Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 01/16/16
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
403 PM PST FRI JAN 15 2016
...SERIES OF SYSTEMS TO IMPACT OUR AREA THROUGH THE END OF NEXT
WEEK WITH THE STRONGEST SYSTEM EXPECTED SUNDAY EVENING INTO MONDAY
MORNING...
.SYNOPSIS...A WEAK SYSTEM IS EXPECTED TO MOVE ACROSS NORTHERN
CALIFORNIA LATER TODAY AND BRING RAIN BACK TO OUR AREA TONIGHT. A
SERIES OF SYSTEMS WILL AFFECT THE AREA SATURDAY THROUGH AT LEAST
THE END OF NEXT WEEK. THE STRONGEST SYSTEM IS SLATED FOR SUNDAY
EVENING INTO TUESDAY.
&&
.DISCUSSION...AS OF 1:00 PM PST FRIDAY...MIX OF CLOUDS AND SUN
ACROSS THE REGION TODAY WITH TEMPERATURES RUNNING CLOSE TO VALUES
24 HOURS AGO. TEMPS DO RANGE FROM THE LOWER 50S IN THE NORTH BAY
WHERE CLOUDS HAVE BEEN VERY SLOW TO BURN OFF, TO THE UPPER 50S TO
LOWER 60S FOR THE REST OF OUR AREA THAT ENJOYED MORE SUNSHINE.
A WEAK SYSTEM WILL MOVE TO THE COAST THIS EVENING WITH RAINFALL
FORECAST TO RETURN TO THE NORTH BAY FIRST THEN DOWN TO THE SF BAY
REGION LATE IN THE EVENING. THE RAIN WILL CONTINUE TO PROGRESS TO
THE SOUTH AND EAST OVERNIGHT WITH SAN JOSE AND MONTEREY BOTH
LOOKING AT START TIMES FOR PRECIPITATION AT OR JUST AFTER MIDNIGHT.
RAIN WILL SWITCH OVER TO SCATTERED SHOWERS BY LATE SATURDAY
MORNING. RAINFALL TOTALS WILL GENERALLY BE UNDER 1/3" FOR URBAN
SPOTS WITH LOCALLY 1/2" TO 1" IN THE COASTAL RANGES. HRRR DOES
INDICATE MORE WIDESPREAD LIGHT RAINFALL COMPARED TO YESTERDAY`S
SYSTEM, SO LOCATIONS THAT WERE DRY OR JUST GOT A TRACE YESTERDAY
SHOULD DO A BIT BETTER.
SUNDAY WILL START OUT GENERALLY DRY BEFORE THE MAIN SYSTEM OF THE
SERIES ADVANCES INTO THE REGION BEGINNING SUNDAY EVENING. MODELS
REMAIN IN FAIRLY GOOD AGREEMENT THAT RAIN WILL MOVE BACK TO THE
NORTH BAY IN THE EVENING AND THEN DOWN TO SF BAY AND MONTEREY BAY
REGION FOR THE OVERNIGHT HOURS. RAINFALL WILL LIKELY BE MODERATE
TO HEAVY AT TIMES AS THE FRONT GOES THROUGH THANKS IN PART TO PW
VALUES NEAR 1.3". ON THE POSITIVE SIDE, IT LOOKS LIKE THE HEAVIEST RAINFALL
WILL LIKELY COINCIDE WITH THE NIGHT BEFORE MLK HOLIDAY SUGGESTING
THAT TRAFFIC SHOULD BE AT EXTREMELY LOW LEVELS. RAINFALL TOTALS
WILL GENERALLY BE 1/2" TO 1" IN MANY URBAN SPOTS WITH 1-3" AT
COASTAL RANGES (ISOLATED 4+"). THE OTHER STORY WITH THIS SYSTEM
WILL BE LOCALLY GUSTY SOUTHERLY WINDS JUST AHEAD OF THE FRONT.
SOUTHERLY WINDS OF 15 TO 25 MPH GUSTING TO 35 MPH CAN BE EXPECTED
SUNDAY AFTERNOON INTO THE EVENING.
RAIN WILL AGAIN SWITCH TO SHOWERS WITH JUST LIGHT PRECIPITATION
EXPECTED FOR MONDAY AFTERNOON.
PREVIOUS MODEL GUIDANCE INDICATED A SECOND SLUG OF MOISTURE POISED
TO MOVE THROUGH LAST MONDAY INTO TUESDAY. HOWEVER THAT NOW APPEARS
MUCH LESS LIKELY BASED OFF OF THE ENSEMBLE PLUS MOST OPERATIONAL
MODELS. NOW APPEARS THAT INSTEAD A SHORTWAVE WILL MOVE TO THE PAC
NW COAST TUESDAY EVENING/NIGHT AND BRING SOME MORE LIGHT RAIN TO
OUR REGION. SINCE THIS WAS A HUGE CHANGE FROM THE PREVIOUS
PACKAGE, POPS AND QPF WERE BOTH GREATLY REDUCED FOR MONDAY NIGHT
INTO TUESDAY. HOWEVER, DID NOT FEEL COMFORTABLE GOING COMPLETELY
DRY WHICH SOME OF THE MODELS ARE NOW INDICATING. BOTTOM
LINE...MONDAY NIGHT INTO TUESDAY CURRENTLY LOOKS LIKE A NON-EVENT
WITH JUST LIGHT RAIN POSSIBLE IN THE WORST CASE.
BEYOND TUESDAY, ACTIVE PATTERN IS EXPECTED TO CONTINUE THROUGH
THE END OF THE MONTH.
&&
.AVIATION...AS OF 4:00 PM PST FRIDAY...FOR 00Z TAFS. APPROACHING
STORM SYSTEM WILL BRING RAIN TO THE AREA FROM NORTHWEST TO
SOUTHEAST BTWN 03Z SAT THROUGH 15Z SAT...THEN LINGERING RAIN
SHOWERS THROUGH 03Z SUN. CIGS WILL DETERIORATE INTO MVFR RANGE
EARLY IN THE EVENT... AND DROP INTO IFR RANGE FOR SOME LOCATIONS
AFTER 10-12Z SAT AND REMAIN IN IFR-MVFR RANGE THROUGH SATURDAY
MORNING. PREDOMINATELY SOUTH TO SOUTHEAST WINDS WILL PREVAIL
THROUGH THE TAF PERIOD... WITH BRIEF VARIABLE SHIFTS TO OTHER
DIRECTIONS.
VICINITY OF KSFO... VFR THROUGH 03Z SAT... THEN DETERIORATING CIGS
DOWN TO MVFR RANGE THROUGH REMAINDER OF TAF PERIOD. RA TO SHRA
FROM 05Z THROUGH END OF TAF PERIOD. PREDOMINATELY EAST WINDS
THROUGH THE MORNING THEN SOUTHEAST WINDS WILL PREVAIL THROUGH
MIDDAY SATURDAY. HEAVIEST RAIN CURRENTLY EXPECTED BETWEEN 06-10Z
SAT.
SFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...VFR CIGS WITH LIGHT VARIABLE WINDS
THROUGH THE DAYLIGHT HOURS. LIGHT SOUTHEAST WINDS AND INCREASING
MID CLOUDS BEGINNING AROUND 05-06Z SAT THEN DETERIORATING CIGS TO
MVFR/IFR RANGE AFTER 08-10Z. HEAVIEST RAIN SLOTTED BETWEEN 08-011Z
SAT.
&&
.MARINE...AS OF 2:30 PM PST FRIDAY...WINDS INCREASE AND SHIFT TO
BECOME SOUTHERLY NOW AND INTO THIS EVENING AHEAD OF AN APPROACHING
FRONT. THE STRONGEST WINDS WILL BE OVER THE NORTHERN OUTER WATERS
THROUGH SATURDAY. BY SATURDAY AFTERNOON A LARGE AND LONG PERIOD
SWELL TRAIN WILL SPREAD THROUGH THE WATERS WITH LARGE SEAS AND
SOUTHERLY WINDS THROUGH THE REST OF THE WEEKEND.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...SCA...PT ARENA TO PIGEON PT 10-60 NM
SCA...PT ARENA TO PT REYES 0-10 NM FROM 8 PM
SCA...PT REYES TO PIGEON PT 0-10 NM FROM 2 AM
SCA...ROUGH BAR ADVISORY FOR SF BAR FROM 2 AM
&&
$$
PUBLIC FORECAST: BELL
AVIATION: DRP/CW
MARINE: DRP
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AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
959 AM PST THU JAN 14 2016
...SERIES OF SYSTEMS TO IMPACT OUR AREA THROUGH THE END OF NEXT
WEEK...
.SYNOPSIS...A WEAK FRONTAL BOUNDARY WILL BRING A PERIOD OF LIGHT
RAIN TO THE DISTRICT LATER TODAY INTO FRIDAY MORNING. THEN A
SERIES OF SYSTEMS WILL AFFECT THE AREA SATURDAY THROUGH AT LEAST THE
END OF NEXT WEEK.
&&
.DISCUSSION...AS OF 8:35 AM PST TUESDAY...KEEPING A CLOSE EYE ON
THE HRRR THIS MORNING TO ADJUST THE TIMING OF RAIN FOR LATER TODAY
THROUGH THE OVERNIGHT HOURS. LAST RUN BRINGS RAIN TO NORTH BAY
STARTING JUST BEFORE NOON, TO THE CITY AROUND 2 PM, SAN JOSE CLOSE
TO 5 PM AND FINALLY TO MONTEREY EARLY IN THE EVENING. RAINFALL
AMOUNTS ARE STILL FAVORED FOR BE 1/10 TO 1/4" FOR MANY URBAN
LOCATIONS WITH LOCALLY MORE THAN 1/2" IN THE HILLS. RAIN WILL COME TO
AN END TONIGHT STARTING IN THE NORTH BAY FIRST. SECOND SYSTEM WILL
ON TRACK FOR LATE FRIDAY INTO SATURDAY WITH SIMILAR TOTALS.
BIGGER CONCERN CONTINUES TO CENTER AROUND SUNDAY THROUGH TUESDAY
AS A STRONGER SYSTEM MOVES THROUGH. PW VALUES ARE FORECAST TO BE
UP TO 1.3" WITH A CONNECTION WELL TO THE SSW . OVERALL LOOKS VERY
WET, HOWEVER THE QUESTION IS WILL IT BE A 1.5 TO TWO DAY EVENT
(WHICH THE OPERATIONAL 0Z ECMWF IS SHOWING) OR WILL THERE BE A 12
TO 18 HOUR BREAK IN THE MIDDLE (WHICH THE 12Z GFS INDICATES)?
LATEST CNRFC NUMBERS FOR THE TWO DAY PERIOD BRING WIDESPREAD
1-2.5" FOR URBAN LOCATIONS WITH 3-5" FOR MOST OF THE COASTAL
RANGES. SOUTHERLY WINDS WILL ALSO PICK UP AS THIS SYSTEM
APPROACHES. COULD BE QUITE BREEZY ON SUNDAY. WILL ISSUE AN SPS
LATER TODAY ONCE THE 12Z ECMWF COMES ACROSS.
.PREVIOUS DISCUSSION...TEMPERATURES ARE MUCH COOLER TONIGHT
ACROSS THE DISTRICT UNDER MOSTLY CLEAR SKIES. READINGS ARE RANGING
FROM THE UPPER 30S TO THE UPPER 40S...5-15 DEGREES COOLER THAN AT
YESTERDAY AT THIS TIME. THERE IS SOME PATCHY FOG IN THE NORTH
BAY...AND HIGH CLOUDS ARE SPREADING IN OVER NORTHERN
CALIFORNIA...OTHERWISE SKIES ARE MOSTLY CLEAR.
A WEAK FRONTAL BOUNDARY OVER THE EASTERN PACIFIC WILL APPROACH
NORTHERN CALIFORNIA LATER TODAY THEN PASS OVER THE AREA FRIDAY
MORNING. LIGHT RAIN IS EXPECTED TO BEGIN IN THE NORTH BAY LATER
THIS AFTERNOON...THEN SPREAD SOUTH THROUGH THE GREATER SAN
FRANCISCO BAY AREA OVERNIGHT. THE BULK OF THE RAINFALL IS EXPECTED
TO FALL IN THE NORTH BAY MOUNTAINS WITH TOTALS IN THE 1/2 TO 1
INCH RANGE THERE. THE REST OF THE CWA SHOULD SEE A QUARTER OF AN
INCH OR LESS...ESPECIALLY THE FARTHER SOUTH YOU GO. THE NEXT
FRONTAL BOUNDARY WILL MOVE THROUGH THE AREA FRIDAY NIGHT AND
SATURDAY WITH ANOTHER PERIOD OF MOSTLY LIGHT RAIN WITH SIMILAR
RAINFALL TOTALS.
A POTENTIALLY WETTER SERIES OF STORMS IS SLATED FOR ARRIVAL ON
SUNDAY AND CONTINUING THROUGH TUESDAY. THERE ARE STILL SOME
DISCREPANCIES BETWEEN THE FORECAST MODELS CONCERNING TIMING AND
INTENSITY OF THESE STORMS...HOWEVER CONFIDENCE IS IMPROVING THAT
THESE COULD BRING FAIRLY SIGNIFICANT RAINFALL TO THE AREA DURING
THE SUNDAY THROUGH TUESDAY TIME FRAME. A ROUGH ESTIMATE OF
RAINFALL OF 2 TO 5 INCHES OVER THE DISTRICT...WITH THE HIGHEST
AMOUNTS OVER THE COASTAL MOUNTAINS...THROUGH THIS PERIOD IS NOT
OUT OF THE QUESTION AS A SUBTROPICAL CONNECTION IS INDICATED. IN
ADDITION...THE PARENT LOW CURRENTLY OUT NEAR 41N 165W IS ALREADY
GENERATING STRONG WINDS AND SEAS WHICH WILL MAKE FOR A COUPLE OF
DAYS OF CHALLENGING WEATHER EARLY NEXT WEEK.
LOOKING BEYOND...UNSETTLED WEATHER IS EXPECTED TO PERSIST THROUGH
NEXT WEEK.
&&
.AVIATION...AS OF 9:43 PM PST THURSDAY...A MIX OF SCATTERED LOW
CLOUDS UNDER A BLANKET OF HIGH CLOUDS WILL PREVAIL THROUGH THE
MORNING ACROSS MOST AREA TERMINALS. AN APPROACHING WEAK FRONTAL
SYSTEM WILL RESULT IN LOWERING CIGS AND VSBYS THIS AFTERNOON AND
EVENING. RAIN CHANCES WILL BEGIN AROUND 21Z IN THE NORTH BAY WITH
A FEW SHOWERS POSSIBLE OVER THE SAN FRANCISCO BAY AREA AS WELL.
LIGHT RAIN WILL SPREAD SOUTH REACHING TERMINALS SOUTH OF SAN
FRANCISCO AROUND 06Z TONIGHT. SHOWERS WILL GRADUALLY COME TO AN
END BY SUNRISE FRIDAY WITH A FEW LINGERING SHOWERS POSSIBLE
THROUGH 17Z. MODERATE TO HIGH CONFIDENCE.
VICINITY OF KSFO...VFR CONDITIONS THROUGH THE MORNING HOURS. LIGHT
SHOWERS POSSIBLE AFTER 21Z WITH LIGHT RAIN EXPECTED AFTER 01Z THIS
AFTERNOON. SHOWERS EXPECTED TO END BY 12Z. AN ISOLATED SHOWER CAN
NOT BE RULED OUT. LIGHT TO MODERATE SOUTHERLY WINDS EXPECTED
THROUGH THE PERIOD. STRONGEST WINDS ANTICIPATED AROUND 01Z-04Z.
SFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...VFR CONDITIONS WILL PREVAIL. LIGHT
TO LOCALLY MODERATE WINDS. MVFR CIGS AND LIGHT RAIN ANTICIPATED TO
DEVELOP AROUND 07Z.
&&
.MARINE...AS OF 09:43 AM PST THURSDAY...SOUTHERLY WINDS WILL
INCREASE TODAY AS ANOTHER COLD FRONT MOVES THROUGH THE REGION.
WINDS WILL BRIEFLY DECREASE FRIDAY AND THEN INCREASE AGAIN OVER
THE WEEKEND AS A MUCH STRONGER STORM APPROACHES THE REGION.
ADDITIONALLY...SEAS WILL INCREASE OVER THE WEEKEND AS A LONG
PERIOD SWELL ENTERS THE COASTAL WATERS.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...SCA...PT ARENA TO PT REYES 0-10 NM UNTIL 9 PM
SCA...PT REYES TO PIGEON PT 0-10 NM UNTIL 9 PM
SCA...PT ARENA TO PIGEON PT 10-60 NM UNTIL 9 PM
SCA...ROUGH BAR ADVISORY FOR SF BAR UNTIL 9 PM
&&
$$
PUBLIC FORECAST: BELL/SIMS
AVIATION: CW
MARINE: MM/CW
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AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
836 AM PST THU JAN 14 2016
...SERIES OF SYSTEMS TO IMPACT OUR AREA THROUGH THE END OF NEXT
WEEK...
.SYNOPSIS...A WEAK FRONTAL BOUNDARY WILL BRING A PERIOD OF LIGHT
RAIN TO THE DISTRICT LATER TODAY INTO FRIDAY MORNING. THEN A
SERIES OF SYSTEMS WILL AFFECT THE AREA SATURDAY THROUGH AT LEAST THE
END OF NEXT WEEK.
&&
.DISCUSSION...AS OF 8:35 AM PST TUESDAY...KEEPING A CLOSE EYE ON
THE HRRR THIS MORNING TO ADJUST THE TIMING OF RAIN FOR LATER TODAY
THROUGH THE OVERNIGHT HOURS. LAST RUN BRINGS RAIN TO NORTH BAY
STARTING JUST BEFORE NOON, TO THE CITY AROUND 2 PM, SAN JOSE CLOSE
TO 5 PM AND FINALLY TO MONTEREY EARLY IN THE EVENING. RAINFALL
AMOUNTS ARE STILL FAVORED FOR BE 1/10 TO 1/4" FOR MANY URBAN
LOCATIONS WITH LOCALLY MORE THAN 1/2" IN THE HILLS. RAIN WILL COME TO
AN END TONIGHT STARTING IN THE NORTH BAY FIRST. SECOND SYSTEM WILL
ON TRACK FOR LATE FRIDAY INTO SATURDAY WITH SIMILAR TOTALS.
BIGGER CONCERN CONTINUES TO CENTER AROUND SUNDAY THROUGH TUESDAY
AS A STRONGER SYSTEM MOVES THROUGH. PW VALUES ARE FORECAST TO BE
UP TO 1.3" WITH A CONNECTION WELL TO THE SSW . OVERALL LOOKS VERY
WET, HOWEVER THE QUESTION IS WILL IT BE A 1.5 TO TWO DAY EVENT
(WHICH THE OPERATIONAL 0Z ECMWF IS SHOWING) OR WILL THERE BE A 12
TO 18 HOUR BREAK IN THE MIDDLE (WHICH THE 12Z GFS INDICATES)?
LATEST CNRFC NUMBERS FOR THE TWO DAY PERIOD BRING WIDESPREAD
1-2.5" FOR URBAN LOCATIONS WITH 3-5" FOR MOST OF THE COASTAL
RANGES. SOUTHERLY WINDS WILL ALSO PICK UP AS THIS SYSTEM
APPROACHES. COULD BE QUITE BREEZY ON SUNDAY. WILL ISSUE AN SPS
LATER TODAY ONCE THE 12Z ECMWF COMES ACROSS.
.PREVIOUS DISCUSSION...TEMPERATURES ARE MUCH COOLER TONIGHT
ACROSS THE DISTRICT UNDER MOSTLY CLEAR SKIES. READINGS ARE RANGING
FROM THE UPPER 30S TO THE UPPER 40S...5-15 DEGREES COOLER THAN AT
YESTERDAY AT THIS TIME. THERE IS SOME PATCHY FOG IN THE NORTH
BAY...AND HIGH CLOUDS ARE SPREADING IN OVER NORTHERN
CALIFORNIA...OTHERWISE SKIES ARE MOSTLY CLEAR.
A WEAK FRONTAL BOUNDARY OVER THE EASTERN PACIFIC WILL APPROACH
NORTHERN CALIFORNIA LATER TODAY THEN PASS OVER THE AREA FRIDAY
MORNING. LIGHT RAIN IS EXPECTED TO BEGIN IN THE NORTH BAY LATER
THIS AFTERNOON...THEN SPREAD SOUTH THROUGH THE GREATER SAN
FRANCISCO BAY AREA OVERNIGHT. THE BULK OF THE RAINFALL IS EXPECTED
TO FALL IN THE NORTH BAY MOUNTAINS WITH TOTALS IN THE 1/2 TO 1
INCH RANGE THERE. THE REST OF THE CWA SHOULD SEE A QUARTER OF AN
INCH OR LESS...ESPECIALLY THE FARTHER SOUTH YOU GO. THE NEXT
FRONTAL BOUNDARY WILL MOVE THROUGH THE AREA FRIDAY NIGHT AND
SATURDAY WITH ANOTHER PERIOD OF MOSTLY LIGHT RAIN WITH SIMILAR
RAINFALL TOTALS.
A POTENTIALLY WETTER SERIES OF STORMS IS SLATED FOR ARRIVAL ON
SUNDAY AND CONTINUING THROUGH TUESDAY. THERE ARE STILL SOME
DISCREPANCIES BETWEEN THE FORECAST MODELS CONCERNING TIMING AND
INTENSITY OF THESE STORMS...HOWEVER CONFIDENCE IS IMPROVING THAT
THESE COULD BRING FAIRLY SIGNIFICANT RAINFALL TO THE AREA DURING
THE SUNDAY THROUGH TUESDAY TIME FRAME. A ROUGH ESTIMATE OF
RAINFALL OF 2 TO 5 INCHES OVER THE DISTRICT...WITH THE HIGHEST
AMOUNTS OVER THE COASTAL MOUNTAINS...THROUGH THIS PERIOD IS NOT
OUT OF THE QUESTION AS A SUBTROPICAL CONNECTION IS INDICATED. IN
ADDITION...THE PARENT LOW CURRENTLY OUT NEAR 41N 165W IS ALREADY
GENERATING STRONG WINDS AND SEAS WHICH WILL MAKE FOR A COUPLE OF
DAYS OF CHALLENGING WEATHER EARLY NEXT WEEK.
LOOKING BEYOND...UNSETTLED WEATHER IS EXPECTED TO PERSIST THROUGH
NEXT WEEK.
&&
.AVIATION...AS OF 5:43 AM PST THURSDAY..QUICK UPDATE THIS MORNING
MAINLY FOR SF BAY. LOW CLOUDS HAVE FORMED WITH THE LATE NIGHT
COOLING AND AMPLE LOW LEVEL MOISTURE. UPDATED KSFO AND KOAK TO
SHOW CIGS 1500-2500 FT. AS A FIRST GUESS WILL SHOOT FOR 17Z.
OTHERWISE...MAINLY HIGH CLOUDS IN THE SHORT TERM...BUT CIGS WILL
LOWER LATER TODAY AS RAIN MOVES IN FROM N TO S. FOR MOST LOCATIONS
NOT EXPECTING ANY PRECIP UNTIL AFTER 00Z. WET CONDITIONS WITH
SOUTHERLY WINDS FOR FRIDAY AM. CONF MODERATE.
VICINITY OF KSFO...MVFR THROUGH THE EARLY MORNING THEN VFR THIS
AFTERNOON...CONCERN IS BURN OFF COULD BE SLOW OR NOT AT ALL AS
HIGH CLOUDS CONTINUE TO INCREASE. VCSH SHORTLY AFTER 00Z...BUT
CHC FOR PRECIP BY 04-06Z. PRECIP TAPERING OFF TOWARD THE END OF
THE TAF...14Z
SFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...VFR AND LIGHT WINDS. CIGS AND PRECIP
DEVELOPING AROUND 06-08Z
&&
.MARINE...AS OF 8:35 AM PST THURSDAY...SOUTHERLY WINDS WILL
INCREASE TODAY AS ANOTHER COLD FRONT MOVES THROUGH THE REGION.
WINDS WILL BRIEFLY DECREASE FRIDAY AND THEN INCREASE AGAIN OVER
THE WEEKEND AS A MUCH STRONGER STORM APPROACHES THE REGION.
ADDITIONALLY...SEAS WILL INCREASE OVER THE WEEKEND AS A LONG
PERIOD SWELL ENTERS THE COASTAL WATERS.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...SCA...PT ARENA TO PT REYES 0-10 NM FROM 9 AM
SCA...PT REYES TO PIGEON PT 0-10 NM FROM 9 AM
SCA...PT ARENA TO PIGEON PT 10-60 NM FROM 9 AM
SCA...ROUGH BAR ADVISORY FOR SF BAR
&&
$$
PUBLIC FORECAST: BELL/SIMS
AVIATION: MM
MARINE: MM
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AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
334 AM MST THU JAN 14 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 334 AM MST THU JAN 14 2016
A QUICK MOVING UPPER LEVEL TROUGH WILL MOVE ACROSS THE AREA TODAY
AND THEN BE EAST OF THE AREA BY EARLY EVENING. CROSS-SECTIONS SHOW
MOISTURE DEPTH WITH THIS SYSTEM TO BE RATHER SHALLOW HOWEVER LAPSE
RATES WILL BE FAVORABLE ESPECIALLY THIS AFTN AND EVENING. OVERALL
SNOW AMOUNTS IN THE MTNS WILL BE ON THE LIGHT SIDE. WINDS WILL
REMAIN GUSTY OVER THE HIGHER TERRAIN THRU THE AFTN HOWEVER SPEEDS
WILL STAY BLO HIGH WIND CRITERIA. OVER NERN CO BNDRY LYR WINDS ARE
FCST AROUND 50 KTS THRU 18Z AND THEN AROUND 40 KTS IN THE AFTN
ESPECIALLY CLOSER TO THE WY-NE BORDER AREA AS A PACIFIC FNT MOVES
ACROSS. AS MIXING OCCURS LATER THIS MORNING INTO THE AFTN HOURS
MAY SEE SOME GUSTS UP TO 50 MPH AT TIMES NR THE WY-NE BORDER WITH
30 TO 40 MPH GUSTS FURTHER SOUTH. AS FOR HIGHS WILL KEEP READINGS
MAINLY IN THE 35 TO 45 DEGREE RANGE ACROSS NERN CO WITH THE
COLDEST TEMPS ACROSS WELD...MORGAN AND LOGAN COUNTIES.
FOR TONIGHT DRIER AIR WILL MOVE INTO THE MTNS SO SNOW ACTIVITY
SHOULD DECREASE DURING THE EVENING HOURS. WINDS WILL REMAIN GUSTY
OVER THE HIGHER TERRAIN WITH SPEEDS STAYING BLO HIGHLIGHT CRITERIA
AS COMPONENT ALONG WINDS ARE ONLY IN THE 35-40 KT RANGE.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 334 AM MST THU JAN 14 2016
A SERIES OF UPPER LEVEL DISTURBANCES WILL BRING UNSETTLED WEATHER
TO THE REGION THROUGH AT LEAST THE MIDDLE OF NEXT WEEK. THE MAIN
IMPACT WILL BE PERIODS OF ACCUMULATING SNOW AND BLOWING SNOW IN
THE MOUNTAINS...WITH ALSO A COUPLE OPPORTUNITIES FOR LIGHT SNOW
ON THE PLAINS.
THE SECOND WAVE IN THIS SERIES CURRENTLY OFF THE WEST COAST WILL
MOVE ONSHORE BY THIS EVENING...AND THEN MOVE QUICKLY EAST/
SOUTHEAST ACROSS UTAH AND COLORADO FRIDAY. THIS WILL BRING AN
INCREASE IN MOISTURE DEPTH AND SPECIFIC HUMIDITY...ALONG WITH A
MORE FAVORABLE OROGRAPHIC COMPONENT FROM THE WEST/NORTHWEST BY
LATE IN THE DAY. LAPSE RATES ALSO INCREASE TO AROUND 7 C/KM WITH
THIS WAVE. AS A RESULT...HIGH COUNTRY SNOW WILL BECOME MORE
WIDESPREAD AND HEAVIER DURING THE AFTERNOON HOURS. THIS SNOW WILL
PERSIST INTO FRIDAY NIGHT BEFORE DECREASING LATE FRIDAY NIGHT INTO
EARLY SATURDAY MORNING AS MOISTURE DEPTH DECREASES IN WAKE OF
PASSING SHORT WAVE ENERGY. WITH THE PARAMETERS MENTIONED
ABOVE...SHOULD SEE 3 TO 8 INCHES OF SNOW OVER MOST OF THE MOUNTAIN
AREAS ABOVE 9000 FEET...WITH LOCALLY HIGHER AMOUNTS TO AROUND 1
FOOT IN THE RABBIT EARS PASS AREA. WINDS ALSO STRONG ENOUGH TO
PRODUCE SOME BLOWING SNOW OVER THE HIGHER ELEVATIONS AND COULD
SEE STRONG GUSTS TO 60 MPH OR MORE OVER THE HIGHEST PEAKS LATE
FRIDAY NIGHT WHEN UPPER LEVEL SPEED MAX PASSES OVERHEAD. ENOUGH
IMPACT FOR RELATIVELY HIGH POTENTIAL OF A WINTER WEATHER ADVISORY
FOR FRIDAY AFTERNOON THROUGH FRIDAY NIGHT ABOVE 9000 FEET.
ON THE PLAINS...THE AFOREMENTIONED WEATHER DISTURBANCE WILL ALSO
BRING POTENTIAL FOR SNOW. SOME MODELS LIKE THE GFS ARE QUITE
AMBITIOUS WITH PRECIPITATION POTENTIAL WHILE OTHER LIKE THE ECMWF
ARE DRIER. THERE ARE A COUPLE FAVORABLE FACTORS FOR PRECIPITATION
ON THE PLAINS...WEAK FRONT...DECENT LAPSE RATES...AND JET CORE TO
OUR WEST. GIVEN THIS...THINK THERE WILL AT LEAST BE ONE BAND THAT
DEVELOPS ON THE PLAINS BY LATE FRIDAY AFTERNOON OR EVENING AND
REMAINS OVERNIGHT. WILL INCREASE POPS FOR MOST OF THE PLAINS AT
THIS TIME GIVEN THE ABOVE MENTIONED PARAMETERS. POTENTIAL FOR
LOCAL ACCUMULATIONS OF AN INCH OR TWO BUT VERY DIFFICULT TO PIN
POINT AT THIS TIME.
AFTER SOME DRYING FOR SATURDAY...THE NEXT WAVE IS EXPECTED TO
ARRIVE BY SATURDAY NIGHT INTO SUNDAY. THERE IS VERY LITTLE IN THE
WAY OF COLD ADVECTION BUT A FAVORABLE WEST/NORTHWEST FLOW AND
ANOTHER BUT EVEN RICHER AIRMASS WILL BRING ANOTHER ROUND OF
ACCUMULATING SNOW TO THE HIGH COUNTRY. THERE WILL ALSO BE ANOTHER
THREAT OF BANDED LIGHT SNOW ON THE PLAINS...SO HAVE NUDGED POPS UP
JUST A BIT FOR THAT. HARD TO SAY HOW MUCH OF A FRONTAL SURGE IS
POSSIBLE BUT WE ARE IN NORTHWEST FLOW ALLOWING A DECENT POTENTIAL
OF A WEAK SURGE SATURDAY NIGHT OR SUNDAY MORNING.
WHILE MODELS STILL INDICATE AN ACTIVE PATTERN INTO THE MID PART OF
NEXT WEEK...THEY DIVERGE CONSIDERABLY WITH TIMING OF INDIVIDUAL
WAVES. AT THIS TIME...THINK THE ECMWF AND CANADIAN BLEND HAVE THE
RIGHT IDEA WITH SOME RIDGING AND WARMING FOR MONDAY INTO TUESDAY...BUT
WILL KEEP THE CHANCE OF SNOW GOING IN THE HIGH COUNTRY WITH
POTENTIAL FOR EMBEDDED WAVES. TEMPERATURES SHOULD TREND BACK TO
NEAR NORMAL LEVELS...BUT THEN COOLING AND A CHANCE OF SNOW
RETURNING TO THE PLAINS WEDNESDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 334 AM MST THU JAN 14 2016
VFR TODAY AND TONIGHT. WINDS EARLY THIS MORNING WERE SSW HOWEVER
THE HRRR SHIFTS THEM TO MORE WNW AROUND 12Z AND KEEPS THEM THAT
GENERAL DIRECTION THRU THE AFTN HOURS. AS MIXING OCCURS LATER THIS
MORNING SOME GUSTS UP TO 30 MPH WILL BE POSSIBLE THRU THE AFTN. BY
LATE AFTN WINDS ARE FCST TO WEAKEN AND THEN SHIFT BACK TO MORE SSW
BY 01Z WITH DRAINAGE WINDS OVERNIGHT.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RPK
LONG TERM...BARJENBRUCH
AVIATION...RPK
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1007 PM EST FRI JAN 15 2016
.SYNOPSIS...
A RAPIDLY INTENSIFYING LOW PRESSURE SYSTEM WILL ACCELERATE
NORTHEAST PASSING SOUTHEAST OF LONG ISLAND SATURDAY MORNING AND
EAST OF NEW ENGLAND DURING THE DAY SATURDAY. WEAK HIGH PRESSURE
WILL MOVE IN SATURDAY NIGHT. LOW PRESSURE WILL TRACK WELL
SOUTHEAST OF LONG ISLAND SUNDAY NIGHT. A COUPLE OF POLAR FRONTS
WILL CROSS THE REGION LATE SUNDAY NIGHT THROUGH TUESDAY MORNING.
WEAK HIGH PRESSURE RETURNS FOR MID WEEK...WITH A COLD FRONT
PASSING THROUGH LATE WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
LOW PRESSURE WAS RAPIDLY INTENSIFYING ALONG THE NC COAST WITH 3
HOUR PRES FALLS OF 10 MB OFF THE VA COAST.
BASED ON RAPID DEEPENING OF THE LOW WITHOUT AN INTERACTING HIGH
PRESSURE SYSTEM...A COMPACT TIGHT WIND FIELD WILL RAPIDLY DEVELOP
AS THE LOW MVS NORTHEAST AND OFFSHORE.
USING A COMPROMISE OF THE 12Z ECMWF AND THE 18Z GFS...AND HOURLY
BUFKIT SOUNDINGS...ISSUED A SHORT FUSE WIND ADVISORY FOR THE TWIN
FORKS AND A GALE WARNING FOR THE EASTERN COASTAL WATERS FROM 4 AM
UNTIL 10 AM SATURDAY MORNING...MAINLY FOR SUSTAINED WINDS OF 30-35
KT.
THE NAM CONTS TO RUN A DEEPER LOW ON THE NW SIDE OF THE FCST
SOLUTIONS WHILE THE HRRR SHOWS A LESS INTENSE SYSTEM ON THE SE
SIDE OF THE FCST SOLUTIONS.
RAIN CONTS TO ADVECT NE AND DEVELOP ACROSS THE REGION. THE
HEAVIEST RAIN WILL OCCUR FROM 06Z TO 12Z AND RAPIDLY TAPER OFF AS
THE LOW ACCELERATES NORTHEAST AND OFFSHORE SATURDAY MORNING.
TEMPERATURES WILL BE WARM ENOUGH FOR PLAIN RAIN EVERYWHERE. THE
ONLY PLACE THAT NEEDS TO BE WATCHED WILL BE ACROSS ORANGE COUNTY
WHERE TEMPERATURES MAY FALL BETWEEN 33-35 DEGREES. THERE IS A LOW
CHC FOR A BRIEF PERIOD OF FREEZING RAIN.
OTHERWISE...EXPECT A PERIOD OF MODERATE RAIN LATE TONIGHT INTO
EARLY SATURDAY. RAINFALL TOTALS ARE EXPECTED TO RANGE FROM A HALF
INCH TO JUST OVER ONE INCH...WITH THE HIGHEST VALUES ACROSS
EASTERN LONG ISLAND AND EASTERN CT. THE LOW MOVES QUICKLY AND RAIN SHOULD
COME TO AN END SATURDAY MORNING. EXPECT A DRY/BRISK AFTERNOON AS
WEST- NORTHWEST WINDS ON THE BACK SIDE OF THE LOW INCREASE TO
15-25 MPH.
&&
.SHORT TERM /SATURDAY NIGHT/...
HIGH PRESSURE BUILDS IN SATURDAY NIGHT WITH DRY CONDITIONS. WINDS
WILL GRADUALLY DIMINISH AND WITH MOSTLY CLEAR SKIES...EXPECT LOWS TO
FALL INTO THE 20S AND LOWER 30S. USED A MAV/MET BLEND FOR
TEMPERATURES IN THE SHORT TERM.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
A RETURN TO TEMPS SEVERAL DEGREES BELOW NORMAL FOR THE NEW WEEK.
MODELS IN GENERAL AGREEMENT WITH A POLAR LOW TRACKING THROUGH THE
GREAT LAKES SUNDAY INTO SUNDAY NIGHT...EAST THROUGH NEW ENGLAND ON
MONDAY...AND THEN INTO EASTERN CANADA THROUGH WED. ALTHOUGH THE
POLAR TROUGH AXIS SLIDES EAST BY TUE NIGHT...MEAN CONUS TROUGHING
WILL CONTINUE THROUGH THE WEAK...BECOMING AMPLIFIED LATE IN THE WEEK
AS A NORTHERN STREAM TROUGH DIGS INTO THE NORTHEAST.
AT THE SURFACE...ONE POLAR FRONT MOVES THROUGH THE REGION LATE SUN
NIGHT/EARLY MON AND A SECOND LATE MONDAY NIGHT INTO TUE MORNING.
THIS WILL BRING A MODERATING ARCTIC AIRMASS INTO THE REGION FOR THE
EARLY WEEK...WITH HIGH TEMPS LIKELY NOT GETTING OUT OF THE 20S MON
THRU TUE...WITH LOWS IN THE TEENS MON NIGHT. WITH WNW WINDS OF 15 TO
25 MPH AND GUSTS IN THE 30S LIKELY...WIND CHILLS IN THE SINGLE
DIGITS AND TEENS LIKELY MON AND TUE...WITH POTENTIAL FOR SUBZERO
WIND CHILLS 0 TO 5 BELOW ZERO MON NIGHT. HIGH TEMPS SHOULD
MODERATE SLIGHTLY FOR THE MID TO LATE WEEK IN THE WAKE OF THE
POLAR LOW...BUT LIKELY NOT GET MUCH ABOVE THE UPPER 20S/LOWER 30S
FOR THE REMAINDER OF THE WEEK WITH REGION UNDER INFLUENCE OF
NORTHERN STREAM.
IN TERMS OF PRECIP...NO SIGNALS FOR SIGNIFICANT WEATHER AT THIS
TIME. MODELS IN GOOD AGREEMENT WITH PAC ENERGY OVER CALIFORNIA
TODAY...RACING ACROSS THE SOUTHERN US AND SLIDING AROUND THE POLAR
LOW INTO THE WESTERN ATLANTIC SUNDAY NIGHT. DETERMINISTIC MODELS AND
ENSEMBLE MEANS ARE KEEPING THIS ENERGY UNPHASED...WITH A SOUTHERN
LOW TRACKING WELL SE OF THE 40/70 BENCHMARK SUN NIGHT. SBU ENSEMBLE
SENSITIVITY SIGNALING SOME ENSEMBLE SPREAD WITH THE TRACK OF THIS
LOW...BUT MAINLY DUE TO STRENGTH DIFFERENCES...NOT TRACK. THIS
OFFSHORE TRACK SHOULD KEEP THE MAIN PRECIP SHIELD WITH THIS STORM
WELL OFFSHORE LATE SUN/SUN NIGHT. IT APPEARS MORESO DUE TO LIFT FROM
THE SOUTHERN STREAM SHORTWAVE ENERGY ROUNDING THE UPPER LOW THAT THE
REGION HAS POTENTIAL FOR SOME LIGHT SNOW SHOWERS LATE SUN/SUN EVE.
BETTER CHANCE FOR SNOW SHOWERS LOOKS TO BE LATE SUN NIGHT THROUGH
MON AS THE POLAR FRONT MOVES THROUGH AND THEN AS POLAR LOW AND
ASSOCIATED VORT MOVES INTO THE REGION...COMBINING WITH RESIDUAL LAKE
MOISTURE AND LOW-LEVEL INSTABILITY. MODELS LOOKS TO BE SIGNALING
BETTER CHANCE FOR STEADIER LIGHT SNOW SUN NIGHT/MON TO THE NORTH OF
THE REGION WITH INVERTED TROUGH/WEAK CLIPPER ORIENTING IN THE PATH
OF THE UPPER LOW. FINALLY...PERHAPS SOME ISOLATED SNOW SHOWERS OR
FLURRIES LATE MON NIGHT/TUE MORNING AS THE POLAR LOW TROUGH AXIS
MOVES THROUGH.
THEREAFTER...POTENTIAL FOR LIGHT PRECIP LATE WEEK...BUT LOW
CONFIDENCE ON TIMING WITH MODELS DIVERGING ON THE EVOLUTION OF
DIGGING NORTHERN STREAM ENERGY.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
A DEEPENING LOW PRESSURE SYSTEM TRACK UP THE COAST TONIGHT AND
WILL BE LOCATED SOUTH AND EAST OF LONG ISLAND SATURDAY MORNING.
THE LOW WILL QUICKLY MOVE NE OF THE AREA DURING THE DAY.
GENERALLY LIGHT WINDS THIS EVENING WILL INCREASE OVERNIGHT OUT OF
THE NE. SPEEDS AROUND 10 TO 15 KT WITH GUSTS 20 TO 25 KT AFTER 09Z.
STRONGEST GUSTS ARE MOST LIKELY TO OCCUR AT COASTAL TERMINALS. WINDS
BACK TO THE NW IN THE MORNING. GUSTS MAY SUBSIDE BRIEFLY LATE
SATURDAY MORNING...BUT SHOULD PICK UP AGAIN IN THE AFTERNOON.
VFR CONDITIONS THIS EVENING...EXCEPT MVFR CIGS AT KGON...UNTIL AFTER
06Z. MVFR CIGS ARE THEN LIKELY AT ALL TERMINALS WITH POSSIBLE BRIEF
IFR CIGS WITHIN RAIN. IFR VISIBILITIES ARE MOST LIKELY WITH THE
HEAVIER RAINFALL.
RAIN ENDS SATURDAY MORNING WITH IMPROVING CONDITIONS TO VFR AT MOST
TERMINALS.
MODERATE FORECAST CONFIDENCE TONIGHT INTO SAT AM...ESPECIALLY FOR
TIMING OF WIND SHIFTS AND CHANGING FLIGHT CATEGORIES.
.OUTLOOK FOR 00Z SUN THROUGH WED...
.SAT NIGHT-SUN...VFR.
.SUN NIGHT-MON NIGHT...MVFR OR LOWER CONDS AT TIMES IN SNOW SHOWERS.
NW WINDS G25-30KT ON MON.
.TUE...VFR. NW WINDS G25-30KT
.WED...VFR.
&&
.MARINE...
A GALE WARNING IS IN EFFECT 4 AM - 10 AM SATURDAY FROM MORICHES
INLET EAST TO MONTAUK AND THE EASTERN INLAND BAYS. GUSTS MAY
APPROACH 34 KT ACROSS PARTS OF THE FAR EASTERN SOUND DURING THIS
TIME.
OTHERWISE...A SMALL CRAFT ADVISORY REMAINS IN EFFECT FROM 1 AM
SATURDAY TO 6 AM EST SUNDAY FOR THE REST OF THE COASTAL WATERS.
SOUTH WINDS THIS EVENING WILL GRADUALLY BECOME NORTHEAST...THEN
INCREASE AND BECOME NORTHWEST LATE TONIGHT AND SATURDAY MORNING.
AS LOW PRESSURE MOVES OFF THE MID-ATLANTIC COAST AND PASSES SOUTH
AND EAST OF LONG ISLAND EXPECT WIND GUSTS NEAR 34 KT. SEAS WILL
ALSO INCREASE TO 5 FT LATE TONIGHT...AND EVENTUALLY 7-10 FT DURING
THE DAY SATURDAY. WIND AND SEAS WILL GRADUALLY SUBSIDE LATE
SATURDAY NIGHT.
SUB SCA CONDS EXPECTED SUN INTO SUN EVE WITH A WEAK GRADIENT ACROSS
THE REGION.
OTHERWISE...DEVELOPING SCA CONDITIONS SUN NIGHT IN WAKE OF DEPARTING
OFFSHORE LOW. THEN GALE CONDITIONS POSSIBLE ON ALL WATERS MON
THROUGH TUE WITH STEEP LAPSE RATES AND TIGHT WNW GRADIENT IN WAKE OF
POLAR FRONT. CONDITIONS SHOULD GRADUALLY SUBSIDE TO SCA TUE NIGHT
AND THEN EVENTUALLY SUB SCA FOR MIDWEEK AS HIGH PRESSURE BUILDS
TOWARDS THE WATERS.
&&
.HYDROLOGY...
QPF OF 1/2 TO 1 INCH EXPECTED FRI NIGHT INTO SAT MORNING...WITH
LOCALLY HIGHER AMOUNTS POSSIBLE. THE HIGHEST AMOUNTS WILL BE ACROSS
THE EASTERN PORTIONS OF LONG ISLAND AND CONNECTICUT. P-TYPE SHOULD
BE ALL LIQUID.
NO SIGNIFICANT PRECIPITATION IS EXPECTED SUNDAY THROUGH FRIDAY.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...WIND ADVISORY FROM 4 AM TO 10 AM EST SATURDAY FOR NYZ079-081.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM TO 1 PM EST SATURDAY FOR ANZ330-
345.
GALE WARNING FROM 4 AM TO 10 AM EST SATURDAY FOR ANZ340-350.
SMALL CRAFT ADVISORY FROM 1 AM SATURDAY TO 6 AM EST SUNDAY FOR
ANZ353-355.
&&
$$
SYNOPSIS...BC/GC/NV
NEAR TERM...BC/GC
SHORT TERM...BC
LONG TERM...NV
AVIATION...DS
MARINE...BC/GC/NV
HYDROLOGY...BC/GC/NV
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
506 AM EST THU JAN 14 2016
.SYNOPSIS...
A WEAK UPPER AIR FEATURE WILL CROSS THE AREA THIS MORNING...FOLLOWED
BY HIGH PRESSURE FOR TONIGHT AND FRIDAY. LOW PRESSURE WILL DEVELOP
OFF THE SOUTHEAST U.S. COAST FRIDAY AND MOVE ACROSS OUR OFFSHORE
WATERS FRIDAY NIGHT AND SATURDAY. A COLD FRONT WILL CROSS THE
AREA SUNDAY...FOLLOWED BY HIGH PRESSURE WHICH WILL BUILD IN FOR
MONDAY AND PERSIST INTO THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
DID A QUICK UPDATE FOR SNOW SHOWERS MOVING ACROSS NRN NJ AND
ADJACENT PA. SEEING SOME 25 DBZ ECHOES ON RADAR BUT NOT SURE HOW
MUCH IS ACTUALLY REACHING THE GROUND. SOME SITES ARE REPORTING
VSBY TEMPORARILY REDUCED TO 1.5 TO 3 MILES. ANY ACCUM IN OUR AREA
EXPECTED TO BE LESS THAN AN INCH.
A MID-LEVEL SHRTWV TROF CONTS TO ROTATE THROUGH BROADLY CYCLONIC
FLOW ALOFT OVER THE AREA. THE TROF APPEARS TO BE MOVG THRU WRN/CNTRL
PA AS OF 08Z AND SHOULD BE OFF THE EAST COAST BY 12Z. RADAR LOOP
SHOWS SOME AREAS OF LIGHT SNOW AHEAD OF THE TROF OVER ERN PA...HWVR
THE LOW-LEVEL AIR MASS IS QUITE DRY SO MOST SNOW SHOULD EVAPORATE
BEFORE REACHING THE GROUND. SOME MODEL GUIDANCE SUCH AS LATEST NAM
AND HRRR STILL SHOW A COUPLE HUNDRETHS OF QPF OVER THE EXTREME NRN
PART OF OUR AREA SO CURRENT CHC POPS WILL BE LEFT IN PLACE FOR NOW.
FOR THE DAY THURSDAY...THE SHRTWV TROF WILL MOVE AWAY AND SMWHT
MILDER AIR WILL FOLLOW IN ITS WAKE. SOME LOW OR MID-LEVEL CLOUDS MAY
PERSIST THIS MORNING BUT SHOULD DECREASE OR CLEAR OUT BY AFTERNOON
ESPECIALLY FROM PHL SWD. WITH WARMER AIR MOVING IN AT 850 HPA...MAX
AFTN TEMPS SHOULD BE GENLY 10 TO 15 DEGS WARMER THAN ON WEDNESDAY.
SFC HIGH PRES OVER THE SERN US WILL MOVE EAST OVER THE ATLANTIC
ALLOWING A SWLY TO DEVELOP OVER THE MID-ATLANTIC REGION.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
RIDGING ALOFT WILL CONTINUE OVER THE AREA TONIGHT AS LOW-LEVEL WARM
ADVCTN IS MAINTAINED ON WLY/SWLY WINDS. SKIES SHOULD BE MAINLY CLEAR
SOUTH TO PARTLY CLOUDY NORTH BUT SFC WINDS AND A WARMER AIR MASS
SHOULD RESULT IN OVERNIGHT MIN TEMPS AGAIN 10 TO 15 DEGS WARMER THAN
EARLY TODAY.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
FRIDAY IS EXPECTED TO BE DRY AS HIGH PRESSURE MOVES AWAY FROM THE
AREA. THE NEXT SYSTEM WILL ALREADY BE SPREADING MOISTURE ACROSS THE
AREA...SO ANY MORNING SUN...WILL FADE THROUGH THE AFTERNOON. THE
BEST CHC FOR SUNNY/PARTLY SUNNY WILL BE FOUND ACROSS THE NRN AREAS.
TEMPERATURES FRI WILL REMAIN MILD FOR MID JANUARY WITH LOW 50S
ACROSS THE DEL VALLEY AND S/E WHILE MID TO UPPER 40S WILL BE N/W.
A WET WEATHER SYSTEM...DEEP LOW PRESSURE...WILL BE MOVING WELL
OFFSHORE FRI NIGHT THROUGH SATURDAY. WE WILL BE CLOSE ENOUGH TO GET
A DECENT 12 HOURS OF RAIN AND POSSIBLY A FEW (HIGHEST ELEVATION N/W)
FLAKES. THE MODELS HAVE NARROWED THE SOLUTIONS WITH REGARDS TO THE
SYSTEM...AND ARE KEEPING THE STRONGEST WINDS AND HEAVY PRECIP OFF TO
OUR S/E. STILL 1/2 TO 3/4 INCH OF RAIN POSSIBLE WITH AMTS LESS THAN
1/4 INCH FAR N/W FROM THE SYSTEM. MILD TEMPERATURES WILL CONTINUE
SAT AND INTO SUNDAY. A COLD FRONT WILL CROSS THE AREA SUN...SO WE
WILL MAINTAIN A MENTION OF SOME SCT -RA...WITH SOME CHANGE TO -SN AS
THE COLDER AIR ARRIVES. HIGHS ON SAT WILL BE MOSTLY IN THE 40S...WHILE
READINGS ON SUNDAY WILL MOSTLY BE IN THE 30S.
COLDER BUT MOSTLY DRY WEATHER IS EXPECTED EARLY NEXT WEEK. STRONG
HIGH PRESSURE WILL MOVE OUT OF CANADA AND INTO THE PLAINS. HIGHS MON-
WED WILL MOSTLY BE IN THE 20S N/W AND LOW OR MID 30S S/E. EXCEPT FOR
SOME SNOW SHOWERS WITH A SHORT WAVE SUN NIGHT INTO EARLY MONDAY...THE
PERIOD SHOULD BE DRY. BREEZY/WINDS MONDAY INTO TUE MORNING WITH WIND
CHILL VALUES SINGLE DIGITS N/W AND TEENS ELSEWHERE.
&&
.AVIATION /10Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY, AND SURROUNDING AREAS.
VFR CONDS ARE NOTED AT ALL TAF SITES EARLY THIS MORNING...AND SHOULD
CONTNUE FOR TODAY THROUGH TONIGHT. A BRIEF SNOW FLURRY OR SHOWER IS
POSSIBLE EARLY THIS MORNING AT ABE OR RDG BUT NO SGFNT IMPACT ON CIG
OR VSBY IS EXPECTED. WINDS LATE THIS MORNING WILL INCREASE OUT OF
THE SW AND MAY BE GUST AT TIMES TO 15-20 KT THROUGH MID AFTN. THIS
IS DUE TO DOWNWARD MIXING OF MOMENTUM FROM WINDS A COUPLE THOUSAND
FT ABOVE THE SFC.
OUTLOOK...
FRI...VFR WITH INCREASING CLOUDS.
FRI NIGHT THRU SAT MORNING...MVFR/IFR WITH LOW CIGS AND RAIN.
SAT AFTERNOON THRU SUN NIGHT...MOSTLY VFR. SCT SNOW SHOWERS WITH
MVFR POSSIBLE SUN NIGHT.
MON...VFR. GUSTY W/NW WINDS.
&&
.MARINE...
A SMALL CRAFT ADVISORY CONTNUES IN EFFECT FOR NJ COASTAL WATERS.
WINDS AT NEW YORK HARBOR BUOY 44065 ARE STILL GUSTIG TO AROUND 25
KT. WINDS FARTHER SOUTH ALONG THE NJ WATERS SEEM TO BE LESS BUT ARE
EXPECTED TO INCREASE AGAIN DURING THE DAY TODAY. THUS THE SCA IS
LEFT IN PLACE FOR NOW. WITH OFFSHORE SW FLOW THE SEAS SHOULD REMAIN
UNDER 5 FT.
OUTLOOK...
FRI/FRI NIGHT...MOSTLY SUB SCA CONDITIONS. RAIN FRI NIGHT.
SAT/SAT NIGHT...MARGINAL SCA GUSTS/SEAS OVER THE NJ/DE COASTAL
WATERS.
SUN...MOSTLY SUB SCA.
SUN NIGHT THRU MON NIGHT...INCREASING WINDS/SEAS SUN NIGHT WITH
SCA AND POSSIBLE LOW-END GALE GUSTS. SCA CONDITIONS EXPECTED MON
NIGHT.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
ANZ450>453.
&&
$$
SYNOPSIS...O`HARA
NEAR TERM...AMC
SHORT TERM...AMC
LONG TERM...O`HARA
AVIATION...AMC/O`HARA
MARINE...AMC/O`HARA
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
357 AM EST THU JAN 14 2016
.SYNOPSIS...
A WEAK UPPER AIR FEATURE WILL CROSS THE AREA THIS MORNING...FOLLOWED
BY HIGH PRESSURE FOR TONIGHT AND FRIDAY. LOW PRESSURE WILL DEVELOP
OFF THE SOUTHEAST U.S. COAST FRIDAY AND MOVE ACROSS OUR OFFSHORE
WATERS FRIDAY NIGHT AND SATURDAY. A COLD FRONT WILL CROSS THE
AREA SUNDAY...FOLLOWED BY HIGH PRESSURE WHICH WILL BUILD IN FOR
MONDAY AND PERSIST INTO THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A MID-LEVEL SHRTWV TROF CONTS TO ROTATE THROUGH BROADLY CYCLONIC
FLOW ALOFT OVER THE AREA. THE TROF APPEARS TO BE MOVG THRU WRN/CNTRL
PA AS OF 08Z AND SHOULD BE OFF THE EAST COAST BY 12Z. RADAR LOOP
SHOWS SOME AREAS OF LIGHT SNOW AHEAD OF THE TROF OVER ERN PA...HWVR
THE LOW-LEVEL AIR MASS IS QUITE DRY SO MOST SNOW SHOULD EVAPORATE
BEFORE REACHING THE GROUND. SOME MODEL GUIDANCE SUCH AS LATEST NAM
AND HRRR STILL SHOW A COUPLE HUNDRETHS OF QPF OVER THE EXTREME NRN
PART OF OUR AREA SO CURRENT CHC POPS WILL BE LEFT IN PLACE FOR NOW.
FOR THE DAY THURSDAY...THE SHRTWV TROF WILL MOVE AWAY AND SMWHT
MILDER AIR WILL FOLLOW IN ITS WAKE. SOME LOW OR MID-LEVEL CLOUDS MAY
PERSIST THIS MORNING BUT SHOULD DECREASE OR CLEAR OUT BY AFTERNOON
ESPECIALLY FROM PHL SWD. WITH WARMER AIR MOVING IN AT 850 HPA...MAX
AFTN TEMPS SHOULD BE GENLY 10 TO 15 DEGS WARMER THAN ON WEDNESDAY.
SFC HIGH PRES OVER THE SERN US WILL MOVE EAST OVER THE ATLANTIC
ALLOWING A SWLY TO DEVELOP OVER THE MID-ATLANTIC REGION.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
RIDGING ALOFT WILL CONTINUE OVER THE AREA TONIGHT AS LOW-LEVEL WARM
ADVCTN IS MAINTAINED ON WLY/SWLY WINDS. SKIES SHOULD BE MAINLY CLEAR
SOUTH TO PARTLY CLOUDY NORTH BUT SFC WINDS AND A WARMER AIR MASS
SHOULD RESULT IN OVERNIGHT MIN TEMPS AGAIN 10 TO 15 DEGS WARMER THAN
EARLY TODAY.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
FRIDAY IS EXPECTED TO BE DRY AS HIGH PRESSURE MOVES AWAY FROM THE
AREA. THE NEXT SYSTEM WILL ALREADY BE SPREADING MOISTURE ACROSS THE
AREA...SO ANY MORNING SUN...WILL FADE THROUGH THE AFTERNOON. THE
BEST CHC FOR SUNNY/PARTLY SUNNY WILL BE FOUND ACROSS THE NRN AREAS.
TEMPERATURES FRI WILL REMAIN MILD FOR MID JANUARY WITH LOW 50S
ACROSS THE DEL VALLEY AND S/E WHILE MID TO UPPER 40S WILL BE N/W.
A WET WEATHER SYSTEM...DEEP LOW PRESSURE...WILL BE MOVING WELL
OFFSHORE FRI NIGHT THROUGH SATURDAY. WE WILL BE CLOSE ENOUGH TO GET
A DECENT 12 HOURS OF RAIN AND POSSIBLY A FEW (HIGHEST ELEVATION N/W)
FLAKES. THE MODELS HAVE NARROWED THE SOLUTIONS WITH REGARDS TO THE
SYSTEM...AND ARE KEEPING THE STRONGEST WINDS AND HEAVY PRECIP OFF TO
OUR S/E. STILL 1/2 TO 3/4 INCH OF RAIN POSSIBLE WITH AMTS LESS THAN
1/4 INCH FAR N/W FROM THE SYSTEM. MILD TEMPERATURES WILL CONTINUE
SAT AND INTO SUNDAY. A COLD FRONT WILL CROSS THE AREA SUN...SO WE
WILL MAINTAIN A MENTION OF SOME SCT -RA...WITH SOME CHANGE TO -SN AS
THE COLDER AIR ARRIVES. HIGHS ON SAT WILL BE MOSTLY IN THE 40S...WHILE
READINGS ON SUNDAY WILL MOSTLY BE IN THE 30S.
COLDER BUT MOSTLY DRY WEATHER IS EXPECTED EARLY NEXT WEEK. STRONG
HIGH PRESSURE WILL MOVE OUT OF CANADA AND INTO THE PLAINS. HIGHS MON-
WED WILL MOSTLY BE IN THE 20S N/W AND LOW OR MID 30S S/E. EXCEPT FOR
SOME SNOW SHOWERS WITH A SHORT WAVE SUN NIGHT INTO EARLY MONDAY...THE
PERIOD SHOULD BE DRY. BREEZY/WINDS MONDAY INTO TUE MORNING WITH WIND
CHILL VALUES SINGLE DIGITS N/W AND TEENS ELSEWHERE.
&&
.AVIATION /09Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY, AND SURROUNDING AREAS.
VFR CONDS ARE NOTED AT ALL TAF SITES EARLY THIS MORNING...AND SHOULD
CONTNUE FOR TODAY THROUGH TONIGHT. A BRIEF SNOW FLURRY OR SHOWER IS
POSSIBLE EARLY THIS MORNING AT ABE OR RDG BUT NO SGFNT IMPACT ON CIG
OR VSBY IS EXPECTED. WINDS LATE THIS MORNING WILL INCREASE OUT OF
THE SW AND MAY BE GUST AT TIMES TO 15-20 KT THROUGH MID AFTN. THIS
IS DUE TO DOWNWARD MIXING OF MOMENTUM FROM WINDS A COUPLE THOUSAND
FT ABOVE THE SFC.
OUTLOOK...
FRI...VFR WITH INCREASING CLOUDS.
FRI NIGHT THRU SAT MORNING...MVFR/IFR WITH LOW CIGS AND RAIN.
SAT AFTERNOON THRU SUN NIGHT...MOSTLY VFR. SCT SNOW SHOWERS WITH
MVFR POSSIBLE SUN NIGHT.
MON...VFR. GUSTY W/NW WINDS.
&&
.MARINE...
A SMALL CRAFT ADVISORY CONTNUES IN EFFECT FOR NJ COASTAL WATERS.
WINDS AT NEW YORK HARBOR BUOY 44065 ARE STILL GUSTIG TO AROUND 25
KT. WINDS FARTHER SOUTH ALONG THE NJ WATERS SEEM TO BE LESS BUT ARE
EXPECTED TO INCREASE AGAIN DURING THE DAY TODAY. THUS THE SCA IS
LEFT IN PLACE FOR NOW. WITH OFFSHORE SW FLOW THE SEAS SHOULD REMAIN
UNDER 5 FT.
OUTLOOK...
FRI/FRI NIGHT...MOSTLY SUB SCA CONDITIONS. RAIN FRI NIGHT.
SAT/SAT NIGHT...MARGINAL SCA GUSTS/SEAS OVER THE NJ/DE COASTAL
WATERS.
SUN...MOSTLY SUB SCA.
SUN NIGHT THRU MON NIGHT...INCREASING WINDS/SEAS SUN NIGHT WITH
SCA AND POSSIBLE LOW-END GALE GUSTS. SCA CONDITIONS EXPECTED MON
NIGHT.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
ANZ450>453.
&&
$$
SYNOPSIS...O`HARA
NEAR TERM...AMC
SHORT TERM...AMC
LONG TERM...O`HARA
AVIATION...AMC/O`HARA
MARINE...AMC/O`HARA
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
954 PM EST FRI JAN 15 2016
...AREAS OF DENSE FOG POSSIBLE OVERNIGHT INTO EARLY SATURDAY...
...POTENTIAL FOR ANOTHER ROUND OF SEVERE THUNDERSTORMS LATE
SATURDAY NIGHT INTO SUNDAY MORNING...
.UPDATE (REST OF TONIGHT THROUGH SUNDAY MORNING)...
02Z WATER VAPOR AND H4 RAP ANALYSIS SHOW THE SHORTWAVE THAT
BROUGHT THE ROUND OF THUNDERSTORMS TO THE REGION EARLY FRIDAY IS
NOW RAPIDLY MOVING AWAY UP THE EASTERN SEABOARD. UPPER LEVEL FLOW
IN THE WAKE OF THIS SYSTEM FLATTENS OUT AND BECOMES MORE ZONAL IN
NATURE ACROSS THE GULF OF MEXICO. THIS MORE ZONAL FLOW PATTERN
WILL DEFINE OUR LOCAL WEATHER THROUGH SATURDAY AFTERNOON. MUCH
DRIER AIR AND DEEP LAYER SUBSIDENCE IN THE WAKE OF THE FRIDAY
MORNING SYSTEM HAS ALLOWED OUR SKIES TO GENERALLY CLEAR
OUT...OTHER THAN SOME THIN UPPER LEVEL CIRRUS ASSOCIATED WITH A
STRONG SOUTHERN STREAM JET. THE DRIER AIR ALOFT AND OVERALL
SUPPRESSION OVER TOP THE WET GROUND AND LOW LEVEL MOISTURE FROM
THE EARLIER RAINFALL SHOULD SET THE STAGE FOR AREAS OF FOG
FORMATION OVERNIGHT. ALREADY SEEING SOME PATCHY FOG LATE THIS
EVENING...AND WOULD EXPECT THIS TO ONLY INCREASE IN COVERAGE AND
THICKNESS OVERNIGHT. TOO EARLY TO DETERMINE IF DENSE FOG
ADVISORIES MAY BE NEEDED FOR SOME AREA...BUT THE SITUATION WILL
NEED TO BE MONITORED CLOSELY.
ANY EARLY MORNING FOG IS GONE BY AROUND 9-10AM...SETTING UP A
FAIR...DRY...AND GENERALLY PLEASANT DAY FOR SATURDAY.
TEMPERATURES WILL BE WARM AS HIGHS REACH UP INTO THE LOWER 70S
NORTH AND MIDDLE 70S ELSEWHERE. TEMPS MAY DROP BACK A FEW DEGREES
DURING THE SECOND HALF OF THE AFTERNOON AT THE COAST AS LIGHT WINDS
TURN AT LEAST PARTIALLY ONSHORE OFF THE RELATIVELY COOLER SHELF
WATERS. WILL CALL IT A MIX OF SUN AND CLOUDS...ALTHOUGH UPPER
LEVEL HIGH CLOUDS SHOULD BE THICKENING THE FURTHER INTO THE DAY WE
PROGRESS.
WHILE WE ENJOY QUIET WEATHER DURING THE DAYLIGHT HOURS OF
SATURDAY...BIG CHANGES TO THE PATTERN WILL BE TAKING PLACE TO OUR
WEST OVER THE GULF OF MEXICO. THERE IS NOW GOOD MODEL AGREEMENT IN
A POTENT UPPER LEVEL SHORTWAVE DIGGING INTO THE WESTERN GULF
DURING SATURDAY AFTERNOON/EVENING...AND TRIGGERING AN AREA OF
SURFACE CYCLOGENESIS TO THE SOUTH OF THE LOUISIANA COAST. THIS
STRONG MID/UPPER LEVEL ENERGY AND ASSOCIATED SURFACE LOW WILL THEN
VERY RAPIDLY EJECT EASTWARD ACROSS THE GULF TOWARD THE STATE OF
FLORIDA. WHAT STARTS OUT AS A QUIET BUT INCREASINGLY BREEZY NIGHT
ALONG THE WEST COAST OF FLORIDA...IS LIKELY TO END WITH A ROUND OF
STRONG TO POTENTIALLY SEVERE THUNDERSTORMS APPROACHING THE COAST
DURING THE PRE-DAWN HOURS. AS IT LOOKS NOW...THE BEST TIMING FOR
THUNDERSTORMS TO CROSS THE FORECAST AREA FROM WEST TO EAST WILL
BE ROUGHLY 3AM TO 10 AM SUNDAY.
CONDITIONS CERTAINLY APPEAR FAVORABLE FOR ISOLATED SEVERE WEATHER
TO ACCOMPANY THE PASSAGE OF THIS SYSTEM AND ITS COLD FRONT. AS IT
APPEARS NOW...THE BETTER CHANCES FOR SEVERE WEATHER WILL BE
ROUGHLY ALONG AND SOUTH OF THE I-4 CORRIDOR...WHERE THERE IS A
HIGHER POTENTIAL FOR SOME INSTABILITY AT THE SURFACE. AREAS
FURTHER NORTH...HOWEVER...SHOULD NOT LET THEIR GUARD DOWN JUST
YET...AS THE SEVERE POTENTIAL MAY STILL EXPAND NORTH WITH FUTURE
NWP GUIDANCE. AS IS OFTEN THE CASE WITH WINTER SYSTEMS IN
FLORIDA...THE THERMODYNAMIC FIELDS ARE MARGINAL OR LACKING...BUT
THE KINEMATIC FIELDS ARE VERY IMPRESSIVE. THE LOW LEVEL JET WITH
THIS SYSTEM FROM THE GFS/ECMWF IS 50-60+ KNOTS. THIS LOW LEVEL AND
ANOTHER MID LEVEL JET RESULT IN VERY IMPRESSIVE 0-6KM BULK SHEAR
OF 60+ KNOTS...AND 0-1KM BULK SHEAR OF 35-40+ KNOTS. BOTH VALUES
ARE VERY IMPRESSIVE FOR THIS PART OF THE COUNTRY. HODOGRAPHS IN
THE FEW HOURS SURROUNDING DAWN ACROSS THE REGION SPEAK FOR
THEMSELVES IN TERMS OF FAVORABILITY TOWARD ROTATING STORMS. ONCE
AGAIN...THE IMPRESSIVE WIND FIELDS ARE STILL CONDITIONAL ON LOW
LEVEL INSTABILITY TO ALLOW THE MIXING OF MOMENTUM AND/OR VORTICITY
DOWN TO THE SURFACE. HOWEVER...GIVEN THE FEATURES MENTIONED
ABOVE...AND THE POTENTIAL FOR AT LEAST SOME INSTABILITY OVER THE
CENTRAL AND SOUTHERN PARTS OF THE AREA...THE SITUATION REQUIRES
CLOSE MONITORING THROUGH THE NEXT 24-36 HOURS.
&&
.AVIATION...
AREAS TO WIDESPREAD FOG IS EXPECTED TO DEVELOP ACROSS WEST-CENTRAL
AND SOUTHWEST FLORIDA OVERNIGHT. ALREADY SEEING SOME PATCHY FOG
DEVELOP THIS LATE EVENING AND COVERAGE AND RESTRICTIONS SHOULD
CONTINUE TO INCREASE. HIGHEST POTENTIAL FOR A PERIOD OF IFR OR
LOWER VIS WILL BE FOR KLAL/KPGD/KFMY/KRSW. CURRENTLY HAVE MVFR VIS
FOR TAMPA BAY TERMINALS...AND WILL MONITOR OR NEEDED AMENDMENTS.
FOG WILL LINGER THROUGH THE FIRST FEW DAYLIGHT HOURS BEFORE
LIFTING. AFTER 14-15Z EXPECT VFR CONDITIONS THE REST OF SATURDAY.
&&
.MARINE...
WINDS AND SEAS CONTINUE TO SUBSIDE ACROSS THE FORECAST WATERS.
WINDS HAVE SUBSIDED BELOW ADVISORY LEVELS...BUT RESIDUAL WAVES
WILL NOT FALL BELOW ADVISORY LEVELS UNTIL EARLY SUNDAY MORNING.
WINDS AND WAVES ARE EXPECTED TO REMAIN BELOW HEADLINE CRITERIA
DURING THE DAYLIGHT HOURS SATURDAY...BUT WILL THEN RAMP UP
QUICKLY ONCE AGAIN SATURDAY NIGHT AS YET ANOTHER STRONG STORM
SYSTEM APPROACHES THE AREA FROM THE WEST. WIDESPREAD ADVISORY
LEVEL CONDITIONS ARE EXPECTED SATURDAY NIGHT INTO SUNDAY WITH THE
PASSAGE OF THIS SYSTEM. THE POTENTIAL EXISTS FOR A ROUND OF
STRONG TO SEVERE THUNDERSTORMS LATE SATURDAY NIGHT AND EARLY
SUNDAY MORNING ACROSS THE MARINE AREA AS WELL.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 62 74 65 69 / 0 0 80 80
FMY 61 77 67 74 / 0 0 70 80
GIF 58 77 63 69 / 0 0 70 80
SRQ 63 72 66 70 / 0 0 80 80
BKV 57 76 63 68 / 0 10 80 80
SPG 61 74 63 68 / 0 0 80 80
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...BEACH HAZARDS STATEMENT THROUGH SUNDAY EVENING FOR COASTAL
MANATEE-COASTAL SARASOTA.
HIGH RIP CURRENT RISK THROUGH SATURDAY MORNING FOR COASTAL
CHARLOTTE-COASTAL HILLSBOROUGH-COASTAL LEE-COASTAL
MANATEE-COASTAL SARASOTA-PINELLAS.
GULF WATERS...SMALL CRAFT ADVISORY UNTIL 4 AM EST SATURDAY FOR WATERS
FROM BONITA BEACH TO ENGLEWOOD FL OUT 20 TO 60 NM-
WATERS FROM ENGLEWOOD TO TARPON SPRINGS FL OUT 20 TO
60 NM-WATERS FROM TARPON SPRINGS TO SUWANNEE RIVER FL
OUT 20 TO 60 NM.
&&
$$
UPDATE/AVIATION/MARINE...14/MROCZKA
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
907 PM CST FRI JAN 15 2016
.UPDATE...
ISSUED AT 900 PM CST FRI JAN 15 2016
Freezing drizzle has preceded the band of light snow showers that
have been progressing across our northern counties. Freezing
drizzle is no longer showing up on radar, as it is progressing
farther away to the east. It may last for another hour or so in
our eastern counties before the snow showers arrive from the west.
Upstream reports from western Illinois were that a dusting of snow
was accumulating on surfaces. So we updated to increase PoPs for
light snow and changed the flurries to snow showers for this
evening. Freezing drizzle was also added across eastern counties,
generally along and north of I-74. The snow showers are steadily
progressing to the east, and should reach the Indiana border
between midnight and 1 am. Slippery conditions will be possible
during that time as air temperatures continue to drop below
freezing. Low temps still look on track, with mid-teens near
Galesburg and mid-20s south of I-70.
Gusty northwest winds to 25 mph will continue as pressure rises
remain in the 3-4 mb/3hr range through at least midnight. Have
increased winds and gusts in the grids for the rest of the night.
Clouds will remain entrenched across IL through Saturday morning,
and possibly into the afternoon. No changes needed there.
Updated forecast info is already available.
&&
.SHORT TERM...(Tonight)
ISSUED AT 228 PM CST FRI JAN 15 2016
20z/2pm surface analysis shows cold front pushing east of the I-57
corridor, as the area of rain ahead of the boundary exits into
Indiana. While temperatures are still in the lower to middle 40s
across the E/SE KILX CWA, readings have dropped into the lower to
middle 30s further west across the remainder of the area.
Temperatures will continue to fall over the next couple of hours,
with readings ranging from the upper 20s in the Illinois River
Valley...to the upper 30s across the far SE around Lawrenceville by
early evening. Latest satellite imagery shows plenty of clouds
upstream across central/eastern Iowa, with the closest appreciable
clearing over western sections of Minnesota/Iowa. HRRR shows this
clear spot shifting southeastward and remaining W/SW of the CWA
tonight. Further north, HRRR is hinting that some breaks in the
overcast will develop across Wisconsin later tonight: however, any
clearing from the north will likely not occur until Saturday
morning. As a result, am going with a cloudy forecast tonight, with
a few flurries possible along/north of I-72 during the evening.
Overnight low temperatures will range from the teens northwest of
the Illinois River to the upper 20s southeast of I-70.
.LONG TERM...(Saturday through Friday)
ISSUED AT 228 PM CST FRI JAN 15 2016
Large high pressure ridge will move into the area and affect the CWA
beginning tomorrow. However, a clipper system will move toward the
area tomorrow evening and then into the CWA late tomorrow night. The
snow will push into the northwest parts of the CWA and then spread
east southeast across the remainder of the CWA Sunday morning. If
any area of the CWA does not get snow, it will be in southeast IL.
Northwest winds will be a tad breezy on Sunday as this clipper
system pushes east and out of the area. Dry weather is then expected
through Mon night with cold high pressure dominating the weather
pattern at the end of the weekend and into the beginning of next
week.
Temps will become very cold this weekend as the cold air associated
with the high pressure pours into the area this weekend. Temps will
drop into the single digits along and northwest of the IL river for
Sat night, with wind chills in the range of -10 to -15, which is
close to wind chill advisory. Temps will get much colder Sun night
into Mon morning, with low temps in the single digits in southeast
IL and below zero over the remainder of the CWA, north of I-70.
Combined with the wind, resulting wind chills Sun night will range
from 15 to 25 degrees below zero over most of the area...which is
wind chill advisory criteria.
Another clipper-type weather system will move across the area Tue
thru Wed and produce another round of light snow in the area. Models
differ on speed/timing of this system but appears that most of the
snow will be on Tue night and Wed. After this system moves through,
ECMWF and GFS agree that any additional systems will get pushed
further south leaving the CWA dry from Wed night through Fri.
However, the Canadian model brings another clipper system through
the area mid week with more snow, which agreed with some older model
runs. Blend of the models gives more chance pops, but prefer better
agreement of the ECMWF and GFS. So for now, will just lower pops to
slight chance for Wed night thru Fri; though thinking is that a dry
forecast is what will be seen in later forecasts.
Temps will start cold with Mon night temps remaining well below
normal. Then temps gradually warm back up but not reaching normal
through end of the week. Extended model guidance does not look that
bad, but kept a degree or two below guidance for now.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
ISSUED AT 553 PM CST FRI JAN 15 2016
Cold front has departed to the east of Illinois, with a mix of
MVFR and IFR clouds still poised to affect central Illinois this
evening. A trailing surface trough is rotating into our forecast
area from the NW, producing spotty snow showers/flurries. Have
included -SN for the northern terminals of PIA, BMI and CMI this
evening. Otherwise, no other precip is expected over the next 24
hours.
HRRR and RAP output indicate some clearing may develop
from north to south on Saturday morning, but the NAM soundings are
much more pessimistic with IFR/MVFR clouds through the entire TAF
period. Will lean toward some clearing developing late tomorrow
morning or early afternoon.
Winds will be gusty from the WNW for a few more hours this
evening, as a trailing trough axis rotates through Illinois. Some
gusts could reach 23-25kt until 02-03z. Sustained winds will hover
in the 15-16kt range until 06z, then they should diminish later
tonight to 10-12kt.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...Shimon
SHORT TERM...Barnes
LONG TERM...Auten
AVIATION...Shimon
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
553 PM CST FRI JAN 15 2016
.SHORT TERM...(Tonight)
ISSUED AT 228 PM CST FRI JAN 15 2016
20z/2pm surface analysis shows cold front pushing east of the I-57
corridor, as the area of rain ahead of the boundary exits into
Indiana. While temperatures are still in the lower to middle 40s
across the E/SE KILX CWA, readings have dropped into the lower to
middle 30s further west across the remainder of the area.
Temperatures will continue to fall over the next couple of hours,
with readings ranging from the upper 20s in the Illinois River
Valley...to the upper 30s across the far SE around Lawrenceville by
early evening. Latest satellite imagery shows plenty of clouds
upstream across central/eastern Iowa, with the closest appreciable
clearing over western sections of Minnesota/Iowa. HRRR shows this
clear spot shifting southeastward and remaining W/SW of the CWA
tonight. Further north, HRRR is hinting that some breaks in the
overcast will develop across Wisconsin later tonight: however, any
clearing from the north will likely not occur until Saturday
morning. As a result, am going with a cloudy forecast tonight, with
a few flurries possible along/north of I-72 during the evening.
Overnight low temperatures will range from the teens northwest of
the Illinois River to the upper 20s southeast of I-70.
.LONG TERM...(Saturday through Friday)
ISSUED AT 228 PM CST FRI JAN 15 2016
Large high pressure ridge will move into the area and affect the CWA
beginning tomorrow. However, a clipper system will move toward the
area tomorrow evening and then into the CWA late tomorrow night. The
snow will push into the northwest parts of the CWA and then spread
east southeast across the remainder of the CWA Sunday morning. If
any area of the CWA does not get snow, it will be in southeast IL.
Northwest winds will be a tad breezy on Sunday as this clipper
system pushes east and out of the area. Dry weather is then expected
through Mon night with cold high pressure dominating the weather
pattern at the end of the weekend and into the beginning of next
week.
Temps will become very cold this weekend as the cold air associated
with the high pressure pours into the area this weekend. Temps will
drop into the single digits along and northwest of the IL river for
Sat night, with wind chills in the range of -10 to -15, which is
close to wind chill advisory. Temps will get much colder Sun night
into Mon morning, with low temps in the single digits in southeast
IL and below zero over the remainder of the CWA, north of I-70.
Combined with the wind, resulting wind chills Sun night will range
from 15 to 25 degrees below zero over most of the area...which is
wind chill advisory criteria.
Another clipper-type weather system will move across the area Tue
thru Wed and produce another round of light snow in the area. Models
differ on speed/timing of this system but appears that most of the
snow will be on Tue night and Wed. After this system moves through,
ECMWF and GFS agree that any additional systems will get pushed
further south leaving the CWA dry from Wed night through Fri.
However, the Canadian model brings another clipper system through
the area mid week with more snow, which agreed with some older model
runs. Blend of the models gives more chance pops, but prefer better
agreement of the ECMWF and GFS. So for now, will just lower pops to
slight chance for Wed night thru Fri; though thinking is that a dry
forecast is what will be seen in later forecasts.
Temps will start cold with Mon night temps remaining well below
normal. Then temps gradually warm back up but not reaching normal
through end of the week. Extended model guidance does not look that
bad, but kept a degree or two below guidance for now.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
ISSUED AT 553 PM CST FRI JAN 15 2016
Cold front has departed to the east of Illinois, with a mix of
MVFR and IFR clouds still poised to affect central Illinois this
evening. A trailing surface trough is rotating into our forecast
area from the NW, producing spotty snow showers/flurries. Have
included -SN for the northern terminals of PIA, BMI and CMI this
evening. Otherwise, no other precip is expected over the next 24
hours.
HRRR and RAP output indicate some clearing may develop
from north to south on Saturday morning, but the NAM soundings are
much more pessimistic with IFR/MVFR clouds through the entire TAF
period. Will lean toward some clearing developing late tomorrow
morning or early afternoon.
Winds will be gusty from the WNW for a few more hours this
evening, as a trailing trough axis rotates through Illinois. Some
gusts could reach 23-25kt until 02-03z. Sustained winds will hover
in the 15-16kt range until 06z, then they should diminish later
tonight to 10-12kt.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Barnes
LONG TERM...Auten
AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
948 PM EST FRI JAN 15 2016
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 627 PM EST FRI JAN 15 2016
A COLD FRONT WILL SWEEP ACROSS CENTRAL INDIANA TONIGHT...PUSHING
COOLER...MORE SEASONABLE AIR INTO CENTRAL INDIANA. CLOUDS ARE
EXPECTED TO LINGER ACROSS CENTRAL INDIANA ON SATURDAY AND SUNDAY
AS YET ANOTHER COLD FRONT PASSES ON LATE SATURDAY NIGHT...ALLOWING
TEMPERATURES TO FALL EVEN COLDER.
DRY BUT COLD WEATHER IS EXPECTED AS WE START THE NEXT WORK WEEK.
&&
.NEAR TERM /OVERNIGHT/...
ISSUED AT 930 PM EST FRI JAN 15 2016
RADAR SHOWS A QUICK MOVING AREA OF SNOW SHOWERS OVER NRN ILLINOIS
POISED TO PUSH INTO NRN INDIANA OVERNIGHT AMID THE BROAD CYCLONIC
FLOW WIN THE WAKE OF THE PASSED COLD FRONT. AS HRRR SHOWS SHOWS
THIS DEVELOPMENT OVERNIGHT AND EXTENSIVE CLOUD COVER
CONTINUES...HAVE TRENDED TOWARD CLOUDY SKIES ALONG WITH SLIGHT
CHANCE FOR A SNOW SHOWER...MAINLY NORTH OF I-70. DUE TO LIMITED
MOISTURE AND POOR ORGANIZATION...ANY ACCUMULATION WILL BE LIMITED.
STRONG COLD AIR ADVECTION IS ONGOING AS TEMPS IN THE MID 20S ARE
PREVALENT UPSTREAM. THUS HAVE TRENDED LOW TEMPS A BIT COOLER
PENDING THE ARRIVAL OF THE COLDER AIR.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY/...
ISSUED AT 225 PM EST FRI JAN 15 2016
FOCUS IS ON SNOW CHANCES THEN COLD SUNDAY.
SATURDAY FEATURES HIGH PRESSURE BEFORE ARCTIC FRONT ARRIVAL. WITH
LOTS OF RESIDUAL MOISTURE IN LOW LEVELS...EXPECT CLOUDY SKIES TO
CONTINUE OR PERHAPS ONLY A FEW BREAKS IN THE CLOUDS AT BEST. THUS
VERY LITTLE WARMING SATURDAY AND CURRENT MAX TEMPS IN LOWER 30S
LOOK GOOD. SATURDAY NIGHT AND SUNDAY...MODELS ARE IN PRETTY GOOD
AGREEMENT WITH ARCTIC FRONT APPROACHING BY DAYBREAK SUNDAY.
CURRENT MIN TEMP FORECASTS OF TEENS TO LOWER 20S MAYBE A BIT COLD
SUNDAY MORNING THOUGH WE ARE IN COLD ADVECTION. SOME LIGHT SNOW
TO ACCOMPANY TROUGH PASSAGE SUNDAY FOLLOWED BY SLOWLY FALLING
TEMPS THEN GRADUAL LATE DAY CLEARING. WITH NO SURFACE WAVE TO
SPEAK OF WITH THIS NEW ARCTIC SURGE...FEEL THE NAM QPF IS A BIT
HIGH FOR SYNOPTICS AND AVAILABLE MOISTURE BUT ALSO THINK GFS IS A
TAD LOW ON QPF. THUS SNOW AMOUNTS A HALF INCH OR LESS NORTH AND
TRACE OR DUSTING SOUTH APPEAR BEST.
SUNDAY NIGHT AND MONDAY...SKIES WILL BE CLEAR UNDER THE INFLUENCE
OF HIGH PRESSURE. WIND FLOWS SHOULD KEEP ANY LAKE EFFECT SNOWS
WELL TO THE NORTH. THOUGH THICKNESSES WILL BE SLIGHTLY LOWER THAN
PREVIOUS ARCTIC PUSH AND THOUGH SKIES WILL BE CLEAR...JUST ENOUGH
WIND AND A RELATIVE ABSENCE OF SNOW COVER THIS TIME SHOULD KEEP
MOST LOCATIONS JUST ABOVE ZERO SUNDAY NIGHT AND MONDAY MORNING.
WIND CHILLS WILL BE NEAR 15 BELOW ZERO MONDAY AND AT THRESHOLD
FOR WIND CHILL ADVISORY BUT COUPLE MORE MODEL RUNS MAY CHANGE
NUMBERS SOME. ADVISORY...IF ISSUED...WOULD NOT COME BEFORE
SATURDAY AFTERNOON AT EARLIEST.
MONDAY WILL BE SUNNY AND DRY WITH TEMPERATURES IN THE TEENS...ALONG
GUIDANCE LINES...APPEAR GOOD AND NOT CHANGED.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
ISSUED AT 242 PM EST FRI JAN 15 2016
TEMPERATURES SHOULD GRADUALLY MODERATE MORE TOWARD CLIMATOLOGICAL
NORMALS OR JUST BELOW DURING THE LONG TERM PERIOD...AS FLOW BECOMES
MORE ZONAL AND THE AREA PULLS OUT OF THE ANTICIPATED EARLY WEEK DEEP
FREEZE.
A COUPLE OF WEAK DISTURBANCES ARE DEPICTED BY MODELS MOVING THROUGH
THE REGION MID TO LATE WEEK. HOWEVER...MOISTURE IS LACKING AND
MODELS HAVE TRENDED A BIT DRIER. IN COLLABORATION WITH
NEIGHBORS...HAVE DROPPED POPS IN MANY PERIODS DOWN TO SLIGHT CHANCE
ONLY.
&&
.AVIATION /DISCUSSION FOR THE 160300Z KIND TAF UPDATE/...
ISSUED AT 926 PM EST FRI JAN 15 2016
SOME AREAS OF DRIZZLE IN THE VICINITY OF KIND SHOULD END WITHIN THE
NEXT HOUR OR SO AS UPPER VORTICITY CENTER PUSHES OFF TO THE EAST.
IFR CEILINGS STILL EXTEND BACK INTO EASTERN ILLINOIS...SO WILL KEEP
IFR CEILINGS IN THE FORECAST FOR SEVERAL MORE HOURS.
PREVIOUS DISCUSSION FOLLOWS.
COLD FRONT HAS PASSED THROUGH KLAF/KHUF AT THIS TIME...AND SHOULD
BE CLOSE TO PASSING KBMG/KIND BY ISSUANCE TIME.
WIDESPREAD CEILINGS AROUND 012 EXPECTED TONIGHT. AREAS OF IFR
CEILINGS/VISIBILITY RESTRICTIONS IN LIGHT FOG AND SOME DRIZZLE
PROBABLE AT THE TERMINALS INTO THE LATE EVENING AS UPPER LEVEL
VORTICITY CENTER CURRENTLY OVER NORTHERN ILLINOIS MOVES THROUGH.
SURFACE WINDS GENERALLY 270-290 DEGREES AT 10-13 KTS TONIGHT.
THERE WILL PROBABLY BE SOME SURFACE GUSTS 20-25 KTS AT TIMES THIS
EVENING IN THE WAKE OF COLD FRONT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...PUMA
NEAR TERM...PUMA
SHORT TERM...TUCEK
LONG TERM...NIELD
AVIATION...JAS
AREA FORECAST DISCUSSION
NWS GRAY ME
950 PM EST FRI JAN 15 2016
.SYNOPSIS...
A RIDGE OF HIGH PRESSURE WILL GRADUALLY MOVE OFF TO THE EAST
TONIGHT WHILE LOW PRESSURE DEVELOPS TO OUR WEST. LOW PRESSURE WILL
ALSO DEVELOP OFF THE MID ATLANTIC COAST TONIGHT AND MOVE TOWARD
THE NORTHEAST ON SATURDAY. THIS SYSTEM WILL BRING A WINTRY MIX OF
PRECIPITATION TO THE REGION LATE TONIGHT INTO SATURDAY. THE BEST
CHANCES FOR SEEING ALL SNOW WILL BE AWAY FROM THE COAST AND INTO
THE HIGHER TERRAIN. ANOTHER STORM SYSTEM MAY BRING SNOW TO THE
AREA ON MONDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
UPDATE...
ADDED PRECIP TYPE FOR THE POSSIBILITY OF -FZRA TONIGHT ALONG
COASTAL YORK COUNTY TO BETTER MATCH MIN TEMPERATURE FORECAST AND
SINCE SOME TEMPERATURES WERE BELOW FREEZING EVEN ALONG THE
BEACHES THIS EVENING.
TRACK OF THE SURFACE LOW WILL FOCUS ON LATEST SURFACE
ANALYSIS...RADAR AND SATELLITE TRENDS AS NUMERICAL MODELS CONTINUE
TO STRUGGLE WITH CONSISTENCY WITH THE TRACK OF THIS SYSTEM...EVEN
WITH SOME OF THE SREF MEMBERS.
CONTINUING TO MONITOR LATEST OBSERVATIONS FROM OUR FORECAST AREA
AS WELL AS CONDITIONS OVER THE CAROLINAS THIS EVENING. DECENT
FALL-RISE COUPLET HAS DEVELOPED OVER THE MID ATLANTIC REGION WITH
A SURFACE PRESSURE DOWN TO 991 MB AS OF 02Z. PLENTY OF CONVECTION
OFF CAPE HATTERUS THIS HOUR. IN ADDITION...CONVECTION NOTING THE
CYCLONGENESIS HAS BEEN NOTED ON EVENING WATER VAPOR AND IR
IMAGERY.
FURTHER TO THE NORTH...CONDITIONS REMAIN BELOW FREEZING IN MUCH OF
OUR FORECAST AREA WITH THE EXCEPTION OF SOUTHEAST NEW HAMPSHIRE.
THERE IS REMOVE FOR EVAPORATIONAL COOLING AFTER THE ONSET OF
PRECIPITATION WITH A RELATIVELY DRY SOUNDING IN PLACE AT 00Z AND
SURFACE DEW POINTS CURRENTLY IN THE TEENS TO MID 20S.
DELAY IN THE PRECIP: VERY LIGHT PRECIPITATION WILL LIKELY HOLD OFF
UNTIL ABOUT 05Z OR 06Z PER THE LATEST SUITE OF MESOSCALE MODELS
AND CURRENT OBSERVATIONAL TRENDS. ITS NOT UNTIL AFTER 08Z WHEN
PERHAPS THE PRECIP BECOMES STEADY. THE HEAVIEST PRECIP WILL OCCUR
EARLY TOMORROW MORNING AS THE INTENSIFYING SURFACE LOW PASSES
SOUTHEAST OF NANTUCKET...NEAR THE BENCHMARK. LATEST HRRR SHOWING
SOME BANDING FEATURES ALONG THE COAST OF MAINE/NH AT THAT TIME.
IN ANY CASE...ONLY MINOR MODIFICATIONS TO THE CURRENT GRIDS AT
THIS TIME WHILE WATCHING TEMPERATURE...DEW POINT AND WIND TRENDS.
SO FAR...THE COASTAL FRONT HAS REMAINED MOSTLY OFFSHORE...HOWEVER
WARM AIR MAY BE MOVING INTO CAPE ELIZABETH AREA...AND OTHER
EXPOSED AREAS ALONG THE SOUTHWEST COAST...THE ISLANDS AND PORTIONS
OF THE MIDCOAST THIS EVENING.
MADE SOME MINOR ADJUSTMENTS TO THE SNOWFALL FORECAST FOR
SATURDAY...MOSTLY JUST SMOOTHED THE FORECAST PRODUCT - MAINLY OVER
NEAR THE PENOBSCOT VALLEY REGION.
PREV DISC...
AT 19Z...A RIDGE OF HIGH PRESSURE EXTENDED FROM QUEBEC SOUTHEAST
ACROSS MAINE. THE RIDGE WILL SLIDE OFFSHORE THIS EVENING ALLOWING
BOTH NORTHERN AND SOUTHERN STREAM DISTURBANCES TO APPROACH THE
REGION IN THE PREDAWN HOURS. INITIALLY... WE SHOULD BE COLD ENOUGH
FOR SNOW AS WARM AIR ADVECTION PRECIPITATION DEVELOPS... BEFORE
WARMER AIR COMES IN ALOFT WITH NORTHERN DISTURBANCE.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
FOR SATURDAY... COLD AIR DAMMING AND COASTAL FRONT WILL LIMIT THE
AMOUNT OF SURFACE WARM AIR...ESPECIALLY INLAND ALONG THE COASTAL
PLAIN TO THE LEE OF THE MOUNTAINS. AS WE BRIEFLY WARM ALOFT
AHEAD OF THE NORTHERN DISTURBANCE WE`LL SEE A MIX OF
PRECIPITATION OVER SOUTHERN AND COASTAL SECTIONS... WITH SNOW FOR
THE MOUNTAINS AND FOOTHILLS. THE DEVELOPING SOUTHERN DISTURBANCE
QUICKLY TAKES OVER... WITH COLDER AIR BEING DRAWN BACK SOUTH INTO
THE AREA WITH A TRANSITION BACK TO SNOW AND SLEET FOR EVEN THE
COAST BEFORE PRECIPITATION WINDS DOWN DURING THE AFTERNOON OR
EVENING HOURS. THE MOUNTAINS AND FOOTHILLS WILL SEE THE SNOW
LINGER LONGEST BEFORE TAPERING TO FLURRIES SATURDAY NIGHT. THE
MODEL TREND HAS BEEN TO SHIFT THE HIGHEST QPF FURTHER SOUTH AND
EAST PAST SEVERAL RUNS... SO I EXPECT THE WINTER STORM WATCH AREA
TO SEE TOTALS GENERALLY UNDER 6 INCHES WITH THE WATCH CONVERTED TO
A WINTER WEATHER ADVISORY. ELSEWHERE... IT`LL BE A MIXED BAG WITH
SNOW... SLEET... RAIN... FREEZING RAIN MEDLEY REQUIRING A WINTER
WEATHER ADVISORY AS WELL. I USED NAMDNG IN AN ATTEMPT TO BETTER
REFLECT THE ANTICIPATED COLD AIR DAMNING IN SURFACE TEMPERATURES
TONIGHT AND SATURDAY.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
COLD AIR WILL FILTER IN SUNDAY WHICH WILL ACT GENERALLY AS
A TRANSITION DAY. THE LARGE UPPER LOW OVER SOUTHERN CANADA/THE
NORTHERN PLAINS WILL DIG AND PROGRESS TOWARDS THE NORTHERN
GREAT LAKES REGION. A SOUTHERN STREAM SHORT WAVE WILL MOVE OUT
INTO THE MID ATLANTIC REGION... FOLLOWING THE PATH OF OUR WEEKEND
SYSTEM.
THIS STORM WILL BE WEAKER THAN ITS PREDECESSOR AND COLD AIR
WILL ALREADY BE IN PLACE. THEREFORE A PERIOD OF SNOW SHOWERS
BEGINNING LATE SUNDAY INTO MONDAY ARE FORECAST AT THIS TIME. EVEN
THOUGH QPF WILL BE LIGHT... THE CONCERN IS THAT FORECASTED SNOW-
TO-WATER RATIOS WILL BE HIGH... MAKING FOR DRY FLUFFY SNOW BUT
ALSO BUMPING UP THE AMOUNTS. ON MONDAY A WEAK INVERTED TROUGH WILL
EXTEND FROM THE CYCLONE INLAND TOWARDS WESTERN MAINE AND CENTRAL/
NORTHERN NH. THEREFORE HAVE INCREASED SNOWFALL TOTALS AROUND THIS
FORCING MECHANISM. CURRENTLY THE MAXIMUM SNOWFALL AMOUNTS WOULD BE
IN THE ADVISORY RANGE OVER THE HIGHER TERRAIN.
DURING THIS PERIOD THE ARCTIC OSCILLATION WILL BE AT ITS LOWEST
POINT THIS WINTER... INDICATING VERY COLD ARCTIC AIR WILL CONTINUE
TO DIP INTO THE NORTHEAST. INDEED HIGH TEMPERATURES WILL BE IN THE
TEENS AND 20S... WITH LOWS IN THE SINGLE DIGITS THROUGH THE WORK
WEEK.
BY TUESDAY CLOUDS WILL BEGIN TO CLEAR OUT OVER THE COASTAL
PLAIN. CLOUDS WILL LINGER OVER THE HIGHER TERRAIN AND A STRAY
SNOW SHOWER MAY DEVELOP AS WE WILL BE ON THE WESTERN PERIPHERY OF
THE UPPER LEVEL TROUGH. LONG TERM GUIDANCE IS VERY VOLATILE
BEYOND THIS PERIOD... BUT HIGH PRESSURE MOVING IN AT THE SURFACE
SHOULD KEEP THINGS ON THE DRY SIDE FOR MIDWEEK.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
SHORT TERM...VFR CIGS WILL LOWER TO IFR LATE TONIGHT AND
IFR/LIFR CONDITIONS FOR SAT IN PRECIPITATION. CONDITIONS WILL
GRADUALLY IMPROVE TO VFR SAT NIGHT...WITH SCT MVFR IN MTN -SHSN.
LONG TERM...LATE SUN INTO MON MVFR OR LOWER CONDITIONS ARE LIKELY
IN SHSN ACROSS THE REGION...ESPECIALLY ALONG A BOUNDARY EXTENDING
FROM THE MAINE COAST/NEAR KPWM/ TOWARDS THE NH MOUNTAINS. BEHIND
THE UPPER TROF...WLY FLOW WILL KEEP UPSLOPE SHSN AND SCATTERED
MVFR/IFR CONDITIONS AROUND HIE INTO TUE. OTHERWISE VFR CONDITIONS
EXPECTED.
&&
.MARINE...
SHORT TERM /THROUGH SATURDAY NIGHT/...DEVELOPING OCEAN LOW WILL
MOVE NORTHEAST INTO THE GULF OF MAINE LATE TONIGHT AND SATURDAY
ALLOWING INCREASING WINDS AND SEAS...THUS THE SCA FOR THAT TIME
PERIOD. THE SCA HAS BEEN EXPANDED TO INCLUDE CASCO BAY WITH THIS
FORECAST PACKAGE AS WELL.
LONG TERM...MONDAY THROUGH WEDNESDAY WINDS AND SEAS INCREASE IN
ACCORDANCE WITH PASSING LOW PRESSURE AND AN INCREASING PRESSURE
GRADIENT. SMALL CRAFT ADVISORIES WILL BE NEEDED AND PERHAPS GALES
WILL BE NEEDED AT TIMES FOR THE OUTER WATERS AND PERHAPS THE BAYS.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY FROM 3 AM TO 6 PM EST SATURDAY FOR
MEZ018>028.
WINTER WEATHER ADVISORY FROM 3 AM TO 10 PM EST SATURDAY FOR
MEZ007>009-012>014.
NH...WINTER WEATHER ADVISORY FROM 3 AM TO 6 PM EST SATURDAY FOR
NHZ005-006-009-010.
WINTER WEATHER ADVISORY FROM 3 AM TO 10 PM EST SATURDAY FOR
NHZ001>004.
WINTER WEATHER ADVISORY FROM 1 AM TO 4 PM EST SATURDAY FOR
NHZ007-008-011>015.
MARINE...SMALL CRAFT ADVISORY FROM 2 AM TO 7 PM EST SATURDAY FOR
ANZ150>154.
&&
$$
JC
AREA FORECAST DISCUSSION
NWS GRAY ME
940 PM EST FRI JAN 15 2016
.SYNOPSIS...
A RIDGE OF HIGH PRESSURE WILL GRADUALLY MOVE OFF TO THE EAST
TONIGHT WHILE LOW PRESSURE DEVELOPS TO OUR WEST. LOW PRESSURE WILL
ALSO DEVELOP OFF THE MID ATLANTIC COAST TONIGHT AND MOVE TOWARD
THE NORTHEAST ON SATURDAY. THIS SYSTEM WILL BRING A WINTRY MIX OF
PRECIPITATION TO THE REGION LATE TONIGHT INTO SATURDAY. THE BEST
CHANCES FOR SEEING ALL SNOW WILL BE AWAY FROM THE COAST AND INTO
THE HIGHER TERRAIN. ANOTHER STORM SYSTEM MAY BRING SNOW TO THE
AREA ON MONDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
UPDATE...
TRACK OF THE SURFACE LOW WILL FOCUS ON LATEST SURFACE
ANALYSIS...RADAR AND SATELLITE TRENDS AS NUMERICAL MODELS CONTINUE
TO STRUGGLE WITH CONSISTENCY WITH THE TRACK OF THIS SYSTEM...EVEN
WITH SOME OF THE SREF MEMBERS.
CONTINUING TO MONITOR LATEST OBSERVATIONS FROM OUR FORECAST AREA
AS WELL AS CONDITIONS OVER THE CAROLINAS THIS EVENING. DECENT
FALL-RISE COUPLET HAS DEVELOPED OVER THE MID ATLANTIC REGION WITH
A SURFACE PRESSURE DOWN TO 991 MB AS OF 02Z. PLENTY OF CONVECTION
OFF CAPE HATTERUS THIS HOUR. IN ADDITION...CONVECTION NOTING THE
CYCLONGENESIS HAS BEEN NOTED ON EVENING WATER VAPOR AND IR
IMAGERY.
FURTHER TO THE NORTH...CONDITIONS REMAIN BELOW FREEZING IN MUCH OF
OUR FORECAST AREA WITH THE EXCEPTION OF SOUTHEAST NEW HAMPSHIRE.
THERE IS REMOVE FOR EVAPORATIONAL COOLING AFTER THE ONSET OF
PRECIPITATION WITH A RELATIVELY DRY SOUNDING IN PLACE AT 00Z AND
SURFACE DEW POINTS CURRENTLY IN THE TEENS TO MID 20S.
DELAY IN THE PRECIP: VERY LIGHT PRECIPITATION WILL LIKELY HOLD OFF
UNTIL ABOUT 05Z OR 06Z PER THE LATEST SUITE OF MESOSCALE MODELS
AND CURRENT OBSERVATIONAL TRENDS. ITS NOT UNTIL AFTER 08Z WHEN
PERHAPS THE PRECIP BECOMES STEADY. THE HEAVIEST PRECIP WILL OCCUR
EARLY TOMORROW MORNING AS THE INTENSIFYING SURFACE LOW PASSES
SOUTHEAST OF NANTUCKET...NEAR THE BENCHMARK. LATEST HRRR SHOWING
SOME BANDING FEATURES ALONG THE COAST OF MAINE/NH AT THAT TIME.
IN ANY CASE...ONLY MINOR MODIFICATIONS TO THE CURRENT GRIDS AT
THIS TIME WHILE WATCHING TEMPERATURE...DEW POINT AND WIND TRENDS.
SO FAR...THE COASTAL FRONT HAS REMAINED MOSTLY OFFSHORE...HOWEVER
WARM AIR MAY BE MOVING INTO CAPE ELIZABETH AREA...AND OTHER
EXPOSED AREAS ALONG THE SOUTHWEST COAST...THE ISLANDS AND PORTIONS
OF THE MIDCOAST THIS EVENING.
MADE SOME MINOR ADJUSTMENTS TO THE SNOWFALL FORECAST FOR
SATURDAY...MOSTLY JUST SMOOTHED THE FORECAST PRODUCT - MAINLY OVER
NEAR THE PENOBSCOT VALLEY REGION.
PREV DISC...
AT 19Z...A RIDGE OF HIGH PRESSURE EXTENDED FROM QUEBEC SOUTHEAST
ACROSS MAINE. THE RIDGE WILL SLIDE OFFSHORE THIS EVENING ALLOWING
BOTH NORTHERN AND SOUTHERN STREAM DISTURBANCES TO APPROACH THE
REGION IN THE PREDAWN HOURS. INITIALLY... WE SHOULD BE COLD ENOUGH
FOR SNOW AS WARM AIR ADVECTION PRECIPITATION DEVELOPS... BEFORE
WARMER AIR COMES IN ALOFT WITH NORTHERN DISTURBANCE.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
FOR SATURDAY... COLD AIR DAMMING AND COASTAL FRONT WILL LIMIT THE
AMOUNT OF SURFACE WARM AIR...ESPECIALLY INLAND ALONG THE COASTAL
PLAIN TO THE LEE OF THE MOUNTAINS. AS WE BRIEFLY WARM ALOFT
AHEAD OF THE NORTHERN DISTURBANCE WE`LL SEE A MIX OF
PRECIPITATION OVER SOUTHERN AND COASTAL SECTIONS... WITH SNOW FOR
THE MOUNTAINS AND FOOTHILLS. THE DEVELOPING SOUTHERN DISTURBANCE
QUICKLY TAKES OVER... WITH COLDER AIR BEING DRAWN BACK SOUTH INTO
THE AREA WITH A TRANSITION BACK TO SNOW AND SLEET FOR EVEN THE
COAST BEFORE PRECIPITATION WINDS DOWN DURING THE AFTERNOON OR
EVENING HOURS. THE MOUNTAINS AND FOOTHILLS WILL SEE THE SNOW
LINGER LONGEST BEFORE TAPERING TO FLURRIES SATURDAY NIGHT. THE
MODEL TREND HAS BEEN TO SHIFT THE HIGHEST QPF FURTHER SOUTH AND
EAST PAST SEVERAL RUNS... SO I EXPECT THE WINTER STORM WATCH AREA
TO SEE TOTALS GENERALLY UNDER 6 INCHES WITH THE WATCH CONVERTED TO
A WINTER WEATHER ADVISORY. ELSEWHERE... IT`LL BE A MIXED BAG WITH
SNOW... SLEET... RAIN... FREEZING RAIN MEDLEY REQUIRING A WINTER
WEATHER ADVISORY AS WELL. I USED NAMDNG IN AN ATTEMPT TO BETTER
REFLECT THE ANTICIPATED COLD AIR DAMNING IN SURFACE TEMPERATURES
TONIGHT AND SATURDAY.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
COLD AIR WILL FILTER IN SUNDAY WHICH WILL ACT GENERALLY AS
A TRANSITION DAY. THE LARGE UPPER LOW OVER SOUTHERN CANADA/THE
NORTHERN PLAINS WILL DIG AND PROGRESS TOWARDS THE NORTHERN
GREAT LAKES REGION. A SOUTHERN STREAM SHORT WAVE WILL MOVE OUT
INTO THE MID ATLANTIC REGION... FOLLOWING THE PATH OF OUR WEEKEND
SYSTEM.
THIS STORM WILL BE WEAKER THAN ITS PREDECESSOR AND COLD AIR
WILL ALREADY BE IN PLACE. THEREFORE A PERIOD OF SNOW SHOWERS
BEGINNING LATE SUNDAY INTO MONDAY ARE FORECAST AT THIS TIME. EVEN
THOUGH QPF WILL BE LIGHT... THE CONCERN IS THAT FORECASTED SNOW-
TO-WATER RATIOS WILL BE HIGH... MAKING FOR DRY FLUFFY SNOW BUT
ALSO BUMPING UP THE AMOUNTS. ON MONDAY A WEAK INVERTED TROUGH WILL
EXTEND FROM THE CYCLONE INLAND TOWARDS WESTERN MAINE AND CENTRAL/
NORTHERN NH. THEREFORE HAVE INCREASED SNOWFALL TOTALS AROUND THIS
FORCING MECHANISM. CURRENTLY THE MAXIMUM SNOWFALL AMOUNTS WOULD BE
IN THE ADVISORY RANGE OVER THE HIGHER TERRAIN.
DURING THIS PERIOD THE ARCTIC OSCILLATION WILL BE AT ITS LOWEST
POINT THIS WINTER... INDICATING VERY COLD ARCTIC AIR WILL CONTINUE
TO DIP INTO THE NORTHEAST. INDEED HIGH TEMPERATURES WILL BE IN THE
TEENS AND 20S... WITH LOWS IN THE SINGLE DIGITS THROUGH THE WORK
WEEK.
BY TUESDAY CLOUDS WILL BEGIN TO CLEAR OUT OVER THE COASTAL
PLAIN. CLOUDS WILL LINGER OVER THE HIGHER TERRAIN AND A STRAY
SNOW SHOWER MAY DEVELOP AS WE WILL BE ON THE WESTERN PERIPHERY OF
THE UPPER LEVEL TROUGH. LONG TERM GUIDANCE IS VERY VOLATILE
BEYOND THIS PERIOD... BUT HIGH PRESSURE MOVING IN AT THE SURFACE
SHOULD KEEP THINGS ON THE DRY SIDE FOR MIDWEEK.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
SHORT TERM...VFR CIGS WILL LOWER TO IFR LATE TONIGHT AND
IFR/LIFR CONDITIONS FOR SAT IN PRECIPITATION. CONDITIONS WILL
GRADUALLY IMPROVE TO VFR SAT NIGHT...WITH SCT MVFR IN MTN -SHSN.
LONG TERM...LATE SUN INTO MON MVFR OR LOWER CONDITIONS ARE LIKELY
IN SHSN ACROSS THE REGION...ESPECIALLY ALONG A BOUNDARY EXTENDING
FROM THE MAINE COAST/NEAR KPWM/ TOWARDS THE NH MOUNTAINS. BEHIND
THE UPPER TROF...WLY FLOW WILL KEEP UPSLOPE SHSN AND SCATTERED
MVFR/IFR CONDITIONS AROUND HIE INTO TUE. OTHERWISE VFR CONDITIONS
EXPECTED.
&&
.MARINE...
SHORT TERM /THROUGH SATURDAY NIGHT/...DEVELOPING OCEAN LOW WILL
MOVE NORTHEAST INTO THE GULF OF MAINE LATE TONIGHT AND SATURDAY
ALLOWING INCREASING WINDS AND SEAS...THUS THE SCA FOR THAT TIME
PERIOD. THE SCA HAS BEEN EXPANDED TO INCLUDE CASCO BAY WITH THIS
FORECAST PACKAGE AS WELL.
LONG TERM...MONDAY THROUGH WEDNESDAY WINDS AND SEAS INCREASE IN
ACCORDANCE WITH PASSING LOW PRESSURE AND AN INCREASING PRESSURE
GRADIENT. SMALL CRAFT ADVISORIES WILL BE NEEDED AND PERHAPS GALES
WILL BE NEEDED AT TIMES FOR THE OUTER WATERS AND PERHAPS THE BAYS.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY FROM 3 AM TO 6 PM EST SATURDAY FOR
MEZ018>028.
WINTER WEATHER ADVISORY FROM 3 AM TO 10 PM EST SATURDAY FOR
MEZ007>009-012>014.
NH...WINTER WEATHER ADVISORY FROM 3 AM TO 6 PM EST SATURDAY FOR
NHZ005-006-009-010.
WINTER WEATHER ADVISORY FROM 3 AM TO 10 PM EST SATURDAY FOR
NHZ001>004.
WINTER WEATHER ADVISORY FROM 1 AM TO 4 PM EST SATURDAY FOR
NHZ007-008-011>015.
MARINE...SMALL CRAFT ADVISORY FROM 2 AM TO 7 PM EST SATURDAY FOR
ANZ150>154.
&&
$$
JC
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
328 PM EST THU JAN 14 2016
LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM/MARINE
.SYNOPSIS...
ISSUED AT 258 PM EST THU JAN 14 2016
ONE LOW PRESSURE SYSTEM IN IOWA WILL TRACK EAST TONIGHT AND
THROUGH MICHIGAN ON FRIDAY. THIS SYSTEM COULD PRODUCE SOME LIGHT
RAIN. A COLDER AIRMASS RETURNS TO THE REGION FRIDAY NIGHT INTO
SATURDAY WITH LAKE EFFECT SNOW SHOWERS POSSIBLE NEAR THE
LAKESHORE. A REINFORCING SHOT OF ARCTIC AIR ARRIVES SUNDAY WITH
ACCUMULATING LAKE EFFECT SNOW LIKELY.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 258 PM EST THU JAN 14 2016
GIVEN THE CLEARING SKIES AND WARM AIR ADVECTION I DOWNPLAYED THE
POTENTIAL FOR SLEET AND FREEZING RAIN TONIGHT. STILL THE NORTHEAST
COUNTIES WILL BE CLOSE TO THE WARM FRONT AND A SMALL RISK EXISTS
UP THERE. TOO LOW FOR ANY HEADLINE AT THIS POINT. THE HRRR RUC WAS
SHOWING FOG TRYING TO DEVELOP LATER TONIGHT. I ADDED THIS TO THE
FORECAST.
A BETTER RISK FOR MEASURABLE RAIN EXISTS FOR FRIDAY. THE WAVE OF
LOW PRESSURE TRACKS EASTWARD THROUGH THE CWA. ENOUGH FORCING AND
MOISTURE AROUND FOR LIGHT RAIN. AT THIS POINT IT APPEARS THAT MOST
LOCATIONS WILL SEE LESS THAN A QUARTER INCH.
COLDER AIR RETURNS QUICKLY BEHIND THE DEPARTING LOW. THUS FRIDAY
NIGHT LOOKS LIKE MAINLY SNOW...IF ANY PRECIPITATION AT ALL. I AM
NOT CONFIDENT THAT WE WILL SEE MUCH PRECIPITATION AS THIS INITIAL
COLDER AIRMASS BEHIND THE LOW IS NOT THAT COLD...850 MB TEMPS DOWN
TO -8 DEG C OR SO. A BETTER SURGE OF ARCTIC AIR MOVES IN FOR LATER
SATURDAY NIGHT.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 258 PM EST THU JAN 14 2016
WE STILL EXPECT A FEW INCHES OF LAKE EFFECT SNOW ON SUNDAY AND INTO
MONDAY. THE BULK OF THIS WILL FALL ON SUNDAY WITH A GENERAL 3 TO 5
INCHES ACROSS THE WESTERN ZONES. SNOW SHOWERS SHOULD REACH FAR
INLAND AS THE FLOW WILL BE FROM ABOUT 280 DEGREES WITH SOME ENHANCED
LOW LEVEL CONVERGENCE POSSIBLE ACROSS THE SOUTHERN HALF OF THE
FORECAST AREA.
SUNDAY ALSO LOOKS MIGHTY COLD WITH 850 MB TEMPS BLO MINUS 20C AND
STRONG CAA ALL DAY. CORE OF THE COLDEST AIR COMES THROUGH DURING THE
AFTERNOON AND EVENING SO MAX TEMPS MIGHT OCCUR SUNDAY MORNING WITH
STEADY FOR FALLING TEMPERATURES DURING THE DAY AND WIND CHILLS
POSSIBLY GETTING DOWN TO 10 BELOW DURING THE EVENING.
MONDAY WILL SEE LAKE EFFECT SNOW SHOWERS CONTINUE WITH CYCLONIC FLOW
BUT ACCUMS ARE LIMITED BY INVERSION HEIGHTS AOB 5 KFT AND THE DGZ
NEAR THE SFC...SO ONLY ANOTHER INCH OR TWO EXPECTED.
THERE WILL BE A SLOW MODERATION IN TEMPERATURES FROM TUESDAY THROUGH
THURSDAY. IT REMAINS COLD ENOUGH FOR OCCASIONAL LAKE EFFECT SNOW
SHOWERS...ALTHOUGH AMOUNTS ARE EXPECTED TO BE LIGHT AS INVERSION
HEIGHTS REMAIN AOB 5 KFT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1255 PM EST THU JAN 14 2016
WE WILL SEE VARIABLE CONDITIONS THIS AFTERNOON ACROSS LOWER
MICHIGAN. CEILINGS WILL BE AROUND 1000 FT AGL ACROSS CENTRAL LOWER
MICHIGAN AT GRR AND MKG WHILE VFR CONDITIONS ARE FURTHER SOUTH AT
AZO...BTL AND JXN. IFR CONDITIONS ARE EXPECTED TO BECOME
WIDESPREAD OVERNIGHT AND THEN LIFR TOWARDS LATE MORNING ON FRIDAY
AS LOW CLOUDS AND DRIZZLE MOVE IN.
WINDS WILL BE SOUTH TO SOUTHEAST AROUND 10 KNOTS THROUGH FRIDAY
MORNING.
&&
.MARINE...
ISSUED AT 258 PM EST THU JAN 14 2016
SOUTH TO SOUTHEAST WINDS WILL INCREASE TONIGHT. THIS WILL CAUSE
WAVES TO BUILD CLOSE TO SMALL CRAFT ADVISORY CRITERIA. THE WINDS
WILL VEER TO THE NORTHWEST BY FRIDAY NIGHT. AS COLDER AIR WORKS IT
WAY IN THE WAVES WILL BUILD TO OVER 4 FEET. HAZARDOUS CONDITIONS
FOR SMALL CRAFT WILL PERSIST THROUGH THE WEEKEND.
&&
.HYDROLOGY...
ISSUED AT 108 PM EST THU JAN 14 2016
ICE JAMMING IS LIKELY AFFECTING THE GRAND RIVER AT ROBINSON
TOWNSHIP. WARMER TEMPERATURES ALONG WITH SOME RAINFALL FRIDAY MAY
HELP LOOSEN THE JAM AND SOFTEN THE ICE FURTHER. THE FLOATING ICE
ON THE RIVER DOES NOT LOOK PARTICULARLY THICK SO IT MAY NOT TAKE
MUCH TO FREE THE JAM UP WITH MORE FAVORABLE WEATHER CONDITIONS
THROUGH FRIDAY. ELSEWHERE THERE IS LIKELY SOME ICE BUILDING
UPSTREAM OF DIMONDALE ON THE GRAND RIVER. HOWEVER...THE RIVER
STAGE AT DIMONDALE IS WELL BELOW BANKFULL PRESENTLY. WE WILL
CONTINUE TO MONITOR AREA RIVERS. A DEEP FREEZE LATER THIS WEEKEND
INTO NEXT WEEK WILL PUT A STOP TO ICE MOVEMENT AND WILL ALLOW FOR
ICE TO REDEVELOP. IF THE ROBINSON TWP JAM DOES NOT RELEASE BY THE
TIME THE ARCTIC AIR ARRIVES THEN MORE SIGNIFICANT ISSUES MAY
DEVELOP POTENTIALLY...WITH FURTHER ICE FORMATION OCCURRING.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
SYNOPSIS...MJS
SHORT TERM...MJS
LONG TERM...OSTUNO
AVIATION...OSTUNO
HYDROLOGY...HOVING
MARINE...MJS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1243 PM EST THU JAN 14 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 327 AM EST THU JAN 14 2016
THE LAKE INDUCED SURFACE TROUGH CONTINUES TO WEAKEN AND SAG TO THE
SOUTH THIS MORNING AS A HIGH IS LOCATED JUST TO THE NORTH OF LAKE
SUPERIOR AND IS LEADING TO NORTHERLY FLOW OVER THE NORTHERN THIRD OF
LAKE SUPERIOR. STILL SEEING A LARGE EXPANSE OF LAKE EFFECT CLOUDS
OVER LAKE SUPERIOR...BUT WITH 850MB TEMPERATURES MODERATING SINCE
YESTERDAY (NOW UP TO -16C WEST AND -19C EAST ON RAP ANALYSIS) AND
THE WIND FIELD BECOMING MORE VARIABLE...HAVE SEEN THE LAKE EFFECT
BECOME A LITTLE MORE DISORGANIZED OVER THE LAST COUPLE OF HOURS OVER
SOUTH CENTRAL LAKE SUPERIOR. THE ONE EXCEPTION IS WHERE THERE IS
INCREASED CONVERGENCE FROM THE LAND BREEZE OFF MARQUETTE
COUNTY...WHICH HAS LED TO A NEARLY STATIONARY BAND AFFECTING THE
AREA FROM THE MARQUETTE/ALGER LINE THROUGH AREAS JUST TO THE WEST OF
AU TRAIN. RADAR IS ESTIMATING SNOWFALL RATES BETWEEN 0.5-1 INCH AN
HOUR...SO HAVE TRENDED POPS AND SNOWFALL AMOUNTS UP THERE OVER THE
NEXT COUPLE OF HOURS. EXPECT THE DIMINISHING TREND TO CONTINUE
THROUGH DAYBREAK AS THE WINDS START TO RESPOND TO THE APPROACHING
LOW THAT WILL BE THE PRIMARY FORECAST CONCERN FOR THE SHORT TERM
FORECAST. ONE OTHER INTERESTING ITEM TO NOTE WAS THE DEVELOPMENT AND
ENHANCEMENT OF SNOW DOWNWIND OF THE MINES NEAR PALMER. THE INITIAL
BAND STARTED AROUND 330Z AND HAVE SEEN TWO SEPARATE STREAMERS
DOWNWIND THROUGH THE NIGHT. WITH THE WINDS BACKING A LITTLE MORE TO
THE WEST...THEY HAVE NOW SHIFTED INTO KSAW AND ARE REDUCING
VISIBILITIES BELOW 2 MILES.
A 993MB SURFACE LOW IS CURRENTLY LOCATED IN WESTERN NORTH DAKOTA AND
AIDED BY A SHORTWAVE CROSSING THE NORTHERN ROCKIES. THE LOW AND
SHORTWAVE WILL CONTINUE TO THE SOUTHEAST TODAY AND REACH THE
MINNESOTA/IOWA BORDER BY 00Z FRIDAY. THE LOW WILL THEN LIFT
NORTHEAST AND STRENGTHEN TONIGHT AS THE NORTHERN EDGE OF THE
SHORTWAVE BECOMES DOMINATE AND BE LOCATED JUST SOUTH OF THE DOOR
PENINSULA AT 12Z FRIDAY. THE INITIAL FORCING MECHANISM FOR THE SNOW
MOVING INTO THE AREA LATE THIS MORNING AND THROUGH THE AFTERNOON
WILL BE A WEAK SHORTWAVE LIFTING EAST-NORTHEAST AHEAD OF THE PRIMARY
SHORTWAVE AND WEAK 700-500MB WARM AIR ADVECTION AND Q-VECTOR
CONVERGENCE. EXPECT THAT TO LEAD TO AN AREA OF LIGHT SNOW MOVING
INTO THE AREA LATE THIS MORNING OUT WEST AND WILL CONTINUE THE
UPWARD TREND IN THE POPS FOR THIS AFTERNOON (GOING TO DEFINITE
VALUES WEST AND LIKELY EAST IN THE AFTERNOON). THEN HEADING INTO
TONIGHT...THE INITIAL FORCING AND DEEP MOISTURE BEGINS TO PIVOT OVER
NORTHERN LAKE SUPERIOR AS THE UPPER TROUGH AXIS APPROACHES AND HELPS
TO SHARPEN THE MID LEVEL WARM AIR ADVECTION. IN ADDITION...THERE MAY
BE SOME WEAK LAKE ENHANCEMENT NEAR LAKE MICHIGAN (BETWEEN MANISTIQUE
AND ESCANABA) AND ALSO OVER THE KEWEENAW PENINSULA UNDER THE EAST-
SOUTHEAST LOW LEVEL FLOW. WITH THE LOCATION OF THE DEEP MOISTURE
OVER LAKE SUPERIOR TONIGHT AND PIVOTING OF THE FORCING...EXPECT THE
BEST SNOW ACCUMULATIONS TO BE IN THAT AREA AND LEAVING THE KEWEENAW
PENINSULA RIGHT ON THE EDGE OF THE HEAVIER SNOW. MODELS FAIRLY
CONSISTENT IN PRODUCING AROUND A TENTH OF AN INCH OF QPF OVER THE
SOUTHEAST HALF OF THE CWA THIS AFTERNOON THROUGH TONIGHT...WITH
INCREASING AMOUNTS AS YOU HEAD TOWARDS THE NORTHWESTERN HALF OF CWA
WHERE AMOUNTS AROUND A QUARTER TO THREE TENTHS OF AN INCH ARE
EXPECTED (OVER NORTHWESTERN LAKE SUPERIOR AND THE KEWEENAW
PENINSULA). SNOW RATIOS ARE A LITTLE TRICKY DUE TO THE VARIED
LOCATIONS OF THE BEST FORCING AND THE THERMAL PROFILE TRACKING
THROUGH AND JUST BELOW THE DGZ. THUS...HAVE FOLLOWED GENERAL
CONSENSUS OF THE COBB OUTPUT FROM THE NAM/GFS WHICH LEADS TO THE
HIGHEST RATIOS OVER THE KEWEENAW (AROUND 15 TO 1) AND LESSER AMOUNTS
FARTHER TO THE SOUTH (TRENDING DOWN TOWARDS 10-1 IN MENOMINEE
COUNTY). WITH THE GOING RATIOS AND QPF...SNOWFALL AMOUNTS FROM THIS
AFTERNOON THROUGH TONIGHT WILL BE AROUND A HALF INCH OVER SOUTHERN
MENOMINEE COUNTY...1-2 INCHES SOUTHEAST OF A LINE FROM BESSEMER TO
MARQUETTE AND 3-4 INCHES OVER NORTHERN HOUGHTON AND KEWEENAW
COUNTIES. WITH MOST OF THAT FALLING TONIGHT AND RATIOS AROUND 15-
1...WILL ISSUE A WINTER WEATHER ADVISORY FOR TONIGHT AND CONTINUE IT
INTO FRIDAY MORNING AS ANOTHER 1-2 INCHES IS EXPECTED THEN.
FINALLY...DID ADD SOME FREEZING DRIZZLE OVER THE SOUTH CENTRAL AFTER
THE DEEP MOISTURE CUTS OUT AFTER THE MAIN PRECIPITATION PUSHES NORTH
BY EARLY EVENING. THUS...LEFT WITH MOISTURE BELOW 6-7KFT...WHERE THE
TEMPERATURE PROFILE HOVERS BETWEEN -4 AND -10C.
SINCE THE UPPER REACHES OF THE CLOUD GENERALLY ARE COLD ENOUGH FOR
ICE CRYSTALS TO BE PRESENT...ONLY SHOWED SOME FREEZING DRIZZLE OVER
THE SOUTHERN HALF OF MENOMINEE COUNTY WHERE THE LOW LEVEL
TEMPERATURES WILL BE THE WARMEST.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 355 AM EST THU JAN 14 2016
MAIN FCST CONCERNS IN THE MEDIUM/EXTENDED RANGE ARE ON POPS/SN
TOTALS/NEED FOR HEADLINES ON FRI AS A SHRTWV/SFC LO TRACK JUST TO
THE S OF UPR MI AND THRU THE CENTRAL LKS. FOCUS FOR THE WEEKEND WL
SHIFT TO LES POPS/TOTALS AS A VERY COLD AIRMASS UNDER A CLOSED UPR
LO INVADES THE AREA. ALTHOUGH THERE ARE SOME DIFFERENCES IN FCST
DETAILS FOR NEXT WEEK...LOOKS LIKE THERE WL A SLOW MODERATION OF THE
VERY COLD WX EXPECTED THIS WEEKEND AS THE DEEP UPR LO/TROF EXITS TO
THE ENE.
FRI...SHRTWV OVER THE UPR MS RIVER VALLEY IS FCST TO MOVE TO OVER
LOWER MI BY 00Z SAT...WITH SFC LO PRES MOVING FM NRN WI TO NRN LK
HURON. ALTHOUGH ISENTROPIC ASCENT/DPVA/DEEP LYR QVECTOR CNVGC ON CYC
SIDE OF SHRTWV TRACK AS WELL AS UPR DVGC ENHANCED BY PLACEMENT IN
RRQ OF H3 JET MAX S OF JAMES BAY WL EXIT W-E AND CLEAR ALL BUT THE
ERN CWA BY 18Z...THE MODELS SHOW AREA OF DEEP MSTR LINGERING ABOVE
LLVL CYC NNE FLOW ON THE NW FLANK OF THE SFC LO PRES FOR AT LEAST
SEVERAL HRS EVEN AFTER THE SHARPER FORCING EXITS...WITH H85 TEMPS
FALLING TO ARND -10C OFFERING SOME LK ENHANCEMENT. AXIS OF H85-7
FGEN THAT WL BE SLIDING E WITH THE LO ON THE WRN EDGE OF THE DYNAMIC
FORCING MAY SUPPORT A PERIOD OF SOME HEAVIER SN AS WELL. H7 SPECIFIC
HUMIDITY FCST ARND 2 G/KG WOULD SUPPORT 12HR SNOWFALL UP TO 4 INCHES
WHERE THE SYNOPTIC FORCING OR LK/UPSLOPE ENHANCEMENT LINGER MOST OF
THE DAY...MOST LIKELY OVER THE E AND HIER TERRAIN OF THE NCENTRAL
EVEN THROUGH RATHER NARROW...HI DGZ CENTERED ARND 12K FT WOULD
SUPPORT LOWER SN/WATER RATIOS. THE 00Z GFS/NAM QPF UP TO 0.25-0.30
INCH IN THESE AREAS AND EXPECTED SN/WATER RATIOS UP TO 15:1 ALSO
POINT TOWARD A 3-4 INCH FRI SN TOTAL IN THESE AREAS. NRN EDGE OF DRY
SLOTTING THAT IS FCST TO IMPACT THE SCENTRAL WL LIMIT SN AMOUNTS IN
THAT AREA. OPTED TO CONTINUE SN ADVY OVER THE KEWEENAW THRU
18Z...WHEN BETTER DYNAMIC FORCING WL EXIT AND LLVL WINDS SHIFT TO A
LESS FVRBL NE DIRECTION. ALTHOUGH SN ADVYS WL LIKELY BE NECESSARY
FOR AT LEAST MARQUETTE COUNTY...WL NOT HOIST THE ADVY YET DUE TO
MAIN FOCUS IN THIRD PERIOD AND MARGINAL NATURE OF THE EXPECTED SN
TOTALS THAT ARE CLOSE TO MIN ADVY THRESHOLDS. DURING THE AFTN OVER
THE W...THE PCPN WL TEND TO TRANSITIONS TOWARD PURE LES WITH INCRSG
DEEP LYR QVECTOR DVGC/ SUBSIDENCE/MID LVL DRYING AND H85 TEMPS
FALLING TOWARD -13 TO -14C IN LLVL NLY FLOW BEHIND DEPARTING LO
PRES. ALTHOUGH TEMPS MAY TEND TO FALL IN THE AFTN ESPECIALLY OVER
THE W...MAX TEMPS WELL INTO THE 20S WL BE ABOVE NORMAL.
FRI NGT...AS H5 HGTS FALL UP TO 50M AHEAD OF SLOWLY APRCHG CLOSED LO
SLIDING SE THRU SCENTRAL CANADA...MODELS SHOW SHARPENING CYC NNW
FLOW ALONG LK INDUCED TROFFING AS CAA DROPS H85 TEMPS TO -17C TO
-18C OVER THE NW BY 12Z SAT. AT THE SAME TIME...THE 00Z NAM AND GFS
INDICATE SOME INCRSG MID LVL MSTR OVERNGT MAINLY OVER THE W HALF
AHEAD OF A WEAK SHRTWV SLIDING ESEWD AHEAD OF THE MAIN CLOSED LO.
THESE PARAMETERS SUG SOME LK ENHANCED SN WL IMPACT THE W LATER AT
NGT...WITH INCRSGLY FAVORABLE SN/WATER RATIOS SUPPORTING SN RATES
THAT WL AT LEAST APRCH ADVY CRITERIA. WITH THE INFLUX OF COLD AIR...
LO TEMPS WL FALL CLOSER TO NORMAL.
WEEKEND INTO MON...CLOSED UPR LO MARKING CENTER OF VERY COLD AIRMASS
MOVING INTO NW ONTARIO ON SAT IS FCST TO MIGRATE SE THRU THE UPR LKS
THIS WEEKEND ALONG WITH H85 TEMPS FCST AS LO AS -25 TO -27C CENTERED
ARND 12Z SUN...WHEN THE CORE OF COLDEST AIR LOOKS TO ARRIVE.
ALTHOUGH SN/WATER RATIOS WL FALL WITH THE INCRSGLY COLD AIR THAT
LOWERS THE DGZ TO NEAR THE SFC...PERSISTENT SHARPER CNVGC ASSOCIATED
WITH SOME LK INDUCED TROFFING AND DEEPER MSTR UNDER THE CLOSED LO WL
ALLOW FOR SOME ENHANCEMENT IN THE FAVORED UPSLOPE AREAS IN THE
OSCILLATING NNW TO NW WINDS THAT WL BACK TOWARD THE WNW SUN NGT/MON
FOLLOWING THE EXIT OF THE CLOSED LO TO THE E AND SHIFT OF ARCTIC HI
PRES TOWARD THE MID MS RIVER VALLEY AT 12Z MON. ALTHOUGH WIND GUSTS
WL PROBABLY BE NO HIER THAN 25-30 MPH...BLSN WHIPPED UP BY THESE
WINDS AND INCRSLY SMALL SN FLAKES WL BE EFFECTIVE AT REDUCING VSBY
IN EXPOSED LOCATIONS. BEST CHC FOR SOME HEAVIER ADVY SNOWS WL BE IN
THE FAVORED SN BELTS E OF MARQUETTE...WHERE LONGER FETCH LENGTH WL
ADD SOME MOISTENING AND WARMING TO MITIGATE THE LOWERING DGZ.
MAINTAINED HIER POPS THAN CONSENSUS FCST IN AREAS FAVORED FOR LES.
TEMPS SHOULD BE WELL BLO NORMAL THIS WEEKEND/MON...WITH MAX TEMPS ON
THE COLDEST DAY SUN FAILING TO GET ABOVE 5-10F OVER MOST OF THE W
HALF. CLD COVER/LK SUP MODERATION OF THE CHILL SHOULD LIMIT THE
NOCTURNAL FALL OF TEMPS... BUT SOME BLO ZERO MIN TEMPS ARE LIKELY AT
LEAST NEAR THE WI BORDER.
EXTENDED...AS THE CLOSED LO SHIFTS TO THE E AND HGTS BEGIN TO RISE
OVER THE UPR LKS...EXPECT A SLOW MODERATION OF TEMPS EARLY NEXT
WEEK. NOT SURPRISINGLY...THERE ARE CONSIDERABLE DIFFERENCES ON THE
DETAILS OF THIS CHANGING PATTERN. SOME OF THE LONGER RANGE
GUIDANCE...LED BY THE 00Z GFS...INDICATES MORE PERSISTENT TROFFING
AS SHRTWVS DIGGING SEWD THRU THE NW FLOW ALF MAINTAIN THE LOWER
HGTSAND MORE PERSISTENT LES. ON THE OTHER HAND...THE 13/12Z ECMWF
SHOWED A HI PRES RDG MOVING ACRS UPR MI ON MON NGT...BRINGING A VERY
COLD EARLY MRNG ON TUE FOLLOWED BY A CLIPPER TYPE SHRTWV THAT WOULD
BRING A PERIOD OF SOME WAA LIGHT SN LATER TUE INTO WED. CONSIDERING
THESE VERY DIFFERENT SCENARIOS...MAINTAINED THE CONSENSUS
EXTENDED FCST FOR THE LATER PERIODS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1243 PM EST THU JAN 14 2016
KIWD...OBSERVED CIGS FROM THE AWOS CONTINUE TO APPEAR UNRELIABLE AS
OF THIS THIS AFTERNOON AS 2SM -SN CLR IS BEING OBSERVED WHERE CLOUD
DECK SHOULD BE BELOW 3KFT. MOST UNCERTAIN LATER TONIGHT INTO EARLY
FRI AS MODELS DIFFER ON WHERE THE BACK SIDE OF THE MOISTURE WILL BE.
USED A GENERAL CONSENSUS OF MODEL GUIDANCE FOR THE FORECAST.
KCMX...WORST CONDITIONS EXPECTED TONIGHT INTO FRI AS WINDS BECOME
FAVORABLE FOR UPSLOPE/LAKE ENHANCEMENT OF SYSTEM SNOW MOVING THROUGH
THE AREA. COULD ALSO SEE BLSN AT THE SITE TONIGHT AND FRI.
KSAW...AN AREA OF SNOW WILL MOVE THROUGH THIS AFTERNOON/EARLY
EVENING AND WILL BE FOLLOWED BY DECREASING INTENSITY OF SNOW
TONIGHT. WINDS TURNING OUT OF THE N-NE ON FRI WILL FAVOR KSAW FOR
UPSLOPE/LAKE ENHANCEMENT OF SYSTEM SNOW...BRINGING THE WORST
CONDITIONS AT THAT POINT.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 327 AM EST THU JAN 14 2016
A SURFACE LOW IN THE NORTHERN PLAINS WILL MOVE INTO SOUTHERN
WISCONSIN TONIGHT BEFORE STRENGTHENING AND MOVING NORTHEAST AND
OVER LAKE HURON BY FRIDAY EVENING. AS THE LOW MOVES TO THE SOUTH OF
THE AREA...EXPECT WINDS TO SHIFT TO THE EAST TODAY AND NORTHEAST BY
FRIDAY MORNING BEFORE CONTINUING TO BACK TO THE NORTHWEST BY FRIDAY
NIGHT. AT THIS POINT...EXPECT WIND GUSTS UP TO 30KTS AS THE LOW
MOVES THROUGH. BEHIND THE LOW...ANOTHER SURGE OF COLD AIR WILL MOVE
OVER THE UPPER GREAT LAKES REGION AND LEAD TO THE POTENTIAL FOR
HEAVY FREEZING SPRAY BY SUNDAY (AND CONTINUE INTO MONDAY). THE
NORTHWESTERLY WINDS WILL BE PERSISTENT THROUGH THE WEEKEND UP TO
30KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 1 PM EST FRIDAY FOR MIZ001-003.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...KC
AVIATION...TITUS
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
627 AM EST THU JAN 14 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 327 AM EST THU JAN 14 2016
THE LAKE INDUCED SURFACE TROUGH CONTINUES TO WEAKEN AND SAG TO THE
SOUTH THIS MORNING AS A HIGH IS LOCATED JUST TO THE NORTH OF LAKE
SUPERIOR AND IS LEADING TO NORTHERLY FLOW OVER THE NORTHERN THIRD OF
LAKE SUPERIOR. STILL SEEING A LARGE EXPANSE OF LAKE EFFECT CLOUDS
OVER LAKE SUPERIOR...BUT WITH 850MB TEMPERATURES MODERATING SINCE
YESTERDAY (NOW UP TO -16C WEST AND -19C EAST ON RAP ANALYSIS) AND
THE WIND FIELD BECOMING MORE VARIABLE...HAVE SEEN THE LAKE EFFECT
BECOME A LITTLE MORE DISORGANIZED OVER THE LAST COUPLE OF HOURS OVER
SOUTH CENTRAL LAKE SUPERIOR. THE ONE EXCEPTION IS WHERE THERE IS
INCREASED CONVERGENCE FROM THE LAND BREEZE OFF MARQUETTE
COUNTY...WHICH HAS LED TO A NEARLY STATIONARY BAND AFFECTING THE
AREA FROM THE MARQUETTE/ALGER LINE THROUGH AREAS JUST TO THE WEST OF
AU TRAIN. RADAR IS ESTIMATING SNOWFALL RATES BETWEEN 0.5-1 INCH AN
HOUR...SO HAVE TRENDED POPS AND SNOWFALL AMOUNTS UP THERE OVER THE
NEXT COUPLE OF HOURS. EXPECT THE DIMINISHING TREND TO CONTINUE
THROUGH DAYBREAK AS THE WINDS START TO RESPOND TO THE APPROACHING
LOW THAT WILL BE THE PRIMARY FORECAST CONCERN FOR THE SHORT TERM
FORECAST. ONE OTHER INTERESTING ITEM TO NOTE WAS THE DEVELOPMENT AND
ENHANCEMENT OF SNOW DOWNWIND OF THE MINES NEAR PALMER. THE INITIAL
BAND STARTED AROUND 330Z AND HAVE SEEN TWO SEPARATE STREAMERS
DOWNWIND THROUGH THE NIGHT. WITH THE WINDS BACKING A LITTLE MORE TO
THE WEST...THEY HAVE NOW SHIFTED INTO KSAW AND ARE REDUCING
VISIBILITIES BELOW 2 MILES.
A 993MB SURFACE LOW IS CURRENTLY LOCATED IN WESTERN NORTH DAKOTA AND
AIDED BY A SHORTWAVE CROSSING THE NORTHERN ROCKIES. THE LOW AND
SHORTWAVE WILL CONTINUE TO THE SOUTHEAST TODAY AND REACH THE
MINNESOTA/IOWA BORDER BY 00Z FRIDAY. THE LOW WILL THEN LIFT
NORTHEAST AND STRENGTHEN TONIGHT AS THE NORTHERN EDGE OF THE
SHORTWAVE BECOMES DOMINATE AND BE LOCATED JUST SOUTH OF THE DOOR
PENINSULA AT 12Z FRIDAY. THE INITIAL FORCING MECHANISM FOR THE SNOW
MOVING INTO THE AREA LATE THIS MORNING AND THROUGH THE AFTERNOON
WILL BE A WEAK SHORTWAVE LIFTING EAST-NORTHEAST AHEAD OF THE PRIMARY
SHORTWAVE AND WEAK 700-500MB WARM AIR ADVECTION AND Q-VECTOR
CONVERGENCE. EXPECT THAT TO LEAD TO AN AREA OF LIGHT SNOW MOVING
INTO THE AREA LATE THIS MORNING OUT WEST AND WILL CONTINUE THE
UPWARD TREND IN THE POPS FOR THIS AFTERNOON (GOING TO DEFINITE
VALUES WEST AND LIKELY EAST IN THE AFTERNOON). THEN HEADING INTO
TONIGHT...THE INITIAL FORCING AND DEEP MOISTURE BEGINS TO PIVOT OVER
NORTHERN LAKE SUPERIOR AS THE UPPER TROUGH AXIS APPROACHES AND HELPS
TO SHARPEN THE MID LEVEL WARM AIR ADVECTION. IN ADDITION...THERE MAY
BE SOME WEAK LAKE ENHANCEMENT NEAR LAKE MICHIGAN (BETWEEN MANISTIQUE
AND ESCANABA) AND ALSO OVER THE KEWEENAW PENINSULA UNDER THE EAST-
SOUTHEAST LOW LEVEL FLOW. WITH THE LOCATION OF THE DEEP MOISTURE
OVER LAKE SUPERIOR TONIGHT AND PIVOTING OF THE FORCING...EXPECT THE
BEST SNOW ACCUMULATIONS TO BE IN THAT AREA AND LEAVING THE KEWEENAW
PENINSULA RIGHT ON THE EDGE OF THE HEAVIER SNOW. MODELS FAIRLY
CONSISTENT IN PRODUCING AROUND A TENTH OF AN INCH OF QPF OVER THE
SOUTHEAST HALF OF THE CWA THIS AFTERNOON THROUGH TONIGHT...WITH
INCREASING AMOUNTS AS YOU HEAD TOWARDS THE NORTHWESTERN HALF OF CWA
WHERE AMOUNTS AROUND A QUARTER TO THREE TENTHS OF AN INCH ARE
EXPECTED (OVER NORTHWESTERN LAKE SUPERIOR AND THE KEWEENAW
PENINSULA). SNOW RATIOS ARE A LITTLE TRICKY DUE TO THE VARIED
LOCATIONS OF THE BEST FORCING AND THE THERMAL PROFILE TRACKING
THROUGH AND JUST BELOW THE DGZ. THUS...HAVE FOLLOWED GENERAL
CONSENSUS OF THE COBB OUTPUT FROM THE NAM/GFS WHICH LEADS TO THE
HIGHEST RATIOS OVER THE KEWEENAW (AROUND 15 TO 1) AND LESSER AMOUNTS
FARTHER TO THE SOUTH (TRENDING DOWN TOWARDS 10-1 IN MENOMINEE
COUNTY). WITH THE GOING RATIOS AND QPF...SNOWFALL AMOUNTS FROM THIS
AFTERNOON THROUGH TONIGHT WILL BE AROUND A HALF INCH OVER SOUTHERN
MENOMINEE COUNTY...1-2 INCHES SOUTHEAST OF A LINE FROM BESSEMER TO
MARQUETTE AND 3-4 INCHES OVER NORTHERN HOUGHTON AND KEWEENAW
COUNTIES. WITH MOST OF THAT FALLING TONIGHT AND RATIOS AROUND 15-
1...WILL ISSUE A WINTER WEATHER ADVISORY FOR TONIGHT AND CONTINUE IT
INTO FRIDAY MORNING AS ANOTHER 1-2 INCHES IS EXPECTED THEN.
FINALLY...DID ADD SOME FREEZING DRIZZLE OVER THE SOUTH CENTRAL AFTER
THE DEEP MOISTURE CUTS OUT AFTER THE MAIN PRECIPITATION PUSHES NORTH
BY EARLY EVENING. THUS...LEFT WITH MOISTURE BELOW 6-7KFT...WHERE THE
TEMPERATURE PROFILE HOVERS BETWEEN -4 AND -10C.
SINCE THE UPPER REACHES OF THE CLOUD GENERALLY ARE COLD ENOUGH FOR
ICE CRYSTALS TO BE PRESENT...ONLY SHOWED SOME FREEZING DRIZZLE OVER
THE SOUTHERN HALF OF MENOMINEE COUNTY WHERE THE LOW LEVEL
TEMPERATURES WILL BE THE WARMEST.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 355 AM EST THU JAN 14 2016
MAIN FCST CONCERNS IN THE MEDIUM/EXTENDED RANGE ARE ON POPS/SN
TOTALS/NEED FOR HEADLINES ON FRI AS A SHRTWV/SFC LO TRACK JUST TO
THE S OF UPR MI AND THRU THE CENTRAL LKS. FOCUS FOR THE WEEKEND WL
SHIFT TO LES POPS/TOTALS AS A VERY COLD AIRMASS UNDER A CLOSED UPR
LO INVADES THE AREA. ALTHOUGH THERE ARE SOME DIFFERENCES IN FCST
DETAILS FOR NEXT WEEK...LOOKS LIKE THERE WL A SLOW MODERATION OF THE
VERY COLD WX EXPECTED THIS WEEKEND AS THE DEEP UPR LO/TROF EXITS TO
THE ENE.
FRI...SHRTWV OVER THE UPR MS RIVER VALLEY IS FCST TO MOVE TO OVER
LOWER MI BY 00Z SAT...WITH SFC LO PRES MOVING FM NRN WI TO NRN LK
HURON. ALTHOUGH ISENTROPIC ASCENT/DPVA/DEEP LYR QVECTOR CNVGC ON CYC
SIDE OF SHRTWV TRACK AS WELL AS UPR DVGC ENHANCED BY PLACEMENT IN
RRQ OF H3 JET MAX S OF JAMES BAY WL EXIT W-E AND CLEAR ALL BUT THE
ERN CWA BY 18Z...THE MODELS SHOW AREA OF DEEP MSTR LINGERING ABOVE
LLVL CYC NNE FLOW ON THE NW FLANK OF THE SFC LO PRES FOR AT LEAST
SEVERAL HRS EVEN AFTER THE SHARPER FORCING EXITS...WITH H85 TEMPS
FALLING TO ARND -10C OFFERING SOME LK ENHANCEMENT. AXIS OF H85-7
FGEN THAT WL BE SLIDING E WITH THE LO ON THE WRN EDGE OF THE DYNAMIC
FORCING MAY SUPPORT A PERIOD OF SOME HEAVIER SN AS WELL. H7 SPECIFIC
HUMIDITY FCST ARND 2 G/KG WOULD SUPPORT 12HR SNOWFALL UP TO 4 INCHES
WHERE THE SYNOPTIC FORCING OR LK/UPSLOPE ENHANCEMENT LINGER MOST OF
THE DAY...MOST LIKELY OVER THE E AND HIER TERRAIN OF THE NCENTRAL
EVEN THROUGH RATHER NARROW...HI DGZ CENTERED ARND 12K FT WOULD
SUPPORT LOWER SN/WATER RATIOS. THE 00Z GFS/NAM QPF UP TO 0.25-0.30
INCH IN THESE AREAS AND EXPECTED SN/WATER RATIOS UP TO 15:1 ALSO
POINT TOWARD A 3-4 INCH FRI SN TOTAL IN THESE AREAS. NRN EDGE OF DRY
SLOTTING THAT IS FCST TO IMPACT THE SCENTRAL WL LIMIT SN AMOUNTS IN
THAT AREA. OPTED TO CONTINUE SN ADVY OVER THE KEWEENAW THRU
18Z...WHEN BETTER DYNAMIC FORCING WL EXIT AND LLVL WINDS SHIFT TO A
LESS FVRBL NE DIRECTION. ALTHOUGH SN ADVYS WL LIKELY BE NECESSARY
FOR AT LEAST MARQUETTE COUNTY...WL NOT HOIST THE ADVY YET DUE TO
MAIN FOCUS IN THIRD PERIOD AND MARGINAL NATURE OF THE EXPECTED SN
TOTALS THAT ARE CLOSE TO MIN ADVY THRESHOLDS. DURING THE AFTN OVER
THE W...THE PCPN WL TEND TO TRANSITIONS TOWARD PURE LES WITH INCRSG
DEEP LYR QVECTOR DVGC/ SUBSIDENCE/MID LVL DRYING AND H85 TEMPS
FALLING TOWARD -13 TO -14C IN LLVL NLY FLOW BEHIND DEPARTING LO
PRES. ALTHOUGH TEMPS MAY TEND TO FALL IN THE AFTN ESPECIALLY OVER
THE W...MAX TEMPS WELL INTO THE 20S WL BE ABOVE NORMAL.
FRI NGT...AS H5 HGTS FALL UP TO 50M AHEAD OF SLOWLY APRCHG CLOSED LO
SLIDING SE THRU SCENTRAL CANADA...MODELS SHOW SHARPENING CYC NNW
FLOW ALONG LK INDUCED TROFFING AS CAA DROPS H85 TEMPS TO -17C TO
-18C OVER THE NW BY 12Z SAT. AT THE SAME TIME...THE 00Z NAM AND GFS
INDICATE SOME INCRSG MID LVL MSTR OVERNGT MAINLY OVER THE W HALF
AHEAD OF A WEAK SHRTWV SLIDING ESEWD AHEAD OF THE MAIN CLOSED LO.
THESE PARAMETERS SUG SOME LK ENHANCED SN WL IMPACT THE W LATER AT
NGT...WITH INCRSGLY FAVORABLE SN/WATER RATIOS SUPPORTING SN RATES
THAT WL AT LEAST APRCH ADVY CRITERIA. WITH THE INFLUX OF COLD AIR...
LO TEMPS WL FALL CLOSER TO NORMAL.
WEEKEND INTO MON...CLOSED UPR LO MARKING CENTER OF VERY COLD AIRMASS
MOVING INTO NW ONTARIO ON SAT IS FCST TO MIGRATE SE THRU THE UPR LKS
THIS WEEKEND ALONG WITH H85 TEMPS FCST AS LO AS -25 TO -27C CENTERED
ARND 12Z SUN...WHEN THE CORE OF COLDEST AIR LOOKS TO ARRIVE.
ALTHOUGH SN/WATER RATIOS WL FALL WITH THE INCRSGLY COLD AIR THAT
LOWERS THE DGZ TO NEAR THE SFC...PERSISTENT SHARPER CNVGC ASSOCIATED
WITH SOME LK INDUCED TROFFING AND DEEPER MSTR UNDER THE CLOSED LO WL
ALLOW FOR SOME ENHANCEMENT IN THE FAVORED UPSLOPE AREAS IN THE
OSCILLATING NNW TO NW WINDS THAT WL BACK TOWARD THE WNW SUN NGT/MON
FOLLOWING THE EXIT OF THE CLOSED LO TO THE E AND SHIFT OF ARCTIC HI
PRES TOWARD THE MID MS RIVER VALLEY AT 12Z MON. ALTHOUGH WIND GUSTS
WL PROBABLY BE NO HIER THAN 25-30 MPH...BLSN WHIPPED UP BY THESE
WINDS AND INCRSLY SMALL SN FLAKES WL BE EFFECTIVE AT REDUCING VSBY
IN EXPOSED LOCATIONS. BEST CHC FOR SOME HEAVIER ADVY SNOWS WL BE IN
THE FAVORED SN BELTS E OF MARQUETTE...WHERE LONGER FETCH LENGTH WL
ADD SOME MOISTENING AND WARMING TO MITIGATE THE LOWERING DGZ.
MAINTAINED HIER POPS THAN CONSENSUS FCST IN AREAS FAVORED FOR LES.
TEMPS SHOULD BE WELL BLO NORMAL THIS WEEKEND/MON...WITH MAX TEMPS ON
THE COLDEST DAY SUN FAILING TO GET ABOVE 5-10F OVER MOST OF THE W
HALF. CLD COVER/LK SUP MODERATION OF THE CHILL SHOULD LIMIT THE
NOCTURNAL FALL OF TEMPS... BUT SOME BLO ZERO MIN TEMPS ARE LIKELY AT
LEAST NEAR THE WI BORDER.
EXTENDED...AS THE CLOSED LO SHIFTS TO THE E AND HGTS BEGIN TO RISE
OVER THE UPR LKS...EXPECT A SLOW MODERATION OF TEMPS EARLY NEXT
WEEK. NOT SURPRISINGLY...THERE ARE CONSIDERABLE DIFFERENCES ON THE
DETAILS OF THIS CHANGING PATTERN. SOME OF THE LONGER RANGE
GUIDANCE...LED BY THE 00Z GFS...INDICATES MORE PERSISTENT TROFFING
AS SHRTWVS DIGGING SEWD THRU THE NW FLOW ALF MAINTAIN THE LOWER
HGTSAND MORE PERSISTENT LES. ON THE OTHER HAND...THE 13/12Z ECMWF
SHOWED A HI PRES RDG MOVING ACRS UPR MI ON MON NGT...BRINGING A VERY
COLD EARLY MRNG ON TUE FOLLOWED BY A CLIPPER TYPE SHRTWV THAT WOULD
BRING A PERIOD OF SOME WAA LIGHT SN LATER TUE INTO WED. CONSIDERING
THESE VERY DIFFERENT SCENARIOS...MAINTAINED THE CONSENSUS
EXTENDED FCST FOR THE LATER PERIODS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 626 AM EST THU JAN 14 2016
MVFR CEILINGS ARE EXPECTED TO CONTINUE THIS MORNING AT THE THREE TAF
SITES...ALTHOUGH KSAW COULD SEE SOME FLUCTUATIONS BASED OF THE MINE
EFFECT SNOW OCCURRING THERE THROUGH MUCH OF THE NIGHT UNDER THE WEST-
NORTHWEST WINDS. WILL CONTINUE TO SHOW BRIEFLY LOWER CONDITIONS FOR
THE FIRST COUPLE OF HOURS...THEN AS WINDS WEAKEN AND TURN SOUTHEAST
THE SITE COULD BRIEFLY TREND UP TO VFR.
OTHERWISE...EXPECT DETERIORATING CONDITIONS LATER THIS MORNING AND
THROUGH THE AFTERNOON AS WIDESPREAD SNOW SLIDES EAST-NORTHEAST
ACROSS THE AREA. WILL LOWER CONDITIONS TO IFR VISIBILITIES AS THE
SNOW MOVES THROUGH TODAY INTO EARLY THIS EVENING. SHOULD SEE SLIGHT
IMPROVEMENT IN CONDITIONS AT KSAW/KIWD THIS EVENING AS THE MAIN AREA
OF SNOW IS LOCATED NEAR KCMX...BUT THEN DETERIORATING CONDITIONS
LATE AS THE SNOW DROPS BACK SOUTHEAST OVER THE SITES.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 327 AM EST THU JAN 14 2016
A SURFACE LOW IN THE NORTHERN PLAINS WILL MOVE INTO SOUTHERN
WISCONSIN TONIGHT BEFORE STRENGTHENING AND MOVING NORTHEAST AND
OVER LAKE HURON BY FRIDAY EVENING. AS THE LOW MOVES TO THE SOUTH OF
THE AREA...EXPECT WINDS TO SHIFT TO THE EAST TODAY AND NORTHEAST BY
FRIDAY MORNING BEFORE CONTINUING TO BACK TO THE NORTHWEST BY FRIDAY
NIGHT. AT THIS POINT...EXPECT WIND GUSTS UP TO 30KTS AS THE LOW
MOVES THROUGH. BEHIND THE LOW...ANOTHER SURGE OF COLD AIR WILL MOVE
OVER THE UPPER GREAT LAKES REGION AND LEAD TO THE POTENTIAL FOR
HEAVY FREEZING SPRAY BY SUNDAY (AND CONTINUE INTO MONDAY). THE
NORTHWESTERLY WINDS WILL BE PERSISTENT THROUGH THE WEEKEND UP TO
30KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY FROM 1 PM THIS AFTERNOON TO 1 PM EST
FRIDAY FOR MIZ001-003.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...KC
AVIATION...SRF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
356 AM EST THU JAN 14 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 327 AM EST THU JAN 14 2016
THE LAKE INDUCED SURFACE TROUGH CONTINUES TO WEAKEN AND SAG TO THE
SOUTH THIS MORNING AS A HIGH IS LOCATED JUST TO THE NORTH OF LAKE
SUPERIOR AND IS LEADING TO NORTHERLY FLOW OVER THE NORTHERN THIRD OF
LAKE SUPERIOR. STILL SEEING A LARGE EXPANSE OF LAKE EFFECT CLOUDS
OVER LAKE SUPERIOR...BUT WITH 850MB TEMPERATURES MODERATING SINCE
YESTERDAY (NOW UP TO -16C WEST AND -19C EAST ON RAP ANALYSIS) AND
THE WIND FIELD BECOMING MORE VARIABLE...HAVE SEEN THE LAKE EFFECT
BECOME A LITTLE MORE DISORGANIZED OVER THE LAST COUPLE OF HOURS OVER
SOUTH CENTRAL LAKE SUPERIOR. THE ONE EXCEPTION IS WHERE THERE IS
INCREASED CONVERGENCE FROM THE LAND BREEZE OFF MARQUETTE
COUNTY...WHICH HAS LED TO A NEARLY STATIONARY BAND AFFECTING THE
AREA FROM THE MARQUETTE/ALGER LINE THROUGH AREAS JUST TO THE WEST OF
AU TRAIN. RADAR IS ESTIMATING SNOWFALL RATES BETWEEN 0.5-1 INCH AN
HOUR...SO HAVE TRENDED POPS AND SNOWFALL AMOUNTS UP THERE OVER THE
NEXT COUPLE OF HOURS. EXPECT THE DIMINISHING TREND TO CONTINUE
THROUGH DAYBREAK AS THE WINDS START TO RESPOND TO THE APPROACHING
LOW THAT WILL BE THE PRIMARY FORECAST CONCERN FOR THE SHORT TERM
FORECAST. ONE OTHER INTERESTING ITEM TO NOTE WAS THE DEVELOPMENT AND
ENHANCEMENT OF SNOW DOWNWIND OF THE MINES NEAR PALMER. THE INITIAL
BAND STARTED AROUND 330Z AND HAVE SEEN TWO SEPARATE STREAMERS
DOWNWIND THROUGH THE NIGHT. WITH THE WINDS BACKING A LITTLE MORE TO
THE WEST...THEY HAVE NOW SHIFTED INTO KSAW AND ARE REDUCING
VISIBILITIES BELOW 2 MILES.
A 993MB SURFACE LOW IS CURRENTLY LOCATED IN WESTERN NORTH DAKOTA AND
AIDED BY A SHORTWAVE CROSSING THE NORTHERN ROCKIES. THE LOW AND
SHORTWAVE WILL CONTINUE TO THE SOUTHEAST TODAY AND REACH THE
MINNESOTA/IOWA BORDER BY 00Z FRIDAY. THE LOW WILL THEN LIFT
NORTHEAST AND STRENGTHEN TONIGHT AS THE NORTHERN EDGE OF THE
SHORTWAVE BECOMES DOMINATE AND BE LOCATED JUST SOUTH OF THE DOOR
PENINSULA AT 12Z FRIDAY. THE INITIAL FORCING MECHANISM FOR THE SNOW
MOVING INTO THE AREA LATE THIS MORNING AND THROUGH THE AFTERNOON
WILL BE A WEAK SHORTWAVE LIFTING EAST-NORTHEAST AHEAD OF THE PRIMARY
SHORTWAVE AND WEAK 700-500MB WARM AIR ADVECTION AND Q-VECTOR
CONVERGENCE. EXPECT THAT TO LEAD TO AN AREA OF LIGHT SNOW MOVING
INTO THE AREA LATE THIS MORNING OUT WEST AND WILL CONTINUE THE
UPWARD TREND IN THE POPS FOR THIS AFTERNOON (GOING TO DEFINITE
VALUES WEST AND LIKELY EAST IN THE AFTERNOON). THEN HEADING INTO
TONIGHT...THE INITIAL FORCING AND DEEP MOISTURE BEGINS TO PIVOT OVER
NORTHERN LAKE SUPERIOR AS THE UPPER TROUGH AXIS APPROACHES AND HELPS
TO SHARPEN THE MID LEVEL WARM AIR ADVECTION. IN ADDITION...THERE MAY
BE SOME WEAK LAKE ENHANCEMENT NEAR LAKE MICHIGAN (BETWEEN MANISTIQUE
AND ESCANABA) AND ALSO OVER THE KEWEENAW PENINSULA UNDER THE EAST-
SOUTHEAST LOW LEVEL FLOW. WITH THE LOCATION OF THE DEEP MOISTURE
OVER LAKE SUPERIOR TONIGHT AND PIVOTING OF THE FORCING...EXPECT THE
BEST SNOW ACCUMULATIONS TO BE IN THAT AREA AND LEAVING THE KEWEENAW
PENINSULA RIGHT ON THE EDGE OF THE HEAVIER SNOW. MODELS FAIRLY
CONSISTENT IN PRODUCING AROUND A TENTH OF AN INCH OF QPF OVER THE
SOUTHEAST HALF OF THE CWA THIS AFTERNOON THROUGH TONIGHT...WITH
INCREASING AMOUNTS AS YOU HEAD TOWARDS THE NORTHWESTERN HALF OF CWA
WHERE AMOUNTS AROUND A QUARTER TO THREE TENTHS OF AN INCH ARE
EXPECTED (OVER NORTHWESTERN LAKE SUPERIOR AND THE KEWEENAW
PENINSULA). SNOW RATIOS ARE A LITTLE TRICKY DUE TO THE VARIED
LOCATIONS OF THE BEST FORCING AND THE THERMAL PROFILE TRACKING
THROUGH AND JUST BELOW THE DGZ. THUS...HAVE FOLLOWED GENERAL
CONSENSUS OF THE COBB OUTPUT FROM THE NAM/GFS WHICH LEADS TO THE
HIGHEST RATIOS OVER THE KEWEENAW (AROUND 15 TO 1) AND LESSER AMOUNTS
FARTHER TO THE SOUTH (TRENDING DOWN TOWARDS 10-1 IN MENOMINEE
COUNTY). WITH THE GOING RATIOS AND QPF...SNOWFALL AMOUNTS FROM THIS
AFTERNOON THROUGH TONIGHT WILL BE AROUND A HALF INCH OVER SOUTHERN
MENOMINEE COUNTY...1-2 INCHES SOUTHEAST OF A LINE FROM BESSEMER TO
MARQUETTE AND 3-4 INCHES OVER NORTHERN HOUGHTON AND KEWEENAW
COUNTIES. WITH MOST OF THAT FALLING TONIGHT AND RATIOS AROUND 15-
1...WILL ISSUE A WINTER WEATHER ADVISORY FOR TONIGHT AND CONTINUE IT
INTO FRIDAY MORNING AS ANOTHER 1-2 INCHES IS EXPECTED THEN.
FINALLY...DID ADD SOME FREEZING DRIZZLE OVER THE SOUTH CENTRAL AFTER
THE DEEP MOISTURE CUTS OUT AFTER THE MAIN PRECIPITATION PUSHES NORTH
BY EARLY EVENING. THUS...LEFT WITH MOISTURE BELOW 6-7KFT...WHERE THE
TEMPERATURE PROFILE HOVERS BETWEEN -4 AND -10C.
SINCE THE UPPER REACHES OF THE CLOUD GENERALLY ARE COLD ENOUGH FOR
ICE CRYSTALS TO BE PRESENT...ONLY SHOWED SOME FREEZING DRIZZLE OVER
THE SOUTHERN HALF OF MENOMINEE COUNTY WHERE THE LOW LEVEL
TEMPERATURES WILL BE THE WARMEST.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 355 AM EST THU JAN 14 2016
MAIN FCST CONCERNS IN THE MEDIUM/EXTENDED RANGE ARE ON POPS/SN
TOTALS/NEED FOR HEADLINES ON FRI AS A SHRTWV/SFC LO TRACK JUST TO
THE S OF UPR MI AND THRU THE CENTRAL LKS. FOCUS FOR THE WEEKEND WL
SHIFT TO LES POPS/TOTALS AS A VERY COLD AIRMASS UNDER A CLOSED UPR
LO INVADES THE AREA. ALTHOUGH THERE ARE SOME DIFFERENCES IN FCST
DETAILS FOR NEXT WEEK...LOOKS LIKE THERE WL A SLOW MODERATION OF THE
VERY COLD WX EXPECTED THIS WEEKEND AS THE DEEP UPR LO/TROF EXITS TO
THE ENE.
FRI...SHRTWV OVER THE UPR MS RIVER VALLEY IS FCST TO MOVE TO OVER
LOWER MI BY 00Z SAT...WITH SFC LO PRES MOVING FM NRN WI TO NRN LK
HURON. ALTHOUGH ISENTROPIC ASCENT/DPVA/DEEP LYR QVECTOR CNVGC ON CYC
SIDE OF SHRTWV TRACK AS WELL AS UPR DVGC ENHANCED BY PLACEMENT IN
RRQ OF H3 JET MAX S OF JAMES BAY WL EXIT W-E AND CLEAR ALL BUT THE
ERN CWA BY 18Z...THE MODELS SHOW AREA OF DEEP MSTR LINGERING ABOVE
LLVL CYC NNE FLOW ON THE NW FLANK OF THE SFC LO PRES FOR AT LEAST
SEVERAL HRS EVEN AFTER THE SHARPER FORCING EXITS...WITH H85 TEMPS
FALLING TO ARND -10C OFFERING SOME LK ENHANCEMENT. AXIS OF H85-7
FGEN THAT WL BE SLIDING E WITH THE LO ON THE WRN EDGE OF THE DYNAMIC
FORCING MAY SUPPORT A PERIOD OF SOME HEAVIER SN AS WELL. H7 SPECIFIC
HUMIDITY FCST ARND 2 G/KG WOULD SUPPORT 12HR SNOWFALL UP TO 4 INCHES
WHERE THE SYNOPTIC FORCING OR LK/UPSLOPE ENHANCEMENT LINGER MOST OF
THE DAY...MOST LIKELY OVER THE E AND HIER TERRAIN OF THE NCENTRAL
EVEN THROUGH RATHER NARROW...HI DGZ CENTERED ARND 12K FT WOULD
SUPPORT LOWER SN/WATER RATIOS. THE 00Z GFS/NAM QPF UP TO 0.25-0.30
INCH IN THESE AREAS AND EXPECTED SN/WATER RATIOS UP TO 15:1 ALSO
POINT TOWARD A 3-4 INCH FRI SN TOTAL IN THESE AREAS. NRN EDGE OF DRY
SLOTTING THAT IS FCST TO IMPACT THE SCENTRAL WL LIMIT SN AMOUNTS IN
THAT AREA. OPTED TO CONTINUE SN ADVY OVER THE KEWEENAW THRU
18Z...WHEN BETTER DYNAMIC FORCING WL EXIT AND LLVL WINDS SHIFT TO A
LESS FVRBL NE DIRECTION. ALTHOUGH SN ADVYS WL LIKELY BE NECESSARY
FOR AT LEAST MARQUETTE COUNTY...WL NOT HOIST THE ADVY YET DUE TO
MAIN FOCUS IN THIRD PERIOD AND MARGINAL NATURE OF THE EXPECTED SN
TOTALS THAT ARE CLOSE TO MIN ADVY THRESHOLDS. DURING THE AFTN OVER
THE W...THE PCPN WL TEND TO TRANSITIONS TOWARD PURE LES WITH INCRSG
DEEP LYR QVECTOR DVGC/ SUBSIDENCE/MID LVL DRYING AND H85 TEMPS
FALLING TOWARD -13 TO -14C IN LLVL NLY FLOW BEHIND DEPARTING LO
PRES. ALTHOUGH TEMPS MAY TEND TO FALL IN THE AFTN ESPECIALLY OVER
THE W...MAX TEMPS WELL INTO THE 20S WL BE ABOVE NORMAL.
FRI NGT...AS H5 HGTS FALL UP TO 50M AHEAD OF SLOWLY APRCHG CLOSED LO
SLIDING SE THRU SCENTRAL CANADA...MODELS SHOW SHARPENING CYC NNW
FLOW ALONG LK INDUCED TROFFING AS CAA DROPS H85 TEMPS TO -17C TO
-18C OVER THE NW BY 12Z SAT. AT THE SAME TIME...THE 00Z NAM AND GFS
INDICATE SOME INCRSG MID LVL MSTR OVERNGT MAINLY OVER THE W HALF
AHEAD OF A WEAK SHRTWV SLIDING ESEWD AHEAD OF THE MAIN CLOSED LO.
THESE PARAMETERS SUG SOME LK ENHANCED SN WL IMPACT THE W LATER AT
NGT...WITH INCRSGLY FAVORABLE SN/WATER RATIOS SUPPORTING SN RATES
THAT WL AT LEAST APRCH ADVY CRITERIA. WITH THE INFLUX OF COLD AIR...
LO TEMPS WL FALL CLOSER TO NORMAL.
WEEKEND INTO MON...CLOSED UPR LO MARKING CENTER OF VERY COLD AIRMASS
MOVING INTO NW ONTARIO ON SAT IS FCST TO MIGRATE SE THRU THE UPR LKS
THIS WEEKEND ALONG WITH H85 TEMPS FCST AS LO AS -25 TO -27C CENTERED
ARND 12Z SUN...WHEN THE CORE OF COLDEST AIR LOOKS TO ARRIVE.
ALTHOUGH SN/WATER RATIOS WL FALL WITH THE INCRSGLY COLD AIR THAT
LOWERS THE DGZ TO NEAR THE SFC...PERSISTENT SHARPER CNVGC ASSOCIATED
WITH SOME LK INDUCED TROFFING AND DEEPER MSTR UNDER THE CLOSED LO WL
ALLOW FOR SOME ENHANCEMENT IN THE FAVORED UPSLOPE AREAS IN THE
OSCILLATING NNW TO NW WINDS THAT WL BACK TOWARD THE WNW SUN NGT/MON
FOLLOWING THE EXIT OF THE CLOSED LO TO THE E AND SHIFT OF ARCTIC HI
PRES TOWARD THE MID MS RIVER VALLEY AT 12Z MON. ALTHOUGH WIND GUSTS
WL PROBABLY BE NO HIER THAN 25-30 MPH...BLSN WHIPPED UP BY THESE
WINDS AND INCRSLY SMALL SN FLAKES WL BE EFFECTIVE AT REDUCING VSBY
IN EXPOSED LOCATIONS. BEST CHC FOR SOME HEAVIER ADVY SNOWS WL BE IN
THE FAVORED SN BELTS E OF MARQUETTE...WHERE LONGER FETCH LENGTH WL
ADD SOME MOISTENING AND WARMING TO MITIGATE THE LOWERING DGZ.
MAINTAINED HIER POPS THAN CONSENSUS FCST IN AREAS FAVORED FOR LES.
TEMPS SHOULD BE WELL BLO NORMAL THIS WEEKEND/MON...WITH MAX TEMPS ON
THE COLDEST DAY SUN FAILING TO GET ABOVE 5-10F OVER MOST OF THE W
HALF. CLD COVER/LK SUP MODERATION OF THE CHILL SHOULD LIMIT THE
NOCTURNAL FALL OF TEMPS... BUT SOME BLO ZERO MIN TEMPS ARE LIKELY AT
LEAST NEAR THE WI BORDER.
EXTENDED...AS THE CLOSED LO SHIFTS TO THE E AND HGTS BEGIN TO RISE
OVER THE UPR LKS...EXPECT A SLOW MODERATION OF TEMPS EARLY NEXT
WEEK. NOT SURPRISINGLY...THERE ARE CONSIDERABLE DIFFERENCES ON THE
DETAILS OF THIS CHANGING PATTERN. SOME OF THE LONGER RANGE
GUIDANCE...LED BY THE 00Z GFS...INDICATES MORE PERSISTENT TROFFING
AS SHRTWVS DIGGING SEWD THRU THE NW FLOW ALF MAINTAIN THE LOWER
HGTSAND MORE PERSISTENT LES. ON THE OTHER HAND...THE 13/12Z ECMWF
SHOWED A HI PRES RDG MOVING ACRS UPR MI ON MON NGT...BRINGING A VERY
COLD EARLY MRNG ON TUE FOLLOWED BY A CLIPPER TYPE SHRTWV THAT WOULD
BRING A PERIOD OF SOME WAA LIGHT SN LATER TUE INTO WED. CONSIDERING
THESE VERY DIFFERENT SCENARIOS...MAINTAINED THE CONSENSUS
EXTENDED FCST FOR THE LATER PERIODS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1157 PM EST WED JAN 13 2016
MVFR CONDITIONS WILL PREVAIL AT KIWD AND KCMX INTO THU AFTERNOON. AT
KSAW...VFR CONDITIONS SHOULD PREVAIL INTO THU AFTERNOON. BY LATE THU
AFTERNOON...LIGHT SNOW MOVES IN WITH THE NEXT SYSTEM AND CONDITIONS
WILL DETERIORATE TO IFR/LOW MVFR AT ALL SITES.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 327 AM EST THU JAN 14 2016
A SURFACE LOW IN THE NORTHERN PLAINS WILL MOVE INTO SOUTHERN
WISCONSIN TONIGHT BEFORE STRENGTHENING AND MOVING NORTHEAST AND
OVER LAKE HURON BY FRIDAY EVENING. AS THE LOW MOVES TO THE SOUTH OF
THE AREA...EXPECT WINDS TO SHIFT TO THE EAST TODAY AND NORTHEAST BY
FRIDAY MORNING BEFORE CONTINUING TO BACK TO THE NORTHWEST BY FRIDAY
NIGHT. AT THIS POINT...EXPECT WIND GUSTS UP TO 30KTS AS THE LOW
MOVES THROUGH. BEHIND THE LOW...ANOTHER SURGE OF COLD AIR WILL MOVE
OVER THE UPPER GREAT LAKES REGION AND LEAD TO THE POTENTIAL FOR
HEAVY FREEZING SPRAY BY SUNDAY (AND CONTINUE INTO MONDAY). THE
NORTHWESTERLY WINDS WILL BE PERSISTENT THROUGH THE WEEKEND UP TO
30KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY FROM 1 PM THIS AFTERNOON TO 1 PM EST
FRIDAY FOR MIZ001-003.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...KC
AVIATION...07
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
328 AM EST THU JAN 14 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 327 AM EST THU JAN 14 2016
THE LAKE INDUCED SURFACE TROUGH CONTINUES TO WEAKEN AND SAG TO THE
SOUTH THIS MORNING AS A HIGH IS LOCATED JUST TO THE NORTH OF LAKE
SUPERIOR AND IS LEADING TO NORTHERLY FLOW OVER THE NORTHERN THIRD OF
LAKE SUPERIOR. STILL SEEING A LARGE EXPANSE OF LAKE EFFECT CLOUDS
OVER LAKE SUPERIOR...BUT WITH 850MB TEMPERATURES MODERATING SINCE
YESTERDAY (NOW UP TO -16C WEST AND -19C EAST ON RAP ANALYSIS) AND
THE WIND FIELD BECOMING MORE VARIABLE...HAVE SEEN THE LAKE EFFECT
BECOME A LITTLE MORE DISORGANIZED OVER THE LAST COUPLE OF HOURS OVER
SOUTH CENTRAL LAKE SUPERIOR. THE ONE EXCEPTION IS WHERE THERE IS
INCREASED CONVERGENCE FROM THE LAND BREEZE OFF MARQUETTE
COUNTY...WHICH HAS LED TO A NEARLY STATIONARY BAND AFFECTING THE
AREA FROM THE MARQUETTE/ALGER LINE THROUGH AREAS JUST TO THE WEST OF
AU TRAIN. RADAR IS ESTIMATING SNOWFALL RATES BETWEEN 0.5-1 INCH AN
HOUR...SO HAVE TRENDED POPS AND SNOWFALL AMOUNTS UP THERE OVER THE
NEXT COUPLE OF HOURS. EXPECT THE DIMINISHING TREND TO CONTINUE
THROUGH DAYBREAK AS THE WINDS START TO RESPOND TO THE APPROACHING
LOW THAT WILL BE THE PRIMARY FORECAST CONCERN FOR THE SHORT TERM
FORECAST. ONE OTHER INTERESTING ITEM TO NOTE WAS THE DEVELOPMENT AND
ENHANCEMENT OF SNOW DOWNWIND OF THE MINES NEAR PALMER. THE INITIAL
BAND STARTED AROUND 330Z AND HAVE SEEN TWO SEPARATE STREAMERS
DOWNWIND THROUGH THE NIGHT. WITH THE WINDS BACKING A LITTLE MORE TO
THE WEST...THEY HAVE NOW SHIFTED INTO KSAW AND ARE REDUCING
VISIBILITIES BELOW 2 MILES.
A 993MB SURFACE LOW IS CURRENTLY LOCATED IN WESTERN NORTH DAKOTA AND
AIDED BY A SHORTWAVE CROSSING THE NORTHERN ROCKIES. THE LOW AND
SHORTWAVE WILL CONTINUE TO THE SOUTHEAST TODAY AND REACH THE
MINNESOTA/IOWA BORDER BY 00Z FRIDAY. THE LOW WILL THEN LIFT
NORTHEAST AND STRENGTHEN TONIGHT AS THE NORTHERN EDGE OF THE
SHORTWAVE BECOMES DOMINATE AND BE LOCATED JUST SOUTH OF THE DOOR
PENINSULA AT 12Z FRIDAY. THE INITIAL FORCING MECHANISM FOR THE SNOW
MOVING INTO THE AREA LATE THIS MORNING AND THROUGH THE AFTERNOON
WILL BE A WEAK SHORTWAVE LIFTING EAST-NORTHEAST AHEAD OF THE PRIMARY
SHORTWAVE AND WEAK 700-500MB WARM AIR ADVECTION AND Q-VECTOR
CONVERGENCE. EXPECT THAT TO LEAD TO AN AREA OF LIGHT SNOW MOVING
INTO THE AREA LATE THIS MORNING OUT WEST AND WILL CONTINUE THE
UPWARD TREND IN THE POPS FOR THIS AFTERNOON (GOING TO DEFINITE
VALUES WEST AND LIKELY EAST IN THE AFTERNOON). THEN HEADING INTO
TONIGHT...THE INITIAL FORCING AND DEEP MOISTURE BEGINS TO PIVOT OVER
NORTHERN LAKE SUPERIOR AS THE UPPER TROUGH AXIS APPROACHES AND HELPS
TO SHARPEN THE MID LEVEL WARM AIR ADVECTION. IN ADDITION...THERE MAY
BE SOME WEAK LAKE ENHANCEMENT NEAR LAKE MICHIGAN (BETWEEN MANISTIQUE
AND ESCANABA) AND ALSO OVER THE KEWEENAW PENINSULA UNDER THE EAST-
SOUTHEAST LOW LEVEL FLOW. WITH THE LOCATION OF THE DEEP MOISTURE
OVER LAKE SUPERIOR TONIGHT AND PIVOTING OF THE FORCING...EXPECT THE
BEST SNOW ACCUMULATIONS TO BE IN THAT AREA AND LEAVING THE KEWEENAW
PENINSULA RIGHT ON THE EDGE OF THE HEAVIER SNOW. MODELS FAIRLY
CONSISTENT IN PRODUCING AROUND A TENTH OF AN INCH OF QPF OVER THE
SOUTHEAST HALF OF THE CWA THIS AFTERNOON THROUGH TONIGHT...WITH
INCREASING AMOUNTS AS YOU HEAD TOWARDS THE NORTHWESTERN HALF OF CWA
WHERE AMOUNTS AROUND A QUARTER TO THREE TENTHS OF AN INCH ARE
EXPECTED (OVER NORTHWESTERN LAKE SUPERIOR AND THE KEWEENAW
PENINSULA). SNOW RATIOS ARE A LITTLE TRICKY DUE TO THE VARIED
LOCATIONS OF THE BEST FORCING AND THE THERMAL PROFILE TRACKING
THROUGH AND JUST BELOW THE DGZ. THUS...HAVE FOLLOWED GENERAL
CONSENSUS OF THE COBB OUTPUT FROM THE NAM/GFS WHICH LEADS TO THE
HIGHEST RATIOS OVER THE KEWEENAW (AROUND 15 TO 1) AND LESSER AMOUNTS
FARTHER TO THE SOUTH (TRENDING DOWN TOWARDS 10-1 IN MENOMINEE
COUNTY). WITH THE GOING RATIOS AND QPF...SNOWFALL AMOUNTS FROM THIS
AFTERNOON THROUGH TONIGHT WILL BE AROUND A HALF INCH OVER SOUTHERN
MENOMINEE COUNTY...1-2 INCHES SOUTHEAST OF A LINE FROM BESSEMER TO
MARQUETTE AND 3-4 INCHES OVER NORTHERN HOUGHTON AND KEWEENAW
COUNTIES. WITH MOST OF THAT FALLING TONIGHT AND RATIOS AROUND 15-
1...WILL ISSUE A WINTER WEATHER ADVISORY FOR TONIGHT AND CONTINUE IT
INTO FRIDAY MORNING AS ANOTHER 1-2 INCHES IS EXPECTED THEN.
FINALLY...DID ADD SOME FREEZING DRIZZLE OVER THE SOUTH CENTRAL AFTER
THE DEEP MOISTURE CUTS OUT AFTER THE MAIN PRECIPITATION PUSHES NORTH
BY EARLY EVENING. THUS...LEFT WITH MOISTURE BELOW 6-7KFT...WHERE THE
TEMPERATURE PROFILE HOVERS BETWEEN -4 AND -10C.
SINCE THE UPPER REACHES OF THE CLOUD GENERALLY ARE COLD ENOUGH FOR
ICE CRYSTALS TO BE PRESENT...ONLY SHOWED SOME FREEZING DRIZZLE OVER
THE SOUTHERN HALF OF MENOMINEE COUNTY WHERE THE LOW LEVEL
TEMPERATURES WILL BE THE WARMEST.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 352 PM EST WED JAN 13 2016
...WIDESPREAD SNOW THU NIGHT INTO FRI WITH N/NW FLOW LAKE EFFECT
INTO THE WEEKEND...
TROUGHING ALOFT OVER EAST HALF OF CANADA WITH ADDITIONAL TROUGHING
EXPANDING FM CENTRAL CONUS TO EASTERN CONUS THIS WEEKEND. COLDER
CONDITIONS SHOULD MODERATE EARLY NEXT WEEK AS TROUGH AXIS MOVES TO
EASTERN CANADA AND HEIGHTS BEGIN RISING FM WESTERN CONUS TO GREAT
LAKES.
SHORTWAVE TROUGH CROSSING THE CENTRAL PLAINS ON THU NIGHT ALONG WITH
WEAKER LOW PRESSURE SYSTEM AROUND 1000MB WILL SPREAD LIGHT SNOW FM
NORTHERN MN INTO NORTHERN WI/UPPER MICHIGAN DUE TO ISENTROPIC ASCENT
AND WARM AIR ADVECTION WELL TO NORTH OF SFC WARM FRONT FM UPPER
MISSISSIPPI RIVER VALLEY TO LOWER GREAT LAKES. SNOW MAY BE ENHANCED
BY RIGHT ENTRANCE FORCING FM JET STREAK FM NW ONTARIO TO NEW ENGLAND.
MOST PERSISTENT SNOW FM THE SYSTEM ON THU NIGHT WILL BE OVER
KEWEENAW AND LAKE SUPERIOR. EASTERLY WINDS AHEAD OF APPROACHING SFC
LOW AND H85 TEMPS DOWN NEAR -10C WILL RESULT IN LAKE ENAHANCEMENT.
DGZ IS NARROW AND QUITE ELEVATED ABOVE H7 SO SLR/S AT LEAST FOR THU
NIGHT SHOULD HOLD IN THE 10-15:1 RANGE INSTEAD IN THE FLUFFIER 20:1
RANGE THAT WILL MOVE IN FOR FRI AND BEYOND.
BY FRI MORNING TROUGH ALOFT WILL BE ENTERING WESTERN GREAT LAKES
WHILE SFC LOW DEEPENS TO AROUND 997MB OVER NORTHERN LK MICHIGAN. LOW
CONTINUES TO DEEPEN TO 992MB BY FRI EVENING OVER NORTHERN LK
HURON/GEORGIAN BAY. THOUGH LARGER SCALE FORCING FM THE SHORTWAVE IN
TERMS OF DEEP LAYER Q-VECTOR CONVERGENCE DIMINISHES FROM WEST TO
EAST ON FRI...THE SHORTWAVE TROUGH/LOWER HEIGHTS IN THE VCNTY AND
WELL DEVELOPED COLD CONVEYOR BELT OF DEEPER MOISTURE THROUGH H7/H85-
H7 FRONTOGENESIS ACROSS MUCH OF NORTH HALF OF UPPER MICHIGAN SHOULD
KEEP LIGHT SNOW GOING OVER MOST OF CWA. SNOW WILL FALL MODERATE TO
POSSIBLY HEAVY NEAR LK SUPERIOR DUE TO LAKE ENHANCEMENT AND UPSLOPE
LIFT AS CYCLONIC NORTH/NORTHEAST WINDS ON BACK SIDE OF DEEPENING LOW
DRAW COLDER AIR INTO REGION WITH H85 TEMPS DROPPING BLO -10C.
PRELIMINARY INDICATIONS SUGGEST ADVISORIES WOULD BE NEEDED THU
NIGHT...ESPECIALLY OVER THE KEWEENAW WHERE MORE PERSISTENT SYNOPTIC
SNOW AND LAKE ENHANCEMENT OCCURS...THEN ON FRI/FRI NIGHT FOR WESTERN
AND NORTH CENTRAL UPPER MICHIGAN FOR THE LAKE ENHANCED SNOW.
SNOWFALL FOR ALL OF THESE AREAS MAY REACH THE 6 TO 8 INCH RANGE FOR
24 HOURS THU NIGHT THROUGH FRI. GUSTY WINDS WILL ALSO RESULT IN
BLSN...ESPECIALLY NEAR LK SUPERIOR ON FRI. WILL CONTINUE TO MENTION
IN THE HAZARDOUS WEATHER OUTLOOK.
INTO THE WEEKEND...PERSISTENCE WILL BE THE STORY. COLD AIR CONTINUES
TO FILTER FM CENTRAL CANADA ACROSS WESTERN GREAT LAKES. H85 TEMPS
SHOULD FALL BLO -20C ON SAT AND MAYBE AS LOW AS -24C ON SUN. AT THE
SFC...SHOULD SEE TEMPS IN THE 20S ON FRI FALL OFF INTO THE TEENS FRI
NIGHT INTO SAT THEN TUMBLE BACK DOWN INTO THE SINGLE DIGITS ABOVE
ZERO BY LATE SAT AFTN AND DOWN BLO ZERO SAT NIGHT...AT LEAST FOR THE
WEST INTERIOR. READINGS WILL STRUGGLE TO RISE ABOVE ZERO OVER FAR
WEST ON SUN. OVERALL THE AIRMASS OVER THE AREA WILL BE MODIFIED BY
LAKE SUPERIOR SINCE SFC RIDGE STAYS WELL TO THE WEST FM NORTHERN
CANADA TO THE NORTHERN PLAINS WHILE STRONG SFC LOW AFFECTS EAST
COAST. LAKE INDUCED TROUGH IS EXPECTED TO LINGER ACROSS MUCH OF THE
GREAT LAKES...REINFORCED BY STRONGER UPPER LOW DIVING ACROSS THE
GREAT LAKES WHICH WILL INTENSIFY THE BROAD TROUGHING ACROSS THE
GREAT LAKES. PREVIOUS SHIFT HAD LIKELY POPS FOR THE LAKE EFFECT
THROUGH THE WEEKEND FOR AREAS FAVORED BY NW WINDS. BASED ON LATEST
MODELS SAW NO REASON TO STRAY FM THOSE HIGHER POPS COMPARED TO LOWER
POPS THAT CONSENSUS OF THE MODELS GAVE. PURE LAKE EFFECT SETUP IS
TYPICALLY A TIME WHERE CONSENSUS POPS FM THE COARSER MODELS WILL
FALL SHORT.
COLD PATTERN WITH NW FLOW LAKE EFFECT BEGINS TO BREAK DOWN EARLY
NEXT WEEK. KEPT HIGHER POPS FOR AREAS FAVORED BY NW WINDS THROUGH
MON AND MON NIGHT THEN SHIFTED BACK TO CONSENSUS POPS AS TROUGHING
BEGINS TO RELAX. OVERALL LOOKS LIKE WARMING TREND WILL START UP OR
AT LEAST TEMPS WILL PUSH UP TO NEAR NORMAL. THOUGH LAKE EFFECT WILL
BE ON THE DECLINE...MAY BE WEAK WAVE IN FLATTENING FLOW ALOFT THAT
WOULD BRING SWATH OF LGT SNOW TO UPPER GREAT LAKES BY NEXT WED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1157 PM EST WED JAN 13 2016
MVFR CONDITIONS WILL PREVAIL AT KIWD AND KCMX INTO THU AFTERNOON. AT
KSAW...VFR CONDITIONS SHOULD PREVAIL INTO THU AFTERNOON. BY LATE THU
AFTERNOON...LIGHT SNOW MOVES IN WITH THE NEXT SYSTEM AND CONDITIONS
WILL DETERIORATE TO IFR/LOW MVFR AT ALL SITES.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 327 AM EST THU JAN 14 2016
A SURFACE LOW IN THE NORTHERN PLAINS WILL MOVE INTO SOUTHERN
WISCONSIN TONIGHT BEFORE STRENGTHENING AND MOVING NORTHEAST AND
OVER LAKE HURON BY FRIDAY EVENING. AS THE LOW MOVES TO THE SOUTH OF
THE AREA...EXPECT WINDS TO SHIFT TO THE EAST TODAY AND NORTHEAST BY
FRIDAY MORNING BEFORE CONTINUING TO BACK TO THE NORTHWEST BY FRIDAY
NIGHT. AT THIS POINT...EXPECT WIND GUSTS UP TO 30KTS AS THE LOW
MOVES THROUGH. BEHIND THE LOW...ANOTHER SURGE OF COLD AIR WILL MOVE
OVER THE UPPER GREAT LAKES REGION AND LEAD TO THE POTENTIAL FOR
HEAVY FREEZING SPRAY BY SUNDAY (AND CONTINUE INTO MONDAY). THE
NORTHWESTERLY WINDS WILL BE PERSISTENT THROUGH THE WEEKEND UP TO
30KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...JLA
AVIATION...07
MARINE...SRF
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1205 AM EST THU JAN 14 2016
.AVIATION...
ALL INDICATIONS ARE THE LAST OF THE WIDESPREAD LIGHT SNOW WILL PUSH
EAST OF THE AREA BY THE START OF THE TAF PERIOD. THE STRONGEST
ACTIVITY OVER WESTERN LOWER HAD A LAKE ENHANCEMENT COMPONENT TO WHAT
WAS RATHER GOOD UPPER LEVEL JET DYNAMICS. DESPITE THE LOSS IN LARGER
SCALE FORCING...SUPERSATURATION WITH RESPECT TO ICE WILL REMAIN
FAIRLY HIGH THROUGH ABOUT 10-11Z. THE CONNECTION WILL NOT BE AS
CLEAN TO THE DGZ...AND AS A RESULT THE IDEA IS THAT FLURRIES WILL BE
ABLE TO HOLD ON BUT ACCUMULATION EFFICIENCY WILL LOWER. MIDLEVEL
DEFORMATION AXIS AND FRONTAL BOUNDARY WILL LIFT NORTHWARD TOMORROW
AS A WARM FRONT. FORCING ALONG THIS BOUNDARY WILL SUPPORT MVFR TO
VFR CIGS. A BRIEF PERIOD OF RIDGING WILL LIFT INTO SEMICH WHICH
SHOULD AT LEAST PROVIDE SOME DRYING. THUS...CONFIDENCE IS LOW ON ANY
LOWER CIG FORMATION.
AT DTW...WIDESPREAD LIGHT SNOW TO END AT THE START OF THE PERIOD
WITH SOME FLURRIES CONTINUING THROUGHOUT MUCH OF THE NIGHT.
EXPECTING SOME CIGS TO RISE ABOVE 5000 FT THURSDAY...LOW CONFIDENCE
ON WHEN THAT WILL OCCUR. DID INTRODUCE A MENTION OF FREEZING DRIZZLE
AFTER 06Z FRIDAY...CONFIDENCE ON OCCURRENCE IS LOW-
MEDIUM...CONFIDENCE ON TIMING IS VERY LOW.
//DTW THRESHOLD PROBABILITIES...
* HIGH CONFIDENCE THAT PRECIPITATION TYPE WILL BE SNOW.
* HIGH CONFIDENCE THAT CEILINGS WILL REMAIN BELOW 5000 FEET THROUGH
TONIGHT. MEDIUM CONFIDENCE IN CIGS BELOW 5000 FT BY LATE MORNING
THURSDAY.
* MEDIUM CONFIDENCE IN FREEZING DRIZZLE TONIGHT. LOW CONFIDENCE IN
TIMING.
&&
.PREV DISCUSSION...ISSUED 848 PM EST WED JAN 13 2016
UPDATE...
BEST REFLECTIVITY OVER THE PAST 1-1.5 HRS HAS ALIGNED OVER THE
CENTRAL CWA THROUGH PORTIONS OF FLINT DOWN TO PONTIAC AND THE
NORTHEASTERN DETROIT SUBURBS. ALL INDICATIONS ARE THIS LIGHT SNOW
IS MAXIMIZING ITS POTENTIAL ON THE COLD SIDE OF A DECENT 850-700
MB THERMAL BOUNDARY NOW PUSHING INTO SOUTHERN LOWER MICHIGAN.
RADAR TIME-MATCHING WITH LIMITED REPORTS DOES SUPPORT THE IMPULSE
OF VERY FLEETING 25-30 DBZ THAT PUSHED DOWN FROM FLINT THROUGH THE
PONTIAC AREA WAS SUPPORTING AN INCH PER HOUR RATES. THE BEST
ACTIVITY/MOST FAVORABLE MICROPHYSICS AND FLAKE SIZE SEEMS TO
REQUIRE BETTER DEFINED/DEEPER MOISTURE SURGES/IMPULSES WORKING
ALONG AND PARALLEL TO THE INBOUND THERMAL GRADIENT. HAVE SEEN AN
EPISODIC/CYCLE BEHAVIOR TO PRECIPITATION SO FAR. MOVING
FORWARD...CONSENSUS OF HIRES OUTPUT HAS NOT BEEN TOO TERRIBLY
USEFUL WITH ITS DEFINITION...BUT THE GENERAL IDEA IS THE
WIDESPREAD COVERAGE OF LIGHT SNOW WILL CONTINUE THROUGH ABOUT
04Z...BEFORE EXITING TO THE EAST. THE ITEM TO WATCH FOR IS WHEN
EXACTLY THE WEST EDGE OF ACTIVITY WORKS OFF OF LAKE MICHIGAN. SOME
OUTPUT SUGGESTS THE LAKE MICHIGAN/WEST MICHIGAN PRECIPITATION
WILL FALL APART BY THE TIME IT ARRIVES.
STILL LOOKING AT A RANGE OF .5 TO 1 INCH IN MANY AREAS. SOME
LOCATIONS IN THE FLINT TO PONTIAC CORRIDOR COULD SEE UPWARDS OF +2
INCHES WHEN ITS ALL DONE.
PREV DISCUSSION...ISSUED 342 PM EST WED JAN 13 2016
DISCUSSION...
WIDESPREAD LIGHT SNOW IS ONGOING FROM MINNESOTA TO LOWER MICHIGAN AT
PRESS TIME IN ASSOCIATION WITH A COUPLE OF WEAK SHORTWAVES THAT ARE
BEING STEERED SOUTHEAST ACROSS THE GREAT LAKES AT PRESS TIME. THE
FIRST WAVE IN THE SEQUENCE HAS ELICITED A HEALTHY RESPONSE OF WARM
ADVECTION ALOFT AND A 40+KT LLJ THAT IS MODELED TO GRADUALLY
STRENGTHEN THROUGH THIS EVENING. THIS WILL PROVIDE A FOCUS FOR LIGHT
TO OCCASIONALLY MODERATE SNOWFALL MAINLY SOUTH OF THE M59 CORRIDOR
FOR THE NEXT FEW HOURS. THE SECOND WAVE IS EMBEDDED WITHIN THE LEFT
EXIT OF THE JET CENTERED OVER NORTHERN MINNESOTA AND WILL TRAIL THE
LEAD WAVE BY ONLY A FEW HOURS. WEAK DYNAMIC FORCING WILL CENTER
FURTHER NORTH POST-00Z AS MOIST ISENTROPIC ASCENT PROVIDES THE
PRIMARY FORCING THROUGH 03-04Z. THE CEILING ON AMOUNTS IS QUITE LOW
AS OVERALL PERIOD OF SNOW WILL BE SHORT LIVED...MAINLY AN INCH OR
LESS. HOWEVER, THERE IS SOME MINOR OVERACHIEVING POTENTIAL GIVEN A
FAVORABLE THERMODYNAMIC PROFILE FEATURING A SFC-650MB DGZ THAT
IS SHOWN BY THE RAP TO SUPERSATURATED UP TO 110%+ WRT ICE AT TIMES.
SECOND CONCERN WILL SHOW ITSELF IN THE NEXT HOUR OR TWO, AND THAT IS
THE POTENTIAL FOR LAKE EFFECT TO BECOME ESTABLISHED OVER MIDLAND/BAY
COUNTIES WITHIN FAVORABLY UNSTABLE LAKE MICHIGAN PLUME. MADE NO
CHANGES TO THE AFTERNOON UPDATE WHICH CARRIED AMOUNTS OF AROUND 2"
HERE. BACKING LOW-LEVEL FLOW IN THE 0-1KM LAYER WILL QUICKLY END ANY
LES POTENTIAL AFTER 00Z. WARMING OF THE COLUMN, INCLUDING SFC TEMPS
RISING INTO THE LOW/MID 20S, WILL LIFT THE EFFECTIVE DGZ INTO THE
DRY LAYER ALOFT AND END ANY LINGERING FLURRY POTENTIAL BY MORNING.
ATTENTION THEN TURNS TO THE LATE WEEK SYSTEM WHICH WILL TAKE PLACE
IN TWO PHASES. THE FIRST WILL BE ON THURSDAY WHEN THE DEPARTURE OF
TONIGHT`S TROUGH AXIS ALLOW THE AFOREMENTIONED JET CENTERED OVER
MINNESOTA TO ALIGN ZONALLY AS UPSTREAM RIDGING BUILDS IN ADVANCE OF
ENERGY EMERGING OVER THE FRONT RANGE OF THE ROCKIES. THIS WILL FORCE
A PERIOD OF PROLONGED WAA/ISENTROPIC ASCENT FUELED BY RIGHT ENTRANCE
DYNAMICS THURSDAY INTO THURSDAY NIGHT. MARGINALLY FAVORABLE
MICROPHYSICS AND GENERALLY WEAK ASCENT WILL FAVOR JUST LIGHT SNOW
ACCUMULATIONS (HALF INCH OR LESS) NORTH OF I-69 DURING THE DAYTIME
HOURS BEFORE MID-LEVEL RIDGING DRIES THE MID AND UPPER LEVELS.
SECOND PHASE OF THE SYSTEM WILL BE THE PASSAGE OF THE LOW OVER
NORTHERN LOWER MICHIGAN THURSDAY NIGHT THROUGH FRIDAY. WITH THE DEEP
SUBSIDENCE-INDUCED DRY LAYER IN PLACE TO BEGIN THURSDAY NIGHT,
DEVELOPING WARM ADVECTION IN THE LOW-LEVELS WILL LIKELY LEAD TO
WIDESPREAD DRIZZLE. UNTIL CONFIDENCE IS HIGHER, INCLUDED A
FLURRIES/DRIZZLE MENTION. HOWEVER, IF UPSTREAM OBSERVATIONS CONFIRM
MODEL SUGGESTIONS OF DRIZZLE POTENTIAL, THE FLURRIES EFFECTIVELY
BECOME THE PLACEHOLDER IN THE FORECAST FOR FREEZING DRIZZLE, WHICH
COULD LAST FOR SEVERAL HOURS NORTH OF M-59.
RAIN ASSOCIATED WITH COLD FROPA WILL SWEEP ACROSS THE CWA ON FRIDAY
AFTERNOON, ALTHOUGH ONGOING PHASING WITH A POTENT PIECE OF
SUBTROPICAL ENERGY OVER THE MID-ATLANTIC DOES YIELD INCREASED
UNCERTAINTY WITH REGARD TO MOISTURE AND TIMING EVEN FOR SOUTHEAST
MICHIGAN ON FRIDAY. TEMPERATURES WILL REMAIN SEASONABLE, RISING INTO
THE 30S AND THEN NEAR 40 ON THURSDAY AND FRIDAY.
A RETURN TO FRIGID TEMPERATURES AND LAKE EFFECT SNOW SHOWER ACTIVITY
IS LIKELY FOR THE WEEKEND. THIS WILL OCCUR AS A CLOSED UPPER LOW AND
ASSOCIATED POCKET OF COLD AIR /-20C AT 850 MB/ MIGRATES ACROSS THE
GREAT LAKES. THE BEST CHANCE FOR SNOW SHOWER ACTIVITY WILL BE
ACCOMPANIED BY LOBES OF VORTICITY ROTATING THROUGH TO ADD SYNOPTIC
SUPPORT TO LAKE EFFECT ACTIVITY...TIMING AT THIS POINT FAVORS
SATURDAY NIGHT AND SUNDAY...ALTHOUGH SNOW SHOWERS WILL LIKELY BE
AROUND IN SOME FASHION THE ENTIRE WEEKEND. NORTHWEST FLOW AND
SURFACE HIGH PRESSURE WILL RESULT IN LESS CLOUDS AND SNOW SHOWERS AS
WELL AS SLIGHTLY MILDER TEMPERATURES TUESDAY AND WEDNESDAY.
MARINE...
LOW PRESSURE WILL TRACK OVER THE NORTHERN GREAT LAKES
TONIGHT...BRINGING A CHANCE OF SNOW TO THE REGION. A BRIEF BREAK
WILL FOLLOW ON THURSDAY AS HIGH PRESSURE TRIES TO BUILD INTO THE
SOUTHERN GREAT LAKES. THE NEXT LOW PRESSURE SYSTEM ARRIVES FROM THE
WEST ON THURSDAY NIGHT AND FRIDAY. THIS LOW WILL CONTINUE TO DEEPEN
AS IT TRACKS OVER THE GREAT LAKES RESULTING IN INCREASING WINDS ON
FRIDAY NIGHT AND INTO SATURDAY. WIND GUSTS OVER LAKE HURON COULD
REACH GALE CRITERIA AND THEREFORE...A GALE WATCH HAS BEEN ISSUED FOR
THIS TIMEFRAME.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...GALE WATCH FROM FRIDAY EVENING THROUGH SATURDAY AFTERNOON FOR
LHZ361>363-441-462-463.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....DG
UPDATE.......CB
DISCUSSION...JVC/DT
MARINE.......RK
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1158 PM EST WED JAN 13 2016
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 450 PM EST WED JAN 13 2016
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW TROF OVER SE CANADA AND
THE ERN CONUS...ANCHORED BY MID/UPPER LEVEL LOW CENTERED IN THE
VCNTY OF JAMES BAY. IN THE NW FLOW...SHORTWAVE DROPPING SE THRU NW
WI HAS GENERATED SOME -SN THAT IS MOVING ACROSS FAR WRN LAKE
SUPERIOR/NW WI AND PORTIONS OF W AND CNTRL UPPER MI. MEANWHILE...
WITH LATEST RAP ANALYSIS SHOWING 850MB TEMPS AROUND -20C OVER LAKE
SUPERIOR...LES CONTINUES AS WELL. BOUNDARY LAYER WINDS BACKED MORE
THAN EXPECTED LAST NIGHT...RESULTING IN THE CONVERGENCE ZONE AND
ASSOCIATED MDT/HVY SNOW BAND OVER WRN LAKE SUPERIOR INTO NW UPPER MI
LIFTING FARTHER N THAN PLANNED. THAT CONVERGENCE ZONE AND HVY SNOW
BAND IS STILL OVER THE LAKE AND KEWEENAW...CURRENTLY BTWN HOUGHTON
AND CALUMET AS OF 21Z.
WITH THE PASSING OF THE AFOREMENTIONED SHORTWAVE...THE CONVERGENCE
ZONE ACROSS THE KEWEENAW HAS BEEN DRIFTING S THIS AFTN. THE
SOUTHWARD DRIFT WILL CONTINUE...BUT THE CONVERGENCE WILL GRADUALLY
WEAKEN AS LOW-LEVEL WIND FIELD DIMINISHES UNDER WEAKENING PRES
GRADIENT ACROSS THE AREA. AS A RESULT...ONGOING HVY SNOW BAND WILL
DRIFT S OVER THE NEXT SEVERAL HRS...BUT OVERALL INTENSITY OF SNOW
WILL DIMINISH WITH TIME. OPTED TO KEEP LES ADVY FOR NRN HOUGHTON
COUNTY GOING UNTIL SCHEDULED EXPIRATION AT 00Z DUE TO HIGH SNOWFALL
RATES LIKELY ON THE ORDER OF 1-2IN/HR. SNOWFALL SHOULD BE LIGHTER BY
THE TIME IT REACHES ONTONAGON COUNTY IN A FEW HRS. MAY SEE A COUPLE
OF INCHES OF SNOW THERE THIS EVENING. TO THE E...SHORTWAVE COMBINED
WITH REFOCUSING OF CONVERGENCE HAS LED TO LES INCREASING IN
ORGANIZATION/INTENSITY OVER ERN LAKE SUPERIOR OVER THE LAST HR OR
SO. LOOKS LIKE THERE WILL BE ENOUGH NORTHERLY WIND PUSH ACROSS THE
LAKE TO SHIFT THE LES BACK INTO THE NE FCST AREA THIS EVENING. HAVE
PAINTED 2-3 INCHES OF SNOW ACCUMULATION NEAR THE SHORE FROM JUST E
OF MUNISING EASTWARD. ELSEWHERE...-SN/FLURRIES WILL END IN THE NEXT
FEW HRS...AND MAY SEE SOME CLEARING AWAY FROM DIMINISHING LES.
INTERIOR CNTRL HAS BEST CHC OF SEEING AT LEAST SOME PARTIAL CLEARING
FOR A WHILE. LOWERED TEMPS TOWARD THE LOWER END OF AVBL GUIDANCE
(BIAS CORRECTED CANADIAN MODELS)...RESULTING IN MINS A FEW DEGREES
BLO 0F. WITH LIGHT/CALM WINDS...WOULDN`T TAKE MUCH CLEARING OR A
VERY LONG DURATION OF MOSTLY CLEAR TO SEE TEMPS PLUNGE TO -10 TO
-15F OR LWR IN TRADITIONAL COLD SPOTS.
ON THU...ATTENTION TURNS TO SHORTWAVE TROF MOVING OUT OVER THE
NRN/CNTRL PLAINS. IN RESPONSE...WAA/ISENTROPIC ASCENT REGIME
DEVELOPS DOWNSTREAM INTO THE UPPER GREAT LAKES AS SHOWN BEST ON 285K
AND ESPECIALLY 290K SFC. WITH ADDITION TO SOME UPPER DIVERGENCE
PROVIDED BY THE RIGHT ENTRANCE OF UPPER JET AS WELL AS LOW/MID LEVEL
FGEN...EXPECT A BAND OF -SN TO STREAK OUT ACROSS THE NRN PLAINS INTO
THE UPPER GREAT LAKES...AFFECTING UPPER MI MAINLY IN THE AFTN HRS.
12Z CANADIAN MODELS/GFS AND ECMWF WERE IN VERY GOOD AGREEMENT ON
THIS SCENARIO. 12Z NAM WAS MUCH SLOWER IN NE PROGRESS OF PCPN...AND
THE NCEP HIGH RES WRF-NMM WAS A COMPLETE OUTLIER IN ONLY BRUSHING
THE FAR SCNTRL FCST AREA WITH PCPN THU NIGHT. 18Z NAM CAME IN LINE
WITH THE GFS/ECMWF/CANADIAN MODELS WHICH WERE USED AS THE BASIS FOR
FCST. RAISED POPS INTO THE LIKELY RANGE FOR AT LEAST A TIME FOR
NEARLY ALL OF THE FCST AREA THU AFTN. ALTHOUGH 290K SFC SHOWS MIXING
RATIOS OF UP TO 3G/KG AVBL...ASCENT IS NOT ESPECIALLY STRONG AND
SNOW TO WATER RATIOS WILL BE ON THE ORDER OF 15-1. FOR NOW...EXPECT
SNOW ACCUMULATIONS TO BE AROUND 1 INCH W AND ONE-HALF INCH E THU
AFTN.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 352 PM EST WED JAN 13 2016
...WIDESPREAD SNOW THU NIGHT INTO FRI WITH N/NW FLOW LAKE EFFECT
INTO THE WEEKEND...
TROUGHING ALOFT OVER EAST HALF OF CANADA WITH ADDITIONAL TROUGHING
EXPANDING FM CENTRAL CONUS TO EASTERN CONUS THIS WEEKEND. COLDER
CONDITIONS SHOULD MODERATE EARLY NEXT WEEK AS TROUGH AXIS MOVES TO
EASTERN CANADA AND HEIGHTS BEGIN RISING FM WESTERN CONUS TO GREAT
LAKES.
SHORTWAVE TROUGH CROSSING THE CENTRAL PLAINS ON THU NIGHT ALONG WITH
WEAKER LOW PRESSURE SYSTEM AROUND 1000MB WILL SPREAD LIGHT SNOW FM
NORTHERN MN INTO NORTHERN WI/UPPER MICHIGAN DUE TO ISENTROPIC ASCENT
AND WARM AIR ADVECTION WELL TO NORTH OF SFC WARM FRONT FM UPPER
MISSISSIPPI RIVER VALLEY TO LOWER GREAT LAKES. SNOW MAY BE ENHANCED
BY RIGHT ENTRANCE FORCING FM JET STREAK FM NW ONTARIO TO NEW ENGLAND.
MOST PERSISTENT SNOW FM THE SYSTEM ON THU NIGHT WILL BE OVER
KEWEENAW AND LAKE SUPERIOR. EASTERLY WINDS AHEAD OF APPROACHING SFC
LOW AND H85 TEMPS DOWN NEAR -10C WILL RESULT IN LAKE ENAHANCEMENT.
DGZ IS NARROW AND QUITE ELEVATED ABOVE H7 SO SLR/S AT LEAST FOR THU
NIGHT SHOULD HOLD IN THE 10-15:1 RANGE INSTEAD IN THE FLUFFIER 20:1
RANGE THAT WILL MOVE IN FOR FRI AND BEYOND.
BY FRI MORNING TROUGH ALOFT WILL BE ENTERING WESTERN GREAT LAKES
WHILE SFC LOW DEEPENS TO AROUND 997MB OVER NORTHERN LK MICHIGAN. LOW
CONTINUES TO DEEPEN TO 992MB BY FRI EVENING OVER NORTHERN LK
HURON/GEORGIAN BAY. THOUGH LARGER SCALE FORCING FM THE SHORTWAVE IN
TERMS OF DEEP LAYER Q-VECTOR CONVERGENCE DIMINISHES FROM WEST TO
EAST ON FRI...THE SHORTWAVE TROUGH/LOWER HEIGHTS IN THE VCNTY AND
WELL DEVELOPED COLD CONVEYOR BELT OF DEEPER MOISTURE THROUGH H7/H85-
H7 FRONTOGENESIS ACROSS MUCH OF NORTH HALF OF UPPER MICHIGAN SHOULD
KEEP LIGHT SNOW GOING OVER MOST OF CWA. SNOW WILL FALL MODERATE TO
POSSIBLY HEAVY NEAR LK SUPERIOR DUE TO LAKE ENHANCEMENT AND UPSLOPE
LIFT AS CYCLONIC NORTH/NORTHEAST WINDS ON BACK SIDE OF DEEPENING LOW
DRAW COLDER AIR INTO REGION WITH H85 TEMPS DROPPING BLO -10C.
PRELIMINARY INDICATIONS SUGGEST ADVISORIES WOULD BE NEEDED THU
NIGHT...ESPECIALLY OVER THE KEWEENAW WHERE MORE PERSISTENT SYNOPTIC
SNOW AND LAKE ENHANCEMENT OCCURS...THEN ON FRI/FRI NIGHT FOR WESTERN
AND NORTH CENTRAL UPPER MICHIGAN FOR THE LAKE ENHANCED SNOW.
SNOWFALL FOR ALL OF THESE AREAS MAY REACH THE 6 TO 8 INCH RANGE FOR
24 HOURS THU NIGHT THROUGH FRI. GUSTY WINDS WILL ALSO RESULT IN
BLSN...ESPECIALLY NEAR LK SUPERIOR ON FRI. WILL CONTINUE TO MENTION
IN THE HAZARDOUS WEATHER OUTLOOK.
INTO THE WEEKEND...PERSISTENCE WILL BE THE STORY. COLD AIR CONTINUES
TO FILTER FM CENTRAL CANADA ACROSS WESTERN GREAT LAKES. H85 TEMPS
SHOULD FALL BLO -20C ON SAT AND MAYBE AS LOW AS -24C ON SUN. AT THE
SFC...SHOULD SEE TEMPS IN THE 20S ON FRI FALL OFF INTO THE TEENS FRI
NIGHT INTO SAT THEN TUMBLE BACK DOWN INTO THE SINGLE DIGITS ABOVE
ZERO BY LATE SAT AFTN AND DOWN BLO ZERO SAT NIGHT...AT LEAST FOR THE
WEST INTERIOR. READINGS WILL STRUGGLE TO RISE ABOVE ZERO OVER FAR
WEST ON SUN. OVERALL THE AIRMASS OVER THE AREA WILL BE MODIFIED BY
LAKE SUPERIOR SINCE SFC RIDGE STAYS WELL TO THE WEST FM NORTHERN
CANADA TO THE NORTHERN PLAINS WHILE STRONG SFC LOW AFFECTS EAST
COAST. LAKE INDUCED TROUGH IS EXPECTED TO LINGER ACROSS MUCH OF THE
GREAT LAKES...REINFORCED BY STRONGER UPPER LOW DIVING ACROSS THE
GREAT LAKES WHICH WILL INTENSIFY THE BROAD TROUGHING ACROSS THE
GREAT LAKES. PREVIOUS SHIFT HAD LIKELY POPS FOR THE LAKE EFFECT
THROUGH THE WEEKEND FOR AREAS FAVORED BY NW WINDS. BASED ON LATEST
MODELS SAW NO REASON TO STRAY FM THOSE HIGHER POPS COMPARED TO LOWER
POPS THAT CONSENSUS OF THE MODELS GAVE. PURE LAKE EFFECT SETUP IS
TYPICALLY A TIME WHERE CONSENSUS POPS FM THE COARSER MODELS WILL
FALL SHORT.
COLD PATTERN WITH NW FLOW LAKE EFFECT BEGINS TO BREAK DOWN EARLY
NEXT WEEK. KEPT HIGHER POPS FOR AREAS FAVORED BY NW WINDS THROUGH
MON AND MON NIGHT THEN SHIFTED BACK TO CONSENSUS POPS AS TROUGHING
BEGINS TO RELAX. OVERALL LOOKS LIKE WARMING TREND WILL START UP OR
AT LEAST TEMPS WILL PUSH UP TO NEAR NORMAL. THOUGH LAKE EFFECT WILL
BE ON THE DECLINE...MAY BE WEAK WAVE IN FLATTENING FLOW ALOFT THAT
WOULD BRING SWATH OF LGT SNOW TO UPPER GREAT LAKES BY NEXT WED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1157 PM EST WED JAN 13 2016
MVFR CONDITIONS WILL PREVAIL AT KIWD AND KCMX INTO THU AFTERNOON. AT
KSAW...VFR CONDITIONS SHOULD PREVAIL INTO THU AFTERNOON. BY LATE THU
AFTERNOON...LIGHT SNOW MOVES IN WITH THE NEXT SYSTEM AND CONDITIONS
WILL DETERIORATE TO IFR/LOW MVFR AT ALL SITES.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 450 PM EST WED JAN 13 2016
NO GALES ARE EXPECTED THRU THIS WEEKEND. MUCH OF THE TIME...WINDS
WILL BE IN THE 15-25KT OR 20-30KT RANGE. WINDS WILL BE LIGHTEST LATE
TONIGHT/THU MORNING...MOSTLY UNDER 15KT. A SURGE OF ARCTIC AIR THIS
WEEKEND WILL BRING A RETURN OF MORE SIGNIFICANT FREEZING SPRAY AS
WELL.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...07
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS DULUTH MN
1202 AM CST THU JAN 14 2016
.UPDATE...
ISSUED AT 921 PM CST WED JAN 13 2016
CLEAR SKIES AND VERY COLD TEMPERATURES CONTINUE OVER THE BORDER
REGION WITH 3Z TEMPS FROM 15 TO 19 BELOW ZERO. WE UPDATED EARLIER
TO LOWER THESE TEMPS QUITE A BIT AND MAY HAVE TO BUMP DOWN A FEW
MORE DEGREES AS IT WILL TAKE SOME TIME FOR THE CLOUDS TO MOVE IN.
ANOTHER CONCERN IS A NEARLY STATIONARY BAND OF SNOW OVER THE
WESTERN TIP OF LAKE SUPERIOR. THIS DRIVEN BY LOW LEVEL CONVERGENT
WIND AND COLD LOW LEVEL TEMPERATURES. THE RAP AND NAM BOTH SHOW
EITHER LIGHT VERY LOW LEVEL WIND OR THE CONVERGENCE TO CONTINUE
THROUGH LATE TONIGHT...THEN THE SURFACE TO 925MB WIND BECOMES
EASTERLY WHICH WILL BRING SNOW WEST TO THE TWIN PORTS AND ALONG
THE NORTH SHORE AS FAR NORTH AS LITTLE MARAIS. WE INCREASED POPS
LATE TONIGHT IN THESE AREAS AND PUT SOME LIGHT SNOW ACCUMULATION
IN THROUGH 12Z. WE ALSO BUMPED UP SNOW AMOUNTS SOME IN THESE SAME
AREAS DUE TO A BETTER CHANCE FOR LAKE ENHANCED SNOWFALL. WE WILL
WAIT FOR THE REST OF THE GUIDANCE TO COME IN...BUT THERE MAY BE A
NEED FOR AT LEAST AN ADVISORY ALONG THE NORTH SHORE...POSSIBLY
DOWN TO THE TWIN PORTS.
UPDATE ISSUED AT 727 PM CST WED JAN 13 2016
WE UPDATED TO LOWER TEMPERATURES ALONG THE INTERNATIONAL BORDER.
INTERNATIONAL FALLS WAS ALREADY AT -15F. CLEAR SKIES HAVE LED TO
THE COLD TEMPERATURES AND A TIGHT GRADIENT EXISTS WITH BIGFORK AT
9 ABOVE. CLOUDS WILL GRADUALLY INCREASE OVERNIGHT AND SOME AREAS
WILL SEE THESE COLD TEMPERATURES RISE AS THE CLOUDS THICKEN.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 332 PM CST WED JAN 13 2016
AT 330 PM...THE LIGHT SNOW THAT MOVED THROUGH DURING THE DAY WAS
STARTING TO MOVE OFF TO THE SOUTHEAST. THE MAJORITY OF THE LIGHT
SNOW AT THIS POINT WAS CONFINED TO AREAS FROM THE IRON RANGE
SOUTHEASTWARD INTO NW WI. THE SNOW HAD DIMINISHED CONSIDERABLY AT
THIS TIME IN THE DULUTH AREA...WITH MAINLY FLURRIES REMAINING.
TEMPERATURES RANGED FROM SINGLE DIGITS BELOW ZERO IN THE TIP OF
THE ARROWHEAD...TO THE SINGLE DIGITS AND TEENS FURTHER SOUTH.
THE MAIN FOCUS FOR THIS EVENING WILL BE THE LIGHT SNOW ACROSS
PORTIONS OF THE REGION. SOME ADDITIONAL LIGHT SNOW ACCUMULATION
WILL BE POSSIBLE INTO THE EVENING COMMUTE ACROSS MAINLY NW WI.
MAINLY FLURRIES ARE EXPECTED ELSEWHERE. AMOUNTS HAVE GENERALLY
BEEN AN INCH OR LESS ACROSS THE REGION. THE WEAK SHORTWAVE AND
SURFACE LOW THAT CAUSED THE SNOW WILL CONTINUE TO MOVE OFF TO THE
SE OVERNIGHT. THE FOCUS WILL THEN SHIFT TO THE MORE SUBSTANTIAL
SYSTEM THAT WILL MOVE IN LATER TONIGHT AND ON THURSDAY.
A CLIPPER TYPE SYSTEM WILL MOVE FROM SOUTHERN ALBERTA THIS
EVENING...TO CENTRAL NORTH DAKOTA BY 12Z THURSDAY...AND FAR SOUTH
CENTRAL MN BY 00Z FRIDAY. STRONG WAA...FGEN AND FAVORABLE JET
DYNAMICS WILL ACCOMPANY UPPER LEVEL DYNAMIC SUPPORT...TO GENERATE
A WEST TO EAST BAND OF SNOW ACROSS CENTRAL MN AND NORTHERN WI
LATER TONIGHT. THIS BAND WILL THEN SHIFT FURTHER NORTH ACROSS THE
CWA ON THURSDAY. AT THIS POINT...THERE IS PRETTY GOOD MODEL
AGREEMENT THAT QPF AMOUNTS WILL BE SOMEWHERE IN THE 0.15 TO 0.25
INCH RANGE FOR THE COMBINED EVENT. AS A RESULT...WE ARE EXPECTING
SNOWFALL AMOUNTS OF UP TO 2 INCHES ON THURSDAY...AND 2 TO 5 INCHES
FOR THE COMBINED EVENT THROUGH FRIDAY. DUE TO THE ORIENTATION OF
THE PATH OF THE SURFACE LOW AND THE UPPER LEVEL SHORTWAVE...WOULD
NOT BE SURPRISED TO SEE A VERY NARROW BAND OF HIGHER SNOW
ACCUMULATION...BUT CONFIDENCE IN PLACEMENT OF A HEAVIER BAND WOULD
BE QUITE LOW AT THIS POINT. AS WE GET CLOSER...WE MAY NEED TO
ISSUE AN ADVISORY IF CONFIDENCE INCREASES REGARDING A POTENTIALLY
HIGHER BAND OF SNOWFALL AMOUNTS.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 332 PM CST WED JAN 13 2016
THE LARGE-SCALE PATTERN CHANGES THIS WEEKEND WITH ONE LAST ROUND OF
ARCTIC AIR AS THE UPPER LOW WHICH HAS BEEN NEAR STATIONARY OVER
HUDSON BAY DRIFTS TOWARDS THE GREAT LAKES...WITH TEMPS MODERATING TO
NEAR NORMAL NEXT WEEK. BESIDES A STORM EXITING THE REGION THURSDAY
NIGHT PRECIPITATION THROUGH THE EXTENDED PERIOD WILL BE LIMITED TO
THE SOUTH SHORE OF LAKE SUPERIOR WHERE LAKE EFFECT SNOWFALL IS
EXPECTED TO PERSIST INTO EARLY NEXT WEEK.
ON THE SYNOPTIC SCALE THE UPPER LOW WHICH HAS BEEN OVER HUDSON BAY
FOR THE PAST 5 DAYS WILL EVENTUALLY MAKE ITS WAY SOUTH ALONG THE
NORTHWEST ONTARIO/MANITOBA BORDER AND ACROSS THE UPPER GREAT LAKES
SATURDAY INTO SUNDAY...BRINGING WITH IT ANOTHER ROUND OF ARCTIC
TEMPERATURES. IT LOOKS LIKE THIS WILL BE SIMILAR TO THE PAST TWO
ROUNDS OF ARCTIC TEMPS WITH 850MB TEMPS IN THE -25 TO -30 RANGE.
CANADIAN IS A COLD OUTLIER WITH 850MB TEMPS BELOW -30...AND THE GEFS
ENSEMBLE MEAN SLIGHTLY WARMER...BUT THE ECMWF AND GFS MATCH UP
PRETTY WELL IN THE MIDDLE. THE COLDEST TEMPS ALOFT AND AT THE
SURFACE WILL OCCUR SATURDAY NIGHT...BUT LUCKILY WITH THE LOW WILL
COME MID-LEVEL CLOUD COVER WHICH WILL LIMIT LOWS TO ONLY THE 10-20
BELOW ZERO RANGE INSTEAD OF POSSIBLY COLDER IF SKIES WERE CLEAR.
BOTH AHEAD OF THIS UPPER LOW AND ITS WAKE NEXT WEEK FLOW AT LOW TO
MID LEVELS WILL BE OUT OF THE NORTH-NORTHWEST...WHICH WILL FAVOR
LAKE EFFECT SNOW SHOWERS ACROSS THE SOUTH SHORE. AT THIS TIME IT IS
DIFFICULT TO GET TOO SPECIFIC WITH AMOUNTS...BUT OVERALL EXPECT A
LONG-DURATION LIGHT TO MODERATE SNOW EVENT...WITH THE MOST INTENSE
SNOWFALL LATE SATURDAY NIGHT INTO SUNDAY WHEN THE MID-LEVEL MOISTURE
AND WEAK LARGE-SCALE FORCING FROM THE UPPER LOW ENHANCES THE LAKE
EFFECT PROCESSES.
CLOUDY THROUGH THE WEEKEND WITH SOME CLEARING POSSIBLE EARLY NEXT
WORK WEEK AS HIGH PRESSURE BUILDS ACROSS THE GREAT PLAINS AND
MID/UPPER MISSISSIPPI VALLEY. GUIDANCE THEN BEGINS TO DIVERGE WITH
ECMWF A BIT FASTER AND FLATTER IN THE UPPER FLOW WHILE THE GFS
PERSIST WITH A RIDGE ACROSS THE WEST. DESPITE THE MODEL DIFFERENCES
THE TREND LOOKS TO BE TOWARDS SEASONABLE TEMPS WITH THE NEXT CHANCE
OF SNOW ARRIVING ARRIVING MID-WEEK WITH A CLIPPER-LIKE SYSTEM.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1202 AM CST WED JAN 13 2016
MVFR/IFR CIGS ARE COVERING MUCH OF THE NORTHLAND. THERE IS A TIGHT
GRADIENT WHERE VFR CIGS ARE PRESENT PER THE LATEST OBS ACROSS FAR
NORTHERN AND NORTHEAST MINNESOTA. THE LATEST OBS SHOW MVFR CIGS
SPREADING FURTHER TO THE EAST...SO EXPECTING KINL TO BECOME MVFR.
SNOW WILL MOVE INTO THE AREA LATE TONIGHT...IMPACTING KBRD BEFORE
SPREADING EASTWARDS AND NORTH AS THE DAY PROGRESSES. EXPECTING
SITES REMAIN IN MVFR/IFR CONDITIONS TO OCCUR. LIFR CONDITIONS WILL
OCCUR IN THE HEAVIEST SNOW BANDS...AND TRIED TO HINT AT THIS
POSSIBILITY AT KDLH AS THE LATEST NAM/RAP/GFS/GFSLAMP HINT AT THIS
AS WELL. ANOTHER COMPLICATION IS THE LATEST GUIDANCE DEPICTS
KBRD/KHYR STAYING ON THE FRINGE OF THE SNOWFALL AXIS. SO TRIED TO
SHOW IMPROVEMENT TO MVFR CONDITIONS AROUND 18Z...HOWEVER IF THIS
AXIS SHIFTS FURTHER SOUTH THEN IFR CONDITIONS ARE MORE LIKELY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 6 20 14 16 / 40 100 80 20
INL -19 13 -1 5 / 10 50 40 10
BRD 9 24 10 13 / 70 80 60 10
HYR 4 23 19 23 / 50 70 60 60
ASX 3 22 18 24 / 30 80 80 60
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
LS...NONE.
&&
$$
UPDATE...MELDE
SHORT TERM...DAP
LONG TERM...JJM
AVIATION...WL
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
850 PM CST FRI JAN 15 2016
.UPDATE:
Issued at 842 PM CST Fri Jan 15 2016
Forecast looks pretty much on track. Made some minor tweaks to
clean up cloud trends over central Missouri. Low clouds are
breaking up over Columbia and Jefferson City, but higher clouds
are streaming in from the west...so forecast should still say
partly to mostly cloudy. Not sure how far east the clearing will
get tonight or tomorrow morning. There`s an expansive area of
stratus upstream which stretches up through eastern Iowa into
Wisconsin. Low level RH forecast on the RAP supports little if
any clearing along and east of the Mississippi for the rest of the
night. Since the western edge of the stratus isn`t moving much
over northeast Missouri, I tend to agree.
Carney
&&
.SHORT TERM: (Tonight and Saturday)
Issued at 310 PM CST Fri Jan 15 2016
Cold but tranquil weather will persist over the next 30 hours. The
cold front has passed through the region and into the OH Valley
and CAA is underway. Stratus, northwest winds, and CAA will continue
tonight as high pressure continues to build south/southeastward
from the northern Plains into the MS Valley. Seeing a few flurries
this afternoon and these may persist into early this evening. Weak
high pressure will dominate on Saturday with gradually diminishing
clouds.
Glass
.LONG TERM: (Saturday Night through Next Friday)
Issued at 310 PM CST Fri Jan 15 2016
Little change in the overall scenario for Saturday Night into
Sunday. A deep vortex/trof will dig southeastward out of south
central Canada into the Great Lakes region carving out a longwave
trof which will dominate the eastern 2/3rds of the CONUS Sunday
into Monday. This digging system will send a secondary cold front
into the region late Saturday night into Sunday morning, that will
usher in the coldest air mass we have seen thus far this winter.
Large scale forcing with the upper system and low level
frontogenetic forcing will combine to produce a band of snow
across the northern Plains on Saturday afternoon and this band
will drop south into IA during the evening and northern MO and
northern IL overnight into early Sunday morning. Present
indications are the band of accumulating snow will weaken
significantly on Sunday morning and largely dissipate to flurries
by afternoon as large scale support quickly shifts northeast of
the area. We`re thinking of potential for light accumulations with
up to an inch of dry snow across parts of far northern MO into
west central IL tapering southward to a dusting in the vicinity of
I-70. Otherwise Sunday will feature blustry conditions with gusty
northwest winds and strong CAA. A large surface high will dominate
the area Sunday Night into Monday Night marked by well below
average temperatures.
By Tuesday the overall flow aloft flattens some as the eastern
U.S. upper vortex/trof depart into the Atlantic. This less
amplified and faster flow from Tues-Fri has lead to rather large
model differences the last few days. With today`s 12z model runs
however we are seeing better agreement although there remain some
timing and amplitude differences with waves in the flow. We are
still looking at another snow event somewhere in the Tuesday-
early Wednesday morning time frame associated with low level WAA
on the backside of the retreating high, frontogenesis, and with a
west-northwest flow short wave. The GFS remains faster and
stronger with greater snow amounts. The late week system Wednesday
night into Thursday night is virtually non-existant now with the
GFS and ECMWF forecasting northwest flow and limited moisture.
Only the GEM still has any suggestions, and thus forecast POPS
have decreased.
Glass
&&
.AVIATION: (For the 00z TAFs through 00z Saturday Evening)
Issued at 453 PM CST Fri Jan 15 2016
Surface high pressure ridge over the northern Plains will build
southeastward into our area tonight and Saturday. Nwly surface
winds will continue through the period, although the wind speed
will gradually weaken as the surface pressure gradient relaxes.
The MVFR cigs will continue for most of the night along with
light haze. The conditions should improve to VFR in COU by 12Z
Saturday as the stratus deck shifts east, then by 15Z in UIN, and
by late morning in the St Lous metro area.
Specifics for KSTL: The MVFR cigs along with light haze will
continue tonight, improving to VFR conditions by late Saturday
morning. The nwly surface wind will gradually weaken tonight and
Saturday.
GKS
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1210 PM CST THU JAN 14 2016
.UPDATE:
Issued at 1046 AM CST Thu Jan 14 2016
Observations from cooperative observers this morning indicate that
snow depth over the remaining snow field is an inch or less so it
will take very little heating to melt the rest of it off today.
Winds are southwesterly at the surface which are conducive to a
warm up today and ILX & SGF`s 850mb temps are in the 4-7C range.
Have raised temperatures in the northern and eastern counties
based on current trends. Have also pushed back on the onset of
showers this evening as I do not think showers will start until
later this evening based on latest satellite trends as well as runs
of the RAP and CAMS.
Britt
&&
.SHORT TERM: (Through Late This Afternoon)
Issued at 243 AM CST Thu Jan 14 2016
The amplified flow aloft that has prevailed across much of North
America the past few days has become flatter across the CONUS, but
with NW flow continuing for our region for the time being. At the
surface, SW flow prevails, and this has kept temps a bit milder than
in previous nights, with readings in the 30s. Skies were mostly
clear with just a bit of thin cirrus clouds rolling thru.
A weak RIDGE aloft will slide thru today, ending the NW flow, in
response to a decently strong shortwave that will enter the Plains
by late this afternoon. The S-SW flow at the surface will continue
as an area of LOW pressure approaches our area from the northwest--
reaching the MN/IA border late today. No areas of lift with a dry
atmospheric column should result in no pcpn today. Actually, most
areas should see clear skies or sunshine thru a thin veil of clouds
at worst.
Regarding temps, the dropping pressure at the surface and passage of
a RIDGE aloft will result in much higher thicknesses (and temps)
than 24hrs ago, to something along the lines of what was seen in
western KS, where max temps ranged from the mid 50s to around 60.
For much of our region, this is exactly what is being forecast which
is at or slightly above the higher MAV MOS numbers. Only in the old
snowpack zone to the N and W of STL metro were the temps trimmed a
few degrees but shouldn`t impact things too much with this already
greatly reduced from what it was.
TES
.LONG TERM: (Tonight through Wednesday)
Issued at 243 AM CST Thu Jan 14 2016
Not much change leading into the weekend with mdls still in good
agreement with a brief RA event tngt into Fri. Prev forecast is
still on track with showers moving newd into the region late tonight
and thru Fri morning. Chances will decrease quickly on Fri as the
cdfnt and upper trof move ewd out of the CWA by 18z. With strong CAA
behind the fnt, temps will fall during the day and continue Fri
night.
Height falls continue thru the weekend with a deep trof digging into
the area late Sat into Sun bringing a secondary cdfnt to the area.
Mdls have come into better agreement with this system, tho the GFS
remains 6 to 12 hours behind the consensus. Have raised PoPs for
this system and added PoPs on Sun morning. PoPs on Sun may need to
be raised, but with the system moving so fast, precip may be E of
the CWA by 12z Sun. SN amounts appear to be minimal attm, remaining
at a half inch or so.
Behind this system a strong sfc ridge builds into the region with
the coldest temps of the season so far accompanying it. NW flow sets
up over the region with height rises for Tues and beyond. With the
NW flow, chances for precip increase slightly. However, with
differences among mdl solns, have kept only slight chances going for
now.
Tilly
&&
.AVIATION: (For the 18z TAFs through 18z Friday Afternoon)
Issued at 1208 AM CST Thu Jan 14 2016
Still expect dry and VFR conditions with some gusty winds this
afternoon at all of the terminals. LLWS will develop by this
evening as a southerly 50kt low level jet develops over the area,
but then it should diminish by later this tonight as it veers off
to the east. Rain showers will develop over the area later this
evening and overnight which may cause some wet runways. Low MVFR
and possible IFR ceilings are also expected ahead of the cold
front that will move through the area. Winds will veer from south
to west behind this cold front.
Specifics for KSTL: Dry and VFR conditions are expected through
06Z before showers and MVFR conditions move into the area from
the southwest ahead a cold front that will move through the
terminal around around 14Z. LLWS still looks likely tonight and
should end with frontal passage in the morning.
Britt
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1048 AM CST THU JAN 14 2016
.UPDATE:
Issued at 1046 AM CST Thu Jan 14 2016
Observations from cooperative observers this morning indicate that
snow depth over the remaining snow field is an inch or less so it
will take very little heating to melt the rest of it off today.
Winds are southwesterly at the surface which are conducive to a
warm up today and ILX & SGF`s 850mb temps are in the 4-7C range.
Have raised temperatures in the northern and eastern counties
based on current trends. Have also pushed back on the onset of
showers this evening as I do not think showers will start until
later this evening based on latest satellite trends as well as runs
of the RAP and CAMS.
Britt
&&
.SHORT TERM: (Through Late This Afternoon)
Issued at 243 AM CST Thu Jan 14 2016
The amplified flow aloft that has prevailed across much of North
America the past few days has become flatter across the CONUS, but
with NW flow continuing for our region for the time being. At the
surface, SW flow prevails, and this has kept temps a bit milder than
in previous nights, with readings in the 30s. Skies were mostly
clear with just a bit of thin cirrus clouds rolling thru.
A weak RIDGE aloft will slide thru today, ending the NW flow, in
response to a decently strong shortwave that will enter the Plains
by late this afternoon. The S-SW flow at the surface will continue
as an area of LOW pressure approaches our area from the northwest--
reaching the MN/IA border late today. No areas of lift with a dry
atmospheric column should result in no pcpn today. Actually, most
areas should see clear skies or sunshine thru a thin veil of clouds
at worst.
Regarding temps, the dropping pressure at the surface and passage of
a RIDGE aloft will result in much higher thicknesses (and temps)
than 24hrs ago, to something along the lines of what was seen in
western KS, where max temps ranged from the mid 50s to around 60.
For much of our region, this is exactly what is being forecast which
is at or slightly above the higher MAV MOS numbers. Only in the old
snowpack zone to the N and W of STL metro were the temps trimmed a
few degrees but shouldn`t impact things too much with this already
greatly reduced from what it was.
TES
.LONG TERM: (Tonight through Wednesday)
Issued at 243 AM CST Thu Jan 14 2016
Not much change leading into the weekend with mdls still in good
agreement with a brief RA event tngt into Fri. Prev forecast is
still on track with showers moving newd into the region late tonight
and thru Fri morning. Chances will decrease quickly on Fri as the
cdfnt and upper trof move ewd out of the CWA by 18z. With strong CAA
behind the fnt, temps will fall during the day and continue Fri
night.
Height falls continue thru the weekend with a deep trof digging into
the area late Sat into Sun bringing a secondary cdfnt to the area.
Mdls have come into better agreement with this system, tho the GFS
remains 6 to 12 hours behind the consensus. Have raised PoPs for
this system and added PoPs on Sun morning. PoPs on Sun may need to
be raised, but with the system moving so fast, precip may be E of
the CWA by 12z Sun. SN amounts appear to be minimal attm, remaining
at a half inch or so.
Behind this system a strong sfc ridge builds into the region with
the coldest temps of the season so far accompanying it. NW flow sets
up over the region with height rises for Tues and beyond. With the
NW flow, chances for precip increase slightly. However, with
differences among mdl solns, have kept only slight chances going for
now.
Tilly
&&
.AVIATION: (For the 12z TAFs through 12z Friday Morning)
Issued at 555 AM CST Thu Jan 14 2016
VFR conditions will prevail at the TAF sites thru early this
evening. Indications are increasing that stratus will overspread
the area later this evening and continue overnight and into
Friday. Have lowered CIGs but kept in the lower MVFR category for
the time being. There are indications that this may be IFR
category but enough uncertainty and doubt to leave out at this
time. Intermittent light rain will also overspread the area in
this same time range and have handled in the TAFs with either VCSH
or prevailing -RA. Cold FROPA and accompanying sharp wind shift
from the W-NW will occur late tonight for UIN and COU and during
Friday morning for STL metro sites--otherwise persistent S-SW wind
to continue. This should end rain chances as well, at least
enough to drop from TAF. Two rounds of LLWS: first ongoing and
more marginal but includes significant directional shear to fade
late this morning, and the second with a more significant low
level jet this evening but should be brief.
Specifics for KSTL: VFR until late this evening with deteriorating
conditions overnight with CIGs to low-end MVFR, possibly IFR, and
intermittent light rain. S-SW winds becoming gusty today, sharply
shifting from W-NW during Friday morning with cold FROPA. LLWS
this morning and again this evening.
TES
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1259 PM CST THU JAN 14 2016
.UPDATE...
ISSUED AT 1259 PM CST THU JAN 14 2016
THE WARM LAYER ALOFT QUICKLY ERODED FROM NORTHWEST TO SOUTHEAST IN
THE LATE MORNING ON LOW- AND MID-LEVEL COLD AIR ADVECTION...SO THE
PRECIPITATION HAS ALMOST ALL CHANGED TO SNOW AS OF 1845 UTC. WE
THUS LET THE FREEZING RAIN ADVISORY EXPIRE AT NOON CST. ALL IN ALL
THE FORECAST IS LARGELY ON TRACK AND ALL WE DID WITH THIS UPDATE
WAS ADJUST HOURLY POPS TO FURTHER REFINE THE BACK EDGE OF SNOW AS
IT BEGINS TO END FROM NORTHWEST TO SOUTHEAST THIS AFTERNOON. THE
WINTER WEATHER ADVISORY FOR WELLS...FOSTER...AND STUTSMAN COUNTIES
IS ON TRACK AND NO CHANGE IS NEEDED TO IT AT THIS TIME.
UPDATE ISSUED AT 1010 AM CST THU JAN 14 2016
WE HAVE ADDED A WINTER WEATHER ADVISORY FOR 3-5 INCHES OF SNOW IN
WELLS...FOSTER...AND STUTSMAN COUNTIES THROUGH 01 UTC /7 PM CST/.
RADAR TRENDS...THE 12 UTC NAM AND A SLOW SHIFT SOUTHWARD IN HRRR/
RAP GUIDANCE WITH THE MAIN FRONTOGENETICAL FORCING AND MODEL QPF
SUPPORTED ADDING THOSE COUNTIES TO AN ADVISORY. MEANWHILE...COLD
AIR ADVECTION CONTINUES TO INCREASE FROM NORTH TO SOUTH AND THAT
WILL DRIVE A CHANGE TO LIGHT SNOW OVER SOUTHWEST AND SOUTH CENTRAL
ND BY MIDDAY...BUT NOT UNTIL AFTER ADDITIONAL FREEZING RAIN OCCURS
IN SOME AREAS...LIKE BISMARCK/MANDAN BASED ON RADAR TRENDS AT 16
UTC. WE WILL LIKELY TRIM ADDITIONAL COUNTIES FROM THE FREEZING
RAIN ADVISORY IN SOUTHWEST ND IN THE NEXT HOUR OR SO AS THE
TRANSITION TO SNOW OCCURS.
AS FOR THE GRIDDED FORECAST...WE ADJUSTED HOURLY POPS WITH THIS
UPDATE USING A TIME-LAGGED CONSENSUS OF SHORT RANGE/RAPID REFRESH
GUIDANCE...WHICH MAINLY MEANT A BIT FASTER END TO PRECIPITATION
FROM NORTH TO SOUTH THIS AFTERNOON AND EVENING. THAT IS SUPPORTED
BY OBSERVATIONS OVER NORTHWESTERN ND...WHERE EVEN SNOW HAS ENDED
IN WILLISTON AS OF MID MORNING.
UPDATE ISSUED AT 854 AM CST THU JAN 14 2016
QUICK UPDATE TO CANCEL THE FREEZING RAIN ADVISORY FOR WILLIAMS AND
MCKENZIE COUNTIES...WHERE PRECIPITATION HAS TRANSITIONED TO SNOW
WITH THE ONSET OF LOW- AND MID-LEVEL COLD AIR ADVECTION. THE
ADVISORY REMAINS IN PLACE OVER THE REST OF SOUTHWEST AND PARTS OF
SOUTH CENTRAL ND.
WE ARE CLOSELY ASSESSING SNOWFALL POTENTIAL FROM WELLS AND PIERCE
TO FOSTER COUNTIES...WHICH MAY REQUIRE A WINTER WEATHER ADVISORY.
RADAR REFLECTIVITIES HAVE INCREASED UPSTREAM OF THOSE AREAS...AND
MAY IMPLY HEAVIER SNOW RATES WILL DEVELOP DOWNSTREAM IN THE NEXT
FEW HOURS.
UPDATE ISSUED AT 633 AM CST THU JAN 14 2016
WITH A RECENT UPDATE TO ISSUE THE FREEZING RAIN ADVISORY...NO
SIGNIFICANT CHANGES DURING THE PAST HOUR. DID BUMP UP POPS IN THE
FAR SOUTHWEST WITH HIGHER REFLECTIVITIES MOVING INTO BOWMAN AND
SLOPE COUNTIES. WILL NEED TO MONITOR FOR POTENTIAL HEAVIER THAN 3
INCH SNOW AMOUNTS OVER PORTIONS OF THE NORTH CENTRAL INTO THE
NORTHERN JAMES RIVER VALLEY TODAY. UPDATED TEXT PRODUCTS WILL BE
OUT SHORTLY.
UPDATE ISSUED AT 534 AM CST THU JAN 14 2016
UPDATE TO ISSUE A FREEZING RAIN ADVISORY FOR MOST OF WESTERN AND
SOUTH CENTRAL NORTH DAKOTA. RWIS/ROAD TEMPERATURES AT OR BELOW
FREEZING...AND LIGHT FREEZING RAIN BEING REPORTED AT WILLISTON.
WITH MORE PRECIPITATION COMING IN FROM EASTERN MONTANA THIS
MORNING AND THE HRRR PRECIPITATION FORECAST SHOWING IT PUSHING
INTO SOUTH CENTRAL NORTH DAKOTA...WE HAVE DECIDED TO ISSUE A
FREEZING RAIN ADVISORY UNTIL NOON CST. UPDATES TO FORECAST
PRODUCTS BEING SENT AS WE SPEAK.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 128 AM CST THU JAN 14 2016
HIGHLIGHTS IN THE SHORT TERM CENTER AROUND LIGHT FREEZING RAIN
CHANCES SOUTHWEST THROUGH SOUTH CENTRAL UNTIL MID MORNING...AND
SNOW ACCUMULATIONS ACROSS ALL OF WESTERN AND CENTRAL NORTH DAKOTA
THROUGH THIS EVENING...WITH THE HIGHEST AMOUNTS FAVORED IN THE
NORTHERN JAMES RIVER VALLEY.
AFTER COLLABORATING WITH WFO GRAND FORKS...THE DECISION WAS TO
CONTINUE WITH THE SPECIAL WEATHER STATEMENT THIS MORNING FOR BOTH
OFFICES.
THE LATEST SURFACE ANALYSIS CONTINUES TO ADVERTISE A DISTINCT
TEMPERATURE GRADIENT ASSOCIATED WITH A STATIONARY FRONTAL SYSTEM
FROM NEAR SWIFT CURRENT SASKATCHEWAN TO WILLISTON AND GLEN
ULLIN...INTO SELFRIDGE AND ABERDEEN SOUTH DAKOTA. ON THE WARM
SIDE OF THIS BOUNDARY...WEST AND SOUTH OF THE FRONT...TEMPERATURES
ARE IN THE LOW TO MID 30S. EAST AND NORTH OF THE FRONT...TEENS TO
SINGLE DIGITS. WATER VAPOR IMAGERY LOOP SHOWS A PLUME OF MOISTURE
OVERSPREADING WESTERN AND CENTRAL NORTH DAKOTA AS MULTIPLE SHORTWAVES
IN CENTRAL/EASTERN MONTANA ARE PROVIDING THE NECESSARY LARGE SCALE
ASCENT. THROUGH MID MORNING/9AM CST...BUFKIT SOUNDINGS CONTINUE TO
ADVERTISE THAT IF PRECIPITATION IS ABLE TO MAKE IT TO THE
GROUND...THEN MOST LOCATIONS IN SOUTHWEST AND SOUTH CENTRAL NORTH
DAKOTA (THOSE ALONG AND SOUTH OF THE AFOREMENTIONED
BOUNDARY)...WOULD BE FAVORED FOR LIGHT FREEZING RAIN. WILL
CONTINUE TO WATCH OBSERVATIONS UPSTREAM IN EASTERN MONTANA AND
MONITOR AS PRECIPITATION MOVES ACROSS THE BORDER. MAY NEED TO MAKE
QUICK CHANGES EARLY THIS MORNING IF THE SITUATION WARRANTS.
OTHERWISE...SURFACE LOW PRESSURE IN SOUTHERN SASKATCHEWAN WILL
MOVE ALONG THIS BOUNDARY TODAY. WIDESPREAD PRECIPITATION WILL
RESULT WITH CATEGORICAL POPS FOR CENTRAL AND NORTHERN NORTH
DAKOTA. WHEN ASSESSING ANY HEAVY BANDED SNOW POTENTIAL...LOW TO
MID LEVEL FRONTOGENETICAL FORCING AND DEEP LAYER OMEGA ALIGN
TOGETHER BETWEEN 18Z AND 21Z OVER THE NORTHERN JAMES RIVER VALLEY
AND AREAS EAST. THIS IS WHERE WE ARE EXPECTING THE HIGHEST AMOUNTS
OF 3 TO 4 INCHES...WHICH WOULD INCLUDE FOSTER AND WELLS COUNTIES.
THIS IS SHY OF ADVISORY CRITERIA...HOWEVER NOT BY MUCH AND WILL
CLOSELY MONITOR THE HIGHER RESOLUTION MODELS TO SEE IF CHANGES
TAKE PLACE ON THE PLACEMENT AND STRENGTH CURRENTLY SEEN. THE
NAM/GFS/SREF BUFKIT SOUNDINGS AT CARRINGTON SHOW A PEAK OMEGA IN
THE DENDRITIC GROWTH ZONES (-12C TO -18C) AROUND NOON CST...THEN
WANING THEREAFTER. THE OMEGA IS NOT OFF THE CHART...BUT SUGGESTS
ASCENT WILL BE STRONG ENOUGH FOR A PERIOD OF MODERATE SNOW LATE
THIS MORNING INTO THE EARLY AFTERNOON. HENCE THIS IS WHY FOSTER/WELLS
COUNTIES ARE FAVORED FOR THE HIGHEST AMOUNTS. SOUNDINGS SHOW A
RAPID DIMINISH OF THE OMEGA MAX WITHIN THE DENDRITIC GROWTH ZONE
WHEN YOU GET TO JAMESTOWN. SO...TOTAL SNOWFALL ACCUMULATIONS OUTSIDE
OF THE NORTHERN JAMES RIVER VALLEY...EXPECTING 1 TO 3 INCHES NORTH
OF INTERSTATE 94...WITH 1 INCH AMOUNTS FAVORING LOCATIONS ALONG
AND SOUTH OF INTERSTATE 94 THROUGH THIS EVENING. THE SNOW EXITS
THE FAR SOUTHERN JAMES RIVER VALLEY AROUND 03Z-06Z FRIDAY.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 128 AM CST THU JAN 14 2016
THE MAIN FORECAST HIGHLIGHT IN THE LONG TERM PERIOD WILL BE WIND
CHILL HIGHLIGHTS FRIDAY NIGHT RIGHT THROUGH THE WEEKEND AND INTO
EARLY NEXT WEEK.
WE BEGIN THE LONG TERM PERIOD ON FRIDAY MORNING WITH ARCTIC AIR
BUILDING OVER THE NORTHERN PLAINS. EXPECT MAINLY CLOUDY SKIES WITH
LOW LEVEL MOISTURE IN PLACE AND A CYCLONIC FLOW ALOFT. A WEAK
SURFACE TROUGH AND BAROCLINIC ZONE REMAINS OVER THE FAR SOUTHWEST
AND THIS WILL BE THE MOST FAVORED LOCATION FOR LIGHT SNOW THROUGH
SATURDAY. ALTHOUGH LIGHT SNOW/FLURRIES CAN NOT BE RULED OUT ACROSS
THE FORECAST AREA FRIDAY AND HAVE A SLIGHT CHANCE OVER A GOOD
PORTION OF THE WEST FRIDAY MORNING. THEN FRIDAY AFTERNOON THROUGH
SATURDAY WE HAVE LIMITED SNOW CHANCES TO MAINLY SOUTHWEST NORTH
DAKOTA. ALTHOUGH SNOW AMOUNTS WILL BE LIGHT...WITH RATIO`S
APPROACHING 20-1 FRIDAY AFTERNOON THROUGH SATURDAY...WE COULD SEE AN
INCH OR TWO ACCUMULATION OVER PORTIONS OF THE SOUTHWEST THROUGH THE
TWO DAY PERIOD.
OTHERWISE...THE MAIN STORY WILL BE WIND CHILLS. EXPECT WIND CHILL
HIGHLIGHTS FRIDAY NIGHT AND THROUGH THE DAY SATURDAY...MAINLY NORTH
AND EAST OF LAKE SAKAKAWEA AND THE MISSOURI RIVER. THEN ACROSS THE
ENTIRE FORECAST AREA SATURDAY NIGHT INTO SUNDAY MORNING. AREAS NORTH
AND EAST OF THE LAKE AND MISSOURI RIVER COULD SEE WIND CHILL WARNING
CRITERIA WIND CHILLS OF 4O TO 45 BELOW ZERO SATURDAY NIGHT INTO
SUNDAY MORNING. THEN SOME MODERATION SUNDAY NIGHT INTO MONDAY
MORNING...BUT WIND CHILL HIGHLIGHT WILL STILL BE NEEDED NORTH AND
EAST. FINALLY MONDAY NIGHT INTO TUESDAY MORNING...PERHAPS ONLY
AREAS FROM THE TURTLE MOUNTAINS INTO THE JAMES RIVER VALLEY MAY
NEED HIGHLIGHTS. AT THIS TIME WE HAVE A MENTION OF THE WIND
CHILLS IN OUR CURRENT SPS WHICH ALSO COVERS THE SHORT TERM
SNOWFALL...AS WELL AS THE HWO.
AFTER DAYTIME HIGHS OF 10 BELOW NORTHEAST TO 10 ABOVE SOUTHWEST
SATURDAY AND SUNDAY...WE BEGIN TO MODERATE NEXT WEEK...ESPECIALLY IN
THE SOUTHWEST WITH HIGHS CLIMBING INTO THE TEENS AND LOWER 20S.
THE SLOW MODERATION IN TEMPERATURES CONTINUES INTO MID WEEK WITH
MINIMAL PRECIPITATION CHANCES IN A NORTHWEST FLOW PATTERN.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1259 PM CST THU JAN 14 2016
IFR AND LIFR CONDITIONS IN SOUTHWEST AND CENTRAL ND WILL SLOWLY
IMPROVE IN THE LATE AFTERNOON AS SNOW ENDS FROM NORTH TO SOUTH.
HOWEVER...MVFR CEILINGS AND POSSIBLY SOME SNOW SHOWERS WILL
LIKELY PREVAIL OVER WESTERN AND PARTS OF CENTRAL ND TONIGHT INTO
FRIDAY MORNING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 PM CST THIS EVENING FOR NDZ023-
025-037.
&&
$$
UPDATE...CJS
SHORT TERM...KS
LONG TERM...TWH
AVIATION...NH/CJS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1010 AM CST THU JAN 14 2016
.UPDATE...
ISSUED AT 1010 AM CST THU JAN 14 2016
WE HAVE ADDED A WINTER WEATHER ADVISORY FOR 3-5 INCHES OF SNOW IN
WELLS...FOSTER...AND STUTSMAN COUNTIES THROUGH 01 UTC /7 PM CST/.
RADAR TRENDS...THE 12 UTC NAM AND A SLOW SHIFT SOUTHWARD IN HRRR/
RAP GUIDANCE WITH THE MAIN FRONTOGENETICAL FORCING AND MODEL QPF
SUPPORTED ADDING THOSE COUNTIES TO AN ADVISORY. MEANWHILE...COLD
AIR ADVECTION CONTINUES TO INCREASE FROM NORTH TO SOUTH AND THAT
WILL DRIVE A CHANGE TO LIGHT SNOW OVER SOUTHWEST AND SOUTH CENTRAL
ND BY MIDDAY...BUT NOT UNTIL AFTER ADDITIONAL FREEZING RAIN OCCURS
IN SOME AREAS...LIKE BISMARCK/MANDAN BASED ON RADAR TRENDS AT 16
UTC. WE WILL LIKELY TRIM ADDITIONAL COUNTIES FROM THE FREEZING
RAIN ADVISORY IN SOUTHWEST ND IN THE NEXT HOUR OR SO AS THE
TRANSITION TO SNOW OCCURS.
AS FOR THE GRIDDED FORECAST...WE ADJUSTED HOURLY POPS WITH THIS
UPDATE USING A TIME-LAGGED CONSENSUS OF SHORT RANGE/RAPID REFRESH
GUIDANCE...WHICH MAINLY MEANT A BIT FASTER END TO PRECIPITATION
FROM NORTH TO SOUTH THIS AFTERNOON AND EVENING. THAT IS SUPPORTED
BY OBSERVATIONS OVER NORTHWESTERN ND...WHERE EVEN SNOW HAS ENDED
IN WILLISTON AS OF MID MORNING.
UPDATE ISSUED AT 854 AM CST THU JAN 14 2016
QUICK UPDATE TO CANCEL THE FREEZING RAIN ADVISORY FOR WILLIAMS AND
MCKENZIE COUNTIES...WHERE PRECIPITATION HAS TRANSITIONED TO SNOW
WITH THE ONSET OF LOW- AND MID-LEVEL COLD AIR ADVECTION. THE
ADVISORY REMAINS IN PLACE OVER THE REST OF SOUTHWEST AND PARTS OF
SOUTH CENTRAL ND.
WE ARE CLOSELY ASSESSING SNOWFALL POTENTIAL FROM WELLS AND PIERCE
TO FOSTER COUNTIES...WHICH MAY REQUIRE A WINTER WEATHER ADVISORY.
RADAR REFLECTIVITIES HAVE INCREASED UPSTREAM OF THOSE AREAS...AND
MAY IMPLY HEAVIER SNOW RATES WILL DEVELOP DOWNSTREAM IN THE NEXT
FEW HOURS.
UPDATE ISSUED AT 633 AM CST THU JAN 14 2016
WITH A RECENT UPDATE TO ISSUE THE FREEZING RAIN ADVISORY...NO
SIGNIFICANT CHANGES DURING THE PAST HOUR. DID BUMP UP POPS IN THE
FAR SOUTHWEST WITH HIGHER REFLECTIVITIES MOVING INTO BOWMAN AND
SLOPE COUNTIES. WILL NEED TO MONITOR FOR POTENTIAL HEAVIER THAN 3
INCH SNOW AMOUNTS OVER PORTIONS OF THE NORTH CENTRAL INTO THE
NORTHERN JAMES RIVER VALLEY TODAY. UPDATED TEXT PRODUCTS WILL BE
OUT SHORTLY.
UPDATE ISSUED AT 534 AM CST THU JAN 14 2016
UPDATE TO ISSUE A FREEZING RAIN ADVISORY FOR MOST OF WESTERN AND
SOUTH CENTRAL NORTH DAKOTA. RWIS/ROAD TEMPERATURES AT OR BELOW
FREEZING...AND LIGHT FREEZING RAIN BEING REPORTED AT WILLISTON.
WITH MORE PRECIPITATION COMING IN FROM EASTERN MONTANA THIS
MORNING AND THE HRRR PRECIPITATION FORECAST SHOWING IT PUSHING
INTO SOUTH CENTRAL NORTH DAKOTA...WE HAVE DECIDED TO ISSUE A
FREEZING RAIN ADVISORY UNTIL NOON CST. UPDATES TO FORECAST
PRODUCTS BEING SENT AS WE SPEAK.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 128 AM CST THU JAN 14 2016
HIGHLIGHTS IN THE SHORT TERM CENTER AROUND LIGHT FREEZING RAIN
CHANCES SOUTHWEST THROUGH SOUTH CENTRAL UNTIL MID MORNING...AND
SNOW ACCUMULATIONS ACROSS ALL OF WESTERN AND CENTRAL NORTH DAKOTA
THROUGH THIS EVENING...WITH THE HIGHEST AMOUNTS FAVORED IN THE
NORTHERN JAMES RIVER VALLEY.
AFTER COLLABORATING WITH WFO GRAND FORKS...THE DECISION WAS TO
CONTINUE WITH THE SPECIAL WEATHER STATEMENT THIS MORNING FOR BOTH
OFFICES.
THE LATEST SURFACE ANALYSIS CONTINUES TO ADVERTISE A DISTINCT
TEMPERATURE GRADIENT ASSOCIATED WITH A STATIONARY FRONTAL SYSTEM
FROM NEAR SWIFT CURRENT SASKATCHEWAN TO WILLISTON AND GLEN
ULLIN...INTO SELFRIDGE AND ABERDEEN SOUTH DAKOTA. ON THE WARM
SIDE OF THIS BOUNDARY...WEST AND SOUTH OF THE FRONT...TEMPERATURES
ARE IN THE LOW TO MID 30S. EAST AND NORTH OF THE FRONT...TEENS TO
SINGLE DIGITS. WATER VAPOR IMAGERY LOOP SHOWS A PLUME OF MOISTURE
OVERSPREADING WESTERN AND CENTRAL NORTH DAKOTA AS MULTIPLE SHORTWAVES
IN CENTRAL/EASTERN MONTANA ARE PROVIDING THE NECESSARY LARGE SCALE
ASCENT. THROUGH MID MORNING/9AM CST...BUFKIT SOUNDINGS CONTINUE TO
ADVERTISE THAT IF PRECIPITATION IS ABLE TO MAKE IT TO THE
GROUND...THEN MOST LOCATIONS IN SOUTHWEST AND SOUTH CENTRAL NORTH
DAKOTA (THOSE ALONG AND SOUTH OF THE AFOREMENTIONED
BOUNDARY)...WOULD BE FAVORED FOR LIGHT FREEZING RAIN. WILL
CONTINUE TO WATCH OBSERVATIONS UPSTREAM IN EASTERN MONTANA AND
MONITOR AS PRECIPITATION MOVES ACROSS THE BORDER. MAY NEED TO MAKE
QUICK CHANGES EARLY THIS MORNING IF THE SITUATION WARRANTS.
OTHERWISE...SURFACE LOW PRESSURE IN SOUTHERN SASKATCHEWAN WILL
MOVE ALONG THIS BOUNDARY TODAY. WIDESPREAD PRECIPITATION WILL
RESULT WITH CATEGORICAL POPS FOR CENTRAL AND NORTHERN NORTH
DAKOTA. WHEN ASSESSING ANY HEAVY BANDED SNOW POTENTIAL...LOW TO
MID LEVEL FRONTOGENETICAL FORCING AND DEEP LAYER OMEGA ALIGN
TOGETHER BETWEEN 18Z AND 21Z OVER THE NORTHERN JAMES RIVER VALLEY
AND AREAS EAST. THIS IS WHERE WE ARE EXPECTING THE HIGHEST AMOUNTS
OF 3 TO 4 INCHES...WHICH WOULD INCLUDE FOSTER AND WELLS COUNTIES.
THIS IS SHY OF ADVISORY CRITERIA...HOWEVER NOT BY MUCH AND WILL
CLOSELY MONITOR THE HIGHER RESOLUTION MODELS TO SEE IF CHANGES
TAKE PLACE ON THE PLACEMENT AND STRENGTH CURRENTLY SEEN. THE
NAM/GFS/SREF BUFKIT SOUNDINGS AT CARRINGTON SHOW A PEAK OMEGA IN
THE DENDRITIC GROWTH ZONES (-12C TO -18C) AROUND NOON CST...THEN
WANING THEREAFTER. THE OMEGA IS NOT OFF THE CHART...BUT SUGGESTS
ASCENT WILL BE STRONG ENOUGH FOR A PERIOD OF MODERATE SNOW LATE
THIS MORNING INTO THE EARLY AFTERNOON. HENCE THIS IS WHY FOSTER/WELLS
COUNTIES ARE FAVORED FOR THE HIGHEST AMOUNTS. SOUNDINGS SHOW A
RAPID DIMINISH OF THE OMEGA MAX WITHIN THE DENDRITIC GROWTH ZONE
WHEN YOU GET TO JAMESTOWN. SO...TOTAL SNOWFALL ACCUMULATIONS OUTSIDE
OF THE NORTHERN JAMES RIVER VALLEY...EXPECTING 1 TO 3 INCHES NORTH
OF INTERSTATE 94...WITH 1 INCH AMOUNTS FAVORING LOCATIONS ALONG
AND SOUTH OF INTERSTATE 94 THROUGH THIS EVENING. THE SNOW EXITS
THE FAR SOUTHERN JAMES RIVER VALLEY AROUND 03Z-06Z FRIDAY.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 128 AM CST THU JAN 14 2016
THE MAIN FORECAST HIGHLIGHT IN THE LONG TERM PERIOD WILL BE WIND
CHILL HIGHLIGHTS FRIDAY NIGHT RIGHT THROUGH THE WEEKEND AND INTO
EARLY NEXT WEEK.
WE BEGIN THE LONG TERM PERIOD ON FRIDAY MORNING WITH ARCTIC AIR
BUILDING OVER THE NORTHERN PLAINS. EXPECT MAINLY CLOUDY SKIES WITH
LOW LEVEL MOISTURE IN PLACE AND A CYCLONIC FLOW ALOFT. A WEAK
SURFACE TROUGH AND BAROCLINIC ZONE REMAINS OVER THE FAR SOUTHWEST
AND THIS WILL BE THE MOST FAVORED LOCATION FOR LIGHT SNOW THROUGH
SATURDAY. ALTHOUGH LIGHT SNOW/FLURRIES CAN NOT BE RULED OUT ACROSS
THE FORECAST AREA FRIDAY AND HAVE A SLIGHT CHANCE OVER A GOOD
PORTION OF THE WEST FRIDAY MORNING. THEN FRIDAY AFTERNOON THROUGH
SATURDAY WE HAVE LIMITED SNOW CHANCES TO MAINLY SOUTHWEST NORTH
DAKOTA. ALTHOUGH SNOW AMOUNTS WILL BE LIGHT...WITH RATIO`S
APPROACHING 20-1 FRIDAY AFTERNOON THROUGH SATURDAY...WE COULD SEE AN
INCH OR TWO ACCUMULATION OVER PORTIONS OF THE SOUTHWEST THROUGH THE
TWO DAY PERIOD.
OTHERWISE...THE MAIN STORY WILL BE WIND CHILLS. EXPECT WIND CHILL
HIGHLIGHTS FRIDAY NIGHT AND THROUGH THE DAY SATURDAY...MAINLY NORTH
AND EAST OF LAKE SAKAKAWEA AND THE MISSOURI RIVER. THEN ACROSS THE
ENTIRE FORECAST AREA SATURDAY NIGHT INTO SUNDAY MORNING. AREAS NORTH
AND EAST OF THE LAKE AND MISSOURI RIVER COULD SEE WIND CHILL WARNING
CRITERIA WIND CHILLS OF 4O TO 45 BELOW ZERO SATURDAY NIGHT INTO
SUNDAY MORNING. THEN SOME MODERATION SUNDAY NIGHT INTO MONDAY
MORNING...BUT WIND CHILL HIGHLIGHT WILL STILL BE NEEDED NORTH AND
EAST. FINALLY MONDAY NIGHT INTO TUESDAY MORNING...PERHAPS ONLY
AREAS FROM THE TURTLE MOUNTAINS INTO THE JAMES RIVER VALLEY MAY
NEED HIGHLIGHTS. AT THIS TIME WE HAVE A MENTION OF THE WIND
CHILLS IN OUR CURRENT SPS WHICH ALSO COVERS THE SHORT TERM
SNOWFALL...AS WELL AS THE HWO.
AFTER DAYTIME HIGHS OF 10 BELOW NORTHEAST TO 10 ABOVE SOUTHWEST
SATURDAY AND SUNDAY...WE BEGIN TO MODERATE NEXT WEEK...ESPECIALLY IN
THE SOUTHWEST WITH HIGHS CLIMBING INTO THE TEENS AND LOWER 20S.
THE SLOW MODERATION IN TEMPERATURES CONTINUES INTO MID WEEK WITH
MINIMAL PRECIPITATION CHANCES IN A NORTHWEST FLOW PATTERN.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 1010 AM CST THU JAN 14 2016
LIGHT RAIN OR FREEZING RAIN EXPECTED AT KDIK/KBIS THROUGH THE
MORNING WITH A GRADUAL CHANGEOVER TO LIGHT SNOW BETWEEN 15Z AND
18Z. OTHERWISE IFR/LIFR AT MOST TERMINALS TODAY. LIGHT SNOW WILL
BE THE MAIN WEATHER TYPE BY AFTERNOON. MVFR TO LOW VFR CIGS
EMERGE AFTER 03Z FRIDAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
FREEZING RAIN ADVISORY UNTIL NOON CST /11 AM MST/ TODAY FOR
NDZ018>020-031>035-040>046.
WINTER WEATHER ADVISORY UNTIL 7 PM CST THIS EVENING FOR NDZ023-
025-037.
&&
$$
UPDATE...CJS
SHORT TERM...KS
LONG TERM...TWH
AVIATION...KS/CJS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
854 AM CST THU JAN 14 2016
.UPDATE...
ISSUED AT 854 AM CST THU JAN 14 2016
QUICK UPDATE TO CANCEL THE FREEZING RAIN ADVISORY FOR WILLIAMS AND
MCKENZIE COUNTIES...WHERE PRECIPITATION HAS TRANSITIONED TO SNOW
WITH THE ONSET OF LOW- AND MID-LEVEL COLD AIR ADVECTION. THE
ADVISORY REMAINS IN PLACE OVER THE REST OF SOUTHWEST AND PARTS OF
SOUTH CENTRAL ND.
WE ARE CLOSELY ASSESSING SNOWFALL POTENTIAL FROM WELLS AND PIERCE
TO FOSTER COUNTIES...WHICH MAY REQUIRE A WINTER WEATHER ADVISORY.
RADAR REFLECTIVITIES HAVE INCREASED UPSTREAM OF THOSE AREAS...AND
MAY IMPLY HEAVIER SNOW RATES WILL DEVELOP DOWNSTREAM IN THE NEXT
FEW HOURS.
UPDATE ISSUED AT 633 AM CST THU JAN 14 2016
WITH A RECENT UPDATE TO ISSUE THE FREEZING RAIN ADVISORY...NO
SIGNIFICANT CHANGES DURING THE PAST HOUR. DID BUMP UP POPS IN THE
FAR SOUTHWEST WITH HIGHER REFLECTIVITIES MOVING INTO BOWMAN AND
SLOPE COUNTIES. WILL NEED TO MONITOR FOR POTENTIAL HEAVIER THAN 3
INCH SNOW AMOUNTS OVER PORTIONS OF THE NORTH CENTRAL INTO THE
NORTHERN JAMES RIVER VALLEY TODAY. UPDATED TEXT PRODUCTS WILL BE
OUT SHORTLY.
UPDATE ISSUED AT 534 AM CST THU JAN 14 2016
UPDATE TO ISSUE A FREEZING RAIN ADVISORY FOR MOST OF WESTERN AND
SOUTH CENTRAL NORTH DAKOTA. RWIS/ROAD TEMPERATURES AT OR BELOW
FREEZING...AND LIGHT FREEZING RAIN BEING REPORTED AT WILLISTON.
WITH MORE PRECIPITATION COMING IN FROM EASTERN MONTANA THIS
MORNING AND THE HRRR PRECIPITATION FORECAST SHOWING IT PUSHING
INTO SOUTH CENTRAL NORTH DAKOTA...WE HAVE DECIDED TO ISSUE A
FREEZING RAIN ADVISORY UNTIL NOON CST. UPDATES TO FORECAST
PRODUCTS BEING SENT AS WE SPEAK.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 128 AM CST THU JAN 14 2016
HIGHLIGHTS IN THE SHORT TERM CENTER AROUND LIGHT FREEZING RAIN
CHANCES SOUTHWEST THROUGH SOUTH CENTRAL UNTIL MID MORNING...AND
SNOW ACCUMULATIONS ACROSS ALL OF WESTERN AND CENTRAL NORTH DAKOTA
THROUGH THIS EVENING...WITH THE HIGHEST AMOUNTS FAVORED IN THE
NORTHERN JAMES RIVER VALLEY.
AFTER COLLABORATING WITH WFO GRAND FORKS...THE DECISION WAS TO
CONTINUE WITH THE SPECIAL WEATHER STATEMENT THIS MORNING FOR BOTH
OFFICES.
THE LATEST SURFACE ANALYSIS CONTINUES TO ADVERTISE A DISTINCT
TEMPERATURE GRADIENT ASSOCIATED WITH A STATIONARY FRONTAL SYSTEM
FROM NEAR SWIFT CURRENT SASKATCHEWAN TO WILLISTON AND GLEN
ULLIN...INTO SELFRIDGE AND ABERDEEN SOUTH DAKOTA. ON THE WARM
SIDE OF THIS BOUNDARY...WEST AND SOUTH OF THE FRONT...TEMPERATURES
ARE IN THE LOW TO MID 30S. EAST AND NORTH OF THE FRONT...TEENS TO
SINGLE DIGITS. WATER VAPOR IMAGERY LOOP SHOWS A PLUME OF MOISTURE
OVERSPREADING WESTERN AND CENTRAL NORTH DAKOTA AS MULTIPLE SHORTWAVES
IN CENTRAL/EASTERN MONTANA ARE PROVIDING THE NECESSARY LARGE SCALE
ASCENT. THROUGH MID MORNING/9AM CST...BUFKIT SOUNDINGS CONTINUE TO
ADVERTISE THAT IF PRECIPITATION IS ABLE TO MAKE IT TO THE
GROUND...THEN MOST LOCATIONS IN SOUTHWEST AND SOUTH CENTRAL NORTH
DAKOTA (THOSE ALONG AND SOUTH OF THE AFOREMENTIONED
BOUNDARY)...WOULD BE FAVORED FOR LIGHT FREEZING RAIN. WILL
CONTINUE TO WATCH OBSERVATIONS UPSTREAM IN EASTERN MONTANA AND
MONITOR AS PRECIPITATION MOVES ACROSS THE BORDER. MAY NEED TO MAKE
QUICK CHANGES EARLY THIS MORNING IF THE SITUATION WARRANTS.
OTHERWISE...SURFACE LOW PRESSURE IN SOUTHERN SASKATCHEWAN WILL
MOVE ALONG THIS BOUNDARY TODAY. WIDESPREAD PRECIPITATION WILL
RESULT WITH CATEGORICAL POPS FOR CENTRAL AND NORTHERN NORTH
DAKOTA. WHEN ASSESSING ANY HEAVY BANDED SNOW POTENTIAL...LOW TO
MID LEVEL FRONTOGENETICAL FORCING AND DEEP LAYER OMEGA ALIGN
TOGETHER BETWEEN 18Z AND 21Z OVER THE NORTHERN JAMES RIVER VALLEY
AND AREAS EAST. THIS IS WHERE WE ARE EXPECTING THE HIGHEST AMOUNTS
OF 3 TO 4 INCHES...WHICH WOULD INCLUDE FOSTER AND WELLS COUNTIES.
THIS IS SHY OF ADVISORY CRITERIA...HOWEVER NOT BY MUCH AND WILL
CLOSELY MONITOR THE HIGHER RESOLUTION MODELS TO SEE IF CHANGES
TAKE PLACE ON THE PLACEMENT AND STRENGTH CURRENTLY SEEN. THE
NAM/GFS/SREF BUFKIT SOUNDINGS AT CARRINGTON SHOW A PEAK OMEGA IN
THE DENDRITIC GROWTH ZONES (-12C TO -18C) AROUND NOON CST...THEN
WANING THEREAFTER. THE OMEGA IS NOT OFF THE CHART...BUT SUGGESTS
ASCENT WILL BE STRONG ENOUGH FOR A PERIOD OF MODERATE SNOW LATE
THIS MORNING INTO THE EARLY AFTERNOON. HENCE THIS IS WHY FOSTER/WELLS
COUNTIES ARE FAVORED FOR THE HIGHEST AMOUNTS. SOUNDINGS SHOW A
RAPID DIMINISH OF THE OMEGA MAX WITHIN THE DENDRITIC GROWTH ZONE
WHEN YOU GET TO JAMESTOWN. SO...TOTAL SNOWFALL ACCUMULATIONS OUTSIDE
OF THE NORTHERN JAMES RIVER VALLEY...EXPECTING 1 TO 3 INCHES NORTH
OF INTERSTATE 94...WITH 1 INCH AMOUNTS FAVORING LOCATIONS ALONG
AND SOUTH OF INTERSTATE 94 THROUGH THIS EVENING. THE SNOW EXITS
THE FAR SOUTHERN JAMES RIVER VALLEY AROUND 03Z-06Z FRIDAY.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 128 AM CST THU JAN 14 2016
THE MAIN FORECAST HIGHLIGHT IN THE LONG TERM PERIOD WILL BE WIND
CHILL HIGHLIGHTS FRIDAY NIGHT RIGHT THROUGH THE WEEKEND AND INTO
EARLY NEXT WEEK.
WE BEGIN THE LONG TERM PERIOD ON FRIDAY MORNING WITH ARCTIC AIR
BUILDING OVER THE NORTHERN PLAINS. EXPECT MAINLY CLOUDY SKIES WITH
LOW LEVEL MOISTURE IN PLACE AND A CYCLONIC FLOW ALOFT. A WEAK
SURFACE TROUGH AND BAROCLINIC ZONE REMAINS OVER THE FAR SOUTHWEST
AND THIS WILL BE THE MOST FAVORED LOCATION FOR LIGHT SNOW THROUGH
SATURDAY. ALTHOUGH LIGHT SNOW/FLURRIES CAN NOT BE RULED OUT ACROSS
THE FORECAST AREA FRIDAY AND HAVE A SLIGHT CHANCE OVER A GOOD
PORTION OF THE WEST FRIDAY MORNING. THEN FRIDAY AFTERNOON THROUGH
SATURDAY WE HAVE LIMITED SNOW CHANCES TO MAINLY SOUTHWEST NORTH
DAKOTA. ALTHOUGH SNOW AMOUNTS WILL BE LIGHT...WITH RATIO`S
APPROACHING 20-1 FRIDAY AFTERNOON THROUGH SATURDAY...WE COULD SEE AN
INCH OR TWO ACCUMULATION OVER PORTIONS OF THE SOUTHWEST THROUGH THE
TWO DAY PERIOD.
OTHERWISE...THE MAIN STORY WILL BE WIND CHILLS. EXPECT WIND CHILL
HIGHLIGHTS FRIDAY NIGHT AND THROUGH THE DAY SATURDAY...MAINLY NORTH
AND EAST OF LAKE SAKAKAWEA AND THE MISSOURI RIVER. THEN ACROSS THE
ENTIRE FORECAST AREA SATURDAY NIGHT INTO SUNDAY MORNING. AREAS NORTH
AND EAST OF THE LAKE AND MISSOURI RIVER COULD SEE WIND CHILL WARNING
CRITERIA WIND CHILLS OF 4O TO 45 BELOW ZERO SATURDAY NIGHT INTO
SUNDAY MORNING. THEN SOME MODERATION SUNDAY NIGHT INTO MONDAY
MORNING...BUT WIND CHILL HIGHLIGHT WILL STILL BE NEEDED NORTH AND
EAST. FINALLY MONDAY NIGHT INTO TUESDAY MORNING...PERHAPS ONLY
AREAS FROM THE TURTLE MOUNTAINS INTO THE JAMES RIVER VALLEY MAY
NEED HIGHLIGHTS. AT THIS TIME WE HAVE A MENTION OF THE WIND
CHILLS IN OUR CURRENT SPS WHICH ALSO COVERS THE SHORT TERM
SNOWFALL...AS WELL AS THE HWO.
AFTER DAYTIME HIGHS OF 10 BELOW NORTHEAST TO 10 ABOVE SOUTHWEST
SATURDAY AND SUNDAY...WE BEGIN TO MODERATE NEXT WEEK...ESPECIALLY IN
THE SOUTHWEST WITH HIGHS CLIMBING INTO THE TEENS AND LOWER 20S.
THE SLOW MODERATION IN TEMPERATURES CONTINUES INTO MID WEEK WITH
MINIMAL PRECIPITATION CHANCES IN A NORTHWEST FLOW PATTERN.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 633 AM CST THU JAN 14 2016
LIGHT FREEZING RAIN EXPECTED AT KDIK/KBIS THROUGH THE MORNING
WITH A GRADUAL CHANGEOVER TO LIGHT SNOW BETWEEN 15Z AND 18Z
THURSDAY. OTHERWISE DETERIORATING CIGS/VSBYS TO IFR/LIFR AT ALL
TERMINALS EARLY IN THE TAF PERIOD. LIGHT SNOW WILL BE THE MAIN
WEATHER TYPE. MVFR TO LOW VFR CIGS EMERGE AFTER 03Z FRIDAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
FREEZING RAIN ADVISORY UNTIL NOON CST /11 AM MST/ TODAY FOR
NDZ018>020-031>035-040>046.
&&
$$
UPDATE...CJS/AC
SHORT TERM...KS
LONG TERM...TWH
AVIATION...KS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
638 AM CST THU JAN 14 2016
.UPDATE...
ISSUED AT 633 AM CST THU JAN 14 2016
WITH A RECENT UPDATE TO ISSUE THE FREEZING RAIN ADVISORY...NO
SIGNIFICANT CHANGES DURING THE PAST HOUR. DID BUMP UP POPS IN THE
FAR SOUTHWEST WITH HIGHER REFLECTIVITIES MOVING INTO BOWMAN AND
SLOPE COUNTIES. WILL NEED TO MONITOR FOR POTENTIAL HEAVIER THAN 3
INCH SNOW AMOUNTS OVER PORTIONS OF THE NORTH CENTRAL INTO THE
NORTHERN JAMES RIVER VALLEY TODAY. UPDATED TEXT PRODUCTS WILL BE
OUT SHORTLY.
UPDATE ISSUED AT 534 AM CST THU JAN 14 2016
UPDATE TO ISSUE A FREEZING RAIN ADVISORY FOR MOST OF WESTERN AND
SOUTH CENTRAL NORTH DAKOTA. RWIS/ROAD TEMPERATURES AT OR BELOW
FREEZING...AND LIGHT FREEZING RAIN BEING REPORTED AT WILLISTON.
WITH MORE PRECIPITATION COMING IN FROM EASTERN MONTANA THIS
MORNING AND THE HRRR PRECIPITATION FORECAST SHOWING IT PUSHING
INTO SOUTH CENTRAL NORTH DAKOTA...WE HAVE DECIDED TO ISSUE A
FREEZING RAIN ADVISORY UNTIL NOON CST. UPDATES TO FORECAST
PRODUCTS BEING SENT AS WE SPEAK.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 128 AM CST THU JAN 14 2016
HIGHLIGHTS IN THE SHORT TERM CENTER AROUND LIGHT FREEZING RAIN
CHANCES SOUTHWEST THROUGH SOUTH CENTRAL UNTIL MID MORNING...AND
SNOW ACCUMULATIONS ACROSS ALL OF WESTERN AND CENTRAL NORTH DAKOTA
THROUGH THIS EVENING...WITH THE HIGHEST AMOUNTS FAVORED IN THE
NORTHERN JAMES RIVER VALLEY.
AFTER COLLABORATING WITH WFO GRAND FORKS...THE DECISION WAS TO
CONTINUE WITH THE SPECIAL WEATHER STATEMENT THIS MORNING FOR BOTH
OFFICES.
THE LATEST SURFACE ANALYSIS CONTINUES TO ADVERTISE A DISTINCT
TEMPERATURE GRADIENT ASSOCIATED WITH A STATIONARY FRONTAL SYSTEM
FROM NEAR SWIFT CURRENT SASKATCHEWAN TO WILLISTON AND GLEN
ULLIN...INTO SELFRIDGE AND ABERDEEN SOUTH DAKOTA. ON THE WARM
SIDE OF THIS BOUNDARY...WEST AND SOUTH OF THE FRONT...TEMPERATURES
ARE IN THE LOW TO MID 30S. EAST AND NORTH OF THE FRONT...TEENS TO
SINGLE DIGITS. WATER VAPOR IMAGERY LOOP SHOWS A PLUME OF MOISTURE
OVERSPREADING WESTERN AND CENTRAL NORTH DAKOTA AS MULTIPLE SHORTWAVES
IN CENTRAL/EASTERN MONTANA ARE PROVIDING THE NECESSARY LARGE SCALE
ASCENT. THROUGH MID MORNING/9AM CST...BUFKIT SOUNDINGS CONTINUE TO
ADVERTISE THAT IF PRECIPITATION IS ABLE TO MAKE IT TO THE
GROUND...THEN MOST LOCATIONS IN SOUTHWEST AND SOUTH CENTRAL NORTH
DAKOTA (THOSE ALONG AND SOUTH OF THE AFOREMENTIONED
BOUNDARY)...WOULD BE FAVORED FOR LIGHT FREEZING RAIN. WILL
CONTINUE TO WATCH OBSERVATIONS UPSTREAM IN EASTERN MONTANA AND
MONITOR AS PRECIPITATION MOVES ACROSS THE BORDER. MAY NEED TO MAKE
QUICK CHANGES EARLY THIS MORNING IF THE SITUATION WARRANTS.
OTHERWISE...SURFACE LOW PRESSURE IN SOUTHERN SASKATCHEWAN WILL
MOVE ALONG THIS BOUNDARY TODAY. WIDESPREAD PRECIPITATION WILL
RESULT WITH CATEGORICAL POPS FOR CENTRAL AND NORTHERN NORTH
DAKOTA. WHEN ASSESSING ANY HEAVY BANDED SNOW POTENTIAL...LOW TO
MID LEVEL FRONTOGENETICAL FORCING AND DEEP LAYER OMEGA ALIGN
TOGETHER BETWEEN 18Z AND 21Z OVER THE NORTHERN JAMES RIVER VALLEY
AND AREAS EAST. THIS IS WHERE WE ARE EXPECTING THE HIGHEST AMOUNTS
OF 3 TO 4 INCHES...WHICH WOULD INCLUDE FOSTER AND WELLS COUNTIES.
THIS IS SHY OF ADVISORY CRITERIA...HOWEVER NOT BY MUCH AND WILL
CLOSELY MONITOR THE HIGHER RESOLUTION MODELS TO SEE IF CHANGES
TAKE PLACE ON THE PLACEMENT AND STRENGTH CURRENTLY SEEN. THE
NAM/GFS/SREF BUFKIT SOUNDINGS AT CARRINGTON SHOW A PEAK OMEGA IN
THE DENDRITIC GROWTH ZONES (-12C TO -18C) AROUND NOON CST...THEN
WANING THEREAFTER. THE OMEGA IS NOT OFF THE CHART...BUT SUGGESTS
ASCENT WILL BE STRONG ENOUGH FOR A PERIOD OF MODERATE SNOW LATE
THIS MORNING INTO THE EARLY AFTERNOON. HENCE THIS IS WHY FOSTER/WELLS
COUNTIES ARE FAVORED FOR THE HIGHEST AMOUNTS. SOUNDINGS SHOW A
RAPID DIMINISH OF THE OMEGA MAX WITHIN THE DENDRITIC GROWTH ZONE
WHEN YOU GET TO JAMESTOWN. SO...TOTAL SNOWFALL ACCUMULATIONS OUTSIDE
OF THE NORTHERN JAMES RIVER VALLEY...EXPECTING 1 TO 3 INCHES NORTH
OF INTERSTATE 94...WITH 1 INCH AMOUNTS FAVORING LOCATIONS ALONG
AND SOUTH OF INTERSTATE 94 THROUGH THIS EVENING. THE SNOW EXITS
THE FAR SOUTHERN JAMES RIVER VALLEY AROUND 03Z-06Z FRIDAY.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 128 AM CST THU JAN 14 2016
THE MAIN FORECAST HIGHLIGHT IN THE LONG TERM PERIOD WILL BE WIND
CHILL HIGHLIGHTS FRIDAY NIGHT RIGHT THROUGH THE WEEKEND AND INTO
EARLY NEXT WEEK.
WE BEGIN THE LONG TERM PERIOD ON FRIDAY MORNING WITH ARCTIC AIR
BUILDING OVER THE NORTHERN PLAINS. EXPECT MAINLY CLOUDY SKIES WITH
LOW LEVEL MOISTURE IN PLACE AND A CYCLONIC FLOW ALOFT. A WEAK
SURFACE TROUGH AND BAROCLINIC ZONE REMAINS OVER THE FAR SOUTHWEST
AND THIS WILL BE THE MOST FAVORED LOCATION FOR LIGHT SNOW THROUGH
SATURDAY. ALTHOUGH LIGHT SNOW/FLURRIES CAN NOT BE RULED OUT ACROSS
THE FORECAST AREA FRIDAY AND HAVE A SLIGHT CHANCE OVER A GOOD
PORTION OF THE WEST FRIDAY MORNING. THEN FRIDAY AFTERNOON THROUGH
SATURDAY WE HAVE LIMITED SNOW CHANCES TO MAINLY SOUTHWEST NORTH
DAKOTA. ALTHOUGH SNOW AMOUNTS WILL BE LIGHT...WITH RATIO`S
APPROACHING 20-1 FRIDAY AFTERNOON THROUGH SATURDAY...WE COULD SEE AN
INCH OR TWO ACCUMULATION OVER PORTIONS OF THE SOUTHWEST THROUGH THE
TWO DAY PERIOD.
OTHERWISE...THE MAIN STORY WILL BE WIND CHILLS. EXPECT WIND CHILL
HIGHLIGHTS FRIDAY NIGHT AND THROUGH THE DAY SATURDAY...MAINLY NORTH
AND EAST OF LAKE SAKAKAWEA AND THE MISSOURI RIVER. THEN ACROSS THE
ENTIRE FORECAST AREA SATURDAY NIGHT INTO SUNDAY MORNING. AREAS NORTH
AND EAST OF THE LAKE AND MISSOURI RIVER COULD SEE WIND CHILL WARNING
CRITERIA WIND CHILLS OF 4O TO 45 BELOW ZERO SATURDAY NIGHT INTO
SUNDAY MORNING. THEN SOME MODERATION SUNDAY NIGHT INTO MONDAY
MORNING...BUT WIND CHILL HIGHLIGHT WILL STILL BE NEEDED NORTH AND
EAST. FINALLY MONDAY NIGHT INTO TUESDAY MORNING...PERHAPS ONLY
AREAS FROM THE TURTLE MOUNTAINS INTO THE JAMES RIVER VALLEY MAY
NEED HIGHLIGHTS. AT THIS TIME WE HAVE A MENTION OF THE WIND
CHILLS IN OUR CURRENT SPS WHICH ALSO COVERS THE SHORT TERM
SNOWFALL...AS WELL AS THE HWO.
AFTER DAYTIME HIGHS OF 10 BELOW NORTHEAST TO 10 ABOVE SOUTHWEST
SATURDAY AND SUNDAY...WE BEGIN TO MODERATE NEXT WEEK...ESPECIALLY IN
THE SOUTHWEST WITH HIGHS CLIMBING INTO THE TEENS AND LOWER 20S.
THE SLOW MODERATION IN TEMPERATURES CONTINUES INTO MID WEEK WITH
MINIMAL PRECIPITATION CHANCES IN A NORTHWEST FLOW PATTERN.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 633 AM CST THU JAN 14 2016
LIGHT FREEZING RAIN EXPECTED AT KISN/KDIK/KBIS THROUGH THE MORNING
WITH A GRADUAL CHANGEOVER TO LIGHT SNOW BETWEEN 15Z AND 18Z
THURSDAY. OTHERWISE DETERIORATING CIGS/VSBYS TO IFR/LIFR AT ALL
TERMINALS EARLY IN THE TAF PERIOD. LIGHT SNOW WILL BE THE MAIN
WEATHER TYPE. MVFR TO LOW VFR CIGS EMERGE AFTER 03Z FRIDAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
FREEZING RAIN ADVISORY UNTIL NOON CST /11 AM MST/ TODAY FOR
NDZ009-017>020-031>035-040>046.
&&
$$
UPDATE...TWH
SHORT TERM...KS
LONG TERM...TWH
AVIATION...KS
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
636 AM CST THU JAN 14 2016
.UPDATE...
ISSUED AT 629 AM CST THU JAN 14 2016
06Z NAM AND GFS AS WELL AS LATEST RUNS OF THE RAP AND HRRR SHOWING
AN UPTURN IN SNOW AMOUNTS ACROSS EXPECTED HEAVIER SNOW BAND
THROUGH THE CENTRAL FA. AS A RESULT HAVE DECIDED TO ISSUE AN
ADVISORY TO COVER EXPECTED 3 TO 5 INCH SNOW TOTALS. NO OTHER
CHANGES MADE.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 310 AM CST THU JAN 14 2016
FORECAST CHALLENGES CONCERN TODAYS SNOW EVENT FOLLOWED BY
TEMPERATURES WITH NEXT ARCTIC INTRUSION. OVERALL MODELS IN PRETTY
GOOD AGREEMENT THROUGH THE PERIOD.
SHORTWAVE ACROSS THE NORTHERN HIGH PLAINS WILL PROPAGATE EAST
ACROSS THE FA TODAY. ASSOCIATED SURFACE LOW WILL TRACK FROM NE MT
SE TO S MN BY THIS EVENING. DEVELOPING AREA OF -SN NORTH OF
SURFACE LOW TRACK WILL BECOME BETTER ORGANIZED DURING THE DAY
AIDED BY FRONTOGENETIC FORCING ALONG BAROCLINIC ZONE. SYNOPTIC
LIFT WITH APPROACHING WAVE WILL MAINTAIN SNOW BAND AS IT
PROPAGATES EAST. MOST AVAILABLE LONG AND SHORT RANGE MODEL
GUIDANCE INDICATING A BAND OF 2-4 INCH SNOWFALL ALONG AND OR JUST SOUTH
OF THE HIGHWAY 2 CORRIDOR. AFTER COLLABORATION WITH NEIGHBORING
OFFICES HAVE DECIDED TO HOLD OFF ON ANY HEADLINES AT THIS POINT.
BESIDES EXPECTED SNOW ACCUMULATIONS NOT EXPECTING ENHANCED
SNOWFALL RATES...NOT OCCURRING DURING HIGHER IMPACT TIME OF DAY
AND WIND WILL NOT BE A SIGNIFICANT ISSUE DURING TIME OF THE SNOW.
THERMAL ADVECTION RELATIVELY NEUTRAL THROUGH THE DAY SO ANY
TEMPERATURE RECOVERY WILL BE MINOR.
-SN WILL BE ENDING FROM NW-SE THIS EVENING EXITING THE FAR SE FA
TOWARDS MORNING. AS THE LOW SHIFTS SE ARCTIC AIR WILL BEGIN FILTER
SOUTHWARD. COULD SEE A BIT STRONGER WIND ON BACK SIDE OF THE LOW
HOWEVER WIND SPEEDS SHOULD GENERALLY BE AT OR BLO 20KTS PRODUCING
SOME DRIFTING AT WORSE.
FRIDAY WILL BE COLD WITH TEMPERATURES STRUGGLING TO MAKE ANY
RECOVERY.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 310 AM CST THU JAN 14 2016
COLD ADVECTION CONTINUES FRIDAY NIGHT AND WITH MIXING WILL ALMOST
CERTAINLY NEED WIND CHILL HEADLINES. MAIN QUESTION WILL BE DEGREE
OF CLOUD COVER WHICH WILL ALSO GOVERN ON HOW COLD WE GET.
COLD ADVECTION WITH APPROACHING ARCTIC HIGH CONTINUES SATURDAY.
ENOUGH WIND FOR DANGEROUS WIND CHILLS THROUGH THE DAY.
MAXIMUM TEMPERATURES AT BEST WILL RISE TO 5 TO 10 BELOW.
COLD ADVECTION FINALLY LEVELS OFF SATURDAY NIGHT. WITH CENTER OF
SURFACE HIGH TO OUR WEST WIND CHILL THREAT CONTINUES ALONG WITH
WIDESPREAD SUB 20 BELOW MINIMUMS.
.EXTENDED (SUNDAY-WEDNESDAY)...AMPLIFIED PATTERN TO START THE PERIOD
WILL GENERALLY FLATTEN A BIT TOWARD MID-WEEK...ALTHOUGH SFC RIDGING
SHOULD INFLUENCE THE REGION THROUGH THE PERIOD. TEMPERATURES
EXPECTED TO MODERATE THROUGH THE PERIOD...WITH NO SIGNIFICANT SIGNAL
FOR SNOWFALL DETECTED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 629 AM CST THU JAN 14 2016
EXPECTING MVFR/IFR CIGS AND VSBY ACROSS TAF SITES AS BAND OF SNOW
SPREADS EAST ACROSS THE REGION TODAY. IMPROVEMENT IN CIGS/VSBY
FROM NW-SE LATE AFTERNOON AND EVENING AS BAND MOVES THROUGH.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WINTER WEATHER ADVISORY UNTIL 7 PM CST THIS EVENING FOR NDZ014-
015-024-026>030-038-039.
MN...WINTER WEATHER ADVISORY UNTIL 7 PM CST THIS EVENING FOR
MNZ001>003-013>017-022>024-027-028.
&&
$$
UPDATE...VOELKER
SHORT TERM...VOELKER
LONG TERM...TG/VOELKER
AVIATION...VOELKER
AREA FORECAST DISCUSSION
NWS BISMARCK ND
540 AM CST THU JAN 14 2016
.UPDATE...
ISSUED AT 534 AM CST THU JAN 14 2016
UPDATE TO ISSUE A FREEZING RAIN ADVISORY FOR MOST OF WESTERN AND
SOUTH CENTRAL NORTH DAKOTA. RWIS/ROAD TEMPERATURES AT OR BELOW
FREEZING...AND LIGHT FREEZING RAIN BEING REPORTED AT WILLISTON.
WITH MORE PRECIPITATION COMING IN FROM EASTERN MONTANA THIS
MORNING AND THE HRRR PRECIPITATION FORECAST SHOWING IT PUSHING
INTO SOUTH CENTRAL NORTH DAKOTA...WE HAVE DECIDED TO ISSUE A
FREEZING RAIN ADVISORY UNTIL NOON CST. UPDATES TO FORECAST
PRODUCTS BEING SENT AS WE SPEAK.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 128 AM CST THU JAN 14 2016
HIGHLIGHTS IN THE SHORT TERM CENTER AROUND LIGHT FREEZING RAIN
CHANCES SOUTHWEST THROUGH SOUTH CENTRAL UNTIL MID MORNING...AND
SNOW ACCUMULATIONS ACROSS ALL OF WESTERN AND CENTRAL NORTH DAKOTA
THROUGH THIS EVENING...WITH THE HIGHEST AMOUNTS FAVORED IN THE
NORTHERN JAMES RIVER VALLEY.
AFTER COLLABORATING WITH WFO GRAND FORKS...THE DECISION WAS TO
CONTINUE WITH THE SPECIAL WEATHER STATEMENT THIS MORNING FOR BOTH
OFFICES.
THE LATEST SURFACE ANALYSIS CONTINUES TO ADVERTISE A DISTINCT
TEMPERATURE GRADIENT ASSOCIATED WITH A STATIONARY FRONTAL SYSTEM
FROM NEAR SWIFT CURRENT SASKATCHEWAN TO WILLISTON AND GLEN
ULLIN...INTO SELFRIDGE AND ABERDEEN SOUTH DAKOTA. ON THE WARM
SIDE OF THIS BOUNDARY...WEST AND SOUTH OF THE FRONT...TEMPERATURES
ARE IN THE LOW TO MID 30S. EAST AND NORTH OF THE FRONT...TEENS TO
SINGLE DIGITS. WATER VAPOR IMAGERY LOOP SHOWS A PLUME OF MOISTURE
OVERSPREADING WESTERN AND CENTRAL NORTH DAKOTA AS MULTIPLE SHORTWAVES
IN CENTRAL/EASTERN MONTANA ARE PROVIDING THE NECESSARY LARGE SCALE
ASCENT. THROUGH MID MORNING/9AM CST...BUFKIT SOUNDINGS CONTINUE TO
ADVERTISE THAT IF PRECIPITATION IS ABLE TO MAKE IT TO THE
GROUND...THEN MOST LOCATIONS IN SOUTHWEST AND SOUTH CENTRAL NORTH
DAKOTA (THOSE ALONG AND SOUTH OF THE AFOREMENTIONED
BOUNDARY)...WOULD BE FAVORED FOR LIGHT FREEZING RAIN. WILL
CONTINUE TO WATCH OBSERVATIONS UPSTREAM IN EASTERN MONTANA AND
MONITOR AS PRECIPITATION MOVES ACROSS THE BORDER. MAY NEED TO MAKE
QUICK CHANGES EARLY THIS MORNING IF THE SITUATION WARRANTS.
OTHERWISE...SURFACE LOW PRESSURE IN SOUTHERN SASKATCHEWAN WILL
MOVE ALONG THIS BOUNDARY TODAY. WIDESPREAD PRECIPITATION WILL
RESULT WITH CATEGORICAL POPS FOR CENTRAL AND NORTHERN NORTH
DAKOTA. WHEN ASSESSING ANY HEAVY BANDED SNOW POTENTIAL...LOW TO
MID LEVEL FRONTOGENETICAL FORCING AND DEEP LAYER OMEGA ALIGN
TOGETHER BETWEEN 18Z AND 21Z OVER THE NORTHERN JAMES RIVER VALLEY
AND AREAS EAST. THIS IS WHERE WE ARE EXPECTING THE HIGHEST AMOUNTS
OF 3 TO 4 INCHES...WHICH WOULD INCLUDE FOSTER AND WELLS COUNTIES.
THIS IS SHY OF ADVISORY CRITERIA...HOWEVER NOT BY MUCH AND WILL
CLOSELY MONITOR THE HIGHER RESOLUTION MODELS TO SEE IF CHANGES
TAKE PLACE ON THE PLACEMENT AND STRENGTH CURRENTLY SEEN. THE
NAM/GFS/SREF BUFKIT SOUNDINGS AT CARRINGTON SHOW A PEAK OMEGA IN
THE DENDRITIC GROWTH ZONES (-12C TO -18C) AROUND NOON CST...THEN
WANING THEREAFTER. THE OMEGA IS NOT OFF THE CHART...BUT SUGGESTS
ASCENT WILL BE STRONG ENOUGH FOR A PERIOD OF MODERATE SNOW LATE
THIS MORNING INTO THE EARLY AFTERNOON. HENCE THIS IS WHY FOSTER/WELLS
COUNTIES ARE FAVORED FOR THE HIGHEST AMOUNTS. SOUNDINGS SHOW A
RAPID DIMINISH OF THE OMEGA MAX WITHIN THE DENDRITIC GROWTH ZONE
WHEN YOU GET TO JAMESTOWN. SO...TOTAL SNOWFALL ACCUMULATIONS OUTSIDE
OF THE NORTHERN JAMES RIVER VALLEY...EXPECTING 1 TO 3 INCHES NORTH
OF INTERSTATE 94...WITH 1 INCH AMOUNTS FAVORING LOCATIONS ALONG
AND SOUTH OF INTERSTATE 94 THROUGH THIS EVENING. THE SNOW EXITS
THE FAR SOUTHERN JAMES RIVER VALLEY AROUND 03Z-06Z FRIDAY.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 128 AM CST THU JAN 14 2016
THE MAIN FORECAST HIGHLIGHT IN THE LONG TERM PERIOD WILL BE WIND
CHILL HIGHLIGHTS FRIDAY NIGHT RIGHT THROUGH THE WEEKEND AND INTO
EARLY NEXT WEEK.
WE BEGIN THE LONG TERM PERIOD ON FRIDAY MORNING WITH ARCTIC AIR
BUILDING OVER THE NORTHERN PLAINS. EXPECT MAINLY CLOUDY SKIES WITH
LOW LEVEL MOISTURE IN PLACE AND A CYCLONIC FLOW ALOFT. A WEAK
SURFACE TROUGH AND BAROCLINIC ZONE REMAINS OVER THE FAR SOUTHWEST
AND THIS WILL BE THE MOST FAVORED LOCATION FOR LIGHT SNOW THROUGH
SATURDAY. ALTHOUGH LIGHT SNOW/FLURRIES CAN NOT BE RULED OUT ACROSS
THE FORECAST AREA FRIDAY AND HAVE A SLIGHT CHANCE OVER A GOOD
PORTION OF THE WEST FRIDAY MORNING. THEN FRIDAY AFTERNOON THROUGH
SATURDAY WE HAVE LIMITED SNOW CHANCES TO MAINLY SOUTHWEST NORTH
DAKOTA. ALTHOUGH SNOW AMOUNTS WILL BE LIGHT...WITH RATIO`S
APPROACHING 20-1 FRIDAY AFTERNOON THROUGH SATURDAY...WE COULD SEE AN
INCH OR TWO ACCUMULATION OVER PORTIONS OF THE SOUTHWEST THROUGH THE
TWO DAY PERIOD.
OTHERWISE...THE MAIN STORY WILL BE WIND CHILLS. EXPECT WIND CHILL
HIGHLIGHTS FRIDAY NIGHT AND THROUGH THE DAY SATURDAY...MAINLY NORTH
AND EAST OF LAKE SAKAKAWEA AND THE MISSOURI RIVER. THEN ACROSS THE
ENTIRE FORECAST AREA SATURDAY NIGHT INTO SUNDAY MORNING. AREAS NORTH
AND EAST OF THE LAKE AND MISSOURI RIVER COULD SEE WIND CHILL WARNING
CRITERIA WIND CHILLS OF 4O TO 45 BELOW ZERO SATURDAY NIGHT INTO
SUNDAY MORNING. THEN SOME MODERATION SUNDAY NIGHT INTO MONDAY
MORNING...BUT WIND CHILL HIGHLIGHT WILL STILL BE NEEDED NORTH AND
EAST. FINALLY MONDAY NIGHT INTO TUESDAY MORNING...PERHAPS ONLY
AREAS FROM THE TURTLE MOUNTAINS INTO THE JAMES RIVER VALLEY MAY
NEED HIGHLIGHTS. AT THIS TIME WE HAVE A MENTION OF THE WIND
CHILLS IN OUR CURRENT SPS WHICH ALSO COVERS THE SHORT TERM
SNOWFALL...AS WELL AS THE HWO.
AFTER DAYTIME HIGHS OF 10 BELOW NORTHEAST TO 10 ABOVE SOUTHWEST
SATURDAY AND SUNDAY...WE BEGIN TO MODERATE NEXT WEEK...ESPECIALLY IN
THE SOUTHWEST WITH HIGHS CLIMBING INTO THE TEENS AND LOWER 20S.
THE SLOW MODERATION IN TEMPERATURES CONTINUES INTO MID WEEK WITH
MINIMAL PRECIPITATION CHANCES IN A NORTHWEST FLOW PATTERN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 128 AM CST THU JAN 14 2016
MAIN MESSAGE FROM NOW THROUGH 15Z THURSDAY WILL BE TO CONVEY THAT
IF PRECIPITATION DOES FALL AT KDIK/KBIS...IT WILL BE IN THE FORM
OF LIGHT FREEZING RAIN. CONFIDENCE OF THIS OCCURRING AT A SPECIFIC
TIME OR DURATION IS LOW...WHICH INHIBITS FROM ADVERTISING THIS IN
ANY ONE PREDOMINATE HOURLY GROUP. PERHAPS A TEMPO GROUP WILL BE
ADDED WITHIN A FEW HOURS FROM NOW IF HIGHER CONFIDENCE DEVELOPS.
OTHERWISE EXPECT DETERIORATING CIGS/VSBYS TO IFR/LIFR AT ALL
TERMINALS EARLY IN THE TAF PERIOD. LIGHT SNOW WILL BE THE MAIN
WEATHER TYPE. MVFR TO LOW VFR CIGS EMERGE AFTER 03Z FRIDAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
FREEZING RAIN ADVISORY UNTIL NOON CST /11 AM MST/ TODAY FOR
NDZ009-017>020-031>035-040>046.
&&
$$
UPDATE...KS
SHORT TERM...KS
LONG TERM...TWH
AVIATION...KS
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1258 AM EST THU JAN 14 2016
.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE AND LIGHT SNOW WILL MOVE EAST TONIGHT.
SOUTHERLY FLOW WILL ALLOW FOR A GRADUAL WARM UP THURSDAY INTO
FRIDAY. ANOTHER UPPER LEVEL DISTURBANCE WILL BRING RAIN TO THE
AREA ON FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
LIGHT SNOW AFFECTING FAR NORTHERN LOCATIONS IS JUST ABOUT OVER AS
A DISTURBANCE MOVES EAST THROUGH THE GREAT LAKES. CLOUDS SHOULD
SHOW A DECREASING TREND AS WELL WITH MID LEVEL MOISTURE DEPARTING
WITH THE DISTURBANCE. IN DEVELOPING SOUTHERLY LOW LEVEL
FLOW FEATURING WARM ADVECTION...EXPECT TEMPS TO SLOWLY RISE UP
INTO THE MID 20S OVERNIGHT.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY NIGHT/...
IN CONTINUED SOUTHERLY FLOW...LOW LEVEL MOISTURE WILL BE ON THE
INCREASE THROUGH THE MORNING HOURS ON THURSDAY. THE 12Z GFS IS
ACTUALLY THE MOST AGGRESSIVE WITH THIS...EVEN TRYING TO SQUEEZE
OUT SOME VERY LIGHT QPF THROUGH THE MORNING HOURS. THE 12Z NAM IS
ALSO TRYING TO SUGGEST THIS...BUT IS SHALLOWER WITH ITS NEAR
SURFACE SATURATED LAYER WHILE THE LATEST RAP IS EVEN LESS
IMPRESSIVE. AS A RESULT...THERE IS QUITE A BIT OF UNCERTAINTY IN
THE POSSIBILITY FOR SOME PATCHY FREEZING DRIZZLE/DRIZZLE THURSDAY
MORNING. SINCE IT IS TOUGH TO RULE IT OUT THOUGH AND IS ALREADY IN
THE FORECAST...WILL GO AHEAD AND HANG ON TO JUST A VERY LOW
CHANCE.
SOUTHERLY FLOW WILL CONTINUE TO INCREASE THURSDAY NIGHT INTO
FRIDAY AHEAD OF AN APPROACHING MID LEVEL SHORT WAVE. THIS WILL
ALLOW FOR DEEPER MOISTURE TO SPREAD NORTH INTO OUR AREA ON FRIDAY.
BETWEEN THIS AND SOME DEVELOPING ISENTROPIC LIFT...EXPECT TO SEE
SOME PCPN WORKING INTO OUR FAR SOUTHWEST POSSIBLY AS EARLY AS
LATE THURSDAY NIGHT AND THEN OVERSPREADING OUR AREA FRIDAY
MORNING AND CONTINUING INTO FRIDAY AFTERNOON. LOW LEVEL THERMAL
FIELDS OFF FORECAST SOUNDINGS SUGGEST THAT WE WILL BE WARM ENOUGH
FOR PRECIPITATION TO BE ALL LIQUID AT ONSET LATE THURSDAY
NIGHT/FRIDAY MORNING. SURFACE TEMPERATURES SHOULD ALSO BE ABOVE
FREEZING SO WILL KEEP PCPN ALL RAIN.
PCPN WILL BEGIN TO TAPER OFF FROM WEST TO EAST FRIDAY NIGHT AS
DRIER AIR FILTERS IN BEHIND A COLD FRONT MOVING THROUGH THE AREA.
AS THE COOLER AIR MOVES IN...SOME OF THE PCPN WILL MIX WITH AND
THEN CHANGE TO SNOW THROUGH THE NIGHT...BUT GIVEN THE DECREASING
MOISTURE...QPF AMOUNTS SHOULD BE FAIRLY LIGHT BY THEN.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
THE LONG TERM PERIOD STARTS OFF WITH LOW PRESSURE HEADING TOWARDS
THE NORTHEAST AND THE POTENTIAL FOR WRAP AROUND SNOW SATURDAY. A
STRONG UPPER LEVEL LOW WILL THEN BEGIN TO ROTATE SOUTHWARDS SATURDAY
EVENING INTO SUNDAY MORNING BRINGING AN ARCTIC COLD FRONT THROUGH
THE REGION. THERE ARE SOME SLIGHT DIFFERENCES BETWEEN THE EURO...
GFS... AND CMC WHICH ALL HAVE CORRESPONDING IMPACTS ON THE TIMING OF
THE ARCTIC FRONT AND IF THERE WILL BE ASSOCIATED PRECIPITATION.
DIFFERENCES START TO OCCUR EARLY SATURDAY MORNING AS A POTENT
SHORTWAVE DIPS DOWN INTO THE TEXAS PANHANDLE.
THE GFS STRENGTHENS THE SHORTWAVE AND STARTS TO SLOW IT DOWN AS IT
PUSHES EAST INTO LOUISIANA SATURDAY EVENING. THE EURO AND CANADIAN
KEEP THE SHORTWAVE MUCH WEAKER AND THE UPPER LEVEL LOW A TAD FURTHER
SOUTH. THE EURO/ CMC SOLUTION FAVORS THE ARCTIC COLD FRONT MOVING
THROUGH THE AREA SATURDAY EVENING. THE GFS SOLUTION HAS THE ARCTIC
FRONT MOVING THROUGH SUNDAY MORNING. GIVEN THE CMC AND EURO ARE A
RELATIVELY CLOSE MATCH HAVE LEANED TOWARDS THIS SOLUTION.
DURING THE DAY SUNDAY 850 MB TEMPERATURES BEGIN TO PLUMMET FROM -7
DEGREES C SATURDAY TO NEAR -20 DEGREES C SUNDAY. THIS WILL MAKE HIGH
TEMPERATURES IN THE TEENS POSSIBLE SUNDAY AS THICKNESSES QUICKLY
FALL. FOR NOW HAVE GONE AHEAD AND JUST TRENDED MAX TEMPS DOWN A BIT
TO FAVOR CMC/EURO. ALSO WITH THE FURTHER SOUTH UPPER LEVEL LOW TRACK
THERE LOOKS TO BE A CHANCE OF SNOW AS STRONG PVA MOVES ACROSS THE
AREA. HAVE BUMPED UP POPS TO CHANCE FOR SUNDAY. MONDAY MORNING
SURFACE HIGH PRESSURE WILL START TO MOVE INTO THE AREA AS THE BEST
AGEOSTROPHIC CONVERGENCE MOVES EAST TOWARDS THE REGION. HIGHS MONDAY
WILL BE WELL BELOW NORMAL AS THE MERCURY ONLY RISES TO THE MIDDLE
TEENS. THIS IS SUPPORTED BY 850 TEMPERATURES AGAIN FORECASTED TO BE
AROUND -20 DEGREES C.
TUESDAY INTO WEDNESDAY THE WARMING TREND WILL START TO COMMENCE AS
SURFACE HIGH PRESSURE SLOWLY SLIDES EAST OF OHIO ALLOWING SOUTHERLY
WINDS TO RETURN. LATE TUESDAY INTO EARLY WEDNESDAY A SHORTWAVE WILL
DIVE SOUTH INTO NORTHERN WISCONSIN AND JUST CLIP NORTHERN OHIO. FOR
NOW HAVE JUST ADDED SLIGHT CHANCE POPS ACROSS THE NORTH TO ACCOUNT
FOR THIS. DURING THE DAY WEDNESDAY MODELS ARE INDICATING A STRONG
SHORTWAVE TRYING TO WRAP UP OVER THE ROCKY MOUNTAINS. THIS LIKELY BE
THE NEXT STORM SYSTEM TO AFFECT THE AREA.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
VFR CONDITIONS WILL CONTINUE THROUGH THE EARLY PART OF THE TAF
PERIOD WITH CIRRUS SPREADING ACROSS THE REGION. HOWEVER
UNCERTAINTY INCREASES SUBSTANTIALLY HEADING INTO THE DAY.
NUMERICAL MODELS INDICATE VERY LOWEST LEVELS OF THE ATMOSPHERE
SATURATING WITH WARM AIR ADVECTION OVER A SNOW PACK. THE QUESTION
IS WHETHER THIS WILL RESULT IN THE DEVELOPMENT OF LOW CLOUDS OR
NOT. GUIDANCE IS NOT IN AGREEMENT WHETHER THERE WILL BE SINKING OR
RISING MOTION IN THE LOWEST LEVELS NOR WHETHER CLOUDS WILL FORM.
ENSEMBLE PROBABILITIES SUGGEST ONLY A CHANCE OF STRATUS AND SO
HAVE OPTED NOT TO INCLUDE A CEILING AT THIS TIME. HAVE RETAINED
SCATTERED LAYER AT 1000 FT TO SUGGEST A POTENTIAL FOR LOWER
CLOUDS. GIVEN LOW CONFIDENCE...AVIATORS WILL HAVE TO MONITOR THIS
CLOSELY. IF STRATUS DOES DEVELOP...THEN THERE WILL BE THE
POTENTIAL FOR SOME DRIZZLE/MIST REDUCING VISIBILITIES. LATE IN THE
TAF PERIOD THERE DOES APPEAR TO BE A BETTER CHANCE OF MVFR
CEILINGS DEVELOPING FROM KDAY TO KCMH/KLCK.
OUTLOOK...MVFR CEILINGS POSSIBLE THURSDAY NIGHT. MVFR TO IFR
CEILINGS AND MVFR VISIBILITIES LIKELY FRIDAY INTO FRIDAY NIGHT.
MVFR CEILINGS MAY LINGER INTO SATURDAY AND SATURDAY NIGHT.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...JGL
NEAR TERM...CONIGLIO/JGL
SHORT TERM...JGL
LONG TERM...HAINES
AVIATION...
AREA FORECAST DISCUSSION
NWS NORMAN OK
934 PM CST FRI JAN 15 2016
.DISCUSSION...
CEILINGS CONTINUE LOWER ACROSS THE TEXAS PANHANDLE AND FAR
WESTERN OKLAHOMA WITHIN AREAS OF LIGHT RADAR RETURNS THIS EVENING.
MODELS ARE SIMILAR IN DEVELOPING PRECIPITATION LATE TONIGHT ALONG
AND NEAR THE 7H TROUGH AXIS WITH HEAVIER AMOUNTS OVER SOUTHWEST
AND SOUTH CENTRAL OKLAHOMA BETWEEN 9-18Z SATURDAY. BETTER LOW
LEVEL COLD ADVECTION WILL REMAIN NORTH AND EAST OF THE AREA...BUT
ENOUGH DRY AIR SHOULD ALLOW SURFACE TEMPERATURES TO COOL TO AROUND
32-34 DEGREES. FOR NOW WILL LEAVE THE WINTER WEATHER ADVISORY THE
SAME...BUT A FEW AREAS SOUTH OF THE ADVISORY(
DUNCAN...WALTERS...FREDERICK AND QUANAH) MAY SEE A PERIOD OF
MODERATE SNOW SATURDAY WITH LITTLE IF ANY ACCUMULATION ON ROADS.
&&
.PREV DISCUSSION... /ISSUED 530 PM CST FRI JAN 15 2016/
AVIATION...
VFR CONDITIONS THIS EVENING WITH LIGHT WINDS. CEILINGS/VIS WILL
LOWER INTO MVFR CAT AND POSSIBLEY IFR AS AREA OF RAIN/SNOW DEVELOP
AND MOVE EAST/SOUTHEAST ACROSS THE AREA OVERNIGHT INTO SATURDAY MORNING.
MVFR CEILINGS MAY LINGER THORUGHOUT THE FORECAST ACROSS WESTERN
SITES WITH VFR IN CENTRAL OK BY AFTN.
30
PREV DISCUSSION... /ISSUED 334 PM CST FRI JAN 15 2016/
DISCUSSION...
ACCUMULATING SNOW LATE TONIGHT INTO SATURDAY IS THE MAIN CONCERN.
EXPANDED THE WINTER WEATHER ADVISORY A BIT FARTHER EAST TO INCLUDE
THE LAWTON...ANADARKO...AND CHICKASHA AREAS BASED ON LATEST MODEL
GUIDANCE...PARTICULARLY THE RUC13 AND HRRR. CONFIDENCE IS RATHER
HIGH THAT 1 TO 3 INCHES OF WET SNOW WILL OCCUR IN THESE AREAS.
TONIGHT...CLOUDS WILL QUICKLY INCREASE. PRECIPITATION WILL BEGIN
IN FAR WESTERN OKLAHOMA AS EARLY AS 10 PM...BUT MAINLY HOLD OFF
UNTIL AFTER 2 AM. MOST PRECIPITATION SHOULD BEGIN AS LIGHT RAIN
DUE TO WARM BOUNDARY LAYER TEMPERATURES NEAR THE GROUND. AS THE
AIR NEAR THE GROUND COOLS AND SATURATES...PRECIPITATION SHOULD
MAINLY CHANGE FROM LIGHT RAIN TO LIGHT TO MODERATE SNOW. A BRIEF
PERIOD OF SLEET MAY OCCUR DURING THIS TRANSITION...BUT WAS NOT
MENTIONED IN THE GRIDS AS RAIN OR SNOW SHOULD BE THE PRIMARY
PRECIPITATION TYPES.
LATEST MODEL GUIDANCE...PARTICULARLY THE HRRR...HAS BEEN DEPICTING
BANDS OF PRECIPITATION OCCURRING LATE TONIGHT INTO SATURDAY
MORNING...LIKELY AS A RESULT OF 850-700 MB FRONTOGENESIS. THESE
BANDS SEEM TO BE MOST LIKELY IN THE 3 AM TO 11 AM TIME FRAME NEAR
AND JUST SOUTH OF I-40 WEST OF OKLAHOMA CITY. THESE BANDS WILL
HAVE THE GREATEST POTENTIAL TO PRODUCE ACCUMULATING SNOWFALL AS
THE SNOW MAY BE MODERATE TO PERHAPS HEAVY AT TIMES WITH
VISIBILITIES FALLING TO 1/2 MILE OR LESS. MODERATE TO HEAVY SNOW
WOULD BE NECESSARY TO ACCUMULATE ON ROADWAYS DUE TO WARM GROUND
TEMPERATURES FROM HEATING THIS AFTERNOON AND YESTERDAY.
BY SATURDAY MORNING...MOST SNOW BANDS APPEAR TO BE OVER
SOUTHWESTERN OKLAHOMA...SLOWLY WEAKENING AFTER 11 AM. RIGHT
NOW...APPEARS THE HEAVIEST SNOW WILL OCCUR SOUTH OF THE OKLAHOMA
CITY METRO AREA AND NORTH OF WICHITA FALLS. LOCATIONS IN SOUTHERN
OKLAHOMA INCLUDING PAULS VALLEY...DUNCAN...AND ADA...MAY BE IN THE
HEAVIEST BANDS OF SNOW AS WELL...THOUGH NOT CONFIDENT THAT THIS
WILL BE THE CASE.
OVERALL...THINK 1 TO 3 INCHES OF SNOWFALL ACCUMULATION IN
ADVISORY AREA SEEM REASONABLE...THOUGH WOULD NOT BE SURPRISED IF
LOCALLY HEAVIER AMOUNTS WOULD BE POSSIBLE IF A MODERATE TO HEAVY
BAND OF SNOW SET UP OVER A GIVEN AREA FOR SEVERAL HOURS. MOST
ACCUMULATIONS WILL BE ON GRASSY SURFACES DUE TO WARM GROUND
SURFACES. SURFACE TEMPERATURES SHOULD STAY NEAR OR JUST ABOVE
FREEZING...32 DEGREES...IN MOST LOCATIONS THAT RECEIVE
ACCUMULATING SNOWFALL.
SATURDAY AFTERNOON THROUGH SUNDAY MORNING...PRECIPITATION CHANCES
WILL END AND SKIES SHOULD CLEAR. WOULD NOT BE SURPRISED IF LIGHT
FOG OR FREEZING FOG FORMED ACROSS SNOW COVERED AREAS...BUT DID
NOT MENTION DUE TO LOW CONFIDENCE OF OCCURRENCE.
SUNDAY AFTERNOON AND NIGHT...A STRONG COLD FRONT WILL MOVE
THROUGH THE AREA AND BRING COLDER TEMPERATURES. MOISTURE APPEARS
TO BE LIMITED WITH THE FRONTAL PASSAGE...THOUGH A FEW LIGHT
SPRINKLES OR SNOW FLURRIES COULD RESULT. THERE IS AN OUTSIDE
CHANCE FOR ADDITIONAL BAND OF SNOWFALL SUNDAY NIGHT SOMEWHERE
ACROSS THE AREA...PARTICULARLY NEAR THE RED RIVER. TEMPERATURES
WILL PLUMMET SUNDAY NIGHT INTO THE TEENS AND 20S.
MONDAY THROUGH FRIDAY...A WARMING TREND WILL OCCUR THROUGH
MIDWEEK. ANOTHER STORM SYSTEM MAY BRING ADDITIONAL PRECIPITATION
CHANCES WEDNESDAY THROUGH FRIDAY...THOUGH PRECIPITATION TYPES AND
AMOUNTS REMAIN UNCERTAIN.
MBS
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 31 43 27 39 / 60 70 0 10
HOBART OK 32 39 28 42 / 60 100 0 10
WICHITA FALLS TX 35 42 29 50 / 20 80 0 10
GAGE OK 25 44 25 31 / 60 20 0 10
PONCA CITY OK 26 43 25 32 / 10 10 0 10
DURANT OK 35 43 29 49 / 10 60 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...WINTER WEATHER ADVISORY UNTIL NOON CST SATURDAY FOR OKZ009-014-
016-021>023-027-033>036-038.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORMAN OK
530 PM CST FRI JAN 15 2016
.AVIATION...
VFR CONDITIONS THIS EVENING WITH LIGHT WINDS. CEILINGS/VIS WILL
LOWER INTO MVFR CAT AND POSSIBLEY IFR AS AREA OF RAIN/SNOW DEVELOP
AND MOVE EAST/SOUTHEAST ACROSS THE AREA OVERNIGHT INTO SATURDAY MORNING.
MVFR CEILINGS MAY LINGER THORUGHOUT THE FORECAST ACROSS WESTERN
SITES WITH VFR IN CENTRAL OK BY AFTN.
30
&&
.PREV DISCUSSION... /ISSUED 334 PM CST FRI JAN 15 2016/
.DISCUSSION...
ACCUMULATING SNOW LATE TONIGHT INTO SATURDAY IS THE MAIN CONCERN.
EXPANDED THE WINTER WEATHER ADVISORY A BIT FARTHER EAST TO INCLUDE
THE LAWTON...ANADARKO...AND CHICKASHA AREAS BASED ON LATEST MODEL
GUIDANCE...PARTICULARLY THE RUC13 AND HRRR. CONFIDENCE IS RATHER
HIGH THAT 1 TO 3 INCHES OF WET SNOW WILL OCCUR IN THESE AREAS.
TONIGHT...CLOUDS WILL QUICKLY INCREASE. PRECIPITATION WILL BEGIN
IN FAR WESTERN OKLAHOMA AS EARLY AS 10 PM...BUT MAINLY HOLD OFF
UNTIL AFTER 2 AM. MOST PRECIPITATION SHOULD BEGIN AS LIGHT RAIN
DUE TO WARM BOUNDARY LAYER TEMPERATURES NEAR THE GROUND. AS THE
AIR NEAR THE GROUND COOLS AND SATURATES...PRECIPITATION SHOULD
MAINLY CHANGE FROM LIGHT RAIN TO LIGHT TO MODERATE SNOW. A BRIEF
PERIOD OF SLEET MAY OCCUR DURING THIS TRANSITION...BUT WAS NOT
MENTIONED IN THE GRIDS AS RAIN OR SNOW SHOULD BE THE PRIMARY
PRECIPITATION TYPES.
LATEST MODEL GUIDANCE...PARTICULARLY THE HRRR...HAS BEEN DEPICTING
BANDS OF PRECIPITATION OCCURRING LATE TONIGHT INTO SATURDAY
MORNING...LIKELY AS A RESULT OF 850-700 MB FRONTOGENESIS. THESE
BANDS SEEM TO BE MOST LIKELY IN THE 3 AM TO 11 AM TIME FRAME NEAR
AND JUST SOUTH OF I-40 WEST OF OKLAHOMA CITY. THESE BANDS WILL
HAVE THE GREATEST POTENTIAL TO PRODUCE ACCUMULATING SNOWFALL AS
THE SNOW MAY BE MODERATE TO PERHAPS HEAVY AT TIMES WITH
VISIBILITIES FALLING TO 1/2 MILE OR LESS. MODERATE TO HEAVY SNOW
WOULD BE NECESSARY TO ACCUMULATE ON ROADWAYS DUE TO WARM GROUND
TEMPERATURES FROM HEATING THIS AFTERNOON AND YESTERDAY.
BY SATURDAY MORNING...MOST SNOW BANDS APPEAR TO BE OVER
SOUTHWESTERN OKLAHOMA...SLOWLY WEAKENING AFTER 11 AM. RIGHT
NOW...APPEARS THE HEAVIEST SNOW WILL OCCUR SOUTH OF THE OKLAHOMA
CITY METRO AREA AND NORTH OF WICHITA FALLS. LOCATIONS IN SOUTHERN
OKLAHOMA INCLUDING PAULS VALLEY...DUNCAN...AND ADA...MAY BE IN THE
HEAVIEST BANDS OF SNOW AS WELL...THOUGH NOT CONFIDENT THAT THIS
WILL BE THE CASE.
OVERALL...THINK 1 TO 3 INCHES OF SNOWFALL ACCUMULATION IN
ADVISORY AREA SEEM REASONABLE...THOUGH WOULD NOT BE SURPRISED IF
LOCALLY HEAVIER AMOUNTS WOULD BE POSSIBLE IF A MODERATE TO HEAVY
BAND OF SNOW SET UP OVER A GIVEN AREA FOR SEVERAL HOURS. MOST
ACCUMULATIONS WILL BE ON GRASSY SURFACES DUE TO WARM GROUND
SURFACES. SURFACE TEMPERATURES SHOULD STAY NEAR OR JUST ABOVE
FREEZING...32 DEGREES...IN MOST LOCATIONS THAT RECEIVE
ACCUMULATING SNOWFALL.
SATURDAY AFTERNOON THROUGH SUNDAY MORNING...PRECIPITATION CHANCES
WILL END AND SKIES SHOULD CLEAR. WOULD NOT BE SURPRISED IF LIGHT
FOG OR FREEZING FOG FORMED ACROSS SNOW COVERED AREAS...BUT DID
NOT MENTION DUE TO LOW CONFIDENCE OF OCCURRENCE.
SUNDAY AFTERNOON AND NIGHT...A STRONG COLD FRONT WILL MOVE
THROUGH THE AREA AND BRING COLDER TEMPERATURES. MOISTURE APPEARS
TO BE LIMITED WITH THE FRONTAL PASSAGE...THOUGH A FEW LIGHT
SPRINKLES OR SNOW FLURRIES COULD RESULT. THERE IS AN OUTSIDE
CHANCE FOR ADDITIONAL BAND OF SNOWFALL SUNDAY NIGHT SOMEWHERE
ACROSS THE AREA...PARTICULARLY NEAR THE RED RIVER. TEMPERATURES
WILL PLUMMET SUNDAY NIGHT INTO THE TEENS AND 20S.
MONDAY THROUGH FRIDAY...A WARMING TREND WILL OCCUR THROUGH
MIDWEEK. ANOTHER STORM SYSTEM MAY BRING ADDITIONAL PRECIPITATION
CHANCES WEDNESDAY THROUGH FRIDAY...THOUGH PRECIPITATION TYPES AND
AMOUNTS REMAIN UNCERTAIN.
MBS
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 31 43 27 39 / 60 70 0 10
HOBART OK 32 39 28 42 / 60 100 0 10
WICHITA FALLS TX 35 42 29 50 / 20 80 0 10
GAGE OK 25 44 25 31 / 60 20 0 10
PONCA CITY OK 26 43 25 32 / 10 10 0 10
DURANT OK 35 43 29 49 / 10 60 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST
SATURDAY FOR OKZ009-014-016-021>023-027-033>036-038.
TX...NONE.
&&
$$
23/17
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
950 AM EST THU JAN 14 2016
.SYNOPSIS...
A WARM FRONT WILL LIFT NORTHEAST THROUGH PENNSYLVANIA BY LATE
TODAY. A DEVELOPING COASTAL LOW WILL TRACK EAST OF THE DELMARVA
PENINSULA FRIDAY NIGHT INTO EARLY SATURDAY. MUCH COLDER AIR WITH
WELL BELOW NORMAL TEMPERATURES...AND AREAS OF MTNS SNOW SHOWERS
AND LAKE EFFECT SNOW...WILL RETURN THIS WEEKEND AND CONTINUE
RIGHT INTO THE MIDDLE OF NEXT WEEK AS A LARGE AREA OF HIGH
PRESSURE DROPS SOUTH OUT OF CANADA AND BECOMES CENTERED OVER THE
CENTRAL U.S.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATEST RADAR SHOWS A SMALL AREA OF LIGHT SNOW RACING QUICKLY ESE
AND AFFECTING THE AREA FROM JUST NORTH OF STATE COLLEGE UP TO THE
NY/PA BORDER. THE HRRR SHOWS THIS WEAKENING OVER THE NEXT FEW
HOURS SO ANY ADDITIONAL ACCUMS WILL BE LIGHT OR NONE. THE LARGER
WEAK WARM ADVECTION PATTERN DOES NOT SHOW SIGNS OF WEAKENING
HOWEVER SO WILL KEEP THE LOW POPS AND MENTION OF LIGHT SNOW IN THE
FORECAST...MAINLY OVER THE NORTH AND WEST INTO THE AFTERNOON.
FOR THE LATE MORNING AND AFTERNOON HOURS...DON`T EXPECT TO SEE
MUCH IN THE WAY OF CLEARING ACROSS MOST OF WESTERN AND NORTHERN
PA. OVER CENTRAL AND SERN AREAS MORE IN THE WAY OF A MIX OF SUN
AND CLOUDS CAN BE EXPECTED.
THE WIND WILL INCREASE TO 10-15MPH...WITH GUSTS UP TO 20 MPH
RANGE DURING THE LATE MORNING AND AFTERNOON HOURS.
HIGH TEMPS THIS AFTERNOON WILL VARY FROM NEAR 30 ACROSS THE
NORTH...TO NEAR 40F ALONG THE MASON/DIXON LINE IN SCENT AND SERN
PENN.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
VARYING AMOUNTS OF MAINLY MID AND HIGH LEVEL CLOUDS /ALTO CU AND
CS/ WILL STREAM ENE ACROSS PENN LATE TODAY THROUGH MUCH OF FRIDAY
WITHIN THE WARM SECTOR AND DEVELOPING SWRLY FLOW ALOFT /AFTER THE
PASSAGE OF A NEG TILT AND LOW AMPLITUDE UPPER RIDGE. NOTHING MORE
THAN A STRAY BRIEF FLURRY /OR SPRINKLE ON FRIDAY/ WILL OCCUR
OCCUR ACROSS THE NRN AND WESTERN MTNS WITHIN THIS 24 HOUR PERIOD.
LOW TEMPS TONIGHT /IN THE U20S TO LOWER 30S/ WILL BE MUCH MILDER
THAN RECENT NIGHTS. HIGHS FRIDAY IN THE LOWER 40S NORTH...AND MID
TO UPPER 40S ACROSS THE SOUTH...WILL BE 10-12F ABOVE NORMAL FOR
MID JANUARY.
CLOUDS WILL THICKEN LATE FRIDAY AND FRIDAY NIGHT...AND MORE
SIGNIFICANT SHOULD SPREAD INTO THE REGION LATER FRIDAY NIGHT INTO
THE UPCOMING WEEKEND. DETAILS BELOW.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
IMPACT WEATHER POTENTIAL:
*ACCUMULATING SNOW POSSIBLE OVER THE WESTERN ALLEGHENIES FRIDAY
NIGHT INTO SATURDAY; CONFIDENCE IS LOW IN PCPN CVRG/TYPE
*SIGNIFICANT LAKE EFFECT SNOW AND SUBZERO WIND CHILLS POSSIBLE
SUNDAY NIGHT INTO EARLY NEXT WEEK
NORTHERN STREAM AMPLIFYING TROUGH AND SURFACE LOW WILL CROSS
THE UPPER MIDWEST AND MOVE THROUGH THE GREAT LAKES THURS NIGHT
THRU FRIDAY. THE GUIDANCE TAKES THE UPPER LEVEL FEATURE IN THE
SOUTHERN STREAM OVER NORTHWEST MEXICO ACROSS TEXAS...FOSTERING
SURFACE LOW DEVELOPMENT NEAR THE GULF COAST BY LATE THURSDAY.
THIS LOW IS FCST TO TRACK ENEWD TO NEAR THE CAROLINA COAST BY
00Z SATURDAY BEFORE RAPIDLY DEEPENING AS IT LIFTS ALONG OR OFF
THE EAST COAST. SOME OF THIS DEEPENING WILL BE TIED TO THE
AFOREMENTIONED NORTHERN STREAM ENERGY CROSSING THE GREAT LAKES
REGION AND SOME IMPLIED PHASING.
THE 12Z UKMET/12Z CMC AND 12Z ECMWF COLLECTIVELY HAVE COME IN A
LITTLE STRONGER AND LEFT OF THE 12Z NAM AND 12Z GFS AS THE SURFACE
LOW CENTER MOVES ACROSS THE SOUTHEAST COASTAL PLAIN...AND THESE
MODELS TEND TO OVERALL REMAIN LEFT OF THE NCEP MODELS AS THE
SYSTEM LIFTS NORTHEAST UP OFF THE EAST COAST THROUGH FRI AND
SAT...BUT THE CMC BECOMES A DECIDED LEFT OUTLIER FROM THE
DELMARVA TO NEW ENGLAND...THE UKMET/ECMWF AND GFS DO ALL SHOW
BETTER AGREEMENT IN TIME OFF THE NEW ENGLAND COAST. THE NAM/SREF
MEAN GENERALLY REMAINS A SLOWER AND FARTHER EAST OUTLIER
THROUGHOUT THE PERIOD. THE 00Z ECENS MEAN FAVORS A UKMET/ECMWF
CONSENSUS AS LOW PRESSURE CROSSES THE SOUTHEAST. THE 12Z GEFS MEAN
SUGGESTS THAT THE DETERMINISTIC GFS IS TOO PROGRESSIVE AND
POSSIBLY A BIT TOO WEAK...AND IF ANYTHING IT TENDS TO SUPPORT THE
ECMWF MORE AT LEAST THROUGH ABOUT 60 HOURS. CONFIDENCE WILL REMAIN
LOW/LIMITED GIVEN THE SPREAD IN DETERMINISTIC MODEL LOW TRACKS AND
THE INDIVIDUAL ECENS AND GEFS MEMBERS. THE GFS/GEFS SHOW ANOTHER
DEEPENING SURFACE LOW TRACKING NEWD ALONG/OFFSHORE THE EAST COAST
ON SUNDAY- SUNDAY NIGHT. CONFIDENCE WITH THIS FEATURE IS
SIGNIFICANTLY LOWER THAN THE PRECEDING LOW GIVEN AN EVEN WIDER
MODEL SPREAD VS. THE ECMWF AND CMC.
THE ONE FEATURE THE MEDIUM RANGE GUIDANCE DOES SEEM TO AGREE ON
IS A MODIFIED ARCTIC HIGH BUILDING SOUTHEAST INTO THE PLAINS BY
THE END OF THE WEEKEND...BRINGING A SURGE OF FRIGID AIR ACROSS THE
GREAT LAKES/OHIO VALLEY AND MID-ATLANTIC STATES INTO EARLY NEXT
WEEK. THE COLD NORTHWEST FLOW PATTERN MAY AGAIN PROVE FAVORABLE
FOR SIGNIFICANT LAKE EFFECT AND OROGRAPHIC SNOWS DOWNWIND OF LAKE
ERIE AND ALONG THE SPINE OF THE ALLEGHENIES. SUBZERO WIND CHILLS
MAY ALSO BE A GOOD BET AT THIS POINT. SOME MODERATION APPEARS
LIKELY INTO THE SECOND HALF OF NEXT WEEK.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
BANDS OF PRECIPITATION MOVING THROUGH CENTRAL PA THIS MORNING
WITH PERIODS OF IFR AT BRADFORD/JOHNSTOWN...AND OCNL MVFR AT
ALTOONA AND STATE COLLEGE. THESE CONDITIONS WILL GRADUALLY
IMPROVE AT ALL TAF SITES EXCEPT BRADFORD WHERE SNOW SHOWERS WILL
KEEP SUB VFR CONDITIONS IN PLACE FOR THE REMAINDER OF THE DAY INTO
THE OVERNIGHT.
MAINLY VFR CONDITIONS WILL CONTINUE INTO THE EVENING BEFORE LOWER
CONDITIONS REDEVELOP...MAINLY OVER THE WESTERN AND NORTHERN HIGHER
ELEVATION SITES WHERE SOME LIGHT RAIN OR EVEN FREEZING DRIZZLE
WILL BE POSSIBLE. REDUCED CONDITIONS WILL CONTINUE INTO FRIDAY
OVER THE WEST AND NORTH...MAINLY VFR ELSEWHERE.
OUTLOOK...
FRI NIGHT INTO SAT...REDUCTIONS LIKELY WITH INCREASING LIKELIHOOD
FOR MAINLY RAIN. SOME SNOW PSBL LATE.
SUN-MON...MVFR/IFR SNOW SHOWERS LAURELS AND NORTHERN
MOUNTAINS. MAINLY VFR ELSEWHERE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/LAMBERT
NEAR TERM...LA CORTE/LAMBERT
SHORT TERM...FITZGERALD/LAMBERT
LONG TERM...STEINBUGL
AVIATION...CERU/MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
757 AM EST THU JAN 14 2016
.SYNOPSIS...
A WARM FRONT WILL LIFT NORTHEAST THROUGH PENNSYLVANIA BY LATE
TODAY. A DEVELOPING COASTAL LOW WILL TRACK EAST OF THE DELMARVA
PENINSULA FRIDAY NIGHT INTO EARLY SATURDAY. MUCH COLDER AIR WITH
WELL BELOW NORMAL TEMPERATURES...AND AREAS OF MTNS SNOW SHOWERS
AND LAKE EFFECT SNOW...WILL RETURN THIS WEEKEND AND CONTINUE
RIGHT INTO THE MIDDLE OF NEXT WEEK AS A LARGE AREA OF HIGH
PRESSURE DROPS SOUTH OUT OF CANADA AND BECOMES CENTERED OVER THE
CENTRAL U.S.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WIDESPREAD LAYERED CLOUDS IN THE FORM OF STRATOCU AND NIMBOSTRATUS
COVERED ALL OF FCST AREA EARLY THIS MORNING...WITH AREAS OF
GENERALLY VERY LIGHT SNOW DRIFTING QUICKLY EAST AT 40-50 KTS.
WESTERLY ISENTROPIC LIFT FOCUSED IN THE 275-285K THETA LAYER WAS
RESPONSIBLE FOR THE LIGHT PRECIP FORMATION.
OPERATIONAL 00Z NAM AND 14/06Z HRRR BOTH SHOW THE PRESENT VERY
LIGHT SNOW DISSOLVING ACROSS THE CENTRAL RIDGE AND VALLEY REGION
DURING THE MID TO LATE MORNING HOURS. THE LAUREL HIGHLANDS AND NW
MTNS COULD EXPERIENCE LIGHT SNOW UNTIL 13-15Z THANKS TO BETTER
OROGRAPHIC LIFT VIA THE SW TO WSW NEAR SFC FLOW...AND/OR CLOSER
PROXIMITY TO A RATHER ILL-DEFINED WARM FRONTAL BOUNDARY.
LIQUID EQUIVALENT QPF WILL AMOUNT TO JUST A FEW TO PERHAPS 5
HUNDREDTHS OF AN INCH AT MOST...WHICH WILL TRANSLATE TO A COATING
TO ONE INCH OF SNOW APPLYING A 15 TO 20:1 SNOW/WATER RATIO.
GREATEST SNOW AMTS WILL OCCUR ACROSS THE NW MTNS OF PENN.
FOR THE LATE MORNING AND AFTERNOON HOURS...I DON/T EXPECT TO SEE
MUCH IN THE WAY OF CLEARING ACROSS MOST OF CENTRAL AND NRN PENN.
SOME THIN SPOTS IN THE OVC WILL DEVELOP THOUGH. THE LOWER SUSQ
VALLEY WILL SEE AT LEAST PARTLY SUNNY SKIES THIS
AFTERNOON...SINCE THEY/LL EXPERIENCE BETTER LLVL DOWNSLOPE
COMPONENT VIA THE WSW LLVL FLOW...AND REMAIN CLOSER TO THE AXIS
OF A SFC RIDGE OVER THE MID ATLANTIC PIEDMONT.
TEMPS HAVE RISEN BETWEEN 2 AND 6 DEG F OVER THE PAST 3 HOURS
THANKS TO THE THICKENING CLOUD COVER AND LLVL WAA. READINGS BY
DAWN WILL RANGE FROM THE L-M TEENS ACROSS THE NORTH...TO THE LOWER
AND MID 20S IN THE SOUTH. HIGHER TERRAIN OVER THE LAURELS WILL
CONTINUE TO SEE SUSTAINED WSW WINDS OF AROUND 15 KTS WITH GUSTS
INTO THE MID AND UPPER 20KT RANGE TODAY. ELSEWHERE...WIND UNDER
10KTS WILL INCREASE TO 7-10 KTS WITH GUSTS IN THE 15-20 KT RANGE
DURING THE LATE MORNING AND AFTERNOON HOURS.
HIGH TEMPS THIS AFTERNOON WILL VARY FROM NEAR 30 ACROSS THE
NORTH...TO NEAR 40F ALONG THE MASON/DIXON LINE IN SCENT AND SERN
PENN.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
VARYING AMOUNTS OF MAINLY MID AND HIGH LEVEL CLOUDS /ALTO CU AND
CS/ WILL STREAM ENE ACROSS PENN LATE TODAY THROUGH MUCH OF FRIDAY
WITHIN THE WARM SECTOR AND DEVELOPING SWRLY FLOW ALOFT /AFTER THE
PASSAGE OF A NEG TILT AND LOW AMPLITUDE UPPER RIDGE. NOTHING MORE
THAN A STRAY BRIEF FLURRY /OR SPRINKLE ON FRIDAY/ WILL OCCUR
OCCUR ACROSS THE NRN AND WESTERN MTNS WITHIN THIS 24 HOUR PERIOD.
LOW TEMPS TONIGHT /IN THE U20S TO LOWER 30S/ WILL BE MUCH MILDER
THAN RECENT NIGHTS. HIGHS FRIDAY IN THE LOWER 40S NORTH...AND MID
TO UPPER 40S ACROSS THE SOUTH...WILL BE 10-12F ABOVE NORMAL FOR
MID JANUARY.
CLOUDS WILL THICKEN LATE FRIDAY AND FRIDAY NIGHT...AND MORE
SIGNIFICANT SHOULD SPREAD INTO THE REGION LATER FRIDAY NIGHT INTO
THE UPCOMING WEEKEND. DETAILS BELOW.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
IMPACT WEATHER POTENTIAL:
*ACCUMULATING SNOW POSSIBLE OVER THE WESTERN ALLEGHENIES FRIDAY
NIGHT INTO SATURDAY; CONFIDENCE IS LOW IN PCPN CVRG/TYPE
*SIGNIFICANT LAKE EFFECT SNOW AND SUBZERO WIND CHILLS POSSIBLE
SUNDAY NIGHT INTO EARLY NEXT WEEK
NORTHERN STREAM AMPLIFYING TROUGH AND SURFACE LOW WILL CROSS
THE UPPER MIDWEST AND MOVE THROUGH THE GREAT LAKES THURS NIGHT
THRU FRIDAY. THE GUIDANCE TAKES THE UPPER LEVEL FEATURE IN THE
SOUTHERN STREAM OVER NORTHWEST MEXICO ACROSS TEXAS...FOSTERING
SURFACE LOW DEVELOPMENT NEAR THE GULF COAST BY LATE THURSDAY.
THIS LOW IS FCST TO TRACK ENEWD TO NEAR THE CAROLINA COAST BY
00Z SATURDAY BEFORE RAPIDLY DEEPENING AS IT LIFTS ALONG OR OFF
THE EAST COAST. SOME OF THIS DEEPENING WILL BE TIED TO THE
AFOREMENTIONED NORTHERN STREAM ENERGY CROSSING THE GREAT LAKES
REGION AND SOME IMPLIED PHASING.
THE 12Z UKMET/12Z CMC AND 12Z ECMWF COLLECTIVELY HAVE COME IN A
LITTLE STRONGER AND LEFT OF THE 12Z NAM AND 12Z GFS AS THE SURFACE
LOW CENTER MOVES ACROSS THE SOUTHEAST COASTAL PLAIN...AND THESE
MODELS TEND TO OVERALL REMAIN LEFT OF THE NCEP MODELS AS THE
SYSTEM LIFTS NORTHEAST UP OFF THE EAST COAST THROUGH FRI AND
SAT...BUT THE CMC BECOMES A DECIDED LEFT OUTLIER FROM THE
DELMARVA TO NEW ENGLAND...THE UKMET/ECMWF AND GFS DO ALL SHOW
BETTER AGREEMENT IN TIME OFF THE NEW ENGLAND COAST. THE NAM/SREF
MEAN GENERALLY REMAINS A SLOWER AND FARTHER EAST OUTLIER
THROUGHOUT THE PERIOD. THE 00Z ECENS MEAN FAVORS A UKMET/ECMWF
CONSENSUS AS LOW PRESSURE CROSSES THE SOUTHEAST. THE 12Z GEFS MEAN
SUGGESTS THAT THE DETERMINISTIC GFS IS TOO PROGRESSIVE AND
POSSIBLY A BIT TOO WEAK...AND IF ANYTHING IT TENDS TO SUPPORT THE
ECMWF MORE AT LEAST THROUGH ABOUT 60 HOURS. CONFIDENCE WILL REMAIN
LOW/LIMITED GIVEN THE SPREAD IN DETERMINISTIC MODEL LOW TRACKS AND
THE INDIVIDUAL ECENS AND GEFS MEMBERS. THE GFS/GEFS SHOW ANOTHER
DEEPENING SURFACE LOW TRACKING NEWD ALONG/OFFSHORE THE EAST COAST
ON SUNDAY- SUNDAY NIGHT. CONFIDENCE WITH THIS FEATURE IS
SIGNIFICANTLY LOWER THAN THE PRECEDING LOW GIVEN AN EVEN WIDER
MODEL SPREAD VS. THE ECMWF AND CMC.
THE ONE FEATURE THE MEDIUM RANGE GUIDANCE DOES SEEM TO AGREE ON
IS A MODIFIED ARCTIC HIGH BUILDING SOUTHEAST INTO THE PLAINS BY
THE END OF THE WEEKEND...BRINGING A SURGE OF FRIGID AIR ACROSS THE
GREAT LAKES/OHIO VALLEY AND MID-ATLANTIC STATES INTO EARLY NEXT
WEEK. THE COLD NORTHWEST FLOW PATTERN MAY AGAIN PROVE FAVORABLE
FOR SIGNIFICANT LAKE EFFECT AND OROGRAPHIC SNOWS DOWNWIND OF LAKE
ERIE AND ALONG THE SPINE OF THE ALLEGHENIES. SUBZERO WIND CHILLS
MAY ALSO BE A GOOD BET AT THIS POINT. SOME MODERATION APPEARS
LIKELY INTO THE SECOND HALF OF NEXT WEEK.
&&
.AVIATION /13Z THURSDAY THROUGH MONDAY/...
BANDS OF PRECIPITATION MOVING THROUGH CENTRAL PA THIS MORNING WITH
PERODS OF IFR AT BFD AND JST...AND MVFR AT AOO AND UNV. THESE
CONDITIONS WILL CONTINUE THROUGH MID MORNING AT THE ABOVE
SITES...UNTIL AROUND 15Z...WITH IMPROVING CONDITIONS AT ALL TAF
SITES EXCEPT BFD. BFD SHOULD CONTINUE TO SEE VSBY AND CIG
RESTRICTIONS THROUGH 15Z...UNTIL THE UPPER LEVEL TROUGH LIFTS
NORTHWARD. VFR SHOULD THEN DOMINATE THROUGH THE REST OF THE
AFTERNOON INTO THE EVENING...WHEN ANOTHER WEAK ROUND OF SHOWERS
COULD BRING MVFR CIGS AND VSBYS TO JST AND BFD...MAINLY AFTER 03Z.
OUTLOOK...
FRI NIGHT INTO SAT...REDUCTIONS LIKELY WITH INCREASING LIKELIHOOD
FOR MAINLY RAIN. SOME SNOW PSBL LATE.
SUN-MON...MVFR/IFR SNOW SHOWERS LAURELS AND NORTHERN
MOUNTAINS. MAINLY VFR ELSEWHERE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD/LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...FITZGERALD/LAMBERT
LONG TERM...STEINBUGL
AVIATION...CERU/MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
407 AM EST THU JAN 14 2016
.SYNOPSIS...
A WARM FRONT WILL LIFT NORTHEAST THROUGH PENNSYLVANIA BY LATE
TODAY. A DEVELOPING COASTAL LOW WILL TRACK EAST OF THE DELMARVA
PENINSULA FRIDAY NIGHT INTO EARLY SATURDAY. MUCH COLDER AIR WITH
WELL BELOW NORMAL TEMPERATURES...AND AREAS OF MTNS SNOW SHOWERS
AND LAKE EFFECT SNOW...WILL RETURN THIS WEEKEND AND CONTINUE
RIGHT INTO THE MIDDLE OF NEXT WEEK AS A LARGE AREA OF HIGH
PRESSURE DROPS SOUTH OUT OF CANADA AND BECOMES CENTERED OVER THE
CENTRAL U.S.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WIDESPREAD LAYERED CLOUDS IN THE FORM OF STRATOCU AND NIMBOSTRATUS
COVERED ALL OF FCST AREA EARLY THIS MORNING...WITH AREAS OF
GENERALLY VERY LIGHT SNOW DRIFTING QUICKLY EAST AT 40-50 KTS.
WESTERLY ISENTROPIC LIFT FOCUSED IN THE 275-285K THETA LAYER WAS
RESPONSIBLE FOR THE LIGHT PRECIP FORMATION.
OPERATIONAL 00Z NAM AND 14/06Z HRRR BOTH SHOW THE PRESENT VERY
LIGHT SNOW DISSOLVING ACROSS THE CENTRAL RIDGE AND VALLEY REGION
DURING THE MID TO LATE MORNING HOURS. THE LAUREL HIGHLANDS AND NW
MTNS COULD EXPERIENCE LIGHT SNOW UNTIL 13-15Z THANKS TO BETTER
OROGRAPHIC LIFT VIA THE SW TO WSW NEAR SFC FLOW...AND/OR CLOSER
PROXIMITY TO A RATHER ILL-DEFINED WARM FRONTAL BOUNDARY.
LIQUID EQUIVALENT QPF WILL AMOUNT TO JUST A FEW TO PERHAPS 5
HUNDREDTHS OF AN INCH AT MOST...WHICH WILL TRANSLATE TO A COATING
TO ONE INCH OF SNOW APPLYING A 15 TO 20:1 SNOW/WATER RATIO.
GREATEST SNOW AMTS WILL OCCUR ACROSS THE NW MTNS OF PENN.
FOR THE LATE MORNING AND AFTERNOON HOURS...I DON/T EXPECT TO SEE
MUCH IN THE WAY OF CLEARING ACROSS MOST OF CENTRAL AND NRN PENN.
SOME THIN SPOTS IN THE OVC WILL DEVELOP THOUGH. THE LOWER SUSQ
VALLEY WILL SEE AT LEAST PARTLY SUNNY SKIES THIS
AFTERNOON...SINCE THEY/LL EXPERIENCE BETTER LLVL DOWNSLOPE
COMPONENT VIA THE WSW LLVL FLOW...AND REMAIN CLOSER TO THE AXIS
OF A SFC RIDGE OVER THE MID ATLANTIC PIEDMONT.
TEMPS HAVE RISEN BETWEEN 2 AND 6 DEG F OVER THE PAST 3 HOURS
THANKS TO THE THICKENING CLOUD COVER AND LLVL WAA. READINGS BY
DAWN WILL RANGE FROM THE L-M TEENS ACROSS THE NORTH...TO THE LOWER
AND MID 20S IN THE SOUTH. HIGHER TERRAIN OVER THE LAURELS WILL
CONTINUE TO SEE SUSTAINED WSW WINDS OF AROUND 15 KTS WITH GUSTS
INTO THE MID AND UPPER 20KT RANGE TODAY. ELSEWHERE...WIND UNDER
10KTS WILL INCREASE TO 7-10 KTS WITH GUSTS IN THE 15-20 KT RANGE
DURING THE LATE MORNING AND AFTERNOON HOURS.
HIGH TEMPS THIS AFTERNOON WILL VARY FROM NEAR 30 ACROSS THE
NORTH...TO NEAR 40F ALONG THE MASON/DIXON LINE IN SCENT AND SERN
PENN.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
VARYING AMOUNTS OF MAINLY MID AND HIGH LEVEL CLOUDS /ALTO CU AND
CS/ WILL STREAM ENE ACROSS PENN LATE TODAY THROUGH MUCH OF FRIDAY
WITHIN THE WARM SECTOR AND DEVELOPING SWRLY FLOW ALOFT /AFTER THE
PASSAGE OF A NEG TILT AND LOW AMPLITUDE UPPER RIDGE. NOTHING MORE
THAN A STRAY BRIEF FLURRY /OR SPRINKLE ON FRIDAY/ WILL OCCUR
OCCUR ACROSS THE NRN AND WESTERN MTNS WITHIN THIS 24 HOUR PERIOD.
LOW TEMPS TONIGHT /IN THE U20S TO LOWER 30S/ WILL BE MUCH MILDER
THAN RECENT NIGHTS. HIGHS FRIDAY IN THE LOWER 40S NORTH...AND MID
TO UPPER 40S ACROSS THE SOUTH...WILL BE 10-12F ABOVE NORMAL FOR
MID JANUARY.
CLOUDS WILL THICKEN LATE FRIDAY AND FRIDAY NIGHT...AND MORE
SIGNIFICANT SHOULD SPREAD INTO THE REGION LATER FRIDAY NIGHT INTO
THE UPCOMING WEEKEND. DETAILS BELOW.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
IMPACT WEATHER POTENTIAL:
*ACCUMULATING SNOW POSSIBLE OVER THE WESTERN ALLEGHENIES FRIDAY
NIGHT INTO SATURDAY; CONFIDENCE IS LOW IN PCPN CVRG/TYPE
*SIGNIFICANT LAKE EFFECT SNOW AND SUBZERO WIND CHILLS POSSIBLE
SUNDAY NIGHT INTO EARLY NEXT WEEK
NORTHERN STREAM AMPLIFYING TROUGH AND SURFACE LOW WILL CROSS
THE UPPER MIDWEST AND MOVE THROUGH THE GREAT LAKES THURS NIGHT
THRU FRIDAY. THE GUIDANCE TAKES THE UPPER LEVEL FEATURE IN THE
SOUTHERN STREAM OVER NORTHWEST MEXICO ACROSS TEXAS...FOSTERING
SURFACE LOW DEVELOPMENT NEAR THE GULF COAST BY LATE THURSDAY.
THIS LOW IS FCST TO TRACK ENEWD TO NEAR THE CAROLINA COAST BY
00Z SATURDAY BEFORE RAPIDLY DEEPENING AS IT LIFTS ALONG OR OFF
THE EAST COAST. SOME OF THIS DEEPENING WILL BE TIED TO THE
AFOREMENTIONED NORTHERN STREAM ENERGY CROSSING THE GREAT LAKES
REGION AND SOME IMPLIED PHASING.
THE 12Z UKMET/12Z CMC AND 12Z ECMWF COLLECTIVELY HAVE COME IN A
LITTLE STRONGER AND LEFT OF THE 12Z NAM AND 12Z GFS AS THE SURFACE
LOW CENTER MOVES ACROSS THE SOUTHEAST COASTAL PLAIN...AND THESE
MODELS TEND TO OVERALL REMAIN LEFT OF THE NCEP MODELS AS THE
SYSTEM LIFTS NORTHEAST UP OFF THE EAST COAST THROUGH FRI AND
SAT...BUT THE CMC BECOMES A DECIDED LEFT OUTLIER FROM THE
DELMARVA TO NEW ENGLAND...THE UKMET/ECMWF AND GFS DO ALL SHOW
BETTER AGREEMENT IN TIME OFF THE NEW ENGLAND COAST. THE NAM/SREF
MEAN GENERALLY REMAINS A SLOWER AND FARTHER EAST OUTLIER
THROUGHOUT THE PERIOD. THE 00Z ECENS MEAN FAVORS A UKMET/ECMWF
CONSENSUS AS LOW PRESSURE CROSSES THE SOUTHEAST. THE 12Z GEFS MEAN
SUGGESTS THAT THE DETERMINISTIC GFS IS TOO PROGRESSIVE AND
POSSIBLY A BIT TOO WEAK...AND IF ANYTHING IT TENDS TO SUPPORT THE
ECMWF MORE AT LEAST THROUGH ABOUT 60 HOURS. CONFIDENCE WILL REMAIN
LOW/LIMITED GIVEN THE SPREAD IN DETERMINISTIC MODEL LOW TRACKS AND
THE INDIVIDUAL ECENS AND GEFS MEMBERS. THE GFS/GEFS SHOW ANOTHER
DEEPENING SURFACE LOW TRACKING NEWD ALONG/OFFSHORE THE EAST COAST
ON SUNDAY- SUNDAY NIGHT. CONFIDENCE WITH THIS FEATURE IS
SIGNIFICANTLY LOWER THAN THE PRECEDING LOW GIVEN AN EVEN WIDER
MODEL SPREAD VS. THE ECMWF AND CMC.
THE ONE FEATURE THE MEDIUM RANGE GUIDANCE DOES SEEM TO AGREE ON
IS A MODIFIED ARCTIC HIGH BUILDING SOUTHEAST INTO THE PLAINS BY
THE END OF THE WEEKEND...BRINGING A SURGE OF FRIGID AIR ACROSS THE
GREAT LAKES/OHIO VALLEY AND MID-ATLANTIC STATES INTO EARLY NEXT
WEEK. THE COLD NORTHWEST FLOW PATTERN MAY AGAIN PROVE FAVORABLE
FOR SIGNIFICANT LAKE EFFECT AND OROGRAPHIC SNOWS DOWNWIND OF LAKE
ERIE AND ALONG THE SPINE OF THE ALLEGHENIES. SUBZERO WIND CHILLS
MAY ALSO BE A GOOD BET AT THIS POINT. SOME MODERATION APPEARS
LIKELY INTO THE SECOND HALF OF NEXT WEEK.
&&
.AVIATION /09Z THURSDAY THROUGH MONDAY/...
BANDS OF PRECIPITATION MOVING THROUGH CENTRAL PA OVERNIGHT.
EXPECT PERIODS OF IFR AT BFD AND JST...AND MVFR AT AOO AND UNV.
THESE CONDITIONS WILL CONTINUE THROUGH MID MORNING AT THE ABOVE
SITES...UNTIL AROUND 12Z...WITH IMPROVING CONDITIONS AT ALL TAF
SITES EXCEPT BFD. BFD SHOULD CONTINUE TO SEE VSBY AND CIG
RESTRICTIONS THROUGH 15Z...UNTIL THE UPPER LEVEL TROUGH LIFTS
NORTHWARD.
VFR SHOULD THEN DOMINATE THROUGH THE REST OF THE AFTERNOON INTO
THE EVENING...WHEN ANOTHER WEAK ROUND OF SHOWERS COULD BRING MVFR
CIGS AND VSBYS TO JST AND BFD...MAINLY AFTER 03Z.
OUTLOOK...
FRI NIGHT INTO SAT...REDUCTIONS LIKELY WITH INCREASING LIKELIHOOD
FOR MAINLY RAIN. SOME SNOW PSBL LATE.
SUN-MON...MVFR/IFR SNOW SHOWERS LAURELS AND NORTHERN
MOUNTAINS. MAINLY VFR ELSEWHERE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD/LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...FITZGERALD/LAMBERT
LONG TERM...STEINBUGL
AVIATION...CERU/MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
331 AM EST THU JAN 14 2016
.SYNOPSIS...
A WARM FRONT WILL LIFT NORTHEAST THROUGH PENNSYLVANIA BY LATE
TODAY. A DEVELOPING COASTAL LOW WILL TRACK EAST OF THE DELMARVA
PENINSULA FRIDAY NIGHT INTO EARLY SATURDAY. MUCH COLDER AIR WITH
WELL BELOW NORMAL TEMPERATURES...AND AREAS OF MTNS SNOW SHOWERS
AND LAKE EFFECT SNOW...WILL RETURN THIS WEEKEND AND CONTINUE
RIGHT INTO THE MIDDLE OF NEXT WEEK AS A LARGE AREA OF HIGH
PRESSURE DROPS SOUTH OUT OF CANADA AND BECOMES CENTERED OVER THE
CENTRAL U.S.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WIDESPREAD LAYERED CLOUDS IN THE FORM OF STRATOCU AND NIMBOSTRATUS
COVERED ALL OF FCST AREA EARLY THIS MORNING...WITH AREAS OF
GENERALLY VERY LIGHT SNOW DRIFTING QUICKLY EAST AT 40-50 KTS.
WESTERLY ISENTROPIC LIFT FOCUSED IN THE 275-285K THETA LAYER WAS
RESPONSIBLE FOR THE LIGHT PRECIP FORMATION.
OPERATIONAL 00Z NAM AND 14/06Z HRRR BOTH SHOW THE PRESENT VERY
LIGHT SNOW DISSOLVING ACROSS THE CENTRAL RIDGE AND VALLEY REGION
DURING THE MID TO LATE MORNING HOURS. THE LAUREL HIGHLANDS AND NW
MTNS COULD EXPERIENCE LIGHT SNOW UNTIL 13-15Z THANKS TO BETTER
OROGRAPHIC LIFT VIA THE SW TO WSW NEAR SFC FLOW...AND/OR CLOSER
PROXIMITY TO A RATHER ILL-DEFINED WARM FRONTAL BOUNDARY.
LIQUID EQUIVALENT QPF WILL AMOUNT TO JUST A FEW TO PERHAPS 5
HUNDREDTHS OF AN INCH AT MOST...WHICH WILL TRANSLATE TO A COATING
TO ONE INCH OF SNOW APPLYING A 15 TO 20:1 SNOW/WATER RATIO.
GREATEST SNOW AMTS WILL OCCUR ACROSS THE NW MTNS OF PENN.
FOR THE LATE MORNING AND AFTERNOON HOURS...I DON/T EXPECT TO SEE
MUCH IN THE WAY OF CLEARING ACROSS MOST OF CENTRAL AND NRN PENN.
SOME THIN SPOTS IN THE OVC WILL DEVELOP THOUGH. THE LOWER SUSQ
VALLEY WILL SEE AT LEAST PARTLY SUNNY SKIES THIS
AFTERNOON...SINCE THEY/LL EXPERIENCE BETTER LLVL DOWNSLOPE
COMPONENT VIA THE WSW LLVL FLOW...AND REMAIN CLOSER TO THE AXIS
OF A SFC RIDGE OVER THE MID ATLANTIC PIEDMONT.
TEMPS HAVE RISEN BETWEEN 2 AND 6 DEG F OVER THE PAST 3 HOURS
THANKS TO THE THICKENING CLOUD COVER AND LLVL WAA. READINGS BY
DAWN WILL RANGE FROM THE L-M TEENS ACROSS THE NORTH...TO THE LOWER
AND MID 20S IN THE SOUTH. HIGHER TERRAIN OVER THE LAURELS WILL
CONTINUE TO SEE SUSTAINED WSW WINDS OF AROUND 15 KTS WITH GUSTS
INTO THE MID AND UPPER 20KT RANGE TODAY. ELSEWHERE...WIND UNDER
10KTS WILL INCREASE TO 7-10 KTS WITH GUSTS IN THE 15-20 KT RANGE
DURING THE LATE MORNING AND AFTERNOON HOURS.
HIGH TEMPS THIS AFTERNOON WILL VARY FROM NEAR 30 ACROSS THE
NORTH...TO NEAR 40F ALONG THE MASON/DIXON LINE IN SCENT AND SERN
PENN.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
VARYING AMOUNTS OF MAINLY MID AND HIGH LEVEL CLOUDS /ALTO CU AND
CS/ WILL STREAM ENE ACROSS PENN LATE TODAY THROUGH MUCH OF FRIDAY
WITHIN THE WARM SECTOR AND DEVELOPING SWRLY FLOW ALOFT /AFTER THE
PASSAGE OF A NEG TILT AND LOW AMPLITUDE UPPER RIDGE. NOTHING MORE
THAN A STRAY BRIEF FLURRY /OR SPRINKLE ON FRIDAY/ WILL OCCUR
OCCUR ACROSS THE NRN AND WESTERN MTNS WITHIN THIS 24 HOUR PERIOD.
LOW TEMPS TONIGHT /IN THE U20S TO LOWER 30S/ WILL BE MUCH MILDER
THAN RECENT NIGHTS. HIGHS FRIDAY IN THE LOWER 40S NORTH...AND MID
TO UPPER 40S ACROSS THE SOUTH...WILL BE 10-12F ABOVE NORMAL FOR
MID JANUARY.
CLOUDS WILL THICKEN LATE FRIDAY AND FRIDAY NIGHT...AND MORE
SIGNIFICANT SHOULD SPREAD INTO THE REGION LATER FRIDAY NIGHT INTO
THE UPCOMING WEEKEND. DETAILS BELOW.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
IMPACT WEATHER POTENTIAL:
*ACCUMULATING SNOW POSSIBLE OVER THE WESTERN ALLEGHENIES FRIDAY
NIGHT INTO SATURDAY; CONFIDENCE IS LOW IN PCPN CVRG/TYPE
*SIGNIFICANT LAKE EFFECT SNOW AND SUBZERO WIND CHILLS POSSIBLE
SUNDAY NIGHT INTO EARLY NEXT WEEK
NORTHERN STREAM AMPLIFYING TROUGH AND SURFACE LOW WILL CROSS
THE UPPER MIDWEST AND MOVE THROUGH THE GREAT LAKES THURS NIGHT
THRU FRIDAY. THE GUIDANCE TAKES THE UPPER LEVEL FEATURE IN THE
SOUTHERN STREAM OVER NORTHWEST MEXICO ACROSS TEXAS...FOSTERING
SURFACE LOW DEVELOPMENT NEAR THE GULF COAST BY LATE THURSDAY.
THIS LOW IS FCST TO TRACK ENEWD TO NEAR THE CAROLINA COAST BY
00Z SATURDAY BEFORE RAPIDLY DEEPENING AS IT LIFTS ALONG OR OFF
THE EAST COAST. SOME OF THIS DEEPENING WILL BE TIED TO THE
AFOREMENTIONED NORTHERN STREAM ENERGY CROSSING THE GREAT LAKES
REGION AND SOME IMPLIED PHASING.
THE 12Z UKMET/12Z CMC AND 12Z ECMWF COLLECTIVELY HAVE COME IN A
LITTLE STRONGER AND LEFT OF THE 12Z NAM AND 12Z GFS AS THE SURFACE
LOW CENTER MOVES ACROSS THE SOUTHEAST COASTAL PLAIN...AND THESE
MODELS TEND TO OVERALL REMAIN LEFT OF THE NCEP MODELS AS THE
SYSTEM LIFTS NORTHEAST UP OFF THE EAST COAST THROUGH FRI AND
SAT...BUT THE CMC BECOMES A DECIDED LEFT OUTLIER FROM THE
DELMARVA TO NEW ENGLAND...THE UKMET/ECMWF AND GFS DO ALL SHOW
BETTER AGREEMENT IN TIME OFF THE NEW ENGLAND COAST. THE NAM/SREF
MEAN GENERALLY REMAINS A SLOWER AND FARTHER EAST OUTLIER
THROUGHOUT THE PERIOD. THE 00Z ECENS MEAN FAVORS A UKMET/ECMWF
CONSENSUS AS LOW PRESSURE CROSSES THE SOUTHEAST. THE 12Z GEFS MEAN
SUGGESTS THAT THE DETERMINISTIC GFS IS TOO PROGRESSIVE AND
POSSIBLY A BIT TOO WEAK...AND IF ANYTHING IT TENDS TO SUPPORT THE
ECMWF MORE AT LEAST THROUGH ABOUT 60 HOURS. CONFIDENCE WILL REMAIN
LOW/LIMITED GIVEN THE SPREAD IN DETERMINISTIC MODEL LOW TRACKS AND
THE INDIVIDUAL ECENS AND GEFS MEMBERS. THE GFS/GEFS SHOW ANOTHER
DEEPENING SURFACE LOW TRACKING NEWD ALONG/OFFSHORE THE EAST COAST
ON SUNDAY- SUNDAY NIGHT. CONFIDENCE WITH THIS FEATURE IS
SIGNIFICANTLY LOWER THAN THE PRECEDING LOW GIVEN AN EVEN WIDER
MODEL SPREAD VS. THE ECMWF AND CMC.
THE ONE FEATURE THE MEDIUM RANGE GUIDANCE DOES SEEM TO AGREE ON
IS A MODIFIED ARCTIC HIGH BUILDING SOUTHEAST INTO THE PLAINS BY
THE END OF THE WEEKEND...BRINGING A SURGE OF FRIGID AIR ACROSS THE
GREAT LAKES/OHIO VALLEY AND MID-ATLANTIC STATES INTO EARLY NEXT
WEEK. THE COLD NORTHWEST FLOW PATTERN MAY AGAIN PROVE FAVORABLE
FOR SIGNIFICANT LAKE EFFECT AND OROGRAPHIC SNOWS DOWNWIND OF LAKE
ERIE AND ALONG THE SPINE OF THE ALLEGHENIES. SUBZERO WIND CHILLS
MAY ALSO BE A GOOD BET AT THIS POINT. SOME MODERATION APPEARS
LIKELY INTO THE SECOND HALF OF NEXT WEEK.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
BANDS OF 1 TO 2SM MILE SNOW SPREADING INTO THE AREA AS OF
11 PM. MINOR CHANGES MADE TO 03Z TAFS.
EARLIER DISCUSSION BELOW.
SOME CLOUDS ACROSS THE NORTH...BUT CLEAR ACROSS THE SOUTH.
SOME LIGHT SNOW SHOWERS...FLURRIES NEAR THE NY BORDER.
WE SHOULD SEE THE CURRENT SCENARIO CONTINUE INTO THE OVERNIGHT
BEFORE A NEW AREA OF LIGHT SNOW BRINGS A RETURN OF
MVFR/IFR...MAINLY TO THE LAURELS UP THROUGH THE NORTHERN
MOUNTAINS FOR TONIGHT...BUT SOME SNOW SHOWERS COULD OCCUR
AT UNV AND AOO.
THE DISTURBANCE THAT WILL BRING THE LIGHT SNOW WILL SHEAR OFF
NORTH OF PA EARLY THURSDAY...WITH MOST TERMINALS BECOMING VFR BY
LATE MORNING OR EARLY AFTERNOON...WITH THE USUAL EXCEPTIONS OF
JST/BFD WHICH AT THIS TIME OF YEAR OFTEN REMAIN STUCK WITH SUB VFR
CONDITIONS.
OUTLOOK...
FRI NIGHT INTO SAT...REDUCTIONS LIKELY WITH INCREASING LIKELIHOOD
FOR MAINLY RAIN. SOME SNOW PSBL LATE.
SUN-MON...MVFR/IFR SNOW SHOWERS LAURELS AND NORTHERN
MOUNTAINS. MAINLY VFR ELSEWHERE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD/LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...LAMBERT
LONG TERM...STEINBUGL
AVIATION...LA CORTE/MARTIN
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
332 PM EST THU JAN 14 2016
.SHORT TERM (TONIGHT AND TOMORROW)...
THE SURFACE HIGH PRESSURE IS NOW TO THE SOUTHEAST OF THE AREA WITH
SOUTHWESTERLY FLOW AROUND THIS HIGH BRINGING IN WARMER AIR AND
MOISTURE. TEMPERATURES AND DEWPOINTS HAVE INCREASED A GOOD BIT OVER
THE LAST 24 HOURS WITH TEMPERATURES IN THE 50S AND DEWPOINTS IN THE
30S. EXPECT SOME LOCATIONS WILL TOP OUT NEAR 60 DEGREES TODAY BUT IT
WILL BE THE WARMEST DAY THROUGHOUT THE FORECAST PERIOD. CURRENT
WATER VAPOR IMAGERY AND RAP UPPER AIR ANALYSIS INDICATES A WEAK
UPPER LEVEL RIDGE IN PLACE...WHICH HAS HELPED TO KEEP SKIES MOSTLY
SUNNY TODAY. BACK TO THE WEST...AN UPPER LEVEL TROUGH IS MOVING
EASTWARD ACROSS TEXAS INTO THE NORTHWESTERN GULF OF MEXICO. UPPER
LEVEL WINDS WILL TAKE ON A SOUTHWESTERLY DIRECTION LATER TONIGHT AS
THE ATMOSPHERE SATURATES FROM THE TOP DOWN. FOR TONIGHT...CLOUD
COVER WILL INCREASE AHEAD OF THE APPROACHING SYSTEM BUT CONDITIONS
SHOULD REMAIN DRY AS IT WILL TAKE SOMETIME FOR THE ATMOSPHERE TO
SATURATE. LOWS TONIGHT WILL BE ABOUT 10-20 DEGREES WARMER THAN LAST
NIGHT WITH VALUES IN THE MID 30S TO LOW 40S. LIGHT RAIN WILL MOVE
INTO THE AREA AFTER 12Z FRIDAY WITH PW VALUES INCREASING TO AROUND
0.75 INCHES. THE BULK OF THE MOISTURE LOOKS TO REMAIN TO THE
SOUTHEAST ACROSS THE CAROLINA CLOSER TO THE LOW TRACK. HOWEVER...DO
EXPECT WIDESPREAD LIGHT PRECIPITATION ACROSS THE AREA DURING THE DAY
FRIDAY WITH HIGHEST CHANCES ACROSS EASTERN PORTIONS OF THE FORECAST
AREA. THE MOISTURE IS RATHER LIMITED AND PRECIPITATION SHOULD BEGIN
TO TAPER OFF SOME BY THE AFTERNOON.
.LONG TERM (FRIDAY NIGHT THROUGH THURSDAY)...
MODELS TRYING TO COME INTO BETTER AGREEMENT DURING THE LONG TERM
BUT OVERALL CONSISTENCY STILL ISN`T TOO GOOD.
FRIDAY NIGHT WE BEGIN THE PERIOD WITH AN UPPER LEVEL TROUGH SWINGING
THROUGH THE AREA WITH COLDER AIR MOVING IN AS THE TROUGH EXITS. IT
LOOKS LIKE WE WILL SEE A CHANGE OVER TO SOME LIGHT SNOW SHOWERS LATE
FRIDAY NIGHT INTO SATURDAY MORNING AS COLDER AIR POURS IN. BY THIS
TIME HOWEVER MOST OF THE MOISTURE ASSOCIATED WITH THIS SYSTEM WILL
BE WELL OFF TO OUR EAST. THE BEST CHANCE FOR THESE LIGHT SNOW
SHOWERS WILL BE ACROSS NETN AND SWVA WHERE MOISTURE LINGERS LONGEST.
SNOW MAY EVEN CHANGE BACK OVER TO LIGHT DRIZZLE BEFORE THE PRECIP
COMPLETELY EXITS AS TEMPS WARM UP ABOVE FREEZING ON SATURDAY. AFTER
THE MORNING PRECIP EXIT THE REST OF SATURDAY LOOKS DRY
WITH HIGHS IN THE UPPER 30S TO MID 40S.
MODELS SEEM TO BE FINALLY STARTING TO AGREE ON THE SATURDAY
NIGHT/SUNDAY SYSTEM. GFS HAS BEEN THE OUTLIER THE PAST FEW DAYS AND
THE LATEST RUN RESEMBLES MORE OF WHAT WE HAVE SEEN FROM THE OTHER
MODELS. MODELS SHOW A LONGWAVE TROUGH DIVING DOWN OUT OF THE
NORTHERN PLAINS AND BRINING ARCTIC AIR WITH IT...WHILE A LOW TREKS
ACROSS THE GULF COAST STATES. GFS IS NOW TRENDING TOWARD KEEPING
THIS LOW SUPPRESSED TO OUR SOUTH AND BRINING VERY LITTLE MOISTURE
THIS FAR NORTH. WILL CONTINUE TO WATCH THE TRENDS...BUT FOR NOW WILL
MENTION SLIGHT CHANCE POPS SATURDAY NIGHT AND SUNDAY WITH A FEW
AREAS OF CHANCE INTO NETN AND SWVA. ANY PRECIP DURING THIS TIME-
FRAME WOULD LIKELY BE IN THE FORM OF SNOW WITH TEMPS BELOW FREEZING.
LITTLE TO NO ACCUMULATION EXCEPTED AT THIS TIME. SUNDAY NIGHT WILL BE
COLD WITH TEMPS IN THE MID TEENS TO LOWER 20S.
MONDAY WILL BE A RATHER RAW DAY AS ARCTIC AIR INFILTRATES THE
REGION. HIGHS ON MONDAY WILL RANGE FROM THE UPPER TEENS TO LOWER
30S...WITH MOST VALLEY LOCATIONS IN THE MID 20S. A WEAK CLIPPER
SYSTEM SWINGS ACROSS THE OHIO RIVER VALLEY MONDAY NIGHT THAT MAY
BRING A FEW LIGHT SNOW SHOWERS ACROSS NETN AND SWVA BUT ONCE
AGAIN...LITTLE TO NO ACCUMULATION DUE TO LIMITED MOISTURE. THE BIG
STORY FOR MONDAY NIGHT WILL BE THE COLD. TEMPS WILL BE ABOUT 10 TO
15 DEGREES BELOW NORMAL WITH TEMPS RANGING FROM THE SINGLE DIGITS TO
UPPER TEENS. TEMPS IMPROVE ON TUESDAY AND WEDNESDAY AS WE GET BACK
INTO THE 30S AND 40S DUE TO HIGH PRESSURE BUILDING IN. SOME MODELS
ARE SHOWING A WEAK WAVE OF ENERGY MOVING THROUGH ON WEDNESDAY SO WILL
INTRODUCE SLIGHT CHANCE POPS FOR WEDNESDAY FOR NOW. THURSDAY IS EVEN
WARMER AS RIDGING CONTINUES TO BUILD WITH TEMPS RISING INTO THE LOW
TO MID 40S.
&&
.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN 40 52 39 47 / 10 50 30 10
KNOXVILLE MCGHEE TYSON AIRPORT, TN 37 51 37 44 / 10 50 30 10
OAK RIDGE, TN 37 50 37 44 / 10 50 30 10
TRI CITIES AIRPORT, TN 33 52 34 43 / 10 70 50 20
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
MA/SR
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
716 PM CST FRI JAN 15 2016
.UPDATE...
HAVE MADE A FEW MINOR TWEAKS TO THE PREVIOUS FORECAST WITH REGARDS
TO THE RAIN/SNOW POTENTIAL ACROSS NORTH TEXAS TOMORROW. IT STILL
APPEARS THAT LOCATIONS ROUGHLY NORTH OF A GRAHAM TO PARIS LINE
HAVE THE HIGHEST CHANCE TO SEE SOME MINOR SNOW ACCUMULATIONS OF
AROUND HALF AN INCH THROUGH THE DAY TOMORROW.
THE LATEST RAP SOUNDINGS INDICATE SATURATED PROFILES THROUGH
-15C WITH SURFACE TEMPERATURES IN THE MID 30S AROUND MIDDAY
TOMORROW FOR OUR EXTREME NORTHWESTERN ZONES. A QUICK BURST OF
MODERATE TO HEAVY PRECIPITATION WOULD CERTAINLY BE CAPABLE OF
YIELDING SOME MINOR ACCUMULATIONS IN THIS AREA IN PARTICULAR. FOR
AREAS SOUTH OF HWY380...IT APPEARS LOW-LEVELS WILL BE TOO WARM FOR
MUCH SNOW TO SURVIVE THE TRIP TO THE SURFACE AND PRECIPITATION
TYPE WILL BE PRIMARILY RAIN WITH A FEW WET FLAKES MIXED IN.
THEREFORE...HAVE LOWERED THE SNOW ACCUMULATION AMOUNTS WITH THIS
UPDATE FOR AREAS ROUGHLY ALONG AND SOUTH OF HWY380.
THE LATEST DATA WILL CONTINUE TO BE ASSESSED AS THE 00Z MODELS
TRICKLE IN.
STALLEY
&&
.AVIATION...
/ISSUED 556 PM CST FRI JAN 15 2016/
OBVIOUSLY MAIN CONCERN THIS FORECAST PERIOD IS THE POTENTIAL FOR
RAIN/SNOW MIX SATURDAY AT METROPLEX TAF SITES. ALL INDICATIONS
FROM THE MODELS CONTINUE TO SUGGEST THAT PRECIPITATION WILL REMAIN
LIQUID...HOWEVER THE UNCERTAINTY IS THAT IF PRECIPITATION IS HEAVY
ENOUGH IT WILL FORCE THE FREEZING LEVEL AND LOW LEVEL TEMPERATURES
DOWNWARD ENOUGH TO SUPPORT SOME SNOW MIXING IN WITH THE RAIN AS
FAR SOUTH AS THE METROPLEX. RIGHT NOW THIS POSSIBILITY IS
SMALL...BUT POSSIBLE IN THE EARLY TO MID AFTERNOON HOURS. THERE
IS HIGH CONFIDENCE THAT SURFACE TEMPERATURES WILL REMAIN ABOVE
FREEZING...BUT ANY RECENTLY ARRIVING AIRCRAFT COULD BE COLD ENOUGH
TO ACCUMULATE ICE FROM PRECIP. WILL SHOW JUST A ONE HOUR TEMPO OF
-RASN IN TAF FROM 20-21Z JUST TO HINT AT MIX POSSIBILITY FOR NOW.
OTHERWISE VFR CONDITIONS WILL PREVAIL THROUGH MID MORNING
SATURDAY. THE APPROACHING UPPER LOW WILL RESULT IN INCREASING HIGH
AND MID CLOUDS. RAIN SHOWERS SHOULD DEVELOP AFTER SUNRISE WITHIN
THE WARM CONVEYOR BELT REGION OF THE UPPER LOW WHERE SOME DECENT
ISENTROPIC LIFT AND STEEP LAPSE RATES WILL EXIST. WILL SHOW LIGHT
SHOWERS AT TAF SITES STARTING AT 13Z. AS A SURFACE LOW MOVES
THROUGH THE REGION...WINDS WILL GO FROM AN EASTERLY DIRECTION
TONIGHT AND IN THE MORNING HOURS TO A NORTHERLY DIRECTION BY
MIDDAY. THE NORTHERLY WINDS WILL INCREASE AND BEGIN TO BRING
COLDER AIR SOUTHWARD DURING THE AFTERNOON...SO WHILE RAIN MAY
START EARLY IN THE DAY...THE CONCERN FOR ANY MIX WOULD BE TOWARD
THE TAIL END OF THE PRECIPITATION EVENT. AS WINDS TURN TO THE
NORTH THE LOW LEVELS WILL SATURATE RESULTING IN MVFR CIGS
PREVAILING DURING THE AFTERNOON HOURS AT ALL TAF SITES. CLEARING
SHOULD OCCUR FROM NORTH TO SOUTH AFTER SUNSET.
TR.92
&&
.PREV DISCUSSION... /ISSUED 331 PM CST FRI JAN 15 2016/
A STRONG SHORTWAVE DISTURBANCE MOVING INTO THE 4 CORNERS AREA OF
THE SOUTHERN ROCKIES WILL MOVE EAST OVER THE HIGH PLAINS TONIGHT...
THEN TX/OK ON SATURDAY. MEANWHILE...HIGH LEVEL CLOUDINESS WILL
INCREASE TONIGHT...THEN MORE LOWER CLOUDINESS ON SATURDAY AS TOP-
DOWN SATURATION OCCURS. A STRONG SURFACE COLD FRONT CURRENTLY
MOVING INTO NORTHEAST CO/NORTHWEST KS/AND NEBRASKA WILL CONTINUE
TO SURGE SOUTHWARD INTO THE RED RIVER VALLEY BY DAYBREAK SATURDAY.
FRONTOGENETICAL FORCING/BANDING INCREASES ALONG THE NORTHERN PART
OF THE SHORTWAVE TRACK FROM THE I-40 CORRIDOR ACROSS CENTRAL
OKLAHOMA INTO THE HIGHWAY 380 CORRIDOR IN NORTH TEXAS BETWEEN
GRAHAM AND GREENVILLE SATURDAY MORNING. CURRENT FORECAST SOUNDING
PROFILES STILL INDICATE A POTENTIAL FOR A LIGHT RAIN/SNOW PROFILE
FOR ESPECIALLY THE MID MORNING TO MID AFTERNOON PERIOD AS THE
SHORTWAVE ALOFT PROGRESSIVELY TRACKS EAST ACROSS THE AREA.
THE STRONGEST FRONTOGENESIS ALOFT SHOULD OCCUR ALONG AND NORTH OF
THE RED RIVER VALLEY FROM GAINESVILLE TO PARIS AND POINTS NORTH.
THESE AREAS COULD SEE THE OCCASIONAL BURST OF SLIGHTLY HEAVIER
RAIN OR POSSIBLE RAIN/SNOW MIX...AS THE DYNAMIC FORCING INCREASES.
THE COMBINATION OF SYSTEM SPEED...THE ELEVATED DRY AIR AND ABOVE
FREEZING TEMPERATURES SHOULD RESULT IN BRIEF ACCUMS OF WET SNOW
FROM A TRACE/DUSTING...TO JUST UNDER INCH ALONG HIGHWAY 82 IN THE
WORSE CASE SCENARIO. SOME MINOR IMPACTS ON TRAVEL COULD OCCUR
ACROSS THE FAR NORTHERN COUNTIES FOR A FEW HOURS...THOUGH ANY WET
SNOW OR SNOW MIXED WITH RAIN WOULD LIKELY KEEP MOST ROADWAYS WET
WITH ACCUMULATIONS OCCURRING MOSTLY ON GRASSY AREAS. NO WINTER
WEATHER ADVISORY WILL BE ISSUED WITH THIS FORECAST PER THE
AFORMENTIONED PARAMETERS DISCUSSED.
IF THE COLD FRONT TIMING SPEEDS UP...OR THE FRONTOGENESIS ALOFT
IS MORE INTENSE THAN EXPECTED...SOME ENHANCED WET-BULB COOLING OF
THE ATMOSPHERIC COLUMN WOULD OCCUR POTENTIALLY INCREASING THE
RAIN/SNOW RATES AND POSSIBLY CAUSING A FEW PROBLEMS BETWEEN 10 AM
AND 3 PM SATURDAY MAINLY NORTH OF DFW. THE IMMEDIATE DFW AREA
SHOULD REMAIN IN GOOD SHAPE IF THE CURRENT PROGRESSIVE FORECAST
TRACK AND TEMPERATURES HOLD. STILL...IT WILL BE A GOOD IDEA TO
STAY ABREAST OF THE LATEST FORECAST THINKING ON SATURDAY MORNING
BEFORE YOU HEAD OUT TO TRAVEL THOSE PARTS OF NORTH TEXAS NORTH OF
I-20. THIS SYSTEM WILL LIFT QUICKLY TO THE EAST OF THE AREA
SATURDAY EVENING WITH RAPID CLEARING FOR A CHILLY NIGHT. ANYWHERE
WHERE RESIDUAL MOISTURE REMAINS ON ROADS NORTH OF I-20 WOULD
LIKELY SEE THE POTENTIAL FOR RE-FREEZING FOR SPOTTY ICY PATCHES.
KEEP THIS IN MIND. WINDS WILL BE BRISK FROM THE NORTH ON SATURDAY
WITH HIGH TEMPERATURES ONLY IN THE 40S FOR MUCH OF THE AREA EXCEPT
PARTS OF CENTRAL TEXAS.
WINDS WILL QUICKLY COME AROUND OUT OF THE SOUTH ON SUNDAY AS
SURFACE CYCLOGENSIS OCCURS ACROSS WEST TEXAS IN ADVANCE OF OUR
NEXT SHORTWAVE. HIGH TEMPERATURES WILL RECOVER INTO THE 50S
AREAWIDE BEFORE THE NEXT COLD FRONT ARRIVES SUNDAY NIGHT INTO
MONDAY MORNING. THIS DISTURBANCE WILL BE MORE MOISTURE-STARVED
HEADING INTO MONDAY THAN THE SYSTEM FOR SATURDAY AND WILL HOLD TO
A DRY FORECAST. HOWEVER...A FEW SPRINKLES OR POSSIBLY FLURRIES
LATE IN THE DAY MONDAY ACROSS THE NORTHEAST HALF OF THE CWA WILL
CERTAINLY BE POSSIBLE. ZONAL FLOW WILL DOMINATE TUESDAY INTO
WEDNESDAY WITH A WARM UP TO BETWEEN 55 AND 65 DEGREES ONCE
AGAIN...AS SURFACE WINDS RETURN FROM THE SOUTH AND BECOME GUSTY
AT TIMES.
A SHORTWAVE WILL MOVE QUICKLY EAST ACROSS THE CENTRAL U.S. TUESDAY
NIGHT AND WEDNESDAY...BUT WILL MAINLY ACT AS A SUPPORT MECHANISM
FOR YET ANOTHER COLD FRONTAL PASSAGE ACROSS NORTH AND CENTRAL TX.
LOW CHANCES FOR FEW LIGHT SHOWERS OR EMBEDDED THUNDER WILL EXIST
EAST OF I-35... BUT NOTHING OF SIGNIFICANCE. A STRONGER SHORTWAVE
DISTURBANCE ARRIVES THURSDAY INTO THURSDAY NIGHT...AS THE LONGWAVE
FLOW ACROSS THE CENTRAL U.S. BECOMES MORE AMPLIFIED CYCLONICALLY.
ONCE AGAIN TEMPERATURES APPEAR TO REMAIN WARM ENOUGH FOR JUST A
CHANCE FOR RAIN WITH ISOLATED THUNDER ONCE AGAIN. RAINFALL AMOUNTS
WILL CONTINUE TO BE LIGHT AS RICH MOISTURE REMAINS CONTAINED SOUTH
AND EAST OF THE FORECAST AREA. HIGHS WILL BE MOSTLY IN THE 50S.
05/
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 41 45 33 53 32 / 5 40 5 0 10
WACO, TX 40 49 32 54 36 / 0 20 5 0 5
PARIS, TX 37 44 31 51 31 / 5 50 10 0 10
DENTON, TX 37 43 29 52 30 / 10 50 0 0 10
MCKINNEY, TX 37 44 31 52 31 / 5 50 5 0 10
DALLAS, TX 41 45 32 52 33 / 5 40 5 0 5
TERRELL, TX 39 46 31 52 33 / 5 50 5 0 5
CORSICANA, TX 41 50 34 54 37 / 0 30 5 0 5
TEMPLE, TX 41 52 33 55 36 / 0 20 0 0 5
MINERAL WELLS, TX 39 45 30 56 31 / 5 30 0 0 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
92/77
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
1010 PM PST FRI JAN 15 2016
...SERIES OF WEATHER SYSTEMS TO IMPACT OUR AREA THROUGH THE END
OF NEXT WEEK WITH THE STRONGEST SYSTEM EXPECTED SUNDAY AFTERNOON
INTO MONDAY MORNING...
.SYNOPSIS...A WEAK SYSTEM WILL SPREAD LIGHT RAIN ACROSS THE REGION
TONIGHT AND SATURDAY MORNING. A SERIES OF WEATHER SYSTEMS WILL
CONTINUE TO IMPACT THE AREA THROUGH AT LEAST THE END OF NEXT
WEEK. THE STRONGEST SYSTEM IS FORECAST TO BRING RAIN...POSSIBLY
HEAVY AT TIMES...ALONG WITH LOCALLY GUSTY WINDS TO THE REGION
FROM SUNDAY AFTERNOON THROUGH MONDAY MORNING.
&&
.DISCUSSION...AS OF 9:00 PM PST FRIDAY...LIGHT RAIN HAS BEGUN TO
SPREAD ACROSS THE NORTH BAY THIS EVENING AS THE LATEST PACIFIC
WEATHER SYSTEM DRAWS CLOSER TO THE CALIFORNIA COAST. RADAR AND
SATELLITE SHOW THAT THE BULK OF THE WARM ADVECTION PRECIP
ASSOCIATED WITH THIS SYSTEM IS STILL OFFSHORE. BASED ON LATEST NAM
AND HRRR MODEL GUIDANCE...EXPECT RAINFALL TO GRADUALLY BECOME
WIDESPREAD OVER THE SF BAY AREA BETWEEN NOW AND MIDNIGHT...AND
THEN DEVELOP ACROSS THE REMAINDER OF OUR FORECAST AREA AFTER
MIDNIGHT. RAINFALL INTENSITY IS EXPECTED TO BE LIGHT FOR THE MOST
PART. HOWEVER...THERE ARE SIGNS THAT RAIN RATES MAY INCREASE LATER
TONIGHT. FOR EXAMPLE...THE MAXIMUM PRECIPITABLE WATER VALUE
OFFSHORE NEAR 35N/125W IS AT A RESPECTABLE 1.5 INCHES. IN
ADDITION...A LIGHTNING STRIKE WAS RECENTLY DETECTED ABOUT 200
MILES WSW OF SAN FRANCISCO...INDICATING THERE IS SOME LOCAL
CONVECTION DEVELOPING ALONG THE INCOMING BOUNDARY.
RAINFALL WILL LIKELY TAPER OFF AROUND SUNRISE SATURDAY...BUT THEN
PICK UP A FEW HOURS LATER AS THE TRAILING COLD FRONT APPROACHES
THE COAST. THE COLD FRONT APPEARS TO BE QUITE WEAK AND IT EXPECTED
TO WEAKEN FURTHER AS IT MOVES ONSHORE ON SATURDAY MORNING. BOTH THE
GFS AND ECMWF END PRECIP BY MIDDAY SATURDAY...BUT THE 00Z NAM
MAINTAINS LIGHT PRECIP ACROSS THE SF BAY AREA THROUGH LATE
SATURDAY AS THE WEAKENING BOUNDARY STALLS AND TRANSITIONS INTO A
WARM FRONT OUT AHEAD OF THE NEXT SYSTEM. THE MODELS GENERALLY
AGREE THAT RAIN TOTALS WILL MOSTLY BE IN THE QUARTER TO HALF INCH
RANGE...EXCEPT LESS ACROSS THE FAR SOUTHERN PORTION OF OUR CWA
AND LOCALLY MORE IN THE NORTH BAY. THE HRRR FORECASTS SIMILAR
RAINFALL TOTALS FOR LOCATIONS SOUTH OF THE GOLDEN GATE...BUT IS
WETTER IN THE NORTH BAY...FORECASTING FROM A HALF INCH TO AN INCH
ACROSS SONOMA...NAPA AND MARIN COUNTIES THROUGH SATURDAY
AFTERNOON.
THE NEXT SYSTEM...THE STRONGEST/WETTEST ANTICIPATED OVER THE NEXT
SEVEN DAYS...CAN CURRENTLY BE SEEN ON IR SATELLITE IMAGERY
BEGINNING TO TAKE SHAPE OUT NEAR 37N/152W. THIS SYSTEM WILL
STEADILY APPROACH THE COAST OVER THE NEXT 24 HOURS AND BEGIN TO
SPREAD RAIN INTO THE NORTH BAY BY LATE SATURDAY NIGHT. BUT THE
MAIN FRONTAL BOUNDARY AND BULK OF THE PRECIPITATION WILL REMAIN TO
THE NORTH OF OUR FORECAST AREA THROUGH MIDDAY SUNDAY. THEN...ON
SUNDAY AFTERNOON THE BOUNDARY WILL BEGIN TO SAG SOUTH...WITH
RAINFALL EXPECTED TO INTENSIFY IN THE NORTH BAY BY MID AFTERNOON.
A BAND OF MODERATE TO LOCALLY HEAVY RAIN IS THEN EXPECTED TO
GRADUALLY PRESS SOUTH ACROSS THE REMAINDER OF OUR FORECAST AREA
FROM LATE SUNDAY AFTERNOON THROUGH MONDAY MORNING. WAVES
TRAVELING ALONG THIS BOUNDARY MAY TEMPORARILY STALL THE BAND OF
HEAVIEST RAIN FOR A FEW HOURS AND POSSIBLY RESULT IN LOCAL URBAN
FLOODING OF LOW-LYING OR POORLY DRAINED AREAS FROM SUNDAY EVENING
THROUGH MONDAY MORNING. THE MONDAY MORNING COMMUTE COULD BE
IMPACTED QUITE SIGNIFICANTLY...ESPECIALLY FOR THE SOUTHERN HALF OF
OUR AREA.
RAIN TOTALS WITH THE SUNDAY/MONDAY SYSTEM ARE FORECAST TO RANGE
FROM 0.5-1.5" AT LOWER ELEVATIONS AND FROM 1.5-3" IN THE HILLS.
WINDS ARE NOT EXPECTED TO BE A SIGNIFICANT ISSUE WITH THESE
STORMS...EXCEPT IN COASTAL AREAS FROM SAN MATEO COUNTY NORTHWARD
ON SUNDAY WHEN SOUTHERLY WINDS MAY GUST AS HIGH AS 35 MPH.
A MOIST WESTERLY FLOW WILL CONTINUE TO BRING PERIODS OF RAIN TO
OUR AREA FROM MONDAY AFTERNOON ON THROUGH THE END OF NEXT WEEK.
HOWEVER...THERE PRESENTLY IS NOT EXPECTED TO BE ANY STRONG
ORGANIZED STORMS FOR MUCH OF THE WEEK UNTIL PERHAPS ON FRIDAY WHEN
AN UPPER TROUGH APPROACHES THE COAST AND TRIGGERS MORE INTENSE
RAINFALL AT WEEK`S END.
&&
.AVIATION...AS OF 10:00 PM PST FRIDAY...FOR 06Z TAFS. DOPPLER
RADAR SHOWS RAIN SPREADING ACROSS THE BAY AREA AT THIS HOUR. RAIN
WILL TURN TO SHOWERS OVERNIGHT WITH SHOWERS PERSISTING INTO THE
DAY SATURDAY. CIGS AND VSBYS WILL GRADUALLY LOWER OVERNIGHT. LIGHT
TO MODERATE SOUTHEASTERLY WINDS WILL PREVAIL...WITH BRIEF VARIABLE
SHIFTS TO OTHER DIRECTIONS.
VICINITY OF KSFO...RAIN WILL TURN TO SHOWERS OVERNIGHT WITH
SHOWERS CONTINUING THROUGH MIDDAY SATURDAY. SOUTHEAST WINDS WILL
PREVAIL THROUGH MUCH OF THE FORECAST PERIOD. HEAVIEST RAIN
CURRENTLY EXPECTED BETWEEN 06-10Z TONIGHT.
SFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...LIGHT WINDS WILL TURN SOUTHEAST
WINDS WITH INCREASING MID CLOUDS BEGINNING AROUND 06Z. RAIN AND
CIGS LOWERING TO MVFR/IFR RANGE AROUND 08Z. HEAVIEST RAIN SLOTTED
BETWEEN 08-011Z TONIGHT.
&&
.MARINE...AS OF 8:43 PM PST FRIDAY...SOUTHERLY WINDS WILL
INCREASE AS THE APPROACHING FRONTAL SYSTEM MOVES ACROSS THE
COASTAL WATERS TONIGHT AND SATURDAY. THE STRONGEST WINDS WILL BE
OVER THE NORTHERN OUTER WATERS. A LARGE LONG PERIOD SWELL WILL
MOVE INTO THE FORECAST AREA SATURDAY AFTERNOON AND PERSIST THROUGH
THE HOLIDAY WEEKEND BEFORE EASING EARLY NEXT WEEK
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...SCA...PT ARENA TO PT REYES 0-10 NM
SCA...PT ARENA TO PIGEON PT 10-60 NM
SCA...PT REYES TO PIGEON PT 0-10 NM FROM 2 AM
SCA...ROUGH BAR ADVISORY FOR SF BAR FROM 2 AM
&&
$$
PUBLIC FORECAST: DYKEMA
AVIATION: CW
MARINE: CW
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK AND TWITTER AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
904 PM PST FRI JAN 15 2016
...SERIES OF WEATHER SYSTEMS TO IMPACT OUR AREA THROUGH THE END
OF NEXT WEEK WITH THE STRONGEST SYSTEM EXPECTED SUNDAY AFTERNOON
INTO MONDAY MORNING...
.SYNOPSIS...A WEAK SYSTEM WILL SPREAD LIGHT RAIN ACROSS THE REGION
TONIGHT AND SATURDAY MORNING. A SERIES OF WEATHER SYSTEMS WILL
CONTINUE TO IMPACT THE AREA THROUGH AT LEAST THE END OF NEXT
WEEK. THE STRONGEST SYSTEM IS FORECAST TO BRING RAIN...POSSIBLY
HEAVY AT TIMES...ALONG WITH LOCALLY GUSTY WINDS TO THE REGION
FROM SUNDAY AFTERNOON THROUGH MONDAY MORNING.
&&
.DISCUSSION...AS OF 9:00 PM PST FRIDAY...LIGHT RAIN HAS BEGUN TO
SPREAD ACROSS THE NORTH BAY THIS EVENING AS THE LATEST PACIFIC
WEATHER SYSTEM DRAWS CLOSER TO THE CALIFORNIA COAST. RADAR AND
SATELLITE SHOW THAT THE BULK OF THE WARM ADVECTION PRECIP
ASSOCIATED WITH THIS SYSTEM IS STILL OFFSHORE. BASED ON LATEST NAM
AND HRRR MODEL GUIDANCE...EXPECT RAINFALL TO GRADUALLY BECOME
WIDESPREAD OVER THE SF BAY AREA BETWEEN NOW AND MIDNIGHT...AND
THEN DEVELOP ACROSS THE REMAINDER OF OUR FORECAST AREA AFTER
MIDNIGHT. RAINFALL INTENSITY IS EXPECTED TO BE LIGHT FOR THE MOST
PART. HOWEVER...THERE ARE SIGNS THAT RAIN RATES MAY INCREASE LATER
TONIGHT. FOR EXAMPLE...THE MAXIMUM PRECIPITABLE WATER VALUE
OFFSHORE NEAR 35N/125W IS AT A RESPECTABLE 1.5 INCHES. IN
ADDITION...A LIGHTNING STRIKE WAS RECENTLY DETECTED ABOUT 200
MILES WSW OF SAN FRANCISCO...INDICATING THERE IS SOME LOCAL
CONVECTION DEVELOPING ALONG THE INCOMING BOUNDARY.
RAINFALL WILL LIKELY TAPER OFF AROUND SUNRISE SATURDAY...BUT THEN
PICK UP A FEW HOURS LATER AS THE TRAILING COLD FRONT APPROACHES
THE COAST. THE COLD FRONT APPEARS TO BE QUITE WEAK AND IT EXPECTED
TO WEAKEN FURTHER AS IT MOVES ONSHORE ON SATURDAY MORNING. BOTH THE
GFS AND ECMWF END PRECIP BY MIDDAY SATURDAY...BUT THE 00Z NAM
MAINTAINS LIGHT PRECIP ACROSS THE SF BAY AREA THROUGH LATE
SATURDAY AS THE WEAKENING BOUNDARY STALLS AND TRANSITIONS INTO A
WARM FRONT OUT AHEAD OF THE NEXT SYSTEM. THE MODELS GENERALLY
AGREE THAT RAIN TOTALS WILL MOSTLY BE IN THE QUARTER TO HALF INCH
RANGE...EXCEPT LESS ACROSS THE FAR SOUTHERN PORTION OF OUR CWA
AND LOCALLY MORE IN THE NORTH BAY. THE HRRR FORECASTS SIMILAR
RAINFALL TOTALS FOR LOCATIONS SOUTH OF THE GOLDEN GATE...BUT IS
WETTER IN THE NORTH BAY...FORECASTING FROM A HALF INCH TO AN INCH
ACROSS SONOMA...NAPA AND MARIN COUNTIES THROUGH SATURDAY
AFTERNOON.
THE NEXT SYSTEM...THE STRONGEST/WETTEST ANTICIPATED OVER THE NEXT
SEVEN DAYS...CAN CURRENTLY BE SEEN ON IR SATELLITE IMAGERY
BEGINNING TO TAKE SHAPE OUT NEAR 37N/152W. THIS SYSTEM WILL
STEADILY APPROACH THE COAST OVER THE NEXT 24 HOURS AND BEGIN TO
SPREAD RAIN INTO THE NORTH BAY BY LATE SATURDAY NIGHT. BUT THE
MAIN FRONTAL BOUNDARY AND BULK OF THE PRECIPITATION WILL REMAIN TO
THE NORTH OF OUR FORECAST AREA THROUGH MIDDAY SUNDAY. THEN...ON
SUNDAY AFTERNOON THE BOUNDARY WILL BEGIN TO SAG SOUTH...WITH
RAINFALL EXPECTED TO INTENSIFY IN THE NORTH BAY BY MID AFTERNOON.
A BAND OF MODERATE TO LOCALLY HEAVY RAIN IS THEN EXPECTED TO
GRADUALLY PRESS SOUTH ACROSS THE REMAINDER OF OUR FORECAST AREA
FROM LATE SUNDAY AFTERNOON THROUGH MONDAY MORNING. WAVES
TRAVELING ALONG THIS BOUNDARY MAY TEMPORARILY STALL THE BAND OF
HEAVIEST RAIN FOR A FEW HOURS AND POSSIBLY RESULT IN LOCAL URBAN
FLOODING OF LOW-LYING OR POORLY DRAINED AREAS FROM SUNDAY EVENING
THROUGH MONDAY MORNING. THE MONDAY MORNING COMMUTE COULD BE
IMPACTED QUITE SIGNIFICANTLY...ESPECIALLY FOR THE SOUTHERN HALF OF
OUR AREA.
RAIN TOTALS WITH THE SUNDAY/MONDAY SYSTEM ARE FORECAST TO RANGE
FROM 0.5-1.5" AT LOWER ELEVATIONS AND FROM 1.5-3" IN THE HILLS.
WINDS ARE NOT EXPECTED TO BE A SIGNIFICANT ISSUE WITH THESE
STORMS...EXCEPT IN COASTAL AREAS FROM SAN MATEO COUNTY NORTHWARD
ON SUNDAY WHEN SOUTHERLY WINDS MAY GUST AS HIGH AS 35 MPH.
A MOIST WESTERLY FLOW WILL CONTINUE TO BRING PERIODS OF RAIN TO
OUR AREA FROM MONDAY AFTERNOON ON THROUGH THE END OF NEXT WEEK.
HOWEVER...THERE PRESENTLY IS NOT EXPECTED TO BE ANY STRONG
ORGANIZED STORMS FOR MUCH OF THE WEEK UNTIL PERHAPS ON FRIDAY WHEN
AN UPPER TROUGH APPROACHES THE COAST AND TRIGGERS MORE INTENSE
RAINFALL AT WEEK`S END.
&&
.AVIATION...AS OF 4:00 PM PST FRIDAY...FOR 00Z TAFS. APPROACHING
STORM SYSTEM WILL BRING RAIN TO THE AREA FROM NORTHWEST TO
SOUTHEAST BTWN 03Z SAT THROUGH 15Z SAT...THEN LINGERING RAIN
SHOWERS THROUGH 03Z SUN. CIGS WILL DETERIORATE INTO MVFR RANGE
EARLY IN THE EVENT... AND DROP INTO IFR RANGE FOR SOME LOCATIONS
AFTER 10-12Z SAT AND REMAIN IN IFR-MVFR RANGE THROUGH SATURDAY
MORNING. PREDOMINATELY SOUTH TO SOUTHEAST WINDS WILL PREVAIL
THROUGH THE TAF PERIOD... WITH BRIEF VARIABLE SHIFTS TO OTHER
DIRECTIONS.
VICINITY OF KSFO... VFR THROUGH 03Z SAT... THEN DETERIORATING CIGS
DOWN TO MVFR RANGE THROUGH REMAINDER OF TAF PERIOD. RA TO SHRA
FROM 05Z THROUGH END OF TAF PERIOD. PREDOMINATELY EAST WINDS
THROUGH THE MORNING THEN SOUTHEAST WINDS WILL PREVAIL THROUGH
MIDDAY SATURDAY. HEAVIEST RAIN CURRENTLY EXPECTED BETWEEN 06-10Z
SAT.
SFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...VFR CIGS WITH LIGHT VARIABLE WINDS
THROUGH THE DAYLIGHT HOURS. LIGHT SOUTHEAST WINDS AND INCREASING
MID CLOUDS BEGINNING AROUND 05-06Z SAT THEN DETERIORATING CIGS TO
MVFR/IFR RANGE AFTER 08-10Z. HEAVIEST RAIN SLOTTED BETWEEN 08-011Z
SAT.
&&
.MARINE...AS OF 8:43 PM PST FRIDAY...SOUTHERLY WINDS WILL
INCREASE AS THE APPROACHING FRONTAL SYSTEM MOVES ACROSS THE
COASTAL WATERS TONIGHT AND SATURDAY. THE STRONGEST WINDS WILL BE
OVER THE NORTHERN OUTER WATERS. A LARGE LONG PERIOD SWELL WILL
MOVE INTO THE FORECAST AREA SATURDAY AFTERNOON AND PERSIST THROUGH
THE HOLIDAY WEEKEND BEFORE EASING EARLY NEXT WEEK
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...SCA...PT ARENA TO PIGEON PT 10-60 NM
SCA...PT ARENA TO PT REYES 0-10 NM FROM 8 PM
SCA...PT REYES TO PIGEON PT 0-10 NM FROM 2 AM
SCA...ROUGH BAR ADVISORY FOR SF BAR FROM 2 AM
&&
$$
PUBLIC FORECAST: DYKEMA
AVIATION: DRP/CW
MARINE: CW
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK AND TWITTER AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
849 PM PST FRI JAN 15 2016
.SYNOPSIS... A WEAK WARM FRONT JUST OFFSHORE WILL GENERATE SOME
LIGHT RAIN ALONG THE COAST INTO THE NIGHT...BUT SHOULD END BY
MORNING. VARIABLE CLOUDINESS WILL CONTINUE THROUGH THE HOLIDAY
WEEKEND BUT IT SHOULD REMAIN DRY AND TEMPERATURES WILL MODERATE UNDER
A WEAK HIGH PRESSURE RIDGE. ADDITIONAL MOISTURE WILL ARRIVE WITH A
WEAK PACIFIC TROUGH AROUND TUESDAY...WHICH WILL BRING A CHANCE OF
MORE LIGHT SHOWERS. THEN...FAIR AND DRY THROUGH FRIDAY.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
UPDATED FORECAST TO CONTINUE PATCHY LIGHT RAIN/DRIZZLE ALONG THE SAN
DIEGO COUNTY COAST FOR A FEW MORE HOURS...
AREAS OF LIGHT RAIN AND DRIZZLE WERE OCCURRING ALONG THE SAN DIEGO
COUNTY COAST THIS EVENING. RAINFALL MEASUREMENTS HAVE BEEN VERY
LIGHT. AT 8 PM PST...BANDS OF WEAK RADAR ECHOES CONTINUED TO
DEVELOP OVER THE BIGHT AND DRIFT SLOWLY SE. IR/FOG IMAGERY SHOWED
EXTENSIVE CLOUD COVER WEST OF THE MTS. THE 00Z MIRAMAR SOUNDING HAD A
WEAK INVERSION NEAR 6K FT AND WAS SATURATED BELOW TO AROUND 2500 FT.
WINDS WERE LESS THAN 5 KT BELOW 2500 FT...THEN INCREASED WITH HEIGHT
FROM THE NW. THE SURFACE PRESSURE GRADIENT SHOWED WEAK ONSHORE
TRENDS FROM THE LOWER DESERTS...BUT WEAK OFFSHORE FROM THE NE. THE
GUSTY WESTERLY WINDS THAT WERE PRESENT EARLIER TODAY HAD DECREASED
AND WERE BELOW 25 MPH...EXCEPT LOCALLY BELOW THE WINDIER DESERT
PASSES.
MODELS SHOW MODERATE...LOW LEVEL WARM ADVECTION AROUND 5K FT OVER
THE CA BIGHT...EXTENDING TO THE COAST OF SAN DIEGO COUNTY.
OVERRUNNING OF MOIST PACIFIC AIR NEAR THE COAST SEEMS TO BE THE
MECHANISM FOR THE LIGHT PRECIPITATION OCCURRING THIS EVENING. THE
HIRES WRFEMS AND HRRR MODELS SHOW THIS PATTERN BREAKING DOWN AFTER
MIDNIGHT...WITH THE LIGHT PRECIP ENDING BEFORE DAWN.
EVEN THOUGH THE LIGHT PRECIP WILL END AND THE LOWER CLOUDS SHOULD
BREAK...HIGHER CLOUDS WILL CONTINUE TO DRIFT OVER SOCAL FROM THE
NW...LEAVING SKIES PARTLY CLOUDY. WITH THE ADDITIONAL SUN...DAYTIME
TEMPERATURES SHOULD BE A BIT WARMER. WARMING WILL CONTINUE UNDER FAIR
SKIES ON SUNDAY UNDER A BUILDING SHORT WAVE RIDGE...BEFORE THE NEXT
DISTURBANCE SLIDES EAST OFF THE PACIFIC AND HIGH CLOUDS THICKEN.
OTHERWISE...THE LONGWAVE PATTERN HOLDS THROUGH NEXT WEEK WITH AN
UNDERLYING HIGH PRESSURE RIDGE OVER THE SW...AND NUMEROUS SHORTWAVES
WEAKENING AS THEY MOVE THROUGH IT. IN THIS PATTERN...CENTRAL AND
NORTHERN CA SHOULD REMAIN THE PRIMARY FOCUS FOR MULTIPLE EPISODES OF
MDT-HVY PRECIP...WITH THE RAIN CHANCE DECREASING FROM NORTH TO SOUTH.
THAT LEAVES SOCAL WITH SOME CHANCE POPS AT TIMES...BUT NO PROSPECTS
FOR SUBSTANTIAL RAIN FOR ABOUT THE NEXT TEN DAYS.
FOR NEXT WEEK LOOK FOR TEMPERATURES GENERALLY NEAR TO SLIGHTLY ABOVE
AVERAGE...AND PERIODS OF HIGH CLOUDS. THERE IS A CHANCE FOR PRECIP
ABOUT TUESDAY...AND PERHAPS AGAIN NEXT WEEKEND. BUT PROSPECTS ARE
SHAKY THEN...BASED ON THE VARIOUS MODELS...SO POPS ARE CURRENTLY
BELOW THRESHOLD FRI/SAT.
&&
.AVIATION...
150415Z...COAST/VALLEYS...BKN LOW CLOUDS WITH BASES BETWEEN 2500 AND
3500 FT MSL AND TOPS FROM 4500 TO 6000 FT MSL WILL CONTINUE INTO
SATURDAY MORNING. LIGHT SHOWERS/DRIZZLE WILL BE POSSIBLE ALONG THE
SD COUNTY COAST THROUGH 09Z. THE LOW CLOUDS SHOULD TRANSITION TO SCT
FROM NORTH TO SOUTH BETWEEN 12Z AND 17Z SATURDAY. SCT CLOUDS AND
LIGHT WINDS WILL PREVAIL SATURDAY AFTERNOON...WITH THE POTENTIAL FOR
BKN CIGS BETWEEN 1500 AND 2500 FT RETURNING TO COASTAL AREAS AFTER
04Z SUNDAY.
MTNS/DESERTS...FEW-SCT NEAR 20000 FT MSL AND UNRESTRICTED VIS
THROUGH SATURDAY EVENING.
&&
.MARINE...
815 PM...A LARGE LONG PERIOD WEST-NORTHWEST SWELL WILL MOVE INTO THE
SOCAL BIGHT ON SUNDAY. AS A CONSEQUENCE...8 TO 12 FEET SEAS ARE
EXPECTED SUNDAY THROUGH TUESDAY...WITH THE HIGHEST SEAS OCCURRING
SOUTH OF A LINE FROM SAN CLEMENTE ISLAND TO LA JOLLA. SEAS WILL FALL
BELOW 10 FT BY WEDNESDAY.
&&
.BEACHES...
815 PM...PREDOMINANTLY 2-4 FT SURF WITH LOCAL SETS TO 5 FT WILL
CONTINUE THROUGH SATURDAY. A NEW NORTHWEST SWELL WILL BRING BUILDING
SURF ON SUNDAY...WITH A PEAK IN SURF HEIGHTS EXPECTED MONDAY.
HIGHEST SURF ON MONDAY WILL OCCUR SOUTH OF CARLSBAD...WHERE SURF OF
8-12 FT AND LOCAL SETS TO 14 FT WILL BE POSSIBLE. SURF OF 8-10 FT
WITH LOCAL SETS TO 12 FT WILL ALSO BE POSSIBLE NORTH OF NEWPORT
BEACH. A SLOW DECREASE IN SURF WILL BEGINNING TUESDAY AND CONTINUE
THROUGH NEXT FRIDAY. A HIGH SURF ADVISORY REMAINS IN EFFECT FOR
SUNDAY THROUGH TUESDAY.
&&
.SKYWARN...
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...HIGH SURF ADVISORY FROM 4 AM SUNDAY TO 5 PM PST TUESDAY FOR
ORANGE COUNTY COASTAL AREAS-SAN DIEGO COUNTY COASTAL AREAS.
PZ...NONE.
&&
$$
PUBLIC...JAD
AVIATION/MARINE/BEACHES...BA
AREA FORECAST DISCUSSION
NWS NEW YORK NY
101 AM EST SAT JAN 16 2016
.SYNOPSIS...
A RAPIDLY INTENSIFYING LOW WILL ACCELERATE NORTHEAST...PASSING
SOUTHEAST OF LONG ISLAND SATURDAY MORNING AND THEN EAST OF NEW
ENGLAND LATER SATURDAY. WEAK HIGH PRESSURE WILL MOVE IN SATURDAY
NIGHT. LOW PRESSURE WILL TRACK WELL SOUTHEAST OF LONG ISLAND
SUNDAY NIGHT. A COUPLE OF COLD FRONTS WILL CROSS THE REGION LATE
SUNDAY NIGHT THROUGH TUESDAY MORNING. WEAK HIGH PRESSURE WILL
RETURN FOR MID WEEK...WITH A COLD FRONT PASSING THROUGH LATE WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
LOW PRESSURE WAS RAPIDLY INTENSIFYING ALONG THE NC COAST WITH 3
HOUR PRES FALLS OF 10 MB OFF THE VA COAST.
BASED ON RAPID DEEPENING OF THE LOW WITHOUT AN INTERACTING HIGH
PRESSURE SYSTEM...A COMPACT TIGHT WIND FIELD WILL RAPIDLY DEVELOP
AS THE LOW MOVES NORTHEAST AND OFFSHORE.
USING A COMPROMISE OF THE 12Z ECMWF AND THE 18Z GFS...AND HOURLY
BUFKIT SOUNDINGS...ISSUED A SHORT FUSE WIND ADVISORY FOR THE TWIN
FORKS AND A GALE WARNING FOR THE EASTERN COASTAL WATERS FROM 4 AM
UNTIL 10 AM SATURDAY MORNING...MAINLY FOR SUSTAINED WINDS OF 30-35
KT.
THE NAM CONTINUES TO RUN A DEEPER LOW ON THE NW SIDE OF THE FCST
SOLUTIONS WHILE THE HRRR SHOWS A LESS INTENSE SYSTEM ON THE SE
SIDE OF THE FCST SOLUTIONS.
RAIN CONTINUES TO ADVECT NE AND DEVELOP ACROSS THE REGION. THE
HEAVIEST RAIN WILL OCCUR FROM 06Z TO 12Z AND RAPIDLY TAPER OFF AS
THE LOW ACCELERATES NORTHEAST AND OFFSHORE SATURDAY MORNING.
TEMPERATURES WILL BE WARM ENOUGH FOR PLAIN RAIN EVERYWHERE. THE
ONLY PLACE THAT NEEDS TO BE WATCHED WILL BE ACROSS ORANGE COUNTY
WHERE TEMPERATURES MAY FALL BETWEEN 33-35 DEGREES. THERE IS A LOW
CHC FOR A BRIEF PERIOD OF FREEZING RAIN.
OTHERWISE...EXPECT A PERIOD OF MODERATE RAIN LATE TONIGHT INTO
EARLY SATURDAY. RAINFALL TOTALS ARE EXPECTED TO RANGE FROM A HALF
INCH TO JUST OVER ONE INCH...WITH THE HIGHEST VALUES ACROSS
EASTERN LONG ISLAND AND EASTERN CT. THE LOW MOVES QUICKLY AND RAIN SHOULD
COME TO AN END SATURDAY MORNING. EXPECT A DRY/BRISK AFTERNOON AS
WEST- NORTHWEST WINDS ON THE BACK SIDE OF THE LOW INCREASE TO
15-25 MPH.
&&
.SHORT TERM /TONIGHT THROUGH 6 PM SUNDAY/...
HIGH PRESSURE BUILDS IN SATURDAY NIGHT WITH DRY CONDITIONS. WINDS
WILL GRADUALLY DIMINISH AND WITH MOSTLY CLEAR SKIES...EXPECT LOWS TO
FALL INTO THE 20S AND LOWER 30S. USED A MAV/MET BLEND FOR
TEMPERATURES IN THE SHORT TERM.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
A RETURN TO TEMPS SEVERAL DEGREES BELOW NORMAL FOR THE NEW WEEK.
MODELS IN GENERAL AGREEMENT WITH A POLAR LOW TRACKING THROUGH THE
GREAT LAKES SUNDAY INTO SUNDAY NIGHT...EAST THROUGH NEW ENGLAND ON
MONDAY...AND THEN INTO EASTERN CANADA THROUGH WED. ALTHOUGH THE
POLAR TROUGH AXIS SLIDES EAST BY TUE NIGHT...MEAN CONUS TROUGHING
WILL CONTINUE THROUGH THE WEAK...BECOMING AMPLIFIED LATE IN THE WEEK
AS A NORTHERN STREAM TROUGH DIGS INTO THE NORTHEAST.
AT THE SURFACE...ONE POLAR FRONT MOVES THROUGH THE REGION LATE SUN
NIGHT/EARLY MON AND A SECOND LATE MONDAY NIGHT INTO TUE MORNING.
THIS WILL BRING A MODERATING ARCTIC AIR MASS INTO THE REGION FOR
THE EARLY WEEK...WITH HIGH TEMPS LIKELY NOT GETTING OUT OF THE 20S
MON THRU TUE...WITH LOWS IN THE TEENS MON NIGHT. WITH WNW WINDS OF
15 TO 25 MPH AND GUSTS IN THE 30S LIKELY...WIND CHILLS IN THE
SINGLE DIGITS AND TEENS LIKELY MON AND TUE...WITH POTENTIAL FOR
SUBZERO WIND CHILLS 0 TO 5 BELOW ZERO MON NIGHT. HIGH TEMPS SHOULD
MODERATE SLIGHTLY FOR THE MID TO LATE WEEK IN THE WAKE OF THE
POLAR LOW...BUT LIKELY NOT GET MUCH ABOVE THE UPPER 20S/LOWER 30S
FOR THE REMAINDER OF THE WEEK WITH REGION UNDER INFLUENCE OF
NORTHERN STREAM.
IN TERMS OF PRECIP...NO SIGNALS FOR SIGNIFICANT WEATHER AT THIS
TIME. MODELS IN GOOD AGREEMENT WITH PAC ENERGY OVER CALIFORNIA
TODAY...RACING ACROSS THE SOUTHERN US AND SLIDING AROUND THE POLAR
LOW INTO THE WESTERN ATLANTIC SUNDAY NIGHT. DETERMINISTIC MODELS AND
ENSEMBLE MEANS ARE KEEPING THIS ENERGY LESS PHASED...WITH A
SOUTHERN LOW TRACKING WELL SE OF THE 40/70 BENCHMARK SUN NIGHT.
SBU ENSEMBLE SENSITIVITY SIGNALING SOME ENSEMBLE SPREAD WITH THE
TRACK OF THIS LOW...BUT MAINLY DUE TO STRENGTH DIFFERENCES...NOT
TRACK. THIS OFFSHORE TRACK SHOULD KEEP THE MAIN PRECIP SHIELD WITH
THIS STORM WELL OFFSHORE LATE SUN/SUN NIGHT. IT APPEARS MORE DUE
TO LIFT FROM THE SOUTHERN STREAM SHORTWAVE ENERGY ROUNDING THE
UPPER LOW THAT THE REGION HAS POTENTIAL FOR SOME LIGHT SNOW
SHOWERS LATE SUN/SUN EVE. BETTER CHANCE FOR SNOW SHOWERS LOOKS TO
BE LATE SUN NIGHT THROUGH MON AS THE POLAR FRONT MOVES THROUGH AND
THEN AS POLAR LOW AND ASSOCIATED VORT MOVES INTO THE
REGION...COMBINING WITH RESIDUAL LAKE MOISTURE AND LOW-LEVEL
INSTABILITY. MODELS LOOKS TO BE SIGNALING BETTER CHANCE FOR
STEADIER LIGHT SNOW SUN NIGHT/MON TO THE NORTH OF THE REGION WITH
INVERTED TROUGH/WEAK CLIPPER ORIENTING IN THE PATH OF THE UPPER
LOW. FINALLY...PERHAPS SOME ISOLATED SNOW SHOWERS OR FLURRIES LATE
MON NIGHT/TUE MORNING AS THE POLAR LOW TROUGH AXIS MOVES THROUGH.
THEREAFTER...POTENTIAL FOR LIGHT PRECIP LATE WEEK...BUT LOW
CONFIDENCE ON TIMING WITH MODELS DIVERGING ON THE EVOLUTION OF
DIGGING NORTHERN STREAM ENERGY.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
INTENSIFYING LOW PRESSURE WILL TRACK UP THE COAST THROUGH EARLY
MORNING...THEN MOVE QUICKLY NE OF THE AREA.
NE WINDS 5 TO 10 KT THROUGH AROUND 09Z. SPEEDS INCREASE TO 10-15
KT WITH GUSTS 20-25 KT AFTER 09Z...STRONGEST AT THE COASTAL
TERMINALS. WINDS WILL BACK TO THE NW IN THE MORNING...WITH GUSTS
BRIEFLY SUBSIDING BEFORE RESUMING IN THE AFTERNOON.
FLIGHT CAT WILL LOWER TO MVFR AFTER 08Z...THEN TO IFR IN HEAVIER
RAIN,. RAIN WILL END SAT MORNING...WITH FLIGHT CAT IMPROVING TO
VFR AT MOST TERMINALS DURING THE MORNING AND EARLY AFTERNOON.
.OUTLOOK FOR 06Z SUN THROUGH WED...
.SAT NIGHT-SUNDAY...VFR.
.SUNDAY NIGHT-MON NIGHT...MVFR OR LOWER CONDS AT TIMES IN SNOW
SHOWERS. NW WINDS G25-30KT ON MON.
.TUE...VFR. NW WINDS G25-30KT.
.WED...VFR.
&&
.MARINE...
A GALE WARNING IS IN EFFECT 4 AM - 10 AM SATURDAY FROM MORICHES
INLET EAST TO MONTAUK AND THE EASTERN INLAND BAYS. GUSTS MAY
APPROACH 34 KT ACROSS PARTS OF THE FAR EASTERN SOUND DURING THIS
TIME.
OTHERWISE...A SMALL CRAFT ADVISORY REMAINS IN EFFECT FROM 1 AM
SATURDAY TO 6 AM EST SUNDAY FOR THE REST OF THE COASTAL WATERS.
SOUTH WINDS THIS EVENING WILL GRADUALLY BECOME NORTHEAST...THEN
INCREASE AND BECOME NORTHWEST LATE TONIGHT AND SATURDAY MORNING.
AS LOW PRESSURE MOVES OFF THE MID-ATLANTIC COAST AND PASSES SOUTH
AND EAST OF LONG ISLAND EXPECT WIND GUSTS NEAR 34 KT. SEAS WILL
ALSO INCREASE TO 5 FT LATE TONIGHT...AND EVENTUALLY 7-10 FT DURING
THE DAY SATURDAY. WIND AND SEAS WILL GRADUALLY SUBSIDE LATE
SATURDAY NIGHT.
SUB SCA CONDS EXPECTED SUN INTO SUN EVE WITH A WEAK GRADIENT ACROSS
THE REGION.
OTHERWISE...DEVELOPING SCA CONDITIONS SUN NIGHT IN WAKE OF DEPARTING
OFFSHORE LOW. THEN GALE CONDITIONS POSSIBLE ON ALL WATERS MON
THROUGH TUE WITH STEEP LAPSE RATES AND TIGHT WNW GRADIENT IN WAKE OF
POLAR FRONT. CONDITIONS SHOULD GRADUALLY SUBSIDE TO SCA TUE NIGHT
AND THEN EVENTUALLY SUB SCA FOR MIDWEEK AS HIGH PRESSURE BUILDS
TOWARDS THE WATERS.
&&
.HYDROLOGY...
QPF OF 1/2 TO 1 INCH EXPECTED FRI NIGHT INTO SAT MORNING...WITH
LOCALLY HIGHER AMOUNTS POSSIBLE. THE HIGHEST AMOUNTS WILL BE ACROSS
THE EASTERN PORTIONS OF LONG ISLAND AND CONNECTICUT. P-TYPE SHOULD
BE ALL LIQUID.
NO SIGNIFICANT PRECIPITATION IS EXPECTED SUNDAY THROUGH FRIDAY.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...WIND ADVISORY FROM 4 AM TO 10 AM EST THIS MORNING FOR NYZ079-
081.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR ANZ330-
345.
GALE WARNING FROM 4 AM TO 10 AM EST THIS MORNING FOR ANZ340-
350.
SMALL CRAFT ADVISORY UNTIL 6 AM EST SUNDAY FOR ANZ353-355.
&&
$$
SYNOPSIS...BC/GC/NV
NEAR TERM...BC/GC
SHORT TERM...BC
LONG TERM...NV
AVIATION...DS
MARINE...BC/GC/NV
HYDROLOGY...BC/GC/NV
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
335 AM CST SAT JAN 16 2016
.SHORT TERM...(Today)
ISSUED AT 335 AM CST SAT JAN 16 2016
Mostly cloudy and cool conditions are expected today across central
and southeast Illinois. Forecast highs mainly in the 20s (lower 30s
south of I-70) are several degrees below normal, but nothing like
what the next couple of days will hold. The biggest forecast problem
today is how much clearing can be hoped for. Arctic high pressure
will begin to nudge into the area today, but forecast soundings
suggest a strengthening subsidence inversion just below 850 MB. So,
we`ll have to advect the low clouds out, as they will be unlikely to
mix out. Recent satellite loops show clearing approaching Illinois
from the northwest. However, additional areas of low clouds persist
further upstream into the upper Midwest and northern Plains. With
these trends in mind, expect a partly to mostly cloudy day.
&&
.LONG TERM...(Tonight through Friday)
ISSUED AT 335 AM CST SAT JAN 16 2016
An arctic airmass to usher into central IL tonight and Sunday
bringing some of the coldest air of the season to the region which
will linger into early next work week. A wind chill advisory will
likely be needed for central IL north of I-70 Sunday night into
Monday morning for wind chills of 15-25 below zero.
Strong 504 dm 500 mb low along the Ontario and Manitoba province
line to track to northern Lake Superior by 12Z/6 am Sunday and to
the Ontario/Quebec province line by midnight Sunday night where it
could deepen a bit more. A northern stream short wave tracks se from
the northern plains into central IL Sunday morning. This to bring up
to a half inch of snow to parts of central IL overnight Saturday
night into Sunday morning with just a trace to a tenth inch
southeast of I-70. Lows tonight ragne from around 5F nw of the IL
river to near 20F far southeast IL by Lawrenceville. Wind chills to
lower to 10-14F below zero nw of IL river late tonight into Sunday
morning. Temps not expected to climb much on Sunday with nw winds
increase to 15-25 mph and wind chills lower to 15-20 below zero by
sunset Sunday over northern CWA. Wind chills then lower to 15-25
below zero during Sunday night into Mon morning across areas north
of I-70. Lows Sunday night range from around 5 below northern CWA to
0-5F above in southeast IL.
Arctic high pressure of 1034 mb nosing into MN/IA on Monday keeps
frigid conditions over IL with highest generally 10-15F despite
ample sunshine. NW winds 10-15 mph on Monday still keeps wind chills
below zero Monday afternoon over much of central IL. Still quite cold
Monday night with lows of Zero to plus 7F.
A stronger northern stream short wave forecast to track into IL Tue
night into Wed. This to bring small chances of light snow to western
areas by Tue afternoon and likely bring light snow with 1-2 inches
possible Tue night into Wed. Any mixed precipitation Wed afternoon
appears to stay south of I-64 in far southern IL. Highs Tue elevate
into the lower 20s ne half and mid 20s sw half. Highs Wed of 29-33F.
Extended models have trended further south with next storm system
over the Gulf Coast States and TN river valley Thu/Fri as upper
level ridge builds toward IL late next week. Have just slight
chances of light snow Wed night and Thu and mainly over southern
areas Thu. This to bring milder temperatures for next weekend with
drier conditions prevailing later next week.
&&
.AVIATION...(For the 06Z TAFS through 06Z Saturday night)
ISSUED AT 1149 PM CST FRI JAN 15 2016
A couple of surface troughs rotating through northern Illinois
will keep a mix of MVFR and IFR clouds over our terminal sites
through tomorrow morning. The initial trough will trigger flurries
and patchy freezing drizzle east of a line from BMI to Lincoln
through 1 am. Have included -FZDZSN at CMI until 08z, with -sn at
BMI until 07z. Dry conditions should prevail until just beyond
this TAF period, when a quick shot of light snow will arrive after
06z tomorrow night.
HRRR, RAP and GFS output indicate some clearing may develop from
north to south on Saturday morning, but the NAM soundings are much
more pessimistic with IFR/MVFR clouds through the entire TAF
period. Will lean toward drier solution of some clearing
developing late tomorrow morning or early afternoon.
Wind gusts have generally subsided, except for DEC and CMI, where
gusts to 20kt could linger until 08z. Sustained winds will hover
in the 12-14kt range until 18z, then they should diminish later
Saturday afternoon to 08-11kt.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...BAK
LONG TERM...07
AVIATION...Shimon
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1149 PM CST FRI JAN 15 2016
.UPDATE...
ISSUED AT 900 PM CST FRI JAN 15 2016
Freezing drizzle has preceded the band of light snow showers that
have been progressing across our northern counties. Freezing
drizzle is no longer showing up on radar, as it is progressing
farther away to the east. It may last for another hour or so in
our eastern counties before the snow showers arrive from the west.
Upstream reports from western Illinois were that a dusting of snow
was accumulating on surfaces. So we updated to increase PoPs for
light snow and changed the flurries to snow showers for this
evening. Freezing drizzle was also added across eastern counties,
generally along and north of I-74. The snow showers are steadily
progressing to the east, and should reach the Indiana border
between midnight and 1 am. Slippery conditions will be possible
during that time as air temperatures continue to drop below
freezing. Low temps still look on track, with mid-teens near
Galesburg and mid-20s south of I-70.
Gusty northwest winds to 25 mph will continue as pressure rises
remain in the 3-4 mb/3hr range through at least midnight. Have
increased winds and gusts in the grids for the rest of the night.
Clouds will remain entrenched across IL through Saturday morning,
and possibly into the afternoon. No changes needed there.
Updated forecast info is already available.
&&
.SHORT TERM...(Tonight)
ISSUED AT 228 PM CST FRI JAN 15 2016
20z/2pm surface analysis shows cold front pushing east of the I-57
corridor, as the area of rain ahead of the boundary exits into
Indiana. While temperatures are still in the lower to middle 40s
across the E/SE KILX CWA, readings have dropped into the lower to
middle 30s further west across the remainder of the area.
Temperatures will continue to fall over the next couple of hours,
with readings ranging from the upper 20s in the Illinois River
Valley...to the upper 30s across the far SE around Lawrenceville by
early evening. Latest satellite imagery shows plenty of clouds
upstream across central/eastern Iowa, with the closest appreciable
clearing over western sections of Minnesota/Iowa. HRRR shows this
clear spot shifting southeastward and remaining W/SW of the CWA
tonight. Further north, HRRR is hinting that some breaks in the
overcast will develop across Wisconsin later tonight: however, any
clearing from the north will likely not occur until Saturday
morning. As a result, am going with a cloudy forecast tonight, with
a few flurries possible along/north of I-72 during the evening.
Overnight low temperatures will range from the teens northwest of
the Illinois River to the upper 20s southeast of I-70.
.LONG TERM...(Saturday through Friday)
ISSUED AT 228 PM CST FRI JAN 15 2016
Large high pressure ridge will move into the area and affect the CWA
beginning tomorrow. However, a clipper system will move toward the
area tomorrow evening and then into the CWA late tomorrow night. The
snow will push into the northwest parts of the CWA and then spread
east southeast across the remainder of the CWA Sunday morning. If
any area of the CWA does not get snow, it will be in southeast IL.
Northwest winds will be a tad breezy on Sunday as this clipper
system pushes east and out of the area. Dry weather is then expected
through Mon night with cold high pressure dominating the weather
pattern at the end of the weekend and into the beginning of next
week.
Temps will become very cold this weekend as the cold air associated
with the high pressure pours into the area this weekend. Temps will
drop into the single digits along and northwest of the IL river for
Sat night, with wind chills in the range of -10 to -15, which is
close to wind chill advisory. Temps will get much colder Sun night
into Mon morning, with low temps in the single digits in southeast
IL and below zero over the remainder of the CWA, north of I-70.
Combined with the wind, resulting wind chills Sun night will range
from 15 to 25 degrees below zero over most of the area...which is
wind chill advisory criteria.
Another clipper-type weather system will move across the area Tue
thru Wed and produce another round of light snow in the area. Models
differ on speed/timing of this system but appears that most of the
snow will be on Tue night and Wed. After this system moves through,
ECMWF and GFS agree that any additional systems will get pushed
further south leaving the CWA dry from Wed night through Fri.
However, the Canadian model brings another clipper system through
the area mid week with more snow, which agreed with some older model
runs. Blend of the models gives more chance pops, but prefer better
agreement of the ECMWF and GFS. So for now, will just lower pops to
slight chance for Wed night thru Fri; though thinking is that a dry
forecast is what will be seen in later forecasts.
Temps will start cold with Mon night temps remaining well below
normal. Then temps gradually warm back up but not reaching normal
through end of the week. Extended model guidance does not look that
bad, but kept a degree or two below guidance for now.
&&
.AVIATION...(For the 06Z TAFS through 06Z Saturday night)
ISSUED AT 1149 PM CST FRI JAN 15 2016
A couple of surface troughs rotating through northern Illinois
will keep a mix of MVFR and IFR clouds over our terminal sites
through tomorrow morning. The initial trough will trigger flurries
and patchy freezing drizzle east of a line from BMI to Lincoln
through 1 am. Have included -FZDZSN at CMI until 08z, with -sn at
BMI until 07z. Dry conditions should prevail until just beyond
this TAF period, when a quick shot of light snow will arrive after
06z tomorrow night.
HRRR, RAP and GFS output indicate some clearing may develop from
north to south on Saturday morning, but the NAM soundings are much
more pessimistic with IFR/MVFR clouds through the entire TAF
period. Will lean toward drier solution of some clearing
developing late tomorrow morning or early afternoon.
Wind gusts have generally subsided, except for DEC and CMI, where
gusts to 20kt could linger until 08z. Sustained winds will hover
in the 12-14kt range until 18z, then they should diminish later
Saturday afternoon to 08-11kt.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...Shimon
SHORT TERM...Barnes
LONG TERM...Auten
AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
258 AM EST SAT JAN 16 2016
.UPDATE...
LONG TERM AND AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 627 PM EST FRI JAN 15 2016
A COLD FRONT WILL SWEEP ACROSS CENTRAL INDIANA TONIGHT...PUSHING
COOLER...MORE SEASONABLE AIR INTO CENTRAL INDIANA. CLOUDS ARE
EXPECTED TO LINGER ACROSS CENTRAL INDIANA ON SATURDAY AND SUNDAY
AS YET ANOTHER COLD FRONT PASSES ON LATE SATURDAY NIGHT...ALLOWING
TEMPERATURES TO FALL EVEN COLDER.
DRY BUT COLD WEATHER IS EXPECTED AS WE START THE NEXT WORK WEEK.
&&
.NEAR TERM /OVERNIGHT/...
ISSUED AT 930 PM EST FRI JAN 15 2016
RADAR SHOWS A QUICK MOVING AREA OF SNOW SHOWERS OVER NRN ILLINOIS
POISED TO PUSH INTO NRN INDIANA OVERNIGHT AMID THE BROAD CYCLONIC
FLOW WIN THE WAKE OF THE PASSED COLD FRONT. AS HRRR SHOWS SHOWS
THIS DEVELOPMENT OVERNIGHT AND EXTENSIVE CLOUD COVER
CONTINUES...HAVE TRENDED TOWARD CLOUDY SKIES ALONG WITH SLIGHT
CHANCE FOR A SNOW SHOWER...MAINLY NORTH OF I-70. DUE TO LIMITED
MOISTURE AND POOR ORGANIZATION...ANY ACCUMULATION WILL BE LIMITED.
STRONG COLD AIR ADVECTION IS ONGOING AS TEMPS IN THE MID 20S ARE
PREVALENT UPSTREAM. THUS HAVE TRENDED LOW TEMPS A BIT COOLER
PENDING THE ARRIVAL OF THE COLDER AIR.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY/...
ISSUED AT 225 PM EST FRI JAN 15 2016
FOCUS IS ON SNOW CHANCES THEN COLD SUNDAY.
SATURDAY FEATURES HIGH PRESSURE BEFORE ARCTIC FRONT ARRIVAL. WITH
LOTS OF RESIDUAL MOISTURE IN LOW LEVELS...EXPECT CLOUDY SKIES TO
CONTINUE OR PERHAPS ONLY A FEW BREAKS IN THE CLOUDS AT BEST. THUS
VERY LITTLE WARMING SATURDAY AND CURRENT MAX TEMPS IN LOWER 30S
LOOK GOOD. SATURDAY NIGHT AND SUNDAY...MODELS ARE IN PRETTY GOOD
AGREEMENT WITH ARCTIC FRONT APPROACHING BY DAYBREAK SUNDAY.
CURRENT MIN TEMP FORECASTS OF TEENS TO LOWER 20S MAYBE A BIT COLD
SUNDAY MORNING THOUGH WE ARE IN COLD ADVECTION. SOME LIGHT SNOW
TO ACCOMPANY TROUGH PASSAGE SUNDAY FOLLOWED BY SLOWLY FALLING
TEMPS THEN GRADUAL LATE DAY CLEARING. WITH NO SURFACE WAVE TO
SPEAK OF WITH THIS NEW ARCTIC SURGE...FEEL THE NAM QPF IS A BIT
HIGH FOR SYNOPTICS AND AVAILABLE MOISTURE BUT ALSO THINK GFS IS A
TAD LOW ON QPF. THUS SNOW AMOUNTS A HALF INCH OR LESS NORTH AND
TRACE OR DUSTING SOUTH APPEAR BEST.
SUNDAY NIGHT AND MONDAY...SKIES WILL BE CLEAR UNDER THE INFLUENCE
OF HIGH PRESSURE. WIND FLOWS SHOULD KEEP ANY LAKE EFFECT SNOWS
WELL TO THE NORTH. THOUGH THICKNESSES WILL BE SLIGHTLY LOWER THAN
PREVIOUS ARCTIC PUSH AND THOUGH SKIES WILL BE CLEAR...JUST ENOUGH
WIND AND A RELATIVE ABSENCE OF SNOW COVER THIS TIME SHOULD KEEP
MOST LOCATIONS JUST ABOVE ZERO SUNDAY NIGHT AND MONDAY MORNING.
WIND CHILLS WILL BE NEAR 15 BELOW ZERO MONDAY AND AT THRESHOLD
FOR WIND CHILL ADVISORY BUT COUPLE MORE MODEL RUNS MAY CHANGE
NUMBERS SOME. ADVISORY...IF ISSUED...WOULD NOT COME BEFORE
SATURDAY AFTERNOON AT EARLIEST.
MONDAY WILL BE SUNNY AND DRY WITH TEMPERATURES IN THE TEENS...ALONG
GUIDANCE LINES...APPEAR GOOD AND NOT CHANGED.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 258 AM EST SAT JAN 16 2016
AFTER A COLD START EARLY NEXT WEEK...TEMPERATURES WILL MODERATE
THROUGH THE LONG TERM AS THE COLD UPPER TROUGH AND ARCTIC AIR
PULLS EASTWARD AND OUR UPPER FLOW BECOMES MORE ZONAL.
HIGH PRESSURE WILL MOVE EAST ACROSS OUR REGION TUESDAY FOLLOWED BY
AN UPPER DISTURBANCE WEDNESDAY. WILL GO WITH CHANCE OF SNOW LATE TUESDAY
NIGHT AND WEDNESDAY. AFTER THAT...PRECIPITATION CHANCES ARE MORE
UNCERTAIN AS MODELS MOVE AN AREA OF LOW PRESSURE ACROSS THE DEEP SOUTH
WHILE A WEAK HIGH PRESSURE RIDGE REMAINS ACROSS THE GREAT LAKES.
WILL CONTINUE A SLIGHT CHANCE POPS SOUTHERN AREAS THURSDAY THEN AND GO DRY
ELSEWHERE. THEN DRY ALL AREAS THURSDAY NIGHT ON AS AN UPPER RIDGE BUILDS EAST
ACROSS THE CENTRAL U.S. STAYED CLOSE TO MODEL INITIALIZED TEMPERATURES.
&&
.AVIATION /DISCUSSION FOR THE 160900Z KIND TAF UPDATE/...
ISSUED AT 258 AM EST SAT JAN 16 2016
MINOR TWEAKS WILL BE MADE TO KIND TAF TO BETTER MATCH CURRENT CONDITIONS.
NO OTHER CHANGES ARE NEEDED AT THIS TIME.
PREVIOUS AVIATION DISCUSSION FOLLOWS...
DEPICTION CHARTS INDICATE THE BACK EDGE OF THE WIDESPREAD IFR CEILINGS
IS NEAR THE WESTERN BORDER...SO LINGERING IFR CEILINGS/MVFR VISIBILITY
RESTRICTIONS IN LIGHT FOG/DRIZZLE/FREEZING DRIZZLE...EXPECTED TO END
AROUND 160700Z.
STRENGTHENING LOW LEVEL INVERSION SHOULD HELP KEEP CEILINGS AROUND 015
BEYOND THE MIDDAY HOURS OF SATURDAY.
LINGERING SURFACE WIND GUSTS 20-22 KTS EXPECTED TO DIMINISH OVER THE NEXT
COUPLE OF HOURS AS PRESSURE GRADIENT RELAXES. OTHERWISE...SURFACE WINDS
270-290 DEGREES AT 9-12 KTS THROUGH MIDDAY SATURDAY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...PUMA
NEAR TERM...PUMA
SHORT TERM...TUCEK
LONG TERM...JH
AVIATION...JAS/JH
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1131 PM EST FRI JAN 15 2016
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 627 PM EST FRI JAN 15 2016
A COLD FRONT WILL SWEEP ACROSS CENTRAL INDIANA TONIGHT...PUSHING
COOLER...MORE SEASONABLE AIR INTO CENTRAL INDIANA. CLOUDS ARE
EXPECTED TO LINGER ACROSS CENTRAL INDIANA ON SATURDAY AND SUNDAY
AS YET ANOTHER COLD FRONT PASSES ON LATE SATURDAY NIGHT...ALLOWING
TEMPERATURES TO FALL EVEN COLDER.
DRY BUT COLD WEATHER IS EXPECTED AS WE START THE NEXT WORK WEEK.
&&
.NEAR TERM /OVERNIGHT/...
ISSUED AT 930 PM EST FRI JAN 15 2016
RADAR SHOWS A QUICK MOVING AREA OF SNOW SHOWERS OVER NRN ILLINOIS
POISED TO PUSH INTO NRN INDIANA OVERNIGHT AMID THE BROAD CYCLONIC
FLOW WIN THE WAKE OF THE PASSED COLD FRONT. AS HRRR SHOWS SHOWS
THIS DEVELOPMENT OVERNIGHT AND EXTENSIVE CLOUD COVER
CONTINUES...HAVE TRENDED TOWARD CLOUDY SKIES ALONG WITH SLIGHT
CHANCE FOR A SNOW SHOWER...MAINLY NORTH OF I-70. DUE TO LIMITED
MOISTURE AND POOR ORGANIZATION...ANY ACCUMULATION WILL BE LIMITED.
STRONG COLD AIR ADVECTION IS ONGOING AS TEMPS IN THE MID 20S ARE
PREVALENT UPSTREAM. THUS HAVE TRENDED LOW TEMPS A BIT COOLER
PENDING THE ARRIVAL OF THE COLDER AIR.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY/...
ISSUED AT 225 PM EST FRI JAN 15 2016
FOCUS IS ON SNOW CHANCES THEN COLD SUNDAY.
SATURDAY FEATURES HIGH PRESSURE BEFORE ARCTIC FRONT ARRIVAL. WITH
LOTS OF RESIDUAL MOISTURE IN LOW LEVELS...EXPECT CLOUDY SKIES TO
CONTINUE OR PERHAPS ONLY A FEW BREAKS IN THE CLOUDS AT BEST. THUS
VERY LITTLE WARMING SATURDAY AND CURRENT MAX TEMPS IN LOWER 30S
LOOK GOOD. SATURDAY NIGHT AND SUNDAY...MODELS ARE IN PRETTY GOOD
AGREEMENT WITH ARCTIC FRONT APPROACHING BY DAYBREAK SUNDAY.
CURRENT MIN TEMP FORECASTS OF TEENS TO LOWER 20S MAYBE A BIT COLD
SUNDAY MORNING THOUGH WE ARE IN COLD ADVECTION. SOME LIGHT SNOW
TO ACCOMPANY TROUGH PASSAGE SUNDAY FOLLOWED BY SLOWLY FALLING
TEMPS THEN GRADUAL LATE DAY CLEARING. WITH NO SURFACE WAVE TO
SPEAK OF WITH THIS NEW ARCTIC SURGE...FEEL THE NAM QPF IS A BIT
HIGH FOR SYNOPTICS AND AVAILABLE MOISTURE BUT ALSO THINK GFS IS A
TAD LOW ON QPF. THUS SNOW AMOUNTS A HALF INCH OR LESS NORTH AND
TRACE OR DUSTING SOUTH APPEAR BEST.
SUNDAY NIGHT AND MONDAY...SKIES WILL BE CLEAR UNDER THE INFLUENCE
OF HIGH PRESSURE. WIND FLOWS SHOULD KEEP ANY LAKE EFFECT SNOWS
WELL TO THE NORTH. THOUGH THICKNESSES WILL BE SLIGHTLY LOWER THAN
PREVIOUS ARCTIC PUSH AND THOUGH SKIES WILL BE CLEAR...JUST ENOUGH
WIND AND A RELATIVE ABSENCE OF SNOW COVER THIS TIME SHOULD KEEP
MOST LOCATIONS JUST ABOVE ZERO SUNDAY NIGHT AND MONDAY MORNING.
WIND CHILLS WILL BE NEAR 15 BELOW ZERO MONDAY AND AT THRESHOLD
FOR WIND CHILL ADVISORY BUT COUPLE MORE MODEL RUNS MAY CHANGE
NUMBERS SOME. ADVISORY...IF ISSUED...WOULD NOT COME BEFORE
SATURDAY AFTERNOON AT EARLIEST.
MONDAY WILL BE SUNNY AND DRY WITH TEMPERATURES IN THE TEENS...ALONG
GUIDANCE LINES...APPEAR GOOD AND NOT CHANGED.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
ISSUED AT 242 PM EST FRI JAN 15 2016
TEMPERATURES SHOULD GRADUALLY MODERATE MORE TOWARD CLIMATOLOGICAL
NORMALS OR JUST BELOW DURING THE LONG TERM PERIOD...AS FLOW BECOMES
MORE ZONAL AND THE AREA PULLS OUT OF THE ANTICIPATED EARLY WEEK DEEP
FREEZE.
A COUPLE OF WEAK DISTURBANCES ARE DEPICTED BY MODELS MOVING THROUGH
THE REGION MID TO LATE WEEK. HOWEVER...MOISTURE IS LACKING AND
MODELS HAVE TRENDED A BIT DRIER. IN COLLABORATION WITH
NEIGHBORS...HAVE DROPPED POPS IN MANY PERIODS DOWN TO SLIGHT CHANCE
ONLY.
&&
.AVIATION /DISCUSSION FOR THE 160600Z TAFS/...
ISSUED AT 1131 PM EST FRI JAN 15 2016
DEPICTION CHARTS INDICATE THE BACK EDGE OF THE WIDESPREAD IFR CEILINGS
IS NEAR THE WESTERN BORDER...SO LINGERING IFR CEILINGS/MVFR VISIBILITY
RESTRICTIONS IN LIGHT FOG/DRIZZLE/FREEZING DRIZZLE...EXPECTED TO END
AROUND 160700Z.
STRENGTHENING LOW LEVEL INVERSION SHOULD HELP KEEP CEILINGS AROUND 015
BEYOND THE MIDDAY HOURS OF SATURDAY.
LINGERING SURFACE WIND GUSTS 20-22 KTS EXPECTED TO DIMINISH OVER THE NEXT
COUPLE OF HOURS AS PRESSURE GRADIENT RELAXES. OTHERWISE...SURFACE WINDS
270-290 DEGREES AT 9-12 KTS THROUGH MIDDAY SATURDAY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...PUMA
NEAR TERM...PUMA
SHORT TERM...TUCEK
LONG TERM...NIELD
AVIATION...JAS
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1052 PM CST FRI JAN 15 2016
.UPDATE:
Issued at 842 PM CST Fri Jan 15 2016
Forecast looks pretty much on track. Made some minor tweaks to
clean up cloud trends over central Missouri. Low clouds are
breaking up over Columbia and Jefferson City, but higher clouds
are streaming in from the west...so forecast should still say
partly to mostly cloudy. Not sure how far east the clearing will
get tonight or tomorrow morning. There`s an expansive area of
stratus upstream which stretches up through eastern Iowa into
Wisconsin. Low level RH forecast on the RAP supports little if
any clearing along and east of the Mississippi for the rest of the
night. Since the western edge of the stratus isn`t moving much
over northeast Missouri, I tend to agree.
Carney
&&
.SHORT TERM: (Tonight and Saturday)
Issued at 310 PM CST Fri Jan 15 2016
Cold but tranquil weather will persist over the next 30 hours. The
cold front has passed through the region and into the OH Valley
and CAA is underway. Stratus, northwest winds, and CAA will continue
tonight as high pressure continues to build south/southeastward
from the northern Plains into the MS Valley. Seeing a few flurries
this afternoon and these may persist into early this evening. Weak
high pressure will dominate on Saturday with gradually diminishing
clouds.
Glass
.LONG TERM: (Saturday Night through Next Friday)
Issued at 310 PM CST Fri Jan 15 2016
Little change in the overall scenario for Saturday Night into
Sunday. A deep vortex/trof will dig southeastward out of south
central Canada into the Great Lakes region carving out a longwave
trof which will dominate the eastern 2/3rds of the CONUS Sunday
into Monday. This digging system will send a secondary cold front
into the region late Saturday night into Sunday morning, that will
usher in the coldest air mass we have seen thus far this winter.
Large scale forcing with the upper system and low level
frontogenetic forcing will combine to produce a band of snow
across the northern Plains on Saturday afternoon and this band
will drop south into IA during the evening and northern MO and
northern IL overnight into early Sunday morning. Present
indications are the band of accumulating snow will weaken
significantly on Sunday morning and largely dissipate to flurries
by afternoon as large scale support quickly shifts northeast of
the area. We`re thinking of potential for light accumulations with
up to an inch of dry snow across parts of far northern MO into
west central IL tapering southward to a dusting in the vicinity of
I-70. Otherwise Sunday will feature blustry conditions with gusty
northwest winds and strong CAA. A large surface high will dominate
the area Sunday Night into Monday Night marked by well below
average temperatures.
By Tuesday the overall flow aloft flattens some as the eastern
U.S. upper vortex/trof depart into the Atlantic. This less
amplified and faster flow from Tues-Fri has lead to rather large
model differences the last few days. With today`s 12z model runs
however we are seeing better agreement although there remain some
timing and amplitude differences with waves in the flow. We are
still looking at another snow event somewhere in the Tuesday-
early Wednesday morning time frame associated with low level WAA
on the backside of the retreating high, frontogenesis, and with a
west-northwest flow short wave. The GFS remains faster and
stronger with greater snow amounts. The late week system Wednesday
night into Thursday night is virtually non-existant now with the
GFS and ECMWF forecasting northwest flow and limited moisture.
Only the GEM still has any suggestions, and thus forecast POPS
have decreased.
Glass
&&
.AVIATION: (For the 06z TAFs through 06z Saturday Night)
Issued at 1036 PM CST Fri Jan 15 2016
Surface high pressure ridge over the northern Plains will continue
to build southeastward into our area late tonight and Saturday.
The nwly surface winds will gradually weaken as the surface
pressure gradient relaxes, and become light by Saturday evening.
The MVFR cigs in UIN and the St Louis metro area will clear out
from west to east early Saturday morning just after 12Z Saturday
like they have just cleared out in COU this evening. Low-mid
level VFR clouds will drop southward into UIN Saturday evening
along and just ahead of the next cold front.
Specifics for KSTL: The MVFR cigs will clear out just after 12Z
Saturday morning. The nwly surface wind will gradually weaken
late tonight and Saturday and eventually become light Saturday
evening.
GKS
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
256 AM CST SAT JAN 16 2016
.SHORT TERM...
AS ADVERTISED AN UA SHORTWAVE TROUGH STRETCHED FROM THE PANHANDLES
REGION SW TO ACROSS NERN OLD MEXICO...CONTINUED TO APPROACH THE
REGION EARLY THIS MORNING. AS A RESULT...FLOW ALOFT HAS BACKED
SLIGHTLY TO THE W-SW THUS CAUSING MID-UPPER LEVELS TO GRADUALLY
MOISTEN. AT THE SFC...DEWPOINTS HAVE RISEN INTO THE 20S ON THE
CAPROCK AND 30S OFF THE CAPROCK...WHICH IS SOME 10-20 DEGREES
HIGHER THAN IT WAS THIS TIME YESTERDAY MORNING. A SFC LOW ACROSS THE
FA WAS DRAGGING IN A COLD FRONT THAT HAS CLEARED ALL BUT PORTIONS OF
THE SRN ZONES PER 08Z METARS. WIND SPEEDS HAVE PICKED UP A BIT /8-12
MPH/ AND MAY INCREASE A BIT MORE THROUGHOUT THE MORNING DUE TO
PRESSURE RISES ON THE ORDER OF 4-5 MB/3 HRS... BUT WILL DROP OFF BY
LATE AFTN. WITH UPPER LEVEL DIFFLUENCE SPREADING ACROSS THE REGION
COURTESY OF THE APPROACHING DISTURBANCE...AND COUPLED WITH
FRONTOGENETICAL FORCING HAS PROMOTED A BIT OF BLOSSOMING OF THE
REFLECTIVITY FIELD PARTICULARLY ACROSS THE SERN TX PANHANDLE...NRN
SOUTH PLAINS AND NRN ROLLING PLAINS. PHONE CALLS MADE TO EMERGENCY
PERSONNEL HAVE RESULTED IN REPORTS OF A LIGHT MIST OR NOTHING AT
ALL...WHICH SUGGESTS THAT THE WET-BULBING PROCESS STILL HAS A WAYS
TO GO. WITH TEMPS ABOVE FREEZING THUS FAR...ANYTHING THAT FALLS WILL
LIKELY BE LIQUID FOR NOW...BUT AS SUGGESTED BY MODEL SOLUTIONS...A
TRANSITION TO SNOW OR A RAIN AND SNOW MIX IS STILL ANTICIPATED WITH
TEMPS GRADUALLY FALLING TOWARD DAYBREAK. SNOW ACCUMULATIONS AOA 1
INCH IS STILL PLAUSIBLE ACROSS THE FAR SRN TX PANHANDLE AND NRN
ROLLING PLAINS WITH MUCH LIGHTER AMOUNTS SOUTH AND WEST.
HENCE...WILL CONTINUE TO HOLD OFF ON THE ISSUANCE OF A WINTER
WEATHER ADVISORY...HOWEVER MOTORISTS ARE STILL URGED TO USE CAUTION
AS BRIDGES AND OVERPASS COULD BECOME SLICK DURING THE MORNING HOURS.
THROUGHOUT THIS PROCESS...THE HRRR SUGGESTS THE DEVELOPMENT OF A
STRATUS DECK AND PERHAPS PATCHY FOG AROUND DAYBREAK...COINCIDING
WITH THE LOCATION OF THE PRECIP. BY MID-LATE MORNING...THE PRECIP
WILL BE TRANSITIONING BACK TO LIQUID AS TEMPS RETURN TO ABOVE
FREEZING...WHILST IT ALSO COMMENCES TO PUSH EAST ACROSS THE ROLLING
PLAINS AS THE UA SHORTWAVE TROUGH AND ASSOCIATED UL SUPPORT EXITS
THE REGION TOWARD E TX. CLOUDS WILL BE SLOW TO SCOUR OUT FROM WEST
TO EAST...BUT WILL LIKELY SEE THE SUN BY LATE AFTN/EARLY EVENING
BEFORE SUNSET. TEMPS WILL BE COOLER TODAY /40S/ THANKS TO THE CLOUD
COVER AND COLD FRONT USHERING IN A COOLER AIRMASS. TONIGHT...WEAK
SFC LEE TROUGHING WILL RETURN SFC WINDS TO A SRLY FLOW...WHILST NW
FLOW ALOFT FILTERS IN SOME HIGH-LEVEL CLOUDINESS. THE CLOUD COVER
WILL DISCOURAGE TEMPS FROM CRATERING BUT IT WILL STILL BY ON THE
CHILLY SIDE /UPPER 20S TO LOWER 30S/.
.LONG TERM...
00Z MODEL SUITE HAS CONTINUED THE TREND TOWARD DRIER...IE LESS
PRECIP CHANCE...THROUGH NEXT WEEK. A LOW-AMPLITUDE PROGRESSIVE
UPPER PATTERN TO PREVAIL THROUGH AT LEAST MIDWEEK. THE NEXT TWO
SHORT WAVE TROUGHS LOOK EVEN MORE BENIGN THAN BEFORE WITH ONLY
WEAK FRONTAL PASSAGES TO ACCOMPANY THEM. HAVE KEPT TUESDAY DRY
WITH ITS UPPER TROUGH...AND HAVE NOW REMOVED PRECIP MENTION FROM
MIDWEEK. A MILD ROLLER COASTER RIDE REGARDING TEMPS WITH THE
FRONTAL PASSAGES. SOME AMPLIFICATION OF THE FLOW PROGGED LATE NEXT
WEEK WITH AN UPPER RIDGE MIGRATING TOWARD THE PLAINS TO RESULT IN
MORE QUIET WEATHER LIKELY A WARM-UP HEADING INTO NEXT WEEKEND.
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
29/07
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
1127 PM CST FRI JAN 15 2016
.AVIATION...
MAIN CONCERN IS THE POTENTIAL FOR RAIN/SNOW MIX AT METROPLEX TAF
SITES SATURDAY. MODELS CONTINUE TO SUGGEST THAT PRECIPITATION
WILL REMAIN LIQUID...HOWEVER THE UNCERTAINTY IS THAT IF PRECIP
INTENSITY IS HEAVY ENOUGH IT WILL FORCE THE FREEZING LEVEL AND
LOW LEVEL TEMPERATURES DOWNWARD ENOUGH TO SUPPORT SOME SNOW MIXING
IN WITH THE RAIN AS FAR SOUTH AS THE METROPLEX. THIS POSSIBILITY
LOOKS SMALL...BUT COULD OCCUR IN THE EARLY TO MID AFTERNOON
HOURS. THERE IS HIGH CONFIDENCE THAT SURFACE TEMPERATURES WILL
REMAIN ABOVE FREEZING NO MATTER WHAT HAPPENS...BUT ANY RECENTLY
ARRIVING AIRCRAFT COULD BE COLD ENOUGH FOR ACCUMULATION OF ICE
FROM PRECIPITATION. WILL SHOW JUST A ONE HOUR TEMPO OF -RASN IN
TAF FROM 20-21Z JUST TO HINT AT MIX POSSIBILITY FOR NOW. NO
AIRPORT WEATHER WARNING WILL BE ISSUED...AS THIS CAN WAIT FOR
HIGHER CONFIDENCE BASED ON UPSTREAM TRENDS.
OTHERWISE VFR CONDITIONS WILL PREVAIL THROUGH MID MORNING BUT MID
AND HIGH CLOUDS WILL CONTINUE TO INCREASE OVERNIGHT. LIGHT RAIN
SHOWERS SHOULD DEVELOP AFTER SUNRISE WITHIN THE WARM CONVEYOR BELT
REGION OF THE UPPER LOW WHERE SOME DECENT ISENTROPIC LIFT AND
STEEP LAPSE RATES WILL EXIST. WILL SHOW SOME LIGHT RAIN SHOWERS AT
TAF SITES STARTING AT 13Z BUT AM KEEPING VSBY AND CIGS VFR. AS A
SURFACE LOW MOVES THROUGH THE REGION...WINDS WILL GO FROM AN
EASTERLY DIRECTION TO A NORTHERLY DIRECTION BY MIDDAY. THE
NORTHERLY WINDS WILL INCREASE TO NEAR 15KT...POSSIBLY STRONGER AT
WACO...AND BEGIN TO BRING COLDER AIR SOUTHWARD DURING THE
AFTERNOON. SO WHILE RAIN MAY START EARLY IN THE DAY...THE CONCERN
FOR ANY MIX WOULD BE TOWARD THE TAIL END OF THE PRECIPITATION
EVENT AROUND MID AFTERNOON.
AS WINDS TURN TO THE NORTH IN THE WAKE OF THE SURFACE LOW...THE
LOW LEVELS WILL SATURATE RESULTING IN MVFR CIGS PREVAILING DURING
THE AFTERNOON HOURS AT ALL TAF SITES. CLEARING SHOULD OCCUR FROM
NORTH TO SOUTH AFTER SUNSET. LIGHT NORTH WINDS AND CLEAR SKIES
WILL PREVAIL SATURDAY NIGHT...WHICH MAY RESULT IN SOME LIGHT FOG
OR FROST BY DAYBREAK. GIVEN THE USUAL DIFFICULTY IN ACHIEVING
RADIATION FOG WITH LIGHT NORTHERLY WINDS BEHIND A COLD FRONT WILL
KEEP IT OUT OF EXTENDED DFW TAF.
TR.92
&&
.UPDATE...
HAVE MADE A FEW MINOR TWEAKS TO THE PREVIOUS FORECAST WITH REGARDS
TO THE RAIN/SNOW POTENTIAL ACROSS NORTH TEXAS TOMORROW. IT STILL
APPEARS THAT LOCATIONS ROUGHLY NORTH OF A GRAHAM TO PARIS LINE
HAVE THE HIGHEST CHANCE TO SEE SOME MINOR SNOW ACCUMULATIONS OF
AROUND HALF AN INCH THROUGH THE DAY TOMORROW.
THE LATEST RAP SOUNDINGS INDICATE SATURATED PROFILES THROUGH
-15C WITH SURFACE TEMPERATURES IN THE MID 30S AROUND MIDDAY
TOMORROW FOR OUR EXTREME NORTHWESTERN ZONES. A QUICK BURST OF
MODERATE TO HEAVY PRECIPITATION WOULD CERTAINLY BE CAPABLE OF
YIELDING SOME MINOR ACCUMULATIONS IN THIS AREA IN PARTICULAR. FOR
AREAS SOUTH OF HWY380...IT APPEARS LOW-LEVELS WILL BE TOO WARM FOR
MUCH SNOW TO SURVIVE THE TRIP TO THE SURFACE AND PRECIPITATION
TYPE WILL BE PRIMARILY RAIN WITH A FEW WET FLAKES MIXED IN.
THEREFORE...HAVE LOWERED THE SNOW ACCUMULATION AMOUNTS WITH THIS
UPDATE FOR AREAS ROUGHLY ALONG AND SOUTH OF HWY380.
THE LATEST DATA WILL CONTINUE TO BE ASSESSED AS THE 00Z MODELS
TRICKLE IN.
STALLEY
&&
.PREV DISCUSSION... /ISSUED 331 PM CST FRI JAN 15 2016/
A STRONG SHORTWAVE DISTURBANCE MOVING INTO THE 4 CORNERS AREA OF
THE SOUTHERN ROCKIES WILL MOVE EAST OVER THE HIGH PLAINS TONIGHT...
THEN TX/OK ON SATURDAY. MEANWHILE...HIGH LEVEL CLOUDINESS WILL
INCREASE TONIGHT...THEN MORE LOWER CLOUDINESS ON SATURDAY AS TOP-
DOWN SATURATION OCCURS. A STRONG SURFACE COLD FRONT CURRENTLY
MOVING INTO NORTHEAST CO/NORTHWEST KS/AND NEBRASKA WILL CONTINUE
TO SURGE SOUTHWARD INTO THE RED RIVER VALLEY BY DAYBREAK SATURDAY.
FRONTOGENETICAL FORCING/BANDING INCREASES ALONG THE NORTHERN PART
OF THE SHORTWAVE TRACK FROM THE I-40 CORRIDOR ACROSS CENTRAL
OKLAHOMA INTO THE HIGHWAY 380 CORRIDOR IN NORTH TEXAS BETWEEN
GRAHAM AND GREENVILLE SATURDAY MORNING. CURRENT FORECAST SOUNDING
PROFILES STILL INDICATE A POTENTIAL FOR A LIGHT RAIN/SNOW PROFILE
FOR ESPECIALLY THE MID MORNING TO MID AFTERNOON PERIOD AS THE
SHORTWAVE ALOFT PROGRESSIVELY TRACKS EAST ACROSS THE AREA.
THE STRONGEST FRONTOGENESIS ALOFT SHOULD OCCUR ALONG AND NORTH OF
THE RED RIVER VALLEY FROM GAINESVILLE TO PARIS AND POINTS NORTH.
THESE AREAS COULD SEE THE OCCASIONAL BURST OF SLIGHTLY HEAVIER
RAIN OR POSSIBLE RAIN/SNOW MIX...AS THE DYNAMIC FORCING INCREASES.
THE COMBINATION OF SYSTEM SPEED...THE ELEVATED DRY AIR AND ABOVE
FREEZING TEMPERATURES SHOULD RESULT IN BRIEF ACCUMS OF WET SNOW
FROM A TRACE/DUSTING...TO JUST UNDER INCH ALONG HIGHWAY 82 IN THE
WORSE CASE SCENARIO. SOME MINOR IMPACTS ON TRAVEL COULD OCCUR
ACROSS THE FAR NORTHERN COUNTIES FOR A FEW HOURS...THOUGH ANY WET
SNOW OR SNOW MIXED WITH RAIN WOULD LIKELY KEEP MOST ROADWAYS WET
WITH ACCUMULATIONS OCCURRING MOSTLY ON GRASSY AREAS. NO WINTER
WEATHER ADVISORY WILL BE ISSUED WITH THIS FORECAST PER THE
AFORMENTIONED PARAMETERS DISCUSSED.
IF THE COLD FRONT TIMING SPEEDS UP...OR THE FRONTOGENESIS ALOFT
IS MORE INTENSE THAN EXPECTED...SOME ENHANCED WET-BULB COOLING OF
THE ATMOSPHERIC COLUMN WOULD OCCUR POTENTIALLY INCREASING THE
RAIN/SNOW RATES AND POSSIBLY CAUSING A FEW PROBLEMS BETWEEN 10 AM
AND 3 PM SATURDAY MAINLY NORTH OF DFW. THE IMMEDIATE DFW AREA
SHOULD REMAIN IN GOOD SHAPE IF THE CURRENT PROGRESSIVE FORECAST
TRACK AND TEMPERATURES HOLD. STILL...IT WILL BE A GOOD IDEA TO
STAY ABREAST OF THE LATEST FORECAST THINKING ON SATURDAY MORNING
BEFORE YOU HEAD OUT TO TRAVEL THOSE PARTS OF NORTH TEXAS NORTH OF
I-20. THIS SYSTEM WILL LIFT QUICKLY TO THE EAST OF THE AREA
SATURDAY EVENING WITH RAPID CLEARING FOR A CHILLY NIGHT. ANYWHERE
WHERE RESIDUAL MOISTURE REMAINS ON ROADS NORTH OF I-20 WOULD
LIKELY SEE THE POTENTIAL FOR RE-FREEZING FOR SPOTTY ICY PATCHES.
KEEP THIS IN MIND. WINDS WILL BE BRISK FROM THE NORTH ON SATURDAY
WITH HIGH TEMPERATURES ONLY IN THE 40S FOR MUCH OF THE AREA EXCEPT
PARTS OF CENTRAL TEXAS.
WINDS WILL QUICKLY COME AROUND OUT OF THE SOUTH ON SUNDAY AS
SURFACE CYCLOGENSIS OCCURS ACROSS WEST TEXAS IN ADVANCE OF OUR
NEXT SHORTWAVE. HIGH TEMPERATURES WILL RECOVER INTO THE 50S
AREAWIDE BEFORE THE NEXT COLD FRONT ARRIVES SUNDAY NIGHT INTO
MONDAY MORNING. THIS DISTURBANCE WILL BE MORE MOISTURE-STARVED
HEADING INTO MONDAY THAN THE SYSTEM FOR SATURDAY AND WILL HOLD TO
A DRY FORECAST. HOWEVER...A FEW SPRINKLES OR POSSIBLY FLURRIES
LATE IN THE DAY MONDAY ACROSS THE NORTHEAST HALF OF THE CWA WILL
CERTAINLY BE POSSIBLE. ZONAL FLOW WILL DOMINATE TUESDAY INTO
WEDNESDAY WITH A WARM UP TO BETWEEN 55 AND 65 DEGREES ONCE
AGAIN...AS SURFACE WINDS RETURN FROM THE SOUTH AND BECOME GUSTY
AT TIMES.
A SHORTWAVE WILL MOVE QUICKLY EAST ACROSS THE CENTRAL U.S. TUESDAY
NIGHT AND WEDNESDAY...BUT WILL MAINLY ACT AS A SUPPORT MECHANISM
FOR YET ANOTHER COLD FRONTAL PASSAGE ACROSS NORTH AND CENTRAL TX.
LOW CHANCES FOR FEW LIGHT SHOWERS OR EMBEDDED THUNDER WILL EXIST
EAST OF I-35... BUT NOTHING OF SIGNIFICANCE. A STRONGER SHORTWAVE
DISTURBANCE ARRIVES THURSDAY INTO THURSDAY NIGHT...AS THE LONGWAVE
FLOW ACROSS THE CENTRAL U.S. BECOMES MORE AMPLIFIED CYCLONICALLY.
ONCE AGAIN TEMPERATURES APPEAR TO REMAIN WARM ENOUGH FOR JUST A
CHANCE FOR RAIN WITH ISOLATED THUNDER ONCE AGAIN. RAINFALL AMOUNTS
WILL CONTINUE TO BE LIGHT AS RICH MOISTURE REMAINS CONTAINED SOUTH
AND EAST OF THE FORECAST AREA. HIGHS WILL BE MOSTLY IN THE 50S.
05/
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 41 45 33 53 32 / 5 40 5 0 10
WACO, TX 40 49 32 54 36 / 0 20 5 0 5
PARIS, TX 37 44 31 51 31 / 5 50 10 0 10
DENTON, TX 37 43 29 52 30 / 10 50 0 0 10
MCKINNEY, TX 37 44 31 52 31 / 5 50 5 0 10
DALLAS, TX 41 45 32 52 33 / 5 40 5 0 5
TERRELL, TX 39 46 31 52 33 / 5 50 5 0 5
CORSICANA, TX 41 50 34 54 37 / 0 30 5 0 5
TEMPLE, TX 41 52 33 55 36 / 0 20 0 0 5
MINERAL WELLS, TX 39 45 30 56 31 / 5 30 0 0 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CARIBOU ME
935 AM EST SAT JAN 16 2016
.SYNOPSIS...
LOW PRESSURE FROM THE SOUTHWEST WILL TRACK SOUTH OF THE AREA THIS
AFTERNOON AND THEN MOVE EAST TOWARD THE OPEN ATLANTIC TONIGHT.
WEAK HIGH PRESSURE BUILDS BACK TOWARD THE AREA SUNDAY. UPPER LEVEL
LOW PRESSURE WITH WEAK SURFACE LOW PRESSURE WILL APPROACH DOWNEAST
MAINE SUNDAY NIGHT AND CROSS THE REGION ON MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
930 AM UPDATE...DECIDED TO ADD AREAS OF FREEZING DRIZZLE INTO THE
INTERIOR DOWNEAST AND UP INTO CENTRAL AREAS BASED ON THE LATEST
LAPS SOUNDINGS. THEY SHOW SOME DRY AIR RESIDING ABOVE 800MBS PLUS
REPORTS COMING IN VIA SOCIAL MEDIA AND PHONES OF SOME LIGHT
FREEZING PRECIP. MOISTURE IS WORKING ITS WAY IN AND FORECAST FROM
THE LATEST HRRR 3KM AND WRF SHOWING PROFILE MOISTENING AND COOLING
ALLOWING FOR ANY FREEZING PRECIP TO GO OVER TO SNOW.
AS WELL STATED BY THE MIDNIGHT CREW, MUCH OF THE GUIDANCE IS
WARMING THINGS UP TOO QUICKLY ALONG THE COAST. THE COASTAL FRONT
REMAINS OFF THE COAST PER THE 12Z SURFACE ANALYSIS W/AN
INTENSIFYING 979MB LOW SE OF NANTUCKET MOVING NE. GIVEN THE LATEST
PROJECTED TRACK OF THE LOW, THE WARMER AIR COULD REMAIN RIGHT OFF
THE COAST W/FREEZING PRECIP FOR THE COAST GOING TO SNOW INSTEAD OF
A PERIOD OF RAIN. WILL CONTINUE TO MONITOR THIS THROUGH THE DAY.
HEADLINES REMAIN IN PLACE AS IS FOR NOW. WILL ADD THE MENTION OF
THE FREEZING DRIZZLE FOR THE CENTRAL AREAS IN THE STATEMENT THIS
MORNING.
PREVIOUS DISCUSSION...PRIMARY LOW PRESSURE IS CURRENTLY
POSITIONED OVER EASTERN LAKE HURON, WITH THE SECONDARY HAVING
MOVED OFF THE DELMARVA COAST, WITH A TROUGH STRETCHED BETWEEN
THEM. THE ECMWF SEEMS TO HAVE THE BEST HANDLE ON THE SITUATION
ATTM, THOUGH THE GFS IS DOING REASONABLY WELL. BOTH LOWS WILL
SLOWLY PUSH NORTHEASTWARD TODAY, WITH THE PRIMARY GRADUALLY GIVING
WAY TO THE SECONDARY. THE LATEST MODEL TRENDS HAVE BEEN TO KEEP
THE SECONDARY FURTHER OFF SHORE. THIS DOES A FEW THINGS...(1)
LIMITS THE AMOUNT OF MOISTURE/QPF ACROSS OUR AREA, ESPECIALLY IN
THE NORTH (2) KEEPS THE BEST FORCING OFF SHORE (3) AND LIMITS THE
AMOUNT OF WARM AIR THAT WILL SPREAD NORTHWARD AHEAD OF THE PRIMARY
LOW. AS A RESULT, EXPECT THE SNOW LINE WILL REMAIN SOUTH OF
BANGOR, WITH A MIX OF SLEET/SNOW/FREEZING RAIN LIKELY ACROSS
MAINLY COASTAL HANCOCK AND WASHINGTON COUNTIES LATE THIS MORNING
AND EARLY AFTERNOON. ANY PERIODS OF JUST PLAIN RAIN, IF THEY OCCUR
AT ALL, WILL BE VERY BRIEF AND LIMITED TO THE IMMEDIATE COAST.
ONCE THE SECONDARY LOW MOVES TO OUR EAST EARLY THIS AFTERNOON,
COLDER AIR WILL QUICKLY RUSH IN BEHIND IT, RAPIDLY CHANGING ANY
MIXED PRECIP TO ALL SNOW. ICE ACCUMULATION IS STILL EXPECTED TO BE
AROUND A TENTH OF AN INCH AT MOST, BUT SNOWFALL AMOUNTS HAVE BEEN
INCREASED, ESPECIALLY ALONG THE IMMEDIATE COAST. WIDESPREAD 4-8
INCHES OF SNOW IS EXPECTED SOUTH OF A HOULTON TO BILLY-JACK DEPOT
LINE. NORTH OF THIS LINE, HAVE LOWERED AMOUNTS A BIT WITH 2-4
INCHES TO OCCUR. THE STEADIEST PRECIPITATION WILL OCCUR ROUGHLY 1
PM TO 6 PM, THEN GRADUALLY TRANSITION TO SHOWERS FROM SOUTH TO
NORTH AS THE SECONDARY LOW PULLS AWAY AND THE SURFACE TROUGH
CROSSES THE STATE.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
SUN LOOKS TO BE DRIER THAN IT DID YSTDY ATTM...WITH ALMOST ALL
MODELS NOW MUCH MORE PROGRESSIVE WITH MOVING THE E-W SFC TROF WELL
NE OF THE REGION BY AFTN. ANY REMAINING SN SHWRS WILL BE EXITING
THE ST JOHN VLY AREA BY EARLY SUN MORN...WITH SKIES PERHAPS
BECOMING PTLY SUNNY BY AFTN EVEN ACROSS THE N. HI TEMPS LOOK TO BE
NEAR SEASONAL NORMS.
AFT MCLR SKIES SUN EVE...CLDS INCREASE FROM THE W AS UPPER LVL LOW
PRES FROM CNTRL CAN APCHS. WEAK SFC LOW PRES AHEAD OF THIS FEATURE
WILL EXIT THE MID MAINE COAST WITH AN E-W TROF AXIS ON MON...SUGGESTING
THE POSSIBILITY OF NORLUN TROF NARROW BANDED SNFL SOMEWHERE ALG
THE MAINE COAST...BUT IT`S TO EARLY TO SAY EXACTLY WHERE. FOR THIS
REASON WE LIMIT MAX POPS TO THE LIKELY CATEGORY ALG THE COAST ON
MON UNTIL WE GET CLOSER TO THE EVENT AND GET MORE CERTAINTY AS TO
WHAT PTN OF ME COAST WILL BE GREATEST IMPACTED WITH THIS FEATURE.
WITH DEEP LOW TO MID LVL COLD ADVCN INCREASING ACROSS THE REGION N
OF DOWNEAST AREAS ON MON AS THE UPPER LOW CROSSES THE REGION...PRECIP
NWRD OF THE COAST WILL BE MAINLY JUST SCT SN SHWRS AS SFC WINDS
BACK FROM THE NNE TO NW...KEEPING ANY LLVL ATLC MOISTURE IN THE
VCNTY OF THE NORLUN TROF. HI TEMPS MON WILL BE AOB NORMAL WITH
LLVL COLD ADVCN AFT RELATIVELY MILD OVRNGT LOWS SUN NGT DUE TO
INCREASING CLD CVR. MON NGT WILL BE MSLY CLDY WITH FLURRIES AND
SCT SN SHWRS MSLY ACROSS THE N HLF OF THE FA AS WEAK LLVL WARM
OCCLUSION PIVOTS SWRD TOWARD THE REGION FROM ERN QB.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
TEMPS LOOK TO BE A LITTLE MILDER BY LATE TUE FOLLOWING THE PASSAGE
OF A WEAK WARM OCCLUSION FROM NW TO SE ACROSS THE REGION WITH
CLDNSS AND SCT SN SHWRS SPCLY ACROSS THE NW. GUSTY NW WINDS TUE
WILL MASK ANY IMPROVEMENT IN HI TEMPS TUE. WINDS CONT INTO THE NGT
TUE NGT AS SOME CLRG IS XPCTD BY LATE TUE NGT. WED LOOKS TO BE
CONTD BRISK AND SEASONABLY COLD UNDER PTLY TO MSLY SUNNY SKIES.
AFT SOME INCREASE IN CLDNSS WED NGT...THU AND FRI LOOK TO BE
UNSETTLED WITH PERIODIC CLDNSS AND OCNL LGT SN SHWRS DUE THE
PASSAGE OD SEVERAL WEAK/WVS TRACKING EWRD OVR THE REGION FROM
CNTRL CAN/QB. THERE WILL BE LESS THAN THE NORMAL DIURNAL SPREAD
BETWEEN DYTM HI TEMPS AND NGT TM LOWS THU AND FRI DUE TO THIS CLD
CVR...WITH SEASONAL DAY TM HI TEMPS AND SOMEWHAT MILDER OVRNGT
LOWS.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
NEAR TERM: MVFR CONDITIONS ARE EXPECTED TO PREVAIL AT ALL
TERMINALS THIS MORNING, BUT THEY WILL DROP TO IFR DURING THE
AFTERNOON AS SNOW SPREADS ACROSS THE REGION. KBGR AND KBHB WILL
SEE THE HEAVIEST SNOW, WITH FREEZING RAIN AND SLEET LIKELY TO MIX
IN AT KBHB DURING THE AFTERNOON. PRECIPITATION WILL COME TO AN END
AT THE SOUTHERN TERMINALS AFTER 06Z, WITH CEILINGS LIFTING TO
MVFR. HOWEVER, SNOW SHOWERS AND IFR CONDITIONS WILL CONTINUE
THROUGH 12Z SUN AT THE NORTHERN SITES.
SHORT TO LONG TERM: MSLY MVFR CLGS N AND VFR CLGS DOWNEAST SITES
THRU TUE...WITH IFR CLGS/VSBYS POSSIBLE MON WITH A PD OF SNFL.
THEN ALL SITES SHOULD BE VFR WED.
&&
.MARINE...
NEAR TERM: A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR TODAY.
STRENGTHENING LOW PRESSURE WILL PASS TO THE SOUTH OF THE WATERS,
RESULTING IN INCREASING WINDS AND SEAS. A FEW GUSTS TO AROUND 35 KT
WILL BE POSSIBLE THIS AFTERNOON, BUT EXPECT CONDITIONS WILL RAPIDLY
IMPROVE THROUGH THE EVENING HOURS AS THE LOW PULLS INTO THE
MARITIMES.
SHORT TO LONG TERM: BELOW TO MARGINAL SCA CONDITIONS ARE MSLY
XPCTD...WITH A PD OF STRONG SCA CONDITIONS XPCTD MON NGT INTO
WED...WITH POTENTIAL GALE FORCE GUSTS POSSIBLE AT TMS. KEPT CLOSE
TO WW3 WV GUIDANCE FOR FCST WV HTS AND CAPPED MAX WIN GUSTS FOR
NOW TO LESS THAN 32 KT...BUT MAX WIND GUSTS MAY BE RAISED IF THE
POTENTIAL OF GALE FORCE WINDS INCREASE WITH FUTURE FCST UPDATES.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY UNTIL 1 AM EST SUNDAY FOR MEZ005-006-
010-011-015>017-029>032.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR
ANZ050>052.
&&
$$
NEAR TERM...HEWITT
AREA FORECAST DISCUSSION
NWS Tulsa OK
721 AM CST SAT JAN 16 2016
.DISCUSSION...
A west to east oriented band of precip is showing up nicely on
radar mosaic this morning across southern OK...forced by
frontogenesis around 700mb. The band is more intense on the
western flank...due to a more optimal combination of
frontogenetic and QG forcing with the approaching wave. This
better forcing will track from southwest OK down into northeast
TX today as the band pivots in a more WSW-ENE orientation and
slides south and east with time. Thus...the eastern flank of the
precip band will likely be of lighter intensity compared to points
west. Surface temperatures remain above freezing beneath the
band...though wet-bulbing will allow for some snow to reach the
surface if the precip falls heavy enough...especially in the
higher terrain. The ridge tops indeed stand the best chance of
seeing any accumulation. Will maintain less than 1 inch amounts
mainly in the higher terrain of SE OK...with the latest RAP QPF
showing .1" amounts at most from this event. Will hold off on any
headlines for now...with impacts to roads still not looking likely
with the marginal surface temps. Will continue to monitor.
Lacy
&&
.PREV DISCUSSION... /ISSUED 541 AM CST SAT JAN 16 2016/
AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
Area of precipitation continues to expand across southwestern and
south central Oklahoma and expect this to continue spreading into
southeastern Oklahoma this morning. Temperature profiles support a
rain and snow mixture at MLC. Cigs at that location should lower to
4-6k feet and visibility may reach MVFR category if precipitation is
heavy enough. VFR cigs with extensive mid/high level clouds other
TAF sites with skies clearing from west to east late this afternoon
and evening.
PREV DISCUSSION... /ISSUED 356 AM CST SAT JAN 16 2016/
DISCUSSION...
Radar trends over the past hour or two show a band of enhanced
reflectivity setting up just south of I40 in western Ok with light
snow now being reported at Chickasha. Over the next few hours
this will expand into parts of southeast OK...HRRR remains fairly
consistent with main precip band this morning focusing south of a
McAlester to Poteau line. First period pops will lean heavily on
this and radar trends at issuance time.
Temps profiles remain quite marginal for accumulating snow outside
of heaviest precip band...where the column should be cooled enough
due to wet-bulb effects for change to all snow. Would also expect
snow to be dominant precip type much of the day in the higher
elevations of southeast OK. Still possible that a very narrow
corridor could experience a period of moderate snowfall which
could accumulate quickly on grassy/elevated surfaces...perhaps an
inch or so...but right now this looks to be a low impact event and
will hold off on any advisory.
Wave responsible for the rain/snow will move out this afternoon
with a period of clearing skies through early sunday. Strong push
of colder air will arrive Sunday afternoon and evening...perhaps
accompanied by flurries or very light snow. Slightly better
chance of accumulating snow across northwest AR Sunday night as
some weak shortwave energy present. Much colder temps by Monday
morning with wind chills near or even below zero in some areas
near the KS border.
Still a great deal of uncertainty in next weeks forecast as the
pattern remains somewhat unsettled. Potential mid week systems
continue to be handled poorly by mid range models. Overall winter
weather threat looks limited at this time as temps quickly
moderate after Monday.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 43 27 37 12 / 10 0 10 10
FSM 46 26 48 25 / 10 0 10 20
MLC 43 25 48 20 / 60 0 10 10
BVO 41 21 32 9 / 10 0 10 10
FYV 42 21 40 13 / 10 0 10 20
BYV 40 24 41 11 / 0 0 10 20
MKO 43 26 42 16 / 10 0 10 10
MIO 40 22 33 8 / 0 0 10 10
F10 42 27 44 16 / 20 0 10 10
HHW 44 27 52 26 / 70 10 10 10
&&
.TSA Watches/Warnings/Advisories...
OK...NONE.
AR...NONE.
&&
$$
SHORT TERM...30
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
521 AM CST SAT JAN 16 2016
.AVIATION...
-RA INTERMITTENTLY OCCURRING AT KCDS EARLY THIS MORNING AND COULD
CHANGE OVER TO -SN OR -RASN IF TEMPERATURES FALL TO/SLIGHTLY BELOW
FREEZING LATER THIS MORNING. LATEST RADAR ANALYSIS SHOWED SOME
LIGHT ECHOES HAVE DEVELOPED SOUTH OF KPVW. FURTHER DEVELOPMENT IS
POSSIBLE SO HAVE INSERTED A -RASN THERE GIVEN TEMPERATURES ARE
ONLY 1 DEGREE AWAY FROM FREEZING. CONFIDENCE OF PRECIPITATION
NEARING KLBB IS LOW BUT NOT OUT OF THE QUESTION...HOWEVER WILL
ELECT NOT TO INSERT A MENTION AT THIS TIME. WILL OF COURSE AMEND
AS NECESSARY. VFR DECKS ARE EXPECTED TO DETERIORATE TO IFR
CRITERIA LATER THIS MORNING BUT IMPROVE TO VFR BY THE AFTN.
CONCURRENTLY...PRECIPITATION WILL BE EXITING KCDS. SLIGHTLY BREEZY
NORTH TO NORTHEAST WINDS WILL VEER TO THE SOUTHWEST BY LATE
AFTN/EARLY EVENING.
&&
.PREV DISCUSSION... /ISSUED 256 AM CST SAT JAN 16 2016/
SHORT TERM...
AS ADVERTISED AN UA SHORTWAVE TROUGH STRETCHED FROM THE PANHANDLES
REGION SW TO ACROSS NERN OLD MEXICO...CONTINUED TO APPROACH THE
REGION EARLY THIS MORNING. AS A RESULT...FLOW ALOFT HAS BACKED
SLIGHTLY TO THE W-SW THUS CAUSING MID-UPPER LEVELS TO GRADUALLY
MOISTEN. AT THE SFC...DEWPOINTS HAVE RISEN INTO THE 20S ON THE
CAPROCK AND 30S OFF THE CAPROCK...WHICH IS SOME 10-20 DEGREES
HIGHER THAN IT WAS THIS TIME YESTERDAY MORNING. A SFC LOW ACROSS THE
FA WAS DRAGGING IN A COLD FRONT THAT HAS CLEARED ALL BUT PORTIONS OF
THE SRN ZONES PER 08Z METARS. WIND SPEEDS HAVE PICKED UP A BIT /8-12
MPH/ AND MAY INCREASE A BIT MORE THROUGHOUT THE MORNING DUE TO
PRESSURE RISES ON THE ORDER OF 4-5 MB/3 HRS... BUT WILL DROP OFF BY
LATE AFTN. WITH UPPER LEVEL DIFFLUENCE SPREADING ACROSS THE REGION
COURTESY OF THE APPROACHING DISTURBANCE...AND COUPLED WITH
FRONTOGENETICAL FORCING HAS PROMOTED A BIT OF BLOSSOMING OF THE
REFLECTIVITY FIELD PARTICULARLY ACROSS THE SERN TX PANHANDLE...NRN
SOUTH PLAINS AND NRN ROLLING PLAINS. PHONE CALLS MADE TO EMERGENCY
PERSONNEL HAVE RESULTED IN REPORTS OF A LIGHT MIST OR NOTHING AT
ALL...WHICH SUGGESTS THAT THE WET-BULBING PROCESS STILL HAS A WAYS
TO GO. WITH TEMPS ABOVE FREEZING THUS FAR...ANYTHING THAT FALLS WILL
LIKELY BE LIQUID FOR NOW...BUT AS SUGGESTED BY MODEL SOLUTIONS...A
TRANSITION TO SNOW OR A RAIN AND SNOW MIX IS STILL ANTICIPATED WITH
TEMPS GRADUALLY FALLING TOWARD DAYBREAK. SNOW ACCUMULATIONS AOA 1
INCH IS STILL PLAUSIBLE ACROSS THE FAR SRN TX PANHANDLE AND NRN
ROLLING PLAINS WITH MUCH LIGHTER AMOUNTS SOUTH AND WEST.
HENCE...WILL CONTINUE TO HOLD OFF ON THE ISSUANCE OF A WINTER
WEATHER ADVISORY...HOWEVER MOTORISTS ARE STILL URGED TO USE CAUTION
AS BRIDGES AND OVERPASS COULD BECOME SLICK DURING THE MORNING HOURS.
THROUGHOUT THIS PROCESS...THE HRRR SUGGESTS THE DEVELOPMENT OF A
STRATUS DECK AND PERHAPS PATCHY FOG AROUND DAYBREAK...COINCIDING
WITH THE LOCATION OF THE PRECIP. BY MID-LATE MORNING...THE PRECIP
WILL BE TRANSITIONING BACK TO LIQUID AS TEMPS RETURN TO ABOVE
FREEZING...WHILST IT ALSO COMMENCES TO PUSH EAST ACROSS THE ROLLING
PLAINS AS THE UA SHORTWAVE TROUGH AND ASSOCIATED UL SUPPORT EXITS
THE REGION TOWARD E TX. CLOUDS WILL BE SLOW TO SCOUR OUT FROM WEST
TO EAST...BUT WILL LIKELY SEE THE SUN BY LATE AFTN/EARLY EVENING
BEFORE SUNSET. TEMPS WILL BE COOLER TODAY /40S/ THANKS TO THE CLOUD
COVER AND COLD FRONT USHERING IN A COOLER AIRMASS. TONIGHT...WEAK
SFC LEE TROUGHING WILL RETURN SFC WINDS TO A SRLY FLOW...WHILST NW
FLOW ALOFT FILTERS IN SOME HIGH-LEVEL CLOUDINESS. THE CLOUD COVER
WILL DISCOURAGE TEMPS FROM CRATERING BUT IT WILL STILL BY ON THE
CHILLY SIDE /UPPER 20S TO LOWER 30S/.
LONG TERM...
00Z MODEL SUITE HAS CONTINUED THE TREND TOWARD DRIER...IE LESS
PRECIP CHANCE...THROUGH NEXT WEEK. A LOW-AMPLITUDE PROGRESSIVE
UPPER PATTERN TO PREVAIL THROUGH AT LEAST MIDWEEK. THE NEXT TWO
SHORT WAVE TROUGHS LOOK EVEN MORE BENIGN THAN BEFORE WITH ONLY
WEAK FRONTAL PASSAGES TO ACCOMPANY THEM. HAVE KEPT TUESDAY DRY
WITH ITS UPPER TROUGH...AND HAVE NOW REMOVED PRECIP MENTION FROM
MIDWEEK. A MILD ROLLER COASTER RIDE REGARDING TEMPS WITH THE
FRONTAL PASSAGES. SOME AMPLIFICATION OF THE FLOW PROGGED LATE NEXT
WEEK WITH AN UPPER RIDGE MIGRATING TOWARD THE PLAINS TO RESULT IN
MORE QUIET WEATHER LIKELY A WARM-UP HEADING INTO NEXT WEEKEND.
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
29
FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION
VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS RENO NV
244 PM PST SAT JAN 16 2016
.SYNOPSIS...
THE NEXT IN A SERIES OF STORM SYSTEMS TO IMPACT THE SIERRA AND
WESTERN NEVADA MOVES INTO THE REGION LATE SUNDAY AND MONDAY,
BRINGING HEAVY WET SNOW TO THE HIGHER ELEVATIONS WITH RAIN FOR
LOWER ELEVATIONS. THE ACTIVE PATTERN CONTINUES INTO THE MIDDLE OF
NEXT WEEK, AND POSSIBLY INTO EARLY NEXT WEEKEND.
&&
.SHORT TERM...
THE SHORT WAVE THAT BROUGHT LIGHT SNOW AND RAIN TO PARTS OF THE
FORECAST AREA LAST NIGHT AND EARLY THIS MORNING HAS PUSHED EAST.
THE FORECAST AREA WILL BE IN A BRIEF PERIOD OF SHORT WAVE RIDGING
TONIGHT INTO EARLY SUNDAY BEFORE THE NEXT WAVE PUSHES INTO
NORTHERN CALIFORNIA LATE SUNDAY AFTERNOON AND EVENING...THEN
ACROSS WESTERN NEVADA BY LATE MONDAY AFTERNOON.
GUSTY WINDS THIS EVENING SHOULD DROP OFF DURING THE OVERNIGHT
HOURS. A LAKE WIND ADVISORY REMAINS IN EFFECT FOR LAKE TAHOE EARLY
THIS EVENING. LOCALIZED WIND GUSTS OVER 30 MPH ARE POSSIBLE ON
PYRAMID LAKE LATE THIS AFTERNOON...BUT THESE SHOULD DROP BY
SUNSET. WITH DECREASING WINDS AND A PERIOD OF PARTLY CLOUDY SKIES
TONIGHT...SOME VALLEYS COULD SEE PATCHY FOG WHERE SNOW REMAINS.
TEMPERATURES IN THE COLDER SIERRA VALLEYS WILL DROP BELOW FREEZING
ALLOWING FREEZING FOG TO FORM WHICH COULD CREATE SLICK SPOTS ON
ROADS NEAR FOGGY AREAS BY SUNDAY MORNING.
WIND GUSTS WILL INCREASE AGAIN SUNDAY AHEAD OF THE NEXT
SYSTEM...CLOSE TO WHAT OCCURRED TODAY. GUSTS UP TO 45 MPH ARE
LIKELY EAST OF THE SIERRA WITH LESS IN THE SIERRA VALLEYS. WIND
PRONE AREAS EAST OF THE SIERRA MAY GUSTS TO NEAR 55 MPH AT TIMES.
WINDS WILL ALSO INCREASE AGAIN ON PYRAMID LAKE FOR SUNDAY FROM THE
SOUTH AND SOUTHEAST AND WE MAY NEED TO ISSUE A LAKE WIND ADVISORY
THERE FOR THE DAY TIME HOURS SUNDAY...BUT WE WILL LET SUBSEQUENT
SHIFTS TAKE A LOOK AT THIS SITUATION. THE INCREASED WINDS WILL
ALSO INCREASE MIXING AND ALLOW HIGH TEMPERATURES SUNDAY TO CLIMB
ABOVE 50 IN MUCH OF WESTERN NEVADA AND THE 40S IN THE SIERRA
VALLEYS.
THE NEXT STORM SYSTEM APPROACHES NORTHEAST CALIFORNIA LATE SUNDAY
AFTERNOON THEN SPREADS INTO THE TAHOE BASIN AND FAR NORTHWEST
NEVADA SUNDAY EVENING. PRECIPITATION SHOULD REACH MONO COUNTY BY
LATE SUNDAY EVENING. SPILL OVER INTO WESTERN NEVADA IS LIKELY EARLY
MONDAY MORNING. SNOW LEVELS ARE GOING TO VERY TRICKY WITH THIS
ONE. THE WARM NATURE OF THE AIR AHEAD OF THIS SYSTEM WILL CAUSE
SNOW LEVELS TO START QUITE HIGH...FROM 7500 TO 8000 FEET IN MONO
COUNTY DOWN TO 5500 TO 6000 FEET IN FAR NORTHEAST CALIFORNIA AND
NORTHWEST NEVADA. NEAR ISOTHERMAL PROFILES IN THE LOWEST LEVELS OF
THE FORECAST SOUNDINGS THROUGH SUNDAY EVENING ALSO SUPPORT HIGHLY
VARIABLE SNOW LEVELS DEPENDING ON PRECIPITATION INTENSITY. SNOW
LEVELS SHOULD FALL THROUGH THE EVENT...BUT MAY FALL TOO SLOWLY TO
PRODUCE ANYTHING OTHER THAN RAIN BELOW 5500 FEET. ALSO...THE
LATEST MODEL FORECASTS ARE SHOWING LESS MOISTURE OVERALL FOR OUR
PORTION OF THE SIERRA AND NORTHEAST CALIFORNIA AND A TRAJECTORY
THAT WOULD FAVOR HEAVIER RAIN INTO FAR NORTHERN CALIFORNIA.
WITH ALL THIS IN MIND WE HAVE DECREASED QPF A BIT IN THE FORECAST
WHICH LEADS TO LOWER SNOW TOTALS. THE HEAVIEST SNOW IN THE SIERRA
SHOULD FALL BETWEEN MIDNIGHT AND 6 AM MONDAY AT TAHOE AND ABOUT 4
AM TO 10 AM FOR MONO COUNTY. THE BEST MOISTURE IS MOVING INTO THE
TAHOE BASIN SO WE HAVE ISSUED A WINTER WEATHER ADVISORY THERE.
INTO WESTERN NEVADA THERE WILL BE SOME ACCUMULATIONS ABOVE 5500
FEET...BUT THESE WILL BE LIMITED DUE TO DECREASE MOISTURE
AVAILABILITY AND THE TIMING OF THE SYSTEM.
THE SYSTEM MOVES EAST MONDAY AFTERNOON AND EVENING LEAVING THE
FORECAST ARE IN A LULL BEFORE THE NEXT SYSTEM APPROACHES THE
REGION TUESDAY AND TUESDAY NIGHT. XX
.LONG TERM...TUESDAY THROUGH SATURDAY...
AN ACTIVE WEATHER PATTERN LOOKS ON COURSE NEXT WEEK WITH TWO SYSTEMS
POISED TO IMPACT THE REGION TUESDAY AND FRIDAY. BOTH SYSTEMS WILL
BEGIN ON THE WARMER SIDE WITH SNOW LEVELS BEGINNING AROUND THE 6,000-
7,000 FOOT RANGE WITH HIGHER SNOW LEVELS AT THE ONSET EXPECTED FOR
THE FRIDAY SYSTEM. CONFIDENCE IS MEDIUM THAT THESE SYSTEMS WILL
IMPACT THE REGION AND RESULT IN TRAVEL DELAYS/CHAIN CONTROLS FOR
CROSS SIERRA TRAVEL. CONFIDENCE IS LOW HOWEVER IN REGARDS TO
PRECIPITATION TOTALS WITH CONSIDERABLE DIFFERENCES BETWEEN
DETERMINISTIC QPF MODEL SOLUTIONS AND ENSEMBLE PLUMES.
FOR TUESDAY`S SYSTEM, DID SIGNIFICANTLY INCREASE THE WINDS ACROSS THE
SIERRA AND WESTERN NEVADA WITH A TIGHT SURFACE GRADIENT DEVELOPING
AS 60KT+ OF WINDS AT 700MB(~10,000` MSL) CROSSES THE NORTHERN
SIERRA. THIS MAY RESULT IN HIGH END GUSTS NEAR 100 MPH OVER THE
SIERRA PEAKS AND 40-50 MPH DOWN THROUGH VALLEY LOCATIONS. ALSO
REDUCED PRECIPITATION CHANCES ACROSS WESTERN NEVADA TO REPRESENT
MORE SHADOWING TUESDAY MORNING WITH BEST POTENTIAL FOR SPILLOVER
RAINFALL TUESDAY AFTERNOON AS DYNAMICS ROLL THROUGH. SNOWFALL
AMOUNTS ARE QUITE LOW CONFIDENCE AS THE EC AND GFS SHOW NEARLY AN
ORDER OF MAGNITUDE DIFFERENCE IN QPF AMOUNTS. REGARDLESS, EVEN WITH
LOWER END SNOW AMOUNTS, STILL WOULD EXPECT SEVERAL INCHES OF SNOW
ACCUMULATION ACROSS THE SIERRA PASSES. TRAVELERS SHOULD CONTINUE TO
CLOSELY MONITOR THE FORECAST OVER THE NEXT FEW DAYS.
THERE WILL LIKELY BE A BREAK WED-THU AS SHORTWAVE RIDGE MOVES ACROSS
THE AREA. THE NEXT STORM IS DUE FRIDAY AFTERNOON INTO EARLY
SATURDAY. THIS ALSO APPEARS TO BE ANOTHER QUICK MOVING SYSTEM WHICH
WILL LIMIT BIG RAIN AND SNOW ACCUMULATION. SNOW LEVELS AT THIS POINT
ARE LOOKING TO BE EVEN HIGHER WITH RAINFALL POSSIBLY STARTING BELOW
7,000 FEET THROUGH FRIDAY AFTERNOON AND THEN FALLING TO LAKE LEVEL
SOMETIME FRIDAY EVENING. AGAIN TRAVEL IMPACTS ARE LIKELY THROUGH
THE SIERRA BUT CONFIDENCE IN DETAILS ARE INHERENTLY LOW BEING
ALMOST A WEEK OUT. FUENTES
&&
.AVIATION...
GUSTY WINDS WILL CONTINUE ACROSS ALL TERMINALS THROUGH THIS
EVENING. TURBULENCE ALONG AND DOWNSTREAM OF THE SIERRA WILL
PERSIST THIS AFTERNOON WITH GUSTS NEAR 70KTS EXPECTED. THE WINDS
ACROSS THE RIDGES WILL LULL TO LESS THAN 50KTS TONIGHT BEFORE
INCREASING BACK TO NEAR 80KTS SUNDAY AFTERNOON AS THE NEXT SYSTEM
APPROACHES. PERIODS OF MOUNTAIN TOP OBSCUREMENT WILL ALSO
CONTINUE.
THE NEXT WINTER SYSTEM WILL PROVIDE PERIODS OF MODERATE TO HEAVY
MOUNTAIN SNOW AND VALLEY RAIN, ESPECIALLY SUN NIGHT-MON MORNING.
ACCUMULATING SNOWFALL IS MOST LIKELY TO OCCUR AFTER 00Z MONDAY WHERE
AROUND 3-5 INCHES OF SNOWFALL IS POSSIBLE FOR KTRK AND KTVL WITH 1-
2" FOR KMMH. IFR CIGS AND VIS IN RAIN IS MOST LIKELY FOR KRNO AND
KCXP SUNDAY NIGHT WITH A MIX OF RAIN AND SNOW POSSIBLE BY MONDAY.
FUENTES
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...LAKE WIND ADVISORY UNTIL 7 PM PST THIS EVENING FOR LAKE TAHOE IN
NVZ002.
WINTER WEATHER ADVISORY FROM 4 PM SUNDAY TO 10 AM PST MONDAY
NVZ002.
CA...LAKE WIND ADVISORY UNTIL 7 PM PST THIS EVENING FOR LAKE TAHOE IN
CAZ072.
WINTER WEATHER ADVISORY FROM 4 PM SUNDAY TO 10 AM PST MONDAY
CAZ072.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
[top]
Area Forecast Discussion
National Weather Service Sacramento CA
201 PM PST SAT JAN 16 2016
.SYNOPSIS...
CURRENT SYSTEM WILL CONTINUE TO BRING SHOWERS TODAY WITH SOME
MOUNTAIN SNOW ACCUMULATION. WETTER SYSTEM EXPECTED SUNDAY THROUGH
EARLY MONDAY. SOME SMALL SCALE AND/OR BURN SCAR FLOODING COULD
OCCUR DURING THIS TIME. EXPECT PERIODS OF PRECIPITATION THROUGH
NEXT WEEK.
.SHORT TERM DISCUSSION (TODAY THROUGH TUESDAY)...
A series of storms will move through the region through Tuesday.
The current system is exiting the region with shower chances
continuing into the evening. Snow levels have been risen up to
around 7500 feet and will remain high through Tuesday but may dip
at times below major pass levels of US-50 and I-80. I have
modified the flash flood watch period to when the heavier rain is
expected to move through Lake County for Sunday afternoon and
evening. Timing of the later system on Tuesday may change a
little.
In the shorter term the NAM and HRRR models are indicating showers
enhancing around mid afternoon over the Southern Sacramento
Valley and Western Slopes of the Sierra Nevada. Showers should
taper some this evening then rain may start for places around I-80
and to the north later tonight and Sunday morning. The heaviest
rainfall is expected Sunday afternoon and evening. Sunday evening
snow levels look like they may lower below major Sierra pass
levels and have some impact on travel.
.EXTENDED DISCUSSION (Wednesday THROUGH Saturday)
Unsettled weather pattern will continue through next week as
several storms move into NorCal from the Pacific. Forecast timing
will likely fluctuate over the next several runs under this
progressive pattern, but confidence is high in both a midweek and
late-week storm over the region. Snow levels will generally remain
around 5000-7000 feet before lowering next weekend. Temperatures
will be close to average for mid-January.
Dang
&&
.AVIATION...
Wly flow alf as upr rdg movs thru tngt...bckg to SWly Sun as nxt
Pac fntl sys movs into Intr NorCal. For Cstl/Shasta mtns and
Cntrl Vly...wdsprd MVFR with areas IFR aft 12z Sun. Ovr Wrn
Plumas/Siernev lcl MVFR bcmg wdsprd MVFR/IFR with lcl LIFR aft 17z
Sun. Sn lvls genly aoa 055 msl. Lcl SEly sfc wnd gsts to 25 kts
Sun with SWly sfc wnd gsts to 40 kts poss ovr hyr mtn trrn.
&&
.STO Watches/Warnings/Advisories...
Flash Flood Watch from Sunday afternoon through Sunday evening
for Clear Lake/Southern Lake County-Mountains Southwestern
Shasta County to Northern Lake County.
&&
$$
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
241 PM MST SAT JAN 16 2016
.UPDATE...
UPDATED AVIATION AND FIRE WEATHER SECTIONS.
&&
.SYNOPSIS...
HIGH PRESSURE OVER THE WESTERN STATES WILL FLUCTUATE IN STRENGTH BUT
OVERALL KEEP ANY WEATHER SYSTEMS TO THE NORTH OF ARIZONA. TEMPERATURES
WILL WARM THIS WEEKEND PEAKING A BIT ABOVE NORMAL BY MONDAY...AND
REMAINING NEAR OR SLIGHTLY ABOVE SEASONAL NORMALS THROUGH NEXT
FRIDAY. DISTURBANCES PASSING THROUGH THE RIDGE WILL BRING PERIODS OF
MAINLY HIGH CLOUDS LEADING TO PARTLY SUNNY OR EVEN MOSTLY CLOUDY
SKIES AT TIMES.
&&
.DISCUSSION...
A RATHER BENIGN WEATHER PATTERN THROUGH THE UPCOMING WEEK WILL RESULT
IN DRY CONDITIONS AND WARMER TEMPERATURES ACROSS OUR AREA. SEVERAL
WEAK SHORTWAVE TROUGHS WILL MOVE THROUGH THE PREDOMINANTLY
NORTHWESTERLY FLOW...BUT FOR THE MOST PART ALL WILL PASS BY
HARMLESSLY TO OUR NORTH. THE FIRST SYSTEM WHICH IS CURRENTLY ENTERING
INTO THE GREAT BASIN WILL QUICKLY DROP SOUTHEASTWARD TONIGHT...BUT
BARELY SKIM NORTHERN ARIZONA. FOR OUR AREA WE ARE ONLY EXPECTING A
PERIOD OF THICKER HIGH CLOUDS THROUGH TONIGHT WHICH WILL KEEP
TEMPERATURES DOWN A BIT THIS AFTERNOON...BUT ALLOW FOR MORE MILD
OVERNIGHT TEMPERATURES.
UPPER LEVEL RIDGING WILL MOVE IN FOR SUNDAY WITH SIGNIFICANT WARMING
OCCURRING ALOFT...850MB TEMPERATURES RISE AROUND 5C OVER THE NEXT 24
HOURS. THIS WILL GIVE US A GOOD BUMP IN SURFACE TEMPERATURES AS
HIGHS RETURN TO AROUND NORMAL LEVELS WITH EVEN SOME LOWER 70S ACROSS
THE SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA DESERTS. GOING INTO
NEXT WEEK A COUPLE OTHER WEAK AND FAST MOVING SHORTWAVE TROUGHS WILL
SKIRT BY TO OUR NORTH...ONE MONDAY NIGHT AND THE OTHER EARLY
WEDNESDAY MORNING. THE ONLY SENSIBLE WEATHER FROM EITHER OF THESE
SYSTEMS WILL BE A PERIOD OF MID AND HIGH CLOUDS. THE WEDNESDAY SYSTEM
HAD LOOKED MORE IMPRESSIVE SEVERAL MODEL RUNS AGO...ENOUGH FOR SOME
PRECIP CHANCES IN PREVIOUS FORECAST PACKAGES...BUT NOW IT SEEMS WILL
ALSO PASS BY WELL TO OUR NORTH WITH ANY PRECIP CHANCES STAYING TO THE
NORTH OF OUR CWA.
TEMPERATURES THROUGH THE UPCOMING WEEK WILL REMAIN FAIRLY STABLE
THROUGH AROUND WEDNESDAY WITH HIGHS NEAR NORMAL AND LOWS A BIT WARMER
DUE TO INCREASED CLOUD COVER. LATER IN THE WEEK A STRONGER RIDGE IS
LIKELY TO TAKE SHAPE WITH 500MB HEIGHTS BUILDING TO NEAR 580DM. THIS
SHOULD RAISE DAYTIME HIGHS BY A FEW DEGREES WITH THE LOWER DESERTS
REACHING INTO THE LOWER 70S...OR AROUND FIVE DEGREES ABOVE NORMALS.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...AND
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
THICK MAINLY HIGH CLOUDS MOVING ACROSS THE AREA THIS AFTERNOON AND
TONIGHT. CEILINGS BOTTOM OUT AT ABOUT FL100-120 FOR A FEW HOURS BUT
MOSTLY REMAIN ABOVE FL150. PRECIP NOT EXPECTED TO REACH THE SURFACE
AT TAF SITES...THOUGH SPRINKLES CANNOT BE RULED OUT. CLOUDS BEGIN TO
THIN OUT FROM WEST TO EAST AFTER 06Z. SURFACE WINDS REMAIN LIGHT
THE REST OF THE AFTERNOON THROUGH SUNDAY.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
HIGH PRESSURE WILL GENERALLY REMAIN IN PLACE OVER THE INTERIOR WESTERN
STATES GETTING WEAKENED FROM TIME TO TIME BY STORMS THAT PASS TO OUR
NORTH...ONLY BRUSHING ARIZONA AND SOUTHEAST CALIFORNIA. CHANCES FOR
ANY WETTING RAINS DURING THE WEEK WILL BE SLIM. HUMIDITIES INCREASE
BY WEDNESDAY DUE TO A PASSING WEATHER DISTURBANCE. THIS WILL BE
FOLLOWED BY DECLINING HUMIDITIES BUT REMAINING ABOVE 20 PERCENT.
OVERNIGHT RECOVERY REMAINS GOOD. TEMPERATURES WILL REMAIN NEAR NORMAL
THE FIRST HALF OF THE WEEK FOLLOWED BY A FEW DEGREES OF WARMING
DURING THE LATTER HALF. WINDS ON THE VALLEY FLOORS WILL REMAIN
LIGHT...OCCASIONAL BREEZINESS AT RIDGETOPS...FAVORING NORTH AND EAST
DIRECTIONS.
&&
.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT BASED ON STANDARD OPERATING
PROCEDURES.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...KUHLMAN
AVIATION...AJ
FIRE WEATHER...AJ
Area Forecast Discussion
National Weather Service Sacramento CA
137 PM PST SAT JAN 16 2016
.SYNOPSIS...
CURRENT SYSTEM WILL CONTINUE TO BRING SHOWERS TODAY WITH SOME
MOUNTAIN SNOW ACCUMULATION. WETTER SYSTEM EXPECTED SUNDAY THROUGH
EARLY MONDAY. SOME SMALL SCALE AND/OR BURN SCAR FLOODING COULD
OCCUR DURING THIS TIME. EXPECT PERIODS OF PRECIPITATION THROUGH
NEXT WEEK.
.SHORT TERM DISCUSSION (TODAY THROUGH TUESDAY)...
A series of storms will move through the region through Tuesday.
The current system is exiting the region with shower chances
continuing into the evening. Snow levels have been risen up to
around 7500 feet and will remain high through Tuesday but may dip
at times below major pass levels of US-50 and I-80. I have
modified the flash flood watch period to when the heavier rain is
expected to move through Lake County for Sunday afternoon and
evening. Timing of the later system on Tuesday may change a
little.
In the shorter term the NAM and HRRR models are indicating showers
enhancing around mid afternoon over the Southern Sacramento
Valley and Western Slopes of the Sierra Nevada. Showers should
taper some this evening then rain may start for places around I-80
and to the north later tonight and Sunday morning. The heaviest
rainfall is expected Sunday afternoon and evening. Sunday evening
snow levels look like they may lower below major Sierra pass
levels and have some impact on travel.
.EXTENDED DISCUSSION (Wednesday THROUGH Saturday)
Unsettled weather pattern will continue through next week as
several storms move into NorCal from the Pacific. Forecast timing
will likely fluctuate over the next several runs under this
progressive pattern, but confidence is high in both a midweek and
late-week storm over the region. Snow levels will generally remain
around 5000-7000 feet before lowering next weekend. Temperatures
will be close to average for mid-January.
Dang
&&
.AVIATION...
Widespread MVFR and local IFR conditions in the Central Valley
with widespread IFR/LIFR conditions in the mountains during the
next 24 hours. Numerous showers, tapering off by around 00Z
Sunday. Snow levels generally 050-070. Local southwesterly winds
gusts 30-40 kts possible over higher terrain.
&&
.STO Watches/Warnings/Advisories...
Flash Flood Watch from Sunday afternoon through Sunday evening
for Clear Lake/Southern Lake County-Mountains Southwestern
Shasta County to Northern Lake County.
&&
$$
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
1205 PM PST SAT JAN 16 2016
...NEW AVIATION/MARINE/BEACHES DISCUSSIONS...
.SYNOPSIS...
A SERIES OF WEAK FRONTAL SYSTEMS ARE EXPECTED TO MOVE THROUGH THE
AREA DURING THE NEXT SEVEN DAYS...BRINGING THE POSSIBILITY OF LIGHT
RAIN MAINLY TO THE NORTH OF SANTA BARBARA. OTHERWISE SURFACE HIGH
PRESSURE ALOFT WILL SUPPORT FAIR SKIES AND SEASONABLE TEMPERATURES.
&&
.SHORT TERM (TODAY-MON)..A WEAK COLD FRONT THAT MOVED INTO THE
CENTRAL COAST EARLY THIS MORNING HAS FOR THE MOST PART DISSIPATED. A
FEW LEFTOVER SHOWERS WERE NOTED ON RADAR OVER THE SBA COUNTY
MTNS...CUYAMA VLY AND EXTREME SERN SLO COUNTY. THESE MAINLY LIGHT
SHOWERS WILL MOVE INTO THE VTU MTNS THIS MORNING...WITH A FEW
SHOWERS NOT OUT OF THE QUESTION FOR THE NRN SLOPES THE THE L.A.
COUNTY MTNS AND ANTELOPE VLY FOOTHILLS INTO THIS AFTERNOON.
OTHERWISE...MOSTLY CLOUDY SKIES COVERED SOUTHWESTERN CA THIS
MORNING. THE MOSTLY CLOUDY SKIES ARE FORECAST TO PERSIST FOR THIS
AFTERNOON ALTHOUGH SOME SUNSHINE WILL BE PREVALENT AT TIMES.
TEMPERATURES THIS AFTERNOON SHOULD BE NEAR NORMAL TO SLIGHTLY ABOVE
NORMAL ACROSS THE REGION.
WEAK UPPER LEVEL RIDGING WILL PERSIST OVER SRN CA TODAY THROUGH SUN.
A WEAK UPPER LEVEL TROUGH AND SURFACE COLD FRONT WILL THEN MOVE
THROUGH THE AREA SUN NIGHT AND MON.
DRY WEATHER SHOULD COVER THE FORECAST AREA TONIGHT AND SUN...ALTHO A
FEW SHOWERS OUT AHEAD OF THE COLD FRONT SHOULD START TO MOVE INTO
FAR NWRN SLO COUNTY BY LATE IN THE DAY ON SUN. MARINE LAYER LOW
CLOUDS AND FOG CAN BE EXPECTED SUN MORNING FOR THE L.A. COUNTY
CST...VLYS AND SANTA MONICA MTNS...OTHERWISE PARTLY CLOUDY SKIES AS A
WHOLE SHOULD COVER THE REGION.
THE COLD FRONT SHOULD CONTINUE TO APPROACH THE CENTRAL COAST SUN
NIGHT WITH INCREASING CHANCES OF RAIN OVER SLO/SBA COUNTY...BUT
ESPECIALLY FOR FAR NWRN SLO COUNTY WHERE RAIN SHOULD BECOME LIKELY
BY LATE SUN NIGHT. THE COLD FRONT IS FORECAST TO MOVE INTO SLO/SBA
COUNTIES MON MORNING THEN MOVE SOUTH THRU L.A./VTU COUNTIES WHILE
WEAKENING MON AFTERNOON AND EARLY EVENING. RAIN WILL BE LIKELY OVER
SLO/SBA COUNTIES MON MORNING THEN DIMINISH TO A CHANCE OF RAIN MON
AFTERNOON. FOR VTU/L.A. COUNTIES...JUST A CHANCE OF RAIN IS EXPECTED
AS THE FRONT WEAKENS FAIRLY QUICKLY. PROJECTED RAINFALL AMOUNTS SUN
NIGHT AND MON ARE FOR ABOUT 0.25 INCH OR LESS TO OCCUR OVER SLO/SBA
COUNTIES...EXCEPT UP TO 0.70 INCH FOR NWRN SLO COUNTY ESPECIALLY IN
THE HILLS...AND GENERALLY LESS THAN 0.05 INCH FOR VTU/L.A. COUNTIES.
SNOW LEVELS ON MON ARE EXPECTED TO BE VERY HIGH AND ABOVE RESORT
LEVEL.
TEMPS ACROSS THE REGION ARE FORECAST TO BE NEAR TO SLIGHTLY ABOVE
NORMAL ON SUN...THEN COOL SLIGHTLY ON MON TO NEAR TO SLIGHTLY BELOW
NORMAL FOR THE MOST PART.
***FROM PREVIOUS DISCUSSION***
.LONG TERM (TUE-FRI)...
BOTH GFS AND ECMWF ADVERTISE ANOTHER FRONTAL BOUNDARY MOVING INTO
THE CENTRAL COAST ON TUESDAY. THE GFS HAS BEEN FLIP-FLOPPING ON
THE STRENGTH OF THE COLD FRONT. THE EC IS MUCH WEAKER AND MORE
CONSISTENT. THEREFORE FEEL LIKE THE WEAKER EUROPEAN MODEL WOULD
BE MORE TRUSTWORTHY. HOPEFULLY AS WE DRAW CLOSER...THE MODELS
WILL BE IN SYNC WITH THE SPEED AND STRENGTH OF STORM. ONCE
AGAIN...LIGHT RAINFALL AMOUNTS TO THE NORTH...WITH LESS THAN A
TENTH OF AN INCH FOR LA/VTU COUNTIES. A RIDGE BEHIND THE FRONT
WILL BUILD. THIS WILL HELP WARM THE COAST AND VALLEYS UP A FEW
MORE DEGREES BOTH WED AND THU. NO RAIN EXPECTED ON WED/THU FOR THE
FORECAST AREA HIGHS SHOULD REACH THE LOWER 70S BY MID WEEK. AND
YET ANOTHER UPPER TROUGH IS EXPECTED TO SWING SOUTHEAST INTO
CENTRAL CALIFORNIA...THEN SPREAD OVER SOUTHERN CALIFORNIA BY
FRIDAY AFTERNOON.
&&
.AVIATION...16/1800Z.
AT 1758Z...AT KLAX...THE MARINE LAYER WAS 2800 FEET DEEP WITH A WEAK
INVERSION TO 4800 FEET. TEMPERATURE WAS 10 DEGREES C AT 4800 FT.
MANY TAF SITES...MAINLY SOUTH OF POINT CONCEPTION...WERE TWEAKED TO
CUT DOWN ON THE DURATION OF MVFR CEILINGS TODAY BEFORE MVFR CEILINGS
RETURN AGAIN TONIGHT. THE LIGHT RAIN SHOWERS SEEN EARLIER THIS
MORNING ON THE CENTRAL COAST HAVE ALL BUT DISAPPEARED FOR THE TIME
BEING. WINDS ARE EXPECTED TO REMAIN ON THE LIGHT SIDE.
KLAX...MODERATE CONFIDENCE IN THE 18Z TAF. THE MAIN SOURCE OF
UNCERTAINTY LIES IN THE PRESENCE OF BRIEF TRANSITORY MVFR CIELINGS
DURING THE DAY TODAY AND THE TIMING OF THE ONSET OF MORE PERSISTENT
MVFR CEILINGS EXPECTED TONIGHT.
KBUR...MODERATE CONFIDENCE IN THE 18Z TAF. THERE IS A 30 PERCENT
CHANCE OF MVFR CEILINGS TONIGHT.
&&
.MARINE...16/900 AM...
LOCAL GUSTS TO 25 KT ARE POSSIBLE NEAR PT CONCEPTION AND IN THE
VICINITY OF THE CHANNEL ISLANDS LATE THIS AFTERNOON AND EVENING.
OTHERWISE...WINDS SHOULD GENERALLY REMAIN BELOW SMALL CRAFT ADVISORY
CRITERIA THROUGH TUESDAY. A LARGE NW SWELL OF 15-17 FEET AT 18-20
SECONDS WILL ENTER THE COASTAL OUTER WATER FROM NORTH TO SOUTH LATE
TONIGHT WITH SWELLS 7 TO LOCALLY 10 FEET EXPECTED ACROSS THE INNER
WATERS BY EARLY MONDAY MORNING. SMALL CRAFT ADVISORIES FOR HAZARDOUS
SEAS HAVE BEEN ISSUED FOR THE OUTER WATERS AND MAY BE NEEDED FOR THE
INNER WATERS BY SUNDAY. THE LARGE SWELL WILL PRODUCE BREAKING WAVES
AT THE MORRO BAY AND VENTURA HARBOR ENTRANCES SUNDAY INTO
MONDAY...WHEN THE SWELL IS EXPECTED TO PEAK.
&&
.BEACHES...A LARGE AND LONG PERIOD WEST TO NORTHWEST SWELL WILL
IMPACT THE BEACHES OF SOUTHWEST CALIFORNIA LATE SATURDAY AFTERNOON
THROUGH AT LEAST TUESDAY. THE HIGH SURF ADVISORY FOR FOR THE CENTRAL
COAST WAS UPGRADED TO A HIGH SURF WARNING...WHERE SURF WILL PEAK AT
15-20 FT WITH LOCAL SETS TO 25 FT LATE SATURDAY NIGHT THROUGH EARLY
SUNDAY MORNING. A HIGH SURF ADVISORY REMAINS IN EFFECT FOR ALL AREAS
SOUTH OF POINT CONCEPTION. THE LARGEST SURF SOUTH OF POINT
CONCEPTION IS EXPECTED ON WEST-FACING BEACHES SUCH AS THOSE NEAR THE
VENTURA HARBOR...WHERE SETS TO 15 FEET WILL BE POSSIBLE SUNDAY
THROUGH MONDAY. THERE IS AN OUTSIDE CHANCE THAT A HIGH SURF WARNING
WILL BE NEEDED FOR THE VENTURA COAST. MAIN IMPACTS WITH THIS HIGH
SURF EVENT WILL LIKELY BE BEACH EROSION...DANGEROUS RIP
CURRENTS...AND SNEAKER WAVES. DAMAGE TO COASTAL STRUCTURES WILL ALSO
BE POSSIBLE ON THE CENTRAL COAST AND NEAR THE VENTURA HARBOR.
COASTAL FLOODING IS NOT EXPECTED TO BE A MAJOR ISSUE AT THIS
TIME...AS THE HIGHEST HIGH TIDES WILL GENERALLY BE BETWEEN 5.5 AND 6
FT. HOWEVER...MINOR COASTAL FLOODING WILL BE POSSIBLE. THE HIGHEST
HIGH TIDES WILL OCCUR BETWEEN 3AM AND 5AM SATURDAY NIGHT THROUGH
MONDAY NIGHT.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH SURF WARNING (SEE LAXCFWLOX)
HIGH SURF ADVISORY (SEE LAXCFWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).
MARINE WEATHER STATEMENT (SEE LAXMWSLOX).
&&
$$
PUBLIC...SIRARD/KAPLAN
AVIATION/MARINE/BEACHES...SWEET
SYNOPSIS...MUNROE
WWW.WEATHER.GOV/LOSANGELES
Area Forecast Discussion
National Weather Service Sacramento CA
1009 AM PST SAT JAN 16 2016
.SYNOPSIS...
CURRENT SYSTEM WILL CONTINUE TO BRING SHOWERS TODAY WITH SOME
MOUNTAIN SNOW ACCUMULATION. WETTER SYSTEM EXPECTED SUNDAY THROUGH
EARLY MONDAY. SOME SMALL SCALE AND/OR BURN SCAR FLOODING COULD
OCCUR DURING THIS TIME. EXPECT PERIODS OF PRECIPITATION THROUGH
NEXT WEEK.
.SHORT TERM DISCUSSION (TODAY THROUGH TUESDAY)...
A series of storms will move through the region through Tuesday.
The current system is exiting the region with shower chances
continuing today. Snow levels have been risen up to around 7500
feet and will remain high through Tuesday but may dip at times
below major pass levels of US-50 and I-80. I have modified the
flash flood watch period to when the heavier rain is expected to
move through Lake County for Sunday afternoon and evening. Timing
of the later system on Tuesday may change a little.
In the shorter term the NAM and HRRR models are indicating showers
enhancing around mid afternoon over the Southern Sacramento
Valley and Western Slopes of the Sierra Nevada. Showers should
taper some this evening then rain may start for places around I-80
and to the north later tonight and Sunday morning. The heaviest
rainfall is expected Sunday afternoon and evening.
.EXTENDED DISCUSSION (Wednesday THROUGH Saturday)
Unsettled pattern will continue through next week as several storms
move into NorCal from the Pacific. Differences in timing and
strength remain between model solutions, but appears the best
chance for precipitation will be on Thursday and Friday. Period
likely won`t be as wet as current pattern. Snow levels will be
generally around 5000-7000 feet before lowering next weekend.
Temperatures will be close to average for mid-January.
&&
.AVIATION...
Widespread MVFR and local IFR conditions in the Central Valley
with widespread IFR/LIFR conditions in the mountains during the
next 24 hours. Numerous showers, tapering off by around 00Z
Sunday. Snow levels generally 040-050 rising to 050-060 after 00Z
Sunday. Local southwesterly winds gusts 30-40 kts possible over
higher terrain after 18Z.
&&
.STO Watches/Warnings/Advisories...
Flash Flood Watch from Sunday afternoon through Sunday evening
for Clear Lake/Southern Lake County-Mountains Southwestern
Shasta County to Northern Lake County.
&&
$$
AREA FORECAST DISCUSSION
NWS CARIBOU ME
136 PM EST SAT JAN 16 2016
.SYNOPSIS...
LOW PRESSURE FROM THE SOUTHWEST WILL TRACK SOUTH OF THE AREA THIS
AFTERNOON AND THEN MOVE EAST TOWARD THE OPEN ATLANTIC TONIGHT.
WEAK HIGH PRESSURE BUILDS BACK TOWARD THE AREA SUNDAY. UPPER LEVEL
LOW PRESSURE WITH WEAK SURFACE LOW PRESSURE WILL APPROACH DOWNEAST
MAINE SUNDAY NIGHT AND CROSS THE REGION ON MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
130 PM UPDATE...DECIDED TO UPGRADE INTERIOR DOWNEAST AND THE COAST
TO WINTER STORM WARNINGS DUE TO THE SLOW MOVING HEAVY SNOW BAND
NEAR THE COAST. GETTING REPORTS OF UP TO 2 INCHES/HR IN THAT BAND.
REPORTS COMING IN W/UP TO 3 INCHES OF SNOW FROM THIS LATEST EVENT
AND CONTINUE TO ACCUMULATE. LATEST 18Z ANALYSIS SHOWED COASTAL
FRONT OFF THE COAST W/SFC LOW PASSING WELL SE OF THE AREA. ALOFT,
UPPER LOW HEADING OVER THE THE GULF OF MAINE AID IN MID LEVEL
FORCING. DECNET FRONTOGENETICAL FORCING IN PLACE WHERE THE HEAVY
SNOW IS OCCURRING. LATEST NAM12 AND RAP DOING WELL TO CATCH THIS
SETUP. GIVEN THE PROLONGED NATURE OF THE BAND AND HIGH SNOW RATIO,
DECIDED TO TO GO W/6-9 INCHES OF SNOW. HIGHER END OF THE RANGE
WILL BE ACROSS CENTRAL AND WASHINGTON COUNTY.
THE WINTER WEATHER ADVISORIES FURTHER N STAND AS IS FOR NOW.
STARTING TO SEE ENHANCED BANDS SETTING UP ACROSS THE MT. KATAHDIN
REGION. 3-6 INCHES FOR THE ADVISORY LOOKS GOOD ATTM.
PREVIOUS DISCUSSION...PRIMARY LOW PRESSURE IS CURRENTLY
POSITIONED OVER EASTERN LAKE HURON, WITH THE SECONDARY HAVING
MOVED OFF THE DELMARVA COAST, WITH A TROUGH STRETCHED BETWEEN
THEM. THE ECMWF SEEMS TO HAVE THE BEST HANDLE ON THE SITUATION
ATTM, THOUGH THE GFS IS DOING REASONABLY WELL. BOTH LOWS WILL
SLOWLY PUSH NORTHEASTWARD TODAY, WITH THE PRIMARY GRADUALLY GIVING
WAY TO THE SECONDARY. THE LATEST MODEL TRENDS HAVE BEEN TO KEEP
THE SECONDARY FURTHER OFF SHORE. THIS DOES A FEW THINGS...(1)
LIMITS THE AMOUNT OF MOISTURE/QPF ACROSS OUR AREA, ESPECIALLY IN
THE NORTH (2) KEEPS THE BEST FORCING OFF SHORE (3) AND LIMITS THE
AMOUNT OF WARM AIR THAT WILL SPREAD NORTHWARD AHEAD OF THE PRIMARY
LOW. AS A RESULT, EXPECT THE SNOW LINE WILL REMAIN SOUTH OF
BANGOR, WITH A MIX OF SLEET/SNOW/FREEZING RAIN LIKELY ACROSS
MAINLY COASTAL HANCOCK AND WASHINGTON COUNTIES LATE THIS MORNING
AND EARLY AFTERNOON. ANY PERIODS OF JUST PLAIN RAIN, IF THEY OCCUR
AT ALL, WILL BE VERY BRIEF AND LIMITED TO THE IMMEDIATE COAST.
ONCE THE SECONDARY LOW MOVES TO OUR EAST EARLY THIS AFTERNOON,
COLDER AIR WILL QUICKLY RUSH IN BEHIND IT, RAPIDLY CHANGING ANY
MIXED PRECIP TO ALL SNOW. ICE ACCUMULATION IS STILL EXPECTED TO BE
AROUND A TENTH OF AN INCH AT MOST, BUT SNOWFALL AMOUNTS HAVE BEEN
INCREASED, ESPECIALLY ALONG THE IMMEDIATE COAST. WIDESPREAD 4-8
INCHES OF SNOW IS EXPECTED SOUTH OF A HOULTON TO BILLY-JACK DEPOT
LINE. NORTH OF THIS LINE, HAVE LOWERED AMOUNTS A BIT WITH 2-4
INCHES TO OCCUR. THE STEADIEST PRECIPITATION WILL OCCUR ROUGHLY 1
PM TO 6 PM, THEN GRADUALLY TRANSITION TO SHOWERS FROM SOUTH TO
NORTH AS THE SECONDARY LOW PULLS AWAY AND THE SURFACE TROUGH
CROSSES THE STATE.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
SUN LOOKS TO BE DRIER THAN IT DID YSTDY ATTM...WITH ALMOST ALL
MODELS NOW MUCH MORE PROGRESSIVE WITH MOVING THE E-W SFC TROF WELL
NE OF THE REGION BY AFTN. ANY REMAINING SN SHWRS WILL BE EXITING
THE ST JOHN VLY AREA BY EARLY SUN MORN...WITH SKIES PERHAPS
BECOMING PTLY SUNNY BY AFTN EVEN ACROSS THE N. HI TEMPS LOOK TO BE
NEAR SEASONAL NORMS.
AFT MCLR SKIES SUN EVE...CLDS INCREASE FROM THE W AS UPPER LVL LOW
PRES FROM CNTRL CAN APCHS. WEAK SFC LOW PRES AHEAD OF THIS FEATURE
WILL EXIT THE MID MAINE COAST WITH AN E-W TROF AXIS ON MON...SUGGESTING
THE POSSIBILITY OF NORLUN TROF NARROW BANDED SNFL SOMEWHERE ALG
THE MAINE COAST...BUT IT`S TO EARLY TO SAY EXACTLY WHERE. FOR THIS
REASON WE LIMIT MAX POPS TO THE LIKELY CATEGORY ALG THE COAST ON
MON UNTIL WE GET CLOSER TO THE EVENT AND GET MORE CERTAINTY AS TO
WHAT PTN OF ME COAST WILL BE GREATEST IMPACTED WITH THIS FEATURE.
WITH DEEP LOW TO MID LVL COLD ADVCN INCREASING ACROSS THE REGION N
OF DOWNEAST AREAS ON MON AS THE UPPER LOW CROSSES THE REGION...PRECIP
NWRD OF THE COAST WILL BE MAINLY JUST SCT SN SHWRS AS SFC WINDS
BACK FROM THE NNE TO NW...KEEPING ANY LLVL ATLC MOISTURE IN THE
VCNTY OF THE NORLUN TROF. HI TEMPS MON WILL BE AOB NORMAL WITH
LLVL COLD ADVCN AFT RELATIVELY MILD OVRNGT LOWS SUN NGT DUE TO
INCREASING CLD CVR. MON NGT WILL BE MSLY CLDY WITH FLURRIES AND
SCT SN SHWRS MSLY ACROSS THE N HLF OF THE FA AS WEAK LLVL WARM
OCCLUSION PIVOTS SWRD TOWARD THE REGION FROM ERN QB.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
TEMPS LOOK TO BE A LITTLE MILDER BY LATE TUE FOLLOWING THE PASSAGE
OF A WEAK WARM OCCLUSION FROM NW TO SE ACROSS THE REGION WITH
CLDNSS AND SCT SN SHWRS SPCLY ACROSS THE NW. GUSTY NW WINDS TUE
WILL MASK ANY IMPROVEMENT IN HI TEMPS TUE. WINDS CONT INTO THE NGT
TUE NGT AS SOME CLRG IS XPCTD BY LATE TUE NGT. WED LOOKS TO BE
CONTD BRISK AND SEASONABLY COLD UNDER PTLY TO MSLY SUNNY SKIES.
AFT SOME INCREASE IN CLDNSS WED NGT...THU AND FRI LOOK TO BE
UNSETTLED WITH PERIODIC CLDNSS AND OCNL LGT SN SHWRS DUE THE
PASSAGE OD SEVERAL WEAK/WVS TRACKING EWRD OVR THE REGION FROM
CNTRL CAN/QB. THERE WILL BE LESS THAN THE NORMAL DIURNAL SPREAD
BETWEEN DYTM HI TEMPS AND NGT TM LOWS THU AND FRI DUE TO THIS CLD
CVR...WITH SEASONAL DAY TM HI TEMPS AND SOMEWHAT MILDER OVRNGT
LOWS.
&&
.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
NEAR TERM: MVFR CONDITIONS ARE EXPECTED TO PREVAIL AT ALL
TERMINALS THIS MORNING, BUT THEY WILL DROP TO IFR DURING THE
AFTERNOON AS SNOW SPREADS ACROSS THE REGION. KBGR AND KBHB WILL
SEE THE HEAVIEST SNOW, WITH FREEZING RAIN AND SLEET LIKELY TO MIX
IN AT KBHB DURING THE AFTERNOON. PRECIPITATION WILL COME TO AN END
AT THE SOUTHERN TERMINALS AFTER 06Z, WITH CEILINGS LIFTING TO
MVFR. HOWEVER, SNOW SHOWERS AND IFR CONDITIONS WILL CONTINUE
THROUGH 12Z SUN AT THE NORTHERN SITES.
SHORT TO LONG TERM: MSLY MVFR CLGS N AND VFR CLGS DOWNEAST SITES
THRU TUE...WITH IFR CLGS/VSBYS POSSIBLE MON WITH A PD OF SNFL.
THEN ALL SITES SHOULD BE VFR WED.
&&
.MARINE...
NEAR TERM: A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR TODAY.
STRENGTHENING LOW PRESSURE WILL PASS TO THE SOUTH OF THE WATERS,
RESULTING IN INCREASING WINDS AND SEAS. A FEW GUSTS TO AROUND 35 KT
WILL BE POSSIBLE THIS AFTERNOON, BUT EXPECT CONDITIONS WILL RAPIDLY
IMPROVE THROUGH THE EVENING HOURS AS THE LOW PULLS INTO THE
MARITIMES.
SHORT TO LONG TERM: BELOW TO MARGINAL SCA CONDITIONS ARE MSLY
XPCTD...WITH A PD OF STRONG SCA CONDITIONS XPCTD MON NGT INTO
WED...WITH POTENTIAL GALE FORCE GUSTS POSSIBLE AT TMS. KEPT CLOSE
TO WW3 WV GUIDANCE FOR FCST WV HTS AND CAPPED MAX WIN GUSTS FOR
NOW TO LESS THAN 32 KT...BUT MAX WIND GUSTS MAY BE RAISED IF THE
POTENTIAL OF GALE FORCE WINDS INCREASE WITH FUTURE FCST UPDATES.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR MEZ005-
006-010-011-031-032.
WINTER STORM WARNING UNTIL MIDNIGHT EST TONIGHT FOR MEZ015>017-
029-030.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR
ANZ050>052.
&&
$$
NEAR TERM...HEWITT
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
435 PM EST SAT JAN 16 2016
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 434 PM EST SAT JAN 16 2016
WV IMAGERY AND RAP ANALYSIS INDICATED A COLD MID/UPPER LEVEL LOW
JUST NE OF WINNIPEG. AT THE SFC...WINDS WERE BACKING AHEAD OF THE
LOW WHICH HAS PUSHED THE HEAVIER LES BAND IN ERN LAKE SUPERIOR TO
THE E MUNSING. LAKE INDUCED TROUGHING EXTENDED FROM SRN INTO W CNTRL
LAKE SUPERIOR RESULTING IN THE STRONGEST LOW LEVEL CONV INTO THE
KEWEENAW NEAR HOUGHTON WHERE A VERY HEAVY LES BAND HAS PRODUCED
HIGHER SNOWFALL RATES OF A FEW INCHES PER HOUR.
TONIGHT...DEEP COLD AIR WILL CONTINUE TO SETTLE OVER THE REGION
TONIGHT WITH 850 MB TEMPS INTO THE -21C TO -25C RANGE AND 700 MB
TEMPS TO AROUND -30C. THE VERY STRONG INSTABILITY WITH LAKE INDUCED
CAPE TO 1K J/KG AND EQUILLIBRIUM HEIGHTS TO 14K FT WILL CONTINUE TO
SUPPORT THE DEVELOPMENT OF INTENSE LES BANDS. THE STRONG CONVECTION
OVER THE LAKE WILL ALSO HELP TO KEEP THE DGZ IN THE CONVECTIVE LAYER
WITH FLUFFY SNOW SLR VALUES TO AT LEAST 25/1.
AS THE MID LEVEL LOW MOVES INTO LAKE SUPERIOR...THE MODELS SUGGEST
THAT THE TROUGH TO NEAR CMX WILL GRADUALLY SINK TO THE SOUTH.
SO...ALTHOUGH HIGHER SNOWFALL RATES WILL CONTINUE...THE HEAVIER
BANDS ARE NOT EXPECTED TO REMAIN IN PLACE FOR AN EXTENDED PERIOD.
HOWEVER...ADDITIONAL SNOW AMOUNTS OF 4 TO 8 INCHES ARE EXPECTED
TONIGHT...HEAVIEST FROM CMX TO MASS CITY AND THE PORCUPINES.
OVER THE EAST...THE HEAVIEST SNOW THIS EVENING IS EXPECTED NEAR
LAKE SUPERIOR CLOSER TO PICTURED ROCKS AND GRAND MARAIS. THE HIGH
RES MODELS HAVE BEEN CONSISTENT IN SHOWING A SHARP TROUGH OR MESO LOW
DEVELOPING OVER S CNTRL LAKE SUPERIOR AND SLIDING INTO ALGER COUNTY.
STRONG LOW LEVEL CONV ASSOCIATED ON THE WRN EDGE OF THIS FEATURE WILL
BRING HEAVY LES INTO MAINLY ALGER COUNTY BTWN 06Z-12Z WITH CONTINUED
HEAVIER NNW TO NW FLOW LES BANDS SUN MORNING. THERE IS MORE
UNCERTAINTY ON HOW FAR WEST THE BAND WILL MOVE. LAND BREEZE
DEVELOPMENT SHOULD BE STRONG ENOUGH TO KEEP THE STRONGEST LES EAST OF
MARQUETTE WITH ONLY SOME LIGHTER BANDS ON THE EDGE OF THE LOW FARTHER
TO THE WEST. THE QUICK BURST OF SNOW COULD RESULT IN SNOWFALL RATES
OF 1 TO 3 INCHES PER HOUR FOR A FEW HOURS...ESPECIALY OVER WRN ALGER
COUNTY.
THE VERY COLD AIR MOVING INTO INTERIOR LOCATIONS WILL DROP WIND
CHILLS INTO THE -20 TO -30 RANGE NEAR THE WI BORDER FROM IRONWOOD TO
CRYSTAL FALLS WHERE A WIND CHILL ADVY WAS ISSUED. EXPECT ENOUGH LAKE
MODERATION FARTHER NORTH FOR WIND CHILLS MAINLY IN THE -10 TO -20
RANGE.
SUNDAY...AFTER THE BURST OF HEAVIER SNOW IN THE MORNING OVER MAINLY
WRN ALGER COUNTY...THE LES IS EXPECTED TO EVOLVE INTO LIGHT TO
MODERATE MULTIPLE WIND PARALLEL BANDS WITH A FEW HEAVIER EMBEDDED
BANDS. WHILE MORNING SNOW TOTALS COULD REACH 6 INCHES...AFTERNOON
AMOUNTS SHOULD MAINLY BE IN THE 2 TO 4 INCH RANGE.
OVER THE WEST....A SHORTER FETCH AND LESS FAVORABLE LOW LEVEL CONV
WITH THE SLOWLY BACKING NW FLOW WILL KEEP AMOUNTS IN THE 2 TO 5 INCH
RANGE. IN ADDITION...THE DGZ FALLING CLOSER TO THE LAKE SFC WILL
INHIBIT SNOW GROWTH WITH MAINLY SMALLER FLAKES THAT CAN LEAD TO LOW
VSBY.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 409 PM EST SAT JAN 16 2016
MAIN ATTENTION IS ON HEALTHY LES SUN NIGHT AND MON THAT WILL
DIMINISH MON NIGHT AND TUE.
THE UPPER LOW THAT IS BRINGING THIS MASS OF COLD AIR WILL JUST E OF
THE CWA AT 00Z MON...850MB TEMPS WILL BE AROUND -23C TO START SUN
NIGHT. MODERATE TO HEAVY LES WILL BE ONGOING IN THE NW WIND
SNOWBELTS AT 00Z MON...ESPECIALLY IN AREAS E OF MARQUETTE COUNTY.
SHOULD SEE OVERALL STEADY LES SUN NIGHT INTO MUCH OF MON...WITH
DIMINISHING STARTING IN THE AFTERNOON W AND IN THE EVENING E AS THE
UPPER LOW MOVES AWAY...850MB TEMPS WARM BY 4-5 DEGREES AND WARMER
AND DRIER AIR MOVES IN ABOVE THE MOIST LAKE INFLUENCED LAYER. LAKE
INDUCED EQUILIBRIUM LEVELS SHOULD RANGE FROM 10KFT AT CMX TO 15KFT
AT GRAND MARAIS AT 00Z SUN...LOWERING BY AROUND 3KFT BY 12Z
SUN...THEN GRADUALLY DROPPING TO AROUND 6KFT OVER MOST OF THE LAKE
BY 00Z TUE. A SHORTWAVE DROPPING ACROSS LAKE SUPERIOR MON AFTERNOON
SHOULD HELP OFFSET SOME OF THE AFOREMENTIONED INCREASINGLY
UNFAVORABLE FEATURES. BETWEEN 00Z MON AND 00Z TUE...EXPECT ANOTHER 3-
5 INCHES OVER NW UPPER MI AND 6-10 INCHES OVER THE NW WIND FAVORED
AREAS OF ERN UPPER MI (MAINLY E OF MARQUETTE COUNTY). EXPECT WINDS
TO INCREASE SUN NIGHT INTO MON...WITH GUSTS UP TO 35MPH ALONG THE
SHORELINES E OF MARQUETTE AND 25-30MPH ELSEWHERE NEAR LAKE SUPERIOR.
THIS WILL PRODUCE QUITE A BIT OF BLOWING SNOW...ESPECIALLY ALONG M-
28 E OF HARVEY (NOT AS MUCH AS IF THERE WAS SIGNIFICANT ICE COVER ON
LAKE SUPERIOR AS IN YEARS PAST). MON NIGHT WILL SEE MODERATE SNOW
POTENTIAL EARLY...BUT INVERSIONS WILL BE LOWERING AND 850MB TEMPS
INCREASING TO AROUND -14C AS A SFC RIDGE MOVES TO W OF LAKE
SUPERIOR. LES WILL CONTINUE TO DIMINISH ON TUE...WITH ONLY LIGHT LES
EXPECTED...BUT WILL NOT COMPLETELY END.
SUN NIGHT AND MON MORNING WILL ALSO BE QUITE COLD WITH LOWS IN THE
SINGLE DIGITS ABOVE AND BELOW ZERO IN MOST PLACES...AROUND -10 ALONG
THE WI BORDER IN GOGEBIC COUNTY. RESULTING WIND CHILL VALUES WILL
FALL BELOW -15 OVER MUCH OF THE CENTRAL AND W...DOWN TO -25 TO -30
IN THE COLDEST SPOTS.
AFTER TUE WE COULD SEE A COUPLE SHORTWAVES MOVES THROUGH BEFORE
THU...WHICH MAY OR MAY NOT PRODUCE ANY WIDESPREAD LIGHT SNOW. THERE
IS ENOUGH UNCERTAINTY AND LACK OF SIGNIFICANT CONDITIONS AFTER TUE
TO JUST RUN WITH A CONSENSUS BLEND FOR THE FORECAST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 107 PM EST SAT JAN 16 2016
AT KIWD/KCMX...NW FLOW LAKE EFFECT CONTINUES THROUGH THE WEEKEND
WITH MVFR CONDITIONS PREVAILING. EXPECT IFR VSBY DURING THE HEAVIER
SNOW BANDS AT IWD BUT MAINLY IFR VSBY AT CMX...BUT THIS WILL BE A
VARIABLE CONDITION.
AT KSAW...MVFR CONDITIONS WILL CONTINUE THROUGH THE FORECAST PERIOD
WITH THE LAKE EFFECT SNOW SHOWERS. HEAVIER SNOW SHOWERS WITH BRIEF
IFR VSBY COULD OCCUR LATE TONIGHT INTO SUN MORNING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 434 PM EST SAT JAN 16 2016
A LOW MOVING FROM SOUTHERN ONTARIO TO QUEBEC WILL BRING COLDER AIR
ACROSS LK SUPERIOR THROUGH THE WEEKEND. BEHIND THE LOW...A TROUGH
WILL REMAIN FAIRLY STATIONARY OVER SOUTHERN LAKE SUPERIOR INTO
TUESDAY...KEEPING WIND GUSTS BETWEEN 25-30KTS. IN ADDITION...THERE
IS THE POTENTIAL FOR HEAVY FREEZING SPRAY SUNDAY INTO MONDAY. WINDS
ARE EXPECTED TO SLOWLY DIMINISH TOWARDS THE MIDDLE OF NEXT WEEK...AS
HIGH PRESSURE MOVES OVER THE UPPER GREAT LAKES REGION.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WARNING UNTIL 1 PM EST SUNDAY FOR MIZ002-003.
LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST SUNDAY FOR MIZ001-084.
WIND CHILL ADVISORY FROM 9 PM THIS EVENING TO NOON CST MONDAY
FOR MIZ009-010.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST MONDAY FOR MIZ007-085.
LAKE EFFECT SNOW WARNING UNTIL 7 PM EST MONDAY FOR MIZ006.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING FROM 7 AM SUNDAY TO 1 PM EST MONDAY
FOR LSZ264>267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
406 PM CST SAT JAN 16 2016
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 331 PM CST SAT JAN 16 2016
COLD AIR CONTINUES TO FILTER INTO THE AREA THIS AFTERNOON AS AN
ARCTIC HIGH CONTINUES TO SINK INTO THE NORTHERN PLAINS FROM THE
CANADIAN PRAIRIES. TEMPERATURES THIS AFTERNOON ARE ALREADY BELOW
ZERO ACROSS MOST OF THE AREA AND WE ARE GOING TO EASILY SETTLE INTO
THE DOUBLE DIGITS BELOW ZERO...WITH THE COLDEST TEMPERATURES STILL
LOOKING TO BOTTOM OUT IN THE -20S BELOW ZERO IN CENTRAL MN. FOR WIND
CHILLS...CONFIDENCE IS HIGH THAT WE WILL SEE WIND CHILLS OF -35 TO
-45 OUTSIDE OF THE TWIN CITIES AND WRN WI...BUT FOR THE TWIN
CITIES/WRN WI...THIS LOOKS TO BE A MORE MARGINAL WARNING...WITH WIND
CHILLS BOTTOMING OUT RIGHT AROUND -35...THANKS MAINLY TO LIGHTER
WINDS THAN WHAT WE WILL SEE FARTHER WEST AND SOUTH. HOWEVER...WITH A
WARNING ALREADY OUT...SEE NO REASON TO CHANGE THE HEADLINE TYPE AT
THIS POINT. WHAT WE DID CHANGE THOUGH WERE THE START TIMES FOR THE
WARNING SO THAT THEY WERE MORE IN LINE WITH WHEN WE ARE ANTICIPATING
WIND CHILL VALUES TO GET DOWN TO -35 OR LESS...THOUGH WE MAY STILL
BE STARTING OFF THE WIND CHILL HEADLINES A LITTLE EARLY.
FOR SUNDAY...CONFIDENCE AGAIN REMAINS HIGH THAT WE WILL SEE HIGH
TEMPERATURES TOPPING OUT BETWEEN 5 AND 10 DEGREES BELOW ZERO AS THE
CORE OF THE ARCTIC AIR SETTLES OVER THE AREA...WHICH IS WHAT THE
ECMWF HAS BEEN ADVERTISING FOR SEVERAL DAYS. THESE COLD TEMPERATURES
ALONG WITH CONTINUED 5 TO 10 MPH WINDS WILL KEEP WIND CHILLS SOLIDLY
IN THE -25 TO -35 RANGE THROUGH THE DAY ON SUNDAY. THESE VALUES WILL
CONTINUE THROUGH SUNDAY NIGHT...SO TACKED ON A WIND CHILL ADVY THAT
BEGINS WHEN THE WARNING ENDS AND GOES THROUGH MONDAY MORNING. PARTS
OF THIS MAY IN THE END NEED TO BE UPGRADED TO A
WARNING...PARTICULARLY IN CENTRAL MN...BUT WANTED TO AT LEAST GET
THE ADVY BEYOND THE WARNING GIVEN THE WIND CHILL VALUES WE ARE
EXPECTING TO SEE THROUGH THE DAY ON SUNDAY.
CONTINUE TO HAVE LOW CONFIDENCE IN THE SKY FORECAST THROUGH THE
PERIOD...WHICH IS TYPICAL FOR COLD AIR MASSES SUCH AS THIS. THOUGH
RH FIELDS WOULD SUGGEST WE SHOULD SEE FAIRLY EXTENSIVE
STRATOCU...WHEN IT GETS THIS COLD...ABOUT ALL YOU END UP WITH IS A
RATHER RATTY AND THIN CLOUD LAYER THAT IS REALLY MORE OF A THIN
CIRRUS DOWN NEAR THE GROUND AS OPPOSED TO A STRATUS TYPE CLOUD. TO
THE EYE...THIS LOOKS LIKE A HAZY CLEAR SKY...SO DID REDUCE SKY COVER
A BIT THROUGH THE SHORT TERM.
FINALLY...THOUGH WINDS ARE NOT TOO CRAZY...WITH MAX SUSTAINED WINDS
TOPPING OUT AT 20 MPH AND GUSTS AROUND 25 MPH...WE HAVE NONE THE
LESS SEEN THEN TELL TALE SIGNS OF BLOWING SNOW IN THE OBS WITH
NUMEROUS AIRPORTS IN WRN THROUGH SRN MN REPORTING 1 TO 5 MILE
VISIBILITIES IN "HAZE"...WHICH IS REALLY BLOWING SNOW. TRAFFIC CAMS
FROM OUT THERE SHOW WE ARE SEEING SOME MINOR BLOWING SNOW AS
WELL...SO DID ADD IN A PATCHY BLOWING SNOW MENTION THROUGH THE REST
OF THE AFTERNOON. TONIGHT...WINDS LOOK TO SETTLE DOWN ENOUGH TO END
WHAT LITTLE BLOWING SNOW WE ARE SEEING.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 400 PM CST SAT JAN 16 2016
MN/WI WILL BE VERY COLD TO START THE WORK WEEK...BUT THERE WILL BE
A GRADUAL MODERATING OF TEMPERATURES THROUGHOUT THE WEEK AND A
CHANCE FOR SOME LIGHT SNOW TUESDAY NIGHT INTO WEDNESDAY.
NORTHWEST FLOW PERSISTS ON MONDAY BUT THE AXIS OF COLDEST AIR
SHIFTS TO THE EAST SUNDAY NIGHT. AT THE SURFACE...AN AREA OF HIGH
PRESSURE WILL MOVE ACROSS THE DAKOTAS AND INTO THE UPPER
MISSISSIPPI RIVER VALLEY DURING THE DAY ON MONDAY. WE SHOULD SEE
LIMITED MIXING...AND GIVEN THE VERY COLD START...MOST LOCATIONS
ACROSS THE FORECAST AREA WILL STRUGGLE TO GET BACK UP ABOVE ZERO
FOR HIGHS ON MONDAY. THIS IS EVEN IF WE END UP WITH SUNSHINE. THE
HIGH HANGS AROUND MONDAY NIGHT INTO TUESDAY MORNING. TUESDAY IS
ANOTHER MORNING TO WATCH FOR STRONG RADIATIONAL COOLING AND TEMPS
THAT END UP -15 TO -20 /COLDER THAN WHAT IS CURRENTLY IN THE
FORECAST./
THE 1000-850MB FLOW BECOMES WEAK MONDAY NIGHT...BUT PICKS UP A
W-SW COMPONENT ON TUESDAY...WHICH WILL LEAD TO A SLIGHT
MODIFICATION OF TEMPS AS WE HEAD TOWARD INTO TUE/WED. THE CHANGE
IN FLOW IS A PRECURSOR TO AN ADVANCING SHORTWAVE THAT WILL MOVE
THROUGH TUESDAY NIGHT. THE OMEGA ISNT OVERLY IMPRESSIVE...BUT
THERE IS A LITTLE BIT OF MOISTURE TO WORK WITH. TUE-WED WILL
FEATURE MOISTURE ADVECTION AND A CHANGE FROM TRUE ARCTIC AIRMASS
PWATS OF 0.05 INCH PRESENTLY IN PLACE TO 0.25-0.30 INCH. THE MAIN
FORCING IS FORECAST TO BE SOUTHWEST OF THE AREA AT THIS TIME...SO
WE WILL STRUGGLE TO GET MUCH MORE OF A DUSTING UNLESS THIS
SHORTWAVE COMES FARTHER NORTH. NE/IA MIGHT END UP WITH AND INCH OR
TWO. TEMPERATURES LOOK TO REMAIN CLOSER TO NORMAL TO CLOSE OUT THE
WEEK AND IT ALSO LOOKS DRY. THE WET WEATHER LATE NEXT WEEK REMAINS
ACROSS THE SOUTHEAST US.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1214 PM CST SAT JAN 16 2016
MAIN CHANGE NEEDED FOR TAFS WAS TO INCLUDE SNOW MENTION FOR MOST
TAFS AS PATCH OF 5K TO 8K FOOT CLOUDS STARTED PRODUCING FAIRLY
WIDESPREAD LIGHT SNOW WEST OF I-35. RAP BUFKIT SOUNDINGS WERE
SHOWING MOST TERMINALS GETTING A FEW HOURS OF VERY LIGHT SNOW...SO
FOLLOWED ITS TIMING FOR PUTTING IN SOME TEMPO MVFR VSBYS WITH -SN.
WILL SEE SKIES CLEAR OUT FOR A TIME THIS AFTERNOON/EVENING...BUT
EXPECT MORE 080-120 TYPE CLOUDS TO DRIFT BACK INTO THE AREA LATE
TONIGHT AS THE UPPER LOW MOVES OVER LAKE SUPERIOR. THESE CLOUDS
CAN BE FOUND THIS AFTERNOON AROUND THE MANITOBA LAKES.
KMSP...BASED ON WHAT HAS BEEN HAPPENING TO OUR WEST...HAVE PRETTY
HIGH CONFIDENCE THAT WE WILL SEE SOME MVFR VIS TYPE SNOWS THROUGH
ABOUT 21Z. NOT ANTICIPATING ANY ACCUMULATIONS...THOUGH VIS
RESTRICTIONS MAY REDUCE ARRIVAL RATES AT TIMES. AFTER THAT...HIGH
CONFIDENCE IN THE REST OF WHAT WILL BE A VERY COLD TAF PERIOD.
/OUTLOOK FOR KMSP/
TUE...VFR. CHANCE -SN/MVFR LATE. WIND SE AROUND 5 KTS.
WED...VFR. CHANCE -SN/MVFR EARLY. WIND S AROUND 5 KTS.
THU...VFR. WIND W AROUND 5 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
WI...WIND CHILL ADVISORY FROM 10 AM SUNDAY TO NOON CST MONDAY FOR
WIZ014>016-023>028.
WIND CHILL WARNING FROM 3 AM TO 10 AM CST SUNDAY FOR WIZ014>016-
023>028.
MN...WIND CHILL WARNING FROM MIDNIGHT TONIGHT TO 10 AM CST SUNDAY FOR
MNZ043-044-049>051-054-056>059-064>067-073>076-082>085-
091>093.
WIND CHILL ADVISORY FROM 10 AM SUNDAY TO NOON CST MONDAY FOR
MNZ043>045-049>054-056>070-073>078-082>085-091>093.
WIND CHILL WARNING UNTIL NOON CST SUNDAY FOR MNZ041-042-047-048-
055.
WIND CHILL ADVISORY UNTIL 6 PM CST THIS EVENING FOR MNZ041-042-
047-048-055.
WIND CHILL ADVISORY FROM NOON SUNDAY TO NOON CST MONDAY FOR
MNZ041-042-047-048-055.
WIND CHILL WARNING FROM 3 AM TO 10 AM CST SUNDAY FOR MNZ045-052-
053-060>063-068>070-077-078.
WIND CHILL ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR MNZ054-056-
064.
&&
$$
SHORT TERM...MPG
LONG TERM...CLF
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1215 PM CST SAT JAN 16 2016
.UPDATE...
ISSUED AT 1214 PM CST SAT JAN 16 2016
BAND OF CLOUDS WORKING ACROSS MN THIS MORNING HAS STARTED TO
PRODUCE FAIRLY WIDESPREAD LIGHT SNOW. NOT SEEING ANY
ACCUMULATIONS...BUT IT IS SNOWING ACROSS A FAIRLY LARGE AREA...SO
UPDATED POP AND WX GRIDS TO BRING A BAND OF LIGHT SNOW ACROSS THE
AREA THIS AFTERNOON.
ALSO MADE SOME CHANGES TO THE WIND CHILL HEADLINES. KEPT THE ADVY
IN PLACE THROUGH THE AFTERNOON IN WRN MN...BUT FOR THE
WARNING...DID DELAY START TIMES QUITE A BIT OUTSIDE OF WEST
CENTRAL MN TO GET START TIMES CLOSER TO WHEN WE WILL SEE WIND
CHILL VALUES AROUND -35. IN ADDITION...WITH WIND CHILL VALUES
FORECAST TO REMAIN BETWEEN -25 AND -35 SUNDAY AFTERNOON THROUGH
MONDAY MORNING...DID TACK ON AN AREA WIDE WIND CHILL ADVY THAT
PICKS UP WHERE THE WARNING LEAVES OFF AND CONTINUES THROUGH MONDAY
MORNING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 327 AM CST SAT JAN 16 2016
THE CORE OF THE COLDEST AIR OF THE SEASON WAS NORTH OF THE
CANADIAN BORDER EARLY THIS MORNING. BANDS OF CLOUDS THAT MOVED
ACROSS THE STATE OVERNIGHT HAVE MODIFIED SOME SFC TEMPS WHICH HAS
LED TO SLIGHTLY WARMER READINGS. THIS HAS ALSO LED TO WIND CHILL
VALUES NOT AS COLD AS THE FORECAST PREVIOUSLY INDICATED AS OF 3
AM. THERE IS ALSO A QUESTION AS TO WHETHER WIND CHILL VALUES
SHOULD BE EXTENDED THRU THE AFTN IN MPX FAR NW CWA.
FIRST...STRONG COLD AIR ADVECTION REMAINS EVIDENT ABV THE BOUNDARY
LAYER THROUGH TODAY/TONIGHT AS THE CORE OF THIS COLD AIR MASS SLIDES
SOUTHWARD ACROSS THE UPPER MIDWEST OVERNIGHT. ALTHOUGH THERE WILL BE
PERIODS OF CLOUDS TODAY/TONIGHT... THE CORE OF THIS COLD AIR MASS
SHOULD BE ENOUGH TO KEEP CURRENT HEADLINES IN PLACE...AND TO ADD A
WIND CHILL WARNING FOR LATER TONIGHT. CURRENT WIND CHILL VALUES IN
WC MN ARE NEAR -25F...WITH WIND CHILL VALUES IN NW MN AROUND -35F.
AS SFC TEMPS CONTINUE TO DROP THROUGH SUNRISE...WIND CHILL VALUES OF
-25F SHOULD SPREAD ACROSS MOST OF CENTRAL/SOUTHERN MN...AND LAST A
FEW HRS BEFORE RECOVERING THIS AFTN. ALTHOUGH WC MN WILL LIKELY
CONTINUE TO SEE -25F WIND CHILL VALUES THRU THE AFTN...THUS LEADING
TO THE EXTENSION OF THE WIND CHILL ADVISORY. DEBATED ON WHEN AND HOW
LONG TO ISSUE A WIND CHILL WARNING /WIND CHILL VALUES -35F OR LOWER/
LATER THIS EVENING/OVERNIGHT AS TEMPS FALL INTO THE TEENS BELOW
ZERO. EVEN A 10 MPH WIND SPEED IS EQUAL TO -35F WIND CHILL VALUE
WHEN TEMPS FALL INTO THE TEENS BELOW ZERO. THESE WIND CHILL VALUES
ARE EXPECTED TO SPREAD SOUTH AND EAST ACROSS MPX CWA DURING THE
EVENING...AND LAST UNTIL AFTER SUNRISE SUNDAY. EVEN A FEW WIND CHILL
VALUES OF -40F ARE POSSIBLE IN CENTRAL MN AS SFC TEMPS FALL TO AROUND
-20F. IN THE PAST...IT IS DIFFICULT TO REACH THESE TYPE OF WIND
CHILL VALUES...ESPECIALLY CONSIDERING THE WARM START THIS WINTER.
HOWEVER...SEVERAL MODELS CONTINUE TO DEPICT WIND CHILL VALUES NEAR
OR BELOW -35F ACROSS CENTRAL/SOUTHERN MN AND INTO WC WI BY SUNDAY
MORNING. THIS AIR MASS MOVING SOUTHWARD IS SERIOUS ENOUGH TO ISSUE A
WIND CHILL WARNING EVEN IF THE WIND CHILL OF -35F ARE ONLY REACHED
FOR AN HR OR TWO.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 327 AM CST SAT JAN 16 2016
DANGEROUSLY COLD TEMPS CONTINUE INTO THE START OF THE LONG TERM
PERIOD...BUT THEN WE CONTINUE TO SEE A WARM-UP THROUGH THE WEEK.
SUNDAY MORNING WILL LIKELY BE THE PEAK OF THE BITTERLY COLD WIND
CHILL TEMPS...BUT IMPROVEMENT WILL OCCUR THROUGH THE DAY PRIMARILY
DUE TO THE FACT THAT WINDS WILL BE DECREASING. SUB-ZERO HIGH TEMPS
WILL BE FOUND AREA-WIDE.
SUNDAY NIGHT LOWS WILL LIKELY BE JUST AS COLD AS SATURDAY
NIGHT...BUT WINDS WILL BE ABOUT 5 KTS LIGHTER. THEREFORE A WIND
CHILL ADVISORY WILL PROBABLY SUFFICE FOR MOST OF THE AREA ON
SUNDAY NIGHT INTO MONDAY MORNING...WITH POSSIBLY THE EXCEPTION OF
WEST CENTRAL MN /NEAR ALEXANDRIA/ WHERE NEAR -35 FORECAST VALUES
MAY NECESSITATE A WARNING.
WHILE THE HIGH PRESSURE WILL STILL BE WELL IN PLACE ON MONDAY...A
BIT MORE SUNSHINE AND A FAVORABLE WESTERLY COMPONENT TO THE WIND
FIELD SHOULD HELP TEMPS WARM NEAR TO SLIGHTLY ABOVE ZERO IN ALL
BUT POSSIBLY AREAS NEAR ALEXANDRIA.
MONDAY NIGHT...WHILE STILL SEEING LOW TEMPS IN THE DOUBLE DIGITS
BELOW ZERO /-10 TO -15/...WIND SPEEDS WILL BE NOTABLY LOWER.
THEREFORE THE NEED FOR AN ADVISORY INTO TUESDAY MORNING LOOKS
UNLIKELY AT THIS POINT.
TUESDAY AND TUESDAY NIGHT STILL LOOK TO BE THE ONLY OPPORTUNITY
FOR SNOWFALL..AS A WEAK SHORTWAVE MOVES OVER THE AREA. HAVE
INCLUDED 30-40 PERCENT POPS FOR THIS FEATURE BUT LIMITED MOISTURE
AND A SOMEWHAT SHORT WINDOW FOR LIFT LOOK TO LIMIT THE POTENTIAL
FOR ANYTHING MORE THAN MINOR SNOWFALL ACCUMULATIONS.
THE LAST HALF OF THE WEEK BRINGS A GRADUAL MODERATION IN
TEMPERATURES AS THE ARCTIC HIGH SLIDES SOUTHEAST OF THE AREA. HIGH
TEMPS WILL WARM A FEW DEGREES EACH DAY...WITH ABOVE NORMAL HIGH
TEMPERATURES IN THE 25-30 DEGREE RANGE EXPECTED BY FRIDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1214 PM CST SAT JAN 16 2016
MAIN CHANGE NEEDED FOR TAFS WAS TO INCLUDE SNOW MENTION FOR MOST
TAFS AS PATCH OF 5K TO 8K FOOT CLOUDS STARTED PRODUCING FAIRLY
WIDESPREAD LIGHT SNOW WEST OF I-35. RAP BUFKIT SOUNDINGS WERE
SHOWING MOST TERMINALS GETTING A FEW HOURS OF VERY LIGHT SNOW...SO
FOLLOWED ITS TIMING FOR PUTTING IN SOME TEMPO MVFR VSBYS WITH -SN.
WILL SEE SKIES CLEAR OUT FOR A TIME THIS AFTERNOON/EVENING...BUT
EXPECT MORE 080-120 TYPE CLOUDS TO DRIFT BACK INTO THE AREA LATE
TONIGHT AS THE UPPER LOW MOVES OVER LAKE SUPERIOR. THESE CLOUDS
CAN BE FOUND THIS AFTERNOON AROUND THE MANITOBA LAKES.
KMSP...BASED ON WHAT HAS BEEN HAPPENING TO OUR WEST...HAVE PRETTY
HIGH CONFIDENCE THAT WE WILL SEE SOME MVFR VIS TYPE SNOWS THROUGH
ABOUT 21Z. NOT ANTICIPATING ANY ACCUMULATIONS...THOUGH VIS
RESTRICTIONS MAY REDUCE ARRIVAL RATES AT TIMES. AFTER THAT...HIGH
CONFIDENCE IN THE REST OF WHAT WILL BE A VERY COLD TAF PERIOD.
/OUTLOOK FOR KMSP/
TUE...VFR. CHANCE -SN/MVFR LATE. WIND SE AROUND 5 KTS.
WED...VFR. CHANCE -SN/MVFR EARLY. WIND S AROUND 5 KTS.
THU...VFR. WIND W AROUND 5 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
WI...WIND CHILL ADVISORY FROM 10 AM SUNDAY TO NOON CST MONDAY FOR
WIZ014>016-023>028.
WIND CHILL WARNING FROM 3 AM TO 10 AM CST SUNDAY FOR WIZ014>016-
023>028.
MN...WIND CHILL WARNING FROM MIDNIGHT TONIGHT TO 10 AM CST SUNDAY FOR
MNZ043-044-049>051-054-056>059-064>067-073>076-082>085-
091>093.
WIND CHILL ADVISORY UNTIL NOON CST TODAY FOR MNZ043>045-049>052-
057>059-065>069-073>077-082>085-091>093.
WIND CHILL ADVISORY FROM 10 AM SUNDAY TO NOON CST MONDAY FOR
MNZ043>045-049>054-056>070-073>078-082>085-091>093.
WIND CHILL WARNING FROM 6 PM THIS EVENING TO NOON CST SUNDAY FOR
MNZ041-042-047-048-055.
WIND CHILL ADVISORY UNTIL 6 PM CST THIS EVENING FOR MNZ041-042-
047-048-055.
WIND CHILL ADVISORY FROM NOON SUNDAY TO NOON CST MONDAY FOR
MNZ041-042-047-048-055.
WIND CHILL WARNING FROM 3 AM TO 10 AM CST SUNDAY FOR MNZ045-052-
053-060>063-068>070-077-078.
WIND CHILL ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR MNZ054-056-
064.
&&
$$
UPDATE...MPG
SHORT TERM...JLT
LONG TERM...LS
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS Tulsa OK
1127 AM CST SAT JAN 16 2016
.DISCUSSION...
The 18Z TAF discussion is included below.
&&
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
No weather impacts to aviation are expected this TAF period. Mid
and high cloud will have cigs well into the VFR range. Precip will
remain south of the TAF sites as well.
Lacy
&&
.PREV DISCUSSION... /ISSUED 721 AM CST SAT JAN 16 2016/
DISCUSSION...
A west to east oriented band of precip is showing up nicely on
radar mosaic this morning across southern OK...forced by
frontogenesis around 700mb. The band is more intense on the
western flank...due to a more optimal combination of
frontogenetic and QG forcing with the approaching wave. This
better forcing will track from southwest OK down into northeast
TX today as the band pivots in a more WSW-ENE orientation and
slides south and east with time. Thus...the eastern flank of the
precip band will likely be of lighter intensity compared to points
west. Surface temperatures remain above freezing beneath the
band...though wet-bulbing will allow for some snow to reach the
surface if the precip falls heavy enough...especially in the
higher terrain. The ridge tops indeed stand the best chance of
seeing any accumulation. Will maintain less than 1 inch amounts
mainly in the higher terrain of SE OK...with the latest RAP QPF
showing .1" amounts at most from this event. Will hold off on any
headlines for now...with impacts to roads still not looking likely
with the marginal surface temps. Will continue to monitor.
Lacy
PREV DISCUSSION... /ISSUED 541 AM CST SAT JAN 16 2016/
AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
Area of precipitation continues to expand across southwestern and
south central Oklahoma and expect this to continue spreading into
southeastern Oklahoma this morning. Temperature profiles support a
rain and snow mixture at MLC. Cigs at that location should lower to
4-6k feet and visibility may reach MVFR category if precipitation is
heavy enough. VFR cigs with extensive mid/high level clouds other
TAF sites with skies clearing from west to east late this afternoon
and evening.
PREV DISCUSSION... /ISSUED 356 AM CST SAT JAN 16 2016/
DISCUSSION...
Radar trends over the past hour or two show a band of enhanced
reflectivity setting up just south of I40 in western Ok with light
snow now being reported at Chickasha. Over the next few hours
this will expand into parts of southeast OK...HRRR remains fairly
consistent with main precip band this morning focusing south of a
McAlester to Poteau line. First period pops will lean heavily on
this and radar trends at issuance time.
Temps profiles remain quite marginal for accumulating snow outside
of heaviest precip band...where the column should be cooled enough
due to wet-bulb effects for change to all snow. Would also expect
snow to be dominant precip type much of the day in the higher
elevations of southeast OK. Still possible that a very narrow
corridor could experience a period of moderate snowfall which
could accumulate quickly on grassy/elevated surfaces...perhaps an
inch or so...but right now this looks to be a low impact event and
will hold off on any advisory.
Wave responsible for the rain/snow will move out this afternoon
with a period of clearing skies through early sunday. Strong push
of colder air will arrive Sunday afternoon and evening...perhaps
accompanied by flurries or very light snow. Slightly better
chance of accumulating snow across northwest AR Sunday night as
some weak shortwave energy present. Much colder temps by Monday
morning with wind chills near or even below zero in some areas
near the KS border.
Still a great deal of uncertainty in next weeks forecast as the
pattern remains somewhat unsettled. Potential mid week systems
continue to be handled poorly by mid range models. Overall winter
weather threat looks limited at this time as temps quickly
moderate after Monday.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 43 25 36 11 / 10 0 10 10
FSM 46 26 46 25 / 10 0 10 20
MLC 43 25 46 18 / 30 0 10 10
BVO 41 18 30 10 / 10 0 10 10
FYV 42 20 42 12 / 10 0 10 20
BYV 40 23 37 10 / 0 0 10 20
MKO 43 25 41 15 / 10 0 10 10
MIO 40 21 30 7 / 0 0 10 10
F10 42 27 41 15 / 20 0 10 10
HHW 45 25 49 27 / 70 10 10 10
&&
.TSA Watches/Warnings/Advisories...
OK...NONE.
AR...NONE.
&&
$$
AVIATION...30
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
325 PM EST SAT JAN 16 2016
.SHORT TERM (TONIGHT AND TOMORROW)...
THE FOCUS FOR THE SHORT-TERM FORECAST WILL BE ON THE LOW JUST OFF
THE TEXAS COAST AS IT WILL BRING THE POTENTIAL FOR SNOW TO MOVE
INTO THE MOUNTAINS LATER TONIGHT. CURRENT WATER VAPOR AND RAP UPPER
AIR ANALYSIS INDICATES A TROUGH ALONG THE NORTHWESTERN GULF OF
MEXICO. ANOTHER WEAK WAVE IS MOVING ACROSS CENTRAL TEXAS AND THE
RAP INDICATES THAT THESE TWO PIECES OF ENERGY WILL PARTIALLY PHASE
ACROSS THE NORTHERN GULF COAST WITH THE SURFACE LOW DEEPENING
BELOW 1000 MB. WITH THIS SYSTEM STILL LESS THAN 12-24 HOURS
OUT...THERE ARE STILL SEVERAL DETAILS TO WORK OUT. THE NAM KEEPS
THE LOW WELL SOUTH ACROSS THE FLORIDA PENINSULA WITH A LIMITED
AMOUNT OF MOISTURE MOVING INTO THE EAST TENNESSEE MOUNTAINS. THE
GFS IS THE MOST ROBUST WITH THE SYSTEM MOVING ACROSS THE BIG BEND
AREA OF FLORIDA WITH ENOUGH MOISTURE FOR A COUPLE OF INCHES OF SNOW
ACROSS THE MOUNTAINS. REGARDLESS...THE NAM DOES SHOW SIMILAR PW
VALUES TO THE GFS JUST NOT AS MUCH LIFT DUE TO THE LOW TRACK. THE
09Z SREF WAS IMPRESSIVE WITH SOME OF THE MEMBERS SHOWING AS MUCH AS
2 INCHES OF SNOW IN THE VALLEY BUT LOOKING AT THE 15Z SREF IT
APPEARS THE NUMBERS HAVE DECREASED A GOOD BIT.
THE MAIN CHALLENGE FOR THE FORECAST WILL BE HOW FAR NORTHWEST WILL
THE NORTHERN BAND OF PRECIPITATION BE. MOST OF THE 12Z GUIDANCE
SUGGESTED THIS WOULD BE ALONG THE SOUTHERN APPALACHIANS.
TEMPERATURES SHOULD NOT BE AN ISSUE WITH THE ATMOSPHERE BELOW
FREEZING BEFORE THE MOISTURE ARRIVES. MOISTURE AND LIFT LOOKS TO
BE HIGH ENOUGH TO SQUEEZE OUT AN INCH TO POSSIBLY 2 INCHES OF SNOW
ACROSS THE HIGHER TERRAIN. SINCE THIS IS THE FIRST REAL SNOWFALL
THREAT OF THE SEASON...DECIDED TO GO AHEAD AND ISSUE AND ADVISORY
FOR THE ZONES ALONG THE TENNESSEE/NORTH CAROLINA LINE. SNOW WILL
BEGIN TO TAPER OFF ACROSS THE HIGHER ELEVATIONS TOMORROW AFTERNOON.
.LONG TERM (SUNDAY NIGHT THROUGH SATURDAY)...
AN ARCTIC BOUNDARY WILL MOVE SOUTH ACROSS THE AREA SUNDAY NIGHT.
FLURRIES OR SNOW SHOWERS (MOUNTAINS) CAN BE EXPECTED WITH ONLY
MINOR ACCUMULATIONS ACROSS THE HIGHER TERRAIN.
FOR MONDAY AND TUESDAY...ARCTIC RIDGE AND DRY NORTHWEST FLOW WILL
DOMINATE THE PATTERN PRODUCING MOSTLY CLEAR AND VERY COLD
NIGHT-TIME TEMPERATURES.
FOR WEDNESDAY...MODELS SHOW A WEAKENING SHORT-WAVE IN THE NORTHWEST
FLOW MOVING ACROSS THE TENNESSEE VALLEY. ISENTROPIC LIFT AND JET
DYNAMICS WILL PRODUCE A SWATH OF LIGHT SNOW ACROSS THE TENNESSEE
VALLEY INTO THE SOUTHERN APPALACHIANS. A BAND OF 1 TO 3 INCHES OF
SNOW ACCUMULATIONS IS POSSIBLE. A MIXTURE OF SNOW..SLEET..AND RAIN
IS ALSO ANTICIPATED NEAR THE TENNESSEE/GEORGIA STATE-LINE.
FOR THURSDAY AND FRIDAY...UPPER RIDGING AND ARCTIC HIGH EAST OF THE
AREA WILL ALLOW FOR MODERATION OF TEMPERATURES AHEAD OF NEXT
STRONGER UPPER TROUGH FOR THURSDAY NIGHT AND FRIDAY. CURRENT MEDIUM
RANGE MODELS SHOW A MIXED BAG OF WINTRY WEATHER ACROSS THE TENNESSEE
VALLEY AND SOUTHERN APPALACHIANS. DEPENDING ON EXACT PATH OF
SURFACE/850MB LOW WILL DETERMINE PRECIPITATION TYPE. THIS IS THE
STRONGEST SYSTEM DURING THE EXTENDED AND HAS THE POTENTIAL OF
PRODUCING MORE SIGNIFICANT SNOWS. WILL HIGHLIGHT IN THE HWO.
FOR SATURDAY...WRAP-AROUND MOISTURE AND COLDER WILL BE PULLED ACROSS
THE AREA WITH SNOW/RAIN SHOWERS ANTICIPATED.
&&
.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN 32 43 23 34 / 20 10 10 0
KNOXVILLE MCGHEE TYSON AIRPORT, TN 31 38 19 29 / 30 20 10 0
OAK RIDGE, TN 31 40 19 30 / 20 10 10 0
TRI CITIES AIRPORT, TN 30 39 18 27 / 50 50 10 0
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...WINTER WEATHER ADVISORY FROM 2 AM TO NOON EST SUNDAY FOR
CHEROKEE-CLAY.
TN...WINTER WEATHER ADVISORY FROM 2 AM TO NOON EST SUNDAY FOR BLOUNT
SMOKY MOUNTAINS-COCKE SMOKY MOUNTAINS-EAST POLK-JOHNSON-
SEVIER SMOKY MOUNTAINS-SOUTHEAST CARTER-SOUTHEAST GREENE-
SOUTHEAST MONROE-UNICOI.
VA...NONE.
&&
$$
MA/DH
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1131 AM CST SAT JAN 16 2016
.AVIATION...
LOW CIGS WILL HANG AROUND THE AREA THROUGH THE LATE AFTERNOON WITH
ABUNDANT LOW LEVEL MOISTURE IN PLACE. ALTHOUGH...CIGS WILL LIKELY
IMPROVE TO MVFR THIS AFTERNOON IF NOT THERE ALREADY. WINDS WILL
EVENTUALLY SWING AROUND TO THE SOUTH AND SOUTHWEST LATE THIS
AFTERNOON INTO EARLY EVENING SCOURING OUT LOW LEVEL MOISTURE AND
LOW CIGS. VERY LIGHT WINTRY PRECIPITATION WILL COME TO AN END
EARLY THIS AFTERNOON AS AN UPPER LEVEL DISTURBANCE MOVES EAST OF
THE REGION.
&&
.PREV DISCUSSION... /ISSUED 521 AM CST SAT JAN 16 2016/
AVIATION...
-RA INTERMITTENTLY OCCURRING AT KCDS EARLY THIS MORNING AND COULD
CHANGE OVER TO -SN OR -RASN IF TEMPERATURES FALL TO/SLIGHTLY BELOW
FREEZING LATER THIS MORNING. LATEST RADAR ANALYSIS SHOWED SOME
LIGHT ECHOES HAVE DEVELOPED SOUTH OF KPVW. FURTHER DEVELOPMENT IS
POSSIBLE SO HAVE INSERTED A -RASN THERE GIVEN TEMPERATURES ARE
ONLY 1 DEGREE AWAY FROM FREEZING. CONFIDENCE OF PRECIPITATION
NEARING KLBB IS LOW BUT NOT OUT OF THE QUESTION...HOWEVER WILL
ELECT NOT TO INSERT A MENTION AT THIS TIME. WILL OF COURSE AMEND
AS NECESSARY. VFR DECKS ARE EXPECTED TO DETERIORATE TO IFR
CRITERIA LATER THIS MORNING BUT IMPROVE TO VFR BY THE AFTN.
CONCURRENTLY...PRECIPITATION WILL BE EXITING KCDS. SLIGHTLY BREEZY
NORTH TO NORTHEAST WINDS WILL VEER TO THE SOUTHWEST BY LATE
AFTN/EARLY EVENING.
PREV DISCUSSION... /ISSUED 256 AM CST SAT JAN 16 2016/
SHORT TERM...
AS ADVERTISED AN UA SHORTWAVE TROUGH STRETCHED FROM THE PANHANDLES
REGION SW TO ACROSS NERN OLD MEXICO...CONTINUED TO APPROACH THE
REGION EARLY THIS MORNING. AS A RESULT...FLOW ALOFT HAS BACKED
SLIGHTLY TO THE W-SW THUS CAUSING MID-UPPER LEVELS TO GRADUALLY
MOISTEN. AT THE SFC...DEWPOINTS HAVE RISEN INTO THE 20S ON THE
CAPROCK AND 30S OFF THE CAPROCK...WHICH IS SOME 10-20 DEGREES
HIGHER THAN IT WAS THIS TIME YESTERDAY MORNING. A SFC LOW ACROSS THE
FA WAS DRAGGING IN A COLD FRONT THAT HAS CLEARED ALL BUT PORTIONS OF
THE SRN ZONES PER 08Z METARS. WIND SPEEDS HAVE PICKED UP A BIT /8-12
MPH/ AND MAY INCREASE A BIT MORE THROUGHOUT THE MORNING DUE TO
PRESSURE RISES ON THE ORDER OF 4-5 MB/3 HRS... BUT WILL DROP OFF BY
LATE AFTN. WITH UPPER LEVEL DIFFLUENCE SPREADING ACROSS THE REGION
COURTESY OF THE APPROACHING DISTURBANCE...AND COUPLED WITH
FRONTOGENETICAL FORCING HAS PROMOTED A BIT OF BLOSSOMING OF THE
REFLECTIVITY FIELD PARTICULARLY ACROSS THE SERN TX PANHANDLE...NRN
SOUTH PLAINS AND NRN ROLLING PLAINS. PHONE CALLS MADE TO EMERGENCY
PERSONNEL HAVE RESULTED IN REPORTS OF A LIGHT MIST OR NOTHING AT
ALL...WHICH SUGGESTS THAT THE WET-BULBING PROCESS STILL HAS A WAYS
TO GO. WITH TEMPS ABOVE FREEZING THUS FAR...ANYTHING THAT FALLS WILL
LIKELY BE LIQUID FOR NOW...BUT AS SUGGESTED BY MODEL SOLUTIONS...A
TRANSITION TO SNOW OR A RAIN AND SNOW MIX IS STILL ANTICIPATED WITH
TEMPS GRADUALLY FALLING TOWARD DAYBREAK. SNOW ACCUMULATIONS AOA 1
INCH IS STILL PLAUSIBLE ACROSS THE FAR SRN TX PANHANDLE AND NRN
ROLLING PLAINS WITH MUCH LIGHTER AMOUNTS SOUTH AND WEST.
HENCE...WILL CONTINUE TO HOLD OFF ON THE ISSUANCE OF A WINTER
WEATHER ADVISORY...HOWEVER MOTORISTS ARE STILL URGED TO USE CAUTION
AS BRIDGES AND OVERPASS COULD BECOME SLICK DURING THE MORNING HOURS.
THROUGHOUT THIS PROCESS...THE HRRR SUGGESTS THE DEVELOPMENT OF A
STRATUS DECK AND PERHAPS PATCHY FOG AROUND DAYBREAK...COINCIDING
WITH THE LOCATION OF THE PRECIP. BY MID-LATE MORNING...THE PRECIP
WILL BE TRANSITIONING BACK TO LIQUID AS TEMPS RETURN TO ABOVE
FREEZING...WHILST IT ALSO COMMENCES TO PUSH EAST ACROSS THE ROLLING
PLAINS AS THE UA SHORTWAVE TROUGH AND ASSOCIATED UL SUPPORT EXITS
THE REGION TOWARD E TX. CLOUDS WILL BE SLOW TO SCOUR OUT FROM WEST
TO EAST...BUT WILL LIKELY SEE THE SUN BY LATE AFTN/EARLY EVENING
BEFORE SUNSET. TEMPS WILL BE COOLER TODAY /40S/ THANKS TO THE CLOUD
COVER AND COLD FRONT USHERING IN A COOLER AIRMASS. TONIGHT...WEAK
SFC LEE TROUGHING WILL RETURN SFC WINDS TO A SRLY FLOW...WHILST NW
FLOW ALOFT FILTERS IN SOME HIGH-LEVEL CLOUDINESS. THE CLOUD COVER
WILL DISCOURAGE TEMPS FROM CRATERING BUT IT WILL STILL BY ON THE
CHILLY SIDE /UPPER 20S TO LOWER 30S/.
LONG TERM...
00Z MODEL SUITE HAS CONTINUED THE TREND TOWARD DRIER...IE LESS
PRECIP CHANCE...THROUGH NEXT WEEK. A LOW-AMPLITUDE PROGRESSIVE
UPPER PATTERN TO PREVAIL THROUGH AT LEAST MIDWEEK. THE NEXT TWO
SHORT WAVE TROUGHS LOOK EVEN MORE BENIGN THAN BEFORE WITH ONLY
WEAK FRONTAL PASSAGES TO ACCOMPANY THEM. HAVE KEPT TUESDAY DRY
WITH ITS UPPER TROUGH...AND HAVE NOW REMOVED PRECIP MENTION FROM
MIDWEEK. A MILD ROLLER COASTER RIDE REGARDING TEMPS WITH THE
FRONTAL PASSAGES. SOME AMPLIFICATION OF THE FLOW PROGGED LATE NEXT
WEEK WITH AN UPPER RIDGE MIGRATING TOWARD THE PLAINS TO RESULT IN
MORE QUIET WEATHER LIKELY A WARM-UP HEADING INTO NEXT WEEKEND.
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
01