Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 01/22/16
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1045 AM MST WED JAN 20 2016
.UPDATE...
ISSUED AT 929 AM MST WED JAN 20 2016
12Z NAM AND LATEST HRRR HAVE COME IN WITH HEAVIER SNOW OVER THE
CENTRAL MOUNTAINS TODAY AND TONIGHT...WITH UP TO 8 INCHES OVER
HIGHER WEST FACING SLOPES OF THE SAWATCH RANGE AND A FEW POCKETS
OF 6 OVER THE NORTHERN LA GARITAS. WILL THUS HOIST A WINTER
WEATHER ADVISORY FOR THESE AREAS FOR TODAY INTO THIS EVENING.
OUTSIDE OF THE ADVISORY AREAS...HAVE BOOSTED POPS AND SNOW AMOUNTS
SLIGHTLY AROUND LEADVILLE...WHILE KEEPING FORECAST FOR AREAS
FARTHER EAST UNCHANGED.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 425 AM MST WED JAN 20 2016
ONE DISTURBANCE WILL BE MOVING ACRS THE AREA THIS MORNING...WITH
ANOTHER ONE ENTERING WRN CO AROUND MIDDAY AND MOVING ACRS THE AREA
THROUGH TONIGHT.
THE FIRST DISTURBANCE WL BRING SOME SNOW TO THE CONTDVD THIS
MORNING...WITH A LULL IN ACTIVITY BY LATE MORNING AND EARLY
AFTERNOON. THEN AS THE NEXT DISTURBANCE APPROACHES THIS AFTERNOON
AND THEN MOVES ACRS THE AREA TONIGHT...THE SNOW WL INCREASE AGAIN
ALONG THE CONTDVD. SOME OF THE ERN MTNS COULD SEE SOME LIGHT SNOW
THIS MORNING ASSOCIATED WITH THIS FIRST DISTURBANCE...BUT THE SERN
PLAINS IS EXPECTED TO BE DRY.
TONIGHT...AS THE NEXT DISTURBANCE MOVES ACRS THE AREA...THERE WL
PROBABLY BE THE CHANCE FOR SOME LIGHT SNOW ACRS THE SAN LUIS VALLEY
FOR A FEW HOURS...AND ACRS THE ERN MTNS. THE CHANCE FOR PCPN WL
THEN SPREAD TO THE SERN PLAINS. OVERNIGHT...PCPN CHANCES ARE
EXPECTED TO DECREASE OR END FROM NW TO SE ACRS THE FORECAST AREA AS
THE DISTURBANCE MOVES SOUTHEASTWARD ACRS THE AREA. HOWEVER...
FAVORABLE NWRLY FLOW WL PROBABLY KEEP SOME LIGHT SNOW GOING OVR THE
CENTRAL MTNS.
MOST OF THE MTNS AREA TONIGHT WL JUST SEE SOME LIGHT
ACCUMULATIONS...HOWEVER THE CENTRAL MTNS WL PROBABLY SEE UP TO SIX
INCHES OF ACCUMULATION...WITH THE HIGHEST AMOUNTS MAINLY BEING NORTH
OF COTTONWOOD PASS.
WITH THE FRONT EXPECTED TO HOLD OFF MOVING INTO THE SERN PLAINS
UNTIL THIS EVENING...THE WESTERLY FLOW AND MIXING TODAY SHOULD WARM
TEMPS INTO THE UPPER 40S TO LOWER 50S ACRS THE SERN PLAINS WHICH IS
ABOVE AVERAGE.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 425 AM MST WED JAN 20 2016
NOT MANY METEOROLOGICAL ADJUSTMENTS NEEDED DURING THE LONGER TERM
WITH PRIMARY METEOROLOGICAL CONCERNS BEING TEMPERATURES...POPS AND
GUSTY WINDS AT TIMES.
INITIAL DISTURBANCE IS EXPECTED TO BE DEPARTING THE FORECAST
DISTRICT THURSDAY...ALLOWING FOR ISOLATED SHOWER POTENTIAL OVER
EASTERN SECTIONS AND THE CENTRAL MOUNTAINS...PRIMARILY DURING THE
MORNING HOURS. IN ADDITION...GUSTY WINDS ARE ANTICIPATED OVER
SEVERAL LOCATIONS FROM THURSDAY INTO THURSDAY NIGHT AS THE SYSTEM
PULLS EAST OF THE CWA.
A DRY UPPER RIDGING TO ZONAL/SOUTHWESTERLY UPPER PATTERN IS STILL
EXPECTED TO DEVELOP OVER THE FORECAST DISTRICT FROM THURSDAY NIGHT
INTO SATURDAY...ALLOWING FOR GENERALLY DRY AND WARMER CONDITIONS
IN COMBINATION WITH GUSTY WINDS AT TIMES.
NEXT UPPER DISTURBANCE IN COMBINATION WITH NORTH TO NORTHEASTERLY
SURFACE SURGES ARE STILL EXPECTED TO IMPACT THE FORECAST DISTRICT
FROM LATER THIS WEEKEND INTO EARLY NEXT WEEK ALLOWING FOR A RETURN
OF COOLER CONDITIONS AND INCREASED PRECIPITATION CHANCES. AT THIS
TIME...IT APPEARS THAT LOCATIONS SUCH AS THE I-25 CORRIDOR AND
PORTIONS OF THE EASTERN PLAINS WILL HAVE THE HIGHEST POTENTIAL OF
RECEIVING MEASURABLE PRECIPITATION DURING THE LATER MONDAY INTO
TUESDAY TIME-FRAME.
WARMEST TEMPERATURES DURING THE LONGER TERM SHOULD BE NOTED
SATURDAY...WITH COOLEST READINGS EXPECTED THURSDAY AND THEN AGAIN
BY NEXT MONDAY AND TUESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1037 AM MST WED JAN 20 2016
AT KALS...WEB CAMS SUGGEST BRIEF PERIOD OF FOG BEGINNING TO
DISSIPATE ALREADY...AND WILL KEEP ONLY TEMPO IFR CONDITIONS 18Z-
19Z BEFORE CIGS/VIS BECOME VFR AGAIN. FOR THE AFTERNOON AND
TONIGHT...PREVAILING CONDITIONS WILL BE VFR...BUT WILL CARRY A
VCSH MENTION INTO THE EVENING AS A FEW -SHSN MOVE OFF THE HIGHER
TERRAIN AND ACROSS THE VALLEY.
AT KCOS AND KPUB...VFR CONDITIONS TODAY AND TONIGHT...BUT WILL
CARRY A VCSH MENTION INTO THE EVENING AS A FEW -SHSN DEVELOP AS
UPPER TROUGH MOVES OVER THE REGION.
MOUNTAINS...ESPECIALLY ALONG THE CONTINENTAL DIVIDE...WILL SEE A
PERIOD OF IFR/LIFR CIGS/VIS IN SNOW DEVELOP THIS AFTERNOON AND
CONTINUE THROUGH THE EVENING. SOME SLOW CLEARING THEN AFTER 06Z-
08Z...ESPECIALLY FROM KMYP SOUTHWARD.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL MIDNIGHT MST TONIGHT FOR COZ058-
060-066.
&&
$$
UPDATE...PETERSEN
AVIATION...PETERSEN
AREA FORECAST DISCUSSION
NWS PUEBLO CO
936 AM MST WED JAN 20 2016
.UPDATE...
ISSUED AT 929 AM MST WED JAN 20 2016
12Z NAM AND LATEST HRRR HAVE COME IN WITH HEAVIER SNOW OVER THE
CENTRAL MOUNTAINS TODAY AND TONIGHT...WITH UP TO 8 INCHES OVER
HIGHER WEST FACING SLOPES OF THE SAWATCH RANGE AND A FEW POCKETS
OF 6 OVER THE NORTHERN LA GARITAS. WILL THUS HOIST A WINTER
WEATHER ADVISORY FOR THESE AREAS FOR TODAY INTO THIS EVENING.
OUTSIDE OF THE ADVISORY AREAS...HAVE BOOSTED POPS AND SNOW AMOUNTS
SLIGHTLY AROUND LEADVILLE...WHILE KEEPING FORECAST FOR AREAS
FARTHER EAST UNCHANGED.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 425 AM MST WED JAN 20 2016
ONE DISTURBANCE WILL BE MOVING ACRS THE AREA THIS MORNING...WITH
ANOTHER ONE ENTERING WRN CO AROUND MIDDAY AND MOVING ACRS THE AREA
THROUGH TONIGHT.
THE FIRST DISTURBANCE WL BRING SOME SNOW TO THE CONTDVD THIS
MORNING...WITH A LULL IN ACTIVITY BY LATE MORNING AND EARLY
AFTERNOON. THEN AS THE NEXT DISTURBANCE APPROACHES THIS AFTERNOON
AND THEN MOVES ACRS THE AREA TONIGHT...THE SNOW WL INCREASE AGAIN
ALONG THE CONTDVD. SOME OF THE ERN MTNS COULD SEE SOME LIGHT SNOW
THIS MORNING ASSOCIATED WITH THIS FIRST DISTURBANCE...BUT THE SERN
PLAINS IS EXPECTED TO BE DRY.
TONIGHT...AS THE NEXT DISTURBANCE MOVES ACRS THE AREA...THERE WL
PROBABLY BE THE CHANCE FOR SOME LIGHT SNOW ACRS THE SAN LUIS VALLEY
FOR A FEW HOURS...AND ACRS THE ERN MTNS. THE CHANCE FOR PCPN WL
THEN SPREAD TO THE SERN PLAINS. OVERNIGHT...PCPN CHANCES ARE
EXPECTED TO DECREASE OR END FROM NW TO SE ACRS THE FORECAST AREA AS
THE DISTURBANCE MOVES SOUTHEASTWARD ACRS THE AREA. HOWEVER...
FAVORABLE NWRLY FLOW WL PROBABLY KEEP SOME LIGHT SNOW GOING OVR THE
CENTRAL MTNS.
MOST OF THE MTNS AREA TONIGHT WL JUST SEE SOME LIGHT
ACCUMULATIONS...HOWEVER THE CENTRAL MTNS WL PROBABLY SEE UP TO SIX
INCHES OF ACCUMULATION...WITH THE HIGHEST AMOUNTS MAINLY BEING NORTH
OF COTTONWOOD PASS.
WITH THE FRONT EXPECTED TO HOLD OFF MOVING INTO THE SERN PLAINS
UNTIL THIS EVENING...THE WESTERLY FLOW AND MIXING TODAY SHOULD WARM
TEMPS INTO THE UPPER 40S TO LOWER 50S ACRS THE SERN PLAINS WHICH IS
ABOVE AVERAGE.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 425 AM MST WED JAN 20 2016
NOT MANY METEOROLOGICAL ADJUSTMENTS NEEDED DURING THE LONGER TERM
WITH PRIMARY METEOROLOGICAL CONCERNS BEING TEMPERATURES...POPS AND
GUSTY WINDS AT TIMES.
INITIAL DISTURBANCE IS EXPECTED TO BE DEPARTING THE FORECAST
DISTRICT THURSDAY...ALLOWING FOR ISOLATED SHOWER POTENTIAL OVER
EASTERN SECTIONS AND THE CENTRAL MOUNTAINS...PRIMARILY DURING THE
MORNING HOURS. IN ADDITION...GUSTY WINDS ARE ANTICIPATED OVER
SEVERAL LOCATIONS FROM THURSDAY INTO THURSDAY NIGHT AS THE SYSTEM
PULLS EAST OF THE CWA.
A DRY UPPER RIDGING TO ZONAL/SOUTHWESTERLY UPPER PATTERN IS STILL
EXPECTED TO DEVELOP OVER THE FORECAST DISTRICT FROM THURSDAY NIGHT
INTO SATURDAY...ALLOWING FOR GENERALLY DRY AND WARMER CONDITIONS
IN COMBINATION WITH GUSTY WINDS AT TIMES.
NEXT UPPER DISTURBANCE IN COMBINATION WITH NORTH TO NORTHEASTERLY
SURFACE SURGES ARE STILL EXPECTED TO IMPACT THE FORECAST DISTRICT
FROM LATER THIS WEEKEND INTO EARLY NEXT WEEK ALLOWING FOR A RETURN
OF COOLER CONDITIONS AND INCREASED PRECIPITATION CHANCES. AT THIS
TIME...IT APPEARS THAT LOCATIONS SUCH AS THE I-25 CORRIDOR AND
PORTIONS OF THE EASTERN PLAINS WILL HAVE THE HIGHEST POTENTIAL OF
RECEIVING MEASURABLE PRECIPITATION DURING THE LATER MONDAY INTO
TUESDAY TIME-FRAME.
WARMEST TEMPERATURES DURING THE LONGER TERM SHOULD BE NOTED
SATURDAY...WITH COOLEST READINGS EXPECTED THURSDAY AND THEN AGAIN
BY NEXT MONDAY AND TUESDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 425 AM MST WED JAN 20 2016
KCOS AND KPUB SHOULD SEE VFR CONDITIONS TODAY WITH THE POTENTIAL FOR
SOME GUSTY WEST TO NW WINDS THIS AFTERNOON. AS A FRONT MOVES THRU
THESE LOCATIONS THIS EVENING...THE WINDS WL BE NW TO N AND GUSTY.
THE COULD BE A FEW SNOW SHOWERS IN THE VCNTY OF THE TERMINALS THIS
EVENING WHICH COULD BRING LOWER CIGS FOR A BRIEF PERIOD.
KALS SHOULD HAVE VFR CONDITIONS THRU THE PERIOD...ALTHOUGH THERE WL
BE THE POTENTIAL FOR SOME SNOW SHOWERS IN THE VCNTY THIS EVENING
WHICH COULD BRING A BRIEF PERIOD OF LOWER CIGS. AS A DISTURBANCE
PASSES THE ARE TONIGHT...WINDS ARE EXPECTED TO BECOME NORTHWESTERLY
AND COULD BE BREEZY FOR A FEW HOURS.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL MIDNIGHT MST TONIGHT FOR COZ058-
060-066.
&&
$$
UPDATE...PETERSEN
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
547 PM EST WED JAN 20 2016
.SYNOPSIS...
THE SURFACE PRESSURE RIDGE WILL REMAIN NEAR THE FORECAST AREA
TODAY AND HELP LIMIT MOISTURE ASSOCIATED WITH AN UPPER- LEVEL
DISTURBANCE MOVING INTO THE AREA THIS AFTERNOON. MOISTURE WILL
INCREASE THURSDAY AHEAD OF LOW PRESSURE APPROACHING FROM THE WEST.
THE LOW WILL CROSS THE AREA FRIDAY INTO FRIDAY NIGHT. DRY HIGH
PRESSURE WILL RETURN FOR SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
UPDATE...RADAR...SURFACE OBS...AND PUBLIC REPORTS INDICATE AREA
OF LIGHT RAIN AND LIGHT SLEET MIX INTO THE CSRA AND CENTRAL
MIDLANDS. NO ACCUMULATION EXPECTED AS SURFACE TEMPS WILL
REMAIN WELL ABOVE FREEZING. LATEST HIGH RESOLUTION MODELS SUGGEST
THE PRECIPITATION AREA WILL DECREASE IN COVERAGE AS IT MOVES EAST
ACROSS OUR FORECAST AREA (FA) THROUGH EARLY THIS EVENING.
FOR TONIGHT...MOISTURE WILL FURTHER DIMINISH BEHIND THE MID-LEVEL
SHORTWAVE TROUGH THIS EVENING. THE NAM AND GFS TIME-HEIGHT DISPLAYS
INDICATE LINGERING LOW-LEVEL MOISTURE BELOW THE SNOW-GROWTH ZONE.
FORECASTED A SLIGHT RAIN CHANCE IN THE EVENING BASED ON THE HRRR AND
SPC WRF. LITTLE CONVERGENCE WILL BE ASSOCIATED WITH THE COLD FRONT
LATE. WILL KEEP A LOW CHANCE POP MAINLY IN THE CSRA LATE TONIGHT.
OVERNIGHT LOWS RANGING FROM NEAR 30 EXTREME NORTH TO NEAR 40
SOUTH.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY NIGHT/...
UPDATED...THREAT FOR WINTRY PRECIPITATION WITH SIGNIFICANT
IMPACTS INCREASING ACROSS THE NORTHERN MIDLANDS MAINLY FOR
FREEZING RAIN LATE THURSDAY NIGHT THROUGH FRIDAY. WILL POST WINTER
STORM WATCH...
THURSDAY...A STRONG STORM SYSTEM WILL DEVELOP OVER THE LOWER- MID
MISSISSIPPI VALLEY AS AN UPPER TROUGH DEEPENS ACROSS THE MIDDLE OF
THE COUNTRY. A WARM FRONT WILL DEVELOP ALONG THE GULF COAST STATES
AS THE FORMATION OF A SURFACE LOW OCCURS OVER EAST TEXAS/NORTHERN
LOUISIANA AND STRENGTHENING SOUTHERLY 850MB FLOW OFF THE GULF OF
MEXICO INCREASES MOISTURE ACROSS THE FORECAST AREA. ATMOSPHERIC
COLUMN WILL INITIALLY BE QUITE DRY ON THURSDAY WITH PWAT VALUES
LESS THAN A HALF INCH WITH SIGNIFICANT DRY AIR ABOVE 5000FT BUT
THE MOISTURE WILL INCREASE THROUGH THE DAY AS ISENTROPIC LIFT
DEVELOPS NORTH OF THE WARM FRONT AND SATURATES THE COLUMN. BY 00Z
FRIDAY THE PWAT VALUES WILL BE JUST UNDER 1 INCH.
PRECIPITATION ASSOCIATED WITH ISENTROPIC LIFT AND MAYBE A WEAK UPPER
DISTURBANCE IN THE SOUTHWESTERLY FLOW WILL LEAD TO INCREASING POPS
THROUGH THE DAY FROM SOUTHWEST TO NORTHEAST...ALTHOUGH THE LATEST
MODEL RUNS HAVE TRENDED A BIT SLOWER WITH THE ONSET. THERE MAY BE
SOME DIABATIC COOLING EFFECTS FROM PRECIPITATION FALLING INTO AN
INITIALLY DRY AIRMASS...FORECAST SURFACE WETBULB TEMPS ARE EXPECTED
TO BE ABOVE FREEZING...YIELDING LIQUID RAINFALL. TEMPERATURES WILL
BE SLOW TO RISE ON THURSDAY AND WILL LEAN TOWARDS THE COOLER
GUIDANCE GIVEN CLOUD COVER AND SOME DIABATIC COOLING WITH
PRECIPITATION.
THURSDAY NIGHT AND FRIDAY...SIGNIFICANT DEEPENING OF THE SURFACE LOW
OVER THE MISSISSIPPI VALLEY WILL OCCUR IN RESPONSE TO A NEGATIVE
TILTING OF THE UPPER TROUGH AS IT TRANSITIONS INTO A CLOSED LOW OVER
MS/AL. ISENTROPIC LIFT WILL STRENGTHEN OVER THE REGION THROUGH
FRIDAY MORNING AS THE WARM FRONT SLOWLY LIFTS NORTHWARD AND WILL
CARRY CATEGORICAL POPS. CONFLUENT 500MB FLOW OVER THE EASTERN OHIO
VALLEY AND NORTHEAST WILL RESULT IN A STRENGTHENING SURFACE RIDGE
OVER THE MID ATLANTIC AND COLD AIR DAMMING WILL DEVELOP ACROSS VA/NC
INTO THE NORTHERN PORTION OF THE FORECAST AREA THURSDAY NIGHT INTO
FRIDAY. WETBULB TEMPERATURES DROP ACROSS THE NORTHERN MIDLANDS
FALLING BELOW FREEZING BY EARLY FRIDAY MORNING. THIS WILL LIKELY
RESULT IN A PERIOD OF FREEZING RAIN IN THE NORTHERN MIDLANDS. THERE
REMAIN SOME DIFFERENCES AMONG THE GUIDANCE ON LOW LEVEL THERMAL
PROFILES WITH THE NAM/CANADIAN BEING COLDER THAN THE GFS WHICH LEADS
TO SOME UNCERTAINTY AS TO HOW FAR SOUTH THE FREEZING RAIN MAY BE.
COMPLEX STORM SYSTEM EVOLUTION ON FRIDAY SHOWS THE INITIAL
SURFACE LOW LIFTING NORTHEASTWARD INTO EASTERN TENNESSEE WITH A
TRANSITION TO A COASTAL LOW DEVELOPING SOMEWHERE OVER EASTERN
SOUTH CAROLINA BY 00Z SATURDAY.
RELATIVELY STEADY TEMPERATURES THURSDAY NIGHT WITH CLOUDS AND
PRECIPITATION ALTHOUGH TEMPERATURES WILL LIKELY FALL ACROSS THE
NORTHERN MIDLANDS. EXPECT A STRONG GRADIENT IN TEMPERATURES ON
FRIDAY AS SURFACE LOW APPROACHES AND WARM ADVECTION OCCURS ACROSS
THE SOUTHERN PART OF THE AREA WHILE THE WEDGE HOLDS STRONG ACROSS
THE NORTH...THOUGH TEMPERATURES UP NORTH SHOULD ALSO RISE A BIT
FRIDAY AFTERNOON.
THIS LOOKS TO BE A POTENTIALLY SIGNIFICANT QPF EVENT WITH LIQUID
ACCUMULATIONS OF A 0.50-1.00 INCH WITH ACCUMULATING FREEZING RAIN
ACROSS PARTS OF THE NORTHERN MIDLANDS COUNTIES. WILL INCLUDE SOME
LIGHT ICE ACCUMULATION ACROSS THE NORTHERN MIDLANDS WITH THIS
FORECAST ISSUANCE BUT WILL HOLD OFF ON ANY HEADLINES AND ALLOW
LATER SHIFTS TO VIEW NEW DATA AND ISSUE A WATCH FOR
LANCASTER/CHESTERFIELD IF NEEDED.
FRIDAY NIGHT AND SATURDAY...SURFACE LOW DEEPENS AND MOVES UP THE
COAST TO NEAR NORFOLK BY 12Z SATURDAY WHILE THE CLOSED UPPER LOW
SLOWLY MOVES OVER THE SOUTHERN APPALACHIANS BY SATURDAY MORNING. MID
LEVEL DRY SLOT FORECAST TO MOVE OVER THE FORECAST AREA FRIDAY NIGHT
INTO EARLY SATURDAY WHICH WILL RESULT IN MUCH LOWER POPS FRIDAY
NIGHT.
THE UPPER LOW WILL DRIFT EAST ACROSS THE CAROLINAS ON SATURDAY WITH
THE CORE OF THE COLD AIR ALOFT MOVING OVER THE FORECAST AREA WITH
500MB TEMPS AS COLD AS -26C TO -27C. THE AMOUNT OF MOISTURE
ASSOCIATED WITH THE UPPER LOW IS THE MAIN UNCERTAINTY AT THIS POINT
WITH THE NAM/CANADIAN SHOWING MUCH MORE SHALLOW MOISTURE COMPARED TO
THE GFS/ECMWF. CANNOT RULE OUT SOME RAIN/SNOW MIX ON SATURDAY
ACROSS THE AREA BUT POPS WILL BE LOW AND LIQUID ACCUMULATION IS
EXPECTED TO BE LIGHT...BUT ANY ACCUMULATION IS EXPECTED TO BE
LIGHT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
MODELS ARE IN FAIRLY GOOD AGREEMENT AND CONTINUE TO COME TOWARD A
CONSENSUS WITH THE LOW PRESSURE SYSTEM CROSSING THE AREA FRIDAY
THROUGH SATURDAY. THE GFS IS SLIGHTLY FASTER THAN THE ECMWF.
THE STORM SYSTEM WILL TRACK ACROSS THE REGION FRIDAY PROVIDING
WIDESPREAD PRECIPITATION. THE AREA OF LOW PRESSURE SHOULD MOVE
EAST OF THE MIDLANDS FRIDAY NIGHT THEN TURN NORTHEASTWARD AND
MOVE ALONG TO THE MID ATLANTIC COAST SATURDAY. AS LOW PRESSURE
SYSTEM DEEPENS OFF THE NC/VA COAST LATE FRIDAY NIGHT...PARTIAL
THICKNESS SCHEMES SUGGEST WINTRY PRECIPITATION POSSIBLE ACROSS THE
NORTHERN AND WESTERN MIDLANDS AS WELL AS THE PIEDMONT...ALTHOUGH
MOISTURE MAY BE SHALLOW. ALTHOUGH QPF VALUES WILL BE LOW HAVE
REMAINED WITH THE POTENTIAL RAIN/SNOW MIXTURE ASSOCIATED WITH WRAP
AROUND MOISTURE. UNCERTAINTY REMAINS QUITE HIGH. HIGH PRESSURE AND
DRIER AIR WILL RETURN TO THE REGION FOR SUNDAY AND MONDAY WITH THE
NEXT LOW PRESSURE SYSTEM WILL PUSH A COLD FRONT TOWARD THE AREA
MONDAY NIGHT.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
A LIGHT RAIN AND SLEET MIXTURE EXPECTED IN THE NEAR TERM. NO SLEET
ACCUMULATION DUE TO TEMPERATURES WELL ABOVE FREEZING. CLOUD BASES
ARE ABOVE VFR LEVEL. PRECIPITATION EXPECTED TO DIMINISH EARLY THIS
EVENING...WITH MID LEVEL CLOUDINESS REMAINING IN PLACE. LIGHT WINDS.
LIGHT RAIN POSSIBLE THURSDAY...BUT CLOUD BASES ARE EXPECTED TO
REMAIN ABOVE VFR LEVEL THRU 18Z.
EXTENDED AVIATION OUTLOOK....PRECIPITATION AND WIDESPREAD IFR TO
MVFR CONDITIONS THURSDAY NIGHT THROUGH SATURDAY.
BREEZY CONDITIONS POSSIBLE SATURDAY/SATURDAY NIGHT.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...WINTER STORM WATCH FROM LATE THURSDAY NIGHT THROUGH SATURDAY
EVENING FOR SCZ015-016.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
532 PM EST WED JAN 20 2016
.SYNOPSIS...
THE SURFACE PRESSURE RIDGE WILL REMAIN NEAR THE FORECAST AREA
TODAY AND HELP LIMIT MOISTURE ASSOCIATED WITH AN UPPER- LEVEL
DISTURBANCE MOVING INTO THE AREA THIS AFTERNOON. MOISTURE WILL
INCREASE THURSDAY AHEAD OF LOW PRESSURE APPROACHING FROM THE WEST.
THE LOW WILL CROSS THE AREA FRIDAY INTO FRIDAY NIGHT. DRY HIGH
PRESSURE WILL RETURN FOR SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
UPDATE...RADAR AND SURFACE OBS INDICATE AREA OF LIGHT RAIN AND
LIGHT SNOW ACROSS THE UPSTATE SC AND N GA...MOVING EAST. LATEST
HIGH RESOLUTION MODELS SUGGEST THE PRECIPITATION AREA WILL
DECREASE IN COVERAGE AS IT MOVES EAST INTO OUR FORECAST AREA (FA)
LATE THIS AFTERNOON AND EARLY EVENING. HOWEVER...CHANCE OF
PRECIPITATION IN THE VERY NEAR TERM APPEARS VERY HIGH AT LEAST
ACROSS THE NORTHERN FA. LATEST GUIDANCE AND TRENDS SUGGEST THE
NORTHERN FA COULD SEE A MIX OF LIGHT RAIN...LIGHT SNOW...OR SLEET
IN THE NEAR TERM. NO ACCUMULATION EXPECTED AS SURFACE TEMPS WILL
REMAIN WELL ABOVE FREEZING.
FOR TONIGHT...MOISTURE WILL FURTHER DIMINISH BEHIND THE MID-LEVEL
SHORTWAVE TROUGH THIS EVENING. THE NAM AND GFS TIME-HEIGHT DISPLAYS
INDICATE LINGERING LOW-LEVEL MOISTURE BELOW THE SNOW-GROWTH ZONE.
FORECASTED A SLIGHT RAIN CHANCE IN THE EVENING BASED ON THE HRRR AND
SPC WRF. LITTLE CONVERGENCE WILL BE ASSOCIATED WITH THE COLD FRONT
LATE. WILL KEEP A LOW CHANCE POP MAINLY IN THE CSRA LATE TONIGHT.
OVERNIGHT LOWS RANGING FROM NEAR 30 EXTREME NORTH TO NEAR 40
SOUTH.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY NIGHT/...
...UPDATED...THREAT FOR WINTRY PRECIPITATION WITH SIGNIFICANT
IMPACTS INCREASING ACROSS THE NORTHERN MIDLANDS MAINLY FOR
FREEZING RAIN LATE THURSDAY NIGHT THROUGH FRIDAY. WILL POST WINTER
STORM WATCH...
THURSDAY...A STRONG STORM SYSTEM WILL DEVELOP OVER THE LOWER- MID
MISSISSIPPI VALLEY AS AN UPPER TROUGH DEEPENS ACROSS THE MIDDLE OF
THE COUNTRY. A WARM FRONT WILL DEVELOP ALONG THE GULF COAST STATES
AS THE FORMATION OF A SURFACE LOW OCCURS OVER EAST TEXAS/NORTHERN
LOUISIANA AND STRENGTHENING SOUTHERLY 850MB FLOW OFF THE GULF OF
MEXICO INCREASES MOISTURE ACROSS THE FORECAST AREA. ATMOSPHERIC
COLUMN WILL INITIALLY BE QUITE DRY ON THURSDAY WITH PWAT VALUES
LESS THAN A HALF INCH WITH SIGNIFICANT DRY AIR ABOVE 5000FT BUT
THE MOISTURE WILL INCREASE THROUGH THE DAY AS ISENTROPIC LIFT
DEVELOPS NORTH OF THE WARM FRONT AND SATURATES THE COLUMN. BY 00Z
FRIDAY THE PWAT VALUES WILL BE JUST UNDER 1 INCH.
PRECIPITATION ASSOCIATED WITH ISENTROPIC LIFT AND MAYBE A WEAK UPPER
DISTURBANCE IN THE SOUTHWESTERLY FLOW WILL LEAD TO INCREASING POPS
THROUGH THE DAY FROM SOUTHWEST TO NORTHEAST...ALTHOUGH THE LATEST
MODEL RUNS HAVE TRENDED A BIT SLOWER WITH THE ONSET. THERE MAY BE
SOME DIABATIC COOLING EFFECTS FROM PRECIPITATION FALLING INTO AN
INITIALLY DRY AIRMASS...FORECAST SURFACE WETBULB TEMPS ARE EXPECTED
TO BE ABOVE FREEZING...YIELDING LIQUID RAINFALL. TEMPERATURES WILL
BE SLOW TO RISE ON THURSDAY AND WILL LEAN TOWARDS THE COOLER
GUIDANCE GIVEN CLOUD COVER AND SOME DIABATIC COOLING WITH
PRECIPITATION.
THURSDAY NIGHT AND FRIDAY...SIGNIFICANT DEEPENING OF THE SURFACE LOW
OVER THE MISSISSIPPI VALLEY WILL OCCUR IN RESPONSE TO A NEGATIVE
TILTING OF THE UPPER TROUGH AS IT TRANSITIONS INTO A CLOSED LOW OVER
MS/AL. ISENTROPIC LIFT WILL STRENGTHEN OVER THE REGION THROUGH
FRIDAY MORNING AS THE WARM FRONT SLOWLY LIFTS NORTHWARD AND WILL
CARRY CATEGORICAL POPS. CONFLUENT 500MB FLOW OVER THE EASTERN OHIO
VALLEY AND NORTHEAST WILL RESULT IN A STRENGTHENING SURFACE RIDGE
OVER THE MID ATLANTIC AND COLD AIR DAMMING WILL DEVELOP ACROSS VA/NC
INTO THE NORTHERN PORTION OF THE FORECAST AREA THURSDAY NIGHT INTO
FRIDAY. WETBULB TEMPERATURES DROP ACROSS THE NORTHERN MIDLANDS
FALLING BELOW FREEZING BY EARLY FRIDAY MORNING. THIS WILL LIKELY
RESULT IN A PERIOD OF FREEZING RAIN IN THE NORTHERN MIDLANDS. THERE
REMAIN SOME DIFFERENCES AMONG THE GUIDANCE ON LOW LEVEL THERMAL
PROFILES WITH THE NAM/CANADIAN BEING COLDER THAN THE GFS WHICH LEADS
TO SOME UNCERTAINTY AS TO HOW FAR SOUTH THE FREEZING RAIN MAY BE.
COMPLEX STORM SYSTEM EVOLUTION ON FRIDAY SHOWS THE INITIAL
SURFACE LOW LIFTING NORTHEASTWARD INTO EASTERN TENNESSEE WITH A
TRANSITION TO A COASTAL LOW DEVELOPING SOMEWHERE OVER EASTERN
SOUTH CAROLINA BY 00Z SATURDAY.
RELATIVELY STEADY TEMPERATURES THURSDAY NIGHT WITH CLOUDS AND
PRECIPITATION ALTHOUGH TEMPERATURES WILL LIKELY FALL ACROSS THE
NORTHERN MIDLANDS. EXPECT A STRONG GRADIENT IN TEMPERATURES ON
FRIDAY AS SURFACE LOW APPROACHES AND WARM ADVECTION OCCURS ACROSS
THE SOUTHERN PART OF THE AREA WHILE THE WEDGE HOLDS STRONG ACROSS
THE NORTH...THOUGH TEMPERATURES UP NORTH SHOULD ALSO RISE A BIT
FRIDAY AFTERNOON.
THIS LOOKS TO BE A POTENTIALLY SIGNIFICANT QPF EVENT WITH LIQUID
ACCUMULATIONS OF A 0.50-1.00 INCH WITH ACCUMULATING FREEZING RAIN
ACROSS PARTS OF THE NORTHERN MIDLANDS COUNTIES. WILL INCLUDE SOME
LIGHT ICE ACCUMULATION ACROSS THE NORTHERN MIDLANDS WITH THIS
FORECAST ISSUANCE BUT WILL HOLD OFF ON ANY HEADLINES AND ALLOW
LATER SHIFTS TO VIEW NEW DATA AND ISSUE A WATCH FOR
LANCASTER/CHESTERFIELD IF NEEDED.
FRIDAY NIGHT AND SATURDAY...SURFACE LOW DEEPENS AND MOVES UP THE
COAST TO NEAR NORFOLK BY 12Z SATURDAY WHILE THE CLOSED UPPER LOW
SLOWLY MOVES OVER THE SOUTHERN APPALACHIANS BY SATURDAY MORNING. MID
LEVEL DRY SLOT FORECAST TO MOVE OVER THE FORECAST AREA FRIDAY NIGHT
INTO EARLY SATURDAY WHICH WILL RESULT IN MUCH LOWER POPS FRIDAY
NIGHT.
THE UPPER LOW WILL DRIFT EAST ACROSS THE CAROLINAS ON SATURDAY WITH
THE CORE OF THE COLD AIR ALOFT MOVING OVER THE FORECAST AREA WITH
500MB TEMPS AS COLD AS -26C TO -27C. THE AMOUNT OF MOISTURE
ASSOCIATED WITH THE UPPER LOW IS THE MAIN UNCERTAINTY AT THIS POINT
WITH THE NAM/CANADIAN SHOWING MUCH MORE SHALLOW MOISTURE COMPARED TO
THE GFS/ECMWF. CANNOT RULE OUT SOME RAIN/SNOW MIX ON SATURDAY
ACROSS THE AREA BUT POPS WILL BE LOW AND LIQUID ACCUMULATION IS
EXPECTED TO BE LIGHT...BUT ANY ACCUMULATION IS EXPECTED TO BE
LIGHT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
MODELS ARE IN FAIRLY GOOD AGREEMENT AND CONTINUE TO COME TOWARD A
CONSENSUS WITH THE LOW PRESSURE SYSTEM CROSSING THE AREA FRIDAY
THROUGH SATURDAY. THE GFS IS SLIGHTLY FASTER THAN THE ECMWF.
THE STORM SYSTEM WILL TRACK ACROSS THE REGION FRIDAY PROVIDING
WIDESPREAD PRECIPITATION. THE AREA OF LOW PRESSURE SHOULD MOVE
EAST OF THE MIDLANDS FRIDAY NIGHT THEN TURN NORTHEASTWARD AND
MOVE ALONG TO THE MID ATLANTIC COAST SATURDAY. AS LOW PRESSURE
SYSTEM DEEPENS OFF THE NC/VA COAST LATE FRIDAY NIGHT...PARTIAL
THICKNESS SCHEMES SUGGEST WINTRY PRECIPITATION POSSIBLE ACROSS THE
NORTHERN AND WESTERN MIDLANDS AS WELL AS THE PIEDMONT...ALTHOUGH
MOISTURE MAY BE SHALLOW. ALTHOUGH QPF VALUES WILL BE LOW HAVE
REMAINED WITH THE POTENTIAL RAIN/SNOW MIXTURE ASSOCIATED WITH WRAP
AROUND MOISTURE. UNCERTAINTY REMAINS QUITE HIGH. HIGH PRESSURE AND
DRIER AIR WILL RETURN TO THE REGION FOR SUNDAY AND MONDAY WITH THE
NEXT LOW PRESSURE SYSTEM WILL PUSH A COLD FRONT TOWARD THE AREA
MONDAY NIGHT.
&&
.AVIATION /22Z WEDNESDAY THROUGH MONDAY/...
EXPECT VFR CONDITIONS THROUGH THE TAF PERIOD. THE DRY SURFACE
PRESSURE RIDGE WILL CONTINUE TO EXTEND INTO THE AREA. A MID-LEVEL
SHORTWAVE TROUGH WILL HELP SUPPORT VFR CEILINGS THIS AFTERNOON INTO
TONIGHT. THERE MAY ALSO BE A PERIOD OF SPRINKLES LATE THIS AFTERNOON
INTO THE EVENING. THE HRRR CONTINUES TO DISPLAY A DIMINISHING AREA
OF PRECIPITATION MOVING INTO THE AREA FROM THE WEST DURING THAT TIME
ASSOCIATED WITH THE UPPER-LEVEL FEATURE. A FEW SPRINKLES POSSIBLE
DURING THE OVERNIGHT HOURS IN THE CSRA BUT NOT ENOUGH CONFIDENCE TO
MENTION AT THIS TIME. WINDS WILL BE MAINLY LIGHT AND VARIABLE THIS
AFTERNOON THROUGH TONIGHT...BECOMING LIGHT FROM THE EAST AFTER
SUNRISE THURSDAY MORNING.
EXTENDED AVIATION OUTLOOK....A LOW PRESSURE SYSTEM MAY BRING
WIDESPREAD MVFR OR IFR CONDITIONS THURSDAY AFTERNOON THROUGH
SATURDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...WINTER STORM WATCH FROM LATE THURSDAY NIGHT THROUGH SATURDAY
EVENING FOR SCZ015-016.
&&
$$
SYNOPSIS...99
NEAR TERM...99
SHORT TERM...99
LONG TERM...99
AVIATION...99
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
406 PM EST WED JAN 20 2016
.SYNOPSIS...
THE SURFACE PRESSURE RIDGE WILL REMAIN NEAR THE FORECAST AREA
TODAY AND HELP LIMIT MOISTURE ASSOCIATED WITH AN UPPER- LEVEL
DISTURBANCE MOVING INTO THE AREA THIS AFTERNOON. MOISTURE WILL
INCREASE THURSDAY AHEAD OF LOW PRESSURE APPROACHING FROM THE WEST.
THE LOW WILL CROSS THE AREA FRIDAY INTO FRIDAY NIGHT. DRY HIGH
PRESSURE WILL RETURN FOR SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
UPDATE...RADAR AND SURFACE OBS INDICATE AREA OF LIGHT RAIN AND
LIGHT SNOW ACROSS THE UPSTATE SC AND N GA...MOVING EAST. LATEST
HIGH RESOLUTION MODELS SUGGEST THE PRECIPITATION AREA WILL
DECREASE IN COVERAGE AS IT MOVES EAST INTO OUR FORECAST AREA (FA)
LATE THIS AFTERNOON AND EARLY EVENING. HOWEVER...CHANCE OF
PRECIPITATION IN THE VERY NEAR TERM APPEARS VERY HIGH AT LEAST
ACROSS THE NORTHERN FA. LATEST GUIDANCE AND TRENDS SUGGEST THE
NORTHERN FA COULD SEE A MIX OF LIGHT RAIN...LIGHT SNOW...OR SLEET
IN THE NEAR TERM. NO ACCUMULATION EXPECTED AS SURFACE TEMPS WILL
REMAIN WELL ABOVE FREEZING.
FOR TONIGHT...MOISTURE WILL FURTHER DIMINISH BEHIND THE MID-LEVEL
SHORTWAVE TROUGH THIS EVENING. THE NAM AND GFS TIME-HEIGHT DISPLAYS
INDICATE LINGERING LOW-LEVEL MOISTURE BELOW THE SNOW-GROWTH ZONE.
FORECASTED A SLIGHT RAIN CHANCE IN THE EVENING BASED ON THE HRRR AND
SPC WRF. LITTLE CONVERGENCE WILL BE ASSOCIATED WITH THE COLD FRONT
LATE. WILL KEEP A LOW CHANCE POP MAINLY IN THE CSRA LATE TONIGHT.
OVERNIGHT LOWS RANGING FROM NEAR 30 EXTREME NORTH TO NEAR 40
SOUTH.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY NIGHT/...
THURSDAY...A STRONG STORM SYSTEM WILL DEVELOP OVER THE LOWER-MID
MISSISSIPPI VALLEY AS AN UPPER TROUGH DEEPENS ACROSS THE MIDDLE OF
THE COUNTRY. A WARM FRONT WILL DEVELOP ALONG THE GULF COAST STATES
AS THE FORMATION OF A SURFACE LOW OCCURS OVER EAST TEXAS/NORTHERN
LOUISIANA AND STRENGTHENING SOUTHERLY 850MB FLOW OFF THE GULF OF
MEXICO INCREASES MOISTURE ACROSS THE FORECAST AREA. ATMOSPHERIC
COLUMN WILL INITIALLY BE QUITE DRY ON THURSDAY WITH PWAT VALUES
LESS THAN A HALF INCH WITH SIGNIFICANT DRY AIR ABOVE 5000FT BUT
THE MOISTURE WILL INCREASE THROUGH THE DAY AS ISENTROPIC LIFT
DEVELOPS NORTH OF THE WARM FRONT AND SATURATES THE COLUMN. BY 00Z
FRIDAY THE PWAT VALUES WILL BE JUST UNDER 1 INCH.
PRECIPITATION ASSOCIATED WITH ISENTROPIC LIFT AND MAYBE A WEAK UPPER
DISTURBANCE IN THE SOUTHWESTERLY FLOW WILL LEAD TO INCREASING POPS
THROUGH THE DAY FROM SOUTHWEST TO NORTHEAST...ALTHOUGH THE LATEST
MODEL RUNS HAVE TRENDED A BIT SLOWER WITH THE ONSET. THERE MAY BE
SOME DIABATIC COOLING EFFECTS FROM PRECIPITATION FALLING INTO AN
INITIALLY DRY AIRMASS...FORECAST SURFACE WETBULB TEMPS ARE EXPECTED
TO BE ABOVE FREEZING...YIELDING LIQUID RAINFALL. TEMPERATURES WILL
BE SLOW TO RISE ON THURSDAY AND WILL LEAN TOWARDS THE COOLER
GUIDANCE GIVEN CLOUD COVER AND SOME DIABATIC COOLING WITH
PRECIPITATION.
THURSDAY NIGHT AND FRIDAY...SIGNIFICANT DEEPENING OF THE SURFACE LOW
OVER THE MISSISSIPPI VALLEY WILL OCCUR IN RESPONSE TO A NEGATIVE
TILTING OF THE UPPER TROUGH AS IT TRANSITIONS INTO A CLOSED LOW OVER
MS/AL. ISENTROPIC LIFT WILL STRENGTHEN OVER THE REGION THROUGH
FRIDAY MORNING AS THE WARM FRONT SLOWLY LIFTS NORTHWARD AND WILL
CARRY CATEGORICAL POPS. CONFLUENT 500MB FLOW OVER THE EASTERN OHIO
VALLEY AND NORTHEAST WILL RESULT IN A STRENGTHENING SURFACE RIDGE
OVER THE MID ATLANTIC AND COLD AIR DAMMING WILL DEVELOP ACROSS VA/NC
INTO THE NORTHERN PORTION OF THE FORECAST AREA THURSDAY NIGHT INTO
FRIDAY. WETBULB TEMPERATURES DROP ACROSS THE NORTHERN MIDLANDS
FALLING BELOW FREEZING BY EARLY FRIDAY MORNING. THIS WILL LIKELY
RESULT IN A PERIOD OF FREEZING RAIN IN THE NORTHERN MIDLANDS. THERE
REMAIN SOME DIFFERENCES AMONG THE GUIDANCE ON LOW LEVEL THERMAL
PROFILES WITH THE NAM/CANADIAN BEING COLDER THAN THE GFS WHICH LEADS
TO SOME UNCERTAINTY AS TO HOW FAR SOUTH THE FREEZING RAIN MAY BE.
COMPLEX STORM SYSTEM EVOLUTION ON FRIDAY SHOWS THE INITIAL
SURFACE LOW LIFTING NORTHEASTWARD INTO EASTERN TENNESSEE WITH A
TRANSITION TO A COASTAL LOW DEVELOPING SOMEWHERE OVER EASTERN
SOUTH CAROLINA BY 00Z SATURDAY.
RELATIVELY STEADY TEMPERATURES THURSDAY NIGHT WITH CLOUDS AND
PRECIPITATION ALTHOUGH TEMPERATURES WILL LIKELY FALL ACROSS THE
NORTHERN MIDLANDS. EXPECT A STRONG GRADIENT IN TEMPERATURES ON
FRIDAY AS SURFACE LOW APPROACHES AND WARM ADVECTION OCCURS ACROSS
THE SOUTHERN PART OF THE AREA WHILE THE WEDGE HOLDS STRONG ACROSS
THE NORTH...THOUGH TEMPERATURES UP NORTH SHOULD ALSO RISE A BIT
FRIDAY AFTERNOON.
THIS LOOKS TO BE A POTENTIALLY SIGNIFICANT QPF EVENT WITH LIQUID
ACCUMULATIONS OF A 0.50-1.00 INCH WITH ACCUMULATING FREEZING RAIN
ACROSS PARTS OF THE NORTHERN MIDLANDS COUNTIES. WILL INCLUDE SOME
LIGHT ICE ACCUMULATION ACROSS THE NORTHERN MIDLANDS WITH THIS
FORECAST ISSUANCE BUT WILL HOLD OFF ON ANY HEADLINES AND ALLOW
LATER SHIFTS TO VIEW NEW DATA AND ISSUE A WATCH FOR
LANCASTER/CHESTERFIELD IF NEEDED.
FRIDAY NIGHT AND SATURDAY...SURFACE LOW DEEPENS AND MOVES UP THE
COAST TO NEAR NORFOLK BY 12Z SATURDAY WHILE THE CLOSED UPPER LOW
SLOWLY MOVES OVER THE SOUTHERN APPALACHIANS BY SATURDAY MORNING. MID
LEVEL DRY SLOT FORECAST TO MOVE OVER THE FORECAST AREA FRIDAY NIGHT
INTO EARLY SATURDAY WHICH WILL RESULT IN MUCH LOWER POPS FRIDAY
NIGHT.
THE UPPER LOW WILL DRIFT EAST ACROSS THE CAROLINAS ON SATURDAY WITH
THE CORE OF THE COLD AIR ALOFT MOVING OVER THE FORECAST AREA WITH
500MB TEMPS AS COLD AS -26C TO -27C. THE AMOUNT OF MOISTURE
ASSOCIATED WITH THE UPPER LOW IS THE MAIN UNCERTAINTY AT THIS POINT
WITH THE NAM/CANADIAN SHOWING MUCH MORE SHALLOW MOISTURE COMPARED TO
THE GFS/ECMWF. CANNOT RULE OUT SOME RAIN/SNOW MIX ON SATURDAY
ACROSS THE AREA BUT POPS WILL BE LOW AND LIQUID ACCUMULATION IS
EXPECTED TO BE LIGHT...BUT ANY ACCUMULATION IS EXPECTED TO BE
LIGHT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
MODELS ARE IN FAIRLY GOOD AGREEMENT AND CONTINUE TO COME TOWARD A
CONSENSUS WITH THE LOW PRESSURE SYSTEM CROSSING THE AREA FRIDAY
THROUGH SATURDAY. THE GFS IS SLIGHTLY FASTER THAN THE ECMWF.
THE STORM SYSTEM WILL TRACK ACROSS THE REGION FRIDAY PROVIDING
WIDESPREAD PRECIPITATION. THE AREA OF LOW PRESSURE SHOULD MOVE
EAST OF THE MIDLANDS FRIDAY NIGHT THEN TURN NORTHEASTWARD AND
MOVE ALONG TO THE MID ATLANTIC COAST SATURDAY. AS LOW PRESSURE
SYSTEM DEEPENS OFF THE NC/VA COAST LATE FRIDAY NIGHT...PARTIAL
THICKNESS SCHEMES SUGGEST WINTRY PRECIPITATION POSSIBLE ACROSS THE
NORTHERN AND WESTERN MIDLANDS AS WELL AS THE PIEDMONT...ALTHOUGH
MOISTURE MAY BE SHALLOW. ALTHOUGH QPF VALUES WILL BE LOW HAVE
REMAINED WITH THE POTENTIAL RAIN/SNOW MIXTURE ASSOCIATED WITH WRAP
AROUND MOISTURE. UNCERTAINTY REMAINS QUITE HIGH. HIGH PRESSURE AND
DRIER AIR WILL RETURN TO THE REGION FOR SUNDAY AND MONDAY WITH THE
NEXT LOW PRESSURE SYSTEM WILL PUSH A COLD FRONT TOWARD THE AREA
MONDAY NIGHT.
&&
.AVIATION /21Z WEDNESDAY THROUGH MONDAY/...
EXPECT VFR CONDITIONS THROUGH THE TAF PERIOD. THE DRY SURFACE
PRESSURE RIDGE WILL CONTINUE TO EXTEND INTO THE AREA. A MID-LEVEL
SHORTWAVE TROUGH WILL HELP SUPPORT VFR CEILINGS THIS AFTERNOON INTO
TONIGHT. THERE MAY ALSO BE A PERIOD OF SPRINKLES LATE THIS AFTERNOON
INTO THE EVENING. THE HRRR CONTINUES TO DISPLAY A DIMINISHING AREA
OF PRECIPITATION MOVING INTO THE AREA FROM THE WEST DURING THAT TIME
ASSOCIATED WITH THE UPPER-LEVEL FEATURE. A FEW SPRINKLES POSSIBLE
DURING THE OVERNIGHT HOURS IN THE CSRA BUT NOT ENOUGH CONFIDENCE TO
MENTION AT THIS TIME. WINDS WILL BE MAINLY LIGHT AND VARIABLE THIS
AFTERNOON THROUGH TONIGHT...BECOMING LIGHT FROM THE EAST AFTER
SUNRISE THURSDAY MORNING.
EXTENDED AVIATION OUTLOOK....A LOW PRESSURE SYSTEM MAY BRING
WIDESPREAD MVFR OR IFR CONDITIONS THURSDAY AFTERNOON THROUGH
SATURDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
&&
$$
SYNOPSIS...99
NEAR TERM...99
SHORT TERM...99
LONG TERM...99
AVIATION...99
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
307 PM EST WED JAN 20 2016
.SYNOPSIS...
THE SURFACE PRESSURE RIDGE WILL REMAIN NEAR THE FORECAST AREA
TODAY AND HELP LIMIT MOISTURE ASSOCIATED WITH AN UPPER- LEVEL
DISTURBANCE MOVING INTO THE AREA THIS AFTERNOON. MOISTURE WILL
INCREASE THURSDAY AHEAD OF LOW PRESSURE APPROACHING FROM THE WEST.
THE LOW WILL CROSS THE AREA FRIDAY INTO FRIDAY NIGHT. DRY HIGH
PRESSURE WILL RETURN FOR SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
REST OF THE AFTERNOON...THE SURFACE RIDGE IS CURRENTLY CENTERED OVER
THE COASTAL PLAIN OF THE CAROLINAS. THE RIDGE WILL HELP LIMIT
MOISTURE ASSOCIATED WITH THE MID-LEVEL SHORTWAVE TROUGH MOVING INTO
THE FORECAST AREA. THE LATEST HRRR INDICATES PRECIPITATION
DIMINISHING AS IT MOVES INTO THE AREA FROM THE WEST THIS AFTERNOON
INTO THE EVENING. EXPECT MUCH OF THE FORECAST AREA WILL HAVE A
PERIOD OF SPRINKLES BUT THE CHANCE OF MEASURABLE PRECIPITATION
SHOULD BE LOW. THE GFS AND NAM PLUS SREF GUIDANCE DISPLAY
PRECIPITATION AMOUNTS OF 0.01 OF AN INCH OR LESS. THE GUIDANCE
CONSENSUS SUPPORTS POPS NEAR 30 PERCENT EXTREME NORTH TO 10 TO 20
PERCENT SOUTH LATER THIS AFTERNOON. THE TOP-DOWN METHOD RUN ON BOTH
THE NAM AND GFS NOW INDICATING PATCHES OF LIGHT RAIN ACROSS THE
NORTHERN AND WESTERN PORTIONS OF THE FORECAST AREA WITH LOW CHANCE
POPS. GIVEN THE POTENTIAL FOR EVAPORATIVE COOLING WITH THE CURRENT
LOW DEWPOINTS...CANNOT RULE OUT A BRIEF MIX OF SOME SNOW WITH THE
RAIN ACROSS PORTIONS IN THE EXTREME NORTH LATER THIS AFTERNOON...BUT
NO ACCUMULATIONS ARE EXPECTED.
FOR TONIGHT...MOISTURE WILL FURTHER DIMINISH BEHIND THE MID-LEVEL
SHORTWAVE TROUGH THIS EVENING. THE NAM AND GFS TIME-HEIGHT DISPLAYS
INDICATE LINGERING LOW-LEVEL MOISTURE BELOW THE SNOW-GROWTH ZONE.
FORECASTED A SLIGHT RAIN CHANCE IN THE EVENING BASED ON THE HRRR AND
SPC WRF. LITTLE CONVERGENCE WILL BE ASSOCIATED WITH THE COLD FRONT
LATE. WILL KEEP A LOW CHANCE POP MAINLY IN THE CSRA LATE TONIGHT.
OVERNIGHT LOWS RANGING FROM NEAR 30 EXTREME NORTH TO NEAR 40
SOUTH.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
THURSDAY...A STRONG STORM SYSTEM WILL DEVELOP OVER THE LOWER-MID
MISSISSIPPI VALLEY AS AN UPPER TROUGH DEEPENS ACROSS THE MIDDLE OF
THE COUNTRY. A WARM FRONT WILL DEVELOP ALONG THE GULF COAST STATES
AS THE FORMATION OF A SURFACE LOW OCCURS OVER EAST TEXAS/NORTHERN
LOUISIANA AND STRENGTHENING SOUTHERLY 850MB FLOW OFF THE GULF OF
MEXICO INCREASES MOISTURE ACROSS THE FORECAST AREA. ATMOSPHERIC
COLUMN WILL INITIALLY BE QUITE DRY ON THURSDAY WITH PWAT VALUES
LESS THAN A HALF INCH WITH SIGNIFICANT DRY AIR ABOVE 5000FT BUT
THE MOISTURE WILL INCREASE THROUGH THE DAY AS ISENTROPIC LIFT
DEVELOPS NORTH OF THE WARM FRONT AND SATURATES THE COLUMN. BY 00Z
FRIDAY THE PWAT VALUES WILL BE JUST UNDER 1 INCH.
PRECIPITATION ASSOCIATED WITH ISENTROPIC LIFT AND MAYBE A WEAK UPPER
DISTURBANCE IN THE SOUTHWESTERLY FLOW WILL LEAD TO INCREASING POPS
THROUGH THE DAY FROM SOUTHWEST TO NORTHEAST...ALTHOUGH THE LATEST
MODEL RUNS HAVE TRENDED A BIT SLOWER WITH THE ONSET. THERE MAY BE
SOME DIABATIC COOLING EFFECTS FROM PRECIPITATION FALLING INTO AN
INITIALLY DRY AIRMASS...FORECAST SURFACE WETBULB TEMPS ARE EXPECTED
TO BE ABOVE FREEZING...YIELDING LIQUID RAINFALL. TEMPERATURES WILL
BE SLOW TO RISE ON THURSDAY AND WILL LEAN TOWARDS THE COOLER
GUIDANCE GIVEN CLOUD COVER AND SOME DIABATIC COOLING WITH
PRECIPITATION.
THURSDAY NIGHT AND FRIDAY...SIGNIFICANT DEEPENING OF THE SURFACE LOW
OVER THE MISSISSIPPI VALLEY WILL OCCUR IN RESPONSE TO A NEGATIVE
TILTING OF THE UPPER TROUGH AS IT TRANSITIONS INTO A CLOSED LOW OVER
MS/AL. ISENTROPIC LIFT WILL STRENGTHEN OVER THE REGION THROUGH
FRIDAY MORNING AS THE WARM FRONT SLOWLY LIFTS NORTHWARD AND WILL
CARRY CATEGORICAL POPS. CONFLUENT 500MB FLOW OVER THE EASTERN OHIO
VALLEY AND NORTHEAST WILL RESULT IN A STRENGTHENING SURFACE RIDGE
OVER THE MID ATLANTIC AND COLD AIR DAMMING WILL DEVELOP ACROSS VA/NC
INTO THE NORTHERN PORTION OF THE FORECAST AREA THURSDAY NIGHT INTO
FRIDAY. WETBULB TEMPERATURES DROP ACROSS THE NORTHERN MIDLANDS
FALLING BELOW FREEZING BY EARLY FRIDAY MORNING. THIS WILL LIKELY
RESULT IN A PERIOD OF FREEZING RAIN IN THE NORTHERN MIDLANDS. THERE
REMAIN SOME DIFFERENCES AMONG THE GUIDANCE ON LOW LEVEL THERMAL
PROFILES WITH THE NAM/CANADIAN BEING COLDER THAN THE GFS WHICH LEADS
TO SOME UNCERTAINTY AS TO HOW FAR SOUTH THE FREEZING RAIN MAY BE.
COMPLEX STORM SYSTEM EVOLUTION ON FRIDAY SHOWS THE INITIAL
SURFACE LOW LIFTING NORTHEASTWARD INTO EASTERN TENNESSEE WITH A
TRANSITION TO A COASTAL LOW DEVELOPING SOMEWHERE OVER EASTERN
SOUTH CAROLINA BY 00Z SATURDAY.
RELATIVELY STEADY TEMPERATURES THURSDAY NIGHT WITH CLOUDS AND
PRECIPITATION ALTHOUGH TEMPERATURES WILL LIKELY FALL ACROSS THE
NORTHERN MIDLANDS. EXPECT A STRONG GRADIENT IN TEMPERATURES ON
FRIDAY AS SURFACE LOW APPROACHES AND WARM ADVECTION OCCURS ACROSS
THE SOUTHERN PART OF THE AREA WHILE THE WEDGE HOLDS STRONG ACROSS
THE NORTH...THOUGH TEMPERATURES UP NORTH SHOULD ALSO RISE A BIT
FRIDAY AFTERNOON.
THIS LOOKS TO BE A POTENTIALLY SIGNIFICANT QPF EVENT WITH LIQUID
ACCUMULATIONS OF A 0.50-1.00 INCH WITH ACCUMULATING FREEZING RAIN
ACROSS PARTS OF THE NORTHERN MIDLANDS COUNTIES. WILL INCLUDE SOME
LIGHT ICE ACCUMULATION ACROSS THE NORTHERN MIDLANDS WITH THIS
FORECAST ISSUANCE BUT WILL HOLD OFF ON ANY HEADLINES AND ALLOW
LATER SHIFTS TO VIEW NEW DATA AND ISSUE A WATCH FOR
LANCASTER/CHESTERFIELD IF NEEDED.
FRIDAY NIGHT AND SATURDAY...SURFACE LOW DEEPENS AND MOVES UP THE
COAST TO NEAR NORFOLK BY 12Z SATURDAY WHILE THE CLOSED UPPER LOW
SLOWLY MOVES OVER THE SOUTHERN APPALACHIANS BY SATURDAY MORNING. MID
LEVEL DRY SLOT FORECAST TO MOVE OVER THE FORECAST AREA FRIDAY NIGHT
INTO EARLY SATURDAY WHICH WILL RESULT IN MUCH LOWER POPS FRIDAY
NIGHT.
THE UPPER LOW WILL DRIFT EAST ACROSS THE CAROLINAS ON SATURDAY WITH
THE CORE OF THE COLD AIR ALOFT MOVING OVER THE FORECAST AREA WITH
500MB TEMPS AS COLD AS -26C TO -27C. THE AMOUNT OF MOISTURE
ASSOCIATED WITH THE UPPER LOW IS THE MAIN UNCERTAINTY AT THIS POINT
WITH THE NAM/CANADIAN SHOWING MUCH MORE SHALLOW MOISTURE COMPARED TO
THE GFS/ECMWF. CANNOT RULE OUT SOME RAIN/SNOW MIX ON SATURDAY
ACROSS THE AREA BUT POPS WILL BE LOW AND LIQUID ACCUMULATION IS
EXPECTED TO BE LIGHT...BUT ANY ACCUMULATION IS EXPECTED TO BE
LIGHT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
MODELS ARE IN FAIRLY GOOD AGREEMENT AND CONTINUE TO COME TOWARD A
CONSENSUS WITH THE LOW PRESSURE SYSTEM CROSSING THE AREA FRIDAY
THROUGH SATURDAY. THE GFS IS SLIGHTLY FASTER THAN THE ECMWF.
THE STORM SYSTEM WILL TRACK ACROSS THE REGION FRIDAY PROVIDING
WIDESPREAD PRECIPITATION. THE AREA OF LOW PRESSURE SHOULD MOVE
EAST OF THE MIDLANDS FRIDAY NIGHT THEN TURN NORTHEASTWARD AND
MOVE ALONG TO THE MID ATLANTIC COAST SATURDAY. AS LOW PRESSURE
SYSTEM DEEPENS OFF THE NC/VA COAST LATE FRIDAY NIGHT...PARTIAL
THICKNESS SCHEMES SUGGEST WINTRY PRECIPITATION POSSIBLE ACROSS THE
NORTHERN AND WESTERN MIDLANDS AS WELL AS THE PIEDMONT...ALTHOUGH
MOISTURE MAY BE SHALLOW. ALTHOUGH QPF VALUES WILL BE LOW HAVE
REMAINED WITH THE POTENTIAL RAIN/SNOW MIXTURE ASSOCIATED WITH WRAP
AROUND MOISTURE. UNCERTAINTY REMAINS QUITE HIGH. HIGH PRESSURE AND
DRIER AIR WILL RETURN TO THE REGION FOR SUNDAY AND MONDAY WITH THE
NEXT LOW PRESSURE SYSTEM WILL PUSH A COLD FRONT TOWARD THE AREA
MONDAY NIGHT.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
EXPECT VFR CONDITIONS THROUGH THE TAF PERIOD. THE DRY SURFACE
PRESSURE RIDGE WILL CONTINUE TO EXTEND INTO THE AREA. A MID-LEVEL
SHORTWAVE TROUGH WILL HELP SUPPORT VFR CEILINGS THIS AFTERNOON INTO
TONIGHT. THERE MAY ALSO BE A PERIOD OF SPRINKLES LATE THIS AFTERNOON
INTO THE EVENING. THE HRRR CONTINUES TO DISPLAY A DIMINISHING AREA
OF PRECIPITATION MOVING INTO THE AREA FROM THE WEST DURING THAT TIME
ASSOCIATED WITH THE UPPER-LEVEL FEATURE. A FEW SPRINKLES POSSIBLE
DURING THE OVERNIGHT HOURS IN THE CSRA BUT NOT ENOUGH CONFIDENCE TO
MENTION AT THIS TIME. WINDS WILL BE MAINLY LIGHT AND VARIABLE THIS
AFTERNOON THROUGH TONIGHT...BECOMING LIGHT FROM THE EAST AFTER
SUNRISE THURSDAY MORNING.
EXTENDED AVIATION OUTLOOK....A LOW PRESSURE SYSTEM MAY BRING
WIDESPREAD MVFR OR IFR CONDITIONS THURSDAY AFTERNOON THROUGH
SATURDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
&&
$$
SYNOPSIS...99
NEAR TERM...99
SHORT TERM...99
LONG TERM...99
AVIATION...99
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
200 PM EST WED JAN 20 2016
.SYNOPSIS...
THE SURFACE PRESSURE RIDGE WILL REMAIN NEAR THE FORECAST AREA
TODAY AND HELP LIMIT MOISTURE ASSOCIATED WITH AN UPPER- LEVEL
DISTURBANCE MOVING INTO THE AREA THIS AFTERNOON. MOISTURE WILL
INCREASE THURSDAY AHEAD OF LOW PRESSURE APPROACHING FROM THE WEST.
THE LOW WILL CROSS THE AREA FRIDAY INTO FRIDAY NIGHT. DRY HIGH
PRESSURE WILL RETURN FOR SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
REST OF THE AFTERNOON...THE SURFACE RIDGE IS CURRENTLY CENTERED OVER
THE COASTAL PLAIN OF THE CAROLINAS. THE RIDGE WILL HELP LIMIT
MOISTURE ASSOCIATED WITH THE MID-LEVEL SHORTWAVE TROUGH MOVING INTO
THE FORECAST AREA. THE LATEST HRRR INDICATES PRECIPITATION
DIMINISHING AS IT MOVES INTO THE AREA FROM THE WEST THIS AFTERNOON
INTO THE EVENING. EXPECT MUCH OF THE FORECAST AREA WILL HAVE A
PERIOD OF SPRINKLES BUT THE CHANCE OF MEASURABLE PRECIPITATION
SHOULD BE LOW. THE GFS AND NAM PLUS SREF GUIDANCE DISPLAY
PRECIPITATION AMOUNTS OF 0.01 OF AN INCH OR LESS. THE GUIDANCE
CONSENSUS SUPPORTS POPS NEAR 30 PERCENT EXTREME NORTH TO 10 TO 20
PERCENT SOUTH LATER THIS AFTERNOON. THE TOP-DOWN METHOD RUN ON BOTH
THE NAM AND GFS NOW INDICATING PATCHES OF LIGHT RAIN ACROSS THE
NORTHERN AND WESTERN PORTIONS OF THE FORECAST AREA WITH LOW CHANCE
POPS. GIVEN THE POTENTIAL FOR EVAPORATIVE COOLING WITH THE CURRENT
LOW DEWPOINTS...CANNOT RULE OUT A BRIEF MIX OF SOME SNOW WITH THE
RAIN ACROSS PORTIONS IN THE EXTREME NORTH LATER THIS AFTERNOON...BUT
NO ACCUMULATIONS ARE EXPECTED.
FOR TONIGHT...MOISTURE WILL FURTHER DIMINISH BEHIND THE MID-LEVEL
SHORTWAVE TROUGH THIS EVENING. THE NAM AND GFS TIME-HEIGHT DISPLAYS
INDICATE LINGERING LOW-LEVEL MOISTURE BELOW THE SNOW-GROWTH ZONE.
FORECASTED A SLIGHT RAIN CHANCE IN THE EVENING BASED ON THE HRRR AND
SPC WRF. LITTLE CONVERGENCE WILL BE ASSOCIATED WITH THE COLD FRONT
LATE. WILL KEEP A LOW CHANCE POP MAINLY IN THE CSRA LATE TONIGHT.
OVERNIGHT LOWS RANGING FROM NEAR 30 EXTREME NORTH TO NEAR 40
SOUTH.
&&
.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
LOW PRESSURE OVER TEXAS THURSDAY MORNING WILL LIFT NORTHEAST
ACROSS THE LOWER MS RIVER VALLEY THROUGH THURSDAY NIGHT. ITS
ASSOCIATED WARM FROM WILL REMAIN SOUTH OF THE CSRA. INCREASING
ISENTROPIC LIFT AHEAD OF THE WARM FRONT WILL SPREAD RAIN INTO THE
AREA...MAINLY AFFECTING THE CSRA AND WESTERN MIDLANDS DURING THE
DAY WITH RAIN CHANCES INCREASING THURSDAY NIGHT AS THE LOW
PRESSURE SYSTEM LIFTS NORTHEAST.
MODELS INDICATE WEAK IN-SITU COLD AIR DAMMING DEVELOPING ACROSS
THE NORTH AND CENTRAL MIDLANDS THURSDAY NIGHT. TEMPERATURES MAY
BE NEAR FREEZING ACROSS PORTIONS OF LANCASTER AND CHESTERFIELD
COUNTIES. THE NAM AND ECMWF MODELS ARE COLDER THAN THE GFS IN THE
1000 MB TO 850 THICKNESS ACROSS THE NORTH MIDLANDS FRIDAY. SREF
SHOW LOW PROBABILITIES FOR FREEZING RAIN IN THAT REGION. WILL
MENTION A SLIGHT CHANCE FREEZING RAIN FOR FRIDAY MORNING. THIS
REMAINS A LOW CONFIDENCE FORECAST.
WENT NEAR GUIDANCE CONSENSUS FOR HIGH TEMPERATURES ON THURSDAY
RANGING FROM THE MID 40S NORTH TO AROUND 50 SOUTH. LOWS ARE
EXPECTED TO BE IN THE LOWER 30S NORTH TO THE MID 40S SOUTH.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
MODELS ARE IN FAIRLY GOOD AGREEMENT AND CONTINUE TO COME TOWARD A
CONSENSUS WITH THE LOW PRESSURE SYSTEM CROSSING THE AREA FRIDAY
THROUGH SATURDAY. THE GFS IS SLIGHTLY FASTER THAN THE ECMWF.
THE STORM SYSTEM WILL TRACK ACROSS THE REGION FRIDAY PROVIDING
WIDESPREAD PRECIPITATION. THE AREA OF LOW PRESSURE SHOULD MOVE
EAST OF THE MIDLANDS FRIDAY NIGHT THEN TURN NORTHEASTWARD AND
MOVE ALONG TO THE MID ATLANTIC COAST SATURDAY. AS LOW PRESSURE
SYSTEM DEEPENS OFF THE NC/VA COAST LATE FRIDAY NIGHT...PARTIAL
THICKNESS SCHEMES SUGGEST WINTRY PRECIPITATION POSSIBLE ACROSS THE
NORTHERN AND WESTERN MIDLANDS AS WELL AS THE PIEDMONT...ALTHOUGH
MOISTURE MAY BE SHALLOW. ALTHOUGH QPF VALUES WILL BE LOW HAVE
REMAINED WITH THE POTENTIAL RAIN/SNOW MIXTURE ASSOCIATED WITH WRAP
AROUND MOISTURE. UNCERTAINTY REMAINS QUITE HIGH. HIGH PRESSURE AND
DRIER AIR WILL RETURN TO THE REGION FOR SUNDAY AND MONDAY WITH THE
NEXT LOW PRESSURE SYSTEM WILL PUSH A COLD FRONT TOWARD THE AREA
MONDAY NIGHT.
&&
.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
EXPECT VFR CONDITIONS THROUGH THE TAF PERIOD. THE DRY SURFACE
PRESSURE RIDGE WILL CONTINUE TO EXTEND INTO THE AREA. A MID-LEVEL
SHORTWAVE TROUGH WILL HELP SUPPORT VFR CEILINGS THIS AFTERNOON INTO
TONIGHT. THERE MAY ALSO BE A PERIOD OF SPRINKLES LATE THIS AFTERNOON
INTO THE EVENING. THE HRRR CONTINUES TO DISPLAY A DIMINISHING AREA
OF PRECIPITATION MOVING INTO THE AREA FROM THE WEST DURING THAT TIME
ASSOCIATED WITH THE UPPER-LEVEL FEATURE. A FEW SPRINKLES POSSIBLE
DURING THE OVERNIGHT HOURS IN THE CSRA BUT NOT ENOUGH CONFIDENCE TO
MENTION AT THIS TIME. WINDS WILL BE MAINLY LIGHT AND VARIABLE THIS
AFTERNOON THROUGH TONIGHT...BECOMING LIGHT FROM THE EAST AFTER
SUNRISE THURSDAY MORNING.
EXTENDED AVIATION OUTLOOK....A LOW PRESSURE SYSTEM MAY BRING
WIDESPREAD MVFR OR IFR CONDITIONS THURSDAY AFTERNOON THROUGH
SATURDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
104 PM EST WED JAN 20 2016
.PREV DISCUSSION... /ISSUED 1058 AM EST WED JAN 20 2016/
.UPDATE...
IMPRESSIVE BAND OF HEAVIER PRECIP IMPINGING INTO NW CWA WITH SOME
LIGHT MORE ISOLATED RETURNS AHEAD OF ASSOCIATED DISTURBANCE. SO
FAR HAVE HAD SOME REPORTS OF FZRA AND SLEET BUT MAINLY IN FAR
NORTH AND MAIN CONCERN OF IMPACTFUL ACCUMULATIONS WILL BE WITH
APPROACHING BAND AS EVAP COOLING MECHANISM HAS SHOWN SOME SFC TEMP
DROPS OF 2-3 DEG. GIVEN THE STILL LOW DWPTS ACROSS THE FAR
NORTHERN TIER WITH VALUES STILL IN UPPER TEENS TO LOW 20S AT SOME
SPOTS...COULD SEE SOME ISOLATED HIGHER ICE ACCUMULATIONS AROUND
0.25 INCHES. ALSO THE HRRR SO FAR LOOKS TO HAVE DECENT HOLD ON
TRENDS WITH P-TYPE AND HAVE ADJUSTED POPS AND WINTER GRIDS
ACCORDINGLY. HRRR PROGGED WETBULB TEMPS KEEP THE NE HIGHER
ELEVATIONS AROUND 30 DEG THROUGH THE AFTERNOON ALONG WITH A
TRANSITION FROM INITIAL MIXED P-TYPE TO PRIMARILY SNOW SO HAVE
INCREASED THE LOWER BOUND SNOW AMOUNTS TO NEAR HALF AN INCH
SLIGHTLY FARTHER SOUTHEAST TO NEAR GAINESVILLE AND EASTWARD. AS
FAR AS NEAR THE METRO...OVERNIGHT TEMPS WERE THANKFULLY ABOUT 4
DEGREES WARMER THAN FCST SO TRENDS HAVE BEEN TO RISE TO 34-36
DEGREES FROM THE WEST. ALL IN ALL HAVE NOT ADJUSTED ANY EXTENT OR
TIMING TO THE CURRENT ADVISORY AND WARNING AREAS. PREVIOUS
DISCUSSION FOLLOWS...
BAKER
&&
PREV DISCUSSION... /ISSUED 652 AM EST WED JAN 20 2016/
PREV DISCUSSION... /ISSUED 437 AM EST WED JAN 20 2016/
.SHORT TERM /TODAY THROUGH THURSDAY/...
SHORT TERM FORECAST CONTINUES TO BE A CHALLENGE WITH IMPACTFUL
WINTRY PRECIPITATION EXPECTED ACROSS NORTH GEORGIA. UPPER LEVEL
DISTURBANCE WILL INTERACT WITH COLD AND DRY CONDITIONS ACROSS THE
AREA TO PRODUCE A WINTRY MIX OVER PORTIONS OF NORTH GEORGIA.
ALTHOUGH MODELS HAVE SLOWED THE ONSET TIMING SLIGHTLY BY AN HOUR OR
SO...CONSENSUS IS THAT PRECIPITATION WILL BEGIN AS SNOW THIS
MORNING...THEN TRANSITION TO FREEZING RAIN/SLEET AND THEN TRANSITION
TO ALL SNOW IN THE NE MOUNTAINS BY THE AFTERNOON. ACCUMULATING
WINTRY MIX IS EXPECTED AS FAR SOUTH AS PORTIONS OF THE NORTHERN
ATLANTA SUBURBS...BUT STILL COULD SEE SOME NON-ACCUMULATING MIX AS
FAR SOUTH AS I-20. ALREADY SEEING SOME LIGHT RETURNS ON RADAR ACROSS
AL/NORTHERN GEORGIA...BUT SO FAR NOTHING REACHING THE GROUND.
MODELS CONTINUE TO SUGGEST THIS TO BE AN OVERALL LOW QPF
EVENT...WITH LIQUID EQUIVALENT ONLY A QUARTER INCH OR LESS. WPC WWD
GUIDANCE HAS BACKED OFF SOMEWHAT ON SNOWFALL TOTALS...BUT HAS SPREAD
THE ACCUMULATING FREEZING RAIN AMOUNTS FARTHER SOUTH. GIVEN THE
TIMING OF THE PRECIPITATION ONSET AND THE EXPECTED WARMING
TEMPERATURES /PARTICULARLY ACROSS THE METRO AREA/ HAVE OPTED NOT TO
DEVIATE TOO FAR FROM THE PREVIOUS SNOW/ICE AMOUNTS PREVIOUSLY
FORECAST...A LITTLE MORE CONSERVATIVE IN AREAL COVERAGE THAN THE WWD
ICE GRID.
THE WINTER STORM WARNING AND THE WINTER WEATHER ADVISORY CONTINUE
WITH NO CHANGES MADE TO THE TIMING OR AREA. STILL ANTICIPATE UP TO 2-
2.5 INCHES OF SNOW IN THE WSW /PARTICULARLY IN THE NE GA MOUNTAINS/
AND UP TO A TENTH OF AN INCH OF ICE. IN THE ADVISORY AREA UP TO 1
INCH OF SNOW AND A TENTH OF AN INCH OF ICE CAN BE EXPECTED. WITH
COLD ANTECEDENT CONDITIONS...IMPACTS ARE EXPECTED AT ONSET OF THE
PRECIPITATION. HAVE ALSO CONTINUED THE SPECIAL WEATHER STATEMENT FOR
SEVERAL COUNTIES JUST SOUTH OF THE ADVISORY AREA TO INDICATE
POTENTIAL FOR WINTRY PRECIPITATION MIXED WITH RAIN.
THERE REMAINS SEVERAL UNCERTAINTIES WITH THE FORECAST THAT WILL NEED
TO BE MONITORED AS THE EVENT UNFOLDS. THE WEAKENING RIDGE AND
EROSION OF THE ASSOCIATED LOW LEVEL INVERSION WILL PLAY A KEY ROLE
IN DURATION OF WINTER PRECIP. THERMODYNAMIC TRENDS WILL STILL NEED
TO BE WATCHED FOR WETBULBING/EVAPORATIVE COOLING EFFECTS AND IF IT
DELAYS THE TRANSITION TO OTHER P-TYPES. LINGERING FREEZING
TEMPERATURES INTO THE OVERNIGHT HOURS COULD ALLOW FROZEN PRECIP TO
CONTINUE AND INCREASE BLACK ICE THREAT.
STAY TUNED AS THE FORECAST CONTINUES TO EVOLVE AS THE EVENT UNFOLDS.
ALTHOUGH THE PRECIPITATION POTENTIAL DIMINISHES SOMEWHAT
OVERNIGHT...ALL RAIN WILL RETURN TO THE AREA THURSDAY AND INTO THE
INITIAL EXTENDED FORECAST PERIODS. ANTICIPATE THAT BY MID MORNING
THURSDAY ALL OF NORTH AND CENTRAL GEORGIA SHOULD BE SEEING ABOVE-
FREEZING TEMPERATURES.
31
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
SOUTHERN STREAM LOW MOVING INTO THE LOWER MS VALLEY AT THE START
OF THE PERIOD...TRACKING THROUGH THE TN VALLEY AND THEN OFF THE
MID ATLANTIC COAST BY SATURDAY MORNING. EXPECTING ALL LIQUID
PRECIP UNTIL FRIDAY NIGHT AS WRAP AROUND MOISTURE SPREADS INTO THE
FORECAST AREA. PARTIAL THICKNESS VALUES WOULD SUPPORT SNOW FOR THE
FAR NORTH AND A MIX OF RAIN AND SNOW FOR THE REMAINDER OF NORTH.
FOR NOW...HAVE KEPT LIGHT ACCUMULATIONS CONFINED TO THE FAR NORTH
SINCE ACTUAL QPF IS STILL QUESTIONABLE. SOME LIGHT WRAP AROUND SNOW
IS POSSIBLE SATURDAY FOR THE EXTREME NORTH AS THE LOW CONTINUES TO
MOVE NORTHEAST. SUNDAY LOOKS DRY BUT THE NEXT LOW IS MOVING INTO
THE MID MS VALLEY BY MONDAY...BRINGING MOISTURE BACK INTO THE
FORECAST AREA. PRECIPITATION SHOULD SPREAD ACROSS NORTH AND
CENTRAL GEORGIA MONDAY AND TUESDAY. LOOKING FOR ALL RAIN MONDAY
AND TUESDAY...HOWEVER LEADING INTO TUESDAY NIGHT THERE IS ANOTHER
CHANCE FOR SOME FREEZING OR FROZEN PRECIP ACROSS FAR NORTH
GEORGIA.
41
&&
.AVIATION...
18Z UPDATE...
INITIAL VFR CONDITIONS SHOULD DEGRADE TO MVFR CIGS BEHIND AREA OF
PRECIP PUSHING EASTWARD THEN IFR CIGS WITH VSBYS IN MVFR/IFR RANGE
AFTER ABOUT 08Z TONIGHT WITH LITTLE TO NO IMPROVEMENT FOR THURSDAY
AFTERNOON. COULD HAVE LINGERING -DZ OVERNIGHT THEN BETTER CHANCE
FOR WIDESPREAD -RA OR -SHRA AGAIN THURSDAY. ANY WINTRY PRECIP
POTENTIAL SHOULD STAY NORTH OF THE TAF SITES INTO THIS EVENING.
WINDS COULD SEE SSW SHIFT IN INITIAL 3-4 HRS THEN BACK TO SE/E
THRU REST OF PERIOD. MAGNITUDES 7-8 KTS BECOMING LIGHT TO CALM
OVERNIGHT AND UNDER 7 KTS FOR THURSDAY.
//ATL CONFIDENCE...18Z UPDATE...
MEDIUM ON ALL ELEMENTS.
BAKER
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 41 33 43 38 / 70 70 70 90
ATLANTA 42 37 47 42 / 80 70 70 90
BLAIRSVILLE 35 31 45 36 / 90 40 70 90
CARTERSVILLE 38 33 46 40 / 90 50 70 90
COLUMBUS 50 43 59 49 / 60 70 60 90
GAINESVILLE 35 32 42 37 / 90 60 70 90
MACON 50 40 54 45 / 40 50 50 70
ROME 37 34 46 41 / 90 30 80 90
PEACHTREE CITY 44 35 49 43 / 70 70 70 90
VIDALIA 54 41 57 47 / 20 20 30 50
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 1 AM EST THURSDAY FOR THE FOLLOWING
ZONES: CATOOSA...CHATTOOGA...DADE...DAWSON...FANNIN...GILMER...
GORDON...LUMPKIN...MURRAY...PICKENS...TOWNS...UNION...WALKER...
WHITE...WHITFIELD.
WINTER WEATHER ADVISORY UNTIL 1 AM EST THURSDAY FOR THE
FOLLOWING ZONES: BANKS...BARTOW...CHEROKEE...FLOYD...FORSYTH...
HALL.
&&
$$
SHORT TERM...31/BAKER
LONG TERM....41
AVIATION...BAKER
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
1058 AM EST WED JAN 20 2016
...HEAVY BAND OF PRECIP CURRENTLY PUSHING ACROSS FAR NORTH
GEORGIA COULD PRODUCE SOME LOCALLY HIGHER ICE ACCUMULATIONS TO
NEAR A QUARTER INCH WITHIN THE CURRENT WINTER STORM WARNING
AREA...
.UPDATE...
IMPRESSIVE BAND OF HEAVIER PRECIP IMPINGING INTO NW CWA WITH SOME
LIGHT MORE ISOLATED RETURNS AHEAD OF ASSOCIATED DISTURBANCE. SO
FAR HAVE HAD SOME REPORTS OF FZRA AND SLEET BUT MAINLY IN FAR
NORTH AND MAIN CONCERN OF IMPACTFUL ACCUMULATIONS WILL BE WITH
APPROACHING BAND AS EVAP COOLING MECHANISM HAS SHOWN SOME SFC TEMP
DROPS OF 2-3 DEG. GIVEN THE STILL LOW DWPTS ACROSS THE FAR
NORTHERN TIER WITH VALUES STILL IN UPPER TEENS TO LOW 20S AT SOME
SPOTS...COULD SEE SOME ISOLATED HIGHER ICE ACCUMULATIONS AROUND
0.25 INCHES. ALSO THE HRRR SO FAR LOOKS TO HAVE DECENT HOLD ON
TRENDS WITH P-TYPE AND HAVE ADJUSTED POPS AND WINTER GRIDS
ACCORDINGLY. HRRR PROGGED WETBULB TEMPS KEEP THE NE HIGHER
ELEVATIONS AROUND 30 DEG THROUGH THE AFTERNOON ALONG WITH A
TRANSITION FROM INITIAL MIXED P-TYPE TO PRIMARILY SNOW SO HAVE
INCREASED THE LOWER BOUND SNOW AMOUNTS TO NEAR HALF AN INCH
SLIGHTLY FARTHER SOUTHEAST TO NEAR GAINESVILLE AND EASTWARD. AS
FAR AS NEAR THE METRO...OVERNIGHT TEMPS WERE THANKFULLY ABOUT 4
DEGREES WARMER THAN FCST SO TRENDS HAVE BEEN TO RISE TO 34-36
DEGREES FROM THE WEST. ALL IN ALL HAVE NOT ADJUSTED ANY EXTENT OR
TIMING TO THE CURRENT ADVISORY AND WARNING AREAS. PREVIOUS
DISCUSSION FOLLOWS...
BAKER
&&
.PREV DISCUSSION... /ISSUED 652 AM EST WED JAN 20 2016/
PREV DISCUSSION... /ISSUED 437 AM EST WED JAN 20 2016/
.SHORT TERM /TODAY THROUGH THURSDAY/...
SHORT TERM FORECAST CONTINUES TO BE A CHALLENGE WITH IMPACTFUL
WINTRY PRECIPITATION EXPECTED ACROSS NORTH GEORGIA. UPPER LEVEL
DISTURBANCE WILL INTERACT WITH COLD AND DRY CONDITIONS ACROSS THE
AREA TO PRODUCE A WINTRY MIX OVER PORTIONS OF NORTH GEORGIA.
ALTHOUGH MODELS HAVE SLOWED THE ONSET TIMING SLIGHTLY BY AN HOUR OR
SO...CONSENSUS IS THAT PRECIPITATION WILL BEGIN AS SNOW THIS
MORNING...THEN TRANSITION TO FREEZING RAIN/SLEET AND THEN TRANSITION
TO ALL SNOW IN THE NE MOUNTAINS BY THE AFTERNOON. ACCUMULATING
WINTRY MIX IS EXPECTED AS FAR SOUTH AS PORTIONS OF THE NORTHERN
ATLANTA SUBURBS...BUT STILL COULD SEE SOME NON-ACCUMULATING MIX AS
FAR SOUTH AS I-20. ALREADY SEEING SOME LIGHT RETURNS ON RADAR ACROSS
AL/NORTHERN GEORGIA...BUT SO FAR NOTHING REACHING THE GROUND.
MODELS CONTINUE TO SUGGEST THIS TO BE AN OVERALL LOW QPF
EVENT...WITH LIQUID EQUIVALENT ONLY A QUARTER INCH OR LESS. WPC WWD
GUIDANCE HAS BACKED OFF SOMEWHAT ON SNOWFALL TOTALS...BUT HAS SPREAD
THE ACCUMULATING FREEZING RAIN AMOUNTS FARTHER SOUTH. GIVEN THE
TIMING OF THE PRECIPITATION ONSET AND THE EXPECTED WARMING
TEMPERATURES /PARTICULARLY ACROSS THE METRO AREA/ HAVE OPTED NOT TO
DEVIATE TOO FAR FROM THE PREVIOUS SNOW/ICE AMOUNTS PREVIOUSLY
FORECAST...A LITTLE MORE CONSERVATIVE IN AREAL COVERAGE THAN THE WWD
ICE GRID.
THE WINTER STORM WARNING AND THE WINTER WEATHER ADVISORY CONTINUE
WITH NO CHANGES MADE TO THE TIMING OR AREA. STILL ANTICIPATE UP TO 2-
2.5 INCHES OF SNOW IN THE WSW /PARTICULARLY IN THE NE GA MOUNTAINS/
AND UP TO A TENTH OF AN INCH OF ICE. IN THE ADVISORY AREA UP TO 1
INCH OF SNOW AND A TENTH OF AN INCH OF ICE CAN BE EXPECTED. WITH
COLD ANTECEDENT CONDITIONS...IMPACTS ARE EXPECTED AT ONSET OF THE
PRECIPITATION. HAVE ALSO CONTINUED THE SPECIAL WEATHER STATEMENT FOR
SEVERAL COUNTIES JUST SOUTH OF THE ADVISORY AREA TO INDICATE
POTENTIAL FOR WINTRY PRECIPITATION MIXED WITH RAIN.
THERE REMAINS SEVERAL UNCERTAINTIES WITH THE FORECAST THAT WILL NEED
TO BE MONITORED AS THE EVENT UNFOLDS. THE WEAKENING RIDGE AND
EROSION OF THE ASSOCIATED LOW LEVEL INVERSION WILL PLAY A KEY ROLE
IN DURATION OF WINTER PRECIP. THERMODYNAMIC TRENDS WILL STILL NEED
TO BE WATCHED FOR WETBULBING/EVAPORATIVE COOLING EFFECTS AND IF IT
DELAYS THE TRANSITION TO OTHER P-TYPES. LINGERING FREEZING
TEMPERATURES INTO THE OVERNIGHT HOURS COULD ALLOW FROZEN PRECIP TO
CONTINUE AND INCREASE BLACK ICE THREAT.
STAY TUNED AS THE FORECAST CONTINUES TO EVOLVE AS THE EVENT UNFOLDS.
ALTHOUGH THE PRECIPITATION POTENTIAL DIMINISHES SOMEWHAT
OVERNIGHT...ALL RAIN WILL RETURN TO THE AREA THURSDAY AND INTO THE
INITIAL EXTENDED FORECAST PERIODS. ANTICIPATE THAT BY MID MORNING
THURSDAY ALL OF NORTH AND CENTRAL GEORGIA SHOULD BE SEEING ABOVE-
FREEZING TEMPERATURES.
31
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
SOUTHERN STREAM LOW MOVING INTO THE LOWER MS VALLEY AT THE START
OF THE PERIOD...TRACKING THROUGH THE TN VALLEY AND THEN OFF THE
MID ATLANTIC COAST BY SATURDAY MORNING. EXPECTING ALL LIQUID
PRECIP UNTIL FRIDAY NIGHT AS WRAP AROUND MOISTURE SPREADS INTO THE
FORECAST AREA. PARTIAL THICKNESS VALUES WOULD SUPPORT SNOW FOR THE
FAR NORTH AND A MIX OF RAIN AND SNOW FOR THE REMAINDER OF NORTH.
FOR NOW...HAVE KEPT LIGHT ACCUMULATIONS CONFINED TO THE FAR NORTH
SINCE ACTUAL QPF IS STILL QUESTIONABLE. SOME LIGHT WRAP AROUND SNOW
IS POSSIBLE SATURDAY FOR THE EXTREME NORTH AS THE LOW CONTINUES TO
MOVE NORTHEAST. SUNDAY LOOKS DRY BUT THE NEXT LOW IS MOVING INTO
THE MID MS VALLEY BY MONDAY...BRINGING MOISTURE BACK INTO THE
FORECAST AREA. PRECIPITATION SHOULD SPREAD ACROSS NORTH AND
CENTRAL GEORGIA MONDAY AND TUESDAY. LOOKING FOR ALL RAIN MONDAY
AND TUESDAY...HOWEVER LEADING INTO TUESDAY NIGHT THERE IS ANOTHER
CHANCE FOR SOME FREEZING OR FROZEN PRECIP ACROSS FAR NORTH
GEORGIA.
41
&&
.AVIATION...
12Z UPDATE...
VFR CONDITIONS THIS MORNING WILL DEGRADE TO MVFR AT THE NORTHERN
TAF SITES BY LATE AFTERNOON WITH -SHRA BEGINNING. -DZ EXPECTED
OVERNIGHT AND CIGS WILL DEGRADE TO IFR. AS -RA RETURNS THURSDAY
MORNING CIGS WILL REMAIN IFR. SE WINDS WILL BECOME SW 18-21Z /OR
POSSIBLY LATER/ THEN SHIFT BACK TO THE E-SE BY THIS
EVENING/OVERNIGHT. SPEEDS GENERALLY 7KT OR LESS. AT SOUTHERN TAF
SITES CIGS WILL DEGRADE TO MVFR BY 10-11Z THURSDAY.
//ATL CONFIDENCE...12Z UPDATE...
MEDIUM ON PRECIPITATION TIMING. HIGH CONFIDENCE ON ALL OTHER
ELEMENTS.
31
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 41 33 43 38 / 40 30 70 90
ATLANTA 42 37 47 42 / 40 40 70 90
BLAIRSVILLE 35 31 45 36 / 80 40 70 90
CARTERSVILLE 38 33 46 40 / 70 40 70 90
COLUMBUS 50 43 59 49 / 20 40 60 90
GAINESVILLE 35 32 42 37 / 60 40 70 90
MACON 50 40 54 45 / 20 30 50 70
ROME 37 34 46 41 / 80 40 80 90
PEACHTREE CITY 44 35 49 43 / 40 40 70 90
VIDALIA 54 41 57 47 / 5 10 30 50
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 1 AM EST THURSDAY FOR THE FOLLOWING
ZONES: CATOOSA...CHATTOOGA...DADE...DAWSON...FANNIN...GILMER...
GORDON...LUMPKIN...MURRAY...PICKENS...TOWNS...UNION...WALKER...
WHITE...WHITFIELD.
WINTER WEATHER ADVISORY UNTIL 1 AM EST THURSDAY FOR THE
FOLLOWING ZONES: BANKS...BARTOW...CHEROKEE...FLOYD...FORSYTH...
HALL.
&&
$$
SHORT TERM...31/BAKER
LONG TERM....41
AVIATION...31
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1030 AM EST WED JAN 20 2016
.SYNOPSIS...
THE SURFACE PRESSURE RIDGE WILL REMAIN NEAR THE FORECAST AREA
TODAY AND HELP LIMIT MOISTURE ASSOCIATED WITH AN UPPER- LEVEL
DISTURBANCE MOVING INTO THE AREA THIS AFTERNOON. MOISTURE WILL
INCREASE THURSDAY AHEAD OF LOW PRESSURE APPROACHING FROM THE WEST.
THE LOW WILL CROSS THE AREA FRIDAY INTO FRIDAY NIGHT. DRY HIGH
PRESSURE WILL RETURN FOR SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE SURFACE RIDGE IN THE FORECAST AREA THIS MORNING WILL BE NEAR
THE COAST THIS AFTERNOON. THE RIDGE AND H85 WESTERLY FLOW WILL
LIMIT MOISTURE ASSOCIATED WITH THE MID-LEVEL SHORTWAVE TROUGH
MOVING INTO THE FORECAST AREA. THE LATEST HRRR INDICATES
PRECIPITATION DIMINISHING AS IT MOVES INTO THE AREA FROM THE WEST
LATE THIS AFTERNOON INTO THE EVENING. EXPECT MUCH OF THE FORECAST
AREA WILL HAVE A PERIOD OF SPRINKLES BUT THE CHANCE OF MEASURABLE
PRECIPITATION SHOULD BE LOW. THE GFS AND NAM PLUS SREF GUIDANCE
DISPLAY PRECIPITATION AMOUNTS OF 0.01 OF AN INCH OR LESS. THE
GUIDANCE CONSENSUS SUPPORTS POPS NEAR 30 PERCENT EXTREME NORTH TO
10 TO 20 PERCENT SOUTH LATER THIS AFTERNOON. THE TOP-DOWN METHOD
RUN ON BOTH THE NAM AND GFS CONFINE PATCHES OF MIXING RAIN AND
SNOW CLOSE TO THE NORTH CAROLINA BORDER. HOWEVER...WE INCLUDED A
RAIN AND SNOW MIX FARTHER SOUTH THAN INDICATED BY THE MODELS BASED
ON THE WET BULB POTENTIAL COOLING ASSOCIATED WITH THE SURFACE
RIDGE. FORECASTED SNOW POSSIBLE JUST NORTH AND WEST OF COLUMBIA.
NO SIGNIFICANT IMPACTS ARE EXPECTED BECAUSE OF LIGHT AMOUNTS AND
MARGINAL TEMPERATURES. LOWERED AFTERNOON HIGHS A BIT DUE TO A
COLD START...CLOUDINESS...AND THE EVAPORATIVE COOLING POTENTIAL.
MOISTURE WILL FURTHER DIMINISH BEHIND THE MID-LEVEL SHORTWAVE TROUGH
THIS EVENING. THE NAM AND GFS TIME-HEIGHT DISPLAYS INDICATE
LINGERING LOW-LEVEL MOISTURE BELOW THE SNOW-GROWTH ZONE. FORECASTED
A SLIGHT RAIN CHANCE IN THE EVENING BASED ON THE HRRR AND SPC
WRF. LITTLE CONVERGENCE WILL BE ASSOCIATED WITH THE COLD FRONT
LATE. THE PREVIOUS NAM MOS INDICATED A 40 PERCENT POP IN THE
SOUTH PART LATE TONIGHT ASSOCIATED WITH THE FRONT AND AHEAD OF A
MID-LEVEL SHORTWAVE TROUGH...WITH THE LATEST NAM MOS INDICATING
MUCH LOWER POPS. WILL KEEP A SMALL POP IN THE SOUTH PART FOR
TONIGHT. BOTH THE NAM AND GFS HAVE SURFACE WET-BULB TEMPERATURES
ABOVE FREEZING IN THE SOUTH PART DURING THE PRECIPITATION CHANCE
TIME INDICATED BY THE NAM. USED THE GUIDANCE CONSENSUS FOR THE
TEMPERATURE FORECAST.
&&
.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
LOW PRESSURE OVER TEXAS THURSDAY MORNING WILL LIFT NORTHEAST
ACROSS THE LOWER MS RIVER VALLEY THROUGH THURSDAY NIGHT. ITS
ASSOCIATED WARM FROM WILL REMAIN SOUTH OF THE CSRA. INCREASING
ISENTROPIC LIFT AHEAD OF THE WARM FRONT WILL SPREAD RAIN INTO THE
AREA...MAINLY AFFECTING THE CSRA AND WESTERN MIDLANDS DURING THE
DAY WITH RAIN CHANCES INCREASING THURSDAY NIGHT AS THE LOW
PRESSURE SYSTEM LIFTS NORTHEAST.
MODELS INDICATE WEAK IN-SITU COLD AIR DAMMING DEVELOPING ACROSS
THE NORTH AND CENTRAL MIDLANDS THURSDAY NIGHT. TEMPERATURES MAY
BE NEAR FREEZING ACROSS PORTIONS OF LANCASTER AND CHESTERFIELD
COUNTIES. THE NAM AND ECMWF MODELS ARE COLDER THAN THE GFS IN THE
1000 MB TO 850 THICKNESS ACROSS THE NORTH MIDLANDS FRIDAY. SREF
SHOW LOW PROBABILITIES FOR FREEZING RAIN IN THAT REGION. WILL
MENTION A SLIGHT CHANCE FREEZING RAIN FOR FRIDAY MORNING. THIS
REMAINS A LOW CONFIDENCE FORECAST.
WENT NEAR GUIDANCE CONSENSUS FOR HIGH TEMPERATURES ON THURSDAY
RANGING FROM THE MID 40S NORTH TO AROUND 50 SOUTH. LOWS ARE
EXPECTED TO BE IN THE LOWER 30S NORTH TO THE MID 40S SOUTH.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
MODELS ARE IN FAIRLY GOOD AGREEMENT AND CONTINUE TO COME TOWARD A
CONSENSUS WITH THE LOW PRESSURE SYSTEM CROSSING THE AREA FRIDAY
THROUGH SATURDAY. THE GFS IS SLIGHTLY FASTER THAN THE ECMWF.
THE STORM SYSTEM WILL TRACK ACROSS THE REGION FRIDAY PROVIDING
WIDESPREAD PRECIPITATION. THE AREA OF LOW PRESSURE SHOULD MOVE
EAST OF THE MIDLANDS FRIDAY NIGHT THEN TURN NORTHEASTWARD AND
MOVE ALONG TO THE MID ATLANTIC COAST SATURDAY. AS LOW PRESSURE
SYSTEM DEEPENS OFF THE NC/VA COAST LATE FRIDAY NIGHT...PARTIAL
THICKNESS SCHEMES SUGGEST WINTRY PRECIPITATION POSSIBLE ACROSS THE
NORTHERN AND WESTERN MIDLANDS AS WELL AS THE PIEDMONT...ALTHOUGH
MOISTURE MAY BE SHALLOW. ALTHOUGH QPF VALUES WILL BE LOW HAVE
REMAINED WITH THE POTENTIAL RAIN/SNOW MIXTURE ASSOCIATED WITH WRAP
AROUND MOISTURE. UNCERTAINTY REMAINS QUITE HIGH. HIGH PRESSURE AND
DRIER AIR WILL RETURN TO THE REGION FOR SUNDAY AND MONDAY WITH THE
NEXT LOW PRESSURE SYSTEM WILL PUSH A COLD FRONT TOWARD THE AREA
MONDAY NIGHT.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
EXPECT VFR CONDITIONS THROUGH THE TAF PERIOD. THE DRY SURFACE
PRESSURE RIDGE WILL CONTINUE TO EXTEND INTO THE AREA. A MID-LEVEL
SHORTWAVE TROUGH WILL HELP SUPPORT VFR CEILINGS THIS AFTERNOON
INTO TONIGHT. THERE MAY ALSO BE A PERIOD OF SPRINKLES LATE THIS
AFTERNOON INTO THE EVENING. THE HRRR CONTINUES TO DISPLAY A
DIMINISHING AREA OF PRECIPITATION MOVING INTO THE AREA FROM THE
WEST DURING THAT TIME ASSOCIATED WITH THE UPPER-LEVEL FEATURE.
HOWEVER...ALL THE GFS AND NAM MOS PLUS SREF GUIDANCE INDICATE VFR
CONDITIONS AND BELIEVE THIS IS REASONABLE BASED ON THE DRY NEAR-
SURFACE LAYER ASSOCIATED WITH THE RIDGE. WINDS WILL BE LIGHT WITH
THE RIDGE AXIS NEAR THE AREA...BUT BE MAINLY SOUTHWEST THIS
AFTERNOON WITH THE AXIS JUST EAST OF THE AREA.
EXTENDED AVIATION OUTLOOK....A LOW PRESSURE SYSTEM MAY BRING
WIDESPREAD MVFR OR IFR CONDITIONS THURSDAY THROUGH SATURDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
623 AM EST WED JAN 20 2016
.SYNOPSIS...
THE SURFACE PRESSURE RIDGE WILL REMAIN NEAR THE FORECAST AREA
THROUGH TODAY AND HELP LIMIT MOISTURE ASSOCIATED WITH AN UPPER-
LEVEL DISTURBANCE MOVING INTO THE AREA THIS AFTERNOON. MOISTURE
WILL INCREASE THURSDAY AHEAD OF LOW PRESSURE APPROACHING FROM THE
WEST. THE LOW WILL CROSS THE AREA FRIDAY INTO FRIDAY NIGHT.
DRY HIGH PRESSURE WILL RETURN FOR SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE SURFACE RIDGE IN THE FORECAST AREA THIS MORNING WILL BE NEAR
THE COAST THIS AFTERNOON. THE RIDGE AND H85 WESTERLY FLOW WILL
LIMIT MOISTURE ASSOCIATED WITH THE MID-LEVEL SHORTWAVE TROUGH
MOVING INTO THE FORECAST AREA. THE HRRR...ARW AND SPC WRF
INDICATE PRECIPITATION DIMINISHING AS IT MOVES INTO THE AREA
FROM THE WEST LATE THIS AFTERNOON INTO THE EVENING. EXPECT MUCH OF
THE FORECAST AREA WILL HAVE A PERIOD OF SPRINKLES BUT THE CHANCE
OF MEASURABLE PRECIPITATION SHOULD BE LOW. THE GFS AND NAM PLUS
SREF GUIDANCE DISPLAY PRECIPITATION AMOUNTS OF 0.01 OF AN INCH OR
LESS. THE GUIDANCE CONSENSUS SUPPORTS POPS NEAR 30 PERCENT EXTREME
NORTH TO 10 TO 20 PERCENT SOUTH. THE TOP-DOWN METHOD RUN ON BOTH
THE NAM AND GFS CONFINE PATCHES OF MIXING RAIN AND SNOW CLOSE TO
THE NORTH CAROLINA BORDER. HOWEVER...WE INCLUDED A RAIN AND SNOW
MIX FARTHER SOUTH THAN INDICATED BY THE MODELS BASED ON THE WET
BULB POTENTIAL COOLING ASSOCIATED WITH THE SURFACE RIDGE.
FORECASTED SNOW POSSIBLE JUST NORTH AND WEST OF COLUMBIA. NO
SIGNIFICANT IMPACTS ARE EXPECTED BECAUSE OF LIGHT AMOUNTS AND
MARGINAL TEMPERATURES. THE GUIDANCE TEMPERATURES ARE LIKELY TOO
HIGH TODAY BECAUSE OF A COLD START...CLOUDINESS...AND THE EVAPORATIVE
COOLING POTENTIAL.
MOISTURE WILL FURTHER DIMINISH BEHIND THE MID-LEVEL SHORTWAVE TROUGH
THIS EVENING. THE NAM AND GFS TIME-HEIGHT DISPLAYS INDICATE
LINGERING LOW-LEVEL MOISTURE BELOW THE SNOW-GROWTH ZONE. FORECASTED
A SLIGHT RAIN CHANCE IN THE EVENING BASED ON THE HRRR AND SPC
WRF. LITTLE CONVERGENCE WILL BE ASSOCIATED WITH THE COLD FRONT
LATE. THE NAM MOS DID INDICATE A 40 PERCENT POP IN THE SOUTH PART
LATE TONIGHT ASSOCIATED WITH THE FRONT AND AHEAD OF A MID-LEVEL
SHORTWAVE TROUGH. THE GFS AND ECMWF MOS INDICATED A LOWER POP.
USED AN AVERAGE OF THE GUIDANCE AND FORECASTED A SMALL POP IN THE
SOUTH PART. BOTH THE NAM AND GFS HAVE SURFACE WET-BULB
TEMPERATURES ABOVE FREEZING IN THE SOUTH PART DURING THE
PRECIPITATION CHANCE TIME INDICATED BY THE NAM. USED THE GUIDANCE
CONSENSUS FOR THE TEMPERATURE FORECAST.
&&
.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
LOW PRESSURE OVER TEXAS THURSDAY MORNING WILL LIFT NORTHEAST
ACROSS THE LOWER MS RIVER VALLEY THROUGH THURSDAY NIGHT. ITS
ASSOCIATED WARM FROM WILL REMAIN SOUTH OF THE CSRA. INCREASING
ISENTROPIC LIFT AHEAD OF THE WARM FRONT WILL SPREAD RAIN INTO THE
AREA...MAINLY AFFECTING THE CSRA AND WESTERN MIDLANDS DURING THE
DAY WITH RAIN CHANCES INCREASING THURSDAY NIGHT AS THE LOW
PRESSURE SYSTEM LIFTS NORTHEAST.
MODELS INDICATE WEAK IN-SITU COLD AIR DAMMING DEVELOPING ACROSS
THE NORTH AND CENTRAL MIDLANDS THURSDAY NIGHT. TEMPERATURES MAY
BE NEAR FREEZING ACROSS PORTIONS OF LANCASTER AND CHESTERFIELD
COUNTIES. THE NAM AND ECMWF MODELS ARE COLDER THAN THE GFS IN THE
1000 MB TO 850 THICKNESS ACROSS THE NORTH MIDLANDS FRIDAY. SREF
SHOW LOW PROBABILITIES FOR FREEZING RAIN IN THAT REGION. WILL
MENTION A SLIGHT CHANCE FREEZING RAIN FOR FRIDAY MORNING. THIS
REMAINS A LOW CONFIDENCE FORECAST.
WENT NEAR GUIDANCE CONSENSUS FOR HIGH TEMPERATURES ON THURSDAY
RANGING FROM THE MID 40S NORTH TO AROUND 50 SOUTH. LOWS ARE
EXPECTED TO BE IN THE LOWER 30S NORTH TO THE MID 40S SOUTH.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
MODELS ARE IN FAIRLY GOOD AGREEMENT AND CONTINUE TO COME TOWARD A
CONSENSUS WITH THE LOW PRESSURE SYSTEM CROSSING THE AREA FRIDAY
THROUGH SATURDAY. THE GFS IS SLIGHTLY FASTER THAN THE ECMWF.
THE STORM SYSTEM WILL TRACK ACROSS THE REGION FRIDAY PROVIDING
WIDESPREAD PRECIPITATION. THE AREA OF LOW PRESSURE SHOULD MOVE
EAST OF THE MIDLANDS FRIDAY NIGHT THEN TURN NORTHEASTWARD AND
MOVE ALONG TO THE MID ATLANTIC COAST SATURDAY. AS LOW PRESSURE
SYSTEM DEEPENS OFF THE NC/VA COAST LATE FRIDAY NIGHT...PARTIAL
THICKNESS SCHEMES SUGGEST WINTRY PRECIPITATION POSSIBLE ACROSS THE
NORTHERN AND WESTERN MIDLANDS AS WELL AS THE PIEDMONT...ALTHOUGH
MOISTURE MAY BE SHALLOW. ALTHOUGH QPF VALUES WILL BE LOW HAVE
REMAINED WITH THE POTENTIAL RAIN/SNOW MIXTURE ASSOCIATED WITH WRAP
AROUND MOISTURE. UNCERTAINTY REMAINS QUITE HIGH. HIGH PRESSURE AND
DRIER AIR WILL RETURN TO THE REGION FOR SUNDAY AND MONDAY WITH THE
NEXT LOW PRESSURE SYSTEM WILL PUSH A COLD FRONT TOWARD THE AREA
MONDAY NIGHT.
&&
.AVIATION /11Z WEDNESDAY THROUGH SUNDAY/...
EXPECT VFR CONDITIONS THROUGH THE TAF PERIOD. THE DRY SURFACE
PRESSURE RIDGE WILL CONTINUE TO EXTEND INTO THE AREA. A MID-LEVEL
SHORTWAVE TROUGH WILL HELP SUPPORT VFR CEILINGS THIS AFTERNOON
INTO TONIGHT. THERE MAY ALSO BE A PERIOD OF SPRINKLES LATE THIS
AFTERNOON INTO THE EVENING. THE ARW...HRRR...AND SPC WRF DISPLAY
A DIMINISHING AREA OF PRECIPITATION MOVING INTO THE AREA FROM THE
WEST DURING THAT TIME ASSOCIATED WITH THE UPPER-LEVEL FEATURE.
HOWEVER...ALL THE GFS AND NAM MOS PLUS SREF GUIDANCE INDICATE VFR
CONDITIONS AND BELIEVE THIS IS REASONABLE BASED ON THE DRY NEAR-
SURFACE LAYER ASSOCIATED WITH THE RIDGE. WINDS WILL BE LIGHT WITH
THE RIDGE AXIS NEAR THE AREA...BUT BE MAINLY SOUTHWEST THIS
AFTERNOON WITH THE AXIS JUST EAST OF THE AREA. USED THE GFS LAMP
FOR THE WIND FORECAST.
EXTENDED AVIATION OUTLOOK....A LOW PRESSURE SYSTEM MAY BRING
WIDESPREAD MVFR OR IFR CONDITIONS THURSDAY THROUGH SATURDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
&&
$$
SYNOPSIS...99
NEAR TERM...99
SHORT TERM...99
LONG TERM...99
AVIATION...99
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
423 AM EST WED JAN 20 2016
.SYNOPSIS...
THE SURFACE PRESSURE RIDGE WILL REMAIN NEAR THE FORECAST AREA
THROUGH TODAY AND HELP LIMIT MOISTURE ASSOCIATED WITH AN UPPER-
LEVEL DISTURBANCE MOVING INTO THE AREA THIS AFTERNOON. MOISTURE
WILL INCREASE THURSDAY AHEAD OF LOW PRESSURE APPROACHING FROM THE
WEST. THE LOW WILL CROSS THE AREA FRIDAY INTO FRIDAY NIGHT.
DRY HIGH PRESSURE WILL RETURN FOR SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE SURFACE RIDGE IN THE FORECAST AREA THIS MORNING WILL BE NEAR
THE COAST THIS AFTERNOON. THE RIDGE AND H85 WESTERLY FLOW WILL
LIMIT MOISTURE ASSOCIATED WITH THE MID-LEVEL SHORTWAVE TROUGH
MOVING INTO THE FORECAST AREA. THE HRRR...ARW AND SPC WRF
INDICATE PRECIPITATION DIMINISHING AS IT MOVES INTO THE FORECAST
AREA FROM THE WEST LATE THIS AFTERNOON INTO THE EVENING. EXPECT
MUCH OF THE FORECAST AREA WILL HAVE A PERIOD OF SPRINKLES BUT THE
CHANCE OF MEASURABLE PRECIPITATION SHOULD BE LOW. THE GFS AND NAM
PLUS SREF GUIDANCE DISPLAY PRECIPITATION AMOUNTS OF 0.01 OF AN
INCH OR LESS. THE GUIDANCE CONSENSUS SUPPORTS POPS NEAR 30 PERCENT
EXTREME NORTH TO 10 TO 20 PERCENT SOUTH. THE TOP-DOWN METHOD RUN
ON BOTH THE NAM AND GFS CONFINE PATCHES OF MIXING RAIN AND SNOW
CLOSE TO THE NORTH CAROLINA BORDER. HOWEVER...WE INCLUDED A RAIN
AND SNOW MIX FARTHER SOUTH THAN INDICATED BY THE MODELS BASED ON
THE WET BULB POTENTIAL COOLING ASSOCIATED WITH THE SURFACE RIDGE.
FORECASTED SNOW POSSIBLE JUST NORTH AND WEST OF COLUMBIA. NO
SIGNIFICANT IMPACTS ARE EXPECTED AT THIS TIME BECAUSE OF LIGHT
AMOUNTS AND MARGINAL TEMPERATURES. THE GUIDANCE TEMPERATURES ARE
LIKELY TOO HIGH TODAY BECAUSE OF A COLD START...CLOUDINESS...AND
EVAPORATIVE COOLING POTENTIAL.
MOISTURE WILL FURTHER DIMINISH BEHIND THE MID-LEVEL SHORTWAVE TROUGH
THIS EVENING. THE NAM AND GFS TIME-HEIGHT DISPLAYS INDICATE
LINGERING LOW-LEVEL MOISTURE BELOW THE SNOW-GROWTH ZONE. FORECASTED
A SLIGHT RAIN CHANCE IN THE EVENING BASED ON THE HRRR AND SPC
WRF. LITTLE CONVERGENCE WILL BE ASSOCIATED WITH THE COLD FRONT
LATE. THE NAM MOS DID INDICATE A SMALL POP IN THE SOUTH PART LATE
TONIGHT ASSOCIATED WITH THE FRONT AND AHEAD OF A MID-LEVEL
SHORTWAVE TROUGH. THE GFS AND ECMWF INDICATED A LOWER POP. USED AN
AVERAGE OF THE GUIDANCE AND FORECASTED A SMALL POP IN THE SOUTH
PART. BOTH THE NAM AND GFS HAVE SURFACE WET-BULB TEMPERATURES
ABOVE FREEZING IN THE SOUTH PART DURING THE PRECIPITATION CHANCE
TIME INDICATED BY THE NAM. USED THE GUIDANCE CONSENSUS FOR THE
TEMPERATURE FORECAST.
&&
.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
LOW PRESSURE OVER TEXAS THURSDAY MORNING WILL LIFT NORTHEAST
ACROSS THE LOWER MS RIVER VALLEY THROUGH THURSDAY NIGHT. ITS
ASSOCIATED WARM FROM WILL REMAIN SOUTH OF THE CSRA. INCREASING
ISENTROPIC LIFT AHEAD OF THE WARM FRONT WILL SPREAD RAIN INTO THE
AREA...MAINLY AFFECTING THE CSRA AND WESTERN MIDLANDS DURING THE
DAY WITH RAIN CHANCES INCREASING THURSDAY NIGHT AS THE LOW
PRESSURE SYSTEM LIFTS NORTHEAST.
MODELS INDICATE WEAK IN-SITU COLD AIR DAMMING DEVELOPING ACROSS
THE NORTH AND CENTRAL MIDLANDS THURSDAY NIGHT. TEMPERATURES MAY
BE NEAR FREEZING ACROSS PORTIONS OF LANCASTER AND CHESTERFIELD
COUNTIES. THE NAM AND ECMWF MODELS ARE COLDER THAN THE GFS IN THE
1000 MB TO 850 THICKNESS ACROSS THE NORTH MIDLANDS FRIDAY. SREF
SHOW LOW PROBABILITIES FOR FREEZING RAIN IN THAT REGION. WILL
MENTION A SLIGHT CHANCE FREEZING RAIN FOR FRIDAY MORNING. THIS
REMAINS A LOW CONFIDENCE FORECAST.
WENT NEAR GUIDANCE CONSENSUS FOR HIGH TEMPERATURES ON THURSDAY
RANGING FROM THE MID 40S NORTH TO AROUND 50 SOUTH. LOWS ARE
EXPECTED TO BE IN THE LOWER 30S NORTH TO THE MID 40S SOUTH.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
MODELS ARE IN FAIRLY GOOD AGREEMENT AND CONTINUE TO COME TOWARD A
CONSENSUS WITH THE LOW PRESSURE SYSTEM CROSSING THE AREA FRIDAY
THROUGH SATURDAY. THE GFS IS SLIGHTLY FASTER THAN THE ECMWF.
THE STORM SYSTEM WILL TRACK ACROSS THE REGION FRIDAY PROVIDING
WIDESPREAD PRECIPITATION. THE AREA OF LOW PRESSURE SHOULD MOVE
EAST OF THE MIDLANDS FRIDAY NIGHT THEN TURN NORTHEASTWARD AND
MOVE ALONG TO THE MID ATLANTIC COAST SATURDAY. AS LOW PRESSURE
SYSTEM DEEPENS OFF THE NC/VA COAST LATE FRIDAY NIGHT...PARTIAL
THICKNESS SCHEMES SUGGEST WINTRY PRECIPITATION POSSIBLE ACROSS THE
NORTHERN AND WESTERN MIDLANDS AS WELL AS THE PIEDMONT...ALTHOUGH
MOISTURE MAY BE SHALLOW. ALTHOUGH QPF VALUES WILL BE LOW HAVE
REMAINED WITH THE POTENTIAL RAIN/SNOW MIXTURE ASSOCIATED WITH WRAP
AROUND MOISTURE. UNCERTAINTY REMAINS QUITE HIGH. HIGH PRESSURE AND
DRIER AIR WILL RETURN TO THE REGION FOR SUNDAY AND MONDAY WITH THE
NEXT LOW PRESSURE SYSTEM WILL PUSH A COLD FRONT TOWARD THE AREA
MONDAY NIGHT.
&&
.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
EXPECT VFR CONDITIONS THROUGH THE TAF PERIOD. THE DRY SURFACE
PRESSURE RIDGE WILL CONTINUE TO EXTEND INTO THE AREA. A MID-LEVEL
SHORTWAVE TROUGH MAY HELP SUPPORT VFR CEILINGS THIS AFTERNOON INTO
TONIGHT. THERE MAY ALSO BE A PERIOD OF SPRINKLES LATE THIS
AFTERNOON INTO THE EVENING. THE ARW AND SPC WRF DISPLAY A
DIMINISHING AREA OF PRECIPITATION MOVING INTO THE AREA FROM THE
WEST DURING THAT TIME ASSOCIATED WITH THE UPPER-LEVEL FEATURE.
HOWEVER...ALL THE GFS AND NAM MOS PLUS SREF GUIDANCE INDICATE VFR
CONDITIONS AND BELIEVE THIS IS REASONABLE BASED ON THE DRY NEAR-
SURFACE LAYER ASSOCIATED WITH THE RIDGE. WINDS WILL BE LIGHT WITH
THE RIDGE AXIS NEAR THE AREA...BUT BE MAINLY SOUTHWEST THIS
AFTERNOON WITH THE AXIS JUST EAST OF THE AREA. USED THE GFS LAMP
FOR THE WIND FORECAST.
EXTENDED AVIATION OUTLOOK....A LOW PRESSURE SYSTEM MAY BRING
WIDESPREAD MVFR OR IFR CONDITIONS THURSDAY THROUGH SATURDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
308 AM EST WED JAN 20 2016
.SYNOPSIS...
THE SURFACE PRESSURE RIDGE WILL REMAIN NEAR THE FORECAST AREA
THROUGH TODAY AND HELP LIMIT MOISTURE ASSOCIATED WITH AN UPPER-
LEVEL DISTURBANCE MOVING INTO THE AREA THIS AFTERNOON. A WEAK COLD
FRONT WILL MOVE INTO THE AREA LATE TONIGHT. MOISTURE WILL INCREASE
THURSDAY AHEAD OF LOW PRESSURE APPROACHING FROM THE WEST. THE LOW
WILL BE NEAR THE FORECAST AREA FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE SURFACE RIDGE IN THE FORECAST AREA THIS MORNING WILL BE NEAR
THE COAST THIS AFTERNOON. THE RIDGE AND H85 WESTERLY FLOW WILL
LIMIT MOISTURE ASSOCIATED WITH THE MID-LEVEL SHORTWAVE TROUGH
MOVING INTO THE FORECAST AREA. THE HRRR...ARW AND SPC WRF
INDICATE PRECIPITATION DIMINISHING AS IT MOVES INTO THE FORECAST
AREA FROM THE WEST LATE THIS AFTERNOON INTO THE EVENING. EXPECT
MUCH OF THE FORECAST AREA WILL HAVE A PERIOD OF SPRINKLES BUT THE
CHANCE OF MEASURABLE PRECIPITATION SHOULD BE LOW. THE GFS AND NAM
PLUS SREF GUIDANCE DISPLAY PRECIPITATION AMOUNTS OF 0.01 OF AN
INCH OR LESS. THE GUIDANCE CONSENSUS SUPPORTS POPS NEAR 30 PERCENT
EXTREME NORTH TO 10 TO 20 PERCENT SOUTH. THE TOP-DOWN METHOD RUN
ON BOTH THE NAM AND GFS CONFINE PATCHES OF MIXING RAIN AND SNOW
CLOSE TO THE NORTH CAROLINA BORDER. HOWEVER...WE INCLUDED A RAIN
AND SNOW MIX FARTHER SOUTH THAN INDICATED BY THE MODELS BASED ON
THE WET BULB POTENTIAL COOLING ASSOCIATED WITH THE SURFACE RIDGE.
FORECASTED SNOW POSSIBLE JUST NORTH AND WEST OF COLUMBIA. NO
SIGNIFICANT IMPACTS ARE EXPECTED AT THIS TIME BECAUSE OF LIGHT
AMOUNTS AND MARGINAL TEMPERATURES. THE GUIDANCE TEMPERATURES ARE
LIKELY TOO HIGH TODAY BECAUSE OF A COLD START...CLOUDINESS...AND
EVAPORATIVE COOLING POTENTIAL.
MOISTURE WILL FURTHER DIMINISH BEHIND THE MID-LEVEL SHORTWAVE TROUGH
THIS EVENING. THE NAM AND GFS TIME-HEIGHT DISPLAYS INDICATE
LINGERING LOW-LEVEL MOISTURE BELOW THE SNOW-GROWTH ZONE. FORECASTED
A SLIGHT RAIN CHANCE IN THE EVENING BASED ON THE HRRR AND SPC
WRF. LITTLE CONVERGENCE WILL BE ASSOCIATED WITH THE COLD FRONT
LATE. THE NAM MOS DID INDICATE A SMALL POP IN THE SOUTH PART LATE
TONIGHT ASSOCIATED WITH THE FRONT AND AHEAD OF A MID-LEVEL
SHORTWAVE TROUGH. THE GFS AND ECMWF INDICATED A LOWER POP. USED AN
AVERAGE OF THE GUIDANCE AND FORECASTED A SMALL POP IN THE SOUTH
PART. BOTH THE NAM AND GFS HAVE SURFACE WET-BULB TEMPERATURES
ABOVE FREEZING IN THE SOUTH PART DURING THE PRECIPITATION CHANCE
TIME INDICATED BY THE NAM. USED THE GUIDANCE CONSENSUS FOR THE
TEMPERATURE FORECAST.
&&
.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
THE LOW WILL MARCH EASTWARD WITH A WARM FRONT MOVING INTO THE
AREA THURSDAY LATE MORNING WITH INCREASING CHANCES OF RAIN THROUGH
THE AFTERNOON. AS THE SYSTEM MOVES INTO THE CENTRAL GULF STATES
THURSDAY NIGHT CHANCES OF RAIN WILL CONTINUE INCREASING. THURSDAY
NIGHT THERE MAY BE WEAK IN-SITU COLD AIR DAMMING DEVELOPING ACROSS
THE NORTH AND CENTRAL MIDLANDS. TEMPERATURES MAY BE NEAR FREEZING
ACROSS THE NORTHERN MIDLANDS. THE NAM AND ECMWF MODELS ARE COLDER
THAN THE GFS IN THE 1000 MB TO 850 THICKNESS ACROSS THE NORTH
MIDLANDS FRIDAY. SREF PRECIP TYPE PROBABILITIES FOR FREEZING RAIN
ARE MODERATELY HIGH IN THAT REGION. WILL MENTION A SLIGHT CHANCE
FREEZING RAIN FOR FRIDAY MORNING AT THIS TIME AND LOWER
TEMPERATURES FOR THURSDAY/FRIDAY TIME FRAME DUE TO POSSIBLE WEDGE
DEVELOPMENT IN THAT REGION. CONFIDENCE REMAINS LOW.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
MODELS ARE IN GOOD AGREEMENT AND CONTINUE TO COME TOWARD A
CONSENSUS WITH THE LOW PRESSURE SYSTEM CROSSING THE AREA FRIDAY
THROUGH SATURDAY. MODELS STILL DIFFER SLIGHTLY WITH THE TRACK OF
THIS SYSTEM AND HAVE CONTINUED TO TREND TOWARD A CONSENSUS WITH
THE LOW MOVING EASTWARD THROUGH THE DAY FRIDAY AND OFFSHORE OF NC
FRIDAY NIGHT. THE SYSTEM WILL THEN TURN NORTHEASTWARD AND MOVE
ALONG THE COAST SATURDAY. AS LOW PRESSURE SYSTEM DEEPENS OFF THE
NC/VA COAST LATE FRIDAY NIGHT...PARTIAL THICKNESS SCHEMES SUGGEST
WINTRY PRECIPITATION POSSIBLE ACROSS THE NORTHERN AND WESTERN
MIDLANDS AS WELL AS THE PIEDMONT...ALTHOUGH MOISTURE MAY BE
SHALLOW. ALTHOUGH QPF VALUES WILL BE LOW HAVE REMAINED WITH THE
POTENTIAL RAIN/SNOW MIXTURE ASSOCIATED WITH WRAP AROUND MOISTURE.
UNCERTAINTY REMAINS QUITE HIGH. HIGH PRESSURE AND DRIER AIR WILL
RETURN TO THE REGION FOR SUNDAY AND MONDAY WITH THE NEXT LOW
PRESSURE SYSTEM WILL PUSH A COLD FRONT TOWARD THE AREA MONDAY
NIGHT.
&&
.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
EXPECT VFR CONDITIONS THROUGH THE TAF PERIOD. THE DRY SURFACE
PRESSURE RIDGE WILL CONTINUE TO EXTEND INTO THE AREA. A MID-LEVEL
SHORTWAVE TROUGH MAY HELP SUPPORT VFR CEILINGS THIS AFTERNOON INTO
TONIGHT. THERE MAY ALSO BE A PERIOD OF SPRINKLES LATE THIS
AFTERNOON INTO THE EVENING. THE ARW AND SPC WRF DISPLAY A
DIMINISHING AREA OF PRECIPITATION MOVING INTO THE AREA FROM THE
WEST DURING THAT TIME ASSOCIATED WITH THE UPPER-LEVEL FEATURE.
HOWEVER...ALL THE GFS AND NAM MOS PLUS SREF GUIDANCE INDICATE VFR
CONDITIONS AND BELIEVE THIS IS REASONABLE BASED ON THE DRY NEAR-
SURFACE LAYER ASSOCIATED WITH THE RIDGE. WINDS WILL BE LIGHT WITH
THE RIDGE AXIS NEAR THE AREA...BUT BE MAINLY SOUTHWEST THIS
AFTERNOON WITH THE AXIS JUST EAST OF THE AREA. USED THE GFS LAMP
FOR THE WIND FORECAST.
EXTENDED AVIATION OUTLOOK....A LOW PRESSURE SYSTEM MAY BRING
WIDESPREAD MVFR OR IFR CONDITIONS THURSDAY THROUGH SATURDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
&&
$$
SYNOPSIS...99
NEAR TERM...99
SHORT TERM...99
LONG TERM...99
AVIATION...99
AREA FORECAST DISCUSSION...UPDATED
NWS CHICAGO/ROMEOVILLE IL
921 PM CST THU JAN 21 2016
.UPDATE...
920 PM CST
THE GOING FORECAST FOR TONIGHT IS IN GENERALLY GOOD SHAPE AND
CONTINUE TO ASSESS LAKE EFFECT SNOW SHOWER COVERAGE AND INTENSITY
FOR FRIDAY MORNING...NEITHER OF WHICH LOOK IMPRESSIVE...ALTHOUGH
THE TIMING OF A WEEKDAY MORNING COMMUTE CAN LOWER THRESHOLDS FOR
IMPACTS.
THE LOW-LEVEL RIDGE AXIS DRAPED FROM WEST TO EAST OVER THE
FORECAST AREA HAS STRENGTHENED THIS EVENING NOW AVERAGING AROUND
1030MB. THE 850-925MB BAROCLINIC ZONE IS DEVELOPING SOUTHWARD OVER
THE LAKE...THOUGH THE COLD ADVECTION PUSH IS NOT PARTICULARLY
STRONG...AND LAKE EFFECT SHOWERS ARE PRESENTLY LOOSELY DEFINED
OVER THE NORTHERN PART OF THE LAKE. THE 00Z APX SOUNDING INDICATED
AN INVERSION HEIGHT AROUND 7500 FT OVER NORTHERN LOWER MICHIGAN
WHICH CAN BE INFERRED OVER THE NORTHERN PART OF THE LAKE RIGHT
NOW...ALTHOUGH THIS WILL LIKELY MODIFY SOME AS IT ADVANCES
SOUTHWARD. BOTH THE RAP AND NAM SEEMED TO ANALYZE WELL WITH WHAT
WAS GOING ON UPSTREAM AND HAVE INVERSION HEIGHTS AROUND 4500-5000
FT OVER THE FAR SOUTHWEST PART OF THE LAKE FRIDAY MORNING. BESIDES
LIMITING THE OVERALL INSTABILITY AND VERTICAL MOTION FOR MODERATE-
HEAVY SNOW...THIS FAIRLY LOW INVERSION HEIGHT ALSO APPEARS TO KEEP
THE TEMPERATURE PROFILES SATURATED ONLY AS COOL AS -10C...WHICH IS
NOT OPTIMUM FOR SNOW GROWTH. THERE STILL IS ENOUGH SUPPORT FOR
MAINLY LIGHT SNOW SHOWERS HOWEVER ESPECIALLY GIVEN THE CONVERGENCE
SET TO DEVELOP ACROSS THE WESTERN PART OF THE LAKE AS THE LOW
PRESSURE OVER THE LOWER MISSISSIPPI VALLEY LIFTS NORTH AND BENDS
THE PRESSURE FIELD.
SO CONTINUE THE TRENDS AS IS WITH JUST MINOR ADJUSTMENTS IN HOURLY
FORECAST PARAMETERS. THE PRIMARY TIME FOR LIGHT LAKE EFFECT SNOW
IN DOWNTOWN CHICAGO APPEARS TO BE BETWEEN 7 AM AND NOON...WHILE IN
LAKE COUNTY ILLINOIS APPEARS TO BE BETWEEN 9 AM AND 3 PM. WITH
THE MARGINAL INTENSITY EXPECTED AND AIR TEMPERATURES EXPECTED TO
BE IN THE MID TO POSSIBLY UPPER 20S...THINK IMPACTS WILL OVERALL
STILL BE MINIMAL...WITH ACCUMULATION PRIMARILY OF A FEW TENTHS OR
LESS...WITH EASTERN LAKE COUNTY AND IMMEDIATE LAKE SIDE AREAS
POSSIBLY A LITTLE HIGHER BY LATE MORNING.
MTF
&&
.SHORT TERM...
157 PM CST
THROUGH FRIDAY...
TONIGHT...
FAIRLY QUIET CONDITIONS ARE IN PLACE THIS AFTERNOON AS A BROAD AREA
OF SURFACE HIGH PRESSURE HOLDS ON THE NORTH SIDE OF CLOSED UPPER
LEVEL LOW PRESSURE. TEMPERATURES ARE STILL SLIGHTLY BELOW NORMAL
WITH LIGHT WINDS. SOME MID LEVEL MOISTURE AHEAD OF THE NORTHERN
STREAM SHORTWAVE WILL APPROACH THE AREA FROM THE WEST
TONIGHT...THOUGH ANY FLURRIES WILL LIKELY REMAIN TO OUR WEST/NORTH.
TEMPERATURES SHOULD HOLD A BIT HIGHER TONIGHT AS A MIX OF MID AND
UPPER CLOUDS KEEP READINGS INTO THE UPPER TEENS MANY LOCATIONS TO
THE 20S IN THE CITY.
FRIDAY...
THE LARGE MID-UPPER LEVEL LOW TO OUR SOUTH...THE ONE THAT WILL BRING
SNOW TO PORTIONS OF THE EAST COAST...WILL TRANSLATE ACROSS THE
EASTERN HALF OF THE UNITED STATES. WEAKER ENERGY ON THE NORTH SIDE
OF THIS SYSTEM WILL TRANSLATE ACROSS NORTHEAST ILLINOIS AND
NORTHWEST INDIANA THROUGH THE DAY. THE CLOSED LOW EXTENDING TO THE
SURFACE...LOW LEVEL WINDS TURN NORTHEASTERLY CREATING A SETUP FOR
LAKE EFFECT SNOW SHOWERS...MOST FAVORED IN THE MORNING TO EARLY
AFTERNOON. PARAMETERS FAVORABLE INCLUDE MARGINALLY STEEP LAPSE RATES
ALONG WITH IN EXCESS OF 100 J/KG OF LAKE INDUCED CAPE...A PERIOD OF
LOW LEVEL CONVERGENCE COUPLED WITH THE UPPER WAVE RESULTING IN
MODEST LOWER LEVEL OMEGA. NEGATIVE FACTORS INCLUDE A VERY NARROW
AXIS OF SATURATION IN THE DENDRITIC GROWTH REGION AT THE TOP OF THE
SATURATED LAYER AND A SEMI-PROGRESSIVE CONVERGENCE AXIS SUGGESTING
SHOWERS WILL NOT LINGER. WE DO CARRY SOME LIKELY POPS FROM CHICAGO
NORTHWARD INTO LAKE COUNTY AS WE FEEL THERE WILL BE SOME LAKE EFFECT
SHOWERS AROUND WITH SOME LIGHT ACCUMULATIONS WHERE THEY OCCUR...BUT
KEPT CHANCE MENTIONS OR FLURRIES ELSEWHERE DUE TO THESE NEGATIVE
FACTORS. RAW GUIDANCE SUGGESTS A FEW TENTHS AT BEST...COULD BE
LOCALLY SLIGHTLY HIGHER WHERE SHOWERS SET UP WITH NOT EVERYWHERE
ACCUMULATING...TYPICAL OF MARGINAL LAKE EFFECT SCENARIOS. STILL CAN
MAKE FOR SOME LOCALLY SLICK ROADS. OTHERWISE EXPECT LAKE CLOUDS AND
TEMPS IN THE MID TO UPPER 20S...STILL SLIGHTLY COOLER THAN NORMAL.
KMD
&&
.LONG TERM...
258 PM CST
FRIDAY NIGHT THROUGH THURSDAY...
MAIN FORECAST CONCERNS/CHALLENGES ARE WITH LINGERING LAKE EFFECT
SNOW SHOWERS FRIDAY EVENING...AND THEN WINTRY MIX/SNOW BECOMING
MORE PROBABLE MONDAY AND MONDAY NIGHT.
SCATTERED LAKE EFFECT SNOW SHOWERS MAY STILL BE OCCURRING ACROSS
A PORTION OF FAR NORTHEAST ILLINOIS...PRIMARILY COOK/LAKE
COUNTIES...FRIDAY EVENING. NORTHEAST FLOW OFF OF THE LAKE WITH
PARAMETERS BECOMING SLIGHTLY MORE FAVORABLE FOR DEVELOPMENT WILL
OCCUR DURING THIS PERIOD AND HAVE MADE LITTLE CHANGES TO THE
SLIGHT CHANCE/CHANCE POPS DURING THIS TIME. ANY ACCUMULATION WILL
BE ISOLATED AND LIGHT...WITH AT MOST A TRACE UP TO A COUPLE OF
TENTHS OF AN INCH POSSIBLE. ANY REMAINING SNOW SHOWERS WILL
DIMINISH OVERNIGHT INTO SATURDAY MORNING. MAINTAINED A DRY
FORECAST FOR SATURDAY MORNING...BUT COULD SEE SOME FLURRIES
POSSIBLY STILL COMING OFF THE LAKE FOR A TIME. HOWEVER...RIDGING
ALOFT AND EASTWARD BUILDING HIGH PRESSURE WILL LIMIT ANY FURTHER
DEVELOPMENT INTO SATURDAY. SKIES WILL LIKELY BE SCATTERING ON
SATURDAY WHILE WARMING OCCURS ALOFT. THIS COINCIDING WITH RATHER
LIGHT WINDS SHOULD ALLOW FOR A RELATIVELY PLEASANT DAY ON
SATURDAY. DRY CONDITIONS AND WARMING WILL CONTINUE THROUGH THE END
OF THE WEEKEND WITH TEMPS IN THE MID TO UPPER 30S EXPECTED SUNDAY.
CLOUD COVER WILL BE INCREASING SUNDAY AND SUNDAY NIGHT IN ADVANCE
OF THE NEXT SYSTEM TO IMPACT THE REGION. GUIDANCE FAIRLY
CONSISTENT IN SHOWING A FAIRLY ENERGETIC UPPER LEVEL TROUGH AND
ATTENDANT SURFACE LOW PUSHING THROUGH THE PLAINS AND MID
MISSISSIPPI VALLEY SUNDAY INTO MONDAY. PRECIP CHANCES WILL BE
INCREASING FROM WEST TO EAST OVER THE CWA ON MONDAY AS THIS SYSTEM
APPROACHES...WITH SOME CONCERNS FOR POSSIBLE VARYING PRECIP TYPE
REMAINING. DEEPER MOISTURE DOES NOT APPEAR TO BE PRESENT ACROSS
THE CWA INITIALLY ON MONDAY AND WITH THERMAL PROFILES ALSO CLOSE
TO THE RAIN/SNOW LINE...AM A LITTLE CONCERNED FOR A PERIOD OF
FREEZING RAIN/DRIZZLE. HOWEVER...STRONGER FORCING WILL LIKELY NOT
ARRIVE UNTIL LATER IN THE DAY...WITH SURFACE TEMPS HAVING A DECENT
CHANCE TO RISE ABOVE FREEZING BEFORE THIS PRECIP ARRIVES. WILL
CONTINUE TO MONITOR THIS POTENTIAL BUT HAVE LEFT OUT ANY MENTION
OF FREEZING RAIN/DRIZZLE IN THE GRIDS AT THIS TIME. COLD AIR
SHOULD QUICKLY WRAP AROUND THIS SYSTEM AS IT MOVES THROUGH THE
CWA/REGION MONDAY NIGHT WITH ANY LIQUID PRECIP QUICKLY CHANGING
OVER TO ALL SNOW DURING THAT TIME. CONFIDENCE IS LOWER TO THE
EXTENT OF ANY REMAINING MOISTURE ON THE BACKSIDE OF THIS SYSTEM
MONDAY NIGHT INTO TUESDAY BUT ITS POSSIBLE FOR SOME SNOW
ACCUMULATION...ESPECIALLY AS SNOW SHOWERS WILL STILL BE POSSIBLE
ON TUESDAY.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 03Z...
* MVFR CIGS OVERNIGHT INTO FRIDAY.
* LAKE EFFECT SNOW SHOWERS FRIDAY.
* GUSTY NORTHEAST WINDS FRIDAY/FRIDAY EVENING. CMS
//DISCUSSION...UPDATED 00Z...
MVFR CIGS ARE JUST NORTH OF THE TERMINALS ACROSS SOUTHERN WI AND
OVER LAKE MICHIGAN. AS WINDS SLOWLY TURN MORE NORTHERLY THIS
EVENING...EXPECT THESE MVFR CIGS TO SPREAD SOUTH ACROSS THE
TERMINALS WITH PREVAILING MVFR CIGS BY DAYBREAK FRIDAY. BUT HOW
SOON THEY ARRIVE OR POSSIBLY DEVELOP IS STILL A BIT UNCERTAIN.
AS NORTHEASTERLY WINDS INCREASE OVERNIGHT INTO FRIDAY MORNING...
LAKE EFFECT SNOW SHOWERS ARE EXPECTED TO DEVELOP AND SPREAD INTO
NORTHEAST IL DURING THE MID/LATE MORNING HOURS...POSSIBLY
AFFECTING GYY AROUND DAYBREAK BEFORE SHIFTING FURTHER WEST. ANY
SNOW SHOWERS THAT DEVELOP WILL HAVE THE POTENTIAL TO PRODUCE IFR
VIS BUT CONFIDENCE REGARDING WHERE THESE WILL OCCUR AS WELL AS
THEIR DURATION STILL REMAINS LOW AND THEREFORE MAINTAINED
PREVAILING FLURRIES WITH PROB FOR LOWER CONDITIONS. AS SNOW
SHOWERS EMERGE LATER TONIGHT...BETTER TIMING/DURATION AND PERHAPS
SHORTER TEMPO GROUPS CAN BE EXPECTED WITH LATER FORECASTS.
LIGHT WINDS WILL SLOWLY TURN LIGHT NORTHERLY THIS EVENING AND
GRADUALLY INCREASE IN SPEEDS FRIDAY MORNING WITH GUSTS INTO THE
TEENS DEVELOPING. SPEEDS/GUSTS WILL CONTINUE TO INCREASE FRIDAY
AFTERNOON WITH GUSTS TO 20KTS POSSIBLE AS THE GRADIENT TIGHTENS.
CMS
//ORD AND MDW CONFIDENCE...UPDATED 03Z...
* HIGH FOR MVFR CIGS OVERNIGHT INTO FRIDAY...LOW FOR ARRIVAL TIME.
* MEDIUM FOR SNOW SHOWERS AND TIMING...LOW FOR ASSOCIATED VIS/CIGS
AND DURATION.
* MEDIUM FOR WINDS THRU THE PERIOD. CMS
//OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z...
* SATURDAY...DRY/VFR. LIGHT WINDS.
* SUNDAY...DRY. MVFR POSSIBLE. SOUTHWEST WINDS.
* MONDAY...CHANCE OF RAIN/SNOW. MVFR LIKELY. IFR POSSIBLE.
SOUTHERLY WINDS.
* TUESDAY...CHANCE OF SNOW/MVFR. IFR POSSIBLE. GUSTY WESTERLY
WINDS.
* WEDNESDAY...DRY. MVFR POSSIBLE. SOUTHWESTERLY WINDS.
&&
.MARINE...
258 PM CST
GENERALLY LIGHTER WINDS OVER THE LAKE CONTINUING THIS AFTERNOON
AS HIGH PRESSURE SPANS MUCH OF THE GREAT LAKES REGION TODAY.
HOWEVER...THIS HIGH WILL SHIFT EAST THROUGH FRIDAY MORNING WHILE
DEVELOPING LOW PRESSURE SHIFTS EAST ACROSS THE GULF COAST STATES
TONIGHT INTO FRIDAY. THIS WILL ALLOW THE WINDS TO BECOME MORE
ORGANIZED OUT OF THE NORTH TONIGHT...AND THEN INCREASE TO THE 15
TO 25 KT RANGE OUT OF THE NORTH/NORTHEAST FRIDAY ACROSS THE ENTIRE
LAKE. WAVES WILL BUILD DURING THIS TIME WITH WAVES ACROSS THE
NEARSHORE APPROACHING SMALL CRAFT ADVISORY CONDITIONS...FOR ICE
FREE AREAS. AS THIS LOW PUSHES FURTHER AWAY FROM THE REGION THE
GRADIENT OVER THE LAKE DOES RELAX WITH WINDS DIMINISHING FRIDAY
NIGHT INTO SATURDAY MORNING. HOWEVER...LOW PRESSURE WILL MOVE FROM
ONTARIO TO QUEBEC SATURDAY INTO SATURDAY NIGHT AND AS THIS
OCCURS...EXPECT WINDS TO BECOME MORE SOUTHERLY AND INCREASING TO
THE 30KT RANGE SATURDAY NIGHT.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
133 PM CST WED JAN 20 2016
.UPDATE...
1051 AM CST
FOR MORNING UPDATE...
SECONDARY VORT/MID-LEVEL SHORT WAVE TROUGH MOVE ACROSS FAR
NORTHEAST IL/SOUTHERN LAKE MICHIGAN THROUGH LATE MORNING WILL MOVE
OFF TO THE EAST THIS AFTERNOON...BRINING ANY LINGERING FLURRIES TO
AN END IN THE NEXT HOUR OR TWO. RISING HEIGHTS AND SUBSIDENCE
BEHIND DEPARTING SHORT WAVE WILL HELP THIN CLOUD COVER SOMEWHAT
ESPECIALLY OVER WEST/SOUTH PARTS OF THE CWA AS IS CURRENTLY SEEN
DEVELOPING IN VIS SATELLITE IMAGERY...THOUGH LOW STRATOCU NOTED
DEVELOPING UPSTREAM WHICH WILL LIKELY MAINTAIN PARTLY SUNNY
CONDITIONS AT BEST AND PERHAPS MORE MOSTLY CLOUDY ACROSS FAR
NORTHEAST IL WHERE MORE EXTENSIVE CLOUD COVER EXISTS UPSTREAM INTO
SOUTHERN WI. OTHERWISE...TEMPS ON TRACK FOR AFTERNOON HIGHS 19-22
WHICH WITH LIGHT/VARIABLE WINDS UNDER DEVELOPING SURFACE HIGH
PRESSURE SHOULD MAKE IT FEEL A WHOLE LOT BETTER THAN THE
WINDY/COLD OF THE PAST FEW DAYS.
RATZER
&&
.SHORT TERM...
313 AM CST
THROUGH THURSDAY...
PRIMARY CONCERN IN THE SHORT TERM IS ESCORTING THE SNOW OUT OF THE
CWA IN THE GRIDS EARLY THIS MORNING. BACK EDGE OF THE LIGHTLY
ACCUMULATING SNOW IS MAKING STEADY PROGRESS EAST AND SHOULD SEE AN
END TO THREAT OF ACCUMULATIONS BY 10-11Z IN CHICAGO AREA AND BY
12Z OVER NW INDIANA. WHILE MOST OF THE SNOW SHOULD END JUST PRIOR
TO RUSH HOUR...RADAR AND SURFACE OBS UPSTREAM DO INDICATE A SOME
SCATTERED LINGERING FLURRIES NORTHWEST BACK TO THE TROUGH AXIS
OVER SOUTHERN WISCONSIN/NE IA AND SE MN. HAVE ADDED SOME FLURRIES
INTO THROUGH 15Z...THOUGH RAP RH PROGS SUGGEST THAT FLURRIES COULD
POTENTIALLY EVEN LINGER A BIT LONGER BUT WILL LET DAY SHIFT EXTEND
THE MENTION IF NEEDED. ONCE FLURRIES END SHOULD REMAIN CLOUDY
THROUGH THE REMAINDER OF THE SHORT TERM PERIOD WITH ONLY SMALL
DIURNAL SWINGS IN TEMPS. GIVEN THE EXPECTED CLOUD COVER AND WEAK
THERMAL ADVECTION HAVE LEANED TOWARD THE COOLER SIDE OF GUIDANCE
FOR HIGH TEMPS AND TOWARD THE WARMER SIDE OF GUIDANCE FOR LOW
TEMPS.
IZZI
&&
.LONG TERM...
133 PM CST
THURSDAY NIGHT THROUGH WEDNESDAY...
MAIN CONCERN FOR THE LONGER TERM FORECAST PERIOD REMAINS THE CHANCES
FOR LAKE EFFECT SNOW FRIDAY THROUGH FRIDAY NIGHT.
IN THE MEAN TIME...THURSDAY NIGHT SHOULD START OUT THE LONG TERM
FORECAST PERIOD RELATIVELY QUIET AS THE REGION WILL BE BETWEEN A
LARGE AREA OF HIGH PRESSURE EXTENDING FROM THE NORTHERN PLAINS
THROUGH THE GREAT LAKES AND A DEEPENING LOW PRESSURE SYSTEM MOVES
THROUGH THE LOWER MISSISSIPPI VALLEY. WINDS WILL BEGIN TO SET UP
NELY...LEADING INTO THE PERIOD OF LAKE EFFECT SNOW EXPECTED FOR
FRIDAY. BY MIDDAY FRIDAY...THE HIGH WILL EXTEND FROM THE UPPER
GREAT LAKES THROUGH THE SOUTH HIGH PLAINS WHILE LOW PRESSURE DEEPENS
OVER THE SERN CONUS. A RELATIVE WEAKNESS IN THE PRESSURE GRADIENT IS
EXPECTED TO DEVELOP ACROSS LOWER MICHIGAN...LAKE MICHIGAN AND INTO
NRN ILLINOIS. WHILE THE GENERAL PATTERN WILL BE CONDUCIVE FOR LAKE
EFFECT SNOW FOR NERN IL...POSSIBLY EXTENDING INTO FAR NWRN INDIANA
ARND GYY...THE GREATEST LAKE INDUCED INSTABILITY SHOULD BE DURG THE
DAYTIME HOURS ON FRIDAY WHEN INVERSION HEIGHTS WILL BE ARND 5KFT AND
SFC TO 850MB DELTA-T SHOULD BE ARND 13C UNDER NELY WINDS. WHILE THE
LONGER TERM GUIDANCE MAY LACK THE RESOLUTION OF THE SHORT TERM
GUIDANCE...THE GFS/ECMWF ALSO INDICATE A CONVERGENCE BAND OVER THE
SWRN PORTION OF LAKE MICHIGAN...FURTHER AIDING CONFIDENCE IN AT
LEAST SOME LAKE EFFECT SNOW ACCUMULATION. WEAK CONVERGENCE IS
EXPECTED TO CONTINUE INTO FRIDAY NIGHT...BUT THE FOCUS SHOULD SHIFT
A LITTLE NORTH INTO SERN WISCONSIN. ALSO...LOW LEVEL INVERSION
HEIGHTS AND INSTABILITY SHOULD DIMINISH THROUGH THE NIGHT...PER
LATEST MODEL SOUNDINGS...SO EXPECT THE LAKE EFFECT SNOW POTENTIAL TO
END BY SATURDAY MORNING. GIVEN WEAK FORCING AND MARGINAL LOW LEVEL
INSTABILITY ALONG WITH A PROGRESSIVE CONVERGENCE ZONE...SNOW
ACCUMULATIONS SHOULD BE LIGHT...GENERALLY UNDER AN INCH.
FOR THE REMAINDER OF THE WEEKEND...THE AREA OF HIGH PRESSURE SHOULD
MOVE ACROSS THE REGION...SETTLING INTO THE OHIO VALLEY SUNDAY NIGHT.
EXPECT AMPLE SUNSHINE AND HIGHS IN THE LOWER 30S FOR SATURDAY AND
THE MIDDLE 30S SUNDAY. RELATIVELY MILD CONDITIONS SHOULD CONTINUE
INTO MONDAY AS BROAD...DIFFUSE LOW PRESSURE ASSOCIATED WITH A
SOUTHERN STREAM SHORTWAVE...REACHES THE MIDDLE MISSISSIPPI
VALLEY...WITH A ZONE OF BROAD WARM/MOIST ADVECTION AHEAD OF THE WEAK
LOW. THIS SYSTEM SHOULD BRING THE NEXT CHANCE OF PCPN...STARTING
OUT AS A MIX OF RAIN AND SNOW SHOWERS MONDAY WITH SOME LINGERING
LIGHT SNOW SHOWERS POSSIBLE INTO MONDAY NIGHT OR TUESDAY. CURRENT
INDICATORS SUGGEST WEAK SFC FORCING AND MODERATE ISENTROPIC LIFT
AHEAD OF AN ASSOCIATED COLD FRONT...SO...PCPN AMOUNTS SHOULD BE
RELATIVELY LIGHT.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* MVFR CEILINGS TODAY...POSSIBLY PERSISTING INTO TONIGHT.
RODRIGUEZ
//DISCUSSION...UPDATED 18Z...
WHILE VFR CEILINGS CONTINUE TO MOVE ACROSS THE
TERMINALS...DIURNALLY DRIVEN MVFR CEILINGS HAVE DEVELOPED TODAY.
HAVE HIGHER CONFIDENCE WITH THESE LOWER CEILINGS TO REMAIN
OVERHEAD THIS AFTERNOON OR AT LEAST CONTINUE TO PERIODICALLY MOVE
ACROSS THE TERMINALS BUT CONFIDENCE LOWERS INTO THIS EVENING WITH
SOME POTENTIAL FOR THEM TO REMAIN. AT THIS TIME...LIKELY SCENARIO
WILL BE FOR THEM TO SCATTER EARLY THIS EVENING. HOWEVER...ONCE
AGAIN WEATHER PATTERN TONIGHT COULD ALLOW FOR REDEVELOPMENT
OVERNIGHT. ALSO...HAVE LEFT OUT ANY FOG MENTION TONIGHT BUT THERE
WILL BE POTENTIAL FOR AT LEAST SOME ISOLATED MVFR VIS/FOG TO
DEVELOP. HIGH PRESSURE OVERHEAD THROUGH THE PERIOD WILL ALLOW FOR
MAINLY LIGHT AND VARIABLE WINDS BUT WHEN THE WINDS DO HOLD ONTO A
DIRECTION...WILL LIKELY BE SOME LIGHT WESTERLY COMPONENT.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH WITH WIND SPEED/DIRECTION.
* MEDIUM HIGH WITH CEILINGS THIS AFTERNOON...LOW MEDIUM THIS
EVENING/TONIGHT.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT...MAINLY VFR. LIGHT NORTH- NORTHEASTERLY WINDS.
FRIDAY...SLIGHT CHANCE OF LIGHT SNOW SHOWERS AND MVFR/IFR. BREEZY
NORTHEAST WINDS.
SATURDAY...VFR. NORTH-NORTHEAST WINDS TURNING SOUTHWEST.
SUNDAY...VFR. SOUTHWEST WINDS.
MONDAY...CHANCE OF RAIN OR SNOW AND MVFR/IFR.
TUESDAY...CHANCE OF SNOW. MVFR/IFR POSSIBLE.
KJB
&&
.MARINE...
106 PM CST
RELATIVELY QUIET WEATHER EXPECTED ACROSS LAKE MICHIGAN OVER THE
NEXT SEVERAL DAYS...WITH THE ONLY PERIOD OF NOTE BEING FRIDAY AND
FRIDAY NIGHT AS WINDS TURN NORTH-NORTHEAST AND INCREASE INTO THE
20-25 KT RANGE PARTICULARLY ON THE SOUTHERN HALF OR SO OF THE
LAKE. THIS WILL BE IN RESPONSE TO AN AREA OF LOW PRESSURE WHICH
WILL DEVELOP ACROSS THE SOUTHERN PLAINS AND LOWER MISSISSIPPI
VALLEY...WHICH IS FORECAST TO DEEPEN AND MOVE NORTHEAST ACROSS THE
GULF STATES/LOWER TENNESSEE VALLEY FRIDAY BEFORE REDEVELOPING
ALONG THE MID-ATLANTIC COAST ON SATURRDAY AND MOVING NORTHEAST OFF
THE NEW ENGLAND COAST ON SUNDAY. WINDS ON LAKE MICHIGAN LOOK TO
INCREASE FRIDAY AFTERNOON...THEN WEAKEN LATE FRIDAY NIGHT/EARLY
SATURDAY AS A RIDGE OF HIGH PRESSURE MOVES OVER THE
WESTERN/NORTHERN LAKES. OTHERWISE...LONGER RANGE MODEL GUIDANCE
INDICATES ANOTHER WEAKER LOW PRESSURE SYSTEM MAY DEVELOP OVER THE
SOUTH-CENTRAL PLAINS SUNDAY NIGHT...MOVING TO THE GREAT LAKES
REGION BY LATE MONDAY.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
107 PM CST WED JAN 20 2016
.UPDATE...
1051 AM CST
FOR MORNING UPDATE...
SECONDARY VORT/MID-LEVEL SHORT WAVE TROUGH MOVE ACROSS FAR
NORTHEAST IL/SOUTHERN LAKE MICHIGAN THROUGH LATE MORNING WILL MOVE
OFF TO THE EAST THIS AFTERNOON...BRINING ANY LINGERING FLURRIES TO
AN END IN THE NEXT HOUR OR TWO. RISING HEIGHTS AND SUBSIDENCE
BEHIND DEPARTING SHORT WAVE WILL HELP THIN CLOUD COVER SOMEWHAT
ESPECIALLY OVER WEST/SOUTH PARTS OF THE CWA AS IS CURRENTLY SEEN
DEVELOPING IN VIS SATELLITE IMAGERY...THOUGH LOW STRATOCU NOTED
DEVELOPING UPSTREAM WHICH WILL LIKELY MAINTAIN PARTLY SUNNY
CONDITIONS AT BEST AND PERHAPS MORE MOSTLY CLOUDY ACROSS FAR
NORTHEAST IL WHERE MORE EXTENSIVE CLOUD COVER EXISTS UPSTREAM INTO
SOUTHERN WI. OTHERWISE...TEMPS ON TRACK FOR AFTERNOON HIGHS 19-22
WHICH WITH LIGHT/VARIABLE WINDS UNDER DEVELOPING SURFACE HIGH
PRESSURE SHOULD MAKE IT FEEL A WHOLE LOT BETTER THAN THE
WINDY/COLD OF THE PAST FEW DAYS.
RATZER
&&
.SHORT TERM...
313 AM CST
THROUGH THURSDAY...
PRIMARY CONCERN IN THE SHORT TERM IS ESCORTING THE SNOW OUT OF THE
CWA IN THE GRIDS EARLY THIS MORNING. BACK EDGE OF THE LIGHTLY
ACCUMULATING SNOW IS MAKING STEADY PROGRESS EAST AND SHOULD SEE AN
END TO THREAT OF ACCUMULATIONS BY 10-11Z IN CHICAGO AREA AND BY
12Z OVER NW INDIANA. WHILE MOST OF THE SNOW SHOULD END JUST PRIOR
TO RUSH HOUR...RADAR AND SURFACE OBS UPSTREAM DO INDICATE A SOME
SCATTERED LINGERING FLURRIES NORTHWEST BACK TO THE TROUGH AXIS
OVER SOUTHERN WISCONSIN/NE IA AND SE MN. HAVE ADDED SOME FLURRIES
INTO THROUGH 15Z...THOUGH RAP RH PROGS SUGGEST THAT FLURRIES COULD
POTENTIALLY EVEN LINGER A BIT LONGER BUT WILL LET DAY SHIFT EXTEND
THE MENTION IF NEEDED. ONCE FLURRIES END SHOULD REMAIN CLOUDY
THROUGH THE REMAINDER OF THE SHORT TERM PERIOD WITH ONLY SMALL
DIURNAL SWINGS IN TEMPS. GIVEN THE EXPECTED CLOUD COVER AND WEAK
THERMAL ADVECTION HAVE LEANED TOWARD THE COOLER SIDE OF GUIDANCE
FOR HIGH TEMPS AND TOWARD THE WARMER SIDE OF GUIDANCE FOR LOW
TEMPS.
IZZI
&&
.LONG TERM...
313 AM CST
THURSDAY NIGHT THROUGH TUESDAY...
ABOUT THE ONLY THING TO TALK ABOUT IN THE LONG TERM IS THE LAKE
EFFECT POTENTIAL ON FRIDAY INTO FRIDAY EVENING.
OVERALL...CONTINUES TO LOOK LIKE A MARGINAL SET-UP AT BEST.
POWERFUL AND DEEPENING SOUTHERN STREAM CYCLONE TRACKING ACROSS THE
SOUTHEASTERN CONUS WILL RESULT IN AN INCREASING NORTH-NORTHEAST
FLOW DOWN THE FULL FETCH OF THE LAKE. DESPITE THE FAVORABLE WIND
DIRECTION AND THE FACT THAT MOST OF THE MODELS DO ATTEMPT TO SPIT
OUT SOME QPF...MOST OTHER FACTORS LOOK EITHER MARGINAL OR
UNFAVORABLE FOR LAKE EFFECT. STRONG SOUTHERN STORM SYSTEM IS NOT
PHASED WITH THE POLAR JET...SO WHILE IT IS TRACKING EAST MID-UPPER
LEVEL HEIGHTS ARE ALREADY RISING FRIDAY IN OUR NECK OF THE WOODS
AS NORTHERN STREAM SHORTWAVE RIDGING BUILDS EAST. THE RISING
HEIGHTS WILL ACT TO RE-ENFORCE SUBSIDENCE/FRONTAL INVERSION WHICH
IS PROGGED TO PEAK AROUND 5KFT AGL. AMBIENT TEMPS AT THE LAKE
INDUCED EQUILIBRIUM LEVEL ARE ONLY FORECAST TO BE IN THE -10 TO
-12C RANGE...SO ITS QUESTIONABLE IF ICE NUCLEI WILL EVEN BE
PRESENT FOR SNOW AND MORE LIKELY THAN NOT ANYTHING THAT FALLS
COULD BE LIGHT SNOW GRAIN SHOWERS. WHAT INSTABILITY THAT DOES
EXIST BELOW THE SHALLOW INVERSION IS ALSO WEAK AND NOT FAVORABLE
FOR LAKE EFFECT. GIVEN THE PERPONDERANCE OF THE EVIDENCE AGAINST
MEANINGFUL LAKE EFFECT SNOW HAVE MAINTAINED JUST LOW CHANCE POPS
FOR SOME LIGHT SNOW SHOWERS OR FLURRIES.
AFTER EXTENDED PERIOD OF CLOUD COVER LOOK FOR CLOUDINESS TO
GRADUALLY BREAK UP FOR A TIME OVER THE WEEKEND BRIEFLY. THE SLOW
MODERATION IN TEMPS WILL ALSO CONTINUE THROUGH THE WEEKEND...TO
THE POINT WE SHOULD BE A BIT ABOVE SEASONAL NORMS BY THE
WEEKEND...PARTICULARLY NIGHTTIME LOWS. WHILE DETAILS VARY IN HOW
IT EVOLVES...BOTH GFS AND ECMWF SUGGEST A SYSTEM WILL AFFECT THE
REGION EARLY NEXT WEEK. A BIT TOO FAR OUT AT THIS POINT TO PIN
DOWN P-TYPE AS IT DOES LOOK LIKE WE COULD END UP ON EITHER SIDE OF
THE RAIN/SNOW LINE DEPENDING ON EVENTUAL TRACK/INTENSITY OF THE
SYSTEM.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* MVFR CEILINGS TODAY...POSSIBLY PERSISTING INTO TONIGHT.
RODRIGUEZ
//DISCUSSION...UPDATED 18Z...
WHILE VFR CEILINGS CONTINUE TO MOVE ACROSS THE
TERMINALS...DIURNALLY DRIVEN MVFR CEILINGS HAVE DEVELOPED TODAY.
HAVE HIGHER CONFIDENCE WITH THESE LOWER CEILINGS TO REMAIN
OVERHEAD THIS AFTERNOON OR AT LEAST CONTINUE TO PERIODICALLY MOVE
ACROSS THE TERMINALS BUT CONFIDENCE LOWERS INTO THIS EVENING WITH
SOME POTENTIAL FOR THEM TO REMAIN. AT THIS TIME...LIKELY SCENARIO
WILL BE FOR THEM TO SCATTER EARLY THIS EVENING. HOWEVER...ONCE
AGAIN WEATHER PATTERN TONIGHT COULD ALLOW FOR REDEVELOPMENT
OVERNIGHT. ALSO...HAVE LEFT OUT ANY FOG MENTION TONIGHT BUT THERE
WILL BE POTENTIAL FOR AT LEAST SOME ISOLATED MVFR VIS/FOG TO
DEVELOP. HIGH PRESSURE OVERHEAD THROUGH THE PERIOD WILL ALLOW FOR
MAINLY LIGHT AND VARIABLE WINDS BUT WHEN THE WINDS DO HOLD ONTO A
DIRECTION...WILL LIKELY BE SOME LIGHT WESTERLY COMPONENT.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH WITH WIND SPEED/DIRECTION.
* MEDIUM HIGH WITH CEILINGS THIS AFTERNOON...LOW MEDIUM THIS
EVENING/TONIGHT.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT...MAINLY VFR. LIGHT NORTH- NORTHEASTERLY WINDS.
FRIDAY...SLIGHT CHANCE OF LIGHT SNOW SHOWERS AND MVFR/IFR. BREEZY
NORTHEAST WINDS.
SATURDAY...VFR. NORTH-NORTHEAST WINDS TURNING SOUTHWEST.
SUNDAY...VFR. SOUTHWEST WINDS.
MONDAY...CHANCE OF RAIN OR SNOW AND MVFR/IFR.
TUESDAY...CHANCE OF SNOW. MVFR/IFR POSSIBLE.
KJB
&&
.MARINE...
106 PM CST
RELATIVELY QUIET WEATHER EXPECTED ACROSS LAKE MICHIGAN OVER THE
NEXT SEVERAL DAYS...WITH THE ONLY PERIOD OF NOTE BEING FRIDAY AND
FRIDAY NIGHT AS WINDS TURN NORTH-NORTHEAST AND INCREASE INTO THE
20-25 KT RANGE PARTICULARLY ON THE SOUTHERN HALF OR SO OF THE
LAKE. THIS WILL BE IN RESPONSE TO AN AREA OF LOW PRESSURE WHICH
WILL DEVELOP ACROSS THE SOUTHERN PLAINS AND LOWER MISSISSIPPI
VALLEY...WHICH IS FORECAST TO DEEPEN AND MOVE NORTHEAST ACROSS THE
GULF STATES/LOWER TENNESSEE VALLEY FRIDAY BEFORE REDEVELOPING
ALONG THE MID-ATLANTIC COAST ON SATURRDAY AND MOVING NORTHEAST OFF
THE NEW ENGLAND COAST ON SUNDAY. WINDS ON LAKE MICHIGAN LOOK TO
INCREASE FRIDAY AFTERNOON...THEN WEAKEN LATE FRIDAY NIGHT/EARLY
SATURDAY AS A RIDGE OF HIGH PRESSURE MOVES OVER THE
WESTERN/NORTHERN LAKES. OTHERWISE...LONGER RANGE MODEL GUIDANCE
INDICATES ANOTHER WEAKER LOW PRESSURE SYSTEM MAY DEVELOP OVER THE
SOUTH-CENTRAL PLAINS SUNDAY NIGHT...MOVING TO THE GREAT LAKES
REGION BY LATE MONDAY.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1154 AM CST WED JAN 20 2016
.UPDATE...
1051 AM CST
FOR MORNING UPDATE...
SECONDARY VORT/MID-LEVEL SHORT WAVE TROUGH MOVE ACROSS FAR
NORTHEAST IL/SOUTHERN LAKE MICHIGAN THROUGH LATE MORNING WILL MOVE
OFF TO THE EAST THIS AFTERNOON...BRINING ANY LINGERING FLURRIES TO
AN END IN THE NEXT HOUR OR TWO. RISING HEIGHTS AND SUBSIDENCE
BEHIND DEPARTING SHORT WAVE WILL HELP THIN CLOUD COVER SOMEWHAT
ESPECIALLY OVER WEST/SOUTH PARTS OF THE CWA AS IS CURRENTLY SEEN
DEVELOPING IN VIS SATELLITE IMAGERY...THOUGH LOW STRATOCU NOTED
DEVELOPING UPSTREAM WHICH WILL LIKELY MAINTAIN PARTLY SUNNY
CONDITIONS AT BEST AND PERHAPS MORE MOSTLY CLOUDY ACROSS FAR
NORTHEAST IL WHERE MORE EXTENSIVE CLOUD COVER EXISTS UPSTREAM INTO
SOUTHERN WI. OTHERWISE...TEMPS ON TRACK FOR AFTERNOON HIGHS 19-22
WHICH WITH LIGHT/VARIABLE WINDS UNDER DEVELOPING SURFACE HIGH
PRESSURE SHOULD MAKE IT FEEL A WHOLE LOT BETTER THAN THE
WINDY/COLD OF THE PAST FEW DAYS.
RATZER
&&
.SHORT TERM...
313 AM CST
THROUGH THURSDAY...
PRIMARY CONCERN IN THE SHORT TERM IS ESCORTING THE SNOW OUT OF THE
CWA IN THE GRIDS EARLY THIS MORNING. BACK EDGE OF THE LIGHTLY
ACCUMULATING SNOW IS MAKING STEADY PROGRESS EAST AND SHOULD SEE AN
END TO THREAT OF ACCUMULATIONS BY 10-11Z IN CHICAGO AREA AND BY
12Z OVER NW INDIANA. WHILE MOST OF THE SNOW SHOULD END JUST PRIOR
TO RUSH HOUR...RADAR AND SURFACE OBS UPSTREAM DO INDICATE A SOME
SCATTERED LINGERING FLURRIES NORTHWEST BACK TO THE TROUGH AXIS
OVER SOUTHERN WISCONSIN/NE IA AND SE MN. HAVE ADDED SOME FLURRIES
INTO THROUGH 15Z...THOUGH RAP RH PROGS SUGGEST THAT FLURRIES COULD
POTENTIALLY EVEN LINGER A BIT LONGER BUT WILL LET DAY SHIFT EXTEND
THE MENTION IF NEEDED. ONCE FLURRIES END SHOULD REMAIN CLOUDY
THROUGH THE REMAINDER OF THE SHORT TERM PERIOD WITH ONLY SMALL
DIURNAL SWINGS IN TEMPS. GIVEN THE EXPECTED CLOUD COVER AND WEAK
THERMAL ADVECTION HAVE LEANED TOWARD THE COOLER SIDE OF GUIDANCE
FOR HIGH TEMPS AND TOWARD THE WARMER SIDE OF GUIDANCE FOR LOW
TEMPS.
IZZI
&&
.LONG TERM...
313 AM CST
THURSDAY NIGHT THROUGH TUESDAY...
ABOUT THE ONLY THING TO TALK ABOUT IN THE LONG TERM IS THE LAKE
EFFECT POTENTIAL ON FRIDAY INTO FRIDAY EVENING.
OVERALL...CONTINUES TO LOOK LIKE A MARGINAL SET-UP AT BEST.
POWERFUL AND DEEPENING SOUTHERN STREAM CYCLONE TRACKING ACROSS THE
SOUTHEASTERN CONUS WILL RESULT IN AN INCREASING NORTH-NORTHEAST
FLOW DOWN THE FULL FETCH OF THE LAKE. DESPITE THE FAVORABLE WIND
DIRECTION AND THE FACT THAT MOST OF THE MODELS DO ATTEMPT TO SPIT
OUT SOME QPF...MOST OTHER FACTORS LOOK EITHER MARGINAL OR
UNFAVORABLE FOR LAKE EFFECT. STRONG SOUTHERN STORM SYSTEM IS NOT
PHASED WITH THE POLAR JET...SO WHILE IT IS TRACKING EAST MID-UPPER
LEVEL HEIGHTS ARE ALREADY RISING FRIDAY IN OUR NECK OF THE WOODS
AS NORTHERN STREAM SHORTWAVE RIDGING BUILDS EAST. THE RISING
HEIGHTS WILL ACT TO RE-ENFORCE SUBSIDENCE/FRONTAL INVERSION WHICH
IS PROGGED TO PEAK AROUND 5KFT AGL. AMBIENT TEMPS AT THE LAKE
INDUCED EQUILIBRIUM LEVEL ARE ONLY FORECAST TO BE IN THE -10 TO
-12C RANGE...SO ITS QUESTIONABLE IF ICE NUCLEI WILL EVEN BE
PRESENT FOR SNOW AND MORE LIKELY THAN NOT ANYTHING THAT FALLS
COULD BE LIGHT SNOW GRAIN SHOWERS. WHAT INSTABILITY THAT DOES
EXIST BELOW THE SHALLOW INVERSION IS ALSO WEAK AND NOT FAVORABLE
FOR LAKE EFFECT. GIVEN THE PERPONDERANCE OF THE EVIDENCE AGAINST
MEANINGFUL LAKE EFFECT SNOW HAVE MAINTAINED JUST LOW CHANCE POPS
FOR SOME LIGHT SNOW SHOWERS OR FLURRIES.
AFTER EXTENDED PERIOD OF CLOUD COVER LOOK FOR CLOUDINESS TO
GRADUALLY BREAK UP FOR A TIME OVER THE WEEKEND BRIEFLY. THE SLOW
MODERATION IN TEMPS WILL ALSO CONTINUE THROUGH THE WEEKEND...TO
THE POINT WE SHOULD BE A BIT ABOVE SEASONAL NORMS BY THE
WEEKEND...PARTICULARLY NIGHTTIME LOWS. WHILE DETAILS VARY IN HOW
IT EVOLVES...BOTH GFS AND ECMWF SUGGEST A SYSTEM WILL AFFECT THE
REGION EARLY NEXT WEEK. A BIT TOO FAR OUT AT THIS POINT TO PIN
DOWN P-TYPE AS IT DOES LOOK LIKE WE COULD END UP ON EITHER SIDE OF
THE RAIN/SNOW LINE DEPENDING ON EVENTUAL TRACK/INTENSITY OF THE
SYSTEM.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* MVFR CEILINGS TODAY...POSSIBLY PERSISTING INTO TONIGHT.
RODRIGUEZ
//DISCUSSION...UPDATED 18Z...
WHILE VFR CEILINGS CONTINUE TO MOVE ACROSS THE
TERMINALS...DIURNALLY DRIVEN MVFR CEILINGS HAVE DEVELOPED TODAY.
HAVE HIGHER CONFIDENCE WITH THESE LOWER CEILINGS TO REMAIN
OVERHEAD THIS AFTERNOON OR AT LEAST CONTINUE TO PERIODICALLY MOVE
ACROSS THE TERMINALS BUT CONFIDENCE LOWERS INTO THIS EVENING WITH
SOME POTENTIAL FOR THEM TO REMAIN. AT THIS TIME...LIKELY SCENARIO
WILL BE FOR THEM TO SCATTER EARLY THIS EVENING. HOWEVER...ONCE
AGAIN WEATHER PATTERN TONIGHT COULD ALLOW FOR REDEVELOPMENT
OVERNIGHT. ALSO...HAVE LEFT OUT ANY FOG MENTION TONIGHT BUT THERE
WILL BE POTENTIAL FOR AT LEAST SOME ISOLATED MVFR VIS/FOG TO
DEVELOP. HIGH PRESSURE OVERHEAD THROUGH THE PERIOD WILL ALLOW FOR
MAINLY LIGHT AND VARIABLE WINDS BUT WHEN THE WINDS DO HOLD ONTO A
DIRECTION...WILL LIKELY BE SOME LIGHT WESTERLY COMPONENT.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH WITH WIND SPEED/DIRECTION.
* MEDIUM HIGH WITH CEILINGS THIS AFTERNOON...LOW MEDIUM THIS
EVENING/TONIGHT.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT...MAINLY VFR. LIGHT NORTH- NORTHEASTERLY WINDS.
FRIDAY...SLIGHT CHANCE OF LIGHT SNOW SHOWERS AND MVFR/IFR. BREEZY
NORTHEAST WINDS.
SATURDAY...VFR. NORTH-NORTHEAST WINDS TURNING SOUTHWEST.
SUNDAY...VFR. SOUTHWEST WINDS.
MONDAY...CHANCE OF RAIN OR SNOW AND MVFR/IFR.
TUESDAY...CHANCE OF SNOW. MVFR/IFR POSSIBLE.
KJB
&&
.MARINE...
100 AM CST
SURFACE HIGH PRESSURE WILL CONTINUE TO RESULT IN GENERALLY LIGHT
WESTERLY FLOW OVER THE LAKE THROUGH THURSDAY. HOWEVER...BY
FRIDAY...AN AREA OF LOW PRESSURE IS EXPECTED TO TRACK FROM THE
SOUTHERN MISSISSIPPI VALLEY EASTWARD OVER THE SOUTHEASTERN CONUS
AS A SURFACE RIDGE OF HIGH PRESSURE BUILDS SOUTHWARD OVER THE
UPPER GREAT LAKES. THIS LOOKS TO RESULT IN A PERIOD OF STRONGER
NORTHERLY WINDS...ESPECIALLY OVER THE SOUTHERN END OF THE
LAKE. THIS COULD RESULT IN THE NEED FOR ANOTHER SMALL CRAFT
ADVISORY FOR THE ILLINOIS AND INDIANA NEAR SHORES.
HOWEVER...THERE ARE UNCERTAINTIES ON WAVE HEIGHTS ALONG THE NEAR
SHORES DUE TO THE RECENT BUILD UP OF ICE. ICE TRENDS WILL NEED TO
BE MONITORED OVER THE NEXT COUPLE DAYS.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1051 AM CST WED JAN 20 2016
.UPDATE...
1051 AM CST
FOR MORNING UPDATE...
SECONDARY VORT/MID-LEVEL SHORT WAVE TROUGH MOVE ACROSS FAR
NORTHEAST IL/SOUTHERN LAKE MICHIGAN THROUGH LATE MORNING WILL MOVE
OFF TO THE EAST THIS AFTERNOON...BRINING ANY LINGERING FLURRIES TO
AN END IN THE NEXT HOUR OR TWO. RISING HEIGHTS AND SUBSIDENCE
BEHIND DEPARTING SHORT WAVE WILL HELP THIN CLOUD COVER SOMEWHAT
ESPECIALLY OVER WEST/SOUTH PARTS OF THE CWA AS IS CURRENTLY SEEN
DEVELOPING IN VIS SATELLITE IMAGERY...THOUGH LOW STRATOCU NOTED
DEVELOPING UPSTREAM WHICH WILL LIKELY MAINTAIN PARTLY SUNNY
CONDITIONS AT BEST AND PERHAPS MORE MOSTLY CLOUDY ACROSS FAR
NORTHEAST IL WHERE MORE EXTENSIVE CLOUD COVER EXISTS UPSTREAM INTO
SOUTHERN WI. OTHERWISE...TEMPS ON TRACK FOR AFTERNOON HIGHS 19-22
WHICH WITH LIGHT/VARIABLE WINDS UNDER DEVELOPING SURFACE HIGH
PRESSURE SHOULD MAKE IT FEEL A WHOLE LOT BETTER THAN THE
WINDY/COLD OF THE PAST FEW DAYS.
RATZER
&&
.SHORT TERM...
313 AM CST
THROUGH THURSDAY...
PRIMARY CONCERN IN THE SHORT TERM IS ESCORTING THE SNOW OUT OF THE
CWA IN THE GRIDS EARLY THIS MORNING. BACK EDGE OF THE LIGHTLY
ACCUMULATING SNOW IS MAKING STEADY PROGRESS EAST AND SHOULD SEE AN
END TO THREAT OF ACCUMULATIONS BY 10-11Z IN CHICAGO AREA AND BY
12Z OVER NW INDIANA. WHILE MOST OF THE SNOW SHOULD END JUST PRIOR
TO RUSH HOUR...RADAR AND SURFACE OBS UPSTREAM DO INDICATE A SOME
SCATTERED LINGERING FLURRIES NORTHWEST BACK TO THE TROUGH AXIS
OVER SOUTHERN WISCONSIN/NE IA AND SE MN. HAVE ADDED SOME FLURRIES
INTO THROUGH 15Z...THOUGH RAP RH PROGS SUGGEST THAT FLURRIES COULD
POTENTIALLY EVEN LINGER A BIT LONGER BUT WILL LET DAY SHIFT EXTEND
THE MENTION IF NEEDED. ONCE FLURRIES END SHOULD REMAIN CLOUDY
THROUGH THE REMAINDER OF THE SHORT TERM PERIOD WITH ONLY SMALL
DIURNAL SWINGS IN TEMPS. GIVEN THE EXPECTED CLOUD COVER AND WEAK
THERMAL ADVECTION HAVE LEANED TOWARD THE COOLER SIDE OF GUIDANCE
FOR HIGH TEMPS AND TOWARD THE WARMER SIDE OF GUIDANCE FOR LOW
TEMPS.
IZZI
&&
.LONG TERM...
313 AM CST
THURSDAY NIGHT THROUGH TUESDAY...
ABOUT THE ONLY THING TO TALK ABOUT IN THE LONG TERM IS THE LAKE
EFFECT POTENTIAL ON FRIDAY INTO FRIDAY EVENING.
OVERALL...CONTINUES TO LOOK LIKE A MARGINAL SET-UP AT BEST.
POWERFUL AND DEEPENING SOUTHERN STREAM CYCLONE TRACKING ACROSS THE
SOUTHEASTERN CONUS WILL RESULT IN AN INCREASING NORTH-NORTHEAST
FLOW DOWN THE FULL FETCH OF THE LAKE. DESPITE THE FAVORABLE WIND
DIRECTION AND THE FACT THAT MOST OF THE MODELS DO ATTEMPT TO SPIT
OUT SOME QPF...MOST OTHER FACTORS LOOK EITHER MARGINAL OR
UNFAVORABLE FOR LAKE EFFECT. STRONG SOUTHERN STORM SYSTEM IS NOT
PHASED WITH THE POLAR JET...SO WHILE IT IS TRACKING EAST MID-UPPER
LEVEL HEIGHTS ARE ALREADY RISING FRIDAY IN OUR NECK OF THE WOODS
AS NORTHERN STREAM SHORTWAVE RIDGING BUILDS EAST. THE RISING
HEIGHTS WILL ACT TO RE-ENFORCE SUBSIDENCE/FRONTAL INVERSION WHICH
IS PROGGED TO PEAK AROUND 5KFT AGL. AMBIENT TEMPS AT THE LAKE
INDUCED EQUILIBRIUM LEVEL ARE ONLY FORECAST TO BE IN THE -10 TO
-12C RANGE...SO ITS QUESTIONABLE IF ICE NUCLEI WILL EVEN BE
PRESENT FOR SNOW AND MORE LIKELY THAN NOT ANYTHING THAT FALLS
COULD BE LIGHT SNOW GRAIN SHOWERS. WHAT INSTABILITY THAT DOES
EXIST BELOW THE SHALLOW INVERSION IS ALSO WEAK AND NOT FAVORABLE
FOR LAKE EFFECT. GIVEN THE PERPONDERANCE OF THE EVIDENCE AGAINST
MEANINGFUL LAKE EFFECT SNOW HAVE MAINTAINED JUST LOW CHANCE POPS
FOR SOME LIGHT SNOW SHOWERS OR FLURRIES.
AFTER EXTENDED PERIOD OF CLOUD COVER LOOK FOR CLOUDINESS TO
GRADUALLY BREAK UP FOR A TIME OVER THE WEEKEND BRIEFLY. THE SLOW
MODERATION IN TEMPS WILL ALSO CONTINUE THROUGH THE WEEKEND...TO
THE POINT WE SHOULD BE A BIT ABOVE SEASONAL NORMS BY THE
WEEKEND...PARTICULARLY NIGHTTIME LOWS. WHILE DETAILS VARY IN HOW
IT EVOLVES...BOTH GFS AND ECMWF SUGGEST A SYSTEM WILL AFFECT THE
REGION EARLY NEXT WEEK. A BIT TOO FAR OUT AT THIS POINT TO PIN
DOWN P-TYPE AS IT DOES LOOK LIKE WE COULD END UP ON EITHER SIDE OF
THE RAIN/SNOW LINE DEPENDING ON EVENTUAL TRACK/INTENSITY OF THE
SYSTEM.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* LINGERING LIGHT SNOW/FLURRIES OVER THE NEXT 1-2 HOURS.
* MVFR CIGS REDEVELOPING.
KJB/RODRIGUEZ
//DISCUSSION...UPDATED 12Z...
THE ACCUMULATING SNOW HAS COME TO AN END. HOWEVER...A FEW
LINGERING FLURRIES COULD LINGER FOR THE NEXT FEW HOURS...BUT NO
IMPACTS ARE EXPECTED. OTHERWISE...IT APPEARS THAT A PERIOD OF VFR
CIGS OF 4-6 KFT AGL WILL BE THE RULE FOR THE NEXT FEW
HOURS...BEFORE SOME LOWER MVFR CIGS REDEVELOP OVER THE AREA BY
LATE MORNING. THESE LOWER CIGS COULD HANG ACROSS MUCH OF THE AREA
THROUGH THE DAY.
THERE IS A SMALL CHANCE OF SOME FOG DEVELOPMENT LATE
TONIGHT...PARTICULARLY AT KRFD AND KDPA. HOWEVER...THERE IS
UNCERTAINTY DUE TO THE POSSIBILITY OF CLOUD COVER. THEREFORE...I
HAVE LEFT THE MENTION OUT OF THE TAFS AT THIS TIME.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH WITH SNOW TRENDS.
* MEDIUM WITH CEILING TRENDS.
KJB/RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT...MAINLY VFR. LIGHT NORTH- NORTHEASTERLY WINDS.
FRIDAY...SLIGHT CHANCE OF LIGHT SNOW SHOWERS AND MVFR/IFR. BREEZY
NORTHEAST WINDS.
SATURDAY...VFR. NORTH-NORTHEAST WINDS TURNING SOUTHWEST.
SUNDAY...VFR. SOUTHWEST WINDS.
MONDAY...CHANCE OF RAIN OR SNOW AND MVFR/IFR.
TUESDAY...CHANCE OF SNOW. MVFR/IFR POSSIBLE.
KJB
&&
.MARINE...
100 AM CST
SURFACE HIGH PRESSURE WILL CONTINUE TO RESULT IN GENERALLY LIGHT
WESTERLY FLOW OVER THE LAKE THROUGH THURSDAY. HOWEVER...BY
FRIDAY...AN AREA OF LOW PRESSURE IS EXPECTED TO TRACK FROM THE
SOUTHERN MISSISSIPPI VALLEY EASTWARD OVER THE SOUTHEASTERN CONUS
AS A SURFACE RIDGE OF HIGH PRESSURE BUILDS SOUTHWARD OVER THE
UPPER GREAT LAKES. THIS LOOKS TO RESULT IN A PERIOD OF STRONGER
NORTHERLY WINDS...ESPECIALLY OVER THE SOUTHERN END OF THE
LAKE. THIS COULD RESULT IN THE NEED FOR ANOTHER SMALL CRAFT
ADVISORY FOR THE ILLINOIS AND INDIANA NEAR SHORES.
HOWEVER...THERE ARE UNCERTAINTIES ON WAVE HEIGHTS ALONG THE NEAR
SHORES DUE TO THE RECENT BUILD UP OF ICE. ICE TRENDS WILL NEED TO
BE MONITORED OVER THE NEXT COUPLE DAYS.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1003 AM CST WED JAN 20 2016
.SHORT TERM...
313 AM CST
THROUGH THURSDAY...
PRIMARY CONCERN IN THE SHORT TERM IS ESCORTING THE SNOW OUT OF THE
CWA IN THE GRIDS EARLY THIS MORNING. BACK EDGE OF THE LIGHTLY
ACCUMULATING SNOW IS MAKING STEADY PROGRESS EAST AND SHOULD SEE AN
END TO THREAT OF ACCUMULATIONS BY 10-11Z IN CHICAGO AREA AND BY
12Z OVER NW INDIANA. WHILE MOST OF THE SNOW SHOULD END JUST PRIOR
TO RUSH HOUR...RADAR AND SURFACE OBS UPSTREAM DO INDICATE A SOME
SCATTERED LINGERING FLURRIES NORTHWEST BACK TO THE TROUGH AXIS
OVER SOUTHERN WISCONSIN/NE IA AND SE MN. HAVE ADDED SOME FLURRIES
INTO THROUGH 15Z...THOUGH RAP RH PROGS SUGGEST THAT FLURRIES COULD
POTENTIALLY EVEN LINGER A BIT LONGER BUT WILL LET DAY SHIFT EXTEND
THE MENTION IF NEEDED. ONCE FLURRIES END SHOULD REMAIN CLOUDY
THROUGH THE REMAINDER OF THE SHORT TERM PERIOD WITH ONLY SMALL
DIURNAL SWINGS IN TEMPS. GIVEN THE EXPECTED CLOUD COVER AND WEAK
THERMAL ADVECTION HAVE LEANED TOWARD THE COOLER SIDE OF GUIDANCE
FOR HIGH TEMPS AND TOWARD THE WARMER SIDE OF GUIDANCE FOR LOW
TEMPS.
IZZI
&&
.LONG TERM...
313 AM CST
THURSDAY NIGHT THROUGH TUESDAY...
ABOUT THE ONLY THING TO TALK ABOUT IN THE LONG TERM IS THE LAKE
EFFECT POTENTIAL ON FRIDAY INTO FRIDAY EVENING.
OVERALL...CONTINUES TO LOOK LIKE A MARGINAL SET-UP AT BEST.
POWERFUL AND DEEPENING SOUTHERN STREAM CYCLONE TRACKING ACROSS THE
SOUTHEASTERN CONUS WILL RESULT IN AN INCREASING NORTH-NORTHEAST
FLOW DOWN THE FULL FETCH OF THE LAKE. DESPITE THE FAVORABLE WIND
DIRECTION AND THE FACT THAT MOST OF THE MODELS DO ATTEMPT TO SPIT
OUT SOME QPF...MOST OTHER FACTORS LOOK EITHER MARGINAL OR
UNFAVORABLE FOR LAKE EFFECT. STRONG SOUTHERN STORM SYSTEM IS NOT
PHASED WITH THE POLAR JET...SO WHILE IT IS TRACKING EAST MID-UPPER
LEVEL HEIGHTS ARE ALREADY RISING FRIDAY IN OUR NECK OF THE WOODS
AS NORTHERN STREAM SHORTWAVE RIDGING BUILDS EAST. THE RISING
HEIGHTS WILL ACT TO RE-ENFORCE SUBSIDENCE/FRONTAL INVERSION WHICH
IS PROGGED TO PEAK AROUND 5KFT AGL. AMBIENT TEMPS AT THE LAKE
INDUCED EQUILIBRIUM LEVEL ARE ONLY FORECAST TO BE IN THE -10 TO
-12C RANGE...SO ITS QUESTIONABLE IF ICE NUCLEI WILL EVEN BE
PRESENT FOR SNOW AND MORE LIKELY THAN NOT ANYTHING THAT FALLS
COULD BE LIGHT SNOW GRAIN SHOWERS. WHAT INSTABILITY THAT DOES
EXIST BELOW THE SHALLOW INVERSION IS ALSO WEAK AND NOT FAVORABLE
FOR LAKE EFFECT. GIVEN THE PERPONDERANCE OF THE EVIDENCE AGAINST
MEANINGFUL LAKE EFFECT SNOW HAVE MAINTAINED JUST LOW CHANCE POPS
FOR SOME LIGHT SNOW SHOWERS OR FLURRIES.
AFTER EXTENDED PERIOD OF CLOUD COVER LOOK FOR CLOUDINESS TO
GRADUALLY BREAK UP FOR A TIME OVER THE WEEKEND BRIEFLY. THE SLOW
MODERATION IN TEMPS WILL ALSO CONTINUE THROUGH THE WEEKEND...TO
THE POINT WE SHOULD BE A BIT ABOVE SEASONAL NORMS BY THE
WEEKEND...PARTICULARLY NIGHTTIME LOWS. WHILE DETAILS VARY IN HOW
IT EVOLVES...BOTH GFS AND ECMWF SUGGEST A SYSTEM WILL AFFECT THE
REGION EARLY NEXT WEEK. A BIT TOO FAR OUT AT THIS POINT TO PIN
DOWN P-TYPE AS IT DOES LOOK LIKE WE COULD END UP ON EITHER SIDE OF
THE RAIN/SNOW LINE DEPENDING ON EVENTUAL TRACK/INTENSITY OF THE
SYSTEM.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* LINGERING LIGHT SNOW/FLURRIES OVER THE NEXT 1-2 HOURS.
* MVFR CIGS REDEVELOPING.
KJB/RODRIGUEZ
//DISCUSSION...UPDATED 12Z...
THE ACCUMULATING SNOW HAS COME TO AN END. HOWEVER...A FEW
LINGERING FLURRIES COULD LINGER FOR THE NEXT FEW HOURS...BUT NO
IMPACTS ARE EXPECTED. OTHERWISE...IT APPEARS THAT A PERIOD OF VFR
CIGS OF 4-6 KFT AGL WILL BE THE RULE FOR THE NEXT FEW
HOURS...BEFORE SOME LOWER MVFR CIGS REDEVELOP OVER THE AREA BY
LATE MORNING. THESE LOWER CIGS COULD HANG ACROSS MUCH OF THE AREA
THROUGH THE DAY.
THERE IS A SMALL CHANCE OF SOME FOG DEVELOPMENT LATE
TONIGHT...PARTICULARLY AT KRFD AND KDPA. HOWEVER...THERE IS
UNCERTAINTY DUE TO THE POSSIBILITY OF CLOUD COVER. THEREFORE...I
HAVE LEFT THE MENTION OUT OF THE TAFS AT THIS TIME.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH WITH SNOW TRENDS.
* MEDIUM WITH CEILING TRENDS.
KJB/RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT...MAINLY VFR. LIGHT NORTH- NORTHEASTERLY WINDS.
FRIDAY...SLIGHT CHANCE OF LIGHT SNOW SHOWERS AND MVFR/IFR. BREEZY
NORTHEAST WINDS.
SATURDAY...VFR. NORTH-NORTHEAST WINDS TURNING SOUTHWEST.
SUNDAY...VFR. SOUTHWEST WINDS.
MONDAY...CHANCE OF RAIN OR SNOW AND MVFR/IFR.
TUESDAY...CHANCE OF SNOW. MVFR/IFR POSSIBLE.
KJB
&&
.MARINE...
100 AM CST
SURFACE HIGH PRESSURE WILL CONTINUE TO RESULT IN GENERALLY LIGHT
WESTERLY FLOW OVER THE LAKE THROUGH THURSDAY. HOWEVER...BY
FRIDAY...AN AREA OF LOW PRESSURE IS EXPECTED TO TRACK FROM THE
SOUTHERN MISSISSIPPI VALLEY EASTWARD OVER THE SOUTHEASTERN CONUS
AS A SURFACE RIDGE OF HIGH PRESSURE BUILDS SOUTHWARD OVER THE
UPPER GREAT LAKES. THIS LOOKS TO RESULT IN A PERIOD OF STRONGER
NORTHERLY WINDS...ESPECIALLY OVER THE SOUTHERN END OF THE
LAKE. THIS COULD RESULT IN THE NEED FOR ANOTHER SMALL CRAFT
ADVISORY FOR THE ILLINOIS AND INDIANA NEAR SHORES.
HOWEVER...THERE ARE UNCERTAINTIES ON WAVE HEIGHTS ALONG THE NEAR
SHORES DUE TO THE RECENT BUILD UP OF ICE. ICE TRENDS WILL NEED TO
BE MONITORED OVER THE NEXT COUPLE DAYS.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
813 AM CST WED JAN 20 2016
.SHORT TERM...
313 AM CST
THROUGH THURSDAY...
PRIMARY CONCERN IN THE SHORT TERM IS ESCORTING THE SNOW OUT OF THE
CWA IN THE GRIDS EARLY THIS MORNING. BACK EDGE OF THE LIGHTLY
ACCUMULATING SNOW IS MAKING STEADY PROGRESS EAST AND SHOULD SEE AN
END TO THREAT OF ACCUMULATIONS BY 10-11Z IN CHICAGO AREA AND BY
12Z OVER NW INDIANA. WHILE MOST OF THE SNOW SHOULD END JUST PRIOR
TO RUSH HOUR...RADAR AND SURFACE OBS UPSTREAM DO INDICATE A SOME
SCATTERED LINGERING FLURRIES NORTHWEST BACK TO THE TROUGH AXIS
OVER SOUTHERN WISCONSIN/NE IA AND SE MN. HAVE ADDED SOME FLURRIES
INTO THROUGH 15Z...THOUGH RAP RH PROGS SUGGEST THAT FLURRIES COULD
POTENTIALLY EVEN LINGER A BIT LONGER BUT WILL LET DAY SHIFT EXTEND
THE MENTION IF NEEDED. ONCE FLURRIES END SHOULD REMAIN CLOUDY
THROUGH THE REMAINDER OF THE SHORT TERM PERIOD WITH ONLY SMALL
DIURNAL SWINGS IN TEMPS. GIVEN THE EXPECTED CLOUD COVER AND WEAK
THERMAL ADVECTION HAVE LEANED TOWARD THE COOLER SIDE OF GUIDANCE
FOR HIGH TEMPS AND TOWARD THE WARMER SIDE OF GUIDANCE FOR LOW
TEMPS.
IZZI
&&
.LONG TERM...
313 AM CST
THURSDAY NIGHT THROUGH TUESDAY...
ABOUT THE ONLY THING TO TALK ABOUT IN THE LONG TERM IS THE LAKE
EFFECT POTENTIAL ON FRIDAY INTO FRIDAY EVENING.
OVERALL...CONTINUES TO LOOK LIKE A MARGINAL SET-UP AT BEST.
POWERFUL AND DEEPENING SOUTHERN STREAM CYCLONE TRACKING ACROSS THE
SOUTHEASTERN CONUS WILL RESULT IN AN INCREASING NORTH-NORTHEAST
FLOW DOWN THE FULL FETCH OF THE LAKE. DESPITE THE FAVORABLE WIND
DIRECTION AND THE FACT THAT MOST OF THE MODELS DO ATTEMPT TO SPIT
OUT SOME QPF...MOST OTHER FACTORS LOOK EITHER MARGINAL OR
UNFAVORABLE FOR LAKE EFFECT. STRONG SOUTHERN STORM SYSTEM IS NOT
PHASED WITH THE POLAR JET...SO WHILE IT IS TRACKING EAST MID-UPPER
LEVEL HEIGHTS ARE ALREADY RISING FRIDAY IN OUR NECK OF THE WOODS
AS NORTHERN STREAM SHORTWAVE RIDGING BUILDS EAST. THE RISING
HEIGHTS WILL ACT TO RE-ENFORCE SUBSIDENCE/FRONTAL INVERSION WHICH
IS PROGGED TO PEAK AROUND 5KFT AGL. AMBIENT TEMPS AT THE LAKE
INDUCED EQUILIBRIUM LEVEL ARE ONLY FORECAST TO BE IN THE -10 TO
-12C RANGE...SO ITS QUESTIONABLE IF ICE NUCLEI WILL EVEN BE
PRESENT FOR SNOW AND MORE LIKELY THAN NOT ANYTHING THAT FALLS
COULD BE LIGHT SNOW GRAIN SHOWERS. WHAT INSTABILITY THAT DOES
EXIST BELOW THE SHALLOW INVERSION IS ALSO WEAK AND NOT FAVORABLE
FOR LAKE EFFECT. GIVEN THE PERPONDERANCE OF THE EVIDENCE AGAINST
MEANINGFUL LAKE EFFECT SNOW HAVE MAINTAINED JUST LOW CHANCE POPS
FOR SOME LIGHT SNOW SHOWERS OR FLURRIES.
AFTER EXTENDED PERIOD OF CLOUD COVER LOOK FOR CLOUDINESS TO
GRADUALLY BREAK UP FOR A TIME OVER THE WEEKEND BRIEFLY. THE SLOW
MODERATION IN TEMPS WILL ALSO CONTINUE THROUGH THE WEEKEND...TO
THE POINT WE SHOULD BE A BIT ABOVE SEASONAL NORMS BY THE
WEEKEND...PARTICULARLY NIGHTTIME LOWS. WHILE DETAILS VARY IN HOW
IT EVOLVES...BOTH GFS AND ECMWF SUGGEST A SYSTEM WILL AFFECT THE
REGION EARLY NEXT WEEK. A BIT TOO FAR OUT AT THIS POINT TO PIN
DOWN P-TYPE AS IT DOES LOOK LIKE WE COULD END UP ON EITHER SIDE OF
THE RAIN/SNOW LINE DEPENDING ON EVENTUAL TRACK/INTENSITY OF THE
SYSTEM.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* LINGERING LIGHT SNOW OVER THE NEXT 1-2 HOURS...LOWEST VIS IN THE
3-5SM RANGE.
* MVFR CIGS REDEVELOPING BY LATE MORNING AND CONTINUING INTO THE
AFTERNOON.
KJB/RODRIGUEZ
//DISCUSSION...UPDATED 12Z...
THE ACCUMULATING SNOW HAS COME TO AN END. HOWEVER...A FEW
LINGERING FLURRIES COULD LINGER FOR THE NEXT FEW HOURS...BUT NO
IMPACTS ARE EXPECTED. OTHERWISE...IT APPEARS THAT A PERIOD OF VFR
CIGS OF 4-6 KFT AGL WILL BE THE RULE FOR THE NEXT FEW
HOURS...BEFORE SOME LOWER MVFR CIGS REDEVELOP OVER THE AREA BY
LATE MORNING. THESE LOWER CIGS COULD HANG ACROSS MUCH OF THE AREA
THROUGH THE DAY.
THERE IS A SMALL CHANCE OF SOME FOG DEVELOPMENT LATE
TONIGHT...PARTICULARLY AT KRFD AND KDPA. HOWEVER...THERE IS
UNCERTAINTY DUE TO THE POSSIBILITY OF CLOUD COVER. THEREFORE...I
HAVE LEFT THE MENTION OUT OF THE TAFS AT THIS TIME.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* HIGH WITH SNOW TRENDS.
* MEDIUM WITH CEILING TRENDS.
KJB/RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT...MAINLY VFR. LIGHT NORTH- NORTHEASTERLY WINDS.
FRIDAY...SLIGHT CHANCE OF LIGHT SNOW SHOWERS AND MVFR/IFR. BREEZY
NORTHEAST WINDS.
SATURDAY...VFR. NORTH-NORTHEAST WINDS TURNING SOUTHWEST.
SUNDAY...VFR. SOUTHWEST WINDS.
MONDAY...CHANCE OF RAIN OR SNOW AND MVFR/IFR.
TUESDAY...CHANCE OF SNOW. MVFR/IFR POSSIBLE.
KJB
&&
.MARINE...
100 AM CST
SURFACE HIGH PRESSURE WILL CONTINUE TO RESULT IN GENERALLY LIGHT
WESTERLY FLOW OVER THE LAKE THROUGH THURSDAY. HOWEVER...BY
FRIDAY...AN AREA OF LOW PRESSURE IS EXPECTED TO TRACK FROM THE
SOUTHERN MISSISSIPPI VALLEY EASTWARD OVER THE SOUTHEASTERN CONUS
AS A SURFACE RIDGE OF HIGH PRESSURE BUILDS SOUTHWARD OVER THE
UPPER GREAT LAKES. THIS LOOKS TO RESULT IN A PERIOD OF STRONGER
NORTHERLY WINDS...ESPECIALLY OVER THE SOUTHERN END OF THE
LAKE. THIS COULD RESULT IN THE NEED FOR ANOTHER SMALL CRAFT
ADVISORY FOR THE ILLINOIS AND INDIANA NEAR SHORES.
HOWEVER...THERE ARE UNCERTAINTIES ON WAVE HEIGHTS ALONG THE NEAR
SHORES DUE TO THE RECENT BUILD UP OF ICE. ICE TRENDS WILL NEED TO
BE MONITORED OVER THE NEXT COUPLE DAYS.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
510 AM CST WED JAN 20 2016
.SHORT TERM...
313 AM CST
THROUGH THURSDAY...
PRIMARY CONCERN IN THE SHORT TERM IS ESCORTING THE SNOW OUT OF THE
CWA IN THE GRIDS EARLY THIS MORNING. BACK EDGE OF THE LIGHTLY
ACCUMULATING SNOW IS MAKING STEADY PROGRESS EAST AND SHOULD SEE AN
END TO THREAT OF ACCUMULATIONS BY 10-11Z IN CHICAGO AREA AND BY
12Z OVER NW INDIANA. WHILE MOST OF THE SNOW SHOULD END JUST PRIOR
TO RUSH HOUR...RADAR AND SURFACE OBS UPSTREAM DO INDICATE A SOME
SCATTERED LINGERING FLURRIES NORTHWEST BACK TO THE TROUGH AXIS
OVER SOUTHERN WISCONSIN/NE IA AND SE MN. HAVE ADDED SOME FLURRIES
INTO THROUGH 15Z...THOUGH RAP RH PROGS SUGGEST THAT FLURRIES COULD
POTENTIALLY EVEN LINGER A BIT LONGER BUT WILL LET DAY SHIFT EXTEND
THE MENTION IF NEEDED. ONCE FLURRIES END SHOULD REMAIN CLOUDY
THROUGH THE REMAINDER OF THE SHORT TERM PERIOD WITH ONLY SMALL
DIURNAL SWINGS IN TEMPS. GIVEN THE EXPECTED CLOUD COVER AND WEAK
THERMAL ADVECTION HAVE LEANED TOWARD THE COOLER SIDE OF GUIDANCE
FOR HIGH TEMPS AND TOWARD THE WARMER SIDE OF GUIDANCE FOR LOW
TEMPS.
IZZI
&&
.LONG TERM...
313 AM CST
THURSDAY NIGHT THROUGH TUESDAY...
ABOUT THE ONLY THING TO TALK ABOUT IN THE LONG TERM IS THE LAKE
EFFECT POTENTIAL ON FRIDAY INTO FRIDAY EVENING.
OVERALL...CONTINUES TO LOOK LIKE A MARGINAL SET-UP AT BEST.
POWERFUL AND DEEPENING SOUTHERN STREAM CYCLONE TRACKING ACROSS THE
SOUTHEASTERN CONUS WILL RESULT IN AN INCREASING NORTH-NORTHEAST
FLOW DOWN THE FULL FETCH OF THE LAKE. DESPITE THE FAVORABLE WIND
DIRECTION AND THE FACT THAT MOST OF THE MODELS DO ATTEMPT TO SPIT
OUT SOME QPF...MOST OTHER FACTORS LOOK EITHER MARGINAL OR
UNFAVORABLE FOR LAKE EFFECT. STRONG SOUTHERN STORM SYSTEM IS NOT
PHASED WITH THE POLAR JET...SO WHILE IT IS TRACKING EAST MID-UPPER
LEVEL HEIGHTS ARE ALREADY RISING FRIDAY IN OUR NECK OF THE WOODS
AS NORTHERN STREAM SHORTWAVE RIDGING BUILDS EAST. THE RISING
HEIGHTS WILL ACT TO RE-ENFORCE SUBSIDENCE/FRONTAL INVERSION WHICH
IS PROGGED TO PEAK AROUND 5KFT AGL. AMBIENT TEMPS AT THE LAKE
INDUCED EQUILIBRIUM LEVEL ARE ONLY FORECAST TO BE IN THE -10 TO
-12C RANGE...SO ITS QUESTIONABLE IF ICE NUCLEI WILL EVEN BE
PRESENT FOR SNOW AND MORE LIKELY THAN NOT ANYTHING THAT FALLS
COULD BE LIGHT SNOW GRAIN SHOWERS. WHAT INSTABILITY THAT DOES
EXIST BELOW THE SHALLOW INVERSION IS ALSO WEAK AND NOT FAVORABLE
FOR LAKE EFFECT. GIVEN THE PERPONDERANCE OF THE EVIDENCE AGAINST
MEANINGFUL LAKE EFFECT SNOW HAVE MAINTAINED JUST LOW CHANCE POPS
FOR SOME LIGHT SNOW SHOWERS OR FLURRIES.
AFTER EXTENDED PERIOD OF CLOUD COVER LOOK FOR CLOUDINESS TO
GRADUALLY BREAK UP FOR A TIME OVER THE WEEKEND BRIEFLY. THE SLOW
MODERATION IN TEMPS WILL ALSO CONTINUE THROUGH THE WEEKEND...TO
THE POINT WE SHOULD BE A BIT ABOVE SEASONAL NORMS BY THE
WEEKEND...PARTICULARLY NIGHTTIME LOWS. WHILE DETAILS VARY IN HOW
IT EVOLVES...BOTH GFS AND ECMWF SUGGEST A SYSTEM WILL AFFECT THE
REGION EARLY NEXT WEEK. A BIT TOO FAR OUT AT THIS POINT TO PIN
DOWN P-TYPE AS IT DOES LOOK LIKE WE COULD END UP ON EITHER SIDE OF
THE RAIN/SNOW LINE DEPENDING ON EVENTUAL TRACK/INTENSITY OF THE
SYSTEM.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* MVFR CIGS REDEVELOPING BY LATE MORNING AND CONTINUING INTO THE
AFTERNOON.
KJB
//DISCUSSION...UPDATED 12Z...
THE ACCUMULATING SNOW HAS COME TO AN END. HOWEVER...A FEW
LINGERING FLURRIES COULD LINGER FOR THE NEXT FEW HOURS...BUT NO
IMPACTS ARE EXPECTED. OTHERWISE...IT APPEARS THAT A PERIOD OF VFR
CIGS OF 4-6 KFT AGL WILL BE THE RULE FOR THE NEXT FEW
HOURS...BEFORE SOME LOWER MVFR CIGS REDEVELOP OVER THE AREA BY
LATE MORNING. THESE LOWER CIGS COULD HANG ACROSS MUCH OF THE AREA
THROUGH THE DAY.
THERE IS A SMALL CHANCE OF SOME FOG DEVELOPMENT LATE
TONIGHT...PARTICULARLY AT KRFD AND KDPA. HOWEVER...THERE IS
UNCERTAINTY DUE TO THE POSSIBILITY OF CLOUD COVER. THEREFORE...I
HAVE LEFT THE MENTION OUT OF THE TAFS AT THIS TIME.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
HIGH FOR ALL ELEMENTS.
KJB
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT...MAINLY VFR. LIGHT NORTH- NORTHEASTERLY WINDS.
FRIDAY...SLIGHT CHANCE OF LIGHT SNOW SHOWERS AND MVFR/IFR. BREEZY
NORTHEAST WINDS.
SATURDAY...VFR. NORTH-NORTHEAST WINDS TURNING SOUTHWEST.
SUNDAY...VFR. SOUTHWEST WINDS.
MONDAY...CHANCE OF RAIN OR SNOW AND MVFR/IFR.
TUESDAY...CHANCE OF SNOW. MVFR/IFR POSSIBLE.
KJB
&&
.MARINE...
100 AM CST
SURFACE HIGH PRESSURE WILL CONTINUE TO RESULT IN GENERALLY LIGHT
WESTERLY FLOW OVER THE LAKE THROUGH THURSDAY. HOWEVER...BY
FRIDAY...AN AREA OF LOW PRESSURE IS EXPECTED TO TRACK FROM THE
SOUTHERN MISSISSIPPI VALLEY EASTWARD OVER THE SOUTHEASTERN CONUS
AS A SURFACE RIDGE OF HIGH PRESSURE BUILDS SOUTHWARD OVER THE
UPPER GREAT LAKES. THIS LOOKS TO RESULT IN A PERIOD OF STRONGER
NORTHERLY WINDS...ESPECIALLY OVER THE SOUTHERN END OF THE
LAKE. THIS COULD RESULT IN THE NEED FOR ANOTHER SMALL CRAFT
ADVISORY FOR THE ILLINOIS AND INDIANA NEAR SHORES.
HOWEVER...THERE ARE UNCERTAINTIES ON WAVE HEIGHTS ALONG THE NEAR
SHORES DUE TO THE RECENT BUILD UP OF ICE. ICE TRENDS WILL NEED TO
BE MONITORED OVER THE NEXT COUPLE DAYS.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
317 AM CST WED JAN 20 2016
.SHORT TERM...
313 AM CST
THROUGH THURSDAY...
PRIMARY CONCERN IN THE SHORT TERM IS ESCORTING THE SNOW OUT OF THE
CWA IN THE GRIDS EARLY THIS MORNING. BACK EDGE OF THE LIGHTLY
ACCUMULATING SNOW IS MAKING STEADY PROGRESS EAST AND SHOULD SEE AN
END TO THREAT OF ACCUMULATIONS BY 10-11Z IN CHICAGO AREA AND BY
12Z OVER NW INDIANA. WHILE MOST OF THE SNOW SHOULD END JUST PRIOR
TO RUSH HOUR...RADAR AND SURFACE OBS UPSTREAM DO INDICATE A SOME
SCATTERED LINGERING FLURRIES NORTHWEST BACK TO THE TROUGH AXIS
OVER SOUTHERN WISCONSIN/NE IA AND SE MN. HAVE ADDED SOME FLURRIES
INTO THROUGH 15Z...THOUGH RAP RH PROGS SUGGEST THAT FLURRIES COULD
POTENTIALLY EVEN LINGER A BIT LONGER BUT WILL LET DAY SHIFT EXTEND
THE MENTION IF NEEDED. ONCE FLURRIES END SHOULD REMAIN CLOUDY
THROUGH THE REMAINDER OF THE SHORT TERM PERIOD WITH ONLY SMALL
DIURNAL SWINGS IN TEMPS. GIVEN THE EXPECTED CLOUD COVER AND WEAK
THERMAL ADVECTION HAVE LEANED TOWARD THE COOLER SIDE OF GUIDANCE
FOR HIGH TEMPS AND TOWARD THE WARMER SIDE OF GUIDANCE FOR LOW
TEMPS.
IZZI
&&
.LONG TERM...
313 AM CST
THURSDAY NIGHT THROUGH TUESDAY...
ABOUT THE ONLY THING TO TALK ABOUT IN THE LONG TERM IS THE LAKE
EFFECT POTENTIAL ON FRIDAY INTO FRIDAY EVENING.
OVERALL...CONTINUES TO LOOK LIKE A MARGINAL SET-UP AT BEST.
POWERFUL AND DEEPENING SOUTHERN STREAM CYCLONE TRACKING ACROSS THE
SOUTHEASTERN CONUS WILL RESULT IN AN INCREASING NORTH-NORTHEAST
FLOW DOWN THE FULL FETCH OF THE LAKE. DESPITE THE FAVORABLE WIND
DIRECTION AND THE FACT THAT MOST OF THE MODELS DO ATTEMPT TO SPIT
OUT SOME QPF...MOST OTHER FACTORS LOOK EITHER MARGINAL OR
UNFAVORABLE FOR LAKE EFFECT. STRONG SOUTHERN STORM SYSTEM IS NOT
PHASED WITH THE POLAR JET...SO WHILE IT IS TRACKING EAST MID-UPPER
LEVEL HEIGHTS ARE ALREADY RISING FRIDAY IN OUR NECK OF THE WOODS
AS NORTHERN STREAM SHORTWAVE RIDGING BUILDS EAST. THE RISING
HEIGHTS WILL ACT TO RE-ENFORCE SUBSIDENCE/FRONTAL INVERSION WHICH
IS PROGGED TO PEAK AROUND 5KFT AGL. AMBIENT TEMPS AT THE LAKE
INDUCED EQUILIBRIUM LEVEL ARE ONLY FORECAST TO BE IN THE -10 TO
-12C RANGE...SO ITS QUESTIONABLE IF ICE NUCLEI WILL EVEN BE
PRESENT FOR SNOW AND MORE LIKELY THAN NOT ANYTHING THAT FALLS
COULD BE LIGHT SNOW GRAIN SHOWERS. WHAT INSTABILITY THAT DOES
EXIST BELOW THE SHALLOW INVERSION IS ALSO WEAK AND NOT FAVORABLE
FOR LAKE EFFECT. GIVEN THE PERPONDERANCE OF THE EVIDENCE AGAINST
MEANINGFUL LAKE EFFECT SNOW HAVE MAINTAINED JUST LOW CHANCE POPS
FOR SOME LIGHT SNOW SHOWERS OR FLURRIES.
AFTER EXTENDED PERIOD OF CLOUD COVER LOOK FOR CLOUDINESS TO
GRADUALLY BREAK UP FOR A TIME OVER THE WEEKEND BRIEFLY. THE SLOW
MODERATION IN TEMPS WILL ALSO CONTINUE THROUGH THE WEEKEND...TO
THE POINT WE SHOULD BE A BIT ABOVE SEASONAL NORMS BY THE
WEEKEND...PARTICULARLY NIGHTTIME LOWS. WHILE DETAILS VARY IN HOW
IT EVOLVES...BOTH GFS AND ECMWF SUGGEST A SYSTEM WILL AFFECT THE
REGION EARLY NEXT WEEK. A BIT TOO FAR OUT AT THIS POINT TO PIN
DOWN P-TYPE AS IT DOES LOOK LIKE WE COULD END UP ON EITHER SIDE OF
THE RAIN/SNOW LINE DEPENDING ON EVENTUAL TRACK/INTENSITY OF THE
SYSTEM.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 09Z...
* LIGHT SNOW ENDING BY 12 UTC.
KJB
//DISCUSSION...UPDATED 06Z...
A PERIOD OF LIGHT SNOW IS EXPECTED THROUGH JUST PRIOR TO DAYBREAK.
THE SNOW SHOULD BEGIN FALLING OVER THE EASTERN TERMINALS BY AROUND
07 UTC...WITH MAINLY 2 TO 3 SM VISBY LIKELY IN THE SNOW. HOWEVER...A
BRIEF PERIOD OR TWO OF VISIBILITIES UNDER 2 MILES IS POSSIBLE.
OTHERWISE...EXPECT MVFR CIGS TO PERSIST OVER THE AREA THROUGH AT
LEAST EARLY AFTERNOON BEFORE IMPROVING. WINDS DURING THE PERIOD WILL
REMAIN LIGHT...AROUND 5 KT OR LESS.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 09Z...
* HIGH WITH ALL ELEMENTS.
KJB
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
THURSDAY...MAINLY VFR. LIGHT EASTERLY WINDS.
FRIDAY...CHANCE OF LIGHT SNOW AND MVFR/IFR. BREEZY NORTHEAST
WINDS.
SATURDAY...VFR. NORTH-NORTHEAST WINDS TURNING SOUTHWEST.
SUNDAY...VFR. SOUTHWEST WINDS.
MONDAY...CHANCE OF RAIN OR SNOW AND MVFR/IFR. SOUTHWEST WINDS
TURNING NORTHWEST.
MDB
&&
.MARINE...
100 AM CST
SURFACE HIGH PRESSURE WILL CONTINUE TO RESULT IN GENERALLY LIGHT
WESTERLY FLOW OVER THE LAKE THROUGH THURSDAY. HOWEVER...BY
FRIDAY...AN AREA OF LOW PRESSURE IS EXPECTED TO TRACK FROM THE
SOUTHERN MISSISSIPPI VALLEY EASTWARD OVER THE SOUTHEASTERN CONUS
AS A SURFACE RIDGE OF HIGH PRESSURE BUILDS SOUTHWARD OVER THE
UPPER GREAT LAKES. THIS LOOKS TO RESULT IN A PERIOD OF STRONGER
NORTHERLY WINDS...ESPECIALLY OVER THE SOUTHERN END OF THE
LAKE. THIS COULD RESULT IN THE NEED FOR ANOTHER SMALL CRAFT
ADVISORY FOR THE ILLINOIS AND INDIAN NEAR SHORES. HOWEVER...THERE
ARE UNCERTAINTIES ON WAVE HEIGHTS ALONG THE NEAR SHORES DUE TO
THE RECENT BUILD UP OF ICE. ICE TRENDS WILL NEED TO BE MONITORED
OVER THE NEXT COUPLE DAYS.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
313 AM CST WED JAN 20 2016
.SHORT TERM...
313 AM CST
THROUGH THURSDAY...
PRIMARY CONCERN IN THE SHORT TERM IS ESCORTING THE SNOW OUT OF THE
CWA IN THE GRIDS EARLY THIS MORNING. BACK EDGE OF THE LIGHTLY
ACCUMULATING SNOW IS MAKING STEADY PROGRESS EAST AND SHOULD SEE AN
END TO THREAT OF ACCUMULATIONS BY 10-11Z IN CHICAGO AREA AND BY
12Z OVER NW INDIANA. WHILE MOST OF THE SNOW SHOULD END JUST PRIOR
TO RUSH HOUR...RADAR AND SURFACE OBS UPSTREAM DO INDICATE A SOME
SCATTERED LINGERING FLURRIES NORTHWEST BACK TO THE TROUGH AXIS
OVER SOUTHERN WISCONSIN/NE IA AND SE MN. HAVE ADDED SOME FLURRIES
INTO THROUGH 15Z...THOUGH RAP RH PROGS SUGGEST THAT FLURRIES COULD
POTENTIALLY EVEN LINGER A BIT LONGER BUT WILL LET DAY SHIFT EXTEND
THE MENTION IF NEEDED. ONCE FLURRIES END SHOULD REMAIN CLOUDY
THROUGH THE REMAINDER OF THE SHORT TERM PERIOD WITH ONLY SMALL
DIURNAL SWINGS IN TEMPS. GIVEN THE EXPECTED CLOUD COVER AND WEAK
THERMAL ADVECTION HAVE LEANED TOWARD THE COOLER SIDE OF GUIDANCE
FOR HIGH TEMPS AND TOWARD THE WARMER SIDE OF GUIDANCE FOR LOW
TEMPS.
IZZI
&&
.LONG TERM...
313 AM CST
THURSDAY NIGHT THROUGH TUESDAY...
ABOUT THE ONLY THING TO TALK ABOUT IN THE LONG TERM IS THE LAKE
EFFECT POTENTIAL ON FRIDAY INTO FRIDAY EVENING.
OVERALL...CONTINUES TO LOOK LIKE A MARGINAL SET-UP AT BEST.
POWERFUL AND DEEPENING SOUTHERN STREAM CYCLONE TRACKING ACROSS THE
SOUTHEASTERN CONUS WILL RESULT IN AN INCREASING NORTH-NORTHEAST
FLOW DOWN THE FULL FETCH OF THE LAKE. DESPITE THE FAVORABLE WIND
DIRECTION AND THE FACT THAT MOST OF THE MODELS DO ATTEMPT TO SPIT
OUT SOME QPF...MOST OTHER FACTORS LOOK EITHER MARGINAL OR
UNFAVORABLE FOR LAKE EFFECT. STRONG SOUTHERN STORM SYSTEM IS NOT
PHASED WITH THE POLAR JET...SO WHILE IT IS TRACKING EAST MID-UPPER
LEVEL HEIGHTS ARE ALREADY RISING FRIDAY IN OUR NECK OF THE WOODS
AS NORTHERN STREAM SHORTWAVE RIDGING BUILDS EAST. THE RISING
HEIGHTS WILL ACT TO RE-ENFORCE SUBSIDENCE/FRONTAL INVERSION WHICH
IS PROGGED TO PEAK AROUND 5KFT AGL. AMBIENT TEMPS AT THE LAKE
INDUCED EQUILIBRIUM LEVEL ARE ONLY FORECAST TO BE IN THE -10 TO
-12C RANGE...SO ITS QUESTIONABLE IF ICE NUCLEI WILL EVEN BE
PRESENT FOR SNOW AND MORE LIKELY THAN NOT ANYTHING THAT FALLS
COULD BE LIGHT SNOW GRAIN SHOWERS. WHAT INSTABILITY THAT DOES
EXIST BELOW THE SHALLOW INVERSION IS ALSO WEAK AND NOT FAVORABLE
FOR LAKE EFFECT. GIVEN THE PERPONDERANCE OF THE EVIDENCE AGAINST
MEANINGFUL LAKE EFFECT SNOW HAVE MAINTAINED JUST LOW CHANCE POPS
FOR SOME LIGHT SNOW SHOWERS OR FLURRIES.
AFTER EXTENDED PERIOD OF CLOUD COVER LOOK FOR CLOUDINESS TO
GRADUALLY BREAK UP FOR A TIME OVER THE WEEKEND BRIEFLY. THE SLOW
MODERATION IN TEMPS WILL ALSO CONTINUE THROUGH THE WEEKEND...TO
THE POINT WE SHOULD BE A BIT ABOVE SEASONAL NORMS BY THE
WEEKEND...PARTICULARLY NIGHTTIME LOWS. WHILE DETAILS VARY IN HOW
IT EVOLVES...BOTH GFS AND ECMWF SUGGEST A SYSTEM WILL AFFECT THE
REGION EARLY NEXT WEEK. A BIT TOO FAR OUT AT THIS POINT TO PIN
DOWN P-TYPE AS IT DOES LOOK LIKE WE COULD END UP ON EITHER SIDE OF
THE RAIN/SNOW LINE DEPENDING ON EVENTUAL TRACK/INTENSITY OF THE
SYSTEM.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* PERIOD OF SNOW WITH IFR VSBY OVERNIGHT.
KJB
//DISCUSSION...UPDATED 06Z...
A PERIOD OF LIGHT SNOW IS EXPECTED THROUGH JUST PRIOR TO DAYBREAK.
THE SNOW SHOULD BEGIN FALLING OVER THE EASTERN TERMINALS BY AROUND
07 UTC...WITH MAINLY 2 TO 3 SM VISBY LIKELY IN THE SNOW. HOWEVER...A
BRIEF PERIOD OR TWO OF VISIBILITIES UNDER 2 MILES IS POSSIBLE.
OTHERWISE...EXPECT MVFR CIGS TO PERSIST OVER THE AREA THROUGH AT
LEAST EARLY AFTERNOON BEFORE IMPROVING. WINDS DURING THE PERIOD WILL
REMAIN LIGHT...AROUND 5 KT OR LESS.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH WITH SNOW AND AT LEAST INTERMITTENT IFR VSBY OVERNIGHT.
KJB
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
THURSDAY...MAINLY VFR. LIGHT EASTERLY WINDS.
FRIDAY...CHANCE OF LIGHT SNOW AND MVFR/IFR. BREEZY NORTHEAST
WINDS.
SATURDAY...VFR. NORTH-NORTHEAST WINDS TURNING SOUTHWEST.
SUNDAY...VFR. SOUTHWEST WINDS.
MONDAY...CHANCE OF RAIN OR SNOW AND MVFR/IFR. SOUTHWEST WINDS
TURNING NORTHWEST.
MDB
&&
.MARINE...
100 AM CST
SURFACE HIGH PRESSURE WILL CONTINUE TO RESULT IN GENERALLY LIGHT
WESTERLY FLOW OVER THE LAKE THROUGH THURSDAY. HOWEVER...BY
FRIDAY...AN AREA OF LOW PRESSURE IS EXPECTED TO TRACK FROM THE
SOUTHERN MISSISSIPPI VALLEY EASTWARD OVER THE SOUTHEASTERN CONUS
AS A SURFACE RIDGE OF HIGH PRESSURE BUILDS SOUTHWARD OVER THE
UPPER GREAT LAKES. THIS LOOKS TO RESULT IN A PERIOD OF STRONGER
NORTHERLY WINDS...ESPECIALLY OVER THE SOUTHERN END OF THE
LAKE. THIS COULD RESULT IN THE NEED FOR ANOTHER SMALL CRAFT
ADVISORY FOR THE ILLINOIS AND INDIAN NEAR SHORES. HOWEVER...THERE
ARE UNCERTAINTIES ON WAVE HEIGHTS ALONG THE NEAR SHORES DUE TO
THE RECENT BUILD UP OF ICE. ICE TRENDS WILL NEED TO BE MONITORED
OVER THE NEXT COUPLE DAYS.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
326 AM EST WED JAN 20 2016
.SYNOPSIS...
ISSUED AT 326 AM EST WED JAN 20 2016
LIGHT SNOW WILL OVERSPREAD THE AREA THROUGH DAYBREAK BEFORE ENDING
WEST TO EAST MID TO LATE MORNING. SNOW ACCUMULATIONS OF AN INCH OR
LESS ARE EXPECTED NORTH OF HIGHWAY 30...WITH ONE TO TWO INCHES
SOUTH. HIGHS THIS AFTERNOON WILL RANGE THROUGH THE LOW 20S.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 326 AM EST WED JAN 20 2016
VIGOROUS NRN STREAM SW DROPPING SEWD THROUGH WRN WI ATTM WILL
MINOR OUT ACRS THE ERN LAKES TONIGHT. LL MSTR FLUX AHD OF THIS SYS
WANES W/NWD EXTENT INTO THE TEETH OF ERODING ARCTIC DOME AND
DELAYING TOP DOWN SATURATION TIMED W/STRONGEST MID LVL BASED
FORCING. HWVR -SN WILL OVERSPREAD MOST AREAS THROUGH
DAYBREAK...ALTHOUGH AMTS XPCD TO REMAIN TRIVIAL OWING TO WANING
MID LVL ASCENT AND OVERALL BRIEF DURATION (INCH OR LESS NORTH OF
30 AND 1-2 INCHES SOUTH) AND OF LTL CONCERN IN LIGHT OF GENERAL
MID TEEN SFC TEMPS. OTRWS SFC RIDGING TO REDVLP IN WAKE OF THIS
SYS OVERNIGHT HWVR CLDS XPCD TO PERSIST UNDERNEATH GROWING
SUBSIDENCE INDUCED THERMAL INVERSION.
&&
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 326 AM EST WED JAN 20 2016
QUIET/SEASONAL WX AND GRADUAL MODERATION ANTICIPATED THURSDAY-
SUNDAY...WITH NEXT DECENT OPPORTUNITY FOR PRECIPITATION EARLY NEXT
WEEK...
PROGRESSIVE FLOW PATTERN WILL PERSIST ALOFT THROUGH THE LONG TERM AS
SEVERAL UPPER LEVEL TROUGHS CREST WEST COAST RIDGE INTO
DOWNSTREAM/BROAD EASTERN CONUS TROUGH. FIRST DIGGING SHORTWAVE STILL
ON TARGET TO CLOSE OFF AND TAKE A MORE SOUTHERLY ROUTE THROUGH THE
SOUTHEAST US/MID ATLANTIC FRIDAY INTO SATURDAY. DEFORMATION PRECIP
SHIELD ON NORTHERN FRINGE WILL LIKELY PASS SOUTH AND EAST OF THE
LOCAL AREA...ALTHOUGH CLOUD CANOPY AND TIGHTENING LOW LEVEL HEIGHT
GRADIENT (INCREASING ENE FLOW) WILL STILL MAKE FOR A SOMEWHAT RAW
FRIDAY-EARLY SATURDAY. CLOUDS SHOULD SCOUR OUT WITH SOME WARMING
INTO SUNDAY AS RIDGING THROUGH THE COLUMN FOLDS IN. THE NEXT UPPER
TROUGH AND POTENTIAL FRONTAL WAVE DEVELOPMENT WILL PROVIDE THE NEXT
CHANCE FOR SNOW AND RAIN BY EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1243 AM EST WED JAN 20 2016
UPSTREAM CONDS ACRS NRN IL QUITE TELLING THIS MORNING AND CONFIRM
LATEST RAP TIME-HEIGHT CROSS SECTIONS INDICATING A SLOW TOP DOWN
SATURATION TAKING PLACE. THUS NO CHOICE BUT TO FOLLOW DAMPENED
RAP/HRRR BLEND W/ONSET OF -SN LTR THIS MORNING. BRIEF PD OF MVFR
RESTRICTION PSBL TIMED W/FINAL SATURATION/WANING ASCENT OVERLAP
YET XPC AN INCH OR LESS AT BOTH TERMINALS. LWR BOUND MVFR CIGS TO
PERSIST INTO AFTN BFR IMPROVING AS SFC TROUGH PASSES THROUGH ALG
W/INCREASING SUBSIDENCE YIELDING VFR CONDS LT PD.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$FISHER
SYNOPSIS...T
SHORT TERM...T
LONG TERM...STEINWEDEL
AVIATION...T
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AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1249 AM EST WED JAN 20 2016
.SYNOPSIS...
ISSUED AT 315 PM EST TUE JAN 19 2016
CLOUDS WILL INCREASE LATER THIS EVENING AHEAD OF A WEAK SYSTEM
THAT WILL SPREAD LIGHT SNOW ACROSS THE REGION LATE TONIGHT AND
WEDNESDAY MORNING. SNOW ACCUMULATIONS SHOULD BE UNDER TWO INCHES
WITH MANY LOCATIONS ONLY SEEING AN INCH OR LESS. TEMPERATURES
WILL SLOWLY WARM OVER THE NEXT SEVERAL DAYS...HEADING BACK TOWARDS
FREEZING BY THE WEEKEND.
&&
.UPDATE...
ISSUED AT 826 PM EST TUE JAN 19 2016
MAIN GRID ADJUSTMENT THIS EVE WAS TO LOWER MINS SEVERAL DEGREES
ACROSS NWRN PORTION OF CWA WHERE LIGHT WINDS AND FRESH SNOW COVER
WERE RESULTING IN A PERIOD OF STRONG RADIATIONAL COOLING. OTRWS
SLOWED TIMING OF APCHG SNOW SHIELD SLIGHTLY... BUT ACCUMS STILL
LOOK GOOD AND LIGHT SNOW STILL EXPECTED ACROSS MOST IF NOT ALL OF
THE CWA DURING THE MORNING COMMUTE TIME WED.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 313 PM EST TUE JAN 19 2016
SW FLOW AHEAD OF THE NEXT SYSTEM HAS PUSHED LAKE EFFECT THREAT
NORTH OF THE AREA. HIGH CLOUDS WERE STREAMING EASTWARD WITH AN
AREA OF LIGHT SNOW EXTENDING FROM NORTHERN IOWA TO WEST OF ST
LOUIS. MODELS HAVE TRENDED SOMEWHAT FASTER WITH ARRIVAL OF PRECIP
BUT WITH DRY AIRMASS IN PLACE THINK THEY HAVE GOTTEN CARRIED AWAY
WITH TIMING (6Z ONSET IN FAR SW). DID A GENERAL AVERAGE OF RUC
POPS AND PREVIOUS FORECAST TO TRY TO NUDGE UPWARD WITH ONSET BUT
KEEP REASONABLE. CONCERNS WITH REGARDS TO NORTHERN EXTENT OF
SNOWFALL AS MAIN FORCING REMAINS US 30 AND SOUTH WITH SFC LOW
PASSING WELL SOUTH OF THE AREA. RADAR TRENDS ACROSS N IOWA SEEM TO
BE WEAKENING AS WELL LEADING TO INCREASING CONCERN.
WITH REGARDS TO QPF/SNOW AMOUNTS...LARGE DENDRITIC GROWTH ZONE WILL
ARRIVE AT THE PEAK WITH A DEPTH OF MORE THAN 10,000 FT. THIS DEPTH
WILL BE NEEDED TO HELP MAKE UP FOR THE LACK OF SATURATION IN THE
SAME LAYER AND ONLY WEAK LIFT. ALL THESE FACTORS LEAD TO A
CONTINUATION OF LOW ACCUMULATIONS WITH LESS THAN AN INCH NORTH OF US
30 AND MAYBE UP TO AN INCH AND HALF SOUTH. WOULD NOT BE SURPRISED TO
SEE MICHIGAN COUNTIES GET LITTLE MORE THAN A FEW TENTHS OF AN INCH.
EVEN WITH THE LIGHT AMOUNTS...THERE MAY BE SOME MORNING TRAVEL
ISSUES GIVEN TIMING OF THE EVENT AND TENDENCIES FOR THESE LIGHT
EVENTS TO CAUSE MORE HEADACHES THAN SOME OF THE BIGGER ONES.
LOOKS LIKE SNOW SHOULD TRANSITION QUICKLY WEST TO EAST...POSSIBLY
BEGINNING TO EXIT THE AREA BY 12Z WEDS IN THE FAR WEST AND GONE BY
18Z EAST. HAVE MADE ONLY MINOR CHANGES TO PREVIOUS FORECAST BEYOND
12Z WITH TIMING ISSUES.
&&
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 313 PM EST TUE JAN 19 2016
OVERALL A QUIET LONG TERM PERIOD FOR MID JANUARY BUT A COUPLE
SYSTEMS TO WATCH.
HIGH PRESSURE WILL BE MOVING IN TO START THE PERIOD WEDNESDAY NIGHT.
WINDS WILL BECOME LIGHT OR CALM AS ANTICYCLONE CENTER DRIFTS INTO
THE AREA OVERNIGHT. WITH CLEARING SKIES AND LIGHT WINDS SHOULD SEE A
GOOD RADIATIONAL RESPONSE. HAVE LOWERED TEMPS A FEW DEGREES TOWARDS
THE LOWER END OF MOS. WOULD BE TEMPTED TO LOWER FURTHER IF MORE
SNOWFALL WAS EXPECTED WEDNESDAY. LIGHT ACCUMS ALONG WITH DEPARTING
COLD POCKET AND WARM AIR ADVECTION ALOFT PRECLUDES ANY ADDITIONAL
LOWERING AT THIS TIME.
NEXT FOCUS IS WITH STRONG CYCLOGENESIS EXPECTED TO TAKE PLACE FROM
THE MID SOUTH TO THE ATLANTIC COAST REGION FRIDAY INTO SATURDAY AS
SPLIT FLOW PHASES AND ENERGY TRANSFERS TO COASTAL LOW DEVELOPMENT.
NORTHERN STREAM SHORT WAVE RESPONSIBLE FOR INFUSING THIS SYSTEM WILL
DROP ACROSS OUR AREA FRIDAY. MODELS STILL HAVE DIFFERENCES ON WHERE
PERTINENT UPPER AIR FEATURES AND SFC LOW WILL TRACK BUT DEEPENING
SYSTEM WILL AID IN INCREASING EAST TO NORTHEAST LOW LEVEL FLOW
LOCALLY WHICH IN TANDEM WITH PASSING SHORT WAVE SHOULD HELP PULL
COLDER AIR AND MORE CLOUDS INTO THE FORECAST AREA FRIDAY. PCPN
CHANCES LOOK SMALL WITH MOISTURE STARVED SHORT WAVE THAT QUICKLY
GETS ABSORBED INTO SOUTHERN WAVE SO KEPT FORECAST DRY DESPITE THE
INCREASING MID LEVEL MOISTURE AND LOW LEVEL COLD AIR ADVECTION. ONCE
SYSTEM WRAPS AND DEEPENS WE WILL SEE SUBSIDENCE WITH INCREASING
SHORT WAVE RIDGING WITH CLEARING SKIES AND MODERATING TEMPS FOR
SATURDAY. AS WITH PREVIOUS SHIFT DID ALLOW A LOW CHANCE FOR LIGHT
SNOW TO CONTINUE IN THE FAR SOUTHEAST WITH ANY NORTHWARD ADJUSTMENT
STILL POSSIBLE.
NEXT DECENT CHANCE FOR PCPN LOCALLY WILL BE MONDAY OR TUESDAY WITH
WHAT APPEARS TO BE A COMPLICATED PARTIALLY PHASED SYSTEM. GFS ON THE
FASTER SIDE WHILE 12Z ECMWF SLOWER WITH MORE PCPN TUESDAY.
EXPECT ADDITIONAL CHANGES IN MODELS SO FEW CHANGES MADE AND
GENERALLY STAYED WITH INHERITED LOW CHANCE POPS FOR THE ENTIRE
PERIOD. COULD STILL BE A RAIN OR SNOW EVENT AS WELL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1243 AM EST WED JAN 20 2016
UPSTREAM CONDS ACRS NRN IL QUITE TELLING THIS MORNING AND CONFIRM
LATEST RAP TIME-HEIGHT CROSS SECTIONS INDICATING A SLOW TOP DOWN
SATURATION TAKING PLACE. THUS NO CHOICE BUT TO FOLLOW DAMPENED
RAP/HRRR BLEND W/ONSET OF -SN LTR THIS MORNING. BRIEF PD OF MVFR
RESTRICTION PSBL TIMED W/FINAL SATURATION/WANING ASCENT OVERLAP
YET XPC AN INCH OR LESS AT BOTH TERMINALS. LWR BOUND MVFR CIGS TO
PERSIST INTO AFTN BFR IMPROVING AS SFC TROUGH PASSES THROUGH ALG
W/INCREASING SUBSIDENCE YIELDING VFR CONDS LT PD.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
UPDATE...JT
SYNOPSIS...FISHER
SHORT TERM...FISHER
LONG TERM...LASHLEY
AVIATION...T
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AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1138 PM CST TUE JAN 19 2016
...AVIATION UPDATE...
.SYNOPSIS...
ISSUED AT 243 PM CST TUE JAN 19 2016
A SHRTWV TROF ADVECTING THROUGH NW FLOW LEAD TO SNOW ACROSS THE
IOWA AND N MO THIS AFTERNOON. SNOWFALL TOTALS OF 1 TO 4 INCHES
HAVE BEEN REPORTED IN SW IA INTO S CENTRAL IA. THIS FEATURE WILL
MOVE TO THE EAST THROUGH THE REST OF TODAY. AS THE COLUMN BEGINS
TO SATURATE...SNOW WILL OVERSPREAD THE CWA THIS EVENING.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 243 PM CST TUE JAN 19 2016
MAIN FORECAST CONCERN FOR THE SHORT TERM IS THE SNOW THIS
AFTERNOON AND INTO THE EVENING. GUIDANCE AND OBSERVATIONAL TRENDS
SUGGESTS THAT HEAVIEST SNOW...4+ INCHES...WILL OCCUR JUST TO THE
SOUTH OF THE CWA. AS A RESULT...UPDATED SNOW TOTALS AND CURRENT
CHANGES TO THE FORECAST WILL RESULT IN THE ADDITION OF MCDONOUGH
COUNTY IN THE WS.Y. THE BEST CHANCE FOR 3+ INCHES WILL BE SOUTH OF
A LINE FROM MACOMB TO KEOSAUQUA.
HIRES GUIDANCE....SPECIFICALLY THE HRRR AND HIRES NMM KEEPS THE
HEAVIEST SNOW TO OUR SOUTH THIS EVENING. THIS LINES UP WITH AN
OMEGA SIGNAL IN THE DGZ AS WELL. IT APPEARS THAT LIGHT SNOW WILL
OVERSPREAD THE AREA FROM WEST TO EAST. NEAR 00Z...AS THE OMEGA
INCREASES ACROSS THE SOUTH...SNOW INTENSITY SHOULD PICK UP. AT
THIS TIME...THE VORT WILL BE QUICKLY MOVING THROUGH LEADING TO A
QUICK END TO THE SNOW FROM WEST TO EAST. THINK THAT MOST OF THE
SNOW WILL BE OVER AOA 06Z WED. A LOOK AT THE FORECAST PLUMES
SUGGESTS THAT THE HIGHEST CONFIDENCE FOR 3+ INCHES WILL BE ACROSS
OUR EXTREME SOUTH. SNOW TOTALS SHOULD RAPIDLY DECREASE AS YOU
MOVE NORTH OF HWY 34 CORRIDOR WITH THE QC SEEING AROUND AN INCH
TOTAL. THIS IS SUPPORTED BY THE HIRES GUIDANCE AND ENSEMBLE
OUTPUT.
PAST THIS..IT LOOKS LIKE SOME OF THE WARMEST TEMPS IN THE PAST
COUPLE OF DAYS WILL BE TOMORROW WITH NO CHANCE OF POPS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 243 PM CST TUE JAN 19 2016
QUIET AND DRY CONDITIONS WILL BE SEEN ACROSS THE AREA WEDNESDAY
NIGHT THROUGH THURSDAY AS HIGH PRESSURE QUICKLY MOVES THROUGH THE
AREA. TEMPERATURES WILL AVERAGE BELOW NORMAL.
ON THURSDAY NIGHT...MAINLY DRY CONDITIONS ARE EXPECTED AS THE HIGH
MOVES INTO THE OHIO VALLEY. A WEAK DISTURBANCE MOVING THROUGH THE
UPPER MIDWEST MAY BRING SOME FLURRIES OR VERY LIGHT SNOW TO THE
HIGHWAY 20 CORRIDOR WEST OF DUBUQUE.
DRY CONDITIONS WILL THEN BE SEEN ACROSS THE AREA ON FRIDAY AS
ANOTHER HIGH PRESSURE BUILDS INTO THE MIDWEST. TEMPERATURES WILL BE
SLIGHTLY BELOW NORMAL.
FRIDAY NIGHT ON...
THE MODEL CONSENSUS HAS DRY CONDITIONS FRIDAY NIGHT THROUGH SUNDAY
AS HIGH PRESSURE MOVES INTO THE OHIO VALLEY. TEMPERATURES WILL
SLOWLY CLIMB TO ABOVE NORMAL ON SUNDAY. ATTENTION THEN TURNS TO A
POTENTIAL STORM SYSTEM.
SUNDAY NIGHT INTO MONDAY THE MODELS DIVERGE ON THEIR RESPECTIVE
SOLUTIONS. THE ECMWF IS DRY BUT THE GEM AND TO A MUCH LESSER EXTENT
THE GFS SUGGEST A WEAK STORM SYSTEM MOVING THROUGH THE AREA. GIVEN
THE CONSIDERABLE DIFFERENCES...THE MODEL CONSENSUS HAS SLIGHT CHANCE
POPS FOR SUNDAY NIGHT AND MONDAY.
MONDAY NIGHT AND TUESDAY THE MODEL CONSENSUS HAS DRY CONDITIONS AS
HIGH PRESSURE BUILDS INTO THE MIDWEST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1134 PM CST TUE JAN 19 2016
LIGHT SNOW WILL END...OR DIMINISH TO NON ACCUMULATING FLURRIES
BETWEEN 05Z AND 07Z THIS EVENING. AS THE SNOW ENDS...MVFR CIGS
WILL LIFT TO VFR FOR A SHORT PERIOD...BEFORE LIKELY DROPPING TO
THE 600 TO 1500 FT RANGE FOR THE EARLY MORNING THROUGH MID MORNING
HOURS WEDNESDAY. THIS WILL BE DUE TO SATURATED LOW LEVELS IN THE
WAKE OF THE EVENING SNOW EVENT AND PERSISTENT LIGHT SOUTHEAST
WIND. I WILL SHOW SOME MODEST IMPROVEMENT DURING THE DAY
WEDNESDAY...BUT DO NOT EXPECT WIDESPREAD VFR THROUGH THE PERIOD.
ERVIN
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR LEE-VAN
BUREN.
IL...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR HANCOCK-
MCDONOUGH.
MO...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR CLARK-
SCOTLAND.
&&
$$
SYNOPSIS...GIBBS
SHORT TERM...GIBBS
LONG TERM...08
AVIATION...ERVIN
AREA FORECAST DISCUSSION...CORRECTED
NWS GOODLAND KS
231 PM MST WED JAN 20 2016
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 132 PM MST WED JAN 20 2016
WV IMAGERY AND RAP H5/H7 ANALYSIS SHOWS TWO SHORTWAVE TROUGHS
IMPACTING THE CENTRAL ROCKIES AND PLAINS. THE STRONGER CLOSED CENTER
JUST EAST OF OUR CWA OVER NORTH CENTRAL KANSAS AND HAS DEEPENED
THROUGH MIDDAY. THE SECOND IS ENTERING EASTERN COLORADO. BETWEEN
THESE FEATURES THERE IS A SHORTWAVE RIDGE AND REGION OF
DRY/SUBSIDENT AIR APPARENT ON WV IMAGERY. AT THE SURFACE...A SURFACE
TROUGH IS IN PLACE OVER EASTERN COLORADO AND WHERE SKIES HAVE
CLEARED TEMPS HAVE WARMED IN TO THE 40S/50S. OVER OUR CWA (EAST OF
TROUGH AXIS) EXTENSIVE CLOUD COVER HAS SIGNIFICANTLY LIMITED HEATING
AND SEVERAL UPDATES TO HIGH TEMPS WERE WARRANTED EARLIER TODAY.
THIS AFTERNOON-THURSDAY...FOCUS CONTINUES TO BE ON POTENTIAL FOR
SNOW ACROSS OUR CWA. RADAR IS SHOWING SIGNS OF INCREASE IN
REFLECTIVITY IN OUR EASTERN CWA AND HILL CITY HAS STARTED TO REPORT
LIGHT SNOW. THIS CORRELATES WITH OF STRONG VORTICITY NEAR CLOSED LOW
CENTER AND BETTER MID LEVEL MOISTURE IS BEGINNING TO FILL IT. TREND
WILL BE FOR THIS CENTER TO ROTATE NORTH AND EAST TONIGHT BEFORE
SLIDING WELL EAST OF OUR CWA. AN ELEVATED BAROCLINIC ZONE/REGION OF
WEAK FRONTOGENESIS WILL DEVELOP AS THESE SHORTWAVE INTERACT AND PLACE
THE NORTHERN HALF OF OUR CWA IN A FAVORABLE LOCATION FOR POSSIBLE
LIGHT SNOW DEVELOPMENT BY THURSDAY MORNING. THE LIMITING FACTOR WILL
BE MOISTURE ADVECTION AS BOTH SHORTWAVE WILL TEND TO CUT OFF GULF
MOISTURE AND MODELS HAVE GENERALLY LIMITED QPF OVER OUR CWA
ACCORDINGLY. IN THE MEAN TIME...THE DRY/SUBSIDENT REGION BETWEEN
FEATURES MAY LIMIT ANY SNOW DEVELOPMENT IN OUR SOUTH.
I FAVORED THE EASTERN/NORTHEAST PART OF OUR CWA TONIGHT AND
THURSDAY MORNING FOR HIGHEST POPS. SNOW TOTALS SHOULD GENERALLY
RANGE 0.5-1" THOUGH IF THE EASTERN SHORTWAVE WERE TO REMAIN CLOSER
TO OUR CWA WE MAY HAVE A ROW OF COUNTIES RECEIVE AROUND 2" WHEN ALL
IS SAID AND DONE. ALL SNOWFALL SHOULD QUICKLY DISSIPATE/TRANSITION
EASTWARD AS THE RESULTING COMBINED TROUGH SHIFTS EAST AND RIDGING
BUILDS INTO OUR CWA THURSDAY AFTERNOON.
MODELS CONTINUE TO SHOW STRONGER BL WINDS DEVELOPING ON BACK SIDE OF
UPPER LOW AS THE TWO SHORTWAVES MERGE AND POST FRONTAL PRESSURE
GRADIENT INCREASES. LOCATION OF STRONGEST WINDS ACTUALLY CORRELATES
WITH MOST LIKELY LOCATION OF DRY SLOT DEVELOPMENT AND ABOVE
FREEZING TEMPERATURES DURING THE DAY THURSDAY. MIXING MAY BE LIMITED
IN LOCATIONS WITH CLOUD COVER/SNOW AND BL WINDS ARE LESS TO THE
NORTHEAST WHERE SNOWFALL IS MOST LIKELY. SINCE STRONGEST WINDS ARE
UNLIKELY TO BE LOCATED WITH BETTER SNOW CHANCES AND ACCUMULATIONS
ARE LIGHT I DID NOT SEE THE NEED TO KEEP BLOWING SNOW IN THE
FORECAST. AT MOST WE MAY SEE A BRIEF PERIOD OF DRIFTING SNOW AS SNOW
WINDS DOWN BEFORE TEMPS INCREASE TO FREEZING (OR WARMER). ANY
DRIFTING WOULD BE MINOR CONSIDERING AMOUNTS WE ARE DEALING WITH AS
WELL AS PEAK GUSTS IN THE REGION OF BETTER LIGHT SNOW ACCUMULATIONS
20-25 MPH.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 132 PM MST WED JAN 20 2016
THERE ARE A COUPLE OF FORECAST CONCERNS IN THE LONG TERM PERIOD.
FIRST IS THE TEMPERATURE GRADIENT ACROSS THE FORECAST AREA
THROUGH THE END OF THE WEEK AND INTO THE WEEKEND AS COOLER AIR
MOVES EAST AND WARMER DOWNSLOPING CONDITIONS OCCUR OVER THE WEST.
SECOND IS THE POSSIBILITY AND TYPE OF PRECIPITATION LATE SUNDAY
THROUGH EARLY MONDAY MORNING AS THE WARM AND DRY PATTERN
TRANSITIONS BRIEFLY BACK TO A COOLER AND MORE ACTIVE PATTERN AS A
SERIES OF DISTURBANCES MOVES ACROSS THE REGION LATE IN THE WEEKEND
THROUGH EARLY NEXT WEEK.
THE UPPER RIDGE MOVES EAST OVER THE HIGH PLAINS ON THURSDAY NIGHT
THROUGH FRIDAY NIGHT AND CONTINUES OVER THE EASTERN PLAINS STATES
ON SATURDAY. THE COOLER AREA OF HIGH PRESSURE AT THE SURFACE MOVES
INTO THE PLAINS STATES BY FRIDAY...WITH A LEE TROUGH DEEPENING
ALONG THE FRONT RANGE IN RESPONSE TO THE FLATTENING UPPER FLOW AS
AS SEVERAL SHORT WAVE TROUGHS MOVE THROUGH THE UPPER FLOW
SATURDAY NIGHT AHEAD OF THE NEXT MAIN UPPER TROUGH AXIS. THIS WILL
KEEP THE COOLER AIR OVER THE FAR EASTERN SECTIONS OF THE FORECAST
AREA AS THE WESTERN SECTIONS WARM UP. THE THURSDAY NIGHT THROUGH
SATURDAY NIGHT TIME PERIOD WILL STAY DRY AS A RESULT. HOWEVER...THE
TEMPERATURE GRADIENT ACROSS MY FORECAST AREA IS USUALLY MORE
DRAMATIC THAN DEPICTED BY ANY MODEL SOLUTIONS AND HAVE THEREFORE
TRIED TO GO TOWARDS THE WARM END OF GUIDANCE OVER THE WEST AND
TOWARDS THE COOL END OF GUIDANCE OVER THE EAST TO MAKE THE
GRADIENT MORE DRAMATIC. ANY RELUCTANCE OF LOW CLOUD COVER TO
DISSIPATE OVER THE EASTERN SECTIONS...AS HAS BEEN THE CASE OVER
RECENT DAYS...WILL ALSO ACT TO INCREASE THE TEMPERATURE GRADIENT.
A SURFACE LOW CONSOLIDATES OVER THE NORTHERN PANHANDLE REGION ON
SUNDAY...LIFTING INTO MISSOURI BY MONDAY MORNING ALONG THE
FRONTAL BOUNDARY EXTENDING FROM THE GREAT LAKES INTO THE SOUTHERN
PLAINS AS THE MAIN UPPER TROUGH AXIS MOVES EAST OF THE ROCKIES BY
SUNDAY AFTERNOON. A DEEPER AND BROADER UPPER TROUGH IS EVENTUALLY
CARVED OUT OVER MUCH OF THE UNITED STATES EAST OF THE ROCKIES BY
MONDAY NIGHT AS ANOTHER RIDGE MOVES INTO PLACE OVER THE WEST
COAST. THIS WILL OPEN THE DOOR TO COLDER AIR DIVING SOUTH INTO THE
PLAINS STATES ON MONDAY. WITH THE TRACK OF THE SURFACE LOW
REMAINING WELL SOUTH OF THE FORECAST AREA AND LITTLE MOISTURE TO
WORK WITH...EXPECT ONLY A SLIGHT CHANCE OF LIGHT RAIN OR SNOW
LATE SUNDAY TRANSITIONING TO ALL SNOW SUNDAY EVENING...WITH
MINIMAL ACCUMULATIONS POSSIBLE MAINLY ACROSS SOUTHERN NEBRASKA AND
EASTERN COLORADO.
THE UPPER WEST COAST RIDGE FLATTENS AND MOVES EAST OVER THE
MOUNTAINOUS WEST BETWEEN SUNDAY AND WEDNESDAY WITH ANOTHER LEE
TROUGH DEEPENING ALONG THE FRONT RANGE. WESTERLY NEAR SURFACE
FLOW WILL PRODUCE DRYING CONDITIONS AND WARMING TEMPERATURES
AGAIN OVER THE FORECAST AREA ON TUESDAY AND WEDNESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1026 AM MST WED JAN 20 2016
BASED ON RECENT TRENDS WITH OBS AND SUPPORTED BY SHORT RANGE
GUIDANCE IFR CIGS/VIS SHOULD IMPROVE TO VFR DURING THE EARLY PART
OF THE TAF PERIOD. A COLD FRONT WILL MOVE THROUGH THE REGION LATE
THIS EVENING WITH WINDS SHIFTING TO THE NORTHWEST AND INCREASING
THROUGH THE NIGHT. STRATUS WILL ONCE AGAIN DEVELOP BEHIND THIS
FRONT LATE TONIGHT AND THURSDAY MORNING...AND THERE COULD BE A FEW
SNOW SHOWERS AROUND THE REGION. THERE IS STILL ENOUGH UNCERTAINTY
IN SNOW COVERAGE I WAS MOST COMFORTABLE LIMITING MENTION TO VCSH
THURSDAY MORNING AT KMCK WHERE BETTER CHANCES ARE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...LOCKHART
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
219 PM MST WED JAN 20 2016
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 132 PM MST WED JAN 20 2016
WV IMAGERY AND RAP H5/H7 ANALYSIS SHOWS TWO SHORTWAVE TROUGHS
IMPACTING THE CENTRAL ROCKIES AND PLAINS. THE STRONGER CLOSED CENTER
JUST EAST OF OUR CWA OVER NORTH CENTRAL KANSAS AND HAS DEEPENED
THROUGH MIDDAY. THE SECOND IS ENTERING EASTERN COLORADO. BETWEEN
THESE FEATURES THERE IS A SHORTWAVE RIDGE AND REGION OF
DRY/SUBSIDENT AIR APPARENT ON WV IMAGERY. AT THE SURFACE...A SURFACE
TROUGH IS IN PLACE OVER EASTERN COLORADO AND WHERE SKIES HAVE
CLEARED TEMPS HAVE WARMED IN TO THE 40S/50S. OVER OUR CWA (EAST OF
TROUGH AXIS) EXTENSIVE CLOUD COVER HAS SIGNIFICANTLY LIMITED HEATING
AND SEVERAL UPDATES TO HIGH TEMPS WERE WARRANTED EARLIER TODAY.
THIS AFTERNOON-THURSDAY...FOCUS CONTINUES TO BE ON POTENTIAL FOR
SNOW ACROSS OUR CWA. RADAR IS SHOWING SIGNS OF INCREASE IN
REFLECTIVITY IN OUR EASTERN CWA AND HILL CITY HAS STARTED TO REPORT
LIGHT SNOW. THIS CORRELATES WITH OF STRONG VORTICITY NEAR CLOSED LOW
CENTER AND BETTER MID LEVEL MOISTURE IS BEGINNING TO FILL IT. TREND
WILL BE FOR THIS CENTER TO ROTATE NORTH AND EAST TONIGHT BEFORE
SLIDING WELL EAST OF OUR CWA. AN ELEVATED BAROCLINIC ZONE/REGION OF
WEAK FRONTOGENESIS WILL DEVELOP AS THESE SHORTWAVE INTERACT AND PLACE
THE NORTHERN HALF OF OUR CWA IN A FAVORABLE LOCATION FOR POSSIBLE
LIGHT SNOW DEVELOPMENT BY THURSDAY MORNING. THE LIMITING FACTOR WILL
BE MOISTURE ADVECTION AS BOTH SHORTWAVE WILL TEND TO CUT OFF GULF
MOISTURE AND MODELS HAVE GENERALLY LIMITED QPF OVER OUR CWA
ACCORDINGLY. IN THE MEAN TIME...THE DRY/SUBSIDENT REGION BETWEEN
FEATURES MAY LIMIT ANY SNOW DEVELOPMENT IN OUR SOUTH.
I FAVORED THE EASTERN/NORTHEAST PART OF OUR CWA TONIGHT AND
THURSDAY MORNING FOR HIGHEST POPS. SNOW TOTALS SHOULD GENERALLY
RANGE 0.5-1" THOUGH IF THE EASTERN SHORTWAVE WERE TO REMAIN CLOSER
TO OUR CWA WE MAY HAVE A ROW OF COUNTIES RECEIVE AROUND 2" WHEN ALL
IS SAID AND DONE. ALL SNOWFALL SHOULD QUICKLY DISSIPATE/TRANSITION
EASTWARD AND THE RESULTING COMBINED TROUGH SHIFTS EAST AND RIDING
BUILDS INTO OUR CWA THURSDAY.
MODELS CONTINUE TO SHOW STRONGER BL WINDS DEVELOPING ON BACK SIDE OF
UPPER LOW AS THE TWO SHORTWAVES MERGE AND POST FRONTAL PRESSURE
GRADIENT INCREASES. LOCATION OF STRONGEST WINDS ACTUALLY CORRELATES
WITH MOST LIKELY LOCATION OF DRY SLOT DEVELOPMENT AND ABOVE
FREEZING TEMPERATURES DURING THE DAY THURSDAY. MIXING MAY BE LIMITED
IN LOCATIONS WITH CLOUD COVER/SNOW AND BL WINDS ARE LESS TO THE
NORTHEAST WHERE SNOWFALL IS MOST LIKELY. SINCE STRONGEST WINDS ARE
UNLIKELY TO BE LOCATED WITH BETTER SNOW CHANCES AND ACCUMULATIONS
ARE LIGHT I DID NOT SEE THE NEED TO KEEP BLOWING SNOW IN THE
FORECAST. AT MOST WE MAY SEE A BRIEF PERIOD OF DRIFTING SNOW AS SNOW
WINDS DOWN BEFORE TEMPS INCREASE TO FREEZING (OR WARMER). ANY
DRIFTING WOULD BE MINOR AS WELL WITH PEAK GUSTS IN THE REGION OF
BETTER LIGHT SNOW ACCUMULATIONS 20-25 MPH.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 132 PM MST WED JAN 20 2016
THERE ARE A COUPLE OF FORECAST CONCERNS IN THE LONG TERM PERIOD.
FIRST IS THE TEMPERATURE GRADIENT ACROSS THE FORECAST AREA
THROUGH THE END OF THE WEEK AND INTO THE WEEKEND AS COOLER AIR
MOVES EAST AND WARMER DOWNSLOPING CONDITIONS OCCUR OVER THE WEST.
SECOND IS THE POSSIBILITY AND TYPE OF PRECIPITATION LATE SUNDAY
THROUGH EARLY MONDAY MORNING AS THE WARM AND DRY PATTERN
TRANSITIONS BRIEFLY BACK TO A COOLER AND MORE ACTIVE PATTERN AS A
SERIES OF DISTURBANCES MOVES ACROSS THE REGION LATE IN THE WEEKEND
THROUGH EARLY NEXT WEEK.
THE UPPER RIDGE MOVES EAST OVER THE HIGH PLAINS ON THURSDAY NIGHT
THROUGH FRIDAY NIGHT AND CONTINUES OVER THE EASTERN PLAINS STATES
ON SATURDAY. THE COOLER AREA OF HIGH PRESSURE AT THE SURFACE MOVES
INTO THE PLAINS STATES BY FRIDAY...WITH A LEE TROUGH DEEPENING
ALONG THE FRONT RANGE IN RESPONSE TO THE FLATTENING UPPER FLOW AS
AS SEVERAL SHORT WAVE TROUGHS MOVE THROUGH THE UPPER FLOW
SATURDAY NIGHT AHEAD OF THE NEXT MAIN UPPER TROUGH AXIS. THIS WILL
KEEP THE COOLER AIR OVER THE FAR EASTERN SECTIONS OF THE FORECAST
AREA AS THE WESTERN SECTIONS WARM UP. THE THURSDAY NIGHT THROUGH
SATURDAY NIGHT TIME PERIOD WILL STAY DRY AS A RESULT. HOWEVER...THE
TEMPERATURE GRADIENT ACROSS MY FORECAST AREA IS USUALLY MORE
DRAMATIC THAN DEPICTED BY ANY MODEL SOLUTIONS AND HAVE THEREFORE
TRIED TO GO TOWARDS THE WARM END OF GUIDANCE OVER THE WEST AND
TOWARDS THE COOL END OF GUIDANCE OVER THE EAST TO MAKE THE
GRADIENT MORE DRAMATIC. ANY RELUCTANCE OF LOW CLOUD COVER TO
DISSIPATE OVER THE EASTERN SECTIONS...AS HAS BEEN THE CASE OVER
RECENT DAYS...WILL ALSO ACT TO INCREASE THE TEMPERATURE GRADIENT.
A SURFACE LOW CONSOLIDATES OVER THE NORTHERN PANHANDLE REGION ON
SUNDAY...LIFTING INTO MISSOURI BY MONDAY MORNING ALONG THE
FRONTAL BOUNDARY EXTENDING FROM THE GREAT LAKES INTO THE SOUTHERN
PLAINS AS THE MAIN UPPER TROUGH AXIS MOVES EAST OF THE ROCKIES BY
SUNDAY AFTERNOON. A DEEPER AND BROADER UPPER TROUGH IS EVENTUALLY
CARVED OUT OVER MUCH OF THE UNITED STATES EAST OF THE ROCKIES BY
MONDAY NIGHT AS ANOTHER RIDGE MOVES INTO PLACE OVER THE WEST
COAST. THIS WILL OPEN THE DOOR TO COLDER AIR DIVING SOUTH INTO THE
PLAINS STATES ON MONDAY. WITH THE TRACK OF THE SURFACE LOW
REMAINING WELL SOUTH OF THE FORECAST AREA AND LITTLE MOISTURE TO
WORK WITH...EXPECT ONLY A SLIGHT CHANCE OF LIGHT RAIN OR SNOW
LATE SUNDAY TRANSITIONING TO ALL SNOW SUNDAY EVENING...WITH
MINIMAL ACCUMULATIONS POSSIBLE MAINLY ACROSS SOUTHERN NEBRASKA AND
EASTERN COLORADO.
THE UPPER WEST COAST RIDGE FLATTENS AND MOVES EAST OVER THE
MOUNTAINOUS WEST BETWEEN SUNDAY AND WEDNESDAY WITH ANOTHER LEE
TROUGH DEEPENING ALONG THE FRONT RANGE. WESTERLY NEAR SURFACE
FLOW WILL PRODUCE DRYING CONDITIONS AND WARMING TEMPERATURES
AGAIN OVER THE FORECAST AREA ON TUESDAY AND WEDNESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1026 AM MST WED JAN 20 2016
BASED ON RECENT TRENDS WITH OBS AND SUPPORTED BY SHORT RANGE
GUIDANCE IFR CIGS/VIS SHOULD IMPROVE TO VFR DURING THE EARLY PART
OF THE TAF PERIOD. A COLD FRONT WILL MOVE THROUGH THE REGION LATE
THIS EVENING WITH WINDS SHIFTING TO THE NORTHWEST AND INCREASING
THROUGH THE NIGHT. STRATUS WILL ONCE AGAIN DEVELOP BEHIND THIS
FRONT LATE TONIGHT AND THURSDAY MORNING...AND THERE COULD BE A FEW
SNOW SHOWERS AROUND THE REGION. THERE IS STILL ENOUGH UNCERTAINTY
IN SNOW COVERAGE I WAS MOST COMFORTABLE LIMITING MENTION TO VCSH
THURSDAY MORNING AT KMCK WHERE BETTER CHANCES ARE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...LOCKHART
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
308 AM MST WED JAN 20 2016
.UPDATE...
ISSUED AT 307 AM MST WED JAN 20 2016
LATEST OBSERVATIONS/TRENDS INDICATE THE FREEZING FOG WILL BE EAST
OF THE COLORADO BORDER. HAVE SHIFTED THE COVERAGE OF FOG IN THE
FORECAST FURTHER EAST AS A RESULT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 237 AM MST WED JAN 20 2016
LATEST SATELLITE IMAGERY AND UPPER AIR ANALYSIS SHOWS SEMI ZONAL
FLOW OVER THE CONUS. A LONG BAND OF CLOUD COVER WAS EVIDENT OVER
THE ROCKIES AHEAD OF A SHORT WAVE TROUGH. LOW CLOUDS AND FOG WERE
MOVING NORTH OVER THE TRI-STATE AREA DUE TO INCREASED MOISTURE
ADVECTION FROM THE LOW LEVEL JET. LATEST OBSERVATIONS SHOW
VISIBILITIES UNDER A MILE BEING REPORTED SPORADICALLY UNDER THE LOW
CLOUDS.
TODAY EXPECT THE FOG AND LOW CLOUDS TO PROGRESS NORTHWARD ACROSS THE
ENTIRE AREA. THE WORST OF THE FOG WILL BE EAST OF THE COLORADO
BORDER...WITH THE LOWEST VISIBILITIES OCCURRING DURING THE FIRST
HALF OF THE MORNING. DUE TO CLOUDS REMAINING OVER THE AREA THROUGH
THE DAY...THE FOG MAY LINGER A BIT LONGER THAN NORMAL. LOCATIONS
WHERE VISIBILITIES ARE UNDER A MILE WILL LIKELY HAVE A THIN GLAZE OF
ICE DEVELOP ON EXPOSED SURFACES.
OTHERWISE AN UPPER LEVEL SHORT WAVE TROUGH WILL MOVE ACROSS THE AREA
TODAY. DUE TO THE WEAK LIFT AND MOST OF THE MOISTURE REMAINING
ABOVE 700MB...DO NOT ANTICIPATE ANY PRECIPITATION OCCURRING DURING
THE DAY.
TONIGHT A SECOND UPPER LEVEL SHORT WAVE TROUGH WILL MOVE OVER THE
AREA...CLOSING OFF FROM THE REST OF THE UPPER LEVEL FLOW OVER THE
NORTHEAST HALF OF THE AREA. THE MAJORITY OF THE VORTICITY WILL BE
WITH THE FIRST SHORT WAVE TROUGH...AHEAD OF THIS SECOND ONE. THIS
WILL LEAD TO LITTLE OR NO MID/UPPER LEVEL LIFT WITH THIS TROUGH AS
IT MOVES THROUGH. HOWEVER WEAK LOW LEVEL FRONTOGENESIS...IN THE
FIRST KILOMETER ABOVE GROUND WHERE THE ENVIRONMENT WILL BE
SATURATED...WILL LEAD TO SOME SNOW DEVELOPING AFTER MIDNIGHT OVER
THE NORTHEAST QUADRANT OF THE AREA. THIS AREA OF SNOWFALL WILL
GRADUALLY MOVE EAST WITH THE PARENT TROUGH.
MEANWHILE ANOTHER AREA OF LIFT/LOW LEVEL FRONTOGENESIS WILL DEVELOP
OVER THE NORTHWEST QUADRANT OF THE AREA BEHIND THE CLOSED LOW. THE
FRONTOGENESIS IN THIS PART OF THE AREA IS STRONGER THAN TO THE EAST
AND THE WEAK LIFT WITH IT IS DEEPER. IN ADDITION THE HIGH-RESOLUTION
MODELS ARE INDICATING A BETTER SHOT OF SNOW DEVELOPING THERE THAN
OVER THE EAST. WITH THIS IN MIND WILL HAVE THE BETTER CHANCES FOR
SNOWFALL OVER THE NORTHWEST PART OF THE AREA.
A COLD FRONT WILL ALSO MOVE THROUGH THE AREA WITH THE SECOND UPPER
LEVEL TROUGH AND AHEAD OF THE SNOWFALL. BEHIND THE FRONT WINDS WILL
INCREASE.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 237 AM MST WED JAN 20 2016
THURSDAY MORNING THE LIGHT SNOW WILL CONTINUE OVER BOTH THE
NORTHEAST AND NORTHWEST QUADRANTS OF THE AREA...GRADUALLY MOVING
EAST THROUGH THE MORNING. BY THE EARLY AFTERNOON THE WEAK LIFT WILL
END CAUSING ANY LINGERING SNOW TO END AS WELL. TOTAL SNOWFALL FOR
TONIGHT AND THURSDAY WILL BE LESS THAN AN INCH.
IN ADDITION TO THE SNOW NORTH WINDS WILL BE WINDY...WITH GUSTS UP TO
40 MPH OVER THE WEST HALF OF THE AREA. TO THE EAST THE WINDS WILL
NOT BE AS STRONG DUE TO A WEAKER LOW LEVEL JET OVERHEAD. THE WINDS
WILL LEAD TO BLOWING SNOW WHICH MAY REDUCE VISIBILITIES SOME.
THE BLOWING SNOW WILL END DURING THE AFTERNOON. BEHIND THE SNOW
CLOUDS WILL BEGIN TO CLEAR AS DRIER AIR MOVES INTO THE AREA FROM THE
WEST.
THURSDAY NIGHT WINDS WILL QUICKLY DECLINE DURING THE EVENING.
MEANWHILE CLOUDS WILL CONTINUE TO CLEAR FROM WEST TO EAST. WITH A
COOLER AIR MASS IN PLACE TEMPERATURES WILL FALL INTO THE TEENS.
THIS WILL LEAD TO WIND CHILLS IN THE SINGLE DIGITS BY SUNRISE.
FRIDAY/FRIDAY NIGHT WILL BE UNEVENTFUL AS DRIER AIR REMAINS IN PLACE
AS A LONG WAVE RIDGE MOVES OVERHEAD. TEMPERATURES WILL WARM TO NEAR
NORMAL.
SATURDAY...UPPER RIDGE AXIS MOVES OVER THE AREA DURING THE DAY
AHEAD OF A BROAD UPPER TROUGH WHOSE AXIS MOVES ASHORE BY SUNSET.
FLOW ALOFT SHIFTS TO THE SOUTHWEST AS A RESULT AND CONTINUES THROUGH
THE NIGHT. SOME HIGH CLOUDINESS EXPECTED DURING THE DAY...DECREASING
SOME OVERNIGHT. NO PRECIPITATION EXPECTED. AFTERNOON
TEMPERATURES PEAK IN THE MID 40S TO MID 50S (EAST TO WEST) WITH
OVERNIGHT LOWS IN THE LOW TO MID 20S.
SUNDAY...LONG RANGE MODELS IN BETTER AGREEMENT (COMPARED TO 24 HOURS
AGO) BRINGING BASE OF UPPER TROUGH INTO THE AREA BY DAYS END THEN
INTO THE MIDWEST OVERNIGHT. COLD FRONT MOVES THROUGH AS WELL WITH
NORTHERLY SURFACE WINDS. MODELS DISAGREE ON EXTENT OF COLD AIR WITH
THE ECMWF SEVERAL DEGREES COLDER AT 850MB WHEN COMPARED TO THE GFS.
CURRENT FORECAST HIGHS IN THE MID TO UPPER 40S WOULD FAVOR THE GFS
SOLUTION. NORTH WINDS CONTINUE OVERNIGHT WITH LOW TEMPERATURES IN
THE LOW TO MID 20S. AS FAR AS PRECIPITATION CHANCES...WILL KEEP SOME
SLIGHT CHANCE POPS GOING FOR THE DAY...INCREASING JUST A BIT
OVERNIGHT.
MONDAY...SUNDAYS WEATHER SYSTEM MOVES AWAY FROM THE AREA BUT THE
FORECAST AREA IS CAUGHT IN NORTHWEST FLOW ALOFT ALLOWING MORE
WEATHER SYSTEMS TO MOVE INTO THE AREA. CURRENTLY HAVE A DRY FORECAST
BUT WOULDNT BE SURPRISED IF WE HAVE SOME SPOTTY LIGHT PRECIP. MAY
SEE BREEZY NORTHWEST WINDS DURING THE DAY AS WELL. AFTERNOON
TEMPERATURES A BIT COOLER AND JUST BELOW NORMAL WITH UPPER 30S TO
LOW 40S. LOOKING AT SOME DECREASING CLOUDINESS OVERNIGHT WITH LOW
TEMPERATURES IN THE MID TEENS TO LOW 20S.
TUESDAY...SUNSHINE RETURNS TO THE AREA AS HIGH AMPLITUDE RIDGE AXIS
MOVES SLOWLY TOWARD THE AREA DURING THE DAY. RIDGE AXIS BREAKS DOWN
PRETTY QUICKLY OVERNIGHT WITH SOME INCREASE IN HIGH CLOUDS EXPECTED.
AFTERNOON TEMPERATURES WARM BACK INTO THE LOW TO MID 40S WITH
OVERNIGHT LOWS AGAIN IN THE MID TEENS TO LOW 20S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1023 PM MST TUE JAN 19 2016
VFR CONDITIONS WILL CONTINUE BRIEFLY AT KGLD AND KMCK AND THEN
DETERIORATE TO MVFR AND LOWER, ESPECIALLY AT KMCK. THE HRRR KEEPS
KGLD AT VFR WHILE THE NAM BRINGS SOME LOWER CONDITIONS. CONDITIONS
SHOULD IMPROVE RATHER EARLY WEDNESDAY MORNING EVEN AT KMCK. SOME
MID LEVEL CLOUDS REMAIN IN RESPONSE TO THE NEXT SHORTWAVE THAT
COMES THROUGH WEDNESDAY AFTERNOON. CLOUDS DECREASE BRIEFLY
WEDNESDAY EVENING IN A BRIEF LULL BEFORE THE NEXT SHORTWAVE
AFFECTS THE AREA.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...JTL
LONG TERM...99/JTL
AVIATION...FS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
239 AM MST WED JAN 20 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 237 AM MST WED JAN 20 2016
LATEST SATELLITE IMAGERY AND UPPER AIR ANALYSIS SHOWS SEMI ZONAL
FLOW OVER THE CONUS. A LONG BAND OF CLOUD COVER WAS EVIDENT OVER
THE ROCKIES AHEAD OF A SHORT WAVE TROUGH. LOW CLOUDS AND FOG WERE
MOVING NORTH OVER THE TRI-STATE AREA DUE TO INCREASED MOISTURE
ADVECTION FROM THE LOW LEVEL JET. LATEST OBSERVATIONS SHOW
VISIBILITIES UNDER A MILE BEING REPORTED SPORADICALLY UNDER THE LOW
CLOUDS.
TODAY EXPECT THE FOG AND LOW CLOUDS TO PROGRESS NORTHWARD ACROSS THE
ENTIRE AREA. THE WORST OF THE FOG WILL BE EAST OF THE COLORADO
BORDER...WITH THE LOWEST VISIBILITIES OCCURRING DURING THE FIRST
HALF OF THE MORNING. DUE TO CLOUDS REMAINING OVER THE AREA THROUGH
THE DAY...THE FOG MAY LINGER A BIT LONGER THAN NORMAL. LOCATIONS
WHERE VISIBILITIES ARE UNDER A MILE WILL LIKELY HAVE A THIN GLAZE OF
ICE DEVELOP ON EXPOSED SURFACES.
OTHERWISE AN UPPER LEVEL SHORT WAVE TROUGH WILL MOVE ACROSS THE AREA
TODAY. DUE TO THE WEAK LIFT AND MOST OF THE MOISTURE REMAINING
ABOVE 700MB...DO NOT ANTICIPATE ANY PRECIPITATION OCCURRING DURING
THE DAY.
TONIGHT A SECOND UPPER LEVEL SHORT WAVE TROUGH WILL MOVE OVER THE
AREA...CLOSING OFF FROM THE REST OF THE UPPER LEVEL FLOW OVER THE
NORTHEAST HALF OF THE AREA. THE MAJORITY OF THE VORTICITY WILL BE
WITH THE FIRST SHORT WAVE TROUGH...AHEAD OF THIS SECOND ONE. THIS
WILL LEAD TO LITTLE OR NO MID/UPPER LEVEL LIFT WITH THIS TROUGH AS
IT MOVES THROUGH. HOWEVER WEAK LOW LEVEL FRONTOGENESIS...IN THE
FIRST KILOMETER ABOVE GROUND WHERE THE ENVIRONMENT WILL BE
SATURATED...WILL LEAD TO SOME SNOW DEVELOPING AFTER MIDNIGHT OVER
THE NORTHEAST QUADRANT OF THE AREA. THIS AREA OF SNOWFALL WILL
GRADUALLY MOVE EAST WITH THE PARENT TROUGH.
MEANWHILE ANOTHER AREA OF LIFT/LOW LEVEL FRONTOGENESIS WILL DEVELOP
OVER THE NORTHWEST QUADRANT OF THE AREA BEHIND THE CLOSED LOW. THE
FRONTOGENESIS IN THIS PART OF THE AREA IS STRONGER THAN TO THE EAST
AND THE WEAK LIFT WITH IT IS DEEPER. IN ADDITION THE HIGH-RESOLUTION
MODELS ARE INDICATING A BETTER SHOT OF SNOW DEVELOPING THERE THAN
OVER THE EAST. WITH THIS IN MIND WILL HAVE THE BETTER CHANCES FOR
SNOWFALL OVER THE NORTHWEST PART OF THE AREA.
A COLD FRONT WILL ALSO MOVE THROUGH THE AREA WITH THE SECOND UPPER
LEVEL TROUGH AND AHEAD OF THE SNOWFALL. BEHIND THE FRONT WINDS WILL
INCREASE.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 237 AM MST WED JAN 20 2016
THURSDAY MORNING THE LIGHT SNOW WILL CONTINUE OVER BOTH THE
NORTHEAST AND NORTHWEST QUADRANTS OF THE AREA...GRADUALLY MOVING
EAST THROUGH THE MORNING. BY THE EARLY AFTERNOON THE WEAK LIFT WILL
END CAUSING ANY LINGERING SNOW TO END AS WELL. TOTAL SNOWFALL FOR
TONIGHT AND THURSDAY WILL BE LESS THAN AN INCH.
IN ADDITION TO THE SNOW NORTH WINDS WILL BE WINDY...WITH GUSTS UP TO
40 MPH OVER THE WEST HALF OF THE AREA. TO THE EAST THE WINDS WILL
NOT BE AS STRONG DUE TO A WEAKER LOW LEVEL JET OVERHEAD. THE WINDS
WILL LEAD TO BLOWING SNOW WHICH MAY REDUCE VISIBILITIES SOME.
THE BLOWING SNOW WILL END DURING THE AFTERNOON. BEHIND THE SNOW
CLOUDS WILL BEGIN TO CLEAR AS DRIER AIR MOVES INTO THE AREA FROM THE
WEST.
THURSDAY NIGHT WINDS WILL QUICKLY DECLINE DURING THE EVENING.
MEANWHILE CLOUDS WILL CONTINUE TO CLEAR FROM WEST TO EAST. WITH A
COOLER AIR MASS IN PLACE TEMPERATURES WILL FALL INTO THE TEENS.
THIS WILL LEAD TO WIND CHILLS IN THE SINGLE DIGITS BY SUNRISE.
FRIDAY/FRIDAY NIGHT WILL BE UNEVENTFUL AS DRIER AIR REMAINS IN PLACE
AS A LONG WAVE RIDGE MOVES OVERHEAD. TEMPERATURES WILL WARM TO NEAR
NORMAL.
SATURDAY...UPPER RIDGE AXIS MOVES OVER THE AREA DURING THE DAY
AHEAD OF A BROAD UPPER TROUGH WHOSE AXIS MOVES ASHORE BY SUNSET.
FLOW ALOFT SHIFTS TO THE SOUTHWEST AS A RESULT AND CONTINUES THROUGH
THE NIGHT. SOME HIGH CLOUDINESS EXPECTED DURING THE DAY...DECREASING
SOME OVERNIGHT. NO PRECIPITATION EXPECTED. AFTERNOON
TEMPERATURES PEAK IN THE MID 40S TO MID 50S (EAST TO WEST) WITH
OVERNIGHT LOWS IN THE LOW TO MID 20S.
SUNDAY...LONG RANGE MODELS IN BETTER AGREEMENT (COMPARED TO 24 HOURS
AGO) BRINGING BASE OF UPPER TROUGH INTO THE AREA BY DAYS END THEN
INTO THE MIDWEST OVERNIGHT. COLD FRONT MOVES THROUGH AS WELL WITH
NORTHERLY SURFACE WINDS. MODELS DISAGREE ON EXTENT OF COLD AIR WITH
THE ECMWF SEVERAL DEGREES COLDER AT 850MB WHEN COMPARED TO THE GFS.
CURRENT FORECAST HIGHS IN THE MID TO UPPER 40S WOULD FAVOR THE GFS
SOLUTION. NORTH WINDS CONTINUE OVERNIGHT WITH LOW TEMPERATURES IN
THE LOW TO MID 20S. AS FAR AS PRECIPITATION CHANCES...WILL KEEP SOME
SLIGHT CHANCE POPS GOING FOR THE DAY...INCREASING JUST A BIT
OVERNIGHT.
MONDAY...SUNDAYS WEATHER SYSTEM MOVES AWAY FROM THE AREA BUT THE
FORECAST AREA IS CAUGHT IN NORTHWEST FLOW ALOFT ALLOWING MORE
WEATHER SYSTEMS TO MOVE INTO THE AREA. CURRENTLY HAVE A DRY FORECAST
BUT WOULDNT BE SURPRISED IF WE HAVE SOME SPOTTY LIGHT PRECIP. MAY
SEE BREEZY NORTHWEST WINDS DURING THE DAY AS WELL. AFTERNOON
TEMPERATURES A BIT COOLER AND JUST BELOW NORMAL WITH UPPER 30S TO
LOW 40S. LOOKING AT SOME DECREASING CLOUDINESS OVERNIGHT WITH LOW
TEMPERATURES IN THE MID TEENS TO LOW 20S.
TUESDAY...SUNSHINE RETURNS TO THE AREA AS HIGH AMPLITUDE RIDGE AXIS
MOVES SLOWLY TOWARD THE AREA DURING THE DAY. RIDGE AXIS BREAKS DOWN
PRETTY QUICKLY OVERNIGHT WITH SOME INCREASE IN HIGH CLOUDS EXPECTED.
AFTERNOON TEMPERATURES WARM BACK INTO THE LOW TO MID 40S WITH
OVERNIGHT LOWS AGAIN IN THE MID TEENS TO LOW 20S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1023 PM MST TUE JAN 19 2016
VFR CONDITIONS WILL CONTINUE BRIEFLY AT KGLD AND KMCK AND THEN
DETERIORATE TO MVFR AND LOWER, ESPECIALLY AT KMCK. THE HRRR KEEPS
KGLD AT VFR WHILE THE NAM BRINGS SOME LOWER CONDITIONS. CONDITIONS
SHOULD IMPROVE RATHER EARLY WEDNESDAY MORNING EVEN AT KMCK. SOME
MID LEVEL CLOUDS REMAIN IN RESPONSE TO THE NEXT SHORTWAVE THAT
COMES THROUGH WEDNESDAY AFTERNOON. CLOUDS DECREASE BRIEFLY
WEDNESDAY EVENING IN A BRIEF LULL BEFORE THE NEXT SHORTWAVE
AFFECTS THE AREA.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...JTL
LONG TERM...99/JTL
AVIATION...FS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1038 PM MST TUE JAN 19 2016
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 210 PM MST TUE JAN 19 2016
EARLY AFTERNOON WV IMAGERY AND RAP ANALYSIS SHOWS RIDGING ACROSS THE
ROCKIES WITH A SHORTWAVE TROUGH TRANSITIONING OUT OF THE PLAINS
TOWARDS THE CENTRAL MISSISSIPPI RIVER VALLEY. ANOTHER SHORTWAVE
TROUGH UPSTREAM OF THE RIDGE IS MOVING INTO THE PACIFIC NORTHWEST
WITH A MUCH STRONGER WEST-EAST ORIENTATED UPPER LEVEL JET OVER
NORTHERN CALIFORNIA. AT THE SURFACE LEE TROUGH HAS DEVELOPED OVER
EAST CENTRAL COLORADO (NEAR FRONT RANGE) AND WARM FRONT IS IN THE
PROCESS OF LIFTING OVER THE NORTHEAST PART OF OUR CWA (FROM KMCK TO
KHLC). PERSISTENT STRATUS IS STILL IN PLACE IN OUR EASTERN CWA WITH
CLOUD SHIELD BREAKING UP IN THE WEST.
THIS EVENING-WEDNESDAY MORNING...MAIN CONCERN WILL FOCUS ON POSSIBLE
DENSE FOG DEVELOPMENT THIS EVENING/OVERNIGHT. MODELS SUPPORT LEE
TROUGH SHIFTING EASTWARD WITH SOUTHERLY FLOW QUICKLY DEVELOPING
AFTER SUNSET. THIS SHOULD HELP ADVECT GOOD BL MOISTURE BACK INTO OUR
CWA AND STRATUS IN THE EAST COULD THEN EXPAND WESTWARD. EARLIER
HRRR/RAP SUPPORTED FOG REDEVELOPING AFTER 00Z THIS EVENING NEAR THE
CO/KS BORDER AND SPREADING EASTWARD. LATEST SREF/NAM/RAP/HRRR NOW
SHOWING STRONGER SIGNAL AFTER MIDNIGHT TONIGHT THROUGH EARLY
WEDNESDAY MORNING WITH MAIN FOG AXIS SHIFTED FURTHER EAST (TOWARD
BACK EDGE OF CURRENT STRATUS DECK). I KEPT FOG COVERAGE/TIMING
SIMILAR TO EARLY GUIDANCE COVER POSSIBILITY...HOWEVER CONFIDENCE AT
THIS POINT IS SIGNIFICANTLY LOWER ON WHERE OR IF DENSE FOG MAY
DEVELOP OVER OUR CWA. (FOG MAY BE A GOOD BET BUT DENSE FOG MAY BE
PATCHY).
WEDNESDAY...TWO SHORTWAVES ARE EXPECTED TO MOVE ACROSS THE ROCKIES
AND OVER OUR CWA WITH THE FIRST (WEAKER) SHORTWAVE MOVING OVER OUR
CWA MIDDAY WEDNESDAY. AS WAS INDICATED IN EARLIER GUIDANCE ON MID
SHIFT THERE IS A SIGNIFICANT DRY LAYER FROM ABOVE THE BL TO 600-
700MB. DESPITE FORCING THIS LOWERS CONFIDENCE IN ANY MEASURABLE
PRECIP DURING THE DAY WEDNESDAY. BY LATE WEDNESDAY AFTERNOON THE
SECOND (STRONGER) SHORTWAVE TROUGH DIGS SOUTHEAST AND OVERTAKES THE
FIRST TROUGH WITH A STRONGER UPPER LEVEL JET BEGINNING TO DEVELOP.
BY LATE AFTERNOON THERE IS A WEAK PRECIP SIGNAL IN OUR FAR EASTERN
CWA AND GUIDANCE THERE DOES SHOW SOME MOISTENING OF THE MOISTURE
PROFILE. I KEPT SMALL AREA OF SLIGHT CHANCE POPS IN GRAHAM/NORTON
COUNTIES TO MATCH THIS...BUT CONFIDENCE IS STILL NOT HIGH THAT
THINGS WOULD START THIS EARLY.
OTHER CONCERN FOR WEDNESDAY WILL BE HIGHS. POTENTIAL EXISTS AGAIN
FOR LINGERING STRATUS...HOWEVER WITH TROUGHS MOVING THROUGH THE
REGION THICK/OPAQUE MID-HIGH CLOUD COVER COULD ALSO LIMIT DIURNAL
HEATING. I LOWERED HIGHS IN THE EAST FROM PREVIOUS FORECAST DUE TO
POTENTIAL IMPACTS OF CLOUD COVER. TOUGH CALL AND IF WE WERE TO
CLEAR OUT (MORE LIKELY IN THE WEST) WE COULD SEE HIGHS IN THE
UPPER 40S.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 248 PM MST TUE JAN 19 2016
FORECAST ISSUES WILL BE CHANCE OF PRECIPITATION AND PHASE OF
PRECIPITATION WEDNESDAY NIGHT INTO THURSDAY. SATELLITE SHOWING A
SOMEWHAT AMPLIFIED BUT STILL PROGRESSIVE AND ACTIVE FLOW PATTERN
FROM THE PACIFIC INTO THE WESTERN ATLANTIC. LARGE AND COMPLICATED
UPPER TROUGH IS OVER THE NORTHEAST PACIFIC.
AT JET LEVEL...THE MODELS WERE HAVING A LITTLE TROUBLE WITH THE JET
ALONG THE WEST COAST. AT MID LEVELS...MODELS WERE ALL ABOUT THE SAME
BUT THEY WERE ALSO A LITTLE FAR EAST/FAST WITH THE UPPER TROUGH NOW
COMING ON THE COAST. THE NAM/ECMWF WAS DOING THE BEST ON THE SURFACE
WIND AND PRESSURE FIELD. THE GFS AND CANADIAN WERE DOING THE BEST ON
THE LOW LEVEL THERMAL FIELD WITH MOST MODELS NOT BEING COLD ENOUGH.
WEDNESDAY NIGHT...DEVELOPING PRECIPITATION EVENT IS IN ITS BEGINNING
STAGES. MODELS DIFFERENT ON SPEED...POSITION AND AMPLITUDE OF MID
LEVEL CIRCULATION THAT APPEARS TO BE DEVELOPING ON TOP OF US OR JUST
TO THE EAST OF US. TODAYS MODEL RUNS VERY DIFFERENT THAN 24 HOURS
AGO. BY THE BEGINNING OF THIS PERIOD...MODELS STILL HAVE STRONG
NORTH TO SOUTH JET ON THE WEST SIDE OF THIS UPPER SYSTEM.
THIS COMBINED WITH THE PROBLEM OF THE MODELS INITIALLY HAVING THIS
SYSTEM TOO FAR EAST THIS MORNING...LEADS ME TO BELIEVE THAT WHATEVER
ENDS UP BEING THE SLOWER AND EVEN FURTHER SOUTH SOLUTION WILL END UP
BEING MORE RIGHT. EVEN NOW AM THINKING CURRENT MODEL RUN STILL MAY
BE TOO FAST/FAR NORTH. TROUGH IS ELONGATED AND COMPROMISED OF A
NORTHERN AND SOUTHERN CIRCULATIONS WITHIN THIS TROUGH. PAST
EXPERIENCE HAS SHOWN THIS SETUP IS NOT GREAT FOR A LOT OF
PRECIPITATION.
SAYING ALL THAT...THE FAR EASTERN PORTION OF THE AREA WILL HAVE THE
BEST CHANCE WITH BEST CHANCE OVERALL AT THIS TIME BEING TO THE EAST
OF OUR AREA. THE GRADIENT OF THE CHANCE OF PRECIPITATION WILL BE
REALLY SHARP. PER THE REASONING ABOVE...AM THINKING THAT THE BEST
CHANCE OF PRECIPITATION WILL BE AFTER MIDNIGHT AND THAT IS SUPPORTED
BY THE SREF PROBABILITIES. BEST CHANCE WILL BE VERY LATE IN THE
NIGHT.
THERE IS NOT A LOT OF COLD AIR WITH THIS SYSTEM...AND DEPENDING ON
WHICH MODEL YOU CHOOSE THE CHANGE OVER MAY NOT OCCUR UNTIL LATE
EVENING/AROUND MIDNIGHT WITH THE EASTERN AREAS CHANGING OVER FIRST.
THE PHASE IS REALLY WHERE THERE ARE BIG DIFFERENCES. SOME MODELS
KEEPING TOTALLY DRY OR HAVE JUST ENOUGH MOISTURE IN THE LOW LEVELS
FOR DRIZZLE/FREEZING DRIZZLE. SO A LOT OF UNCERTAINTY WITH THIS
SYSTEM.
THURSDAY/THURSDAY NIGHT...WITH THE PROXIMITY OF THE SYSTEM AND
EXPECTED SLOWNESS...ALONG WITH MID AND UPPER LEVEL LIFT
EXPECTED...EXPECT THE BEST CHANCE OF PRECIPITATION WILL BE IN THE
MORNING AND THEN RAPIDLY DECREASE AND END. IF CURRENT FORECAST PANS
OUT...THE FAR EASTERN PORTION OF THE AREA GETS 1 TO 2 INCHES.
GRADIENT AND DOWNWARD MOTION BEHIND THE SYSTEM WILL CREATE BREEZY TO
WINDY CONDITIONS. THE STRONGEST WINDS ARE AFTER THE SNOW ENDS...AND
WITH TEMPERATURES JUST ABOVE FREEZING...DO NOT EXPECT ANY BLOWING
SNOW PROBLEMS AT THIS TIME. CURRENT HIGH TEMPERATURE FORECAST LOOKS
TO BE IN GOOD SHAPE AND MADE ONLY MINOR ADJUSTMENTS. HOWEVER...IF
MORE SNOW THAN EXPECT IT WILL BE COLDER. LIGHT WINDS AND LITTLE
CLOUD COVER WILL ALLOW OVERNIGHT TEMPERATURES TO DROP A DECENT
AMOUNT.
FRIDAY...STRONG MID/UPPER LEVEL RIDGE BUILDS IN OVER THE AREA.
SURFACE WILL MOVE THROUGH AND TO THE EAST OF THE AREA DURING THE
DAY. SO DO EXPECT RECYCLED COOL AIR. THE EASTERN LOCATIONS WILL BE
THE COLDEST AND OVERALL REDUCED THE HIGH TEMPERATURES A LITTLE.
FRIDAY NIGHT THROUGH TUESDAY...MID AND UPPER RIDGE WILL BE IN PLACE
FROM FRIDAY NIGHT INTO SATURDAY NIGHT SO EXPECT MODERATING
TEMPERATURES AND DRY CONDITIONS. THE INIT WAS REASONABLE WITH THIS
AND MADE NO CHANGES.
A STRONG SHORTWAVE TROUGH...NOT UNLIKE THE ONE THAT WENT THROUGH
THIS MORNING AND SIMILAR ALSO THE SYSTEM EXPECTED WEDNESDAY NIGHT
AND THURSDAY...WILL MOVE THROUGH SUNDAY AND SUNDAY NIGHT. THE INIT
PRODUCED SLIGHT CHANCE POPS DURING THIS PERIOD AND SEEMS REASONABLE.
POSSIBLE THAT THESE CHANCES WILL INCREASE. AFTER THAT RIDGING WILL
MOVE INTO THE AREA AND BRING DRY CONDITIONS AND MODERATING
TEMPERATURES ONCE AGAIN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1023 PM MST TUE JAN 19 2016
VFR CONDITIONS WILL CONTINUE BRIEFLY AT KGLD AND KMCK AND THEN
DETERIORATE TO MVFR AND LOWER, ESPECIALLY AT KMCK. THE HRRR KEEPS
KGLD AT VFR WHILE THE NAM BRINGS SOME LOWER CONDITIONS. CONDITIONS
SHOULD IMPROVE RATHER EARLY WEDNESDAY MORNING EVEN AT KMCK. SOME
MID LEVEL CLOUDS REMAIN IN RESPONSE TO THE NEXT SHORTWAVE THAT
COMES THROUGH WEDNESDAY AFTERNOON. CLOUDS DECREASE BRIEFLY
WEDNESDAY EVENING IN A BRIEF LULL BEFORE THE NEXT SHORTWAVE
AFFECTS THE AREA.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...BULLER
AVIATION...FS
AREA FORECAST DISCUSSION
NWS JACKSON KY
222 AM EST WED JAN 20 2016
.UPDATE...
ISSUED AT 222 AM EST WED JAN 20 2016
SNOW JUST NOW BEGINNING ITS PUSH INTO CENTRAL KENTUCKY...WITH
PERHAPS SOME FLURRIES MAKING INTO THE CUMBERLAND PLATEAU. HAVE
SLOWED DOWN THE ONSET OF PRECIPITATION A BIT FOR A FEW MORE HOURS.
LOOKS LIKE AFTER 4 AM...WE SHOULD START TO SEE BETTER COVERAGE. A
LITTLE CONCERNED THE DRY AIR AND SOUTHEAST DOWNSLOPING FLOW
CURRENTLY IN PLACE MAY LIMIT THE INITIAL PUSH OF PRECIPITATION
INTO EASTERN KENTUCKY. THIS COMBINED WITH WHAT MODELS ARE
PORTRAYING AS SNOW RATIOS POSSIBLY UNDER 10 IN THE SOUTH MAY LIMIT
OVERALL SNOWFALL POTENTIAL. HAVE CHOPPED DOWN SNOWFALL TOTALS A
BIT TO MORE IN THE 1 TO 2 INCH RANGE GIVEN THE SOMEWHAT
UNFAVORABLE CONDITIONS AT THE ONSET. THE OTHER THING TO CONSIDER
IS THE BEST OMEGA STILL DOESN`T COINCIDE WITH THE DENDRITIC GROWTH
ZONE...WHICH IS PROBABLY WHY THE SNOW RATIOS ARE COMING IN LOWER.
REGARDLESS...WE SHOULD STILL BE CLOSE TO ADVISORY CRITERIA ON THE
SNOWFALL...BUT IT WILL BE A CHALLENGE TO REACH THE 4 INCHES FOR A
WARNING IN WAYNE COUNTY. REGARDLESS...BEING WE WILL GET CLOSE...AND
TO AVOID CONFUSION...WILL LEAVE HEADLINES UNCHANGED.
UPDATE ISSUED AT 1040 PM EST TUE JAN 19 2016
THE LEADING EDGE OF PRECIPITATION FROM A SYSTEM TO AFFECT THE
REGION LATER TONIGHT AND INTO WEDNESDAY NIGHT HAS MOVED INTO
SOUTHERN IL AND FAR WESTERN KY. THIS PRECIPITATION SHOULD CONTINUE
TO SPREAD EAST OVERNIGHT AND INTO WEDNESDAY MORNING.
THE 18Z NAM AND NOW THE 0Z NAM HAVE POINTED TOWARD HIGHER QPF IN
THE FAR SW COMPARED TO THE PREVIOUS FORECAST. THE 0Z GFS ALSO HAS
QPF THAT SHOULD BE ENTIRELY OR ALMOST ENTIRELY SNOW OF AROUND 0.40
INCHES IN WAYNE COUNTY. WITH SNOW RATIOS EXPECTED TO BE 10 TO 11
TO 1 THAT WOULD PROBABLY PUSH WAYNE COUNTY TO AT OR SLIGHTLY ABOVE
THE 12 HOUR WINTER STORM WARNING CRITERIA OF 4 INCHES. WITH THIS
IN MIND...WAYNE COUNTY HAS BEEN UPGRADED TO A WINTER STORM
WARNING FOR 3 TO 5 INCHES OF SNOW. NEIGHBORING COUNTIES TO WANE
SHOULD PICK UP AMOUNTS IN THE 2 TO 4 INCH RANGE...WITH AMOUNTS
TAPERING OFF FROM THERE TO THE NORTH AND EAST DUE TO DRIER AIR IN
PLACE. SOME OF THE RECENT RAP AND HRRR RUNS SUPPORT THE 0Z NAM AND
0Z GFS TO AN EXTENT ALTHOUGH THE 2Z RAP HAS HIGHER QPF FURTHER
NORTH INTO THE PULASKI TO LAUREL COUNTY CORRIDOR. THE MOST RECENT
HRRR IS SLIGHTLY LIGHTER WITH AM SNOW IN THE SW COUNTIES COMPARED
TO A COUPLE OF EARLIER RUNS...SO OVERALL SOME UNCERTAINTY REMAINS
EVEN WITH THIS SYSTEM. HOWEVER...THERE SEEMS TO BE AN UPWARD TREND
IN QPF AND SNOWFALL FOR THE FAR SW THUS THE WAYNE COUNTY UPGRADE.
AN UPDATED WSW AND HWO HAVE BEEN ISSUED.
AS FOR THE LATE WEEK SYSTEM...THE DISTURBANCES THAT SHOULD INTERACT
OR PHASE TOGETHER FOR THE EASTERN CONUS TROUGH AND LOW PRESSURE
SYSTEM ARE NOW ONSHORE OF THE WESTERN U.S. OR MOVING ONSHORE AT
THIS TIME. AS UPPER AIR NETWORKS BEGIN TO CAPTURE THE STRENGTH OF
THESE SYSTEMS...MODEL RUNS FROM 0Z THIS MORNING AND INTO WEDNESDAY
SHOULD BEGIN TO CLOSE IN WITH MORE OF A CONSENSUS. THIS SYSTEM
WILL CONTINUE TO BE MONITORED AND IS ALSO BEING HIGHLIGHTED IN
WEATHER STORIES AND HWO.
UPDATE ISSUED AT 810 PM EST TUE JAN 19 2016
OTHER THAN FINE TUNING THE HOURLY TEMPERATURE FORECAST FOR THE
NEXT FEW HOURS...NO CHANGES ARE NEEDED AT THIS TIME. AS THE 0Z
MODEL RUNS COME IN AS WELL AS THE 21Z SREF AND HRRR AND RAP RUNS
WILL BE EVALUATED FOR WHETHER OR NOT QPF AND SNOW AMOUNTS MAY NEED
TO INCREASED ACROSS THE LAKE CUMBERLAND REGION.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 406 PM EST TUE JAN 19 2016
CURRENT CONDITIONS ACROSS THE AREA FEATURE CLOUD COVER ON THE
INCREASE IN WESTERN KENTUCKY ASSOCIATED WITH A DEVELOPING SYSTEM.
MEANWHILE...IN EASTERN KENTUCKY CLOUD COVER IS DISSIPATING AS
NORTHWEST UPSLOPE FLOW DECREASES AS THE CENTER OF THE ARCTIC HIGH
HAS MOVED OVER THE AREA. THUS HAVE CLEARED SKY COVER AND SHUT OFF
THE FLURRIES ACROSS THE AREA AS WELL. AFTER 00Z TONIGHT...SKIES
WILL CLOUD UP AGAIN AS THE NEXT SYSTEM MOVES THROUGH THE
BLUEGRASS. PRECIP WILL BEGIN TO MOVE INTO THE AREA AFTER 08Z.
MODEL TRENDS HAVE KEPT THIS FEATURE WITH A GOOD AMOUNT OF LIFT AND
MOISTURE. TRENDS HAVE ALSO TAKEN THE MOST AMOUNT OF MOISTURE TO
THE SOUTH INTO CENTRAL KY AND THEN INTO TN JUST CLIPPING WETS OF
THE I-75 CORRIDOR. THIS REGION WILL LIKELY SEE THE MOST AMOUNT OF
SNOW FROM THIS FEATURE. SURFACE TEMPS AS THIS FEATURE MOVES IN
WILL JUST BE RECOVERING FROM THE ARCTIC AIR MASS THAT HAS JUST
EVACUATED THE AREA. THUS PRECIP WILL BEGIN AS SNOW FOR THIS
SYSTEM. WARMEST TEMPS THOUGH WILL BE IN THE SOUTH WITH SOUTHERLY
FLOW SETTING UP AHEAD OF THE FRONT. THUS...SNOW RATIOS WILL BE
SLIGHTLY LOWER THAN THE NORTH AS THIS FEATURE MOVES INTO THE AREA.
SNOW WILL CONTINUE ACROSS EASTERN KENTUCKY THROUGH THE DAY AND
BECOME MODERATE TO EVEN HEAVY AT TIMES. HIGH RATIOS TO THE NORTH
WILL MAKE FOR SNOWFALL AMOUNTS IN THE 1 TO 2 INCH RANGE BUT MORE
MOISTURE IN THE SOUTH WILL MAKE FOR 2 TO 3+ AMOUNTS DESPITE THE
LOWER SNOW RATIOS.
THE OTHER CONCERN FOR SNOW AMOUNTS WITH THIS FEATURE WILL BE THE
PROGRESSIVE FLOW AS THIS SYSTEM MOVES THROUGH. AS THE SYSTEM LOSES
A BIT OF MOISTURE MOVING INTO THE AREA...THE DEPTH OF THE MOISTURE
LESSENS QUITE QUICKLY BY WEDNESDAY AFTERNOON AND INTO WEDNESDAY
NIGHT. DUE TO THIS MUCH OF THE SNOW WILL CHANGE OVER TO FREEZING
DRIZZLE HEADING INTO WEDNESDAY EVENING AND WEDNESDAY NIGHT. IN
FACT...A GLAZE OF ICE IS POSSIBLE IN SOME AREAS...ESPECIALLY IN
THE SOUTH...WHERE UP TO 0.05 HUNDREDTHS ARE POSSIBLE. THIS SET UP
MAY ALSO TAKE AWAY FROM SOME OF THE SNOWFALL POTENTIAL IN THE
SOUTH. THUS...WILL KEEP THE WINTER WEATHER ADVISORY OUT FOR THE
ENTIRE AREA FROM TOMORROW MORNING AND THROUGH THURSDAY NIGHT.
HEADING INTO WEDNESDAY NIGHT...THE SYSTEM EXITS THE AREA AS THE
LAST OF THE LOW LEVEL MOISTURE EXITS AS WELL. THIS WILL BRING AN
END TO THE FREEZING DRIZZLE THREAT BEFORE THE NEXT FEATURE BEGINS
TO IMPACT THE AREA MOVING IN FROM THE SOUTH. IN FACT...WE WILL
HAVE A BRIEF BREAK IN THE PRECIP BY THURSDAY MORNING.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 406 PM EST TUE JAN 19 2016
COMPLICATED FORECAST IN THE LONG TERM WITH LOTS OF ATTENTION ON A
POSSIBLE MAJOR WINTER STORM IN THE THURSDAY NIGHT THROUGH SATURDAY
TIME RANGE.
AS OUR MIDWEEK WINTER SYSTEM PASSES TO OUR EAST...TEMPERATURES
ALOFT WILL BE ON THE RISE AS A WARM FRONT AT THE SURFACE MOVES UP
THE GREAT VALLEY OF EAST TENNESSEE VALLEY. THIS WILL SEND
PRECIPITATION BACK NORTH INTO THE AREA LATE THURSDAY INTO THURSDAY
NIGHT. THERMAL PROFILE IS TRICKY BUT P-TYPE IS EXPECTED TO BE
MOSTLY RAIN ACROSS THE SOUTH BUT A MIX OF RAIN...SNOW AND FREEZING
RAIN ALONG AND NORTH OF THE HAL ROGERS PARKWAY THURSDAY
NIGHT...AND PROBABLY ALL SNOW OR A MIX OF FREEZING RAIN AND SNOW
FROM I-64 NORTH. FORECAST MODELS THEN DIVERGE INTO FRIDAY BUT THE
PRESENCE OF AN INVERTED TROUGH EXTENDING UP THE GREAT VALLEY OF
EAST TENNESSEE INTO THE CUMBERLAND VALLEY WOULD SUPPORT A SCENARIO
WHERE THE WARM NOSE ALOFT EDGES FURTHER NORTH CAUSING PRECIP TO
MIX WITH OR CHANGE TO RAIN PERHAPS AS FAR NORTH AS THE MOUNTAIN
PARKWAY AND POSSIBLY EVEN I-64. THE NORTHWARD EXTEND TO THE CHANGE
TO RAIN DEPENDS GREATLY ON THE STRENGTH AND TRACK OF THE SURFACE
LOW...WITH WHICH THERE IS JUST A LOT OF UNCERTAINTY DUE TO MODEL
DIFFERENCES SO TRIED TO PAINT WITH A BROAD BRUSH AS FAR AS THE
ACTUAL P-TYPE FORECAST GOES RIGHT NOW THROUGH THE DAY FRIDAY.
SO...WHILE THE ACTUAL WEATHER YOU WILL SEE REMAINS UNCERTAIN
THURSDAY NIGHT AND FRIDAY...PLAN TO BE IMPACTED BY THE WEATHER IN
SOME FORM OR FASHION IF YOU HAVE TRAVEL PLANS AND MONITOR
FORECASTS AS OUR CONFIDENCE IN THE DETAILS IMPROVES OVER THE NEXT
DAY OR SO.
MODELS ARE FAIRLY CONSISTENT THAT COLDER AIR WILL WRAP IN BEHIND
THE DEPARTING SURFACE LOW FRIDAY EVENING CHANGING ALL PRECIP TO
SNOW QUICKLY FROM NORTHWEST TO SOUTHEAST. THE SNOW WILL LIKELY
CONTINUE THROUGH AT LEAST SATURDAY MORNING...AND POSSIBLY EVEN
INTO SATURDAY NIGHT AS THE UPPER LOW IS SLOW TO PIVOT THROUGH. THE
POTENTIAL EXISTS FOR SEVERAL INCHES OF SNOW.
THE REMAINDER OF THE EXTENDED WILL FEATURE WARMING TEMPS...
ALTHOUGH POTENTIAL SNOW COVER WILL HAVE A YET TO BE DETERMINED
INFLUENCE THERE. ANOTHER SYSTEM IS PROGGED TO DEVELOP OVER THE
SOUTHERN PLAINS AND THEN MOVE NORTHEAST SPREADING ANOTHER CHANCE
FOR PRECIPITATION ACROSS THE AREA AS EARLY AS MONDAY. THIS SHOULD
BE RAIN AS IT APPEARS RIGHT NOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 222 AM EST WED JAN 20 2016
VFR WILL CONTINUE FOR THE NEXT 2 TO 4 HOURS. BY LATE TONIGHT...A
WEATHER DISTURBANCE WILL BRING SNOWFALL TO THE FAR SOUTHWEST BY
09Z...SPREADING ACROSS THE ENTIRE AREA BY 16Z. THIS WILL THEN
RESULT IN DETERIORATION INTO MVFR AND THEN IFR AND POSSIBLY NEAR
OR BELOW AIRPORT MINS AT TIMES FOR VIS IN THE FALLING SNOW AND AND
CIGS DURING SNOW AND AFTER IT DEPARTS AND TAPERS TO DRIZZLE OR
FREEZING DRIZZLE. WINDS WILL BE LIGHT TO NEAR CALM THROUGH THE
PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 7 AM THIS MORNING TO 7 AM EST
THURSDAY FOR KYZ052-060-088-104-106>110-112-113-115-117>120.
WINTER WEATHER ADVISORY UNTIL 7 AM EST THURSDAY FOR KYZ044-050-
051-058-059-068-069-079-080-084>087-111-114-116.
WINTER STORM WARNING UNTIL 7 AM EST THURSDAY FOR KYZ083.
&&
$$
UPDATE...KAS
SHORT TERM...SHALLENBERGER
LONG TERM...ABE
AVIATION...KAS
AREA FORECAST DISCUSSION
National Weather Service Paducah KY
1118 PM CST TUE JAN 19 2016
.UPDATE...
Issued at 642 PM CST TUE JAN 19 2016
Watching very closely the precipitation across SEMO, where light
freezing rain/drizzle has been reported and has caused very
dangerous travel conditions. Issued a SPS, and highlighted it more
strongly in the social media realm. May take a look at the WSW.
Thing is, as the upper system moves closer and precip increases,
precip loading, top down cooling will start to erode the "warm"
layer, or at least suppress it toward the MO/AR border, and
transition precip to mainly sleet and snow early this evening. So
for now, will handle this as a very short term event, and not
complicate the overall message. Will make some minor changes to
the grid forecast in this area. The RAP thermal depictions support
this approach.
CN
&&
.SHORT TERM...(This evening through Wednesday night)
Issued at 131 PM CST TUE JAN 19 2016
With 12z model suite painting low end 4 tenths qpf, and high end
6 tenths, and ratios low end 12 to 1, and high end 17 to 1, per
collab with WPC and adjacent WFO`s...have upgraded to warn all
areas for broad 3 to 5 inch expectation.
More specifically, some heavier snow could paint a swath of
locally higher amounts (depending upon the solution)... and
higher liquid to snow ratios in cold low to mid 20s air... could
potentially yield a 6+ inch swath. The main threat area for this
is roughly latitudinally along the Ohio river thru the heart of
the FA and southward toward the AR/TN borders.
On the flip side, if more scant amounts of qpf across our north
occur (visa vi the GFS), and using a less gracious LSR, we could
see lesser 2 to 2.5" totals along the I-64 corridor from Mount
Vernon IL into southwest IN.
In summary, broad 3 to 5 inch totals expected snow/sleet. Some
chance slightly lower 2 inch totals possible north, and higher 6+
inch totals a possibility across south-central ptns. Cant rule out
some hundredths of freezing rain across mainly srn border
counties, but focusing mostly on snow/sleet potential given
consistency of colder/further southern/eastern track.
Factors at play for a little more sleet vs snow include 3 to 6K
foot depth of warm nose ranging from -1C to +2C for at times 3 to
6 hrs of pcpn time period. This skews totals a little toward lower
end of aforementioned ratios, if it plays out.
Adjusted start time of WSW to 00z, given accumulating snows could
be ongoing at 03z for farthest western portions of SEMO/SWIL. End
time maintained at 18Z, but effectively ends at 15Z for all but
farthest southeastern counties...as pcpn shuts off sharply
northwest to southeast thru the morning hours Wednesday.
.LONG TERM...(Thursday through Tuesday)
Issued at 255 PM CST TUE JAN 19 2016
Another messy round of winter weather will follow our mid week
event. Models are in good agreement showing a low pressure system
centered over central Mississippi at 00z Friday. Being on the cold
side of the low along with the expected snow pack across our
region, a majority of the precipitation Thursday into Friday will
be freezing or frozen. Precipitation is expected to start as a mix
of freezing rain, sleet and snow across all but our north and
northwest counties, where precipitation should begin as snow and
remain snow through the event. Models imply temperatures briefly
reaching 33 to 37 degrees across most areas by Thursday afternoon,
which would switch us to rain. However confidence is a bit low on
how much warming we can get, so kept most areas as a mix except
for a portion of west Kentucky and southeast Missouri.
For Thursday night, any areas that begin as a mix will switch to
all snow by midnight as the low moves off to our southeast
overnight. The snow will continue into Friday, tapering off from
west to east Friday afternoon into Friday night. Right now 1 to 3
inches of snow is possible, but amounts are questionable at this
point and will greatly depend on how warm our surface temperatures
can get.
The weekend will be dry as high pressures moves across the Gulf of
Mexico. Temperatures will reach the middle 30s Saturday, and
around 40 degrees Sunday. Another round of precipitation will
return for Monday. Models take a surface low right over the PAH
forecast area late Monday into Monday night. Rain is possible
Monday, then as the low moves overhead and east of us, rain will
mix with and change over to snow Monday night. Rain or snow will
then be possible for Tuesday into Tuesday night, but we will have
to continue to watch the track of the low to see just how warm or
cold we will be for the beginning of the work week.
&&
.AVIATION...
Issued at 1118 PM CST TUE JAN 19 2016
Trends across Southern Illinois and into Southeast Missouri
finally closing in on lower visibilities and ceilings with
increased snowfall. May still be 1-2 hours fast at KPAH and KOWB,
but model guidance still suggesting a sharp increase in snowfall
after midnight, lowering ceilings and visibilities through
daybreak.
Made slight timing changes for lower ceilings at KCGI and KPAH,
but continued downward trend toward IFR conditions between 06-12z
Wednesday.
&&
.PAH Watches/Warnings/Advisories...
IL...Winter Storm Warning until noon CST Wednesday for ILZ075>078-
080>094.
MO...Winter Storm Warning until noon CST Wednesday for MOZ076-086-087-
100-107>112-114.
IN...Winter Storm Warning until noon CST Wednesday for INZ081-082-
085>088.
KY...Winter Storm Warning until noon CST Wednesday for KYZ001>022.
&&
$$
AVIATION...Smith
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1137 PM CST TUE JAN 19 2016
.AVIATION...
SCATTERED SHOWERS WILL ACCOMPANY AN EASTWARD MOVING COLD FRONT
DURING THE OVERNIGHT HOURS. SOUTHEAST WINDS AROUND 5 TO 10 KNOTS
AHEAD OF THE FRONT TO BECOME NORTHWEST BEHIND THE FRONT. CEILINGS
TO BECOME IFR AROUND DAYBREAK ACROSS AREA TERMINALS WITH LITTLE
IMPROVEMENT THROUGH 20/18Z. OTHERWISE...VFR CONDITIONS TO PREVAIL
THROUGH 21/00Z WITH MVFR/IFR CEILINGS POSSIBLE THEREAFTER. /05/
&&
.PREV DISCUSSION... /ISSUED 959 PM CST TUE JAN 19 2016/
DISCUSSION...
A LINE OF BROKEN CONVECTION HAS DEVELOPED OVER THE LAST COUPLE OF
HRS JUST AHEAD OF A COLD FRONT THAT IS ENTERING THE NWRN ZONES.
00Z KSHV RAOB SHOWS A PRONOUNCED DRY LAYER BETWEEN 850-560
MB...INDICATIVE OF SHOW MID LVL DRY SLOTTING IN THE WAKE OF A
DEPARTING SHORTWAVE TROUGH PER LATEST WV LOOPS. SOME ADDITIONAL
MID/UPPER LVL MOISTURE MOVING INTO THE SRN PLAINS COULD HELP THE
ATMOSPHERE MOISTEN FROM THE TOP DOWN IF IT ARRIVES BEFORE THE
FRONT. OTHERWISE...PRECIP WILL REMAIN SPOTTY AND SCATTERED AT
BEST. RAIN CHANCES MIGHT BE A BIT HIGHER ACROSS SRN AR DURING THE
EARLY MORNING HRS AS VERTICAL ASCENT MIGHT BE SLIGHTLY HIGHER DUE
TO THE PROXIMITY OF A SFC LOW AND THE UPPER TROUGH AXIS.
QUITE A FEW CHANGES WERE MADE IN THE GRIDS DURING THE FIRST 72 HRS
OF THE FCST BASED ON THE LATEST HRRR AND THE 00Z NAM. BIGGEST
CHANGES WERE MADE TO POPS AND TEMPS.
UPDATED PRODUCTS WILL BE SENT SHORTLY. /09/
PREV DISCUSSION... /ISSUED 540 PM CST TUE JAN 19 2016/
AVIATION...
CONDITIONS TO DETERIORATE OVERNIGHT AS A COLD FRONT MOVES ACROSS
THE AREA. CEILINGS TO BECOME MVFR AHEAD OF THE FRONT FOLLOWED BY
AN INCREASE IN COVERAGE OF RAIN SHOWERS AFTER 20/06Z. WINDS TO
BECOME NORTHWEST 5 TO 10 KNOTS BEHIND THE FRONT ACROSS MOST AREAS
BY DAYBREAK. OTHERWISE...IFR CEILINGS AND VISIBILITIES BETWEEN
20/12Z-20/16Z TO GRADUALLY IMPROVE THROUGHOUT THE DAY. /05/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 47 56 50 62 / 40 20 40 50
MLU 48 57 49 65 / 30 40 40 70
DEQ 39 49 40 53 / 40 10 50 60
TXK 41 50 45 56 / 50 10 50 60
ELD 43 52 44 58 / 50 40 50 70
TYR 41 53 49 60 / 40 10 40 40
GGG 43 54 50 61 / 40 10 40 50
LFK 47 59 54 65 / 30 20 30 40
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
05/05/05
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
316 PM EST WED JAN 20 2016
.SYNOPSIS...
A WEAK UPPER LEVEL SYSTEM PASSES ACROSS THE AREA LATE THIS
AFTERNOON THROUGH THIS EVENING. HIGH PRESSURE RETURNS THURSDAY
INTO THURSDAY NIGHT. A STRONG LOW PRESSURE SYSTEM WILL AFFECT THE
REGION FRIDAY INTO SUNDAY. HIGH PRESSURE RETURNS FOR EARLY NEXT
WEEK.
&&
.NEAR TERM /THROUGH THURSDAY/...
FIRST ORDER OF BUSINESS IS ELONGATED/WK TROUGH SFC-ALOFT CROSSING
MTNS ATTM. HI PRES INVOF FA LT THIS MRNG CONTG TO WEAKEN AS THAT
SYS APPROACHES THROUGH MID AFTN. LO LVLS RMN QUITE DRY...MDL
SOUNDINGS INDICATE SLO SATURATION ABV 5-7KFT INTO LT AFTN/EARLY
EVE. LATEST RUC HAS PD OF WK UVM ACCOMPANYING MOISTURE THROUGH THE
FA...21Z/20-00Z/21 WRN PORTION...23Z/20-04Z/21 CNTRL-E PORTIONS.
P-TYPE WILL NOT BE AN ISSUE...INSTEAD ITS QPF. GIVEN ONLY SLGT
RECOVERY TO DEWPTS AND LIMITED SATURATION BLO 5KFT...XPCG SN
RATIOS TO BE 15-20%. MENTIONING LGT SN...AND GIVEN ONLY BRIEF PD
OF ACTUAL PCPN OCCURRING...LGT ACCUMS (1/2" OR LESS) XPCTD. GROUND
COLD SO SHOULD NOT BE DIFFICULT TO HAVE ROADS COATED QUICKLY. WILL
MONITOR PCPN TRENDS EARLY/MID AFTN FOR PSBL NEED FOR AN (IMPACT
BASED) ADVISORY THIS EVE. TEMPS REBOUND INTO THE L30S MOST PLACES
THIS AFTN BEFORE THICKER CLDNS ARRIVES.
ONCE THIS TROUGH EXITS LT THIS EVE/OVRNGT...SFC PRES WILL BUILD
BACK INTO THE AREA. THE CLOUDS WILL CLEAR QUICKLY AND SHOULD ALLOW
TEMPERATURES TO DROP INTO THE LOW TO MID 20S. THE MOS GUIDANCE IS
FAIRLY WELL CLUSTERED TONIGHT SO DID NOT DEVIATE MUCH.
HIGH PRESSURE WILL REMAIN IN PLACE ON THURSDAY WITH SOME INCREASE
IN HIGH CLOUDS LATE IN THE DAY AS THE STORM SYSTEM OVER THE
SOUTHERN PLAINS BEGINS TO ORGANIZE. BUT WITH A MOSTLY SUNNY DAY
EXPECTED...TEMPERATURES SHOULD WARM INTO THE MID TO UPPER 30S.
WITH THE MAV NUMBERS HAVING BEEN RUNNING ON THE WARM SIDE HAVE
LEANED TOWARD THE COOLER MET NUMBERS.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/...
THE MODELS CONTINUE TO ADVERTISE A MAJOR STORM SYSTEM FOR THE
FRIDAY INTO THE WEEKEND TIME PERIOD. HOWEVER...THE TRACK AND
DETAILS OF WHERE THE COLD AND WARM AIR RESIDE ARE STILL
UNCERTAIN...WHICH LEADS TO SOME DIFFICULT IN NAILING DOWN SNOW
AREAS AND AMOUNTS. AS OF THE 00Z MODEL RUNS...THE GFS CONTINUES TO
BE FASTER THAN THE ECMWF AND NAM MODELS...BUT ALL MODELS ARE
SLOWER THAN LAST NIGHTS RUNS. SO HAVE AGAIN SLOWED THE ONSET OF
THE PCPN...BUT NOT NEARLY AS MUCH AS THE NAM/ECMWF SOLUTIONS. BUT
BY FRIDAY NIGHT...THE MODELS ALL AGREE THAT THE SFC LOW WILL
TRANSFER FROM THE OHIO VALLEY TO NEAR THE NORTHEASTERN NORTH
CAROLINA COAST. BUT THEY DIFFER BY ABOUT 100 MILES ON THE LOCATION
OF THE LOW WHICH IMPACTS HOW FAR NORTH AND WEST THE WARM AIR GOES.
FOR NOW...THE GFS HAS BEEN THE MODEL OF CHOICE SO HAVE GONE A
TOUCH FURTHER NORTH AND WEST WITH THE WARM AIR. THIS SETS UP A
SITUATION WHERE MUCH OF THE AREA BEGINS AS SNOW FRIDAY
MORNING...AS THE PCPN SPREADS ACROSS THE AREA FROM SW TO NE. AS
THE WARM AIR BEGINS TO LIFT NORTHWARD ALOFT WILL SEE A TRANSITION
FROM SNOW THROUGH A WINTRY MIX AND THEN TO ALL RAIN IN THE SE AND
WILL WATCH THAT TRANSITION LINE HEAD NE FRIDAY AFTERNOON AND
EVENING. EVENTUALLY...THIS SHOULD HAVE THE TRANSITIONS LINE NW OF
THE I-85 CORRIDOR/WEST OF RICHMOND AND THROUGH MUCH OF THE
NORTHERN NECK AND LOWER MD EASTERN SHORE COUNTIES. THE TREND OF
THE MODELS OVER THE LAST DAY OR SO HAS BEEN TO BE COLDER WITH EACH
RUN SO WHERE THIS TRANSITION LINE ENDS UP IS STILL UNCERTAIN.
FOR PCPN AMOUNTS...THE CURRENT THINKING IS THAT 1 - 2 INCHES OF
LIQUID PCPN ARE POSSIBLE THROUGH FRIDAY NIGHT WITH THE HEAVIEST OF
THAT IN THE EASTERN HALF OF THE REGION WHERE MUCH OF THIS WOULD
FALL AS RAIN. BUT TO THE NWRN PART OF THE AREA WHERE THE PCPN
SHOULD BE EITHER FROZEN OR A MIX...SUBSTANTIAL AMOUNTS ARE
POSSIBLE. INITIAL GUIDANCE FROM WPC HAS AMOUNTS OF 12 - 15 INCHES
OF SNOW OVER THE MOST NW PART OF THE CWA WITH 8 - 10 INCHES IN
RICHMOND VICINITY. CURRENT THINKING IS THOSE AMOUNTS...WHILE NOT
OUT OF THE REALM OF POSSIBILITY MAY BE A LITTLE HIGH THROUGH
FRIDAY NIGHT AS THE HEAVIER PCPN SHOULD BE FURTHER EAST. SO FOR
NOW HAVE LEANED MORE TOWARD 8 - 12 IN THE NORTHERN AND WESTERN
PORTIONS OF THE AREA AND 4 - 8 ACROSS THE RICHMOND METRO AREAS AND
LESS SOUTH AND EAST AS THE WARM AIR CHANGES THE PCPN TO RAIN.
AGAIN...THERE IS STILL MUCH UNCERTAIN AND AS THE EVENT GETS
CLOSER...THE TOTALS COULD EASILY CHANGE AS THE STORM TRACK AND
THERMODYNAMIC PROFILES CHANGE.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
LONG TERM PERIOD STARTS OFF SAT WITH THE AFOREMENTIONED LO PRES
SYSTM STRENGTHENING OFF THE MID ATLC CST. MAIN FORECAST CHANGE
WITH THIS UPDATE WAS TO INCREASE POPS BOTH SAT AND SAT NGT WITH A
GOOD DEAL OF PCPN LIKELY ON THE BACK SIDE OF THE LO. PTYPE
CONTINUES TO APPEAR TO BE SNOW OVER THE PIEDMONT...RAIN NR THE
CST...AND A RAIN/SNOW MIX IN BETWEEN. A LOT WILL DEPEND ON HOW
FAST LO-LEVEL THICKNESSES CRASH BEHIND THE DEPARTING LO. PCPN
SHOULD END FM W TO E SAT NGT. DRY CONDS EXPECTED THEN FOR SUN AND
MON WITH SFC HI PRES OVER THE AREA. TEMPS WILL RISE A LITTLE EACH
DAY...WITH HIGHS RANGING FM THE MID 30S OVER THE PIEDMONT TO THE
MID/UPR 40S NR THE CST SAT...INCREASING TO THE MID 40S TO LWR 50S
BY MON.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
VFR CONDITIONS WILL CONTINUE THRU AT LEAST MID TO LATE AFTN
TODAY. HOWEVER...CLOUDS WILL INCREASE AND LOWER QUICKLY FROM WEST
TO EAST AS AN UPPER LEVEL SYSTEM SWINGS THROUGH THE REGION THIS
EVENING. THIS SYSTEM WILL BRING A QUICK ROUND OF LIGHT SNOW TO ALL
TAF SITES FROM ROUGHLY 20/2300Z TO 21/0800Z. CONDITIONS DROP TO
MVFR WITH CIGS AROUND 2500FT AGL AND VISIBILITIES AROUND 3-4SM IN
-SN. LIGHT AND VARIABLE WINDS THIS AFTN WILL SHIFT TO THE NW AFTER
MIDNIGHT TONIGHT INTO THURSDAY MORNING BEHIND THE PASSING SYSTEM.
WINDS EXPECTED TO GUST UP TO 15-20KT ALONG CHES BAY AND THE
ATLANTIC COAST AS STRONGER WINDS MIX DOWN OVER THE WATERS. HIGH
PRESSURE PASSES OVER THE AREA ON THURSDAY. A STRONG WINTER STORM
WILL THEN AFFECT THE REGION LATE THU NIGHT INTO THE WEEKEND.
RAPIDLY DETERIORATING CONDITIONS DUE TO LOW CIG/VIS RESTRICTIONS
SHOULD BE ANTICIPATED BEGINNING FRIDAY AFTN.
&&
.MARINE...
AN ACTIVE WEATHER PATTERN WILL PREVAIL IN THE MARINE AREA FOR THE
NEXT SEVERAL DAYS. A WELL ADVERTISED STORM SYSTEM WILL PRODUCE ROUGH
CONDITIONS BEGINNING FRIDAY NIGHT.
IN THE MEANTIME...A WEAK LOW PRESSURE SYSTEM WILL MOVE THROUGH
OVERNIGHT. BEHIND IT NW WINDS WILL TEMPORARILY INCREASE. A SCA IS IN
EFFECT FOR THE CHESAPEAKE BAY AND CURRITUCK SOUND LATE TONIGHT
THROUGH MID MORNING THURSDAY.
HIGH PRESSURE BUILDS OVER THE WATERS THURSDAY AND THURSDAY NIGHT. A
DEVELOPING STORM SYSTEM OVER THE SOUTHERN STATES WILL EVENTUALLY
DEVELOP A LOW PRESSURE SYSTEM ON THE NORTH CAROLINA COAST. THIS
LOW WILL INTENSIFY FRIDAY EVENING. NE WINDS INCREASE RAPIDLY
AROUND 00Z FRIDAY EVENING. THE LOW MOVES TO OFF THE MD/VA COAST
SATURDAY. STRONG SCA TO GALE FORCE WINDS CAN BE EXPECTED AFTER
MIDNIGHT FRIDAY NIGHT INTO SATURDAY MORNING WITH GUSTS OVER 40
KNOTS EXPECTED IN THE BAY AND COASTAL WATERS. SOLID SCA WINDS
CONTINUES INTO SUNDAY. SEAS IN THE COASTAL WATERS WILL REMAIN 5
FT OR HIGHER THROUGH MONDAY MORNING.
THE PRESSURE PATTERN WEAKENS EARLY NEXT WEEK WITH QUIET MARINE
WEATHER DURING MUCH OF NEXT WEEK.
&&
.TIDES/COASTAL FLOODING...
LOW WATER ADVISORY EXTENDED THROUGH LATE THURSDAY AFTN FOR ALL
MARINE ZONES EXCEPT CURRITUCK SOUND...AND NC COASTAL WATERS DUE
TO WATER LEVELS EXPECTED TO REACH 1 TO 1.5 BELOW MEAN LOWER LOW
WATER. ADDED THE UPPER AND LOWER JAMES RIVER SINCE THE JAMESTOWN
BUOY HAS BEEN MEASURING BLOWOUT TIDES BTWN 1-2 FT BELOW MLLW.
TIDAL ANOMALIES ARE FORECAST TO INCREASE TO 1.5 TO 2.0 FT LATE
FRI INTO SAT...AS LO PRES IMPACTS THE REGION. THE COMBINATION OF
STRONG ONSHORE FLOW IN ADVANCE OF THE SYSTEM AND ASTRO TIDES
REACHING MHHW WILL PUSH COASTAL AREAS OF THE MD/VA EASTERN SHORE
AND SRN CHES BAY TOWARD MINOR FLOODING THRESHOLDS. STRONG NW
WINDS BEHIND THE DEPARTING SYSTEM WILL POTENTIALLY FAVOR MINOR
FLOODING OF THE CHESAPEAKE BAY SIDE OF THE LOWER EASTERN SHORE.
GALE CONDITIONS POSSIBLE LATE FRI NIGHT INTO SAT WITH SEAS
BUILDING TO 5 TO 12 FT COULD RESULT IN BEACH AND GENERAL SHORELINE
EROSION...ESPECIALLY FROM CHES BAY NWD ALONG THE ATLANTIC COAST.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...WINTER STORM WATCH FROM FRIDAY MORNING THROUGH SUNDAY MORNING
FOR MDZ021>023.
NC...WINTER STORM WATCH FROM FRIDAY MORNING THROUGH SUNDAY MORNING
FOR NCZ012.
VA...WINTER STORM WATCH FROM FRIDAY MORNING THROUGH SUNDAY MORNING
FOR VAZ048-060>062-064>069-075>090-092-509>522.
MARINE...LOW WATER ADVISORY UNTIL 3 PM EST THURSDAY FOR ANZ650-652-654-
656.
LOW WATER ADVISORY UNTIL 7 PM EST THURSDAY FOR ANZ630>632-634-
637-638.
SMALL CRAFT ADVISORY FROM 1 AM TO 10 AM EST THURSDAY FOR
ANZ630>634.
&&
$$
SYNOPSIS...AJZ
NEAR TERM...ALB/ESS
SHORT TERM...ESS
LONG TERM...MAS
AVIATION...BMD/TMG
MARINE...LSA
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
118 PM EST WED JAN 20 2016
.SYNOPSIS...
A WEAK UPPER LEVEL SYSTEM PASSES ACROSS THE AREA LATE THIS
AFTERNOON THROUGH THIS EVENING. HIGH PRESSURE RETURNS THURSDAY
INTO THURSDAY NIGHT. A STRONG LOW PRESSURE SYSTEM WILL AFFECT THE
REGION FRIDAY INTO SUNDAY. HIGH PRESSURE RETURNS FOR EARLY NEXT
WEEK.
&&
.NEAR TERM /THROUGH THURSDAY/...
FIRST ORDER OF BUSINESS IS ELONGATED/WK TROUGH SFC-ALOFT CROSSING
MTNS ATTM. HI PRES INVOF FA LT THIS MRNG CONTG TO WEAKEN AS THAT
SYS APPROACHES THROUGH MID AFTN. LO LVLS RMN QUITE DRY...MDL
SOUNDINGS INDICATE SLO SATURATION ABV 5-7KFT INTO LT AFTN/EARLY
EVE. LATEST RUC HAS PD OF WK UVM ACCOMPANYING MOISTURE THROUGH THE
FA...21Z/20-00Z/21 WRN PORTION...23Z/20-04Z/21 CNTRL-E PORTIONS.
P-TYPE WILL NOT BE AN ISSUE...INSTEAD ITS QPF. GIVEN ONLY SLGT
RECOVERY TO DEWPTS AND LIMITED SATURATION BLO 5KFT...XPCG SN
RATIOS TO BE 15-20%. MENTIONING LGT SN...AND GIVEN ONLY BRIEF PD
OF ACTUAL PCPN OCCURRING...LGT ACCUMS (1/2" OR LESS) XPCTD. GROUND
COLD SO SHOULD NOT BE DIFFICULT TO HAVE ROADS COATED QUICKLY. WILL
MONITOR PCPN TRENDS EARLY/MID AFTN FOR PSBL NEED FOR AN (IMPACT
BASED) ADVISORY THIS EVE. TEMPS REBOUND INTO THE L30S MOST PLACES
THIS AFTN BEFORE THICKER CLDNS ARRIVES.
ONCE THIS TROUGH EXITS LT THIS EVE/OVRNGT...SFC PRES WILL BUILD
BACK INTO THE AREA. THE CLOUDS WILL CLEAR QUICKLY AND SHOULD ALLOW
TEMPERATURES TO DROP INTO THE LOW TO MID 20S. THE MOS GUIDANCE IS
FAIRLY WELL CLUSTERED TONIGHT SO DID NOT DEVIATE MUCH.
HIGH PRESSURE WILL REMAIN IN PLACE ON THURSDAY WITH SOME INCREASE
IN HIGH CLOUDS LATE IN THE DAY AS THE STORM SYSTEM OVER THE
SOUTHERN PLAINS BEGINS TO ORGANIZE. BUT WITH A MOSTLY SUNNY DAY
EXPECTED...TEMPERATURES SHOULD WARM INTO THE MID TO UPPER 30S.
WITH THE MAV NUMBERS HAVING BEEN RUNNING ON THE WARM SIDE HAVE
LEANED TOWARD THE COOLER MET NUMBERS.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/...
THE MODELS CONTINUE TO ADVERTISE A MAJOR STORM SYSTEM FOR THE
FRIDAY INTO THE WEEKEND TIME PERIOD. HOWEVER...THE TRACK AND
DETAILS OF WHERE THE COLD AND WARM AIR RESIDE ARE STILL
UNCERTAIN...WHICH LEADS TO SOME DIFFICULT IN NAILING DOWN SNOW
AREAS AND AMOUNTS. AS OF THE 00Z MODEL RUNS...THE GFS CONTINUES TO
BE FASTER THAN THE ECMWF AND NAM MODELS...BUT ALL MODELS ARE
SLOWER THAN LAST NIGHTS RUNS. SO HAVE AGAIN SLOWED THE ONSET OF
THE PCPN...BUT NOT NEARLY AS MUCH AS THE NAM/ECMWF SOLUTIONS. BUT
BY FRIDAY NIGHT...THE MODELS ALL AGREE THAT THE SFC LOW WILL
TRANSFER FROM THE OHIO VALLEY TO NEAR THE NORTHEASTERN NORTH
CAROLINA COAST. BUT THEY DIFFER BY ABOUT 100 MILES ON THE LOCATION
OF THE LOW WHICH IMPACTS HOW FAR NORTH AND WEST THE WARM AIR GOES.
FOR NOW...THE GFS HAS BEEN THE MODEL OF CHOICE SO HAVE GONE A
TOUCH FURTHER NORTH AND WEST WITH THE WARM AIR. THIS SETS UP A
SITUATION WHERE MUCH OF THE AREA BEGINS AS SNOW FRIDAY
MORNING...AS THE PCPN SPREADS ACROSS THE AREA FROM SW TO NE. AS
THE WARM AIR BEGINS TO LIFT NORTHWARD ALOFT WILL SEE A TRANSITION
FROM SNOW THROUGH A WINTRY MIX AND THEN TO ALL RAIN IN THE SE AND
WILL WATCH THAT TRANSITION LINE HEAD NE FRIDAY AFTERNOON AND
EVENING. EVENTUALLY...THIS SHOULD HAVE THE TRANSITIONS LINE NW OF
THE I-85 CORRIDOR/WEST OF RICHMOND AND THROUGH MUCH OF THE
NORTHERN NECK AND LOWER MD EASTERN SHORE COUNTIES. THE TREND OF
THE MODELS OVER THE LAST DAY OR SO HAS BEEN TO BE COLDER WITH EACH
RUN SO WHERE THIS TRANSITION LINE ENDS UP IS STILL UNCERTAIN.
FOR PCPN AMOUNTS...THE CURRENT THINKING IS THAT 1 - 2 INCHES OF
LIQUID PCPN ARE POSSIBLE THROUGH FRIDAY NIGHT WITH THE HEAVIEST OF
THAT IN THE EASTERN HALF OF THE REGION WHERE MUCH OF THIS WOULD
FALL AS RAIN. BUT TO THE NWRN PART OF THE AREA WHERE THE PCPN
SHOULD BE EITHER FROZEN OR A MIX...SUBSTANTIAL AMOUNTS ARE
POSSIBLE. INITIAL GUIDANCE FROM WPC HAS AMOUNTS OF 12 - 15 INCHES
OF SNOW OVER THE MOST NW PART OF THE CWA WITH 8 - 10 INCHES IN
RICHMOND VICINITY. CURRENT THINKING IS THOSE AMOUNTS...WHILE NOT
OUT OF THE REALM OF POSSIBILITY MAY BE A LITTLE HIGH THROUGH
FRIDAY NIGHT AS THE HEAVIER PCPN SHOULD BE FURTHER EAST. SO FOR
NOW HAVE LEANED MORE TOWARD 8 - 12 IN THE NORTHERN AND WESTERN
PORTIONS OF THE AREA AND 4 - 8 ACROSS THE RICHMOND METRO AREAS AND
LESS SOUTH AND EAST AS THE WARM AIR CHANGES THE PCPN TO RAIN.
AGAIN...THERE IS STILL MUCH UNCERTAIN AND AS THE EVENT GETS
CLOSER...THE TOTALS COULD EASILY CHANGE AS THE STORM TRACK AND
THERMODYNAMIC PROFILES CHANGE.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
LONG TERM PERIOD STARTS OFF SAT WITH THE AFOREMENTIONED LO PRES
SYSTM STRENGTHENING OFF THE MID ATLC CST. MAIN FORECAST CHANGE
WITH THIS UPDATE WAS TO INCREASE POPS BOTH SAT AND SAT NGT WITH A
GOOD DEAL OF PCPN LIKELY ON THE BACK SIDE OF THE LO. PTYPE
CONTINUES TO APPEAR TO BE SNOW OVER THE PIEDMONT...RAIN NR THE
CST...AND A RAIN/SNOW MIX IN BETWEEN. A LOT WILL DEPEND ON HOW
FAST LO-LEVEL THICKNESSES CRASH BEHIND THE DEPARTING LO. PCPN
SHOULD END FM W TO E SAT NGT. DRY CONDS EXPECTED THEN FOR SUN AND
MON WITH SFC HI PRES OVER THE AREA. TEMPS WILL RISE A LITTLE EACH
DAY...WITH HIGHS RANGING FM THE MID 30S OVER THE PIEDMONT TO THE
MID/UPR 40S NR THE CST SAT...INCREASING TO THE MID 40S TO LWR 50S
BY MON.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
VFR CONDITIONS WILL CONTINUE THRU AT LEAST MID TO LATE AFTN
TODAY. HOWEVER...CLOUDS WILL INCREASE AND LOWER QUICKLY FROM WEST
TO EAST AS AN UPPER LEVEL SYSTEM SWINGS THROUGH THE REGION THIS
EVENING. THIS SYSTEM WILL BRING A QUICK ROUND OF LIGHT SNOW TO ALL
TAF SITES FROM ROUGHLY 20/2300Z TO 21/0800Z. CONDITIONS DROP TO
MVFR WITH CIGS AROUND 2500FT AGL AND VISIBILITIES AROUND 3-4SM IN
-SN. LIGHT AND VARIABLE WINDS THIS AFTN WILL SHIFT TO THE NW AFTER
MIDNIGHT TONIGHT INTO THURSDAY MORNING BEHIND THE PASSING SYSTEM.
WINDS EXPECTED TO GUST UP TO 15-20KT ALONG CHES BAY AND THE
ATLANTIC COAST AS STRONGER WINDS MIX DOWN OVER THE WATERS. HIGH
PRESSURE PASSES OVER THE AREA ON THURSDAY. A STRONG WINTER STORM
WILL THEN AFFECT THE REGION LATE THU NIGHT INTO THE WEEKEND.
RAPIDLY DETERIORATING CONDITIONS DUE TO LOW CIG/VIS RESTRICTIONS
SHOULD BE ANTICIPATED BEGINNING FRIDAY AFTN.
&&
.MARINE...
UPDATE...
SCA FLAGS ISSUED FOR CHES BAY AND CURRITUCK SOUND AFTER MIDNIGHT
TONIGHT INTO MID-THURSDAY MORNING AS NW WINDS INCREASE TO 15-20KT
BEHIND A SHORTWAVE PASSING THROUGH THE REGION THIS EVENING. WINDS
ALSO 15-20KT OVER ALL COASTAL WATERS BUT NOT STRONG ENOUGH TO
SUPPORT 25KT GUST CRITERIA FOR SCA FLAGS.
PREVIOUS DISCUSSION...
HIGH PRESSURE WILL BUILD RIGHT OVER THE WATERS THIS AFTN...THEN
WEAKEN AS AN UPPER LEVEL SYSTEM SLIDES ACROSS THE AREA AND OFF
THE COAST THIS EVENING. WINDS WILL BECOME WSW THIS AFTN THRU
EARLY TONIGHT...THEN BECOME NW AGAIN LATE TONIGHT INTO THU MORNING
BEHIND THE SYSTEM. HIGH PRES BUILDS INTO AND OVER THE AREA DURING
THU.
ATTENTION THEN TURNS TO A POTENT STORM SYSTEM SET TO IMPACT THE
REGION FRI INTO SUN. INCREASINGLY POOR BOATING CONDITIONS
ANTICIPATED BY LATER FRI THRU THE WEEKEND. NNW WINDS VEER AROUND
TO THE NNE EARLY FRI...THEN INCREASE FRI AFTN/EVENING...AS LOW
PRESSURE LIFTS ALONG THE SE COAST AND HIGH PRESSURE BUILDS INTO
CANADA. THE SFC LOW LIFTS OFF THE MID ATLANTIC COAST FRI NIGHT
INTO SAT...LIFTING AWAY FROM THE COAST SAT THRU SUN. STRONG SCA
WINDS EXPECTED LATER FRI INTO SUN...WITH GALE FORCE WINDS POSSIBLE
OVR THE COASTAL WATERS AND CHES BAY LATE FRI NIGHT INTO SUN...AS
FLOW TURNS FROM NE TO NNW. SEAS WILL ALSO BUILD QUICKLY REACHING
AS HIGH AS 8-12 FT SAT.
&&
.TIDES/COASTAL FLOODING...
LOW WATER ADVISORY EXTENDED THROUGH LATE THURSDAY AFTN FOR ALL
MARINE ZONES EXCEPT CURRITUCK SOUND...AND NC COASTAL WATERS DUE
TO WATER LEVELS EXPECTED TO REACH 1 TO 1.5 BELOW MEAN LOWER LOW
WATER. ADDED THE UPPER AND LOWER JAMES RIVER SINCE THE JAMESTOWN
BUOY HAS BEEN MEASURING BLOWOUT TIDES BTWN 1-2 FT BELOW MLLW.
TIDAL ANOMALIES ARE FORECAST TO INCREASE TO 1.5 TO 2.0 FT LATE
FRI INTO SAT...AS LO PRES IMPACTS THE REGION. THE COMBINATION OF
STRONG ONSHORE FLOW IN ADVANCE OF THE SYSTEM AND ASTRO TIDES
REACHING MHHW WILL PUSH COASTAL AREAS OF THE MD/VA EASTERN SHORE
AND SRN CHES BAY TOWARD MINOR FLOODING THRESHOLDS. STRONG NW
WINDS BEHIND THE DEPARTING SYSTEM WILL POTENTIALLY FAVOR MINOR
FLOODING OF THE CHESAPEAKE BAY SIDE OF THE LOWER EASTERN SHORE.
GALE CONDITIONS POSSIBLE LATE FRI NIGHT INTO SAT WITH SEAS
BUILDING TO 5 TO 12 FT COULD RESULT IN BEACH AND GENERAL SHORELINE
EROSION...ESPECIALLY FROM CHES BAY NWD ALONG THE ATLANTIC COAST.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...LOW WATER ADVISORY UNTIL 7 PM EST THURSDAY FOR ANZ630>632-634-
637-638.
SMALL CRAFT ADVISORY FROM 1 AM TO 10 AM EST THURSDAY FOR
ANZ630>634.
LOW WATER ADVISORY UNTIL 3 PM EST THURSDAY FOR ANZ650-652-654-
656.
&&
$$
SYNOPSIS...AJZ
NEAR TERM...ALB/ESS
SHORT TERM...ESS
LONG TERM...MAS
AVIATION...BMD/TMG
MARINE...BMD/TMG
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
1232 PM EST WED JAN 20 2016
.SYNOPSIS...
A WEAK UPPER LEVEL SYSTEM PASSES ACROSS THE AREA LATE THIS
AFTERNOON THROUGH THIS EVENING. HIGH PRESSURE RETURNS THURSDAY
INTO THURSDAY NIGHT. A STRONG LOW PRESSURE SYSTEM WILL AFFECT THE
REGION FRIDAY INTO SUNDAY. HIGH PRESSURE RETURNS FOR EARLY NEXT
WEEK.
&&
.NEAR TERM /THROUGH THURSDAY/...
FIRST ORDER OF BUSINESS IS ELONGATED/WK TROUGH SFC-ALOFT CROSSING
MTNS ATTM. HI PRES INVOF FA LT THIS MRNG CONTG TO WEAKEN AS THAT
SYS APPROACHES THROUGH MID AFTN. LO LVLS RMN QUITE DRY...MDL
SOUNDINGS INDICATE SLO SATURATION ABV 5-7KFT INTO LT AFTN/EARLY
EVE. LATEST RUC HAS PD OF WK UVM ACCOMPANYING MOISTURE THROUGH THE
FA...21Z/20-00Z/21 WRN PORTION...23Z/20-04Z/21 CNTRL-E PORTIONS.
P-TYPE WILL NOT BE AN ISSUE...INSTEAD ITS QPF. GIVEN ONLY SLGT
RECOVERY TO DEWPTS AND LIMITED SATURATION BLO 5KFT...XPCG SN
RATIOS TO BE 15-20%. MENTIONING LGT SN...AND GIVEN ONLY BRIEF PD
OF ACTUAL PCPN OCCURRING...LGT ACCUMS (1/2" OR LESS) XPCTD. GROUND
COLD SO SHOULD NOT BE DIFFICULT TO HAVE ROADS COATED QUICKLY. WILL
MONITOR PCPN TRENDS EARLY/MID AFTN FOR PSBL NEED FOR AN (IMPACT
BASED) ADVISORY THIS EVE. TEMPS REBOUND INTO THE L30S MOST PLACES
THIS AFTN BEFORE THICKER CLDNS ARRIVES.
ONCE THIS TROUGH EXITS LT THIS EVE/OVRNGT...SFC PRES WILL BUILD
BACK INTO THE AREA. THE CLOUDS WILL CLEAR QUICKLY AND SHOULD ALLOW
TEMPERATURES TO DROP INTO THE LOW TO MID 20S. THE MOS GUIDANCE IS
FAIRLY WELL CLUSTERED TONIGHT SO DID NOT DEVIATE MUCH.
HIGH PRESSURE WILL REMAIN IN PLACE ON THURSDAY WITH SOME INCREASE
IN HIGH CLOUDS LATE IN THE DAY AS THE STORM SYSTEM OVER THE
SOUTHERN PLAINS BEGINS TO ORGANIZE. BUT WITH A MOSTLY SUNNY DAY
EXPECTED...TEMPERATURES SHOULD WARM INTO THE MID TO UPPER 30S.
WITH THE MAV NUMBERS HAVING BEEN RUNNING ON THE WARM SIDE HAVE
LEANED TOWARD THE COOLER MET NUMBERS.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/...
THE MODELS CONTINUE TO ADVERTISE A MAJOR STORM SYSTEM FOR THE
FRIDAY INTO THE WEEKEND TIME PERIOD. HOWEVER...THE TRACK AND
DETAILS OF WHERE THE COLD AND WARM AIR RESIDE ARE STILL
UNCERTAIN...WHICH LEADS TO SOME DIFFICULT IN NAILING DOWN SNOW
AREAS AND AMOUNTS. AS OF THE 00Z MODEL RUNS...THE GFS CONTINUES TO
BE FASTER THAN THE ECMWF AND NAM MODELS...BUT ALL MODELS ARE
SLOWER THAN LAST NIGHTS RUNS. SO HAVE AGAIN SLOWED THE ONSET OF
THE PCPN...BUT NOT NEARLY AS MUCH AS THE NAM/ECMWF SOLUTIONS. BUT
BY FRIDAY NIGHT...THE MODELS ALL AGREE THAT THE SFC LOW WILL
TRANSFER FROM THE OHIO VALLEY TO NEAR THE NORTHEASTERN NORTH
CAROLINA COAST. BUT THEY DIFFER BY ABOUT 100 MILES ON THE LOCATION
OF THE LOW WHICH IMPACTS HOW FAR NORTH AND WEST THE WARM AIR GOES.
FOR NOW...THE GFS HAS BEEN THE MODEL OF CHOICE SO HAVE GONE A
TOUCH FURTHER NORTH AND WEST WITH THE WARM AIR. THIS SETS UP A
SITUATION WHERE MUCH OF THE AREA BEGINS AS SNOW FRIDAY
MORNING...AS THE PCPN SPREADS ACROSS THE AREA FROM SW TO NE. AS
THE WARM AIR BEGINS TO LIFT NORTHWARD ALOFT WILL SEE A TRANSITION
FROM SNOW THROUGH A WINTRY MIX AND THEN TO ALL RAIN IN THE SE AND
WILL WATCH THAT TRANSITION LINE HEAD NE FRIDAY AFTERNOON AND
EVENING. EVENTUALLY...THIS SHOULD HAVE THE TRANSITIONS LINE NW OF
THE I-85 CORRIDOR/WEST OF RICHMOND AND THROUGH MUCH OF THE
NORTHERN NECK AND LOWER MD EASTERN SHORE COUNTIES. THE TREND OF
THE MODELS OVER THE LAST DAY OR SO HAS BEEN TO BE COLDER WITH EACH
RUN SO WHERE THIS TRANSITION LINE ENDS UP IS STILL UNCERTAIN.
FOR PCPN AMOUNTS...THE CURRENT THINKING IS THAT 1 - 2 INCHES OF
LIQUID PCPN ARE POSSIBLE THROUGH FRIDAY NIGHT WITH THE HEAVIEST OF
THAT IN THE EASTERN HALF OF THE REGION WHERE MUCH OF THIS WOULD
FALL AS RAIN. BUT TO THE NWRN PART OF THE AREA WHERE THE PCPN
SHOULD BE EITHER FROZEN OR A MIX...SUBSTANTIAL AMOUNTS ARE
POSSIBLE. INITIAL GUIDANCE FROM WPC HAS AMOUNTS OF 12 - 15 INCHES
OF SNOW OVER THE MOST NW PART OF THE CWA WITH 8 - 10 INCHES IN
RICHMOND VICINITY. CURRENT THINKING IS THOSE AMOUNTS...WHILE NOT
OUT OF THE REALM OF POSSIBILITY MAY BE A LITTLE HIGH THROUGH
FRIDAY NIGHT AS THE HEAVIER PCPN SHOULD BE FURTHER EAST. SO FOR
NOW HAVE LEANED MORE TOWARD 8 - 12 IN THE NORTHERN AND WESTERN
PORTIONS OF THE AREA AND 4 - 8 ACROSS THE RICHMOND METRO AREAS AND
LESS SOUTH AND EAST AS THE WARM AIR CHANGES THE PCPN TO RAIN.
AGAIN...THERE IS STILL MUCH UNCERTAIN AND AS THE EVENT GETS
CLOSER...THE TOTALS COULD EASILY CHANGE AS THE STORM TRACK AND
THERMODYNAMIC PROFILES CHANGE.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
LONG TERM PERIOD STARTS OFF SAT WITH THE AFOREMENTIONED LO PRES
SYSTM STRENGTHENING OFF THE MID ATLC CST. MAIN FORECAST CHANGE
WITH THIS UPDATE WAS TO INCREASE POPS BOTH SAT AND SAT NGT WITH A
GOOD DEAL OF PCPN LIKELY ON THE BACK SIDE OF THE LO. PTYPE
CONTINUES TO APPEAR TO BE SNOW OVER THE PIEDMONT...RAIN NR THE
CST...AND A RAIN/SNOW MIX IN BETWEEN. A LOT WILL DEPEND ON HOW
FAST LO-LEVEL THICKNESSES CRASH BEHIND THE DEPARTING LO. PCPN
SHOULD END FM W TO E SAT NGT. DRY CONDS EXPECTED THEN FOR SUN AND
MON WITH SFC HI PRES OVER THE AREA. TEMPS WILL RISE A LITTLE EACH
DAY...WITH HIGHS RANGING FM THE MID 30S OVER THE PIEDMONT TO THE
MID/UPR 40S NR THE CST SAT...INCREASING TO THE MID 40S TO LWR 50S
BY MON.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
VFR CONDITIONS WILL CONTINUE THRU AT LEAST MID AFTN TODAY.
BUT...CLOUDS WILL INCREASE AND LWR QUICKLY...AS AN UPR LEVEL
SYSTEM MOVES TOWARDS THE REGION. THAT UPR LEVEL SYSTEM WILL THEN
CROSS THE REGION LATE THIS AFTN INTO EARLY TNGT...BRINGING A CHC
FOR SOME LIGHT SNOW. MAINLY VFR CIGS ARE STILL EXPECTED AS THE
LIGHT SNOW MOVES THRU. HOWEVER...MVFR CIGS WILL BE POSSIBLE...ESPLY
AT RIC/SBY/PHF. NW WINDS EARLY TODAY...WILL SHIFT TO THE W THEN SW
LATE THIS MORNG INTO EARLY TNGT...THEN BACK AGAIN TO THE NW OVRNGT
TNGT INTO THU MORNG BEHIND THE SYSTEM. HI PRES WILL PASS OVER THE
AREA ON THU. A STRONG WINTER STORM WILL THEN AFFECT THE REGION
LATE THU NGT INTO THE WEEKEND.
&&
.MARINE...
SCA CONDITIONS WILL CONTINUE UNTIL 10 AM THIS MORNG OVR ALL WTRS
EXCEPT THE RIVERS...DUE TO RATHER STRONG NW WINDS STILL OCCURRING
AS HI PRES BLDS JUST TO THE W OF THE WTRS. THE HI WILL BLD RIGHT
OVR THE WTRS EARLY THIS AFTN...THEN WEAKEN AS AN UPR LEVEL SYSTEM
SLIDES ACRS THE AREA AND OFF THE CST LATE THIS AFTN INTO EARLY
TNGT. WINDS WILL BECOME WSW THIS AFTN THRU EARLY TNGT...THEN BECOME
NW AGAIN LATE TNGT INTO THU MORNG BEHIND THE SYSTEM. HI PRES BLDS
INTO AND OVR THE AREA DURING THU.
ATTENTION THEN TURNS TO A POTENT STORM SYSTEM SET TO IMPACT THE
REGION FRI INTO SUN. INCREASINGLY POOR BOATING CONDITIONS ANTICIPATED
BY LATER FRI THRU THE WEEKEND. NNW WINDS VEER AROUND TO THE NNE
EARLY FRI...THEN INCREASE FRI AFTN/EVENG...AS LO PRES LIFTS ALONG
THE SE CST AND HI PRES BLDS INTO CANADA. THE SFC LOW LIFTS OFF THE
MID-ATLC CST FRI NIGHT INTO SAT...LIFTING AWAY FM THE CST SAT THRU
SUN. STRONG SCA WINDS EXPECTED LATER FRI INTO SUN...WITH GALE
FORCE WINDS POSSIBLE OVR THE CSTL WTRS AND CHES BAY LATE FRI NGT
INTO SUN...AS FLO TURNS FM NE TO NNW. SEAS WILL ALSO BLD QUICKLY
REACHING AS HIGH AS 8-12+ FT SAT.
&&
.TIDES/COASTAL FLOODING...
LOW WATER ADVISORY EXTENDED THROUGH LATE THURSDAY AFTN FOR ALL
MARINE ZONES EXCEPT CURRITUCK SOUND...AND NC COASTAL WATERS DUE
TO WATER LEVELS EXPECTED TO REACH 1 TO 1.5 BELOW MEAN LOWER LOW
WATER. ADDED THE UPPER AND LOWER JAMES RIVER SINCE THE JAMESTOWN
BUOY HAS BEEN MEASURING BLOWOUT TIDES BTWN 1-2 FT BELOW MLLW.
TIDAL ANOMALIES ARE FORECAST TO INCREASE TO 1.5 TO 2.0 FT LATE
FRI INTO SAT...AS LO PRES IMPACTS THE REGION. THE COMBINATION OF
STRONG ONSHORE FLOW IN ADVANCE OF THE SYSTEM AND ASTRO TIDES
REACHING MHHW WILL PUSH COASTAL AREAS OF THE MD/VA EASTERN SHORE
AND SRN CHES BAY TOWARD MINOR FLOODING THRESHOLDS. STRONG NW
WINDS BEHIND THE DEPARTING SYSTEM WILL POTENTIALLY FAVOR MINOR
FLOODING OF THE CHESAPEAKE BAY SIDE OF THE LOWER EASTERN SHORE.
GALE CONDITIONS POSSIBLE LATE FRI NIGHT INTO SAT WITH SEAS
BUILDING TO 5 TO 12 FT COULD RESULT IN BEACH AND GENERAL SHORELINE
EROSION...ESPECIALLY FROM CHES BAY NWD ALONG THE ATLANTIC COAST.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...LOW WATER ADVISORY UNTIL 7 PM EST THURSDAY FOR ANZ630>632-634-
637-638.
SMALL CRAFT ADVISORY FROM 1 AM TO 10 AM EST THURSDAY FOR
ANZ630>634.
LOW WATER ADVISORY UNTIL 3 PM EST THURSDAY FOR ANZ650-652-654-
656.
&&
$$
SYNOPSIS...AJZ
NEAR TERM...ALB/ESS
SHORT TERM...ESS
LONG TERM...MAS
AVIATION...TMG
MARINE...TMG
TIDES/COASTAL FLOODING...BMD
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
1041 AM EST WED JAN 20 2016
.SYNOPSIS...
A WEAK UPPER LEVEL SYSTEM PASSES ACROSS THE AREA LATE THIS
AFTERNOON THROUGH THIS EVENING. HIGH PRESSURE RETURNS THURSDAY
INTO THURSDAY NIGHT. A STRONG LOW PRESSURE SYSTEM WILL AFFECT THE
REGION FRIDAY INTO SUNDAY. HIGH PRESSURE RETURNS FOR EARLY NEXT
WEEK.
&&
.NEAR TERM /THROUGH THURSDAY/...
FIRST ORDER OF BUSINESS IS ELONGATED/WK TROUGH SFC-ALOFT CROSSING
MTNS ATTM. HI PRES INVOF FA LT THIS MRNG CONTG TO WEAKEN AS THAT
SYS APPROACHES THROUGH MID AFTN. LO LVLS RMN QUITE DRY...MDL
SOUNDINGS INDICATE SLO SATURATION ABV 5-7KFT INTO LT AFTN/EARLY
EVE. LATEST RUC HAS PD OF WK UVM ACCOMPANYING MOISTURE THROUGH THE
FA...21Z/20-00Z/21 WRN PORTION...23Z/20-04Z/21 CNTRL-E PORTIONS.
P-TYPE WILL NOT BE AN ISSUE...INSTEAD ITS QPF. GIVEN ONLY SLGT
RECOVERY TO DEWPTS AND LIMITED SATURATION BLO 5KFT...XPCG SN
RATIOS TO BE 15-20%. MENTIONING LGT SN...AND GIVEN ONLY BRIEF PD
OF ACTUAL PCPN OCCURRING...LGT ACCUMS (1/2" OR LESS) XPCTD. GROUND
COLD SO SHOULD NOT BE DIFFICULT TO HAVE ROADS COATED QUICKLY. WILL
MONITOR PCPN TRENDS EARLY/MID AFTN FOR PSBL NEED FOR AN (IMPACT
BASED) ADVISORY THIS EVE. TEMPS REBOUND INTO THE L30S MOST PLACES
THIS AFTN BEFORE THICKER CLDNS ARRIVES.
ONCE THIS TROUGH EXITS LT THIS EVE/OVRNGT...SFC PRES WILL BUILD
BACK INTO THE AREA. THE CLOUDS WILL CLEAR QUICKLY AND SHOULD ALLOW
TEMPERATURES TO DROP INTO THE LOW TO MID 20S. THE MOS GUIDANCE IS
FAIRLY WELL CLUSTERED TONIGHT SO DID NOT DEVIATE MUCH.
HIGH PRESSURE WILL REMAIN IN PLACE ON THURSDAY WITH SOME INCREASE
IN HIGH CLOUDS LATE IN THE DAY AS THE STORM SYSTEM OVER THE
SOUTHERN PLAINS BEGINS TO ORGANIZE. BUT WITH A MOSTLY SUNNY DAY
EXPECTED...TEMPERATURES SHOULD WARM INTO THE MID TO UPPER 30S.
WITH THE MAV NUMBERS HAVING BEEN RUNNING ON THE WARM SIDE HAVE
LEANED TOWARD THE COOLER MET NUMBERS.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/...
THE MODELS CONTINUE TO ADVERTISE A MAJOR STORM SYSTEM FOR THE
FRIDAY INTO THE WEEKEND TIME PERIOD. HOWEVER...THE TRACK AND
DETAILS OF WHERE THE COLD AND WARM AIR RESIDE ARE STILL
UNCERTAIN...WHICH LEADS TO SOME DIFFICULT IN NAILING DOWN SNOW
AREAS AND AMOUNTS. AS OF THE 00Z MODEL RUNS...THE GFS CONTINUES TO
BE FASTER THAN THE ECMWF AND NAM MODELS...BUT ALL MODELS ARE
SLOWER THAN LAST NIGHTS RUNS. SO HAVE AGAIN SLOWED THE ONSET OF
THE PCPN...BUT NOT NEARLY AS MUCH AS THE NAM/ECMWF SOLUTIONS. BUT
BY FRIDAY NIGHT...THE MODELS ALL AGREE THAT THE SFC LOW WILL
TRANSFER FROM THE OHIO VALLEY TO NEAR THE NORTHEASTERN NORTH
CAROLINA COAST. BUT THEY DIFFER BY ABOUT 100 MILES ON THE LOCATION
OF THE LOW WHICH IMPACTS HOW FAR NORTH AND WEST THE WARM AIR GOES.
FOR NOW...THE GFS HAS BEEN THE MODEL OF CHOICE SO HAVE GONE A
TOUCH FURTHER NORTH AND WEST WITH THE WARM AIR. THIS SETS UP A
SITUATION WHERE MUCH OF THE AREA BEGINS AS SNOW FRIDAY
MORNING...AS THE PCPN SPREADS ACROSS THE AREA FROM SW TO NE. AS
THE WARM AIR BEGINS TO LIFT NORTHWARD ALOFT WILL SEE A TRANSITION
FROM SNOW THROUGH A WINTRY MIX AND THEN TO ALL RAIN IN THE SE AND
WILL WATCH THAT TRANSITION LINE HEAD NE FRIDAY AFTERNOON AND
EVENING. EVENTUALLY...THIS SHOULD HAVE THE TRANSITIONS LINE NW OF
THE I-85 CORRIDOR/WEST OF RICHMOND AND THROUGH MUCH OF THE
NORTHERN NECK AND LOWER MD EASTERN SHORE COUNTIES. THE TREND OF
THE MODELS OVER THE LAST DAY OR SO HAS BEEN TO BE COLDER WITH EACH
RUN SO WHERE THIS TRANSITION LINE ENDS UP IS STILL UNCERTAIN.
FOR PCPN AMOUNTS...THE CURRENT THINKING IS THAT 1 - 2 INCHES OF
LIQUID PCPN ARE POSSIBLE THROUGH FRIDAY NIGHT WITH THE HEAVIEST OF
THAT IN THE EASTERN HALF OF THE REGION WHERE MUCH OF THIS WOULD
FALL AS RAIN. BUT TO THE NWRN PART OF THE AREA WHERE THE PCPN
SHOULD BE EITHER FROZEN OR A MIX...SUBSTANTIAL AMOUNTS ARE
POSSIBLE. INITIAL GUIDANCE FROM WPC HAS AMOUNTS OF 12 - 15 INCHES
OF SNOW OVER THE MOST NW PART OF THE CWA WITH 8 - 10 INCHES IN
RICHMOND VICINITY. CURRENT THINKING IS THOSE AMOUNTS...WHILE NOT
OUT OF THE REALM OF POSSIBILITY MAY BE A LITTLE HIGH THROUGH
FRIDAY NIGHT AS THE HEAVIER PCPN SHOULD BE FURTHER EAST. SO FOR
NOW HAVE LEANED MORE TOWARD 8 - 12 IN THE NORTHERN AND WESTERN
PORTIONS OF THE AREA AND 4 - 8 ACROSS THE RICHMOND METRO AREAS AND
LESS SOUTH AND EAST AS THE WARM AIR CHANGES THE PCPN TO RAIN.
AGAIN...THERE IS STILL MUCH UNCERTAIN AND AS THE EVENT GETS
CLOSER...THE TOTALS COULD EASILY CHANGE AS THE STORM TRACK AND
THERMODYNAMIC PROFILES CHANGE.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
LONG TERM PERIOD STARTS OFF SAT WITH THE AFOREMENTIONED LO PRES
SYSTM STRENGTHENING OFF THE MID ATLC CST. MAIN FORECAST CHANGE
WITH THIS UPDATE WAS TO INCREASE POPS BOTH SAT AND SAT NGT WITH A
GOOD DEAL OF PCPN LIKELY ON THE BACK SIDE OF THE LO. PTYPE
CONTINUES TO APPEAR TO BE SNOW OVER THE PIEDMONT...RAIN NR THE
CST...AND A RAIN/SNOW MIX IN BETWEEN. A LOT WILL DEPEND ON HOW
FAST LO-LEVEL THICKNESSES CRASH BEHIND THE DEPARTING LO. PCPN
SHOULD END FM W TO E SAT NGT. DRY CONDS EXPECTED THEN FOR SUN AND
MON WITH SFC HI PRES OVER THE AREA. TEMPS WILL RISE A LITTLE EACH
DAY...WITH HIGHS RANGING FM THE MID 30S OVER THE PIEDMONT TO THE
MID/UPR 40S NR THE CST SAT...INCREASING TO THE MID 40S TO LWR 50S
BY MON.
&&
.AVIATION /16Z WEDNESDAY THROUGH SUNDAY/...
VFR CONDITIONS WILL CONTINUE THRU AT LEAST MID AFTN TODAY.
BUT...CLOUDS WILL INCREASE AND LWR QUICKLY...AS AN UPR LEVEL
SYSTEM MOVES TOWARDS THE REGION. THAT UPR LEVEL SYSTEM WILL THEN
CROSS THE REGION LATE THIS AFTN INTO EARLY TNGT...BRINGING A CHC
FOR SOME LIGHT SNOW. MAINLY VFR CIGS ARE STILL EXPECTED AS THE
LIGHT SNOW MOVES THRU. HOWEVER...MVFR CIGS WILL BE POSSIBLE...ESPLY
AT RIC/SBY/PHF. NW WINDS EARLY TODAY...WILL SHIFT TO THE W THEN SW
LATE THIS MORNG INTO EARLY TNGT...THEN BACK AGAIN TO THE NW OVRNGT
TNGT INTO THU MORNG BEHIND THE SYSTEM. HI PRES WILL PASS OVER THE
AREA ON THU. A STRONG WINTER STORM WILL THEN AFFECT THE REGION
LATE THU NGT INTO THE WEEKEND.
&&
.MARINE...
SCA CONDITIONS WILL CONTINUE UNTIL 10 AM THIS MORNG OVR ALL WTRS
EXCEPT THE RIVERS...DUE TO RATHER STRONG NW WINDS STILL OCCURRING
AS HI PRES BLDS JUST TO THE W OF THE WTRS. THE HI WILL BLD RIGHT
OVR THE WTRS EARLY THIS AFTN...THEN WEAKEN AS AN UPR LEVEL SYSTEM
SLIDES ACRS THE AREA AND OFF THE CST LATE THIS AFTN INTO EARLY
TNGT. WINDS WILL BECOME WSW THIS AFTN THRU EARLY TNGT...THEN BECOME
NW AGAIN LATE TNGT INTO THU MORNG BEHIND THE SYSTEM. HI PRES BLDS
INTO AND OVR THE AREA DURING THU.
ATTENTION THEN TURNS TO A POTENT STORM SYSTEM SET TO IMPACT THE
REGION FRI INTO SUN. INCREASINGLY POOR BOATING CONDITIONS ANTICIPATED
BY LATER FRI THRU THE WEEKEND. NNW WINDS VEER AROUND TO THE NNE
EARLY FRI...THEN INCREASE FRI AFTN/EVENG...AS LO PRES LIFTS ALONG
THE SE CST AND HI PRES BLDS INTO CANADA. THE SFC LOW LIFTS OFF THE
MID-ATLC CST FRI NIGHT INTO SAT...LIFTING AWAY FM THE CST SAT THRU
SUN. STRONG SCA WINDS EXPECTED LATER FRI INTO SUN...WITH GALE
FORCE WINDS POSSIBLE OVR THE CSTL WTRS AND CHES BAY LATE FRI NGT
INTO SUN...AS FLO TURNS FM NE TO NNW. SEAS WILL ALSO BLD QUICKLY
REACHING AS HIGH AS 8-12+ FT SAT.
&&
.TIDES/COASTAL FLOODING...
ISSUED LOW WATER ADVISORY FOR ALL MARINE ZNS EXCEPT THE
RIVERS...CURRITUCK SND...AND NC CSTL WTRS FM 9 AM THIS MORNG UNTIL
2 PM...DUE TO WATER LEVELS EXPECTED TO REACH 1 TO 1.5 BELOW MEAN
LOWER LOW WATER.
TIDAL ANOMALIES ARE FORECAST TO REACH 1.5 TO 2.0 FEET LATE FRI
INTO SAT...AS LO PRES IMPACTS THE REGION. COMBINATION OF STRONG
ONSHORE FLOW IN ADVANCE OF THE SYSTEM AND ASTRO TIDES REACHING
MHHW WILL PUSH CSTL AREAS OF THE ERN SHORE TOWARD MINOR FLOODING
THRESHOLDS. STRONG NW WINDS BEHIND THE DEPARTING SYSTEM WILL
POTENTIALLY FAVOR MINOR FLOODING OF THE CHESAPEAKE BAY SIDE OF THE
LOWER EASTERN SHORE.
WITH GALE CONDITIONS POSSIBLE LATE FRI NGT INTO SAT AND SEAS
BUILDING TO 5 TO 12 FT...BEACH EROSION AND GENERAL SHORELINE
EROSION IS EXPECTED ESPECIALLY ALONG THE LOWER BAY AND PORTIONS OF
THE CST.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...LOW WATER ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR
ANZ630>632-634-650-652-654-656.
&&
$$
SYNOPSIS...AJZ
NEAR TERM...ALB/ESS
SHORT TERM...ESS
LONG TERM...MAS
AVIATION...TMG
MARINE...TMG
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1019 PM EST THU JAN 21 2016
LATEST UPDATE...
UPDATE
.SYNOPSIS...
ISSUED AT 329 PM EST THU JAN 21 2016
SOME LIGHT LAKE EFFECT SNOW SHOWERS WILL CONTINUE INTO THE EVENING
HOURS BEFORE WINDING DOWN OVERNIGHT. ACCUMULATIONS WILL BE
LIGHT...ON THE ORDER OF A DUSTING. QUIET WEATHER IS FORECAST THROUGH
THE WEEKEND AS A WINTER STORM SYSTEM PIVOTS OFF THE EAST COAST OF
THE UNITED STATES. WE WILL SEE DRY WEATHER FRIDAY...SATURDAY AND
SUNDAY. CLOUD COVER WILL DECREASE A BIT EACH DAY. HIGH TEMPERATURES
THROUGH THE WEEKEND WILL BE NEAR NORMAL AROUND 30 DEGREES.
&&
.UPDATE...
ISSUED AT 1020 PM EST THU JAN 21 2016
I UPDATED THE FORECAST GRIDS TO SHOW THE WEST TO EAST SNOW BAND
THAT HAS BEEN HERE ALL EVENING. IT SHOULD DISSIPATE BY 5 AM AS
WINDS TURN NORTHEAST FROM 850 MB TO THE GROUND.
LIGHT SNOW CONTINUED TO FALL IN AN EAST TO WEST BAND GENERALLY
ALONG I-96 (MORE OR LESS). CURIOUSLY THIS BAND IS WHERE THE
SURFACE DEW POINTS ARE THE HIGHEST (WHICH WOULD MAKE SENSE SINCE
IT IS SNOWING IN THIS AREA). THERE SEEMS TO BE SOME SORT OF
CONVERGENCE FEATURE IN THIS AREA AROUND 925 MB. IN ANY EVENT...AS
THE SYSTEM TO OUR SOUTH GETS CLOSER...WINDS TURN NORTHEAST ACROSS
LOWER MICHIGAN BY 5 AM (IN THE 925 TO 850 MB LAYER)...SO THAT
WILL END THIS FEATURE. THE RAP MODEL SHOWS IT SLOWLY LIFTING NORTH
SO THAT IS WHAT I DID WITH IT IN THE GRIDS.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 329 PM EST THU JAN 21 2016
ONGOING LAKE EFFECT IS SOMEWHAT SPOTTY IN NATURE WITH THE BANDS
LOOKING MORE LIKE PLUMES AS OF 300 PM. JUST ENOUGH INSTABILITY AND
MOISTURE ARE PRESENT TO PROVIDE SOME SHALLOW LAKE EFFECT SNOW
SHOWERS. REFLECTIVITY HAS COME DOWN JUST A BIT WITHIN THE LAST HOUR.
NOT EXPECTING MUCH IN THE WAY OF ACCUMULATION THIS EVENING OR
TONIGHT GIVEN THE WEAKENING FLOW. NOT OUT OF THE QUESTION TO SEE AN
ADDITIONAL FEW TENTHS OF AN INCH OF SNOW IN SPOTS WHERE THE WEAK
BANDS REMAIN THOUGH THROUGH MID EVENING.
OVERNIGHT THE FLOW SHIFTS TO THE NORTH IN RESPONSE TO THE DEEPENING
LOW IN THE SOUTH. THIS SHOULD TAKE ANY REMAINING LAKE EFFECT TOWARD
THE LAKE MICHIGAN SHORE. ON FRIDAY...THE FLOW GOES NORTHEAST WHICH
SHOULD TAKE ANY WEAK BANDING OFF SHORE. HAVE SOME SMALL CHANCE POPS
IN FOR TONIGHT IN THE WEST AND THEN WENT WITH A DRY FORECAST ON
FRIDAY.
A NORTHEAST FLOW REMAINS IN PLACE ON FRIDAY NIGHT...FOLLOWED BY A
RIDGE SHIFTING THROUGH ON SATURDAY. SATURDAY NIGHT THE FLOW GOES
SOUTHWEST. ESSENTIALLY...QUIET WEATHER WILL CONTINUE IN THESE THREE
FORECAST PERIODS. FRIDAY NIGHT CLOUDS WILL STREAM INTO THE CWA OFF
OF LAKE HURON. CANNOT RULE OUT SOME FLURRIES BUT KEPT THE FORECAST
DRY FOR NOW. SATURDAY...SOME SUNSHINE SHOULD DEVELOP AS INSTABILITY
WANES IN A WARM AIR ADVECTION REGIME. ANY PRECIPITATION ASSOCIATED
WITH A LOW MOVING THROUGH THE NORTHERN GREAT LAKES SATURDAY NIGHT
SHOULD REMAIN WELL NORTH OF OUR AREA.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 329 PM EST THU JAN 21 2016
THE REGION IS LOOKING AT A SOMEWHAT UNSETTLED WEATHER PATTERN IN THE
LONG TERM WHILE TEMPERATURES WILL BE GENERALLY IN A RANGE OF
SEASONABLE VALUES.
THE LONG TERM WILL START OUT ON THE QUIET SIDE FOR THE STATE WITH
MAINLY DRY WEATHER EXPECTED INTO SUN NIGHT. WE WILL SEE AN UPPER
RIDGE BUILDING OVER THE REGION AT THAT TIME...IN THE WAKE OF THE BIG
EAST COAST STORM AND THE NEXT UPPER TROUGH THAT WILL BE APPROACHING
THE AREA. THERE IS A SHORT WAVE RIDING OVER THE RIDGE THAT LOOKS TO
STAY FAR ENOUGH NORTH TO AFFECT THE AREA.
WE ARE LOOKING AT SOME RAIN AND SNOW MOVING INTO THE AREA LATE ON
MON...AND ESPECIALLY MON NIGHT. WE WILL SEE AN UPPER TROUGH THAT
MOVES ONSHORE OVER THE WEST COAST EARLY THIS COMING WEEKEND. THIS
WILL TRAVERSE THE COUNTRY AND COME INTO THE AREA LATE MON. THIS
TROUGH WILL DRAW SOME MILDER AND MORE MOIST AIR FROM THE GULF NORTH
INTO THE AREA. IT LOOKS LIKE THERE IS A GOOD CHC THAT PCPN WILL
START OUT AS RAIN AND CHANGE OVER TO SNOW LATE MON NIGHT INTO EARLY
TUE MORNING. SOME LIGHT ACCUMULATIONS OF SNOW REMAIN POSSIBLE.
WE WILL THEN SEE LAKE EFFECT SNOW SHOWERS TAKE SHAPE FOR THE TUE
INTO WED TIME FRAME. THE UPPER JET WILL BE NEARBY...BUT WE ARE NOT
LOOKING AT AS COLD OF TEMPERATURES AS THE PAST FEW DAYS. THERE IS
SOME POTENTIAL FOR SOME ENHANCED AMOUNTS AS MOISTURE LOOKS RATHER
PLENTIFUL...INVERSION HEIGHTS ARE UP A LITTLE...AND THE MODELS ARE
KEYING IN ON SOME CONVERGENCE BANDS. DETAILS ARE A BIT UNCLEAR YET
BEING A FEW DAYS OUT YET. ANOTHER BURST OF SNOW WILL BE POSSIBLE ON
THU AS A MORE DEFINED SHORT WAVE MOVES THROUGH.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 652 PM EST THU JAN 21 2016
CEILINGS ARE EXPECTED TO REMAIN AROUND 2500 FEET OVERNIGHT AND
INTO FRIDAY. CEILINGS SHOULD COME UP ABOVE 3500 FEET LATE FRIDAY
AFTERNOON. WINDS WILL BE LIGHT AND VARIABLE TONIGHT AND NORTHEAST
AOB 10 KNOTS ON FRIDAY.
&&
.MARINE...
ISSUED AT 329 PM EST THU JAN 21 2016
A FAIRLY LIGHT WIND REGIME WILL BE IN PLACE ACROSS THE SOUTHERN HALF
OF LAKE MICHIGAN THROUGH SATURDAY. A RIDGE OF HIGH PRESSURE WILL BE
SITUATED ACROSS THE GREAT LAKES REGION WHICH WILL KEEP WINDS AND
WAVES BELOW SMALL CRAFT ADVISORY CRITERIA THROUGH SATURDAY.
SOUTHWEST WINDS WILL INCREASE SATURDAY NIGHT INTO SUNDAY WHICH MAY
LEAD TO THE NEED OF AN SCA. SOUTHWEST WINDS LOOK TO REACH THE 15 TO
25 KNOT RANGE. WAVES WILL LIKELY PUSH INTO THE 3 TO 5 FOOT RANGE AS
WE HEAD INTO SUNDAY...ESPECIALLY FROM HOLLAND NORTHWARD.
&&
.HYDROLOGY...
ISSUED AT 329 PM EST THU JAN 21 2016
ICE JAMS HAVE FORMED IN SPOTS ALONG SEVERAL RIVERS. A GENERAL RISE
IN RIVER LEVELS WITH OCCASIONAL DOWNWARD FLUCTUATIONS HAS BEEN
OCCURRING IN SPOTS SUCH AS IONIA... EAGLE... SMYRNA... AND
SCOTTVILLE. IONIA HAS SURPASSED BANKFULL AND THE OTHER THREE ARE
CURRENTLY EXPECTED TO REMAIN JUST BELOW BANKFULL BUT WILL BE
MONITORED.
WITH BELOW-FREEZING WEATHER CONTINUING THROUGH THE REMAINDER OF THE
WEEK... LITTLE CHANGE IN THE ICE JAMS IS EXPECTED... AND RIVER
LEVELS SHOULD REMAIN ELEVATED UPSTREAM OF THE JAMS. SIGNIFICANT
FLOODING IS NOT AN IMMEDIATE CONCERN. NEVERTHELESS... ICE JAMS CAN
CAUSE RELATIVELY RAPID CHANGES IN RIVER LEVELS UPSTREAM AND
DOWNSTREAM OF THE JAM WITH LITTLE ADVANCE NOTICE.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...DUKE
SHORT TERM...DUKE
LONG TERM...NJJ
AVIATION...OSTUNO
HYDROLOGY...CAS
MARINE...DUKE
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
150 PM EST WED JAN 20 2016
LATEST UPDATE...
HYDRO
.SYNOPSIS...
ISSUED AT 315 AM EST WED JAN 20 2016
AN UPPER LEVEL DISTURBANCE WILL BRING MORE LIGHT SNOW TODAY.
TEMPERATURES WILL REMAIN SEASONABLY COLD TODAY BEFORE A GRADUAL
MODERATING TREND OF TEMPERATURES OCCURS LATE THIS WEEK. THE NEXT
CHANCE FOR ACCUMULATING SNOW WILL NOT COME UNTIL VERY LATE THIS
WEEKEND OR EARLY NEXT WEEK.
&&
.UPDATE...
ISSUED AT 1233 PM EST WED JAN 20 2016
THE MESO-SCALE HEAVY SNOW BAND AS MOVES SOMEWHAT TO THE SOUTH AND
IS NOW MOSTLY BETWEEN MUSKEGON AND GRAND HAVEN. DUAL POLE RADAR
SHOWS STORM TOTALS BETWEEN 3 TO 4 INCHES HAS FALLEN IN THAT AREA.
SINCE THE LATEST MODEL DATA SUGGESTS THE BAND WILL NOT START
MOVING ON SHORE UNTIL AROUND 3 PM... I EXTENDED THE ADVIOSRY TILL
4 PM.
UPDATE ISSUED AT 1102 AM EST WED JAN 20 2016
I PLAN TO KEEP OUR WINTER WEATHER ADVISORY GOING AS IS FOR NOW.
THE LATEST MODEL DATA SHOWS THE AREA OF STRONG MESO-SCALE FORCING
REMAINING LARGELY STATIONARY TILL 18Z. THE AREA THAT THETA-E
DECREASE WITH HEIGHT BETWEEN 1000 MB AND 925 MB IS RATHER NARROW
AND DOES NOT MOVE UNTIL AFTER 18Z. THE 88D RADAR SHOWS THE
STRONGEST RADAR RETURNS OVER THE AREA WITH THE GREATEST THETA-E
DECREASING WITH HEIGHT AND IN TURN THE GREATEST VERTICAL MOTION.
REPORTS SO FAR SHOW 1 TO 2 INCHES HAS FALLEN... I COULD SEE
ANOTHER INCH OR SO FALL THERE BEFORE THE BAND WEAKENS AND MOVES
EAST MID TO LATE AFTERNOON. ELSEWHERE EXPECT MOSTLY CLOUDY SKIES
WITH FLURRIES.
UPDATE ISSUED AT 551 AM EST WED JAN 20 2016
CURRENTLY CONSIDERING A WINTER STORM WARNING FOR MUSKEGON COUNTY
GIVEN CURRENT TRENDS:
A DOMINANT LAKE EFFECT BAND IS ONGOING AT THIS TIME ACROSS
SOUTHERN MUSKEGON COUNTY. HRRR SFC WIND FIELDS AND SIM REF
SUGGESTS THIS BAND MAY MIGRATE EAST SOMEWHAT OVER THE NEXT 3 TO 6
HOURS BUT LARGELY BE IMPACTING THE SAME AREAS...NAMELY GRAND HAVEN
TO WHITEHALL. LAND BASED OBS ARE SHOWING SSE WINDS ALONG THE COAST
WHILE WSW WINDS ARE COMING OFF THE LAKE. THIS WILL CONTINUE
CREATING LOW LEVEL CONVERGENCE AND MAY KEEP THIS MATURE BAND
GOING FOR SEVERAL HOURS. MOISTURE DEPTH STAYS AT OR ABOVE 10K FT
THROUGH 18Z. HRRR GUIDANCE SUGGESTS IT MAY NOT MOVE OUT OF THE
CURRENT AREA UNTIL 18Z OR SO. SNOWFALL RATES OF 1"-2" PER HOUR ARE
EXPECTED WITHIN THIS BAND WITH VISIBILITIES TO A QUARTER MILE OR
LESS AND POOR TRAVEL. ADDITIONAL SNOWFALL OF 3"-6" OR MORE COULD
EASILY BE ACHIEVED IN THE HARDEST HIT AREAS...FROM GRAND HAVEN TO
WHITEHALL.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 315 AM EST WED JAN 20 2016
LIGHT SNOW IS ANTICIPATED TODAY AS AN UPPER LEVEL SYSTEM MOVES
ACROSS LWR MI. MOST OF OUR FCST AREA WILL ONLY RECEIVE LESS THAN AN
INCH OF SNOW.
THE EXCEPTION TO THIS IS FROM ALLEGAN COUNTY NORTHWARD TO MKG
COUNTY WHERE SW FLOW LAKE ENHANCEMENT WILL OCCUR ALONG WITH SOME
ENHANCED LIFT. SNOW SHOULD GRADUALLY INCREASE IN COVERAGE AND
INTENSITY DURING THE EARLY TO MID MORNING HOURS THERE AS THE UPPER
TROF AXIS APPROACHES. 2 TO 4 INCHES OF SNOW IS ANTICIPATED ACROSS
PORTIONS OF THOSE COUNTIES WHERE THE WINTER WX ADVISORY REMAINS IN
EFFECT UNTIL 18Z THIS AFTN.
TRANQUIL WX IS ANTICIPATED TONIGHT THROUGH FRIDAY WITH JUST A FEW
LINGERING FLURRIES OR VERY LIGHT SNOW SHOWERS NEAR LAKE MI
TONIGHT. TEMPS WILL UNDERGO A GRADUAL MODERATING TREND AND REACH
THE MIDDLE 20S THURSDAY AND AROUND 30 DEGREES ON FRIDAY.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 315 AM EST WED JAN 20 2016
OUR MAIN FOCUS FOR THE EXTENDED FORECAST CONTINUES TO CENTER ON A
CHANCE FOR LIGHT SNOW PRIMARILY FROM SUNDAY NIGHT INTO MONDAY NIGHT
IN ASSOCIATION WITH A WEAK SURFACE LOW. THIS SNOW WILL BE WETTER IN
NATURE COMPARED TO RECENT EVENTS. SOME LAKE EFFECT SNOW SHOWERS
COULD FOLLOW FOR TUESDAY. RIGHT NOW IT SEEMS THAT A FEW INCHES OF
SNOW COULD FALL FOR THE EARLY PORTION OF NEXT WEEK.
THE SYSTEM OF INTEREST WILL NOT EVEN MAKE IT TO THE WESTERN U.S.
UNTIL THE WEEKEND...LEAVING SOME ROOM FOR ERROR IN THE FORECAST
TRACK UNTIL IT GETS BETTER SAMPLED BY THE UPPER AIR NETWORK AS WELL
AS AMDAR. NEVERTHELESS...DECENT AGREEMENT IS SHOWN BY THE
GFS/ECMWF/GEM IN BRINGING THE SUBTROPICAL JET INTO THE LOWER GREAT
LAKES REGION BY THE END OF THE WEEKEND. THE ECMWF IS THE FURTHEST
NORTH WITH THE JET AND HENCE THE SFC LOW THAT IS GENERATED IS SHOWN
TO TRACK ACROSS NORTHERN LOWER MI ON MONDAY. THE GFS AND GEM ARE
FURTHER SOUTH. EVEN SO...EITHER OF THESE SOLUTIONS SUPPORTS AN
INCREASED RISK FOR LIGHT SNOW TO IMPACT LOWER MI MAINLY MONDAY INTO
MONDAY NIGHT. OUR BLEND OF MEDIUM RANGE GUIDANCE SUPPORTS LESS THAN
A 50/50 SHOT AT THIS SNOW...BUT I THINK IT MAY BE UNDERDONE EVEN AT
THIS EARLY STAGE.
THE TRACK OF THE LOW (WEAK AS IT MAY BE) AND THE CORRESPONDING
THERMAL PROFILES WILL DETERMINE IF ANY RAIN MIXES IN WITH THE SNOW.
RIGHT NOW I AM NOT SEEING MUCH SUPPORT FOR LIQUID PRECIP...THOUGH IF
THE ECMWF TRENDS FURTHER NORTH THEN WE MAY HAVE TO INTRODUCE A
CHANCE FOR A RAIN/SNOW MIX ON MONDAY. ACCUMULATION WISE...THIS
SYSTEM COULD SUPPORT 1"-3" OF SNOW FOR OUR AREA IF TRENDS CONTINUE.
FOR TUESDAY...MODELS SUPPORT CYCLONIC FLOW AND H850 TEMPS FALLING
INTO THE -10C TO -14C RANGE ALONG WITH POTENTIALLY DEEP MOISTURE
REMAINING IN PLACE ON THE BACK SIDE OF THE LOW. THIS IS ESPECIALLY
TRUE WITH THE GFS SOLUTION. THUS THERE APPEARS TO BE AN INCREASING
RISK FOR LAKE EFFECT SNOW SHOWERS BY THAT TIME. WE WILL MONITOR
TRENDS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1243 PM EST WED JAN 20 2016
LIGHT SNOW WILL GRADUALLY DIMINISH AT MKG THIS AFTERNOON. SLIGHTLY
WARMER AND MORE MOIST AIR WILL MOVE ACROSS LOWER MICHIGAN TONIGHT
LEADING TO MVFR CIGS.
&&
.MARINE...
ISSUED AT 315 AM EST WED JAN 20 2016
WINDS/WAVE ACTION WILL REMAIN QUITE MINIMAL THROUGH FRIDAY AND
FAIRLY EXTENSIVE ICE BUILDUP CONTINUES TO DEVELOP OVER PORTIONS OF
THE NEARSHORE WATERS.
&&
.HYDROLOGY...
ISSUED AT 150 PM EST WED JAN 20 2016
ICE JAMS HAVE FORMED IN SPOTS ALONG SEVERAL RIVERS. A GENERAL RISE
IN RIVER LEVELS WITH OCCASIONAL DOWNWARD FLUCTUATIONS HAS BEEN
OCCURRING IN SPOTS SUCH AS IONIA... EAGLE... SMYRNA... AND
SCOTTVILLE. IONIA HAS SUPASSED BANKFULL THIS AFTERNOON AND THE
OTHER THREE ARE CONTENDERS THE NEXT FEW DAYS.
WITH BELOW-FREEZING WEATHER CONTINUING THROUGH THE REMAINDER OF
THE WEEK... LITTLE CHANGE IN THE ICE JAMS IS EXPECTED... AND
RIVER LEVELS SH0ULD REMAIN ELEVATED UPSTREAM OF THE JAMS.
SIGNIFICANT FLOODING IS NOT AN IMMEDIATE CONCERN. NEVERTHELESS...
ICE JAMS CAN CAUSE RELATIVELY RAPID CHANGES IN RIVER LEVELS
UPSTREAM AND DOWNSTREAM OF THE JAM WITH LITTLE ADVANCE NOTICE.
CONTINUE TO MONITOR FUTURE FORECASTS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR MIZ050-
056-064.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...LAURENS
SHORT TERM...LAURENS
LONG TERM...HOVING
AVIATION...04
HYDROLOGY...CAS
MARINE...LAURENS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1246 PM EST WED JAN 20 2016
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 315 AM EST WED JAN 20 2016
AN UPPER LEVEL DISTURBANCE WILL BRING MORE LIGHT SNOW TODAY.
TEMPERATURES WILL REMAIN SEASONABLY COLD TODAY BEFORE A GRADUAL
MODERATING TREND OF TEMPERATURES OCCURS LATE THIS WEEK. THE NEXT
CHANCE FOR ACCUMULATING SNOW WILL NOT COME UNTIL VERY LATE THIS
WEEKEND OR EARLY NEXT WEEK.
&&
.UPDATE...
ISSUED AT 1233 PM EST WED JAN 20 2016
THE MESO-SCALE HEAVY SNOW BAND AS MOVES SOMEWHAT TO THE SOUTH AND
IS NOW MOSTLY BETWEEN MUSKEGON AND GRAND HAVEN. DUAL POLE RADAR
SHOWS STORM TOTALS BETWEEN 3 TO 4 INCHES HAS FALLEN IN THAT AREA.
SINCE THE LATEST MODEL DATA SUGGESTS THE BAND WILL NOT START
MOVING ON SHORE UNTIL AROUND 3 PM... I EXTENDED THE ADVIOSRY TILL
4 PM.
UPDATE ISSUED AT 1102 AM EST WED JAN 20 2016
I PLAN TO KEEP OUR WINTER WEATHER ADVISORY GOING AS IS FOR NOW.
THE LATEST MODEL DATA SHOWS THE AREA OF STRONG MESO-SCALE FORCING
REMAINING LARGELY STATIONARY TILL 18Z. THE AREA THAT THETA-E
DECREASE WITH HEIGHT BETWEEN 1000 MB AND 925 MB IS RATHER NARROW
AND DOES NOT MOVE UNTIL AFTER 18Z. THE 88D RADAR SHOWS THE
STRONGEST RADAR RETURNS OVER THE AREA WITH THE GREATEST THETA-E
DECREASING WITH HEIGHT AND IN TURN THE GREATEST VERTICAL MOTION.
REPORTS SO FAR SHOW 1 TO 2 INCHES HAS FALLEN... I COULD SEE
ANOTHER INCH OR SO FALL THERE BEFORE THE BAND WEAKENS AND MOVES
EAST MID TO LATE AFTERNOON. ELSEWHERE EXPECT MOSTLY CLOUDY SKIES
WITH FLURRIES.
UPDATE ISSUED AT 551 AM EST WED JAN 20 2016
CURRENTLY CONSIDERING A WINTER STORM WARNING FOR MUSKEGON COUNTY
GIVEN CURRENT TRENDS:
A DOMINANT LAKE EFFECT BAND IS ONGOING AT THIS TIME ACROSS
SOUTHERN MUSKEGON COUNTY. HRRR SFC WIND FIELDS AND SIM REF
SUGGESTS THIS BAND MAY MIGRATE EAST SOMEWHAT OVER THE NEXT 3 TO 6
HOURS BUT LARGELY BE IMPACTING THE SAME AREAS...NAMELY GRAND HAVEN
TO WHITEHALL. LAND BASED OBS ARE SHOWING SSE WINDS ALONG THE COAST
WHILE WSW WINDS ARE COMING OFF THE LAKE. THIS WILL CONTINUE
CREATING LOW LEVEL CONVERGENCE AND MAY KEEP THIS MATURE BAND
GOING FOR SEVERAL HOURS. MOISTURE DEPTH STAYS AT OR ABOVE 10K FT
THROUGH 18Z. HRRR GUIDANCE SUGGESTS IT MAY NOT MOVE OUT OF THE
CURRENT AREA UNTIL 18Z OR SO. SNOWFALL RATES OF 1"-2" PER HOUR ARE
EXPECTED WITHIN THIS BAND WITH VISIBILITIES TO A QUARTER MILE OR
LESS AND POOR TRAVEL. ADDITIONAL SNOWFALL OF 3"-6" OR MORE COULD
EASILY BE ACHIEVED IN THE HARDEST HIT AREAS...FROM GRAND HAVEN TO
WHITEHALL.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 315 AM EST WED JAN 20 2016
LIGHT SNOW IS ANTICIPATED TODAY AS AN UPPER LEVEL SYSTEM MOVES
ACROSS LWR MI. MOST OF OUR FCST AREA WILL ONLY RECEIVE LESS THAN AN
INCH OF SNOW.
THE EXCEPTION TO THIS IS FROM ALLEGAN COUNTY NORTHWARD TO MKG
COUNTY WHERE SW FLOW LAKE ENHANCEMENT WILL OCCUR ALONG WITH SOME
ENHANCED LIFT. SNOW SHOULD GRADUALLY INCREASE IN COVERAGE AND
INTENSITY DURING THE EARLY TO MID MORNING HOURS THERE AS THE UPPER
TROF AXIS APPROACHES. 2 TO 4 INCHES OF SNOW IS ANTICIPATED ACROSS
PORTIONS OF THOSE COUNTIES WHERE THE WINTER WX ADVISORY REMAINS IN
EFFECT UNTIL 18Z THIS AFTN.
TRANQUIL WX IS ANTICIPATED TONIGHT THROUGH FRIDAY WITH JUST A FEW
LINGERING FLURRIES OR VERY LIGHT SNOW SHOWERS NEAR LAKE MI
TONIGHT. TEMPS WILL UNDERGO A GRADUAL MODERATING TREND AND REACH
THE MIDDLE 20S THURSDAY AND AROUND 30 DEGREES ON FRIDAY.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 315 AM EST WED JAN 20 2016
OUR MAIN FOCUS FOR THE EXTENDED FORECAST CONTINUES TO CENTER ON A
CHANCE FOR LIGHT SNOW PRIMARILY FROM SUNDAY NIGHT INTO MONDAY NIGHT
IN ASSOCIATION WITH A WEAK SURFACE LOW. THIS SNOW WILL BE WETTER IN
NATURE COMPARED TO RECENT EVENTS. SOME LAKE EFFECT SNOW SHOWERS
COULD FOLLOW FOR TUESDAY. RIGHT NOW IT SEEMS THAT A FEW INCHES OF
SNOW COULD FALL FOR THE EARLY PORTION OF NEXT WEEK.
THE SYSTEM OF INTEREST WILL NOT EVEN MAKE IT TO THE WESTERN U.S.
UNTIL THE WEEKEND...LEAVING SOME ROOM FOR ERROR IN THE FORECAST
TRACK UNTIL IT GETS BETTER SAMPLED BY THE UPPER AIR NETWORK AS WELL
AS AMDAR. NEVERTHELESS...DECENT AGREEMENT IS SHOWN BY THE
GFS/ECMWF/GEM IN BRINGING THE SUBTROPICAL JET INTO THE LOWER GREAT
LAKES REGION BY THE END OF THE WEEKEND. THE ECMWF IS THE FURTHEST
NORTH WITH THE JET AND HENCE THE SFC LOW THAT IS GENERATED IS SHOWN
TO TRACK ACROSS NORTHERN LOWER MI ON MONDAY. THE GFS AND GEM ARE
FURTHER SOUTH. EVEN SO...EITHER OF THESE SOLUTIONS SUPPORTS AN
INCREASED RISK FOR LIGHT SNOW TO IMPACT LOWER MI MAINLY MONDAY INTO
MONDAY NIGHT. OUR BLEND OF MEDIUM RANGE GUIDANCE SUPPORTS LESS THAN
A 50/50 SHOT AT THIS SNOW...BUT I THINK IT MAY BE UNDERDONE EVEN AT
THIS EARLY STAGE.
THE TRACK OF THE LOW (WEAK AS IT MAY BE) AND THE CORRESPONDING
THERMAL PROFILES WILL DETERMINE IF ANY RAIN MIXES IN WITH THE SNOW.
RIGHT NOW I AM NOT SEEING MUCH SUPPORT FOR LIQUID PRECIP...THOUGH IF
THE ECMWF TRENDS FURTHER NORTH THEN WE MAY HAVE TO INTRODUCE A
CHANCE FOR A RAIN/SNOW MIX ON MONDAY. ACCUMULATION WISE...THIS
SYSTEM COULD SUPPORT 1"-3" OF SNOW FOR OUR AREA IF TRENDS CONTINUE.
FOR TUESDAY...MODELS SUPPORT CYCLONIC FLOW AND H850 TEMPS FALLING
INTO THE -10C TO -14C RANGE ALONG WITH POTENTIALLY DEEP MOISTURE
REMAINING IN PLACE ON THE BACK SIDE OF THE LOW. THIS IS ESPECIALLY
TRUE WITH THE GFS SOLUTION. THUS THERE APPEARS TO BE AN INCREASING
RISK FOR LAKE EFFECT SNOW SHOWERS BY THAT TIME. WE WILL MONITOR
TRENDS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1243 PM EST WED JAN 20 2016
LIGHT SNOW WILL GRADUALLY DIMINISH AT MKG THIS AFTERNOON. SLIGHTLY
WARMER AND MORE MOIST AIR WILL MOVE ACROSS LOWER MICHIGAN TONIGHT
LEADING TO MVFR CIGS.
&&
.MARINE...
ISSUED AT 315 AM EST WED JAN 20 2016
WINDS/WAVE ACTION WILL REMAIN QUITE MINIMAL THROUGH FRIDAY AND
FAIRLY EXTENSIVE ICE BUILDUP CONTINUES TO DEVELOP OVER PORTIONS OF
THE NEARSHORE WATERS.
&&
.HYDROLOGY...
ISSUED AT 324 PM EST TUE JAN 19 2016
WIDESPREAD ICE FORMATION ON AREA RIVERS... WITH SOME ICE JAMMING...
HAS CAUSED RIVER LEVEL FLUCTUATIONS AT MANY SITES. THE GRAND RIVER
AT ROBINSON TOWNSHIP HAS DROPPED BELOW FLOOD STAGE AND THE ADVISORY
IS CANCELED. A FEW RIVERS ARE APPROACHING BANKFULL THIS AFTERNOON SO
WILL HAVE TO BE CLOSELY MONITORED. TEMPERATURES BELOW FREEZING THE
REST OF THIS WEEK SHOULD INCREASE ICE COVERAGE.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR MIZ050-
056-064.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...LAURENS
SHORT TERM...LAURENS
LONG TERM...HOVING
AVIATION...04
HYDROLOGY...WDM
MARINE...LAURENS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1237 PM EST WED JAN 20 2016
LATEST UPDATE...
UPDATE
.SYNOPSIS...
ISSUED AT 315 AM EST WED JAN 20 2016
AN UPPER LEVEL DISTURBANCE WILL BRING MORE LIGHT SNOW TODAY.
TEMPERATURES WILL REMAIN SEASONABLY COLD TODAY BEFORE A GRADUAL
MODERATING TREND OF TEMPERATURES OCCURS LATE THIS WEEK. THE NEXT
CHANCE FOR ACCUMULATING SNOW WILL NOT COME UNTIL VERY LATE THIS
WEEKEND OR EARLY NEXT WEEK.
&&
.UPDATE...
ISSUED AT 1233 PM EST WED JAN 20 2016
THE MESO-SCALE HEAVY SNOW BAND AS MOVES SOMEWHAT TO THE SOUTH AND
IS NOW MOSTLY BETWEEN MUSKEGON AND GRAND HAVEN. DUAL POLE RADAR
SHOWS STORM TOTALS BETWEEN 3 TO 4 INCHES HAS FALLEN IN THAT AREA.
SINCE THE LATEST MODEL DATA SUGGESTS THE BAND WILL NOT START
MOVING ON SHORE UNTIL AROUND 3 PM... I EXTENDED THE ADVIOSRY TILL
4 PM.
UPDATE ISSUED AT 1102 AM EST WED JAN 20 2016
I PLAN TO KEEP OUR WINTER WEATHER ADVISORY GOING AS IS FOR NOW.
THE LATEST MODEL DATA SHOWS THE AREA OF STRONG MESO-SCALE FORCING
REMAINING LARGELY STATIONARY TILL 18Z. THE AREA THAT THETA-E
DECREASE WITH HEIGHT BETWEEN 1000 MB AND 925 MB IS RATHER NARROW
AND DOES NOT MOVE UNTIL AFTER 18Z. THE 88D RADAR SHOWS THE
STRONGEST RADAR RETURNS OVER THE AREA WITH THE GREATEST THETA-E
DECREASING WITH HEIGHT AND IN TURN THE GREATEST VERTICAL MOTION.
REPORTS SO FAR SHOW 1 TO 2 INCHES HAS FALLEN... I COULD SEE
ANOTHER INCH OR SO FALL THERE BEFORE THE BAND WEAKENS AND MOVES
EAST MID TO LATE AFTERNOON. ELSEWHERE EXPECT MOSTLY CLOUDY SKIES
WITH FLURRIES.
UPDATE ISSUED AT 551 AM EST WED JAN 20 2016
CURRENTLY CONSIDERING A WINTER STORM WARNING FOR MUSKEGON COUNTY
GIVEN CURRENT TRENDS:
A DOMINANT LAKE EFFECT BAND IS ONGOING AT THIS TIME ACROSS
SOUTHERN MUSKEGON COUNTY. HRRR SFC WIND FIELDS AND SIM REF
SUGGESTS THIS BAND MAY MIGRATE EAST SOMEWHAT OVER THE NEXT 3 TO 6
HOURS BUT LARGELY BE IMPACTING THE SAME AREAS...NAMELY GRAND HAVEN
TO WHITEHALL. LAND BASED OBS ARE SHOWING SSE WINDS ALONG THE COAST
WHILE WSW WINDS ARE COMING OFF THE LAKE. THIS WILL CONTINUE
CREATING LOW LEVEL CONVERGENCE AND MAY KEEP THIS MATURE BAND
GOING FOR SEVERAL HOURS. MOISTURE DEPTH STAYS AT OR ABOVE 10K FT
THROUGH 18Z. HRRR GUIDANCE SUGGESTS IT MAY NOT MOVE OUT OF THE
CURRENT AREA UNTIL 18Z OR SO. SNOWFALL RATES OF 1"-2" PER HOUR ARE
EXPECTED WITHIN THIS BAND WITH VISIBILITIES TO A QUARTER MILE OR
LESS AND POOR TRAVEL. ADDITIONAL SNOWFALL OF 3"-6" OR MORE COULD
EASILY BE ACHIEVED IN THE HARDEST HIT AREAS...FROM GRAND HAVEN TO
WHITEHALL.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 315 AM EST WED JAN 20 2016
LIGHT SNOW IS ANTICIPATED TODAY AS AN UPPER LEVEL SYSTEM MOVES
ACROSS LWR MI. MOST OF OUR FCST AREA WILL ONLY RECEIVE LESS THAN AN
INCH OF SNOW.
THE EXCEPTION TO THIS IS FROM ALLEGAN COUNTY NORTHWARD TO MKG
COUNTY WHERE SW FLOW LAKE ENHANCEMENT WILL OCCUR ALONG WITH SOME
ENHANCED LIFT. SNOW SHOULD GRADUALLY INCREASE IN COVERAGE AND
INTENSITY DURING THE EARLY TO MID MORNING HOURS THERE AS THE UPPER
TROF AXIS APPROACHES. 2 TO 4 INCHES OF SNOW IS ANTICIPATED ACROSS
PORTIONS OF THOSE COUNTIES WHERE THE WINTER WX ADVISORY REMAINS IN
EFFECT UNTIL 18Z THIS AFTN.
TRANQUIL WX IS ANTICIPATED TONIGHT THROUGH FRIDAY WITH JUST A FEW
LINGERING FLURRIES OR VERY LIGHT SNOW SHOWERS NEAR LAKE MI
TONIGHT. TEMPS WILL UNDERGO A GRADUAL MODERATING TREND AND REACH
THE MIDDLE 20S THURSDAY AND AROUND 30 DEGREES ON FRIDAY.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 315 AM EST WED JAN 20 2016
OUR MAIN FOCUS FOR THE EXTENDED FORECAST CONTINUES TO CENTER ON A
CHANCE FOR LIGHT SNOW PRIMARILY FROM SUNDAY NIGHT INTO MONDAY NIGHT
IN ASSOCIATION WITH A WEAK SURFACE LOW. THIS SNOW WILL BE WETTER IN
NATURE COMPARED TO RECENT EVENTS. SOME LAKE EFFECT SNOW SHOWERS
COULD FOLLOW FOR TUESDAY. RIGHT NOW IT SEEMS THAT A FEW INCHES OF
SNOW COULD FALL FOR THE EARLY PORTION OF NEXT WEEK.
THE SYSTEM OF INTEREST WILL NOT EVEN MAKE IT TO THE WESTERN U.S.
UNTIL THE WEEKEND...LEAVING SOME ROOM FOR ERROR IN THE FORECAST
TRACK UNTIL IT GETS BETTER SAMPLED BY THE UPPER AIR NETWORK AS WELL
AS AMDAR. NEVERTHELESS...DECENT AGREEMENT IS SHOWN BY THE
GFS/ECMWF/GEM IN BRINGING THE SUBTROPICAL JET INTO THE LOWER GREAT
LAKES REGION BY THE END OF THE WEEKEND. THE ECMWF IS THE FURTHEST
NORTH WITH THE JET AND HENCE THE SFC LOW THAT IS GENERATED IS SHOWN
TO TRACK ACROSS NORTHERN LOWER MI ON MONDAY. THE GFS AND GEM ARE
FURTHER SOUTH. EVEN SO...EITHER OF THESE SOLUTIONS SUPPORTS AN
INCREASED RISK FOR LIGHT SNOW TO IMPACT LOWER MI MAINLY MONDAY INTO
MONDAY NIGHT. OUR BLEND OF MEDIUM RANGE GUIDANCE SUPPORTS LESS THAN
A 50/50 SHOT AT THIS SNOW...BUT I THINK IT MAY BE UNDERDONE EVEN AT
THIS EARLY STAGE.
THE TRACK OF THE LOW (WEAK AS IT MAY BE) AND THE CORRESPONDING
THERMAL PROFILES WILL DETERMINE IF ANY RAIN MIXES IN WITH THE SNOW.
RIGHT NOW I AM NOT SEEING MUCH SUPPORT FOR LIQUID PRECIP...THOUGH IF
THE ECMWF TRENDS FURTHER NORTH THEN WE MAY HAVE TO INTRODUCE A
CHANCE FOR A RAIN/SNOW MIX ON MONDAY. ACCUMULATION WISE...THIS
SYSTEM COULD SUPPORT 1"-3" OF SNOW FOR OUR AREA IF TRENDS CONTINUE.
FOR TUESDAY...MODELS SUPPORT CYCLONIC FLOW AND H850 TEMPS FALLING
INTO THE -10C TO -14C RANGE ALONG WITH POTENTIALLY DEEP MOISTURE
REMAINING IN PLACE ON THE BACK SIDE OF THE LOW. THIS IS ESPECIALLY
TRUE WITH THE GFS SOLUTION. THUS THERE APPEARS TO BE AN INCREASING
RISK FOR LAKE EFFECT SNOW SHOWERS BY THAT TIME. WE WILL MONITOR
TRENDS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1156 PM EST TUE JAN 19 2016
SNOW WILL BE ON THE INCREASE OVERNIGHT WITH WIDESPREAD IFR
CONDITIONS DEVELOPING BY 12Z WEDNESDAY. EXPECT IFR AND SOME AREAS
OF LIFR WEDNESDAY MORNING WITH CONDITIONS SLOWLY IMPROVING TO
MVFR DURING THE AFTERNOON. WINDS WILL WEST SOUTHWEST AOB 10
KNOTS.
&&
.MARINE...
ISSUED AT 315 AM EST WED JAN 20 2016
WINDS/WAVE ACTION WILL REMAIN QUITE MINIMAL THROUGH FRIDAY AND
FAIRLY EXTENSIVE ICE BUILDUP CONTINUES TO DEVELOP OVER PORTIONS OF
THE NEARSHORE WATERS.
&&
.HYDROLOGY...
ISSUED AT 324 PM EST TUE JAN 19 2016
WIDESPREAD ICE FORMATION ON AREA RIVERS... WITH SOME ICE JAMMING...
HAS CAUSED RIVER LEVEL FLUCTUATIONS AT MANY SITES. THE GRAND RIVER
AT ROBINSON TOWNSHIP HAS DROPPED BELOW FLOOD STAGE AND THE ADVISORY
IS CANCELED. A FEW RIVERS ARE APPROACHING BANKFULL THIS AFTERNOON SO
WILL HAVE TO BE CLOSELY MONITORED. TEMPERATURES BELOW FREEZING THE
REST OF THIS WEEK SHOULD INCREASE ICE COVERAGE.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR MIZ050-
056-064.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...LAURENS
SHORT TERM...LAURENS
LONG TERM...HOVING
AVIATION...OSTUNO
HYDROLOGY...WDM
MARINE...LAURENS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1102 AM EST WED JAN 20 2016
LATEST UPDATE...
UPDATE
.SYNOPSIS...
ISSUED AT 315 AM EST WED JAN 20 2016
AN UPPER LEVEL DISTURBANCE WILL BRING MORE LIGHT SNOW TODAY.
TEMPERATURES WILL REMAIN SEASONABLY COLD TODAY BEFORE A GRADUAL
MODERATING TREND OF TEMPERATURES OCCURS LATE THIS WEEK. THE NEXT
CHANCE FOR ACCUMULATING SNOW WILL NOT COME UNTIL VERY LATE THIS
WEEKEND OR EARLY NEXT WEEK.
&&
.UPDATE...
ISSUED AT 1102 AM EST WED JAN 20 2016
I PLAN TO KEEP OUR WINTER WEATHER ADVISORY GOING AS IS FOR NOW.
THE LATEST MODEL DATA SHOWS THE AREA OF STRONG MESO-SCALE FORCING
REMAINING LARGELY STATIONARY TILL 18Z. THE AREA THAT THETA-E
DECREASE WITH HEIGHT BETWEEN 1000 MB AND 925 MB IS RATHER NARROW
AND DOES NOT MOVE UNTIL AFTER 18Z. THE 88D RADAR SHOWS THE
STRONGEST RADAR RETURNS OVER THE AREA WITH THE GREATEST THETA-E
DECREASING WITH HEIGHT AND IN TURN THE GREATEST VERTICAL MOTION.
REPORTS SO FAR SHOW 1 TO 2 INCHES HAS FALLEN... I COULD SEE
ANOTHER INCH OR SO FALL THERE BEFORE THE BAND WEAKENS AND MOVES
EAST MID TO LATE AFTERNOON. ELSEWHERE EXPECT MOSTLY CLOUDY SKIES
WITH FLURRIES.
UPDATE ISSUED AT 551 AM EST WED JAN 20 2016
CURRENTLY CONSIDERING A WINTER STORM WARNING FOR MUSKEGON COUNTY
GIVEN CURRENT TRENDS:
A DOMINANT LAKE EFFECT BAND IS ONGOING AT THIS TIME ACROSS
SOUTHERN MUSKEGON COUNTY. HRRR SFC WIND FIELDS AND SIM REF
SUGGESTS THIS BAND MAY MIGRATE EAST SOMEWHAT OVER THE NEXT 3 TO 6
HOURS BUT LARGELY BE IMPACTING THE SAME AREAS...NAMELY GRAND HAVEN
TO WHITEHALL. LAND BASED OBS ARE SHOWING SSE WINDS ALONG THE COAST
WHILE WSW WINDS ARE COMING OFF THE LAKE. THIS WILL CONTINUE
CREATING LOW LEVEL CONVERGENCE AND MAY KEEP THIS MATURE BAND
GOING FOR SEVERAL HOURS. MOISTURE DEPTH STAYS AT OR ABOVE 10K FT
THROUGH 18Z. HRRR GUIDANCE SUGGESTS IT MAY NOT MOVE OUT OF THE
CURRENT AREA UNTIL 18Z OR SO. SNOWFALL RATES OF 1"-2" PER HOUR ARE
EXPECTED WITHIN THIS BAND WITH VISIBILITIES TO A QUARTER MILE OR
LESS AND POOR TRAVEL. ADDITIONAL SNOWFALL OF 3"-6" OR MORE COULD
EASILY BE ACHIEVED IN THE HARDEST HIT AREAS...FROM GRAND HAVEN TO
WHITEHALL.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 315 AM EST WED JAN 20 2016
LIGHT SNOW IS ANTICIPATED TODAY AS AN UPPER LEVEL SYSTEM MOVES
ACROSS LWR MI. MOST OF OUR FCST AREA WILL ONLY RECEIVE LESS THAN AN
INCH OF SNOW.
THE EXCEPTION TO THIS IS FROM ALLEGAN COUNTY NORTHWARD TO MKG
COUNTY WHERE SW FLOW LAKE ENHANCEMENT WILL OCCUR ALONG WITH SOME
ENHANCED LIFT. SNOW SHOULD GRADUALLY INCREASE IN COVERAGE AND
INTENSITY DURING THE EARLY TO MID MORNING HOURS THERE AS THE UPPER
TROF AXIS APPROACHES. 2 TO 4 INCHES OF SNOW IS ANTICIPATED ACROSS
PORTIONS OF THOSE COUNTIES WHERE THE WINTER WX ADVISORY REMAINS IN
EFFECT UNTIL 18Z THIS AFTN.
TRANQUIL WX IS ANTICIPATED TONIGHT THROUGH FRIDAY WITH JUST A FEW
LINGERING FLURRIES OR VERY LIGHT SNOW SHOWERS NEAR LAKE MI
TONIGHT. TEMPS WILL UNDERGO A GRADUAL MODERATING TREND AND REACH
THE MIDDLE 20S THURSDAY AND AROUND 30 DEGREES ON FRIDAY.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 315 AM EST WED JAN 20 2016
OUR MAIN FOCUS FOR THE EXTENDED FORECAST CONTINUES TO CENTER ON A
CHANCE FOR LIGHT SNOW PRIMARILY FROM SUNDAY NIGHT INTO MONDAY NIGHT
IN ASSOCIATION WITH A WEAK SURFACE LOW. THIS SNOW WILL BE WETTER IN
NATURE COMPARED TO RECENT EVENTS. SOME LAKE EFFECT SNOW SHOWERS
COULD FOLLOW FOR TUESDAY. RIGHT NOW IT SEEMS THAT A FEW INCHES OF
SNOW COULD FALL FOR THE EARLY PORTION OF NEXT WEEK.
THE SYSTEM OF INTEREST WILL NOT EVEN MAKE IT TO THE WESTERN U.S.
UNTIL THE WEEKEND...LEAVING SOME ROOM FOR ERROR IN THE FORECAST
TRACK UNTIL IT GETS BETTER SAMPLED BY THE UPPER AIR NETWORK AS WELL
AS AMDAR. NEVERTHELESS...DECENT AGREEMENT IS SHOWN BY THE
GFS/ECMWF/GEM IN BRINGING THE SUBTROPICAL JET INTO THE LOWER GREAT
LAKES REGION BY THE END OF THE WEEKEND. THE ECMWF IS THE FURTHEST
NORTH WITH THE JET AND HENCE THE SFC LOW THAT IS GENERATED IS SHOWN
TO TRACK ACROSS NORTHERN LOWER MI ON MONDAY. THE GFS AND GEM ARE
FURTHER SOUTH. EVEN SO...EITHER OF THESE SOLUTIONS SUPPORTS AN
INCREASED RISK FOR LIGHT SNOW TO IMPACT LOWER MI MAINLY MONDAY INTO
MONDAY NIGHT. OUR BLEND OF MEDIUM RANGE GUIDANCE SUPPORTS LESS THAN
A 50/50 SHOT AT THIS SNOW...BUT I THINK IT MAY BE UNDERDONE EVEN AT
THIS EARLY STAGE.
THE TRACK OF THE LOW (WEAK AS IT MAY BE) AND THE CORRESPONDING
THERMAL PROFILES WILL DETERMINE IF ANY RAIN MIXES IN WITH THE SNOW.
RIGHT NOW I AM NOT SEEING MUCH SUPPORT FOR LIQUID PRECIP...THOUGH IF
THE ECMWF TRENDS FURTHER NORTH THEN WE MAY HAVE TO INTRODUCE A
CHANCE FOR A RAIN/SNOW MIX ON MONDAY. ACCUMULATION WISE...THIS
SYSTEM COULD SUPPORT 1"-3" OF SNOW FOR OUR AREA IF TRENDS CONTINUE.
FOR TUESDAY...MODELS SUPPORT CYCLONIC FLOW AND H850 TEMPS FALLING
INTO THE -10C TO -14C RANGE ALONG WITH POTENTIALLY DEEP MOISTURE
REMAINING IN PLACE ON THE BACK SIDE OF THE LOW. THIS IS ESPECIALLY
TRUE WITH THE GFS SOLUTION. THUS THERE APPEARS TO BE AN INCREASING
RISK FOR LAKE EFFECT SNOW SHOWERS BY THAT TIME. WE WILL MONITOR
TRENDS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1156 PM EST TUE JAN 19 2016
SNOW WILL BE ON THE INCREASE OVERNIGHT WITH WIDESPREAD IFR
CONDITIONS DEVELOPING BY 12Z WEDNESDAY. EXPECT IFR AND SOME AREAS
OF LIFR WEDNESDAY MORNING WITH CONDITIONS SLOWLY IMPROVING TO
MVFR DURING THE AFTERNOON. WINDS WILL WEST SOUTHWEST AOB 10
KNOTS.
&&
.MARINE...
ISSUED AT 315 AM EST WED JAN 20 2016
WINDS/WAVE ACTION WILL REMAIN QUITE MINIMAL THROUGH FRIDAY AND
FAIRLY EXTENSIVE ICE BUILDUP CONTINUES TO DEVELOP OVER PORTIONS OF
THE NEARSHORE WATERS.
&&
.HYDROLOGY...
ISSUED AT 324 PM EST TUE JAN 19 2016
WIDESPREAD ICE FORMATION ON AREA RIVERS... WITH SOME ICE JAMMING...
HAS CAUSED RIVER LEVEL FLUCTUATIONS AT MANY SITES. THE GRAND RIVER
AT ROBINSON TOWNSHIP HAS DROPPED BELOW FLOOD STAGE AND THE ADVISORY
IS CANCELED. A FEW RIVERS ARE APPROACHING BANKFULL THIS AFTERNOON SO
WILL HAVE TO BE CLOSELY MONITORED. TEMPERATURES BELOW FREEZING THE
REST OF THIS WEEK SHOULD INCREASE ICE COVERAGE.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR MIZ050-
056-064.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...LAURENS
SHORT TERM...LAURENS
LONG TERM...HOVING
AVIATION...OSTUNO
HYDROLOGY...WDM
MARINE...LAURENS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
603 AM EST WED JAN 20 2016
LATEST UPDATE...
UPDATE
.SYNOPSIS...
ISSUED AT 315 AM EST WED JAN 20 2016
AN UPPER LEVEL DISTURBANCE WILL BRING MORE LIGHT SNOW TODAY.
TEMPERATURES WILL REMAIN SEASONABLY COLD TODAY BEFORE A GRADUAL
MODERATING TREND OF TEMPERATURES OCCURS LATE THIS WEEK. THE NEXT
CHANCE FOR ACCUMULATING SNOW WILL NOT COME UNTIL VERY LATE THIS
WEEKEND OR EARLY NEXT WEEK.
&&
.UPDATE...
ISSUED AT 551 AM EST WED JAN 20 2016
CURRENTLY CONSIDERING A WINTER STORM WARNING FOR MUSKEGON COUNTY
GIVEN CURRENT TRENDS:
A DOMINANT LAKE EFFECT BAND IS ONGOING AT THIS TIME ACROSS
SOUTHERN MUSKEGON COUNTY. HRRR SFC WIND FIELDS AND SIM REF
SUGGESTS THIS BAND MAY MIGRATE EAST SOMEWHAT OVER THE NEXT 3 TO 6
HOURS BUT LARGELY BE IMPACTING THE SAME AREAS...NAMELY GRAND HAVEN
TO WHITEHALL. LAND BASED OBS ARE SHOWING SSE WINDS ALONG THE COAST
WHILE WSW WINDS ARE COMING OFF THE LAKE. THIS WILL CONTINUE
CREATING LOW LEVEL CONVERGENCE AND MAY KEEP THIS MATURE BAND
GOING FOR SEVERAL HOURS. MOISTURE DEPTH STAYS AT OR ABOVE 10K FT
THROUGH 18Z. HRRR GUIDANCE SUGGESTS IT MAY NOT MOVE OUT OF THE
CURRENT AREA UNTIL 18Z OR SO. SNOWFALL RATES OF 1"-2" PER HOUR ARE
EXPECTED WITHIN THIS BAND WITH VISIBILITIES TO A QUARTER MILE OR
LESS AND POOR TRAVEL. ADDITIONAL SNOWFALL OF 3"-6" OR MORE COULD
EASILY BE ACHIEVED IN THE HARDEST HIT AREAS...FROM GRAND HAVEN TO
WHITEHALL.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 315 AM EST WED JAN 20 2016
LIGHT SNOW IS ANTICIPATED TODAY AS AN UPPER LEVEL SYSTEM MOVES
ACROSS LWR MI. MOST OF OUR FCST AREA WILL ONLY RECEIVE LESS THAN AN
INCH OF SNOW.
THE EXCEPTION TO THIS IS FROM ALLEGAN COUNTY NORTHWARD TO MKG
COUNTY WHERE SW FLOW LAKE ENHANCEMENT WILL OCCUR ALONG WITH SOME
ENHANCED LIFT. SNOW SHOULD GRADUALLY INCREASE IN COVERAGE AND
INTENSITY DURING THE EARLY TO MID MORNING HOURS THERE AS THE UPPER
TROF AXIS APPROACHES. 2 TO 4 INCHES OF SNOW IS ANTICIPATED ACROSS
PORTIONS OF THOSE COUNTIES WHERE THE WINTER WX ADVISORY REMAINS IN
EFFECT UNTIL 18Z THIS AFTN.
TRANQUIL WX IS ANTICIPATED TONIGHT THROUGH FRIDAY WITH JUST A FEW
LINGERING FLURRIES OR VERY LIGHT SNOW SHOWERS NEAR LAKE MI
TONIGHT. TEMPS WILL UNDERGO A GRADUAL MODERATING TREND AND REACH
THE MIDDLE 20S THURSDAY AND AROUND 30 DEGREES ON FRIDAY.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 315 AM EST WED JAN 20 2016
OUR MAIN FOCUS FOR THE EXTENDED FORECAST CONTINUES TO CENTER ON A
CHANCE FOR LIGHT SNOW PRIMARILY FROM SUNDAY NIGHT INTO MONDAY NIGHT
IN ASSOCIATION WITH A WEAK SURFACE LOW. THIS SNOW WILL BE WETTER IN
NATURE COMPARED TO RECENT EVENTS. SOME LAKE EFFECT SNOW SHOWERS
COULD FOLLOW FOR TUESDAY. RIGHT NOW IT SEEMS THAT A FEW INCHES OF
SNOW COULD FALL FOR THE EARLY PORTION OF NEXT WEEK.
THE SYSTEM OF INTEREST WILL NOT EVEN MAKE IT TO THE WESTERN U.S.
UNTIL THE WEEKEND...LEAVING SOME ROOM FOR ERROR IN THE FORECAST
TRACK UNTIL IT GETS BETTER SAMPLED BY THE UPPER AIR NETWORK AS WELL
AS AMDAR. NEVERTHELESS...DECENT AGREEMENT IS SHOWN BY THE
GFS/ECMWF/GEM IN BRINGING THE SUBTROPICAL JET INTO THE LOWER GREAT
LAKES REGION BY THE END OF THE WEEKEND. THE ECMWF IS THE FURTHEST
NORTH WITH THE JET AND HENCE THE SFC LOW THAT IS GENERATED IS SHOWN
TO TRACK ACROSS NORTHERN LOWER MI ON MONDAY. THE GFS AND GEM ARE
FURTHER SOUTH. EVEN SO...EITHER OF THESE SOLUTIONS SUPPORTS AN
INCREASED RISK FOR LIGHT SNOW TO IMPACT LOWER MI MAINLY MONDAY INTO
MONDAY NIGHT. OUR BLEND OF MEDIUM RANGE GUIDANCE SUPPORTS LESS THAN
A 50/50 SHOT AT THIS SNOW...BUT I THINK IT MAY BE UNDERDONE EVEN AT
THIS EARLY STAGE.
THE TRACK OF THE LOW (WEAK AS IT MAY BE) AND THE CORRESPONDING
THERMAL PROFILES WILL DETERMINE IF ANY RAIN MIXES IN WITH THE SNOW.
RIGHT NOW I AM NOT SEEING MUCH SUPPORT FOR LIQUID PRECIP...THOUGH IF
THE ECMWF TRENDS FURTHER NORTH THEN WE MAY HAVE TO INTRODUCE A
CHANCE FOR A RAIN/SNOW MIX ON MONDAY. ACCUMULATION WISE...THIS
SYSTEM COULD SUPPORT 1"-3" OF SNOW FOR OUR AREA IF TRENDS CONTINUE.
FOR TUESDAY...MODELS SUPPORT CYCLONIC FLOW AND H850 TEMPS FALLING
INTO THE -10C TO -14C RANGE ALONG WITH POTENTIALLY DEEP MOISTURE
REMAINING IN PLACE ON THE BACK SIDE OF THE LOW. THIS IS ESPECIALLY
TRUE WITH THE GFS SOLUTION. THUS THERE APPEARS TO BE AN INCREASING
RISK FOR LAKE EFFECT SNOW SHOWERS BY THAT TIME. WE WILL MONITOR
TRENDS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1156 PM EST TUE JAN 19 2016
SNOW WILL BE ON THE INCREASE OVERNIGHT WITH WIDESPREAD IFR
CONDITIONS DEVELOPING BY 12Z WEDNESDAY. EXPECT IFR AND SOME AREAS
OF LIFR WEDNESDAY MORNING WITH CONDITIONS SLOWLY IMPROVING TO
MVFR DURING THE AFTERNOON. WINDS WILL WEST SOUTHWEST AOB 10
KNOTS.
&&
.MARINE...
ISSUED AT 315 AM EST WED JAN 20 2016
WINDS/WAVE ACTION WILL REMAIN QUITE MINIMAL THROUGH FRIDAY AND
FAIRLY EXTENSIVE ICE BUILDUP CONTINUES TO DEVELOP OVER PORTIONS OF
THE NEARSHORE WATERS.
&&
.HYDROLOGY...
ISSUED AT 324 PM EST TUE JAN 19 2016
WIDESPREAD ICE FORMATION ON AREA RIVERS... WITH SOME ICE JAMMING...
HAS CAUSED RIVER LEVEL FLUCTUATIONS AT MANY SITES. THE GRAND RIVER
AT ROBINSON TOWNSHIP HAS DROPPED BELOW FLOOD STAGE AND THE ADVISORY
IS CANCELED. A FEW RIVERS ARE APPROACHING BANKFULL THIS AFTERNOON SO
WILL HAVE TO BE CLOSELY MONITORED. TEMPERATURES BELOW FREEZING THE
REST OF THIS WEEK SHOULD INCREASE ICE COVERAGE.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR MIZ050-
056-064.
LM...NONE.
&&
$$
UPDATE...HOVING
SYNOPSIS...LAURENS
SHORT TERM...LAURENS
LONG TERM...HOVING
AVIATION...OSTUNO
HYDROLOGY...WDM
MARINE...LAURENS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1203 AM EST WED JAN 20 2016
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 354 PM EST TUE JAN 19 2016
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW SHRTWV RDG
STRETCHING FM NW ONTARIO IN MN WITHIN NW FLOW ALF ON WRN FLANK OF
DEPARTING UPR LO OVER SE CANADA. ASSOCIATED SFC HI PRES RDG
STRETCHES FM NW ONTARIO THRU THE UPR MS RIVER VALLEY AND TOWARD THE
OH RIVER VALLEY. NW FLOW OF COLD AIR...WITH H925 TEMPS ARND -15C
OVER THE UPR LKS...IN ADVANCE OF THIS SLOWLY APRCHG RDG IS STILL
CAUSING SOME LES...BUT BANDS ARE WEAKER/MORE DISORGANIZED WITH
STRONG SUBSIDENCE ASSOCIATED WITH THE APRCHG RDG LOWERING INVRN BASE
TOWARD 3-4K FT AGL PER MQT VWP. LLVL WINDS ARE BEGINNING TO BACK AS
WELL AHEAD OF THE APRCHG SFC RDG...SO BANDS ARE SHIFTING/LIMITING
RESIDENCE TIME. PLENTY OF LO CLDS LINGER UNDER THE LOWERING INVRN
DESPITE DRY NATURE OF THE NEAR SFC LYR UPSTREAM /WHERE SFC DEWPTS
ARE AOB -20F OVER MUCH OF NRN MN...BUT SOME BREAKS ARE BEGINNING TO
SHOW UP OVER THE FAR W NEAR IWD CLOSER TO THE INCOMING SFC HI PRES/
DRY LLVL AIR AND OVER THE SCENTRL WHERE NW FLOW IS DOWNSLOPING.
THERE IS ANOTHER SHRTWV STRETCHING FM SASKATCHEWAN INTO THE NRN
PLAINS THAT IS DIGGING SEWD...AND SOME HI/MID CLDS AHEAD OF THIS
DISTURBANCE ARE SPREADING INTO MN.
MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON LINGERING LES TRENDS/
LO CLDS AND IMPACT ON TEMPS.
TNGT...SFC HI PRES RDG AXIS IS FCST TO SHIFT SLOWLY TO THE E AND
STRETCH FM THE UPR OH VALLEY INTO UPR MI AT 12Z WED. AS THE LLVL
WINDS CONTINUE TO BACK TOWARD THE WSW...ANY LINGERING SN SHOWERS
OVER THE NRN KEWEENAW AND NEAR LK SUP E OF GRAND MARAIS SHOULD LIFT
OUT INTO LK SUP. SINCE THE WINDS WL SHIFT OFFSHORE AND THE INVRN
BASE WL LOWER WITH MORE ACYC LLVL FLOW...EXPECT THE BULK OF THE LO
CLDS TO SHIFT OVER THE LK AS WELL. ALTHOUGH THE SETUP SEEMS
FAVORABLE FOR VERY LO TEMPS WITH LGT OFFSHORE WINDS...MID/HI CLDS ON
THE NRN FRINGES OF SHRTWV DIGGING TO THE SE ARE FCST TO MOVE OVER
THE CWA AND LIMIT THE DIURNAL TEMP FALL. SO ALTHOUGH THERE MAY BE
SOME SUB ZERO MIN TEMPS OVER THE INTERIOR...WIDESPREAD MIN TEMPS
UNDER -10F AS OBSVD THIS MRNG OVER NRN MN ARE NOT LIKELY.
WED...LARGE SCALE QVECTOR DVGC AHEAD OF SHRTWV RDG AND UNDER SFC RDG
AXIS WL MAINTAIN MAINLY DRY WX FOR MOST OF THE CWA...WITH ANY SN
SHOWERS OVER LK SUP NEAR LK INDUCED TROF FCST TO LINGER OVER THE N
HALF OF THE LK. DURING THE DAY...MANY OF THE MODELS SHOW SOME MSTR
RETURN OVER MAINLY THE WRN CWA IN THE SW FLOW BTWN THE SFC RDG
SHIFTING SLOWLY TO THE E AND A SHRTWV APRCHG LATE IN THE DAY FM THE
NW. BUT SINCE ANY FORCING AND LLVL MSTR INFLOW WL BE MINIMAL...OPTED
TO RETAIN ONLY SCHC POPS OVER THE WRN CWA WHERE THE MOISTENING IS
FCST TO BE A BIT MORE ROBUST. EXPECT A SOMEWHAT WARMER AFTN WITH H85
TEMPS REBOUNDING TO ARND -12C BY 00Z THU.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 446 PM EST TUE JAN 19 2016
BY 00Z THURSDAY THE SFC HIGH WILL HAVE SLIPPED TO IL-OH...WITH A
WEAK RIDGE/LAKE INDUCED LOW SLOWLY DEEPENING ACROSS LAKE SUPERIOR AS
THE RIDGE EXITS. THE NEXT IN A SERIES OF SHORTWAVES WILL ASSIST IN
THE LIGHT SNOW SHOWER POTENTIAL WEDNESDAY NIGHT...TRACKING FROM SW
ONTARIO AT 00Z TO FAR N LAKE HURON BY DAYBREAK THURSDAY. THE MAIN
IMPACT WILL BE TO INCREASE NW FLOW ACROSS THE KEWEENAW PENINSULA
BEHIND THE WEAK SFC-500MB TROUGH AND ENHANCING LIGHT SNOW SHOWERS
THERE. 850MB TEMPS WILL BE AROUND -11C. NOT EXPECTING ADVISORY
SNOW AMOUNTS AT THIS TIME.
THE NEXT SFC HIGH SITUATED OVER MANITOBA AND N DAKOTA THURSDAY WILL
PUSH ACROSS MN AND W LAKE SUPERIOR ON FRIDAY...BUT WILL ONLY SLOWLY
BREAK DOWN THE LINGERING WEAK TROUGH OVER E LAKE SUPERIOR/E UPPER MI
BY FRIDAY NIGHT. SFC WINDS WILL SHIFT OUT OF THE N THURSDAY NIGHT
THROUGH FRIDAY AND 850MB TEMPS WILL FALL TO -12 TO -14C...BUT WITH
LIMITED MOISTURE...EXPECT SNOWFALL LESS THAN 2IN.
ANOTHER DRY PERIOD IS EXPECTED FRIDAY NIGHT THROUGH SATURDAY NIGHT
AS ANOTHER AREA OF HIGH PRESSURE SHIFTS ACROSS THE REGION. BY
SATURDAY MORNING ...THE NEXT LOW WILL BET SET UP ACROSS S CENTRAL
CANADA WHILE MUCH OF THE ATTENTION WILL BE ON THE TRACK AND TIMING
OF THE LOW OFF THE MID ATLANTIC COAST. UPPER MI WILL REMAIN IN
BETWEEN SYSTEMS UNTIL THE CANADIAN LOW SHIFTS ACROSS ONTARIO SUNDAY
AND THE EASTERN LOW MOVES OFF THE NEW ENGLAND STATES. THE TROUGH
LOOKS TO CROSS UPPER MI LATE SUNDAY NIGHT/MONDAY MORNING. THE GFS
AND ECMWF ARE OVER 12HRS ON TIMING WHEN THE NEXT SWATH OF SNOW WILL
CROSS UPPER MI SUNDAY AFTERNOON-MONDAY...WITH DIFFERENCES IN THE
TIMING OF THE NEXT LONGWAVE TROUGH MOVING ACROSS THE CENTRAL PLAINS
AND GREAT LAKES STATES. MODERATE TO HIGH CONFIDENCE EXISTS IN THE
ONGOING FORECAST FOR UPPER MI UNTIL SUNDAY. OTHERWISE THE CONSENSUS
FOR MONDAY-TUESDAY WOULD BE FOR AT LEAST SOME COOLER WITH 850MB
TEMPS FALLING AGAIN TO -10 TO -12C.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1203 AM EST WED JAN 20 2016
VFR CONDITIONS WILL CONTINUE THROUGH THE PERIOD AT SAW. LAKE EFFECT
MVFR DECK AT CMX WILL GO AWAY WITH SW WINDS KEEPING THEM
OFFSHORE...THEN MVFR CONDITIONS RETURN BY LATE WED EVENING. AT
IWD...VFR CONDITIONS WILL CONTINUE THROUGH MOST OF THE PERIOD. THERE
WILL BE TIMES WHEN HIGH END MVFR DECK COMES INTO IWD WED MORNING AND
AGAIN WED AFTERNOON.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 354 PM EST TUE JAN 19 2016
WITH A RELATIVELY WEAK PRES GRADIENT EXPECTED OVER THE UPPER LAKES
MOST OF THIS COMING FORECAST PERIOD...WINDS WILL REMAIN UNDER 25 KTS
MOST OF THE TIME. THE BEST CHANCE FOR SW WINDS UP TO 30 KTS WILL BE
ON SAT...WHEN A SHARPER GRADIENT BETWEEN HI PRES STRETCHING FROM NEW
ENGLAND INTO THE MID MS RIVER VALLEY AND A LO PRES TROF APPROACHING
FROM THE NW MAY SUPPORT THE STRONGER WINDS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...07
MARINE...KC
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
922 PM CST THU JAN 21 2016
.UPDATE:
Issued at 902 PM CST Thu Jan 21 2016
The radar continued to depict very low reflectivities over
central MO this evening ahead of an upper level low over western
MO. So far no precipitation was being reported at the ground, but
could not rule out a brief period of flurries from the mid level
cloudiness this evening. Surface low over southern MS will move
northeastward into northern AL by 12Z Friday. Models do bring
precipitation shield north-northeastward overnight, but it
appears that the precipitation will remain south-southeast of our
forecast area. Could not rule out very light snow or flurries late
tonight across the extreme southern/southeastern portion of our
forecast area with no accumulation expected. With cloud cover lows
tonight should be at least a little warmer than the previous night
over most of the region.
GKS
&&
.SHORT TERM: (Through Friday)
Issued at 240 PM CST Thu Jan 21 2016
Deep trof with two very distinct vortices is continuing to dig
across the eastern Plains. The northern vortex is over eastern
Kansas producing some light snow...while the southern vortex is
moving along the Oklahoma Texas border. Our CWFA is on the
fringes of influence of both of these vortices, and dry low level
air is being pulled from the east-northeast across the area as the
surface reflection of the trof deepens over Louisiana. This dry
low level flow more or less evaporated much of our precip this
morning, and it will continue to keep us dry tonight into Friday.
Most short range guidance is in agreement that accumulating precip
will stay south and east of the area through Friday...with the
notable exception of the HRRR which does show some light snow
overnight across our southern counties. Kept some low chance PoPs
in southern zones to cover this eventuality. Temperatures in the
column should be cold enough for snow...if anything should fall.
Should see temperatures continue to moderate with lows tonight
generally in the upper teens and highs Friday in the low 30s. We
might even break through the freezing mark across our southern
zones.
Carney
.LONG TERM: (Saturday through Next Thursday)
Issued at 240 PM CST Thu Jan 21 2016
(Saturday and Sunday)
Focus will be temps with sfc ridge building into the region thru the
weekend.
With the sfc ridge building into the area Fri night, expect clouds
to gradually clear with system pulling newd out of the region. Winds
will gradually diminish, but perhaps more slowly. These two
features will have a large impact on temps overnight and will likely
end up with a large temp spread across the CWA. Given how quickly
temps can drop as winds become light and with potentially some snow
left, have trended twd the cooler guidance.
With upper level ridging and strong swly low level winds building
the thermal ridge into the region thru the later half of the
weekend, have trended twd the warmer guidance. Going forecast for
Sun may still be too cool. However, one concern is that sfc winds
may be more sely than sly or swly.
(Monday through Thursday)
Focus turns to system approaching the CWA on Mon. Mdls have come
into very good agreement regarding mass fields for this system. Some
timing differences still exist, but are in remarkably good agreement
for day 5. With the better agreement, have begun to fine tune the p-
types for this system. Given thermal profiles, believe this will be
mainly a light RA event. Cold air will move in behind the system Mon
afternoon into Mon night. There is a fair amount of uncertainty in
how quickly this will occur. Have therefore kept mention of RA thru
Mon, but trended twd a RA to mix to SN for Mon night.
With low level wly flow late in the period, have moderated temps for
now. Some timing differences on the next s/w to approach the region
into Thurs. Little if any precip is anticipated, but timing of this
trof may impact temps.
Tilly
&&
.AVIATION: (For the 00z TAFs through 00z Friday Evening)
Issued at 535 PM CST Thu Jan 21 2016
VFR flight conditions are expected tonight with extensive mid-high
clouds, with surface winds increasing some overnight and into
Friday morning. Will need to keep an eye on potential for LLWS
overnight as the low level winds in the lowest 2-3 km increase in
response to the deepening storm system to our south. Stratus currently
located across the Upper MS Valley and Great Lakes will advect
southward into the region on Friday bringing MVFR flight conditions.
Specifics for KSTL:
VFR flight conditions are expected tonight into early Friday
afternoon with extensive mid-high clouds. A deepening storm system
to our south will also produce increasing northerly surface winds.
Will need to keep an eye on potential for LLWS overnight as the
low level winds in the lowest 2-3 km increase, but present indications
are they will remain just above thresholds. Stratus currently
located across the Upper MS Valley and Great Lakes will advect
southward into the terminal Friday afternoon bringing MVFR flight
conditions.
Glass
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
552 PM CST THU JAN 21 2016
.SHORT TERM: (Through Friday)
Issued at 240 PM CST Thu Jan 21 2016
Deep trof with two very distinct vortices is continuing to dig
across the eastern Plains. The northern vortex is over eastern
Kansas producing some light snow...while the southern vortex is is
moving along the Oklahoma Texas border. Our CWFA is on the fringes
of influence of both of these vortices, and dry low level air is
being pulled from the east-northeast across the area as the surface
reflection of the trof deepens over Louisiana. This dry low level
flow more or less evaporated much of our precip this morning, and it
will continue to keep us dry tonight into Friday. Most short range
guidance is in agreement that accumulating precip will stay south
and east of the area through Friday...with the notable exception of
the HRRR which does show some light snow overnight across our
southern counties. Kept some low chance PoPs in southern zones to
cover this eventuality. Temperatures in the column should be cold
enough for snow...if anything should fall. Should see temperatures
continue to moderate with lows tonight generally in the upper teens
and highs Friday in the low 30s. We might even break through the
freezing mark across our southern zones.
Carney
.LONG TERM: (Saturday through Next Thursday)
Issued at 240 PM CST Thu Jan 21 2016
(Saturday and Sunday)
Focus will be temps with sfc ridge building into the region thru the
weekend.
With the sfc ridge building into the area Fri night, expect clouds
to gradually clear with system pulling newd out of the region. Winds
will gradually diminish, but perhaps more slowly. These two
features will have a large impact on temps overnight and will likely
end up with a large temp spread across the CWA. Given how quickly
temps can drop as winds become light and with potentially some snow
left, have trended twd the cooler guidance.
With upper level ridging and strong swly low level winds building
the thermal ridge into the region thru the later half of the
weekend, have trended twd the warmer guidance. Going forecast for
Sun may still be too cool. However, one concern is that sfc winds
may be more sely than sly or swly.
(Monday through Thursday)
Focus turns to system approaching the CWA on Mon. Mdls have come
into very good agreement regarding mass fields for this system. Some
timing differences still exist, but are in remarkably good agreement
for day 5. With the better agreement, have begun to fine tune the p-
types for this system. Given thermal profiles, believe this will be
mainly a light RA event. Cold air will move in behind the system Mon
afternoon into Mon night. There is a fair amount of uncertainty in
how quickly this will occur. Have therefore kept mention of RA thru
Mon, but trended twd a RA to mix to SN for Mon night.
With low level wly flow late in the period, have moderated temps for
now. Some timing differences on the next s/w to approach the region
into Thurs. Little if any precip is anticipated, but timing of this
trof may impact temps.
Tilly
&&
.AVIATION: (For the 00z TAFs through 00z Friday Evening)
Issued at 535 PM CST Thu Jan 21 2016
VFR flight conditions are expected tonight with extensive mid-high
clouds, with surface winds increasing some overnight and into
Friday morning. Will need to keep an eye on potential for LLWS
overnight as the low level winds in the lowest 2-3 km increase in
response to the deepening storm system to our south. Stratus currently
located across the Upper MS Valley and Great Lakes will advect
southward into the region on Friday bringing MVFR flight conditions.
Specifics for KSTL:
VFR flight conditions are expected tonight into early Friday
afternoon with extensive mid-high clouds. A deepening storm system
to our south will also produce increasing northerly surface winds.
Will need to keep an eye on potential for LLWS overnight as the
low level winds in the lowest 2-3 km increase, but present indications
are they will remain just above thresholds. Stratus currently
located across the Upper MS Valley and Great Lakes will advect
southward into the terminal Friday afternoon bringing MVFR flight
conditions.
Glass
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS HASTINGS NE
357 PM CST WED JAN 20 2016
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 356 PM CST WED JAN 20 2016
BIGGEST FORECAST ISSUE WILL BE SNOW AMOUNTS FOR TONIGHT.
SNOW HAS BEGUN A BIT EARLIER THAN ANTICIPATED IN OUR SOUTH IN
ADVANCE OF THE LONG-AWAITED APPROACHING WAVE WITHIN PROGRESSIVE
FLOW. BACKED UP THE START TIME OF THE ADVISORY FOR OUR KANSAS
COUNTIES TO INCLUDE THIS AFTERNOON. ALSO INCREASED SNOW AMOUNTS A
BIT IN OUR SOUTH...WHICH REQUIRED THE ADDITION OF A FEW COUNTIES ON
THE WESTERN EDGE OF THE WINTER WEATHER ADVISORY...TO INCLUDE
WEBSTER...SMITH...AND OSBORNE COUNTIES. EXPECTING A RATHER TYPICAL
13:1 RATIO FOR LIQUID TO SNOW.
FORECAST IS LARGELY ON TRACK FROM THE PREVIOUS FORECAST TONIGHT WITH
MINOR CHANGES MADE IN GENERAL. SNOWFALL MAY NOT FOLLOW A SMOOTH
TRANSITION FROM HEAVIER TO LIGHTER AMOUNTS FROM SOUTH TO NORTH...AS
WE COULD GET A FEW CONVECTIVE BANDS TO MOVE THROUGH...AS INDICATED
BY SHORT TERM MODELS SUCH AS HRRR AND RAP.
ANOTHER ISSUE MAY COME LATE THURSDAY AFTERNOON WHEN WE COULD LOSE
SATURATION IN THE DENDRITIC GROWTH ZONE BEFORE ALL OF THE LIGHT
LINGERING PRECIPITATION EXITS. IF THIS OCCURS...THEN WE COULD GET
SOME FREEZING DRIZZLE DEVELOP LATE AFTERNOON THURSDAY.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 356 PM CST WED JAN 20 2016
HAZARDOUS WX POTENTIAL: NOTHING SIGNIFICANT FORESEEN AT THIS TIME.
ALOFT: SOME TEMPORARY PROGRESSION OF THE LONGWAVES WILL OCCUR AS THE
PERSISTENT E PAC TROF MOVES ONSHORE SAT AND INTO THE CNTRL USA SUN-
MON. THIS TROF WILL SHIFT INTO THE ERN USA BEYOND MON. THEN IT`S
BACK TO THE PATTERN DOMINATING THE PAST 2 WEEKS...WITH THE E PAC
TROF/WRN N AMERICA RIDGE REDEVELOPING.
SURFACE: CANADIAN HIGH PRES WILL CREST OVER THE FCST AREA THU NIGHT
INTO FRI. SAT THE FCST AREA WILL BE IN THE WARM SECTOR OF A CLIPPER
TRACKING ACROSS SRN CANADA. LEE CYCLOGENESIS WILL ENSUE SAT NIGHT
WITH THE APPROACH OF THE UPR TROF. A PAC COLD FRONT WILL SLIP THRU
SUN AS THIS LOW CONTS TO ORGANIZE OVER OK/KS. WPC HAS THIS LOW OVER
CNTRL MO AT 12Z/MON WHICH IS CLOSE TO THE 06Z/12Z GFS AND THE
00Z/12Z GEM. INTERESTINGLY...THE 12Z GFS ENSEMBLE MEAN IS ON THE
SLOW END OF THE GUIDANCE SPREAD (OVER ERN KS/OK) WHILE THE 00Z/12Z
EC AND THE 00Z ENSEMBLE MEAN ARE ON THE FASTER END OVER IA.
HIGH PRES OVERTAKES THE REGION MON AND SINKS INTO THE SRN PLAINS TUE-
WED. DOWNSLOPE-WARMED AIR SHOULD FLOOD THE PLAINS AS A COUPLE
CLIPPERS TRACK N OF THE FCST AREA.
SOME DAILY DETAILS...
THU NIGHT: A LITTLE LIGHT SNOW OR FRZG DRZL COULD LINGER INTO THE
EVENING HRS MAINLY HWY 81. CONFIDENCE IS LOW. OTHERWISE CLOUDY. KEPT
LOW TEMPS A LITTLE ABOVE NORMAL.
FRI: LOTS OF UNCERTAINTY ON DEPARTURE OF THE LOW CLOUDS...BUT THE
THERMAL TROF SHIFTING E IS A GOOD SIGN. HIGH TEMPS ARE LOW
CONFIDENCE. THE SNOW THAT FALLS TONIGHT WILL BE A PLAYER.
SAT: INCREASING/DESCENDING MULTI-LAYERED CLOUDS...ESPECIALLY IN THE
AFTERNOON. IT`S LOOKING VERY MILD...BUT AGAIN SNOW COVER A
MITIGATING FACTOR.
SUN: THE FCST IS CURRENTLY DRY...BUT IT`S POSSIBLE SOME LIGHT PRECIP
COULD BREAK OUT IN THE AFTERNOON. NOT EXACTLY SURE ON PRECIP TYPE AS
WETBULB COOLING COULD BE AN ISSUE IN THE INITIALLY DRY AIR BELOW 10K
FT.
THE LAST 2 RUNS OF THE OP MODELS ARE ALL OVER THE PLACE WITH VERY
LIGHT QPF AND AMTS SUN NIGHT. THE 12Z GFS ENSEMBLE DOES HAVE A 30%
PROBABILITY FOR .10" IN 24 HRS OVER S-CNTRL NEB. THE 12Z EC ENSEMBLE
IS SIMILAR. SO THERE COULD BE A TOUCH OF LIGHT WINTRY PRECIP.
MON: A LITTLE LIGHT SNOW COULD LINGER INTO THE MORNING. COLD SECTOR
WITH THERMAL TROF PASSING THRU. COLDER AND PROBABLY M/CLOUDY.
THE-WED: DRY AND QUIET WITH TEMPS MODERATING.
&&
.AVIATION...(FOR THE 18Z KGRI/KEAR TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1158 AM CST WED JAN 20 2016
CEILINGS AND VISIBILITY WILL CONTINUE TO BE QUITE VARIABLE AT THE
BEGINNING OF THE FORECAST AS AN AREA OF STRATUS PUSHES NORTH. LOW
CONFIDENCE FOR THE TIMING OF THE RETURN OF STRATUS/SNOW AS ANOTHER
WINTER SYSTEM COMES INTO PLAY. A TEMPORARY WINDOW OF MVFR
CONDITIONS IS EXPECTED THIS LATE AFTERNOON/EARLY EVENING BEFORE
CONDITIONS DETIORATE ONCE AGAIN.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...WINTER WEATHER ADVISORY UNTIL NOON CST THURSDAY FOR NEZ085>087.
KS...WINTER WEATHER ADVISORY UNTIL NOON CST THURSDAY FOR KSZ006-007-
018-019.
&&
$$
SHORT TERM...HEINLEIN
LONG TERM...HALBLAUB
AVIATION...HEINLEIN
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1145 PM CST TUE JAN 19 2016
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 336 PM CST TUE JAN 19 2016
MAIN CONCERN IS FOG POTENTIAL TONIGHT. GENERAL SYNOPTIC PATTERN IS
QUITE PROGRESSIVE AS WE TRANSITION TO A HIGHER AMPLITUDE SCENARIO.
TONIGHT...THE CONCERN GOES TO FOG POTENTIAL TONIGHT AS WIND WILL BE
LIGHT FROM THE SOUTH. THE HRRR IS HITTING THE FOG POTENTIAL A LITTLE
HARD CENTRAL AND WEST. THE SREF IS ALSO HITTING FOG A LITTLE HARD
EVERYWHERE ACROSS THE CWA...ESPECIALLY WEST. I WENT WITH STRONG
WORDING IN THE FORECAST TO AREAS RATHER THAN PATCHY AND EXTENDED THE
FOG MENTION FARTHER EAST THAN THE PREVIOUS FORECAST.
WE MAY SEE A LITTLE SUN WEDNESDAY MORNING BEFORE IT CLOUDS BACK UP
IN ADVANCE OF THE NEXT WAVE QUICKLY APPROACHING. WARM AIR ADVECTION
SHOULD BOOST TEMPERATURES A GOOD 10 DEGREES WARMER ON WEDNESDAY
COMPARED TO TODAY. NOT EXPECTING PRECIP UNTIL PERHAPS BETWEEN 21Z
AND 00Z THURSDAY IN OUR FAR SOUTH...WHERE RAIN/SNOW COULD
OCCUR...BUT THE BETTER CHANCES WILL LIKELY BE TOWARD WEDNESDAY
NIGHT...IN THE LONG TERM FORECAST.
SUPERBLEND TEMPERATURES LOOKED REASONABLE...WHICH LOWERED
TEMPERATURES A BIT FOR WEDNESDAY HIGHS COMPARED TO THE PREVIOUS
FORECAST. THIS SEEMS REASONABLE CONSIDERING LINGERING FOG POTENTIAL
AND INCREASING SKY COVER BY AFTERNOON. BCONSRAW AND NAM12 SOLUTIONS
INDICATE THAT IT MIGHT EVEN BE A BIT COOLER THAN THE MID 30S I HAVE
ADVERTISED IN THE FORECAST....WITH COOLER TEMPERATURES EAST AND
WARMER WEST.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 336 PM CST TUE JAN 19 2016
ALOFT: VERY LITTLE CHANGE IN THE PATTERN IS ENVISIONED FOR AT LEAST
THE NEXT WEEK. A MEAN TROF WILL REMAIN OVER THE E PAC WITH THE MEAN
RIDGE OVER WRN N AMERICA. THE FLOW WILL INITIALLY BE MODERATELY
AMPLIFIED BUT WILL DEAMPLIFY TEMPORARILY AS A TROF MOWS DOWN THE
RIDGE FRI-SAT AND EMERGES INTO THE PLAINS SUN-MON. NW FLOW WILL
FOLLOW TUE.
AT 00Z/THU A SHORTWAVE TROF WILL BE MOVING IN AND AMPLIFYING...WITH
A MID-LVL CIRCULATION CLOSING OFF OVER NEB/KS BY 06Z. THIS LOW WILL
DROP SSE THU WITH QUIETER WX TO FOLLOW.
SURFACE: A WEAK COLD FRONT WILL MOVE THRU WED NIGHT. LEE
CYCLOGENESIS WILL BE UNDERWAY WED EVE WITH THE SFC LOW FAR TO THE S
OVER TX. CANADIAN HIGH PRES WILL GRADUALLY BUILD IN THU-FRI. RETURN
FLOW DEVELOPS SAT AS A CLIPPER HEADS E ACROSS SRN CANADA. A NICE
DOWNSLOPE-WARMED AIR MASS WILL OVERTAKE THE REGION...BUT SNOW ON THE
GROUND WILL TEMPER THE WARM-UP. THE NEXT PAC COOL FRONT WILL BE
MAKING ITS WAY THRU THE WRN USA AND WILL ARRIVE HERE LATE SUN. HIGH
PRES WILL MOVE IN MON AND DROP INTO THE SRN PLAINS TUE.
SOME DAILY DETAILS...
WED NIGHT: SNOW WILL BE BLOSSOMING OVER N-CNTRL KS AND EXPANDING N
INTO S-CNTRL NEB.
THU: A SWATH OF SNOW WILL PROBABLY STILL ENCOMPASS MUCH OF THE FCST
AREA THRU THE MORNING...RESULTING IN PERIODS OF SNOW. IT WILL
DIMINISH AND END IN THE AFTERNOON.
CURRENT EXPECTATION IS THAT MOST IF NOT ALL THE ACCUMULATING SNOW
WILL FALL WED NIGHT. WHILE SNOW WILL CONT INTO THU THE LIFT WILL NOT
BE ENOUGH TO RESULT IN MUCH ACCUM.
SNOW RATIOS: THIS IS TOUGH BECAUSE THE MESOSCALE NATURE OF THIS
SYSTEM WILL RESULT IN HIGHLY NON-UNIFORM LIFT. HIGHER UPWARD
VERTICAL MOTION (UVM) WILL RESULT IN HIGHER RATIOS WITHIN THE BAND.
GIVEN THAT THE BAND SHOULD BE TRANSIENT...KEPT RATIOS IN THE 10-12
RANGE.
BASED ON NAM SOUNDINGS...UVM WILL BE FAIRLY GOOD BELOW THE DGZ FROM
I-80 SOUTH. WITH TEMPS WARMER THAN -5C...THIS WILL RESULT IN
SUBSTANTIAL RIMING AND RATIOS CLOSE TO 10:1...IE A WETTER SNOW. N OF
I-80...IF THE NAM IS CORRECT UVM WILL BE WEAK RESULTING IN LESSER
QUALITY/SMALLER FLAKES. THAT TOO SUPPORTS A LOWER RATIO OF 10 OR
LESS.
ACCUMS: THESE RATIOS OFFER 1-2" AND THAT IS THE OFFICIAL FCST AT
THIS POINT...WITH 3-4" POSSIBLE IN A SMALLER AREA WHERE THE BAND IS
MORE PERSISTENT. WE JUST DON`T KNOW WHERE THAT WILL OCCUR.
SNOW ALGORITHMS FROM THE 06Z/12Z 20KM GFS AND 12Z/18Z NAM OFFER 2-4"
ACROSS MUCH OF THE FCST AREA...WITH ISOLATED 6" AMTS POSSIBLE.
THE EC CONTS TO BE ON THE HEAVY SIDE OF THE GUIDANCE DISTRIBUTION
CONSISTENTLY DUMPING ABOUT .50" SOMEWHERE NEAR ROOKS/OSBORNE/
MITCHELL COUNTIES. THAT INCLUDES THE LAST 4 RUNS. HOWEVER...THE 12Z
EC ENSEMBLE MEAN PROBABILITY FOR .50" IN 24 HRS 10% OR LESS. SO THAT
CONSTRAINS ME FROM GETTING OVERLY EXCITED.
WINDS WILL NOT BE A FACTOR WITH THIS EVENT.
FRI: DECREASING CLOUDS AS SUBSIDENT NW FLOW MOVES IN. HIGH TEMPS
PROBABLY COLDER THAN NORMAL.
SAT: TEMPS AT LEAST NORMAL IF NOT ABOVE. SNOW ON THE GROUND IS A
HUGE MITIGATING FACTOR. OTHERWISE...WIDESPREAD HIGHS IN THE 40S AND
50S WOULD BE ON THE TABLE.
SUN-MON: INCREASING CLOUDS. COOLER. POSSIBLY A TOUGH OF LIGHT
PRECIP AS THE FRONT/TROF MOVE IN.
&&
.AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1135 PM CST TUE JAN 19 2016
PRIMARY FORECAST CONCERN REVOLVES AROUND FOG AND STRATUS
POTENTIAL...ESPECIALLY THROUGH THE MORNING HOURS. WIDE SWATH OF
MVFR CEILINGS CONTINUES TO AFFECT BOTH TERMINAL AREAS...THOUGH
THEY ARE ON THE WRN FRINGES OF THE CLOUD COVER. CONFIDENCE IN THE
TIMING OF ANY IMPROVEMENTS OF CEILINGS DUE TO MOVEMENT OF THE
STRATUS IS NOT HIGH...AS EVEN JUST A FEW HOURS
OUT...MODELS/GUIDANCE CONTINUE TO SHOW NOTABLE DIFFERENCES. AS FAR
AS WINDS GO...NO SIGNIFICANT CHANGES EXPECTED THROUGH THE
PERIOD...REMAINING S/SERLY.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...HEINLEIN
LONG TERM...HALBLAUB
AVIATION...ADP
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1122 PM CST TUE JAN 19 2016
.SYNOPSIS...
ISSUED AT 325 PM CST TUE JAN 19 2016
H5 ANALYSIS THIS MORNING HAD A SHORTWAVE TROUGH EXTENDING
FROM THE DAKOTAS INTO WESTERN NEBRASKA AND SRN COLORADO. UPSTREAM OF
THE TROUGH...A LOW AMPLITUDE RIDGE EXTENDED FROM SWRN UTAH...NWD
INTO SRN ALBERTA. WEST OF THE RIDGE...A SHORTWAVE TROUGH WAS PRESENT
OFF THE COAST WASHINGTON STATE...OREGON AND NORTHERN CALIFORNIA.
CURRENT WV IMAGERY...HAS THE SHORTWAVE EXTENDING FROM EASTERN SOUTH
DAKOTA...INTO SOUTH CENTRAL NEBRASKA. FURTHER WEST...A BROAD PLUME
OF PACIFIC MOISTURE WAS NOTED AND EXTENDED FROM CALIFORNIA...EWD
INTO THE INTER MOUNTAIN WEST. A SECONDARY FEED OF MOISTURE EXTENDED
FROM BAJA CALIFORNIA INTO TEXAS AND THE OZARKS. AT THE
SURFACE...LIGHT SNOW IN ASSOCIATION WITH THE SHORTWAVE TROUGH...HAD
EXITED THE FORECAST AREA BY LATE MORNING. SNOW AMOUNTS WERE ON THE
ORDER OF 1 TO 2 INCHES ACROSS THE EASTERN HALF OF THE FORECAST
AREA...WITH SOME LOCALLY HEAVIER AMOUNTS UP TO 3 INCHES IN CUSTER
COUNTY. SEE OMAPNSLBF FOR DETAILS. SKIES WERE GENERALLY CLOUDY THIS
AFTERNOON WITH THE EXCEPTION OF LOCATIONS ALONG AND WEST OF HIGHWAY
61 FROM MERRIMAN TO IMPERIAL. TEMPERATURES THIS AFTERNOON WERE
GENERALLY IN THE 20S TO LOWER 30S.
&&
.UPDATE...
ISSUED AT 908 PM CST TUE JAN 19 2016
BINGO...DENSE FOG HAS FROMED ACROSS NRN NEB. THE RAP MODEL SHOWS
THIS FOG MOVING EAST OVERNIGHT AND LASTING 3 TO 6 HOURS. IT IS
POSSIBLE IT COULD FORM FARTHER SOUTH ACCORDING TO THIS MODEL BUT
THAT REMAINS UNCERTAIN AT THIS TIME.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 325 PM CST TUE JAN 19 2016
CLEARING CONTINUES TO SPREAD FROM WEST TO EAST ACROSS THE AREA THIS
EVENING. HOWEVER THE DRY AIR ALOFT AND GOOD RADIATIONAL COOLING WILL
QUICKLY COOL THE SFC TO THE DEW POINT. BOTH THE SHREF AND NAM ARE
SUGGESTING SOME FOG TO DEVELOP...AND WITH THE MELTING OF SOME OF THE
LIGHT SNOW FROM THIS MORNING ADDING TO THE BL MOISTURE AND NEAR CALM
WINDS...GROWING CONFIDENCE THIS COULD DEVELOP. UNSURE ON HOW DENSE
IT WILL GET SO NO HEADLINE BUT WILL NEED TO MONITOR THIS CLOSELY.
LOWS WILL BE MILD FOR MID JANUARY IN THE TEENS TO AROUND 20.
TOMORROW THE FOG WILL SLOWLY ERODE AS THE NEXT WAVE EJECTS ONTO THE
PLAINS. MOISTURE IS ON THE INCREASE...HOWEVER A DRY MID LEVEL WILL
HAVE TO BE OVERCOME BEFORE ANYTHING REACHES THE GROUND...THUS EXPECT
THE DAYTIME TO BE DRY. WEAK RIDGING AHEAD OF THE WAVE WILL PUSH SOME
WARM AIR BRIEFLY INTO THE REGION WHICH SHOULD HELP PUSH EARLY HIGHS
INTO THE MID 30S TO LOWER 40S...WARMEST WERE LITTLE TO NO SNOW PACK.
IF CLOUDS THICKEN QUICKLY...HIGHS COULD BE TO OPTIMISTIC.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 325 PM CST TUE JAN 19 2016
MID RANGE...WEDNESDAY NIGHT THROUGH FRIDAY...THE MAIN FORECAST
CHALLENGE IN THE MID RANGE IS SNOWFALL POTENTIAL WITH A SHORTWAVE
SYSTEM PROGGED TO CROSS THE CENTRAL AND SRN PLAINS WEDS NIGHT INTO
THURSDAY. BEGINNING LATE WEDNESDAY AFTERNOON...WITH THE APPROACH OF
AN UPPER LEVEL JET STREAK...A SHORTWAVE TROUGH...WILL DEEPEN AS IT
TRACKS FROM WYOMING INTO KANSAS. LIFT WILL BEGIN TO INCREASE
OVERNIGHT WEDNESDAY NIGHT...NORTH OF THE SHORTWAVE...WHICH CLOSES
OFF AT BOTH THE H7 AND H5 LEVELS AFTER 06Z THURSDAY. CROSS SECTIONS
TAKEN ACROSS THE EASTERN CWA INDICATE PLENTY OF DENDRITIC ZONE
MOISTURE...ALONG WITH A 12 HR PERIOD (06Z-18Z THURSDAY) OF FAVORABLE
LIFT. THIS AREA OF LIFT IS COLLOCATED WITH AN INVERTED SURFACE TROUGH
OF LOW PRESSURE WHICH IS PRESENT ACROSS THE EASTERN CWA...OR MAINLY
ALONG THE HIGHWAY 183 CORRIDOR FROM ANSLEY TO SPRINGVIEW. SREF QPF/S
AS WELL AS THE OPERATIONAL GFS AND NAM SOLNS INDICATE 10 TO 20
HUNDREDTHS OF AN INCH ALONG THIS CORRIDOR...WHICH BASED ON COBB
RATIOS OF 12 TO 1...YIELDS 1 TO 2 INCHES OF SNOW IN THE EASTERN HALF
OF THE CWA. BASED ON THE CROSS SECTIONS...THIS WILL BE A FAIRLY LONG
(12 HRS)...LIGHT INTENSITY EVENT. ATTM FEEL FAIRLY CONFIDENT IN
QPF/S AND ACCUMS...HOWEVER...LAYER PWATS IN THE NAM SOLN ARE RUNNING
A QUARTER TO BRIEFLY A HALF AN INCH DURING THE PERIOD AND THIS IS
CONCERNING. IF THIS VERIFIES...WE COULD BE LOOKING AT MORE SNOW
ACCUMS THAN CURRENT THINKING. WILL CONTINUE TO MONITOR THIS WITH THE
NEXT COUPLE OF FCST CYCLES. PROGRESSING INTO THURSDAY
AFTERNOON...THE UPPER LEVEL LOW WILL TRACK SOUTHEAST INTO THE
OZARKS...AS A RIDGE BEGINS TO BUILD INTO THE INTER MOUNTAIN WEST.
LIFT WILL BEGIN TO WEAKEN QUICKLY BY THURSDAY AFTERNOON IN THE
EAST...WHILE HIGH PRESSURE BUILDS SOUTH FROM THE EASTERN DAKOTAS.
SUBSIDENCE AND DRIER AIR...WILL BRING THE THREAT FOR SNOW TO AN END
DURING THE AFTERNOON HOURS. ON THURSDAY NIGHT...HIGH PRESSURE WILL
BUILD SOUTH INTO EASTERN NEBRASKA. LOW TEMPERATURES WERE TRENDED
DOWNWARD IN THE EAST GIVEN ITS PROXIMITY TO THE TRACK OF THE HIGH
WITH GUIDANCE UNDERCUT 2 TO 5 DEGREES. HIGH PRESSURE WILL TRANSITION
EAST INTO MINNESOTA AND NORTHERN IOWA BY FRIDAY AFTERNOON. WARMER
AIR WILL BEGIN TO PUSH INTO WESTERN NEBRASKA BY AFTERNOON...WITH H85
TEMPS REACHING ABOVE 0C WEST OF HIGHWAY 61. WINDS...ESPECIALLY EAST
OF HIGHWAY 61 WILL BE LIGHT...SO NOT MUCH MIXING WILL TAKE PLACE.
THIS WILL RESULT IN SUB FREEZING HIGHS GENERALLY EAST OF HIGHWAY
83...WHILE LOCATIONS WEST OF THIS ROUTE MAY REACH THE MID 30S TO
LOWER 40S IN THE EASTERN PANHANDLE.
LONG RANGE...FRIDAY NIGHT THROUGH TUESDAY...BEGINNING FRIDAY
NIGHT...RIDGING WILL BUILD EAST OF THE ROCKIES ONTO THE CENTRAL
PLAINS. MUCH WARMER H85 AIR WILL PUSH EAST WITH H85 TEMPS SAT
AFTERNOON OF 4 TO 8C. INHERITED FCST OF 40S TO LOWER 50S SATURDAY
ARE ON TRACK. A PACIFIC COOL FRONT WILL PUSH INTO THE FORECAST
AREA SUNDAY AFTERNOON. HIGHS WILL FALL BACK TO MORE SEASONAL
LEVELS SUNDAY...MONDAY AND TUESDAY. WITH THE FRONTAL
PASSAGE...THERE WILL BE A SMALL THREAT FOR RAIN OR SNOW SHOWERS
SUNDAY...FOLLOWED BY A SLIGHT CHANCE FOR SNOW ON SUNDAY NIGHT.
BEYOND TUESDAY...THE LATEST ECMWF AND GFS SOLNS DEVELOP A ZONAL
FLOW PATTERN NEXT WEEK WITH ARCTIC AIR WELL NORTH OF THE CWA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1122 PM CST TUE JAN 19 2016
THE MVFR/LOCAL IFR CIGS HAVE MOVE RAPIDLY EAST. IT IS QUITE
LIKELY VFR WOULD PREVAIL ALL AREAS FROM 15Z WEDNESDAY ONWARD.
SOME TIME WEDNESDAY EVENING...MVFR CIGS WILL DEVELOP FROM NORTH TO
SOUTH ASSOCIATED WITH A STRONG COLD FRONT. SNOW MAY BE UNDERWAY
ACROSS SHERIDAN COUNTY LATE WEDNESDAY EVENING.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 9 AM CST /8 AM MST/ WEDNESDAY FOR
NEZ005>010.
&&
$$
UPDATE...CDC
SYNOPSIS...BUTTLER
SHORT TERM...MASEK
LONG TERM...BUTTLER
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1231 AM CST WED JAN 20 2016
.UPDATE...
ISSUED AT 1230 AM CST WED JAN 20 2016
VISIBILITIES HAVE LOWERED TO 1/4 MILE OVER NORTHWESTERN AND NORTH
CENTRAL NORTH DAKOTA WITHIN THE BOUNDARIES OF THE DENSE FOG
ADVISORY. OTHER AREAS...MAINLY SOUTH CENTRAL NORTH DAKOTA...HAVE
REDUCED VISIBILITIES OF 1/2 TO 2 MILES OR MORE BUT EXPECT
DETERIORATING VISIBILITIES THERE AS WELL. CURRENT DENSE FOG ADVISORY
LOOKS VALID FOR THE MORNING HOURS. ONLY OTHER CONCERN WAS
TEMPERATURES...AS TEMPERATURES IN THE NORTHWEST HAVE LOWERED MORE
THAN EXPECTED...AND HAD TO ADJUST LOWS TO AROUND ZERO OR BELOW IN A
LARGE AREA MAINLY EXTENDING FROM CROSBY TO BEULAH/HAZEN. CONFIDENCE
IS LOW REGARDING HOURLY TEMPERATURE TRENDS...AS SOME AREAS TEMPS ARE
GOING DOWN AND OTHER AREAS (JAMES VALLEY) WITH SOUTH WINDS AND
TEMPERATURES ARE FAIRLY STEADY. SHORT TERM MODELS DO NOT HAVE THIS
DETAIL IN THEIR OUTPUTS.
UPDATE ISSUED AT 826 PM CST TUE JAN 19 2016
QUICK UPDATE TO EXPAND THE DENSE FOG ADVISORY INTO
MCKENZIE...DUNN...GRANT AND SIOUX COUNTIES PER OBSERVED TRENDS
0230 UTC.
UPDATE ISSUED AT 721 PM CST TUE JAN 19 2016
WEBCAM AND SURFACE OBSERVATION TRENDS THROUGH 0115 UTC DEPICT
VISIBILITY RAPIDLY FALLING ACROSS NORTHWEST AND INTO CENTRAL NORTH
DAKOTA WITH STRATUS BUILD DOWN. THUS...HAVE ISSUED A DENSE FOG
ADVISORY FOR THESE AREAS THROUGH 16 UTC WEDNESDAY MORNING. THE
SPATIAL COVERAGE OF THE ADVISORY IS FITTED TO CURRENT AREAS WITH
DENSE FOG...EXTRAPOLATED TO VISIBILITY TRENDS IN THE 21-00 UTC
HRRR ITERATIONS. A POTENTIAL EXPANSION OF THE ADVISORY IS
POSSIBLE LATER THIS EVENING.
UPDATE ISSUED AT 637 PM CST TUE JAN 19 2016
GIVEN TRENDS IN THE 21-23 UTC HRRR ITERATION VISIBILITY FORECASTS...EXPANDED
THE MENTION OF FOG TO ALL OF WESTERN AND CENTRAL NORTH DAKOTA
TONIGHT INTO WEDNESDAY MORNING. PATCHY DENSE FOG HAS ALREADY
DEVELOPED ACROSS NORTHWEST NORTH DAKOTA AS OF 00 UTC...AND EXPECT
A SLOW EXPANSION OF FOG WITH STRATUS BUILD DOWN THROUGH THE NIGHT.
A DENSE FOG ADVISORY MAY BE NEEDED.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 229 PM CST TUE JAN 19 2016
LOOKS LIKE THE VERY COLD AIR WILL TAKE AN EXIT FOR AWHILE.
CONCERNS NOW FOR THIS SHORT TERM PERIOD WILL FOCUS ON THE
POTENTIAL FOR FOG TONIGHT. MESOSCALE MODELS HAVE BEEN CONSISTENTLY
FORECASTING A SHALLOW COOL AND MOIST BOUNDARY LAYER FREE OF
CLOUDS ABOVE. HRRR DEVELOPS WIDESPREAD LOW VISIBILITIES THIS
EVENING AND OVERNIGHT.
SATELLITE TRENDS SO FAR TODAY SHOW THE STRATUS LAYER ERODING
IN LOW LEVEL WARM ADVECTION ACROSS WESTERN NORTH DAKOTA. THIS
PROCESS WILL BE DISRUPTED THIS EVENING AS SUNSET APPROACHES.
DURING THE COOLING HOURS IN THE EVENING EXPECT FOG TO FORM IN THE
CLEARING ZONE WITH THE CLOUDS CREEPING BACK WEST. THIS WILL MAKE
MIN TEMPERATURES IN THE CLEARING AREA A CHALLENGE. SO FAR HAVE
ACCEPTED THE CONSSHORT GUIDANCE GIVING LOWER TEENS ACROSS THE
WEST AND SINGLE DIGITS ABOVE ZERO EAST.
ON WEDNESDAY THE NEXT SHORTWAVE IN A SERIES OF SHORTWAVES WILL
BRING AN INCREASE IN MID/HIGH CLOUDS AND BREAK OF THE BOUNDARY LAYER
FOG DURING FORENOON. A SLIGHT CHANCE OF SNOW SEEMS REASONABLE BY
LATE AFTERNOON FAR WEST. HIGH WEDNESDAY IN THE 20S TO MID 30S.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 229 PM CST TUE JAN 19 2016
WEDNESDAY NIGHT THROUGH THURSDAY...COLD AIR ADVECTION AND A CHANCE
OF LIGHT SNOW WILL BEGIN POURING INTO SOUTHWEST NORTH DAKOTA
WEDNESDAY EVENING AS A SURFACE LOW AND ASSOCIATED MID LEVEL
SHORTWAVE SCOOT FROM SOUTHEAST MONTANA INTO SOUTH DAKOTA. THIS WILL
BE FOLLOWED BY ANOTHER SHORTWAVE THURSDAY...AS IT MOVES FROM WEST TO
EAST DURING THE DAY. THERE HAD BEEN SOME CONCERN FOR LIGHT FREEZING
RAIN WEDNESDAY EVENING...BUT THE NAM/SREF/GFS BUFKIT SOUNDINGS
INDICATE THAT IF IT DID DEVELOP...IT WOULD BE BRIEF...WITH A FAIRLY
QUICK TRANSITION TO LIGHT SNOW. NOT SEEING AN EXTENDED PERIOD OF
UPWARD VERTICAL MOTION WITH WITHIN THE SUPERCOOLED WATER DROPLET
REGIME...AND THE TRANSITION TIME FOR ANY GIVEN SOUNDING TO REACH
COLDER/HIGHER LEVELS OF SATURATION IS ACHIEVED FAIRLY QUICKLY
WEDNESDAY NIGHT. THUS...GIVEN THE BRIEF TIME AND ISOLATED COVERAGE
OF LIGHT FREEZING RAIN POTENTIAL...HAVE DECIDED TO STICK WITH THE
GIVEN FORECAST WHICH KEEPS A MENTION OF ONLY LIGHT SNOW. WILL
REVISIT THE SOUNDINGS AGAIN TONIGHT AND WEDNESDAY FOR ANY
SIGNIFICANT CHANGES TO THE ABOVE THINKING. OTHERWISE...CHANCES FOR
LIGHT SNOW WILL EXPAND INTO CENTRAL NORTH DAKOTA THROUGH THE DAY
THURSDAY. SNOWFALL ACCUMULATIONS THROUGH THURSDAY EVENING ARE
FORECAST AROUND A HALF INCH WEST AND CENTRAL...WITH AN ISOLATED SPOT
OF ONE INCH IN THE SOUTHWEST. THE CHANCE OF LIGHT SNOW EXITS THE
SOUTHERN JAMES RIVER VALLEY THURSDAY EVENING. WITH ONGOING COLD AIR
ADVECTION...HIGH TEMPERATURES THURSDAY WILL BE 5 TO 10 DEGREES
COLDER FROM WEDNESDAY...WHICH PUTS HIGHS THURSDAY FROM AROUND 10F
ABOVE IN THE TURTLE MOUNTAINS TO 25F SOUTHWEST.
THURSDAY NIGHT THROUGH SATURDAY...FOLLOWING THE ABOVE SHORTWAVE IS
AN UPPER LEVEL RIDGE WHICH WILL SHIFT FROM THE NORTHERN ROCKIES INTO
THE NORTHERN HIGH PLAINS FRIDAY INTO MOST OF SATURDAY. STRONG LOW
LEVEL WARM AIR ADVECTION FRIDAY AND SATURDAY WILL RESULT IN A
MODERATING TREND ALONG WITH DRY CONDITIONS. HIGHS FRIDAY WILL RANGE
FROM AROUND 20 IN THE JAMES RIVER VALLEY TO 40 WEST. BY SATURDAY
HIGHS WILL RANGE BETWEEN 30F AND 40F ACROSS WESTERN AND CENTRAL
NORTH DAKOTA.
THE WARMING TREND WILL COME TO AN END SATURDAY EVENING...AS A COLD
FRONT SWEEPS FROM NORTHWEST TO SOUTHEAST. THIS LEADS TO A CHANCE OF
SNOW AND COLDER TEMPERATURES SUNDAY. HIGHS SUNDAY THROUGH TUESDAY
ARE NEARLY THE SAME EACH DAY WITH HIGHS IN THE UPPER TEENS IN THE
TURTLE MOUNTAINS TO 20S ELSEWHERE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1230 AM CST WED JAN 20 2016
WIDESPREAD LIFR/VLIFR CONDITIONS IN FOG AND STRATUS EXPANDING ACROSS
WESTERN AND CENTRAL NORTH DAKOTA THROUGH WEDNESDAY MORNING. AFTER A
BRIEF RETURN TO VFR CONDITIONS AT SOME LOCATIONS WEDNESDAY
AFTERNOON...EXPECT MVFR CONDITIONS AGAIN WEDNESDAY EVENING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 10 AM CST /9 AM MST/ THIS MORNING FOR
NDZ001-002-009>011-017>023-034>036-042-045>047-050.
&&
$$
UPDATE...JV
SHORT TERM...WAA
LONG TERM...KS
AVIATION...JV
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
959 PM EST THU JAN 21 2016
.SYNOPSIS...
HIGH PRESSURE WILL SHIFT NORTHEAST TONIGHT. LOW PRESSURE WILL THEN MOVE
INTO THE TENNESSEE VALLEY ON FRIDAY AND THEN WEAKEN IN THE
APPALACHIANS FRIDAY NIGHT AS ANOTHER LOW DEVELOPS ALONG THE MID
ATLANTIC COAST. HIGH PRESSURE WILL GRADUALLY BUILD IN DURING THE
WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
MAIN AREA OF CONCERN FOR THE FORECAST UPDATE THIS EVENING IS THE
SNOW POTENTIAL FOR TOMORROW. THE O Z NAM ALONG WITH THE 18 Z GFS
HAVE SHIFTED SLIGHTLY FURTHER NORTH WITH THE HIGHER PRECIP AMOUNTS.
THE LATEST RUNS OF THE RAP AND HRRR HAVE ALSO SHIFTED PRECIP
SLIGHTLY FURTHER NORTH. FOR NOW HAVE TRENDED POPS SLIGHTLY FURTHER
NORTH WITHOUT CHANGING THE HEADLINE CONFIGURATION.
PREV DISCUSSION->
HIGH PRESSURE CENTERED OVER OHIO WILL MOVE OFF TO THE NORTHEAST
TONIGHT. CLOUDS WILL INCREASE AND PRESSURE GRADIENT WILL TIGHTEN
IN ADVANCE OF APPROACHING STORM SYSTEM. SO EXPECT AN EARLY DROP IN
TEMPERATURES AND THEN STEADY TO SLOWLY RISING READINGS.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
12Z GUIDANCE SUITE COMING INTO MORE AGREEMENT WITH IMPENDING
WINTER STORM. TREND HAS BEEN FOR PRECIPITATION SHIELD TO BE
SLOWER TO SPREAD IN FROM THE SOUTH. THIS WILL GRADUALLY MOVE
NORTH THROUGH THE DAY AS LOW PRESSURE MOVES INTO THE TENNESSEE
VALLEY. THUS HAVE SLOWED ONSET OF SNOW WITH MANY LOCATIONS NORTH
OF THE OHIO RIVER NOT BEGINNING UNTIL AFTERNOON.
BAND OF FRONTOGENESIS DEVELOPS INTO SOUTHERN SECTIONS LATE IN THE
DAY AND PERSISTS INTO THE EVENING BEFORE WEAKENING AS THE SURFACE
LOW DISSIPATES ON THE WEST SIDE OF THE APPALACHIANS AND ENERGY
TRANSFERS TO THE COAST. THIS WILL LEAD TO A PERIOD OF MODERATE TO
HEAVY SNOW ACROSS THE FAR SOUTHEAST COUNTIES. MEANWHILE THERE WILL
ALSO BE A VERY SHARP GRADIENT ON THE NORTHERN EDGE OF THE SYSTEM
THAT WILL PIVOT SLIGHTLY FRIDAY NIGHT AS ENTIRE SYSTEM MOVES
EAST. FELT CONFIDENT ENOUGH WITH CONSENSUS AMONGST GUIDANCE TO
INCLUDE A SHARP CUT OFF BOTH TO SNOW AND MORE SIGNIFICANT
SNOWFALL. THIS WILL RESULT IN NORTHWEST COUNTIES REMAINING DRY
THROUGH THE ENTIRE EVENT.
THIS GRADIENT LEADS TO SOME DIFFICULT DECISIONS REGARDING WINTER
WEATHER PRODUCTS AS SEVERAL COUNTIES HAVE A VERY LARGE RANGE FROM
SOUTH TO NORTH. FOR THE MOST PART HAVE USED HIGHER END OF THE
ACCUMULATIONS WITHIN EACH COUNTY TO TRIGGER HEADLINES.
SNOW WILL BE WINDING DOWN LATE FRIDAY NIGHT BUT STILL CONTINUE
INTO SATURDAY MORNING BEFORE ENDING IN THE EASTERN COUNTIES. NORTH
TO NORTHEAST WINDS WILL BECOME A BIT GUSTY AS SNOW COMES TO AN
END. CLOUDS AND WINDS WILL DECREASE SATURDAY AFTERNOON INTO
SATURDAY NIGHT AS HIGH PRESSURE STARTS TO BUILD IN. HAVE GONE
SIGNIFICANTLY BELOW GUIDANCE FOR LOWS SATURDAY NIGHT WHERE THERE
IS THE HIGHEST CONFIDENCE OF A DEEP SNOW PACK.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
HIGH PRESSURE WILL BE SITUATED JUST SE OF THE FA AT THE START OF THE
LONG TERM. SOUTHERLY FLOW WILL DEVELOP AND BRING WARMER
TEMPERATURES TO THE REGION SUNDAY AND MONDAY. HIGH TEMPERATURES
ACROSS MOST LOCATIONS WILL BE IN THE 30S BOTH DAYS.
A SYSTEM WILL APPROACH THE AREA ON MONDAY. PRECIPITATION WILL START
OUT AS RAIN ACROSS MOST LOCATIONS. PRECIPITATION WILL START TO
CHANGE OVER TO SNOW MONDAY NIGHT AS THE COLD FRONT WORKS INTO THE
REGION AND COLDER AIR FILTERS IN. SNOW SHOWERS WILL TAPER OFF
DURING THE DAY ON TUESDAY.
A COUPLE OF ADDITIONAL DISTURBANCES WILL MOVE THROUGH ON WEDNESDAY
AND THURSDAY. PRECIPITATION WILL GENERALLY BE IN THE FORM OF SNOW
SHOWERS WITH THESE EVENTS.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS ACROSS THE TERMINALS THIS EVENING WITH CIRRUS
SPREADING OVER THE REGION AS LOW PRESSURE APPROACHES THE AREA FROM
THE SOUTHEAST. HIGH PRESSURE CURRENTLY SITUATED JUST NORTH OF THE
AREA WILL SLOWLY SLIDE NORTHEAST AS LOW PRESSURE MOVES EAST ALONG
THE SOUTHERN TENNESSEE BORDER. A BROAD SHIELD OF SNOW WILL THEN
APPROACH THE AREA FROM THE SOUTH AS THE LOW PRESSURE HEADS EAST.
LATEST SET OF HIGH RES MODELS HAS THE SNOW REACHING CVG... LUK...
AND ILN FRIDAY BETWEEN 3 AND 6 PM. DUE TO THE TRACK OF THE LOW
SOME HIGH RES MODELS DONT HAVE THE SNOW EVER REACHING ILN.
CMH/LCK HAVE A SLIGHTLY LOWER CHANCE OF SNOW AS THEY ARE EVEN
FARTHER NORTH. MOST MODELS HAVE DAY REMAINING SNOW FREE THROUGH
THE TAF ISSUANCE. MVFR/IFR CIGS AND RESTRICTIONS IN VISIBILITIES
ARE LIKELY AT CVG/LUK WHILE LESS CONFIDENCE EXISTS FURTHER NORTH
AT ILN AND THE COLUMBUS TERMINALS. ANY SLIGHT CHANGES IN FORECAST
TRACK OF THE LOW WILL MEAN THE DIFFERENCE BETWEEN IFR AND VFR
VISIBILITIES.
OUTLOOK...MVFR/IFR CONDITIONS ARE EXPECTED WITH PRECIPITATION
SATURDAY AND THEN AGAIN MONDAY NIGHT INTO TUESDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...WINTER WEATHER ADVISORY FROM 4 PM FRIDAY TO 7 AM EST SATURDAY
FOR OHZ063>065-072-077.
WINTER STORM WARNING FROM 1 PM FRIDAY TO 7 AM EST SATURDAY FOR
OHZ073-074-078-080.
WINTER STORM WARNING FROM 10 AM FRIDAY TO 7 AM EST SATURDAY
FOR OHZ079-082.
WINTER STORM WARNING FROM 7 AM FRIDAY TO NOON EST SATURDAY FOR
OHZ081-088.
KY...WINTER STORM WARNING FROM 1 PM FRIDAY TO 7 AM EST SATURDAY FOR
KYZ089>093.
WINTER STORM WARNING FROM 10 AM FRIDAY TO 7 AM EST SATURDAY
FOR KYZ094>097.
WINTER STORM WARNING FROM 7 AM FRIDAY TO NOON EST SATURDAY FOR
KYZ098>100.
IN...WINTER WEATHER ADVISORY FROM 4 PM FRIDAY TO 7 AM EST SATURDAY
FOR INZ075-080.
&&
$$
SYNOPSIS...HAINES
NEAR TERM...HAINES
SHORT TERM...
LONG TERM...NOVAK
AVIATION...HAINES
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1256 AM EST WED JAN 20 2016
.SYNOPSIS...
AN UPPER LEVEL TROUGH ALONG WITH AN UPPER LEVEL DISTURBANCE
WILL COMBINE TO BRING SNOW TO THE AREA WEDNESDAY. HIGH PRESSURE
AND DRY AIR WILL RETURN FOR THURSDAY...UNTIL A LARGE AREA OF LOW
PRESSURE BRINGS ANOTHER WINTER SYSTEM TO THE REGION ON FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
HIGH CLOUDS ARE SPREADING INTO THE FORECAST AREA THIS
EVENING...AND RADAR ECHOES HAVE EXTENDED INTO SOUTHWEST INDIANA.
SOME OF THESE ECHOES ARE VIRGA...WITH THE INITIAL AREAS OF SNOW
JUST NOW REACHING SOUTHERN ILLINOIS. BASED ON CURRENT TRENDS AND
RECENT HRRR/RAP FORECAST CYCLES...THE TIMING FOR SNOW WAS SPED UP
SLIGHTLY. ALSO...POPS WERE INCREASED TO 100 PERCENT FOR MUCH OF
THE FORECAST AREA.
THE LATEST GUIDANCE SUGGESTS THAT THE CURRENT SNOWFALL FORECAST IS
STILL ON TRACK...FALLING VERY CLOSE TO THE SREF MEAN...AND IN
BETWEEN THE HIGHER NAM AND LOWER RAP SOLUTIONS.
PREVIOUS DISCUSSION >
CURRENTLY MOSTLY CLEAR SKIES WITH SOME PASSING CIRRUS AS THE NEXT
UPPER LEVEL SYSTEM CAN CLEARLY BE SEEN ON VISIBLE OFF TO OUR WEST.
WEDNESDAY MORNING AN UPPER LEVEL TROUGH WILL DIVE SOUTHEAST AND
PUSH INTO OUR FAR WESTERN ZONES BETWEEN 4 AM AND 7 AM. OMEGA
VALUES ON BOTH THE GFS AND NAM SHOW WEAK LIFT MOVING ACROSS THE
AREA RIGHT AROUND 6 AM ALONG WITH ISENTROPIC UPGLIDE COMMENCING.
THINK THE ONSET OF SNOW MIGHT BE DELAYED A BIT AS GFS AND NAM
FORECAST SOUNDINGS SHOW DRY AIR AROUND 750 MB SLOWLY ERODING
WEDNESDAY MORNING. THIS MAKES SENSE AS 12 Z 700 MB ANALYSIS SHOWED
DEWPOINT DEPRESSIONS OF GREATER THAN 20 DEGREES JUST OFF TO OUR
WEST.
LATEST SUITE OF HIGH RES AND GLOBAL MODELS HAVE SHOWN A SLIGHT
INCREASE IN AMOUNTS OF SNOWFALL ACROSS THE AREA BUT AM EXPECTING 1-2
INCHES WITH HIGHER AMOUNTS POSSIBLE ACROSS THE SOUTHWEST OF THE CWA.
THE TIMING OF THE SNOWFALL ALSO LOOKS TO OCCUR DURING THE MORNING
COMMUTE. GIVEN THE POTENTIAL IMPACTS DURING THE MORNING COMMUTE
AND SLIGHTLY HIGHER TOTALS HAVE EXTENDED THE WINTER WEATHER ADVISORY
ONE TIER OF COUNTIES NORTH.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THURSDAY/...
WEDNESDAY MORNING WILL START OFF WITH SNOW SPREADING ACROSS THE
CWA WITH HIGHER TOTALS FORECASTED ACROSS THE SOUTHERN PARTS OF THE
FORECAST AREA. FORECAST SOUNDINGS ON THE NAM AND GFS THEN SHOW
THE SNOW STARTING TO COME TO AN END WEST TO EAST BETWEEN NOON AND
2 PM. ACROSS OUR FAR EASTERN COUNTIES SNOW SHOULD COME TO AN END
BY 7 PM. FORECAST SOUNDINGS ON BOTH THE GFS AND NAM ALSO SHOW DRY
AIR STARTING TO MOVE IN AT 500 MB AS THE MAIN SHORTWAVE MOVES
OVERHEAD. THE DGZ APPEARS TO BE BETWEEN 550 AND 700 MB. THE
DEWPOINT AND TEMPERATURE LINES ON THE FORECAST SOUNDINGS CONTINUE
TO PULL APART IN THE AFTERNOON. THIS WILL BRING AN END TO THE
SNOW. THE TEMPERATURE PROFILE IS ALSO ISOTHERMAL RIGHT AROUND -10
DEGREES FROM 900 TO 700 MB. A LITTLE COLDER PROFILE WILL KEEP THE
SNOW GOING SLIGHTLY LONGER AS ICE CRYSTALS WILL BE ABLE TO GROW
WHERE AS A SLIGHTLY WARMER PROFILE WOULD FAVOR A QUICKER END TO
THE SNOW AND A POSSIBLE BRIEF PERIOD OF DRIZZLE. FOR NOW HAVE LEFT
THE MENTION OF DRIZZLE OUT AS CONFIDENCE REMAINS LOW.
WEDNESDAY EVENING SNOW WILL COME TO AN END AS A WEAK COLD FRONT
CROSSES THE AREA. SURFACE HIGH PRESSURE WILL THEN MOVE OVERHEAD
THURSDAY MORNING ALLOWING WINDS TO GO CALM. THURSDAY MORNING THE
GFS... EURO AND NAM ALL SHOW A CIRRUS SHIELD MOVING IN FROM THE
SOUTHWEST ALONG WITH SOME LOW CLOUDS LINGERING. GIVEN THE ABOVE...
LOW TEMPERATURES THURSDAY MORNING WILL LIKELY BE A TAD WARMER
THAN WEDNESDAY MORNINGS TEMPS. DURING THE DAY THURSDAY CIRRUS WILL
CONTINUE WITH SURFACE RIDGING WEAKENING ACROSS THE AREA AS THE
NEXT SYSTEM APPROACHES FROM THE WEST.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
MAIN FOCUS IN THE LONG TERM FORECAST WILL BE THE POTENTIAL FOR A
WINTER STORM TO AFFECT THE OHIO VALLEY REGION. THE IMPETUS FOR WHAT
WILL DEVELOP INTO A CLOSED MID LEVEL CIRCULATION EITHER OVER THE TN
VLY OR THE DEEP SOUTH IS STILL OFF THE WEST COAST ATTM...SO CAUTION
MUST BE USED IN THE FORECAST DUE TO THE OSCILLATIONS IN THE POSITION
AND TRACK OF THE MID LEVEL CIRCULATION. MODELS TEND TO HAVE ISSUES
WITH THE CLOSING OFF OF SUCH SYSTEMS...AND GIVEN THAT THE ENERGY IS
STILL OFF THE WEST COAST...THERE WILL BE TIME FOR OSCILLATIONS TO
CONTINUE UNTIL PERHAPS 12Z WEDNESDAY WHEN THE ENERGY WILL BE FULLY
SAMPLED.
THAT BEING SAID...OF THE MAIN OPERATIONAL MODELS FROM THE 01.19.12Z
RUN...THE ECMWF HAS TAKEN A MORE SOUTHERN TRACK ACROSS THE DEEP
SOUTH VERSUS THE OTHER MODELS (NAM...GFS...AND CMC). AS TO NOT JUMP
ON THE PURE 12Z ECMWF SOLUTION...WHICH WOULD BRING A PCPN SHIELD/MID
LEVEL DEFORMATION AXIS ONLY AS FAR NORTH AS THE OHIO RIVER...HAVE
TAKEN A BLEND OF THE 12Z GFS AND THE PREVIOUS 00Z ECMWF WHICH KEEPS
SOME CONTINUITY TO THE GOING FORECAST AND ALLOWS FOR SOME POTENTIAL
FOR A MORE NORTHERN TRACK TO BE A POSSIBLE SOLUTION. THUS...THE
CURRENT FORECAST WILL ALLOW PCPN SHIELD/MID LVL DEFORMATION AXIS
PUSH NORTHWARD TOWARD THE OHIO RIVER THURSDAY NIGHT...ALLOWING IT TO
PIVOT AS FAR NORTH/NORTHWEST AS THE I-71 CORRIDOR...AND THEN ALLOW
IT TO SHIFT EAST FRIDAY NIGHT INTO SATURDAY AS A COASTAL LOW/ENERGY
TRANSFER TAKES PLACE. BASED ON THIS SCENARIO...PCPN SHOULD REMAIN AS
SNOW WITH THE POTENTIAL FOR SIGNIFICANT SNOW ACCUMULATIONS ALONG AND
SOUTHEAST OF THE I-71 CORRIDOR AND PARTICULARY ALONG AND SOUTH OF
THE OHIO RIVER VALLEY. THUS...AT THIS JUNCTURE...4 OR MORE INCHES OF
SNOW MAY BE POSSIBLE ALONG AND SOUTH OF THE I-71 CORRIDOR WITH 6 OR
MORE INCHES POSSIBLE ALONG AND SOUTH OF THE OHIO RIVER. AGAIN...A
TRACK FARTHER SOUTH WOULD ONLY IMPACT LOCATIONS ALONG AND SOUTH OF
THE OHIO RIVER...AND A TRACK FARTHER NORTH WOULD PUSH THE THREAT
TOWARD THE I-71 CORRIDOR. AS THE COASTAL LOW TAKES SHAPE AND MOVES
NEAR AND OFF THE NEW ENGLAND COAST SATURDAY AFTERNOON AND
NIGHT...PCPN WILL TAPER OFF OVER THE REGION AS SURFACE HIGH PRESSURE
BUILDS BACK INTO THE OHIO VALLEY. AS FOR TEMPERATURES...HAVE TAKEN
BLEND OF PREVIOUS FORECAST AND THE 12Z GFS/00Z ECMWF. SOME
ADJUSTMENTS MAY HAVE TO BE MADE TO CURRENT VALUES DEPENDING ON WHERE
AND THE AMOUNT OF SNOW COVER WHICH MAY FALL...WHICH WILL HAVE AN
ALBEDO EFFECT/RADIATIONAL COOLING EFFECT.
FOR SUNDAY INTO MONDAY...HIGH PRESSURE WILL MOVE OFF TO THE EAST AS
THE NEXT LOW PRESSURE SYSTEM AND FRONT MOVE IN FROM THE WEST. THERE
ARE SOME TIMING AND STRENGTH DIFFERENCE AT THIS POINT...SO WILL
BRING A GRADUAL CHANCE OF PCPN FROM WEST TO EAST MONDAY AFTERNOON
INTO MONDAY NIGHT...WITH THE CHANCE CONTINUING INTO TUESDAY AS THE
SYSTEM MOVES THROUGH. TEMPERATURES WILL BE CRITICAL TO PTYPE.
CURRENTLY HAVE RAIN/SNOW FOR NORTHERN AREAS AND RAIN FOR SOUTHERN
AREAS...WITH A CHANGEOVER TO ALL SNOW ON TUESDAY IN THE WAKE OF THE
LOW AND FRONT. A BLEND OF THE TEMPERATURES HAVE BEEN USED WITH HIGHS
IN THE 30S TO AROUND 40 AND LOWS MAINLY IN THE 30S.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
FAST MOVING STORM SYSTEM WILL BRING SNOW TO THE TAFS MAINLY
BETWEEN 10Z-18Z TODAY. WHEN THE SNOW ARRIVES...VSBYS WILL DROP TO
IFR...WITH MVFR CIGS EXPECTED.
BEHIND THE SNOW...MODELS ARE HOLDING LOW LEVEL MOISTURE AND IFR
CIGS PAST 00Z. NAM IS MOST ENTRENCHED WITH LOWS...HOLDING THEM ALL
THE WAY THROUGH 30 HOURS. OTHER MODELS ARE NOT QUITE AS
PESSIMISTIC...BUT WILL LEAN TOWARDS THE NAM...AS IT SEEMS THAT
THE LOW CLOUDS ARE SOMETIMES HARD TO GET OUT OF THE REGION THIS
TIME OF THE YEAR.
OUTLOOK...MVFR/IFR CONDITIONS ARE EXPECTED WITH PRECIPITATION ON
FRIDAY INTO SATURDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...WINTER WEATHER ADVISORY FROM 4 AM EARLY THIS MORNING TO 7 PM
EST THIS EVENING FOR OHZ070>072-077>081-088.
KY...WINTER WEATHER ADVISORY FROM 4 AM EARLY THIS MORNING TO 7 PM
EST THIS EVENING FOR KYZ089>100.
IN...WINTER WEATHER ADVISORY FROM 4 AM EARLY THIS MORNING TO 7 PM
EST THIS EVENING FOR INZ066-073>075-080.
&&
$$
SYNOPSIS...HAINES
NEAR TERM...HAINES/HATZOS
SHORT TERM...HAINES
LONG TERM...HICKMAN
AVIATION...SITES
AREA FORECAST DISCUSSION
NWS Tulsa OK
920 PM CST THU JAN 21 2016
...UPDATE...
.DISCUSSION...
Have received a few reports of spotty freezing
drizzle and light snow across parts of NE OK and
NW AR this evening...although radar trends and past
few runs of the HRRR suggest an overall weakening
trend. This is also supported by the latest point
soundings which show significant drying the low-levels
after 06z.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 25 38 22 41 / 10 0 0 0
FSM 28 41 24 44 / 40 0 0 0
MLC 27 40 23 44 / 10 0 0 0
BVO 23 36 18 40 / 20 0 0 0
FYV 23 36 20 42 / 20 0 0 0
BYV 24 35 21 39 / 20 0 0 0
MKO 25 39 22 42 / 10 0 0 0
MIO 23 34 20 40 / 20 0 0 0
F10 26 39 22 43 / 10 0 0 0
HHW 30 42 25 47 / 30 0 0 0
&&
.TSA Watches/Warnings/Advisories...
OK...NONE.
AR...NONE.
&&
$$
SHORT TERM...18
LONG TERM....99
AREA FORECAST DISCUSSION
NWS Tulsa OK
1139 PM CST TUE JAN 19 2016
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
Areas of freezing drizzle continue over portions of NE OK and NW
AR late this evening. The heavier precipitation will begin to
shift east of the region around 08z. Low clouds/fog however will
continue overnight and likely persist through much of the day
Wednesday as surface winds slowly return to the southeast.
&&
.PREV DISCUSSION... /ISSUED 909 PM CST TUE JAN 19 2016/
..UPDATE...
DISCUSSION...
Precipitation across far eastern OK and northwest AR has been
convection in nature...resulting in pockets of brief moderate
sleet/freezing rain this evening. This has made for very slick
conditions across the region...especially in and around the Fort
Smith area and into parts of Madison county. HRRR trends are for
the heavier precipitation to shift east of the region after
06z...although could see a few more hours of light freezing
drizzle. Will leave the winter weather advisory as is for
now...but it may end of being cancelled a bit earlier than 12z.
&&
.TSA Watches/Warnings/Advisories...
OK...Winter Weather Advisory until 6 AM CST Wednesday for OKZ057-058-
062-063-068-069-072.
AR...Winter Weather Advisory until 6 AM CST Wednesday for ARZ001-002-
010-011-019-020-029.
&&
$$
AVIATION...12
AREA FORECAST DISCUSSION
NWS PENDLETON OR
636 PM PST THU JAN 21 2016
.SHORT TERM...TONIGHT AND FRIDAY...A COLD FRONT ALONG THE COAST WILL
SLOWLY MOVE EAST THROUGH THE REGION LATE TONIGHT AND FRIDAY. AS IT
DOES WE WILL SEE SOME INCREASING RAIN LATE TONIGHT THROUGH EARLY
FRIDAY WITH SNOW LEVELS AROUND 6000 FEET LOWERING TO 4500 FEET
FRIDAY AFTERNOON. SOUTHERLY WINDS AHEAD OF THE FRONT WILL CREATE
SOME BREEZY CONDITIONS FOR PORTIONS OF THE FORECAST AREA AND VERY
WIND IN THE SOUTHERN GRANDE RONDE VALLEY WHERE A WIND ADVISORY IS IN
EFFECT. MADE SOME MINOR CHANGES TO WINDS...TEMPERATURES AND CHANCE
OF PRECIPITATION IN THE FORECAST UPDATE.
&&
.PREV DISCUSSION... /ISSUED 344 PM PST THU JAN 21 2016/
SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT...PATCHY LIGHT RAIN IS
SHOWING ON RADAR FROM A WARM FRONT THAT IS LIFTING NORTHEAST ACROSS
THE AREA THIS AFTERNOON. THIS PART IF THE PRECIPITATION IS
DISORGANIZED ON RADAR AND MODELS EXCEPT THE HRRR HAVE INDICATED THAT
IT SHOULD HAVE ALREADY ENDED. THE NEXT BAND OF PRECIPITATION WILL
MOVE EAST OF THE CASCADES TONIGHT AS THE COLD FRONT MOVES ONSHORE.
I MAY MAKE LAST MINUTE ADJUSTMENT TO KEEP LIGHT RAIN OVER SOUTHEAST
WASHINGTON RATHER THAN SHOWING A BREAK BETWEEN THE BANDS SHOWN BY
THE MODELS. STRONG SOUTHERLY WINDS DUE TO FUNNELING ARE OCCURRING IN
THE THE SOUTHERN GRANDE RONDE VALLEY WHERE A WIND ADVISORY HAS BEEN
ISSUED. LOCALLY BREEZY WINDS ARE OCCURRING IN THE NORTHEAST OREGON
MOUNTAINS AND FOOTHILLS AS WELL. THE COLD FRONT WILL BE SLOW TO MOVE
INLAND. RAIN AND MOUNTAIN SNOW WILL SPREAD ACROSS THE REGION...AND
SNOW LEVELS WILL FALL TO 4000-5000 FT BY FRIDAY AFTERNOON. THIS
SYSTEM MOVES OUT FRIDAY EVENING BUT ANOTHER ONE MOVES INTO OREGON TO
SPREAD ANOTHER ROUND OF PRECIPITATION WITH LOWER SNOW LEVELS...
AROUND 2000 FT ON THE EAST SLOPES OF THE CASCADES AND 3000-4000 FT
ELSEWHERE BY SATURDAY MORNING. ANOTHER BETWEEN 4000 AND 5000 FEET
FRIDAY AFTERNOON. TEMPERATURES ON SATURDAY WILL ALSO BE LOWER AND
CLOSER TO NORMAL FOR THIS TIME OF YEAR WITH DAYTIME HIGHS IN THE MID
30S TO MID 40S. COONFIELD
LONG TERM...SUNDAY THROUGH THURSDAY...AN UNSETTLED WEATHER PATTERN
IS GENERALLY EXPECTED THROUGH THIS PERIOD. THE FLOW LOOKS TO BE
SOMEWHAT AMPLIFIED INTO EARLY NEXT WEEK. THUS COULD SEE A MOSTLY DRY
DAY MONDAY AFTER LINGERING SHOWERS ON SUNDAY AND SUNDAY NIGHT. THERE
COULD BE SOME PATCHY FOG AT SOME LOWER ELEVATIONS MONDAY MORNING,
BUT FOR NOW WILL CONTINUE TO ONLY MENTION IN THE GORGE AND THE
KITTITAS VALLEY. ANOTHER SYSTEM LOOKS TO APPROACH THE AREA MONDAY
NIGHT AND TUESDAY, BUT THERE ARE CURRENTLY TIMING DIFFERENCES
BETWEEN THE VARIOUS MID RANGE MODELS. DID SLOW THE ARRIVAL TIMING OF
THIS SYSTEM ON MONDAY NIGHT. OTHER THAN LOWERING POPS ALONG OUR
SOUTHERN BORDER, WILL LEAVE THE TUESDAY INTO WEDNESDAY FORECASTS
LARGELY AS INHERITED. THE FLOW COULD POTENTIALLY BECOME LESS
AMPLIFIED BY LATE WEEK AND WILL CONTINUE THE CURRENT CHANCE TO
LOCALLY LIKELY POPS FOR THURSDAY. 90
AVIATION...00Z TAFS...VFR CONDITIONS ARE MAINLY EXPECTED THROUGH
THE NEXT 24 HOURS. SCT-BKN MVFR CIGS SHOULD PERSIST AT KDLS AND KPSC
FOR AT LEAST THE FIRST 3 HOURS OF THIS PERIOD. THERE COULD ALSO BE
BRIEFER PERIODS OF SCT-BKN MVFR AT KYKM, BUT AM LESS CONFIDENT IN
OCCURRENCE. KPDT, KALW, KRDM AND KBDN SHOULD REMAIN VFR THROUGH THE
EVENING. A FEW LIGHT SHOWERS MAY ALSO AFFECT ALL SITES EXCEPT KRDM
AND KBDN THIS EVENING. A COLD FRONT WILL MOVE ACROSS THE REGION
FRIDAY MORNING. THIS FRONT WILL BRING PERIODS OF RAIN AND LOWER CIGS
TO ALL SITES. AT THIS TIME EXPECT SOME MVFR CIGS (POTENTIALLY VIS AS
WELL) AT KDLS, KBDN AND KYKM WITH THIS RAIN. WINDS WILL BE LESS THAN
10 KTS EXCEPT AT KALW, KPDT, KRDM AND KBDN WHERE GUSTIER DOWN SLOPE
WINDS WILL BE POSSIBLE AT TIMES. 90
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 43 52 34 45 / 20 60 20 50
ALW 43 52 36 46 / 20 60 20 50
PSC 39 49 37 45 / 20 60 20 50
YKM 34 43 34 43 / 60 60 40 50
HRI 41 50 36 46 / 20 60 20 50
ELN 33 40 31 40 / 60 60 40 60
RDM 39 49 34 44 / 30 60 50 50
LGD 38 45 34 44 / 10 40 20 50
GCD 35 46 33 42 / 10 60 30 60
DLS 41 50 38 47 / 60 60 50 60
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...WIND ADVISORY UNTIL 3 PM PST FRIDAY FOR ORZ049.
WA...AIR STAGNATION ADVISORY UNTIL 10 AM PST FRIDAY FOR WAZ027.
&&
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
91/91/91
AREA FORECAST DISCUSSION...UPDATED
NWS PENDLETON OR
344 PM PST THU JAN 21 2016
UPDATED AVIATION DISCUSSION
.SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT...PATCHY LIGHT RAIN IS
SHOWING ON RADAR FROM A WARM FRONT THAT IS LIFTING NORTHEAST ACROSS
THE AREA THIS AFTERNOON. THIS PART IF THE PRECIPITATION IS
DISORGANIZED ON RADAR AND MODELS EXCEPT THE HRRR HAVE INDICATED THAT
IT SHOULD HAVE ALREADY ENDED. THE NEXT BAND OF PRECIPITATION WILL
MOVE EAST OF THE CASCADES TONIGHT AS THE COLD FRONT MOVES ONSHORE.
I MAY MAKE LAST MINUTE ADJUSTMENT TO KEEP LIGHT RAIN OVER SOUTHEAST
WASHINGTON RATHER THAN SHOWING A BREAK BETWEEN THE BANDS SHOWN BY
THE MODELS. STRONG SOUTHERLY WINDS DUE TO FUNNELING ARE OCCURRING IN
THE THE SOUTHERN GRANDE RONDE VALLEY WHERE A WIND ADVISORY HAS BEEN
ISSUED. LOCALLY BREEZY WINDS ARE OCCURRING IN THE NORTHEAST OREGON
MOUNTAINS AND FOOTHILLS AS WELL. THE COLD FRONT WILL BE SLOW TO MOVE
INLAND. RAIN AND MOUNTAIN SNOW WILL SPREAD ACROSS THE REGION...AND
SNOW LEVELS WILL FALL TO 4000-5000 FT BY FRIDAY AFTERNOON. THIS
SYSTEM MOVES OUT FRIDAY EVENING BUT ANOTHER ONE MOVES INTO OREGON TO
SPREAD ANOTHER ROUND OF PRECIPITATION WITH LOWER SNOW LEVELS...
AROUND 2000 FT ON THE EAST SLOPES OF THE CASCADES AND 3000-4000 FT
ELSEWHERE BY SATURDAY MORNING. ANOTHER BETWEEN 4000 AND 5000 FEET
FRIDAY AFTERNOON. TEMPERATURES ON SATURDAY WILL ALSO BE LOWER AND
CLOSER TO NORMAL FOR THIS TIME OF YEAR WITH DAYTIME HIGHS IN THE MID
30S TO MID 40S. COONFIELD
.LONG TERM...SUNDAY THROUGH THURSDAY...AN UNSETTLED WEATHER PATTERN
IS GENERALLY EXPECTED THROUGH THIS PERIOD. THE FLOW LOOKS TO BE
SOMEWHAT AMPLIFIED INTO EARLY NEXT WEEK. THUS COULD SEE A MOSTLY DRY
DAY MONDAY AFTER LINGERING SHOWERS ON SUNDAY AND SUNDAY NIGHT. THERE
COULD BE SOME PATCHY FOG AT SOME LOWER ELEVATIONS MONDAY MORNING,
BUT FOR NOW WILL CONTINUE TO ONLY MENTION IN THE GORGE AND THE
KITTITAS VALLEY. ANOTHER SYSTEM LOOKS TO APPROACH THE AREA MONDAY
NIGHT AND TUESDAY, BUT THERE ARE CURRENTLY TIMING DIFFERENCES
BETWEEN THE VARIOUS MID RANGE MODELS. DID SLOW THE ARRIVAL TIMING OF
THIS SYSTEM ON MONDAY NIGHT. OTHER THAN LOWERING POPS ALONG OUR
SOUTHERN BORDER, WILL LEAVE THE TUESDAY INTO WEDNESDAY FORECASTS
LARGELY AS INHERITED. THE FLOW COULD POTENTIALLY BECOME LESS
AMPLIFIED BY LATE WEEK AND WILL CONTINUE THE CURRENT CHANCE TO
LOCALLY LIKELY POPS FOR THURSDAY. 90
&&
.AVIATION...00Z TAFS...VFR CONDITIONS ARE MAINLY EXPECTED THROUGH
THE NEXT 24 HOURS. SCT-BKN MVFR CIGS SHOULD PERSIST AT KDLS AND KPSC
FOR AT LEAST THE FIRST 3 HOURS OF THIS PERIOD. THERE COULD ALSO BE
BRIEFER PERIODS OF SCT-BKN MVFR AT KYKM, BUT AM LESS CONFIDENT IN
OCCURRENCE. KPDT, KALW, KRDM AND KBDN SHOULD REMAIN VFR THROUGH THE
EVENING. A FEW LIGHT SHOWERS MAY ALSO AFFECT ALL SITES EXCEPT KRDM
AND KBDN THIS EVENING. A COLD FRONT WILL MOVE ACROSS THE REGION
FRIDAY MORNING. THIS FRONT WILL BRING PERIODS OF RAIN AND LOWER CIGS
TO ALL SITES. AT THIS TIME EXPECT SOME MVFR CIGS (POTENTIALLY VIS AS
WELL) AT KDLS, KBDN AND KYKM WITH THIS RAIN. WINDS WILL BE LESS THAN
10 KTS EXCEPT AT KALW, KPDT, KRDM AND KBDN WHERE GUSTIER DOWN SLOPE
WINDS WILL BE POSSIBLE AT TIMES. 90
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 36 54 34 45 / 20 30 20 50
ALW 37 56 36 46 / 20 40 20 50
PSC 38 52 37 45 / 20 50 20 50
YKM 35 45 34 43 / 60 60 40 50
HRI 37 53 36 46 / 20 40 20 50
ELN 34 42 31 40 / 70 70 40 60
RDM 38 49 34 44 / 40 50 50 50
LGD 38 46 34 44 / 10 40 20 50
GCD 33 45 33 42 / 10 50 30 60
DLS 40 52 38 47 / 70 50 50 60
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...WIND ADVISORY UNTIL 3 PM PST FRIDAY FOR ORZ049.
WA...AIR STAGNATION ADVISORY UNTIL 10 AM PST FRIDAY FOR WAZ027.
&&
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
76/90/90
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1046 AM EST WED JAN 20 2016
.SYNOPSIS...
A WEAK UPPER LEVEL DISTURBANCE WILL CROSS THE CAROLINAS
TODAY. ANOTHER LOW IS EXPECTED TO DEVELOP TO OUR WEST ON THURSDAY
AND SPREAD PRECIPITATION ACROSS THE AREA THURSDAY NIGHT AND FRIDAY
AS IT MOVES ACROSS THE REGION. THE SYSTEM WILL EVENTUALLY MOVE OFF
THE MID ATLANTIC COAST OVER THE WEEKEND WITH DRIER HIGH PRESSURE
SPREADING BACK OVER THE REGION IN ITS WAKE ON SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM EST...EVEN VERY LIGHT RETURNS ON RADAR HAVE BEEN
REMARKABLY EFFICIENT AT PRODUCING A SLIPPERY DUSTING OF SNOW DESPITE
THE DRY SUB CLOUD AIR. BOTH THE LATEST RAP AND 12Z NAM ARE NOW
PRESENTING MORE ISENTROPIC UPGLIDE THROUGH A NARROW WINDOW THIS
AFTERNOON...AND WET BULB PROFILES SUPPORT MAINLY SNOW UNTIL MID
LEVELS DRY OUT THIS EVENING. GIVEN THE UPTICK IN QPF AND ASSOCIATED
COLD/SLIPPERY ROADWAYS IMPACT...HAVE EXPANDED THE ADVISORY INTO
STEPHENS COUNTY IN NE GA...THE UPSTATE MOUNTAINS...AND THE NC
FOOTHILLS AND NW PIEDMONT. WILL ALSO UPGRADE GRAHAM COUNTY TO A
WARNING WITH 3 TO 5 INCH SNOW TOTALS QUITE WIDESPREAD AS THE HEAVIER
RATES MOVES IN WITH THE REFLECTIVE BAND TO THE WEST.
THE UPPER SUPPORT WITH THE PASSING WAVE AND THE LOWER LEVEL
ISENTROPIC LIFT SHUT OFF QUICKLY TOWARD EVENING. MOISTURE LINGERS AT
LOW LEVELS...BUT MID LEVELS DRY OUT TO WARRANT A POSSIBLE SWITCHOVER
FROM WEST TO EAST OF LIGHT FREEZING RAIN OR FREEZING DRIZZLE. BLACK
ICE CONDITIONS WILL REMAIN A PROBLEM OVERNIGHT IN ANY AREAS
RECEIVING ACCUMULATING SNOW GIVEN MINS IN THE 20S AND LOWER 30S.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
AS OF 340 AM WEDNESDAY...LATEST IR SATELLITE IMAGES INDICATED THAT
THE SYSTEM THAT WILL IMPACT THE REGION LATE THIS WEEK WAS OVER THE
PACIFIC NORTHWEST. THE FORECAST WILL BE AIDED BY GENERALLY GOOD SHORT
RANGE MODEL AGREEMENT...AND DETAILED TEMPERATURE FIELDS FROM THE
NAM12. I WILL USE A BLEND OF THE SYNOPTIC FEATURES OF THE GFS AND
ECMWF FROM THURSDAY THROUGH SATURDAY. HOWEVER...ON FRIDAY...I WILL
BLEND IN LLVL THERMAL DETAILS FROM THE NAM12...BANKING ON THE BETTER
HANDLING OF COLD AIR DAMMING.
THURSDAY...0Z RUN OF THE GFS AND ECMWF HAVE TRENDED SLOWER WITH THE
ONSET OF WARM FRONT ASSOCIATED PRECIP. THIS FORECAST PACKAGE WILL
FEATURE SLOWER INCREASE OF POPS FRONT SW TO NE...DECREASING QPF. BY
LATE THURSDAY AFTERNOON...I WILL FORECAST LIKELY POPS ACROSS THE
UPPER SAVANNAH RIVER VALLEY TO THE EXTREME WESTERN NC MTNS...SCHC
OVER THE NC PIEDMONT AND FOOTHILLS. HIGH TEMPERATURES WILL GENERALLY
RANGE IN THE MID 40S.
BY 12Z FRIDAY...THE CENTER OF A WELL ORGANIZED LOW PRESSURE SYSTEM
IS FORECAST OVER NRN MS/AL...WITH GFS FASTER NEAR THE TN/AL/GA STATE
INTERSECTION. IT IS IMPORTANT TO NOTE THAT THE SFC HIGH WILL LIKELY
START TO RIDGE SW ACROSS THE MID ATLANTIC STATES AND ALONG THE EAST
FACING SLOPES OF THE SOUTHERN APPALACHIANS. THE PATTERN SUPPORTS
DEEP ISENTROPIC LIFT ALONG WITH IDEAL UPSLOPE FLOW. THE COMBINATION
OF DEEP MOISTURE AND DEEP LLVL LIFT WILL SUPPORT NEAR 100 PERCENT BY
THE PRE DAWN HOURS FRIDAY. COLD AIR DAMMING WILL SURGE ACROSS THE
FOOTHILLS AND PIEDMONT...SUPPORTED BY GUSTY NE WINDS. FREEZING
TEMPERATURES ARE EXPECTED TO SPREAD SW ACROSS THE EAST FACING
SLOPES...UPPER FRENCH BROAD VALLEY...AND EAST ACROSS THE I-40
CORRIDOR. GENERALLY...H85 WAA WILL SUPPORT RAINFALL THURSDAY
EVENING. HOWEVER...THE HEART OF THE CAD WILL ERODE THE WARM NOSE AND
SHOULD YIELD AN IMPRESSIVE ROUND OF SLEET ACROSS THE NC FOOTHILLS
DURING THE LATE NIGHT HOURS THURSDAY NIGHT. SURGING COLD AIR SHOULD
PROVIDE COLD THERMAL PROFILES...SUPPORTING A PERIOD OF FOOTHILL SNOW
DURING THE PRE DAWN HOURS FRI.
AFTER SUNRISE FRIDAY...THE LOW CENTER IS FORECAST TO LIFT NE ACROSS
NRN GA...PROVIDING A DEEPER WARM NOSE ACROSS THE WESTERN CAROLINAS
AND NE GA. HOWEVER...THE BL ACROSS THE NC ZONES WILL MAINTAIN
REINFORCING CAA. A CLASSIC FREEZING RAIN PROFILE DEVELOPS NORTH THE
NC/SC LINE DURING THE EARLY DAYLIGHT HOURS. THE FREEZING RAIN LINE
WILL LIFT NORTH ACROSS THE NRN FOOTHILLS AND NRN NC MTNS BY MID DAY.
THE PEAK H5 Q-VECTOR CONVERGENCE WILL CROSS OVER THE FORECAST AREA
ON FRI...PEAKING AROUND 18Z. THE ADDED FORCING SHOULD RESULT IN A
PERIOD OF MODERATE FZRA ACROSS THE I-40 CORRIDOR FRIDAY AFTERNOON.
BY 0Z SAT...DAMAGING FREEZING RAIN IS EXPECTED ACROSS THE UNIFOUR
EAST ACROSS THE UPPER I-77 CORRIDOR...NORTH OF LAKE NORMAN.
FRIDAY NIGHT...THE LOW CENTER WILL REACH THE OUTER BANKS OF NC AS
THE CENTER OF A CLOSED H5 LOW TRACKS OVER THE SOUTHERN APPALACHIANS.
GRADUALLY...H85 WINDS WILL INCREASE FROM THE NW...RESULTING IN CAA
ACROSS THE REGION. A WINTRY MIX AND RAIN WILL TRANSITION TO SNOW
FROM WEST TO EAST FRIDAY NIGHT. ACCUMULATING SNOWFALL SHOULD INCREASE
FRIDAY EVENING...THEN REMAINING STEADY OVER THE TN BORDER COUNTIES
THROUGH SAT. STORM TOTAL SNOWFALL IS FORECAST TO RANGE FROM NEARLY A
FOOT OVER THE HIGHEST ELEVATIONS OF AVERY COUNTY...TO 5 TO 8 INCHES
ACROSS THE BLUE RIDGE...WITH SEVERAL INCHES ACROSS THE I-40
CORRIDOR.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
AS OF 410 AM WEDNESDAY...SUNDAY AND MONDAY...N-S SFC HIGH PRESSURE
WILL SLIDE EAST ACROSS THE REGION UNDER THE AXIS OF A PASSING H5 L/W
RIDGE. CONDITIONS WILL REMAIN DRY WITH TEMPS RETURNING TO SEASONABLE
VALUES. A COLD FRONT IS FORECAST TO PASS OVER THE MTNS MON
NIGHT...PASSING SLOWLY EAST ON TUESDAY. THERMAL PROFILES WILL RESULT
IN LIGHT RAIN TO SWITCH TO SNOW ACROSS THE MTNS AND NC FOOTHILLS
EARLY TUESDAY MORNING. SHORTLY AFTER SUNRISE TUESDAY...PRECIP WILL
FALL AS RAIN ACROSS THE REGION. HIGH TEMPERATURE ON TUESDAY IS
FORECAST TO RANGE IN THE 40S ACROSS THE MTNS TO LOW TO MID 50S EAST.
&&
.AVIATION /16Z WEDNESDAY THROUGH SUNDAY/...
AT KCLT AND ELSEWHERE...LOWERING VFR CIGS WILL CONTINUE THROUGH THE
AFTERNOON...WITH MVFR LIKELY UNDER ANY BETTER SNOW SHOWERS..STARTING
AT KAVL FIRST. EXPECT THE SNOW POTENTIAL WINDOW TO START UP
MOMENTARILY AT KAVL AND THEN SPREAD EAST THROUGH THE AFTN...REACHING
KCLT MAINLY 20Z TO 00Z. THE WESTERLY FLOW ABOVE THE SFC IS NOT AS
FAVORABLE FOR PRECIP ACROSS UPSTATE SC...SO A VCSH REMAINS MORE
APPROPRIATE FOR KGSP/KGMU/KAND. CONDITIONS WILL IMPROVE AFTER 23Z.
WIND SHOULD COME AROUND TO SW THIS EVENING...AND EVENTUALLY NW OR N
AND LIGHT OVERNIGHT.
OUTLOOK...THURSDAY MIGHT BE A BRIEF BREAK IN THE ACTION. A STRONGER
STORM SYSTEM WILL ARRIVE FROM THE WEST THURSDAY NIGHT AND FRIDAY...
WITH WIDESPREAD RESTRICTIONS AND WINTRY PRECIPITATION POSSIBLE...
ESPECIALLY FROM KAVL TO KHKY. THE SYSTEM COULD LINGER INTO
SATURDAY...WITH WINTRY PTYPES POSSIBLY PERSISTING AS WELL.
CONFIDENCE TABLE...
15-21Z 21-03Z 03-09Z 09-12Z
KCLT HIGH 100% HIGH 98% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 96% HIGH 100% HIGH 100%
KAVL HIGH 98% MED 70% MED 64% MED 74%
KHKY HIGH 100% MED 73% HIGH 96% HIGH 100%
KGMU HIGH 100% HIGH 93% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 88% HIGH 94% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULE TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLET HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK:
WWW.WEATHER.GOV/GSP/AVIATION
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...WINTER WEATHER ADVISORY UNTIL 7 AM EST THURSDAY FOR GAZ010-017-
018.
NC...WINTER WEATHER ADVISORY UNTIL 7 AM EST THURSDAY FOR NCZ033-
035>037-048>053-056-057-059-062>065-068-069-501>510.
WINTER STORM WARNING UNTIL 7 AM EST THURSDAY FOR NCZ058.
SC...WINTER WEATHER ADVISORY UNTIL 7 AM EST THURSDAY FOR SCZ001>003.
&&
$$
SYNOPSIS...DEO
NEAR TERM...HG/PM
SHORT TERM...NED
LONG TERM...NED
AVIATION...HG/PM
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
602 PM CST THU JAN 21 2016
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 320 PM CST THU JAN 21 2016
MAIN FORECAST CONCERN IS THE SNOW THIS EVENING AND THEN HOW LONG THE
LOW CLOUDS REMAIN LATER TONIGHT AND TOMORROW.
STRONG UPPER WAVE CURRENTLY IN CENTRAL SD. FAIRLY WIDESPREAD LIGHT
SNOW HAS BEEN FALLING SINCE MID MORNING OVER MUCH OF EAST CENTRAL
SOUTH DAKOTA INTO PARTS OF SOUTHWEST MINNESOTA. A PERSISTENT
AREA OF SNOW DEVELOPED NEAR THE BUFFALO RIDGE FROM WATERTOWN
DOWN INTO LINCOLN COUNTY MINNESOTA. BY MID AFTERNOON THERE WERE
REPORTS OF 2 TO 4 INCHES IN LINCOLN COUNTY WHILE OTHER AREAS HAVE
GENERALLY BEEN LESS THAN 2 INCHES. EXPECTATION IS THAT THIS BAND OF
SNOW WILL PERSIST UNTIL THE UPPER LEVEL WAVE MOVES EAST LATER THIS
EVENING. BASED UPON THE RAP AND SATELLITE...THIS SHOULD END SNOW
NEAR I29 SHORTLY AFTER 00Z AND AROUND KMML BETWEEN 03Z AND 06Z.
LAST OF SNOW SHOULD EXIT COTTONWOOD...JACKSON...AND DICKINSON COUNTY
IOWA BY 09Z. ALONG HWY 14 BETWEEN MARSHALL AND BROOKINGS...ANOTHER
1 TO 2 INCHES OF SNOW IS EXPECTED BRINGING TOTALS TO 4 TO 5 INCHES.
ANOTHER 1 TO 2 INCHES ALSO POSSIBLE AROUND SLAYTON AND WINDOM WHERE
TOTALS WILL BE 1 TO 3 INCHES. ALONG AND SOUTH OF I-90...IN
SOUTHEAST SD AND NORTHWEST IOWA...BAND OF SNOW IS MUCH MORE NARROW
AND PROGRESSIVE SO ANY SNOWFALL WILL LAST ON A FEW HOURS. SNOWFALL
WILL GENERALLY BE LESS THAN AN INCH WITH LITTLE OR NO SNOW AROUND
SIOUX CITY.
SURFACE RIDGE IS EXPECTED TO MOVE SOUTH AND SETTLE ALONG THE WESTERN
MINNESOTA BORDER. NORTHERLY FLOW TONIGHT WILL GRADUALLY WEAKEN LATE.
THIS WILL BRING SOME COOLER AIR INTO THE REGION. HOWEVER...WITH LOW
CLOUDS EXTENDING TO THE INTERNATIONAL BORDER...AM PESSIMISTIC THAT
CLOUDS WILL ADVECT OUT OF THE AREA BEFORE THE SURFACE RIDGE ARRIVES
AND WINDS ALOFT DIMINISH LATER TONIGHT. AFTER THAT...REALLY RELYING
ON SUBSIDENCE TO ERODE CLOUDS. IN THE PAST...THIS HAS BEEN A SLOW
PROCESS TO OCCUR. FOR THAT REASON...EXPECTING SKIES TO REMAIN CLOUDY
ACROSS THE AREA ALL OF TONIGHT WITH BREAKS ONLY SLOWLY DEVELOPING
NORTH OF I90 DURING FRIDAY. THEREFORE...HAVE RAISED MINS TO 1O TO 15
ABOVE SOUTH OF I90 AND 5 TO 10 ABOVE NORTH OF I90. WITH CLOUDS AND
COOLER AIR MASS HIGHS WILL BE BELOW NORMAL WITH TEENS EAST OF THE
JAMES RIVER...AND 20S WEST OF THE JAMES RIVER.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 320 PM CST THU JAN 21 2016
MID-RANGE PORTION OF THE FORECAST WILL FEATURE QUIET CONDITIONS WITH
RELATIVELY MILD TEMPERATURES FOR THE WEEKEND AS UPPER RIDGE BUILDING
INTO THE CENTRAL CONUS ALLOWS WARMER AIR ALOFT TO WORK EASTWARD. AS
IS TYPICAL THIS TIME OF YEAR WITH A DECENT SNOW COVER...FULL EXTENT
OF WARMING WILL NOT BE REALIZED AT THE SURFACE...THOUGH LOCATIONS
WEST OF THE JAMES RIVER VALLEY STAND A STRONG CHANCE OF WARMING
ABOVE FREEZING FOR SEVERAL HOURS ON SATURDAY. WARMING WILL ACTUALLY
BEGIN LATE FRIDAY NIGHT...AS SURFACE RIDGE IN EASTERN FORECAST AREA
EARLY IN THE EVENING SHIFTS EAST...AND AN INCREASE IN SOUTH WINDS
AND THICKER CLOUD COVER BRINGS STEADY TO SLOWLY RISING TEMPERATURES.
CLOUDS WILL STICK AROUND MOST AREAS ON SATURDAY...BUT DECENT MIXING
IN THE STOUT SOUTHERLY FLOW AHEAD OF WEAK COOL FRONT SHOULD HELP
TEMPS WARM INTO THE UPPER 20S-MID 30S ALONG/EAST OF THE JAMES RIVER.
FARTHER WEST...OUR SOUTHWEST CORNER SHOULD SEE A SWITCH TO LIGHTER
WESTERLY FLOW BEHIND THE FRONT...BUT SLIGHT COOLING ALOFT SHOULD
LEAD TO DEEPER MIXING AND HELP WARM HIGHS INTO THE LOWER 40S. COOL
FRONT WORKS THROUGH SATURDAY NIGHT/SUNDAY...BECOMING A STATIONARY
BOUNDARY NEAR SOUTHEAST CWA BY LATE SUNDAY AS STRONGER SYSTEM DIGS
INTO THE CENTRAL PLAINS.
THIS LATE WEEKEND SYSTEM WILL BE OUR NEXT SNOW-PRODUCER FOR EARLY
NEXT WEEK. MODELS PRIOR TO TODAY HAVE BEEN ALL OVER THE PLACE WITH
TIMING/TRACK/STRENGTH OF THIS SYSTEM...BUT NOW THAT POWERFUL EAST
COAST SYSTEM IS COMING INTO CLEARER FOCUS...MODELS HAVE COME INTO
BETTER AGREEMENT ON THE NEXT TROUGH WHICH WILL DIVE THROUGH THE
ROCKIES EARLY NEXT WEEK. 12Z RUNS OF GFS/GEM/ECMWF ALL POINTING TO
CYCLOGENESIS SOMEWHERE IN THE OKLAHOMA PANHANDLE VICINITY BY SUNDAY
EVENING...THEN TRACKING THAT SURFACE LOW TOWARD THE MID-MISSISSIPPI
VALLEY BY LATE MONDAY. WITH FAIRLY GOOD AGREEMENT ON PLACEMENT AND
TIMING OF KEY FEATURES...COORDINATED WITH SURROUNDING OFFICES TO
BUMP POPS INTO LIKELY RANGE ACROSS OUR WEST SUNDAY NIGHT...AND FOR
CENTRAL/EASTERN PORTIONS OF THE FORECAST AREA ON MONDAY. UNCERTAIN
AT THIS POINT HOW MUCH PRECIPITATION/SNOW WILL FALL...BUT MAY HAVE
TO WATCH FOR SOME BANDED PRECIP AS ALL HINTING AT ZONE OF STRONGER
MID-LEVEL FRONTOGENESIS SLIDING ACROSS THE AREA LATE SUNDAY NIGHT
INTO MONDAY. WINDS INITIALLY NOT TOO STRONG...BUT AS LOW BECOMES A
BIT MORE WRAPPED UP ON MONDAY...EXPECT TO SEE AN INCREASE IN NORTH
WINDS WHICH COULD ALSO PRODUCE SOME BLOWING SNOW CONCERNS. AS FAR AS
TEMPERATURES...WILL SEE COOLER AIR MOVE BACK IN FOR MONDAY/TUESDAY
BUT JUST SLIGHTLY BELOW NORMAL.
RETURN TO SOMEWHAT MORE MILD WEST-NORTHWEST FLOW PATTERN SETS UP FOR
MID-LATE NEXT WEEK...BUT WITH LACK OF MODEL AGREEMENT IN TIMING OF
VARIOUS WAVES MOVING THROUGH THE FLOW...SEEING LARGE DIFFERENCES IN
PRECIP TIMING AND LOW LEVEL TEMPERATURE TRENDS. THUS OPTED TO STICK
CLOSE TO BROAD MODEL CONSENSUS FOR OUR WEDNESDAY/THURSDAY PERIODS
FOR NOW.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 559 PM CST THU JAN 21 2016
TRICKY AVIATION FORECAST THIS EVENING. LIGHT SNOW WILL BEGIN TO
MOVE INTO THE FSD TERMINAL EARLY THIS EVENING...AND SUX SLIGHTLY
LATER. BRIEF REDUCTIONS IN VISIBILITY ARE TO BE EXPECTED...AND
COULD DROP UNDER 2 MILES AT TIMES. ACCUMULATIONS WILL BE UNDER 1".
STRATUS WILL CONTINUE TO BE A PROBLEMATIC FORECAST TONIGHT.
CONSIDERABLE BREAKS IN THE STRATUS HAVE FORMED IN THE
REGION...AND HIGH RESOLUTION MODELS INDICATE THAT CEILINGS COULD
BOUNCE ALL OVER THE PLACE INTO FRIDAY MORNING. ANY BREAKS IN THE
CLOUDS COULD LEAD TO FOG AT TIMES...AND WILL CONTINUE TO MONITOR
FOR ANY REDUCTION IN VISIBILITIES DUE TO FOG THIS EVENING.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...SCHUMACHER
LONG TERM...JH
AVIATION...DUX
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
633 PM CST THU JAN 21 2016
.DISCUSSION...
ACROSS NORTHWEST AREAS...
THERMAL PROFILES ACROSS OUR FAR NORTHWESTERN AREAS ARE A BIT
CONCERNING. AT THE SFC...IT APPEARS THAT ANY SFC WAA AT THE SFC IS
NO LONGER IN PLACE AT CKV AND NEARBY AREAS. CURRENTLY...TEMPS
ACROSS THAT AREA ARE NEAR 32 AND 33 DEGREES. HOWEVER...DEWPOINTS
ARE IN THE MID TO UPPER 20S. LATEST HRRR AGGRESSIVELY BRINGS SOME
ENHANCED MOISTURE NORTHWARD BY 06Z. BUT...THIS LOOKS A LITTLE
OVERDONE BASED ON INITIALIZATION. STILL THOUGH...WILL NEED TO BUMP
UP THE FREEZING RAIN AND SLEET A TOUCH.
THE TRANSITION OVER TO SNOW IN THIS AREA LOOKS LIKE BETWEEN 6 AM
AND 8 AM WITH THE SLEET AND FREEZING RAIN FALLING PRIOR TO THAT
TIME.
FOR THE UPDATE...ONLY CHANGE FOR NOW WILL BE TO EXPAND SOUTHWARD
THE FREEZING RAIN AND SLEET AREA TOWARD WEST CENTRAL SECTIONS AS
WELL. I WILL ALSO INCREASE ICE ACCUM A BIT.
ACROSS THE REMAINDER OF THE MID STATE...
NO CHANGES TO THE OVERNIGHT BUT WE ARE CONCERNED WITH THE
POTENTIAL THAT SNOW MIGHT COME IN A LITTLE EARLIER FOR NASHVILLE
THAN THE CURRENT 11 AM TO 2 PM PREDICTION. WILL AWAIT THE NEW 00Z
NAM TO MAKE THAT DECISION BUT THAT 11 AM TO 2 PM TIME WINDOW MAY
NEED TO BE MOVED UP A FEW HOURS. ALSO...WILL CONTINUE TO KEEP A
WATCHFUL EYE ON OUR NORTHWEST AS MORE IN THE WAY OF FREEZING RAIN
AND SLEET COULD OCCUR PRIOR TO 6 AM. A DECISION TO EXPAND THE WSW
SOUTHWARD PRIOR TO 12Z MAY BE NEEDED ACROSS NORTHWESTERN AND
PERHAPS WEST CENTRAL AREAS.
&&
.AVIATION...
18Z TAF DISCUSSION.
BNA/CKV/CSV...MOISTURE CONTINUES TO ADVECT NE`WD INTO MIDDLE
TENNESSEE AS A SURFACE LOW TRACKS FROM THE GULF COAST TOWARD THE
TENNESSEE VALLEY. HRRR SHOWS RAIN MOVING INTO MIDDLE TENNESSEE
THIS AFTERNOON, REACHING BNA & CKV AROUND 23Z, THEN THE PLATEAU
DURING THE EVENING. AS THE LOW CONTINUES TO MOVE TOWARD THE E/NE,
WINDS WILL TURN MORE NE`WD WITH FALLING TEMPERATURES AND WINTRY
PRECIPITATION DEVELOPING FROM WEST TO EAST OVERNIGHT AND TOMORROW
MORNING. LOOK FOR IFR CIGS THE NEXT 24 HRS ACROSS THE MID STATE
WITH WINDS INCREASING DRAMATICALLY AS THE SFC LOW EDGES CLOSER TO
MIDDLE TENNESSEE.
&&
.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE 35 37 25 32 15 / 100 100 80 20 0
CLARKSVILLE 30 32 23 31 13 / 90 100 60 20 0
CROSSVILLE 34 37 23 29 12 / 100 100 80 60 10
COLUMBIA 38 39 24 32 16 / 100 100 60 20 0
LAWRENCEBURG 39 41 25 33 18 / 100 100 80 20 0
WAVERLY 32 33 22 32 14 / 100 100 60 10 0
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL NOON CST SATURDAY FOR CLAY-FENTRESS-
JACKSON-OVERTON-PICKETT.
WINTER WEATHER ADVISORY FROM 6 AM FRIDAY TO 6 AM CST SATURDAY
FOR BEDFORD-COFFEE-GILES-LAWRENCE-MARSHALL-WAYNE.
WINTER STORM WARNING FROM 6 AM FRIDAY TO NOON CST SATURDAY FOR
CUMBERLAND-GRUNDY-PUTNAM-VAN BUREN-WARREN-WHITE.
WINTER STORM WARNING FROM 6 AM FRIDAY TO 6 AM CST SATURDAY FOR
CANNON-CHEATHAM-DAVIDSON-DE KALB-DICKSON-HICKMAN-HOUSTON-
HUMPHREYS-LEWIS-MAURY-PERRY-RUTHERFORD-SMITH-WILLIAMSON-WILSON.
WINTER STORM WARNING UNTIL 6 AM CST SATURDAY FOR MACON-
MONTGOMERY-ROBERTSON-STEWART-SUMNER-TROUSDALE.
&&
$$
SHORT TERM/AVIATION........01/BOYD
LONG TERM..................21
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1154 PM CST TUE JAN 19 2016
.UPDATE...
FOR 06Z AVIATION DISCUSSION.
&&
.DISCUSSION...
LATEST SURFACE ANALYSIS DEPICTS SNOW ACROSS THE NORTHERN HALF OF
MO. FREEZING RAIN AND SOME SLEET OVER SRN MO...SOME FRZ RAIN
ACROSS NRN AR. 00Z OHX SOUNDING REVEALED 850 MB TEMPS THAT WERE
SLIGHTLY WARMER THAN THE MODELS. WET BULB ZERO PROFILES AT THE 850
MB LEVEL SHOWS A RATHER IMPRESSIVE WEDGE OF WARMING ACROSS AR.
PORTIONS OF NRN AR AND SRN MO SHOW FRZ RA WITH TEMPS IN THE LOWER
TO MID 20S...A TESTAMENT AS TO THE DEGREE OF WARM WEDGING THAT IS
ON GOING. SFC LOW IS CURRENTLY LOCATED OVER ERN OK. SLIGHT
INCREASE IN STRENGTH IS EXPECTED WITH THE WARM AIR IN THE 800MB TO
900 MB LEVEL WORKING EASTWARD. THIS WARMER AIR MAY VERY WELL MAKE
IT INTO OUR SOUTHWESTERN COUNTIES PRIOR TO 12Z. THUS...I WILL GO
AHEAD AND INCLUDE MORE IN THE WAY OF SLEET AND FREEZING RAIN
ACROSS OUR SOUTHWESTERN AND SOUTH CENTRAL AREAS.
LATEST HRRR SHOWS PATCHY LIGHT PRECIP MAKING IT ACROSS THE TN
RIVER AND REACHING THE GROUND JUST AFT MIDNIGHT. THE MORE
SIGNIFICANT PRECIP APPEARS TO MAKE IT ACROSS THE TN RIVER RIGHT
AROUND 6 AM. BASED ON THE LATEST 18Z NAM SOUNDINGS...IT STILL
LOOKS LIKE ALL SNOW NORTH OF I-40. BUT...THAT SOUTHWEST AREA IS A
CONCERN AND MORE IN THE WAY OF SLEET AND FREEZING RAIN COULD
FALL. AGAIN...WILL OPT TO MODIFY THE WX GRIDS TO REFLECT THIS
ACROSS SOUTHWEST AND SOUTH CENTRAL AREAS. SFC TEMPS STILL EXPECTED
TO WARM ABOVE FREEZING ACROSS THE SOUTHWEST BY 9AM...AND THEN ALL
BUT THE PLATEAU AREA BY NOON.
UPDATE OUT SHORTLY.
&&
.AVIATION...
06Z TAF DISCUSSION.
COMPLICATED AVIATION WX FORECAST SCENARIO WITH POTENTIAL ICING CONCERNS
DUE TO FROZEN PCPN DEVELOPMENT CONTINUES. LATEST SHORT RANGE MODEL
CONSENSUS CONTINUING TO SHOW THAT ORGANIZED FROZEN PCPN DEVELOPMENT BEGINS
BY 20/08Z...LASTING CKV/BNA THRU 20/18Z...WITH CONTINUANCE OF FROZEN PCPN
IMPACTING CSV THRU 21/00ZZ. BEST ICING WINDOW PER FREEZING RAIN POTENTIAL
CKV/BNA 20/13Z-20/18Z AND CSV 20/18Z-20/24Z. CKV/BNA SHOULD EXPERIENCE A
TRANSITION TO LIGHT RAIN 20/18Z-21/00Z. MOST OF MOISTURE EXPECTED TO MOVE
EAST OF MID STATE 21/00Z-21/06Z...BUT A WEAK DISTURBANCE IN NWLY FLOW ALOFT
BEFORE SUBTLE UPPER LEVEL RIDGING INFLUENCES BUILD INTO THE MID STATE MIGHT
RESULT IN LIGHT FREEZING DRIZZLE BNA/CKV 21/02Z-21/06Z. CURRENT VFR CEILINGS
ARE EXPECTED TO LOWER TO STRATUS MVFR CEILINGS 20/07Z CKV-20/12Z CSV.
CEILINGS WILL EVENTUALLY LOWER INTO IFR/LIFR THRESHOLDS 20/18Z-21/06Z.
EXPECT PCPN TO RESULT IN LOWERING CURRENT VFR VSBYS TO IFR 20/12Z-20/18Z
WITH SOME IMPROVEMENT TO MVFR VSBYS CKV/BNA 20/18Z-21/06Z.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 6 PM CST WEDNESDAY FOR BEDFORD-
CANNON-CHEATHAM-CLAY-COFFEE-CUMBERLAND-DAVIDSON-DE KALB-DICKSON-
FENTRESS-GILES-GRUNDY-HICKMAN-HOUSTON-HUMPHREYS-JACKSON-LAWRENCE-
LEWIS-MACON-MARSHALL-MAURY-MONTGOMERY-OVERTON-PERRY-PICKETT-
PUTNAM-ROBERTSON-RUTHERFORD-SMITH-STEWART-SUMNER-TROUSDALE-VAN
BUREN-WARREN-WAYNE-WHITE-WILLIAMSON-WILSON.
&&
$$
SHORT TERM/AVIATION........31
LONG TERM..................21
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
913 PM CST THU JAN 21 2016
.DISCUSSION...
STRONG UPPER LEVEL TROUGH ON WATER VAPOR IMAGERY WAS LOCATED OVER
THE ARKLATEX TONIGHT. STRONG COLD FRONT HAS PUSHED WELL OFF THE
COAST AND TIGHT PRESSURE GRADIENT WILL KEEP SOME GUSTY WINDS IN
PLACE ALONG THE COAST. 925MB/850MB WIND FIELDS SEEM TO INCREASE
OVERNIGHT AS LOW PRESSURE DEEPENS TO THE EAST. ONLY AREAS THAT
SEEM TO BE MEETING WIND ADVISORY CRITERIA ARE ALONG THE COAST AND
THROUGH HOUSTON. HOUSTON HOU HAD A WIND GUST OF 38 KNOTS AT
QUARTER TO THE HOUR. WITH COLD AIR ADVECTION AND WINDY
CONDITIONS...WIND CHILLS FOR FRIDAY MORNING WILL BE IN THE 20S FOR
MOST AREAS. MAIN UPDATES TO THE FORECAST WERE TO UPDATE GRIDS FOR
LATEST WIND/TEMP/TD/POP/WX/SKY TRENDS. ALSO UPDATED WIND ADVISORY
FOR THE COASTAL AREAS.
39
&&
.PREV DISCUSSION... /ISSUED 529 PM CST THU JAN 21 2016/
AVIATION...
FRONT HAS NOW PUSHED THROUGH WILL GUSTY NW WINDS AT ALL SITES.
WITH STRONG COLD AIR ADVECTION WILL LIKELY SEE GUSTS CONTINUE
TONIGHT WITH STRONGEST WINDS AT GLS DOWNWIND OF THE WATER. SOME
QUESTION ABOUT LOW CLOUDS AS BOTH NAM AND RAP MODELS SHOWING 95
PERCENT RH AT 925 MB...DUE TO A WRAP AROUND LOWER DECK NOW SEEN IN
SATELLITE UPSTREAM. MORE CONFIDENT OF CLEARING EARLY TONIGHT AT
CLL AND LESS OF AN INFLUENCE AT LBX...BUT COULD SEE SEVERAL HOURS
OF 2500 TO 3500 FOOT DECK ELSEWHERE. HAVE BASED TAF ON THIS IDEA.
46
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 35 47 30 52 34 / 0 0 0 0 0
HOUSTON (IAH) 38 51 33 53 37 / 0 0 0 0 0
GALVESTON (GLS) 41 50 38 51 47 / 0 0 0 0 0
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...WIND ADVISORY UNTIL 9 AM CST FRIDAY FOR THE FOLLOWING ZONES:
BRAZORIA...CHAMBERS...GALVESTON...HARRIS...JACKSON...
MATAGORDA.
GM...SMALL CRAFT ADVISORY UNTIL 3 PM CST FRIDAY FOR THE FOLLOWING
ZONES: GALVESTON BAY...MATAGORDA BAY.
SMALL CRAFT ADVISORY FROM 9 AM FRIDAY TO MIDNIGHT CST FRIDAY
NIGHT FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE
MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM
FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS
FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH
ISLAND TO FREEPORT OUT 20 NM.
GALE WARNING UNTIL 9 AM CST FRIDAY FOR THE FOLLOWING ZONES:
WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO
60 NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL
OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60
NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...39
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
529 PM CST THU JAN 21 2016
.AVIATION...
FRONT HAS NOW PUSHED THROUGH WILL GUSTY NW WINDS AT ALL SITES.
WITH STRONG COLD AIR ADVECTION WILL LIKELY SEE GUSTS CONTINUE
TONIGHT WITH STRONGEST WINDS AT GLS DOWNWIND OF THE WATER. SOME
QUESTION ABOUT LOW CLOUDS AS BOTH NAM AND RAP MODELS SHOWING 95
PERCENT RH AT 925 MB...DUE TO A WRAP AROUND LOWER DECK NOW SEEN IN
SATELLITE UPSTREAM. MORE CONFIDENT OF CLEARING EARLY TONIGHT AT
CLL AND LESS OF AN INFLUENCE AT LBX...BUT COULD SEE SEVERAL HOURS
OF 2500 TO 3500 FOOT DECK ELSEWHERE. HAVE BASED TAF ON THIS IDEA.
46
&&
.PREV DISCUSSION... /ISSUED 341 PM CST THU JAN 21 2016/
DISCUSSION...
AT THE TOP OF THE 21Z HOUR...THE SURFACE COLD FRONT WAS TRAVELING
THROUGH THE CENTRAL FORECAST AREA...ROUGHLY ALONG A LUFKIN TO HOUSTON
METRO TO MATAGORDA BAY LINE. THE REMAINING THIN CONVECTION BANDS
RACING OUT AHEAD OF IT ARE NOW ACROSS CHAMBERS COUNTY AND POINTS
OFFSHORE. STRONG WEST-VEERING-NORTHWEST WINDS BEHIND THE COLD
FRONTAL BOUNDARY WILL STRENGTHEN TO WIND ADVISORY CONDITIONS LATE
THIS AFTERNOON AND PERSIST INTO THE EARLY EVENING. OFFSHORE WINDS
WILL REMAIN AMPLIFIED ALONG THE IMMEDIATE COASTLINE THROUGH FRIDAY
AFTERNOON. A PROGGED 45-50 KT LOW LEVEL JET WILL DEVELOP OVER EASTERN
TEXAS DURING THE OVERNIGHT EARLY FRIDAY MORNING HOURS. THESE STRONG
MID-LAYER NORTHERLIES WILL MIX DOWN OVER THE RELATIVELY WARMER LOCAL
BAY AND GULF WATERS...PRODUCING ADVISORY LEVEL WINDS THAT WILL GUST
TO GALE FORCE OUT IN THE GULF.
NICE CLEARING JUST TO THE WEST OF THE COLD FRONT...CLEARING SKIES
TO MOSTLY SUNNY BY SUNRISE WITH MINIMUMS REGISTERING IN THE INTERIOR
MID TO UPPER 30S/LOW 40S AT COAST. WIND CHILL WILL BE A FACTOR AS
IT WILL FEEL LIKE THE 20S OVER MANY INLAND COUNTIES...LOWER 30S
ALONG COAST. FRIDAY CONDITIONS WILL BE VERY NICE IF YOU ARE INTO
COOL SUNNY DAYS WITH A LIGHT NORTH BREEZE...50 F WILL BE THE MAGIC
MAXIMUM TEMPERATURE NUMBER SO AN AFTERNOON MAINLY SPENT IN THE
CHILLY 40S.
WEEKEND WEATHER WILL BE PLEASANT AS A 5H RIDGE AXIS TRAVELS ACROSS
THE SOUTHERN PLAINS STATES. THIS WILL EQUATE TO MOSTLY SUNNY SKIES
SATURDAY BECOMING PARTLY CLOUDY SUNDAY UNDER A WEAK NORTHERLY BREEZE
SATURDAY THAT WILL BE VEERING ONSHORE SUNDAY MORNING. A RELATIVELY
COOL SATURDAY ONLY WARMING INTO THE MEAN LOWER 50S WITH A SIGNIFICANT
WARM UP SUNDAY INTO THE LOWER TO MIDDLE 60S PER A RETURN (MOISTURE)
FLOW REGIME.
SUNDAY`S WARM AIR ADVECTION PATTERN WILL BE VERY SHORT-LIVED AS A
COLD FRONTAL PASSAGE MONDAY USHERS IN A DRY AND COOL CONTINENTAL
AIR MASS. NWP SOLUTIONS PUSH THE 85H FREEZING LINE CLOSE TO THE
COAST THAT...AFTER A PRE-FRONTAL SOUTHWESTERN WIND DAY MONDAY THAT
WILL HAVE DAILY TEMPS SPIKING IN THE UPPER 60S TO LOWER 70S...WILL
TRANSLATE TO TUE-WED MX/MNS IN THE 50S/30S-40S...RESPECTIVELY. BUT
BEFORE NEXT WEEK`S COOL DOWN COMMENCES...THERE WILL BE SLIGHT TO
MODERATE PRECIPITATION CHANCES FOCUSED ALONG THE COASTAL COUNTIES
AND MARITIME AREAS MONDAY AND TUESDAY. A HIGH 0.8-ISH INCH PWAT
AIR MASS JUST DOWNSTREAM OF MONDAY`S FRONTAL BOUNDARY SHOULD BE
UNSTABLE ENOUGH TO SUPPORT WARM SECTOR SHOWERS/ISOLATED STORMS
LATE MONDAY AND TUESDAY MORNING. THE ONLY OTHER CAVEAT WOULD BE
SHORT-LIVED (SEA) FOG DEVELOPMENT LATTER MONDAY BEFORE THE ARRIVAL
OF THE FROPA LATE MONDAY NIGHT THROUGH OVERNIGHT TUESDAY MORNING.
31
MARINE...
STRONG NORTHERLY WINDS WILL FOLLOW A COLD FRONT CURRENTLY MOVING TO
AND OFF THE COAST. EXPECT ADVISORY CONDITIONS OVER THE BAYS AND GALE
CONDITIONS OVER THE GULF FOR MOST OF TONIGHT. WINDS WILL SLOWLY
DIMINISH ON FRIDAY AND FRIDAY NIGHT. HIGH PRESSURE WILL THEN MOVE
OVERHEAD DURING THE WEEKEND AND BRING MOSTLY FLAG-FREE CONDITIONS.
MODERATE ONSHORE WINDS ARE EXPECTED TO DEVELOP ON MONDAY.
THE RATHER STRONG NORTHERLY WINDS MAY GENERATE LOW ENOUGH TIDES TO
CAUSE SOME PROBLEMS OVER THE HOUSTON SHIP CHANNEL. A LOW WATER
ADVISORY MAY BE NEEDED LATER TONIGHT OR BY EARLY FRIDAY MORNING.
40
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 35 47 30 52 34 / 0 0 0 0 0
HOUSTON (IAH) 37 51 33 53 37 / 0 0 0 0 0
GALVESTON (GLS) 43 50 38 51 47 / 0 0 0 0 0
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...WIND ADVISORY UNTIL 10 PM CST THIS EVENING FOR THE FOLLOWING
ZONES: AUSTIN...BRAZORIA...BRAZOS...BURLESON...CHAMBERS...
COLORADO...FORT BEND...GALVESTON...GRIMES...HARRIS...
JACKSON...MADISON...MATAGORDA...WALLER...WASHINGTON...
WHARTON.
GM...SMALL CRAFT ADVISORY UNTIL 3 PM CST FRIDAY FOR THE FOLLOWING
ZONES: GALVESTON BAY...MATAGORDA BAY.
SMALL CRAFT ADVISORY UNTIL 8 PM CST THIS EVENING FOR THE
FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL 20 NM TO 60 NM...WATERS FROM FREEPORT TO THE
MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND
TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH ISLAND TO
FREEPORT OUT 20 NM.
SMALL CRAFT ADVISORY FROM 9 AM FRIDAY TO MIDNIGHT CST FRIDAY
NIGHT FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE
MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM
FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS
FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH
ISLAND TO FREEPORT OUT 20 NM.
GALE WARNING UNTIL 9 AM CST FRIDAY FOR THE FOLLOWING ZONES:
WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO
60 NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL
OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60
NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...99
AVIATION/MARINE...99
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
1153 AM CST WED JAN 20 2016
.AVIATION.../18Z TAF CYCLE/
LIFR/IFR AND MVFR CONDITIONS PERSIST ACROSS THE REGION AS OF 1745Z
WITH LOW STRATUS CEILINGS REMAINING INTACT UNDERNEATH A STRONG
INVERSION. KAUS IS ON THE EDGE OF THE STRATUS DECK BUT CONTINUED
MVFR CIGS WILL CONTINUE TO MOVE IN FROM THE SOUTH THROUGH THE
AFTERNOON. KSAT/KSSF/KDRT ARE NOT EXPECTED TO IMPROVE MUCH FURTHER
THAN CURRENT CONDITIONS THROUGH THE AFTERNOON AS WELL. NAM BUFR
SOUNDINGS ALONG WITH LAMP GUIDANCE AND HRRR OUTPUT ALL SUPPORT
WORSENING FLIGHT CATEGORIES THIS EVENING STARTING NEAR OR AFTER 04Z.
EXPECT IFR/LIFR CONDITIONS AT ALL SITES WITH SOME POSSIBLE/LIKELY
POCKETS OF VLIFR WITH VISIBILITY RESTRICTIONS OCCURRING DOWN TO 1/2
SM AT TIMES DUE TO LOW CLOUDS/FOG. LOW LEVEL SATURATION MAY EVEN BE
GREAT ENOUGH FOR -DZ TO OCCUR AS WELL. CIGS/VIS WILL REMAIN LOW
THROUGH THURSDAY MORNING TILL 15-18Z BEFORE A CLEARING FRONT MOVES
THROUGH. CONDITIONS SHOULD RAPIDLY IMPROVE WITH THE PASSAGE OF THE
FRONT THURSDAY AFTERNOON /21Z/ TO VFR. SURFACE WINDS WILL BE WEAK
THIS AFTN AND OVERNIGHT AT 10 KT OR LESS FROM THE NORTH AND BECOMING
EAST TO SOUTHEAST AHEAD OF THE FRONT. WINDS WILL REALLY INCREASE
ALONG AND BEHIND THE FRONT TO THE WNW AT 15-20 WITH GUSTS TO 30 KT
THURSDAY AFTN. WILL PLACE MORE FOCUS ON WINDS IN SUBSEQUENT TAF
ISSUANCES.
&&
.PREV DISCUSSION... /ISSUED 1043 AM CST WED JAN 20 2016/
UPDATE...
THE COLD FRONT HAS MOVED SOUTH OF OUR CWA AND IN ITS WAKE LEFT
CLOUDY SKIES OVER SOUTH CENTRAL TEXAS. SURFACE WIND ARE LIGHT FROM
THE NORTH. THIS COMBINATION IS KEEPING TEMPERATURES DOWN AND WE
HAVE LOWERED THE HIGHS FOR TODAY. THE REST OF THE FORECAST LOOKS
TO BE IN GOOD SHAPE AND HAVE ONLY ADJUSTED HOURLY GRIDS TO ACCOUNT
FOR OBSERVATIONAL TRENDS.
PREV DISCUSSION... /ISSUED 427 AM CST WED JAN 20 2016/
SHORT TERM (TODAY THROUGH THURSDAY)...
THE LEADING EDGE OF A WEAK COLD FRONT EXTENDING FROM A SURFACE
LOW PRESSURE SYSTEM OVER SW ARKANSAS HAS ENTERED THE I-35 CORRIDOR
AND WILL CONTINUE TO PUSH TOWARDS THE GULF COAST OVER THE NEXT FEW
HOURS. ALTHOUGH THIS HAS RESULTED IN A NORTHERLY WIND SHIFT...COLD
AIR ADVECTION AT H850-925 IS WEAK AS THE TEMPERATURE GRADIENT IS
BECOMING NEARLY PARALLEL TO THE WIND. SHOWERS ASSOCIATED WITH THE
FRONT AND A WEAK SHORTWAVE BRIEFLY FORMED OVER WILLIAMSON COUNTY
AND EAST TOWARDS COLLEGE STATION AND ARE ATTEMPTING TO REFORM IN
FAYETTE COUNTY EAST OF LA GRANGE. HOWEVER...THE SURFACE POTENTIAL
TEMPERATURE AND ASSOCIATED DENSITY GRADIENT CONTINUES TO WEAKEN
WHICH SHOULD ALLOW FOR ONLY VERY ISOLATED SHOWERS. PATCHY FOG MAY
DEVELOP AHEAD OF THE FRONT IN THE COASTAL PLAINS OVER THE NEXT FEW
HOURS AND IN THE RIO GRANDE PLAINS THROUGH MID-MORNING WHERE THE
BOUNDARY WILL BE MOST DIFFUSE AND EVENTUALLY BECOME STATIONARY.
MODELS ARE GENERALLY IN GOOD AGREEMENT THAT THE FRONT WILL STALL
ALONG THE RIO GRANDE PLAINS INTO SOUTH TEXAS AND THE UPPER GULF
COAST. SW-NE ORIENTED ISENTROPIC ASCENT WILL SET UP OVER SOUTH
CENTRAL TEXAS TODAY TO CAUSE MOSTLY CLOUDY TO OVERCAST SKIES THAT
WILL LIMIT DAYTIME HEATING...THOUGH LOW LEVEL WARM AIR ADVECTION
SHOULD ALLOW HIGHS TO REACH THE MID TO UPPER 60S OVER THE SOUTHERN
ZONES...WHILE STRUGGLING TO REACH 60 DEGREES OVER OUR NORTHERN
ZONES. THIS WEAKLY DEFINED WARM FRONTAL BOUNDARY WILL PROGRESS TO
THE NORTHEAST WEDNESDAY EVENING AS ANOTHER SURFACE LOW DEVELOPS
OVER NORTH TEXAS IN RESPONSE TO A DIGGING AND INTENSIFYING UPPER
LEVEL TROUGH. THIS WILL KEEP THE REGION IN THE WARM SECTOR OF THE
SURFACE LOW AND ALLOW FOR MOSTLY CLOUDY SKIES AND POSSIBLY SOME
PATCHY ADVECTION FOG THAT WILL KEEP LOWS IN THE 40S AND 50S.
THE SURFACE LOW AND UPPER LEVEL TROUGH IN THE EURO CONTINUES TO
TRACK FURTHER SW THAN THE GFS...WHICH DEPICTS A DEEPER SYSTEM
FURTHER TO THE NE AND KEEPS MOST PRECIP OUT OF OUR AREA. EXTENDED
HI-RES MODEL RUNS AND THE NAM ARE CLOSER TO THE GFS...AND ALL
MODELS TAKE A COLD FRONT THROUGH THE REGION BY 18Z THURSDAY...SO
HAVE CONTINUED TO KEEP PRECIP CHANCES LOW AND CONFINED TO OUR
NE COUNTIES. MOST MODELS SHOW THERE IS A SMALL AMOUNT OF SURFACE
BASED INSTABILITY...SO ISOLATED THUNDERSTORMS WOULD BE POSSIBLE
SHOULD THE TRACK OF THE SYSTEM SIMULATED BY THE EURO VERIFY.
HOWEVER...ELEVATED FIRE WEATHER CONDITIONS IN THE RIO GRANDE
PLAINS ARE A GREATER CONCERN ON THURSDAY AFTERNOON AS MIN RH
VALUES IN THE LOWER 20S AND WINDS SUSTAINED TO 25 KNOTS AND
GUSTING ABOVE 30 KNOTS PERSIST BEHIND THE FRONT. THE HIGH
TEMPERATURE FORECAST...AND ASSOCIATED RH FORECAST...IS FAIRLY
TRICKY ON THURSDAY AS STRONG COLD AIR ADVECTION WILL BE GOING
AGAINST THE EFFECTS OF DAYTIME RADIATIONAL HEATING AND DOWNSLOPING
WINDS. IT CURRENTLY LOOKS LIKE THE COLD AIR ADVECTION WILL WIN OUT
OVER OUR NORTHERN ZONES WHERE HIGHS WILL BE IN THE LOWER TO MID
60S WHILE THE LATTER EFFECTS MAY WIN OUT OVER OUR SOUTHERN ZONES
AND RIO GRANDE PLAINS WHERE HIGHS WILL BE IN THE LOWER 70S.
LONG TERM (THURSDAY NIGHT THROUGH TUESDAY)...
STRONG 15-20 KNOT WIND GUSTS WILL CONTINUE THURSDAY NIGHT INTO
FRIDAY AS THE REGION REMAINS ON THE BACKSIDE OF A DEEPENING
CYCLONE OVER THE LOWER MISSISSIPPI VALLEY. THIS STRONGER N-NW FLOW
WILL KEEP HIGHS IN THE LOWER 50S OVER OUR NORTHERN AND EASTERN
ZONES...WHILE REMAINING IN THE LOWER 60S OVER THE RIO GRANDE
PLAINS WHERE THESE EFFECTS WILL BE WEAKER. CALM WINDS AND HIGH
PRESSURE OVERNIGHT FRIDAY INTO SATURDAY WILL ALLOW FOR LOWS IN
THE UPPER 20S IN THE HILL COUNTRY WITH A LIGHT FREEZE FOR MOST
AREAS ALONG AND NORTH OF HIGHWAY 90/INTERSTATE 10. SOUTHERLY WINDS
RETURN ON SATURDAY WITH WARMER THAN NORMAL TEMPERATURES IN THE
UPPER 60S AND LOWER 70S RETURNING ON SUNDAY AS UPPER LEVEL RIDGING
TAKES PLACE AHEAD OF OUR NEXT COLD FRONT THAT MOVES THROUGH ON
MONDAY. LOW MOISTURE LEVELS AND WEAK DYNAMIC FORCING WITH THIS
FRONT MAKES SHOWERS UNLIKELY ON MONDAY...WITH SLIGHTLY COOLER
THAN NORMAL TEMPERATURES AND DRY AIR MOVING IN FOR TUESDAY BEHIND
THE FRONT.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 52 66 39 53 32 / 20 20 0 0 0
AUSTIN BERGSTROM INTL AIRPORT 51 67 37 53 30 / 20 20 0 0 0
NEW BRAUNFELS MUNI AIRPORT 52 69 38 56 31 / 10 20 0 0 0
BURNET MUNI AIRPORT 49 62 35 52 30 / 10 20 0 0 0
DEL RIO INTL AIRPORT 46 69 37 62 34 / - 0 0 0 0
GEORGETOWN MUNI AIRPORT 50 63 37 51 29 / 20 20 0 0 0
HONDO MUNI AIRPORT 49 70 37 60 30 / - 10 0 0 0
SAN MARCOS MUNI AIRPORT 52 67 38 55 31 / 10 20 0 0 0
LA GRANGE - FAYETTE REGIONAL 56 68 39 54 32 / 20 30 - 0 0
SAN ANTONIO INTL AIRPORT 53 70 39 58 33 / 10 10 0 0 0
STINSON MUNI AIRPORT 53 71 39 59 33 / 10 10 0 0 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...ALLEN
SYNOPTIC/GRIDS...05
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1203 AM CST WED JAN 20 2016
.AVIATION...
NO SIGNIFICANT CHANGES TO PREVIOUS TAF PACKAGE. A WEAK COLD FRONT
IS STILL ON TAP TO CROSS THE FORECAST AREA DURING THE EARLY
MORNING HOURS. THE FRONT SHOULD MOVE ACROSS THE WESTERN TERMINALS
BETWEEN 08-10Z AND THE HOUSTON METRO AREA BETWEEN 11-14Z...AND
OFF THE COAST BETWEEN 15-18Z...RESULTING IN A N/NW WIND SHIFT.
ISOLATED TO SCATTERED SHOWERS ARE EXPECTED TO DEVELOP ALONG AND
AHEAD OF THE FRONT AS IT SAGS SOUTHWARD. VFR CONDITIONS POSSIBLE
TOMORROW AFTERNOON TO THE NORTH OF I-10 BEHIND THE
FRONT...HOWEVER MVFR CIGS LIKELY TO REMAIN IN PLACE BETWEEN
HOUSTON METRO AREA AND THE COAST.
THE FRONT SHOULD STALL OUT NEAR THE COAST TOMORROW AFTERNOON
BEFORE IT BEGINS TO MOVE INLAND AS A WARM FRONT. MVFR/IFR CIG
CONDITIONS AND AREAS OF FOG LIKELY TOMORROW NIGHT BETWEEN CONROE
AND THE COAST. 44
&&
.PREV DISCUSSION... /ISSUED 914 PM CST TUE JAN 19 2016/
DISCUSSION...
SFC ANALYSIS AT 03Z SHOWED COLD FRONT STRETCHING FROM N TX THROUGH
W C TX WITH A FEW SHOWERS ALONG IT SE OF THE METROPLEX. BASED ON
LATEST HRRR TRENDS AND 00Z NAM...FRONT SHOULD CONTINUE TO PUSH
SOUTH INTO THE AREA THROUGH THE MORNING. FRONT MAY BE SLOW TO
RETURN NORTH AS A WARM FRONT TOMORROW.
STRONGER SHORT WAVE TROUGH PUSHES BY ON THURSDAY SO THINK THAT
WILL SUPPORT BETTER RAIN CHANCES AND PROBABLY SOME THUNDERSTORMS
GIVEN ENOUGH INSTABILITY. THAT SAID...MAY GET A DRY SLOT TO PUSH
THROUGH AND KICK STORMS EAST.
MAIN CHANGES TO THE FORECAST WERE TO UPDATE T/TD AS WELL AS
POP/WX/QPF FOR ONGOING TRENDS AND NEW MODEL GUIDANCE.
39
PREV DISCUSSION... /ISSUED 600 PM CST TUE JAN 19 2016/
AVIATION...
VFR CEILINGS THIS EVENING SHOULD GRADUALLY BECOME MVFR BETWEEN
06-09Z AS THE SOUTHERLY FLOW CONTINUES TO DRAW ADDITIONAL LOW
LEVEL MOISTURE IN TO THE AREA AHEAD OF AN APPROACHING COLD FRONT.
OVERNIGHT WINDS WILL BE LIGHT...BUT SHOULD PRODUCE ENOUGH MIXING
IN THE BOUNDARY LAYER TO INHIBIT WIDESPREAD FOG FORMATION.
A WEAK COLD FRONT SHOULD MOVE ACROSS THE WESTERN TERMINALS
BETWEEN 07-09Z AND THE HOUSTON METRO AREA BETWEEN 12-15Z...AND
OFF THE COAST BETWEEN 15-18Z...RESULTING IN A N/NW WIND SHIFT.
ISOLATED TO SCATTERED SHOWERS ARE EXPECTED TO DEVELOP ALONG AND
AHEAD OF THE FRONT AS IT SAGS SOUTHWARD...SO I CONTINUE TO CARRY A
VCSH MENTION FOR ALL TERMINALS. THE FRONT IS EXPECTED TO REACH THE
COAST...HOWEVER THE NORTH FLOW WILL BE SHORT LIVED AT TERMINALS TO
THE SOUTH OF I-10. WINDS SHOULD BECOME LIGHT AND VARIABLE OVER THE
HOUSTON METRO AREA AND VEER TO THE NORTHEAST AT TERMINALS CLOSER
TO THE COAST BY TOMORROW AFTERNOON. 44
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 45 60 54 65 38 / 30 10 30 40 10
HOUSTON (IAH) 53 66 57 70 41 / 20 30 30 50 10
GALVESTON (GLS) 58 63 59 69 44 / 20 30 10 40 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...39
AVIATION/MARINE...44
AREA FORECAST DISCUSSION
NWS SEATTLE WA
258 PM PST WED JAN 20 2016
.SYNOPSIS...A SLOW MOVING FRONTAL SYSTEM WILL BRING RAIN TO WESTERN
WASHINGTON TONIGHT THROUGH FRIDAY MORNING. THE FRONT WILL MOVE EAST
FRIDAY AFTERNOON WITH RAIN CHANGING TO SCATTERED SHOWERS. AN UPPER
LEVEL LOW OVER OREGON WILL BRUSH THE AREA WITH A LITTLE RAIN ON
SATURDAY. AN UPPER LEVEL RIDGE JUST OFFSHORE WILL BRING DRIER
WEATHER SUNDAY AND MONDAY BUT A FEW SHOWERS MAY STILL BE AROUND.
ANOTHER FRONTAL SYSTEM SHOULD REACH THE AREA MONDAY NIGHT OR TUESDAY.
&&
.SHORT TERM...HIGH CLOUDS FROM AN APPROACHING WET FRONTAL SYSTEM
HAVE MOVED OVER W WA THIS AFTERNOON. RAIN IS NOT FAR BEHIND AS RADAR
IS PICKING UP A BAND OF RAIN TO THE SW HEADED TOWARD THE S WA COAST.
THE HRRR SEEMS TO HAVE A GOOD HANDLE ON THE ADVANCING RAIN...
BRINGING IT TO THE CENTRAL COAST AROUND 01Z/5 PM AND TO PUGET SOUND
AROUND 04Z/8 PM.
THE WARM FRONT FROM THIS SYSTEM WILL BRING STRONG WARM ADVECTION
WITH 40-60 KT S-SW WINDS ALOFT FROM 925MB-850MB TO W WA LATER
TONIGHT AND THURSDAY. THIS STRONG S-SW FLOW WILL CONTINUE THURSDAY
NIGHT AS THE SLOW MOVING COLD FRONT APPROACHES. THIS WILL PRODUCE
HEAVY RAIN OVER THE OLYMPICS AND N CASCADES TONIGHT THROUGH THURSDAY
NIGHT. THE SYSTEM WILL WEAKEN FRIDAY MORNING AS THE COLD FRONT MOVES
INLAND.
TOTAL PRECIP OVER THE AREA TONIGHT THROUGH FRIDAY MORNING
WILL BE AROUND 3-6 INCHES OVER THE OLYMPICS AND N CASCADES WITH 0.50-
1.00 OVER THE INTERIOR LOWLANDS. SNOW LEVELS WILL RISE TO NEARLY
7500 FEET BY MIDDAY THURSDAY.
WEAK AND COOL EASTERLY FLOW THROUGH THE CASCADE PASSES SHOULD ALLOW
SEVERAL INCHES OF LIGHT SNOW TO FALL TONIGHT INTO THURSDAY
MORNING...BUT THE STRONG WARMING ALOFT WILL PROBABLY OVERWHELM THE
COOL EAST LOW LEVEL FLOW FOR A CHANGE OVER TO RAIN BEFORE MIDDAY
THURSDAY.
WINDY CONDITIONS WILL DEVELOP OVER MAINLY THE COAST AND N INTERIOR
TONIGHT AND THURSDAY AS THE SYSTEM MOVES OVER THE AREA.
THE COLD FRONT WILL FINALLY BE PUSHED INLAND FRIDAY MORNING ALLOWING
THE RAIN TO TAPER OFF WITH A CHANGE TO SHOWERS IN THE AFTERNOON. A
WEAK UPPER LEVEL RIDGE WILL MOVE OVER THE AREA FRIDAY AFTERNOON FOR
A LITTLE DRYING.
THE LAST COUPLE OF MODEL RUNS HAVE CHANGED FOR SATURDAY. THE LATEST
SOLUTIONS NOW FORM A CLOSED LOW W OF THE N CA COAST ON FRIDAY...THEN
SWING IT NE TO ABOUT THE CENTRAL OREGON COAST SATURDAY MORNING.
INCREASING S FLOW ALOFT AHEAD OF THE LOW NOW SPREADS LIGHT RAIN
NORTHWARD ACROSS W WA SATURDAY MORNING. THE 18Z GFS IS EVEN A LITTLE
FASTER THAN THE 12Z GFS SO LIGHT RAIN MIGHT EVEN MAKE IT UP TO PUGET
SOUND A LITTLE BEFORE SUNRISE. RAIN WILL DIMINISH SATURDAY EVENING
AS THE SYSTEM MOVES E. KAM
.LONG TERM...MODEL SOLUTIONS ARE STILL EVOLVING FROM RUN-TO-RUN IN
THE EXTENDED PERIOD. AN UPPER LEVEL RIDGE JUST OFFSHORE SATURDAY
EVENING WILL EVENTUALLY MOVE OVER W WA MONDAY MORNING. THE 12Z GFS
WAS DRIER DURING THIS PERIOD...BUT NOW THE 18Z RUN HAS SHIFTED BACK
TO A PREVIOUS SOLUTION WHERE A SHORTWAVE TROUGH PUSHES THROUGH THE
RIDGE THEN BRINGS SOME SHOWERS TO THE AREA. FOR NOW...WITH LOW
CONFIDENCE IN THE MODEL SOLUTIONS I WILL KEEP A BROADBRUSH CHANCE OF
SHOWERS SUNDAY AND MONDAY.
MODELS HAVE BEEN BRINGING ANOTHER FRONTAL SYSTEM TO THE AREA EARLY
NEXT WEEK. EARLIER RUNS HAD IT ON MONDAY WHILE THE 18Z GFS HOLDS OFF
UNTIL MONDAY NIGHT AND TUESDAY. ANOTHER FRONTAL SYSTEM MAY ARRIVE
LATE WEDNESDAY. KAM
&&
.AVIATION...SOUTHWESTERLY FLOW ALOFT WILL CONTINUE TONIGHT AND
THURSDAY AS A FRONT STALLS NEAR THE COAST. SURFACE GRADIENTS WILL
BECOME INCREASINGLY SOUTHEASTERLY. THE AIR MASS IS STABLE WITH
INCREASING MOISTURE ALL LEVELS. RAIN WILL BEGIN ON THE COAST AROUND
01Z AND SPREAD INLAND BY 04Z OR SO.
CONDITIONS ARE GOOD VFR OVER MOST OF THE AREA EXCEPT FOR A PATCH
OF MVFR CEILINGS AROUND THE STRAIT OF JUAN DE FUCA. CEILINGS WILL
LOWER TONIGHT AS THE FRONT APPROACHES AND BY THE TIME RAIN BEGINS
THEY WILL BE 3-5K FT. SEVERAL HOURS OF MVFR CEILINGS ARE LIKELY
LATE TONIGHT AND THURSDAY MORNING.
KSEA...DISCUSSION ABOVE APPLIES. SOUTHEAST WIND 5-10 KT WILL
BECOME MORE EASTERLY TONIGHT...THEN SOUTHEAST 10-15 KT AFTER 12Z
THURSDAY. CHB
&&
.MARINE...A STRONG FRONT WILL MOVE INTO THE COASTAL WATERS THIS
EVENING AND THEN SLOWLY MOVE INLAND TONIGHT AND THURSDAY. GALE
WARNINGS ARE IN EFFECT FOR THE COAST..THE CENTRAL AND EASTERN
STRAIT...AND THE NORTHERN INLAND WATERS. SMALL CRAFT ADVISORIES
ARE IN EFFECT FOR THE REMAINING WATERS.
WINDS WILL EASE THURSDAY NIGHT AND ARE LIKELY TO REMAIN BELOW 20
KT FRIDAY AND SATURDAY. ANOTHER FRONT MAY APPROACH THE COAST
SUNDAY. CHB
&&
.HYDROLOGY...ANOTHER 3 TO 6 INCHES OF PRECIPITATION WILL FALL OVER
THE OLYMPICS AND NORTH CASCADES TONIGHT THROUGH THURSDAY
NIGHT...WITH THE SNOW LEVEL RISING TO 6500 TO 7500 FT. THIS WILL
PUSH THE SKOKOMISH RIVER BACK ABOVE FLOOD STAGE AGAIN PROBABLY
SOMETIME THURSDAY MORNING. THE ONLY REAL QUESTION IS WHETHER OR NOT
IT WILL REACH ITS MAJOR FLOOD STAGE. THE FLOOD WATCH WILL REMAIN IN
EFFECT.
OTHER WESTERN WASHINGTON RIVERS FLOWING OFF THE OLYMPICS AND THE
NORTH CASCADES WILL ALSO RISE SIGNIFICANTLY. HOWEVER NORTHWEST RIVER
FORECAST CENTER GUIDANCE SHOWS MOST OF THESE RIVERS...THE SATSOP...
ELWHA...DUNGENESS...SKAGIT...AND STILLAGUAMISH...CRESTING AT MOST
WITH AROUND 70 PERCENT OF THE DISCHARGE NEEDED TO REACH FLOOD STAGE.
SO THE THREAT ON THESE RIVERS LOOKS PRETTY LOW. THE GUIDANCE FOR THE
NOOKSACK SHOWS IT GETTING CLOSEST TO FLOOD STAGE...THE SOUTH FORK
NOOKSACK SPECIFICALLY...BUT STILL LESS THAN 80 PERCENT OF THE
DISCHARGE CORRESPONDING TO FLOOD STAGE.
WITH FLOODING NOT EXPECTED ON ANY RIVERS OTHER THAN THE SKOKOMISH...
THE FLOOD POTENTIAL OUTLOOK WILL BE ALLOWED TO EXPIRE THIS
AFTERNOON. OTHERWISE...RIVER FLOODING IS NOT EXPECTED THE NEXT 7
DAYS. KAM
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...FLOOD WATCH FROM THIS EVENING THROUGH LATE FRIDAY NIGHT FOR HOOD
CANAL AREA-LOWER CHEHALIS VALLEY AREA-OLYMPICS.
PZ...SMALL CRAFT ADVISORY COAST UNTIL 4 PM PST THIS AFTERNOON.
GALE WARNING COAST...CENTRAL AND E STRAIT AND NORTH INLAND
WATERS FROM 4 PM THIS AFTERNOON TO 7 PM PST THURSDAY.
SMALL CRAFT ADVISORY FOR ROUGH BAR UNTIL 7 PM PST THURSDAY FOR
GRAYS HARBOR BAR.
SMALL CRAFT ADVISORY UNTIL 4 PM PST THURSDAY FOR PUGET SOUND
AND HOOD CANAL-WEST ENTRANCE U.S. WATERS STRAIT OF JUAN DE FUCA.
SMALL CRAFT ADVISORY UNTIL 7 PM PST THURSDAY FOR ADMIRALTY INLET.
&&
$$
WWW.WEATHER.GOV/SEATTLE
YOU CAN SEE AN ILLUSTRATED VERSION OF THIS DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
AREA FORECAST DISCUSSION
NWS PORTLAND OR
257 PM PST WED JAN 20 2016
.SYNOPSIS...A WARM FRONT WILL MOVE ONTO THE COAST LATE THIS
AFTERNOON AND INLAND TONIGHT...AND SNOW LEVELS WILL RISE WELL ABOVE
THE CASCADE PASSES. THE TRAILING COLD FRONT WILL MOVE INLAND THURSDAY
NIGHT AND FRIDAY. A LOW WILL APPROACH FROM THE SOUTHWEST FRIDAY NIGHT
AND SATURDAY FOR MORE RAIN AND CASCADE SNOW. SNOW LEVELS WILL LOWER
BACK DOWN TO NEAR THE CASCADE PASSES OVER THE
WEEKEND. THE PROGRESSIVE WEATHER PATTERN WILL CONTINUE PERIODS OF
RAIN AND CASCADE SNOW INTO NEXT WEEK.
&&
.SHORT TERM...RAIN SHOWERS HAS ENDED TO THE NORTH...BUT THE NEXT BAND
OF RAIN ASSOCIATED WITH A WARM FRONT IS JUST BEGINNING TO REACH THE
CENTRAL OREGON COAST. A LARGE HIGH CLOUD SHIELD IS MAKING IT
DIFFICULT TO SEE ON SATELLITE IMAGERY WHERE THE ACTUAL FRONT IS THIS
AFTERNOON. THE OFFSHORE BUOYS SHOW SE WINDAND DECREASING PRESSURE
SUGGESTING THE FRONT IS STILL QUITE A WAYS OFFSHORE. THERE HAS BEEN A
SMALL AREA OF LIGHTNING STRIKES AROUND 42N 130 W THAT MAY BE
ASSOCIATED WITH A FRONTAL BOUNDARY OR A LOW CENTER...BUT IT IS HARD
TO CURRENTLY TELL.
THE TALE END OF THIS WARM FRONT WILL BRUSH OVER THE REGION LATE THIS
AFTERNOON THROUGH LATE TONIGHT. RAIN WILL MOSTLY BE NORTH OF
SALEM...AND ACROSS THE HIGHER TERRAIN...WITH AROUND 0.5 INCH OF RAIN
FOR FOR THE NORTHERN CASCADES AND NORTHERN COAST RANGE...AND 0.05 TO
0.15 INCH FOR THE INTERIOR LOW LANDS NORTH OF SALEM. EXPECT VERY
LITTLE MEASURABLE RAIN...LESS THAN 0.05 INCH FOR NON-COASTAL AREAS
SOUTH OF SALEM. SNOW LEVELS WILL RAPIDLY RISE THIS EVENING WITH THE
PASSAGE OF THE WARM FRONT AND BE AROUND 7000 FEET LATE TONIGHT. THE
HIGHER VALLEYS IN THE SOUTH WASHINGTON CASCADES WILL HAVE A SLIGHT
CHANCE FOR FREEZING RAIN TONIGHT AND EARLY THURSDAY.
A BUILDING UPPER LEVEL RIDGE OVER THE PACIFIC NW WILL SLOW THE
PROGRESS OF THE COLD FRONT WHICH IS CURRENTLY BETWEEN 130W AND
140W...AND THE FRONT SHOULD STALL JUST OFF OF THE OREGON AND
WASHINGTON COAST THURSDAY. THE COAST WILL LIKELY SEE CONTINUOUS RAIN
BETWEEN THE WARM AND COLD FRONT...BUT MOST INTERIOR AREAS WILL HAVE
A BREAK IN THE RAIN LATE THURSDAY MORNING THROUGH EARLY
FRIDAY....BEFORE THE COLD FRONT MOVE INLAND THURSDAY NIGHT AND FRIDAY
MORNING.
THE FRONT WILL SPLIT OFFSHORE BEFORE IT PUSHES INLAND SENDING THE
HEAVIEST RAINFALL SOUTH OF OREGON...BUT STILL EXPECT A FEW HOURS OF
HEAVY RAIN WITH THE FRONT PASSAGE EARLY FRIDAY MORNING FOR THE COAST
AND COAST RANGE AND MID MORNING TO EARLY AFTERNOON EAST OF THE COAST
RANGE.SNOW LEVELS WILL REMAIN HIGH...ABOVE 7000 FEET. THE COAST AND
COAST RANGE WILL SEE THE MOST RAIN WHERE 0.75 TO 1.25 INCHES OF RAIN
IS EXPECTED THURSDAY EVENING THROUGH FRIDAY MORNING. OTHER AREAS CAN
EXPECT 0.35 TO 0.70 INCHES OF RAIN.
WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL SHORT WAVE DEEPENING SOUTH
OF THE ALEUTIAN ISLANDS NEAR 46N 161W. THIS TROUGH WILL SPLIT FROM
THE PARENT UPPER LEVEL TROUGH AS IT MOVES SW ACROSS THE PACIFIC ON
THURSDAY AND FORM A CUT OFF LOW OFFSHORE OF NORTHERN CALIFORNIA
FRIDAY AFTERNOON. THE LOW WILL THEN SEND A WARM FRONT ACROSS NW
OREGON AND SW WASHINGTON FRIDAY NIGHT AND SATURDAY AS THE LOW MOVES
INLAND NEAR THE OREGON/CALIFORNIA BORDER...FOR MORE RAIN AND CASCADE
SNOW. SNOW LEVELS WILL BE AROUND 4500 FEET. TJ
.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY. LITTLE CHANGE
TO THE FORECAST AS MODELS REMAIN IN REASONABLY GOOD AGREEMENT
THROUGH THE PERIOD. UPPER TROUGH SLIDES EAST OF THE CASCADES BY LATE
SATURDAY NIGHT WITH RESIDUAL SHOWERS TAPERING OFF AS SHORTWAVE
RIDGING BUILDS OVER THE REGION IN BETWEEN SYSTEMS. MODELS SUGGEST
THE NEXT DISTURBANCE MAY SPLIT OFFSHORE AS IT APPROACHES OVERNIGHT
SUNDAY...PERHAPS BRINGING SOME LIGHT RAIN AT TIMES...PARTICULARLY IN
SW WASHINGTON...BUT IN LIMITED AMOUNTS. MONDAY MAY BE DRY AS UPPER
LEVEL RIDGE AXIS MOVES OVER THE AREA...BUT THE NEXT FRONT WILL
ARRIVE TUESDAY FOR ANOTHER ROUND OF PRECIPITATION. THIS WILL BE IN
THE FORM OF RAIN FOR MOST LOCATIONS AS SNOW LEVELS WILL RISE ABOVE
6000 FEET BY LATE MONDAY BEFORE THE BULK OF THE MOISTURE ARRIVES.
&&
.AVIATION...A WARM FRONT TO LIFT NORTH THROUGH THE REGION LATER
THIS AFTERNOON AND EVENING. THIS WILL BRING INCREASING LIGHT RAIN
AND LOWERING CIGS...ALTHOUGH CONDITIONS SHOULD REMAIN MOSTLY VFR
WITH CIG HEIGHTS AT 4 TO 5 KFT. LIGHT RAIN TO CONTINUE
OVERNIGHT...MAINLY FOR THE COAST AND NORTHERN INTERIOR. CIGS IN
THESE AREAS MAY DROP DOWN TO AROUND 3 KFT BETWEEN 06Z AND 12Z THU.
INLAND AREAS FROM ROUGHLY KSLE SOUTH EXPECTED TO BE MOSTLY DRY
OVERNIGHT AND REMAIN VFR.
HAVE WIND SHEAR CONCERNS AFTER 12Z FOR KTTD AND KPDX AS SURFACE
FLOW WILL BE EASTERLY FROM THE GORGE WHILE FLOW ALOFT WILL
INCREASE FRONT THE SOUTH.
KPDX AND APPROACHES...LIGHT RAIN BEGINS AND CIGS LOWER TO AROUND 5
KFT THIS EVENING AS WARM FRONT MOVES THROUGH THE REGION. LIGHT
RAIN WILL LIKELY CONTINUE MUCH OF THE NIGHT...WITH CIGS LOWERING
FURTHER TO AROUND 3 TO 4 KFT. EXPECT LITTLE CHANGE THROUGH THE DAY
THU. EAST FLOW WILL INCREASE AFTER 09Z THU AND BRING LLWS
CONCERNS FROM ABOUT 12Z THEREAFTER. PYLE
&&
.MARINE...STRONG OCCLUDING LOW PRES NEAR 50N/145W THIS AFTERNOON.
THIS SYSTEM WILL BRING A WARM FRONT THROUGH THE WATERS LATER THIS
AFTERNOON AND THIS EVENING. GUSTY SOUTHERLY WINDS TO INCREASE THIS
EVENING AS WELL...WITH GUSTS 40 TO 45 KT EXPECTED OVER THE OUTER
WATERS WHERE A GALE WARNING IS NOW IN EFFECT. THE PRES GRADIENT TO
REMAIN FAIRLY OFFSHORE...SO THINK WINDS WILL NOT BE QUITE AS
STRONG OVER THE NEAR SHORE WATERS. THINK A SMALL CRAFT ADVISORY
WILL BE SUFFICIENT. THE STRONG SOUTHERLY WINDS TO CONTINUE THROUGH
THU. A TRAILING COLD FRONT TO MOVE THROUGH THE WATERS LATE THU
NIGHT INTO EARLY FRI MORNING. EXPECT WINDS TO SWITCH TO
SOUTHWESTERLY AND DROP OFF CONSIDERABLY BEHIND THE FRONTAL
PASSAGE. ANOTHER LOW PRES SYSTEM TO APPROACH THE S OREGON COAST
FRI NIGHT INTO SAT...BUT CURRENTLY EXPECT THIS SYSTEM WILL NOT
HAVE MUCH IMPACT FOR THE S WASHINGTON AND N OREGON COASTAL WATERS.
HIGH PRES BUILDS OVER THE WATERS FOR THE LATE WEEKEND AND EARLY
NEXT WEEK.
SEAS HAVE CONTINUED TO BE A FOOT OR TWO LOWER THAN GUIDANCE...BUT
REMAIN IN THE LOW TEENS. WILL SEE SEAS INCREASE LATER THIS
AFTERNOON AND THIS EVENING AS WINDS PICK UP...BUILDING INTO THE
MID TEENS TONIGHT AND LIKELY PEAKING IN THE UPPER TEENS LATE
THURSDAY. SEAS SUBSIDE BACK TO THE MID TEENS BY FRIDAY AND LOOK TO
FALL BELOW 10 FT SOMETIME THIS WEEKEND. PYLE
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...GALE WARNING UNTIL 10 PM PST THURSDAY FOR WATERS FROM CAPE
SHOALWATER WA TO CASCADE HEAD OR FROM 10 TO 60 NM-WATERS
FROM CASCADE HEAD TO FLORENCE OR FROM 10 TO 60 NM.
SMALL CRAFT ADVISORY FOR WINDS UNTIL 10 PM PST THURSDAY FOR
COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR
OUT 10 NM.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 PM PST
THURSDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE
OR OUT 10 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 4 PM PST
THURSDAY.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
Area Forecast Discussion
National Weather Service Spokane WA
242 PM PST WED JAN 20 2016
.SYNOPSIS...
A slow moving frontal system will bring locally heavy snow to the
Cascades and the Methow Valley tonight into Thursday. The front
will gradually move through eastern Washington and north Idaho on
Friday bringing light rain. Saturday will also feature the
potential for rain and mountain snow. High pressure should produce
mainly dry conditions Sunday and Monday before more valley rain
and mountain snow returns Tuesday.
&&
.DISCUSSION...
...HEAVY MOUNTAIN SNOW AND WINTRY MIX EAST SLOPES OF CASCADES
TONIGHT THROUGH FRIDAY MORNING...
Tonight through Friday morning: Satellite imagery shows the next
weather system knocking on our doorstep. The upper level low
pressure circulation is located out at 50N 135W in the Gulf of
Alaska. This low pressure system is tapping into a sub-tropical
moisture plume that extends out to the Hawaiian Islands. The
upper level trough will continue to dig as it approaches the
region. This will act to orient the moisture plume more
meridionally more along the western coast line. The warm front
currently pushing its way into northwest OR with light rain being
observed on radar along the coast. This front is progged to reach
the northern Cascades between 8:00 and 10:00 PM this evening based
off the latest HRRR guidance. Much of the region will see at least
a chance for some light precipitation as the front crosses eastern
WA and into the ID Panhandle overnight.
A southeasterly pressure gradient will strengthen overnight. This
will result in some downsloping off of the Northeast Blue Mtns and
off of the higher terrain in the ID Panhandle. I anticipate that
that this will act to hinder much precipitation from actually
reaching the ground across the Palouse, into the Lewiston-
Clarkston Vly and up on the Camas Prairie. Generally only some
light precipitation is anticipated with the warm front across much
of eastern WA and in the ID Panhandle.
Areas that will benefit from the easterly gradient will be the
East Slopes of the Northern Cascades. The combination of moist
isentropic ascent and orographics should keep these areas wet.
Snow levels are going to be very tricky with this system.
Valleys that saw some sun across this area this afternoon should
have a difficult time cooling back down below freezing overnight.
Higher clouds are already moving in and this should act to keep
this warmer air from radiating completely away. However, the
Okanogan Valley and Methow Valley continue to see low clouds,
which has kept their temperatures down in the low 30s. These
locations will see a better chance for accumulating snow;
although, I am not as confidence about the Okanogan Valley. I
think surface temperatures will be too warm for much of the
Wenatchee Area for snow to stick, especially right along the
Columbia River. I also think that Wenatchee River Valley, Entiat
River Valley and communities along Lake Chelan will have a
difficult time seeing snow accumulate. The Winter Storm Watch will
be upgraded to a Warning for heavy snow, but will largely only
includes locations below 3000 feet south of Lake Chelan. The upper
reaches of the Methow Valley will also see a good chance for heavy
snow accumulations. The warning will run from tonight and continue
into Friday morning until the cold front passes through. I also
kept a possibility for freezing rain in the east slopes of the
northern Cascades and colder pockets in the Wenatchee Area. My
confidence is low since way did see some warming today, but cannot
completely rule it out. /SVH
Friday: The frontal system hung up along the Cascades Thursday and
Thursday night will finally be shoved eastward on Friday. There
will be a good deal of deep layer moisture accompanying the front
as it moves through eastern Washington and north Idaho, but not a
lot of large scale forcing. The models hardly depict a surface low
with the weak 500mb shortwave trough...an indication of weak
forcing. So despite an abundance of moisture, precipitation
amounts will be relatively light compared to some of our recent
storm systems. Snow levels will be high Friday and Friday night
with lowland communities region-wide receiving rain. One area of
exception could be the Methow Valley where the NAM and GFS depict
a bit of cooler air trapped along the Cascades which could
contribute to light snow accumulations Friday morning.
Saturday and Sunday: Saturday has the potential to be cool and wet
as a weakening upper low moves into Oregon and falls apart. The
GFS and Canadian models sustain a weak deformation band Saturday
into Saturday night which produces a tenth to a quarter of an inch
or precipitation for eastern Washington and north Idaho. The NAM
and ECMWF split this feature suggesting lower precipitation
chances for our region Saturday. This system bears watching since
snow levels will be marginal for accumulations in the lee of the
Cascades into portions of Washington and Idaho near the Canadian
border. However, given the daytime arrival of precipitation, snow
may struggle to accumulate on roads. There is good model agreement
that Sunday will be drier with orographic snow showers mainly
limited to the mountains of the Idaho Panhandle. The sun may even
make an appearance Sunday along the east slopes of the Cascades
into portions of the Columbia Basin. /GKoch
Sunday night through Wednesday...Models are in good agreement of
an upper level ridge over the region Sunday night through Monday
night. This should result in dry conditions with areas of low
clouds and patchy fog in the valleys and Columbia Basin. The ridge
moves east on Tuesday allowing a weak short wave trough to pass
through the Inland NW bringing with it a chance for light rain and
snow. GFS Ensembles show quite a bit of spread regarding the
timing of this wave and would not be surprised to see the timing
delayed until Tuesday night or Wednesday. Models then show a
milder and wetter system for next Wednesday or Thursday. Near to
slightly above normal temperatures are expected in the extended
forecast period. JW
&&
.AVIATION...
18Z TAFS: The main aviation concern for the rest of today will be
fog and low stratus. Satellite imagery shows much of these low
clouds banked up along the periphery of the upper Columbia Basin.
This will continue to impact the KGEG, KSFF and KCOE TAF sites
as well as extend up the Okanogan Valley and valleys across NE WA
and into the ID Panhandle with IFR/MVFR conditions. KPUW should
see improving cigs through the morning and is expected to scatter
out in the afternoon. Easterly winds are also expected to scatter
out the Spokane/Coeur d`Alene corridor this evening. The focus
will then shift across the east slopes of the Cascades for
tonight. A warm front will increase precip chances at KEAT after
08Z. This precip is expected to begin as snow and should be very
wet with surface temps right around freezing. A warm tongue moving
in aloft will then increase the possibility for freezing rain
early Thursday morning, but there is uncertainty if surface temps
will be below freezing. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 34 42 36 42 33 39 / 20 50 20 60 40 50
Coeur d`Alene 33 41 35 42 33 39 / 10 50 20 70 50 50
Pullman 35 46 38 46 34 40 / 10 20 10 60 40 50
Lewiston 36 51 41 50 37 44 / 10 20 10 30 30 50
Colville 32 39 34 40 33 37 / 30 80 50 60 40 40
Sandpoint 32 38 35 40 33 38 / 20 60 20 80 60 50
Kellogg 31 40 36 40 31 36 / 10 40 20 70 60 60
Moses Lake 34 43 34 44 32 40 / 30 50 30 40 20 50
Wenatchee 34 39 35 42 31 37 / 90 90 80 90 20 50
Omak 32 36 33 39 29 35 / 70 100 80 90 20 40
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...Winter Storm Warning from 10 PM this evening to 10 AM PST Friday
for East Slopes Northern Cascades.
&&
$$
AREA FORECAST DISCUSSION
NWS SEATTLE WA
840 AM PST WED JAN 20 2016
.SYNOPSIS...AN UPPER LEVEL RIDGE WILL BRING DRIER WEATHER TO WESTERN
WASHINGTON TODAY WITH A FEW SUN BREAKS. A FRONTAL SYSTEM WILL MOVE
SLOWLY ACROSS THE REGION TONIGHT THROUGH THURSDAY NIGHT...FOR A
PERIOD OF WET WEATHER. THE FRONT WILL MOVE EAST FRIDAY...AND A WEAK
UPPER LEVEL TROUGH WILL BE OVER THE AREA THIS WEEKEND. ANOTHER FRONT
SHOULD ARRIVE EARLY NEXT WEEK.
&&
.SHORT TERM...A WEAK UPPER LEVEL RIDGE CENTERED JUST OFFSHORE AT
16Z/8 AM THIS MORNING WILL MOVE OVER W WA THIS AFTERNOON. AS
EXPECTED SOME RESIDUAL SHOWERS REMAIN OVER THE AREA. HRRR AND 12Z
GFS AGREE THAT THE SHOWERS SHOULD DISSIPATE BY AROUND MIDDAY.
THE LEADING EDGE OF AN APPROACHING WET FRONTAL SYSTEM WAS JUST
OFFSHORE THIS MORNING WITH THE COLD FRONT OUT ALONG 135W. WITH THE
LEADING EDGE OF THE HIGHER CLOUDS WAS JUST 60 NM OFFSHORE THIS
MORNING SO ANY SUN BREAKS OVER W WA ARE GOING TO HAVE TO HAPPEN
BETWEEN NOW AND MIDDAY...SINCE THE OVERCAST HIGH CLOUDS WILL
PROBABLY COVER W WA EARLY THIS AFTERNOON. MODELS AGREE THAT LIGHT
RAIN WILL SPREAD OVER THE COAST LATE THIS AFTERNOON THEN SPREAD NE
ACROSS ALL OF W WA BY 06Z/10 PM.
THE WARM FRONT FROM THIS SYSTEM WILL BRING STRONG WARM ADVECTION
WITH 40-60 KT S-SW WINDS ALOFT FROM 925MB-850MB TO W WA. THIS WILL
PRODUCE HEAVY RAIN OVER THE OLYMPICS AND N CASCADES TONIGHT THROUGH
THURSDAY NIGHT. THE WARM FRONT LOOKS LIKE IT GRADUALLY WEAKENS ON
THURSDAY...BUT STRONG LOW LEVEL WINDS AHEAD OF THE OFFSHORE COLD
FRONT WILL KEEP THE RAIN GOING THURSDAY NIGHT INTO EARLY FRIDAY
MORNING. TOTAL PRECIP OVER THE AREA TONIGHT THROUGH FRIDAY MORNING
WILL BE AROUND 3-6 INCHES OVER THE OLYMPICS AND N CASCADES WITH 0.50-
1.00 OVER THE INTERIOR LOWLANDS. SNOW LEVELS WILL RISE TO AROUND
7000 FEET BY MIDDAY THURSDAY.
WEAK AND COOL EASTERLY FLOW THROUGH THE CASCADE PASSES SHOULD ALLOW
A FEW INCHES OF LIGHT SNOW TO FALL INTO THURSDAY MORNING...BUT THE
STRONG WARMING ALOFT WILL PROBABLY OVERWHELM THE COOL EAST LOW LEVEL
FLOW FOR A CHANGE OVER TO RAIN BEFORE MIDDAY THURSDAY.
THE COLD FRONT WILL FINALLY BE PUSHED INLAND FRIDAY MORNING ALLOWING
THE RAIN TO TAPER OFF. A WEAK UPPER LEVEL RIDGE WILL MOVE OVER THE
AREA FRIDAY AFTERNOON FOR GRADUAL DRYING. KAM
.LONG TERM...PREVIOUS DISCUSSION FROM THE 236 AM AFD...AN UPPER
TROUGH WILL BE CENTERED OVER THE NORTHERN CALIFORNIA OFFSHORE WATERS
FRIDAY NIGHT AND LIFT NORTHEAST ACROSS THE PACIFIC NORTHWEST
SATURDAY AND SATURDAY NIGHT. IT SHOULD BRING SOME SHOWERS TO THE
FORECAST AREA BUT NOTHING SIGNIFICANT. THE SNOW LEVEL WILL BE 3000
TO 4000 FT. DRIER WEATHER IS LIKELY SUNDAY AND MONDAY AS AN UPPER
RIDGE PROGRESSES SLOWLY ACROSS THE REGION.
MODELS ARE IN FAIRLY GOOD AGREEMENT THAT ANOTHER FRONTAL SYSTEM
WILL BRING THE NEXT ROUND OF STEADY WIDESPREAD PRECIPITATION
MONDAY NIGHT AND TUESDAY...PROBABLY WITH SNOW LEVELS AGAIN
CLIMBING TO AROUND 6000 FT. MCDONNAL
&&
.AVIATION...WESTERLY FLOW ALOFT WILL TURN SOUTHWESTERLY LATE THIS
AFTERNOON AS A FRONT APPROACHES THE COAST. SURFACE GRADIENTS WILL
BECOME INCREASINGLY SOUTHEASTERLY. THE AIR MASS IS MOIST AND STABLE.
IT WILL DRY SOMEWHAT THIS AFTERNOON THEN BECOME INCREASINGLY MOIST
FROM THE WEST TONIGHT AS THE FRONT MOVES ONTO THE COAST.
CONDITIONS ARE QUITE VARIABLE ACROSS THE AREA THIS MORNING WITH
MAINLY MVFR CEILINGS AND SOME IFR CEILINGS IN THE INTERIOR VALLEYS.
EXPECT THE LOWER LEVELS TO DRY OUT MIDDAY AS LOW LEVEL PRESSURE
GRADIENTS BECOMING INCREASINGLY OFFSHORE. PRECIPITATION WILL MOVE IN
FROM THE WEST THIS EVENING...BUT WITH EASTERLY PRES GRADIENTS
CEILINGS AND VISIBILITY WILL START AS VFR THIS EVENING...THEN
GRADUALLY DETERIORATE ON THE OLYMPIC PENINSULA OVERNIGHT WHILE
STAYING MAINLY VFR IN THE INTERIOR.
KSEA...SEVERAL CLOUD LAYERS BELOW 4K FT THIS MORNING INCLUDING
ONE BELOW 1K FT. CONDITIONS WILL IMPROVE TO GOOD VFR AROUND
20Z. CEILINGS WILL GRADUALLY FALL TO OVC035 LATE TONIGHT WITH -RA.
WINDS WILL BE SOUTH 4-8 KT THIS MORNING AND WILL TURN TO THE EAST OR
NORTHEAST 4-7 KT AFTER ABOUT 20Z. CHB
&&
.MARINE...A STRONG FRONT WILL MOVE INTO THE COASTAL WATERS THIS
EVENING AND THEN SLOWLY MOVE INLAND TONIGHT AND THURSDAY. GALE
WARNINGS ARE IN EFFECT FOR THE COAST AND THE CENTRAL AND EASTERN
STRAIT. SMALL CRAFT ADVISORIES ARE IN EFFECT FOR THE REMAINING
WATERS EXCEPT PUGET SOUND AND HOOD CANAL.
SEAS WILL BUILD TONIGHT AND THURSDAY...BUT THE HIGHEST SEAS ON THE
ORDER OF 17 TO 19 FEET FROM THE SOUTHWEST WILL REMAIN OVER THE OUTER
WATERS AND WILL BE RELATIVELY SHORT PERIOD IN NATURE - REDUCING THE
THREAT FOR SIGNIFICANT BEACH EROSION ON THE COASTLINE.
A WEAKER SYSTEM WILL MOVE THROUGH THE WATERS FRIDAY OR FRIDAY NIGHT.
A STRONGER SYSTEM WILL MOVE BY WELL TO THE SOUTH OF THE WATERS ON
SATURDAY. CHB
&&
.HYDROLOGY...ANOTHER 3 TO 6 INCHES OF PRECIPITATION WILL FALL OVER
THE OLYMPICS TONIGHT THROUGH THURSDAY NIGHT...WITH THE SNOW LEVEL
RISING TO 6500 TO 7500 FT. THIS WILL CAUSE THE SKOKOMISH RIVER --
WHICH ONLY FELL BELOW FLOOD STAGE TUESDAY MORNING -- TO FLOOD
AGAIN. IT WILL PROBABLY BEGIN THURSDAY MORNING...AND THE ONLY
REAL QUESTION IS WHETHER OR NOT IT WILL REACH ITS MAJOR FLOOD
STAGE. THE FLOOD WATCH WILL BE UPDATED EARLY THIS MORNING.
OTHER WESTERN WASHINGTON RIVERS FLOWING OFF THE OLYMPICS AND THE
NORTH CASCADES WILL ALSO RISE SIGNIFICANTLY. HOWEVER NORTHWEST
RIVER FORECAST CENTER GUIDANCE SHOWS MOST OF THESE RIVERS -- THE
SATSOP... ELWHA...DUNGENESS...SKAGIT...AND STILLAGUAMISH --
CRESTING AT MOST WITH AROUND 70 PERCENT OF THE DISCHARGE NEEDED TO
REACH FLOOD STAGE. SO THE THREAT ON THESE RIVERS LOOKS PRETTY LOW.
THE GUIDANCE FOR THE NOOKSACK SHOWS IT GETTING CLOSEST TO FLOOD
STAGE -- THE SOUTH FORK NOOKSACK SPECIFICALLY -- BUT STILL LESS
THAN 80 PERCENT OF THE DISCHARGE CORRESPONDING TO FLOOD STAGE.
AND IT IS WORTH NOTING THAT THE NOOKSACK DID NOT FLOOD DURING
EITHER OF THE WESTERN WASHINGTON FLOODING EPISODES IN NOVEMBER AND
DECEMBER. BOTTOM LINE IS I WILL UPDATE THE FLOOD POTENTIAL OUTLOOK
TO STATE THAT FLOODING IS UNLIKELY ON RIVERS OTHER THAN THE
SKOKOMISH.
OTHERWISE...RIVER FLOODING IS NOT EXPECTED THE NEXT 7 DAYS.
MCDONNAL
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...FLOOD WATCH FROM THIS EVENING THROUGH LATE FRIDAY NIGHT FOR HOOD
CANAL AREA-LOWER CHEHALIS VALLEY AREA-OLYMPICS.
PZ...SMALL CRAFT ADVISORY COAST UNTIL 4 PM PST THIS AFTERNOON.
GALE WARNING COAST...CENTRAL AND E STRAIT FROM 4 PM THIS
AFTERNOON TO 7 PM PST THURSDAY.
SMALL CRAFT ADVISORY FOR ROUGH BAR UNTIL 7 PM PST THURSDAY FOR
GRAYS HARBOR BAR.
SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 7 PM PST THURSDAY
FOR ADMIRALTY INLET-NORTHERN INLAND WATERS INCLUDING THE
SAN JUAN ISLANDS.
SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 7 PM PST
THURSDAY FOR WEST ENTRANCE U.S. WATERS STRAIT OF JUAN DE
FUCA.
&&
$$
WWW.WEATHER.GOV/SEATTLE
YOU CAN SEE AN ILLUSTRATED VERSION OF THIS DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
540 PM CST THU JAN 21 2016
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 206 PM CST THU JAN 21 2016
MAIN FOCUS THROUGH THE PERIOD REMAINS THIS EVENING AND FIRST HALF OF
TONIGHT REGARDING SNOW POTENTIAL...WHILE ALL EYES OF COURSE FOCUS ON
WHAT CONTINUES TO SHAPE UP TO BE AN IMPRESSIVE MID ATLANTIC WINTER
STORM. EARLY AFTERNOON ANALYSIS SHOWS THE PLAYERS IN THE GAME...WITH
A PAIR OF SHORTWAVES WORKING THROUGH THE SOUTHERN/CENTRAL PLAINS AND
A RATHER ROBUST NORTHERN STREAM WAVE QUICKLY DIVING THROUGH THE
WESTERN DAKOTAS ON THE HEELS OF A 110+ KNOT JET PLOWING SOUTH OUT OF
SASKATCHEWAN. IT IS THESE FEATURES THAT WILL LINK UP TO CARVE OUT
QUITE THE CLOSED UPPER LOW OVER THE MID SOUTH STATES BY
SATURDAY...BUT OF INTEREST FOR US REMAINS THAT INCOMING NORTHERN
STREAM WAVE LATER TODAY INTO THE FIRST PART OF TONIGHT. OVERALL
FORCING AND MOISTURE REMAINS FAIRLY NEBULOUS...BUT A QUICK SHOT OF
DEEPER LAYER 290-305K UPGLIDE SHOULD HELP TO AT LEAST SUSTAIN
ONGOING LIGHT PRECIP CURRENTLY ONGOING ACROSS EASTERN SOUTH DAKOTA
AND WESTERN MINNESOTA.
HOWEVER....WE STILL HAVE QUITE A BIT OF SATURATION WORK TO
ACCOMPLISH WITH ONLY THE SUB-900MB LAYER ALREADY SATURATED (THOUGH
WITH SOME PESKY FLURRIES/LIGHT SNOW FALLING FROM SAID CLOUD DECK
WITH CLOUD TOP TEMPS AROUND -11C AND SHALLOW LIFT). SYSTEM LOOKS A
GOOD DEAL LIKE THE ONE FROM TUESDAY EVENING...WITH MUCH OF THE
ASCENT GOING INTO TOP DOWN SATURATION...THOUGH DO STILL BELIEVE WE
WILL PICK UP SOME LIGHT MEASURABLE SNOW...ESPECIALLY WEST OF THE
MISSISSIPPI. NOT LOOKING LIKE A HUGE DEAL WITH RATHER LOW RATIOS
GIVEN THE "WARM" AIRMASS... BUT A FRESH HALF TO PERHAPS ONE INCH
LOOKS DOABLE...WITH AMOUNTS LIKELY TAPERING QUICKLY TO THE EAST
GIVEN ABOVE-MENTIONED DRY AIR ISSUES.
FORCING (SUCH AS IT IS) REALLY SHUTS DOWN FAST AFTER 06Z...LEAVING
BUILDING LOW/MID LEVEL RIDGING INTO FRIDAY AND SATURDAY. LOTS OF
QUESTIONS ABOUT HOW MUCH LOW CLOUD COVER WILL STICK AROUND. GUIDANCE
REMAINS ROBUST ON CLEARING TRENDS INTO FRIDAY BUT DO HAVE SOME
CONCERNS GIVEN HOW WIDESPREAD LOWER STRATUS IS AT THE MOMENT...NOT
TO MENTION THAT WE WILL BE AGAIN BE BUILDING A DECENT INVERSION WITH
THE RIDGE ARRIVAL. THERE ARE A FEW BREAKS SHOWING UP INTO WESTERN
ONTARIO...SO IT`S NOT OUT OF THE QUESTION WE MAY SEE AT LEAST A
BRIEF WINDOW OF SOME CLEARING...BUT WITH LIGHT FLOW INTO FRIDAY
NIGHT/SATURDAY AS THE RIDGE AXIS BUILDS SQUARELY OVERHEAD...WOULD
TEND TO BELIEVE WE WILL SEE WIDESPREAD STRATUS RE-APPEAR. THAT OF
COURSE WILL MESS WITH BOTH HIGH AND LOW TEMPS...AND RIGHT OFF THE
BAT...SUSPECT WE ARE TOO COOL BOTH TONIGHT AND AGAIN FRIDAY NIGHT
(MAYBE SATURDAY NIGHT TOO). STILL LOOKING MILD ON SUNDAY AS WE BREAK
INTO THE "WARM SECTOR" AHEAD OF A NORTHERN STREAM WAVE SKIRTING THE
U.S./CANADIAN BORDER...THOUGH AGAIN SUSPECT WE WILL BE STUCK IN THE
LOW CLOUDS. FORECAST SOUNDINGS FROM THE NAM DO SUGGEST THERE COULD
BE A FEW SPITS OF SOME DRIZZLE ON SUNDAY AS WELL...THOUGH THE SETUP
DOESN`T LOOK OVERLY FAVORABLE WITH STRONGER SOUTHERLY FLOW AND
PRETTY MUCH NO LIFT THROUGH THE SATURATED LAYER.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 206 PM CST THU JAN 21 2016
LOOKING A LITTLE MORE ACTIVE TO START THE WORK WEEK WITH A RETURN TO
OUR FAMILIAR FASTER FLOW REGIME...AND WESTERN TROUGHING AT TIMES
EJECTING OUT ONTO THE PLAINS AND THEN LIFTING IN OUR DIRECTION.
GUIDANCE TRENDS THE PAST 24 HOURS CONTINUE TO SUPPORT OUR NEXT WAVE
ARRIVING LATE SUNDAY NIGHT INTO MONDAY WITH CHANCES FOR ACCUMULATING
SNOW...THOUGH OF COURSE THE EXACT DETAILS REMAIN A LITTLE MURKY
(WITH THE 21.06Z GFS PRETTY MUCH SUGGESTING A CWA SPLIT OF THE
BETTER PRECIP). STILL ANOTHER DAY OR TWO TO FIGURE OUT THE BIGGER
DETAILS...BUT FOR THE MOMENT...THIS DOESN`T LOOK LIKE A HUGE EVENT
BUT COULD PRODUCE A FEW INCHES IN SPOTS. THEREAFTER...PRETTY QUIET
MONDAY NIGHT THROUGH WEDNESDAY AS LOW LEVEL RIDGING WORKS FROM THE
PLAINS STATES THROUGH MUCH OF THE MISSISSIPPI VALLEY WITH
TIME...THOUGH WE MAY AGAIN DEAL WITH PESKY CLOUD COVER FOR PART OR
ALL OF THE TIME WITH HINTS OF MOISTURE TUCKED UP UNDER ANOTHER
SHALLOW INVERSION. COULD SEE SOME SMALLER CHANCES FOR SNOW MAKE A
RETURN TOWARD THURSDAY OR JUST BEYOND WITH ANOTHER UPPER WAVE
ROLLING DOWN THROUGH NORTHWEST FLOW ALOFT...BUT HONESTLY GIVEN JUST
HOW FAST/CHAOTIC THE PACIFIC FLOW HAS BEEN AND REMAINS...FULLY
EXPECT TIMING/PLACEMENT CHANCES TO SHORTWAVES LIKE THIS ONE OVER THE
COMING DAYS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 540 PM CST THU JAN 21 2016
A SMALL AREA OF LIGHT SNOW OVER SOUTHWEST MINNESOTA LATE THIS
AFTERNOON IN ASSOCIATION WITH A SHORT WAVE TROUGH WORKING
SOUTHEAST ACROSS THE DAKOTAS. THE 21.18Z NAM CONTINUES THE TREND
OF TAKING THE BEST FORCING FROM THIS WAVE TO THE SOUTHWEST OF THE
AREA. THE FORECAST SOUNDINGS SHOW A DRY MID LEVEL IN PLACE OVER
THE AREA AND THE 21.18Z KDVN SOUNDING CONFIRMED THIS. THE CONCERN
BECOMES WHETHER THE FORCING IS STRONG ENOUGH TO OVERCOME THIS DRY
AIR AND ALLOW THE LIGHT SNOW TO MOVE INTO THE AREA. THE NAM SHOWS
MUCH LESS SNOW MOVING IN THAN PREVIOUS MODEL RUNS AND IS ALSO MUCH
SLOWER. THE 21.21Z RAP STILL BRINGS SOME LIGHT SNOW INTO KRST THIS
EVENING BUT DOES GET THE SNOW OVER TO KLSE. WILL SPLIT THE
DIFFERENCES BETWEEN THESE TWO MODELS AND SHOW SOME LIGHT SNOW FOR
KRST WITH JUST SOME FLURRIES FOR KLSE. CEILINGS LOOK TO REMAIN
IFR/MVFR THROUGH THE NIGHT AND THE CONCERN THEN BECOMES WHETHER
THESE CLOUDS WILL SCATTER OUT FRIDAY. AS THE SURFACE HIGH BUILDS
IN FRIDAY...THE FLOW REMAINS PRETTY WEAK SO THERE WILL NOT BE A
STRONG PUSH TO CLEAN OUT THE LOW LEVEL MOISTURE AND THIS COULD
KEEP THE CLOUDS IN PLACE LIKE THE NAM SUGGESTS. WITH SATELLITE AND
SURFACE OBSERVATIONS SHOWING LOTS OF CLOUDS UP STREAM INTO THE
RIDGE AXIS...WILL REMAIN ON THE PESSIMISTIC SIDE AND KEEP THE MVFR
CLOUDS IN THROUGH FRIDAY AFTERNOON.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...LAWRENCE
LONG TERM...LAWRENCE
AVIATION...04
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
335 AM EST FRI JAN 22 2016
.DISCUSSION...
...FAST MOVING SQUALL LINE TODAY WITH SLIGHT RISK OF STRONG-
SEVERE STORMS...
...WINDY AND MUCH COLDER SATURDAY WITH A FREEZE THREAT AND LOW
WIND CHILLS EARLY SUNDAY MORNING...
TODAY...A LOW PRESSURE CENTER OVER ALABAMA WILL DRIFT NORTH THEN
A SECONDARY LOW WILL INTENSIFY NEAR THE CAROLINA COAST LATE IN THE
DAY. THE ASSOCIATED STRONG COLD FRONT WILL MOVE QUICKLY EAST
ACROSS THE GULF OF MEXICO THIS MORNING AND SWEEP OFF THE EAST
CENTRAL FLORIDA COAST BY EARLY EVENING. A SQUALL LINE THAT
EXTENDED QUITE FAR SOUTH INTO THE GULF WAS OCCURRING JUST AHEAD OF
THE FRONT. IT HAS BEEN MOVING EAST 30-35 KNOTS. THE LATEST HRRR
MODEL SHOWS A SIMILAR MOVEMENT...SO EXPECT THE SQUALL LINE TO
REACH LAKE COUNTY NEAR MIDDAY AND PUSH OFF THE TREASURE COAST LATE
IN THE AFTERNOON.
DEEP LAYER SHEAR WILL INCREASE THIS MORNING AND 925-850MB WINDS
ARE STILL FORECAST 35-45 KNOTS. LOW LEVEL WINDS SHOULD STAY BACKED
ENOUGH TO MAINTAIN GOOD LOW LEVEL CONVERGENCE AHEAD OF THE FRONT THIS
MORNING...THEN EXPECT VEERING THIS AFTERNOON AND THE SOUTHERN
PORTION OF THE LINE SHOULD START TO WEAKEN. INSTABILITY WILL BE
LIMITED WITH ONLY A BRIEF WINDOW OF TIME AVAILABLE FOR DAYTIME
DESTABILIZATION WITH MODEST HEATING AND DEW POINT RECOVERY.
HOWEVER...THE HRRR MODEL HAS BEEN MAINTAINING A LIGHTNING THREAT AS
THE SQUALL LINE MOVES ACROSS THE AREA...WHICH SUGGESTS THERE WILL
BE ENOUGH INSTABILITY FOR ISOLATED STRONG-SEVERE STORMS. THE
PRIMARY THREAT WILL BE DAMAGING STRAIGHT LINE WIND GUSTS WITH THE
SQUALL LINE...BUT CANNOT RULE OUT AN ISOLATED TORNADO WITHIN
BOWING SEGMENTS OF THE LINE.
TONIGHT...THE COLD FRONT WILL SWEEP EAST OF THE STATE BY EARLY
EVENING. BREEZY TO WINDY CONDITIONS ARE EXPECTED BEHIND THE FRONT
WITH TIGHT PRESSURE GRADIENT AS DEEPENING LOW MOVES NORTHEAST
ALONG THE CAROLINA COAST. STEEP LOW LEVEL LAPSE RATES IN THE WAKE
OF THE COLD FRONT WILL SUPPORT LOW TOPPED CONVECTION IN THE
GULF...AND WITH A STRONG LOW LEVEL WIND FIELD...THERE IS A SLIGHT
CHANCE FOR THESE SHOWERS TO PUSH WELL INLAND OVERNIGHT. IT WILL
TURN SHARPLY COLDER AROUND SUNSET...BUT THE WEST FLOW OFF THE GULF
WILL LIMIT THE EFFECTS OF STRONG COLD ADVECTION DURING THE
OVERNIGHT. LOW TEMPS WILL DROP INTO THE MID 40S NORTH TO MID 50S
FAR SOUTH.
SAT-SUN...THE STRONG LOW PRESSURE CENTER EAST OF NORFOLK VA/VACAPES
LIFTS NORTHEAST OVER THE ATLANTIC THROUGH SUNDAY. A VERY TIGHT
PRESSURE GRADIENT WILL EXIST ACROSS THE AREA SATURDAY IN THE WAKE OF
THE LOW WITH WINDY CONDITIONS EXPECTED ACROSS THE AREA SATURDAY.
CURRENT WIND FORECAST FOR SATURDAY INDICATES THAT A WIND ADVISORY
WILL MOST LIKELY BE NEEDED FOR MUCH OF THE AREA.
HIGH PRESSURE OVER THE LOWER MISSISSIPPI RIVER VALLEY BUILDS ACROSS
THE SOUTHEAST U.S. AND INTO FLORIDA. NORTHWEST TO NORTH WINDS ADVECT
A DRY AND COLDER AIRMASS INTO FLORIDA SATURDAY AND SUNDAY. HIGHS
SATURDAY TO BE IN THE 50S TO LOW 60S. THE 22/00Z GUIDANCE SUGGESTING
A LITTLE MORE COLD AIR ADVECTION SATURDAY NIGHT WITH LOWS IN MOST
AREAS IN THE LOW AND MID 30S EXCEPT FOR THE COAST FORT PIERCE
SOUTH AND MARTIN COUNTY. THE COMBINATION OF THESE COLD
TEMPERATURES AND NORTHWEST WINDS AT 10 TO 15 MPH SHOULD PRODUCE
WIND CHILLS IN THE MID AND UPPER 20S NORTH TO SOUTH EXCEPT THE LOW
30S SAINT LUCIE AND MARTIN COUNTIES.
A SLIGHT WARM UP ON SUNDAY WITH HIGHS RANGING FROM THE MID 50S NORTH
AND WEST OF INTERSTATE 4 TO AROUND 60/LOW 60S OKEECHOBEE...SAINT
LUCIE AND MARTIN COUNTIES. LOWS MONDAY MORNING EXPECTED TO RANGE
FROM THE UPPER 30S INTERIOR AND WEST OF INTERSTATE 95 TO THE LOW 40S
AT THE COAST SOUTH BREVARD TO MARTIN COUNTY.
MON-FRI...UPPER LEVEL RIDGE OVER THE SOUTHEAST MONDAY SHIFTS INTO
THE WESTERN ATLANTIC TUESDAY AND BEYOND AS A TROUGH OVER THE ROCKIES
DIGS SOUTH AS IT MOVES EASTWARD ACROSS THE SOUTHERN PLAINS AND INTO
THE SOUTHEAST U.S. BY THURSDAY. TROUGH AXIS CLEARS FLORIDA PENINSULA
FRIDAY. AT THE SURFACE...HIGH PRESSURE OVER THE SOUTHEAST U.S.
SHIFTS INTO THE WESTERN ATLANTIC MONDAY AND TUESDAY. SOUTHEAST FLOW
MONDAY SHIFTS TO THE SOUTH TUESDAY AND THE SOUTHWEST WEDNESDAY AND
THURSDAY AS TROUGHING OVER THE LOWER MISSISSIPPI RIVER VALLEY MOVE
SLOWLY INTO THE SOUTHEAST STATES. MOISTURE VALUES BEGIN A SLOW
RECOVERY MONDAY AND TUESDAY REACHING AN INCH AND A HALF/1.5 INCHES
OR MORE WEDNESDAY AND THURSDAY. IMPULSES/DISTURBANCES IN THE
SOUTHWEST FLOW ALOFT TRIGGER WEAK SURFACE LOWS THAT MOVE NORTHEAST
OVER FLORIDA THROUGH WEDNESDAY. STRONG ENOUGH IMPULSE MOVES THROUGH
THURSDAY TRIGGERING A SURFACE LOW OFF THE SOUTHWEST AND WEST FLORIDA
COAST OVERNIGHT WEDNESDAY. THE LOW MOVES QUICKLY TO THE NORTHEAST
ACROSS THE FLORIDA PENINSULA THURSDAY AND IS EAST OF THE CAROLINAS
FRIDAY NIGHT. WEDNESDAY AND THURSDAY BEST OPPORTUNITY FOR RAIN.
FRONT CLEARS FLORIDA OVERNIGHT THURSDAY AND HIGH PRESSURE BUILDS IN
FROM THE NORTHWEST(SOUTHEAST U.S.) FRIDAY. LOWS IN THE 50S AND LOW
60S THROUGH THURSDAY THEN BACK INTO THE 40S FRIDAY MORNING IN THE
NORTHWEST FLOW BEHIND THE FRONT.
&&
.AVIATION...
IT WILL BE ANOTHER DAY WITH FAST CHANGING CONDITIONS. EARLY
MORNING VFR WILL GIVE WAY TO A BRIEF PERIOD WITH MVFR-IFR AS A
FAST MOVING SQUALL LINE MOVES THROUGH. EXPECT ISOLATED LIGHTNING
STRIKES AND A CHANCE FOR WIND GUSTS OVER 40 KNOTS WITH THE LINE.
A COLD FRONT WILL MOVE THROUGH DURING THE AFTERNOON AND GUSTY
WESTERLY WINDS TO 25 KNOTS ARE EXPECTED...WHICH MAY OCCUR
INTERMITTENTLY INTO THE OVERNIGHT HOURS.
&&
.MARINE...
TODAY-TONIGHT...INTENSIFYING LOW PRESSURE OVER THE DEEP SOUTH TO
CAROLINA COAST WILL SWING A STRONG COLD FRONT EAST OF THE COASTAL
WATERS THIS EVENING. INCREASING SOUTHERLY WINDS TODAY HAS PROMPTED
A SMALL CRAFT ADVISORY. ADDITIONALLY...A FAST MOVING SQUALL LINE
WILL MOVE ACROSS THE WATERS THIS AFTERNOON...SO SMALL CRAFT
OPERATION IS DEFINITELY NOT ADVISED TODAY.
BEHIND THE FRONT...WE EXPECT FREQUENT GUSTS TO GALE FORCE IN THE
OPEN ATLANTIC...SO HAVE UPGRADED TO A GALE WARNING FOR THE
OFFSHORE WATERS STARTING THIS EVENING.
SAT-SUN...VERY HAZARDOUS BOATING CONDITIONS THROUGH SAT NIGHT WITH A
TIGHT PRESSURE GRADIENT IN THE WAKE OF THE LOW...PRODUCING WESTERLY
WINDS UP TO 25-30 KNOTS OFFSHORE WITH FREQUENT GUSTS TO GALE
FORCE. THIS WILL BUILD SEAS UP TO 9 TO 12 FEET OFFSHORE. A SMALL
CRAFT ADVISORY FOR THE NEARSHORE WATERS EXTENDS THROUGH SAT NIGHT
WITH A GALE WARING OFFSHORE.
BOATING CONDITIONS WILL REMAIN POOR-HAZARDOUS THROUGH SUNDAY
MORNING THEN WIND SPEEDS WILL DROP OFF CONSIDERABLY IN THE
AFTERNOON.
MON-TUE...GREATLY IMPROVED BOATING CONDITIONS ARE FORECAST WITH HIGH
PRESSURE PROVIDING LIGHTER WINDS MON...BUT IT WILL BE VERY CHILLY IN
THE MORNING. WINDS WILL REMAIN ON THE LIGHTER SIDE INTO MON
NIGHT/TUE...BUT MODELS INDICATE AN INCREASING SWELL UP TO 6 FEET
OFFSHORE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 73 45 55 34 / 90 20 10 10
MCO 74 49 58 36 / 90 20 10 10
MLB 76 50 61 34 / 90 20 10 10
VRB 77 53 63 36 / 80 20 10 10
LEE 71 46 56 33 / 90 20 10 0
SFB 73 47 55 35 / 90 20 10 10
ORL 73 48 57 36 / 90 20 10 10
FPR 77 53 64 36 / 80 20 10 10
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY UNTIL 4 AM EST SUNDAY FOR FLAGLER BEACH TO
VOLUSIA-BREVARD COUNTY LINE 0-20 NM-SEBASTIAN INLET TO
JUPITER INLET 0-20 NM-VOLUSIA-BREVARD COUNTY LINE TO
SEBASTIAN INLET 0-20 NM.
SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR FLAGLER
BEACH TO VOLUSIA-BREVARD COUNTY LINE 20-60 NM-SEBASTIAN
INLET TO JUPITER INLET 20-60 NM-VOLUSIA-BREVARD COUNTY LINE
TO SEBASTIAN INLET 20-60 NM.
GALE WARNING FROM 7 PM THIS EVENING TO 4 AM EST SUNDAY FOR
FLAGLER BEACH TO VOLUSIA-BREVARD COUNTY LINE 20-60 NM-
SEBASTIAN INLET TO JUPITER INLET 20-60 NM-VOLUSIA-BREVARD
COUNTY LINE TO SEBASTIAN INLET 20-60 NM.
&&
$$
SHORT TERM...LASCODY
LONG TERM....WIMMER
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
330 AM CST FRI JAN 22 2016
.SHORT TERM...(Today)
ISSUED AT 329 AM CST FRI JAN 22 2016
The storm system that will affect the East Coast over the next
several days was gathering strength over western Alabama as of 2am.
The precipitation shield associated with the storm was pushing into
extreme southern Illinois with models continuing to suggest the bulk
of the snow will stay just south of Lawrenceville today. Will
continue to hang on to at least slight chance wording in our far
southeast counties to account for any northward shift in the precip
today, however, forecast soundings and time-height cross sections
showing quite a bit of dry air from 925-800 my layer so if the snow
is able to make it to the surface, it will be on the light side with
the more significant accumulating snowfall remaining south.
Further north, a weak shortwave seen on the water vapor loop over
the Great Lakes will shift southeast today with the main forecast
concern with that feature being a large deck of stratus along and
to the north of the trof axis in addition to some scattered flurries.
May see the lower deck gradually work its way south into the
forecast area during the day today but most of the short term models
indicate any light snow or flurries with the upper wave will remain
to our west and north today. Something to keep an eye on in the
short term with both the HRRR and RAP models indicating the north to
northeasterly flow off of Lake Michigan may push some flurries
southwest to parts of north-central Illinois this afternoon. Not
much of a big diurnal shift in temperatures today due to the cloud
cover with most areas in the upper 20s to lower 30s this afternoon.
&&
.LONG TERM...(Tonight through Thursday)
ISSUED AT 329 AM CST FRI JAN 22 2016
Strong low pressure to deepen and move off the NC coast overnight
with its snow mainly along and se of the Ohio river pulling further
away from southeast IL, while clouds begin to decrease from the nw
during overnight. Breezy north winds to continue tonight especially
in eastern IL closer to strong low pressure near the NC coast. Lows
tonight in the upper teens central IL and lower 20s se of I-70.
With Nor`easter off the mid Atlantic and New England coast Saturday
and Saturday night bringing a major winter storm to mid Atlantic
states and southern New England, quiet weather expected for IL this
weekend. Mostly sunny skies Saturday over central and southeast IL
with surface ridge over the MS river valley by sunset Saturday and
as upper level ridge shifts east into IL by Sunday. Highs mostly in
the lower 30s Saturday with NNW winds keeping it cool. Temps modify
Sunday into the mid 30s to around 40F with increasing south winds
on Sunday along with some increase clouds over central IL.
A storm system off the West Coast to bring an upper level trof east
into IL by Monday evening while weak surface low pressure tracks
from the OK panhandle at sunset Sunday into ne IL by sunday Monday.
Still dry Sunday night with light precipitation spreading east over
IL during the day Monday. 00Z models have trended slower with
arrival of this weather system, so think surface temps will be above
freezing by time precipitation starts. Monday looks warm enough to
support mainly light rain with chance of light snow over northern
CWA Monday morning and far NW CWA by Knox and Stark counties Monday
afternoon with little or no accumulations. Above normal highs Monday
in the upper 30s/lower 40s.
A bit cooler air moves in behind a cold front during Monday night as
light rain changes to light snow before diminishing to flurries and
linger into Tue with upper level trof over the Great lakes and into
IL. Any snowfall amounts appear quite light if they occur Monday
night generally less than a half inch. Highs Tue around 30F northern
CWA to near 35F far se IL along and south of highway 50. Weak high
pressure near IL Wed with dry conditions and partly sunny skies with
highs mostly in the lower 30s. 00Z models have trended further nne
with northern stream short wave/clipper system on Thu where brunt of
light snow chances pass ne of central IL with just slight chances
for central and ne CWA. Temps to modify back into mid to upper 30s
Thu and a few degrees milder next Friday in upper 30s/lower 40s.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
ISSUED AT 1132 PM CST THU JAN 21 2016
VFR conditions at all central IL terminals this evening with
overcast mid-upper level cloud cover and wind NE up to 10 kts.
Cloud cover and winds will continue most of the night helping to
prevent fog formation...however thin fog/haze is widespread with
visibilities generally 6-8SM. A shortwave approaching from the
northern Plains/upper Midwest should increase lower ceilings from
15-18Z so have included MVFR cigs of 3000 feet at that point.
Winds N-NE up to 15 kts will continue for the remainder of the
24-hour TAF forecast period.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Smith
LONG TERM...07
AVIATION...Onton
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1152 PM CST THU JAN 21 2016
.UPDATE...920 PM CST
THE GOING FORECAST FOR TONIGHT IS IN GENERALLY GOOD SHAPE AND
CONTINUE TO ASSESS LAKE EFFECT SNOW SHOWER COVERAGE AND INTENSITY
FOR FRIDAY MORNING...NEITHER OF WHICH LOOK IMPRESSIVE...ALTHOUGH
THE TIMING OF A WEEKDAY MORNING COMMUTE CAN LOWER THRESHOLDS FOR
IMPACTS.
THE LOW-LEVEL RIDGE AXIS DRAPED FROM WEST TO EAST OVER THE
FORECAST AREA HAS STRENGTHENED THIS EVENING NOW AVERAGING AROUND
1030MB. THE 850-925MB BAROCLINIC ZONE IS DEVELOPING SOUTHWARD OVER
THE LAKE...THOUGH THE COLD ADVECTION PUSH IS NOT PARTICULARLY
STRONG...AND LAKE EFFECT SHOWERS ARE PRESENTLY LOOSELY DEFINED
OVER THE NORTHERN PART OF THE LAKE. THE 00Z APX SOUNDING INDICATED
AN INVERSION HEIGHT AROUND 7500 FT OVER NORTHERN LOWER MICHIGAN
WHICH CAN BE INFERRED OVER THE NORTHERN PART OF THE LAKE RIGHT
NOW...ALTHOUGH THIS WILL LIKELY MODIFY SOME AS IT ADVANCES
SOUTHWARD. BOTH THE RAP AND NAM SEEMED TO ANALYZE WELL WITH WHAT
WAS GOING ON UPSTREAM AND HAVE INVERSION HEIGHTS AROUND 4500-5000
FT OVER THE FAR SOUTHWEST PART OF THE LAKE FRIDAY MORNING. BESIDES
LIMITING THE OVERALL INSTABILITY AND VERTICAL MOTION FOR MODERATE-
HEAVY SNOW...THIS FAIRLY LOW INVERSION HEIGHT ALSO APPEARS TO KEEP
THE TEMPERATURE PROFILES SATURATED ONLY AS COOL AS -10C...WHICH IS
NOT OPTIMUM FOR SNOW GROWTH. THERE STILL IS ENOUGH SUPPORT FOR
MAINLY LIGHT SNOW SHOWERS HOWEVER ESPECIALLY GIVEN THE CONVERGENCE
SET TO DEVELOP ACROSS THE WESTERN PART OF THE LAKE AS THE LOW
PRESSURE OVER THE LOWER MISSISSIPPI VALLEY LIFTS NORTH AND BENDS
THE PRESSURE FIELD.
SO CONTINUE THE TRENDS AS IS WITH JUST MINOR ADJUSTMENTS IN HOURLY
FORECAST PARAMETERS. THE PRIMARY TIME FOR LIGHT LAKE EFFECT SNOW
IN DOWNTOWN CHICAGO APPEARS TO BE BETWEEN 7 AM AND NOON...WHILE IN
LAKE COUNTY ILLINOIS APPEARS TO BE BETWEEN 9 AM AND 3 PM. WITH
THE MARGINAL INTENSITY EXPECTED AND AIR TEMPERATURES EXPECTED TO
BE IN THE MID TO POSSIBLY UPPER 20S...THINK IMPACTS WILL OVERALL
STILL BE MINIMAL...WITH ACCUMULATION PRIMARILY OF A FEW TENTHS OR
LESS...WITH EASTERN LAKE COUNTY AND IMMEDIATE LAKE SIDE AREAS
POSSIBLY A LITTLE HIGHER BY LATE MORNING.
MTF
&&
.SHORT TERM...
157 PM CST
THROUGH FRIDAY...
TONIGHT...
FAIRLY QUIET CONDITIONS ARE IN PLACE THIS AFTERNOON AS A BROAD AREA
OF SURFACE HIGH PRESSURE HOLDS ON THE NORTH SIDE OF CLOSED UPPER
LEVEL LOW PRESSURE. TEMPERATURES ARE STILL SLIGHTLY BELOW NORMAL
WITH LIGHT WINDS. SOME MID LEVEL MOISTURE AHEAD OF THE NORTHERN
STREAM SHORTWAVE WILL APPROACH THE AREA FROM THE WEST
TONIGHT...THOUGH ANY FLURRIES WILL LIKELY REMAIN TO OUR WEST/NORTH.
TEMPERATURES SHOULD HOLD A BIT HIGHER TONIGHT AS A MIX OF MID AND
UPPER CLOUDS KEEP READINGS INTO THE UPPER TEENS MANY LOCATIONS TO
THE 20S IN THE CITY.
FRIDAY...
THE LARGE MID-UPPER LEVEL LOW TO OUR SOUTH...THE ONE THAT WILL BRING
SNOW TO PORTIONS OF THE EAST COAST...WILL TRANSLATE ACROSS THE
EASTERN HALF OF THE UNITED STATES. WEAKER ENERGY ON THE NORTH SIDE
OF THIS SYSTEM WILL TRANSLATE ACROSS NORTHEAST ILLINOIS AND
NORTHWEST INDIANA THROUGH THE DAY. THE CLOSED LOW EXTENDING TO THE
SURFACE...LOW LEVEL WINDS TURN NORTHEASTERLY CREATING A SETUP FOR
LAKE EFFECT SNOW SHOWERS...MOST FAVORED IN THE MORNING TO EARLY
AFTERNOON. PARAMETERS FAVORABLE INCLUDE MARGINALLY STEEP LAPSE RATES
ALONG WITH IN EXCESS OF 100 J/KG OF LAKE INDUCED CAPE...A PERIOD OF
LOW LEVEL CONVERGENCE COUPLED WITH THE UPPER WAVE RESULTING IN
MODEST LOWER LEVEL OMEGA. NEGATIVE FACTORS INCLUDE A VERY NARROW
AXIS OF SATURATION IN THE DENDRITIC GROWTH REGION AT THE TOP OF THE
SATURATED LAYER AND A SEMI-PROGRESSIVE CONVERGENCE AXIS SUGGESTING
SHOWERS WILL NOT LINGER. WE DO CARRY SOME LIKELY POPS FROM CHICAGO
NORTHWARD INTO LAKE COUNTY AS WE FEEL THERE WILL BE SOME LAKE EFFECT
SHOWERS AROUND WITH SOME LIGHT ACCUMULATIONS WHERE THEY OCCUR...BUT
KEPT CHANCE MENTIONS OR FLURRIES ELSEWHERE DUE TO THESE NEGATIVE
FACTORS. RAW GUIDANCE SUGGESTS A FEW TENTHS AT BEST...COULD BE
LOCALLY SLIGHTLY HIGHER WHERE SHOWERS SET UP WITH NOT EVERYWHERE
ACCUMULATING...TYPICAL OF MARGINAL LAKE EFFECT SCENARIOS. STILL CAN
MAKE FOR SOME LOCALLY SLICK ROADS. OTHERWISE EXPECT LAKE CLOUDS AND
TEMPS IN THE MID TO UPPER 20S...STILL SLIGHTLY COOLER THAN NORMAL.
KMD
&&
.LONG TERM...
258 PM CST
FRIDAY NIGHT THROUGH THURSDAY...
MAIN FORECAST CONCERNS/CHALLENGES ARE WITH LINGERING LAKE EFFECT
SNOW SHOWERS FRIDAY EVENING...AND THEN WINTRY MIX/SNOW BECOMING
MORE PROBABLE MONDAY AND MONDAY NIGHT.
SCATTERED LAKE EFFECT SNOW SHOWERS MAY STILL BE OCCURRING ACROSS
A PORTION OF FAR NORTHEAST ILLINOIS...PRIMARILY COOK/LAKE
COUNTIES...FRIDAY EVENING. NORTHEAST FLOW OFF OF THE LAKE WITH
PARAMETERS BECOMING SLIGHTLY MORE FAVORABLE FOR DEVELOPMENT WILL
OCCUR DURING THIS PERIOD AND HAVE MADE LITTLE CHANGES TO THE
SLIGHT CHANCE/CHANCE POPS DURING THIS TIME. ANY ACCUMULATION WILL
BE ISOLATED AND LIGHT...WITH AT MOST A TRACE UP TO A COUPLE OF
TENTHS OF AN INCH POSSIBLE. ANY REMAINING SNOW SHOWERS WILL
DIMINISH OVERNIGHT INTO SATURDAY MORNING. MAINTAINED A DRY
FORECAST FOR SATURDAY MORNING...BUT COULD SEE SOME FLURRIES
POSSIBLY STILL COMING OFF THE LAKE FOR A TIME. HOWEVER...RIDGING
ALOFT AND EASTWARD BUILDING HIGH PRESSURE WILL LIMIT ANY FURTHER
DEVELOPMENT INTO SATURDAY. SKIES WILL LIKELY BE SCATTERING ON
SATURDAY WHILE WARMING OCCURS ALOFT. THIS COINCIDING WITH RATHER
LIGHT WINDS SHOULD ALLOW FOR A RELATIVELY PLEASANT DAY ON
SATURDAY. DRY CONDITIONS AND WARMING WILL CONTINUE THROUGH THE END
OF THE WEEKEND WITH TEMPS IN THE MID TO UPPER 30S EXPECTED SUNDAY.
CLOUD COVER WILL BE INCREASING SUNDAY AND SUNDAY NIGHT IN ADVANCE
OF THE NEXT SYSTEM TO IMPACT THE REGION. GUIDANCE FAIRLY
CONSISTENT IN SHOWING A FAIRLY ENERGETIC UPPER LEVEL TROUGH AND
ATTENDANT SURFACE LOW PUSHING THROUGH THE PLAINS AND MID
MISSISSIPPI VALLEY SUNDAY INTO MONDAY. PRECIP CHANCES WILL BE
INCREASING FROM WEST TO EAST OVER THE CWA ON MONDAY AS THIS SYSTEM
APPROACHES...WITH SOME CONCERNS FOR POSSIBLE VARYING PRECIP TYPE
REMAINING. DEEPER MOISTURE DOES NOT APPEAR TO BE PRESENT ACROSS
THE CWA INITIALLY ON MONDAY AND WITH THERMAL PROFILES ALSO CLOSE
TO THE RAIN/SNOW LINE...AM A LITTLE CONCERNED FOR A PERIOD OF
FREEZING RAIN/DRIZZLE. HOWEVER...STRONGER FORCING WILL LIKELY NOT
ARRIVE UNTIL LATER IN THE DAY...WITH SURFACE TEMPS HAVING A DECENT
CHANCE TO RISE ABOVE FREEZING BEFORE THIS PRECIP ARRIVES. WILL
CONTINUE TO MONITOR THIS POTENTIAL BUT HAVE LEFT OUT ANY MENTION
OF FREEZING RAIN/DRIZZLE IN THE GRIDS AT THIS TIME. COLD AIR
SHOULD QUICKLY WRAP AROUND THIS SYSTEM AS IT MOVES THROUGH THE
CWA/REGION MONDAY NIGHT WITH ANY LIQUID PRECIP QUICKLY CHANGING
OVER TO ALL SNOW DURING THAT TIME. CONFIDENCE IS LOWER TO THE
EXTENT OF ANY REMAINING MOISTURE ON THE BACKSIDE OF THIS SYSTEM
MONDAY NIGHT INTO TUESDAY BUT ITS POSSIBLE FOR SOME SNOW
ACCUMULATION...ESPECIALLY AS SNOW SHOWERS WILL STILL BE POSSIBLE
ON TUESDAY.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* MVFR CIGS DEVELOPING...PATCHY IFR CIGS WEST OF ORD/MDW.
* PERIOD OF LIGHT SNOW BETWEEN 14Z AND 20Z...WITH THE STEADIER
SNOW ARRIVING BETWEEN 15-17Z.
* VSBYS WITH STEADIER SNOW COULD DIP TO ARND 3SM.
* WINDS TURNING NORTHEAST AT 010-030 AND INCREASING WITH SPEEDS
BETWEEN 10-14KT AND GUSTS UP TO 20KT THROUGH THE AFTN.
BEACHLER
//DISCUSSION...UPDATED 06Z...
IR IMAGERY SHOWS CONSIDERABLE CLOUDS TO THE SOUTH OF THE TAF SITES
ACROSS CENTRAL INDIANA AND ALSO ANOTHER AREA UPSTREAM OVER
MINNESOTA. ACROSS NORTHERN IL/NORTHWEST IN CLOUDS ARE ABOVE 10KFT
AGL...HOWEVER THERE IS SOME THIN SPOTS OF MVFR CIGS DEVELOPING AND
GUIDANCE CONTINUES TO INDICATE THAT THIS WILL CONTINUE TO DEVELOP
ACROSS THE REGION OVER THE NEXT FEW HOURS...AND BY 8Z MANY OF THE
TAF SITES WILL HAVE CIGS AROUND 1800-2500FT AGL. WINDS ARE ALSO
EXPECTED TO SLOWLY TURN NORTHEAST TO 010-030 DIRECTION AND THE
GRADIENT WILL ALSO INCREASE. SPEEDS WILL GENERALLY BE BETWEEN
10-14KT WITH GUSTS NEARING 20KT BY MIDDAY.
IN ADDITION TO THE CLOUDS AND WINDS...THERE MAY BE A WINDOW OF
LIGHT SNOW DEVELOP OFF OF LAKE MICHIGAN. THE MOST FAVORABLE TIME
WILL BE BETWEEN 14Z AND 20Z...WITH STEADIER SNOW FALLING BETWEEN
15-17Z. THIS COULD BRING VSBYS DOWN TO ARND 2-3SM...BUT SNOW WILL
END AND VSBYS IMPROVE BY 20Z.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE IN WIND DIR/SPEED/GUSTS...LOW CONFIDENCE IN
PRECISE TIMING OF WINDS GOING NORTHEAST.
* HIGH CONFIDENCE IN MVFR CIGS DEVELOPING...MEDIUM ON TIMING AND
DURATION.
* MEDIUM CONFIDENCE IN LIGHT SNOW DEVELOPING AND LOW ON PRECISE
TIMING. HIGH CONFIDENCE IN SNOW ENDING BEFORE 23Z.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z...
* SATURDAY...DRY/VFR. LIGHT WINDS.
* SUNDAY...DRY. MVFR POSSIBLE. SOUTHWEST WINDS.
* MONDAY...CHANCE OF RAIN/SNOW. MVFR LIKELY. IFR POSSIBLE.
SOUTHERLY WINDS.
* TUESDAY...CHANCE OF SNOW/MVFR. IFR POSSIBLE. GUSTY WESTERLY
WINDS.
* WEDNESDAY...DRY. MVFR POSSIBLE. SOUTHWESTERLY WINDS.
&&
.MARINE...
258 PM CST
GENERALLY LIGHTER WINDS OVER THE LAKE CONTINUING THIS AFTERNOON
AS HIGH PRESSURE SPANS MUCH OF THE GREAT LAKES REGION TODAY.
HOWEVER...THIS HIGH WILL SHIFT EAST THROUGH FRIDAY MORNING WHILE
DEVELOPING LOW PRESSURE SHIFTS EAST ACROSS THE GULF COAST STATES
TONIGHT INTO FRIDAY. THIS WILL ALLOW THE WINDS TO BECOME MORE
ORGANIZED OUT OF THE NORTH TONIGHT...AND THEN INCREASE TO THE 15
TO 25 KT RANGE OUT OF THE NORTH/NORTHEAST FRIDAY ACROSS THE ENTIRE
LAKE. WAVES WILL BUILD DURING THIS TIME WITH WAVES ACROSS THE
NEARSHORE APPROACHING SMALL CRAFT ADVISORY CONDITIONS...FOR ICE
FREE AREAS. AS THIS LOW PUSHES FURTHER AWAY FROM THE REGION THE
GRADIENT OVER THE LAKE DOES RELAX WITH WINDS DIMINISHING FRIDAY
NIGHT INTO SATURDAY MORNING. HOWEVER...LOW PRESSURE WILL MOVE FROM
ONTARIO TO QUEBEC SATURDAY INTO SATURDAY NIGHT AND AS THIS
OCCURS...EXPECT WINDS TO BECOME MORE SOUTHERLY AND INCREASING TO
THE 30KT RANGE SATURDAY NIGHT.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS WICHITA KS
341 AM CST FRI JAN 22 2016
.SYNOPSIS...
ISSUED AT 340 AM CST FRI JAN 22 2016
D-E-E-P UPPER-DECK TROF UNDERGOING CYCLOGENESIS CONTINUED DIGGING
OVER THE AR/LA BORDER DURING THE NIGHT WITH IT`S ATTENDANT SFC LOW
DEVELOPING OVER THE MS/AL BORDER. THIS IS KEEPING ALL OF CENTRAL &
EASTERN KS IN A "MODERATE" N/NE REGIME. A SOMEWHAT UNORTHODOX DRY
SLOT IS KNIFING ALMOST DUE S ACROSS EASTERN KS THAT`LL TEAM WITH
SNOW FIELD TO ENABLE TEMPERATURES ACROSS NORTHEAST & EAST-CENTRAL
KS TO NOSEDIVE EARLY THIS MORNING THUS SHARPENING THE E-W GRADIENT
EARLY THIS MORNING.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 340 AM CST FRI JAN 22 2016
TODAY & TONIGHT:
THE GREATEST ISSUE IS HOW THE STRATUS WILL BEHAVE. THE LOWER-DECK
CYCLONE...THAT IS SITUATED OVER THE MS/AL BORDER VERY EARLY THIS
MORNING...SHOULD GET FORCED SLOWLY E/NE ACROSS THE AL/TN BORDER
THIS AFTERNOON AS A HIGH-AMPLITUDE RIDGE PUNCHES NE FROM AZ/NM
TOWARD THE NORTHERN PLAINS. THE NAM...RUC & HRRR ALL KEEP A SHARP
900-850MB INVERSION OVER ALL OF THE CWA THRU LATE THIS AFTERNOON.
THE NAM SHARPENS THE INVERSION TONIGHT WHICH WOULD LIKELY KEEP THE
NEIGHBORHOOD STRATIFIED THIS EVENING. AS SUCH WILL HAVE MOST...IF
NOT ALL...OF KICT COUNTRY UNDER A LOW OVERCAST THRU EARLY THIS
EVENING. THIS OF COURSE WOULD HAVE RAMIFICATIONS ON TEMPERATURES.
(ESPECIALLY ALONG THE NE CORRIDOR.) FOR THE MOST PART HAVE
FOLLOWED THE CONSALL & SUPERBLEND SOLUTIONS. WITH THE AFORE-
MENTIONED POSITIVELY-TILTED RIDGE AXIS SHIFTING E SKIES SHOULD
CLEAR W-E TO ENABLE TEMPERATURES TO TUMBLE. DID UNDERCUT GUIDANCE
ALONG NE SECTOR WHERE SNOW FIELD WOULD NO DOUBT ASSIST THE
CLEARING SKIES & WINDS THAT`LL BECOME LIGHT & VARIABLE WITH THE
TEMPERATURE DROP.
THIS WEEKEND:
WARMER WEATHER IS STILL SCHEDULED TO ARRIVE AS THE ABOVE-MENTIONED
MID-UPPER RIDGE DEAMPLIFIES & SPREADS E ACROSS THE CENTRAL THIRD
OF THE CONUS SAT & SAT NIGHT. A DEEP...COMPACT CYCLONE THAT HAS
BEEN APPROACHING THE NORTHERN CA/OR COAST DURING THE NIGHT WILL
QUICKLY TRANSITION INTO AN OPEN WAVE AS IT CROSSES AS IT CROSSES
THIS SECTION OF THE COAST LATE TONIGHT & SAT. IT`LL GRADUALLY
RESTRENGTHEN AS IT CROSSES THE ROCKIES ON SUN THEN ACROSS THE
CENTRAL & SOUTHERN PLAINS SUNDAY NIGHT. THIS WOULD SWEEP A COLD
FRONT SE ACROSS KS SUNDAY NIGHT. SOME POST FRONTAL PRECIPITATION
(LIGHT SNOW) IS POSSIBLE ACROSS CENTRAL KS LATE SUNDAY NIGHT. THE
RAPIDLY PROGRESSIVE PATTERN SHOULD KEEP CHANCES FOR ACCUMULATION
IN CHECK.
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 340 AM CST FRI JAN 22 2016
MON:
AS THE CONTINUALLY STRENGTHENING UPPER-DECK WAVE SURGES E TOWARD
THE MS VALLEY ALL PRECIPITATION SHOULD QUICKLY END. TEMPERATURE
PROFILES DEPICT PRIMARILY LIGHT RAIN FOR SOUTHEAST KS.
MON NIGHT-THU:
A CYCLONE WILL APPROACH HUDSON BAY MON NIGHT & RAPIDLY INTENSIFY
AS IT CROSSES HUDSON BAY TUE & TUE NIGHT. THE CYCLONE WILL KICK A
S-H-A-R-P POSITIVELY-TILTED MID-UPPER LONG-WAVE SE ACROSS THE
GREAT PLAINS TUE NIGHT...HOWEVER IT`S SFC COHORT APPEARS TO KEEP
THE CENTRAL & SOUTHERN PLAINS IN A PREDOMINANTLY NW COMPONENT TO
KEEP TEMPERATURES ON THE MILD SIDE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1129 PM CST THU JAN 21 2016
CEILINGS VARIED GREATLY ACROSS CENTRAL AND SOUTHEAST AT LATE
EVENING...RANGING FROM LIFR IN KRSL TO VFR AT KCNU. WHILE SOME
VARIABILITY WILL CONTINUE ALONG AND EAST OF THE TURNPIKE THRU
09Z...THE GENERAL TREND IS FOR SOMEWHAT MORE UNIFORM CIGS IN THE
LOW MVFR OR IFR CATEGORIES LATE TONIGHT. THE LOWEST VSBYS WITH
SOME FREEZING FOG SHOULD REMAIN ACROSS THE HIGHER TERRAIN IN
CENTRAL KANSAS. A GRADUAL AND GENERAL IMPROVEMENT TO VFR SHOULD
COMMENCE BY MIDDAY INTO THE AFTERNOON ON FRIDAY.
KED
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 32 17 43 29 / 0 0 0 0
HUTCHINSON 31 15 42 28 / 0 0 0 0
NEWTON 30 15 40 28 / 0 0 0 0
ELDORADO 31 15 40 29 / 0 0 0 0
WINFIELD-KWLD 33 17 43 30 / 0 0 0 0
RUSSELL 30 17 42 26 / 0 0 0 0
GREAT BEND 32 17 43 27 / 0 0 0 0
SALINA 29 13 35 28 / 0 0 0 0
MCPHERSON 30 14 40 28 / 0 0 0 0
COFFEYVILLE 34 18 41 29 / 10 0 0 0
CHANUTE 32 16 38 28 / 10 0 0 0
IOLA 31 16 37 28 / 10 0 0 0
PARSONS-KPPF 34 17 40 28 / 10 0 0 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
National Weather Service Paducah KY
352 AM CST FRI JAN 22 2016
.SHORT TERM...(Today through Sunday)
Issued at 352 AM CST FRI JAN 22 2016
According to dual pol radar data it appears that much of the
Warning area has changed over to snow, with the exception of
Calloway county eastward along the Tennessee border. A change over
to all snow is expected over those areas by 12Z. The Winter Storm
Warning is looking pretty good, and no changes are planned at
this time. Snow amounts over much of west Kentucky may be just a
bit higher with a max now of around 12" in Muhlenberg, Christian
and Todd counties.
The problem areas for the snow forecast continue to be the
northwest periphery of the existing warning area. The Evansville
area southwest to Hardin county may not quite reach Warning
criteria of 4", but there may be an area of more advisory level
snows from Alexander county through Johnson and into Saline and
Gallatin counties. Radar is currently showing some increase in
that region and recent HRRR runs are showing the precipitation
shield reaching those areas now. Not sure if it will last long
enough to warrant an Advisory, so for now will just keep an eye
out for observations from those regions and adjust as needed.
Latest radar trends indicate that southeast Missouri outside of
New Madrid and Mississippi counties has dried out as expected.
Will let the Warning and Advisory expire as scheduled at 12Z. May
need to extend Alexander and Pulaski for awhile, but will make
that decision near 12Z. Hopefully, we will have enough
observations by then to decide if the Advisory needs to be
expanded to the northeast any at all.
It appears that much of the measurable precipitation will be done
by 00Z, but will leave the 06Z expiration of the primary portion
of the Warning. However, we will likely be cancelling it in chunks
this afternoon, as the snow comes to an end from west to east.
Skies will clear Saturday, but temperatures will struggle to climb
above freezing, especially over the snowpack. The surface high
will settle over the region Saturday night, so some single digit
lows are expected, especially over the Pennyrile. Wouln`t be
surprised if a few locations approach 0. South winds will try to
bring a warm up on Sunday, but with the snowpack hanging around,
it may be muted compared to the MAV guidance.
.LONG TERM...(Sunday Night through Thursday)
Issued at 352 AM CST FRI JAN 22 2016
By Sunday night, an upper level ridge will be centered overhead with
sfc high pressure continuing to move east of the area. South winds
at the surface will continue to pick up as a storm system over the
central Plains moves east northeast. By 12Z Monday, a sfc low will
be located over the KS/MO border. Throughout the day on Monday, the
sfc low will move northeast toward the western Great Lakes region.
As this occurs, a cold front will move across our area from west to
east. As has been the case for the last few days...models are not
showing too much QPF with this system, as the best moisture is
confined to the north with the actual sfc low. However, we will
continue to maintain low chance POPS with the FROPA. Soundings and
time height charts indicate temperatures are warm enough for
precipitation to fall as rain, at least during the day.
Heading into Monday evening, models differ a bit on the timing of
when exactly the front will clear the CWA. However, will continue to
linger precipitation into the evening/overnight hours, however
believe that any lingering activity should probably be mainly during
the evening. Low level temperature profiles indicate that there
could be a rain/snow mix up in our northern counties. This blends
well with neighboring offices to our north.
Since moisture seems to be lacking on Tuesday, despite the fact that
an upper level trough will be moving through the area, will only
keep low POPS for the eastern sections. Any moisture will be
confined to the low levels, centered around 925mb, so some flurries
would be possible if anything occurred at all.
High pressure builds into the area Tuesday night into Wednesday
providing dry weather. A clipper type system approaches us from the
northwest on Wednesday night into Thursday but should only bring us
some clouds.
&&
.AVIATION...
Issued at 525 PM CST THU JAN 21 2016
Conditions will deteroriate after 06z (FZRA/SN) from SW to NE
across the area, with mainly snow by 10-12z on through Friday.
Best coverage will be south of a line from KOWB to KPOF. MVFR to
occasional IFR conditions expeced, along with a substantial
increase in winds later tonight through Friday, generally NNE
15-30 kts.
&&
.PAH Watches/Warnings/Advisories...
IL...Winter Weather Advisory until 6 AM CST early this morning for
ILZ092-093.
Winter Storm Warning until midnight CST tonight for ILZ090-091-
094.
MO...Winter Weather Advisory until 6 AM CST early this morning for
MOZ086-087-100-107-111.
Winter Storm Warning until midnight CST tonight for MOZ112-114.
Winter Storm Warning until 6 AM CST early this morning for
MOZ108>110.
IN...Winter Storm Warning until midnight CST tonight for INZ086>088.
KY...Winter Storm Warning until midnight CST tonight for KYZ001>022.
&&
$$
SHORT TERM...DRS
LONG TERM...CW
AREA FORECAST DISCUSSION
NWS JACKSON KY
423 AM EST FRI JAN 22 2016
.UPDATE...
ISSUED AT 1144 PM EST THU JAN 21 2016
BLENDED OBS INTO THE FORECAST GRIDS AGAIN...WITH ONLY MINOR
CHANGES. WILL LEAVE ANY SIGNIFICANT CHANGES BASED ON THE 00Z RUNS
TO THE NEWLY ARRIVED MID SHIFT. IT IS INTERESTING TO NOTE THE NAM
SHOWING CONVECTIVE SNOW FRIDAY EVENING OVER SE KY AND THE INTENSE
SNOWFALL RATES WHICH RESULT. THE GFS IS FURTHER SOUTH WITH THIS
FEATURE. CONFIDENCE IN A SMALL...ALBEIT SIGNIFICANT...FEATURE SUCH
AS THIS IS NOT HIGH...BUT ITS MODEL EXISTENCE POINTS TO THE
POTENTIAL.
UPDATE ISSUED AT 829 PM EST THU JAN 21 2016
MADE ONLY MINOR CHANGES TO THE PREVIOUS FORECAST BY BLENDING IN
OBS. THE MOST SUBSTANTIAL CHANGE WAS A FASTER INCREASE IN CLOUDS
THIS EVENING.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY EVENING)
ISSUED AT 456 PM EST THU JAN 21 2016
...DANGEROUS TRAVEL CONDITIONS EXPECTED FRIDAY AND SATURDAY...
A STRONG CLOSED UPPER LEVEL LOW WILL MOVE TOWARDS OUR AREA
OVERNIGHT TONIGHT AS IT DEEPENS RAPIDLY. THIS LOW WILL SHIFT
NORTHEAST AND ACROSS THE SOUTHERN TN VALLEY BY SATURDAY AFTERNOON.
THE ASSOCIATED SFC LOW WILL TAKE A SIMILAR TRACK ACROSS THE LOWER
TN VALLEY AND OFF THE EAST COAST SATURDAY AFTERNOON. BOTH THE NAM
AND GFS ARE IN GOOD AGREEMENT SO HAVE TRENDED TOWARD A BLEND OF
THESE MODELS IN THE SHORT TERM.
PRECIPITATION TYPE IS TRICKY REGARDING THIS SYSTEM AS MODEL
SOUNDINGS ARE TRENDING TOWARDS COLDER TEMPERATURES REMAINING
GENERALLY BELOW FREEZING THROUGH THE COLUMN. SOUNDINGS DO SHOW A
WEAK WARM NOSE AT THE ONSET OF THE EVENT MAINLY IN THE SOUTHERN
HALF OF THE FORECAST AREA. THIS IS WHERE THERE IS A CHANCE FOR A
MIXED BAG OF PRECIP INCLUDING...SLEET...FREEZING RAIN...RAIN AND
SNOW. HOWEVER...FURTHER NORTH...PRECIP SHOULD BE ALL SNOW...AND
ESPECIALLY GIVEN THE FACT THAT TEMPERATURES THIS AFTERNOON DIDN/T
WARM AS MUCH AS MODELS INDICATED...IS FURTHER PROOF THAT IT WILL
BE COLD ENOUGH TO SNOW. ALL PRECIP SHOULD CHANGE OVER TO SNOW
AROUND 1 PM TOMORROW WITH HEAVY SNOW POSSIBLE AT TIMES THROUGH
SATURDAY AFTERNOON. A WIDE SWATH OF TOTAL SNOW ACCUMULATIONS OF
12 TO 17 INCHES IS POSSIBLE ACROSS THE NORTHERN HALF OF THE
FORECAST AREA. SNOW ACCUMULATIONS IN THE SOUTHERN COUNTIES WILL
LIKELY BE LIMITED TO 4 TO 8 INCHES DUE TO THE MIXING OF
RAIN/FREEZING RAIN. THAT BEING SAID...THESE AMOUNTS COULD QUICKLY
CHANGE DEPENDING ON THE TEMPERATURES AND IF THE WARM NOSE COMES IN
MORE PRONOUNCED. SO STAY ABREAST TO THE WEATHER OVER THE NEXT 12
HOURS FOR ANY CHANGES THAT MAY OCCUR.
DRIVING CONDITIONS WILL BE TREACHEROUS SO PLEASE STAY OFF THE
ROADS IF POSSIBLE. IF NOT...MAKE SURE TO HAVE AN EMERGENCY KIT IN
YOUR CAR.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 423 AM EST FRI JAN 22 2016
THE EXTENDED FORECAST PERIOD BEGINS ON SATURDAY NIGHT WITH A
PROGRESSIVE AND ACTIVE UPPER LEVEL PATTERN. DURING THIS TIME A
STRONG CLOSED UPPER LOW IS EXITING THE REGION INTO THE MIDDLE
ATLANTIC AREA. DURING THIS TIME...SOME WRAP AROUND MOISTURE STILL
LINGERS INTO EASTERN KENTUCKY WHERE SOME SNOW SHOWERS WILL LINGER
THROUGH MUCH OF SATURDAY NIGHT BEFORE FINALLY EXITING BY SUNDAY
MORNING. WITH CLOUD COVER DECREASING AND A LARGE SNOWPACK OVER THE
AREA...MORNING TEMPERATURES SUNDAY MORNING WILL FALL INTO THE
SINGLEDIGITS. DURING THE DAY ON SUNDAY AND THROUGH MONDAY
AFTERNOON...A NUPPER LEVEL RIDGE WILL KEEP THE AREA DRY.
BY MONDAY NIGHT...A FAST MOVING SYSTEM DEEP TROUGH WILL BRING
MOREPRECIP INTO THE AREA. WARMER SURFACE TEMPERATURES MAY KEEP
MOST OF THE PRECIP AS RAIN BUT WILL LIKELY SEE SOME SNOW MIX IN
MONDAY NIGHT INTO TUESDAY ESPECIALLY IN THE HIGHER ELEVATIONS. A
COLDER AIR MASS WILL MOVE IN BEHIND THIS FRONT AS A PERIOD OF
UPSLOPE SNOW SHOWERS IS ANTICIPATED. WITH MOISTURE ON THE
DECREASE AS THIS FEATURE EXITS...SNOW WILL COME TO AN END BY
WEDNESDAY EVENING. WITH THE AREA CONTINUING TO BE IN NORTHWEST
FLOW INTO THURSDAY...ANOTHER FAST MOVING SYSTEM WILL BRING ANOTHER
SHOT OF MOISTURE INTO THE AREA. THUS WILL PUT IN ANOTHER ROUND OF
SNOW SHOWERS. THESE WAVES ARE A BIT MOISTURE STARVED SO NOT
EXPECTING MUCH ACCUMULATION RIGHT AT THIS TIME. THE ONE FACTOR
THAT COULD MEAN SLIGHTLY MORE SNOW IS HOW THE MODELS HANDLE ANY
SNOW PACK ON THE GROUND HEADING INTO THESE WEAKER WAVES.
OVERALL...THE EXTENDED IS CERTAINLY LESS ACTIVE THAN THE SHORT
TERM.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1257 AM EST FRI JAN 22 2016
IT IS THE CALM BEFORE THE STORM...WITH VFR AREA WIDE TO START THE
PERIOD. PRECIPITATION IS STARTING TO NOSE ITS WAY INTO SOUTHERN
KY...AND WILL SPREAD NORTH OVER THE REGION LATE TONIGHT AND
FRIDAY MORNING...ACCOMPANIED BY MAINLY IFR AND LIFR CONDITIONS.
POOR CONDITIONS SHOULD THEN PERSIST THROUGH THE REMAINDER OF THE
PERIOD. THE PRECIPITATION WILL INITIALLY BE A MIXED BAG OF WINTER
WEATHER IN THE SOUTHERN PART OF THE JKL FORECAST AREA...BUT WILL
TRANSITION TO MAINLY SNOW ON FRIDAY AFTERNOON. IN THE NORTH...IT
SHOULD BE MAINLY SNOW THROUGHOUT THE EVENT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 7 PM EST SATURDAY FOR KYZ044-050>052-
060-104-106-107-119.
WINTER STORM WARNING UNTIL 7 PM EST SATURDAY FOR KYZ058-059-068-
069-079-080-083>088-108>118-120.
&&
$$
UPDATE...HAL
SHORT TERM...JVM
LONG TERM...SHALLENBERGER
AVIATION...JMW
[top]
Area Forecast Discussion
National Weather Service Louisville KY
402 AM EST FRI JAN 22 2016
.SHORT TERM (Now through Saturday)...
Issued at 400 AM EST Fri Jan 22 2016
...WINTER STORM TO AFFECT THE AREA TODAY THROUGH SATURDAY MORNING...
...SIGNIFICANT SNOW AND SOME ICE ACCUMULATIONS EXPECTED ACROSS THE
REGION...
...DANGEROUS TRAVEL CONDITIONS EXPECTED TODAY INTO SATURDAY
MORNING...
SYNOPTIC OVERVIEW
=================
A strong PV anomaly is rounding the base of a southern stream trough
this morning, whose ascent has helped foster a deepening surface low
which is currently analyzed over portions of northern Alabama. This
will lift northeast through the day today and into tonight.
All the ingredients are coming together for a major winter storm today
into tonight across the Ohio Valley. A coupled jet structure, with a
strong anticyclonically-curved 125+ knot jet noted over northern IN/OH
has led to very strong moisture transport from the Gulf of Mexico into
TN and southern KY this morning. This moisture is being fed above a
cold dome at the surface which has led to freezing rain this morning
over southern KY. This TROWAL will continue to wrap northwest on the
northwest side of this deepening cyclone today, helping to tighten the
mid-level thermal gradient and increase forcing for ascent later this
morning into this afternoon across the region. This deep, moist
forcing will result in widespread precipitation moving through KY and
portions of southern IN today.
MODEL PREFERENCE
=================
The HRRR has had a very good handle on the current situation, thus have
leaned heavily on that solution for the next 6-9 hours. Beyond that,
blended HRRR guidance more with a mix of the hi-res WRF-ARW and NAM
fields. This led to an overall increase in the QPF across much of
central and south-central KY. Hi-res guidance was preferred as it
should handle the banded/convective nature of this snowfall that we are
likely to see.
SENSIBLE WEATHER AND IMPACTS
============================
As mentioned above, freezing rain has already accumulated from a glaze
up to a tenth of an inch across portions of southern KY, especially
near the BWG area. This is the result of the warm nose from the
moisture transport to the south nudging into the region. However,
recent reports and CC data out of HPX is showing the thermal profile is
rapidly crashing as cold air is wrapped into this system from the
northwest. Therefore, expect precip to quickly transition to snow from
the northwest across south-central KY this morning, with most areas
going all snow by around 12/13Z. Before this transition occurs, there
could be up to 0.3" of ice across roughly our southern two tiers of
counties in KY.
Further north, while some sleet may mix in at onset before the column
evaporatively cools, think any precip will quickly go to snow. Forecast
cross sections depict deep omega within the dendridic growth zone, with
negative EPV values suggesting CSI and soundings even suggesting some
very weak convective instability as well. These values being above the
strong f-gen circulation suggest banding of snowfall is very likely to
occur, with the most preferred area across south central-KY near the
Parkways (where amounts have been upped). A rumble of thunder is not
completely out of the question in these heavier bands, as snowfall
rates will likely exceed 2 inches per hour for periods of time.
Along the Ohio River, uncertainty still remains. It appears the
expected strong gradient is going to set up very near the river, which
will obviously have massive impacts on amounts especially for the
Louisville metro. For now, will mainly continue with the going
forecast, but this is still subject to shift today as the bands set up.
AMOUNTS AND CONFIDENCE
======================
Have high confidence in a band of over a foot of snowfall setting up
across portions of central KY, likely between the Parkways. It is here
where the forecast cross-sections and instability fields are showing
the potential for a potent band of snowfall to set up. Would not be
surprised at all to see amounts locally in excess of 18 inches come out
of this band. This localized band will likely include southern
portions of the LEX metro.
25-30 miles on either side of this band, have fairly high confidence in
a swath of 8-12 inches. This would include areas like Bowling Green to
Glasgow, the north of the band into E-Town and Frankfort.
Have only low/medium confidence in areas to the north of this along the
Ohio River. As mentioned above, this is going to be a tight gradient
where the edge of the strong synoptic forcing/def band is battling dry
air to the north. Will keep in a gradient of 4-8 inches across this
region, which includes the Louisville metro. This gradient is likely
going to need to be tightened and fine-tuned through the day today.
Across our northern tier of counties in southern IN, have high
confidence in only a trace to locally 3 inches in this region. The dry
air will win out here for the most part.
Winds will gust around 35 mph today which will cause reductions in
visibility in the heaviest snowfall areas, along with some scattered
power outages especially across south-central KY where some icing is
expected to occur (we`ve already had some reports of outages down there
this morning). Some drifting of snow is also likely to occur given
these winds.
.LONG TERM (Saturday Night through Thursday)...
Issued at 300 AM EST Fri Jan 22 2016
Deep closed low off the eastern US coast will continue to lift out
Saturday night and Sunday while mid-level ridging builds across our
region. This will lead to dry conditions across the region Saturday
night through Sunday night. Main challenge in this period will be
overnight temperatures. We expect to have a decent snowpack on the
ground early in the period. That combined with clearing skies and
light winds will yield cold temperatures. The blended guidance is
trending downward but is not capturing the latest raw data yet.
Therefore, have gone well below guidance across much of region.
We`re likely to see very low single digit to single digit below zero
readings Saturday night and Sunday morning. Temperatures will
recover a bit on Sunday with mostly sunny skies. However, plan on
uttercutting guidance over the snowpack. Highs will range from the
low 30s over less covered areas to mid-upper 20s across the
snowpack. That may be a bit generous, but will continue to monitor
trends over the next few days. We`ll start to get a southwesterly
flow Sunday night as the high moves off to the east coast. This
should keep temperatures a bit warmer with lows mainly in the upper
teens to lower 20s.
Still looking at a progressive pattern aloft for the new work week
with an upper trough swinging through the region Monday and Monday
night. This system still looks to tap into some gulf moisture and
will bring rain showers to the region. With continued warm
advection, we should see temperatures above freezing, but guidance
is probably going to be overdone here with the melting snowpack.
We`ll need to continue to watch this time frame for p-type issues
because if low level temps remain cold enough we could have mixed
precip.
Once the surface feature moves through, upper trof hangs back from
the Great Lakes down through the Mississippi Valley, so we`ll stay a
bit unsettled with with below normal temps, plenty of cloud cover,
and small chances for a few light rain or snow showers especially in
the Thursday to Friday time frame.
&&
.AVIATION (06Z TAF Update)...
Updated at 1150 PM EST Thu Jan 21 2016
Impactful Winter Storm expected to begin overnight at BWG, then
spreading northward to SDF/LEX by Friday morning. Highest confidence
in worst conditions at LEX/BWG, SDF will be on the northern fringes
of the storm but should still see impacts. Will break down
timing/conditions below.
BWG...
Onset: Now
P-TYPE: -FZRA initially to Mix of -FZRA/IP/SN,
then all Snow after 7 AM CST.
Heaviest: 7 AM CST to end of TAF time
Conditions: low MVFR/IFR ceilings and visibility during lighter
snow, Minimums during heavy snow.
Winds: Steady NE overnight, increasing in magnitude to 10 to 15,
gust 25 mph Friday. Blowing/drifting snow possible.
SDF...
Onset: Around 7 AM EST
P-TYPE: All snow
Heaviest: 1 PM EST to 5 PM EST
Conditions: low MVFR/IFR ceilings and visibility during lighter
snow, low IFR/near minimums during heavier snow.
Winds: Steady NE overnight, increasing in magnitude to 10 to 15,
gusts 25-30 mph Friday. Blowing/Drifting snow possible.
LEX...
Onset: Around 8 AM EST
P-TYPE: All snow
Heaviest: Noon EST to end of TAF time
Conditions: low MVFR/IFR ceilings and visibility
during lighter snow, minimums in heavier snow.
Winds: Steady NE overnight, increasing in magnitude to 10 to 15,
gusts 25-35 mph Friday. Blowing/Drifting snow possible.
&&
.LMK Watches/Warnings/Advisories...
KY...Winter Storm Warning until 7 AM EST /6 AM CST/ Saturday for
KYZ024-026>029-034>043-045>049-053>057-061>067-070>078-081-
082.
Winter Storm Warning until 7 AM EST /6 AM CST/ Saturday for
KYZ023-025-030>033.
IN...Winter Weather Advisory until 7 AM EST /6 AM CST/ Saturday for
INZ076>079-083.
Winter Storm Warning until 7 AM EST /6 AM CST/ Saturday for
INZ084-089>092.
&&
$$
Short Term........KJD
Long Term.........MJ
Aviation..........AMS
AREA FORECAST DISCUSSION
NWS JACKSON KY
1257 AM EST FRI JAN 22 2016
.UPDATE...
ISSUED AT 1144 PM EST THU JAN 21 2016
BLENDED OBS INTO THE FORECAST GRIDS AGAIN...WITH ONLY MINOR
CHANGES. WILL LEAVE ANY SIGNIFICANT CHANGES BASED ON THE 00Z RUNS
TO THE NEWLY ARRIVED MID SHIFT. IT IS INTERESTING TO NOTE THE NAM
SHOWING CONVECTIVE SNOW FRIDAY EVENING OVER SE KY AND THE INTENSE
SNOWFALL RATES WHICH RESULT. THE GFS IS FURTHER SOUTH WITH THIS
FEATURE. CONFIDENCE IN A SMALL...ALBEIT SIGNIFICANT...FEATURE SUCH
AS THIS IS NOT HIGH...BUT ITS MODEL EXISTENCE POINTS TO THE
POTENTIAL.
UPDATE ISSUED AT 829 PM EST THU JAN 21 2016
MADE ONLY MINOR CHANGES TO THE PREVIOUS FORECAST BY BLENDING IN
OBS. THE MOST SUBSTANTIAL CHANGE WAS A FASTER INCREASE IN CLOUDS
THIS EVENING.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY EVENING)
ISSUED AT 456 PM EST THU JAN 21 2016
...DANGEROUS TRAVEL CONDITIONS EXPECTED FRIDAY AND SATURDAY...
A STRONG CLOSED UPPER LEVEL LOW WILL MOVE TOWARDS OUR AREA
OVERNIGHT TONIGHT AS IT DEEPENS RAPIDLY. THIS LOW WILL SHIFT
NORTHEAST AND ACROSS THE SOUTHERN TN VALLEY BY SATURDAY AFTERNOON.
THE ASSOCIATED SFC LOW WILL TAKE A SIMILAR TRACK ACROSS THE LOWER
TN VALLEY AND OFF THE EAST COAST SATURDAY AFTERNOON. BOTH THE NAM
AND GFS ARE IN GOOD AGREEMENT SO HAVE TRENDED TOWARD A BLEND OF
THESE MODELS IN THE SHORT TERM.
PRECIPITATION TYPE IS TRICKY REGARDING THIS SYSTEM AS MODEL
SOUNDINGS ARE TRENDING TOWARDS COLDER TEMPERATURES REMAINING
GENERALLY BELOW FREEZING THROUGH THE COLUMN. SOUNDINGS DO SHOW A
WEAK WARM NOSE AT THE ONSET OF THE EVENT MAINLY IN THE SOUTHERN
HALF OF THE FORECAST AREA. THIS IS WHERE THERE IS A CHANCE FOR A
MIXED BAG OF PRECIP INCLUDING...SLEET...FREEZING RAIN...RAIN AND
SNOW. HOWEVER...FURTHER NORTH...PRECIP SHOULD BE ALL SNOW...AND
ESPECIALLY GIVEN THE FACT THAT TEMPERATURES THIS AFTERNOON DIDN/T
WARM AS MUCH AS MODELS INDICATED...IS FURTHER PROOF THAT IT WILL
BE COLD ENOUGH TO SNOW. ALL PRECIP SHOULD CHANGE OVER TO SNOW
AROUND 1 PM TOMORROW WITH HEAVY SNOW POSSIBLE AT TIMES THROUGH
SATURDAY AFTERNOON. A WIDE SWATH OF TOTAL SNOW ACCUMULATIONS OF
12 TO 17 INCHES IS POSSIBLE ACROSS THE NORTHERN HALF OF THE
FORECAST AREA. SNOW ACCUMULATIONS IN THE SOUTHERN COUNTIES WILL
LIKELY BE LIMITED TO 4 TO 8 INCHES DUE TO THE MIXING OF
RAIN/FREEZING RAIN. THAT BEING SAID...THESE AMOUNTS COULD QUICKLY
CHANGE DEPENDING ON THE TEMPERATURES AND IF THE WARM NOSE COMES IN
MORE PRONOUNCED. SO STAY ABREAST TO THE WEATHER OVER THE NEXT 12
HOURS FOR ANY CHANGES THAT MAY OCCUR.
DRIVING CONDITIONS WILL BE TREACHEROUS SO PLEASE STAY OFF THE
ROADS IF POSSIBLE. IF NOT...MAKE SURE TO HAVE AN EMERGENCY KIT IN
YOUR CAR.
.LONG TERM...(FRIDAY EVENING THROUGH THURSDAY)
ISSUED AT 456 PM EST THU JAN 21 2016
PRECIPITATION WILL BE FALLING AS ALL SNOW BY FRIDAY EVENING NORTH OF
THE CORE OF THE SYSTEM...WITH SOME OF THIS CONTINUING TO BE OF THE
HEAVIER VARIETY. DURATION AND INTENSITY OF THIS WILL LARGELY DEPEND
ON WHETHER ANY DEFORMATION BANDING CAN MATERIALIZE AS STOUT EARLIER
DAY DEEP LAYER OMEGA PROFILES WANE. GIVEN HOW LOCKED IN THE RECENT
MODIFIED ARCTIC AIR MASS HAS BEEN...WOULD NOT BE SURPRISED FOR
UPPER LOW TO PASS EVEN FARTHER SOUTH THAN CURRENTLY PROGGED THUS
SHUNTING ANY SIGNIFICANT DRY SLOTTING POTENTIAL EAST OF THE
BLUEGRASS STATE. LIGHT SNOW WILL CONTINUE INTO SATURDAY MORNING
AND GRADUALLY SHIFT EAST AS LARGE SCALE SUBSIDENCE BUILDS INTO THE
REGION. NOT EXPECTING TEMPERATURES TO BREACH THE FREEZING MARK
SATURDAY GIVEN THE EXPECTED SNOWPACK IN PLACE. SURFACE RIDGE
BUILDING IN SATURDAY NIGHT ON TOP OF A FRESH SNOWPACK AND IN THE
PRESENCE OF LIGHT WINDS SHOULD PROMOTE COLD TEMPERATURES BOTTOMING
OUT MAINLY IN THE LOW-MID TEENS.
RISING HEIGHTS ALOFT FOR THE LATTER HALF OF THE WEEKEND INTO NEXT
WEEK WILL FINALLY SEND TEMPERATURES ABOVE FREEZING...BUT WILL STILL
LIKELY REMAIN BELOW AVERAGE THROUGH THE NEXT SEVEN DAYS. DAMPENING
UPPER TROUGH...EXTENDING FROM CANADA WELL INTO THE MISSISSIPPI
VALLEY...WILL THEN PUSH EAST EARLY NEXT WEEK...BRINGING
PRECIPITATION POTENTIAL BACK INTO THE PICTURE BY LATER IN THE DAY ON
MONDAY. WHILE PHASE WILL INITIALLY KICKOFF AS RAIN GIVEN THE
PRESENCE OF WARM AIR ADVECTION...WILL HAVE TO WATCH APPROACH OF A
CANADIAN AIR MASS INTO TUESDAY IN TERMS OF PRECIPITATION
TRANSITIONING TO THAT OF A WINTRY TYPE BEFORE COMING TO AN END.
FOLLOWING THIS INTO MID AND LATE WEEK...CONTINUED NORTHERN STREAM
ENERGY LOOKS TO TRANSLATE ACROSS THE REGION...THEREFORE KEEPING
TEMPERATURES BELOW NORMAL AND PRECIPITATION CHANCES IN THE OFFING.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1257 AM EST FRI JAN 22 2016
IT IS THE CALM BEFORE THE STORM...WITH VFR AREA WIDE TO START THE
PERIOD. PRECIPITATION IS STARTING TO NOSE ITS WAY INTO SOUTHERN
KY...AND WILL SPREAD NORTH OVER THE REGION LATE TONIGHT AND
FRIDAY MORNING...ACCOMPANIED BY MAINLY IFR AND LIFR CONDITIONS.
POOR CONDITIONS SHOULD THEN PERSIST THROUGH THE REMAINDER OF THE
PERIOD. THE PRECIPITATION WILL INITIALLY BE A MIXED BAG OF WINTER
WEATHER IN THE SOUTHERN PART OF THE JKL FORECAST AREA...BUT WILL
TRANSITION TO MAINLY SNOW ON FRIDAY AFTERNOON. IN THE NORTH...IT
SHOULD BE MAINLY SNOW THROUGHOUT THE EVENT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING FROM 7 AM THIS MORNING TO 7 PM EST SATURDAY
FOR KYZ044-050>052-060-104-106-107-119.
WINTER STORM WARNING UNTIL 7 PM EST SATURDAY FOR KYZ058-059-068-
069-108>115-118-120.
WINTER STORM WARNING UNTIL 7 PM EST SATURDAY FOR KYZ079-080-
083>088-116-117.
&&
$$
UPDATE...HAL
SHORT TERM...JVM
LONG TERM...KAS
AVIATION...JMW
Area Forecast Discussion
National Weather Service Louisville KY
1154 PM EST THU JAN 21 2016
...Updated Aviation Discussion...
...Mesoscale Forecast Update...
Issued at 1110 PM EST Thu Jan 21 2016
Made some minor adjustments to the forecast for tonight. Slowed
down steady precip arrival according to radar trends and the latest
high-res data. Although very light spotty freezing rain has
developed over south central KY, it should be a few more hrs before
steady freezing rain mixed with sleet overspreads most of southern
KY. Logan County is the exception with steady freezing rain and a
light ice glaze already reported. This was only a very minor change
to POPs with POPs still ramping up quickly after 6z.
=========================================
Prelim 0Z Model Trends on the Winter Storm
=========================================
GFS/NAM 0Z runs are not significantly different to change the
forecast at this point. The 0Z 12km NAM shifted the heavy snow axis
a bit farther south. However, the 0Z 4km NAM is still pretty much
in line with the current forecast. The 0Z GFS backed off on QPF
amounts and snowfall totals overall.
We`re also starting to get into the range of the high-res models.
The HRRR has a pretty good handle on this system so far and is
showing a heavy snow axis from roughly Morgantown, KY to Madison, KY
so far (it`s not fully capturing the entire storm though at this
point). One thing to note in the sim. reflectivity of the 4km NAM
and HRRR is the moderate to heavy snow bands setting up tomorrow
morning. The HRRR has one closer to the Louisville Metro by mid
morning which seems a little faster than the 12km NAM. Will need to
watch the high-res models overnight to pin down any adjustments to
snowfall totals based on the high-res models.
Issued at 755 PM EST Thu Jan 21 2016
Weak isld-sct radar returns are now beginning to show up over south
central KY. Got a report of freezing rain in Adairville, KY (Logan
County). Expect precip to continue in these light patches for a few
hrs before freezing rain becomes more widespread over south central
KY by around midnight-1am. Current forecast looks on track with
the latest radar imagery and obs.
.SHORT TERM (Now through Friday Night)...
Issued at 332 PM EST Thu Jan 21 2016
...WINTER STORM TO AFFECT THE AREA LATE TONIGHT THROUGH SATURDAY...
...SIGNIFICANT SNOW AND SOME ICE ACCUMULATIONS EXPECTED ACROSS THE
REGION...
...DANGEROUS TRAVEL CONDITIONS EXPECTED FRIDAY AND FRIDAY NIGHT...
The low pressure system that will bring us our weather through the
short term period is currently over southwestern Louisiana. This low
will track to the northeast across the southeastern CONUS and to the
Atlantic coast by Saturday morning.
Confidence in an impactful winter storm across central Kentucky is
high. Confidence in the impacts decreases along and north of the
Ohio River as there will be a very sharp cutoff to the precipitation
on the northern edge to the point that some counties in southern
Indiana have the potential to see ranges from nothing to 4 inches
across the county. Guidance is quite varied even along the Ohio
River and across the Louisville metro as far as QPF totals as well
as timing. Taking everything into consideration, have tried to take
into account a blend of guidance for this forecast.
As far as the sensible weather goes, precipitation will start to move
into southern KY late this evening. This will initially be a mix of
freezing rain and sleet. The latest guidance shows the warm layer
aloft will be the warmest right along the KY/TN border and peaks at
+3.5C. This decreases the further to the north you go. Therefore,
think that portions of south central Kentucky overnight may see more
sleet than freezing rain. The precipitation shield will continue to
spread northward during the overnight hours. Portions of north
central Kentucky and southern Indiana likely will not see any
precipitation until the daylight hours Friday. However, in these
regions the precipitation is expected to start as all snow.
The transition from a wintry mix to all snow should occur near
sunrise tomorrow as the warm nose aloft erodes. This transition will
occur the latest in the Lake Cumberland region, but even there it
should be all snow by mid morning. Snow will continue through the
day Friday with deformation bands setting up during the afternoon
hours. Snowfall rates will be much higher in any deformation bands
that set up. Accumulating snow will continue into Friday night, but
the axis will shift eastward and snow will become much lighter
overnight.
Highest ice totals through this event will be mainly along and south
of the Cumberland Parkway. However, they are expected to be
acoupleof tenths of an inch or less. Highest snowfall totals will be
in between the Parkways with the Bluegrass region expected to have
the highest. Will continue to mention 10-14+ inches in the highest
band and 18 or more is certainly not out of the question, though
where this would occur is nearly impossible to predict. Winds will
be a concern as well as they will gust to 30-35 mph at times. This
could cause near whiteout conditions. The worst conditions are
expected to be during the mid morning through the afternoon hours
across the region.
Will keep the Winter Storm Warning in place, but will adjust the
start times for some of the sections to account for precipitation
moving in later. Also will issue a Winter Weather Advisory in the
Winter Storm Watch area as snowfall amounts are expected to mainly
stay below 4 inches in this region.
.LONG TERM (Saturday through Thursday)...
Issued at 255 PM EST Thu Jan 21 2016
Deep closed upper low over the Carolinas on Saturday morning will
lift NE along the coast through the day, giving way to shortwave
ridging and a more progressive pattern for the rest of the weekend.
Lingering light snow showers on Saturday morning will wind down with
little or no accumulation. Temps could be tricky due to snowpack,
and will run solidly below seasonal normals. Sat night will be quite
cold, especially where the heaviest snow falls. Current min temp
forecast has single digits in line with our heaviest snow forecast.
The one main system is a progressive shortwave trof that scoots
through Monday/Monday night. This system does develop a decent tap
of Gulf moisture as it swings through. Return flow ahead of this
wave should warm temps into the 40s, so plenty warm enough for all
liquid, but will have to watch the temp recovery over the snow field
as it could cause precip type issues if the cold air does not scour
out. Official forecast is all rain, but this bears watching.
Once the surface feature moves through, upper trof hangs back from
the Great Lakes down through the Mississippi Valley, so we`ll stay a
bit unsettled with with below normal temps, plenty of cloud cover,
and small chances for a few light rain or snow showers.
&&
.AVIATION (06Z TAF Update)...
Updated at 1150 PM EST Thu Jan 21 2016
Impactful Winter Storm expected to begin overnight at BWG, then
spreading northward to SDF/LEX by Friday morning. Highest confidence
in worst conditions at LEX/BWG, SDF will be on the northern fringes
of the storm but should still see impacts. Will break down
timing/conditions below.
BWG...
Onset: Now
P-TYPE: -FZRA initially to Mix of -FZRA/IP/SN,
then all Snow after 7 AM CST.
Heaviest: 7 AM CST to end of TAF time
Conditions: low MVFR/IFR ceilings and visibility during lighter
snow, Minimums during heavy snow.
Winds: Steady NE overnight, increasing in magnitude to 10 to 15,
gust 25 mph Friday. Blowing/drifting snow possible.
SDF...
Onset: Around 7 AM EST
P-TYPE: All snow
Heaviest: 1 PM EST to 5 PM EST
Conditions: low MVFR/IFR ceilings and visibility during lighter
snow, low IFR/near minimums during heavier snow.
Winds: Steady NE overnight, increasing in magnitude to 10 to 15,
gusts 25-30 mph Friday. Blowing/Drifting snow possible.
LEX...
Onset: Around 8 AM EST
P-TYPE: All snow
Heaviest: Noon EST to end of TAF time
Conditions: low MVFR/IFR ceilings and visibility
during lighter snow, minimums in heavier snow.
Winds: Steady NE overnight, increasing in magnitude to 10 to 15,
gusts 25-35 mph Friday. Blowing/Drifting snow possible.
&&
.LMK Watches/Warnings/Advisories...
KY...Winter Storm Warning until 7 AM EST /6 AM CST/ Saturday for
KYZ024-026>029-034>043-045>049-053>057-061>067.
Winter Storm Warning until 6 AM CST Saturday for KYZ070>078-081-
082.
Winter Storm Warning from 7 AM EST /6 AM CST/ Friday to 7 AM EST
/6 AM CST/ Saturday for KYZ023-025-030>033.
IN...Winter Weather Advisory from 7 AM EST /6 AM CST/ Friday to 7 AM
EST /6 AM CST/ Saturday for INZ076>079-083.
Winter Storm Warning from 7 AM EST /6 AM CST/ Friday to 7 AM EST
/6 AM CST/ Saturday for INZ084-089>092.
&&
$$
Mesoscale......AMS
Short Term.....EER
Long Term......RAS
Aviation.......AMS
AREA FORECAST DISCUSSION
NWS JACKSON KY
1144 PM EST THU JAN 21 2016
.UPDATE...
ISSUED AT 1144 PM EST THU JAN 21 2016
BLENDED OBS INTO THE FORECAST GRIDS AGAIN...WITH ONLY MINOR
CHANGES. WILL LEAVE ANY SIGNIFICANT CHANGES BASED ON THE 00Z RUNS
TO THE NEWLY ARRIVED MID SHIFT. IT IS INTERESTING TO NOTE THE NAM
SHOWING CONVECTIVE SNOW FRIDAY EVENING OVER SE KY AND THE INTENSE
SNOWFALL RATES WHICH RESULT. THE GFS IS FURTHER SOUTH WITH THIS
FEATURE. CONFIDENCE IN A SMALL...ALBEIT SIGNIFICANT...FEATURE SUCH
AS THIS IS NOT HIGH...BUT ITS MODEL EXISTENCE POINTS TO THE
POTENTIAL.
UPDATE ISSUED AT 829 PM EST THU JAN 21 2016
MADE ONLY MINOR CHANGES TO THE PREVIOUS FORECAST BY BLENDING IN
OBS. THE MOST SUBSTANTIAL CHANGE WAS A FASTER INCREASE IN CLOUDS
THIS EVENING.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY EVENING)
ISSUED AT 456 PM EST THU JAN 21 2016
...DANGEROUS TRAVEL CONDITIONS EXPECTED FRIDAY AND SATURDAY...
A STRONG CLOSED UPPER LEVEL LOW WILL MOVE TOWARDS OUR AREA
OVERNIGHT TONIGHT AS IT DEEPENS RAPIDLY. THIS LOW WILL SHIFT
NORTHEAST AND ACROSS THE SOUTHERN TN VALLEY BY SATURDAY AFTERNOON.
THE ASSOCIATED SFC LOW WILL TAKE A SIMILAR TRACK ACROSS THE LOWER
TN VALLEY AND OFF THE EAST COAST SATURDAY AFTERNOON. BOTH THE NAM
AND GFS ARE IN GOOD AGREEMENT SO HAVE TRENDED TOWARD A BLEND OF
THESE MODELS IN THE SHORT TERM.
PRECIPITATION TYPE IS TRICKY REGARDING THIS SYSTEM AS MODEL
SOUNDINGS ARE TRENDING TOWARDS COLDER TEMPERATURES REMAINING
GENERALLY BELOW FREEZING THROUGH THE COLUMN. SOUNDINGS DO SHOW A
WEAK WARM NOSE AT THE ONSET OF THE EVENT MAINLY IN THE SOUTHERN
HALF OF THE FORECAST AREA. THIS IS WHERE THERE IS A CHANCE FOR A
MIXED BAG OF PRECIP INCLUDING...SLEET...FREEZING RAIN...RAIN AND
SNOW. HOWEVER...FURTHER NORTH...PRECIP SHOULD BE ALL SNOW...AND
ESPECIALLY GIVEN THE FACT THAT TEMPERATURES THIS AFTERNOON DIDN/T
WARM AS MUCH AS MODELS INDICATED...IS FURTHER PROOF THAT IT WILL
BE COLD ENOUGH TO SNOW. ALL PRECIP SHOULD CHANGE OVER TO SNOW
AROUND 1 PM TOMORROW WITH HEAVY SNOW POSSIBLE AT TIMES THROUGH
SATURDAY AFTERNOON. A WIDE SWATH OF TOTAL SNOW ACCUMULATIONS OF
12 TO 17 INCHES IS POSSIBLE ACROSS THE NORTHERN HALF OF THE
FORECAST AREA. SNOW ACCUMULATIONS IN THE SOUTHERN COUNTIES WILL
LIKELY BE LIMITED TO 4 TO 8 INCHES DUE TO THE MIXING OF
RAIN/FREEZING RAIN. THAT BEING SAID...THESE AMOUNTS COULD QUICKLY
CHANGE DEPENDING ON THE TEMPERATURES AND IF THE WARM NOSE COMES IN
MORE PRONOUNCED. SO STAY ABREAST TO THE WEATHER OVER THE NEXT 12
HOURS FOR ANY CHANGES THAT MAY OCCUR.
DRIVING CONDITIONS WILL BE TREACHEROUS SO PLEASE STAY OFF THE
ROADS IF POSSIBLE. IF NOT...MAKE SURE TO HAVE AN EMERGENCY KIT IN
YOUR CAR.
.LONG TERM...(FRIDAY EVENING THROUGH THURSDAY)
ISSUED AT 456 PM EST THU JAN 21 2016
PRECIPITATION WILL BE FALLING AS ALL SNOW BY FRIDAY EVENING NORTH OF
THE CORE OF THE SYSTEM...WITH SOME OF THIS CONTINUING TO BE OF THE
HEAVIER VARIETY. DURATION AND INTENSITY OF THIS WILL LARGELY DEPEND
ON WHETHER ANY DEFORMATION BANDING CAN MATERIALIZE AS STOUT EARLIER
DAY DEEP LAYER OMEGA PROFILES WANE. GIVEN HOW LOCKED IN THE RECENT
MODIFIED ARCTIC AIR MASS HAS BEEN...WOULD NOT BE SURPRISED FOR
UPPER LOW TO PASS EVEN FARTHER SOUTH THAN CURRENTLY PROGGED THUS
SHUNTING ANY SIGNIFICANT DRY SLOTTING POTENTIAL EAST OF THE
BLUEGRASS STATE. LIGHT SNOW WILL CONTINUE INTO SATURDAY MORNING
AND GRADUALLY SHIFT EAST AS LARGE SCALE SUBSIDENCE BUILDS INTO THE
REGION. NOT EXPECTING TEMPERATURES TO BREACH THE FREEZING MARK
SATURDAY GIVEN THE EXPECTED SNOWPACK IN PLACE. SURFACE RIDGE
BUILDING IN SATURDAY NIGHT ON TOP OF A FRESH SNOWPACK AND IN THE
PRESENCE OF LIGHT WINDS SHOULD PROMOTE COLD TEMPERATURES BOTTOMING
OUT MAINLY IN THE LOW-MID TEENS.
RISING HEIGHTS ALOFT FOR THE LATTER HALF OF THE WEEKEND INTO NEXT
WEEK WILL FINALLY SEND TEMPERATURES ABOVE FREEZING...BUT WILL STILL
LIKELY REMAIN BELOW AVERAGE THROUGH THE NEXT SEVEN DAYS. DAMPENING
UPPER TROUGH...EXTENDING FROM CANADA WELL INTO THE MISSISSIPPI
VALLEY...WILL THEN PUSH EAST EARLY NEXT WEEK...BRINGING
PRECIPITATION POTENTIAL BACK INTO THE PICTURE BY LATER IN THE DAY ON
MONDAY. WHILE PHASE WILL INITIALLY KICKOFF AS RAIN GIVEN THE
PRESENCE OF WARM AIR ADVECTION...WILL HAVE TO WATCH APPROACH OF A
CANADIAN AIR MASS INTO TUESDAY IN TERMS OF PRECIPITATION
TRANSITIONING TO THAT OF A WINTRY TYPE BEFORE COMING TO AN END.
FOLLOWING THIS INTO MID AND LATE WEEK...CONTINUED NORTHERN STREAM
ENERGY LOOKS TO TRANSLATE ACROSS THE REGION...THEREFORE KEEPING
TEMPERATURES BELOW NORMAL AND PRECIPITATION CHANCES IN THE OFFING.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 804 PM EST THU JAN 21 2016
IT IS THE CALM BEFORE THE STORM...WITH VFR AREA WIDE TO START THE
PERIOD. PRECIPITATION WILL SPREAD NORTH OVER THE REGION LATE
TONIGHT AND FRIDAY MORNING...ACCOMPANIED BY MAINLY IFR AND LIFR
CONDITIONS. POOR CONDITIONS SHOULD THEN PERSIST THROUGH THE
REMAINDER OF THE PERIOD. THE PRECIPITATION WILL INITIALLY BE A
MIXED BAG OF WINTER WEATHER IN THE SOUTHERN PART OF THE JKL
FORECAST AREA...BUT WILL TRANSITION TO MAINLY SNOW ON FRIDAY
AFTERNOON. IN THE NORTH...IT SHOULD BE MAINLY SNOW THROUGHOUT THE
EVENT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING FROM 7 AM FRIDAY TO 7 PM EST SATURDAY FOR
KYZ044-050>052-060-104-106-107-119.
WINTER STORM WARNING UNTIL 7 PM EST SATURDAY FOR KYZ058-059-068-
069-108>115-118-120.
WINTER STORM WARNING UNTIL 7 PM EST SATURDAY FOR KYZ079-080-
083>088-116-117.
&&
$$
UPDATE...HAL
SHORT TERM...JVM
LONG TERM...KAS
AVIATION...HAL
Area Forecast Discussion
National Weather Service Louisville KY
1113 PM EST THU JAN 21 2016
...Mesoscale Forecast Update...
Issued at 1110 PM EST Thu Jan 21 2016
Made some minor adjustments to the forecast for tonight. Slowed
down steady precip arrival according to radar trends and the latest
high-res data. Although very light spotty freezing rain has
developed over south central KY, it should be a few more hrs before
steady freezing rain mixed with sleet overspreads most of southern
KY. Logan County is the exception with steady freezing rain and a
light ice glaze already reported. This was only a very minor change
to POPs with POPs still ramping up quickly after 6z.
=========================================
Prelim 0Z Model Trends on the Winter Storm
=========================================
GFS/NAM 0Z runs are not significantly different to change the
forecast at this point. The 0Z 12km NAM shifted the heavy snow axis
a bit farther south. However, the 0Z 4km NAM is still pretty much
in line with the current forecast. The 0Z GFS backed off on QPF
amounts and snowfall totals overall.
We`re also starting to get into the range of the high-res models.
The HRRR has a pretty good handle on this system so far and is
showing a heavy snow axis from roughly Morgantown, KY to Madison, KY
so far (it`s not fully capturing the entire storm though at this
point). One thing to note in the sim. reflectivity of the 4km NAM
and HRRR is the moderate to heavy snow bands setting up tomorrow
morning. The HRRR has one closer to the Louisville Metro by mid
morning which seems a little faster than the 12km NAM. Will need to
watch the high-res models overnight to pin down any adjustments to
snowfall totals based on the high-res models.
Issued at 755 PM EST Thu Jan 21 2016
Weak isld-sct radar returns are now beginning to show up over south
central KY. Got a report of freezing rain in Adairville, KY (Logan
County). Expect precip to continue in these light patches for a few
hrs before freezing rain becomes more widespread over south central
KY by around midnight-1am. Current forecast looks on track with
the latest radar imagery and obs.
.SHORT TERM (Now through Friday Night)...
Issued at 332 PM EST Thu Jan 21 2016
...WINTER STORM TO AFFECT THE AREA LATE TONIGHT THROUGH SATURDAY...
...SIGNIFICANT SNOW AND SOME ICE ACCUMULATIONS EXPECTED ACROSS THE
REGION...
...DANGEROUS TRAVEL CONDITIONS EXPECTED FRIDAY AND FRIDAY NIGHT...
The low pressure system that will bring us our weather through the
short term period is currently over southwestern Louisiana. This low
will track to the northeast across the southeastern CONUS and to the
Atlantic coast by Saturday morning.
Confidence in an impactful winter storm across central Kentucky is
high. Confidence in the impacts decreases along and north of the
Ohio River as there will be a very sharp cutoff to the precipitation
on the northern edge to the point that some counties in southern
Indiana have the potential to see ranges from nothing to 4 inches
across the county. Guidance is quite varied even along the Ohio
River and across the Louisville metro as far as QPF totals as well
as timing. Taking everything into consideration, have tried to take
into account a blend of guidance for this forecast.
As far as the sensible weather goes, precipitation will start to move
into southern KY late this evening. This will initially be a mix of
freezing rain and sleet. The latest guidance shows the warm layer
aloft will be the warmest right along the KY/TN border and peaks at
+3.5C. This decreases the further to the north you go. Therefore,
think that portions of south central Kentucky overnight may see more
sleet than freezing rain. The precipitation shield will continue to
spread northward during the overnight hours. Portions of north
central Kentucky and southern Indiana likely will not see any
precipitation until the daylight hours Friday. However, in these
regions the precipitation is expected to start as all snow.
The transition from a wintry mix to all snow should occur near
sunrise tomorrow as the warm nose aloft erodes. This transition will
occur the latest in the Lake Cumberland region, but even there it
should be all snow by mid morning. Snow will continue through the
day Friday with deformation bands setting up during the afternoon
hours. Snowfall rates will be much higher in any deformation bands
that set up. Accumulating snow will continue into Friday night, but
the axis will shift eastward and snow will become much lighter
overnight.
Highest ice totals through this event will be mainly along and south
of the Cumberland Parkway. However, they are expected to be
acoupleof tenths of an inch or less. Highest snowfall totals will be
in between the Parkways with the Bluegrass region expected to have
the highest. Will continue to mention 10-14+ inches in the highest
band and 18 or more is certainly not out of the question, though
where this would occur is nearly impossible to predict. Winds will
be a concern as well as they will gust to 30-35 mph at times. This
could cause near whiteout conditions. The worst conditions are
expected to be during the mid morning through the afternoon hours
across the region.
Will keep the Winter Storm Warning in place, but will adjust the
start times for some of the sections to account for precipitation
moving in later. Also will issue a Winter Weather Advisory in the
Winter Storm Watch area as snowfall amounts are expected to mainly
stay below 4 inches in this region.
.LONG TERM (Saturday through Thursday)...
Issued at 255 PM EST Thu Jan 21 2016
Deep closed upper low over the Carolinas on Saturday morning will
lift NE along the coast through the day, giving way to shortwave
ridging and a more progressive pattern for the rest of the weekend.
Lingering light snow showers on Saturday morning will wind down with
little or no accumulation. Temps could be tricky due to snowpack,
and will run solidly below seasonal normals. Sat night will be quite
cold, especially where the heaviest snow falls. Current min temp
forecast has single digits in line with our heaviest snow forecast.
The one main system is a progressive shortwave trof that scoots
through Monday/Monday night. This system does develop a decent tap
of Gulf moisture as it swings through. Return flow ahead of this
wave should warm temps into the 40s, so plenty warm enough for all
liquid, but will have to watch the temp recovery over the snow field
as it could cause precip type issues if the cold air does not scour
out. Official forecast is all rain, but this bears watching.
Once the surface feature moves through, upper trof hangs back from
the Great Lakes down through the Mississippi Valley, so we`ll stay a
bit unsettled with with below normal temps, plenty of cloud cover,
and small chances for a few light rain or snow showers.
&&
.AVIATION (00Z TAF Update)...
Updated at 600 PM EST Thu Jan 21 2016
Impactful Winter Storm expected to begin overnight at BWG, then
spreading northward to SDF/LEX by Friday morning. Highest confidence
in worst conditions at LEX/BWG, SDF will be on the northern fringes
of the storm but should still see impacts. Will break down
timing/conditions below.
BWG...
Onset: Around 1 AM CST
P-TYPE: Initial Mix of -FZRA/IP/SN, then all Snow after 3 AM CST.
Heaviest: 7 AM CST to end of TAF time
Conditions: low MVFR/IFR ceilings and visibility during lighter
snow, Minimums during heavy snow.
Winds: Steady NE overnight, increasing in magnitude to 10 to 15,
gust 25 mph Friday. Blowing/drifting snow possible.
SDF...
Onset: Around 9 AM EST
P-TYPE: All snow
Heaviest: 1 PM EST to 7 PM EST
Conditions: low MVFR/IFR ceilings and visibility during lighter
snow, low IFR/near minimums during heavier snow.
Winds: Steady NE overnight, increasing in magnitude to 10 to 15,
gusts 25-30 mph Friday. Blowing/Drifting snow possible.
LEX...
Onset: Around 7 AM EST
P-TYPE: All snow
Heaviest: Noon EST to end of TAF time
Conditions: low MVFR/IFR ceilings and visibility during lighter
snow, minimums in heavier snow.
Winds: Steady NE overnight, increasing in magnitude to 10 to 15,
gusts 25-35 mph Friday. Blowing/Drifting snow possible.
&&
.LMK Watches/Warnings/Advisories...
KY...Winter Storm Warning until 7 AM EST /6 AM CST/ Saturday for
KYZ024-026>029-034>043-045>049-053>057-061>067.
Winter Storm Warning until 6 AM CST Saturday for KYZ070>078-081-
082.
Winter Storm Warning from 7 AM EST /6 AM CST/ Friday to 7 AM EST
/6 AM CST/ Saturday for KYZ023-025-030>033.
IN...Winter Weather Advisory from 7 AM EST /6 AM CST/ Friday to 7 AM
EST /6 AM CST/ Saturday for INZ076>079-083.
Winter Storm Warning from 7 AM EST /6 AM CST/ Friday to 7 AM EST
/6 AM CST/ Saturday for INZ084-089>092.
&&
$$
Mesoscale......AMS
Short Term.....EER
Long Term......RAS
Aviation.......BJS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1158 PM EST THU JAN 21 2016
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 329 PM EST THU JAN 21 2016
SOME LIGHT LAKE EFFECT SNOW SHOWERS WILL CONTINUE INTO THE EVENING
HOURS BEFORE WINDING DOWN OVERNIGHT. ACCUMULATIONS WILL BE
LIGHT...ON THE ORDER OF A DUSTING. QUIET WEATHER IS FORECAST THROUGH
THE WEEKEND AS A WINTER STORM SYSTEM PIVOTS OFF THE EAST COAST OF
THE UNITED STATES. WE WILL SEE DRY WEATHER FRIDAY...SATURDAY AND
SUNDAY. CLOUD COVER WILL DECREASE A BIT EACH DAY. HIGH TEMPERATURES
THROUGH THE WEEKEND WILL BE NEAR NORMAL AROUND 30 DEGREES.
&&
.UPDATE...
ISSUED AT 1020 PM EST THU JAN 21 2016
I UPDATED THE FORECAST GRIDS TO SHOW THE WEST TO EAST SNOW BAND
THAT HAS BEEN HERE ALL EVENING. IT SHOULD DISSIPATE BY 5 AM AS
WINDS TURN NORTHEAST FROM 850 MB TO THE GROUND.
LIGHT SNOW CONTINUED TO FALL IN AN EAST TO WEST BAND GENERALLY
ALONG I-96 (MORE OR LESS). CURIOUSLY THIS BAND IS WHERE THE
SURFACE DEW POINTS ARE THE HIGHEST (WHICH WOULD MAKE SENSE SINCE
IT IS SNOWING IN THIS AREA). THERE SEEMS TO BE SOME SORT OF
CONVERGENCE FEATURE IN THIS AREA AROUND 925 MB. IN ANY EVENT...AS
THE SYSTEM TO OUR SOUTH GETS CLOSER...WINDS TURN NORTHEAST ACROSS
LOWER MICHIGAN BY 5 AM (IN THE 925 TO 850 MB LAYER)...SO THAT
WILL END THIS FEATURE. THE RAP MODEL SHOWS IT SLOWLY LIFTING NORTH
SO THAT IS WHAT I DID WITH IT IN THE GRIDS.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 329 PM EST THU JAN 21 2016
ONGOING LAKE EFFECT IS SOMEWHAT SPOTTY IN NATURE WITH THE BANDS
LOOKING MORE LIKE PLUMES AS OF 300 PM. JUST ENOUGH INSTABILITY AND
MOISTURE ARE PRESENT TO PROVIDE SOME SHALLOW LAKE EFFECT SNOW
SHOWERS. REFLECTIVITY HAS COME DOWN JUST A BIT WITHIN THE LAST HOUR.
NOT EXPECTING MUCH IN THE WAY OF ACCUMULATION THIS EVENING OR
TONIGHT GIVEN THE WEAKENING FLOW. NOT OUT OF THE QUESTION TO SEE AN
ADDITIONAL FEW TENTHS OF AN INCH OF SNOW IN SPOTS WHERE THE WEAK
BANDS REMAIN THOUGH THROUGH MID EVENING.
OVERNIGHT THE FLOW SHIFTS TO THE NORTH IN RESPONSE TO THE DEEPENING
LOW IN THE SOUTH. THIS SHOULD TAKE ANY REMAINING LAKE EFFECT TOWARD
THE LAKE MICHIGAN SHORE. ON FRIDAY...THE FLOW GOES NORTHEAST WHICH
SHOULD TAKE ANY WEAK BANDING OFF SHORE. HAVE SOME SMALL CHANCE POPS
IN FOR TONIGHT IN THE WEST AND THEN WENT WITH A DRY FORECAST ON
FRIDAY.
A NORTHEAST FLOW REMAINS IN PLACE ON FRIDAY NIGHT...FOLLOWED BY A
RIDGE SHIFTING THROUGH ON SATURDAY. SATURDAY NIGHT THE FLOW GOES
SOUTHWEST. ESSENTIALLY...QUIET WEATHER WILL CONTINUE IN THESE THREE
FORECAST PERIODS. FRIDAY NIGHT CLOUDS WILL STREAM INTO THE CWA OFF
OF LAKE HURON. CANNOT RULE OUT SOME FLURRIES BUT KEPT THE FORECAST
DRY FOR NOW. SATURDAY...SOME SUNSHINE SHOULD DEVELOP AS INSTABILITY
WANES IN A WARM AIR ADVECTION REGIME. ANY PRECIPITATION ASSOCIATED
WITH A LOW MOVING THROUGH THE NORTHERN GREAT LAKES SATURDAY NIGHT
SHOULD REMAIN WELL NORTH OF OUR AREA.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 329 PM EST THU JAN 21 2016
THE REGION IS LOOKING AT A SOMEWHAT UNSETTLED WEATHER PATTERN IN THE
LONG TERM WHILE TEMPERATURES WILL BE GENERALLY IN A RANGE OF
SEASONABLE VALUES.
THE LONG TERM WILL START OUT ON THE QUIET SIDE FOR THE STATE WITH
MAINLY DRY WEATHER EXPECTED INTO SUN NIGHT. WE WILL SEE AN UPPER
RIDGE BUILDING OVER THE REGION AT THAT TIME...IN THE WAKE OF THE BIG
EAST COAST STORM AND THE NEXT UPPER TROUGH THAT WILL BE APPROACHING
THE AREA. THERE IS A SHORT WAVE RIDING OVER THE RIDGE THAT LOOKS TO
STAY FAR ENOUGH NORTH TO AFFECT THE AREA.
WE ARE LOOKING AT SOME RAIN AND SNOW MOVING INTO THE AREA LATE ON
MON...AND ESPECIALLY MON NIGHT. WE WILL SEE AN UPPER TROUGH THAT
MOVES ONSHORE OVER THE WEST COAST EARLY THIS COMING WEEKEND. THIS
WILL TRAVERSE THE COUNTRY AND COME INTO THE AREA LATE MON. THIS
TROUGH WILL DRAW SOME MILDER AND MORE MOIST AIR FROM THE GULF NORTH
INTO THE AREA. IT LOOKS LIKE THERE IS A GOOD CHC THAT PCPN WILL
START OUT AS RAIN AND CHANGE OVER TO SNOW LATE MON NIGHT INTO EARLY
TUE MORNING. SOME LIGHT ACCUMULATIONS OF SNOW REMAIN POSSIBLE.
WE WILL THEN SEE LAKE EFFECT SNOW SHOWERS TAKE SHAPE FOR THE TUE
INTO WED TIME FRAME. THE UPPER JET WILL BE NEARBY...BUT WE ARE NOT
LOOKING AT AS COLD OF TEMPERATURES AS THE PAST FEW DAYS. THERE IS
SOME POTENTIAL FOR SOME ENHANCED AMOUNTS AS MOISTURE LOOKS RATHER
PLENTIFUL...INVERSION HEIGHTS ARE UP A LITTLE...AND THE MODELS ARE
KEYING IN ON SOME CONVERGENCE BANDS. DETAILS ARE A BIT UNCLEAR YET
BEING A FEW DAYS OUT YET. ANOTHER BURST OF SNOW WILL BE POSSIBLE ON
THU AS A MORE DEFINED SHORT WAVE MOVES THROUGH.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1158 PM EST THU JAN 21 2016
CEILINGS ARE EXPECTED TO REMAIN AROUND 2500 FEET OVERNIGHT AND
INTO FRIDAY. CEILINGS SHOULD COME UP ABOVE 3500 FEET LATE FRIDAY
AFTERNOON. WINDS WILL BE LIGHT AND VARIABLE OVERNIGHT AND
NORTHEAST AOB 10 KNOTS ON FRIDAY.
&&
.MARINE...
ISSUED AT 329 PM EST THU JAN 21 2016
A FAIRLY LIGHT WIND REGIME WILL BE IN PLACE ACROSS THE SOUTHERN HALF
OF LAKE MICHIGAN THROUGH SATURDAY. A RIDGE OF HIGH PRESSURE WILL BE
SITUATED ACROSS THE GREAT LAKES REGION WHICH WILL KEEP WINDS AND
WAVES BELOW SMALL CRAFT ADVISORY CRITERIA THROUGH SATURDAY.
SOUTHWEST WINDS WILL INCREASE SATURDAY NIGHT INTO SUNDAY WHICH MAY
LEAD TO THE NEED OF AN SCA. SOUTHWEST WINDS LOOK TO REACH THE 15 TO
25 KNOT RANGE. WAVES WILL LIKELY PUSH INTO THE 3 TO 5 FOOT RANGE AS
WE HEAD INTO SUNDAY...ESPECIALLY FROM HOLLAND NORTHWARD.
&&
.HYDROLOGY...
ISSUED AT 329 PM EST THU JAN 21 2016
ICE JAMS HAVE FORMED IN SPOTS ALONG SEVERAL RIVERS. A GENERAL RISE
IN RIVER LEVELS WITH OCCASIONAL DOWNWARD FLUCTUATIONS HAS BEEN
OCCURRING IN SPOTS SUCH AS IONIA... EAGLE... SMYRNA... AND
SCOTTVILLE. IONIA HAS SURPASSED BANKFULL AND THE OTHER THREE ARE
CURRENTLY EXPECTED TO REMAIN JUST BELOW BANKFULL BUT WILL BE
MONITORED.
WITH BELOW-FREEZING WEATHER CONTINUING THROUGH THE REMAINDER OF THE
WEEK... LITTLE CHANGE IN THE ICE JAMS IS EXPECTED... AND RIVER
LEVELS SHOULD REMAIN ELEVATED UPSTREAM OF THE JAMS. SIGNIFICANT
FLOODING IS NOT AN IMMEDIATE CONCERN. NEVERTHELESS... ICE JAMS CAN
CAUSE RELATIVELY RAPID CHANGES IN RIVER LEVELS UPSTREAM AND
DOWNSTREAM OF THE JAM WITH LITTLE ADVANCE NOTICE.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...DUKE
SHORT TERM...DUKE
LONG TERM...NJJ
AVIATION...OSTUNO
HYDROLOGY...CAS
MARINE...DUKE
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1114 PM CST THU JAN 21 2016
.UPDATE:
Issued at 902 PM CST Thu Jan 21 2016
The radar continued to depict very low reflectivities over
central MO this evening ahead of an upper level low over western
MO. So far no precipitation was being reported at the ground, but
could not rule out a brief period of flurries from the mid level
cloudiness this evening. Surface low over southern MS will move
northeastward into northern AL by 12Z Friday. Models do bring
precipitation shield north-northeastward overnight, but it
appears that the precipitation will remain south-southeast of our
forecast area. Could not rule out very light snow or flurries late
tonight across the extreme southern/southeastern portion of our
forecast area with no accumulation expected. With cloud cover lows
tonight should be at least a little warmer than the previous night
over most of the region.
GKS
&&
.SHORT TERM: (Through Friday)
Issued at 240 PM CST Thu Jan 21 2016
Deep trof with two very distinct vortices is continuing to dig
across the eastern Plains. The northern vortex is over eastern
Kansas producing some light snow...while the southern vortex is
moving along the Oklahoma Texas border. Our CWFA is on the
fringes of influence of both of these vortices, and dry low level
air is being pulled from the east-northeast across the area as the
surface reflection of the trof deepens over Louisiana. This dry
low level flow more or less evaporated much of our precip this
morning, and it will continue to keep us dry tonight into Friday.
Most short range guidance is in agreement that accumulating precip
will stay south and east of the area through Friday...with the
notable exception of the HRRR which does show some light snow
overnight across our southern counties. Kept some low chance PoPs
in southern zones to cover this eventuality. Temperatures in the
column should be cold enough for snow...if anything should fall.
Should see temperatures continue to moderate with lows tonight
generally in the upper teens and highs Friday in the low 30s. We
might even break through the freezing mark across our southern
zones.
Carney
.LONG TERM: (Saturday through Next Thursday)
Issued at 240 PM CST Thu Jan 21 2016
(Saturday and Sunday)
Focus will be temps with sfc ridge building into the region thru the
weekend.
With the sfc ridge building into the area Fri night, expect clouds
to gradually clear with system pulling newd out of the region. Winds
will gradually diminish, but perhaps more slowly. These two
features will have a large impact on temps overnight and will likely
end up with a large temp spread across the CWA. Given how quickly
temps can drop as winds become light and with potentially some snow
left, have trended twd the cooler guidance.
With upper level ridging and strong swly low level winds building
the thermal ridge into the region thru the later half of the
weekend, have trended twd the warmer guidance. Going forecast for
Sun may still be too cool. However, one concern is that sfc winds
may be more sely than sly or swly.
(Monday through Thursday)
Focus turns to system approaching the CWA on Mon. Mdls have come
into very good agreement regarding mass fields for this system. Some
timing differences still exist, but are in remarkably good agreement
for day 5. With the better agreement, have begun to fine tune the p-
types for this system. Given thermal profiles, believe this will be
mainly a light RA event. Cold air will move in behind the system Mon
afternoon into Mon night. There is a fair amount of uncertainty in
how quickly this will occur. Have therefore kept mention of RA thru
Mon, but trended twd a RA to mix to SN for Mon night.
With low level wly flow late in the period, have moderated temps for
now. Some timing differences on the next s/w to approach the region
into Thurs. Little if any precip is anticipated, but timing of this
trof may impact temps.
Tilly
&&
.AVIATION: (For the 06z TAFs through 06z Friday Night)
Issued at 1108 PM CST Thu Jan 21 2016
VFR flight conditions are expected overnight into early Friday
morning with extensive mid-high clouds. A deepening storm system
to our south will also produce increasing northerly surface winds.
Will need to keep an eye on potential for LLWS overnight (09-14z)
as the low level winds in the lowest 2 km increase, but present
indications are they will remain just above thresholds. Stratus
currently located across the Upper MS Valley and Great Lakes will
advect southward into the region from mid-morning into the early
afternoon bringing MVFR flight conditions.
Specifics for KSTL:
VFR flight conditions are expected overnight into early Friday
afternoon with extensive mid-high clouds. A deepening storm
system to our south will also produce increasing northerly surface
winds. Will need to keep an eye on potential for LLWS overnight
(09-14z) as the low level winds in the lowest 2 km increase, but
present indications are they will remain just above thresholds.
Stratus currently located across the Upper MS Valley and Great
Lakes will advect southward into the terminal in the early
afternoon bringing MVFR flight conditions.
Glass
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1157 PM CST THU JAN 21 2016
.SHORT TERM...(THIS EVENING THROUGH FRIDAY DAYTIME)
ISSUED AT 410 PM CST THU JAN 21 2016
BIGGEST FORECAST ISSUES INCLUDE THE POTENTIAL FOR FREEZING DRIZZLE
THIS AFTERNOON/EVENING AND FOG THIS AFTERNOON THROUGH FRIDAY MORNING.
THE NAM...WRF...AND TO SOME EXTENT THE HRRR INDICATE THE POSSIBILITY
OF SOME LIGHT PRECIPITATION...AND MODEL SOUNDINGS IN BUFKIT INDICATE
THAT WE COULD BE IN FOR SOME FREEZING DRIZZLE OR FLURRIES...POSSIBLY
LINGERING INTO THE EVENING FOR LOCATIONS ALONG AND EAST OF HIGHWAY
281.
FOG IS STUBBORNLY PERSISTENT FOR AT LEAST A FEW
LOCATIONS...ESPECIALLY HASTINGS AND GRAND ISLAND WHERE IS HAS
BEEN UNDER A MILE FOR AWHILE. CLOUD BASES HAVE BEEN STEADILY
LOWERING TODAY AND COULD HAVE A ROLE IN KEEPING THE FOG
AROUND...DESPITE THE WIND STARTING TO BACK MORE TO THE NORTH AND
INCREASE A BIT. A FEW SHORT TERM MODELS ARE AT LEAST HINTING ON
THE FACT THAT IT MAY BE DIFFICULT TO COMPLETELY SHAKE THE FOG. I
INTRODUCED MORE FOG IN OUR NORTHWEST LATE TONIGHT INTO FRIDAY
MORNING AS WIND BEGINS TO DECREASE WITH THE SURFACE RIDGE
APPROACHING.
KNOCKED TEMPERATURES DOWN A BIT FOR HIGHS FRIDAY IN THE MID TO UPPER
20S FOR MOST AREAS.
.LONG TERM...(FRIDAY EVENING THROUGH THURSDAY)
ISSUED AT 410 PM CST THU JAN 21 2016
ALTHOUGH CONFIDENCE REMAINS RATHER HIGH THAT THE VAST MAJORITY OF
THIS 6-DAY PERIOD CONTINUES TO LOOK PRECIPITATION-FREE...AND THAT
THAT TEMPERATURES SHOULD GENERALLY AVERAGE "NEAR-NORMAL" (MEANING
WITHIN 5 DEGREES ABOVE OR BELOW AVERAGE) IN MOST PLACES ON MOST
DAYS...THIS "FEELS" LIKE A FORECAST THAT COULD END UP BEING BE A
BIT MORE COMPLICATED/COMPLEX THAN EARLIER THOUGHT ESPECIALLY WITH
REGARD TO SKY COVER/TEMPS (FOG POTENTIAL?) OVER THE WEEKEND...AND
THEN THE NEXT POTENTIAL QUICK-HITTING "SNOW-MAKER" THAT SWEEPS
ACROSS SUNDAY NIGHT-MONDAY.
STICKING WITH THE BIG PICTURE BUT CONCENTRATING SOLELY ON
PRECIPITATION/SNOW CHANCES...THE ONLY MENTION OF ANYTHING DURING
THESE 6 DAYS IS SUNDAY EVENING-MONDAY (AT LEAST FOR NOW...LOW
PRECIP CHANCES HAVE BEEN REMOVED FROM THE WESTERN/NORTHERN CWA FOR
SUNDAY DAYTIME). THIS STILL LOOKS LIKE A FAIRLY "MINOR" SYSTEM FOR
SNOW ACCUMULATION POTENTIAL...BUT AS JUST EVIDENCED BY WHAT
HAPPENED OVER MUCH OF OUR SOUTHERN CWA OVER THE PAST 24
HOURS...WHAT APPEAR TO BE "MINOR" SYSTEMS 3-4 DAYS OUT CAN
CERTAINLY TURN INTO SOMETHING MORE WITH TIME...SO THIS NEEDS
MONITORED CLOSELY. AT ANY RATE...THIS SYSTEM REMAINS JUST BEYOND
THE 72-HOUR-OR-CLOSER WINDOW FOR WHICH WE FORECAST OFFICIAL SNOW
ACCUMULATION FOR...AND THUS IT`S STILL TOO SOON TO GET TOO CAUGHT
UP IN THE DETAILS.
TURNING TO TEMPERATURES IN THE BIG PICTURE...WHAT ONCE LOOKED
LIKE A SOMEWHAT MILD WEEKEND HAS SEEN THE PICTURE "MUDDIED" A BIT
BY TWO MAIN FACTORS: 1) WITH THE LATEST ROUND OF SNOW...THE VAST
MAJORITY OF THE CWA NOW HAS AT LEAST 1-2 INCHES OF SNOW ON THE
GROUND...WHICH WILL OBVIOUSLY ACT TO SUPPRESS HEATING POTENTIAL
AND 2) SOME MODELS (ESPECIALLY THE NAM) ARE INSISTING THAT MUCH OF
THE WEEKEND COULD FEATURE STUBBORN/PESKY LOW STRATUS THAT MAY BE
TOUGH TO FULLY SCOUR OUT. HOWEVER...OTHER MODELS (SUCH AS THE GFS)
ARE MORE OPTIMISTIC WITH GENERALLY NO WORSE THAN PARTLY CLOUDY
SKIES...AND THUS BETTER POTENTIAL FOR A MODEST WARM-UP. AS
EVIDENCE OF THIS GROWING UNCERTAINTY FOR WEEKEND
TEMPERATURES...THERE IS A NOTABLE 10-15 DEGREE SPREAD IN
SATURDAY`S HIGH TEMPERATURE FORECAST BETWEEN THE 12Z MET GUIDANCE
(COLDER) AND MAV GUIDANCE (MILDER)...WHICH IS NEVER A GREAT
CONFIDENCE-BOOSTER FOR ONLY BEING 2 DAYS OUT.
WITH THE MAIN BIG PICTURE CONCERNS COVERED...WILL NOW DIVE INTO A
LITTLE MORE DAY-TO-DAY DETAIL IN 12-36 HOUR BLOCKS:
FRIDAY EVENING/NIGHT: CONFIDENCE IS HIGH IN A PRECIPITATION-FREE
NIGHT...AS A MID-UPPER LEVEL RIDGE AXIS OVERSPREADS THE CENTRAL
PLAINS FROM THE WEST. CONFIDENCE IS ALSO HIGH IN WINDS...WHICH
WILL REMAIN FAIRLY LIGHT THROUGH THE NIGHT IN THE EASTERN CWA
CLOSEST TO THE DEPARTING SURFACE RIDGE AXIS...BUT WILL FEATURE
STEADIER 5-15 MPH SOUTHERLY BREEZES ACROSS MOST CENTRAL/WESTERN
COUNTIES (ESPECIALLY AFTER MIDNIGHT) IN THE SOUTHERLY RETURN FLOW
AROUND THE DEPARTING HIGH. UNFORTUNATELY...CONFIDENCE IN CLOUD
COVER AND RESULTANT LOW TEMPERATURES IS A BIT SHAKY...ESPECIALLY
WITH THE NAM MORE INSISTENT ON LINGERING LOW STRATUS OVER THE
AREA. NUDGED UP LOWS SLIGHTLY FROM PREVIOUS...ALTHOUGH THE DEEPER
SNOW- COVERED AREAS OF THE SOUTHERN CWA HAVE THE POTENTIAL TO DROP
BELOW EXPECTATIONS IF SKIES CLEAR. FOR NOW WILL RUN WITH A RANGE
FROM 10-15 DEGREES EAST...TO 15-18 WEST. WOULD NOT BE SURPRISED TO
SEE AT LEAST SOME LIGHT FOG DURING THE NIGHT...BUT OMITTED FROM
THE FORECAST AS SOUTHERLY BREEZES SHOULD KEEP VISIBILITIES FROM
GETTING TOO OUT OF HAND.
SATURDAY DAYTIME-NIGHT: MUCH THE SAME STORY AS FRIDAY NIGHT:
CONFIDENCE REMAINS HIGH IN A DRY FORECAST THROUGH THESE 24 HOURS
AS LINGERING RIDGING ALOFT REMAINS THE DOMINANT LARGE-SCALE
FACTOR...BUT CONFIDENCE IN CLOUD COVER AND ESPECIALLY DAYTIME HIGH
TEMPS IS SOMEWHAT SHAKY. GENERALLY NUDGED DOWN HIGH TEMPS SLIGHTLY
IN THE WESTERN CWA WHILE LEAVING EASTERN AREAS SIMILAR TO
PREVIOUS...THUS RESULTING IN A MODEST GRADIENT FROM MID-30S EAST
TO MID-40S WEST. THE DAY COULD BE SLIGHTLY BREEZY WITH SUSTAINED
SPEEDS UP TO AROUND 15 MPH IN SOME AREAS. AS WINDS SLACKEN
SATURDAY NIGHT...FOG COULD BECOME AN ISSUE...BUT IT`S STILL A BIT
TOO EARLY TO START ADVERTISING FOG THIS FAR OUT.
SUNDAY DAYTIME: THIS IS A DRY FORECAST PERIOD FOR NOW...BUT THIS
IS ASSUMING THAT LIGHT DRIZZLE DOES NOT MATERIALIZE FROM ANY
POSSIBLE LOWER CLOUDS. HIGH TEMPS AGAIN MAINLY MID-30S TO LOW-40S.
SUNDAY NIGHT-MONDAY DAYTIME: AS ALREADY COVERED...THESE 24 HOURS
CONTAIN THE ONLY TRUE PRECIP CHANCES OF THIS ENTIRE LONG TERM
PERIOD...BUT GIVEN IT`S STILL 3+ DAYS AWAY PRECIP CHANCES (POPS)
ARE ONLY AS HIGH AS THE 30-50 PERCENT RANGE. EVEN IF SNOW DOES NOT
ULTIMATELY AMOUNT TO MUCH...WILL HAVE TO WATCH FOR LIGHT FREEZING
DRIZZLE POTENTIAL AS IT GETS CLOSER.
MONDAY NIGHT: AT LEAST FOR NOW...LOOKS PRECIP-FREE BEHIND THE
DEPARTING SYSTEM.
TUESDAY DAYTIME-NIGHT: LOOKS DRY AT THIS TIME...AS MID-LEVEL
HEIGHTS RISE A BIT BEHIND THE DEPARTING SYSTEM. LOW LEVEL WESTERLY
FLOW COULD TRY TO WARM THINGS A BIT...BUT LINGERING SNOW COVER IS
LIKELY A MITIGATING FACTOR.
WEDNESDAY DAYTIME-THURSDAY DAYTIME: THESE LAST FEW FORECAST
PERIODS ARE CURRENTLY DRY...BUT THE LATEST ECMWF SUGGESTS THAT A
QUICK SHOT OF LIGHT PRECIP CANNOT BE RULED OUT FOR WEDNESDAY.
OVERALL THOUGH...THE GENERAL SIGNAL FOR THESE FEW DAYS IS A MODEST
WARM UP AS MILDER AIR TRIES PUSHING IN FROM THE WEST ON LOW-LEVEL
WESTERLIES. MUCH OF THE CWA IS CURRENTLY EXPECTED TO SEE UPPER 30S
TO MID 40S ON THESE DAYS...WITH MAYBE A FEW 50S TRYING TO FLIRT
WITH SOUTHERN/SOUTHWEST ZONES.
&&
.AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1147 PM CST THU JAN 21 2016
MVFR OR LOWER CIGS WILL PREVAIL AT BOTH TERMINALS FOR THE MAJORITY
OF THE NEXT 12-18 HOURS AS A LARGE AREA OF STRATUS EXTENDS FROM
THE NORTH PLAINS ACROSS THE LOCAL AREA. EXPECT LIGHT NORTHERLY
FLOW TO EVENTUALLY SHIFT AND BECOME MORE SOUTHERLY LATE IN THE
PERIOD AND FOR CIGS TO SCATTER AS THIS OCCURS...WITH VFR
CONDITIONS RETURNING DURING THE LATE AFTERNOON HOURS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...HEINLEIN
LONG TERM...PFANNKUCH
AVIATION...ROSSI
AREA FORECAST DISCUSSION
NWS RALEIGH NC
444 AM EST FRI JAN 22 2016
.SYNOPSIS...
A POWERFUL STORM SYSTEM WILL TRACK NORTHEASTWARD OVER
THE CAROLINAS TODAY THROUGH TONIGHT... THEN PUSH SLOWLY OFF THE
MIDATLANTIC COAST SATURDAY THROUGH SATURDAY NIGHT. HIGH PRESSURE
WILL BUILD OVER THE AREA SUNDAY... THEN MOVE EAST AND OFFSHORE
MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 415 AM THURSDAY...
...WINTER STORM CONDITIONS WILL OVERSPREAD CENTRAL NC THIS
MORNING...
...LATEST GUIDANCE SUGGESTS AN EARLIER CUT OFF TO SIGNIFICANT
PRECIPITATION RATES THIS AFTN/EARLY EVE AND WE HAVE DECREASED
SNOW AND ICE ACCUMULATIONS BY ABOUT 20 PERCENT...
...GUIDANCE IS ALSO WARMER IN THE MID LEVELS SUGGESTING LOWER
SNOW ACCUMULATIONS AND MORE SLEET AND FREEZING RAIN...
LATEST SURFACE ANALYSIS SHOWS THE WINTER STORM DEEPENING ACROSS
ALABAMA THIS MORNING WITH PRECIPITATION SPREADING NORTHEAST ACROSS
THE CAROLINAS AND INTO THE WESTERN PARTS OF THE RAH CWA. LIGHT
SNOW BEGAN AT 4AM IN GREENSBORO AND LEXINGTON AND LIGHT
FREEZING RAIN AND RAIN AT ASHEBORO...ROCKINGHAM AND WADESBORO.
RECENT GUIDANCE AND SURFACE OBSERVATIONS SUGGEST THAT SOME
DOWNWARD ADJUSTMENT TO THE ACCUMULATION TOTALS ARE LIKELY NEEDED.
HIGHER RESOLUTION GUIDANCE INCLUDING THE HI RES WINDOW ARW AND NMM
AND THE HRRR NOTE THE BACK EDGE OF THE SIGNIFICANT PRECIPITATION
LIKELY TO PROGRESS THROUGH CENTRAL NC MUCH MORE QUICKLY AND AHEAD
OF THE DRY SLOT. IN ADDITION...SURFACE OBSERVATIONS NOTE A
SIGNIFICANT PRESSURE FALL NORTH AND NORTHEAST OF THE SURFACE LOW
IN ALABAMA. THE HRRR PICKS UP ON THIS AND HIGHLIGHTS A SFC
PRESSURE FIELD INDICATIVE OF A POSSIBLE GRAVITY WAVE WITH
PRECIPITATION DECREASING BEHIND THIS FEATURE. HAVE ACCORDINGLY
LOWERED SNOW AND SLEET ACCUMULATIONS AROUND 10 TO 20 PERCENT OR
AROUND AN INCH OR TWO IN MOST LOCATIONS. OF NOTE...THE 07Z HRRR
BRINGS THE BACK EDGE OF THE STEADY PRECIPITATION TO RDU AT 21Z.
LATER SHIFTS WILL NEED TO MONITOR OBSERVATIONAL TRENDS AND ADJUST
FORECAST AS NEEDED. EVEN WITH TOTAL AMOUNTS DOWN A BIT...HAZARDOUS
TRAVEL CONDITIONS ARE EXPECTED.
IN ADDITION...LATEST GUIDANCE INCLUDING GFS AND SREF BUFR
SOUNDINGS WARM THE MID LEVELS MORE THAN PREVIOUS RUNS. THIS MORE
PROMINENT WARM NOSE MAKES MORE NORTHWEST PROGRESS AND SHOULD
RESULT IN LESS SNOW BUT A LARGER FRACTION OF SLEET AND FREEZING
RAIN.
GUIDANCE SUGGESTS THAT THE SIGNIFICANT PRECIPITATION WITH HOURLY
LIQUID EQUIVALENT RATES OF 0.05 TO 0.10 WILL EXPAND NORTHEAST
ACROSS THE RAH CWA THIS MORNING. THE PRECIPITATION WILL LIKELY BE
A LITTLE LIGHTER ACROSS THE EASTERN SANDHILLS AND SOUTHERN COASTAL
PLAIN THROUGH AT LEAST MID MORNING WITH THE STEADIER PRECIPITATION
ARRIVING LATE THIS MORNING AND AFTERNOON. INITIAL REPORTS INCLUDE
A FAIR AMOUNT OF SLEET AT THE ONSET...WITH TIME EARLY THIS MORNING
PRECIPITATION WILL BECOME MOSTLY SNOW IN THE TRIAD AND A MIX OF
SLEET AND SNOW IN THE TRIANGLE. FURTHER SOUTH...THE PRECIPITATION
HAS STARTED AS RAIN IN THE SOUTHERN TIER BUT COOLING FROM
EVAPORATION SHOULD RESULT IN A PERIOD OF FREEZING RAIN AND SLEET.
AS THE LOW AND MID LEVEL SOUTHERLY FLOW INCREASES...EXPECTED THE
PTYPE TO CHANGE TO RAIN IN THE COASTAL PLAIN AROUND OR JUST AFTER
MIDDAY. SNOW AND SLEET IN THE TRIANGLE WILL CHANGE TO SLEET AND
FREEZING RAIN IN THE EARLY AFTERNOON WHILE MOSTLY SNOW HOLDS ON
IN THE TRIAD. BY MID AFTERNOON MOSTLY FREEZING RAIN WILL BE
FALLING IN THE TRIANGLE WITH THE SNOW IN THE TRIAD MIXING WITH
SLEET. THE STEADIEST PRECIPITATION WILL LIKELY BE SHUTTING DOWN
FROM WEST TO EAST LATE THIS AFTERNOON AND EARLY THIS EVENING.
RESIDUAL MOISTURE AND SOME FORCING FOR ASCENT WILL CONTINUE THIS
EVENING AND OVERNIGHT. DEEP LAYER SATURATION WILL NOT EXTEND TO
ICE GLACIATION REGION WHICH WILL SHUT DOWN SNOW AND SLEET
OVERNIGHT BUT RESULT IN PERIODS OF FREEZING RAIN AND FREEZING
DRIZZLE.
STORM TOTAL SNOW AND SLEET ACCUMULATIONS IN THE TRIAD WILL RANGE
FROM 4 TO 8 INCHES IN THE TRIAD...LOCALLY MORE NORTH OF I-40 WITH
A TENTH OF AN INCH OF FREEZING RAIN. TO THE SOUTH AND EAST OF THE
IMMEDIATE TRIAD REGION...3 TO 5 INCHES OF SNOW AND SLEET ARE
EXPECTED ALONG WITH ICE ACCUMULATIONS AROUND A QUARTER OF AN INCH.
ACROSS MUCH OF THE TRIANGLE AND EASTERN PIEDMONT...SNOW AND SLEET
ACCUMULATION OF 2 TO 4 INCHES ARE EXPECTED WITH LOCALLY HEAVIER
AMOUNTS NORTH OF RALEIGH NEAR THE VIRGINIA BORDER. SNOW AND SLEET
ACCUMULATION ACROSS THE SOUTHERN PIEDMONT SHOULD TOTAL AN INCH OR
LESS. ICE ACCRUAL SHOULD TOTAL A QUARTER TO A THIRD OF AN INCH.
ACROSS THE EASTERN SANDHILLS AND COASTAL PLAIN...SNOW ACCUMULATION
OF UP TO AN INCH...ALONG WITH A TENTH TO TWO-TENTHS OF AN INCH OF
FREEZING RAIN ARE EXPECTED.
HIGH TEMPERATURES TODAY WILL RANGE INT THE UPPER 20S IN THE TRIAD
AREA TO TO THE UPPER 30S SOUTHEAST. TEMPERATURES WILL FALL ONLY
A COUPLE OF DEGREES TONIGHT. NORTHEAST WINDS WILL INCREASE THIS
MORNING REACHING 10- 20 MPH SUSTAINED WITH GUSTS TO AROUND 30 MPH.
WINDS WILL BACK AROUND TO NORTH THEN NORTHWEST TONIGHT. -BLAES
&&
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
AS OF 325 AM FRIDAY...
SAT/SAT NIGHT: WRAPAROUND PRECIP PRIMARILY IN THE FORM OF SNOW WILL
BE THE PRIMARY CONCERN HERE... WITH CONTINUED BRISK AND GUSTY WINDS
FROM THE NNW AND NW. MODELS ARE IN GOOD AGREEMENT WITH THE SURFACE
LOW OCCLUDING AS IT MOVES SLOWLY FROM JUST OFF NORFOLK ENE TO OFF
THE SOUTHERN NEW ENGLAND COAST BY SUN MORNING. ADDITIONAL QPF WILL
BE LIMITED BY THE WEAKER FORCING FOR ASCENT COMPARED TO TODAY`S DEEP
LAYER LIFT... BY SOME DRYING CONTRIBUTION FROM DOWNSLOPE LOW LEVEL
FLOW... AND BY THE THE MARGINAL AMOUNTS OF MOISTURE ABOVE -10C WHICH
BRINGS INTO QUESTION HOW MUCH ICE THERE WILL BE IN THE CLOUDS. OUR
BEST ESTIMATE IS ANOTHER ONE-HALF TO ONE-AND-A-HALF INCHES OF SNOW
MAINLY OVER THE NORTHERN PIEDMONT COUNTIES ON SAT... WITH THE
HIGHEST AMOUNTS AT THE VA BORDER. BASED ON THE AFOREMENTIONED
DOWNSLOPE FLOW AND THE LATEST FORECAST SOUNDINGS... EXPECT A BIT
QUICKER END TO PRECIP CHANCES FROM SW TO NE SAT EVENING AS COMPARED
TO THE PREVIOUS FORECAST... SUCH THAT LITTLE TO NO ADDITIONAL
ACCUMULATION IS ANTICIPATED AFTER 00Z SUNDAY. SKIES WILL GRADUALLY
CLEAR WEST TO EAST LATE. ANOMALOUSLY LOW THICKNESSES AND ABUNDANT
CLOUD COVER WILL HOLD SAT TEMPS DOWN TO LOWER-MID 30S. LOWS FROM THE
LOWER 20S WEST TO UPPER 20S EAST. DOWNWARD MOMENTUM TRANSPORT SHOULD
PUSH GUSTS PERIODICALLY UP TO 25-30 MPH... AND PERHAPS HIGHER IN THE
FAR NE CWA SAT AFTERNOON.
SUN THROUGH MON NIGHT: THE CLEARING TREND CONTINUES EARLY SUNDAY AS
THE STORM PULLS FURTHER OUT TO SEA AND BOTH SURFACE HIGH PRESSURE
AND MID LEVEL SHORTWAVE RIDGING BUILDING FROM THE WEST. EXPECT
MOSTLY SUNNY/MOSTLY CLEAR SKIES SUN/SUN NIGHT WITH CHILLY BUT SLOWLY
MODERATING TEMPS... PEAKING IN THE UPPER 30S (N) TO MID 40S (S) SUN
WITH LOWS IN THE UPPER TEENS TO MID 20S SUN NIGHT. THE RIDGE AXIS
FROM THE SURFACE UP THROUGH THE MID LEVELS SHIFTS OFF THE COAST MON
AND THE ENSUING ONSET OF WARM AIR ADVECTION (AHEAD OF THE NEXT STORM
SYSTEM) WILL LEAD TO INCREASING HIGH CLOUDS FROM WEST TO EAST...
PARTICULARLY MON NIGHT. TEMPS SHOULD RECOVER BACK CLOSER TO
NORMAL... WITH HIGHS FROM THE MID 40S TO LOWER 50S... AND MON NIGHT
LOWS IN THE MID-UPPER 30S. -GIH
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 205 AM FRIDAY...
SPLIT FLOW ALOFT WILL BECOME INCREASINGLY SO EARLY TO MID NEXT WEEK
OVER THE EASTERN NORTH PACIFIC AND WESTERN NOAM...AS NORTHERN STREAM
RIDGING THERE BECOMES INCREASINGLY AMPLIFIED. DOWNSTREAM...A
CORRESPONDING INCREASINGLY AMPLIFIED POSITIVELY-TILTED TROUGH ALOFT
WILL PROGRESS EAST...WITH SOME DEGREE OF PHASING POSSIBLE BETWEEN
THE STREAMS AS THE TROUGH APPROACHES THE EAST COAST. AN ASSOCIATED
SURFACE FRONTAL ZONE WILL ACCOMPANY THE APPROACHING TROUGH...WITH A
MODEL CONSENSUS TIMING OF THE PASSAGE OF THE FRONT -AND ASSOCIATED
BAND OF SHOWERS- LATE TUE OR TUE NIGHT.
THERE CONTINUES TO BE A SIGNAL IN NWP GUIDANCE OF CYCLOGENESIS ALONG
THE TAIL END OF THAT FRONT...FROM THE EASTERN GULF OF MEXICO TO
OFFSHORE THE SOUTHEAST US COAST...THOUGH MODEL SPREAD IN THE
EXISTENCE AND/OR TRACK OF THE LOW...AND ASSOCIATED FORECAST
UNCERTAINTY...IS VERY LARGE. WILL MAINTAIN RELATIVE CONTINUITY WITH
THE PREVIOUS RAH OFFICIAL FORECAST...WITH A CONTINUED SLIGHT-LOW
CHANCE OF PRECIPITATION TUE NIGHT-THU...WITH POST-FRONTAL DEEP-LAYER
COOLING SUPPORTIVE OF A MIX OR CHANGE TO SNOW -CONDITIONAL UPON
PRECIPITATION INDEED OCCURRING -OVER CLIMATOLOGICALLY-FAVORED AREAS
OF THE PIEDMONT...WHEN SURFACE TEMPERATURES ARE COLDEST DURING THE
MORNING AND NIGHTTIME HOURS WED.
&&
.AVIATION /09Z FRIDAY THROUGH TUESDAY/...
AS OF 105 AM FRIDAY...
HIGH CONFIDENCE THAT AVIATION CONDITIONS WILL QUICKLY DETERIORATE
FROM SW-NE ACROSS CENTRAL NC BETWEEN 09Z-14Z AS A MAJOR WINTER STORM
BEGINS TO AFFECT THE REGION. CEILINGS WILL GRADUALLY LOWER FROM LOW
END VFR TO MVFR CEILINGS THIS MORNING WHILE AREAS OF SNOW AND/OR
SLEET OVERSPREAD THE REGION FROM THE SW. THE SNOW AND SLEET WILL
CAUSE WIDESPREAD MVFR VISIBILITIES...WITH BRIEF PERIODS OF IFR
VISIBILITIES PROBABLE IN VICINITY OF THE KGSO AND KINT.
CONDITIONS WILL DETERIORATE FURTHER THIS AFTERNOON AS WIDESPREAD IFR
CONDITIONS WILL PREVAIL. WIDESPREAD SNOW MIXED WITH SLEET WILL
PERSIST IN VICINITY OF KGSO AND KINT WHILE FREEZING RAIN WILL BECOME
THE DOMINATE P-TYPE IN VICINITY OF KRDU AND KRWI. KFAY WILL
GRADUALLY TRANSITION FROM A PERIOD OF SLEET AND FREEZING RAIN THIS
MORNING TO A COLD RAIN THIS AFTERNOON. THE TRANSITION OT A COLD RAIN
MAY OCCUR AT KRWI BY LATE AFTERNOON.
THE ADVERSE AVIATION CONDITIONS WITH LOW CEILINGS AND WINTRY MIX
WILL PERSIST TONIGHT INTO SATURDAY. CONDITIONS WILL BEGIN TO SLOWLY
IMPROVE SATURDAY NIGHT WITH VFR CONDITIONS HIGHLY PROBABLE SUNDAY
AND MONDAY. A LOW PRESSURE SYSTEM APPROACHING FROM THE WEST WILL
BRING THE NEXT THREAT FOR ADVERSE AVIATION CONDITIONS ON
TUESDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR NCZ028-
043-078-089.
WINTER STORM WARNING UNTIL 6 PM EST SATURDAY FOR NCZ007>011-
021>026-038>041-073>077-083-084.
WINTER STORM WARNING UNTIL 6 PM EST THIS EVENING FOR NCZ027-
042-085-086-088.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...BLAES
SHORT TERM...HARTFIELD
LONG TERM...MWS
AVIATION...WSS
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1231 AM EST FRI JAN 22 2016
.SYNOPSIS...
HIGH PRESSURE WILL SHIFT NORTHEAST TONIGHT. LOW PRESSURE WILL THEN MOVE
INTO THE TENNESSEE VALLEY ON FRIDAY AND THEN WEAKEN IN THE
APPALACHIANS FRIDAY NIGHT AS ANOTHER LOW DEVELOPS ALONG THE MID
ATLANTIC COAST. HIGH PRESSURE WILL GRADUALLY BUILD IN DURING THE
WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
MAIN AREA OF CONCERN FOR THE FORECAST UPDATE THIS EVENING IS THE
SNOW POTENTIAL FOR TOMORROW. THE O Z NAM ALONG WITH THE 18 Z GFS
HAVE SHIFTED SLIGHTLY FURTHER NORTH WITH THE HIGHER PRECIP AMOUNTS.
THE LATEST RUNS OF THE RAP AND HRRR HAVE ALSO SHIFTED PRECIP
SLIGHTLY FURTHER NORTH. FOR NOW HAVE TRENDED POPS SLIGHTLY FURTHER
NORTH WITHOUT CHANGING THE HEADLINE CONFIGURATION.
PREV DISCUSSION->
HIGH PRESSURE CENTERED OVER OHIO WILL MOVE OFF TO THE NORTHEAST
TONIGHT. CLOUDS WILL INCREASE AND PRESSURE GRADIENT WILL TIGHTEN
IN ADVANCE OF APPROACHING STORM SYSTEM. SO EXPECT AN EARLY DROP IN
TEMPERATURES AND THEN STEADY TO SLOWLY RISING READINGS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY NIGHT/...
12Z GUIDANCE SUITE COMING INTO MORE AGREEMENT WITH IMPENDING
WINTER STORM. TREND HAS BEEN FOR PRECIPITATION SHIELD TO BE
SLOWER TO SPREAD IN FROM THE SOUTH. THIS WILL GRADUALLY MOVE
NORTH THROUGH THE DAY AS LOW PRESSURE MOVES INTO THE TENNESSEE
VALLEY. THUS HAVE SLOWED ONSET OF SNOW WITH MANY LOCATIONS NORTH
OF THE OHIO RIVER NOT BEGINNING UNTIL AFTERNOON.
BAND OF FRONTOGENESIS DEVELOPS INTO SOUTHERN SECTIONS LATE IN THE
DAY AND PERSISTS INTO THE EVENING BEFORE WEAKENING AS THE SURFACE
LOW DISSIPATES ON THE WEST SIDE OF THE APPALACHIANS AND ENERGY
TRANSFERS TO THE COAST. THIS WILL LEAD TO A PERIOD OF MODERATE TO
HEAVY SNOW ACROSS THE FAR SOUTHEAST COUNTIES. MEANWHILE THERE WILL
ALSO BE A VERY SHARP GRADIENT ON THE NORTHERN EDGE OF THE SYSTEM
THAT WILL PIVOT SLIGHTLY FRIDAY NIGHT AS ENTIRE SYSTEM MOVES
EAST. FELT CONFIDENT ENOUGH WITH CONSENSUS AMONGST GUIDANCE TO
INCLUDE A SHARP CUT OFF BOTH TO SNOW AND MORE SIGNIFICANT
SNOWFALL. THIS WILL RESULT IN NORTHWEST COUNTIES REMAINING DRY
THROUGH THE ENTIRE EVENT.
THIS GRADIENT LEADS TO SOME DIFFICULT DECISIONS REGARDING WINTER
WEATHER PRODUCTS AS SEVERAL COUNTIES HAVE A VERY LARGE RANGE FROM
SOUTH TO NORTH. FOR THE MOST PART HAVE USED HIGHER END OF THE
ACCUMULATIONS WITHIN EACH COUNTY TO TRIGGER HEADLINES.
SNOW WILL BE WINDING DOWN LATE FRIDAY NIGHT BUT STILL CONTINUE
INTO SATURDAY MORNING BEFORE ENDING IN THE EASTERN COUNTIES. NORTH
TO NORTHEAST WINDS WILL BECOME A BIT GUSTY AS SNOW COMES TO AN
END. CLOUDS AND WINDS WILL DECREASE SATURDAY AFTERNOON INTO
SATURDAY NIGHT AS HIGH PRESSURE STARTS TO BUILD IN. HAVE GONE
SIGNIFICANTLY BELOW GUIDANCE FOR LOWS SATURDAY NIGHT WHERE THERE
IS THE HIGHEST CONFIDENCE OF A DEEP SNOW PACK.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
HIGH PRESSURE WILL BE SITUATED JUST SE OF THE FA AT THE START OF THE
LONG TERM. SOUTHERLY FLOW WILL DEVELOP AND BRING WARMER
TEMPERATURES TO THE REGION SUNDAY AND MONDAY. HIGH TEMPERATURES
ACROSS MOST LOCATIONS WILL BE IN THE 30S BOTH DAYS.
A SYSTEM WILL APPROACH THE AREA ON MONDAY. PRECIPITATION WILL START
OUT AS RAIN ACROSS MOST LOCATIONS. PRECIPITATION WILL START TO
CHANGE OVER TO SNOW MONDAY NIGHT AS THE COLD FRONT WORKS INTO THE
REGION AND COLDER AIR FILTERS IN. SNOW SHOWERS WILL TAPER OFF
DURING THE DAY ON TUESDAY.
A COUPLE OF ADDITIONAL DISTURBANCES WILL MOVE THROUGH ON WEDNESDAY
AND THURSDAY. PRECIPITATION WILL GENERALLY BE IN THE FORM OF SNOW
SHOWERS WITH THESE EVENTS.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS WILL CONTINUE THROUGH THE FIRST HALF OF THE
FORECAST PERIOD...WITH GRADUALLY LOWERING CLOUDS...AND INCREASING
NORTHEASTERLY WINDS. BY AFTERNOON...THE IMPACTS FROM A SIGNIFICANT
WINTER STORM WILL BEGIN TO SPREAD NORTH TOWARD THE REGION. IN
AGREEMENT WITH THE PREVIOUS FORECAST...THE CVG/LUK AIRPORTS HAVE
THE GREATEST CHANCE TO EXPERIENCE ACCUMULATING SNOWFALL AND A
LENGTHY PERIOD OF REDUCED AVIATION CONDITIONS. IFR VISIBILITIES
ARE A NEAR CERTAINTY...ESPECIALLY BETWEEN 22Z-02Z. SNOW IS ALSO
EXPECTED FOR ILN/CMH/LCK...BUT THE DURATION AND INTENSITY OF THE
SNOW REMAINS VERY MUCH IN QUESTION...AND IFR CONDITIONS ARE NOT
SURE TO OCCUR. DAY APPEARS LIKELY TO REMAIN DRY.
BY LATE FRIDAY EVENING...AS WINDS SHIFT TO THE
NORTH-NORTHEAST...MVFR CEILINGS ARE LIKELY TO DEVELOP AT ALL OF
THE TAF SITES. THESE CEILINGS WILL CONTINUE THROUGH THE END OF THE
FORECAST PERIOD.
NOTE THAT ANY ADDITIONAL CHANGES TO THE FORECAST TRACK OF THIS
WINTER STORM COULD SPREAD MORE OR LESS SNOW INTO THE
REGION...WHICH WOULD HAVE IMPACTS ON VISIBILITY AND CEILING
FORECASTS.
OUTLOOK...MVFR/IFR CONDITIONS MAY CONTINUE INTO SATURDAY AS SNOW
EXITS THE REGION. MVFR/IFR CONDITIONS ARE POSSIBLE AGAIN MONDAY
NIGHT INTO TUESDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 7 AM EST
SATURDAY FOR OHZ063>065-072-077.
WINTER STORM WARNING FROM 1 PM THIS AFTERNOON TO 7 AM EST
SATURDAY FOR OHZ073-074-078-080.
WINTER STORM WARNING FROM 10 AM THIS MORNING TO 7 AM EST
SATURDAY FOR OHZ079-082.
WINTER STORM WARNING FROM 7 AM THIS MORNING TO NOON EST
SATURDAY FOR OHZ081-088.
KY...WINTER STORM WARNING FROM 1 PM THIS AFTERNOON TO 7 AM EST
SATURDAY FOR KYZ089>093.
WINTER STORM WARNING FROM 10 AM THIS MORNING TO 7 AM EST
SATURDAY FOR KYZ094>097.
WINTER STORM WARNING FROM 7 AM THIS MORNING TO NOON EST
SATURDAY FOR KYZ098>100.
IN...WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 7 AM EST
SATURDAY FOR INZ075-080.
&&
$$
SYNOPSIS...HAINES
NEAR TERM...HAINES
SHORT TERM...
LONG TERM...NOVAK
AVIATION...HATZOS
AREA FORECAST DISCUSSION
NWS NORMAN OK
259 AM CST FRI JAN 22 2016
.DISCUSSION...
AFTER TODAY...WARMER WEATHER CAN BE EXPECTED. A DRY AND RATHER
QUIET WEATHER PATTERN IS EXPECTED FOR THE NEXT SEVEN DAYS.
TODAY WILL BE ANOTHER COLD DAY. CLOUD COVER REMAINS A BIT
TRICKY. FOLLOWED THE LATEST HRRR CEILING PRODUCT TO DEPICT CLOUD
COVER TODAY AND TONIGHT...WHICH GENERALLY DEPICTED CLOUD COVER
DECREASING ACROSS THE AREA...ESPECIALLY DURING THIS AFTERNOON AND
EVENING. APPEARS THE CLOUDS MAY HANG ON LONGEST NEAR ENID AND
MEDFORD IN PARTS OF NORTHERN OKLAHOMA. A STRAY SNOW FLURRY COULD
OCCUR NEAR PONCA CITY AND MEDFORD THIS MORNING...BUT DID NOT
MENTION DUE TO LOW CONFIDENCE OF OCCURRENCE. MODEL GUIDANCE HIGH
TEMPERATURES RANGING FROM THE MID 30S NEAR PONCA CITY TO NEAR 50
IN FAR WESTERN NORTH TEXAS NEAR KNOX CITY SEEMED REASONABLE AND
WERE FOLLOWED. WINDS WILL SLOWLY DIMINISH THIS AFTERNOON...THEN
RAPIDLY AFTER SUNSET.
TONIGHT...WENT WITH THE COLDER SIDE OF GUIDANCE LOWS TOWARDS THE
00Z METMOS NUMBERS THINKING CLEAR SKIES AND LIGHT WINDS WILL ALLOW
FOR GOOD RADIATIONAL COOLING.
SATURDAY WILL BE MOSTLY SUNNY AND WARMER WITH SURFACE WINDS SLOWLY
SHIFTING TO THE SOUTH.
SUNDAY WILL BE BREEZY TO WINDY AND WARMER YET. THINK MANY
LOCATIONS WILL GET ABOVE THE 60 DEGREE MARK. THE STRONGER WINDS
MAY ELEVATE FIRE WEATHER CONCERNS...THOUGH LOW LEVEL DEWPOINTS
WILL BE INCREASING THROUGHOUT THE DAY.
SUNDAY NIGHT INTO EARLY MONDAY...A COLD FRONT WILL MOVE THROUGH
THE AREA BRINGING A WIND SHIFT. MOISTURE APPEARS TO BE
LIMITED...SO KEPT A DRY FORECAST.
MONDAY THROUGH THURSDAY...DRY CONDITIONS WITH TEMPERATURES AT OR
ABOVE AVERAGE TEMPERATURES ARE FORECAST. A FEW WEAK COLD FRONTS
MAY MOVE THROUGH THE AREA AND BRING SURFACE WIND SHIFTS AS WELL
AS SMALL CHANGES IN TEMPERATURES EACH DAY.
MBS
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 38 21 48 32 / 0 0 0 0
HOBART OK 42 21 50 33 / 0 0 0 0
WICHITA FALLS TX 46 24 54 34 / 0 0 0 0
GAGE OK 43 16 54 30 / 0 0 0 0
PONCA CITY OK 34 13 47 30 / 0 0 0 0
DURANT OK 43 25 50 31 / 0 0 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
25/17
AREA FORECAST DISCUSSION
NWS PENDLETON OR
927 PM PST THU JAN 21 2016
UPDATED AVIATION DISCUSSION
.SHORT TERM...TONIGHT AND FRIDAY...A COLD FRONT ALONG THE COAST WILL
SLOWLY MOVE EAST THROUGH THE REGION LATE TONIGHT AND FRIDAY. AS IT
DOES WE WILL SEE SOME INCREASING RAIN LATE TONIGHT THROUGH EARLY
FRIDAY WITH SNOW LEVELS AROUND 6000 FEET LOWERING TO 4500 FEET
FRIDAY AFTERNOON. SOUTHERLY WINDS AHEAD OF THE FRONT WILL CREATE
SOME BREEZY CONDITIONS FOR PORTIONS OF THE FORECAST AREA AND VERY
WIND IN THE SOUTHERN GRANDE RONDE VALLEY WHERE A WIND ADVISORY IS IN
EFFECT. MADE SOME MINOR CHANGES TO WINDS...TEMPERATURES AND CHANCE
OF PRECIPITATION IN THE FORECAST UPDATE.
.AVIATION...06Z TAFS...VFR CONDITIONS ARE MAINLY EXPECTED THROUGH
THE NEXT 24 HOURS BUT SOME MVFR CONDITIONS WILL BE POSSIBLE
OVERNIGHT THROUGH EARLY FRIDAY AS A BAND OF PRECIPITATION PASSES
THROUGH THE REGION. WINDS WILL BE LESS THAN 10 KTS EXCEPT AT KALW,
KPDT, KRDM AND KBDN WHERE GUSTIER DOWN SLOPE WINDS WILL BE POSSIBLE
AT TIMES.
&&
.PREV DISCUSSION... /ISSUED 344 PM PST THU JAN 21 2016/
SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT...PATCHY LIGHT RAIN IS
SHOWING ON RADAR FROM A WARM FRONT THAT IS LIFTING NORTHEAST ACROSS
THE AREA THIS AFTERNOON. THIS PART IF THE PRECIPITATION IS
DISORGANIZED ON RADAR AND MODELS EXCEPT THE HRRR HAVE INDICATED THAT
IT SHOULD HAVE ALREADY ENDED. THE NEXT BAND OF PRECIPITATION WILL
MOVE EAST OF THE CASCADES TONIGHT AS THE COLD FRONT MOVES ONSHORE.
I MAY MAKE LAST MINUTE ADJUSTMENT TO KEEP LIGHT RAIN OVER SOUTHEAST
WASHINGTON RATHER THAN SHOWING A BREAK BETWEEN THE BANDS SHOWN BY
THE MODELS. STRONG SOUTHERLY WINDS DUE TO FUNNELING ARE OCCURRING IN
THE THE SOUTHERN GRANDE RONDE VALLEY WHERE A WIND ADVISORY HAS BEEN
ISSUED. LOCALLY BREEZY WINDS ARE OCCURRING IN THE NORTHEAST OREGON
MOUNTAINS AND FOOTHILLS AS WELL. THE COLD FRONT WILL BE SLOW TO MOVE
INLAND. RAIN AND MOUNTAIN SNOW WILL SPREAD ACROSS THE REGION...AND
SNOW LEVELS WILL FALL TO 4000-5000 FT BY FRIDAY AFTERNOON. THIS
SYSTEM MOVES OUT FRIDAY EVENING BUT ANOTHER ONE MOVES INTO OREGON TO
SPREAD ANOTHER ROUND OF PRECIPITATION WITH LOWER SNOW LEVELS...
AROUND 2000 FT ON THE EAST SLOPES OF THE CASCADES AND 3000-4000 FT
ELSEWHERE BY SATURDAY MORNING. ANOTHER BETWEEN 4000 AND 5000 FEET
FRIDAY AFTERNOON. TEMPERATURES ON SATURDAY WILL ALSO BE LOWER AND
CLOSER TO NORMAL FOR THIS TIME OF YEAR WITH DAYTIME HIGHS IN THE MID
30S TO MID 40S. COONFIELD
LONG TERM...SUNDAY THROUGH THURSDAY...AN UNSETTLED WEATHER PATTERN
IS GENERALLY EXPECTED THROUGH THIS PERIOD. THE FLOW LOOKS TO BE
SOMEWHAT AMPLIFIED INTO EARLY NEXT WEEK. THUS COULD SEE A MOSTLY DRY
DAY MONDAY AFTER LINGERING SHOWERS ON SUNDAY AND SUNDAY NIGHT. THERE
COULD BE SOME PATCHY FOG AT SOME LOWER ELEVATIONS MONDAY MORNING,
BUT FOR NOW WILL CONTINUE TO ONLY MENTION IN THE GORGE AND THE
KITTITAS VALLEY. ANOTHER SYSTEM LOOKS TO APPROACH THE AREA MONDAY
NIGHT AND TUESDAY, BUT THERE ARE CURRENTLY TIMING DIFFERENCES
BETWEEN THE VARIOUS MID RANGE MODELS. DID SLOW THE ARRIVAL TIMING OF
THIS SYSTEM ON MONDAY NIGHT. OTHER THAN LOWERING POPS ALONG OUR
SOUTHERN BORDER, WILL LEAVE THE TUESDAY INTO WEDNESDAY FORECASTS
LARGELY AS INHERITED. THE FLOW COULD POTENTIALLY BECOME LESS
AMPLIFIED BY LATE WEEK AND WILL CONTINUE THE CURRENT CHANCE TO
LOCALLY LIKELY POPS FOR THURSDAY. 90
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 43 52 34 45 / 20 60 20 50
ALW 43 52 36 46 / 20 60 20 50
PSC 39 49 37 45 / 20 60 20 50
YKM 34 43 34 43 / 60 60 40 50
HRI 41 50 36 46 / 20 60 20 50
ELN 33 40 31 40 / 60 60 40 60
RDM 39 49 34 44 / 30 60 50 50
LGD 38 45 34 44 / 10 40 20 50
GCD 35 46 33 42 / 10 60 30 60
DLS 41 50 38 47 / 60 60 50 60
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...WIND ADVISORY UNTIL 3 PM PST FRIDAY FOR ORZ049.
WA...AIR STAGNATION ADVISORY UNTIL 10 AM PST FRIDAY FOR WAZ027.
&&
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
91/91/91
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1031 PM CST THU JAN 21 2016
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 320 PM CST THU JAN 21 2016
MAIN FORECAST CONCERN IS THE SNOW THIS EVENING AND THEN HOW LONG THE
LOW CLOUDS REMAIN LATER TONIGHT AND TOMORROW.
STRONG UPPER WAVE CURRENTLY IN CENTRAL SD. FAIRLY WIDESPREAD LIGHT
SNOW HAS BEEN FALLING SINCE MID MORNING OVER MUCH OF EAST CENTRAL
SOUTH DAKOTA INTO PARTS OF SOUTHWEST MINNESOTA. A PERSISTENT
AREA OF SNOW DEVELOPED NEAR THE BUFFALO RIDGE FROM WATERTOWN
DOWN INTO LINCOLN COUNTY MINNESOTA. BY MID AFTERNOON THERE WERE
REPORTS OF 2 TO 4 INCHES IN LINCOLN COUNTY WHILE OTHER AREAS HAVE
GENERALLY BEEN LESS THAN 2 INCHES. EXPECTATION IS THAT THIS BAND OF
SNOW WILL PERSIST UNTIL THE UPPER LEVEL WAVE MOVES EAST LATER THIS
EVENING. BASED UPON THE RAP AND SATELLITE...THIS SHOULD END SNOW
NEAR I29 SHORTLY AFTER 00Z AND AROUND KMML BETWEEN 03Z AND 06Z.
LAST OF SNOW SHOULD EXIT COTTONWOOD...JACKSON...AND DICKINSON COUNTY
IOWA BY 09Z. ALONG HWY 14 BETWEEN MARSHALL AND BROOKINGS...ANOTHER
1 TO 2 INCHES OF SNOW IS EXPECTED BRINGING TOTALS TO 4 TO 5 INCHES.
ANOTHER 1 TO 2 INCHES ALSO POSSIBLE AROUND SLAYTON AND WINDOM WHERE
TOTALS WILL BE 1 TO 3 INCHES. ALONG AND SOUTH OF I-90...IN
SOUTHEAST SD AND NORTHWEST IOWA...BAND OF SNOW IS MUCH MORE NARROW
AND PROGRESSIVE SO ANY SNOWFALL WILL LAST ON A FEW HOURS. SNOWFALL
WILL GENERALLY BE LESS THAN AN INCH WITH LITTLE OR NO SNOW AROUND
SIOUX CITY.
SURFACE RIDGE IS EXPECTED TO MOVE SOUTH AND SETTLE ALONG THE WESTERN
MINNESOTA BORDER. NORTHERLY FLOW TONIGHT WILL GRADUALLY WEAKEN LATE.
THIS WILL BRING SOME COOLER AIR INTO THE REGION. HOWEVER...WITH LOW
CLOUDS EXTENDING TO THE INTERNATIONAL BORDER...AM PESSIMISTIC THAT
CLOUDS WILL ADVECT OUT OF THE AREA BEFORE THE SURFACE RIDGE ARRIVES
AND WINDS ALOFT DIMINISH LATER TONIGHT. AFTER THAT...REALLY RELYING
ON SUBSIDENCE TO ERODE CLOUDS. IN THE PAST...THIS HAS BEEN A SLOW
PROCESS TO OCCUR. FOR THAT REASON...EXPECTING SKIES TO REMAIN CLOUDY
ACROSS THE AREA ALL OF TONIGHT WITH BREAKS ONLY SLOWLY DEVELOPING
NORTH OF I90 DURING FRIDAY. THEREFORE...HAVE RAISED MINS TO 1O TO 15
ABOVE SOUTH OF I90 AND 5 TO 10 ABOVE NORTH OF I90. WITH CLOUDS AND
COOLER AIR MASS HIGHS WILL BE BELOW NORMAL WITH TEENS EAST OF THE
JAMES RIVER...AND 20S WEST OF THE JAMES RIVER.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 320 PM CST THU JAN 21 2016
MID-RANGE PORTION OF THE FORECAST WILL FEATURE QUIET CONDITIONS WITH
RELATIVELY MILD TEMPERATURES FOR THE WEEKEND AS UPPER RIDGE BUILDING
INTO THE CENTRAL CONUS ALLOWS WARMER AIR ALOFT TO WORK EASTWARD. AS
IS TYPICAL THIS TIME OF YEAR WITH A DECENT SNOW COVER...FULL EXTENT
OF WARMING WILL NOT BE REALIZED AT THE SURFACE...THOUGH LOCATIONS
WEST OF THE JAMES RIVER VALLEY STAND A STRONG CHANCE OF WARMING
ABOVE FREEZING FOR SEVERAL HOURS ON SATURDAY. WARMING WILL ACTUALLY
BEGIN LATE FRIDAY NIGHT...AS SURFACE RIDGE IN EASTERN FORECAST AREA
EARLY IN THE EVENING SHIFTS EAST...AND AN INCREASE IN SOUTH WINDS
AND THICKER CLOUD COVER BRINGS STEADY TO SLOWLY RISING TEMPERATURES.
CLOUDS WILL STICK AROUND MOST AREAS ON SATURDAY...BUT DECENT MIXING
IN THE STOUT SOUTHERLY FLOW AHEAD OF WEAK COOL FRONT SHOULD HELP
TEMPS WARM INTO THE UPPER 20S-MID 30S ALONG/EAST OF THE JAMES RIVER.
FARTHER WEST...OUR SOUTHWEST CORNER SHOULD SEE A SWITCH TO LIGHTER
WESTERLY FLOW BEHIND THE FRONT...BUT SLIGHT COOLING ALOFT SHOULD
LEAD TO DEEPER MIXING AND HELP WARM HIGHS INTO THE LOWER 40S. COOL
FRONT WORKS THROUGH SATURDAY NIGHT/SUNDAY...BECOMING A STATIONARY
BOUNDARY NEAR SOUTHEAST CWA BY LATE SUNDAY AS STRONGER SYSTEM DIGS
INTO THE CENTRAL PLAINS.
THIS LATE WEEKEND SYSTEM WILL BE OUR NEXT SNOW-PRODUCER FOR EARLY
NEXT WEEK. MODELS PRIOR TO TODAY HAVE BEEN ALL OVER THE PLACE WITH
TIMING/TRACK/STRENGTH OF THIS SYSTEM...BUT NOW THAT POWERFUL EAST
COAST SYSTEM IS COMING INTO CLEARER FOCUS...MODELS HAVE COME INTO
BETTER AGREEMENT ON THE NEXT TROUGH WHICH WILL DIVE THROUGH THE
ROCKIES EARLY NEXT WEEK. 12Z RUNS OF GFS/GEM/ECMWF ALL POINTING TO
CYCLOGENESIS SOMEWHERE IN THE OKLAHOMA PANHANDLE VICINITY BY SUNDAY
EVENING...THEN TRACKING THAT SURFACE LOW TOWARD THE MID-MISSISSIPPI
VALLEY BY LATE MONDAY. WITH FAIRLY GOOD AGREEMENT ON PLACEMENT AND
TIMING OF KEY FEATURES...COORDINATED WITH SURROUNDING OFFICES TO
BUMP POPS INTO LIKELY RANGE ACROSS OUR WEST SUNDAY NIGHT...AND FOR
CENTRAL/EASTERN PORTIONS OF THE FORECAST AREA ON MONDAY. UNCERTAIN
AT THIS POINT HOW MUCH PRECIPITATION/SNOW WILL FALL...BUT MAY HAVE
TO WATCH FOR SOME BANDED PRECIP AS ALL HINTING AT ZONE OF STRONGER
MID-LEVEL FRONTOGENESIS SLIDING ACROSS THE AREA LATE SUNDAY NIGHT
INTO MONDAY. WINDS INITIALLY NOT TOO STRONG...BUT AS LOW BECOMES A
BIT MORE WRAPPED UP ON MONDAY...EXPECT TO SEE AN INCREASE IN NORTH
WINDS WHICH COULD ALSO PRODUCE SOME BLOWING SNOW CONCERNS. AS FAR AS
TEMPERATURES...WILL SEE COOLER AIR MOVE BACK IN FOR MONDAY/TUESDAY
BUT JUST SLIGHTLY BELOW NORMAL.
RETURN TO SOMEWHAT MORE MILD WEST-NORTHWEST FLOW PATTERN SETS UP FOR
MID-LATE NEXT WEEK...BUT WITH LACK OF MODEL AGREEMENT IN TIMING OF
VARIOUS WAVES MOVING THROUGH THE FLOW...SEEING LARGE DIFFERENCES IN
PRECIP TIMING AND LOW LEVEL TEMPERATURE TRENDS. THUS OPTED TO STICK
CLOSE TO BROAD MODEL CONSENSUS FOR OUR WEDNESDAY/THURSDAY PERIODS
FOR NOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1026 PM CST THU JAN 21 2016
SNOW SLOWLY PUSHING EAST OF THE TERMINALS AS WE APPROACH MIDNIGHT.
LINGERING FLURRIES MAY BE POSSIBLE AT FSD/SUX...HOWEVER
ACCUMULATING SNOWS ARE OVER.
BIGGEST CHALLENGE INTO FRIDAY WILL BE DEALING WITH CEILINGS.
CLEARING OR THINNING OF THE LOW CLOUDS CONTINUES TO TRACK
SOUTHWARD ALONG THE I-29 CORRIDOR. GUIDANCE CONTINUES TO SUGGEST
THAT WE MAY JUMP REPEATEDLY FROM VFR TO MVFR/IFR INTO FRIDAY
MORNING...ESPECIALLY AT FSD/SUX. HURON WILL REMAIN ON THE WESTERN
PERIPHERY OF THE INCOMING HIGH...AND SHOULD SEE A MORE PREVAILING
MVFR DECK INTO FRIDAY. WHEREVER CLOUDS MAY THIN TEMPERATURES
SHOULD DROP AND FOG PROBABILITIES MAY INCREASE.
LOW CONFIDENCE FORECAST FROM FRIDAY AFTERNOON ONWARD. DECENT
PROBABILITIES THAT LOWER CEILINGS RETURN BY SUNSET.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...SCHUMACHER
LONG TERM...JH
AVIATION...DUX
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
344 AM CST FRI JAN 22 2016
.DISCUSSION...
FROZEN PRECIPITATION BEGAN LATE YESTERDAY EVENING IN THE FAR
NORTHWEST ZONES AFTER RAINFALL EARLIER YESTERDAY. CKV REPORTED
ABOUT A TENTH OF AN INCH OF ICE FROM FZRA SO FAR THIS
EVENING...BUT SHOULD SWITCH OVER TO SNOW WITHIN THE NEXT FEW
HOURS. CURRENT LOCATION OF THE SURFACE LOW IS IN WEST CENTRAL
ALABAMA...NEAR TUSCALOOSA. ITS PATH HAS BEEN NEARLY NNE FROM THE
GULF SO FAR DURING THE OVERNIGHT HOURS. CURRENT FORECAST DEPENDS
ON THE SURFACE LOW TRACKING A BIT FURTHER EAST...ALLOWING COLD AIR
TO FILTER IN BEHIND AND MAKE SNOW THE DOMINANT PRECIP TYPE FOR THE
AREA BY THIS AFTERNOON. IF THE SURFACE LOW TRACKS FURTHER
WEST...AREAS EAST OF NASHVILLE AND ESPECIALLY SOUTHEAST MAY SEE
MORE RAIN FOR A LONGER DURATION. THIS WILL CUT INTO THE CURRENT
FORECASTED SNOW AMOUNTS FOR THAT AREA.
LOOKING AT CURRENT OBS OVERNIGHT...TEMPERATURES HAVE TRENDED A BIT
COOLER THAN PREVIOUSLY FORECASTED...SO ADJUSTED TEMPS TODAY
ACCORDINGLY. DRY SLOT HAS JUST CREPT INTO THE SOUTHWEST PART OF
THE CWA AND SHOULD IMPACT MOST OF THE AREA BEFORE THE NEXT ROUND
OF PRECIP MOVES IN. FOR THE MOST PART...DID NOT CHANGE TRANSITION
OF PRECIP TYPES FROM THE PREVIOUS FORECAST. CURRENT THINKING IS TO
HAVE THE SWITCH OVER TO ALL SNOW FOR CKV BY 12Z...NASHVILLE
SHORTLY AFTER NOON...AND CSV AFTER 21Z. STILL DIFFICULT ON TIMING
FOR THE TRANSITION TO FROZEN PRECIP AND EVENTUALLY SNOW AS MODELS
STILL DISAGREE SLIGHTLY. HRRR IS CURRENTLY CLOSEST TO OBS WITH THE
COOLER TREND...SO TRIED TO STICK CLOSE TO THE HRRR WITH TEMPS AND
THE TRANSITION. BEFORE THE TRANSITION TO ALL SNOW...WE SHOULD SEE
A MIX OF FZRA...SLEET...AS WELL AS RAIN AND SNOW ACROSS THE AREA.
AS FOR SNOW AMOUNTS...HAVE THE NORTHERN AND CENTRAL PARTS OF THE
MID STATE WITH A BIT MORE SNOW THAN THE PREVIOUS FORECAST. CURRENT
HIGH SNOW AMOUNT FOR THE AREA IS AROUND 10 INCHES IN STEWART AND
MONTGOMERY COUNTIES. WITH THE COOLER TREND TO TEMPERATURES...IT IS
POSSIBLE FOR THIS AREA TO SEE SNOW THE LONGEST AND THUS RAISED
SNOW AMOUNTS. NASHVILLE AREA LOOKS TO BE BETWEEN 4 AND 5
INCHES...WHICH IS RIGHT NEAR THE MODEL CONSENSUS FOR SNOW AMOUNTS.
AREAS IN THE FAR SOUTH NEAR THE AL BORDER DIDNT SEE MUCH OF AN
INCREASE...BUT AMOUNTS IN WAYNE AND LAWRENCE COUNTIES ARE CLOSE TO
WARNING CRITERIA. MAY NEED TO UPGRADE THOSE COUNTIES FROM AN
ADVISORY IF TEMPS DROP A BIT SOONER AND OBVIOUSLY SNOW ONSET COMES
IN SOONER AS WELL.
LATER ON THIS EVENING HEAVIER SNOW SHOULD BE EAST OF I65 AND
MAINLY ON THE PLATEAU. BY THE OVERNIGHT HOURS INTO SATURDAY
MORNING...THE UPPER LOW SHOULD BE EAST OF THE REGION AND WRAP
AROUND SNOW SHOULD BE LIGHT ON THE PLATEAU. HIGH TEMPERATURES
SATURDAY SHOULD STAY BELOW FREEZING LARGELY DUE TO THE SNOW COVER
BUT ALSO WITH CAA BEHIND THE LOW. SATURDAY NIGHT INTO SUNDAY...LOW
TEMPERATURES ARE CURRENTLY IN THE SINGLE DIGITS AND TEENS ACROSS
THE AREA...BUT MAY NEED TO DROP FURTHER IF SNOWPACK IS AS DEEP AS
THE FORECAST SUGGESTS.
NEXT CHANCE FOR PRECIP LOOKS TO BE ON MONDAY AS AN UPPER SHORTWAVE
MOVES THROUGH THE MIDWEST AND CLIPS THE REGION. KEPT WEDNESDAY AND
THURSDAY DRY BEFORE MORE PRECIP MAY CLIP THE PLATEAU THURSDAY
NIGHT INTO FRIDAY. TEMPERATURES NEXT WEEK SHOULD MAINLY BE
SLIGHTLY BELOW NORMALS WHICH ARE IN THE MID TO UPPER 40S...WITH
EXCEPTION TO NEXT FRIDAY. CURRENT FORECAST HAS HIGHS ABOVE AVERAGE
ON MONDAY...BUT SNOW COVER MAY KEEP TEMPS RIGHT AROUND AVERAGE.
&&
.AVIATION...
06Z TAF DISCUSSION.
FLYING CONDITIONS GOING DOWNHILL FAST TONIGHT AS SURFACE LOW NOW
MOVING INTO EAST CENTRAL MISSISSIPPI HAS SPREAD RAIN NORTHWARD
ACROSS JUST ABOUT ALL OF MIDDLE TENNESSEE WITH LOW CEILINGS
DEVELOPING QUICKLY. LOOKING FOR WINTRY MIX IN NORTHWEST AFTER
MIDNIGHT CHANGING TO SNOW JUST BEFORE DAYBREAK WITH SNOW
CONTINUING DURING THE DAY FRIDAY. AS FOR NASHVILLE THINK RAIN
MOSTLY THROUGH THE OVERNIGHT HOURS THEN CHANGE TO SNOW AROUND 15Z
AND CONTINUE DURING THE DAY. CROSSVILLE WILL REMAIN LIQUID THROUGH
21Z FRIDAY THEN CHANGE TO SNOW AND CONTINUE THROUGH A GOOD PART OF
FRIDAY NIGHT. NEEDLESS TO SAY FLYING CONDITIONS WILL NOT BE GOOD
FOR THE NEXT 24 HOURS.
&&
.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE 34 24 31 15 38 / 100 80 10 0 0
CLARKSVILLE 30 22 30 11 37 / 100 60 10 0 0
CROSSVILLE 35 22 27 12 38 / 100 100 50 10 0
COLUMBIA 35 23 31 17 40 / 100 70 10 0 0
LAWRENCEBURG 37 24 31 19 41 / 100 80 10 0 0
WAVERLY 32 22 31 14 38 / 100 60 10 0 0
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL NOON CST SATURDAY FOR CLAY-FENTRESS-
JACKSON-OVERTON-PICKETT.
WINTER WEATHER ADVISORY FROM 6 AM THIS MORNING TO 6 AM CST
SATURDAY FOR BEDFORD-COFFEE-GILES-LAWRENCE-MARSHALL-WAYNE.
WINTER STORM WARNING FROM 6 AM THIS MORNING TO NOON CST SATURDAY
FOR CUMBERLAND-GRUNDY-PUTNAM-VAN BUREN-WARREN-WHITE.
WINTER STORM WARNING FROM 6 AM THIS MORNING TO 6 AM CST SATURDAY
FOR CANNON-CHEATHAM-DAVIDSON-DE KALB-DICKSON-HICKMAN-HOUSTON-
HUMPHREYS-LEWIS-MAURY-PERRY-RUTHERFORD-SMITH-WILLIAMSON-WILSON.
WINTER STORM WARNING UNTIL 6 AM CST SATURDAY FOR MACON-
MONTGOMERY-ROBERTSON-STEWART-SUMNER-TROUSDALE.
&&
$$
SHORT TERM/AVIATION........55/SHAMBURGER
LONG TERM..................06/BARNWELL
AREA FORECAST DISCUSSION...CORRECTED
NWS NASHVILLE TN
1020 PM CST THU JAN 21 2016
.DISCUSSION...
JUST REISSUED THE ZONES. LATEST CHANGES INCLUDE THE 2ND PERIOD.
MODELS CONTINUE TO LEAN TOWARD A QUICKER TRANSITION OVER TO SNOW
IN THE MORNING. SHOULD BE ALL SNOW ACROSS ROUGHLY THE NORTHWEST
HALF OF THE MID STATE BY NOON.
REGIONAL RADAR SHOWS THE POSITIONING OF THE UPPER LOW. ITS
CURRENTLY LOCATED OVER NORTHERN LOUISIANA. THIS FEATURE IS STILL
EXPECTED TO TRACK TOWARD THE EAST AND WILL CROSS NORTHERN AL IN
THE MORNING. STRONG SFC LOW WILL BE DISPLACED ABOUT 100 MILES OR SO
EAST OF THE UPPER LOW. SO...SHOULD SEE GOOD LOWER LEVEL CAA FEED
INTO THAT DEVELOPING DEFORMATIONAL AREA.
AT ANY RATE...SNOW TOTALS DID CLIMB ABOUT AN INCH ACROSS THE WESTERN
HALF OF THE AREA...DUE TO THE EXPECTED FASTER TRANSITION OVER TO ALL
SNOW.
FOR THE 1ST PERIOD...STILL CONCERNED ABOUT THAT NORTHWEST CORNER.
HOWEVER...CURRENT GRIDS AND ZONES DO INDICATE ICE AND SLEET ACCUM
POTENTIAL...BUT IT SHOULD REMAIN BELOW THE WARNING CRITERIA
THROUGH 6 AM. THE WSW IS STILL SET TO TAKE EFFECT AT 6 AM TO THE
SOUTH OF STEWART...MONTGOMERY AND ROBERTSON COUNTIES.
&&
.AVIATION...
18Z TAF DISCUSSION.
BNA/CKV/CSV...MOISTURE CONTINUES TO ADVECT NE`WD INTO MIDDLE
TENNESSEE AS A SURFACE LOW TRACKS FROM THE GULF COAST TOWARD THE
TENNESSEE VALLEY. HRRR SHOWS RAIN MOVING INTO MIDDLE TENNESSEE
THIS AFTERNOON, REACHING BNA & CKV AROUND 23Z, THEN THE PLATEAU
DURING THE EVENING. AS THE LOW CONTINUES TO MOVE TOWARD THE E/NE,
WINDS WILL TURN MORE NE`WD WITH FALLING TEMPERATURES AND WINTRY
PRECIPITATION DEVELOPING FROM WEST TO EAST OVERNIGHT AND TOMORROW
MORNING. LOOK FOR IFR CIGS THE NEXT 24 HRS ACROSS THE MID STATE
WITH WINDS INCREASING DRAMATICALLY AS THE SFC LOW EDGES CLOSER TO
MIDDLE TENNESSEE.
&&
.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE 36 37 25 32 15 / 100 100 80 20 0
CLARKSVILLE 30 32 23 31 13 / 90 100 60 20 0
CROSSVILLE 35 37 23 29 12 / 100 100 80 60 10
COLUMBIA 36 39 24 32 16 / 100 100 60 20 0
LAWRENCEBURG 36 41 25 33 18 / 100 100 80 20 0
WAVERLY 32 33 22 32 14 / 100 100 60 10 0
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL NOON CST SATURDAY FOR CLAY-FENTRESS-
JACKSON-OVERTON-PICKETT.
WINTER WEATHER ADVISORY FROM 6 AM FRIDAY TO 6 AM CST SATURDAY
FOR BEDFORD-COFFEE-GILES-LAWRENCE-MARSHALL-WAYNE.
WINTER STORM WARNING FROM 6 AM FRIDAY TO NOON CST SATURDAY FOR
CUMBERLAND-GRUNDY-PUTNAM-VAN BUREN-WARREN-WHITE.
WINTER STORM WARNING FROM 6 AM FRIDAY TO 6 AM CST SATURDAY FOR
CANNON-CHEATHAM-DAVIDSON-DE KALB-DICKSON-HICKMAN-HOUSTON-
HUMPHREYS-LEWIS-MAURY-PERRY-RUTHERFORD-SMITH-WILLIAMSON-WILSON.
WINTER STORM WARNING UNTIL 6 AM CST SATURDAY FOR MACON-
MONTGOMERY-ROBERTSON-STEWART-SUMNER-TROUSDALE.
&&
$$
SHORT TERM/AVIATION........01/BOYD
LONG TERM..................21
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1125 PM CST THU JAN 21 2016
.AVIATION...
WINDS CONTINUE TO BE GUSTY AT ALL TAF SITES WITH COLD AIR
ADVECTION CONTINUING AT SURFACE AND ALOFT...AND STRONG PRESSURE
GRADIENT BETWEEN DEEPENING LOW TO THE EAST...AND RIDGE OF HIGH
PRESSURE TO THE WEST. BAND OF LOW CLOUD CONTINUES TO BE SEEN ON
SATELLITE IMAGERY OVER EASTERN TAF SITES INCLUDING UTS...CXO AND
IAH WITH LBX AND SGR MAINLY CLEAR. RH FIELDS IN NAM AND RAP
SUGGEST THE WESTERN EDGE OF THE LOW CLOUD DECK COULD SHIFT
SLIGHTLY BACK WEST OVERNIGHT...SO SKY CONDITION A LITTLE TRICKY AT
AIRPORTS FOR THE OVERNIGHT PERIOD. HAVE BASICALLY GONE MAINLY MVFR
BKN TO OVC AT UTS...CXO AND IAH WITH MAINLY VFR SCATTERED TO SKC
CONDITIONS AT SGR...LBX AND CLL. IAH AND HOU ARE THE TRICKIEST AS
THEY ARE NEAR THE EDGE OF CLOUDY AND MOSTLY CLEAR CONDITIONS.
WINDS WILL REMAIN STRONG AND GUSTY THROUGH THE DAY FRIDAY...THEN
TAPER OFF FRIDAY EVENING AS HIGH PRES BUILDS IN. 46
&&
.PREV DISCUSSION... /ISSUED 913 PM CST THU JAN 21 2016/
DISCUSSION...
STRONG UPPER LEVEL TROUGH ON WATER VAPOR IMAGERY WAS LOCATED OVER
THE ARKLATEX TONIGHT. STRONG COLD FRONT HAS PUSHED WELL OFF THE
COAST AND TIGHT PRESSURE GRADIENT WILL KEEP SOME GUSTY WINDS IN
PLACE ALONG THE COAST. 925MB/850MB WIND FIELDS SEEM TO INCREASE
OVERNIGHT AS LOW PRESSURE DEEPENS TO THE EAST. ONLY AREAS THAT
SEEM TO BE MEETING WIND ADVISORY CRITERIA ARE ALONG THE COAST AND
THROUGH HOUSTON. HOUSTON HOU HAD A WIND GUST OF 38 KNOTS AT
QUARTER TO THE HOUR. WITH COLD AIR ADVECTION AND WINDY
CONDITIONS...WIND CHILLS FOR FRIDAY MORNING WILL BE IN THE 20S FOR
MOST AREAS. MAIN UPDATES TO THE FORECAST WERE TO UPDATE GRIDS FOR
LATEST WIND/TEMP/TD/POP/WX/SKY TRENDS. ALSO UPDATED WIND ADVISORY
FOR THE COASTAL AREAS.
39
PREV DISCUSSION... /ISSUED 529 PM CST THU JAN 21 2016/
AVIATION...
FRONT HAS NOW PUSHED THROUGH WILL GUSTY NW WINDS AT ALL SITES.
WITH STRONG COLD AIR ADVECTION WILL LIKELY SEE GUSTS CONTINUE
TONIGHT WITH STRONGEST WINDS AT GLS DOWNWIND OF THE WATER. SOME
QUESTION ABOUT LOW CLOUDS AS BOTH NAM AND RAP MODELS SHOWING 95
PERCENT RH AT 925 MB...DUE TO A WRAP AROUND LOWER DECK NOW SEEN IN
SATELLITE UPSTREAM. MORE CONFIDENT OF CLEARING EARLY TONIGHT AT
CLL AND LESS OF AN INFLUENCE AT LBX...BUT COULD SEE SEVERAL HOURS
OF 2500 TO 3500 FOOT DECK ELSEWHERE. HAVE BASED TAF ON THIS IDEA.
46
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 35 47 30 52 34 / 0 0 0 0 0
HOUSTON (IAH) 38 51 33 53 37 / 0 0 0 0 0
GALVESTON (GLS) 41 50 38 51 47 / 0 0 0 0 0
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...WIND ADVISORY UNTIL 9 AM CST FRIDAY FOR THE FOLLOWING ZONES:
BRAZORIA...CHAMBERS...GALVESTON...HARRIS...JACKSON...
MATAGORDA.
GM...SMALL CRAFT ADVISORY UNTIL 3 PM CST FRIDAY FOR THE FOLLOWING
ZONES: GALVESTON BAY...MATAGORDA BAY.
SMALL CRAFT ADVISORY FROM 9 AM FRIDAY TO MIDNIGHT CST FRIDAY
NIGHT FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE
MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM
FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS
FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH
ISLAND TO FREEPORT OUT 20 NM.
GALE WARNING UNTIL 9 AM CST FRIDAY FOR THE FOLLOWING ZONES:
WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO
60 NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL
OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60
NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...99
AVIATION/MARINE...99
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
435 AM EST FRI JAN 22 2016
.SYNOPSIS...
A DEVELOPING WINTER STORM WILL LIFT NORTHEAST TOWARD THE SOUTHERN
APPALACHIANS TODAY BEFORE REFORMING OVER EASTERN NORTH CAROLINA
BY TONIGHT. THIS SYSTEM SHOULD PASS OFFSHORE SATURDAY FOLLOWED BY
WEAK HIGH PRESSURE SUNDAY INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 245 AM EST FRIDAY...
NOT A LOT OF CHANGE TO THE GOING FORECAST WITH LOW PRESSURE NOW OVER
THE LOWER MISSISSIPPI VALLEY PROGGED TO RIDE UP INTO THE SOUTHERN
APPALACHIANS TODAY BEFORE GIVING WAY TO A DEEPENING COASTAL LOW OVER
EASTERN NC BY TONIGHT. PRECIP ALREADY CROSSING INTO SW VA WILL
QUICKLY SPREAD NORTH/EAST THROUGH THE MORNING AND BECOME HEAVIER
AS RESULTANT DEEP SE FLOW KICKS IN ALOFT AHEAD OF THE INITIAL
WAVE. MODELS REMAIN VERY IMPRESSIVE WITH SNOWFALL DURING THE DAY
WITH JUST ABOUT A PERFECT SETUP WITH STRONG UVV WITHIN THE
DENDRITIC ZONE AND CSI BANDING IF THEY ARE CORRECT. SOME GUIDANCE
ESPCLY THE GFS SHOWING SNOWFALL OF BETTER THAN 4-6 INCHES IN 6
HOURS THROUGH 00Z THIS EVENING SO APPEARS A LOT OF THE HEAVIER
SNOWFALL WILL OCCUR DURING THE DAY. THUS BOOSTED SNOWFALL AMOUNTS
ON THE FRONT END TODAY WITH A GOOD 10 INCHES TO A FOOT OR MORE
POSSIBLE JUST THROUGH SUNSET. HOWEVER THE LATEST CMC AND SOME
LOCAL SOLUTIONS A BIT FASTER WITH THE DRY SLOT THIS
AFTERNOON...ESPCLY THE LATEST HRRR WHICH REALLY CUTS BACK ON
AMOUNTS AFTER MIDDAY. THEREFORE SOMETHING TO WATCH ESPCLY GIVEN
SUCH STRONG LIFT THIS MORNING...AND POTENTIAL FOR THE UPPER JET
NOW BACK TO THE SW TO CORE OUT THE DEEPER MOISTURE RESULTING IN
LESS HEAVY SNOW LATER ON AS A PERIOD OF WEAK SUBSIDENCE ALOFT
SHIFTS NE. SLIGHTLY BETTER WARM NOSE ALSO SHOWING UP OVER THE FAR
SOUTH ESPCLY OFF THE NAM...MAINLY LATE IN THE WAKE OF THE BETTER
DYNAMIC COOLING SO INCLUDED A LITTLE MORE SLEET NW NC INTO
SOUTHSIDE VA. EVEN SOME FZRA POSSIBLE MAINLY FAR SE WHEN THE
TRANSITION FROM THE INLAND WAVE TO THE COASTAL TAKES SHAPE AS SEEN
WITH A SIMILAR SETUP IN THE PAST. EXPECT TEMPS TO FALL ONCE THE
PRECIP STARTS GIVEN DRY AIR WHICH MAY DELAY THE ONSET A BIT
FARTHER NORTH. OTRW LOOKING AT MAINLY 20S FOR HIGHS WITH SOME
READINGS SPILLING BACK INTO THE TEENS THIS MORNING.
AXIS OF DEEPER MOISTURE PROGGED TO LIFT OUT TO THE NORTH AND EAST
OVERNIGHT WITH MOST SOLUTIONS SHOWING A PRONOUNCED DRY SLOT OVER THE
SOUTH/WEST UNDER THE PASSAGE OF THE UPPER LOW. THIS SUPPORTS SOME
DOWNTURN IN SNOWFALL OUTSIDE OF THE FAR EASTERN/NORTHERN ZONES THIS
EVENING WITH MOSTLY BANDS OF LIGHT/MODERATE SNOW LIKELY PERSISTING
ELSEWHERE. HOWEVER QUITE A BIT LESS SOUTHERN HALF WHERE STILL MAY SEE A
MIX EARLY ON. THUS TRIMMED BACK POPS A LITTLE LATE TONIGHT BUT OVERALL
STILL A FEW ADDED INCHES WEST TO SEVERAL OUT EAST. WITH THE COASTAL LOW
DEEPENING AND PASSING JUST OFFSHORE LATE...EXPECT WINDS TO PICK UP
ESPCLY EAST OF THE BLUE RIDGE WHERE LOTS OF BLOWING/DRIFTING SNOW
LIKELY. APPEARS WINDS WILL STAY BELOW BLIZZARD CRITERIA BUT MAY NEED TO
CONSIDER FOR LATER TONIGHT OVER THE FAR NORTH/NE. AS THE FLOW TURNS
MORE NE WILL SEE TEMPS SLOWLY RISE IN THE 20S LATER TONIGHT AS SNOW
TURNS A BIT WETTER WITH THE INFLUX OF ATLANTIC MOISTURE.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 350 AM EST FRIDAY...
LOOKING TO SATURDAY MORNING...THE CENTER OF THE UPPER LEVEL LOW WILL
BE OVER CENTRAL NORTH CAROLINA...WHILE THE SURFACE REFLECTION OF THE
SYSTEM WILL BE LOCATED JUST EAST OF THE MOUTH OF CHESAPEAKE BAY...
RESULTING IN NORTHERLY WINDS ACROSS OUR AREA. WEATHER FORECAST
MODELS ARE HINTING THAT THE HEAVIEST PRECIPITATION BANDS WILL HAVE
EXITED OUR AREA BEFORE DAWN AS DRIER AIR WORKS INTO THE CENTRAL
APPALACHIANS...AND THAT SNOWFALL WILL TRANSITION FROM WIDESPREAD
LIGHT TO OCCASIONALLY MODERATE ACTIVITY AROUND DAWN...TO MORE OF A
SCATTERED UPSLOPE SNOW SHOWER VARIETY HEADING INTO THE EVENING.
BELIEVE THE HIGHEST SNOWFALL TOTALS FOR OUR AREA ON SATURDAY WILL
OCCUR ALONG THE INTERSTATE 64 CORRIDOR... WHERE AN ADDITIONAL 3 TO 5
INCHES ARE POSSIBLE...MAINLY THROUGH EARLY AFTERNOON. SNOWFALL
AMOUNTS WILL TAPER DOWN TO LESS THAN AN ADDITIONAL INCH OF NEW SNOW
ACROSS PORTIONS OF THE PIEDMONT IN NORTH CAROLINA. BY SATURDAY
EVENING...THE LOW PRESSURE SYSTEM WILL HAVE MOVED FAR ENOUGH AWAY
THAT THE ONLY REMAINING SNOWFALL WILL BE RAPIDLY DIMINISHING UPSLOPE
SNOW SHOWERS ALONG THE WESTERN RIDGES...WITH MINIMAL NEW
ACCUMULATION.
IN ADDITION TO NEW SNOWFALL ACCUMULATIONS...WILL ALSO BE CONCERNED
WITH GUSTY WINDS AS THE LOW PRESSURE SYSTEM DEEPENS THROUGH THE
DAY...CAUSING THE PRESSURE GRADIENT ACROSS OUR AREA TO TIGHTEN.
BELIEVE 20 TO 30 MPH GUSTS WILL BE COMMON THROUGH THE DAY...WITH 40+
MPH GUSTS POSSIBLE ACROSS THE HIGHER RIDGES. THESE GUSTY WINDS WILL
LIKELY RESULT IN WIDESPREAD BLOWING SNOW...WHICH MAY LEAD TO
LOCALIZED WHITEOUT CONDITIONS REGARDLESS OF WHAT IS FALLING FROM THE
SKY. WINDS WILL REMAIN GUSTY THROUGH SATURDAY NIGHT...BEFORE
DIMINISHING ON SUNDAY AS HIGH PRESSURE SETTLES ACROSS THE AREA FROM
THE WEST.
WITH THE DEPARTURE OF THE UPPER LEVEL LOW SATURDAY NIGHT...RIDGING
ALOFT WILL PUSH IN FROM THE WEST ON SUNDAY. DOWNSLOPE NORTHWESTERLY
WINDS...COMBINED WITH ABUNDANT SUNSHINE...WILL MAKE FOR WARMER
AFTERNOON TEMPERATURES AS HIGHS RANGE FROM THE UPPER 20S/LOW 30S
ACROSS SOUTHEAST WEST VIRGINIA...TO THE MID/UPPER 30S OVER THE
SOUTHSIDE. CLEAR SKIES WILL PERSIST INTO SUNDAY NIGHT...WHERE STRONG
RADIATIONAL COOLING DUE TO LIGHT WINDS AND ABUNDANT SNOW COVER WILL
CAUSE THE LOWER ELEVATIONS TO FALL INTO THE TEENS AND THE POSITIVE
SINGLE DIGITS...WHILE WINDS SHIFT SOUTHWESTERLY ALOFT...ALLOWING
WARMER AIR TO FILTER IN TO KEEP THE RIDGETOPS IN THE 20S.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 400 AM EST FRIDAY...
HIGH PRESSURE WILL PASS EAST OF THE REGION ON MONDAY WITH GENERALLY
FAIR WEATHER AND WARMER TEMPERATURES EXPECTED. OUR NEXT CHANCE OF
PRECIPITATION ARRIVES ON TUESDAY AS A LOW PRESSURE SYSTEM MOVES
THROUGH THE GREAT LAKES REGION AND PUSHES A FRONT INTO THE REGION
FROM THE WEST. UPSLOPE SNOW SHOWERS WILL THEN LINGER WEST OF THE
BLUE RIDGE AS SOMEWHAT COLDER AIR ARRIVES FOR THE MIDDLE OF NEXT
WEEK.
&&
.AVIATION /10Z FRIDAY THROUGH TUESDAY/...
AS OF 1145 PM EST THURSDAY...
...VERY POOR AVIATION CONDITIONS EXPECTED 12Z FRI THROUGH END OF
TAF VALID PERIOD...
VFR CONDITIONS WILL PREVAIL ACROSS THE AREA THROUGH APPROXIMATELY
09Z/04AM FRIDAY IN ADVANCE OF AN APPROACHING WINTER STORM. SNOW
WILL OVERSPREAD THE REGION FROM SOUTHWEST TO NORTHEAST FROM LATE
TONIGHT THROUGH THE DAY FRIDAY. AT THE ONSET...SOME SLEET WILL BE
IN THE MIX ACROSS AN AREA ROUGHLY ALONG AND SOUTHWEST OF A KMKW-
KBLF LINE FOR ABOUT A THREE OR FOUR HOUR WINDOW. CEILINGS AND
VISIBILITIES WILL DECREASE INTO IFR RANGE FOR MOST OF THE AREA
WITHIN FOUR HOURS OF THE ONSET OF THE PRECIPITATION...WITH IFR TO
LIFR CIGS/VSBYS EXPECTED BY AFTERNOON IN MODERATE TO HEAVY SNOW
AND FOG. SOME DECREASE IN PRECIPITATION MAY OCCUR LATE IN THE DAY
AS THE FIRST WAVE MOVES OFF TO THE NORTHEAST OF THE REGION. LIFR
CEILINGS WILL BE POSSIBLE LATE IN THE DAY THROUGH THE EVENING IN
SNOW AND FOG. WINDS WILL TREND NORTHEAST TO EAST DURING THE 24
HOUR TIME FRAME...WITH SPEEDS INCREASING INTO THE 5 TO 10 KT RANGE
AFTER 18Z/2PM FRIDAY. MAY NEED TO CONSIDER ADDING GUSTS AS WE MOVE
LATER IN THE NIGHT FRIDAY.
MEDIUM TO HIGH CONFIDENCE IN CIGS AND VSBYS THROUGH THE TAF VALID
PERIOD. MEDIUM TO HIGH CONFIDENCE IN WIND DIR/SPEED THROUGH THE
TAF VALID PERIOD.
EXTENDED DISCUSSION...
WINTER STORM CONTINUES FRIDAY NIGHT INTO SATURDAY WITH WIDESPREAD
SUB VFR CONDITIONS AND SIGNIFICANT SNOWFALL. THIS SYSTEM IS LIKELY
TO RESULT IN LITTLE TO NO AIR TRAVEL IN OUR REGION FRIDAY-
SATURDAY WITH AIRPORTS CLOSED. BY SUNDAY WE ARE GOING TO BE UNDER
INCREASING HIGH PRESSURE WITH VFR LIKELY INTO MONDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WINTER STORM WARNING UNTIL 6 AM EST SUNDAY FOR VAZ007-009>020-
022>024-032>035-043>047-058-059.
NC...WINTER STORM WARNING UNTIL 6 AM EST SUNDAY FOR NCZ001>006-
018>020.
WV...WINTER STORM WARNING UNTIL 6 AM EST SUNDAY FOR WVZ042>044-507-
508.
&&
$$
SYNOPSIS...JH/KK
NEAR TERM...JH
SHORT TERM...NF
LONG TERM...NF
AVIATION...DS/JH/KK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
242 AM CST FRI JAN 22 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 242 AM CST FRI JAN 22 2016
MAIN FORECAST CONCERNS FOR TODAY ARE ON CLOUD COVER AND THE
POTENTIAL FOR A FEW FLURRIES. OTHERWISE...FOCUS TURNS TO SNOW
CHANCES EARLY NEXT WEEK.
LATEST WATER VAPOR SHOWED A TROUGH PUSHING SOUTHEAST ACROSS THE
UPPER MISSISSIPPI RIVER VALLEY. SOME VERY LIGHT SNOW/FLURRIES
WERE FALLING ALONG AND WEST OF THE MISSISSIPPI RIVER. ANOTHER
DUSTING TO AROUND 0.2 INCHES OF SNOWFALL IS POSSIBLE BEFORE THE
SNOW TAPERS OFF AND ENDS. THERE ARE A FEW REPORTS OF FLURRIES
UPSTREAM ACROSS PORTIONS OF EAST CENTRAL MINNESOTA INTO NORTHWEST
WISCONSIN. THE BIGGER QUESTION FOR TODAY IS WHETHER WE WILL SEE
ANY CLEARING AS HIGH PRESSURE BUILDS IN. LOOKING AT THE LATEST
GOES13 IMAGER LOW CLOUD AND FOG PRODUCT...SEEING SOME BREAKS IN
THE STRATUS ACROSS PORTIONS OF WEST CENTRAL INTO NORTHWEST
MINNESOTA SO THERE IS HOPE FOR SOME BREAKS IN THE CLOUDS LATER
TODAY. WITH A FAIRLY STOUT SUBSIDENCE INVERSION IN PLACE...PLAN ON
MOSTLY CLOUDY SKIES TODAY WITH A FEW BREAKS POSSIBLE DURING THE
AFTERNOON HOURS. PLAN ON HIGHS TODAY RANGING FROM THE UPPER TEENS
TO AROUND 20 ACROSS SOUTHEAST MINNESOTA AND NORTHEAST IOWA TO THE
MID TO UPPER 20S ACROSS WESTERN INTO CENTRAL WISCONSIN. HIGH
PRESSURE WILL DOMINATE THE WEATHER PATTERN TONIGHT INTO SATURDAY
WITH DRY AND QUIET WEATHER EXPECTED.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 242 AM CST FRI JAN 22 2016
HIGH PRESSURE WILL REMAIN IN CONTROL ON SUNDAY WITH PARTLY TO MOSTLY
CLOUDY SKIES EXPECTED. A WEAK SHORTWAVE WILL MOVE THROUGH THE RIDGE
BUT THE ONLY IMPACT FROM THE WAVE WILL BE A SLIGHT INCREASE IN MID
LEVEL TO HIGH CLOUD COVER. LOOK FOR HIGHS ON SATURDAY TO RANGE FROM
THE LOWER TO MIDDLE 20S. THE SURFACE RIDGE SLIDES EAST OF THE AREA
ON SATURDAY NIGHT THROUGH SUNDAY AS A TROUGH PUSHES INTO THE CENTRAL
PLAINS. SOUTH/SOUTHWEST WINDS WILL INCREASE ACROSS THE AREA ON THE
BACK SIDE OF THE HIGH...USHERING IN ABOVE NORMALS HIGH TEMPERATURES
FOR SUNDAY. LOOK FOR HIGHS ON SUNDAY TO CLIMB INTO THE UPPER 20S TO
LOWER 30S.
FORECAST MODELS ARE IN GOOD AGREEMENT LATE SUNDAY NIGHT THROUGH
MONDAY BRINGING A TROUGH THROUGH THE UPPER MISSISSIPPI RIVER
VALLEY. AT THIS TIME...SNOW IS THE EXPECTED PRECIPITATION TYPE
ACROSS THE LOCAL AREA WITH LIGHT ACCUMULATIONS POSSIBLE. CERTAINLY
A SYSTEM TO KEEP AN EYE ON AS WE HEAD THROUGH THE WEEKEND...AS
THERE COULD BE SOME TRAVEL IMPACTS FROM THE LIGHT SNOW ON MONDAY.
THE TROUGH THEN LOOKS TO EXIT THE REGION LATE MONDAY NIGHT INTO
TUESDAY WITH HIGH PRESSURE BUILDING IN. THE NEXT SYSTEM TO WATCH
IS A FAST MOVING SHORTWAVE THAT DIVES INTO THE REGION FROM THE
NORTHWEST LATE WEDNESDAY INTO WEDNESDAY NIGHT WITH ADDITIONAL
LIGHT SNOW CHANCES. NORTHWEST FLOW WITH THEN BE THE RULE TO END
THE WEEK ALONG WITH ADDITIONAL LOW CHANCES FOR LIGHT SNOW.
TEMPERATURES LOOK TO REMAIN AT OR SLIGHTLY ABOVE SEASONAL
VALUES...WITH HIGHS IN THE 20S TO AROUND 30 AND LOWS MAINLY IN THE
TEENS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1134 PM CST THU JAN 21 2016
THE AREA OF LIGHT SNOW HAS MOVED INTO THE KRST AREA WITH IFR/MVFR
CONDITIONS. THE LAST FEW RUNS OF THE HRRR SEEM TO HAVE A GOOD
HANDLE ON THIS SNOW AND QUICKLY DROPS IT TO THE SOUTH WITH IT
ENDING IN KRST BY 09Z OR SO. IT IS APPEARING MORE LIKELY THAT THE
SNOW WILL NOT MAKE IT TO KLSE AND HAVE DROPPED BACK TO JUST A FEW
HOURS OF SOME FLURRIES WITHOUT A VISIBILITY REDUCTION. EXPECTING
THE CEILINGS TO REMAIN MVFR INTO FRIDAY AFTERNOON AND THEN THE
QUESTION BECOMES IF THE CLOUDS WILL SCATTER OUT AT ALL. THE 22.00Z
NAM CONTINUES TO KEEPS THE LOW LEVEL MOISTURE TRAPPED UNDERNEATH
THE INVERSION AND HOLDS THE CLOUDS THROUGH THE PERIOD.
HOWEVER...LOOKING AT SATELLITE...MORE OPENINGS ARE APPEARING OVER
SOUTHERN CANADA AND THE 21.21Z SREF BUFKIT SOUNDINGS SUGGEST THE
CLOUDS MAY SCATTER OUT LATE FRIDAY AFTERNOON SO HAVE TRENDED
TOWARD THIS OUTCOME.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM...WETENKAMP
AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1134 PM CST THU JAN 21 2016
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 206 PM CST THU JAN 21 2016
MAIN FOCUS THROUGH THE PERIOD REMAINS THIS EVENING AND FIRST HALF OF
TONIGHT REGARDING SNOW POTENTIAL...WHILE ALL EYES OF COURSE FOCUS ON
WHAT CONTINUES TO SHAPE UP TO BE AN IMPRESSIVE MID ATLANTIC WINTER
STORM. EARLY AFTERNOON ANALYSIS SHOWS THE PLAYERS IN THE GAME...WITH
A PAIR OF SHORTWAVES WORKING THROUGH THE SOUTHERN/CENTRAL PLAINS AND
A RATHER ROBUST NORTHERN STREAM WAVE QUICKLY DIVING THROUGH THE
WESTERN DAKOTAS ON THE HEELS OF A 110+ KNOT JET PLOWING SOUTH OUT OF
SASKATCHEWAN. IT IS THESE FEATURES THAT WILL LINK UP TO CARVE OUT
QUITE THE CLOSED UPPER LOW OVER THE MID SOUTH STATES BY
SATURDAY...BUT OF INTEREST FOR US REMAINS THAT INCOMING NORTHERN
STREAM WAVE LATER TODAY INTO THE FIRST PART OF TONIGHT. OVERALL
FORCING AND MOISTURE REMAINS FAIRLY NEBULOUS...BUT A QUICK SHOT OF
DEEPER LAYER 290-305K UPGLIDE SHOULD HELP TO AT LEAST SUSTAIN
ONGOING LIGHT PRECIP CURRENTLY ONGOING ACROSS EASTERN SOUTH DAKOTA
AND WESTERN MINNESOTA.
HOWEVER....WE STILL HAVE QUITE A BIT OF SATURATION WORK TO
ACCOMPLISH WITH ONLY THE SUB-900MB LAYER ALREADY SATURATED (THOUGH
WITH SOME PESKY FLURRIES/LIGHT SNOW FALLING FROM SAID CLOUD DECK
WITH CLOUD TOP TEMPS AROUND -11C AND SHALLOW LIFT). SYSTEM LOOKS A
GOOD DEAL LIKE THE ONE FROM TUESDAY EVENING...WITH MUCH OF THE
ASCENT GOING INTO TOP DOWN SATURATION...THOUGH DO STILL BELIEVE WE
WILL PICK UP SOME LIGHT MEASURABLE SNOW...ESPECIALLY WEST OF THE
MISSISSIPPI. NOT LOOKING LIKE A HUGE DEAL WITH RATHER LOW RATIOS
GIVEN THE "WARM" AIRMASS... BUT A FRESH HALF TO PERHAPS ONE INCH
LOOKS DOABLE...WITH AMOUNTS LIKELY TAPERING QUICKLY TO THE EAST
GIVEN ABOVE-MENTIONED DRY AIR ISSUES.
FORCING (SUCH AS IT IS) REALLY SHUTS DOWN FAST AFTER 06Z...LEAVING
BUILDING LOW/MID LEVEL RIDGING INTO FRIDAY AND SATURDAY. LOTS OF
QUESTIONS ABOUT HOW MUCH LOW CLOUD COVER WILL STICK AROUND. GUIDANCE
REMAINS ROBUST ON CLEARING TRENDS INTO FRIDAY BUT DO HAVE SOME
CONCERNS GIVEN HOW WIDESPREAD LOWER STRATUS IS AT THE MOMENT...NOT
TO MENTION THAT WE WILL BE AGAIN BE BUILDING A DECENT INVERSION WITH
THE RIDGE ARRIVAL. THERE ARE A FEW BREAKS SHOWING UP INTO WESTERN
ONTARIO...SO IT`S NOT OUT OF THE QUESTION WE MAY SEE AT LEAST A
BRIEF WINDOW OF SOME CLEARING...BUT WITH LIGHT FLOW INTO FRIDAY
NIGHT/SATURDAY AS THE RIDGE AXIS BUILDS SQUARELY OVERHEAD...WOULD
TEND TO BELIEVE WE WILL SEE WIDESPREAD STRATUS RE-APPEAR. THAT OF
COURSE WILL MESS WITH BOTH HIGH AND LOW TEMPS...AND RIGHT OFF THE
BAT...SUSPECT WE ARE TOO COOL BOTH TONIGHT AND AGAIN FRIDAY NIGHT
(MAYBE SATURDAY NIGHT TOO). STILL LOOKING MILD ON SUNDAY AS WE BREAK
INTO THE "WARM SECTOR" AHEAD OF A NORTHERN STREAM WAVE SKIRTING THE
U.S./CANADIAN BORDER...THOUGH AGAIN SUSPECT WE WILL BE STUCK IN THE
LOW CLOUDS. FORECAST SOUNDINGS FROM THE NAM DO SUGGEST THERE COULD
BE A FEW SPITS OF SOME DRIZZLE ON SUNDAY AS WELL...THOUGH THE SETUP
DOESN`T LOOK OVERLY FAVORABLE WITH STRONGER SOUTHERLY FLOW AND
PRETTY MUCH NO LIFT THROUGH THE SATURATED LAYER.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 206 PM CST THU JAN 21 2016
LOOKING A LITTLE MORE ACTIVE TO START THE WORK WEEK WITH A RETURN TO
OUR FAMILIAR FASTER FLOW REGIME...AND WESTERN TROUGHING AT TIMES
EJECTING OUT ONTO THE PLAINS AND THEN LIFTING IN OUR DIRECTION.
GUIDANCE TRENDS THE PAST 24 HOURS CONTINUE TO SUPPORT OUR NEXT WAVE
ARRIVING LATE SUNDAY NIGHT INTO MONDAY WITH CHANCES FOR ACCUMULATING
SNOW...THOUGH OF COURSE THE EXACT DETAILS REMAIN A LITTLE MURKY
(WITH THE 21.06Z GFS PRETTY MUCH SUGGESTING A CWA SPLIT OF THE
BETTER PRECIP). STILL ANOTHER DAY OR TWO TO FIGURE OUT THE BIGGER
DETAILS...BUT FOR THE MOMENT...THIS DOESN`T LOOK LIKE A HUGE EVENT
BUT COULD PRODUCE A FEW INCHES IN SPOTS. THEREAFTER...PRETTY QUIET
MONDAY NIGHT THROUGH WEDNESDAY AS LOW LEVEL RIDGING WORKS FROM THE
PLAINS STATES THROUGH MUCH OF THE MISSISSIPPI VALLEY WITH
TIME...THOUGH WE MAY AGAIN DEAL WITH PESKY CLOUD COVER FOR PART OR
ALL OF THE TIME WITH HINTS OF MOISTURE TUCKED UP UNDER ANOTHER
SHALLOW INVERSION. COULD SEE SOME SMALLER CHANCES FOR SNOW MAKE A
RETURN TOWARD THURSDAY OR JUST BEYOND WITH ANOTHER UPPER WAVE
ROLLING DOWN THROUGH NORTHWEST FLOW ALOFT...BUT HONESTLY GIVEN JUST
HOW FAST/CHAOTIC THE PACIFIC FLOW HAS BEEN AND REMAINS...FULLY
EXPECT TIMING/PLACEMENT CHANCES TO SHORTWAVES LIKE THIS ONE OVER THE
COMING DAYS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1134 PM CST THU JAN 21 2016
THE AREA OF LIGHT SNOW HAS MOVED INTO THE KRST AREA WITH IFR/MVFR
CONDITIONS. THE LAST FEW RUNS OF THE HRRR SEEM TO HAVE A GOOD
HANDLE ON THIS SNOW AND QUICKLY DROPS IT TO THE SOUTH WITH IT
ENDING IN KRST BY 09Z OR SO. IT IS APPEARING MORE LIKELY THAT THE
SNOW WILL NOT MAKE IT TO KLSE AND HAVE DROPPED BACK TO JUST A FEW
HOURS OF SOME FLURRIES WITHOUT A VISIBILITY REDUCTION. EXPECTING
THE CEILINGS TO REMAIN MVFR INTO FRIDAY AFTERNOON AND THEN THE
QUESTION BECOMES IF THE CLOUDS WILL SCATTER OUT AT ALL. THE 22.00Z
NAM CONTINUES TO KEEPS THE LOW LEVEL MOISTURE TRAPPED UNDERNEATH
THE INVERSION AND HOLDS THE CLOUDS THROUGH THE PERIOD.
HOWEVER...LOOKING AT SATELLITE...MORE OPENINGS ARE APPEARING OVER
SOUTHERN CANADA AND THE 21.21Z SREF BUFKIT SOUNDINGS SUGGEST THE
CLOUDS MAY SCATTER OUT LATE FRIDAY AFTERNOON SO HAVE TRENDED
TOWARD THIS OUTCOME.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...LAWRENCE
LONG TERM...LAWRENCE
AVIATION...04
EAST CENTRAL FLORIDA FORECAST DISCUSSION
NWS MELBOURNE FL
928 AM EST FRI JAN 22 2016
.DISCUSSION...
...FAST MOVING SQUALL LINE TODAY WITH SLIGHT RISK OF STRONG-
SEVERE STORMS...
...WINDY AND MUCH COLDER SATURDAY WITH A FREEZE THREAT AND LOW
WIND CHILLS EARLY SUNDAY MORNING...
SCATTERED SHOWERS AND FAST MOVING EMBEDDED STORMS PRECEDING MORE
ORGANIZED CONVECTION ACROSS THE GULF COAST WAS OCCURRING AT THIS HOUR.
DEVELOPMENT LOCALLY HAS BEEN HINDERED BY A CONSIDERABLE CANOPY OF
CLOUD COVER...HOWEVER FORCED UPWARD MOTION ASSOCIATED WITH THE
APPROACH OF THE GULF LOW AND A MORE FAVORABLE JET FORCED ASCENT PROFILE
WILL UNFOLD THROUGH LATE MORNING AND INTO THE AFTERNOON LOCALLY.
A BAND OF PREFRONTAL CONVECTION CURRENTLY CLOSING IN ON THE GULF
COAST OF WEST FL IS INDICATED MOVING OVER THE AREA FROM AROUND NOON
INTO MID AFTERNOON AS SHOWN BY HRRR GUIDANCE. THIS BAND...INCLUDING THE
SCATTERED STORMS IN THE MARGINALLY BUOYANT ENVIRONMENT AHEAD WL NEED TO
BE MONITORED. THE FORECAST WILL BE UPDATED MAINLY FOR A FEW
TIME ADJUSTMENTS.
DEEP LAYER SHEAR ALONG WITH SOME LOW LEVEL WIND BACKING THROUGH EARLY
AFTERNOON WL MAINTAIN GOOD LOW LEVEL CONVERGENCE AHEAD OF THE FRONT.
INSTABILITY WILL BE LIMITED WITH ONLY A BRIEF WINDOW OF TIME AVAILABLE
FOR DAYTIME DESTABILIZATION WITH MODEST HEATING AND DEW POINT RECOVERY.
THERE WILL BE ENOUGH INSTABILITY FOR ISOLATED STRONG-SEVERE STORMS. THE
PRIMARY THREAT WILL BE DAMAGING STRAIGHT LINE WIND GUSTS WITH THE
SQUALL LINE...BUT CANNOT RULE OUT AN ISOLATED TORNADO WITHIN BOWING
SEGMENTS OF THE LINE.
PREVIOUS DISCUSSION...
TONIGHT...THE COLD FRONT WILL SWEEP EAST OF
THE STATE BY EARLY EVENING. BREEZY TO WINDY CONDITIONS ARE EXPECTED
BEHIND THE FRONT WITH TIGHT PRESSURE GRADIENT AS DEEPENING LOW MOVES
NORTHEAST ALONG THE CAROLINA COAST. STEEP LOW LEVEL LAPSE RATES IN
THE WAKE OF THE COLD FRONT WILL SUPPORT LOW TOPPED CONVECTION IN THE
GULF...AND WITH A STRONG LOW LEVEL WIND FIELD...THERE IS A SLIGHT
CHANCE FOR THESE SHOWERS TO PUSH WELL INLAND OVERNIGHT. IT WILL TURN
SHARPLY COLDER AROUND SUNSET...BUT THE WEST FLOW OFF THE GULF WILL
LIMIT THE EFFECTS OF STRONG COLD ADVECTION DURING THE OVERNIGHT. LOW
TEMPS WILL DROP INTO THE MID 40S NORTH TO MID 50S FAR SOUTH.
SAT-SUN...THE STRONG LOW PRESSURE CENTER EAST OF NORFOLK VA/VACAPES
LIFTS NORTHEAST OVER THE ATLANTIC THROUGH SUNDAY. A VERY TIGHT
PRESSURE GRADIENT WILL EXIST ACROSS THE AREA SATURDAY IN THE WAKE OF
THE LOW WITH WINDY CONDITIONS EXPECTED ACROSS THE AREA SATURDAY.
CURRENT WIND FORECAST FOR SATURDAY INDICATES THAT A WIND ADVISORY
WILL MOST LIKELY BE NEEDED FOR MUCH OF THE AREA.
HIGH PRESSURE OVER THE LOWER MISSISSIPPI RIVER VALLEY BUILDS ACROSS
THE SOUTHEAST U.S. AND INTO FLORIDA. NORTHWEST TO NORTH WINDS ADVECT
A DRY AND COLDER AIRMASS INTO FLORIDA SATURDAY AND SUNDAY. HIGHS
SATURDAY TO BE IN THE 50S TO LOW 60S. THE 22/00Z GUIDANCE SUGGESTING
A LITTLE MORE COLD AIR ADVECTION SATURDAY NIGHT WITH LOWS IN MOST
AREAS IN THE LOW AND MID 30S EXCEPT FOR THE COAST FORT PIERCE
SOUTH AND MARTIN COUNTY. THE COMBINATION OF THESE COLD
TEMPERATURES AND NORTHWEST WINDS AT 10 TO 15 MPH SHOULD PRODUCE
WIND CHILLS IN THE MID AND UPPER 20S NORTH TO SOUTH EXCEPT THE LOW
30S SAINT LUCIE AND MARTIN COUNTIES.
A SLIGHT WARM UP ON SUNDAY WITH HIGHS RANGING FROM THE MID 50S NORTH
AND WEST OF INTERSTATE 4 TO AROUND 60/LOW 60S OKEECHOBEE...SAINT
LUCIE AND MARTIN COUNTIES. LOWS MONDAY MORNING EXPECTED TO RANGE
FROM THE UPPER 30S INTERIOR AND WEST OF INTERSTATE 95 TO THE LOW 40S
AT THE COAST SOUTH BREVARD TO MARTIN COUNTY.
MON-FRI...UPPER LEVEL RIDGE OVER THE SOUTHEAST MONDAY SHIFTS INTO
THE WESTERN ATLANTIC TUESDAY AND BEYOND AS A TROUGH OVER THE ROCKIES
DIGS SOUTH AS IT MOVES EASTWARD ACROSS THE SOUTHERN PLAINS AND INTO
THE SOUTHEAST U.S. BY THURSDAY. TROUGH AXIS CLEARS FLORIDA PENINSULA
FRIDAY. AT THE SURFACE...HIGH PRESSURE OVER THE SOUTHEAST U.S.
SHIFTS INTO THE WESTERN ATLANTIC MONDAY AND TUESDAY. SOUTHEAST FLOW
MONDAY SHIFTS TO THE SOUTH TUESDAY AND THE SOUTHWEST WEDNESDAY AND
THURSDAY AS TROUGHING OVER THE LOWER MISSISSIPPI RIVER VALLEY MOVE
SLOWLY INTO THE SOUTHEAST STATES. MOISTURE VALUES BEGIN A SLOW
RECOVERY MONDAY AND TUESDAY REACHING AN INCH AND A HALF/1.5 INCHES
OR MORE WEDNESDAY AND THURSDAY. IMPULSES/DISTURBANCES IN THE
SOUTHWEST FLOW ALOFT TRIGGER WEAK SURFACE LOWS THAT MOVE NORTHEAST
OVER FLORIDA THROUGH WEDNESDAY. STRONG ENOUGH IMPULSE MOVES THROUGH
THURSDAY TRIGGERING A SURFACE LOW OFF THE SOUTHWEST AND WEST FLORIDA
COAST OVERNIGHT WEDNESDAY. THE LOW MOVES QUICKLY TO THE NORTHEAST
ACROSS THE FLORIDA PENINSULA THURSDAY AND IS EAST OF THE CAROLINAS
FRIDAY NIGHT. WEDNESDAY AND THURSDAY BEST OPPORTUNITY FOR RAIN.
FRONT CLEARS FLORIDA OVERNIGHT THURSDAY AND HIGH PRESSURE BUILDS IN
FROM THE NORTHWEST(SOUTHEAST U.S.) FRIDAY. LOWS IN THE 50S AND LOW
60S THROUGH THURSDAY THEN BACK INTO THE 40S FRIDAY MORNING IN THE
NORTHWEST FLOW BEHIND THE FRONT.
&&
.AVIATION...
IT WILL BE ANOTHER DAY WITH FAST CHANGING CONDITIONS. EARLY
MORNING VFR WILL GIVE WAY TO A BRIEF PERIOD WITH MVFR-IFR AS A
FAST MOVING SQUALL LINE MOVES THROUGH. EXPECT ISOLATED LIGHTNING
STRIKES AND A CHANCE FOR WIND GUSTS OVER 40 KNOTS WITH THE LINE.
A COLD FRONT WILL MOVE THROUGH DURING THE AFTERNOON AND GUSTY
WESTERLY WINDS TO 25 KNOTS ARE EXPECTED...WHICH MAY OCCUR
INTERMITTENTLY INTO THE OVERNIGHT HOURS.
&&
.MARINE...
TODAY-TONIGHT...INTENSIFYING LOW PRESSURE OVER THE DEEP SOUTH TO
CAROLINA COAST WILL SWING A STRONG COLD FRONT EAST OF THE COASTAL
WATERS THIS EVENING. INCREASING SOUTHERLY WINDS TODAY HAS PROMPTED
A SMALL CRAFT ADVISORY. ADDITIONALLY...A FAST MOVING SQUALL LINE
WILL MOVE ACROSS THE WATERS THIS AFTERNOON...SO SMALL CRAFT
OPERATION IS DEFINITELY NOT ADVISED TODAY.
BEHIND THE FRONT...WE EXPECT FREQUENT GUSTS TO GALE FORCE IN THE
OPEN ATLANTIC...SO HAVE UPGRADED TO A GALE WARNING FOR THE
OFFSHORE WATERS STARTING THIS EVENING.
SAT-SUN...VERY HAZARDOUS BOATING CONDITIONS THROUGH SAT NIGHT WITH A
TIGHT PRESSURE GRADIENT IN THE WAKE OF THE LOW...PRODUCING WESTERLY
WINDS UP TO 25-30 KNOTS OFFSHORE WITH FREQUENT GUSTS TO GALE
FORCE. THIS WILL BUILD SEAS UP TO 9 TO 12 FEET OFFSHORE. A SMALL
CRAFT ADVISORY FOR THE NEARSHORE WATERS EXTENDS THROUGH SAT NIGHT
WITH A GALE WARING OFFSHORE.
BOATING CONDITIONS WILL REMAIN POOR-HAZARDOUS THROUGH SUNDAY
MORNING THEN WIND SPEEDS WILL DROP OFF CONSIDERABLY IN THE
AFTERNOON.
MON-TUE...GREATLY IMPROVED BOATING CONDITIONS ARE FORECAST WITH HIGH
PRESSURE PROVIDING LIGHTER WINDS MON...BUT IT WILL BE VERY CHILLY IN
THE MORNING. WINDS WILL REMAIN ON THE LIGHTER SIDE INTO MON
NIGHT/TUE...BUT MODELS INDICATE AN INCREASING SWELL UP TO 6 FEET
OFFSHORE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 73 45 55 34 / 90 20 10 10
MCO 74 49 58 36 / 90 20 10 10
MLB 76 50 61 34 / 90 20 10 10
VRB 77 53 63 36 / 80 20 10 10
LEE 71 46 56 33 / 90 20 10 0
SFB 73 47 55 35 / 90 20 10 10
ORL 73 48 57 36 / 90 20 10 10
FPR 77 53 64 36 / 80 20 10 10
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY UNTIL 4 AM EST SUNDAY FOR FLAGLER BEACH TO
VOLUSIA-BREVARD COUNTY LINE 0-20 NM-SEBASTIAN INLET TO
JUPITER INLET 0-20 NM-VOLUSIA-BREVARD COUNTY LINE TO
SEBASTIAN INLET 0-20 NM.
SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR FLAGLER
BEACH TO VOLUSIA-BREVARD COUNTY LINE 20-60 NM-SEBASTIAN
INLET TO JUPITER INLET 20-60 NM-VOLUSIA-BREVARD COUNTY LINE
TO SEBASTIAN INLET 20-60 NM.
GALE WARNING FROM 7 PM THIS EVENING TO 4 AM EST SUNDAY FOR
FLAGLER BEACH TO VOLUSIA-BREVARD COUNTY LINE 20-60 NM-
SEBASTIAN INLET TO JUPITER INLET 20-60 NM-VOLUSIA-BREVARD
COUNTY LINE TO SEBASTIAN INLET 20-60 NM.
&&
$$
JP/DKW/WU
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
500 AM CST FRI JAN 22 2016
.SHORT TERM...(Today)
ISSUED AT 329 AM CST FRI JAN 22 2016
The storm system that will affect the East Coast over the next
several days was gathering strength over western Alabama as of 2am.
The precipitation shield associated with the storm was pushing into
extreme southern Illinois with models continuing to suggest the bulk
of the snow will stay just south of Lawrenceville today. Will
continue to hang on to at least slight chance wording in our far
southeast counties to account for any northward shift in the precip
today, however, forecast soundings and time-height cross sections
showing quite a bit of dry air from 925-800 my layer so if the snow
is able to make it to the surface, it will be on the light side with
the more significant accumulating snowfall remaining south.
Further north, a weak shortwave seen on the water vapor loop over
the Great Lakes will shift southeast today with the main forecast
concern with that feature being a large deck of stratus along and
to the north of the trof axis in addition to some scattered flurries.
May see the lower deck gradually work its way south into the
forecast area during the day today but most of the short term models
indicate any light snow or flurries with the upper wave will remain
to our west and north today. Something to keep an eye on in the
short term with both the HRRR and RAP models indicating the north to
northeasterly flow off of Lake Michigan may push some flurries
southwest to parts of north-central Illinois this afternoon. Not
much of a big diurnal shift in temperatures today due to the cloud
cover with most areas in the upper 20s to lower 30s this afternoon.
.LONG TERM...(Tonight through Thursday)
ISSUED AT 329 AM CST FRI JAN 22 2016
Strong low pressure to deepen and move off the NC coast overnight
with its snow mainly along and se of the Ohio river pulling further
away from southeast IL, while clouds begin to decrease from the nw
during overnight. Breezy north winds to continue tonight especially
in eastern IL closer to strong low pressure near the NC coast. Lows
tonight in the upper teens central IL and lower 20s se of I-70.
With Nor`easter off the mid Atlantic and New England coast Saturday
and Saturday night bringing a major winter storm to mid Atlantic
states and southern New England, quiet weather expected for IL this
weekend. Mostly sunny skies Saturday over central and southeast IL
with surface ridge over the MS river valley by sunset Saturday and
as upper level ridge shifts east into IL by Sunday. Highs mostly in
the lower 30s Saturday with NNW winds keeping it cool. Temps modify
Sunday into the mid 30s to around 40F with increasing south winds
on Sunday along with some increase clouds over central IL.
A storm system off the West Coast to bring an upper level trof east
into IL by Monday evening while weak surface low pressure tracks
from the OK panhandle at sunset Sunday into ne IL by sunday Monday.
Still dry Sunday night with light precipitation spreading east over
IL during the day Monday. 00Z models have trended slower with
arrival of this weather system, so think surface temps will be above
freezing by time precipitation starts. Monday looks warm enough to
support mainly light rain with chance of light snow over northern
CWA Monday morning and far NW CWA by Knox and Stark counties Monday
afternoon with little or no accumulations. Above normal highs Monday
in the upper 30s/lower 40s.
A bit cooler air moves in behind a cold front during Monday night as
light rain changes to light snow before diminishing to flurries and
linger into Tue with upper level trof over the Great lakes and into
IL. Any snowfall amounts appear quite light if they occur Monday
night generally less than a half inch. Highs Tue around 30F northern
CWA to near 35F far se IL along and south of highway 50. Weak high
pressure near IL Wed with dry conditions and partly sunny skies with
highs mostly in the lower 30s. 00Z models have trended further nne
with northern stream short wave/clipper system on Thu where brunt of
light snow chances pass ne of central IL with just slight chances
for central and ne CWA. Temps to modify back into mid to upper 30s
Thu and a few degrees milder next Friday in upper 30s/lower 40s.
&&
.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
ISSUED AT 500 AM CST FRI JAN 22 2016
A band of MVFR, with occasional IFR cigs, was edging slowly south
and southwest this morning and will begin to affect our northern
TAF sites after 15z...and then points further south after 18z.
Low pressure well to our south will take the more significant
snowfall well south of our TAF sites today while the gusty
northeast flow draws some lower clouds south into the area during
the day. Bases of the cigs just to our north were in the 1000 to
2000 foot range over the past couple of hours. Initially, think
those will be the bases of the cigs in our area as it moves in
later this morning or early this afternoon, but with a persistent
dry northeast flow, we may see the cig bases come up a bit to
1500-2000 feet. Forecast soundings not offering much hope of any
improvement thru at least this forecast period with at least MVFR
cigs holding into the overnight hours.
Surface winds will be out of the north to northeast at 10 to 15
kts with occasional gusts up to 23 kts, especially along and east
of the I-55 corridor. Look for northerly winds to diminish to
around 10 kts tonight.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Smith
LONG TERM...07
AVIATION...Smith
AREA FORECAST DISCUSSION
NWS WICHITA KS
530 AM CST FRI JAN 22 2016
...UPDATED FOR 12Z AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 340 AM CST FRI JAN 22 2016
D-E-E-P UPPER-DECK TROF UNDERGOING CYCLOGENESIS CONTINUED DIGGING
OVER THE AR/LA BORDER DURING THE NIGHT WITH IT`S ATTENDANT SFC LOW
DEVELOPING OVER THE MS/AL BORDER. THIS IS KEEPING ALL OF CENTRAL &
EASTERN KS IN A "MODERATE" N/NE REGIME. A SOMEWHAT UNORTHODOX DRY
SLOT IS KNIFING ALMOST DUE S ACROSS EASTERN KS THAT`LL TEAM WITH
SNOW FIELD TO ENABLE TEMPERATURES ACROSS NORTHEAST & EAST-CENTRAL
KS TO NOSEDIVE EARLY THIS MORNING THUS SHARPENING THE E-W GRADIENT
EARLY THIS MORNING.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 340 AM CST FRI JAN 22 2016
TODAY & TONIGHT:
THE GREATEST ISSUE IS HOW THE STRATUS WILL BEHAVE. THE LOWER-DECK
CYCLONE...THAT IS SITUATED OVER THE MS/AL BORDER VERY EARLY THIS
MORNING...SHOULD GET FORCED SLOWLY E/NE ACROSS THE AL/TN BORDER
THIS AFTERNOON AS A HIGH-AMPLITUDE RIDGE PUNCHES NE FROM AZ/NM
TOWARD THE NORTHERN PLAINS. THE NAM...RUC & HRRR ALL KEEP A SHARP
900-850MB INVERSION OVER ALL OF THE CWA THRU LATE THIS AFTERNOON.
THE NAM SHARPENS THE INVERSION TONIGHT WHICH WOULD LIKELY KEEP THE
NEIGHBORHOOD STRATIFIED THIS EVENING. AS SUCH WILL HAVE MOST...IF
NOT ALL...OF KICT COUNTRY UNDER A LOW OVERCAST THRU EARLY THIS
EVENING. THIS OF COURSE WOULD HAVE RAMIFICATIONS ON TEMPERATURES.
(ESPECIALLY ALONG THE NE CORRIDOR.) FOR THE MOST PART HAVE
FOLLOWED THE CONSALL & SUPERBLEND SOLUTIONS. WITH THE AFORE-
MENTIONED POSITIVELY-TILTED RIDGE AXIS SHIFTING E SKIES SHOULD
CLEAR W-E TO ENABLE TEMPERATURES TO TUMBLE. DID UNDERCUT GUIDANCE
ALONG NE SECTOR WHERE SNOW FIELD WOULD NO DOUBT ASSIST THE
CLEARING SKIES & WINDS THAT`LL BECOME LIGHT & VARIABLE WITH THE
TEMPERATURE DROP.
THIS WEEKEND:
WARMER WEATHER IS STILL SCHEDULED TO ARRIVE AS THE ABOVE-MENTIONED
MID-UPPER RIDGE DEAMPLIFIES & SPREADS E ACROSS THE CENTRAL THIRD
OF THE CONUS SAT & SAT NIGHT. A DEEP...COMPACT CYCLONE THAT HAS
BEEN APPROACHING THE NORTHERN CA/OR COAST DURING THE NIGHT WILL
QUICKLY TRANSITION INTO AN OPEN WAVE AS IT CROSSES AS IT CROSSES
THIS SECTION OF THE COAST LATE TONIGHT & SAT. IT`LL GRADUALLY
RESTRENGTHEN AS IT CROSSES THE ROCKIES ON SUN THEN ACROSS THE
CENTRAL & SOUTHERN PLAINS SUNDAY NIGHT. THIS WOULD SWEEP A COLD
FRONT SE ACROSS KS SUNDAY NIGHT. SOME POST FRONTAL PRECIPITATION
(LIGHT SNOW) IS POSSIBLE ACROSS CENTRAL KS LATE SUNDAY NIGHT. THE
RAPIDLY PROGRESSIVE PATTERN SHOULD KEEP CHANCES FOR ACCUMULATION
IN CHECK.
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 340 AM CST FRI JAN 22 2016
MON:
AS THE CONTINUALLY STRENGTHENING UPPER-DECK WAVE SURGES E TOWARD
THE MS VALLEY ALL PRECIPITATION SHOULD QUICKLY END. TEMPERATURE
PROFILES DEPICT PRIMARILY LIGHT RAIN FOR SOUTHEAST KS.
MON NIGHT-THU:
A CYCLONE WILL APPROACH HUDSON BAY MON NIGHT & RAPIDLY INTENSIFY
AS IT CROSSES HUDSON BAY TUE & TUE NIGHT. THE CYCLONE WILL KICK A
S-H-A-R-P POSITIVELY-TILTED MID-UPPER LONG-WAVE SE ACROSS THE
GREAT PLAINS TUE NIGHT...HOWEVER IT`S SFC COHORT APPEARS TO KEEP
THE CENTRAL & SOUTHERN PLAINS IN A PREDOMINANTLY NW COMPONENT TO
KEEP TEMPERATURES ON THE MILD SIDE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 527 AM CST FRI JAN 22 2016
CHALLENGING AVIATION FORECAST WITH MVFR/IFR CEILINGS LIKELY AT
MOST SITES THIS MORNING. MOST MODELS HAVE BEEN CLUELESS WITH
BOUNDARY LAYER MOISTURE AND LARGE DRY SLOT THAT SET UP ACROSS
EASTERN KS DURING THE NIGHT. THE ONE MODEL THAT SEEMED TO HAVE A
CLUE WAS THE ARW. IT SUGGESTS SOME DETERIORATION/SATURATING AROUND
DAYBREAK THEN RAPID BURNOFF BETWEEN 15-18 UTC. IT ALSO SUGGESTS
CLOUDS WOULD PROBABLY NOT RETURN TO KCNU. WINDS WILL DIMINISH LATE
AFTERNOON OR NEAR SUNSET AS RIDGE MOVES ACROSS TONIGHT. THINK THERE
WILL BE SOME FOG POTENTIAL TONIGHT IN SOUTHEAST KS...BUT RETURN
FLOW BEFORE DAYBREAK IN THE WEST MAY LIMIT CHANCES. -HOWERTON
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 32 17 43 28 / 0 0 0 0
HUTCHINSON 30 15 41 27 / 0 0 0 0
NEWTON 29 15 39 27 / 0 0 0 0
ELDORADO 31 15 40 28 / 0 0 0 0
WINFIELD-KWLD 33 17 42 29 / 0 0 0 0
RUSSELL 30 17 41 26 / 0 0 0 0
GREAT BEND 31 17 43 27 / 0 0 0 0
SALINA 28 13 34 27 / 0 0 0 0
MCPHERSON 29 14 39 27 / 0 0 0 0
COFFEYVILLE 34 18 40 28 / 0 0 0 0
CHANUTE 31 16 38 27 / 0 0 0 0
IOLA 31 16 37 27 / 0 0 0 0
PARSONS-KPPF 33 17 39 27 / 0 0 0 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS JACKSON KY
942 AM EST FRI JAN 22 2016
.UPDATE...
ISSUED AT 942 AM EST FRI JAN 22 2016
SNOW HAS QUICKLY OVERSPREAD EASTERN KENTUCKY THIS MORNING WITH THE
WARN NOSE ERODED. SOME SPOTS HAVE ALREADY RECEIVED 4 TO 6 INCHES
OF SNOW WITH AT LEAST 1 INCH PER HOUR RATES OCCURRING.
THE BIGGEST UPDATE MADE TO THE GRIDS WAS TO INCREASE THE TOTAL
SNOW IN THE SOUTHWEST COUNTIES...INCLUDING WAYNE AND PULASKI
COUNTIES. MANY OF THE MODELS ARE INDICATING A BULLSEYE OF SNOW
NEAR THIS AREA AND BELIEVE THIS IS DUE TO THE CONVECTION THAT IS
MOVING NORTHWARD FROM TENNESSEE. WE HAVE COORDINATED THIS INCREASE
IN SNOWFALL TOTALS WITH LMK. ALSO MADE ADJUSTMENTS TO ELIMINATE
THE MENTION OF FREEZING RAIN BUT KEPT SOME SLEET IN THE EASTERN
MOST COUNTIES THROUGH MID-DAY. OTHERWISE...EXPECT HEAVY...WET SNOW
TO CONTINUE THROUGH THIS EVENING WITH 1 TO 2 INCH PER HOUR RATES
POSSIBLE. A CHANCE OF SOME ISOLATED THUNDER IS ALSO POSSIBLE WITH
THE CONVECTION MOVING INTO SOUTHERN KENTUCKY.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 454 AM EST FRI JAN 22 2016
STEADY PRECIP IS OVERSPREADING OUR SOUTHERN 1/3 TO 1/2 OF THE
CWA AS OF 3AM. WE/VE HAD MULTIPLE REPORTS OF FREEZING RAIN ACROSS
THE FAR SOUTHERN CWA AS THE PRECIP MOVED INTO THE AREA. THIS IS ON
PAR WITH INFORMATION WE RECEIVED FROM OHX AFTER THEY CONDUCTED A
SPECIAL BALLOON LAUNCH...NOTING THAT THE WARM NOSE WAS MUCH MORE
PRONOUNCED THAN MODELS WERE PICKING UP ON. BY 2AM...WILLIAMSBURG
IN WHITLEY COUNTY HAD ALREADY RECEIVED A TENTH OF AN INCH OF ICE
ACCUMULATION. AS SUCH...THE BIGGEST CHANGE IN THE NEAR TERM
FORECAST WAS TO UP THE ICE TOTALS FOR THE SOUTHERN PORTION OF THE
REGION. NOW...GENERALLY AROUND A THIRD OF AN INCH OF ICE
ACCUMULATION IS IN THE FORECAST THROUGH AROUND 12Z...WITH AN
ADDITIONAL COUPLE TENTHS OF AN INCH POSSIBLE ALONG THE TN BORDER
INTO THE MID MORNING. AS PRECIP PROGRESSED NORTHWARD DURING THE
EARLY MORNING HOURS...PERRY COUNTY WATER TREATMENT PLANT REPORTED
SLEET ONGOING FOR THE LAST HOUR. AS THE PRECIP CONTINUES TO MOVE
INTO A COLDER AIRMASS...EXPECT THE WARM NOSE TO BECOME LESS
PRONOUNCED...AND SLEET TO TRANSITION TO SNOW NORTH OF THE JKL
OFFICE. OVERALL...PRECIP TYPES WERE SIMILAR TO PREVIOUS FORECAST
FOR THE EARLY MORNING HOURS...WITH TWEAKS MADE BASED ON NEW MODEL
TRENDS FOR TEMPERATURE DIFFERENCES AT THE SURFACE AND ALOFT.
AS WE HEAD TOWARDS DAYBREAK...TEMPERATURES ALOFT WILL CONTINUE TO
TREND COLDER AS WINDS BECOME MORE NORTHERLY AND THE SURFACE LOW
NEARS CLOSER TO THE REGION. THIS WILL TRANSITION ANY MIXED
PRECIPITATION TO ALL SNOW ACROSS MUCH OF THE CWA. A FEW SPOTS ALONG
THE TN BORDER MAY CONTINUE TO SEE SOME FREEZING RAIN MIXING IN
THROUGH THE MID MORNING HOURS BEFORE TEMPERATURES FINALLY COOL
ENOUGH IN THE LOW/MID LEVELS TO PROMOTE ALL SNOW. A STRONG JET
SIGNATURE IS SET UP IN A SOUTH TO NORTH FASHION...STRETCHING FROM
ALABAMA...THROUGH WEST CENTRAL TN AND KY...AND INTO INDIANA. THIS
IS PULLING AN ABUNDANT AMOUNT OF MOISTURE INTO THE REGION WHICH
WILL GREATLY IMPACT US THROUGH THE DAY TODAY. OVERALL THIS SYSTEM
IS CONTINUING TO LOOK VERY CONVECTIVE IN NATURE DURING THE
AFTERNOON...WITH SOUNDINGS MUCH LIKE YOU WOULD SEE WITH SUMMER
TIME THUNDERSTORM ACTIVITY. THIS INCLUDES DEEP LAPSE RATES AND
VEERING WINDS. THE ONLY DIFFERENCE IS MUCH COOLER LOW AND MID
LEVEL TEMPERATURES RESULTING IN A STRONG INVERSION /HENCE THE WARM
NOSE/. WITH SUCH A SET UP IN PLACE...EXPECT HIGH SNOWFALL RATES
THROUGHOUT THE DAY WITH BANDING OF SNOW LIKELY...PEAKING IN THE
AFTERNOON WITH THE GREATEST LAPSE RATES/INSTABILITY. MODELS ARE
CONTINUING TO PIN POINT THE GREATEST SWATH OF SNOW ACROSS THE
NORTHERN HALF OF THE CWA...BUT ARE ALSO CONTINUING TO INCREASE THE
AMOUNT OF QPF WITH THE STRONG MOISTURE ADVECTION CURRENTLY TAKING
PLACE.
AS THE SURFACE LOW REACHES EASTERN TN THIS EVENING...WE MAY SEE SOME
DRY SLOTTING TAKING PLACE...ESPECIALLY IN THE SOUTHEAST PORTION OF
THE CWA. THIS MAY REDUCE SNOWFALL RATES BRIEFLY IN THIS
LOCATION...BUT MOISTURE SHOULD REMAIN DEEP ENOUGH TO PREVENT ANY
FREEZING DRIZZLE FROM OCCURRING. AS THE LOW CONTINUES TO SHIFT
EASTWARD THROUGHOUT THE OVERNIGHT...WE WILL FIND OURSELF ON THE NW
EDGE OF THE SYSTEM...WITH COLDER AIR CONTINUING TO FILTER
IN...COMBINING WITH WRAP AROUND MOISTURE OFF THE ATLANTIC. WE WILL
LOSE OUR WIND SHEER AND BEST INSTABILITY...AND SNOW WILL BECOME MORE
STRATIFORM IN NATURE. THIS WILL RESULT IN LIGHTER QPF THOUGH STILL
SIGNIFICANT AMOUNTS WITH COLDER AIR AND HIGHER SNOW RATIOS
THROUGHOUT THE OVERNIGHT HOURS TONIGHT...AND EVEN INTO THE DAY
TOMORROW. SNOW WILL SLOWLY TAPER OFF DURING THE DAY SATURDAY AS THE
LOW CONTINUES TO SHIFT EAST OF THE REGION. EXPECT IT TO LINGER
LONGEST IN THE FAR SOUTHEAST AND HIGH TERRAIN DUE TO THE UPSLOPE
FLOW THAT WILL SET UP.
AS OF NOW...LOOKING AT BETWEEN 4 AND 7 INCHES ALONG THE TN
BORDER...ALONG WITH THE THIRD TO HALF OF AN INCH OF ICE FROM THE
FREEZING RAIN THAT OCCURS THIS MORNING. TOTALS WILL INCREASE AS
YOU GO NORTHWARD...WITH BETWEEN 12 AND 14 INCHES ACROSS BREATHITT
COUNTY. TOTALS WILL BE THE HIGHEST IN THE NORTHEAST PORTION OF THE
CWA...CLOSER TO THE MOISTURE ADVECTION THAT WILL OCCUR OFF THE
ATLANTIC SEABOARD THIS AFTERNOON AND THE BEST ABOVE MENTIONED
BANDING. HERE...FORECASTED TOTALS HAVE BEEN INCREASED TO 17 TO
ALMOST 19 INCHES. AS YOU MOVE FARTHER WEST...CLOSER TO
STANTON...14 TO 16 INCHES WILL FALL. LOCALLY HIGHER AMOUNTS WILL
BE POSSIBLE ACROSS ALL OF EASTERN KY.
STILL CONCERNED ABOUT POSSIBLE WIND AND BLOWING SNOW...AS WELL AS
POWER OUTAGES DUE TO THE WIND AND/OR THE SHEER WEIGHT OF THE SNOW.
SOME WEAK STRUCTURES MAY ALSO BE AT RISK OF COLLAPSING AS UNDER THE
WEIGHT OF THE SNOW. FURTHERMORE...ROADS ARE ALREADY BECOMING QUITE
HAZARDOUS IN THE SOUTH WITH THE FREEZING RAIN OCCURRING. CONDITIONS
WILL CONTINUE TO DETERIORATE ACROSS EASTERN KY AS THE HEAVIEST SNOW
BEGINS TO SET IN. WILL CONTINUE TO HIGHLIGHT THESE CONCERNS IN OUR
PUBLIC PRODUCTS.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 423 AM EST FRI JAN 22 2016
THE EXTENDED FORECAST PERIOD BEGINS ON SATURDAY NIGHT WITH A
PROGRESSIVE AND ACTIVE UPPER LEVEL PATTERN. DURING THIS TIME A
STRONG CLOSED UPPER LOW IS EXITING THE REGION INTO THE MIDDLE
ATLANTIC AREA. DURING THIS TIME...SOME WRAP AROUND MOISTURE STILL
LINGERS INTO EASTERN KENTUCKY WHERE SOME SNOW SHOWERS WILL LINGER
THROUGH MUCH OF SATURDAY NIGHT BEFORE FINALLY EXITING BY SUNDAY
MORNING. WITH CLOUD COVER DECREASING AND A LARGE SNOWPACK OVER THE
AREA...MORNING TEMPERATURES SUNDAY MORNING WILL FALL INTO THE
SINGLE DIGITS. DURING THE DAY ON SUNDAY AND THROUGH MONDAY
AFTERNOON...A NUPPER LEVEL RIDGE WILL KEEP THE AREA DRY.
BY MONDAY NIGHT...A FAST MOVING SYSTEM DEEP TROUGH WILL BRING
MORE PRECIP INTO THE AREA. WARMER SURFACE TEMPERATURES MAY KEEP
MOST OF THE PRECIP AS RAIN BUT WILL LIKELY SEE SOME SNOW MIX IN
MONDAY NIGHT INTO TUESDAY ESPECIALLY IN THE HIGHER ELEVATIONS. A
COLDER AIR MASS WILL MOVE IN BEHIND THIS FRONT AS A PERIOD OF
UPSLOPE SNOW SHOWERS IS ANTICIPATED. WITH MOISTURE ON THE
DECREASE AS THIS FEATURE EXITS...SNOW WILL COME TO AN END BY
WEDNESDAY EVENING. WITH THE AREA CONTINUING TO BE IN NORTHWEST
FLOW INTO THURSDAY...ANOTHER FAST MOVING SYSTEM WILL BRING ANOTHER
SHOT OF MOISTURE INTO THE AREA. THUS WILL PUT IN ANOTHER ROUND OF
SNOW SHOWERS. THESE WAVES ARE A BIT MOISTURE STARVED SO NOT
EXPECTING MUCH ACCUMULATION RIGHT AT THIS TIME. THE ONE FACTOR
THAT COULD MEAN SLIGHTLY MORE SNOW IS HOW THE MODELS HANDLE ANY
SNOW PACK ON THE GROUND HEADING INTO THESE WEAKER WAVES.
OVERALL...THE EXTENDED IS CERTAINLY LESS ACTIVE THAN THE SHORT
TERM.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 706 AM EST FRI JAN 22 2016
A STRONG WINTER SYSTEM IS STARTING TO BEAR DOWN ACROSS EASTERN
KENTUCKY. WHAT STARTED OUT AS A MIXTURE OF FREEZING RAIN AND SLEET
ACROSS KSME AND KLOZ IS NOW STARTING TO TRANSITION TO ALL SNOW.
ELSEWHERE...SNOW IS SETTING IN AND WILL PICK UP IN INTENSITY
THROUGH THE MORNING HOURS. IFR TO LIFR CONDITIONS ARE EXPECTED
THROUGHOUT THE DAY TODAY AS HEAVY SNOW SETS IN...ALONG WITH LOW
CEILINGS AND THE POTENTIAL FOR BLOWING SNOW. BY OVERNIGHT...SNOW
INTENSITIES SHOULD LIGHTEN UP A BIT...THOUGH IFR CONDITIONS WILL
LIKELY PERSIST FOR BOTH CIGS AND VIS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 7 PM EST SATURDAY FOR KYZ044-050>052-
058>060-068-069-079-080-083>088-104-106>120.
&&
$$
UPDATE...JVM
SHORT TERM...JMW
LONG TERM...SHALLENBERGER
AVIATION...JMW
[top]
Area Forecast Discussion
National Weather Service Louisville KY
835 AM EST FRI JAN 22 2016
...Forecast Update...
Updated at 830 AM EST Fri Jan 22 2016
Enough cool air has filtered in aloft to switch precip over to all
snow, even down to the Tennessee border. Leading edge of the main
snow shield is roughly up to I-64, with the heavier snow along and
south of the Parkways at this time. Expect the northward expansion
to continue through late morning before it starts to pivot.
Another NE-SW oriented band is taking shape over SW Indiana and
western Kentucky, and should get most locations in on accumulating
snow before it`s done.
Forecast update will go out shortly to adjust hourly POP trends in
Indiana, and precip type in south-central Kentucky.
Updated at 645 AM EST Fri Jan 22 2016
Quick update this morning to weather grids and amounts. The latest
guidance including runs of the HRRR, the 06Z NAM and the 03Z SREF
have backed off snow amounts slightly along the river, including the
Louisville metro. Given observational trends and this guidance,
have just tweaked amounts down slightly in this area. Do have
concerns with such an intense snow band setting up to the south,
that the northern edge may struggle to overcome the drier air.
Therefore, have just shaved an inch and gone with 3-7 inches in
Louisville and points along the Ohio River. We will continue to fine-
tune this as the snow continues to fill in on radar and trends
become more apparent.
The other tweak was to linger freezing precipitation in the south
just a bit longer. KHOP has quickly crashed their thermal profiles
and have now gone to snow, and getting some reports near BWG of
sleet mixing in, so the column is certainly cooling and think we
will see a rapid transition to snow over the next couple hours over
all of our CWA. Products have already been updated.
.SHORT TERM (Now through Saturday)...
Issued at 400 AM EST Fri Jan 22 2016
...WINTER STORM TO AFFECT THE AREA TODAY THROUGH SATURDAY MORNING...
...SIGNIFICANT SNOW AND SOME ICE ACCUMULATIONS EXPECTED ACROSS THE
REGION...
...DANGEROUS TRAVEL CONDITIONS EXPECTED TODAY INTO SATURDAY
MORNING...
SYNOPTIC OVERVIEW
=================
A strong PV anomaly is rounding the base of a southern stream trough
this morning, whose ascent has helped foster a deepening surface low
which is currently analyzed over portions of northern Alabama. This
will lift northeast through the day today and into tonight.
All the ingredients are coming together for a major winter storm today
into tonight across the Ohio Valley. A coupled jet structure, with a
strong anticyclonically-curved 125+ knot jet noted over northern IN/OH
has led to very strong moisture transport from the Gulf of Mexico into
TN and southern KY this morning. This moisture is being fed above a
cold dome at the surface which has led to freezing rain this morning
over southern KY. This TROWAL will continue to wrap northwest on the
northwest side of this deepening cyclone today, helping to tighten the
mid-level thermal gradient and increase forcing for ascent later this
morning into this afternoon across the region. This deep, moist
forcing will result in widespread precipitation moving through KY and
portions of southern IN today.
MODEL PREFERENCE
=================
The HRRR has had a very good handle on the current situation, thus have
leaned heavily on that solution for the next 6-9 hours. Beyond that,
blended HRRR guidance more with a mix of the hi-res WRF-ARW and NAM
fields. This led to an overall increase in the QPF across much of
central and south-central KY. Hi-res guidance was preferred as it
should handle the banded/convective nature of this snowfall that we are
likely to see.
SENSIBLE WEATHER AND IMPACTS
============================
As mentioned above, freezing rain has already accumulated from a glaze
up to a tenth of an inch across portions of southern KY, especially
near the BWG area. This is the result of the warm nose from the
moisture transport to the south nudging into the region. However,
recent reports and CC data out of HPX is showing the thermal profile is
rapidly crashing as cold air is wrapped into this system from the
northwest. Therefore, expect precip to quickly transition to snow from
the northwest across south-central KY this morning, with most areas
going all snow by around 12/13Z. Before this transition occurs, there
could be up to 0.3" of ice across roughly our southern two tiers of
counties in KY.
Further north, while some sleet may mix in at onset before the column
evaporatively cools, think any precip will quickly go to snow. Forecast
cross sections depict deep omega within the dendridic growth zone, with
negative EPV values suggesting CSI and soundings even suggesting some
very weak convective instability as well. These values being above the
strong f-gen circulation suggest banding of snowfall is very likely to
occur, with the most preferred area across south central-KY near the
Parkways (where amounts have been upped). A rumble of thunder is not
completely out of the question in these heavier bands, as snowfall
rates will likely exceed 2 inches per hour for periods of time.
Along the Ohio River, uncertainty still remains. It appears the
expected strong gradient is going to set up very near the river, which
will obviously have massive impacts on amounts especially for the
Louisville metro. For now, will mainly continue with the going
forecast, but this is still subject to shift today as the bands set up.
AMOUNTS AND CONFIDENCE
======================
Have high confidence in a band of over a foot of snowfall setting up
across portions of central KY, likely between the Parkways. It is here
where the forecast cross-sections and instability fields are showing
the potential for a potent band of snowfall to set up. Would not be
surprised at all to see amounts locally in excess of 18 inches come out
of this band. This localized band will likely include southern
portions of the LEX metro.
25-30 miles on either side of this band, have fairly high confidence in
a swath of 8-12 inches. This would include areas like Bowling Green to
Glasgow, the north of the band into E-Town and Frankfort.
Have only low/medium confidence in areas to the north of this along the
Ohio River. As mentioned above, this is going to be a tight gradient
where the edge of the strong synoptic forcing/def band is battling dry
air to the north. Will keep in a gradient of 4-8 inches across this
region, which includes the Louisville metro. This gradient is likely
going to need to be tightened and fine-tuned through the day today.
Across our northern tier of counties in southern IN, have high
confidence in only a trace to locally 3 inches in this region. The dry
air will win out here for the most part.
Winds will gust around 35 mph today which will cause reductions in
visibility in the heaviest snowfall areas, along with some scattered
power outages especially across south-central KY where some icing is
expected to occur (we`ve already had some reports of outages down there
this morning). Some drifting of snow is also likely to occur given
these winds.
.LONG TERM (Saturday Night through Thursday)...
Issued at 300 AM EST Fri Jan 22 2016
Deep closed low off the eastern US coast will continue to lift out
Saturday night and Sunday while mid-level ridging builds across our
region. This will lead to dry conditions across the region Saturday
night through Sunday night. Main challenge in this period will be
overnight temperatures. We expect to have a decent snowpack on the
ground early in the period. That combined with clearing skies and
light winds will yield cold temperatures. The blended guidance is
trending downward but is not capturing the latest raw data yet.
Therefore, have gone well below guidance across much of region.
We`re likely to see very low single digit to single digit below zero
readings Saturday night and Sunday morning. Temperatures will
recover a bit on Sunday with mostly sunny skies. However, plan on
uttercutting guidance over the snowpack. Highs will range from the
low 30s over less covered areas to mid-upper 20s across the
snowpack. That may be a bit generous, but will continue to monitor
trends over the next few days. We`ll start to get a southwesterly
flow Sunday night as the high moves off to the east coast. This
should keep temperatures a bit warmer with lows mainly in the upper
teens to lower 20s.
Still looking at a progressive pattern aloft for the new work week
with an upper trough swinging through the region Monday and Monday
night. This system still looks to tap into some gulf moisture and
will bring rain showers to the region. With continued warm
advection, we should see temperatures above freezing, but guidance
is probably going to be overdone here with the melting snowpack.
We`ll need to continue to watch this time frame for p-type issues
because if low level temps remain cold enough we could have mixed
precip.
Once the surface feature moves through, upper trof hangs back from
the Great Lakes down through the Mississippi Valley, so we`ll stay a
bit unsettled with with below normal temps, plenty of cloud cover,
and small chances for a few light rain or snow showers especially in
the Thursday to Friday time frame.
&&
.AVIATION (00Z TAF Update)...
Updated at 634 AM EST Fri Jan 22 2016
Impactful Winter Storm expected to continue to ramp up this morning.
Precip has already began at BWG and will continue to slowly spread
north into LEX/SDF through the morning hours.
BWG...
Onset: Ongoing
Now P-TYPE: Sleet changing to snow in the next hour.
Heaviest: 7 AM CST to late this afternoon.
Conditions: low MVFR/IFR ceilings and visibility during lighter
snow, Minimums during heavy snow.
Winds: Steady NE this morning at 15 to 20 knots with gusts to 25-30 knots.
Shifting to the north late this afternoon.
SDF...
Onset: Around 9 AM EST
P-TYPE: All snow
Heaviest: 1 PM EST to early evening
Conditions: low MVFR/IFR ceilings and visibility during lighter
snow, low IFR/near minimums during heavier snow.
Winds: NE increasing in magnitude to 15 knots,
gusts 25-30 knots today. Blowing/Drifting snow possible.
LEX...
Onset: Around 8 AM EST
P-TYPE: All snow
Heaviest: Noon EST mid evening
Conditions: low MVFR/IFR ceilings and visibility
during lighter snow, minimums in heavier snow.
Winds: Steady NE winds increasing in magnitude to 15 knots, with
gusts 25-30 knots today. Blowing/Drifting snow possible.
&&
.LMK Watches/Warnings/Advisories...
KY...Winter Storm Warning until 7 AM EST /6 AM CST/ Saturday for
KYZ023>043-045>049-053>057-061>067-070>078-081-082.
IN...Winter Weather Advisory until 7 AM EST /6 AM CST/ Saturday for
INZ076>079-083.
Winter Storm Warning until 7 AM EST /6 AM CST/ Saturday for
INZ084-089>092.
&&
$$
Update.........RAS
Short Term.....KJD
Long Term......MJ
Aviation.......KJD
AREA FORECAST DISCUSSION
National Weather Service Paducah KY
608 AM CST FRI JAN 22 2016
.UPDATE...
Issued at 552 AM CST FRI JAN 22 2016
The snow has come to an end over much of southeast Missouri with
exception of New Madrid...Mississippi...and Scott counties...so we
have expired/cancelled the Warning and Advisory for the remainder
of our Missouri counties.
Latest radar trends are pushing the north edge of the snow shield
a county or so northwest of the Winter Storm Warning area. We do
not expect this to last long enough for 4+" to accumulate, so we
have continued the Advisory for Scott, Alexander and Pulaski through
21Z...and expanded it northeast through Gallatin and Posey
counties. There may be a dusting in the counties bordering the
Advisory in southern Illinois and southwest Indiana, but not
enough to be much of a problem, especially with the gusty north
winds blowing it around.
All that`s left now is to see just how much snow this "West
Kentucky Blizzard" can dump.
The AVIATION section has been updated for the 12Z TAF issuance.
&&
.SHORT TERM...(Today through Sunday)
Issued at 352 AM CST FRI JAN 22 2016
According to dual pol radar data it appears that much of the
Warning area has changed over to snow, with the exception of
Calloway county eastward along the Tennessee border. A change over
to all snow is expected over those areas by 12Z. The Winter Storm
Warning is looking pretty good, and no changes are planned at
this time. Snow amounts over much of west Kentucky may be just a
bit higher with a max now of around 12" in Muhlenberg, Christian
and Todd counties.
The problem areas for the snow forecast continue to be the
northwest periphery of the existing warning area. The Evansville
area southwest to Hardin county may not quite reach Warning
criteria of 4", but there may be an area of more advisory level
snows from Alexander county through Johnson and into Saline and
Gallatin counties. Radar is currently showing some increase in
that region and recent HRRR runs are showing the precipitation
shield reaching those areas now. Not sure if it will last long
enough to warrant an Advisory, so for now will just keep an eye
out for observations from those regions and adjust as needed.
Latest radar trends indicate that southeast Missouri outside of
New Madrid and Mississippi counties has dried out as expected.
Will let the Warning and Advisory expire as scheduled at 12Z. May
need to extend Alexander and Pulaski for awhile, but will make
that decision near 12Z. Hopefully, we will have enough
observations by then to decide if the Advisory needs to be
expanded to the northeast any at all.
It appears that much of the measurable precipitation will be done
by 00Z, but will leave the 06Z expiration of the primary portion
of the Warning. However, we will likely be cancelling it in chunks
this afternoon, as the snow comes to an end from west to east.
Skies will clear Saturday, but temperatures will struggle to climb
above freezing, especially over the snowpack. The surface high
will settle over the region Saturday night, so some single digit
lows are expected, especially over the Pennyrile. Wouln`t be
surprised if a few locations approach 0. South winds will try to
bring a warm up on Sunday, but with the snowpack hanging around,
it may be muted compared to the MAV guidance.
.LONG TERM...(Sunday Night through Thursday)
Issued at 352 AM CST FRI JAN 22 2016
By Sunday night, an upper level ridge will be centered overhead with
sfc high pressure continuing to move east of the area. South winds
at the surface will continue to pick up as a storm system over the
central Plains moves east northeast. By 12Z Monday, a sfc low will
be located over the KS/MO border. Throughout the day on Monday, the
sfc low will move northeast toward the western Great Lakes region.
As this occurs, a cold front will move across our area from west to
east. As has been the case for the last few days...models are not
showing too much QPF with this system, as the best moisture is
confined to the north with the actual sfc low. However, we will
continue to maintain low chance POPS with the FROPA. Soundings and
time height charts indicate temperatures are warm enough for
precipitation to fall as rain, at least during the day.
Heading into Monday evening, models differ a bit on the timing of
when exactly the front will clear the CWA. However, will continue to
linger precipitation into the evening/overnight hours, however
believe that any lingering activity should probably be mainly during
the evening. Low level temperature profiles indicate that there
could be a rain/snow mix up in our northern counties. This blends
well with neighboring offices to our north.
Since moisture seems to be lacking on Tuesday, despite the fact that
an upper level trough will be moving through the area, will only
keep low POPS for the eastern sections. Any moisture will be
confined to the low levels, centered around 925mb, so some flurries
would be possible if anything occurred at all.
High pressure builds into the area Tuesday night into Wednesday
providing dry weather. A clipper type system approaches us from the
northwest on Wednesday night into Thursday but should only bring us
some clouds.
&&
.AVIATION...
Issued at 525 PM CST THU JAN 21 2016
It appears that KCGI will miss out on the snowfall...and currently
their ceiling has climbed well into VFR territory. MVFR ceilings
are likely to return at some point. The forecast is quite
optimistic. Once they arrive they should linger through the end
of the period.
Elsewhere, IFR or occasionally lower snows will continue through
the morning, and then slowly come to an end from west to east
this afternoon through sunset. MVFR, if not IFR ceilings are
expected to linger through the end of the period. Northeast to
north winds will gust over 25kts at times through early this
evening...and then will settle down to the 10-15kt range through
the remainder of the night.
&&
.PAH Watches/Warnings/Advisories...
IL...Winter Weather Advisory until 3 PM CST this afternoon for ILZ086-
087-089-092-093.
Winter Storm Warning until midnight CST tonight for ILZ090-091-
094.
MO...Winter Weather Advisory until 3 PM CST this afternoon for MOZ111.
Winter Storm Warning until midnight CST tonight for MOZ112-114.
IN...Winter Weather Advisory until 3 PM CST this afternoon for INZ085.
Winter Storm Warning until midnight CST tonight for INZ086>088.
KY...Winter Storm Warning until midnight CST tonight for KYZ001>022.
&&
$$
UPDATE...DRS
SHORT TERM...DRS
LONG TERM...CW
AVIATION...DRS
AREA FORECAST DISCUSSION
NWS JACKSON KY
706 AM EST FRI JAN 22 2016
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 454 AM EST FRI JAN 22 2016
STEADY PRECIP IS OVERSPREADING OUR SOUTHERN 1/3 TO 1/2 OF THE
CWA AS OF 3AM. WE/VE HAD MULTIPLE REPORTS OF FREEZING RAIN ACROSS
THE FAR SOUTHERN CWA AS THE PRECIP MOVED INTO THE AREA. THIS IS ON
PAR WITH INFORMATION WE RECEIVED FROM OHX AFTER THEY CONDUCTED A
SPECIAL BALLOON LAUNCH...NOTING THAT THE WARM NOSE WAS MUCH MORE
PRONOUNCED THAN MODELS WERE PICKING UP ON. BY 2AM...WILLIAMSBURG
IN WHITLEY COUNTY HAD ALREADY RECEIVED A TENTH OF AN INCH OF ICE
ACCUMULATION. AS SUCH...THE BIGGEST CHANGE IN THE NEAR TERM
FORECAST WAS TO UP THE ICE TOTALS FOR THE SOUTHERN PORTION OF THE
REGION. NOW...GENERALLY AROUND A THIRD OF AN INCH OF ICE
ACCUMULATION IS IN THE FORECAST THROUGH AROUND 12Z...WITH AN
ADDITIONAL COUPLE TENTHS OF AN INCH POSSIBLE ALONG THE TN BORDER
INTO THE MID MORNING. AS PRECIP PROGRESSED NORTHWARD DURING THE
EARLY MORNING HOURS...PERRY COUNTY WATER TREATMENT PLANT REPORTED
SLEET ONGOING FOR THE LAST HOUR. AS THE PRECIP CONTINUES TO MOVE
INTO A COLDER AIRMASS...EXPECT THE WARM NOSE TO BECOME LESS
PRONOUNCED...AND SLEET TO TRANSITION TO SNOW NORTH OF THE JKL
OFFICE. OVERALL...PRECIP TYPES WERE SIMILAR TO PREVIOUS FORECAST
FOR THE EARLY MORNING HOURS...WITH TWEAKS MADE BASED ON NEW MODEL
TRENDS FOR TEMPERATURE DIFFERENCES AT THE SURFACE AND ALOFT.
AS WE HEAD TOWARDS DAYBREAK...TEMPERATURES ALOFT WILL CONTINUE TO
TREND COLDER AS WINDS BECOME MORE NORTHERLY AND THE SURFACE LOW
NEARS CLOSER TO THE REGION. THIS WILL TRANSITION ANY MIXED
PRECIPITATION TO ALL SNOW ACROSS MUCH OF THE CWA. A FEW SPOTS ALONG
THE TN BORDER MAY CONTINUE TO SEE SOME FREEZING RAIN MIXING IN
THROUGH THE MID MORNING HOURS BEFORE TEMPERATURES FINALLY COOL
ENOUGH IN THE LOW/MID LEVELS TO PROMOTE ALL SNOW. A STRONG JET
SIGNATURE IS SET UP IN A SOUTH TO NORTH FASHION...STRETCHING FROM
ALABAMA...THROUGH WEST CENTRAL TN AND KY...AND INTO INDIANA. THIS
IS PULLING AN ABUNDANT AMOUNT OF MOISTURE INTO THE REGION WHICH
WILL GREATLY IMPACT US THROUGH THE DAY TODAY. OVERALL THIS SYSTEM
IS CONTINUING TO LOOK VERY CONVECTIVE IN NATURE DURING THE
AFTERNOON...WITH SOUNDINGS MUCH LIKE YOU WOULD SEE WITH SUMMER
TIME THUNDERSTORM ACTIVITY. THIS INCLUDES DEEP LAPSE RATES AND
VEERING WINDS. THE ONLY DIFFERENCE IS MUCH COOLER LOW AND MID
LEVEL TEMPERATURES RESULTING IN A STRONG INVERSION /HENCE THE WARM
NOSE/. WITH SUCH A SET UP IN PLACE...EXPECT HIGH SNOWFALL RATES
THROUGHOUT THE DAY WITH BANDING OF SNOW LIKELY...PEAKING IN THE
AFTERNOON WITH THE GREATEST LAPSE RATES/INSTABILITY. MODELS ARE
CONTINUING TO PIN POINT THE GREATEST SWATH OF SNOW ACROSS THE
NORTHERN HALF OF THE CWA...BUT ARE ALSO CONTINUING TO INCREASE THE
AMOUNT OF QPF WITH THE STRONG MOISTURE ADVECTION CURRENTLY TAKING
PLACE.
AS THE SURFACE LOW REACHES EASTERN TN THIS EVENING...WE MAY SEE SOME
DRY SLOTTING TAKING PLACE...ESPECIALLY IN THE SOUTHEAST PORTION OF
THE CWA. THIS MAY REDUCE SNOWFALL RATES BRIEFLY IN THIS
LOCATION...BUT MOISTURE SHOULD REMAIN DEEP ENOUGH TO PREVENT ANY
FREEZING DRIZZLE FROM OCCURRING. AS THE LOW CONTINUES TO SHIFT
EASTWARD THROUGHOUT THE OVERNIGHT...WE WILL FIND OURSELF ON THE NW
EDGE OF THE SYSTEM...WITH COLDER AIR CONTINUING TO FILTER
IN...COMBINING WITH WRAP AROUND MOISTURE OFF THE ATLANTIC. WE WILL
LOSE OUR WIND SHEER AND BEST INSTABILITY...AND SNOW WILL BECOME MORE
STRATIFORM IN NATURE. THIS WILL RESULT IN LIGHTER QPF THOUGH STILL
SIGNIFICANT AMOUNTS WITH COLDER AIR AND HIGHER SNOW RATIOS
THROUGHOUT THE OVERNIGHT HOURS TONIGHT...AND EVEN INTO THE DAY
TOMORROW. SNOW WILL SLOWLY TAPER OFF DURING THE DAY SATURDAY AS THE
LOW CONTINUES TO SHIFT EAST OF THE REGION. EXPECT IT TO LINGER
LONGEST IN THE FAR SOUTHEAST AND HIGH TERRAIN DUE TO THE UPSLOPE
FLOW THAT WILL SET UP.
AS OF NOW...LOOKING AT BETWEEN 4 AND 7 INCHES ALONG THE TN
BORDER...ALONG WITH THE THIRD TO HALF OF AN INCH OF ICE FROM THE
FREEZING RAIN THAT OCCURS THIS MORNING. TOTALS WILL INCREASE AS
YOU GO NORTHWARD...WITH BETWEEN 12 AND 14 INCHES ACROSS BREATHITT
COUNTY. TOTALS WILL BE THE HIGHEST IN THE NORTHEAST PORTION OF THE
CWA...CLOSER TO THE MOISTURE ADVECTION THAT WILL OCCUR OFF THE
ATLANTIC SEABOARD THIS AFTERNOON AND THE BEST ABOVE MENTIONED
BANDING. HERE...FORECASTED TOTALS HAVE BEEN INCREASED TO 17 TO
ALMOST 19 INCHES. AS YOU MOVE FARTHER WEST...CLOSER TO
STANTON...14 TO 16 INCHES WILL FALL. LOCALLY HIGHER AMOUNTS WILL
BE POSSIBLE ACROSS ALL OF EASTERN KY.
STILL CONCERNED ABOUT POSSIBLE WIND AND BLOWING SNOW...AS WELL AS
POWER OUTAGES DUE TO THE WIND AND/OR THE SHEER WEIGHT OF THE SNOW.
SOME WEAK STRUCTURES MAY ALSO BE AT RISK OF COLLAPSING AS UNDER THE
WEIGHT OF THE SNOW. FURTHERMORE...ROADS ARE ALREADY BECOMING QUITE
HAZARDOUS IN THE SOUTH WITH THE FREEZING RAIN OCCURRING. CONDITIONS
WILL CONTINUE TO DETERIORATE ACROSS EASTERN KY AS THE HEAVIEST SNOW
BEGINS TO SET IN. WILL CONTINUE TO HIGHLIGHT THESE CONCERNS IN OUR
PUBLIC PRODUCTS.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 423 AM EST FRI JAN 22 2016
THE EXTENDED FORECAST PERIOD BEGINS ON SATURDAY NIGHT WITH A
PROGRESSIVE AND ACTIVE UPPER LEVEL PATTERN. DURING THIS TIME A
STRONG CLOSED UPPER LOW IS EXITING THE REGION INTO THE MIDDLE
ATLANTIC AREA. DURING THIS TIME...SOME WRAP AROUND MOISTURE STILL
LINGERS INTO EASTERN KENTUCKY WHERE SOME SNOW SHOWERS WILL LINGER
THROUGH MUCH OF SATURDAY NIGHT BEFORE FINALLY EXITING BY SUNDAY
MORNING. WITH CLOUD COVER DECREASING AND A LARGE SNOWPACK OVER THE
AREA...MORNING TEMPERATURES SUNDAY MORNING WILL FALL INTO THE
SINGLE DIGITS. DURING THE DAY ON SUNDAY AND THROUGH MONDAY
AFTERNOON...A NUPPER LEVEL RIDGE WILL KEEP THE AREA DRY.
BY MONDAY NIGHT...A FAST MOVING SYSTEM DEEP TROUGH WILL BRING
MORE PRECIP INTO THE AREA. WARMER SURFACE TEMPERATURES MAY KEEP
MOST OF THE PRECIP AS RAIN BUT WILL LIKELY SEE SOME SNOW MIX IN
MONDAY NIGHT INTO TUESDAY ESPECIALLY IN THE HIGHER ELEVATIONS. A
COLDER AIR MASS WILL MOVE IN BEHIND THIS FRONT AS A PERIOD OF
UPSLOPE SNOW SHOWERS IS ANTICIPATED. WITH MOISTURE ON THE
DECREASE AS THIS FEATURE EXITS...SNOW WILL COME TO AN END BY
WEDNESDAY EVENING. WITH THE AREA CONTINUING TO BE IN NORTHWEST
FLOW INTO THURSDAY...ANOTHER FAST MOVING SYSTEM WILL BRING ANOTHER
SHOT OF MOISTURE INTO THE AREA. THUS WILL PUT IN ANOTHER ROUND OF
SNOW SHOWERS. THESE WAVES ARE A BIT MOISTURE STARVED SO NOT
EXPECTING MUCH ACCUMULATION RIGHT AT THIS TIME. THE ONE FACTOR
THAT COULD MEAN SLIGHTLY MORE SNOW IS HOW THE MODELS HANDLE ANY
SNOW PACK ON THE GROUND HEADING INTO THESE WEAKER WAVES.
OVERALL...THE EXTENDED IS CERTAINLY LESS ACTIVE THAN THE SHORT
TERM.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 706 AM EST FRI JAN 22 2016
A STRONG WINTER SYSTEM IS STARTING TO BEAR DOWN ACROSS EASTERN
KENTUCKY. WHAT STARTED OUT AS A MIXTURE OF FREEZING RAIN AND SLEET
ACROSS KSME AND KLOZ IS NOW STARTING TO TRANSITION TO ALL SNOW.
ELSEWHERE...SNOW IS SETTING IN AND WILL PICK UP IN INTENSITY
THROUGH THE MORNING HOURS. IFR TO LIFR CONDITIONS ARE EXPECTED
THROUGHOUT THE DAY TODAY AS HEAVY SNOW SETS IN...ALONG WITH LOW
CEILINGS AND THE POTENTIAL FOR BLOWING SNOW. BY OVERNIGHT...SNOW
INTENSITIES SHOULD LIGHTEN UP A BIT...THOUGH IFR CONDITIONS WILL
LIKELY PERSIST FOR BOTH CIGS AND VIS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 7 PM EST SATURDAY FOR KYZ044-050>052-
060-104-106-107-119.
WINTER STORM WARNING UNTIL 7 PM EST SATURDAY FOR KYZ058-059-068-
069-079-080-083>088-108>118-120.
&&
$$
SHORT TERM...JMW
LONG TERM...SHALLENBERGER
AVIATION...JMW
Area Forecast Discussion
National Weather Service Louisville KY
650 AM EST FRI JAN 22 2016
...Forecast Update...
Updated at 645 AM EST Fri Jan 22 2016
Quick update this morning to weather grids and amounts. The latest
guidance including runs of the HRRR, the 06Z NAM and the 03Z SREF
have backed off snow amounts slightly along the river, including the
Louisville metro. Given observational trends and this guidance,
have just tweaked amounts down slightly in this area. Do have
concerns with such an intense snow band setting up to the south,
that the northern edge may struggle to overcome the drier air.
Therefore, have just shaved an inch and gone with 3-7 inches in
Louisville and points along the Ohio River. We will continue to fine-
tune this as the snow continues to fill in on radar and trends
become more apparent.
The other tweak was to linger freezing precipitation in the south
just a bit longer. KHOP has quickly crashed their thermal profiles
and have now gone to snow, and getting some reports near BWG of
sleet mixing in, so the column is certainly cooling and think we
will see a rapid transition to snow over the next couple hours over
all of our CWA. Products have already been updated.
.SHORT TERM (Now through Saturday)...
Issued at 400 AM EST Fri Jan 22 2016
...WINTER STORM TO AFFECT THE AREA TODAY THROUGH SATURDAY MORNING...
...SIGNIFICANT SNOW AND SOME ICE ACCUMULATIONS EXPECTED ACROSS THE
REGION...
...DANGEROUS TRAVEL CONDITIONS EXPECTED TODAY INTO SATURDAY
MORNING...
SYNOPTIC OVERVIEW
=================
A strong PV anomaly is rounding the base of a southern stream trough
this morning, whose ascent has helped foster a deepening surface low
which is currently analyzed over portions of northern Alabama. This
will lift northeast through the day today and into tonight.
All the ingredients are coming together for a major winter storm today
into tonight across the Ohio Valley. A coupled jet structure, with a
strong anticyclonically-curved 125+ knot jet noted over northern IN/OH
has led to very strong moisture transport from the Gulf of Mexico into
TN and southern KY this morning. This moisture is being fed above a
cold dome at the surface which has led to freezing rain this morning
over southern KY. This TROWAL will continue to wrap northwest on the
northwest side of this deepening cyclone today, helping to tighten the
mid-level thermal gradient and increase forcing for ascent later this
morning into this afternoon across the region. This deep, moist
forcing will result in widespread precipitation moving through KY and
portions of southern IN today.
MODEL PREFERENCE
=================
The HRRR has had a very good handle on the current situation, thus have
leaned heavily on that solution for the next 6-9 hours. Beyond that,
blended HRRR guidance more with a mix of the hi-res WRF-ARW and NAM
fields. This led to an overall increase in the QPF across much of
central and south-central KY. Hi-res guidance was preferred as it
should handle the banded/convective nature of this snowfall that we are
likely to see.
SENSIBLE WEATHER AND IMPACTS
============================
As mentioned above, freezing rain has already accumulated from a glaze
up to a tenth of an inch across portions of southern KY, especially
near the BWG area. This is the result of the warm nose from the
moisture transport to the south nudging into the region. However,
recent reports and CC data out of HPX is showing the thermal profile is
rapidly crashing as cold air is wrapped into this system from the
northwest. Therefore, expect precip to quickly transition to snow from
the northwest across south-central KY this morning, with most areas
going all snow by around 12/13Z. Before this transition occurs, there
could be up to 0.3" of ice across roughly our southern two tiers of
counties in KY.
Further north, while some sleet may mix in at onset before the column
evaporatively cools, think any precip will quickly go to snow. Forecast
cross sections depict deep omega within the dendridic growth zone, with
negative EPV values suggesting CSI and soundings even suggesting some
very weak convective instability as well. These values being above the
strong f-gen circulation suggest banding of snowfall is very likely to
occur, with the most preferred area across south central-KY near the
Parkways (where amounts have been upped). A rumble of thunder is not
completely out of the question in these heavier bands, as snowfall
rates will likely exceed 2 inches per hour for periods of time.
Along the Ohio River, uncertainty still remains. It appears the
expected strong gradient is going to set up very near the river, which
will obviously have massive impacts on amounts especially for the
Louisville metro. For now, will mainly continue with the going
forecast, but this is still subject to shift today as the bands set up.
AMOUNTS AND CONFIDENCE
======================
Have high confidence in a band of over a foot of snowfall setting up
across portions of central KY, likely between the Parkways. It is here
where the forecast cross-sections and instability fields are showing
the potential for a potent band of snowfall to set up. Would not be
surprised at all to see amounts locally in excess of 18 inches come out
of this band. This localized band will likely include southern
portions of the LEX metro.
25-30 miles on either side of this band, have fairly high confidence in
a swath of 8-12 inches. This would include areas like Bowling Green to
Glasgow, the north of the band into E-Town and Frankfort.
Have only low/medium confidence in areas to the north of this along the
Ohio River. As mentioned above, this is going to be a tight gradient
where the edge of the strong synoptic forcing/def band is battling dry
air to the north. Will keep in a gradient of 4-8 inches across this
region, which includes the Louisville metro. This gradient is likely
going to need to be tightened and fine-tuned through the day today.
Across our northern tier of counties in southern IN, have high
confidence in only a trace to locally 3 inches in this region. The dry
air will win out here for the most part.
Winds will gust around 35 mph today which will cause reductions in
visibility in the heaviest snowfall areas, along with some scattered
power outages especially across south-central KY where some icing is
expected to occur (we`ve already had some reports of outages down there
this morning). Some drifting of snow is also likely to occur given
these winds.
.LONG TERM (Saturday Night through Thursday)...
Issued at 300 AM EST Fri Jan 22 2016
Deep closed low off the eastern US coast will continue to lift out
Saturday night and Sunday while mid-level ridging builds across our
region. This will lead to dry conditions across the region Saturday
night through Sunday night. Main challenge in this period will be
overnight temperatures. We expect to have a decent snowpack on the
ground early in the period. That combined with clearing skies and
light winds will yield cold temperatures. The blended guidance is
trending downward but is not capturing the latest raw data yet.
Therefore, have gone well below guidance across much of region.
We`re likely to see very low single digit to single digit below zero
readings Saturday night and Sunday morning. Temperatures will
recover a bit on Sunday with mostly sunny skies. However, plan on
uttercutting guidance over the snowpack. Highs will range from the
low 30s over less covered areas to mid-upper 20s across the
snowpack. That may be a bit generous, but will continue to monitor
trends over the next few days. We`ll start to get a southwesterly
flow Sunday night as the high moves off to the east coast. This
should keep temperatures a bit warmer with lows mainly in the upper
teens to lower 20s.
Still looking at a progressive pattern aloft for the new work week
with an upper trough swinging through the region Monday and Monday
night. This system still looks to tap into some gulf moisture and
will bring rain showers to the region. With continued warm
advection, we should see temperatures above freezing, but guidance
is probably going to be overdone here with the melting snowpack.
We`ll need to continue to watch this time frame for p-type issues
because if low level temps remain cold enough we could have mixed
precip.
Once the surface feature moves through, upper trof hangs back from
the Great Lakes down through the Mississippi Valley, so we`ll stay a
bit unsettled with with below normal temps, plenty of cloud cover,
and small chances for a few light rain or snow showers especially in
the Thursday to Friday time frame.
&&
.AVIATION (12Z TAF Update)...
Updated at 634 AM EST Fri Jan 22 2016
Impactful Winter Storm expected to continue to ramp up this morning.
Precip has already began at BWG and will continue to slowly spread
north into LEX/SDF through the morning hours.
BWG...
Onset: Ongoing
Now P-TYPE: Sleet changing to snow in the next hour.
Heaviest: 7 AM CST to late this afternoon.
Conditions: low MVFR/IFR ceilings and visibility during lighter
snow, Minimums during heavy snow.
Winds: Steady NE this morning at 15 to 20 knots with gusts to 25-30 knots.
Shifting to the north late this afternoon.
SDF...
Onset: Around 9 AM EST
P-TYPE: All snow
Heaviest: 1 PM EST to early evening
Conditions: low MVFR/IFR ceilings and visibility during lighter
snow, low IFR/near minimums during heavier snow.
Winds: NE increasing in magnitude to 15 knots,
gusts 25-30 knots today. Blowing/Drifting snow possible.
LEX...
Onset: Around 8 AM EST
P-TYPE: All snow
Heaviest: Noon EST mid evening
Conditions: low MVFR/IFR ceilings and visibility
during lighter snow, minimums in heavier snow.
Winds: Steady NE winds increasing in magnitude to 15 knots, with
gusts 25-30 knots today. Blowing/Drifting snow possible.
&&
.LMK Watches/Warnings/Advisories...
KY...Winter Storm Warning until 7 AM EST /6 AM CST/ Saturday for
KYZ024-026>029-034>043-045>049-053>057-061>067-070>078-081-
082.
Winter Storm Warning until 7 AM EST /6 AM CST/ Saturday for
KYZ023-025-030>033.
IN...Winter Weather Advisory until 7 AM EST /6 AM CST/ Saturday for
INZ076>079-083.
Winter Storm Warning until 7 AM EST /6 AM CST/ Saturday for
INZ084-089>092.
&&
$$
Update.........KJD
Short Term.....KJD
Long Term......MJ
Aviation.......KJD
AREA FORECAST DISCUSSION
NWS JACKSON MS
411 AM CST FRI JAN 22 2016
...WINTER WEATHER REMAINS POSSIBLE OVER MAINLY NORTHERN PORTIONS OF
THE ARKLAMISS TODAY...
.DISCUSSION...TODAY AND TONIGHT...A WINTER STORM IS DEVELOPING THIS
MORNING OVER PORTIONS OF THE ARKLAMISS DELTA REGION...BUT THERE IS
REASON TO BELIEVE THAT SNOW AMOUNTS COULD BE A LITTLE LESS THAN
EXPECTED BASED ON CURRENT TRENDS. TWO CENTERS OF GREATER LIFT
ASSOCIATED WITH THE UPPER LOW ARE RESULTING IH SIGNIFICANT
PRECIPITATION...ONE OVER THE LOWER DELTA REGION AND THE OTHER OVER
CENTRAL/EASTERN ARKANSAS INTO NW MS. IT IS THE LATTER PRECIP AREA
THAT IS OF GREATEST CONCERN AS IT IS TENDING TO STAY NORTH OF THE
FORECAST AREA. MEANWHILE THE AREA OVER THE LOWER DELTA REGION IS ON A
PACE TO STAY AHEAD THE PRECIP TRANSITION ZONE MEANING LESS CHANCE FOR
ACCUMULATING SNOW. MOREOVER THE HRRR HAS BEEN RATHER INSISTENT IN
SHOWING QUICKER DISSIPATION OF PRECIP THIS MORNING AS THE UPPER LOW
SHIFTS EAST. ADDING ALL OF THIS UP WOULD SUGGEST LESSER SNOW
AMOUNTS...BUT AM NOT NEARLY CONFIDENT ENOUGH TO DOWNGRADE PRODUCTS AS
IT WILL ONLY TAKE A ONE-TWO HOUR BURST OF HEAVIER SNOW TO CREATE
IMPACTS. FOR NOW WILL HOLD THE COURSE BUT DON`T BE SURPRISED IF THERE
ARE CHANGES IN THE PRODUCTS LATER THIS MORNING.
OTHERWISE...THE STRONG COLD ADVECTION REGIME IS RIGHT ON TRACK WITH
A CONSIDERABLE AMOUNT OF FLURRIES/DRIZZLE AND EVEN FREEZING DRIZZLE
POSSIBLE FOR MOST OF TODAY INTO THE EVENING FOR LOCATIONS GENERALLY
ALONG AND NORTH OF THE I-20 CORRIDOR. STRONG NORTHWEST/NORTHERLY LOW
LEVEL FLOW HAS DEVELOPED AND WILL CONTINUE THE WIND ADVISORY IN THE
DELTA REGION. LOOK FOR TEMPERATURES TO FALL WELL INTO THE 20S
OVERNIGHT. /EC/
SATURDAY THROUGH NEXT THURSDAY...THE SURFACE LOW WILL
CONTINUE TO LIFT NORTHEAST UP THE EAST COAST AS THE WESTERN
PERIPHERY OF THE UPPER TROUGH EXITS THE REGION SATURDAY. CLOUDS
SHOULD EXIT THE CENTRAL AND EASTERN PORTIONS OF THE FORECAST AREA
SATURDAY MORNING AS HIGH PRESSURE BUILDS INTO THE REGION. UNDER
MOSTLY SUNNY SKIES SATURDAY AFTERNOON AND BREEZY NORTHERLY WINDS...
HIGHS SATURDAY AFTERNOON WILL RANGE FROM THE MID 30S NORTH TO MID
40S SOUTH. THESE COLD TEMPERATURES...COMBINED WITH NORTHERLY WINDS
BETWEEN 10-15 MPH AND GUSTING UP TO 20 MPH AT TIMES THROUGH MID-
AFTERNOON...WILL YIELD WIND CHILLS FROM THE MID 20S TO UPPER 30S
SATURDAY AFTERNOON. CLEAR SKIES AND LIGHT TO CALM WINDS ARE
EXPECTED SATURDAY NIGHT AS A SURFACE HIGH SHIFTS OVER THE REGION.
THIS WILL CAUSE OVERNIGHT LOWS TO PLUMMET INTO THE LOW TO MIDDLE 20S
AREAWIDE.
A BRIEF WARMING TREND WILL BEGIN ON SUNDAY AND CONTINUE INTO MONDAY
AS THE SURFACE HIGH SHIFTS EAST OF THE CWA...AND FLOW ACROSS THE
REGION BECOMES SOUTHERLY. STILL...AN OVERALL SEASONABLE DAY WILL BE
ON TAP SUNDAY AS HIGHS RANGE FROM THE MID 40S TO MID 50S UNDER SUNNY
SKIES. CLOUDS WILL INCREASE SUNDAY NIGHT INTO MONDAY MORNING AS
LOWS RANGE FROM THE MID 30S TO MID 40S. HIGHS MONDAY UNDER MOSTLY
CLOUDY SKIES WILL RANGE FROM THE MID 50S TO MIDDLE 60S...AND FALL
INTO THE UPPER 30S TO AROUND 50 MONDAY NIGHT.
THE BEFORE MENTIONED INCREASE IN CLOUD COVER SUNDAY NIGHT INTO
MONDAY MORNING IS IN RESPONSE TO AN UPPER LEVEL TROUGH SWINGING
ACROSS THE NATION`S MID-SECTION...AND MOISTURE INCREASING AHEAD OF
IT. THIS TROUGH WILL SEND ANOTHER COLD FRONT SLOWLY INTO AND
THROUGH THE FORECAST AREA MONDAY EVENING INTO TUESDAY. THIS WILL
ALSO BRING AN INCREASE IN RAIN CHANCES FROM MONDAY AFTERNOON THROUGH
AT LEAST TUESDAY. RAIN COULD LINGER ACROSS THE REGION INTO THE FIRST
PART OF WEDNESDAY...PRIMARILY ACROSS MY SOUTH...BUT ANOTHER
SHORTWAVE SWINGING OUT OF THE SOUTHERN PLAINS CURRENTLY LOOKS TO
CLEAR THE CWA OF RAIN BY WEDNESDAY EVENING. A RETURN TO CLEAR AND
QUIET WEATHER PREVAILS FOR THURSDAY. /19/
&&
.AVIATION...IFR TO SOME LIFR CEILINGS ARE PREVAILING EARLY THIS
MORNING AS LIGHT TO OCCASIONALLY MODERATE RAIN IS MOVING THROUGH THE
REGION. SOME LOCATIONS MAY SEE A MIX WITH LIGHT SNOW THROUGH
DAYBREAK ESPECIALLY WEST OF THE MS RIVER. RAIN IS STILL EXPECTED TO
TRANSITION TO LIGHT SNOW THROUGH THE MORNING HOURS AND END FROM WEST
TO EAST THROUGH TEH AFTERNOON/EVENING. AS RAIN/SNOW DEPARTS...
CEILINGS SHOULD GRADUALLY LIFT BACK TO MVFR. VERY GUSTY NORTH/NORTHWEST
WINDS ARE EXPECTED TO CONTINUE TODAY WITH SPEEDS AROUND 15KTS GUSTING
TO 20-25KTS ACROSS MOST OF THE AREA. HOWEVER...THE DELTA WILL HAVE
SPEEDS AROUND 25KTS GUSTING TO 30KTS. /28/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 36 27 41 25 / 82 5 0 0
MERIDIAN 43 27 41 24 / 73 11 1 0
VICKSBURG 34 29 40 26 / 80 5 0 0
HATTIESBURG 45 29 47 25 / 28 6 0 0
NATCHEZ 41 28 43 25 / 57 5 0 0
GREENVILLE 34 27 35 25 / 100 5 0 0
GREENWOOD 34 26 36 22 / 100 8 2 0
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR
MSZ029>033-037>039.
WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR MSZ018-019-034-035-
040-041-047.
WINTER STORM WARNING UNTIL 6 PM CST THIS EVENING FOR MSZ018-019-
025>028-034>036-040-041.
WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR MSZ042-
047.
LA...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR LAZ007>009-015-016-
023-025.
WINTER STORM WARNING UNTIL 6 PM CST THIS EVENING FOR LAZ007>009.
WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR LAZ015-
016.
AR...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR ARZ074-075.
WINTER STORM WARNING UNTIL 6 PM CST THIS EVENING FOR ARZ074-075.
&&
$$
EC/19/28
AREA FORECAST DISCUSSION
NWS ELKO NV
303 AM PST FRI JAN 22 2016
.SYNOPSIS...ANOTHER BATCH OF UNSETTLED WEATHER IS EXPECTED. A
PACIFIC LOW WILL BRING A MIX OF RAIN AND SNOW TO NORTHERN NEVADA
LATER TODAY AND SATURDAY. LINGERING FLURRIES POSSIBLE ON SUNDAY.
DRY CONDITIONS EXPECTED MONDAY THROUGH THURSDAY...WITH
TEMPERATURES NEAR NORMAL.
&&
.SHORT TERM...TODAY THROUGH SUNDAY. A FRONTAL BOUNDARY HAS MOVED
INTO THE WEST OFF THE PACIFIC AND THE ATTENDANT CLOUD SHIELD SPANS
FROM MANITOBA TO CENTRAL CALIFORNIA. THE TEMPERATURES OF THE CLOUD
TOPS ON THE LATEST IR IMAGE RANGE FROM -60C TO -35C OVER NEVADA.
CURRENTLY THE LKN CWA IS IN THE CALM BEFORE THE STORM. AS TIME
ELAPSES EXPECTING GUSTY CONDITIONS AND PRECIP TO FILTER INTO THE
REGION. THE HRRR HAS THE FIRST BAND ENTERING HUMBOLDT COUNTY
AROUND 22Z...WHICH IS ECHOED BY THE LATEST RUN OF THE NAM12. THE
PRECIPITATION ACTIVITY FOR ELKO COUNTY WILL BEGIN AFTER
MIDNIGHT...WITH THE 700 MB TEMPERATURES RANGING FROM 1C TO
-8C...WHICH IS NOT EXACTLY AN IMPRESSIVE COLD POOL FOR JANUARY.
EXPECTING A MIX OF RAIN AND SNOW WITH THIS STORM. DURING THIS
FORECAST PERIOD...THE NAEFS HAS PWS 2 STANDARD DEVIATIONS ABOVE
NORMAL MOST OF THE EVENT...PINGING INTO A RETURN INTERVAL OF ONE
YEAR. THE RUBIES AND THE JARBIDGE WILDERNESS AREA WILL GET YET
ANOTHER BLANKET OF FRESH SNOW...BUT THE VALLEY LOCATIONS WILL SEE
ANYWHERE FROM A TRACE TO 2 INCHES...AFTER THE INITIAL DOUSING OF
RAIN. REMNANT MOISTURE WILL LINGER INTO SUNDAY...BUT SIGNIFICANT
ACCUMULATIONS NOT EXPECTED.
.LONG TERM...SUNDAY NIGHT THROUGH NEXT FRIDAY. MODELS ARE IN VERY
GOOD AGREEMENT THROUGH MOST OF NEXT WEEK. HIGH PRESSURE WILL BE
BUILDING IN TO BRING A PROLONGED DRY SPELL.
DRY NORTHWEST FLOW WILL DOMINATE FROM SUNDAY NIGHT THROUGH ABOUT
THURSDAY. A FEW WEAK WAVES MOVING OVER THE TOP OF THE RIDGE WILL COOL
TEMPS OFF A BIT AT TIMES AND PRODUCE ENOUGH CLOUDS TO KEEPS THINGS
COOL IN THE DAY...A BIT WARMER AT NIGHT...AS THE LONG TERM
PROGRESSES. NEXT SYSTEM IS DUE LATE IN THE PERIOD...ABOUT THURSDAY
AFTERNOON INTO FRIDAY BUT ONLY MINIMAL POPS APPEAR AT THIS TIME.
&&
.AVIATION...VFR CONDITIONS CAN BE EXPECTED AT KWMC KEKO KELY AND
KTPH THROUGH FRIDAY EVENING...THEN DETERIORATION INCREASES THROUGH 12Z
AT ALL SITES...WITH KWMC AND KEKO THE WORST FOR WEAR. WEATHER WILL
START AT RAIN AND TURN TO RAIN/SNOW OR SNOW BY LATE AFTERNOON...
EVENING AT KELY AND KTPH. CIGS/VISBY WILL DROP TO MVFR AT KWMC AND
KEKO BUT LIKELY REMAIN VFR AT KTPH AND KELY. RUNWAY CONDITIONS...WET
OR SLUSHY UNTIL AROUND 03Z WHEN TEMPS COULD DROP BELOW
FREEZING...THEN ICY SPOTS.
&&
.LKN WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
97/98/98
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1035 AM EST FRI JAN 22 2016
.SYNOPSIS...
A POWERFUL STORM SYSTEM WILL TRACK NORTHEASTWARD OVER
THE CAROLINAS TODAY THROUGH TONIGHT... THEN PUSH SLOWLY OFF THE
MIDATLANTIC COAST SATURDAY THROUGH SATURDAY NIGHT. HIGH PRESSURE
WILL BUILD OVER THE AREA SUNDAY... THEN MOVE EAST AND OFFSHORE
MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1035 AM THURSDAY...
...WINTER STORM WARNING CONTINUES ACROSS CENTRAL NC...
...GUIDANCE/TRENDS INDICATE WARMER AIR IN THE MID LEVELS WILL LESSEN
SNOW ACCUMULATIONS BUT WILL STILL YIELD SIGNIFICANT FREEZING RAIN
ACCUMULATIONS...
...CONVECTION UPSTREAM ACROSS THE GULF POSSIBLY DISRUPTING MOISTURE
TRANSPORT WHICH COULD LOWER LIQUID EQUIVALENT AMOUNTS...
BASED ON LATEST OBSERVATIONS AND TRENDS...ITS BECOMING PRETTY
APPARENT THAT MOST OF CENTRAL NC WILL BE CONTENDING WITH A MORE ICY
SCENARIO OF FREEZING RAIN/SLEET MIX THIS MORNING AND INTO THE
AFTERNOON AS THE LAYER OF WARM AIR ALOFT WAS A BIT UNDERESTIMATED BY
THE MODEL GUIDANCE. THE GREATEST POTENTIAL FOR ICING IS EXPECTED
WEST OF HIGHWAY 1 WHERE HOURLY LIQUID QPF AMOUNTS AOA 0.05 IN/HR FOR
A MULTI-HOUR DURATION WOULD EASILY YIELD 0.25-0.50" WITHIN THIS
CORRIDOR. WILL LIKELY NEED TO RAISE ICE AMOUNTS INTO THE 0.10-0.25"
OVER THE EASTERN PIEDMONT...SANDHILLS AND CENTRAL/NORTHERN PORTIONS
OF THE COASTAL PLAIN AS WELL...WITH RAP/HRRR SFC WET BULBS
INDICATING A MUCH SLOWER NORTH-NORTHWESTWARD RETREAT THIS AFTERNOON.
THE ONE AREA THAT WE COULD STILL SEE SOME CONSIDERABLE SNOW AMOUNTS
WILL BE NORTH OF THE I-85 CORRIDOR...WHICH INCLUDES THE TRIAD AND
ROXBORO(PERSON COUNTY)...WHERE A NEAR-FREEZING ISOTHERMAL LAYER ATOP
A 7-8 DEGREE C COLD NOSE WILL SUPPORT MOSTLY SNOW/SLEET MIX.
SNOWFALL AMOUNTS OF 3 TO 6 INCHES.
AS SUBSTANTIAL WARMING ALOFT OF 3-7 DEGREES CELSIUS CENTERED AROUND
H8 CONTINUES TO SPREAD NORTH...STILL EXPECT PRECIP TO EVENTUALLY
SWITCH OVER TO ALL RAIN EAST OF THE TRIANGLE(US 1 CORRIDOR)THIS
AFTERNOON AND EVENING AND POSSIBLY A FREEZING RAIN/RAIN MIX AROUND
THE TRIANGLE.
PREVIOUS DISCUSSION...
RECENT GUIDANCE AND SURFACE OBSERVATIONS SUGGEST THAT SOME DOWNWARD
ADJUSTMENT TO THE ACCUMULATION TOTALS ARE LIKELY NEEDED.
HIGHER RESOLUTION GUIDANCE INCLUDING THE HI RES WINDOW ARW AND NMM
AND THE HRRR NOTE THE BACK EDGE OF THE SIGNIFICANT PRECIPITATION
LIKELY TO PROGRESS THROUGH CENTRAL NC MUCH MORE QUICKLY AND AHEAD
OF THE DRY SLOT. IN ADDITION...SURFACE OBSERVATIONS NOTE A
SIGNIFICANT PRESSURE FALL NORTH AND NORTHEAST OF THE SURFACE LOW
IN ALABAMA. THE HRRR PICKS UP ON THIS AND HIGHLIGHTS A SFC
PRESSURE FIELD INDICATIVE OF A POSSIBLE GRAVITY WAVE WITH
PRECIPITATION DECREASING BEHIND THIS FEATURE. HAVE ACCORDINGLY
LOWERED SNOW AND SLEET ACCUMULATIONS AROUND 10 TO 20 PERCENT OR
AROUND AN INCH OR TWO IN MOST LOCATIONS. OF NOTE...THE 07Z HRRR
BRINGS THE BACK EDGE OF THE STEADY PRECIPITATION TO RDU AT 21Z.
LATER SHIFTS WILL NEED TO MONITOR OBSERVATIONAL TRENDS AND ADJUST
FORECAST AS NEEDED. EVEN WITH TOTAL AMOUNTS DOWN A BIT...HAZARDOUS
TRAVEL CONDITIONS ARE EXPECTED.
IN ADDITION...LATEST GUIDANCE INCLUDING GFS AND SREF BUFR
SOUNDINGS WARM THE MID LEVELS MORE THAN PREVIOUS RUNS. THIS MORE
PROMINENT WARM NOSE MAKES MORE NORTHWEST PROGRESS AND SHOULD
RESULT IN LESS SNOW BUT A LARGER FRACTION OF SLEET AND FREEZING
RAIN.
GUIDANCE SUGGESTS THAT THE SIGNIFICANT PRECIPITATION WITH HOURLY
LIQUID EQUIVALENT RATES OF 0.05 TO 0.10 WILL EXPAND NORTHEAST
ACROSS THE RAH CWA THIS MORNING. THE PRECIPITATION WILL LIKELY BE
A LITTLE LIGHTER ACROSS THE EASTERN SANDHILLS AND SOUTHERN COASTAL
PLAIN THROUGH AT LEAST MID MORNING WITH THE STEADIER PRECIPITATION
ARRIVING LATE THIS MORNING AND AFTERNOON. INITIAL REPORTS INCLUDE
A FAIR AMOUNT OF SLEET AT THE ONSET...WITH TIME EARLY THIS MORNING
PRECIPITATION WILL BECOME MOSTLY SNOW IN THE TRIAD AND A MIX OF
SLEET AND SNOW IN THE TRIANGLE. FURTHER SOUTH...THE PRECIPITATION
HAS STARTED AS RAIN IN THE SOUTHERN TIER BUT COOLING FROM
EVAPORATION SHOULD RESULT IN A PERIOD OF FREEZING RAIN AND SLEET.
AS THE LOW AND MID LEVEL SOUTHERLY FLOW INCREASES...EXPECTED THE
PTYPE TO CHANGE TO RAIN IN THE COASTAL PLAIN AROUND OR JUST AFTER
MIDDAY. SNOW AND SLEET IN THE TRIANGLE WILL CHANGE TO SLEET AND
FREEZING RAIN IN THE EARLY AFTERNOON WHILE MOSTLY SNOW HOLDS ON
IN THE TRIAD. BY MID AFTERNOON MOSTLY FREEZING RAIN WILL BE
FALLING IN THE TRIANGLE WITH THE SNOW IN THE TRIAD MIXING WITH
SLEET. THE STEADIEST PRECIPITATION WILL LIKELY BE SHUTTING DOWN
FROM WEST TO EAST LATE THIS AFTERNOON AND EARLY THIS EVENING.
RESIDUAL MOISTURE AND SOME FORCING FOR ASCENT WILL CONTINUE THIS
EVENING AND OVERNIGHT. DEEP LAYER SATURATION WILL NOT EXTEND TO
ICE GLACIATION REGION WHICH WILL SHUT DOWN SNOW AND SLEET
OVERNIGHT BUT RESULT IN PERIODS OF FREEZING RAIN AND FREEZING
DRIZZLE.
STORM TOTAL SNOW AND SLEET ACCUMULATIONS IN THE TRIAD WILL RANGE
FROM 4 TO 8 INCHES IN THE TRIAD...LOCALLY MORE NORTH OF I-40 WITH
A TENTH OF AN INCH OF FREEZING RAIN. TO THE SOUTH AND EAST OF THE
IMMEDIATE TRIAD REGION...3 TO 5 INCHES OF SNOW AND SLEET ARE
EXPECTED ALONG WITH ICE ACCUMULATIONS AROUND A QUARTER OF AN INCH.
ACROSS MUCH OF THE TRIANGLE AND EASTERN PIEDMONT...SNOW AND SLEET
ACCUMULATION OF 2 TO 4 INCHES ARE EXPECTED WITH LOCALLY HEAVIER
AMOUNTS NORTH OF RALEIGH NEAR THE VIRGINIA BORDER. SNOW AND SLEET
ACCUMULATION ACROSS THE SOUTHERN PIEDMONT SHOULD TOTAL AN INCH OR
LESS. ICE ACCRUAL SHOULD TOTAL A QUARTER TO A THIRD OF AN INCH.
ACROSS THE EASTERN SANDHILLS AND COASTAL PLAIN...SNOW ACCUMULATION
OF UP TO AN INCH...ALONG WITH A TENTH TO TWO-TENTHS OF AN INCH OF
FREEZING RAIN ARE EXPECTED.
HIGH TEMPERATURES TODAY WILL RANGE INT THE UPPER 20S IN THE TRIAD
AREA TO TO THE UPPER 30S SOUTHEAST. TEMPERATURES WILL FALL ONLY
A COUPLE OF DEGREES TONIGHT. NORTHEAST WINDS WILL INCREASE THIS
MORNING REACHING 10- 20 MPH SUSTAINED WITH GUSTS TO AROUND 30 MPH.
WINDS WILL BACK AROUND TO NORTH THEN NORTHWEST TONIGHT. -BLAES
&&
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
AS OF 325 AM FRIDAY...
SAT/SAT NIGHT: WRAPAROUND PRECIP PRIMARILY IN THE FORM OF SNOW WILL
BE THE PRIMARY CONCERN HERE... WITH CONTINUED BRISK AND GUSTY WINDS
FROM THE NNW AND NW. MODELS ARE IN GOOD AGREEMENT WITH THE SURFACE
LOW OCCLUDING AS IT MOVES SLOWLY FROM JUST OFF NORFOLK ENE TO OFF
THE SOUTHERN NEW ENGLAND COAST BY SUN MORNING. ADDITIONAL QPF WILL
BE LIMITED BY THE WEAKER FORCING FOR ASCENT COMPARED TO TODAY`S DEEP
LAYER LIFT... BY SOME DRYING CONTRIBUTION FROM DOWNSLOPE LOW LEVEL
FLOW... AND BY THE THE MARGINAL AMOUNTS OF MOISTURE ABOVE -10C WHICH
BRINGS INTO QUESTION HOW MUCH ICE THERE WILL BE IN THE CLOUDS. OUR
BEST ESTIMATE IS ANOTHER ONE-HALF TO ONE-AND-A-HALF INCHES OF SNOW
MAINLY OVER THE NORTHERN PIEDMONT COUNTIES ON SAT... WITH THE
HIGHEST AMOUNTS AT THE VA BORDER. BASED ON THE AFOREMENTIONED
DOWNSLOPE FLOW AND THE LATEST FORECAST SOUNDINGS... EXPECT A BIT
QUICKER END TO PRECIP CHANCES FROM SW TO NE SAT EVENING AS COMPARED
TO THE PREVIOUS FORECAST... SUCH THAT LITTLE TO NO ADDITIONAL
ACCUMULATION IS ANTICIPATED AFTER 00Z SUNDAY. SKIES WILL GRADUALLY
CLEAR WEST TO EAST LATE. ANOMALOUSLY LOW THICKNESSES AND ABUNDANT
CLOUD COVER WILL HOLD SAT TEMPS DOWN TO LOWER-MID 30S. LOWS FROM THE
LOWER 20S WEST TO UPPER 20S EAST. DOWNWARD MOMENTUM TRANSPORT SHOULD
PUSH GUSTS PERIODICALLY UP TO 25-30 MPH... AND PERHAPS HIGHER IN THE
FAR NE CWA SAT AFTERNOON.
SUN THROUGH MON NIGHT: THE CLEARING TREND CONTINUES EARLY SUNDAY AS
THE STORM PULLS FURTHER OUT TO SEA AND BOTH SURFACE HIGH PRESSURE
AND MID LEVEL SHORTWAVE RIDGING BUILDING FROM THE WEST. EXPECT
MOSTLY SUNNY/MOSTLY CLEAR SKIES SUN/SUN NIGHT WITH CHILLY BUT SLOWLY
MODERATING TEMPS... PEAKING IN THE UPPER 30S (N) TO MID 40S (S) SUN
WITH LOWS IN THE UPPER TEENS TO MID 20S SUN NIGHT. THE RIDGE AXIS
FROM THE SURFACE UP THROUGH THE MID LEVELS SHIFTS OFF THE COAST MON
AND THE ENSUING ONSET OF WARM AIR ADVECTION (AHEAD OF THE NEXT STORM
SYSTEM) WILL LEAD TO INCREASING HIGH CLOUDS FROM WEST TO EAST...
PARTICULARLY MON NIGHT. TEMPS SHOULD RECOVER BACK CLOSER TO
NORMAL... WITH HIGHS FROM THE MID 40S TO LOWER 50S... AND MON NIGHT
LOWS IN THE MID-UPPER 30S. -GIH
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 205 AM FRIDAY...
SPLIT FLOW ALOFT WILL BECOME INCREASINGLY SO EARLY TO MID NEXT WEEK
OVER THE EASTERN NORTH PACIFIC AND WESTERN NOAM...AS NORTHERN STREAM
RIDGING THERE BECOMES INCREASINGLY AMPLIFIED. DOWNSTREAM...A
CORRESPONDING INCREASINGLY AMPLIFIED POSITIVELY-TILTED TROUGH ALOFT
WILL PROGRESS EAST...WITH SOME DEGREE OF PHASING POSSIBLE BETWEEN
THE STREAMS AS THE TROUGH APPROACHES THE EAST COAST. AN ASSOCIATED
SURFACE FRONTAL ZONE WILL ACCOMPANY THE APPROACHING TROUGH...WITH A
MODEL CONSENSUS TIMING OF THE PASSAGE OF THE FRONT -AND ASSOCIATED
BAND OF SHOWERS- LATE TUE OR TUE NIGHT.
THERE CONTINUES TO BE A SIGNAL IN NWP GUIDANCE OF CYCLOGENESIS ALONG
THE TAIL END OF THAT FRONT...FROM THE EASTERN GULF OF MEXICO TO
OFFSHORE THE SOUTHEAST US COAST...THOUGH MODEL SPREAD IN THE
EXISTENCE AND/OR TRACK OF THE LOW...AND ASSOCIATED FORECAST
UNCERTAINTY...IS VERY LARGE. WILL MAINTAIN RELATIVE CONTINUITY WITH
THE PREVIOUS RAH OFFICIAL FORECAST...WITH A CONTINUED SLIGHT-LOW
CHANCE OF PRECIPITATION TUE NIGHT-THU...WITH POST-FRONTAL DEEP-LAYER
COOLING SUPPORTIVE OF A MIX OR CHANGE TO SNOW -CONDITIONAL UPON
PRECIPITATION INDEED OCCURRING -OVER CLIMATOLOGICALLY-FAVORED AREAS
OF THE PIEDMONT...WHEN SURFACE TEMPERATURES ARE COLDEST DURING THE
MORNING AND NIGHTTIME HOURS WED.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AS OF 700 AM FRIDAY...
AVIATION CONDITIONS WILL CONTINUE TO DETERIORATE SW-NE ACROSS
CENTRAL NC THIS MORNING AS A MAJOR WINTER STORM BEGINS TO AFFECT THE
REGION. CEILINGS WILL CONTINUE TO LOWER...BECOMING IFR ACROSS THE
AREA PRIOR TO NOON. AREAS OF SNOW AND/OR SLEET WILL PERSIST ACROSS
THE NORTHERN PIEDMONT WHILE AREAS OF FREEZING RAIN AND SLEET WILL
OCCUR ACROSS THE SOUTH AND EAST SECTIONS.
CONDITIONS WILL DETERIORATE FURTHER THIS AFTERNOON AS WIDESPREAD IFR
CONDITIONS WILL PREVAIL. WIDESPREAD SNOW MIXED WITH SLEET WILL
PERSIST IN VICINITY OF KGSO AND KINT WHILE FREEZING RAIN WILL BECOME
THE DOMINATE P-TYPE IN VICINITY OF KRDU AND KRWI. KFAY WILL
GRADUALLY TRANSITION FROM A PERIOD OF SLEET AND FREEZING RAIN THIS
MORNING TO A COLD RAIN THIS AFTERNOON. THE TRANSITION TO A COLD RAIN
MAY OCCUR AT KRWI BY LATE AFTERNOON. SFC WINDS WILL INCREASE OUT OF
THE NORTHEAST WITH GUSTS 25-35 MPH HIGHLY PROBABLE...ESPECIALLY IN
VICINITY OF KFAY AND KRWI.
THE ADVERSE AVIATION CONDITIONS WITH LOW CEILINGS AND WINTRY MIX
WILL PERSIST TONIGHT INTO SATURDAY. CONDITIONS WILL BEGIN TO SLOWLY
IMPROVE SATURDAY NIGHT WITH VFR CONDITIONS HIGHLY PROBABLE SUNDAY
AND MONDAY. A LOW PRESSURE SYSTEM APPROACHING FROM THE WEST WILL
BRING THE NEXT THREAT FOR ADVERSE AVIATION CONDITIONS ON
TUESDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR NCZ028-
043-078-089.
WINTER STORM WARNING UNTIL 6 PM EST SATURDAY FOR NCZ007>011-
021>026-038>041-073>077-083-084.
WINTER STORM WARNING UNTIL 6 PM EST THIS EVENING FOR NCZ027-
042-085-086-088.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...CBL/BLAES
SHORT TERM...HARTFIELD
LONG TERM...MWS
AVIATION...WSS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
700 AM EST FRI JAN 22 2016
.SYNOPSIS...
A POWERFUL STORM SYSTEM WILL TRACK NORTHEASTWARD OVER
THE CAROLINAS TODAY THROUGH TONIGHT... THEN PUSH SLOWLY OFF THE
MIDATLANTIC COAST SATURDAY THROUGH SATURDAY NIGHT. HIGH PRESSURE
WILL BUILD OVER THE AREA SUNDAY... THEN MOVE EAST AND OFFSHORE
MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 415 AM THURSDAY...
...WINTER STORM CONDITIONS WILL OVERSPREAD CENTRAL NC THIS
MORNING...
...LATEST GUIDANCE SUGGESTS AN EARLIER CUT OFF TO SIGNIFICANT
PRECIPITATION RATES THIS AFTN/EARLY EVE AND WE HAVE DECREASED
SNOW AND ICE ACCUMULATIONS BY ABOUT 20 PERCENT...
...GUIDANCE IS ALSO WARMER IN THE MID LEVELS SUGGESTING LOWER
SNOW ACCUMULATIONS AND MORE SLEET AND FREEZING RAIN...
LATEST SURFACE ANALYSIS SHOWS THE WINTER STORM DEEPENING ACROSS
ALABAMA THIS MORNING WITH PRECIPITATION SPREADING NORTHEAST ACROSS
THE CAROLINAS AND INTO THE WESTERN PARTS OF THE RAH CWA. LIGHT
SNOW BEGAN AT 4AM IN GREENSBORO AND LEXINGTON AND LIGHT
FREEZING RAIN AND RAIN AT ASHEBORO...ROCKINGHAM AND WADESBORO.
RECENT GUIDANCE AND SURFACE OBSERVATIONS SUGGEST THAT SOME
DOWNWARD ADJUSTMENT TO THE ACCUMULATION TOTALS ARE LIKELY NEEDED.
HIGHER RESOLUTION GUIDANCE INCLUDING THE HI RES WINDOW ARW AND NMM
AND THE HRRR NOTE THE BACK EDGE OF THE SIGNIFICANT PRECIPITATION
LIKELY TO PROGRESS THROUGH CENTRAL NC MUCH MORE QUICKLY AND AHEAD
OF THE DRY SLOT. IN ADDITION...SURFACE OBSERVATIONS NOTE A
SIGNIFICANT PRESSURE FALL NORTH AND NORTHEAST OF THE SURFACE LOW
IN ALABAMA. THE HRRR PICKS UP ON THIS AND HIGHLIGHTS A SFC
PRESSURE FIELD INDICATIVE OF A POSSIBLE GRAVITY WAVE WITH
PRECIPITATION DECREASING BEHIND THIS FEATURE. HAVE ACCORDINGLY
LOWERED SNOW AND SLEET ACCUMULATIONS AROUND 10 TO 20 PERCENT OR
AROUND AN INCH OR TWO IN MOST LOCATIONS. OF NOTE...THE 07Z HRRR
BRINGS THE BACK EDGE OF THE STEADY PRECIPITATION TO RDU AT 21Z.
LATER SHIFTS WILL NEED TO MONITOR OBSERVATIONAL TRENDS AND ADJUST
FORECAST AS NEEDED. EVEN WITH TOTAL AMOUNTS DOWN A BIT...HAZARDOUS
TRAVEL CONDITIONS ARE EXPECTED.
IN ADDITION...LATEST GUIDANCE INCLUDING GFS AND SREF BUFR
SOUNDINGS WARM THE MID LEVELS MORE THAN PREVIOUS RUNS. THIS MORE
PROMINENT WARM NOSE MAKES MORE NORTHWEST PROGRESS AND SHOULD
RESULT IN LESS SNOW BUT A LARGER FRACTION OF SLEET AND FREEZING
RAIN.
GUIDANCE SUGGESTS THAT THE SIGNIFICANT PRECIPITATION WITH HOURLY
LIQUID EQUIVALENT RATES OF 0.05 TO 0.10 WILL EXPAND NORTHEAST
ACROSS THE RAH CWA THIS MORNING. THE PRECIPITATION WILL LIKELY BE
A LITTLE LIGHTER ACROSS THE EASTERN SANDHILLS AND SOUTHERN COASTAL
PLAIN THROUGH AT LEAST MID MORNING WITH THE STEADIER PRECIPITATION
ARRIVING LATE THIS MORNING AND AFTERNOON. INITIAL REPORTS INCLUDE
A FAIR AMOUNT OF SLEET AT THE ONSET...WITH TIME EARLY THIS MORNING
PRECIPITATION WILL BECOME MOSTLY SNOW IN THE TRIAD AND A MIX OF
SLEET AND SNOW IN THE TRIANGLE. FURTHER SOUTH...THE PRECIPITATION
HAS STARTED AS RAIN IN THE SOUTHERN TIER BUT COOLING FROM
EVAPORATION SHOULD RESULT IN A PERIOD OF FREEZING RAIN AND SLEET.
AS THE LOW AND MID LEVEL SOUTHERLY FLOW INCREASES...EXPECTED THE
PTYPE TO CHANGE TO RAIN IN THE COASTAL PLAIN AROUND OR JUST AFTER
MIDDAY. SNOW AND SLEET IN THE TRIANGLE WILL CHANGE TO SLEET AND
FREEZING RAIN IN THE EARLY AFTERNOON WHILE MOSTLY SNOW HOLDS ON
IN THE TRIAD. BY MID AFTERNOON MOSTLY FREEZING RAIN WILL BE
FALLING IN THE TRIANGLE WITH THE SNOW IN THE TRIAD MIXING WITH
SLEET. THE STEADIEST PRECIPITATION WILL LIKELY BE SHUTTING DOWN
FROM WEST TO EAST LATE THIS AFTERNOON AND EARLY THIS EVENING.
RESIDUAL MOISTURE AND SOME FORCING FOR ASCENT WILL CONTINUE THIS
EVENING AND OVERNIGHT. DEEP LAYER SATURATION WILL NOT EXTEND TO
ICE GLACIATION REGION WHICH WILL SHUT DOWN SNOW AND SLEET
OVERNIGHT BUT RESULT IN PERIODS OF FREEZING RAIN AND FREEZING
DRIZZLE.
STORM TOTAL SNOW AND SLEET ACCUMULATIONS IN THE TRIAD WILL RANGE
FROM 4 TO 8 INCHES IN THE TRIAD...LOCALLY MORE NORTH OF I-40 WITH
A TENTH OF AN INCH OF FREEZING RAIN. TO THE SOUTH AND EAST OF THE
IMMEDIATE TRIAD REGION...3 TO 5 INCHES OF SNOW AND SLEET ARE
EXPECTED ALONG WITH ICE ACCUMULATIONS AROUND A QUARTER OF AN INCH.
ACROSS MUCH OF THE TRIANGLE AND EASTERN PIEDMONT...SNOW AND SLEET
ACCUMULATION OF 2 TO 4 INCHES ARE EXPECTED WITH LOCALLY HEAVIER
AMOUNTS NORTH OF RALEIGH NEAR THE VIRGINIA BORDER. SNOW AND SLEET
ACCUMULATION ACROSS THE SOUTHERN PIEDMONT SHOULD TOTAL AN INCH OR
LESS. ICE ACCRUAL SHOULD TOTAL A QUARTER TO A THIRD OF AN INCH.
ACROSS THE EASTERN SANDHILLS AND COASTAL PLAIN...SNOW ACCUMULATION
OF UP TO AN INCH...ALONG WITH A TENTH TO TWO-TENTHS OF AN INCH OF
FREEZING RAIN ARE EXPECTED.
HIGH TEMPERATURES TODAY WILL RANGE INT THE UPPER 20S IN THE TRIAD
AREA TO TO THE UPPER 30S SOUTHEAST. TEMPERATURES WILL FALL ONLY
A COUPLE OF DEGREES TONIGHT. NORTHEAST WINDS WILL INCREASE THIS
MORNING REACHING 10- 20 MPH SUSTAINED WITH GUSTS TO AROUND 30 MPH.
WINDS WILL BACK AROUND TO NORTH THEN NORTHWEST TONIGHT. -BLAES
&&
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
AS OF 325 AM FRIDAY...
SAT/SAT NIGHT: WRAPAROUND PRECIP PRIMARILY IN THE FORM OF SNOW WILL
BE THE PRIMARY CONCERN HERE... WITH CONTINUED BRISK AND GUSTY WINDS
FROM THE NNW AND NW. MODELS ARE IN GOOD AGREEMENT WITH THE SURFACE
LOW OCCLUDING AS IT MOVES SLOWLY FROM JUST OFF NORFOLK ENE TO OFF
THE SOUTHERN NEW ENGLAND COAST BY SUN MORNING. ADDITIONAL QPF WILL
BE LIMITED BY THE WEAKER FORCING FOR ASCENT COMPARED TO TODAY`S DEEP
LAYER LIFT... BY SOME DRYING CONTRIBUTION FROM DOWNSLOPE LOW LEVEL
FLOW... AND BY THE THE MARGINAL AMOUNTS OF MOISTURE ABOVE -10C WHICH
BRINGS INTO QUESTION HOW MUCH ICE THERE WILL BE IN THE CLOUDS. OUR
BEST ESTIMATE IS ANOTHER ONE-HALF TO ONE-AND-A-HALF INCHES OF SNOW
MAINLY OVER THE NORTHERN PIEDMONT COUNTIES ON SAT... WITH THE
HIGHEST AMOUNTS AT THE VA BORDER. BASED ON THE AFOREMENTIONED
DOWNSLOPE FLOW AND THE LATEST FORECAST SOUNDINGS... EXPECT A BIT
QUICKER END TO PRECIP CHANCES FROM SW TO NE SAT EVENING AS COMPARED
TO THE PREVIOUS FORECAST... SUCH THAT LITTLE TO NO ADDITIONAL
ACCUMULATION IS ANTICIPATED AFTER 00Z SUNDAY. SKIES WILL GRADUALLY
CLEAR WEST TO EAST LATE. ANOMALOUSLY LOW THICKNESSES AND ABUNDANT
CLOUD COVER WILL HOLD SAT TEMPS DOWN TO LOWER-MID 30S. LOWS FROM THE
LOWER 20S WEST TO UPPER 20S EAST. DOWNWARD MOMENTUM TRANSPORT SHOULD
PUSH GUSTS PERIODICALLY UP TO 25-30 MPH... AND PERHAPS HIGHER IN THE
FAR NE CWA SAT AFTERNOON.
SUN THROUGH MON NIGHT: THE CLEARING TREND CONTINUES EARLY SUNDAY AS
THE STORM PULLS FURTHER OUT TO SEA AND BOTH SURFACE HIGH PRESSURE
AND MID LEVEL SHORTWAVE RIDGING BUILDING FROM THE WEST. EXPECT
MOSTLY SUNNY/MOSTLY CLEAR SKIES SUN/SUN NIGHT WITH CHILLY BUT SLOWLY
MODERATING TEMPS... PEAKING IN THE UPPER 30S (N) TO MID 40S (S) SUN
WITH LOWS IN THE UPPER TEENS TO MID 20S SUN NIGHT. THE RIDGE AXIS
FROM THE SURFACE UP THROUGH THE MID LEVELS SHIFTS OFF THE COAST MON
AND THE ENSUING ONSET OF WARM AIR ADVECTION (AHEAD OF THE NEXT STORM
SYSTEM) WILL LEAD TO INCREASING HIGH CLOUDS FROM WEST TO EAST...
PARTICULARLY MON NIGHT. TEMPS SHOULD RECOVER BACK CLOSER TO
NORMAL... WITH HIGHS FROM THE MID 40S TO LOWER 50S... AND MON NIGHT
LOWS IN THE MID-UPPER 30S. -GIH
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 205 AM FRIDAY...
SPLIT FLOW ALOFT WILL BECOME INCREASINGLY SO EARLY TO MID NEXT WEEK
OVER THE EASTERN NORTH PACIFIC AND WESTERN NOAM...AS NORTHERN STREAM
RIDGING THERE BECOMES INCREASINGLY AMPLIFIED. DOWNSTREAM...A
CORRESPONDING INCREASINGLY AMPLIFIED POSITIVELY-TILTED TROUGH ALOFT
WILL PROGRESS EAST...WITH SOME DEGREE OF PHASING POSSIBLE BETWEEN
THE STREAMS AS THE TROUGH APPROACHES THE EAST COAST. AN ASSOCIATED
SURFACE FRONTAL ZONE WILL ACCOMPANY THE APPROACHING TROUGH...WITH A
MODEL CONSENSUS TIMING OF THE PASSAGE OF THE FRONT -AND ASSOCIATED
BAND OF SHOWERS- LATE TUE OR TUE NIGHT.
THERE CONTINUES TO BE A SIGNAL IN NWP GUIDANCE OF CYCLOGENESIS ALONG
THE TAIL END OF THAT FRONT...FROM THE EASTERN GULF OF MEXICO TO
OFFSHORE THE SOUTHEAST US COAST...THOUGH MODEL SPREAD IN THE
EXISTENCE AND/OR TRACK OF THE LOW...AND ASSOCIATED FORECAST
UNCERTAINTY...IS VERY LARGE. WILL MAINTAIN RELATIVE CONTINUITY WITH
THE PREVIOUS RAH OFFICIAL FORECAST...WITH A CONTINUED SLIGHT-LOW
CHANCE OF PRECIPITATION TUE NIGHT-THU...WITH POST-FRONTAL DEEP-LAYER
COOLING SUPPORTIVE OF A MIX OR CHANGE TO SNOW -CONDITIONAL UPON
PRECIPITATION INDEED OCCURRING -OVER CLIMATOLOGICALLY-FAVORED AREAS
OF THE PIEDMONT...WHEN SURFACE TEMPERATURES ARE COLDEST DURING THE
MORNING AND NIGHTTIME HOURS WED.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AS OF 700 AM FRIDAY...
AVIATION CONDITIONS WILL CONTINUE TO DETERIORATE SW-NE ACROSS
CENTRAL NC THIS MORNING AS A MAJOR WINTER STORM BEGINS TO AFFECT THE
REGION. CEILINGS WILL CONTINUE TO LOWER...BECOMING IFR ACROSS THE
AREA PRIOR TO NOON. AREAS OF SNOW AND/OR SLEET WILL PERSIST ACROSS
THE NORTHERN PIEDMONT WHILE AREAS OF FREEZING RAIN AND SLEET WILL
OCCUR ACROSS THE SOUTH AND EAST SECTIONS.
CONDITIONS WILL DETERIORATE FURTHER THIS AFTERNOON AS WIDESPREAD IFR
CONDITIONS WILL PREVAIL. WIDESPREAD SNOW MIXED WITH SLEET WILL
PERSIST IN VICINITY OF KGSO AND KINT WHILE FREEZING RAIN WILL BECOME
THE DOMINATE P-TYPE IN VICINITY OF KRDU AND KRWI. KFAY WILL
GRADUALLY TRANSITION FROM A PERIOD OF SLEET AND FREEZING RAIN THIS
MORNING TO A COLD RAIN THIS AFTERNOON. THE TRANSITION TO A COLD RAIN
MAY OCCUR AT KRWI BY LATE AFTERNOON. SFC WINDS WILL INCREASE OUT OF
THE NORTHEAST WITH GUSTS 25-35 MPH HIGHLY PROBABLE...ESPECIALLY IN
VICINITY OF KFAY AND KRWI.
THE ADVERSE AVIATION CONDITIONS WITH LOW CEILINGS AND WINTRY MIX
WILL PERSIST TONIGHT INTO SATURDAY. CONDITIONS WILL BEGIN TO SLOWLY
IMPROVE SATURDAY NIGHT WITH VFR CONDITIONS HIGHLY PROBABLE SUNDAY
AND MONDAY. A LOW PRESSURE SYSTEM APPROACHING FROM THE WEST WILL
BRING THE NEXT THREAT FOR ADVERSE AVIATION CONDITIONS ON
TUESDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR NCZ028-
043-078-089.
WINTER STORM WARNING UNTIL 6 PM EST SATURDAY FOR NCZ007>011-
021>026-038>041-073>077-083-084.
WINTER STORM WARNING UNTIL 6 PM EST THIS EVENING FOR NCZ027-
042-085-086-088.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...BLAES
SHORT TERM...HARTFIELD
LONG TERM...MWS
AVIATION...WSS
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
915 AM EST FRI JAN 22 2016
.SYNOPSIS...
LOW PRESSURE WILL MOVE FROM THE LOWER GULF COAST INTO THE
TENNESSEE VALLEY ON FRIDAY...THEN WEAKEN IN THE APPALACHIANS
FRIDAY NIGHT AS ANOTHER LOW DEVELOPS ALONG THE MID ATLANTIC COAST.
HIGH PRESSURE WILL GRADUALLY BUILD IN DURING THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
BETTER RETURNS ON RADAR ARE INCHING VERY SLOWLY NORTHWARD. THE
BEST RETURNS ARE STILL SOUTH OF OUR FA...BUT WE MAY BE STARTING TO
SEE SOME SNOW STARTING TO REACH THE GROUND ACROSS OUR FAR SOUTHERN
AREAS. THE LAST FEW RUNS OF THE RAP ARE STILL A LITTLE FARTHER
NORTH WITH THE PCPN PUSH BUT THIS LINES UP FAIRLY CLOSE WITH OUR
CURRENT FORECAST. TIMING AND AMOUNTS STILL SEEM REASONABLE SO NO
MAJORS CHANGES ARE PLANNED TO THE FORECAST AT THIS POINT.
...PREVIOUS DISCUSSION...
UPR LVL CLOSED LOW OVER THE LOWER GULF COAST STATES THIS MORNING
WILL PIVOT EAST/NORTHEAST TOWARD THE TENNESSEE RIVER VALLEY BY
THIS EVENING. ITS ASSOCIATED SFC LOW PRESSURE WILL DO THE SAME
WITH AN INVERTED TROUGH POKING NORTHEAST INTO OHIO VALLEY.
THIS WEATHER SYSTEM WILL PIVOT AN EAST/WEST FRONTOGENETIC AREA
NORTHWARD TOWARD THE OHIO RIVER VALLEY. THE RESULTING SIGNIFICANT
VERTICAL MOTION IS STILL EXPECTED TO BE THE HIGHEST ALONG AND
SOUTH OF THE OHIO RIVER...WITH QUICKLY DIMINISHING FORCING AS ONE
HEADS FARTHER NORTH/NORTHWEST. AS IS TYPICAL WITH
FRONTOGENESIS/DEFORMATION...THERE WILL BE A SHARP CUT OFF TO THE
PCPN...AND THAT SO HAPPENS TO BE OVER THE FORECAST AREA. IN TERMS
OF PCPN TYPE...IT IS EXPECTED TO BE ALL SNOW AS SOUNDINGS/THERMAL
FIELDS INDICATE IT WILL REMAIN SUFFICIENTLY COLD. THE BIG QUESTION
WILL BE WHERE DOES THE PCPN REACH ITS FARTHEST NORTHWARD EXTEND
BEFORE IT BEGINS TO PIVOT EAST AS A COASTAL LOW TAKES OVER ALONG
THE MID ATLANTIC REGION TONIGHT. THE PREVIOUS FORECAST HAS HANDLED
THIS QUITE WELL FOR THE MOST PART. THE BIGGEST CHANGE WITH THE 00Z
RUNS COMPARED TO THE PREVIOUS FORECAST IS THAT THE MODELS...FOR
THE MOST PART...HAVE EVER SO SLIGHTLY SHIFTED THE
DEFORMATION/SHARP CUT OFF A LITTLE FARTHER NORTHWEST. AS
SUCH...STORM TOTAL QPF AND SUBSEQUENT STORM TOTAL SNOW HAD TO BE
ADJUSTED A LITTLE MORE NORTHWEST. USING A SNOW TO LIQUID RATIO
RANGING FROM 13:1 TO 15:1...THIS HAS PROMPTED TO ADD A FEW
COUNTIES TO THE PREVIOUS WINTER WEATHER ADVISORY
(RIPLEY...DEARBORN...AND WARREN). IN A NUTSHELL...SIGNIFICANT SNOW
IS EXPECTED OVER OUR SOUTHERN/SOUTHEASTERN FORECAST AREA WHERE 8
TO 14 INCHES OF SNOW COULD ACCUMULATE BY THE TIME IT TAPERS OFF BY
SATURDAY MORNING. THE HEAVIEST SNOW IN THESE AREAS IS EXPECTED
THIS AFTERNOON INTO THIS EVENING WHERE VERTICAL MOTION WILL BE
MAXIMIZE AS IT EXTENDS INTO THE FAVORABLE DENDRITIC GROWTH
ZONE...RESULTING IN PERIODS OF HEAVY SNOW. AS ONE HEADS FARTHER
NORTH/NORTHWEST...ACCUMULATIONS WILL SHOW A DOWNWARD TREND WITH
THE BUFFER ZONE (THE WINTER WEATHER ADVISORY) POSSIBLY SEEING 1 TO
3 INCHES. AGAIN...PREVIOUS WINTER STORM WARNINGS ARE STILL IN
EFFECT AND NO ADDITIONAL COUNTIES WERE ADDED TO THE WARNINGS.
SNOW WILL DECREASE IN INTENSITY TOWARD MIDNIGHT TONIGHT...WITH A
GRADUAL SHIFT TO THE WIDESPREAD SNOW FROM WEST TO EAST TOWARD
SATURDAY MORNING.
IN ADDITION TO THE SNOW THROUGH THE PERIOD....WINDS WILL INCREASE
FROM THE NORTHEAST IN THE 10 TO 20 MPH RANGE WITH GUSTS UP TO 30
MPH POSSIBLE.
TEMPERATURES TODAY WILL NOT WARM UP ALL THAT MUCH DUE TO OVERCAST
CONDITIONS...NORTHEAST WINDS...AND OVERSPREADING PCPN. HIGHS WILL
BE IN THE MID AND UPPER 20S. LOWS TONIGHT WILL RANGE FROM THE
LOWER TO MID 20S.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
MAJOR COASTAL STORM OFF THE MID ATLANTIC COAST WILL PUSH OUT TO
SEA ON SATURDAY. AS THIS OCCURS...ANY LINGERING SNOW WILL TAPER
OFF AND END BY AFTERNOON ACROSS THE EASTERN/SOUTHEASTERN ZONES. IT
SHOULD REMAIN FAIRLY CLOUDY AS LOW LEVEL MOISTURE LINGERS ACROSS
THE REGION. HIGHS WILL GENERALLY BE IN THE UPPER 20S.
FOR SATURDAY NIGHT...SURFACE HIGH PRESSURE IS FORECAST TO BUILD
INTO THE OHIO VALLEY. AT THE SAME TIME...SKIES ARE EXPECTED TO
BECOME MOSTLY CLEAR. IN LOCATIONS THAT SEE A DEEP SNOW PACK...THE
STAGE WILL BE SET FOR TEMPERATURES TO DROP MORE THAN WHAT SOME OF
THE CURRENT MODELS (ESPECIALLY MOS GUIDANCE) OR FORECASTING. HAVE
CONTINUED WITH THE PREVIOUS FORECAST WHICH IS TO ALLOW LOWS TO
DROP INTO THE SINGLE DIGITS WHERE SNOW WILL BE THE DEEPEST IN OUR
SOUTH/SOUTHEAST WITH MID TEENS AS ONE MOVES TOWARDS WEST CENTRAL
OHIO. IT IS CERTAINLY NOT OUT OF THE QUESTION FOR A FEW LOCATIONS
TO DIP SLIGHTLY BELOW ZERO...BUT WE WILL TAKE A CLOSER LOOK AT
THIS POSSIBILITY ONCE THE WINTER STORM IS OVER AND AMOUNTS ARE
VERIFIED.
FOR SUNDAY...HIGH PRESSURE WILL MOVE OFF TO THE EAST. RETURN FLOW
AND WAA IS EXPECTED. HOWEVER...MID AND HIGH LEVEL CLOUDS SPILLING
IN FROM THE NORTHWEST...COMBINED WITH ALBEDO FROM RECENT
SNOW...MAY KEEP TEMPERATURES COOLER IN THE EAST/SOUTHEAST THAN IF
THE GROUND WERE BARE. AS SUCH...HAVE HIGHS AROUND 30 IN THE
SOUTHEAST WITH LOWER TO POSSIBLE MID 30S POSSIBLE FOR THE
WEST/NORTHWEST.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
A SYSTEM WILL APPROACH THE AREA ON MONDAY. PRECIPITATION WILL
START OUT AS RAIN ACROSS MOST LOCATIONS. PRECIPITATION WILL START
TO CHANGE OVER TO SNOW MONDAY NIGHT AS THE COLD FRONT WORKS INTO
THE REGION AND COLDER AIR FILTERS IN. SNOW SHOWERS WILL TAPER OFF
DURING THE DAY ON TUESDAY.
A COUPLE OF ADDITIONAL DISTURBANCES WILL MOVE THROUGH ON WEDNESDAY
AND THURSDAY. PRECIPITATION WILL GENERALLY BE IN THE FORM OF SNOW
SHOWERS WITH THESE EVENTS.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS WILL CONTINUE THROUGH THE FIRST SEVERAL HOURS OF
THE FORECAST PERIOD...WITH GRADUALLY LOWERING CLOUDS...AND
INCREASING NORTHEASTERLY WINDS. BY AFTERNOON...THE IMPACTS FROM A
SIGNIFICANT WINTER STORM WILL BEGIN TO SPREAD NORTH TOWARD THE
REGION. IN AGREEMENT WITH THE PREVIOUS FORECAST...THE KCVG/KLUK
AIRPORTS HAVE THE GREATEST CHANCE TO EXPERIENCE ACCUMULATING
SNOWFALL AND A LENGTHY PERIOD OF REDUCED AVIATION CONDITIONS. IFR
VISIBILITIES ARE A NEAR CERTAINTY...ESPECIALLY BETWEEN 22Z-03Z.
SNOW IS ALSO EXPECTED FOR KILN/KCMH/KLCK. ALTHOUGH THE DURATION
AND INTENSITY OF THE SNOW REMAINS IN QUESTION...IT NOW APPEARS
THAT ALL THREE TAF SITES WILL EXPERIENCE AT LEAST A BRIEF PERIOD
OF IFR CONDITIONS. IT STILL APPEARS LIKELY THAT KDAY WILL REMAIN
DRY...BUT SOME VERY LIGHT SNOW MAY BE POSSIBLE DURING THE LATE
AFTERNOON AND EARLY EVENING.
BY LATE FRIDAY EVENING...AS WINDS SHIFT TO THE
NORTH-NORTHEAST...MVFR CEILINGS ARE LIKELY TO DEVELOP AT ALL OF
THE TAF SITES. THESE CEILINGS WILL PROBABLY CONTINUE THROUGH THE
END OF THE FORECAST PERIOD...BUT THERE MAY BE SOME BREAKS NEAR 12Z
SATURDAY MORNING. WINDS WILL ALSO BE GUSTY OVERNIGHT...POSSIBLY UP
TO 30 KNOTS.
NOTE THAT ANY ADDITIONAL CHANGES TO THE FORECAST TRACK OF THIS
WINTER STORM COULD SPREAD MORE OR LESS SNOW INTO THE
REGION...WHICH WOULD HAVE IMPACTS ON VISIBILITY AND CEILING
FORECASTS.
OUTLOOK...MVFR CEILINGS MAY CONTINUE INTO SATURDAY. MVFR/IFR
CONDITIONS ARE POSSIBLE AGAIN MONDAY NIGHT INTO TUESDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 7 AM EST
SATURDAY FOR OHZ063>065-071-072-077.
WINTER STORM WARNING UNTIL 7 AM EST SATURDAY FOR OHZ079-082.
WINTER STORM WARNING FROM 1 PM THIS AFTERNOON TO 7 AM EST
SATURDAY FOR OHZ073-074-078-080.
WINTER STORM WARNING UNTIL NOON EST SATURDAY FOR OHZ081-088.
KY...WINTER STORM WARNING UNTIL 7 AM EST SATURDAY FOR KYZ094>097.
WINTER STORM WARNING FROM 1 PM THIS AFTERNOON TO 7 AM EST
SATURDAY FOR KYZ089>093.
WINTER STORM WARNING UNTIL NOON EST SATURDAY FOR KYZ098>100.
IN...WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 7 AM EST
SATURDAY FOR INZ073>075-080.
&&
$$
SYNOPSIS...HICKMAN/JGL
NEAR TERM...JGL
SHORT TERM...HICKMAN
LONG TERM...NOVAK
AVIATION...HATZOS
AREA FORECAST DISCUSSION
NWS NORMAN OK
538 AM CST FRI JAN 22 2016
.DISCUSSION...
AVIATION DISCUSSION FOR THE 12Z TAFS IS BELOW.
&&
.AVIATION...
MVFR CEILINGS WILL AFFECT MOST SITES THROUGH AT LEAST 17Z BEFORE
DISSIPATING 17-03Z. THE EXACT TIMING OF DISSIPATION REMAINS
UNCERTAIN.
IFR CEILINGS MAY BE NEAR KGAG AND KWWR 12-17Z...BUT DID NOT
MENTION DUE TO LOW CONFIDENCE OF OCCURRENCE.
HAVE HIGH CONFIDENCE ALL SITES WILL BE VFR BY 03Z.
WINDS WILL SLOWLY DIMINISH THROUGH 23Z...THEN RAPIDLY WEAKEN
AFTER 23Z.
MBS
&&
.PREV DISCUSSION... /ISSUED 259 AM CST FRI JAN 22 2016/
DISCUSSION...
AFTER TODAY...WARMER WEATHER CAN BE EXPECTED. A DRY AND RATHER
QUIET WEATHER PATTERN IS EXPECTED FOR THE NEXT SEVEN DAYS.
TODAY WILL BE ANOTHER COLD DAY. CLOUD COVER REMAINS A BIT
TRICKY. FOLLOWED THE LATEST HRRR CEILING PRODUCT TO DEPICT CLOUD
COVER TODAY AND TONIGHT...WHICH GENERALLY DEPICTED CLOUD COVER
DECREASING ACROSS THE AREA...ESPECIALLY DURING THIS AFTERNOON AND
EVENING. APPEARS THE CLOUDS MAY HANG ON LONGEST NEAR ENID AND
MEDFORD IN PARTS OF NORTHERN OKLAHOMA. A STRAY SNOW FLURRY COULD
OCCUR NEAR PONCA CITY AND MEDFORD THIS MORNING...BUT DID NOT
MENTION DUE TO LOW CONFIDENCE OF OCCURRENCE. MODEL GUIDANCE HIGH
TEMPERATURES RANGING FROM THE MID 30S NEAR PONCA CITY TO NEAR 50
IN FAR WESTERN NORTH TEXAS NEAR KNOX CITY SEEMED REASONABLE AND
WERE FOLLOWED. WINDS WILL SLOWLY DIMINISH THIS AFTERNOON...THEN
RAPIDLY AFTER SUNSET.
TONIGHT...WENT WITH THE COLDER SIDE OF GUIDANCE LOWS TOWARDS THE
00Z METMOS NUMBERS THINKING CLEAR SKIES AND LIGHT WINDS WILL ALLOW
FOR GOOD RADIATIONAL COOLING.
SATURDAY WILL BE MOSTLY SUNNY AND WARMER WITH SURFACE WINDS SLOWLY
SHIFTING TO THE SOUTH.
SUNDAY WILL BE BREEZY TO WINDY AND WARMER YET. THINK MANY
LOCATIONS WILL GET ABOVE THE 60 DEGREE MARK. THE STRONGER WINDS
MAY ELEVATE FIRE WEATHER CONCERNS...THOUGH LOW LEVEL DEWPOINTS
WILL BE INCREASING THROUGHOUT THE DAY.
SUNDAY NIGHT INTO EARLY MONDAY...A COLD FRONT WILL MOVE THROUGH
THE AREA BRINGING A WIND SHIFT. MOISTURE APPEARS TO BE
LIMITED...SO KEPT A DRY FORECAST.
MONDAY THROUGH THURSDAY...DRY CONDITIONS WITH TEMPERATURES AT OR
ABOVE AVERAGE TEMPERATURES ARE FORECAST. A FEW WEAK COLD FRONTS
MAY MOVE THROUGH THE AREA AND BRING SURFACE WIND SHIFTS AS WELL
AS SMALL CHANGES IN TEMPERATURES EACH DAY.
MBS
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 38 21 48 32 / 0 0 0 0
HOBART OK 42 21 50 33 / 0 0 0 0
WICHITA FALLS TX 46 24 54 34 / 0 0 0 0
GAGE OK 43 16 54 30 / 0 0 0 0
PONCA CITY OK 34 13 47 30 / 0 0 0 0
DURANT OK 43 25 50 31 / 0 0 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
25/17/17
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
937 AM CST FRI JAN 22 2016
.UPDATE...
AT 9AM...
SNOW HAS TAPERED OFF QUICKLY MAINLY WEST OF THE MISSISSIPPI RIVER
AND ACROSS MUCH OF NORTH MISSISSIPPI AT THIS HOUR. THE DEFORMATION
ZONE THAT WAS DEPICTED IN THE MODELS OVER THE LAST FEW DAYS HAS
FALLEN APART EARLIER THAN ANTICIPATED AND FORECASTED.
HOWEVER...IMPACTS CONTINUE TO BE FELT ACROSS THE MAJORITY OF THE
MID-SOUTH ON THE ROADS DUE TO ICY AND SLICK CONDITIONS.
TEMPERATURES WILL CONTINUE TO FALL A BIT DURING THE AFTERNOON
HOURS...KEEPING THE MAJORITY OF THE ACCUMULATED SNOW AROUND
THROUGH AT LEAST TOMORROW AFTERNOON.
THE LATEST HRRR MODEL GUIDANCE SUGGESTS THAT WE WILL SEE PERIODIC
SNOW SHOWERS THROUGH THIS AFTERNOON...BUT THE MAJORITY OF THE SNOW
HAS ALREADY FALLEN ACROSS THE AREA. THE HARDEST HIT AREAS WERE
OVER PORTIONS OF NORTHEAST ARKANSAS AND WEST TENNESSEE WHERE MANY
REPORTS OF 4 TO 6 INCHES WERE RECEIVED. ABOUT ANOTHER 1 TO 3
INCHES WILL BE POSSIBLE WITH THE HEAVIEST SNOW BANDS OVER
NORTHWEST TENNESSEE.
WILL CONTINUE TO MONITOR CONDITIONS FOR CANCELLATION OF CURRENT
WINTER STORM WARNINGS. HAVE UPDATED THE GRIDS TO REFLECT LOWER
SNOW ACCUMULATIONS OVER THE NEXT FEW HOURS. NEW ZONES AND GRIDS
ARE NOW AVAILABLE.
AC3
&&
.PREV DISCUSSION... /ISSUED 455 AM CST FRI JAN 22 2016/
DISCUSSION...
.SIGNIFICANT WINTER STORM IMPACTING THE MID SOUTH TODAY...
SHORT TERM...TODAY THROUGH SUNDAY NIGHT...
A POWERFUL UPPER LEVEL LOW PRESSURE SYSTEM IS MOVING ACROSS THE
MID SOUTH THIS MORNING WITH SURFACE LOW PRESSURE DEEPENING AND
MOVING NORTHEAST ACROSS NORTHEAST MISSISSIPPI EARLY THIS MORNING.
THIS SURFACE LOW WILL CONTINUE TO SLOWLY LIFT NORTHEAST THROUGH
THE DAY.
HEAVY PRECIPITATION WITHIN CONVECTIVE BANDING FEATURES ASSOCIATED
WITH THE DEFORMATION ZONE IS OVER THE MID SOUTH THIS MORNING AND
WILL SLOWLY ROTATE ACROSS THE REGION FROM WEST TO EAST THROUGH THE
DAY. A WARM NOSE BASED AROUND 5 KFT THAT WAS NOTED FROM 07Z ACARS
SOUNDINGS FROM MEMPHIS INTERNATIONAL RESULTED IN FREEZING RAIN AT
THE ONSET OF PRECIPITATION ACROSS MUCH OF THE AREA WHERE SURFACE
TEMPERATURES WERE BELOW FREEZING. LATEST ACARS SOUNDING AT 10Z
INDICATES THAT THIS WARM LAYER HAS ERODED AND FREEZING RAIN HAS
CHANGED TO SNOW WEST OF THE MISSISSIPPI RIVER AND WILL CHANGEOVER
TO SNOW SHORTLY IN THE WEST TENNESSEE COUNTIES AND PORTIONS OF
NORTHWEST MISSISSIPPI. FURTHER SOUTHEAST...THE TRANSITION FROM
FREEZING RAIN TO SLEET/SNOW WILL TAKE LONGER...WITH LOCATIONS
SOUTHEAST OF TUPELO TAKING THE LONGEST WITH REDUCED ACCUMULATIONS.
HEAVY SNOWFALL WITH SOME SCATTERED THUNDERSNOW WILL BE POSSIBLE
ACROSS PORTIONS OF THE MID SOUTH BENEATH THE STRONGEST CONVECTIVE
BANDS. BENEATH THESE BANDS EARLIER ACROSS CENTRAL ARKANSAS...SNOW
RATES EXCEEDED 2 INCHES PER HOUR AND THIS WILL BE POSSIBLE ACROSS
PORTIONS OF THE WINTER STORM WARNING AREA. HEAVY SNOWFALL WILL
COMBINE WITH STRONG WINDS TO RESULT IN NEAR BLIZZARD CONDITIONS AT
TIMES WITH REDUCED VISIBILITIES AND BLOWING AND DRIFTING SNOW.
TRAVEL WILL LIKELY BECOME VERY DIFFICULT TO IMPOSSIBLE IN MANY
LOCATIONS ACROSS THE MID SOUTH LATER TODAY. TRAVEL IS NOT
RECOMMENDED.
SNOW WILL TAPER TO FLURRIES LATER THIS AFTERNOON AND EVENING FROM
WEST TO EAST WITH DIFFICULT TRAVEL CONTINUING INTO SATURDAY AS LOW
TEMPERATURES DROP INTO THE LOW TO MID 20S TONIGHT AND REMAIN BELOW
FREEZING ON SATURDAY IN MANY LOCATIONS DUE TO THE FRESH SNOWPACK.
INSOLATION FROM THE SUN WILL BEGIN THE SLOW MELTING PROCESS ON
SATURDAY WITH TRAVEL IMPROVING LATER IN THE DAY. HIGH PRESSURE
WILL KEEP DRY CONDITIONS IN PLACE INTO SUNDAY WITH SLOWLY
MODERATING TEMPERATURES AS SOUTHERLY FLOW RETURNS.
JLH
&&
$$
.LONG TERM...(MONDAY THROUGH THURSDAY)...
LONG TERM MODELS THIS MORNING INDICATE A BROAD LONGWAVE TROUGH AXIS
FROM THE GREAT LAKES REGION BACK THROUGH WEST TEXAS WILL SHIFT EAST
EARLY NEXT WEEK AS UPPER LEVEL RIDGING WEAKENS ACROSS THE LOWER
MISSISSIPPI AND TENNESSEE VALLEYS. THIS WILL ALLOW FOR ANOTHER COLD
FRONT TO MOVE THROUGH THE MID SOUTH MONDAY AND MONDAY NIGHT. RAIN
SHOWERS ARE EXPECTED WITH THIS FRONT ALONG WITH A POTENTIAL OF
PERHAPS SOME LIGHT SNOW LATE MONDAY NIGHT TOWARDS THE
MISSOURI/KENTUCKY BORDER IF MOISTURE LINGERS THROUGH THE NIGHT.
OTHERWISE...MAINLY PRECIPITATION FREE WEATHER IS EXPECTED THROUGH
THE REMAINDER OF NEXT WEEK WITH HIGH TEMPERATURES MAINLY IN THE 40S
AND LOWS IN THE UPPER 20S INTO THE 30S.
CJC
&&
.AVIATION...
12Z TAF CYCLE
PRECIPITATION ASSOCIATED WITH A STRONG UPPER LEVEL LOW HAS BEEN
GRADUALLY TRANSITIONING IN THE PAST FEW HOURS FROM FREEZING
RAIN...TO SLEET...THEN SNOW. IFR/LIFR CONDITIONS EXPECTED WITH
SNOWFALL. POTENTIAL EXISTS FOR SOME BLOWING SNOW THIS AFTERNOON AT
MEM/MKL AS NORTH WINDS EXPECTED TO AVERAGE BETWEEN 15-20 KTS WITH
GUSTS TO AVERAGING BETWEEN 22-28 KTS. CONDITIONS EXPECTED TO
IMPROVE RAPIDLY ONCE UPPER LEVEL LOW MOVES AWAY FROM THE LOWER
MISSISSIPPI VALLEY.
CJC
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...WINTER STORM WARNING UNTIL NOON CST TODAY FOR CRITTENDEN-
MISSISSIPPI.
MO...WINTER STORM WARNING UNTIL NOON CST TODAY FOR PEMISCOT.
MS...WINTER STORM WARNING UNTIL 6 PM CST THIS EVENING FOR ALCORN-
BENTON MS-CALHOUN-COAHOMA-DESOTO-LAFAYETTE-MARSHALL-PANOLA-
PONTOTOC-PRENTISS-QUITMAN-TALLAHATCHIE-TATE-TIPPAH-
TISHOMINGO-TUNICA-UNION-YALOBUSHA.
WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR
CHICKASAW-ITAWAMBA-LEE MS-MONROE.
TN...WINTER STORM WARNING UNTIL 6 PM CST THIS EVENING FOR DYER-
FAYETTE-HARDEMAN-HARDIN-HAYWOOD-LAKE-LAUDERDALE-MCNAIRY-
SHELBY-TIPTON.
WINTER STORM WARNING UNTIL 9 PM CST THIS EVENING FOR BENTON TN-
CARROLL-CHESTER-CROCKETT-DECATUR-GIBSON-HENDERSON-HENRY-
MADISON-OBION-WEAKLEY.
&&
$$
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
529 AM CST FRI JAN 22 2016
.DISCUSSION...
FROZEN PRECIPITATION BEGAN LATE YESTERDAY EVENING IN THE FAR
NORTHWEST ZONES AFTER RAINFALL EARLIER YESTERDAY. CKV REPORTED
ABOUT A TENTH OF AN INCH OF ICE FROM FZRA SO FAR THIS
EVENING...BUT SHOULD SWITCH OVER TO SNOW WITHIN THE NEXT FEW
HOURS. CURRENT LOCATION OF THE SURFACE LOW IS IN WEST CENTRAL
ALABAMA...NEAR TUSCALOOSA. ITS PATH HAS BEEN NEARLY NNE FROM THE
GULF SO FAR DURING THE OVERNIGHT HOURS. CURRENT FORECAST DEPENDS
ON THE SURFACE LOW TRACKING A BIT FURTHER EAST...ALLOWING COLD AIR
TO FILTER IN BEHIND AND MAKE SNOW THE DOMINANT PRECIP TYPE FOR THE
AREA BY THIS AFTERNOON. IF THE SURFACE LOW TRACKS FURTHER
WEST...AREAS EAST OF NASHVILLE AND ESPECIALLY SOUTHEAST MAY SEE
MORE RAIN FOR A LONGER DURATION. THIS WILL CUT INTO THE CURRENT
FORECASTED SNOW AMOUNTS FOR THAT AREA.
LOOKING AT CURRENT OBS OVERNIGHT...TEMPERATURES HAVE TRENDED A BIT
COOLER THAN PREVIOUSLY FORECASTED...SO ADJUSTED TEMPS TODAY
ACCORDINGLY. DRY SLOT HAS JUST CREPT INTO THE SOUTHWEST PART OF
THE CWA AND SHOULD IMPACT MOST OF THE AREA BEFORE THE NEXT ROUND
OF PRECIP MOVES IN. FOR THE MOST PART...DID NOT CHANGE TRANSITION
OF PRECIP TYPES FROM THE PREVIOUS FORECAST. CURRENT THINKING IS TO
HAVE THE SWITCH OVER TO ALL SNOW FOR CKV BY 12Z...NASHVILLE
SHORTLY AFTER NOON...AND CSV AFTER 21Z. STILL DIFFICULT ON TIMING
FOR THE TRANSITION TO FROZEN PRECIP AND EVENTUALLY SNOW AS MODELS
STILL DISAGREE SLIGHTLY. HRRR IS CURRENTLY CLOSEST TO OBS WITH THE
COOLER TREND...SO TRIED TO STICK CLOSE TO THE HRRR WITH TEMPS AND
THE TRANSITION. BEFORE THE TRANSITION TO ALL SNOW...WE SHOULD SEE
A MIX OF FZRA...SLEET...AS WELL AS RAIN AND SNOW ACROSS THE AREA.
AS FOR SNOW AMOUNTS...HAVE THE NORTHERN AND CENTRAL PARTS OF THE
MID STATE WITH A BIT MORE SNOW THAN THE PREVIOUS FORECAST. CURRENT
HIGH SNOW AMOUNT FOR THE AREA IS AROUND 10 INCHES IN STEWART AND
MONTGOMERY COUNTIES. WITH THE COOLER TREND TO TEMPERATURES...IT IS
POSSIBLE FOR THIS AREA TO SEE SNOW THE LONGEST AND THUS RAISED
SNOW AMOUNTS. NASHVILLE AREA LOOKS TO BE BETWEEN 4 AND 5
INCHES...WHICH IS RIGHT NEAR THE MODEL CONSENSUS FOR SNOW AMOUNTS.
AREAS IN THE FAR SOUTH NEAR THE AL BORDER DIDNT SEE MUCH OF AN
INCREASE...BUT AMOUNTS IN WAYNE AND LAWRENCE COUNTIES ARE CLOSE TO
WARNING CRITERIA. MAY NEED TO UPGRADE THOSE COUNTIES FROM AN
ADVISORY IF TEMPS DROP A BIT SOONER AND OBVIOUSLY SNOW ONSET COMES
IN SOONER AS WELL.
LATER ON THIS EVENING HEAVIER SNOW SHOULD BE EAST OF I65 AND
MAINLY ON THE PLATEAU. BY THE OVERNIGHT HOURS INTO SATURDAY
MORNING...THE UPPER LOW SHOULD BE EAST OF THE REGION AND WRAP
AROUND SNOW SHOULD BE LIGHT ON THE PLATEAU. HIGH TEMPERATURES
SATURDAY SHOULD STAY BELOW FREEZING LARGELY DUE TO THE SNOW COVER
BUT ALSO WITH CAA BEHIND THE LOW. SATURDAY NIGHT INTO SUNDAY...LOW
TEMPERATURES ARE CURRENTLY IN THE SINGLE DIGITS AND TEENS ACROSS
THE AREA...BUT MAY NEED TO DROP FURTHER IF SNOWPACK IS AS DEEP AS
THE FORECAST SUGGESTS.
NEXT CHANCE FOR PRECIP LOOKS TO BE ON MONDAY AS AN UPPER SHORTWAVE
MOVES THROUGH THE MIDWEST AND CLIPS THE REGION. KEPT WEDNESDAY AND
THURSDAY DRY BEFORE MORE PRECIP MAY CLIP THE PLATEAU THURSDAY
NIGHT INTO FRIDAY. TEMPERATURES NEXT WEEK SHOULD MAINLY BE
SLIGHTLY BELOW NORMALS WHICH ARE IN THE MID TO UPPER 40S...WITH
EXCEPTION TO NEXT FRIDAY. CURRENT FORECAST HAS HIGHS ABOVE AVERAGE
ON MONDAY...BUT SNOW COVER MAY KEEP TEMPS RIGHT AROUND AVERAGE.
&&
.AVIATION...
12Z TAF DISCUSSION.
WINTER STORM WILL TRAVERSE THE AREA DURING THE FORECAST PERIOD.
IFR OR LIFR CONDITIONS WILL PREVAIL, WITH SNOW SPREADING FROM CKV
TO BNA BY 18Z AND INTO CSV BY LATE AFTERNOON.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL NOON CST SATURDAY FOR CLAY-FENTRESS-
JACKSON-OVERTON-PICKETT.
WINTER WEATHER ADVISORY UNTIL 6 AM CST SATURDAY FOR BEDFORD-
COFFEE-GILES-LAWRENCE-MARSHALL-WAYNE.
WINTER STORM WARNING UNTIL NOON CST SATURDAY FOR CUMBERLAND-
GRUNDY-PUTNAM-VAN BUREN-WARREN-WHITE.
WINTER STORM WARNING UNTIL 6 AM CST SATURDAY FOR CANNON-CHEATHAM-
DAVIDSON-DE KALB-DICKSON-HICKMAN-HOUSTON-HUMPHREYS-LEWIS-MAURY-
PERRY-RUTHERFORD-SMITH-WILLIAMSON-WILSON.
WINTER STORM WARNING UNTIL 6 AM CST SATURDAY FOR MACON-
MONTGOMERY-ROBERTSON-STEWART-SUMNER-TROUSDALE.
&&
$$
SHORT TERM/AVIATION........55/SHAMBURGER
LONG TERM..................06/BARNWELL
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1100 AM EST FRI JAN 22 2016
.SYNOPSIS...
A DEVELOPING WINTER STORM WILL SLIDE EAST TOWARD THE SOUTHERN
APPALACHIANS TODAY BEFORE REFORMING OVER EASTERN NORTH CAROLINA BY
TONIGHT. THIS SYSTEM SHOULD PASS OFFSHORE SATURDAY FOLLOWED BY
WEAK HIGH PRESSURE SUNDAY INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1100 AM EST FRIDAY...
MAJOR WINTER STORM CONTINUES ACROSS THE AREA THIS MORNING INTO
TONIGHT. CHECK THE PNS AND LSR FOR SNOW TOTALS. SNOWFALL RATES
ON THE ORDER OF ONE TO TWO INCHES PER HOURS ARE OCCURRING
WITH THE HEAVY BANDS OF SNOW. WE ARE GETTING REPORTS OF SLEET AND
FREEZING RAIN MIXING IN. THREE MAJOR CONCERNS ARE THAT MIXED
WINTER PRECIPITATION WILL REDUCE SNOWFALL TOTALS ACROSS THE
SOUTH...THERE WILL BE A LITTLE MORE ICE ACCUMULATIONS IN THE
SOUTHEAST AND DRY AIR PUSHING IN TO THE SOUTHWEST. TREND QPF AND
SNOW TOTALS DOWN IN THE FAR WEST AND ACROSS SOUTHERN PORTIONS OF
FORECAST AREA. ADDED SOME ICE TO THE SOUTH. NEW SNOW AND ICE
TOTALS POSTED TO WEB. USED BLEND OF NAM AND CONTINUITY TO SHAPE
TEMPERATURE PROFILES...THEN CALCULATED WEATHER TYPES USING TOPDOWN
METHOD. ADJUSTED TEMPERATURES WITH LATEST TRENDS FOR THIS MORNING
INTO THIS AFTERNOON. MORE CHANGES LATER TODAY...
AS OF 245 AM EST FRIDAY...
NOT A LOT OF CHANGE TO THE GOING FORECAST WITH LOW PRESSURE NOW OVER
THE LOWER MISSISSIPPI VALLEY PROGGED TO RIDE UP INTO THE SOUTHERN
APPALACHIANS TODAY BEFORE GIVING WAY TO A DEEPENING COASTAL LOW OVER
EASTERN NC BY TONIGHT. PRECIP ALREADY CROSSING INTO SW VA WILL
QUICKLY SPREAD NORTH/EAST THROUGH THE MORNING AND BECOME HEAVIER
AS RESULTANT DEEP SE FLOW KICKS IN ALOFT AHEAD OF THE INITIAL
WAVE. MODELS REMAIN VERY IMPRESSIVE WITH SNOWFALL DURING THE DAY
WITH JUST ABOUT A PERFECT SETUP WITH STRONG UVV WITHIN THE
DENDRITIC ZONE AND CSI BANDING IF THEY ARE CORRECT. SOME GUIDANCE
ESPCLY THE GFS SHOWING SNOWFALL OF BETTER THAN 4-6 INCHES IN 6
HOURS THROUGH 00Z THIS EVENING SO APPEARS A LOT OF THE HEAVIER
SNOWFALL WILL OCCUR DURING THE DAY. THUS BOOSTED SNOWFALL AMOUNTS
ON THE FRONT END TODAY WITH A GOOD 10 INCHES TO A FOOT OR MORE
POSSIBLE JUST THROUGH SUNSET. HOWEVER THE LATEST CMC AND SOME
LOCAL SOLUTIONS A BIT FASTER WITH THE DRY SLOT THIS
AFTERNOON...ESPCLY THE LATEST HRRR WHICH REALLY CUTS BACK ON
AMOUNTS AFTER MIDDAY. THEREFORE SOMETHING TO WATCH ESPCLY GIVEN
SUCH STRONG LIFT THIS MORNING...AND POTENTIAL FOR THE UPPER JET
NOW BACK TO THE SW TO CORE OUT THE DEEPER MOISTURE RESULTING IN
LESS HEAVY SNOW LATER ON AS A PERIOD OF WEAK SUBSIDENCE ALOFT
SHIFTS NE. SLIGHTLY BETTER WARM NOSE ALSO SHOWING UP OVER THE FAR
SOUTH ESPCLY OFF THE NAM...MAINLY LATE IN THE WAKE OF THE BETTER
DYNAMIC COOLING SO INCLUDED A LITTLE MORE SLEET NW NC INTO
SOUTHSIDE VA. EVEN SOME FZRA POSSIBLE MAINLY FAR SE WHEN THE
TRANSITION FROM THE INLAND WAVE TO THE COASTAL TAKES SHAPE AS SEEN
WITH A SIMILAR SETUP IN THE PAST. EXPECT TEMPS TO FALL ONCE THE
PRECIP STARTS GIVEN DRY AIR WHICH MAY DELAY THE ONSET A BIT
FARTHER NORTH. OTRW LOOKING AT MAINLY 20S FOR HIGHS WITH SOME
READINGS SPILLING BACK INTO THE TEENS THIS MORNING.
AXIS OF DEEPER MOISTURE PROGGED TO LIFT OUT TO THE NORTH AND EAST
OVERNIGHT WITH MOST SOLUTIONS SHOWING A PRONOUNCED DRY SLOT OVER THE
SOUTH/WEST UNDER THE PASSAGE OF THE UPPER LOW. THIS SUPPORTS SOME
DOWNTURN IN SNOWFALL OUTSIDE OF THE FAR EASTERN/NORTHERN ZONES THIS
EVENING WITH MOSTLY BANDS OF LIGHT/MODERATE SNOW LIKELY PERSISTING
ELSEWHERE. HOWEVER QUITE A BIT LESS SOUTHERN HALF WHERE STILL MAY SEE A
MIX EARLY ON. THUS TRIMMED BACK POPS A LITTLE LATE TONIGHT BUT OVERALL
STILL A FEW ADDED INCHES WEST TO SEVERAL OUT EAST. WITH THE COASTAL LOW
DEEPENING AND PASSING JUST OFFSHORE LATE...EXPECT WINDS TO PICK UP
ESPCLY EAST OF THE BLUE RIDGE WHERE LOTS OF BLOWING/DRIFTING SNOW
LIKELY. APPEARS WINDS WILL STAY BELOW BLIZZARD CRITERIA BUT MAY NEED TO
CONSIDER FOR LATER TONIGHT OVER THE FAR NORTH/NE. AS THE FLOW TURNS
MORE NE WILL SEE TEMPS SLOWLY RISE IN THE 20S LATER TONIGHT AS SNOW
TURNS A BIT WETTER WITH THE INFLUX OF ATLANTIC MOISTURE.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 350 AM EST FRIDAY...
LOOKING TO SATURDAY MORNING...THE CENTER OF THE UPPER LEVEL LOW WILL
BE OVER CENTRAL NORTH CAROLINA...WHILE THE SURFACE REFLECTION OF THE
SYSTEM WILL BE LOCATED JUST EAST OF THE MOUTH OF CHESAPEAKE BAY...
RESULTING IN NORTHERLY WINDS ACROSS OUR AREA. WEATHER FORECAST
MODELS ARE HINTING THAT THE HEAVIEST PRECIPITATION BANDS WILL HAVE
EXITED OUR AREA BEFORE DAWN AS DRIER AIR WORKS INTO THE CENTRAL
APPALACHIANS...AND THAT SNOWFALL WILL TRANSITION FROM WIDESPREAD
LIGHT TO OCCASIONALLY MODERATE ACTIVITY AROUND DAWN...TO MORE OF A
SCATTERED UPSLOPE SNOW SHOWER VARIETY HEADING INTO THE EVENING.
BELIEVE THE HIGHEST SNOWFALL TOTALS FOR OUR AREA ON SATURDAY WILL
OCCUR ALONG THE INTERSTATE 64 CORRIDOR... WHERE AN ADDITIONAL 3 TO 5
INCHES ARE POSSIBLE...MAINLY THROUGH EARLY AFTERNOON. SNOWFALL
AMOUNTS WILL TAPER DOWN TO LESS THAN AN ADDITIONAL INCH OF NEW SNOW
ACROSS PORTIONS OF THE PIEDMONT IN NORTH CAROLINA. BY SATURDAY
EVENING...THE LOW PRESSURE SYSTEM WILL HAVE MOVED FAR ENOUGH AWAY
THAT THE ONLY REMAINING SNOWFALL WILL BE RAPIDLY DIMINISHING UPSLOPE
SNOW SHOWERS ALONG THE WESTERN RIDGES...WITH MINIMAL NEW
ACCUMULATION.
IN ADDITION TO NEW SNOWFALL ACCUMULATIONS...WILL ALSO BE CONCERNED
WITH GUSTY WINDS AS THE LOW PRESSURE SYSTEM DEEPENS THROUGH THE
DAY...CAUSING THE PRESSURE GRADIENT ACROSS OUR AREA TO TIGHTEN.
BELIEVE 20 TO 30 MPH GUSTS WILL BE COMMON THROUGH THE DAY...WITH 40+
MPH GUSTS POSSIBLE ACROSS THE HIGHER RIDGES. THESE GUSTY WINDS WILL
LIKELY RESULT IN WIDESPREAD BLOWING SNOW...WHICH MAY LEAD TO
LOCALIZED WHITEOUT CONDITIONS REGARDLESS OF WHAT IS FALLING FROM THE
SKY. WINDS WILL REMAIN GUSTY THROUGH SATURDAY NIGHT...BEFORE
DIMINISHING ON SUNDAY AS HIGH PRESSURE SETTLES ACROSS THE AREA FROM
THE WEST.
WITH THE DEPARTURE OF THE UPPER LEVEL LOW SATURDAY NIGHT...RIDGING
ALOFT WILL PUSH IN FROM THE WEST ON SUNDAY. DOWNSLOPE NORTHWESTERLY
WINDS...COMBINED WITH ABUNDANT SUNSHINE...WILL MAKE FOR WARMER
AFTERNOON TEMPERATURES AS HIGHS RANGE FROM THE UPPER 20S/LOW 30S
ACROSS SOUTHEAST WEST VIRGINIA...TO THE MID/UPPER 30S OVER THE
SOUTHSIDE. CLEAR SKIES WILL PERSIST INTO SUNDAY NIGHT...WHERE STRONG
RADIATIONAL COOLING DUE TO LIGHT WINDS AND ABUNDANT SNOW COVER WILL
CAUSE THE LOWER ELEVATIONS TO FALL INTO THE TEENS AND THE POSITIVE
SINGLE DIGITS...WHILE WINDS SHIFT SOUTHWESTERLY ALOFT...ALLOWING
WARMER AIR TO FILTER IN TO KEEP THE RIDGETOPS IN THE 20S.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 400 AM EST FRIDAY...
HIGH PRESSURE WILL PASS EAST OF THE REGION ON MONDAY WITH GENERALLY
FAIR WEATHER AND WARMER TEMPERATURES EXPECTED. OUR NEXT CHANCE OF
PRECIPITATION ARRIVES ON TUESDAY AS A LOW PRESSURE SYSTEM MOVES
THROUGH THE GREAT LAKES REGION AND PUSHES A FRONT INTO THE REGION
FROM THE WEST. UPSLOPE SNOW SHOWERS WILL THEN LINGER WEST OF THE
BLUE RIDGE AS SOMEWHAT COLDER AIR ARRIVES FOR THE MIDDLE OF NEXT
WEEK.
&&
.AVIATION /16Z FRIDAY THROUGH TUESDAY/...
AS OF 600 AM EST FRIDAY...
VERY POOR AVIATION CONDITIONS EXPECTED THROUGH THE END OF VALID
TAF PERIOD...
SNOW WILL CONTINUE TO OVERSPREAD THE REGION FROM SOUTHWEST TO
NORTHEAST EARLY THIS MORNING. CEILINGS AND VISIBILITIES WILL
DECREASE INTO IFR RANGE FOR MOST OF THE AREA WITHIN A COUPLE HOURS
OF THE ONSET OF THE PRECIPITATION...WITH IFR TO LIFR CIGS/VSBYS
EXPECTED BY MID/LATE MORNING IN MODERATE TO HEAVY SNOW AND FOG.
SOME DECREASE IN PRECIPITATION MAY OCCUR LATE IN THE DAY AS THE
FIRST WAVE MOVES OFF TO THE NORTHEAST OF THE REGION. LIFR CEILINGS
WILL BE POSSIBLE LATE IN THE DAY THROUGH THE EVENING IN SNOW AND
FOG. WINDS WILL TREND NORTHEAST TO EAST DURING THE 24 HOUR TIME
FRAME...WITH SPEEDS INCREASING INTO THE 10 TO 20 KT RANGE AFTER
18Z/2PM FRIDAY. WINDS WILL ALSO BECOME GUSTY ESPCLY FROM THE BLUE
RIDGE EAST BY TONIGHT WITH GUSTS TO 25-30 KTS POSSIBLE AROUND
KLYH.
WINTER STORM CONTINUES TONIGHT INTO SATURDAY WITH WIDESPREAD SUB
VFR CONDITIONS ALTHOUGH EXPECTING WIDESPREAD SNOWFALL TO TAPER OFF
LATER TONIGHT ACROSS SOUTHERN AND WESTERN SECTIONS.
MEDIUM TO HIGH CONFIDENCE IN CIGS AND VSBYS THROUGH THE TAF VALID
PERIOD. MEDIUM TO HIGH CONFIDENCE IN WIND DIR/SPEED THROUGH THE
TAF VALID PERIOD.
EXTENDED DISCUSSION...
THIS SYSTEM IS LIKELY TO RESULT IN LITTLE TO NO AIR TRAVEL IN OUR
REGION TODAY- SATURDAY WITH AIRPORTS CLOSED. BY SUNDAY WE ARE
GOING TO BE UNDER INCREASING HIGH PRESSURE WITH VFR LIKELY INTO
MONDAY. ANOTHER COLD FRONT MAY BRING THE NEXT CHANCE FOR
PRECIPITATION INCLUDING SUB-VFR CONDITIONS ON TUESDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WINTER STORM WARNING UNTIL 6 AM EST SUNDAY FOR VAZ007-009>020-
022>024-032>035-043>047-058-059.
NC...WINTER STORM WARNING UNTIL 6 AM EST SUNDAY FOR NCZ001>006-
018>020.
WV...WINTER STORM WARNING UNTIL 6 AM EST SUNDAY FOR WVZ042>044-507-
508.
&&
$$
SYNOPSIS...JH/KK
NEAR TERM...JH/KK
SHORT TERM...NF
LONG TERM...NF
AVIATION...DS/JH/KK
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
608 AM EST FRI JAN 22 2016
.SYNOPSIS...
A DEVELOPING WINTER STORM WILL SLIDE EAST TOWARD THE SOUTHERN
APPALACHIANS TODAY BEFORE REFORMING OVER EASTERN NORTH CAROLINA BY
TONIGHT. THIS SYSTEM SHOULD PASS OFFSHORE SATURDAY FOLLOWED BY
WEAK HIGH PRESSURE SUNDAY INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 245 AM EST FRIDAY...
NOT A LOT OF CHANGE TO THE GOING FORECAST WITH LOW PRESSURE NOW OVER
THE LOWER MISSISSIPPI VALLEY PROGGED TO RIDE UP INTO THE SOUTHERN
APPALACHIANS TODAY BEFORE GIVING WAY TO A DEEPENING COASTAL LOW OVER
EASTERN NC BY TONIGHT. PRECIP ALREADY CROSSING INTO SW VA WILL
QUICKLY SPREAD NORTH/EAST THROUGH THE MORNING AND BECOME HEAVIER
AS RESULTANT DEEP SE FLOW KICKS IN ALOFT AHEAD OF THE INITIAL
WAVE. MODELS REMAIN VERY IMPRESSIVE WITH SNOWFALL DURING THE DAY
WITH JUST ABOUT A PERFECT SETUP WITH STRONG UVV WITHIN THE
DENDRITIC ZONE AND CSI BANDING IF THEY ARE CORRECT. SOME GUIDANCE
ESPCLY THE GFS SHOWING SNOWFALL OF BETTER THAN 4-6 INCHES IN 6
HOURS THROUGH 00Z THIS EVENING SO APPEARS A LOT OF THE HEAVIER
SNOWFALL WILL OCCUR DURING THE DAY. THUS BOOSTED SNOWFALL AMOUNTS
ON THE FRONT END TODAY WITH A GOOD 10 INCHES TO A FOOT OR MORE
POSSIBLE JUST THROUGH SUNSET. HOWEVER THE LATEST CMC AND SOME
LOCAL SOLUTIONS A BIT FASTER WITH THE DRY SLOT THIS
AFTERNOON...ESPCLY THE LATEST HRRR WHICH REALLY CUTS BACK ON
AMOUNTS AFTER MIDDAY. THEREFORE SOMETHING TO WATCH ESPCLY GIVEN
SUCH STRONG LIFT THIS MORNING...AND POTENTIAL FOR THE UPPER JET
NOW BACK TO THE SW TO CORE OUT THE DEEPER MOISTURE RESULTING IN
LESS HEAVY SNOW LATER ON AS A PERIOD OF WEAK SUBSIDENCE ALOFT
SHIFTS NE. SLIGHTLY BETTER WARM NOSE ALSO SHOWING UP OVER THE FAR
SOUTH ESPCLY OFF THE NAM...MAINLY LATE IN THE WAKE OF THE BETTER
DYNAMIC COOLING SO INCLUDED A LITTLE MORE SLEET NW NC INTO
SOUTHSIDE VA. EVEN SOME FZRA POSSIBLE MAINLY FAR SE WHEN THE
TRANSITION FROM THE INLAND WAVE TO THE COASTAL TAKES SHAPE AS SEEN
WITH A SIMILAR SETUP IN THE PAST. EXPECT TEMPS TO FALL ONCE THE
PRECIP STARTS GIVEN DRY AIR WHICH MAY DELAY THE ONSET A BIT
FARTHER NORTH. OTRW LOOKING AT MAINLY 20S FOR HIGHS WITH SOME
READINGS SPILLING BACK INTO THE TEENS THIS MORNING.
AXIS OF DEEPER MOISTURE PROGGED TO LIFT OUT TO THE NORTH AND EAST
OVERNIGHT WITH MOST SOLUTIONS SHOWING A PRONOUNCED DRY SLOT OVER THE
SOUTH/WEST UNDER THE PASSAGE OF THE UPPER LOW. THIS SUPPORTS SOME
DOWNTURN IN SNOWFALL OUTSIDE OF THE FAR EASTERN/NORTHERN ZONES THIS
EVENING WITH MOSTLY BANDS OF LIGHT/MODERATE SNOW LIKELY PERSISTING
ELSEWHERE. HOWEVER QUITE A BIT LESS SOUTHERN HALF WHERE STILL MAY SEE A
MIX EARLY ON. THUS TRIMMED BACK POPS A LITTLE LATE TONIGHT BUT OVERALL
STILL A FEW ADDED INCHES WEST TO SEVERAL OUT EAST. WITH THE COASTAL LOW
DEEPENING AND PASSING JUST OFFSHORE LATE...EXPECT WINDS TO PICK UP
ESPCLY EAST OF THE BLUE RIDGE WHERE LOTS OF BLOWING/DRIFTING SNOW
LIKELY. APPEARS WINDS WILL STAY BELOW BLIZZARD CRITERIA BUT MAY NEED TO
CONSIDER FOR LATER TONIGHT OVER THE FAR NORTH/NE. AS THE FLOW TURNS
MORE NE WILL SEE TEMPS SLOWLY RISE IN THE 20S LATER TONIGHT AS SNOW
TURNS A BIT WETTER WITH THE INFLUX OF ATLANTIC MOISTURE.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 350 AM EST FRIDAY...
LOOKING TO SATURDAY MORNING...THE CENTER OF THE UPPER LEVEL LOW WILL
BE OVER CENTRAL NORTH CAROLINA...WHILE THE SURFACE REFLECTION OF THE
SYSTEM WILL BE LOCATED JUST EAST OF THE MOUTH OF CHESAPEAKE BAY...
RESULTING IN NORTHERLY WINDS ACROSS OUR AREA. WEATHER FORECAST
MODELS ARE HINTING THAT THE HEAVIEST PRECIPITATION BANDS WILL HAVE
EXITED OUR AREA BEFORE DAWN AS DRIER AIR WORKS INTO THE CENTRAL
APPALACHIANS...AND THAT SNOWFALL WILL TRANSITION FROM WIDESPREAD
LIGHT TO OCCASIONALLY MODERATE ACTIVITY AROUND DAWN...TO MORE OF A
SCATTERED UPSLOPE SNOW SHOWER VARIETY HEADING INTO THE EVENING.
BELIEVE THE HIGHEST SNOWFALL TOTALS FOR OUR AREA ON SATURDAY WILL
OCCUR ALONG THE INTERSTATE 64 CORRIDOR... WHERE AN ADDITIONAL 3 TO 5
INCHES ARE POSSIBLE...MAINLY THROUGH EARLY AFTERNOON. SNOWFALL
AMOUNTS WILL TAPER DOWN TO LESS THAN AN ADDITIONAL INCH OF NEW SNOW
ACROSS PORTIONS OF THE PIEDMONT IN NORTH CAROLINA. BY SATURDAY
EVENING...THE LOW PRESSURE SYSTEM WILL HAVE MOVED FAR ENOUGH AWAY
THAT THE ONLY REMAINING SNOWFALL WILL BE RAPIDLY DIMINISHING UPSLOPE
SNOW SHOWERS ALONG THE WESTERN RIDGES...WITH MINIMAL NEW
ACCUMULATION.
IN ADDITION TO NEW SNOWFALL ACCUMULATIONS...WILL ALSO BE CONCERNED
WITH GUSTY WINDS AS THE LOW PRESSURE SYSTEM DEEPENS THROUGH THE
DAY...CAUSING THE PRESSURE GRADIENT ACROSS OUR AREA TO TIGHTEN.
BELIEVE 20 TO 30 MPH GUSTS WILL BE COMMON THROUGH THE DAY...WITH 40+
MPH GUSTS POSSIBLE ACROSS THE HIGHER RIDGES. THESE GUSTY WINDS WILL
LIKELY RESULT IN WIDESPREAD BLOWING SNOW...WHICH MAY LEAD TO
LOCALIZED WHITEOUT CONDITIONS REGARDLESS OF WHAT IS FALLING FROM THE
SKY. WINDS WILL REMAIN GUSTY THROUGH SATURDAY NIGHT...BEFORE
DIMINISHING ON SUNDAY AS HIGH PRESSURE SETTLES ACROSS THE AREA FROM
THE WEST.
WITH THE DEPARTURE OF THE UPPER LEVEL LOW SATURDAY NIGHT...RIDGING
ALOFT WILL PUSH IN FROM THE WEST ON SUNDAY. DOWNSLOPE NORTHWESTERLY
WINDS...COMBINED WITH ABUNDANT SUNSHINE...WILL MAKE FOR WARMER
AFTERNOON TEMPERATURES AS HIGHS RANGE FROM THE UPPER 20S/LOW 30S
ACROSS SOUTHEAST WEST VIRGINIA...TO THE MID/UPPER 30S OVER THE
SOUTHSIDE. CLEAR SKIES WILL PERSIST INTO SUNDAY NIGHT...WHERE STRONG
RADIATIONAL COOLING DUE TO LIGHT WINDS AND ABUNDANT SNOW COVER WILL
CAUSE THE LOWER ELEVATIONS TO FALL INTO THE TEENS AND THE POSITIVE
SINGLE DIGITS...WHILE WINDS SHIFT SOUTHWESTERLY ALOFT...ALLOWING
WARMER AIR TO FILTER IN TO KEEP THE RIDGETOPS IN THE 20S.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 400 AM EST FRIDAY...
HIGH PRESSURE WILL PASS EAST OF THE REGION ON MONDAY WITH GENERALLY
FAIR WEATHER AND WARMER TEMPERATURES EXPECTED. OUR NEXT CHANCE OF
PRECIPITATION ARRIVES ON TUESDAY AS A LOW PRESSURE SYSTEM MOVES
THROUGH THE GREAT LAKES REGION AND PUSHES A FRONT INTO THE REGION
FROM THE WEST. UPSLOPE SNOW SHOWERS WILL THEN LINGER WEST OF THE
BLUE RIDGE AS SOMEWHAT COLDER AIR ARRIVES FOR THE MIDDLE OF NEXT
WEEK.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AS OF 600 AM EST FRIDAY...
...VERY POOR AVIATION CONDITIONS EXPECTED THROUGH THE END OF VALID
TAF PERIOD...
SNOW WILL CONTINUE TO OVERSPREAD THE REGION FROM SOUTHWEST TO
NORTHEAST EARLY THIS MORNING. CEILINGS AND VISIBILITIES WILL
DECREASE INTO IFR RANGE FOR MOST OF THE AREA WITHIN A COUPLE HOURS
OF THE ONSET OF THE PRECIPITATION...WITH IFR TO LIFR CIGS/VSBYS
EXPECTED BY MID/LATE MORNING IN MODERATE TO HEAVY SNOW AND FOG.
SOME DECREASE IN PRECIPITATION MAY OCCUR LATE IN THE DAY AS THE
FIRST WAVE MOVES OFF TO THE NORTHEAST OF THE REGION. LIFR CEILINGS
WILL BE POSSIBLE LATE IN THE DAY THROUGH THE EVENING IN SNOW AND
FOG. WINDS WILL TREND NORTHEAST TO EAST DURING THE 24 HOUR TIME
FRAME...WITH SPEEDS INCREASING INTO THE 10 TO 20 KT RANGE AFTER
18Z/2PM FRIDAY. WINDS WILL ALSO BECOME GUSTY ESPCLY FROM THE BLUE
RIDGE EAST BY TONIGHT WITH GUSTS TO 25-30 KTS POSSIBLE AROUND
KLYH.
WINTER STORM CONTINUES TONIGHT INTO SATURDAY WITH WIDESPREAD SUB
VFR CONDITIONS ALTHOUGH EXPECTING WIDESPREAD SNOWFALL TO TAPER OFF
LATER TONIGHT ACROSS SOUTHERN AND WESTERN SECTIONS.
MEDIUM TO HIGH CONFIDENCE IN CIGS AND VSBYS THROUGH THE TAF VALID
PERIOD. MEDIUM TO HIGH CONFIDENCE IN WIND DIR/SPEED THROUGH THE
TAF VALID PERIOD.
EXTENDED DISCUSSION...
THIS SYSTEM IS LIKELY TO RESULT IN LITTLE TO NO AIR TRAVEL IN OUR
REGION TODAY- SATURDAY WITH AIRPORTS CLOSED. BY SUNDAY WE ARE
GOING TO BE UNDER INCREASING HIGH PRESSURE WITH VFR LIKELY INTO
MONDAY. ANOTHER COLD FRONT MAY BRING THE NEXT CHANCE FOR
PRECIPITATION INCLUDING SUB-VFR CONDITIONS ON TUESDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WINTER STORM WARNING UNTIL 6 AM EST SUNDAY FOR VAZ007-009>020-
022>024-032>035-043>047-058-059.
NC...WINTER STORM WARNING UNTIL 6 AM EST SUNDAY FOR NCZ001>006-
018>020.
WV...WINTER STORM WARNING UNTIL 6 AM EST SUNDAY FOR WVZ042>044-507-
508.
&&
$$
SYNOPSIS...JH/KK
NEAR TERM...JH
SHORT TERM...NF
LONG TERM...NF
AVIATION...DS/JH/KK
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
414 AM MST FRI JAN 22 2016
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 414 AM MST FRI JAN 22 2016
A LOCALIZED AREA OF DENSE FOG DEVELOPED AROUND KAIA LAST EVENING AND
HAS PERSISTED THROUGH THE NIGHT. RAP BUFKIT SOUNDINGS SHOW EXCELLENT
LLVL SATURATION AND VERY LIGHT NEAR-SFC FLOW THROUGH 16Z...SO DO NOT
BELIEVE FOG WILL DISSIPATE ANYTIME SOON. ISSUED A DENSE FOG ADVISORY
FOR BOX BUTTE COUNTY UNTIL 9 AM MST. PATCHY FOG IS ALSO OCCURRING IN
OTHER PORTIONS OF THE PANHANDLE...BUT NOT AS DENSE. NO MAJOR WEATHER
CONCERNS THROUGH SATURDAY WITH UPPER-LEVEL RIDGING IN PLACE. IT WILL
BE QUITE MILD ALONG/EAST OF THE LARAMIE RANGE ON FRIDAY AND SATURDAY
AFTERNOONS WITH FAVORABLE DOWNSLOPING AND H7 TEMPS OF +1C TO +3C. WE
SHOULD SEE CONSISTENT BREEZY CONDITIONS IN THE ARLINGTON AREA AS 700
MB FLOW REMAINS BETWEEN 30 AND 40 KTS AND THE CAG-CPR GRADIENT STAYS
AROUND 40 METERS. BEST CHANCE FOR HIGH WINDS IN THE WIND PRONE AREAS
WOULD BE BETWEEN 09Z AND 15Z SAT AS THE NAM 850 HPA CAG-CPR GRADIENT
CLIMBS ABOVE 50 METERS...BUT DO NOT THINK WINDS ALOFT UNDER 45 KNOTS
WILL SUPPORT WARNING-CRITERIA GUSTS. SOUTHWEST FLOW ALOFT IS PROGGED
TO INCREASE ON SATURDAY IN ADVANCE OF A PROGRESSIVE SHORTWAVE TROUGH
EXPECTED TO TRACK ACROSS THE CWA FROM SAT NIGHT THROUGH MON...WITH A
SURFACE COLD FROPA ON SUN AM. BEST PRECIP CHANCES WILL BE POST-FROPA
AFTER 12Z SUN...BUT WILL LIKELY BEGIN SLIGHTLY EARLIER ALONG/WEST OF
THE LARAMIE RANGE. WINTER WEATHER ADVISORIES COULD BE NEEDED FOR THE
MOUNTAINS AT SOME POINT WITH GFS/NAM BOTH SHOWING QPF AMOUNTS AROUND
0.5 INCH OWING TO FAVORABLE OROGRAPHICS. AMOUNTS SHOULD GENERALLY BE
LESS THAN 3 INCHES FOR MOST LOWER-ELEVATION AREAS.
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 414 AM MST FRI JAN 22 2016
UPPER RIDGE AXIS ALONG THE WEST COAST WILL YIELD PERSISTENT NW
FLOW OVR THE NRN ROCKIES/PLAINS NEXT WEEK. ASIDE FROM SOME LIGHT
SNOWS OVER THE SNOWY AND SIERRA MADRE RANGES ON MONDAY...EXPECT
GENERALLY DRY CONDITIONS TO PREVAIL FOR THE REMAINDER NEXT WEEK.
BREEZY TO LOCALLY WINDY CONDITIONS WILL BE THE MAIN STORY. ON
MONDAY/TUESDAY...MODELS PROG 20-30 KNOTS AT THE TOP OF THE ML...
YIELDING WIND GUSTS THAT WILL REACH 30-40 MPH DURING THE AFTERNOON
HOURS. THESE WINDS WILL COMBINE WITH HIGH TEMPERATURES THAT WILL
ONLY REACH THE 30S TO MAKE IT FEEL 10-20 DEGREES COLDER. MODELS
PROG KCAG-KCPR GRADIENTS TO PEAK WEDNESDAY MORNING AT 50-55 METERS
WHICH MAY YIELD A MARGINAL HIGH WIND EVENT FOR THE USUALLY WINDY
AREAS OF SOUTHEAST WYOMING. WARMER TEMPERATURES RETURN WED-FRI
WITH HIGHS REACHING INTO THE 30S WEST OF THE LARAMIE RANGE WITH
40S/LOW 50S ACROSS THE ERN PLAINS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 414 AM MST FRI JAN 22 2016
THE MAIN AVIATION CONCERN FOR THIS TAF CYCLE WILL BE INITIALLY AT
KCDR AND KAIA WHERE ONGOING LIFR VSBYS/CIGS IN FG CONTINUE FOR THE
NEXT SEVERAL HOURS. EXPECT THIS FOG TO DISSIPATE BY 15-17Z...WITH
VFR CONDITIONS RETURNING THEREAFTER. VFR CONDITIONS WILL PREVAIL
THROUGH THE PERIOD ELSEWHERE.
&&
.FIRE WEATHER...
ISSUED AT 414 AM MST FRI JAN 22 2016
WARM AND DRY CONDITIONS ARE LIKELY FOR FRI/SAT WITH DAYTIME HIGHS IN
THE 40S AND 50S OVER THE HIGH PLAINS. AFTERNOON HUMIDITY VALUES WILL
LIKELY REMAIN OUTSIDE OF CRITICAL THRESHOLDS...BUT COULD DROP AS LOW
AS 25 PERCENT. BREEZY TO LOCALLY WINDY CONDITIONS CAN BE EXPECTED IN
AREAS ALONG/WEST OF THE LARAMIE RANGE THROUGH THE WEEKEND. A WEATHER
DISTURBANCE AND ASSOCIATED COLD FRONT WILL MOVE ACROSS THE REGION ON
SATURDAY NIGHT AND SUNDAY...BRINGING COOLER AIR AND WIDESPREAD LIGHT
SNOW.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...DENSE FOG ADVISORY UNTIL 9 AM MST THIS MORNING FOR NEZ003.
&&
$$
SHORT TERM...CLH
LONG TERM...CAH
AVIATION...CAH
FIRE WEATHER...CLH
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1215 PM CST FRI JAN 22 2016
.UPDATE...
ISSUED AT 1054 AM CST FRI JAN 22 2016
Storm system passing across the southern portions of the United
States and lifting through the Appalachians this morning keeping
the flow north northeasterly over Central Illinois with plenty of
mid level clouds. Some light snow showers cannot be ruled out in
the extreme SE/Southern portions of Illinois today, well south of
I-70. Another area of echos on radar up in the Chicago area
starting to show some lake effect snow with the NNE winds. Always
something to watch how far south it will get down the I-55
corridor, but for now will leave the forecast dry in the north.
May have to add some flurries later, but so far, the echos are
disintegrating further south. No major updates to the forecast
expected at this time.
&&
.SHORT TERM...(Today)
ISSUED AT 329 AM CST FRI JAN 22 2016
The storm system that will affect the East Coast over the next
several days was gathering strength over western Alabama as of 2am.
The precipitation shield associated with the storm was pushing into
extreme southern Illinois with models continuing to suggest the bulk
of the snow will stay just south of Lawrenceville today. Will
continue to hang on to at least slight chance wording in our far
southeast counties to account for any northward shift in the precip
today, however, forecast soundings and time-height cross sections
showing quite a bit of dry air from 925-800 my layer so if the snow
is able to make it to the surface, it will be on the light side with
the more significant accumulating snowfall remaining south.
Further north, a weak shortwave seen on the water vapor loop over
the Great Lakes will shift southeast today with the main forecast
concern with that feature being a large deck of stratus along and
to the north of the trof axis in addition to some scattered flurries.
May see the lower deck gradually work its way south into the
forecast area during the day today but most of the short term models
indicate any light snow or flurries with the upper wave will remain
to our west and north today. Something to keep an eye on in the
short term with both the HRRR and RAP models indicating the north to
northeasterly flow off of Lake Michigan may push some flurries
southwest to parts of north-central Illinois this afternoon. Not
much of a big diurnal shift in temperatures today due to the cloud
cover with most areas in the upper 20s to lower 30s this afternoon.
.LONG TERM...(Tonight through Thursday)
ISSUED AT 329 AM CST FRI JAN 22 2016
Strong low pressure to deepen and move off the NC coast overnight
with its snow mainly along and se of the Ohio river pulling further
away from southeast IL, while clouds begin to decrease from the nw
during overnight. Breezy north winds to continue tonight especially
in eastern IL closer to strong low pressure near the NC coast. Lows
tonight in the upper teens central IL and lower 20s se of I-70.
With Nor`easter off the mid Atlantic and New England coast Saturday
and Saturday night bringing a major winter storm to mid Atlantic
states and southern New England, quiet weather expected for IL this
weekend. Mostly sunny skies Saturday over central and southeast IL
with surface ridge over the MS river valley by sunset Saturday and
as upper level ridge shifts east into IL by Sunday. Highs mostly in
the lower 30s Saturday with NNW winds keeping it cool. Temps modify
Sunday into the mid 30s to around 40F with increasing south winds
on Sunday along with some increase clouds over central IL.
A storm system off the West Coast to bring an upper level trof east
into IL by Monday evening while weak surface low pressure tracks
from the OK panhandle at sunset Sunday into ne IL by sunday Monday.
Still dry Sunday night with light precipitation spreading east over
IL during the day Monday. 00Z models have trended slower with
arrival of this weather system, so think surface temps will be above
freezing by time precipitation starts. Monday looks warm enough to
support mainly light rain with chance of light snow over northern
CWA Monday morning and far NW CWA by Knox and Stark counties Monday
afternoon with little or no accumulations. Above normal highs Monday
in the upper 30s/lower 40s.
A bit cooler air moves in behind a cold front during Monday night as
light rain changes to light snow before diminishing to flurries and
linger into Tue with upper level trof over the Great lakes and into
IL. Any snowfall amounts appear quite light if they occur Monday
night generally less than a half inch. Highs Tue around 30F northern
CWA to near 35F far se IL along and south of highway 50. Weak high
pressure near IL Wed with dry conditions and partly sunny skies with
highs mostly in the lower 30s. 00Z models have trended further nne
with northern stream short wave/clipper system on Thu where brunt of
light snow chances pass ne of central IL with just slight chances
for central and ne CWA. Temps to modify back into mid to upper 30s
Thu and a few degrees milder next Friday in upper 30s/lower 40s.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
ISSUED AT 1209 PM CST FRI JAN 22 2016
Northerly winds today staying under 15kts so far, but with some
higher winds off the surface, keeping the gusts in the TAFs. Low
clouds mainly MVFR across the region, but coming in low for PIA
and BMI on the last obs. Along with reduced visibilities with the
warmer air over the snowpack. Low level moisture not scouring out
of the models until after 12z. Keeping MVFR through the overnight
with northerly winds. Clearing in the morning may be optimistic,
but splitting difference between model RH fields and guidance.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...HJS
SHORT TERM...Smith
LONG TERM...07
AVIATION...HJS
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1058 AM CST FRI JAN 22 2016
.UPDATE...
ISSUED AT 1054 AM CST FRI JAN 22 2016
Storm system passing across the southern portions of the United
States and lifting through the Appalachians this morning keeping
the flow north northeasterly over Central Illinois with plenty of
mid level clouds. Some light snow showers cannot be ruled out in
the extreme SE/Southern portions of Illinois today, well south of
I-70. Another area of echos on radar up in the Chicago area
starting to show some lake effect snow with the NNE winds. Always
something to watch how far south it will get down the I-55
corridor, but for now will leave the forecast dry in the north.
May have to add some flurries later, but so far, the echos are
disintegrating further south. No major updates to the forecast
expected at this time.
&&
.SHORT TERM...(Today)
ISSUED AT 329 AM CST FRI JAN 22 2016
The storm system that will affect the East Coast over the next
several days was gathering strength over western Alabama as of 2am.
The precipitation shield associated with the storm was pushing into
extreme southern Illinois with models continuing to suggest the bulk
of the snow will stay just south of Lawrenceville today. Will
continue to hang on to at least slight chance wording in our far
southeast counties to account for any northward shift in the precip
today, however, forecast soundings and time-height cross sections
showing quite a bit of dry air from 925-800 my layer so if the snow
is able to make it to the surface, it will be on the light side with
the more significant accumulating snowfall remaining south.
Further north, a weak shortwave seen on the water vapor loop over
the Great Lakes will shift southeast today with the main forecast
concern with that feature being a large deck of stratus along and
to the north of the trof axis in addition to some scattered flurries.
May see the lower deck gradually work its way south into the
forecast area during the day today but most of the short term models
indicate any light snow or flurries with the upper wave will remain
to our west and north today. Something to keep an eye on in the
short term with both the HRRR and RAP models indicating the north to
northeasterly flow off of Lake Michigan may push some flurries
southwest to parts of north-central Illinois this afternoon. Not
much of a big diurnal shift in temperatures today due to the cloud
cover with most areas in the upper 20s to lower 30s this afternoon.
.LONG TERM...(Tonight through Thursday)
ISSUED AT 329 AM CST FRI JAN 22 2016
Strong low pressure to deepen and move off the NC coast overnight
with its snow mainly along and se of the Ohio river pulling further
away from southeast IL, while clouds begin to decrease from the nw
during overnight. Breezy north winds to continue tonight especially
in eastern IL closer to strong low pressure near the NC coast. Lows
tonight in the upper teens central IL and lower 20s se of I-70.
With Nor`easter off the mid Atlantic and New England coast Saturday
and Saturday night bringing a major winter storm to mid Atlantic
states and southern New England, quiet weather expected for IL this
weekend. Mostly sunny skies Saturday over central and southeast IL
with surface ridge over the MS river valley by sunset Saturday and
as upper level ridge shifts east into IL by Sunday. Highs mostly in
the lower 30s Saturday with NNW winds keeping it cool. Temps modify
Sunday into the mid 30s to around 40F with increasing south winds
on Sunday along with some increase clouds over central IL.
A storm system off the West Coast to bring an upper level trof east
into IL by Monday evening while weak surface low pressure tracks
from the OK panhandle at sunset Sunday into ne IL by sunday Monday.
Still dry Sunday night with light precipitation spreading east over
IL during the day Monday. 00Z models have trended slower with
arrival of this weather system, so think surface temps will be above
freezing by time precipitation starts. Monday looks warm enough to
support mainly light rain with chance of light snow over northern
CWA Monday morning and far NW CWA by Knox and Stark counties Monday
afternoon with little or no accumulations. Above normal highs Monday
in the upper 30s/lower 40s.
A bit cooler air moves in behind a cold front during Monday night as
light rain changes to light snow before diminishing to flurries and
linger into Tue with upper level trof over the Great lakes and into
IL. Any snowfall amounts appear quite light if they occur Monday
night generally less than a half inch. Highs Tue around 30F northern
CWA to near 35F far se IL along and south of highway 50. Weak high
pressure near IL Wed with dry conditions and partly sunny skies with
highs mostly in the lower 30s. 00Z models have trended further nne
with northern stream short wave/clipper system on Thu where brunt of
light snow chances pass ne of central IL with just slight chances
for central and ne CWA. Temps to modify back into mid to upper 30s
Thu and a few degrees milder next Friday in upper 30s/lower 40s.
&&
.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
ISSUED AT 500 AM CST FRI JAN 22 2016
A band of MVFR, with occasional IFR cigs, was edging slowly south
and southwest this morning and will begin to affect our northern
TAF sites after 15z...and then points further south after 18z.
Low pressure well to our south will take the more significant
snowfall well south of our TAF sites today while the gusty
northeast flow draws some lower clouds south into the area during
the day. Bases of the cigs just to our north were in the 1000 to
2000 foot range over the past couple of hours. Initially, think
those will be the bases of the cigs in our area as it moves in
later this morning or early this afternoon, but with a persistent
dry northeast flow, we may see the cig bases come up a bit to
1500-2000 feet. Forecast soundings not offering much hope of any
improvement thru at least this forecast period with at least MVFR
cigs holding into the overnight hours.
Surface winds will be out of the north to northeast at 10 to 15
kts with occasional gusts up to 23 kts, especially along and east
of the I-55 corridor. Look for northerly winds to diminish to
around 10 kts tonight.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...HJS
SHORT TERM...Smith
LONG TERM...07
AVIATION...Smith
AREA FORECAST DISCUSSION
NWS WICHITA KS
230 PM CST FRI JAN 22 2016
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 228 PM CST FRI JAN 22 2016
FORECAST HIGHLIGHTS: WARMING TREND THIS WEEKEND...SLIGHT CHANCE
OF LIGHT WINTRY PRECIPITATION SUNDAY NIGHT AND MONDAY...COOLER
AGAIN MONDAY AND TUESDAY...WARMING TREND MID- WEEK INTO NEXT
WEEKEND.
DESPITE THE MORE OPTIMISTIC NAM/GFS CLEARING LOW CLOUDS THIS
EVENING...THINKING REALITY WILL BE CLOSER TO THE RAP TONIGHT-
SATURDAY MORNING...WITH WIDESPREAD LOW CLOUDS LINGERING. DECREASED
MIXING WITH APPROACHING SURFACE RIDGE...ALONG WITH NO APPRECIABLE
DOWNGLIDE OR DRY AIR ADVECTION WILL SUPPORT THESE LINGERING LOW
CLOUDS. GIVEN THE LOW CLOUDS...PROBABLY NOT LOOKING AT WIDESPREAD
FOG OVERNIGHT. HOWEVER...GOOD CLOUD TOP COOLING MAY PROMOTE PATCHY
STRATUS BUILD-DOWN FOG POTENTIAL OVER MAINLY SNOW-COVERED AREAS OF
CENTRAL/NORTHERN KANSAS. LOCATIONS FURTHER SOUTH INCLUDING
HUTCHINSON...WICHITA...EL DORADO CANNOT RULE OUT PATCHY FOG...BUT
THREAT SHOULD BE LESS GIVEN LACK OF SNOW-COVER AND/OR COLD GROUND
FOR OPTIMAL STATUS BUILD-DOWN.
WARMING TEMPERATURES WILL COMMENCE SATURDAY AND ESPECIALLY
SUNDAY...AS SOUTHERLY FLOW INCREASES AHEAD OF THE NEXT TROUGH
APPROACHING FROM THE WEST. HIGHS SUNDAY WILL APPROACH THE MID 50S
OVER SOUTHERN KANSAS. SUNDAY LOOKS TO BE FAIRLY
BREEZY/GUSTY...ESPECIALLY EASTERN HALF OF KANSAS.
THE NEXT TROUGH WILL PROGRESS OVER MID-AMERICA SUNDAY NIGHT-
MONDAY. MEGA STORM CURRENTLY MOVING ACROSS THE EASTERN CONUS WILL
LIKELY SHUNT ALL LOW-LEVEL MOISTURE WELL SOUTH THROUGH THE GULF OF
MEXICO...WHICH WILL LIMIT MOISTURE AVAILABILITY FOR THE SUNDAY
NIGHT- MONDAY SYSTEM. CONSEQUENTLY...DESPITE MODEST LIFT...ONLY
LOOKING AT SLIGHT CHANCE TO CHANCE POPS ACROSS WICHITA`S FORECAST
AREA...WITH THE GREATEST POTENTIAL OVER NORTHERN KANSAS...NEBRASKA
AND MISSOURI. PRECIPITATION TYPE WILL BE TRICKY...WITH A MIX OF
LIGHT SNOW AND FREEZING DRIZZLE POSSIBLE. ALL-IN-ALL...EXPECTING
IMPACTS WILL REMAIN LOW WITH THIS NEXT SYSTEM.
ADK
.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 228 PM CST FRI JAN 22 2016
A RETURN TO SEASONABLE TEMPERATURES IS EXPECTED MONDAY-TUESDAY IN
WAKE OF THIS SYSTEM. MONDAY COULD BE A FAIRLY RAW DAY...WITH
STOUT/GUSTY NORTHWEST WINDS AND HIGHS IN THE 30S TO LOW 40S.
ANOTHER WARMING TREND IS EXPECTED FROM MID-WEEK THROUGH THE
WEEKEND...AS MEDIUM RANGE CONSENSUS SUPPORTS BUILDING THICKNESS
FROM THE WEST...TRANSITIONING TO MORE ZONAL FLOW TOWARD THE
WEEKEND. DAYTIME HIGHS SHOULD REACH THE 50S BY THURSDAY...AND
COULD BE PUSHING 60 DEGREES BY FRIDAY.
ADK
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1135 AM CST FRI JAN 22 2016
LOW CLOUDS EXPECTED TO PERSIST ACROSS THE ENTIRE REGION FOR THE
NEXT 24HRS...WITH LIMITED MIXING TO SCOUR THEM OUT. SURFACE RIDGE
AXIS WILL SLIDE SLOWLY EASTWARD INTO EASTERN KANSAS BY LATE
TONIGHT. COULD SEE THE CLOUD HEIGHTS GRADUALLY LOWER AS THE NIGHT
GOES ON WITH SOME POSSIBLE STRATUS BUILD DOWN EFFECTS. THIS MIGHT
REDUCE THE VISIBILITIES FOR LOCATIONS ALONG AND EAST OF THE
SURFACE RIDGE AXIS TOWARDS SATURDAY MORNING.
JAKUB
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 19 42 30 51 / 0 0 0 0
HUTCHINSON 18 41 29 49 / 0 0 0 0
NEWTON 19 40 29 49 / 0 0 0 0
ELDORADO 19 40 30 50 / 0 0 0 0
WINFIELD-KWLD 19 43 31 53 / 0 0 0 0
RUSSELL 19 39 27 45 / 0 0 0 0
GREAT BEND 20 43 28 48 / 0 0 0 0
SALINA 17 36 28 46 / 0 0 0 0
MCPHERSON 18 39 28 48 / 0 0 0 0
COFFEYVILLE 20 40 29 52 / 0 0 0 0
CHANUTE 18 38 28 50 / 0 0 0 0
IOLA 18 37 28 49 / 0 0 0 0
PARSONS-KPPF 19 39 29 51 / 0 0 0 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
1139 AM CST FRI JAN 22 2016
...UPDATED FOR 18Z AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 340 AM CST FRI JAN 22 2016
D-E-E-P UPPER-DECK TROF UNDERGOING CYCLOGENESIS CONTINUED DIGGING
OVER THE AR/LA BORDER DURING THE NIGHT WITH IT`S ATTENDANT SFC LOW
DEVELOPING OVER THE MS/AL BORDER. THIS IS KEEPING ALL OF CENTRAL &
EASTERN KS IN A "MODERATE" N/NE REGIME. A SOMEWHAT UNORTHODOX DRY
SLOT IS KNIFING ALMOST DUE S ACROSS EASTERN KS THAT`LL TEAM WITH
SNOW FIELD TO ENABLE TEMPERATURES ACROSS NORTHEAST & EAST-CENTRAL
KS TO NOSEDIVE EARLY THIS MORNING THUS SHARPENING THE E-W GRADIENT
EARLY THIS MORNING.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 340 AM CST FRI JAN 22 2016
TODAY & TONIGHT:
THE GREATEST ISSUE IS HOW THE STRATUS WILL BEHAVE. THE LOWER-DECK
CYCLONE...THAT IS SITUATED OVER THE MS/AL BORDER VERY EARLY THIS
MORNING...SHOULD GET FORCED SLOWLY E/NE ACROSS THE AL/TN BORDER
THIS AFTERNOON AS A HIGH-AMPLITUDE RIDGE PUNCHES NE FROM AZ/NM
TOWARD THE NORTHERN PLAINS. THE NAM...RUC & HRRR ALL KEEP A SHARP
900-850MB INVERSION OVER ALL OF THE CWA THRU LATE THIS AFTERNOON.
THE NAM SHARPENS THE INVERSION TONIGHT WHICH WOULD LIKELY KEEP THE
NEIGHBORHOOD STRATIFIED THIS EVENING. AS SUCH WILL HAVE MOST...IF
NOT ALL...OF KICT COUNTRY UNDER A LOW OVERCAST THRU EARLY THIS
EVENING. THIS OF COURSE WOULD HAVE RAMIFICATIONS ON TEMPERATURES.
(ESPECIALLY ALONG THE NE CORRIDOR.) FOR THE MOST PART HAVE
FOLLOWED THE CONSALL & SUPERBLEND SOLUTIONS. WITH THE AFORE-
MENTIONED POSITIVELY-TILTED RIDGE AXIS SHIFTING E SKIES SHOULD
CLEAR W-E TO ENABLE TEMPERATURES TO TUMBLE. DID UNDERCUT GUIDANCE
ALONG NE SECTOR WHERE SNOW FIELD WOULD NO DOUBT ASSIST THE
CLEARING SKIES & WINDS THAT`LL BECOME LIGHT & VARIABLE WITH THE
TEMPERATURE DROP.
THIS WEEKEND:
WARMER WEATHER IS STILL SCHEDULED TO ARRIVE AS THE ABOVE-MENTIONED
MID-UPPER RIDGE DEAMPLIFIES & SPREADS E ACROSS THE CENTRAL THIRD
OF THE CONUS SAT & SAT NIGHT. A DEEP...COMPACT CYCLONE THAT HAS
BEEN APPROACHING THE NORTHERN CA/OR COAST DURING THE NIGHT WILL
QUICKLY TRANSITION INTO AN OPEN WAVE AS IT CROSSES AS IT CROSSES
THIS SECTION OF THE COAST LATE TONIGHT & SAT. IT`LL GRADUALLY
RESTRENGTHEN AS IT CROSSES THE ROCKIES ON SUN THEN ACROSS THE
CENTRAL & SOUTHERN PLAINS SUNDAY NIGHT. THIS WOULD SWEEP A COLD
FRONT SE ACROSS KS SUNDAY NIGHT. SOME POST FRONTAL PRECIPITATION
(LIGHT SNOW) IS POSSIBLE ACROSS CENTRAL KS LATE SUNDAY NIGHT. THE
RAPIDLY PROGRESSIVE PATTERN SHOULD KEEP CHANCES FOR ACCUMULATION
IN CHECK.
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 340 AM CST FRI JAN 22 2016
MON:
AS THE CONTINUALLY STRENGTHENING UPPER-DECK WAVE SURGES E TOWARD
THE MS VALLEY ALL PRECIPITATION SHOULD QUICKLY END. TEMPERATURE
PROFILES DEPICT PRIMARILY LIGHT RAIN FOR SOUTHEAST KS.
MON NIGHT-THU:
A CYCLONE WILL APPROACH HUDSON BAY MON NIGHT & RAPIDLY INTENSIFY
AS IT CROSSES HUDSON BAY TUE & TUE NIGHT. THE CYCLONE WILL KICK A
S-H-A-R-P POSITIVELY-TILTED MID-UPPER LONG-WAVE SE ACROSS THE
GREAT PLAINS TUE NIGHT...HOWEVER IT`S SFC COHORT APPEARS TO KEEP
THE CENTRAL & SOUTHERN PLAINS IN A PREDOMINANTLY NW COMPONENT TO
KEEP TEMPERATURES ON THE MILD SIDE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1135 AM CST FRI JAN 22 2016
LOW CLOUDS EXPECTED TO PERSIST ACROSS THE ENTIRE REGION FOR THE
NEXT 24HRS...WITH LIMITED MIXING TO SCOUR THEM OUT. SURFACE RIDGE
AXIS WILL SLIDE SLOWLY EASTWARD INTO EASTERN KANSAS BY LATE
TONIGHT. COULD SEE THE CLOUD HEIGHTS GRADUALLY LOWER AS THE NIGHT
GOES ON WITH SOME POBBILE STRATUS BUILD DOWN EFFECTS. THIS MIGHT
REDUCE THE VISIBILITIES FOR LOCATIONS ALONG AND EAST OF THE
SURFACE RIDGE AXIS TOWARDS SATURDAY MORNING.
JAKUB
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 32 17 43 28 / 10 0 0 0
HUTCHINSON 30 15 41 27 / 0 0 0 0
NEWTON 29 15 39 27 / 10 0 0 0
ELDORADO 31 15 40 28 / 10 0 0 0
WINFIELD-KWLD 33 17 42 29 / 10 0 0 0
RUSSELL 30 17 41 26 / 0 0 0 0
GREAT BEND 31 17 43 27 / 0 0 0 0
SALINA 28 13 34 27 / 0 0 0 0
MCPHERSON 29 14 39 27 / 0 0 0 0
COFFEYVILLE 34 18 40 28 / 0 0 0 0
CHANUTE 31 16 38 27 / 0 0 0 0
IOLA 31 16 37 27 / 0 0 0 0
PARSONS-KPPF 33 17 39 27 / 0 0 0 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
National Weather Service Paducah KY
1206 PM CST FRI JAN 22 2016
.UPDATE...
Issued at 552 AM CST FRI JAN 22 2016
The snow has come to an end over much of southeast Missouri with
exception of New Madrid...Mississippi...and Scott counties...so we
have expired/cancelled the Warning and Advisory for the remainder
of our Missouri counties.
Latest radar trends are pushing the north edge of the snow shield
a county or so northwest of the Winter Storm Warning area. We do
not expect this to last long enough for 4+" to accumulate, so we
have continued the Advisory for Scott, Alexander and Pulaski through
21Z...and expanded it northeast through Gallatin and Posey
counties. There may be a dusting in the counties bordering the
Advisory in southern Illinois and southwest Indiana, but not
enough to be much of a problem, especially with the gusty north
winds blowing it around.
All that`s left now is to see just how much snow this "West
Kentucky Blizzard" can dump.
The AVIATION section has been updated for the 12Z TAF issuance.
&&
.SHORT TERM...(Today through Sunday)
Issued at 352 AM CST FRI JAN 22 2016
According to dual pol radar data it appears that much of the
Warning area has changed over to snow, with the exception of
Calloway county eastward along the Tennessee border. A change over
to all snow is expected over those areas by 12Z. The Winter Storm
Warning is looking pretty good, and no changes are planned at
this time. Snow amounts over much of west Kentucky may be just a
bit higher with a max now of around 12" in Muhlenberg, Christian
and Todd counties.
The problem areas for the snow forecast continue to be the
northwest periphery of the existing warning area. The Evansville
area southwest to Hardin county may not quite reach Warning
criteria of 4", but there may be an area of more advisory level
snows from Alexander county through Johnson and into Saline and
Gallatin counties. Radar is currently showing some increase in
that region and recent HRRR runs are showing the precipitation
shield reaching those areas now. Not sure if it will last long
enough to warrant an Advisory, so for now will just keep an eye
out for observations from those regions and adjust as needed.
Latest radar trends indicate that southeast Missouri outside of
New Madrid and Mississippi counties has dried out as expected.
Will let the Warning and Advisory expire as scheduled at 12Z. May
need to extend Alexander and Pulaski for awhile, but will make
that decision near 12Z. Hopefully, we will have enough
observations by then to decide if the Advisory needs to be
expanded to the northeast any at all.
It appears that much of the measurable precipitation will be done
by 00Z, but will leave the 06Z expiration of the primary portion
of the Warning. However, we will likely be cancelling it in chunks
this afternoon, as the snow comes to an end from west to east.
Skies will clear Saturday, but temperatures will struggle to climb
above freezing, especially over the snowpack. The surface high
will settle over the region Saturday night, so some single digit
lows are expected, especially over the Pennyrile. Wouln`t be
surprised if a few locations approach 0. South winds will try to
bring a warm up on Sunday, but with the snowpack hanging around,
it may be muted compared to the MAV guidance.
.LONG TERM...(Sunday Night through Thursday)
Issued at 352 AM CST FRI JAN 22 2016
By Sunday night, an upper level ridge will be centered overhead with
sfc high pressure continuing to move east of the area. South winds
at the surface will continue to pick up as a storm system over the
central Plains moves east northeast. By 12Z Monday, a sfc low will
be located over the KS/MO border. Throughout the day on Monday, the
sfc low will move northeast toward the western Great Lakes region.
As this occurs, a cold front will move across our area from west to
east. As has been the case for the last few days...models are not
showing too much QPF with this system, as the best moisture is
confined to the north with the actual sfc low. However, we will
continue to maintain low chance POPS with the FROPA. Soundings and
time height charts indicate temperatures are warm enough for
precipitation to fall as rain, at least during the day.
Heading into Monday evening, models differ a bit on the timing of
when exactly the front will clear the CWA. However, will continue to
linger precipitation into the evening/overnight hours, however
believe that any lingering activity should probably be mainly during
the evening. Low level temperature profiles indicate that there
could be a rain/snow mix up in our northern counties. This blends
well with neighboring offices to our north.
Since moisture seems to be lacking on Tuesday, despite the fact that
an upper level trough will be moving through the area, will only
keep low POPS for the eastern sections. Any moisture will be
confined to the low levels, centered around 925mb, so some flurries
would be possible if anything occurred at all.
High pressure builds into the area Tuesday night into Wednesday
providing dry weather. A clipper type system approaches us from the
northwest on Wednesday night into Thursday but should only bring us
some clouds.
&&
.AVIATION...
Issued at 1206 PM CST FRI JAN 22 2016
VFR CONDITIONS AT KCGI THROUGH 23Z, WITH CIGS THEN DROPPING TO
MVFR, IMPROVING BACK TO VFR AFTER 12Z. AT KPAH, EXPECT MVFR/LOW
VFR CIGS, WITH MVFR/IFR VSBYS WITH LIGHT SNOW THROUGH 22Z. AFTER
22Z, MVFR CIGS, AND MVFR VSBYS IMPROVING TO VFR VSBYS EXPECTED.
FOR KEVV/KOWB, MVFR TO IFR CONDITIONS EXPECTED WITH LIGHT SNOW
THROUGH 00Z-02Z. AFTER 02Z, MVFR CIGS WITH VSBYS IMPROVING TO VFR
EXPECTED, WITH CIGS IMPROVING TO VFR BY 13-15Z. AT ALL SITES, N/NW
WINDS NEAR 15 KTS WITH 25 KT GUSTS WILL DECREASE AFTER 00Z.
&&
.PAH Watches/Warnings/Advisories...
IL...Winter Weather Advisory until 3 PM CST this afternoon for ILZ086-
087-089-092-093.
Winter Storm Warning until midnight CST tonight for ILZ090-091-
094.
MO...Winter Weather Advisory until 3 PM CST this afternoon for MOZ111.
Winter Storm Warning until midnight CST tonight for MOZ112-114.
IN...Winter Weather Advisory until 3 PM CST this afternoon for INZ085.
Winter Storm Warning until midnight CST tonight for INZ086>088.
KY...Winter Storm Warning until midnight CST tonight for KYZ001>022.
&&
$$
UPDATE...DRS
SHORT TERM...DRS
LONG TERM...CW
AVIATION...RST
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
558 PM EST FRI JAN 22 2016
.SYNOPSIS...
LOW PRESSURE WILL YIELD WIDESPREAD OVER THE MID ATLANTIC AND WILL
PASS SOUTH AND EAST OF PITTSBURGH. THE HEAVIEST SNOW IS EXPECTED
SOUTH AND EAST OF PITTSBURGH. THE SYSTEM WILL PULL OFF TO THE EAST
LATE SATURDAY...WITH HIGH PRESSURE BUILDING OVERHEAD ON SUNDAY.
WARMER WEATHER IS FORECAST MONDAY AND TUESDAY WITH TEMPERATURES
REACHING INTO THE 40S.
&&
.NEAR TERM /THROUGH SATURDAY/...
UPDATED FORECAST TO ACCOUNT FOR BAND OF LIGHT SNOW CAUSED BY
H8-H5 DEFORAMTION. THIS SHOULD NOT MOVE MUCH MORE NORTH DURING
THE EVENING AND IN FACT EXPECT A WEAKENING TREND AS EVIDENT BY
RECENT SCANS FROM KPBZ WSR-88D. INITIAL BAND YIELDED 1-4" INCHES
FROM WESTMORELAND SOUTHEAST TO MONROE COUNTY OHIO. SNOWFALL
AMOUNTS SO FAR IN THE HIGHER ELEVATIONS OF NORTHERN WV AND WESTERN
MD ARE ALREADY APPROACHING 12 HOUR WARNING CRITERIA OF SIX INCHES
AND WITH STRONG H6-H5 EPV ILLUSTRATES PROJECTED TO CROSS BETWEEN
6-10PM WITH 1-2" PER HOUR SNOW RATES AS LIKELY.
ADJUSTED STORM TOTAL AMOUNTS SLIGHTLY OVER MOUNTAIN COUNTIES WHILE
LOWERING TEMPS INTO THE LOWER TEENS...OTHERWISE REMAINDER OF THE
FORECAST ON TRACK. PREVIOUS DISCUSSION FOLLOWS...
MODEL TRENDS CONTINUE TO SUGGEST A SLIGHTLY NORTHERN TRACK WITH
THE UPPER LOW...AND THUS THE TRACK AND DEVELOPMENT OF THE COASTAL
LOW OVERNIGHT. THIS HAS BEEN REFLECTED IN THE CURRENT
FORECAST...WITH A SLIGHT UPTICK IN AMOUNTS ACROSS THE REGION BUT
MOST NOTABLY TO THE AREAS SOUTH OF I-70. THE NAM STILL SEEMS TO
BE THE MOST BULLISH WITH SNOW AMOUNTS ACROSS THE REGION BUT DOES A
GREAT JOB OF PORTRAYING THE DEFORMATION ZONE THAT IS ANTICIPATED
TO DEVELOP ACROSS A PORTION OF THE REGION TONIGHT/SATURDAY
MORNING. WHERE THIS EVENTUAL BAND OF SNOW/TROWAL WILL SET UP AND
PRODUCE THE BEST SNOW FALL RATES/AMOUNTS...STILL REMAINS IN
QUESTION BUT....GENERALLY ANTICIPATE OVER A FOOT OF SNOW FROM
WETZEL-GREENE-FAYETTE-WESTMO RIDGES AND ALMOST 2 FEET (OR MORE) IN
THE PRESTON...TUCKER...AND GARRETT.
ALL IN ALL VERY MINUTE CHANGES TO THE FORECAST...WITH ENHANCEMENTS
MADE BASED ON THE LATEST QPF FORECAST FROM WPC. AS WAS MENTIONED
PREVIOUSLY...SNOW RATIOS SHOULD REMAIN AT OR BELOW CLIMATOLOGY IN
THE 10-12:1 RANGE THROUGH THE EVENT...IT WILL BE THE MESOSCALE
BANDS OF SNOW THAT WILL ENHANCE THE SNOW TOTALS ACROSS THE REGION.
IN REGARD TO THE WIND...GUSTS TO 30MPH MAY BE POSSIBLE IN THE
HIGHER TERRAIN...ESPECIALLY AS THE LOW LEVEL JET RAMPS UP THIS
EVENING. THIS COULD CAUSE BLOWING SNOW AND VISIBILITY CONCERNS IN
THOSE LOCATIONS.
AS THE COASTAL LOW MOVES OFF TO THE EAST...SNOW WILL LINGER WHERE
THE DEFORMATION BAND/TROWAL REMAINS...BUT SHOULD END FROM WEST TO
EAST BY LATE SATURDAY AFTERNOON. THE HRRR HAS SNOW ENDING FOR
MOST OF ALLEGHENY COUNTY AND THE AREAS FROM ZZV-PIT-DUJ BY EARLY
MORNING...BUT WILL LEAVE THE CURRENT PRODUCT END TIMES AS IS FOR
NOW.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
HIGH PRESSURE WILL START TO BUILD OVERHEAD SATURDAY NIGHT AS THE
SYSTEM MOVES NORTHEASTWARD. UPPER LEVEL FLOW WILL BE BACKING TO
THE NORTHEAST AND WITH SATURATION IN THE DENDRITIC GROWTH
ZONES...SOME LIGHT SNOW MAY BE POSSIBLE UNTIL SUNDAY MORNING IN
THE RIDGES. ELSEWHERE...IT APPEARS SKIES WILL CLEAR OUT.
TEMPERATURES WERE KEPT NEAR A BLEND OF GUIDANCE FOR LOWS...BUT
COULD BE COLDER IF WE FULLY DECOUPLE.
FLATTENING RIDGE ALONG AND SURFACE HIGH PRESSURE ARE IN CONTROL
ON SUNDAY...WITH DRY WEATHER AND A SLIGHT MODERATION IN
TEMPERATURES. SOME MID/HI CLOUDS WILL RETURN DURING THE AFTERNOON.
THIS SLOW CLOUD INCREASE WILL CONTINUE THROUGH SUNDAY NIGHT AND
MONDAY AS FLOW TURNS SOUTHWEST AHEAD OF THE NEXT FRONTAL SYSTEM. A
FEW RAIN OR SNOW SHOWERS MAY ARRIVE IN OUR WESTERN COUNTIES BY 00Z
TUESDAY...BUT MOST WILL REMAIN DRY THROUGH THAT TIME. THE
SOUTHWEST FLOW WILL HELP TO PUSH TEMPERATURES TO NEAR OR EVEN
SLIGHTLY ABOVE NORMAL BY MONDAY.
NOT MAJOR CHANGES TO THE GRIDDED FORECAST DURING THIS PERIOD.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
FRONTAL BOUNDARY PEGGED TO MOVE THROUGH DURING THE DAY TUESDAY.
PRECIPITATION MAY BEGIN AS LIGHT SNOW SUNDAY NIGHT...BUT SHOULD
CHANGE TO RAIN WITH TIME. CANNOT RULE OUT ISOLATED POCKETS OF FZRA
BUT CHANCES ARE TOO LOW TO INCLUDE AT THIS TIME. MOST AREAS SHOULD
BE ABLE TO CHANGE TO RAIN TUESDAY...BEFORE TURNING BACK TO SNOW
BEHIND THE FRONT. PRECIPITATION OVERALL SHOULD BE REASONABLY LIGHT.
A BRIEF DRY INTERLUDE WEDNESDAY NIGHT INTO THURSDAY WILL BE FOLLOWED
BY ANOTHER SYSTEM TO CLOSE OUT THE WORK WEEK.
THE GRIDS DURING THIS PERIOD WERE MOSTLY CONSTRUCTED BY USING THE
SUPERBLEND GUIDANCE.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
SNOW WILL START TO OVERSPREAD MANY OF THE TERMINALS THIS
AFTERNOON...WITH THE STEADIER SNOW REACHING PIT/ZZV/IDI BY OR
AROUND SUNSET. RESTRICTIONS WILL SPREAD NORTH WITH TIME. HAVE A
PERIOD OF IFR OR WORSE AT ALL SITES SAVE FOR FKL/DUJ...WHICH
SHOULD REMAIN ON THE OUTER FRINGES OF THE SIGNIFICANT SNOWFALL.
LONGEST LASTING AND MOST SEVERE RESTRICTIONS WILL BE AT
MGW...WITH A LONG PERIOD OF LIFR FROM 00Z THROUGH AT LEAST
SATURDAY MORNING. MODERATE TO HIGH CONFIDENCE ON THE CATEGORY
FORECASTS...BUT A LITTLE LOWER CONFIDENCE ON TIMING...WHICH WILL
LIKELY NEED TWEAKING AS THE EVENT UNFOLDS. NE WIND GUSTS OF 15 TO
25 KNOTS WILL BECOME COMMON TONIGHT...WHICH MAY LEAD TO SOME
BLOWING AND DRIFTING SNOW IN PORTIONS OF SW PA AND NORTHERN WV.
IMPROVEMENT WILL BEGIN TOWARDS THE VERY END OF THE TAF PERIOD.
.OUTLOOK.../SATURDAY AFTERNOON THROUGH TUESDAY/...
RESTRICTIONS WILL CONTINUE TO WANE THROUGH SATURDAY NIGHT AS THE
SYSTEM PULLS AWAY...WITH VFR RETURNING ON SUNDAY. COLD FRONT WILL
BRING POSSIBLE RESTRICTIONS TUESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WINTER STORM WARNING UNTIL 1 AM EST SUNDAY FOR MDZ001.
OH...WINTER WEATHER ADVISORY UNTIL 7 PM EST SATURDAY FOR OHZ049-050-
057>059-068.
WINTER STORM WARNING UNTIL 7 PM EST SATURDAY FOR OHZ069.
PA...WINTER WEATHER ADVISORY UNTIL 7 PM EST SATURDAY FOR PAZ021-023-
029-073.
WINTER STORM WARNING UNTIL 1 AM EST SUNDAY FOR PAZ031-074>076.
WV...WINTER WEATHER ADVISORY UNTIL 7 PM EST SATURDAY FOR WVZ002-003.
WINTER STORM WARNING UNTIL 1 AM EST SUNDAY FOR WVZ012-021-
509>514.
WINTER STORM WARNING UNTIL 7 PM EST SATURDAY FOR WVZ004.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
349 PM EST FRI JAN 22 2016
.SYNOPSIS...
STRONG LOW PRESSURE WILL SPREAD SNOW FROM SOUTH TO NORTH ACROSS
THE REGION THIS AFTERNOON AND EVENING AND CONTINUE INTO SATURDAY.
THE HEAVIEST SNOW IS EXPECTED SOUTH AND EAST OF PITTSBURGH. THE SYSTEM
WILL PULL OFF TO THE EAST LATE SATURDAY...WITH HIGH PRESSURE BUILDING
OVERHEAD ON SUNDAY.
&&
.NEAR TERM /THROUGH SATURDAY/...
FIRST SNOW BAND...ASSOCIATED WITH MIDLEVEL FRONTOGENESIS...CONTINUES
TO MOVE NORTHEASTWARD A BIT FASTER THAN PREVIOUSLY FORECAST. SNOW
RATES NEAR AN INCH AN HOUR WERE REPORTED FURTHER SOUTH...AND THIS
MAY CONTINUE AS THE BAND SHIFTS NORTHWARD. HAVE ADJUSTED THE POPS
AND THE AMOUNTS PER THE LATEST OBSERVATIONS FROM SPOTTERS AND
RADAR DATA THROUGH THE REST OF THE AFTERNOON...WITH HIGH QPF
EXPECTED NOW THROUGH 7PM...LEADING TO SLIGHTLY HIGHER AMOUNTS OVER
THE HIGHER TERRAIN...STORM TOTAL.
MODEL TRENDS CONTINUE TO SUGGEST A SLIGHTLY NORTHERN TRACK WITH
THE UPPER LOW...AND THUS THE TRACK AND DEVELOPMENT OF THE COASTAL
LOW OVERNIGHT. THIS HAS BEEN REFLECTED IN THE CURRENT
FORECAST...WITH A SLIGHT UPTICK IN AMOUNTS ACROSS THE REGION BUT
MOST NOTABLY TO THE AREAS SOUTH OF I-70. THE NAM STILL SEEMS TO
BE THE MOST BULLISH WITH SNOW AMOUNTS ACROSS THE REGION BUT DOES A
GREAT JOB OF PORTRAYING THE DEFORMATION ZONE THAT IS ANTICIPATED
TO DEVELOP ACROSS A PORTION OF THE REGION TONIGHT/SATURDAY
MORNING. WHERE THIS EVENTUAL BAND OF SNOW/TROWAL WILL SET UP AND
PRODUCE THE BEST SNOW FALL RATES/AMOUNTS...STILL REMAINS IN
QUESTION BUT....GENERALLY ANTICIPATE OVER A FOOT OF SNOW FROM
WETZEL-GREENE-FAYETTE-WESTMO RIDGES AND ALMOST 2 FEET (OR MORE) IN
THE PRESTON...TUCKER...AND GARRETT.
ALL IN ALL VERY MINUTE CHANGES TO THE FORECAST...WITH ENHANCEMENTS
MADE BASED ON THE LATEST QPF FORECAST FROM WPC. AS WAS MENTIONED
PREVIOUSLY...SNOW RATIOS SHOULD REMAIN AT OR BELOW CLIMATOLOGY IN
THE 10-12:1 RANGE THROUGH THE EVENT...IT WILL BE THE MESOSCALE
BANDS OF SNOW THAT WILL ENHANCE THE SNOW TOTALS ACROSS THE REGION.
IN REGARD TO THE WIND...GUSTS TO 30MPH MAY BE POSSIBLE IN THE
HIGHER TERRAIN...ESPECIALLY AS THE LOW LEVEL JET RAMPS UP THIS
EVENING. THIS COULD CAUSE BLOWING SNOW AND VISIBILITY CONCERNS IN
THOSE LOCATIONS.
AS THE COASTAL LOW MOVES OFF TO THE EAST...SNOW WILL LINGER WHERE
THE DEFORMATION BAND/TROWAL REMAINS...BUT SHOULD END FROM WEST TO
EAST BY LATE SATURDAY AFTERNOON. THE HRRR HAS SNOW ENDING FOR
MOST OF ALLEGHENY COUNTY AND THE AREAS FROM ZZV-PIT-DUJ BY EARLY
MORNING...BUT WILL LEAVE THE CURRENT PRODUCT END TIMES AS IS FOR
NOW.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
HIGH PRESSURE WILL START TO BUILD OVERHEAD SATURDAY NIGHT AS THE
SYSTEM MOVES NORTHEASTWARD. UPPER LEVEL FLOW WILL BE BACKING TO
THE NORTHEAST AND WITH SATURATION IN THE DENDRITIC GROWTH
ZONES...SOME LIGHT SNOW MAY BE POSSIBLE UNTIL SUNDAY MORNING IN
THE RIDGES. ELSEWHERE...IT APPEARS SKIES WILL CLEAR OUT.
TEMPERATURES WERE KEPT NEAR A BLEND OF GUIDANCE FOR LOWS...BUT
COULD BE COLDER IF WE FULLY DECOUPLE.
FLATTENING RIDGE ALONG AND SURFACE HIGH PRESSURE ARE IN CONTROL
ON SUNDAY...WITH DRY WEATHER AND A SLIGHT MODERATION IN
TEMPERATURES. SOME MID/HI CLOUDS WILL RETURN DURING THE AFTERNOON.
THIS SLOW CLOUD INCREASE WILL CONTINUE THROUGH SUNDAY NIGHT AND
MONDAY AS FLOW TURNS SOUTHWEST AHEAD OF THE NEXT FRONTAL SYSTEM. A
FEW RAIN OR SNOW SHOWERS MAY ARRIVE IN OUR WESTERN COUNTIES BY 00Z
TUESDAY...BUT MOST WILL REMAIN DRY THROUGH THAT TIME. THE
SOUTHWEST FLOW WILL HELP TO PUSH TEMPERATURES TO NEAR OR EVEN
SLIGHTLY ABOVE NORMAL BY MONDAY.
NOT MAJOR CHANGES TO THE GRIDDED FORECAST DURING THIS PERIOD.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
FRONTAL BOUNDARY PEGGED TO MOVE THROUGH DURING THE DAY TUESDAY.
PRECIPITATION MAY BEGIN AS LIGHT SNOW SUNDAY NIGHT...BUT SHOULD
CHANGE TO RAIN WITH TIME. CANNOT RULE OUT ISOLATED POCKETS OF FZRA
BUT CHANCES ARE TOO LOW TO INCLUDE AT THIS TIME. MOST AREAS SHOULD
BE ABLE TO CHANGE TO RAIN TUESDAY...BEFORE TURNING BACK TO SNOW
BEHIND THE FRONT. PRECIPITATION OVERALL SHOULD BE REASONABLY LIGHT.
A BRIEF DRY INTERLUDE WEDNESDAY NIGHT INTO THURSDAY WILL BE FOLLOWED
BY ANOTHER SYSTEM TO CLOSE OUT THE WORK WEEK.
THE GRIDS DURING THIS PERIOD WERE MOSTLY CONSTRUCTED BY USING THE
SUPERBLEND GUIDANCE.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
SNOW WILL START TO OVERSPREAD MANY OF THE TERMINALS THIS
AFTERNOON...WITH THE STEADIER SNOW REACHING PIT/ZZV/IDI BY OR
AROUND SUNSET. RESTRICTIONS WILL SPREAD NORTH WITH TIME. HAVE A
PERIOD OF IFR OR WORSE AT ALL SITES SAVE FOR FKL/DUJ...WHICH
SHOULD REMAIN ON THE OUTER FRINGES OF THE SIGNIFICANT SNOWFALL.
LONGEST LASTING AND MOST SEVERE RESTRICTIONS WILL BE AT
MGW...WITH A LONG PERIOD OF LIFR FROM 00Z THROUGH AT LEAST
SATURDAY MORNING. MODERATE TO HIGH CONFIDENCE ON THE CATEGORY
FORECASTS...BUT A LITTLE LOWER CONFIDENCE ON TIMING...WHICH WILL
LIKELY NEED TWEAKING AS THE EVENT UNFOLDS. NE WIND GUSTS OF 15 TO
25 KNOTS WILL BECOME COMMON TONIGHT...WHICH MAY LEAD TO SOME
BLOWING AND DRIFTING SNOW IN PORTIONS OF SW PA AND NORTHERN WV.
IMPROVEMENT WILL BEGIN TOWARDS THE VERY END OF THE TAF PERIOD.
.OUTLOOK.../SATURDAY AFTERNOON THROUGH TUESDAY/...
RESTRICTIONS WILL CONTINUE TO WANE THROUGH SATURDAY NIGHT AS THE
SYSTEM PULLS AWAY...WITH VFR RETURNING ON SUNDAY. COLD FRONT WILL
BRING POSSIBLE RESTRICTIONS TUESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WINTER STORM WARNING UNTIL 1 AM EST SUNDAY FOR MDZ001.
OH...WINTER WEATHER ADVISORY UNTIL 7 PM EST SATURDAY FOR OHZ049-050-
057>059-068.
WINTER STORM WARNING UNTIL 7 PM EST SATURDAY FOR OHZ069.
PA...WINTER WEATHER ADVISORY UNTIL 7 PM EST SATURDAY FOR PAZ021-023-
029-073.
WINTER STORM WARNING UNTIL 1 AM EST SUNDAY FOR PAZ031-074>076.
WV...WINTER WEATHER ADVISORY UNTIL 7 PM EST SATURDAY FOR WVZ002-003.
WINTER STORM WARNING UNTIL 1 AM EST SUNDAY FOR WVZ012-021-
509>514.
WINTER STORM WARNING UNTIL 7 PM EST SATURDAY FOR WVZ004.
&&
$$
AREA FORECAST DISCUSSION
NWS JACKSON MS
1011 AM CST FRI JAN 22 2016
.UPDATE...COLD CORE SYSTEM PULLING AWAY RAPIDLY TO THE NE. WILL
REPLACE WINTER STORM WARNING WITH AN ADVISORY AS ANY REMAINING WINTRY
PRECIP WILL BE LIGHT AND NOT PLAY MUCH OF A ROLE IN ADDITIONAL
ACCUMULATION. WITH THE DYNAMIC WEATHER TODAY...MADE ADJUSTMENTS TO
JUST ABOUT EVERY OTHER GRID TO REFLECT CURRENT TRENDS IN
WX/TEMP/DEWPOINT AND WIND. CONTINUED WIND ADVISORY FOR THE DELTA FOR
THE MOMENT...BUT THAT MAY HAVE TO CANCEL EARLY AS WINDS RELAX AS THE
SYSTEM PULLS FURTHER AWAY./26/
&&
.AVIATION...IFR TO MVFR CEILINGS WILL BE AN ISSUE AT MOST SITES
THROUGH MOST OF THE DAY ON THE BACKSIDE OF A DEPARTING LOW PRESSURE
SYSTEM. IN ADDITION...OCCASIONAL FLURRIES FROM MAINLY ALONG AND
NORTH OF I-20 WILL LIMIT VISIBILITIES DOWN TO 3 TO 5 MILES AT TIMES.
NORTH TO NORTHWEST WINDS WILL BE STRONG AND QUITE GUSTY...ESPECIALLY
WEST OF INTERSTATE 55. CLOUDS AND FLURRIES WILL TRY TO CLEAR OUR
FROM THE WEST/SOUTHWEST LATER THIS AFTERNOON AND INTO THIS
EVENING...BUT WE STILL EXPECT THE POTENTIAL FOR AT LEAST SCATTERED
CEILING PROBLEMS TO CONTINUE INTO TOMORROW MORNING. /BB/
&&
.PREV DISCUSSION... /ISSUED 411 AM CST FRI JAN 22 2016/
..WINTER WEATHER REMAINS POSSIBLE OVER MAINLY NORTHERN PORTIONS OF
THE ARKLAMISS TODAY...
DISCUSSION...TODAY AND TONIGHT...A WINTER STORM IS DEVELOPING THIS
MORNING OVER PORTIONS OF THE ARKLAMISS DELTA REGION...BUT THERE IS
REASON TO BELIEVE THAT SNOW AMOUNTS COULD BE A LITTLE LESS THAN
EXPECTED BASED ON CURRENT TRENDS. TWO CENTERS OF GREATER LIFT
ASSOCIATED WITH THE UPPER LOW ARE RESULTING IH SIGNIFICANT
PRECIPITATION...ONE OVER THE LOWER DELTA REGION AND THE OTHER OVER
CENTRAL/EASTERN ARKANSAS INTO NW MS. IT IS THE LATTER PRECIP AREA
THAT IS OF GREATEST CONCERN AS IT IS TENDING TO STAY NORTH OF THE
FORECAST AREA. MEANWHILE THE AREA OVER THE LOWER DELTA REGION IS ON A
PACE TO STAY AHEAD THE PRECIP TRANSITION ZONE MEANING LESS CHANCE FOR
ACCUMULATING SNOW. MOREOVER THE HRRR HAS BEEN RATHER INSISTENT IN
SHOWING QUICKER DISSIPATION OF PRECIP THIS MORNING AS THE UPPER LOW
SHIFTS EAST. ADDING ALL OF THIS UP WOULD SUGGEST LESSER SNOW
AMOUNTS...BUT AM NOT NEARLY CONFIDENT ENOUGH TO DOWNGRADE PRODUCTS AS
IT WILL ONLY TAKE A ONE-TWO HOUR BURST OF HEAVIER SNOW TO CREATE
IMPACTS. FOR NOW WILL HOLD THE COURSE BUT DON`T BE SURPRISED IF THERE
ARE CHANGES IN THE PRODUCTS LATER THIS MORNING.
OTHERWISE...THE STRONG COLD ADVECTION REGIME IS RIGHT ON TRACK WITH
A CONSIDERABLE AMOUNT OF FLURRIES/DRIZZLE AND EVEN FREEZING DRIZZLE
POSSIBLE FOR MOST OF TODAY INTO THE EVENING FOR LOCATIONS GENERALLY
ALONG AND NORTH OF THE I-20 CORRIDOR. STRONG NORTHWEST/NORTHERLY LOW
LEVEL FLOW HAS DEVELOPED AND WILL CONTINUE THE WIND ADVISORY IN THE
DELTA REGION. LOOK FOR TEMPERATURES TO FALL WELL INTO THE 20S
OVERNIGHT. /EC/
SATURDAY THROUGH NEXT THURSDAY...THE SURFACE LOW WILL
CONTINUE TO LIFT NORTHEAST UP THE EAST COAST AS THE WESTERN
PERIPHERY OF THE UPPER TROUGH EXITS THE REGION SATURDAY. CLOUDS
SHOULD EXIT THE CENTRAL AND EASTERN PORTIONS OF THE FORECAST AREA
SATURDAY MORNING AS HIGH PRESSURE BUILDS INTO THE REGION. UNDER
MOSTLY SUNNY SKIES SATURDAY AFTERNOON AND BREEZY NORTHERLY WINDS...
HIGHS SATURDAY AFTERNOON WILL RANGE FROM THE MID 30S NORTH TO MID
40S SOUTH. THESE COLD TEMPERATURES...COMBINED WITH NORTHERLY WINDS
BETWEEN 10-15 MPH AND GUSTING UP TO 20 MPH AT TIMES THROUGH MID-
AFTERNOON...WILL YIELD WIND CHILLS FROM THE MID 20S TO UPPER 30S
SATURDAY AFTERNOON. CLEAR SKIES AND LIGHT TO CALM WINDS ARE
EXPECTED SATURDAY NIGHT AS A SURFACE HIGH SHIFTS OVER THE REGION.
THIS WILL CAUSE OVERNIGHT LOWS TO PLUMMET INTO THE LOW TO MIDDLE 20S
AREAWIDE.
A BRIEF WARMING TREND WILL BEGIN ON SUNDAY AND CONTINUE INTO MONDAY
AS THE SURFACE HIGH SHIFTS EAST OF THE CWA...AND FLOW ACROSS THE
REGION BECOMES SOUTHERLY. STILL...AN OVERALL SEASONABLE DAY WILL BE
ON TAP SUNDAY AS HIGHS RANGE FROM THE MID 40S TO MID 50S UNDER SUNNY
SKIES. CLOUDS WILL INCREASE SUNDAY NIGHT INTO MONDAY MORNING AS
LOWS RANGE FROM THE MID 30S TO MID 40S. HIGHS MONDAY UNDER MOSTLY
CLOUDY SKIES WILL RANGE FROM THE MID 50S TO MIDDLE 60S...AND FALL
INTO THE UPPER 30S TO AROUND 50 MONDAY NIGHT.
THE BEFORE MENTIONED INCREASE IN CLOUD COVER SUNDAY NIGHT INTO
MONDAY MORNING IS IN RESPONSE TO AN UPPER LEVEL TROUGH SWINGING
ACROSS THE NATION`S MID-SECTION...AND MOISTURE INCREASING AHEAD OF
IT. THIS TROUGH WILL SEND ANOTHER COLD FRONT SLOWLY INTO AND
THROUGH THE FORECAST AREA MONDAY EVENING INTO TUESDAY. THIS WILL
ALSO BRING AN INCREASE IN RAIN CHANCES FROM MONDAY AFTERNOON THROUGH
AT LEAST TUESDAY. RAIN COULD LINGER ACROSS THE REGION INTO THE FIRST
PART OF WEDNESDAY...PRIMARILY ACROSS MY SOUTH...BUT ANOTHER
SHORTWAVE SWINGING OUT OF THE SOUTHERN PLAINS CURRENTLY LOOKS TO
CLEAR THE CWA OF RAIN BY WEDNESDAY EVENING. A RETURN TO CLEAR AND
QUIET WEATHER PREVAILS FOR THURSDAY. /19/
AVIATION...IFR TO SOME LIFR CEILINGS ARE PREVAILING EARLY THIS
MORNING AS LIGHT TO OCCASIONALLY MODERATE RAIN IS MOVING THROUGH THE
REGION. SOME LOCATIONS MAY SEE A MIX WITH LIGHT SNOW THROUGH
DAYBREAK ESPECIALLY WEST OF THE MS RIVER. RAIN IS STILL EXPECTED TO
TRANSITION TO LIGHT SNOW THROUGH THE MORNING HOURS AND END FROM WEST
TO EAST THROUGH TEH AFTERNOON/EVENING. AS RAIN/SNOW DEPARTS...
CEILINGS SHOULD GRADUALLY LIFT BACK TO MVFR. VERY GUSTY NORTH/NORTHWEST
WINDS ARE EXPECTED TO CONTINUE TODAY WITH SPEEDS AROUND 15KTS GUSTING
TO 20-25KTS ACROSS MOST OF THE AREA. HOWEVER...THE DELTA WILL HAVE
SPEEDS AROUND 25KTS GUSTING TO 30KTS. /28/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 36 28 41 25 / 66 5 0 0
MERIDIAN 40 29 41 24 / 61 5 1 0
VICKSBURG 36 29 40 26 / 60 5 0 0
HATTIESBURG 43 30 47 25 / 24 5 0 0
NATCHEZ 40 29 43 25 / 40 5 0 0
GREENVILLE 34 27 35 25 / 72 5 0 0
GREENWOOD 34 26 36 22 / 86 5 2 0
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR MSZ018-
019-025>042-047.
WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR MSZ018-019-034-035-
040-041-047.
LA...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR
LAZ007>009-015-016.
WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR LAZ007>009-015-016-
023-025.
AR...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR ARZ074-
075.
WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR ARZ074-075.
&&
$$
JAN/JAN/
AREA FORECAST DISCUSSION
NWS RALEIGH NC
132 PM EST FRI JAN 22 2016
.SYNOPSIS...
A POWERFUL STORM SYSTEM WILL TRACK NORTHEASTWARD OVER
THE CAROLINAS TODAY THROUGH TONIGHT... THEN PUSH SLOWLY OFF THE
MIDATLANTIC COAST SATURDAY THROUGH SATURDAY NIGHT. HIGH PRESSURE
WILL BUILD OVER THE AREA SUNDAY... THEN MOVE EAST AND OFFSHORE
MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1035 AM THURSDAY...
...WINTER STORM WARNING CONTINUES ACROSS CENTRAL NC...
...GUIDANCE/TRENDS INDICATE WARMER AIR IN THE MID LEVELS WILL LESSEN
SNOW ACCUMULATIONS BUT WILL STILL YIELD SIGNIFICANT FREEZING RAIN
ACCUMULATIONS...
...CONVECTION UPSTREAM ACROSS THE GULF POSSIBLY DISRUPTING MOISTURE
TRANSPORT WHICH COULD LOWER LIQUID EQUIVALENT AMOUNTS...
BASED ON LATEST OBSERVATIONS AND TRENDS...ITS BECOMING PRETTY
APPARENT THAT MOST OF CENTRAL NC WILL BE CONTENDING WITH A MORE ICY
SCENARIO OF FREEZING RAIN/SLEET MIX THIS MORNING AND INTO THE
AFTERNOON AS THE LAYER OF WARM AIR ALOFT WAS A BIT UNDERESTIMATED BY
THE MODEL GUIDANCE. THE GREATEST POTENTIAL FOR ICING IS EXPECTED
WEST OF HIGHWAY 1 WHERE HOURLY LIQUID QPF AMOUNTS AOA 0.05 IN/HR FOR
A MULTI-HOUR DURATION WOULD EASILY YIELD 0.25-0.50" WITHIN THIS
CORRIDOR. WILL LIKELY NEED TO RAISE ICE AMOUNTS INTO THE 0.10-0.25"
OVER THE EASTERN PIEDMONT...SANDHILLS AND CENTRAL/NORTHERN PORTIONS
OF THE COASTAL PLAIN AS WELL...WITH RAP/HRRR SFC WET BULBS
INDICATING A MUCH SLOWER NORTH-NORTHWESTWARD RETREAT THIS AFTERNOON.
THE ONE AREA THAT WE COULD STILL SEE SOME CONSIDERABLE SNOW AMOUNTS
WILL BE NORTH OF THE I-85 CORRIDOR...WHICH INCLUDES THE TRIAD AND
ROXBORO(PERSON COUNTY)...WHERE A NEAR-FREEZING ISOTHERMAL LAYER ATOP
A 7-8 DEGREE C COLD NOSE WILL SUPPORT MOSTLY SNOW/SLEET MIX.
SNOWFALL AMOUNTS OF 3 TO 6 INCHES.
AS SUBSTANTIAL WARMING ALOFT OF 3-7 DEGREES CELSIUS CENTERED AROUND
H8 CONTINUES TO SPREAD NORTH...STILL EXPECT PRECIP TO EVENTUALLY
SWITCH OVER TO ALL RAIN EAST OF THE TRIANGLE(US 1 CORRIDOR)THIS
AFTERNOON AND EVENING AND POSSIBLY A FREEZING RAIN/RAIN MIX AROUND
THE TRIANGLE.
PREVIOUS DISCUSSION...
RECENT GUIDANCE AND SURFACE OBSERVATIONS SUGGEST THAT SOME DOWNWARD
ADJUSTMENT TO THE ACCUMULATION TOTALS ARE LIKELY NEEDED.
HIGHER RESOLUTION GUIDANCE INCLUDING THE HI RES WINDOW ARW AND NMM
AND THE HRRR NOTE THE BACK EDGE OF THE SIGNIFICANT PRECIPITATION
LIKELY TO PROGRESS THROUGH CENTRAL NC MUCH MORE QUICKLY AND AHEAD
OF THE DRY SLOT. IN ADDITION...SURFACE OBSERVATIONS NOTE A
SIGNIFICANT PRESSURE FALL NORTH AND NORTHEAST OF THE SURFACE LOW
IN ALABAMA. THE HRRR PICKS UP ON THIS AND HIGHLIGHTS A SFC
PRESSURE FIELD INDICATIVE OF A POSSIBLE GRAVITY WAVE WITH
PRECIPITATION DECREASING BEHIND THIS FEATURE. HAVE ACCORDINGLY
LOWERED SNOW AND SLEET ACCUMULATIONS AROUND 10 TO 20 PERCENT OR
AROUND AN INCH OR TWO IN MOST LOCATIONS. OF NOTE...THE 07Z HRRR
BRINGS THE BACK EDGE OF THE STEADY PRECIPITATION TO RDU AT 21Z.
LATER SHIFTS WILL NEED TO MONITOR OBSERVATIONAL TRENDS AND ADJUST
FORECAST AS NEEDED. EVEN WITH TOTAL AMOUNTS DOWN A BIT...HAZARDOUS
TRAVEL CONDITIONS ARE EXPECTED.
IN ADDITION...LATEST GUIDANCE INCLUDING GFS AND SREF BUFR
SOUNDINGS WARM THE MID LEVELS MORE THAN PREVIOUS RUNS. THIS MORE
PROMINENT WARM NOSE MAKES MORE NORTHWEST PROGRESS AND SHOULD
RESULT IN LESS SNOW BUT A LARGER FRACTION OF SLEET AND FREEZING
RAIN.
GUIDANCE SUGGESTS THAT THE SIGNIFICANT PRECIPITATION WITH HOURLY
LIQUID EQUIVALENT RATES OF 0.05 TO 0.10 WILL EXPAND NORTHEAST
ACROSS THE RAH CWA THIS MORNING. THE PRECIPITATION WILL LIKELY BE
A LITTLE LIGHTER ACROSS THE EASTERN SANDHILLS AND SOUTHERN COASTAL
PLAIN THROUGH AT LEAST MID MORNING WITH THE STEADIER PRECIPITATION
ARRIVING LATE THIS MORNING AND AFTERNOON. INITIAL REPORTS INCLUDE
A FAIR AMOUNT OF SLEET AT THE ONSET...WITH TIME EARLY THIS MORNING
PRECIPITATION WILL BECOME MOSTLY SNOW IN THE TRIAD AND A MIX OF
SLEET AND SNOW IN THE TRIANGLE. FURTHER SOUTH...THE PRECIPITATION
HAS STARTED AS RAIN IN THE SOUTHERN TIER BUT COOLING FROM
EVAPORATION SHOULD RESULT IN A PERIOD OF FREEZING RAIN AND SLEET.
AS THE LOW AND MID LEVEL SOUTHERLY FLOW INCREASES...EXPECTED THE
PTYPE TO CHANGE TO RAIN IN THE COASTAL PLAIN AROUND OR JUST AFTER
MIDDAY. SNOW AND SLEET IN THE TRIANGLE WILL CHANGE TO SLEET AND
FREEZING RAIN IN THE EARLY AFTERNOON WHILE MOSTLY SNOW HOLDS ON
IN THE TRIAD. BY MID AFTERNOON MOSTLY FREEZING RAIN WILL BE
FALLING IN THE TRIANGLE WITH THE SNOW IN THE TRIAD MIXING WITH
SLEET. THE STEADIEST PRECIPITATION WILL LIKELY BE SHUTTING DOWN
FROM WEST TO EAST LATE THIS AFTERNOON AND EARLY THIS EVENING.
RESIDUAL MOISTURE AND SOME FORCING FOR ASCENT WILL CONTINUE THIS
EVENING AND OVERNIGHT. DEEP LAYER SATURATION WILL NOT EXTEND TO
ICE GLACIATION REGION WHICH WILL SHUT DOWN SNOW AND SLEET
OVERNIGHT BUT RESULT IN PERIODS OF FREEZING RAIN AND FREEZING
DRIZZLE.
STORM TOTAL SNOW AND SLEET ACCUMULATIONS IN THE TRIAD WILL RANGE
FROM 4 TO 8 INCHES IN THE TRIAD...LOCALLY MORE NORTH OF I-40 WITH
A TENTH OF AN INCH OF FREEZING RAIN. TO THE SOUTH AND EAST OF THE
IMMEDIATE TRIAD REGION...3 TO 5 INCHES OF SNOW AND SLEET ARE
EXPECTED ALONG WITH ICE ACCUMULATIONS AROUND A QUARTER OF AN INCH.
ACROSS MUCH OF THE TRIANGLE AND EASTERN PIEDMONT...SNOW AND SLEET
ACCUMULATION OF 2 TO 4 INCHES ARE EXPECTED WITH LOCALLY HEAVIER
AMOUNTS NORTH OF RALEIGH NEAR THE VIRGINIA BORDER. SNOW AND SLEET
ACCUMULATION ACROSS THE SOUTHERN PIEDMONT SHOULD TOTAL AN INCH OR
LESS. ICE ACCRUAL SHOULD TOTAL A QUARTER TO A THIRD OF AN INCH.
ACROSS THE EASTERN SANDHILLS AND COASTAL PLAIN...SNOW ACCUMULATION
OF UP TO AN INCH...ALONG WITH A TENTH TO TWO-TENTHS OF AN INCH OF
FREEZING RAIN ARE EXPECTED.
HIGH TEMPERATURES TODAY WILL RANGE INT THE UPPER 20S IN THE TRIAD
AREA TO TO THE UPPER 30S SOUTHEAST. TEMPERATURES WILL FALL ONLY
A COUPLE OF DEGREES TONIGHT. NORTHEAST WINDS WILL INCREASE THIS
MORNING REACHING 10- 20 MPH SUSTAINED WITH GUSTS TO AROUND 30 MPH.
WINDS WILL BACK AROUND TO NORTH THEN NORTHWEST TONIGHT. -BLAES
&&
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
AS OF 325 AM FRIDAY...
SAT/SAT NIGHT: WRAPAROUND PRECIP PRIMARILY IN THE FORM OF SNOW WILL
BE THE PRIMARY CONCERN HERE... WITH CONTINUED BRISK AND GUSTY WINDS
FROM THE NNW AND NW. MODELS ARE IN GOOD AGREEMENT WITH THE SURFACE
LOW OCCLUDING AS IT MOVES SLOWLY FROM JUST OFF NORFOLK ENE TO OFF
THE SOUTHERN NEW ENGLAND COAST BY SUN MORNING. ADDITIONAL QPF WILL
BE LIMITED BY THE WEAKER FORCING FOR ASCENT COMPARED TO TODAY`S DEEP
LAYER LIFT... BY SOME DRYING CONTRIBUTION FROM DOWNSLOPE LOW LEVEL
FLOW... AND BY THE THE MARGINAL AMOUNTS OF MOISTURE ABOVE -10C WHICH
BRINGS INTO QUESTION HOW MUCH ICE THERE WILL BE IN THE CLOUDS. OUR
BEST ESTIMATE IS ANOTHER ONE-HALF TO ONE-AND-A-HALF INCHES OF SNOW
MAINLY OVER THE NORTHERN PIEDMONT COUNTIES ON SAT... WITH THE
HIGHEST AMOUNTS AT THE VA BORDER. BASED ON THE AFOREMENTIONED
DOWNSLOPE FLOW AND THE LATEST FORECAST SOUNDINGS... EXPECT A BIT
QUICKER END TO PRECIP CHANCES FROM SW TO NE SAT EVENING AS COMPARED
TO THE PREVIOUS FORECAST... SUCH THAT LITTLE TO NO ADDITIONAL
ACCUMULATION IS ANTICIPATED AFTER 00Z SUNDAY. SKIES WILL GRADUALLY
CLEAR WEST TO EAST LATE. ANOMALOUSLY LOW THICKNESSES AND ABUNDANT
CLOUD COVER WILL HOLD SAT TEMPS DOWN TO LOWER-MID 30S. LOWS FROM THE
LOWER 20S WEST TO UPPER 20S EAST. DOWNWARD MOMENTUM TRANSPORT SHOULD
PUSH GUSTS PERIODICALLY UP TO 25-30 MPH... AND PERHAPS HIGHER IN THE
FAR NE CWA SAT AFTERNOON.
SUN THROUGH MON NIGHT: THE CLEARING TREND CONTINUES EARLY SUNDAY AS
THE STORM PULLS FURTHER OUT TO SEA AND BOTH SURFACE HIGH PRESSURE
AND MID LEVEL SHORTWAVE RIDGING BUILDING FROM THE WEST. EXPECT
MOSTLY SUNNY/MOSTLY CLEAR SKIES SUN/SUN NIGHT WITH CHILLY BUT SLOWLY
MODERATING TEMPS... PEAKING IN THE UPPER 30S (N) TO MID 40S (S) SUN
WITH LOWS IN THE UPPER TEENS TO MID 20S SUN NIGHT. THE RIDGE AXIS
FROM THE SURFACE UP THROUGH THE MID LEVELS SHIFTS OFF THE COAST MON
AND THE ENSUING ONSET OF WARM AIR ADVECTION (AHEAD OF THE NEXT STORM
SYSTEM) WILL LEAD TO INCREASING HIGH CLOUDS FROM WEST TO EAST...
PARTICULARLY MON NIGHT. TEMPS SHOULD RECOVER BACK CLOSER TO
NORMAL... WITH HIGHS FROM THE MID 40S TO LOWER 50S... AND MON NIGHT
LOWS IN THE MID-UPPER 30S. -GIH
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 205 AM FRIDAY...
SPLIT FLOW ALOFT WILL BECOME INCREASINGLY SO EARLY TO MID NEXT WEEK
OVER THE EASTERN NORTH PACIFIC AND WESTERN NOAM...AS NORTHERN STREAM
RIDGING THERE BECOMES INCREASINGLY AMPLIFIED. DOWNSTREAM...A
CORRESPONDING INCREASINGLY AMPLIFIED POSITIVELY-TILTED TROUGH ALOFT
WILL PROGRESS EAST...WITH SOME DEGREE OF PHASING POSSIBLE BETWEEN
THE STREAMS AS THE TROUGH APPROACHES THE EAST COAST. AN ASSOCIATED
SURFACE FRONTAL ZONE WILL ACCOMPANY THE APPROACHING TROUGH...WITH A
MODEL CONSENSUS TIMING OF THE PASSAGE OF THE FRONT -AND ASSOCIATED
BAND OF SHOWERS- LATE TUE OR TUE NIGHT.
THERE CONTINUES TO BE A SIGNAL IN NWP GUIDANCE OF CYCLOGENESIS ALONG
THE TAIL END OF THAT FRONT...FROM THE EASTERN GULF OF MEXICO TO
OFFSHORE THE SOUTHEAST US COAST...THOUGH MODEL SPREAD IN THE
EXISTENCE AND/OR TRACK OF THE LOW...AND ASSOCIATED FORECAST
UNCERTAINTY...IS VERY LARGE. WILL MAINTAIN RELATIVE CONTINUITY WITH
THE PREVIOUS RAH OFFICIAL FORECAST...WITH A CONTINUED SLIGHT-LOW
CHANCE OF PRECIPITATION TUE NIGHT-THU...WITH POST-FRONTAL DEEP-LAYER
COOLING SUPPORTIVE OF A MIX OR CHANGE TO SNOW -CONDITIONAL UPON
PRECIPITATION INDEED OCCURRING -OVER CLIMATOLOGICALLY-FAVORED AREAS
OF THE PIEDMONT...WHEN SURFACE TEMPERATURES ARE COLDEST DURING THE
MORNING AND NIGHTTIME HOURS WED.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 130 PM FRIDAY...
24 HOUR TAF PERIOD: AS THE WINTER STORM CONTINUES TO PASS THROUGH
THE AREA EXPECT RAPIDLY CHANGING CONDITIONS AT ALL TAF SITES THIS
AFTERNOON. PRECIPITATION TYPES WILL VARY BUT WILL GRADUALLY
TRANSITION FROM MOSTLY SLEET TO MOSTLY FREEZING RAIN AND POTENTIALLY
RAIN THIS AFTERNOON BEFORE MORE FREEZING RAIN OVERNIGHT AND FINALLY
BACK TO SNOW AS THE BACK OF THE STORM MOVES THROUGH ON SATURDAY.
WIND GUSTS WILL BE CONSISTENTLY INTO THE LOW 20 KT RANGE AND COULD
GO AS HIGH AS 35 KTS ON OCCASION. GUSTS MAY NOT DROP OFF ALL THAT
MUCH OVERNIGHT AND THEN CONTINUE AGAIN SATURDAY BUT NOT QUITE AS
STRONG.
VISIBILITIES WILL JUMP AROUND AS WELL BUT IFR/MVFR WILL BE THE MOST
COMMON VISIBILITY RANGES. CEILINGS WILL ALSO MOST COMMONLY BE IN THE
IFR RANGE.
PRECIPITATION WILL END FROM WEST TO EAST LATER ON SATURDAY...MOST
LIKELY AFTER THE END OF THE TAF PERIOD.
LONG TERM: CONDITIONS WILL CONTINUE TO BE SUB-VFR THROUGH SATURDAY
EVENING BEFORE RETURNING TO VFR SUNDAY AND MONDAY. THE NEXT SYSTEM
TO AFFECT THE AREA WILL ARRIVE ON TUESDAY NIGHT.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR NCZ028-
043-078-089.
WINTER STORM WARNING UNTIL 6 PM EST SATURDAY FOR NCZ007>011-
021>026-038>041-073>077-083-084.
WINTER STORM WARNING UNTIL 6 PM EST THIS EVENING FOR NCZ027-
042-085-086-088.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...CBL/BLAES
SHORT TERM...HARTFIELD
LONG TERM...MWS
AVIATION...ELLIS
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
424 PM EST FRI JAN 22 2016
.SYNOPSIS...
LOW PRESSURE MOVING INTO THE SOUTHERN APPALACHIANS WILL WEAKEN
TONIGHT AS ANOTHER LOW DEVELOPS ALONG THE MID ATLANTIC COAST.
HIGH PRESSURE WILL BUILD ACROSS THE REGION DURING THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
SNOW CONTINUES TO OCCUR ACROSS THE SOUTHERN COUNTIES THIS
AFTERNOON. EARLIER DEVELOPMENT FURTHER NORTH DIMINISHED. BIG
QUESTION IS WHETHER THERE WILL BE ANY ADDITIONAL NORTHWARD
PROGRESS/DEVELOPMENT. RECENT HRRR AND RAP RUNS CONTINUE TO SUGGEST
THAT THIS IS POSSIBLE. ALSO AS PRECIPITATION SHIELD PIVOTS WITH
TRANSFER OF ENERGY TO THE COAST IT APPEARS THAT SOME SNOW COULD
DEVELOP INTO THE COLUMBUS AREA THIS EVENING.
AT THIS POINT HAVE OPTED TO BE QUITE CONSERVATIVE WITH FORECAST
GOING WITH ONLY VERY MINOR CHANGES TO STORM TOTAL ACCUMULATIONS.
BUT CLEARLY IF CURRENT TRENDS CONTINUE THEN LOWER AMOUNTS WILL BE
NEEDED EXCEPT FOR PARTS OF NORTHEAST KENTUCKY AND SOUTH CENTRAL
OHIO WHERE FRONTOGENESIS MAY STILL LEAD TO A PERIOD OF HEAVY SNOW
LATE THIS AFTERNOON INTO THE EARLY EVENING.
SNOW WILL DIMINISH/MOVE OFF TO THE EAST LATE TONIGHT. FORECAST
LOWS STAYED CLOSE TO MOS CONSENSUS.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
COULD BE SOME LIGHT SNOW LINGERING IN SOUTHEAST COUNTIES AT THE
BEGINNING OF THE PERIOD. CLOUDS WILL DECREASE FROM NORTHWEST TO
SOUTHEAST THROUGH THE DAY AS HIGH PRESSURE BEGINS TO BUILD IN.
CENTER OF THE HIGH WILL PASS SOUTH OF THE AREA WITH MAINLY CLEAR
SKIES AND RELATIVELY GOOD RADIATIONAL COOLING CONDITIONS
ESPECIALLY WHERE FRESH SNOW PACK WILL BE. SOUTHERLY FLOW WILL
BECOME ESTABLISHED SUNDAY INTO SUNDAY NIGHT WITH HIGH CLOUDS
SPREADING ACROSS THE REGION.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
HIGH PRESSURE WILL BE SITUATED EAST OF THE FA AT THE START OF THE
LONG TERM PERIOD. SOUTHERLY FLOW WILL ALLOW TEMPERATURES TO WARM
INTO THE MIDDLE 30S TO LOW 40S ON MONDAY. CLOUD COVER WILL INCREASE
THROUGH THE DAY AS A SYSTEM APPROACHES THE AREA.
PRECIPITATION IS EXPECTED TO HOLD OFF UNTIL LATE IN THE DAY ON
MONDAY AND INTO MONDAY NIGHT. PRECIPITATION WILL GENERALLY BE IN THE
FORM OF RAIN AT THE START OF THE PRECIPITATION. AS THE COLD FRONT
MOVES THROUGH AND COLDER AIR FILTERS INTO THE REGION RAIN WILL
BEGIN TO CHANGEOVER TO SNOW SHOWERS LATE MONDAY NIGHT INTO
TUESDAY.
TEMPERATURES WILL FALL THROUGH THE DAY ON TUESDAY AS COLDER AIR
CONTINUES TO MOVE INTO THE REGION. WINDS WILL PICK UP MONDAY NIGHT
AND ESPECIALLY ON TUESDAY WITH THE FRONTAL BOUNDARY AND AFTER THE
PASSAGE OF THE FRONTAL BOUNDARY. WIND GUSTS UP TO 35 MPH WILL BE
POSSIBLE.
A COUPLE OF DISTURBANCES WILL BRING THE POTENTIAL FOR SOME SNOW
SHOWERS ON WEDNESDAY AND THEN AGAIN THURSDAY NIGHT. LIMITED
PRECIPITATION CHANCES TO THE SLIGHT CHANCE OR CHANCE CATEGORY AT
THIS TIME DUE TO MODEL RUN TO RUN INCONSISTENCIES.
&&
.AVIATION /21Z FRIDAY THROUGH WEDNESDAY/...
SNOW HAS BEEN SLOWLY SPREADING NORTH THROUGH LATE MORNING AND
EARLY THIS AFTERNOON. IN THE LAST HOUR OR SO...A NICE DEFORMATION
AXIS HAS SET UP...RUNNING FROM NEAR KCVG THROUGH KILN TO SOUTH OF
KLCK. THIS COULD LEAD TO SOME IFR CONDITIONS OVER THE NEXT FEW
HOURS ALONG AND JUST SOUTHEAST OF THE I-71 CORRIDOR.
MEANWHILE...SNOW TO OUR SOUTH SHOULD CONTINUE TO FILL IN AS IT
PUSHES SLOWLY NORTH THROUGH THE REST OF THE AFTERNOON..PRIMARILY
AFFECTING KCVG/KLUK WITH MVFR TO IFR AND LOWER CONDITIONS AS WE
HEAD THROUGH LATE AFTERNOON INTO EARLY EVENING. 12Z MODELS CONTINUE
TO SHOW A FAIRLY TIGHT GRADIENT TO THE PCPN CUTOFF...GENERALLY
RUNNING ALONG THE I-71 CORRIDOR. THIS WILL PUT KILN/KCMH/KLCK MORE
ON THE EDGE OF THE MORE SIGNIFICANT SNOWFALL SO WOULD EXPECT THEM
TO SEE PERIODS OF IFR CONDITIONS.
THE SNOW WILL BEGIN TO TAPER OFF FROM THE NORTHWEST LATER
TONIGHT...LEADING TO IMPROVING VSBYS. HOWEVER...ENOUGH LOW LEVEL
MOISTURE WILL LINGER TO KEEP CIGS MVFR THROUGH THE REMAINDER OF
THE TAF PERIOD. AS THE PRESSURE GRADIENT CONTINUES TO
TIGHTEN...NORTHEAST WINDS OF 15 TO 20 KNOTS WITH GUSTS OF 25 TO
30 KNOTS CAN ALSO BE EXPECTED THIS AFTERNOON INTO TONIGHT.
OUTLOOK...MVFR CEILINGS MAY CONTINUE INTO SATURDAY. MVFR/IFR
CONDITIONS ARE POSSIBLE AGAIN MONDAY NIGHT INTO WEDNESDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...WINTER WEATHER ADVISORY UNTIL 7 AM EST SATURDAY FOR OHZ063>065-
071-072-077.
WINTER STORM WARNING UNTIL 7 AM EST SATURDAY FOR OHZ073-074-
078>080-082.
WINTER STORM WARNING UNTIL NOON EST SATURDAY FOR OHZ081-088.
KY...WINTER STORM WARNING UNTIL 7 AM EST SATURDAY FOR KYZ089>097.
WINTER STORM WARNING UNTIL NOON EST SATURDAY FOR KYZ098>100.
IN...WINTER WEATHER ADVISORY UNTIL 7 AM EST SATURDAY FOR INZ073>075-
080.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...NOVAK
AVIATION...JGL
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
101 PM EST FRI JAN 22 2016
.SYNOPSIS...
LOW PRESSURE WILL MOVE FROM THE LOWER GULF COAST INTO THE
TENNESSEE VALLEY ON FRIDAY...THEN WEAKEN IN THE APPALACHIANS
FRIDAY NIGHT AS ANOTHER LOW DEVELOPS ALONG THE MID ATLANTIC COAST.
HIGH PRESSURE WILL GRADUALLY BUILD IN DURING THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
BETTER RETURNS ON RADAR ARE INCHING VERY SLOWLY NORTHWARD. THE
BEST RETURNS ARE STILL SOUTH OF OUR FA...BUT WE MAY BE STARTING TO
SEE SOME SNOW STARTING TO REACH THE GROUND ACROSS OUR FAR SOUTHERN
AREAS. THE LAST FEW RUNS OF THE RAP ARE STILL A LITTLE FARTHER
NORTH WITH THE PCPN PUSH BUT THIS LINES UP FAIRLY CLOSE WITH OUR
CURRENT FORECAST. TIMING AND AMOUNTS STILL SEEM REASONABLE SO NO
MAJORS CHANGES ARE PLANNED TO THE FORECAST AT THIS POINT.
PREVIOUS DISCUSSION...
UPR LVL CLOSED LOW OVER THE LOWER GULF COAST STATES THIS MORNING
WILL PIVOT EAST/NORTHEAST TOWARD THE TENNESSEE RIVER VALLEY BY
THIS EVENING. ITS ASSOCIATED SFC LOW PRESSURE WILL DO THE SAME
WITH AN INVERTED TROUGH POKING NORTHEAST INTO OHIO VALLEY.
THIS WEATHER SYSTEM WILL PIVOT AN EAST/WEST FRONTOGENETIC AREA
NORTHWARD TOWARD THE OHIO RIVER VALLEY. THE RESULTING SIGNIFICANT
VERTICAL MOTION IS STILL EXPECTED TO BE THE HIGHEST ALONG AND
SOUTH OF THE OHIO RIVER...WITH QUICKLY DIMINISHING FORCING AS ONE
HEADS FARTHER NORTH/NORTHWEST. AS IS TYPICAL WITH
FRONTOGENESIS/DEFORMATION...THERE WILL BE A SHARP CUT OFF TO THE
PCPN...AND THAT SO HAPPENS TO BE OVER THE FORECAST AREA. IN TERMS
OF PCPN TYPE...IT IS EXPECTED TO BE ALL SNOW AS SOUNDINGS/THERMAL
FIELDS INDICATE IT WILL REMAIN SUFFICIENTLY COLD. THE BIG QUESTION
WILL BE WHERE DOES THE PCPN REACH ITS FARTHEST NORTHWARD EXTEND
BEFORE IT BEGINS TO PIVOT EAST AS A COASTAL LOW TAKES OVER ALONG
THE MID ATLANTIC REGION TONIGHT. THE PREVIOUS FORECAST HAS HANDLED
THIS QUITE WELL FOR THE MOST PART. THE BIGGEST CHANGE WITH THE 00Z
RUNS COMPARED TO THE PREVIOUS FORECAST IS THAT THE MODELS...FOR
THE MOST PART...HAVE EVER SO SLIGHTLY SHIFTED THE
DEFORMATION/SHARP CUT OFF A LITTLE FARTHER NORTHWEST. AS
SUCH...STORM TOTAL QPF AND SUBSEQUENT STORM TOTAL SNOW HAD TO BE
ADJUSTED A LITTLE MORE NORTHWEST. USING A SNOW TO LIQUID RATIO
RANGING FROM 13:1 TO 15:1...THIS HAS PROMPTED TO ADD A FEW
COUNTIES TO THE PREVIOUS WINTER WEATHER ADVISORY
(RIPLEY...DEARBORN...AND WARREN). IN A NUTSHELL...SIGNIFICANT SNOW
IS EXPECTED OVER OUR SOUTHERN/SOUTHEASTERN FORECAST AREA WHERE 8
TO 14 INCHES OF SNOW COULD ACCUMULATE BY THE TIME IT TAPERS OFF BY
SATURDAY MORNING. THE HEAVIEST SNOW IN THESE AREAS IS EXPECTED
THIS AFTERNOON INTO THIS EVENING WHERE VERTICAL MOTION WILL BE
MAXIMIZE AS IT EXTENDS INTO THE FAVORABLE DENDRITIC GROWTH
ZONE...RESULTING IN PERIODS OF HEAVY SNOW. AS ONE HEADS FARTHER
NORTH/NORTHWEST...ACCUMULATIONS WILL SHOW A DOWNWARD TREND WITH
THE BUFFER ZONE (THE WINTER WEATHER ADVISORY) POSSIBLY SEEING 1 TO
3 INCHES. AGAIN...PREVIOUS WINTER STORM WARNINGS ARE STILL IN
EFFECT AND NO ADDITIONAL COUNTIES WERE ADDED TO THE WARNINGS.
SNOW WILL DECREASE IN INTENSITY TOWARD MIDNIGHT TONIGHT...WITH A
GRADUAL SHIFT TO THE WIDESPREAD SNOW FROM WEST TO EAST TOWARD
SATURDAY MORNING.
IN ADDITION TO THE SNOW THROUGH THE PERIOD....WINDS WILL INCREASE
FROM THE NORTHEAST IN THE 10 TO 20 MPH RANGE WITH GUSTS UP TO 30
MPH POSSIBLE.
TEMPERATURES TODAY WILL NOT WARM UP ALL THAT MUCH DUE TO OVERCAST
CONDITIONS...NORTHEAST WINDS...AND OVERSPREADING PCPN. HIGHS WILL
BE IN THE MID AND UPPER 20S. LOWS TONIGHT WILL RANGE FROM THE
LOWER TO MID 20S.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
MAJOR COASTAL STORM OFF THE MID ATLANTIC COAST WILL PUSH OUT TO
SEA ON SATURDAY. AS THIS OCCURS...ANY LINGERING SNOW WILL TAPER
OFF AND END BY AFTERNOON ACROSS THE EASTERN/SOUTHEASTERN ZONES. IT
SHOULD REMAIN FAIRLY CLOUDY AS LOW LEVEL MOISTURE LINGERS ACROSS
THE REGION. HIGHS WILL GENERALLY BE IN THE UPPER 20S.
FOR SATURDAY NIGHT...SURFACE HIGH PRESSURE IS FORECAST TO BUILD
INTO THE OHIO VALLEY. AT THE SAME TIME...SKIES ARE EXPECTED TO
BECOME MOSTLY CLEAR. IN LOCATIONS THAT SEE A DEEP SNOW PACK...THE
STAGE WILL BE SET FOR TEMPERATURES TO DROP MORE THAN WHAT SOME OF
THE CURRENT MODELS (ESPECIALLY MOS GUIDANCE) OR FORECASTING. HAVE
CONTINUED WITH THE PREVIOUS FORECAST WHICH IS TO ALLOW LOWS TO
DROP INTO THE SINGLE DIGITS WHERE SNOW WILL BE THE DEEPEST IN OUR
SOUTH/SOUTHEAST WITH MID TEENS AS ONE MOVES TOWARDS WEST CENTRAL
OHIO. IT IS CERTAINLY NOT OUT OF THE QUESTION FOR A FEW LOCATIONS
TO DIP SLIGHTLY BELOW ZERO...BUT WE WILL TAKE A CLOSER LOOK AT
THIS POSSIBILITY ONCE THE WINTER STORM IS OVER AND AMOUNTS ARE
VERIFIED.
FOR SUNDAY...HIGH PRESSURE WILL MOVE OFF TO THE EAST. RETURN FLOW
AND WAA IS EXPECTED. HOWEVER...MID AND HIGH LEVEL CLOUDS SPILLING
IN FROM THE NORTHWEST...COMBINED WITH ALBEDO FROM RECENT
SNOW...MAY KEEP TEMPERATURES COOLER IN THE EAST/SOUTHEAST THAN IF
THE GROUND WERE BARE. AS SUCH...HAVE HIGHS AROUND 30 IN THE
SOUTHEAST WITH LOWER TO POSSIBLE MID 30S POSSIBLE FOR THE
WEST/NORTHWEST.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
A SYSTEM WILL APPROACH THE AREA ON MONDAY. PRECIPITATION WILL
START OUT AS RAIN ACROSS MOST LOCATIONS. PRECIPITATION WILL START
TO CHANGE OVER TO SNOW MONDAY NIGHT AS THE COLD FRONT WORKS INTO
THE REGION AND COLDER AIR FILTERS IN. SNOW SHOWERS WILL TAPER OFF
DURING THE DAY ON TUESDAY.
A COUPLE OF ADDITIONAL DISTURBANCES WILL MOVE THROUGH ON WEDNESDAY
AND THURSDAY. PRECIPITATION WILL GENERALLY BE IN THE FORM OF SNOW
SHOWERS WITH THESE EVENTS.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
SNOW HAS BEEN SLOWLY SPREADING NORTH THROUGH LATE MORNING AND
EARLY THIS AFTERNOON. IN THE LAST HOUR OR SO...A NICE DEFORMATION
AXIS HAS SET UP...RUNNING FROM NEAR KCVG THROUGH KILN TO SOUTH OF
KLCK. THIS COULD LEAD TO SOME IFR CONDITIONS OVER THE NEXT FEW
HOURS ALONG AND JUST SOUTHEAST OF THE I-71 CORRIDOR.
MEANWHILE...SNOW TO OUR SOUTH SHOULD CONTINUE TO FILL IN AS IT
PUSHES SLOWLY NORTH THROUGH THE REST OF THE AFTERNOON..PRIMARILY
AFFECTING KCVG/KLUK WITH MVFR TO IFR AND LOWER CONDITIONS AS WE
HEAD THROUGH LATE AFTERNOON INTO EARLY EVENING. 12Z MODELS CONTINUE
TO SHOW A FAIRLY TIGHT GRADIENT TO THE PCPN CUTOFF...GENERALLY
RUNNING ALONG THE I-71 CORRIDOR. THIS WILL PUT KILN/KCMH/KLCK MORE
ON THE EDGE OF THE MORE SIGNIFICANT SNOWFALL SO WOULD EXPECT THEM
TO SEE PERIODS OF IFR CONDITIONS.
THE SNOW WILL BEGIN TO TAPER OFF FROM THE NORTHWEST LATER
TONIGHT...LEADING TO IMPROVING VSBYS. HOWEVER...ENOUGH LOW LEVEL
MOISTURE WILL LINGER TO KEEP CIGS MVFR THROUGH THE REMAINDER OF
THE TAF PERIOD. AS THE PRESSURE GRADIENT CONTINUES TO
TIGHTEN...NORTHEAST WINDS OF 15 TO 20 KNOTS WITH GUSTS OF 25 TO
30 KNOTS CAN ALSO BE EXPECTED THIS AFTERNOON INTO TONIGHT.
OUTLOOK...MVFR CEILINGS MAY CONTINUE INTO SATURDAY. MVFR/IFR
CONDITIONS ARE POSSIBLE AGAIN MONDAY NIGHT INTO WEDNESDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 7 AM EST
SATURDAY FOR OHZ063>065-071-072-077.
WINTER STORM WARNING UNTIL 7 AM EST SATURDAY FOR OHZ079-082.
WINTER STORM WARNING UNTIL 7 AM EST SATURDAY FOR OHZ073-074-
078-080.
WINTER STORM WARNING UNTIL NOON EST SATURDAY FOR OHZ081-088.
KY...WINTER STORM WARNING UNTIL 7 AM EST SATURDAY FOR KYZ094>097.
WINTER STORM WARNING UNTIL 7 AM EST SATURDAY FOR KYZ089>093.
WINTER STORM WARNING UNTIL NOON EST SATURDAY FOR KYZ098>100.
IN...WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 7 AM EST
SATURDAY FOR INZ073>075-080.
&&
$$
SYNOPSIS...HICKMAN/JGL
NEAR TERM...JGL
SHORT TERM...HICKMAN
LONG TERM...NOVAK
AVIATION...JGL
AREA FORECAST DISCUSSION
NWS Tulsa OK
311 PM CST FRI JAN 22 2016
.DISCUSSION...
Main forecast challenge for tonight will be the low cloud deck
lurking to the northwest of the Tulsa area and potential impact on
low temps. Clouds should eventually expand to cover much of
northeast OK and northwest AR as well as HRRR has been suggesting.
The clouds will likely keep overnight lows well above guidance
values across about northern third of CWA.
A warming trend will take place over the weekend as upper ridging
shifts east across the southern plains and winds pick up out of
the south...especially Sunday with deepening sfc low east of the
Rockies. Forecast low level wind fields suggest some gusts near
advisory levels will be possible across northeast OK Sunday
afternoon. This will also raise fire weather concerns though RH
should remain well above critical levels. Pacific cold front will
move through early Monday with a only small chance of showers
across mainly northwest AR ahead of the front as moisture return
will be limited.
Quiet weather will continue through the remainder of next week
with temperatures warming above normal by the end of the week.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 24 44 34 56 / 0 0 0 10
FSM 24 45 28 54 / 0 0 0 10
MLC 23 46 33 56 / 0 0 0 10
BVO 20 42 26 57 / 0 0 0 10
FYV 22 42 24 52 / 0 0 0 10
BYV 22 38 25 50 / 0 0 0 10
MKO 22 42 28 54 / 0 0 0 10
MIO 22 42 28 53 / 0 0 0 10
F10 22 42 33 56 / 0 0 0 10
HHW 25 45 29 56 / 0 0 0 10
&&
.TSA Watches/Warnings/Advisories...
OK...NONE.
AR...NONE.
&&
$$
SHORT TERM...18
LONG TERM....14
AREA FORECAST DISCUSSION
NWS NORMAN OK
1115 AM CST FRI JAN 22 2016
.AVIATION...
AREA OF LOWER MVFR CEILNGS ARE EXPECTED TO GRADUALLY CLEAR BY LATE
THIS AFTN. SFC WINDS ARE ALSO EXPECTED TO DIMINISH AND BECOME LIGHT
AROUND 00Z. SOUTH WINDS WILL RETURN BY LATE IN THE FORECAST WITH
SPEEDS INCREASING INTO THE 12KT TO 15KT RANGE BY THE END OF THE
FORECAST AT GAG/WWR/CSM/HBR.
30
&&
.PREV DISCUSSION... /ISSUED 538 AM CST FRI JAN 22 2016/
.DISCUSSION...
AVIATION DISCUSSION FOR THE 12Z TAFS IS BELOW.
&&
.AVIATION...
MVFR CEILINGS WILL AFFECT MOST SITES THROUGH AT LEAST 17Z BEFORE
DISSIPATING 17-03Z. THE EXACT TIMING OF DISSIPATION REMAINS
UNCERTAIN.
IFR CEILINGS MAY BE NEAR KGAG AND KWWR 12-17Z...BUT DID NOT
MENTION DUE TO LOW CONFIDENCE OF OCCURRENCE.
HAVE HIGH CONFIDENCE ALL SITES WILL BE VFR BY 03Z.
WINDS WILL SLOWLY DIMINISH THROUGH 23Z...THEN RAPIDLY WEAKEN
AFTER 23Z.
MBS
&&
.PREV DISCUSSION... /ISSUED 259 AM CST FRI JAN 22 2016/
DISCUSSION...
AFTER TODAY...WARMER WEATHER CAN BE EXPECTED. A DRY AND RATHER
QUIET WEATHER PATTERN IS EXPECTED FOR THE NEXT SEVEN DAYS.
TODAY WILL BE ANOTHER COLD DAY. CLOUD COVER REMAINS A BIT
TRICKY. FOLLOWED THE LATEST HRRR CEILING PRODUCT TO DEPICT CLOUD
COVER TODAY AND TONIGHT...WHICH GENERALLY DEPICTED CLOUD COVER
DECREASING ACROSS THE AREA...ESPECIALLY DURING THIS AFTERNOON AND
EVENING. APPEARS THE CLOUDS MAY HANG ON LONGEST NEAR ENID AND
MEDFORD IN PARTS OF NORTHERN OKLAHOMA. A STRAY SNOW FLURRY COULD
OCCUR NEAR PONCA CITY AND MEDFORD THIS MORNING...BUT DID NOT
MENTION DUE TO LOW CONFIDENCE OF OCCURRENCE. MODEL GUIDANCE HIGH
TEMPERATURES RANGING FROM THE MID 30S NEAR PONCA CITY TO NEAR 50
IN FAR WESTERN NORTH TEXAS NEAR KNOX CITY SEEMED REASONABLE AND
WERE FOLLOWED. WINDS WILL SLOWLY DIMINISH THIS AFTERNOON...THEN
RAPIDLY AFTER SUNSET.
TONIGHT...WENT WITH THE COLDER SIDE OF GUIDANCE LOWS TOWARDS THE
00Z METMOS NUMBERS THINKING CLEAR SKIES AND LIGHT WINDS WILL ALLOW
FOR GOOD RADIATIONAL COOLING.
SATURDAY WILL BE MOSTLY SUNNY AND WARMER WITH SURFACE WINDS SLOWLY
SHIFTING TO THE SOUTH.
SUNDAY WILL BE BREEZY TO WINDY AND WARMER YET. THINK MANY
LOCATIONS WILL GET ABOVE THE 60 DEGREE MARK. THE STRONGER WINDS
MAY ELEVATE FIRE WEATHER CONCERNS...THOUGH LOW LEVEL DEWPOINTS
WILL BE INCREASING THROUGHOUT THE DAY.
SUNDAY NIGHT INTO EARLY MONDAY...A COLD FRONT WILL MOVE THROUGH
THE AREA BRINGING A WIND SHIFT. MOISTURE APPEARS TO BE
LIMITED...SO KEPT A DRY FORECAST.
MONDAY THROUGH THURSDAY...DRY CONDITIONS WITH TEMPERATURES AT OR
ABOVE AVERAGE TEMPERATURES ARE FORECAST. A FEW WEAK COLD FRONTS
MAY MOVE THROUGH THE AREA AND BRING SURFACE WIND SHIFTS AS WELL
AS SMALL CHANGES IN TEMPERATURES EACH DAY.
MBS
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 38 21 48 32 / 0 0 0 0
HOBART OK 42 21 50 33 / 0 0 0 0
WICHITA FALLS TX 46 24 54 34 / 0 0 0 0
GAGE OK 43 16 54 30 / 0 0 0 0
PONCA CITY OK 34 13 47 30 / 0 0 0 0
DURANT OK 43 25 50 31 / 0 0 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
25/17/17
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1034 AM MST FRI JAN 22 2016
.SHORT TERM...TODAY THROUGH SATURDAY NIGHT
ISSUED AT 153 AM MST FRI JAN 22 2016
MASSIVE WESTERN NOAM RIDGE WILL SHIFT EAST INTO THE NORTHERN
PLAINS AHEAD OF THE NEXT EASTERN PAC UPPER TROUGH. WAA/HEIGHT
RISES ASSOCIATED WITH THIS RIDGE WILL SUPPORT WARMER TEMPS INTO
MUCH OF THE REGION...ESP OVER THE HIGH TERRAIN WHERE MIXING TO THE
SFC WILL BE ATTAINED. DRY WESTERLY FLOW WILL EVENTUALLY MIX OUT LL
STRATUS/PATCHY FOG OVER THE SD PLAINS W-E. HOWEVER...WAA PROCESS
ALOFT WILL SUPPORT A DIRTY RIDGE WITH BOUTS OF THICK CIRRUS AND
SOME MID CLOUD EXPECTED. THIS WILL HAMPER TEMP RISES ON THE SD
PLAINS...ESP OVER EASTERN AREAS. HAVE TAILORED HIGHS TO HAVE THE
WARMEST TEMPS OVER NE WY AND THE BLACK HILLS WHERE MIXING WILL BE
BEST. NORTHERN STREAM IMPULSE WILL FLATTEN THE NORTHERN EXTENT OF
THE MID LEVEL RIDGE AND SUPPORT A SFC TROUGH INTO THE REGION
TONIGHT. PRESSURE FALLS AHEAD OF THIS RIDGE WILL SUPPORT A PERIOD
OF DECENT DOWNSLOPE WESTERLY FLOW OVER THE BH/S WITH THE LEE SIDE
FOOTHILLS EXPECTED TO REMAIN MILD TONIGHT. SFC TROUGH WILL ADVECT
ACROSS THE AREA SAT...WITH WINDS SHIFTING NW AND INCREASING. THIS
WILL ALLOW A MUCH WARMER DAY FOR MOST OF THE AREA AS BETTER MIXING
IS ATTAINED. GIVEN MIXING AND TEMPS ALOFT...PORTIONS OF THE
EASTERN BLACK HILLS WILL SEE 50S WITH A FEW 60S POSSIBLE SAT.
MID/HIGH CLOUDS WILL AGAIN BE THICK ACROSS THE AREA AT TIMES
SAT...WHICH WILL AFFECT MAX T POTENTIALS. THE NEXT UPPER TROUGH
WILL SHIFT EAST INTO THE REGION SAT NIGHT...WITH RE-NEWED SFC
PRESSURE FALLS AND INCREASING CLOUDS. FAR WESTERN PORTIONS OF NE
WY COULD SEE SOME LIGHT SNOW EARLY SUN MORNING. HOWEVER BETTER
SNOW CHANCES WILL LIKELY HOLD OFF UNTIL LATER SUN MORNING GIVEN
DRY LL PROFILES.
.LONG TERM...SUNDAY THROUGH THURSDAY
ISSUED AT 153 AM MST FRI JAN 22 2016
00Z MODELS STILL ON TRACK WITH LONG WAVE TROUGH CROSSING THE
REGION SUNDAY INTO MONDAY...BRINGING A GOOD CHANCE FOR LIGHT SNOW
TO MUCH OF THE FORECAST AREA. BULK OF THE MODELS FOCUS THE BETTER
CHANCES FROM FAR NORTHEAST WY THROUGH NORTHWEST AND CENTRAL SD.
SOME LIGHT ACCUMULATIONS ARE EXPECTED ACROSS THESE AREAS...LIKELY
IN THE 1 TO 2 INCH RANGE. ACCOMPANYING COLD FRONT WILL BRING A
COOLDOWN TO NEAR AVERAGE TEMPERATURES FOR SUNDAY AND EARLY NEXT
WEEK.
NORTHWEST FLOW ALOFT WILL PREVAIL FOR MUCH OF NEXT WEEK...WITH
MOSTLY DRY CONDITIONS EXPECTED. HOWEVER...WEAK DISTURBANCES IN THE
FLOW WILL LIKELY BRING SOME CLOUDINESS FROM TIME TO TIME...AND
POSSIBLY LOW CHANCES FOR PCPN. AT THIS TIME...WEDNESDAY WOULD LOOK
TO BE THE BEST CHANCE FOR CLOUDS AND POSSIBLY A FEW SHOWERS. WILL
KEEP LOW POPS MOSTLY CONFINED TO THE BLACK HILLS AT THIS POINT. A
WARMING TREND IS LIKELY FOR WEDNESDAY AND LATER NEXT WEEK AS A RIDGE
IS FORECAST TO TRACK FROM THE WEST COAST THROUGH THE ROCKIES.
&&
.AVIATION...FOR THE 18Z TAFS THROUGH 18Z SATURDAY
ISSUED AT 1032 AM MST FRI JAN 22 2016
WIDESPREAD FOG AND LOW STRATUS WITH IFR/LIFR CIGS CURRENTLY
PRESENT ACROSS WESTERN SOUTH DAKOTA THIS MORNING...WITH HIGH
CIRRUS ACROSS NORTHEASTERN WYOMING. CURRENT NWP GUIDANCE SUGGESTS
THE FOG/STRATUS WILL STICK AROUND FOR MOST OF THE DAY AND EVENING
ACROSS THE SOUTH DAKOTA PLAINS. DIFFICULT FORECAST IN STORE FOR
THE KRAP TERMINAL...AS RAP AND HRRR SOUNDINGS INDICATE THE LOW FOG
AND STRATUS WILL BREAK UP THIS AFTERNOON OVER KRAP AND RESULT IN
CLEAR SKIES THROUGH THE EVENING. NAM SOUNDINGS KEEP THE
FOG/STRATUS AROUND FOR MOST OF THE NIGHT BEFORE WESTERLY
DOWNSLOPING WINDS PUSH THE FOG/STRATUS EAST OF THE TERMINAL AFTER
12Z SATURDAY. MOST NWP GUIDANCE HAVE WINDS SWITCHING TO THE WEST
JUST BEFORE MIDNIGHT...AND BELIEVE THAT MIGHT BE ENOUGH TO PUSH
THE FOG EAST OF THE KRAP TERMINAL. AS A RESULT...HAVE SKIES
CLEARING BY ABOUT 04Z.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...JC
LONG TERM...26
AVIATION...MCKEMY
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1224 PM CST FRI JAN 22 2016
.DISCUSSION...
FROZEN PRECIPITATION BEGAN LATE YESTERDAY EVENING IN THE FAR
NORTHWEST ZONES AFTER RAINFALL EARLIER YESTERDAY. CKV REPORTED
ABOUT A TENTH OF AN INCH OF ICE FROM FZRA SO FAR THIS
EVENING...BUT SHOULD SWITCH OVER TO SNOW WITHIN THE NEXT FEW
HOURS. CURRENT LOCATION OF THE SURFACE LOW IS IN WEST CENTRAL
ALABAMA...NEAR TUSCALOOSA. ITS PATH HAS BEEN NEARLY NNE FROM THE
GULF SO FAR DURING THE OVERNIGHT HOURS. CURRENT FORECAST DEPENDS
ON THE SURFACE LOW TRACKING A BIT FURTHER EAST...ALLOWING COLD AIR
TO FILTER IN BEHIND AND MAKE SNOW THE DOMINANT PRECIP TYPE FOR THE
AREA BY THIS AFTERNOON. IF THE SURFACE LOW TRACKS FURTHER
WEST...AREAS EAST OF NASHVILLE AND ESPECIALLY SOUTHEAST MAY SEE
MORE RAIN FOR A LONGER DURATION. THIS WILL CUT INTO THE CURRENT
FORECASTED SNOW AMOUNTS FOR THAT AREA.
LOOKING AT CURRENT OBS OVERNIGHT...TEMPERATURES HAVE TRENDED A BIT
COOLER THAN PREVIOUSLY FORECASTED...SO ADJUSTED TEMPS TODAY
ACCORDINGLY. DRY SLOT HAS JUST CREPT INTO THE SOUTHWEST PART OF
THE CWA AND SHOULD IMPACT MOST OF THE AREA BEFORE THE NEXT ROUND
OF PRECIP MOVES IN. FOR THE MOST PART...DID NOT CHANGE TRANSITION
OF PRECIP TYPES FROM THE PREVIOUS FORECAST. CURRENT THINKING IS TO
HAVE THE SWITCH OVER TO ALL SNOW FOR CKV BY 12Z...NASHVILLE
SHORTLY AFTER NOON...AND CSV AFTER 21Z. STILL DIFFICULT ON TIMING
FOR THE TRANSITION TO FROZEN PRECIP AND EVENTUALLY SNOW AS MODELS
STILL DISAGREE SLIGHTLY. HRRR IS CURRENTLY CLOSEST TO OBS WITH THE
COOLER TREND...SO TRIED TO STICK CLOSE TO THE HRRR WITH TEMPS AND
THE TRANSITION. BEFORE THE TRANSITION TO ALL SNOW...WE SHOULD SEE
A MIX OF FZRA...SLEET...AS WELL AS RAIN AND SNOW ACROSS THE AREA.
AS FOR SNOW AMOUNTS...HAVE THE NORTHERN AND CENTRAL PARTS OF THE
MID STATE WITH A BIT MORE SNOW THAN THE PREVIOUS FORECAST. CURRENT
HIGH SNOW AMOUNT FOR THE AREA IS AROUND 10 INCHES IN STEWART AND
MONTGOMERY COUNTIES. WITH THE COOLER TREND TO TEMPERATURES...IT IS
POSSIBLE FOR THIS AREA TO SEE SNOW THE LONGEST AND THUS RAISED
SNOW AMOUNTS. NASHVILLE AREA LOOKS TO BE BETWEEN 4 AND 5
INCHES...WHICH IS RIGHT NEAR THE MODEL CONSENSUS FOR SNOW AMOUNTS.
AREAS IN THE FAR SOUTH NEAR THE AL BORDER DIDNT SEE MUCH OF AN
INCREASE...BUT AMOUNTS IN WAYNE AND LAWRENCE COUNTIES ARE CLOSE TO
WARNING CRITERIA. MAY NEED TO UPGRADE THOSE COUNTIES FROM AN
ADVISORY IF TEMPS DROP A BIT SOONER AND OBVIOUSLY SNOW ONSET COMES
IN SOONER AS WELL.
LATER ON THIS EVENING HEAVIER SNOW SHOULD BE EAST OF I65 AND
MAINLY ON THE PLATEAU. BY THE OVERNIGHT HOURS INTO SATURDAY
MORNING...THE UPPER LOW SHOULD BE EAST OF THE REGION AND WRAP
AROUND SNOW SHOULD BE LIGHT ON THE PLATEAU. HIGH TEMPERATURES
SATURDAY SHOULD STAY BELOW FREEZING LARGELY DUE TO THE SNOW COVER
BUT ALSO WITH CAA BEHIND THE LOW. SATURDAY NIGHT INTO SUNDAY...LOW
TEMPERATURES ARE CURRENTLY IN THE SINGLE DIGITS AND TEENS ACROSS
THE AREA...BUT MAY NEED TO DROP FURTHER IF SNOWPACK IS AS DEEP AS
THE FORECAST SUGGESTS.
NEXT CHANCE FOR PRECIP LOOKS TO BE ON MONDAY AS AN UPPER SHORTWAVE
MOVES THROUGH THE MIDWEST AND CLIPS THE REGION. KEPT WEDNESDAY AND
THURSDAY DRY BEFORE MORE PRECIP MAY CLIP THE PLATEAU THURSDAY
NIGHT INTO FRIDAY. TEMPERATURES NEXT WEEK SHOULD MAINLY BE
SLIGHTLY BELOW NORMALS WHICH ARE IN THE MID TO UPPER 40S...WITH
EXCEPTION TO NEXT FRIDAY. CURRENT FORECAST HAS HIGHS ABOVE AVERAGE
ON MONDAY...BUT SNOW COVER MAY KEEP TEMPS RIGHT AROUND AVERAGE.
&&
.AVIATION...
18Z TAF DISCUSSION.
SNOW WILL CONTINUE ACROSS THE AREA THROUGH THE DAY THEN BEGIN TO
TAPER OFF FROM THE WEST THIS EVENING. POOR FLYING CONDITIONS WILL
CONTINUE INTO TONIGHT WITH SOME IMPROVEMENT AT CLARKSVILLE BEFORE
MIDNIGHT AND AFTER MIDNIGHT AT NASHVILLE. CROSSVILLE WILL LIKELY
STAY DOWN IN THE IFR RANGE NEXT 24 HOURS.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL NOON CST SATURDAY FOR CLAY-CUMBERLAND-
FENTRESS-GRUNDY-JACKSON-OVERTON-PICKETT-PUTNAM-VAN BUREN-WARREN-
WHITE.
WINTER WEATHER ADVISORY UNTIL 6 AM CST SATURDAY FOR BEDFORD-
COFFEE-GILES-LAWRENCE-MARSHALL-WAYNE.
WINTER STORM WARNING UNTIL 6 AM CST SATURDAY FOR CANNON-CHEATHAM-
DAVIDSON-DE KALB-DICKSON-HICKMAN-HOUSTON-HUMPHREYS-LEWIS-MACON-
MAURY-MONTGOMERY-PERRY-ROBERTSON-RUTHERFORD-SMITH-STEWART-SUMNER-
TROUSDALE-WILLIAMSON-WILSON.
&&
$$
SHORT TERM/AVIATION........01/BOYD
LONG TERM..................08
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1127 AM CST FRI JAN 22 2016
.UPDATE...AVIATION DISCUSSION.
&&
.PREV DISCUSSION... /ISSUED 937 AM CST FRI JAN 22 2016/
UPDATE...
AT 9AM...
SNOW HAS TAPERED OFF QUICKLY MAINLY WEST OF THE MISSISSIPPI RIVER
AND ACROSS MUCH OF NORTH MISSISSIPPI AT THIS HOUR. THE DEFORMATION
ZONE THAT WAS DEPICTED IN THE MODELS OVER THE LAST FEW DAYS HAS
FALLEN APART EARLIER THAN ANTICIPATED AND FORECASTED.
HOWEVER...IMPACTS CONTINUE TO BE FELT ACROSS THE MAJORITY OF THE
MID-SOUTH ON THE ROADS DUE TO ICY AND SLICK CONDITIONS.
TEMPERATURES WILL CONTINUE TO FALL A BIT DURING THE AFTERNOON
HOURS...KEEPING THE MAJORITY OF THE ACCUMULATED SNOW AROUND
THROUGH AT LEAST TOMORROW AFTERNOON.
THE LATEST HRRR MODEL GUIDANCE SUGGESTS THAT WE WILL SEE PERIODIC
SNOW SHOWERS THROUGH THIS AFTERNOON...BUT THE MAJORITY OF THE SNOW
HAS ALREADY FALLEN ACROSS THE AREA. THE HARDEST HIT AREAS WERE
OVER PORTIONS OF NORTHEAST ARKANSAS AND WEST TENNESSEE WHERE MANY
REPORTS OF 4 TO 6 INCHES WERE RECEIVED. ABOUT ANOTHER 1 TO 3
INCHES WILL BE POSSIBLE WITH THE HEAVIEST SNOW BANDS OVER
NORTHWEST TENNESSEE.
WILL CONTINUE TO MONITOR CONDITIONS FOR CANCELLATION OF CURRENT
WINTER STORM WARNINGS. HAVE UPDATED THE GRIDS TO REFLECT LOWER
SNOW ACCUMULATIONS OVER THE NEXT FEW HOURS. NEW ZONES AND GRIDS
ARE NOW AVAILABLE.
AC3
PREV DISCUSSION... /ISSUED 455 AM CST FRI JAN 22 2016/
DISCUSSION...
SIGNIFICANT WINTER STORM IMPACTING THE MID SOUTH TODAY...
SHORT TERM...TODAY THROUGH SUNDAY NIGHT...
A POWERFUL UPPER LEVEL LOW PRESSURE SYSTEM IS MOVING ACROSS THE
MID SOUTH THIS MORNING WITH SURFACE LOW PRESSURE DEEPENING AND
MOVING NORTHEAST ACROSS NORTHEAST MISSISSIPPI EARLY THIS MORNING.
THIS SURFACE LOW WILL CONTINUE TO SLOWLY LIFT NORTHEAST THROUGH
THE DAY.
HEAVY PRECIPITATION WITHIN CONVECTIVE BANDING FEATURES ASSOCIATED
WITH THE DEFORMATION ZONE IS OVER THE MID SOUTH THIS MORNING AND
WILL SLOWLY ROTATE ACROSS THE REGION FROM WEST TO EAST THROUGH THE
DAY. A WARM NOSE BASED AROUND 5 KFT THAT WAS NOTED FROM 07Z ACARS
SOUNDINGS FROM MEMPHIS INTERNATIONAL RESULTED IN FREEZING RAIN AT
THE ONSET OF PRECIPITATION ACROSS MUCH OF THE AREA WHERE SURFACE
TEMPERATURES WERE BELOW FREEZING. LATEST ACARS SOUNDING AT 10Z
INDICATES THAT THIS WARM LAYER HAS ERODED AND FREEZING RAIN HAS
CHANGED TO SNOW WEST OF THE MISSISSIPPI RIVER AND WILL CHANGEOVER
TO SNOW SHORTLY IN THE WEST TENNESSEE COUNTIES AND PORTIONS OF
NORTHWEST MISSISSIPPI. FURTHER SOUTHEAST...THE TRANSITION FROM
FREEZING RAIN TO SLEET/SNOW WILL TAKE LONGER...WITH LOCATIONS
SOUTHEAST OF TUPELO TAKING THE LONGEST WITH REDUCED ACCUMULATIONS.
HEAVY SNOWFALL WITH SOME SCATTERED THUNDERSNOW WILL BE POSSIBLE
ACROSS PORTIONS OF THE MID SOUTH BENEATH THE STRONGEST CONVECTIVE
BANDS. BENEATH THESE BANDS EARLIER ACROSS CENTRAL ARKANSAS...SNOW
RATES EXCEEDED 2 INCHES PER HOUR AND THIS WILL BE POSSIBLE ACROSS
PORTIONS OF THE WINTER STORM WARNING AREA. HEAVY SNOWFALL WILL
COMBINE WITH STRONG WINDS TO RESULT IN NEAR BLIZZARD CONDITIONS AT
TIMES WITH REDUCED VISIBILITIES AND BLOWING AND DRIFTING SNOW.
TRAVEL WILL LIKELY BECOME VERY DIFFICULT TO IMPOSSIBLE IN MANY
LOCATIONS ACROSS THE MID SOUTH LATER TODAY. TRAVEL IS NOT
RECOMMENDED.
SNOW WILL TAPER TO FLURRIES LATER THIS AFTERNOON AND EVENING FROM
WEST TO EAST WITH DIFFICULT TRAVEL CONTINUING INTO SATURDAY AS LOW
TEMPERATURES DROP INTO THE LOW TO MID 20S TONIGHT AND REMAIN BELOW
FREEZING ON SATURDAY IN MANY LOCATIONS DUE TO THE FRESH SNOWPACK.
INSOLATION FROM THE SUN WILL BEGIN THE SLOW MELTING PROCESS ON
SATURDAY WITH TRAVEL IMPROVING LATER IN THE DAY. HIGH PRESSURE
WILL KEEP DRY CONDITIONS IN PLACE INTO SUNDAY WITH SLOWLY
MODERATING TEMPERATURES AS SOUTHERLY FLOW RETURNS.
JLH
$$
LONG TERM...(MONDAY THROUGH THURSDAY)...
LONG TERM MODELS THIS MORNING INDICATE A BROAD LONGWAVE TROUGH AXIS
FROM THE GREAT LAKES REGION BACK THROUGH WEST TEXAS WILL SHIFT EAST
EARLY NEXT WEEK AS UPPER LEVEL RIDGING WEAKENS ACROSS THE LOWER
MISSISSIPPI AND TENNESSEE VALLEYS. THIS WILL ALLOW FOR ANOTHER COLD
FRONT TO MOVE THROUGH THE MID SOUTH MONDAY AND MONDAY NIGHT. RAIN
SHOWERS ARE EXPECTED WITH THIS FRONT ALONG WITH A POTENTIAL OF
PERHAPS SOME LIGHT SNOW LATE MONDAY NIGHT TOWARDS THE
MISSOURI/KENTUCKY BORDER IF MOISTURE LINGERS THROUGH THE NIGHT.
OTHERWISE...MAINLY PRECIPITATION FREE WEATHER IS EXPECTED THROUGH
THE REMAINDER OF NEXT WEEK WITH HIGH TEMPERATURES MAINLY IN THE 40S
AND LOWS IN THE UPPER 20S INTO THE 30S.
CJC
&&
.AVIATION...18Z TAF CYCLE
CONDITIONS CONTINUE TO IMPROVE ACROSS THE MIDSOUTH DURING THE
REMAINDER OF THE AFTERNOON. ANY PREVAILING VIS REDUCTION DUE TO
SNOW SHOULD BE MVFR....ALTHOUGH BRIEF PERIODS OF IFR VIS ARE STILL
POSSIBLE. SNOW HAS LIKELY ENDED AT JBR...AND IS NOT EXPECTED TO
CONTINUE MUCH LONGER THAN AN HOUR AR MEM. SNOW SHOULD END
ELSEWHERE NO LATER THAN 00Z. CIGS AT JBR HAVE IMPROVED TO
VFR...AND WILL LIKELY REMAIN VFR THROUGH SUNSET BEFORE MVFR CIGS
RETURN. MKL MAY SEE VFR CIGS RETURN TONIGHT. WINDS WILL REMAIN
NORTHERLY...GUSTING TO 25-30KT THIS AFTERNOON SUSTAINED 10-15KT.
10-15 KT NORTHERLY WINDS WILL CONTINUE TONIGHT...WEAKENING TO
AROUND 10KT TOMORROW. VFR CONDITIONS SHOULD RETURN TO ALL OF THE
MIDSOUTH BY MIDDAY TOMORROW.
30
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...WINTER STORM WARNING UNTIL NOON CST TODAY FOR CRITTENDEN-
MISSISSIPPI.
MO...WINTER STORM WARNING UNTIL NOON CST TODAY FOR PEMISCOT.
MS...WINTER STORM WARNING UNTIL 6 PM CST THIS EVENING FOR ALCORN-
BENTON MS-CALHOUN-COAHOMA-DESOTO-LAFAYETTE-MARSHALL-PANOLA-
PONTOTOC-PRENTISS-QUITMAN-TALLAHATCHIE-TATE-TIPPAH-
TISHOMINGO-TUNICA-UNION-YALOBUSHA.
WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR
CHICKASAW-ITAWAMBA-LEE MS-MONROE.
TN...WINTER STORM WARNING UNTIL 6 PM CST THIS EVENING FOR DYER-
FAYETTE-HARDEMAN-HARDIN-HAYWOOD-LAKE-LAUDERDALE-MCNAIRY-
SHELBY-TIPTON.
WINTER STORM WARNING UNTIL 9 PM CST THIS EVENING FOR BENTON TN-
CARROLL-CHESTER-CROCKETT-DECATUR-GIBSON-HENDERSON-HENRY-
MADISON-OBION-WEAKLEY.
&&
$$
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1245 PM EST FRI JAN 22 2016
.SYNOPSIS...
A DEVELOPING WINTER STORM WILL SLIDE EAST TOWARD THE SOUTHERN
APPALACHIANS TODAY BEFORE REFORMING OVER EASTERN NORTH CAROLINA BY
TONIGHT. THIS SYSTEM SHOULD PASS OFFSHORE SATURDAY FOLLOWED BY
WEAK HIGH PRESSURE SUNDAY INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1100 AM EST FRIDAY...
MAJOR WINTER STORM CONTINUES ACROSS THE AREA THIS MORNING INTO
TONIGHT. CHECK THE PNS AND LSR FOR SNOW TOTALS. SNOWFALL RATES
ON THE ORDER OF ONE TO TWO INCHES PER HOURS ARE OCCURRING
WITH THE HEAVY BANDS OF SNOW. WE ARE GETTING REPORTS OF SLEET AND
FREEZING RAIN MIXING IN. THREE MAJOR CONCERNS ARE THAT MIXED
WINTER PRECIPITATION WILL REDUCE SNOWFALL TOTALS ACROSS THE
SOUTH...THERE WILL BE A LITTLE MORE ICE ACCUMULATIONS IN THE
SOUTHEAST AND DRY AIR PUSHING IN TO THE SOUTHWEST. TREND QPF AND
SNOW TOTALS DOWN IN THE FAR WEST AND ACROSS SOUTHERN PORTIONS OF
FORECAST AREA. ADDED SOME ICE TO THE SOUTH. NEW SNOW AND ICE
TOTALS POSTED TO WEB. USED BLEND OF NAM AND CONTINUITY TO SHAPE
TEMPERATURE PROFILES...THEN CALCULATED WEATHER TYPES USING TOPDOWN
METHOD. ADJUSTED TEMPERATURES WITH LATEST TRENDS FOR THIS MORNING
INTO THIS AFTERNOON. MORE CHANGES LATER TODAY...
AS OF 245 AM EST FRIDAY...
NOT A LOT OF CHANGE TO THE GOING FORECAST WITH LOW PRESSURE NOW OVER
THE LOWER MISSISSIPPI VALLEY PROGGED TO RIDE UP INTO THE SOUTHERN
APPALACHIANS TODAY BEFORE GIVING WAY TO A DEEPENING COASTAL LOW OVER
EASTERN NC BY TONIGHT. PRECIP ALREADY CROSSING INTO SW VA WILL
QUICKLY SPREAD NORTH/EAST THROUGH THE MORNING AND BECOME HEAVIER
AS RESULTANT DEEP SE FLOW KICKS IN ALOFT AHEAD OF THE INITIAL
WAVE. MODELS REMAIN VERY IMPRESSIVE WITH SNOWFALL DURING THE DAY
WITH JUST ABOUT A PERFECT SETUP WITH STRONG UVV WITHIN THE
DENDRITIC ZONE AND CSI BANDING IF THEY ARE CORRECT. SOME GUIDANCE
ESPCLY THE GFS SHOWING SNOWFALL OF BETTER THAN 4-6 INCHES IN 6
HOURS THROUGH 00Z THIS EVENING SO APPEARS A LOT OF THE HEAVIER
SNOWFALL WILL OCCUR DURING THE DAY. THUS BOOSTED SNOWFALL AMOUNTS
ON THE FRONT END TODAY WITH A GOOD 10 INCHES TO A FOOT OR MORE
POSSIBLE JUST THROUGH SUNSET. HOWEVER THE LATEST CMC AND SOME
LOCAL SOLUTIONS A BIT FASTER WITH THE DRY SLOT THIS
AFTERNOON...ESPCLY THE LATEST HRRR WHICH REALLY CUTS BACK ON
AMOUNTS AFTER MIDDAY. THEREFORE SOMETHING TO WATCH ESPCLY GIVEN
SUCH STRONG LIFT THIS MORNING...AND POTENTIAL FOR THE UPPER JET
NOW BACK TO THE SW TO CORE OUT THE DEEPER MOISTURE RESULTING IN
LESS HEAVY SNOW LATER ON AS A PERIOD OF WEAK SUBSIDENCE ALOFT
SHIFTS NE. SLIGHTLY BETTER WARM NOSE ALSO SHOWING UP OVER THE FAR
SOUTH ESPCLY OFF THE NAM...MAINLY LATE IN THE WAKE OF THE BETTER
DYNAMIC COOLING SO INCLUDED A LITTLE MORE SLEET NW NC INTO
SOUTHSIDE VA. EVEN SOME FZRA POSSIBLE MAINLY FAR SE WHEN THE
TRANSITION FROM THE INLAND WAVE TO THE COASTAL TAKES SHAPE AS SEEN
WITH A SIMILAR SETUP IN THE PAST. EXPECT TEMPS TO FALL ONCE THE
PRECIP STARTS GIVEN DRY AIR WHICH MAY DELAY THE ONSET A BIT
FARTHER NORTH. OTRW LOOKING AT MAINLY 20S FOR HIGHS WITH SOME
READINGS SPILLING BACK INTO THE TEENS THIS MORNING.
AXIS OF DEEPER MOISTURE PROGGED TO LIFT OUT TO THE NORTH AND EAST
OVERNIGHT WITH MOST SOLUTIONS SHOWING A PRONOUNCED DRY SLOT OVER THE
SOUTH/WEST UNDER THE PASSAGE OF THE UPPER LOW. THIS SUPPORTS SOME
DOWNTURN IN SNOWFALL OUTSIDE OF THE FAR EASTERN/NORTHERN ZONES THIS
EVENING WITH MOSTLY BANDS OF LIGHT/MODERATE SNOW LIKELY PERSISTING
ELSEWHERE. HOWEVER QUITE A BIT LESS SOUTHERN HALF WHERE STILL MAY SEE A
MIX EARLY ON. THUS TRIMMED BACK POPS A LITTLE LATE TONIGHT BUT OVERALL
STILL A FEW ADDED INCHES WEST TO SEVERAL OUT EAST. WITH THE COASTAL LOW
DEEPENING AND PASSING JUST OFFSHORE LATE...EXPECT WINDS TO PICK UP
ESPCLY EAST OF THE BLUE RIDGE WHERE LOTS OF BLOWING/DRIFTING SNOW
LIKELY. APPEARS WINDS WILL STAY BELOW BLIZZARD CRITERIA BUT MAY NEED TO
CONSIDER FOR LATER TONIGHT OVER THE FAR NORTH/NE. AS THE FLOW TURNS
MORE NE WILL SEE TEMPS SLOWLY RISE IN THE 20S LATER TONIGHT AS SNOW
TURNS A BIT WETTER WITH THE INFLUX OF ATLANTIC MOISTURE.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 350 AM EST FRIDAY...
LOOKING TO SATURDAY MORNING...THE CENTER OF THE UPPER LEVEL LOW WILL
BE OVER CENTRAL NORTH CAROLINA...WHILE THE SURFACE REFLECTION OF THE
SYSTEM WILL BE LOCATED JUST EAST OF THE MOUTH OF CHESAPEAKE BAY...
RESULTING IN NORTHERLY WINDS ACROSS OUR AREA. WEATHER FORECAST
MODELS ARE HINTING THAT THE HEAVIEST PRECIPITATION BANDS WILL HAVE
EXITED OUR AREA BEFORE DAWN AS DRIER AIR WORKS INTO THE CENTRAL
APPALACHIANS...AND THAT SNOWFALL WILL TRANSITION FROM WIDESPREAD
LIGHT TO OCCASIONALLY MODERATE ACTIVITY AROUND DAWN...TO MORE OF A
SCATTERED UPSLOPE SNOW SHOWER VARIETY HEADING INTO THE EVENING.
BELIEVE THE HIGHEST SNOWFALL TOTALS FOR OUR AREA ON SATURDAY WILL
OCCUR ALONG THE INTERSTATE 64 CORRIDOR... WHERE AN ADDITIONAL 3 TO 5
INCHES ARE POSSIBLE...MAINLY THROUGH EARLY AFTERNOON. SNOWFALL
AMOUNTS WILL TAPER DOWN TO LESS THAN AN ADDITIONAL INCH OF NEW SNOW
ACROSS PORTIONS OF THE PIEDMONT IN NORTH CAROLINA. BY SATURDAY
EVENING...THE LOW PRESSURE SYSTEM WILL HAVE MOVED FAR ENOUGH AWAY
THAT THE ONLY REMAINING SNOWFALL WILL BE RAPIDLY DIMINISHING UPSLOPE
SNOW SHOWERS ALONG THE WESTERN RIDGES...WITH MINIMAL NEW
ACCUMULATION.
IN ADDITION TO NEW SNOWFALL ACCUMULATIONS...WILL ALSO BE CONCERNED
WITH GUSTY WINDS AS THE LOW PRESSURE SYSTEM DEEPENS THROUGH THE
DAY...CAUSING THE PRESSURE GRADIENT ACROSS OUR AREA TO TIGHTEN.
BELIEVE 20 TO 30 MPH GUSTS WILL BE COMMON THROUGH THE DAY...WITH 40+
MPH GUSTS POSSIBLE ACROSS THE HIGHER RIDGES. THESE GUSTY WINDS WILL
LIKELY RESULT IN WIDESPREAD BLOWING SNOW...WHICH MAY LEAD TO
LOCALIZED WHITEOUT CONDITIONS REGARDLESS OF WHAT IS FALLING FROM THE
SKY. WINDS WILL REMAIN GUSTY THROUGH SATURDAY NIGHT...BEFORE
DIMINISHING ON SUNDAY AS HIGH PRESSURE SETTLES ACROSS THE AREA FROM
THE WEST.
WITH THE DEPARTURE OF THE UPPER LEVEL LOW SATURDAY NIGHT...RIDGING
ALOFT WILL PUSH IN FROM THE WEST ON SUNDAY. DOWNSLOPE NORTHWESTERLY
WINDS...COMBINED WITH ABUNDANT SUNSHINE...WILL MAKE FOR WARMER
AFTERNOON TEMPERATURES AS HIGHS RANGE FROM THE UPPER 20S/LOW 30S
ACROSS SOUTHEAST WEST VIRGINIA...TO THE MID/UPPER 30S OVER THE
SOUTHSIDE. CLEAR SKIES WILL PERSIST INTO SUNDAY NIGHT...WHERE STRONG
RADIATIONAL COOLING DUE TO LIGHT WINDS AND ABUNDANT SNOW COVER WILL
CAUSE THE LOWER ELEVATIONS TO FALL INTO THE TEENS AND THE POSITIVE
SINGLE DIGITS...WHILE WINDS SHIFT SOUTHWESTERLY ALOFT...ALLOWING
WARMER AIR TO FILTER IN TO KEEP THE RIDGETOPS IN THE 20S.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 400 AM EST FRIDAY...
HIGH PRESSURE WILL PASS EAST OF THE REGION ON MONDAY WITH GENERALLY
FAIR WEATHER AND WARMER TEMPERATURES EXPECTED. OUR NEXT CHANCE OF
PRECIPITATION ARRIVES ON TUESDAY AS A LOW PRESSURE SYSTEM MOVES
THROUGH THE GREAT LAKES REGION AND PUSHES A FRONT INTO THE REGION
FROM THE WEST. UPSLOPE SNOW SHOWERS WILL THEN LINGER WEST OF THE
BLUE RIDGE AS SOMEWHAT COLDER AIR ARRIVES FOR THE MIDDLE OF NEXT
WEEK.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 1244 PM EST FRIDAY...
VERY POOR AVIATION CONDITIONS EXPECTED WITH WINTER STORM THROUGH
THE END OF VALID TAF PERIOD...
WINTERY MIXTURE OF SNOW WITH PACKETS OF SLEET AND FREEZING
RAIN WILL CONTINUE THIS AFTERNOON. CEILINGS AND VISIBILITIES WILL
REMAIN IN THE IFR RANGE FOR MOST OF THE AREA WITHIN A COUPLE
HOURS OF LIFR CIGS/VSBYS IN MODERATE TO HEAVY SNOW AND FOG.
SOME DECREASE IN PRECIPITATION MAY OCCUR LATE IN THE DAY AS THE
FIRST WAVE MOVES OFF TO THE NORTHEAST OF THE REGION. LIFR CEILINGS
WILL BE POSSIBLE THROUGH THE EVENING INTO TONIGHT IN SNOW AND
FOG. WINDS WILL TREND NORTHEAST TO EAST AT 10 TO 20 KT RANGE
THIS AFTERNOON INTO TONIGHT. WINDS WILL ALSO BECOME GUSTY ESPCLY
FROM THE BLUE RIDGE EAST BY TONIGHT WITH GUSTS TO 25-30 KTS
POSSIBLE AROUND KLYH.
WINTER STORM CONTINUES TONIGHT INTO SATURDAY WITH WIDESPREAD SUB
VFR CONDITIONS ALTHOUGH EXPECTING WIDESPREAD SNOWFALL TO TAPER OFF
TONIGHT ACROSS SOUTHERN AND WESTERN SECTIONS. SNOW SHOWERS AND
SNOW FLURRIES ARE POSSIBLE SATURDAY ESPECIALLY IN THE WESTERN
MOUNTAINS. BLOWING SNOW WILL HINDER AVIATION OPERATIONS
TONIGHT INTO SATURDAY.
LOW TO MEDIUM CONFIDENCE IN CIGS AND VSBYS THROUGH THE TAF VALID
PERIOD. MEDIUM TO HIGH CONFIDENCE IN WIND DIR/SPEED THROUGH THE
TAF VALID PERIOD.
EXTENDED DISCUSSION...
THIS SYSTEM IS LIKELY TO RESULT IN LITTLE TO NO AIR TRAVEL IN OUR
REGION TODAY- SATURDAY WITH AIRPORTS CLOSED. BY SUNDAY WE ARE
GOING TO BE UNDER INCREASING HIGH PRESSURE WITH VFR LIKELY INTO
MONDAY. ANOTHER COLD FRONT MAY BRING THE NEXT CHANCE FOR
PRECIPITATION INCLUDING SUB-VFR CONDITIONS ON TUESDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WINTER STORM WARNING UNTIL 6 AM EST SUNDAY FOR VAZ007-009>020-
022>024-032>035-043>047-058-059.
NC...WINTER STORM WARNING UNTIL 6 AM EST SUNDAY FOR NCZ001>006-
018>020.
WV...WINTER STORM WARNING UNTIL 6 AM EST SUNDAY FOR WVZ042>044-507-
508.
&&
$$
SYNOPSIS...JH/KK
NEAR TERM...JH/KK
SHORT TERM...NF
LONG TERM...NF
AVIATION...JH/KK
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1117 AM MST FRI JAN 22 2016
.UPDATE...
ISSUED AT 1115 AM MST FRI JAN 22 2016
CANCELLED THE DENSE FOG ADVISORY FOR BOX BUTTE COUNTY AS
VISIBILITIES HAVE RISEN ABOVE 2SM AT AIA OVER THE PAST HOUR.
LOWERED HIGH TEMPS FOR THIS AFTERNOON OVER THE NORTHERN NEBRASKA
PANHANDLE AS LOW CLOUDS/FOG HAS BEEN PERSISTENT THROUGH THE
MORNING OUT THERE.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 414 AM MST FRI JAN 22 2016
A LOCALIZED AREA OF DENSE FOG DEVELOPED AROUND KAIA LAST EVENING AND
HAS PERSISTED THROUGH THE NIGHT. RAP BUFKIT SOUNDINGS SHOW EXCELLENT
LLVL SATURATION AND VERY LIGHT NEAR-SFC FLOW THROUGH 16Z...SO DO NOT
BELIEVE FOG WILL DISSIPATE ANYTIME SOON. ISSUED A DENSE FOG ADVISORY
FOR BOX BUTTE COUNTY UNTIL 9 AM MST. PATCHY FOG IS ALSO OCCURRING IN
OTHER PORTIONS OF THE PANHANDLE...BUT NOT AS DENSE. NO MAJOR WEATHER
CONCERNS THROUGH SATURDAY WITH UPPER-LEVEL RIDGING IN PLACE. IT WILL
BE QUITE MILD ALONG/EAST OF THE LARAMIE RANGE ON FRIDAY AND SATURDAY
AFTERNOONS WITH FAVORABLE DOWNSLOPING AND H7 TEMPS OF +1C TO +3C. WE
SHOULD SEE CONSISTENT BREEZY CONDITIONS IN THE ARLINGTON AREA AS 700
MB FLOW REMAINS BETWEEN 30 AND 40 KTS AND THE CAG-CPR GRADIENT STAYS
AROUND 40 METERS. BEST CHANCE FOR HIGH WINDS IN THE WIND PRONE AREAS
WOULD BE BETWEEN 09Z AND 15Z SAT AS THE NAM 850 HPA CAG-CPR GRADIENT
CLIMBS ABOVE 50 METERS...BUT DO NOT THINK WINDS ALOFT UNDER 45 KNOTS
WILL SUPPORT WARNING-CRITERIA GUSTS. SOUTHWEST FLOW ALOFT IS PROGGED
TO INCREASE ON SATURDAY IN ADVANCE OF A PROGRESSIVE SHORTWAVE TROUGH
EXPECTED TO TRACK ACROSS THE CWA FROM SAT NIGHT THROUGH MON...WITH A
SURFACE COLD FROPA ON SUN AM. BEST PRECIP CHANCES WILL BE POST-FROPA
AFTER 12Z SUN...BUT WILL LIKELY BEGIN SLIGHTLY EARLIER ALONG/WEST OF
THE LARAMIE RANGE. WINTER WEATHER ADVISORIES COULD BE NEEDED FOR THE
MOUNTAINS AT SOME POINT WITH GFS/NAM BOTH SHOWING QPF AMOUNTS AROUND
0.5 INCH OWING TO FAVORABLE OROGRAPHICS. AMOUNTS SHOULD GENERALLY BE
LESS THAN 3 INCHES FOR MOST LOWER-ELEVATION AREAS.
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 414 AM MST FRI JAN 22 2016
UPPER RIDGE AXIS ALONG THE WEST COAST WILL YIELD PERSISTENT NW
FLOW OVR THE NRN ROCKIES/PLAINS NEXT WEEK. ASIDE FROM SOME LIGHT
SNOWS OVER THE SNOWY AND SIERRA MADRE RANGES ON MONDAY...EXPECT
GENERALLY DRY CONDITIONS TO PREVAIL FOR THE REMAINDER NEXT WEEK.
BREEZY TO LOCALLY WINDY CONDITIONS WILL BE THE MAIN STORY. ON
MONDAY/TUESDAY...MODELS PROG 20-30 KNOTS AT THE TOP OF THE ML...
YIELDING WIND GUSTS THAT WILL REACH 30-40 MPH DURING THE AFTERNOON
HOURS. THESE WINDS WILL COMBINE WITH HIGH TEMPERATURES THAT WILL
ONLY REACH THE 30S TO MAKE IT FEEL 10-20 DEGREES COLDER. MODELS
PROG KCAG-KCPR GRADIENTS TO PEAK WEDNESDAY MORNING AT 50-55 METERS
WHICH MAY YIELD A MARGINAL HIGH WIND EVENT FOR THE USUALLY WINDY
AREAS OF SOUTHEAST WYOMING. WARMER TEMPERATURES RETURN WED-FRI
WITH HIGHS REACHING INTO THE 30S WEST OF THE LARAMIE RANGE WITH
40S/LOW 50S ACROSS THE ERN PLAINS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1050 AM MST FRI JAN 22 2016
FOG/STRATUS WILL CONTINUE TO LIFT AT KAIA AND KCDR OVER THE NEXT
FEW HOURS...LIKELY BECOMING VFR AND REMAINING SO THROUGH THE
REST OF THE PERIOD. VFR CONDITIONS WILL PERSIST ELSEWHERE. BREEZY
WESTERLY WINDS WILL OCCUR ALONG AND WEST OF THE LARAMIE RANGE
THROUGH SATURDAY...WITH LIGHT WINDS ELSEWHERE.
&&
.FIRE WEATHER...
ISSUED AT 414 AM MST FRI JAN 22 2016
WARM AND DRY CONDITIONS ARE LIKELY FOR FRI/SAT WITH DAYTIME HIGHS IN
THE 40S AND 50S OVER THE HIGH PLAINS. AFTERNOON HUMIDITY VALUES WILL
LIKELY REMAIN OUTSIDE OF CRITICAL THRESHOLDS...BUT COULD DROP AS LOW
AS 25 PERCENT. BREEZY TO LOCALLY WINDY CONDITIONS CAN BE EXPECTED IN
AREAS ALONG/WEST OF THE LARAMIE RANGE THROUGH THE WEEKEND. A WEATHER
DISTURBANCE AND ASSOCIATED COLD FRONT WILL MOVE ACROSS THE REGION ON
SATURDAY NIGHT AND SUNDAY...BRINGING COOLER AIR AND WIDESPREAD LIGHT
SNOW.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...ZF
SHORT TERM...CLH
LONG TERM...CAH
AVIATION...RJM
FIRE WEATHER...CLH
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1050 AM MST FRI JAN 22 2016
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 414 AM MST FRI JAN 22 2016
A LOCALIZED AREA OF DENSE FOG DEVELOPED AROUND KAIA LAST EVENING AND
HAS PERSISTED THROUGH THE NIGHT. RAP BUFKIT SOUNDINGS SHOW EXCELLENT
LLVL SATURATION AND VERY LIGHT NEAR-SFC FLOW THROUGH 16Z...SO DO NOT
BELIEVE FOG WILL DISSIPATE ANYTIME SOON. ISSUED A DENSE FOG ADVISORY
FOR BOX BUTTE COUNTY UNTIL 9 AM MST. PATCHY FOG IS ALSO OCCURRING IN
OTHER PORTIONS OF THE PANHANDLE...BUT NOT AS DENSE. NO MAJOR WEATHER
CONCERNS THROUGH SATURDAY WITH UPPER-LEVEL RIDGING IN PLACE. IT WILL
BE QUITE MILD ALONG/EAST OF THE LARAMIE RANGE ON FRIDAY AND SATURDAY
AFTERNOONS WITH FAVORABLE DOWNSLOPING AND H7 TEMPS OF +1C TO +3C. WE
SHOULD SEE CONSISTENT BREEZY CONDITIONS IN THE ARLINGTON AREA AS 700
MB FLOW REMAINS BETWEEN 30 AND 40 KTS AND THE CAG-CPR GRADIENT STAYS
AROUND 40 METERS. BEST CHANCE FOR HIGH WINDS IN THE WIND PRONE AREAS
WOULD BE BETWEEN 09Z AND 15Z SAT AS THE NAM 850 HPA CAG-CPR GRADIENT
CLIMBS ABOVE 50 METERS...BUT DO NOT THINK WINDS ALOFT UNDER 45 KNOTS
WILL SUPPORT WARNING-CRITERIA GUSTS. SOUTHWEST FLOW ALOFT IS PROGGED
TO INCREASE ON SATURDAY IN ADVANCE OF A PROGRESSIVE SHORTWAVE TROUGH
EXPECTED TO TRACK ACROSS THE CWA FROM SAT NIGHT THROUGH MON...WITH A
SURFACE COLD FROPA ON SUN AM. BEST PRECIP CHANCES WILL BE POST-FROPA
AFTER 12Z SUN...BUT WILL LIKELY BEGIN SLIGHTLY EARLIER ALONG/WEST OF
THE LARAMIE RANGE. WINTER WEATHER ADVISORIES COULD BE NEEDED FOR THE
MOUNTAINS AT SOME POINT WITH GFS/NAM BOTH SHOWING QPF AMOUNTS AROUND
0.5 INCH OWING TO FAVORABLE OROGRAPHICS. AMOUNTS SHOULD GENERALLY BE
LESS THAN 3 INCHES FOR MOST LOWER-ELEVATION AREAS.
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 414 AM MST FRI JAN 22 2016
UPPER RIDGE AXIS ALONG THE WEST COAST WILL YIELD PERSISTENT NW
FLOW OVR THE NRN ROCKIES/PLAINS NEXT WEEK. ASIDE FROM SOME LIGHT
SNOWS OVER THE SNOWY AND SIERRA MADRE RANGES ON MONDAY...EXPECT
GENERALLY DRY CONDITIONS TO PREVAIL FOR THE REMAINDER NEXT WEEK.
BREEZY TO LOCALLY WINDY CONDITIONS WILL BE THE MAIN STORY. ON
MONDAY/TUESDAY...MODELS PROG 20-30 KNOTS AT THE TOP OF THE ML...
YIELDING WIND GUSTS THAT WILL REACH 30-40 MPH DURING THE AFTERNOON
HOURS. THESE WINDS WILL COMBINE WITH HIGH TEMPERATURES THAT WILL
ONLY REACH THE 30S TO MAKE IT FEEL 10-20 DEGREES COLDER. MODELS
PROG KCAG-KCPR GRADIENTS TO PEAK WEDNESDAY MORNING AT 50-55 METERS
WHICH MAY YIELD A MARGINAL HIGH WIND EVENT FOR THE USUALLY WINDY
AREAS OF SOUTHEAST WYOMING. WARMER TEMPERATURES RETURN WED-FRI
WITH HIGHS REACHING INTO THE 30S WEST OF THE LARAMIE RANGE WITH
40S/LOW 50S ACROSS THE ERN PLAINS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1050 AM MST FRI JAN 22 2016
FOG/STRATUS WILL CONTINUE TO LIFT AT KAIA AND KCDR OVER THE NEXT
FEW HOURS...LIKELY BECOMING VFR AND REMAINING SO THROUGH THE
REST OF THE PERIOD. VFR CONDITIONS WILL PERSIST ELSEWHERE. BREEZY
WESTERLY WINDS WILL OCCUR ALONG AND WEST OF THE LARAMIE RANGE
THROUGH SATURDAY...WITH LIGHT WINDS ELSEWHERE.
&&
.FIRE WEATHER...
ISSUED AT 414 AM MST FRI JAN 22 2016
WARM AND DRY CONDITIONS ARE LIKELY FOR FRI/SAT WITH DAYTIME HIGHS IN
THE 40S AND 50S OVER THE HIGH PLAINS. AFTERNOON HUMIDITY VALUES WILL
LIKELY REMAIN OUTSIDE OF CRITICAL THRESHOLDS...BUT COULD DROP AS LOW
AS 25 PERCENT. BREEZY TO LOCALLY WINDY CONDITIONS CAN BE EXPECTED IN
AREAS ALONG/WEST OF THE LARAMIE RANGE THROUGH THE WEEKEND. A WEATHER
DISTURBANCE AND ASSOCIATED COLD FRONT WILL MOVE ACROSS THE REGION ON
SATURDAY NIGHT AND SUNDAY...BRINGING COOLER AIR AND WIDESPREAD LIGHT
SNOW.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...DENSE FOG ADVISORY UNTIL 11 AM MST THIS MORNING FOR NEZ003.
&&
$$
SHORT TERM...CLH
LONG TERM...CAH
AVIATION...RJM
FIRE WEATHER...CLH