Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 12/30/14
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1218 AM EST SUN DEC 28 2014
.SYNOPSIS...
A COLD FRONT WILL CROSS THE AREA TOMORROW, THEN STALL TO OUR SOUTH
AS A WEAK LOW PRESSURE SYSTEM RIDES ALONG IT MONDAY AND MONDAY
NIGHT. IN THE WAKE OF THE FRONT, A COLD AIR MASS SLIDES SOUTH AND
SETTLES IN OVER THE REGION THROUGH NEW YEARS DAY. ON FRIDAY, A
LOW PRESSURE SYSTEM COULD DEVELOP OVER THE SOUTHERN PLAINS AND
BEGIN LIFTING NORTHEAST TOWARDS THE REGION TO START THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
NO BIG CHANGES WITH THIS UPDATE EITHER, JUST SLIGHT POP
ADJUSTMENTS BASED ON LATEST RAP AND HRRR BLEND.
OVERALL, NO BIG CHANGES TO THE FORECAST TONIGHT. MOSTLY HOURLY
GRID ADJUSTMENTS MADE, BUT WE DID MAKE SOME CHANGES TO THE
OVERNIGHT LOWS FOR SOME AREAS. MAINLY PORTIONS OF THE PINE
BARRENS AND NORTHERN NEW JERSEY WHERE TEMPERATURES HAVE ALREADY
RADIATED QUITE EFFICIENTLY. OTHERWISE, FORECAST LOOKS ON TRACK.
LIGHT SOUTHWESTERLY WINDS WILL CONTINUE TO USHER IN A SOMEWHAT
MOISTER AIRMASS, AHEAD OF AN APPROACHING COLD FRONT. SKIES WILL
CONTINUE TO THICKEN AND LOWER WITH TIME. THE POSITION OF THE FRONT
LOOKS TO BE JUST TO OUR WEST RIGHT AROUND SUNRISE SUNDAY
MORNING...THIS IS WHEN WE INCREASE POPS INTO THE LIKELY RANGE.
THERMAL PROFILES SHOW ALL AN LIQUID PTYPE FOR THE REGION AS
SURFACE TEMPERATURES WILL ONLY DROP INTO THE MID TO UPPER-30S IN A
LOT OF PLACES EXCEPT WHERE THEY HAVE RADIATED MORE ALREADY.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM MONDAY/...
COLD FRONT WILL WORK ITS WAY THROUGH THE REGION FROM LATE MORNING
THROUGH THE EVENING HOURS. HAVE INCREASE POPS TO CATEGORICAL FOR AT
LEAST THE SOUTHERN HALF OF THE CWA BY SUNDAY AFTERNOON. SOME WEAK
MID-LEVEL ENERGY SLIDES ALONG THE FRONT LATER TOMORROW AFTERNOON
WHICH COULD ULTIMATELY SLOW ITS DEPARTURE DOWN A BIT. A MAJORITY OF
THE GUIDANCE HAS US DRYING OUT FROM NORTHWEST TO SOUTHEAST BY LATE
SUNDAY EVENING, JUST AHEAD OF THE BETTER LOW-LEVEL CAA KICKING IN.
THERE COULD BE SOME RAIN/SNOW MIX ACROSS OUR NORTHWEST ZONES LATE IN
THE PERIOD, DEPENDING ON HOW FAST WE CAN COOL BELOW 850MB AND HOW
MUCH MOISTURE REMAINS. TEMPERATURES WILL BE ABOVE NORMAL ONCE AGAIN
THOUGH SEVERAL DEGREES COOLER THAN TODAY WITH THE AMOUNT OF CLOUD
COVER EXPECTED AND THE RAIN SHOWERS MOVING IN.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
STILL A VERY LOW CONFIDENCE FORECAST IN THE WAKE OF THE COLD FRONT
FROM SUNDAY NIGHT THROUGH TUESDAY. MOST MODELS DID AGREE ON ONE
THING, THEY ARE MOSTLY FOR LOCATIONS GENERALLY ALONG AND NORTH OF
A PHILLY TO ACY LINE. NAM IS BY FAR THE WETTEST AND SNOWIEST
OUTLIER SHOWING SNOW FOR NEARLY ALL OF THE REGION. GIVEN THAT THE
TREND WITH THE OTHER MODELS HAS BEEN DRIER FOR A FEW RUNS NOW, AND
GIVEN HOW MUCH OF AN OUTLIER THE NAM IS, FORECAST FAVORS THE GFS
AND ECMWF. THEY BOTH SHOW THE FRONT PUSHING FURTHER SOUTH BEFORE
STALLING, WITH THE FRONT NOW EXPECTED TO STALL OR SLOW BY LATE
MONDAY AFTERNOON GENERALLY FROM THE FL PANHANDLE TO THE SC COAST.
AS A RESULT, BUT THE TIME THE SECONDARY LOW DEEPENS AND LIFTS NE
ALONG THE FRONT, IT IS MUCH FURTHER OUT TO SEA THAN WHAT PREVIOUS
RUNS SHOWED.
EVEN IN DELMARVA THOUGH, THIS DOESN/T APPEAR TO BE A MAJOR EVENT
AS WHEN THE MOISTURE IS THE MOST ABUNDANT, SUNDAY NIGHT, IT WILL
STILL BE WARM ENOUGH TO SUPPORT RAIN. BY MONDAY AFTERNOON INTO
MONDAY NIGHT, COLDER AIR HAS SETTLED IN, BUT SO HAS DRY AIR
ADVECTION, LIMITING MOISTURE AVAILABILITY. SO DO NOT EXPECT ANY
ACCUMULATIONS ABOVE AN INCH.
FOR MUCH OF THE REST OF THE WEEK, THE WEATHER LOOKS TRANQUIL,
ALBEIT COLD. THE CONTINENTAL POLAR AIR MASS CONTINUES TO SETTLE IN
OVER THE REGION. AS SUCH MANY LOCATIONS NORTHWEST OF THE FALL LINE
WILL STRUGGLE TO GET ABOVE FREEZING FROM TUESDAY THROUGH FRIDAY.
THE NEXT THING ON THE HORIZON IS AN INTENSE LOW, MODELED TO
BE OVER THE SOUTHERN PLAINS BY FRIDAY LIFTING TOWARDS THE GREAT
LAKES REGION. GIVEN HOW MUCH UNCERTAINTY THERE IS EARLY IN THE
WEEK, AND GIVEN A LARGE SPREAD IN TIMING AND TRACK BETWEEN THE GFS
AND ECMWF, IT/S RISKY TO HANG A HAT ON EITHER SOLUTION. HOWEVER,
IT DOES APPEAR THAT THE IMPACTS TO THIS REGION WILL BE A CHANCE
FOR PRECIPITATION, PRIMARILY WITHIN THE WARM SECTOR OF THIS LOW AS
IT STAYS NW OF THE REGION (MEANING PRIMARILY RAIN). WILL HAVE A
CHANCE TO REFINE THIS ONCE WE SEE HOW THE EARLY WEEK SYSTEM PLAYS
OUT.
&&
.AVIATION /05Z SUNDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
06Z TAFS CONTAIN MVFR CONDITIONS MAINLY DURING MORE FREQUENT
SHOWERS DURING THE DAYTIME HOURS.
EARLY MORNING, VFR SHOWERS MOVING INTO NORTHERN TERMINALS TOWARD
DAWN. SOME MVFR FOG AT KILG, SHOULD DISSIPATE AS CLOUDS BECOME
THICKER. OTHERWISE A VFR CIG WITH LIGHT WINDS.
THIS MORNING AND AFTERNOON...NORTHERN AIRPORTS AND TERMINALS VFR
SHOWERS SHOULD BE ONGOING TERMINALS WITH CIGS LOWERING TO MVFR
LATER IN THE MORNING. VFR CIG IMPROVEMENT DURING THE AFTERNOON.
KPHL AREA AIRPORTS AND TERMINALS/AIRPORTS TO THE SOUTH/SOUTHEAST
EXPECTING A VFR CIG MORNING WITH SHOWERS OCCURRING MAINLY DURING
THE AFTERNOON. MVFR CIGS ARE POSSIBLE DURING THE AFTERNOON.
ALL TERMINALS VSBY RESTRICTIONS TOO BRIEF TO INCLUDE, MAINLY VFR
VSBYS. WINDS WILL BECOME WEST TO NORTHWEST DURING THE LATE MORNING
TO EARLY AFTERNOON AS THE COLD FRONT MOVES THROUGH. SPEEDS SHOULD
BE LESS THAN 10 KNOTS.
THIS EVENING. VFR MID LEVEL CIGS. NORTHWEST WINDS AVERAGING 5 TO
10 KNOTS. SOUTHERN TERMINALS AND DELMARVA AIRPORTS MIGHT SEE A
SECOND SURGE OF MAINLY VFR RAIN LATE AT EVENING AND OVERNIGHT.
OUTLOOK...
MONDAY TO TUESDAY....MOSTLY VFR CONDITIONS EXPECTED ALONG AND
NORTH OF A KACY TO KPHL LINE. FOR KMIV AND KILG, THERE IS A CHANCE
FOR PRECIPITATION, SOME OF WHICH COULD FALL AS SNOW. MVFR
CONDITIONS ARE POSSIBLE WITH ANY PRECIP.
TUESDAY NIGHT THROUGH THURSDAY...MOSTLY VFR CONDITIONS EXPECTED
ACROSS THE REGION.
&&
.MARINE...
TONIGHT - SUNDAY...SUB-SCA CONDITIONS EXPECTED. SEAS WILL CONTINUE
AROUND 3 FEET THROUGH LATE THIS EVENING BEFORE AN INCREASE TO AROUND
4 FEET IS POSSIBLE...BETTER FARTHER NORTH. WINDS WILL REMAIN
RELATIVELY LIGHT OUT OF THE SOUTH-SOUTHWEST AROUND 10 TO MAYBE 15
KNOTS, THOUGH GUSTS SHOULD BE KEPT BELOW 20 KNOTS. WINDS BACK TOWARDS
THE WEST LATER TOMORROW EVENING AS A SURFACE COLD FRONT MOVES
THROUGH.
OUTLOOK...
MONDAY THROUGH TUESDAY...CONDITIONS SHOULD STAY BELOW SCA
THRESHOLDS. HOWEVER, WAVES OF 3 TO 4 FT, AND WIND GUSTS NEAR OR
JUST ABOVE 20KT WILL BE POSSIBLE ESPECIALLY LATE MONDAY NIGHT INTO
TUESDAY.
TUESDAY NIGHT THROUGH THURSDAY...SUB SMALL CRAFT ADVISORY
CONDITIONS EXPECTED.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JOHNSON
NEAR TERM...GIGI/HEAVENER/ROBERTSON
SHORT TERM...HEAVENER
LONG TERM...JOHNSON
AVIATION...GIGI/JOHNSON
MARINE...HEAVENER/JOHNSON
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
200 PM EST SUN DEC 28 2014
.SYNOPSIS...
19Z WATER VAPOR AND H4 RAP ANALYSIS SHOW THE FLORIDA PENINSULA UNDER
THE PROTECTIVE COVER OF A LARGE MID/UPPER LEVEL RIDGE CENTERED NEAR
THE BAHAMAS. OUR DEEP LAYER FLOW ALOFT IS FROM THE SOUTH AND
SOUTHWEST BETWEEN THIS FEATURE AND A POTENT TROUGH/SHORTWAVE FEATURE
EJECTING QUICKLY EASTWARD ACROSS THE SOUTHERN PLAINS/NORTHERN
MEXICO. FINALLY FURTHER UPSTREAM WE SEE A SIGNIFICANT PIECE OF
ENERGY/JET STREAK DIVING DOWN OVER THE PACIFIC COAST. THROUGH THE
EARLY PORTION OF THE WEEK...OUT WEATHER WILL BE DETERMINED BY THE
INTERACTION BETWEEN THE RIDGE TO OUR SOUTH AND EAST...AND THE
APPROACHING SHORTWAVE FROM THE WEST.
AT THE SURFACE...ATLANTIC HIGH PRESSURE RIDGES BACK WEST INTO THE
FLORIDA PENINSULA AND EASTERN GULF...AND SHOULD HOLD IN PLACE
THROUGH MONDAY. TEMPERATURES HAVE WARMED INTO THE4 LOWER 80S INLAND
AND GENERALLY IN THE 70S AT THE COAST. ONLY EXCEPTION IS ALONG THE
IMMEDIATE COAST OVER THE FAR NORTHERN ZONES WHERE THE ONSHORE FLOW
IS OFF OF QUITE COOL SHELF WATERS. THE OBSERVATION AT CEDAR KEY IS
ONLY IN THE MIDDLE 60S. THESE TEMPS IN THE 60S ARE LIKELY CONFINED
TO ONLY A MILE OR TWO FROM THE WATER WITH TEMPERATURES RAPIDLY
WARMING WITH INLAND EXTENT.
&&
.SHORT TERM (REST OF TODAY THROUGH MONDAY)...
REST OF TODAY...
THE STRONG TERRESTRIAL HEATING AND GENERALLY WEAK GRADIENT HAVE
ALLOWED A FEEBLE SEA-BREEZE TO DEVELOP ALONG THE COAST THIS
AFTERNOON. THIS SEA-BREEZE WILL KEEP THE BEACHES A BIT COOLER
COMPARED WITH INLAND LOCATIONS AS THE FLOW IS OFF THE RELATIVELY
COOLER SHELF WATERS. THE FORECAST THE REST OF THE DAY IS FOR RAIN
FREE CONDITIONS DUE TO THE GENERALLY DRY COLUMN ALOFT AND NO
SYNOPTIC SUPPORT FOR LIFT IN THE VICINITY. THERE IS A COLD FRONT
STRETCHED ACROSS THE SOUTHEAST PORTION OF THE COUNTY THAT IS
BRINGING SHOWERS INTO THE FLORIDA PANHANDLE/AL/GA...HOWEVER THE
STRONG UPPER RIDGE WILL NOT ALLOW THIS FEATURE TO MOVE VERY FAR
THROUGH TONIGHT AND IT WILL NOT BE A CONCERN FOR OUR FORECAST TILL
AT LEAST TUESDAY.
TONIGHT...
FAIR AND DRY CONDITIONS CONTINUE. SHORTWAVE ENERGY WILL BE RAPIDLY
APPROACHING THE SOUTHEAST CONUS. HOWEVER...AS IT APPROACHES...THIS
ENERGY WILL BE QUICKLY SHEARING OUT AND DEAMPLIFYING. ABOUT THE ONLY
EFFECT THIS FEATURE WILL HAVE ON OUR LOCAL WEATHER THROUGH TONIGHT
WILL BE TO BREAK DOWN/DEAMPLIFY THE UPPER RIDGE AND BEGIN TO TURN
OUR SYNOPTIC FLOW ALOFT MORE ZONAL IN NATURE. THE SURFACE FRONT WILL
GET A LITTLE "KICK" EASTWARD WITH THE PASSING ENERGY...BUT SHOULD BE
STALLED NEAR APALACHEE BAY BY MONDAY MORNING. WE DO ANTICIPATE SOME
ADDITIONAL FOG/VISIBILITY ISSUES TONIGHT INTO EARLY MONDAY
MORNING...HOWEVER WITH THE RIDGE BREAKING DOWN OVERNIGHT...THE
SYNOPTIC SETUP FOR WIDESPREAD DENSE FOG DOES NOT LOOK AS FAVORABLE.
WILL GO WITH AREAS OF FOG...SOME OF WHICH SHOULD BECOME LOCALLY
DENSE. UNFORTUNATELY...MANY OF OUR AIRPORTS ARE IN LOWER/MORE FOG
PRONE LOCATIONS AND WILL PROB BE IMPACTED BY ANOTHER ROUND OF FLIGHT
RESTRICTIONS EARLY MONDAY.
MONDAY...
MORE OF THE SAME. AREAS OF FOG WILL SLOWLY BURN OFF BETWEEN 13-15Z.
THE UPPER RIDGE WILL BE DEAMPLIFIED...HOWEVER THE LOWER COLUMN WILL
STILL BE VERY WARM AND SUFFICIENT TO KEEP OUR TEMPS WELL ABOVE
AVERAGE. WOULD EXPECT LOWER 80S FOR HIGHS SOUTH OF THE I-4 CORRIDOR
AND AWAY FROM THE IMMEDIATE COAST. COULD CERTAINLY SEE LOWER 80S
FURTHER NORTH...HOWEVER ANTICIPATING A BIT MORE IN THE WAY OF CLOUDS
FOR CENTRAL AND NORTHERN PORTIONS OF THE STATE AND HENCE TEMPS MAY
BE HELD DOWN IN THE MID/UPPER 70S. THE FRONT LOOKS TO REMAIN
QUASI-STATIONARY UP ACROSS APALACHEE BAY SINCE THERE WILL STILL BE
LITTLE IN THE WAY OF ATMOSPHERIC PUSH. THE PROXIMITY OF THE FOCUS
ALONG THE BOUNDARY MAY BE ENOUGH TO SUPPORT A FEW SHOWERS UP TO LEVY
COUNTY...BUT OTHERWISE CONDITIONS ARE EXPECTED TO REMAIN DRY. THE
ONLY OTHER LOCATION THAT RUNS THE RISK OF A BRIEF AFTERNOON SHOWER
LOOKS TO BE AROUND HIGHLANDS COUNTY WHERE A FEW OF THE HIRES
EXPLICIT CONVECTION GUIDANCE MEMBERS ARE FOCUSING A FEW CONVECTIVE
CELLS AFTER 18Z ASSOCIATED WITH A SEA-BREEZE MERGER. GIVEN THE
COLUMN CHARACTERISTICS FOR TOMORROW...CAN NOT RULE OUT THE SUPPORT
FOR A BRIEF CONVECTIVE UPDRAFT AND WILL ADD A 20% POP FOR A SHOWER
OVER THE INLAND SOUTH-CENTRAL ZONES...EVEN THOUGH MOST SPOTS WILL
NOT SEE ANYTHING. EVEN UP TOWARD LEVY COUNTY WE DO NOT EXPECT ENOUGH
RAIN TO SERIOUSLY HAMPER ANY OUTDOOR EVENTS/ACTIVITIES. BEST RAIN
CHANCES ON MONDAY WILL STAY OFF TO THE NORTH AND NORTHWEST OF OUR
ZONES.
THE WEAK PASSING IMPULSE THAT FINALLY "SHOVES" THE FRONT DOWN INTO
THE FL PENINSULA IS ON TUESDAY...AND IT WILL BE AT THAT TIME THAT
LOW SHOWER CHANCES RETURN TO THE FORECAST FOR MOST OF US. HAVE A
GREAT SECOND HALF OF YOUR WEEKEND. GET OUTSIDE AND ENJOY THE WARM
LATE DECEMBER WEATHER!
&&
LONG TERM (TUESDAY THROUGH NEXT SUNDAY)...
THE PERIOD BEGINS ALOFT WITH A SHORT WAVE TROUGH ROUGHLY WEST TO
EAST ACROSS THE NORTHERN U.S. ROCKIES WHILE A ROBUST ATLANTIC
SUBTROPICAL RIDGE REACHED IN ACROSS THE SOUTHERN GULF OF MEXICO AND
THE NORTHWESTERN CARIBBEAN SEA. AT THE SURFACE HIGH PRESSURE
SPRAWLED ACROSS THE CANADIAN PRAIRIES AND THE NORTHERN AND CENTRAL
U.S. PLAINS WITH A LOW PRESSURE CENTER OFF THE MID-ATLANTIC COAST
THAT TRAILED A WEAK COLD FRONT BACK ACROSS SOUTH GA/NORTH FL INTO
THE GULF OF MEXICO.
WITH TIME THE SHORT WAVE TROUGH DROPS SOUTH ALONG THE SIERRA NEVADA
RANGE THEN DEEPENS INTO A CLOSED LOW AS IT TRACKS ACROSS THE GREAT
BASIN TO THE CENTRAL HIGH PLAINS. THE GULF AND CARIBBEAN RIDGE
BUILDS NORTHWARD OVER THE EASTERN STATES. MEANWHILE THE FRONT
SETTLES SOUTHWARD ACROSS THE REST OF FL AS IT SLOWLY DISSIPATES BY
WED AS THE SURFACE HIGH RELOCATES TO THE CENTRAL U.S. PLAINS AND
BUILDS OVER MUCH OF THE EASTERN CONUS.
DURING THE WEEKEND THE UPPER LOW OPENS INTO A TROUGH THAT TRACKS
NORTHEAST ACROSS THE GREAT LAKES INTO SOUTHEAST CANADA...ALONG WITH
A SURFACE REFLECTION TRAILING A COLD FRONT THAT GETS STRUNG OUT
ALONG THE EASTERN SEABOARD INTO THE CENTRAL GULF OF MEXICO. THE
RIDGING...BOTH ALOFT AND SURFACE...PIVOTS OUT OVER THE ATLANTIC AS
IT HANGS ON OVER MUCH OF BOTH FL AND THE GULF.
WHILE THE REST OF THE NATION WILL HAVE AN ACTIVE PATTERN THERE WILL
BE LIMITED IMPACT ACROSS WEST CENTRAL AND SOUTHWEST FL. THE FIRST
FRONT COMES THROUGH WITH ONLY SLIGHT CHANCE TO CHANCE SHOWERS MAINLY
TUE. THEN DRY CONDITIONS GENERALLY PREVAIL AS THE SECOND FRONT STAYS
TO THE NORTH THROUGH THE WEEKEND. HOWEVER...THE FRONT WILL BE CLOSE
ENOUGH FOR SOME ENERGY TO COMBINE WITH INCREASING MOISTURE ON
SOUTHERLY FLOW TO SUPPORT LOW CHANCE SHOWERS ACROSS THE NORTH SAT
AND SUN. TEMPERATURES INITIALLY ABOVE NORMAL COOL DOWN SLIGHTLY
MID-WEEK...AFTER THE FRONT MOVES THROUGH AND HIGH PRESSURE BUILDS IN
TO THE NORTHWEST AND NORTH. FOR THE END OF WEEK AND THE WEEKEND
TEMPERATURES REMAIN ABOVE NORMAL AND SLOWLY WARM AS THE HIGH MOVES
BY TO THE NORTH THEN NORTHEAST WITH LOW LEVEL EVENTUALLY VEERING TO
SOUTHERLY.
&&
AVIATION...
VFR CONDITIONS ARE GENERALLY PREVAILING ACROSS THE REGION THIS
AFTERNOON AND EXPECT THAT TREND TO CONTINUE THROUGH THE EVENING.
WINDS ARE LIGHT SOUTHERLY INLAND AND HAVE BECOME ONSHORE NEAR THE
COAST. WINDS WILL DISSIPATE AND BECOME LIGHT VARIABLE SHORTLY AFTER
SUNSET. AREAS OF FOG ARE EXPECTED TO ONCE AGAIN DEVELOP AFTER
MIDNIGHT AND LINGER THROUGH MID-MORNING MONDAY. ALTHOUGH NOT
EXPECTED TO BE AS WIDESPREAD AS SATURDAY NIGHT...THE POTENTIAL FOR
SEVERAL HOURS AT IFR OR LOWER DOES EXIST. MOST LIKELY SPOTS TO SEE
THE SIGNIFICANT RESTRICTIONS WILL BE KLAL...KPGD...KRSW AND KFMY.
ONCE THE FOG LIFTS BY 14-15Z MONDAY...VFR CONDITIONS ARE EXPECTED
FOR THE REMAINDER OF THE DAY.
&&
MARINE...
LIGHT SOUTH SOUTHEAST WINDS ON THE BACK SIDE OF HIGH PRESSURE OVER
THE WESTERN ATLANTIC WILL CONTINUE FOR THE NEXT COUPLE OF DAYS OVER
THE COASTAL WATERS. SEA FOG WILL BE POSSIBLE TODAY AND MONDAY WITH A
WARM AND HUMID AIR MASS OVERRIDING THE RELATIVELY COOLER WATERS. A
WEAK FRONTAL BOUNDARY APPROACHES THE AREA ON MONDAY AND TUESDAY
KEEPING THE SOUTHERLY WIND FLOW IN PLACE AND PRODUCING A SLIGHT
CHANCE OF SHOWERS. THE WINDS WILL SHIFT TO THE NORTH NORTHEAST IN
THE WAKE OF THIS FRONT ON TUESDAY...AND WILL REMAIN OUT OF THE
NORTHEAST THROUGH THE WEEK AS HIGH PRESSURE SETTLES INTO THE REGION.
&&
.FIRE WEATHER...
NO SIGNIFICANT FIRE WEATHER CONCERNS FOR THE NEXT COUPLE OF DAYS
OTHER THAN AREAS OF DENSE FOG EXPECTED LATER TONIGHT INTO MONDAY
MORNING. RELATIVE HUMIDITY VALUES WILL REMAIN WELL ABOVE CRITICAL
LEVELS THROUGH TUESDAY WITH JUST A FEW SHOWERS AROUND ON TUESDAY.
FOG POTENTIAL...ALTHOUGH NOT EXPECTED TO BE AS WIDESPREAD AS
SATURDAY NIGHT...AREAS OF FOG ARE EXPECTED TO DEVELOP OVERNIGHT INTO
EARLY TUESDAY MORNING AND SOME OF THE FOG IS LIKELY TO BECOME DENSE.
DENSE FOG ADVISORIES MAY BECOME REQUIRED FOR SOME AREAS AFTER
MIDNIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 65 77 66 77 / 0 10 10 20
FMY 66 80 66 81 / 0 10 20 10
GIF 64 80 64 78 / 0 10 10 20
SRQ 64 77 65 76 / 0 10 10 10
BKV 60 79 63 77 / 0 10 20 20
SPG 66 76 66 76 / 0 10 20 10
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/AVIATION/FIRE WX...MROCZKA
MARINE...WYNN
LONG TERM...RUDE
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
1045 AM EST SUN DEC 28 2014
UPDATE (REST OF TODAY THROUGH MONDAY)...
15Z WATER VAPOR AND H4 RAP ANALYSIS SHOW THE FLORIDA PENINSULA UNDER
THE PROTECTIVE COVER OF A LARGE MID/UPPER LEVEL RIDGE CENTERED NEAR
THE BAHAMAS. OUR DEEP LAYER FLOW ALOFT IS FROM THE SOUTH AND
SOUTHWEST BETWEEN THIS FEATURE AND A POTENT TROUGH/SHORTWAVE FEATURE
EJECTING QUICKLY EASTWARD ACROSS THE SOUTHERN PLAINS/NORTHERN
MEXICO. FINALLY FURTHER UPSTREAM WE SEE A SIGNIFICANT PIECE OF
ENERGY/JET STREAK DIVING DOWN OVER THE PACIFIC COAST. THROUGH THE
EARLY PORTION OF THE WEEK...OUT WEATHER WILL BE DETERMINED BY THE
INTERACTION BETWEEN THE RIDGE TO OUR SOUTH AND EAST...AND THE
APPROACHING SHORTWAVE FROM THE WEST.
AT THE SURFACE...ATLANTIC HIGH PRESSURE RIDGES BACK WEST INTO THE
FLORIDA PENINSULA AND EASTERN GULF...AND SHOULD HOLD IN PLACE
THROUGH MONDAY. THE COMBINATION OF THE UPPER RIDGE PRESSING DOWN
FROM ABOVE AND ABUNDANT LOW LEVEL MOISTURE MADE FOR WIDESPREAD DENSE
FOG AROUND THE AREA THIS MORNING. THE LATE DECEMBER SUN IS NOT THE
STRONGEST OF THE YEAR...BUT HAS BEEN DOING THE JOB OF BURNING OFF
THE THIN LAYER OF SURFACE FOG THE PAST FEW HOURS...AND THE DENSE FOG
ADVISORY HAS BEEN ALLOWED TO EXPIRE.
THE STABLE AND FOGGY NEAR SURFACE LAYER WAS WELL SAMPLED IN THE
28/12Z KTBW SOUNDING PROFILE...BUT ABOVE THIS LAYER WE SEE A
GENERALLY DRY ATMOSPHERE RELATED TO THE SUBSIDENCE INVERSION
LOCATED JUST ABOVE 900MB.
REST OF TODAY...
NOW THAT THE FOG HAS BURNED OFF WE CAN EXPECT A GOOD DEAL OF
SUNSHINE THE REST OF THE DAY...ALTHOUGH THE LOWER LEVEL MOISTURE AND
RISING THERMALS SHOULD ALLOW FOR A SCATTERED CUMULUS FIELD TO BECOME
ESTABLISHED DURING THE AFTERNOON. THE LOWER LEVELS OF THE ATMOSPHERE
ARE VERY WARM FOR LATE DECEMBER. THE 850MB TEMPERATURE OFF THE
MORNING SOUNDING WAS 17C. WITH THIS PROFILE...EVEN A MODEST AMOUNT
OF DIURNAL MIXING IS GOING TO MIX OUT OUR HIGH TEMPERATURES WELL
INTO THE 70S...AND LIKELY INTO THE 80S FOR MANY SPOTS AWAY FROM THE
IMMEDIATE COAST. THE STRONG TERRESTRIAL HEATING AND GENERALLY WEAK
GRADIENT SHOULD ALSO ALLOW A FEEBLE SEA-BREEZE TO DEVELOP ALONG THE
COAST THIS AFTERNOON. THIS SEA-BREEZE WILL KEEP THE BEACHES A BIT
COOLER COMPARED WITH INLAND LOCATIONS AS THE FLOW TURNS FROM OFF THE
RELATIVELY COOLER SHELF WATERS. THE FORECAST THE REST OF THE DAY IS
FOR RAIN FREE CONDITIONS DUE TO THE GENERALLY DRY COLUMN ALOFT AND
NO SYNOPTIC SUPPORT FOR LIFT IN THE VICINITY. THERE IS A COLD FRONT
STRETCHED ACROSS THE SOUTHEAST PORTION OF THE COUNTY THAT WILL BRING
SHOWERS INTO THE FLORIDA PANHANDLE/AL/GA TODAY...HOWEVER THE STRONG
UPPER RIDGE WILL NOT ALLOW THIS FEATURE TO MOVE VERY FAR THROUGH
TONIGHT AND IT WILL NOT BE A CONCERN FOR OUR FORECAST TILL AT LEAST
TUESDAY.
TONIGHT...
FAIR AND DRY CONDITIONS CONTINUE. SHORTWAVE ENERGY WILL BE RAPIDLY
APPROACHING THE SOUTHEAST CONUS. HOWEVER...AS IT APPROACHES...THIS
ENERGY WILL BE QUICKLY SHEARING OUT AND DEAMPLIFYING. ABOUT THE ONLY
EFFECT THIS FEATURE WILL HAVE ON OUR LOCAL WEATHER THROUGH TONIGHT
WILL BE TO BREAK DOWN/DEAMPLIFY THE UPPER RIDGE AND BEGIN TO TURN
OUR SYNOPTIC FLOW ALOFT MORE ZONAL IN NATURE. THE SURFACE FRONT WILL
GET A LITTLE "KICK" EASTWARD WITH THE PASSING ENERGY...BUT SHOULD BE
STALLED NEAR APALACHEE BAY BY MONDAY MORNING. WE DO ANTICIPATE SOME
ADDITIONAL FOG/VISIBILITY ISSUES TONIGHT INTO EARLY MONDAY
MORNING...HOWEVER WITH THE RIDGE BREAKING DOWN OVERNIGHT...THE
SYNOPTIC SETUP FOR WIDESPREAD DENSE FOG DOES NOT LOOK AS FAVORABLE.
WILL GO WITH AREAS OF FOG...SOME OF WHICH SHOULD BECOME LOCALLY
DENSE. UNFORTUNATELY...MANY OF OUR AIRPORTS ARE IN LOWER/MORE FOG
PRONE LOCATIONS AND WILL PROB BE IMPACTED BY ANOTHER ROUND OF FLIGHT
RESTRICTIONS EARLY MONDAY.
MONDAY...
MORE OF THE SAME. AREAS OF FOG WILL SLOWLY BURN OFF BETWEEN 13-15Z.
THE UPPER RIDGE WILL BE DEAMPLIFIED...HOWEVER THE LOWER COLUMN WILL
STILL BE VERY WARM AND SUFFICIENT TO KEEP OUR TEMPS WELL ABOVE
AVERAGE. WOULD EXPECT LOWER 80S FOR HIGHS SOUTH OF THE I-4 CORRIDOR
AND AWAY FROM THE IMMEDIATE COAST. COULD CERTAINLY SEE LOWER 80S
FURTHER NORTH...HOWEVER ANTICIPATING A BIT MORE IN THE WAY OF CLOUDS
FOR CENTRAL AND NORTHERN PORTIONS OF THE STATE AND HENCE TEMPS MAY
BE HELD DOWN IN THE MID/UPPER 70S. THE FRONT LOOKS TO REMAIN
QUASI-STATIONARY UP ACROSS APALACHEE BAY SINCE THERE WILL STILL BE
LITTLE IN THE WAY OF ATMOSPHERIC PUSH. THE PROXIMITY OF THE FOCUS
ALONG THE BOUNDARY MAY BE ENOUGH TO SUPPORT A FEW SHOWERS UP TO
LEVY COUNTY...BUT OTHERWISE CONDITIONS SHOULD BE DRY. EVEN UP TOWARD
LEVY COUNTY WE DO NOT EXPECT ENOUGH RAIN TO SERIOUSLY HAMPER ANY
OUTDOOR EVENTS/ACTIVITIES. BEST RAIN CHANCES ON MONDAY WILL STAY OFF
TO THE NORTH AND NORTHWEST OF OUR ZONES.
THE WEAK PASSING IMPULSE THAT FINALLY "SHOVES" THE FRONT DOWN INTO
THE FL PENINSULA IS ON TUESDAY...AND IT WILL BE AT THAT TIME THAT
SHOWER CHANCES RETURN TO THE FORECAST FOR MOST OF US. HAVE A GREAT
SECOND HALF OF YOUR WEEKEND. GET OUTSIDE AND ENJOY THE WARM LATE
DECEMBER WEATHER!
&&
LONG TERM (MONDAY NIGHT-FRIDAY)...
INTERESTING U/L PATTERN EVOLUTION ACROSS NORTH AMERICA THROUGH THE
LONG RANGE PERIOD...BUT WITH LITTLE IMPACT OVER WEST CENTRAL AND
SOUTHWEST FLORIDA AS A STRONG SUBTROPICAL RIDGE ANCHORED ACROSS THE
CARIBBEAN WILL KEEP THE MAIN WESTERLIES NORTH OF THE REGION.
A STRONG U/L RIDGE OVER THE EASTERN PACIFIC WILL EXTEND NORTH
THROUGH ALASKA ON TUESDAY. DOWNSTREAM...A POSITIVELY TILTED L/W
TROUGH WILL EXTEND FROM HUDSON BAY TO THE DESERT SOUTHWEST...WITH
QUASI-ZONAL FLOW ACROSS THE SOUTHERN TIER OF THE U.S. TUESDAY AND
WEDNESDAY...A STRONG U/L DISTURBANCE WILL DIG DOWN THE BACKSIDE OF
THE EAST PACIFIC RIDGE WITH AN U/L LOW CUTTING OFF OVER THE
SOUTHWEST U.S. ESTABLISHING A STRONG OMEGA BLOCK OVER THE EASTERN
PACIFIC. SOUTHERN STREAM FLOW WILL UNDER CUT THE EAST PACIFIC BLOCK
WITH PRIMARY NORTHERN STREAM FLOW INTO THE CONUS DOWN THE BACKSIDE
OF THE RIDGE FROM WESTERN CANADA AND ACROSS THE UPPER MISSISSIPPI
VALLEY AND GREAT LAKES REGION.
AT THE SURFACE...A COLD FRONT WILL PUSH SLOWLY ACROSS THE FORECAST
AREA TUESDAY WITH A SLIGHT CHANCE OF A SHOWER. THE FRONT
WILL STALL OVER SOUTH FLORIDA WEDNESDAY AS THE FRONT BECOMES
PARALLEL TO THE U/L FLOW. SURFACE HIGH PRESSURE WILL BUILD OVER
WEST CENTRAL AND SOUTHWEST FLORIDA BEHIND THE FRONT WITH SLIGHTLY
COOLER TEMPERATURES ADVECTING ACROSS THE REGION THROUGH THURSDAY.
ON FRIDAY...THE U/L LOW OVER THE DESERT SOUTHWEST WILL BEGIN TO OPEN
UP AND EJECT EAST APPROACHING THE SOUTHERN PLAINS LATE IN THE DAY.
SURFACE HIGH PRESSURE WILL MOVE OFF THE MID ATLANTIC COAST WITH LONG
FETCH EAST TO SOUTHEAST BOUNDARY LAYER RETURN FLOW DEVELOPING ACROSS
THE FLORIDA PENINSULA WITH A SIGNIFICANT INCREASE IN BOUNDARY LAYER
MOISTURE AND WARMER TEMPERATURES. PREDOMINATELY DRY CONDITIONS ARE
EXPECTED THROUGH THE EXTENDED PERIOD WITH TEMPERATURES RUNNING ABOVE
CLIMATIC NORMALS.
&&
AVIATION...
CONDITIONS ARE RETURNED TO VFR AT ALL TERMINALS AFTER THE WIDESPREAD
DENSE FOG EARLIER IN THE MORNING. THE REMAINDER OF THE DAY SHOULD
FEATURE THE VFR CONDITIONS UNDER A DEVELOPING SCT CU FIELDS. LIGHT
SE/S WINDS WILL SHIFT SW/W DURING THE MIDDLE AND LATER AFTERNOON
HOURS NEAR THE COAST WITH A WEAK SEABREEZE DEVELOPING. AREAS OF FOG
WILL AGAIN DEVELOP AFTER MIDNIGHT TONIGHT...HOWEVER CONDITIONS DO
NOT APPEAR AS FAVORABLE TO SEE THE EXTENT OF DENSE FOG SEEN THIS
PAST OVERNIGHT. BEST CHANCES TO SEE SIGNIFICANT VIS/CIG RESTRICTION
LOOK TO BE KLAL AND KPGD.
&&
MARINE...
LIGHT SOUTH SOUTHEAST WINDS ON THE BACK SIDE OF HIGH PRESSURE OVER
THE WESTERN ATLANTIC WILL CONTINUE FOR THE NEXT COUPLE OF DAYS OVER
THE COASTAL WATERS. SEA FOG WILL BE POSSIBLE TODAY AND MONDAY WITH A
WARM AND HUMID AIR MASS OVERRIDING THE RELATIVELY COOLER WATERS. A
WEAK FRONTAL BOUNDARY APPROACHES THE AREA ON MONDAY AND TUESDAY
KEEPING THE SOUTHERLY WIND FLOW IN PLACE AND PRODUCING A SLIGHT
CHANCE OF SHOWERS. THE WINDS WILL SHIFT TO THE NORTH NORTHEAST IN
THE WAKE OF THIS FRONT ON TUESDAY...AND WILL REMAIN OUT OF THE
NORTHEAST THROUGH THE WEEK AS HIGH PRESSURE SETTLES INTO THE REGION.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 79 65 78 65 / 0 10 10 30
FMY 81 66 81 66 / 0 0 10 10
GIF 82 64 81 64 / 0 0 10 20
SRQ 77 64 77 65 / 0 0 10 30
BKV 81 60 79 61 / 0 0 10 30
SPG 77 66 76 65 / 0 10 10 30
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
UPDATE/AVIATION...MROCZKA
MARINE...WYNN
LONG TERM...OGLESBY
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
1025 AM EST SUN DEC 28 2014
.DISCUSSION...
...HIGH RISK OF RIP CURRENTS AT EAST CENTRAL FL BEACHES TODAY...
MRNG RAOBS SHOW A NEARLY SATURATED H100-H90 LYR WITH A PRONOUNCED
H90-H70 SUBSIDENCE INVERSION TRAPPING THE MOISTURE NEAR THE SFC.
DENSE FOG (VSBY AOB 1/4SM) LINGERING AT A FEW SITES...BUT LATEST SAT
IMAGES SHOW THE SRN FLANK OF THE FOG/STRATUS DECK HAS RETREATED N OF
SR50. SFC OBS SHOW VSBYS BOUNCING BTWN 1/2SM AND 3SM...INDICATING
THE SFC INVERSION IS BURNING OFF AND ALLOWING THE MOISTURE TO MIX
OUT. WITH PREVAILING VSBYS NOW AOA 1/2SM...FOG NO LONGER MEETS DENSE
CRITERIA...ADVISORY HAS BEEN ALLOWED TO EXPIRE.
LATEST RUC ANALYSIS SHOWS THE AXIS OF AN H100-H70 ANTICYCLONE
EXTENDING FROM THE NRN BAHAMAS TO THE YUCATAN PENINSULA WITH A
STRONG LIFTING H30-H20 JET STREAK EXTENDING FROM THE RIO GRANDE
VALLEY TO THE CANADIAN MARITIMES. NO SIG CHANGE IN THE PATTERN TODAY
AS THE RIDGE AXIS MEANDERS ACRS THE S HALF OF THE PENINSULA...
MAINTAINING A SRLY FLOW ARND 10MPH.
DESPITE A RELATIVELY MOIST H100-H85 LYR UPSTREAM WITH MEAN RH VALUES
AOA 80PCT...AIRMASS HAS LITTLE IN THE WAY OF MID LVL VORTICITY OR
OMEGA LIFT...WHILE THE JET STREAK IS LOCATED TOO FAR TO THE NW TO
PROVIDE ANY SIG UPR LVL DIVERGENCE. FCST WILL REMAIN DRY. DEEP SRLY
FLOW WILL ALLOW MAX TEMPS TO WARM INTO THE L80S AREAWIDE...WHICH
WILL PUT MANY MAX RECORDS AT RISK.
UPDATES TO REMOVE FOG FROM THE FCST...NO OTHER CHANGES NECESSARY.
&&
.AVIATION...THRU 29/12Z
SFC WNDS: THRU 29/03Z...S/SW BTWN 5-8KTS...BCMG S/SE CSTL SITES AFT
28/18Z. AFT 29/03Z...S/SW AOB 3KTS.
VSBYS/WX: THRU 28/17Z...N OF KTIX-KISM AREAS MVFR BR...S OF
KTIX-KISM VFR. BTWN 28/17Z-29/03Z...VFR ALL SITES. AFT 29/03Z...
PREVAILING MVFR BR ALL SITES...N OF KTIX-KISM AREAS LIFR IN FG.
CIGS: THRU 28/17Z...N OF KTIX-KISM AREAS LIFR BTWN FL004-006...S OF
KTIX-KISM AOA FL120. BTWN 28/17Z-29/03Z...VFR ALL SITES. AFT
29/03Z...PREVAILING MVFR BTWN FL010-020 ALL SITES...AREAS LIFR BLO
FL004 N OF KTIX-KISM.
&&
.MARINE...
HI PRES RIDGE AXIS EXTENDING FROM THE W ATLC ACRS S FL TO THE S
CNTRL GOMEX WILL MAINTAIN A LIGHT TO GENTLE S/SW BREEZE ACRS THE LCL
ATLC THRU TONIGHT. SEAS 3-4FT NEARSHORE AND 4-5FT OFFSHORE...ALMOST
ALL OF WHICH WILL BE DUE TO A LONG PD ERLY SWELL. THE LONG PD SWELL
WILL GENERATE A HIGH RIP CURRENT THREAT AT AREA BEACHES THIS AFTN.
NO SIG CHANGES WITH THE MORNING UPDATE.
&&
.CLIMATE...
RECORD HIGHS TODAY... FCST
RECORD HIGH
DAYTONA BEACH 83/1988 81
ORLANDO 85/1916 83
MELBOURNE 87/1981 82
VERO BEACH 84/1981 82
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...BRAGAW
LONG TERM/IMPACT WX...LASCODY
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
652 AM EST SUN DEC 28 2014
.SYNOPSIS...
A COLD FRONT TO OUR WEST WILL SLOWLY MAKE ITS WAY ACROSS THE
AREA TONIGHT AND MONDAY BRINGING THE CHANCE FOR RAIN. DRY WEATHER
AND COOLER TEMPERATURES WILL RETURN FOR MID-WEEK AS HIGH PRESSURE
DOMINATES. ANOTHER COLD FRONT WILL BRING THE THREAT OF RAIN NEXT
WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE UPPER LEVEL FLOW WILL REMAIN HIGHLY AMPLIFIED WITH A RIDGE
CENTERED OVER THE BAHAMAS AND CUBA...AND A POSITIVELY TILTED
TROUGH EXTENDING FROM THE WESTERN GREAT LAKES REGION INTO WEST
TEXAS. AT THE SURFACE...HIGH PRESSURE WAS OVER THE WESTERN
ATLANTIC WITH A COLD FRONT EXTENDING FROM THE CENTRAL APPALACHIANS
SOUTHWESTWARD TO MISSISSIPPI. DEEP SOUTHWEST FLOW AHEAD OF THE
FRONT WILL PUMP MOISTURE INTO OUR AREA TODAY AND TONIGHT.
MODELS KEEP MUCH OF THE RAINFALL ACROSS NORTHERN GEORGIA INTO
NORTHERN SOUTH CAROLINA TODAY. WE KEPT THE HIGHEST POPS ACROSS
THE NORTH AND WEST...AND DRIER FARTHER SOUTH AND EAST. MUCH OF THE
MORNING RAIN WILL LIFT NORTH OF THE MIDLANDS FOR THE AFTERNOON.
MILD TEMPERATURES RANGING FROM THE LOWER 60S NORTH AND WEST...TO
AROUND 70 SOUTH AND EAST ARE FORECAST TODAY.
THE CHANCE FOR RAIN INCREASES AGAIN OVERNIGHT AS THE COLD FRONT
AND A WEAK UPPER LEVEL DISTURBANCE ENTERS THE FORECAST AREA.
RAINFALL AMOUNTS WILL GENERALLY BE LESS THAN ONE HALF OF AN INCH.
SHOULD SEE OVERNIGHT LOWS IN THE 50S UNDER CLOUDY SKIES.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
THE COLD FRONT WILL BE SLOW TO EXIT THE FORECAST AREA AS SEVERAL
WEAK WAVES ARE EXPECTED TO DEVELOP ALONG THE BOUNDARY. THE CHANCE
FOR RAIN CONTINUES MONDAY...THEN BEGIN TO TAPERS OFF MONDAY NIGHT
INTO TUESDAY MORNING AS THE COLD FRONT MOVES OFFSHORE AND DRIER
AIR FILTERS IN FROM THE WEST.
ABOVE NORMAL TEMPERATURES MONDAY WILL DROP BACK INTO THE 50S FOR
TUESDAY. OVERNIGHT LOWS IN THE 40S MONDAY NIGHT WILL COOL INTO
THE 30S TUESDAY NIGHT GIVEN MOSTLY CLEAR SKIES AND LIGHT WINDS.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
STRONG CANADIAN HIGH PRESSURE WILL REMAIN CENTERED OFF TO THE WEST
OF THE FORECAST AREA ON WEDNESDAY...THEN IT WILL GRADUALLY
PUSH EASTWARD INTO THE SOUTHEAST ON THURSDAY...THEN PUSH OFF THE
COAST INTO FRIDAY. DRY WEATHER IS FORECAST INTO THURSDAY NIGHT...
THEN MOISTURE IS EXPECTED TO RETURN THROUGH THE DAY FRIDAY AS A
WARM FRONT LIFTS NORTHWARD FROM THE GULF COAST STATES. MODELS
INCREASE RAIN CHANCES FRIDAY INTO SATURDAY...AND HAVE GENERALLY
GONE WITH CHANCE POPS FOR THAT TIME FRAME. ALTHOUGH TEMPERATURES
WILL BE ON THE COLD SIDE WEDNESDAY INTO FRIDAY...TEMPS WILL
INCREASE FRIDAY INTO SATURDAY...WHICH WILL KEEP READINGS WARM
ENOUGH THAT THE PRECIP WILL BE ALL LIQUID.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
88D SHOWS A BAND OF SHOWERS WITH ISOLATED THUNDERSTORMS STRETCHING
FROM CENTRAL AL NORTHEAST ACROSS NRN GA INTO THE NW HALF OF SC.
CURRENT RADAR TRENDS WILL TAKE THE BULK OF THE PRECIPITATION NW OF
THE TAF SITES...BUT SOME LIGHT RAIN IS STILL POSSIBLE THROUGH THE
MORNING AS AGS/DNL/CAE/CUB ARE ON THE EASTERN FRINGE OF THE
PRECIPITATION SHIELD. THIS AGREES WITH MODELS TAKING BEST ISENTROPIC
LIFT ACROSS THE UPSTATE.
CLOUD BASES HAVE LOWERED TO MVFR AT ALL TAF SITES EXCEPT FOR OGB.
MODEL GUIDANCE SUGGEST THAT CLOUD BASES WILL CONTINUE TO LOWER
ACROSS THE MIDLANDS/CSRA THIS MORNING AND EXPECT ALL TAF SITES TO
BECOME MVFR AND REMAIN SO THROUGH THE REMAINDER OF THE PERIOD.
LATEST HRRR INDICATE THAT LIGHT RAIN ACROSS THE MIDLANDS AND CSRA
WILL MOVE NORTHEAST OF THE TAF SITES BY MID/LATE MORNING. TO MVFR
THIS MORNING AS THE ATMOSPHERE BECOME MORE MOIST. ISENTROPIC LIFT
WILL ONCE AGAIN INCREASE TONIGHT AROUND/AFTER MIDNIGHT AS A COLD
FRONT MOVES CLOSER TO THE REGION FROM THE WEST. EXPECT AN INCREASING
CHANCE FOR SHOWERS AFTER 06Z. HAVE CONTINUED WITH A MENTION OF LIGHT
RAIN/VCSH IN THE TAFS OVERNIGHT WITH LOWERING CEILINGS AND VSBYS.
NEAR CALM WINDS SHOULD BECOME SOUTH TO SOUTHWEST AROUND 5 KNOTS
AFTER SUNRISE AND CONTINUE THROUGH THE DAY. WINDS WILL WEAKEN BY
SUNSET AND BE LIGHT THROUGH THE REMAINDER OF THE FORECAST
EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE TONIGHT THROUGH
EARLY TUESDAY AS THE NEXT FRONTAL SYSTEM MOVES INTO THE AREA AND
STALLS JUST TO THE SOUTH.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...FLASH FLOOD WATCH THROUGH TUESDAY EVENING FOR SCZ030.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
611 AM EST SUN DEC 28 2014
.SYNOPSIS...
HIGH PRESSURE WILL PULL FURTHER OFFSHORE TODAY. A COLD FRONT WILL
SLOWLY MOVE THROUGH THE REGION LATE MONDAY AND MONDAY NIGHT. HIGH
PRESSURE WILL THEN BUILD INTO THE AREA TUESDAY THROUGH THURSDAY...
BEFORE MOVING INTO THE ATLANTIC LATE IN THE WEEK. A COLD FRONT
COULD APPROACH NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRESSURE CENTERED WELL OFFSHORE OF THE NORTH CAROLINA OUTER
BANKS WILL SHIFT FARTHER OUT INTO THE ATLANTIC TODAY AS A COLD
FRONT APPROACHES FROM THE WEST. A VERY WEAK COASTAL TROUGH NOTED
OVER THE GULF STREAM YESTERDAY EVENING HAS DISSIPATED WITH THE
LOW-LEVEL WIND FIELD OVER THE LOCAL MARINE AREA NOW SOUTHWEST
VERSUS NORTHEAST. THE EXPANSIVE UPPER RIDGE THAT IS IN PLACE ALOFT
WILL NUDGE EAST TODAY A POTENT SHORTWAVE OVER THE SOUTHERN
ROCKIES/ 4-CORNERS REGION DIGS INTO NORTHERN MEXICO AND THE
EDWARDS PLATEAU OF TEXAS. THERE LOOKS TO BE ENOUGH RIDING BOTH AT
THE SURFACE AND ALOFT TO KEEP THE PRIMARY MOISTURE CONVEYOR AHEAD
OF THE COLD FRONT TO THE WEST TODAY...THUS KEEPING DRY CONDITIONS
IN PLACE FOR ALL OF SOUTHEAST SOUTH CAROLINA AND SOUTHEAST
GEORGIA. IT WILL BE WARM DAY AS 850 HPA TEMPERATURES RISE TO +12C
TO +14C... ALTHOUGH MID/HIGH LEVEL CLOUDINESS WILL TEMPER THE
WARMTH POTENTIAL SOMEWHAT. IT WILL STILL BE A VERY WARM DAY FOR
LATE DECEMBER WITH HIGHS RISING INTO THE MID 70S AWAY FROM THE
BEACHES. A FEW UPPER 70S WILL BE POSSIBLE FOR AREAS CLOSEST TO THE
ALTAMAHA RIVER AS MORE BREAKS IN THE CLOUD COVER ARE EXPECTED TO
OCCUR THERE. IMMEDIATE BEACH LOCATIONS WILL LIKELY STRUGGLE TO
REACH THE LOWER 60S DUE TO THE PROXIMITY OF CHILLY ATLANTIC SHELF
WATERS IN THE MID 50S AND POSSIBLY SEA FOG.
THERE IS A POTENTIAL FOR SIGNIFICANT SEA FOG DEVELOPMENT OVER THE
COASTAL WATERS TODAY AS WARM/MOIST AIR BEGINS TO FLOW OVER THE
CHILLY SHELF WATERS THAT ARE IN PLACE OFF THE COAST. THE SYNOPTIC
MODELS HAVE BEEN HINTING AT SEA FOG DEVELOPMENT FOR QUITE SOME
TIME...ALTHOUGH ITS ONSET AND EXTENT IS STILL IN QUESTION.
CONDITIONS CERTAINLY LOOK RIPE FOR WIDESPREAD SEA FOG DEVELOPMENT...
SIMILAR TO WHAT HAS BEEN SEEN OVER THE PAST SEVERAL WEEKS DURING
WARM PERIODS. ANY SEA FOG THAT FORMS OFFSHORE COULD CERTAINLY
BEGIN TO MOVE INLAND THIS AFTERNOON AS A SEA BREEZE CIRCULATION
TAKES HOLD ALONG THE COAST. DEPENDING ON HOW STRONG THE THERMALLY
DIRECT CIRCULATION BECOMES...DENSE FOG COULD BE ADVECTED AS FAR
INLAND AS THE INTRACOASTAL WATERWAY...CHARLESTON HARBOR AND
POSSIBLY THE SAVANNAH RIVER...AFFECTING DOWNTOWN CHARLESTON AND
PARTS OF DOWNTOWN SAVANNAH BY LATE AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
TONIGHT...MEAN RIDGING WILL LIKELY GIVE WAY ENOUGH OVERNIGHT THAT
ISOLATED TO PERHAPS LOW-END SCATTERED SHOWERS COULD IMPACT MAINLY
THE CENTRAL AND WESTERN PORTIONS OF THE FORECAST AREA LATE TONIGHT
AS A COLD FRONT AND WEAK FRONTAL WAVE APPROACHES. RAINFALL
AMOUNTS...IF ANY...WILL BE LIGHT AS MODELS STILL DEPICT A WELL-
DEFINED MID-LEVEL CLOUD POCKET HOLDING FIRM. WILL HIGHLIGHT 20-30
PERCENT POPS IN THESE AREAS...ALTHOUGH CONFIDENCE FOR ACTUALLY
SEEING MEASURABLE RAINFALL IS LOW. IT WILL BE ANOTHER WARM NIGHT
WITH LOWS RANGING FROM THE UPPER 50S INLAND TO THE LOWER 60S
COAST.
OUR BIGGEST CONCERN TONIGHT IS FOR THE POTENTIAL FOR A WIDESPREAD
DENSE SEA FOG EVENT UNFOLDING ACROSS THE AREA. AREAS OF SEA FOG
WILL LIKELY BE ONGOING ACROSS THE COASTAL WATERS AND POSSIBLY THE
COASTAL COUNTIES AT SUNSET...WHICH SHOULD SPREAD INLAND UNDERNEATH
THE NOCTURNAL INVERSION AS THE NIGHT PROGRESSES. IN ADDITION...
MODELS SUGGEST A SECONDARY AREA OF SEA FOG AND RADIATION FOG WILL
DEVELOP OVER THE NORTHEAST GULF AND FLORIDA PANHANDLE THIS
EVENING...THEN GRADUALLY SPREAD IN FROM THE SOUTH AND SOUTHWEST
AFTER MIDNIGHT. CONDITIONS CERTAINLY LOOK FAVORABLE FOR WIDESPREAD
FOG TO AFFECT MANY AREAS TONIGHT...BUT FORECASTING THE TIMING AND
EXTENT OF SEA FOG IS ALWAYS A CHALLENGE. CONFIDENCE IN SEA FOG
FORMING IS RATHER HIGH GIVEN EXTENSIVE SEA FOG HAS ALREADY
OCCURRED DURING PREVIOUS WARM SPELLS EXPERIENCED OVER THE PAST FEW
WEEKS...BUT IT REMAINS TO BE SEEN EXACTLY HOW THIS EVENT WILL PLAY
OUT. WILL HIGHLIGHT AREAS OF FOG AND WIDESPREAD FOG ALL AREAS
TONIGHT...GRADUALLY SPREADING INLAND AND FROM THE SOUTH OVERNIGHT.
THE INTRODUCTION OF DENSE AND VISIBILITY ATTRIBUTES MAY EVENTUALLY
BE NEEDED IN THE GRIDDED AND TEXT FORECASTS. A DENSE FOG ADVISORY
MAY VERY WELL BE NEEDED FOR SOME AREAS OVERNIGHT AND THIS
POTENTIAL WILL REMAIN HIGHLIGHTED IN THE HAZARDOUS WEATHER
OUTLOOK.
MONDAY...WEAKENING SHORTWAVE ENERGY WILL MOVE ACROSS THE MID
ATLANTIC AND CAROLINA COASTLINE DURING THE MORNING AND AFTERNOON
TIME FRAME. A COLD FRONT WILL SHIFT INTO THE FORECAST AREA AND
GRADUALLY SLIP OFF THE SOUTHEAST COAST THROUGH THE EVENING AND
OVERNIGHT. ALTHOUGH THE BEST CHANCE OF RAIN DURING THE SHORT TERM
PERIOD APPEARS TO OCCUR WITH FRONTAL PASSAGE MONDAY AFTERNOON...
PREFER TO CAP POPS BELOW THE LIKELY CATEGORY CONSIDERING SOME
UNCERTAINTIES REGARDING COVERAGE. WILL INDICATE RAIN CHANCES
PEAKING IN THE 40 PERCENT RANGE TO ACCOUNT FOR SOME FRONTAL
CONVERGENCE AND MOISTURE ACCESS...WHILE STILL REMAINING
CONSERVATIVE SINCE THE FRONT WILL BE NEARLY PARALLEL TO THE
DAMPENING FLOW ALOFT AND SHORTWAVE ENERGY WILL BE IN A WEAKENING
STATE. COMPRESSIONAL WARMING IN ADVANCE OF THE COLD
FRONT...COMBINED WITH A DOWNSLOPE FLOW COMPONENT...WILL SUPPORT
ANOTHER UNSEASONABLY WARM DAY. EXPECT TEMPERATURES TO PEAK IN THE
UPPER 60S TO LOW 70S...WHILE LOW TEMPERATURES ARE RELATIVELY MILD
IN THE LOW TO MID 50S.
TUESDAY...RAIN WILL STEADILY DIMINISH IN COVERAGE FROM NORTHWEST
TO SOUTHEAST THROUGH THE MORNING HOURS...AS THE COLD FRONT AND AN
ASSOCIATED WAVE OF LOW PRESSURE MOVE FARTHER AWAY FROM THE COAST.
RAIN CHANCES WILL FALL BELOW 15 PERCENT BY EARLY AFTERNOON...WITH
SKY COVER SLOWLY SCATTERING TOWARD THE EVENING HOURS. COLD
ADVECTION AND NORTH FLOW IN THE WAKE OF THE FRONT AND ALONG THE
PERIPHERY OF EXPANSIVE HIGH PRESSURE BUILDING FROM THE WEST WILL
SUPPORT COOLER AND DRIER CONDITIONS. HIGH TEMPERATURES WILL RANGE
FROM THE LOW 60S NORTH TO THE MID 60S SOUTH...WITH NIGHTTIME LOWS
FALLING INTO THE UPPER 30S TO LOWER 40S.
WEDNESDAY...AN IMPRESSIVELY STRONG AND EXPANSIVE SURFACE HIGH WILL
STRETCH ACROSS MUCH OF THE CENTRAL AND EASTERN UNITED STATES BY
MID WEEK. EXPECT RATHER QUIET CONDITIONS TO PREVAIL...WITH
TEMPERATURES A DEGREE OR TWO BELOW SEASONAL NORMALS. HIGH
TEMPERATURES WILL BE IN THE LOW 50S NORTH TO UPPER 50S SOUTH UNDER
MOSTLY CLEAR SKIES.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
THE EXPANSIVE SURFACE HIGH WILL STEADILY SHIFT OVER THE SOUTHERN
UNITED STATES BY THURSDAY...BEFORE SHIFTING INTO THE ATLANTIC
WATERS FRIDAY AND SATURDAY. A STRONG CUT OFF LOW OVER SOUTHERN
CALIFORNIA THURSDAY MORNING WILL WEAKEN WHILE TRACKING ACROSS THE
SOUTHWEST STATES FRIDAY...EVENTUALLY PROVIDING THE NECESSARY
ENERGY TO SPIN UP A SURFACE LOW PRESSURE SYSTEM THAT WILL LIFT
INTO THE OHIO VALLEY SATURDAY. THE TRAILING COLD FRONT FROM THIS
SYSTEM WILL CROSS THE EASTERN UNITED STATES OVER THE WEEKEND. WILL
MAINTAIN DRY WEATHER WEDNESDAY NIGHT THROUGH THURSDAY AS HIGH
PRESSURE REMAINS IN CONTROL...THEN REINTRODUCE RAIN CHANCES FRIDAY
INTO THE WEEKEND TO ACCOUNT FOR THE NEXT FRONTAL SYSTEM. LATEST
MODEL SOLUTIONS SUGGEST BEST RAIN POTENTIAL WILL BE
SATURDAY...WHEN THE COLD FRONT IS CURRENTLY FORECAST TO BE
CROSSING THE REGION. WILL ADVERTISE SEASONAL TEMPERATURES THURSDAY
AND FRIDAY...THEN INDICATE A WARMING TREND FRIDAY NIGHT INTO THE
WEEKEND AHEAD OF THE APPROACHING FRONT.
&&
.AVIATION /11Z SUNDAY THROUGH THURSDAY/...
VFR TODAY ATHOUGH THERE IS A SLIGHT CHANCE FOR A BRIEF PERIOD OF
MVFR CIGS AT BOTH KCHS/KSAV JUST AFTER SUNSET IF THE RAP SOUNDINGS
PROVE CORRECT. SEA FOG IS EXPECTED TO DEVELOP OFF THE COAST LATER
TODAY. SOME OF THIS WILL SPREAD INLAND LATE THIS AFTERNOON WITH
THE SEA BREEZE WITH A BIGGER PUSH EXPECTED OVERNIGHT. AT THIS
TIME...THE BEST CHANCES FOR SIGNIFICANT IMPACTS LOOKS TO BE AT
KCHS...ALTHOUGH PROBABILITIES ARE HIGH AT KSAV AS WELL. WILL TAKE
A SOMEWHAT CONSERATIVE APPROACH WITH THE 12Z TAFS SINCE THE TIMING
AND EXTENT IS STILL A BIT UNCERTAIN. WILL SHOW MVFR VSBYS/CIGS THIS
EVENING...DROPPING TO LIFR AT KCHS BY 06Z WITH HIGH-END IFR AT
KSAV. BOTH SITES COULD VERY WELL DROP BELOW AIRFIELD MINIMUMS
AFTER 06Z...BUT WILL NOT INTRODUCE THOSE CONDITIONS JUST YET.
EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS LIKELY LATE
MONDAY INTO MONDAY NIGHT AS A COLD FRONT MOVES ACROSS THE REGION.
&&
.MARINE...
TODAY...VARIABLE WINDS WILL GRADUALLY BECOME SOUTH TO SOUTHWEST
TODAY AS A COLD FRONT APPROACHES FROM THE WEST. WINDS WILL REMAIN
LESS THAN 10 KT THROUGH THE DAY ONCE THE WIND PICKS UP. THERE WILL
BE A RISK FOR SEA FOG DEVELOPING TODAY AS WARM/MOIST AIR FLOWS
OVER THE CHILLY SHELF WATERS. THE ONSET AND EXTENT OF THE SEA FOG
REMAINS IN QUESTIONS...ALTHOUGH MODELS HAVE BEEN HINTING AT THIS
FOR SEVERAL RUNS NOW...ESPECIALLY OVER THE GEORGIA AND BEAUFORT
COUNTY WATERS WHERE AIR PARCEL RESIDENCE TIMES WILL BE THE
LONGEST. WILL LIMIT CONDITIONS TO AREAS OF FOG FOR NOW...ALTHOUGH
THE FOG MAY VERY WELL BECOME WIDESPREAD AND DENSE. A MARINE DENSE
FOG ADVISORY MAY EVENTUALLY BE NEEDED AND WILL BE ADDRESSED IN THE
HAZARDOUS WEATHER OUTLOOK. SEAS WILL AVERAGE 2 FT NEARSHORE AND
3-4 FT OFFSHORE...MAINLY IN LONG PERIOD EAST SWELLS WITH PERIODS
OF 15-18 SECONDS.
TONIGHT...CONDITIONS LOOK TO FAVOR WIDESPREAD DENSE SEA FOG ACROSS
THE NEARSHORE WATERS AS SOUTHWEST WINDS DOMINATE WITH SPEEDS LESS
THAN 10 KT. IT IS STILL UNCLEAR EXACTLY HOW WIDESPREAD AND DENSE
THE SEA FOG WILL BECOME...BUT CONFIDENCE IS INCREASING THAT A
NASTY DENSE SEA FOG EVENT WILL OCCUR. WILL GO AHEAD AND INTRODUCE
WIDESPREAD FOG IN THE GRIDDED AND TEXT FORECASTS...BUT NO
INTRODUCE DENSE WORDING JUST YET. SEAS WILL AVERAGE 2-3 FT
NEARSHORE WATERS AND 3-4 FT OFFSHORE WATERS...MAINLY IN LONG
PERIOD EAST SWELL.
MONDAY...A COLD FRONT WILL SLIP INTO THE COASTAL WATERS DURING
THE EVENING/OVERNIGHT HOURS...ALLOWING SOUTHWEST FLOW EARLY IN THE
DAY TO VEER NORTH OVER THE SOUTH CAROLINA WATERS AND NORTHWEST
ACROSS GEORGIA MARINE ZONES. SEA FOG WILL PERSIST ACROSS THE
NEARSHORE WATERS DURING THIS TIME...MOST LIKELY JUST OUTSIDE OF
CHARLESTON AND SAVANNAH HARBORS. HOWEVER...IF WINDS BACK MORE TO
THE SOUTH DURING THE DAYTIME PERIOD...FOG COULD IMPACT ONE OR BOTH
OF THESE PORTS.
TUESDAY THROUGH THURSDAY...AN IMPRESSIVE AREA OF HIGH PRESSURE
WILL BUILD ACROSS THE CENTRAL AND EASTERN UNITED STATES EARLY IN
THE WEEK...EVENTUALLY SETTLING OVER THE SOUTHEAST COAST BY
THURSDAY. THE PRESSURE GRADIENT WILL TIGHTEN ON THE PERIPHERY OF
THE BUILDING SURFACE HIGH...AND CONSIDERING SOME COLD ADVECTION IN
THE WAKE OF THE DEPARTING COLD FRONT...MARGINAL SMALL CRAFT ADVISORY
CONDITIONS ARE POSSIBLE FOR PORTIONS OF THE WATERS TUESDAY INTO
EARLY WEDNESDAY. AS THE CENTER OF THE HIGH SHIFTS TOWARD THE
SOUTHEAST STATES THURSDAY...THE PRESSURE GRADIENT WILL WEAKEN
SUFFICIENTLY TO ALLOW WINDS/SEAS TO SUBSIDE.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
ST
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
429 AM EST SUN DEC 28 2014
.SYNOPSIS...
A COLD FRONT TO OUR WEST WILL SLOWLY MAKE ITS WAY ACROSS THE
AREA TONIGHT AND MONDAY BRINGING THE CHANCE FOR RAIN. DRY WEATHER
AND COOLER TEMPERATURES WILL RETURN FOR MID-WEEK AS HIGH PRESSURE
DOMINATES ANOTHER COLD FRONT WILL BRING THE THREAT OF RAIN NEXT
WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE UPPER LEVEL FLOW WILL REMAIN HIGHLY AMPLIFIED WITH A RIDGE
CENTERED OVER THE BAHAMAS AND CUBA...AND A POSITIVELY TILTED
TROUGH EXTENDING FROM THE WESTERN GREAT LAKES REGION INTO WEST
TEXAS. AT THE SURFACE...HIGH PRESSURE WAS OVER THE WESTERN
ATLANTIC WITH A COLD FRONT EXTENDING FROM THE CENTRAL APPALACHIANS
SOUTHWESTWARD TO MISSISSIPPI. DEEP SOUTHWEST FLOW AHEAD OF THE
FRONT WILL PUMP MOISTURE INTO OUR AREA TODAY AND TONIGHT.
MODELS KEEP MUCH OF THE RAINFALL ACROSS NORTHERN GEORGIA INTO THE
UPSTATE OF SOUTH CAROLINA TODAY. WE KEPT THE HIGHEST POPS ACROSS
THE WEST...AND DRIER ACROSS THE EAST. MILD TEMPERATURES RANGING
FROM THE LOWER 60S NORTH AND WEST...TO AROUND 70 SOUTH AND EAST
ARE FORECAST TODAY.
THE CHANCE FOR RAIN INCREASES OVERNIGHT AS THE COLD FRONT AND A
WEAK UPPER LEVEL DISTURBANCE ENTERS THE FORECAST AREA. RAINFALL
AMOUNTS WILL GENERALLY BE LESS THAN ONE QUARTER OF AN INCH. SHOULD
SEE OVERNIGHT LOWS IN THE 50S UNDER CLOUDY SKIES.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
THE COLD FRONT WILL BE SLOW TO EXIT THE FORECAST AREA AS SEVERAL
WEAK WAVES ARE EXPECTED TO DEVELOP ALONG THE BOUNDARY. THE CHANCE
FOR RAIN CONTINUES MONDAY...THEN BEGIN TAPERS TO AN END MONDAY
NIGHT INTO TUESDAY MORNING AS THE COLD FRONT MOVES OFFSHORE AND
DRIER AIR FILTERS IN FROM THE WEST.
ABOVE NORMAL TEMPERATURES MONDAY WILL DROP BACK INTO THE 50S FOR
TUESDAY. OVERNIGHT LOWS WILL BE IN THE 40 MONDAY NIGHT WILL COOL
INTO THE 30S TUESDAY NIGHT GIVEN MOSTLY CLEAR SKIES AND LIGHT
WINDS.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
STRONG CANADIAN HIGH PRESSURE WILL REMAIN CENTERED OFF TO THE WEST
OF THE FORECAST AREA ON WEDNESDAY...THEN IT WILL GRADUALLY
PUSH EASTWARD INTO THE SOUTHEAST ON THURSDAY...THEN PUSH OFF THE
COAST INTO FRIDAY. DRY WEATHER IS FORECAST INTO THURSDAY NIGHT...
THEN MOISTURE IS EXPECTED TO RETURN THROUGH THE DAY FRIDAY AS A
WARM FRONT LIFTS NORTHWARD FROM THE GULF COAST STATES. MODELS
INCREASE RAIN CHANCES FRIDAY INTO SATURDAY...AND HAVE GENERALLY
GONE WITH CHANCE POPS FOR THAT TIME FRAME. ALTHOUGH TEMPERATURES
WILL BE ON THE COLD SIDE WEDNESDAY INTO FRIDAY...TEMPS WILL
INCREASE FRIDAY INTO SATURDAY...WHICH WILL KEEP READINGS WARM
ENOUGH THAT THE PRECIP WILL BE ALL LIQUID.
&&
.AVIATION /09Z SUNDAY THROUGH FRIDAY/...
88D SHOWS A BAND OF SHOWERS WITH ISOLATED THUNDERSTORMS STRETCHING
FROM CENTRAL AL NORTHEAST ACROSS NRN GA INTO THE NW HALF OF SC.
CURRENT RADAR TRENDS WILL TAKE THE BULK OF THE PRECIPITATION NW OF
THE TAF SITES...BUT SOME LIGHT RAIN IS STILL POSSIBLE THROUGH THE
MORNING. THIS IS AGREES WITH MODELS TAKING BEST ISENTROPIC LIFT
ACROSS THE UPSTATE.
CLOUD BASES HAVE LOWERED TO MVFR AT ALL TAF SITES EXCEPT FOR OGB.
MODEL GUIDANCE SUGGEST THAT CLOUD BASES WILL CONTINUE TO LOWER
ACROSS THE MIDLANDS/CSRA THIS MORNING AND EXPECT ALL TAF SITES TO
BECOME MVFR. LATEST HRRR INDICATE THAT LIGHT RAIN ACROSS THE
MIDLANDS AND CSRA WILL MOVE NORTHEAST OF THE TAF SITES BY MID/LATE
MORNING. TO MVFR THIS MORNING AS THE ATMOSPHERE BECOME MORE MOIST.
ISENTROPIC LIFT WILL ONCE AGAIN INCREASE TONIGHT AROUND/AFTER
MIDNIGHT AS A COLD FRONT MOVES CLOSER TO THE REGION FROM THE WEST.
EXPECT AN INCREASING CHANCE FOR SHOWERS AFTER 06Z.
NEAR CALM WINDS SHOULD BECOME SOUTH TO SOUTHWEST AROUND 5 KNOTS
AFTER SUNRISE AND CONTINUE THROUGH THE DAY.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE TONIGHT THROUGH
EARLY TUESDAY AS THE NEXT FRONTAL SYSTEM MOVES INTO THE AREA AND
STALLS JUST TO THE SOUTH.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...FLASH FLOOD WATCH THROUGH TUESDAY EVENING FOR SCZ030.
GA...NONE.
&&
$$
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
909 PM CST Mon Dec 29 2014
.UPDATE...
ISSUED AT 900 PM CST MON DEC 29 2014
The lift being generated in the post frontal airmass has been very
weak, based on radar returns and local observations. Have only
seen isolated reports of flurries so far. A clearing line just
north of the band of clouds/flurries is progressing southward,
which would spell an end to the very narrow channel of
lift/clouds/flurries. Have updated the sky grids to account for
some clearing later tonight at least across the northern counties.
Less cloud cover would mean colder lows that we currently have, a
bit more toward the colder guidance numbers. Have trimmed a few
degrees from lows NW of a line from SPI to BMI. Will keep a
mention of flurries in tonight`s forecast following the trek of the
band of clouds to the SE. No other significant changes needed this
evening. Tomorrow looks like a colder but mostly sunny day. Updated
info will be available shortly.
&&
.SHORT TERM...(Tonight)
ISSUED AT 315 PM CST MON DEC 29 2014
The 18Z surface analysis indicated the leading edge of the Arctic
airmass, ahead of an intense high pressure center in the Canadian
Rockies, was sinking just south of I-80. Clouds associated with cold
air undercutting were along the I-74 corridor at 20z/2 pm CST. This
area of cloudiness, along with low clouds in southern Iowa/northern
Missouri will overspread central and eventually southeast Illinois
this evening.
There should be enough weak forcing for snow flurries, particularly
in central Illinois this evening, and the rest of the forecast area
late tonight as the short range models point to weak lift just
behind the strongest low level cold advection. The HRRR model is
trying to produce some measurable snow from Bloomington to near
Taylorville between 6 pm and Midnight. At this point, it is the only
model, doing this and has most likely latched on to the area of
light snow around Pontiac. Will keep an eye on this, but for now
will stick to the mention of flurries.
The numerical guidance appears to be on the colder side due to less
cloud cover and stronger cold advection. Thus, will be going with
lows roughly 5 degrees warmer than guidance in central IL and 2-3
degrees warmer in southeast IL due to forecast cloud cover.
&&
.LONG TERM...(Tuesday through Monday)
ISSUED AT 315 PM CST MON DEC 29 2014
The narrow band of flurries will continue into Tuesday morning, but
should dissipate by afternoon. Behind this area, and strong 1050mb
high pressure area will drop into the region. This high will bring
dry weather to the area through Thur night, as well as well below
normal temps through the period. With the center of the high
dropping into the plains Tue night, the coldest temps are expected
to be Tue night through Wed. Northwesterly winds Tue night will
still be around 10mph, so there could be enough mixing to prevent
the bottom from dropping out on the temps. However, single digits
are still expected over half of the CWA, and combined with the wind
speeds, below zero wind chills are probably Tue night/Wed morning.
Beyond this, the high pressure will slide further south into the
southern plains by Thursday night. Temps may warm slightly, but only
to back around normal.
The return of slightly warmer temps and moisture will not occur
until the high pressure area move into the southeastern US Thur
night and Fri. However, along with this will come the chance of pcpn
to the area for the end of the week and the weekend. The questions
still remain as to the timing of the pcpn return, how warm it will
get, and what p-type will occur. Both the GFS and ECMWF continue to
not agree on the overall solution with this system. However, there
is some agreement as to how the upper level will evolve into
Saturday. The upper level low pressure area will weaken and get
lifted out into the flow over the weekend. ECMWF is much quicker
with this than the GFS. Models also agree that the pcpn will not
really begin until Fri night/Sat morning. However, there still
remains a chance of pcpn Friday in the southeast, so will keep
chance pops there, though would not be surprised to see this change
later. Beyond this, models do not agree with location of pcpn and
sfc low pressure area. With the ECMWF being quicker with the upper
level system, it keeps the low further south and therefore has very
little pcpn in our area...and only in the extreme southeast. The GFS
is further north with the low, but has shifted it east since
yesterday`s model runs. However, it keeps pcpn over the area through
the weekend, just not as much as before; and with the low east,
temps may not get as warm, thereby effecting the p-type through the
weekend. Will still be keeping the p-type simple and just going with
snow, becoming rain or snow, then snow at night and rain and/or snow
again during the daytime. The chance of pcpn will continue into Sat
night. Sunday and Monday will be dry for now as the system should be
well east of the area.
Temps in the extended will warm, with the warmest temps being on
Saturday and then cooling back off by Monday as another shot of
colder air slides into the area.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
ISSUED AT 543 PM CST MON DEC 29 2014
The arctic front will continue to slide south and east tonight, as
it dissipates. Flurries will be the primary precipitation, and
will develop behind the front in the region of lift. The RAP and
HRRR are both indicating the area of light snow that lowered visibility
to 3 miles will drift south through Bloomington and eventually
just east of Lincoln toward Taylorville. It is projected to weaken
as it shifts south, but Bloomington may see visibility drop to
MVFR levels in light snow for a couple of hours. The prevailing
cloud cover will lower to MVFR at all TAF sites this evening as
the arctic front progresses southeast. The flurries should
dissipate late tonight and MVFR clouds will break up starting
around 16z at PIA and eventually clearing at DEC around 20z.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Shimon
SHORT TERM...Miller
LONG TERM...Auten
AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
902 PM CST MON DEC 29 2014
.SHORT TERM...
323 PM CST
REMAINDER OF THIS AFTERNOON AND TONIGHT...
LAKE EFFECT SNOW HAS LARGELY BEEN A NON-EVENT THIS AFTERNOON...
MAINLY DUE TO VERY DRY LOW LEVEL AIR IN PLACE OVER NERN
IL/NWRN...WITH DEWPOINTS IN THE UPPER TEENS IN SPITE OF THE NELY
FETCH OFF LAKE LAKE MICHIGAN WHERE WATER TEMPERATURES ARE STILL IN
THE MIDDLE TO UPPER 30S. THE MAIN IMPACT OF THE LAKE HAS BEEN A
BKN-OVC STRATOCU DECK MOVING OFF OF THE LAKE. HOWEVER...THERE HAS
BEEN SOME SCT LIGHT SNOW WITH THE COLD FRONT/LEADING EDGE OF THE
ARCTIC AIRMASS BUILDING ACROSS THE MISSISSIPPI VALLEY AND INTO THE
OHIO VALLEY. WHILE DEEP LAYER MOISTURE HAS BEEN MEAGER...THERE IS
JUST ENOUGH FORCING TO SQUEEZE OUT SOME ISOLD AREAS OF LIGHT
SNOW...MAINLY OVER PORTIONS OF THE AREA SOUTH OF I-80. FOR THE
OVERNIGHT HOURS...AS THE HIGH CONTINUES TO SPREAD SOUTH AND EAST
AND THE CENTER OF THE HIGH BUILDS INTO THE NRN PLAINS/NRN
ROCKIES...LOW LEVEL FLOW SHOULD GRADUALLY BACK THROUGH NLY TO
WNWLY. THE LONGER LAKE FETCH WHEN WINDS BECOME NLY COULD STILL
HELP BRING SOME LAKE EFFECT SNOW SHOWERS TO NWRN INDIANA...BUT
HAVE BACKED OFF ON QPF/SNOW AMOUNTS...WHILE MAINTAINING THE LIKELY
POPS...WITH THE IDEA OF A HIGH POP-LOW QPF SCENARIO. SO...STILL
THINK THERE COULD BE SOME ACCUMULATING LAKE EFFECT SNOW OVER
PORTIONS OF NWRN INDIANA NEAR THE LAKE...BUT AMOUNTS WILL LIKELY
BE LIGHT. AS THE ARCTIC AIRMASS CONTINUES TO SPREAD SOUTH AND
EAST...EXPECT LOWS TONIGHT TO DROP TO NEAR 10F OVER THE ROCKFORD
AREA...WHILE LOCATIONS EAST OF THE I-55 CORRIDOR SHOULD BE IN THE
UPPER TEENS TO LOWER 20S.
KREIN
&&
.LONG TERM...
323 PM CST
TUESDAY THROUGH MONDAY...
WHILE A COOLING TREND INITIATED BEGAN SUNDAY FOLLOWING THE PASSAGE
OF A COLD FRONT LATE SATURDAY...THE MORE SIGNIFICANT COOLING TREND
IS NOW UNDERWAY AS THE TRUE ARCTIC AIRMASS SPREADS ACROSS THE
REGION. AS OF 3PM CST MONDAY AFTERNOON...TEMPERATURES IN THE
NORTHERN PLAINS RANGED FROM THE SINGLE DIGITS ABOVE 0F TO THE SINGLE
DIGITS BELOW ZERO WITH DEWPOINTS OF -10 TO -15F. THE COLD AIR IS
STILL EXPECTED TO SPREAD ACROSS THE LOCAL AREA...BUT THE COLDEST AIR
SHOULD REMAIN TO THE WEST...OVER THE PLAINS AS THE CENTER OF THE
HIGH DROPS FROM THE NORTHERN ROCKIES TONIGHT TO THE LOWER
MISSISSIPPI VALLEY BY THURSDAY MORNING. CONDITIONS ACROSS THE AREA
SHOULD GENERALLY BE DRY THROUGH THURSDAY...WITH BELOW NORMAL
TEMPERATURES AND AMPLE SUNSHINE AS THE SFC HIGH PRESSURE BUILDS
ACROSS THE REGION. STILL ANTICIPATE THAT THE LOWEST TEMPERATURES
SHOULD BE TUESDAY NIGHT INTO WEDNESDAY MORNING AS THE SFC RIDGE AXIS
BUILDS ACROSS THE AREA. WILL CARRY MIN TEMPS FOR WEDNESDAY MORNING
IN THE SINGLE DIGITS FOR THE ENTIRE CWA...RANGING FROM ARND 3F OVER
THE ROCKFORD AREA TO 8-9F EAST OF THE I-57 CORRIDOR. THERE IS SOME
CONCERN THAT THE TEMP FORECAST MAY BE A BIT TOO LOW...CONSIDERING
WINDS SHOULD REMAIN 5-10 MPH OVERNIGHT AND THERE IS NO SNOW COVER.
HOWEVER...EVEN THOUGH THE AIRMASS WILL BE VERY DRY AND SKIES SHOULD
BE MOSTLY CLEAR...EXPECT THAT THE LOWER TEMPERATURES WILL BE MORE
DRIVEN BY ADVECTION OF COLDER AIR FROM THE CENTRAL PLAINS...WITH THE
CENTER OF A 1050MB HIGH WILL BE CENTERED ALONG THE KANSAS COLORADO
BORDER...WITH A RIDGE AXIS EXTENDING TO THE EAST ACROSS CNTRL
ILLINOIS AND INTO THE UPPER OHIO VALLEY. WITH A DIGGING TROUGH
DROPPING THROUGH SCNTRL CANADA...A MODEST WLY GRADIENT WILL BE IN
PLACE...KEEPING WINDS FROM BECMG CALM. SO...EVEN THOUGH THERE IS NO
SNOW COVER OR CALM WINDS TO ALLOW FOR STRONG RADIATIVE COOLING TO
CAUSE THE TEMPERATURES TO DROP INTO THE SINGLE DIGITS...FEEL THAT
THERE WILL BE ENOUGH ADVECTION OF COLD AIR FROM THE CNTRL PLAINS TO
BRING THE LOW TEMPERATURES. THE MAIN IMPACT OF THIS COLD AIR AND
RELATIVELY BREEZY CONDITIONS WILL BE FOR WIND CHILL READINGS TO DROP
TO -5 TO -13 ACROSS THE CWA...WHICH WOULD THE COLDEST SINCE LATE
NOVEMBER.
THE OTHER FORECAST CONCERN FOR THE EXTENDED FORECAST PERIOD WILL BE
ASSOCIATED WITH A CLOSED LOW EXPECTED TO DROP INTO THE DESERT
SOUTHWEST WEDNESDAY AND WEDNESDAY NIGHT AS A STRONG PACIFIC
SHORTWAVE DROPS DOWN THE WEST COAST. THE MODELS HAVE BEEN VERY
CONSISTENT ON THE DEVELOPMENT OF THIS FEATURE...BUT THERE IS STILL A
VARIETY OF SOLUTIONS FROM THE VARIOUS MODELS IN THE TIMING OF
EJECTING THE SYSTEM OUT OF THE SRN ROCKIES AND TRACKING ACROSS THE
SOUTHERN PLAINS AND THEN LIFTING INTO THE OHIO VALLEY. THE GFS/GEM
REMAIN ON THE FASTER END OF THE FORECAST ENVELOPE WHILE THE ECMWF IS
THE CONSISTENTLY SLOWER SOLUTION. WHILE THE SLOWER SOLUTION IS
STILL FAVORED...CONFIDENCE IS STILL LOW THAT THE EVENTUAL
PROGRESSION OF THE SYSTEM COULD STILL BE SLOWER THAN WHAT THE ECMWF
CONTINUES TO INDICATE. SO...WILL MAINTAIN THE IDEA OF A SLOWER
SOLUTION. THE MAIN TREND FOR THE SENSIBLE WEATHER FEATURES SHOULD
BE A WARMING TREND WITH MAX TEMPS REBOUNDING INTO THE 30S FOR FRIDAY
AND SATURDAY AS UPPER HEIGHTS RISE IN ADVANCE OF THE UPPER LOW
EJECTING OUT OF THE DESERT SOUTHWEST. THERE IS DECENT CONFIDENCE IN
THIS GENERAL TREND. THERE IS ALSO DECENT CONFIDENCE IN THE IDEA OF
INCREASING POPS INTO THE WEEKEND...WHICH IS SLOW THAN PREVIOUSLY
FORECAST AND IN LINE WITH A SLOWER PROGRESSION OF THE SYSTEM.
HOWEVER THERE IS RELATIVELY LOW CONFIDENCE IN TIMING AND AMOUNT OF
PCPN AS THERE IS STILL THE CHANCE FOR SOME PHASING OF THE SRN STREAM
SYSTEM WITH NRN STREAM SHORT WAVE ENERGY DROPPING OUT OF THE NRN
PLAINS AND ACROSS THE GREAT LAKES. SO...WILL LIMIT POPS TO CHANCE
LEVELS FOR NOW WITH THE TREND TO DELAY THE ONSET OF ANY PCPN INTO
LATER IN THE FORECAST PERIOD.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 03Z...
* NORTH WINDS BECOMING NORTH-NORTHWEST TONIGHT.
//DISCUSSION...UPDATED 00Z...
MODIFIED ARCTIC HIGH PRESSURE IS BUILDING INTO THE UPPER PLAINS
RESULTING IN NORTH-NORTHEAST WINDS OVER THE TAF SITES EARLY THIS
EVE BECOMING MORE NORTH-NORTHWEST BY LATE EVE. THE FLOW OFF THE
LAKE FOR ORD AND MDW SHOULD KEEP SPEEDS FLUCTUATING SOME BETWEEN
7-11 KT BASED ON TRENDS OF OBSERVATIONS AND HIGH-RESOLUTION MODEL
DATA. PATCHY CIGS BELOW 4000 FT WILL CONTINUE THIS EVE WITH MID-
CLOUD ABOVE THAT. AS DRIER AIR WORKS IN LATER TONIGHT ALL OF THIS
SHOULD BE SHUNTED SOUTH WITH THE EXCEPTION OF GYY RECEIVING LAKE-
EFFECT INSTABILITY AND CLOUDS. SOME LIGHT LAKE-EFFECT SNOW IS
POSSIBLE INTO GYY AS WELL BUT IS NOT EXPECTED TO ACCUMULATE.
TUESDAY SHOULD SEE MAINLY ONLY HIGH CLOUDS WITH NORTHWEST WINDS
AROUND 10-12 KT AS THE HIGH PRESSURE SETTLES SOUTH INTO THE
CENTRAL PLAINS.
//ORD AND MDW CONFIDENCE...UPDATED 03Z...
* MEDIUM-HIGH IN WINDS.
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
WEDNESDAY...VFR. STIFF SOUTHWEST WINDS.
THURSDAY-FRIDAY...VFR. WEST-SOUTHWEST WINDS.
SATURDAY-SUNDAY...CHANCE OF SNOW AND IFR.
MTF
&&
.MARINE...
304 PM CST
NORTH TO NORTHWEST WINDS PERSIST ACROSS THE LAKE TONIGHT...THEN
GRADUALLY BACK SOUTHWEST BY WEDNESDAY AND INCREASE TO GALES BY
WEDNESDAY AFTERNOON OR EVENING. IT IS NOT CERTAIN HOW EFFECTIVELY
THESE SOMEWHAT MILDER SOUTHWEST WINDS WILL SUPPORT STRONG GALES
OVER THE COLD WATER...BUT GALES DO APPEAR LIKELY. UNTIL WINDS TURN
AWAY FROM NORTH AND NORTHWEST...CONDITIONS WILL BE FAVORABLE FOR
SMALL CRAFT HEADLINES FOR THE FIRST HALF OF THE WEEK...AND
ESPECIALLY IN THE INDIANA NEARSHORE WATERS.
LENNING
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
543 PM CST Mon Dec 29 2014
.SHORT TERM...(Tonight)
ISSUED AT 315 PM CST MON DEC 29 2014
The 18Z surface analysis indicated the leading edge of the Arctic
airmass, ahead of an intense high pressure center in the Canadian
Rockies, was sinking just south of I-80. Clouds associated with cold
air undercutting were along the I-74 corridor at 20z/2 pm CST. This
area of cloudiness, along with low clouds in southern Iowa/northern
Missouri will overspread central and eventually southeast Illinois
this evening.
There should be enough weak forcing for snow flurries, particularly
in central Illinois this evening, and the rest of the forecast area
late tonight as the short range models point to weak lift just
behind the strongest low level cold advection. The HRRR model is
trying to produce some measurable snow from Bloomington to near
Taylorville between 6 pm and Midnight. At this point, it is the only
model, doing this and has most likely latched on to the area of
light snow around Pontiac. Will keep an eye on this, but for now
will stick to the mention of flurries.
The numerical guidance appears to be on the colder side due to less
cloud cover and stronger cold advection. Thus, will be going with
lows roughly 5 degrees warmer than guidance in central IL and 2-3
degrees warmer in southeast IL due to forecast cloud cover.
&&
.LONG TERM...(Tuesday through Monday)
ISSUED AT 315 PM CST MON DEC 29 2014
The narrow band of flurries will continue into Tuesday morning, but
should dissipate by afternoon. Behind this area, and strong 1050mb
high pressure area will drop into the region. This high will bring
dry weather to the area through Thur night, as well as well below
normal temps through the period. With the center of the high
dropping into the plains Tue night, the coldest temps are expected
to be Tue night through Wed. Northwesterly winds Tue night will
still be around 10mph, so there could be enough mixing to prevent
the bottom from dropping out on the temps. However, single digits
are still expected over half of the CWA, and combined with the wind
speeds, below zero wind chills are probably Tue night/Wed morning.
Beyond this, the high pressure will slide further south into the
southern plains by Thursday night. Temps may warm slightly, but only
to back around normal.
The return of slightly warmer temps and moisture will not occur
until the high pressure area move into the southeastern US Thur
night and Fri. However, along with this will come the chance of pcpn
to the area for the end of the week and the weekend. The questions
still remain as to the timing of the pcpn return, how warm it will
get, and what p-type will occur. Both the GFS and ECMWF continue to
not agree on the overall solution with this system. However, there
is some agreement as to how the upper level will evolve into
Saturday. The upper level low pressure area will weaken and get
lifted out into the flow over the weekend. ECMWF is much quicker
with this than the GFS. Models also agree that the pcpn will not
really begin until Fri night/Sat morning. However, there still
remains a chance of pcpn Friday in the southeast, so will keep
chance pops there, though would not be surprised to see this change
later. Beyond this, models do not agree with location of pcpn and
sfc low pressure area. With the ECMWF being quicker with the upper
level system, it keeps the low further south and therefore has very
little pcpn in our area...and only in the extreme southeast. The GFS
is further north with the low, but has shifted it east since
yesterday`s model runs. However, it keeps pcpn over the area through
the weekend, just not as much as before; and with the low east,
temps may not get as warm, thereby effecting the p-type through the
weekend. Will still be keeping the p-type simple and just going with
snow, becoming rain or snow, then snow at night and rain and/or snow
again during the daytime. The chance of pcpn will continue into Sat
night. Sunday and Monday will be dry for now as the system should be
well east of the area.
Temps in the extended will warm, with the warmest temps being on
Saturday and then cooling back off by Monday as another shot of
colder air slides into the area.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
ISSUED AT 543 PM CST MON DEC 29 2014
The arctic front will continue to slide south and east tonight, as
it dissipates. Flurries will be the primary precipitation, and
will develop behind the front in the region of lift. The RAP and
HRRR are both indicating the area of light snow that lowered visibility
to 3 miles will drift south through Bloomington and eventually
just east of Lincoln toward Taylorville. It is projected to weaken
as it shifts south, but Bloomington may see visibility drop to
MVFR levels in light snow for a couple of hours. The prevailing
cloud cover will lower to MVFR at all TAF sites this evening as
the arctic front progresses southeast. The flurries should
dissipate late tonight and MVFR clouds will break up starting
around 16z at PIA and eventually clearing at DEC around 20z.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Miller
LONG TERM...Auten
AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1131 AM CST SUN DEC 28 2014
.SHORT TERM...
236 AM CST
THROUGH MONDAY...
HIGH PRESSURE NOSING IN FROM THE WEST RESULTING IN GRADUAL CLEARING
FROM WEST TO EAST EARLY THIS MORNING WITH THE BACK EDGE ALREADY
THOROUGH ROCKFORD. ONCE THE LOW CLOUDS CLEAR EXPECT SOME PASSING HIGH
CLOUDS THIS MORNING EMANATING FROM A MODEST UPPER LOW IN
TEXAS...OTHERWISE IT WILL BE A SEASONAL MOSTLY SUNNY DAY WITH
HIGHS TOPPING OUT IN THE LOW 30S OR SO. WE`LL HOLD A WEST WIND
WHICH WILL MAKE IT FEEL A LITTLE COOLER...THOUGH TODAY LOOKS TO BE
THE WARMEST FOR THE REST OF 2014. ARCTIC HIGH PRESSURE CONTINUES
TO SINK INTO THE CENTER OF THE COUNTRY TONIGHT. LOCALLY...OUR
WINDS TURN NORTHERLY ALLOWING SOME OF THIS CONTINUE MOVING IN.
ZONAL FLOW ALOFT WILL KEEP SOME HIGHER CLOUDS PUSHING INTO THE
REGION PREVENTING A REAL COLD NIGHT...BUT STILL THE COLDEST WE/VE
SEEN IN A WHILE WITH LOWS INTO THE 20S.
BY MONDAY MORNING...A BACKDOOR FRONT MOVING DOWN THE LAKE WILL
CONTINUE THE STREAM OF COLDER AIR. ADDITIONALLY LAKE EFFECT CLOUDS
WILL MOVE INTO NORTHWEST INDIANA AND PORTIONS OF NORTHEAST ILLINOIS.
WITH THE CONTINUED COLD ADVECTION AND MIX OF LOW AND MID
CLOUD...TEMPS WILL STRUGGLE TO GET TO FREEZING IN MANY SPOTS. NAM IS
STILL HINTING AT SOME LAKE EFFECT FLURRIES OR LIGHT SNOW SHOWERS THOUGH
LAKE EFFECT PARAMETERS DURING THE DAY ARE NOT SUPER IMPRESSIVE.
KMD
&&
.LONG TERM...
236 AM CST
MONDAY NIGHT THROUGH SATURDAY...
MONDAY NIGHT...A MORE SIGNIFICANT SURGE OF COLD AIR COMES STREAMING IN.
THIS WILL ENHANCE LAKE EFFECT PARAMETERS...ESPECIALLY IN NORTHWEST
INDIANA AND PORTIONS OF SOUTHERN COOK COUNTY. EQUILIBRIUM LEVELS ARE
NOT MUCH BETTER THAN DURING THE DAY MONDAY...BUT LOW LEVEL LAPSE
RATES/LAKE INDUCED CAPE ARE SLIGHTLY BETTER TO SUPPORT SOME LIGHT
ACCUMULATIONS...ESPECIALLY AFTER MIDNIGHT IN NW INDIANA.
AS THE ARCTIC HIGH CONTINUES SOUTH INTO THE PLAINS...WINDS WILL BACK
TO NW AND PUSH LAKE EFFECT SNOWS EASTWARD. 850 TEMPS IN THE MINUS
TEENS SUPPORT HIGHS ONLY IN THE UPPER TEENS TO LOW 20S IN SPITE OF
SOME CLEARING THROUGH THE DAY.
TUESDAY NIGHT/WEDNESDAY MORNING FEATURE THE COLDEST AIR MASS. NW
FLOW PERSISTS WITH MIGRATORY SHORTWAVE ENERGY. WINDS WILL BACK TO
THE WSW THROUGH THE DAY. GIVEN THE COLD START...EXPECT HIGHS SIMILAR
TO TUESDAY AND POSSIBLY A BIT COOLER WITH 20 BEING A STRETCH IN
PLACES.
BY THURSDAY THE UPPER FLOW PATTERN WILL MODIFY AS THE DEEP COLD
TROUGH EXTENDING FROM NORTHERN ONTARIO BACK SOUTHWEST TO THE PACIFIC
GETS PINCHED OFF IN THE NORTH AND SHIFTS EAST OUR FOCUS THEN SHIFTS
TO A CUT OFF LOW OVER CALIFORNIA. SOUTHERLY FLOW AHEAD OF THIS
SYSTEM WILL TRANSPORT SOME SLIGHTLY WARMER AIR ALONG WITH ADDITIONAL
GULF MOISTURE. MEANWHILE...THE SHORTWAVE ENERGY WILL CONTINUE TO
ROTATE SOUTH AND WEST AROUND THE ARCTIC VORTEX THAT AT THIS POINT
SETS UP NORTH OF HUDSON BAY. THE CALI LOW WILL EVENTUALLY EJECT EAST
AND NORTH FRIDAY INTO SATURDAY. THE CLASH OF THE WARMER GULF AIR AND
ARCTIC AIR ENTRENCHED OVER THE REGION LOOKS TO RESULT IN A DYNAMIC
WINTER STORM SYSTEM. PRECIP TYPE WILL BE AN ISSUE SOMEWHERE IN THE
REGION AHEAD OF THE LOW...WITH AN IMPRESSIVE DEFORMATION SNOW BAND
EXPECTING TO SET UP BEHIND IT DUE TO A REPLENISHMENT OF COLD AIR AND
STRONG BAROCLINIC ZONE. A LOT HINGES ON THE INTERACTION WITH THE
NORTHERN STREAM AS TO WHERE THIS SYSTEM HEADS...BUT MODELS TO THIS
POINT HAVE BEEN SOMEWHAT CONSISTENT ON THE TIME FRAME OF CONCERN BEING
LATER FRIDAY AND ESPECIALLY INTO SATURDAY WITH SOME WINTRY
PRECIPITATION SOMEWHERE IN OUR AREA. COLD AIR COMES RIGHT BACK IN
BEHIND IT.
KMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* LAKE EFFECT FLURRIES POSSIBLE MONDAY MORNING.
* MVFR CIGS MONDAY.
JEE
//DISCUSSION...UPDATED 18Z...
HIGH PRESSURE OVER THE AREA WILL RESULT IN LIGHT WINDS ACROSS THE
REGION THROUGH TONIGHT. WINDS TURN NORTH TO NORTHEAST OVERNIGHT
WITH LAKE EFFECT SNOW PUSHING ONSHORE. GYY HAS THE BEST CHANCE OF
SEEING VIS RESTRICTIONS DUE TO SNOW SO HAVE A TEMPO FOR LOW END
MVFR VSBY...AND VSBY COULD BE LOWER. FLURRIES ARE EXPECTED AT MDW
AND ORD. MEDIUM CONFIDENCE IN THE LAKE EFFECT SNOW SET UP AND HOW
FAR INLAND ACCUMULATING SNOW WILL FALL. MVFR CIGS ALSO MOVE IN OFF
OF THE LAKE AND IMPACT THE EASTERN TERMINALS...AND HAVE MEDIUM
CONFIDENCE IN MVFR CIGS REMAINING EAST OF DPA. HIGH CONFIDENCE IN
MVFR CIGS AT MDW...ORD...AND GYY.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM CONFIDENCE IN LAKE EFFECT FLURRIES.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...MVFR CIGS/LAKE EFFECT SNOW SHOWERS POSSIBLE.
TUESDAY THROUGH FRIDAY...SLIGHT CHANCE OF MVFR CIGS AT TIMES
OTHERWISE VFR.
FRIDAY NIGHT AND SATURDAY...CHANCE OF SNOW AND IFR.
IZZI
&&
.MARINE...
150 AM CST
MODERATE NORTHWEST WINDS WILL EASE SOME TODAY AND THEN VEER MORE
NORTHERLY TONIGHT INTO MONDAY. NORTHERLY WINDS WILL FRESHEN UP
MONDAY NIGHT INTO TUESDAY AS ARCTIC AIR SPILLS INTO THE REGION.
WINDS WILL BACK TO SOUTHWEST AND INCREASE FURTHER TO GALES WEDNESDAY
AND CONTINUE THROUGH THURSDAY MORNING AND STRONG LOW PRESSURE MOVES
SOUTH INTO HUDSON BAY TIGHTENING UP THE PRESSURE GRADIENT WITH
ARCTIC AIR FIRMLY ENTRENCHED OVER THE AREA. WINDS LOOK TO SUBSIDE
LATER THURSDAY INTO EARLY FRIDAY BEFORE POTENTIALLY RAMPING UP AGAIN
NEXT WEEKEND AS ANOTHER STORM SYSTEM POTENTIALLY APPROACHES THE
REGION THOUGH SIGNIFICANT MODEL DIFFERENCES EXIST IN TRACK AND
INTENSITY OF THAT SYSTEM.
IZZI
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1058 AM CST Sun Dec 28 2014
.UPDATE...
ISSUED AT 1054 AM CST SUN DEC 28 2014
High pressure settling into the FA this morning, but llvl clouds
trapped under the overnight inversion are slow to erode. NW of
I-55 in Central Illinois is only covered with cirrus this
morning...while SE Illinois has stratus under 2000 ft. Cold arctic
air settling into the region behind yesterdays cold front
resulting in a chilly morning. Temperatures on track with only a
few changes to the hourlys... and no large updates are
anticipated.
&&
.SHORT TERM...(Today)
ISSUED AT 305 AM CST SUN DEC 28 2014
Main short-term challenge will be timing of the clearing trend
today. 08z/2am IR satellite imagery shows low clouds covering much
of central Illinois, except across the far northern KILX CWA from
Peoria northward where clouds have eroded. The 06z NAM 1000-850mb RH
field has a good handle on the current cloud cover, so have
generally followed its solution for sky cover today. End result
will be clearing skies along the I-74 corridor by mid to late
morning, with clouds lingering into the afternoon further south.
Skies will become mostly clear across the board by late afternoon as
high pressure builds in from the west. High temperatures will be
near normal for this time of year in the middle to upper 30s.
&&
.LONG TERM...(Tonight through Saturday)
ISSUED AT 305 AM CST SUN DEC 28 2014
Quiet weather is expected for the next several days before a storm
system gradually approaches from the southwest by the end of the
week. High pressure will control the weather across central
Illinois on Monday, resulting in cool/dry conditions with highs in
the 30s. Meanwhile, a significant chunk of cold air currently in
place across central/western Canada will sink southward into the
central CONUS by the middle of the week. Models have been hinting
at some light snow/flurries as CAA increases Monday night into
Tuesday, with the NAM being more aggressive with potential QPF. NAM
time-height cross-sections reveal stronger lift within a deeper
moist layer than the GFS indicates. Think the low-level moisture
may be a bit overdone on the NAM, so am leaning toward the GFS
solution here. Even with drier air below 850mb, think lift will be
strong enough to warrant mention of a few flurries Monday night and
perhaps even into Tuesday morning before moisture profile thins and
high pressure builds into the region. Heart of the cold airmass
will arrive Tuesday night into Wednesday, when overnight lows dip
into the single digits and teens and highs only reach the lower to
middle 20s.
Once high slowly begins to shift eastward, attention turns to a
developing southern-stream storm system associated with a cut-off
upper low over the Desert Southwest. Models are still displaying
a typical spread of solutions that far out, but confidence is
growing that a precipitation event will impact central Illinois by
the end of the week. Both the GFS and ECMWF show surface low
pressure developing over the Texas panhandle by Friday evening, then
lifting northeastward into the Great Lakes on Saturday. While their
tracks are not in perfect agreement, a N/NW trend is becoming
apparent. GFS takes the low west of the CWA to near Moline by 12z
Sat, while the ECMWF tracks the low to near Champaign. Both tracks
are further N/NW than previous runs, which suggests precip may be
more in the form of rain or a rain/snow mix across the area than
previously thought. Based on GFS forecast soundings, if precip is
able to spread northward into the initially cold/dry airmass Friday
morning, light snow will be the primary precip type. As temps warm
into the middle to upper 30s, the snow will likely mix with rain
across much of the area by Friday afternoon. Precip will likely
remain quite light during the day Friday, with widespread precip
holding off until Friday night when airmass saturates and stronger
lift arrives. At this point, will carry rain along/south of
I-70...a rain/snow mix across the middle of the CWA...and snow
along/north of a Rushville to Bloomington line Friday night into
Saturday. The track of the system will likely change with
successive model runs, so precip type and any potential snow
accumulations still remain uncertain.
&&
.AVIATION...(For the 12Z TAFS through 12Z Monday morning)
ISSUED AT 532 AM CST SUN DEC 28 2014
Main concern across the central Illinois terminals through the 12Z
TAF valid time regards the disposition of the MVFR CIGS today as
high pressure builds into the area. Once the low clouds clear out,
VFR conditions will prevail through the remainder of the period.
The low cloud clearing trends today are tough to pinpoint as the
back edge of the cloud deck is far from smooth. Actually, the back
edge of the cloud deck is ragged, which should allow for skies to
go back/forth between BKN/OVC and SCT for a few hours before
finally clearing. The recent progression of the low clouds has
become difficult to track on satellite imagery due to a cirrus
shield moving over top of the low clouds. However, as best as I
can tell, the HRRR has a pretty good handle on the trends, and
will lean on it for clearing trends this morning into early
afternoon. Northwest winds will continue to diminish in speed as a
weak area of high pressure approaches today, eventually leading to
light/variable winds tonight.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HJS
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...Bak
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
801 AM CST SUN DEC 28 2014
.SHORT TERM...
236 AM CST
THROUGH MONDAY...
HIGH PRESSURE NOSING IN FROM THE WEST RESULTING IN GRADUAL CLEARING
FROM WEST TO EAST EARLY THIS MORNING WITH THE BACK EDGE ALREADY
THOROUGH ROCKFORD. ONCE THE LOW CLOUDS CLEAR EXPECT SOME PASSING HIGH
CLOUDS THIS MORNING EMANATING FROM A MODEST UPPER LOW IN
TEXAS...OTHERWISE IT WILL BE A SEASONAL MOSTLY SUNNY DAY WITH
HIGHS TOPPING OUT IN THE LOW 30S OR SO. WE`LL HOLD A WEST WIND
WHICH WILL MAKE IT FEEL A LITTLE COOLER...THOUGH TODAY LOOKS TO BE
THE WARMEST FOR THE REST OF 2014. ARCTIC HIGH PRESSURE CONTINUES
TO SINK INTO THE CENTER OF THE COUNTRY TONIGHT. LOCALLY...OUR
WINDS TURN NORTHERLY ALLOWING SOME OF THIS CONTINUE MOVING IN.
ZONAL FLOW ALOFT WILL KEEP SOME HIGHER CLOUDS PUSHING INTO THE
REGION PREVENTING A REAL COLD NIGHT...BUT STILL THE COLDEST WE/VE
SEEN IN A WHILE WITH LOWS INTO THE 20S.
BY MONDAY MORNING...A BACKDOOR FRONT MOVING DOWN THE LAKE WILL
CONTINUE THE STREAM OF COLDER AIR. ADDITIONALLY LAKE EFFECT CLOUDS
WILL MOVE INTO NORTHWEST INDIANA AND PORTIONS OF NORTHEAST ILLINOIS.
WITH THE CONTINUED COLD ADVECTION AND MIX OF LOW AND MID
CLOUD...TEMPS WILL STRUGGLE TO GET TO FREEZING IN MANY SPOTS. NAM IS
STILL HINTING AT SOME LAKE EFFECT FLURRIES OR LIGHT SNOW SHOWERS THOUGH
LAKE EFFECT PARAMETERS DURING THE DAY ARE NOT SUPER IMPRESSIVE.
KMD
&&
.LONG TERM...
236 AM CST
MONDAY NIGHT THROUGH SATURDAY...
MONDAY NIGHT...A MORE SIGNIFICANT SURGE OF COLD AIR COMES STREAMING IN.
THIS WILL ENHANCE LAKE EFFECT PARAMETERS...ESPECIALLY IN NORTHWEST
INDIANA AND PORTIONS OF SOUTHERN COOK COUNTY. EQUILIBRIUM LEVELS ARE
NOT MUCH BETTER THAN DURING THE DAY MONDAY...BUT LOW LEVEL LAPSE
RATES/LAKE INDUCED CAPE ARE SLIGHTLY BETTER TO SUPPORT SOME LIGHT
ACCUMULATIONS...ESPECIALLY AFTER MIDNIGHT IN NW INDIANA.
AS THE ARCTIC HIGH CONTINUES SOUTH INTO THE PLAINS...WINDS WILL BACK
TO NW AND PUSH LAKE EFFECT SNOWS EASTWARD. 850 TEMPS IN THE MINUS
TEENS SUPPORT HIGHS ONLY IN THE UPPER TEENS TO LOW 20S IN SPITE OF
SOME CLEARING THROUGH THE DAY.
TUESDAY NIGHT/WEDNESDAY MORNING FEATURE THE COLDEST AIR MASS. NW
FLOW PERSISTS WITH MIGRATORY SHORTWAVE ENERGY. WINDS WILL BACK TO
THE WSW THROUGH THE DAY. GIVEN THE COLD START...EXPECT HIGHS SIMILAR
TO TUESDAY AND POSSIBLY A BIT COOLER WITH 20 BEING A STRETCH IN
PLACES.
BY THURSDAY THE UPPER FLOW PATTERN WILL MODIFY AS THE DEEP COLD
TROUGH EXTENDING FROM NORTHERN ONTARIO BACK SOUTHWEST TO THE PACIFIC
GETS PINCHED OFF IN THE NORTH AND SHIFTS EAST OUR FOCUS THEN SHIFTS
TO A CUT OFF LOW OVER CALIFORNIA. SOUTHERLY FLOW AHEAD OF THIS
SYSTEM WILL TRANSPORT SOME SLIGHTLY WARMER AIR ALONG WITH ADDITIONAL
GULF MOISTURE. MEANWHILE...THE SHORTWAVE ENERGY WILL CONTINUE TO
ROTATE SOUTH AND WEST AROUND THE ARCTIC VORTEX THAT AT THIS POINT
SETS UP NORTH OF HUDSON BAY. THE CALI LOW WILL EVENTUALLY EJECT EAST
AND NORTH FRIDAY INTO SATURDAY. THE CLASH OF THE WARMER GULF AIR AND
ARCTIC AIR ENTRENCHED OVER THE REGION LOOKS TO RESULT IN A DYNAMIC
WINTER STORM SYSTEM. PRECIP TYPE WILL BE AN ISSUE SOMEWHERE IN THE
REGION AHEAD OF THE LOW...WITH AN IMPRESSIVE DEFORMATION SNOW BAND
EXPECTING TO SET UP BEHIND IT DUE TO A REPLENISHMENT OF COLD AIR AND
STRONG BAROCLINIC ZONE. A LOT HINGES ON THE INTERACTION WITH THE
NORTHERN STREAM AS TO WHERE THIS SYSTEM HEADS...BUT MODELS TO THIS
POINT HAVE BEEN SOMEWHAT CONSISTENT ON THE TIME FRAME OF CONCERN BEING
LATER FRIDAY AND ESPECIALLY INTO SATURDAY WITH SOME WINTRY
PRECIPITATION SOMEWHERE IN OUR AREA. COLD AIR COMES RIGHT BACK IN
BEHIND IT.
KMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* LAKE EFFECT CLOUDS/FLURRIES POSSIBLE MONDAY MORNING.
JEE
//DISCUSSION...UPDATED 12Z...
VFR WITH LIGHT WINDS THROUGH TONIGHT. SUBTLE FRONT MOVES ACROSS
AREA LATE TONIGHT AND ALLOWS WINDS TO TURN IN OFF THE LAKE WHICH
SHOULD BRING SOME MVFR CIGS AND PROBABLY SOME FLURRIES INTO NE
ILLINOIS MONDAY MORNING.
IZZI
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* LOW-MEDIUM CONFIDENCE IN LAKE EFFECT CLOUDS/FLURRIES.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...MVFR CIGS/LAKE EFFECT SNOW SHOWERS POSSIBLE.
TUESDAY THROUGH FRIDAY...SLIGHT CHANCE OF MVFR CIGS AT TIMES
OTHERWISE VFR.
FRIDAY NIGHT AND SATURDAY...CHANCE OF SNOW AND IFR.
IZZI
&&
.MARINE...
150 AM CST
MODERATE NORTHWEST WINDS WILL EASE SOME TODAY AND THEN VEER MORE
NORTHERLY TONIGHT INTO MONDAY. NORTHERLY WINDS WILL FRESHEN UP
MONDAY NIGHT INTO TUESDAY AS ARCTIC AIR SPILLS INTO THE REGION.
WINDS WILL BACK TO SOUTHWEST AND INCREASE FURTHER TO GALES WEDNESDAY
AND CONTINUE THROUGH THURSDAY MORNING AND STRONG LOW PRESSURE MOVES
SOUTH INTO HUDSON BAY TIGHTENING UP THE PRESSURE GRADIENT WITH
ARCTIC AIR FIRMLY ENTRENCHED OVER THE AREA. WINDS LOOK TO SUBSIDE
LATER THURSDAY INTO EARLY FRIDAY BEFORE POTENTIALLY RAMPING UP AGAIN
NEXT WEEKEND AS ANOTHER STORM SYSTEM POTENTIALLY APPROACHES THE
REGION THOUGH SIGNIFICANT MODEL DIFFERENCES EXIST IN TRACK AND
INTENSITY OF THAT SYSTEM.
IZZI
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
532 AM CST Sun Dec 28 2014
.SHORT TERM...(Today)
ISSUED AT 305 AM CST SUN DEC 28 2014
Main short-term challenge will be timing of the clearing trend
today. 08z/2am IR satellite imagery shows low clouds covering much
of central Illinois, except across the far northern KILX CWA from
Peoria northward where clouds have eroded. The 06z NAM 1000-850mb RH
field has a good handle on the current cloud cover, so have
generally followed its solution for sky cover today. End result
will be clearing skies along the I-74 corridor by mid to late
morning, with clouds lingering into the afternoon further south.
Skies will become mostly clear across the board by late afternoon as
high pressure builds in from the west. High temperatures will be
near normal for this time of year in the middle to upper 30s.
&&
.LONG TERM...(Tonight through Saturday)
ISSUED AT 305 AM CST SUN DEC 28 2014
Quiet weather is expected for the next several days before a storm
system gradually approaches from the southwest by the end of the
week. High pressure will control the weather across central
Illinois on Monday, resulting in cool/dry conditions with highs in
the 30s. Meanwhile, a significant chunk of cold air currently in
place across central/western Canada will sink southward into the
central CONUS by the middle of the week. Models have been hinting
at some light snow/flurries as CAA increases Monday night into
Tuesday, with the NAM being more aggressive with potential QPF. NAM
time-height cross-sections reveal stronger lift within a deeper
moist layer than the GFS indicates. Think the low-level moisture
may be a bit overdone on the NAM, so am leaning toward the GFS
solution here. Even with drier air below 850mb, think lift will be
strong enough to warrant mention of a few flurries Monday night and
perhaps even into Tuesday morning before moisture profile thins and
high pressure builds into the region. Heart of the cold airmass
will arrive Tuesday night into Wednesday, when overnight lows dip
into the single digits and teens and highs only reach the lower to
middle 20s.
Once high slowly begins to shift eastward, attention turns to a
developing southern-stream storm system associated with a cut-off
upper low over the Desert Southwest. Models are still displaying
a typical spread of solutions that far out, but confidence is
growing that a precipitation event will impact central Illinois by
the end of the week. Both the GFS and ECMWF show surface low
pressure developing over the Texas panhandle by Friday evening, then
lifting northeastward into the Great Lakes on Saturday. While their
tracks are not in perfect agreement, a N/NW trend is becoming
apparent. GFS takes the low west of the CWA to near Moline by 12z
Sat, while the ECMWF tracks the low to near Champaign. Both tracks
are further N/NW than previous runs, which suggests precip may be
more in the form of rain or a rain/snow mix across the area than
previously thought. Based on GFS forecast soundings, if precip is
able to spread northward into the initially cold/dry airmass Friday
morning, light snow will be the primary precip type. As temps warm
into the middle to upper 30s, the snow will likely mix with rain
across much of the area by Friday afternoon. Precip will likely
remain quite light during the day Friday, with widespread precip
holding off until Friday night when airmass saturates and stronger
lift arrives. At this point, will carry rain along/south of
I-70...a rain/snow mix across the middle of the CWA...and snow
along/north of a Rushville to Bloomington line Friday night into
Saturday. The track of the system will likely change with
successive model runs, so precip type and any potential snow
accumulations still remain uncertain.
&&
.AVIATION...(For the 12Z TAFS through 12Z Monday morning)
ISSUED AT 532 AM CST SUN DEC 28 2014
Main concern across the central Illinois terminals through the 12Z
TAF valid time regards the disposition of the MVFR CIGS today as
high pressure builds into the area. Once the low clouds clear out,
VFR conditions will prevail through the remainder of the period.
The low cloud clearing trends today are tough to pinpoint as the
back edge of the cloud deck is far from smooth. Actually, the back
edge of the cloud deck is ragged, which should allow for skies to
go back/forth between BKN/OVC and SCT for a few hours before
finally clearing. The recent progression of the low clouds has
become difficult to track on satellite imagery due to a cirrus
shield moving over top of the low clouds. However, as best as I
can tell, the HRRR has a pretty good handle on the trends, and
will lean on it for clearing trends this morning into early
afternoon. Northwest winds will continue to diminish in speed as a
weak area of high pressure approaches today, eventually leading to
light/variable winds tonight.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...Bak
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
514 AM CST SUN DEC 28 2014
.SHORT TERM...
236 AM CST
THROUGH MONDAY...
HIGH PRESSURE NOSING IN FROM THE WEST RESULTING IN GRADUAL CLEARING
FROM WEST TO EAST EARLY THIS MORNING WITH THE BACK EDGE ALREADY
THOROUGH ROCKFORD. ONCE THE LOW CLOUDS CLEAR EXPECT SOME PASSING HIGH
CLOUDS THIS MORNING EMANATING FROM A MODEST UPPER LOW IN
TEXAS...OTHERWISE IT WILL BE A SEASONAL MOSTLY SUNNY DAY WITH
HIGHS TOPPING OUT IN THE LOW 30S OR SO. WE`LL HOLD A WEST WIND
WHICH WILL MAKE IT FEEL A LITTLE COOLER...THOUGH TODAY LOOKS TO BE
THE WARMEST FOR THE REST OF 2014. ARCTIC HIGH PRESSURE CONTINUES
TO SINK INTO THE CENTER OF THE COUNTRY TONIGHT. LOCALLY...OUR
WINDS TURN NORTHERLY ALLOWING SOME OF THIS CONTINUE MOVING IN.
ZONAL FLOW ALOFT WILL KEEP SOME HIGHER CLOUDS PUSHING INTO THE
REGION PREVENTING A REAL COLD NIGHT...BUT STILL THE COLDEST WE`VE
SEEN IN A WHILE WITH LOWS INTO THE 20S.
BY MONDAY MORNING...A BACKDOOR FRONT MOVING DOWN THE LAKE WILL
CONTINUE THE STREAM OF COLDER AIR. ADDITIONALLY LAKE EFFECT CLOUDS
WILL MOVE INTO NORTHWEST INDIANA AND PORTIONS OF NORTHEAST ILLINOIS.
WITH THE CONTINUED COLD ADVECTION AND MIX OF LOW AND MID
CLOUD...TEMPS WILL STRUGGLE TO GET TO FREEZING IN MANY SPOTS. NAM IS
STILL HINTING AT SOME LAKE EFFECT FLURRIES OR LIGHT SNOW SHOWERS THOUGH
LAKE EFFECT PARAMETERS DURING THE DAY ARE NOT SUPER IMPRESSIVE.
KMD
&&
.LONG TERM...
236 AM CST
MONDAY NIGHT THROUGH SATURDAY...
MONDAY NIGHT...A MORE SIGNIFICANT SURGE OF COLD AIR COMES STREAMING IN.
THIS WILL ENHANCE LAKE EFFECT PARAMETERS...ESPECIALLY IN NORTHWEST
INDIANA AND PORTIONS OF SOUTHERN COOK COUNTY. EQUILIBRIUM LEVELS ARE
NOT MUCH BETTER THAN DURING THE DAY MONDAY...BUT LOW LEVEL LAPSE
RATES/LAKE INDUCED CAPE ARE SLIGHTLY BETTER TO SUPPORT SOME LIGHT
ACCUMULATIONS...ESPECIALLY AFTER MIDNIGHT IN NW INDIANA.
AS THE ARCTIC HIGH CONTINUES SOUTH INTO THE PLAINS...WINDS WILL BACK
TO NW AND PUSH LAKE EFFECT SNOWS EASTWARD. 850 TEMPS IN THE MINUS
TEENS SUPPORT HIGHS ONLY IN THE UPPER TEENS TO LOW 20S IN SPITE OF
SOME CLEARING THROUGH THE DAY.
TUESDAY NIGHT/WEDNESDAY MORNING FEATURE THE COLDEST AIR MASS. NW
FLOW PERSISTS WITH MIGRATORY SHORTWAVE ENERGY. WINDS WILL BACK TO
THE WSW THROUGH THE DAY. GIVEN THE COLD START...EXPECT HIGHS SIMILAR
TO TUESDAY AND POSSIBLY A BIT COOLER WITH 20 BEING A STRETCH IN
PLACES.
BY THURSDAY THE UPPER FLOW PATTERN WILL MODIFY AS THE DEEP COLD
TROUGH EXTENDING FROM NORTHERN ONTARIO BACK SOUTHWEST TO THE PACIFIC
GETS PINCHED OFF IN THE NORTH AND SHIFTS EAST OUR FOCUS THEN SHIFTS
TO A CUT OFF LOW OVER CALIFORNIA. SOUTHERLY FLOW AHEAD OF THIS
SYSTEM WILL TRANSPORT SOME SLIGHTLY WARMER AIR ALONG WITH ADDITIONAL
GULF MOISTURE. MEANWHILE...THE SHORTWAVE ENERGY WILL CONTINUE TO
ROTATE SOUTH AND WEST AROUND THE ARCTIC VORTEX THAT AT THIS POINT
SETS UP NORTH OF HUDSON BAY. THE CALI LOW WILL EVENTUALLY EJECT EAST
AND NORTH FRIDAY INTO SATURDAY. THE CLASH OF THE WARMER GULF AIR AND
ARCTIC AIR ENTRENCHED OVER THE REGION LOOKS TO RESULT IN A DYNAMIC
WINTER STORM SYSTEM. PRECIP TYPE WILL BE AN ISSUE SOMEWHERE IN THE
REGION AHEAD OF THE LOW...WITH AN IMPRESSIVE DEFORMATION SNOW BAND
EXPECTING TO SET UP BEHIND IT DUE TO A REPLENISHMENT OF COLD AIR AND
STRONG BAROCLINIC ZONE. A LOT HINGES ON THE INTERACTION WITH THE
NORTHERN STREAM AS TO WHERE THIS SYSTEM HEADS...BUT MODELS TO THIS
POINT HAVE BEEN SOMEWHAT CONSISTENT ON THE TIME FRAME OF CONCERN BEING
LATER FRIDAY AND ESPECIALLY INTO SATURDAY WITH SOME WINTRY
PRECIPITATION SOMEWHERE IN OUR AREA. COLD AIR COMES RIGHT BACK IN
BEHIND IT.
KMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* LAKE EFFECT CLOUDS/FLURRIES POSSIBLE MONDAY MORNING
IZZI
//DISCUSSION...UPDATED 12Z...
VFR WITH LIGHT WINDS THROUGH TONIGHT. SUBTLE FRONT MOVES ACROSS
AREA LATE TONIGHT AND ALLOWS WINDS TO TURN IN OFF THE LAKE WHICH
SHOULD BRING SOME MVFR CIGS AND PROBABLY SOME FLURRIES INTO NE
ILLINOIS MONDAY MORNING.
IZZI
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* LOW-MEDIUM CONFIDENCE IN LAKE EFFECT CLOUDS/FLURRIES
* HIGH CONFIDENCE IN EVERYTHING ELSE
IZZI
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...MVFR CIGS/LAKE EFFECT SNOW SHOWERS POSSIBLE.
TUESDAY THROUGH FRIDAY...SLIGHT CHANCE OF MVFR CIGS AT TIMES
OTHERWISE VFR.
FRIDAY NIGHT AND SATURDAY...CHANCE OF SNOW AND IFR.
IZZI
&&
.MARINE...
150 AM CST
MODERATE NORTHWEST WINDS WILL EASE SOME TODAY AND THEN VEER MORE
NORTHERLY TONIGHT INTO MONDAY. NORTHERLY WINDS WILL FRESHEN UP
MONDAY NIGHT INTO TUESDAY AS ARCTIC AIR SPILLS INTO THE REGION.
WINDS WILL BACK TO SOUTHWEST AND INCREASE FURTHER TO GALES WEDNESDAY
AND CONTINUE THROUGH THURSDAY MORNING AND STRONG LOW PRESSURE MOVES
SOUTH INTO HUDSON BAY TIGHTENING UP THE PRESSURE GRADIENT WITH
ARCTIC AIR FIRMLY ENTRENCHED OVER THE AREA. WINDS LOOK TO SUBSIDE
LATER THURSDAY INTO EARLY FRIDAY BEFORE POTENTIALLY RAMPING UP AGAIN
NEXT WEEKEND AS ANOTHER STORM SYSTEM POTENTIALLY APPROACHES THE
REGION THOUGH SIGNIFICANT MODEL DIFFERENCES EXIST IN TRACK AND
INTENSITY OF THAT SYSTEM.
IZZI
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
305 AM CST Sun Dec 28 2014
.SHORT TERM...(Today)
ISSUED AT 305 AM CST SUN DEC 28 2014
Main short-term challenge will be timing of the clearing trend
today. 08z/2am IR satellite imagery shows low clouds covering much
of central Illinois, except across the far northern KILX CWA from
Peoria northward where clouds have eroded. The 06z NAM 1000-850mb RH
field has a good handle on the current cloud cover, so have
generally followed its solution for sky cover today. End result
will be clearing skies along the I-74 corridor by mid to late
morning, with clouds lingering into the afternoon further south.
Skies will become mostly clear across the board by late afternoon as
high pressure builds in from the west. High temperatures will be
near normal for this time of year in the middle to upper 30s.
&&
.LONG TERM...(Tonight through Saturday)
ISSUED AT 305 AM CST SUN DEC 28 2014
Quiet weather is expected for the next several days before a storm
system gradually approaches from the southwest by the end of the
week. High pressure will control the weather across central
Illinois on Monday, resulting in cool/dry conditions with highs in
the 30s. Meanwhile, a significant chunk of cold air currently in
place across central/western Canada will sink southward into the
central CONUS by the middle of the week. Models have been hinting
at some light snow/flurries as CAA increases Monday night into
Tuesday, with the NAM being more aggressive with potential QPF. NAM
time-height cross-sections reveal stronger lift within a deeper
moist layer than the GFS indicates. Think the low-level moisture
may be a bit overdone on the NAM, so am leaning toward the GFS
solution here. Even with drier air below 850mb, think lift will be
strong enough to warrant mention of a few flurries Monday night and
perhaps even into Tuesday morning before moisture profile thins and
high pressure builds into the region. Heart of the cold airmass
will arrive Tuesday night into Wednesday, when overnight lows dip
into the single digits and teens and highs only reach the lower to
middle 20s.
Once high slowly begins to shift eastward, attention turns to a
developing southern-stream storm system associated with a cut-off
upper low over the Desert Southwest. Models are still displaying
a typical spread of solutions that far out, but confidence is
growing that a precipitation event will impact central Illinois by
the end of the week. Both the GFS and ECMWF show surface low
pressure developing over the Texas panhandle by Friday evening, then
lifting northeastward into the Great Lakes on Saturday. While their
tracks are not in perfect agreement, a N/NW trend is becoming
apparent. GFS takes the low west of the CWA to near Moline by 12z
Sat, while the ECMWF tracks the low to near Champaign. Both tracks
are further N/NW than previous runs, which suggests precip may be
more in the form of rain or a rain/snow mix across the area than
previously thought. Based on GFS forecast soundings, if precip is
able to spread northward into the initially cold/dry airmass Friday
morning, light snow will be the primary precip type. As temps warm
into the middle to upper 30s, the snow will likely mix with rain
across much of the area by Friday afternoon. Precip will likely
remain quite light during the day Friday, with widespread precip
holding off until Friday night when airmass saturates and stronger
lift arrives. At this point, will carry rain along/south of
I-70...a rain/snow mix across the middle of the CWA...and snow
along/north of a Rushville to Bloomington line Friday night into
Saturday. The track of the system will likely change with
successive model runs, so precip type and any potential snow
accumulations still remain uncertain.
&&
.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
ISSUED AT 1142 PM CST SAT DEC 27 2014
Precip has shifted east of all the terminal sites, and MVFR clouds
will blanket the area the rest of the night and through much of
the morning tomorrow. CMI has a brief break in the MVFR clouds
until 07z/1am, but low clouds will fill in by 07z. The back edge
of the clouds is positioned to our west from south-central
Wisconsin through SE Iowa and down through the middle of Missouri.
The clearing progression has slowed later this evening, and that
trend should allow low clouds to linger over the terminal sites
into tomorrow morning. PIA should be the first to clear out,
possibly as early as 12-13z. Clearing trends should speed up with
turbulent mixing of dry air tomorrow, reaching BMI by 14z, SPI by
16z, CMI by 18z and DEC by 19z. The HRRR is quicker with clearing,
as is the RAP. Will stick with a more pessimistic clearing trend
until satellite images give more confidence in the models cloud
progressions. Wind speeds will decrease below 10kt by 08z-09z
tonight, and remain less than 10kt through the day tomorrow. Wind
direction will start out NW, then back to the west during the day
as high pressure builds farther into Illinois.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
150 AM CST SUN DEC 28 2014
.SHORT TERM...
307 PM CST
REMAINDER OF THIS AFTERNOON AND TONIGHT...
A STRONG COLD FRONT IS TRACKING ACROSS THE REGION...USHERING IN MUCH
COOLER AIR ALONG WITH SOME SCT LIGHT PCPN. AS OF 230PM CDT...THE
SFC FRONTAL BOUNDARY EXTENDED FROM WESTERN LOWER MICHIGAN...TO
EAST-CENTRAL IL...TO SERN MO. WINDS HAVE BEEN GUSTING TO ARND 30
MPH FOLLOWING THE FROPA WHILE VEERING FROM SWLY TO WLY.
TEMPERATURES ARE SLOWLY DROPPING OFF WITH THE FROPA AND THE BULK OF
THE PCPN IS POST-FRONTAL AS A STRONG LOW LEVEL JET HAS SET UP ALONG
AN ELEVATED BAROCLINIC ZONE. SOME SCT RAIN IS STILL POSSIBLE OVER
NWRN IN AND ECNTRL IL AHEAD OF THE FRONT...BUT AS COOLER AIR FILTERS
IN BEHIND THE BOUNDARY...LIQUID PCPN IN THE POST-SFC FRONTAL
BOUNDARY SHOULD TRANSITION INTO A MIX OF RAIN...SNOW AND POSSIBLE
SOME GRAPPLE. THE SHARPER TEMPERATURE DROPOFF WILL OCCUR LATER THIS
AFTERNOON AND THROUGH THIS EVENING AS A SECONDARY TROUGH ASSOCIATED
WITH A SURGE OF COOLER AIR PUSHED ACROSS THE EVENING WHICH WILL BE
ACCOMPANIED BY A WIND SHIFT TO WLY-WNWLY. ANY LINGERING PCPN SHOULD
PUSH END OVER NWRN IL-ECNTRL IL DURG THE LATE EVENING HOURS AND
TEMPERATURES OVERNIGHT SHOULD RANGE FROM ARND 20F OVER THE ROCKFORD
AREA TO THE UPPER 20S EAST OF THE I-55 CORRIDOR.
KREIN
&&
.LONG TERM...
307 PM CST
SUNDAY THROUGH SATURDAY...
THE PASSAGE OF THE SYSTEM CURRENTLY MOVING THROUGH THE REGION IS A
SIGNAL OF A MAJOR PATTERN SHIFT FROM THE UNSEASONABLY WARM
CONDITIONS OF RECENT DAYS BACK TO MORE SEASONABLE CONDITIONS AS THE
SHORT-WAVELENGTH...HIGH AMPLITUDE TROUGH SHEARS OUT INTO BROAD WEAK
TROUGHING ALOFT THROUGH THE REMAINDER OF THE WEEKEND. THE GENERAL
TEMPERATURE TREND FOR SUNDAY AND INTO EARLY NEXT WEEK WILL BE FOR A
SLOW COOLING TREND UNDER BROAD...WEAK HEIGHT FALLS ALOFT. A
STRONGER SURGE OF COLD AIR WITH A SERIES OF NRN STREAM SHORTWAVES
WILL USHER IN THE TRUE COLD AIR BY MONDAY NIGHT AND TUESDAY WITH
TEMPERATURES MONDAY MORNING DROPPING OFF INTO THE LOWER TEENS OVER
THE ROCKFORD AREA TO AROUND 20F EAST OF THE I-55 CORRIDOR. THE
UPPER LEVEL PATTERN WILL SET UP TO MORE ZONAL OVER THE SRN CONUS
AS THE MAIN JET PATTERN SHIFTS TO THE SOUTH WHILE POLAR-SOURCED
SHORT WAVE ENERGY DROPS INTO THE UPPER MISSISSIPPI VALLEY AND
THROUGH THE MIDWEST AND GREAT LAKES REGIONS THROUGH THE REMAINDER OF
NEXT WEEK. THE LARGE SCALE PATTERN WILL ALSO BECOME LESS
PROGRESSIVE...WITH THE LONGER RANGE GUIDANCE INDICATING A CUT OFF
LOW DIGGING INTO SRN CALIFORNIA AND VERY SLOWLY TRACKING EWD THROUGH
THE DESERT SOUTHWEST BY LATE NEXT WEEK WHILE SUB-TROPICAL HIGH
PRESSURE REMAINS PARKED OVER THE WESTERN CARIBBEAN AND GREATER
ANTILLES. THE SLOWING PROGRESSION TO THE LONGWAVE PATTERN WILL IN
TURN SET UP A PERIOD WITH A SERIES OF NRN STREAM SHORTWAVES KEEPING
A STEADY STREAM OF SEASONABLY COLD AIR INTO THE REGION. THE NEXT
CHANCE FOR ANY PCPN ACROSS THE AREA WILL BE MONDAY AFTERNOON INTO
TUESDAY AS A COLD FRONT ON THE LEADING EDGE OF AN ARCTIC AIRMASS
TRIES TO SQUEEZE OUT A LITTLE SNOW IN A RELATIVELY DRY ENVIRONMENT.
LITTLE OR NO ACCUMULATION IS EXPECTED OVER MUCH OF THE AREA...
PERHAPS A DUSTING WITH SCT SNOW SHOWERS. HOWEVER...AS SFC HIGH
PRESSURE BUILDS ACROSS THE UPPER MISSISSIPPI VALLEY AND INTO THE
GREAT LAKES REGIONS...A PERIOD OF GENERALLY NORTHERLY FLOW WILL SET
UP OVER LAKE MICHIGAN...AND THERE WILL BE A CHANCE FOR SOME LAKE
EFFECT SNOW INITIALLY ALONG THE ILLINOIS LAKE MICHIGAN SHORE MONDAY
EVENING AND THEN GRADUALLY TRANSITIONING TO THE EAST OVER NWRN
INDIANA MONDAY NIGHT INTO TUESDAY MORNING AS FLOW BACKS MORE NWLY.
IT IS STILL A LITTLE EARLY TO DISCUSS ACCUMULATIONS WITH LAKE EFFECT
SNOW AT THIS POINT...BUT HAVE INCREASED POPS TO LIKELY FOR THE
FAVORED LAKE EFFECT AREAS AND WOULD ANTICIPATE SOME MEASURABLE
ACCUMULATION. MIDWEEK SHOULD BE DRY...BUT WITH THE LOWEST
TEMPERATURES OF THE PERIOD AS THE SFC HIGH PRESSURE SETTLES INTO THE
LOWER MISSISSIPPI VALLEY AND SERN CONUS. BY LATE NEXT WEEK...THE
LONGER RANGE GUIDANCE IS INDICATING THAT THE CUT OFF LOW DROPPING
INTO THE DESERT SOUTHWEST WILL FINALLY BEGIN TO LIFT OUT TO THE
NORTHEAST WHILE A NRN STREAM SHORTWAVE DROPS THROUGH THE NRN PLAINS
TO THE UPPER MISSISSIPPI VALLEY. HOWEVER...WHILE THE LONGER RANGE
GUIDANCE IS IN RELATIVELY DECENT AGREEMENT ON THE TREND...THERE ARE
CONSIDERABLE DIFFERENCES IN THE TIMING WITH THE GFS MUCH FASTER THAN
THE ECMWF OR GEM. GIVEN THAT SOUTHWEST CUT-OFF LOWS TEND TO LINGER
LONGER THAN THE MODELS LIKE TO FORECAST...HAVE TRENDED THE LONGER
TERM FORECAST CLOSER TO THE SLOWER SOLUTIONS...AND WOULD NOT BE
SURPRISED TO SEE THE MODELS TREND EVEN SLOWER THAN CURRENTLY
INDICATED. SO...WILL LIMIT POPS TO CHANCE LEVELS WITH TEMPERATURES
CONDUCIVE TO SNOW FOR NOW.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* MVFR CIGS CLEAR OUT PRIOR TO SUNRISE
IZZI
//DISCUSSION...UPDATED 06Z...
BACK EDGE OF THE STRATUS UPSTREAM OVER NW IL AND SW WI WILL
CONTINUE STEADY SOUTHEAST PROGRESS OVERNIGHT WITH CONDITIONS
EXPECTED TO GO VFR PRIOR TO SUNRISE AT ALL TERMINALS. OTHERWISE
LOOK FOR LIGHT WINDS AND CLEAR SKIES REMAINDER OF TAF CYCLE.
IZZI
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM CONFIDENCE ON PRECISE TIMING OF CLEARING
* HIGH CONFIDENCE IN EVERYTHING ELSE
IZZI
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY...CHC SNOW LATE.
TUESDAY THROUGH THURSDAY...PRIMARILY VFR.
FRIDAY...CHC SNOW. MVFR/IFR PSBL.
BMD
&&
.MARINE...
150 AM CST
MODERATE NORTHWEST WINDS WILL EASE SOME TODAY AND THEN VEER MORE
NORTHERLY TOONIGHT INTO MONDAY. NORTHERLY WINDS WILL FRESHEN UP
MONDAY NIGHT INTO TUESDAY AS ARCTIC AIR SPILLS INTO THE REGION.
WINDS WILL BACK TO SOUTHWEST AND INCREASE FURTHER TO GALES WEDNESDAY
AND CONTINUE THROUGH THURSDAY MORNING AND STRONG LOW PRESSURE MOVES
SOUTH INTO HUDSON BAY TIGHTENING UP THE PRESSURE GRADIENT WITH
ARCTIC AIR FIRMLY ENTRENTCHED OVER THE AREA. WINDS LOOK TO SUBSIDE
LATER THURSDAY INTO EARLY FRIDAY BEFORE POTENTIALLY RAMPING UP AGAIN
NEXT WEEKEND AS ANOTHER STORM SYSTEM POTENTIALLY APPROACHES THE
REGION THOUGH SIGNIFICANT MODEL DIFFERENCES EXIST IN TRACK AND
INTENSITY OF THAT SYSTEM.
IZZI
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL 4 AM SUNDAY.
&&
$$
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1142 PM CST Sat Dec 27 2014
.UPDATE...
ISSUED AT 900 PM CST SAT DEC 27 2014
The cold air aloft driving into the north side of the system has
been changing the rain over to snow and sleet for a couple of
hours at the end of precipitation. There seems to be less evidence
of the snow/sleet band in the observations and reports over the last
hour or so, but the air temps are dropping toward freezing in the
back edge of the precip, so will continue to indicate a band of
snow/sleet at the western edge of precip until precip comes to an
end later tonight. Any light snow/sleet accumulation would create
slippery roads. Road temps have generally been reporting above
freezing, but some bridges, overpasses, and secondary roads would
be more susceptible to icing. The precip is increasing its forward
progress toward Indiana, and we have adjusted the weather grids to
end precip a few hours sooner tonight. All precip will likely be
out of our counties by 1 am and possibly midnight.
Gusty northwest winds will develop after precip ends, ushering the
colder air. Some clearing is forecast for our NW counties later
tonight, which would allow low temps to drop off a bit farther
than guidance. Will trim a couple degrees off lows toward
Galesburg/Lacon. Updated forecast grids and info will be available
shortly.
&&
.SHORT TERM...(Tonight)
ISSUED AT 313 PM CST SAT DEC 27 2014
Low clouds, drizzle, light rain showers still ongoing across the
forecast area this afternoon. Cold front about out of ILX
area...just NW of Lawrenceville. Some flakes mixing into the precip
on the extreme NW edge of the post frontal echos on radar. Front
progression somewhat steady although running into more parallel flow
aloft. Cold dense air from the NW really colder behind the post
frontal precip spread across the radar mosaic. Timing of the cold
air a minor concern as time progresses. Ground temps still close to
40 degrees, but with the arrival of the freezing temps, some
elevated surfaces could develop some slick spots. The arrival of the
coldest air will be after the precip has come to an end...so
freezing should be confined to the residual moisture/puddles from
today`s drizzle/rain. Another issue with the overnight forecast is
the cloud cover. GFS is quick to break it out...a little faster than
is currently represented on sat imagery. NAM is far cloudier,
trapping the moisture in the boundary layer and preventing the mix
out entirely. RUC looking more like the NAM with representing the
developing inversion behind the boundary. Plenty of dry air up
there, but how quickly it will erode through the clouds is a huge
question mark. Covered in cirrus all day, not convinced the diurnal
influence on the clouds is enough to erode them at sunset.
Considering how quickly sunset is approaching, going to split the
difference more or less with a slower clearing out...but not quite
as trapped as the NAM. Some breaking up could be seen in the far NW,
and forecast low temps are considerably cooler as a result.
However, going cloudier overall through the night.
&&
.LONG TERM...(Sunday through Saturday)
ISSUED AT 313 PM CST SAT DEC 27 2014
High pressure behind the front will bring dry weather to the area
for tomorrow through Monday. However, this mild high pressure area
will be temporary as a stronger/colder high pressure area drops into
the region Tuesday. A weak boundary will be between these two high
pressure areas, but it will have very little moisture to work with.
This will be an Arctic front with much colder air behind it. Any
precip with this Arctic front will be very light and could occur
Monday night. With the colder temps and limited moisture, only pcpn
expected will be flurries. Also believe this will be across the
northern 2/3rds of the CWA, leaving the southeastern CWA dry as the
area flurries moves east.
Temps will be around normal tomorrow and Monday, but then drop to
below normal for Tue as the Arctic cold high pressure moves in.
Cold, dry Arctic high pressure will dominate the area for days 3-5,
but as the high pressure modifies and moves into southeastern US,
temps will begin to warm gradually and a weather system will develop
in the southwestern US and begin to move out into the plains. With
high pressure to the east and a surface low pressure area to the
west, warmer air will not be the only thing to return to the area.
Moisture will also return and this will bring pcpn to the area as
the moisture interacts with a warm front and lifts northward into
the area. P-type could be very interesting and be dependent on the
surface temperature and temps in the lower levels. Models
forecasting temps above zero at 850mb over the area, which would
indicate rain. However, surface temps look to be below freezing Fri
night; and this could mean frozen pcpn possible. Considering Fri
through Sat is Day6-7, will not get too detailed on pcpn type and
just go with snow or rain, or a mix of rain and snow. Thinking
mostly rain on Friday with a mix in the north, then a mix becoming
all snow on Fri night, and then all snow in the east on Sat. Am
expecting the p-type to change over the next several days, and when
the event becomes better defined by the models and closer.
As mentioned earlier, temps will start cold and then gradually warm
during the week.
&&
.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
ISSUED AT 1142 PM CST SAT DEC 27 2014
Precip has shifted east of all the terminal sites, and MVFR clouds
will blanket the area the rest of the night and through much of
the morning tomorrow. CMI has a brief break in the MVFR clouds
until 07z/1am, but low clouds will fill in by 07z. The back edge
of the clouds is positioned to our west from south-central
Wisconsin through SE Iowa and down through the middle of Missouri.
The clearing progression has slowed later this evening, and that
trend should allow low clouds to linger over the terminal sites
into tomorrow morning. PIA should be the first to clear out,
possibly as early as 12-13z. Clearing trends should speed up with
turbulent mixing of dry air tomorrow, reaching BMI by 14z, SPI by
16z, CMI by 18z and DEC by 19z. The HRRR is quicker with clearing,
as is the RAP. Will stick with a more pessimistic clearing trend
until satellite images give more confidence in the models cloud
progressions. Wind speeds will decrease below 10kt by 08z-09z
tonight, and remain less than 10kt through the day tomorrow. Wind
direction will start out NW, then back to the west during the day
as high pressure builds farther into Illinois.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Shimon
SHORT TERM...HJS
LONG TERM...Auten
AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1216 PM EST SUN DEC 28 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 335 AM EST SUN DEC 28 2014
A COLD FRONT ACROSS OHIO AND NORTHWEST KENTUCKY WILL CONTINUE MOVING
SOUTHEAST. THIS WILL BE FOLLOWED BY A RIDGE OF HIGH PRESSURE WHICH
WILL MOVE SUNDAY NIGHT AND MONDAY. A DRY SECONDARY ARCTIC COLD
FRONT WILL MOVE SOUTHEAST ACROSS OUR REGION AROUND TUESDAY. IN THE
LONG TERM AN ARCTIC HIGH PRESSURE SYSTEM WILL BRING DRY AND COLD
WEATHER. HOWEVER MIXED PRECIPITATION IS POSSIBLE AGAIN THIS FRIDAY
THROUGH NEXT SATURDAY AS MODELS SHOW A LOW PRESSURE SYSTEM MOVING
INTO THE LOWER MISSISSIPPI VALLEY FRIDAY AND ACROSS OUR REGION
SATURDAY.
&&
.NEAR TERM /TODAY AND TONIGHT/...
ISSUED AT 335 AM EST SUN DEC 28 2014
RADAR SHOWS PRECIPITATION WAS ENDING RAPIDLY FROM THE NORTHWEST AND
WILL PRETTY MUCH BE DONE BY FORECAST RELEASE TIME. SOME SITES ACROSS
OUR SOUTH AND SOUTHEAST MAY SEE A LITTLE DRIZZLE PRIOR TO 7AM.
MAIN ISSUES TODAY WILL BE HOW LONG CLOUDS WILL REMAIN AND
TEMPERATURES. SATELLITE SHOWS CLEARING LINE ACROSS NORTHWEST
ILLINOIS. ALTHOUGH THERE HAVE BEEN A FEW HOLES FARTHER SOUTHEAST.
THE RAP MODEL SOUNDINGS INDICATE MOSTLY CLOUDY SKIES THIS MORNING
AND DECREASING CLOUDS FROM MIDDAY ON. EXPECT CLOUDS TO PERSIST OVER
SOUTHERN SECTIONS MOST OF TODAY AS THIS WILL BE LAST AREA TO CLEAR
OUT. HIGH TEMPERATURES TODAY WILL RANGE FROM THE MIDDLE 30S NORTH TO
AROUND 40 FAR SOUTH WHICH IS SLIGHTLY BELOW A MOS BLEND ON
TEMPERATURES.
TONIGHT WILL BECOME MOSTLY CLEAR AS WEAK RIDGE OF HIGH PRESSURE
MOVES INTO OUR REGION. WENT CLOSE TO A MOS BLEND ON TEMPERATURES
WITH LOWS IN THE LOWER 20S OVER NORTHERN SECTIONS AND THE MIDDLE AND
UPPER 20S SOUTH.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
ISSUED AT 335 AM EST SUN DEC 28 2014
MONDAY WILL BE SEASONABLY COOL WITH WEAK COLD ADVECTION AND HIGH
PRESSURE BUILDING IN FROM THE NORTHWEST. LOW LEVEL THICKNESS
INDICATE HIGHS SHOULD BE FROM THE MIDDLE 30S OVER NORTHERN SECTIONS
TO AROUND 40 FAR SOUTH WITH MOSTLY SUNNY SKIES.
MODELS INDICATE A WEAK UPPER DISTURBANCE WILL TRACK ACROSS INDIANA
LATE MONDAY NIGHT AS A SECONDARY ARCTIC COLD FRONT MOVES OUR WAY.
THE NAM SHOWS SOME QPF ACROSS OUR NORTHWEST LATE MONDAY NIGHT WHILE
ALL OTHER MODELS ARE DRY. ALL MODELS INDICATE SOME CLOUDS WITH THIS
FEATURE WILL MOVE INTO OUR NORTH LATE MONDAY NIGHT. AS A COMPROMISE
WILL MENTION A CHANCE OF FLURRIES NORTHWEST SECTIONS LATE MONDAY
NIGHT. OTHERWISE...IT SHOULD REMAIN DRY.
THIS SYSTEM WILL QUICKLY MOVE ON TO THE EAST TUESDAY. 850 MB
TEMPERATURES WHICH WILL BE AROUND -5 TO -8 MONDAY WILL COOL TO -10
TO -13 CELSIUS TUESDAY. THUS SURFACE TEMPERATURES WILL BE A LITTLE
COLDER TUESDAY AND EVEN COLDER ON WEDNESDAY AS MORE ARCTIC AIR
PUSHES SOUTH INTO OUR REGION. IN MOST CASES MOS SEEMS TO TO
HANDLING THIS OK AND ONLY MINOR TWEAKS MADE.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY NIGHT/...
ISSUED AT 352 AM EST SUN DEC 28 2014
THE MAIN FOCUS OF THE LONG TERM PERIOD CONTINUES TO BE A LOW
PRESSURE SYSTEM LATE IN THE PERIOD. FIRST...ZONAL FLOW ALOFT WILL
RESULT IN DRY CONDITIONS FROM WEDNESDAY THROUGH THURSDAY. FOCUS
THEN TURNS TO THE APPROACHING LOW PRESSURE SYSTEM FROM THE
SOUTHWEST. MOST RECENT MODEL RUNS ARE SHOWING BETTER CONSISTENCY IN
THE TRACK COMPARED TO YESTERDAY. NOW THE GFS AND EURO ARE BOTH ON
BOARD WITH THE LOW PRESSURE SYSTEM TRACKING FROM THE DESERT
SOUTHWEST...ACROSS THE CENTRAL PLAINS...AND UP INTO CENTRAL
INDIANA. LATEST INITIALIZATION WAS A TAD FAST WITH BRINGING PRECIP
INTO SOUTHERN PORTIONS OF THE FORECAST AREA AS EARLY AS THURSDAY
NIGHT. NONE OF THE MODELS SEEM TO BE TRENDING THAT FAST...SO
REMOVED MENTION OF ANY PRECIP FOR THURSDAY NIGHT.
PRECIP CHANCES WILL INCREASE QUICKLY BY FRIDAY AFTERNOON AS LOW
PRESSURE SYSTEM TRAVERSES THE MISSOURI VALLEY. THE LIKELY POPS ON
FRIDAY NIGHT THAT REGIONAL INITIALIZATION IS TRENDING TOWARD MATCH
NICELY. SO...WILL NOT MAKE ANY DEVIATIONS TO POPS FOR FRIDAY AND
SATURDAY. CONFIDENCE IN PRECIP TYPE IS STILL LOW UNTIL THE EXACT
TRACK BECOMES SOLIDIFIED...BUT IT/S LOOKING LIKE SNOW OVER THE
NORTHERN THIRD OF THE FORECAST AREA WITH RAIN/SNOW AND RAIN OVER THE
REMAINING TWO-THIRDS OF CENTRAL INDIANA.
&&
.AVIATION /DISCUSSION FOR THE 281800Z TAF ISSUANCE/...
ISSUED AT 1213 PM EST SUN DEC 28 2014
MVFR CONDITIONS WILL PREVAIL FOR ABOUT 4-5 HOURS LONGER THAN
EXPECTED EXCEPT FOR SITE KHUF WHICH HAS ALREADY SAW SOME
SCATTERING OUT IN THE LOW LEVELS. THEN ALL SITES IMPROVING TO VFR
CATEGORY BY LATE THIS AFTERNOON. (EARLY EVENING FOR SITE KBMG WHICH
IS FARTHER TO THE SOUTH AND EAST.) AS HIGH PRESSURE STRENGTHENS OVER
THE AREA...CLOUDS WILL SCATTER OUT FURTHER LATE IN TAF PERIOD AND
REMAIN AT VFR CATEGORY. WINDS WILL BE NORTHERLY AND LIGHT AT 2 TO
6 KTS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JH
NEAR TERM...JH
SHORT TERM...JH
LONG TERM....TDUD
AVIATION...SMF
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSINDIANAPOLIS
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AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
922 AM EST SUN DEC 28 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 335 AM EST SUN DEC 28 2014
A COLD FRONT ACROSS OHIO AND NORTHWEST KENTUCKY WILL CONTINUE MOVING
SOUTHEAST. THIS WILL BE FOLLOWED BY A RIDGE OF HIGH PRESSURE WHICH
WILL MOVE SUNDAY NIGHT AND MONDAY. A DRY SECONDARY ARCTIC COLD
FRONT WILL MOVE SOUTHEAST ACROSS OUR REGION AROUND TUESDAY. IN THE
LONG TERM AN ARCTIC HIGH PRESSURE SYSTEM WILL BRING DRY AND COLD
WEATHER. HOWEVER MIXED PRECIPITATION IS POSSIBLE AGAIN THIS FRIDAY
THROUGH NEXT SATURDAY AS MODELS SHOW A LOW PRESSURE SYSTEM MOVING
INTO THE LOWER MISSISSIPPI VALLEY FRIDAY AND ACROSS OUR REGION
SATURDAY.
&&
.NEAR TERM /TODAY AND TONIGHT/...
ISSUED AT 335 AM EST SUN DEC 28 2014
RADAR SHOWS PRECIPITATION WAS ENDING RAPIDLY FROM THE NORTHWEST AND
WILL PRETTY MUCH BE DONE BY FORECAST RELEASE TIME. SOME SITES ACROSS
OUR SOUTH AND SOUTHEAST MAY SEE A LITTLE DRIZZLE PRIOR TO 7AM.
MAIN ISSUES TODAY WILL BE HOW LONG CLOUDS WILL REMAIN AND
TEMPERATURES. SATELLITE SHOWS CLEARING LINE ACROSS NORTHWEST
ILLINOIS. ALTHOUGH THERE HAVE BEEN A FEW HOLES FARTHER SOUTHEAST.
THE RAP MODEL SOUNDINGS INDICATE MOSTLY CLOUDY SKIES THIS MORNING
AND DECREASING CLOUDS FROM MIDDAY ON. EXPECT CLOUDS TO PERSIST OVER
SOUTHERN SECTIONS MOST OF TODAY AS THIS WILL BE LAST AREA TO CLEAR
OUT. HIGH TEMPERATURES TODAY WILL RANGE FROM THE MIDDLE 30S NORTH TO
AROUND 40 FAR SOUTH WHICH IS SLIGHTLY BELOW A MOS BLEND ON
TEMPERATURES.
TONIGHT WILL BECOME MOSTLY CLEAR AS WEAK RIDGE OF HIGH PRESSURE
MOVES INTO OUR REGION. WENT CLOSE TO A MOS BLEND ON TEMPERATURES
WITH LOWS IN THE LOWER 20S OVER NORTHERN SECTIONS AND THE MIDDLE AND
UPPER 20S SOUTH.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
ISSUED AT 335 AM EST SUN DEC 28 2014
MONDAY WILL BE SEASONABLY COOL WITH WEAK COLD ADVECTION AND HIGH
PRESSURE BUILDING IN FROM THE NORTHWEST. LOW LEVEL THICKNESS
INDICATE HIGHS SHOULD BE FROM THE MIDDLE 30S OVER NORTHERN SECTIONS
TO AROUND 40 FAR SOUTH WITH MOSTLY SUNNY SKIES.
MODELS INDICATE A WEAK UPPER DISTURBANCE WILL TRACK ACROSS INDIANA
LATE MONDAY NIGHT AS A SECONDARY ARCTIC COLD FRONT MOVES OUR WAY.
THE NAM SHOWS SOME QPF ACROSS OUR NORTHWEST LATE MONDAY NIGHT WHILE
ALL OTHER MODELS ARE DRY. ALL MODELS INDICATE SOME CLOUDS WITH THIS
FEATURE WILL MOVE INTO OUR NORTH LATE MONDAY NIGHT. AS A COMPROMISE
WILL MENTION A CHANCE OF FLURRIES NORTHWEST SECTIONS LATE MONDAY
NIGHT. OTHERWISE...IT SHOULD REMAIN DRY.
THIS SYSTEM WILL QUICKLY MOVE ON TO THE EAST TUESDAY. 850 MB
TEMPERATURES WHICH WILL BE AROUND -5 TO -8 MONDAY WILL COOL TO -10
TO -13 CELSIUS TUESDAY. THUS SURFACE TEMPERATURES WILL BE A LITTLE
COLDER TUESDAY AND EVEN COLDER ON WEDNESDAY AS MORE ARCTIC AIR
PUSHES SOUTH INTO OUR REGION. IN MOST CASES MOS SEEMS TO TO
HANDLING THIS OK AND ONLY MINOR TWEAKS MADE.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY NIGHT/...
ISSUED AT 352 AM EST SUN DEC 28 2014
THE MAIN FOCUS OF THE LONG TERM PERIOD CONTINUES TO BE A LOW
PRESSURE SYSTEM LATE IN THE PERIOD. FIRST...ZONAL FLOW ALOFT WILL
RESULT IN DRY CONDITIONS FROM WEDNESDAY THROUGH THURSDAY. FOCUS
THEN TURNS TO THE APPROACHING LOW PRESSURE SYSTEM FROM THE
SOUTHWEST. MOST RECENT MODEL RUNS ARE SHOWING BETTER CONSISTENCY IN
THE TRACK COMPARED TO YESTERDAY. NOW THE GFS AND EURO ARE BOTH ON
BOARD WITH THE LOW PRESSURE SYSTEM TRACKING FROM THE DESERT
SOUTHWEST...ACROSS THE CENTRAL PLAINS...AND UP INTO CENTRAL
INDIANA. LATEST INITIALIZATION WAS A TAD FAST WITH BRINGING PRECIP
INTO SOUTHERN PORTIONS OF THE FORECAST AREA AS EARLY AS THURSDAY
NIGHT. NONE OF THE MODELS SEEM TO BE TRENDING THAT FAST...SO
REMOVED MENTION OF ANY PRECIP FOR THURSDAY NIGHT.
PRECIP CHANCES WILL INCREASE QUICKLY BY FRIDAY AFTERNOON AS LOW
PRESSURE SYSTEM TRAVERSES THE MISSOURI VALLEY. THE LIKELY POPS ON
FRIDAY NIGHT THAT REGIONAL INITIALIZATION IS TRENDING TOWARD MATCH
NICELY. SO...WILL NOT MAKE ANY DEVIATIONS TO POPS FOR FRIDAY AND
SATURDAY. CONFIDENCE IN PRECIP TYPE IS STILL LOW UNTIL THE EXACT
TRACK BECOMES SOLIDIFIED...BUT IT/S LOOKING LIKE SNOW OVER THE
NORTHERN THIRD OF THE FORECAST AREA WITH RAIN/SNOW AND RAIN OVER THE
REMAINING TWO-THIRDS OF CENTRAL INDIANA.
&&
.AVIATION /DISCUSSION FOR THE 281200Z TAF ISSUANCE/...
ISSUED AT 920 AM EST SUN DEC 28 2014
1420Z UPDATE...NO CHANGES NEEDED AT THIS TIME. PREVIOUS DISCUSSION
FOLLOWS.
RESIDUAL CLOUD COVER WILL LINGER ACROSS TAF SITES FOR MOST OF
TODAY. MVFR CONDITIONS WILL BE THE PREVAILING FLIGHT CATEGORY
THROUGH THE REMAINDER OF THIS MORNING...THEN IMPROVING TO VFR
CATEGORY BY EARLY AFTERNOON AS CEILINGS RISE. AS HIGH PRESSURE
STRENGTHENS OVER THE AREA...CLOUDS WILL SCATTER OUT FURTHER LATE
IN TAF PERIOD AND REMAIN AT VFR CATEGORY. WINDS WILL BE NORTHERLY
AT 2 TO 6 KTS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JH
NEAR TERM...JH
SHORT TERM...JH
LONG TERM....TDUD
AVIATION...SMF/TDUD
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSINDIANAPOLIS
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AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
631 AM EST SUN DEC 28 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 335 AM EST SUN DEC 28 2014
A COLD FRONT ACROSS OHIO AND NORTHWEST KENTUCKY WILL CONTINUE MOVING
SOUTHEAST. THIS WILL BE FOLLOWED BY A RIDGE OF HIGH PRESSURE WHICH
WILL MOVE SUNDAY NIGHT AND MONDAY. A DRY SECONDARY ARCTIC COLD
FRONT WILL MOVE SOUTHEAST ACROSS OUR REGION AROUND TUESDAY. IN THE
LONG TERM AN ARCTIC HIGH PRESSURE SYSTEM WILL BRING DRY AND COLD
WEATHER. HOWEVER MIXED PRECIPITATION IS POSSIBLE AGAIN THIS FRIDAY
THROUGH NEXT SATURDAY AS MODELS SHOW A LOW PRESSURE SYSTEM MOVING
INTO THE LOWER MISSISSIPPI VALLEY FRIDAY AND ACROSS OUR REGION
SATURDAY.
&&
.NEAR TERM /TODAY AND TONIGHT/...
ISSUED AT 335 AM EST SUN DEC 28 2014
RADAR SHOWS PRECIPITATION WAS ENDING RAPIDLY FROM THE NORTHWEST AND
WILL PRETTY MUCH BE DONE BY FORECAST RELEASE TIME. SOME SITES ACROSS
OUR SOUTH AND SOUTHEAST MAY SEE A LITTLE DRIZZLE PRIOR TO 7AM.
MAIN ISSUES TODAY WILL BE HOW LONG CLOUDS WILL REMAIN AND
TEMPERATURES. SATELLITE SHOWS CLEARING LINE ACROSS NORTHWEST
ILLINOIS. ALTHOUGH THERE HAVE BEEN A FEW HOLES FARTHER SOUTHEAST.
THE RAP MODEL SOUNDINGS INDICATE MOSTLY CLOUDY SKIES THIS MORNING
AND DECREASING CLOUDS FROM MIDDAY ON. EXPECT CLOUDS TO PERSIST OVER
SOUTHERN SECTIONS MOST OF TODAY AS THIS WILL BE LAST AREA TO CLEAR
OUT. HIGH TEMPERATURES TODAY WILL RANGE FROM THE MIDDLE 30S NORTH TO
AROUND 40 FAR SOUTH WHICH IS SLIGHTLY BELOW A MOS BLEND ON
TEMPERATURES.
TONIGHT WILL BECOME MOSTLY CLEAR AS WEAK RIDGE OF HIGH PRESSURE
MOVES INTO OUR REGION. WENT CLOSE TO A MOS BLEND ON TEMPERATURES
WITH LOWS IN THE LOWER 20S OVER NORTHERN SECTIONS AND THE MIDDLE AND
UPPER 20S SOUTH.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
ISSUED AT 335 AM EST SUN DEC 28 2014
MONDAY WILL BE SEASONABLY COOL WITH WEAK COLD ADVECTION AND HIGH
PRESSURE BUILDING IN FROM THE NORTHWEST. LOW LEVEL THICKNESS
INDICATE HIGHS SHOULD BE FROM THE MIDDLE 30S OVER NORTHERN SECTIONS
TO AROUND 40 FAR SOUTH WITH MOSTLY SUNNY SKIES.
MODELS INDICATE A WEAK UPPER DISTURBANCE WILL TRACK ACROSS INDIANA
LATE MONDAY NIGHT AS A SECONDARY ARCTIC COLD FRONT MOVES OUR WAY.
THE NAM SHOWS SOME QPF ACROSS OUR NORTHWEST LATE MONDAY NIGHT WHILE
ALL OTHER MODELS ARE DRY. ALL MODELS INDICATE SOME CLOUDS WITH THIS
FEATURE WILL MOVE INTO OUR NORTH LATE MONDAY NIGHT. AS A COMPROMISE
WILL MENTION A CHANCE OF FLURRIES NORTHWEST SECTIONS LATE MONDAY
NIGHT. OTHERWISE...IT SHOULD REMAIN DRY.
THIS SYSTEM WILL QUICKLY MOVE ON TO THE EAST TUESDAY. 850 MB
TEMPERATURES WHICH WILL BE AROUND -5 TO -8 MONDAY WILL COOL TO -10
TO -13 CELSIUS TUESDAY. THUS SURFACE TEMPERATURES WILL BE A LITTLE
COLDER TUESDAY AND EVEN COLDER ON WEDNESDAY AS MORE ARCTIC AIR
PUSHES SOUTH INTO OUR REGION. IN MOST CASES MOS SEEMS TO TO
HANDLING THIS OK AND ONLY MINOR TWEAKS MADE.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY NIGHT/...
ISSUED AT 352 AM EST SUN DEC 28 2014
THE MAIN FOCUS OF THE LONG TERM PERIOD CONTINUES TO BE A LOW
PRESSURE SYSTEM LATE IN THE PERIOD. FIRST...ZONAL FLOW ALOFT WILL
RESULT IN DRY CONDITIONS FROM WEDNESDAY THROUGH THURSDAY. FOCUS
THEN TURNS TO THE APPROACHING LOW PRESSURE SYSTEM FROM THE
SOUTHWEST. MOST RECENT MODEL RUNS ARE SHOWING BETTER CONSISTENCY IN
THE TRACK COMPARED TO YESTERDAY. NOW THE GFS AND EURO ARE BOTH ON
BOARD WITH THE LOW PRESSURE SYSTEM TRACKING FROM THE DESERT
SOUTHWEST...ACROSS THE CENTRAL PLAINS...AND UP INTO CENTRAL
INDIANA. LATEST INITIALIZATION WAS A TAD FAST WITH BRINGING PRECIP
INTO SOUTHERN PORTIONS OF THE FORECAST AREA AS EARLY AS THURSDAY
NIGHT. NONE OF THE MODELS SEEM TO BE TRENDING THAT FAST...SO
REMOVED MENTION OF ANY PRECIP FOR THURSDAY NIGHT.
PRECIP CHANCES WILL INCREASE QUICKLY BY FRIDAY AFTERNOON AS LOW
PRESSURE SYSTEM TRAVERSES THE MISSOURI VALLEY. THE LIKELY POPS ON
FRIDAY NIGHT THAT REGIONAL INITIALIZATION IS TRENDING TOWARD MATCH
NICELY. SO...WILL NOT MAKE ANY DEVIATIONS TO POPS FOR FRIDAY AND
SATURDAY. CONFIDENCE IN PRECIP TYPE IS STILL LOW UNTIL THE EXACT
TRACK BECOMES SOLIDIFIED...BUT IT/S LOOKING LIKE SNOW OVER THE
NORTHERN THIRD OF THE FORECAST AREA WITH RAIN/SNOW AND RAIN OVER THE
REMAINING TWO-THIRDS OF CENTRAL INDIANA.
&&
.AVIATION /DISCUSSION FOR THE 28/1200Z TAF ISSUANCE/...
ISSUED AT 624 AM EST SUN DEC 28 2014
RESIDUAL CLOUD COVER WILL LINGER ACROSS TAF SITES FOR MOST OF
TODAY. MVFR CONDITIONS WILL BE THE PREVAILING FLIGHT CATEGORY
THROUGH THE REMAINDER OF THIS MORNING...THEN IMPROVING TO VFR
CATEGORY BY EARLY AFTERNOON AS CEILINGS RISE. AS HIGH PRESSURE
STRENGTHENS OVER THE AREA...CLOUDS WILL SCATTER OUT FURTHER LATE
IN TAF PERIOD AND REMAIN AT VFR CATEGORY. WINDS WILL BE NORTHERLY
AT 2 TO 6 KTS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...JH
NEAR TERM...JH
SHORT TERM...JH
LONG TERM....TDUD
AVIATION...TDUD
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
353 AM EST SUN DEC 28 2014
.UPDATE...
THE LONG TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 335 AM EST SUN DEC 28 2014
A COLD FRONT ACROSS OHIO AND NORTHWEST KENTUCKY WILL CONTINUE MOVING
SOUTHEAST. THIS WILL BE FOLLOWED BY A RIDGE OF HIGH PRESSURE WHICH
WILL MOVE SUNDAY NIGHT AND MONDAY. A DRY SECONDARY ARCTIC COLD
FRONT WILL MOVE SOUTHEAST ACROSS OUR REGION AROUND TUESDAY. IN THE
LONG TERM AN ARCTIC HIGH PRESSURE SYSTEM WILL BRING DRY AND COLD
WEATHER. HOWEVER MIXED PRECIPITATION IS POSSIBLE AGAIN THIS FRIDAY
THROUGH NEXT SATURDAY AS MODELS SHOW A LOW PRESSURE SYSTEM MOVING
INTO THE LOWER MISSISSIPPI VALLEY FRIDAY AND ACROSS OUR REGION
SATURDAY.
&&
.NEAR TERM /TODAY AND TONIGHT/...
ISSUED AT 335 AM EST SUN DEC 28 2014
RADAR SHOWS PRECIPITATION WAS ENDING RAPIDLY FROM THE NORTHWEST AND
WILL PRETTY MUCH BE DONE BY FORECAST RELEASE TIME. SOME SITES ACROSS
OUR SOUTH AND SOUTHEAST MAY SEE A LITTLE DRIZZLE PRIOR TO 7AM.
MAIN ISSUES TODAY WILL BE HOW LONG CLOUDS WILL REMAIN AND
TEMPERATURES. SATELLITE SHOWS CLEARING LINE ACROSS NORTHWEST
ILLINOIS. ALTHOUGH THERE HAVE BEEN A FEW HOLES FARTHER SOUTHEAST.
THE RAP MODEL SOUNDINGS INDICATE MOSTLY CLOUDY SKIES THIS MORNING
AND DECREASING CLOUDS FROM MIDDAY ON. EXPECT CLOUDS TO PERSIST OVER
SOUTHERN SECTIONS MOST OF TODAY AS THIS WILL BE LAST AREA TO CLEAR
OUT. HIGH TEMPERATURES TODAY WILL RANGE FROM THE MIDDLE 30S NORTH TO
AROUND 40 FAR SOUTH WHICH IS SLIGHTLY BELOW A MOS BLEND ON
TEMPERATURES.
TONIGHT WILL BECOME MOSTLY CLEAR AS WEAK RIDGE OF HIGH PRESSURE
MOVES INTO OUR REGION. WENT CLOSE TO A MOS BLEND ON TEMPERATURES
WITH LOWS IN THE LOWER 20S OVER NORTHERN SECTIONS AND THE MIDDLE AND
UPPER 20S SOUTH.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
ISSUED AT 335 AM EST SUN DEC 28 2014
MONDAY WILL BE SEASONABLY COOL WITH WEAK COLD ADVECTION AND HIGH
PRESSURE BUILDING IN FROM THE NORTHWEST. LOW LEVEL THICKNESS
INDICATE HIGHS SHOULD BE FROM THE MIDDLE 30S OVER NORTHERN SECTIONS
TO AROUND 40 FAR SOUTH WITH MOSTLY SUNNY SKIES.
MODELS INDICATE A WEAK UPPER DISTURBANCE WILL TRACK ACROSS INDIANA
LATE MONDAY NIGHT AS A SECONDARY ARCTIC COLD FRONT MOVES OUR WAY.
THE NAM SHOWS SOME QPF ACROSS OUR NORTHWEST LATE MONDAY NIGHT WHILE
ALL OTHER MODELS ARE DRY. ALL MODELS INDICATE SOME CLOUDS WITH THIS
FEATURE WILL MOVE INTO OUR NORTH LATE MONDAY NIGHT. AS A COMPROMISE
WILL MENTION A CHANCE OF FLURRIES NORTHWEST SECTIONS LATE MONDAY
NIGHT. OTHERWISE...IT SHOULD REMAIN DRY.
THIS SYSTEM WILL QUICKLY MOVE ON TO THE EAST TUESDAY. 850 MB
TEMPERATURES WHICH WILL BE AROUND -5 TO -8 MONDAY WILL COOL TO -10
TO -13 CELSIUS TUESDAY. THUS SURFACE TEMPERATURES WILL BE A LITTLE
COLDER TUESDAY AND EVEN COLDER ON WEDNESDAY AS MORE ARCTIC AIR
PUSHES SOUTH INTO OUR REGION. IN MOST CASES MOS SEEMS TO TO
HANDLING THIS OK AND ONLY MINOR TWEAKS MADE.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY NIGHT/...
ISSUED AT 352 AM EST SUN DEC 28 2014
THE MAIN FOCUS OF THE LONG TERM PERIOD CONTINUES TO BE A LOW
PRESSURE SYSTEM LATE IN THE PERIOD. FIRST...ZONAL FLOW ALOFT WILL
RESULT IN DRY CONDITIONS FROM WEDNESDAY THROUGH THURSDAY. FOCUS
THEN TURNS TO THE APPROACHING LOW PRESSURE SYSTEM FROM THE
SOUTHWEST. MOST RECENT MODEL RUNS ARE SHOWING BETTER CONSISTENCY IN
THE TRACK COMPARED TO YESTERDAY. NOW THE GFS AND EURO ARE BOTH ON
BOARD WITH THE LOW PRESSURE SYSTEM TRACKING FROM THE DESERT
SOUTHWEST...ACROSS THE CENTRAL PLAINS...AND UP INTO CENTRAL
INDIANA. LATEST INITIALIZATION WAS A TAD FAST WITH BRINGING PRECIP
INTO SOUTHERN PORTIONS OF THE FORECAST AREA AS EARLY AS THURSDAY
NIGHT. NONE OF THE MODELS SEEM TO BE TRENDING THAT FAST...SO
REMOVED MENTION OF ANY PRECIP FOR THURSDAY NIGHT.
PRECIP CHANCES WILL INCREASE QUICKLY BY FRIDAY AFTERNOON AS LOW
PRESSURE SYSTEM TRAVERSES THE MISSOURI VALLEY. THE LIKELY POPS ON
FRIDAY NIGHT THAT REGIONAL INITIALIZATION IS TRENDING TOWARD MATCH
NICELY. SO...WILL NOT MAKE ANY DEVIATIONS TO POPS FOR FRIDAY AND
SATURDAY. CONFIDENCE IN PRECIP TYPE IS STILL LOW UNTIL THE EXACT
TRACK BECOMES SOLIDIFIED...BUT IT/S LOOKING LIKE SNOW OVER THE
NORTHERN THIRD OF THE FORECAST AREA WITH RAIN/SNOW AND RAIN OVER THE
REMAINING TWO-THIRDS OF CENTRAL INDIANA.
&&
.AVIATION /DISCUSSION FOR THE 28/0900Z TAF UPDATE/...
ISSUED AT 324 AM EST SUN DEC 28 2014
UPDATE...
MVFR CONDITIONS ARE PREVAILING AT KIND AND WILL CONTINUE THROUGH
THE MORNING.
PREVIOUS DISCUSSION...
WINDS TO REMAIN BELOW 10 KNOTS THROUGH THE FORECAST.
RAIN HAS ENDED AT ALL TAF SITES EXCEPT KBMG BUT SHOULD ALSO END
THERE WITHIN THE HOUR OR AROUND 280700Z.
WITHIN COLD AND DRY AIR ADVECTING IN...VISIBILITY HAS IMPROVED TO 6+
MILES AND WILL REMAIN THAT WAY THROUGH THE FORECAST.
MULTIPLE CLOUD LAYERS HAVE BEEN OBSERVED ACROSS ILLINOIS BUT SEEM TO
BE SETTLING TOWARDS DECKS OF 1800-2200 FEET AND THESE SHOULD PREVAIL
THROUGH THE MORNING. AS HIGH PRESSURE CONTINUES BUILDING IN AND
SUBSIDENCE BEGINS TO DRY THIS LOWER LAYER EXPECT BREAKS IN THE 2000
FOOT DECK AROUND 281800Z AND EVENTUAL CLEARING OF ALL CLOUDS BY
290000Z.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...JH
NEAR TERM...JH
SHORT TERM...JH
LONG TERM....TDUD
AVIATION...DT/TDUD
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
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WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
335 AM EST SUN DEC 28 2014
.UPDATE...
SYNOPSIS...NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN UPDATED
BELOW.
&&
.SYNOPSIS...
ISSUED AT 335 AM EST SUN DEC 28 2014
A COLD FRONT ACROSS OHIO AND NORTHWEST KENTUCKY WILL CONTINUE MOVING
SOUTHEAST. THIS WILL BE FOLLOWED BY A RIDGE OF HIGH PRESSURE WHICH
WILL MOVE SUNDAY NIGHT AND MONDAY. A DRY SECONDARY ARCTIC COLD
FRONT WILL MOVE SOUTHEAST ACROSS OUR REGION AROUND TUESDAY. IN THE
LONG TERM AN ARCTIC HIGH PRESSURE SYSTEM WILL BRING DRY AND COLD
WEATHER. HOWEVER MIXED PRECIPITATION IS POSSIBLE AGAIN THIS FRIDAY
THROUGH NEXT SATURDAY AS MODELS SHOW A LOW PRESSURE SYSTEM MOVING
INTO THE LOWER MISSISSIPPI VALLEY FRIDAY AND ACROSS OUR REGION
SATURDAY.
&&
.NEAR TERM /TODAY AND TONIGHT/...
ISSUED AT 335 AM EST SUN DEC 28 2014
RADAR SHOWS PRECIPITATION WAS ENDING RAPIDLY FROM THE NORTHWEST AND
WILL PRETTY MUCH BE DONE BY FORECAST RELEASE TIME. SOME SITES ACROSS
OUR SOUTH AND SOUTHEAST MAY SEE A LITTLE DRIZZLE PRIOR TO 7AM.
MAIN ISSUES TODAY WILL BE HOW LONG CLOUDS WILL REMAIN AND
TEMPERATURES. SATELLITE SHOWS CLEARING LINE ACROSS NORTHWEST
ILLINOIS. ALTHOUGH THERE HAVE BEEN A FEW HOLES FARTHER SOUTHEAST.
THE RAP MODEL SOUNDINGS INDICATE MOSTLY CLOUDY SKIES THIS MORNING
AND DECREASING CLOUDS FROM MIDDAY ON. EXPECT CLOUDS TO PERSIST OVER
SOUTHERN SECTIONS MOST OF TODAY AS THIS WILL BE LAST AREA TO CLEAR
OUT. HIGH TEMPERATURES TODAY WILL RANGE FROM THE MIDDLE 30S NORTH TO
AROUND 40 FAR SOUTH WHICH IS SLIGHTLY BELOW A MOS BLEND ON
TEMPERATURES.
TONIGHT WILL BECOME MOSTLY CLEAR AS WEAK RIDGE OF HIGH PRESSURE
MOVES INTO OUR REGION. WENT CLOSE TO A MOS BLEND ON TEMPERATURES
WITH LOWS IN THE LOWER 20S OVER NORTHERN SECTIONS AND THE MIDDLE AND
UPPER 20S SOUTH.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
ISSUED AT 335 AM EST SUN DEC 28 2014
MONDAY WILL BE SEASONABLY COOL WITH WEAK COLD ADVECTION AND HIGH
PRESSURE BUILDING IN FROM THE NORTHWEST. LOW LEVEL THICKNESS
INDICATE HIGHS SHOULD BE FROM THE MIDDLE 30S OVER NORTHERN SECTIONS
TO AROUND 40 FAR SOUTH WITH MOSTLY SUNNY SKIES.
MODELS INDICATE A WEAK UPPER DISTURBANCE WILL TRACK ACROSS INDIANA
LATE MONDAY NIGHT AS A SECONDARY ARCTIC COLD FRONT MOVES OUR WAY.
THE NAM SHOWS SOME QPF ACROSS OUR NORTHWEST LATE MONDAY NIGHT WHILE
ALL OTHER MODELS ARE DRY. ALL MODELS INDICATE SOME CLOUDS WITH THIS
FEATURE WILL MOVE INTO OUR NORTH LATE MONDAY NIGHT. AS A COMPROMISE
WILL MENTION A CHANCE OF FLURRIES NORTHWEST SECTIONS LATE MONDAY
NIGHT. OTHERWISE...IT SHOULD REMAIN DRY.
THIS SYSTEM WILL QUICKLY MOVE ON TO THE EAST TUESDAY. 850 MB
TEMPERATURES WHICH WILL BE AROUND -5 TO -8 MONDAY WILL COOL TO -10
TO -13 CELSIUS TUESDAY. THUS SURFACE TEMPERATURES WILL BE A LITTLE
COLDER TUESDAY AND EVEN COLDER ON WEDNESDAY AS MORE ARCTIC AIR
PUSHES SOUTH INTO OUR REGION. IN MOST CASES MOS SEEMS TO TO
HANDLING THIS OK AND ONLY MINOR TWEAKS MADE.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
ISSUED AT 240 PM EST SAT DEC 27 2014
MAIN FOCUS FOR THE EXTENDED PERIOD WILL BE POPS AND PRECIPITATION
TYPE STARTING FRIDAY. PRIOR TO THAT...TEMPERATURES WILL BE THE
BIGGEST ISSUE AS STRONG COLD WESTERN CANADIAN HIGH PRESSURE WILL
SETTLE ACROSS THE OHIO VALLEY TO END THE OLD YEAR AND START THE NEW
ONE.
DETERMINISTIC MODELS ARE IN DECENT AGREEMENT THAT AN UPPER LOW WILL
BE OVER NORTHEASTERN ARIZONA DURING THE EVENING OF THE FIRST DAY OF
2015. HOWEVER...THE MODELS THEN DIVERGE RAPIDLY WITH THE MUCH
QUICKER 12Z GFS BRINGING A STRONGER SURFACE SYSTEM BUT WEAK UPPER
WAVE OVER THE OHIO VALLEY FRIDAY NIGHT. MEANWHILE...THE 12Z ECMWF
HAS EVEN A WEAKER BUT MUCH SLOWER WAVE LIFT NORTHEAST TO SOUTHERN
ILLINOIS BY NEXT SATURDAY EVENING. THE EURO ALSO HAS THE MAIN
SURFACE LOW WELL SOUTHWEST OF THE 12Z GFS POSITION SATURDAY EVENING.
THE ECMWF HAS THE SURFACE LOW OVER EASTERN KENTUCKY...WHILE THE GFS
HAS IT OVER SOUTHERN QUEBEC. DESPITE ALL THESE DIFFERENCES...BOTH
MODELS START THE QPF ON FRIDAY WITH THE HEAVIEST PRECIPITATION ALONG
THE OHIO RIVER. MEANWHILE...THE EURO WAS HOLDING MORE QPF AROUND ON
SUNDAY THAN THE GFS. SO...STILL EXPECT THE PRECIPITATION TO SPREAD
NORTHEAST ACROSS THE AREA ON FRIDAY. WITH CONFIDENCE IN TIMING
LOW...WILL ACCEPT THE REGIONAL BLEND THAT KEEPS DECENT POPS AROUND
NEXT SATURDAY AS HINTED AT BY THE EURO.
REGARDING PRECIPITATION TYPE...WILL NOT MAKE MANY CHANGES WITH THE
MODEL DIFFERENCES. CONFIDENCE NOT GOOD AS TO WHERE THE RAIN/SNOW
LINE WILL BE IN SPACE AND TIME. HOWEVER...NORTHEASTERN PARTS OF THE
FORECAST AREA WILL BE MORE LIKELY TO SEE FROZEN OR MIXED
PRECIPITATION THEN THE SOUTHWESTERN ONES ON FRIDAY BASED ON
THERMAL PROFILES FROM BUFKIT SOUNDINGS AS WELL AS PARTIAL
THICKNESSES. FRIDAY NIGHT AND SATURDAY...THE NORTHWESTERN COUNTIES
WOULD HAVE A HIGHER CHANCE OF MIXED OR FROZEN PRECIPITATION THAN THE
SOUTHEAST AS COLDER AIR MOVES IN FROM THE NORTHWEST IN THE WAKE OF
THE SURFACE SYSTEM. BUFKIT SOUNDINGS EVEN SUGGEST FREEZING RAIN OR
SLEET COULD POSSIBLY MIX IN AT TIMES FRIDAY NIGHT.
GENERALLY ACCEPTED THE REGIONAL BLEND TEMPERATURES. DO NOT FEEL
CONFIDENT ENOUGH TO MAKE CHANGES UNTIL THE MODELS HOPEFULLY COME
CLOSER TOGETHER IN SUBSEQUENT RUNS. AFTERNOON HIGHS IN THE 20S LOOK
GOOD ON NEW YEAR`S DAY WITH HIGHS MOSTLY IN THE 30S THEREAFTER.
MEANWHILE...NEW YEARS EVE NIGHT SHOULD BE THE COLDEST WITH OVERNIGHT
LOWS IN THE TEENS FOR THE FIRST SUNRISE OF THE YEAR. OVERNIGHT LOWS
WILL MOSTLY BE IN THE 20S AND 30S BY LATE WEEK.
&&
.AVIATION /DISCUSSION FOR THE 28/0900Z TAF UPDATE/...
ISSUED AT 324 AM EST SUN DEC 28 2014
UPDATE...
MVFR CONDITIONS ARE PREVAILING AT KIND AND WILL CONTINUE THROUGH
THE MORNING.
PREVIOUS DISCUSSION...
WINDS TO REMAIN BELOW 10 KNOTS THROUGH THE FORECAST.
RAIN HAS ENDED AT ALL TAF SITES EXCEPT KBMG BUT SHOULD ALSO END
THERE WITHIN THE HOUR OR AROUND 280700Z.
WITHIN COLD AND DRY AIR ADVECTING IN...VISIBILITY HAS IMPROVED TO 6+
MILES AND WILL REMAIN THAT WAY THROUGH THE FORECAST.
MULTIPLE CLOUD LAYERS HAVE BEEN OBSERVED ACROSS ILLINOIS BUT SEEM TO
BE SETTLING TOWARDS DECKS OF 1800-2200 FEET AND THESE SHOULD PREVAIL
THROUGH THE MORNING. AS HIGH PRESSURE CONTINUES BUILDING IN AND
SUBSIDENCE BEGINS TO DRY THIS LOWER LAYER EXPECT BREAKS IN THE 2000
FOOT DECK AROUND 281800Z AND EVENTUAL CLEARING OF ALL CLOUDS BY
290000Z.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...JH
NEAR TERM...JH
SHORT TERM...JH
LONG TERM...MK
AVIATION...DT/TDUD
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
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AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
329 AM EST SUN DEC 28 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 324 PM EST SAT DEC 27 2014
A COLD FRONT WILL MOVE EAST ACROSS OUR REGION TONIGHT. A DRY
SECONDARY ARCTIC COLD FRONT WILL MOVE SOUTHEAST ACROSS OUR REGION
AROUND TUESDAY. IN THE LONG TERM AN ARCTIC HIGH PRESSURE SYSTEM WILL
BRING DRY AND COLD WEATHER. HOWEVER MIXED PRECIPITATION IS POSSIBLE
AGAIN THIS FRIDAY THROUGH NEXT SATURDAY AS MODELS SHOW A LOW
PRESSURE SYSTEM MOVING INTO THE LOWER MISSISSIPPI VALLEY.
&&
.NEAR TERM /TONIGHT/...
ISSUED AT 845 PM EST SAT DEC 27 2014
UPDATED TO REFLECT LATEST PROGRESSION OF BAND OF PRECIP INTO THE
NORTHWESTERN FORECAST AREA AND ACROSS THE AREA THIS EVENING INTO
THE OVERNIGHT. EXPECT THERE WILL BE PERIODS OF RAIN AND
SNOW...PERIODS OF EITHER...AND PERHAPS SOME SLEET AS WELL IN MOST
AREAS...BUT WITH LITTLE OR NO ACCUMULATION AS TEMPERATURES REMAIN
ABOVE FREEZING AND MAY DO SO FOR SEVERAL MORE HOURS IF NOT ALL
NIGHT ACROSS SOME PORTIONS OF THE AREA. HAVE ALSO SPED UP ENDING
OF PRECIP A BIT BASED ON LATEST MODEL GUIDANCE. PREVIOUS
DISCUSSION FOLLOWS.
ISSUED AT 324 PM EST SAT DEC 27 2014
TRENDS AMONG THE MODELS REMAIN VIRTUALLY THE SAME...WITH THE EURO
AND NAM BEING MUCH MORE PROGRESSIVE THAN THE GFS AND GEM. AS
USUAL...THE SREF AND HRRR TAKE A DECENT BLEND OF THE FASTER AND
SLOWER SOLUTIONS...SO LEANED HEAVILY TOWARD THIS GUIDANCE WHEN
CREATING THE POPS FOR TONIGHT. ALSO TRIED TO WORK IN WHAT IS
CURRENTLY ON THE RADAR SCOPE WITH ONE WAVE OF LIGHT RAIN MOVING IN
FROM THE SOUTH...WHICH WILL LATER THE EXIT THE FORECAST AREA BY
00Z. WHILE THE MAIN AREA OF PRECIPITATION IS BEGINNING TO APPROACH
THE CENTRAL INDIANA AREA FROM CENTRAL ILLINOIS. THIS AREA WILL
MAKE IT/S WAY THROUGH THE BULK OF CENTRAL INDIANA FROM 00Z TO 08Z.
WITH A FEW COUNTIES TO THE SOUTHEAST COUNTIES SEEING SOME
LINGERING POPS INTO EARLY SUNDAY MORNING.
ATTENTION THEN TURNS TO PRECIP TYPE AND TIMING...BOTH OF WHICH
WILL BE TRICKY. ALL OF THE PRECIP OVER CENTRAL INDIANA WILL BE IN
THE FORM OF RAIN THROUGH THIS EVENING. COLDER AIR WILL BEGIN
WORKING INTO THE NORTHWEST COUNTIES OF THE CWA ABOUT MIDNIGHT AND
PUSH TOWARD THE I-70 CORRIDOR BY 2-3 AM. BEST CHANCE IN TERMS OF
PRECIP TYPE ARE STILL A -RA/SN MIX...CANNOT RULE OUT ANY SLEET
MIXING IN AT TIMES HOWEVER NOT WIDESPREAD ENOUGH TO HAVE THE
CONFIDENCE TO INCLUDE IT IN FORECAST AT THIS TIME. THIS MIX WILL
WORK IT/S WAY TOWARD THE E/SE EARLY SUNDAY MORNING...WHILE PRECIP
BEHIND IT BEGINS TO WIND DOWN AND DRY OUT OVER MOST OF THE
FORECAST AREA BY 12Z SUNDAY MORNING. LOWS 31-36.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
ISSUED AT 324 PM EST SAT DEC 27 2014
AS MENTIONED IN ABOVE DISCUSSION...THERE WILL LIKELY BE SOME REMNANT
MIXTURE OF -RA/SN FOR EARLY SUNDAY MORNING ACROSS SEVERAL OF THE
SOUTHEASTERN COUNTIES BEFORE THAT FRONT MOVES FARTHER FROM THE AREA
AND DRIER AND COLDER AIR FILTERS BACK INTO THE AREA. WILL CONTINUE
LOW CHANCE POPS THERE AT LEAST THROUGH 14-15Z SUNDAY MORNING.
DRY AND COOLER WEATHER WILL PERSIST ACROSS THE REGION FOR THE BETTER
HALF OF THE NEXT WEEK AS A LARGE AREA OF HIGH PRESSURE REMAINS IN
CONTROL OVER THE REGION. MODELS INDICATE HIGHS IN THE UPPER 30S
SUNDAY AND PERHAPS A DEGREE OR TWO WARMER MONDAY. LOWS WILL BE IN
THE MIDDLE TO UPPER 20S SUNDAY NIGHT AND LOWER OR MIDDLE 20S MONDAY
NIGHT AS A DRY SECONDARY COLD FRONT MOVES THROUGH.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
ISSUED AT 240 PM EST SAT DEC 27 2014
MAIN FOCUS FOR THE EXTENDED PERIOD WILL BE POPS AND PRECIPITATION
TYPE STARTING FRIDAY. PRIOR TO THAT...TEMPERATURES WILL BE THE
BIGGEST ISSUE AS STRONG COLD WESTERN CANADIAN HIGH PRESSURE WILL
SETTLE ACROSS THE OHIO VALLEY TO END THE OLD YEAR AND START THE NEW
ONE.
DETERMINISTIC MODELS ARE IN DECENT AGREEMENT THAT AN UPPER LOW WILL
BE OVER NORTHEASTERN ARIZONA DURING THE EVENING OF THE FIRST DAY OF
2015. HOWEVER...THE MODELS THEN DIVERGE RAPIDLY WITH THE MUCH
QUICKER 12Z GFS BRINGING A STRONGER SURFACE SYSTEM BUT WEAK UPPER
WAVE OVER THE OHIO VALLEY FRIDAY NIGHT. MEANWHILE...THE 12Z ECMWF
HAS EVEN A WEAKER BUT MUCH SLOWER WAVE LIFT NORTHEAST TO SOUTHERN
ILLINOIS BY NEXT SATURDAY EVENING. THE EURO ALSO HAS THE MAIN
SURFACE LOW WELL SOUTHWEST OF THE 12Z GFS POSITION SATURDAY EVENING.
THE ECMWF HAS THE SURFACE LOW OVER EASTERN KENTUCKY...WHILE THE GFS
HAS IT OVER SOUTHERN QUEBEC. DESPITE ALL THESE DIFFERENCES...BOTH
MODELS START THE QPF ON FRIDAY WITH THE HEAVIEST PRECIPITATION ALONG
THE OHIO RIVER. MEANWHILE...THE EURO WAS HOLDING MORE QPF AROUND ON
SUNDAY THAN THE GFS. SO...STILL EXPECT THE PRECIPITATION TO SPREAD
NORTHEAST ACROSS THE AREA ON FRIDAY. WITH CONFIDENCE IN TIMING
LOW...WILL ACCEPT THE REGIONAL BLEND THAT KEEPS DECENT POPS AROUND
NEXT SATURDAY AS HINTED AT BY THE EURO.
REGARDING PRECIPITATION TYPE...WILL NOT MAKE MANY CHANGES WITH THE
MODEL DIFFERENCES. CONFIDENCE NOT GOOD AS TO WHERE THE RAIN/SNOW
LINE WILL BE IN SPACE AND TIME. HOWEVER...NORTHEASTERN PARTS OF THE
FORECAST AREA WILL BE MORE LIKELY TO SEE FROZEN OR MIXED
PRECIPITATION THEN THE SOUTHWESTERN ONES ON FRIDAY BASED ON
THERMAL PROFILES FROM BUFKIT SOUNDINGS AS WELL AS PARTIAL
THICKNESSES. FRIDAY NIGHT AND SATURDAY...THE NORTHWESTERN COUNTIES
WOULD HAVE A HIGHER CHANCE OF MIXED OR FROZEN PRECIPITATION THAN THE
SOUTHEAST AS COLDER AIR MOVES IN FROM THE NORTHWEST IN THE WAKE OF
THE SURFACE SYSTEM. BUFKIT SOUNDINGS EVEN SUGGEST FREEZING RAIN OR
SLEET COULD POSSIBLY MIX IN AT TIMES FRIDAY NIGHT.
GENERALLY ACCEPTED THE REGIONAL BLEND TEMPERATURES. DO NOT FEEL
CONFIDENT ENOUGH TO MAKE CHANGES UNTIL THE MODELS HOPEFULLY COME
CLOSER TOGETHER IN SUBSEQUENT RUNS. AFTERNOON HIGHS IN THE 20S LOOK
GOOD ON NEW YEAR`S DAY WITH HIGHS MOSTLY IN THE 30S THEREAFTER.
MEANWHILE...NEW YEARS EVE NIGHT SHOULD BE THE COLDEST WITH OVERNIGHT
LOWS IN THE TEENS FOR THE FIRST SUNRISE OF THE YEAR. OVERNIGHT LOWS
WILL MOSTLY BE IN THE 20S AND 30S BY LATE WEEK.
&&
.AVIATION /DISCUSSION FOR THE 28/0900Z TAF UPDATE/...
ISSUED AT 324 AM EST SUN DEC 28 2014
UPDATE...
MVFR CONDITIONS ARE PREVAILING AT KIND AND WILL CONTINUE THROUGH
THE MORNING.
PREVIOUS DISCUSSION...
WINDS TO REMAIN BELOW 10 KNOTS THROUGH THE FORECAST.
RAIN HAS ENDED AT ALL TAF SITES EXCEPT KBMG BUT SHOULD ALSO END THERE
WITHIN THE HOUR OR AROUND 280700Z.
WITHIN COLD AND DRY AIR ADVECTING IN...VISIBILITY HAS IMPROVED TO 6+
MILES AND WILL REMAIN THAT WAY THROUGH THE FORECAST.
MULTIPLE CLOUD LAYERS HAVE BEEN OBSERVED ACROSS ILLINOIS BUT SEEM TO
BE SETTLING TOWARDS DECKS OF 1800-2200 FEET AND THESE SHOULD PREVAIL
THROUGH THE MORNING. AS HIGH PRESSURE CONTINUES BUILDING IN AND
SUBSIDENCE BEGINS TO DRY THIS LOWER LAYER EXPECT BREAKS IN THE 2000
FOOT DECK AROUND 281800Z AND EVENTUAL CLEARING OF ALL CLOUDS BY
290000Z.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...SMF
NEAR TERM...SMF/NIELD
SHORT TERM...SMF
LONG TERM...MK
AVIATION...DT/TDUD
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1212 AM EST SUN DEC 28 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 324 PM EST SAT DEC 27 2014
A COLD FRONT WILL MOVE EAST ACROSS OUR REGION TONIGHT. A DRY
SECONDARY ARCTIC COLD FRONT WILL MOVE SOUTHEAST ACROSS OUR REGION
AROUND TUESDAY. IN THE LONG TERM AN ARCTIC HIGH PRESSURE SYSTEM WILL
BRING DRY AND COLD WEATHER. HOWEVER MIXED PRECIPITATION IS POSSIBLE
AGAIN THIS FRIDAY THROUGH NEXT SATURDAY AS MODELS SHOW A LOW
PRESSURE SYSTEM MOVING INTO THE LOWER MISSISSIPPI VALLEY.
&&
.NEAR TERM /TONIGHT/...
ISSUED AT 845 PM EST SAT DEC 27 2014
UPDATED TO REFLECT LATEST PROGRESSION OF BAND OF PRECIP INTO THE
NORTHWESTERN FORECAST AREA AND ACROSS THE AREA THIS EVENING INTO
THE OVERNIGHT. EXPECT THERE WILL BE PERIODS OF RAIN AND
SNOW...PERIODS OF EITHER...AND PERHAPS SOME SLEET AS WELL IN MOST
AREAS...BUT WITH LITTLE OR NO ACCUMULATION AS TEMPERATURES REMAIN
ABOVE FREEZING AND MAY DO SO FOR SEVERAL MORE HOURS IF NOT ALL
NIGHT ACROSS SOME PORTIONS OF THE AREA. HAVE ALSO SPED UP ENDING
OF PRECIP A BIT BASED ON LATEST MODEL GUIDANCE. PREVIOUS
DISCUSSION FOLLOWS.
ISSUED AT 324 PM EST SAT DEC 27 2014
TRENDS AMONG THE MODELS REMAIN VIRTUALLY THE SAME...WITH THE EURO
AND NAM BEING MUCH MORE PROGRESSIVE THAN THE GFS AND GEM. AS
USUAL...THE SREF AND HRRR TAKE A DECENT BLEND OF THE FASTER AND
SLOWER SOLUTIONS...SO LEANED HEAVILY TOWARD THIS GUIDANCE WHEN
CREATING THE POPS FOR TONIGHT. ALSO TRIED TO WORK IN WHAT IS
CURRENTLY ON THE RADAR SCOPE WITH ONE WAVE OF LIGHT RAIN MOVING IN
FROM THE SOUTH...WHICH WILL LATER THE EXIT THE FORECAST AREA BY
00Z. WHILE THE MAIN AREA OF PRECIPITATION IS BEGINNING TO APPROACH
THE CENTRAL INDIANA AREA FROM CENTRAL ILLINOIS. THIS AREA WILL
MAKE IT/S WAY THROUGH THE BULK OF CENTRAL INDIANA FROM 00Z TO 08Z.
WITH A FEW COUNTIES TO THE SOUTHEAST COUNTIES SEEING SOME
LINGERING POPS INTO EARLY SUNDAY MORNING.
ATTENTION THEN TURNS TO PRECIP TYPE AND TIMING...BOTH OF WHICH
WILL BE TRICKY. ALL OF THE PRECIP OVER CENTRAL INDIANA WILL BE IN
THE FORM OF RAIN THROUGH THIS EVENING. COLDER AIR WILL BEGIN
WORKING INTO THE NORTHWEST COUNTIES OF THE CWA ABOUT MIDNIGHT AND
PUSH TOWARD THE I-70 CORRIDOR BY 2-3 AM. BEST CHANCE IN TERMS OF
PRECIP TYPE ARE STILL A -RA/SN MIX...CANNOT RULE OUT ANY SLEET
MIXING IN AT TIMES HOWEVER NOT WIDESPREAD ENOUGH TO HAVE THE
CONFIDENCE TO INCLUDE IT IN FORECAST AT THIS TIME. THIS MIX WILL
WORK IT/S WAY TOWARD THE E/SE EARLY SUNDAY MORNING...WHILE PRECIP
BEHIND IT BEGINS TO WIND DOWN AND DRY OUT OVER MOST OF THE
FORECAST AREA BY 12Z SUNDAY MORNING. LOWS 31-36.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
ISSUED AT 324 PM EST SAT DEC 27 2014
AS MENTIONED IN ABOVE DISCUSSION...THERE WILL LIKELY BE SOME REMNANT
MIXTURE OF -RA/SN FOR EARLY SUNDAY MORNING ACROSS SEVERAL OF THE
SOUTHEASTERN COUNTIES BEFORE THAT FRONT MOVES FARTHER FROM THE AREA
AND DRIER AND COLDER AIR FILTERS BACK INTO THE AREA. WILL CONTINUE
LOW CHANCE POPS THERE AT LEAST THROUGH 14-15Z SUNDAY MORNING.
DRY AND COOLER WEATHER WILL PERSIST ACROSS THE REGION FOR THE BETTER
HALF OF THE NEXT WEEK AS A LARGE AREA OF HIGH PRESSURE REMAINS IN
CONTROL OVER THE REGION. MODELS INDICATE HIGHS IN THE UPPER 30S
SUNDAY AND PERHAPS A DEGREE OR TWO WARMER MONDAY. LOWS WILL BE IN
THE MIDDLE TO UPPER 20S SUNDAY NIGHT AND LOWER OR MIDDLE 20S MONDAY
NIGHT AS A DRY SECONDARY COLD FRONT MOVES THROUGH.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
ISSUED AT 240 PM EST SAT DEC 27 2014
MAIN FOCUS FOR THE EXTENDED PERIOD WILL BE POPS AND PRECIPITATION
TYPE STARTING FRIDAY. PRIOR TO THAT...TEMPERATURES WILL BE THE
BIGGEST ISSUE AS STRONG COLD WESTERN CANADIAN HIGH PRESSURE WILL
SETTLE ACROSS THE OHIO VALLEY TO END THE OLD YEAR AND START THE NEW
ONE.
DETERMINISTIC MODELS ARE IN DECENT AGREEMENT THAT AN UPPER LOW WILL
BE OVER NORTHEASTERN ARIZONA DURING THE EVENING OF THE FIRST DAY OF
2015. HOWEVER...THE MODELS THEN DIVERGE RAPIDLY WITH THE MUCH
QUICKER 12Z GFS BRINGING A STRONGER SURFACE SYSTEM BUT WEAK UPPER
WAVE OVER THE OHIO VALLEY FRIDAY NIGHT. MEANWHILE...THE 12Z ECMWF
HAS EVEN A WEAKER BUT MUCH SLOWER WAVE LIFT NORTHEAST TO SOUTHERN
ILLINOIS BY NEXT SATURDAY EVENING. THE EURO ALSO HAS THE MAIN
SURFACE LOW WELL SOUTHWEST OF THE 12Z GFS POSITION SATURDAY EVENING.
THE ECMWF HAS THE SURFACE LOW OVER EASTERN KENTUCKY...WHILE THE GFS
HAS IT OVER SOUTHERN QUEBEC. DESPITE ALL THESE DIFFERENCES...BOTH
MODELS START THE QPF ON FRIDAY WITH THE HEAVIEST PRECIPITATION ALONG
THE OHIO RIVER. MEANWHILE...THE EURO WAS HOLDING MORE QPF AROUND ON
SUNDAY THAN THE GFS. SO...STILL EXPECT THE PRECIPITATION TO SPREAD
NORTHEAST ACROSS THE AREA ON FRIDAY. WITH CONFIDENCE IN TIMING
LOW...WILL ACCEPT THE REGIONAL BLEND THAT KEEPS DECENT POPS AROUND
NEXT SATURDAY AS HINTED AT BY THE EURO.
REGARDING PRECIPITATION TYPE...WILL NOT MAKE MANY CHANGES WITH THE
MODEL DIFFERENCES. CONFIDENCE NOT GOOD AS TO WHERE THE RAIN/SNOW
LINE WILL BE IN SPACE AND TIME. HOWEVER...NORTHEASTERN PARTS OF THE
FORECAST AREA WILL BE MORE LIKELY TO SEE FROZEN OR MIXED
PRECIPITATION THEN THE SOUTHWESTERN ONES ON FRIDAY BASED ON
THERMAL PROFILES FROM BUFKIT SOUNDINGS AS WELL AS PARTIAL
THICKNESSES. FRIDAY NIGHT AND SATURDAY...THE NORTHWESTERN COUNTIES
WOULD HAVE A HIGHER CHANCE OF MIXED OR FROZEN PRECIPITATION THAN THE
SOUTHEAST AS COLDER AIR MOVES IN FROM THE NORTHWEST IN THE WAKE OF
THE SURFACE SYSTEM. BUFKIT SOUNDINGS EVEN SUGGEST FREEZING RAIN OR
SLEET COULD POSSIBLY MIX IN AT TIMES FRIDAY NIGHT.
GENERALLY ACCEPTED THE REGIONAL BLEND TEMPERATURES. DO NOT FEEL
CONFIDENT ENOUGH TO MAKE CHANGES UNTIL THE MODELS HOPEFULLY COME
CLOSER TOGETHER IN SUBSEQUENT RUNS. AFTERNOON HIGHS IN THE 20S LOOK
GOOD ON NEW YEAR`S DAY WITH HIGHS MOSTLY IN THE 30S THEREAFTER.
MEANWHILE...NEW YEARS EVE NIGHT SHOULD BE THE COLDEST WITH OVERNIGHT
LOWS IN THE TEENS FOR THE FIRST SUNRISE OF THE YEAR. OVERNIGHT LOWS
WILL MOSTLY BE IN THE 20S AND 30S BY LATE WEEK.
&&
.AVIATION /DISCUSSION FOR THE 28/0600Z TAF ISSUANCE/...
ISSUED AT 1211 AM EST SUN DEC 28 2014
WINDS TO REMAIN BELOW 10 KNOTS THROUGH THE FORECAST.
RAIN HAS ENDED AT ALL TAF SITES EXCEPT KBMG BUT SHOULD ALSO END THERE
WITHIN THE HOUR OR AROUND 280700Z.
WITHIN COLD AND DRY AIR ADVECTING IN...VISIBILITY HAS IMPROVED TO 6+
MILES AND WILL REMAIN THAT WAY THROUGH THE FORECAST.
MULTIPLE CLOUD LAYERS HAVE BEEN OBSERVED ACROSS ILLINOIS BUT SEEM TO
BE SETTLING TOWARDS DECKS OF 1800-2200 FEET AND THESE SHOULD PREVAIL
THROUGH THE MORNING. AS HIGH PRESSURE CONTINUES BUILDING IN AND
SUBSIDENCE BEGINS TO DRY THIS LOWER LAYER EXPECT BREAKS IN THE 2000
FOOT DECK AROUND 281800Z AND EVENTUAL CLEARING OF ALL CLOUDS BY
290000Z.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...SMF
NEAR TERM...SMF/NIELD
SHORT TERM...SMF
LONG TERM...MK
AVIATION...DT
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WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS JACKSON KY
157 PM EST SUN DEC 28 2014
.UPDATE...
ISSUED AT 157 PM EST SUN DEC 28 2014
THE CONTINUOUS RAINFALL CONTINUES TO STREAM NORTHEAST FROM THE SOUTH.
THE COLD FRONT THAT HAS PASSED THROUGH MUCH OF EASTERN KENTUCKY HAS
NEARLY STALLED OVER THE FAR EASTERN COUNTIES OF EAST KENTUCKY.
CURRENT TRENDS IN RADAR MOSAIC AND OBSERVATIONS ARE BEGINNING TO SHOW
A GRADUAL EASTWARD TREND NOW AND MUCH OF THE BLUEGRASS AREA WILL SEE
RAIN TAPERING OFF A BIT. HAVE ADJUSTED THE FORECAST FOR THIS AND THE
GRADUAL EAST TO SOUTHEAST MOVEMENT OF THE RAINFALL. THE GENERAL
CONCERN RIGHT NOW IS THE EVER SO SLOWLY DROPPING TEMPERATURES FROM
THE NORTHWEST TO SOUTHEAST. AT THIS POINT...THIS IS NOT EXPECTED TO
RESULT IN FROZEN PRECIP ACROSS THE BLUEGRASS BUT MAY RESULT IN A
CHANGE OVER IN THE HIGHER ELEVATIONS TO THE EAST TOMORROW NIGHT. A
NEW ZFP HAS BEEN ISSUED FOR THIS UPDATE.
UPDATE ISSUED AT 1042 AM EST SUN DEC 28 2014
CONDITIONS ACROSS THE AREA THIS MORNING FEATURE THE LARGE AREA OF
RAIN MOVING THROUGH EASTERN KENTUCKY. THE COLD FRONT NOW POSITIONED
IN FAR EASTERN KENTUCKY HAS SLOWED WITH A LARGE INFLUX OF MOISTURE
AHEAD AND BEHIND OF THIS FRONT IN THE FORM OF LIGHT TO MODERATE
RAINFALL. UPSTREAM...SOUTH INTO THE TN VALLEY AND SOUTHWEST INTO THE
MS VALLEY...MOISTURE CONTINUES TO STREAM NORTHWARD INTO THE AREA.
WILL EXPECT THE CHANCE OF RAIN TO CONTINUE THROUGH THE REST OF THE
DAY...SOME MODERATE TO HEAVY RAINFALL IS ALSO POSSIBLE. THIS CURRENT
TREND OF THINKING IS ALONG WITH THE CURRENT FORECAST AND WILL ALLOW
THE CURRENT ZFP TO RIDE THROUGH THE MORNING. TEMPERATURES WILL REMAIN
MAINLY STEADY SO HAVE UPDATED THE GRIDS WITH THE CURRENT OBS AND SENT
THE GRIDS TOT HE NDFD SERVERS.
UPDATE ISSUED AT 720 AM EST SUN DEC 28 2014
SLOW MOVING COLD FRONT CONTINUES TO PUSH INTO THE AREA WITH RAIN AND
DRIZZLE ALONG AND AHEAD OF THE BOUNDARY. THE MAIN BAND OF RAIN AND
DRIZZLE ASSOCIATED WITH THE FRONT CONTINUES TO DRIFT SOUTHEASTWARD
AS WELL. UPDATE CHALLENGE CENTERS AROUND THE POTENTIAL FOR A SECOND
ROUND OF RAIN A BIT LATER TODAY. NAM IS MORE PROGRESSIVE IN TAKING
ALL THIS ACTIVITY TO OUR EAST THAN THE GFS AND ECMWF...WHICH SEEM TO
HANG ON TO THE IDEA OF A SECOND WAVE TRACKING TO OUR SOUTHEAST WITH
RAIN LINGERING ACROSS A GOOD PORTION OF THE AREA...MAINLY OUR
SOUTHEAST. THE HRRR SEEMS TO HAVE THE BEST HANDLE ON THE CURRENT
SITUATION AND BRINGS ANOTHER ROUND OF PRECIPITATION OVER MOST IF NOT
ALL OF OUR FORECAST AREA BY MID MORNING. REGIONAL COMPOSITE RADAR
TENDS TO SUPPORT THE HRRR AS ECHOS ARE FILLING IN AND INTENSIFYING
ACROSS WESTERN TENNESSEE AND MOVING QUICKLY TO THE NORTHEAST. UPDATE
WILL ENTAIL ONLY MINOR TWEAKS TO THE POP GRIDS FOR RECENT RADAR
TRENDS AND AN UPDATE TO THE GRIDS FOR LATEST HOURLY OBSERVATIONS.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 425 AM EST SUN DEC 28 2014
MODELS ARE IN FAIRLY GOOD AGREEMENT FOR THE SHORT TERM. ENERGY FROM
PLAINS MID/UPPER LEVEL TROUGH WILL PASS WEST TO EAST ACROSS THE OHIO
VALLEY...WITH CORRESPONDING SFC LOW OVER NEW ENGLAND DRAGGING A SFC
COLD FRONT THROUGH THE REGION. THIS COLD FRONT IS MOVING THROUGH THE
OHIO VALLEY THIS MORNING...ROUGHLY STRETCHING FROM EAST CENTRAL OHIO
SOUTHWEST TO WESTERN TN...HAVING PASSED THOUGH CVG AND BWG. THE FRONT
WILL BE MOVING THROUGH EASTERN KENTUCKY OVER THE NEXT SEVERAL HOURS
WITH DRIZZLE AND LIGHT RAIN BEING PRODUCED ALONG AND AHEAD OF THE
BOUNDARY. THIS FEATURE WILL CARRY PRECIP EASTWARD WITH IT THROUGH THE
MORNING...RESULTING IN A POSSIBLE LULL IN RAIN FOR A PERIOD OF TIME.
BUT LOW PRESSURE CURRENTLY DEVELOPING OVER SOUTH CENTRAL MISSISSIPPI
WILL MOVE NORTHEAST INTO THE SOUTHERN APPALACHIANS THROUGH THE
DAY...RESULTING IN ANOTHER ROUND OF RAINFALL...PARTICULARLY FOR THE
SOUTHEASTERN HALF OF OUR FORECAST AREA. RAIN SHOWERS WILL LINGER
ACROSS PORTIONS OF THE AREA TONIGHT BEFORE TAPERING OFF THROUGH THE
DAY MONDAY. COOLER AIR BEHIND THE FRONT WILL BRING OUR TEMPERATURES
BACK DOWN TO NORMAL LEVELS THROUGH THE PERIOD. RAINFALL AMOUNTS HAVE
BEEN RATHER LIGHT OVERALL...AROUND A THIRD OF AN INCH IN OUR SOUTHERN
MOST COUNTIES THUS FAR AND MUCH SMALLER AMOUNTS ELSEWHERE. EXPECT TO
SEE ABOUT THE SAME AMOUNT OR LESS ACROSS THE AREA TODAY AND TONIGHT.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 425 AM EST SUN DEC 28 2014
PERIOD WILL BEGIN WITH SLIGHT CHANCE OF PRECIP LINGERING ACROSS THE
SE PORTIONS OF THE CWA...HOWEVER THESE CHANCES WILL DROP AS WE MOVE
INTO TUESDAY AS HIGH PRESSURE BUILDS EAST. THE PREVIOUS NAM DID TRY
TO BRING MORE PRECIP ACROSS THE REGION BUT THE 06Z RUN BACKED OFF ON
THIS ONCE AGAIN. THIS HIGH PRESSURE WILL CONTINUE TO USHER IN A COLDER
AIR MASS AND WILL KEEP WEATHER QUIET THROUGH WEDNESDAY NIGHT. THIS
COLDER AIR MASS WILL LEAD TO HIGHS IN THE LOW TO MID 30S FOR WEDNESDAY
AND LOWS WEDNESDAY NIGHT IN THE UPPER TEENS TO LOWER 20S. THIS
SURFACE HIGH WILL BEGIN SHIFTING TO THE EAST AND WE WILL BEGIN TO SEE
SOME RETURN FLOW AS WE MOVE INTO THURSDAY. THIS WILL ALLOW HIGHS TO
RETURN TO THE UPPER 30S AND LOWER 40S. THEN WE START TO FOCUS ON
ANOTHER SYSTEM DEVELOPING ACROSS THE SOUTHERN PLAINS. THURSDAY NIGHT A
CLOSED LOW WILL BE CENTERED ACROSS THE FOUR CORNER REGION. THIS UPPER
LEVEL LOW WILL BEGIN EJECTING EAST AND WILL AID IN DEVELOPING A LOW
PRESSURE SYSTEM ACROSS THE SOUTHERN PLAINS. CLOUDS WILL CONTINUE TO
INCREASE ACROSS THE REGION THURSDAY NIGHT AHEAD OF THIS SYSTEM. THIS
SURFACE LOW IS EXPECTED TO MOVE NORTHEAST OUT OF THE ARKLATEX AND
INTO THE GREAT LAKES REGION BY SATURDAY. INITIAL ONSET OF PRECIP
MAINLY THURSDAY NIGHT COULD BRING SNOW TO RAIN/SNOW MIX...HOWEVER AS
WARM FRONT MOVES NORTH AND EASTERN KY GETS IN THE WARM SECTOR WE WILL
SEE A CHANGE TO ALL RAIN FRIDAY. TRAILING COLD FRONT WILL MOVE ACROSS
THE REGION GOING INTO SATURDAY. MODELS ALSO INDICATE THIS SYSTEM WILL
LEAD TO A SUBSTANTIAL LOW LEVEL JET ACROSS THE REGION MAKING FOR A
WINDY DAY ACROSS EASTERN KY. THESE WINDS WILL LIKELY GUST HIGHEST
WITH SHOWER ACTIVITY ALONG AND NEAR THE COLD FRONT ALLOWING FOR
MAXIMUM MIXING.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1227 PM EST SUN DEC 28 2014
A COLD FRONT MOVING THROUGH THE AREA AND CONTINUOUS STREAMING
MOISTURE UP FROM THE SOUTHWEST THROUGH THIS EVENING AND TONIGHT WILL
RESULT IN AN EXTENDED PERIOD OF RAINFALL. THIS WILL CONTINUE TO
PRODUCE IFR CEILINGS AND MANY LOCATIONS BELOW FIELD MINS AT MANY OF
THE TAF SITES. THIS IS EXPECTED TO CONTINUE THROUGH MUCH OF THE TAF
PERIOD. RAIN AND FOG WILL HINDER VISIBILITY AS WELL WITH TAF SITES
HAVING VARYING VALUES THROUGH THE NIGHT. WINDS WILL BE LIGHT THROUGH
THE PERIOD WITH CONDITIONS IMPROVING SLIGHTLY BY THE END OF THE TAF
PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SHALLENBERGER
SHORT TERM...RAY
LONG TERM...DJ
AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS JACKSON KY
1227 PM EST SUN DEC 28 2014
.UPDATE...
ISSUED AT 1042 AM EST SUN DEC 28 2014
CONDITIONS ACROSS THE AREA THIS MORNING FEATURE THE LARGE AREA OF
RAIN MOVING THROUGH EASTERN KENTUCKY. THE COLD FRONT NOW POSITIONED
IN FAR EASTERN KENTUCKY HAS SLOWED WITH A LARGE INFLUX OF MOISTURE
AHEAD AND BEHIND OF THIS FRONT IN THE FORM OF LIGHT TO MODERATE
RAINFALL. UPSTREAM...SOUTH INTO THE TN VALLEY AND SOUTHWEST INTO THE
MS VALLEY...MOISTURE CONTINUES TO STREAM NORTHWARD INTO THE AREA.
WILL EXPECT THE CHANCE OF RAIN TO CONTINUE THROUGH THE REST OF THE
DAY...SOME MODERATE TO HEAVY RAINFALL IS ALSO POSSIBLE. THIS CURRENT
TREND OF THINKING IS ALONG WITH THE CURRENT FORECAST AND WILL ALLOW
THE CURRENT ZFP TO RIDE THROUGH THE MORNING. TEMPERATURES WILL REMAIN
MAINLY STEADY SO HAVE UPDATED THE GRIDS WITH THE CURRENT OBS AND SENT
THE GRIDS TOT HE NDFD SERVERS.
UPDATE ISSUED AT 720 AM EST SUN DEC 28 2014
SLOW MOVING COLD FRONT CONTINUES TO PUSH INTO THE AREA WITH RAIN AND
DRIZZLE ALONG AND AHEAD OF THE BOUNDARY. THE MAIN BAND OF RAIN AND
DRIZZLE ASSOCIATED WITH THE FRONT CONTINUES TO DRIFT SOUTHEASTWARD
AS WELL. UPDATE CHALLENGE CENTERS AROUND THE POTENTIAL FOR A SECOND
ROUND OF RAIN A BIT LATER TODAY. NAM IS MORE PROGRESSIVE IN TAKING
ALL THIS ACTIVITY TO OUR EAST THAN THE GFS AND ECMWF...WHICH SEEM TO
HANG ON TO THE IDEA OF A SECOND WAVE TRACKING TO OUR SOUTHEAST WITH
RAIN LINGERING ACROSS A GOOD PORTION OF THE AREA...MAINLY OUR
SOUTHEAST. THE HRRR SEEMS TO HAVE THE BEST HANDLE ON THE CURRENT
SITUATION AND BRINGS ANOTHER ROUND OF PRECIPITATION OVER MOST IF NOT
ALL OF OUR FORECAST AREA BY MID MORNING. REGIONAL COMPOSITE RADAR
TENDS TO SUPPORT THE HRRR AS ECHOS ARE FILLING IN AND INTENSIFYING
ACROSS WESTERN TENNESSEE AND MOVING QUICKLY TO THE NORTHEAST. UPDATE
WILL ENTAIL ONLY MINOR TWEAKS TO THE POP GRIDS FOR RECENT RADAR
TRENDS AND AN UPDATE TO THE GRIDS FOR LATEST HOURLY OBSERVATIONS.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 425 AM EST SUN DEC 28 2014
MODELS ARE IN FAIRLY GOOD AGREEMENT FOR THE SHORT TERM. ENERGY FROM
PLAINS MID/UPPER LEVEL TROUGH WILL PASS WEST TO EAST ACROSS THE OHIO
VALLEY...WITH CORRESPONDING SFC LOW OVER NEW ENGLAND DRAGGING A SFC
COLD FRONT THROUGH THE REGION. THIS COLD FRONT IS MOVING THROUGH THE
OHIO VALLEY THIS MORNING...ROUGHLY STRETCHING FROM EAST CENTRAL OHIO
SOUTHWEST TO WESTERN TN...HAVING PASSED THOUGH CVG AND BWG. THE FRONT
WILL BE MOVING THROUGH EASTERN KENTUCKY OVER THE NEXT SEVERAL HOURS
WITH DRIZZLE AND LIGHT RAIN BEING PRODUCED ALONG AND AHEAD OF THE
BOUNDARY. THIS FEATURE WILL CARRY PRECIP EASTWARD WITH IT THROUGH THE
MORNING...RESULTING IN A POSSIBLE LULL IN RAIN FOR A PERIOD OF TIME.
BUT LOW PRESSURE CURRENTLY DEVELOPING OVER SOUTH CENTRAL MISSISSIPPI
WILL MOVE NORTHEAST INTO THE SOUTHERN APPALACHIANS THROUGH THE
DAY...RESULTING IN ANOTHER ROUND OF RAINFALL...PARTICULARLY FOR THE
SOUTHEASTERN HALF OF OUR FORECAST AREA. RAIN SHOWERS WILL LINGER
ACROSS PORTIONS OF THE AREA TONIGHT BEFORE TAPERING OFF THROUGH THE
DAY MONDAY. COOLER AIR BEHIND THE FRONT WILL BRING OUR TEMPERATURES
BACK DOWN TO NORMAL LEVELS THROUGH THE PERIOD. RAINFALL AMOUNTS HAVE
BEEN RATHER LIGHT OVERALL...AROUND A THIRD OF AN INCH IN OUR SOUTHERN
MOST COUNTIES THUS FAR AND MUCH SMALLER AMOUNTS ELSEWHERE. EXPECT TO
SEE ABOUT THE SAME AMOUNT OR LESS ACROSS THE AREA TODAY AND TONIGHT.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 425 AM EST SUN DEC 28 2014
PERIOD WILL BEGIN WITH SLIGHT CHANCE OF PRECIP LINGERING ACROSS THE
SE PORTIONS OF THE CWA...HOWEVER THESE CHANCES WILL DROP AS WE MOVE
INTO TUESDAY AS HIGH PRESSURE BUILDS EAST. THE PREVIOUS NAM DID TRY
TO BRING MORE PRECIP ACROSS THE REGION BUT THE 06Z RUN BACKED OFF ON
THIS ONCE AGAIN. THIS HIGH PRESSURE WILL CONTINUE TO USHER IN A COLDER
AIR MASS AND WILL KEEP WEATHER QUIET THROUGH WEDNESDAY NIGHT. THIS
COLDER AIR MASS WILL LEAD TO HIGHS IN THE LOW TO MID 30S FOR WEDNESDAY
AND LOWS WEDNESDAY NIGHT IN THE UPPER TEENS TO LOWER 20S. THIS
SURFACE HIGH WILL BEGIN SHIFTING TO THE EAST AND WE WILL BEGIN TO SEE
SOME RETURN FLOW AS WE MOVE INTO THURSDAY. THIS WILL ALLOW HIGHS TO
RETURN TO THE UPPER 30S AND LOWER 40S. THEN WE START TO FOCUS ON
ANOTHER SYSTEM DEVELOPING ACROSS THE SOUTHERN PLAINS. THURSDAY NIGHT A
CLOSED LOW WILL BE CENTERED ACROSS THE FOUR CORNER REGION. THIS UPPER
LEVEL LOW WILL BEGIN EJECTING EAST AND WILL AID IN DEVELOPING A LOW
PRESSURE SYSTEM ACROSS THE SOUTHERN PLAINS. CLOUDS WILL CONTINUE TO
INCREASE ACROSS THE REGION THURSDAY NIGHT AHEAD OF THIS SYSTEM. THIS
SURFACE LOW IS EXPECTED TO MOVE NORTHEAST OUT OF THE ARKLATEX AND
INTO THE GREAT LAKES REGION BY SATURDAY. INITIAL ONSET OF PRECIP
MAINLY THURSDAY NIGHT COULD BRING SNOW TO RAIN/SNOW MIX...HOWEVER AS
WARM FRONT MOVES NORTH AND EASTERN KY GETS IN THE WARM SECTOR WE WILL
SEE A CHANGE TO ALL RAIN FRIDAY. TRAILING COLD FRONT WILL MOVE ACROSS
THE REGION GOING INTO SATURDAY. MODELS ALSO INDICATE THIS SYSTEM WILL
LEAD TO A SUBSTANTIAL LOW LEVEL JET ACROSS THE REGION MAKING FOR A
WINDY DAY ACROSS EASTERN KY. THESE WINDS WILL LIKELY GUST HIGHEST
WITH SHOWER ACTIVITY ALONG AND NEAR THE COLD FRONT ALLOWING FOR
MAXIMUM MIXING.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1227 PM EST SUN DEC 28 2014
A COLD FRONT MOVING THROUGH THE AREA AND CONTINUOUS STREAMING
MOISTURE UP FROM THE SOUTHWEST THROUGH THIS EVENING AND TONIGHT WILL
RESULT IN AN EXTENDED PERIOD OF RAINFALL. THIS WILL CONTINUE TO
PRODUCE IFR CEILINGS AND MANY LOCATIONS BELOW FIELD MINS AT MANY OF
THE TAF SITES. THIS IS EXPECTED TO CONTINUE THROUGH MUCH OF THE TAF
PERIOD. RAIN AND FOG WILL HINDER VISIBILITY AS WELL WITH TAF SITES
HAVING VARYING VALUES THROUGH THE NIGHT. WINDS WILL BE LIGHT THROUGH
THE PERIOD WITH CONDITIONS IMPROVING SLIGHTLY BY THE END OF THE TAF
PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SHALLENBERGER
SHORT TERM...RAY
LONG TERM...DJ
AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS JACKSON KY
1042 AM EST SUN DEC 28 2014
.UPDATE...
ISSUED AT 1042 AM EST SUN DEC 28 2014
CONDITIONS ACROSS THE AREA THIS MORNING FEATURE THE LARGE AREA OF
RAIN MOVING THROUGH EASTERN KENTUCKY. THE COLD FRONT NOW POSITIONED
IN FAR EASTERN KENTUCKY HAS SLOWED WITH A LARGE INFLUX OF MOISTURE
AHEAD AND BEHIND OF THIS FRONT IN THE FORM OF LIGHT TO MODERATE
RAINFALL. UPSTREAM...SOUTH INTO THE TN VALLEY AND SOUTHWEST INTO THE
MS VALLEY...MOISTURE CONTINUES TO STREAM NORTHWARD INTO THE AREA.
WILL EXPECT THE CHANCE OF RAIN TO CONTINUE THROUGH THE REST OF THE
DAY...SOME MODERATE TO HEAVY RAINFALL IS ALSO POSSIBLE. THIS CURRENT
TREND OF THINKING IS ALONG WITH THE CURRENT FORECAST AND WILL ALLOW
THE CURRENT ZFP TO RIDE THROUGH THE MORNING. TEMPERATURES WILL REMAIN
MAINLY STEADY SO HAVE UPDATED THE GRIDS WITH THE CURRENT OBS AND SENT
THE GRIDS TOT HE NDFD SERVERS.
UPDATE ISSUED AT 720 AM EST SUN DEC 28 2014
SLOW MOVING COLD FRONT CONTINUES TO PUSH INTO THE AREA WITH RAIN AND
DRIZZLE ALONG AND AHEAD OF THE BOUNDARY. THE MAIN BAND OF RAIN AND
DRIZZLE ASSOCIATED WITH THE FRONT CONTINUES TO DRIFT SOUTHEASTWARD
AS WELL. UPDATE CHALLENGE CENTERS AROUND THE POTENTIAL FOR A SECOND
ROUND OF RAIN A BIT LATER TODAY. NAM IS MORE PROGRESSIVE IN TAKING
ALL THIS ACTIVITY TO OUR EAST THAN THE GFS AND ECMWF...WHICH SEEM TO
HANG ON TO THE IDEA OF A SECOND WAVE TRACKING TO OUR SOUTHEAST WITH
RAIN LINGERING ACROSS A GOOD PORTION OF THE AREA...MAINLY OUR
SOUTHEAST. THE HRRR SEEMS TO HAVE THE BEST HANDLE ON THE CURRENT
SITUATION AND BRINGS ANOTHER ROUND OF PRECIPITATION OVER MOST IF NOT
ALL OF OUR FORECAST AREA BY MID MORNING. REGIONAL COMPOSITE RADAR
TENDS TO SUPPORT THE HRRR AS ECHOS ARE FILLING IN AND INTENSIFYING
ACROSS WESTERN TENNESSEE AND MOVING QUICKLY TO THE NORTHEAST. UPDATE
WILL ENTAIL ONLY MINOR TWEAKS TO THE POP GRIDS FOR RECENT RADAR
TRENDS AND AN UPDATE TO THE GRIDS FOR LATEST HOURLY OBSERVATIONS.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 425 AM EST SUN DEC 28 2014
MODELS ARE IN FAIRLY GOOD AGREEMENT FOR THE SHORT TERM. ENERGY FROM
PLAINS MID/UPPER LEVEL TROUGH WILL PASS WEST TO EAST ACROSS THE OHIO
VALLEY...WITH CORRESPONDING SFC LOW OVER NEW ENGLAND DRAGGING A SFC
COLD FRONT THROUGH THE REGION. THIS COLD FRONT IS MOVING THROUGH THE
OHIO VALLEY THIS MORNING...ROUGHLY STRETCHING FROM EAST CENTRAL OHIO
SOUTHWEST TO WESTERN TN...HAVING PASSED THOUGH CVG AND BWG. THE FRONT
WILL BE MOVING THROUGH EASTERN KENTUCKY OVER THE NEXT SEVERAL HOURS
WITH DRIZZLE AND LIGHT RAIN BEING PRODUCED ALONG AND AHEAD OF THE
BOUNDARY. THIS FEATURE WILL CARRY PRECIP EASTWARD WITH IT THROUGH THE
MORNING...RESULTING IN A POSSIBLE LULL IN RAIN FOR A PERIOD OF TIME.
BUT LOW PRESSURE CURRENTLY DEVELOPING OVER SOUTH CENTRAL MISSISSIPPI
WILL MOVE NORTHEAST INTO THE SOUTHERN APPALACHIANS THROUGH THE
DAY...RESULTING IN ANOTHER ROUND OF RAINFALL...PARTICULARLY FOR THE
SOUTHEASTERN HALF OF OUR FORECAST AREA. RAIN SHOWERS WILL LINGER
ACROSS PORTIONS OF THE AREA TONIGHT BEFORE TAPERING OFF THROUGH THE
DAY MONDAY. COOLER AIR BEHIND THE FRONT WILL BRING OUR TEMPERATURES
BACK DOWN TO NORMAL LEVELS THROUGH THE PERIOD. RAINFALL AMOUNTS HAVE
BEEN RATHER LIGHT OVERALL...AROUND A THIRD OF AN INCH IN OUR SOUTHERN
MOST COUNTIES THUS FAR AND MUCH SMALLER AMOUNTS ELSEWHERE. EXPECT TO
SEE ABOUT THE SAME AMOUNT OR LESS ACROSS THE AREA TODAY AND TONIGHT.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 425 AM EST SUN DEC 28 2014
PERIOD WILL BEGIN WITH SLIGHT CHANCE OF PRECIP LINGERING ACROSS THE
SE PORTIONS OF THE CWA...HOWEVER THESE CHANCES WILL DROP AS WE MOVE
INTO TUESDAY AS HIGH PRESSURE BUILDS EAST. THE PREVIOUS NAM DID TRY
TO BRING MORE PRECIP ACROSS THE REGION BUT THE 06Z RUN BACKED OFF ON
THIS ONCE AGAIN. THIS HIGH PRESSURE WILL CONTINUE TO USHER IN A COLDER
AIR MASS AND WILL KEEP WEATHER QUIET THROUGH WEDNESDAY NIGHT. THIS
COLDER AIR MASS WILL LEAD TO HIGHS IN THE LOW TO MID 30S FOR WEDNESDAY
AND LOWS WEDNESDAY NIGHT IN THE UPPER TEENS TO LOWER 20S. THIS
SURFACE HIGH WILL BEGIN SHIFTING TO THE EAST AND WE WILL BEGIN TO SEE
SOME RETURN FLOW AS WE MOVE INTO THURSDAY. THIS WILL ALLOW HIGHS TO
RETURN TO THE UPPER 30S AND LOWER 40S. THEN WE START TO FOCUS ON
ANOTHER SYSTEM DEVELOPING ACROSS THE SOUTHERN PLAINS. THURSDAY NIGHT A
CLOSED LOW WILL BE CENTERED ACROSS THE FOUR CORNER REGION. THIS UPPER
LEVEL LOW WILL BEGIN EJECTING EAST AND WILL AID IN DEVELOPING A LOW
PRESSURE SYSTEM ACROSS THE SOUTHERN PLAINS. CLOUDS WILL CONTINUE TO
INCREASE ACROSS THE REGION THURSDAY NIGHT AHEAD OF THIS SYSTEM. THIS
SURFACE LOW IS EXPECTED TO MOVE NORTHEAST OUT OF THE ARKLATEX AND
INTO THE GREAT LAKES REGION BY SATURDAY. INITIAL ONSET OF PRECIP
MAINLY THURSDAY NIGHT COULD BRING SNOW TO RAIN/SNOW MIX...HOWEVER AS
WARM FRONT MOVES NORTH AND EASTERN KY GETS IN THE WARM SECTOR WE WILL
SEE A CHANGE TO ALL RAIN FRIDAY. TRAILING COLD FRONT WILL MOVE ACROSS
THE REGION GOING INTO SATURDAY. MODELS ALSO INDICATE THIS SYSTEM WILL
LEAD TO A SUBSTANTIAL LOW LEVEL JET ACROSS THE REGION MAKING FOR A
WINDY DAY ACROSS EASTERN KY. THESE WINDS WILL LIKELY GUST HIGHEST
WITH SHOWER ACTIVITY ALONG AND NEAR THE COLD FRONT ALLOWING FOR
MAXIMUM MIXING.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 720 AM EST SUN DEC 28 2014
COLD FRONT MOVING THROUGH THE AREA THIS MORNING WILL KEEP FLIGHT
CONDITIONS QUITE LOW. MODEL GUIDANCE...INITIALLY VERY SLOW TO PICK
UP ON THE WORSENING WEATHER HAS FINALLY COME IN LINE WITH ACTUAL
CONDITIONS THIS MORNING. AND FROM ALL APPEARANCES WE WILL SEE RAIN
LINGER ACROSS MOST IF NOT ALL OF OUR AREA THROUGH THE DAY.
CONSEQUENTLY FOLLOWED GUIDANCE CLOSELY WHICH WAS VERY PESSIMISTIC...
WITH IFR/LIFR CONDITIONS EXPECTED FOR MOST OF THE FORECAST WINDOW.
WINDS ARE...AND WILL CONTINUE TO VEER MORE NORTHERLY WITH TIME AT
AROUND 5 KTS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SHALLENBERGER
SHORT TERM...RAY
LONG TERM...DJ
AVIATION...RAY
AREA FORECAST DISCUSSION
NWS JACKSON KY
720 AM EST SUN DEC 28 2014
.UPDATE...
ISSUED AT 720 AM EST SUN DEC 28 2014
SLOW MOVING COLD FRONT CONTINUES TO PUSH INTO THE AREA WITH RAIN AND
DRIZZLE ALONG AND AHEAD OF THE BOUNDARY. THE MAIN BAND OF RAIN AND
DRIZZLE ASSOCIATED WITH THE FRONT CONTINUES TO DRIFT SOUTHEASTWARD
AS WELL. UPDATE CHALLENGE CENTERS AROUND THE POTENTIAL FOR A SECOND
ROUND OF RAIN A BIT LATER TODAY. NAM IS MORE PROGRESSIVE IN TAKING
ALL THIS ACTIVITY TO OUR EAST THAN THE GFS AND ECMWF...WHICH SEEM TO
HANG ON TO THE IDEA OF A SECOND WAVE TRACKING TO OUR SOUTHEAST WITH
RAIN LINGERING ACROSS A GOOD PORTION OF THE AREA...MAINLY OUR
SOUTHEAST. THE HRRR SEEMS TO HAVE THE BEST HANDLE ON THE CURRENT
SITUATION AND BRINGS ANOTHER ROUND OF PRECIPITATION OVER MOST IF NOT
ALL OF OUR FORECAST AREA BY MID MORNING. REGIONAL COMPOSITE RADAR
TENDS TO SUPPORT THE HRRR AS ECHOS ARE FILLING IN AND INTENSIFYING
ACROSS WESTERN TENNESSEE AND MOVING QUICKLY TO THE NORTHEAST. UPDATE
WILL ENTAIL ONLY MINOR TWEAKS TO THE POP GRIDS FOR RECENT RADAR
TRENDS AND AN UPDATE TO THE GRIDS FOR LATEST HOURLY OBSERVATIONS.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 425 AM EST SUN DEC 28 2014
MODELS ARE IN FAIRLY GOOD AGREEMENT FOR THE SHORT TERM. ENERGY FROM
PLAINS MID/UPPER LEVEL TROUGH WILL PASS WEST TO EAST ACROSS THE OHIO
VALLEY...WITH CORRESPONDING SFC LOW OVER NEW ENGLAND DRAGGING A SFC
COLD FRONT THROUGH THE REGION. THIS COLD FRONT IS MOVING THROUGH THE
OHIO VALLEY THIS MORNING...ROUGHLY STRETCHING FROM EAST CENTRAL OHIO
SOUTHWEST TO WESTERN TN...HAVING PASSED THOUGH CVG AND BWG. THE FRONT
WILL BE MOVING THROUGH EASTERN KENTUCKY OVER THE NEXT SEVERAL HOURS
WITH DRIZZLE AND LIGHT RAIN BEING PRODUCED ALONG AND AHEAD OF THE
BOUNDARY. THIS FEATURE WILL CARRY PRECIP EASTWARD WITH IT THROUGH THE
MORNING...RESULTING IN A POSSIBLE LULL IN RAIN FOR A PERIOD OF TIME.
BUT LOW PRESSURE CURRENTLY DEVELOPING OVER SOUTH CENTRAL MISSISSIPPI
WILL MOVE NORTHEAST INTO THE SOUTHERN APPALACHIANS THROUGH THE
DAY...RESULTING IN ANOTHER ROUND OF RAINFALL...PARTICULARLY FOR THE
SOUTHEASTERN HALF OF OUR FORECAST AREA. RAIN SHOWERS WILL LINGER
ACROSS PORTIONS OF THE AREA TONIGHT BEFORE TAPERING OFF THROUGH THE
DAY MONDAY. COOLER AIR BEHIND THE FRONT WILL BRING OUR TEMPERATURES
BACK DOWN TO NORMAL LEVELS THROUGH THE PERIOD. RAINFALL AMOUNTS HAVE
BEEN RATHER LIGHT OVERALL...AROUND A THIRD OF AN INCH IN OUR SOUTHERN
MOST COUNTIES THUS FAR AND MUCH SMALLER AMOUNTS ELSEWHERE. EXPECT TO
SEE ABOUT THE SAME AMOUNT OR LESS ACROSS THE AREA TODAY AND TONIGHT.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 425 AM EST SUN DEC 28 2014
PERIOD WILL BEGIN WITH SLIGHT CHANCE OF PRECIP LINGERING ACROSS THE
SE PORTIONS OF THE CWA...HOWEVER THESE CHANCES WILL DROP AS WE MOVE
INTO TUESDAY AS HIGH PRESSURE BUILDS EAST. THE PREVIOUS NAM DID TRY
TO BRING MORE PRECIP ACROSS THE REGION BUT THE 06Z RUN BACKED OFF ON
THIS ONCE AGAIN. THIS HIGH PRESSURE WILL CONTINUE TO USHER IN A COLDER
AIR MASS AND WILL KEEP WEATHER QUIET THROUGH WEDNESDAY NIGHT. THIS
COLDER AIR MASS WILL LEAD TO HIGHS IN THE LOW TO MID 30S FOR WEDNESDAY
AND LOWS WEDNESDAY NIGHT IN THE UPPER TEENS TO LOWER 20S. THIS
SURFACE HIGH WILL BEGIN SHIFTING TO THE EAST AND WE WILL BEGIN TO SEE
SOME RETURN FLOW AS WE MOVE INTO THURSDAY. THIS WILL ALLOW HIGHS TO
RETURN TO THE UPPER 30S AND LOWER 40S. THEN WE START TO FOCUS ON
ANOTHER SYSTEM DEVELOPING ACROSS THE SOUTHERN PLAINS. THURSDAY NIGHT A
CLOSED LOW WILL BE CENTERED ACROSS THE FOUR CORNER REGION. THIS UPPER
LEVEL LOW WILL BEGIN EJECTING EAST AND WILL AID IN DEVELOPING A LOW
PRESSURE SYSTEM ACROSS THE SOUTHERN PLAINS. CLOUDS WILL CONTINUE TO
INCREASE ACROSS THE REGION THURSDAY NIGHT AHEAD OF THIS SYSTEM. THIS
SURFACE LOW IS EXPECTED TO MOVE NORTHEAST OUT OF THE ARKLATEX AND
INTO THE GREAT LAKES REGION BY SATURDAY. INITIAL ONSET OF PRECIP
MAINLY THURSDAY NIGHT COULD BRING SNOW TO RAIN/SNOW MIX...HOWEVER AS
WARM FRONT MOVES NORTH AND EASTERN KY GETS IN THE WARM SECTOR WE WILL
SEE A CHANGE TO ALL RAIN FRIDAY. TRAILING COLD FRONT WILL MOVE ACROSS
THE REGION GOING INTO SATURDAY. MODELS ALSO INDICATE THIS SYSTEM WILL
LEAD TO A SUBSTANTIAL LOW LEVEL JET ACROSS THE REGION MAKING FOR A
WINDY DAY ACROSS EASTERN KY. THESE WINDS WILL LIKELY GUST HIGHEST
WITH SHOWER ACTIVITY ALONG AND NEAR THE COLD FRONT ALLOWING FOR
MAXIMUM MIXING.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 720 AM EST SUN DEC 28 2014
COLD FRONT MOVING THROUGH THE AREA THIS MORNING WILL KEEP FLIGHT
CONDITIONS QUITE LOW. MODEL GUIDANCE...INITIALLY VERY SLOW TO PICK
UP ON THE WORSENING WEATHER HAS FINALLY COME IN LINE WITH ACTUAL
CONDITIONS THIS MORNING. AND FROM ALL APPEARANCES WE WILL SEE RAIN
LINGER ACROSS MOST IF NOT ALL OF OUR AREA THROUGH THE DAY.
CONSEQUENTLY FOLLOWED GUIDANCE CLOSELY WHICH WAS VERY PESSIMISTIC...
WITH IFR/LIFR CONDITIONS EXPECTED FOR MOST OF THE FORECAST WINDOW.
WINDS ARE...AND WILL CONTINUE TO VEER MORE NORTHERLY WITH TIME AT
AROUND 5 KTS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE...RAY
SHORT TERM...RAY
LONG TERM...DJ
AVIATION...RAY
AREA FORECAST DISCUSSION
NWS JACKSON KY
150 AM EST SUN DEC 28 2014
.UPDATE...
ISSUED AT 150 AM EST SUN DEC 28 2014
MADE SOME MINOR TWEAKS TO THE GRIDS FOR LATEST TRENDS IN RADAR AND
OBS. OVERALL NO MAJOR CHANGES TO THE FORECAST PACKAGE. LIGHT RAIN AND
DRIZZLE WILL CONTINUE TO OVERSPREAD THE AREA AS A COLD FRONTAL
BOUNDARY DROPS DOWN INTO OUR FORECAST AREA OVER THE NEXT SEVERAL
HOURS.
UPDATE ISSUED AT 1030 PM EST SAT DEC 27 2014
DID AN UPDATE TO FINE TUNE THE POPS THROUGH THE REST OF THE
NIGHT...MORE IN LINE WITH THE LATEST HRRR GUIDANCE. THE HRRR SHOWED
THAT THE PCPN WOULD PUSH IN MOST EFFECTIVELY FROM THE NORTHWEST
DURING THE EARLY MORNING HOURS WHILE THE FAR EAST STAYS NO WORSE THAN
SCATTERED FOR MUCH OF THE NIGHT. ALSO TWEAKED THE T AND TD GRIDS PER
THE LATEST OBS AND TRENDS. THESE HAVE BEEN SENT TO THE NDFD AND WEB
SERVERS ALONG WITH A NEW SET OF ZONES.
UPDATE ISSUED AT 750 PM EST SAT DEC 27 2014
23Z SFC ANALYSIS SHOWS AN AREA OF LOW PRESSURE PUSHING INTO EASTERN
KENTUCKY FROM THE SOUTHWEST. THIS HAS BROUGHT AN EARLY ROUND OF
SHOWERS TO THE CUMBERLAND VALLEY. THESE HAVE BEEN BATTLING THE DRY
AIR IN PLACE THROUGH THE AREA...BUT HAVE BEEN ABLE TO REACH THE
GROUND WITH THE HEAVIER RETURNS. THESE SHOWERS WILL CONTINUE TO
MOISTEN UP THE LOWER ATMOSPHERE THIS EVENING WITH THE NEXT SURGE
AFTER MIDNIGHT LIKELY TO BRING WIDESPREAD RAIN TO THE ENTIRE CWA.
WITH DEW POINTS IN THE 40S...ONCE THE RAIN MOVES IN PROPERLY...LOW
TEMPERATURES WILL BE CAPPED IN THE LOW TO MIDDLE 40S. HAVE UPDATED
THE FORECAST TO FINE TUNE THE POP CHANCES AND INFUSE SOME OF THE
LATEST NEAR TERM GUIDANCE INTO THE T AND TD GRIDS. THESE UPDATES HAVE
BEEN SENT TO NDFD AND THE WEB SERVERS. A ZFP UPDATE WILL FOLLOW LATER
THIS EVENING ONCE THE WIDESPREAD RAINS ARE ON OUR DOORSTEP.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 331 PM EST SAT DEC 27 2014
CURRENT CONDITIONS ACROSS THE REGION FEATURE SURFACE LOW PRESSURE
STRENGTHENING AS IT MOVES NORTHEAST INTO THE GREAT LAKES REGION.
MEANWHILE...A SURFACE COLD FRONT ASSOCIATED WITH THIS LOW AS OF 20Z
IS PUSHING INTO WESTERN KENTUCKY WITH A SWATH OF RAIN MOVING UP FROM
THE MID MS RIVER VALLEY INTO CENTRAL KENTUCKY. WIDESPREAD CLOUD COVER
AND RAIN CONTINUES TO PUSH EAST BUT SURFACE HIGH PRESSURE CENTERED
JUST OFF THE NC COAST IS RETREATING SLIGHTLY SLOWER THAN ANTICIPATED.
HENCE SOME BREAKS IN CLOUD COVER STILL ARE PRESENT IN EASTERN
KENTUCKY. THIS WILL KEEP PRECIP OUT OF THE AREA A TAD LONGER...BUT AN
NEW DEVELOPING SURFACE LOW PRESSURE ALONG THE WESTERN GULF COAST AND
STRENGTHENING LOW LEVEL JET WILL REINFORCE THE MOISTURE SURGE
NORTHEASTWARD INTO THE TN VALLEY AND OH VALLEY BY TONIGHT AND
ESPECIALLY SUNDAY. MODELS SUPPORT THIS TREND AND AS SUCH...AM QUITE
CONFIDENT THAT MEASURABLE PRECIP WILL MATERIALIZE TONIGHT AND HAVE
GONE WITH CATEGORICAL POPS.
THE STUBBORN RIDGE OVER THE BAHAMAS REMAINS IN PLACE THROUGH THE
REST OF THE WEEKEND BEFORE WEAKENING LATE MONDAY AS THE TROUGH OVER
THE EASTERN CONUS LIFTS INTO THE NEW ENGLAND STATES. THROUGH THIS
PERIOD THOUGH...QUITE A STRONG MOIST LOW LEVEL SOUTHWEST FLOW WILL
KEEP RAIN OVER EASTERN KENTUCKY THROUGH MONDAY MORNING BEFORE ENDING
FROM NORTHWEST TO SOUTHEAST ON MONDAY NIGHT. LOW LEVEL MOISTURE MAY
BE SLOW ENOUGH TO EXIT BEHIND THE FRONT THAT COLDER AIR MOVING IN MAY
ALLOW FOR SOME BRIEF INSTANCES OF SNOW MIXING WITH THE RAIN OR
CHANGING TO ALL SNOW IN THE NORTHWEST BLUEGRASS COUNTIES AND THE
HIGHER TERRAIN IN THE COUNTIES BORDERING VIRGINIA. ANY INSTANCES THAT
DO OCCUR ARE EXPECTED TO BE BRIEF AND NO ACCUMULATION IS EXPECTED.
OVERALL...A WET AND RAINY END TO THE WEEKEND AND BEGINNING TO THE NEW
WEEK IS ON TAP.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 358 PM EST SAT DEC 27 2014
A COLD FRONT...AND WEAK WAVES OF LOW PRESSURE MOVING ALONG IT...WILL
BE EXITING THE AREA TO BEGIN THE EXTENDED PERIOD ON MONDAY. BASED ON
THE LATEST MODEL TIME HEIGHTS AND SOUNDINGS...WEAK UPSLOPE FLOW AND
RESIDUAL MOISTURE BEHIND THE DEPARTING BOUNDARY MAY ALLOW ISOLATED TO
SCATTERED RAIN AND SNOW SHOWERS TO LINGER BEHIND THE FRONT. BASED ON
MOISTURE AVAILABILITY AND THE LACK OF ICE CRYSTAL GROWTH
ALOFT...PRECIPITATION SHOULD INITIALLY BE IN THE FORM OF RAIN SHOWERS
THROUGH AROUND 12Z ON MONDAY. AFTER THAT...ENOUGH COLD AIR SHOULD
SPILL INTO THE REGION TO ALLOW SOME SNOW FLURRIES TO MIX WITH
SPRINKLES OR LIGHT RAIN SHOWERS MONDAY NIGHT THROUGH EARLY TUESDAY
MORNING. THE NAM12 SOUNDINGS SEEMED TO HAVE THE BEST HANDLE ON THE
TRANSITION BETWEEN PRECIP TYPES...SO THAT MODEL WAS USED TO CREATE
THE POPS AND PRECIP TYPES THROUGH EARLY TUESDAY MORNING. ONCE THE
PRECIP EXITS THE AREA TUESDAY MORNING...A RIDGE OF HIGH PRESSURE WILL
INFLUENCE THE REGIONS WEATHER THROUGH LATE THURSDAY MORNING. A FAIRLY
POTENT AREA OF LOW PRESSURE IS THEN FORECAST TO FORM IN THE SOUTHERN
JET STREAM OVER THE SOUTHERN ROCKY MOUNTAINS. AS THIS SYSTEM ADVANCES
EASTWARD...THE MODELS HAVE IT TAPPING INTO AMPLE GULF OF MEXICO
MOISTURE WEDNESDAY NIGHT AND THURSDAY. SHOULD THE MODELS PAN OUT...THE
FIRST PRECIP WOULD ENTER EASTERN KENTUCKY AROUND NOON ON THURSDAY AND
GRADUALLY OVERSPREAD THE AREA FROM THERE. BY 2 OR 3Z FRIDAY...THE
SYSTEM WILL TAP INTO SOME COLDER AIR...ALLOWING FOR PRECIP ALONG THE
NORTHERN FRINGE OF THE PRECIPITATION SHIELD TO MIX WITH SNOW. THE
PRECIP SHOULD TRANSITION TO ALL SNOW BY AROUND 6Z FRIDAY AS MORE COLD
AIR SPILLS IN FROM THE NORTH. WARMER AIR IS THEN FORECAST TO PROGRESS
NORTHWARD INTO THE AREA FRIDAY MORNING...ALLOWING PRECIP TO
TRANSITION BACK TO A RAIN SNOW MIX AND THEN RAIN BY EARLY FRIDAY
AFTERNOON. AT THIS TIME THERE IS TOO MUCH UNCERTAINTY AS TO THE EXACT
TRACK OF THE SOUTHERN STREAM LOW AND THE AMOUNT OF COLD AIR THAT WILL
BE AVAILABLE FOR THE TRANSITION TO SNOW. THEREFORE...HAVE ELECTED TO
GO WITH ONLY MINIMAL SNOW ACCUMULATIONS THURSDAY NIGHT INTO FRIDAY
MORNING.
TEMPERATURES THROUGHOUT THE EXTENDED PERIOD LOOK TO BE WELL BELOW
NORMAL BASED ON THE CURRENT MOS GUIDANCE. BASED ON THE LATEST MODEL
SOUNDINGS...DECIDED TO CONTINUE WITH THIS OVERALL TREND UNTIL THE
DATA SETTLES ON A SOLUTION. THE COLDEST DAYS UPCOMING LOOK TO BE
TUESDAY THROUGH THURSDAY...AS COLD AIR INVADES BEHIND THE INITIAL
FRONTAL BOUNDARY. DAYTIME HIGHS ON THOSE THREE DAYS MAY NOT RISE OUT
OF THE 30S ACROSS THE AREA. FRIDAY SHOULD BE SLIGHTLY WARMER AS WINDS
SHIFT TO THE SOUTH...WITH HIGH IN THE LOWER 40S ON TAP.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 150 AM EST SUN DEC 28 2014
FLIGHT CONDITIONS WILL DETERIORATE THROUGH THE FIRST FEW HOURS OF THE
FORECAST AS DRIZZLE AND LIGHT RAIN OVERSPREAD THE AREA FROM THE WEST.
FOLLOWED MODEL GUIDANCE...BRINGING CONDITIONS DOWN GRADUALLY. BUT
OBSERVATIONS AT LEAST INITIALLY SUGGEST A QUICKER TRANSITION. LIGHT
RAIN AND DRIZZLE WILL LINGER THROUGH THE DAY TODAY WITH SOME
IMPROVEMENT POSSIBLE AT THE END OF THE FORECAST WINDOW. WINDS WILL
GRADUALLY VEER OUT OF THE NORTHWEST AT AROUND 5 KTS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE...RAY
SHORT TERM...SHALLENBERGER
LONG TERM...AR
AVIATION...RAY
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
406 AM EST SUN DEC 28 2014
.SYNOPSIS...
A COLD FRONT OVER OHIO WILL MOVE INTO THE AREA TODAY. LOW
PRESSURE WILL MOVE ALONG THE STALLED FRONT THIS AFTERNOON AND
EVENING... PUSHING THE FRONT SOUTH OF THE AREA. ANOTHER LOW
PRESSURE SYSTEM WILL MOVE ACROSS THE CAROLINAS MONDAY AND MONDAY
NIGHT. STRONG HIGH PRESSURE WILL BUILD OVER MUCH OF THE COUNTRY BY
TUESDAY...AND GRADUALLY PUSH EASTWARD DURING THE REST OF THE WORK
WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 08Z...1025MB SFC HIGH IS APPROACHING BERMUDA WHILE 999MB SFC
LOW IN QUEBEC. THE ASSOCIATED COLD FRONT IS HALFWAY ACROSS OHIO WITH
SUBTROPICAL AIR OVER THE MID-ATLANTIC. AN UPR TROUGH AXIS IS OVER
THE SRN GREAT PLAINS. TEMPERATURES HAVE RISEN OVER THE CWA WITH AN
INCREASE IN CLOUD COVER WITH TEMPERATURES IN MIXED AREAS IN THE UPR
40S TO AROUND 50F. SOME POCKETS OF UPR 30S PERSIST IN DECOUPLED
AREAS. RAPID INCREASES INTO THE MID OR POSSIBLY UPR 50S ARE POSSIBLE
THIS MORNING WITH 14C AIR AT 925MB OVER THE AREA. HOWEVER...
THICKENING CLOUDS SHOULD GENERALLY KEEP MAX TEMPS IN THE LOW TO MID
50S OVER THE AREA.
THE LAST LEADING SHOWERS (FOR NOW) ARE MOVING EAST ACROSS THE NRN
BALTIMORE METRO. ONLY ISOLATED SHOWERS ARE EXPECTED AHEAD OF THE
COLD FRONT THROUGH THE MID-MORNING HOURS. THE COLD FRONT IS PROGGED
BY THE 06Z HRRR TO REACH THE POTOMAC HIGHLANDS IN THE MID-MORNING
HOURS. FORWARD PROGRESS WILL SLOW FROM THERE AS SHORTWAVE TROUGHS
SPREAD NORTHEAST UP THE PARENT UPR TROUGH. WIDESPREAD LIGHT RAIN IS
EXPECTED ACROSS THE AREA THIS AFTERNOON WITH QPF GENERALLY LESS THAN
TWO TENTHS INCH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
PERIODIC LIGHT RAIN WILL DRIFT SOUTH WITH THE FRONTAL BOUNDARY INTO
MONDAY. PERHAPS AN ADDITIONAL TENTH INCH RAIN...PARTICULARLY SOUTH
OF DC. NORTHWEST WINDS INCREASE TO AROUND 10 MPH TONIGHT WITH COLD
AIR ADVECTION RESULTING IN MIN TEMPS OF LOW 30S FOR NRN AND WESTERN
FRINGES...MID TO UPR 30S ELSEWHERE. RAIN ENDS AS SNOW FOR THESE
FRINGE AREAS NEAR THE MASON-DIXON LINE AND FOR RIDGES. NO SNOW
AMOUNTS WERE ADDED AS OF YET WITH LOW POPS...BUT THERE IS THE
POSSIBILITY OF A DUSTING...PARTICULARLY AT HIGH ELEVATIONS.
21Z SREF WAS EAGER TO HAVE HIGH POPS IN FOR MOST OF THE CWA THROUGH
MONDAY. HOWEVER...WENT WITH CONSENSUS OF NAM/GFS/ECMWF WITH HAVING
LIKELY POPS FOR RAIN LIMITED TO SRN MD MONDAY MORNING. LOW LEVEL
FLOW IS MORE NELY MONDAY AFTERNOON...WHICH WOULD PROMOTE CHANCE POPS
FOR RAIN/SNOW MIX OVER TERRAIN THE SWRN PART OF THE CWA. NO WINTRY
ACCUMULATION THERE EITHER WITH JUST CHANCE POPS.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
BASICALLY THE EXTENDED BOILS DOWN TO TWO PRECIP SYSTEMS AT THE START
AND END OF THE LONG TERM WITH COLD HIGH PRESSURE SANDWICHED IN BETWEEN.
MON AND MON NIGHT...STILL SOME UNCERTAINTY BASED ON MODEL SPREAD
OF PRECIPITATION FOR MON. 00Z/NAM AND GFS SOLNS SHOW MOST OF THE
PRECIP SLIPPING SOUTH AND EAST OF THE CWA EARLY MONDAY AM. BUT
00Z/ECMWF LINGERS SOME MOISTURE ACROSS SRN TIER OF ZNS. KEPT
SLIGHT TO CHANCE POPS IN FOR MON OVER THE CWA...AND WITH TEMPS
COLD ALOFT BUT BOUNDARY TEMPS ABOVE FREEZING...MENTIONED
RAIN/SNOW MIX POSSIBLE. BY MON NIGHT...LINGERING MOISTURE ACROSS
SOUTHERN TIER OF ZONES WARRANT CHANCE POPS...WITH LIKELY POPS IN
FAR SW PORTION OF CWA ACROSS HIGHLAND COUNTY AND SRN PENDLETON
COUNTIES...AND COLD ENOUGH THERE FOR ACCUMULATING SNOW AROUND AN
INCH IN UPSLOPE AREAS.
TUE...COLD AIR LOFT IS A CERTAINTY AS THE LARGE POLAR AIR MASS
SETTLES OVER MUCH OF THE CONUS EAST OF THE ROCKIES. THE 00Z/NAM
AND 03Z/SREF ARE AGAIN SHOW BEING AGGRESSIVE WITH A WEAK
DISTURBANCE THAT THE 00Z/GFS/ECMWF/UKMO SOLNS SHOW A MUCH WEAKER
AND FLATTER SYSTEM THAT STAYS SOUTH. AT THIS POINT ANY PRECIP
AMOUNTS TUE WILL BE LIGHT BUT COULD BE IN FORM OF SNOW.
WED-FRI...HIGH PRESSURE DOMINATES WITH SEASONABLY COLD WEATHER AND
DRY CONDITIONS.
LATE FRI-SAT...NEXT SYSTEM WILL APPROACH FROM THE SOUTHWEST AS
MODELS SHOW A LARGE LOW PRESSURE SYSTEM MOVING FROM THE CENTRAL
PLAINS LATE FRI MOVING INTO THE UPPER GREAT LAKES ON SAT. THIS
SYSTEM LOOKS LIKE IT COULD BRING A WINTRY MIX INITIALLY FRIDAY
NIGHT WITH THE EXPECTED TRACK OF THE LOW NORTHWEST OF THE CWA...
LOTS OF WARM AIR WILL BE ADVECTED INTO THE AREA...CHANGING PRECIP
TO LIQUID BY SAT MORNING. OF COURSE...TIMING AND POSITION AND
TRACK OF THE LOW IS LOW CONFIDENCE AT THIS POINT.
&&
.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
VFR CONDS THROUGH THE MORNING AS RAIN ASSOCIATED WITH A COLD FRONT
APPROACHES FROM THE OHIO VALLEY TODAY. MVFR CONDS THIS AFTERNOON IN
MAINLY LIGHT RAIN. FRONT STALLS/DRIFTS SOUTH TONIGHT...SO CONDS
CONTINUE TO LOWER WITH IFR POSSIBLE...BUT KEPT 06Z TAFS WITH MVFR
CIGS. LIGHT WLY FLOW TODAY...NWLY FLOW UP TO 10 KT TONIGHT...NLY
FLOW 10 KT MONDAY.
MVFR TO IFR CIGS/VSBYS MON AND MON EVENING. VFR CONDITIONS TUE
THROUGH THU...WITH POSSIBLE MVFR CIGS IN SNSH- ACTIVITY TUE.
&&
.MARINE...
LIGHT SWLY FLOW VEERS NWLY TODAY AS A COLD FRONT CROSSES THE WATERS
THIS AFTERNOON AND EVENING. COULD BE A NLY SURGE WITH GUSTS AROUND
18 KT LATE TONIGHT. DID NOT RAISE AN SCA DUE TO UNCERTAINTY...BUT
ONE OUT OF SANDY POINT IS POSSIBLE INTO MONDAY.
MON-WED...EXPECT WINDS TO REMAIN BELOW SCA LEVELS. PRECIP ON MON
PUSHES SOUTH AND EAST LATE MON. HIGH PRESSURE BUILDS IN TUE AND
CONTINUES THROUGH END OF THE WEEK.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...BAJ
NEAR TERM...BAJ
SHORT TERM...BAJ
LONG TERM...SMZ
AVIATION...BAJ
MARINE...BAJ/SMZ
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
610 PM EST MON DEC 29 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 403 PM EST MON DEC 29 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH
EXTENDING FROM NRN QUEBEC THROUGH THE NRN PLAINS INTO THE ROCKIES.
THE NEXT SIGNIFICANT UPSTREAM SHORTWAVE TROUGH WAS DROPPING SOUTH
THROUGH NRN SASK/MANITOBA. AT THE SFC...1054 MB ARCTIC HIGH PRES OVER
ALBERTA EXTENDED INTO THE NRN PLAINS AND UPPER MS VALLEY AND NRN
LAKES RESULTING IN A FLOW OF VERY COLD AIR ACROSS LAKE SUPERIOR ON
NW WINDS. DESPITE 850 MB TEMPS NEAR -21C...LES HAS BEEN LIMITED BY
THE VERY DRY UPSTREAM CONDITIONS AS THE BACK EDGE OF THE CLOUDS WAS
CLOSER TO THE MI SHORE IN THE WEST AND NEAR THE CENTER OF THE NRN
LAKE. RADAR SHOWED MAINLY WEAK WIND PARALLEL BANDS INTO THE ERN
CWA.
TONIGHT...WITH THE LOSS OF DAYTIME MIXING AND ONSET OF LAND BREEZES
THE LES MAY BECOME BETTER ORGANIZED. THE PERSISTENT 290-300 FLOW LES
IS EXPECTED TO CONTINUE BUT WILL BE LIMITED BY 4K FT INVERSION
HEIGHTS AND A LACK OF ANY SUSTAINED AREAS OF LOW LEVEL CONV. THE LONGER
FETCH INTO THE EAST WILL SUPPORT SNOWFALL AMOUNTS IN THE 2 TO 4 INCH
RANGE WITH SLR VALUES NEAR 25/1...E OF MUNISING WHILE OVER THE WEST
ONLY 1 TO 3 INCH AMOUNTS ARE EXPECTED. WIND CHILL VALUES OVER THE
INTERIOR WEST COULD FALL INTO THE -20 TO -25 RANGE AS SFC TEMPS DROP
TO AROUND -8F. HOWEVER...WINDS SHOULD REMAIN LESS THAN 10 MPH.
TUESDAY...EXPECT THE WINDS TO BACK MORE WRLY AHEAD OF THE
SASK/MANITOBA SHORTWAVE TROUGH...ESPECIALLY IN THE AFTERNOON.
OTHERWISE...LIGHT TO MODERATE WNW FLOW LES WILL CONTINUE WITH 850 MB
TEMPS REMAINING NEAR -22C AND INVERSION HEIGHTS AROUND 4K FT. THE
STRONGEST LOW LEVEL CONV...INFLUENCED BY LAKE-INDUCED TROUGHING IS
EXPECTED OVER THE ERN LAKE WITH SOME STRONGER BANDS POSSIBLE
CLIPPING THE NE PORTION OF LUCE COUNTY. FOR NOW...EXPECT ADDITIONAL
ACCUMULATIONS IN THE 2 TO 4 INCH RANGE E OF P53 AND 1 TO 3 INCHES
INTO THE WEST.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 426 PM EST MON DEC 29 2014
A BROAD UPPER TROUGH OVER CANADA AND THE GREAT LAKES REGION WILL
LEAD TO BELOW NORMAL TEMPERATURES AND PERIODS OF LAKE EFFECT SNOW
THROUGH THE FIRST WEEK OF 2015.
AT THE START OF THE PERIOD...THE AREA WILL STILL BE BETWEEN A
STRONG HIGH OVER WESTERN NEBRASKA AND A LOW JUST TO THE NORTH OF
HUDSON BAY. ALOFT...A SHORTWAVE WILL JUST BE DEPARTING THE AREA AND
BRINGING ONE LAST SURGE OF -21C 850MB TEMPS TO THE AREA.
THUS...EXPECT NORTHWEST FLOW LAKE EFFECT TO STILL BE ONGOING
TUESDAY EVENING. A SURFACE TROUGH DIVING SOUTHEAST FROM THE HUDSON
BAY LOW WILL LEAD TO BACKING FLOW ON TUESDAY NIGHT INTO WEDNESDAY
MORNING...SHIFTING THE LAKE EFFECT TO THE WESTERLY FLOW AREAS (THE
KEWEEANW AND RIGHT ALONG THE LAKE SUPERIOR SHORELINE EAST OF
MUNISING). SNOWFALL AMOUNTS TUESDAY NIGHT CONTINUE TO LOOK LIGHT
AND FLUFFY AS INVERSION HEIGHTS ARE STILL IN THE 4-5KFT RANGE WITH
MUCH OF THE CLOUD LAYER IN THE DGZ. WILL FOLLOW THE SNOWFALL
AMOUNTS SEEN OVER THE LAST 12/24HRS AND HAVE THEM BE IN THE
1-4IN/12HRS RANGE.
TUESDAY NIGHT WILL BE ANOTHER COLD NIGHT AWAY FROM THE LAKE EFFECT
CLOUDS...WITH LOWS FALLING INTO THE SINGLE DIGITS AND LOWER TEENS
BELOW ZERO. WIND CHILLS WILL BECOME A CONCERN LATE IN THE NIGHT
INTO WEDNESDAY MORNING...AS THE WEST TO SOUTHWEST WINDS BEGIN TO
INCREASE WITH THE TIGHTENING PRESSURE GRADIENT. WHILE THIS WILL
LIKELY INCREASE MIXING AND IN TURN WARM TEMPS SLIGHTLY (HELPED BY
SOME MID CLOUDS MOVING IN)...THERE WILL STILL BE A PERIOD LATE
TUESDAY NIGHT INTO WEDNESDAY MORNING WHERE WIND CHILL VALUES WILL BE
IN THE -20 TO -30 DEGREE RANGE OVER THE INTERIOR LOCATIONS. WILL
CONTINUE TO MENTION THIS IN THE HWO AND AN ADVISORY MAY BEEN
NEEDED TOMORROW.
WITH THE LOW LEVEL WINDS TRYING TO BACK TOWARDS THE SOUTHWEST
DURING THE DAY WEDNESDAY...DID TRY TO SHOW BETTER TIMING ON THE
LAKE EFFECT SNOW. EXPECT IT TO TRY TO SHIFT OVER THE FAR NORTHERN
PART OF THE KEWEENAW BY MID DAY AND WELL OFFSHORE OVER THE
EAST. WINDS WILL BECOME QUITE GUSTY DURING THIS PERIOD...WITH MUCH
OF UPPER MICHIGAN EXPERIENCING GUSTS IN THE 25 TO 35MPH RANGE. BUT
OVER THE KEWEENAW PENINSULA AND CLOSER TO THE TIGHTER PRESSURE
GRADIENT...WOULD EXPECT GUSTS TO AT LEAST 40 MPH AND AT TIMES
45-50MPH. THESE WINDS COMBINED WITH THE FLUFFY LAKE EFFECT SEEN
OVER THE LAST COUPLE OF DAYS WILL LIKELY LEAD TO SIGNIFICANT
BLOWING SNOW DEVELOPING THROUGH THE DAY WEDNESDAY. THEN...AS STRONG
SHORTWAVE DIVES SOUTHEAST ACROSS THE UPPER GREAT LAKES REGION DURING
THE AFTERNOON AND THE SURFACE TROUGH DURING THE EARLY
EVENING...EXPECT WINDS TO SHIFT BACK TO THE WEST AND REFOCUS THE
LAKE EFFECT IN THE WESTERLY WIND AREAS. THINK THERE COULD BE A
PERIOD OF MODERATE SNOW AS THE WINDS TURN TO THE WEST...DUE TO
INVERSION HEIGHTS RISING TO 7KFT AND MUCH OF THE CLOUD STILL IN THE
DGZ. THERE ARE A COUPLE DOWNSIDES TO HIGHER SNOWFALL AMOUNTS (TIED
TO THE STRONG WINDS)...BUT THERE WILL STILL BE VERY POOR CONDITIONS
OVER THE KEWEENAW. FIRST...THE HIGH WINDS WILL LIMIT THE RESIDENCE
TIME OVER THE WESTERN LAKE AS THEY SHIFT TO THE WEST. SECOND...THE
STRONG WINDS WILL BREAK UP THE DENDRITES FROM THE FAVORABLE CLOUD
LAYER AND LEAD TO SMALLER/FRACTURED FLAKES. WHILE THIS WILL LIMIT
SNOWFALL AMOUNTS...IT WILL BE MORE EFFECTIVE AT REDUCING
VISIBILITIES AND WHEN COMBINED WITH THE BLOWING SNOW...WOULD EXPECT
VISIBILITIES BELOW 1/4 MILE AT TIMES LATE WEDNESDAY AFTERNOON INTO
WEDNESDAY NIGHT. WILL CONTINUE TO MENTION THESE POOR CONDITIONS FOR
THE KEWEENAW IN THE HWO.
EXPECT NORTHWEST FLOW LAKE EFFECT TO REESTABLISH ON THURSDAY FOR
AREAS DOWNSTREAM FROM LAKE SUPERIOR. ELSEWHERE IN THE U.P...MODELS
DIFFER IN THEIR SOLUTIONS ON POTENTIAL SHORTWAVES ZIPPING
EAST-SOUTHEAST ACROSS THE AREA. AT TIMES...MODELS HAVE SHOWN LIGHT
SNOW ASSOCIATED WITH THESE QUICK WAVES THURSDAY AND AGAIN FRIDAY.
BOTH STRENGTH AND LOCATIONS HAS NOT BEEN CONSISTENT IN THE MODELS
OVER THE LAST 24 HOURS...SO WILL FOCUS LARGELY ON LAKE EFFECT
TURNING TO THE WESTERLY WIND LOCATIONS AND SHOW SLIGHT CHANCES
ELSEWHERE.
THE UNCERTAINTY CONTINUES INTO THE WEEKEND...AS MODELS DIFFER ON HOW
THE CLOSED UPPER LOW THAT DEVELOPS OVER THE SOUTHWEST CONUS TUESDAY
INTERACTS WITH THE NORTHERN STREAM JET AS IT SHIFTS EAST ACROSS THE
SOUTHERN CONUS. THE 12Z GFS/GEM SOLUTIONS MERGE THE UPPER LOW WITH
A MORE AMPLIFIED NORTHERN STREAM TROUGH AND THEN LIFT IT AND A
DEVELOPING SURFACE LOW NORTHEAST THROUGH THE LOWER GREAT LAKES
SATURDAY NIGHT. MEANWHILE...THE 12Z ECMWF AND ITS ENSEMBLE MEMBERS
SHOW A MUCH FLATTER NORTHERN STREAM TROUGH AND DON/T MERGE THE
WAVES UNTIL THE EAST COAST ON SUNDAY. THAT WOULD LEAD TO MORE OF A
NORTHERLY FLOW LAKE EFFECT FOR THE AREA. THIS WILL DEFINITELY BE
SOMETHING TO WATCH OVER THE COMING DAYS. EVEN IF THERE ISN/T A LOW
MOVING THROUGH THE LOWER GREAT LAKES...TEMPERATURES WILL BE COLD
ENOUGH FOR LAKE EFFECT SNOW AND WILL CONTINUE TO SHOW THE POTENTIAL
IN THE GRIDS FOR AREAS NEAR LAKE SUPERIOR.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 609 PM EST MON DEC 29 2014
EXPECT MAINLY MVFR CONDITIONS AT IWD/CMX THROUGH THE PERIOD...WITH
BETTER CONDITIONS AT SAW.
COLD AIR ON NORTHWEST WINDS OVER THE RELATIVELY WARM LAKE SUPERIOR
WATERS WILL KEEP LES GOING AT IWD AND CMX. ANOTHER UPPER LEVEL
DISTURBANCE HELPS BOOST THE POTENTIAL FOR LAKE EFFECT SNOW SHOWERS
AT CMX ONCE AGAIN. AT THAT POINT WINDS OVER N WI AND FAR W UPPER MI
SHOULD BECOME MORE WRLY...LIMITING POTENTIAL FOR MUCH MORE THAN
FLURRIES AT IWD OVERNIGHT.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 403 PM EST MON DEC 29 2014
EXPECT HEAVY FREEZING SPRAY BY TUESDAY AFTERNOON AND GALES FROM LATE
TUESDAY NIGHT THROUGH THURSDAY MORNING.
A RIDGE ACROSS THE UPPER GREAT LAKES WILL BUILD TUESDAY...AS VERY
STRONG ARCTIC HIGH PRESSURE INITIALLY AT 31.3 INCHES OVER SW CANADA
SINKS ACROSS MONTANA. LOOK FOR THE RIDGE OVER LAKE SUPERIOR TO SINK
SOUTH TUESDAY NIGHT. THIS WILL BE AS A HUDSON BAY LOW DRAGS A TROUGH
ACROSS LAKE SUPERIOR. THE LOW WILL DEEPEN OVER S HUDSON BAY
WEDNESDAY NIGHT AS IT BRINGS A REINFORCING TROUGH ACROSS LAKE
SUPERIOR. W GALES OF 35-45KTS ARE STILL ANTICIPATED /ALONG WITH
HEAVY FREEZING SPRAY TUESDAY NIGHT THROUGH THURSDAY MORNING AS
THE PRESSURE GRADIENT TIGHTENS BETWEEN THE EXITING HIGH TO THE S AND
STRONG LOW TO THE N. LOOK FOR THE LOW TO SHIFT ACROSS N QUEBEC AND
WEAKEN SIGNIFICANTLY THURSDAY NIGHT. HIGH PRESSURE WILL THEN BUILD
SE ACROSS SASKATCHEWAN AND S MANITOBA ON THURSDAY AND FRIDAY AS A
RIDGE TRACKS ACROSS THE UPPER GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING FROM 1 PM EST /NOON CST/ TUESDAY TO
1 PM EST /NOON CST/ THURSDAY FOR LSZ240>245-248>251-263-
265>267.
GALE WARNING FROM 1 AM WEDNESDAY TO 1 PM EST THURSDAY FOR
LSZ264>267.
HEAVY FREEZING SPRAY WARNING FROM 7 PM EST /6 PM CST/ TUESDAY TO
7 AM EST /6 AM CST/ THURSDAY FOR LSZ162.
GALE WARNING FROM 1 AM EST /MIDNIGHT CST/ WEDNESDAY TO 7 AM EST
/6 AM CST/ THURSDAY FOR LSZ162-263.
HEAVY FREEZING SPRAY WARNING FROM 1 AM TUESDAY TO 1 PM EST
THURSDAY FOR LSZ264.
GALE WARNING FROM 1 AM EST /MIDNIGHT CST/ TO 7 PM EST /6 PM CST/
WEDNESDAY FOR LSZ241>245.
HEAVY FREEZING SPRAY WARNING FROM 1 AM WEDNESDAY TO 1 PM EST
THURSDAY FOR LSZ246-247.
LAKE MICHIGAN...
HEAVY FREEZING SPRAY WARNING FROM 10 AM WEDNESDAY TO 1 PM EST
THURSDAY FOR LMZ221-248-250.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
435 PM EST SUN DEC 28 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 216 PM EST SUN DEC 28 2014
PERSISTENT LIGHT AND FLUFFY LAKE EFFECT IN THE NORTHWEST WIND SNOW
BELTS WILL BE THE NORM FOR THE SHORT TERM FORECAST.
A SURFACE TROUGH SWEPT SOUTHEAST ACROSS UPPER MICHIGAN THIS
MORNING AND EARLY AFTERNOON AND HAS SWITCHED WINDS TO THE NORTHWEST
AND BROUGHT MUCH COLDER AIR INTO THE AREA. 850MB TEMPS AT THIS TIME
ON THE RAP ANALYSIS ARE -18C OVER WESTERN LAKE SUPERIOR AND WESTERN
UPPER MICHIGAN. THIS COLD AIR...AIDED BY MOISTURE FROM THE SURFACE
TROUGH THAT SWEPT THROUGH THE AREA...LED TO SOME LAKE EFFECT SNOW IN
THE WEST AND NOW NORTHWEST WIND SNOWBELTS THROUGH THE DAY. WHILE
THERE WERE SOME STRONGER SHOWERS THIS MORNING...ASSISTED BY
CONVERGENCE ALONG THE FRONT AND FROM THE SOUTHERN EDGE OF THE
SHORTWAVE MOVING EAST JUST TO THE NORTH OF LAKE SUPERIOR...THEY HAVE
NOW TRANSITIONED TO MORE OF A MULTIBAND LES LOOK ON SATELLITE OVER
WESTERN UPPER MICHIGAN. USING THE EXPERIMENTAL SSEC SATELLITE
DERIVED SNOWFALL RATES...IT APPEARS THAT SOME AREAS ARE SEEING
TRANSIENT BANDS OF 0.5 IN/HR RATES AND THAT SEEMS TO MATCH UP WITH
VISIBILITY REPORTS AT KCMX. WITH THE DEEPER MOISTURE STARTING TO
PULL OUT OF THAT AREA...HAVE ALREADY SEEN SOME WEAKENING OVER
WESTERN LAKE SUPERIOR...HELPED BY INVERSION HEIGHTS FALLING
BEHIND THE TROUGH. THE 12Z KINL SOUNDING HAD INVERSION HEIGHTS
AROUND 900MB OR 3KFT...BUT WITH SOME LAKE MODIFICATION THEY SHOULD
BE IN THE 4-5KFT RANGE. OVER THE EAST...THERE WAS A STRONGER BAND
BETWEEN MUNISING AND MINER/S CASTLE THIS MORNING THAT LIKELY
PRODUCED A COUPLE-FEW INCHES OF SNOW. THIS BAND WAS AIDED BY THE
CONVERGENT FLOW OFF MARQUETTE COUNTY AHEAD OF THE SURFACE TROUGH.
BUT NOW THAT THE TROUGH IS MOVING THROUGH NORTH CENTRAL UPPER
MICHIGAN...THE BAND HAS BECOME MUDDLED. WITH THE LAKE EFFECT
TRANSITIONING TO MULTIBAND OVER THE EASTERN LAKE...ACCUMULATIONS
SHOULD BE LIMITED THE REST OF THE AFTERNOON.
OVERALL...LITTLE CHANGE IN THE OVERALL CONDITIONS OVER THE CWA
DURING THE SHORT TERM PERIOD...AS HIGH PRESSURE RIDGE BUILDS OVER
THE AREA FROM A STRONG HIGH IN NORTHWEST CANADA. WITH 875MB TEMPS
FALLING TO -21C...EXPECT HIGH POP LOW QPF LAKE EFFECT TO CONTINUE
THROUGH THE PERIOD IN THE NORTHWEST WIND SNOWBELTS. THERE DOES
APPEAR TO BE A BRIEF PERIOD OF BACKING WINDS OVERNIGHT AS A WEAK
TROUGH MOVES THROUGH TONIGHT BEFORE SETTLING BACK TO NORTHWEST WINDS
FOR MONDAY. THIS WEAK TROUGH WILL BRING A LITTLE MORE LOW LEVEL
MOISTURE TO THE AREA FOR THE LAKE EFFECT TO WORK WITH LATE TONIGHT
INTO MONDAY MORNING (SEEN ON THE 12Z CWPL SOUNDING). BUT THE RIDGE
MOVING OVER THE AREA WILL KEEP THE LOWER INVERSION HEIGHTS IN PLACE
THROUGH THE PERIOD AND KEEP SNOWFALL AMOUNTS IN CHECK. FOR TONIGHT
AND AGAIN ON MONDAY...HAVE THE NORTHWEST WIND SNOW BELTS RECEIVING
1-3 INCHES OF FLUFFY SNOW EVERY 12 HOURS...LARGELY HELPED BY THE
ENTIRE CLOUD BEING WITHIN THE DGZ. WITH THE LONGER FETCH AND IN TURN
LAKE MODIFICATION...HAVE A LITTLE HIGHER AMOUNTS OVER THE EAST BUT
STILL ONLY LOCALIZED 4 INCH AMOUNTS. THERE ARE SOME INDICATIONS OF
LOW LEVEL DRYING LATE TOMORROW AFTERNOON WHICH COULD WEAKEN THE LAKE
EFFECT SOME AND HAVE LOWERED THE POPS A LITTLE TO ACCOUNT FOR THAT.
AS IS NORMALLY THE CASE IN THE LAKE EFFECT REGIMES...LOWS TONIGHT
WILL DEPEND ON CLOUD COVER. WHERE CLEARING IS EXPECTED TO
OCCUR...HAVE LOWS IN THE SINGLE DIGITS ABOVE/BELOW ZERO.
OTHERWISE...UNDER THE CLOUDS WOULD EXPECT TEMPS IN THE UPPER SINGLE
DIGITS OR LOWER TEENS. HIGHS TOMORROW WILL BE CLOSE TO 10 DEGREES
BELOW NORMAL AND IN THE TEENS ABOVE ZERO.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 434 PM EST SUN DEC 28 2014
TODAYS MEDIUM RANGE MODELS STRONGLY SUPPORT LONG TERM FCST PRODUCED
OVER THE LAST 3 DAYS. SO...FCST CHANGES IN THE LONG TERM TODAY WILL
BE MINOR. BIGGEST FCST CHALLENGE WILL OCCUR AT THE END OF THE
WEEK/WEEKEND. MORE ON THAT LATER. THE LONG ADVERTISED SIGNIFICANT
PATTERN CHANGE ACROSS NAMERICA IS NOW WELL UNDERWAY AS A STRONG
RIDGE IS BUILDING N THRU ALASKA. 12Z RAOBS SHOW 12HR 500MB HEIGHT
RISES OF 130-150M IN NRN ALASKA/ADJACENT FAR NW CANADA...AND HEIGHT
ANOMALIES ARE NOW 2 STANDARD DEVIATIONS ABOVE THE LONG TERM LATE DEC
AVG. 500MB HEIGHT ANOMALIES ARE STILL FCST TO PEAK AT 2.5 STANDARD
DEVIATIONS LATER TODAY THRU EARLY WED. OF COURSE...THE DOWNSTREAM
RESPONSE WILL BE A DEVELOPING CNTRL/ERN NAMERICA TROF. THIS
AMPLIFIED PATTERN WILL ALLOW THE BUILDUP AND EXPANSION OF ARCTIC AIR
ACROSS CANADA THAT WILL SPILL S INTO THE CONUS...SIMILAR TO THE
PATTERN OBSERVED MOST OF LAST WINTER AND LAST MONTH. SO...AFTER AN
EXTENDED PERIOD OF MOSTLY ABOVE NORMAL TEMPS OVER THE LAST 3
WEEKS...A BLO NORMAL TEMP REGIME WILL TAKE HOLD ON MON AND CONTINUE
THRU AT LEAST THE NEXT 10 DAYS...THOUGH A DAY OR TWO MAY SEE TEMPS
CLOSE TO NORMAL DURING THAT TIME. THERE ARE INDICATIONS THAT THE
MOST SIGNIFICANT CHILL COULD OCCUR IN THE 7-10 DAY TIME FRAME.
FARTHER OUT TO DAY 16...MAJORITY OF GEM ENSEMBLES STILL INDICATE
DEAMPLIFICATION AND A TREND BACK TOWARD NORMAL TEMPS BY MID JAN.
CFSV2 GOES FURTHER TO BRING A RETURN OF A WARM PATTERN/ABOVE NORMAL
TEMPS FOR MID/LATE JAN. WE`LL SEE. AS FOR PCPN...PCPN THIS WEEK WILL
BE CONFINED ALMOST EXCLUSIVELY TO THE LAKE EFFECT SNOW BELTS NEAR
LAKE SUPERIOR AS COLD NW FLOW PREVAILS. AS HAS BEEN THE CASE THE
LAST FEW DAYS...THERE CONTINUE TO BE INDICATIONS THAT A LOW PRES
SYSTEM COULD TRACK FROM THE SRN PLAINS TO THE GREAT LAKES LATE
WEEK/WEEKEND. WHILE THIS STILL SEEMS LIKE A LOW PROBABILITY BASED ON
ALL AVBL MEDIUM RANGE GUIDANCE (AT LEAST AS FAR AS BRINGING
SIGNIFICANT PCPN INTO UPPER MI)...THERE ARE SUBTLE MULTI-MODEL
TRENDS SUPPORTING AN INCREASED LIKELIHOOD OF AT LEAST WIDESPREAD
-SN...INCLUDING LAKE ENHANCEMENT NEAR LAKE SUPERIOR. LATE
WEEK/WEEKEND WILL CONTINUE TO BE A TIME FRAME TO MONITOR IN THE
COMING DAYS.
BEGINNING MON NIGHT THRU TUE NIGHT...THE COLDEST AIR OF THIS INITIAL
SURGE OF ARCTIC AIR WILL SETTLE OVER THE AREA ON TUE WHEN 850MB
TEMPS BOTTOM OUT AROUND -23C. THIS WILL RESULT IN TUE LIKELY BEING
THE COLDEST DAY THIS WEEK FOR MOST AREAS. MAX TEMPS IN GENERAL WILL
BE IN THE 5 TO 15F RANGE...THOUGH OVER THE FAR W AROUND KIWD...TEMPS
MAY ONLY RISE TO JUST ABOVE 0F. MON NIGHT AND TUE NIGHT...SUBZERO
MIN TEMPS WILL BE THE RULE IN THE INTERIOR AWAY FROM LAKE EFFECT
CLOUDS/SNOW. TUE NIGHT WILL LIKELY BE COLDEST WITH TEMPS IN THE
INTERIOR W HALF SLIPPING TO -10F OR LWR. SUBZERO TEMPS SHOULD COVER
A WIDER AREA ON TUE NIGHT AS WELL SINCE WINDS BACKING MORE WESTERLY
WILL RESULT IN LESS LAKE EFFECT CLOUDS/SHSN COVERAGE OVER UPPER MI.
COMBINED WITH SOME INCREASE IN WINDS...WIND CHILLS WILL DROP INTO
THE -15 TO -25F RANGE TUE NIGHT INTO WED MORNING. WITH SUCH COLD
AIR...NMRS SNOW SHOWERS WILL CONTINUE IN THE SNOW BELTS FAVORED BY
NW TO W WINDS. NAM/GFS FCST SOUNDINGS SHOW INVERSIONS AT 4-5KFT...SO
LES WILL OVERALL BE ON THE LIGHT SIDE (1-4IN/12HRS). HOWEVER...WHERE
FETCH ACROSS THE LAKE IS LONGEST...ALLOWING MOST LAKE MODERATION...
DGZ WILL DOMINATE THE CONVECTIVE LAYER...AND THIS MAY ALLOW FOR SOME
ADVY LEVEL SNOW ACCUMULATIONS...IN PARTICULAR WHERE LONGER FETCH AND
LOCALIZED ENHANCED CONVERGENCE WORK TOGETHER. SIMILAR TO THE LAST
FEW DAYS OF MODEL RUNS...SHORTWAVE TROF SWINGING ACROSS THE AREA ON
TUE WILL HAVE SOME IMPACT ON INCREASING MOISTURE DEPTH/RAISING
INVERSION HEIGHTS (FOR ROUGHLY 6HRS)...RESULTING IN AN INCREASE IN
LES COVERAGE/INTENSITY FOR A TIME. SO...DAYLIGHT HRS ON TUE PROBABLY
OFFER THE BEST POTENTIAL FOR LES TO PRODUCE ADVY LEVEL ACCUMULATIONS
IN THE SNOW BELTS FAVORED BY NW WINDS.
ON NEW YEARS EVE DAY...LOW-LEVEL WINDS WILL BACK TO THE WSW OR EVEN
SW IN RESPONSE TO THE NEXT SHORTWAVE TROF SWINGING SE THRU MANITOBA
INTO NRN ONTARIO. THIS WILL CAUSE LES TO SHIFT OFFSHORE OF UPPER MI.
HOWEVER...UP AT 850MB...WINDS REMAIN OUT OF THE W. SO...LES WILL
LIKELY CONTINUE TO AFFECT THE KEWEENAW PENINSULA. TIGHTENING PRES
GRADIENT BTWN HIGH PRES OVER THE CNTRL/SRN PLAINS AND LOW PRES OVER
HUDSON BAY WILL RESULT IN INCREASING SFC WINDS...ESPECIALLY OVER THE
EXPOSED KEWEENAW WHERE 950MB WINDS ARE FCST AT 35-40KT. BLSN MAY
BECOME AN ISSUE THERE ON NEW YEARS EVE...ESPECIALLY IF SHSN COVERAGE
REMAINS NMRS OR GREATER.
NEXT ARCTIC COLD FRONT ASSOCIATED WITH AFORMENTIONED SHORTWAVE TROF
SWINGING ACROSS NRN ONTARIO WILL THEN SWEEP ACROSS THE AREA EARLY ON
NEW YEARS DAY...ENHANCING LES FOR A TIME AND PROBABLY BRINGING AT
ISOLD/SCT -SHSN TO THE REMAINDER OF THE AREA.
LES WILL CONTINUE ON INTO FRI UNDER COLD AIR MASS...BUT THERE IS
INCREASING MODEL AGREEMENT THAT WINDS WILL BACK FRI AS HIGH PRES
RIDGE SLIPS E OF THE AREA AND PRES FALLS SPREAD OUT OVER THE PLAINS.
THE BACKING WINDS AND RESULTING DEVELOPING WAA/ISENTROPIC ASCENT
REGIME WILL ALLOW FOR A BAND OF -SN TO DEVELOP OVER THE NRN PLAINS
AND THEN STREAK E INTO THE UPPER LAKES...BUT PROBABLY NOT UNTIL FRI
NIGHT.
ON INTO SAT...MUCH WILL DEPEND ON EVOLUTION OF THE CLOSED LOW THAT
WILL BE OVER THE SW STATES MIDWEEK. THE GFS HAS BEEN VERY CONSISTENT
ON THE NW SIDE OF GUIDANCE IN TAKING THAT ENERGY INTO THE GREAT
LAKES REGION. FOR A NUMBER OF RUNS...IT HAS TRACKED A SFC LOW NE...
ROUGHLY ACROSS THE SE HALF OF LWR MI. THE 00Z ECMWF STARTED TO TREND
SLIGHTLY N AND W WITH TRACK...BUT THE 12Z RUN IS MUCH MORE
SUPPRESSED WITH THE LOW...A RESULT OF THE NE PACIFIC RIDGE BEING
LESS PRONOUNCED WHICH LEADS TO FLATTER DOWNSTREAM FLOW. THERE A FEW
MORE GEM ENSEMBLES SIMILAR TO THE GFS TODAY...BUT THEY ARE STILL A
DEFINITE MINORITY. MUCH WILL DEPEND ON THE STRUCTURE/AMPLITUDE OF
THE NE PACIFIC RIDGE...BUT AT THIS POINT...GIVEN TODAYS AND RECENT
DAYS MEDIUM RANGE GUIDANCE...THE PROBABILITY IS STILL VERY LOW FOR
THE SFC LOW TO TRACK FAR ENOUGH N AND W TO BRING SIGNIFICANT PCPN TO
THE FCST AREA. HOWEVER...AIDED BY NRN STREAM ENERGY...THERE SHOULD
BE SOME -SN ACROSS THE FCST AREA ON SAT ALONG WITH THE POTENTIAL FOR
LAKE ENHANCEMENT NEAR LAKE SUPERIOR. ARCTIC AIR WILL FLOW BACK INTO
THE UPPER LAKES ON SUN...RENEWING LES IN AREAS FAVORED BY NW WINDS.
COLDEST AIR OF THE SEASON COULD FOLLOW FOR MON/TUE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1250 PM EST SUN DEC 28 2014
A SURFACE TROUGH MOVING ACORSS CENTRAL UPPER MICHIGAN IS LEADING TO
A BRIEF BAND OF LIGHT TO ALMOST MODERATE SNOW NEARING KSAW AT THE
START OF THE TAF PERIOD. THIS WILL AFFECT THE SITE FOR THE FIRST
30-45 MINUTES AND THEN MOVE OFF TO THE EAST. BEHIND THE
TROUGH...NORTHWEST FLOW LAKE EFFECT IS TAKING SHAPE OVER WESTERN
LAKE SUPERIOR AND WILL BE THE MAIN ITEM OF CONCERN OVER THE NEXT 24
HOURS. OVERALL...WITH A STRONG INVERSION AROUND 4KFT ABOVE THE
SURFACE...DON/T EXPECT THE SNOW SHOWERS TO BECOME TOO STRONG AND
HAVE KEPT VISIBILITIES IN THE MVFR TO VFR RANGE AT KCMX/KIWD. LOW
LEVEL WINDS DO LOOK TO BACK SLIGHTLY TONIGHT AHEAD OF A WEAK
SURFACE TROUGH THAT WILL THEN SHIFT WINDS BACK TO THE NORTHWEST
AROUND DAYBREAK. THUS...HAVE KEPT VSBYS A LITTLE HIGHER AT KIWD
WITH THOSE BACKING WINDS. ONCE THAT WEAK TROUGH MOVES
THROUGH...WOULD THINK THAT LIGHT LAKE EFFECT WOULD MOVE BACK INTO
THE SITE. OTHERWISE...WITH THE UNFAVORABLE WIND DIRECTION FOR
KSAW...EXPECT THEM TO TRANSITION TO VFR THIS AFTERNOON AND REMAIN
THROUGH MUCH OF THE PERIOD (COULD SEE CEILINGS NEAR MVFR TOMORROW
MORNING BEHIND THE TROUGH).
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 216 PM EST SUN DEC 28 2014
AS THE SURFACE TROUGH THAT SLID SOUTHEAST ACROSS LAKE SUPERIOR THIS
MORNING CONTINUES SOUTHEAST THROUGH THE LOWER GREAT
LAKES...PERSISTENT NORTHWEST WINDS OF 15-25KTS ARE EXPECTED OVER
THE LAKE THROUGH TUESDAY. THIS IS DUE TO THE AREA BEING BETWEEN A
STRONG HIGH MOVING INTO THE NORTHERN/CENTRAL PLAINS AND A LOW NEAR
HUDSON BAY. A SURFACE TROUGH WILL SWEEP ACROSS LAKE SUPERIOR ON
WEDNESDAY NIGHT AND TIGHTEN THE PRESSURE GRADIENT ACROSS THE LAKE.
THIS IS EXPECTED TO PRODUCE WESTERLY GALES OF 35-40KTS WEDNESDAY
INTO THURSDAY MORNING.
WITH MUCH COLDER TEMPERATURES MOVING OVER LAKE SUPERIOR OVER THE
NEXT SEVERAL DAYS...FREEZING SPRAY IS POSSIBLE FOR MUCH OF THE
PERIOD. WITH THE STRONGER WINDS TUESDAY NIGHT INTO THURSDAY...HEAVY
FREEZING SPRAY IS EXPECTED OVER MUCH OF THE LAKE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...ROLFSON
AVIATION...SRF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
216 PM EST SUN DEC 28 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 216 PM EST SUN DEC 28 2014
PERSISTENT LIGHT AND FLUFFY LAKE EFFECT IN THE NORTHWEST WIND SNOW
BELTS WILL BE THE NORM FOR THE SHORT TERM FORECAST.
A SURFACE TROUGH SWEPT SOUTHEAST ACROSS UPPER MICHIGAN THIS
MORNING AND EARLY AFTERNOON AND HAS SWITCHED WINDS TO THE NORTHWEST
AND BROUGHT MUCH COLDER AIR INTO THE AREA. 850MB TEMPS AT THIS TIME
ON THE RAP ANALYSIS ARE -18C OVER WESTERN LAKE SUPERIOR AND WESTERN
UPPER MICHIGAN. THIS COLD AIR...AIDED BY MOISTURE FROM THE SURFACE
TROUGH THAT SWEPT THROUGH THE AREA...LED TO SOME LAKE EFFECT SNOW IN
THE WEST AND NOW NORTHWEST WIND SNOWBELTS THROUGH THE DAY. WHILE
THERE WERE SOME STRONGER SHOWERS THIS MORNING...ASSISTED BY
CONVERGENCE ALONG THE FRONT AND FROM THE SOUTHERN EDGE OF THE
SHORTWAVE MOVING EAST JUST TO THE NORTH OF LAKE SUPERIOR...THEY HAVE
NOW TRANSITIONED TO MORE OF A MULTIBAND LES LOOK ON SATELLITE OVER
WESTERN UPPER MICHIGAN. USING THE EXPERIMENTAL SSEC SATELLITE
DERIVED SNOWFALL RATES...IT APPEARS THAT SOME AREAS ARE SEEING
TRANSIENT BANDS OF 0.5 IN/HR RATES AND THAT SEEMS TO MATCH UP WITH
VISIBILITY REPORTS AT KCMX. WITH THE DEEPER MOISTURE STARTING TO
PULL OUT OF THAT AREA...HAVE ALREADY SEEN SOME WEAKENING OVER
WESTERN LAKE SUPERIOR...HELPED BY INVERSION HEIGHTS FALLING
BEHIND THE TROUGH. THE 12Z KINL SOUNDING HAD INVERSION HEIGHTS
AROUND 900MB OR 3KFT...BUT WITH SOME LAKE MODIFICATION THEY SHOULD
BE IN THE 4-5KFT RANGE. OVER THE EAST...THERE WAS A STRONGER BAND
BETWEEN MUNISING AND MINER/S CASTLE THIS MORNING THAT LIKELY
PRODUCED A COUPLE-FEW INCHES OF SNOW. THIS BAND WAS AIDED BY THE
CONVERGENT FLOW OFF MARQUETTE COUNTY AHEAD OF THE SURFACE TROUGH.
BUT NOW THAT THE TROUGH IS MOVING THROUGH NORTH CENTRAL UPPER
MICHIGAN...THE BAND HAS BECOME MUDDLED. WITH THE LAKE EFFECT
TRANSITIONING TO MULTIBAND OVER THE EASTERN LAKE...ACCUMULATIONS
SHOULD BE LIMITED THE REST OF THE AFTERNOON.
OVERALL...LITTLE CHANGE IN THE OVERALL CONDITIONS OVER THE CWA
DURING THE SHORT TERM PERIOD...AS HIGH PRESSURE RIDGE BUILDS OVER
THE AREA FROM A STRONG HIGH IN NORTHWEST CANADA. WITH 875MB TEMPS
FALLING TO -21C...EXPECT HIGH POP LOW QPF LAKE EFFECT TO CONTINUE
THROUGH THE PERIOD IN THE NORTHWEST WIND SNOWBELTS. THERE DOES
APPEAR TO BE A BRIEF PERIOD OF BACKING WINDS OVERNIGHT AS A WEAK
TROUGH MOVES THROUGH TONIGHT BEFORE SETTLING BACK TO NORTHWEST WINDS
FOR MONDAY. THIS WEAK TROUGH WILL BRING A LITTLE MORE LOW LEVEL
MOISTURE TO THE AREA FOR THE LAKE EFFECT TO WORK WITH LATE TONIGHT
INTO MONDAY MORNING (SEEN ON THE 12Z CWPL SOUNDING). BUT THE RIDGE
MOVING OVER THE AREA WILL KEEP THE LOWER INVERSION HEIGHTS IN PLACE
THROUGH THE PERIOD AND KEEP SNOWFALL AMOUNTS IN CHECK. FOR TONIGHT
AND AGAIN ON MONDAY...HAVE THE NORTHWEST WIND SNOW BELTS RECEIVING
1-3 INCHES OF FLUFFY SNOW EVERY 12 HOURS...LARGELY HELPED BY THE
ENTIRE CLOUD BEING WITHIN THE DGZ. WITH THE LONGER FETCH AND IN TURN
LAKE MODIFICATION...HAVE A LITTLE HIGHER AMOUNTS OVER THE EAST BUT
STILL ONLY LOCALIZED 4 INCH AMOUNTS. THERE ARE SOME INDICATIONS OF
LOW LEVEL DRYING LATE TOMORROW AFTERNOON WHICH COULD WEAKEN THE LAKE
EFFECT SOME AND HAVE LOWERED THE POPS A LITTLE TO ACCOUNT FOR THAT.
AS IS NORMALLY THE CASE IN THE LAKE EFFECT REGIMES...LOWS TONIGHT
WILL DEPEND ON CLOUD COVER. WHERE CLEARING IS EXPECTED TO
OCCUR...HAVE LOWS IN THE SINGLE DIGITS ABOVE/BELOW ZERO.
OTHERWISE...UNDER THE CLOUDS WOULD EXPECT TEMPS IN THE UPPER SINGLE
DIGITS OR LOWER TEENS. HIGHS TOMORROW WILL BE CLOSE TO 10 DEGREES
BELOW NORMAL AND IN THE TEENS ABOVE ZERO.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 431 AM EST SUN DEC 28 2014
THIS PERIOD WILL BE MARKED BY COLD CONDITIONS WITH PERSISTENT LES.
ON MONDAY THE LONGWAVE TROUGH WILL ENCOMPASS ALL BUT FL...STRETCHING
FROM FAR N CANADA THROUGH QUEBEC...AND A SECONDARY LOW ACROSS THE
PACIFIC NW. LOOK FOR PERSISTENT NW FLOW ALOFT WITH SEVERAL SMALL
DISTURBANCES KEEPING OFF AND ON LES GOING OVER W UPPER MI...AND
MAINLY E OF MUNISING ALONG LAKE SUPERIOR.
THE FIRST OF MANY SHORTWAVES WILL BE IMPACTING OUR LOCAL WEATHER
MONDAY...PUSHING ACROSS MN AND N MN MONDAY AFTERNOON...AND SINKING
ACROSS UPPER MI LATE MONDAY AFTERNOON-MONDAY NIGHT. DURING THIS TIME
850MB TEMPS WILL ALSO DROP A COUPLE OF DEGREES C TOO FROM AN
AVERAGE -18 TO -20.
KEEPING THE THEME GOING...THE BACK EDGE OF THE 500MB TROUGH WILL
TIGHTEN TO OUR NW ON TUESDAY IN RESPONSE TO THE N CANADIAN TROUGH
SINKING/EXTENDING ACROSS E HUDSON BAY. THIS SHOULD BASICALLY ACT TO
DOUBLE THE AMOUNT OF SNOW PLACES FAVORED BY THE NW WINDS...LIKE CMX
WOULD HAVE OTHERWISE RECEIVED EVERY 6HRS. 850MB TEMPS WILL COOL
ANOTHER COUPLE DEGREES C TO AROUND -22 BY 00Z WEDNESDAY. IT WILL BE
A COLD DAY /SINGLE DIGITS TO MID TEENS/...FOLLOWED BY A COLD NIGHT.
WITH SOME CLEARING IS ANTICIPATED S CENTRAL AND ALONG THE WI BORDER
AS SFC WINDS BECOME MORE OUT OF THE W AND SW...-10C IS WELL WITHIN
REACH.
BRIEF WAA IS ANTICIPATED WEDNESDAY /NEW YEAR/S EVE/...WITH SNOW
SHOWERS PUSHING OFF MUCH OF THE S SHORES OF LAKE SUPERIOR ON WSW
WINDS. 850MB TEMPS SHOULD RISE TO AROUND -17C...OR EVEN WARMER
AROUND -14C OFF THE 28/00Z GFS. THERE REMAINS SOME DISCREPANCIES ON
THE TRACK/INTENSITY OF A SHORTWAVE THAT THE 27/00Z ECMWF HAS DIGGING
ACROSS S LOWER MI BY 00Z THURSDAY...RESULTING IN MORE CLOUD
COVER/LES SNOW AND COOLER CONDITIONS. THE GFS IS NOT TOO
IMPRESSIVE...KEEPING MUCH OF THE ACTIVITY N OF THE CWA. WILL GO WITH
A BLENDED/CONSENSUS SOLUTION FOR WEDNESDAY/WEDNESDAY NIGHT. BOTH THE
GFS AND ECMWF INDICATE 45-60KT 850MB WINDS WEDNESDAY INTO EARLY
THURSDAY...STRONGEST 18Z WEDNESDAY-12Z THURSDAY. OTHER THAN STRONG
WINDS ACROSS LAKE SUPERIOR AND PORTIONS OF THE MORE EXPOSED KEWEENAW
PENINSULA...IT IS UNKNOWN HOW MUCH OF THAT WILL BE ABLE TO MAKE IT
TO THE SFC. ALSO DURING THIS TIME THE 500MB LOW OVER THE PACIFIC NW
WILL HAVE SUNK ACROSS S CANADA...AND THE N LOW WILL HAVE SLID ACROSS
MUCH OF HUDSON BAY.
FRIDAY INTO SATURDAY LOOK A BIT MORE INTERESTING. THE GFS INDICATES
THAT WE LOSE THE STRONG INVERSION THAT/S BASICALLY BEEN SET UP
800-850MB....AND PLENTY OF MOISTURE IN A BROAD DGZ STRETCHING FROM
NEARLY 900-600MB. WILL BE INTERESTING TO WATCH THE EVOLUTION OF THIS
SYSTEM...WITH THE 500MB LOW IN THE SW PUSHING ACROSS THE S PLAINS
AND NUDGING A SFC LOW UP THE MS VALLEY...TO AROUND CENTRAL/S LOWER
MI BY 18Z SATURDAY...THEN RAPIDLY DEEPENING ACROSS S ONTARIO AND
QUEBEC SATURDAY NIGHT. THE 28/00Z HAS COME IN STRONGER AND FARTHER E
WITH THE LOW COMPARED TO THE GFS. INCREASED POPS A BUT FRIDAY NIGHT
GIVEN THE SOMEWHAT DECENT AGREEMENT...WITH FEW SIGNIFICANT CHANGES
OTHERWISE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1250 PM EST SUN DEC 28 2014
A SURFACE TROUGH MOVING ACORSS CENTRAL UPPER MICHIGAN IS LEADING TO
A BRIEF BAND OF LIGHT TO ALMOST MODERATE SNOW NEARING KSAW AT THE
START OF THE TAF PERIOD. THIS WILL AFFECT THE SITE FOR THE FIRST
30-45 MINUTES AND THEN MOVE OFF TO THE EAST. BEHIND THE
TROUGH...NORTHWEST FLOW LAKE EFFECT IS TAKING SHAPE OVER WESTERN
LAKE SUPERIOR AND WILL BE THE MAIN ITEM OF CONCERN OVER THE NEXT 24
HOURS. OVERALL...WITH A STRONG INVERSION AROUND 4KFT ABOVE THE
SURFACE...DON/T EXPECT THE SNOW SHOWERS TO BECOME TOO STRONG AND
HAVE KEPT VISIBILITIES IN THE MVFR TO VFR RANGE AT KCMX/KIWD. LOW
LEVEL WINDS DO LOOK TO BACK SLIGHTLY TONIGHT AHEAD OF A WEAK
SURFACE TROUGH THAT WILL THEN SHIFT WINDS BACK TO THE NORTHWEST
AROUND DAYBREAK. THUS...HAVE KEPT VSBYS A LITTLE HIGHER AT KIWD
WITH THOSE BACKING WINDS. ONCE THAT WEAK TROUGH MOVES
THROUGH...WOULD THINK THAT LIGHT LAKE EFFECT WOULD MOVE BACK INTO
THE SITE. OTHERWISE...WITH THE UNFAVORABLE WIND DIRECTION FOR
KSAW...EXPECT THEM TO TRANSITION TO VFR THIS AFTERNOON AND REMAIN
THROUGH MUCH OF THE PERIOD (COULD SEE CEILINGS NEAR MVFR TOMORROW
MORNING BEHIND THE TROUGH).
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 216 PM EST SUN DEC 28 2014
AS THE SURFACE TROUGH THAT SLID SOUTHEAST ACROSS LAKE SUPERIOR THIS
MORNING CONTINUES SOUTHEAST THROUGH THE LOWER GREAT
LAKES...PERSISTENT NORTHWEST WINDS OF 15-25KTS ARE EXPECTED OVER
THE LAKE THROUGH TUESDAY. THIS IS DUE TO THE AREA BEING BETWEEN A
STRONG HIGH MOVING INTO THE NORTHERN/CENTRAL PLAINS AND A LOW NEAR
HUDSON BAY. A SURFACE TROUGH WILL SWEEP ACROSS LAKE SUPERIOR ON
WEDNESDAY NIGHT AND TIGHTEN THE PRESSURE GRADIENT ACROSS THE LAKE.
THIS IS EXPECTED TO PRODUCE WESTERLY GALES OF 35-40KTS WEDNESDAY
INTO THURSDAY MORNING.
WITH MUCH COLDER TEMPERATURES MOVING OVER LAKE SUPERIOR OVER THE
NEXT SEVERAL DAYS...FREEZING SPRAY IS POSSIBLE FOR MUCH OF THE
PERIOD. WITH THE STRONGER WINDS TUESDAY NIGHT INTO THURSDAY...HEAVY
FREEZING SPRAY IS EXPECTED OVER MUCH OF THE LAKE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...KF
AVIATION...SRF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1134 PM EST SAT DEC 27 2014
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 235 PM EST SAT DEC 27 2014
A COLD FRONT WILL MOVE THROUGH THIS EVENING. COLDER AIR WILL
FOLLOW FOR THE REST OF THE WEEK WITH OCCASIONAL LAKE EFFECT SNOW
SHOWERS. NO BIG STORMS ARE EXPECTED THROUGH NEW YEARS.
&&
.UPDATE...
ISSUED AT 931 PM EST SAT DEC 27 2014
A SECONDARY SURFACE TROUGH WAS NOTED AT 02Z FROM ROUGHLY ALPENA
EXTENDING SW TO HARRISON AND LITTLE SABLE POINT. THIS FEATURE HAS
BEEN THE IMPETUS FOR LIGHT RAIN AND SNOW NORTH AND WEST OF GRAND
RAPIDS THIS EVENING DUE TO ENHANCED SURFACE CONVERGENCE.
CONVERGENCE CAN BE SEEN IN THE 02Z METARS WITH NORTHWEST WINDS AT
MBL AND CAD...WITH MORE WESTERLY FLOW FURTHER SOUTH. COLDER AIR IS
ALSO EVIDENT INLAND AND BEHIND THIS SURFACE TROUGH WITH 32 AT CAD
AND 33 AT HTL.
HAVE SLIGHTLY INCREASED POPS BETWEEN 04-09Z IN WESTERN COUNTIES
DUE TO DECENT LIFT IN THE CLOUD LAYER (MAINLY BELOW 5K FEET).
TEMPERATURES ARE NOT QUITE COLD ENOUGH FOR DENDRITIC GROWTH...BUT
AN ENHANCEMENT OF LIGHT MIXED PRECIP AND EVENTUALLY LIGHT SNOW IS
POSSIBLE OVERNIGHT. STILL THOUGH...NOT MUCH IN THE WAY OF
ACCUMULATIONS DUE TO WARM SURFACES AND AIR TEMPS REMAINING ABOVE
FREEZING AS OF 0230Z.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 235 PM EST SAT DEC 27 2014
SFC LOW AND COLD FRONT MOVE EAST WITH RAIN SHOWERS ENDING. KEPT A
SLIGHT CHANCE OF RAIN/SNOW SHOWERS THIS EVENING ACROSS THE
NORTHWEST FORECAST AREA WHICH COULD BE CLIPPED BY THE SOUTHERN
EDGE OF DEFORMATION ZONE PRECIP. THIS AREA COULD ALSO SEE SOME
LAKE EFFECT SNOW SHOWERS LATER TONIGHT INTO SUNDAY MORNING.
FLOW GOES NORTHWEST THIS EVENING WITH INVERSION HEIGHTS FALLING
BLO 5 KFT...SO SNOW SHOWERS SHOULD BE LIGHT. SNOW SHOWERS SHOULD
TAPER OFF SUNDAY MORNING AS DRYING AND SUBSIDENCE CONTINUE. SNOW
SHOWERS COULD FLARE UP A BIT SUNDAY NIGHT AS AN ARCTIC FRONT SAGS
SOUTH WITH SOME SFC CONVERGENCE HELPING THE CAUSE. THE FLOW GOES
MORE NORTHERLY ON MONDAY BEHIND THE FRONT...SO ANY SNOW SHOWERS
WILL BE CONFINED CLOSE TO THE COAST.
SNOW SHOWERS COULD BE MOVING FURTHER INLAND LATE MONDAY NIGHT AS
FLOW STARTS TO GO MORE NORTHWEST. INVERSION HEIGHTS ARE STILL AOB
5 KFT...SO ACCUMS WILL BE LIMITED.
.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 218 PM EST SAT DEC 27 2014
WE CONTINUE TO EXPECT A TREND TOWARD COLDER TEMPERATURES WITH CHCS
OF LAKE EFFECT SNOW SHOWERS THROUGH MUCH OF THE LONG TERM. WE WILL
THEN HAVE A CHC OF PCPN NEXT WEEKEND AS A STORM SYSTEM EJECTS FROM
THE SW PORTION OF THE COUNTRY.
NO REAL CHANGE TO THE TUE THROUGH THU TIMEFRAME WITH AN ARCTIC AIR
MASS COMING IN ALONG WITH CHCS OF LIGHT LAKE EFFECT SNOW SHOWERS.
THE RIDGE AXIS IN THE LOWER LEVELS WILL BE SHIFTING SOUTH OF THE
AREA BY TUE. THIS WILL TRANSITION THE MEAN LOW LEVEL FLOW TO THE NW
AND EVENTUALLY WEST. TEMPS AT H850 IN THE NEGATIVE TEENS C WILL BE
SUFFICIENT FOR LAKE EFFECT. THE LAKE EFFECT IS NOT EXPECTED TO BE
SIGNIFICANT AS THE NRN STREAM OF THE JET REMAINS NORTH...LEADING TO
LO INVERSION HEIGHTS AND SHALLOW MOISTURE. A COUPLE OF SHORT WAVES
WILL BE MOVING JUST NORTH OF THE CWFA TRYING TO HELP THE SNOW SHOWER
CHCS OUT.
IT LOOKS LIKE THE BRUNT OF THE SYSTEM THAT HAS BEEN SHOWN TO DEVELOP
IN THE MODELS FOR NEXT WEEKEND WILL MISS MOST OF THE CWFA FOR NOW.
THE TREND OVER THE PAST 24 HOURS IS FOR THE PARALLEL GFS AND EURO TO
SLOW THE EJECTION OF THE SW ENERGY AS EXPECTED. THIS ALLOWS THE NRN
STREAM OF THE JET TO MOVE IN AND SHUNT THE SRN STREAM SYSTEM TO THE
SE. PLENTY OF TIME FOR THE MODELS TO RESOLVE THE INTERACTION OF THE
TWO BRANCHES. FOR NOW WE WILL GO WITH A CHC OF SNOW AND FEATURE
COOLER TEMPS COMPARED TO THE WARMER AND MORE WET SOLUTIONS OF THE
PREVIOUS FEW DAYS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1132 PM EST SAT DEC 27 2014
MVFR CIGS PREVAIL ACROSS THE TAF SITES AT 0430Z. THERE IS A BAND
OF RAIN/SNOW SHOWER MOVING SOUTH NEAR I-96. THIS BAND ON SHOWERS
IS ASSOCIATED THE A SECONDARY COLD FRONT AND THIS FEATURE WILL MOVE
QUICKLY SOUTH AND EAST OUT OF THE AREA. IT IS FOLLOWED NICELY VIA
THE HRRR OVER THE PAST FEW HOURS OF RUNS. I HAVE TEMPO IFR SNOW
SHOWERS AT GRR AND AZO FOR THIS BUT ONLY MVFR AT BTL. AFTER THAT
MVFR CIGS WILL CONTINUE TILL MORNING. DRY AIR SHOULD CLEAR THE
SKIES BY MID TO LATE MORNING. THIS CLEARING IS MOVING INTO EASTERN
WISCONSIN NOW. ANOTHER WEAK COLD FRONT BRINGS MORE CLOUDS AND MAYBE
SNOW SHOWERS MONDAY NIGHT.
&&
.MARINE...
ISSUED AT 328 AM EST SAT DEC 27 2014
A SMALL CRAFT ADVISORY REMAINS IN EFFECT THROUGH 11 AM SUNDAY. WINDS
WILL VEER WEST TO 30 KNOTS THIS EVENING. WAVES WILL BUILD TO 4 TO
8 FEET NORTH OF HOLLAND AND 3 TO 5 FEET SOUTH OF HOLLAND. WEST
WINDS WILL VEER NORTHWESTERLY OVERNIGHT.
&&
.HYDROLOGY...
ISSUED AT 328 AM EST SAT DEC 27 2014
NO HYDRO ISSUES.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 11 AM EST SUNDAY FOR LMZ844>849.
&&
$$
UPDATE...EBW
SYNOPSIS...OSTUNO
SHORT TERM...OSTUNO
LONG TERM...NJJ
AVIATION...WDM
HYDROLOGY...EBW
MARINE...EBW
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
933 PM CST MON DEC 29 2014
.UPDATE...
EVENING SFC ANALYSIS INDICATES SFC HIGH PRESSURE BUILDING INTO OUR
AREA. HRRR INDICATES CLOUDS WILL SLOWLY ERODE FROM THE N TONIGHT AS
DRY AIR ADVECTION CONTINUES TO FILTER INTO OUR AREA. CLOUDS WILL
BEGIN TO DRY OUT AFTER MIDNIGHT AND SHOULD BE SLOWLY MOVING
TOWARDS/S OF THE I-20 CORRIDOR AFTER 12Z TUE. 00Z KLZK SOUNDING
INDICATES FALLING PW`S AROUND 0.3-0.4 INCHES. IN AREAS ALONG/SE OF
THE NATCHEZ TRACE WHERE DEWPOINTS WILL BE SLOWER TO FALL
OVERNIGHT...EXPECT SOME PATCHY FOG TO BE POSSIBLE AS MID/UPPER LEVEL
DRYING OVER THE THICK STRATUS DECK PROMOTES SOME STRATUS BUILDING
DOWN INTO FOG. GFS-LAMP GUIDANCE INDICATES THIS IDEA AND THUS ADDED
PATCHY FOG FROM 06Z-13Z. BUMPED UP LOWS A FEW DEGREES SE OF THE
TRACE. ADJUSTED TEMP/DEWPOINT/SKY GRIDS TO CURRENT TRENDS. REST OF
THE FORECAST IS ON TRACK. /DC/
&&
.AVIATION...MAINLY IFR TO LIFR FLIGHT CATS BEING EXPERIENCED AROUND
THE REGION THIS EVENING...MAINLY DUE TO LOW CEILINGS. VISIBILITIES
DUE TO DRIZZLE AND A BIT OF FOG ARE ALSO A BIT OF A CURRENT ISSUE
AROUND PORTIONS OF CENTRAL AND EASTERN MS. EXPECTING FLIGHT CATS TO
VERY GRADUALLY IMPROVE FROM NORTHWEST (GLH) TO SOUTHEAST (HBG) LATE
TONIGHT THROUGH MIDDAY TUESDAY. HOWEVER...LOCATIONS SUCH AS
HKS/JAN/NMM/MEI/GTR/CBM/PIB/HBG CAN STILL PROBABLY ANTICIPATE IFR
CEILINGS AT DAYBREAK WITH TANGIBLE IMPROVEMENT MAINLY WAITING UNTIL
AFTER THE SUN COMES UP. WINDS WILL RANGE FROM 5 TO 15 MPH FROM THE
NORTH OVERNIGHT...BUT BY MID TO LATE MORNING SHOULD RANGE FROM 10 TO
20 MPH. /BB/
&&
.PREV DISCUSSION... /ISSUED 305 PM CST MON DEC 29 2014/
SHORT TERM...FORECAST PROBLEMS FOR THIS TIME PERIOD WILL BE
PERSISTENT CLOUD DECK AND TEMP FORECAST TRANSITION WITH APPROACHING
ARTIC AIRMASS.
WHILE DEEP SW FLOW REMAINS IN PLACE OVER THE REGION...VEERING JUST A
FEW DEGREES HAS ALLOWED DEEP MOISTURE TO MOVE OUT. WEAKER FLOW IN
THE LAYER BELOW 800 MB HAS ALLOWED MOISTURE TO HANG AROUND. THAT
COMBINED WITH LOCALIZED COOLING HAS ALLOWED RESULTING ISENTROPIC
LIFT TO MAINTAIN CLOUD DECK AS WELL AS PRODUCE AREAS OF DRIZZLE THIS
MORNING. INCREASING PRESSURE GRADIENT IN THE LOWER LEVELS TONIGHT
WILL ALLOW FOR BETTER DOWNGLIDE AND SUPPORT A GRADUAL EROSION OF THE
CLOUD DECK FROM THE NW AS THE FRINGES OF THE MODIFIED ARCTIC BEGIN
TO IMPINGE ON THE AREA.
EXPECT CLEAR SKIES BY TUESDAY AFTERNOON...BUT MAX TEMPS SHOULD BE
SIMILAR TO TODAY IN INCREASED COLD AIR ADVECTION. STRONG MID/UPPER
LEVEL STORM SYSTEM WILL CONTINUE TO DIVE SOUTH ALONG THE PAC COASTAL
AREA AS SURFACE CENTER OF THE COLDER AIRMASS SETTLES OVER THE PLAINS
BY WEDNESDAY. OUR PERIOD OF CLEAR SKIES AND DRY WEATHER WILL BE SHORT
LIVED AS BACKING WINDS ALOFT BEGIN STREAMING MID/UPPER LEVEL CLOUDS
BACK INTO THE AREA WEDNESDAY NIGHT/THURSDAY./26/
LONG TERM...THE LENGTHY PERIOD OF TIME THE WESTERN STORM SYSTEM
WILL HAVE TAKEN BY THE TIME IT BEGINS TO IMPACT THE FORECAST AREA
WILL HAVE GIVEN THE COLD AIRMASS TIME TO MODIFY SUBSTANTIALLY FROM
WHAT IT WAS WHEN IT CAME THROUGH THE PLAINS. THUS...AM NOT EXPECTING
A PROBLEM WITH WINTRY PRECIPITATION AT THE ONSET. PRECIPITATION LOOKS
TO BEGIN AS LIGHT RAIN BY THURSDAY AFTERNOON AS WAA/ISENTROPIC ASCENT
RESUME. THIS LIGHT STRATIFORM PRECIP REGIME SHOULD CONTINUE THROUGH
THURSDAY NIGHT...BUT THINGS START CHANGING BY FRIDAY.
AS THE MID/UPPER SYSTEM PULLS INTO THE PLAINS OF KS/N TX FRIDAY
NIGHT/SATURDAY...SURFACE CYCLOGENESIS WILL GET UNDERWAY ALONG THE
UPPER TX COASTAL BAROCLINIC ZONE. THIS LOW WILL RAPIDLY MOVE INLAND
AND DRAG MID/UPPER 60S DEWPOINTS NORTHWARD TO AS FAR NORTH AS I20.
WHILE INSTABILITY WILL INITIALLY BE ELEVATED...SURFACE BASED
CONVECTION LOOKS PROBABLE BY SATURDAY AFTERNOON AS THE HIGH DEWPOINTS
ARE BROUGHT NORTH. AT PRESENT...THE GFS IS SHOWING CAPES OF 500-1500
J/KG AND SRH FROM 250-300 M2/S2 OVER THE SOUTHERN HALF OF THE
FORECAST AREA. WILL NEED TO MONITOR FUTURE MODEL RUNS CLOSELY TO SEE
IF THIS POSSIBLE SEVERE SIGNAL CONTINUES./26/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 39 51 29 47 / 3 0 0 3
MERIDIAN 39 53 27 49 / 3 0 0 2
VICKSBURG 36 49 29 45 / 3 0 0 3
HATTIESBURG 45 56 31 52 / 7 0 0 3
NATCHEZ 39 50 29 47 / 3 0 0 4
GREENVILLE 32 46 27 40 / 3 0 0 3
GREENWOOD 32 47 27 44 / 3 0 0 3
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
DC/BB/26
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
212 PM EST SUN DEC 28 2014
.SYNOPSIS...
A NORTHWEST FLOW OF COLD AIR WILL RETURN THE AREA TO MORE
SEASONABLE WEATHER THIS WEEK. AS THIS AIR CROSSES THE GREAT
LAKES IT WILL PICK UP SOME MOISTURE...SO A FEW LAKE EFFECT SNOW
SHOWERS AND FLURRIES ARE POSSIBLE...ESPECIALLY OVER CENTRAL NEW
YORK.
&&
.NEAR TERM /THROUGH TONIGHT/...
SOLID LL CLD DECK ALL THE WAY BACK INTO SW ONTARIO DESPITE THE NW
FLOW OF DRIER AIR. XPCTY CONTD SLOW IMPRMT OVER NGT AS INCRSGLY
DRIER AIR MVES INTO THE AREA. HRRR AND ARW DVLP SOME LGT LE LATE
TNGT AS THE WLY DVLPS A SINGLE BAND INTO NRN ONEIDA AND PERHAPS
XTRM NRN ONONDAGA. WITH MRGNL TEMPS AND WEAK LE XPCT ONLY TRACE
AMTS. DESPITE THE COND CAA...OVRNGT TEMPS STILL WILL END UP ABV
NRML FOR THE SEASON.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
CONTD WEAK LE EVENT PSBL WITH A SOMEWHAT SHEARED WNW FLOW AND MRGNL
INSTABILITY. ISLTD LGT SNOW SHWRS PSBL OVER THE HIGHER TERRAIN MON
AS HTG ADDS A BIT OF INSTBILITY OVER THE BARE GND. NAM FCST A WEAK
SFC LOW TO DVLP OVRNGT MON WHICH REALLY JUST DISRUPTS THE BNDRY
LYR FLOW WITHOUT ENHANCING THE LE.
LTL CHG FOR TUE OTR THAN SLGTLY COLDER AIR IN PLACE AND PERHAPS A
BIT BETTER ALIGNED LL FLOW. ALSO...HINT OF A SHRT WV MAY ENHANCE
THE INSTABILITY LATE IN THE DAY. FLOW CONTS TO FAVOR ANY ACTIVITY
TO BE OVER THE NRN THIRD OF THE FCST AREA.
BEST CHANCE FOR LE WILL BE WED AS THE CONTD CAA HAS BROUGHT THE
SNDG DEEPER INTO THE SNOW GROWTH ZONE AND FLOW BECOMES BETTER
ALIGNED. WRKG AGAINST SIGNIFICANT ACCUMS WILL BE A CONSTANTLY CHGG
MEAN FLOW AS A WV PASSES...AND YET ANOTHER APRCHS KICKING ANY BAND
THAT DVLPS NORTH OF THE FCST AREA.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
THE LONG TERM PERIOD BEGINS WITH A LARGE SCALE TROF ACROSS CENTRAL
AND EASTERN CANADA. A COOL NORTHWEST FLOW WILL BRING LAKE EFFECT
SNOW SHOWERS INTO NORTHERN NY INTO THURSDAY.
A STORM SYSTEM MOVING OUT OF THE SOUTH CENTRAL UNITED STATES WILL
SPREAD PRECIPITATION INTO NY/PA FRIDAY NIGHT. THE PRECIPITATION
MAY ARRIVE AS LIGHT SNOW WITH POCKETS OF FREEZING RAIN. HOWEVER,
ONCE THE WARM AIR PUSHES THROUGH THE REGION EARLY SATURDAY,
TEMPERATURES WILL RISE INTO THE 40S AND THE PRECIPITATION WILL
CHANGE TO RAIN.
GENERALLY FOLLOWED HPC GUIDANCE WITH ADJUSTMENTS FOR LAKE EFFECT
AREAS.
&&
.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
WIDESPREAD MVFR CEILINGS WILL RISE SLIGHTLY THIS EVENING. CEILINGS
OVERNIGHT ARE FORECAST TO RANGE FROM 2500 TO 4000 FEET, WITH
NORTH-NORTHWEST WINDS AROUND 7 TO 10 KNOTS.
SOME CLEARING IS POSSIBLE LATER MONDAY MORNING. THERE EXIST MODEL
DIFFERENCES WITH RESPECT TO AMOUNT OF LOW LEVEL MOISTURE. GFS
TRIES TO CLEAR SKIES OUT, WHEREAS NAM KEEPS MOISTURE LOCKED IN.
LEANING TOWARD GFS AT THE MOMENT.
OUTLOOK...
MON...VFR.
TUE/WED/THU...BRIEF RESTRICTIONS POSSIBLE AT TIMES FOR
KRME/KSYR...DUE TO LAKE EFFECT -SHSN. OTRWS...VFR IS EXPECTED.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DGM
NEAR TERM...DGM
SHORT TERM...DGM
LONG TERM...DJP
AVIATION...DJP
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
939 AM EST SUN DEC 28 2014
.SYNOPSIS...
HIGH PRESSURE WILL BE OVER THE AREA TONIGHT AND SUNDAY. A COLD
FRONT WILL MOVE THROUGH EASTERN NORTH CAROLINA SUNDAY NIGHT AND
MONDAY. HIGH PRESSURE WILL BE CENTERED IN THE VICINITY THROUGH THE
REMAINDER OF THE WEEK...WITH A COLD FRONT APPROACHING NEXT
WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 931 AM SUN...AREA OF LIGHT RAIN MOVING THROUGH THE COASTAL
PLAINS THIS MORNING. AREA APPEARS TO BE MOSTLY VIRGA WITH DRY LAYER
JUST ABOVE THE SURFACE...HOWEVER SOME STATIONS REPORTING LIGHT RAIN
REACHING THE GROUND. SATELLITE PIX AND OBSERVATIONS SHOWING SKIES
BECOMING MOSTLY CLOUDY WITH THICKER CLOUDS EXPECTED TO MOVE IN
THROUGH THE DAY. HRRR INDICATING LOW CHANCES OF PRECIPITATION
THROUGH THE DAY AS WEAK COASTAL TROUGH AND APPROACHING FRONT AFFECT
THE AREA.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
AS OF 330 AM SUNDAY...THE MODELS DIFFER SLIGHTLY ON THE TIMING OF
THE FRONT WITH THE NAM BEING THE QUICKEST TO PUSH IT THROUGH
OVERNIGHT SUNDAY NIGHT. FAVORED A BLEND OF THE GFS/ECMWF/SREF AND
PREVIOUS FCST FOR TIMING WHICH PUSHES THE FRONT TO ABOUT CAPE
LOOKOUT BY MONDAY MORNING. THE CHANCE OF RAIN RAMPS UP
TONIGHT...MOSTLY AFTER MIDNIGHT...BECOMING LIKELY TO CATEGORICAL
BY MONDAY MORNING AS THE FRONT AND SHORTWAVE CROSSES THE AREA.
LOWS SUNDAY NIGHT WILL BE MILD...IN THE UPPER 40S TO AROUND 50.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
AS OF 4 AM SUN...A COLD FRONT WILL PUSH OFFSHORE MON MORNING AND
STALL ACROSS THE OFFSHORE WATERS MON NIGHT AND TUES. BEST FORCING
AND LIFT OCCUR AFTER FROPA WITH OVERRUNNING MOISTURE AND HAVE
INCREASED POPS TO CATEGORICAL ALL BUT SOUTHERN COASTAL AREAS
THROUGH THE MORNING HOURS...THEN SHIFT TO SOUTHERN COASTAL AREAS
FOR THE AFTERNOON. QPF AMOUNTS WON`T BE TOO SIGNIFICANT...MAINLY
LESS THAN AN HALF INCH. WEAK CAA AND A STRENGTHENING FRONTAL
INVERSION ON MONDAY WILL MEAN A LOWERING OF CLOUDS AND WIDESPREAD
LIGHT RAIN AND TEMPS STRUGGLING TO RISE WITH HIGHS RANGING FROM THE
LOW/MID 50S NORTH TO UPR 50S SOUTH.
A STRONG POST FRONTAL INVERSION WITH ABUNDANT LOW LEVEL MOISTURE
CONTINUES MON NIGHT AND TUES AS WEAK LOW PRES DEVELOPS ALONG THE
STALLED FRONTAL BOUNDARY OFFSHORE CONTINUING TO BRING LOW CLOUDS
WITH PERIODS OF DRIZZLE OR LIGHT RAIN. DISCOUNTING THE NAM
SOLUTION THIS PERIOD AS IT IS AN OUTLIER DEVELOPING STRONG LOW
PRES AND MORE WIDESPREAD RAIN ACROSS THE REGION TUES. SHOULD BEGIN
TO SEE IMPROVING CONDITIONS LATE TUES/TUES NIGHT AS DRIER AIR
FILTERS IN WITH HIGH PRES BUILDING IN FROM THE WEST...HOWEVER THE
NAM IS SLOWER IN DOING SO WITH LOW CLOUDS HANGING IN THROUGH TUES
NIGHT. HIGHS TUES GENERALLY IN THE UPPER 40S/LOWER 50S.
HIGH PRES BUILDS ACROSS THE AREA WED THROUGH FRI BRINGING DRY
CONDITIONS AND SEASONABLY COOL CONDITIONS. WED WILL BE THE COOLEST
DAY THIS PERIOD WITH HIGHS IN THE MID TO UPPER 40S...THEN WILL SEE
THE AIRMASS GRADUALLY MODERATE THURS AND FRI WITH HIGHS IN THE
50S. LOWS WED AND THURS IN THE UPR 20S INLAND TO 30S COASTAL
SECTIONS. INCREASING CLOUD COVER EXPECTED TO HOLD MINS TO THE 30S
INLAND AND 40S COAST FRI.
00Z MODELS BEGINNING TO COME INTO BETTER AGREEMENT WITH THE LATE
WEEK SYSTEM DEVELOPING ACROSS THE SOUTHERN PLAINS AND GULF
STATES...AT LEAST TROUGH THE ONSET OF PRECIP LATE FRI INTO SAT.
HIGH PRES SLIDES OFFSHORE FRI NIGHT WITH A COLD FRONT
APPROACHING THE REGION SAT. WAA AND INCREASING MOISTURE COULD
BRING A FEW SHOWERS ACROSS THE REGION LATE FRI/FRI NIGHT WITH
INCREASING PRECIP CHANCES SAT. THE ECMWF IS MORE AMPLIFIED IN THE
MID LEVELS AND SUBSEQUENTLY FASTER PUSHING THE FRONT AND PRECIP
OFFSHORE SAT NIGHT WHILE THE GFS QUICKLY DAMPENS THE MID LEVEL
TROUGH WITH THE FRONT STALLING ACROSS THE REGION LATE IN THE
WEEKEND KEEPING PRECIP CHANCES IN THE FORECAST.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
SHORT TERM /THROUGH 06Z MONDAY/
AS OF 630 AM SUNDAY...HIGH CLOUDS OVER THE AREA WILL BEGIN TO
THICKEN AND LOWER THROUGH THE DAY AS MOISTURE STREAMS ACROSS THE
AREA AHEAD OF AN APPROACHING COLD FRONT. VFR CONDITIONS SHOULD
PREVAIL THROUGH MOST OF THE AFTERNOON...BECOMING MVFR IN THE
LATE AFTERNOON/EARLY EVENING AS CEILINGS LOWER. FOR THE MOST PART
MOST OF THE DAY WILL REMAIN DRY WITH POSSIBLY A FEW LIGHT SPOTTY
SHOWERS PUSHING INTO WESTERN AREAS LATE THIS AFTERNOON INTO THE
EVENING HOURS. THE BULK OF THE PRECIPITATION WILL HOLD OFF UNTIL
AROUND AND AFTER MIDNIGHT. EXPECT WIDESPREAD MVFR CONDITIONS THIS
EVENING AS SOME FOG DEVELOPS AS LOW LEVEL MOISTURE INCREASES TONIGHT
AND CEILINGS CONTINUE TO LOWER. BY AFTER MIDNIGHT IFR CONDITIONS
BECOME LIKELY ACROSS THE AREA AND RAIN WILL BECOME MORE WIDESPREAD
BY THE END OF THE TAF PERIOD.
LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 4 AM SUN...A COLD FRONT WILL PUSH EAST OF RTES EARLY MON
WITH OVERRUNNING MOISTURE CONTINUING TO BRING PERIODS OF RAIN WITH
SUB VFR CONDITIONS THROUGH THE MORNING. BULK OF THE PRECIP PROGGED
TO PUSH EAST OF THE TERMINALS MON AFTERNOON BUT EXEPCT IFR/LIFR
STRATUS WITH AREAS OF DRIZZLE AND POSSIBLY OCCASIONAL PERIODS OF
LIGHT RAIN CONTINUING INTO TUES. HIGH PRES BUILDS ACROSS THE AREA
WED AND THURS WITH VFR CONDITIONS DOMINATING.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/
AS OF 938 AM SUN...SOUTHWESTERLY FLOW OVER THE NORTH CAROLINA
COASTAL WATERS THIS MORNING AROUND 10 KNOTS OR LESS WITH SEAS 2 TO 4
FEET. FRONT TO THE WEST WILL APPROACH THE WATERS THROUGH THE DAY.
GRADIENT WILL TIGHTEN SOME AHEAD OF THE FRONT...BRINGING WINDS TO 10
TO 15 KNOTS DURING THE AFTERNOON.
PREV DISC...AS OF 630 AM SUNDAY...NO SIGNIFICANT CHANGES THIS
UPDATE. MODELS ARE IN PRETTY CLOSE AGREEMENT ON TIMING OF
APPROACHING COLD FRONTAL PASSAGE COMING LATE MONDAY NIGHT. THE NAM
WAS A BIT FASTER TO GET THE FRONT THROUGH THE ENTIRE AREA...BUT
FOLLOWED A SLIGHTLY SLOWER BLEND OF THE GFS/ECMWF/SREF AND PREVIOUS
FCST. SOUTHERLY FLOW WILL INCREASE TO AROUND 15 KT FOR THE COASTAL
WATERS AHEAD OF THE FRONT TODAY. THE FRONT WILL MOVE INTO THE
NORTHERN WATERS AFTER MIDNIGHT AND WILL BE DOWN NEAR CAPE LOOKOUT BY
EARLY MONDAY MORNING. WINDS WILL LESSEN AS THE FRONT MOVES THROUGH
THE AREA WITH A BIT OF A SURGE BEHIND THE FRONT COMING DURING THE
DAY MONDAY. UNTIL THEN SEAS WILL REMAIN AROUND 2 TO 4 FEET FOR MOST
OF THE WATERS. THE EXCEPTION MAY BE A SMALL AREA OF 5 FOOT SEAS IN
THE CENTRAL WATERS AROUND DIAMOND BUOY TONIGHT INTO SUNDAY BEFORE
THE FRONT MOVES INTO THE AREA AND SOUTHERLY WINDS LESSEN A BIT.
LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 4 AM SUN...A COLD FRONT WILL CONTINUE TO PUSH THROUGH THE
SOUTHERN WATERS MON MORNING WITH N/NE WINDS INCREASING TO 10-20 KT
AND SEAS BUILDING TO 3-5 FT ACROSS THE WATERS. THE FRONT IS
PROGGED TO STALL ACROSS THE OFFSHORE WATERS MON NIGHT INTO EARLY
TUES. WEAK LOW PRES DEVELOPS ALONG THE FRONT WITH STRONG HIGH
PRES BUILDING IN FROM THE WEST TUES ALLOWING N/NE WINDS TO
INCREASE TO 15-25 KT THROUGH TUES EVENING. SEAS BUILD TO 4-7 FT
NORTH OF OCRACOKE AND 3-6 FT SOUTH TUES/TUES NIGHT IN RESPONSE.
DISCOUNTING THE NAM SOLUTION TUES INTO WED AS IT IS AN OUTLIER
DEVELOPING STRONGER LOW OFF THE COAST WITH WINDS NEAR GALE FORCE
LATE TUES. WINDS AND SEAS GRADUALLY SUBSIDE LATE TUES NIGHT AND
WED AS HIGH PRES BUILDS IN FROM THE WEST. N WINDS AOB 15 KT WED
BECOMES WLY THURS. SEAS PROGGED TO SUBSIDE TO 2-5 FT WED AND 1-3
FT THURS.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...RSB
NEAR TERM...CGG
SHORT TERM...RSB
LONG TERM...SK
AVIATION...RSB/SK
MARINE...CGG/RSB/SK
AREA FORECAST DISCUSSION
NWS RALEIGH NC
340 AM EST SUN DEC 28 2014
.SYNOPSIS... A COLD FRONT WILL APPROACH FROM THE NORTHWEST TODAY...
THEN PUSH SLOWLY SOUTHEAST THROUGH THE AREA MONDAY AND MONDAY NIGHT.
HIGH PRESSURE WILL BUILD IN FROM THE WEST LATE TUESDAY THROUGH
THURSDAY.
&&
.NEAR TERM /TONIGHT THROUGH SUNDAY/...
AS OF 920 PM SATURDAY...
SATELLITE CLOUD TRENDS SUPPORT EARLIER EXPECTATIONS OF CLOUDS
OVERSPREADING CENTRAL NC FROM THE WEST AND SW... WITH CLOUDS
STEADILY THICKENING AND LOWERING OVERNIGHT. THIS IS EXHIBITED WELL
BY A COMPARISON OF THE 00Z GSO SOUNDING WITH UPSTREAM SOUNDINGS...
WITH DRY AIR NEAR 500 MB AND BELOW 700 MB AND A PW NEAR 0.6 IN AT
GSO... WHEREAS UPSTREAM LOCATIONS INCLUDING THE FFC AND BMX
SOUNDINGS ARE MUCH WETTER THROUGH THE COLUMN... WITH PW VALUES 1.0-
1.5 IN... OVER 200% OF NORMAL... WHICH IS POISED TO ADVECT INTO NC.
THE DEEPEST MOISTURE WAS OBSERVED OVER CENTRAL/SRN AL INTO CENTRAL
GA... ASSOCIATED WITH A WEAK VORTICITY MAXIMUM... AND THIS IS ALSO
WHERE REGIONAL RADAR SHOWS EXPANSIVE RAIN -- SOME OF IT MODERATE --
SPREADING TOWARD SOUTH CENTRAL NC... ALTHOUGH THE NE PROGRESSION OF
THIS RAIN IS HINDERED BY INITIAL EVAPORATION ON ITS NE EDGE.
NEVERTHELESS... RADAR TRENDS SUGGEST THAT THE SOUTHERN HALF OF THE
CWA MAY SEE MEASURABLE RAIN FIRST... SIMILAR TO THE LATEST HRRR AND
WRF-ARW RUNS. WE ALSO HAVE MUCH LOWER SURFACE DEWPOINTS IN THE
NORTHERN CWA (UPPER 30S) AS COMPARED TO THE SOUTHERN AND EXTREME ERN
CWA (LOW 40S)... AND THESE LOWER DEWPOINTS WILL TAKE LONGER TO BE
OVERCOME. BASED ON THIS... HAVE MADE MINOR ADJUSTMENTS TO RAISE POPS
A BIT LATE TONIGHT OVER THE SOUTH WITH A SMALL DOWNWARD TWEAK OF
POPS IN THE NORTHWEST/NORTH CENTRAL... AND NO POPS NORTHEAST OF
RALEIGH OVERNIGHT. MUCH OF WHAT WILL INITIALLY BE SEEN ON RADAR IN
CENTRAL NC IS APT TO EVAPORATE PRIOR TO HITTING THE GROUND... BUT
STILL EXPECT A LOW CHANCE OF MEASURABLE AMOUNTS TO SPREAD INTO THE
SW CWA SOON AFTER MIDNIGHT... THEN EXPAND INTO THE REST OF THE WRN
AND SRN CWA AFTER 3 AM. AMOUNTS WILL BE VERY LIGHT... A FUNCTION OF
THE WEAK FORCING FOR ASCENT. AS ANTICIPATED EARLIER... TEMPS FELL
MOST SOON AFTER NIGHTFALL AND HAVE LEVELED OFF SOMEWHAT... AND THE
ENCROACHMENT OF CLOUDS WILL FURTHER BLANKET THE CWA OVERNIGHT...
LIMITING TEMP FALL. EXPECT LOWS TO RANGE FROM THE LOWER 40S (NE) TO
UPPER 40S (WEST). -GIH
EARLIER DISCUSSION FROM 255 PM: LATEST SURFACE ANALYSIS SHOWS AN
AREA OF SURFACE HIGH PRESSURE CENTERED NEAR THE NC/SC COAST ALONG
THE COASTAL CAROLINAS AND VIRGINIA. A POSITIVELY TILTED DEAMPLIFYING
UPPER TROUGH ACROSS THE WESTERN PLAINS AT MIDDAY TODAY WILL CONTINUE
TO SHIFT SLOWLY EAST TODAY AND TONIGHT. THE NORTHERN PORTION OF THE
TROUGH ASSOCIATED WITH THE NORTHERN JET STREAM WILL SHEAR EAST INTO
THE EASTERN GREAT LAKES WHILE BY LATE SUNDAY AFTERNOON. THE SOUTHERN
EXTENT OF THE TROUGH IS SHARPER AND MOVES SLOWLY EAST REACHING THE
ARKLATEX BY SUNDAY EVENING. THE ASSOCIATED COLD FRONT WHICH EXTENDS
FROM MICHIGAN SOUTHWEST TO EASTERN TX AT MIDDAY TODAY WILL MOVE EAST
REACHING EASTERN PA AND NORTHWEST GA BY LATE SUNDAY AFTERNOON.
MAINLY CLEAR SKIES ACROSS CENTRAL NC THIS AFTERNOON WILL GIVE WAY TO
INCREASING HIGH AND MID CLOUDINESS THIS EVENING AS MOISTURE BEGINS
TO INCREASE AHEAD OF THE FRONT. WHILE HIGH AND MID LEVEL CLOUDINESS
WILL THICKEN OVERNIGHT... NAM/GFS/SREF BUFR SOUNDINGS ALL NOTE THAT
THE LOWER THIRD OF THE TROPOSPHERE IS SLOW TO MOISTEN OVERNIGHT
UNTIL LOW LEVEL MOISTURE SURGES INTO THE REGION FROM THE SOUTHWEST
TOWARD DAYBREAK SUNDAY. THE PRECIPITATION IS LARGELY DRIVEN BY
ISENTROPIC LIFT AROUND THE 295K SURFACE WITH THE BEST SURGE OF LIFT
SKIRTING ACROSS THE NORTHWESTERN EDGE OF CENTRAL NC AND WILL
ADVERTISE LOW CATEGORICAL POPS THERE. FORCING FOR ASCENT DECREASES
TO THE SOUTH AND EAST ON SUNDAY WITH LOW CHANCE POPS ADVERTISED FOR
THE SANDHILLS AND SOUTHERN COASTAL PLAIN. SO SUNDAY WILL FEATURE
CLOUDY SKIES ACROSS CENTRAL NC IT WONT BE WASHOUT FOR EVERYONE.
MAINLY SPOTTY LIGHT RAIN IS EXPECTED TO THE SOUTH AND SOUTHEAST OF
RALEIGH WITH THE MOST WIDESPREAD RAIN EXPECTED NEAR AND ESPECIALLY
TO THE NORTHWEST OF INTERSTATE 85.
TEMPERATURES WILL BE A LITTLE TRICKY AS THEY WILL TEND TO FALL
QUICKLY THIS EVENING AFTER SUNSET BUT THE OVERNIGHT TREND WILL BE
COMPLICATED BY THE INCREASING MID AND HIGH CLOUDS AND THE LIGHT
SOUTHERLY STIRRING AHEAD OF THE APPROACHING COLD FRONT. WILL
FORECAST LOWS IN THE MID 40S WEST TO LOWER 40S EAST. HIGHS ON SUNDAY
WILL BE COMPLICATED BY TE PRECIPITATION WHICH SHOULD KEEP HIGHS IN
THE MID 50S ACROSS THE NORTHWEST PIEDMONT WITH MID 60S ACROSS THE
SANDHILLS AND SOUTHERN COASTAL PLAIN WHERE THE RAIN WILL BE MORE
SCATTERED. -BLAES
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
AS OF 330 PM SATURDAY...
SUNDAY NIGHT...DEEP SW FLOW WILL MAINTAIN A MOIST AIR MASS ACROSS
CENTRAL NC SUNDAY NIGHT INTO MONDAY MORNING. A STOUT DISTURBANCE
ALOFT WILL APPROACH IN THE SW FLOW LATE SUNDAY AND CROSS OUR REGION
EARLY MONDAY. MEANWHILE CENTRAL NC WILL BE IN THE RIGHT ENTRANCE
REGION OF A 130-150KT JET. THE ENHANCED LIFT SUPPLIED BY BOTH THE
JET AND THE APPROACHING DISTURBANCE INTERACTING WITH AN ABNORMALLY
MOIST AIR MASS (PRECIP WATER VALUES PROJECTED TO BE 1-1.2 INCHES)
WILL CAUSE RAIN TO BECOME WIDESPREAD LATE SUNDAY NIGHT INTO EARLY
MONDAY. MIN TEMPS UPPER 40S FAR NORTH TO THE LOW-MID 50S FAR SOUTH.
MONDAY... WIDESPREAD RAIN WILL DIMINISH IN COVERAGE AND INTENSITY BY
MID DAY-EARLY AFTERNOON AS THE UPPER LEVEL DISTURBANCE AND THE JET
DEPART OUR REGION. WHILE THE MID-UPPER LEVELS OF THE ATMOSPHERE WILL
DRY OUT...SW FLOW IN THE 925-850MB LAYER WILL MAINTAIN SATURATION
RESULTING IN OVERCAST SKIES WITH SPOTS OF RAIN AND/OR DRIZZLE.
SURFACE COLD FRONT WILL DRAG SOUTHWARD ACROSS THE REGION AS THE
UPPER DISTURBANCE PULLS OUT TO THE EAST-NE. A SHALLOW COLD AIR AIR
MASS WILL INFILTRATE OUR REGION FROM THE NORTH. THIS SHOULD LEAD TO
FALLING TEMPS BY LATE MORNING ACROSS THE NORTH...AND THE AFTERNOON
ACROSS THE SOUTH.
MONDAY NIGHT INTO TUESDAY...850MB TROUGH PROJECTED TO REMAIN WEST OF
OUR REGION UNTIL MID DAY TUESDAY. THIS SUGGEST A CONTINUATION IN
EXTENSIVE CLOUDINESS AND PATCHY LIGHT RAIN/DRIZZLE THROUGH THE
MAJORITY OF MONDAY NIGHT. PASSAGE OF 850MB TROUGH AND ENSUING W-NW
FLOW IN ITS WAKE ALONG WITH SUBSIDENCE WILL AID TO DISSIPATE CLOUD
COVERAGE WEST-TO-EAST TUESDAY AFTERNOON. LOW LEVEL COLD AIR
ADVECTION WILL RESULT IN A SMALLER THAN NORMAL DIURNAL TEMP
RECOVERY. MIN TEMPS MID-UPPER 40S NORTH TO LOWER 40S SOUTH. MAX
TEMPS TUESDAY MID 40S NORTH TO NEAR 50 SOUTH.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 340 AM SUNDAY...
TUE: A WELL-DEFINED SHORTWAVE TROUGH OVER WA THIS MORNING WILL
AMPLIFY ACROSS THE ROCKIES THROUGH TONIGHT...THEN DEAMPLIFY FROM THE
CENTRAL PLAINS TO THE MIDDLE ATLANTIC COAST TUE THROUGH TUE NIGHT.
THE PASSAGE OF THIS FEATURE AND ASSOCIATED GLANCING BLOW OF THE
SOUTHERN PERIPHERY OF HEIGHT FALLS ALOFT...AND ASSOCIATED FORCING
FOR ASCENT...WILL PRODUCED RENEWED LIFT ATOP A STILL-SATURATED LAYER
IN ROUGHLY THE LOWEST SEVERAL THOUSAND FT --DEEPEST NEAR THE VA
BORDER/IN CLOSEST PROXIMITY TO THE STRONGEST HEIGHT FALLS ALOFT OVER
THE MIDDLE ATLANTIC-- SUCH THAT OTHERWISE PERIODS OF DRIZZLE THROUGH
EARLY TUE WILL BECOME LIGHT RAIN DURING THE MORNING TO MIDDAY HOURS.
BEHIND THE PASSING SHORTWAVE TROUGH...NW 925-850 MB FLOW WILL
PROMOTE BOTH DOWNSLOPE FLOW AND A DISSIPATION OF THE CAD INVERSION
VIA CAA - BOTH MECHANISMS THAT SHOULD SERVE TO SCOUR THE CAD REGIME
AND PROMOTE CLEARING BY THE AFTERNOON OR EVENING. THE TIMING OF THIS
PROCESS REMAINS IN QUESTION OWING TO TIMING DIFFERENCES AMONGST NWP
GUIDANCE REGARDING THE PASSAGE OF THE SHORTWAVE TROUGH...THOUGH
THERE HAS BEEN AN OVERALL SLOWER TREND EVIDENT IN THE GUIDANCE. AS
SUCH...WILL FAVOR A SLOWER CLEARING TREND FROM WEST TO EAST SUCH
THAT TEMPERATURES LIKELY WILL NOT HAVE TIME TO RESPOND TO THE
SETTING AFTERNOON SUN...WHICH WOULD RESULT IN HIGHS ONLY IN THE
LOWER TO MIDDLE 40S. IF A FEW HOUR PERIOD OF SUN DOES MATERIALIZE...
MOST LIKELY OVER THE SOUTHERN AND WESTERN PIEDMONT DURING THE
AFTERNOON...TEMPERATURES WOULD RESPOND TO NEAR NORMAL VALUES IN THE
UPPER 40S.
TUE NIGHT-SAT: STRONG...ARCTIC HIGH PRESSURE OVER THE ROCKIES EARLY
IN THE PERIOD WILL OTHERWISE SPRAWL EAST ACROSS THE MIDDLE ATLANTIC
AND SOUTHEAST STATES...THROUGH THU...BENEATH GENERALLY WESTERLY FLOW
BETWEEN CONFLUENT BRANCHES OF THE UPPER JET...BEFORE DRIFTING
OFFSHORE AHEAD OF AN EJECTING DESERT SW (BRIEFLY) CUTOFF LOW FRI-
SAT. THE RESULT WILL BE COOL CONDITIONS --MOST NOTABLY WED AND THU
MORNINGS WHEN TEMPERATURES SHOULD DIP WELL INTO THE 20S (WITH UPPER
TEENS POSSIBLE IN OUTLYING AREAS THAT EXPERIENCE CALM) GIVEN
PROJECTED LOW LEVEL THICKNESS VALUES IN THE 1290-1300 METER RANGE.
IT WILL ALSO BE CLEAR OR MOSTLY SO DURING MOST OF THE PERIOD...WITH
THE EXCEPTION OF A PERIOD OF PASSING MID-HIGH CLOUDS IN ASSOCIATION
WITH A STRONGLY-SHEARED AND POSITIVELY-TILTED TRAILING SHORTWAVE
TROUGH DURING THE DAY WED.
WHILE MEDIUM RANGE GUIDANCE DIVERGES WITH RESPECT TO THE EJECTION OF
THE AFOREMENTIONED DESERT SW LOW AND ASSOCIATED APPROACH OF THE NEXT
FRONTAL SYSTEM...THE OVERALL PATTERN (WITH TIMING DIFFERENCES TO BE
WORKED OUT) WOULD RESULT IN A LOW TRACK TO THE NW OF CENTRAL NC AND
AN ASSOCIATED WARM FRONTAL PASSAGE IN RETURN FLOW AROUND THE
DEPARTING AND MODIFIED ARCTIC HIGH --TIMING MOST LIKELY FRI NIGHT-
SAT FAVORED (DUE TO TYPICAL FAST BIAS IN NWP WITH SW CUTOFFS) AS
DEPICTED BY THE SLOWER EC AND EC MEAN. IF SHOWERS OCCUR WITH THE
PASSAGE OF THE WARM FRONT...MOST LIKELY OVER THE WESTERN PIEDMONT...
AN IN-SITU DAMMING EVENT WOULD EVOLVE INTO THE EARLY PART OF THE
WEEKEND...IN A PATTERN OTHERWISE SUPPORTIVE OF WARMING TEMPERATURES
OVER THE SE CONUS. AS SUCH...TEMPERATURES ON SAT ARE APT TO DISPLAY
A WIDER THAN AVG RANGE OVER CENTRAL NC...WITH MARKEDLY COOLER
TEMPERATURES OVER THE NW PIEDMONT.
&&
.AVIATION /06Z SUNDAY THROUGH WEDNESDAY/...
AS OF 115 AM SUNDAY...
AN AREA OF LIGHT RAIN ASSOCIATED WITH WEAK UPPER LEVEL DISTURBANCE
WILL BRING SOME SUB-VFR CONDITIONS TO CENTRAL NC TODAY.
HOWEVER...GIVEN THE AMOUNT OF DRY AIR STILL IN PLACE OVER THE
AREA...THERE REMAIN UNCERTAINTY REGARDING HOW MUCH RAIN WILL FALL AND
HOW LOW CEILINGS WILL DROP. WHILE A FEW SPRINKLES ARE POSSIBLE
THROUGH 12Z...CEILINGS WILL MOSTLY REMAIN AT OR ABOVE 10K FT.
BETTER MOISTURE IS STILL EXPECTED TO SPREAD UP ACROSS THE WESTERN
PIEDMONT...WHERE THERE IS A BETTER CHANCE OF MORE STEADY RAIN AND
CEILINGS IN THE MVFR OR IFR RANGE IN THE 12Z TO 21Z TIME FRAME. TO
THE EAST...WHERE SUPPORT FOR PRECIP IS WEAKER...CONFIDENCE IN MVFR
CEILINGS IS LOWER...AND SOME GUIDANCE SUGGESTS CEILINGS MAY REMAIN
VFR THROUGH MIDDAY FROM KRDU EASTWARD.
EXPECT THE LIGHT RAIN TO THEN BE INTERMITTENT LATER THIS AFTERNOON
AS A LULL DEVELOPS...WITH A PERIOD OF VFR CONDITIONS POSSIBLE BEFORE
A COLD FRONT PUSHES INTO THE AREA FROM THE NORTH TONIGHT. WINDS
WILL BE 5-10KT OUT OF THE SOUTHWEST TODAY...TURNING TO NORTHWESTERLY
AND THEN NORTHERLY BEHIND THE FRONT TONIGHT.
LOOKING AHEAD: CEILINGS WILL REDEVELOP MONDAY AS STRENGTHENING
SOUTHERLY FLOW ATOP THE SOUTHWARD SINKING COLD FRONT LEADS TO
WIDESPREAD RAIN. THESE LOW CEILINGS...ALONG WITH SOME PERIODS OF
LIGHT RAIN OR DRIZZLE WILL LINGER THROUGH MONDAY NIGHT...WITH
CONDITIONS EXPECTED TO IMPROVE TUESDAY
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD/BLAES
SHORT TERM....WSS
LONG TERM...MWS
AVIATION...BLS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
115 AM EST SUN DEC 28 2014
.SYNOPSIS... A COLD FRONT WILL APPROACH FROM THE NORTHWEST TODAY...
THEN PUSH SLOWLY SOUTHEAST THROUGH THE AREA MONDAY AND MONDAY NIGHT.
HIGH PRESSURE WILL BUILD IN FROM THE WEST LATE TUESDAY THROUGH
THURSDAY.
&&
.NEAR TERM /TONIGHT THROUGH SUNDAY/...
AS OF 920 PM SATURDAY...
SATELLITE CLOUD TRENDS SUPPORT EARLIER EXPECTATIONS OF CLOUDS
OVERSPREADING CENTRAL NC FROM THE WEST AND SW... WITH CLOUDS
STEADILY THICKENING AND LOWERING OVERNIGHT. THIS IS EXHIBITED WELL
BY A COMPARISON OF THE 00Z GSO SOUNDING WITH UPSTREAM SOUNDINGS...
WITH DRY AIR NEAR 500 MB AND BELOW 700 MB AND A PW NEAR 0.6 IN AT
GSO... WHEREAS UPSTREAM LOCATIONS INCLUDING THE FFC AND BMX
SOUNDINGS ARE MUCH WETTER THROUGH THE COLUMN... WITH PW VALUES 1.0-
1.5 IN... OVER 200% OF NORMAL... WHICH IS POISED TO ADVECT INTO NC.
THE DEEPEST MOISTURE WAS OBSERVED OVER CENTRAL/SRN AL INTO CENTRAL
GA... ASSOCIATED WITH A WEAK VORTICITY MAXIMUM... AND THIS IS ALSO
WHERE REGIONAL RADAR SHOWS EXPANSIVE RAIN -- SOME OF IT MODERATE --
SPREADING TOWARD SOUTH CENTRAL NC... ALTHOUGH THE NE PROGRESSION OF
THIS RAIN IS HINDERED BY INITIAL EVAPORATION ON ITS NE EDGE.
NEVERTHELESS... RADAR TRENDS SUGGEST THAT THE SOUTHERN HALF OF THE
CWA MAY SEE MEASURABLE RAIN FIRST... SIMILAR TO THE LATEST HRRR AND
WRF-ARW RUNS. WE ALSO HAVE MUCH LOWER SURFACE DEWPOINTS IN THE
NORTHERN CWA (UPPER 30S) AS COMPARED TO THE SOUTHERN AND EXTREME ERN
CWA (LOW 40S)... AND THESE LOWER DEWPOINTS WILL TAKE LONGER TO BE
OVERCOME. BASED ON THIS... HAVE MADE MINOR ADJUSTMENTS TO RAISE POPS
A BIT LATE TONIGHT OVER THE SOUTH WITH A SMALL DOWNWARD TWEAK OF
POPS IN THE NORTHWEST/NORTH CENTRAL... AND NO POPS NORTHEAST OF
RALEIGH OVERNIGHT. MUCH OF WHAT WILL INITIALLY BE SEEN ON RADAR IN
CENTRAL NC IS APT TO EVAPORATE PRIOR TO HITTING THE GROUND... BUT
STILL EXPECT A LOW CHANCE OF MEASURABLE AMOUNTS TO SPREAD INTO THE
SW CWA SOON AFTER MIDNIGHT... THEN EXPAND INTO THE REST OF THE WRN
AND SRN CWA AFTER 3 AM. AMOUNTS WILL BE VERY LIGHT... A FUNCTION OF
THE WEAK FORCING FOR ASCENT. AS ANTICIPATED EARLIER... TEMPS FELL
MOST SOON AFTER NIGHTFALL AND HAVE LEVELED OFF SOMEWHAT... AND THE
ENCROACHMENT OF CLOUDS WILL FURTHER BLANKET THE CWA OVERNIGHT...
LIMITING TEMP FALL. EXPECT LOWS TO RANGE FROM THE LOWER 40S (NE) TO
UPPER 40S (WEST). -GIH
EARLIER DISCUSSION FROM 255 PM: LATEST SURFACE ANALYSIS SHOWS AN
AREA OF SURFACE HIGH PRESSURE CENTERED NEAR THE NC/SC COAST ALONG
THE COASTAL CAROLINAS AND VIRGINIA. A POSITIVELY TILTED DEAMPLIFYING
UPPER TROUGH ACROSS THE WESTERN PLAINS AT MIDDAY TODAY WILL CONTINUE
TO SHIFT SLOWLY EAST TODAY AND TONIGHT. THE NORTHERN PORTION OF THE
TROUGH ASSOCIATED WITH THE NORTHERN JET STREAM WILL SHEAR EAST INTO
THE EASTERN GREAT LAKES WHILE BY LATE SUNDAY AFTERNOON. THE SOUTHERN
EXTENT OF THE TROUGH IS SHARPER AND MOVES SLOWLY EAST REACHING THE
ARKLATEX BY SUNDAY EVENING. THE ASSOCIATED COLD FRONT WHICH EXTENDS
FROM MICHIGAN SOUTHWEST TO EASTERN TX AT MIDDAY TODAY WILL MOVE EAST
REACHING EASTERN PA AND NORTHWEST GA BY LATE SUNDAY AFTERNOON.
MAINLY CLEAR SKIES ACROSS CENTRAL NC THIS AFTERNOON WILL GIVE WAY TO
INCREASING HIGH AND MID CLOUDINESS THIS EVENING AS MOISTURE BEGINS
TO INCREASE AHEAD OF THE FRONT. WHILE HIGH AND MID LEVEL CLOUDINESS
WILL THICKEN OVERNIGHT... NAM/GFS/SREF BUFR SOUNDINGS ALL NOTE THAT
THE LOWER THIRD OF THE TROPOSPHERE IS SLOW TO MOISTEN OVERNIGHT
UNTIL LOW LEVEL MOISTURE SURGES INTO THE REGION FROM THE SOUTHWEST
TOWARD DAYBREAK SUNDAY. THE PRECIPITATION IS LARGELY DRIVEN BY
ISENTROPIC LIFT AROUND THE 295K SURFACE WITH THE BEST SURGE OF LIFT
SKIRTING ACROSS THE NORTHWESTERN EDGE OF CENTRAL NC AND WILL
ADVERTISE LOW CATEGORICAL POPS THERE. FORCING FOR ASCENT DECREASES
TO THE SOUTH AND EAST ON SUNDAY WITH LOW CHANCE POPS ADVERTISED FOR
THE SANDHILLS AND SOUTHERN COASTAL PLAIN. SO SUNDAY WILL FEATURE
CLOUDY SKIES ACROSS CENTRAL NC IT WONT BE WASHOUT FOR EVERYONE.
MAINLY SPOTTY LIGHT RAIN IS EXPECTED TO THE SOUTH AND SOUTHEAST OF
RALEIGH WITH THE MOST WIDESPREAD RAIN EXPECTED NEAR AND ESPECIALLY
TO THE NORTHWEST OF INTERSTATE 85.
TEMPERATURES WILL BE A LITTLE TRICKY AS THEY WILL TEND TO FALL
QUICKLY THIS EVENING AFTER SUNSET BUT THE OVERNIGHT TREND WILL BE
COMPLICATED BY THE INCREASING MID AND HIGH CLOUDS AND THE LIGHT
SOUTHERLY STIRRING AHEAD OF THE APPROACHING COLD FRONT. WILL
FORECAST LOWS IN THE MID 40S WEST TO LOWER 40S EAST. HIGHS ON SUNDAY
WILL BE COMPLICATED BY TE PRECIPITATION WHICH SHOULD KEEP HIGHS IN
THE MID 50S ACROSS THE NORTHWEST PIEDMONT WITH MID 60S ACROSS THE
SANDHILLS AND SOUTHERN COASTAL PLAIN WHERE THE RAIN WILL BE MORE
SCATTERED. -BLAES
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
AS OF 330 PM SATURDAY...
SUNDAY NIGHT...DEEP SW FLOW WILL MAINTAIN A MOIST AIR MASS ACROSS
CENTRAL NC SUNDAY NIGHT INTO MONDAY MORNING. A STOUT DISTURBANCE
ALOFT WILL APPROACH IN THE SW FLOW LATE SUNDAY AND CROSS OUR REGION
EARLY MONDAY. MEANWHILE CENTRAL NC WILL BE IN THE RIGHT ENTRANCE
REGION OF A 130-150KT JET. THE ENHANCED LIFT SUPPLIED BY BOTH THE
JET AND THE APPROACHING DISTURBANCE INTERACTING WITH AN ABNORMALLY
MOIST AIR MASS (PRECIP WATER VALUES PROJECTED TO BE 1-1.2 INCHES)
WILL CAUSE RAIN TO BECOME WIDESPREAD LATE SUNDAY NIGHT INTO EARLY
MONDAY. MIN TEMPS UPPER 40S FAR NORTH TO THE LOW-MID 50S FAR SOUTH.
MONDAY... WIDESPREAD RAIN WILL DIMINISH IN COVERAGE AND INTENSITY BY
MID DAY-EARLY AFTERNOON AS THE UPPER LEVEL DISTURBANCE AND THE JET
DEPART OUR REGION. WHILE THE MID-UPPER LEVELS OF THE ATMOSPHERE WILL
DRY OUT...SW FLOW IN THE 925-850MB LAYER WILL MAINTAIN SATURATION
RESULTING IN OVERCAST SKIES WITH SPOTS OF RAIN AND/OR DRIZZLE.
SURFACE COLD FRONT WILL DRAG SOUTHWARD ACROSS THE REGION AS THE
UPPER DISTURBANCE PULLS OUT TO THE EAST-NE. A SHALLOW COLD AIR AIR
MASS WILL INFILTRATE OUR REGION FROM THE NORTH. THIS SHOULD LEAD TO
FALLING TEMPS BY LATE MORNING ACROSS THE NORTH...AND THE AFTERNOON
ACROSS THE SOUTH.
MONDAY NIGHT INTO TUESDAY...850MB TROUGH PROJECTED TO REMAIN WEST OF
OUR REGION UNTIL MID DAY TUESDAY. THIS SUGGEST A CONTINUATION IN
EXTENSIVE CLOUDINESS AND PATCHY LIGHT RAIN/DRIZZLE THROUGH THE
MAJORITY OF MONDAY NIGHT. PASSAGE OF 850MB TROUGH AND ENSUING W-NW
FLOW IN ITS WAKE ALONG WITH SUBSIDENCE WILL AID TO DISSIPATE CLOUD
COVERAGE WEST-TO-EAST TUESDAY AFTERNOON. LOW LEVEL COLD AIR
ADVECTION WILL RESULT IN A SMALLER THAN NORMAL DIURNAL TEMP
RECOVERY. MIN TEMPS MID-UPPER 40S NORTH TO LOWER 40S SOUTH. MAX
TEMPS TUESDAY MID 40S NORTH TO NEAR 50 SOUTH.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 330 PM SATURDAY...
WEDNESDAY THROUGH SATURDAY... A BROAD UPPER LEVEL TROUGH WILL COVER
THE BULK OF THE U.S. THIS PERIOD WITH A CLOSED UPPER LEVEL LOW
PROJECTED TO EDGE SLOWLY EAST ACROSS THE SW U.S-SOUTHERN ROCKIES.
MODEL GUIDANCE TRADITIONALLY HAVE TROUBLE TIMING THE MOVEMENT OF
THESE CLOSED LOWS INT EH SW. USUALLY...SLOWER IS BETTER.
FOR CENTRAL NC...EXPECT DRY CONDITIONS THROUGH AT LEAST FRIDAY AND
POSSIBLY INTO SATURDAY WITH TEMPS BELOW NORMAL AT MID
WEEK...MODERATING TO NEAR NORMAL LEVELS BY THE WEEKEND. A S/W WILL
CROSS THE MID ATLANTIC LATE WEDNESDAY-WEDNESDAY NIGHT...ACCOMPANIED
BY A DRY SFC FRONT PASSAGE. FLOW BEHIND THIS FEATURE WILL REINFORCE
THE COOL AIR IN PLACE. MAX TEMPS WILL AVERAGE 4-6 DEGREES BELOW
NORMAL WEDNESDAY-FRIDAY WHILE OVERNIGHT LOWS IN THE 20S WILL BE
COMMON.
TIMING DIFFERENCES IN THE MODELS BY NEXT WEEKEND PLAY HAVOC WITH
PRECIP CHANCES AND TEMP FORECAST. PERSISTENT WLY FLOW SHOULD LEAD TO
MODIFICATION OF THE AIR MASS...LEADING TO TEMPS AT OR ABOVE NORMAL.
IF PRECIP DELAYED UNTIL LATE SATURDAY OR SATURDAY NIGHT...POTENTIAL
FOR TEMPS TO BE WELL ABOVE NORMAL.
&&
.AVIATION /06Z SUNDAY THROUGH WEDNESDAY/...
AS OF 115 AM SUNDAY...
AN AREA OF LIGHT RAIN ASSOCIATED WITH WEAK UPPER LEVEL DISTURBANCE
WILL BRING SOME SUB-VFR CONDITIONS TO CENTRAL NC TODAY.
HOWEVER...GIVEN THE AMOUNT OF DRY AIR STILL IN PLACE OVER THE
AREA...THERE REMAIN UNCERTAINTY REGARDING HOW MUCH RAIN WILL FALL AND
HOW LOW CEILINGS WILL DROP. WHILE A FEW SPRINKLES ARE POSSIBLE
THROUGH 12Z...CEILINGS WILL MOSTLY REMAIN AT OR ABOVE 10K FT.
BETTER MOISTURE IS STILL EXPECTED TO SPREAD UP ACROSS THE WESTERN
PIEDMONT...WHERE THERE IS A BETTER CHANCE OF MORE STEADY RAIN AND
CEILINGS IN THE MVFR OR IFR RANGE IN THE 12Z TO 21Z TIME FRAME. TO
THE EAST...WHERE SUPPORT FOR PRECIP IS WEAKER...CONFIDENCE IN MVFR
CEILINGS IS LOWER...AND SOME GUIDANCE SUGGESTS CEILINGS MAY REMAIN
VFR THROUGH MIDDAY FROM KRDU EASTWARD.
EXPECT THE LIGHT RAIN TO THEN BE INTERMITTENT LATER THIS AFTERNOON
AS A LULL DEVELOPS...WITH A PERIOD OF VFR CONDITIONS POSSIBLE BEFORE
A COLD FRONT PUSHES INTO THE AREA FROM THE NORTH TONIGHT. WINDS
WILL BE 5-10KT OUT OF THE SOUTHWEST TODAY...TURNING TO NORTHWESTERLY
AND THEN NORTHERLY BEHIND THE FRONT TONIGHT.
LOOKING AHEAD: CEILINGS WILL REDEVELOP MONDAY AS STRENGTHENING
SOUTHERLY FLOW ATOP THE SOUTHWARD SINKING COLD FRONT LEADS TO
WIDESPREAD RAIN. THESE LOW CEILINGS...ALONG WITH SOME PERIODS OF
LIGHT RAIN OR DRIZZLE WILL LINGER THROUGH MONDAY NIGHT...WITH
CONDITIONS EXPECTED TO IMPROVE TUESDAY
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD/BLAES
SHORT TERM....WSS
LONG TERM...WSS
AVIATION...BLS
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
330 PM EST SUN DEC 28 2014
.SYNOPSIS...
HIGH PRESSURE WILL BUILD OVER THE REGION FROM THE WEST TONIGHT AND
INTO TUESDAY. A COLD FRONT WILL SAG SOUTH ACROSS THE REGION LATER
TUESDAY. HIGH PRESSURE WILL SLOWLY BUILD OVER THE REGION FROM THE
SOUTHWEST THE SECOND HALF OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS FEARED CLOUDS HAVE BEEN SLOW TO EXIT THE AREA. STILL SEEING LOW
CIGS IN NW OHIO THIS AFTERNOON WITH A SWATCH OF HIGH CLOUDS ABOVE
AS WELL. DRIER AIR AND HIGH PRESSURE WILL GRADUALLY WIN OUT
OVERNIGHT AND WILL STILL TRY TO TAKE THE SW HALF OF THE AREA TO
PARTLY CLOUDY OVERNIGHT. FORECAST SOUNDINGS AND THE LATEST HRRR
CONTINUE TO HINT AT SOME LIGHT SNOW OVER NW PA TONIGHT AS LOW
LEVEL MOISTURE PERSISTS A WHILE LONGER. 850 MB TEMPS WILL DIP TO
NEG 9 OR SO BY MORNING SO WILL INTRODUCE A SMALL 20 POP FOR SNOW
SHOWERS. NOT EXPECTING ANY ACCUMULATION AND REALISTICALLY PROBABLY
NOT MUCH MORE THAN FLURRIES. THE EVENING CREW WILL HAVE TO WATCH
TEMPS...IF THE CLOUDS LINGER...FORECAST LOWS WILL NEED TO BE
NUDGED UP.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
ALL IN ALL IT SHOULD BE A QUIET PERIOD AS A STRONG AREA OF HIGH PRESSURE
EXERTS ITSELF OVER THE REGION. MAY BE SOME LINGERING FLURRIES AT
DAYBREAK OVER NW PA BUT THOSE SHOULD END QUICKLY AS DRIER AIR
SETTLES IN FROM THE NORTH. WILL SEE ANOTHER COLD FRONT SAG SOUTH
ACROSS THE AREA SOMETIME LATE TUESDAY. AT THAT POINT TEMPS WILL
REALLY TAKE A DOWNWARD TURN. MOISTURE BEHIND THE FRONT IS LACKING
BUT GIVEN LAKE TO 850 MB TEMPERATURE DIFFERENCES APPROACHING 20
DEGREES...THERE SHOULD BE AT LEAST A FEW SNOW SHOWERS FROM KCLE
EAST TUESDAY NIGHT AND WEDNESDAY. FORECAST SOUNDINGS INITIALLY
SHOW A CAPPING INVERSION OF 6 TO 7K FEET BUT THIS WILL LOWER ON
WEDNESDAY. MOISTURE APPEARS TO BE LACKING AS WELL SO NOT EXPECTING
ANY HEADLINES AND PROBABLY NO MORE THAN A COUPLE INCHES OF SNOW
EVEN IN PREFERRED AREA. SNOW CHANCES WILL BEGIN TO DIMINISH BY
WEDNESDAY EVENING AS THE FLOW BEGINS TO PUSH ANY SNOW BANDS NORTH
ONTO LAKE ERIE.
HAVE CONTINUED THE RECENT TREND OF NUDGING TEMPS DOWN SLIGHTLY FOR
THE MIDDLE PART OF THE WEEK. TEMPS MONDAY WILL BE SEASONABLE BUT
BY WEDNESDAY READINGS WILL STRUGGLE TO GET MUCH ABOVE 20 DEGREES
FOR HIGHS. THE NEW GUIDANCE SEEMS TO HAVE A FAIRLY GOOD HANDLE ON
THIS AND HAVE USED A BLEND OF GUIDANCE.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
FORECAST DURING THIS PERIOD IS RATHER COMPLICATED WITH LOWER
CONFIDENCE. THE MODELS HAVE SOME DIFFERENCES IN THE PHASING OF THE
SPLIT FLOW OVER THE NATION AND THE TREATMENT OF THE SHORT WAVE IN
THE SOUTHERN STREAM. THE GFS DEVELOPS A LOW PRESSURE OVER THE
MISSISSIPPI VALLEY AND TRACKS IT WEST OF THE REGION TO PRODUCE RAIN
OVER THE AREA ON THE SATURDAY AS IT PHASES THE SOUTHERN STREAM SHORT
WAVE IN THE NORTHERN JET STREAM. THE ECMWF DOES NOT PHASE THE
SOUTHERN SHORT WAVE WITH THE NORTHERN STREAM AND SLOWS DOWN THE
FEATURE AND TRACKS IT SOUTH OF THE REGION. THIS KEEPS THE REGION
COLD WITH LIGHT SNOW EXPECTED. FOR THE MOST PART HAVE TAKEN A
COMPROMISED SOLUTION BETWEEN THE TWO MODELS WITH MIXED PRECIPITATION
FORECASTED.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
GRADUAL IMPROVEMENT IN CEILING HEIGHT IS EXPECTED THIS AFTERNOON AND
EVENING MAINLY AWAY FROM LAKE ERIE. WIDELY SCATTERED LIGHT RA-/SN-
FROM GEAUGA COUNTY TO YNG SHOULD END BY THE MIDDLE OF THE
AFTERNOON.
EXPECT A SCATTERING OUT OF LOW CLOUDS WEST OF CLE TOWARD SUNSET
WITH CEILINGS GENERALLY LIFTING TO THE 2500-3500FT RANGE FROM MFD TO
CLE TO ERI AND YNG INTO THE OVERNIGHT HOURS. THE HRRR MODEL
INDICATES SOME INCREASE IN LOW CLOUD COVERAGE EAST OF CLE AFTER 00 UTC
AND THIS SEEMS REASONABLE. SOME LIGHT LAKE EFFECT SNOW IS POSSIBLE
OVER EXTREME NE OHIO AND NW PA. VFR VSBYS SHOULD PREVAIL OUTSIDE
THE SNOW SHOWERS. LIGHT WINDS ARE EXPECTED.
.OUTLOOK...AREAS OF NON VFR CEILINGS LATE MONDAY NIGHT THROUGH
WEDNESDAY ESPECIALLY ACROSS NE OH/NW PA.
&&
.MARINE...
ARCTIC HIGH PRESSURE WILL GRADUALLY BUILD SOUTH AND EAST ACROSS THE
GREAT LAKES INTO WEDNESDAY. A REINFORCING COLD FRONT WILL MOVE
THROUGH THE NORTHERN LAKES WEDNESDAY NIGHT AND THURSDAY WHICH WILL
STRENGTHEN THE PRESSURE GRADIENT ACROSS THE EASTERN LAKES AND MAY
PRODUCE GALES ON LAKE ERIE LATE WEDNESDAY INTO THURSDAY. WINDS WILL
SLACKEN BRIEFLY FRIDAY AS HIGH PRESSURE BUILDS OVER THE SOUTHEAST.
MEANWHILE LOW PRESSURE WILL FORM OVER THE GULF COAST AND GRADUALLY
HEAD NORTHEAST TO THE MID ATLANTIC COAST BY MONDAY. HIGH PRESSURE
WILL BUILD EAST ACROSS ONTARIO JUST TO THE NORTH OF THE GREAT LAKES.
THERE IS SOME QUESTION ABOUT THE TRACK OF THIS LOW AND RESULTANT
WIND FORECAST FOR LAKE ERIE IS QUESTIONABLE.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KUBINA
NEAR TERM...KUBINA
SHORT TERM...KUBINA
LONG TERM...LAPLANTE
AVIATION...LAPLANTE
MARINE...LAPLANTE
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
111 PM EST SUN DEC 28 2014
.SYNOPSIS...
WEAK HIGH PRESSURE WILL BUILD IN TODAY BEHIND A COLD FRONT...NOW
EAST OF THE AREA. ANOTHER COLD FRONT WILL DROP ACROSS THE AREA ON
MONDAY AND WILL USHER IN NOTICEABLY COLDER AIR FOR MID WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE PRECIP IS PRETTY MUCH GONE AND HAVE GONE AHEAD AND PULLED THE
REMAINING PRECIP FROM THE FORECAST. HAVE SLOWED THE CLEARING DOWN
A LITTLE. STILL THINK WESTERN AREAS WILL BE PARTLY SUNNY BY MID
AFTERNOON.
ORIGINAL...COLD FRONT NOW ABOUT TO EXIT THE AREA TO THE EAST.
DRIER AIR HAS MOVED IN FROM THE WEST ENDING PRECIP JUST WEST OF A
CLE- MNN LINE. CURRENT TIMING OF THE BACK EDGE TAKES IT TO NEAR AN
KERI-KCAK LINE ABOUT 1015Z AND SOUTHEAST OF THE AREA BY 13Z OR SO.
PRECIP COULD END AS A MIX AS TEMPS DROP TOWARD MORNING BUT NOT
LOOKING FOR ANY SIGNIFICANT WINTRY PRECIP. AS FOR CLOUD
COVER...SATELLITE SHOWS STRATUS WEST OF CHICAGO ALTHOUGH RANDOM
HOLES ARE DEVELOPING FROM TIME TO TIME. BELIEVE DAY WILL BEGIN
CLOUDY ALL AREA BUT STILL THINKING THERE WILL BE BREAKS ESPECIALLY
NORTHWEST AS WE WILL BE ON THE PERIPHERY OF THE SURFACE HIGH AND
LOW LEVEL FLOW WILL TEND TO MIX. HIGHS NOT FAR FROM CURRENT TEMPS
MOST PLACES. CURRENTLY CAK AND YNG ARE JUST AHEAD OF THE FRONT
WITH TEMPS IN THE MID 40S SO HIGHS THERE ACTUALLY LOWER THAN
CURRENT AS TEMPS WILL GET KNOCKED DOWN TO NEAR 40 BEFORE DAYBREAK.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
EXPECTING DRY WX TONIGHT THROUGH MONDAY MID DAY. SLIGHT CHANCES
RETURNING FOR THE SNOWBELT AREAS MONDAY AFTERNOON INCREASING TO
CHANCE MONDAY NIGHT AS COLDER AIR DEEPENS POST SECONDARY FRONT AS
850MB TEMPS DROP TO -12-14C. STILL WITH LAKE TEMPS AT
+3C...DIFFERENTIAL ONLY MARGINALLY FAVORABLE FOR LES. WILL
CONTINUE WITH SMALL CHANCE POPS SNOWBELT EARLY TUESDAY AND SLIGHT
CHANCE POPS ELSEWHERE AS MOISTURE SPREADS EAST ACROSS THE AREA
WITH A WEAK UPPER TROF/SHORT WAVE. HIGH PRESSURE WILL BUILD IN
FROM THE WEST TUESDAY AFTERNOON HOWEVER TO DRIED IT OUT FOR THE
AFTERNOON. TUESDAY NIGHT AND WEDNESDAY...850MB TEMPS CONTINUE TO
DROP THROUGH -15 TO -18C BY WEDNESDAY MORNING WITH AT LEAST
LIMITED MOISTURE SO WILL BRING CHANCE POPS FOR LES BACK TO THE
LAKESHORE. DRY AIR ELSEWHERE HOWEVER.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
ON THURSDAY THE REGION WILL BE ON THE EDGE OF THE COLDER AIR WITH
THE NORTHERN STREAM JET POSITIONED FROM SOUTH CENTRAL
CANADA...ACROSS THE GREAT LAKES INTO NEW ENGLAND. SURFACE HIGH
PRESSURE CENTERED TO OUR SOUTH AND LOW PRESSURE OVER HUDSON BAY WILL
PROVIDE FOR A SOUTHWEST FLOW AND NOT ALLOW ANY MORE OF THE COLD AIR
TO SINK SOUTHWARD FOR THE TIME BEING. IT WILL ALSO BE DRY. THE
FORECAST FOR FRIDAY INTO THE WEEKEND GETS MUCH MORE COMPLICATED WITH
THE INTERACTION BETWEEN SHORTWAVE ENERGY EJECTING OUT OF THE FOUR
CORNERS REGION AND A DIGGING TROUGH FROM THE NORTHERN ROCKIES AND
NORTHERN PLAINS. LOOKING TOWARD THE ENSEMBLES FOR NOW PLACES LOW
PRESSURE IN THE GENERAL REGION BETWEEN SATURDAY AND SUNDAY. AS WARM
AIR ADVANCES NORTHWARD PRECIPITATION TYPE WILL BE AN ISSUE WITH A
WINTRY MIX POSSIBLE AT ONSET AND A PERIOD OF RAIN POSSIBLE TOO. THE
DEGREE/SPEED THE COLD AIR MOVES IN ON THE BACKSIDE IS IN QUESTION
TOO...AS WOULD BE EXPECTED THIS FAR OUT.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
GRADUAL IMPROVEMENT IN CEILING HEIGHT IS EXPECTED THIS AFTERNOON AND
EVENING MAINLY AWAY FROM LAKE ERIE. WIDELY SCATTERED LIGHT RA-/SN-
FROM GEAUGA COUNTY TO YNG SHOULD END BY THE MIDDLE OF THE
AFTERNOON.
EXPECT A SCATTERING OUT OF LOW CLOUDS WEST OF CLE TOWARD SUNSET
WITH CEILINGS GENERALLY LIFTING TO THE 2500-3500FT RANGE FROM MFD TO
CLE TO ERI AND YNG INTO THE OVERNIGHT HOURS. THE HRRR MODEL
INDICATES SOME INCREASE IN LOW CLOUD COVERAGE EAST OF CLE AFTER 00 UTC
AND THIS SEEMS REASONABLE. SOME LIGHT LAKE EFFECT SNOW IS POSSIBLE
OVER EXTREME NE OHIO AND NW PA. VFR VSBYS SHOULD PREVAIL OUTSIDE
THE SNOW SHOWERS. LIGHT WINDS ARE EXPECTED.
.OUTLOOK...AREAS OF NON VFR CEILINGS LATE MONDAY NIGHT THROUGH
WEDNESDAY ESPECIALLY ACROSS NE OH/NW PA.
&&
.MARINE...
WILL CONTINUE WITH THE ONGOING SMALL CRAFT ADVISORY FOR THE EAST TWO
THIRDS UNTIL MID MORNING...WITH WINDS/WAVES SUBSIDING AFTER THAT.
HIGH PRESSURE BUILDS OVER THE LAKE TODAY IN THE WAKE OF LAST NIGHTS
COLD FRONT. HIGH PRESSURE WILL CONTINUE TO BE THE MAIN INFLUENCE ON
THE LAKE WEATHER FROM MONDAY THROUGH WEDNESDAY AS IT SHIFTS FROM THE
NORTHERN ROCKIES AND PLAINS SOUTH TO THE CENTRAL PLAINS. NORTHWEST
WINDS TODAY WILL BECOME MORE NORTHERLY BY TUESDAY MORNING AND THEN
THEY WILL SETTLE BACK TOWARDS SOUTHWEST AS THAT HIGH SHIFTS SOUTH.
NEXT INCREASE IN WIND/WAVES LOOKS LIKELY FOR WEDNESDAY NIGHT INTO
THURSDAY AS THE GRADIENT TIGHTENS BETWEEN THAT HIGH AND LOW PRESSURE
OVER HUDSON BAY. THE SOUTHWEST FLOW ON THE LAKE...FOR NOW...WILL BE
FORECAST TO 30 KNOTS. THERE IS SOME POTENTIAL FOR GALE FORCE WINDS
WITH THE GRADIENT AND FETCH.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TK
NEAR TERM...TK/KUBINA
SHORT TERM...TK
LONG TERM...OUDEMAN
AVIATION...LAPLANTE
MARINE...OUDEMAN
AREA FORECAST DISCUSSION
NWS TULSA OK
904 PM CST MON DEC 29 2014
...UPDATE...
.DISCUSSION...
RADAR ECHOES ARE LEAVING THE FORECAST AREA...SO WILL DROP MENTION
OF FLURRIES FOR THE REMAINDER OF THE OVERNIGHT PERIOD. 00Z
NAM...01Z HRRR AND 02Z RAP ALL APPEAR DRY FOR THE REST OF THE
NIGHT. LFM IS MISSING...ALONG WITH BAROTROPIC AND SHIP PAPA DATA.
...HAVING A RIP VAN WINKLE MOMENT...
WILL UPDATE TO TAKE OUT FLURRIES AND SPRINKLES.
APPEARS THE COLD SURGE IS STILL IN KANSAS...FROM JUST SOUTH OF MKC
TO NORTH OF ICT TO NEAR AMA...BASED MAINLY ON LOCATION OF
STRONGEST WINDS AND GUSTINESS. PROGRESS HAS BEEN SLOW...BUT ON
TARGET FOR TUESDAY MORNING.
NO CHANGE TO MINIMUM TEMPS.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 48 28 32 14 / MMM 10 0 10
FSM 45 30 42 22 / MMM 0 0 0
MLC 50 31 38 19 / MMM 0 0 10
BVO 46 24 29 12 / MMM 10 10 10
FYV 45 28 36 14 / MMM 0 0 0
BYV 43 27 36 14 / MMM 0 0 0
MKO 47 28 35 16 / MMM 0 0 10
MIO 45 27 31 12 / MMM 10 10 0
F10 47 29 34 16 / MMM 0 0 10
HHW 48 29 44 24 / MMM 0 0 10
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
SHORT TERM...02
LONG TERM....02
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
948 PM EST MON DEC 29 2014
.SYNOPSIS....
A HIGHLY AMPLIFIED PATTERN OVER NORTH AMERICA WITH A STRONG RIDGE
OVER THE NORTHWEST AND A TROUGH OVER THE NORTHEAST WILL PRODUCE
TWO COLD SURGES. THE FIRST SHOULD PRODUCE COLD WEATHER TROUGH NEW
YEARS. A SOUTHERN STREAM STORM COULD BRING A WINTRY MIX AND/OR
RAIN TO THE REGION AHEAD OF THE FORECAST SECOND SURGE OF COLD
CONTINENTAL AIR. LONGER RANGE FORECASTS SHOW A LESS AMPLIFIED
PATTERN DEVELOPING LATE NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
SATELLITE CONTINUES TO SHOW TWO DISTINCT CLOUDS SYSTEMS...HIGH
CLOUDS PASSING TO OUR SOUTH AND LOW CLOUDS NEAR THE NY BORDER.
HRRR SUGGESTS OUR FORECASTS IN SOUTH/CENTRAL ARE TOO CLOUDY.
HRRR ALSO SHOWS NO SIGNIFICANT SNOW AREAS OVERNIGHT IN NORTHWEST.
THE WEAK NORTHWEST FLOW OUT OF THE HIGH DOES NOT CAUSE THE MODEL
TO GENERATE ANY LAKE ENHANCED SNOWS.
CHILLY NIGHT AND ADJUSTED TEMPERATURES WITH NEWER GUIDANCE.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY/...
THE HRRR ONLY GETS US TO LATE MORNING AND IT SHOWS...AT BEST SOME
FLURRIES IN SPOTS ALONG NY BORDER IN MORNING.
HIGH PRESSURE TO OUR WEST CONTINUES TO BUILD INTO THE REGION FROM
THE WEST TUESDAY. IN THIS NORTH-NORTHWEST FLOW OUR 850 MB TEMPS
FALL 2 TO 4 MORE DEGREES DURING THE DAY GETTING TO ABOUT -1SD
BELOW NORMAL BY EVENING. A COLDER THAN NORMAL DAY IS ON TAP.
THE HIGH SLIDES TO OUR SOUTH AND WEST INTO WEDNESDAY AND OUR 850
MB TEMPS BOTTOM OUT IN THE -13 TO -18C RANGE. THIS IMPLIES BETTER
CHANCE OF SOME LAKE ENHANCED SNOWS IN NORTHWESTERN AND WESTERN
MOUNTAINS. THE SNOW IN NW PA AND SW NY PEAKS IN THE SREF AFTER 00
TO 03 UTC WEDNESDAY AND BEGINS TO DIMINISH WEDNESDAY EVENING.
TRIED TO SHOW SOME SNOW UP IN THE NW AREAS BUT KEPT AMOUNT ON THE
LOW SIDE. BLENDED LARGE SCALE MODELS WITH 21Z SREF TO REFINE THE
AREA OF POPS AND QPF. QPF AMOUNTS WERE OF COURSE LOW.
CLEARLY WEDNESDAY SHOULD BE ABOUT THE COLDEST DAY OF THE WINTER
TO DATE WITH THE -16C CONTOUR DRAPED OVER CENTRAL PA AND AT LEAST
-1SD BELOW NORMAL TEMPERATURES. THAT IS 5 TO 10F BELOW NORMAL.
THE COLD AT LEAST WILL CONTINUE INTO NEW YEARS DAY (SEE BELOW) AS
THE HIGH LUMBERS BY TO OUR SOUTH.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
STRONG HIGH PRESSURE OVER THE CENTRAL U.S. THIS MIDWEEK WILL
WEAKEN AND DRIFT TOWARD THE CAROLINAS BY FRIDAY AS A WEAK WAVE
SLIDES QUICKLY ACROSS THE GREAT LAKES. THIS WILL BRING AN
EXTENDED PERIOD OF FAIR BUT COOLER THAN NORMAL WEATHER TO THE
FORECAST AREA. SOME SNOW SHOWERS MAY IMPACT THE NW MTNS...BUT
MOST OF THE SNOW SHOWER ACTIVITY WILL REMAIN NORTH OF THE PA
BORDER. BREEZY CONDITIONS WED NIGHT INTO THU IN FAST FLOW WILL
RESULT IN SINGLE DIGIT WIND CHILLS OVER NORTHERN AND WESTERN PARTS
OF THE CWA AS WE RING IN THE NEW YEAR.
GEFS AND OTHER LONG RANGE GUIDANCE SHOW THE FIRST NOTABLE STORM
OF 2015 DEVELOPING FOR NEXT WEEKEND. TIMING/STORM TRACK ISSUES
REMAIN WITH MUCH UNCERTAINTY IN EVOLUTION OF THIS SYSTEM...BUT
GUIDANCE IMPLIES A POTENTIAL MIXED PRECIPITATION EVENT FROM
GENERALLY SAT AFT THROUGH FIRST HALF OF SUNDAY. GFS CONTINUES TO
BRINGS A LOW UP THE OHIO VALLEY TO OUR WEST...PUSHING A SHOT OF
MILDER AIR BACK INTO THE STATE WITH RAIN LIKELY BECOMING THE MOST
DOMINANT PRECIPITATION TYPE /WITH FREEZING PRECIP POSS AT ONSET/.
IN CONTRAST...THE OPERATIONAL ECMWF REMAINING FIRM ON BRINGING
THE SURFACE LOW SOUTH AND EAST OF PA WHICH WOULD RESULT IN COLDER
AIR AND A MORE MIXED BAG OF PRECIPITATION TYPES AND PERHAPS SNOW
IN NORTHERN AND SOME CENTRAL AREAS. THE EC MEAN IS A BIT MORE
AGGRESSIVE DEVELOPING THE LOW...POTENTIALLY MAKING THE OPERATIONAL
RUN AN OUTLIER. FOR NOW...DIDN/T MAKE ANY LARGE CHANGES TO
FORECAST OVER THE WEEKEND AND HELD ON TO THE POTENTIAL FOR A MIX
OF WINTRY PRECIP - ESP ACROSS CENTRAL AND NORTHERN PA...AND LEANED
MORE TOWARD RAIN IN THE LOWER SUSQ.
QUICK SHOT OF COLDER AIR TO START NEXT WEEK...WITH CHANCE FOR
ANOTHER LOW SLIDING EASTWARD FROM THE GREAT LAKES INTO NEW ENGLAND
MIDWEEK WITH CHANCE OF SNOW FOR PA.
&&
.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
MVFR CIGS WILL LIKELY REMAIN IN PLACE AT BFD INTO TUESDAY WITH
NORTHWESTERLY WINDS AND A CHILLY...SHALLOW AIR MASS. CONTINUED
NORTHWESTERLY FLOW WILL MAKE A FEW FLURRIES AT BFD...BUT THE REST
OF THE TERMINALS WILL REMAIN DRY AND ONLY JST MAY SEE MVFR CIGS
OVERNIGHT. CLOUDS MAY LOWER AT IPT/UNV AS THE LOW CLOUD DECK
ASSOCIATED WITH THE COLDER AIR SLIDING DOWN FROM THE NORTH MOVES
SOUTHWARD. BUT...WILL KEEP IT AS VFR THRU THE TAF PERIOD FOR THE
TIME BEING.
HIGH PRESSURE CENTERED OVER THE FRONT RANGE OF THE ROCKIES AND THE
GREAT PLAINS WILL STRETCH FAR TO THE EAST AND GRADUALLY SINK
SOUTHWARD. A BRIEF SHOT OF COLDER AIR WITHIN A FEW HOURS OF 12Z
WED MAY CREATE A BROADER AREA OF SHSN/SQ. BUT THE REDUCTIONS IN
VIS/CIG SHOULD BE LIMITED TO BFD...AND NOT EVEN JST. THE WAVE
ALOFT WILL BE ACCOMPANIED BY VERY LITTLE MOISTURE. WINDS COULD
BECOME GUSTY...THOUGH.
OUTLOOK...
WED-FRI...VFR.
SAT...MVFR/IFR POSS IN WINTRY PRECIP.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...GRUMM
NEAR TERM...GRUMM
SHORT TERM...GRUMM
LONG TERM...RXR
AVIATION...DANGELO/GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
937 PM EST MON DEC 29 2014
.SYNOPSIS...
A COLD STRETCH OF WEATHER IS IN STORE FOR CENTRAL PA WITH
TEMPERATURES BELOW SEASONAL NORMALS FOR THE REST OF THE WEEK. WEAK
DISTURBANCES WILL BRING FLURRIES OVER THE WEST AND NORTH AT TIMES.
THE NEXT CHANCE FOR MEANINGFUL PRECIPITATION WILL NOT BE UNTIL THE
WEEKEND.
&&
.NEAR TERM /UNTIL 7 AM TUESDAY MORNING/...
SATELLITE CONTINUES TO SHOW TWO DISTINCT CLOUDS SYSTEMS...HIGH
CLOUDS PASSING TO OUR SOUTH AND LOW CLOUDS NEAR THE NY BORDER.
HRRR SUGGESTS OUR FORECASTS IN SOUTH/CENTRAL ARE TOO CLOUDY.
HRRR ALSO SHOWS NO SIGNIFICANT SNOW AREAS OVERNIGHT IN NORTHWEST.
THE WEAK NORTHWEST FLOW OUT OF THE HIGH DOES NOT CAUSE THE MODEL
TO GENERATE ANY LAKE ENHANCED SNOWS.
CHILLY NIGHT AND ADJUSTED TEMPERATURES WITH NEWER GUIDANCE.
&&
.SHORT TERM /7 AM TUESDAY MORNING THROUGH WEDNESDAY/...
THE HRRR ONLY GETS US TO LATE MORNING AND IT SHOWS...AT BEST SOME
FLURRIES IN SPOTS ALONG NY BORDER IN MORNING.
HIGH PRESSURE TO OUR WEST CONTINUES TO BUILD INTO THE REGION FROM
THE WEST TUESDAY. IN THIS NORTH-NORTHWEST FLOW OUR 850 MB TEMPS
FALL 2 TO 4 MORE DEGREES DURING THE DAY GETTING TO ABOUT -1SD
BELOW NORMAL BY EVENING. A COLDER THAN NORMAL DAY IS ON TAP.
THE HIGH SLIDES TO OUR SOUTH AND WEST INTO WEDNESDAY AND OUR 850
MB TEMPS BOTTOM OUT IN THE -13 TO -18C RANGE. THIS IMPLIES BETTER
CHANCE OF SOME LAKE ENHANCED SNOWS IN NORTHWESTERN AND WESTERN
MOUNTAINS. THE SNOW IN NW PA AND SW NY PEAKS IN THE SREF AFTER 00
TO 03 UTC WEDNESDAY AND BEGINS TO DIMINISH WEDNESDAY EVENING.
TRIED TO SHOW SOME SNOW UP IN THE NW AREAS BUT KEPT AMOUNT ON THE
LOW SIDE. BLENDED LARGE SCALE MODELS WITH 21Z SREF TO REFINE THE
AREA OF POPS AND QPF. QPF AMOUNTS WERE OF COURSE LOW.
CLEARLY WEDNESDAY SHOULD BE ABOUT THE COLDEST DAY OF THE WINTER
TO DATE WITH THE -16C CONTOUR DRAPED OVER CENTRAL PA AND AT LEAST
-1SD BELOW NORMAL TEMPERATURES. THAT IS 5 TO 10F BELOW NORMAL.
THE COLD AT LEAST WILL CONTINUE INTO NEW YEARS DAY (SEE BELOW) AS
THE HIGH LUMBERS BY TO OUR SOUTH.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
STRONG HIGH PRESSURE OVER THE CENTRAL U.S. THIS MIDWEEK WILL
WEAKEN AND DRIFT TOWARD THE CAROLINAS BY FRIDAY AS A WEAK WAVE
SLIDES QUICKLY ACROSS THE GREAT LAKES. THIS WILL BRING AN
EXTENDED PERIOD OF FAIR BUT COOLER THAN NORMAL WEATHER TO THE
FORECAST AREA. SOME SNOW SHOWERS MAY IMPACT THE NW MTNS...BUT
MOST OF THE SNOW SHOWER ACTIVITY WILL REMAIN NORTH OF THE PA
BORDER. BREEZY CONDITIONS WED NIGHT INTO THU IN FAST FLOW WILL
RESULT IN SINGLE DIGIT WIND CHILLS OVER NORTHERN AND WESTERN PARTS
OF THE CWA AS WE RING IN THE NEW YEAR.
GEFS AND OTHER LONG RANGE GUIDANCE SHOW THE FIRST NOTABLE STORM
OF 2015 DEVELOPING FOR NEXT WEEKEND. TIMING/STORM TRACK ISSUES
REMAIN WITH MUCH UNCERTAINTY IN EVOLUTION OF THIS SYSTEM...BUT
GUIDANCE IMPLIES A POTENTIAL MIXED PRECIPITATION EVENT FROM
GENERALLY SAT AFT THROUGH FIRST HALF OF SUNDAY. GFS CONTINUES TO
BRINGS A LOW UP THE OHIO VALLEY TO OUR WEST...PUSHING A SHOT OF
MILDER AIR BACK INTO THE STATE WITH RAIN LIKELY BECOMING THE MOST
DOMINANT PRECIPITATION TYPE /WITH FREEZING PRECIP POSS AT ONSET/.
IN CONTRAST...THE OPERATIONAL ECMWF REMAINING FIRM ON BRINGING
THE SURFACE LOW SOUTH AND EAST OF PA WHICH WOULD RESULT IN COLDER
AIR AND A MORE MIXED BAG OF PRECIPITATION TYPES. THE EC MEAN IS A
BIT MORE AGGRESSIVE DEVELOPING THE LOW...POTENTIALLY MAKING THE
OPERATIONAL RUN AN OUTLIER. FOR NOW...DIDN/T MAKE ANY LARGE
CHANGES TO FORECAST OVER THE WEEKEND AND HELD ON TO THE POTENTIAL
FOR A MIX OF WINTRY PRECIP - ESP ACROSS CENTRAL AND NORTHERN
PA...AND LEANED MORE TOWARD RAIN IN THE LOWER SUSQ.
QUICK SHOT OF COLDER AIR TO START NEXT WEEK...WITH CHANCE FOR
ANOTHER LOW SLIDING EASTWARD FROM THE GREAT LAKES INTO NEW ENGLAND
MIDWEEK WITH CHANCE OF SNOW FOR PA.
&&
.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
MVFR CIGS WILL LIKELY REMAIN IN PLACE AT BFD INTO TUESDAY WITH
NORTHWESTERLY WINDS AND A CHILLY...SHALLOW AIR MASS. CONTINUED
NORTHWESTERLY FLOW WILL MAKE A FEW FLURRIES AT BFD...BUT THE REST
OF THE TERMINALS WILL REMAIN DRY AND ONLY JST MAY SEE MVFR CIGS
OVERNIGHT. CLOUDS MAY LOWER AT IPT/UNV AS THE LOW CLOUD DECK
ASSOCIATED WITH THE COLDER AIR SLIDING DOWN FROM THE NORTH MOVES
SOUTHWARD. BUT...WILL KEEP IT AS VFR THRU THE TAF PERIOD FOR THE
TIME BEING.
HIGH PRESSURE CENTERED OVER THE FRONT RANGE OF THE ROCKIES AND THE
GREAT PLAINS WILL STRETCH FAR TO THE EAST AND GRADUALLY SINK
SOUTHWARD. A BRIEF SHOT OF COLDER AIR WITHIN A FEW HOURS OF 12Z
WED MAY CREATE A BROADER AREA OF SHSN/SQ. BUT THE REDUCTIONS IN
VIS/CIG SHOULD BE LIMITED TO BFD...AND NOT EVEN JST. THE WAVE
ALOFT WILL BE ACCOMPANIED BY VERY LITTLE MOISTURE. WINDS COULD
BECOME GUSTY...THOUGH.
OUTLOOK...
WED-FRI...VFR.
SAT...MVFR/IFR POSS IN WINTRY PRECIP.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...GRUMM
SHORT TERM...GRUMM
LONG TERM...RXR
AVIATION...DANGELO/GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
904 PM EST MON DEC 29 2014
.SYNOPSIS...
A COLD STRETCH OF WEATHER IS IN STORE FOR CENTRAL PA WITH
TEMPERATURES BELOW SEASONAL NORMALS FOR THE REST OF THE WEEK. WEAK
DISTURBANCES WILL BRING FLURRIES OVER THE WEST AND NORTH AT TIMES.
THE NEXT CHANCE FOR MEANINGFUL PRECIPITATION WILL NOT BE UNTIL THE
WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
ADJUSTED THE FORECAST WITH NEWER GUIDANCE. ALL CHANGES MINOR.
SATELLITE SHOWS LOWER CLOUDS TO THE NORTH AND CIRRUS TO OUR SOUTH.
THE LARGER SCALE GUIDANCE SHOWS THE IMPLIED CLOUDS OVER THE ENTIRE
REGION WHILE THE HRRR SHOWS THE RELATIVE CLEAR SLOT OVER PORTIONS
OF CENTRAL PA WHICH IS IN THE 11-3.9 MICRON DATA. THE CLOUDS IN
THE NORTH GET REINFORCED OVERNIGHT AND THE CLEAR TO PARTLY CLEAR
AREA IN THE HRRR DRIFTS TO THE SOUTH AND EAST. PORTIONS OF CENTRAL
AND SOUTHEASTERN SHOULD BE PARTLY CLEAR AT TIMES.
THE HRRR ALSO SHOWS...LIKE A FEW OTHER MODELS SOME VERY LIGHT SNOW
SHOWERS OR FLURRIES IN THE NORTHWEST OVERNIGHT. NOTHING OF NOTE.
MOSTLY NORTH-NORTHWEST FLOW ON COLD SIDE OF THE BIG ANTICYCLONE TO
OUR WEST.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY/...
MINOR TWEAKS TO FORECAST WITH LATEST GUIDANCE. MODELS BEGIN TO
SHOW THE IMPACT OF THE CONTINUED NORTHERLY FLOW WITH CHANCE AND
SLIGHT CHANCE POPS OVER THE NORTHWEST. THE FLOW IS ON THE COLD
SIDE OF A MASSIVE SURFACE ANTICYCLONE TO OUR WEST.
AS PER THE SNOW SHOWERS...INITIALLY SREF AND EC-EFS SHOW THE LES
MAINLY IN NY BUT OVERTIME MAINLY LATE TUESDAY INTO
WEDNESDAY...THEY SHOW THE EVOLUTION OF BETTER LAKE ERIE SNOW
SHOWER POTENTIAL INTO NW PA. EDGED UP POPS TUESDAY INTO WEDNESDAY
AS THE -18C AIR AT 850 MB SETTLE OVER NORTHERN AREAS OF THE STATE.
CLEARLY...WE ARE GOING TO SEE IT GET INCREMENTALLY COLDER OVER THE
NEXT FEW DAYS BOTTOMING OUT AROUND NEW YEARS DAY (SEE BELOW)...AS
NOTED IN PREVIOUS DISCUSSION: MAX TEMPS TUES AND WED WILL BE 5-10F
BELOW NORMALS. THIS IS NOTEWORTHY BECAUSE WE HAVE ONLY HAD ONE OR
TWO DAYS BELOW NORMAL SINCE THE LIGHT SNOW THAT FELL ON THE
10TH/11TH. AVERAGE TEMPS FOR THE LAST 6 DAYS HAVE BEEN 10-20F
ABOVE NORMAL EACH DAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
STRONG HIGH PRESSURE OVER THE CENTRAL U.S. THIS MIDWEEK WILL
WEAKEN AND DRIFT TOWARD THE CAROLINAS BY FRIDAY AS A WEAK WAVE
SLIDES QUICKLY ACROSS THE GREAT LAKES. THIS WILL BRING AN
EXTENDED PERIOD OF FAIR BUT COOLER THAN NORMAL WEATHER TO THE
FORECAST AREA. SOME SNOW SHOWERS MAY IMPACT THE NW MTNS...BUT
MOST OF THE SNOW SHOWER ACTIVITY WILL REMAIN NORTH OF THE PA
BORDER. BREEZY CONDITIONS WED NIGHT INTO THU IN FAST FLOW WILL
RESULT IN SINGLE DIGIT WIND CHILLS OVER NORTHERN AND WESTERN PARTS
OF THE CWA AS WE RING IN THE NEW YEAR.
GEFS AND OTHER LONG RANGE GUIDANCE SHOW THE FIRST NOTABLE STORM
OF 2015 DEVELOPING FOR NEXT WEEKEND. TIMING/STORM TRACK ISSUES
REMAIN WITH MUCH UNCERTAINTY IN EVOLUTION OF THIS SYSTEM...BUT
GUIDANCE IMPLIES A POTENTIAL MIXED PRECIPITATION EVENT FROM
GENERALLY SAT AFT THROUGH FIRST HALF OF SUNDAY. GFS CONTINUES TO
BRINGS A LOW UP THE OHIO VALLEY TO OUR WEST...PUSHING A SHOT OF
MILDER AIR BACK INTO THE STATE WITH RAIN LIKELY BECOMING THE MOST
DOMINANT PRECIPITATION TYPE /WITH FREEZING PRECIP POSS AT ONSET/.
IN CONTRAST...THE OPERATIONAL ECMWF REMAINING FIRM ON BRINGING
THE SURFACE LOW SOUTH AND EAST OF PA WHICH WOULD RESULT IN COLDER
AIR AND A MORE MIXED BAG OF PRECIPITATION TYPES. THE EC MEAN IS A
BIT MORE AGGRESSIVE DEVELOPING THE LOW...POTENTIALLY MAKING THE
OPERATIONAL RUN AN OUTLIER. FOR NOW...DIDN/T MAKE ANY LARGE
CHANGES TO FORECAST OVER THE WEEKEND AND HELD ON TO THE POTENTIAL
FOR A MIX OF WINTRY PRECIP - ESP ACROSS CENTRAL AND NORTHERN
PA...AND LEANED MORE TOWARD RAIN IN THE LOWER SUSQ.
QUICK SHOT OF COLDER AIR TO START NEXT WEEK...WITH CHANCE FOR
ANOTHER LOW SLIDING EASTWARD FROM THE GREAT LAKES INTO NEW ENGLAND
MIDWEEK WITH CHANCE OF SNOW FOR PA.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
MVFR CIGS WILL LIKELY REMAIN IN PLACE AT BFD INTO TUESDAY WITH
NORTHWESTERLY WINDS AND A CHILLY...SHALLOW AIR MASS. CONTINUED
NORTHWESTERLY FLOW WILL MAKE A FEW FLURRIES AT BFD...BUT THE REST
OF THE TERMINALS WILL REMAIN DRY AND ONLY JST MAY SEE MVFR CIGS
OVERNIGHT. CLOUDS MAY LOWER AT IPT/UNV AS THE LOW CLOUD DECK
ASSOCIATED WITH THE COLDER AIR SLIDING DOWN FROM THE NORTH MOVES
SOUTHWARD. BUT...WILL KEEP IT AS VFR THRU THE TAF PERIOD FOR THE
TIME BEING.
HIGH PRESSURE CENTERED OVER THE FRONT RANGE OF THE ROCKIES AND THE
GREAT PLAINS WILL STRETCH FAR TO THE EAST AND GRADUALLY SINK
SOUTHWARD. A BRIEF SHOT OF COLDER AIR WITHIN A FEW HOURS OF 12Z
WED MAY CREATE A BROADER AREA OF SHSN/SQ. BUT THE REDUCTIONS IN
VIS/CIG SHOULD BE LIMITED TO BFD...AND NOT EVEN JST. THE WAVE
ALOFT WILL BE ACCOMPANIED BY VERY LITTLE MOISTURE. WINDS COULD
BECOME GUSTY...THOUGH.
OUTLOOK...
WED-FRI...VFR.
SAT...MVFR/IFR POSS IN WINTRY PRECIP.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...GRUMM
SHORT TERM...GRUMM/DANGELO
LONG TERM...RXR
AVIATION...DANGELO/GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
712 PM EST MON DEC 29 2014
.SYNOPSIS...
A COLD STRETCH OF WEATHER IS IN STORE FOR CENTRAL PA WITH
TEMPERATURES BELOW SEASONAL NORMALS FOR THE REST OF THE WEEK. WEAK
DISTURBANCES WILL BRING FLURRIES OVER THE WEST AND NORTH AT TIMES.
THE NEXT CHANCE FOR MEANINGFUL PRECIPITATION WILL NOT BE UNTIL THE
WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
ADJUSTED THE FORECAST WITH NEWER GUIDANCE. ALL CHANGES MINOR.
SATELLITE SHOWS LOWER CLOUDS TO THE NORTH AND CIRRUS TO OUR SOUTH.
THE LARGER SCALE GUIDANCE SHOWS THE IMPLIED CLOUDS OVER THE ENTIRE
REGION WHILE THE HRRR SHOWS THE RELATIVE CLEAR SLOT OVER PORTIONS
OF CENTRAL PA WHICH IS IN THE 11-3.9 MICRON DATA. THE CLOUDS IN
THE NORTH GET REINFORCED OVERNIGHT AND THE CLEAR TO PARTLY CLEAR
AREA IN THE HRRR DRIFTS TO THE SOUTH AND EAST. PORTIONS OF CENTRAL
AND SOUTHEASTERN SHOULD BE PARTLY CLEAR AT TIMES.
THE HRRR ALSO SHOWS...LIKE A FEW OTHER MODELS SOME VERY LIGHT SNOW
SHOWERS OR FLURRIES IN THE NORTHWEST OVERNIGHT. NOTHING OF NOTE.
MOSTLY NORTH-NORTHWEST FLOW ON COLD SIDE OF THE BIG ANTICYCLONE TO
OUR WEST.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY/...
MINOR TWEAKS TO FORECAST WITH LATEST GUIDANCE. MODELS BEGIN TO
SHOW THE IMPACT OF THE CONTINUED NORTHERLY FLOW WITH CHANCE AND
SLIGHT CHANCE POPS OVER THE NORTHWEST. THE FLOW IS ON THE COLD
SIDE OF A MASSIVE SURFACE ANTICYCLONE TO OUR WEST.
AS PER THE SNOW SHOWERS...INITIALLY SREF AND EC-EFS SHOW THE LES
MAINLY IN NY BUT OVERTIME MAINLY LATE TUESDAY INTO
WEDNESDAY...THEY SHOW THE EVOLUTION OF BETTER LAKE ERIE SNOW
SHOWER POTENTIAL INTO NW PA. EDGED UP POPS TUESDAY INTO WEDNESDAY
AS THE -18C AIR AT 850 MB SETTLE OVER NORTHERN AREAS OF THE STATE.
CLEARLY...WE ARE GOING TO SEE IT GET INCREMENTALLY COLDER OVER THE
NEXT FEW DAYS BOTTOMING OUT AROUND NEW YEARS DAY (SEE BELOW)...AS
NOTED IN PREVIOUS DISCUSSION: MAX TEMPS TUES AND WED WILL BE 5-10F
BELOW NORMALS. THIS IS NOTEWORTHY BECAUSE WE HAVE ONLY HAD ONE OR
TWO DAYS BELOW NORMAL SINCE THE LIGHT SNOW THAT FELL ON THE
10TH/11TH. AVERAGE TEMPS FOR THE LAST 6 DAYS HAVE BEEN 10-20F
ABOVE NORMAL EACH DAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
STRONG HIGH PRESSURE OVER THE CENTRAL U.S. THIS MIDWEEK WILL
WEAKEN AND DRIFT TOWARD THE CAROLINAS BY FRIDAY AS A WEAK WAVE
SLIDES QUICKLY ACROSS THE GREAT LAKES. THIS WILL BRING AN
EXTENDED PERIOD OF FAIR BUT COOLER THAN NORMAL WEATHER TO THE
FORECAST AREA. SOME SNOW SHOWERS MAY IMPACT THE NW MTNS...BUT
MOST OF THE SNOW SHOWER ACTIVITY WILL REMAIN NORTH OF THE PA
BORDER. BREEZY CONDITIONS WED NIGHT INTO THU IN FAST FLOW WILL
RESULT IN SINGLE DIGIT WIND CHILLS OVER NORTHERN AND WESTERN PARTS
OF THE CWA AS WE RING IN THE NEW YEAR.
GEFS AND OTHER LONG RANGE GUIDANCE SHOW THE FIRST NOTABLE STORM
OF 2015 DEVELOPING FOR NEXT WEEKEND. TIMING/STORM TRACK ISSUES
REMAIN WITH MUCH UNCERTAINTY IN EVOLUTION OF THIS SYSTEM...BUT
GUIDANCE IMPLIES A POTENTIAL MIXED PRECIPITATION EVENT FROM
GENERALLY SAT AFT THROUGH FIRST HALF OF SUNDAY. GFS CONTINUES TO
BRINGS A LOW UP THE OHIO VALLEY TO OUR WEST...PUSHING A SHOT OF
MILDER AIR BACK INTO THE STATE WITH RAIN LIKELY BECOMING THE MOST
DOMINANT PRECIPITATION TYPE /WITH FREEZING PRECIP POSS AT ONSET/.
IN CONTRAST...THE OPERATIONAL ECMWF REMAINING FIRM ON BRINGING
THE SURFACE LOW SOUTH AND EAST OF PA WHICH WOULD RESULT IN COLDER
AIR AND A MORE MIXED BAG OF PRECIPITATION TYPES. THE EC MEAN IS A
BIT MORE AGGRESSIVE DEVELOPING THE LOW...POTENTIALLY MAKING THE
OPERATIONAL RUN AN OUTLIER. FOR NOW...DIDN/T MAKE ANY LARGE
CHANGES TO FORECAST OVER THE WEEKEND AND HELD ON TO THE POTENTIAL
FOR A MIX OF WINTRY PRECIP - ESP ACROSS CENTRAL AND NORTHERN
PA...AND LEANED MORE TOWARD RAIN IN THE LOWER SUSQ.
QUICK SHOT OF COLDER AIR TO START NEXT WEEK...WITH CHANCE FOR
ANOTHER LOW SLIDING EASTWARD FROM THE GREAT LAKES INTO NEW ENGLAND
MIDWEEK WITH CHANCE OF SNOW FOR PA.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
MVFR CIGS WILL LIKELY REMAIN IN PLACE AT BFD INTO TUESDAY WITH
NORTHWESTERLY WINDS AND A CHILLY...SHALLOW AIR MASS. CONTINUED
NORTHWESTERLY FLOW WILL MAKE A FEW FLURRIES AT BFD...BUT THE REST
OF THE TERMINALS WILL REMAIN DRY AND ONLY JST MAY SEE MVFR CIGS
THIS AFTN/EVENING. CLOUDS MAY LOWER AT IPT/UNV AS THE LOW CLOUD
DECK ASSOCIATED WITH THE COLDER AIR SLIDING DOWN FROM THE NORTH
MOVES SOUTHWARD. BUT...WILL KEEP IT AS VFR THRU THE TAF PERIOD FOR
THE TIME BEING.
HIGH PRESSURE CENTERED OVER THE FRONT RANGE OF THE ROCKIES AND THE
GREAT PLAINS WILL STRETCH FAR TO THE EAST AND GRADUALLY SINK
SOUTHWARD. A BRIEF SHOT OF COLDER AIR WITHIN A FEW HOURS OF 12Z
WED MAY CREATE A BROADER AREA OF SHSN/SQ. BUT THE REDUCTIONS IN
VIS/CIG SHOULD BE LIMITED TO BFD...AND NOT EVEN JST. THE WAVE
ALOFT WILL BE ACCOMPANIED BY VERY LITTLE MOISTURE. WINDS COULD
BECOME GUSTY...THOUGH.
OUTLOOK...
WED-FRI...VFR.
SAT...MVFR/IFR POSS IN WINTRY PRECIP.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...GRUMM
SHORT TERM...GRUMM/DANGELO
LONG TERM...RXR
AVIATION...DANGELO
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
701 AM EST SUN DEC 28 2014
.SYNOPSIS...
A COLD FRONT WILL BRING RAIN SHOWERS TONIGHT AND SUNDAY. THE
SHOWERS WILL BECOME MIXED WITH A LITTLE SNOW ACROSS THE WESTERN
MOUNTAINS THE MORNING. COLDER AND DRIER AIR WILL CONTINUE TO
FILTER INTO THE AREA FOR THE NEXT SEVERAL DAYS WITH TEMPERATURES
RETURNING BACK TO SEASONAL NORMALS...WHICH WILL FEEL QUITE COLD
CONSIDERING HOW WARM IT HAS BEEN RECENTLY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
TRACKING SEVERAL BANDS OF FAST MOVING SHOWER ACTIVITY MAINLY
ACROSS W AND N CWA AT 0830Z. IN GENERAL THE SHOWERS HAVE WEAKENED
AS THEY ADVANCE EAST. MOST ORGANIZED AREA OF SHOWERS ENTERING WEST
COUNTIES RIGHT NOW. HRRR WEAKENS THIS BAND AS IT MOVES DEEPER
INTO THE CWA...THOUGH EXPECT MOST OF THE AREA TO PICK UP SOME
MEASURABLE RAINFALL THIS MORNING. COLDER AIR ALSO ACCOMPANYING
THESE SHOWERS AND MOST OF THE AREA WILL SEE FALLING OR STEADY
TEMPERATURES TODAY. SHOWERS WILL MIX AND CHANGE OVER TO SNOW
ACROSS WESTERN MOUNTAINS WITH ONLY LIGHT ACCUMULATIONS EXPECTED.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
FRONTAL BAND SLOW SHIFTS SOUTH OF CWA THIS EVENING WITH ORGANIZED
SHOWERS WANING. SHOWERS ACROSS PA/MD BORDER MAY HAVE ENOUGH COLD
AIR MAY ARRIVE TO RESULT IN SNOW BUT QPF WILL BE VERY LIGHT AND NO
ACCUMULATIONS ARE EXPECTED. QUIET WEATHER ON MONDAY WITH
TEMPERATURES COOLER THEN PAST SEVERAL DAYS BUT STILL ABOVE AVERAGE
FOR LATE DEC.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
AS MENTIONED IN PREVIOUS DISCUSSIONS...A WAVE DEVELOPS SOUTH OF
THE AREA AND TRACKS NORTHEAST. MORE CONFIDENCE THAT IMPACTS FROM
THIS SYSTEM WILL STAY WELL SOUTH AND EAST OF THE CWA MON NIGHT AND
TUE.
HIGH PRESSURE WILL BUILD OVER THE MIDDLE OF THE COUNTY BY MIDWEEK
AND SLOWLY DRIFT OFF THE EAST COAST BY THE END OF THE
WORKWEEK...BRINGING AN EXTENDED PERIOD OF FAIR WEATHER TO THE
FORECAST AREA. HOWEVER...WAVES OF COLDER AIR DIVING DOWN FROM THE
NORTH WILL HELP TEMPERATURES WILL RETURN TO NORMAL FOR THE LAST WEEK
OF DECEMBER. COOLER AIR AND BREEZY CONDITIONS WILL RESULT IN
SINGLE DIGIT WIND CHILLS OVER NORTHERN AND WESTERN PARTS OF THE
CWA AS WE RING IN THE NEW YEAR.
GEFS AND LONG RANGE GUIDANCE SHOWS THE FIRST SIGNIFICANT STORM OF
2015 DEVELOPS NEXT WEEKEND. STORM TRACK WILL BE CRITICAL AS TO
WHAT TYPE OF PRECIPITATION FALLS ACROSS THE AREA. RIGHT NOW IT
LOOKS LIKE THE SURFACE LOW WILL TRACK WEST OF PA BRINGING ANOTHER
SHOT OF MILD AIR BACK INTO THE STATE WITH RAIN THE LIKELY DOMINANT
PRECIPITATION TYPE. HOWEVER THERE IS STILL MUCH UNCERTAINTY GIVEN
THAT THIS SYSTEM IS ALMOST A WEEK OUT.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
THE STRONG BAND THAT WAS ALONG THE COLD FRONT HAS DISSIPATED AS
IT MOVED EASTWARD. REDUCING CONDITIONS REMAIN THROUGH THE WESTERN
TAF SITES DUE TO THE UPSLOPE FLOW AND SHOWERS FROM THE RESIDUAL
MOISTURE. EXPECT IFR AND LOWER AT BFD AND JST THROUGH MID MORNING.
AS PRECIP FADES CIGS AND VSBYS WILL IMPROVE...THOUGH REDUCINGCIGS
OF MVFR AND LOWER SHOULD REMAIN THROUGH THE EARLY AFTERNOON HOURS.
LIGHT SHOWERS REMAIN POSSIBLE THROUGH THE LOWER SUSQ TAF
SITES...THOUGH MVFR SHOULD BE THE MAIN CONCERN WITH IMPROVING
CONDITIONS BY LATE MORNING. VFR SHOULD RETURN LATE TODAY AS
CLEARING SPREADS TO THE SOUTH AS THE FRONT PRESSES SLOWLY SOUTH
THRU THE MID- ATLANTIC - EVENTUALLY STALLING OUT THERE. MVFR COULD
RETURN TO JST TONIGHT INTO MONDAY MORNING.
OUTLOOK...
MON-THU...MAINLY VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...ROSS
NEAR TERM...ROSS
SHORT TERM...ROSS
LONG TERM...ROSS/HAGNER
AVIATION...CERU/GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
348 AM EST SUN DEC 28 2014
.SYNOPSIS...
A COLD FRONT WILL BRING RAIN SHOWERS TONIGHT AND SUNDAY. THE
SHOWERS WILL BECOME MIXED WITH A LITTLE SNOW ACROSS THE WESTERN
MOUNTAINS THE MORNING. COLDER AND DRIER AIR WILL CONTINUE TO
FILTER INTO THE AREA FOR THE NEXT SEVERAL DAYS WITH TEMPERATURES
RETURNING BACK TO SEASONAL NORMALS...WHICH WILL FEEL QUITE COLD
CONSIDERING HOW WARM IT HAS BEEN RECENTLY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
TRACKING SEVERAL BANDS OF FAST MOVING SHOWER ACTIVITY MAINLY
ACROSS W AND N CWA AT 0830Z. IN GENERAL THE SHOWERS HAVE WEAKENED
AS THEY ADVANCE EAST. MOST ORGANIZED AREA OF SHOWERS ENTERING WEST
COUNTIES RIGHT NOW. HRRR WEAKENS THIS BAND AS IT MOVES DEEPER
INTO THE CWA...THOUGH EXPECT MOST OF THE AREA TO PICK UP SOME
MEASURABLE RAINFALL THIS MORNING. COLDER AIR ALSO ACCOMPANYING
THESE SHOWERS AND MOST OF THE AREA WILL SEE FALLING OR STEADY
TEMPERATURES TODAY. SHOWERS WILL MIX AND CHANGE OVER TO SNOW
ACROSS WESTERN MOUNTAINS WITH ONLY LIGHT ACCUMULATIONS EXPECTED.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
FRONTAL BAND SLOW SHIFTS SOUTH OF CWA THIS EVENING WITH ORGANIZED
SHOWERS WANING. SHOWERS ACROSS PA/MD BORDER MAY HAVE ENOUGH COLD
AIR MAY ARRIVE TO RESULT IN SNOW BUT QPF WILL BE VERY LIGHT AND NO
ACCUMULATIONS ARE EXPECTED. QUIET WEATHER ON MONDAY WITH
TEMPERATURES COOLER THEN PAST SEVERAL DAYS BUT STILL ABOVE AVERAGE
FOR LATE DEC.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
AS MENTIONED IN PREVIOUS DISCUSSIONS...A WAVE DEVELOPS SOUTH OF
THE AREA AND TRACKS NORTHEAST. MORE CONFIDENCE THAT IMPACTS FROM
THIS SYSTEM WILL STAY WELL SOUTH AND EAST OF THE CWA MON NIGHT AND
TUE.
HIGH PRESSURE WILL BUILD OVER THE MIDDLE OF THE COUNTY BY MIDWEEK
AND SLOWLY DRIFT OFF THE EAST COAST BY THE END OF THE
WORKWEEK...BRINGING AN EXTENDED PERIOD OF FAIR WEATHER TO THE
FORECAST AREA. HOWEVER...WAVES OF COLDER AIR DIVING DOWN FROM THE
NORTH WILL HELP TEMPERATURES WILL RETURN TO NORMAL FOR THE LAST WEEK
OF DECEMBER. COOLER AIR AND BREEZY CONDITIONS WILL RESULT IN
SINGLE DIGIT WIND CHILLS OVER NORTHERN AND WESTERN PARTS OF THE
CWA AS WE RING IN THE NEW YEAR.
GEFS AND LONG RANGE GUIDANCE SHOWS THE FIRST SIGNIFICANT STORM OF
2015 DEVELOPS NEXT WEEKEND. STORM TRACK WILL BE CRITICAL AS TO
WHAT TYPE OF PRECIPITATION FALLS ACROSS THE AREA. RIGHT NOW IT
LOOKS LIKE THE SURFACE LOW WILL TRACK WEST OF PA BRINGING ANOTHER
SHOT OF MILD AIR BACK INTO THE STATE WITH RAIN THE LIKELY DOMINANT
PRECIPITATION TYPE. HOWEVER THERE IS STILL MUCH UNCERTAINTY GIVEN
THAT THIS SYSTEM IS ALMOST A WEEK OUT.
&&
.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
COLD FRONT MOVING THROUGH THE STATE OVERNIGHT. SFC MOISTURE
CONTINUES TO INCREASE AS LIGHT PRECIP MOVES THROUGH THE NORTHERN
HALF OF THE STATE. VFR SHOULD CONTINUE THROUGH THE SOUTHERN TAF
SITES OVER THE NEXT FEW HOURS.
RAIN SHOWERS ALONG AND AHEAD OF THE FRONT HAVE BROUGHT A LOWERING
OF VISBYS AND CIGS TO BFD CURRENTLY...AND IFR CIGS/VIS ARE
EXPECTED TO DEVELOP IN THE WESTERN MOUNTAINS OVERNIGHT TO PERHAPS
AOO/UNV/IPT AND JST. BFD WILL LIKELY BEGIN TO SEE SNOW MIX IN OR
A CHANGE TO ALL SNOW AND THEREFORE THE ATTENDANT LOWER VISBYS
AROUND SUNRISE/12Z. JST MAY LOWER TO LIFR AS WELL...MAINLY DUE TO
THE PERSISTENT UPSLOPE...BUT ALSO IF THE PRECIP TURNS TO SNOW
THERE IN THE MORNING.
COLD FRONT SHOULD BE THRU HALF OF THE REGION BY 12Z...BUT IT WILL
TAKE THE REST OF THE DAYLIGHT FOR IT TO CLEAR THE SE. LOWER CLOUDS
WILL HANG ON THROUGH THE AFTN...BUT VFR MAY RETURN BY 00Z/29TH -
IN THE NORTH FIRST THEN CLEARING SPREADS TO THE SOUTH AS THE FRONT
PRESSES SLOWLY SOUTH THRU THE MID-ATLANTIC - EVENTUALLY STALLING
OUT THERE.
OUTLOOK...
MON-THU...MAINLY VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...ROSS
NEAR TERM...ROSS
SHORT TERM...ROSS
LONG TERM...ROSS/HAGNER
AVIATION...CERU/GARTNER
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
123 PM EST SUN DEC 28 2014
.SYNOPSIS...
A COLD FRONT WILL SLOWLY CROSS OUR REGION THROUGH MONDAY...THOUGH
SOME MOISTURE WILL LINGER UNTIL TUESDAY. DRIER AND COOLER HIGH
PRESSURE WILL MOVE ACROSS THE AREA WEDNESDAY AND THURSDAY. ANOTHER
LOW PRESSURE SYSTEM THEN SHOULD BEGIN TO TAKE SHAPE AT THE END OF
THE WEEK...BRINGING PRECIPITATION BACK TO THE AREA BY FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
1045 AM EST UPDATE...A BAND OF LIGHT TO MODERATE RAIN CURRENTLY OVER
THE SOUTHERN TIER OF THE CWA IS EXPECTED TO EXIT EAST OF THE AREA BY
NOON...WITH A DRY SLOT MOVING IN THRU THE REST OF THE REGION THRU
THIS AFTERNOON. HENCE...POPS WERE LOWERED INTO THE SLIGHT CHANCE
RANGE OVER THE PIEDMONT...AND LOW END CHANCE RANGE IN THE MTNS ZONES
BETWEEN 18Z AND 00Z SUN...BEFORE RAMPING BACK UP FROM NW TO SE THRU
TONIGHT AS ANOTHER BAND OF PRECIP ASSOCIATED WITH AN UPPER TROUGH
AXIS APPROACHES FROM THE WEST.
910 AM EST UPDATE...HAVE RAISED POPS TO 90/100 RANGE THIS MORNING
OVER THE SOUTHERN HALF OF THE CWA PER LATEST RADAR TREND. THIS IS
WELL IN LINE WITH THE LATEST HRRR WHERE THE HEAVIEST RAIN BAND WILL
MOVE ACROSS ALONG AND SOUTHEAST OF THE I-85 THIS MORNING THRU
MIDDAY. ALSO...HAVE INCLUDED AREAS OF PATCHY FOG TO ACCOUNT FOR THE
LATEST SURFACE OBS.
AS OF 645 AM...RAIN SHIELD HAS MADE VERY LITTLE NORTHWARD PROGRESS
ABOVE (ROUGHLY) I-85 THIS MORNING...AND AM BEGINNING TO WONDER IF
THE PRECIP ISN/T GOING TO JUST FIZZLE MORE OR LESS IN PLACE...AS
UPGLIDE WEAKENS...AND THE MID-LEVELS DRY OUT. WILL CONTINUE TO
FEATURE HIGH POPS (60-80) ACROSS OUR NC ZONES...BUT THESE HAVE BEEN
SCALED BACK FROM THE EARLIER FORECAST. OTHERWISE...TEMPS ARE
EXPECTED TO REMAIN MORE OR LESS STEADY THIS MORNING UNDER DENSE
CLOUD COVER.
AREA OF MODERATE RAIN IS FINALLY PUSHING ACROSS THE UPPER SAVANNAH
RIVER VALLEY THIS MORNING. IN GENERAL...THIS IS FARTHER SOUTH THAN
WHAT THE MODELS HAVE RECENTLY BEEN DEPICTING...AND THE HIGHEST QPF
FOR THIS MORNING HAS BEEN ADJUSTED TO THE UPSTATE AND NORTHEAST
GA...WHERE RAINFALL AMOUNTS THIS MORNING SHOULD RANGE FROM ONE
QUARTER TO ONE HALF INCH...WITH LOCALLY HIGHER AMOUNTS. THE PRECIP
SHIELD IS EXPECTED TO SHIFT NORTHWARD WITH TIME...AS THE BROAD BAND
OF ISENTROPIC LIFT TRANSLATES NORTHEAST TOWARD THE MID-ATLANTIC.
THEREFORE...THE MOUNTAINS AND FOOTHILLS OF WESTERN NC MAY YET SEE UP
TO A HALF INCH OF RAINFALL THIS MORNING...WITH LIGHTER AMOUNTS
TOWARD THE I-77 CORRIDOR.
AS UPGLIDE SHUTS OFF AND MID-LEVELS DRY OUT THIS AFTERNOON...PRECIP
SHOULD COME TO AN END...ALTHOUGH THE LOW LEVELS WILL REMAIN VERY
MOIST AND THERE MAY BE PATCHES OF DRIZZLE OR LIGHT RAIN LINGERING.
POPS WILL THEREFORE BE KEPT IN THE TOKEN CHANCE RANGE IN MOST AREAS
THROUGH THE AFTERNOON. WITH PRECIP FALLING INTO A DRY AIR MASS THIS
MORNING...FOLLOWED BY ABUNDANT LOW CLOUD COVER THROUGH THE
AFTERNOON...A WEAK IN-SITU CAD EVENT MAY RESULT...AND MAX TEMPS ARE
EXPECTED TO END UP BEING RATHER CLOSE TO CLIMO...DESPITE HIGH
THICKNESS VALUES FOR THE TIME OF YEAR.
A SHORT WAVE TROUGH EJECTING FROM TEXAS/THE LOWER MISS VALLEY
TONIGHT WILL DAMPEN AS IT ENCOUNTERS THE CONFLUENT UPPER FLOW ACROSS
THE EASTERN CONUS. NEVERTHELESS...A CONSENSUS OF MODEL GUIDANCE
DEPICTS WEAK CYCLOGENESIS OCCURRING ALONG A BAROCLINIC ZONE ACROSS
GEORGIA AND THE CAROLINAS...SUPPORTING ANOTHER ROUND OF RAINFALL
LATE TONIGHT INTO EARLY MONDAY...AND WARRANTING CATEGORICAL POPS IN
ALL AREAS ONCE AGAIN. ANOTHER ROUND OF .25-.50 INCH QPF APPEARS
LIKELY IN MOST AREAS.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 300 AM SUNDAY...PESKY FRONTAL ZONE FINALLY DOES LOOK TO BE
FORCED SOUTH AND EAST OF THE CWFA MONDAY AS A CANADIAN AIRMASS
EXPANDS OVER MOST OF THE ERN CONUS. COOLER AND DRIER AIR DO START TO
FILTER IN BY MONDAY NIGHT...BUT SOME LLVL MOISTURE DOES LINGER INTO
TUE. THE SOUTHEAST REMAINS UNDER BROADLY CYCLONIC FLOW THROUGH THAT
TIME...WITH AN EMBEDDED SHORTWAVE PROGGED TO MOVE FROM THE MID
MISSISSIPPI VALLEY TO THE DELMARVA BY TUE NIGHT. A WEAK BOUNDARY
ASSOCIATED WITH THIS WAVE WILL ENHANCE COLD ADVECTION AND LLVL LIFT
MON NIGHT/EARLY TUE...IN TIME TO ENCOUNTER THE MOISTURE. THUS POPS
EXHIBIT A SECONDARY PEAK TUE MRNG. AS WINDS VEER TO NW AROUND THAT
TIME...SOME UPSLOPE ENHANCEMENT IS ALSO EXPECTED WITH POPS TAKING A
LITTLE LONGER TO TAPER OFF TUE NEAR THE TENN BORDER. TEMPS ARE
EXPECTED TO REMAIN ABOVE CLIMO THROUGH TUE MRNG. PROFILES INDICATE AN
ACCORDINGLY WARM COLUMN...AND THE MOISTURE WILL BE CONCENTRATED IN
THE LOW TO MID LEVELS. ICE NUCLEATION AND SNOW PRODUCTION ARE
UNLIKELY...SO WITH TEMPS REMAINING ABOVE FREEZING THROUGHOUT THE CWFA
MON NIGHT NO MENTION OF WINTRY PRECIP HAS BEEN MADE.
IN THE WAKE OF THE BOUNDARY DEEPER DRYING BEGINS LATER TUE AND
CONTINUES THROUGH MID-WEEK...WITH SKIES TRENDING CLEARER. MAX TEMPS
WILL RETURN TO AROUND CLIMO TUE FOLLOWED BY SIMILARLY NORMAL TEMPS
FOR WED MRNG. DESPITE THE COLD ADVECTION...NOTABLY GUSTY WINDS ARE
NOT EXPECTED WITH THE LEADING EDGE OF THE AIRMASS HAVING ALREADY
PUSHED THROUGH.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 245 AM SUNDAY...REMARKABLY STRONG SFC HIGH PRESSURE OVER THE
CENTRAL PLAINS GETS SHUNTED SWD AS NRN STREAM SHORTWAVE DIVES INTO
THE MIDWEST AND PATTERN BEGINS TO REAMPLIFY OVER THE EAST. DRY AND
SEASONABLY COOL WEATHER WILL CONTINUE FOR OUR AREA WED-THU WITH TEMPS
NEAR CLIMO. THE SFC HIGH MOVES OVER THE SOUTHEAST BY THU NIGHT
INITIATING RETURN FLOW INTO THE WRN GULF STATES AS THE CUTOFF LOW
OVER THE DESERT SOUTHWEST PICKS UP SPEED. EVENTUALLY THAT WILL TRACK
ACRS THE MIDDLE OR LOWER MISSISSIPPI VALLEY...SPINNING UP A NEW
SYSTEM. AGREEMENT BETWEEN THE 28/00Z RUNS OF THE GFS AND EC IS
GENERALLY GOOD...NOW ONLY SHOWING MINOR DIFFERENCES IN THE SFC LOW
TRACK. REGARDLESS OF THE PRECISE TRACK PRECIP CHANCES BEGIN TO
INCREASE THU NIGHT BEFORE PEAKING SATURDAY. MODELS HINT AT SOME PTYPE
CONCERNS EARLY IN THE EVENT WITH A POSSIBLE IN-SITU CAD EVENT
DEVELOPING...BUT THE BULK OF THE PRECIP SHOULD BE RAIN WITH TEMPS
TRENDING ABOVE NORMAL BEYOND FRIDAY.
&&
.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
AT KCLT...A BRIEF PERIOD OF VFR/MVFR CIGS EARLY THIS AFTERNOON IN
RESPONSE TO INCREASING SW WINDS AHEAD OF AN APPROACHING SURFACE COLD
FRONT WILL QUICKLY GIVE WAY TO IFR CIGS...AS LATEST VISBY SATELLITE
SHOWS CONSIDERABLE IFR CLOUDS SPREADING BACK IN FROM THE SW. LATEST
GUIDANCE IS SUPPORTIVE OF LIFR CIGS THIS EVENING THRU THE END OF
THE TAF PERIOD. HENCE...HAVE MENTIONED 200-400FT RANGE CIGS BEYOND
22Z...CONTINUING THRU 18Z MON. SW WINDS WILL VEER TO THE NORTH AS
THE FRONT PUSHES THRU TONIGHT. AS A WAVE OF SURFACE LOW SETS UP OVER
THE WESTERN CAROLINAS...PRECIP WILL SPREAD OVER THE REGION AND WINDS
WILL VEER MORE TO THE NE BY MON MORNING. AREAS OF FOG WITH IFR
VISBY WILL AFFECT THE TERMINAL TONIGHT AND TOMORROW AS LLVL COOL AND
MOIST AIRMASS SPREADS FROM THE NE UNDERNEATH THE PERSISTING WAA SWLY
FLOW ALOFT.
ELSEWHERE...BKN TO SCT VISBY/MVFR CLOUDS CURRENTLY OVER THE NC MTNS
AND PORTIONS OF THE WESTERN NC PIEDMONT WILL GIVE WAY TO OVC IFR
CLOUDS BY LATE THIS AFTERNOON/EVENING AS A BAND OF PRECIP
ASSOCIATED WITH AN UPPER TROUGH AXIS PUSHES THRU THE AREA. ELSEWHERE
WILL SEE CONTINUED IFR CONDITIONS THRU THE PERIOD. AREAS OF FOG WITH
IFR VISBY WILL DEVELOP ACROSS MUCH OF THE REGION TONIGHT...MOIST AND
COOLER AIRMASS SPREADS IN FROM THE NE BEHIND THE DEPARTING COLD
FRONT. WITH A WAVE OF SURFACE LOW SETS UP ACROSS THE WESTERN
CAROLINAS BY EARLY MON...LIFR CLOUDS AND AREAS OF PRECIP WILL AFFECT
THE MOST LOCATIONS IN ITS WAKE. S/SW WINDS WILL VEER TO THE N
TONIGHT WITH THE FROPA...AND VEER TO THE NE BY MON MORNING.
OUTLOOK...PERIODS OF LIGHT RAIN AND FLIGHT RESTRICTIONS MAY LINGER
MONDAY AND MONDAY NIGHT BEFORE GRADUAL IMPROVEMENT OCCURS THROUGHOUT
TUESDAY. DRY HIGH PRESSURE SHOULD RETURN BY MID-WEEK.
CONFIDENCE TABLE...
18-24Z 00-06Z 06-12Z 12-18Z
KCLT MED 65% MED 66% MED 68% MED 68%
KGSP MED 76% MED 66% MED 61% MED 65%
KAVL MED 68% MED 62% MED 67% MED 76%
KHKY MED 62% LOW 55% MED 64% MED 76%
KGMU MED 72% MED 66% MED 64% MED 62%
KAND MED 72% MED 66% MED 67% MED 68%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...DEO
NEAR TERM...JDL/JOH
SHORT TERM...WIMBERLEY
LONG TERM...ARK/WIMBERLEY
AVIATION...JOH
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1043 AM EST SUN DEC 28 2014
.SYNOPSIS...
A COLD FRONT WILL SLOWLY CROSS OUR REGION THROUGH MONDAY...THOUGH
SOME MOISTURE WILL LINGER UNTIL TUESDAY. DRIER AND COOLER HIGH
PRESSURE WILL MOVE ACROSS THE AREA WEDNESDAY AND THURSDAY. ANOTHER
LOW PRESSURE SYSTEM THEN SHOULD BEGIN TO TAKE SHAPE AT THE END OF
THE WEEK...BRINGING PRECIPITATION BACK TO THE AREA BY FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
1045 AM EST UPDATE...A BAND OF LIGHT TO MODERATE RAIN CURRENTLY OVER
THE SOUTHERN TIER OF THE CWA IS EXPECTED TO EXIT EAST OF THE AREA BY
NOON...WITH A DRY SLOT MOVING IN THRU THE REST OF THE REGION THRU
THIS AFTERNOON. HENCE...POPS WERE LOWERED INTO THE SLIGHT CHANCE
RANGE OVER THE PIEDMONT...AND LOW END CHANCE RANGE IN THE MTNS ZONES
BETWEEN 18Z AND 00Z SUN...BEFORE RAMPING BACK UP FROM NW TO SE THRU
TONIGHT AS ANOTHER BAND OF PRECIP ASSOCIATED WITH AN UPPER TROUGH
AXIS APPROACHES FROM THE WEST.
910 AM EST UPDATE...HAVE RAISED POPS TO 90/100 RANGE THIS MORNING
OVER THE SOUTHERN HALF OF THE CWA PER LATEST RADAR TREND. THIS IS
WELL IN LINE WITH THE LATEST HRRR WHERE THE HEAVIEST RAIN BAND WILL
MOVE ACROSS ALONG AND SOUTHEAST OF THE I-85 THIS MORNING THRU
MIDDAY. ALSO...HAVE INCLUDED AREAS OF PATCHY FOG TO ACCOUNT FOR THE
LATEST SURFACE OBS.
AS OF 645 AM...RAIN SHIELD HAS MADE VERY LITTLE NORTHWARD PROGRESS
ABOVE (ROUGHLY) I-85 THIS MORNING...AND AM BEGINNING TO WONDER IF
THE PRECIP ISN/T GOING TO JUST FIZZLE MORE OR LESS IN PLACE...AS
UPGLIDE WEAKENS...AND THE MID-LEVELS DRY OUT. WILL CONTINUE TO
FEATURE HIGH POPS (60-80) ACROSS OUR NC ZONES...BUT THESE HAVE BEEN
SCALED BACK FROM THE EARLIER FORECAST. OTHERWISE...TEMPS ARE
EXPECTED TO REMAIN MORE OR LESS STEADY THIS MORNING UNDER DENSE
CLOUD COVER.
AREA OF MODERATE RAIN IS FINALLY PUSHING ACROSS THE UPPER SAVANNAH
RIVER VALLEY THIS MORNING. IN GENERAL...THIS IS FARTHER SOUTH THAN
WHAT THE MODELS HAVE RECENTLY BEEN DEPICTING...AND THE HIGHEST QPF
FOR THIS MORNING HAS BEEN ADJUSTED TO THE UPSTATE AND NORTHEAST
GA...WHERE RAINFALL AMOUNTS THIS MORNING SHOULD RANGE FROM ONE
QUARTER TO ONE HALF INCH...WITH LOCALLY HIGHER AMOUNTS. THE PRECIP
SHIELD IS EXPECTED TO SHIFT NORTHWARD WITH TIME...AS THE BROAD BAND
OF ISENTROPIC LIFT TRANSLATES NORTHEAST TOWARD THE MID-ATLANTIC.
THEREFORE...THE MOUNTAINS AND FOOTHILLS OF WESTERN NC MAY YET SEE UP
TO A HALF INCH OF RAINFALL THIS MORNING...WITH LIGHTER AMOUNTS
TOWARD THE I-77 CORRIDOR.
AS UPGLIDE SHUTS OFF AND MID-LEVELS DRY OUT THIS AFTERNOON...PRECIP
SHOULD COME TO AN END...ALTHOUGH THE LOW LEVELS WILL REMAIN VERY
MOIST AND THERE MAY BE PATCHES OF DRIZZLE OR LIGHT RAIN LINGERING.
POPS WILL THEREFORE BE KEPT IN THE TOKEN CHANCE RANGE IN MOST AREAS
THROUGH THE AFTERNOON. WITH PRECIP FALLING INTO A DRY AIR MASS THIS
MORNING...FOLLOWED BY ABUNDANT LOW CLOUD COVER THROUGH THE
AFTERNOON...A WEAK IN-SITU CAD EVENT MAY RESULT...AND MAX TEMPS ARE
EXPECTED TO END UP BEING RATHER CLOSE TO CLIMO...DESPITE HIGH
THICKNESS VALUES FOR THE TIME OF YEAR.
A SHORT WAVE TROUGH EJECTING FROM TEXAS/THE LOWER MISS VALLEY
TONIGHT WILL DAMPEN AS IT ENCOUNTERS THE CONFLUENT UPPER FLOW ACROSS
THE EASTERN CONUS. NEVERTHELESS...A CONSENSUS OF MODEL GUIDANCE
DEPICTS WEAK CYCLOGENESIS OCCURRING ALONG A BAROCLINIC ZONE ACROSS
GEORGIA AND THE CAROLINAS...SUPPORTING ANOTHER ROUND OF RAINFALL
LATE TONIGHT INTO EARLY MONDAY...AND WARRANTING CATEGORICAL POPS IN
ALL AREAS ONCE AGAIN. ANOTHER ROUND OF .25-.50 INCH QPF APPEARS
LIKELY IN MOST AREAS.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 300 AM SUNDAY...PESKY FRONTAL ZONE FINALLY DOES LOOK TO BE
FORCED SOUTH AND EAST OF THE CWFA MONDAY AS A CANADIAN AIRMASS
EXPANDS OVER MOST OF THE ERN CONUS. COOLER AND DRIER AIR DO START TO
FILTER IN BY MONDAY NIGHT...BUT SOME LLVL MOISTURE DOES LINGER INTO
TUE. THE SOUTHEAST REMAINS UNDER BROADLY CYCLONIC FLOW THROUGH THAT
TIME...WITH AN EMBEDDED SHORTWAVE PROGGED TO MOVE FROM THE MID
MISSISSIPPI VALLEY TO THE DELMARVA BY TUE NIGHT. A WEAK BOUNDARY
ASSOCIATED WITH THIS WAVE WILL ENHANCE COLD ADVECTION AND LLVL LIFT
MON NIGHT/EARLY TUE...IN TIME TO ENCOUNTER THE MOISTURE. THUS POPS
EXHIBIT A SECONDARY PEAK TUE MRNG. AS WINDS VEER TO NW AROUND THAT
TIME...SOME UPSLOPE ENHANCEMENT IS ALSO EXPECTED WITH POPS TAKING A
LITTLE LONGER TO TAPER OFF TUE NEAR THE TENN BORDER. TEMPS ARE
EXPECTED TO REMAIN ABOVE CLIMO THROUGH TUE MRNG. PROFILES INDICATE AN
ACCORDINGLY WARM COLUMN...AND THE MOISTURE WILL BE CONCENTRATED IN
THE LOW TO MID LEVELS. ICE NUCLEATION AND SNOW PRODUCTION ARE
UNLIKELY...SO WITH TEMPS REMAINING ABOVE FREEZING THROUGHOUT THE CWFA
MON NIGHT NO MENTION OF WINTRY PRECIP HAS BEEN MADE.
IN THE WAKE OF THE BOUNDARY DEEPER DRYING BEGINS LATER TUE AND
CONTINUES THROUGH MID-WEEK...WITH SKIES TRENDING CLEARER. MAX TEMPS
WILL RETURN TO AROUND CLIMO TUE FOLLOWED BY SIMILARLY NORMAL TEMPS
FOR WED MRNG. DESPITE THE COLD ADVECTION...NOTABLY GUSTY WINDS ARE
NOT EXPECTED WITH THE LEADING EDGE OF THE AIRMASS HAVING ALREADY
PUSHED THROUGH.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 245 AM SUNDAY...REMARKABLY STRONG SFC HIGH PRESSURE OVER THE
CENTRAL PLAINS GETS SHUNTED SWD AS NRN STREAM SHORTWAVE DIVES INTO
THE MIDWEST AND PATTERN BEGINS TO REAMPLIFY OVER THE EAST. DRY AND
SEASONABLY COOL WEATHER WILL CONTINUE FOR OUR AREA WED-THU WITH TEMPS
NEAR CLIMO. THE SFC HIGH MOVES OVER THE SOUTHEAST BY THU NIGHT
INITIATING RETURN FLOW INTO THE WRN GULF STATES AS THE CUTOFF LOW
OVER THE DESERT SOUTHWEST PICKS UP SPEED. EVENTUALLY THAT WILL TRACK
ACRS THE MIDDLE OR LOWER MISSISSIPPI VALLEY...SPINNING UP A NEW
SYSTEM. AGREEMENT BETWEEN THE 28/00Z RUNS OF THE GFS AND EC IS
GENERALLY GOOD...NOW ONLY SHOWING MINOR DIFFERENCES IN THE SFC LOW
TRACK. REGARDLESS OF THE PRECISE TRACK PRECIP CHANCES BEGIN TO
INCREASE THU NIGHT BEFORE PEAKING SATURDAY. MODELS HINT AT SOME PTYPE
CONCERNS EARLY IN THE EVENT WITH A POSSIBLE IN-SITU CAD EVENT
DEVELOPING...BUT THE BULK OF THE PRECIP SHOULD BE RAIN WITH TEMPS
TRENDING ABOVE NORMAL BEYOND FRIDAY.
&&
.AVIATION /16Z SUNDAY THROUGH THURSDAY/...
AT KCLT...-RA HAS BEEN SLOW TO MATERIALIZE OVER THE TERMINAL THIS
MORNING...REMAINING SOUTHWEST THROUGH SOUTHEAST OF THE TERMINAL THUS
FAR. STILL EXPECT PERIODS OF -RA TO DEVELOP THIS MORNING...AS THE
LOW LEVEL LIFT RESPONSIBLE FOR THE PRECIP GRADUALLY SHIFTS NORTH.
HOWEVER...WITH SOME UNCERTAINTY REGARDING THE PRECIP POTENTIAL...
THERE IS ALSO UNCERTAINTY AS TO HOW MUCH CIGS WILL LOWER LATER THIS
MORNING. THE LATEST GUIDANCE HAS COME IN A LITTLE MORE OPTIMISTIC
REGARDING THE IFR POTENTIAL...AND WE WILL CONTINUE TO HOLD OFF IFR
CIGS UNTIL THE AFTERNOON. IN FACT...I/M BECMG LESS CONFIDENT THIS
WILL EVEN WORK OUT...BUT DO NOT HAVE ENOUGH CONFIDENCE TO REMOVE THE
IFR CIGS ALTOGETHER. EXPECT CONDITIONS TO IMPROVE TO MVFR OR VFR BY
THIS EVENING. HOWEVER...CIGS WILL BEGIN TO LOWER AGAIN LATE TONIGHT
AS LIFT INCREASES AGAIN IN RESPONSE TO APPROACHING UPPER AIR
DISTURBANCE. MVFR CONDITIONS APPEAR TO BE A GOOD BET AFTER
MIDNIGHT...AND WOULD NOT BE SURPRISED TO SEE IFR DEVELOP BY THE END
OF THE PERIOD. WINDS SHOULD REMAIN LIGHT S/SW THROUGH MUCH OF THE
PERIOD.
ELSEWHERE...IFR OR EVEN LIFR CONDITIONS ARE EXPECTED TO PERSIST AT
KAND THROUGH THE MORNING...ALONG WITH OCCL MVFR VISBY IN -RA. THESE
CONDITIONS ARE EXPECTED TO DEVELOP AT KGSP/KGMU BY 15Z OR SO. THINGS
ARE A BIT MORE UNCERTAIN AT THE NC TERMINALS...AS -RA HAS BEEN SLOW
TO MATERIALIZE. IT APPEARS THAT -RA SHOULD EVENTUALLY DEVELOP AT
KAVL...BUT WHETHER THIS WILL BE ENOUGH TO BRING THE CIGS DOWN INTO
THE IFR RANGE IS UNCERTAIN. NEVERTHELESS...GUIDANCE CONTINUES TO
INSIST THAT IFR CIGS WILL DEVELOP THERE...SO A TEMPO HAS BEEN
INCLUDED DURING LATE MORNING. AT KHKY...FEEL A BIT MORE CONFIDENT IN
HOLDING OFF ON THE IFR CONDITIONS UNTIL 18Z. EXPECT CONDITIONS TO
IMPROVE TO MVFR OR VFR BY THIS EVENING. HOWEVER...CIGS WILL BEGIN TO
LOWER AGAIN LATE TONIGHT AS LIFT INCREASES AGAIN IN RESPONSE TO
APPROACHING UPPER AIR DISTURBANCE. MVFR CONDITIONS APPEAR TO BE A
GOOD BET AFTER MIDNIGHT...AND WOULD NOT BE SURPRISED TO SEE IFR
DEVELOP BY THE END OF THE PERIOD.
OUTLOOK...PERIODS OF LIGHT RAIN AND FLIGHT RESTRICTIONS MAY LINGER
MONDAY AND MONDAY NIGHT BEFORE GRADUAL IMPROVEMENT OCCURS THROUGHOUT
TUESDAY. DRY HIGH PRESSURE SHOULD RETURN BY MID-WEEK.
CONFIDENCE TABLE...
15-21Z 21-03Z 03-09Z 09-12Z
KCLT MED 69% MED 72% LOW 52% HIGH 100%
KGSP MED 69% MED 66% LOW 38% HIGH 90%
KAVL MED 63% LOW 58% LOW 49% MED 73%
KHKY HIGH 80% MED 61% LOW 38% MED 70%
KGMU HIGH 83% MED 72% LOW 44% HIGH 83%
KAND HIGH 83% LOW 47% LOW 33% HIGH 86%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...DEO
NEAR TERM...JDL/JOH
SHORT TERM...WIMBERLEY
LONG TERM...ARK/WIMBERLEY
AVIATION...JDL
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
918 AM EST SUN DEC 28 2014
.SYNOPSIS...
A COLD FRONT WILL SLOWLY CROSS OUR REGION THROUGH MONDAY...THOUGH
SOME MOISTURE WILL LINGER UNTIL TUESDAY. DRIER AND COOLER HIGH
PRESSURE WILL MOVE ACROSS THE AREA WEDNESDAY AND THURSDAY. ANOTHER
LOW PRESSURE SYSTEM THEN SHOULD BEGIN TO TAKE SHAPE AT THE END OF
THE WEEK...BRINGING PRECIPITATION BACK TO THE AREA BY FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
910 AM EST UPDATE...HAVE RAISED POPS TO 90/100 RANGE THIS MORNING
OVER THE SOUTHERN HALF OF THE CWA PER LATEST RADAR TREND. THIS IS
WELL IN LINE WITH THE LATEST HRRR WHERE THE HEAVIEST RAIN BAND WILL
MOVE ACROSS ALONG AND SOUTHEAST OF THE I-85 THIS MORNING THRU
MIDDAY. ALSO...HAVE INCLUDED AREAS OF PATCHY FOG TO ACCOUNT FOR THE
LATEST SURFACE OBS.
AS OF 645 AM...RAIN SHIELD HAS MADE VERY LITTLE NORTHWARD PROGRESS
ABOVE (ROUGHLY) I-85 THIS MORNING...AND AM BEGINNING TO WONDER IF
THE PRECIP ISN/T GOING TO JUST FIZZLE MORE OR LESS IN PLACE...AS
UPGLIDE WEAKENS...AND THE MID-LEVELS DRY OUT. WILL CONTINUE TO
FEATURE HIGH POPS (60-80) ACROSS OUR NC ZONES...BUT THESE HAVE BEEN
SCALED BACK FROM THE EARLIER FORECAST. OTHERWISE...TEMPS ARE
EXPECTED TO REMAIN MORE OR LESS STEADY THIS MORNING UNDER DENSE
CLOUD COVER.
AREA OF MODERATE RAIN IS FINALLY PUSHING ACROSS THE UPPER SAVANNAH
RIVER VALLEY THIS MORNING. IN GENERAL...THIS IS FARTHER SOUTH THAN
WHAT THE MODELS HAVE RECENTLY BEEN DEPICTING...AND THE HIGHEST QPF
FOR THIS MORNING HAS BEEN ADJUSTED TO THE UPSTATE AND NORTHEAST
GA...WHERE RAINFALL AMOUNTS THIS MORNING SHOULD RANGE FROM ONE
QUARTER TO ONE HALF INCH...WITH LOCALLY HIGHER AMOUNTS. THE PRECIP
SHIELD IS EXPECTED TO SHIFT NORTHWARD WITH TIME...AS THE BROAD BAND
OF ISENTROPIC LIFT TRANSLATES NORTHEAST TOWARD THE MID-ATLANTIC.
THEREFORE...THE MOUNTAINS AND FOOTHILLS OF WESTERN NC MAY YET SEE UP
TO A HALF INCH OF RAINFALL THIS MORNING...WITH LIGHTER AMOUNTS
TOWARD THE I-77 CORRIDOR.
AS UPGLIDE SHUTS OFF AND MID-LEVELS DRY OUT THIS AFTERNOON...PRECIP
SHOULD COME TO AN END...ALTHOUGH THE LOW LEVELS WILL REMAIN VERY
MOIST AND THERE MAY BE PATCHES OF DRIZZLE OR LIGHT RAIN LINGERING.
POPS WILL THEREFORE BE KEPT IN THE TOKEN CHANCE RANGE IN MOST AREAS
THROUGH THE AFTERNOON. WITH PRECIP FALLING INTO A DRY AIR MASS THIS
MORNING...FOLLOWED BY ABUNDANT LOW CLOUD COVER THROUGH THE
AFTERNOON...A WEAK IN-SITU CAD EVENT MAY RESULT...AND MAX TEMPS ARE
EXPECTED TO END UP BEING RATHER CLOSE TO CLIMO...DESPITE HIGH
THICKNESS VALUES FOR THE TIME OF YEAR.
A SHORT WAVE TROUGH EJECTING FROM TEXAS/THE LOWER MISS VALLEY
TONIGHT WILL DAMPEN AS IT ENCOUNTERS THE CONFLUENT UPPER FLOW ACROSS
THE EASTERN CONUS. NEVERTHELESS...A CONSENSUS OF MODEL GUIDANCE
DEPICTS WEAK CYCLOGENESIS OCCURRING ALONG A BAROCLINIC ZONE ACROSS
GEORGIA AND THE CAROLINAS...SUPPORTING ANOTHER ROUND OF RAINFALL
LATE TONIGHT INTO EARLY MONDAY...AND WARRANTING CATEGORICAL POPS IN
ALL AREAS ONCE AGAIN. ANOTHER ROUND OF .25-.50 INCH QPF APPEARS
LIKELY IN MOST AREAS.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 300 AM SUNDAY...PESKY FRONTAL ZONE FINALLY DOES LOOK TO BE
FORCED SOUTH AND EAST OF THE CWFA MONDAY AS A CANADIAN AIRMASS
EXPANDS OVER MOST OF THE ERN CONUS. COOLER AND DRIER AIR DO START TO
FILTER IN BY MONDAY NIGHT...BUT SOME LLVL MOISTURE DOES LINGER INTO
TUE. THE SOUTHEAST REMAINS UNDER BROADLY CYCLONIC FLOW THROUGH THAT
TIME...WITH AN EMBEDDED SHORTWAVE PROGGED TO MOVE FROM THE MID
MISSISSIPPI VALLEY TO THE DELMARVA BY TUE NIGHT. A WEAK BOUNDARY
ASSOCIATED WITH THIS WAVE WILL ENHANCE COLD ADVECTION AND LLVL LIFT
MON NIGHT/EARLY TUE...IN TIME TO ENCOUNTER THE MOISTURE. THUS POPS
EXHIBIT A SECONDARY PEAK TUE MRNG. AS WINDS VEER TO NW AROUND THAT
TIME...SOME UPSLOPE ENHANCEMENT IS ALSO EXPECTED WITH POPS TAKING A
LITTLE LONGER TO TAPER OFF TUE NEAR THE TENN BORDER. TEMPS ARE
EXPECTED TO REMAIN ABOVE CLIMO THROUGH TUE MRNG. PROFILES INDICATE AN
ACCORDINGLY WARM COLUMN...AND THE MOISTURE WILL BE CONCENTRATED IN
THE LOW TO MID LEVELS. ICE NUCLEATION AND SNOW PRODUCTION ARE
UNLIKELY...SO WITH TEMPS REMAINING ABOVE FREEZING THROUGHOUT THE CWFA
MON NIGHT NO MENTION OF WINTRY PRECIP HAS BEEN MADE.
IN THE WAKE OF THE BOUNDARY DEEPER DRYING BEGINS LATER TUE AND
CONTINUES THROUGH MID-WEEK...WITH SKIES TRENDING CLEARER. MAX TEMPS
WILL RETURN TO AROUND CLIMO TUE FOLLOWED BY SIMILARLY NORMAL TEMPS
FOR WED MRNG. DESPITE THE COLD ADVECTION...NOTABLY GUSTY WINDS ARE
NOT EXPECTED WITH THE LEADING EDGE OF THE AIRMASS HAVING ALREADY
PUSHED THROUGH.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 245 AM SUNDAY...REMARKABLY STRONG SFC HIGH PRESSURE OVER THE
CENTRAL PLAINS GETS SHUNTED SWD AS NRN STREAM SHORTWAVE DIVES INTO
THE MIDWEST AND PATTERN BEGINS TO REAMPLIFY OVER THE EAST. DRY AND
SEASONABLY COOL WEATHER WILL CONTINUE FOR OUR AREA WED-THU WITH TEMPS
NEAR CLIMO. THE SFC HIGH MOVES OVER THE SOUTHEAST BY THU NIGHT
INITIATING RETURN FLOW INTO THE WRN GULF STATES AS THE CUTOFF LOW
OVER THE DESERT SOUTHWEST PICKS UP SPEED. EVENTUALLY THAT WILL TRACK
ACRS THE MIDDLE OR LOWER MISSISSIPPI VALLEY...SPINNING UP A NEW
SYSTEM. AGREEMENT BETWEEN THE 28/00Z RUNS OF THE GFS AND EC IS
GENERALLY GOOD...NOW ONLY SHOWING MINOR DIFFERENCES IN THE SFC LOW
TRACK. REGARDLESS OF THE PRECISE TRACK PRECIP CHANCES BEGIN TO
INCREASE THU NIGHT BEFORE PEAKING SATURDAY. MODELS HINT AT SOME PTYPE
CONCERNS EARLY IN THE EVENT WITH A POSSIBLE IN-SITU CAD EVENT
DEVELOPING...BUT THE BULK OF THE PRECIP SHOULD BE RAIN WITH TEMPS
TRENDING ABOVE NORMAL BEYOND FRIDAY.
&&
.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
AT KCLT...-RA HAS BEEN SLOW TO MATERIALIZE OVER THE TERMINAL THIS
MORNING...REMAINING SOUTHWEST THROUGH SOUTHEAST OF THE TERMINAL THUS
FAR. STILL EXPECT PERIODS OF -RA TO DEVELOP THIS MORNING...AS THE
LOW LEVEL LIFT RESPONSIBLE FOR THE PRECIP GRADUALLY SHIFTS NORTH.
HOWEVER...WITH SOME UNCERTAINTY REGARDING THE PRECIP POTENTIAL...
THERE IS ALSO UNCERTAINTY AS TO HOW MUCH CIGS WILL LOWER LATER THIS
MORNING. THE LATEST GUIDANCE HAS COME IN A LITTLE MORE OPTIMISTIC
REGARDING THE IFR POTENTIAL...AND WE WILL CONTINUE TO HOLD OFF IFR
CIGS UNTIL THE AFTERNOON. IN FACT...I/M BECMG LESS CONFIDENT THIS
WILL EVEN WORK OUT...BUT DO NOT HAVE ENOUGH CONFIDENCE TO REMOVE THE
IFR CIGS ALTOGETHER. EXPECT CONDITIONS TO IMPROVE TO MVFR OR VFR BY
THIS EVENING. HOWEVER...CIGS WILL BEGIN TO LOWER AGAIN LATE TONIGHT
AS LIFT INCREASES AGAIN IN RESPONSE TO APPROACHING UPPER AIR
DISTURBANCE. MVFR CONDITIONS APPEAR TO BE A GOOD BET AFTER
MIDNIGHT...AND WOULD NOT BE SURPRISED TO SEE IFR DEVELOP BY THE END
OF THE PERIOD. WINDS SHOULD REMAIN LIGHT S/SW THROUGH MUCH OF THE
PERIOD.
ELSEWHERE...IFR OR EVEN LIFR CONDITIONS ARE EXPECTED TO PERSIST AT
KAND THROUGH THE MORNING...ALONG WITH OCCL MVFR VISBY IN -RA. THESE
CONDITIONS ARE EXPECTED TO DEVELOP AT KGSP/KGMU BY 15Z OR SO. THINGS
ARE A BIT MORE UNCERTAIN AT THE NC TERMINALS...AS -RA HAS BEEN SLOW
TO MATERIALIZE. IT APPEARS THAT -RA SHOULD EVENTUALLY DEVELOP AT
KAVL...BUT WHETHER THIS WILL BE ENOUGH TO BRING THE CIGS DOWN INTO
THE IFR RANGE IS UNCERTAIN. NEVERTHELESS...GUIDANCE CONTINUES TO
INSIST THAT IFR CIGS WILL DEVELOP THERE...SO A TEMPO HAS BEEN
INCLUDED DURING LATE MORNING. AT KHKY...FEEL A BIT MORE CONFIDENT IN
HOLDING OFF ON THE IFR CONDITIONS UNTIL 18Z. EXPECT CONDITIONS TO
IMPROVE TO MVFR OR VFR BY THIS EVENING. HOWEVER...CIGS WILL BEGIN TO
LOWER AGAIN LATE TONIGHT AS LIFT INCREASES AGAIN IN RESPONSE TO
APPROACHING UPPER AIR DISTURBANCE. MVFR CONDITIONS APPEAR TO BE A
GOOD BET AFTER MIDNIGHT...AND WOULD NOT BE SURPRISED TO SEE IFR
DEVELOP BY THE END OF THE PERIOD.
OUTLOOK...PERIODS OF LIGHT RAIN AND FLIGHT RESTRICTIONS MAY LINGER
MONDAY AND MONDAY NIGHT BEFORE GRADUAL IMPROVEMENT OCCURS THROUGHOUT
TUESDAY. DRY HIGH PRESSURE SHOULD RETURN BY MID-WEEK.
CONFIDENCE TABLE...
14-20Z 20-02Z 02-08Z 08-12Z
KCLT MED 79% MED 68% LOW 56% HIGH 95%
KGSP MED 64% MED 68% LOW 41% HIGH 100%
KAVL MED 64% LOW 56% LOW 51% MED 72%
KHKY MED 79% LOW 54% LOW 37% MED 70%
KGMU MED 66% MED 68% LOW 45% HIGH 90%
KAND MED 66% LOW 45% LOW 33% HIGH 90%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...DEO
NEAR TERM...JDL/JOH
SHORT TERM...WIMBERLEY
LONG TERM...ARK/WIMBERLEY
AVIATION...JDL
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1250 AM EST SUN DEC 28 2014
.SYNOPSIS...
A SERIES OF SMALL LOW PRESSURE WILL MOVE NORTHEAST ALONG A COLD
FRONT AS THE FRONT SLOWLY CROSSES OUR REGION FROM THE WEST THROUGH
MONDAY. COOLER HIGH PRESSURE WILL BUILD OVER OUR REGION IN THE MID
TO LATTER PART OF THE WEEK. ANOTHER LOW PRESSURE WILL GET ORGANIZED
OVER TEXAS AND REACH OUR AREA NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 1245 AM...PLENTY OF LIGHT RADAR RETURNS ARE STILL TO BE SEEN
ACROSS THE AREA EARLY THIS MORNING...BUT THUS FAR VERY LITTLE RAIN
HAS FALLEN AS HYDROMETEORS ARE FALLING INTO A NEAR-SURFACE AIR MASS
THAT REMAINS QUITE DRY. HOWEVER...HEAVIER PRECIPITATION IS
OVERSPREADING NORTH GEORGIA FAIRLY QUICKLY...AND THIS WILL BEGIN TO
SATURATE THE LOW LEVEL AIR MASS AS IT MOVES INTO OUR AREA OVER THE
NEXT COUPLE OF HOURS. CATEGORICAL POPS STILL APPEAR TO BE A GOOD BET
OVER THE WESTERN HALF OF THE AREA...WITH LIKELY POPS EAST.
AS OF 920 PM...LATEST RADAR IMAGES FROM KGSP INDICATED LIGHT SHOWERS
ACROSS THE LAKELANDS OF SC. UPSTREAM ACROSS CENTRAL AND NRN
GA...COVERAGE OF LIGHT RAIN WAS INCREASING...ESPECIALLY NEAR THE
AL/GA LINE. RECENT SATELLITE IMAGES INDICATED BKN TO OVC MID TO HIGH
CLOUDS ACROSS THE CWA. THE THICK CLOUD COVER HAS LIKELY CONTRIBUTED
TO KEEPING TEMPS ONE TO TWO DEGREES WARMER THAN THE CURRENT
FORECAST. I WILL UPDATE THE FORECAST TO ADJUST POPS TO RECENT RADAR
TRENDS...INCREASE SKY COVER...AND WARM HRLY TEMPS TO OBS.
AS OF 710 PM...I WILL UPDATE TO FINE TUNE CLOUDS....TEMPS...AND
POPS. WIDELY SCATTERED SHOWERS WILL LIKELY DEVELOP ACROSS THE UPPER
SAVANNAH RIVER VALLEY THIS EVENING. OTHERWISE...MOIST SOUTHWEST LLVL
WINDS WILL INCREASE ACROSS THE MTNS AND ADJACENT FOOTHILLS DURING
THE PRE DAWN HOURS. THE COMBINATION OF UPSLOPE FLOW IN INCREASING
LLVL LIFT SHOULD SUPPORT AN EXPANDING AREA OF LIGHT RAIN AND LOW
CIGS TOWARD SUNRISE.
AS OF 515 PM...LIGHT AND HIGH RADAR RETURNS WERE TRACKING ACROSS NRN
GA. THESE RETURNS HAVE NOT BEEN ASSOCIATED WITH SFC OBS OF
RAIN...EXPECTING RETURNS FROM VIRGA. HOWEVER...A LARGE PATCH OF
LIGHT RAIN WAS DRIFTING ACROSS THE AL/GA LINE...THIS AREA SHOULD
RESULT IN RAIN ACROSS THE CWA LATER TONIGHT. I WILL UPDATE TO ADJUST
POP TIMING AND ALIGN TEMP/DWPT WITH OBSERVATIONS.
AS OF 240 PM EST SATURDAY...THE LATEST SATELLITE IMAGE SHOWS A DEEP
AND MOIST WARM CONVEYOR BELT EXTENDING FROM THE GREAT LAKES REGION
DOWN TO THE WESTERN GULF...AND TO THE EASTERN PACIFIC...WITH BROAD
AREAS OF CONVECTION DEVELOPING ACROSS THE DEEP SOUTH AS OF THIS
AFTERNOON HOURS. AS AN EASTERN CONUS UPPER RIDGE AXIS PUSHES OFF THE
ATLANTIC COAST AND MOIST SWLY FLOW ALOFT SETS UP OVER THE SOUTHEAST
US...MID TO LOW LEVEL CLOUDS WILL SPREAD OVER THE PIEDMONT THROUGH
THE AFTERNOON HOURS.THE LATEST SHORT TERM MODELS CONTINUE TO
INDICATE THAT A COLD FRONT WILL SLOWLY MOVE EAST ACROSS THE
MISSISSIPPI VALLEY AND INTO THE TN VALLEY TONIGHT INTO SUN
MORNING...REACHING THE SOUTHERN APPALACHIANS BY SUN AFTERNOON. AHEAD
OF THIS FRONT...A DEEP PLUME OF GULF MOISTURE WILL BE DRAWN UP INTO
THE REGION AS A WAVE OF LOW OVER THE WESTERN GULF LIFTS NE ACROSS
AL/MI TONIGHT. THEREFORE...POPS QUICKLY RAMP UP FROM WEST TO EAST
INTO THE CATEGORICAL RANGE OVER THE WESTERN MTNS ZONES AND NE
GA...WITH LIKELY RANGE OVER THE REST OF THE WESTERN HALF OF THE CWA.
THE BEST RAINFALL RATES WILL OCCUR BETWEEN 12Z-18Z SUN WHEN THE
SURFACE WAVE OF LOW LIFTS NE ACROSS THE CWA AND A SERIES OF UPPER
DISTURBANCES RIPPLES ACROSS THE MTNS ZONES IN SWLY FLOW ALOFT.
ALSO...HAVE MENTIONED A CHANCE OF THUNDER ACROSS MUCH OF THE REGION
EARLY SUN AFTERNOON DUE TO THE PRESENCE OF 100-200J/KG MUCAPE PER
LATEST NAM/GFS/ECMWF. POPS RAMP DOWN TO THE LIKELY RANGE OVER THE
MTN ZONES AND SOLD CHANCE RANGE OVER THE SOUTHERN TIER OF THE REGION
18Z THRU 00Z MON AS THE UPPER FORCING AND THE SURFACE WAVE OF LOW
MOVES OFF TO THE NE. WITH MODELS TRENDING A BIT WETTER FOR THE
UPCOMING EVENT...HAVE GONE WITH THE HPC QPF GUIDANCE RESULTING IN
0.75-1.0" OVER THE WESTERN NC MTNS AND NE GA... WITH AROUND
0.25-0.5" ELSEWHERE THRU SUN EVENING.
WITH CONSIDERABLE CLOUD COVER AND WAA SOUTHERLY FLOW...OVERNIGHT
TEMPS WILL STAY 7-10 DEGREES ABOVE NORMAL. WITH ONGOING
PRECIP...AFTERNOON HIGHS ON SUN WILL BE AROUND 3-5 DEGREES COOLER
THAN TODAY.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY/...
AS OF 200 PM SATURDAY...THE MODELS SUGGEST THAT WE WILL BE IN A LULL
OF SORTS AT THE START OF THE SHORT RANGE PERIOD SUNDAY EVENING...AS
WE WILL BE IN A MINIMUM OF FORCING. THAT CHANGES QUICKLY BY LATE
EVENING AS THE RIGHT ENTRANCE REGION OF THE UPPER JET TRANSLATES
OVERHEAD BETWEEN ROUGHLY 03Z AND 09Z...AND THE MAIN SHORT WAVE AXIS
MOVES THROUGH IN THE 06Z TO 12Z MONDAY TIME FRAME. ALTHO THE WAVE
SHEARS AND DEAMPLIFIES AS IT CROSSES THE REGION...THE FORCING SHOULD
STILL BE SUFFICIENT TO INCREASE PRECIP PRODUCTION...COMBINED WITH
IMPROVED MOIST ISENTROPIC LIFT. SO...PRECIP CHANCES RAMP BACK UP TO
CATEGORICAL MAINLY OVER THE AREA ALONG AND N/W OF I-85...AND LIKELY
TO THE S...BY 06Z OR SO. THE MAIN FORCING SHOULD SHIFT E OF THE AREA
MONDAY MORNING. THE HIGHEST PRECIP PROBABILITY WILL BE OVER THE WRN
NC PIEDMONT ON MONDAY MORNING. POP WAS LIMITED TO LIKELY OUT OF
UNCERTAINTY WITH TIMING THE DEPARTURE OF THE FORCING...BUT COULD
EASILY HAVE TO BE KEPT CATEGORICAL BEYOND 12Z MONDAY WITH THE
SLIGHTEST DELAY. THE REST OF MONDAY WILL HAVE A SLOW RAMP DOWN
THROUGH THE CHANCE RANGE AS FORCING GRADUALLY WEAKENS BEHIND THE
SURFACE FRONT THAT CROSSES FIRST THING IN THE DAY. FOR MONDAY NIGHT
AND TUESDAY...THERE IS UNCERTAINTY REGARDING THE EXTENT/CHANCE OF
PRECIP. THE LOW LEVEL FLOW COMES AROUND TO SOMETHING NW MONDAY NIGHT
AND TUESDAY WHICH SHOULD FORCE SOME SHOWER ACTIVITY NEAR THE TN
BORDER. THE PASSAGE OF ANOTHER SHORT WAVE COMBINED WITH SOME LOW
LEVEL FRONTOGENESIS APPEARS TO BE RESPONSIBLE FOR THE REDEVELOPMENT
OF PRECIP ON TUESDAY OFF TO OUR N...WHICH SOME OF THE GUIDANCE
BLEEDS DOWN INTO NC. PREFER TO KEEP THE BETTER CHANCES IN THE
UPSLOPE AREAS OF THE NRN MTNS AND TO KEEP THE AREA E OF THE BLUE
RIDGE DRY FOR THE TIME BEING. TEMPS SHOULD DROP BACK DOWN TO NEAR
NORMAL ON TUESDAY.
ON SUNDAY THE FAIRLY BROAD FRONTAL ZONE WILL
EXTEND FROM QUEBEC SWWD TO THE WRN GULF COAST...BISECTING THE TENN
VALLEY JUST TO OUR WEST. AT LEAST ONE WEAK WAVE IS PROGGED TO RIDE
UP THE FRONT DURING THE DAY AS A RESULT OF CYCLONIC UPPER FLOW OVER
THE BOUNDARY CONTAINING EMBEDDED WEAK VORTICES. THOUGH SUCH A WAVE
WOULD LIKELY PROVIDE LOCAL ENHANCEMENT TO LLVL WARM/MOIST ADVECTION
AHEAD OF THE FRONT...THE EXISTENCE OF ONE IS IN QUESTION GIVEN THE
POOR AGREEMENT AND CONSISTENCY FROM GUIDANCE ON HOW THIS OCCURS.
OVERALL THE FORCING SUNDAY IS JUST NOT ALL THAT IMPRESSIVE. LITTLE
TO NO INSTABILITY IS PROGGED OVER THE CWFA AND THOUGH A GOOD SLUG OF
MOISTURE TRANSPORT IS PRESENT ON NAM/GFS PROGS THE LLVL LIFT IS
LIMITED. AT ANY RATE...THRU SUNDAY THE FRONT REMAINS NEARLY
STATIONARY ACRS THE SOUTHEAST...THE PARENT LOW CONTINUING TO
PROGRESS EWD WITH THE ACTIVE NRN STREAM WHILE THE BROAD SRN STREAM
TROUGH IS HELD OFF BY THE BERMUDA HIGH. IT APPEARS THE FRONT WILL
NOT ACTUALLY ENTER THE AREA UNTIL MONDAY MRNG...WITH A DISTINCT
500MB SHORTWAVE ACCOMPANYING IT AS WELL AS UPPER DIVERGENCE ASSOC
WITH RR QUAD OF A JET STREAK.
TWO PEAKS OF PRECIP ACTIVITY ARE SUGGESTED WHEN THE TOTAL FORCING IS
MAXIMIZED...SUNDAY MRNG AND THEN EARLY MON MRNG. HOWEVER IT IS
DIFFICULT TO PICK OUT A POINT BETWEEN WHERE A LULL SHOULD BE
BETWEEN...WITH THE OVERALL PATTERN REMAINING FAVORABLE FOR AT LEAST
LIGHT PRECIP. WILL CONTINUE TO ADVERTISE LIKELY POPS MOST OF THE AREA
THROUGHOUT SUNDAY...BUT CONCENTRATING MORE QPF CLOSE TO THE
AFOREMENTIONED PEAKS. DESPITE CLOUDS AND RAIN...IN THE WARM AIRMASS
TEMPS SHOULD TOP OUT 5-9 DEGREES ABOVE NORMAL SUN AFTN...WITH MINS
MON MRNG BEING EVEN MORE ABOVE NORMAL...UPPER 40S AND LOWER 50S. MAX
TEMPS MONDAY WILL BE SLIGHTLY WARMER THAN SUNDAY OVER THE PIEDMONT
WITH THE FRONT NOT YET HAVING AN IMPACT.
PROGRESSION OF THE UPPER PATTERN IS STILL PRETTY SLOW THRU MON
NIGHT...WITH THE CWFA NEAR THE INFLECTION POINT BETWEEN THE PLAINS
TROUGH AND THE ATLANTIC RIDGE. POPS DECLINE ONLY GRADUALLY THRU THE
END OF THE PERIOD WITH MOST OF THE GUIDANCE INDICATING SOME QPF
CONTINUING ON THE BACK SIDE OF ANOTHER FRONTAL WAVE DEVELOPING NEAR
THE GA/SC COAST. COLDER AIR WILL BEGIN TO RETURN TO ALL AREAS ON THE
ENSUING NLY FLOW MON NIGHT...THOUGH MIN TEMPS WILL STILL BE AROUND 10
DEGREES ABOVE CLIMO.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 215 PM SATURDAY...THE MEDIUM RANGE WILL START OUT WITH SPLIT
UPPER LVL FLOW...WITH A LARGE POLAR VORTEX SPINNING OVR HUDSON
BAY...AND A CUTOFF LOW INVOF CALIFORNIA. THE MODEL GUIDANCE HAS BEEN
SLOWLY CONVERGING ON THE TIMING OF THE CUTOFF LOW BEING EJECT ACRS
INTO THE SOUTHERN STREAM AROUND FRIDAY. HOWEVER...THERE IS STILL
SOME DISAGREEMENT ON THAT...WITH THE GFS CONSISTENTLY
FASTER/EARLIER...AND THE ECMWF SLOWER/DEEPER. THE LATEST WPC
PREFERENCE IS WITH THE ENSEMBLE MEAN...SLOWER THAN THE GFS...AND NOT
AS DEEP WITH THE RESULTED PROGRESSIVE SHORTWAVE TROF AS THE ECMWF.
AT THE SFC...A BROAD AREA OF CANADIAN HIGH PRES WILL ENCOMPASS ABOUT
3/4TH OF THE CONUS ON WEDNESDAY...GRADUALLY MODIFYING AND DRIFTING
EAST WITH THE CENTER CROSSING THE CWFA EARLY FRIDAY. DRY WEATHER AND
SLIGHTLY BELOW NORMAL TEMPS ARE EXPECTED WEDNESDAY THRU THURSDAY
NIGHT. AS THE EJECTING UPPER TROF FINALLY ENTERS THE SOUTHERN
PLAINS...A LOW PRES SYSTEM SHUD BEGIN TO ORGANIZE...TAPPING INTO
COPIOUS GULF MOISTURE. POPS WILL THEN RAMP UP BY NEXT WEEKEND. OF
COURSE...EXACT TIMING IS STILL THE MAIN QUESTION. THE 12Z GFS AND
ECMWF BOTH SHOW POSSIBLE WINTRY MIX PRECIP TYPE CONCERNS AT ONSET
FRIDAY MORNING...BUT THEN TURNING OVER TO ALL RAIN...AS STRONG SWLY
WAA SHUD DOMINATE ANY LINGERING IN SITU COLD AIR DAMMING.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AT KCLT...THE OVERNIGHT/EARLY MORNING HOURS WILL SEE LOWERING
CIGS...WITH LOW VFR CONDITIONS EXPECTED BY DAYBREAK...AND INCREASING
CHANCES FOR -RA. ONCE THE -RA OVERSPREADS THE AREA LATER THIS
MORNING...SATURATION OF THE LOW LEVEL AIR MASS SHOULD RESULT IN MVFR
CIGS DEVELOPING BY MID-MORNING...WITH IFR EXPECTED BY EARLY
AFTERNOON. CIGS WILL THEN BE SLOW TO IMPROVE...BUT WE MAY SEE BRIEF
IMPROVEMENT TO MVFR OR EVEN VFR BY SUNDAY EVENING...JUST IN TIME FOR
ANOTHER ROUND OF -RA TO OVERSPREAD THE AREA. WINDS WILL GENERALLY
REMAIN LIGHT OUT OF THE SW...ALTHOUGH THEY MAY GO LIGHT/VRBL OR CALM
AFTER THE PRECIP SETS IN LATER THIS MORNING.
ELSEWHERE...-RA WILL GRADUALLY OVERSPREAD THE TERMINALS OVER THE
NEXT 2-4 HOURS. CIGS SHOULD ALSO LOWER DURING THAT WINDOW...WITH
MVFR CONDITIONS LIKELY AT MOST TERMINALS BY DAYBREAK. PERIODS OF
REDUCED VISBY WILL ALSO BECOME MORE LIKELY BY THAT TIME. IFR
CONDITIONS WILL BE MOST LIKELY AT KAND AND KAVL PRIOR TO 12Z...AND
TEMPOS HAVE BEEN INCLUDED TO ACCOUNT FOR THIS. OTHERWISE...CIGS
SHOULD REDUCE TO IFR OR EVEN LOWER BY MID-MORNING AT MOST TERMINALS.
IMPROVEMENT WILL BE SLOW...BUT WE MAY SEE BRIEF MVFR OR EVEN VFR
CONDITIONS BY SUNDAY EVENING...JUST IN TIME FOR ANOTHER ROUND OF -RA
TO OVERSPREAD THE AREA.
OUTLOOK...PERIODS OF RAIN AND FLIGHT RESTRICTIONS MAY LINGER FROM
LATE SUNDAY NIGHT THROUGH MONDAY NIGHT BEFORE GRADUAL IMPROVEMENT
OCCURS THROUGHOUT TUESDAY. DRY HIGH PRESSURE SHOULD RETURN BY MID-
WEEK.
CONFIDENCE TABLE...
06-12Z 12-18Z 18-24Z 00-06Z
KCLT HIGH 100% HIGH 94% HIGH 87% HIGH 80%
KGSP HIGH 94% LOW 52% LOW 59% LOW 56%
KAVL MED 66% LOW 52% LOW 55% HIGH 83%
KHKY HIGH 100% MED 68% LOW 50% LOW 48%
KGMU HIGH 96% LOW 59% MED 60% MED 60%
KAND HIGH 85% HIGH 93% LOW 52% MED 70%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...DEO
NEAR TERM...JDL/NED
SHORT TERM...PM
LONG TERM...ARK
AVIATION...JDL
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1125 PM CST SAT DEC 27 2014
.AVIATION 06Z DISCUSSION...
INVERTED SFC TROUGH TO CONTINUE PUSHING SLOWLY EASTWARD ACROSS THE
MID STATE TONIGHT. PLENTY OF MOISTURE...BOTH IN ADVANCE AND BEHIND
THE TROUGH...WILL ALLOW FOR A CONTINUATION OF RAINFALL THROUGH THE
TAF PD. AS A RESULT...LOW CIGS AND VSBYS WILL PERSIST. RAINFALL
COVERAGE WILL LET UP AFT 18Z. BY 00Z SHOULD JUST BE LOOKING AT
VCSH ACROSS THE BNA AND CKV AREAS. CIGS WILL REMAIN LOW THROUGH
THE TAF PD.
&&
.PREV DISCUSSION... /ISSUED 732 PM CST SAT DEC 27 2014/
DISCUSSION...
INVERTED TROUGH AXIS APPROACHING WESTERN MIDDLE TN AT THIS TIME. A
MARKED DECREASE IN COVERAGE IS NOTED ACROSS WESTERN PORTIONS OF
THE CWA. HOWEVER...LATEST RADAR TRENDS AND THE HRRR INFORMATION
BOTH SUGGEST THAT PRECIP COVERAGE WILL FILL IN ALONG AND WEST OF
THE ADVANCING TROUGH. A CLOSER LOOK DOES REVEAL SOME APPRECIABLE
SEPARATION IN REGARD TO THE 850 MB AND SFC FRONT.
FURTHERMORE...THE GREATER LOW LEVEL FORCING RESIDES ALONG THE 850
MB FRONT WHERE THE ANGULAR CONVERGENCE IS GREATER.
FOR THE FCST...DESPITE THE CURRENT DECREASE IN COVERAGE...WILL
CONTINUE WITH THE CATEGORICAL POPS AS WAS MENTIONED EARLIER...THE
COVERAGE SHOULD FILL BACK IN.
NO CHANGES FOR NOW TO THE FCST.
PREV DISCUSSION... /ISSUED 510 PM CST SAT DEC 27 2014/
AVIATION 00Z DISCUSSION...
INVERTED SFC TROUGH TO PUSH SLOWLY EASTWARD ACROSS THE MID STATE
TONIGHT. PLENTY OF MOISTURE...BOTH IN ADVANCE AND BEHIND THE
TROUGH...WILL ALLOW FOR A CONTINUATION OF RAINFALL THROUGH THE TAF
PD. AS A RESULT...LOW CIGS AND VSBYS WILL PERSIST. RAINFALL
COVERAGE WILL LET UP SOME AS WE APPROACH THE END OF THE TAF
PD...BETWEEN 18Z AND 00Z.
PREV DISCUSSION... /ISSUED 304 PM CST SAT DEC 27 2014/
DISCUSSION...
LOCAL AND REGIONAL RADAR IMAGERY SHOW WIDESPREAD RAIN SHOWER
COVERAGE STRETCHING FROM MIDDLE TENNESSEE BACK TO THE LOUISIANA-
TEXAS BORDER...AND SOUTH TO THE GULF COAST. THESE SHOWERS ARE
ASSOCIATED WITH AN AREA OF LOW LEVEL CONVERGENCE...WHICH AS IT
APPROACHES THE MID-STATE WILL BECOME ALIGNED WITH AN UPPER LEVEL
JET STREAK. LIGHTNING COVERAGE HAS DIMINISHED...AND WITH FORECAST
MODELS SHOWING LAPS RATES BELOW 6 DEGREES HAVE REMOVED IT FROM
THE FORECAST. AFTER THE STEADY RAIN MOVES THROUGH TONIGHT...A
BRIEF PERIOD OF LITTLE IF ANY SHOWER ACTIVITY IS EXPECTED FOR
SUNDAY...MAINLY IN THE AFTERNOON HOURS AND ESPECIALLY ACROSS THE
NORTHWEST COUNTIES.
FOR SUNDAY NIGHT SHOWER ACTIVITY IS EXPECTED TO RETURN...WITH
ANOTHER SHORTWAVE TRACKING FROM THE LOUISIANA- TEXAS BORDER TO
NORTH CAROLINA BY MONDAY MORNING. THE BETTER MOISTURE AXIS AND
UPPER LEVEL SUPPORT...WHILE MINIMAL...FAVOR THE SOUTHERN AND
EASTERN AREAS. THE NORTHWEST COUNTIES WILL JUST HAVE SLIGHT TO LOW
CHANCE POPS FOR SUNDAY NIGHT...AND MAY EVEN BE COMPLETELY DRY.
THIS SOUTHERLY TRACK WILL BRING STORM TOTAL RAINFALL AMOUNTS FOR
AREAS MAINLY ALONG AND SOUTH OF I-40 TO AROUND AN INCH TO AN INCH
AND A HALF BY MONDAY MORNING.
A SECONDARY FRONT WITH MUCH MORE NOTABLE COLD AIR ADVECTION PUSHES
THROUGH THE MID-STATE WEDNESDAY...AND LINGERS THROUGH THURSDAY.
THE LONG-RANGE MODELS INDICATE A MUCH STRONGER SHORTWAVE
DEVELOPING OVER TEXAS BY SATURDAY MORNING...AND TRACKING THROUGH
THE OHIO RIVER VALLEY BY SUNDAY EVENING. THE WARM FRONT SURGE OUT
AHEAD OF IT ARRIVES THURSDAY NIGHT...SO WITH THE AFOREMENTIONED
COLD AIR IN PLACE SOME MIXED PRECIPITATION IS POSSIBLE...EVEN A
PERIOD OF SNOW DURING THE OVERNIGHT HOURS...MAINLY OVER THE
SOUTHWESTERN COUNTIES. BY FRIDAY MORNING...TEMPERATURES WARM ABOVE
FREEZING AND STEADY RAIN IS EXPECTED TO LINGER THROUGH FRIDAY
NIGHT AND POSSIBLY INTO SATURDAY PER THE ECMWF.
&&
.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE 45 45 36 49 / 100 80 70 10
CLARKSVILLE 41 42 33 47 / 100 60 20 10
CROSSVILLE 47 51 40 49 / 100 100 90 20
COLUMBIA 46 47 37 51 / 100 80 70 10
LAWRENCEBURG 47 49 37 51 / 100 80 90 10
WAVERLY 42 43 33 48 / 100 80 50 10
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
21
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
907 PM CST MON DEC 29 2014
.UPDATE...
WINDS BEGAN BACKING AT SUNSET AND WILL CONTINUE OVERNIGHT AS
COLDER AIR OVER OKLAHOMA/KANSAS SPREADS SOUTH. HAVE UPDATED TO
OVERNIGHT SKY GRIDS FOR MOSTLY CLEAR CONDITIONS OVER THE
NORTHWEST THIRD THROUGH MIDNIGHT. LOW CLOUDS OVER EAST TEXAS HAVE
ALREADY REACHED A PARIS-GREENVILLE-FAIRFILED LINE AND WILL
CONTINUE TO MOVE WESTWARD OVERNIGHT. LOW TEMPERATURES TONIGHT
SEEM REASONABLE CONSIDERING THE INCREASING CLOUD COVER AND COLD
AIR ADVECTION.
AS FOR THE WINTRY PRECIPITATION EVENT TUESDAY NIGHT THROUGH
THURSDAY MORNING...TONIGHT/S NAM RUN DOES NOT ADD OR SUBTRACT ANY
CONFIDENCE RELATED TO THE POTENTIAL FOR SOME FORM OF A WINTRY MIX
TO DEVELOP DURING THE TIME PERIOD. ALTHOUGH THE MODELS ARE COLD
ENOUGH FOR FREEZING RAIN OR SLEET TUESDAY NIGHT THROUGH WEDNESDAY
NIGHT...MODEL QPF REMAINS LOW AND JUST A FEW HUNDREDTHS OF AN INCH
UNTIL NEW YEARS DAY WHEN QPF POTENTIAL INCREASES DUE INCREASED
WARM AIR ADVECTION ALOFT AND SYNOPTIC LIFT FROM AN APPROACHING
SHORTWAVE TO THE WEST. THUS...WE WILL ALLOW THE FORECAST FOR
TUESDAY AND BEYOND TO REMAIN AS IS AND ISSUE AN UPDATED ZONE
PACKAGE TO INCLUDE THE SKY COVER CHANGES FOR THE REST OF THE
EVENING THROUGH ABOUT 2 AM IN THE MORNING. 75
&&
.AVIATION...
/ISSUED 548 PM CST MON DEC 29 2014/
MAIN CONCERN IN TAF FORECAST IS THE POTENTIAL FOR LOW CIGS
TONIGHT. RESIDUAL FOG BANK TO THE EAST OF TAF SITES HAS LIFTED TO
A CLOUD BANK OF IFR CIGS. AS A SURFACE LOW DROPS INTO CENTRAL
TEXAS WINDS WILL BACK FROM THE SOUTHEAST TO THE NORTHEAST THIS
EVENING. THIS WILL BRING THESE CLOUDS AND HIGHER LOW LEVEL
MOISTURE INTO THE TAF SITES. HRRR BRINGS IFR INTO METROPLEX AFTER
1Z...WHILE THE RUC/NAM HOLD OFF UNTIL AFTER MIDNIGHT. THE GFS HAS
NO CIGS AND DID NOT RECOGNIZE THE EXTENT OF LOW LEVEL MOISTURE
AVAILABLE. WILL SIDE WITH NAM/RUC TIMING.
OTHERWISE ARCTIC FRONT WILL MOVE THROUGH TONIGHT...BUT FRONTAL
PASSAGE WILL BE AMBIGUOUS AS THE ONLY NOTICEABLE CHANGE WILL BE
RISING PRESSURE AND A GRADUAL TURN OF THE WINDS TO THE NORTH
BY DAYBREAK. WILL BRING LOW CIGS UP GRADUALLY TOMORROW...WITH MVFR
BY MID-MORNING AND VFR BY MID-AFTERNOON FOR METROPLEX SITES. AT
WACO CIGS WILL LIKELY HANG IN AT MVFR THROUGH THE AFTERNOON.
TR.92
&&
.PREV DISCUSSION... /ISSUED 305 PM CST MON DEC 29 2014/
06Z GUIDANCE CAME IN WETTER THAN PREVIOUS...PUTTING US IN THE MIND
FRAME TO INCREASE THE ICE POTENTIAL IN THE WEST...BUT THE 12Z RUN
CAME BACK DRIER AGAIN AND THEREFORE THIS FORECAST HAS LOW POPS IN
THE WEST THROUGH WEDNESDAY...AND LITTLE WINTER WEATHER
ACCUMULATIONS. ALTHOUGH PRECIPITATION TYPE IS STILL A BIT
UNCERTAIN...WE THINK QPF WILL REMAIN QUITE LOW BECAUSE THERE IS
NO SOURCE OF LARGE SCALE LIFT PROGGED UNTIL THURSDAY MORNING WHEN
A STRONG SHORT WAVE MOVES ACROSS THE AREA.
BY EARLY WEDNESDAY MORNING THE LOW LEVELS ARE FAIRLY SATURATED IN
OUR WESTERN COUNTIES. DRIZZLE DROPS ARE EXPECTED TO FORM AND FALL
THROUGH A SHALLOW BELOW-FREEZING LAYER AT AND JUST ABOVE THE SURFACE.
WE HAVE GONE WITH A DRIZZLE/FREEZING RAIN MIX BECAUSE THERE ARE
PERIODS WHERE THE DROPLETS CAN BE BIG ENOUGH TO BE CALLED FREEZING
RAIN. THERE MAY BE SOME SLEET MIXED IN AS WELL AS THE SLOWLY
FALLING SMALLER DROPS MAY HAVE TIME TO FREEZE IN THE AIR JUST ABOVE
THE SURFACE. WE WENT WITH THE TWO MOST LIKELY PRECIP TYPES IN THE
GRIDS BUT THIS MAY CHANGE AS LATER RUNS CHANGE TEMPERATURE
PROFILES.
TEMPERATURES WILL RISE ABOVE FREEZING WEDNESDAY AFTERNOON...BUT
FALL BELOW FREEZING AGAIN INTO THURSDAY MORNING ACROSS MOST OF THE
NORTHWESTERN HALF OF NORTH/CENTRAL TEXAS. BEFORE SUNRISE...THE LIFT
ASSOCIATED WITH A SHORT WAVE DISTURBANCE ROTATING AROUND THE UPPER
LOW WILL INCREASE MOISTURE ABOVE THE INVERSION...WARM THE AIR
COLUMN ALOFT...AND PRODUCE ISENTROPIC LIFT INITIALLY IN OUR
SOUTHWESTERN COUNTIES. PRECIP SHOULD FALL AS FREEZING RAIN
INITIALLY IN BELOW FREEZING AREAS AND THEN TRANSITION TO RAIN
ACROSS THE CWA BY EARLY AFTERNOON. COUNTIES SOUTHEAST OF A LINE
FROM TEMPLE TO CORSICANA TO BONHAM WILL LIKELY BE ABOVE FREEZING
BEFORE THE PRECIP STARTS.
IN NORTHWEST COUNTIES WHERE COLD AIR IS EXPECTED TO BE
DEEPER...PRECIP TYPE MAY BEGIN AS SLEET AND THEN TRANSITION TO
FREEZING RAIN...THEN RAIN. CHANGEOVER TIMING WILL HINGE ON INITIAL
TEMPERATURES...TIMING OF THE SHORT WAVE...AND WARMING OF THE LOW
LEVELS DUE TO RAIN FALLING FROM THE WARM NOSE THAT DEVELOPS THURSDAY.
A SECOND ROUND OF PRECIPITATION...ALL LIQUID...WILL BEGIN
OVERNIGHT INTO FRIDAY MORNING. SHOWERS WITH SOME ISOLATED EMBEDDED
THUNDER WILL CONTINUE UNTIL SATURDAY MORNING AS THE SYSTEM PUSHES
EAST.
AS RIDGING DEVELOPS OVER THE AREA...NORTH/CENTRAL TX SHOULD REMAIN
COOL AND DRY THROUGH EARLY NEXT WEEK. 84
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 33 42 27 35 32 / 5 5 5 10 20
WACO, TX 34 45 29 38 32 / 5 5 5 10 30
PARIS, TX 30 43 25 40 31 / 5 5 5 10 10
DENTON, TX 30 41 23 34 29 / 5 5 5 10 20
MCKINNEY, TX 29 42 24 35 31 / 5 5 5 10 20
DALLAS, TX 34 43 28 35 33 / 5 5 5 10 20
TERRELL, TX 32 44 28 37 33 / 5 5 5 10 20
CORSICANA, TX 36 45 29 39 34 / 5 5 5 10 30
TEMPLE, TX 35 46 29 38 32 / 5 5 5 10 30
MINERAL WELLS, TX 29 38 22 33 28 / 5 10 10 20 20
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/75
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
548 PM CST MON DEC 29 2014
.AVIATION...
MAIN CONCERN IN TAF FORECAST IS THE POTENTIAL FOR LOW CIGS
TONIGHT. RESIDUAL FOG BANK TO THE EAST OF TAF SITES HAS LIFTED TO
A CLOUD BANK OF IFR CIGS. AS A SURFACE LOW DROPS INTO CENTRAL
TEXAS WINDS WILL BACK FROM THE SOUTHEAST TO THE NORTHEAST THIS
EVENING. THIS WILL BRING THESE CLOUDS AND HIGHER LOW LEVEL
MOISTURE INTO THE TAF SITES. HRRR BRINGS IFR INTO METROPLEX AFTER
1Z...WHILE THE RUC/NAM HOLD OFF UNTIL AFTER MIDNIGHT. THE GFS HAS
NO CIGS AND DID NOT RECOGNIZE THE EXTENT OF LOW LEVEL MOISTURE
AVAILABLE. WILL SIDE WITH NAM/RUC TIMING.
OTHERWISE ARCTIC FRONT WILL MOVE THROUGH TONIGHT...BUT FRONTAL
PASSAGE WILL BE AMBIGUOUS AS THE ONLY NOTICEABLE CHANGE WILL BE
RISING PRESSURE AND A GRADUAL TURN OF THE WINDS TO THE NORTH
BY DAYBREAK. WILL BRING LOW CIGS UP GRADUALLY TOMORROW...WITH MVFR
BY MID-MORNING AND VFR BY MID-AFTERNOON FOR METROPLEX SITES. AT
WACO CIGS WILL LIKELY HANG IN AT MVFR THROUGH THE AFTERNOON.
TR.92
&&
.PREV DISCUSSION... /ISSUED 305 PM CST MON DEC 29 2014/
06Z GUIDANCE CAME IN WETTER THAN PREVIOUS...PUTTING US IN THE MIND
FRAME TO INCREASE THE ICE POTENTIAL IN THE WEST...BUT THE 12Z RUN
CAME BACK DRIER AGAIN AND THEREFORE THIS FORECAST HAS LOW POPS IN
THE WEST THROUGH WEDNESDAY...AND LITTLE WINTER WEATHER
ACCUMULATIONS. ALTHOUGH PRECIPITATION TYPE IS STILL A BIT
UNCERTAIN...WE THINK QPF WILL REMAIN QUITE LOW BECAUSE THERE IS
NO SOURCE OF LARGE SCALE LIFT PROGGED UNTIL THURSDAY MORNING WHEN
A STRONG SHORT WAVE MOVES ACROSS THE AREA.
BY EARLY WEDNESDAY MORNING THE LOW LEVELS ARE FAIRLY SATURATED IN
OUR WESTERN COUNTIES. DRIZZLE DROPS ARE EXPECTED TO FORM AND FALL
THROUGH A SHALLOW BELOW-FREEZING LAYER AT AND JUST ABOVE THE SURFACE.
WE HAVE GONE WITH A DRIZZLE/FREEZING RAIN MIX BECAUSE THERE ARE
PERIODS WHERE THE DROPLETS CAN BE BIG ENOUGH TO BE CALLED FREEZING
RAIN. THERE MAY BE SOME SLEET MIXED IN AS WELL AS THE SLOWLY
FALLING SMALLER DROPS MAY HAVE TIME TO FREEZE IN THE AIR JUST ABOVE
THE SURFACE. WE WENT WITH THE TWO MOST LIKELY PRECIP TYPES IN THE
GRIDS BUT THIS MAY CHANGE AS LATER RUNS CHANGE TEMPERATURE
PROFILES.
TEMPERATURES WILL RISE ABOVE FREEZING WEDNESDAY AFTERNOON...BUT
FALL BELOW FREEZING AGAIN INTO THURSDAY MORNING ACROSS MOST OF THE
NORTHWESTERN HALF OF NORTH/CENTRAL TEXAS. BEFORE SUNRISE...THE LIFT
ASSOCIATED WITH A SHORT WAVE DISTURBANCE ROTATING AROUND THE UPPER
LOW WILL INCREASE MOISTURE ABOVE THE INVERSION...WARM THE AIR
COLUMN ALOFT...AND PRODUCE ISENTROPIC LIFT INITIALLY IN OUR
SOUTHWESTERN COUNTIES. PRECIP SHOULD FALL AS FREEZING RAIN
INITIALLY IN BELOW FREEZING AREAS AND THEN TRANSITION TO RAIN
ACROSS THE CWA BY EARLY AFTERNOON. COUNTIES SOUTHEAST OF A LINE
FROM TEMPLE TO CORSICANA TO BONHAM WILL LIKELY BE ABOVE FREEZING
BEFORE THE PRECIP STARTS.
IN NORTHWEST COUNTIES WHERE COLD AIR IS EXPECTED TO BE
DEEPER...PRECIP TYPE MAY BEGIN AS SLEET AND THEN TRANSITION TO
FREEZING RAIN...THEN RAIN. CHANGEOVER TIMING WILL HINGE ON INITIAL
TEMPERATURES...TIMING OF THE SHORT WAVE...AND WARMING OF THE LOW
LEVELS DUE TO RAIN FALLING FROM THE WARM NOSE THAT DEVELOPS THURSDAY.
A SECOND ROUND OF PRECIPITATION...ALL LIQUID...WILL BEGIN
OVERNIGHT INTO FRIDAY MORNING. SHOWERS WITH SOME ISOLATED EMBEDDED
THUNDER WILL CONTINUE UNTIL SATURDAY MORNING AS THE SYSTEM PUSHES
EAST.
AS RIDGING DEVELOPS OVER THE AREA...NORTH/CENTRAL TX SHOULD REMAIN
COOL AND DRY THROUGH EARLY NEXT WEEK. 84
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 33 42 27 35 32 / 5 5 5 10 20
WACO, TX 34 45 29 38 32 / 5 5 5 10 30
PARIS, TX 30 43 25 40 31 / 5 5 5 10 10
DENTON, TX 30 41 23 34 29 / 5 5 5 10 20
MCKINNEY, TX 29 42 24 35 31 / 5 5 5 10 20
DALLAS, TX 34 43 28 35 33 / 5 5 5 10 20
TERRELL, TX 32 44 28 37 33 / 5 5 5 10 20
CORSICANA, TX 36 45 29 39 34 / 5 5 5 10 30
TEMPLE, TX 35 46 29 38 32 / 5 5 5 10 30
MINERAL WELLS, TX 29 38 22 33 28 / 5 10 10 20 20
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
340 PM CST SUN DEC 28 2014
.DISCUSSION...
TODAY/S PERSISTENT SHOWER ACTIVITY HAS NOW STARTED TO CLEAR THE
WESTERNMOST COUNTIES AS OF 3 PM /GENERALLY AREAS WEST OF THE
BRAZOS RIVER/. THIS ACTIVITY WILL CONTINUE TO PRODUCE LIGHT
RAINFALL TOTALS INTO THE EVENING HOURS AS IT TRANSLATES EAST AHEAD
OF A COMPACT SHORTWAVE TROUGH MOVING ACROSS THE STATE. THE EDGE OF
THE CLOUD DECK ASSOCIATED WITH THE RAIN LAGS BEHIND THE END OF THE
RAINFALL AND IS NOT ANTICIPATED TO REACH SOUTHEAST TEXAS UNTIL
LATER THIS EVENING. WHILE IT SEEMS RELATIVELY BENIGN...THE
TIMING/EVOLUTION OF THIS CLOUD DECK WILL ACTUALLY PLAY A VERY
IMPORTANT ROLE IN THE SHORT TERM FORECAST IN TERMS OF OVERNIGHT
LOW TEMPERATURES AND THE POTENTIAL FOR FOG DEVELOPMENT.
SIMPLE EXTRAPOLATION OF THE WESTERN EDGE OF THE CLOUD DECK FROM
VISIBLE SATELLITE SHOWS THIS CLEARING REACHING THE WESTERN EDGE OF
THE FORECAST AREA AROUND 00-02Z...AND MODEL GUIDANCE SHOWS THE
CLEARING LINE PUSHING EAST THROUGH THE OVERNIGHT HOURS. THERE/S
STILL SOME UNCERTAINTY ON HOW FAR EAST THE LINE WILL PUSH
THOUGH...WITH GENERAL CONSENSUS SHOWING IT REACHING NEAR THE I-45
CORRDIOR EARLY MONDAY MORNING. AS THIS LINE PUSHES EAST...THE
WESTERN AREAS WILL BE ALLOWED THE OPPORTUNITY TO RADIATIONALLY
COOL ENOUGH TO EXPERIENCE A LIGHT/BRIEF FREEZE. IF THE CLOUDS DO
NOT CLEAR AS QUICKLY /OR CLEAR FASTER/...OVERNIGHT LOW
TEMPERATURES WILL BE AFFECTED WITH THE ADDITION /OR LOSS/ OF A
CLOUD BLANKET. ADDITIONALLY...RELATIVELY LIGHT WINDS OVERNIGHT
WILL KEEP MIXING TO A MINIMUM...RAISING THE POTENTIAL FOR SOME FOG
DEVELOPMENT /ESPECIALLY IN AREAS THAT CLEAR/. LATEST RAP AND HRRR
VISIBILITY PROGS OFFER CONSIDERABLE DISAGREEMENT ON WHETHER OR NOT
FOG WILL DEVELOP. FOR NOW...WILL LEAVE PATCHY FOG MENTION OUT OF
THE FORECAST BUT ISOLATED DEVELOPMENT IS STILL POSSIBLE.
THE GENERAL UPPER AIR PATTERN THIS AFTERNOON HAS CONSISTED OF A
LONGWAVE TROUGH DRAPED ACROSS THE CONUS...WITH SEVERAL
DISTURBANCES ROTATING THROUGH THIS FEATURE. THE MOST NOTICEABLE
FOR US HAS BEEN THE ONE RESPONSIBLE FOR TODAY/S RAIN. TWO
DISTURBANCES FARTHER UPSTREAM /ONE OVER THE NORTHWESTERN CONUS AND
ANOTHER OVER THE NORTHWEST TERRITORIES OF CANADA/ WILL IMPACT THE
REGION/S WEATHER LATER IN THE WEEK. BEHIND TODAY/S SHORTWAVE... A
GENERALLY ZONAL FLOW BECOMES ESTABLISHED ACROSS THE SOUTHERN
CONUS. DESPITE THE PRESENCE OF AT LEAST PARTLY CLOUDY SKIES
MONDAY... ENOUGH INSOLATION WILL REACH THE SURFACE TO ALLOW
TEMPERATURES TO REBOUND INTO THE MID TO UPPER 50S.
MONDAY/S WARM UP WILL BE SHORT-LIVED AS THE DISTURBANCE OVER THE
NW CONUS CROSSES THE CENTRAL PLAINS WITH AN ARCTIC AIRMASS OOZING
THE AREA TUESDAY THROUGH THURSDAY. NORTHERLY WINDS WILL INCREASE
AS THE LEADING EDGE OF THIS ARCTIC AIR MOVES INTO THE AREA ON
TUESDAY...AND TEMPERATURES STILL REMAIN A CONCERN WITH THIS
SYSTEM. THE EXTENT OF THE MODIFICATION OF THE AIRMASS /FROM EITHER
DIABATIC OR ADIABATIC PROCESSES/ IS STILL NOT ENTIRELY CLEAR...BUT
WILL CONTINUE THE TREND OF GOING BELOW MODEL GUIDANCE AS THE EVENT
EVOLVES. THIS LEAVES THE OUTLOOK FOR MID-WEEK CHILLY WITH HIGHS
WEDNESDAY AND THURSDAY IN THE MID 40S TO NEAR 50.
THE FORMERLY CANADIAN SHORTWAVE DROPS TOWARDS THE FOUR CORNERS
REGION BY WEDNESDAY...ESTABLISHING A SOUTHWEST FLOW ALOFT /WHICH
ALLOWS FOR SOME MID LEVEL MOISTURE RETURN INTO THE REGION/ AND
INCREASING ISENTROPIC LIFT. RAIN CHANCES WILL NOT BEGIN TO
INCREASE UNTIL THURSDAY WITH THIS LIFT...AS FORECAST SOUNDINGS
SHOW RELATIVELY DRY LOWER LEVELS WILL PREVENT ANY PRECIPITATION
THAT DEVELOPS FROM REACHING THE GROUND. GUIDANCE INDICATES A
SUBTLE SHORTWAVE TROUGH MAY TRANSLATE NORTHWEST OF THE AREA LATE
THURSDAY...POSSIBLY INCREASING RAIN CHANCES FOR THE NORTHWEST
ZONES...BUT THE REGION MAY BE TOO FAR AWAY FROM THIS EXTRA SOURCE
OF LIFT TO ENHANCE OUR CHANCES.
BY FRIDAY...THUNDERSTORM CHANCES ARE ON THE INCREASE AS A COASTAL
TROUGH AND ASSOCIATED WARM FRONT DEVELOP ALONG THE TEXAS COAST.
STILL SOME QUESTIONS REGARDING EXTENT OF GULF MOISTURE
RETURN...BUT ENOUGH INSTABILITY APPEARS PRESENT AT THIS POINT TO
CONTINUE THUNDERSTORM CHANCES FRIDAY INTO FRIDAY NIGHT. AS THE
CANADIAN SHORTWAVE CROSSES TEXAS...ANOTHER COLD FRONT WILL REACH
THE AREA AND END RAIN CHANCES HEADING INTO LATE SATURDAY.
HUFFMAN
&&
.MARINE...
BOTH NORTH WINDS AND SEAS WILL DECREASE TONIGHT AND MONDAY AS HIGH
PRESSURE MOVES OVER THE AREA. THE NEXT COLD FRONT MONDAY NIGHT THROUGH
TUESDAY MORNING WILL BRING STRENGTHENING NORTHEAST WINDS ACROSS THE
WATERS. CAUTION FLAGS ARE LIKELY...AND ADVISORIES MIGHT BE NEEDED
TUESDAY THROUGH THURSDAY NIGHT. SOUTH WINDS ARE EXPECTED TO RETURN ON
FRIDAY AND FRIDAY NIGHT AS A WARM FRONT MOVES INLAND. LIGHT TO MODERATE
NORTH WINDS COME BACK OVER THE WEEKEND. 42
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 42 33 58 38 51 / 60 10 0 0 10
HOUSTON (IAH) 44 36 59 42 57 / 70 10 0 0 10
GALVESTON (GLS) 49 43 57 48 56 / 70 20 0 0 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
946 AM CST SUN DEC 28 2014
.UPDATE...
A MINOR UPDATE TO ADJUST FOR CURRENT TRENDS...AS A SHORTWAVE
TROUGH PASSES EAST OVER THE REGION TODAY. ISENTROPIC ASCENT
CONTINUES AHEAD OF THE APPROACHING TROUGH ACROSS CENTRAL TEXAS
THIS MORNING. SCATTERED AREAS OF VERY LIGHT...OCCASIONALLY MIXED
WITH SOME VERY LIGHT SLEET OR SNOW CONTINUES AS COLUMN COOLING AND
SATURATION OCCUR WITH THE LIFT AND STEEPENING MID LEVEL LAPSE
RATES MOVING ACROSS THE AREA. SURFACE TEMPERATURES CONTINUE TO
REMAIN IN THE MID-UPPER 30S...SO WE DO NOT EXPECT ANY IMPACTS ON
AREA ROADS FOR TRAVELERS...THOUGH BRIDGE AND OVERPASSES SHOULD
STILL BE TAKEN SLOWLY UNTIL THE VERY LIGHT PRECIPITATION MIXTURE
ENDS.
LIGHT RAIN WILL CONTINUE INTO THE EARLY AFTERNOON HOURS ACROSS OUR
SOUTHEAST COUNTIES WITH SHORTWAVE PROGRESSING EAST ACROSS THIS AREA.
ENVIRONMENTAL SOUNDINGS WILL BE LITTLE WARMER ALOFT ACROSS THESE
AREAS AND EXPECT MOSTLY LIGHT RAIN. SURFACE TEMPERATURES WILL WARM
INTO THE 40S. HOWEVER...AS THE CORE INCREASING MID LEVEL INSTABILITY
ROTATES ACROSS A FEW SLEET PELLET SHOWERS CANNOT BE RULED OUT EVEN
THIS AFTERNOON. CLEARING ACROSS THE NORTHWEST HALF OF THE AREA
SHOULD HELP HIGHS WARM TO AROUND 50 OR IN THE LOWER 50S WITH THE
HELP OF INCREASING INSOLATION.
05/
&&
.AVIATION...
/ISSUED 600 AM CST SUN DEC 28 2014/
VFR CONDITIONS ARE EXPECTED THROUGH MONDAY MORNING. BROKEN TO
OVERCAST MID CLOUDS THIS MORNING WILL SCATTER FROM WEST TO EAST
THIS AFTERNOON ONCE LARGE SCALE SUBSIDENCE INCREASES BEHIND A
PASSING UPPER TROUGH.
SOME BRIEF LIGHT RAIN IS POSSIBLE IN WACO THIS MORNING BUT IT
SHOULD HAVE NO SIGNIFICANT IMPACT TO AIRCRAFT OPERATIONS.
A NORTH WIND WILL PREVAIL TODAY AT SPEEDS LESS THAN 12 KNOTS. THE
WIND WILL BECOME LIGHT SOUTHEAST BY SUNSET AND REMAIN FROM THE
SOUTH/SOUTHEAST OVERNIGHT.
79
&&
.PREV UPDATE...
.UPDATE...
HAVE INCREASED POPS ACROSS OUR SOUTHWEST COUNTIES WHERE LIGHT RAIN
MAY BE OBSERVED SOON. ALSO EXPANDED POPS FURTHER NORTH BASED ON THE
LATEST RADAR TRENDS AND TRACKS OF ECHOES. LIGHT RAIN IS CURRENTLY
BE REPORTED ALONG AND SOUTH OF A LINE FROM LAMPASAS TO MEXIA TO
ATHENS. NORTH OF THIS LINE THERE IS STILL DRY AIR IN THE LOWER
LEVELS OF THE ATMOSPHERE THAT NEEDS TO BE OVERCOME/SATURATED
BEFORE ANY PRECIPITATION REACHES THE GROUND. EXPANDED THE RAIN
MENTION AS FAR NORTH AS A CISCO TO DFW TO EMORY LINE THIS MORNING.
WILL ALSO INCLUDE A MENTION FOR LIGHT SLEET MIXING WITH THE RAIN IN
AN AREA WEST OF A CLEBURNE TO TEMPLE LINE. SOME LIGHT SLEET HAS
BEEN REPORTED JUST SOUTHWEST OF THE AREA AND THE LATEST RAP RUN
INDICATES TEMPERATURES MAY BE COLD ENOUGH FOR A LITTLE BIT OF SLEET
TO MIX WITH THE RAIN FOR A FEW HOURS THIS MORNING. NO ACCUMULATIONS
OR IMPACTS ARE EXPECTED FROM THE SLEET.
82/JLD
&&
.PREV DISCUSSION... /ISSUED 404 AM CST SUN DEC 28 2014/
AN UPPER LEVEL TROUGH TO OUR WEST CONTINUES MOVING EAST AND WILL
PROVIDE LIFT FOR ADDITIONAL RAIN ACROSS OUR SOUTH AND SOUTHEASTERN
COUNTIES TODAY. THE RADAR ACROSS CENTRAL AND SOUTHEAST TEXAS HAS
LOOKED ACTIVE ALL NIGHT BUT A LEVEL OF DRY AIR IN THE LOWER LEVELS
OF THE ATMOSPHERE HAS PREVENTED MUCH PRECIPITATION FROM REACHING
THE GROUND SO FAR. EVEN THOUGH THE RADAR HAS GIVEN THE APPEARANCE
THAT IT HAS BEEN RAINING ALMOST ALL NIGHT SOUTH OF A GATESVILLE TO
ATHENS LINE...NONE OF THE AUTOMATED WEATHER STATIONS HAVE
REPORTED ANY RAIN UNTIL AN HOUR AGO. HEARNE /KLHB/ FINALLY REPORTED
RAIN ON THEIR 3 AM HOURLY OB INDICATING THAT THE LOWER LEVELS OF
THE ATMOSPHERE ARE FINALLY STARTING TO SATURATE DOWN. EXPECT OTHER
SITES IN THAT AREA TO BEGIN REPORTING LIGHT RAIN BEFORE SUNRISE.
LIGHT TO MODERATE RAIN WILL OCCUR SOUTHEAST OF A LAMPASAS TO
MIDLOTHIAN TO SULPHUR SPRINGS LINE TODAY WITH THE BEST RAIN
CHANCES IN THE MORNING HOURS. RAINFALL AMOUNTS WILL BE LIGHT AND
THE RAIN IS EXPECTED TO END THIS AFTERNOON. FORECAST SOUNDINGS
INDICATE THAT THE PRECIPITATION WILL REMAIN LIQUID WITH NO FROZEN
PRECIPITATION MIXING...EVEN AS THE UPPER LEVEL LOW APPROACHES
LATER TODAY. HOWEVER...WILL BE MONITORING FOR ANY CHANGES TO THE
LOW LEVEL TEMPERATURE PROFILE FOR POSSIBLY SOME SLEET MIXING IN.
CLOUDY SKIES THIS MORNING WILL CLEAR FROM WEST TO EAST THIS
AFTERNOON AS THE UPPER LEVEL TROUGH MOVES OVER THE REGION. THIS
WILL ALLOW FOR OUR WESTERN COUNTIES TO WARM INTO THE UPPER 40S
THIS AFTERNOON BUT OUR EASTERN COUNTIES CAN EXPECT A COOL DAY WITH
AFTERNOON TEMPS IN THE LOWER 40S DUE TO THE PERSISTENT CLOUD
COVER. WITH THE SKIES CLEARING TONIGHT AND WINDS BECOMING
LIGHT...TEMPERATURES ARE EXPECTED TO FALL INTO THE UPPER 20S AND
LOWER 30S ACROSS THE REGION. THE RETURN OF SOME HIGH CLOUD COVER
ON MONDAY WILL KEEP TEMPERATURES IN THE 50S AND LOWER 60S.
OVERALL...THE FORECAST FOR THE TUESDAY THROUGH FRIDAY TIME FRAME
HAS NOT CHANGED MUCH BUT DID MAKE SOME ADJUSTMENTS TO THE WINTER
WEATHER PRECIPITATION DURING THIS TIME PERIOD. THE ARCTIC FRONT IS
STILL EXPECTED TO ARRIVE MONDAY NIGHT/TUESDAY MORNING. IT WILL
STEADILY SPREAD ACROSS THE REGION WITH WINDS OF 10-15 MPH BEHIND
IT. THE AIR MASS WILL BE MODIFIED A LITTLE DURING THE DAY ON
TUESDAY DUE TO SOUTH AND EAST 850 MB WINDS ABOVE THE FRONT AND
WEST WINDS ABOVE 850 MB. HOWEVER...TUESDAY THROUGH WEDNESDAY NIGHT
WILL STILL BE A RATHER COLD PERIOD WITH HIGHS ONLY IN THE 30S AND
40S AND LOWS IN THE 20S AND 30S.
WE CONTINUE TO MAINTAIN A DRY FORECAST MONDAY NIGHT THROUGH
TUESDAY NIGHT AS THERE IS A LACK OF LIFT ACROSS THE REGION. WE
WILL BE IN NEAR ZONAL FLOW ALOFT AS A STRONG UPPER LEVEL LOW MOVES
DOWN THE WEST COAST BUT IT WILL STILL BE TOO FAR WEST AT THAT TIME
TO SPREAD ANY LARGE SCALE LIFT OVER OUR AREA. ISENTROPIC CHARTS
ALSO INDICATE A LACK OF LIFT IN OUR AREA DURING THIS PERIOD. WE
START TO NOTICE SOME WEAK ISENTROPIC LIFT BETWEEN THE 800-700 MB
LAYER BEGINNING WEDNESDAY IN OUR SOUTHERN ZONES. ANALYZING THIS
LAYER IN THE FORECASTED SOUNDINGS...WE SEE MOISTURE IN THE LAYER
WHERE THE LIFT IS OCCURRING...BUT THE LAYER BELOW 800 MB...AND IN
PARTICULAR BELOW 900 MB...IS DRY AND WOULD LIKELY EVAPORATE ANY
PRECIPITATION BEFORE IT REACHES THE GROUND. SO THE CHALLENGE NOW
IS WILL THE LOWER LAYER SATURATE ENOUGH FROM TOP-DOWN PROCESSES TO
ALLOW ANY PRECIPITATION TO REACH THE GROUND? THIS APPEARS TO BE A
LOW CHANCE AS THE LIFT DOES NOT LOOK STRONG ENOUGH TO GENERATE
ENOUGH PRECIPITATION TO SATURATE THE LAYER ALL THE WAY DOWN TO THE
SURFACE. THE RADAR MAY SHOW A LOT OF ECHOES ON WEDNESDAY...BUT DO
NOT ANTICIPATE PRECIPITATION WILL REACH THE GROUND. HOWEVER...WILL
LEAVE 20 POPS FOR DRIZZLE SOUTHWEST OF A CISCO TO HILLSBORO TO
FREESTONE LINE IN CASE SOME LIGHT RAIN DOES REACH THE GROUND.
DEPENDING ON THE TIME AND TEMPERATURES...THERE COULD BE A BRIEF
PERIOD OF FREEZING DRIZZLE WEST OF I-35.
OUR MAIN TIME FRAME OF CONCERN FOR FROZEN PRECIPITATION IS
WEDNESDAY NIGHT/EARLY THURSDAY MORNING AS THE ISENTROPIC LIFT
CONTINUES BUT ALSO SPREADS NORTH OVER MORE OF THE REGION AND
STRENGTHENS. THE MODELS ARE NOT OUTPUTTING ANY QPF DURING THIS 12
HOUR PERIOD FROM 6 PM WEDNESDAY TO 6 AM THURSDAY BECAUSE THEY
CONTINUE TO KEEP THE LOWER LEVELS OF THE ATMOSPHERE DRY /AS
INDICATED ON THE FORECASTED SOUNDINGS/. THE LOWER LEVELS OF THE
ATMOSPHERE WILL EVENTUALLY SATURATE DOWN AS THE ISENTROPIC LIFT
CONTINUES BUT THE QUESTION AND CHALLENGE IS WHEN WILL THAT OCCUR.
THE DETERMINISTIC MODELS SUGGEST THIS WILL NOT HAPPEN UNTIL AFTER
6 AM THURSDAY WHEN TEMPERATURES ARE ALREADY ABOVE FREEZING
/TEMPERATURES ARE EXPECTED TO EVENTUALLY RISE WEDNESDAY NIGHT UNDER
THE INFLUENCE OF WARM AIR ADVECTION DUE TO THE ISENTROPIC
LIFT/...BUT IT IS POSSIBLE THIS COULD OCCUR DURING THE NIGHT
WEDNESDAY. SO WILL KEEP A LOW CHANCE FOR LIGHT RAIN AND/OR LIGHT
FREEZING RAIN ALONG AND SOUTH OF A LINE FROM BRECKENRIDGE TO DFW
TO EMORY. THE FREEZING RAIN WILL BE MENTIONED ALONG AND WEST OF A
LINE FROM WEATHERFORD TO LAMPASAS. IF FREEZING RAIN OCCURS DURING
THE TIME FROM 6 PM WEDNESDAY TO 6 AM THURSDAY...WE DO NOT EXPECT
SIGNIFICANT IMPACTS AS TEMPERATURES WILL BE WARMING OVERNIGHT AND
THE CHANGEOVER TO LIQUID RAIN SHOULD MELT ANY MINIMAL ICE
ACCUMULATIONS. HOWEVER...IF TEMPERATURES THAT NIGHT ARE COLDER
THAN THEY ARE CURRENTLY FORECAST TO BE AND ARE REALIZED IN THE
UPPER 20S...THERE COULD BE SOME MINOR ACCUMULATIONS AND POSSIBLY
MINOR IMPACTS FOR A SHORT PERIOD OF TIME DURING THE NIGHT. IF
TEMPERATURES WERE TO FALL INTO THE UPPER 20S...THE MOST LIKELY
LOCATION FOR THIS TO HAPPEN WOULD BE WEST ON I-35.
RAIN CHANCES ARE STILL LOOKING DECENT ACROSS THE REGION ON
THURSDAY AND FRIDAY AS THE UPPER LEVEL LOW ALONG THE WEST COAST
FINALLY MOVES INTO THE SOUTHERN PLAINS. AGAIN...THIS IS EXPECTED
TO REMAIN AS LIQUID RAIN. THERE ARE SOME DIFFERENCES WITHIN THE
MODELS REGARDING THE BEST TIMING FOR RAIN CHANCES ON THESE DAYS
AND WE WILL HOPEFULLY BE ABLE TO REFINE THEM OVER THE NEXT FEW
DAYS. ONE INTERESTING FEATURE TO WATCH WILL BE THE POSSIBILITY OF
A SHORTWAVE AHEAD OF THE UPPER LOW ON THURSDAY. THE GFS DEVELOPS
THIS SHORTWAVE GIVING US BETTER RAIN CHANCES ON THURSDAY AS A
RESULT. THE ECMWF DOES NOT HAVE THIS SHORTWAVE AND THEREFORE HAS
BETTER RAIN CHANCES ON FRIDAY AS THE UPPER LEVEL LOW MOVES OVER
THE AREA. SOME THUNDER WILL BE POSSIBLE THURSDAY NIGHT AND
FRIDAY. ANOTHER FRONT IS EXPECTED BEHIND THIS SYSTEM ON SATURDAY
AND IT IS STARTING TO LOOK LIKE THE AIR BEHIND THIS FRONT COULD BE
PRETTY COLD AS WELL.
82/JLD
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 46 32 56 34 43 / 10 0 5 5 5
WACO, TX 44 27 59 33 46 / 30 5 5 5 5
PARIS, TX 43 30 51 33 44 / 10 0 5 5 5
DENTON, TX 46 27 56 28 42 / 5 0 5 5 5
MCKINNEY, TX 45 26 54 28 43 / 10 0 5 5 5
DALLAS, TX 47 32 56 35 44 / 10 0 5 5 5
TERRELL, TX 43 29 55 34 45 / 10 0 5 5 5
CORSICANA, TX 43 31 56 35 46 / 30 5 5 5 5
TEMPLE, TX 43 27 61 34 46 / 40 5 5 5 5
MINERAL WELLS, TX 47 29 57 28 40 / 5 0 5 5 5
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
79/05
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
600 AM CST SUN DEC 28 2014
.AVIATION...
VFR CONDITIONS ARE EXPECTED THROUGH MONDAY MORNING. BROKEN TO
OVERCAST MID CLOUDS THIS MORNING WILL SCATTER FROM WEST TO EAST
THIS AFTERNOON ONCE LARGE SCALE SUBSIDENCE INCREASES BEHIND A
PASSING UPPER TROUGH.
SOME BRIEF LIGHT RAIN IS POSSIBLE IN WACO THIS MORNING BUT IT
SHOULD HAVE NO SIGNIFICANT IMPACT TO AIRCRAFT OPERATIONS.
A NORTH WIND WILL PREVAIL TODAY AT SPEEDS LESS THAN 12 KNOTS. THE
WIND WILL BECOME LIGHT SOUTHEAST BY SUNSET AND REMAIN FROM THE
SOUTH/SOUTHEAST OVERNIGHT.
79
&&
.UPDATE...
HAVE INCREASED POPS ACROSS OUR SOUTHWEST COUNTIES WHERE LIGHT RAIN
MAY BE OBSERVED SOON. ALSO EXPANDED POPS FURTHER NORTH BASED ON THE
LATEST RADAR TRENDS AND TRACKS OF ECHOES. LIGHT RAIN IS CURRENTLY
BE REPORTED ALONG AND SOUTH OF A LINE FROM LAMPASAS TO MEXIA TO
ATHENS. NORTH OF THIS LINE THERE IS STILL DRY AIR IN THE LOWER
LEVELS OF THE ATMOSPHERE THAT NEEDS TO BE OVERCOME/SATURATED
BEFORE ANY PRECIPITATION REACHES THE GROUND. EXPANDED THE RAIN
MENTION AS FAR NORTH AS A CISCO TO DFW TO EMORY LINE THIS MORNING.
WILL ALSO INCLUDE A MENTION FOR LIGHT SLEET MIXING WITH THE RAIN IN
AN AREA WEST OF A CLEBURNE TO TEMPLE LINE. SOME LIGHT SLEET HAS
BEEN REPORTED JUST SOUTHWEST OF THE AREA AND THE LATEST RAP RUN
INDICATES TEMPERATURES MAY BE COLD ENOUGH FOR A LITTLE BIT OF SLEET
TO MIX WITH THE RAIN FOR A FEW HOURS THIS MORNING. NO ACCUMULATIONS
OR IMPACTS ARE EXPECTED FROM THE SLEET.
82/JLD
&&
.PREV DISCUSSION... /ISSUED 404 AM CST SUN DEC 28 2014/
AN UPPER LEVEL TROUGH TO OUR WEST CONTINUES MOVING EAST AND WILL
PROVIDE LIFT FOR ADDITIONAL RAIN ACROSS OUR SOUTH AND SOUTHEASTERN
COUNTIES TODAY. THE RADAR ACROSS CENTRAL AND SOUTHEAST TEXAS HAS
LOOKED ACTIVE ALL NIGHT BUT A LEVEL OF DRY AIR IN THE LOWER LEVELS
OF THE ATMOSPHERE HAS PREVENTED MUCH PRECIPITATION FROM REACHING
THE GROUND SO FAR. EVEN THOUGH THE RADAR HAS GIVEN THE APPEARANCE
THAT IT HAS BEEN RAINING ALMOST ALL NIGHT SOUTH OF A GATESVILLE TO
ATHENS LINE...NONE OF THE AUTOMATED WEATHER STATIONS HAVE
REPORTED ANY RAIN UNTIL AN HOUR AGO. HEARNE /KLHB/ FINALLY REPORTED
RAIN ON THEIR 3 AM HOURLY OB INDICATING THAT THE LOWER LEVELS OF
THE ATMOSPHERE ARE FINALLY STARTING TO SATURATE DOWN. EXPECT OTHER
SITES IN THAT AREA TO BEGIN REPORTING LIGHT RAIN BEFORE SUNRISE.
LIGHT TO MODERATE RAIN WILL OCCUR SOUTHEAST OF A LAMPASAS TO
MIDLOTHIAN TO SULPHUR SPRINGS LINE TODAY WITH THE BEST RAIN
CHANCES IN THE MORNING HOURS. RAINFALL AMOUNTS WILL BE LIGHT AND
THE RAIN IS EXPECTED TO END THIS AFTERNOON. FORECAST SOUNDINGS
INDICATE THAT THE PRECIPITATION WILL REMAIN LIQUID WITH NO FROZEN
PRECIPITATION MIXING...EVEN AS THE UPPER LEVEL LOW APPROACHES
LATER TODAY. HOWEVER...WILL BE MONITORING FOR ANY CHANGES TO THE
LOW LEVEL TEMPERATURE PROFILE FOR POSSIBLY SOME SLEET MIXING IN.
CLOUDY SKIES THIS MORNING WILL CLEAR FROM WEST TO EAST THIS
AFTERNOON AS THE UPPER LEVEL TROUGH MOVES OVER THE REGION. THIS
WILL ALLOW FOR OUR WESTERN COUNTIES TO WARM INTO THE UPPER 40S
THIS AFTERNOON BUT OUR EASTERN COUNTIES CAN EXPECT A COOL DAY WITH
AFTERNOON TEMPS IN THE LOWER 40S DUE TO THE PERSISTENT CLOUD
COVER. WITH THE SKIES CLEARING TONIGHT AND WINDS BECOMING
LIGHT...TEMPERATURES ARE EXPECTED TO FALL INTO THE UPPER 20S AND
LOWER 30S ACROSS THE REGION. THE RETURN OF SOME HIGH CLOUD COVER
ON MONDAY WILL KEEP TEMPERATURES IN THE 50S AND LOWER 60S.
OVERALL...THE FORECAST FOR THE TUESDAY THROUGH FRIDAY TIME FRAME
HAS NOT CHANGED MUCH BUT DID MAKE SOME ADJUSTMENTS TO THE WINTER
WEATHER PRECIPITATION DURING THIS TIME PERIOD. THE ARCTIC FRONT IS
STILL EXPECTED TO ARRIVE MONDAY NIGHT/TUESDAY MORNING. IT WILL
STEADILY SPREAD ACROSS THE REGION WITH WINDS OF 10-15 MPH BEHIND
IT. THE AIR MASS WILL BE MODIFIED A LITTLE DURING THE DAY ON
TUESDAY DUE TO SOUTH AND EAST 850 MB WINDS ABOVE THE FRONT AND
WEST WINDS ABOVE 850 MB. HOWEVER...TUESDAY THROUGH WEDNESDAY NIGHT
WILL STILL BE A RATHER COLD PERIOD WITH HIGHS ONLY IN THE 30S AND
40S AND LOWS IN THE 20S AND 30S.
WE CONTINUE TO MAINTAIN A DRY FORECAST MONDAY NIGHT THROUGH
TUESDAY NIGHT AS THERE IS A LACK OF LIFT ACROSS THE REGION. WE
WILL BE IN NEAR ZONAL FLOW ALOFT AS A STRONG UPPER LEVEL LOW MOVES
DOWN THE WEST COAST BUT IT WILL STILL BE TOO FAR WEST AT THAT TIME
TO SPREAD ANY LARGE SCALE LIFT OVER OUR AREA. ISENTROPIC CHARTS
ALSO INDICATE A LACK OF LIFT IN OUR AREA DURING THIS PERIOD. WE
START TO NOTICE SOME WEAK ISENTROPIC LIFT BETWEEN THE 800-700 MB
LAYER BEGINNING WEDNESDAY IN OUR SOUTHERN ZONES. ANALYZING THIS
LAYER IN THE FORECASTED SOUNDINGS...WE SEE MOISTURE IN THE LAYER
WHERE THE LIFT IS OCCURRING...BUT THE LAYER BELOW 800 MB...AND IN
PARTICULAR BELOW 900 MB...IS DRY AND WOULD LIKELY EVAPORATE ANY
PRECIPITATION BEFORE IT REACHES THE GROUND. SO THE CHALLENGE NOW
IS WILL THE LOWER LAYER SATURATE ENOUGH FROM TOP-DOWN PROCESSES TO
ALLOW ANY PRECIPITATION TO REACH THE GROUND? THIS APPEARS TO BE A
LOW CHANCE AS THE LIFT DOES NOT LOOK STRONG ENOUGH TO GENERATE
ENOUGH PRECIPITATION TO SATURATE THE LAYER ALL THE WAY DOWN TO THE
SURFACE. THE RADAR MAY SHOW A LOT OF ECHOES ON WEDNESDAY...BUT DO
NOT ANTICIPATE PRECIPITATION WILL REACH THE GROUND. HOWEVER...WILL
LEAVE 20 POPS FOR DRIZZLE SOUTHWEST OF A CISCO TO HILLSBORO TO
FREESTONE LINE IN CASE SOME LIGHT RAIN DOES REACH THE GROUND.
DEPENDING ON THE TIME AND TEMPERATURES...THERE COULD BE A BRIEF
PERIOD OF FREEZING DRIZZLE WEST OF I-35.
OUR MAIN TIME FRAME OF CONCERN FOR FROZEN PRECIPITATION IS
WEDNESDAY NIGHT/EARLY THURSDAY MORNING AS THE ISENTROPIC LIFT
CONTINUES BUT ALSO SPREADS NORTH OVER MORE OF THE REGION AND
STRENGTHENS. THE MODELS ARE NOT OUTPUTTING ANY QPF DURING THIS 12
HOUR PERIOD FROM 6 PM WEDNESDAY TO 6 AM THURSDAY BECAUSE THEY
CONTINUE TO KEEP THE LOWER LEVELS OF THE ATMOSPHERE DRY /AS
INDICATED ON THE FORECASTED SOUNDINGS/. THE LOWER LEVELS OF THE
ATMOSPHERE WILL EVENTUALLY SATURATE DOWN AS THE ISENTROPIC LIFT
CONTINUES BUT THE QUESTION AND CHALLENGE IS WHEN WILL THAT OCCUR.
THE DETERMINISTIC MODELS SUGGEST THIS WILL NOT HAPPEN UNTIL AFTER
6 AM THURSDAY WHEN TEMPERATURES ARE ALREADY ABOVE FREEZING
/TEMPERATURES ARE EXPECTED TO EVENTUALLY RISE WEDNESDAY NIGHT UNDER
THE INFLUENCE OF WARM AIR ADVECTION DUE TO THE ISENTROPIC
LIFT/...BUT IT IS POSSIBLE THIS COULD OCCUR DURING THE NIGHT
WEDNESDAY. SO WILL KEEP A LOW CHANCE FOR LIGHT RAIN AND/OR LIGHT
FREEZING RAIN ALONG AND SOUTH OF A LINE FROM BRECKENRIDGE TO DFW
TO EMORY. THE FREEZING RAIN WILL BE MENTIONED ALONG AND WEST OF A
LINE FROM WEATHERFORD TO LAMPASAS. IF FREEZING RAIN OCCURS DURING
THE TIME FROM 6 PM WEDNESDAY TO 6 AM THURSDAY...WE DO NOT EXPECT
SIGNIFICANT IMPACTS AS TEMPERATURES WILL BE WARMING OVERNIGHT AND
THE CHANGEOVER TO LIQUID RAIN SHOULD MELT ANY MINIMAL ICE
ACCUMULATIONS. HOWEVER...IF TEMPERATURES THAT NIGHT ARE COLDER
THAN THEY ARE CURRENTLY FORECAST TO BE AND ARE REALIZED IN THE
UPPER 20S...THERE COULD BE SOME MINOR ACCUMULATIONS AND POSSIBLY
MINOR IMPACTS FOR A SHORT PERIOD OF TIME DURING THE NIGHT. IF
TEMPERATURES WERE TO FALL INTO THE UPPER 20S...THE MOST LIKELY
LOCATION FOR THIS TO HAPPEN WOULD BE WEST ON I-35.
RAIN CHANCES ARE STILL LOOKING DECENT ACROSS THE REGION ON
THURSDAY AND FRIDAY AS THE UPPER LEVEL LOW ALONG THE WEST COAST
FINALLY MOVES INTO THE SOUTHERN PLAINS. AGAIN...THIS IS EXPECTED
TO REMAIN AS LIQUID RAIN. THERE ARE SOME DIFFERENCES WITHIN THE
MODELS REGARDING THE BEST TIMING FOR RAIN CHANCES ON THESE DAYS
AND WE WILL HOPEFULLY BE ABLE TO REFINE THEM OVER THE NEXT FEW
DAYS. ONE INTERESTING FEATURE TO WATCH WILL BE THE POSSIBILITY OF
A SHORTWAVE AHEAD OF THE UPPER LOW ON THURSDAY. THE GFS DEVELOPS
THIS SHORTWAVE GIVING US BETTER RAIN CHANCES ON THURSDAY AS A
RESULT. THE ECMWF DOES NOT HAVE THIS SHORTWAVE AND THEREFORE HAS
BETTER RAIN CHANCES ON FRIDAY AS THE UPPER LEVEL LOW MOVES OVER
THE AREA. SOME THUNDER WILL BE POSSIBLE THURSDAY NIGHT AND
FRIDAY. ANOTHER FRONT IS EXPECTED BEHIND THIS SYSTEM ON SATURDAY
AND IT IS STARTING TO LOOK LIKE THE AIR BEHIND THIS FRONT COULD BE
PRETTY COLD AS WELL.
82/JLD
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 46 32 56 34 43 / 10 0 5 5 5
WACO, TX 44 27 59 33 46 / 40 5 5 5 5
PARIS, TX 43 30 51 33 44 / 10 0 5 5 5
DENTON, TX 46 27 56 28 42 / 10 0 5 5 5
MCKINNEY, TX 45 26 54 28 43 / 10 0 5 5 5
DALLAS, TX 47 32 56 35 44 / 20 0 5 5 5
TERRELL, TX 43 29 55 34 45 / 20 0 5 5 5
CORSICANA, TX 43 31 56 35 46 / 40 5 5 5 5
TEMPLE, TX 43 27 61 34 46 / 50 5 5 5 5
MINERAL WELLS, TX 47 29 57 28 40 / 10 0 5 5 5
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
79/82
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
537 AM CST SUN DEC 28 2014
.UPDATE...
HAVE INCREASED POPS ACROSS OUR SOUTHWEST COUNTIES WHERE LIGHT RAIN
MAY BE OBSERVED SOON. ALSO EXPANDED POPS FURTHER NORTH BASED ON THE
LATEST RADAR TRENDS AND TRACKS OF ECHOES. LIGHT RAIN IS CURRENTLY
BE REPORTED ALONG AND SOUTH OF A LINE FROM LAMPASAS TO MEXIA TO
ATHENS. NORTH OF THIS LINE THERE IS STILL DRY AIR IN THE LOWER
LEVELS OF THE ATMOSPHERE THAT NEEDS TO BE OVERCOME/SATURATED
BEFORE ANY PRECIPITATION REACHES THE GROUND. EXPANDED THE RAIN
MENTION AS FAR NORTH AS A CISCO TO DFW TO EMORY LINE THIS MORNING.
WILL ALSO INCLUDE A MENTION FOR LIGHT SLEET MIXING WITH THE RAIN IN
AN AREA WEST OF A CLEBURNE TO TEMPLE LINE. SOME LIGHT SLEET HAS
BEEN REPORTED JUST SOUTHWEST OF THE AREA AND THE LATEST RAP RUN
INDICATES TEMPERATURES MAY BE COLD ENOUGH FOR A LITTLE BIT OF SLEET
TO MIX WITH THE RAIN FOR A FEW HOURS THIS MORNING. NO ACCUMULATIONS
OR IMPACTS ARE EXPECTED FROM THE SLEET.
82/JLD
&&
.AVIATION...
/ISSUED 1204 AM CST SUN DEC 28 2014/
VFR WILL PREVAIL OVER THE METROPLEX THROUGH THE PERIOD WITH JUST
MID-HIGH LEVEL CLOUD COVER. STRONG UPPER LEVEL SHORTWAVE WILL MOVE
THROUGH THE REGION MIDDAY SUNDAY. AHEAD OF THIS SYSTEM...LOTS OF
MOISTURE/LIFT WILL RESULT IN PRECIPITATION ORIGINATING AT AN
UNUSUALLY HIGH LEVEL...NEAR 22000FT. THIS PRECIP WILL BE FALLING
INTO DRY AIR BELOW IT...SO MOSTLY VIRGA IS EXPECTED IN THE
METROPLEX. HOWEVER SOME SATURATION WILL OCCUR WHICH WILL BRING
CIGS DOWN TO NEAR 10000FT BY SUNRISE. IF PRECIP INTENSITY IS
GREATER THAN EXPECTED OVER THE METROPLEX...WET BULB COOLING WOULD
RESULT IN THERMAL PROFILE FAVORABLE FOR SLEET OR SNOW. BUT THERE
IS CURRENTLY NO MODEL SHOWING THIS MUCH PRECIPITATION
AVAILABLE...WHICH WOULD BE REQUIRED TO BOTH COOL AND SATURATE
BEFORE ANY NON-LIQUID PRECIP REACHES THE GROUND. WE WILL CONTINUE
TO WATCH TRENDS TO MONITOR FOR THIS VERY REMOTE POSSIBILITY.
FOR WACO...MVFR CIGS MAY CONTINUE FOR THE NEXT HOUR OR TWO BUT VFR
CIGS NEAR 050 SHOULD PREVAIL. MORE LOW LEVEL SATURATION IS
EXPECTED THERE...SO -RA IS IN THE TAF FROM 10Z TO 16Z. THE THERMAL
PROFILE LOOKS TOO WARM FOR ANY POSSIBILITY OF WINTRY PRECIP AT
WACO EVEN AFTER WET BULB COOLING. ANY RAIN WILL ALSO BE VERY
LIGHT...AND THUS NO VSBY RESTRICTIONS ARE FORECAST.
OTHERWISE CLOUDS WILL CLEAR EARLY-MID AFTERNOON WITH LIGHT NORTH
WINDS TURNING TO THE SOUTH SUNDAY EVENING.
TR.92
&&
.PREV DISCUSSION... /ISSUED 404 AM CST SUN DEC 28 2014/
AN UPPER LEVEL TROUGH TO OUR WEST CONTINUES MOVING EAST AND WILL
PROVIDE LIFT FOR ADDITIONAL RAIN ACROSS OUR SOUTH AND SOUTHEASTERN
COUNTIES TODAY. THE RADAR ACROSS CENTRAL AND SOUTHEAST TEXAS HAS
LOOKED ACTIVE ALL NIGHT BUT A LEVEL OF DRY AIR IN THE LOWER LEVELS
OF THE ATMOSPHERE HAS PREVENTED MUCH PRECIPITATION FROM REACHING
THE GROUND SO FAR. EVEN THOUGH THE RADAR HAS GIVEN THE APPEARANCE
THAT IT HAS BEEN RAINING ALMOST ALL NIGHT SOUTH OF A GATESVILLE TO
ATHENS LINE...NONE OF THE AUTOMATED WEATHER STATIONS HAVE
REPORTED ANY RAIN UNTIL AN HOUR AGO. HEARNE /KLHB/ FINALLY REPORTED
RAIN ON THEIR 3 AM HOURLY OB INDICATING THAT THE LOWER LEVELS OF
THE ATMOSPHERE ARE FINALLY STARTING TO SATURATE DOWN. EXPECT OTHER
SITES IN THAT AREA TO BEGIN REPORTING LIGHT RAIN BEFORE SUNRISE.
LIGHT TO MODERATE RAIN WILL OCCUR SOUTHEAST OF A LAMPASAS TO
MIDLOTHIAN TO SULPHUR SPRINGS LINE TODAY WITH THE BEST RAIN
CHANCES IN THE MORNING HOURS. RAINFALL AMOUNTS WILL BE LIGHT AND
THE RAIN IS EXPECTED TO END THIS AFTERNOON. FORECAST SOUNDINGS
INDICATE THAT THE PRECIPITATION WILL REMAIN LIQUID WITH NO FROZEN
PRECIPITATION MIXING...EVEN AS THE UPPER LEVEL LOW APPROACHES
LATER TODAY. HOWEVER...WILL BE MONITORING FOR ANY CHANGES TO THE
LOW LEVEL TEMPERATURE PROFILE FOR POSSIBLY SOME SLEET MIXING IN.
CLOUDY SKIES THIS MORNING WILL CLEAR FROM WEST TO EAST THIS
AFTERNOON AS THE UPPER LEVEL TROUGH MOVES OVER THE REGION. THIS
WILL ALLOW FOR OUR WESTERN COUNTIES TO WARM INTO THE UPPER 40S
THIS AFTERNOON BUT OUR EASTERN COUNTIES CAN EXPECT A COOL DAY WITH
AFTERNOON TEMPS IN THE LOWER 40S DUE TO THE PERSISTENT CLOUD
COVER. WITH THE SKIES CLEARING TONIGHT AND WINDS BECOMING
LIGHT...TEMPERATURES ARE EXPECTED TO FALL INTO THE UPPER 20S AND
LOWER 30S ACROSS THE REGION. THE RETURN OF SOME HIGH CLOUD COVER
ON MONDAY WILL KEEP TEMPERATURES IN THE 50S AND LOWER 60S.
OVERALL...THE FORECAST FOR THE TUESDAY THROUGH FRIDAY TIME FRAME
HAS NOT CHANGED MUCH BUT DID MAKE SOME ADJUSTMENTS TO THE WINTER
WEATHER PRECIPITATION DURING THIS TIME PERIOD. THE ARCTIC FRONT IS
STILL EXPECTED TO ARRIVE MONDAY NIGHT/TUESDAY MORNING. IT WILL
STEADILY SPREAD ACROSS THE REGION WITH WINDS OF 10-15 MPH BEHIND
IT. THE AIR MASS WILL BE MODIFIED A LITTLE DURING THE DAY ON
TUESDAY DUE TO SOUTH AND EAST 850 MB WINDS ABOVE THE FRONT AND
WEST WINDS ABOVE 850 MB. HOWEVER...TUESDAY THROUGH WEDNESDAY NIGHT
WILL STILL BE A RATHER COLD PERIOD WITH HIGHS ONLY IN THE 30S AND
40S AND LOWS IN THE 20S AND 30S.
WE CONTINUE TO MAINTAIN A DRY FORECAST MONDAY NIGHT THROUGH
TUESDAY NIGHT AS THERE IS A LACK OF LIFT ACROSS THE REGION. WE
WILL BE IN NEAR ZONAL FLOW ALOFT AS A STRONG UPPER LEVEL LOW MOVES
DOWN THE WEST COAST BUT IT WILL STILL BE TOO FAR WEST AT THAT TIME
TO SPREAD ANY LARGE SCALE LIFT OVER OUR AREA. ISENTROPIC CHARTS
ALSO INDICATE A LACK OF LIFT IN OUR AREA DURING THIS PERIOD. WE
START TO NOTICE SOME WEAK ISENTROPIC LIFT BETWEEN THE 800-700 MB
LAYER BEGINNING WEDNESDAY IN OUR SOUTHERN ZONES. ANALYZING THIS
LAYER IN THE FORECASTED SOUNDINGS...WE SEE MOISTURE IN THE LAYER
WHERE THE LIFT IS OCCURRING...BUT THE LAYER BELOW 800 MB...AND IN
PARTICULAR BELOW 900 MB...IS DRY AND WOULD LIKELY EVAPORATE ANY
PRECIPITATION BEFORE IT REACHES THE GROUND. SO THE CHALLENGE NOW
IS WILL THE LOWER LAYER SATURATE ENOUGH FROM TOP-DOWN PROCESSES TO
ALLOW ANY PRECIPITATION TO REACH THE GROUND? THIS APPEARS TO BE A
LOW CHANCE AS THE LIFT DOES NOT LOOK STRONG ENOUGH TO GENERATE
ENOUGH PRECIPITATION TO SATURATE THE LAYER ALL THE WAY DOWN TO THE
SURFACE. THE RADAR MAY SHOW A LOT OF ECHOES ON WEDNESDAY...BUT DO
NOT ANTICIPATE PRECIPITATION WILL REACH THE GROUND. HOWEVER...WILL
LEAVE 20 POPS FOR DRIZZLE SOUTHWEST OF A CISCO TO HILLSBORO TO
FREESTONE LINE IN CASE SOME LIGHT RAIN DOES REACH THE GROUND.
DEPENDING ON THE TIME AND TEMPERATURES...THERE COULD BE A BRIEF
PERIOD OF FREEZING DRIZZLE WEST OF I-35.
OUR MAIN TIME FRAME OF CONCERN FOR FROZEN PRECIPITATION IS
WEDNESDAY NIGHT/EARLY THURSDAY MORNING AS THE ISENTROPIC LIFT
CONTINUES BUT ALSO SPREADS NORTH OVER MORE OF THE REGION AND
STRENGTHENS. THE MODELS ARE NOT OUTPUTTING ANY QPF DURING THIS 12
HOUR PERIOD FROM 6 PM WEDNESDAY TO 6 AM THURSDAY BECAUSE THEY
CONTINUE TO KEEP THE LOWER LEVELS OF THE ATMOSPHERE DRY /AS
INDICATED ON THE FORECASTED SOUNDINGS/. THE LOWER LEVELS OF THE
ATMOSPHERE WILL EVENTUALLY SATURATE DOWN AS THE ISENTROPIC LIFT
CONTINUES BUT THE QUESTION AND CHALLENGE IS WHEN WILL THAT OCCUR.
THE DETERMINISTIC MODELS SUGGEST THIS WILL NOT HAPPEN UNTIL AFTER
6 AM THURSDAY WHEN TEMPERATURES ARE ALREADY ABOVE FREEZING
/TEMPERATURES ARE EXPECTED TO EVENTUALLY RISE WEDNESDAY NIGHT UNDER
THE INFLUENCE OF WARM AIR ADVECTION DUE TO THE ISENTROPIC
LIFT/...BUT IT IS POSSIBLE THIS COULD OCCUR DURING THE NIGHT
WEDNESDAY. SO WILL KEEP A LOW CHANCE FOR LIGHT RAIN AND/OR LIGHT
FREEZING RAIN ALONG AND SOUTH OF A LINE FROM BRECKENRIDGE TO DFW
TO EMORY. THE FREEZING RAIN WILL BE MENTIONED ALONG AND WEST OF A
LINE FROM WEATHERFORD TO LAMPASAS. IF FREEZING RAIN OCCURS DURING
THE TIME FROM 6 PM WEDNESDAY TO 6 AM THURSDAY...WE DO NOT EXPECT
SIGNIFICANT IMPACTS AS TEMPERATURES WILL BE WARMING OVERNIGHT AND
THE CHANGEOVER TO LIQUID RAIN SHOULD MELT ANY MINIMAL ICE
ACCUMULATIONS. HOWEVER...IF TEMPERATURES THAT NIGHT ARE COLDER
THAN THEY ARE CURRENTLY FORECAST TO BE AND ARE REALIZED IN THE
UPPER 20S...THERE COULD BE SOME MINOR ACCUMULATIONS AND POSSIBLY
MINOR IMPACTS FOR A SHORT PERIOD OF TIME DURING THE NIGHT. IF
TEMPERATURES WERE TO FALL INTO THE UPPER 20S...THE MOST LIKELY
LOCATION FOR THIS TO HAPPEN WOULD BE WEST ON I-35.
RAIN CHANCES ARE STILL LOOKING DECENT ACROSS THE REGION ON
THURSDAY AND FRIDAY AS THE UPPER LEVEL LOW ALONG THE WEST COAST
FINALLY MOVES INTO THE SOUTHERN PLAINS. AGAIN...THIS IS EXPECTED
TO REMAIN AS LIQUID RAIN. THERE ARE SOME DIFFERENCES WITHIN THE
MODELS REGARDING THE BEST TIMING FOR RAIN CHANCES ON THESE DAYS
AND WE WILL HOPEFULLY BE ABLE TO REFINE THEM OVER THE NEXT FEW
DAYS. ONE INTERESTING FEATURE TO WATCH WILL BE THE POSSIBILITY OF
A SHORTWAVE AHEAD OF THE UPPER LOW ON THURSDAY. THE GFS DEVELOPS
THIS SHORTWAVE GIVING US BETTER RAIN CHANCES ON THURSDAY AS A
RESULT. THE ECMWF DOES NOT HAVE THIS SHORTWAVE AND THEREFORE HAS
BETTER RAIN CHANCES ON FRIDAY AS THE UPPER LEVEL LOW MOVES OVER
THE AREA. SOME THUNDER WILL BE POSSIBLE THURSDAY NIGHT AND
FRIDAY. ANOTHER FRONT IS EXPECTED BEHIND THIS SYSTEM ON SATURDAY
AND IT IS STARTING TO LOOK LIKE THE AIR BEHIND THIS FRONT COULD BE
PRETTY COLD AS WELL.
82/JLD
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 46 32 56 34 43 / 10 0 5 5 5
WACO, TX 44 27 59 33 46 / 40 5 5 5 5
PARIS, TX 43 30 51 33 44 / 10 0 5 5 5
DENTON, TX 46 27 56 28 42 / 10 0 5 5 5
MCKINNEY, TX 45 26 54 28 43 / 10 0 5 5 5
DALLAS, TX 47 32 56 35 44 / 20 0 5 5 5
TERRELL, TX 43 29 55 34 45 / 20 0 5 5 5
CORSICANA, TX 43 31 56 35 46 / 40 5 5 5 5
TEMPLE, TX 43 27 61 34 46 / 50 5 5 5 5
MINERAL WELLS, TX 47 29 57 28 40 / 10 0 5 5 5
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
79/82
AREA FORECAST DISCUSSION
NWS MIDLAND/ODESSA TX
1022 PM CST Sat Dec 27 2014
.DISCUSSION...
See 06z aviation discussion below.
&&
.AVIATION...
Light rain and snow will continue through the overnight hours for
parts of the area primarily affecting FST. Ceilings will gradually
get lower throughout the night and be at the lowest from 12z to 15z,
but ceilings are expected to improve by 18z Sunday. Winds will be
light and variable overnight and will shift to the southwest by the
afternoon with some possible gusts.
&&
.PREV DISCUSSION... /ISSUED 855 PM CST Sat Dec 27 2014/
UPDATE...
Update on the status of the Winter Storm Warning for the Davis
and Apache Mountains, Marfa and Alpine areas and Winter Weather
Advisory for western Pecos County.
DISCUSSION...
IR satellite imagery was showing cloud tops cooling over southwest
Texas this evening ahead of a shortwave trough over Mexico. At
28/0245Z, radar returns were showing bands of precipitation
streaking northeastward over the Warning and Advisory areas. A
few calls to Marfa, Alpine and Fort Davis yielded reports of snow
falling in those areas, with near 1" of accumulation 7 WNW of
Alpine as of 28/0130Z and snow beginning to stick in Alpine at
28/02Z, with the same in Fort Davis.
The latest NAM is trickling in, and indicates snow will continue
to fall over southwest Texas tonight. Since 4 to 6 inches of
snow are still possible in these areas, the Winter Storm Warning
will remain in effect until 28/09Z. Further, north and east there
is a dry layer in the low to mid levels so precipitation will have
to moisten this layer for appreciable precipitation to hit the
ground. When it does later tonight, surface temperatures are a
little warmer and snow accumulations should only be 1 to 2 inches
in western Pecos County. Therefore, the Winter Weather Advisory
will continue. Think precipitation will be too light any further
northward or eastward for any expansion of the Winter Weather
Advisory. Will continue to monitor.
&&
PREV DISCUSSION... /ISSUED 400 PM CST Sat Dec 27 2014/
DISCUSSION...
Current observations continue to show intermittent light snow
continuing over portions of southeast New Mexico and the western
Permian Basin. Significant snows have ended over the Guadalupe
Mountains and across Lea County New Mexico. The HRRR and other
models suggest that lingering precipitation over these northern
areas will continue to wane while redevelopment will occur over the
higher elevations of SW Texas beginning later this afternoon into
evening.
While indications are that the positive tilt upper trough is
weakening/filling as it moves across the area, which is a negative
against significant snow, current QFP for this evening and BUFKIT
sounding interrogation suggests that snow redevelopment is
likely...especially over the higher elevations of SW Texas. The
Marfa Plateau and the Davis Mountains could see significant snowfall
tonight. The western half of Pecos county could also see some minor
snow accumulations. For now, will issue a winter storm warning for
heavy snow for higher elevations of Presidio, Jeff Davis, and
Brewster County. A winter weather advisory will be issued for Pecos
County. Both the warning and advisory will be extended into the
overnight period. However, most of the activity will probably occur
this evening.
As this upper trough rapidly exits the area tomorrow morning, zonal
upper flow is expected. Surface lee trough development just east of
the Rockies will result in a quick warmup for our area tomorrow and
Monday. However, a significant cool down is forecast for later
Monday into Tuesday. The big question for now is what type of
precipitation will fall next week. With shallow cold air in place
and an expected elevated warm later, indications are that freezing
drizzle will the predominant precipitation type most of next week.
&&
.MAF WATCHES/WARNINGS/ADVISORIES...
NM...NONE.
TX...WINTER WEATHER ADVISORY until 3 AM CST Sunday FOR THE FOLLOWING
ZONES... Pecos.
WINTER STORM WARNING until 3 AM CST Sunday FOR THE FOLLOWING
ZONES... Big Bend Area...Davis/Apache Mountains Area...
Marfa Plateau.
&&
$$
99
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AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
637 PM EST MON DEC 29 2014
.SYNOPSIS...
COLD SURFACE HIGH PRESSURE WILL CONTINUE TO WEDGE DOWN FROM THE
NORTH ALONG THE APPALACHIANS TONIGHT WHILE A WEAK UPPER LEVEL
DISTURBANCE IS EXPECTED TO PASS FROM WEST TO EAST ACROSS THE AREA
TONIGHT THROUGH EARLY TUESDAY. VERY LIGHT PRECIPITATION ASSOCIATED
WITH THIS FEATURE IS EXPECTED TO CHANGE OVER TO SNOW ACROSS THE
NORTHERN PORTION OF THE REGION...WITH ACCUMULATIONS OF AN INCH OR
LESS...MAINLY ALONG AND NORTH OF U.S. 460. DRY BUT CONTINUED COLD
HIGH PRESSURE WILL BEGIN TO PUSH IN FROM THE WEST LATER TUESDAY
AND LAST UNTIL LATE IN THE WEEK.
&&
.NEAR TERM /THROUGH TUESDAY/...
AS OF 635 PM EST MONDAY...
MADE A FEW MINOR ADJUSTMENTS TO EXISTING SET OF GRIDS TO BUMP UP
PROBABILITY OF PRECIPITATION TO ACCOUNT FOR WIDESPREAD RAIN AND
DRIZZLE NOW FALLING ACROSS MUCH OF THE NEW RIVER VALLEY NORTH
TOWARD THE ALLEGHANY HIGHLANDS. DESPITE AREAL EXTENT OF
PRECIPITATION...AMOUNTS CONTINUE TO BE LIGHT...GENERALLY ONLY
AROUND 0.01 INCH/PER HOUR.
LATEST UPPER-AIR SOUNDING...RELEASED ABOUT 30 MINUTES AGO...SHOWS
LOWEST 3K FEET AGL STILL ABOVE FREEZING AND NEARLY SATURATED...SO
IT WILL TAKE MUCH OF THE EVENING...PERHAPS INTO THE EARLY MORNING
HOURS...TO DRIVE SNOW LEVELS DOWN FROM HIGHEST RIDGES TO MOUNTAIN
VALLEY AREAS...CONSISTENT WITH PREVIOUS FORECAST THINKING.
THEREFORE...SNOWFALL TOTALS STILL NOT EXPECTED TO BECOME
PROBLEMATIC AS THE NIGHT PROGRESSES...ESPECIALLY CONSIDERING
CURRENT WARM GROUND CONDITIONS AND VERY LIGHT FALL RATES.
ALSO MADE A FEW TWEAKS TO HOURLY TEMPS/DEW POINT GRIDS TO REFLECT
LATEST MESONET OBSERVATIONS...OTHERWISE REST OF FORECAST FOR
TONIGHT STILL LOOKS RIGHT ON TARGET.
AS OF 350 PM EST MONDAY...
TRICKY FCST OVERNIGHT IN REGARDS TO THE AMOUNTS AND LOCATIONS OF
VERY LIGHT PCPN AS A WEAK UPPER WAVE PASSES OVER THE DEEPENING
COLD AIR DAMMING WEDGE AS COLD SFC HIGH PRESSURE SPILLS DOWN FROM
THE NORTH. MODEL GUIDANCE ALL QUITE DIFFERENT WITH MAIN
OPERATIONAL NCEP MODELS TRENDING UPWARD SOMEWHAT WITH AS MUCH AS A
QUARTER TO TWO THIRDS OF AN INCH LIQUID EQUIV...MAINLY OVER THE
WESTERN PORTIONS. EVEN ORIGINALLY DRIER GFS NOW AS MUCH AS FOUR
TENTHS OF AN INCH OVER THE ALLEGHANY HIGHLANDS. MEANWHILE
CONVECTIVE-ALLOWING MODELS GENERALLY LESS THAN TWO TENTHS OF AN
INCH. AM LEANING ON THE LIGHT SIDE OF THE QPF OPTIONS...MORE IN
LINE WITH IDEA OF MOST OF THE HRRR RUNS...AND POSSIBILITY THAT
MORE OF THE PCPN ACTUALLY ENDS UP BACK ACROSS THE FOOTHILLS AND
PIEDMONT AGAIN. AM LEAVING SOME VERY LOW LIKELY POPS FOR TONIGHT
ACROSS PARTS OF THE MOUNTAINS...WITH HIGHER CHANCE POPS NOW ACROSS
THE FOOTHILLS. THE ISSUE OF MOISTURE DEPTH IS STILL CONCERN AS
WELL...AND WHILE I DID NOT INCLUDE ANY DRIZZLE IN THE
GRIDS...THERE COULD VERY WELL BE PERIODS OF TIME AND PORTIONS OF
THE AREA WHERE WE SEE MORE DRIZZLE DUE TO LACK OF ICE CRYSTAL
GROWTH ALOFT. THIS WOULD CUT DOWN ON ANY OF THE ALREADY LIGHT SNOW
ACCUMS IF AND WHERE THIS HAPPENS. WARM NOSE DOES NOT SEEM TO BE
PRESENT IN ANY MODEL SOUNDINGS...SO GOING WITH EITHER RAIN OR
SNOW...AND SO SFC TEMPS WILL BE THE KEY TO THAT CHANGEOVER. AS FAR
AS THE TEMPS GO...ALREADY GETTING COLDER THIS AFTERNOON THAN WE
EARLIER ANTICIPATED...AND SOME HIGHER ELEVATIONS HAVE REPORTS SOME
VERY LIGHT SNOW. THUS LOWERED TEMPS THROUGH EVENING AND OVERNIGHT
A FEW DEGREES FROM PREVIOUS FORECAST WHERE WEDGE IS EXPECTED TO BE
THE STRONGEST...AND THIS RESULTS IN A SLIGHTLY EARLIER CHANGEOVER
FROM LIGHT RAIN TO LIGHT SNOW...BUT EXCEPT FOR HIGHER
ELEVATIONS...THIS WILL STILL BE AFTER MIDNIGHT.
BOTTOM LINE IS ONLY VERY LIGHT AMOUNTS OF SNOW ACCUM
EXPECTED LATE TONIGHT AND IN THE EARLY MORNING HOURS TUESDAY...AND
IT WILL LIKELY HAVE TROUBLE STICKING AS WELL EXCEPT FOR HIGHEST
ELEVATIONS. HAVE DUSTING TO LESS THAN AN INCH GENERALLY NORTH OF
U.S. 460...AND DOWN THE BLUE RIDGE TO NEAR MEADOWS OF DAN. MAYBE
AN INCH TO ALMOST TWO ALONG HIGHEST RIDGES OF ALLEGHANY HIGHLANDS
AND ALONG BLUE RIDGE PARKWAY NORTH OF PEAKS OF OTTER. MOST ROADS
NOT EXPECTED TO SEE ANY ACCUMULATION.
ANY LINGERING PCPN EVAPORATES QUICKLY BY MIDDAY TUESDAY AS SHORT
WAVE PASSES BY AND DRIER AIR FROM NORTH CONTINUES TO FILTER IN.
WESTERLY FLOW AT RIDGE TOP LEVEL DEVELOPS BUT VERY WEAK FLOW AND
LITTLE MOISTURE TO WORK WITH SO NO ISSUES WITH ANY UPSLOPE SNOW
SHOWERS IN FAR WEST IT APPEARS. MAX TEMPS MAY BE TRICKY WITH SOME
SUNSHINE LATE IN THE DAY...BUT THIS COULD BE TOO LATE FOR LOW SUN
ANGLE TO HAVE MUCH IMPACT...SO FOR NOW GOING ON COLD SIDE OF
GUIDANCE WITH ONLY ABOUT A 5-7 DEGREE RISE FROM OVERNIGHT LOWS.
ABOVE FREEZING BY LATE MORNING SO ANY MINOR AMOUNTS OF SNOW THAT
DOES FALL WILL BE GONE BY NOON MOST LIKELY.
FINALLY...COLD WEDGE WILL KEEP SOME AREAS OF FOG AND LOW CEILINGS
AROUND...MOST ESPECIALLY NEAR THE BLUE RIDGE...BUT ALSO SOME OF
THE MTN VALLEYS AS WELL...SO BLANKED THE FOOTHILLS AND WESTWARD
WITH PATCHY FOG THROUGH TOMORROW MORNING IN THE FORECAST GRIDS BUT THIS
MAY LINGER THROUGH MUCH OF THE DAY IN SPOTS UNTIL THE WEAK WESTERLY
FLOW CAN PUSH EAST.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
AS OF 200 PM EST MONDAY...
A LARGE AREA OF HIGH PRESSURE WILL BUILD SOUTH FROM THE ROCKIES LATE
TUESDAY...THEN INTO THE SOUTHEAST U.S. BY THURSDAY EVENING KEEPING
DRY WEATHER FOR OUR AREA DURING THIS PORTION OF THE FORECAST.
ADJUSTED TEMPS DOWN A FEW DEGREES WEDNESDAY MORNING AND WEDNESDAY
AFTERNOON UNDER GOOD COLD AIR ADVECTION. BY THURSDAY MORNING
MODELS ARE IN GOOD AGREEMENT THAT SFC HIGH NOSES INTO OUR
AREA ALLOWING VALLEY WINDS TO DIMINISH. THIS COMBINED WITH THE
DRY AIR MASS IN PLACE SHOULD ALLOW TEMPS TO DROP BELOW GUIDANCE
VALUES. THE EXCEPTION WILL BE ON THE RIDGETOPS WHERE 850MB WINDS
WILL KEEP TEMPS WARMER.
HEIGHTS RISE ON THURSDAY AS AN UPPER RIDGE BEGINS TO BUILD IN THE
CENTRAL U.S. IN ADVANCE OF A SOUTHWEST U.S. UPPER LOW.
THIS...COMBINED WITH DOWNSLOPING WINDS...SHOULD ALLOW FOR A NICE
RECOVERY IN TEMPS THURSDAY. WENT A DEGREE OR TWO ABOVE GUIDANCE FOR
HIGHS.
ONLY OTHER CHANGE TO THE FORECAST WAS TO INCREASE THE WINDS ABOVE
3500 FEET WEDNESDAY AND THURSDAY AS A SWIFT MOVING NORTHERN STREAM
SHORTWAVE PASSES THROUGH THE EASTERN GREAT LAKES THROUGH NEW ENGLAND
DURING THIS TIME.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 235 PM EST MONDAY...
DRY AND SEASONABLY COOL WEATHER IS EXPECTED OVER THE BLACKSBURG
FORECAST AREA FRIDAY MORNING AS A WEAK SHORT WAVE IN NORTHERN STREAM
SCOOTS EAST THROUGH NEW ENGLAND...WITH COOL HIGH PRESSURE BUILDING
SOUTHWESTWARD IN ITS WAKE.
HOWEVER...MUCH OF THE REST OF THE LONG TERM FORECAST FROM FRIDAY
AFTERNOON INTO MONDAY APPEARS TO BE MUCH MORE UNCERTAIN...WITH
SIGNIFICANT AND PERSISTENT DISPARITY EXISTING BETWEEN THE LONGER-
TERM MODELS IN REFLECTING STRENGTH AND PLACEMENT OF NORTHERN
STREAM...AND ITS INFLUENCE ON SOUTHERN STREAM CLOSED LOW SOUTH OF
THE FOUR CORNERS AREA ON FRIDAY AFTERNOON THAT IS FORECAST TO
GRADUALLY LIFT NORTHEAST AND FILL AS IT PROGRESSES FROM THE SOUTHERN
PLAINS UP THROUGH THE OHIO VALLEY OVER THE WEEKEND.
ECMWF MAINTAINS A MORE PERSISTENT CLOSED UPPER LOW THAT IS MUCH LESS
AMPLIFIED...YET LESS PROGRESSIVE AND FURTHER SOUTH...RESULTING IN
INCREASING ISENTROPIC LIFT AND RAIN MOVING INTO AT LEAST THE
SOUTHWESTERN HALF OF THE BLACKSBURG FORECAST AREA BY/DURING FRIDAY
AFTERNOON...BUT NOT ENDING UNTIL PASSAGE OF OPENING/WEAKENING UPPER
TROF ON SUNDAY NIGHT.
GFS...WHICH REFLECTS A MORE AMPLIFIED...YET EVENTUALLY MORE
PROGRESSIVE AND NORTHERN SYSTEM PLACEMENT...HOLDS BACK RAIN SHIELD
UNTIL SATURDAY DUE TO INFLUENCE OF LARGER AND STRONGER DRY SURFACE
HIGH PRESSURE SYSTEM OVER NEW ENGLAND. GFS ALSO THE COLDER OF THE
LONGER RANGE SOLUTIONS...SINCE STRONGER SURFACE RIDGE TO NORTHEAST
WOULD LOCK COOL-WEDGE IN PLACE OVER THE BLACKSBURG FORECAST AREA.
HOWEVER...BEING MORE PROGRESSIVE...RAIN EVENT ENDS A BIT EARLIER
THAN ECMWF SOLUTION...ON SUNDAY AFTERNOON WITH PASSAGE OF UPPER
TROF...BUT WITH PERHAPS SOME COLD ADVECTION UPSLOPE PRECIPITATION
CONTINUING ACROSS THE WESTERN FLANKS OF THE APPALACHIANS UNTIL
AROUND DAYBREAK MONDAY.
BOTH MODELS HAVE BEEN INCONSISTENT IN TIMING AND PLACEMENT OF SYSTEM
THOUGH THIS TIMEFRAME FOR AT LEAST THE PAST SEVERAL RUNS...WHICH IS
NOT ALL THAT SURPRISING CONSIDERING ACTIVE NORTHERN STREAM CLASHING
WITH INITIALLY CLOSED AND STAGNANT SOUTHERN STREAM SYSTEM...SO MODEL
BLEND/ENSEMBLE APPROACH BEST TO APPLY FOR LONG TERM FORECAST UNTIL
CONFIDENCE INCREASES IN MOVING TOWARD ANY PARTICULAR SOLUTION.
NEITHER MODEL INDICATING THAT THICKNESSES WILL BE ESPECIALLY
CRITICAL FOR P-TYPE ISSUES...MEANING A MAINLY WET RATHER THAN WHITE
FORECAST OVER THE WEEKEND. HOWEVER...IF COLDER GFS SOLUTION
VERIFIES...THICKNESSES MAY BE CLOSE ENOUGH TO CRITICAL VALUES NORTH
OF HIGHWAY 64 TO WARRANT AT LEAST A NOMINAL INSERTION OF A P-TYPE
MIX DURING TIME OF PRECIPITATION ONSET...AND PERHAPS FOLLOWING
PASSAGE OF MAIN SYSTEM IN THE NORTHWESTERN MOUNTAINS ON SUNDAY NIGHT
PROVIDED THAT POST FRONTAL COLD ADVECTION IS SUFFICIENTLY STRONG.
REGARDLESS OF TIMING AND PLACEMENT DIFFERENCES...ALL LONGER RANGE
MODELS INDICATE THAT MONDAY WILL BE DRY FOLLOWING PASSAGE OF THE
MAIN UPPER SYSTEM...WITH ANY ADDITION SOUTHERN STREAM ENERGY LIKELY
TO BE DEFLECTED TO OUR SOUTH AS NORTHERN STREAM TROFING GRADUALLY
STRENGTHENS AND AMPLIFIES FROM THE UPPER GREAT LAKES EAST INTO THE
NORTHEASTERN PORTION OF THE NATION FROM MONDAY INTO THE MID WEEK
PERIOD.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
AS OF 635 PM EST MONDAY...
IFR TO LIFR CONDITIONS EXPECTED TO CONTINUE AT ALL AIRPORTS
THROUGH AT LEAST TONIGHT...AND FOR WESTERN AIRPORTS EVEN INTO
EARLY PART OF TUESDAY...UNDER THE INFLUENCE OF COLD AIR DAMMING
WHICH IS ONLY STRENGTHENING WITH TIME.
LOW CONFIDENCE FOR WHEN CONDITIONS MAY BEGIN TO BREAK OUT AND
LIFT ON TUESDAY...AND MAY HAPPEN AT KBLF SOONER THAN TAF
CURRENTLY INDICATES. MORE CONFIDENT THAT KROA AND KLYH WILL
IMPROVE TO AT LEAST MVFR DURING TUESDAY MORNING AS DRIER AIR
CONTINUES TO FILTER DOWN FROM NORTH...AND EVENTUALLY KDAN AS WELL
BEFORE 18Z.
IN ADDITION...ALL AIRPORTS EXCEPT FOR KDAN SHOULD SEE SOME VERY
LIGHT RAIN CHANGE TO LIGHT SNOW AFTER MIDNIGHT TONIGHT...BUT NOT
EXPECTED TO STICK MUCH AT ALL EXCEPT FOR THE HIGHER ELEVATION
AIRPORTS SUCH AS KLWB...AND KBCB. NOT SURE IT WILL BE COLD ENOUGH
TO REALLY STICK AT KBLF AND KROA OR KLYH. KDAN LIKELY WILL NOT
EVEN SEE CHANGEOVER. IN ANY CASE...SNOW AMOUNTS WOULD ONLY
APPROACH AN INCH IN THE WORSE-CASE SCENARIO.
EXTENDED DISCUSSION...
A LARGE AREA OF HIGH PRESSURE WILL START TO NOSE INTO THE AREA
FROM THE WEST LATER TUESDAY INTO WEDNESDAY. THIS WILL RESULT IN
GRADUAL CLEARING...CLOUD BASES LIFTING INTO THE MVFR CATEGORY
TUESDAY AFTERNOON AND TUESDAY NIGHT...BEFORE DISSIPATING WEDNESDAY
AND RETURN OF VFR.
VFR WILL THEN PREVAIL THROUGH AT LEAST THURSDAY BEFORE TRENDING
DOWN AGAIN FOR THE WEEKEND PER RETURN OF MOISTURE FROM THE
SOUTHWEST. THE NEXT LOW PRESSURE SYSTEM TO AFFECT THE AREA WILL
COME FROM THE SOUTHWEST...LOW PRESSURE DEVELOPING ALONG THE TEXAS
GULF COAST FRIDAY...THEN MOVING NORTHEAST ACROSS THE MID ATLANTIC
REGION FOR THE WEEKEND. THIS SYSTEM LOOKS LIKE IT WILL PRODUCE A
MULTI-DAY PERIOD OF SUB-VFR CONDITIONS...BEGINNING AS EARLY AS
FRIDAY NIGHT...AND LINGERING THROUGH THE WEEKEND.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...SK
NEAR TERM...SK/WERT
SHORT TERM...PH
LONG TERM...WERT
AVIATION...PM/SK/WERT
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1216 AM EST SUN DEC 28 2014
.SYNOPSIS...
A WEAK COLD FRONT WILL DRIFT SOUTHEAST INTO THE MOUNTAINS TODAY
BEFORE SPILLING SOUTH OF THE REGION LATER SUNDAY NIGHT. WEAK
WAVES OF LOW PRESSURE TRACKING ALONG THE BOUNDARY TODAY INTO
MONDAY MORNING WILL BRING PERIODS OF MOSTLY LIGHT RAIN TODAY THROUGH
EARLY MONDAY. COLD HIGH PRESSURE WILL SLOWLY BUILD EAST INTO THE
REGION BEHIND THE FRONT FOR THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH SUNDAY NIGHT/...
AS OF 830 PM EST SATURDAY...
CLOUDS HAVE QUICKLY OVERSPREAD THE REGION THIS EVENING ASSOCIATED
WITH A LEAD FAINT MID LEVEL IMPULSE IN ADVANCE OF THE MAIN PIECES
OF SOUTHERN STREAM SUPPORT TO THE SW. HOWEVER MOSTLY OF THE MID
DECK VARIETY WITH ANY -RA OR SPRINKLES CONFINED JUST WEST OF THE
CWA CLOSER TO THE UPSTREAM FRONT/JET. LATEST HRRR SHOWS SOME
INTERMITTENT -RA PERHAPS MAKING IT TO THE BLUE RIDGE AFTER
MIDNIGHT BUT WITHOUT MUCH ORGANIZATION GIVEN LINGERING DRY AIR
ALOFT PER EVENING SOUNDINGS...AND BEST LIFT WEST-NW OF THE REGION
UNTIL DAYBREAK. THUS SLOWED DOWN MAIN CORRIDOR OF POPS A BIT MORE
OVERNIGHT AS MAY BE DURING SUNDAY BEFORE BETTER COVERAGE ARRIVES
AS SEEN VIA THE LATEST NAM. OTHER CONCERN WITH LOW TEMPS AS THE
CURRENT CLOUD CANOPY HAS TENDED TO STOP FALLS FOR THE MOMENT WITH
MANY LOCATIONS STILL IN THE 50S. IR PICS DO SHOW SOME BREAKS
HEADING THIS WAY OUT OF TN SO STILL SOME POTENTIAL TO SEE SOME
SPOTS SNEAK BACK DOWN GIVEN DRY AIR. HOWEVER APPEARS EVEN WITH
SOME ADDED COOLING BY LATE RAINFALL THAT WILL NEED TO RAISE LOWS
A CAT OR TWO MOST SPOTS.
PREVIOUS VALID DISCUSSION AS OF 340 PM EST SATURDAY...
THE AFTERNOON MILD TEMPERATURES ALONG WITH INCREASING CLOUD COVER
FROM THE SOUTHWEST MAY RESULT IN SOME MILD TEMPS OVERNIGHT
TONIGHT...ESPECIALLY IN THE WEST WHERE CLOUD COVER WILL BE
THICKEST SOONER. IN THE EAST...CLOUDS WILL NOT THICKEN UP UNTIL
SOME LATE AFT/EARLY EVENING RADIATIONAL COOLING...SO MAY END UP
BEING COOLER IN PARTS OF THE PIEDMONT THERE THAN IN MTNS. WENT
WITH OR SLIGHTLY WARMER THAN GUIDANCE AT SOME OF THE HIGHER
ELEVATION LOCATIONS...AND WITH COOLER MAV GUIDANCE IN EAST.
OTHERWISE...MAIN ISSUE OVERNIGHT IS TIMING OF PRECIP HEADED
NORTHEAST OUT OF GULF COAST AREA WITH SHORT WAVE AHEAD OF THE
APPROACHING COLD FRONT FROM THE WEST. A LITTLE CONCERNED ABOUT
AMOUNT OF CONVECTION DOWN THERE NOW ACTING IN SOME WAY TO ROB SOME
OF THE MOISTURE...AS WELL AS VERY DRY AIRMASS WE CURRENTLY HAVE IN
PLACE THAT COULD HELP SLOW DOWN ARRIVAL. MODEL TRENDS...AND HIGH
RES CONVECTIVE-ALLOWING VERSIONS...NOW HOLD PRECIP OFF UNTIL MAYBE
JUST BEFORE 12Z IN FAR SW AND FAR WEST PART OF AREA. SO LOWERED
POPS SLIGHTLY...MAINLY FROM 06-12Z TIME FRAME....AND ESPECIALLY
ACROSS NORTHEAST PART OF AREA WHERE IT LOOKS LIKELY THAT NO PRECIP
WILL REACH PAST ROANOKE BEFORE THEN. WHATEVER DOES REACH FAR SW BY
EARLY MORNING WILL BE QUITE LIGHT.
FOR SUNDAY...MAIN BAND OF STEADIER RAIN WILL MOVE IN FROM MID
MORNING THROUGH EARLY AFTERNOON. LEANING TOWARD NAM/ECWMF/SREF
IDEA THAT BEST CHANCES WILL BE FROM BLUE RIDGE WEST...WITH MORE
SCATTERED LIGHTER PRECIP INITIALLY IN PIEDMONT...ALTHOUGH 12Z GFS
WOULD DISAGREE. THEN THIS WAVE MOVES OUT BY LATER AFTERNOON BUT
WITH LINGERING MOISTURE KEEPING HIGH POPS IN WEST AND REDUCED TO
CHANCE IN PIEDMONT FOR LATE IN DAY INTO EARLY EVENING.
NEXT WAVE THEN ARRIVES ALONG BOUNDARY BY EVENING...AND THIS ZONE
OF STEADIER RAIN APPEARS MOST LIKELY TO TAKE A TRACK A LITTLE MORE
TO SOUTH OF FIRST ONE...WITH FOOTHILLS TO PIEDMONT GETTING MOST OF
THE MODERATE RAINFALL. OTHER THAN GFS...SEEING SOME TRENDS OVER
LOWERING AMOUNTS WITH THIS...WHICH IS PARTLY REFLECTIVE OF
WEAKENING UPPER WAVE BEING STRETCHED WITH TIME AS WELL AS SOME
MOISTURE STEALING FROM CONVECTION WELL TO SOUTH. NOT LOOKING AT
NEARLY ENOUGH RAINFALL FOR ANY PROBLEMS. SEE THE HYDRO SECTION
BELOW FOR MORE DETAILS ON THAT.
TEMPS THROUGH THIS PERIOD WILL BE MILD...ALTHOUGH SOME COOLER AIR
WILL FILTER INTO WESTERN APPALACHIAN SLOPES BY EARLY MONDAY
MORNING...BUT NOT COLD ENOUGH FOR ANY SNOW...EVEN AT HIGHEST
ELEVATIONS.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 300 PM EST SATURDAY...
THE LAST WAVE IN THE SERIES ALONG A SLOW-MOVING CLOD FRONT SHOULD BE
EXITING TOWARD THE ATLANTIC COAST FROM EARLY MONDAY THROUGH THE DAY
WITH POPS SLOWLY DIMINISHING. COLD AIR ADVECTION BEHIND THIS SYSTEM
SLOW TO DEVELOP DURING THE DAY SO HIGHS SHOULD BE ABLE TO BOUNCE
BACK SOME FROM MORNING LOWS AND WILL GENERALLY RANGE FROM UPPER 30S
NW TO UPPER 40S SE UNDER STILL MOSTLY CLOUDY SKIES. LINGERING RAIN
SHOWERS ON THE BACK END OF THIS SYSTEM WILL ENCOUNTER THE INCREASING
SOUTHWARD SPILL OF COLDER AIR AND MAY CAUSE A CHANGE OVER TO SNOW
SHOWERS IN THE HIGHER TERRAIN OF THE NORTHWEST CWA BY EVENING MONDAY
AND HAVE INTRODUCED VERY LIGHT SNOW ACCUMULATIONS..LESS THAN 1 INCH
IN THOSE COLDER AREAS...MAINLY GREENBRIER AND BATH COUNTIES. COLDER
AIR EMANATING FROM THE MASSIVE HIGH OVER THE WESTERN AND CENTRAL
CONUS WILL OOZE EASTWARD AND SOUTHWARD OVERNIGHT MONDAY AND THROUGH
THE DAY TUESDAY AS H85 TEMPS FALL BELOW 0C ACROSS THE ENTIRE CWA BY
TUESDAY EVENING AND CONTINUE TO SLIP INTO EARLY WEDNESDAY. HIGHS
TUESDAY WILL BE CHILLY..RANGING FROM L/M 30S WEST TO MID-40S
SE...ACTUALLY A FEW DEGREES BELOW LATE DECEMBER CLIMO. WEDNESDAY
MORNING LOWS FALL BACK CLOSE TO ABOUT NORMAL FOR THIS TIME OF
YEAR...NEAR 20F NW TO UPPER 20S SE.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 430 PM EST SATURDAY...
LONG RANGE MODELS...AT LEAST FOR WEDNESDAY AND THURSDAY ARE IN
AGREEMENT WITH FAIR CONTINUITY AS WE TRANSITION INTO THE NEW
YEAR. BROAD UPPER LEVEL TROUGH IS PROGGED TO EXTEND FROM EASTERN
CANADA...SOUTHWEST THROUGH THE CENTRAL CONUS INTO A CUTOFF AREA OF
LOW PRESSURE OVER SOUTHERN CALIFORNIA. A HIGH AMPLITUDE RIDGE WILL
BE POSITIONED OFF THE PAC NW COAST. THIS PATTERN FAVORS COLD
TEMPERATURES PERSISTING OVER THE NORTHERN CONTINENTAL UNITED
STATES (CONUS) AND SOUTHWARD OVER THE PLAINS...AND MILDER AIR
CONFINED TO THE EXTREME SOUTHEAST CONUS...I.E. FLORIDA. FOR THE
MID ATLANTIC WE WILL LIKELY END UP IN THE TRANSITION ZONE...OR
PRETTY CLOSE TO NORMAL TO FINISH OUT THE WEEK. WORST CASE...WE MAY
END UP 5 DEGREES OR SO BELOW NORMAL FOR NEW YEARS DAY...BUT
NOTHING EXTREME.
AFTER THURSDAY THE MODELS DIVERGE...WHICH IS TO BE EXPECTED SINCE
THEY DO NOT HANDLE CUTOFF LOWS VERY WELL...AND ESPECIALLY THOSE
THAT EJECT FROM THE DESERT SOUTHWEST. WITHIN THE EVOLVING MEAN
PATTERN THE PRIMARY FEATURE OF INTEREST WILL BE THE UPPER LOW
WHICH ALL GUIDANCE CLOSES OFF OVER/NEAR CA/AZ INITIALLY BUT THEN
DIVERGE ON WHEN THE LOW OPENS UP AND MOVES EAST DURING THE FRIDAY
SATURDAY TIME FRAME. THERE IS A FAIR AMOUNT OF MODEL/ENSEMBLE
SPREAD REGARDING THE TIMING AND TO A SOMEWHAT LESSER DEGREE TRACK
OF THE UPPER LOW. THE OPERATIONAL RUN OF THE GFS IS 12-24 HOURS
FASTER THAN THE ECMWF...WHICH MAKES A DIFFERENCE IN WHETHER IT
PRECIPITATES HERE ON FRIDAY VS SATURDAY. THIS HIGH SPREAD/LOW
CONFIDENCE FORECAST FAVORS AN ENSEMBLE MEAN APPROACH FOR BOTH
FRIDAY AND SATURDAY...THE FORECAST REFLECTING A BLEND...WITH CHC
PRECIP BOTH FRIDAY AND SATURDAY...THE GREATEST POPS FAVORING
FRIDAY NIGHT WHERE THE BLENDED SOLUTIONS OVERLAP. TIMING AND
TRACK OF THE SYSTEM WILL ALSO DETERMINE P-TYPE. TEMPERATURES LOOK
TO BE BORDERLINE CRITICAL FRIDAY...SUGGESTING AT LEAST SOME
WINTRY MIX IF PRECIP ARRIVES FRIDAY MORNING. IF ONSET HOLDS OFF
UNTIL LATER FRIDAY...THE P-TYPE WILL BE MOSTLY RAIN.
&&
.AVIATION /04Z SUNDAY THROUGH THURSDAY/...
AS OF 1145 PM EST SATURDAY...
VFR CONTINUES TO PREVAIL TONIGHT WITH SOMEWHAT LOWER CIGS IN SPOTS
OVER THE WEST WHERE HAVE SEEN A FEW SPRINKLES. STILL EXPECTING
OVERALL CIGS TO REMAIN IN THE 4-6K FT RANGE UNDER AREAS OF MID
DECK OVERNIGHT SO APPEARS WILL STAY MAINLY VFR AT ALL LOCATIONS
FOR AT LEAST A FEW MORE HOURS.
DEEPER MOISTURE AHEAD OF THE UPSTREAM COLD FRONT AND ASSOCIATED
INITIAL WAVE WILL PUSH NE INTO THE SE WEST VA SITES AROUND
DAYBREAK SUNDAY WITH MORE IN THE WAY OF WIDESPREAD MVFR CIGS WEST
OF THE BLUE RIDGE SUNDAY MORNING. THIS WILL ALSO BE FOLLOWED BY
PATCHY LIGHT RAIN WHICH SHOULD ARRIVE AT KBLF/KLWB JUST PRIOR TO
SUNRISE IF NOT A BIT SOONER...BUT MAINLY LIGHT...THUS OVERALL VFR
VSBYS IN ANY PRECIP EARLY SUNDAY. FIRST WAVE OF LIGHT RAIN WILL
ALSO SCOOT ACROSS SUNDAY MORNING WITH MAINLY VFR CIGS AND VSBYS IN
THE SPOTTY COVERAGE FROM THE BLUE RIDGE EAST...AND MVFR OVER THE
WEST ESPCLY KBLF/KLWB. APPEARS THIS WILL MAINLY GO TO MOISTEN THE
COLUMN BEFORE ANOTHER ROUND OF STEADIER RAIN ARRIVES OVER THE FAR
WEST/NW IN THE AFTERNOON. THIS IS WHEN IT APPEARS THAT CIGS/VSBYS
WILL DETERIORATE QUICKER PENDING HOW FAST THINGS BECOME SATURATED
IN THE WAKE OF THE INITIAL RAINFALL. THIS LOOKS TO HAPPEN IN THE
MID/LATE AFTERNOON TIME FRAME ESPCLY SE WEST VA SITES WHERE LIKELY
WITHIN STEADIER RAINFALL...AND BLUE RIDGE LOCATIONS GIVEN SOMEWHAT
TRAPPED LOW LEVEL MOISTURE. STILL WONT GO AS LOW AS THE LATEST NAM
IN SHOWING WIDESPREAD LIFR/IFR AT ALL SITES BY LATE IN THE DAY OR
EARLY EVENING. HOWEVER TRENDING INTO SOLID IFR WEST...MIX OF
MVFR/OCNL IFR BLUE RIDGE INCLUDING KBCB/KROA...AND MAINLY MVFR AT
KDAN/KLYH PENDING DEGREE OF PRECIP THEY SEE SUNDAY MORNING.
FRONT WILL SLOWLY PUSH EAST ACROSS THE AREA SUNDAY NIGHT AS
ANOTHER AREA OF LOW PRESSURE TRACKS UP THE BOUNDARY BRINGING MORE
WIDESPREAD RAINFALL TO SOUTHERN/EASTERN SECTIONS INTO EARLY
MONDAY. THIS LOOKS TO BE THE BEST TIME TO SEE WIDESPREAD IFR CIGS
AND MVFR/IFR VSBYS AT ALL LOCATIONS EXCLUDING PERHAPS KLWB THAT
MAY STAY WITH ONLY MVFR CONDITIONS JUST NORTH OF THE MAIN PRECIP
SHIELD. OTRW EXPECTING PLENTY OF LOW CLOUDS...-RA AS WELL AS
DRIZZLE/FOG TO COVER MUCH OF THE REGION SUNDAY NIGHT...WITH ONLY
SLOW IMPROVEMENT INTO MONDAY IN THE WAKE OF THE FRONT GIVEN LOW
LEVEL NE FLOW.
EXTENDED DISCUSSION...
THE FRONT DRIFTS OFF TO THE SE MONDAY NIGHT INTO TUESDAY WHILE
LEAVING PLENTY OF RESIDUAL LOW LEVEL MOISTURE IN ITS WAKE. HIGH
CONFIDENCE IN STAYING SUB-VFR MONDAY NIGHT WITH MORE FOG/DRIZZLE
AROUND OVERNIGHT. SLOW DRYING TO TAKE SHAPE ON TUESDAY AS A LARGE
AREA OF HIGH PRESSURE STARTS TO NOSE IN FROM THE WEST. HOWEVER MAY
TAKE UNTIL AFTERNOON FOR EASTERN SITES TO RETURN TO VFR WHILE
LINGERING LOW CLOUDS COULD CAUSE MVFR CIGS TO PERSIST OVER THE
WEST UNTIL LATE IN THE DAY. SOME SPOTTY LIGHT RAIN OR WINTRY
PRECIP MAY ALSO OCCUR EARLY TUESDAY AS A WEAK TROUGH OF LOW
PRESSURE REDEVELOPS OVER THE MOUNTAINS. OTRW HIGH PRESSURE BUILDS
EAST WEDNESDAY INTO THURSDAY WITH GOOD FLYING CONDITIONS RETURNING
UNDER VFR.
&&
.HYDROLOGY...
AS OF 300 PM EST SATURDAY...
RIVER MODEL RUNS FROM THE VARIOUS RFCS FROM THIS MORNING INCORPORATE
THE UPCOMING WET PERIOD WITH BASIN AVERAGE QPF VALUE ACROSS THE
HYDROLOGIC SERVICE AREA BASINS RANGING FROM ABOUT 0.75 INCHES IN THE
UPPER JAMES TO AS MUCH AS 1.20 INCHES OVER THE LOWER DAN. THE
RESULTING RIVER FORECASTS BRING STAGE UP SEVERAL FEET...BUT STILL
WELL WITHIN BANKFULL...SO NO FLOODING ISSUES EXPECTED. SOILS ARE
FAIRLY WET BUT RAINFALL RATES ARE EXPECTED TO BE MODEST SO FLASH
FLOODING NOT AN ISSUE EITHER.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/SK
NEAR TERM...JH/SK
SHORT TERM...PC
LONG TERM...PM
AVIATION...JH/RCS/SK
HYDROLOGY...PC
YOU CAN SEE AN ILLUSTRATED VERSION OF THIS FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
Area Forecast Discussion
National Weather Service Spokane WA
955 PM PST SAT DEC 27 2014
.SYNOPSIS...
Scattered snow showers will continue overnight into Sunday with
light to moderate accumulations in the Idaho Panhandle...Cascade
Crest...and portions of Eastern Washington. Bitterly cold
northeast winds will develop by Monday and continue into Monday
night. Temperatures will be well below average with dry conditions
most of next week as arctic high pressure settles over the Inland
Northwest.
&&
.DISCUSSION...
Steady snow has ended and the region is transitioning into an
unstable atmosphere. The most consistent snow shower activity will
be in the oropgraphically favored areas including the Idaho
Mountains, Cascade Crest, and Blue Mtns. However, there are at
least two vorticity maximums spinning in a line from Ern WA to
Central BC on the cyclonic side of the upper level jet. Each of
these will bring the potential for clusters of snow showers...some
which could bring quick bursts of 1-2 inches. HRRR suggest far NE
WA may encounter one of these waves now and another in a few hours
so opted to leave Winter Storm Warning going with wording of
localized accumulations. It is conceivable that these same
local accumulations hit the Okanogan Valley, Spokane Area, or
Washington Palouse but given the low confidence and above freezing
temperatures from Spokane to Pullman, opted to cancel highlights.
&&
.AVIATION...
06Z TAFs: The region has transitioned to the cool and unstable
side of the Polar Jet and steady wdsprd pcpn has waned. The focus
now will be several smaller scale circulations evident via
satellite from SE WA to Central BC. These waves will dig south
through the region during the next 12-18 hours bringing clusters
of rain/snow showers eventually becoming all snow. Any
accumulations will be localized and carry low confidence. Moist
boundary layer conditions will deliver a low confidence
ceiling/vis fcst as well and fcst may be optimistic. A push of
cooler and drier air from Canada will arrive Sunday evening
swinging winds around to the NE and incr the chance for light snow
showers with the frontal passage. Accumulations with this feature
will be light and snow will be more light and fluffy compared to
the wet nature observed Saturday. /sb
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 27 31 18 21 5 14 / 80 30 20 10 0 0
Coeur d`Alene 27 31 17 20 3 14 / 100 50 20 10 0 0
Pullman 29 33 19 23 3 14 / 100 70 30 30 10 0
Lewiston 32 38 24 29 9 19 / 100 60 40 30 10 0
Colville 26 33 20 24 1 18 / 60 30 20 10 0 0
Sandpoint 27 32 18 20 2 15 / 100 40 20 10 10 0
Kellogg 26 30 15 17 -3 11 / 100 70 40 20 10 0
Moses Lake 27 33 23 29 8 22 / 20 20 50 30 0 0
Wenatchee 28 34 25 30 12 23 / 20 20 60 40 0 0
Omak 25 29 21 26 4 17 / 20 10 40 20 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Winter Storm Warning until 4 PM PST Sunday for Central Panhandle
Mountains-Lewis and Southern Nez Perce Counties.
Winter Storm Warning until 4 AM PST Sunday for Coeur d`Alene
Area-Idaho Palouse-Northern Panhandle.
WA...Winter Storm Warning until 4 PM PST Sunday for Northeast Blue
Mountains.
Winter Storm Warning until 4 AM PST Sunday for Northeast
Mountains.
Winter Weather Advisory until 4 AM PST Sunday for East Slopes
Northern Cascades.
&&
$$
AREA FORECAST DISCUSSION
NWS PORTLAND OR
929 PM PST SAT DEC 27 2014
.SYNOPSIS...A COLD FRONT HAD MOVED THROUGH SOUTHWEST WASHINGTON
EARLIER THIS EVENING...AND WILL FINISH MOVING THROUGH NORTHWEST
OREGON BY MIDNIGHT. BRISK ONSHORE FLOW WILL CONTINUE BEHIND THE FRONT
TONIGHT AND SUNDAY AND PRODUCE MORE SHOWERS OVER THE AREA...
ESPECIALLY OVER THE HIGHER TERRAIN...THEN INCREASE SUNDAY NIGHT INTO
MONDAY NIGHT WITH EVEN MORE SHOWERS AS A SECONDARY COLD DISTURBANCE
MOVES THROUGH FROM THE NORTH. LOOK FOR OCCASIONAL SNOW TO CONTINUE IN
THE CASCADES AND ACROSS THE PASSES INTO MONDAY. COLDER HIGH PRESSURE
WILL THEN BUILD INTO THE COLUMBIA BASIN AND CAUSE COLD EAST WINDS TO
DEVELOP ACROSS THE AREA MONDAY AFTERNOON AND INCREASE MONDAY NIGHT
AND TUESDAY FOR DRY CONDITIONS BUT WITH VERY COLD TEMPERATURES AND
ASSOCIATED COLD WIND CHILLS. THE DRY COLD AND BLUSTERY PATTERN WILL
CONTINUE MUCH OF THE COMING WEEK...WITH THE NEXT CHANCE FOR SOME
PRECIPITATION LATE IN THE WEEK AND NEXT WEEKEND...WITH A POSSIBILITY
OF WINTER WEATHER AT LOW ELEVATIONS.
&&
.SHORT TERM...TONIGHT THROUGH TUESDAY...A FAIRLY STRONG COLD FRONT
MOVED THROUGH SOUTHWEST WASHINGTON AND MOST OF NORTHWEST OREGON THIS
EVENING...WITH VERY GOOD PRECIPITATION AMOUNTS IN THE MOUNTAINS...
DECENT AMOUNTS AT THE COAST...AND LESSER AMOUNTS IN THE VALLEYS. THE
STEADIER RAIN IS MOSTLY OVER THOUGH THE FRONT DOES LINGER A BIT IN
EASTERN LANE COUNTY BUT SHOULD MOVE OUT BY MIDNIGHT. THE MODELS SHOW
A PRETTY STEADY STREAM OF ONSHORE FLOW AND SHOWERS COMING IN FROM THE
WEST NORTHWEST OVERNIGHT WHICH SHOULD KEEP THE SNOW GOING THE
CASCADES. WE MAY SEE SOME RAIN SHADOWING IN THE VALLEYS THOUGH.
THE ONSHORE FLOW CONTINUES SUNDAY BUT MAY NOT BE QUITE AS STRONG AS
TONIGHT...THEN PICKS UP SUNDAY NIGHT INTO MONDAY AS A TRAILING
SECONDARY COLD DISTURBANCE DROPS DOWN FROM THE NORTH SUNDAY NIGHT AND
MONDAY MORNING. THIS SHOULD GIVE US AN INCREASE IN THE SHOWERS AND
SNOW IN THE CASCADES. WITH HOLIDAY TRAVEL EXPECTED SUNDAY AND
POSSIBLY MONDAY...HAVE DECIDED TO CONTINUE THE SNOW ADVISORIES IN THE
CASCADES INTO MONDAY.
WE MAY SEE SOME ACCUMULATING SNOW IN THE CASCADE FOOTHILLS AND HIGHER
COAST RANGE SUNDAY NIGHT INTO MONDAY AS WELL...AS SNOW LEVELS DROP TO
AROUND 2000 FEET BY SUNDAY EVENING AND TO NEAR OR BELOW 1000 FEET BY
MONDAY MORNING. AMOUNTS COULD GET CLOSE TO ADVISORY THRESHOLDS.
AFTER THAT...DRY WEATHER WILL DEVELOP AS COLD HIGH PRESSURE WILL
SPREAD DOWN INTO THE COLUMBIA BASIN AND CAUSE COLD EAST WINDS TO
DEVELOP THROUGH THE COLUMBIA RIVER GORGE AND UP AND OVER THE CASCADES
AND ACROSS THE REMAINDER OF SOUTHWEST WASHINGTON AND NORTHWEST
OREGON. THE WINDS WILL DEVELOP BY MONDAY AFTERNOON...AND INCREASE
MONDAY NIGHT AND TUESDAY AND BE QUITE STRONG...POSSIBLY ENOUGH FOR
SOME AREAS OF TREE DAMAGE AND POWER OUTAGES. THE EAST WINDS WILL
USHER IN THE COLDEST AIR MASS OF THE SEASON SO FAR...AND IN
COMBINATION WITH THE WIND WILL PRODUCE SOME COLD WIND CHILLS. AN
SPECIAL WEATHER STATEMENT HAS BEEN ISSUED DISCUSSING ALL OF THIS.
TOLLESON
.LONG TERM...TUESDAY NIGHT THROUGH SATURDAY...COLD...DRY WEATHER
CONTINUES THROUGH THE DAY WEDNESDAY...AS HIGH PRESSURE SITS OVER THE
AREA. ECMWF AND GFS ARE STARTING TO KEY IN ON A LOW PRESSURE SYSTEM
THAT WILL DIVE DOWN THE COAST LATE THIS WEEK...SHIFTING WINDS BACK TO
THE NORTHWEST AND BRINGING PRECIPITATION. THERE IS STILL CONSIDERABLE
UNCERTAINTY ON THE TIMING OF THIS SYSTEM...THOUGH. IF THIS PANS OUT
AS FORECAST RIGHT NOW...A CHANCE OF WINTRY MIX ALL THE WAY TO THE
FLOOR OF THE WILLAMETTE VALLEY IS POSSIBLE INITIALLY THURSDAY NIGHT
INTO EARLY FRIDAY. AS THE FRONT MOVES THROUGH TEMPERATURES ARE STILL
BELOW FREEZING...UNTIL ONSHORE WINDS AND DAYTIME HEATING CAN BRING
TEMPERATURES BACK ABOVE FREEZING LATE FRIDAY MORNING OR AFTERNOON. IF
THE FRONT IS SLOWER THAN FORECAST AND MOVES THROUGH DURING THE DAY ON
FRIDAY...TEMPERATURES WILL MORE LIKELY BE ABOVE FREEZING KEEPING IT
ALL RAIN. RAIN LOOKS TO CONTINUE INTO SATURDAY. -MCCOY
&&
.AVIATION...A COLD FRONT WILL CONTINUE TO MOVE THROUGH THE THE AREA
THIS EVENING BRINGING MVFR CONDITIONS TO AREAS NEAR THE FRONT. IN THE
WAKE OF THE FRONT...THE STEADY RAIN WILL BECOME MORE SHOWERY AND
CONDITIONS WILL GENERALLY IMPROVE TO VFR FOR THE OVERNIGHT HOURS AS
COOLER AND MORE UNSTABLE AIR MOVES IN. THERE MAY BE SOME MVFR OR EVEN
IFR CONDITIONS IN SOME SHELTERED AREAS WHERE FOG MAY FORM. THE
MID-LEVEL C0LD AIR ADVECTION WEAKENS AFTER DAYBREAK SUNDAY...SO THERE
IS A CHANCE AN EXTENDED CLEAR PERIOD COULD ALLOW IFR TO LIFR FOG TO
FORM...PARTICULARLY AT KEUG. A WEAK LOW PRESSURE WILL DROP SOUTHWARD
ACROSS THE AREA SUNDAY EVENING. AS THIS SYSTEM
APPROACHES...CONDITIONS COULD DETERIORATE INTO THE MVFR CATEGORY
AFTER 4PM SUNDAY.
KPDX AND APPROACHES...MAINLY VFR CONDITIONS THIS EVENING AND
OVERNIGHT AS MID LEVEL COLD ADVECTION DESTABILIZES THE LOWER
ATMOSPHERE IN THE WAKE OF THE FRONTAL PASSAGE. AN OCCASIONAL MVFR CIG
WILL BE POSSIBLE...BUT THESE SHOULD BE SHORT LIVED. ADDITIONAL FLIGHT
RESTRICTIONS COULD CREEP INTO THE TERMINAL TOWARDS 4PM SUNDAY
AFTERNOON AS A WEAK LOW PRESSURE DROPS SOUTHWARD WEST OF THE
CASCADES.
&&
.MARINE...A FRONT WILL DROP SOUTHWARD ACROSS THE WATERS THIS
EVENING...BRINGING GUSTY NORTHWEST WINDS AND HIGH SEAS TO THE WATERS.
WINDS AND SEAS SHOULD BE HIGHEST ACROSS THE NORTHERN COASTAL WATERS
WITH SOLID SMALL CRAFT ADVISORY WINDS WITH GUSTS OF 25 TO 30 KT. SEAS
SHOULD GENERALLY TOP OUT IN THE 11 TO 13 FT RANGE TOWARDS THE CENTRAL
AND NORTH OREGON COAST. EXPECT SEAS TO START SUBSIDING SUNDAY
AFTERNOON AND SUNDAY NIGHT...LIKELY DROPPING BELOW 10 FT MONDAY
MORNING.
A WEAK LOW PRESSURE MAY DEVELOP AND DRIFT SOUTHWARD ACROSS THE INNER
WATERS LATE SUNDAY NIGHT OR MONDAY MORNING...BUT IMPACTS TO MARINE
INTERESTS WILL BE FAIRLY MINIMAL. AS THE LOW PRESSURE DROPS SOUTH OF
THE AREA...OFFSHORE PRESSURE GRADIENTS WILL STRENGTHEN RAPIDLY. THIS
WILL ALLOW GUSTY EAST TO NORTHEAST WINDS TO DEVELOP ACROSS THE WATERS
FOR THE SECOND HALF OF MONDAY...LASTING THROUGH AT LEAST THE MIDDLE
PART OF NEXT WEEK. WITH NO MAJOR WESTERLY SWELLS...SEA CONDITIONS
WILL PRIMARILY BE DOMINATED BY WIND WAVES DURING THE PEAK OF THE EAST
WINDS, WHICH WILL LIKELY OCCUR MONDAY NIGHT INTO TUESDAY. TW/CN
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...WINTER WEATHER ADVISORY UNTIL NOON PST MONDAY FOR CASCADES IN
LANE COUNTY-NORTHERN OREGON CASCADES.
WA...WINTER WEATHER ADVISORY UNTIL 7 AM PST MONDAY FOR SOUTH
WASHINGTON CASCADES.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 10 PM PST SUNDAY FOR
COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR OUT
60 NM.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 9 AM PST MONDAY
FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT
60 NM.
SMALL CRAFT ADVISORY FOR WINDS UNTIL 6 PM PST SUNDAY FOR COASTAL
WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 1 PM PST
SUNDAY.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
Area Forecast Discussion
National Weather Service Spokane WA
852 PM PST SAT DEC 27 2014
.SYNOPSIS...
Scattered snow showers will continue overnight into Sunday with
light to moderate accumulations in the Idaho Panhandle...Cascade
Crest...and portions of Eastern Washington. Bitterly cold
northeast winds will develop by Monday and continue into Monday
night. Temperatures will be well below average with dry conditions
most of next week as arctic high pressure settles over the Inland
Northwest.
&&
.DISCUSSION...
Steady snow has ended and the region is transitioning into an
unstable atmosphere. The most consistent snow shower activity will
be in the oropgraphically favored areas including the Idaho
Mountains, Cascade Crest, and Blue Mtns. However, there are at
least two vorticity maximums spinning in a line from Ern WA to
Central BC on the cyclonic side of the upper level jet. Each of
these will bring the potential for clusters of snow showers...some
which could bring quick bursts of 1-2 inches. HRRR suggest far NE
WA may encounter one of these waves now and another in a few hours
so opted to leave Winter Storm Warning going with wording of
localized accumulations. It is conceivable that these same
local accumulations hit the Okanogan Valley, Spokane Area, or
Washington Palouse but given the low confidence and above freezing
temperatures from Spokane to Pullman, opted to cancel highlights.
&&
.AVIATION...
00Z TAFs: A cold upper level trough and surface low pressure will
persist over the region through the next 24 hours. The eastern TAF
sites including KGEG...KCOE...KSFF and KPUW will be under threat
for IFR and LIFR conditions in snow through 02-03Z as moist isentropic
ascent continues. Conditions will improve after 02Z-03Z as a dry
slot moves through the region...but deterioration will occur
after 06Z with a cold front band of snow showers. KLWS will
probably remain VFR through this evening but with snow or rain
showers nearby. KMWH and KEAT will benefit from downslope off the
cascades for primarily VFR conditions. On Sunday cold air aloft
will destabilize the air mass leading to scattered snow showers
over the eastern TAF sites promoting occasional periods of low
MVFR or IFR conditions in snow. /MJF
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 27 31 18 21 5 14 / 80 30 20 10 0 0
Coeur d`Alene 27 31 17 20 3 14 / 100 50 20 10 0 0
Pullman 29 33 19 23 3 14 / 100 70 30 30 10 0
Lewiston 32 38 24 29 9 19 / 100 60 40 30 10 0
Colville 26 33 20 24 1 18 / 60 30 20 10 0 0
Sandpoint 27 32 18 20 2 15 / 100 40 20 10 10 0
Kellogg 26 30 15 17 -3 11 / 100 70 40 20 10 0
Moses Lake 27 33 23 29 8 22 / 20 20 50 30 0 0
Wenatchee 28 34 25 30 12 23 / 20 20 60 40 0 0
Omak 25 29 21 26 4 17 / 20 10 40 20 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Winter Storm Warning until 4 PM PST Sunday for Central Panhandle
Mountains-Lewis and Southern Nez Perce Counties.
Winter Storm Warning until 4 AM PST Sunday for Coeur d`Alene
Area-Idaho Palouse-Northern Panhandle.
WA...Winter Storm Warning until 4 PM PST Sunday for Northeast Blue
Mountains.
Winter Storm Warning until 4 AM PST Sunday for Northeast
Mountains.
Winter Weather Advisory until 4 AM PST Sunday for East Slopes
Northern Cascades.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
500 PM CST SUN DEC 28 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 200 PM CST SUN DEC 28 2014
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED A STRONG SHORTWAVE DROPPING SOUTH THROUGH THE NORTHWESTERN
U.S. AND BRITISH COLUMBIA...A COLLECTION OF WEAK SHORTWAVES OVER
WYOMING AND NEBRASKA AND AN UPPER LOW OVER NORTHERN ONTARIO. DESPITE
A MAINLY ZONAL FLOW COMING ACROSS THE FORECAST AREA...A COLD FRONT
WAS EVIDENT AT THE SURFACE DROPPING SOUTH INTO THE AREA. THIS FRONT
EXTENDED FROM NORTHERN LOWER MI TO LA CROSSE TO SIOUX CITY IA. LOW
CLOUDS WITH A FEW FLURRIES WERE EVIDENT IN A 100 MILE WIDTH ZONE
BEHIND THE FRONT...WHILE SKIES WERE MAINLY SUNNY AHEAD OF IT. 925MB
TEMPS OF -6 TO -10C AND SUN HAS ALLOWED TEMPERATURES TO MOSTLY CLIMB
INTO THE 20S WITH A FEW NEAR 30 READINGS IN FAR SOUTHWEST WISCONSIN.
COLDEST READINGS HAVE BEEN OVER THE NORTHWEST 1/3 OF THE AREA WITH
MORE SNOW AND BEING FIRST TO EXPERIENCE THE FROPA. MUCH COLDER AIR
TRYING TO SINK SOUTH BEHIND THE FRONT WITH 925MB TEMPS IN THE -15 TO
-20C RANGE OVER MUCH OF NORTH DAKOTA INTO NORTHERN MN.
THE MAIN FEATURE OF INTEREST FOR THE SHORT TERM IS THE COLLECTION OF
WEAK SHORTWAVES OVER WYOMING AND NEBRASKA. MODELS ARE IN GOOD
AGREEMENT BRINGING THESE SHORTWAVES ACROSS IOWA AND SOUTHERN
PORTIONS OF THE FORECAST AREA LATE TONIGHT INTO MONDAY MORNING. WITH
THESE SHORTWAVES COMES INCREASING MID LEVEL FRONTOGENESIS...MOSTLY
IN THE WAKE OF THE CURRENT COLD FRONT DROPPING SOUTH THROUGH THE
FORECAST AREA. PROBLEM IS THAT AT THE TIME OF THE BEST MID LEVEL
LIFT...THERE IS ENOUGH DRY AIR BELOW THE MID CLOUDS TO ABSORB MUCH
OF THE SNOW PRODUCTION. WHEN THAT DRY AIR MOSTLY SATURATES...THE
LIFT IS GONE. THEREFORE...A MENTION OF FLURRIES AS THE PREVIOUS
FORECAST HAD SEEMS REASONABLE. MOST 28.12Z GUIDANCE OF QPF CONTINUES
TO PRODUCE A DRY FORECAST TOO.
COLD ADVECTION BEHIND THE COLD FRONT PASSAGE WILL BE THE MAIN FACTOR
IN DROPPING TEMPERATURES TONIGHT...SINCE CLOUDS SHOULD BE IN PLACE
FOR MOST LOCATIONS. 925MB TEMPS FALL TO -10C SOUTH TO -15C NORTH...
WHICH SHOULD ALLOW TEMPERATURES TO DROP INTO THE SINGLE DIGITS NORTH
TO NEAR 20 SOUTH. THE COLDEST READINGS ARE EXPECTED IN TAYLOR/CLARK
COUNTIES WHERE SOME CLEARING IS POSSIBLE THIS EVENING BEFORE
MID/HIGH CLOUDS OVERSPREAD. FURTHER 925MB TEMP COOLING TAKES PLACE
ON MONDAY DUE TO PERSISTENT NORTHERLY FLOW. READINGS DROP TO -13C
SOUTH TO -17C NORTH...WHICH MEANS HIGHS WILL STRUGGLE TO CLIMB MUCH
THAN A FEW DEGREES ABOVE THE LOWS TONIGHT.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 200 PM CST SUN DEC 28 2014
THE MAIN STORY MONDAY NIGHT THROUGH TUESDAY NIGHT IS THE COLD. ALL
MODELS CONTINUE TO DROP A 1050-1060MB HIGH SOUTHWARD ALONG THE LEE
SIDE OF THE ROCKIES DURING THIS TIME...WITH COLD ADVECTION
DOWNSTREAM OF THE HIGH OVER THE FORECAST AREA. 925MB TEMPS FALL TO
-16 TO -19C BY 12Z TUESDAY AND TO AROUND -20C BY 06Z WEDNESDAY. MUCH
OF THE TIME PERIOD SHOULD BE MOSTLY CLEAR...OUTSIDE OF SOME PASSING
CLOUDS TUESDAY AFTERNOON AND EVENING ASSOCIATED WITH A SHORTWAVE
TROUGH OF ARCTIC ORIGIN MOVING THROUGH. THE SOUTHEAST HALF OF THE
FORECAST AREA WILL STAY WARMER DUE TO THE FACT OF NO SNOW ON THE
GROUND...BUT STILL EXPECT CHILLY READINGS...ESPECIALLY TUESDAY NIGHT
WITH THE COLDEST AIR IN PLACE. A PERSISTENT NORTHWEST BREEZE SHOULD
EXIST SINCE WE ARE NOT UNDER THE CENTER OF THE HIGH...THEREFORE...
WIND CHILLS BECOME A FACTOR. ADVISORIES ARE LIKELY TO BE NEEDED BOTH
NIGHTS...PARTICULARLY OVER NORTH CENTRAL WI AND POSSIBLY PORTIONS OF
SOUTHEAST MN AND NORTHEAST IA TOO.
SOME MODERATION TAKES PLACE WEDNESDAY INTO THURSDAY / NEW YEARS EVE
AND DAY / IN RESPONSE TO A POTENT SHORTWAVE TROUGH DIGGING INTO
NORTHERN ONTARIO AND LAKE SUPERIOR. HOWEVER...THIS MODERATION TAKES
PLACE AT THE EXPENSE OF HIGHER WINDS...WHICH MEANS A PERSISTENT WIND
CHILL FACTOR. FIRST...THE WESTERLY WINDS ADVECT DOWNSLOPED AIR OFF
THE ROCKIES TOWARDS THE FORECAST AREA...BOOSTING 925MB TEMPS TO
AROUND -14C BY 00Z THU AND -8 TO -10C BY 00Z FRI. THESE READINGS
SHOULD HELP BRING HIGHS BACK UP INTO THE TEENS ON WEDNESDAY AND
MOSTLY INTO THE 20S ON THURSDAY. NOW REGARDING THE WINDS...925MB
SPEEDS ARE PROGGED TO INCREASE TO THE 35 TO 45 KT RANGE AT 00Z THU
BEFORE RELAXING SOME FOR DURING THE DAY THURSDAY. WITH PLENTY OF SUN
ON WEDNESDAY...WE SHOULD SEE SOME GOOD MIXING OF THOSE WINDS. RIGHT
NOW IT APPEARS GUSTS MAY TOP OUT AROUND 30 KT...HIGHEST IN SOUTHEAST
MN...BUT WORTH MONITORING OVER THE NEXT FEW DAYS TO SEE IF THESE END
UP HIGHER. SOMETHING ELSE TO MONITOR ON THURSDAY IS POSSIBLE LIGHT
SNOW AS A COLD FRONT AND SHORTWAVE TROUGH DROP THROUGH THE NORTHERN
PORTION OF THE FORECAST AREA. HAVE ADDED SOME CHANCE POPS TO
LOCATIONS NORTH OF I-90.
FOR FRIDAY INTO SATURDAY...WE NEED TO WATCH CLOSELY THE EVOLUTION
AND TRACK OF AN UPPER LOW THAT COMES OUT OF THE SOUTHWESTERN U.S..
THIS UPPER LOW...FORMED BY THE CURRENT STRONG SHORTWAVE DIVING SOUTH
THROUGH THE NORTHWESTERN U.S....IS PRESENTLY PROGGED TO GET LIFTED
THROUGH MISSOURI AND INTO LOWER MI ON SATURDAY. SOME WARM ADVECTION
SNOW COULD BEGIN TO APPROACH THE REGION AS EARLY AS LATE FRIDAY WELL
DOWNSTREAM OF THIS UPPER LOW...OR FROM A FRONTOGENESIS BAND TRACKING
ACROSS THE NORTHERN U.S.. HOWEVER...FRIDAY NIGHT INTO SATURDAY SEEM
TO BE THE BETTER CHANCES IN SEEING A COLD CONVEYOR BELT BAND OF SNOW
TRACK ACROSS THE FORECAST AREA FROM THE UPPER LOW. IF THIS SYSTEM
TRACKS FARTHER NORTHWEST...MAY END UP WITH AN ADVISORY LEVEL SNOW.
NOTE THAT THE 28.12Z ECMWF/UKMET/CANADIAN PRESENT A MUCH SLOWER IDEA
WITH THE UPPER LOW...RESULTING IN A MUCH DRIER SCENARIO...THUS
PLENTY OF UNCERTAINTY AND ONLY 30-40 PERCENT PRECIPITATION CHANCES.
POST THE SATURDAY SYSTEM...A STRONG SURGE OF ARCTIC AIR LOOKS POISED
TO IMPACT THE REGION FOR SUNDAY INTO EARLY NEXT WEEK. IT COULD BE
NEARLY AS COLD AS THE JANUARY 5-7TH 2014 ARCTIC OUTBREAK...AND JUST
HAPPENS TO BE THE SAME DATES. THE 28.12Z MODEL CYCLE DEPICTS THE GFS
COLDER WHILE THE ECMWF WAS WARMER AND A BIT MORE DELAYED...WAITING
UNTIL MONDAY TO DRIVE THE COLD AIR IN. NEEDLESS TO SAY...STAY
TUNED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 500 PM CST SUN DEC 28 2014
BAND OF 2-3 KFT CLOUDS SINKING SOUTHWARD ACROSS THE REGION EARLY
THIS EVENING. RAGGED AND THINNER ACROSS SOUTHEAST MN...MAKING LOW
CIGS LESS ASSURED AT KRST. THESE LOWER CIGS SHOULD SINK SOUTH OF
KRST/KLSE BY 06Z...WITH SOME HIGH CLOUDINESS TO CONTEND WITH THROUGH
MONDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM....AJ
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
200 PM CST SUN DEC 28 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 200 PM CST SUN DEC 28 2014
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED A STRONG SHORTWAVE DROPPING SOUTH THROUGH THE NORTHWESTERN
U.S. AND BRITISH COLUMBIA...A COLLECTION OF WEAK SHORTWAVES OVER
WYOMING AND NEBRASKA AND AN UPPER LOW OVER NORTHERN ONTARIO. DESPITE
A MAINLY ZONAL FLOW COMING ACROSS THE FORECAST AREA...A COLD FRONT
WAS EVIDENT AT THE SURFACE DROPPING SOUTH INTO THE AREA. THIS FRONT
EXTENDED FROM NORTHERN LOWER MI TO LA CROSSE TO SIOUX CITY IA. LOW
CLOUDS WITH A FEW FLURRIES WERE EVIDENT IN A 100 MILE WIDTH ZONE
BEHIND THE FRONT...WHILE SKIES WERE MAINLY SUNNY AHEAD OF IT. 925MB
TEMPS OF -6 TO -10C AND SUN HAS ALLOWED TEMPERATURES TO MOSTLY CLIMB
INTO THE 20S WITH A FEW NEAR 30 READINGS IN FAR SOUTHWEST WISCONSIN.
COLDEST READINGS HAVE BEEN OVER THE NORTHWEST 1/3 OF THE AREA WITH
MORE SNOW AND BEING FIRST TO EXPERIENCE THE FROPA. MUCH COLDER AIR
TRYING TO SINK SOUTH BEHIND THE FRONT WITH 925MB TEMPS IN THE -15 TO
-20C RANGE OVER MUCH OF NORTH DAKOTA INTO NORTHERN MN.
THE MAIN FEATURE OF INTEREST FOR THE SHORT TERM IS THE COLLECTION OF
WEAK SHORTWAVES OVER WYOMING AND NEBRASKA. MODELS ARE IN GOOD
AGREEMENT BRINGING THESE SHORTWAVES ACROSS IOWA AND SOUTHERN
PORTIONS OF THE FORECAST AREA LATE TONIGHT INTO MONDAY MORNING. WITH
THESE SHORTWAVES COMES INCREASING MID LEVEL FRONTOGENESIS...MOSTLY
IN THE WAKE OF THE CURRENT COLD FRONT DROPPING SOUTH THROUGH THE
FORECAST AREA. PROBLEM IS THAT AT THE TIME OF THE BEST MID LEVEL
LIFT...THERE IS ENOUGH DRY AIR BELOW THE MID CLOUDS TO ABSORB MUCH
OF THE SNOW PRODUCTION. WHEN THAT DRY AIR MOSTLY SATURATES...THE
LIFT IS GONE. THEREFORE...A MENTION OF FLURRIES AS THE PREVIOUS
FORECAST HAD SEEMS REASONABLE. MOST 28.12Z GUIDANCE OF QPF CONTINUES
TO PRODUCE A DRY FORECAST TOO.
COLD ADVECTION BEHIND THE COLD FRONT PASSAGE WILL BE THE MAIN FACTOR
IN DROPPING TEMPERATURES TONIGHT...SINCE CLOUDS SHOULD BE IN PLACE
FOR MOST LOCATIONS. 925MB TEMPS FALL TO -10C SOUTH TO -15C NORTH...
WHICH SHOULD ALLOW TEMPERATURES TO DROP INTO THE SINGLE DIGITS NORTH
TO NEAR 20 SOUTH. THE COLDEST READINGS ARE EXPECTED IN TAYLOR/CLARK
COUNTIES WHERE SOME CLEARING IS POSSIBLE THIS EVENING BEFORE
MID/HIGH CLOUDS OVERSPREAD. FURTHER 925MB TEMP COOLING TAKES PLACE
ON MONDAY DUE TO PERSISTENT NORTHERLY FLOW. READINGS DROP TO -13C
SOUTH TO -17C NORTH...WHICH MEANS HIGHS WILL STRUGGLE TO CLIMB MUCH
THAN A FEW DEGREES ABOVE THE LOWS TONIGHT.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 200 PM CST SUN DEC 28 2014
THE MAIN STORY MONDAY NIGHT THROUGH TUESDAY NIGHT IS THE COLD. ALL
MODELS CONTINUE TO DROP A 1050-1060MB HIGH SOUTHWARD ALONG THE LEE
SIDE OF THE ROCKIES DURING THIS TIME...WITH COLD ADVECTION
DOWNSTREAM OF THE HIGH OVER THE FORECAST AREA. 925MB TEMPS FALL TO
-16 TO -19C BY 12Z TUESDAY AND TO AROUND -20C BY 06Z WEDNESDAY. MUCH
OF THE TIME PERIOD SHOULD BE MOSTLY CLEAR...OUTSIDE OF SOME PASSING
CLOUDS TUESDAY AFTERNOON AND EVENING ASSOCIATED WITH A SHORTWAVE
TROUGH OF ARCTIC ORIGIN MOVING THROUGH. THE SOUTHEAST HALF OF THE
FORECAST AREA WILL STAY WARMER DUE TO THE FACT OF NO SNOW ON THE
GROUND...BUT STILL EXPECT CHILLY READINGS...ESPECIALLY TUESDAY NIGHT
WITH THE COLDEST AIR IN PLACE. A PERSISTENT NORTHWEST BREEZE SHOULD
EXIST SINCE WE ARE NOT UNDER THE CENTER OF THE HIGH...THEREFORE...
WIND CHILLS BECOME A FACTOR. ADVISORIES ARE LIKELY TO BE NEEDED BOTH
NIGHTS...PARTICULARLY OVER NORTH CENTRAL WI AND POSSIBLY PORTIONS OF
SOUTHEAST MN AND NORTHEAST IA TOO.
SOME MODERATION TAKES PLACE WEDNESDAY INTO THURSDAY / NEW YEARS EVE
AND DAY / IN RESPONSE TO A POTENT SHORTWAVE TROUGH DIGGING INTO
NORTHERN ONTARIO AND LAKE SUPERIOR. HOWEVER...THIS MODERATION TAKES
PLACE AT THE EXPENSE OF HIGHER WINDS...WHICH MEANS A PERSISTENT WIND
CHILL FACTOR. FIRST...THE WESTERLY WINDS ADVECT DOWNSLOPED AIR OFF
THE ROCKIES TOWARDS THE FORECAST AREA...BOOSTING 925MB TEMPS TO
AROUND -14C BY 00Z THU AND -8 TO -10C BY 00Z FRI. THESE READINGS
SHOULD HELP BRING HIGHS BACK UP INTO THE TEENS ON WEDNESDAY AND
MOSTLY INTO THE 20S ON THURSDAY. NOW REGARDING THE WINDS...925MB
SPEEDS ARE PROGGED TO INCREASE TO THE 35 TO 45 KT RANGE AT 00Z THU
BEFORE RELAXING SOME FOR DURING THE DAY THURSDAY. WITH PLENTY OF SUN
ON WEDNESDAY...WE SHOULD SEE SOME GOOD MIXING OF THOSE WINDS. RIGHT
NOW IT APPEARS GUSTS MAY TOP OUT AROUND 30 KT...HIGHEST IN SOUTHEAST
MN...BUT WORTH MONITORING OVER THE NEXT FEW DAYS TO SEE IF THESE END
UP HIGHER. SOMETHING ELSE TO MONITOR ON THURSDAY IS POSSIBLE LIGHT
SNOW AS A COLD FRONT AND SHORTWAVE TROUGH DROP THROUGH THE NORTHERN
PORTION OF THE FORECAST AREA. HAVE ADDED SOME CHANCE POPS TO
LOCATIONS NORTH OF I-90.
FOR FRIDAY INTO SATURDAY...WE NEED TO WATCH CLOSELY THE EVOLUTION
AND TRACK OF AN UPPER LOW THAT COMES OUT OF THE SOUTHWESTERN U.S..
THIS UPPER LOW...FORMED BY THE CURRENT STRONG SHORTWAVE DIVING SOUTH
THROUGH THE NORTHWESTERN U.S....IS PRESENTLY PROGGED TO GET LIFTED
THROUGH MISSOURI AND INTO LOWER MI ON SATURDAY. SOME WARM ADVECTION
SNOW COULD BEGIN TO APPROACH THE REGION AS EARLY AS LATE FRIDAY WELL
DOWNSTREAM OF THIS UPPER LOW...OR FROM A FRONTOGENESIS BAND TRACKING
ACROSS THE NORTHERN U.S.. HOWEVER...FRIDAY NIGHT INTO SATURDAY SEEM
TO BE THE BETTER CHANCES IN SEEING A COLD CONVEYOR BELT BAND OF SNOW
TRACK ACROSS THE FORECAST AREA FROM THE UPPER LOW. IF THIS SYSTEM
TRACKS FARTHER NORTHWEST...MAY END UP WITH AN ADVISORY LEVEL SNOW.
NOTE THAT THE 28.12Z ECMWF/UKMET/CANADIAN PRESENT A MUCH SLOWER IDEA
WITH THE UPPER LOW...RESULTING IN A MUCH DRIER SCENARIO...THUS
PLENTY OF UNCERTAINTY AND ONLY 30-40 PERCENT PRECIPITATION CHANCES.
POST THE SATURDAY SYSTEM...A STRONG SURGE OF ARCTIC AIR LOOKS POISED
TO IMPACT THE REGION FOR SUNDAY INTO EARLY NEXT WEEK. IT COULD BE
NEARLY AS COLD AS THE JANUARY 5-7TH 2014 ARCTIC OUTBREAK...AND JUST
HAPPENS TO BE THE SAME DATES. THE 28.12Z MODEL CYCLE DEPICTS THE GFS
COLDER WHILE THE ECMWF WAS WARMER AND A BIT MORE DELAYED...WAITING
UNTIL MONDAY TO DRIVE THE COLD AIR IN. NEEDLESS TO SAY...STAY
TUNED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1130 AM CST SUN DEC 28 2014
AVIATION WEATHER PRETTY GOOD TODAY BUT WATCHING BAND OF MVFR
CEILINGS SLOWLY PUSHING SOUTH WITH WEAK FRONT. THIS CLOUD BAND HAS
BEEN THINING A BIT BUT STILL EXPECTING IT TO TRACK SOUTH CLOSER TO
INTERSTATE 90 CORRIDOR THIS AFTERNOON. TIMING OF THAT SAME BAND
CLEARING OUT A BIT MORE TOUGH BUT GUIDANCE SUGGESTS EARLY MONDAY
MORNING WITH VFR CEILINGS REMAINING IN PLACE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION.....SHEA
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
1057 PM PST MON DEC 29 2014
...WINDY AND COLDER WEATHER ON THE WAY FOR THE END OF 2014...
.SYNOPSIS...A FAST MOVING STORM SYSTEM WILL MOVE SOUTHEAST ACROSS
NEVADA TONIGHT BRINGING A SLIGHT CHANCE OF SHOWERS MAINLY IN THE HILLS.
COLDER AND WINDIER CONDITIONS WILL SETTLE OVER THE AREA TUESDAY AND
WEDNESDAY BEHIND THIS SYSTEM. A WARMING TREND WILL RETURN BY LATE
THIS WEEK.
&&
.DISCUSSION...AS OF 9:00 PM PST MONDAY...A COLD UPPER LEVEL LOW
OVER SOUTHEAST OREGON WILL DRIVE SOUTHEAST DURING THE NIGHT WITH THE
TROUGH AXIS MOVING THROUGH THE AREA LATE TONIGHT. THE SYSTEM HAS
VERY LITTLE MOISTURE BUT RECENT HRRR MODEL RUNS HAVE SHOWN
ISOLATED CONTOURS OF ONE TO TWO-HUNDREDTHS OF PRECIP IN THE HILLS.
A SLIGHT CHANCE OF SHOWERS IS IN THE FORECAST FOR TONIGHT BUT MOST
LIKELY ANY PRECIP WILL FALL OVER THE HILLS.
WINDS WILL INCREASE AS THIS TROUGH AXIS MOVES THROUGH WITH MODELS
SHOWING 925 MB WINDS INCREASING TO 35-45 KT RANGE TUESDAY MORNING.
MODELS ALSO SHOW DECENT OMEGA VALUES AFTER THE TROUGH PASSES
INDICATING THAT WINDS ALOFT COULD MIX DOWN TO THE SURFACE.
THEREFORE A WIND ADVISORY IS IN EFFECT BEGINNING TUESDAY MORNING
IN THE NORTH AND EAST BAY HILLS AND SANTA CRUZ MOUNTAINS FOR GUSTS
UP TO 55-60 MPH...AND MIDDAY TUESDAY FOR THE REST OF THE SFO BAY
AREA WITH GUSTS TO 40-45 MPH. STRONG WINDS WILL CONTINUE THROUGH
TUESDAY NIGHT AND MAY EVEN BE SLIGHTLY STRONGER THAN TUESDAY
MORNING. THESE STRONG WINDS WILL BRING DOWN SOME TREES AND CAUSE
POWER OUTAGES AS THE SOIL REMAINS FAIRLY WET FROM RAINS EARLIER
THIS MONTH.
WINDS WILL DECREASE BY MIDDAY WEDNESDAY AS THE LOW MOVES FURTHER
EAST AND AN UPPER LEVEL RIDGE BUILDS IN FROM THE WEST. COLD
NORTHERLY FLOW WILL CONTINUE OVER THE AREA THROUGH WEDNESDAY AND
WITH THE WINDS DIMINISHING IT WILL SET UP A COLD NIGHT FOR NEW
YEARS EVE. TEMPERATURES WILL DROP INTO THE 20S IN MANY OF THE
INLAND VALLEYS WITH LOWER TO MID 30S IN THE URBAN AREAS AROUND
OAKLAND-SAN JOSE. A FROST ADVISORY MAY BE NEEDED FOR MOST OF THE
SFO BAY AREA WEDNESDAY NIGHT.
TEMPERATURES WILL SLOWLY WARM UP THURSDAY THROUGH SUNDAY AS THE
UPPER LEVEL RIDGE MOVES OVER THE WEST COAST. IN THE LONG
RANGE...MODELS CONTINUE TO STRUGGLE WITH WHETHER THERE WILL BE
RAIN IN OUR CWA AROUND THE MIDDLE OF NEXT WEEK. LATEST GFS AND
ECMWF INDICATE A CHANCE FOR RAIN FOR AT LEAST THE NORTHERN PART OF
THE DISTRICT.
&&
.AVIATION...AS OF 10:45 PM PST MONDAY...THE LIMITED BAND OF LOW
AND MID LEVEL CLOUDINESS ASSOCIATED WITH THE MOSTLY DRY COLD
FRONT SWEEPING SOUTHWARD THROUGH CENTRAL CALIFORNIA IS NOW PASSING
THROUGH THE MONTEREY BAY REGION. BEHIND IT SKIES ARE EXPECTED TO
REMAIN MOSTLY CLEAR THROUGH THE NIGHT...AS THE BOUNDARY LAYER AIR
MASS LOOKS TO REMAIN SUFFICIENTLY DRY AND WELL MIXED AS TO
PRECLUDE ANY DEVELOPMENT OF FOG OR LOW CLOUDS.
ON TUESDAY HOWEVER...COUPLING OF A RAPIDLY INCREASING NORTH TO
SOUTH PRESSURE GRADIENT WITH STRONG NORTH-TO-NORTHEAST FLOW ALOFT WILL
RESULT IN INCREASINGLY STRONG WINDS OVER THE DISTRICT. KEY QUESTIONS ARE
WHEN...WHERE...AND TO WHAT DEGREE THESE WILL MIX DOWN TO THE
SURFACE AT LOW ELEVATIONS. HIGH RESOLUTION LOCAL MODEL OUTPUT
INDICATES THIS WILL IN FACT PROGRESSIVELY OCCUR AT SFO BAY AREA
TAF SITES DURING THE DAY ON TUESDAY...WITH WINDS LIKELY BECOMING
LOCALLY STRONG AND GUSTY BY AFTERNOON.
VICINITY OF KSFO...MOSTLY CLEAR SKIES THROUGH THE REMAINDER OF THE NIGHT
AND ALL DAY ON TUESDAY AS THE POST-FRONTAL AIR MASS REMAINS DRY
AND WELL MIXED. WINDS VEER NORTH-NORTHEASTERLY TOMORROW AND ARE
LIKELY TO BECOME STRONG AND GUSTY BY AFTERNOON. MEDIUM-TO-HIGH CONFIDENCE.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...VFR CONDITIONS WITH GENERALLY LIGHT
WINDS THROUGH THE PERIOD. MEDIUM CONFIDENCE.
&&
.MARINE...AS OF 01:38 PM PST MONDAY...STRONG HIGH PRESSURE WILL
BUILD OVER THE GREAT BASIN INCREASING NORTHERLY WINDS THROUGH
WEDNESDAY. WINDS DECREASE WEDNESDAY NIGHT AND THURSDAY AS THE HIGH
WEAKENS.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...SCA...PIGEON PT TO PT PINOS 0-10 NM
SCA...PIGEON PT TO PT PINOS 10-60 NM
SCA...PT PINOS TO PT PIEDRAS BLANCAS 10-60 NM
SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM UNTIL 3 AM
SCA...PT ARENA TO PT REYES 0-10 NM
SCA...PT ARENA TO PT REYES 10-60 NM
SCA...PT REYES TO PIGEON PT 0-10 NM
SCA...PT REYES TO PIGEON PT 10-60 NM
&&
$$
PUBLIC FORECAST: W PI
AVIATION/MARINE: BLIER
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AREA FORECAST DISCUSSION
NWS RENO NV
936 PM PST MON DEC 29 2014
.UPDATE...
JUST A FEW MINOR FORECAST TWEAKS THIS EVENING. WE ARE STILL ON
TRACK FOR A LIGHT SNOWFALL LATER TONIGHT. HOWEVER, THE INITIAL
BAND ASSOCIATED WITH SHALLOWER LIFT/MOISTURE HAS MOVED TO BETWEEN
RENO AND CARSON CITY AND IS NOT THE MAIN BAND OF SNOW FOR THE
AREA.
THE MAIN EVENT FOR THE RENO-SPARKS AND CARSON CITY-MINDEN AREAS
LOOKS TO BE LATER TONIGHT AS THE MAIN UPPER COLD POOL/TROUGH AXIS
APPROACHES. THIS IS EVIDENCED BY INCREASING RADAR RETURNS UP AROUND
PYRAMID LAKE AND COLDER CLOUD TOPS IN THE INFRARED SATELLITE NORTH
OF RENO. ALONG WITH A LIGHT SNOWFALL FOR MOST OF WESTERN NEVADA,
THE INSTABILITY AND DEEPER MOISTURE WITH THE COLD POOL SHOULD
COMBINE WITH UPSLOPE FLOW AGAINST THE CARSON RANGE TO PRODUCE
LOCALLY HIGHER SNOWFALL TOTALS IN THE FOOTHILLS SOUTH AND WEST OF
RENO. SNYDER
&&
.SYNOPSIS...
A STRONG COLD FRONT WILL PUSH THROUGH THE AREA TONIGHT. SNOWFALL IS
POSSIBLE WITH POTENTIAL TRAVEL IMPACTS FOR THE TUESDAY MORNING
COMMUTE ALONG THE HIGHWAY 395 CORRIDOR. STRONG WINDS ARE EXPECTED TO
PRODUCE ROUGH CONDITIONS ON AREA LAKES ALONG WITH POSSIBLE AREAS OF
BLOWING SNOW. TEMPERATURES WILL BE BITTER COLD WITH WIND CHILLS IN
THE SINGLE DIGITS AND NEGATIVE VALUES HEADING INTO THE NEW YEAR. A
MILDER PATTERN WILL RETURN FOR THE WEEKEND.
&&
.PREVIOUS DISCUSSION... /ISSUED 242 PM PST MON DEC 29 2014/
SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT
VISIBLE SATELLITE IMAGERY SHOWING A COLD UPPER LOW ACROSS THE
PACIFIC NORTHWEST WITH COOLING IR COLD TOPS ALONG A STRONG COLD
FRONT OVER SOUTHERN OREGON. THIS FRONT WILL QUICKLY DRIVE SOUTH
THROUGH NORTHERN NEVADA TONIGHT INTO TUESDAY MORNING PROVIDING THE
POTENTIAL FOR A FEW INCHES OF SNOWFALL AND BITTER COLD HEADING INTO
THE NEW YEAR.
HI-RES MESOSCALE AND GLOBAL MODELS ARE BEGINNING TO CLUE INTO THE
FORMATION OF BANDED SNOWFALL CREATED BY STRONG LOW LEVEL
FRONTOGENESIS AND MOISTURE IN A REGION OF FAVORABLE MICROPHYSICS FOR
ICE CRYSTAL GROWTH. THESE COLD TEMPERATURES WILL MAKE FOR LIGHT
AND FLUFFY SNOW. SOME DISAGREEMENT ON TIMING BUT LARGELY LOOKING
FOR SNOWFALL IN THE RENO/CARSON CITY REGION AS EARLY 8PM BUT THE
MOST FAVORABLE WINDOW LOOKS TO BE BETWEEN 10PM-4AM. A WINTER
WEATHER ADVISORY HAS BEEN POSTED FOR THE SIERRA FRONT WHICH
INCLUDES THE HWY 395 CORRIDOR SOUTH THROUGH MINDEN AND
GARDNERVILLE. THE ADVISORY ALSO COVERS PORTIONS OF WESTERN MINERAL
AND SOUTHERN LYON COUNTY. GENERALLY LOOKING FOR SNOWFALL IN THE
1-2" RANGE FROM RENO TO CARSON CITY WITH HIGHER AMOUNTS SOUTH
WHERE UPSLOPE FORCING WILL ADD ADDITIONAL LIFT. LOCATIONS ALONG
THE EASTERN SLOPES OF THE CARSON RANGE, EASTERN ALPINE CO,
NORTHERN MONO COUNTY COULD SEE MORE IN THE 2-4" RANGE. SLIDERS ARE
NOTORIOUSLY DIFFICULT SYSTEMS TO FORECAST SO WILL PUT FORECAST
CONFIDENCE IN SNOW AMOUNTS IN THE MEDIUM CATEGORY.
THE OTHER IMPACTS WITH THIS SYSTEM WILL BE SOME GUSTY CONDITIONS
BEHIND THE FRONT AS A STRONG PRESSURE GRADIENT DEVELOPS ACROSS
WESTERN NEVADA AND THE SIERRA. EXPECTING TO SEE SUSTAINED WINDS IN
THE 15-25 MPH RANGE WITH GUSTS UP TO 40-45 MPH OUT OF THE EAST WHICH
PUTS THIS JUST BELOW ADVISORY CRITERIA ACROSS WESTERN NEVADA. HAVE
HOWEVER POSTED A LAKE WIND ADVISORY FOR PYRAMID LAKE AND A WIND
ADVISORY ACROSS THE TAHOE BASIN. EXPECTING HAZARDOUS BOATING
CONDITIONS ON AREA LAKES WITH GUSTS NEAR 45 MPH EXPECTED IN THE
TAHOE BASIN WITH HIGHEST WAVES ALONG THE ATYPICAL WESTERN SHORES.
WINDS WILL SHARPLY INCREASE IN ELEVATION WITH VERY STRONG WINDS
EXPECTED MAINLY ABOVE 8,500 FEET WHERE GUSTS BETWEEN 80-100+ MPH ARE
POSSIBLE. THIS MAY ALSO POSE THE RISK FOR TREE FALLS ACROSS THE
TAHOE BASIN PARTICULARLY FOR TREES WEAKENED FROM THE PAST WIND
EVENT. THE SAME STRONG WINDS HOLD TRUE ACROSS HIGH TERRAIN THROUGH
MONO COUNTY BUT THE STRONGEST WINDS WILL REMAIN OVER THE CREST AND
ALONG THE WESTERN SLOPES OF THE SIERRA WHERE VERY STRONG DOWNSLOPE
WINDS LOOK FAVORABLE.
OTHERWISE, LOOKING FOR SNOW SHOWERS TO LINGER THROUGH TUESDAY
AFTERNOON ESPECIALLY ACROSS ALPINE AND MONO COUNTY WHERE UPSLOPE
FORCING SETS UP. AN INCH OR TWO IS POSSIBLE ACROSS THE TAHOE BASIN
AND MONO COUNTY OUTSIDE OF AREAS OF LAKE ENHANCED SNOWFALL. STRONG
WINDS MAY ALSO PRODUCE AREAS OF BLOWING SNOW AND REDUCED VISIBILITY.
FUENTES
(WEDNESDAY AND THURSDAY)..
MAIN CHANGE TO THE WEDNESDAY-THURSDAY TIME FRAME WAS LOWERING MAX
AND MIN TEMPS BY A FEW DEGREES EACH, WITH THE INCREASED
EXPECTATION OF ACCUMULATING SNOW WITH THE UPPER LOW PASSING
THROUGH TONIGHT AND TUESDAY. THE PRESENCE OF SNOW COVER WILL
STRENGTHEN THE VALLEY INVERSION FURTHER AND KEEP HIGHS ONLY IN THE
LOWER-MID 20S WEDNESDAY. STRONG NE-E WINDS WILL CONTINUE OVER THE
SIERRA RIDGES WITH GUSTS 75-85 MPH, WHILE SURFACE WIND GUSTS WILL
GENERALLY RANGE FROM 25-35 MPH EXCEPT NEAR 40 MPH AROUND TAHOE
WEDNESDAY MORNING. THESE WINDS WILL DECREASE LATER IN THE DAY AS
THE UPPER LOW MOVES FROM SOUTHEAST CA TO ARIZONA.
NEW YEARS EVE WILL BE QUITE COLD WITH TEMPERATURES BY MIDNIGHT
DROPPING TO THE LOWER TEENS FOR RENO-CARSON CITY AND SINGLE DIGITS
AROUND TAHOE. ALTHOUGH WINDS WILL BE DECREASING, WIND CHILLS COULD
STILL BE NEAR ZERO FOR WESTERN NV AND -10 DEGREES IN THE TAHOE BASIN
FOR THE FIRST COUPLE HOURS OF 2015. THE EARLY MORNING LOWS FOR NEW
YEARS DAY ARE LIKELY TO BE AROUND 5 DEGREES FOR URBAN AREAS OF
WESTERN NV, AND BELOW ZERO AWAY FROM THE MAIN CITIES AND IN THE
SIERRA VALLEYS.
ON THURSDAY, THE CORE OF THE COLD AIR MASS WILL MOVE AWAY FROM
WESTERN NV BUT WITH INVERSION STILL IN PLACE, HIGHS ARE LIKELY TO
REMAIN BELOW FREEZING. LIGHTER WINDS ARE EXPECTED WITH DRY
CONDITIONS PREVAILING THROUGH THE FIRST DAY OF 2015. MJD
LONG TERM (FRIDAY-MONDAY)...
THE MOTTO FOR THE LONG TERM WILL BE "WELCOME TO INVERSION CITY".
GUIDANCE CONSENSUS SHOWS RIDGING JUST OFF THE WEST COAST THROUGH THE
WEEKEND WHICH YIELDS WARMING TEMPERATURES AT 700MB. COUPLED WITH A
SURFACE HIGH OVER THE INTERMOUNTAIN WEST THIS RESULTS IN AN
INVERSION PATTERN FOR THE VALLEYS OF WESTERN NV AND NORTHEAST CA,
WITH LIGHT WINDS, LIMITED MIXING, AND POTENTIAL AIR POLLUTION
BUILDUPS. TEMPERATURES IN VALLEYS WILL WARM EACH DAY BUT AT A MUCH
SLOWER RATE COMPARED TO THE MOUNTAINS. IF WE GET SUFFICIENT SNOWFALL
TONIGHT THEN THOSE INVERSIONS COULD BE STRONGER WITH POTENTIAL FOR
SPOTS OF FREEZING FOG IN NORMALLY PRONE AREAS.
UNFORTUNATELY I`M REALLY NOT SEEING MEANINGFUL STORM POTENTIAL
THROUGH AT LEAST MONDAY AS THE RIDGE BLOCKS PACIFIC STORMS FROM
IMPACTING CA/NV. THERE ARE SOME SIGNS OF THE RIDGE BREAKING DOWN OR
BEING UNDERCUT MID/LATE NEXT WEEK ALLOWING AN INCREASED CHANCE OF
ATMOSPHERIC RIVERS LANDFALLING ON THE WEST COAST. BUT OF COURSE
PREDICTABILITY OF THESE PATTERN CHANGES 7-10 DAYS OUT IS QUITE
LIMITED. CS
AVIATION...
FORECAST CONFIDENCE IN TODAY`S TAFS IS MEDIUM, WITH UNCERTAINTIES IN
TIMING AND INTENSITY OF TONIGHT`S BAND OF SNOW. THESE KIND OF SLIDER
STORMS ARE A CHALLENGE TO PREDICT SO SNOWFALL POTENTIAL REMAINS ONLY
MEDIUM CONFIDENCE AS WELL. HIGH RESOLUTION SIMULATIONS (HRRR) ARE
SHOWING A FAST MOVING BAND OF -SN DEVELOPING FROM AAT-LOL AROUND
SUNDOWN AND THEN DROPPING SOUTHWARD INTO RNO/CXP 4-10Z, TRK/TVL/MEV
AROUND 6-12Z, AND AFTER 12Z AT MMH. IN SUCH A STRONGLY FORCED
SITUATION THE HRRR USUALLY DOES REASONABLY WELL SO WE`LL FOLLOW FOR
THE TAFS.
PERIODS OF MVFR/IFR -SN LIKELY AT RNO/CXP/TRK/TVL/MEV TONIGHT
YIELDING UP TO 2 INCHES OF FLUFFY SNOW. THERE`S ABOUT A 20% CHANCE
WE COULD SEE BRIEF PERIODS OF HEAVIER SNOW, 1/2SM VISIBILITY TYPE
STUFF, BUT PREDICTING TIMING ON THAT IS TRICKY. GUSTY N/NE WINDS
WILL RESULTING IN BLOWING SNOW AS WELL. CLOUDS WILL RESULT IN
TERRAIN OBSCURATION TONIGHT THROUGH TOMORROW.
THE POST-FRONTAL NORTHEAST WINDS TUESDAY WILL BE PRONOUNCED AND
GUSTY, WITH A FRESH SUSTAINED 15-25 KTS EAST/NORTHEAST WIND WITH
GUSTS 25-30 KTS. CXP WHICH IS PRONE TO NE FLOW EVENTS, WILL LIKELY
SEE PERIODS OF STRONGER SUSTAINED WINDS. RIDGE LEVEL GUSTS OF 60-70
KTS FORECAST TOMORROW, INCREASING TUESDAY NIGHT INTO WEDNESDAY. DUE
TO THE UNUSUAL NE WIND DIRECTION, THAT WILL LEAD TO TURBULENCE
ESPECIALLY WEST OF ANY MOUNTAINS DUE TO MOUNTAIN WAVE ACTIVITY. CS
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...LAKE WIND ADVISORY FROM 7 AM TO 7 PM PST TUESDAY FOR PYRAMID
LAKE IN NVZ004.
WIND ADVISORY FROM 7 AM TUESDAY TO 4 AM PST WEDNESDAY NVZ002.
WINTER WEATHER ADVISORY UNTIL 4 PM PST TUESDAY NVZ001.
WINTER WEATHER ADVISORY UNTIL 10 AM PST TUESDAY NVZ003.
CA...WIND ADVISORY FROM 7 AM TUESDAY TO 4 AM PST WEDNESDAY CAZ072.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
919 PM PST MON DEC 29 2014
...WINDY AND COLDER WEATHER ON THE WAY FOR THE END OF 2014...
.SYNOPSIS...A FAST MOVING STORM SYSTEM WILL MOVE SOUTHEAST ACROSS
NEVADA TONIGHT BRINGING A SLIGHT CHANCE OF SHOWERS MAINLY IN THE HILLS.
COLDER AND WINDIER CONDITIONS WILL SETTLE OVER THE AREA TUESDAY AND
WEDNESDAY BEHIND THIS SYSTEM. A WARMING TREND WILL RETURN BY LATE
THIS WEEK.
&&
.DISCUSSION...AS OF 9:00 PM PST MONDAY...A COLD UPPER LEVEL LOW
OVER SOUTHEAST OREGON WILL DRIVE SOUTHEAST DURING THE NIGHT WITH THE
TROUGH AXIS MOVING THROUGH THE AREA LATE TONIGHT. THE SYSTEM HAS
VERY LITTLE MOISTURE BUT RECENT HRRR MODEL RUNS HAVE SHOWN
ISOLATED CONTOURS OF ONE TO TWO-HUNDREDTHS OF PRECIP IN THE HILLS.
A SLIGHT CHANCE OF SHOWERS IS IN THE FORECAST FOR TONIGHT BUT MOST
LIKELY ANY PRECIP WILL FALL OVER THE HILLS.
WINDS WILL INCREASE AS THIS TROUGH AXIS MOVES THROUGH WITH MODELS
SHOWING 925 MB WINDS INCREASING TO 35-45 KT RANGE TUESDAY MORNING.
MODELS ALSO SHOW DECENT OMEGA VALUES AFTER THE TROUGH PASSES
INDICATING THAT WINDS ALOFT COULD MIX DOWN TO THE SURFACE.
THEREFORE A WIND ADVISORY IS IN EFFECT BEGINNING TUESDAY MORNING
IN THE NORTH AND EAST BAY HILLS AND SANTA CRUZ MOUNTAINS FOR GUSTS
UP TO 55-60 MPH...AND MIDDAY TUESDAY FOR THE REST OF THE SFO BAY
AREA WITH GUSTS TO 40-45 MPH. STRONG WINDS WILL CONTINUE THROUGH
TUESDAY NIGHT AND MAY EVEN BE SLIGHTLY STRONGER THAN TUESDAY
MORNING. THESE STRONG WINDS WILL BRING DOWN SOME TREES AND CAUSE
POWER OUTAGES AS THE SOIL REMAINS FAIRLY WET FROM RAINS EARLIER
THIS MONTH.
WINDS WILL DECREASE BY MIDDAY WEDNESDAY AS THE LOW MOVES FURTHER
EAST AND AN UPPER LEVEL RIDGE BUILDS IN FROM THE WEST. COLD
NORTHERLY FLOW WILL CONTINUE OVER THE AREA THROUGH WEDNESDAY AND
WITH THE WINDS DIMINISHING IT WILL SET UP A COLD NIGHT FOR NEW
YEARS EVE. TEMPERATURES WILL DROP INTO THE 20S IN MANY OF THE
INLAND VALLEYS WITH LOWER TO MID 30S IN THE URBAN AREAS AROUND
OAKLAND-SAN JOSE. A FROST ADVISORY MAY BE NEEDED FOR MOST OF THE
SFO BAY AREA WEDNESDAY NIGHT.
TEMPERATURES WILL SLOWLY WARM UP THURSDAY THROUGH SUNDAY AS THE
UPPER LEVEL RIDGE MOVES OVER THE WEST COAST. IN THE LONG
RANGE...MODELS CONTINUE TO STRUGGLE WITH WHETHER THERE WILL BE
RAIN IN OUR CWA AROUND THE MIDDLE OF NEXT WEEK. LATEST GFS AND
ECMWF INDICATE A CHANCE FOR RAIN FOR AT LEAST THE NORTHERN PART OF
THE DISTRICT.
&&
.AVIATION...AS OF 4:45 PM PST MONDAY...PATCHES OF LOW AND MID
LEVEL CLOUDINESS REMAIN OVER PORTIONS OF THE DISTRICT BUT WITH ALL
TERMINALS NOW REPORTING VFR CONDITIONS. THESE SHOULD CONTINUE THROUGH
THE NIGHT AS THE BOUNDARY LAYER AIR MASS LOOKS TO REMAIN
SUFFICIENTLY DRY AND WELL MIXED AS TO PRECLUDE DEVELOPMENT OF EITHER
FOG OR CIGS.
THE PASSAGE OF A STRONG BUT DRY UPPER LEVEL DISTURBANCE FROM THE
NORTH TONIGHT...IN CONJUNCTION WITH DEVELOPMENT OF A STRONG NE TO SW
ORIENTED SEA LEVEL PRESSURE GRADIENT...WILL RESULT IN INCREASINGLY
STRONG NORTH TO NORTHEASTERLY FLOW ALOFT OVER THE AREA. KEY
QUESTIONS ARE WHEN...WHERE...AND TO WHAT DEGREE THESE WINDS MIX
DOWN TO THE SURFACE. HIGH RESOLUTION LOCAL MODEL OUTPUT INDICATES
THIS WILL PROGRESSIVELY OCCUR AT SFO BAY AREA TAF SITES DURING THE
DAY ON TUESDAY...WITH WINDS POTENTIALLY BECOMING LOCALLY STRONG
AND GUSTY BY AFTERNOON.
VICINITY OF KSFO...NO MORE THAN SCATTERED CLOUDINESS IS EXPECTED
OVERNIGHT AND TUESDAY MORNING AS THE AIR MASS REMAINS DRY AND
WELL MIXED. WINDS VEER NORTH-NORTHEASTERLY TOMORROW AND ARE
LIKELY TO BECOME STRONG AND GUSTY BY AFTERNOON. MEDIUM CONFIDENCE.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...VFR CONDITIONS WITH GENERALLY LIGHT
WINDS THROUGH THE PERIOD. MEDIUM CONFIDENCE.
&&
.MARINE...AS OF 01:38 PM PST MONDAY...STRONG HIGH PRESSURE WILL
BUILD OVER THE GREAT BASIN INCREASING NORTHERLY WINDS THROUGH
WEDNESDAY. WINDS DECREASE WEDNESDAY NIGHT AND THURSDAY AS THE HIGH
WEAKENS.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...SCA...PT PINOS TO PT PIEDRAS BLANCAS 10-60 NM
SCA...PT REYES TO PIGEON PT 0-10 NM
SCA...PT REYES TO PIGEON PT 10-60 NM
SCA...PT ARENA TO PT REYES 0-10 NM
SCA...PT ARENA TO PT REYES 10-60 NM
SCA...PIGEON PT TO PT PINOS 10-60 NM
SCA...PT REYES TO PIGEON PT 0-10 NM
SCA...PIGEON PT TO PT PINOS 0-10 NM
&&
$$
PUBLIC FORECAST: W PI
AVIATION: BLIER
MARINE: AC
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AREA FORECAST DISCUSSION
NWS CHARLESTON SC
409 AM EST TUE DEC 30 2014
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE AREA TODAY INTO FRIDAY...BEFORE
MOVING INTO THE ATLANTIC BY SATURDAY. A COASTAL TROUGH WILL DEVELOP
SATURDAY AND LIFT NORTH OF THE REGION BY SUNDAY. A COLD FRONT WILL
THEN PASS OFF THE COAST EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
THROUGH SUNRISE...STRATUS BUILD DOWN IS IN PROGRESS WITH BKN-OVC
CLOUDY LAYERS OF 100-300 FT BEGINNING TO LOWER TO THE SURFACE.
ALREADY SEEING A FEW SITES WITH VISIBILITIES LESS THAN 1/2 MILE AND
TRENDS ARE BEING WATCHED FOR THE DEVELOPMENT OF DENSE FOG. VSBYS
AND WEBCAMS IN THE BEAUFORT AND SAVANNAH AREAS INDICATE THE FOG IS
QUICKLY BECOMING DENSE AND WIDESPREAD ENOUGH FOR A DENSE FOG
ADVISORY. AN ADVISORY HAS BE ISSUED FOR COASTAL COLLETON-BEAUFORT-
INLAND JASPER-COASTAL JASPER-INLAND CHATHAM AND COASTAL CHATHAM
UNTIL 9 AM. IT IS UNCLEAR HOW WIDESPREAD THE DENSE FOG WILL BECOME
ELSEWHERE...ESPECIALLY GIVEN WINDS ARE AVERAGING 5-10 MPH...BUT
THE ADVISORY WILL BE ADJUSTED TEMPORALLY OR SPATIALLY AS NEEDED.
TODAY...LOW CONFIDENCE FORECAST TODAY. THE COLD FRONT AND
ASSOCIATED FRONTAL WAVE ARE NOW WELL OFFSHORE WITH A NORTHERLY
LOW-LEVEL FLOW DOMINATING IN ITS WAKE. A WEAK POST FRONTAL SURFACE
TROUGH DELINEATING A SURGE OF COOLER AIR WILL APPROACH THE
CHARLESTON AREA BY SUNRISE...THE SAVANNAH AREA BY MID-MORNING AND
FINALLY CLEARING THE ALTAMAHA RIVER BY LATE AFTERNOON. MODELS SHOW
A TRANSIENT HYBRID WEDGE SETTING UP ACROSS MAINLY THE CENTRAL AND
NORTHERN PORTIONS OF THE FORECAST AREA IN THE WAKE OF THE TROUGH
AS 290K ISENTROPIC ASSENT BRIEFLY INTENSIFIES ATOP THE LOW-LEVEL
POST FRONTAL WEDGING PATTERN. THIS PATTERN WILL ESSENTIALLY
REINFORCE THE WIDESPREAD LOW CLOUDS AND PATCHY DRIZZLE THAT ARE
ALREADY IN PLACE ACROSS THE LOWCOUNTRY AND COASTAL EMPIRE FOR A
GOOD PORTION OF THE DAY. THE TEMPERATURE FORECAST IS PROVING TO BE
EXTREMELY CHALLENGING AS A RESULT AND ASSUMES THE TRANSIENT WEDGE
ACTUALLY DEVELOPS AS DEPICTED IN THE HIGHER RESOLUTION DATA SETS.
DAILY HIGHS /7AM-6PM/ WILL LIKELY OCCUR BY MID-MORNING ACROSS THE
CHARLESTON TRI-COUNTY AREA AND EARLY AFTERNOON ACROSS THE
REMAINDER OF SOUTHEAST SOUTH CAROLINA AND SOUTHEAST GEORGIA.
TEMPERATURES WILL LIKELY HOLD STEADY OR SLOWLY FALL NORTH THE
SAVANNAH RIVER AS THE WEDGE BRIEFING INTENSIFIES. HIGHS WILL RANGE
MID 50S NORTH...UPPER 50/NEAR 60 CENTRAL TO THE LOWER-MID 60S
SOUTH. UTILIZE A 30/30/30 BLEND OF RAP/H3R AND GLAMP DATA TO
CONSTRUCT HOURLY TEMPERATURES. SINCE THIS IS A VERY LOW CONFIDENCE
FORECAST...CHANGES--SOME POSSIBLY SIGNIFICANT--WILL LIKELY BE
NEEDED THROUGHOUT THE DAY.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY/...
TONIGHT...THE TRANSIENT HYBRID WEDGE WILL QUICKLY BREAKDOWN THIS
EVENING AS HIGH PRESSURE FINALLY BRIDGES THE SOUTHERN APPALACHIANS
AND BECOMES MORE DOMINATE ACROSS THE SOUTHEAST STATES. A GOOD BIT
OF CLOUD COVER WILL LINGER THROUGH THE NIGHT WITH THE POTENTIAL
FOR SOME CLEARING TO OCCUR ACROSS THE NORTH AFTER 3 AM. WILL HAVE
TO WATCH FOR SOME FOG TO DEVELOP AFTER MIDNIGHT...BUT THIS DOES
NOT LOOK SIGNIFICANT AT THIS TIME. LOWS WILL RANGE FROM THE MID-
UPPER 30S INTERIOR NORTH WHERE THE BETTER CHANCES FOR CLEARING
WILL OCCUR WITH UPPER 30S TO LOWER 40S ELSEWHERE...EXCEPT MID 40S
ALONG THE GEORGIA COAST WHERE ONSHORE WINDS WILL MODERATE
TEMPERATURES A BIT.
WEDNESDAY AND THURSDAY...EXPANSIVE SURFACE HIGH PRESSURE WILL
BE GRADUALLY WEAKENING AS IT SLIPS TOWARD THE EAST COAST UNDER
RELATIVELY ZONAL FLOW ALOFT. EXPECT DRY CONDITIONS TO PREVAIL
WEDNESDAY AND THURSDAY WITHIN THIS PATTERN. TEMPERATURES
WEDNESDAY WILL BE A FEW DEGREES COOLER THAN NORMAL...PEAKING IN THE
MID TO UPPER 50S DURING THE AFTERNOON AND FALLING INTO THE LOW 30S
NORTH TO UPPER 30S COAST AND SOUTH OVERNIGHT. NORTH FLOW WEAKENS
ON THURSDAY AS THE CENTER OF THE SURFACE HIGH PASSES DIRECTLY OVER
THE REGION...AND WITH SUBTLE RIDGING BUILDING UP FROM THE
BAHAMAS...HIGH TEMPERATURES WILL MODERATE TOWARD SEASONAL NORMALS
IN THE UPPER 50S TO LOWER 60S. A GRADUALLY IMPROVING TAP INTO GULF
MOISTURE LATE THURSDAY WILL SUPPORT INCREASING CLOUDS...WITH LOW
TEMPERATURES A FEW DEGREES MILDER IN THE UPPER 30S INLAND TO LOW
40S CLOSER TO THE COAST.
FRIDAY...AN UPPER LEVEL CUT OFF LOW WILL MOVE FROM THE SOUTHWEST
STATES INTO THE SOUTHERN PLAINS...PROVIDING THE ENERGY TO DEVELOP
A WAVE OF LOW PRESSURE ACROSS THE WESTERN GULF LATE IN THE DAY.
THE SOUTHEAST STATES WILL REMAIN ON THE PERIPHERY OF ATLANTIC HIGH
PRESSURE...WHERE SHORTWAVE ENERGY TRACKING UP FROM THE GULF OF
MEXICO WILL SUPPORT THE GRADUAL AMPLIFICATION OF A COASTAL TROUGH.
NUMERICAL MODEL SOLUTIONS ARE INDICATING SUFFICIENT ISENTROPIC
ASCENT BETWEEN THE COASTAL TROUGH AND A DEVELOPING INLAND WEDGE
TO GENERATE ISOLATED TO SCATTERED RAIN...WITH BEST COVERAGE
ACROSS NORTHERN AND INLAND AREAS. TEMPERATURES COULD BE A DEGREE
OR TWO COOLER THAN THE PREVIOUS DAY GIVEN THE INCREASING CLOUD
COVER...YET STILL RANGE NEAR SEASONAL NORMALS IN THE UPPER 50S TO
LOW 60S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
FRIDAY NIGHT THROUGH SUNDAY...A TRANSIENT INLAND WEDGE/COASTAL
TROUGH PATTERN WILL BE IN PLACE THROUGH EARLY SATURDAY...BEFORE
THE COASTAL TROUGH QUICKLY LIFTS NORTH OF THE REGION AHEAD OF AN
APPROACHING COLD FRONT FROM THE WEST. THE CUT OFF LOW ACROSS THE
SOUTHERN PLAINS WILL DAMPEN AND LIFT NORTHEAST INTO THE OHIO
VALLEY ON SATURDAY. THE ASSOCIATED SURFACE LOW WILL PULL INTO THE
NEW ENGLAND STATES SUNDAY...WITH ITS TRAILING COLD FRONT
PROGRESSING THROUGH THE MID ATLANTIC AND SOUTHEAST STATES BY
SUNDAY AFTERNOON. HIGH TEMPERATURES WILL SURGE INTO THE 60S TO
AROUND 70 DEGREES SATURDAY AND SUNDAY WITHIN WARM SOUTHERLY FLOW
AHEAD OF THE FRONT...WHILE SCATTERED SHOWERS ARE POSSIBLE SATURDAY
THROUGH SUNDAY AFTERNOON. PREFER TO REMAIN RATHER CONSERVATIVE
WITH RAIN CHANCES AT THIS POINT...CONSIDERING THE SOUTHERN END OF
THE FRONT WILL RUN INTO THE PERIPHERY OF THE SUBTROPICAL RIDGE AND
BECOME PARALLEL TO FLOW ALOFT.
SUNDAY NIGHT THROUGH TUESDAY...SURFACE HIGH PRESSURE WILL BUILD IN
THE WAKE OF THE DEPARTING COLD FRONT EARLY NEXT WEEK...EVENTUALLY
SETTLING TO THE NORTH OF THE AREA. RAIN FREE CONDITIONS WILL
PREVAIL. TEMPERATURES ARE EXPECTED TO RETURN TO SEASONAL
NORMALS...POSSIBLY COOLER IF A WEDGE PATTERN CAN SET UP TOWARD THE
END OF THE FORECAST PERIOD.
&&
.AVIATION /07Z TUESDAY THROUGH SATURDAY/...
LIFR CIGS WILL LINGER AT BOTH TERMINALS THROUGH SUNRISE. CIGS WILL
REMAIN BELOW ALTERNATE MINIMUMS AND COULD DROP BELOW AIRPORT
MINIMUMS OVER THE NEXT FEW HOURS. FOG COULD BECOME A PROBLEM
LATE...BUT THE LOW CIGS WILL BE THE PRIMARY ISSUE UNLESS THE
STRATUS DECKS REACH THE GROUND RESULTING IN DENSE FOG. LOW
CONFIDENCE IN THIS SCENARIO RIGHT NOW. CIGS WILL LIFT EVER SO
SLOWLY AFTER SUNRISE...BUT SHOULD RISE ABOVE ALTERNATE MINIMUMS
13-14Z...ALTHOUGH STAYING IN IFR. MVFR SHOULD RETURN BY 16-17Z AND
LINGER THE REST OF THE 06Z TAF PERIOD.
EXTENDED AVIATION OUTLOOK...VFR CONDITIONS WILL PREVAIL WEDNESDAY
AND THURSDAY. CHANCES FOR FLIGHT RESTRICTIONS INCREASE INTO THE
WEEKEND AS THE NEXT SYSTEM IMPACTS THE REGION.
&&
.MARINE...
TODAY...CEILINGS OF 100 FT AT THE HILTON HEAD AIRPORT AND WEBCAMS
IN THE SAVANNAH RIVER AS WELL AS TYBEE ISLAND SUGGEST SEA FOG IS
IN PLACE ACROSS THE COASTAL WATERS THIS MORNING. IT IS UNCLEAR
EXACTLY HOW WIDESPREAD THE FOG IS...BUT RAP VISIBILITIES DATA
SUGGEST ITS PROBABLY PRETTY WIDESPREAD. WFO JAX RECENTLY RELAYED
THAT THE BAR PILOTS OUT OF SAINT SIMMONS ARE REPORTING IMPROVED
VSBYS OVER THE PAST HOUR...BUT THE SHELF WATERS OFF TYBEE ISLAND
ARE SEVERAL DEGREES COOLER. PREFER TO HOLD THE MARINE DENSE FOG
ADVISORY FOR THE GEORGIA NEARSHORE AND BEAUFORT COUNTY WATERS
UNTIL 8 AM...OR AT LEAST UNTIL CONDITIONS CAN BE BETTER EVALUATED
ON COASTAL WEBCAMS AS THE SUN RISES. OTHERWISE...NORTH WINDS WILL
INCREASE TO 10-15 KT TODAY WITH SEAS 1-3 FT.
TONIGHT...WINDS WILL INCREASE A BIT AS THE PRESSURE GRADIENT
INDUCED BY HIGH PRESSURE BUILDING IN FROM THE WEST TIGHTENS.
EXPECT WINDS OF 15-20 KT WITH SEAS 2-3 FT NEARSHORE...4-5 FT
OFFSHORE.
WEDNESDAY THROUGH SATURDAY...THE PRESSURE GRADIENT WILL REMAIN
RELATIVELY TIGHT INTO WEDNESDAY MORNING ON THE PERIPHERY OF HIGH
PRESSURE BUILDING FROM THE WEST. MARGINAL SMALL CRAFT ADVISORY
WINDS IN GUSTS TO 25 KT COULD LINGER ACROSS THE OFFSHORE GEORGIA
WATERS...BEFORE CONDITIONS SLOWLY IMPROVE AS THE DAY PROGRESSES.
THE SURFACE HIGH WILL THEN STEADILY TRACK EAST AND ALLOW THE
GRADIENT TO RELAX TOWARD THE END OF THE WEEK. A COASTAL TROUGH
WILL DEVELOP LATE FRIDAY INTO SATURDAY...WITH INCREASING SOUTHERLY
FLOW IN IT WAKE.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR GAZ118-119.
SC...DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR SCZ047>049-
051.
MARINE...DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR AMZ352-354.
&&
$$
ST/WMS
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
129 AM EST TUE DEC 30 2014
.SYNOPSIS...
A COLD FRONT WILL MOVE SOUTHEAST INTO THE ATLANTIC EARLY TONIGHT AND
PUSH FURTHER OFFSHORE OVERNIGHT. HIGH PRESSURE WILL BUILD INTO THE
AREA TUESDAY INTO FRIDAY...BEFORE MOVING INTO THE ATLANTIC BY
SATURDAY. A COASTAL TROUGH WILL DEVELOP EARLY THIS WEEKEND THEN
LIFT NORTH OF THE REGION ON SUNDAY. A COLD FRONT WILL THEN PASS
OFF THE COAST EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
WEAK COLD FRONT HAS CLEARED THE GEORGIA COAST WITH A PRONOUNCED
POST-FRONTAL SURFACE TROUGH DROPPING SOUTH. THE TROUGH HAS PASSED
THE CHARLESTON AIRPORT AND WILL CONTINUE TO MOVE SLOWLY SOUTH
THROUGH SUNRISE. LOW STRATUS AND EVENTUALLY FOG WILL AFFECT THE
REGION OVERNIGHT WITH OCCASIONAL LIGHT DRIZZLE. SKIES HAVE CLEARED
BRIEFLY ACROSS ALLENDALE COUNTY AND DENSE RADIATION FOG HAS
QUICKLY DEVELOPED. ITS UNCLEAR HOW LONG THE DENSE FOG WILL
LAST...BUT IT MAY BE ANOTHER 1-2 HOURS BEFORE LOW CLOUDS FILL IN
FROM THE NORTH. IN FACT...CLEARING AND DENSE FOG COULD OCCUR
ACROSS MUCH OF THE FAR WESTERN ZONES FOR THE NEXT FEW HOURS. WILL
WATCH TRENDS CAREFULLY. OTHERWISE...DRIZZLE AND EXTENSIVE CLOUD
COVER WILL PERSIST. IT IS UNCLEAR HOW STRONG POST-FRONTAL STRATUS
BUILD DOWN WILL BE...BUT THERE IS A POTENTIAL FOR SOME DENSE FOG.
MADE ADJUSTMENTS TO CLOUD COVER...FOG COVERAGE AND INTRODUCED
AREAS OF DRIZZLE INTO THE FORECAST FOR THE MIDNIGHT UPDATE. THE
REST OF THE FORECAST IS OKAY.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY/...
TUESDAY AND TUESDAY NIGHT...NEARLY ZONAL FLOW WILL PREVAIL ALOFT AS
A COLD FRONT SLIPS OFF SHORE. BACK TO THE WEST...CONFLUENT FLOW
ALOFT WILL HELP TO FORCE AN IMPRESSIVE 1058 MB HIGH OVER THE
NORTHERN ROCKIES THAT WILL BUILD INTO THE FORECAST AREA THROUGH THE
DAY. FOLLOWING LOW LEVEL THETA E FIELDS...THE LEADING EDGE OF THE
COOLER AIR BEHIND THE FRONT AND THE EXTENT OF THE STRONG SURFACE
HIGH WILL NOT OOZE INTO THE AREA UNTIL LATER IN THE DAY ON TUESDAY
AND POSSIBLY EVEN INTO THE EVENING. AHEAD OF THIS THETA E
GRADIENT...RESIDUAL MOISTURE IN THE LOWEST 3-4K FT OF THE
ATMOSPHERE SHOWS UP WELL IN MODEL TIME HEIGHTS AND CROSS SECTIONS.
THIS SHOULD MANIFEST ITSELF IN THE FORM OF EXTENSIVE STRATUS
ACROSS THE FORECAST AREA FOR MUCH OF THE DAY. IN FACT...WE MAY NOT
SEE ANY CLEARING IN THE TRI-COUNTY REGION UNTIL LATE IN THE
AFTERNOON. THIS WILL HELP KEEP TEMPERATURES AT BAY DESPITE THE
LATER ARRIVAL OF THE COOLER AIR. LOOK FOR HIGHS IN THE MID/UPPER
50S FURTHER NORTH...AND LOW 60S FURTHER TO THE SOUTH. SOME OF THE
MODELS ARE WRINGING OUT SOME MEASURABLE PRECIPITATION IN THE
MORNING DESPITE THE LACK OF FORCING AND RELATIVELY SHALLOW MOIST
LAYER. HAVE KEPT THE FORECAST DRY. OVERNIGHT...COOL NORTHERLY FLOW
WILL SETTLE IN AS THE LOW LEVELS START TO DRY OUT. THE FORECAST IS
DRY AND FEATURES LOWS FALLING INTO THE UPPER 30S NORTH...LOW 40S
FURTHER SOUTH FOR COASTAL SOUTHEAST GEORGIA.
WEDNESDAY THROUGH THURSDAY...ZONAL FLOW WILL PREVAIL ALOFT AS
EXPANSIVE BUT WEAKENING HIGH PRESSURE BUILDS IN FROM THE WEST. WE
MAY BE DEALING WITH A DECENT AMOUNT OF JET-INDUCED HIGH CLOUDS ON
WEDNESDAY...BUT A COLUMN THAT IS OVERALL VERY DRY WILL KEEP THE
FORECAST RAIN FREE THROUGH THURSDAY. TEMPERATURES WILL BE ON THE
COOL SIDE WEDNESDAY...RUNNING ABOUT 4 DEGREES BELOW NORMAL...THEN
RIGHT AROUND NORMAL ON THURSDAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
THE EXPANSIVE SURFACE HIGH WILL STEADILY SHIFT OVER GEORGIA AND
THE CAROLINAS BY FRIDAY...BEFORE MOVING INTO THE ATLANTIC WATERS
SATURDAY. A STRONG CUT OFF LOW OVER THE DESERT SOUTHWEST FRIDAY WILL
EJECT INTO THE SOUTHERN PLAINS OVER THE WEEKEND AND THEN DAMPEN
AS IT MOVE INTO THE UPPER GULF COAST REGION BY LATE WEEKEND. CLOUDS
WILL BE ON THE INCREASE THURSDAY NIGHT AS A SHORT WAVES TRAVERSES
INTO THE REGION ATOP A LARGE SUBTROPICAL RIDGE OVER FLORIDA AND
THE CARIBBEAN. THIS DISTURBANCE MAY PRODUCE SOME SPOTTY LIGHT RAINS
ON FRIDAY BUT CERTAINLY NOT SIGNIFICANT AS PRECIP IS LIKELY TO
EVAPORATE IN DRY LAYERS BELOW 10 KFT. A SLIGHT CHANCE POP LOOKS QUITE
SUFFICIENT. STEADIER RAINS ACROSS NORTH GEORGIA AND THE WESTERN
CAROLINAS MAY BEGIN TO ANCHOR A WEDGE ON SATURDAY WITH GLOBAL
MODELS DIFFERING ON SURFACE PATTERNS. THE WEEKEND LOOKS A BIT
UNSETTLED WITH PLENTY OF CLOUDS MOST AREAS AND MAINLY LOW END CHANCE
POPS AS THE UPPER WAVE FLATTENS SIGNIFICANTLY LATE IN THE WEEKEND.
SUNDAY APPEARS TO BE THE WARMER OF THE DAYS AFTER WE TRENDED DOWN A
GOOD BIT ON TEMPS NORTHERN ZONES SATURDAY. A COLD FRONT SHOULD MOVE
OFF THE COAST EARLY NEXT WEEK.
&&
.AVIATION /07Z TUESDAY THROUGH SATURDAY/...
LIFR CIGS WILL LINGER AT BOTH TERMINALS THROUGH SUNRISE. CIGS WILL
REMAIN BELOW ALTERNATE MINIMUMS AND COULD DROP BELOW AIRPORT
MINIMUMS OVER THE NEXT FEW HOURS. FOG COULD BECOME A PROBLEM
LATE...BUT THE LOW CIGS WILL BE THE PRIMARY ISSUE UNLESS THE
STRATUS DECKS REACH THE GROUND RESULTING IN DENSE FOG. LOW
CONFIDENCE IN THIS SCENARIO RIGHT NOW. CIGS WILL LIFT EVER SO
SLOWLY AFTER SUNRISE...BUT SHOULD RISE ABOVE ALTERNATE MINIMUMS
13-14Z...ALTHOUGH STAYING IN IFR. MVFR SHOULD RETURN BY 16-17Z AND
LINGER THE REST OF THE 06Z TAF PERIOD.
EXTENDED AVIATION OUTLOOK...LOW CEILINGS TO CLEAR OUT TUESDAY
NIGHT...IF NOT BEFORE. VFR CONDITIONS WILL THEN PREVAIL THROUGH AT
LEAST THURSDAY. CHANCES FOR FLIGHT RESTRICTIONS INCREASE INTO THE
WEEKEND AS THE NEXT SYSTEM IMPACTS THE REGION.
&&
.MARINE...
TONIGHT...CEILINGS AT HILTON HEAD HAVE DROPPED TO 100 FT...
SUGGESTING DENSE FOG IN OCCURRING JUST OFFSHORE. EXPANDED THE
MARINE DENSE FOG ADVISORY NORTH TO INCLUDE THE BEAUFORT COUNTY
WATERS. WEBCAMS OUT OF TYBEE ISLAND AND EARLIER REPORTS FROM THE
SAINT SIMMONS BAR PILOT BOAT PROVIDE ENOUGH DATA TO SUPPORT A
MARINE DENSE FOG ADVISORY FOR THE GEORGIA NEARSHORE WATERS THROUGH
6 AM. RAP VSBY PROGS APPEAR TO CAPTURE THE SEA FOG WELL AND WAS
USED TO CONSTRUCT WEATHER AND VSBY GRIDS THROUGH 6 AM.
TUESDAY THROUGH SATURDAY...A COLD FRONT WILL PUSH WELL OFFSHORE
TUESDAY AS HIGH PRESSURE WILL BEGIN TO BUILD IN TUESDAY NIGHT. AS
THE HIGH BUILDS IN A NOTABLE NORTHERLY SURGE WILL TAKE PLACE TUESDAY
NIGHT AND INTO WEDNESDAY MORNING. A SOLID 15-20 KT OF WIND IS
EXPECTED WITHIN 20 NM WITH SOME GUSTS TO 25 KT POSSIBLE. WINDS WILL
BE CLOSER TO 20-25 KT FOR THE OUTER GEORGIA WATERS WITH SOME 6 FT
SEAS POSSIBLE. SMALL CRAFT ADVISORIES MAY BE NEEDED...ESPECIALLY FOR
THE OUTER GEORGIA WATERS TUESDAY NIGHT. THEREAFTER...HIGH PRESSURE
WILL BE THE PRIMARY WEATHER FEATURE THOUGH THE GRADIENT WILL RELAX.
IT IS STILL A BIT TOO EARLY TO COMMIT ON STRENGTH OF THE WEDGE THIS
WEEKEND AND TIMING THE WARM FRONT THROUGH...BUT COMPLEX LOW LEVEL
MIXING ENVIRONMENTS ARE LIKELY.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
AMZ352-354.
&&
$$
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
1240 AM EST TUE DEC 30 2014
.SYNOPSIS...
A COLD FRONT WILL MOVE SOUTHEAST INTO THE ATLANTIC EARLY TONIGHT AND
PUSH FURTHER OFFSHORE OVERNIGHT. HIGH PRESSURE WILL BUILD INTO THE
AREA TUESDAY INTO FRIDAY...BEFORE MOVING INTO THE ATLANTIC BY
SATURDAY. A COASTAL TROUGH WILL DEVELOP EARLY THIS WEEKEND THEN
LIFT NORTH OF THE REGION ON SUNDAY. A COLD FRONT WILL THEN PASS
OFF THE COAST EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
WEAK COLD FRONT HAS CLEARED THE GEORGIA COAST WITH A PRONOUNCED
POST-FRONTAL SURFACE TROUGH DROPPING SOUTH. THE TROUGH HAS PASSED
THE CHARLESTON AIRPORT AND WILL CONTINUE TO MOVE SLOWLY SOUTH
THROUGH SUNRISE. LOW STRATUS AND EVENTUALLY FOG WILL AFFECT THE
REGION OVERNIGHT WITH OCCASIONAL LIGHT DRIZZLE. SKIES HAVE CLEARED
BRIEFLY ACROSS ALLENDALE COUNTY AND DENSE RADIATION FOG HAS
QUICKLY DEVELOPED. ITS UNCLEAR HOW LONG THE DENSE FOG WILL
LAST...BUT IT MAY BE ANOTHER 1-2 HOURS BEFORE LOW CLOUDS FILL IN
FROM THE NORTH. IN FACT...CLEARING AND DENSE FOG COULD OCCUR
ACROSS MUCH OF THE FAR WESTERN ZONES FOR THE NEXT FEW HOURS. WILL
WATCH TRENDS CAREFULLY. OTHERWISE...DRIZZLE AND EXTENSIVE CLOUD
COVER WILL PERSIST. IT IS UNCLEAR HOW STRONG POST-FRONTAL STRATUS
BUILD DOWN WILL BE...BUT THERE IS A POTENTIAL FOR SOME DENSE FOG.
MADE ADJUSTMENTS TO CLOUD COVER...FOG COVERAGE AND INTRODUCED
AREAS OF DRIZZLE INTO THE FORECAST FOR THE MIDNIGHT UPDATE. THE
REST OF THE FORECAST IS OKAY.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY/...
TUESDAY AND TUESDAY NIGHT...NEARLY ZONAL FLOW WILL PREVAIL ALOFT AS
A COLD FRONT SLIPS OFF SHORE. BACK TO THE WEST...CONFLUENT FLOW
ALOFT WILL HELP TO FORCE AN IMPRESSIVE 1058 MB HIGH OVER THE
NORTHERN ROCKIES THAT WILL BUILD INTO THE FORECAST AREA THROUGH THE
DAY. FOLLOWING LOW LEVEL THETA E FIELDS...THE LEADING EDGE OF THE
COOLER AIR BEHIND THE FRONT AND THE EXTENT OF THE STRONG SURFACE
HIGH WILL NOT OOZE INTO THE AREA UNTIL LATER IN THE DAY ON TUESDAY
AND POSSIBLY EVEN INTO THE EVENING. AHEAD OF THIS THETA E
GRADIENT...RESIDUAL MOISTURE IN THE LOWEST 3-4K FT OF THE
ATMOSPHERE SHOWS UP WELL IN MODEL TIME HEIGHTS AND CROSS SECTIONS.
THIS SHOULD MANIFEST ITSELF IN THE FORM OF EXTENSIVE STRATUS
ACROSS THE FORECAST AREA FOR MUCH OF THE DAY. IN FACT...WE MAY NOT
SEE ANY CLEARING IN THE TRI-COUNTY REGION UNTIL LATE IN THE
AFTERNOON. THIS WILL HELP KEEP TEMPERATURES AT BAY DESPITE THE
LATER ARRIVAL OF THE COOLER AIR. LOOK FOR HIGHS IN THE MID/UPPER
50S FURTHER NORTH...AND LOW 60S FURTHER TO THE SOUTH. SOME OF THE
MODELS ARE WRINGING OUT SOME MEASURABLE PRECIPITATION IN THE
MORNING DESPITE THE LACK OF FORCING AND RELATIVELY SHALLOW MOIST
LAYER. HAVE KEPT THE FORECAST DRY. OVERNIGHT...COOL NORTHERLY FLOW
WILL SETTLE IN AS THE LOW LEVELS START TO DRY OUT. THE FORECAST IS
DRY AND FEATURES LOWS FALLING INTO THE UPPER 30S NORTH...LOW 40S
FURTHER SOUTH FOR COASTAL SOUTHEAST GEORGIA.
WEDNESDAY THROUGH THURSDAY...ZONAL FLOW WILL PREVAIL ALOFT AS
EXPANSIVE BUT WEAKENING HIGH PRESSURE BUILDS IN FROM THE WEST. WE
MAY BE DEALING WITH A DECENT AMOUNT OF JET-INDUCED HIGH CLOUDS ON
WEDNESDAY...BUT A COLUMN THAT IS OVERALL VERY DRY WILL KEEP THE
FORECAST RAIN FREE THROUGH THURSDAY. TEMPERATURES WILL BE ON THE
COOL SIDE WEDNESDAY...RUNNING ABOUT 4 DEGREES BELOW NORMAL...THEN
RIGHT AROUND NORMAL ON THURSDAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
THE EXPANSIVE SURFACE HIGH WILL STEADILY SHIFT OVER GEORGIA AND
THE CAROLINAS BY FRIDAY...BEFORE MOVING INTO THE ATLANTIC WATERS
SATURDAY. A STRONG CUT OFF LOW OVER THE DESERT SOUTHWEST FRIDAY WILL
EJECT INTO THE SOUTHERN PLAINS OVER THE WEEKEND AND THEN DAMPEN
AS IT MOVE INTO THE UPPER GULF COAST REGION BY LATE WEEKEND. CLOUDS
WILL BE ON THE INCREASE THURSDAY NIGHT AS A SHORT WAVES TRAVERSES
INTO THE REGION ATOP A LARGE SUBTROPICAL RIDGE OVER FLORIDA AND
THE CARIBBEAN. THIS DISTURBANCE MAY PRODUCE SOME SPOTTY LIGHT RAINS
ON FRIDAY BUT CERTAINLY NOT SIGNIFICANT AS PRECIP IS LIKELY TO
EVAPORATE IN DRY LAYERS BELOW 10 KFT. A SLIGHT CHANCE POP LOOKS QUITE
SUFFICIENT. STEADIER RAINS ACROSS NORTH GEORGIA AND THE WESTERN
CAROLINAS MAY BEGIN TO ANCHOR A WEDGE ON SATURDAY WITH GLOBAL
MODELS DIFFERING ON SURFACE PATTERNS. THE WEEKEND LOOKS A BIT
UNSETTLED WITH PLENTY OF CLOUDS MOST AREAS AND MAINLY LOW END CHANCE
POPS AS THE UPPER WAVE FLATTENS SIGNIFICANTLY LATE IN THE WEEKEND.
SUNDAY APPEARS TO BE THE WARMER OF THE DAYS AFTER WE TRENDED DOWN A
GOOD BIT ON TEMPS NORTHERN ZONES SATURDAY. A COLD FRONT SHOULD MOVE
OFF THE COAST EARLY NEXT WEEK.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
LIFR CIGS WILL LINGER AT BOTH TERMINALS THROUGH SUNRISE. CIGS WILL
REMAIN BELOW ALTERNATE MINIMUMS AND COULD DROP BELOW AIRPORT
MINIMUMS OVER THE NEXT FEW HOURS. FOG COULD BECOME A PROBLEM
LATE...BUT THE LOW CIGS WILL BE THE PRIMARY ISSUE UNLESS THE
STRATUS DECKS REACH THE GROUND RESULTING IN DENSE FOG. LOW
CONFIDENCE IN THIS SCENARIO RIGHT NOW. CIGS WILL LIFT EVER SO
SLOWLY AFTER SUNRISE...BUT SHOULD RISE ABOVE ALTERNATE MINIMUMS
13-14Z...ALTHOUGH STAYING IN IFR. MVFR SHOULD RETURN BY 16-17Z AND
LINGER THE REST OF THE 06Z TAF PERIOD.
EXTENDED AVIATION OUTLOOK...LOW CEILINGS TO CLEAR OUT TUESDAY
NIGHT...IF NOT BEFORE. VFR CONDITIONS WILL THEN PREVAIL THROUGH AT
LEAST THURSDAY. CHANCES FOR FLIGHT RESTRICTIONS INCREASE INTO THE
WEEKEND AS THE NEXT SYSTEM IMPACTS THE REGION.
&&
.MARINE...
TONIGHT...WEBCAMS OUT OF TYBEE ISLAND AND EARLIER REPORTS FROM THE
SAINT SIMMONS BAR PILOT BOAT PROVIDE ENOUGH DATA TO SUPPORT A
MARINE DENSE FOG ADVISORY FOR THE GEORGIA NEARSHORE WATERS THROUGH
6 AM. RAP VSBY PROGS APPEAR TO CAPTURE THE SEA FOG WELL AND WAS
USED TO CONSTRUCT WEATHER AND VSBY GRIDS THROUGH 6 AM.
TUESDAY THROUGH SATURDAY...A COLD FRONT WILL PUSH WELL OFFSHORE
TUESDAY AS HIGH PRESSURE WILL BEGIN TO BUILD IN TUESDAY NIGHT. AS
THE HIGH BUILDS IN A NOTABLE NORTHERLY SURGE WILL TAKE PLACE TUESDAY
NIGHT AND INTO WEDNESDAY MORNING. A SOLID 15-20 KT OF WIND IS
EXPECTED WITHIN 20 NM WITH SOME GUSTS TO 25 KT POSSIBLE. WINDS WILL
BE CLOSER TO 20-25 KT FOR THE OUTER GEORGIA WATERS WITH SOME 6 FT
SEAS POSSIBLE. SMALL CRAFT ADVISORIES MAY BE NEEDED...ESPECIALLY FOR
THE OUTER GEORGIA WATERS TUESDAY NIGHT. THEREAFTER...HIGH PRESSURE
WILL BE THE PRIMARY WEATHER FEATURE THOUGH THE GRADIENT WILL RELAX.
IT IS STILL A BIT TOO EARLY TO COMMIT ON STRENGTH OF THE WEDGE THIS
WEEKEND AND TIMING THE WARM FRONT THROUGH...BUT COMPLEX LOW LEVEL
MIXING ENVIRONMENTS ARE LIKELY.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
AMZ354.
&&
$$
ST
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
229 AM CST TUE DEC 30 2014
.SHORT TERM...
229 AM CST
THROUGH WEDNESDAY...
ONE WORD SUMS UP THE ENTIRE SHORT TERM FORECAST: COLD. SOMEWHAT
MODIFIED ARCTIC AIR IS SEEPING SOUTH AND SHOULD SET THE STAGE FOR
SEASONABLY COLD CONDITIONS THE NEXT COUPLE DAYS. THE LACK OF SNOW
COVER HERE OR IMMEDIATELY UPSTREAM SHOULD ALLOW THE AIR MASS TO
MODIFY SOME AND WE CERTAINLY WILL NOT BE ANYWHERE NEAR AS COLD AS
IT WOULD BE WITH SNOW COVER.
STRONG LOW PRESSURE WILL DROP SOUTH INTO HUDSON BAY WEDNESDAY AND WE
COMBINED WITH THE STRONG HIGH TO OUR SOUTH WILL SET THE STAGE FOR AN
INCREASINGLY WINDY DAY WEDNESDAY...SO EVEN THOUGH TEMPERATURES WILL
BE IN THE SAME BALLPARK AS TODAY ON WEDNESDAY THE STRONG WINDS WILL
MAKE IT FEEL COLDER WITH WIND CHILLS HOVERING NEAR ZERO OR EVEN A
BIT BELOW ALL DAY AND INTO NEW YEARS EVE NIGHT.
IZZI
&&
.LONG TERM...
229 AM CST
WEDNESDAY NIGHT THROUGH MONDAY...
TROUGH OVER THE REGION WILL RETREAT WITH RISING HEIGHTS AND
MODERATING TEMPERATURES THURSDAY AND FRIDAY WITH GENERALLY DRY
CONDITIONS. IN THE LONGER TERM ALL EYES WILL BE ON WHAT BECOMES OF
THE POWERFUL CUT OFF SYSTEM OVER THE SOUTHWEST. MEDIUM RANGE MODELS
CONTINUE TO WAFFLE AROUND WITH TIMING...TRACK...AND INTENSITY
VARYING FROM RUN TO RUN AND MODEL TO MODEL. THESE TYPE OF SYSTEMS
ARE NOT WELL HANDLED BY NUMERICAL GUIDANCE AND WOULD EXPECT CONTINUE
MODEL VARIANCES...SOME POSSIBLY SIGNIFICANT...IN THE COMING DAYS SO
AM NOT WILLING TO STRAY FROM THE BLENDED MODEL GUIDANCE WITH LOW
POPS AND RAIN OR SNOW FOR P-TYPE. DOES LOOK LIKE MORE COLD AIR WILL
PROBABLY SPILL INTO THE AREA BEHIND THAT SOUTHWESTERN SYSTEM WHEN
EVER IT DOES END UP PASSING BY.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* NORTH-NORTHWEST WINDS 10 KT OR HIGHER GRADUALLY SHIFTING WEST
LATER TODAY.
//DISCUSSION...UPDATED 06Z...
ISOLATED MVFR CIGS ARE LARGELY PASSING SOUTH OF A KVYS-KMGC
LINE...WITH A VFR DECK SLIDING SE THROUGH THE AREA THIS EVENING.
THE VFR DECK WILL CONTINUE MOVING SE AND SHOULD CLEAR THE AREA BY
DAYBREAK...WITH ANY ADDITIONAL LAKE INDUCED MVFR TO BE EAST OF
KGYY. ONLY CLOUDS LEFT WILL BE PASSING HIGH CLOUDS FROM A LOW IN
COLORADO. OTHERWISE...HIGH PRESSURE NOSES SOUTH INTO THE PLAINS TODAY
WHICH WILL ALONG NORTH- NORTHWEST WINDS TO TAKE ON A MORE WESTERLY
COMPONENT THROUGH THE DAY...LARGELY STAYING FROM 9-12 KT THROUGH
THE PERIOD.
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM-HIGH IN WINDS.
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
WEDNESDAY...VFR. STIFF SOUTHWEST WINDS.
THURSDAY-FRIDAY...VFR. WEST-SOUTHWEST WINDS.
SATURDAY-SUNDAY...CHANCE OF SNOW AND IFR.
MTF
&&
.MARINE...
304 PM CST
NORTH TO NORTHWEST WINDS PERSIST ACROSS THE LAKE TONIGHT...THEN
GRADUALLY BACK SOUTHWEST BY WEDNESDAY AND INCREASE TO GALES BY
WEDNESDAY AFTERNOON OR EVENING. IT IS NOT CERTAIN HOW EFFECTIVELY
THESE SOMEWHAT MILDER SOUTHWEST WINDS WILL SUPPORT STRONG GALES
OVER THE COLD WATER...BUT GALES DO APPEAR LIKELY. UNTIL WINDS TURN
AWAY FROM NORTH AND NORTHWEST...CONDITIONS WILL BE FAVORABLE FOR
SMALL CRAFT HEADLINES FOR THE FIRST HALF OF THE WEEK...AND
ESPECIALLY IN THE INDIANA NEARSHORE WATERS.
LENNING
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL MIDNIGHT
WEDNESDAY.
GALE WATCH...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-LMZ567-
LMZ868...9 AM WEDNESDAY TO 3 AM THURSDAY.
GALE WATCH...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...NOON WEDNESDAY TO 3 AM
THURSDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1128 PM CST Mon Dec 29 2014
.UPDATE...
ISSUED AT 900 PM CST MON DEC 29 2014
The lift being generated in the post frontal airmass has been very
weak, based on radar returns and local observations. Have only
seen isolated reports of flurries so far. A clearing line just
north of the band of clouds/flurries is progressing southward,
which would spell an end to the very narrow channel of
lift/clouds/flurries. Have updated the sky grids to account for
some clearing later tonight at least across the northern counties.
Less cloud cover would mean colder lows that we currently have, a
bit more toward the colder guidance numbers. Have trimmed a few
degrees from lows NW of a line from SPI to BMI. Will keep a
mention of flurries in tonight`s forecast following the trek of the
band of clouds to the SE. No other significant changes needed this
evening. Tomorrow looks like a colder but mostly sunny day. Updated
info will be available shortly.
&&
.SHORT TERM...(Tonight)
ISSUED AT 315 PM CST MON DEC 29 2014
The 18Z surface analysis indicated the leading edge of the Arctic
airmass, ahead of an intense high pressure center in the Canadian
Rockies, was sinking just south of I-80. Clouds associated with cold
air undercutting were along the I-74 corridor at 20z/2 pm CST. This
area of cloudiness, along with low clouds in southern Iowa/northern
Missouri will overspread central and eventually southeast Illinois
this evening.
There should be enough weak forcing for snow flurries, particularly
in central Illinois this evening, and the rest of the forecast area
late tonight as the short range models point to weak lift just
behind the strongest low level cold advection. The HRRR model is
trying to produce some measurable snow from Bloomington to near
Taylorville between 6 pm and Midnight. At this point, it is the only
model, doing this and has most likely latched on to the area of
light snow around Pontiac. Will keep an eye on this, but for now
will stick to the mention of flurries.
The numerical guidance appears to be on the colder side due to less
cloud cover and stronger cold advection. Thus, will be going with
lows roughly 5 degrees warmer than guidance in central IL and 2-3
degrees warmer in southeast IL due to forecast cloud cover.
&&
.LONG TERM...(Tuesday through Monday)
ISSUED AT 315 PM CST MON DEC 29 2014
The narrow band of flurries will continue into Tuesday morning, but
should dissipate by afternoon. Behind this area, and strong 1050mb
high pressure area will drop into the region. This high will bring
dry weather to the area through Thur night, as well as well below
normal temps through the period. With the center of the high
dropping into the plains Tue night, the coldest temps are expected
to be Tue night through Wed. Northwesterly winds Tue night will
still be around 10mph, so there could be enough mixing to prevent
the bottom from dropping out on the temps. However, single digits
are still expected over half of the CWA, and combined with the wind
speeds, below zero wind chills are probably Tue night/Wed morning.
Beyond this, the high pressure will slide further south into the
southern plains by Thursday night. Temps may warm slightly, but only
to back around normal.
The return of slightly warmer temps and moisture will not occur
until the high pressure area move into the southeastern US Thur
night and Fri. However, along with this will come the chance of pcpn
to the area for the end of the week and the weekend. The questions
still remain as to the timing of the pcpn return, how warm it will
get, and what p-type will occur. Both the GFS and ECMWF continue to
not agree on the overall solution with this system. However, there
is some agreement as to how the upper level will evolve into
Saturday. The upper level low pressure area will weaken and get
lifted out into the flow over the weekend. ECMWF is much quicker
with this than the GFS. Models also agree that the pcpn will not
really begin until Fri night/Sat morning. However, there still
remains a chance of pcpn Friday in the southeast, so will keep
chance pops there, though would not be surprised to see this change
later. Beyond this, models do not agree with location of pcpn and
sfc low pressure area. With the ECMWF being quicker with the upper
level system, it keeps the low further south and therefore has very
little pcpn in our area...and only in the extreme southeast. The GFS
is further north with the low, but has shifted it east since
yesterday`s model runs. However, it keeps pcpn over the area through
the weekend, just not as much as before; and with the low east,
temps may not get as warm, thereby effecting the p-type through the
weekend. Will still be keeping the p-type simple and just going with
snow, becoming rain or snow, then snow at night and rain and/or snow
again during the daytime. The chance of pcpn will continue into Sat
night. Sunday and Monday will be dry for now as the system should be
well east of the area.
Temps in the extended will warm, with the warmest temps being on
Saturday and then cooling back off by Monday as another shot of
colder air slides into the area.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
ISSUED AT 1128 PM CST MON DEC 29 2014
The weak cold front has pretty much dissipated this evening, with
just a lingering band of clouds and possibly a few flurries
drifting southward across the area. In general, a 2-4
hour period of MVFR clouds could occur over the terminal sites the
rest of the night. The base cloud layer appears to be very ragged,
and periods of MVFR could be broken up by VFR conditions. Have
included flurries only at BMI, with dry conditions elsewhere. No
impacts are expected from any snowfall overnight.
Mid clouds are indicated in the forecast soundings for the day on
Tuesday, with gradual lowering of the mid-deck Tuesday evening
down to 10K feet. Breaks in the mid-clouds appears likely based on
the amount of dry air above and below the cloud layer.
Winds will start out NNE, then shift to the N by sunrise and NW
Tuesday afternoon. Wind speeds will generally hover btwn 6-9kt at
night and 9-12kt during the day.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Shimon
SHORT TERM...Miller
LONG TERM...Auten
AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1115 PM CST MON DEC 29 2014
.SHORT TERM...
323 PM CST
REMAINDER OF THIS AFTERNOON AND TONIGHT...
LAKE EFFECT SNOW HAS LARGELY BEEN A NON-EVENT THIS AFTERNOON...
MAINLY DUE TO VERY DRY LOW LEVEL AIR IN PLACE OVER NERN
IL/NWRN...WITH DEWPOINTS IN THE UPPER TEENS IN SPITE OF THE NELY
FETCH OFF LAKE LAKE MICHIGAN WHERE WATER TEMPERATURES ARE STILL IN
THE MIDDLE TO UPPER 30S. THE MAIN IMPACT OF THE LAKE HAS BEEN A
BKN-OVC STRATOCU DECK MOVING OFF OF THE LAKE. HOWEVER...THERE HAS
BEEN SOME SCT LIGHT SNOW WITH THE COLD FRONT/LEADING EDGE OF THE
ARCTIC AIRMASS BUILDING ACROSS THE MISSISSIPPI VALLEY AND INTO THE
OHIO VALLEY. WHILE DEEP LAYER MOISTURE HAS BEEN MEAGER...THERE IS
JUST ENOUGH FORCING TO SQUEEZE OUT SOME ISOLD AREAS OF LIGHT
SNOW...MAINLY OVER PORTIONS OF THE AREA SOUTH OF I-80. FOR THE
OVERNIGHT HOURS...AS THE HIGH CONTINUES TO SPREAD SOUTH AND EAST
AND THE CENTER OF THE HIGH BUILDS INTO THE NRN PLAINS/NRN
ROCKIES...LOW LEVEL FLOW SHOULD GRADUALLY BACK THROUGH NLY TO
WNWLY. THE LONGER LAKE FETCH WHEN WINDS BECOME NLY COULD STILL
HELP BRING SOME LAKE EFFECT SNOW SHOWERS TO NWRN INDIANA...BUT
HAVE BACKED OFF ON QPF/SNOW AMOUNTS...WHILE MAINTAINING THE LIKELY
POPS...WITH THE IDEA OF A HIGH POP-LOW QPF SCENARIO. SO...STILL
THINK THERE COULD BE SOME ACCUMULATING LAKE EFFECT SNOW OVER
PORTIONS OF NWRN INDIANA NEAR THE LAKE...BUT AMOUNTS WILL LIKELY
BE LIGHT. AS THE ARCTIC AIRMASS CONTINUES TO SPREAD SOUTH AND
EAST...EXPECT LOWS TONIGHT TO DROP TO NEAR 10F OVER THE ROCKFORD
AREA...WHILE LOCATIONS EAST OF THE I-55 CORRIDOR SHOULD BE IN THE
UPPER TEENS TO LOWER 20S.
KREIN
&&
.LONG TERM...
323 PM CST
TUESDAY THROUGH MONDAY...
WHILE A COOLING TREND INITIATED BEGAN SUNDAY FOLLOWING THE PASSAGE
OF A COLD FRONT LATE SATURDAY...THE MORE SIGNIFICANT COOLING TREND
IS NOW UNDERWAY AS THE TRUE ARCTIC AIRMASS SPREADS ACROSS THE
REGION. AS OF 3PM CST MONDAY AFTERNOON...TEMPERATURES IN THE
NORTHERN PLAINS RANGED FROM THE SINGLE DIGITS ABOVE 0F TO THE SINGLE
DIGITS BELOW ZERO WITH DEWPOINTS OF -10 TO -15F. THE COLD AIR IS
STILL EXPECTED TO SPREAD ACROSS THE LOCAL AREA...BUT THE COLDEST AIR
SHOULD REMAIN TO THE WEST...OVER THE PLAINS AS THE CENTER OF THE
HIGH DROPS FROM THE NORTHERN ROCKIES TONIGHT TO THE LOWER
MISSISSIPPI VALLEY BY THURSDAY MORNING. CONDITIONS ACROSS THE AREA
SHOULD GENERALLY BE DRY THROUGH THURSDAY...WITH BELOW NORMAL
TEMPERATURES AND AMPLE SUNSHINE AS THE SFC HIGH PRESSURE BUILDS
ACROSS THE REGION. STILL ANTICIPATE THAT THE LOWEST TEMPERATURES
SHOULD BE TUESDAY NIGHT INTO WEDNESDAY MORNING AS THE SFC RIDGE AXIS
BUILDS ACROSS THE AREA. WILL CARRY MIN TEMPS FOR WEDNESDAY MORNING
IN THE SINGLE DIGITS FOR THE ENTIRE CWA...RANGING FROM ARND 3F OVER
THE ROCKFORD AREA TO 8-9F EAST OF THE I-57 CORRIDOR. THERE IS SOME
CONCERN THAT THE TEMP FORECAST MAY BE A BIT TOO LOW...CONSIDERING
WINDS SHOULD REMAIN 5-10 MPH OVERNIGHT AND THERE IS NO SNOW COVER.
HOWEVER...EVEN THOUGH THE AIRMASS WILL BE VERY DRY AND SKIES SHOULD
BE MOSTLY CLEAR...EXPECT THAT THE LOWER TEMPERATURES WILL BE MORE
DRIVEN BY ADVECTION OF COLDER AIR FROM THE CENTRAL PLAINS...WITH THE
CENTER OF A 1050MB HIGH WILL BE CENTERED ALONG THE KANSAS COLORADO
BORDER...WITH A RIDGE AXIS EXTENDING TO THE EAST ACROSS CNTRL
ILLINOIS AND INTO THE UPPER OHIO VALLEY. WITH A DIGGING TROUGH
DROPPING THROUGH SCNTRL CANADA...A MODEST WLY GRADIENT WILL BE IN
PLACE...KEEPING WINDS FROM BECMG CALM. SO...EVEN THOUGH THERE IS NO
SNOW COVER OR CALM WINDS TO ALLOW FOR STRONG RADIATIVE COOLING TO
CAUSE THE TEMPERATURES TO DROP INTO THE SINGLE DIGITS...FEEL THAT
THERE WILL BE ENOUGH ADVECTION OF COLD AIR FROM THE CNTRL PLAINS TO
BRING THE LOW TEMPERATURES. THE MAIN IMPACT OF THIS COLD AIR AND
RELATIVELY BREEZY CONDITIONS WILL BE FOR WIND CHILL READINGS TO DROP
TO -5 TO -13 ACROSS THE CWA...WHICH WOULD THE COLDEST SINCE LATE
NOVEMBER.
THE OTHER FORECAST CONCERN FOR THE EXTENDED FORECAST PERIOD WILL BE
ASSOCIATED WITH A CLOSED LOW EXPECTED TO DROP INTO THE DESERT
SOUTHWEST WEDNESDAY AND WEDNESDAY NIGHT AS A STRONG PACIFIC
SHORTWAVE DROPS DOWN THE WEST COAST. THE MODELS HAVE BEEN VERY
CONSISTENT ON THE DEVELOPMENT OF THIS FEATURE...BUT THERE IS STILL A
VARIETY OF SOLUTIONS FROM THE VARIOUS MODELS IN THE TIMING OF
EJECTING THE SYSTEM OUT OF THE SRN ROCKIES AND TRACKING ACROSS THE
SOUTHERN PLAINS AND THEN LIFTING INTO THE OHIO VALLEY. THE GFS/GEM
REMAIN ON THE FASTER END OF THE FORECAST ENVELOPE WHILE THE ECMWF IS
THE CONSISTENTLY SLOWER SOLUTION. WHILE THE SLOWER SOLUTION IS
STILL FAVORED...CONFIDENCE IS STILL LOW THAT THE EVENTUAL
PROGRESSION OF THE SYSTEM COULD STILL BE SLOWER THAN WHAT THE ECMWF
CONTINUES TO INDICATE. SO...WILL MAINTAIN THE IDEA OF A SLOWER
SOLUTION. THE MAIN TREND FOR THE SENSIBLE WEATHER FEATURES SHOULD
BE A WARMING TREND WITH MAX TEMPS REBOUNDING INTO THE 30S FOR FRIDAY
AND SATURDAY AS UPPER HEIGHTS RISE IN ADVANCE OF THE UPPER LOW
EJECTING OUT OF THE DESERT SOUTHWEST. THERE IS DECENT CONFIDENCE IN
THIS GENERAL TREND. THERE IS ALSO DECENT CONFIDENCE IN THE IDEA OF
INCREASING POPS INTO THE WEEKEND...WHICH IS SLOW THAN PREVIOUSLY
FORECAST AND IN LINE WITH A SLOWER PROGRESSION OF THE SYSTEM.
HOWEVER THERE IS RELATIVELY LOW CONFIDENCE IN TIMING AND AMOUNT OF
PCPN AS THERE IS STILL THE CHANCE FOR SOME PHASING OF THE SRN STREAM
SYSTEM WITH NRN STREAM SHORT WAVE ENERGY DROPPING OUT OF THE NRN
PLAINS AND ACROSS THE GREAT LAKES. SO...WILL LIMIT POPS TO CHANCE
LEVELS FOR NOW WITH THE TREND TO DELAY THE ONSET OF ANY PCPN INTO
LATER IN THE FORECAST PERIOD.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* NORTH-NORTHWEST WINDS 10 KT OR HIGHER GRADUALLY SHIFTING WEST
LATER TODAY.
//DISCUSSION...UPDATED 06Z...
ISOLATED MVFR CIGS ARE LARGELY PASSING SOUTH OF A KVYS-KMGC
LINE...WITH A VFR DECK SLIDING SE THROUGH THE AREA THIS EVENING.
THE VFR DECK WILL CONTINUE MOVING SE AND SHOULD CLEAR THE AREA BY
DAYBREAK...WITH ANY ADDITIONAL LAKE INDUCED MVFR TO BE EAST OF
KGYY. ONLY CLOUDS LEFT WILL BE PASSING HIGH CLOUDS FROM A LOW IN
COLORADO. OTHERWISE...HIGH PRESSURE NOSES SOUTH INTO THE PLAINS TODAY
WHICH WILL ALONG NORTH- NORTHWEST WINDS TO TAKE ON A MORE WESTERLY
COMPONENT THROUGH THE DAY...LARGELY STAYING FROM 9-12 KT THROUGH
THE PERIOD.
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM-HIGH IN WINDS.
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
WEDNESDAY...VFR. STIFF SOUTHWEST WINDS.
THURSDAY-FRIDAY...VFR. WEST-SOUTHWEST WINDS.
SATURDAY-SUNDAY...CHANCE OF SNOW AND IFR.
MTF
&&
.MARINE...
304 PM CST
NORTH TO NORTHWEST WINDS PERSIST ACROSS THE LAKE TONIGHT...THEN
GRADUALLY BACK SOUTHWEST BY WEDNESDAY AND INCREASE TO GALES BY
WEDNESDAY AFTERNOON OR EVENING. IT IS NOT CERTAIN HOW EFFECTIVELY
THESE SOMEWHAT MILDER SOUTHWEST WINDS WILL SUPPORT STRONG GALES
OVER THE COLD WATER...BUT GALES DO APPEAR LIKELY. UNTIL WINDS TURN
AWAY FROM NORTH AND NORTHWEST...CONDITIONS WILL BE FAVORABLE FOR
SMALL CRAFT HEADLINES FOR THE FIRST HALF OF THE WEEK...AND
ESPECIALLY IN THE INDIANA NEARSHORE WATERS.
LENNING
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
909 PM CST Mon Dec 29 2014
.UPDATE...
ISSUED AT 900 PM CST MON DEC 29 2014
The lift being generated in the post frontal airmass has been very
weak, based on radar returns and local observations. Have only
seen isolated reports of flurries so far. A clearing line just
north of the band of clouds/flurries is progressing southward,
which would spell an end to the very narrow channel of
lift/clouds/flurries. Have updated the sky grids to account for
some clearing later tonight at least across the northern counties.
Less cloud cover would mean colder lows that we currently have, a
bit more toward the colder guidance numbers. Have trimmed a few
degrees from lows NW of a line from SPI to BMI. Will keep a
mention of flurries in tonight`s forecast following the trek of the
band of clouds to the SE. No other significant changes needed this
evening. Tomorrow looks like a colder but mostly sunny day. Updated
info will be available shortly.
&&
.SHORT TERM...(Tonight)
ISSUED AT 315 PM CST MON DEC 29 2014
The 18Z surface analysis indicated the leading edge of the Arctic
airmass, ahead of an intense high pressure center in the Canadian
Rockies, was sinking just south of I-80. Clouds associated with cold
air undercutting were along the I-74 corridor at 20z/2 pm CST. This
area of cloudiness, along with low clouds in southern Iowa/northern
Missouri will overspread central and eventually southeast Illinois
this evening.
There should be enough weak forcing for snow flurries, particularly
in central Illinois this evening, and the rest of the forecast area
late tonight as the short range models point to weak lift just
behind the strongest low level cold advection. The HRRR model is
trying to produce some measurable snow from Bloomington to near
Taylorville between 6 pm and Midnight. At this point, it is the only
model, doing this and has most likely latched on to the area of
light snow around Pontiac. Will keep an eye on this, but for now
will stick to the mention of flurries.
The numerical guidance appears to be on the colder side due to less
cloud cover and stronger cold advection. Thus, will be going with
lows roughly 5 degrees warmer than guidance in central IL and 2-3
degrees warmer in southeast IL due to forecast cloud cover.
&&
.LONG TERM...(Tuesday through Monday)
ISSUED AT 315 PM CST MON DEC 29 2014
The narrow band of flurries will continue into Tuesday morning, but
should dissipate by afternoon. Behind this area, and strong 1050mb
high pressure area will drop into the region. This high will bring
dry weather to the area through Thur night, as well as well below
normal temps through the period. With the center of the high
dropping into the plains Tue night, the coldest temps are expected
to be Tue night through Wed. Northwesterly winds Tue night will
still be around 10mph, so there could be enough mixing to prevent
the bottom from dropping out on the temps. However, single digits
are still expected over half of the CWA, and combined with the wind
speeds, below zero wind chills are probably Tue night/Wed morning.
Beyond this, the high pressure will slide further south into the
southern plains by Thursday night. Temps may warm slightly, but only
to back around normal.
The return of slightly warmer temps and moisture will not occur
until the high pressure area move into the southeastern US Thur
night and Fri. However, along with this will come the chance of pcpn
to the area for the end of the week and the weekend. The questions
still remain as to the timing of the pcpn return, how warm it will
get, and what p-type will occur. Both the GFS and ECMWF continue to
not agree on the overall solution with this system. However, there
is some agreement as to how the upper level will evolve into
Saturday. The upper level low pressure area will weaken and get
lifted out into the flow over the weekend. ECMWF is much quicker
with this than the GFS. Models also agree that the pcpn will not
really begin until Fri night/Sat morning. However, there still
remains a chance of pcpn Friday in the southeast, so will keep
chance pops there, though would not be surprised to see this change
later. Beyond this, models do not agree with location of pcpn and
sfc low pressure area. With the ECMWF being quicker with the upper
level system, it keeps the low further south and therefore has very
little pcpn in our area...and only in the extreme southeast. The GFS
is further north with the low, but has shifted it east since
yesterday`s model runs. However, it keeps pcpn over the area through
the weekend, just not as much as before; and with the low east,
temps may not get as warm, thereby effecting the p-type through the
weekend. Will still be keeping the p-type simple and just going with
snow, becoming rain or snow, then snow at night and rain and/or snow
again during the daytime. The chance of pcpn will continue into Sat
night. Sunday and Monday will be dry for now as the system should be
well east of the area.
Temps in the extended will warm, with the warmest temps being on
Saturday and then cooling back off by Monday as another shot of
colder air slides into the area.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
ISSUED AT 543 PM CST MON DEC 29 2014
The arctic front will continue to slide south and east tonight, as
it dissipates. Flurries will be the primary precipitation, and
will develop behind the front in the region of lift. The RAP and
HRRR are both indicating the area of light snow that lowered visibility
to 3 miles will drift south through Bloomington and eventually
just east of Lincoln toward Taylorville. It is projected to weaken
as it shifts south, but Bloomington may see visibility drop to
MVFR levels in light snow for a couple of hours. The prevailing
cloud cover will lower to MVFR at all TAF sites this evening as
the arctic front progresses southeast. The flurries should
dissipate late tonight and MVFR clouds will break up starting
around 16z at PIA and eventually clearing at DEC around 20z.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Shimon
SHORT TERM...Miller
LONG TERM...Auten
AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS WICHITA KS
310 AM CST TUE DEC 30 2014
.SYNOPSIS...
ISSUED AT 308 AM CST TUE DEC 30 2014
LARGE POSITIVE TILTED UPPER TROUGH EXTENDS FROM THE NORTHERN
PLAINS INTO NORTHERN CA WITH THE MAIN VORT LOBE OVER THE WESTERN
PORTION OF THIS TROUGH. AT THE SURFACE...ARCTIC AIR IS SPILLING
SOUTH ACROSS THE PLAINS WITH NEGATIVE TEMP VALUES NOW ENCOMPASSING
THE NORTHERN HALF OF NEBRASKA.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 308 AM CST TUE DEC 30 2014
LIGHT SNOW HAS BEEN PERSISTENT OVERNIGHT FOR AREAS ALONG AND WEST
OF I-135 AND AM EXPECTING THIS TO CONTINUE THROUGH AT LEAST THE
MORNING HOURS AND POSSIBLY INTO THE AFTERNOON. FEEL CONFIDENT IN
THIS AS ISENTROPIC LIFT IN THE 280-285K LAYER REMAINS PRETTY MUCH
UNCHANGED FROM WHAT IS OCCURRING NOW. EVEN THOUGH MOST SITES WILL
NOT TIP OFF A 0.01 OF PRECIP...WILL RUN WITH HIGH POP WORDING AS
WHAT IS OCCURRING IS MORE THAN JUST FLURRIES WITH SOME
VISIBILITIES AT OR LESS THAN 3SM. WILL KEEP WITH CURRENT HEADLINE
MAINLY DUE TO COMING CLOSE TO WIND CHILL CRITERIA.
THE FRIGID AIRMASS WILL REMAIN IN PLACE TONIGHT THROUGH WED WITH
TEMPS AROUND 20 DEGREES BELOW NORMAL. WOULD NOT BE SHOCKED IF WE
GET SOME FLURRIES TO LINGER TONIGHT OVER THE SOUTHWEST PORTION OF
THE FORECAST AREA AS THE LIFT IS SLOW TO MOVE OUT. THE MAIN VORT
LOBE OUT WEST IS EXPECTED TO CUT OFF AND TRACK ACROSS THE DESERT
SOUTHWEST BY THU AND WILL BECOME THE FOCUS FOR THE EXTENDED
PERIODS.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 308 AM CST TUE DEC 30 2014
THROUGH 00Z SAT BOTH THE ECMWF AND GFS REMAIN FAIRLY SIMILAR IN
TRACKING THE CLOSED LOW OVER EASTERN NM. HOWEVER...THESE MODELS
AGAIN START TO DEVIATE FOR THE FRI NIGHT THROUGH SAT TIME FRAME.
THE GFS IS CONTINUING THE TREND OF LIFTING THE IMPULSE FURTHER
NORTH COMPARED TO THE ECMWF. THE GFS SOLUTION WOULD RESULT IN
WIDESPREAD WINTRY PRECIP FOR MOST OF THE FORECAST AREA FRI NIGHT
INTO SAT MORNING WITH THE ECMWF KEEPING MOST OF THE PRECIP SOUTH
OF THE KS/OK BORDER. HAVE A SLIGHT LEAN TO THE GFS SINCE IT HAS
BEEN A BIT MORE CONSISTENT AND FEEL THAT AT LEAST A PORTION OF OUR
FORECAST AREA WILL BE IMPACTED BY WINTRY PRECIP OVER THE WEEKEND.
LAWSON
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1135 PM CST MON DEC 29 2014
LIGHT SNOW IS MOVING ACROSS THE WESTERN SECTIONS OF THE FORECAST
AREA IMPACTING KRSL/KHUT/KICT AND WILL SOON IMPACT KSLN. MVFR TO
IFR CEILINGS AND VISIBILITIES ARE ALSO IMPACTING THE TERMINALS.
EXPECT THIS TO PERSIST THROUGH THE OVERNIGHT HOURS. THE SHORT-
TERM HIGHER RES RUC GUIDANCE SHOWS THE SNOW DIMINISHING AROUND
SUNRISE...WHILE THE NAM KEEPS PRECIP AROUND LONGER. HAVE TRENDED
TOWARD THE RUC AT THIS TIME IN THE TAFS ENDING THE SNOW AROUND
SUNRISE AND EVENTUALLY LIFTING THE CEILINGS TO HIGH END MVFR AND
IN SOME CASES VFR BY THE END OF THE PERIOD. NORTH TO NORTHEASTERLY
WINDS WILL PERSIST THROUGH THE FORECAST.
BILLINGS WRIGHT
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 18 4 22 14 / 30 10 0 0
HUTCHINSON 13 2 21 13 / 40 10 0 0
NEWTON 15 2 21 13 / 20 10 0 0
ELDORADO 18 4 22 14 / 20 10 0 0
WINFIELD-KWLD 21 6 24 16 / 20 10 0 0
RUSSELL 7 -3 15 8 / 30 10 0 0
GREAT BEND 8 -2 17 10 / 30 10 0 0
SALINA 12 -1 18 12 / 30 10 0 0
MCPHERSON 12 1 20 12 / 30 10 0 0
COFFEYVILLE 30 9 27 16 / 10 10 0 0
CHANUTE 25 5 24 15 / 10 10 0 0
IOLA 23 4 24 15 / 10 10 0 0
PARSONS-KPPF 27 7 25 16 / 10 10 0 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR KSZ032-033-047-
048.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
1135 PM CST MON DEC 29 2014
...UPDATED FOR 06Z AVIATION DISCUSSION...
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 234 PM CST MON DEC 29 2014
ARCTIC AIR OVER THE DAKOTAS/NEBRASKA WAS CONTINUING TO SURGE
SOUTH AND WILL SPREAD ACROSS KANSAS FOR TONIGHT AND REMAIN OVER
THE AREA FOR THE NEXT COUPLE OF DAYS. MEANWHILE SNOW CURRENTLY
OVER NORTHWEST KANSAS WILL EXPAND EASTWARD INTO CENTRAL KANSAS FOR
TONIGHT WITH SOME LIGHT ACCUMULATIONS POSSIBLE...WITH A TRACE TO 2
INCHES POSSIBLE. THE SNOW SHOULD BEGIN TO TAPER OFF QUICKLY FOR
TUESDAY MORNING...AS THE VERTICAL MOTION FROM UPPER LEVEL WAVE
DIMINISHES. WIND CHILLS WILL DROP TO DANGEROUS LEVELS FOR TUESDAY
MORNING AND COULD AGAIN FOR WEDNESDAY MORNING ACROSS CENTRAL
KANSAS. A WIND CHILL ADVISORY COULD BE HOISTED BY LATER SHIFTS FOR
WEDNESDAY MORNING IF TRENDS MAINTAIN. TEMPERATURES SHOULD MODIFY
AND WARM A BIT COME THURSDAY AS DOWNSLOPE FLOW HELPS BOOSTS
DAYTIME HIGHS.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 234 PM CST MON DEC 29 2014
SOME UNCERTAINTY REMAINS BETWEEN THE GFS/ECMWF MODEL AS EXPECTED
THIS FAR OUT IN TIME WITH POSITIONING OF THE FRI/SAT SYSTEM...BUT
NONE THE LESS WINTER PRECIPITATION STILL SEEMS REASONABLE FOR
MAINLY SOUTH CENTRAL/SOUTHEAST KANSAS. BELOW NORMAL TEMPERATURES
WILL CONTINUE FOR SUNDAY AND MONDAY AS SURFACE HIGH PRESSURE
BUILDS OVER KANSAS...AND TEMPERATURES COULD BE EVEN COLDER IF
FRESH SNOW FALLS ACROSS THE REGION.
JAKUB
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1135 PM CST MON DEC 29 2014
LIGHT SNOW IS MOVING ACROSS THE WESTERN SECTIONS OF THE FORECAST
AREA IMPACTING KRSL/KHUT/KICT AND WILL SOON IMPACT KSLN. MVFR TO
IFR CEILINGS AND VISIBILITIES ARE ALSO IMPACTING THE TERMINALS.
EXPECT THIS TO PERSIST THROUGH THE OVERNIGHT HOURS. THE SHORT-
TERM HIGHER RES RUC GUIDANCE SHOWS THE SNOW DIMINISHING AROUND
SUNRISE...WHILE THE NAM KEEPS PRECIP AROUND LONGER. HAVE TRENDED
TOWARD THE RUC AT THIS TIME IN THE TAFS ENDING THE SNOW AROUND
SUNRISE AND EVENTUALLY LIFTING THE CEILINGS TO HIGH END MVFR AND
IN SOME CASES VFR BY THE END OF THE PERIOD. NORTH TO NORTHEASTERLY
WINDS WILL PERSIST THROUGH THE FORECAST.
BILLINGS WRIGHT
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 15 19 4 21 / 60 10 10 0
HUTCHINSON 10 15 2 20 / 100 20 10 0
NEWTON 11 17 2 20 / 50 10 10 0
ELDORADO 14 20 4 22 / 30 10 10 0
WINFIELD-KWLD 18 22 6 23 / 30 10 10 0
RUSSELL 4 9 -3 18 / 100 30 10 0
GREAT BEND 6 10 -2 18 / 100 30 10 0
SALINA 8 12 -1 19 / 90 10 10 0
MCPHERSON 9 14 1 20 / 100 10 10 0
COFFEYVILLE 23 28 9 25 / 30 10 10 0
CHANUTE 19 24 5 23 / 10 10 10 0
IOLA 18 23 4 22 / 10 10 10 0
PARSONS-KPPF 21 26 7 24 / 20 10 10 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON CST TUESDAY FOR KSZ032-033-
047-048.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1133 PM EST MON DEC 29 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 403 PM EST MON DEC 29 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH
EXTENDING FROM NRN QUEBEC THROUGH THE NRN PLAINS INTO THE ROCKIES.
THE NEXT SIGNIFICANT UPSTREAM SHORTWAVE TROUGH WAS DROPPING SOUTH
THROUGH NRN SASK/MANITOBA. AT THE SFC...1054 MB ARCTIC HIGH PRES OVER
ALBERTA EXTENDED INTO THE NRN PLAINS AND UPPER MS VALLEY AND NRN
LAKES RESULTING IN A FLOW OF VERY COLD AIR ACROSS LAKE SUPERIOR ON
NW WINDS. DESPITE 850 MB TEMPS NEAR -21C...LES HAS BEEN LIMITED BY
THE VERY DRY UPSTREAM CONDITIONS AS THE BACK EDGE OF THE CLOUDS WAS
CLOSER TO THE MI SHORE IN THE WEST AND NEAR THE CENTER OF THE NRN
LAKE. RADAR SHOWED MAINLY WEAK WIND PARALLEL BANDS INTO THE ERN
CWA.
TONIGHT...WITH THE LOSS OF DAYTIME MIXING AND ONSET OF LAND BREEZES
THE LES MAY BECOME BETTER ORGANIZED. THE PERSISTENT 290-300 FLOW LES
IS EXPECTED TO CONTINUE BUT WILL BE LIMITED BY 4K FT INVERSION
HEIGHTS AND A LACK OF ANY SUSTAINED AREAS OF LOW LEVEL CONV. THE LONGER
FETCH INTO THE EAST WILL SUPPORT SNOWFALL AMOUNTS IN THE 2 TO 4 INCH
RANGE WITH SLR VALUES NEAR 25/1...E OF MUNISING WHILE OVER THE WEST
ONLY 1 TO 3 INCH AMOUNTS ARE EXPECTED. WIND CHILL VALUES OVER THE
INTERIOR WEST COULD FALL INTO THE -20 TO -25 RANGE AS SFC TEMPS DROP
TO AROUND -8F. HOWEVER...WINDS SHOULD REMAIN LESS THAN 10 MPH.
TUESDAY...EXPECT THE WINDS TO BACK MORE WRLY AHEAD OF THE
SASK/MANITOBA SHORTWAVE TROUGH...ESPECIALLY IN THE AFTERNOON.
OTHERWISE...LIGHT TO MODERATE WNW FLOW LES WILL CONTINUE WITH 850 MB
TEMPS REMAINING NEAR -22C AND INVERSION HEIGHTS AROUND 4K FT. THE
STRONGEST LOW LEVEL CONV...INFLUENCED BY LAKE-INDUCED TROUGHING IS
EXPECTED OVER THE ERN LAKE WITH SOME STRONGER BANDS POSSIBLE
CLIPPING THE NE PORTION OF LUCE COUNTY. FOR NOW...EXPECT ADDITIONAL
ACCUMULATIONS IN THE 2 TO 4 INCH RANGE E OF P53 AND 1 TO 3 INCHES
INTO THE WEST.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 426 PM EST MON DEC 29 2014
A BROAD UPPER TROUGH OVER CANADA AND THE GREAT LAKES REGION WILL
LEAD TO BELOW NORMAL TEMPERATURES AND PERIODS OF LAKE EFFECT SNOW
THROUGH THE FIRST WEEK OF 2015.
AT THE START OF THE PERIOD...THE AREA WILL STILL BE BETWEEN A
STRONG HIGH OVER WESTERN NEBRASKA AND A LOW JUST TO THE NORTH OF
HUDSON BAY. ALOFT...A SHORTWAVE WILL JUST BE DEPARTING THE AREA AND
BRINGING ONE LAST SURGE OF -21C 850MB TEMPS TO THE AREA.
THUS...EXPECT NORTHWEST FLOW LAKE EFFECT TO STILL BE ONGOING
TUESDAY EVENING. A SURFACE TROUGH DIVING SOUTHEAST FROM THE HUDSON
BAY LOW WILL LEAD TO BACKING FLOW ON TUESDAY NIGHT INTO WEDNESDAY
MORNING...SHIFTING THE LAKE EFFECT TO THE WESTERLY FLOW AREAS (THE
KEWEEANW AND RIGHT ALONG THE LAKE SUPERIOR SHORELINE EAST OF
MUNISING). SNOWFALL AMOUNTS TUESDAY NIGHT CONTINUE TO LOOK LIGHT
AND FLUFFY AS INVERSION HEIGHTS ARE STILL IN THE 4-5KFT RANGE WITH
MUCH OF THE CLOUD LAYER IN THE DGZ. WILL FOLLOW THE SNOWFALL
AMOUNTS SEEN OVER THE LAST 12/24HRS AND HAVE THEM BE IN THE
1-4IN/12HRS RANGE.
TUESDAY NIGHT WILL BE ANOTHER COLD NIGHT AWAY FROM THE LAKE EFFECT
CLOUDS...WITH LOWS FALLING INTO THE SINGLE DIGITS AND LOWER TEENS
BELOW ZERO. WIND CHILLS WILL BECOME A CONCERN LATE IN THE NIGHT
INTO WEDNESDAY MORNING...AS THE WEST TO SOUTHWEST WINDS BEGIN TO
INCREASE WITH THE TIGHTENING PRESSURE GRADIENT. WHILE THIS WILL
LIKELY INCREASE MIXING AND IN TURN WARM TEMPS SLIGHTLY (HELPED BY
SOME MID CLOUDS MOVING IN)...THERE WILL STILL BE A PERIOD LATE
TUESDAY NIGHT INTO WEDNESDAY MORNING WHERE WIND CHILL VALUES WILL BE
IN THE -20 TO -30 DEGREE RANGE OVER THE INTERIOR LOCATIONS. WILL
CONTINUE TO MENTION THIS IN THE HWO AND AN ADVISORY MAY BEEN
NEEDED TOMORROW.
WITH THE LOW LEVEL WINDS TRYING TO BACK TOWARDS THE SOUTHWEST
DURING THE DAY WEDNESDAY...DID TRY TO SHOW BETTER TIMING ON THE
LAKE EFFECT SNOW. EXPECT IT TO TRY TO SHIFT OVER THE FAR NORTHERN
PART OF THE KEWEENAW BY MID DAY AND WELL OFFSHORE OVER THE
EAST. WINDS WILL BECOME QUITE GUSTY DURING THIS PERIOD...WITH MUCH
OF UPPER MICHIGAN EXPERIENCING GUSTS IN THE 25 TO 35MPH RANGE. BUT
OVER THE KEWEENAW PENINSULA AND CLOSER TO THE TIGHTER PRESSURE
GRADIENT...WOULD EXPECT GUSTS TO AT LEAST 40 MPH AND AT TIMES
45-50MPH. THESE WINDS COMBINED WITH THE FLUFFY LAKE EFFECT SEEN
OVER THE LAST COUPLE OF DAYS WILL LIKELY LEAD TO SIGNIFICANT
BLOWING SNOW DEVELOPING THROUGH THE DAY WEDNESDAY. THEN...AS STRONG
SHORTWAVE DIVES SOUTHEAST ACROSS THE UPPER GREAT LAKES REGION DURING
THE AFTERNOON AND THE SURFACE TROUGH DURING THE EARLY
EVENING...EXPECT WINDS TO SHIFT BACK TO THE WEST AND REFOCUS THE
LAKE EFFECT IN THE WESTERLY WIND AREAS. THINK THERE COULD BE A
PERIOD OF MODERATE SNOW AS THE WINDS TURN TO THE WEST...DUE TO
INVERSION HEIGHTS RISING TO 7KFT AND MUCH OF THE CLOUD STILL IN THE
DGZ. THERE ARE A COUPLE DOWNSIDES TO HIGHER SNOWFALL AMOUNTS (TIED
TO THE STRONG WINDS)...BUT THERE WILL STILL BE VERY POOR CONDITIONS
OVER THE KEWEENAW. FIRST...THE HIGH WINDS WILL LIMIT THE RESIDENCE
TIME OVER THE WESTERN LAKE AS THEY SHIFT TO THE WEST. SECOND...THE
STRONG WINDS WILL BREAK UP THE DENDRITES FROM THE FAVORABLE CLOUD
LAYER AND LEAD TO SMALLER/FRACTURED FLAKES. WHILE THIS WILL LIMIT
SNOWFALL AMOUNTS...IT WILL BE MORE EFFECTIVE AT REDUCING
VISIBILITIES AND WHEN COMBINED WITH THE BLOWING SNOW...WOULD EXPECT
VISIBILITIES BELOW 1/4 MILE AT TIMES LATE WEDNESDAY AFTERNOON INTO
WEDNESDAY NIGHT. WILL CONTINUE TO MENTION THESE POOR CONDITIONS FOR
THE KEWEENAW IN THE HWO.
EXPECT NORTHWEST FLOW LAKE EFFECT TO REESTABLISH ON THURSDAY FOR
AREAS DOWNSTREAM FROM LAKE SUPERIOR. ELSEWHERE IN THE U.P...MODELS
DIFFER IN THEIR SOLUTIONS ON POTENTIAL SHORTWAVES ZIPPING
EAST-SOUTHEAST ACROSS THE AREA. AT TIMES...MODELS HAVE SHOWN LIGHT
SNOW ASSOCIATED WITH THESE QUICK WAVES THURSDAY AND AGAIN FRIDAY.
BOTH STRENGTH AND LOCATIONS HAS NOT BEEN CONSISTENT IN THE MODELS
OVER THE LAST 24 HOURS...SO WILL FOCUS LARGELY ON LAKE EFFECT
TURNING TO THE WESTERLY WIND LOCATIONS AND SHOW SLIGHT CHANCES
ELSEWHERE.
THE UNCERTAINTY CONTINUES INTO THE WEEKEND...AS MODELS DIFFER ON HOW
THE CLOSED UPPER LOW THAT DEVELOPS OVER THE SOUTHWEST CONUS TUESDAY
INTERACTS WITH THE NORTHERN STREAM JET AS IT SHIFTS EAST ACROSS THE
SOUTHERN CONUS. THE 12Z GFS/GEM SOLUTIONS MERGE THE UPPER LOW WITH
A MORE AMPLIFIED NORTHERN STREAM TROUGH AND THEN LIFT IT AND A
DEVELOPING SURFACE LOW NORTHEAST THROUGH THE LOWER GREAT LAKES
SATURDAY NIGHT. MEANWHILE...THE 12Z ECMWF AND ITS ENSEMBLE MEMBERS
SHOW A MUCH FLATTER NORTHERN STREAM TROUGH AND DON/T MERGE THE
WAVES UNTIL THE EAST COAST ON SUNDAY. THAT WOULD LEAD TO MORE OF A
NORTHERLY FLOW LAKE EFFECT FOR THE AREA. THIS WILL DEFINITELY BE
SOMETHING TO WATCH OVER THE COMING DAYS. EVEN IF THERE ISN/T A LOW
MOVING THROUGH THE LOWER GREAT LAKES...TEMPERATURES WILL BE COLD
ENOUGH FOR LAKE EFFECT SNOW AND WILL CONTINUE TO SHOW THE POTENTIAL
IN THE GRIDS FOR AREAS NEAR LAKE SUPERIOR.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1133 PM EST MON DEC 29 2014
EXPECT MAINLY MVFR CONDITIONS AT IWD/CMX THROUGH THE PERIOD...WITH
BETTER CONDITIONS AT SAW. THERE COULD BE TEMPORARY IFR CONDITIONS
FOR VISIBILITY IN THE HEAVIER SNOW SHOWERS ESPECIALLY AT CMX. LIKE
LAST NIGHT...THERE WILL BE TEMPORARY MVFR CIGS AT SAW OVERNIGHT.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 403 PM EST MON DEC 29 2014
EXPECT HEAVY FREEZING SPRAY BY TUESDAY AFTERNOON AND GALES FROM LATE
TUESDAY NIGHT THROUGH THURSDAY MORNING.
A RIDGE ACROSS THE UPPER GREAT LAKES WILL BUILD TUESDAY...AS VERY
STRONG ARCTIC HIGH PRESSURE INITIALLY AT 31.3 INCHES OVER SW CANADA
SINKS ACROSS MONTANA. LOOK FOR THE RIDGE OVER LAKE SUPERIOR TO SINK
SOUTH TUESDAY NIGHT. THIS WILL BE AS A HUDSON BAY LOW DRAGS A TROUGH
ACROSS LAKE SUPERIOR. THE LOW WILL DEEPEN OVER S HUDSON BAY
WEDNESDAY NIGHT AS IT BRINGS A REINFORCING TROUGH ACROSS LAKE
SUPERIOR. W GALES OF 35-45KTS ARE STILL ANTICIPATED /ALONG WITH
HEAVY FREEZING SPRAY TUESDAY NIGHT THROUGH THURSDAY MORNING AS
THE PRESSURE GRADIENT TIGHTENS BETWEEN THE EXITING HIGH TO THE S AND
STRONG LOW TO THE N. LOOK FOR THE LOW TO SHIFT ACROSS N QUEBEC AND
WEAKEN SIGNIFICANTLY THURSDAY NIGHT. HIGH PRESSURE WILL THEN BUILD
SE ACROSS SASKATCHEWAN AND S MANITOBA ON THURSDAY AND FRIDAY AS A
RIDGE TRACKS ACROSS THE UPPER GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING FROM 1 PM EST /NOON CST/ TUESDAY TO
1 PM EST /NOON CST/ THURSDAY FOR LSZ240>243-248>251-263-
265>267.
GALE WARNING FROM 1 AM WEDNESDAY TO 1 PM EST THURSDAY FOR LSZ244-
245-264>267.
HEAVY FREEZING SPRAY WARNING FROM 7 PM EST /6 PM CST/ TUESDAY TO
7 AM EST /6 AM CST/ THURSDAY FOR LSZ162.
GALE WARNING FROM 1 AM EST /MIDNIGHT CST/ WEDNESDAY TO 7 AM EST
/6 AM CST/ THURSDAY FOR LSZ162-241>243-263.
HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST THURSDAY FOR LSZ244-
245-264.
HEAVY FREEZING SPRAY WARNING FROM 1 AM WEDNESDAY TO 1 PM EST
THURSDAY FOR LSZ246-247.
LAKE MICHIGAN...
HEAVY FREEZING SPRAY WARNING FROM 10 AM WEDNESDAY TO 1 PM EST
THURSDAY FOR LMZ221-248-250.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
341 AM CST TUE DEC 30 2014
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 332 AM CST TUE DEC 30 2014
COLDEST CORE OF AIRMASS IS OVER THE FCST AREA CURRENTLY. A SHORT
WAVE TROUGH MOVING SOUTHWARD NOW ALONG THE CANADIAN BORDER AND
BEHIND IT BEGINS SLOW WARMING AT THE 850 MB LEVEL LATER TODAY AND
TONIGHT. HOW MUCH WARMING WILL THERE BE AT THE SFC REMAINS A
QUESTION. TRENDED TOWARD HIGHER GUIDANCE VALUES AS GFS/NAM MOS
TEMPS TOO COLD AS MANY AREAS HAVE LIGHT OR MINIMAL SNOW COVER.
TO START THE DAY...THERE IS A BAND OF CLOUDS ALONG LEADING EDGE OF
THE SHORT WAVE...AND THIS WILL DROP SOUTHWARD THRU THE FCST
AREA..LASTING 2-3 HOURS AT ANY ONE PLACE. RAP MODEL 850 RH FIELD
SHOWS ITS PROGRESSION NICELY. BEHIND IT IT WILL CLEAR OUT AGAIN.
SO THE BALANCE OF THE DAY WILL SEE CONSIDERABLE SUN AND WINDS WILL
TURN A BIT MORE WESTERLY. WITH THIS IN MIND DID RAISE MAX TEMPS A
FEW DEGREES TO VERY NEAR YESTERDAY`S READINGS WITH ZERO TO 5 ABOVE
IN THE IMMEDIATE RRV AND SE ND/WCNTRL MN TO ZERO TO BELOW DVL
BASIN AND PARTS OF NW MN ESP AWAY FROM THICKEST FORESTS. HOURLY
TEMP AND WIND FCST INDICATE MOST AREAS OUT OF WC ADVISORY 18Z OR
SO SO WILL LEAVE THAT IN PLACE.
ALLOWED SOME FALL OFF IN TEMPS TONIGHT BUT NOT MUCH AS RISING
TEMPS EXPECTED ALONG WITH A BREEZY WEST WIND. WIND CHILLS SHOULD
BARELY DROP INTO THE ADV RANGE THIS EVENING BEFORE WARMING KICKS
IN. AREA OFFICES HOLDING OFF ON ANY NEW WIND CHILL ADV AS SO MUCH
DEPENDS ON HOW WARM IT GETS LATER TODAY AND HOW MUCH TEMP FALLS
EARLY THIS EVENING BEFORE SFC WARMING BEGINS.
SHORT WAVE WILL DIVE SOUTH THRU NW ONTARIO AND TOWARD MN ARROWHEAD
WEDNESDAY. THICKER CLOUD COVER LIKELY NORTH CENTRAL-NORTHEASTERN
MN WITH MORE OF A PARTLY CLOUDY REGIME FARTHER WEST. 850 TEMPS
DONT FALL MUCH WEDNESDAY SO NET RESULT WILL BE WARMER AFTN HIGHS
WITH TEENS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 332 AM CST TUE DEC 30 2014
AS ADVERTISED FOR THE PAST FEW DAYS...A WEAK SHORT WAVE WILL DIVE
SOUTHEAST FROM ALBERTA AND ACROSS NORTH DAKOTA AND INTO MINNESOTA
WED NIGHT INTO THURSDAY SPREADING A BAND OF LIGHT SNOW WITH
AMOUNTS UNDER 1 INCH.
FOR FRIDAY THROUGH TUESDAY...GFS AND ECMWF HAVE COME INTO CLOSE AGREEMENT
FOR THE START OF THE PERIOD WITH A MEAN H5 TROF AXIS EXTENDING
FROM A HUDSONS BAY LOW INTO THE EASTERN GREAT LAKES WITH A REX
BLOCK ALONG THE WESTERN NOAM COAST RESULTING IN SPLIT H5 FLOW OVER
THE CONUS...A PATTERN WHICH THEN PERSISTS THROUGH THE PERIOD. THUS
WITH NORTHWEST FLOW OVER THE NORTHERN PLAINS WE STAND A GOOD
CHANCE FOR MEASASUREABLE SNOW /A FEW INCHES/ FROM FRIDAY EVENING
INTO SATURDAY... WITH MARKEDLY COOLER TEMPS AND ADDITIONAL
FLURRIES THROUGH THE EARLY PART OF NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1127 PM CST MON DEC 29 2014
NARROW BAND OF MAINLY SCT/BKN MID LEVEL CLOUDS ASSOCIATED WITH A
WEAK BOUNDARY WILL AFFECT THE NORTH HALF OF THE FA THROUGH 12Z.
AFTER THAT NOT SURE HOW MUCH CLOUD COVER WILL BE LEFT AS MODELS
GENERALLY WASH OUT BOUNDARY.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WIND CHILL ADVISORY UNTIL NOON CST TODAY FOR NDZ006>008-014>016-
024-026>030-038-039-049-052>054.
MN...WIND CHILL ADVISORY UNTIL NOON CST TODAY FOR MNZ001>009-013>017-
022>024-027>032-040.
&&
$$
SHORT TERM...RIDDLE
LONG TERM...GUST/RIDDLE
AVIATION...VOELKER
AREA FORECAST DISCUSSION
NWS TULSA OK
1126 PM CST MON DEC 29 2014
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
VFR CIGS ALL SITES WITH LAYERED CLOUDS THROUGHOUT THE PERIOD. CIGS
BECOMING MVFR NERN OK SITES FOLLOWING COLD FRONTAL SURGE LATER
TONIGHT. CIGS PROBABLY HANG AROUND ON TUESDAY LONGER THAN
INDICATED IN MODEL FIELDS. NORTHEASTERLY WIND WILL BACK TO THE
NORTH NORTHEAST AND INCREASE WITH FRONTAL PASSAGE.
&&
.PREV DISCUSSION... /ISSUED 904 PM CST MON DEC 29 2014/
..UPDATE...
DISCUSSION...
RADAR ECHOES ARE LEAVING THE FORECAST AREA...SO WILL DROP MENTION
OF FLURRIES FOR THE REMAINDER OF THE OVERNIGHT PERIOD. 00Z
NAM...01Z HRRR AND 02Z RAP ALL APPEAR DRY FOR THE REST OF THE
NIGHT. LFM IS MISSING...ALONG WITH BAROTROPIC AND SHIP PAPA DATA.
..HAVING A RIP VAN WINKLE MOMENT...
WILL UPDATE TO TAKE OUT FLURRIES AND SPRINKLES.
APPEARS THE COLD SURGE IS STILL IN KANSAS...FROM JUST SOUTH OF MKC
TO NORTH OF ICT TO NEAR AMA...BASED MAINLY ON LOCATION OF
STRONGEST WINDS AND GUSTINESS. PROGRESS HAS BEEN SLOW...BUT ON
TARGET FOR TUESDAY MORNING.
NO CHANGE TO MINIMUM TEMPS.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
SHORT TERM...02
AVIATION...69
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
333 AM EST TUE DEC 30 2014
.SYNOPSIS...
A HIGHLY AMPLIFIED PATTERN OVER NORTH AMERICA WITH A STRONG RIDGE
OVER THE PACIFIC NORTHWEST AND A TROUGH OVER THE NORTHEAST WILL
PRODUCE TWO COLD SURGES. THE FIRST SHOULD PRODUCE COLD WEATHER
TROUGH NEW YEARS. A SOUTHERN STREAM STORM COULD BRING A WINTRY MIX
AND/OR RAIN TO THE REGION OVER THE WEEKEND AHEAD OF THE FORECAST
SECOND SURGE OF COLD CONTINENTAL AIR.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
SATELLITE IMAGERY CONTINUES TO SHOW TWO DISTINCT CLOUDS
SYSTEMS...HIGH CLOUDS PASSING TO OUR SOUTH AND LOW CLOUDS NEAR THE
NY BORDER.
HRRR SHOWS NO SIGNIFICANT SNOW AREAS OVERNIGHT...HOWEVER LATESET
RADAR IMAGERSY SHOWS BAND OF FLURRIES/LIGHT SNOW SHOWERS
MOVING SE ACROSS PARTS OF THE CENTRAL MTNS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM WEDNESDAY/...
THE HRRR ONLY GETS US TO LATE MORNING AND IT SHOWS...AT BEST SOME
FLURRIES IN SPOTS ALONG NY BORDER IN MORNING.
HIGH PRESSURE TO OUR WEST CONTINUES TO BUILD INTO THE REGION FROM
THE WEST TUESDAY. IN THIS NORTH-NORTHWEST FLOW OUR 850 MB TEMPS
FALL 2 TO 4 MORE DEGREES DURING THE DAY GETTING TO ABOUT -1SD
BELOW NORMAL BY EVENING. A COLDER THAN NORMAL DAY IS ON TAP.
THE HIGH SLIDES TO OUR SOUTH AND WEST INTO WEDNESDAY AND OUR 850
MB TEMPS BOTTOM OUT IN THE -13 TO -18C RANGE. THIS IMPLIES BETTER
CHANCE OF SOME LAKE ENHANCED SNOWS IN NORTHWESTERN AND WESTERN
MOUNTAINS. THE SNOW IN NW PA AND SW NY PEAKS IN THE SREF AFTER 00
TO 03 UTC WEDNESDAY AND BEGINS TO DIMINISH WEDNESDAY EVENING.
TRIED TO SHOW SOME SNOW UP IN THE NW AREAS BUT KEPT AMOUNT ON THE
LOW SIDE. BLENDED LARGE SCALE MODELS WITH 21Z SREF TO REFINE THE
AREA OF POPS AND QPF. QPF AMOUNTS WERE OF COURSE LOW.
CLEARLY WEDNESDAY SHOULD BE ABOUT THE COLDEST DAY OF THE WINTER
TO DATE WITH THE -16C CONTOUR DRAPED OVER CENTRAL PA AND AT LEAST
-1SD BELOW NORMAL TEMPERATURES. THAT IS 5 TO 10F BELOW NORMAL.
THE COLD AT LEAST WILL CONTINUE INTO NEW YEARS DAY (SEE BELOW) AS
THE HIGH LUMBERS BY TO OUR SOUTH.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
STRONG HIGH PRESSURE OVER THE CENTRAL U.S. THIS MIDWEEK WILL
WEAKEN AND DRIFT TOWARD THE CAROLINAS BY FRIDAY AS A WEAK WAVE
SLIDES QUICKLY ACROSS THE GREAT LAKES. THIS WILL BRING AN
EXTENDED PERIOD OF FAIR BUT COOLER THAN NORMAL WEATHER TO THE
FORECAST AREA. SOME SNOW SHOWERS MAY IMPACT THE NW MTNS...BUT
MOST OF THE SNOW SHOWER ACTIVITY WILL REMAIN NORTH OF THE PA
BORDER. BREEZY CONDITIONS WED NIGHT INTO THU IN FAST FLOW WILL
RESULT IN SINGLE DIGIT WIND CHILLS OVER NORTHERN AND WESTERN PARTS
OF THE CWA AS WE RING IN THE NEW YEAR.
GEFS AND OTHER LONG RANGE GUIDANCE SHOW THE FIRST NOTABLE STORM
OF 2015 DEVELOPING FOR NEXT WEEKEND. TIMING/STORM TRACK ISSUES
REMAIN WITH MUCH UNCERTAINTY IN EVOLUTION OF THIS SYSTEM...BUT
GUIDANCE IMPLIES A POTENTIAL MIXED PRECIPITATION EVENT FROM
GENERALLY SAT AFT THROUGH FIRST HALF OF SUNDAY. GFS CONTINUES TO
BRINGS A LOW UP THE OHIO VALLEY TO OUR WEST...PUSHING A SHOT OF
MILDER AIR BACK INTO THE STATE WITH RAIN LIKELY BECOMING THE MOST
DOMINANT PRECIPITATION TYPE /WITH FREEZING PRECIP POSS AT ONSET/.
IN CONTRAST...THE OPERATIONAL ECMWF REMAINING FIRM ON BRINGING
THE SURFACE LOW SOUTH AND EAST OF PA WHICH WOULD RESULT IN COLDER
AIR AND A MORE MIXED BAG OF PRECIPITATION TYPES AND PERHAPS SNOW
IN NORTHERN AND SOME CENTRAL AREAS. THE EC MEAN IS A BIT MORE
AGGRESSIVE DEVELOPING THE LOW...POTENTIALLY MAKING THE OPERATIONAL
RUN AN OUTLIER. FOR NOW...DIDN/T MAKE ANY LARGE CHANGES TO
FORECAST OVER THE WEEKEND AND HELD ON TO THE POTENTIAL FOR A MIX
OF WINTRY PRECIP - ESP ACROSS CENTRAL AND NORTHERN PA...AND LEANED
MORE TOWARD RAIN IN THE LOWER SUSQ.
QUICK SHOT OF COLDER AIR TO START NEXT WEEK...WITH CHANCE FOR
ANOTHER LOW SLIDING EASTWARD FROM THE GREAT LAKES INTO NEW ENGLAND
MIDWEEK WITH CHANCE OF SNOW FOR PA.
&&
.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
MVFR CIGS WILL LIKELY REMAIN IN PLACE AT BFD INTO TUESDAY WITH
NORTHWESTERLY WINDS AND A CHILLY...SHALLOW AIR MASS. CONTINUED
NORTHWESTERLY FLOW WILL MAKE A FEW FLURRIES AT BFD...BUT THE REST
OF THE TERMINALS WILL REMAIN DRY AND ONLY JST MAY SEE MVFR CIGS
OVERNIGHT. CLOUDS MAY LOWER AT IPT/UNV AS THE LOW CLOUD DECK
ASSOCIATED WITH THE COLDER AIR SLIDING DOWN FROM THE NORTH MOVES
SOUTHWARD. BUT...WILL KEEP IT AS VFR THRU THE TAF PERIOD FOR THE
TIME BEING.
HIGH PRESSURE CENTERED OVER THE FRONT RANGE OF THE ROCKIES AND THE
GREAT PLAINS WILL STRETCH FAR TO THE EAST AND GRADUALLY SINK
SOUTHWARD. A BRIEF SHOT OF COLDER AIR WITHIN A FEW HOURS OF 12Z
WED MAY CREATE A BROADER AREA OF SHSN/SQ. BUT THE REDUCTIONS IN
VIS/CIG SHOULD BE LIMITED TO BFD...AND NOT EVEN JST. THE WAVE
ALOFT WILL BE ACCOMPANIED BY VERY LITTLE MOISTURE. WINDS COULD
BECOME GUSTY...THOUGH.
OUTLOOK...
WED-FRI...VFR.
SAT...MVFR/IFR POSS IN WINTRY PRECIP.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...GRUMM/GARTNER
NEAR TERM...GRUMM/GARTNER
SHORT TERM...GRUMM
LONG TERM...RXR
AVIATION...DANGELO/CERU/GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
217 AM EST TUE DEC 30 2014
.SYNOPSIS...
A HIGHLY AMPLIFIED PATTERN OVER NORTH AMERICA WITH A STRONG RIDGE
OVER THE PACIFIC NORTHWEST AND A TROUGH OVER THE NORTHEAST WILL
PRODUCE TWO COLD SURGES. THE FIRST SHOULD PRODUCE COLD WEATHER
TROUGH NEW YEARS. A SOUTHERN STREAM STORM COULD BRING A WINTRY MIX
AND/OR RAIN TO THE REGION OVER THE WEEKEND AHEAD OF THE FORECAST
SECOND SURGE OF COLD CONTINENTAL AIR.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
SATELLITE IMAGERY CONTINUES TO SHOW TWO DISTINCT CLOUDS
SYSTEMS...HIGH CLOUDS PASSING TO OUR SOUTH AND LOW CLOUDS NEAR THE
NY BORDER. HRRR SUGGESTS OUR FORECASTS IN SOUTH/CENTRAL ARE TOO
CLOUDY.
HRRR ALSO SHOWS NO SIGNIFICANT SNOW AREAS OVERNIGHT IN NORTHWEST.
THE WEAK NORTHWEST FLOW OUT OF THE HIGH CENTERED OVER THE TN
VALLEY DOES NOT CAUSE THE MODEL TO GENERATE ANY LAKE ENHANCED
SNOWS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM WEDNESDAY/...
THE HRRR ONLY GETS US TO LATE MORNING AND IT SHOWS...AT BEST SOME
FLURRIES IN SPOTS ALONG NY BORDER IN MORNING.
HIGH PRESSURE TO OUR WEST CONTINUES TO BUILD INTO THE REGION FROM
THE WEST TUESDAY. IN THIS NORTH-NORTHWEST FLOW OUR 850 MB TEMPS
FALL 2 TO 4 MORE DEGREES DURING THE DAY GETTING TO ABOUT -1SD
BELOW NORMAL BY EVENING. A COLDER THAN NORMAL DAY IS ON TAP.
THE HIGH SLIDES TO OUR SOUTH AND WEST INTO WEDNESDAY AND OUR 850
MB TEMPS BOTTOM OUT IN THE -13 TO -18C RANGE. THIS IMPLIES BETTER
CHANCE OF SOME LAKE ENHANCED SNOWS IN NORTHWESTERN AND WESTERN
MOUNTAINS. THE SNOW IN NW PA AND SW NY PEAKS IN THE SREF AFTER 00
TO 03 UTC WEDNESDAY AND BEGINS TO DIMINISH WEDNESDAY EVENING.
TRIED TO SHOW SOME SNOW UP IN THE NW AREAS BUT KEPT AMOUNT ON THE
LOW SIDE. BLENDED LARGE SCALE MODELS WITH 21Z SREF TO REFINE THE
AREA OF POPS AND QPF. QPF AMOUNTS WERE OF COURSE LOW.
CLEARLY WEDNESDAY SHOULD BE ABOUT THE COLDEST DAY OF THE WINTER
TO DATE WITH THE -16C CONTOUR DRAPED OVER CENTRAL PA AND AT LEAST
-1SD BELOW NORMAL TEMPERATURES. THAT IS 5 TO 10F BELOW NORMAL.
THE COLD AT LEAST WILL CONTINUE INTO NEW YEARS DAY (SEE BELOW) AS
THE HIGH LUMBERS BY TO OUR SOUTH.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
STRONG HIGH PRESSURE OVER THE CENTRAL U.S. THIS MIDWEEK WILL
WEAKEN AND DRIFT TOWARD THE CAROLINAS BY FRIDAY AS A WEAK WAVE
SLIDES QUICKLY ACROSS THE GREAT LAKES. THIS WILL BRING AN
EXTENDED PERIOD OF FAIR BUT COOLER THAN NORMAL WEATHER TO THE
FORECAST AREA. SOME SNOW SHOWERS MAY IMPACT THE NW MTNS...BUT
MOST OF THE SNOW SHOWER ACTIVITY WILL REMAIN NORTH OF THE PA
BORDER. BREEZY CONDITIONS WED NIGHT INTO THU IN FAST FLOW WILL
RESULT IN SINGLE DIGIT WIND CHILLS OVER NORTHERN AND WESTERN PARTS
OF THE CWA AS WE RING IN THE NEW YEAR.
GEFS AND OTHER LONG RANGE GUIDANCE SHOW THE FIRST NOTABLE STORM
OF 2015 DEVELOPING FOR NEXT WEEKEND. TIMING/STORM TRACK ISSUES
REMAIN WITH MUCH UNCERTAINTY IN EVOLUTION OF THIS SYSTEM...BUT
GUIDANCE IMPLIES A POTENTIAL MIXED PRECIPITATION EVENT FROM
GENERALLY SAT AFT THROUGH FIRST HALF OF SUNDAY. GFS CONTINUES TO
BRINGS A LOW UP THE OHIO VALLEY TO OUR WEST...PUSHING A SHOT OF
MILDER AIR BACK INTO THE STATE WITH RAIN LIKELY BECOMING THE MOST
DOMINANT PRECIPITATION TYPE /WITH FREEZING PRECIP POSS AT ONSET/.
IN CONTRAST...THE OPERATIONAL ECMWF REMAINING FIRM ON BRINGING
THE SURFACE LOW SOUTH AND EAST OF PA WHICH WOULD RESULT IN COLDER
AIR AND A MORE MIXED BAG OF PRECIPITATION TYPES AND PERHAPS SNOW
IN NORTHERN AND SOME CENTRAL AREAS. THE EC MEAN IS A BIT MORE
AGGRESSIVE DEVELOPING THE LOW...POTENTIALLY MAKING THE OPERATIONAL
RUN AN OUTLIER. FOR NOW...DIDN/T MAKE ANY LARGE CHANGES TO
FORECAST OVER THE WEEKEND AND HELD ON TO THE POTENTIAL FOR A MIX
OF WINTRY PRECIP - ESP ACROSS CENTRAL AND NORTHERN PA...AND LEANED
MORE TOWARD RAIN IN THE LOWER SUSQ.
QUICK SHOT OF COLDER AIR TO START NEXT WEEK...WITH CHANCE FOR
ANOTHER LOW SLIDING EASTWARD FROM THE GREAT LAKES INTO NEW ENGLAND
MIDWEEK WITH CHANCE OF SNOW FOR PA.
&&
.AVIATION /07Z TUESDAY THROUGH SATURDAY/...
MVFR CIGS WILL LIKELY REMAIN IN PLACE AT BFD INTO TUESDAY WITH
NORTHWESTERLY WINDS AND A CHILLY...SHALLOW AIR MASS. CONTINUED
NORTHWESTERLY FLOW WILL MAKE A FEW FLURRIES AT BFD...BUT THE REST
OF THE TERMINALS WILL REMAIN DRY AND ONLY JST MAY SEE MVFR CIGS
OVERNIGHT. CLOUDS MAY LOWER AT IPT/UNV AS THE LOW CLOUD DECK
ASSOCIATED WITH THE COLDER AIR SLIDING DOWN FROM THE NORTH MOVES
SOUTHWARD. BUT...WILL KEEP IT AS VFR THRU THE TAF PERIOD FOR THE
TIME BEING.
HIGH PRESSURE CENTERED OVER THE FRONT RANGE OF THE ROCKIES AND THE
GREAT PLAINS WILL STRETCH FAR TO THE EAST AND GRADUALLY SINK
SOUTHWARD. A BRIEF SHOT OF COLDER AIR WITHIN A FEW HOURS OF 12Z
WED MAY CREATE A BROADER AREA OF SHSN/SQ. BUT THE REDUCTIONS IN
VIS/CIG SHOULD BE LIMITED TO BFD...AND NOT EVEN JST. THE WAVE
ALOFT WILL BE ACCOMPANIED BY VERY LITTLE MOISTURE. WINDS COULD
BECOME GUSTY...THOUGH.
OUTLOOK...
WED-FRI...VFR.
SAT...MVFR/IFR POSS IN WINTRY PRECIP.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...GRUMM/GARTNER
NEAR TERM...GRUMM/GARTNER
SHORT TERM...GRUMM
LONG TERM...RXR
AVIATION...DANGELO/CERU/GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
109 AM EST TUE DEC 30 2014
.SYNOPSIS...
A HIGHLY AMPLIFIED PATTERN OVER NORTH AMERICA WITH A STRONG RIDGE
OVER THE PACIFIC NORTHWEST AND A TROUGH OVER THE NORTHEAST WILL
PRODUCE TWO COLD SURGES. THE FIRST SHOULD PRODUCE COLD WEATHER
TROUGH NEW YEARS. A SOUTHERN STREAM STORM COULD BRING A WINTRY MIX
AND/OR RAIN TO THE REGION OVER THE WEEKEND AHEAD OF THE FORECAST
SECOND SURGE OF COLD CONTINENTAL AIR.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
SATELLITE IMAGERY CONTINUES TO SHOW TWO DISTINCT CLOUDS
SYSTEMS...HIGH CLOUDS PASSING TO OUR SOUTH AND LOW CLOUDS NEAR THE
NY BORDER. HRRR SUGGESTS OUR FORECASTS IN SOUTH/CENTRAL ARE TOO
CLOUDY.
HRRR ALSO SHOWS NO SIGNIFICANT SNOW AREAS OVERNIGHT IN NORTHWEST.
THE WEAK NORTHWEST FLOW OUT OF THE HIGH CENTERED OVER THE TN
VALLEY DOES NOT CAUSE THE MODEL TO GENERATE ANY LAKE ENHANCED
SNOWS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM WEDNESDAY/...
THE HRRR ONLY GETS US TO LATE MORNING AND IT SHOWS...AT BEST SOME
FLURRIES IN SPOTS ALONG NY BORDER IN MORNING.
HIGH PRESSURE TO OUR WEST CONTINUES TO BUILD INTO THE REGION FROM
THE WEST TUESDAY. IN THIS NORTH-NORTHWEST FLOW OUR 850 MB TEMPS
FALL 2 TO 4 MORE DEGREES DURING THE DAY GETTING TO ABOUT -1SD
BELOW NORMAL BY EVENING. A COLDER THAN NORMAL DAY IS ON TAP.
THE HIGH SLIDES TO OUR SOUTH AND WEST INTO WEDNESDAY AND OUR 850
MB TEMPS BOTTOM OUT IN THE -13 TO -18C RANGE. THIS IMPLIES BETTER
CHANCE OF SOME LAKE ENHANCED SNOWS IN NORTHWESTERN AND WESTERN
MOUNTAINS. THE SNOW IN NW PA AND SW NY PEAKS IN THE SREF AFTER 00
TO 03 UTC WEDNESDAY AND BEGINS TO DIMINISH WEDNESDAY EVENING.
TRIED TO SHOW SOME SNOW UP IN THE NW AREAS BUT KEPT AMOUNT ON THE
LOW SIDE. BLENDED LARGE SCALE MODELS WITH 21Z SREF TO REFINE THE
AREA OF POPS AND QPF. QPF AMOUNTS WERE OF COURSE LOW.
CLEARLY WEDNESDAY SHOULD BE ABOUT THE COLDEST DAY OF THE WINTER
TO DATE WITH THE -16C CONTOUR DRAPED OVER CENTRAL PA AND AT LEAST
-1SD BELOW NORMAL TEMPERATURES. THAT IS 5 TO 10F BELOW NORMAL.
THE COLD AT LEAST WILL CONTINUE INTO NEW YEARS DAY (SEE BELOW) AS
THE HIGH LUMBERS BY TO OUR SOUTH.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
STRONG HIGH PRESSURE OVER THE CENTRAL U.S. THIS MIDWEEK WILL
WEAKEN AND DRIFT TOWARD THE CAROLINAS BY FRIDAY AS A WEAK WAVE
SLIDES QUICKLY ACROSS THE GREAT LAKES. THIS WILL BRING AN
EXTENDED PERIOD OF FAIR BUT COOLER THAN NORMAL WEATHER TO THE
FORECAST AREA. SOME SNOW SHOWERS MAY IMPACT THE NW MTNS...BUT
MOST OF THE SNOW SHOWER ACTIVITY WILL REMAIN NORTH OF THE PA
BORDER. BREEZY CONDITIONS WED NIGHT INTO THU IN FAST FLOW WILL
RESULT IN SINGLE DIGIT WIND CHILLS OVER NORTHERN AND WESTERN PARTS
OF THE CWA AS WE RING IN THE NEW YEAR.
GEFS AND OTHER LONG RANGE GUIDANCE SHOW THE FIRST NOTABLE STORM
OF 2015 DEVELOPING FOR NEXT WEEKEND. TIMING/STORM TRACK ISSUES
REMAIN WITH MUCH UNCERTAINTY IN EVOLUTION OF THIS SYSTEM...BUT
GUIDANCE IMPLIES A POTENTIAL MIXED PRECIPITATION EVENT FROM
GENERALLY SAT AFT THROUGH FIRST HALF OF SUNDAY. GFS CONTINUES TO
BRINGS A LOW UP THE OHIO VALLEY TO OUR WEST...PUSHING A SHOT OF
MILDER AIR BACK INTO THE STATE WITH RAIN LIKELY BECOMING THE MOST
DOMINANT PRECIPITATION TYPE /WITH FREEZING PRECIP POSS AT ONSET/.
IN CONTRAST...THE OPERATIONAL ECMWF REMAINING FIRM ON BRINGING
THE SURFACE LOW SOUTH AND EAST OF PA WHICH WOULD RESULT IN COLDER
AIR AND A MORE MIXED BAG OF PRECIPITATION TYPES AND PERHAPS SNOW
IN NORTHERN AND SOME CENTRAL AREAS. THE EC MEAN IS A BIT MORE
AGGRESSIVE DEVELOPING THE LOW...POTENTIALLY MAKING THE OPERATIONAL
RUN AN OUTLIER. FOR NOW...DIDN/T MAKE ANY LARGE CHANGES TO
FORECAST OVER THE WEEKEND AND HELD ON TO THE POTENTIAL FOR A MIX
OF WINTRY PRECIP - ESP ACROSS CENTRAL AND NORTHERN PA...AND LEANED
MORE TOWARD RAIN IN THE LOWER SUSQ.
QUICK SHOT OF COLDER AIR TO START NEXT WEEK...WITH CHANCE FOR
ANOTHER LOW SLIDING EASTWARD FROM THE GREAT LAKES INTO NEW ENGLAND
MIDWEEK WITH CHANCE OF SNOW FOR PA.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
MVFR CIGS WILL LIKELY REMAIN IN PLACE AT BFD INTO TUESDAY WITH
NORTHWESTERLY WINDS AND A CHILLY...SHALLOW AIR MASS. CONTINUED
NORTHWESTERLY FLOW WILL MAKE A FEW FLURRIES AT BFD...BUT THE REST
OF THE TERMINALS WILL REMAIN DRY AND ONLY JST MAY SEE MVFR CIGS
OVERNIGHT. CLOUDS MAY LOWER AT IPT/UNV AS THE LOW CLOUD DECK
ASSOCIATED WITH THE COLDER AIR SLIDING DOWN FROM THE NORTH MOVES
SOUTHWARD. BUT...WILL KEEP IT AS VFR THRU THE TAF PERIOD FOR THE
TIME BEING.
HIGH PRESSURE CENTERED OVER THE FRONT RANGE OF THE ROCKIES AND THE
GREAT PLAINS WILL STRETCH FAR TO THE EAST AND GRADUALLY SINK
SOUTHWARD. A BRIEF SHOT OF COLDER AIR WITHIN A FEW HOURS OF 12Z
WED MAY CREATE A BROADER AREA OF SHSN/SQ. BUT THE REDUCTIONS IN
VIS/CIG SHOULD BE LIMITED TO BFD...AND NOT EVEN JST. THE WAVE
ALOFT WILL BE ACCOMPANIED BY VERY LITTLE MOISTURE. WINDS COULD
BECOME GUSTY...THOUGH.
OUTLOOK...
WED-FRI...VFR.
SAT...MVFR/IFR POSS IN WINTRY PRECIP.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...GRUMM/GARTNER
NEAR TERM...GRUMM/GARTNER
SHORT TERM...GRUMM
LONG TERM...RXR
AVIATION...DANGELO/GARTNER
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1152 PM EST MON DEC 29 2014
.SYNOPSIS...
COLD SURFACE HIGH PRESSURE WILL CONTINUE TO WEDGE DOWN FROM THE
NORTH ALONG THE APPALACHIANS TONIGHT WHILE A WEAK UPPER LEVEL
DISTURBANCE IS EXPECTED TO PASS FROM WEST TO EAST ACROSS THE AREA
TONIGHT THROUGH EARLY TUESDAY. VERY LIGHT PRECIPITATION ASSOCIATED
WITH THIS FEATURE IS EXPECTED TO CHANGE OVER TO SNOW ACROSS THE
NORTHERN PORTION OF THE REGION...WITH ACCUMULATIONS OF AN INCH OR
LESS...MAINLY ALONG AND NORTH OF U.S. 460. DRY BUT CONTINUED COLD
HIGH PRESSURE WILL BEGIN TO PUSH IN FROM THE WEST LATER TUESDAY
AND LAST UNTIL LATE IN THE WEEK.
&&
.NEAR TERM /THROUGH TUESDAY/...
AS OF 635 PM EST MONDAY...
MADE A FEW MINOR ADJUSTMENTS TO EXISTING SET OF GRIDS TO BUMP UP
PROBABILITY OF PRECIPITATION TO ACCOUNT FOR WIDESPREAD RAIN AND
DRIZZLE NOW FALLING ACROSS MUCH OF THE NEW RIVER VALLEY NORTH
TOWARD THE ALLEGHANY HIGHLANDS. DESPITE AREAL EXTENT OF
PRECIPITATION...AMOUNTS CONTINUE TO BE LIGHT...GENERALLY ONLY
AROUND 0.01 INCH/PER HOUR.
LATEST UPPER-AIR SOUNDING...RELEASED ABOUT 30 MINUTES AGO...SHOWS
LOWEST 3K FEET AGL STILL ABOVE FREEZING AND NEARLY SATURATED...SO
IT WILL TAKE MUCH OF THE EVENING...PERHAPS INTO THE EARLY MORNING
HOURS...TO DRIVE SNOW LEVELS DOWN FROM HIGHEST RIDGES TO MOUNTAIN
VALLEY AREAS...CONSISTENT WITH PREVIOUS FORECAST THINKING.
THEREFORE...SNOWFALL TOTALS STILL NOT EXPECTED TO BECOME
PROBLEMATIC AS THE NIGHT PROGRESSES...ESPECIALLY CONSIDERING
CURRENT WARM GROUND CONDITIONS AND VERY LIGHT FALL RATES.
ALSO MADE A FEW TWEAKS TO HOURLY TEMPS/DEW POINT GRIDS TO REFLECT
LATEST MESONET OBSERVATIONS...OTHERWISE REST OF FORECAST FOR
TONIGHT STILL LOOKS RIGHT ON TARGET.
AS OF 350 PM EST MONDAY...
TRICKY FCST OVERNIGHT IN REGARDS TO THE AMOUNTS AND LOCATIONS OF
VERY LIGHT PCPN AS A WEAK UPPER WAVE PASSES OVER THE DEEPENING
COLD AIR DAMMING WEDGE AS COLD SFC HIGH PRESSURE SPILLS DOWN FROM
THE NORTH. MODEL GUIDANCE ALL QUITE DIFFERENT WITH MAIN
OPERATIONAL NCEP MODELS TRENDING UPWARD SOMEWHAT WITH AS MUCH AS A
QUARTER TO TWO THIRDS OF AN INCH LIQUID EQUIV...MAINLY OVER THE
WESTERN PORTIONS. EVEN ORIGINALLY DRIER GFS NOW AS MUCH AS FOUR
TENTHS OF AN INCH OVER THE ALLEGHANY HIGHLANDS. MEANWHILE
CONVECTIVE-ALLOWING MODELS GENERALLY LESS THAN TWO TENTHS OF AN
INCH. AM LEANING ON THE LIGHT SIDE OF THE QPF OPTIONS...MORE IN
LINE WITH IDEA OF MOST OF THE HRRR RUNS...AND POSSIBILITY THAT
MORE OF THE PCPN ACTUALLY ENDS UP BACK ACROSS THE FOOTHILLS AND
PIEDMONT AGAIN. AM LEAVING SOME VERY LOW LIKELY POPS FOR TONIGHT
ACROSS PARTS OF THE MOUNTAINS...WITH HIGHER CHANCE POPS NOW ACROSS
THE FOOTHILLS. THE ISSUE OF MOISTURE DEPTH IS STILL CONCERN AS
WELL...AND WHILE I DID NOT INCLUDE ANY DRIZZLE IN THE
GRIDS...THERE COULD VERY WELL BE PERIODS OF TIME AND PORTIONS OF
THE AREA WHERE WE SEE MORE DRIZZLE DUE TO LACK OF ICE CRYSTAL
GROWTH ALOFT. THIS WOULD CUT DOWN ON ANY OF THE ALREADY LIGHT SNOW
ACCUMS IF AND WHERE THIS HAPPENS. WARM NOSE DOES NOT SEEM TO BE
PRESENT IN ANY MODEL SOUNDINGS...SO GOING WITH EITHER RAIN OR
SNOW...AND SO SFC TEMPS WILL BE THE KEY TO THAT CHANGEOVER. AS FAR
AS THE TEMPS GO...ALREADY GETTING COLDER THIS AFTERNOON THAN WE
EARLIER ANTICIPATED...AND SOME HIGHER ELEVATIONS HAVE REPORTS SOME
VERY LIGHT SNOW. THUS LOWERED TEMPS THROUGH EVENING AND OVERNIGHT
A FEW DEGREES FROM PREVIOUS FORECAST WHERE WEDGE IS EXPECTED TO BE
THE STRONGEST...AND THIS RESULTS IN A SLIGHTLY EARLIER CHANGEOVER
FROM LIGHT RAIN TO LIGHT SNOW...BUT EXCEPT FOR HIGHER
ELEVATIONS...THIS WILL STILL BE AFTER MIDNIGHT.
BOTTOM LINE IS ONLY VERY LIGHT AMOUNTS OF SNOW ACCUM
EXPECTED LATE TONIGHT AND IN THE EARLY MORNING HOURS TUESDAY...AND
IT WILL LIKELY HAVE TROUBLE STICKING AS WELL EXCEPT FOR HIGHEST
ELEVATIONS. HAVE DUSTING TO LESS THAN AN INCH GENERALLY NORTH OF
U.S. 460...AND DOWN THE BLUE RIDGE TO NEAR MEADOWS OF DAN. MAYBE
AN INCH TO ALMOST TWO ALONG HIGHEST RIDGES OF ALLEGHANY HIGHLANDS
AND ALONG BLUE RIDGE PARKWAY NORTH OF PEAKS OF OTTER. MOST ROADS
NOT EXPECTED TO SEE ANY ACCUMULATION.
ANY LINGERING PCPN EVAPORATES QUICKLY BY MIDDAY TUESDAY AS SHORT
WAVE PASSES BY AND DRIER AIR FROM NORTH CONTINUES TO FILTER IN.
WESTERLY FLOW AT RIDGE TOP LEVEL DEVELOPS BUT VERY WEAK FLOW AND
LITTLE MOISTURE TO WORK WITH SO NO ISSUES WITH ANY UPSLOPE SNOW
SHOWERS IN FAR WEST IT APPEARS. MAX TEMPS MAY BE TRICKY WITH SOME
SUNSHINE LATE IN THE DAY...BUT THIS COULD BE TOO LATE FOR LOW SUN
ANGLE TO HAVE MUCH IMPACT...SO FOR NOW GOING ON COLD SIDE OF
GUIDANCE WITH ONLY ABOUT A 5-7 DEGREE RISE FROM OVERNIGHT LOWS.
ABOVE FREEZING BY LATE MORNING SO ANY MINOR AMOUNTS OF SNOW THAT
DOES FALL WILL BE GONE BY NOON MOST LIKELY.
FINALLY...COLD WEDGE WILL KEEP SOME AREAS OF FOG AND LOW CEILINGS
AROUND...MOST ESPECIALLY NEAR THE BLUE RIDGE...BUT ALSO SOME OF
THE MTN VALLEYS AS WELL...SO BLANKED THE FOOTHILLS AND WESTWARD
WITH PATCHY FOG THROUGH TOMORROW MORNING IN THE FORECAST GRIDS BUT THIS
MAY LINGER THROUGH MUCH OF THE DAY IN SPOTS UNTIL THE WEAK WESTERLY
FLOW CAN PUSH EAST.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
AS OF 200 PM EST MONDAY...
A LARGE AREA OF HIGH PRESSURE WILL BUILD SOUTH FROM THE ROCKIES LATE
TUESDAY...THEN INTO THE SOUTHEAST U.S. BY THURSDAY EVENING KEEPING
DRY WEATHER FOR OUR AREA DURING THIS PORTION OF THE FORECAST.
ADJUSTED TEMPS DOWN A FEW DEGREES WEDNESDAY MORNING AND WEDNESDAY
AFTERNOON UNDER GOOD COLD AIR ADVECTION. BY THURSDAY MORNING
MODELS ARE IN GOOD AGREEMENT THAT SFC HIGH NOSES INTO OUR
AREA ALLOWING VALLEY WINDS TO DIMINISH. THIS COMBINED WITH THE
DRY AIR MASS IN PLACE SHOULD ALLOW TEMPS TO DROP BELOW GUIDANCE
VALUES. THE EXCEPTION WILL BE ON THE RIDGETOPS WHERE 850MB WINDS
WILL KEEP TEMPS WARMER.
HEIGHTS RISE ON THURSDAY AS AN UPPER RIDGE BEGINS TO BUILD IN THE
CENTRAL U.S. IN ADVANCE OF A SOUTHWEST U.S. UPPER LOW.
THIS...COMBINED WITH DOWNSLOPING WINDS...SHOULD ALLOW FOR A NICE
RECOVERY IN TEMPS THURSDAY. WENT A DEGREE OR TWO ABOVE GUIDANCE FOR
HIGHS.
ONLY OTHER CHANGE TO THE FORECAST WAS TO INCREASE THE WINDS ABOVE
3500 FEET WEDNESDAY AND THURSDAY AS A SWIFT MOVING NORTHERN STREAM
SHORTWAVE PASSES THROUGH THE EASTERN GREAT LAKES THROUGH NEW ENGLAND
DURING THIS TIME.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 235 PM EST MONDAY...
DRY AND SEASONABLY COOL WEATHER IS EXPECTED OVER THE BLACKSBURG
FORECAST AREA FRIDAY MORNING AS A WEAK SHORT WAVE IN NORTHERN STREAM
SCOOTS EAST THROUGH NEW ENGLAND...WITH COOL HIGH PRESSURE BUILDING
SOUTHWESTWARD IN ITS WAKE.
HOWEVER...MUCH OF THE REST OF THE LONG TERM FORECAST FROM FRIDAY
AFTERNOON INTO MONDAY APPEARS TO BE MUCH MORE UNCERTAIN...WITH
SIGNIFICANT AND PERSISTENT DISPARITY EXISTING BETWEEN THE LONGER-
TERM MODELS IN REFLECTING STRENGTH AND PLACEMENT OF NORTHERN
STREAM...AND ITS INFLUENCE ON SOUTHERN STREAM CLOSED LOW SOUTH OF
THE FOUR CORNERS AREA ON FRIDAY AFTERNOON THAT IS FORECAST TO
GRADUALLY LIFT NORTHEAST AND FILL AS IT PROGRESSES FROM THE SOUTHERN
PLAINS UP THROUGH THE OHIO VALLEY OVER THE WEEKEND.
ECMWF MAINTAINS A MORE PERSISTENT CLOSED UPPER LOW THAT IS MUCH LESS
AMPLIFIED...YET LESS PROGRESSIVE AND FURTHER SOUTH...RESULTING IN
INCREASING ISENTROPIC LIFT AND RAIN MOVING INTO AT LEAST THE
SOUTHWESTERN HALF OF THE BLACKSBURG FORECAST AREA BY/DURING FRIDAY
AFTERNOON...BUT NOT ENDING UNTIL PASSAGE OF OPENING/WEAKENING UPPER
TROF ON SUNDAY NIGHT.
GFS...WHICH REFLECTS A MORE AMPLIFIED...YET EVENTUALLY MORE
PROGRESSIVE AND NORTHERN SYSTEM PLACEMENT...HOLDS BACK RAIN SHIELD
UNTIL SATURDAY DUE TO INFLUENCE OF LARGER AND STRONGER DRY SURFACE
HIGH PRESSURE SYSTEM OVER NEW ENGLAND. GFS ALSO THE COLDER OF THE
LONGER RANGE SOLUTIONS...SINCE STRONGER SURFACE RIDGE TO NORTHEAST
WOULD LOCK COOL-WEDGE IN PLACE OVER THE BLACKSBURG FORECAST AREA.
HOWEVER...BEING MORE PROGRESSIVE...RAIN EVENT ENDS A BIT EARLIER
THAN ECMWF SOLUTION...ON SUNDAY AFTERNOON WITH PASSAGE OF UPPER
TROF...BUT WITH PERHAPS SOME COLD ADVECTION UPSLOPE PRECIPITATION
CONTINUING ACROSS THE WESTERN FLANKS OF THE APPALACHIANS UNTIL
AROUND DAYBREAK MONDAY.
BOTH MODELS HAVE BEEN INCONSISTENT IN TIMING AND PLACEMENT OF SYSTEM
THOUGH THIS TIME FRAME FOR AT LEAST THE PAST SEVERAL
RUNS...WHICH IS NOT ALL THAT SURPRISING CONSIDERING ACTIVE
NORTHERN STREAM CLASHING WITH INITIALLY CLOSED AND STAGNANT
SOUTHERN STREAM SYSTEM...SO MODEL BLEND/ENSEMBLE APPROACH BEST TO
APPLY FOR LONG TERM FORECAST UNTIL CONFIDENCE INCREASES IN MOVING
TOWARD ANY PARTICULAR SOLUTION.
NEITHER MODEL INDICATING THAT THICKNESSES WILL BE ESPECIALLY
CRITICAL FOR P-TYPE ISSUES...MEANING A MAINLY WET RATHER THAN WHITE
FORECAST OVER THE WEEKEND. HOWEVER...IF COLDER GFS SOLUTION
VERIFIES...THICKNESSES MAY BE CLOSE ENOUGH TO CRITICAL VALUES NORTH
OF HIGHWAY 64 TO WARRANT AT LEAST A NOMINAL INSERTION OF A P-TYPE
MIX DURING TIME OF PRECIPITATION ONSET...AND PERHAPS FOLLOWING
PASSAGE OF MAIN SYSTEM IN THE NORTHWESTERN MOUNTAINS ON SUNDAY NIGHT
PROVIDED THAT POST FRONTAL COLD ADVECTION IS SUFFICIENTLY STRONG.
REGARDLESS OF TIMING AND PLACEMENT DIFFERENCES...ALL LONGER RANGE
MODELS INDICATE THAT MONDAY WILL BE DRY FOLLOWING PASSAGE OF THE
MAIN UPPER SYSTEM...WITH ANY ADDITION SOUTHERN STREAM ENERGY LIKELY
TO BE DEFLECTED TO OUR SOUTH AS NORTHERN STREAM TROFING GRADUALLY
STRENGTHENS AND AMPLIFIES FROM THE UPPER GREAT LAKES EAST INTO THE
NORTHEASTERN PORTION OF THE NATION FROM MONDAY INTO THE MID WEEK
PERIOD.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 1150 PM EST MONDAY...
IFR TO LIFR CONDITIONS EXPECTED TO CONTINUE AT ALL AIRPORTS
THROUGH AT LEAST TONIGHT...AND FOR WESTERN AIRPORTS EVEN INTO
EARLY PART OF TUESDAY...UNDER THE INFLUENCE OF COLD AIR DAMMING
WHICH IS ONLY STRENGTHENING WITH TIME. ALL AIRPORTS EXCEPT FOR KDAN
SHOULD SEE SOME VERY LIGHT RAIN CHANGE TO LIGHT SNOW
OVERNIGHT...BUT NOT EXPECTED TO STICK MUCH AT ALL EXCEPT FOR THE
HIGHER ELEVATION AIRPORTS SUCH AS KLWB...AND KBCB. NOT SURE IT
WILL BE COLD ENOUGH TO REALLY ACCUMULATE AT KBLF AND KROA OR KLYH.
KDAN LIKELY WILL NOT EVEN SEE CHANGEOVER. IN ANY CASE...SNOW
AMOUNTS WOULD ONLY APPROACH AN INCH IN THE WORSE-CASE SCENARIO.
LOW CONFIDENCE FOR WHEN CONDITIONS MAY BEGIN TO BREAK OUT AND
LIFT ON TUESDAY. MORE CONFIDENT THAT KROA...KLYH AND KDAN WILL
IMPROVE TO VFR BY TUESDAY AFTERNOON AS DRIER AIR CONTINUES TO
FILTER DOWN FROM NORTH. CLEARING WILL CONTINUE IN THE AFTERNOON
AND EVENING. EVEN MOUNTAIN TAF SITES WILL IMPROVE TO VFR.
EXTENDED DISCUSSION...
A LARGE AREA OF HIGH PRESSURE WILL START TO NOSE INTO THE AREA
FROM THE WEST LATER TUESDAY INTO WEDNESDAY. VFR WILL THEN
PREVAIL THROUGH AT LEAST THURSDAY
CONDITIONS DETERIORATE THE WEEKEND. THE NEXT LOW PRESSURE SYSTEM
TO AFFECT THE AREA WILL COME FROM THE SOUTHWEST..DEVELOPING ALONG
THE TEXAS GULF COAST FRIDAY...THEN MOVING NORTHEAST ACROSS THE MID
ATLANTIC REGION FOR THE WEEKEND. THIS SYSTEM LOOKS LIKE IT WILL
PRODUCE A MULTI-DAY PERIOD OF SUB-VFR CONDITIONS...BEGINNING AS
EARLY AS FRIDAY NIGHT...AND LINGERING THROUGH SUNDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...SK
NEAR TERM...SK/WERT
SHORT TERM...PH
LONG TERM...WERT
AVIATION...AMS/WERT
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
1020 AM EST TUE DEC 30 2014
.DISCUSSION...
FRONTAL BNDRY JUST N OF THE I-4 CORRIDOR HAS STALLED DUE TO A
STUBBORN H100-H70 HI PRES RIDGE OVER THE FL STRAITS. MRNG RAOBS SHOW
DEEP MOISTURE AHEAD OF THE FRONT WITH PWAT VALUES BTWN 1.5"-1.8" AS
KXMR-KTBW RESPECTABLY...BUT DECREASING EITHER SIDE OF THE BNDRY TO
1.2" AT KJAX/KMFL. RUC ANALYSIS SHOWS RESPECTABLE MID/UPR LVL
DYNAMIC SUPPORT ALONG THE FRNTL BNDRY OVER THE GOMEX...BUT LITTLE
OVER CENTRAL FL. LATEST RADAR TREND REFLECTS THIS LACK OF SUPPORT AS
AN AREA OF MODERATE RAIN THAT MOVED ONSHORE OVER TAMPA BAY HAS
WEAKENED INTO A BROAD AREA OF LIGHT STRATIFORM RAIN AS IT APPROACHED
THE FL TURNPIKE.
WHILE THE FRONT HAS STALLED...RUC SHOWS AN H100-H70 N/NW SURGE OVER
THE LWR MS VALLEY THAT SHOULD GIVE IT THE PUSH IT NEEDS TO PLOW THE
RIDGE AXIS OUT OF THE FL STRAITS LATER TODAY. LITTLE IN THE WAY OF
SFC HEATING N OF SR60 AS CLOUD COVER ENTRENCHED WITHIN THE FRONTAL
TROF STREAMS ACRS CENTRAL FL. PRECIP WILL BE SPOTTY AT BEST WITH QPF
VALUES AOB 0.10". FURTHER S...WHILE SUNNY SKIES AND SFC DEWPOINTS IN
THE M/U60S NORMALLY WOULD SUGGEST THE THREAT OF TSRAS...THE LACK OF
ANY SIG DYNAMIC SUPPORT COUPLED WITH A LINGERING SUBSIDENCE
INVERSION IN THE H85-H70 LYR (LAPSE RATES BTWN 3.0-4.0C/KM) SUGGESTS
THE SRN CWA WILL REMAIN DRY.
WILL KNOCK A FEW DEG OF MAX TEMPS FROM BREVARD/OSCEOLA NWD...ALSO
WILL SHAVE POPS BACK A TOUCH ARND LAKE OKEECHOBEE.
&&
.AVIATION...THRU 31/12Z
SFC WNDS: THRU 30/20Z...W/SW 5-8KTS BCMG N. AFT 30/20Z...N 4-7KTS.
VSBYS/WX: THRU 30/20Z...N OF KTIX-KISM...PDS OF MVFR IN -RA/BR...S
OF KTIX-KISM PREVAILING VFR WITH LCL IFR IN BR/FG ENDING BY 30/16Z.
BTWN 30/20Z-31/04Z...N OF KTIX-KISM VFR...S OF KTIX-KISM PDS OF MVFR
IN -RA/BR. AFT 31/04Z...AREAS MVFR BR WITH LCL LIFR FG N OF
KDAB-KISM.
CIGS: THRU 30/17Z...N OF KTIX-KISM PREVAILING BTWN FL015-020 WITH
AREAS LIFR BLO FL005...S OF KTIX-KISM PREVAILING AOA FL120 WITH LCL
LIFR BLO FL004. BTWN 30/17Z-31/04Z...PREVAILING FL040-060 WITH AREAS
MVFR FL020-030. AFT 31/04Z...PREVAILING MVFR FL020-030...N OF
KTIX-KISM AREAS LIFR BLO FL005...S OF KTIX-KISM LCL IFR BTWN
FL005-009.
&&
.MARINE...
RUC ANALYSIS SHOWS TEH FRONTAL TROF EXTENDING FROM THE CENTRAL GOMEX
TO THE NC OUTER BANKS. LATEST SFC OBS INDICATE THE FRONT HAS PUSHED
S OF ST. AUGUSTINE BUT REMAINS N OF BUOY009...FOG/CALM WINDS ALONG
THE COAST BTWN PALM COAST AND NEW SMYRNA BEACH AS OF 14Z SUGGEST THE
BNDRY IS IN THE VCNTY OF THE VOLUSIA/FLAGLER COUNTY LINE.
DESPITE A STUBBORN RIDGE AXIS OVER THE FL STRAITS...THE FRONT WILL
PUSH THRU CENTRAL FL THRU SUNSET...FORCING SFC/BNDRY LYR WINDS TO
VEER FROM W/SW TO DUE NORTH...GENERALLY BTWN 10-15KTS. SEAS AOB 2FT
NEARSHORE AND 2-3FT OFFSHORE...INCREASING TO 2-3FT NEARSHORE AND
3-4FT OFFSHORE AS WINDS SWING ARND TO THE N. NO SIG CHANGES.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...BRAGAW
LONG TERM/IMPACT WX...LASCODY
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
1010 AM EST TUE DEC 30 2014
.UPDATE (REST OF TODAY THROUGH WEDNESDAY)...
15Z WATER VAPOR AND H4 RAP ANALYSIS CONTINUE TO SHOW MUCH OF THE
NATION UNDER A BROAD LONGWAVE TROUGH. THE MOST ENERGETIC FEATURE
WITHIN THIS TROUGH IS A STRONG SHORTWAVE DROPPING SOUTH THROUGH THE
INTERMOUNTAIN WEST WHICH IS PROGGED BY ALL THE NUMERICAL GUIDANCE TO
BECOME A LARGE CUTOFF LOW OVER THE SOUTHWESTERN STATES BEFORE
EJECTING EASTWARD ACROSS THE SOUTHERN/CENTRAL PLAINS LATER IN THE
WEEK. OUR FORECAST AREA RESIDES WITHIN A ZONE OF DEEP LAYER
SOUTHWEST FLOW BETWEEN THE LONGWAVE TROUGH AND AND WEST-EAST
ORIENTED RIDGE ACROSS THE NORTHWEST CARIBBEAN. A PLUME OF SOUTHERN
STREAM MOISTURE IS STILL IN WV IMAGERY RIDGING THIS FLOW OVER THE
EASTERN GULF OF MEXICO AND FL PENINSULA.
AT THE SURFACE...A WEAK COLD FRONT HAS ENTERED THE NORTHERN FLORIDA
PENINSULA AND IS NOW STRETCHED ACROSS THE NATURE COAST ON A SLOW
TREK SOUTHWARD THROUGH THE DAY.
REGIONAL RADARS CONTINUE TO SHOW AN EXPANSION OF THE SHOWERS ALONG
AND AHEAD OF THIS BOUNDARY...AND THIS IS LIKELY RELATED TO SOME
ADDED SYNOPTIC SUPPORT FOR LIFT ASSOCIATED WITH A WEAK/SUBTLE
PASSING SHORTWAVE ALOFT OVER THE NE GULF OF MEXICO. HAVE
SUBSTANTIALLY INCREASED RAIN CHANCES FOR THE MORNING THROUGH
WEST-CENTRAL FLORIDA AS A SOGGY NEXT FEW HOURS NOW APPEARS LIKELY.
FORECAST GRIDS AND TEXT PRODUCTS HAVE BEEN UPDATED.
THE RAIN IS ALSO HELPING LIFT SOME OF THE DENSE FOG SEEN AROUND THE
AREA. FOR LOCATIONS SOUTH OF THE RAIN SHIELD...THE DENSE FOG IS
HOLDING IN LONGER. JUST BEGINNING TO SEE THE EROSION OF THIS FOG DUE
TO DIURNAL MIXING AND VISIBILITIES SHOULD BE IMPROVING QUICKLY INTO
THE LATER MORNING HOURS. WITH ALL THIS IN MIND WILL ALLOW THE DENSE
FOG ADVISORY TO EXPIRE AT 10AM...EVEN THOUGH A FEW SPOTS MAY STILL
TECHNICALLY MEET CRITERIA FOR A BIT LONGER. USING THE LATEST HRRR
FOR TIMING...THE FRONT STILL LOOKS TO ARRIVE AT THE I-4 CORRIDOR
AROUND MIDDAY/EARLY AFTERNOON AND THEN SLOWLY SETTLE SOUTH TO NEAR
PUNTA GORDA AROUND SUNSET. THE ORGANIZATION AND COVERAGE OF SHOWERS
SHOULD BEGIN TO DIMINISH DURING THE SECOND HALF OF THE DAY AS THE
SHORTWAVE INFLUENCE PASSES TO OUR EAST. HOWEVER...THE LOW LEVEL
BOUNDARY FOCUS WILL STILL KEEP THE CHANCE FOR MORE SCT SHOWERS IN
THE FORECAST. ALSO WITH THE FLOW BECOMING MORE AND MORE PARALLEL TO
THE FRONT...THE ACTUALLY BOUNDARY PASSAGE WILL NOT NECESSARILY END
THE CHANCE FOR RAIN AS MANY OF THE GUIDANCE MEMBERS ARE INDICATING
THE BOUNDARY WILL TAKE ON AN INCREASINGLY ANAFRONT CONFIGURATION BY
LATER TODAY WHERE BETTER CHANCES FOR THE CLOUDS AND SHOWERS ARE
ACTUALLY ALONG AND BEHIND THE BOUNDARY.
FOR OUR SOUTHERN ZONES...FOG WILL BE LIFTING BY MIDDAY. YOUR SHOWERS
CHANCES WILL BE INCREASING LATER THIS AFTERNOON AND INTO THE EVENING
AS THE BOUNDARY MAKES IT WAYS SOUTHWARD.
TONIGHT AND WEDNESDAY...THE FRONT STALLS AND BEGINS TO WASH OUT OVER
THE SOUTHERN PENINSULA. THE GUIDANCE MEMBERS ARE ALL STARTING TO
INDICATE THE DEVELOPMENT OF AN INVERTED TROUGH OVER THE GULF STREAM
OFF THE FL EAST COAST DURING THIS TIME. THIS FOCUS ALONG WITH SOME
SPEED CONVERGENCE ALONG THE COAST LOOKS TO BE ENOUGH FOR SHOWERS TO
BEGIN MIGRATING ONSHORE. GOING TO HAVE TO LOOK AT THIS A BIT CLOSER
WITH THE 12Z GUIDANCE AS SOME OF THESE SHOWERS MAY HAVE A CHANCE TO
MIGRATE INLAND ENOUGH TO IMPACT PORTIONS OF POLK/HIGHLANDS COUNTIES
ON WEDNESDAY. WOULD NOT BE A LOT OF RAIN...BUT WOULD NOT BE THE
COMPLETELY DRY FORECAST CURRENTLY IN THE GRIDS. ELSEWHERE WEDNESDAY
STILL LOOKS TO BE MAINLY DRY...HOWEVER PROB NOT A WHOLE LOT OF SUN
AROUND...ESPECIALLY FOR THE I-4 CORRIDOR AND SOUTHWARD.
&&
.AVIATION...
VARYING CONDITIONS OUT THERE THIS MORNING WITH A MIX OF FOG AND
RAIN. ALTHOUGH MANY STATIONS WILL NOT BE PREVAILING LIFR OR
LOWER...PERIODS OF THESE LOW RESTRICTIONS WILL REMAIN POSSIBLE FOR
ALL TERMINALS THROUGH THE MORNING HOURS. IMPROVEMENT WILL OCCUR FOR
THE SECOND HALF OF THE DAY...HOWEVER AT LEAST PERIODS OF MVFR
CONDITIONS SHOULD STILL BE EXPECTED.
&&
.MARINE...
AREAS OF SEA FOG REMAIN OVER THE WATERS THIS MORNING AHEAD OF AN
APPROACHING COLD FRONT. THE FOG HAS BECOME LESS PREVALENT OVER THE
PAST COUPLE OF HOURS...ESPECIALLY OVER TAMPA BAY AND THE GULF WATERS
TO THE WEST OF THE BAY AS SHOWERS HAVE BEEN ONGOING THERE FOR
SEVERAL HOURS. THE SEA FOG IS EXPECTED TO DISSIPATE BY LATE MORNING
OR EARLY AFTERNOON AS THE FRONT SINKS SOUTHWARD. THERE WILL BE A
CHANCE FOR SHOWERS THROUGH THE REST OF THE DAY AS WELL...WHICH COULD
BRIEFLY REDUCE VISIBILITY OVER THE WATERS.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 78 63 75 59 / 90 10 20 10
FMY 82 65 81 63 / 30 20 20 10
GIF 79 62 75 57 / 80 10 20 10
SRQ 79 63 76 60 / 70 10 20 10
BKV 78 59 74 53 / 60 10 10 10
SPG 77 65 74 60 / 90 10 20 10
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
UPDATE/AVIATION...MROCZKA
MARINE...CARLISLE
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
825 AM EST TUE DEC 30 2014
.UPDATE (REST OF TODAY THROUGH WEDNESDAY)...
13Z WATER VAPOR AND H4 RAP ANALYSIS CONTINUE TO SHOW MUCH OF THE
NATION UNDER A BROAD LONGWAVE TROUGH. THE MOST ENERGETIC FEATURE
WITHIN THIS TROUGH IS A STRONG SHORTWAVE DROPPING SOUTH THROUGH THE
INTERMOUNTAIN WEST WHICH IS PROGGED BY ALL THE NUMERICAL GUIDANCE TO
BECOME A LARGE CUTOFF LOW OVER THE SOUTHWESTERN STATES BEFORE
EJECTING EASTWARD ACROSS THE SOUTHERN/CENTRAL PLAINS LATER IN THE
WEEK. OUR FORECAST AREA RESIDES WITHIN A ZONE OF DEEP LAYER
SOUTHWEST FLOW BETWEEN THE LONGWAVE TROUGH AND AND WEST-EAST
ORIENTED RIDGE ACROSS THE NORTHWEST CARIBBEAN. A PLUME OF SOUTHERN
STREAM MOISTURE IS STILL IN WV IMAGERY RIDGING THIS FLOW OVER THE
EASTERN GULF OF MEXICO AND FL PENINSULA.
AT THE SURFACE...A WEAK COLD FRONT HAS ENTERED THE NORTHERN FLORIDA
PENINSULA AND IS NOW STRETCHED ACROSS THE NATURE COAST ON A SLOW
TREK SOUTHWARD THROUGH THE DAY.
REGIONAL RADARS HAVE SHOWN A RAPID EXPANSION OF THE SHOWERS ALONG
AND AHEAD OF THIS BOUNDARY DURING THE PAST FEW HOURS...AND THIS IS
LIKELY RELATED TO SOME ADDED SYNOPTIC SUPPORT FOR LIFT ASSOCIATED
WITH A WEAK/SUBTLE PASSING SHORTWAVE ALOFT OVER THE NE GULF OF
MEXICO. HAVE SUBSTANTIALLY INCREASED RAIN CHANCES FOR THE MORNING
THROUGH WEST-CENTRAL FLORIDA AS A SOGGY NEXT FEW HOURS NOW APPEARS
LIKELY. FORECAST GRIDS AND TEXT PRODUCTS HAVE BEEN UPDATED.
THE RAIN IS ALSO HELPING LIFT SOME OF THE DENSE FOG SEEN AROUND THE
AREA AND WILL BE MAKING DECISIONS ON WHAT TO DO WITH THE DENSE FOG
ADVISORY IN THE NEXT COUPLE OF HOURS. USING THE LATEST HRRR FOR
TIMING...THE FRONT LOOKS TO ARRIVE THE I-4 CORRIDOR AROUND MIDDAY
AND THEN SLOWLY SETTLE SOUTH TO NEAR PUNTA GORDA AROUND SUNSET. THE
ORGANIZATION AND COVERAGE OF SHOWERS SHOULD BEGIN TO DIMINISH DURING
THE SECOND HALF OF THE DAY AS THE SHORTWAVE INFLUENCE PASSES TO OUR
EAST. HOWEVER...THE LOW LEVEL BOUNDARY FOCUS WILL STILL KEEP THE
CHANCE FOR MORE SCT SHOWERS IN THE FORECAST. ALSO WITH THE FLOW
BECOMING MORE AND MORE PARALLEL TO THE FRONT...THE ACTUALLY
BOUNDARY PASSAGE WILL NOT NECESSARILY END THE CHANCE FOR RAIN AS
MANY OF THE GUIDANCE MEMBERS ARE INDICATING THE BOUNDARY WILL TAKE
ON AN INCREASINGLY ANAFRONT CONFIGURATION BY LATER TODAY WHERE
BETTER CHANCES FOR THE CLOUDS AND SHOWERS ARE ACTUALLY ALONG AND
BEHIND THE BOUNDARY.
FOR OUR SOUTHERN ZONES...A COUPLE MORE HOURS WITH THE FOG AND THEN
WE SHOULD BEGIN TO BURN IT OFF. YOUR SHOWERS CHANCES WILL BE
INCREASING THIS AFTERNOON AND INTO THE EVENING AS THE BOUNDARY MAKES
IT WAYS SOUTHWARD.
TONIGHT AND WEDNESDAY...THE FRONT STALLS AND BEGINS TO WASH OUT OVER
THE SOUTHERN PENINSULA. THE GUIDANCE MEMBERS ARE ALL STARTING TO
INDICATE THE DEVELOPMENT OF AN INVERTED TROUGH OVER THE GULF STREAM
OFF THE FL EAST COAST DURING THIS TIME. THIS FOCUS ALONG WITH SOME
SPEED CONVERGENCE ALONG THE COAST LOOKS TO BE ENOUGH FOR SHOWERS TO
BEGIN MIGRATING ONSHORE. GOING TO HAVE TO LOOK AT THIS A BIT CLOSER
WITH THE 12Z GUIDANCE AS SOME OF THESE SHOWERS MAY HAVE A CHANCE TO
MIGRATE INLAND ENOUGH TO IMPACT PORTIONS OF POLK/HIGHLANDS COUNTIES
ON WEDNESDAY. WOULD NOT BE A LOT OF RAIN...BUT WOULD NOT BE THE
COMPLETELY DRY FORECAST CURRENTLY IN THE GRIDS. ELSEWHERE WEDNESDAY
STILL LOOKS TO BE MAINLY DRY...HOWEVER PROB NOT A WHOLE LOT OF SUN
AROUND...ESPECIALLY FOR THE I-4 CORRIDOR AND SOUTHWARD.
&&
.AVIATION...
VARYING CONDITIONS OUT THERE THIS MORNING WITH A MIX OF FOG AND
RAIN. ALTHOUGH MANY STATIONS WILL NOT BE PREVAILING LIFR OR
LOWER...PERIODS OF THESE LOW RESTRICTIONS WILL REMAIN POSSIBLE FOR
ALL TERMINALS THROUGH THE MORNING HOURS. IMPROVEMENT WILL OCCUR FOR
THE SECOND HALF OF THE DAY...HOWEVER AT LEAST PERIODS OF MVFR
CONDITIONS SHOULD STILL BE EXPECTED.
&&
.MARINE...
DENSE SEA FOG WILL BE LOCATED OVER THE NEAR SHORE COASTAL WATERS
SOUTH OF THE COLD FRONT. AS THE COLD FRONT GRADUALLY SINKS SOUTH
TODAY...THE AREA OF SEA FOG WILL BE SINK SOUTH AND DECREASE IN AREAL
COVERAGE...DISSIPATING BY LATE TODAY. WEAK HIGH PRESSURE WILL BUILD
OVER THE WATERS BEHIND THE FRONT THROUGH THE REMAINDER OF THE WEEK.
WINDS WILL BE LESS THAN 15 KNOTS WITH SEAS LESS THAN 4 FEET THROUGH
THE PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 78 63 75 59 / 90 10 20 10
FMY 82 65 81 63 / 30 20 20 10
GIF 79 62 75 57 / 80 10 20 10
SRQ 79 63 76 60 / 70 10 20 10
BKV 78 59 74 53 / 60 10 10 10
SPG 77 65 74 60 / 90 10 20 10
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR
COASTAL CHARLOTTE-COASTAL CITRUS-COASTAL HERNANDO-
COASTAL HILLSBOROUGH-COASTAL LEE-COASTAL LEVY-COASTAL
MANATEE-COASTAL PASCO-COASTAL SARASOTA-DESOTO-HARDEE-
HIGHLANDS-INLAND CHARLOTTE-INLAND HERNANDO-INLAND
HILLSBOROUGH-INLAND LEE-INLAND MANATEE-INLAND PASCO-
INLAND SARASOTA-PINELLAS-POLK.
GULF WATERS...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING
FOR BONITA BEACH TO ENGLEWOOD OUT 20 NM-CHARLOTTE HARBOR AND
PINE ISLAND SOUND-ENGLEWOOD TO TARPON SPRINGS OUT 20
NM-TAMPA BAY WATERS-TARPON SPRINGS TO SUWANNEE RIVER
OUT 20 NM.
&&
$$
UPDATE/AVIATION...MROCZKA
MARINE...CARLISLE
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
614 AM EST TUE DEC 30 2014
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE AREA TODAY INTO FRIDAY...BEFORE
MOVING INTO THE ATLANTIC BY SATURDAY. A COASTAL TROUGH WILL DEVELOP
SATURDAY AND LIFT NORTH OF THE REGION BY SUNDAY. A COLD FRONT WILL
THEN PASS OFF THE COAST EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MESOSCALE UPDATE...THE DENSE FOG IN THE SAVANNAH AND BEAUFORT
AREAS HAS LIFTED BACK INTO A VERY LOW STRATUS DECK. WEBCAMS AND
SURFACE OBSERVATIONS INDICATE VSBYS HAVE IMPROVED TO 1-2 MILES.
HOWEVER...LOCALLY DENSE FOG IS STILL LIKELY NEAR BODIES OF WATER
AND OTHER LOW LYING AREAS. AN AREA OF DENSE FOG IS TRYING TO NOSE
INTO PARTS OF JENKINS-CANDLER-EVANS-TATTNALL AND BULLOCH. WITH
SUNRISE APPROACHING...PREFER TO HANDLE THIS WITH A SPECIAL WEATHER
STATEMENT. HOWEVER...A DENSE FOG ADV CAN NOT BE RULED OUT. SURFACE
TROUGH/SECONDARY COLD SURGE IS WORKING ITS WAY SOUTH OF THE SOUTH
SANTEE RIVER AND WILL CROSS THE I-26 CORRIDOR THROUGH SUNRISE.
HIGHS WILL LIKELY OCCUR DAY TIME HIGHS WILL LIKELY OCCUR IN THE
7-9AM TIME FRAME BEFORE TEMPERATURES HOLD STEADY THEN POSSIBLY
FALL. ADJUSTED HOURLY TEMPERATURES ACROSS THE CHARLESTON TRI-
COUNTY AREA A BIT.
TODAY...LOW CONFIDENCE FORECAST TODAY. THE COLD FRONT AND
ASSOCIATED FRONTAL WAVE ARE NOW WELL OFFSHORE WITH A NORTHERLY
LOW-LEVEL FLOW DOMINATING IN ITS WAKE. A WEAK POST FRONTAL SURFACE
TROUGH DELINEATING A SURGE OF COOLER AIR WILL APPROACH THE
CHARLESTON AREA BY SUNRISE...THE SAVANNAH AREA BY MID/LATE MORNING
AND FINALLY CLEARING THE ALTAMAHA RIVER BY LATE AFTERNOON. MODELS
SHOW A TRANSIENT HYBRID WEDGE SETTING UP ACROSS MAINLY THE CENTRAL
AND NORTHERN PORTIONS OF THE FORECAST AREA IN THE WAKE OF THE
TROUGH AS 290K ISENTROPIC ASSENT BRIEFLY INTENSIFIES ATOP THE LOW-
LEVEL POST FRONTAL WEDGING PATTERN. THIS PATTERN WILL ESSENTIALLY
REINFORCE THE WIDESPREAD LOW CLOUDS AND PATCHY DRIZZLE THAT ARE
ALREADY IN PLACE ACROSS THE LOWCOUNTRY AND COASTAL EMPIRE FOR A
GOOD PORTION OF THE DAY. THE TEMPERATURE FORECAST IS PROVING TO BE
EXTREMELY CHALLENGING AS A RESULT AND ASSUMES THE TRANSIENT WEDGE
ACTUALLY DEVELOPS AS DEPICTED IN THE HIGHER RESOLUTION DATA SETS.
DAILY HIGHS /7AM-6PM/ WILL LIKELY OCCUR BY MID-MORNING ACROSS THE
CHARLESTON TRI-COUNTY AREA AND EARLY AFTERNOON ACROSS THE
REMAINDER OF SOUTHEAST SOUTH CAROLINA AND SOUTHEAST GEORGIA.
TEMPERATURES WILL LIKELY HOLD STEADY OR SLOWLY FALL NORTH THE
SAVANNAH RIVER AS THE WEDGE BRIEFING INTENSIFIES. HIGHS WILL RANGE
MID 50S NORTH...UPPER 50/NEAR 60 CENTRAL TO THE LOWER-MID 60S
SOUTH. UTILIZE A 30/30/30 BLEND OF RAP/H3R AND GLAMP DATA TO
CONSTRUCT HOURLY TEMPERATURES. SINCE THIS IS A VERY LOW CONFIDENCE
FORECAST...CHANGES--SOME POSSIBLY SIGNIFICANT--WILL LIKELY BE
NEEDED THROUGHOUT THE DAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
TONIGHT...THE TRANSIENT HYBRID WEDGE WILL QUICKLY BREAKDOWN THIS
EVENING AS HIGH PRESSURE FINALLY BRIDGES THE SOUTHERN APPALACHIANS
AND BECOMES MORE DOMINATE ACROSS THE SOUTHEAST STATES. A GOOD BIT
OF CLOUD COVER WILL LINGER THROUGH THE NIGHT WITH THE POTENTIAL
FOR SOME CLEARING TO OCCUR ACROSS THE NORTH AFTER 3 AM. WILL HAVE
TO WATCH FOR SOME FOG TO DEVELOP AFTER MIDNIGHT...BUT THIS DOES
NOT LOOK SIGNIFICANT AT THIS TIME. LOWS WILL RANGE FROM THE MID-
UPPER 30S INTERIOR NORTH WHERE THE BETTER CHANCES FOR CLEARING
WILL OCCUR WITH UPPER 30S TO LOWER 40S ELSEWHERE...EXCEPT MID 40S
ALONG THE GEORGIA COAST WHERE ONSHORE WINDS WILL MODERATE
TEMPERATURES A BIT.
WEDNESDAY AND THURSDAY...EXPANSIVE SURFACE HIGH PRESSURE WILL
BE GRADUALLY WEAKENING AS IT SLIPS TOWARD THE EAST COAST UNDER
RELATIVELY ZONAL FLOW ALOFT. EXPECT DRY CONDITIONS TO PREVAIL
WEDNESDAY AND THURSDAY WITHIN THIS PATTERN. TEMPERATURES
WEDNESDAY WILL BE A FEW DEGREES COOLER THAN NORMAL...PEAKING IN THE
MID TO UPPER 50S DURING THE AFTERNOON AND FALLING INTO THE LOW 30S
NORTH TO UPPER 30S COAST AND SOUTH OVERNIGHT. NORTH FLOW WEAKENS
ON THURSDAY AS THE CENTER OF THE SURFACE HIGH PASSES DIRECTLY OVER
THE REGION...AND WITH SUBTLE RIDGING BUILDING UP FROM THE
BAHAMAS...HIGH TEMPERATURES WILL MODERATE TOWARD SEASONAL NORMALS
IN THE UPPER 50S TO LOWER 60S. A GRADUALLY IMPROVING TAP INTO GULF
MOISTURE LATE THURSDAY WILL SUPPORT INCREASING CLOUDS...WITH LOW
TEMPERATURES A FEW DEGREES MILDER IN THE UPPER 30S INLAND TO LOW
40S CLOSER TO THE COAST.
FRIDAY...AN UPPER LEVEL CUT OFF LOW WILL MOVE FROM THE SOUTHWEST
STATES INTO THE SOUTHERN PLAINS...PROVIDING THE ENERGY TO DEVELOP
A WAVE OF LOW PRESSURE ACROSS THE WESTERN GULF LATE IN THE DAY.
THE SOUTHEAST STATES WILL REMAIN ON THE PERIPHERY OF ATLANTIC HIGH
PRESSURE...WHERE SHORTWAVE ENERGY TRACKING UP FROM THE GULF OF
MEXICO WILL SUPPORT THE GRADUAL AMPLIFICATION OF A COASTAL TROUGH.
NUMERICAL MODEL SOLUTIONS ARE INDICATING SUFFICIENT ISENTROPIC
ASCENT BETWEEN THE COASTAL TROUGH AND A DEVELOPING INLAND WEDGE
TO GENERATE ISOLATED TO SCATTERED RAIN...WITH BEST COVERAGE
ACROSS NORTHERN AND INLAND AREAS. TEMPERATURES COULD BE A DEGREE
OR TWO COOLER THAN THE PREVIOUS DAY GIVEN THE INCREASING CLOUD
COVER...YET STILL RANGE NEAR SEASONAL NORMALS IN THE UPPER 50S TO
LOW 60S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
FRIDAY NIGHT THROUGH SUNDAY...A TRANSIENT INLAND WEDGE/COASTAL
TROUGH PATTERN WILL BE IN PLACE THROUGH EARLY SATURDAY...BEFORE
THE COASTAL TROUGH QUICKLY LIFTS NORTH OF THE REGION AHEAD OF AN
APPROACHING COLD FRONT FROM THE WEST. THE CUT OFF LOW ACROSS THE
SOUTHERN PLAINS WILL DAMPEN AND LIFT NORTHEAST INTO THE OHIO
VALLEY ON SATURDAY. THE ASSOCIATED SURFACE LOW WILL PULL INTO THE
NEW ENGLAND STATES SUNDAY...WITH ITS TRAILING COLD FRONT
PROGRESSING THROUGH THE MID ATLANTIC AND SOUTHEAST STATES BY
SUNDAY AFTERNOON. HIGH TEMPERATURES WILL SURGE INTO THE 60S TO
AROUND 70 DEGREES SATURDAY AND SUNDAY WITHIN WARM SOUTHERLY FLOW
AHEAD OF THE FRONT...WHILE SCATTERED SHOWERS ARE POSSIBLE SATURDAY
THROUGH SUNDAY AFTERNOON. PREFER TO REMAIN RATHER CONSERVATIVE
WITH RAIN CHANCES AT THIS POINT...CONSIDERING THE SOUTHERN END OF
THE FRONT WILL RUN INTO THE PERIPHERY OF THE SUBTROPICAL RIDGE AND
BECOME PARALLEL TO FLOW ALOFT.
SUNDAY NIGHT THROUGH TUESDAY...SURFACE HIGH PRESSURE WILL BUILD IN
THE WAKE OF THE DEPARTING COLD FRONT EARLY NEXT WEEK...EVENTUALLY
SETTLING TO THE NORTH OF THE AREA. RAIN FREE CONDITIONS WILL
PREVAIL. TEMPERATURES ARE EXPECTED TO RETURN TO SEASONAL
NORMALS...POSSIBLY COOLER IF A WEDGE PATTERN CAN SET UP TOWARD THE
END OF THE FORECAST PERIOD.
&&
.AVIATION /11Z TUESDAY THROUGH SATURDAY/...
CIGS WILL REMAIN BELOW ALTERNATE MINIMUMS THROUGH 14-15Z WITH CIGS
RISING THEREAFTER. EXPECT MVFR CIGS TO RETURN TO KSAV BY 16Z WHICH
WILL REMAIN IN PLACE THROUGH THE REMAINDER OF THE 12Z TAF PERIOD.
AT KCHS...CIGS WILL BE SLOWER TO RISE WITH IFR CIGS RETURNING BY
17-18Z. THESE CONDITIONS WILL LINGER THROUGH 12Z WEDNESDAY.
EXTENDED AVIATION OUTLOOK...VFR CONDITIONS WILL PREVAIL WEDNESDAY
AND THURSDAY. CHANCES FOR FLIGHT RESTRICTIONS INCREASE INTO THE
WEEKEND AS THE NEXT SYSTEM IMPACTS THE REGION.
&&
.MARINE...
TODAY...CEILINGS OF 100 FT AT THE HILTON HEAD AIRPORT AND WEBCAMS
IN THE SAVANNAH RIVER AS WELL AS TYBEE ISLAND SUGGEST SEA FOG IS
IN PLACE ACROSS THE COASTAL WATERS THIS MORNING. IT IS UNCLEAR
EXACTLY HOW WIDESPREAD THE FOG IS...BUT RAP VISIBILITIES DATA
SUGGEST ITS PROBABLY PRETTY WIDESPREAD. WFO JAX RECENTLY RELAYED
THAT THE BAR PILOTS OUT OF SAINT SIMMONS ARE REPORTING IMPROVED
VSBYS OVER THE PAST HOUR...BUT THE SHELF WATERS OFF TYBEE ISLAND
ARE SEVERAL DEGREES COOLER. PREFER TO HOLD THE MARINE DENSE FOG
ADVISORY FOR THE GEORGIA NEARSHORE AND BEAUFORT COUNTY WATERS
UNTIL 8 AM...OR AT LEAST UNTIL CONDITIONS CAN BE BETTER EVALUATED
ON COASTAL WEBCAMS AS THE SUN RISES. OTHERWISE...NORTH WINDS WILL
INCREASE TO 10-15 KT TODAY WITH SEAS 1-3 FT.
TONIGHT...WINDS WILL INCREASE A BIT AS THE PRESSURE GRADIENT
INDUCED BY HIGH PRESSURE BUILDING IN FROM THE WEST TIGHTENS.
EXPECT WINDS OF 15-20 KT WITH SEAS 2-3 FT NEARSHORE...4-5 FT
OFFSHORE.
WEDNESDAY THROUGH SATURDAY...THE PRESSURE GRADIENT WILL REMAIN
RELATIVELY TIGHT INTO WEDNESDAY MORNING ON THE PERIPHERY OF HIGH
PRESSURE BUILDING FROM THE WEST. MARGINAL SMALL CRAFT ADVISORY
WINDS IN GUSTS TO 25 KT COULD LINGER ACROSS THE OFFSHORE GEORGIA
WATERS...BEFORE CONDITIONS SLOWLY IMPROVE AS THE DAY PROGRESSES.
THE SURFACE HIGH WILL THEN STEADILY TRACK EAST AND ALLOW THE
GRADIENT TO RELAX TOWARD THE END OF THE WEEK. A COASTAL TROUGH
WILL DEVELOP LATE FRIDAY INTO SATURDAY...WITH INCREASING SOUTHERLY
FLOW IN IT WAKE.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR AMZ352-354.
&&
$$
ST
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
951 AM EST TUE DEC 30 2014
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 304 AM EST TUE DEC 30 2014
IN THE NEAR TERM PERIOD...THE FOCUS WILL BE ON THE COOL DOWN AS
ARCTIC HIGH PRESSURE STRENGTHENS OVER WESTERN CANADA. MUCH COLDER
AIR WILL SPILL INTO PORTIONS OF THE CONTINENTAL U.S. AS A RESULT.
HOWEVER...NO PRECIPITATION IS EXPECTED UNTIL THE EXTENDED PERIOD
WHEN A CUT OFF LOW OVER THE DESERT SOUTHWEST MAKES ITS PROGRESSION
ACROSS THE PLAINS...AND INTO CENTRAL INDIANA. TIMING AND TRACKING
INCONSISTENCIES ARE MAKING IT DIFFICULT TO PINPOINT PRECIP TYPE AT
THIS TIME...BUT EARLY INDICATIONS ARE SHOWING MIXED PRECIPITATION
FOR MOST OF FRIDAY AND SATURDAY. PRECIP WILL END FROM WEST TO EAST
ON SUNDAY...AND THE REMAINDER OF THE EXTENDED FORECAST WILL BE DRY
AS FLOW ALOFT BECOMES MORE ZONAL ON MONDAY.
&&
.NEAR TERM /THIS AFTERNOON/...
ISSUED AT 950 AM EST TUE DEC 30 2014
FLURRIES WILL BE REMOVED FROM THE NORTHWEST. EVEN IN CLEAR AIR
MODE THE RADARS UPSTREAM DONT SHOW ANYTHING AND THE HRRR DOESNT
INTRODUCE ANYTHING.
OTHER ELEMENTS OF THE EARLIER FORECAST ARE WORKING WELL BASED ON THE
LATEST OBSERVATIONS.&&
.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
ISSUED AT 304 AM EST TUE DEC 30 2014
THE MAIN FOCUS OF THE SHORT TERM PERIOD CONTINUES TO BE ON
TEMPERATURES AND ANY CHANGES IN TIMING OF DAY 5 STORM SYSTEM
THAT COULD POSSIBLY RESULT IN PRECIP AS EARLY AS THURSDAY NIGHT.
TEMPERATURES WILL REALLY PLUMMET TONIGHT WITH COLD AIR IN PLACE
AND PARTLY CLOUDY SKIES. SOME OF THE COLDEST TEMPS IN A LONG TIME
WILL AFFECT CENTRAL INDIANA. READINGS IN THE SINGLE DIGITS OVER
THE NORTHWESTERN THIRD OF THE FORECAST AREA CAN BE EXPECTED...AND
TEENS OVER THE REMAINDER OF CENTRAL INDIANA. THERE WILL BE LITTLE
IMPROVEMENT IN TEMPS TOMORROW DESPITE SOME SUNSHINE. HIGHS ARE
ONLY EXPECTED TO WARM INTO THE 20S. AS SURFACE FLOW BECOMES
SOUTHWESTERLY ON WEDNESDAY NIGHT...TEMPS WILL BECOME SLIGHTLY MORE
MILD THOUGH FOR THE SECOND HALF OF THE SHORT TERM PERIOD WITH
HIGHS IN THE 30S ON THURSDAY...AND LOWS IN THE 20S ON THURSDAY
NIGHT.
ATTENTION THEN TURNS TO ANY PRECIP CHANCES AT THE VERY END OF THE
SHORT TERM PERIOD AS MOISTURE AHEAD OF DESERT SOUTHWEST CUT OFF
LOW MOVES CLOSER TO THE REGION. AS OF NOW...ALL MODELS ARE STILL
TRENDING TOWARD A DRY THURSDAY/THURSDAY NIGHT...AND ARE EVEN
SLOWING DOWN FURTHER WITH THE BULK OF THE PRECIP PROGGED FOR
FRIDAY AND SATURDAY ACROSS CENTRAL INDIANA.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
ISSUED AT 410 AM EST MON DEC 30 2014
THERE IS BETTER AGREEMENT BETWEEN THE MODELS AS THEY ALL BRING
PRECIPITATION NORTH ACROSS OUR ENTIRE REGION FRIDAY NIGHT THROUGH
SATURDAY. PREVIOUSLY THE EURO ONLY BROUGHT IT INTO OUR SOUTHERN
AREAS...WHILE MOST OTHER MODELS BROUGHT IT FARTHER NORTH. WITH THE
EXCEPTION OF THE NAM ALL MODELS HAVE TRENDED A LITTLE SLOWER IN NOT
BEGINNING PRECIPITATION UNTIL FRIDAY NIGHT. WILL GO ALONG WITH THIS
SCENARIO AND KEEP ALL BUT THE FAR SOUTH DRY UNTIL FRIDAY NIGHT.
PRECIPITATION WILL BE THE MAIN ISSUE FRIDAY NIGHT AND SATURDAY AS
MODELS PULL WARMER NORTH INTO OUR REGION. BUFKIT SOUNDINGS
INDICATE LOW CHANCES OF SNOW ACROSS OUR NORTH AND FREEZING
PRECIPITATION SOUTH EARLY FRIDAY NIGHT AND WITH THICKNESS AND
TEMPERATURES RISING SLOWLY OVERNIGHT WHICH SHOULD ALLOW CHANCES OF
FREEZING RAIN TO SPREAD NORTH BY SATURDAY MORNING AND THEN
PRECIPITATION BEING MOSTLY RAIN SATURDAY AFTERNOON. ALL MODELS
INDICATE QUITE A BIT OF PRECIPITATION AROUND SATURDAY AND WENT WITH
HPC PROGS WHICH INDICATED LIKELY POPS CENTRAL AND SOUTH SATURDAY.
AFTER LOW PRESSURE GOES BY...MODELS INDICATE A CHANGEOVER BACK TO
LIGHT SNOW OR FLURRIES SATURDAY NIGHT WITH RETURN OF COLDER AIR.
WILL ALSO MENTION SLIGHT CHANCE OF SNOW SHOWERS WITH MIXED PRECIP
FAR SOUTHEAST SUNDAY MORNING AND THEN DRY AFTER THAT AS COLD HIGH
PRESSURE BUILDS BACK IN.
MADE SOME ADJUSTMENTS TO HOURLY TEMPERATURES FRIDAY NIGHT AND
SATURDAY MORNING AS TEMPERATURES WILL BE NON-DIURNAL.
OTHERWISE...MADE ONLY MINOR TWEAKS TO A MOS BLEND ON TEMPERATURES
MOST OTHER PERIODS.
&&
.AVIATION /DISCUSSION FOR 301500Z KIND TAF UPDATE/...
ISSUED AT 913 AM EST TUE DEC 30 2014
NOT MUCH CHANGE TO PREVIOUS TAF FOR IND. STILL EXPECTING MAINLY
VFR THROUGH THE PERIOD. BASED ON CURRENT OBSERVATIONAL
TRENDS...DID STRENGTHEN THE WINDS SLIGHTLY OVER THE NEXT COUPLE
HOURS AND ALSO DELAYED THE BACKING OF THE SURFACE WINDS. THE
PREVIOUS DISCUSSION FOLLOWS...
ISSUED AT 625 AM AM EST TUE DEC 30 2014
SATELLITE INDICATES BAND OF STRATO CU WITH DRY SECONDARY COLD
FRONT WILL BE MOVING ACROSS TAF SITES TODAY. COULD BE A PERIOD OF
MVFR CEILINGS AT KLAF THIS MORNING...OTHERWISE CEILINGS WILL BE
JUST ABOVE 3 THOUSAND FEET AS BAND MOVES AS IT MOVES ACROSS.
TIMING WILL BE MID MORNING TO MID AFTERNOON AT KLAF AND KHUF AND
MAINLY THIS AFTERNOON AT KIND AND KBMG. OTHERWISE...VFR WITH FEW
CU AND SCATTERED MID CLOUDS. MODEL SOUNDINGS INDICATE CLEARING
SHOULD OCCUR LATE TONIGHT AS ARCTIC HIGH PRESSURE BUILDS INTO THE
GREAT PLAINS.
NORTH WINDS AROUND 10 KNOTS WILL BECOME NORTHWEST THIS AFTERNOON AND
WEST AROUND 5 KNOTS LATE TONIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...TDUD
NEAR TERM...JK
SHORT TERM...TDUD
LONG TERM...JH
AVIATION...MRD/JH
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1001 AM CST TUE DEC 30 2014
.UPDATE...
ISSUED AT 958 AM CST TUE DEC 30 2014
NO UPDATE PLANNED AT THIS TIME.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 332 AM CST TUE DEC 30 2014
COLDEST CORE OF AIRMASS IS OVER THE FCST AREA CURRENTLY. A SHORT
WAVE TROUGH MOVING SOUTHWARD NOW ALONG THE CANADIAN BORDER AND
BEHIND IT BEGINS SLOW WARMING AT THE 850 MB LEVEL LATER TODAY AND
TONIGHT. HOW MUCH WARMING WILL THERE BE AT THE SFC REMAINS A
QUESTION. TRENDED TOWARD HIGHER GUIDANCE VALUES AS GFS/NAM MOS
TEMPS TOO COLD AS MANY AREAS HAVE LIGHT OR MINIMAL SNOW COVER.
TO START THE DAY...THERE IS A BAND OF CLOUDS ALONG LEADING EDGE OF
THE SHORT WAVE...AND THIS WILL DROP SOUTHWARD THRU THE FCST
AREA..LASTING 2-3 HOURS AT ANY ONE PLACE. RAP MODEL 850 RH FIELD
SHOWS ITS PROGRESSION NICELY. BEHIND IT IT WILL CLEAR OUT AGAIN.
SO THE BALANCE OF THE DAY WILL SEE CONSIDERABLE SUN AND WINDS WILL
TURN A BIT MORE WESTERLY. WITH THIS IN MIND DID RAISE MAX TEMPS A
FEW DEGREES TO VERY NEAR YESTERDAY`S READINGS WITH ZERO TO 5 ABOVE
IN THE IMMEDIATE RRV AND SE ND/WCNTRL MN TO ZERO TO BELOW DVL
BASIN AND PARTS OF NW MN ESP AWAY FROM THICKEST FORESTS. HOURLY
TEMP AND WIND FCST INDICATE MOST AREAS OUT OF WC ADVISORY 18Z OR
SO SO WILL LEAVE THAT IN PLACE.
ALLOWED SOME FALL OFF IN TEMPS TONIGHT BUT NOT MUCH AS RISING
TEMPS EXPECTED ALONG WITH A BREEZY WEST WIND. WIND CHILLS SHOULD
BARELY DROP INTO THE ADV RANGE THIS EVENING BEFORE WARMING KICKS
IN. AREA OFFICES HOLDING OFF ON ANY NEW WIND CHILL ADV AS SO MUCH
DEPENDS ON HOW WARM IT GETS LATER TODAY AND HOW MUCH TEMP FALLS
EARLY THIS EVENING BEFORE SFC WARMING BEGINS.
SHORT WAVE WILL DIVE SOUTH THRU NW ONTARIO AND TOWARD MN ARROWHEAD
WEDNESDAY. THICKER CLOUD COVER LIKELY NORTH CENTRAL-NORTHEASTERN
MN WITH MORE OF A PARTLY CLOUDY REGIME FARTHER WEST. 850 TEMPS
DON/T FALL MUCH WEDNESDAY SO NET RESULT WILL BE WARMER AFTN HIGHS
WITH TEENS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 332 AM CST TUE DEC 30 2014
AS ADVERTISED FOR THE PAST FEW DAYS...A WEAK SHORT WAVE WILL DIVE
SOUTHEAST FROM ALBERTA AND ACROSS NORTH DAKOTA AND INTO MINNESOTA
WED NIGHT INTO THURSDAY SPREADING A BAND OF LIGHT SNOW WITH
AMOUNTS UNDER 1 INCH.
FOR FRIDAY THROUGH TUESDAY...GFS AND ECMWF HAVE COME INTO CLOSE AGREEMENT
FOR THE START OF THE PERIOD WITH A MEAN H5 TROF AXIS EXTENDING
FROM A HUDSONS BAY LOW INTO THE EASTERN GREAT LAKES WITH A REX
BLOCK ALONG THE WESTERN NOAM COAST RESULTING IN SPLIT H5 FLOW OVER
THE CONUS...A PATTERN WHICH THEN PERSISTS THROUGH THE PERIOD. THUS
WITH NORTHWEST FLOW OVER THE NORTHERN PLAINS WE STAND A GOOD
CHANCE FOR MEASURABLE SNOW /A FEW INCHES/ FROM FRIDAY EVENING
INTO SATURDAY... WITH MARKEDLY COOLER TEMPS AND ADDITIONAL
FLURRIES THROUGH THE EARLY PART OF NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 700 AM CST TUE DEC 30 2014
BAND OF VFR CLOUD COVER DROPPING SOUTH. AT 13Z CLOUD BAND WAS
CARRINGTON TO GRAND FORKS TO WASKISH. CLEARING BEHIND THIS CLOUD
BAND IN NE ND...BUT SCATTERED CLOUDS REMAIN IN SOUTHEASTERN
MANITOBA. TIMED CLOUD BAND SOUTHWARD THROUGH THE MORNING INTO
FARGO THEN A FEW HOURS OF SCATTERED CLOUDS THEN CLEAR. SOME CIRRUS
SPILLING SOUTH TONIGHT. WEST TO NORTHWEST WIND 10 TO 15 KTS TODAY
INCREASING 15 TO 25 KTS IN NRN VALLEY OVERNIGHT.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WIND CHILL ADVISORY UNTIL NOON CST TODAY FOR NDZ006>008-014>016-
024-026>030-038-039-049-052>054.
MN...WIND CHILL ADVISORY UNTIL NOON CST TODAY FOR MNZ001>009-013>017-
022>024-027>032-040.
&&
$$
UPDATE...DK
SHORT TERM...RIDDLE
LONG TERM...GUST/RIDDLE
AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
709 AM CST TUE DEC 30 2014
.UPDATE...
ISSUED AT 700 AM CST TUE DEC 30 2014
NO UPDATES.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 332 AM CST TUE DEC 30 2014
COLDEST CORE OF AIRMASS IS OVER THE FCST AREA CURRENTLY. A SHORT
WAVE TROUGH MOVING SOUTHWARD NOW ALONG THE CANADIAN BORDER AND
BEHIND IT BEGINS SLOW WARMING AT THE 850 MB LEVEL LATER TODAY AND
TONIGHT. HOW MUCH WARMING WILL THERE BE AT THE SFC REMAINS A
QUESTION. TRENDED TOWARD HIGHER GUIDANCE VALUES AS GFS/NAM MOS
TEMPS TOO COLD AS MANY AREAS HAVE LIGHT OR MINIMAL SNOW COVER.
TO START THE DAY...THERE IS A BAND OF CLOUDS ALONG LEADING EDGE OF
THE SHORT WAVE...AND THIS WILL DROP SOUTHWARD THRU THE FCST
AREA..LASTING 2-3 HOURS AT ANY ONE PLACE. RAP MODEL 850 RH FIELD
SHOWS ITS PROGRESSION NICELY. BEHIND IT IT WILL CLEAR OUT AGAIN.
SO THE BALANCE OF THE DAY WILL SEE CONSIDERABLE SUN AND WINDS WILL
TURN A BIT MORE WESTERLY. WITH THIS IN MIND DID RAISE MAX TEMPS A
FEW DEGREES TO VERY NEAR YESTERDAY`S READINGS WITH ZERO TO 5 ABOVE
IN THE IMMEDIATE RRV AND SE ND/WCNTRL MN TO ZERO TO BELOW DVL
BASIN AND PARTS OF NW MN ESP AWAY FROM THICKEST FORESTS. HOURLY
TEMP AND WIND FCST INDICATE MOST AREAS OUT OF WC ADVISORY 18Z OR
SO SO WILL LEAVE THAT IN PLACE.
ALLOWED SOME FALL OFF IN TEMPS TONIGHT BUT NOT MUCH AS RISING
TEMPS EXPECTED ALONG WITH A BREEZY WEST WIND. WIND CHILLS SHOULD
BARELY DROP INTO THE ADV RANGE THIS EVENING BEFORE WARMING KICKS
IN. AREA OFFICES HOLDING OFF ON ANY NEW WIND CHILL ADV AS SO MUCH
DEPENDS ON HOW WARM IT GETS LATER TODAY AND HOW MUCH TEMP FALLS
EARLY THIS EVENING BEFORE SFC WARMING BEGINS.
SHORT WAVE WILL DIVE SOUTH THRU NW ONTARIO AND TOWARD MN ARROWHEAD
WEDNESDAY. THICKER CLOUD COVER LIKELY NORTH CENTRAL-NORTHEASTERN
MN WITH MORE OF A PARTLY CLOUDY REGIME FARTHER WEST. 850 TEMPS
DONT FALL MUCH WEDNESDAY SO NET RESULT WILL BE WARMER AFTN HIGHS
WITH TEENS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 332 AM CST TUE DEC 30 2014
AS ADVERTISED FOR THE PAST FEW DAYS...A WEAK SHORT WAVE WILL DIVE
SOUTHEAST FROM ALBERTA AND ACROSS NORTH DAKOTA AND INTO MINNESOTA
WED NIGHT INTO THURSDAY SPREADING A BAND OF LIGHT SNOW WITH
AMOUNTS UNDER 1 INCH.
FOR FRIDAY THROUGH TUESDAY...GFS AND ECMWF HAVE COME INTO CLOSE AGREEMENT
FOR THE START OF THE PERIOD WITH A MEAN H5 TROF AXIS EXTENDING
FROM A HUDSONS BAY LOW INTO THE EASTERN GREAT LAKES WITH A REX
BLOCK ALONG THE WESTERN NOAM COAST RESULTING IN SPLIT H5 FLOW OVER
THE CONUS...A PATTERN WHICH THEN PERSISTS THROUGH THE PERIOD. THUS
WITH NORTHWEST FLOW OVER THE NORTHERN PLAINS WE STAND A GOOD
CHANCE FOR MEASASUREABLE SNOW /A FEW INCHES/ FROM FRIDAY EVENING
INTO SATURDAY... WITH MARKEDLY COOLER TEMPS AND ADDITIONAL
FLURRIES THROUGH THE EARLY PART OF NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 700 AM CST TUE DEC 30 2014
BAND OF VFR CLOUD COVER DROPPING SOUTH. AT 13Z CLOUD BAND WAS
CARRINGTON TO GRAND FORKS TO WASKISH. CLEARING BEHIND THIS CLOUD
BAND IN NE ND...BUT SCATTERED CLOUDS REMAIN IN SOUTHEASTERN
MANITOBA. TIMED CLOUD BAND SOUTHWARD THROUGH THE MORNING INTO
FARGO THEN A FEW HOURS OF SCATTERED CLOUDS THEN CLEAR. SOME CIRRUS
SPILLING SOUTH TONIGHT. WEST TO NORTHWEST WIND 10 TO 15 KTS TODAY
INCREASING 15 TO 25 KTS IN NRN VALLEY OVERNIGHT.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WIND CHILL ADVISORY UNTIL NOON CST TODAY FOR NDZ006>008-014>016-
024-026>030-038-039-049-052>054.
MN...WIND CHILL ADVISORY UNTIL NOON CST TODAY FOR MNZ001>009-013>017-
022>024-027>032-040.
&&
$$
UPDATE...RIDDLE
SHORT TERM...RIDDLE
LONG TERM...GUST/RIDDLE
AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
921 AM CST TUE DEC 30 2014
.UPDATE...
ISSUED A WINTER WEATHER ADVISORY FOR FREEZING DRIZZLE ON THE
CAPROCK UNTIL NOON. MAY NEED TO EXTEND THIS AFTERNOON...AND IF SO
WILL CONSIDER GOING THROUGH MUCH OF THE NIGHT. VERY COLD AIR
MOVING SOUTHWARD SHOULD CHANGE FREEZING DRIZZLE MORE TO LIGHT SNOW
AND PERHAPS LESS ICE ACCUMULATIONS BUT NOT CERTAIN AT THIS TIME. RMCQUEEN
&&
.PREV DISCUSSION... /ISSUED 544 AM CST TUE DEC 30 2014/
UPDATE...
KLBB 88D SHOWING THE EXPANSION OF VERY LIGHT REFLECTIVTY /ZERO TO
MINUS 15 DBZ/ BTWN 1000 AND 5000 FT AGL AND LOWERING WITH TIME.
THIS SHOULD BE THE PERIOD OF VERY LIGHT FLURRIES AND/OR FREEZING
DRIZZLE ASSOCIATED WITH FRONTOGENTICAL FORCING. PER THE HRRR THIS
PRECIP SHOULD SHIFT SWD WITH THE FORCING THROUGH THE MORNING.
EXPECTATION IS IT SHOULD REMAIN TOO LIGHT CAUSE MUCH IN THE WAY OF
DIFFICULTY THIS MORNING...BUT WILL CONTINUE TO MONITOR TRENDS.
AVIATION...
CIGS TO LOWER A BIT MORE DURING THE FIRST PART OF THE FCST PERIOD
BUT SHOULD REMAIN MVFR THEN REMAIN PRETTY STABLE THROUGH THE
REMAINDER OF THE PERIOD. ANTICIPATE SOME PERIODS OF LIGHT FREEZING
DRIZZLE AND/OR FLURRIES THROUGH THE FCST TIME AS WELL. GUSTY NNE
WINDS THROUGH MUCH OF THE DAY SHOULD RELAX TOWARD EVENING.
PREV DISCUSSION... /ISSUED 428 AM CST TUE DEC 30 2014/
SHORT TERM...
THE COLD FRONT IS NOW WELL INTO THE PERMIAN BASIN AND BIG COUNTRY
WITH MUCH COLDER AIR FILTERING IN BEHIND IT RATHER THAN SURGING AT
THIS POINT. WITH A GOOD STRATUS DECK NOW IN PLACE...ALTHOUGH
NOT TERRIBLY LOW AT ABOUT 2000 FT AGL...AND LOW LEVEL COLD ADVECTION
PERSISTING THROUGH THE DAY...TEMPS WILL HAVE TROUBLE MOVING OFF OF
MORNING LOWS. INDEED...WILL LIKELY SEE TEMPS FALL THROUGH ABOUT
MID-MORNING BEFORE SOME SLIGHT RECOVERY LATER IN THE DAY.
HOWEVER...MAIN FOCUS CONTINUES TO BE ON CHANCE FOR VERY LIGHT
PRECIPITATION TODAY AND TONIGHT AND POTENTIAL IMPACTS OF IT WITH
TEMPS IN THE TEENS AND 20S. THIS PRECIP EVENT CONTINUES TO LOOK
PRIMARILY ISENTROPIC DRIVEN WITH SOME MINOR CONTRIBUTION FROM
FRONTOGENETICAL FORCING EARLY ON. ISENTROPIC PROJECTIONS DEPICT LIFT
INITIALLY AT THE VERY TOP OF THE COLD AIR...PRIMARILY IN THE WARMER
AND DRIER MID LEVELS ABOVE IT. HOWEVER...AS THE COLD AIR DEEPENS
THROUGH THE DAY...SOME OF THIS COLD MOISTURE SHOULD BE TAPPED BY THE
ISENTROPIC LIFT TO PRODUCE SOME LIGHT PRECIP. BEST WINDOW FOR THIS
APPEARS TO BE BETWEEN 3 PM AND MIDNIGHT...AFTER WHICH ISENTROPIC
LIFT WEAKENS SIGNIFICANTLY. QUESTION THEN BECOMES PHASE OF THIS
PRECIPITATION. PROGGED SOUNDINGS SUPPORT EITHER FREEZING DRIZZLE OR
VERY LIGHT SNOW. COLDER LOW LEVELS ACROSS THE NORTH AND WEST MIGHT
END UP FAVORING FLURRIES TO A DUSTING OF SNOW WHILE FURTHER SOUTH
AND EAST FREEZING DRIZZLE LIKELY TO BE PREDOMINANT. HOW MUCH IS A
BIG QUESTION WITH SOUNDINGS SUGGESTING THE MODEL QPF OUTPUT IS
OVERDONE.
AS FOR POTENTIAL FOR ADVISORY...STILL SOME DETAILS TO WORK OUT SUCH
AS FLURRIES VS DRIZZLE AND TIMING OF ONSET OF PRECIP HEAVY AND/OR
WIDESPREAD ENOUGH TO BEGIN TO CAUSE TRAVEL ISSUES. SINCE CURRENT
EXPECTATION IS THE MORE SIGNIFICANT PART OF THE EVENT IS STILL 8-12
HOURS AWAY AND ANOTHER MODEL RUN AND 12Z UA ANALYSIS SHOULD HELP
NARROW DOWN THE DETAILS FURTHER...WILL DEFER ON THE ISSUANCE OF AN
ADVISORY ATTM.
LONG TERM...
AN UA DISTURBANCE ACROSS THE GREAT BASIN IS STILL PROGGED TO PINCH
OFF AND DIVE SSE TO ACROSS SRN CALI TOMORROW...AND ACROSS THE DESERT
SW ON THURSDAY. AS SUCH...FLOW ALOFT WILL EVOLVE FROM A BROAD
CYCLONIC FLOW TO SWRLY FLOW. IF THE ANTICIPATED TRACK OF THE SYSTEM
DOES NOT CHANGE...IT WILL MOVE DIRECTLY ACROSS THE SOUTHERN PLAINS
FRIDAY NIGHT THEN EXIT TO THE NE BY SATURDAY. THEREAFTER...DRY NW
FLOW ALOFT WILL PREVAIL.
TEMPS STRUGGLING TO GET OUT OF THE 20S WILL CHARACTERIZE WEDNESDAY
AS THE CAA USHERED IN BY LAST NIGHT/S COLD FRONTAL PASSAGE REMAINS
ENTRENCHED. FURTHERMORE...MAY ALSO EXPERIENCE A LINGERING FREEZING
DRIZZLE/WINTRY MIX...COURTESY OF MOISTENED ATMOSPHERIC LOW LEVELS
AND AN UPSLOPE SFC REGIME. THIS WINTRY MIX MAY BE HARD-PRESSED TO
REACH THE GROUND AS IT WILL HAVE TO FALL THROUGH RATHER DRY
MID-LEVELS...WHICH IS WHERE THE SLIVER OF UL SUPPORT IS MAXIMIZED.
ON THURSDAY DURING THE DAY...A SIMILAR SCENARIO TO WEDNESDAY WILL
PLAY OUT...WITH THE DIFFERENCE BEING PROGGED MODEL SOUNDINGS HINTING
AT A WARM TONGUE DEVELOPING IN THE MID-LEVELS...THUS SUGGESTING
MORE OF A FREEZING RAIN/WINTRY MIX OCCURRENCE. NONETHELESS...THE
BEST LIFT IS STILL MAXIMIZED WITHIN THE DRY MID-LEVELS AND HENCE LIGHT
PRECIP IS EXPECTED. BY THURSDAY NIGHT HOWEVER...MID-LEVELS ARE
SHOWN TO MOISTEN AS THE UA SYSTEM DRAWS NEAR. THE BEST UL SUPPORT
IS FINALLY TAPPING INTO ADEQUATE MOISTURE. MID-LEVEL MOISTENING
OCCURRING WITHIN THE DENDRITIC ZONE COULD PROMOTE A CHANCE OF
SNOW...PARTICULARLY ACROSS THE HIGHER TERRAIN OF THE NWRN ZONES.
ELSEWHERE...FREEZING RAIN AND PERHAPS SLEET WILL BE COMMON...WITH
THE EXCEPTION OF THE FAR ROLLING PLAINS WHERE A MIX OF A COLD RAIN
AND FREEZING RAIN MAY OCCUR...GIVEN TEMPS WILL WARM TO SLIGHTLY
ABOVE FREEZING THERE /LOWER 30S ELSEWHERE/. TEMPS WILL WARMUP
FURTHER ON FRIDAY...INTO THE MIDDLE TO UPPER 30S ON THE CAPROCK
TO UPPER 30S TO LOWER 40S OFF THE CAPROCK...WHICH WILL AFFECT THE
PRECIP PHASE. COULD THEREFORE SEE MORE OF A RAIN AND SNOW MIX OR A
RAIN AND FREEZING RAIN MIX DEVELOP BY THE EVENING /THE NWRN ZONES
WILL BE THE EXCEPTION AS SOUNDING PROFILES SUGGEST LIGHT SNOW
THERE/.
LATE FRIDAY NIGHT-EARLY SATURDAY MORNING...LARGE SCALE ASCENT WILL
BE FLEETING AS THE SYSTEM COMMENCE TO EXIT THE REGION. PERHAPS SOME
LINGERING RAIN AND SNOW MIX WILL BE POSSIBLE ACROSS PORTIONS OF THE
ROLLING PLAINS EARLY SATURDAY MORNING. THEREAFTER...DRY NW FLOW
ALOFT WILL PREVAIL AND THE RETURN TO SRLY SFC FLOW EARLY NEXT
WEEK WILL AID IN PUSHING TEMPS BACK UP TO NEAR 50.
NOTE: ALTHOUGH THE WINTRY PRECIP IS EXPECTED TO BE LIGHT THIS
WEEK...IT COULD STILL POSE A THREAT FOR HAZARDOUS ROAD
CONDITIONS AS A THIN GLAZE OF ICE COULD FORM ACROSS OVERPASSES AND
BRIDGES IN PARTICULAR. AS YOU HEAD OUT TO ENJOY THE NEW YEAR
FESTIVITIES...CAUTION IS ADVISED. CHECK BACK TO STAY ALERT AND UP TO
DATE WITH ANY WEATHER CHANGES.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 20 11 22 17 32 / 30 40 20 10 20
TULIA 22 13 22 19 32 / 30 40 10 10 20
PLAINVIEW 23 14 23 19 32 / 30 40 10 10 20
LEVELLAND 24 16 24 19 32 / 40 50 20 20 20
LUBBOCK 25 16 25 21 32 / 40 50 20 20 20
DENVER CITY 27 18 25 20 33 / 40 50 20 20 30
BROWNFIELD 27 18 25 20 33 / 40 50 20 20 30
CHILDRESS 28 18 25 22 34 / 30 40 10 10 20
SPUR 28 18 25 22 33 / 30 50 20 20 30
ASPERMONT 30 20 27 24 36 / 30 40 20 20 30
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR THE FOLLOWING
ZONES: TXZ021>024-027>030-033>036-039>042.
&&
$$
05/99
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
725 AM CST TUE DEC 30 2014
.UPDATE...ONE FINAL UPDATE TO EXPAND DENSE FOG ADVISORY WEST TO
THE RIO GRANDE.
&&
.PREV DISCUSSION... /ISSUED 613 AM CST TUE DEC 30 2014/
AVIATION...
LIFR/VLIFR VIS AND CIGS IN AUSTIN AND SAN ANTONIO THIS MORNING
WILL CONTINUE UNTIL MID-MORNING WHEN NORTHWESTERLY WINDS PICK UP.
THEN MVFR/IFR CIGS THROUGH THE REST OF THE TAF PERIOD. DRT WILL
DROP TO IFR SHORTLY AND STAY THAT WAY UNTIL AROUND 18Z. EXPECTING
PRECIPITATION WEDNESDAY MORNING AT DRT. HAVE NOT INCLUDED ANY
PRECIP IN AUSTIN OR SAN ANTONIO...BUT THERE IS A SLIGHT CHANCE FOR
RAIN. IF THERE IS ANY RAIN IT WILL DROP VIS TO MVFR.
PREV DISCUSSION... /ISSUED 523 AM CST TUE DEC 30 2014/
UPDATE...SECOND UPDATE TO EXPAND DENSE FOG ADVISORY FARTHER WEST
AND SOUTH BASED ON SATELLITE AND WEB CAM TRENDS. THIS ALSO LINES
UP WELL WITH HRRR EXPANSION OF FOG.
PREV DISCUSSION... /ISSUED 443 AM CST TUE DEC 30 2014/
UPDATE...QUICK UPDATE TO ISSUE DENSE FOG ADVISORY FOR I-35
CORRIDOR FROM COMAL TO WILLIAMSON COUNTY EASTWARD. THIS IS BASED ON
SEVERAL WEBCAMS AND OBS INDICATING DENSE FOG. THERE IS ALSO THE
POTENTIAL FOR PATCHY TO AREAS OF DENSE FOG SOUTH AND WEST OF THE
ADVISORY AREA THROUGH THE MORNING.
PREV DISCUSSION... /ISSUED 401 AM CST TUE DEC 30 2014/
SHORT TERM (TODAY THROUGH WEDNESDAY)...AREAS OF LOW STRATUS AND
FOG HAVE FORMED ACROSS EASTERN AREAS AS WELL AS ALONG THE RIO
GRANDE EARLY THIS MORNING. THE FOG AND CLOUDS WILL CONTINUE TO
EXPAND INTO THE I-35 CORRIDOR AND PORTIONS OF THE HILL COUNTRY
THROUGH THE MORNING HOURS.
THE MUCH ADVERTISED ARCTIC AIRMASS HAS MOVED THROUGH THE HILL
COUNTRY AND INTO WEST TEXAS. THE AIRMASS IN RELATIVELY DENSE
BEHIND A 1055MB HIGH ANALYZED UP IN MONTANA. THE AIRMASS WILL
GRADUALLY FILTER INTO SOUTH-CENTRAL TEXAS TODAY AND TONIGHT.
ISENTROPIC ASCENT ABOVE THE SHALLOW...COLD AIRMASS WELL DEVELOP
TONIGHT AND GRADUALLY STRENGTHEN WEDNESDAY AND WEDNESDAY NIGHT.
INITIALLY THICK CLOUDS WILL RESULT FROM THIS...WITH ONLY PATCHY
DRIZZLE AND PATCHY LIGHT RAIN DEVELOPING ACROSS THE WESTERN CWA
TONIGHT AND EXPANDING EAST ON WEDNESDAY. THE GFS CONTINUES TO BE
DRIER IN THE LOWEST LEVELS TODAY THROUGH WEDNESDAY...TAKING LONGER
TO MOISTEN. HOWEVER FORECAST SOUNDINGS FROM THE HRRR/ARW/NMM AS
WELL AS NAM12 ARE NOT QUITE AS AGGRESSIVE WITH THIS DRY LAYER AND
MOISTENS FASTER. HAVE FOLLOWED SLIGHTLY CLOSER TO THE LATTER. THIS
COULD POTENTIALLY RESULT IN PATCHY FREEZING DRIZZLE AND FREEZING
LIGHT RAIN ALONG AND NORTH OF A PANDALE TO LEAKY TO JOHNSON CITY
TO BURNET LINE EARLY WEDNESDAY MORNING. QPF AMOUNTS SHOULD BE VERY
LIGHT...AND GIVEN GROUND TEMPS AND PATCHY COVERAGE IMPACTS SHOULD
BE LIMITED TO ELEVATED SURFACES WITH MINIMAL TRAVEL IMPACTS.
ON WEDNESDAY VERY LITTLE DIURNAL TEMPERATURE RANGE IS EXPECTED...
WITH HIGHS ONLY CLIMBING INTO THE MID 30S ACROSS THE HILL COUNTRY
(WITH A FEW ISOLATED HILL COUNTRY SPOTS REMAINING IN THE LOW
30S)...UPPER 30S ALONG THE I-35 CORRIDOR AND LOW 40S ALONG THE RIO
GRANDE AS WELL AS FAR SOUTHERN/SOUTHEAST AREAS.
LONG TERM (WEDNESDAY NIGHT THROUGH MONDAY)...
FREEZING RAIN WITH TRAVEL IMPACTS POSSIBLE LATE NEW YEARS EVE
INTO NEW YEARS DAY ACROSS THE HILL COUNTRY. WINTER STORM WATCH POSTED...
THE UPPER LEVEL LOW ACROSS SOUTHERN CALIFORNIA IS FORECAST TO
MOVE EAST INTO ARIZONA NEW YEARS EVE NIGHT INTO NEW YEARS DAY. THE
ISENTROPIC UPGLIDE OVER THE COLD AIRMASS STRENGTHENS WEST TO EAST
DURING THIS TIME. SEVERAL MODELS HAVE BEEN INDICATING FOR A FEW
RUNS NOW A MID AND UPPER LEVEL SHORTWAVE IN THE SOUTHWEST FLOW
ALOFT MOVING OUT OF MEXICO AND INTO WEST-CENTRAL TEXAS AND THE
HILL COUNTRY LATE WEDNESDAY NIGHT AND THURSDAY. GFS AND ECMWF BOTH
SHOW ENHANCED BAND OF QPF CLIPPING THE HILL COUNTRY...ALONG WITH
SREF OUTPUT. CONFIDENCE CONTINUES TO GROW IN FREEZING RAIN EVENT
LATE WEDNESDAY NIGHT THROUGH MIDDAY THURSDAY ACROSS AT LEAST THE
HILL COUNTRY. THE WARM CLOUD LAYER DEPTH IS INCREASING DURING THIS
TIME...BUT CAN NOT COMPLETELY RULE OUT SLEET MIXING IN ACROSS THE
NORTHERN HILL COUNTRY AS WELL. GIVEN HOLIDAY TRAVEL SENSITIVITY...
AND AFTER COORDINATION WITH SURROUNDING WFOS...WE HAVE DECIDED TO
ISSUE A WINTER STORM WATCH FOR THE HILL COUNTRY...ALONG AND NORTH
OF A VAL VERDE TO BANDERA TO BURNET COUNTY LINE. IF TEMPS AND
ENHANCEMENT IN QPF VERIFY...THERE COULD BE A BAND ACROSS THE
NORTHERN HILL COUNTRY OF HIGHER ICE ACCUMULATION AMOUNTS.
FARTHER EAST ALONG THE I-35 CORRIDOR...TEMPERATURES WILL BE VERY
CLOSE TO FREEZING EARLY THURSDAY MORNING. ALTHOUGH THESE COUNTIES
ARE NOT CURRENTLY IN THE WATCH...THE FREEZING RAIN LINE IS
FORECAST TO REACH A HELOTES TO WIMBERLEY TO GEORGETOWN LINE. ANY
TRENDS DOWNWARD IN THE TEMP FORECAST...OR WET-BULB COOLING...COULD
PUSH THIS LINE TOWARDS THE AUSTIN AND NORTHERN SAN ANTONIO METRO
AREAS. THOSE WITH TRAVEL PLANS NEW YEARS EVE NIGHT INTO NEW YEARS
DAY ALONG THE INTERSTATE 35 CORRIDOR SHOULD CLOSELY MONITOR FOR
ANY FORECASTS UPDATES.
MODELS ARE SLIGHTLY SLOWER WITH HOW FAST THE UPPER LEVEL LOW
EJECTS OUT INTO THE PLAINS FROM RUNS A FEW DAYS AGO. THE UPPER
LEVEL LOW MOVES ACROSS SOUTHERN NEW MEXICO FRIDAY AND NORTHEAST
THROUGH WEST TEXAS FRIDAY NIGHT INTO SATURDAY MORNING. GOOD
CHANCES FOR RAIN WILL CONTINUE ACROSS THE REGION THURSDAY NIGHT
THROUGH FRIDAY NIGHT. THE WARM CLOUD LAYER CONTINUES TO WARM
FURTHER WITH SLIGHT MODIFICATION IN THE COLD AIRMASS BELOW. PRECIP
WILL REMAIN ALL LIQUID DURING THIS TIME (ALTHOUGH MAY HAVE TO
WATCH CLOSELY ACROSS FAR NORTHERN AREAS OF THE CWA THURSDAY
NIGHT). IN ADDITION...THERE WILL ALSO BE THE POTENTIAL FOR
EMBEDDED THUNDER THURSDAY NIGHT THROUGH FRIDAY NIGHT AS ELEVATED
LAPSE RATES STEEPEN...AND HAVE CONTINUED THIS IN THE FORECAST.
CLEARING AND DRYING TAKES PLACE DOES EVENTUALLY TAKE PLACE
WEST TO EAST SATURDAY WITH HIGHS TEMPS WARMING BACK TO TOWARDS
SEASONABLE LEVELS OVER THE WEEKEND AND INTO EARLY NEXT WEEK.
JR
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 52 34 38 34 40 / 10 10 20 30 60
AUSTIN BERGSTROM INTL AIRPORT 52 35 38 34 40 / 10 10 20 30 60
NEW BRAUNFELS MUNI AIRPORT 54 36 38 34 39 / 10 10 20 30 50
BURNET MUNI AIRPORT 48 30 36 29 37 / 10 10 20 30 60
DEL RIO INTL AIRPORT 54 36 41 33 44 / 10 40 30 30 20
GEORGETOWN MUNI AIRPORT 49 32 36 31 38 / 10 10 20 30 60
HONDO MUNI AIRPORT 56 36 39 33 42 / 10 20 20 30 40
SAN MARCOS MUNI AIRPORT 53 35 38 34 40 / 10 10 20 30 60
LA GRANGE - FAYETTE REGIONAL 55 36 41 36 42 / 10 10 20 30 50
SAN ANTONIO INTL AIRPORT 55 36 39 35 41 / 10 10 20 30 50
STINSON MUNI AIRPORT 56 38 39 36 41 / 10 10 20 30 50
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR THE FOLLOWING
COUNTIES: ATASCOSA...BANDERA...BASTROP...BEXAR...BLANCO...BURNET...
CALDWELL...COMAL...DIMMIT...EDWARDS...FAYETTE...FRIO...GILLESPIE...
GONZALES...GUADALUPE...HAYS...KENDALL...KERR...KINNEY...LEE...
LLANO...MAVERICK...MEDINA...REAL...TRAVIS...UVALDE...VAL VERDE...
WILLIAMSON...WILSON...ZAVALA.
WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY MORNING
FOR THE FOLLOWING COUNTIES: BANDERA...BLANCO...BURNET...EDWARDS...
GILLESPIE...KENDALL...KERR...LLANO...REAL...VAL VERDE.
&&
$$
MESOSCALE/AVIATION...05
SYNOPTIC/GRIDS...76
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
613 AM CST TUE DEC 30 2014
.AVIATION...
LIFR/VLIFR VIS AND CIGS IN AUSTIN AND SAN ANTONIO THIS MORNING
WILL CONTINUE UNTIL MID-MORNING WHEN NORTHWESTERLY WINDS PICK UP.
THEN MVFR/IFR CIGS THROUGH THE REST OF THE TAF PERIOD. DRT WILL
DROP TO IFR SHORTLY AND STAY THAT WAY UNTIL AROUND 18Z. EXPECTING
PRECIPITATION WEDNESDAY MORNING AT DRT. HAVE NOT INCLUDED ANY
PRECIP IN AUSTIN OR SAN ANTONIO...BUT THERE IS A SLIGHT CHANCE FOR
RAIN. IF THERE IS ANY RAIN IT WILL DROP VIS TO MVFR.
&&
.PREV DISCUSSION... /ISSUED 523 AM CST TUE DEC 30 2014/
UPDATE...SECOND UPDATE TO EXPAND DENSE FOG ADVISORY FARTHER WEST
AND SOUTH BASED ON SATELLITE AND WEB CAM TRENDS. THIS ALSO LINES
UP WELL WITH HRRR EXPANSION OF FOG.
PREV DISCUSSION... /ISSUED 443 AM CST TUE DEC 30 2014/
UPDATE...QUICK UPDATE TO ISSUE DENSE FOG ADVISORY FOR I-35
CORRIDOR FROM COMAL TO WILLIAMSON COUNTY EASTWARD. THIS IS BASED ON
SEVERAL WEBCAMS AND OBS INDICATING DENSE FOG. THERE IS ALSO THE
POTENTIAL FOR PATCHY TO AREAS OF DENSE FOG SOUTH AND WEST OF THE
ADVISORY AREA THROUGH THE MORNING.
PREV DISCUSSION... /ISSUED 401 AM CST TUE DEC 30 2014/
SHORT TERM (TODAY THROUGH WEDNESDAY)...AREAS OF LOW STRATUS AND
FOG HAVE FORMED ACROSS EASTERN AREAS AS WELL AS ALONG THE RIO
GRANDE EARLY THIS MORNING. THE FOG AND CLOUDS WILL CONTINUE TO
EXPAND INTO THE I-35 CORRIDOR AND PORTIONS OF THE HILL COUNTRY
THROUGH THE MORNING HOURS.
THE MUCH ADVERTISED ARCTIC AIRMASS HAS MOVED THROUGH THE HILL
COUNTRY AND INTO WEST TEXAS. THE AIRMASS IN RELATIVELY DENSE
BEHIND A 1055MB HIGH ANALYZED UP IN MONTANA. THE AIRMASS WILL
GRADUALLY FILTER INTO SOUTH-CENTRAL TEXAS TODAY AND TONIGHT.
ISENTROPIC ASCENT ABOVE THE SHALLOW...COLD AIRMASS WELL DEVELOP
TONIGHT AND GRADUALLY STRENGTHEN WEDNESDAY AND WEDNESDAY NIGHT.
INITIALLY THICK CLOUDS WILL RESULT FROM THIS...WITH ONLY PATCHY
DRIZZLE AND PATCHY LIGHT RAIN DEVELOPING ACROSS THE WESTERN CWA
TONIGHT AND EXPANDING EAST ON WEDNESDAY. THE GFS CONTINUES TO BE
DRIER IN THE LOWEST LEVELS TODAY THROUGH WEDNESDAY...TAKING LONGER
TO MOISTEN. HOWEVER FORECAST SOUNDINGS FROM THE HRRR/ARW/NMM AS
WELL AS NAM12 ARE NOT QUITE AS AGGRESSIVE WITH THIS DRY LAYER AND
MOISTENS FASTER. HAVE FOLLOWED SLIGHTLY CLOSER TO THE LATTER. THIS
COULD POTENTIALLY RESULT IN PATCHY FREEZING DRIZZLE AND FREEZING
LIGHT RAIN ALONG AND NORTH OF A PANDALE TO LEAKY TO JOHNSON CITY
TO BURNET LINE EARLY WEDNESDAY MORNING. QPF AMOUNTS SHOULD BE VERY
LIGHT...AND GIVEN GROUND TEMPS AND PATCHY COVERAGE IMPACTS SHOULD
BE LIMITED TO ELEVATED SURFACES WITH MINIMAL TRAVEL IMPACTS.
ON WEDNESDAY VERY LITTLE DIURNAL TEMPERATURE RANGE IS EXPECTED...
WITH HIGHS ONLY CLIMBING INTO THE MID 30S ACROSS THE HILL COUNTRY
(WITH A FEW ISOLATED HILL COUNTRY SPOTS REMAINING IN THE LOW
30S)...UPPER 30S ALONG THE I-35 CORRIDOR AND LOW 40S ALONG THE RIO
GRANDE AS WELL AS FAR SOUTHERN/SOUTHEAST AREAS.
LONG TERM (WEDNESDAY NIGHT THROUGH MONDAY)...
FREEZING RAIN WITH TRAVEL IMPACTS POSSIBLE LATE NEW YEARS EVE
INTO NEW YEARS DAY ACROSS THE HILL COUNTRY. WINTER STORM WATCH POSTED...
THE UPPER LEVEL LOW ACROSS SOUTHERN CALIFORNIA IS FORECAST TO
MOVE EAST INTO ARIZONA NEW YEARS EVE NIGHT INTO NEW YEARS DAY. THE
ISENTROPIC UPGLIDE OVER THE COLD AIRMASS STRENGTHENS WEST TO EAST
DURING THIS TIME. SEVERAL MODELS HAVE BEEN INDICATING FOR A FEW
RUNS NOW A MID AND UPPER LEVEL SHORTWAVE IN THE SOUTHWEST FLOW
ALOFT MOVING OUT OF MEXICO AND INTO WEST-CENTRAL TEXAS AND THE
HILL COUNTRY LATE WEDNESDAY NIGHT AND THURSDAY. GFS AND ECMWF BOTH
SHOW ENHANCED BAND OF QPF CLIPPING THE HILL COUNTRY...ALONG WITH
SREF OUTPUT. CONFIDENCE CONTINUES TO GROW IN FREEZING RAIN EVENT
LATE WEDNESDAY NIGHT THROUGH MIDDAY THURSDAY ACROSS AT LEAST THE
HILL COUNTRY. THE WARM CLOUD LAYER DEPTH IS INCREASING DURING THIS
TIME...BUT CAN NOT COMPLETELY RULE OUT SLEET MIXING IN ACROSS THE
NORTHERN HILL COUNTRY AS WELL. GIVEN HOLIDAY TRAVEL SENSITIVITY...
AND AFTER COORDINATION WITH SURROUNDING WFOS...WE HAVE DECIDED TO
ISSUE A WINTER STORM WATCH FOR THE HILL COUNTRY...ALONG AND NORTH
OF A VAL VERDE TO BANDERA TO BURNET COUNTY LINE. IF TEMPS AND
ENHANCEMENT IN QPF VERIFY...THERE COULD BE A BAND ACROSS THE
NORTHERN HILL COUNTRY OF HIGHER ICE ACCUMULATION AMOUNTS.
FARTHER EAST ALONG THE I-35 CORRIDOR...TEMPERATURES WILL BE VERY
CLOSE TO FREEZING EARLY THURSDAY MORNING. ALTHOUGH THESE COUNTIES
ARE NOT CURRENTLY IN THE WATCH...THE FREEZING RAIN LINE IS
FORECAST TO REACH A HELOTES TO WIMBERLEY TO GEORGETOWN LINE. ANY
TRENDS DOWNWARD IN THE TEMP FORECAST...OR WET-BULB COOLING...COULD
PUSH THIS LINE TOWARDS THE AUSTIN AND NORTHERN SAN ANTONIO METRO
AREAS. THOSE WITH TRAVEL PLANS NEW YEARS EVE NIGHT INTO NEW YEARS
DAY ALONG THE INTERSTATE 35 CORRIDOR SHOULD CLOSELY MONITOR FOR
ANY FORECASTS UPDATES.
MODELS ARE SLIGHTLY SLOWER WITH HOW FAST THE UPPER LEVEL LOW
EJECTS OUT INTO THE PLAINS FROM RUNS A FEW DAYS AGO. THE UPPER
LEVEL LOW MOVES ACROSS SOUTHERN NEW MEXICO FRIDAY AND NORTHEAST
THROUGH WEST TEXAS FRIDAY NIGHT INTO SATURDAY MORNING. GOOD
CHANCES FOR RAIN WILL CONTINUE ACROSS THE REGION THURSDAY NIGHT
THROUGH FRIDAY NIGHT. THE WARM CLOUD LAYER CONTINUES TO WARM
FURTHER WITH SLIGHT MODIFICATION IN THE COLD AIRMASS BELOW. PRECIP
WILL REMAIN ALL LIQUID DURING THIS TIME (ALTHOUGH MAY HAVE TO
WATCH CLOSELY ACROSS FAR NORTHERN AREAS OF THE CWA THURSDAY
NIGHT). IN ADDITION...THERE WILL ALSO BE THE POTENTIAL FOR
EMBEDDED THUNDER THURSDAY NIGHT THROUGH FRIDAY NIGHT AS ELEVATED
LAPSE RATES STEEPEN...AND HAVE CONTINUED THIS IN THE FORECAST.
CLEARING AND DRYING TAKES PLACE DOES EVENTUALLY TAKE PLACE
WEST TO EAST SATURDAY WITH HIGHS TEMPS WARMING BACK TO TOWARDS
SEASONABLE LEVELS OVER THE WEEKEND AND INTO EARLY NEXT WEEK.
JR
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 52 34 38 34 40 / 10 10 20 30 60
AUSTIN BERGSTROM INTL AIRPORT 52 35 38 34 40 / 10 10 20 30 60
NEW BRAUNFELS MUNI AIRPORT 54 36 38 34 39 / 10 10 20 30 50
BURNET MUNI AIRPORT 48 30 36 29 37 / 10 10 20 30 60
DEL RIO INTL AIRPORT 54 36 41 33 44 / 10 40 30 30 20
GEORGETOWN MUNI AIRPORT 49 32 36 31 38 / 10 10 20 30 60
HONDO MUNI AIRPORT 56 36 39 33 42 / 10 20 20 30 40
SAN MARCOS MUNI AIRPORT 53 35 38 34 40 / 10 10 20 30 60
LA GRANGE - FAYETTE REGIONAL 55 36 41 36 42 / 10 10 20 30 50
SAN ANTONIO INTL AIRPORT 55 36 39 35 41 / 10 10 20 30 50
STINSON MUNI AIRPORT 56 38 39 36 41 / 10 10 20 30 50
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY MORNING
FOR THE FOLLOWING COUNTIES: BANDERA...BLANCO...BURNET...EDWARDS...
GILLESPIE...KENDALL...KERR...LLANO...REAL...VAL VERDE.
DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR THE FOLLOWING
COUNTIES: ATASCOSA...BANDERA...BASTROP...BEXAR...BLANCO...BURNET...
CALDWELL...COMAL...DIMMIT...FAYETTE...FRIO...GILLESPIE...GONZALES...
GUADALUPE...HAYS...KENDALL...KERR...LEE...LLANO...MEDINA...TRAVIS...
UVALDE...WILLIAMSON...WILSON...ZAVALA.
&&
$$
MESOSCALE/AVIATION...05
SYNOPTIC/GRIDS...76
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
544 AM CST TUE DEC 30 2014
.UPDATE...
KLBB 88D SHOWING THE EXPANSION OF VERY LIGHT REFLECTIVTY /ZERO TO
MINUS 15 DBZ/ BTWN 1000 AND 5000 FT AGL AND LOWERING WITH TIME.
THIS SHOULD BE THE PERIOD OF VERY LIGHT FLURRIES AND/OR FREEZING
DRIZZLE ASSOCIATED WITH FRONTOGENTICAL FORCING. PER THE HRRR THIS
PRECIP SHOULD SHIFT SWD WITH THE FORCING THROUGH THE MORNING.
EXPECTATION IS IT SHOULD REMAIN TOO LIGHT CAUSE MUCH IN THE WAY OF
DIFFICULTY THIS MORNING...BUT WILL CONTINUE TO MONITOR TRENDS.
&&
.AVIATION...
CIGS TO LOWER A BIT MORE DURING THE FIRST PART OF THE FCST PERIOD
BUT SHOULD REMAIN MVFR THEN REMAIN PRETTY STABLE THROUGH THE
REMAINDER OF THE PERIOD. ANTICIPATE SOME PERIODS OF LIGHT FREEZING
DRIZZLE AND/OR FLURRIES THROUGH THE FCST TIME AS WELL. GUSTY NNE
WINDS THROUGH MUCH OF THE DAY SHOULD RELAX TOWARD EVENING.
&&
.PREV DISCUSSION... /ISSUED 428 AM CST TUE DEC 30 2014/
SHORT TERM...
THE COLD FRONT IS NOW WELL INTO THE PERMIAN BASIN AND BIG COUNTRY
WITH MUCH COLDER AIR FILTERING IN BEHIND IT RATHER THAN SURGING AT
THIS POINT. WITH A GOOD STRATUS DECK NOW IN PLACE...ALTHOUGH
NOT TERRIBLY LOW AT ABOUT 2000 FT AGL...AND LOW LEVEL COLD ADVECTION
PERSISTING THROUGH THE DAY...TEMPS WILL HAVE TROUBLE MOVING OFF OF
MORNING LOWS. INDEED...WILL LIKELY SEE TEMPS FALL THROUGH ABOUT
MID-MORNING BEFORE SOME SLIGHT RECOVERY LATER IN THE DAY.
HOWEVER...MAIN FOCUS CONTINUES TO BE ON CHANCE FOR VERY LIGHT
PRECIPITATION TODAY AND TONIGHT AND POTENTIAL IMPACTS OF IT WITH
TEMPS IN THE TEENS AND 20S. THIS PRECIP EVENT CONTINUES TO LOOK
PRIMARILY ISENTROPIC DRIVEN WITH SOME MINOR CONTRIBUTION FROM
FRONTOGENETICAL FORCING EARLY ON. ISENTROPIC PROJECTIONS DEPICT LIFT
INITIALLY AT THE VERY TOP OF THE COLD AIR...PRIMARILY IN THE WARMER
AND DRIER MID LEVELS ABOVE IT. HOWEVER...AS THE COLD AIR DEEPENS
THROUGH THE DAY...SOME OF THIS COLD MOISTURE SHOULD BE TAPPED BY THE
ISENTROPIC LIFT TO PRODUCE SOME LIGHT PRECIP. BEST WINDOW FOR THIS
APPEARS TO BE BETWEEN 3 PM AND MIDNIGHT...AFTER WHICH ISENTROPIC
LIFT WEAKENS SIGNIFICANTLY. QUESTION THEN BECOMES PHASE OF THIS
PRECIPITATION. PROGGED SOUNDINGS SUPPORT EITHER FREEZING DRIZZLE OR
VERY LIGHT SNOW. COLDER LOW LEVELS ACROSS THE NORTH AND WEST MIGHT
END UP FAVORING FLURRIES TO A DUSTING OF SNOW WHILE FURTHER SOUTH
AND EAST FREEZING DRIZZLE LIKELY TO BE PREDOMINANT. HOW MUCH IS A
BIG QUESTION WITH SOUNDINGS SUGGESTING THE MODEL QPF OUTPUT IS
OVERDONE.
AS FOR POTENTIAL FOR ADVISORY...STILL SOME DETAILS TO WORK OUT SUCH
AS FLURRIES VS DRIZZLE AND TIMING OF ONSET OF PRECIP HEAVY AND/OR
WIDESPREAD ENOUGH TO BEGIN TO CAUSE TRAVEL ISSUES. SINCE CURRENT
EXPECTATION IS THE MORE SIGNIFICANT PART OF THE EVENT IS STILL 8-12
HOURS AWAY AND ANOTHER MODEL RUN AND 12Z UA ANALYSIS SHOULD HELP
NARROW DOWN THE DETAILS FURTHER...WILL DEFER ON THE ISSUANCE OF AN
ADVISORY ATTM.
LONG TERM...
AN UA DISTURBANCE ACROSS THE GREAT BASIN IS STILL PROGGED TO PINCH
OFF AND DIVE SSE TO ACROSS SRN CALI TOMORROW...AND ACROSS THE DESERT
SW ON THURSDAY. AS SUCH...FLOW ALOFT WILL EVOLVE FROM A BROAD
CYCLONIC FLOW TO SWRLY FLOW. IF THE ANTICIPATED TRACK OF THE SYSTEM
DOES NOT CHANGE...IT WILL MOVE DIRECTLY ACROSS THE SOUTHERN PLAINS
FRIDAY NIGHT THEN EXIT TO THE NE BY SATURDAY. THEREAFTER...DRY NW
FLOW ALOFT WILL PREVAIL.
TEMPS STRUGGLING TO GET OUT OF THE 20S WILL CHARACTERIZE WEDNESDAY
AS THE CAA USHERED IN BY LAST NIGHT/S COLD FRONTAL PASSAGE REMAINS
ENTRENCHED. FURTHERMORE...MAY ALSO EXPERIENCE A LINGERING FREEZING
DRIZZLE/WINTRY MIX...COURTESY OF MOISTENED ATMOSPHERIC LOW LEVELS
AND AN UPSLOPE SFC REGIME. THIS WINTRY MIX MAY BE HARD-PRESSED TO
REACH THE GROUND AS IT WILL HAVE TO FALL THROUGH RATHER DRY
MID-LEVELS...WHICH IS WHERE THE SLIVER OF UL SUPPORT IS MAXIMIZED.
ON THURSDAY DURING THE DAY...A SIMILAR SCENARIO TO WEDNESDAY WILL
PLAY OUT...WITH THE DIFFERENCE BEING PROGGED MODEL SOUNDINGS HINTING
AT A WARM TONGUE DEVELOPING IN THE MID-LEVELS...THUS SUGGESTING
MORE OF A FREEZING RAIN/WINTRY MIX OCCURRENCE. NONETHELESS...THE
BEST LIFT IS STILL MAXIMIZED WITHIN THE DRY MID-LEVELS AND HENCE LIGHT
PRECIP IS EXPECTED. BY THURSDAY NIGHT HOWEVER...MID-LEVELS ARE
SHOWN TO MOISTEN AS THE UA SYSTEM DRAWS NEAR. THE BEST UL SUPPORT
IS FINALLY TAPPING INTO ADEQUATE MOISTURE. MID-LEVEL MOISTENING
OCCURRING WITHIN THE DENDRITIC ZONE COULD PROMOTE A CHANCE OF
SNOW...PARTICULARY ACROSS THE HIGHER TERRAIN OF THE NWRN ZONES.
ELSEWHERE...FREEZING RAIN AND PERHAPS SLEET WILL BE COMMON...WITH
THE EXCEPTION OF THE FAR ROLLING PLAINS WHERE A MIX OF A COLD RAIN
AND FREEZING RAIN MAY OCCUR...GIVEN TEMPS WILL WARM TO SLIGHTLY
ABOVE FREEZING THERE /LOWER 30S ELSEWHERE/. TEMPS WILL WARMUP
FURTHER ON FRIDAY...INTO THE MIDDLE TO UPPER 30S ON THE CAPROCK
TO UPPER 30S TO LOWER 40S OFF THE CAPROCK...WHICH WILL AFFECT THE
PRECIP PHASE. COULD THEREFORE SEE MORE OF A RAIN AND SNOW MIX OR A
RAIN AND FREEZING RAIN MIX DEVELOP BY THE EVENING /THE NWRN ZONES
WILL BE THE EXCEPTION AS SOUNDING PROFILES SUGGEST LIGHT SNOW
THERE/.
LATE FRIDAY NIGHT-EARLY SATURDAY MORNING...LARGE SCALE ASCENT WILL
BE FLEETING AS THE SYSTEM COMMENCE TO EXIT THE REGION. PERHAPS SOME
LINGERING RAIN AND SNOW MIX WILL BE POSSIBLE ACROSS PORTIONS OF THE
ROLLING PLAINS EARLY SATURDAY MORNING. THEREAFTER...DRY NW FLOW
ALOFT WILL PREVAIL AND THE RETURN TO SRLY SFC FLOW EARLY NEXT
WEEK WILL AID IN PUSHING TEMPS BACK UP TO NEAR 50.
NOTE: ALTHOUGH THE WINTRY PRECIP IS EXPECTED TO BE LIGHT THIS
WEEK...IT COULD STILL POSE A THREAT FOR HAZARDOUS ROAD
CONDITIONS AS A THIN GLAZE OF ICE COULD FORM ACROSS OVERPASSES AND
BRIDGES IN PARTICULAR. AS YOU HEAD OUT TO ENJOY THE NEW YEAR
FESTIVITIES...CAUTION IS ADVISED. CHECK BACK TO STAY ALERT AND UP TO
DATE WITH ANY WEATHER CHANGES.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 20 11 22 17 32 / 30 40 20 10 20
TULIA 22 13 22 19 32 / 30 40 10 10 20
PLAINVIEW 23 14 23 19 32 / 30 40 10 10 20
LEVELLAND 24 16 24 19 32 / 40 50 20 20 20
LUBBOCK 25 16 25 20 32 / 40 50 20 20 20
DENVER CITY 27 18 25 20 33 / 40 50 20 20 30
BROWNFIELD 27 18 25 20 33 / 40 50 20 20 30
CHILDRESS 28 18 25 22 34 / 20 40 10 10 20
SPUR 28 18 25 22 33 / 30 50 20 20 30
ASPERMONT 30 20 27 24 36 / 20 40 20 20 30
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
07/29/07
AREA FORECAST DISCUSSION
NWS MIDLAND/ODESSA TX
541 AM CST Tue Dec 30 2014
.DISCUSSION...
&&
.AVIATION...
Strong front has moved through the region with a gusty N/NE wind
in its wake... gusts should continue through the day. Low clouds
have reached most TAF sites and will remain through the day with
low MVFR/IFR conditions. Expect a wintry precipitation to develop
with freezing rain... freezing drizzle... and sleet along with
some fog to reduce vsbys.
&&
.PREV DISCUSSION... /ISSUED 512 AM CST Tue Dec 30 2014/
DISCUSSION...As of 5:00 AM CST Tuesday...Sfc obs indc that the
Arctic Front has made it to the Trans Pecos...and continues to
surge south. Low clouds have quickly filled in behind the front
with low overcast past Wink per sfc obs and satl imagery.
Winter weather will be the rule into the New Year. Mild air will
override the cold low level airmass. With the lack of jet
dynamics isentropic lift will lead to periods of light freezing
rain and sleet right thru Wednesday aftn...and possibly into New
Years Day. The HRRR model is indc precipitation moving thru the
Permian Basin and Southeast New Mexico this morning and moving
south of the Pecos River by late morning. Temps will slowly fall
through the day with below freezing temps thru New Years Eve. Due
to the extended nature of this event and the substantial impacts
to holiday travel have upgraded the Winter Storm Watch to a Winter
Storm Warning. The warning will continue thru Wed aftn for West
Texas and Southeast New Mexico...except for the Presidio Valley
where temps could be a little warmer. Strong sfc pressure gradient
will lead to high winds thru Guadalupe Pass...the High Wind Watch
has been upgraded to a High Wind Warning continuing into Wednesday
morning. A combination of gusty winds and very cold temperatures
could lead to wind chill values in the single digits in the Plains
tonight...with dangerous wind chill values as low as -10F in the
Guadalupe Mtns.
An upper low over SoCal will move slowly east into Southeast New
Mexico Friday night. Light freezing rain and sleet could continue
into New Years morning. It is possible that the Winter Storm
Warning might need to be extended into New Years morning. Milder
air should change the precipitation to rain New Years aftn.
However...the ECMWF is showing a deeper cold airmass moving back
into the CWA bringing a chance of snow Thursday night...and a
chance of a rain/snow mix Friday and Friday night.
As the upper low moves east of the CWA...the upcoming weekend will
be dry but cool. Southwest flow sfc and aloft will bring dry
weather along with a warming trend the beginning of next week.
Strobin
&&
.MAF WATCHES/WARNINGS/ADVISORIES...
NM...WINTER STORM WARNING until 5 PM MST Wednesday FOR THE FOLLOWING
ZONES... Central Lea County...Eddy County Plains...
Guadalupe Mountains of Eddy County...Northern Lea County...
Southern Lea County.
TX...WINTER STORM WARNING until 6 PM CST /5 PM MST/ Wednesday FOR THE
FOLLOWING ZONES... Andrews...Big Bend Area...Borden...
Crane...Davis/Apache Mountains Area...Dawson...Ector...
Gaines...Glasscock...Guadalupe Mountains...Howard...
Loving...Marfa Plateau...Martin...Midland...Mitchell...
Pecos...Reagan...Reeves County and Upper Trans Pecos...
Scurry...Terrell...Upton...Van Horn and Highway 54
Corridor...Ward...Winkler.
HIGH WIND WARNING until 8 AM MST Wednesday FOR THE FOLLOWING
ZONES... Guadalupe Mountains.
&&
$$
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AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
523 AM CST TUE DEC 30 2014
.UPDATE...SECOND UPDATE TO EXPAND DENSE FOG ADVISORY FARTHER WEST
AND SOUTH BASED ON SATELLITE AND WEB CAM TRENDS. THIS ALSO LINES
UP WELL WITH HRRR EXPANSION OF FOG.
&&
.PREV DISCUSSION... /ISSUED 443 AM CST TUE DEC 30 2014/
UPDATE...QUICK UPDATE TO ISSUE DENSE FOG ADVISORY FOR I-35
CORRIDOR FROM COMAL TO WILLIMSON COUNTY EASTWARD. THIS IS BASED ON
SEVERAL WEBCAMS AND OBS INDICATING DENSE FOG. THERE IS ALSO THE
POTENTIAL FOR PATCHY TO AREAS OF DENSE FOG SOUTH AND WEST OF THE
ADVISORY AREA THROUGH THE MORNING.
PREV DISCUSSION... /ISSUED 401 AM CST TUE DEC 30 2014/
SHORT TERM (TODAY THROUGH WEDNESDAY)...AREAS OF LOW STRATUS AND
FOG HAVE FORMED ACROSS EASTERN AREAS AS WELL AS ALONG THE RIO
GRANDE EARLY THIS MORNING. THE FOG AND CLOUDS WILL CONTINUE TO
EXPAND INTO THE I-35 CORRIDOR AND PORTIONS OF THE HILL COUNTRY
THROUGH THE MORNING HOURS.
THE MUCH ADVERTISED ARCTIC AIRMASS HAS MOVED THROUGH THE HILL
COUNTRY AND INTO WEST TEXAS. THE AIRMASS IN RELATIVELY DENSE
BEHIND A 1055MB HIGH ANALYZED UP IN MONTANA. THE AIRMASS WILL
GRADUALLY FILTER INTO SOUTH-CENTRAL TEXAS TODAY AND TONIGHT.
ISENTROPIC ASCENT ABOVE THE SHALLOW...COLD AIRMASS WELL DEVELOP
TONIGHT AND GRADUALLY STRENGTHEN WEDNESDAY AND WEDNESDAY NIGHT.
INITIALLY THICK CLOUDS WILL RESULT FROM THIS...WITH ONLY PATCHY
DRIZZLE AND PATCHY LIGHT RAIN DEVELOPING ACROSS THE WESTERN CWA
TONIGHT AND EXPANDING EAST ON WEDNESDAY. THE GFS CONTINUES TO BE
DRIER IN THE LOWEST LEVELS TODAY THROUGH WEDNESDAY...TAKING LONGER
TO MOISTEN. HOWEVER FORECAST SOUNDINGS FROM THE HRRR/ARW/NMM AS
WELL AS NAM12 ARE NOT QUITE AS AGGRESSIVE WITH THIS DRY LAYER AND
MOISTENS FASTER. HAVE FOLLOWED SLIGHTLY CLOSER TO THE LATTER. THIS
COULD POTENTIALLY RESULT IN PATCHY FREEZING DRIZZLE AND FREEZING
LIGHT RAIN ALONG AND NORTH OF A PANDALE TO LEAKY TO JOHNSON CITY
TO BURNET LINE EARLY WEDNESDAY MORNING. QPF AMOUNTS SHOULD BE VERY
LIGHT...AND GIVEN GROUND TEMPS AND PATCHY COVERAGE IMPACTS SHOULD
BE LIMITED TO ELEVATED SURFACES WITH MINIMAL TRAVEL IMPACTS.
ON WEDNESDAY VERY LITTLE DIURNAL TEMPERATURE RANGE IS EXPECTED...
WITH HIGHS ONLY CLIMBING INTO THE MID 30S ACROSS THE HILL COUNTRY
(WITH A FEW ISOLATED HILL COUNTRY SPOTS REMAINING IN THE LOW
30S)...UPPER 30S ALONG THE I-35 CORRIDOR AND LOW 40S ALONG THE RIO
GRANDE AS WELL AS FAR SOUTHERN/SOUTHEAST AREAS.
LONG TERM (WEDNESDAY NIGHT THROUGH MONDAY)...
.FREEZING RAIN WITH TRAVEL IMPACTS POSSIBLE LATE NEW YEARS EVE
INTO NEW YEARS DAY ACROSS THE HILL COUNTRY. WINTER STORM WATCH POSTED...
THE UPPER LEVEL LOW ACROSS SOUTHERN CALIFORNIA IS FORECAST TO
MOVE EAST INTO ARIZONA NEW YEARS EVE NIGHT INTO NEW YEARS DAY. THE
ISENTROPIC UPGLIDE OVER THE COLD AIRMASS STRENGTHENS WEST TO EAST
DURING THIS TIME. SEVERAL MODELS HAVE BEEN INDICATING FOR A FEW
RUNS NOW A MID AND UPPER LEVEL SHORTWAVE IN THE SOUTHWEST FLOW
ALOFT MOVING OUT OF MEXICO AND INTO WEST-CENTRAL TEXAS AND THE
HILL COUNTRY LATE WEDNESDAY NIGHT AND THURSDAY. GFS AND ECMWF BOTH
SHOW ENHANCED BAND OF QPF CLIPPING THE HILL COUNTRY...ALONG WITH
SREF OUTPUT. CONFIDENCE CONTINUES TO GROW IN FREEZING RAIN EVENT
LATE WEDNESDAY NIGHT THROUGH MIDDAY THURSDAY ACROSS AT LEAST THE
HILL COUNTRY. THE WARM CLOUD LAYER DEPTH IS INCREASING DURING THIS
TIME...BUT CAN NOT COMPLETELY RULE OUT SLEET MIXING IN ACROSS THE
NORTHERN HILL COUNTRY AS WELL. GIVEN HOLIDAY TRAVEL SENSITIVITY...
AND AFTER COORDINATION WITH SURROUNDING WFOS...WE HAVE DECIDED TO
ISSUE A WINTER STORM WATCH FOR THE HILL COUNTRY...ALONG AND NORTH
OF A VAL VERDE TO BANDERA TO BURNET COUNTY LINE. IF TEMPS AND
ENHANCEMENT IN QPF VERIFY...THERE COULD BE A BAND ACROSS THE
NORTHERN HILL COUNTRY OF HIGHER ICE ACCUMULATION AMOUNTS.
FARTHER EAST ALONG THE I-35 CORRIDOR...TEMPERATURES WILL BE VERY
CLOSE TO FREEZING EARLY THURSDAY MORNING. ALTHOUGH THESE COUNTIES
ARE NOT CURRENTLY IN THE WATCH...THE FREEZING RAIN LINE IS
FORECAST TO REACH A HELOTES TO WIMBERLY TO GEORGETOWN LINE. ANY
TRENDS DOWNWARD IN THE TEMP FORECAST...OR WET-BULB COOLING...COULD
PUSH THIS LINE TOWARDS THE AUSTIN AND NORTHERN SAN ANTONIO METRO
AREAS. THOSE WITH TRAVEL PLANS NEW YEARS EVE NIGHT INTO NEW YEARS
DAY ALONG THE INTERSTATE 35 CORRIDOR SHOULD CLOSELY MONITOR FOR
ANY FORECASTS UPDATES.
MODELS ARE SLIGHTLY SLOWER WITH HOW FAST THE UPPER LEVEL LOW
EJECTS OUT INTO THE PLAINS FROM RUNS A FEW DAYS AGO. THE UPPER
LEVEL LOW MOVES ACROSS SOUTHERN NEW MEXICO FRIDAY AND NORTHEAST
THROUGH WEST TEXAS FRIDAY NIGHT INTO SATURDAY MORNING. GOOD
CHANCES FOR RAIN WILL CONTINUE ACROSS THE REGION THURSDAY NIGHT
THROUGH FRIDAY NIGHT. THE WARM CLOUD LAYER CONTINUES TO WARM
FURTHER WITH SLIGHT MODIFICATION IN THE COLD AIRMASS BELOW. PRECIP
WILL REMAIN ALL LIQUID DURING THIS TIME (ALTHOUGH MAY HAVE TO
WATCH CLOSELY ACROSS FAR NORTHERN AREAS OF THE CWA THURSDAY
NIGHT). IN ADDITION...THERE WILL ALSO BE THE POTENTIAL FOR
EMBEDDED THUNDER THURSDAY NIGHT THROUGH FRIDAY NIGHT AS ELEVATED
LAPSE RATES STEEPEN...AND HAVE CONTINUED THIS IN THE FORECAST.
CLEARING AND DRYING TAKES PLACE DOES EVENTUALLY TAKE PLACE
WEST TO EAST SATURDAY WITH HIGHS TEMPS WARMING BACK TO TOWARDS
SEASONABLE LEVELS OVER THE WEEKEND AND INTO EARLY NEXT WEEK.
JR
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 52 34 38 34 40 / 10 10 20 30 60
AUSTIN BERGSTROM INTL AIRPORT 52 35 38 34 40 / 10 10 20 30 60
NEW BRAUNFELS MUNI AIRPORT 54 36 38 34 39 / 10 10 20 30 50
BURNET MUNI AIRPORT 48 30 36 29 37 / 10 10 20 30 60
DEL RIO INTL AIRPORT 54 36 41 33 44 / 10 40 30 30 20
GEORGETOWN MUNI AIRPORT 49 32 36 31 38 / 10 10 20 30 60
HONDO MUNI AIRPORT 56 36 39 33 42 / 10 20 20 30 40
SAN MARCOS MUNI AIRPORT 53 35 38 34 40 / 10 10 20 30 60
LA GRANGE - FAYETTE REGIONAL 55 36 41 36 42 / 10 10 20 30 50
SAN ANTONIO INTL AIRPORT 55 36 39 35 41 / 10 10 20 30 50
STINSON MUNI AIRPORT 56 38 39 36 41 / 10 10 20 30 50
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY MORNING
FOR THE FOLLOWING COUNTIES: BANDERA...BLANCO...BURNET...EDWARDS...
GILLESPIE...KENDALL...KERR...LLANO...REAL...VAL VERDE.
DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR THE FOLLOWING
COUNTIES: ATASCOSA...BANDERA...BASTROP...BEXAR...BLANCO...BURNET...
CALDWELL...COMAL...DIMMIT...FAYETTE...FRIO...GILLESPIE...GONZALES...
GUADALUPE...HAYS...KENDALL...KERR...LEE...LLANO...MEDINA...TRAVIS...
UVALDE...WILLIAMSON...WILSON...ZAVALA.
&&
$$
MESOSCALE/AVIATION...05
SYNOPTIC/GRIDS...76
AREA FORECAST DISCUSSION
NWS MIDLAND/ODESSA TX
512 AM CST Tue Dec 30 2014
.DISCUSSION...As of 5:00 AM CST Tuesday...Sfc obs indc that the
Arctic Front has made it to the Trans Pecos...and continues to
surge south. Low clouds have quickly filled in behind the front
with low overcast past Wink per sfc obs and satl imagery.
Winter weather will be the rule into the New Year. Mild air will
override the cold low level airmass. With the lack of jet
dynamics isentropic lift will lead to periods of light freezing
rain and sleet right thru Wednesday aftn...and possibly into New
Years Day. The HRRR model is indc precipitation moving thru the
Permian Basin and Southeast New Mexico this morning and moving
south of the Pecos River by late morning. Temps will slowly fall
through the day with below freezing temps thru New Years Eve. Due
to the extended nature of this event and the substantial impacts
to holiday travel have upgraded the Winter Storm Watch to a Winter
Storm Warning. The warning will continue thru Wed aftn for West
Texas and Southeast New Mexico...except for the Presidio Valley
where temps could be a little warmer. Strong sfc pressure gradient
will lead to high winds thru Guadalupe Pass...the High Wind Watch
has been upgraded to a High Wind Warning continuing into Wednesday
morning. A combination of gusty winds and very cold temperatures
could lead to wind chill values in the single digits in the Plains
tonight...with dangerous wind chill values as low as -10F in the
Guadalupe Mtns.
An upper low over SoCal will move slowly east into Southeast New
Mexico Friday night. Light freezing rain and sleet could continue
into New Years morning. It is possible that the Winter Storm
Warning might need to be extended into New Years morning. Milder
air should change the precipitation to rain New Years aftn.
However...the ECMWF is showing a deeper cold airmass moving back
into the CWA bringing a chance of snow Thursday night...and a
chance of a rain/snow mix Friday and Friday night.
As the upper low moves east of the CWA...the upcoming weekend will
be dry but cool. Southwest flow sfc and aloft will bring dry
weather along with a warming trend the beginning of next week.
Strobin
&&
.PRELIMINARY POINT TEMPS/POPS...
ANDREWS TX 29 20 24 22 / 60 60 50 30
BIG SPRING TX 31 20 24 24 / 60 60 50 30
CARLSBAD NM 31 23 25 23 / 40 60 50 30
DRYDEN TX 41 32 32 29 / 50 60 50 20
FORT STOCKTON TX 32 20 29 25 / 50 60 60 20
GUADALUPE PASS TX 26 14 21 19 / 40 50 60 20
HOBBS NM 29 21 24 21 / 60 60 50 30
MARFA TX 37 19 31 22 / 30 40 50 20
MIDLAND INTL AIRPORT TX 30 19 25 23 / 60 60 50 30
ODESSA TX 29 20 25 23 / 60 60 50 30
WINK TX 32 28 29 26 / 40 60 50 20
&&
.MAF WATCHES/WARNINGS/ADVISORIES...
NM...WINTER STORM WARNING until 5 PM MST Wednesday FOR THE FOLLOWING
ZONES... Central Lea County...Eddy County Plains...
Guadalupe Mountains of Eddy County...Northern Lea County...
Southern Lea County.
TX...WINTER STORM WARNING until 6 PM CST /5 PM MST/ Wednesday FOR THE
FOLLOWING ZONES... Andrews...Big Bend Area...Borden...
Crane...Davis/Apache Mountains Area...Dawson...Ector...
Gaines...Glasscock...Guadalupe Mountains...Howard...
Loving...Marfa Plateau...Martin...Midland...Mitchell...
Pecos...Reagan...Reeves County and Upper Trans Pecos...
Scurry...Terrell...Upton...Van Horn and Highway 54
Corridor...Ward...Winkler.
HIGH WIND WARNING until 8 AM MST Wednesday FOR THE FOLLOWING
ZONES... Guadalupe Mountains.
&&
$$
72/33
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VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS MIAMI FL
430 PM EST TUE DEC 30 2014
...VERY WARM, HUMID PATTERN TO CONTINUE INTO THE NEW YEAR...
.UPDATE...SEA BREEZES HAVE DEVELOPED ALONG BOTH THE GULF AND
ATLANTIC COASTS THIS AFTERNOON...CLEARLY SEEN IN VISIBLE SATELLITE
IMAGERY. PRETTY RARE FOR WINTERTIME! ENOUGH LOW LEVEL MOISTURE IS
PRESENT TO HAVE CU FORMING ALONG THE SEA BREEZE FRONTS, BUT NOT
QUITE ENOUGH TO GET SHOWERS GOING. HRRR IS OVERDOING QPF AS RADAR
CONTINUES TO SHOW NO SHOWER ACTIVITY (ECHOES SOUTH OF LAKE
OKEECHOBEE ARE REFLECTIVE OF SUGARCANE BURNING). AS DAYTIME
HEATING IS LOSS, IT LOOKS LIKE CONDITIONS WILL REMAIN DRY THROUGH
TONIGHT...BUT AS THE WEAKENING COLD FRONT OVER CENTRAL FLORIDA
SAGS SOUTHWARD, SOME CONVERGENCE ALONG THE PALM BEACH COAST COULD
ALLOW FOR A FEW SHOWERS TO DEVELOP THERE LATER TONIGHT...SO KEPT
SHOWER MENTION IN THERE ONLY.
SOUTH FL CONTINUES WITH ABOVE NORMAL TEMPS ALONG WITH
HUMIDITY...AND THIS WILL CONTINUE INTO THE WEEKEND AND EARLY NEXT
WEEK! A RECORD HIGH OF 83F WAS TIED AT MIAMI TODAY. THE HOTTEST
READINGS WERE FROM OPA LOCKA (KOPF) TO PEMBROKE PINES (KHWO) TO
WEST PALM BEACH (KPBI) WHERE HIGHS OFFICIALLY REACHED 85F, THE
WARMEST IN THE COUNTRY (FOR MAJOR REPORTING STATIONS/SOME UPPER
80S WERE REGISTERED BY MESONETS OVER PORTIONS OF INTERIOR SOUTH FL
THIS AFTERNOON).
THE WARM PATTERN WILL CONTINUE WITH POSSIBLY BUILDING HEAT BY THIS
WEEKEND. ECMWF INDICATES MAX TEMPS INTO THE MID-UPPER 80S EAST
COAST METRO WITH DEWPOINTS INTO THE LOWER 70S EQUATING TO HEAT
INDICES INTO THE LOWER 90S! GFS AND MODEL BLENDS OFFER SLIGHTLY
COOLER READINGS...AND THAT`S WHAT OUR CURRENT FORECAST REFLECTS.
HOWEVER, WE VERY WELL MAY NEED TO INCREASE OUR HIGHS PROJECTED FOR
THIS UPCOMING WEEKEND. A POSSIBLE "MINI-HEAT WAVE" TO START 2015.
/GREGORIA
&&
.PREV DISCUSSION... /ISSUED 247 PM EST TUE DEC 30 2014/
SHORT TERM (TONIGHT-NEW YEARS` DAY)...
A MOSTLY ZONAL UPPER FLOW PATTERN WILL CONTINUE ACROSS SOUTH FLORIDA
THROUGH NEW YEARS` DAY AS A STRONG RIDGE REMAINS ACROSS CUBA AND THE
BAHAMA ISLANDS. A WEAK COLD FRONT CURRENTLY IN NORTH CENTRAL
FLORIDA WILL OOZE INTO SOUTH FLORIDA TONIGHT AND WEDNESDAY BEFORE
STALLING AND RAPIDLY BECOME DIFFUSE. THERE WILL BE SOME CLOUDS
WITH THE FRONTAL BOUNDARY BUT VERY LITTLE IN THE WAY OF RAINFALL
AS DEEP LAYER MOISTURE WILL BE LACKING. THERE IS SOME POTENTIAL
FOR FOG AGAIN OVER THE INTERIOR AHEAD OF THE FRONT. HOWEVER,
EXTENSIVE CLOUD COVER WILL LIKELY HAMPER FOG DEVELOPMENT AND WILL
LEAVE OUT OF FORECAST AT THIS TIME WITH THE SREF ONLY SHOWING A
30-40% CHANCE OF VISIBILITY LOWERING LESS THAN THREE MILES. DUE TO
THE LACK OF PUSH WITH THIS FRONT, THE STRONG SUBSIDENCE CAP
CURRENTLY OVER SOUTH FLORIDA WILL BE SLOW TO ERODE WITH FORECAST
SOUNDINGS ONLY INDICATING SOME INSTABILITY BY LATE WEDNESDAY AND
EVEN THEN A PWAT OF ONLY AROUND 1.3".
LONG TERM (FRIDAY-TUESDAY)...
NOT MANY CHANGES SEEN TO THE UPPER FLOW PATTERN IN THE EXTENDED
PERIOD AS THE SUBTROPICAL RIDGE REMAINS FIRMLY ENTRENCHED IN ITS
POSITION ACROSS THE BAHAMA ISLAND CHAIN. AT THE SURFACE, WHAT IS
LEFT OF THE FRONTAL BOUNDARY WILL LIFT BACK TO THE NORTH WEDNESDAY
NIGHT OR THURSDAY. THIS IS IN RESPONSE TO A POWERFUL TROUGH
CURRENTLY DEEPENING INTO THE FOUR CORNERS AREA THAT WILL MOVE INTO
THE CENTRAL/SOUTHERN PLAINS ON FRIDAY NIGHT AND SATURDAY THEN INTO
THE GREAT LAKES AND NEW ENGLAND THIS WEEKEND. A COLD FRONT
ASSOCIATED WITH THIS SYSTEM WILL THEN MOVE INTO NORTH FLORIDA ON
SUNDAY WHERE IT WILL STALL INTO EARLY NEXT WEEK. SO THESE TWO
PARAGRAPHS SPELL OUT A WARM AND GENERALLY DRY PATTERN FOR SOUTH
FLORIDA TO END THIS YEAR AND THE BEGINNING OF THE NEW YEAR.
MARINE...
GOOD BOATING CONDITIONS WILL CONTINUE THROUGH THE FORECAST PERIOD
WITH A LIGHT WIND EXPECTED AND SEAS 4 FEET OR LESS. THE PRESSURE
GRADIENT WILL REMAIN WEAK AS THE COLD FRONT BECOMES DIFFUSE AND
THEN SLOWLY LIFTS TO THE NORTH TOWARDS THE END OF THE WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 69 79 68 78 / 20 40 20 20
FORT LAUDERDALE 70 80 69 79 / 10 30 20 20
MIAMI 70 81 69 80 / 10 20 10 20
NAPLES 66 79 65 79 / 10 20 10 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
300 PM EST TUE DEC 30 2014
.UPDATE (REST OF TODAY THROUGH WEDNESDAY)...
20Z WATER VAPOR AND H4 RAP ANALYSIS CONTINUE TO SHOW MUCH OF THE
NATION UNDER A BROAD LONGWAVE TROUGH. THE MOST ENERGETIC FEATURE
WITHIN THIS TROUGH IS A STRONG SHORTWAVE DROPPING SOUTH THROUGH THE
INTERMOUNTAIN WEST WHICH IS PROGGED BY ALL THE NUMERICAL GUIDANCE TO
BECOME A LARGE CUTOFF LOW OVER THE SOUTHWESTERN STATES BEFORE
EJECTING EASTWARD ACROSS THE SOUTHERN/CENTRAL PLAINS LATER IN THE
WEEK. OUR FORECAST AREA RESIDES WITHIN A ZONE OF DEEP LAYER
SOUTHWEST FLOW BETWEEN THE LONGWAVE TROUGH AND AND WEST-EAST
ORIENTED RIDGE ACROSS THE NORTHWEST CARIBBEAN. A PLUME OF SOUTHERN
STREAM MOISTURE IS STILL IN WV IMAGERY RIDGING THIS FLOW OVER THE
EASTERN GULF OF MEXICO AND FL PENINSULA.
AT THE SURFACE...A WEAK COLD FRONT IS NOW ALIGNED ACROSS THE CENTRAL
FLORIDA PENINSULA AND IS MAKING VERY SLOW PROGRESS SOUTHWARD.
REGIONAL RADARS SHOW A SWATH OF LIGHT SHOWERS AND AREAS OF DRIZZLE
ALONG AND NOW BEHIND THIS BOUNDARY. THIS TRANSITION FROM A KATAFRONT
TO AN ANAFRONT CONFIGURATION HAS HELPED KEEP THE RAIN ACROSS MANY OF
THE SAME PLACES SO FAR TODAY...EVEN THROUGH THE FRONT ITSELF HAS
MADE STEADY PROGRESS TO THE SOUTH SINCE EARLY THIS MORNING.
&&
.SHORT TERM (REST OF TODAY THROUGH WEDNESDAY)...
REST OF TODAY...THE FRONT STILL LOOKS TO SLOWLY SETTLE SOUTH TO NEAR
PUNTA GORDA AROUND SUNSET. THE ORGANIZATION AND COVERAGE OF SHOWERS
HAS DIMINISHED SOMEWHAT IN THE PAST COUPLE OF HOURS AS THE WEAK
SHORTWAVE TO OUR NORTH IS NOW PASSING BY. HOWEVER...THE LOW LEVEL
BOUNDARY FOCUS WILL STILL KEEP THE CHANCE FOR MORE SCT SHOWERS IN
THE FORECAST...GENERALLY SOUTH OF HERNANDO COUNTY AND TO THE NORTH
OF THE SARASOTA TO PUNTA GORDA REGION. ALSO WITH THE FLOW BECOMING
MORE AND MORE PARALLEL TO THE FRONT...THE ACTUALLY BOUNDARY PASSAGE
WILL NOT NECESSARILY END THE CHANCE FOR RAIN. MANY OF THE GUIDANCE
MEMBERS WERE INDICATING THE BOUNDARY TAKING ON AN INCREASINGLY
ANAFRONT CONFIGURATION WHERE BETTER CHANCES FOR THE CLOUDS AND
SHOWERS ARE ACTUALLY ALONG AND BEHIND THE BOUNDARY. THIS APPEARS TO
BE TAKING SHAPE THIS AFTERNOON AS THE FRONT IS NOW DOWN SOUTH OF THE
TAMPA BAY/POLK COUNTY REGION...AND YET MUCH OF THE LIGHT
SHOWERS/DRIZZLE ARE STILL REMAINS ALONG THE GENERAL I-4 CORRIDOR.
FOR OUR FAR NORTHERN ZONES...THE RAIN IS OVER AND DRIER AIR WILL
CONTINUE TO SETTLE BEHIND THE FRONT THROUGH EARLY THIS EVENING.
FOR OUR FAR SOUTHERN ZONES...WELL...THE WITH THE FRONT BECOMING MORE
ANAFRONT WITH TIME...THE SHOWERS SOUTHWARD MARCH AS SLOWED TO A
CRAWL. EVENTUALLY A FEW SHOWERS/PATCHES OF DRIZZLE SHOULD MAKE IT
DOWN TO SARASOTA/PUNTA GORDA AND FORT MYERS...BUT IS LOOKING MORE
LIKELY TO BE TONIGHT THAN DURING THE ACTUAL DAYLIGHT HOURS TODAY.
TONIGHT AND WEDNESDAY...THE FRONT STALLS AND BEGINS TO WASH OUT OVER
THE SOUTHERN PENINSULA. WILL KEEP LOW POPS FOR LIGHT SHOWERS/DRIZZLE
FOR THE FIRST HALF OF THE OVERNIGHT...MAINLY TO THE SOUTH OF THE
TAMPA BAY REGION AND THEN LOOKS AS THROUGH MOST OF THE ACTIVITY
SHOULD FADE. THERE IS GOING TO BE QUITE A BIT OF LOW LEVEL MOISTURE
STILL IN PLACE OVERNIGHT...AND THE SREF AND STATISTICAL GUIDANCE ARE
SHOWING A LOT OF LOWER CLOUDS DEVELOPING. SO EVEN PLACE THAT DO NOT
CLOUD OVER DURING THE DAY FROM THE FRONT ITSELF...SHOULD BEGIN TO
BECOME OVERCAST OVERNIGHT. THESE CLOUDS WILL LIKELY BE WITH US FOR A
GOOD PORTION OF THE DAY ON WEDNESDAY (ESPECIALLY THE FIRST
HALF)...AND HENCE WILL NOT HAVE ALL THAT MUCH SUN IN THE FORECAST
FOR WEDNESDAY. THE GUIDANCE MEMBERS ARE INDICATING THE DEVELOPMENT
OF AN INVERTED TROUGH OVER THE GULF STREAM OFF THE FL EAST COAST
DURING LATER TONIGHT AND EARLY WEDNESDAY THAT THEN MIGRATES WESTWARD
A BIT DURING THE DAY. THIS FOCUS ALONG WITH SOME SPEED CONVERGENCE
ALONG THE COAST LOOKS TO BE ENOUGH FOR SHOWERS TO BEGIN MIGRATING
ONSHORE. NOT IMPOSSIBLE THAT A FEW OF THESE SHOWERS OR SPRINKLES
COULD SURVIVE THE TREK ACROSS THE PENINSULA TO REACH SOME OF OUR
EASTERN AND SOUTHERN ZONES. GOING TO KEEP THE POPS AT OR BELOW 20%
FOR NOW...AND WILL MENTION A FEW SPRINKLES IN THE FORECAST WEDNESDAY
FOR THE SOUTHERN HALF OF THE FORECAST AREA. THOSE SPRINKLES SHOULD
BE GONE BY TOMORROW EVENING...AND AS IT LOOKS NOW...ALTHOUGH A LOT
OF CLOUDS AROUND...THE WEATHER FOR AFTER DARK ON NEW YEARS EVE LOOKS
DRY WITH SEASONABLE TEMPERATURES.
&&
.LONG TERM (THURSDAY THROUGH NEXT TUESDAY)...
ZONAL FLOW ALOFT AND WEAK RIDGING WILL BE IN PLACE TO START THE
PERIOD WITH A REMNANT BOUNDARY DRAPED ACROSS SOUTH FL. THE BOUNDARY
WILL LIFT NORTH OVER THE AREA INTO FRIDAY AS A TROUGH DEVELOPS OVER
THE GULF STREAM JUST OFF THE FL EAST COAST AND A WEAK LOW DEEPENS
OFF OF THE TEXAS COAST IN THE GULF OF MEXICO. THIS WILL ALLOW FOR A
SLIGHT CHANCE OF RAIN WEDNESDAY NIGHT AND THURSDAY. FLOW ALOFT WILL
BECOME SW FOR THE WEEKEND AS WEAK RIDGING BUILDS OVER THE STATE FROM
THE ATLANTIC AND THE LOW OFF OF TEXAS LIFTS NE AND DRAGS A COLD
FRONT INTO THE REGION BY SUNDAY. THE FRONT WILL SETTLE INTO THE AREA
SUNDAY AFTERNOON AND THEN STALL ACROSS THE NORTHERN HALF OF THE
PENINSULA FOR EARLY NEXT WEEK. THIS WILL ALLOW FOR A FEW SHOWERS
MAINLY ACROSS THE NATURE COAST SATURDAY THROUGH SUNDAY...AND INLAND
ACROSS THE AREA MONDAY. TEMPERATURES WILL REMAIN ABOVE NORMAL
THROUGH THE WEEKEND AND FALL A COUPLE OF DEGREES TO CLOSER TO NORMAL
FOR EARLY NEXT WEEK.
&&
.AVIATION...
MVFR TO OCCASIONAL IFR CONDITIONS THIS AFTERNOON FROM KSRQ/KPIE/KTPA
AND KLAL. SOUTH OF THE FRONTAL BAND FROM KPGD TO KRSW WILL CONTINUE
TO SEE PREVAILING VFR CONDITIONS INTO THE EVENING HOURS. GOOD
AGREEMENT AMONG THE DETERMINISTIC AND STATISTICAL GUIDANCE THAT WE
WILL SEE AN EXPANSION OF THE LOWER CLOUDS DURING THE SECOND HALF OF
THE NIGHT INTO WEDNESDAY MORNING. SO ALTHOUGH EVEN THE NORTHERN
TERMINALS MAY SEE A BRIEF WINDOW OF IMPROVEMENT THIS EVENING...GOING
WITH PREVAILING MVFR CIGS FOR ALL TERMINALS AFTER 06Z. IF THE MAV IS
CORRECT THAN PERIODS OF IFR CIGS ARE POSSIBLE. BEST CHANCES TO SEE
ANY FOG/VIS RESTRICTIONS WILL BE DOWN TOWARD KPGD AND KRSW. EXPECT
MVFR CATEGORY CIGS TO HOLD THROUGH MUCH OF THE MORNING AT MANY
SPOTS...IF NOT UNTIL THE END OF THE TAF PERIOD.
&&
.MARINE...
MARINE FORECAST AREA REMAINS DIVIDED WITH IMPACTS ASSOCIATED WITH A
QUASI-STATIONARY FRONTAL SYSTEM DRAPED OVER THE WATERS FROM OFF
HERNANDO BEACH SOUTHWARD TO OFF THE COAST FROM VENICE. MAIN AREA OF
SHOWERS EXTENDS OFF THE COAST OF HOLIDAY AND OUT 100 NM INTO THE
EASTERN GULF OF MEXICO. CONDITIONS EARLY THIS AFTERNOON /2PM/
REPORTS SEAS AROUND 6 FEET WITH A PERIOD OF 5 SECONDS AT BUOY036 112
MILES W-NW OF TAMPA WHILE BUOY03 REPORTS SEAS OF 2 FEET AND A PERIOD
OF 8 SECONDS IN THE CALMER AIRMASS 208 MILES WEST OF NAPLES. NO
FLAGS EXPECTED THROUGH THE PERIOD AND SHOWER ACTIVITY WILL GRADUALLY
DIMINISH TONIGHT.
&&
.FIRE WEATHER...
NO SIGNIFICANT FIRE WEATHER CONCERNS EXPECTED THE NEXT SEVERAL DAYS.
WEAK COLD FRONT WILL EXIT SOUTH OF THE AREA THIS EVENING ALLOWING
SOMEWHAT DRIER AIR TO ARRIVE FROM THE NORTH FOR WEDNESDAY AND
THURSDAY. THEREAFTER...INCREASING TEMPERATURES AND LOW LEVEL
MOISTURE IS EXPECTED FOR THE END OF THE WEEK.
FOG POTENTIAL...
PATCHY FOG IS EXPECTED TO DEVELOP OVERNIGHT...MAINLY TO THE SOUTH OF
THE I-4 CORRIDOR WITH THE BEST CHANCES FOR ANY SIGNIFICANT FOG
OCCURRING FROM AROUND PUNTA GORDA AND SOUTHWARD.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 61 75 60 76 / 40 10 10 10
FMY 65 79 64 80 / 30 20 10 20
GIF 61 76 58 76 / 40 10 10 10
SRQ 63 77 61 77 / 40 10 10 10
BKV 58 74 54 74 / 20 10 20 10
SPG 63 75 61 74 / 40 10 10 10
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/AVIATION/FIRE WX...MROCZKA
LONG TERM...HUBBARD
MARINE...LAMARRE
AREA FORECAST DISCUSSION
NWS POCATELLO ID
155 PM MST TUE DEC 30 2014
.SHORT TERM...TONIGHT THROUGH FRIDAY. AN AMPLIFIED RIDGE OF HIGH
PRESSURE WILL PREVAIL ALONG THE PAC COAST THROUGH THURSDAY
MAINTAINING THE COLD ARCTIC NNE FLOW ACROSS THE REGION. THUS WIND
CHILL WARNINGS WILL CONTINUE ACROSS THE UPPER SNAKE RIVER
PLAIN/HIGHLANDS AND ADJOINING TRIBUTARIES WHERE ELEVATED WIND SPEEDS
WILL CREATE DANGEROUSLY COLD WIND CHILL VALUES. VALLEY FOG AND LOW
CLOUDS OVER BOISE/MOUNTAIN HOME MAY CONTINUE TO BACK UP THE VALLEY
INTO THE LOWER SNAKE RIVER PLAIN/ERN MAGIC VALLEY OVERNIGHT WHICH
MAY ALSO HELP TO MODERATE THE FRIGIDLY COLD TEMPS IN THAT AREA. BY
FRIDAY...THE RIDGE WEAKENS AS A PAC STORM BREAKS INTO WRN CANADA
ENCOURAGING DAYTIME HIGH TEMPERATURES TO WARM TO NEAR NORMAL LEVELS.
HUSTON
.LONG TERM...FRIDAY NIGHT THROUGH NEXT TUESDAY NIGHT. TWO SHORTWAVES
EXPECTED TO MOVE THROUGH CENTRAL AND EASTERN IDAHO...ONE ON THE VERY
FIRST PERIOD (FRI NIGHT)...AND A SECOND FROM LATE SUN THROUGH MON.
THEY BOTH AFFECT MAINLY THE NORTHERN HALF OF THE FORECAST
AREA...WITH NEARLY ZERO PRECIPITATION EXPECTED IN THE SOUTH CENTRAL
HIGHLANDS AND PARTS OF THE EASTERN MAGIC VALLEY. TERRAIN EFFECTS ARE
STRONG...WITH A LIGHT SNOW EVENT EXPECTED IN THE SNAKE RIVER
PLAIN...BUT MODERATE RIGHT NOW FOR THE MOUNTAINS. BY THE END OF THE
PERIOD...AN UPPER LEVEL RIDGE BEGINS TO BUILD INTO SOUTHERN IDAHO.
THIS PUSHES THE STORM TRACK FARTHER NORTH AND AWAY FROM THE GEM
STATE. THERE IS A SHORTWAVE THAT ARRIVES IN THE FINAL 24 HOURS OF
THE FORECAST THAT MAY BRUSH THE IDAHO-MONTANA BORDER REGION...BUT
ITS EFFECTS SHOULD BE SLIGHT. THE UPPER LEVEL LONG WAVE PATTERN IS
ALSO SHIFTING IN THIS WAY...REINFORCING THE LIKELIHOOD OF THE RIDGE
BUILDING INTO IDAHO FOR A DRIER END TO THIS PERIOD. MESSICK
&&
.AVIATION...ARCTIC AIR HAS MOVED IN AND STABILIZED...SO NOT LOOKING
FOR THE GUSTY WIND AGAIN TONIGHT...ALTHOUGH AMBIENT TEMPERATURES
WILL ACTUALLY BE COLDER. THE MAIN FORECAST PROBLEM THOUGH IS WHETHER
OR NOT THE STRATUS EXPECTED BY MOS GUIDANCE WILL APPEAR OR NOT.
TIME-HEIGHT CROSS SECTIONS DO NOT HAVE ANY BOUNDARY LAYER HUMIDITY
THAT EXCEEDS 90 PERCENT EXCEPT FOR KBYI. THIS MORNING THERE WAS A
LARGE STRATUS AREA IN THE TREASURE VALLEY AND WESTERN MAGIC
VALLEY...SO IT IS A CONCERN THAT THE STRATUS COULD SPREAD FROM THERE
INTO THE EASTERN MAGIC VALLEY AND KBYI. THE HRRR AND NAM NOW
INDICATE THAT THE EASTERLY WIND WILL WEAKEN AT KBYI AND GO LIGHT AND
VARIABLE AFTER 31/07Z OR SO...SO THIS WOULD LIKELY BE THE TIME OF
ARRIVAL OF ANY STRATUS. HAVE UPDATED TO PUT THIS INTO THE KBYI TAF.
THE OTHER TWO LOW ELEVATION AIRPORTS COULD STILL EXPERIENCE SOME
STRATUS...BUT BOUNDARY LAYER HUMIDITY IS NOT AS GOOD...SO HAVE PUT
IN A FEW CLOUDS BELOW 1000 FT. KSUN WAS EXPECTED TO BE IN THE
CLEAR...BUT AN AREA OF STRATUS HAS MOVED THROUGH THE SAWTOOTHS AND
IS LYING JUST TO THE SOUTH OF THE KSUN AIRDROME. ANY RETURN TO A
SOUTHERLY COMPONENT TO THE WIND AT KSUN COULD ADVECT THE STRATUS
INTO THE AIRPORT AREA. ONCE WIND THERE SWITCHES BACK TO NORTHWEST
DURING THE EARLY EVENING...THIS SHOULD END THE THREAT TO THE CIG AT
KSUN. MESSICK
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
WIND CHILL WARNING CONTINUES UNTIL NOON WEDNESDAY IDZ019.
WIND CHILL WARNING FROM 8 PM MST THIS EVENING UNTIL NOON WEDNESDAY
IDZ020-021-032.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1243 PM EST TUE DEC 30 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 304 AM EST TUE DEC 30 2014
IN THE NEAR TERM PERIOD...THE FOCUS WILL BE ON THE COOL DOWN AS
ARCTIC HIGH PRESSURE STRENGTHENS OVER WESTERN CANADA. MUCH COLDER
AIR WILL SPILL INTO PORTIONS OF THE CONTINENTAL U.S. AS A RESULT.
HOWEVER...NO PRECIPITATION IS EXPECTED UNTIL THE EXTENDED PERIOD
WHEN A CUT OFF LOW OVER THE DESERT SOUTHWEST MAKES ITS PROGRESSION
ACROSS THE PLAINS...AND INTO CENTRAL INDIANA. TIMING AND TRACKING
INCONSISTENCIES ARE MAKING IT DIFFICULT TO PINPOINT PRECIP TYPE AT
THIS TIME...BUT EARLY INDICATIONS ARE SHOWING MIXED PRECIPITATION
FOR MOST OF FRIDAY AND SATURDAY. PRECIP WILL END FROM WEST TO EAST
ON SUNDAY...AND THE REMAINDER OF THE EXTENDED FORECAST WILL BE DRY
AS FLOW ALOFT BECOMES MORE ZONAL ON MONDAY.
&&
.NEAR TERM /THIS AFTERNOON/...
ISSUED AT 950 AM EST TUE DEC 30 2014
FLURRIES WILL BE REMOVED FROM THE NORTHWEST. EVEN IN CLEAR AIR
MODE THE RADARS UPSTREAM DONT SHOW ANYTHING AND THE HRRR DOESNT
INTRODUCE ANYTHING.
OTHER ELEMENTS OF THE EARLIER FORECAST ARE WORKING WELL BASED ON THE
LATEST OBSERVATIONS.&&
.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
ISSUED AT 304 AM EST TUE DEC 30 2014
THE MAIN FOCUS OF THE SHORT TERM PERIOD CONTINUES TO BE ON
TEMPERATURES AND ANY CHANGES IN TIMING OF DAY 5 STORM SYSTEM
THAT COULD POSSIBLY RESULT IN PRECIP AS EARLY AS THURSDAY NIGHT.
TEMPERATURES WILL REALLY PLUMMET TONIGHT WITH COLD AIR IN PLACE
AND PARTLY CLOUDY SKIES. SOME OF THE COLDEST TEMPS IN A LONG TIME
WILL AFFECT CENTRAL INDIANA. READINGS IN THE SINGLE DIGITS OVER
THE NORTHWESTERN THIRD OF THE FORECAST AREA CAN BE EXPECTED...AND
TEENS OVER THE REMAINDER OF CENTRAL INDIANA. THERE WILL BE LITTLE
IMPROVEMENT IN TEMPS TOMORROW DESPITE SOME SUNSHINE. HIGHS ARE
ONLY EXPECTED TO WARM INTO THE 20S. AS SURFACE FLOW BECOMES
SOUTHWESTERLY ON WEDNESDAY NIGHT...TEMPS WILL BECOME SLIGHTLY MORE
MILD THOUGH FOR THE SECOND HALF OF THE SHORT TERM PERIOD WITH
HIGHS IN THE 30S ON THURSDAY...AND LOWS IN THE 20S ON THURSDAY
NIGHT.
ATTENTION THEN TURNS TO ANY PRECIP CHANCES AT THE VERY END OF THE
SHORT TERM PERIOD AS MOISTURE AHEAD OF DESERT SOUTHWEST CUT OFF
LOW MOVES CLOSER TO THE REGION. AS OF NOW...ALL MODELS ARE STILL
TRENDING TOWARD A DRY THURSDAY/THURSDAY NIGHT...AND ARE EVEN
SLOWING DOWN FURTHER WITH THE BULK OF THE PRECIP PROGGED FOR
FRIDAY AND SATURDAY ACROSS CENTRAL INDIANA.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
ISSUED AT 304 AM EST TUE DEC 30 2014
THE MAIN FOCUS OF THE SHORT TERM PERIOD CONTINUES TO BE ON
TEMPERATURES AND ANY CHANGES IN TIMING OF DAY 5 STORM SYSTEM
THAT COULD POSSIBLY RESULT IN PRECIP AS EARLY AS THURSDAY NIGHT.
TEMPERATURES WILL REALLY PLUMMET TONIGHT WITH COLD AIR IN PLACE
AND PARTLY CLOUDY SKIES. SOME OF THE COLDEST TEMPS IN A LONG TIME
WILL AFFECT CENTRAL INDIANA. READINGS IN THE SINGLE DIGITS OVER
THE NORTHWESTERN THIRD OF THE FORECAST AREA CAN BE EXPECTED...AND
TEENS OVER THE REMAINDER OF CENTRAL INDIANA. THERE WILL BE LITTLE
IMPROVEMENT IN TEMPS TOMORROW DESPITE SOME SUNSHINE. HIGHS ARE
ONLY EXPECTED TO WARM INTO THE 20S. AS SURFACE FLOW BECOMES
SOUTHWESTERLY ON WEDNESDAY NIGHT...TEMPS WILL BECOME SLIGHTLY MORE
MILD THOUGH FOR THE SECOND HALF OF THE SHORT TERM PERIOD WITH
HIGHS IN THE 30S ON THURSDAY...AND LOWS IN THE 20S ON THURSDAY
NIGHT.
ATTENTION THEN TURNS TO ANY PRECIP CHANCES AT THE VERY END OF THE
SHORT TERM PERIOD AS MOISTURE AHEAD OF DESERT SOUTHWEST CUT OFF
LOW MOVES CLOSER TO THE REGION. AS OF NOW...ALL MODELS ARE STILL
TRENDING TOWARD A DRY THURSDAY/THURSDAY NIGHT...AND ARE EVEN
SLOWING DOWN FURTHER WITH THE BULK OF THE PRECIP PROGGED FOR
FRIDAY AND SATURDAY ACROSS CENTRAL INDIANA.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
ISSUED AT 410 AM EST MON DEC 30 2014
THERE IS BETTER AGREEMENT BETWEEN THE MODELS AS THEY ALL BRING
PRECIPITATION NORTH ACROSS OUR ENTIRE REGION FRIDAY NIGHT THROUGH
SATURDAY. PREVIOUSLY THE EURO ONLY BROUGHT IT INTO OUR SOUTHERN
AREAS...WHILE MOST OTHER MODELS BROUGHT IT FARTHER NORTH. WITH THE
EXCEPTION OF THE NAM ALL MODELS HAVE TRENDED A LITTLE SLOWER IN NOT
BEGINNING PRECIPITATION UNTIL FRIDAY NIGHT. WILL GO ALONG WITH THIS
SCENARIO AND KEEP ALL BUT THE FAR SOUTH DRY UNTIL FRIDAY NIGHT.
PRECIPITATION WILL BE THE MAIN ISSUE FRIDAY NIGHT AND SATURDAY AS
MODELS PULL WARMER NORTH INTO OUR REGION. BUFKIT SOUNDINGS
INDICATE LOW CHANCES OF SNOW ACROSS OUR NORTH AND FREEZING
PRECIPITATION SOUTH EARLY FRIDAY NIGHT AND WITH THICKNESS AND
TEMPERATURES RISING SLOWLY OVERNIGHT WHICH SHOULD ALLOW CHANCES OF
FREEZING RAIN TO SPREAD NORTH BY SATURDAY MORNING AND THEN
PRECIPITATION BEING MOSTLY RAIN SATURDAY AFTERNOON. ALL MODELS
INDICATE QUITE A BIT OF PRECIPITATION AROUND SATURDAY AND WENT WITH
HPC PROGS WHICH INDICATED LIKELY POPS CENTRAL AND SOUTH SATURDAY.
AFTER LOW PRESSURE GOES BY...MODELS INDICATE A CHANGEOVER BACK TO
LIGHT SNOW OR FLURRIES SATURDAY NIGHT WITH RETURN OF COLDER AIR.
WILL ALSO MENTION SLIGHT CHANCE OF SNOW SHOWERS WITH MIXED PRECIP
FAR SOUTHEAST SUNDAY MORNING AND THEN DRY AFTER THAT AS COLD HIGH
PRESSURE BUILDS BACK IN.
MADE SOME ADJUSTMENTS TO HOURLY TEMPERATURES FRIDAY NIGHT AND
SATURDAY MORNING AS TEMPERATURES WILL BE NON-DIURNAL.
OTHERWISE...MADE ONLY MINOR TWEAKS TO A MOS BLEND ON TEMPERATURES
MOST OTHER PERIODS.
&&
.AVIATION /DISCUSSION FOR THE 301800Z TAF ISSUANCE/...
ISSUED AT 1233 PM EST TUE DEC 30 2014
MAINLY VFR CONDITIONS EXPECTED THROUGH MOST OF THE TAF PERIOD. THE
ONE CAVEAT TO THAT IS THE BAND OF SCT/BKN MVFR CEILINGS EXISTING
WITHIN THE 2 OR 3 COUNTY WIDE BAND OF CLOUDS CURRENTLY EXTENDING
DOWN FROM NORTH CENTRAL INDIANA THROUGH WEST CENTRAL INDIANA.
UNDERNEATH SOME OF THE MORE CONCENTRATED CLOUD SHIELD...BKN TO
OVC MVFR CEILINGS ARE PERSISTING. EXPECT THOSE MVFR CEILINGS TO
MOVE OUT OF LAF BY 30/20Z AND OUT OF HUF AROUND 30/21Z. DO CURRENTLY
EXPECT TO SEE THOSE MVFR CEILINGS MAKE IT INTO IND AROUND 30/18Z
AND INTO BMG BY 30/19Z AS CU FIELD IS THICKENING ACROSS WEST-
CENTRAL AND CENTRAL PORTIONS OF CENTRAL INDIANA. EXPECT THE MVFR
CEILINGS TO SCATTER OR MOVE FROM IND/BMG BY 30/22-23Z. ALONG WITH
THE INCREASE IN CLOUDS...A GRADUAL BACKING OF WINDS TO THE
NORTHWEST IS EXPECTED AS WELL. WOULD NOT BE SURPRISED TO SEE AN OB
OR TWO FROM LAF WITH -SN SENSING FLURRIES WITHIN THE NEXT FEW
HOURS AS WELL.
OTHERWISE...EXPECT VFR CONDITIONS WITH FEW/SCT CU AND A SCATTERED
MID-LEVEL DECK. MODEL SOUNDINGS CONTINUE TO INDICATE CLEARING
OCCURRING TONIGHT AS ARCTIC HIGH PRESSURE BUILDS INTO THE GREAT
PLAINS STATES.
NORTH WINDS AROUND 10 KNOTS WILL BECOME NORTHWEST THIS AFTERNOON
AND WEST AROUND 5 TO 7 KNOTS LATE TONIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...TDUD
NEAR TERM...JK
SHORT TERM...TDUD
LONG TERM...JH
AVIATION...MRD
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AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1212 PM EST TUE DEC 30 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 304 AM EST TUE DEC 30 2014
IN THE NEAR TERM PERIOD...THE FOCUS WILL BE ON THE COOL DOWN AS
ARCTIC HIGH PRESSURE STRENGTHENS OVER WESTERN CANADA. MUCH COLDER
AIR WILL SPILL INTO PORTIONS OF THE CONTINENTAL U.S. AS A RESULT.
HOWEVER...NO PRECIPITATION IS EXPECTED UNTIL THE EXTENDED PERIOD
WHEN A CUT OFF LOW OVER THE DESERT SOUTHWEST MAKES ITS PROGRESSION
ACROSS THE PLAINS...AND INTO CENTRAL INDIANA. TIMING AND TRACKING
INCONSISTENCIES ARE MAKING IT DIFFICULT TO PINPOINT PRECIP TYPE AT
THIS TIME...BUT EARLY INDICATIONS ARE SHOWING MIXED PRECIPITATION
FOR MOST OF FRIDAY AND SATURDAY. PRECIP WILL END FROM WEST TO EAST
ON SUNDAY...AND THE REMAINDER OF THE EXTENDED FORECAST WILL BE DRY
AS FLOW ALOFT BECOMES MORE ZONAL ON MONDAY.
&&
.NEAR TERM /THIS AFTERNOON/...
ISSUED AT 950 AM EST TUE DEC 30 2014
FLURRIES WILL BE REMOVED FROM THE NORTHWEST. EVEN IN CLEAR AIR
MODE THE RADARS UPSTREAM DONT SHOW ANYTHING AND THE HRRR DOESNT
INTRODUCE ANYTHING.
OTHER ELEMENTS OF THE EARLIER FORECAST ARE WORKING WELL BASED ON THE
LATEST OBSERVATIONS.&&
.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
ISSUED AT 304 AM EST TUE DEC 30 2014
THE MAIN FOCUS OF THE SHORT TERM PERIOD CONTINUES TO BE ON
TEMPERATURES AND ANY CHANGES IN TIMING OF DAY 5 STORM SYSTEM
THAT COULD POSSIBLY RESULT IN PRECIP AS EARLY AS THURSDAY NIGHT.
TEMPERATURES WILL REALLY PLUMMET TONIGHT WITH COLD AIR IN PLACE
AND PARTLY CLOUDY SKIES. SOME OF THE COLDEST TEMPS IN A LONG TIME
WILL AFFECT CENTRAL INDIANA. READINGS IN THE SINGLE DIGITS OVER
THE NORTHWESTERN THIRD OF THE FORECAST AREA CAN BE EXPECTED...AND
TEENS OVER THE REMAINDER OF CENTRAL INDIANA. THERE WILL BE LITTLE
IMPROVEMENT IN TEMPS TOMORROW DESPITE SOME SUNSHINE. HIGHS ARE
ONLY EXPECTED TO WARM INTO THE 20S. AS SURFACE FLOW BECOMES
SOUTHWESTERLY ON WEDNESDAY NIGHT...TEMPS WILL BECOME SLIGHTLY MORE
MILD THOUGH FOR THE SECOND HALF OF THE SHORT TERM PERIOD WITH
HIGHS IN THE 30S ON THURSDAY...AND LOWS IN THE 20S ON THURSDAY
NIGHT.
ATTENTION THEN TURNS TO ANY PRECIP CHANCES AT THE VERY END OF THE
SHORT TERM PERIOD AS MOISTURE AHEAD OF DESERT SOUTHWEST CUT OFF
LOW MOVES CLOSER TO THE REGION. AS OF NOW...ALL MODELS ARE STILL
TRENDING TOWARD A DRY THURSDAY/THURSDAY NIGHT...AND ARE EVEN
SLOWING DOWN FURTHER WITH THE BULK OF THE PRECIP PROGGED FOR
FRIDAY AND SATURDAY ACROSS CENTRAL INDIANA.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
ISSUED AT 304 AM EST TUE DEC 30 2014
THE MAIN FOCUS OF THE SHORT TERM PERIOD CONTINUES TO BE ON
TEMPERATURES AND ANY CHANGES IN TIMING OF DAY 5 STORM SYSTEM
THAT COULD POSSIBLY RESULT IN PRECIP AS EARLY AS THURSDAY NIGHT.
TEMPERATURES WILL REALLY PLUMMET TONIGHT WITH COLD AIR IN PLACE
AND PARTLY CLOUDY SKIES. SOME OF THE COLDEST TEMPS IN A LONG TIME
WILL AFFECT CENTRAL INDIANA. READINGS IN THE SINGLE DIGITS OVER
THE NORTHWESTERN THIRD OF THE FORECAST AREA CAN BE EXPECTED...AND
TEENS OVER THE REMAINDER OF CENTRAL INDIANA. THERE WILL BE LITTLE
IMPROVEMENT IN TEMPS TOMORROW DESPITE SOME SUNSHINE. HIGHS ARE
ONLY EXPECTED TO WARM INTO THE 20S. AS SURFACE FLOW BECOMES
SOUTHWESTERLY ON WEDNESDAY NIGHT...TEMPS WILL BECOME SLIGHTLY MORE
MILD THOUGH FOR THE SECOND HALF OF THE SHORT TERM PERIOD WITH
HIGHS IN THE 30S ON THURSDAY...AND LOWS IN THE 20S ON THURSDAY
NIGHT.
ATTENTION THEN TURNS TO ANY PRECIP CHANCES AT THE VERY END OF THE
SHORT TERM PERIOD AS MOISTURE AHEAD OF DESERT SOUTHWEST CUT OFF
LOW MOVES CLOSER TO THE REGION. AS OF NOW...ALL MODELS ARE STILL
TRENDING TOWARD A DRY THURSDAY/THURSDAY NIGHT...AND ARE EVEN
SLOWING DOWN FURTHER WITH THE BULK OF THE PRECIP PROGGED FOR
FRIDAY AND SATURDAY ACROSS CENTRAL INDIANA.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
ISSUED AT 410 AM EST MON DEC 30 2014
THERE IS BETTER AGREEMENT BETWEEN THE MODELS AS THEY ALL BRING
PRECIPITATION NORTH ACROSS OUR ENTIRE REGION FRIDAY NIGHT THROUGH
SATURDAY. PREVIOUSLY THE EURO ONLY BROUGHT IT INTO OUR SOUTHERN
AREAS...WHILE MOST OTHER MODELS BROUGHT IT FARTHER NORTH. WITH THE
EXCEPTION OF THE NAM ALL MODELS HAVE TRENDED A LITTLE SLOWER IN NOT
BEGINNING PRECIPITATION UNTIL FRIDAY NIGHT. WILL GO ALONG WITH THIS
SCENARIO AND KEEP ALL BUT THE FAR SOUTH DRY UNTIL FRIDAY NIGHT.
PRECIPITATION WILL BE THE MAIN ISSUE FRIDAY NIGHT AND SATURDAY AS
MODELS PULL WARMER NORTH INTO OUR REGION. BUFKIT SOUNDINGS
INDICATE LOW CHANCES OF SNOW ACROSS OUR NORTH AND FREEZING
PRECIPITATION SOUTH EARLY FRIDAY NIGHT AND WITH THICKNESS AND
TEMPERATURES RISING SLOWLY OVERNIGHT WHICH SHOULD ALLOW CHANCES OF
FREEZING RAIN TO SPREAD NORTH BY SATURDAY MORNING AND THEN
PRECIPITATION BEING MOSTLY RAIN SATURDAY AFTERNOON. ALL MODELS
INDICATE QUITE A BIT OF PRECIPITATION AROUND SATURDAY AND WENT WITH
HPC PROGS WHICH INDICATED LIKELY POPS CENTRAL AND SOUTH SATURDAY.
AFTER LOW PRESSURE GOES BY...MODELS INDICATE A CHANGEOVER BACK TO
LIGHT SNOW OR FLURRIES SATURDAY NIGHT WITH RETURN OF COLDER AIR.
WILL ALSO MENTION SLIGHT CHANCE OF SNOW SHOWERS WITH MIXED PRECIP
FAR SOUTHEAST SUNDAY MORNING AND THEN DRY AFTER THAT AS COLD HIGH
PRESSURE BUILDS BACK IN.
MADE SOME ADJUSTMENTS TO HOURLY TEMPERATURES FRIDAY NIGHT AND
SATURDAY MORNING AS TEMPERATURES WILL BE NON-DIURNAL.
OTHERWISE...MADE ONLY MINOR TWEAKS TO A MOS BLEND ON TEMPERATURES
MOST OTHER PERIODS.
&&
.AVIATION /DISCUSSION FOR THE 301800Z TAF ISSUANCE/...
ISSUED AT 1147 AM EST TUE DEC 30 2014
MAINLY VFR CONDITIONS EXPECTED THROUGH MOST OF THE TAF PERIOD. THE
ONE CAVEAT TO THAT IS THE SPORADIC FEW/SCT MVFR CEILINGS EXISTING WITHIN
THE THIN BAND OF CLOUDS CURRENTLY EXTENDING DOWN FROM NORTH
CENTRAL INDIANA THROUGH WEST CENTRAL INDIANA. UNDERNEATH SOME OF
THE MORE CONCENTRATED CLOUD SHIELD...I.E. ABOVE AND SOUTHWEST OF
HUF AND ABOVE AND NORTH OF LAF...BKN TO OVC MVFR CEILINGS ARE
PERSISTING. EXPECT THOSE MVFR CEILINGS TO MOVE OUT OF LAF IN THE
NEXT 2 HRS OR SO AND OUT OF HUF WITHIN THE NEXT 3 TO 4 HOURS. DO
NOT CURRENTLY EXPECT TO SEE THOSE MVFR CEILINGS MAKE IT INTO IND
OR BMG. HOWEVER...IT IS NOT OUTSIDE THE REALM OF POSSIBILITY OVER
THE NEXT FEW HOURS AS CU FIELD IS THICKENING ACROSS WEST-CENTRAL AND
CENTRAL PORTIONS OF CENTRAL INDIANA. ALONG WITH THE INCREASE IN
CLOUDS...A GRADUAL BACKING OF WINDS TO THE NORTHWEST IS EXPECTED
AS WELL. WOULD NOT BE SURPRISED TO SEE AN OB OR TWO FROM LAF WITH
-SN SENSING FLURRIES WITHIN THE NEXT FEW HOURS AS WELL.
OTHERWISE...EXPECT VFR CONDITIONS WITH FEW/SCT CU AND A SCATTERED
MID-LEVEL DECK. MODEL SOUNDINGS CONTINUE TO INDICATE CLEARING
OCCURRING TONIGHT AS ARCTIC HIGH PRESSURE BUILDS INTO THE GREAT
PLAINS STATES.
NORTH WINDS AROUND 10 KNOTS WILL BECOME NORTHWEST THIS AFTERNOON
AND WEST AROUND 5 TO 7 KNOTS LATE TONIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...TDUD
NEAR TERM...JK
SHORT TERM...TDUD
LONG TERM...JH
AVIATION...MRD
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AREA FORECAST DISCUSSION
NWS MARQUETTE MI
559 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 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 559 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. LAKE EFFECT CLOUDS/SNOW WILL LIFT FAR ENOUGH
TO THE NORTH FOR IMPROVING CONDITIONS TO VFR WHICH WILL LAST INTO
WED AS WINDS BECOME WSW AT IWD. AT SAW...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 FROM 9 PM EST /8 PM CST/ THIS EVENING TO 10
AM EST /9 AM CST/ WEDNESDAY FOR MIZ002-009-010-084.
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.
WIND CHILL ADVISORY FROM 11 PM EST /10 PM CST/ THIS EVENING TO
10 AM EST /9 AM CST/ WEDNESDAY FOR MIZ004-005-011-012.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST /NOON CST/ THURSDAY
FOR LSZ240>245-248>251-263>267.
GALE WARNING FROM 1 AM WEDNESDAY TO 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 FROM 1 AM WEDNESDAY TO 1 PM EST
THURSDAY FOR LSZ246-247.
GALE WARNING FROM 1 AM EST /MIDNIGHT CST/ WEDNESDAY TO 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
NWS MARQUETTE MI
429 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 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1249 PM EST TUE DEC 30 2014
LAKE EFFECT SNOW WILL FAVOR PERSISTENT MVFR CIGS AND IFR/LIFR VSBY
AT CMX UNTIL LATE TONIGHT WHEN WINDS BACKING TO SAW WILL PUSH THE
LES BANDS OFFSHORE. GUSTY WINDS INTO WED MORNING WILL ALSO REDUCE
VSBY WITH BLSN EVEN AS THE LES REMAINS MAINLY OFFSHORE.
LAKE EFFECT CLOUDS/SNOW WILL REMAIN NEAR IWD THROUGH THIS AFTERNOON
BUT MAY LIFT FAR ENOUGH TO THE NORTH FOR IMPROVING CONDITIONS TO VFR
WHICH WILL LAST INTO WED AS WINDS BECOME WSW. AT SAW...MVFR CIGS
WITH SOME LIGHT SNOW SHOWERS OR FLURRIES WILL ALSO GIVE WAY TO
CLEARING WITH VFR CONDITIONS THIS EVENING.
&&
.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 FROM 9 PM EST /8 PM CST/ THIS EVENING TO 10
AM EST /9 AM CST/ WEDNESDAY FOR MIZ002-009-010-084.
LAKE EFFECT SNOW ADVISORY FROM 1 PM WEDNESDAY TO 1 PM EST
THURSDAY FOR MIZ001-003.
WIND CHILL ADVISORY FROM 11 PM EST /10 PM CST/ THIS EVENING TO
10 AM EST /9 AM CST/ WEDNESDAY FOR MIZ004-005-011-012.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST /NOON CST/ THURSDAY
FOR LSZ240>245-248>251-263>267.
GALE WARNING FROM 1 AM WEDNESDAY TO 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 FROM 1 AM WEDNESDAY TO 1 PM EST
THURSDAY FOR LSZ246-247.
GALE WARNING FROM 1 AM EST /MIDNIGHT CST/ WEDNESDAY TO 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...JLB
MARINE...JLA
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1233 PM CST TUE DEC 30 2014
.UPDATE...
ISSUED AT 1235 PM CST TUE DEC 30 2014
WE HAVE LET THE WIND CHILL ADVISORY EXPIRE. WIND CHILLS WILL STILL
HOVER NEAR 20 BELOW FOR MOST AREAS TODAY...SO STILL COLD. WE MAY
NEED A WIND CHILL ADVISORY ONCE AGAIN OVERNIGHT AS WINDS INCREASE
FROM THE WEST...SO WILL MONITOR THIS THREAT.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 332 AM CST TUE DEC 30 2014
COLDEST CORE OF AIRMASS IS OVER THE FCST AREA CURRENTLY. A SHORT
WAVE TROUGH MOVING SOUTHWARD NOW ALONG THE CANADIAN BORDER AND
BEHIND IT BEGINS SLOW WARMING AT THE 850 MB LEVEL LATER TODAY AND
TONIGHT. HOW MUCH WARMING WILL THERE BE AT THE SFC REMAINS A
QUESTION. TRENDED TOWARD HIGHER GUIDANCE VALUES AS GFS/NAM MOS
TEMPS TOO COLD AS MANY AREAS HAVE LIGHT OR MINIMAL SNOW COVER.
TO START THE DAY...THERE IS A BAND OF CLOUDS ALONG LEADING EDGE OF
THE SHORT WAVE...AND THIS WILL DROP SOUTHWARD THRU THE FCST
AREA..LASTING 2-3 HOURS AT ANY ONE PLACE. RAP MODEL 850 RH FIELD
SHOWS ITS PROGRESSION NICELY. BEHIND IT IT WILL CLEAR OUT AGAIN.
SO THE BALANCE OF THE DAY WILL SEE CONSIDERABLE SUN AND WINDS WILL
TURN A BIT MORE WESTERLY. WITH THIS IN MIND DID RAISE MAX TEMPS A
FEW DEGREES TO VERY NEAR YESTERDAY`S READINGS WITH ZERO TO 5 ABOVE
IN THE IMMEDIATE RRV AND SE ND/WCNTRL MN TO ZERO TO BELOW DVL
BASIN AND PARTS OF NW MN ESP AWAY FROM THICKEST FORESTS. HOURLY
TEMP AND WIND FCST INDICATE MOST AREAS OUT OF WC ADVISORY 18Z OR
SO SO WILL LEAVE THAT IN PLACE.
ALLOWED SOME FALL OFF IN TEMPS TONIGHT BUT NOT MUCH AS RISING
TEMPS EXPECTED ALONG WITH A BREEZY WEST WIND. WIND CHILLS SHOULD
BARELY DROP INTO THE ADV RANGE THIS EVENING BEFORE WARMING KICKS
IN. AREA OFFICES HOLDING OFF ON ANY NEW WIND CHILL ADV AS SO MUCH
DEPENDS ON HOW WARM IT GETS LATER TODAY AND HOW MUCH TEMP FALLS
EARLY THIS EVENING BEFORE SFC WARMING BEGINS.
SHORT WAVE WILL DIVE SOUTH THRU NW ONTARIO AND TOWARD MN ARROWHEAD
WEDNESDAY. THICKER CLOUD COVER LIKELY NORTH CENTRAL-NORTHEASTERN
MN WITH MORE OF A PARTLY CLOUDY REGIME FARTHER WEST. 850 TEMPS
DON/T FALL MUCH WEDNESDAY SO NET RESULT WILL BE WARMER AFTN HIGHS
WITH TEENS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 332 AM CST TUE DEC 30 2014
AS ADVERTISED FOR THE PAST FEW DAYS...A WEAK SHORT WAVE WILL DIVE
SOUTHEAST FROM ALBERTA AND ACROSS NORTH DAKOTA AND INTO MINNESOTA
WED NIGHT INTO THURSDAY SPREADING A BAND OF LIGHT SNOW WITH
AMOUNTS UNDER 1 INCH.
FOR FRIDAY THROUGH TUESDAY...GFS AND ECMWF HAVE COME INTO CLOSE AGREEMENT
FOR THE START OF THE PERIOD WITH A MEAN H5 TROF AXIS EXTENDING
FROM A HUDSONS BAY LOW INTO THE EASTERN GREAT LAKES WITH A REX
BLOCK ALONG THE WESTERN NOAM COAST RESULTING IN SPLIT H5 FLOW OVER
THE CONUS...A PATTERN WHICH THEN PERSISTS THROUGH THE PERIOD. THUS
WITH NORTHWEST FLOW OVER THE NORTHERN PLAINS WE STAND A GOOD
CHANCE FOR MEASURABLE SNOW /A FEW INCHES/ FROM FRIDAY EVENING
INTO SATURDAY... WITH MARKEDLY COOLER TEMPS AND ADDITIONAL
FLURRIES THROUGH THE EARLY PART OF NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1230 PM CST TUE DEC 30 2014
MOSTLY CLEAR SKIES EXPECT THIS AFTN AND TONIGHT. MAIN AVIATION ISSUE
WILL BE WINDS INCREASING OVERNIGHT...BECOMING WSW AND BREEZY
ESPECIALLY ACROSS NORTHEASTERN ND. VFR CONDITIONS EXPECTED THROUGHOUT 18Z
TAF PERIOD.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...DK
SHORT TERM...RIDDLE
LONG TERM...GUST/RIDDLE
AVIATION...SPEICHER
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
408 PM EST TUE DEC 30 2014
.SYNOPSIS...
HIGH PRESSURE AND A DRY AIRMASS WILL REMAIN IN PLACE ACROSS THE
AREA THROUGH FRIDAY. A LOW PRESSURE SYSTEM WILL LIFT NORTHEAST
ACROSS THE REGION THIS WEEKEND...BRINGING THE NEXT CHANCE FOR
PRECIPITATION.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
INCREASING LOW LEVEL LAPSE RATES ACROSS NORTHERN INDIANA
AND NORTHWEST OHIO HAVE LED TO SOME SCATTERED SNOW SHOWER/FLURRY
DEVELOPMENT THIS AFTERNOON. THIS MAY BECOME A BIT MORE WIDESPREAD
ACROSS OUR NORTHWEST OVER THE NEXT HOUR OR SO BUT WOULD EXPECT TO
SEE A DOWNTURN IN COVERAGE THROUGH THE EVENING HOURS AS THE LOW
LEVEL LAPSE RATES BEGIN TO DECREASE AGAIN. WILL THEREFORE JUST
INCLUDE A CHANCE OF A FLURRY ACROSS PARTS OF OUR NORTHWEST THROUGH
MID EVENING. THE CLOUDS ARE ALSO LOOKING FAIRLY DIURNAL ON THE
VISIBLE SATELLITE IMAGERY SO WOULD EXPECT TO SEE SOME DISSIPATION
IN THE CLOUDS THROUGH THE EVENING HOURS TOO. WILL TREND TOWARD A
PARTLY CLOUDY SKY NORTH TO MOSTLY CLEAR IN THE SOUTH FOR LATER
TONIGHT. EXPECT OVERNIGHT LOWS DOWN INTO THE TEENS ACROSS THE
AREA.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
AN ELONGATED AXIS OF SURFACE HIGH PRESSURE WILL REMAIN STRETCHED
ACROSS THE OHIO AND TENNESSEE VALLEYS WEDNESDAY INTO THURSDAY.
WITH A DRY AIRMASS IN PLACE...EXPECT MAINLY CLEAR SKIES THROUGH
MUCH OF THE SHORT TERM PERIOD. WEAK LOW LEVEL CAA WILL CONTINUE
INTO WEDNESDAY AND ALLOWING FOR MIXING UP TO ABOUT 900 MB ONLY
YIELDS HIGHS RANGING FROM THE LOWER 20S NORTH TO MID/UPPER 20S
SOUTH. LOW LEVEL FLOW WILL BEGIN TO SLOWLY BACK WEDNESDAY NIGHT
INTO THURSDAY...LEADING TO SOME WEAK DEVELOPING WAA. EXPECT HIGHS
ON THURSDAY RANGING FROM THE UPPER 20S NORTH TO LOW/MID 30S SOUTH.
THIS WILL ALSO LEAD TO A GRADUAL INCREASING IN CLOUDS FROM THE
SOUTH THROUGH THURSDAY NIGHT.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
THE CLOSED LOW IN PLACE ACROSS THE SOUTHWEST CONUS EARLIER IN THE
WEEK WILL BE MOVING ACROSS THE FOUR CORNERS REGION TOWARD THE PLAINS
ON FRIDAY. MODEL RUNS OVER THE PAST COUPLE DAYS HAVE BEEN RATHER
CONSISTENT WITH THIS MOVEMENT OF THE UPPER LOW...AS WELL AS
DEVELOPING A SOUTHERLY FLOW OUT OF THE GULF OF MEXICO AT THE SAME
TIME. MOISTURE SHOULD REMAIN LIMITED ENOUGH FRIDAY AND FRIDAY NIGHT
ACROSS THE AREA...AND CONFLUENT FLOW ALOFT WILL BE IN PLACE...SO
ONLY A SLIGHT CHANCE OF RAIN AND SNOW IS INCLUDED IN THE
FORECAST...MAINLY OVER THE SOUTHERN COUNTIES OF THE AREA.
INCONSISTENCIES ACROSS THE MODELS HAVE BEEN MUCH MORE ABUNDANT WITH
THE HANDLING OF THE UPPER LOW AS IT EMERGES INTO THE PLAINS STATES
ON SATURDAY. AFTER SUGGESTING YESTERDAY THAT PHASING OF NORTHERN AND
SOUTHERN STREAM ENERGY MAY NOT HAPPEN...RUNS LAST NIGHT AND TODAY
ARE SUGGESTING THIS PHASING MAY INDEED OCCUR. THE 12Z RUNS HAVE ALL
PRETTY MUCH COME IN SUPPORTING PHASING AND A SURFACE LOW TRACK INTO
THE OHIO VALLEY AND GREAT LAKES FROM SATURDAY AFTERNOON THROUGH
SUNDAY. THIS SOLUTION WOULD SUPPORT THE DEVELOPMENT OF A WINTRY MIX
OF PRECIPITATION LATE FRIDAY NIGHT AND SATURDAY MORNING ACROSS THE
AREA...BEFORE CHANGING OVER TO RAIN BY LATER SATURDAY AFTERNOON.
BUFKIT SOUNDINGS INDICATE ENOUGH COLD AIR SHOULD INITIALLY BE IN
PLACE AT THE SURFACE FOR SOME FREEZING RAIN TO DEVELOP LATE FRIDAY
NIGHT AND SATURDAY MORNING WITH THIS PARTICULAR STORM TRACK. ONLY A
MIX OF RAIN AND SNOW WILL BE INCLUDED IN THIS FORECAST PACKAGE FOR
NOW...PENDING MORE AGREEMENT ON THE SYSTEM TRACK FROM FUTURE MODEL
RUNS.
RAIN MAY CHANGE BACK TO SOME SNOW AS PRECIPITATION PULLS OUT OF THE
AREA SUNDAY...WITH TEMPERATURES COOLING BACK BELOW NORMAL. THE 12Z
MODELS ARE TRYING TO RESOLVE A COUPLE OF DISTURBANCES ROTATING
THROUGH CYCLONIC FLOW EARLY NEXT WEEK. THESE IMPULSES COULD BRING
CHANCES FOR LIGHT SNOW TO THE AREA MONDAY AND TUESDAY.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
VFR SKC OR JUST FEW CLOUDS THROUGH 21-00Z...AND THEN BOTH RAP AND
NAM PICK UP THE MVFR CIGS OVER INDIANA FAIRLY WELL AT THIS
TIME...SO CONTINUING WITH THE PREVIOUS FORECAST OF MVFR CIGS IN
THE 00Z-08Z TIMEFRAME...THOUGH THIS IS SLIGHTLY ON THE PESSIMISTIC
SIDE AS ADVECTION OF MOISTURE OFF LAKE MI STOPPING OVERNIGHT AS THE
SFC HIGH BUILDS IN AND THE MOISTURE FLOW CUTS OFF.
SCATTERING/LIFING OF THE MVFR CLOUDS MAY OCCUR EARLIER. SOME
POTENTIAL AT KDAY/KCMH/KLCK FOR MVFR CIGS TO DROP BELOW THE 2K FT
FUEL ALTERNATE CRITERIA THRESHOLD IN THE 02Z-08Z TIMEFRAME.
AFTER THIS LL MOISTURE PUSHES EAST...FLOW BACKS TO THE SW WITH
SLIGHTLY INCREASED WINDS.
OUTLOOK...MVFR CEILINGS AND VISIBILITIES POSSIBLE ON SATURDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...JGL
NEAR TERM...JGL
SHORT TERM...JGL
LONG TERM...SHOBE2
AVIATION...JDR
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1256 PM EST TUE DEC 30 2014
.SYNOPSIS...
HIGH PRESSURE WILL KEEP A DRY CONIDITIONS OVER THE OHIO VALLEY
THROUGH FRIDAY. ON FRIDAY NIGHT...LOW PRESSURE FROM THE SOUTHERN
PLAINS WILL TRACK TOWARD THE LOWER OHIO VALLEY AT THE SAME TIME A
LOW PRESSURE WILL TRACK TOWARD THE GREAT LAKES FROM THE NORTHERN
PLAINS. THE COMBINATION OF THESE TWO SYSTEMS WILL BRING
PRECIPITATION TO THE REGION FRIDAY NIGHT INTO THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CONTINUED SUN...BUT WITH SOME LAKE EFFECT CLOUDS TO AFFECT THE
NORTHERN FCST AREA AS THE AFTERNOON PROGRESSES. WITH THIS AMOUNT
OF SUN...TEMPS IN ESPECIALLY THE SOUTHERN FCST AREA CLIMBING A BIT
MORE THAN ANTICIPATED SO HAVE RAISED HIGHS SLIGHTLY HERE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
HIGH PRESSURE WILL DIVE SOUTHWARD FROM THE NORTHERN PLAINS TODAY
TO OKLAHOMA WEDNESDAY AND THEN SETTLE OVER THE GULF STATES
THURSDAY. THE HIGH WILL THEN LIFT NORTHWARD THROUGH THE TENNESSEE
VALLEY TO THE OHIO VALLEY BY FRIDAY EVENING. GENERALLY DRY
CONDITIONS AND MOSTLY CLEAR SKIES WILL OCCUR FOR THE REGION
THROUGH THIS TIME.
THE ARCTIC AIR WILL BE AT ITS HEIGHT OVER THE REGION TONIGHT
THROUGH WEDNESDAY NIGHT WITH LOWS IN THE TEENS AND HIGHS IN THE
20S. THE AIRMASS WILL BEGIN TO MODERATE AFTER THIS TIME WITH A
GRADUAL RISE IN BOTH DAYTIME HIGHS AND NIGHTTIME LOWS FOR EACH
PERIOD.
THE NEXT SHOT OF PRECIPITATION WILL BEGIN LATE FRIDAY NIGHT AS A
WARM FRONT PASSES OVER THE REGION ASSOCIATED WITH LOW PRESSURE
EJECTING NORTHEAST FROM THE WESTERN GULF.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
THE PERIOD BEGINS WITH SURFACE HIGH PRESSURE ACROSS THE LOWER
MISSISSIPPI VALLEY THURSDAY AND THURSDAY NIGHT. THIS FEATURE WILL
KEEP DRY CONDITIONS ACROSS THE AREA WITH BELOW NORMAL TEMPERATURES.
THE MAIN QUESTION FOR THIS FORECAST CONTINUES TO BE THE EVOLUTION OF
THE SOUTHWEST CONUS UPPER LOW. MODEL RUNS FROM THE PAST COUPLE DAYS
HAVE GENERALLY SLOWED THE EJECTION OF THIS LOW...WITH THE FEATURE
NOT REALLY LEAVING THE FOUR CORNERS ON THE 12Z RUNS UNTIL FRIDAY
NIGHT. SOME MOISTURE IS SHOWN RETURNING FRIDAY FROM THE GULF TOWARD
THE OHIO VALLEY WELL AHEAD OF THE UPPER LOW...THOUGH CONFLUENT FLOW
ALOFT SHOULD COUNTERACT THE DEVELOPMENT OF PRECIPITATION ACROSS THE
AREA. ENOUGH LIFT AND MOISTURE MAY BE IN PLACE BY FRIDAY NIGHT TO
PRODUCE SOME RAIN AND SNOW...ESPECIALLY ACROSS THE SOUTHERN PORTION
OF THE AREA. THAT CHANCE WILL CONTINUE INTO SATURDAY...THOUGH THE
12Z ECMWF/PARALLEL GFS ARE INDICATING THE BEST MOISTURE AND SURFACE
LOW DEVELOPMENT WILL REMAIN SOUTH OF THE AREA. THE 12Z GFS AND GFS
ENSEMBLE STILL SHOW THIS SYSTEM PROPAGATING TOWARD THE OHIO
VALLEY...THOUGH THE STRENGTH OF THE UPPER LOW IN PLACE OVER HUDSON
BAY MAY JUST BE ENOUGH TO BRUSH THIS SYSTEM MORE EAST ALONG THE
LINES OF THE ECMWF/PARALLEL GFS. THIS SOLUTION WOULD STILL KEEP
CHANCES OF RAIN AND SNOW ACROSS THE AREA THROUGH SUNDAY...THOUGH
MORE FOCUSED ON THE THE SOUTHERN COUNTIES.
ALL OF THE MODELS TEND TO PULL PRECIPITATION OUT OF THE AREA BY
SUNDAY NIGHT...WITH GENERALLY DRY CONDITIONS IN PLACE MONDAY.
TEMPERATURES SHOULD BE NEAR TO SOMEWHAT BELOW NORMAL AT THE END OF
THE PERIOD.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
VFR SKC OR JUST FEW CLOUDS THROUGH 21-00Z...AND THEN BOTH RAP AND
NAM PICK UP THE MVFR CIGS OVER INDIANA FAIRLY WELL AT THIS
TIME...SO CONTINUING WITH THE PREVIOUS FORECAST OF MVFR CIGS IN
THE 00Z-08Z TIMEFRAME...THOUGH THIS IS SLIGHTLY ON THE PESSIMISTIC
SIDE AS ADVECTION OF MOISTURE OFF LAKE MI STOPPING OVERNIGHT AS THE
SFC HIGH BUILDS IN AND THE MOISTURE FLOW CUTS OFF.
SCATTERING/LIFING OF THE MVFR CLOUDS MAY OCCUR EARLIER. SOME
POTENTIAL AT KDAY/KCMH/KLCK FOR MVFR CIGS TO DROP BELOW THE 2K FT
FUEL ALTERNATE CRITERIA THRESHOLD IN THE 02Z-08Z TIMEFRAME.
AFTER THIS LL MOISTURE PUSHES EAST...FLOW BACKS TO THE SW WITH
SLIGHTLY INCREASED WINDS.
OUTLOOK...MVFR CEILINGS AND VISIBILITIES POSSIBLE ON SATURDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...JDR
NEAR TERM...JDR
SHORT TERM...FRANKS
LONG TERM...SHOBE2
AVIATION...JDR
AREA FORECAST DISCUSSION
NWS EL PASO TX/SANTA TERESA NM
258 PM MST TUE DEC 30 2014
.SYNOPSIS...
A COLD FRONT PUSHED WEST ACROSS MUCH OF THE BORDERLAND TODAY...
LEAVING IN IT`S WAKE COLD AIR AND INCREASING LOW CLOUDS FOR TONIGHT.
A PACIFIC FRONTAL SYSTEM WILL MOVE TO WESTERN ARIZONA WEDNESDAY.
THIS WILL PUSH CLOUDS IN AND KICK OFF SNOW SHOWERS OVER THE GILA AND
RAIN SHOWERS OVER THE LOWLANDS. MOST OF THIS ACTIVITY WILL END
THURSDAY FOR A BRIEF PERIOD BEFORE THE MAIN UPPER LOW MOVES OVER THE
AREA FRIDAY. THIS WILL SPREAD MORE RAIN AND SNOW SHOWERS...WITH THE
SACRAMENTO MOUNTAINS LIKELY SEEING HEAVY SNOW. MUCH OF THE LOWLANDS
COULD SEE A MIX OF RAIN AND SNOW BUT LITTLE OR NO ACCUMULATION. THE
LOW EXITS THE AREA FRIDAY NIGHT ALLOWING SKIES TO CLEAR. THROUGH MID
WEEK OF NEXT WEEK...THE PATTERN LOOKS TO REMAIN A DRY WITH
TEMPERATURES POSSIBLY BACK ABOVE NORMAL BY MONDAY.
&&
.DISCUSSION...
COMPLEX WINTER WEATHER PATTERN TO CONTINUE OVER THE NEXT 3 DAYS.
MODELS HAVE BEEN RELATIVELY CLOSE...BUT 12Z GFS RUN THROUGH SOME
DOUBT INTO FRIDAY SOLUTION. OTHERWISE FEW CHANGES MADE TO PREVIOUS
FORECAST PACKAGE.
BACK DOOR COLD FRONT SWEPT THROUGH THE RIO GRANDE VALLEY THIS
MORNING. SFC OBS SHOW FRONT MAYBE OUT TO THE ARIZONA BORDER. COOL
AIR LIKELY SHALLOW FROM DEMING WEST AS THOSE LOCATIONS WERE STILL
ABLE TO MODIFY THIS AFTERNOON. EXTENSIVE LOW CLOUDS HAVE BEEN DAMMED
UP AGAINST EASTERN TERRAIN ALL DAY. CLOUDS COVERED THE EASTERN SACS
AND ARE SLOWLY SEEPING INTO HUDSPETH COUNTY. SOME FREEZING FOG HAS
BEEN REPORTED...BUT PROG SOUNDINGS SUPPORT VERY LITTLE IN THE WAY OF
PRECIP OVERNIGHT. WILL KEEP FREEZING FOG ADV OUT FOR EASTERN SACS
AND ALSO ADD HUDSPETH COUNTY TO THE ADVISORY. TYPICAL PATTERN IS FOR
LOW CLOUDS TO ACCELERATE WESTWARD AFTER SUNSET. HRRR ALSO SHOWS
THIS...CLOUDING EL PASO CO OVER AROUND 6-7 PM...AND MOST OF THE REST
OF THE LOWLANDS TO THE DIVIDE BY AROUND MIDNIGHT.
LOW CLOUDS AND EAST PUSH WILL SLOWLY DIMINISH WEDNESDAY AS MAIN
UPPER LOW DESCENDS DOWN TO WESTERN ARIZONA AND SURFACE GRADIENT
BEGINS TO RELAX. NOT EXPECTING MUCH OF ANY PRECIP WEDNESDAY THOUGH
KEEPING LOW POPS IN SEEMS PRUDENT. PACIFIC UPPER LOW AND SURFACE
FRONT CONTINUE ADVANCING EAST. UPPER LOW PROGGED OVER EASTERN
ARIZONA THURSDAY MORNING...WITH ATTENDANT FRONT PUSHING EAST ACROSS
THE CWA. THIS WILL PRODUCE ANOTHER PERIOD SHOWERS...WITH SNOW LEVELS
MOSTLY ABOVE 5000 FT. WILL ISSUED WINTER WEATHER ADV FOR THE GILA
ZONES AS THIS SYSTEM LIKELY TO DROP DECENT SNOWFALL OVER THAT AREA.
SHOULD SEE BRIEF END TO PRECIP THURSDAY NIGHT AS UPPER LOW LIFTS
INTO COLORADO AND FRONT IS EAST OF THE AREA.
HANG BACK LOW FORMS SOUTHWEST OF ORIGINAL LOW AND WILL MOVE OVER
SOUTHERN NEW MEXICO FRIDAY. THIS IS WHERE THE 12Z GFS RUN DEVIATES
FROM THE OTHER MODELS. NAM/ECMWF STILL SHOWING STRONG PRESENCE OF
THIS LOW WITH HEAVY SNOW OVER THE SACS AND RAIN/SNOW OVER THE
LOWLANDS. WILL STILL KEEP THIS THINKING FOR NOW. SNOW LEVELS FRIDAY
LIKELY AT 4500-5000 FT SO SOME OF THE LOWLANDS COULD GET LIGHT SNOW
ACCUMULATIONS. MOST FAVORED AREA NORTH AND WEST OF LAS CRUCES WILL
HAVE TO BE WATCHED FOR POTENTIAL ADVISORIES. BELIEVE THE SACS WILL
GET HEAVY SNOW BUT TOO EARLY TO ISSUE AT THIS TIME...ESPECIALLY WITH
THE GFS UNCERTAINTY.
UPPER LOW EXITS FRIDAY NIGHT WITH CLEARING TO FOLLOW. SATURDAY
THROUGH TUESDAY PERIOD SHOULD REMAIN DRY AS WEST COAST UPPER RIDGE
PERSISTS. TEMPERATURES SHOULD SLOWLY WARM BACK TO NORMAL BY MONDAY
AND TUESDAY.
&&
.AVIATION...VALID 31/00Z-01/00Z...
THRU 06Z...P6SM FEW-SCT020 SCT-BKN150-200. AFT 06Z MOISTURE WILL BE
PUSHING WESTWARD WITH SCT-BKN010-020 BKN-OVC120-150 DEVELOPING AT
ALL TAF SITES WITH VERY PATCHY FZDZ POSSIBLE...MAINLY EAST OF KELP
AND POSSIBLY TOWARD KTCS. LOW CLOUDS WILL REMAIN IN PLACE EAST OF
RIO GRANDE...BUT POSSIBLY BECOME MORE SCT AFT 18Z WEST OF RIVER. E
TO NE WINDS 10-20G30KTS THRU PD...STRONGEST ON WESTERN MOUNTAIN
SLOPES.
&&
.FIRE WEATHER...
COLD FRONT HAS MOVED THROUGH THE REGION WITH GUSTY EAST WINDS IN
PLACE WHICH WILL CONTINUE THROUGH WEDNESDAY. VERY LIGHT
PRECIPITATION IN THE FORM OF FREEZING DRIZZLE IS POSSIBLE FAR NORTH
AND EAST TONIGHT...BUT DEEPER LOW LEVEL MOISTURE WILL BE PUSHING
WEST THROUGH THE NIGHT. SNOW IS EXPECTED OVER THE GILA REGION
STARTING WEDNESDAY NIGHT AND OVER THE SACS MAINLY LATE THURSDAY INTO
FRIDAY. SEVERAL INCHES OF SNOW ARE POSSIBLE IN EACH OF THESE
MOUNTAIN ZONES. LOWLANDS COULD SEE A MIX OF RAIN AND SNOW WITH ANY
ACCUMULATIONS REMAINING UNDER AN INCH. EXPECT BELOW NORMAL
TEMPERATURES TO REMAIN IN PLACE THROUGH THE WEEKEND BEFORE WARMER
AIR RETURNS EARLY NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
EL PASO 29 43 35 50 31 / 0 0 10 20 20
SIERRA BLANCA 24 36 29 46 30 / 20 20 10 20 20
LAS CRUCES 26 42 31 46 30 / 0 0 10 30 30
ALAMOGORDO 25 42 31 48 29 / 20 0 20 20 30
CLOUDCROFT 20 33 22 36 23 / 30 20 20 40 50
TRUTH OR CONSEQUENCES 25 42 30 42 26 / 10 20 30 30 30
SILVER CITY 25 41 28 37 25 / 0 10 50 50 30
DEMING 27 44 30 44 27 / 0 0 20 30 30
LORDSBURG 28 45 31 43 26 / 0 10 40 40 20
WEST EL PASO METRO 30 43 36 48 35 / 0 0 10 20 20
DELL CITY 22 33 28 45 25 / 20 20 20 20 20
FORT HANCOCK 26 41 33 51 29 / 10 10 10 10 20
LOMA LINDA 24 38 29 45 32 / 20 10 10 20 30
FABENS 27 42 34 49 29 / 0 0 10 20 20
SANTA TERESA 26 44 32 48 30 / 0 0 10 20 20
WHITE SANDS HQ 27 40 33 46 32 / 0 0 10 20 30
JORNADA RANGE 21 43 25 45 25 / 0 0 10 30 30
HATCH 25 44 30 46 28 / 0 10 20 30 30
COLUMBUS 30 45 34 45 32 / 0 0 10 30 20
OROGRANDE 25 40 30 46 30 / 10 0 10 20 30
MAYHILL 18 30 22 38 26 / 50 30 30 40 30
MESCALERO 18 34 22 40 24 / 30 20 20 40 50
TIMBERON 20 33 22 38 25 / 20 20 20 40 40
WINSTON 22 39 24 39 21 / 20 20 50 60 30
HILLSBORO 25 42 28 41 26 / 10 20 30 40 30
SPACEPORT 21 44 25 45 24 / 0 10 20 30 30
LAKE ROBERTS 24 42 25 37 24 / 0 20 60 70 30
HURLEY 25 42 28 40 26 / 0 10 40 40 20
CLIFF 22 47 31 40 20 / 0 10 70 60 20
MULE CREEK 19 46 24 38 17 / 0 10 80 70 30
FAYWOOD 27 41 30 40 28 / 0 10 30 40 30
ANIMAS 30 50 34 47 28 / 0 0 40 30 20
HACHITA 26 46 29 45 26 / 0 0 30 30 20
ANTELOPE WELLS 29 53 33 50 28 / 0 0 20 30 20
CLOVERDALE 32 55 34 46 27 / 0 0 40 40 30
&&
.EPZ WATCHES/WARNINGS/ADVISORIES...
NM...FREEZING FOG ADVISORY FROM 7 PM THIS EVENING TO 11 AM MST
WEDNESDAY FOR NMZ417.
WINTER WEATHER ADVISORY FROM 6 PM WEDNESDAY TO 11 AM MST
THURSDAY FOR NMZ401>403-408.
WIND ADVISORY UNTIL 11 AM MST WEDNESDAY FOR NMZ411.
FREEZING FOG ADVISORY UNTIL 11 AM MST WEDNESDAY FOR NMZ416.
TX...FREEZING FOG ADVISORY FROM 7 PM THIS EVENING TO 11 AM MST
WEDNESDAY FOR TXZ420>424.
WIND ADVISORY UNTIL 11 AM MST WEDNESDAY FOR TXZ418.
&&
$$
HEFNER/GRZYWACZ
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1216 PM CST TUE DEC 30 2014
.UPDATE...
COLDER AND SOMEWHAT DRIER AIR BEHIND THE ARCTIC COLD FRONT THAT
PASSED ABOUT MID MORNING. WINDS ALSO SLIGHTLY MORE NORTHERLY.
PRECIPITATION REMAINS LIGHT BUT ENOUGH FOR A LIGHT GLAZE ALMOST
EVERYWHERE...AND LATELY OVER SOUTHERN PART OF THE ROLLING PLAINS.
WIND CHILLS HAVE REMAINED BELOW MINUS 5 ACROSS NORTHWEST ZONES
WITH WINDS ONLY SLIGHTLY LOWER WHILE TEMPERATURES UNLIKELY TO RISE
THIS AFTERNOON. WE HAVE ADDED THE SOUTHERN PART OF THE ROLLING
PLAINS TO THE WINTER WEATHER ADVISORY NOW UNTIL 3 PM. ALSO ISSUED
A WIND CHILL ADVISORY FOR THE NORTHWEST UNTIL 3. MOST SOLUTIONS
CONTINUE TO GENERATE LIGHT PRECIPITATION TONIGHT PERHAPS SLIGHTLY
FAVORING SOUTHEAST ZONES BUT NOT CLEAR YET. RMCQUEEN
&&
.AVIATION...
WITH DRIER COLDER AIR MOVING IN WE EXPECT CEILINGS TO INCH BACK TO
NEAR LOWER END OF MVFR CEILINGS LATER TODAY. SOLUTIONS STILL SUGGEST
LOWERING CONDITIONS MAY BECOME PERVASIVE OVERNIGHT WITH EXPANDING
LIGHT PRECIPITATION FOR KLBB AND KPVW BUT NOT CERTAIN ENOUGH
EITHER FOR A CHANGE OR TEMPO GROUP. RMCQUEEN
&&
.PREV DISCUSSION... /ISSUED 921 AM CST TUE DEC 30 2014/
UPDATE...
ISSUED A WINTER WEATHER ADVISORY FOR FREEZING DRIZZLE ON THE
CAPROCK UNTIL NOON. MAY NEED TO EXTEND THIS AFTERNOON...AND IF SO
WILL CONSIDER GOING THROUGH MUCH OF THE NIGHT. VERY COLD AIR
MOVING SOUTHWARD SHOULD CHANGE FREEZING DRIZZLE MORE TO LIGHT SNOW
AND PERHAPS LESS ICE ACCUMULATIONS BUT NOT CERTAIN AT THIS TIME. RMCQUEEN
PREV DISCUSSION... /ISSUED 544 AM CST TUE DEC 30 2014/
UPDATE...
KLBB 88D SHOWING THE EXPANSION OF VERY LIGHT REFLECTIVTY /ZERO TO
MINUS 15 DBZ/ BTWN 1000 AND 5000 FT AGL AND LOWERING WITH TIME.
THIS SHOULD BE THE PERIOD OF VERY LIGHT FLURRIES AND/OR FREEZING
DRIZZLE ASSOCIATED WITH FRONTOGENTICAL FORCING. PER THE HRRR THIS
PRECIP SHOULD SHIFT SWD WITH THE FORCING THROUGH THE MORNING.
EXPECTATION IS IT SHOULD REMAIN TOO LIGHT CAUSE MUCH IN THE WAY OF
DIFFICULTY THIS MORNING...BUT WILL CONTINUE TO MONITOR TRENDS.
AVIATION...
CIGS TO LOWER A BIT MORE DURING THE FIRST PART OF THE FCST PERIOD
BUT SHOULD REMAIN MVFR THEN REMAIN PRETTY STABLE THROUGH THE
REMAINDER OF THE PERIOD. ANTICIPATE SOME PERIODS OF LIGHT FREEZING
DRIZZLE AND/OR FLURRIES THROUGH THE FCST TIME AS WELL. GUSTY NNE
WINDS THROUGH MUCH OF THE DAY SHOULD RELAX TOWARD EVENING.
PREV DISCUSSION... /ISSUED 428 AM CST TUE DEC 30 2014/
SHORT TERM...
THE COLD FRONT IS NOW WELL INTO THE PERMIAN BASIN AND BIG COUNTRY
WITH MUCH COLDER AIR FILTERING IN BEHIND IT RATHER THAN SURGING AT
THIS POINT. WITH A GOOD STRATUS DECK NOW IN PLACE...ALTHOUGH
NOT TERRIBLY LOW AT ABOUT 2000 FT AGL...AND LOW LEVEL COLD ADVECTION
PERSISTING THROUGH THE DAY...TEMPS WILL HAVE TROUBLE MOVING OFF OF
MORNING LOWS. INDEED...WILL LIKELY SEE TEMPS FALL THROUGH ABOUT
MID-MORNING BEFORE SOME SLIGHT RECOVERY LATER IN THE DAY.
HOWEVER...MAIN FOCUS CONTINUES TO BE ON CHANCE FOR VERY LIGHT
PRECIPITATION TODAY AND TONIGHT AND POTENTIAL IMPACTS OF IT WITH
TEMPS IN THE TEENS AND 20S. THIS PRECIP EVENT CONTINUES TO LOOK
PRIMARILY ISENTROPIC DRIVEN WITH SOME MINOR CONTRIBUTION FROM
FRONTOGENETICAL FORCING EARLY ON. ISENTROPIC PROJECTIONS DEPICT LIFT
INITIALLY AT THE VERY TOP OF THE COLD AIR...PRIMARILY IN THE WARMER
AND DRIER MID LEVELS ABOVE IT. HOWEVER...AS THE COLD AIR DEEPENS
THROUGH THE DAY...SOME OF THIS COLD MOISTURE SHOULD BE TAPPED BY THE
ISENTROPIC LIFT TO PRODUCE SOME LIGHT PRECIP. BEST WINDOW FOR THIS
APPEARS TO BE BETWEEN 3 PM AND MIDNIGHT...AFTER WHICH ISENTROPIC
LIFT WEAKENS SIGNIFICANTLY. QUESTION THEN BECOMES PHASE OF THIS
PRECIPITATION. PROGGED SOUNDINGS SUPPORT EITHER FREEZING DRIZZLE OR
VERY LIGHT SNOW. COLDER LOW LEVELS ACROSS THE NORTH AND WEST MIGHT
END UP FAVORING FLURRIES TO A DUSTING OF SNOW WHILE FURTHER SOUTH
AND EAST FREEZING DRIZZLE LIKELY TO BE PREDOMINANT. HOW MUCH IS A
BIG QUESTION WITH SOUNDINGS SUGGESTING THE MODEL QPF OUTPUT IS
OVERDONE.
AS FOR POTENTIAL FOR ADVISORY...STILL SOME DETAILS TO WORK OUT SUCH
AS FLURRIES VS DRIZZLE AND TIMING OF ONSET OF PRECIP HEAVY AND/OR
WIDESPREAD ENOUGH TO BEGIN TO CAUSE TRAVEL ISSUES. SINCE CURRENT
EXPECTATION IS THE MORE SIGNIFICANT PART OF THE EVENT IS STILL 8-12
HOURS AWAY AND ANOTHER MODEL RUN AND 12Z UA ANALYSIS SHOULD HELP
NARROW DOWN THE DETAILS FURTHER...WILL DEFER ON THE ISSUANCE OF AN
ADVISORY ATTM.
LONG TERM...
AN UA DISTURBANCE ACROSS THE GREAT BASIN IS STILL PROGGED TO PINCH
OFF AND DIVE SSE TO ACROSS SRN CALI TOMORROW...AND ACROSS THE DESERT
SW ON THURSDAY. AS SUCH...FLOW ALOFT WILL EVOLVE FROM A BROAD
CYCLONIC FLOW TO SWRLY FLOW. IF THE ANTICIPATED TRACK OF THE SYSTEM
DOES NOT CHANGE...IT WILL MOVE DIRECTLY ACROSS THE SOUTHERN PLAINS
FRIDAY NIGHT THEN EXIT TO THE NE BY SATURDAY. THEREAFTER...DRY NW
FLOW ALOFT WILL PREVAIL.
TEMPS STRUGGLING TO GET OUT OF THE 20S WILL CHARACTERIZE WEDNESDAY
AS THE CAA USHERED IN BY LAST NIGHT/S COLD FRONTAL PASSAGE REMAINS
ENTRENCHED. FURTHERMORE...MAY ALSO EXPERIENCE A LINGERING FREEZING
DRIZZLE/WINTRY MIX...COURTESY OF MOISTENED ATMOSPHERIC LOW LEVELS
AND AN UPSLOPE SFC REGIME. THIS WINTRY MIX MAY BE HARD-PRESSED TO
REACH THE GROUND AS IT WILL HAVE TO FALL THROUGH RATHER DRY
MID-LEVELS...WHICH IS WHERE THE SLIVER OF UL SUPPORT IS MAXIMIZED.
ON THURSDAY DURING THE DAY...A SIMILAR SCENARIO TO WEDNESDAY WILL
PLAY OUT...WITH THE DIFFERENCE BEING PROGGED MODEL SOUNDINGS HINTING
AT A WARM TONGUE DEVELOPING IN THE MID-LEVELS...THUS SUGGESTING
MORE OF A FREEZING RAIN/WINTRY MIX OCCURRENCE. NONETHELESS...THE
BEST LIFT IS STILL MAXIMIZED WITHIN THE DRY MID-LEVELS AND HENCE LIGHT
PRECIP IS EXPECTED. BY THURSDAY NIGHT HOWEVER...MID-LEVELS ARE
SHOWN TO MOISTEN AS THE UA SYSTEM DRAWS NEAR. THE BEST UL SUPPORT
IS FINALLY TAPPING INTO ADEQUATE MOISTURE. MID-LEVEL MOISTENING
OCCURRING WITHIN THE DENDRITIC ZONE COULD PROMOTE A CHANCE OF
SNOW...PARTICULARLY ACROSS THE HIGHER TERRAIN OF THE NWRN ZONES.
ELSEWHERE...FREEZING RAIN AND PERHAPS SLEET WILL BE COMMON...WITH
THE EXCEPTION OF THE FAR ROLLING PLAINS WHERE A MIX OF A COLD RAIN
AND FREEZING RAIN MAY OCCUR...GIVEN TEMPS WILL WARM TO SLIGHTLY
ABOVE FREEZING THERE /LOWER 30S ELSEWHERE/. TEMPS WILL WARMUP
FURTHER ON FRIDAY...INTO THE MIDDLE TO UPPER 30S ON THE CAPROCK
TO UPPER 30S TO LOWER 40S OFF THE CAPROCK...WHICH WILL AFFECT THE
PRECIP PHASE. COULD THEREFORE SEE MORE OF A RAIN AND SNOW MIX OR A
RAIN AND FREEZING RAIN MIX DEVELOP BY THE EVENING /THE NWRN ZONES
WILL BE THE EXCEPTION AS SOUNDING PROFILES SUGGEST LIGHT SNOW
THERE/.
LATE FRIDAY NIGHT-EARLY SATURDAY MORNING...LARGE SCALE ASCENT WILL
BE FLEETING AS THE SYSTEM COMMENCE TO EXIT THE REGION. PERHAPS SOME
LINGERING RAIN AND SNOW MIX WILL BE POSSIBLE ACROSS PORTIONS OF THE
ROLLING PLAINS EARLY SATURDAY MORNING. THEREAFTER...DRY NW FLOW
ALOFT WILL PREVAIL AND THE RETURN TO SRLY SFC FLOW EARLY NEXT
WEEK WILL AID IN PUSHING TEMPS BACK UP TO NEAR 50.
NOTE: ALTHOUGH THE WINTRY PRECIP IS EXPECTED TO BE LIGHT THIS
WEEK...IT COULD STILL POSE A THREAT FOR HAZARDOUS ROAD
CONDITIONS AS A THIN GLAZE OF ICE COULD FORM ACROSS OVERPASSES AND
BRIDGES IN PARTICULAR. AS YOU HEAD OUT TO ENJOY THE NEW YEAR
FESTIVITIES...CAUTION IS ADVISED. CHECK BACK TO STAY ALERT AND UP TO
DATE WITH ANY WEATHER CHANGES.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 7 22 17 32 20 / 40 20 10 20 20
TULIA 10 22 19 32 23 / 40 10 10 20 20
PLAINVIEW 12 23 19 32 25 / 40 10 10 20 20
LEVELLAND 14 24 19 32 25 / 50 20 20 20 30
LUBBOCK 14 25 21 32 26 / 50 20 20 20 30
DENVER CITY 16 25 20 33 26 / 50 20 20 30 30
BROWNFIELD 15 25 20 33 26 / 50 20 20 30 30
CHILDRESS 14 25 22 34 26 / 40 10 10 20 30
SPUR 15 25 22 33 27 / 50 20 20 30 30
ASPERMONT 18 27 24 36 29 / 40 20 20 30 30
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR THE
FOLLOWING ZONES: TXZ021>024-027>030-033>037-039>044.
WIND CHILL ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR THE
FOLLOWING ZONES: TXZ021>023.
&&
$$
05/99/05
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1006 AM CST TUE DEC 30 2014
.UPDATE...
WITH FOG BEGINNING TO LIFT IN MANY AREAS EAST OF THE I35
CORRIDOR...ALLOWED THE DENSE FOG ADVISORY TO EXPIRE OUT THERE.
HOWEVER...FOG IS SLUGGISH TO LIFT ON THE ESCARPMENT AND SOME
LOCATIONS IN THE EASTERN PARTS OF THE I35 CORRIDOR COUNTIES ARE
STILL SEEING VISIBILITIES RISE AND FALL. EXPECT THIS TO IMPROVE
OVER THE NEXT TWO HOURS SO EXTENDED THE DFA THROUGH 18Z TO BE
SAFE.
TB3
&&
.PREV DISCUSSION... /ISSUED 725 AM CST TUE DEC 30 2014/
UPDATE...ONE FINAL UPDATE TO EXPAND DENSE FOG ADVISORY WEST TO
THE RIO GRANDE.
PREV DISCUSSION... /ISSUED 613 AM CST TUE DEC 30 2014/
AVIATION...
LIFR/VLIFR VIS AND CIGS IN AUSTIN AND SAN ANTONIO THIS MORNING
WILL CONTINUE UNTIL MID-MORNING WHEN NORTHWESTERLY WINDS PICK UP.
THEN MVFR/IFR CIGS THROUGH THE REST OF THE TAF PERIOD. DRT WILL
DROP TO IFR SHORTLY AND STAY THAT WAY UNTIL AROUND 18Z. EXPECTING
PRECIPITATION WEDNESDAY MORNING AT DRT. HAVE NOT INCLUDED ANY
PRECIP IN AUSTIN OR SAN ANTONIO...BUT THERE IS A SLIGHT CHANCE FOR
RAIN. IF THERE IS ANY RAIN IT WILL DROP VIS TO MVFR.
PREV DISCUSSION... /ISSUED 523 AM CST TUE DEC 30 2014/
UPDATE...SECOND UPDATE TO EXPAND DENSE FOG ADVISORY FARTHER WEST
AND SOUTH BASED ON SATELLITE AND WEB CAM TRENDS. THIS ALSO LINES
UP WELL WITH HRRR EXPANSION OF FOG.
PREV DISCUSSION... /ISSUED 443 AM CST TUE DEC 30 2014/
UPDATE...QUICK UPDATE TO ISSUE DENSE FOG ADVISORY FOR I-35
CORRIDOR FROM COMAL TO WILLIAMSON COUNTY EASTWARD. THIS IS BASED ON
SEVERAL WEBCAMS AND OBS INDICATING DENSE FOG. THERE IS ALSO THE
POTENTIAL FOR PATCHY TO AREAS OF DENSE FOG SOUTH AND WEST OF THE
ADVISORY AREA THROUGH THE MORNING.
PREV DISCUSSION... /ISSUED 401 AM CST TUE DEC 30 2014/
SHORT TERM (TODAY THROUGH WEDNESDAY)...AREAS OF LOW STRATUS AND
FOG HAVE FORMED ACROSS EASTERN AREAS AS WELL AS ALONG THE RIO
GRANDE EARLY THIS MORNING. THE FOG AND CLOUDS WILL CONTINUE TO
EXPAND INTO THE I-35 CORRIDOR AND PORTIONS OF THE HILL COUNTRY
THROUGH THE MORNING HOURS.
THE MUCH ADVERTISED ARCTIC AIRMASS HAS MOVED THROUGH THE HILL
COUNTRY AND INTO WEST TEXAS. THE AIRMASS IN RELATIVELY DENSE
BEHIND A 1055MB HIGH ANALYZED UP IN MONTANA. THE AIRMASS WILL
GRADUALLY FILTER INTO SOUTH-CENTRAL TEXAS TODAY AND TONIGHT.
ISENTROPIC ASCENT ABOVE THE SHALLOW...COLD AIRMASS WELL DEVELOP
TONIGHT AND GRADUALLY STRENGTHEN WEDNESDAY AND WEDNESDAY NIGHT.
INITIALLY THICK CLOUDS WILL RESULT FROM THIS...WITH ONLY PATCHY
DRIZZLE AND PATCHY LIGHT RAIN DEVELOPING ACROSS THE WESTERN CWA
TONIGHT AND EXPANDING EAST ON WEDNESDAY. THE GFS CONTINUES TO BE
DRIER IN THE LOWEST LEVELS TODAY THROUGH WEDNESDAY...TAKING LONGER
TO MOISTEN. HOWEVER FORECAST SOUNDINGS FROM THE HRRR/ARW/NMM AS
WELL AS NAM12 ARE NOT QUITE AS AGGRESSIVE WITH THIS DRY LAYER AND
MOISTENS FASTER. HAVE FOLLOWED SLIGHTLY CLOSER TO THE LATTER. THIS
COULD POTENTIALLY RESULT IN PATCHY FREEZING DRIZZLE AND FREEZING
LIGHT RAIN ALONG AND NORTH OF A PANDALE TO LEAKY TO JOHNSON CITY
TO BURNET LINE EARLY WEDNESDAY MORNING. QPF AMOUNTS SHOULD BE VERY
LIGHT...AND GIVEN GROUND TEMPS AND PATCHY COVERAGE IMPACTS SHOULD
BE LIMITED TO ELEVATED SURFACES WITH MINIMAL TRAVEL IMPACTS.
ON WEDNESDAY VERY LITTLE DIURNAL TEMPERATURE RANGE IS EXPECTED...
WITH HIGHS ONLY CLIMBING INTO THE MID 30S ACROSS THE HILL COUNTRY
(WITH A FEW ISOLATED HILL COUNTRY SPOTS REMAINING IN THE LOW
30S)...UPPER 30S ALONG THE I-35 CORRIDOR AND LOW 40S ALONG THE RIO
GRANDE AS WELL AS FAR SOUTHERN/SOUTHEAST AREAS.
LONG TERM (WEDNESDAY NIGHT THROUGH MONDAY)...
FREEZING RAIN WITH TRAVEL IMPACTS POSSIBLE LATE NEW YEARS EVE
INTO NEW YEARS DAY ACROSS THE HILL COUNTRY. WINTER STORM WATCH POSTED...
THE UPPER LEVEL LOW ACROSS SOUTHERN CALIFORNIA IS FORECAST TO
MOVE EAST INTO ARIZONA NEW YEARS EVE NIGHT INTO NEW YEARS DAY. THE
ISENTROPIC UPGLIDE OVER THE COLD AIRMASS STRENGTHENS WEST TO EAST
DURING THIS TIME. SEVERAL MODELS HAVE BEEN INDICATING FOR A FEW
RUNS NOW A MID AND UPPER LEVEL SHORTWAVE IN THE SOUTHWEST FLOW
ALOFT MOVING OUT OF MEXICO AND INTO WEST-CENTRAL TEXAS AND THE
HILL COUNTRY LATE WEDNESDAY NIGHT AND THURSDAY. GFS AND ECMWF BOTH
SHOW ENHANCED BAND OF QPF CLIPPING THE HILL COUNTRY...ALONG WITH
SREF OUTPUT. CONFIDENCE CONTINUES TO GROW IN FREEZING RAIN EVENT
LATE WEDNESDAY NIGHT THROUGH MIDDAY THURSDAY ACROSS AT LEAST THE
HILL COUNTRY. THE WARM CLOUD LAYER DEPTH IS INCREASING DURING THIS
TIME...BUT CAN NOT COMPLETELY RULE OUT SLEET MIXING IN ACROSS THE
NORTHERN HILL COUNTRY AS WELL. GIVEN HOLIDAY TRAVEL SENSITIVITY...
AND AFTER COORDINATION WITH SURROUNDING WFOS...WE HAVE DECIDED TO
ISSUE A WINTER STORM WATCH FOR THE HILL COUNTRY...ALONG AND NORTH
OF A VAL VERDE TO BANDERA TO BURNET COUNTY LINE. IF TEMPS AND
ENHANCEMENT IN QPF VERIFY...THERE COULD BE A BAND ACROSS THE
NORTHERN HILL COUNTRY OF HIGHER ICE ACCUMULATION AMOUNTS.
FARTHER EAST ALONG THE I-35 CORRIDOR...TEMPERATURES WILL BE VERY
CLOSE TO FREEZING EARLY THURSDAY MORNING. ALTHOUGH THESE COUNTIES
ARE NOT CURRENTLY IN THE WATCH...THE FREEZING RAIN LINE IS
FORECAST TO REACH A HELOTES TO WIMBERLEY TO GEORGETOWN LINE. ANY
TRENDS DOWNWARD IN THE TEMP FORECAST...OR WET-BULB COOLING...COULD
PUSH THIS LINE TOWARDS THE AUSTIN AND NORTHERN SAN ANTONIO METRO
AREAS. THOSE WITH TRAVEL PLANS NEW YEARS EVE NIGHT INTO NEW YEARS
DAY ALONG THE INTERSTATE 35 CORRIDOR SHOULD CLOSELY MONITOR FOR
ANY FORECASTS UPDATES.
MODELS ARE SLIGHTLY SLOWER WITH HOW FAST THE UPPER LEVEL LOW
EJECTS OUT INTO THE PLAINS FROM RUNS A FEW DAYS AGO. THE UPPER
LEVEL LOW MOVES ACROSS SOUTHERN NEW MEXICO FRIDAY AND NORTHEAST
THROUGH WEST TEXAS FRIDAY NIGHT INTO SATURDAY MORNING. GOOD
CHANCES FOR RAIN WILL CONTINUE ACROSS THE REGION THURSDAY NIGHT
THROUGH FRIDAY NIGHT. THE WARM CLOUD LAYER CONTINUES TO WARM
FURTHER WITH SLIGHT MODIFICATION IN THE COLD AIRMASS BELOW. PRECIP
WILL REMAIN ALL LIQUID DURING THIS TIME (ALTHOUGH MAY HAVE TO
WATCH CLOSELY ACROSS FAR NORTHERN AREAS OF THE CWA THURSDAY
NIGHT). IN ADDITION...THERE WILL ALSO BE THE POTENTIAL FOR
EMBEDDED THUNDER THURSDAY NIGHT THROUGH FRIDAY NIGHT AS ELEVATED
LAPSE RATES STEEPEN...AND HAVE CONTINUED THIS IN THE FORECAST.
CLEARING AND DRYING TAKES PLACE DOES EVENTUALLY TAKE PLACE
WEST TO EAST SATURDAY WITH HIGHS TEMPS WARMING BACK TO TOWARDS
SEASONABLE LEVELS OVER THE WEEKEND AND INTO EARLY NEXT WEEK.
JR
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 52 34 38 34 40 / 10 10 20 30 60
AUSTIN BERGSTROM INTL AIRPORT 52 35 38 34 40 / 10 10 20 30 60
NEW BRAUNFELS MUNI AIRPORT 54 36 38 34 39 / 10 10 20 30 50
BURNET MUNI AIRPORT 48 30 36 29 37 / 10 10 20 30 60
DEL RIO INTL AIRPORT 54 36 41 33 44 / 10 40 30 30 20
GEORGETOWN MUNI AIRPORT 49 32 36 31 38 / 10 10 20 30 60
HONDO MUNI AIRPORT 56 36 39 33 42 / 10 20 20 30 40
SAN MARCOS MUNI AIRPORT 53 35 38 34 40 / 10 10 20 30 60
LA GRANGE - FAYETTE REGIONAL 55 36 41 36 42 / 10 10 20 30 50
SAN ANTONIO INTL AIRPORT 55 36 39 35 41 / 10 10 20 30 50
STINSON MUNI AIRPORT 56 38 39 36 41 / 10 10 20 30 50
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL NOON CST TODAY FOR THE FOLLOWING COUNTIES:
BANDERA...BEXAR...BLANCO...BURNET...COMAL...EDWARDS...GILLESPIE...
HAYS...KENDALL...KERR...KINNEY...LLANO...MAVERICK...MEDINA...REAL...
TRAVIS...UVALDE...VAL VERDE...WILLIAMSON...ZAVALA.
WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY MORNING
FOR THE FOLLOWING COUNTIES: BANDERA...BLANCO...BURNET...EDWARDS...
GILLESPIE...KENDALL...KERR...LLANO...REAL...VAL VERDE.
&&
$$
MESOSCALE/AVIATION...03
SYNOPTIC/GRIDS...12
PUBLIC SERVICE/DATA COLLECTION...00