX CWFA. SUSTAINED SPEEDS WILL LIKELY INCRS TO
THE 25-35 MPH RANGE WITH GUSTS UPWARDS OF 45 MPH.
ONCE THIS SYSTEM PASSES ACRS...VERY STRONG CAA WILL COMMENCE AS
BOTH SFC AND UPR LVL FLOW BECOMES PREDOMINANTLY NW IN ADVANCE OF A
1046MB HIGH DROPPING IN FROM WRN CANADA. HIGHS WILL DROP TO THE
SINGLE DIGITS...IF NOT JUST BELOW ZERO...WHILE LOW TEMPERATURES
DROP TO NEARLY -20 SAT NIGHT THRU TUE NIGHT. THE STRONG WINDS ON
THE BACKSIDE OF THE SYSTEM WILL LIKELY PRODUCE WIND CHILL VALUES
IN THE -30 TO -40 DEGREE RANGE FOR SAT NIGHT THRU SUN NIGHT...AND
AS LOW AS -25 GOING INTO MON NIGHT AS WINDS DROP OFF.
THE NEXT SYSTEM OF CONSEQUENCE COMES LATE DAY MON INTO MON NIGHT.
NOTICEABLE TIMING DIFFERENCES HAVE THE GFS MUCH FASTER THAN A
COMPOSITE OF THE ECMWF/GEM/DGEX FOR A CLIPPER-TYPE SYSTEM SWINGING
EWD THRU THE DAKOTAS INTO THE UPR MISS RIVER VALLEY. MAIN CHC FOR
PRECIP COMES MON NIGHT...BUT SOME -SN MAY DEVELOP PRIOR TO 00Z IN
WRN MN SO HAVE KEPT CHC POPS OUT THAT WAY FOR MON AFTN. MINOR SNOW
ACCUMULATIONS LOOK TO OCCUR FROM THIS SYSTEM...BUT THE MAIN ISSUE
WILL CONTINUE TO BE THE VERY COLD AIR IN PLACE...REINFORCED BY
ANOTHER BOUT OF CAA BEHIND THIS SYSTEM WHICH WILL AGAIN FORCE
SINGLE DIGIT HIGHS AND SUB-ZERO LOWS MIDWEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 541 AM CST FRI JAN 2 2015
AS ALLUDED TO LAST ISSUANCE...WIDESPREAD STRATUS DECK CONTINUES TO
ADVANCE EASTWARD FASTER THAN ANY GUIDANCE WOULD LIKE TO INDICATE.
KEPT A GENERALLY PESSIMISTIC FORECAST GOING FOR TODAY AND
TONIGHT. THE STRATUS WILL OVERTAKE MSP VERY SOON THIS MORNING AND
CONTINUE EASTWARD THROUGH WESTERN WISCONSIN THROUGH THE DAY AS
THE SURFACE HIGH CONTINUES EASTWARD. THE PROBLEM IS THE CEILING
HEIGHT WITH THIS STRATUS...IT CONTINUES TO TEETER ON THE EDGE OF
MVFR/VFR WITH THE NORTHERN HALF OF THE CWA SEEING CIGS JUST ABOVE
3K FT...BUT SOUTHERN MN BETWEEN 025-030. FURTHER NORTHWEST
HOWEVER...CIGS ARE MVFR TOO SO EXPECTING THAT TO EVENTUALLY REACH
AXN AND STC. THE RAP SEEMS TO HAVE THE BEST HANDLE ON THE CLOUDS
EARLY THIS MORNING...SO THE FORECAST WAS LARGELY BASED ON A
COMBINATION OF RAP FORECAST SOUNDINGS AND CURRENT SATELLITE
TRENDS. CEILINGS MAY LOWER TO AROUND 1K FT TONIGHT THROUGH
SATURDAY MORNING...BUT A DRY TONGUE TO THE SOUTH A CLIPPER SYSTEM
MAY SCOUR CLOUDS OUT FOR A TIME SATURDAY MORNING. SO...A LOW
CONFIDENCE FORECAST FOR TONIGHT AND TOMORROW.
KMSP...STRATUS JUST TO THE WEST AT THIS TIME...AND IT LOOKS LIKE
MSP WILL BE RIGHT ON THE EDGE OF MVFR/VFR CIGS THIS MORNING...SO
EXPECT THE CEILING TO BOUNCE AROUND 3K FEET BEFORE LOWERING THIS
AFTERNOON AND EVENING.
/OUTLOOK FOR KMSP/
SAT NGT...MVFR WITH -SN/BLSN. WINDS NW AT 20G35KTS.
SUN...MVFR LIKELY. WINDS NW AT 15G25KTS.
MON...VFR. WINDS W AT 10G15KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...SPD
LONG TERM...JPC
AVIATION...SPD
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
832 AM EST FRI JAN 2 2015
.SYNOPSIS...
SURFACE HIGH PRESSURE WILL MOVE ACROSS THE REGION TODAY. A WARM
FRONT WILL APPROACH FROM THE SOUTH TONIGHT AND PASS THROUGH THE
AREA ON SATURDAY. THIS WILL BE FOLLOWED BY A COLD FRONT SATURDAY
NIGHT WHICH WILL USHER IN MUCH COLDER AIR FOR NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SHOWERS ASSOCIATED WITH A WEAK UPPER LEVEL DISTURBANCE ARE
PUSHING EAST ACROSS FAR SOUTHERN PORTIONS OF OUR FA THIS MORNING.
WE HAVE HAD SOME REPORTS OF SLEET WITH THIS AND WILL CONTINUE
WITH A MENTION OF A MIXED BAG OF PCPN THROUGH THE REST OF THIS
MORNING WITH A GRADUAL TRANSITION TO MORE RAIN AS WE SLOWLY WARM.
LATEST RAP AND HRRR SUGGEST THAT THIS PCPN SHOULD SLIDE OFF TO OUR
EAST/SOUTHEAST BY EARLY AFTERNOON. EXPECT HIGHS TODAY RANGING FROM
THE MID 30S NORTHWEST TO UPPER 30S/NEAR 40 ACROSS THE FAR SOUTH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
MODELS ARE IN FAIRLY DECENT AGREEMENT IN TERMS OF SYNOPTIC SCALE
SYSTEMS. HAVE USED A BLEND OF THE NAM/GFS/ECMWF FOR THE SHORT TERM
FORECAST.
UPR LVL LOW OVER THE DESERT SW WILL BEGIN TO EJECT NE TO THE SRN
PLAINS BY SATURDAY MORNING. AS THE HIGH MOVES OFF TO THE EAST
TONIGHT...WARM...MOIST RETURN IN THE FORM A LOW LEVEL JET WILL
BRING AN INCREASING THREAT FOR PCPN FROM SOUTH TO NORTH THROUGH
THE OVERNIGHT HOURS. WE SHOULD SEE A LITTLE DROP OFF TO
TEMPERATURES EARLY THIS EVENING...THEN AS CLOUDS THICKEN AND WINDS
INCREASE...THEY SHOULD STEADY OUT AND SLIGHTLY RISE THROUGH THE
OVERNIGHT HOURS. THE ONSET OF PCPN AND SURFACE TEMPERATURES WILL
BE CRITICAL IN FORECASTING PCPN TYPE. IT LOOKS LIKE LOCATIONS
GENERALLY ALONG AND SOUTH OF THE OHIO RIVER WILL REMAIN IN LIQUID
FORM AS TEMPERATURES REMAIN SLIGHTLY ABOVE FREEZING. POINTS TO THE
NORTH...PCPN MAY START OUT BRIEFLY AS A LITTLE SLEET...BUT WITH
TEMPERATURES AT OR SLIGHTLY BELOW FREEZING...THE THREAT FOR A
PERIOD OF FREEZING RAIN WILL EXIST AS MUCH WARMER AIR ALOFT IS
ADVECTED NORTHWARD. WITH TEMPERATURES NEAR FREEZING...ICING
ACCRETION SHOULD BE LIMITED...BUT SOME LIGHT ICING WILL LIKELY
OCCUR ON EXPOSED OBJECTS AND ELEVATED SURFACES LIKE UNTREATED
BRIDGES AND OVERPASSES. A FREEZING RAIN ADVISORY MAY BE NEEDED FOR
NORTH OF THE OHIO RIVER LATE TONIGHT INTO EARLY SATURDAY MORNING
FOR AMOUNTS GENERALLY LESS THAN A 0.10 OF AN INCH. WILL CONTINUE
TO HIGHLIGHT THE THREAT IN THE HWO PRODUCT.
ON SATURDAY...UPR LVL LOW WILL MOVE NORTHEAST TO THE CENTRAL
PLAINS BY SATURDAY EVENING. AS IT DOES...A WARM FRONT WILL LIFT
NORTH ACRS THE REGION AS SURFACE LOW PRESSURE DEEPENS TO OUR SOUTHWEST.
ANY FREEZING RAIN ACRS THE FAR NORTH SHOULD CHANGE TO ALL RAIN BY
MID MORNING AS TEMPERATURES CONTINUE TO SLOWLY WARM. FOR THE
REMAINDER OF SATURDAY...MOISTURE CONVERGENCE AND LIMITED INSTABILITY
WILL BRING SHOWERS AND PERHAPS AN ELEVATED THUNDERSTORM TO THE
REGION FOR THE REMAINDER OF THE DAY. HIGHS WILL OCCUR BY EVENING
AS LOW LEVEL FLOW TURNS SOUTHERLY. THEY SHOULD RANGE FROM NEAR 50
NORTH TO THE UPPER 50S SOUTH OF THE OHIO RIVER.
FOR SATURDAY NIGHT...UPR LVL LOW WILL PHASE WITH ENERGY FROM THE
NORTHWEST. THIS WILL CONTINUE TO DEEPEN THE SURFACE LOW AS IT MOVE
NORTHEAST THROUGH THE GREAT LAKES. A COLD FRONT WILL THEN SWING
EASTWARD THROUGH THE AREA. WIDESPREAD SHOWERS AND PERHAPS EMBEDDED
THUNDER ARE EXPECTED ALONG AND AHEAD OF THE FRONT. MODELS CONTINUE
TO ADVERTISE STRONG LOW LEVEL WINDS ALONG AND AHEAD OF THE FRONT.
THERE IS SOME CONCERN THAT THERE COULD BE SOME ENHANCED WIND GUSTS
WITH CONVECTIVE PCPN SHOULD IT TRY TO ORGANIZE INTO A LINEAR
STRUCTURE. SHERB PARAMETERS SUPPORT THIS. AM NOT READY YET TO
PLACE THE CONCERN IN THE HWO...BUT WILL CERTAINLY ANALYZE
CONVECTION ALLOWING MODELS AS WE GET CLOSER TO SATURDAY NIGHT. WE
SHOULD AT LEAST SEE SOME SYNOPTIC WIND GUSTS AROUND 30 KNOTS WITH
FRONTAL PASSAGE SATURDAY NIGHT. OVERNIGHT LOWS WILL OCCUR BY
SUNDAY MORNING AS TEMPERATURES FALL BEHIND THE FRONT. OVERALL WE
SHOULD SEE 1 TO 1.50 INCHES OF RAIN WITH THIS SYSTEM. STREAM FLOW
ACRS OUR REGION IS LOW AS IS OUR FLASH FLOOD GUIDANCE...SO THE
FLOOD THREAT OTHER THAN SOME MINOR SHORT TERM FLOODING SHOULD
REMAIN LOW AS WELL.
FOR SUNDAY...ADDITIONAL UPR LVL ENERGY ALONG WITH STRONG CAA WILL
KEEP SKIES CLOUDY ALONG WITH A THREAT OF SCATTERED RAIN AND/OR
SNOW SHOWERS. LITTLE SNOW ACCUMULATION IS EXPECTED. HIGH TEMPERATURES
WILL OCCUR EARLY WITH TEMPERATURES DROPPING THROUGH THE DAY.
BY SUNDAY NIGHT...ARCTIC HIGH PRESSURE WILL BUILD SOUTHEAST INTO
THE THE AREA. CLOUDS SHOULD DECREASE SOME ALONG WITH A TAPERING
OFF OF SCATTERED SNOW SHOWERS.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
ARCTIC HIGH PRESSURE WILL WORK INTO THE AREA FOR MONDAY ALLOWING
FOR DRY CONDITIONS. TEMPERATURES WILL STRUGGLE TO RISE WITH THE
COLD AIRMASS IN PLACE. A CLIPPER WILL MOVE THROUGH THE AREA LATE
MONDAY NIGHT INTO THE DAY ON TUESDAY. TEMPERATURES WILL BE COLD
ENOUGH THAT PRECIPITATION WILL ALL BE IN THE FORM OF SNOW. THESE
TYPE OF SYSTEMS ARE TYPICALLY PRETTY EFFICIENT WITH HIGH SNOW TO
LIQUID RATIOS. MODELS HAVE COME INTO DECENT AGREEMENT ON THE
TIMING AND STRENGTH OF THIS FEATURE. THE BEST CHANCE FOR
ACCUMULATING SNOW WILL BE ACROSS NORTHERN PORTIONS OF THE FA. WITH
DECENT MODEL AGREEMENT AND THIS FEATURE SHOWING UP FOR MULTIPLE
RUNS HAVE DECIDED TO CONTINUE TO INCREASE PRECIPITATION CHANCES ON
TUESDAY.
MOST OF THE PRECIPITATION WILL TAPER OFF TUESDAY EVENING HOWEVER
SOME RESIDUAL SNOW SHOWERS WILL STICK AROUND TUESDAY NIGHT INTO
WEDNESDAY ACROSS NORTHERN PORTIONS OF THE FA WITH WINDS OFF OF THE
LAKE.
THE COLDEST TEMPERATURES OF THE LONG TERM PERIOD LOOK TO BE
WEDNESDAY NIGHT ACROSS THE AREA. HIGH PRESSURE WILL BE IN PLACE AND
THERE WILL BE SOME BREAKS IN THE CLOUDS. WITH SOME SNOW ON THE
GROUND STILL FROM THE TUESDAY SYSTEM ALSO POSSIBLE AND THE COLD
AIRMASS IN PLACE EXPECT TEMPERATURES TO DROP DOWN INTO THE SINGLE
DIGITS ACROSS MOST LOCATIONS. TEMPERATURES WILL START TO RISE
SLIGHTLY ON THURSDAY AS SOUTHERLY FLOW DEVELOPS.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS ARE EXPECTED THROUGH THE MAJORITY OF THE TAF
PERIOD...WITH SOME DETERIORATING CONDITIONS ON SATURDAY MORNING.
MID-LEVEL CLOUDS HAVE OVERSPREAD THE REGION...AND A GRADUAL
THICKENING AND LOWERING WILL CONTINUE THROUGH TODAY AND INTO
TONIGHT. HOWEVER...CEILINGS SHOULD REMAIN VFR UNTIL AFTER
MIDNIGHT. SOME LIGHT PRECIPITATION (WHICH COULD BE A MIX OF
SNOW/SLEET/RAIN) IS MAINLY EXPECTED TO REMAIN JUST SOUTH OF THE
CINCINNATI AREA THIS MORNING...BUT SOME BRIEF PERIODS OF LIGHT
PRECIPITATION WILL BE POSSIBLE THROUGH MID-AFTERNOON. WINDS WILL
REMAIN VERY LIGHT THROUGH THE NEXT 12-18 HOURS...GRADUALLY TURNING
FROM SW TO SE.
ON SATURDAY MORNING...PRECIPITATION WILL MOVE INTO THE AREA FROM
THE SOUTH. AT THE TIME OF ONSET...A PERIOD OF FREEZING RAIN WILL
BE POSSIBLE. THIS MAY BE VERY BRIEF AT THE CINCINNATI TAF
SITES...BUT COULD LAST A COUPLE HOURS FURTHER TO THE NORTH. AS
THIS OCCURS...CEILINGS WILL GRADUALLY LOWER TO MVFR CATEGORIES.
THERE IS SOME POTENTIAL FOR CONDITIONS TO DETERIORATE FURTHER THAN
THIS...WITH IFR CEILINGS/VISIBILITIES BEING POSSIBLE...BUT THIS
WILL DEPEND ON THE INTENSITY OF THE PRECIPITATION. AS TEMPERATURES
WARM...FREEZING RAIN WILL CHANGE TO RAIN BY LATER SATURDAY
MORNING...BUT CEILINGS WILL LIKELY REMAIN LOW THROUGH THE DAY.
OUTLOOK...MVFR CEILINGS AND VISIBILITIES WILL CONTINUE INTO THE
DAY ON SATURDAY AND POSSIBLY INTO SUNDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HICKMAN
NEAR TERM...JGL
SHORT TERM...HICKMAN
LONG TERM...NOVAK
AVIATION...HATZOS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
538 AM CST FRI JAN 2 2015
.UPDATE...
ISSUED AT 538 AM CST FRI JAN 2 2015
WATCHING A STRATUS DECK ADVECT EASTWARD ACROSS THE INTERSTATE 35
CORRIDOR OVER SOUTHERN MINNESOTA AND NORTH CENTRAL IOWA. THIS
DECK IS EXPECTED TO SPREAD INTO SOUTHEAST MINNESOTA AND NORTHEAST
IOWA THEN WE SHOULD SEE IT/S EASTWARD EXPANSION SLOW LATER THIS
MORNING AS 925 MB WINDS SWITCH FROM WESTERLY TO THE SOUTH. HAVE
INCREASED SKY COVER THROUGH LATE MORNING ALONG AND WEST OF THE
MISSISSIPPI RIVER TO ACOUNT FOR THIS EASTWARD EXPANSION IN CLOUD
COVER.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 301 AM CST FRI JAN 2 2015
CURRENTLY AS OF 09Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED A SHORTWAVE TROUGH OVER THE YUKON OF CANADA...A POTENT UPPER
TROUGH OVER NORTHERN BRITISH COLUMBIA...UPPER LOWS OVER ARIZONA AND
THE DENVER AREA...AND BROAD UPPER TROUGHING OVER EASTERN CANADA INTO
THE GREAT LAKES. WITH THE FORECAST AREA UNDER THE NORTHWEST FLOW ON
THE EDGE OF THIS UPPER TROUGHING...SUBSIDENCE AND DRYING HAS BEEN
OCCURRING. THIS HAS TRANSLATED INTO CLEARING SKIES IN THE WAKE OF A
SURFACE COLD FRONTAL PASSAGE DURING THE NIGHT. A BIT OF ARCTIC AIR
HAS BEEN SPILLING INTO NORTHERN WISCONSIN...NORTH OF HIGHWAY 29...
REFLECTED BY 925MB TEMPS DROPPING TO -12 TO -16C THERE AND SURFACE
TEMPERATURES IN THE SINGLE DIGITS ABOVE AND BELOW ZERO. READINGS ARE
MOSTLY IN THE TEENS ELSEWHERE IN THE FORECAST AREA. ONLY OTHER ITEM
OF NOTE WAS A LOOK AT PRECIPITABLE WATER VALUES FROM 00Z RAOBS. MOST
READINGS ACROSS THE CENTRAL/NORTHERN PLAINS AND OUR REGION WERE
BETWEEN 0.2 AND 0.35...FAIRLY DRY. HOWEVER...0.7-1 INCH VALUES WERE
PRESENT ACROSS THE SOUTHERN PLAINS AHEAD OF THE ARIZONA UPPER LOW.
MUCH OF THE SHORT TERM PERIOD IS QUIET THANKS TO THE DRY AIRMASS IN
PLACE REFLECTED BY 00Z RAOBS. HOWEVER...AS WE GET INTO THE AFTER
MIDNIGHT HOURS TONIGHT...THE 02.00Z GFS AND NAM SPREAD SOME LIGHT
QPF FROM THE SOUTH INTO CLAYTON/GRANT COUNTY AREA. THE 02.06Z
NAM/02.00Z ECMWF TAKE IT ONE STEP FURTHER AND SPREAD IT ALL THE WAY
THROUGH ABOUT THE EAST HALF OR MORE OF THE FORECAST AREA. MUCH OF
THIS QPF IS A RESULT OF AN ISENTROPIC LIFT / WARM ADVECTION REGIME
DEVELOPING DOWNSTREAM OF THE ARIZONA UPPER LOW...WHICH BY 12Z
SATURDAY IS PROGGED TO BE IN WEST TEXAS. ADDITIONALLY...WE HAVE THAT
UPPER LOW NEAR DENVER COMING THROUGH TO ADD IN SOME DPVA FORCING.
HAVE ADDED 20-40 PERCENT CHANCES INTO THE FORECAST FOR THIS FEATURE
AND THESE MAY NEED TO BE INCREASED LATER TODAY. MUCH OF THE LIFT IS
TAKING PLACE BETWEEN 10 KFT-15 KFT...BUT ENOUGH LOW LEVEL SATURATION
OCCURS TO ALLOW SNOW TO REACH THE SURFACE. IT SHOULD BE
NOTED...THOUGH...AS WE APPROACH 12Z THE ICE BEGINS TO EXITS THE
CLOUDS IN BOTH THE 02.00Z/06Z NAM AND GFS. SO...ANY LINGERING LIFT
APPROACHING THIS TIME COULD RESULT IN FREEZING DRIZZLE. HAVE ADDED
THIS POTENTIAL TO THE FORECAST. PROBABILITY FOR THIS FREEZING
DRIZZLE IS TOO LOW FOR AN ADVISORY AT THIS TIME.
WITH THE WARM ADVECTION REGIME DEVELOPING OVER THE NEXT 24 HOURS...
THE ARCTIC AIR TRYING TO SPILL INTO FAR NORTHERN SECTIONS OF THE
FORECAST AREA RIGHT NOW WILL STRUGGLE MAKING IT FARTHER SOUTH. IN
FACT...BY 00Z THIS EVENING...925MB TEMPS ALREADY ARE PROGGED FROM
-5C SOUTHWEST TO -9C NORTHEAST. WITH WHAT SHOULD BE A MOSTLY SUNNY
DAY...ANTICIPATE HIGHS CAN TOP OUT IN THE TEENS OVER TAYLOR/CLARK
COUNTIES TO THE 20S OVER THE REST OF THE SNOW PACK AREAS...AND LOW
30Z OVER SNOW FREE AREAS. WARM ADVECTION PERSISTS TONIGHT...WHICH
WITH CLOUDS INCREASING OVERNIGHT SHOULD HELP SOMEWHAT ON
TEMPERATURES. HOWEVER...WITH A MOSTLY CLEAR EVENING AND A WEAK
GRADIENT...READINGS COULD DROP INTO THE SINGLE DIGITS OVER
TAYLOR/CLARK TO THE TEENS TO LOW 20S ELSEWHERE.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 301 AM CST FRI JAN 2 2015
THE FOCUS FOR SATURDAY AND SATURDAY NIGHT CONTINUES TO REVOLVE
AROUND THE CURRENT UPPER LOW IN ARIZONA AND THE SHORTWAVE TROUGH
OVER BRITISH COLUMBIA. IT APPEARS THE MAIN ROLE OF THE BRITISH
COLUMBIA SHORTWAVE IS TO SERVE AS A KICKER FOR THE UPPER LOW. GOOD
MODEL CONSENSUS EXISTS FOR THE UPPER LOW TO TRACK THROUGH THE
DAVENPORT IA AREA AROUND 06Z SUNDAY AND INTO LOWER MICHIGAN BY 12Z
SUNDAY. HOWEVER...THE BRITISH COLUMBIA TROUGH DOES SPLIT APART WITH
A SHORTWAVE THAT COMES OFF IT WHICH MODELS BRING THROUGH THE
FORECAST AREA SATURDAY NIGHT. THAT SHORTWAVE EVENTUALLY PHASES WITH
THE UPPER LOW OVER LOWER MICHIGAN...RESULTING IN A DEEPENING SURFACE
LOW WELL OFF TO OUR EAST.
THE ISENTROPIC LIFT REGIME THAT DEVELOPED TONIGHT LOOKS TO PERSIST
THROUGH SATURDAY...THOUGH MAINLY FOCUSED OVER THE SOUTHEAST 1/3 TO
1/2 OF THE FORECAST AREA. THUS...THIS IS WHERE THE MAIN FOCUS FOR
PRECIPITATION EXISTS. AGAIN...BOTH THE 02.00Z NAM AND GFS POINT TO
WAVES OF ICE IN AND OUT OF THE CLOUDS...THUS THE FORECAST INCLUDES A
MENTION OF BOTH SNOW AND DRIZZLE/FREEZING DRIZZLE. WITH A GREATER
CHANCE FOR PRECIPITATION...MAY NEED AN ADVISORY FOR THIS WINTRY MIX
ASPECT. BEING DURING THE DAYTIME AND TEMPERATURES PERHAPS CLIMBING
ABOVE THE FREEZING MARK...THIS SHOULD HELP LIMIT ICE ACCUMULATION.
PRECIPITATION CHANCES INCREASE ACROSS THE ENTIRE FORECAST AREA
SATURDAY NIGHT WITH THE CROSSING OF THE SHORTWAVE AND BRUSH BY FROM
THE UPPER LOW. THE DEFORMATION SNOW BAND ACCOMPANYING THE NORTHWEST
SIDE OF THE DEEPENING SURFACE LOW MAY CLIP THE SOUTHEAST 1/3 OF THE
FORECAST AREA...THUS HIGHEST PRECIPITATION CHANCES AND QPF ARE
CONFINED THERE. PRECIPITATION SHOULD DIMINISH WEST TO EAST QUICKLY
LATE IN THE NIGHT AS SUBSIDENCE AND MUCH COLDER AND DRIER AIR ADVECT
IN. SNOWFALL AMOUNTS OVERALL HAVE COME DOWN QUITE A BIT WITH THE
02.00Z CYCLE...INCLUDING WITH THE 02.00Z ECMWF. THIS DECLINE IS A
COMBINATION OF THE AFOREMENTIONED WINTRY MIX AND MODELS NOT NEARLY
AS IMPRESSIVE WITH THE DEFORMATION BAND. IT SHOULD BE NOTED THAT THE
02.06Z NAM AND TO SOME DEGREE THE 02.00Z ECMWF HAVE THE DEFORMATION
BAND MISS MUCH OF THE FORECAST AREA...WITH MUCH OF THE PRECIP FOCUS
ON THE SNOW ACCOMPANYING THE SHORTWAVE. IF THIS HAPPENS...EVEN LESS
SNOW WILL FALL OVER THE SOUTHEAST 1/2 OF THE AREA.
FOCUS FOR THE REST OF THE FORECAST TURNS TO ARCTIC AIR. WE HAVE TWO
BIG BLASTS TO CONTEND WITH...THE FIRST COMING IN LATE SATURDAY NIGHT
AND THE SECOND COMING IN TUESDAY NIGHT. BOTH BLASTS HAVE A 35-45 KT
925MB WINDS CORE COMING ACROSS...WHICH MEANS THERE IS POTENTIAL WIND
SPEEDS COULD TRY TO APPROACH ADVISORY CRITERIA. HOWEVER...THE ARCTIC
AIR ACCOMPANYING THE WIND WILL FORCE WIND CHILL AS THE BIGGER
HAZARD. HOW COLD WE GET WILL DEPEND SOMEWHAT ON HOW MUCH SNOW WE GET
OVER THE NEXT FEW DAYS GIVEN THE LACK OF SNOW OVER THE SOUTHEAST
HALF OF THE FORECAST AREA. DETAILS...925MB TEMPS FALL FROM -4 TO -9C
AT 06Z SUNDAY TO -23 TO -26C BY 00Z MONDAY AND -26 TO -30C BY 12Z
MONDAY...WHICH MEANS TEMPERATURES SHOULD JUST FALL THROUGH THE DAY
SUNDAY...WITH MUCH OF THE NORTHWEST HALF BELOW ZERO FOR MUCH OF THE
DAY. WIND CHILL ADVISORIES LOOK LIKELY FOR THE NORTHWEST HALF ON
SUNDAY...EXPANDING EVERYWHERE SUNDAY NIGHT INTO MONDAY WITH MAYBE
SOME WARNINGS FOR TAYLOR/CLARK AND SOUTHEAST MN. THERE IS A BRIEF
WARM UP FOR MONDAY NIGHT INTO TUESDAY AS A NORTHWEST FLOW SHORTWAVE
TROUGH AND SYSTEM MOVE THROUGH THE REGION. PRECIPITATION CHANCES ARE
INCLUDED FOR THE SNOW ASPECT FOR THIS SYSTEM...WHICH COULD BE
ADVISORY WORTHY FOR SOME FLUFFY SNOW. THEN THE NEXT ARCTIC BLAST
FOLLOWS IN ITS WAKE FOR TUESDAY NIGHT AS A VERY DEEP TROUGH DROPS
INTO THE WESTERN GREAT LAKES. 925MB TEMPS PLUMMET FROM -14 TO -18C
AT 18Z TUESDAY TO AGAIN -26 TO -30C BY 12Z WEDNESDAY. WIND CHILL
ADVISORIES AND WARNINGS ARE LIKELY TO BE NEEDED. TEMPERATURES MAY
STRUGGLE TO CLIMB MUCH WEDNESDAY. LOWERED HIGHS SOME AND THESE MAY
NEED FURTHER LOWERING. ON A POSITIVE NOTE...MASSIVE WARM ADVECTION
IS PROGGED FOR WEDNESDAY NIGHT AND THURSDAY AS THE DEEP TROUGH MOVES
WELL OFF TO THE EAST. SO HIGHS SHOULD REBOUND NICELY FOR
THURSDAY...BUT STILL BELOW NORMAL.
INTERESTINGLY...THIS ARCTIC OUTBREAK FOR SUNDAY...MONDAY AND
WEDNESDAY ENDS UP BEING AT EXACTLY THE SAME TIME AS LAST YEARS
ARCTIC OUTBREAK. WIND CHILLS MAY NOT BE AS COLD...SINCE 925MB
TEMPS ARE A LITTLE WARMER THAN LAST YEARS ARCTIC OUTBREAK...BUT
ITS STILL LOOKS DANGEROUSLY COLD FOR SOME OF THIS TIME.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 538 AM CST FRI JAN 2 2015
AN MVFR STRATUS DECK WILL MOVE ACROSS THE TAF SITES THIS MORNING
BUT SHOULD THEN SHIFT NORTH AS 925 MB WINDS BECOME SOUTHERLY. PLAN
ON MVFR CONDITIONS AT TIMES THIS MORNING IN THE STRATUS THEN WE
SHOULD SEE CONDITIONS IMPROVE TO VFR. MVFR/IFR CONDITIONS ARE
EXPECTED TONIGHT AS LOW PRESSURE APPROACHES THE REGION AND LOW
LEVEL MOISTURE INCREASES. PLAN ON CEILINGS LOWERING TO 700 FT AT
KRST AROUND 10Z AND CEILINGS LOWERING TO 2000 FT AT KLSE AROUND
06Z. THERE MAY ALSO BE SOME VISIBILITY RESTRICTIONS IN FOG LATER
TONIGHT BUT CONFIDENCE IS LOW ON THE FOG IMPACTING THE TAF SITES.
THE MAIN IMPACT WILL BE FROM THE LOW STRATUS PRODUCING IFR
CONDITIONS AT TIMES...MAINLY AT KRST. THE IFR STRATUS MAY ALSO
IMPACT KLSE AFTER 09Z.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...WETENKAMP
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...WETENKAMP
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1013 AM MST FRI JAN 2 2015
.UPDATE...
ISSUED AT 1013 AM MST FRI JAN 2 2015
CLOUD DECK ALONG AND NORTH OF I-70/I-76 IS STILL INTACT...AND
RADAR/OBS POINT TO JUST A FEW FLURRIES IN NORTHERN WELD COUNTY.
CLOUD DECK IS SHOWING SLOW SIGNS OF BREAKING AND WITH FLOW ALOFT
FINALLY TURNING MORE WESTERLY THIS AFTERNOON IT SHOULD BE ABLE TO
PULL OFF THE FRONT RANGE AND ERODE. HAVE ADJUSTED LATEST FORECAST
THIS WAY FOR MORE CLOUDS INTO EARLY AFTERNOON THEN SOME CLEARING.
ATTENTION WILL THEN TURN TOWARD TOMORROWS COLD FRONT. SNOW
EXPECTED TO DEVELOP SHORTLY BEHIND THE FRONT WITH BLOWING SNOW
LIKELY BEING A PROBLEM AS WINDS INCREASE. WILL ANALYZE FULL SUITE
OF 12Z GUIDANCE BEFORE ISSUING APPROPRIATE HIGHLIGHTS.
UPDATE ISSUED AT 734 AM MST FRI JAN 2 2015
CLOUD BAND NORTH OF I-70 IS BARELY MOVING AT THIS POINT SO ADDED
MORE CLOUDS TO THE MORNING FORECAST ESPECIALLY OVER THE NORTHERN
HALF OF THE FORECAST AREA. THERE SHOULD BE BREAKAGE BY MID DAY PER
LATEST RAP OUTPUT...BUT COULD LINGER OVER THE NORTHEAST CORNER
INTO THE AFTERNOON. ALSO ADDED A FEW SNOW SHOWERS NEAR THE WYOMING
BORDER PER LATEST OBS AND RADAR RETURNS.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 400 AM MST FRI JAN 2 2015
AN UPPER LOW JUST SOUTH OF THE FOUR CORNERS AND A SECONDARY UPPER
LOW OVER NORTHEAST COLORADO ARE CONNECTED BY AN ELONGATED UPPER
TROUGH. LOW CLOUDS AND POCKETS OF LIGHT SNOWFALL ACROSS NORTHERN
SECTIONS OF THE CWA COINCIDE WITH A +70KT JET MAXIMA ROUNDING THE
NORTHWEST SIDE OF THE UPPER LOW OVER NERN COLORADO. LOW IS EVIDENT
ON IR AND H20 VAPOR SATL IMAGERY. MODELS SHOW THIS NORTHERN LOW
AND ITS ACCOMPANYING CLOUD BAND AND LIGHT PRECIP TRACKING
NORTHEAST AWAY FROM THE FRONT RANGE AND ACROSS NEBRASKA THIS
MORNING. ONCE OUT OF THE AREA...SHOULD SEE CLEARING MOST AREAS AS
DRIER SLIGHTLY WARMER AIR ALOFT ADVECTS IN FROM THE NORTHWEST.
EXPECT HIGHS TODAY TO BE 8-12F WARMER THAN YESTERDAY.
TONIGHT...AFTER CLEAR SKIES AND LIGHT BREEZES IN THE
EVENING...MID AND HIGH CLOUDS ARE EXPECTED TO ENCROACH UPON THE
NRN MTN RANGES AFTER MIDNIGHT IN ADVANCE OF A CLIPPER WEATHER
SYSTEM RACING DOWN FROM BRITISH COLUMBIA. COULD POSSIBLY SEE A
LIGHT SNOW SHOWERS REACHING THE PARK AND GORE RANGES BEFORE
MORNING. IN ADDITION...STRENGTHENING NORTHWEST FLOW ALOFT WILL
CAUSE WLY WINDS TO INCREASE IN SPEED ON MTN RIDGES AND UPPER EAST
SLOPES OF THE FRONT RANGE AFTER MIDNIGHT. IN THESE AREAS COULD
SEE GUSTS IN THE 40-50 MPH RANGE. OTHERWISE IT WILL REMAIN DRY AT
LOWER ELEVATIONS.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 400 AM MST FRI JAN 2 2015
MAIN CONCERN WILL BE IMPACT FROM THE UPPER LEVEL TROF WHICH WILL
MOVE RAPIDLY FROM THE NORTHERN ROCKIES AND THROUGH COLORADO ON
SATURDAY. ASSOCIATED COLD FRONT WILL MOVE SOUTHWARD OVER THE
PLAINS MIDDAY ON SATURDAY WITH INCREASING NORTHERLY UPSLOPE FLOW
AND MOISTURE DURING THE AFTERNOON. MODEST QG UPWARD FORCING/JET
DYNAMICS AND RATHER STEEP LAPSE RATES WILL RESULT IN A WINDOW OF
SNOW SATURDAY AFTERNOON AND EVENING OVER MUCH OF CWA. GIVEN THE
STEEPENING LAPSE RATES AND INFLUX OF COLDER AIR...COULD SEE A FEW
HOURS OF MODERATE TO HEAVY SNOW OVER PORTIONS OF THE PLAINS.
LATEST GFS/NAM SHOWING 1-4 INCHES OF SNOW WHILE EUROPEAN A BIT
LESS WITH 1-2 INCHES. WITH MORE MODEL CONSISTENCY IN THE RUN TO
RUNS SHOWING UP IN THE PAST FEW DAYS...WILL BOOST POPS UP TO
LIKELY FOR MUCH OF THE AREA.
BEHIND THE DISTURBANCE...THE FLOW WILL INCREASE FROM THE
NORTHWEST WITH SOME DEVELOPMENT OF DOWNSLOPE WINDS OVER THE
MOUNTAINS AND EAST SLOPES FROM SUNDAY THROUGH TUESDAY. GUSTS IN
THE 50-70 MPH RANGE IS POSSIBLE SO WILL HAVE TO WATCH FOR
POTENTIAL FOR HIGH WINDS IN THESE PERIODS. WITH THE DOWNSLOPE
WINDS...TEMPERATURES WILL WARM TO SEASONAL NORMALS ACROSS LOWER
ELEVATIONS. LATEST LONG RANGE MODELS ARE NOW SHOWING ANOTHER
INFLUX OF COLDER AIR AND CHANCE OF PRECIP LATE TUESDAY AFTERNOON
AND NIGHT. WILL ADD SOME LOW POPS OVER THE FAR NORTHEAST CORNER IN
PROXIMITY TO THE UPPER JET. WITH THIS FLOW PATTERN...THE NORTHERN
MOUNTAINS WILL BE SUSCEPTIBLE TO A CHANCE OF LIGHT SNOW THROUGH
TUESDAY.
&&
.AVIATION...(FOR THE TAFS THROUGH 18Z SATURDAY MORNING)
ISSUED AT 1013 AM MST FRI JAN 2 2015
SCATTERED CLOUDS AROUND 5000-7000 FT AGL AND A SCT-BKN HIGHER
DECK AROUND 10000-12000 FEET WILL DECREASE 21Z-00Z. SOUTH/
SOUTHWEST WINDS AROUND 12 KNOTS AT KDEN WILL DECREASE THROUGH 20Z
AND TRY TO TRANSITION MORE SOUTHEASTERLY. WINDS AT KDEN...KAPA AND
KBJC ARE EXPECTED TO RETURN TO A SOUTH-SOUTHWEST DIRECTION AT
6-12KTS BY 00Z-02Z AND REMAIN THERE OVERNIGHT UNDER CLEAR TO
MOSTLY CLEAR SKIES.
ATTENTION THEN TURNS TOWARD COLD FRONT EXPECTED TO REACH THE AREA
SATURDAY. MOST LIKELY TIME OF FROP IS FROM 16Z-18Z WITH 15-20G25-30KT
NORTH WINDS. SNOW WILL ALSO DEVELOP A FEW HOURS BEHIND THE FRONT
WITH IFR CEILINGS AND VISIBILITIES LIKELY SATURDAY AFTERNOON.
BLOWING SNOW MAY FURTHER REDUCE VISIBILITIES ESPECIALLY AT KDEN
AND KAPA WHERE STRONGER WINDS AND MORE FRESH SNOW COVER EXISTS.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BARJENBRUCH
SHORT TERM...BAKER
LONG TERM...ENTREKIN
AVIATION...BARJENBRUCH
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1223 PM EST FRI JAN 2 2015
.SYNOPSIS...
MOISTURE WILL INCREASE ACROSS THE AS A LOW PRESSURE SYSTEM AND
COLD FRONT APPROACHES THE REGION FROM THE WEST. THE CHANCE OF RAIN
WILL INCREASE THROUGH THE WEEKEND WITH BEST CHANCES SUNDAY
AFTERNOON AS A COLD FRONT MOVES ACROSS THE AREA. COLD HIGH
PRESSURE AND DRY CONDITIONS WILL BUILD BACK INTO THE REGION SUNDAY
NIGHT AND MONDAY THROUGH MID-WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NEAR TERM...
WATER VAPOR IMAGERY SHOWING THE UPPER LOW OVER THE DESERT
SOUTHWEST STARTING TO CLOSE OFF WHILE AN UPPER HIGH OVER CUBA
RIDGES INTO THE SOUTHEASTERN STATES. SURFACE HIGH PRESSURE
CONTINUES TO BE CENTERED OVER THE REGION WITH GENERALLY LIGHT AND
VARIABLE WINDS.
REGIONAL RADAR SHOWING A LARGE AREA OF PRECIPITATION MOVING ACROSS
ALABAMA INTO NORTHWEST GEORGIA ASSOCIATED WITH WEAK SHORTWAVE ENERGY
ROUNDING THE TOP OF THE UPPER RIDGE AXIS...AIDED BY ISENTROPIC
LIFTING OF THE SOUTHWESTERLY FLOW ATOP THE COOLER SURFACE LAYER.
SOME SCATTERED SHOWERS HAVE WORKED INTO THE CSRA AND FAR WESTERN
MIDLANDS LATE THIS MORNING BUT KEEP DIMINISHING AS THEY MOVE
EASTWARD INTO RELATIVELY DRIER AIR AND AWAY FROM THE SOURCE OF LIFT
FURTHER TO THE WEST. LATEST HRRR RUNS SHOW THE AREA OF
PRECIPITATION TO THE WEST MOVING INTO THE WESTERN MIDLANDS BY THIS
AFTERNOON AND WILL CARRY HIGHEST POPS THERE WITH A GRADIENT TO LOWER
POPS FURTHER SOUTH AND EAST. OVERALL RAINFALL AMOUNTS EXPECTED TO
BE LIGHT AS THE PRECIPITATION IS FALLING OUT OF MAINLY MID LEVEL
CLOUDS...THOUGH THE CLOUD DECKS ARE EXPECTED TO LOWER THROUGH THE
AFTERNOON FROM WEST TO EAST.
VISIBLE IMAGERY SHOWING GENERALLY THIN HIGH CLOUDS ACROSS THE
SOUTHEASTERN MIDLANDS WHICH HAS ALLOWED TEMPS TO RISE MORE
QUICKLY THERE THAN FURTHER TO THE WEST WHERE THICKER CLOUDS ARE
PRESENT. RAISED MAX TEMPS A BIT TO ACCOUNT FOR THIS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
MODELS STRENGTHEN WEDGE TONIGHT INTO SATURDAY WITH THE SURFACE
RIDGE CENTER IN FAVORABLE LOCATION IN THE NORTHEASTERN STATES
EXTENDING SOUTHWEST ACROSS THE CAROLINAS. STRONG WARM ADVECTION
AND MOISTURE TRANSPORT JUST ABOVE THE WEDGE WILL BEGIN TO ERODE
THE WEDGE FROM THE SOUTH LATE SATURDAY AND SATURDAY NIGHT. MODELS
LIFT WARM FRONT NORTH THROUGH THE CWA LATE SATURDAY NIGHT. MIN
TEMPS SATURDAY NIGHT WILL LIKELY OCCUR IN THE EVENING WITH RISING
TEMPS AFTER MIDNIGHT. STRONG WARM MOIST ADVECTION CONTINUES AHEAD
OF AN APPROACHING COLD FRONT ON SUNDAY. TEMPERATURES ARE FORECAST
TO RISE INTO THE 70S WITH MOS DEWPOINTS INTO THE LOWER 60S.
INSTABILITY WILL INCREASE JUST AHEAD OF THE FRONT WHICH IS PROGGED
TO PASS THROUGH THE AREA BETWEEN 18Z AND 00Z SUNDAY. GFS IS ABOUT
3-H FASTER THAN NAM WITH FRONTAL PASSAGE. LI/S AHEAD OF THE FRONT
REACH -1 TO -3 WITH STRONG SHEAR AND A 5KT WIND SPEED IN THE
50-55KT RANGE.
POPS WILL BE GENERALLY IN THE 40-60 PERCENT RANGE
TONIGHT AND SATURDAY WITH THE STRONG WAA...DECREASING SIGHTLY TO
THE 30-50 PERCENT RANGE SATURDAY NIGHT AS WE TRANSITION TO THE
WARM SECTOR...THEN INCREASE ON SUNDAY TO NEAR 100 PERCENT IN A
CONVECTIVE LINE AHEAD OF THE COLD FRONT. HAVE THUNDER IN THE
FORECAST. WITH THE STRONG SHEAR...SOME INSTABILITY AND A STRONG
LOW LEVEL WIND FIELD WE WILL NEED TO MONITOR THE SITUATION FOR THE
POTENTIAL OF SEVERE WEATHER.
SUNDAY NIGHT SKIES WILL CLEAR...WINDS WILL TURN TO THE WEST
NORTHWEST AND TEMPS WILL COOL DOWN INTO THE LOWER 40S BEHIND THE
COLD FRONT.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
GFS...ECMWF...CMC MODELS SIMILAR WITH A COUPLE OF UPPER TROFS
AFFECTING THE FORECAST AREA NEXT WEEK. SURFACE HIGH PRESSURE WITH
ARCTIC AIR DIVES SOUTH WITH THE SECOND TROF BRINGING MUCH COLDER
TEMPERATURES BY MIDWEEK. TEMPERATURES OVERALL WILL BE BELOW
NORMAL...ESPECIALLY WEDNESDAY ON. NO PRECIPITAION EXPECTED.
&&
.AVIATION /17Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS EXPECTED THROUGH MUCH OF THE PERIOD...WITH
DIMINISHING CONDITIONS AFTER 06Z.
VFR CONDITIONS TO START THE FORECAST PERIOD WITH GENERALLY OVERCAST
MID LEVEL CLOUDS BUT COULD SEE SOME LOWER VFR CEILINGS IN PATCHES OF
RAIN THAT WILL BE MOVING INTO THE AREA FROM THE WEST...ASSOCIATED
WITH WEAK ISENTROPIC LIFT. LIGHT AND VARIABLE WINDS THROUGHOUT THE
FORECAST PERIOD ALTHOUGH A GENERAL PREVAILING NORTHEASTERLY
DIRECTION IS EXPECTED LATE TONIGHT INTO SATURDAY MORNING AS A COLD
AIR DAMMING WEDGE DEVELOPS. AS THE WEDGE DEVELOPS LATE
TONIGHT...CEILINGS ARE EXPECTED TO DROP INTO MVFR RANGE AFTER 06Z
THEN FALL INTO IFR CATEGORY AFTER AROUND 12Z FOR ALL TERMINALS.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS FOR BOTH CEILINGS AND
VISIBILITIES EXPECTED SATURDAY AFTERNOON AND NIGHT IN THE WEDGE THEN
SOME IMPROVEMENT EXPECTED ON SUNDAY. MORE RESTRICTIONS POSSIBLE WITH
A COLD FRONT SUNDAY AFTERNOON/EVENING. THUNDERSTORMS MAY IMPACT TAF
SITES SUNDAY AFTERNOON.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
99/87
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1156 AM EST FRI JAN 2 2015
.SYNOPSIS...
MOISTURE WILL INCREASE ACROSS THE AS A LOW PRESSURE SYSTEM AND
COLD FRONT APPROACHES THE REGION FROM THE WEST. THE CHANCE OF RAIN
WILL INCREASE THROUGH THE WEEKEND WITH BEST CHANCES SUNDAY
AFTERNOON AS A COLD FRONT MOVES ACROSS THE AREA. COLD HIGH
PRESSURE AND DRY CONDITIONS WILL BUILD BACK INTO THE REGION SUNDAY
NIGHT AND MONDAY THROUGH MID-WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NEAR TERM...
WATER VAPOR IMAGERY SHOWING THE UPPER LOW OVER THE DESERT
SOUTHWEST STARTING TO CLOSE OFF WHILE AN UPPER HIGH OVER CUBA
RIDGES INTO THE SOUTHEASTERN STATES. SURFACE HIGH PRESSURE
CONTINUES TO BE CENTERED OVER THE REGION WITH GENERALLY LIGHT AND
VARIABLE WINDS.
REGIONAL RADAR SHOWING A LARGE AREA OF PRECIPITATION MOVING ACROSS
ALABAMA INTO NORTHWEST GEORGIA ASSOCIATED WITH WEAK SHORTWAVE ENERGY
ROUNDING THE TOP OF THE UPPER RIDGE AXIS...AIDED BY ISENTROPIC
LIFTING OF THE SOUTHWESTERLY FLOW ATOP THE COOLER SURFACE LAYER.
SOME SCATTERED SHOWERS HAVE WORKED INTO THE CSRA AND FAR WESTERN
MIDLANDS LATE THIS MORNING BUT KEEP DIMINISHING AS THEY MOVE
EASTWARD INTO RELATIVELY DRIER AIR AND AWAY FROM THE SOURCE OF LIFT
FURTHER TO THE WEST. LATEST HRRR RUNS SHOW THE AREA OF
PRECIPITATION TO THE WEST MOVING INTO THE WESTERN MIDLANDS BY THIS
AFTERNOON AND WILL CARRY HIGHEST POPS THERE WITH A GRADIENT TO LOWER
POPS FURTHER SOUTH AND EAST. OVERALL RAINFALL AMOUNTS EXPECTED TO
BE LIGHT AS THE PRECIPITATION IS FALLING OUT OF MAINLY MID LEVEL
CLOUDS...THOUGH THE CLOUD DECKS ARE EXPECTED TO LOWER THROUGH THE
AFTERNOON FROM WEST TO EAST.
VISIBLE IMAGERY SHOWING GENERALLY THIN HIGH CLOUDS ACROSS THE
SOUTHEASTERN MIDLANDS WHICH HAS ALLOWED TEMPS TO RISE MORE
QUICKLY THERE THAN FURTHER TO THE WEST WHERE THICKER CLOUDS ARE
PRESENT. RAISED MAX TEMPS A BIT TO ACCOUNT FOR THIS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
MODELS STRENGTHEN WEDGE TONIGHT INTO SATURDAY WITH THE SURFACE
RIDGE CENTER IN FAVORABLE LOCATION IN THE NORTHEASTERN STATES
EXTENDING SOUTHWEST ACROSS THE CAROLINAS. STRONG WARM ADVECTION
AND MOISTURE TRANSPORT JUST ABOVE THE WEDGE WILL BEGIN TO ERODE
THE WEDGE FROM THE SOUTH LATE SATURDAY AND SATURDAY NIGHT. MODELS
LIFT WARM FRONT NORTH THROUGH THE CWA LATE SATURDAY NIGHT. MIN
TEMPS SATURDAY NIGHT WILL LIKELY OCCUR IN THE EVENING WITH RISING
TEMPS AFTER MIDNIGHT. STRONG WARM MOIST ADVECTION CONTINUES AHEAD
OF AN APPROACHING COLD FRONT ON SUNDAY. TEMPERATURES ARE FORECAST
TO RISE INTO THE 70S WITH MOS DEWPOINTS INTO THE LOWER 60S.
INSTABILITY WILL INCREASE JUST AHEAD OF THE FRONT WHICH IS PROGGED
TO PASS THROUGH THE AREA BETWEEN 18Z AND 00Z SUNDAY. GFS IS ABOUT
3-H FASTER THAN NAM WITH FRONTAL PASSAGE. LI/S AHEAD OF THE FRONT
REACH -1 TO -3 WITH STRONG SHEAR AND A 5KT WIND SPEED IN THE
50-55KT RANGE.
POPS WILL BE GENERALLY IN THE 40-60 PERCENT RANGE
TONIGHT AND SATURDAY WITH THE STRONG WAA...DECREASING SIGHTLY TO
THE 30-50 PERCENT RANGE SATURDAY NIGHT AS WE TRANSITION TO THE
WARM SECTOR...THEN INCREASE ON SUNDAY TO NEAR 100 PERCENT IN A
CONVECTIVE LINE AHEAD OF THE COLD FRONT. HAVE THUNDER IN THE
FORECAST. WITH THE STRONG SHEAR...SOME INSTABILITY AND A STRONG
LOW LEVEL WIND FIELD WE WILL NEED TO MONITOR THE SITUATION FOR THE
POTENTIAL OF SEVERE WEATHER.
SUNDAY NIGHT SKIES WILL CLEAR...WINDS WILL TURN TO THE WEST
NORTHWEST AND TEMPS WILL COOL DOWN INTO THE LOWER 40S BEHIND THE
COLD FRONT.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/... THE COLD FRONT WILL MOVE EAST
OF THE FORECAST AREA SUNDAY NIGHT...ALLOWING HIGH PRESSURE TO ONCE
AGAIN BUILD BACK INTO THE REGION FOR THE EARLY PART OF NEXT WEEK.
MODELS BRING ANOTHER STRONG ARCTIC HIGH DOWN INTO THE CENTRAL
PLAINS BY THE MIDDLE OF NEXT WEEK...WHICH WOULD BRING A DRY COLD
FRONT INTO THE REGION ALONG WITH COLDER TEMPERATURES. SO AT THIS
TIME IT LOOKS TO BE DRY FOR THE MONDAY THROUGH THURSDAY PERIOD
WITH BELOW NORMAL TEMPERATURES THROUGH THE PERIOD.
&&
.AVIATION /16Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS EXPECTED THROUGH MUCH OF THE PERIOD...WITH
DIMINISHING CONDITIONS AFTER 06Z.
VFR CONDITIONS TO START THE FORECAST PERIOD WITH GENERALLY OVERCAST
MID LEVEL CLOUDS BUT COULD SEE SOME LOWER VFR CEILINGS IN PATCHES OF
RAIN THAT WILL BE MOVING INTO THE AREA FROM THE WEST...ASSOCIATED
WITH WEAK ISENTROPIC LIFT. LIGHT AND VARIABLE WINDS THROUGHOUT THE
FORECAST PERIOD ALTHOUGH A GENERAL PREVAILING NORTHEASTERLY
DIRECTION IS EXPECTED LATE TONIGHT INTO SATURDAY MORNING AS A COLD
AIR DAMMING WEDGE DEVELOPS. AS THE WEDGE DEVELOPS LATE
TONIGHT...CEILINGS ARE EXPECTED TO DROP INTO MVFR RANGE AFTER 06Z
THEN FALL INTO IFR CATEGORY AFTER AROUND 12Z FOR ALL TERMINALS.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS FOR BOTH CEILINGS AND
VISIBILITIES EXPECTED SATURDAY AFTERNOON AND NIGHT IN THE WEDGE THEN
SOME IMPROVEMENT EXPECTED ON SUNDAY. MORE RESTRICTIONS POSSIBLE WITH
A COLD FRONT SUNDAY AFTERNOON/EVENING. THUNDERSTORMS MAY IMPACT TAF
SITES SUNDAY AFTERNOON.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS JACKSON KY
307 PM EST FRI JAN 2 2015
.UPDATE...
ISSUED AT 1248 PM EST FRI JAN 2 2015
OVER THE LAST FEW HOURS...WHAT REPORTS OF PRECIP WE HAVE HAD IN OR
NEAR THE AREA HAS BEEN IN THE FORM OF RAIN...EVEN FOR LOCATIONS
SEVERAL COUNTIES TO OUR NORTH. WITH SURFACE TEMPS 35 DEGREES OR ABOVE
IN OUR NORTHERN COUNTIES...WENT AHEAD AND TOOK OUT MENTION OF ANY
FREEZING PRECIP FOR THE REMAINDER OF THE AFTERNOON. IT SEEMS AS
THOUGH MOST OF THE NEIGHBORING OFFICES ARE LETTING THEIR FROZEN
PRECIP FALL OUT OF THE FORECAST AS WELL. WAS A BIT CONCERNED ABOUT
THE ONGOING RADAR RETURNS THAT ARE MOVING EASTWARD AND INTO OUR CWA.
EVEN THOUGH MOST OF THESE APPEAR LIGHT...AND MAY NOT MAKE IT TO THE
SURFACE...THOUGHT IT BEST TO BE COVERED AND WENT AHEAD AND
INTRODUCED SLIGHT CHANCES FOR RAIN FOR MUCH OF THE CWA OVER THE NEXT
COUPLE OF HOURS. THIS IS STILL A PRECURSOR TO THE HEAVIER RAIN WHICH
SITS TO OUR WEST AND OUR SOUTH...AND IS STILL SET TO MOVE INTO THE
REGION LATER THIS EVENING/OVERNIGHT.
UPDATE ISSUED AT 1011 AM EST FRI JAN 2 2015
WENT AHEAD AND KEPT THE MENTION OF SLEET AND SNOW MIXING IN WITH RAIN
ACROSS THE NORTHERN PORTION OF THE CWA FOR THE NEXT COUPLE OF HOURS.
TEMPERATURES ARE STILL HOVERING IN THE 33 TO 35 DEGREE RANGE
HERE...BUT MOST OF THE AIR/MOISTURE ALOFT SHOULD STILL BE BELOW FREEZING.
ALSO BUMPED UP POPS IN THIS LOCATION FOR THE NEXT SEVERAL HOURS AS
WELL...AS ISOLATED TO SCATTERED LIGHT SHOWERS CONTINUE TO MOVE FROM
WEST TO EAST ACROSS NORTHERN KY. OTHER REFLECTIVITIES ARE CONTINUING
TO SHOW UP ACROSS THE WESTERN PORTION OF THE CWA MOVING EASTWARD AS
WELL. SO FAR...THE LATEST OBS ARE NOT SHOWING ANY OF THIS MOISTURE
ACTUALLY HITTING THE GROWN...BUT THOUGHT IT BEST TO GO AHEAD AND
INCLUDE THE MENTION OF SLIGHT CHANCES FOR PRECIP OVER THE NEXT FEW
HOURS ACROSS THE WESTERN CWA IN CASE SOMETHING IS ABLE TO WET BULB TO
THE SURFACE. ANY ICE POTENTIAL SHOULD BE OUT OF THE NORTHERN CWA BY
18Z THIS AFTERNOON AS TEMPERATURES CONTINUE TO SLOWLY RISE. THE NEXT
WAVE OF RAIN IS STILL EXPECTED TO ENTER INTO THE SOUTHERN CWA BY THIS
AFTERNOON.
UPDATE ISSUED AT 750 AM EST FRI JAN 2 2015
THE MORNING IS UNFOLDING MOSTLY AS EXPECTED...BUT THE LIGHT PCPN
NORTH OF THE MOUNTAIN PARKWAY IS MAKING ITS WAY TO THE SFC MORE
EFFECTIVELY THAN INITIALLY EXPECTED WHILE TO THE SOUTH THE INBOUND
PCPN HAS BEEN SLOWER TO ARRIVE. HAVE UPDATED THE NEXT SEVERAL HOURS
FOR THESE ADJUSTMENTS TAKING INTO ACCOUNT THE LATEST HRRR SCENARIO.
ALSO FINE TUNED THE T AND TD GRIDS PER THE LATEST OBS AND TRENDS.
THESE HAVE BEEN SENT TO THE NDFD AND WEB SERVERS.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 340 AM EST FRI JAN 2 2015
08Z SFC ANALYSIS SHOWS HIGH PRESSURE FADING OVER EASTERN KENTUCKY IN
ADVANCE OF A DEVELOPING WX SYSTEM TO THE SOUTHWEST AND AN AREA OF LOW
PRESSURE OFF TO THE NORTHEAST. THE CLOUDS ASSOCIATED WITH THE
SOUTHWEST SYSTEM HAVE OVERSPREAD THE AREA WITH POCKETS OF LIGHT PCPN
SHOWING UP ON THE REGIONAL RADAR...MAINLY SOUTH OF THE STATE
BORDER...THOUGH SOME RETURNS HAVE DEVELOPED ALONG INTERSTATE 64 IN
CENTRAL KENTUCKY...IN LINE WITH THE LATEST HRRR. THROUGH EAST
KENTUCKY TEMPERATURES ARE FAIRLY UNIFORM IN THE MID 30S WHILE
DEWPOINTS ARE GENERALLY IN THE MID 20S. DEW POINT DEPRESSIONS ON THE
ORDER OF 10 DEGREES WILL LEAD TO A CONCERN FOR WETBULBING WITH ANY
EARLY PCPN THIS MORNING THAT SHOULD RESULT IN PATCHES OF SLEET ALONG
WITH THE LIGHT RAIN. WILL CONTINUE TO DEPICT THIS IN THE GRIDS AND
MENTION IT IN THE HWO AND ZONES...THOUGH ANY IMPACTS ARE EXPECTED TO
BE MINIMAL GIVEN PAVEMENT TEMPERATURES ABOVE FREEZING THROUGH THE
EASTERN PARTS OF THE STATE. WINDS REMAIN LIGHT FROM THE SOUTHWEST
THROUGH THE AREA EARLY THIS MORNING.
THE MODELS ARE IN GOOD AGREEMENT ALOFT FOR THE SHORT TERM PORTION OF
THE FORECAST AS THEY ALL SHOW THE SOUTHWESTERN CLOSED LOW GETTING
PARTIALLY PICKED UP BY THE NORTHERN STREAM LATER TODAY. THIS PROCESS
RELEASES A BATCH OF ENERGY AND LOWER HEIGHTS INTO THE CENTRAL PLAINS
BY EVENING WHILE A LARGER PORTION STAYS SEPARATE OVER SOUTHERN NEW
MEXICO. THE EXPELLED NORTHERN WAVE IS QUICKLY ABSORBED INTO THE
LARGER FLOW AND SPREAD OVER THE CENTRAL GREAT LAKES BY MIDDAY
SATURDAY WHILE THE MAIN LOW IS KICKED EAST BY SOME ENERGY RIDING INTO
ITS BACKSIDE LATER SATURDAY. AHEAD OF THESE WAVES...BROAD SOUTHWEST
FLOW WILL SEND WARMER AND MORE MOIST AIR INTO THE TENNESSEE AND OHIO
VALLEYS TODAY THROUGH SATURDAY. GIVEN THE MODEL AGREEMENT HAVE
FOLLOWED THE HIGHER RESOLUTION NAM12 AND HRRR MOST CLOSELY.
SENSIBLE WEATHER WILL FEATURE THE NET RESULT OF A MOISTENING
ENVIRONMENT AND A DEVELOPING SFC LOW TO THE SOUTHWEST...RAIN CHANCES
MOVING IN FROM SOUTHWEST TO NORTHEAST TODAY. THE BETTER CHANCES
ARRIVE AFTER 18Z FOR THE BULK OF THE JKL CWA ALLOWING THE WARMER AIR
TO BRING UP TEMPERATURES WHILE DEWPOINTS CLIMB ABOVE FREEZING MAKING
ALL THE PCPN LIQUID AFTER THE EARLY MORNING POCKETS OF LIGHT MIXED
PCPN. THE REAL SURGE OF SHOWERS WILL ARRIVE LATER TONIGHT AS A
DEVELOPING WARM FRONT LIFTS INTO THE AREA AND PROVIDES A GOOD
FOCUSING MECHANISM FOR THE INCREASINGLY MOIST AIR. BY DAWN SATURDAY
THE DEEPENING SFC LOW OVER THE LOWER MISSISSIPPI VALLEY WILL LIFT ITS
WARM FRONT NORTH OF THE AREA PLACING OUR AREA IN THE WARM SECTOR OF A
RAPIDLY DEVELOPING SYSTEM TO THE WEST. AS A RESULT...WINDS WILL
INCREASE STEADILY DURING THE DAY SATURDAY WITH ENOUGH INSTABILITY
AVAILABLE FOR A RISK OF THUNDER ACROSS THE ENTIRE AREA...POSSIBLY
ARRIVING BEFORE DAWN SATURDAY PER THE LATEST SWODY1. A BREEZY AND
MILD DAY ENSUES AHEAD OF THE SYSTEM/S COLD FRONT LATER SATURDAY WITH
DRY WEATHER EXPECTED FOR A GOOD PORTION OF THE TIME...THOUGH SOME
SCATTERED SHOWERS AND POSSIBLE THUNDERSTORMS WILL BE AROUND EASTERN
KENTUCKY INTO SATURDAY EVENING. WILL HIT THE THUNDER CHANCES AND THE
BREEZY CONDITIONS HARDER IN THE HWO TO BE ISSUED LATER THIS MORNING.
USED THE BCCONSSHORT AS A STARTING POINT FOR TEMPS...TD...AND WINDS
THROUGH 21Z FRIDAY AND THEN THE SUPERBLEND THROUGH 00Z SUNDAY. ONLY
SLIGHTLY TWEAKED POINT TEMPERATURE DATA FOR MAXES AND MINS. AS FOR
POPS...FAVORED A BLEND OF THE HRRR AND NAM12 EARLY THEN MAINLY THE
NAM12 THROUGH TONIGHT AND SATURDAY. ON THE WHOLE...ENDED UP SIMILAR
TO THE MOS BLEND WITH POPS THROUGH THE SHORT TERM...BUT DETAILS WHERE
ADDED TO SHOW SOME BREAKS WITHIN THE WARM SECTOR DRY SLOTTING
EXPECTED ON SATURDAY.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 306 PM EST FRI JAN 2 2015
THE EXTENDED PERIOD BEGINS WARM AND WET ON SUNDAY MORNING JANUARY
THE FOURTH. A LARGE SWATH OF LIGHT TO MODERATE RAIN IS PROGGED TO
MOVE ACROSS THE OHIO AND TENNESSEE VALLEY REGIONS ALONG AND JUST
AHEAD OF A VERY POTENT COLD FRONT. THE RAIN IS EXPECTED TO GRADUALLY
TAPER OFF FROM WEST TO EASTERN SUNDAY AND SUNDAY NIGHT AS THE FRONT
MOVES THROUGH. THE PRECIPITATION SHOULD BE OUT OF THE AREA BY LATE
SUNDAY NIGHT. AFTER THAT...A FRIGID ARCTIC AIR MASS IS EXPECTED TO
SETTLE OVER THE REGION FOR A FEW DAYS. AFTER A MODEST COOL DOWN
SUNDAY NIGHT...DURING WHICH TIME TEMPERATURES ARE EXPECTED TO DROP
INTO THE 20S ACROSS THE AREA...A SECOND REINFORCING SHOT OF COLD AIR
IS EXPECTED TO INVADE THE AREA TUESDAY NIGHT...AS A FAST MOVING
CLIPPER SYSTEM PASSES BY JUST TO OUR NORTH. BASED ON THE LATEST MOS
GUIDANCE AND MODEL SOUNDINGS...THE MERCURY COULD DROP INTO THE TEENS
AND LOW 20S TUESDAY NIGHT...AND PERHAPS EVEN INTO THE SINGLE DIGITS
WEDNESDAY NIGHT. THE CULPRIT OF THESE FRIGID TEMPERATURES WOULD COME
IN THE FORM OF A LARGE RIDGE OF ARCTIC HIGH PRESSURE THAT IS
EXPECTED TO SETTLE OVER THE EASTERN CONUS MID WEEK. AFTER SUNDAY AND
SUNDAY NIGHT...THE ONLY PRECIPITATION THAT MAY AFFECT THE AREA WOULD
COME TUESDAY AFTERNOON AND EVENING AS THE CLIPPER SYSTEM MOVES PAST.
ANY RAIN OR SNOW THAT FALLS THAT DAY WOULD LIKELY OCCUR NORTH OF THE
MOUNTAIN PARKWAY WITH LITTLE ACCUMULATION EXPECTED. THE REST OF THE
WEEK IS FORECAST TO BE DRY AND QUITE COLD. HIGHS ON WEDNESDAY AND
THURSDAY MAY NOT CLIMB OUT OF THE 20S. MONDAY LOOKS TO BE PRETTY
COLD AS WELL...WITH HIGHS IN THE 30S ANTICIPATED ON THAT DAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 140 PM EST FRI JAN 2 2015
SOME LIGHT RAIN SHOWERS ARE CURRENTLY MAKING THEIR WAY ACROSS THE
WESTERN AND NORTHERN PART OF THE FORECAST AREA. CIGS ARE STILL
HOLDING STEADY AT MVFR ACROSS MUCH OF THE REGION. LOWER CIGS IN THE
IFR OR LIFR RANGE ARE EXPECTED TONIGHT ALONG WITH RAIN AND BR LEADING
TO VIS RESTRICTIONS. LIGHT SOUTHWEST WINDS CAN BE EXPECTED THROUGH
THE DAY WITH AN INCREASE IN SPEEDS JUST OFF THE SFC TONIGHT FROM THE
SOUTHWEST. HAVE ADDED LLWS FOR THIS AT UP TO 35 KTS AT 1500 FEET TO
ALL THE TAFS STARTING AT EARLY AS 6Z. WENT AHEAD AND ADDED IN VCTS
FROM 6Z AND THROUGH TOMORROW AS THUNDERSTORMS ARE LIKELY TO MOVE INTO
THE AREA AT SOME POINT TONIGHT/TOMORROW...THOUGH EXACT TIMING AND
LOCATION OF WHERE THEY WILL SET UP IS STILL UNKNOWN.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JMW
SHORT TERM...GREIF
LONG TERM...AR
AVIATION...JMW
AREA FORECAST DISCUSSION
NWS JACKSON KY
148 PM EST FRI JAN 2 2015
.UPDATE...
ISSUED AT 1248 PM EST FRI JAN 2 2015
OVER THE LAST FEW HOURS...WHAT REPORTS OF PRECIP WE HAVE HAD IN OR
NEAR THE AREA HAS BEEN IN THE FORM OF RAIN...EVEN FOR LOCATIONS
SEVERAL COUNTIES TO OUR NORTH. WITH SURFACE TEMPS 35 DEGREES OR ABOVE
IN OUR NORTHERN COUNTIES...WENT AHEAD AND TOOK OUT MENTION OF ANY
FREEZING PRECIP FOR THE REMAINDER OF THE AFTERNOON. IT SEEMS AS
THOUGH MOST OF THE NEIGHBORING OFFICES ARE LETTING THEIR FROZEN
PRECIP FALL OUT OF THE FORECAST AS WELL. WAS A BIT CONCERNED ABOUT
THE ONGOING RADAR RETURNS THAT ARE MOVING EASTWARD AND INTO OUR CWA.
EVEN THOUGH MOST OF THESE APPEAR LIGHT...AND MAY NOT MAKE IT TO THE
SURFACE...THOUGHT IT BEST TO BE COVERED AND WENT AHEAD AND
INTRODUCED SLIGHT CHANCES FOR RAIN FOR MUCH OF THE CWA OVER THE NEXT
COUPLE OF HOURS. THIS IS STILL A PRECURSOR TO THE HEAVIER RAIN WHICH
SITS TO OUR WEST AND OUR SOUTH...AND IS STILL SET TO MOVE INTO THE
REGION LATER THIS EVENING/OVERNIGHT.
UPDATE ISSUED AT 1011 AM EST FRI JAN 2 2015
WENT AHEAD AND KEPT THE MENTION OF SLEET AND SNOW MIXING IN WITH RAIN
ACROSS THE NORTHERN PORTION OF THE CWA FOR THE NEXT COUPLE OF HOURS.
TEMPERATURES ARE STILL HOVERING IN THE 33 TO 35 DEGREE RANGE
HERE...BUT MOST OF THE AIR/MOISTURE ALOFT SHOULD STILL BE BELOW FREEZING.
ALSO BUMPED UP POPS IN THIS LOCATION FOR THE NEXT SEVERAL HOURS AS
WELL...AS ISOLATED TO SCATTERED LIGHT SHOWERS CONTINUE TO MOVE FROM
WEST TO EAST ACROSS NORTHERN KY. OTHER REFLECTIVITIES ARE CONTINUING
TO SHOW UP ACROSS THE WESTERN PORTION OF THE CWA MOVING EASTWARD AS
WELL. SO FAR...THE LATEST OBS ARE NOT SHOWING ANY OF THIS MOISTURE
ACTUALLY HITTING THE GROWN...BUT THOUGHT IT BEST TO GO AHEAD AND
INCLUDE THE MENTION OF SLIGHT CHANCES FOR PRECIP OVER THE NEXT FEW
HOURS ACROSS THE WESTERN CWA IN CASE SOMETHING IS ABLE TO WETBULB TO
THE SURFACE. ANY ICE POTENTIAL SHOULD BE OUT OF THE NORTHERN CWA BY
18Z THIS AFTERNOON AS TEMPERATURES CONTINUE TO SLOWLY RISE. THE NEXT
WAVE OF RAIN IS STILL EXPECTED TO ENTER INTO THE SOUTHERN CWA BY THIS
AFTERNOON.
UPDATE ISSUED AT 750 AM EST FRI JAN 2 2015
THE MORNING IS UNFOLDING MOSTLY AS EXPECTED...BUT THE LIGHT PCPN
NORTH OF THE MOUNTAIN PARKWAY IS MAKING ITS WAY TO THE SFC MORE
EFFECTIVELY THAN INITIALLY EXPECTED WHILE TO THE SOUTH THE INBOUND
PCPN HAS BEEN SLOWER TO ARRIVE. HAVE UPDATED THE NEXT SEVERAL HOURS
FOR THESE ADJUSTMENTS TAKING INTO ACCOUNT THE LATEST HRRR SCENARIO.
ALSO FINE TUNED THE T AND TD GRIDS PER THE LATEST OBS AND TRENDS.
THESE HAVE BEEN SENT TO THE NDFD AND WEB SERVERS.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 340 AM EST FRI JAN 2 2015
08Z SFC ANALYSIS SHOWS HIGH PRESSURE FADING OVER EASTERN KENTUCKY IN
ADVANCE OF A DEVELOPING WX SYSTEM TO THE SOUTHWEST AND AN AREA OF LOW
PRESSURE OFF TO THE NORTHEAST. THE CLOUDS ASSOCIATED WITH THE
SOUTHWEST SYSTEM HAVE OVERSPREAD THE AREA WITH POCKETS OF LIGHT PCPN
SHOWING UP ON THE REGIONAL RADAR...MAINLY SOUTH OF THE STATE
BORDER...THOUGH SOME RETURNS HAVE DEVELOPED ALONG INTERSTATE 64 IN
CENTRAL KENTUCKY...IN LINE WITH THE LATEST HRRR. THROUGH EAST
KENTUCKY TEMPERATURES ARE FAIRLY UNIFORM IN THE MID 30S WHILE
DEWPOINTS ARE GENERALLY IN THE MID 20S. DEW POINT DEPRESSIONS ON THE
ORDER OF 10 DEGREES WILL LEAD TO A CONCERN FOR WETBULBING WITH ANY
EARLY PCPN THIS MORNING THAT SHOULD RESULT IN PATCHES OF SLEET ALONG
WITH THE LIGHT RAIN. WILL CONTINUE TO DEPICT THIS IN THE GRIDS AND
MENTION IT IN THE HWO AND ZONES...THOUGH ANY IMPACTS ARE EXPECTED TO
BE MINIMAL GIVEN PAVEMENT TEMPERATURES ABOVE FREEZING THROUGH THE
EASTERN PARTS OF THE STATE. WINDS REMAIN LIGHT FROM THE SOUTHWEST
THROUGH THE AREA EARLY THIS MORNING.
THE MODELS ARE IN GOOD AGREEMENT ALOFT FOR THE SHORT TERM PORTION OF
THE FORECAST AS THEY ALL SHOW THE SOUTHWESTERN CLOSED LOW GETTING
PARTIALLY PICKED UP BY THE NORTHERN STREAM LATER TODAY. THIS PROCESS
RELEASES A BATCH OF ENERGY AND LOWER HEIGHTS INTO THE CENTRAL PLAINS
BY EVENING WHILE A LARGER PORTION STAYS SEPARATE OVER SOUTHERN NEW
MEXICO. THE EXPELLED NORTHERN WAVE IS QUICKLY ABSORBED INTO THE
LARGER FLOW AND SPREAD OVER THE CENTRAL GREAT LAKES BY MIDDAY
SATURDAY WHILE THE MAIN LOW IS KICKED EAST BY SOME ENERGY RIDING INTO
ITS BACKSIDE LATER SATURDAY. AHEAD OF THESE WAVES...BROAD SOUTHWEST
FLOW WILL SEND WARMER AND MORE MOIST AIR INTO THE TENNESSEE AND OHIO
VALLEYS TODAY THROUGH SATURDAY. GIVEN THE MODEL AGREEMENT HAVE
FOLLOWED THE HIGHER RESOLUTION NAM12 AND HRRR MOST CLOSELY.
SENSIBLE WEATHER WILL FEATURE THE NET RESULT OF A MOISTENING
ENVIRONMENT AND A DEVELOPING SFC LOW TO THE SOUTHWEST...RAIN CHANCES
MOVING IN FROM SOUTHWEST TO NORTHEAST TODAY. THE BETTER CHANCES
ARRIVE AFTER 18Z FOR THE BULK OF THE JKL CWA ALLOWING THE WARMER AIR
TO BRING UP TEMPERATURES WHILE DEWPOINTS CLIMB ABOVE FREEZING MAKING
ALL THE PCPN LIQUID AFTER THE EARLY MORNING POCKETS OF LIGHT MIXED
PCPN. THE REAL SURGE OF SHOWERS WILL ARRIVE LATER TONIGHT AS A
DEVELOPING WARM FRONT LIFTS INTO THE AREA AND PROVIDES A GOOD
FOCUSING MECHANISM FOR THE INCREASINGLY MOIST AIR. BY DAWN SATURDAY
THE DEEPENING SFC LOW OVER THE LOWER MISSISSIPPI VALLEY WILL LIFT ITS
WARM FRONT NORTH OF THE AREA PLACING OUR AREA IN THE WARM SECTOR OF A
RAPIDLY DEVELOPING SYSTEM TO THE WEST. AS A RESULT...WINDS WILL
INCREASE STEADILY DURING THE DAY SATURDAY WITH ENOUGH INSTABILITY
AVAILABLE FOR A RISK OF THUNDER ACROSS THE ENTIRE AREA...POSSIBLY
ARRIVING BEFORE DAWN SATURDAY PER THE LATEST SWODY1. A BREEZY AND
MILD DAY ENSUES AHEAD OF THE SYSTEM/S COLD FRONT LATER SATURDAY WITH
DRY WEATHER EXPECTED FOR A GOOD PORTION OF THE TIME...THOUGH SOME
SCATTERED SHOWERS AND POSSIBLE THUNDERSTORMS WILL BE AROUND EASTERN
KENTUCKY INTO SATURDAY EVENING. WILL HIT THE THUNDER CHANCES AND THE
BREEZY CONDITIONS HARDER IN THE HWO TO BE ISSUED LATER THIS MORNING.
USED THE BCCONSSHORT AS A STARTING POINT FOR TEMPS...TD...AND WINDS
THROUGH 21Z FRIDAY AND THEN THE SUPERBLEND THROUGH 00Z SUNDAY. ONLY
SLIGHTLY TWEAKED POINT TEMPERATURE DATA FOR MAXES AND MINS. AS FOR
POPS...FAVORED A BLEND OF THE HRRR AND NAM12 EARLY THEN MAINLY THE
NAM12 THROUGH TONIGHT AND SATURDAY. ON THE WHOLE...ENDED UP SIMILAR
TO THE MOS BLEND WITH POPS THROUGH THE SHORT TERM...BUT DETAILS WHERE
ADDED TO SHOW SOME BREAKS WITHIN THE WARM SECTOR DRY SLOTTING
EXPECTED ON SATURDAY.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 357 AM EST FRI JAN 2 2015
THE EXTENDED FORECAST PERIOD BEGINS ON SATURDAY NIGHT WITH AN
AMPLIFIED UPPER LEVEL PATTERN OVER THE CONUS. A LARGE LONGWAVE
TROUGH MOVES THROUGH THE CENTRAL PAINS AND INTO THE MS RIVER VALLEY.
AT THIS TIME A POTENT SHORT WAVE IS LIFTING OUT OF THE MID MS RIVER
VALLEY AND MOVING INTO THE OH VALLEY...WHILE A SECOND STRONG
SHORTWAVE DEVELOPS ALONG THE LOWER PORTION OF THE MS VALLEY AND
QUICK LIFTS NORTHEAST AS WELL INTO THE LOWER APPALACHIAN RANGE. A
STRONG JET DEVELOPING IN THE UPPER LEVELS ON SUNDAY NIGHT OVER THE
MID ATLANTIC WILL LIFT THE UPPER LEVEL TROUGH NORTHEAST INTO THE NEW
ENGLAND AREA. THIS SETS THE PATTERN FROM MONDAY THROUGH THURSDAY OF
A SEMI PERMANENT UPPER LEVEL LONGWAVE TROUGH OVER THE GREAT LAKES
AND NEW ENGLAND AREA. THIS CYCLONIC FLOW OVER THE NORTHEASTERN CONUS
WILL LEAD TO NORTHWEST FLOW FOR EASTERN KENTUCKY THROUGH THE REST OF
THE EXTENDED.
CLOSER TO THE SURFACE FOR THE FRONT MOVING THROUGH SAT NIGHT THROUGH
SUNDAY NIGHT...THE INHERITED FORECAST AND RESULT OF THE BLEND OF
MODELS LEAVES QUITE A BIT OF PRECIP MOVING THROUGH SAT NIGHT THROUGH
SUNDAY. PWATS DURING THIS TIME WITH MODEL SOUNDINGS SHOW 1.34 INCHES
WHICH IS AMPLE THIS TIME OF YEAR. HPC RESULTS ALONG WITH THE MODEL
BLEND PUT AROUND AN INCH IN THE AREA FOR THE STA NIGHT AND SUNDAY
TIME FRAME AND HAVE GONE WITH THESE VALUES AS THOUGH...WEAKENING THE
SHOWERS WITH THE FRONT MOVING THROUGH COULD PRODUCE SOME DECENT
RAINFALL AT TIMES. AS MENTIONED WITH THE LOW SHOWING A WEAKENING
TREND...THERE IS A DECENT AMOUNT OF ISENTROPIC LIFT AHEAD AND WITH
THIS FRONT AND WITH THE INHERITED FORECAST COUPLED WITH A CONSENSUS
OF NEIGHBORING OFFICES...DECIDED TO KEEP A SLIGHT CHANCE OF THUNDER
IN THE SATURDAY NIGHT PORTION. AS MENTIONED WITH THE PROGRESSIVE
FLOW AND QUICK EXIT OF THIS FEATURE...PRECIP HANGING UP ON THE
EASTERN RIDGES SHOULD BE SHORT IN DURATION AND HAVE ALL POPS
EXITING EARLY SUNDAY NIGHT. AS SUCH...THE MOISTURE WILL EXIT THE
AREA BEFORE ANY COLD AIR FILTERS IN. ANY CHANGE OVER TO SNOW ACROSS
THE AREA IS NOT EXPECTED.
THE DRIER NORTHWEST FLOW SETTING UP BY TUESDAY WILL HINDER PRECIP
MAKING IT FAR ENOUGH SOUTH INTO EASTERN KENTUCKY FOR SNOWFALL. BASED
ON INHERITED FORECAST...PATTERN RECOGNITION AND COLLABORATION WITH
THE NEIGHBORING OFFICES...HAVE GONE DRY WITH THE WEAK SHORTWAVE
MOVING THROUGH THE OH VALLEY TUESDAY NIGHT INTO WEDNESDAY. WHILE A
FEW FLURRIES ARE POSSIBLE AS WELL...THE GENERAL TREND WITH THIS IS
THAT AS MOISTURE STARVED AS THESE CLIPPER SYSTEMS ARE...THE BULK OF
THE UPPER LEVEL SUPPORT STAYS TO THE NORTH WITH THIS WAVE. AFTER
SUNDAY NIGHT...HAVE GONE DRY OVER EASTERN KENTUCKY FOR THE REST OF
THE FORECAST. THE DEW POINTS WITH THIS ARCTIC AIR MASS MOVING IN
DURING THE LAST PART OF THE EXTENDED IS QUITE IMPRESSIVE. QUITE A
COLD AND DRY AIR MASS MAKES ITS PRESENCE KNOWN DIVING SOUTH INTO THE
CENTRAL CONUS AND MEANDERING SOUTHEAST BY THE END OF THE EXTENDED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 140 PM EST FRI JAN 2 2015
SOME LIGHT RAIN SHOWERS ARE CURRENTLY MAKING THEIR WAY ACROSS THE
WESTERN AND NORTHERN PART OF THE FORECAST AREA. CIGS ARE STILL
HOLDING STEADY AT MVFR ACROSS MUCH OF THE REGION. LOWER CIGS IN THE
IFR OR LIFR RANGE ARE EXPECTED TONIGHT ALONG WITH RAIN AND BR LEADING
TO VIS RESTRICTIONS. LIGHT SOUTHWEST WINDS CAN BE EXPECTED THROUGH
THE DAY WITH AN INCREASE IN SPEEDS JUST OFF THE SFC TONIGHT FROM THE
SOUTHWEST. HAVE ADDED LLWS FOR THIS AT UP TO 35 KTS AT 1500 FEET TO
ALL THE TAFS STARTING AT EARLY AS 6Z. WENT AHEAD AND ADDED IN VCTS
FROM 6Z AND THROUGH TOMORROW AS THUNDERSTORMS ARE LIKELY TO MOVE INTO
THE AREA AT SOME POINT TONIGHT/TOMORROW...THOUGH EXACT TIMING AND
LOCATION OF WHERE THEY WILL SET UP IS STILL UNKNOWN.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JMW
SHORT TERM...GREIF
LONG TERM...SHALLENBERGER
AVIATION...JMW
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1205 PM EST FRI JAN 2 2015
.SYNOPSIS...
AN ARCTIC FRONT WILL SWEEP ACROSS THE REGION THIS AFTERNOON. HIGH
PRESSURE WILL BUILD INTO THE AREA TONIGHT THROUGH SATURDAY. LOW
PRESSURE TRACKING NORTHWEST OF MAINE WILL ALLOW A WARM FRONT TO
APPROACH THE REGION SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
1205 PM UPDATE...SNOW SQUALLS CONTINUE ACROSS EASTERN PORTIONS OF
OUR FORECAST AREA. THESE CONTINUE TO PRODUCE HEAVY SNOW AND GUSTY
WINDS. MOST PLACES WILL SEE AN INCH OF SNOW AT BEST, BUT ANYWHERE
SQUALLS STRIKE COULD SEE MORE; WE HAVE ALREADY HAD A REPORT OF 3
INCHES NEAR EASTON. SNOW SHOWERS AND SQUALLS WILL CONTINUE THROUGH
EARLY AFTERNOON; THEY SHOULD WIND DOWN AS THE COLD FRONT PASSES
THROUGH. THE EXCEPTION WILL BE OVER THE FAR NORTH WHERE STREAMERS
OFF THE SAINT LAWRENCE RIVER WILL BE POSSIBLE. HAVE MADE
ADJUSTMENTS TO POPS, SKY, AND TEMPERATURES TO MATCH CURRENT
TRENDS. ALSO BUMPED UP SNOWFALL ACCUMULATIONS FOR TODAY. NO OTHER
CHANGES WERE NEEDED.
PREVIOUS DISCUSSION...THE NAM AND LATEST HRRR 3KM WERE DOING
QUITE WELL W/THE CURRENT SETUP. THINKING HERE IS THAT THE FIRST
BATCH OF SNOW SHOWERS OCCURRING ATTM WILL MOVE ACROSS THE REGION
W/THE BEST ENHANCEMENT FROM MT. KATAHDIN TO THE SHERMAN-PATTEN
REGION AS UP TO AN INCH OR SNOW COULD ACCUMULATE. ANOTHER BATCH OF
SNOW SHOWERS AND A FEW SQUALLS LOOK LIKE THEY WILL SET UP BETWEEN
7 AM AND 10 AM THIS MORNING W/THE ARCTIC FRONT APPROACHING. THE
NAM SOUNDING SUPPORTS 850-700MBS LAPSE RATES AROUND 7.0 C/KM W/A
FCST CAPE IN THE RANGE OF 75-100 JOULES. THIS IS WHERE IS SOME
AREAS COULD PICK UP ANOTHER INCH OF SNOW W/SOME GUSTY WINDS.
FURTHER SOUTH FROM THE CENTRAL HIGHLANDS DOWN TO INTO TEH DOWNEAST
REGION, MAINLY MOSTLY CLOUDY W/A FEW FLURRIES. THINGS WIND DOWN
NEAR OR AFTER 18Z. TEMPERATURES LOOK LIKE THEY COULD ACTUALLY
CLIMB SOME THIS MORNING AHEAD OF THE FRONT AND THEN FALL BACK
SHARPLY THIS AFTERNOON INTO THE EVENING. ADJUSTMENTS WERE NEEDED
TO THE MAXES TODAY TO BRING THEM UP AND SHOW AN EARLY DAYTIME HIGH
TEMP. CLOUDS SHOULD BREAK UP THIS AFTERNOON AS THE LATEST IR
SATELLITE IMAGERY SHOWS THAT CLEARING BACK ACROSS QUEBEC AND THIS
IS SUPPORTED BY THE NAM GUIDANCE. WINDS WILL ALSO PICK UP FOR A
TIME AS THE FRONT MOVES IN.
THE CHALLENGE TONIGHT WILL BE HOW SOON THE REGION CLEARS OUT AND
HOW QUICKLY THE WINDS DROP OFF W/HIGH PRES MOVING RAPIDLY INTO
THE REGION OVERNIGHT. ANOTHER FACTOR WILL BE THE WNW FLOW COMING
OFF THE OPEN ST. LAWRENCE AS THIS AIRMASS IS QUITE COLD. SOUNDINGS
SHOW THE COLUMN TO DRY OUT THROUGH 500MBS W/THE EXCEPTION OF THE
CROWN OF MAINE AS SOME MOISTURE STAYS TRAPPED BETWEEN 925-850MBS.
DECIDED TO HANG ON TO SOME CLOUDS ACROSS THE CROWN AND WENT
W/CLEARING FOR THE REST OF THE CWA. SOMETIMES W/A SCENARIO LIKE
THIS ONE, LIGHT SNOW COULD SET UP, BUT SINCE THE AIRMASS LOOKS BE
DRY ABOVE 850MBS OVER THE CROWN, DECIDED TO STAY AWAY FROM ANY
MENTION OF LIGHT SNOW ATTM. STAYED CLOSE TO THE DAYCREW`S THINKING
OF OVERNIGHT LOWS DROPPING TO 10-15 BELOW ACROSS THE NORTH AND
CENTRAL AREAS W/SINGLE NUMBERS FOR THE DOWNEAST REGION INCLUDING
THE COAST. IF THE WINDS DROP OFF SOONER, THEN TEMPERATURES COULD
BE EVEN COLDER BY 7 AM SATURDAY. THIS CAN BE ASSESSED FURTHER BY
THE ONCOMING DAYCREW.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
SATURDAY IS SHAPING UP AS THE BETTER OF THE TWO WEEKEND DAYS AS
LONG AS YOU DONT MIND THE COLD. EXPECT PLENTY OF SUN TO START AS
HIGH PRESSURE MOVES ACROSS THE REGION. HIGH CLOUDS WILL BEGIN TO
INCREASE BY AFTERNOON. HIGH TEMPERATURES ON SATURDAY WILL ONLY
RANGE FROM THE SINGLE DIGITS TO AROUND 10 ABOVE NORTH AND CENTRAL
AREAS WITH MID TO UPPER TEENS DOWN EAST.
CLOUDS WILL CONTINUE TO INCREASE AND THICKEN SATURDAY EVENING IN
ADVANCE OF LOW PRESSURE APPROACHING FROM THE WEST. EXPECT
PRECIPITATION IN THE FORM OF SNOW TO DEVELOP FROM SOUTHWEST TO
NORTHEAST BY OR SHORTLY AFTER MIDNIGHT. WARMER AIR MOVING IN ALOFT
WILL RESULT IN THE PRECIPITATION MIXING WITH SLEET AND FREEZING
RAIN ACROSS DOWN EAST AREAS BY LATE SATURDAY NIGHT BUT THE
PRECIPITATION WILL REMAIN IN THE FORM OF ALL SNOW ACROSS NORTHERN
AND CENTRAL AREAS THROUGH THE NIGHT SATURDAY WITH SEVERAL INCHES
OF SNOW POSSIBLE BY DAYBREAK SUNDAY. LOW TEMPERATURES WILL OCCUR
EARLY IN THE EVENING SATURDAY BEFORE SLOWLY RISING OVERNIGHT.
PRECIPITATION WILL BE ONGOING FIRST THING SUNDAY AS LOW PRESSURE
CONTINUES TO TRACK TO OUR NORTHWEST. MODELS CONTINUE TO HINT AT A
WEAK TRIPLE POINT LOW FORMING ALONG THE MAINE COAST DURING SUNDAY.
AS THE PRIMARY LOW CONTINUES TO TRACK TO OUR NORTHWEST ON SUNDAY
WARMER AIR ALOFT WILL CONTINUE TO BRING MILDER AIR ALOFT WITH
PRECIPITATION CHANGE TO SLEET AND FREEZING RAIN ACROSS NORTHERN
AND CENTRAL AREAS AND EVEN ALL RAIN ACROSS DOWN EAST ESPECIALLY
THE COAST. RIGHT NOW IT APPEARS AS IF MOST AREAS WILL SEE SNOW
TOTAL RANGING FROM 3 TO 6 INCHES BEFORE THE CHANGEOVER OCCURS ON
SUNDAY. ICE ACCUMULATIONS ARE EXPECTED TO RANGE FROM ABOUT A
TENTH OF AN INCH CENTRAL AND DOWN EAST AND LESS THAN A TENTH OF AN
INCH ACROSS NORTHERN AREAS. SINCE THIS IS STILL A LATE FOURTH INTO
FIFTH PERIOD EVENT WONT BE ISSUING ANY HEADLINES YET BUT A THIS
TIME IT LOOKS LIKE WINTER WEATHER ADVISORIES WILL PROBABLY BE
NEEDED FOR JUST ABOUT ALL AREAS OF OUR CWA FOR SATURDAY NIGHT AND
SUNDAY FOR THE COMBINATION OF SNOW AND MIXED PRECIPITATION. THE
STEADY PRECIPITATION IS EXPECTED TO WIND DOWN ACROSS THE AREA AS
THE LOW CONTINUES TO TRACK TO THE NORTHEAST.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
LOW PRESSURE WILL CONTINUE TO TRACK AWAY FROM THE REGION SUNDAY
NIGHT. ANY LINGERING SNOW SHOWERS OR MIXED PRECIPITATION WILL BE
DIMINISHING EARLY SUNDAY EVENING.
MUCH COLDER AIR WILL BEGIN TO POUR INTO THE REGION ON MONDAY WITH
HIGH TEMPERATURES OCCURRING EARLY IN THE DAY AND THEN FALLING IN
THE AFTERNOON. MONDAY NIGHT IS SHAPING UP AS A MAINLY CLEAR AND
BITTER COLD NIGHT WITH LOW FALLING TO 10 BELOW TO 15 BELOW ZERO
ACROSS THE NORTH AND ZERO TO 5 BELOW ZERO ACROSS CENTRAL AND DOWN
EAST. MAY NEED WIND CHILL ADVISORIES FOR NORTHERN AREAS AS WELL
AS WEST WINDS WILL MAKE IT FEEL EVEN COLDER.
TUESDAY WILL START OFF MAINLY CLEAR BEFORE CLOUDS BEGIN TO INCREASE
IN ADVANCE OF A CLIPPER TYPE SYSTEM APPROACHING FROM THE WEST.
EXPECT THE CHANCE FOR SNOW ESPECIALLY ACROSS DOWN EAST AREAS AS
THE SYSTEM MOVES EAST. THE SNOW MAY CONTINUE INTO THE FIRST PART
OF WEDNESDAY BEFORE DIMINISHING WEDNESDAY AFTERNOON.
EXPECT MAINLY DRY WEATHER WEDNESDAY NIGHT AND THURSDAY BUT
CONTINUED BELOW NORMAL TEMPERATURES.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
NEAR TERM: VFR CONDITIONS FOR THE MOST PART ACROSS THE REGION
W/TEMPO MVFR FOR THE NORTHERN TERMINALS TODAY W/SOME SNOW. WINDS
WILL PICK UP LATER THIS MORNING INTO THE AFTERNOON W/GUST
POTENTIAL ACROSS NORTHERN AREAS OF 25KTS.
SHORT TERM: VFR CONDITIONS EXPECTED ON SATURDAY. WIDESPREAD FLIGHT
RESTRICTIONS ARE EXPECTED TO DEVELOP SATURDAY NIGHT AND CONTINUE
ON SUNDAY WITH SNOW/SLEET/FREEZING RAIN EXPECTED TO AFFECT ALL
TERMINALS. R/WY SNOW ACCUMULATIONS FROM LATE SATURDAY NIGHT
THROUGH SUNDAY MAY RANGE FROM 3 TO 6 INCHES AT ALL THE TERMINALS
ALONG WITH THE POSSIBILITY OF SOME ICE ACCUMULATION ESPECIALLY
KBGR/KHUL TERMINALS. PRECIPITATION WILL BEGIN TO DIMINISH SUNDAY
EVENING WITH CONDITIONS IMPROVING TO VFR BY LATER SUNDAY NIGHT.
VFR CONDITIONS EXPECTED MONDAY. VFR MOST OF TUESDAY BUT POTENTIAL
FOR SNOW DEVELOPING LATE IN THE DAY ESPECIALLY KBGR/KBHB WITH
POSSIBLE IFR CONDITIONS BY TUE EVE.
&&
.MARINE...
NEAR TERM: A SMALL CRAFT ADVISORY REMAINS IN EFFECT THROUGH
TONIGHT W/GUSTS HITTING CLOSE TO 30 KTS. SEAS ARE RUNNING 7-10 FT
OVER THE OUTER ZONES AND THEY COULD BUILD A FEW MORE FT BEFORE
LEVELING OFF. SW WINDS WILL VEER TO THE WNW THIS AFTERNOON INTO
TONIGHT. ADJUSTMENTS WERE MADE TO THE SEAS TO ACCOUNT FOR THE
CURRENT CONDITIONS.
SHORT TERM: SMALL CRAFT ADVISORY CONDITIONS ARE POSSIBLE
SATURDAY. WINDS/SEAS WILL BRIEFLY DIMINISH EARLY SATURDAY EVENING
BEFORE INCREASING LATE SATURDAY NIGHT AND SUNDAY. A GALE WATCH
MAY BE REQUIRED FOR LATER SATURDAY NIGHT AND SUNDAY WITH CONTINUED
POTENTIAL FOR GALE FORCE WIND EARLY NEXT WEEK IN THE COLD
ADVECTION. VISIBILITY WILL BE UNRESRICTED SATURDAY AND THEN A
MILE OR LESS IN PRECIPITATION LATER SATURDAY NIGHT AND SUNDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST SATURDAY FOR ANZ050>052.
&&
$$
NEAR TERM...HASTINGS/HEWITT
SHORT TERM...DUDA
LONG TERM...DUDA
AVIATION...HASTINGS/HEWITT/DUDA
MARINE...HASTINGS/HEWITT/DUDA
AREA FORECAST DISCUSSION
NWS JACKSON MS
1018 AM CST FRI JAN 2 2015
...WET PATTERN TO CONTINUE THROUGH FIRST HALF OF WEEKEND...WITH
INCREASING RISK FOR ACTIVE THUNDERSTORMS ON SATURDAY...
.UPDATE...MAIN ADJUSTMENTS ARE TO LOWER POPS AND INCLUDE DRIZZLE
TODAY. ALSO ADJUSTED TEMPS BASED ON LATEST HRRR.
&&
.SHORT TERM...
RAIN IS GRADUALLY TAPIERING OFF FROM THE WEST ACROSS NORTHERN HALF OF
AREA AFTER A WIDESPREAD MODERATE TO HEAVY RAIN EVENT LAST 24
HOURS...WITH MOST LOCATIONS IN NORTHERN HALF OF AREA PICKING UP 1 TO
3 INCHES OF RAIN. STEADIEST RAIN IS CURRENTLY WORKING EAST ACROSS HWY
82 CORRIDOR EAST OF I-55. REST OF AREA IS SEEING LOTS OF LOW
CLOUDS/DRIZZLE WITH SOME PATCHY -RA AND SHRA. LATEST HRRR RUNS IMPLY
THAT ONCE MAIN BATCH OF RAIN PUSHES EAST THIS DZ/SHRA REGIME WILL
DOMINATE REST OF TODAY...AND HAVE ADJUSTED POPS AND WX ACCORDINGLY.
COULD BE SOME UPTICK IN CONVECTIVE COVERAGE AND MAYBE A FEW TSRA LATE
TODAY AS LOW LEVEL FLOW BACKS AROUND A BIT AGAIN AND ISENTROPIC
ASCENT INCREASES.
TEMPERATURES WILL NOT MOVE MUCH OVER MOST OF THE AREA TODAY AS
STAGNANT COOL HIGH PRESSURE REMAINS OVERHEAD...GRADUALLY WEAKENING.
EXCEPTION SHOULD BE DOWN IN THE HWY 98 CORRIDOR. LATEST VISIBLE
IMAGERY SHOWS THAT SOME PEEKS OF SUN SHOULD OCCUR DOWN THERE...AND
WARM FRONTAL BOUNDARY WILL BE SHIFTING SLOWLY NW USHERING IN WARMER
AIR. HRRR ACTUALLY PUSHES TEMPS INTO THE 70S IN THE HATTIESBURG/
PURVIS AREAS THIS AFTERNOON. WHILE I DID NOT TAKE THE GRIDS THAT
WARM...DID USE THE HRRR AS A STARTING POINT TO ADJUST TEMPS UP
SEVERAL DEGS IN THE SE AND TRY TO BEST DEPICT STRONG THERMAL GRADIENT
ACROSS AREA.
WITH REGARD TO SATURDAY SYSTEM...MODELS CONTINUE IN GENERAL AGREEMENT
THAT WE WILL BE ON THE SOUTHERN PERIPHERY OF EJECTING SW CONUS UPPER
SYSTEM. STILL APPEARS AS THOUGH INSTABILITY AND SHEAR WILL INCREASE
DRAMATICALLY STARTING LATE TONIGHT INTO SAT MORNING TO SUPPORT A RISK
OF SEVERE STORMS...ALONG WITH HEAVY RAINFALL. WILL BE COORDINATING
WITH SPC AND ADJUSTING HAZARD GRAPHICS/HWO THIS AFTERNOON...AS WELL
AS EVALUATING HYDRO SITUATION FOR ANY POTENTIAL FLOOD WATCHES. MORE
DETAILS IN THE AFTERNOON DISCUSSION.
&&
.AVIATION...
PER LASTEST OBS/SATELLITE TRENDS AND SREF/HRRR GUIDANCE...INCREASING
WARM AND MOIST AIR WILL BRING WIDESPREAD LOW STRATUS AND AREAS OF
FOG/DRIZZLE WITH IFR AND OCCASIONALLY LIFR RESTRICTIONS THROUGH
TONIGHT. THERE HAS BEEN SOME CIG BREAK-UP NEAR HBG...BUT EXPECT
LOWER CIGS TO RETURN BY LATE AFTN. AREAS OF SHRA/TSRA CAN BE
EXPECTED...BUT THE BULK OF TSRA ACTIVITY SHOULD HOLD OFF UNTIL
SATURDAY. AWAY FROM TSRA...LOOK FOR PREVAILING CIGS TO LIFT SATURDAY
MORNING TO MVFR CATEGORY AS STRONGER MIXING OCCURS AHEAD OF AN
APPROACHING COLD FRONT. /EC/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 55 55 70 47 / 66 56 95 71
MERIDIAN 52 53 70 51 / 68 67 83 90
VICKSBURG 54 55 69 44 / 57 69 100 40
HATTIESBURG 68 61 72 55 / 54 54 72 90
NATCHEZ 58 61 70 46 / 54 68 99 43
GREENVILLE 49 48 64 41 / 65 74 100 27
GREENWOOD 50 49 67 44 / 100 69 100 54
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
AEG/EC
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
108 PM EST FRI JAN 2 2015
.SYNOPSIS...
SURFACE HIGH PRESSURE WILL MOVE ACROSS THE REGION TODAY. A WARM
FRONT WILL APPROACH FROM THE SOUTH TONIGHT AND PASS THROUGH THE
AREA ON SATURDAY. THIS WILL BE FOLLOWED BY A COLD FRONT SATURDAY
NIGHT WHICH WILL USHER IN MUCH COLDER AIR FOR NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SHOWERS ASSOCIATED WITH A WEAK UPPER LEVEL DISTURBANCE ARE
PUSHING EAST ACROSS FAR SOUTHERN PORTIONS OF OUR FA THIS MORNING.
WE HAVE HAD SOME REPORTS OF SLEET WITH THIS AND WILL CONTINUE
WITH A MENTION OF A MIXED BAG OF PCPN THROUGH THE REST OF THIS
MORNING WITH A GRADUAL TRANSITION TO MORE RAIN AS WE SLOWLY WARM.
LATEST RAP AND HRRR SUGGEST THAT THIS PCPN SHOULD SLIDE OFF TO OUR
EAST/SOUTHEAST BY EARLY AFTERNOON. EXPECT HIGHS TODAY RANGING FROM
THE MID 30S NORTHWEST TO UPPER 30S/NEAR 40 ACROSS THE FAR SOUTH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
MODELS ARE IN FAIRLY DECENT AGREEMENT IN TERMS OF SYNOPTIC SCALE
SYSTEMS. HAVE USED A BLEND OF THE NAM/GFS/ECMWF FOR THE SHORT TERM
FORECAST.
UPR LVL LOW OVER THE DESERT SW WILL BEGIN TO EJECT NE TO THE SRN
PLAINS BY SATURDAY MORNING. AS THE HIGH MOVES OFF TO THE EAST
TONIGHT...WARM...MOIST RETURN IN THE FORM A LOW LEVEL JET WILL
BRING AN INCREASING THREAT FOR PCPN FROM SOUTH TO NORTH THROUGH
THE OVERNIGHT HOURS. WE SHOULD SEE A LITTLE DROP OFF TO
TEMPERATURES EARLY THIS EVENING...THEN AS CLOUDS THICKEN AND WINDS
INCREASE...THEY SHOULD STEADY OUT AND SLIGHTLY RISE THROUGH THE
OVERNIGHT HOURS. THE ONSET OF PCPN AND SURFACE TEMPERATURES WILL
BE CRITICAL IN FORECASTING PCPN TYPE. IT LOOKS LIKE LOCATIONS
GENERALLY ALONG AND SOUTH OF THE OHIO RIVER WILL REMAIN IN LIQUID
FORM AS TEMPERATURES REMAIN SLIGHTLY ABOVE FREEZING. POINTS TO THE
NORTH...PCPN MAY START OUT BRIEFLY AS A LITTLE SLEET...BUT WITH
TEMPERATURES AT OR SLIGHTLY BELOW FREEZING...THE THREAT FOR A
PERIOD OF FREEZING RAIN WILL EXIST AS MUCH WARMER AIR ALOFT IS
ADVECTED NORTHWARD. WITH TEMPERATURES NEAR FREEZING...ICING
ACCRETION SHOULD BE LIMITED...BUT SOME LIGHT ICING WILL LIKELY
OCCUR ON EXPOSED OBJECTS AND ELEVATED SURFACES LIKE UNTREATED
BRIDGES AND OVERPASSES. A FREEZING RAIN ADVISORY MAY BE NEEDED FOR
NORTH OF THE OHIO RIVER LATE TONIGHT INTO EARLY SATURDAY MORNING
FOR AMOUNTS GENERALLY LESS THAN A 0.10 OF AN INCH. WILL CONTINUE
TO HIGHLIGHT THE THREAT IN THE HWO PRODUCT.
ON SATURDAY...UPR LVL LOW WILL MOVE NORTHEAST TO THE CENTRAL
PLAINS BY SATURDAY EVENING. AS IT DOES...A WARM FRONT WILL LIFT
NORTH ACRS THE REGION AS SURFACE LOW PRESSURE DEEPENS TO OUR SOUTHWEST.
ANY FREEZING RAIN ACRS THE FAR NORTH SHOULD CHANGE TO ALL RAIN BY
MID MORNING AS TEMPERATURES CONTINUE TO SLOWLY WARM. FOR THE
REMAINDER OF SATURDAY...MOISTURE CONVERGENCE AND LIMITED INSTABILITY
WILL BRING SHOWERS AND PERHAPS AN ELEVATED THUNDERSTORM TO THE
REGION FOR THE REMAINDER OF THE DAY. HIGHS WILL OCCUR BY EVENING
AS LOW LEVEL FLOW TURNS SOUTHERLY. THEY SHOULD RANGE FROM NEAR 50
NORTH TO THE UPPER 50S SOUTH OF THE OHIO RIVER.
FOR SATURDAY NIGHT...UPR LVL LOW WILL PHASE WITH ENERGY FROM THE
NORTHWEST. THIS WILL CONTINUE TO DEEPEN THE SURFACE LOW AS IT MOVE
NORTHEAST THROUGH THE GREAT LAKES. A COLD FRONT WILL THEN SWING
EASTWARD THROUGH THE AREA. WIDESPREAD SHOWERS AND PERHAPS EMBEDDED
THUNDER ARE EXPECTED ALONG AND AHEAD OF THE FRONT. MODELS CONTINUE
TO ADVERTISE STRONG LOW LEVEL WINDS ALONG AND AHEAD OF THE FRONT.
THERE IS SOME CONCERN THAT THERE COULD BE SOME ENHANCED WIND GUSTS
WITH CONVECTIVE PCPN SHOULD IT TRY TO ORGANIZE INTO A LINEAR
STRUCTURE. SHERB PARAMETERS SUPPORT THIS. AM NOT READY YET TO
PLACE THE CONCERN IN THE HWO...BUT WILL CERTAINLY ANALYZE
CONVECTION ALLOWING MODELS AS WE GET CLOSER TO SATURDAY NIGHT. WE
SHOULD AT LEAST SEE SOME SYNOPTIC WIND GUSTS AROUND 30 KNOTS WITH
FRONTAL PASSAGE SATURDAY NIGHT. OVERNIGHT LOWS WILL OCCUR BY
SUNDAY MORNING AS TEMPERATURES FALL BEHIND THE FRONT. OVERALL WE
SHOULD SEE 1 TO 1.50 INCHES OF RAIN WITH THIS SYSTEM. STREAM FLOW
ACRS OUR REGION IS LOW AS IS OUR FLASH FLOOD GUIDANCE...SO THE
FLOOD THREAT OTHER THAN SOME MINOR SHORT TERM FLOODING SHOULD
REMAIN LOW AS WELL.
FOR SUNDAY...ADDITIONAL UPR LVL ENERGY ALONG WITH STRONG CAA WILL
KEEP SKIES CLOUDY ALONG WITH A THREAT OF SCATTERED RAIN AND/OR
SNOW SHOWERS. LITTLE SNOW ACCUMULATION IS EXPECTED. HIGH TEMPERATURES
WILL OCCUR EARLY WITH TEMPERATURES DROPPING THROUGH THE DAY.
BY SUNDAY NIGHT...ARCTIC HIGH PRESSURE WILL BUILD SOUTHEAST INTO
THE THE AREA. CLOUDS SHOULD DECREASE SOME ALONG WITH A TAPERING
OFF OF SCATTERED SNOW SHOWERS.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
ARCTIC HIGH PRESSURE WILL WORK INTO THE AREA FOR MONDAY ALLOWING
FOR DRY CONDITIONS. TEMPERATURES WILL STRUGGLE TO RISE WITH THE
COLD AIRMASS IN PLACE. A CLIPPER WILL MOVE THROUGH THE AREA LATE
MONDAY NIGHT INTO THE DAY ON TUESDAY. TEMPERATURES WILL BE COLD
ENOUGH THAT PRECIPITATION WILL ALL BE IN THE FORM OF SNOW. THESE
TYPE OF SYSTEMS ARE TYPICALLY PRETTY EFFICIENT WITH HIGH SNOW TO
LIQUID RATIOS. MODELS HAVE COME INTO DECENT AGREEMENT ON THE
TIMING AND STRENGTH OF THIS FEATURE. THE BEST CHANCE FOR
ACCUMULATING SNOW WILL BE ACROSS NORTHERN PORTIONS OF THE FA. WITH
DECENT MODEL AGREEMENT AND THIS FEATURE SHOWING UP FOR MULTIPLE
RUNS HAVE DECIDED TO CONTINUE TO INCREASE PRECIPITATION CHANCES ON
TUESDAY.
MOST OF THE PRECIPITATION WILL TAPER OFF TUESDAY EVENING HOWEVER
SOME RESIDUAL SNOW SHOWERS WILL STICK AROUND TUESDAY NIGHT INTO
WEDNESDAY ACROSS NORTHERN PORTIONS OF THE FA WITH WINDS OFF OF THE
LAKE.
THE COLDEST TEMPERATURES OF THE LONG TERM PERIOD LOOK TO BE
WEDNESDAY NIGHT ACROSS THE AREA. HIGH PRESSURE WILL BE IN PLACE AND
THERE WILL BE SOME BREAKS IN THE CLOUDS. WITH SOME SNOW ON THE
GROUND STILL FROM THE TUESDAY SYSTEM ALSO POSSIBLE AND THE COLD
AIRMASS IN PLACE EXPECT TEMPERATURES TO DROP DOWN INTO THE SINGLE
DIGITS ACROSS MOST LOCATIONS. TEMPERATURES WILL START TO RISE
SLIGHTLY ON THURSDAY AS SOUTHERLY FLOW DEVELOPS.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
SURFACE HIGH PRESSURE WILL CONTINUE TO SHIFT OFF TO THE
EAST THROUGH LATE AFTERNOON/EARLY EVENING. AS IT DOES...THE LOW
LEVEL FLOW ACROSS OUR AREA WILL CONTINUE TO BACK AND INCREASE AS A
STRENGTHENING LOW LEVEL JET ROTATES UP INTO THE OHIO VALLEY
THROUGH SATURDAY MORNING. AN ASSOCIATED WARM FRONT WILL LIFT NORTH
ACROSS OUR AREA DURING THE DAY ON SATURDAY. INCREASING ISENTROPIC
LIFT LATER TONIGHT WILL ALLOW FOR SHOWERS TO WORK THEIR WAY NORTH
INTO OUR AREA AFTER MIDNIGHT. GIVEN THE WARMING AIR ALOFT...EXPECT
PCPN TO BE ALL LIQUID. HOWEVER...SURFACE TEMPERATURES WILL LIKELY
BE NEAR OR JUST BELOW FREEZING AS THE PCPN BEGINS AND THIS WILL
LEAD TO THE POSSIBILITY OF A BRIEF (HOUR OR TWO) PERIOD OF
FREEZING RAIN AT ONSET. WOULD EXPECT THE BEST CHANCE FOR THIS TO
BE ALONG AND NORTH OF THE I-70 CORRIDOR. AS THE PCPN
DEVELOPS...EXPECT CIGS AND VSBYS TO DROP THROUGH MVFR INTO IFR
CATEGORY LATE TONIGHT INTO SATURDAY MORNING. AS THE WARM FRONT
LIFTS NORTH AND WE START TO GET INTO THE WARM SECTOR...WE COULD
BEGIN TO SEE SOME IMPROVEMENT IN CIGS FROM THE SOUTH THROUGH THE
AFTERNOON. THIS WILL ALSO ALLOW FOR SOME WEAK INSTABILITIES TO
ADVECT NORTH INTO THE REGION SO A FEW THUNDERSTORMS WILL BE
POSSIBLE DURING THE AFTERNOON HOURS. DUE TO THE LOWER PROBABILITY
THOUGH...HAVE LEFT MENTION OF THUNDER OUT OF THE KCVG TAF ATTM.
OUTLOOK...MVFR CEILINGS AND VISIBILITIES POSSIBLE INTO SUNDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HICKMAN
NEAR TERM...JGL
SHORT TERM...HICKMAN
LONG TERM...NOVAK
AVIATION...JGL
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
345 PM CST FRI JAN 2 2015
.DISCUSSION...
A WARM FRONT OVER THE WATERS THIS MORNING HAS CONTINUED TO PUSH
NORTH AND HAS STARTED TO MOVE INLAND. THIS HAS ALLOWED DENSE SEA
FOG TO START TO MOVE INLAND AS WELL. DUE TO THIS HAVE EXTENDED
THE DENSE FOG ADVISORY UNTIL 6 AM TOMORROW MORNING AND HAVE ALSO
ADDED BRAZORIA... CHAMBERS...HARRIS... AND LIBERTY COUNTIES.
GFS... EURO... AND CANADIAN ARE ALL IN AGREEMENT WITH RAIN
CHANCES INCREASING STARTING AFTER MIDNIGHT TONIGHT INTO SATURDAY
MORNING. JET DYNAMICS AGAIN LOOK PRETTY GOOD WITH SOUTHEAST TEXAS
BEING IN A RRQ AND LFQ. FORECAST SOUNDINGS FOR THE GFS AND NAM
BOTH SHOW K INDEX VALUES AROUND 37 EARLY TOMORROW MORNING WITH
PWATS RANGING FROM 1.45 TO AROUND 1.60" (AROUND TO JUST UNDER +2
SD FOR THIS TIME OF YEAR). HIGH RES RAP HAS PERFORMED THE BEST
TODAY AND DOES NOT HAVE THAT IMPRESSIVE OF RAINFALL TOTALS FOR
TOMORROW MORNING WHILE THE NAM AND EURO HAVE AROUND 0.5" TO 1.50"
TOTAL FOR THE EVENT. THE STRONG UPPER LIFT IS HARD TO IGNORE AND
WILL GO WITH GFS/ EURO CONSENSUS ON RAINFALL TOTALS. THE HIGHEST
PRECIP TOTALS DUE APPEAR TO BE TOWARDS PORT AUTHOR THOUGH.
THE RAIN WILL MOVE OUT OF THE AREA SATURDAY WITH CLEARING SKIES
BEHIND IT. A STRONGER ARCTIC FRONT WILL THEN MOVE THROUGH THE AREA
SUNDAY MORNING. AHEAD OF THE FRONT SOME PATCHY FOG CAN BE EXPECTED
AS WINDS WEAKEN AND SKIES GO MOSTLY CLEAR. DEWPOINT DEPRESSION
FIELD FROM THE NAM SUPPORTS THIS. AT THE SAME TIME AN UPPER LEVEL
LOW WILL FORM OVER THE BAJA OF CALIFORNIA AND BEGIN TO RETROGRADE.
THE LOW WILL THEN MOVE UNDERNEATH A RIDGE OF HIGH PRESSURE FORMING
A REX BLOCK. THE CANADIAN AND EURO ARE AGAIN IN GOOD AGREEMENT
HERE. THE GFS CONTINUES TO TREND TOWARDS THE CANADIAN/ EURO
SOLUTION. THE EURO THEN BRINGS A MUCH STRONGER FRONT THROUGH THE
AREA EARLY WEDNESDAY. THE EURO AND CANADIAN BRING A 1050MB HIGH
DOWN WITH A 1043 HIGH SETTLING OVER SAN ANGELO THURSDAY MORNING.
THE EURO AND CANADIAN ALMOST LOOK IDENTICAL THURSDAY MORNING.
GIVEN THE CONSISTENCY BETWEEN THE EURO AND CANADIAN HAVE TRENDED TEMPS
DOWN SLIGHTLY THURSDAY MORNING. 23
&&
.MARINE...
A WARM FRONT CONTINUES TO ENCROACH ON THE COAST AND SFC DEW PTS OVER
THE WATER HAVE WARMED INTO THE LOWER 60S. WATER TEMPS ARE IN THE
UPPER 50S AND THIS HAS LED TO SOME SEA FOG. FEEL THE THREAT FOR FOG
WILL PERSIST FOR MUCH OF THE NIGHT AND WILL EXTEND THE DENSE FOG
ADVISORY OVER THE WATER THROUGH 12Z. SCATTERED SHRA/TSRA WILL BECOME
MORE NUMEROUS TONIGHT INTO SATURDAY AS A COLD FRONT APPROACHES THE
AREA. CONVECTION WILL PROVIDE SOME MIXING FROM TIME TO TIME BUT FEEL
THE OVERALL TREND WILL FAVOR LOW VSBY IN FOG. ALTHOUGH WINDS HAVE
DIMINISHED...FEEL TIDE LEVELS WILL REMAIN SLIGHTLY ELEVATED UNTIL A
PACIFIC COLD FRONT USHERS IN AN OFFSHORE FLOW ON SATURDAY MORNING. A
SECONDARY SURGE OF COLDER AIR ON SUNDAY WILL MOVE OVER THE WARMER
GULF WATERS AND THE STRONG CONTRAST IN TEMPS WILL PROVIDE FOR A
STRONG THERMAL GRADIENT AND OFFSHORE WIND SPEEDS WILL INCREASE. AN
SCA WILL LIKELY BE REQUIRED SUNDAY AND SUNDAY NIGHT. ANOTHER FRONT
WILL CROSS THE COASTAL WATERS ON WEDNESDAY WITH ANOTHER SCA LIKELY
AT THAT TIME. 43
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 44 58 38 48 29 / 100 50 0 0 0
HOUSTON (IAH) 51 60 42 53 33 / 100 60 0 0 0
GALVESTON (GLS) 57 60 47 53 40 / 90 80 10 0 0
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...DENSE FOG ADVISORY UNTIL 6 AM CST SATURDAY FOR THE FOLLOWING
ZONES: BRAZORIA...CHAMBERS...GALVESTON...HARRIS...LIBERTY.
GM...DENSE FOG ADVISORY UNTIL 6 AM CST SATURDAY FOR THE FOLLOWING
ZONES: GALVESTON BAY...WATERS FROM HIGH ISLAND TO FREEPORT
OUT 20 NM.
&&
$$
DISCUSSION...23
AVIATION/MARINE...43
YOU CAN SEE AN ILLUSTRATED VERSION OF THE FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1105 AM CST FRI JAN 2 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 301 AM CST FRI JAN 2 2015
CURRENTLY AS OF 09Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED A SHORTWAVE TROUGH OVER THE YUKON OF CANADA...A POTENT UPPER
TROUGH OVER NORTHERN BRITISH COLUMBIA...UPPER LOWS OVER ARIZONA AND
THE DENVER AREA...AND BROAD UPPER TROUGHING OVER EASTERN CANADA INTO
THE GREAT LAKES. WITH THE FORECAST AREA UNDER THE NORTHWEST FLOW ON
THE EDGE OF THIS UPPER TROUGHING...SUBSIDENCE AND DRYING HAS BEEN
OCCURRING. THIS HAS TRANSLATED INTO CLEARING SKIES IN THE WAKE OF A
SURFACE COLD FRONTAL PASSAGE DURING THE NIGHT. A BIT OF ARCTIC AIR
HAS BEEN SPILLING INTO NORTHERN WISCONSIN...NORTH OF HIGHWAY 29...
REFLECTED BY 925MB TEMPS DROPPING TO -12 TO -16C THERE AND SURFACE
TEMPERATURES IN THE SINGLE DIGITS ABOVE AND BELOW ZERO. READINGS ARE
MOSTLY IN THE TEENS ELSEWHERE IN THE FORECAST AREA. ONLY OTHER ITEM
OF NOTE WAS A LOOK AT PRECIPITABLE WATER VALUES FROM 00Z RAOBS. MOST
READINGS ACROSS THE CENTRAL/NORTHERN PLAINS AND OUR REGION WERE
BETWEEN 0.2 AND 0.35...FAIRLY DRY. HOWEVER...0.7-1 INCH VALUES WERE
PRESENT ACROSS THE SOUTHERN PLAINS AHEAD OF THE ARIZONA UPPER LOW.
MUCH OF THE SHORT TERM PERIOD IS QUIET THANKS TO THE DRY AIRMASS IN
PLACE REFLECTED BY 00Z RAOBS. HOWEVER...AS WE GET INTO THE AFTER
MIDNIGHT HOURS TONIGHT...THE 02.00Z GFS AND NAM SPREAD SOME LIGHT
QPF FROM THE SOUTH INTO CLAYTON/GRANT COUNTY AREA. THE 02.06Z
NAM/02.00Z ECMWF TAKE IT ONE STEP FURTHER AND SPREAD IT ALL THE WAY
THROUGH ABOUT THE EAST HALF OR MORE OF THE FORECAST AREA. MUCH OF
THIS QPF IS A RESULT OF AN ISENTROPIC LIFT / WARM ADVECTION REGIME
DEVELOPING DOWNSTREAM OF THE ARIZONA UPPER LOW...WHICH BY 12Z
SATURDAY IS PROGGED TO BE IN WEST TEXAS. ADDITIONALLY...WE HAVE THAT
UPPER LOW NEAR DENVER COMING THROUGH TO ADD IN SOME DPVA FORCING.
HAVE ADDED 20-40 PERCENT CHANCES INTO THE FORECAST FOR THIS FEATURE
AND THESE MAY NEED TO BE INCREASED LATER TODAY. MUCH OF THE LIFT IS
TAKING PLACE BETWEEN 10 KFT-15 KFT...BUT ENOUGH LOW LEVEL SATURATION
OCCURS TO ALLOW SNOW TO REACH THE SURFACE. IT SHOULD BE
NOTED...THOUGH...AS WE APPROACH 12Z THE ICE BEGINS TO EXITS THE
CLOUDS IN BOTH THE 02.00Z/06Z NAM AND GFS. SO...ANY LINGERING LIFT
APPROACHING THIS TIME COULD RESULT IN FREEZING DRIZZLE. HAVE ADDED
THIS POTENTIAL TO THE FORECAST. PROBABILITY FOR THIS FREEZING
DRIZZLE IS TOO LOW FOR AN ADVISORY AT THIS TIME.
WITH THE WARM ADVECTION REGIME DEVELOPING OVER THE NEXT 24 HOURS...
THE ARCTIC AIR TRYING TO SPILL INTO FAR NORTHERN SECTIONS OF THE
FORECAST AREA RIGHT NOW WILL STRUGGLE MAKING IT FARTHER SOUTH. IN
FACT...BY 00Z THIS EVENING...925MB TEMPS ALREADY ARE PROGGED FROM
-5C SOUTHWEST TO -9C NORTHEAST. WITH WHAT SHOULD BE A MOSTLY SUNNY
DAY...ANTICIPATE HIGHS CAN TOP OUT IN THE TEENS OVER TAYLOR/CLARK
COUNTIES TO THE 20S OVER THE REST OF THE SNOW PACK AREAS...AND LOW
30Z OVER SNOW FREE AREAS. WARM ADVECTION PERSISTS TONIGHT...WHICH
WITH CLOUDS INCREASING OVERNIGHT SHOULD HELP SOMEWHAT ON
TEMPERATURES. HOWEVER...WITH A MOSTLY CLEAR EVENING AND A WEAK
GRADIENT...READINGS COULD DROP INTO THE SINGLE DIGITS OVER
TAYLOR/CLARK TO THE TEENS TO LOW 20S ELSEWHERE.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 301 AM CST FRI JAN 2 2015
THE FOCUS FOR SATURDAY AND SATURDAY NIGHT CONTINUES TO REVOLVE
AROUND THE CURRENT UPPER LOW IN ARIZONA AND THE SHORTWAVE TROUGH
OVER BRITISH COLUMBIA. IT APPEARS THE MAIN ROLE OF THE BRITISH
COLUMBIA SHORTWAVE IS TO SERVE AS A KICKER FOR THE UPPER LOW. GOOD
MODEL CONSENSUS EXISTS FOR THE UPPER LOW TO TRACK THROUGH THE
DAVENPORT IA AREA AROUND 06Z SUNDAY AND INTO LOWER MICHIGAN BY 12Z
SUNDAY. HOWEVER...THE BRITISH COLUMBIA TROUGH DOES SPLIT APART WITH
A SHORTWAVE THAT COMES OFF IT WHICH MODELS BRING THROUGH THE
FORECAST AREA SATURDAY NIGHT. THAT SHORTWAVE EVENTUALLY PHASES WITH
THE UPPER LOW OVER LOWER MICHIGAN...RESULTING IN A DEEPENING SURFACE
LOW WELL OFF TO OUR EAST.
THE ISENTROPIC LIFT REGIME THAT DEVELOPED TONIGHT LOOKS TO PERSIST
THROUGH SATURDAY...THOUGH MAINLY FOCUSED OVER THE SOUTHEAST 1/3 TO
1/2 OF THE FORECAST AREA. THUS...THIS IS WHERE THE MAIN FOCUS FOR
PRECIPITATION EXISTS. AGAIN...BOTH THE 02.00Z NAM AND GFS POINT TO
WAVES OF ICE IN AND OUT OF THE CLOUDS...THUS THE FORECAST INCLUDES A
MENTION OF BOTH SNOW AND DRIZZLE/FREEZING DRIZZLE. WITH A GREATER
CHANCE FOR PRECIPITATION...MAY NEED AN ADVISORY FOR THIS WINTRY MIX
ASPECT. BEING DURING THE DAYTIME AND TEMPERATURES PERHAPS CLIMBING
ABOVE THE FREEZING MARK...THIS SHOULD HELP LIMIT ICE ACCUMULATION.
PRECIPITATION CHANCES INCREASE ACROSS THE ENTIRE FORECAST AREA
SATURDAY NIGHT WITH THE CROSSING OF THE SHORTWAVE AND BRUSH BY FROM
THE UPPER LOW. THE DEFORMATION SNOW BAND ACCOMPANYING THE NORTHWEST
SIDE OF THE DEEPENING SURFACE LOW MAY CLIP THE SOUTHEAST 1/3 OF THE
FORECAST AREA...THUS HIGHEST PRECIPITATION CHANCES AND QPF ARE
CONFINED THERE. PRECIPITATION SHOULD DIMINISH WEST TO EAST QUICKLY
LATE IN THE NIGHT AS SUBSIDENCE AND MUCH COLDER AND DRIER AIR ADVECT
IN. SNOWFALL AMOUNTS OVERALL HAVE COME DOWN QUITE A BIT WITH THE
02.00Z CYCLE...INCLUDING WITH THE 02.00Z ECMWF. THIS DECLINE IS A
COMBINATION OF THE AFOREMENTIONED WINTRY MIX AND MODELS NOT NEARLY
AS IMPRESSIVE WITH THE DEFORMATION BAND. IT SHOULD BE NOTED THAT THE
02.06Z NAM AND TO SOME DEGREE THE 02.00Z ECMWF HAVE THE DEFORMATION
BAND MISS MUCH OF THE FORECAST AREA...WITH MUCH OF THE PRECIP FOCUS
ON THE SNOW ACCOMPANYING THE SHORTWAVE. IF THIS HAPPENS...EVEN LESS
SNOW WILL FALL OVER THE SOUTHEAST 1/2 OF THE AREA.
FOCUS FOR THE REST OF THE FORECAST TURNS TO ARCTIC AIR. WE HAVE TWO
BIG BLASTS TO CONTEND WITH...THE FIRST COMING IN LATE SATURDAY NIGHT
AND THE SECOND COMING IN TUESDAY NIGHT. BOTH BLASTS HAVE A 35-45 KT
925MB WINDS CORE COMING ACROSS...WHICH MEANS THERE IS POTENTIAL WIND
SPEEDS COULD TRY TO APPROACH ADVISORY CRITERIA. HOWEVER...THE ARCTIC
AIR ACCOMPANYING THE WIND WILL FORCE WIND CHILL AS THE BIGGER
HAZARD. HOW COLD WE GET WILL DEPEND SOMEWHAT ON HOW MUCH SNOW WE GET
OVER THE NEXT FEW DAYS GIVEN THE LACK OF SNOW OVER THE SOUTHEAST
HALF OF THE FORECAST AREA. DETAILS...925MB TEMPS FALL FROM -4 TO -9C
AT 06Z SUNDAY TO -23 TO -26C BY 00Z MONDAY AND -26 TO -30C BY 12Z
MONDAY...WHICH MEANS TEMPERATURES SHOULD JUST FALL THROUGH THE DAY
SUNDAY...WITH MUCH OF THE NORTHWEST HALF BELOW ZERO FOR MUCH OF THE
DAY. WIND CHILL ADVISORIES LOOK LIKELY FOR THE NORTHWEST HALF ON
SUNDAY...EXPANDING EVERYWHERE SUNDAY NIGHT INTO MONDAY WITH MAYBE
SOME WARNINGS FOR TAYLOR/CLARK AND SOUTHEAST MN. THERE IS A BRIEF
WARM UP FOR MONDAY NIGHT INTO TUESDAY AS A NORTHWEST FLOW SHORTWAVE
TROUGH AND SYSTEM MOVE THROUGH THE REGION. PRECIPITATION CHANCES ARE
INCLUDED FOR THE SNOW ASPECT FOR THIS SYSTEM...WHICH COULD BE
ADVISORY WORTHY FOR SOME FLUFFY SNOW. THEN THE NEXT ARCTIC BLAST
FOLLOWS IN ITS WAKE FOR TUESDAY NIGHT AS A VERY DEEP TROUGH DROPS
INTO THE WESTERN GREAT LAKES. 925MB TEMPS PLUMMET FROM -14 TO -18C
AT 18Z TUESDAY TO AGAIN -26 TO -30C BY 12Z WEDNESDAY. WIND CHILL
ADVISORIES AND WARNINGS ARE LIKELY TO BE NEEDED. TEMPERATURES MAY
STRUGGLE TO CLIMB MUCH WEDNESDAY. LOWERED HIGHS SOME AND THESE MAY
NEED FURTHER LOWERING. ON A POSITIVE NOTE...MASSIVE WARM ADVECTION
IS PROGGED FOR WEDNESDAY NIGHT AND THURSDAY AS THE DEEP TROUGH MOVES
WELL OFF TO THE EAST. SO HIGHS SHOULD REBOUND NICELY FOR
THURSDAY...BUT STILL BELOW NORMAL.
INTERESTINGLY...THIS ARCTIC OUTBREAK FOR SUNDAY...MONDAY AND
WEDNESDAY ENDS UP BEING AT EXACTLY THE SAME TIME AS LAST YEARS
ARCTIC OUTBREAK. WIND CHILLS MAY NOT BE AS COLD...SINCE 925MB
TEMPS ARE A LITTLE WARMER THAN LAST YEARS ARCTIC OUTBREAK...BUT
ITS STILL LOOKS DANGEROUSLY COLD FOR SOME OF THIS TIME.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1105 AM CST FRI JAN 2 2015
ROUGHLY 2500 FT CLOUD DECK HAS FINALLY CREPT ACROSS KRST LATE THIS
MORNING...BUT ITS EASTWARD PROGRESSED HAS SLOWED SIGNIFICANTLY.
TRENDS FAVOR THE 925 MB FLOW TO STEER THIS MVFR DECK MORE NORTHEAST
DURING THE AFTERNOON...SPARING KLSE FOR THE MOST PART. COULD STILL
SEE A PERIOD OF BKN CIGS LATER IN THE AFTERNOON...BUT CLOSER TO 3
KFT. ANTICIPATE THIS STRATUS TO LIFT NORTH OF BOTH KRST/KLSE BY MID
EVENING.
IFR/MVFR LOW CLOUDS WILL RETURN QUICKLY FROM THE SOUTH AFTER 06Z
TONIGHT THOUGH...WITH SOME ISENTROPIC UPGLIDE PROVIDING SOME LIFT IN
THE CLOUD LAYER. BUFKIT SOUNDINGS SUGGEST A POTENTIAL FOR ICE/NO ICE
IN THE CLOUDS...MAKING SNOW/FREEZING DRIZZLE POSSIBLE. THE PARENT
LOW PRESSURE SYSTEM IS WELL TO THE SOUTHEAST...AND EXPECT THE LIGHT
PCPN CHANCES TO AVOID KRST. WILL ADD A MENTION FOR -FZDZSN IN FOR
KLSE. ACCUMULATIONS OF EITHER PCPN TYPE LOOK MINOR. THE LOW CIGS
WILL HANG AROUND SAT...AND COULD SEE SOME MVFR REDUCTIONS IN VSBYS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM....AJ
AVIATION.....RIECK