Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 01/19/13
AREA FORECAST DISCUSSION
NWS ALBANY NY
434 PM EST THU JAN 17 2013
.SYNOPSIS...
A COLD FRONT WILL SETTLE SOUTH OF THE REGION TONIGHT. A STORM
SYSTEM PASSING WELL OFF THE MID ATLANTIC COAST WILL BRING SOME
CLOUDS TO THE REGION THIS EVENING...AND PERHAPS A FEW SNOW SHOWERS
OR FLURRIES FOR SOUTHEAST AREAS. HIGH PRESSURE WILL BUILD IN FOR
FRIDAY...BRINGING FAIR BUT COLD CONDITIONS. ANOTHER STORM SYSTEM
WILL APPROACH FROM THE GREAT LAKES FRIDAY NIGHT AND
SATURDAY...BRINGING CLOUDS AND SOME SNOW SHOWERS...AND FOLLOWED BY
ANOTHER SURGE OF VERY COLD AIR FOR SUNDAY THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AS OF 430 PM EST...A COLD FRONT CONTINUES TO SETTLE SOUTHWARD
ACROSS THE REGION...AND IS CURRENTLY APPROACHING THE SE CATSKILLS
INTO THE MID HUDSON VALLEY REGION. LITTLE IN THE WAY OF
PRECIPITATION IS ASSOCIATED WITH THIS FRONT AT THIS TIME.
MEANWHILE...TEMPS ARE GRADUALLY FALLING INTO THE TEENS ACROSS THE
SOUTHERN ADIRONDACKS...AND THROUGH THE 20S FOR AREAS NORTH OF THE
MOHAWK RIVER VALLEY AND CAPITAL DISTRICT.
A THICK CANOPY OF HIGH AND MID LEVEL CLOUDS CONTINUES TO COVER
MOST OF THE REGION...IN ASSOCIATION WITH MOISTURE STREAMING
NORTHWARD IN ASSOCIATION WITH THE STRONG UPPER LEVEL STORM SYSTEM
TRAVERSING THE SOUTHEAST STATES. IN ADDITION...SOME LOWER CLOUDS
CONTINUE TO AFFECT AREAS FURTHER N AND W IN ASSOCIATION WITH LOW
LEVEL COLD ADVECTION...AND SOME ADDITIONAL MOISTURE CONTRIBUTED
FROM THE GREAT LAKES.
THE LATEST HRRR INDICATES THAT AS THE MID LEVEL CLOUDS THICKEN
MORE THIS EVENING...THERE COULD BE SOME FEEDER/SEEDER PROCESSES
WITH THE LOWER CLOUD DECK WHICH COULD PRODUCE SOME LIGHT SNOW
SHOWERS OR FLURRIES FOR AREAS MAINLY SOUTH AND SOUTHEAST OF THE
GREATER CAPITAL DISTRICT...PARTICULARLY ACROSS PORTIONS OF THE
MID HUDSON VALLEY...EXTREME SOUTHERN BERKSHIRES...AND NW CT. HAVE
INCLUDED MENTION OF FLURRIES OVERNIGHT IN MOST OF THESE
AREAS...ALONG WITH MENTION OF SLIGHT CHC POPS FOR SNOW SHOWERS
ACROSS THE MID HUDSON VALLEY AND NW CT. IN THIS REGION...CAN NOT
COMPLETELY RULE OUT A COATING OF SNOW IN SOME AREAS BY DAYBREAK.
THE HIGH/MID LEVEL CLOUD CANOPY SHOULD GRADUALLY THIN FROM NW TO
SE...STARTING AROUND MIDNIGHT...AND CONTINUING THROUGH DAYBREAK.
THIS RAISES A RATHER CHALLENGING TEMPERATURE FORECAST...ESP FOR
NORTHERN AREAS...AS ANY PERIOD OF CLEAR SKIES ALONG WITH
DECREASING WIND AND AT LEAST SOME SNOW COVER COULD LEAD TO A QUICK
DROP IN TEMPS. HAVE SIDED WITH...OR EVEN WENT A BIT BELOW THE
COLDER MOS FOR MIN TEMPS OVERNIGHT ACROSS NORTHERN AREAS...WITH
WIDESPREAD SUBZERO MINS EXPECTED. FURTHER SOUTH...HAVE SIDED WITH
THE COLDER MET MOS IN MOST AREAS...ALTHOUGH TOOK A BLEND OF THE
MAV/MET MOS ACROSS SOUTHERN AREAS WHERE CLOUDS COULD LAST LONGER.
ACROSS NORTHERN AREAS WHERE SUBZERO TEMPS ARE EXPECTED...WINDS
SHOULD DROP TO BELOW 5 MPH...AND THEREFORE NO WIND CHILL HEADLINES
ARE INDICATED.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
FRIDAY...A PERIOD OF MOSTLY SUNNY SKIES IS EXPECTED THROUGH MUCH
OF THE DAY IN VALLEY AREAS...BEFORE A COMBINATION OF WARM
ADVECTION...AND SOME LAKE MOISTURE WITH A BACKING NORTHWEST TO
WEST WIND ALLOW CLOUDS TO REDEVELOP LATER IN THE DAY ACROSS THE
WESTERN MOHAWK VALLEY/ADIRONDACKS...AND PERHAPS ACROSS THE
SCHOHARIE VALLEY/HELDERBERGS. HAVE SIDED WITH THE COLDER SIDE OF
MOS FOR MAX TEMPS...WITH GENERALLY 20-25 IN VALLEY AREAS FROM
ALBANY N AND W...AND 25-30 IN VALLEY AREAS SOUTH OF ALBANY...WHILE
MOST HIGHER ELEVATIONS ONLY REACH THE TEENS. SOME SNOW SHOWERS ARE
EXPECTED TO DEVELOP BY AFTERNOON ACROSS THE WESTERN ADIRONDACKS
AND MOHAWK VALLEY REGION.
FRIDAY NIGHT-SAT...AS A STRONG CLIPPER TYPE SYSTEM APPROACHES FROM
THE GREAT LAKES REGION...A SURGE OF MID LEVEL WARM ADVECTION IS
EXPECTED TO PRODUCE ABUNDANT CLOUDS FOR LATER FRI NIGHT INTO AT
LEAST SAT MORNING...AND PERHAPS WELL INTO SAT AFTERNOON ACROSS
NORTHERN AREAS...WHERE ISENTROPIC LIFT WILL PERSIST. ALSO...AREAS
OF SNOW SHOWERS AND FLURRIES WILL OCCUR IN NORTHERN AREAS FRI NT
INTO SAT AM. SOME COATINGS WILL BE POSSIBLE IN VALLEY AREAS NORTH
OF THE CAPITAL REGION...WITH PERHAPS 1-4 INCHES ACROSS PORTIONS OF
THE WESTERN MOHAWK VALLEY/ADIRONDACK REGION. TEMPS FRI NT SHOULD
INITIALLY FALL QUICKLY...BEFORE RISING LATER IN THE EVENING
THROUGH DAYBREAK SAT. HAVE GENERALLY WENT WITH THE COLDER SIDE OF
GUIDANCE FOR MINS...ESP ACROSS NORTHERN AREAS. ON SAT...DESPITE A
DEVELOPING SOUTHWEST FLOW...CLOUDS AND A LOW LEVEL INVERSION MAY
PREVENT TEMPS FROM RISING TO THE WARMER MAV MOS NUMBERS. HAVE
SIDED WITH THE COOLER MET MOS IN MOST AREAS...AND HAVE EVEN
UNDERCUT BY A FEW ACROSS NORTHERN AREAS...WITH MID 30S EXPECTED
ACROSS THE SOUTHERN ADIRONDACKS AND LAKE GEORGE/SARATOGA
REGION...AND UPPER 30S TO LOWER 40S IN VALLEY AREAS FURTHER SOUTH.
HOWEVER...ACROSS PORTIONS OF THE SE CATSKILLS AND MID HUDSON
VALLEY...MORE SUNSHINE...AND A GUSTY DOWNSLOPING SW FLOW SHOULD
BOOST TEMPS INTO THE 45-50 RANGE.
SAT NT...OUR REGION SHOULD REMAIN WITHIN THE WARM SECTOR OF THE
APPROACHING CLIPPER. AS A COLD FRONT APPROACHES FROM THE NORTHWEST
LATER AT NIGHT...CLOUDS AND SOME SNOW SHOWERS SHOULD DEVELOP BY
DAYBREAK SUNDAY ACROSS N/W AREAS...WHERE CHC POPS ARE INDICATED.
INCREASING CLOUDS...AND A BRISK S/SW WIND SHOULD PREVENT TEMPS
FROM FALLING MUCH...AND THEREFORE HAVE GONE ABOVE MOS...WITH UPPER
20S TO MID 30S EXPECTED REGIONWIDE FOR MINS.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
...BELOW NORMAL TEMPERATURES WILL PERSIST THROUGH THE EXTENDED
PERIOD.
NORMAL TEMPERATURES FOR THE PERIOD JAN 20TH THROUGH 23RD:
ALBANY: HIGHS AROUND 30. LOWS IN THE MID TEENS.
GLENS FALLS: HIGHS IN THE UPPER 20S. LOWS IN THE SINGLE DIGITS.
POUGHKEEPSIE: HIGHS IN THE MID 30S. LOWS IN THE MID TEENS.
BENNINGTON: HIGHS AROUND 30. LOWS NEAR 10.
PITTSFIELD: HIGHS IN THE UPPER 20S. LOWS NEAR 10.
MODEL GUIDANCE CONTINUES TO BE IN GOOD AGREEMENT IN REGARDS TO THE
LONGWAVE PATTERN FOR THE PERIOD WITH A LARGE TROUGH COVERING THE
EASTERN 2/3 OF THE CONUS WITH SHORT WAVES ROTATING ABOUT AN UPPER
LOW OVER HUDSON/S BAY CANADA AND RIDGING ALONG THE WEST COAST.
NOW...EVEN THE DIFFERENCES IN THE LONG RANGE MODELS WERE IN PRETTY
GOOD AGREEMENT.
A POTENT CLIPPER...TRACKING ACROSS THE GREAT LAKES...WILL DRIVE AN
ARCTIC FRONT ACROSS THE REGION ON SUNDAY. THIS FRONT STILL LOOKS TO
HAVE DECENT UPPER LEVEL DYNAMICS AND A SHARP THERMAL GRADIENT
ASSOCIATED WITH IT...SO A ROUND OF SNOW SHOWERS/SQUALLS IS POSSIBLE
WITH THE FRONTAL PASSAGE. A SOUTH OR SOUTHWEST WIND WILL SHIFT
WEST-NORTHWEST AND DRIVE H850 TEMPS FROM ABOUT -2C EARLY...TO NEARLY
-20C BY LATE IN THE DAY! TEMPERATURES MIGHT ACTUALLY SPIKE IN THE
MORNING...THEN DROP DURING THE AFTERNOON ACROSS THE ENTIRE REGION.
HOWEVER THIS FAR OUT...WE JUST USED THE CLIMATOLOGICAL DIURNAL TREND
IN THE GRIDS SINCE A CHANGE IN THE ARRIVAL OF THIS REALLY COLD AIR
WOULD CHANGE HOURLY TEMPERATURES QUITE A BIT.
BY SUNDAY NIGHT WITH 850 MB TEMPERATURES LOOK TO HAVE DROPPED TO
BETWEEN -15 TO -20 C ACROSS THE FORECAST AREA. A WESTERLY WIND OF 10
TO 20 MPH WILL MAKE IT FEEL EVEN COLDER. WIND CHILL VALUES MAY REACH
ADVISORY CRITERIA (-20F) ACROSS THE SOUTHERN ADIRONDACKS AND THE
HIGHER TERRAIN OF SOUTHERN VERMONT. WILL HAVE MENTION IN OUR
HAZARDOUS WEATHER OUTLOOK.
SHORT WAVES ROTATING ABOUT THE UPPER LOW WILL BRING REINFORCING
SHOTS OF COLDER AIR TO THE REGION AS ADDITIONAL CLIPPER SYSTEMS MOVE
THROUGH MONDAY THROUGH WEDNESDAY. THIS WILL KEEP CLOUDS AND THE
THREAT OF SNOW SHOWERS IN THE FORECAST...ESPECIALLY DOWNWIND OF LAKE
ONTARIO. AT THIS POINT THE SYSTEMS WILL HAVE LIMITED MOISTURE
ASSOCIATED WITH THEM SO ANY PRECIPITATION/SNOW SHOULD BE LIGHT.
ONE THING TO WATCH ON TUESDAY. IT STILL APPEARS THAT A STORM IN THE
SOUTHERN JETSTREAM SHOULD MOVE WELL SOUTH AND EAST OF OUR REGION OUT
INTO THE OCEAN. HOWEVER...EVEN IF IT DOES...INTERACTION BETWEEN THIS
SYSTEM AND A POSSIBLE SHORTWAVE REINFORCING THE TROUGH OVER
US...MIGHT PRODUCE BROAD ASCENT TO GIVE OUR ENTIRE AREA LIGHT SNOW
OR SNOW SHOWERS TUESDAY. AGAIN...THIS SCENARIO IS NOT ETCHED IN
STONE...AND FOR NOW...ONLY WENT SLIGHT CHANCES IN AREAS OUTSIDE THE
ELEVATED TERRAIN TO THE WEST OF THE HUDSON VALLEY WHERE WE WENT LOW
POPS DUE TO MORE LAKE AVAILABLE EFFECT MOISTURE.
AS THE AFOREMENTIONED OCEAN STORM WINDS UP LATE TUESDAY...IT LOOKS
TO DRIVE ANOTHER SURGE OF ARCTIC AIR OUR WAY FOR TUESDAY...WITH SOME
INDICATIONS THAT H850 TEMPERATURES COULD BE EVEN COLDER (IN THE -20C
TO -25C RANGE). OF COURSE THIS NEW SURGE OF ARCTIC AIR COULD COME
WITH ANOTHER ROUND OF SNOW SHOWERS/SNOW SQUALLS AND LAKE EFFECT
SNOW.
INITIALLY THE ENVIRONMENT LOOKS SOMEWHAT SHEARED FOR SIGNIFICANT
LAKE EFFECT ACCUMULATIONS. HOWEVER...BY LATE TUESDAY INTO
WEDNESDAY...THE FLOW LOOKS TO BECOME MORE CYCLONIC WITH LESS SHEAR
AND VERY COLD AIR PRODUCING POTENTIAL EXTREME SLANTWISE INSTABILITY
OFF LAKE ONTARIO. WE WILL MONITOR THE LAKE EFFECT POTENTIAL THROUGH
THE PERIOD.
TEMPERATURES WILL TO TOP OUT IN THE 30S TO NEAR 40 SUNDAY IN THE
HUDSON VALLEY (THE WARMEST READINGS AROUND POUGHKEEPSIE). HIGHER
TERRAIN WILL SEE HIGHS ONLY 25-30. AGAIN...TEMPERATURES COULD DROP
DURING THE AFTERNOON.
OVERNIGHT LOWS SUNDAY NIGHT THROUGH WEDNESDAY LOOK TO TUMBLE TO THE
TEENS FROM THE TRI-CITIES SOUTHWARD...AROUND ZERO TO SINGLE NUMBERS
FURTHER NORTH AND WEST. THIS ASSUMES SOME WIND (AS OPPOSED TO CALM
CONDITIONS). IF THE WIND WERE TO DECOUPLE ANY OF THESE NIGHTS WITH
EVEN A PARTIALLY CLEAR SKY...OVERNIGHT LOWS COULD BE A LOT
COLDER...ESPECIALLY UP NORTH.
DAYTIME HIGHS MONDAY THROUGH THURSDAY LOOK TO LOOK TO BE 20-25 IN
THE HUDSON VALLEY FROM ALBANY SOUTHWARD...TEENS FURTHER NORTH...WITH
SOME READINGS AROUND 10 ACROSS THE ADIRONDACKS. THESE VALUES MIGHT
NOT BE COLD ENOUGH BUT AS WE GET CLOSER TO THIS TIME PERIOD...WE
WILL ADJUST THEM AS NEEDED.
&&
.AVIATION /21Z THURSDAY THROUGH TUESDAY/...
A COLD FRONT HAS PASSED KGFL...AND WILL PASS KALB EARLY IN THE
AFTERNOON....KPOU NOT UNTIL LATE AFTERNOON OR EVENING. DESPITE THE
COLD FRONTAL PASSAGE...VFR CONDITIONS WILL PREVAIL.
THE MAIN FACTOR WITH THE COLD FRONT WILL BE A WIND SHIFT FROM W TO
N. THE WIND WILL BE GUSTY AT TIMES UP TO 20 MPH...ESPECIALLY WITH
THE PASSAGE OF THE FRONT.
BROKEN VFR CIGS AT KGFL/KALB AND KPSF WILL BE IN THE 3500-4000 FEET
AGL UNTIL EARLY EVENING. AT KPOU...MOST CLOUDS WILL NOT BE
"SENSIBLE" (OVER 12,000 FEET).
TONIGHT...MOST IF NOT ALL OF THE SENSIBLE CLOUDS WILL BE GONE. THE
ONLY EXCEPTION IS SOME VFR CIGS AROUND 4000 FEET MIGHT APPROACH KGFL
FROM MOISTURE OF LAKE CHAMPLAIN AT TIMES THROUGH EARLY FRIDAY.
A NORTH WIND WILL CONTINUE AROUND 10KTS THROUGH EARLY
TOMORROW...BECOMING LIGHTER AND MORE VARIABLE BY LATE IN THE DAY.
OUTLOOK...
FRI-SAT...VFR...NO SIG WX.
SUN...MAINLY VFR. CHC -SHSN.
MON...VFR. SLIGHT CHC -SHSN.
TUE...VFR. CHC SUB-VFR CIG -SHSN.
&&
.HYDROLOGY...
MAINLY DRY AND COLD WEATHER WILL OCCUR OVER THE NEXT FIVE DAYS.
WHILE SOME SNOW SHOWERS ARE POSSIBLE OVER THE NEXT FEW DAYS ACROSS
NORTHERN AREAS...PRECIPITATION AMOUNTS WILL BE LIGHT AND IN THE
FORM OF SNOW. COLD TEMPERATURES...ESPECIALLY EARLY NEXT
WEEK...WILL CAUSE RIVER AND LAKE ICE TO FORM AND THICKEN.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...KL/HWJIV/FRUGIS
NEAR TERM...KL
SHORT TERM...KL
LONG TERM...HWJIV/IAA
AVIATION...HWJIV
HYDROLOGY...KL/FRUGIS
AREA FORECAST DISCUSSION
NWS ALBANY NY
910 AM EST THU JAN 17 2013
.SYNOPSIS...
AN ARCTIC COLD FRONT WILL CROSS THE REGION TODAY. THIS FRONT WILL
BRING SOME SNOW SHOWERS TO THE ADIRONDACKS FOR THIS
MORNING...FLURRIES ELSEWHERE. THEN...IT WILL TURN COLD AND BLUSTERY
TONIGHT AND TOMORROW. A WARM FRONT WILL ALLOW TEMPERATURES TO RETURN
ABOVE NORMAL AGAIN BRIEFLY FOR SATURDAY BEFORE ANOTHER STRONG COLD
FRONT RETURNS COLD WEATHER TO THE AREA FOR SUNDAY INTO EARLY NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 900 AM...SNOW SHOWERS OR FLURRIES HAVE EXPANDED WELL PAST THE
ADIRONDACKS PARK...INTO THE GREATER CAPITAL DISTRICT. THESE SNOW
SHOWERS/FLURRIES ARE WELL AHEAD OF AN ARCTIC FRONT...STILL NORTH OF
THE REGION...POISED TO COME DOWN DURING THE DAY...PROBABLY NOT
CLEARING OUR SOUTHERN AREAS UNTIL THIS EVENING.
MEANWHILE...TEMPERATURES HAVE ETCHED UPWARD AHEAD OF THE FRONT...SO
HAD TO MAKE ADJUSTMENTS ON HIGH TEMPS TODAY...ONLY BY A COUPLE OF
DEGREES. THINKING IS TEMPERATURES SHOULD LEVEL OFF LATER THIS
MORNING (EXCEPT MID HUDSON VALLEY AND LOWER LITCHFIELD) WHERE THEY
WILL RISE INTO THE AFTERNOON BEFORE FALLING.
SNOW SHOWERS SHOULD ONLY ADD MINOR ACCUMULATIONS...OF AROUND AN INCH
OR LESS IN SPOTS ACROSS THE ADIRONDACKS. LITTLE OR NO ACCUMULATIONS
EXPECTED ELSEWHERE.
THE ARCTIC BOUNDARY SHOULD CROSS THE ADIRONDACK REGION BY THE MID
MORNING HOURS. AS THIS BOUNDARY CONTINUES TO MOVE ACROSS THE
REGION...SNOW SHOWERS WILL BECOME MORE ISOLD. 00Z NAM12
GUIDANCE...AS WELL AS THE LOCAL HIRES WRF AND THE 3KM HRRR GUIDANCE
ALL SHOW THIS BAND OF SNOW SHOWERS FALLING APART AS IT REACHES THE
MOHAWK VALLEY/SARATOGA AREA/SRN VT/CAPITAL REGION AROUND NOON DUE TO
LITTLE MOISTURE AVAILABLE...SO WILL CONTINUE WITH ONLY GO WITH
SLIGHT CHC POPS OUTSIDE THE ADIRONDACKS. WHILE THERE MAY BE A FEW
FLURRIES FOR THESE VALLEY AREAS LATE THIS MORNING/EARLY THIS
AFTN...NO SNOW ACCUMULATION IS ANTICIPATED. THE FRONT WILL THEN
CONTINUE SOUTHEAST ACROSS THE CATSKILLS/MID HUDSON
VALLEY/BERKSHIRES/NW CT FOR THIS AFTN...BUT WITH NO PRECIP
ASSOCIATED WITH IT.
THE MAIN IMPACT WITH THIS FRONT WILL BE THE SHARP TEMPERATURE
GRADIENT. MAX TEMPS WILL OCCUR AHEAD OF THE FRONT...WITH TEMPS
RANGING FROM NEAR 20 IN THE ADIRONDACKS TO NEAR 40 IN THE MID
HUDSON VALLEY. ONCE THE FRONT MOVES THROUGH...TEMPS WILL RAPIDLY
FALL...ALONG WITH GUSTY W-NW WINDS. SOME WIND GUSTS...ESP IN AREAS
OF CHANNELED FLOW SUCH AS THE MOHAWK VALLEY/CAPITAL REGION...COULD
REACH UP TO 25 MPH. THIS WILL MAKE FOR A COLD AND BLUSTERY
AFTERNOON...ESP FROM THE CAPITAL REGION ON NORTH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
IN THE WAKE OF THE FRONT...850 HPA TEMPS PLUNGE TO -16 TO -21
DEGREES C ACROSS THE REGION. THIS WILL RESULT IN VERY COLD
TEMPERATURES TONIGHT. AS WINDS BECOME LIGHT...THE EXISTING SNOW
PACK WILL AID IN ALLOWING FOR COLD MIN TEMPS...WITH SINGLE DIGITS
TO TEENS FOR AREAS FROM THE MOHAWK VALLEY/CAPITAL REGION
SOUTHWARD. NORTHERN AREAS LOOK TO BE VERY COLD...WITH READINGS
BELOW ZERO ACROSS THE ADIRONDACKS/LAKE GEORGE/GLENS FALLS AREA AND
GREEN MTNS OF SRN VT. SOME PORTIONS OF THE CENTRAL ADKS MAY DROP
-10 TO -20 DEGREES F. WIND SPEEDS SHOULD DROP TO 5 MPH OR LESS
DURING THE COLDEST PERIODS ACROSS THE ADIRONDACKS SO NO WIND CHILL
ADVISORIES WILL BE ISSUED. HOWEVER...THESE COLD AMBIENT TEMPS WILL
STILL BE HAZARDOUS ENOUGH TO CAUSE FROSTBITE QUICKLY...SO BE SURE
TO TAKE EXTREME CAUTION IF YOU PLAN ON BEING IN THE BACK COUNTRY
DURING THE OVERNIGHT HOURS. DESPITE THE COLD TEMPS...IT WON/T BE
COMPLETELY CLEAR TONIGHT DUE TO THE UPPER TROUGH PASSING OVERHEAD
AND SOME PASSING CLOUDS WILL BE AROUND. HOWEVER...NO SNOW SHOWERS
ARE EXPECTED...ALTHOUGH SOME ICE CRYSTALS /DIAMOND DUST/ ARE
POSSIBLE ACROSS THE ADIRONDACKS DUE TO THE COLD TEMPS.
ON FRIDAY...A FEW LAKE EFFECT FLURRIES ARE POSSIBLE FOR FAR
WESTERN AREAS...BUT THE SHEAR ISN/T FAVORABLE FOR MUCH LAKE EFFECT
TO OCCUR. LITTLE TO NO SNOW ACCUMULATION IS EXPECTED FOR OUR
AREA. OTHERWISE...IT LOOKS TO REMAIN DRY WITH PARTLY TO MOSTLY
SUNNY SKIES. WARM AIR ADVECTION WILL BEGIN TO TAKE PLACE BY LATE
IN THE DAY AS A WARM FRONT STARTS TO MOVE NORTH FROM THE SOUTH.
MAX TEMPS ON FRIDAY WILL BE COLD WITH TEENS AND 20S ACROSS THE
AREA.
SOUTHERLY WINDS...AND WARMING TEMPS ALOFT...WILL ALLOW FOR FRI
NIGHT TO NOT BE AS COLD AS TONIGHT. IT WILL ONLY DROP A FEW
DEGREES FROM FRIDAY/S HIGHS ACROSS THE AREA...AND TEMPS MAY EVEN
HOLD STEADY OR RISE AT TIMES.
BY SATURDAY...THE REGION WILL BE BACK IN A WARM SECTOR...AND
ABOVE NORMAL TEMPS WILL RETURN...WITH 30S TO LOW 40S ACROSS THE
REGION. A CLIPPER SYSTEM WILL PASS ACROSS SOUTHERN CANADA...AND IT
MAY BE CLOSE ENOUGH TO BRING SOME LIGHT SNOW TO THE
ADIRONDACKS...ALTHOUGH THE BEST ACTIVITY LOOKS TO STAY NORTH OF
THE US/CANADIAN BORDER. OTHERWISE...SKIES WILL BE PARTLY TO MOSTLY
CLOUDY.
ANOTHER ARCTIC FRONT WILL START TO APPROACH THE AREA FOR SATURDAY
NIGHT. THE REGION SHOULD REMAIN OUT AHEAD OF IT THROUGH THE
OVERNIGHT HOURS...SO TEMPS SAT NIGHT WON/T BE COLD YET /MAINLY
20S/. SOME SNOW SHOWERS MAY AFFECT MAINLY WESTERN PARTS OF THE
REGION...ESP FOR THE LATE NIGHT HOURS.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
LOOKING AT A PERIOD OF BELOW NORMAL TEMPERATURES...
NORMAL TEMPERATURES FOR THE PERIOD JAN 20TH THROUGH 23RD:
ALBANY: HIGHS AROUND 30. LOWS IN THE MID TEENS.
GLENS FALLS: HIGHS IN THE UPPER 20S. LOWS IN THE SINGLE DIGITS.
POUGHKEEPSIE: HIGHS IN THE MID 30S. LOWS IN THE MID TEENS.
BENNINGTON: HIGHS AROUND 30. LOWS NEAR 10.
PITTSFIELD: HIGHS IN THE UPPER 20S. LOWS NEAR 10.
MODEL GUIDANCE IS IN AGREEMENT IN REGARDS TO THE LONGWAVE PATTERN
FOR THE PERIOD WITH A LARGE TROUGH COVERING THE EASTERN 2/3 OF THE
CONUS WITH SHORT WAVES ROTATING ABOUT AN UPPER LOW OVER HUDSON BAY
CANADA AND RIDGING ALONG THE WEST COAST. THE DIFFERENCES IN THE
MODELS ARE WITH THE TIMING OF THE SHORT WAVES AND ASSOCIATED FRONTAL
BOUNDARIES CROSSING THE REGION.
AN ARCTIC FRONT WILL CROSS THE REGION SUNDAY. THIS FRONT WILL HAVE
SOME DECENT UPPER LEVEL DYNAMICS AND A SHARP THERMAL GRADIENT
ASSOCIATED WITH IT...SO A ROUND OF SNOW SHOWERS/SQUALLS IS POSSIBLE
WITH THE FRONTAL PASSAGE. WINDS WILL SHIFT WEST-NORTHWEST AND BECOME
BRISK AND GUSTY IN ITS WAKE AND TEMPERATURES SHOULD DROP DURING THE
AFTERNOON.
IT WILL GET COLD SUNDAY NIGHT WITH 850 MB TEMPERATURES DROPPING TO
-15 TO -20 C ACROSS THE FORECAST AREA. WESTERLY WINDS OF 10 TO 20
MPH WILL MAKE IT FEEL EVEN COLDER. WIND CHILL VALUES MAY REACH
ADVISORY CRITERIA (-20F) ACROSS THE SOUTHERN ADIRONDACKS...HAVE
MENTION IN OUR HAZARDOUS WEATHER OUTLOOK.
SHORT WAVES ROTATING ABOUT THE UPPER LOW WILL BRING REINFORCING
SHOTS OF COLDER AIR TO THE REGION AS CLIPPER SYSTEMS MOVE THROUGH.
THIS WILL KEEP CLOUDS AND THE THREAT OF SNOW SHOWERS IN THE
FORECAST. THE SYSTEMS WILL HAVE LIMITED MOISTURE ASSOCIATED WITH
THEM SO ANY PRECIPITATION/SNOW SHOULD BE LIGHT.
HIGHS AND LOWS MONDAY THROUGH WEDNESDAY WILL BE SIMILAR EACH DAY AND
NIGHT RUNNING AROUND 5 TO 10 DEGREES BELOW NORMAL. THE DIFFERENCE
WILL BE THE WINDS AND HOW COLD IT FEELS. WIND CHILL COULD BE AN
ISSUE AGAIN MONDAY NIGHT INTO TUESDAY MORNING ACROSS THE SOUTHERN
ADIRONDACKS...HAVE MENTION IN OUR HAZARDOUS WEATHER OUTLOOK.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
LOW STRATUS CLOUDS FINALLY BROKE UP AT KGFL. VFR CONDITIONS ARE NOW
EXPECTED THROUGH 12Z/FRIDAY. ARCTIC COLD FRONT MOVING INTO NEW YORK
STATE...ON THE DOOR STEP TO THE FORECAST AREA. BOUNDARY WILL MOVE
ACROSS THE AREA TODAY. SOUTH TO SOUTHWEST WINDS WILL SHIFT TO THE
WEST WITH THE FRONTAL PASSAGE AND INCREASE IN SPEED WITH GUSTY
CONDITIONS AT KALB AND KPSF. WINDS WILL SHIFT MORE TO THE NORTHWEST
AND NORTH THIS EVENING AND WEAKEN.
OUTLOOK...
FRI-SAT...VFR...NO SIG WX.
SUN...MAINLY VFR. CHC -SHSN.
MON...VFR. SLIGHT CHC -SHSN.
&&
.HYDROLOGY...
MAINLY DRY AND COLD WEATHER WILL OCCUR OVER THE NEXT FIVE DAYS.
WHILE SOME SNOW SHOWERS ARE POSSIBLE OVER THE NEXT FEW DAYS ACROSS
NORTHERN AREAS...PRECIPITATION AMOUNTS WILL BE LIGHT AND IN THE
FORM OF SNOW. COLD TEMPERATURES...ESPECIALLY EARLY NEXT
WEEK...WILL CAUSE RIVER AND LAKE ICE TO FORM AND THICKEN.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...FRUGIS/HWJIV
NEAR TERM...FRUGIS/HWJIV
SHORT TERM...FRUGIS
LONG TERM...IAA
AVIATION...IAA
HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS ALBANY NY
638 AM EST THU JAN 17 2013
.SYNOPSIS...
AN ARCTIC COLD FRONT WILL CROSS THE REGION TODAY. THIS
FRONT WILL BRING SOME SNOW SHOWERS TO THE ADIRONDACKS FOR THIS
MORNING AS WELL AS ALLOWING MUCH COLDER AND BLUSTERY WEATHER INTO
THE REGION FOR TONIGHT AND TOMORROW. A WARM FRONT WILL ALLOW
TEMPERATURES TO RETURN ABOVE NORMAL AGAIN BRIEFLY FOR SATURDAY
BEFORE ANOTHER STRONG COLD FRONT RETURNS COLD WEATHER TO THE AREA
FOR SUNDAY INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 638 AM EST...SATELLITE AND SURFACE OBS SHOW AN ARCTIC COLD
FRONT CROSSING NORTHERN AND WESTERN NEW YORK. AHEAD OF THIS
BOUNDARY...THE COMBINATION OF SOME LAKE MOISTURE...LARGE SCALE
LIFT FROM THE COLD FRONT AND UPSLOPE FLOW IS ALLOWING FOR SOME
SNOW SHOWERS ACROSS THE WESTERN ADIRONDACKS...MAINLY ACROSS
NORTHERN HERKIMER COUNTY. LIGHT SNOW ACCUMULATION OF AN INCH OR
LESS IS POSSIBLE ACROSS THE WESTERN ADIRONDACKS. THE BOUNDARY
SHOULD CROSS THE ADIRONDACK REGION BY THE MID MORNING HOURS. AS
THIS BOUNDARY CONTINUES TO MOVE ACROSS THE REGION...SNOW SHOWERS
WILL BECOME MORE ISOLD. 00Z NAM12 GUIDANCE...AS WELL AS THE LOCAL
HIRES WRF AND THE 3KM HRRR GUIDANCE ALL SHOW THIS BAND OF SNOW
SHOWERS FALLING APART AS IT REACHES THE MOHAWK VALLEY/SARATOGA
AREA/SRN VT/CAPITAL REGION AROUND NOON DUE TO LITTLE MOISTURE
AVAILABLE...SO WILL ONLY GO WITH SLIGHT CHC POPS OUTSIDE THE
ADIRONDACKS. WHILE THERE MAY BE A FEW FLURRIES FOR THESE VALLEY
AREAS LATE THIS MORNING/EARLY THIS AFTN...NO SNOW ACCUMULATION IS
ANTICIPATED. THE FRONT WILL THEN CONTINUE SOUTHEAST ACROSS THE
CATSKILLS/MID HUDSON VALLEY/BERKSHIRES/NW CT FOR THIS AFTN...BUT
WITH NO PRECIP ASSOCIATED WITH IT.
THE MAIN IMPACT WITH THIS FRONT WILL BE THE SHARP TEMPERATURE
GRADIENT. MAX TEMPS WILL OCCUR AHEAD OF THE FRONT...WITH TEMPS
RANGING FROM NEAR 20 IN THE ADIRONDACKS TO NEAR 40 IN THE MID
HUDSON VALLEY. ONCE THE FRONT MOVES THROUGH...TEMPS WILL RAPIDLY
FALL...ALONG WITH GUSTY W-NW WINDS. SOME WIND GUSTS...ESP IN AREAS
OF CHANNELED FLOW SUCH AS THE MOHAWK VALLEY/CAPITAL REGION...COULD
REACH UP TO 25 MPH. THIS WILL MAKE FOR A COLD AND BLUSTERY
AFTERNOON...ESP FROM THE CAPITAL REGION ON NORTH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
IN THE WAKE OF THE FRONT...850 HPA TEMPS PLUNGE TO -16 TO -21
DEGREES C ACROSS THE REGION. THIS WILL RESULT IN VERY COLD
TEMPERATURES TONIGHT. AS WINDS BECOME LIGHT...THE EXISTING SNOW
PACK WILL AID IN ALLOWING FOR COLD MIN TEMPS...WITH SINGLE DIGITS
TO TEENS FOR AREAS FROM THE MOHAWK VALLEY/CAPITAL REGION
SOUTHWARD. NORTHERN AREAS LOOK TO BE VERY COLD...WITH READINGS
BELOW ZERO ACROSS THE ADIRONDACKS/LAKE GEORGE/GLENS FALLS AREA AND
GREEN MTNS OF SRN VT. SOME PORTIONS OF THE CENTRAL ADKS MAY DROP
-10 TO -20 DEGREES F. WIND SPEEDS SHOULD DROP TO 5 MPH OR LESS
DURING THE COLDEST PERIODS ACROSS THE ADIRONDACKS SO NO WIND CHILL
ADVISORIES WILL BE ISSUED. HOWEVER...THESE COLD AMBIENT TEMPS WILL
STILL BE HAZARDOUS ENOUGH TO CAUSE FROSTBITE QUICKLY...SO BE SURE
TO TAKE EXTREME CAUTION IF YOU PLAN ON BEING IN THE BACK COUNTRY
DURING THE OVERNIGHT HOURS. DESPITE THE COLD TEMPS...IT WON/T BE
COMPLETELY CLEAR TONIGHT DUE TO THE UPPER TROUGH PASSING OVERHEAD
AND SOME PASSING CLOUDS WILL BE AROUND. HOWEVER...NO SNOW SHOWERS
ARE EXPECTED...ALTHOUGH SOME ICE CRYSTALS /DIAMOND DUST/ ARE
POSSIBLE ACROSS THE ADIRONDACKS DUE TO THE COLD TEMPS.
ON FRIDAY...A FEW LAKE EFFECT FLURRIES ARE POSSIBLE FOR FAR
WESTERN AREAS...BUT THE SHEAR ISN/T FAVORABLE FOR MUCH LAKE EFFECT
TO OCCUR. LITTLE TO NO SNOW ACCUMULATION IS EXPECTED FOR OUR
AREA. OTHERWISE...IT LOOKS TO REMAIN DRY WITH PARTLY TO MOSTLY
SUNNY SKIES. WARM AIR ADVECTION WILL BEGIN TO TAKE PLACE BY LATE
IN THE DAY AS A WARM FRONT STARTS TO MOVE NORTH FROM THE SOUTH.
MAX TEMPS ON FRIDAY WILL BE COLD WITH TEENS AND 20S ACROSS THE
AREA.
SOUTHERLY WINDS...AND WARMING TEMPS ALOFT...WILL ALLOW FOR FRI
NIGHT TO NOT BE AS COLD AS TONIGHT. IT WILL ONLY DROP A FEW
DEGREES FROM FRIDAY/S HIGHS ACROSS THE AREA...AND TEMPS MAY EVEN
HOLD STEADY OR RISE AT TIMES.
BY SATURDAY...THE REGION WILL BE BACK IN A WARM SECTOR...AND
ABOVE NORMAL TEMPS WILL RETURN...WITH 30S TO LOW 40S ACROSS THE
REGION. A CLIPPER SYSTEM WILL PASS ACROSS SOUTHERN CANADA...AND IT
MAY BE CLOSE ENOUGH TO BRING SOME LIGHT SNOW TO THE
ADIRONDACKS...ALTHOUGH THE BEST ACTIVITY LOOKS TO STAY NORTH OF
THE US/CANADIAN BORDER. OTHERWISE...SKIES WILL BE PARTLY TO MOSTLY
CLOUDY.
ANOTHER ARCTIC FRONT WILL START TO APPROACH THE AREA FOR SATURDAY
NIGHT. THE REGION SHOULD REMAIN OUT AHEAD OF IT THROUGH THE
OVERNIGHT HOURS...SO TEMPS SAT NIGHT WON/T BE COLD YET /MAINLY
20S/. SOME SNOW SHOWERS MAY AFFECT MAINLY WESTERN PARTS OF THE
REGION...ESP FOR THE LATE NIGHT HOURS.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
...LOOKING AT A PERIOD OF BELOW NORMAL TEMPERATURES...
NORMAL TEMPERATURES FOR THE PERIOD JAN 20TH THROUGH 23RD:
ALBANY: HIGHS AROUND 30. LOWS IN THE MID TEENS.
GLENS FALLS: HIGHS IN THE UPPER 20S. LOWS IN THE SINGLE DIGITS.
POUGHKEEPSIE: HIGHS IN THE MID 30S. LOWS IN THE MID TEENS.
BENNINGTON: HIGHS AROUND 30. LOWS NEAR 10.
PITTSFIELD: HIGHS IN THE UPPER 20S. LOWS NEAR 10.
MODEL GUIDANCE IS IN AGREEMENT IN REGARDS TO THE LONGWAVE PATTERN
FOR THE PERIOD WITH A LARGE TROUGH COVERING THE EASTERN 2/3 OF THE
CONUS WITH SHORT WAVES ROTATING ABOUT AN UPPER LOW OVER HUDSONS BAY
CANADA AND RIDGING ALONG THE WEST COAST. THE DIFFERENCES IN THE
MODELS ARE WITH THE TIMING OF THE SHORT WAVES AND ASSOCIATED FRONTAL
BOUNDARIES CROSSING THE REGION.
AN ARCTIC FRONT WILL CROSS THE REGION SUNDAY. THIS FRONT WILL HAVE
SOME DECENT UPPER LEVEL DYNAMICS AND A SHARP THERMAL GRADIENT
ASSOCIATED WITH IT...SO A ROUND OF SNOW SHOWERS/SQUALLS IS POSSIBLE
WITH THE FRONTAL PASSAGE. WINDS WILL SHIFT WEST-NORTHWEST AND BECOME
BRISK AND GUSTY IN ITS WAKE AND TEMPERATURES SHOULD DROP DURING THE
AFTERNOON.
IT WILL GET COLD SUNDAY NIGHT WITH 850 MB TEMPERATURES DROPPING TO
-15 TO -20 C ACROSS THE FORECAST AREA. WESTERLY WINDS OF 10 TO 20
MPH WILL MAKE IT FEEL EVEN COLDER. WIND CHILL VALUES MAY REACH
ADVISORY CRITERIA (-20F) ACROSS THE SOUTHERN ADIRONDACKS...HAVE
MENTION IN OUR HAZARDOUS WEATHER OUTLOOK.
SHORT WAVES ROTATING ABOUT THE UPPER LOW WILL BRING REINFORCING
SHOTS OF COLDER AIR TO THE REGION AS CLIPPER SYSTEMS MOVE THROUGH.
THIS WILL KEEP CLOUDS AND THE THREAT OF SNOW SHOWERS IN THE
FORECAST. THE SYSTEMS WILL HAVE LIMITED MOISTURE ASSOCIATED WITH
THEM SO ANY PRECIPITATION/SNOW SHOULD BE LIGHT.
HIGHS AND LOWS MONDAY THROUGH WEDNESDAY WILL BE SIMILAR EACH DAY AND
NIGHT RUNNING AROUND 5 TO 10 DEGREES BELOW NORMAL. THE DIFFERENCE
WILL BE THE WINDS AND HOW COLD IT FEELS. WIND CHILL COULD BE AN
ISSUE AGAIN MONDAY NIGHT INTO TUESDAY MORNING ACROSS THE SOUTHERN
ADIRONDACKS...HAVE MENTION IN OUR HAZARDOUS WEATHER OUTLOOK.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
LOW STRATUS CLOUDS FINALLY BROKE UP AT KGFL. VFR CONDITIONS ARE NOW
EXPECTED THROUGH 12Z/FRIDAY. ARCTIC COLD FRONT MOVING INTO NEW YORK
STATE...ON THE DOOR STEP TO THE FORECAST AREA. BOUNDARY WILL MOVE
ACROSS THE AREA TODAY. SOUTH TO SOUTHWEST WINDS WILL SHIFT TO THE
WEST WITH THE FRONTAL PASSAGE AND INCREASE IN SPEED WITH GUSTY
CONDITIONS AT KALB AND KPSF. WINDS WILL SHIFT MORE TO THE NORTHWEST
AND NORTH THIS EVENING AND WEAKEN.
OUTLOOK...
FRI-SAT...VFR...NO SIG WX.
SUN...MAINLY VFR. CHC -SHSN.
MON...VFR. SLIGHT CHC -SHSN.
&&
.HYDROLOGY...
MAINLY DRY AND COLD WEATHER WILL OCCUR OVER THE NEXT FIVE DAYS.
WHILE SOME SNOW SHOWERS ARE POSSIBLE OVER THE NEXT FEW DAYS ACROSS
NORTHERN AREAS...PRECIPITATION AMOUNTS WILL BE LIGHT AND IN THE
FORM OF SNOW. COLD TEMPERATURES...ESPECIALLY EARLY NEXT
WEEK...WILL CAUSE RIVER AND LAKE ICE TO FORM AND THICKEN.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...FRUGIS
NEAR TERM...FRUGIS
SHORT TERM...FRUGIS
LONG TERM...IAA
AVIATION...IAA
HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
905 PM CST FRI JAN 18 2013
.DISCUSSION...
240 PM CST
A VERY ACTIVE WEATHER PATTERN WILL PERSIST FOR THE NEXT SEVERAL
DAYS. WHILE THE WEATHER PATTERN WILL BE A BIT OF A ROLLER COASTER
RIDE...THE MAIN ISSUES WILL FOCUS ON TEMPERATURES...WITH
STILL...LITTLE OPPORTUNITY FOR ANY SIGNIFICANT PRECIPITATION.
FOR THE REMAINDER OF THE AFTERNOON AND THIS EVENING...THE MAIN
FORECAST CONCERN WILL FOCUS ON THE ONGOING STRONG WINDS. LATEST
TAMDAR SOUNDINGS INDICATE WINDS UP TO 50KT AT THE TOP OF THE MIXED
LAYER...BUT THESE STRONGEST WINDS HAVE NOT BEEN ABLE TO MIX DOWN TO
THE SURFACE. THE LATEST SFC OBS ACROSS THE REGION INDICATE
WIDESPREAD GUSTS OF 30-35KT ACROSS THE AREA. WITH THE SUN ANGLE
BEGINNING TO DECREASE THROUGH THE AFTERNOON AND NO ADDITIONAL SFC
WARMING LIKELY...DO NOT EXPECT THAT WINDS WILL GET ANY HIGHER THAN
CURRENTLY OCCURRING...AND SHOULD BEGIN TO DROP OFF AT SUNSET.
ALSO...WITH THE FIRST IN A SERIES OF SFC LOW TRACKING THROUGH NRN WI
AND NRN LAKE MICHIGAN...COMBINED WITH STRONG HIGH PRESSURE OVER THE
MID ATLANTIC REGION...A STRONG SWLY PRESSURE GRADIENT WILL REMAIN IN
PLACE THROUGH THE NIGHT. THIS WILL HAVE A TWO-FOLD IMPACT.
FIRST...WINDS WILL REMAIN RATHER BREEZY THROUGH THE NIGHT AND THE
PERSISTENT WARM ADVECTION WILL ALLOW MAX TEMPS TO PEAK IN THE
LOWER...TO PERHAPS MIDDLE...40S. SECOND...OVERNIGHT LOWS TONIGHT
WILL NOT BE QUITE AS LOW AS RECENT DAYS...WITH TEMPS BOTTOMING OUT
IN THE LOWER TO MIDDLE 30S.
SATURDAY SHOULD REMAIN ON THE WARMER SIDE AS A SECOND LOW DROPS OUT
OF THE CANADIAN ROCKIES TONIGHT AND TAKES A SIMILAR TRACK ACROSS THE
NORTHERN PLAINS AND UPPER MISSISSIPPI VALLEY TOMORROW MORNING AND
THE NORTHERN GREAT LAKES TOMORROW AFTERNOON. CONDITIONS WILL BE
BREEZY AND UNSEASONABLY WARM AGAIN ON SATURDAY...BUT DO NOT EXPECT
WINDS TO BE QUITE AS STRONG AS THE TRACK OF THE LOW WILL BE A LITTLE
FARTHER NORTH...ACROSS THE UPPER PENINSULA OF MICHIGAN WHILE THE
CENTER OF THE HIGH SAGS SWD INTO THE CAROLINAS. A SIGNIFICANT
CHANGE IN AIR MASS CHARACTER WILL COMMENCE AS THE LOW DRAGS AN ARCTIC
COLD FRONT ACROSS THE REGION...USHERING IN MUCH COOLER AIR WITH AN
EXTENDED PERIOD OF COLD ADVECTION...WHICH WILL PERSIST INTO EARLY
NEXT WEEK.
THE TEMPERATURE DROP OFF WILL QUITE DRAMATIC WITH HIGHS ON SUNDAY
EXPECTED TO BE AROUND 25 DEGREES LOWER THAN SATURDAY...RANGING FROM
THE UPPER TEENS ALONG THE WISCONSIN BORDER TO THE MIDDLE 20S SOUTH
OF THE KANKAKEE/ILLINOIS RIVERS. THE TRUE ARCTIC AIR MASS WILL
ARRIVE OVERNIGHT SUNDAY NIGH AND MONDAY AS STRONG HIGH PRESSURE
BUILDS DOWN OUT OF CANADA...SPREADING ACROSS THE NRN PLAINS AND THE
MISSISSIPPI VALLEY. BY MONDAY MORNING...EXPECT LOW TEMPERATURES
SHOULD BE IN THE SINGLE DIGITS RIGHT UP THE LAKE MICHIGAN SHORELINE
AND EVEN DOWNTOWN CHICAGO WILL NOT ESCAPE THE COLD AS NORTHWESTERLY
WINDS WILL NOT ALLOW ANY WARMING EFFECT OF THE ADJACENT LAKE
MICHIGAN WATERS. THE ONLY PART OF THE AREA NOT EXPECTED TO SEE
TEMPS DROP INTO THE SINGLE DIGITS WILL BE NRN PORTER COUNTY...WHERE
THE NWLY FLOW MAY ALLOW FOR SOME LAKE EFFECT CLOUD COVER. WITH THE
PERSISTENT COLD ADVECTION AND THE CENTER OF THE ARCTIC HIGH EXPECTED
TO MOVE ACROSS IL/WI...THERE WILL BE LITTLE DIURNAL TEMPERATURE
VARIATION THROUGH THE DAY ON MONDAY. EVEN WITH SOME SUNSHINE UNDER
PARTLY CLOUDY SKIES...TEMPERATURES SHOULD ONLY CLIMB A FEW DEGREES
THROUGH THE DAY...TOPPING OUT IN THE SINGLE DIGITS IN NRN
IL...INCLUDING THE ROCKFORD METRO AREA...WHILE THE REST OF THE CWA
WILL SEE HIGHS IN THE LOWER TEENS. TUESDAY MORNING WILL BE THE
COLDEST SEEN IN QUITE SOME TIME AS LIGHT WINDS AND LIMITED CLOUD
COVER WILL ALLOW FOR SIGNIFICANT RADIATIVE COOLING WITH LOWS
DROPPING TO NEAR OR SLIGHTLY BELOW 0F. QUITE A FEAT CONSIDERING THE
LAKE OF SNOW COVER. WITH THE HIGH REMAINING OVER THE REGION...HIGHS
ON TUESDAY WILL BE LITTLE DIFFERENT FROM THOSE SEEN ON MONDAY.
FOR THE EXTENDED FORECAST PERIOD...FROM WEDNESDAY INTO SATURDAY...A
RAPID WARMING TREND WILL OCCUR AS LOW LEVEL FLOW QUICKLY RETURNS TO
SOUTHERLY IN ADVANCE OF A WEAK CLIPPER-TYPE SYSTEM DROPPING ACROSS
THE NORTHERN PLAINS AND A SOUTHERN STREAM SYSTEM DEVELOPING OVER THE
CENTRAL PLAINS. GIVEN THE CONTINUED LACK OF SNOW COVER TO MODIFY
THE AIR MASS DRAWN ACROSS THE AREA IN THE SWLY FLOW AHEAD OF THE SRN
STREAM SYSTEM...EXPECT THAT TEMPERATURES SHOULD BE ABLE TO CLIMB
BACK INTO THE UPPER 30S TO LOWER 40S BY THURSDAY.
UNFORTUNATELY...SIGNIFICANT MODEL DIFFERENCES DEVELOP BY THIS TIME
RANGE BETWEEN THE GFS AND THE ECMWF. THE GFS IS ADVERTISING NO
PHASING OF THE NRN AND SRN STREAM SYSTEMS...WITH THE SRN STREAM
SYSTEM RACING OUT AHEAD OF THE CLIPPER. THE ECMWF IS SIGNIFICANTLY
DIFFERENT...PHASING THE TWO SYSTEM INTO A SINGLE LOW...TRACKING
ACROSS CENTRAL ILLINOIS THURSDAY NIGHT AND QUICKLY TRACKING INTO
SWRN PA BY FRIDAY MORNING. THE GFS FINALLY INDICATES SOME PHASING
OF THE TWO SYSTEMS...BUT NOT UNTIL THEY PUSH EAST OF THE AREA ON
FRIDAY. THESE DIFFERENT SCENARIOS SHOULD HAVE A SIGNIFICANT IMPACT
ON THE LOCAL WEATHER. THE SLOWER GFS WOULD ALLOW FOR WARMER
CONDITIONS AND A GREATER CHANCE FOR ANY ASSOCIATED PCPN TO LESS
LIKELY BE SNOW...WHILE THE FASTER ECMWF WOULD SUGGEST A COOLER
FORECAST WITH A GREATER CHANCE FOR AT LEAST SOME SNOW. GIVEN THE
FAIR AMOUNT OF UNCERTAINTY BUT WITH A HISTORY OF WARMER CONDITIONS
THIS WINTER...HAVE TRENDED CLOSER TO THE WARMER SOLUTION. WHILE
EITHER SOLUTION WOULD SUGGEST A SIGNIFICANT CHANCE FOR PRECIPITATION
FOR THURSDAY INTO FRIDAY...FEEL THAT THERE SHOULD BE A PERIOD OF
RAIN LATE THURSDAY...WITH A CHANCE FOR SOME LIGHT SNOW EARLY
THURSDAY AND THEN LATER THURSDAY NIGHT.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 03Z...
* SSW WIND GUSTING 20-25KT REST OF THIS EVENING AND INTO
OVERNIGHT.
* SW WIND GUSTING 22-27KT MID MORNING THROUGH AFTERNOON SAT.
* STRONG GOLD FRONT PASSAGE DURING EARLY EVENING SAT WITH W-WNW
WIND GUSTING 30-35KT.
TRS
//DISCUSSION...UPDATED 03Z...
SW WINDS OF 50-60KT CONTINUE TO BE SEEN IN VAD WINDS AND AIRCRAFT
REPORTS SO HAVE EXTENDED INCLUSION OF LLWS IN TAFORS THROUGH THE
NIGHT...THOUGH HAVE SPEED GRADUALLY DECREASING TO 40KT WITH TIME
PER LATEST RAP HOURLY WIND PROGS.
PREVIOUS DISCUSSION...UPDATED 00Z...
WITH SUNDOWN...A LESSENING OF THE PRESSURE GRADIENT OVER THE AREA
AND THE PRESSURE FALL CENTER MOVING E TO THE CENTRAL GREAT LAKES
WINDS HAVE DIMINISHED SOMEWHAT EARLY THIS EVENING. A SLOW
DIMINISHING OF SURFACE WIND SPEED IS EXPECTED TO CONTINUE
TONIGHT. WHILE SURFACE WINDS ARE DROPPING OFF WINDS WITHIN 2K FT
AGL ARE 45-50KT PER VAD WIND PROFILES FROM KLOT AND TORD RADARS
VERIFYING RAP MODEL WIND FORECAST. LATEST RAP RUN FROM 22Z HAS SW
WINDS JUST ABOVE THE SURFACE GRADUALLY DIMINISHING THROUGH THE
NIGHT. HAVE LLWS DROPPED FROM THE TAFORS AT 05Z THOUGH MAY NEED
TO EXTEND IT A BIT FURTHER INTO THE OVERNIGHT IF LOW LEVEL WINDS
DO NOT DROP OFF QUITE THAT QUICKLY.
PRESSURE GRADIENT WILL INCREASE AGAIN SAT AS ANOTHER LOW DEEPENS
AS IT MOVES FROM NW MN ESE TO EASTERN LAKE SUPERIOR DURING THE
DAY. SW SURFACE WIND SAT NOT EXPECTED TO BE AS STRONG AS THIS
AFTERNOON BUT ARE EXPECTED TO BE GUSTING IN THE MID TO UPPER 20KT
RANGE BY MIDDAY. A STRONG COLD FRONT TRAILING SW FROM THE LOW IS
PROGGED TO ADVANCE TO ACROSS W CENTRAL LOWER MI...FAR NE IL AND E
CENTRAL IA BY 20.00Z AND TO THEN MOVE ACROSS ORD AND MDW DURING
THE EARLY EVENING SHIFTING WINDS FROM WSW TO WNW AND GUST 30-35KT
AS A STRONG PRESSURE RISE CENTER MOVES SE TOWARD THE LOCAL AREA
AS ARCTIC AIR SPILLS FURTHER SOUTHEASTWARD FROM THE UPPER
MIDWEST.
TRS
//ORD AND MDW CONFIDENCE...UPDATED 03Z...
* HIGH CONFIDENCE ALL ELEMENTS...EXCEPT MODERATE CONFIDENCE IN
WIND SPEED FROM SAT MID-MORNING THROUGH AFTERNOON.
TRS
//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...
SUNDAY...MVFR CEILINGS.
MONDAY...VFR.
TUESDAY...VFR.
WEDNESDAY...VFR.
THURSDAY...VFR. CHANCE OF SN RESULTING IN MVFR CONDITIONS.
TRS
&&
.MARINE...
237 PM CST
HIGH PRESSURE REMAINS FROM THE LOWER MISSISSIPPI RIVER VALLEY
NORTHEASTWARD ACROSS THE OHIO VALLEY AND MID ATLANTIC THIS AFTERNOON
WHILE AND ELONGATED AREA OF LOW PRESSURE IS SPREAD FROM CENTRAL
ALBERTA TO LAKE MICHIGAN. A LOW PRESSURE CIRCULATION EMBEDDED WITHIN
THE TROUGH IS PUSHING FROM WESTERN WISCONSIN EASTWARD WITH VERY
STRONG PRESSURE FALLS OVER LAKE MICHIGAN THANKS TO THE DIFFERENCE IN
PRESSURE BETWEEN IT AND THE HIGH TO THE SOUTHEAST. SOUTHWEST GALES
CONTINUE ACROSS THE SOUTHERN TWO-THIRDS OR SO OF THE LAKE WITH THE
FAR NORTH IN THE TROUGH AXIS RESULTING IN LIGHTER WINDS. THE LOW
WILL CROSS THE LAKE THIS EVENING ALLOWING WINDS TO EASE FROM
NORTHWEST TO SOUTHEAST THROUGH THE EVENING. NORTH-CENTRAL SECTIONS
OF THE LAKE SHOULD SEE WINDS EASE THIS EVENING WITH IT TAKING UNTIL
AROUND MIDNIGHT OR SOON AFTER FOR GALES TO DIMINISH SOUTH. WILL
LET THE GALE WARNING GO AS-IS FOR NOW BUT IT MAY BE ABLE TO BE
CANCELLED EARLY NORTH. FOR THE NEARSHORE WATERS...WILL END THE
ILLINOIS SHORES A BIT EARLIER BUT CARRY THE INDIANA SHORELINE
UNTIL 09Z AS SCHEDULED BUT IT IS POSSIBLE THIS MAY NEED TO BE
SHORTENED. EXPECT THAT A SMALL CRAFT ADVISORY WILL BE NEEDED ONCE
GALES DIMINISH.
A SECOND LOW WILL DEEPEN ACROSS SASKATCHEWAN TONIGHT AND MOVE TO
WESTERN LAKE SUPERIOR BY SATURDAY AFTERNOON. THE LOW WILL THEN
FURTHER DEEPEN AS IT CROSSES THE U.P. OF MICHIGAN SATURDAY EVENING
AND HEADS TOWARD SOUTHERN QUEBEC BY SUNDAY MORNING. SOUTH TO
SOUTHWEST WINDS WILL INTENSIFY SATURDAY WITH LOWER END GALES
EXPECTED TO BEGIN DURING THE EARLY AFTERNOON ACROSS THE OPEN
WATERS...WITH NEARSHORE AREAS LIKELY HOLDING INTO THE UPPER 20S TO
ABOUT 30 KT. WILL PUSH THE START TIME OF THE GALE WATCH FOR THE
NEARSHORE WATERS LATER TO 00Z BUT UPGRADE TO A GALE WARNING FOR THE
OPEN WATERS FROM 18Z ON WITH THE NORTHERN TWO-THIRDS EXPECTED TO SEE
GALES DURING THE AFTERNOON. WINDS WILL TURN WESTERLY THEN
NORTHWESTERLY SATURDAY EVENING AS THE LOW AND A COLD FRONT PASS WITH
MUCH COLDER AIR ARRIVING. THE COMBINATION OF COLD ADVECTION AND THE
DEEPENING LOW PASSING NORTH OF THE LAKE WILL BE VERY FAVORABLE FOR
HIGH END GALES ACROSS MUCH OF THE LAKE SATURDAY EVENING AND EARLY
SATURDAY NIGHT BEFORE EASING SUNDAY MORNING. IT DOES APPEAR THAT A
3-6 HR PERIOD WILL BE FAVORABLE FOR A FEW STORM FORCE GUSTS TO 50 KT
ROUGHLY BETWEEN 03 AND 06 OR 09Z ACROSS CENTRAL PORTIONS OF THE
LAKE. WILL HIGHLIGHT THIS IN THE TEXT FOR NOW. WITH THE COLDER
AIR...HEAVY FREEZING SPRAY IS ALSO A CONCERN LATE SATURDAY EVENING
THROUGH SUNDAY MORNING AS AIR TEMPS FALL INTO THE MID/UPPER TEENS.
WILL ISSUE A HEAVY FREEZING SPRAY WATCH FROM 06 TO 18Z SUNDAY.
WINDS WILL EASE SUNDAY MORNING AS THE LOW DEPARTS BUT THE STEADY
FLOW OF COLDER AIR AND A TIGHT PRESSURE GRADIENT WILL KEEP WINDS
ELEVATED THROUGH EARLY NEXT WEEK AND MAY BE MODULATED UP AND DOWN
BY PASSING WEAK LOWS. HIGH PRESSURE DOES LOOK TO EVENTUALLY ARRIVE
OVER THE LAKE DURING THE MID OR LATE PART OF THE WEEK WHICH WOULD
PROVIDE MUCH LIGHTER WINDS.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ366-LMZ565-LMZ567-LMZ669-LMZ671-LMZ673-
LMZ675-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ868-LMZ870-
LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 3 AM SATURDAY.
GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...NOON SATURDAY TO 9 AM
SUNDAY.
HEAVY FREEZING SPRAY WATCH...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-
LMZ563-LMZ565-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-
LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...MIDNIGHT SUNDAY TO
NOON SUNDAY.
GALE WATCH...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745...6 PM
SATURDAY TO 9 AM SUNDAY.
GALE WARNING...ILLINOIS NEARSHORE WATERS UNTIL 10 PM FRIDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
611 PM CST FRI JAN 18 2013
.DISCUSSION...
240 PM CST
A VERY ACTIVE WEATHER PATTERN WILL PERSIST FOR THE NEXT SEVERAL
DAYS. WHILE THE WEATHER PATTERN WILL BE A BIT OF A ROLLER COASTER
RIDE...THE MAIN ISSUES WILL FOCUS ON TEMPERATURES...WITH
STILL...LITTLE OPPORTUNITY FOR ANY SIGNIFICANT PRECIPITATION.
FOR THE REMAINDER OF THE AFTERNOON AND THIS EVENING...THE MAIN
FORECAST CONCERN WILL FOCUS ON THE ONGOING STRONG WINDS. LATEST
TAMDAR SOUNDINGS INDICATE WINDS UP TO 50KT AT THE TOP OF THE MIXED
LAYER...BUT THESE STRONGEST WINDS HAVE NOT BEEN ABLE TO MIX DOWN TO
THE SURFACE. THE LATEST SFC OBS ACROSS THE REGION INDICATE
WIDESPREAD GUSTS OF 30-35KT ACROSS THE AREA. WITH THE SUN ANGLE
BEGINNING TO DECREASE THROUGH THE AFTERNOON AND NO ADDITIONAL SFC
WARMING LIKELY...DO NOT EXPECT THAT WINDS WILL GET ANY HIGHER THAN
CURRENTLY OCCURRING...AND SHOULD BEGIN TO DROP OFF AT SUNSET.
ALSO...WITH THE FIRST IN A SERIES OF SFC LOW TRACKING THROUGH NRN WI
AND NRN LAKE MICHIGAN...COMBINED WITH STRONG HIGH PRESSURE OVER THE
MID ATLANTIC REGION...A STRONG SWLY PRESSURE GRADIENT WILL REMAIN IN
PLACE THROUGH THE NIGHT. THIS WILL HAVE A TWO-FOLD IMPACT.
FIRST...WINDS WILL REMAIN RATHER BREEZY THROUGH THE NIGHT AND THE
PERSISTENT WARM ADVECTION WILL ALLOW MAX TEMPS TO PEAK IN THE
LOWER...TO PERHAPS MIDDLE...40S. SECOND...OVERNIGHT LOWS TONIGHT
WILL NOT BE QUITE AS LOW AS RECENT DAYS...WITH TEMPS BOTTOMING OUT
IN THE LOWER TO MIDDLE 30S.
SATURDAY SHOULD REMAIN ON THE WARMER SIDE AS A SECOND LOW DROPS OUT
OF THE CANADIAN ROCKIES TONIGHT AND TAKES A SIMILAR TRACK ACROSS THE
NORTHERN PLAINS AND UPPER MISSISSIPPI VALLEY TOMORROW MORNING AND
THE NORTHERN GREAT LAKES TOMORROW AFTERNOON. CONDITIONS WILL BE
BREEZY AND UNSEASONABLY WARM AGAIN ON SATURDAY...BUT DO NOT EXPECT
WINDS TO BE QUITE AS STRONG AS THE TRACK OF THE LOW WILL BE A LITTLE
FARTHER NORTH...ACROSS THE UPPER PENINSULA OF MICHIGAN WHILE THE
CENTER OF THE HIGH SAGS SWD INTO THE CAROLINAS. A SIGNIFICANT
CHANGE IN AIR MASS CHARACTER WILL COMMENCE AS THE LOW DRAGS AN ARCTIC
COLD FRONT ACROSS THE REGION...USHERING IN MUCH COOLER AIR WITH AN
EXTENDED PERIOD OF COLD ADVECTION...WHICH WILL PERSIST INTO EARLY
NEXT WEEK.
THE TEMPERATURE DROP OFF WILL QUITE DRAMATIC WITH HIGHS ON SUNDAY
EXPECTED TO BE AROUND 25 DEGREES LOWER THAN SATURDAY...RANGING FROM
THE UPPER TEENS ALONG THE WISCONSIN BORDER TO THE MIDDLE 20S SOUTH
OF THE KANKAKEE/ILLINOIS RIVERS. THE TRUE ARCTIC AIR MASS WILL
ARRIVE OVERNIGHT SUNDAY NIGH AND MONDAY AS STRONG HIGH PRESSURE
BUILDS DOWN OUT OF CANADA...SPREADING ACROSS THE NRN PLAINS AND THE
MISSISSIPPI VALLEY. BY MONDAY MORNING...EXPECT LOW TEMPERATURES
SHOULD BE IN THE SINGLE DIGITS RIGHT UP THE LAKE MICHIGAN SHORELINE
AND EVEN DOWNTOWN CHICAGO WILL NOT ESCAPE THE COLD AS NORTHWESTERLY
WINDS WILL NOT ALLOW ANY WARMING EFFECT OF THE ADJACENT LAKE
MICHIGAN WATERS. THE ONLY PART OF THE AREA NOT EXPECTED TO SEE
TEMPS DROP INTO THE SINGLE DIGITS WILL BE NRN PORTER COUNTY...WHERE
THE NWLY FLOW MAY ALLOW FOR SOME LAKE EFFECT CLOUD COVER. WITH THE
PERSISTENT COLD ADVECTION AND THE CENTER OF THE ARCTIC HIGH EXPECTED
TO MOVE ACROSS IL/WI...THERE WILL BE LITTLE DIURNAL TEMPERATURE
VARIATION THROUGH THE DAY ON MONDAY. EVEN WITH SOME SUNSHINE UNDER
PARTLY CLOUDY SKIES...TEMPERATURES SHOULD ONLY CLIMB A FEW DEGREES
THROUGH THE DAY...TOPPING OUT IN THE SINGLE DIGITS IN NRN
IL...INCLUDING THE ROCKFORD METRO AREA...WHILE THE REST OF THE CWA
WILL SEE HIGHS IN THE LOWER TEENS. TUESDAY MORNING WILL BE THE
COLDEST SEEN IN QUITE SOME TIME AS LIGHT WINDS AND LIMITED CLOUD
COVER WILL ALLOW FOR SIGNIFICANT RADIATIVE COOLING WITH LOWS
DROPPING TO NEAR OR SLIGHTLY BELOW 0F. QUITE A FEAT CONSIDERING THE
LAKE OF SNOW COVER. WITH THE HIGH REMAINING OVER THE REGION...HIGHS
ON TUESDAY WILL BE LITTLE DIFFERENT FROM THOSE SEEN ON MONDAY.
FOR THE EXTENDED FORECAST PERIOD...FROM WEDNESDAY INTO SATURDAY...A
RAPID WARMING TREND WILL OCCUR AS LOW LEVEL FLOW QUICKLY RETURNS TO
SOUTHERLY IN ADVANCE OF A WEAK CLIPPER-TYPE SYSTEM DROPPING ACROSS
THE NORTHERN PLAINS AND A SOUTHERN STREAM SYSTEM DEVELOPING OVER THE
CENTRAL PLAINS. GIVEN THE CONTINUED LACK OF SNOW COVER TO MODIFY
THE AIR MASS DRAWN ACROSS THE AREA IN THE SWLY FLOW AHEAD OF THE SRN
STREAM SYSTEM...EXPECT THAT TEMPERATURES SHOULD BE ABLE TO CLIMB
BACK INTO THE UPPER 30S TO LOWER 40S BY THURSDAY.
UNFORTUNATELY...SIGNIFICANT MODEL DIFFERENCES DEVELOP BY THIS TIME
RANGE BETWEEN THE GFS AND THE ECMWF. THE GFS IS ADVERTISING NO
PHASING OF THE NRN AND SRN STREAM SYSTEMS...WITH THE SRN STREAM
SYSTEM RACING OUT AHEAD OF THE CLIPPER. THE ECMWF IS SIGNIFICANTLY
DIFFERENT...PHASING THE TWO SYSTEM INTO A SINGLE LOW...TRACKING
ACROSS CENTRAL ILLINOIS THURSDAY NIGHT AND QUICKLY TRACKING INTO
SWRN PA BY FRIDAY MORNING. THE GFS FINALLY INDICATES SOME PHASING
OF THE TWO SYSTEMS...BUT NOT UNTIL THEY PUSH EAST OF THE AREA ON
FRIDAY. THESE DIFFERENT SCENARIOS SHOULD HAVE A SIGNIFICANT IMPACT
ON THE LOCAL WEATHER. THE SLOWER GFS WOULD ALLOW FOR WARMER
CONDITIONS AND A GREATER CHANCE FOR ANY ASSOCIATED PCPN TO LESS
LIKELY BE SNOW...WHILE THE FASTER ECMWF WOULD SUGGEST A COOLER
FORECAST WITH A GREATER CHANCE FOR AT LEAST SOME SNOW. GIVEN THE
FAIR AMOUNT OF UNCERTAINTY BUT WITH A HISTORY OF WARMER CONDITIONS
THIS WINTER...HAVE TRENDED CLOSER TO THE WARMER SOLUTION. WHILE
EITHER SOLUTION WOULD SUGGEST A SIGNIFICANT CHANCE FOR PRECIPITATION
FOR THURSDAY INTO FRIDAY...FEEL THAT THERE SHOULD BE A PERIOD OF
RAIN LATE THURSDAY...WITH A CHANCE FOR SOME LIGHT SNOW EARLY
THURSDAY AND THEN LATER THURSDAY NIGHT.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* SSW WIND GUSTING 20-25KT THROUGH THE THIS EVENING AND INTO
OVERNIGHT.
* SW WIND GUSTING 22-27KT MID MORNING THROUGH AFTERNOON SAT.
* STRONG GOLD FRONT PASSAGE DURING EARLY EVENING SAT WITH W-WNW
WIND GUSTING 30-35KT.
TRS
//DISCUSSION...UPDATED 00Z...
WITH SUNDOWN...A LESSENING OF THE PRESSURE GRADIENT OVER THE AREA
AND THE PRESSURE FALL CENTER MOVING E TO THE CENTRAL GREAT LAKES
WINDS HAVE DIMINISHED SOMEWHAT EARLY THIS EVENING. A SLOW
DIMINISHING OF SURFACE WIND SPEED IS EXPECTED TO CONTINUE
TONIGHT. WHILE SURFACE WINDS ARE DROPPING OFF WINDS WITHIN 2K FT
AGL ARE 45-50KT PER VAD WIND PROFILES FROM KLOT AND TORD RADARS
VERIFYING RAP MODEL WIND FORECAST. LATEST RAP RUN FROM 22Z HAS SW
WINDS JUST ABOVE THE SURFACE GRADUALLY DIMINISHING THROUGH THE
NIGHT. HAVE LLWS DROPPED FROM THE TAFORS AT 05Z THOUGH MAY NEED
TO EXTEND IT A BIT FURTHER INTO THE OVERNIGHT IF LOW LEVEL WINDS
DO NOT DROP OFF QUITE THAT QUICKLY.
PRESSURE GRADIENT WILL INCREASE AGAIN SAT AS ANOTHER LOW DEEPENS
AS IT MOVES FROM NW MN ESE TO EASTERN LAKE SUPERIOR DURING THE
DAY. SW SURFACE WIND SAT NOT EXPECTED TO BE AS STRONG AS THIS
AFTERNOON BUT ARE EXPECTED TO BE GUSTING IN THE MID TO UPPER 20KT
RANGE BY MIDDAY. A STRONG COLD FRONT TRAILING SW FROM THE LOW IS
PROGGED TO ADVANCE TO ACROSS W CENTRAL LOWER MI...FAR NE IL AND E
CENTRAL IA BY 20.00Z AND TO THEN MOVE ACROSS ORD AND MDW DURING
THE EARLY EVENING SHIFTING WINDS FROM WSW TO WNW AND GUST 30-35KT
AS A STRONG PRESSURE RISE CENTER MOVES SE TOWARD THE LOCAL AREA
AS ARCTIC AIR SPILLS FURTHER SOUTHEASTWARD FROM THE UPPER
MIDWEST.
TRS
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* HIGH CONFIDENCE ALL ELEMENTS...EXCEPT MODERATE CONFIDENCE IN
WIND SPEED FROM SAT MID-MORNING THROUGH AFTERNOON.
TRS
//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...
SUNDAY...MVFR CEILINGS.
MONDAY...VFR CEILINGS.
TUESDAY...VFR.
WEDNESDAY...VFR.
THURSDAY...VFR. CHANCE OF SN RESULTING IN MVFR CONDITIONS.
TRS
&&
.MARINE...
237 PM CST
HIGH PRESSURE REMAINS FROM THE LOWER MISSISSIPPI RIVER VALLEY
NORTHEASTWARD ACROSS THE OHIO VALLEY AND MID ATLANTIC THIS AFTERNOON
WHILE AND ELONGATED AREA OF LOW PRESSURE IS SPREAD FROM CENTRAL
ALBERTA TO LAKE MICHIGAN. A LOW PRESSURE CIRCULATION EMBEDDED WITHIN
THE TROUGH IS PUSHING FROM WESTERN WISCONSIN EASTWARD WITH VERY
STRONG PRESSURE FALLS OVER LAKE MICHIGAN THANKS TO THE DIFFERENCE IN
PRESSURE BETWEEN IT AND THE HIGH TO THE SOUTHEAST. SOUTHWEST GALES
CONTINUE ACROSS THE SOUTHERN TWO-THIRDS OR SO OF THE LAKE WITH THE
FAR NORTH IN THE TROUGH AXIS RESULTING IN LIGHTER WINDS. THE LOW
WILL CROSS THE LAKE THIS EVENING ALLOWING WINDS TO EASE FROM
NORTHWEST TO SOUTHEAST THROUGH THE EVENING. NORTH-CENTRAL SECTIONS
OF THE LAKE SHOULD SEE WINDS EASE THIS EVENING WITH IT TAKING UNTIL
AROUND MIDNIGHT OR SOON AFTER FOR GALES TO DIMINISH SOUTH. WILL
LET THE GALE WARNING GO AS-IS FOR NOW BUT IT MAY BE ABLE TO BE
CANCELLED EARLY NORTH. FOR THE NEARSHORE WATERS...WILL END THE
ILLINOIS SHORES A BIT EARLIER BUT CARRY THE INDIANA SHORELINE
UNTIL 09Z AS SCHEDULED BUT IT IS POSSIBLE THIS MAY NEED TO BE
SHORTENED. EXPECT THAT A SMALL CRAFT ADVISORY WILL BE NEEDED ONCE
GALES DIMINISH.
A SECOND LOW WILL DEEPEN ACROSS SASKATCHEWAN TONIGHT AND MOVE TO
WESTERN LAKE SUPERIOR BY SATURDAY AFTERNOON. THE LOW WILL THEN
FURTHER DEEPEN AS IT CROSSES THE U.P. OF MICHIGAN SATURDAY EVENING
AND HEADS TOWARD SOUTHERN QUEBEC BY SUNDAY MORNING. SOUTH TO
SOUTHWEST WINDS WILL INTENSIFY SATURDAY WITH LOWER END GALES
EXPECTED TO BEGIN DURING THE EARLY AFTERNOON ACROSS THE OPEN
WATERS...WITH NEARSHORE AREAS LIKELY HOLDING INTO THE UPPER 20S TO
ABOUT 30 KT. WILL PUSH THE START TIME OF THE GALE WATCH FOR THE
NEARSHORE WATERS LATER TO 00Z BUT UPGRADE TO A GALE WARNING FOR THE
OPEN WATERS FROM 18Z ON WITH THE NORTHERN TWO-THIRDS EXPECTED TO SEE
GALES DURING THE AFTERNOON. WINDS WILL TURN WESTERLY THEN
NORTHWESTERLY SATURDAY EVENING AS THE LOW AND A COLD FRONT PASS WITH
MUCH COLDER AIR ARRIVING. THE COMBINATION OF COLD ADVECTION AND THE
DEEPENING LOW PASSING NORTH OF THE LAKE WILL BE VERY FAVORABLE FOR
HIGH END GALES ACROSS MUCH OF THE LAKE SATURDAY EVENING AND EARLY
SATURDAY NIGHT BEFORE EASING SUNDAY MORNING. IT DOES APPEAR THAT A
3-6 HR PERIOD WILL BE FAVORABLE FOR A FEW STORM FORCE GUSTS TO 50 KT
ROUGHLY BETWEEN 03 AND 06 OR 09Z ACROSS CENTRAL PORTIONS OF THE
LAKE. WILL HIGHLIGHT THIS IN THE TEXT FOR NOW. WITH THE COLDER
AIR...HEAVY FREEZING SPRAY IS ALSO A CONCERN LATE SATURDAY EVENING
THROUGH SUNDAY MORNING AS AIR TEMPS FALL INTO THE MID/UPPER TEENS.
WILL ISSUE A HEAVY FREEZING SPRAY WATCH FROM 06 TO 18Z SUNDAY.
WINDS WILL EASE SUNDAY MORNING AS THE LOW DEPARTS BUT THE STEADY
FLOW OF COLDER AIR AND A TIGHT PRESSURE GRADIENT WILL KEEP WINDS
ELEVATED THROUGH EARLY NEXT WEEK AND MAY BE MODULATED UP AND DOWN
BY PASSING WEAK LOWS. HIGH PRESSURE DOES LOOK TO EVENTUALLY ARRIVE
OVER THE LAKE DURING THE MID OR LATE PART OF THE WEEK WHICH WOULD
PROVIDE MUCH LIGHTER WINDS.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ366-LMZ565-LMZ567-LMZ669-LMZ671-LMZ673-
LMZ675-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ868-LMZ870-
LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 3 AM SATURDAY.
GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...NOON SATURDAY TO 9 AM
SUNDAY.
HEAVY FREEZING SPRAY WATCH...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-
LMZ563-LMZ565-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-
LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...MIDNIGHT SUNDAY TO
NOON SUNDAY.
GALE WATCH...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745...6 PM
SATURDAY TO 9 AM SUNDAY.
GALE WARNING...ILLINOIS NEARSHORE WATERS UNTIL 10 PM FRIDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CARIBOU ME
509 AM EST THU JAN 17 2013
.SYNOPSIS...
LOW PRESSURE WILL QUICKLY TO THE EAST LATE TONIGHT. A STRONG
ARCTIC COLD FRONT WILL CROSS THE STATE THURSDAY. HIGH PRESSURE
WILL BUILD EAST FRIDAY...WHILE LOW PRESSURE TRACKS SOUTH OF THE
GULF OF MAINE. LOW PRESSURE WILL TRACK TOWARDS THE REGION ON SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
MOST OF THE FA IS NOW IN A BREAK BETWEEN SN SHWR ACTION TO OUR E
AND NEW SN SHWRS ADVCG EWRD INTO THE REGION FROM QB. IN ADDITION...
A SN SQUALL IS CURRENTLY APCHG THE ST LAWRENCE RVR VLY OF ERN QB
WITH SEVERAL OBS INDICATING WIND GUSTS TO 40 TO 45 MPH AND NEAR
WHITEOUT CONDITIONS OCCURRING WITH THE SQUALL. HRRR GUIDANCE
INDICATES THAT SOME PORTION OF THIS LN OF SN SHWRS WILL GET INTO
OUR FA THIS MORN...BUT NOT SURE HOW INTENSE THE LN WILL CONTINUE
AS IT MOVES TOWARD NB. WE DID GO WITH LIKELY POPS FOR NRN AREAS
AND CHC POPS SRN AREAS...HIGHLIGHTING AN HRLY PROGRESSION ACROSS
THE REGION FROM 12-16Z. IF WORSE COMES TO WORSE...WE CAN ISSUE A
BLOWING SN ADV TO HIGHLIGHT THE PRESENCE OF THIS SN SQUALL AS IT
MOVES E THRU SPCLY NRN PTNS OF THE FA WHERE POWDERY SN FELL LAST
NGT.
BEHIND THE FRONT...TEMPS DROP UP TO 10 TO 15 DEG F WITHIN AN
HR...AND THEN CONT TO FALL OFF GRADUALLY THRU THE REMAINDER OF THE
AFT WITH BRISK N TO NW WINDS OF 15 TO 25 MPH. THE COMBO OF
LOWERING TEMPS AND WINDS HAS WARRANTED A WIND CHILL ADV FOR
NW AND FAR NERN ME BEGINNING LATE THIS AFTN AND CONTG THRU THE
EVE. WITH WINDS DIMINISHING BLO 5 MPH BY MDNGT OVR NRN PTNS OF THE
FA AS A RIDGE OF HI PRESS SETTLES OVR THE REGION...WE BELIEVE THE
WIND CHILL ADV FOR THE NW AND FAR NE WILL NO LONGER BE NEEDED AFT
MDNGT. E CNTRL AND SPCLY DOWNEAST AREAS WILL BE NEAR THE -20 DEG
WIND CHILL CRITERIA LATER TNGT INTO FRI MORN AS WINDS REMAIN A
LITTLE STRONGER DUE TO BEING IN THE FAR NRN PTN OF THE GRADIENT
ASSOCIATED WITH LOW PRESSURE MOVG NE IN THE OPEN ATLC...SO WE
CANNOT RULE OUT THE POSSIBILITY OF ANOTHER WIND CHILL ADV MAY NEED
TO BE ISSUED OVR THIS PTN OF THE FA BY THE AFTN FCST UPDATE.
LASTLY...WITH MCLR SKIES AND SLACKENING EVE WINDS...ARCTIC INVSN
CONDITIONS ARE A GOOD BET FOR OUR NW VLYS LATE TNGT...BRINGING THE
COLDEST LOW TEMPS...OF THE SEASON SO FAR...PERHAPS AS LOW 30 BELOW
ZERO FOR COLDEST LOCATIONS.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
HIGH PRESSURE DOMINATES FRIDAY WITH BITTERLY COLD TEMPERATURES.
HIGHS WILL BE IN THE ZERO TO FIVE BELOW RANGE NORTH OF HOULTON AND
SINGLE DIGITS FOR BANGOR AND DOWN EAST. COASTAL LOCATIONS MAY JUST
EDGE INTO THE LOW TEENS. WITH WINDS OVER 10 MPH BY MID TO LATE
MORNING...EXPECT A STRONG POSSIBILITY OF A WIND CHILL ADVISORY.
WIND CHILLS WILL BE -20F TO -30F ALL DAY NORTH OF HOULTON AND
NEAR -20F AROUND BANGOR IN THE MORNING. TEMPERATURES WILL FALL
QUICKLY FRIDAY EVENING TOWARDS MINUS 10F IN THE CROWN OF MAINE AND
TOWARDS ZERO FOR DOWN EAST. HOWEVER...A FAST-MOVING CLIPPER SYSTEM
WILL ARRIVE AFTER MIDNIGHT WITH THICKENING CLOUDS. THUS LOWS WILL
OCCUR NEAR MIDNIGHT AND TEMPERATURES WILL RISE AFTER WARDS. THIS
CLIPPER WILL PRODUCE LIGHT OVERRUNNING SNOW LATE FRIDAY NIGHT
THROUGH THE DAY SATURDAY. ANTICIPATE AMOUNTS IN THE ONE TO TWO
INCH RANGE IN NORTHERN ZONES...BUT LESS THAN AN INCH DOWN EAST.
SOUTHERLY WINDS WILL ALLOW TEMPERATURES TO RISE FROM LATE FRIDAY
NIGHT THROUGH THE DAY ON SATURDAY...REACHING THE LOW TO MID 30S
ALONG THE COAST AND LOW 20S IN NORTHERN AROOSTOOK COUNTY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
A LOW PRESSURE SYSTEM WILL INTENSIFY IN THE NORTHERN GREAT LAKES
REGION LATE SATURDAY THROUGH SUNDAY MORNING WITH A WARM FRONT
EXTENDING EAST INTO NORTHERN MAINE. THE OVERRUNNING SNOW IS
EXPECTED TO CONTINUE SATURDAY NIGHT AND INCREASE AFTER MIDNIGHT AS
THE LOW MOVES INTO QUEBEC. TEMPERATURES WILL NOT FALL MUCH WITH
THE CONTINUING WARM AIR ADVECTION. SOME RAIN MAY MIX WITH THE SNOW
IN ZONES 29 AND 30 ALONG THE COAST. THE LATEST NWP GUIDANCE IS
SHOWING THE LOW TRACKING FURTHER TO THE NORTH DURING SUNDAY...WITH
THE MOST LIKELY TRACK JUST NORTH OF THE SJV. THE RESULT WILL BE AN
ADDITIONAL SEVERAL INCHES OF SNOW IN THE CROWN OF MAINE...BUT
LITTLE IF ANY ACCUMULATION DOWN EAST. HIGHS ON SUNDAY WILL REACH
THE MID TO UPPER 20S NORTH OF HOULTON AND LOW TO MID 30S SOUTH OF
HOULTON. THE COLD FRONT FOLLOWING THIS LOW WILL USHER IN ANOTHER
ROUND OF BITTERLY COLD TEMPERATURES. TEMPERATURES WILL PLUMMET TO
5 TO 10 BELOW ZERO IN NORTHERN ZONES SUNDAY NIGHT WHILE SINGLE
DIGITS ARE EXPECTED FOR BANGOR AND VICINITY. HIGHS WILL STRUGGLE
TO REACH ZERO FOR NORTHERN ZONES MONDAY THROUGH THURSDAY. LOWS
WILL BE WELL BELOW ZERO. THE BIG QUESTION WILL BE WHETHER WINDS
AND CLOUDS ALLOW DECOUPLING OF THE BOUNDARY LAYER AND PRODUCE
READINGS AS LOW AS 30 BELOW. THE FIRST CHANCE AT THIS WRITING
APPEARS TO BE MONDAY NIGHT. WILL GO FOR MINUS 10 AROUND BANGOR AND
LESS THAN MINUS 20 NORTH OF HOULTON ON MONDAY NIGHT. WITH THIS
COLD AIR IN PLACE...STORM SYSTEMS ARE EXPECTED TO PASS TO OUR
SOUTH FOR MONDAY INTO THURSDAY.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
NEAR TERM: IFR AND MVFR CONDITIONS WILL IMPROVE TO VFR BY THIS
AFTN ACROSS DOWNEAST SITES BEHIND AN ARCTIC FRONT AND BY LATE
AFTN OVR NRN TAF SITES AFT A PD OF BLOWING AND DRIFTING SNOW
BEHIND THE ARCTIC FRONT. BRIEF WHITEOUT CONDITIONS MAY OCCUR AT
NRN TAF SITES WITH SN SQL ACTIVITY WITH THE COLD FRONT. ALL SITES
WILL THEN REMAIN VFR TNGT.
SHORT TERM: VFR FRIDAY INTO FRIDAY EVENING. BECOMING MVFR LATE
FRIDAY NIGHT THROUGH SATURDAY NIGHT. FROM HUL NORTHWARD...EXPECT
IFR LATER SATURDAY NIGHT THROUGH SUNDAY WHILE TERMINALS SOUTH OF
HUL WILL REMAIN MVFR SUNDAY. ALL AREAS WILL BE VFR MONDAY.
&&
.MARINE...
NEAR TERM: WILL CONT WITH AN SCA FOR WINDS BEHIND A DEPARTING LOW
PRES SYSTEM IN THE MARITIMES AND ALSO BEHIND ARCTIC COLD FRONT
XPCTD TO CROSS THE WATERS THIS AFTN. IN ADDITION TO SCA WINDS AND
SEAS...COLDER AIR WILL CREATE THE POTENTIAL OF MDT FZG SPY LATE
TNGT AFT MDNGT. WW3 WV HTS WERE ABOUT 2 FT TO LOW COMPARED TO
OBSVD BUOY WV HTS ERLY THIS MORN...SO WE BLENDED SWAN GFS
GUIDANCE AND ADDED ANOTHER FOOT TO IT FOR THIS MORN...THEN BLENDED
CLOSER TO WW3 GUIDANCE FOR TNGT.
SHORT TERM: AN SCA WILL CONTINUE FRIDAY. THERE MAY BE A BIT OF
RESPITE LATE FRIDAY AFTERNOON UNTIL AFTER MIDNIGHT FRIDAY NIGHT
BEFORE SCA CONDITIONS RETURN. GALE CONDITIONS ARE POSSIBLE DURING
SATURDAY AND AGAIN DURING SUNDAY WITH WIND GUSTS OVER 40 KTS
POSSIBLE...ESPECIALLY ON SUNDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WIND CHILL ADVISORY FROM 4 PM THIS AFTERNOON TO MIDNIGHT EST
TONIGHT FOR MEZ001>004-010.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST FRIDAY FOR ANZ050>052.
&&
$$
NEAR TERM...VJN
SHORT TERM...MCW
LONG TERM...MCW
AVIATION...VJN
MARINE...VJN/MCW
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1122 AM CST THU JAN 17 2013
.AVIATION...18Z TAF ISSUANCE...
MVFR CLOUD DECK IN PLACE ACROSS THE NORTHLAND THIS MORNING WILL
SLOWLY DISSIPATE THROUGH THE AFTERNOON FROM NORTH TO SOUTH. A FEW
LINGERING LIGHT SNOW SHOWERS OR FLURRIES WILL EVENTUALLY COME TO
AN END BY MID AFTERNOON. THE NEXT SYSTEM WILL MOVE IN QUICKLY FROM
THE SW TONIGHT AND SPREAD LOW-END MVFR/IFR CIGS AND IFR VSBYS IN
-SN ACROSS THE REGION. W/NW WINDS TODAY WILL SHIFT TO THE SOUTH
TONIGHT...AROUND 5-10 KT.
&&
.PREV DISCUSSION... /ISSUED 1007 AM CST THU JAN 17 2013/
UPDATE...
MADE UPDATES TO THE FORECAST THROUGH TONIGHT. THIS WAS TO INCREASE
CLOUD COVER TODAY. IT SHOULD TAKE SOME TIME FOR THE CLOUDY SKIES
ACROSS THE NORTHLAND TO MOVE EAST AND/OR DISSIPATE...BUT GENERALLY
THERE SHOULD BE DECREASING CLOUD COVER THIS AFTERNOON FROM WEST TO
EAST. ALSO...THERE WAS NOT A MENTION OF FLURRIES FOR MOST OF THE
NORTHLAND...YET THESE LOW CLOUDS ARE PRODUCING FLURRIES HERE AND
THERE. THEREFORE...ADDED FLURRIES FOR MOST OF THE NORTHLAND
THROUGH THE FIRST HALF OF THE AFTERNOON. CANCELLED THE WIND CHILL
ADVISORY FOR NORTHERN ST. LOUIS COUNTY...KOOCHICHING COUNTY...AND
THE SOUTHERN PART OF THE NORTH SHORE SINCE THE WIND CHILL VALUES
HAVE IMPROVED WITH THE INCREASING TEMPERATURES. ALSO MADE CHANGES
TO THE FORECAST FOR TONIGHT TO BETTER TIME THE LIKELY SNOW THAT
WILL MOVE INTO THE FA WITH THE WARM AIR ADVECTION ALOFT.
PREV DISCUSSION... /ISSUED 554 AM CST THU JAN 17 2013/
AVIATION...12Z TAFS
CEILINGS FROM 3500-5000FEET COVERED MUCH OF THE NORTHLAND THIS
MORNING...WITH MVFR CEILINGS AND LIGHT SNOW MOVING TOWARD KBRD.
THESE LOWER CEILINGS ARE FORECAST BY THE RAP TO AFFECT
KHIB/KDLH/KHYR LATER TODAY...AND WE PUT THEM IN THE LATEST TAF.
CLOUDS WILL DIMINISH LATER THIS AFTERNOON/EARLY EVENING...BEFORE
INCREASING AGAIN OVERNIGHT IN AN AREA OF WAA. SOME LIGHT SNOW MAY
ALSO DEVELOP LATE TONIGHT.
PREV DISCUSSION... /ISSUED 410 AM CST THU JAN 17 2013/
SHORT TERM...TODAY THROUGH FRIDAY.
AT 4 AM...CLOUDS WERE ON THE INCREASE ACROSS THE CWA. THE RESULT
WAS A BIT OF IMPROVEMENT IN TEMPS AND WIND CHILL READINGS. HAVE
REMOVED ITASCA COUNTY...AND THE DULUTH AND SUPERIOR AREAS FROM THE
WIND CHILL ADVISORY...AS WIND CHILL READINGS HAD IMPROVED A BIT.
WILL LIKELY BE ABLE TO REMOVE OTHER COUNTIES AS THE MORNING WEARS
ON DUE TO THE INCREASING CLOUDS.
THE MAIN FOCUS FOR TODAY WILL BE THE WIND CHILL READINGS THIS
MORNING...ALONG WITH CLOUD TRENDS. THERE WILL LIKELY BE SOME
DECREASE IN CLOUDS ACROSS THE CWA TODAY. THE NAM ACTUALLY PICKS UP
ON THE BAND OF CLOUDS MOVING INTO NORTHERN MN...AND IT CARRIES
THAT SHORTWAVE TO THE EAST AS THE DAY WEARS ON. HIGH TEMPS WILL
LIKELY REMAIN A BIT BELOW ZERO IN THE FAR NORTH TODAY...BUT WILL
APPROACH 10 ABOVE IN THE SOUTH.
THE MAIN FOCUS FOR TONIGHT AND FRIDAY IS THE DEVELOPING LOW
PRESSURE SYSTEM THAT IS EXPECTED TO SLIDE INTO THE LAKE SUPERIOR
REGION THROUGH THE END OF THE WEEK. HAVE INCREASED POPS
CONSIDERABLY LATER TONIGHT AND INTO FRIDAY. COULD SEE SOME 2 TO 4
INCH AMOUNTS IN THE NORTH...AND POSSIBLY EVEN 3 TO 5 ACROSS THE
ARROWHEAD. WILL ALSO NEED TO WATCH THE NORTH SHORE FOR THE
POSSIBILITY OF LOCALIZED HIGHER AMOUNTS DUE TO LAKE ENHANCEMENT.
MAY NEED TO ISSUE ADVISORIES FOR PORTIONS OF THE NORTHLAND IN
LATER FORECAST PACKAGES. TEMPERATURES WILL WARM CONSIDERABLY ON
FRIDAY...ESPECIALLY ACROSS THE SOUTH...AS THE SOUTHERN HALF OF THE
CWA SHOULD BE IN THE WARM SECTOR DURING THE DAY.
LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY.
MUCH COLDER TEMPERATURES WILL BE MOVING INTO THE NORTHLAND IN THE
EXTENDED PERIOD.
A COUPLE SHORTWAVES WILL AFFECT THE NORTHLAND FRIDAY NIGHT INTO
SATURDAY...WITH THE STRONGER WAVE/LOW OCCURRING SATURDAY. LIGHT SNOW
WILL OCCUR FRIDAY NIGHT...MAINLY NORTH WITH OVERNIGHT ACCUMULATIONS
MAINLY RANGING FROM A DUSTING TO PERHAPS AN INCH. THE STRONGER WAVE
ON SATURDAY WILL BE ACCOMPANIED BY A DEEPENING LOW AND AS THEY
PASS...MUCH COLDER AIR WILL POUR INTO THE REGION. SOME ADDITIONAL
SNOWFALL WILL OCCUR SATURDAY...AGAIN MAINLY NORTH AND AMOUNTS WILL
BE SOMEWHAT LIMITED FOR MOST AREAS. A FEW INCHES WILL BE POSSIBLE
OVER THE ARROWHEAD. WE INCREASED TEMPS FRIDAY NIGHT INTO
SATURDAY...BEFORE THE COLD AIR MOVES IN. TEMPERATURES WILL START TO
FALL LATER SATURDAY...ESPECIALLY OVER OUR MINNESOTA ZONES. STRONG
WEST-NORTHWEST WINDS WILL DEVELOP SATURDAY INTO SATURDAY NIGHT...AND
WE INCREASED THEM QUITE A BIT. A WIND CHILL ADVISORY WILL LIKELY BE
NEEDED SATURDAY NIGHT OVER OUR MINNESOTA ZONES...AND EXTREME
NORTHWEST WISCONSIN ZONES.
OUTSIDE OF AN EXTENDED PERIOD OF LAKE EFFECT OF SNOW ALONG PORTIONS
OF THE SOUTH SHORE...THE MAIN FOCUS SATURDAY NIGHT INTO WEDNESDAY
WILL BE THE COLD. LOW WILL DROP INTO THE TEENS BELOW ZERO SATURDAY
NIGHT OVER OUR NORTHERN ZONES...AND SINGLE DIGITS BELOW OVER
NORTHWEST WISCONSIN. WE HAVE TEENS TO AROUND 25 BELOW ZERO SUNDAY
NIGHT AND MONDAY NIGHT AND TEENS BELOW TUESDAY NIGHT. HIGHS SUNDAY
WILL REMAIN AT OR BELOW ZERO OVER MOST OF NORTHEAST MINNESOTA...AND
ZERO TO 5 ABOVE IN NORTHWEST WISCONSIN...AND BE A FEW DEGREES COLDER
ON MONDAY.
A FAVORABLE PERIOD OF LES WILL OCCUR SATURDAY NIGHT INTO SUNDAY
NIGHT...ALTHOUGH 850MB TEMPERATURES WILL BE VERY COLD BY SUNDAY
NIGHT WHICH MAY LIMIT SNOW ACCUMULATIONS. SOME SIGNIFICANT SNOW
ACCUMULATIONS WILL BE POSSIBLE IN THE SNOWBELT SATURDAY NIGHT INTO
SUNDAY.
&&
.POINT TEMPS/POPS...
DLH 6 -3 26 20 / 10 60 70 30
INL 0 -13 17 7 / 10 60 70 50
BRD 9 1 32 19 / 20 60 20 10
HYR 8 -2 34 17 / 30 60 60 20
ASX 9 -1 29 18 / 10 30 70 30
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WIND CHILL ADVISORY UNTIL NOON CST TODAY FOR MNZ012-021.
WI...NONE.
LS...NONE.
&&
$$
AVIATION...TENTINGER
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1007 AM CST THU JAN 17 2013
.UPDATE...
MADE UPDATES TO THE FORECAST THROUGH TONIGHT. THIS WAS TO INCREASE
CLOUD COVER TODAY. IT SHOULD TAKE SOME TIME FOR THE CLOUDY SKIES
ACROSS THE NORTHLAND TO MOVE EAST AND/OR DISSIPATE...BUT GENERALLY
THERE SHOULD BE DECREASING CLOUD COVER THIS AFTERNOON FROM WEST TO
EAST. ALSO...THERE WAS NOT A MENTION OF FLURRIES FOR MOST OF THE
NORTHLAND...YET THESE LOW CLOUDS ARE PRODUCING FLURRIES HERE AND
THERE. THEREFORE...ADDED FLURRIES FOR MOST OF THE NORTHLAND
THROUGH THE FIRST HALF OF THE AFTERNOON. CANCELLED THE WIND CHILL
ADVISORY FOR NORTHERN ST. LOUIS COUNTY...KOOCHICHING COUNTY...NAD
THE SOUTHERN PART OF THE NORTH SHORE SINCE THE WIND CHILL VALUES
HAVE IMPROVED WITH THE INCREASING TEMPERATURES. ALSO MADE CHANGES
TO THE FORECAST FOR TONIGHT TO BETTER TIME THE LIKELY SNOW THAT
WILL MOVE INTO THE FA WITH THE WARM AIR ADVECTION ALOFT.
&&
.PREV DISCUSSION... /ISSUED 554 AM CST THU JAN 17 2013/
AVIATION...12Z TAFS
CEILINGS FROM 3500-5000FEET COVERED MUCH OF THE NORTHLAND THIS
MORNING...WITH MVFR CEILINGS AND LIGHT SNOW MOVING TOWARD KBRD.
THESE LOWER CEILINGS ARE FORECAST BY THE RAP TO AFFECT
KHIB/KDLH/KHYR LATER TODAY...AND WE PUT THEM IN THE LATEST TAF.
CLOUDS WILL DIMINISH LATER THIS AFTERNOON/EARLY EVENING...BEFORE
INCREASING AGAIN OVERNIGHT IN AN AREA OF WAA. SOME LIGHT SNOW MAY
ALSO DEVELOP LATE TONIGHT.
PREV DISCUSSION... /ISSUED 410 AM CST THU JAN 17 2013/
SHORT TERM...TODAY THROUGH FRIDAY.
AT 4 AM...CLOUDS WERE ON THE INCREASE ACROSS THE CWA. THE RESULT
WAS A BIT OF IMPROVEMENT IN TEMPS AND WIND CHILL READINGS. HAVE
REMOVED ITASCA COUNTY...AND THE DULUTH AND SUPERIOR AREAS FROM THE
WIND CHILL ADVISORY...AS WIND CHILL READINGS HAD IMPROVED A BIT.
WILL LIKELY BE ABLE TO REMOVE OTHER COUNTIES AS THE MORNING WEARS
ON DUE TO THE INCREASING CLOUDS.
THE MAIN FOCUS FOR TODAY WILL BE THE WIND CHILL READINGS THIS
MORNING...ALONG WITH CLOUD TRENDS. THERE WILL LIKELY BE SOME
DECREASE IN CLOUDS ACROSS THE CWA TODAY. THE NAM ACTUALLY PICKS UP
ON THE BAND OF CLOUDS MOVING INTO NORTHERN MN...AND IT CARRIES
THAT SHORTWAVE TO THE EAST AS THE DAY WEARS ON. HIGH TEMPS WILL
LIKELY REMAIN A BIT BELOW ZERO IN THE FAR NORTH TODAY...BUT WILL
APPROACH 10 ABOVE IN THE SOUTH.
THE MAIN FOCUS FOR TONIGHT AND FRIDAY IS THE DEVELOPING LOW
PRESSURE SYSTEM THAT IS EXPECTED TO SLIDE INTO THE LAKE SUPERIOR
REGION THROUGH THE END OF THE WEEK. HAVE INCREASED POPS
CONSIDERABLY LATER TONIGHT AND INTO FRIDAY. COULD SEE SOME 2 TO 4
INCH AMOUNTS IN THE NORTH...AND POSSIBLY EVEN 3 TO 5 ACROSS THE
ARROWHEAD. WILL ALSO NEED TO WATCH THE NORTH SHORE FOR THE
POSSIBILITY OF LOCALIZED HIGHER AMOUNTS DUE TO LAKE ENHANCEMENT.
MAY NEED TO ISSUE ADVISORIES FOR PORTIONS OF THE NORTHLAND IN
LATER FORECAST PACKAGES. TEMPERATURES WILL WARM CONSIDERABLY ON
FRIDAY...ESPECIALLY ACROSS THE SOUTH...AS THE SOUTHERN HALF OF THE
CWA SHOULD BE IN THE WARM SECTOR DURING THE DAY.
LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY.
MUCH COLDER TEMPERATURES WILL BE MOVING INTO THE NORTHLAND IN THE
EXTENDED PERIOD.
A COUPLE SHORTWAVES WILL AFFECT THE NORTHLAND FRIDAY NIGHT INTO
SATURDAY...WITH THE STRONGER WAVE/LOW OCCURRING SATURDAY. LIGHT SNOW
WILL OCCUR FRIDAY NIGHT...MAINLY NORTH WITH OVERNIGHT ACCUMULATIONS
MAINLY RANGING FROM A DUSTING TO PERHAPS AN INCH. THE STRONGER WAVE
ON SATURDAY WILL BE ACCOMPANIED BY A DEEPENING LOW AND AS THEY
PASS...MUCH COLDER AIR WILL POUR INTO THE REGION. SOME ADDITIONAL
SNOWFALL WILL OCCUR SATURDAY...AGAIN MAINLY NORTH AND AMOUNTS WILL
BE SOMEWHAT LIMITED FOR MOST AREAS. A FEW INCHES WILL BE POSSIBLE
OVER THE ARROWHEAD. WE INCREASED TEMPS FRIDAY NIGHT INTO
SATURDAY...BEFORE THE COLD AIR MOVES IN. TEMPERATURES WILL START TO
FALL LATER SATURDAY...ESPECIALLY OVER OUR MINNESOTA ZONES. STRONG
WEST-NORTHWEST WINDS WILL DEVELOP SATURDAY INTO SATURDAY NIGHT...AND
WE INCREASED THEM QUITE A BIT. A WIND CHILL ADVISORY WILL LIKELY BE
NEEDED SATURDAY NIGHT OVER OUR MINNESOTA ZONES...AND EXTREME
NORTHWEST WISCONSIN ZONES.
OUTSIDE OF AN EXTENDED PERIOD OF LAKE EFFECT OF SNOW ALONG PORTIONS
OF THE SOUTH SHORE...THE MAIN FOCUS SATURDAY NIGHT INTO WEDNESDAY
WILL BE THE COLD. LOW WILL DROP INTO THE TEENS BELOW ZERO SATURDAY
NIGHT OVER OUR NORTHERN ZONES...AND SINGLE DIGITS BELOW OVER
NORTHWEST WISCONSIN. WE HAVE TEENS TO AROUND 25 BELOW ZERO SUNDAY
NIGHT AND MONDAY NIGHT AND TEENS BELOW TUESDAY NIGHT. HIGHS SUNDAY
WILL REMAIN AT OR BELOW ZERO OVER MOST OF NORTHEAST MINNESOTA...AND
ZERO TO 5 ABOVE IN NORTHWEST WISCONSIN...AND BE A FEW DEGREES COLDER
ON MONDAY.
A FAVORABLE PERIOD OF LES WILL OCCUR SATURDAY NIGHT INTO SUNDAY
NIGHT...ALTHOUGH 850MB TEMPERATURES WILL BE VERY COLD BY SUNDAY
NIGHT WHICH MAY LIMIT SNOW ACCUMULATIONS. SOME SIGNIFICANT SNOW
ACCUMULATIONS WILL BE POSSIBLE IN THE SNOWBELT SATURDAY NIGHT INTO
SUNDAY.
&&
.POINT TEMPS/POPS...
DLH 6 -3 26 20 / 10 60 70 30
INL 0 -13 17 7 / 10 60 70 50
BRD 9 1 32 19 / 10 60 20 10
HYR 8 -2 34 17 / 10 60 60 20
ASX 9 -1 29 18 / 10 30 70 30
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WIND CHILL ADVISORY UNTIL NOON CST TODAY FOR MNZ012-021.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...GROCHOCINSKI
LONG TERM....TENTINGER
AREA FORECAST DISCUSSION
NWS DULUTH MN
554 AM CST THU JAN 17 2013
.AVIATION...12Z TAFS
CEILINGS FROM 3500-5000FEET COVERED MUCH OF THE NORTHLAND THIS
MORNING...WITH MVFR CEILINGS AND LIGHT SNOW MOVING TOWARD KBRD.
THESE LOWER CEILINGS ARE FORECAST BY THE RAP TO AFFECT
KHIB/KDLH/KHYR LATER TODAY...AND WE PUT THEM IN THE LATEST TAF.
CLOUDS WILL DIMINISH LATER THIS AFTERNOON/EARLY EVENING...BEFORE
INCREASING AGAIN OVERNIGHT IN AN AREA OF WAA. SOME LIGHT SNOW MAY
ALSO DEVELOP LATE TONIGHT.
&&
.PREV DISCUSSION... /ISSUED 410 AM CST THU JAN 17 2013/
SHORT TERM...TODAY THROUGH FRIDAY.
AT 4 AM...CLOUDS WERE ON THE INCREASE ACROSS THE CWA. THE RESULT
WAS A BIT OF IMPROVEMENT IN TEMPS AND WIND CHILL READINGS. HAVE
REMOVED ITASCA COUNTY...AND THE DULUTH AND SUPERIOR AREAS FROM THE
WIND CHILL ADVISORY...AS WIND CHILL READINGS HAD IMPROVED A BIT.
WILL LIKELY BE ABLE TO REMOVE OTHER COUNTIES AS THE MORNING WEARS
ON DUE TO THE INCREASING CLOUDS.
THE MAIN FOCUS FOR TODAY WILL BE THE WIND CHILL READINGS THIS
MORNING...ALONG WITH CLOUD TRENDS. THERE WILL LIKELY BE SOME
DECREASE IN CLOUDS ACROSS THE CWA TODAY. THE NAM ACTUALLY PICKS UP
ON THE BAND OF CLOUDS MOVING INTO NORTHERN MN...AND IT CARRIES
THAT SHORTWAVE TO THE EAST AS THE DAY WEARS ON. HIGH TEMPS WILL
LIKELY REMAIN A BIT BELOW ZERO IN THE FAR NORTH TODAY...BUT WILL
APPROACH 10 ABOVE IN THE SOUTH.
THE MAIN FOCUS FOR TONIGHT AND FRIDAY IS THE DEVELOPING LOW
PRESSURE SYSTEM THAT IS EXPECTED TO SLIDE INTO THE LAKE SUPERIOR
REGION THROUGH THE END OF THE WEEK. HAVE INCREASED POPS
CONSIDERABLY LATER TONIGHT AND INTO FRIDAY. COULD SEE SOME 2 TO 4
INCH AMOUNTS IN THE NORTH...AND POSSIBLY EVEN 3 TO 5 ACROSS THE
ARROWHEAD. WILL ALSO NEED TO WATCH THE NORTH SHORE FOR THE
POSSIBILITY OF LOCALIZED HIGHER AMOUNTS DUE TO LAKE ENHANCEMENT.
MAY NEED TO ISSUE ADVISORIES FOR PORTIONS OF THE NORTHLAND IN
LATER FORECAST PACKAGES. TEMPERATURES WILL WARM CONSIDERABLY ON
FRIDAY...ESPECIALLY ACROSS THE SOUTH...AS THE SOUTHERN HALF OF THE
CWA SHOULD BE IN THE WARM SECTOR DURING THE DAY.
LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY.
MUCH COLDER TEMPERATURES WILL BE MOVING INTO THE NORTHLAND IN THE
EXTENDED PERIOD.
A COUPLE SHORTWAVES WILL AFFECT THE NORTHLAND FRIDAY NIGHT INTO
SATURDAY...WITH THE STRONGER WAVE/LOW OCCURRING SATURDAY. LIGHT SNOW
WILL OCCUR FRIDAY NIGHT...MAINLY NORTH WITH OVERNIGHT ACCUMULATIONS
MAINLY RANGING FROM A DUSTING TO PERHAPS AN INCH. THE STRONGER WAVE
ON SATURDAY WILL BE ACCOMPANIED BY A DEEPENING LOW AND AS THEY
PASS...MUCH COLDER AIR WILL POUR INTO THE REGION. SOME ADDITIONAL
SNOWFALL WILL OCCUR SATURDAY...AGAIN MAINLY NORTH AND AMOUNTS WILL
BE SOMEWHAT LIMITED FOR MOST AREAS. A FEW INCHES WILL BE POSSIBLE
OVER THE ARROWHEAD. WE INCREASED TEMPS FRIDAY NIGHT INTO
SATURDAY...BEFORE THE COLD AIR MOVES IN. TEMPERATURES WILL START TO
FALL LATER SATURDAY...ESPECIALLY OVER OUR MINNESOTA ZONES. STRONG
WEST-NORTHWEST WINDS WILL DEVELOP SATURDAY INTO SATURDAY NIGHT...AND
WE INCREASED THEM QUITE A BIT. A WIND CHILL ADVISORY WILL LIKELY BE
NEEDED SATURDAY NIGHT OVER OUR MINNESOTA ZONES...AND EXTREME
NORTHWEST WISCONSIN ZONES.
OUTSIDE OF AN EXTENDED PERIOD OF LAKE EFFECT OF SNOW ALONG PORTIONS
OF THE SOUTH SHORE...THE MAIN FOCUS SATURDAY NIGHT INTO WEDNESDAY
WILL BE THE COLD. LOW WILL DROP INTO THE TEENS BELOW ZERO SATURDAY
NIGHT OVER OUR NORTHERN ZONES...AND SINGLE DIGITS BELOW OVER
NORTHWEST WISCONSIN. WE HAVE TEENS TO AROUND 25 BELOW ZERO SUNDAY
NIGHT AND MONDAY NIGHT AND TEENS BELOW TUESDAY NIGHT. HIGHS SUNDAY
WILL REMAIN AT OR BELOW ZERO OVER MOST OF NORTHEAST MINNESOTA...AND
ZERO TO 5 ABOVE IN NORTHWEST WISCONSIN...AND BE A FEW DEGREES COLDER
ON MONDAY.
A FAVORABLE PERIOD OF LES WILL OCCUR SATURDAY NIGHT INTO SUNDAY
NIGHT...ALTHOUGH 850MB TEMPERATURES WILL BE VERY COLD BY SUNDAY
NIGHT WHICH MAY LIMIT SNOW ACCUMULATIONS. SOME SIGNIFICANT SNOW
ACCUMULATIONS WILL BE POSSIBLE IN THE SNOWBELT SATURDAY NIGHT INTO
SUNDAY.
&&
.POINT TEMPS/POPS...
DLH 4 -1 26 20 / 10 60 70 30
INL -4 -14 17 7 / 10 60 70 50
BRD 9 1 32 19 / 10 60 20 10
HYR 7 -3 34 17 / 10 60 60 20
ASX 6 -1 29 18 / 20 60 70 30
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WIND CHILL ADVISORY UNTIL NOON CST TODAY FOR MNZ010>012-019>021.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...DAP
LONG TERM....MELDE
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
424 AM CST THU JAN 17 2013
.DISCUSSION...
OVERVIEW...PATTERN STILL FAVORING A SERIES OF ALBERTA CLIPPERS
THROUGH THE EXTENDED. THE FIRST ARRIVES TONIGHT QUICK ON THE HEELS
OF A PASSING SURFACE HIGH. THIS WILL BRING LIGHT SNOW TO NORTHERN
MN THROUGH SATURDAY. WHILE LIGHT SNOW IS ALSO POSSIBLE IN CENTRAL
MN AND PORTIONS OF WESTERN WI...THE MAIN IMPACTS WILL BE THE
DRAMATIC ARCTIC FRONT ASSOCIATED WITH THIS SYSTEM. WINDS AND
FRIGID TEMPERATURES ARE STILL EXPECTED SATURDAY NIGHT THROUGH
SUNDAY. THE WIND WILL DIMINISH MONDAY...BUT THIS WILL BE ARE
COLDEST DAY OF THE SEASON SO FAR. MANY LOCATIONS WILL NOT CLIMB
ABOVE ZERO MONDAY. THE PATTERN LOOKS TO BECOME SLIGHTLY MORE
ACTIVE IN TERMS OF PRECIPITATION FOR THE LAST WEEK IN JANUARY.
STRATUS DECK IS SLOWLY ENGULFING SOUTHERN MN AND WESTERN WI THIS
MORNING. WITH NORTHWEST FLOW AND WEAK COLD AIR ADVECTION TODAY TO
GO ALONG WITH WHAT COULD AMOUNT TO A MOSTLY CLOUDY DAY...HARD TO
EXPECT MUCH WARMING THIS AFTERNOON. LOWERED TEMPS SLIGHTLY AND ARE
MAINLY ONLY RISING TEMPS 4-7 DEGREES FROM WHERE WE CURRENTLY SIT
THIS MORNING. AN ALBERTA CLIPPER COMES IN FAST TONIGHT...BUT THE
WAVE IS WEAK INITIALLY AND DOESN`T REALLY STRENGTHEN UNTIL
SATURDAY MORNING WHEN A VIGOROUS SHORT WAVE COMES CRUISING DOWN
FROM ALASKA. AT THAT POINT...THE SURFACE CYCLONE DEEPENS 5-10 MB
IN ROUGHLY 12 HOURS. THE CLIPPER SEEMS TO BE DIABATICALLY
INTERACTING WITH LAKE SUPERIOR...WHICH MAY BE CONTRIBUTING TO THE
DEEPENING. STILL HAVE LIGHT SNOW FORECASTED ACROSS CENTRAL MN IN
NORTHERN PORTIONS OF THE MPX FORECAST AREA. WE INITIALLY GAVE
MOISTURE OVER A LARGE DEPTH OF THE ATMOSPHERE THIS MORNING ACROSS
WESTERN/CENTRAL MN...BUT WE LOSE THE RH AT SOME POINT THIS
AFTERNOON. SO...LIKE WEDNESDAY MORNING...FREEZING DRIZZLE CAN NOT
BE COMPLETELY RULED OUT WHERE SNOW IS FORECASTED LATE THIS
EVENING. WE EVENTUALLY FEEL THE COLUMN WILL BE SATURATED ABOVE -10
C...SO LIGHT SNOW SHOULD BE THE DOMINATE P-TYPE BY SUNRISE FRIDAY
MORNING.
WE INCREASED MAX TEMPS ON FRIDAY GIVEN WHAT WE MANAGED YESTERDAY
AND WHAT IS EXPECTED WITH THE WARM FRONT. WE SHOULD SEE PLENTY OF
LOWER 40S IN SOUTHERN MN. THE LONE QUESTION WOULD BE IF THE SYSTEM
SLOWS DOWN BY 3-6 HOURS AND THE SURFACE WINDS REMAIN SOUTHEAST
LONGER ON FRIDAY. IT WOULD CERTAINLY STILL BE WELL ABOVE NORMAL IF
THE SLOWER SOLUTION WOULD HAPPEN...BUT HAD ENOUGH CONFIDENCE TO
BLEND IN SOME ECMWF AND BIAS CORRECTED ECMWF TO THE PREVIOUS
FORECAST TO GIVE US A BOOST IN TEMPS. THE SOUTHERLY FLOW IS STRONG
AND MIXING SHOULD BE GOOD FOR MID JANUARY. ANY SNOW ASSOCIATED
WITH THIS FIRST CLIPPER SYSTEM /THURSDAY NIGHT AND FRIDAY/ SHOULD
BE VERY MINOR AND THE MAIN IMPACTS WILL COME FROM THE ASSOCIATED
STRONG ARCTIC FRONT. THE COMBINATION OF THE DEEPENING CLIPPER AND
BUILDING HIGH IN THE DAKOTAS ESTABLISH A VERY NICE PACKING OF
ISOBARS AND THE 17.00Z GFS/ECMWF/NAM ALL SHOW 40-50 KTS OUT OF THE
NORTHWEST BEHIND THE ARCTIC BOUNDARY. WE INCREASED TEMPERATURES
SATURDAY GIVEN THE TIMING OF THIS BOUNDARY...WHICH SHOULD LEAVE
ROOM FOR A MILD JANUARY MORNING AND EVEN EARLY AFTERNOON ACROSS
THE FORECAST AREA. HOWEVER...THE FRONT COMES IN VERY FAST AND
WESTERN MN WILL ALREADY SEE DRAMATICALLY FALLING TEMPS AND STRONG
WINDS BY SATURDAY EVENING. WE WILL LIKELY NEED A WIND SHILL
ADVISORY AS EARLY AS 00Z SUNDAY WITH THIS SURGE.
A REINFORCING SHOT OF COLDER AIR ARRIVES SUNDAY...ALTHOUGH THE
MOST DRAMATIC CHANGES IN TEMPERATURE WILL STILL OCCUR
SATURDAY/SATURDAY NIGHT. WINDS CHILLS WILL BE IN THE -25 TO -40
RANGE LATE THIS WEEKEND AND ON MONDAY...AND MONDAY WILL STRUGGLE
TO REACH ZERO IN EASTERN MN AND WI. WESTERN PORTIONS OF THE
FORECAST AREA HAVE ALMOST NO CHANCE OF REACHING ZERO ON MONDAY.
THE EXTENDED FORECAST STILL POINTS TO A BREAKDOWN OF THE STRONG
RIDGING ALONG THE WEST COAST AND A RELAXATION OF THE DEEP
TROUGHING OVER THE EASTERN CONUS. THE PREVIOUS ECMWF ENSEMBLE
MEAN AND GEFS MEAN SHOW GOOD CORRELATION THROUGH NEXT WEEK WITH
THE INCOMING SYSTEM IN THE PACIFIC NORTHWEST NEXT
WEDNESDAY. LAST NIGHTS OPERATIONAL RUNS ARE COMING AROUND AS WELL.
CHANCES FOR MORE WIDESPREAD PRECIPITATION WILL INCREASE AS THE
WEST COAST WAVE MOVES THROUGH THE NORTHERN ROCKIES AND ONTO THE
NORTEHRN PLAINS BY MIDWEEK BUT ONLY MODEST QPF AMOUNTS ARE
FORECAST. THIS IS STILL A BREAK FROM WHAT WE`VE SEEN AROUND HERE
SINCE THE HOLIDAYS. AT THIS POINT THE SYSTEM LATE NEXT WEEK
REMAINS WARM ENOUGH TO CONSIDER A RAIN/SNOW MIX...BUT STILL WAY
TOO FAR OUT THERE TO GET SERIOUS ABOUT P-TYPE.
&&
.AVIATION.../06Z TAF ISSUANCE/
MAIN FORECAST CONCERN THIS TAF PERIOD IS THE POTENTIAL FOR MVFR
CIGS TO MOVE INTO THE AREA FROM THE NORTHWEST OVERNIGHT AND
THURSDAY MORNING. 11-3.9 MICRON SATELLITE IMAGERY SHOWS A BLOB OF
LLVL MOISTURE OVER NORTH DAKOTA ALONG THE WESTERN PERIPHERY OF THE
SURFACE RIDGE. BOTH THE HRRR /CLOUDBASE/ AND RAP /925-850MB MOISTURE/ PROGS
SHOW THIS AREA OF MOISTURE BETWEEN 2000 AND 4000 FT ADVECTING INTO
THE MN BETWEEN 08Z AND 12Z...AND WI ON THURSDAY MORNING. WILL
RETAIN A SCT-BKN MVFR LEVEL DECK IN THE TAF ACCORDINGLY. THE 925MB
LAYER IS PROGGED TO DRY OUT THURSDAY AFTERNOON /MN/ AND EARLY EVE
/WI/...BUT QUICKLY BE REPLACED BY A WEST TO EAST SURGE OF
850-700MB MOISTURE BETWEEN 03Z AND 12Z FRIDAY. WILL INTRODUCE SNOW
INTO KAXN AROUND 03Z FRIDAY...BUT ONSET FOR THE REMAINDER OF THE
SITES WILL MOST LIKELY BE BEYOND THIS TAF PERIOD. NORTHWEST WINDS
AT 5 TO 10 KTS WILL PREVAIL THROUGH THE PERIOD.
KMSP...SCT MVFR LEVEL CLOUDS /2000 FT/ WILL BE POSSIBLE AFTER 12Z
THURSDAY...ALONG WITH A BKN VFR DECK /3500 FT/. THE 2KFT DECK
COULD BRIEFLY GO BROKEN ON THURSDAY MORNING...BUT CONFIDENCE IS
NOT HIGH ON THAT. CLEARING ENSUES IN THE AFTERNOON...WITH ANOTHER
ROUND OF CLOUDS /LOW-END VFR CIGS/ ARRIVING AFTER 06Z FRIDAY.
/OUTLOOK FOR KMSP/
FRI...VFR. CHC OF -SN AND MVFR VIS/CIG IN MORNING. WIND SW 5-15
KTS.
SAT...MVFR CIGS LIKELY. AFTERNOON -SN POSSIBLE. W WIND 5 KTS BECOMING NW
15-20 KTS WITH GUSTS TO 30 KTS.
SUN...CHANCE OF -SN WITH MVFR OR LOWER CIG/VIS. WINDS W 5-10 KTS
BECOMING NW 15-20 KTS LATE.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
CLF/LS
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1050 PM CST WED JAN 16 2013
.UPDATE...FOR 06Z AVIATION DISCUSSION BELOW
&&
.DISCUSSION.../ISSUED 358 PM CST WED JAN 16 2013/
TONIGHT AND THURSDAY...LOW PRES TRIPLE POINT CENTER TRAVERSING ESE
THRU WRN WI WITH THE CDFNT SNAKING EWD THRU KMSP TWD KABR...AND
THIS CDFNT WILL CONTINUE TO PRES SE THRU THE REST OF THE EVE.
BATCH OF -SN THAT PUSHED THROUGH MAINLY WRN AND SRN PORTIONS OF
THE TWIN CITIES REGION HAS SHIFTED OFF TO THE SE SO AM NOT
EXPECTING MUCH MORE OF ANY ACCUMULATING OR VISIBILITY-HAMPERING
SNOWFALL. THE SNOW WILL COME TO AN END OVER THE MPX CWFA BY LATE
EVENING THEN COLDER HIGH PRES WILL SLIDE SE LATE TNGT THRU TMRW.
SKIES WILL PARTIALLY CLEAR OUT...BUT THE MAIN IMPACT WILL BE
STRONGER CAA. AFTER HIGHS THAT RANGED THRU THE 30S THIS AFTN...THE
POST-FRONTAL CAA WILL FORCE LOWS THAT WILL SPAN FROM 10 DEGREES
ABOVE ZERO TO 10 DEGREES BELOW ZERO TONIGHT. THIS WILL THEN BE
FOLLOWED BY HIGHS FROM AROUND 10 TO THE LOWER 20S FOR THU.
THURSDAY NIGHT THROUGH SATURDAY...THE AREA OF HIGH PRES WILL ONLY
BE SHORT-LIVED AS IT SHIFTS OFF TO THE SE THU NIGHT INTO FRI WHILE
A WMFNT NUDGES IN FROM THE W. THIS WILL RESULT IN NOT ONLY A
WARMING TREND FRI INTO FRI NIGHT BUT ALSO THE POTENTIAL FOR SOME
SNOW SHOWERS OR LIGHT SNOW FOR MAINLY NRN AND ERN PORTIONS OF THE
MPX CWFA THU NIGHT THRU SAT AS THE FNT WILL SLOWLY LIFT OUT AND
GIVE WAY TO SEVERAL UPPER LEVEL DISTURBANCES PLUS A TRAILING CDFNT
FOR SAT. POPS ARE NO HIGHER THAN CHC RANGE AND ACCUMULATIONS...IF
ANY...WILL BE MINOR. AS FOR TEMPS...THE SIGNIFICANT WARM-UP FOR
FRI WILL BRING HIGHS AROUND 40 NEAR THE IA BORDER WITH 30S
ELSEWHERE THROUGHOUT THE CWFA. HOWEVER...THE MAIN CDFNT WHICH WILL
BE THE FOCUS FOR A SIGNIFICANT ARCTIC CHILL WILL PUSH THROUGH LATE
SAT SO ALTHOUGH HIGHS WILL DROP OFF ONLY TO THE LOW 20S TO LOW
30S... CAA WILL ABSOLUTELY COMMENCE BY LATE DAY SAT. WINDS WILL
ALSO BE ON THE INCRS DURG THE DAY SAT WITH A TIGHT POST-FRONTAL
PRES GRADIENT AND STRONG JETTING. WIND CHILL VALUES BY LATE DAY
SATURDAY WILL BE IN THE SINGLE DIGITS IN FAR SRN AND ERN
PORTIONS... WHILE NRN AND WRN PORTIONS WILL DROP TO AS LOW AS 20
DEGREES BELOW ZERO.
SATURDAY NIGHT THROUGH TUESDAY...THE ARCTIC BLAST WILL COMMENCE
OVER THE REGION STARTING SAT NIGHT AS A 1040-1050MB HIGH PRES
CENTER FROM NRN CANADA WILL DROP INTO THE NORTH-CENTRAL CONUS. IT
WILL SETTLE OVER THE AREA MON INTO MON NIGHT...MAKING THESE TWO
PERIODS THE COLDEST THIS REGION HAS SEEN IN SOME TIME. BREEZY
CONDITIONS WILL ALSO STILL BE PRESENT WITH THE COLD AIR...SO
COMBINING HIGHS RANGING FROM ZERO TO 10 BELOW ZERO ON MON FOLLOWED
BY LOWS MON NIGHT BETWEEN 10 AND 20 BELOW ZERO WILL MAKE FOR WIND
CHILL VALUES BETWEEN 20 AND 35 DEGREES BELOW ZERO. IT/S LOOKING
MORE AND MORE LIKELY THAT WIND CHILL ADVISORIES/WARNINGS WILL BE
NEEDED. AFTER TEMPS BOTTOM OUT MON NIGHT...THE HIGH PRES CENTER
WILL PUSH OFF TO THE E...ALLOWING A MORE SOUTHERLY FLOW. THIS
WILL ALLOW HIGHS ON TUE TO CLIMB INTO THE SINGLE DIGITS ABOVE
ZERO.
&&
.AVIATION.../06Z TAF ISSUANCE/
MAIN FORECAST CONCERN THIS TAF PERIOD IS THE POTENTIAL FOR MVFR
CIGS TO MOVE INTO THE AREA FROM THE NORTHWEST OVERNIGHT AND
THURSDAY MORNING. 11-3.9 MICRON SATELLITE IMAGERY SHOWS A BLOB OF
LLVL MOISTURE OVER NORTH DAKOTA ALONG THE WESTERN PERIPHERY OF THE
SURFACE RIDGE. BOTH THE HRRR /CLOUDBASE/ AND RAP /925-850MB MOISTURE/ PROGS
SHOW THIS AREA OF MOISTURE BETWEEN 2000 AND 4000 FT ADVECTING INTO
THE MN BETWEEN 08Z AND 12Z...AND WI ON THURSDAY MORNING. WILL
RETAIN A SCT-BKN MVFR LEVEL DECK IN THE TAF ACCORDINGLY. THE 925MB
LAYER IS PROGGED TO DRY OUT THURSDAY AFTERNOON /MN/ AND EARLY EVE
/WI/...BUT QUICKLY BE REPLACED BY A WEST TO EAST SURGE OF
850-700MB MOISTURE BETWEEN 03Z AND 12Z FRIDAY. WILL INTRODUCE SNOW
INTO KAXN AROUND 03Z FRIDAY...BUT ONSET FOR THE REMAINDER OF THE
SITES WILL MOST LIKELY BE BEYOND THIS TAF PERIOD. NORTHWEST WINDS
AT 5 TO 10 KTS WILL PREVAIL THROUGH THE PERIOD.
KMSP...SCT MVFR LEVEL CLOUDS /2000 FT/ WILL BE POSSIBLE AFTER 12Z
THURSDAY...ALONG WITH A BKN VFR DECK /3500 FT/. THE 2KFT DECK
COULD BRIEFLY GO BROKEN ON THURSDAY MORNING...BUT CONFIDENCE IS
NOT HIGH ON THAT. CLEARING ENSUES IN THE AFTERNOON...WITH ANOTHER
ROUND OF CLOUDS /LOW-END VFR CIGS/ ARRIVING AFTER 06Z FRIDAY.
/OUTLOOK FOR KMSP/
FRI...VFR. CHC OF -SN AND MVFR VIS/CIG IN MORNING. WIND SW 5-15
KTS.
SAT...MVFR CIGS LIKELY. AFTERNOON -SN POSSIBLE. W WIND 5 KTS BECOMING NW
15-20 KTS WITH GUSTS TO 30 KTS.
SUN...CHANCE OF -SN WITH MVFR OR LOWER CIG/VIS. WINDS W 5-10 KTS
BECOMING NW 15-20 KTS LATE.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
JPC/LS
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
906 PM MST WED JAN 16 2013
.SHORT TERM...VALID FOR THU AND FRI...
A WEAK COLD FRONT WAS APPROACHING THE FORECAST AREA FROM NE MT/W
N DAKOTA THIS EVENING. MODELS INDICATED SOME WARM ADVECTION
INCREASING OVER THIS BOUNDARY LATER TONIGHT. MOISTURE WAS ALREADY
IN PLACE OVER SE MT PER SATELLITE IMAGERY AND SURFACE
OBSERVATIONS. RAP AND WRF SOUNDINGS SUPPORTED FLURRIES AFTER 06Z
AROUND KBHK. RADAR AND OBSERVATIONS WERE DRY THIS EVENING SO HAVE
REMOVED THE FLURRIES THROUGH 06Z...BUT KEPT THEM GOING OVERNIGHT.
TEMPERATURES WERE IN THE UPPER 20S AND 30S ACROSS THE AREA AT
03Z. MIN TEMPERATURES LOOKED REASONABLE FROM KBIL TO KSHR W...BUT
SEEMED A BIT LOW OVER THE EASTERN ZONES. EVEN THOUGH COLD FRONT
MOVES INTO THE E LATER TONIGHT...AIRMASS WILL NOT BE MUCH COLDER
THAN IT IS CURRENTLY...AND CLOUD COVER WILL LIMIT TEMPERATURE
FALLS. THUS HAVE RAISED THE MINS E OF KBIL.
A TIGHT SURFACE PRESSURE GRADIENT WAS OVER THE AREA W OF KBIL THIS
EVENING. WINDS OVER KLVM AND BIG TIMBER WERE IN THE 20S TO 30S MPH
RANGE. GRADIENT WAS NOT EXPECTED TO TIGHTEN FURTHER OVERNIGHT...SO
WILL NOT NEED A WIND ADVISORY. MODELS DID SHOW THE GRADIENT
STRENGTHENING THU NIGHT...SO WIND HIGHLIGHTS WILL LIKELY BE
NEEDED FOR THIS PERIOD THROUGH AT LEAST FRI. ARTHUR
.LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED...
EXTENDED MODELS REMAIN IN GOOD AGREEMENT THROUGH NEXT
TUESDAY...WITH MAJOR DIFFERENCES APPEARING IN HOW THEY HANDLE A
PACIFIC STORM SYSTEM THAT LOOKS TO IMPACT THE REGION BEGINNING
LATE WEDNESDAY. NORTHWEST FLOW ALOFT WILL CONTINUE OVER THE
FORECAST AREA SATURDAY INTO MONDAY AS MODELS STILL SHOW A DEEP
UPPER LOW SITUATED OVER THE HUDSON BAY AREA AND UPPER LEVEL
RIDGING OVER THE PACIFIC COAST.
MODELS CONTINUE TO SHOW AN ARCTIC FRONT BACKDOORING INTO THE FAR
EASTERN ZONES LATE IN THE DAY SATURDAY OR SATURDAY NIGHT.
HOWEVER...CONFIDENCE IS STILL NOT HIGH AT THIS TIME AS TO THE
TIMING OF THE FRONT NOR HOW FAR WEST IT WILL TRAVEL...ALTHOUGH IT
DOES LOOK TO MAKE IT TO THE BILLINGS AREA. THE COLDEST AIR STILL
LOOKS TO REMAIN FROM ABOUT ROSEBUD COUNTY EASTWARD WITH THE VERY
BITTER COLD AIR REMAINING ACROSS NORTH DAKOTA. DID NOT MAKE ANY
SIGNIFICANT CHANGES TO THE PREVIOUS FORECAST IN REGARDS TO
TEMPERATURES FOR THE WEEKEND. AS FOR PRECIP...THERE STILL REMAINS
THE POSSIBILITY OF SOME LIGHT SNOW ALONG THE FRONT AND IN THE
ARCTIC AIRMASS ITSELF SUNDAY INTO SUNDAY NIGHT. THE ARCTIC AIR
LOOKS TO BE SHORT-LIVED AS MODELS BRING THE UPPER LEVEL RIDGE OVER
THE WEST COAST SLOWLY EASTWARD LATE MONDAY INTO EARLY WEDNESDAY.
AT THE SAME TIME...SURFACE HIGH PRESSURE SOUTHWEST OF THE REGION
COMBINES WITH SHORTWAVES IN NW FLOW TO TIGHTEN THE PRESSURE
GRADIENT ACROSS THE WEST AND ONCE AGAIN INCREASE WINDS IN THE
WESTERN FOOTHILLS. ALTHOUGH IT IS DEEP INTO THE EXTENDED...THE
MODELS HAVE HAD THIS SCENARIO PLAYING OUT FOR SEVERAL CYCLES...SO
CONFIDENCE IS INCREASING IN ANOTHER POTENTIAL HIGH WIND EVENT LATE
MONDAY INTO AT LEAST TUESDAY NIGHT. BECAUSE OF THIS...INCREASED
WIND GUSTS TO ABOUT 45 MPH FROM LIVINGSTON TO BIG TIMBER SOUTH TO
NYE ALONG THE BEARTOOTH FOOTHILLS.
IT DOES LOOK LIKE A WARM UP IS IN STORE MONDAY INTO EARLY
WEDNESDAY AS THE UPPER LEVEL RIDGING MOVES CLOSER...THE DOWNSLOPE
WINDS KICK IN AND THE ARCTIC AIR RETREATS TO THE EAST...SO ABOVE
AVERAGE TEMPS ARE LOOKING MORE LIKELY DURING THAT PERIOD. THE NEXT
PACIFIC SYSTEM MAY IMPACT THE REGION BEGINNING LATE WEDNESDAY.
TIMING AND STRENGTH OF THIS SYSTEM HAVE YET TO BE DETERMINED...SO
I MAINLY JUST TWEAKED POPS IN THE MOUNTAINS AND FOOTHILLS. STC
&&
.AVIATION...
VFR CONDITIONS CAN BE EXPECTED THROUGH THE NIGHT WITH JUST SOME
MID LEVEL CLOUDS WORKING FROM NORTHWEST TO SOUTHEAST ACROSS
SOUTHERN MONTANA AND NORTHERN WYOMING. GUSTY SOUTHWEST WINDS UP TO
30KTS WILL TAKE PLACE AT KLVM. THESE WINDS WILL INCREASE IN
STRENGTH THURSDAY AFTERNOON AND NIGHT. TWH
&&
.PRELIMINARY POINT TEMP/POPS...
THU FRI SAT SUN MON TUE WED
-----------------------------------------------------------
BIL 025/041 031/049 022/036 012/026 008/030 017/037 026/038
00/N 00/N 00/B 03/S 21/B 10/N 01/B
LVM 027/044 028/045 023/039 014/030 011/032 019/036 023/036
00/N 00/N 00/N 02/S 21/N 10/N 02/J
HDN 022/043 020/048 019/034 009/023 006/026 014/036 022/037
00/U 00/N 00/B 13/S 21/B 10/B 01/B
MLS 022/038 020/045 015/024 003/016 904/017 009/029 019/032
00/U 00/B 00/B 13/S 21/B 10/B 01/B
4BQ 021/040 020/046 015/028 006/021 002/021 010/032 018/034
00/U 00/B 00/B 13/S 21/B 10/B 01/B
BHK 020/036 023/040 013/021 001/013 909/013 004/025 016/030
10/B 00/B 00/B 13/S 11/B 11/B 01/B
SHR 018/046 021/051 016/038 011/027 006/030 016/039 021/038
00/U 00/B 00/B 12/S 21/B 10/B 01/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
333 PM CST THU JAN 17 2013
.SHORT TERM...TONIGHT THROUGH SUNDAY
MAIN FORECAST PROBLEM IS TEMPS AND WINDS WITH THE STRONG COLD
FRONT ON SATURDAY AND ANOTHER FRONT SUNDAY/SUNDAY NIGHT.
HOWEVER THE INITIAL ISSUE IS THE PERSISTENT AREA OF FOG AND
STRATUS THAT REMAINED JUST EAST OF OMAHA THROUGHOUT THE DAY...BUT
AFTERNOON VISIBLE LOOP SHOWS THAT AREA IS FINALLY ERODING WITH THE
HELP OF AFTERNOON WARMING AND A WEST COMPONENT TO THE CLOUD TOP
WINDS. AS TO WHETHER OR NOT THIS FOG/STRATUS WILL FORM AGAIN
TONIGHT...WE BELIEVE THE STRENGTHENING WESTERLY 850MB WINDS SHOULD
KEEP THE LAYER MIXED ENOUGH TO PREVENT REFORMING AND SOME WARMING
IN THE LAYER SHOULD HELP AS WELL.
ASSUMING FRIDAY STARTS WITHOUT THE STRATUS DECK...THE WESTERLY
850 WINDS WILL INFLUENCE A FAIRLY QUICK WARM UP THROUGHOUT THE
MORNING AND HIGHS SHOULD REACH THE 50S MOST AREAS. THOSE LOCATIONS
WHERE AN INCH OR MORE OF SNOW REMAINS WILL BE A FEW DEGREES
COOLER...WHICH IS MAINLY WEST AND NORTH OF LINCOLN INTO THE
FREMONT AREA.
ON FRIDAY THE MAIN UPPER JET REMAINS WELL NORTH OF THE FORECAST
AREA... HOWEVER A STRENGTHENING NORTHWEST FLOW JET MAX IS
FORECAST TO BE MOVING THROUGH SOUTHERN ALBERTA/SASKATCHEWAN WHICH
QUICKLY PUSHES ARCTIC AIR SOUTH THROUGH THE PLAINS. MODELS ARE IN
GOOD AGREEMENT WITH THE TIMING AND STRENGTH OF THE COLD FRONTAL
PASSAGE ACROSS OUR AREA SATURDAY. BEFORE THE FRONT MOVES
THROUGH ON SATURDAY...THE AIRMASS WILL AGAIN SUPPORT WARM
TEMPERATURES IN THE 40S BUT SOME CLOUD COVER WILL LIMIT WARMING.
BEHIND THE FRONT NORTHWEST WINDS WILL INCREASE CONSIDERABLY WITH
GUSTS OF 30 MPH AND SHARPLY FALLING TEMPERATURES. THE AIRMASS WILL
REMAIN TOO DRY FOR ANY PRECIPITATION WITH THIS SYSTEM.
BY SUNDAY A 1032+ SURFACE HIGH BUILDS IN WITH HIGHS MOSTLY IN THE
20S. ALSO ON SUNDAY THE UPPER RIDGE ALONG THE WEST COAST IS
PROGGED TO AMPLIFY AND THUS PUSH ANOTHER COLD FRONT THROUGH THE
PLAINS...THIS TIME FOLLOWED BY A STRONGER SURFACE HIGH OF AROUND
1040MB. NAM AND GFS ARE IN FAIR AGREEMENT ON THE TIMING OF THE
SUNDAY FRONT BUT THE 12Z ECMWF IS A BIT SLOWER. EITHER WAY WE WILL
SEE ANOTHER SURGE OF ARCTIC AIR AND COLDER TEMPERATURES. WIND
CHILLS COULD DROP INTO THE MINUS 15 TO MINUS 20 DEGREE RANGE LATE
SUNDAY NIGHT AND MONDAY MORNING ESPECIALLY IN NORTHEAST NEBRASKA.
ONE FACTOR THAT WILL HELP KEEP TEMPERATURES FROM PLUMMETING WELL BELOW
ZERO WITH THESE ARCTIC BLASTS WILL BE THE LACK OF SNOW COVER.
HOWEVER COMPARED TO THE WARM DAYS LEADING UP TO SUNDAY...THE
CHANGE IN TEMPERATURES AND WIND CHILLS WILL SURELY HAVE AN IMPACT
ON THE REGION.
NIETFELD
.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY
MAIN CONCERN CONTINUES TO BE TEMPERATURES THROUGH THE PERIOD.
ARCTIC AIRMASS IS STILL PROGGED TO PUSH INTO THE AREA THIS
WEEKEND...WITH REINFORCING COLD AIR ON SUNDAY NIGHT/MONDAY. CWA
WILL BE ON THE WESTERN FRINGE OF THE COLDEST AIR...AND LACKING IN
SNOWPACK...BUT STILL COULD SEE TEMPS FALL INTO THE SINGLE DIGITS
BELOW TO SINGLE DIGITS ABOVE ZERO...WITH RECOVERY INTO THE LOWER
TEENS TO LOWER 20S ON MONDAY. MODERATING TEMPERATURES WILL THEN
CONTINUE THROUGH AT LEAST WEDNESDAY NIGHT AS UPPER-LEVEL RIDGE MOVES
OVERHEAD AND LOW-LEVEL SOUTHWEST FLOW CONTINUES. BY WEDNESDAY
NIGHT/THURSDAY...ECMWF AND GFS BOTH INDICATE A STORM SYSTEM MOVING
OUT OF THE ROCKIES AND ACROSS THE PLAINS. GFS AND 00Z ECMWF KEPT
PRECIP EAST OF THE CWA...WHILE 12Z ECMWF IS A LITTLE SLOWER AND
DEEPER AND DOES PLACE CWA IN A MORE FAVORABLE LOCATION FOR PRECIP.
FOR NOW...BLENDS WERE DRY AND BELIEVE THAT IS THE WAY TO LEAN UNTIL
MODELS DEVELOP SOME CONSISTENCY WITH THE THURSDAY SYSTEM. COLD AIR
WILL SPILL IN AGAIN BEHIND THE SYSTEM...BEGINNING SOMETIME AROUND
THURSDAY.
MAYES
&&
.AVIATION...
18Z TAFS FOR KOMA...KOFK...KLNK
INITIAL CONCERN WILL BE HOW THE STRATUS WILL AFFECT KOMA NOW THAT
IT IS MOVING OUT OF KLNK AND IS TO THE EAST OF KOFK. THE RAP SEEMS
TO BE HANDLING THE STRATUS THE BEST...ALTHOUGH MAY NOT BE
EXTENSIVE ENOUGH WITH THE WEAK FLOW. IFR CONDITIONS HAVE SPREAD
INTO MLE AND WITH THE LIGHT NORTHEAST DRIFT OF THE DECK...DID
BRING THE DECK IN KOMA THROUGH 00Z. WILL NEED TO MONITOR THIS
AFTERNOON UNTIL EARLY EVENING TO SEE HOW MUCH THE AREA IS ABLE TO
SHRINK DURING THE AFTERNOON.
AFTER 03Z...THE LOW LEVEL JET STRENGTHENS AND HAVE ADDED TO ALL
THREE TAF FORECASTS. THIS SHOULD HINDER ANY LOW CLOUDS
DEVELOPMENT.
ZAPOTOCNY
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1159 AM CST THU JAN 17 2013
.UPDATE...
WILL CONTINUE TO MAKE SHORT TERM UPDATES TO BETTER ACCOUNT FOR
STRATUS AND TEMPERATURES.
&&
.DISCUSSION...
CLOUDS AND TEMPERATURES TO BE QUITE VARIABLE TODAY. UPDATED THE
PUBLIC FORECAST TO LOWER TEMPERATURES WHERE STRATUS AND FOG WILL
HOLD ON LONGER. FLOW IS WEAK...BUT TENDENCY IS TO SHIFT EAST WITH
TIME. LOCATIONS TOWARD ALBION HAVE WARMED QUICKLY INTO THE 40S
WITH A LITTLE BETTER MIXING.
&&
.AVIATION...
18Z TAFS FOR KOMA...KOFK...KLNK
INITIAL CONCERN WILL BE HOW THE STRATUS WILL AFFECT KOMA NOW THAT
IT IS MOVING OUT OF KLNK AND IS TO THE EAST OF KOFK. THE RAP SEEMS
TO BE HANDLING THE STRATUS THE BEST...ALTHOUGH MAY NOT BE
EXTENSIVE ENOUGH WITH THE WEAK FLOW. IFR CONDITIONS HAVE SPREAD
INTO MLE AND WITH THE LIGHT NORTHEAST DRIFT OF THE DECK...DID
BRING THE DECK IN KOMA THROUGH 00Z. WILL NEED TO MONITOR THIS
AFTERNOON UNTIL EARLY EVENING TO SEE HOW MUCH THE AREA IS ABLE TO
SHRINK DURING THE AFTERNOON.
AFTER 03Z...THE LOW LEVEL JET STRENGTHENS AND HAVE ADDED TO ALL
THREE TAF FORECASTS. THIS SHOULD HINDER ANY LOW CLOUDS
DEVELOPMENT.
&&
.PREV DISCUSSION... /ISSUED 156 AM CST THU JAN 17 2013/
DISCUSSION...
IMPENDING DRY ARCTIC BLAST THIS WEEKEND CONTINUES TO BE MAIN ISSUE.
GOING FCST IS IN VERY GOOD SHAPE AND ONLY MINOR TWEAKS NEEDED.
LARGE SCALE FLOW OVER THE NEXT SEVERAL DAYS WILL MAKE POSSIBLE A
DRAMATIC SHIFT IN TEMPERATURES THIS WEEKEND AND EARLY NEXT WEEK.
MODELS IN AGREEMENT AMPLIFYING WRN CONUS UPPER LEVEL RIDGE AND
BROAD LONGWAVE TROF DOWNSTREAM WILL ALLOW THE COLDEST AIR MASS OF
THE SEASON TO DROP OUT OF CANADA AND INTO THE LOWER 48.
MODELS CONTINUE TO ADVERTISE INITIAL THRUST OF CAA WILL BE UNDERWAY
EARLY SAT MORNING IN ASSOCIATION WITH DEEP SFC LOW DROPPING DOWN THRU
THE UPPER MIDWEST. TIME-SECTIONS PRETTY MUCH SHOWING LEADING EDGE OF
THE BNDRY SHOULD BE PASSING THRU THE OMAHA METRO SHORTLY BEFORE AFTN.
SUN NIGHT/MON...REINFORCING SHOT OF INTENSE CAA IS THEN PROGGED TO
DROP INTO THE CNTRL PLAINS. AS USUAL WITH INTENSE THERMAL ADVECTION
MEX AND ECM MOS NUMBERS ARE OFF...AND IN THIS CASE TOO WARM. AT THIS
POINT STILL THINK MONDAY LOWS WILL BOTTOM OUT AROUND 5-10 ABOVE WITH
WIND CHILL INDICES RANGING -10 TO -20 BELOW WHILE HIGHS WILL STRUGGLE
TO REACH THE MID/UPPER TEENS.
FORTUNATELY...THE BITTERLY COLD CONDITIONS WILL BE SHORT LIVED AND
WITH TEMPS REBOUNDING WED/THURS WITH HIGHS GENERALLY IN THE U30S/M40S
AFOREMENTIONED WRN RIDGE BUILDING EAST AND INCREASING THKNS SPREADING
OVER THE PLAINS.
DEE
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
ZAPOTOCNY
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1250 AM EST THU JAN 17 2013
.SYNOPSIS...
THE STORM SYSTEM THAT BROUGHT THE SNOW TO THE AREA TODAY HAS
EXITED OFF OF THE EAST COAST. A COLD FRONT WILL CROSS THE AREA ON
THURSDAY BRINGING SCATTERED SNOW SHOWERS AND DROPPING TEMPERATURES
DURING THE AFTERNOON. BRIEFLY MILDER TEMPERATURES SATURDAY...WILL
BE REPLACED BY MUCH COLDER AIR EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
7 PM UPDATE...
JUST MINOR TWEAKS TO HRLY T/TD GRIDS AT THIS TIME AS THEY APPEAR
TO BE RIGHT ON TARGET. SNOW HAS EXITED THE REGION TO THE EAST WITH
DRY AIR WORKING DOWN WELL INTO THE BL, LEAVING VRY LITTLE CHC FOR
LINGERING FZRA OR FZDZ. THUS POPS HV BEEN DROPPED TO ZERO UNTIL
COLD FRNT INCHES CLOSER. LIGHT SNOW IS OCCURRING ACRS SRN ONTARIO
AND CANADIAN RADARS INDICATE THIS AREA OF PCPN ABOUT READY TO
ENTER OVR LK ONTARIO. 18Z NAM AND LATEST HRRR HAS FAIRLY GOOD
HANDLE ON PCPN LOCATION AND HV USED MODEL BLENDS TO ACCNT FOR
TRENDS DRG THE OVRNGT PD.
TIMING ON FRONT BRINGS IT INTO FINGER LKS REGION BY 12Z WHICH IS
IN LINE WITH THE NAM12. SLGT CHC POPS ENTER INTO EXTRM NRN ZONES
BY 03Z AND SPREAD INTO TWIN TIERS BY 12Z. AS LK MOISTURE IS PICKED
UP, HICHC TO LKLY POPS EXPECTED ARND 12Z AS SATURATED LYR
INCREASES TO NR 800MB AND MEAN FLOW SETTLES OUT ARND 280 DEGREES.
SNOWFALL AMNTS ACRS ONEIDA CNTY THRU 12Z THURSDAY WILL BE ARND 1
INCH.
SKIES HV CLRD ACRS PORTIONS OF THE CWA AS OF 00Z AND WL DROP SOUTH
TONIGHT AS DRY AIR MVS IN BHND SYSTEM AND AHD OF APPCHG FRONTAL
BNDRY. THUS HV UPDATED SKY GRIDS TO ACCNT FOR THIS TREND AND MAY
IMPACT AMNT OF TEMP DROP WITH SNOWPACK IN PLACE ONCE AGAIN.
PREV DISCO BLO...
3 PM UPDATE...
LINGERING LIGHT PRECIP WILL MOVE OUT BY 7 PM. WITH LOW LEVEL
SATURATION NOT GOING INTO THE DENDRITE ZONE, FREEZING RAIN AND
FREEZING DRIZZLE IS POSSIBLE.
DRIER AIR WILL MOVE IN SLOWLY FROM THE WEST. THE BACK EDGE NOW
FROM FZY TO DSV. QUIET THIS EVENING BEFORE A COLD FRONT DROPS SE
THROUGH THE CWA LATE TONIGHT AND THU MORNING. SOME MOISTURE BUT
SNOW SHOWERS WILL BE LIGHT. 6 HOUR SNOWFALL AMOUNTS UNDER AN INCH.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY/...
3 PM UPDATE...
WITH THE COLD FRONT THURSDAY HIGHS WILL BE IN THE MORNING WITH
CENT NY DROPPING IN THE AFTN. LAKE EFFECT WILL KICK IN BUT SHOULD
REMAIN WEAK INTO FRIDAY. SHEAR IS HIGH. THE SATURATED LEVEL IS
ONLY TO 5K TO START THEN LIFTS TO 7 THU NGT. A SHALLOW DENDRITE
ZONE AT THE TOP OF THE SATURATED LAYER WILL ALSO LIMIT SNOWFALL
THU. THU NGT LAKE EFFECT SHOULD BE BETTER BUT NW FLOW WILL MEAN
MULTIBANDS AND NO LAKE HURON CONNECTION. COLDER WITH BETTER
MOISTURE. THE COLDER AIR BRINGS THE DENDRITE ZONE DOWN SOLIDLY IN
THE DENDRITE ZONE. STILL A LOT OF SHEAR WITH HARDLY ANY SFC TO 2K
WINDS.
FRI AFTN INTO SAT THE LOW LEVEL WINDS SHIFT TO WEST SENDING THE
LAKE EFFECT INTO JUST ONEIDA. WAA STARTS KILLING THE LAKE EFFECT
FRI NGT, BUT NOT SOON ENOUGH TO GET FRI HIGH TEMPS ABOVE FREEZING.
HIGH PRESSURE SLIDES EAST FROM THE OHIO VALLEY FRI INTO THE
CAROLINAS FRI NGT.
A WARM FRONT AHEAD OF A SFC LOW MOVING EAST IN SE CANADA WILL
BRING SNOW SHOWERS ALONG THE LAKE SHORE LATE FRI AND FRI EVE. LOW
LEVEL FLOW CONTINUES OUT OF THE W AND SW SATURDAY SO MOST OF THE
CWA WILL BE DRY. WITH 850MB TEMPS APPROACHING ZERO HIGH TEMPS WILL
RISE INTO THE U30S AND L40S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
230 PM WED UPDATE...
HIGH CONFIDENCE IN AN ARCTIC SHIFT TO THE WEATHER PATTERN WITH
PERHAPS THE COLDEST AIR OF THE SEASON EN ROUTE. GFS AND ECMWF
AGREE ON 1000-500MB THICKNESSES DIPPING IN THE 490S FOR AT LEAST
CENTRAL NY AND CLOSE TO IT FOR NORTHEAST PA BY 12Z TUESDAY. THIS
BEGINS WITH INITIAL MOISTURE-LIMITED COLD FRONT PASSING THROUGH
EARLY SUNDAY WITH SOME SCATTERED SNOW SHOWERS...BRINGING
TEMPERATURES BACK TO NEAR NORMAL. ARCTIC FRONT THEN DROPS THROUGH
MONDAY TO SEND TEMPERATURES WELL BELOW CLIMATOLOGY EARLY NEXT WEEK.
LAKE EFFECT DETAILS AND PRESENCE OF CLIPPER-LIKE SYSTEMS WITHIN
BRISK UPPER FLOW HAVE YET TO BE SORTED OUT...YET VERY DRY AIR MASS
OVERALL...SO FOR NOW WENT ALONG WITH HPC POPS GENERALLY IN SLIGHT
TO LOW CHANCE RANGE /POPS HIGHEST WITH ARCTIC FRONT MONDAY IN
30-50 PCT RANGE/. WITH 850MB TEMPERATURES PUSHING AROUND MINUS-20
CELSIUS BY TUESDAY...JUST ABOUT ANY PASSING CLOUD WILL AT LEAST
PRODUCE LIGHT SCATTERED FLURRIES WITH ABOUT THE SAME WATER CONTENT
AS STYROFOAM.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
ARCTIC FNT WILL DROP THRU THE AREA AFT 12Z AND TRIGGER SOME SNOW
SHWRS WITH A BRIEF PD OF LE BHD THE FNT. THIS WILL DROP CIGS AND
VSBYS INTO THE MVFR RANGE MOST STATIONS...WITH SOME BRIEF IFR
CONDS PSBL. WLY WINDS HAD OF THE FNT WILL BECOME NLY BHD THE
FNT...THEN BECOME LGT AFT 00Z AS HIPRES BLDS IN.
.OUTLOOK...
THU NGT THRU FRI...MAINLY MVFR CIGS AND SOME SCT -SHSN IN CNTRL
NY...VFR AVP.
FRI NGT/SAT...MAINLY VFR.
SAT NGT THRU MON...MVFR/IFR IN SNOW SHOWERS...ESPECIALLY CNTRL NY.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MDP/PVN
NEAR TERM...PVN/TAC
SHORT TERM...TAC
LONG TERM...MDP
AVIATION...DGM/DJP
AREA FORECAST DISCUSSION
NWS RALEIGH NC
255 PM EST THU JAN 17 2013
.SYNOPSIS...
STRENGTHENING LOW PRESSURE OVER UPSTATE SOUTH CAROLINA WILL TRACK TO
THE EAST NORTHEAST ACROSS SOUTHEAST NORTH CAROLINA THIS EVENING...
THEN OFF THE COAST LATE TONIGHT. COLD HIGH PRESSURE WILL BUILD IN
FROM THE WEST FRIDAY INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 150 PM THURSDAY...
THROUGH TONIGHT: CONFIDENCE REMAINS HIGH IN THE OCCURRENCE OF
SIGNIFICANT BANDED SNOWFALL OVER NRN AND WRN PORTIONS OF NC EARLY
THIS EVENING THROUGH TONIGHT.
INTENSIFYING SURFACE LOW PRESSURE... LOCATED OVER NE GA EARLY THIS
AFTERNOON... WILL CONTINUE A STEADY ENE TRACK ALONG A FRONTAL ZONE
ACROSS SE NC. THE NAM/GFS/RAP/SREF MEAN HAVE EXHIBITED EXCELLENT
CONTINUITY THE LAST SEVERAL RUNS REGARDING TRACK AND TIMING... AND
HAVE SHOWN A VERY SMALL SOUTHWARD TREND IN THE EXTENT OF COLDER AIR.
DYNAMIC LIFT WITH THIS SYSTEM WILL BE EXTREMELY STRONG -- ESPECIALLY
ALOFT WITH HIGH OMEGA FOCUSED IN THE CRUCIAL -12C TO -20C LAYER
ALOFT -- BUT QUICK-HITTING. AN INTENSE UPPER DIVERGENCE MAX EXPECTED
TO BE ROUGHLY OVER THE SRN NC FOOTHILLS AT 00Z WILL MOVE NE THROUGH
CENTRAL NC BEFORE EXITING NE SECTIONS OF THE CWA BY AROUND 07Z. THIS
IS IN TANDEM WITH THE PASSAGE OF STRONG Q-VECTOR CONVERGENCE... MID
LEVEL DCVA AND A RISE/FALL COUPLET OF AROUND +/- 200 METERS...
STRONG LOW LEVEL THETA-E ADVECTION... AND DEEP MOIST ISENTROPIC
UPGLIDE. THE FACT THAT THIS SYSTEM IS STRENGTHENING QUICKLY UPON
ARRIVAL IS ESPECIALLY TROUBLING IN THAT THE RESULTANT RAPID MASS
FIELD ADJUSTMENTS ARE LIABLE TO SIGNIFICANT AND QUICKLY BOLSTER
ASCENT AND HEIGHTEN THE EXTENT AND INTENSITY OF THE SNOW BANDING.
MOISTURE AVAILABILITY WILL GENERALLY NOT BE A PROBLEM WITH VERY HIGH
PW (OVER 200 PERCENT OF NORMAL) AND A STRONG MOISTURE TRANSPORT FROM
THE GULF... ALTHOUGH THE INCOMING DRY SLOT ON THE SE SIDE OF THE LOW
WILL BE WORTH MONITORING AND MAY LIMIT WINTRY TOTALS IN THE
SOUTHEAST CWA (SEE BELOW). HOW FAST THE COLD AIR ARRIVES ESPECIALLY
ALOFT REMAINS A CONCERN... ALTHOUGH THE MODELS INITIALIZED WELL AND
ARE IN VERY GOOD AGREEMENT... BOOSTING CONFIDENCE IN THEIR TIMING OF
THE ANTICIPATED THERMAL CHANGES.
THE HEAVIEST SNOW BANDING IS LIKELY TO OCCUR OVER THE WRN AND NRN
PIEDMONT... FROM HIGH ROCK AND BADIN LAKES... ACROSS THE I-40 AND
HIGHWAY 64 CORRIDORS BETWEEN (AND INCLUDING) THE TRIAD AND THE
TRIANGLE... UP TO KERR LAKE AND LAKE GASTON... VERY ROUGHLY
FOLLOWING THE I-85 CORRIDOR TO THE NW... ALIGNED WITH THE AREA OF
STRONGEST DEFORMATION ALOFT. KEY TIMING STILL LOOKS TO BE FROM 23Z
UNTIL AROUND 07Z WITH A QUICK EXIT SOON THEREAFTER. SREF
PROBABILITIES HAVE BEEN VERY CONSISTENT IN SHOWING A 70+ PERCENT
CHANCE OF SNOWFALL RATES OVER ONE INCH PER HOUR ACROSS MUCH OF THE
PIEDMONT AND FAR NRN COASTAL PLAIN FROM MID EVENING UNTIL THE EARLY
OVERNIGHT HOURS. WITH THESE RATES AND THE TIMING OF A FEW HOURS OF
HEAVY BANDED SNOW (STARTING AS A RAIN/SNOW MIX)... STORM TOTAL
ACCUMULATIONS OF 2-4 INCHES IN THIS AREA WITH ISOLATED 5 INCH TOTALS
LOOK QUITE REASONABLE. BORDERING THE WARNING AREA... STILL EXPECT AN
INCH OR SO OF ACCUMULATION MAINLY ON GRASSY AREAS... WITH A LITTLE
SLUSH ON ROADS POSSIBLE.
SOUTH AND EAST OF HERE... INCLUDING FAYETTEVILLE AND CLINTON... A
QUICK BURST OF MAINLY SNOW IS POSSIBLE WITH STRONG DYNAMIC COOLING
THROUGH THE COLUMN AS THE LOW ALOFT PASSES BY... BUT THE WINDOW OF
OPPORTUNITY WILL BE VERY SHORT AS AMOUNTS/DURATION WILL BE GREATLY
LIMITED BY THE MID-UPPER LEVEL DRY SLOT ARRIVAL WITH NOTABLE DRYING
ABOVE THE -5C LEVEL... SUPPRESSING CRYSTAL GROWTH ALOFT... PLUS
BOUNDARY LAYER TEMPS SHOULD HOLD ABOVE FREEZING FOR MUCH OF THIS
EVENT... NOT DROPPING TO NEAR FREEZING UNTIL PRECIP IS NEARLY GONE.
EXPECT LIGHT ACCUMULATIONS OF A DUSTING CONFINED TO GRASSY AREAS.
A SIDE NOTE: MID LEVEL LAPSE RATE PROGS ARE QUITE INTERESTING...
INCLUDING THE 12 KM NAM WHICH INDICATES 850-500 MB VALUES OF 5.5-6.0
C/KM TRAVERSING THE CWA... JUST WNW OF THE 850 MB LOW TRACK...
PRIMARILY BETWEEN 03Z AND 06Z. AND RECENT RAP RUNS TAKE THE 700-400
MB LAPSE RATES (WHICH CAPTURES THE MIXED PHASE REGION ALOFT) UP TO
7.0 C/KM OVER THE NW PIEDMONT TOWARD MIDNIGHT. CONSIDERING THIS
POSSIBILITY FOR UPRIGHT INSTABILITY COMBINED WITH VIGOROUS DYNAMIC
LIFT... A FEW LIGHTNING STRIKES WITHIN SNOW BANDS ARE CERTAINLY
POSSIBLE... ALTHOUGH LIKELY TOO ISOLATED TO INCLUDE IN THE FORECAST
AT THIS TIME.
STRENGTHENING WINDS WILL BE AN ISSUE AS WELL WITH THE TIGHTENING
MSLP GRADIENT AS THE LOW APPROACHES. WE ARE ALREADY SEEING FREQUENT
GUSTS TO 25-40 KTS (ALTHOUGH SOME OF THIS MAY BE AUGMENTED BY A
POSSIBLE GRAVITY WAVE). EXPECT A PERIOD OF SUSTAINED WINDS OF 15-25
MPH WITH SPORADIC GUSTS TO AROUND 30 MPH FROM LATE AFTERNOON UNTIL
AROUND 1-2 AM.
TEMPS SHOULD STEADILY DROP THROUGH THE REST OF THE AFTERNOON AND
NIGHT.
FOR FRIDAY: EXPECT GENERALLY CLEAR SKIES BY DAYBREAK AS THE STORM
DEPARTS QUICKLY WITH CHILLY HIGH PRESSURE BUILDING IN FROM THE WEST.
FORECAST SOUNDINGS AND UPSTREAM CONDITIONS SUGGEST THAT TEMPS SHOULD
STRUGGLE TO RISE TOMORROW WITH STRONG COLD AIR ADVECTION IN THE
MORNING... AND THICKNESSES THAT HOLD AT OR BELOW 1305 METERS ALL DAY
(AND THIS IS EVEN TAKING INTO ACCOUNT THE SHALLOW MIXING AND THAT
THIS LAYER ENCOMPASSES THE SUBSIDENCE INVERSION ALOFT). HAVE BUMPED
HIGHS DOWN TO 36-45. WINDS SHOULD DIMINISH DURING THE AFTERNOON. -GIH
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/...
AS OF 240 PM THURSDAY...
A 1032MB HIGH PRESSURE WILL SETTLE OVERHEAD FRIDAY NIGHT...ALLOWING
FOR GOOD RADIATIONAL COOLING UNDER CLEAR SKIES. THERE MAY BE SOME
SHADED AREAS WHERE SNOW COVER IS ABLE TO LINGER THROUGH THE DAY
FRIDAY...WHICH MAY HELP RADIATIONAL COOLING IN A FEW SPOTS...BUT
OVERALL GUIDANCE SUPPORTS LOWS IN THE MID 20S. THE UPPER LEVEL FLOW
WILL REMAIN RELATIVELY FLAT SATURDAY WHILE THE SURFACE HIGH SHIFTS
SLIGHTLY SOUTHWARD. THE SHALLOW COOLER AIRMASS WILL ONLY SLIGHTLY
MODIFY WITH WEAK VERTICAL MIXING...LEADING TO HIGHS IN THE MID 40S
TO LOWER 50S. LOWS SATURDAY NIGHT IN THE UPPER 20S TO LOWER 30S
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 240 PM THURSDAY...
THE UPPER LEVEL PATTERN WILL BEGIN A SLOW AMPLIFICATION SUNDAY AS
RIDGING BUILDS OUT WEST AND A DEEP TROUGH DEVELOPS OVER THE EASTERN
US. A COLD NORTHWESTERLY FLOW WILL PERSIST THROUGH MIDWEEK... A
COUPLE REINFORCING SHOTS OF ARCTIC AIR VIA DRY COLD FRONTS AS
SHORTWAVES ROTATE SOUTHEAST OUT OF CANADA AND INTO THE BASE OF THE
TROUGH. HIGHS AROUND NORMAL SUNDAY WILL FALL IN TO THE 40S
MONDAY....AND THEN A MORE SIZABLE DROP TUESDAY AND THICKNESSES CRASH
TO NEAR OR BELOW 1260M TUESDAY MORNING. BASED ON THESE
THICKNESSES...LOWS COULD BE IN THE TEENS AND HIGHS IN THE LOW TO MID
30S. MODELS HAVE ONLY RECENTLY COME INTO BETTER AGREEMENT ON THESE
THICKNESSES...AND THE LACK OF SNOW COVER OVER THE MIDWEST LEADS TO
LOWER CONFIDENCE IN TEMPS BEING ON THE COLDER SIDE OF WHAT HAS
HISTORICALLY BEEN OBSERVED. DURING THIS PERIOD...ALL CYCLOGENESIS
ASSOCIATED WITH SHORTWAVES IN THE NORTHWEST FLOW ALOFT SHOULD STAY
WELL OFFSHORE...WITH THE ONLY SENSIBLE IMPACT WILL BE POSSIBLE
OROGRAPHIC CIRRUS MONDAY NIGHT OR TUESDAY NIGHT. BY THE END OF THE
PERIOD...MODELS INDICATE THE WEST COAST RIDGE MAY WEAKEN AND ALLOW
ENERGY TO CROSS INTO THE CENTRAL US AND BRING A BETTER CHANCE OF
PRECIP LATE NEXT WEEK INTO THE WEEKEND.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 1250 PM THURSDAY...
24 HOUR TAF PERIOD:
LIGHT TO MODERATE RAIN WILL CONTINUE OVER THE WRN HALF OF THE AREA
AND SLOWLY MOVE EAST THIS EVENING AS THE SURFACE LOW TRACKS NE INTO
CENTRAL NC. HIGH CONFIDENCE THAT IFR AND LIFR AVIATION CONDITIONS
WILL CONTINUE THROUGH APPROX 12Z FRIDAY. RAIN WILL CHANGE TO SNOW
FROM WEST TO EAST...WITH SOME UNCERTAINTY ON THE EXACT TIMING OF THE
CHANGE OVER. FOR NOW HAVE SNOW STARTING AROUND 23Z AT KINT AND KGSO
TO 02-04Z AT KRDU AND KRWI...WITH THE CHANCE FOR A BRIEF PERIOD OF
SNOW AT KFAY AROUND 05Z FRIDAY. SNOW AND FOG WILL KEEP LIFR
CONDITIONS IN PLACE THROUGH 05Z-06Z. RESIDUAL LOW LEVEL MOISTURE MAY
KEEP VISBYS LOW EVEN AFTER THE SNOW ENDS. AVIATION CONDITIONS SHOULD
IMPROVE TO VFR AROUND SUNRISE. NNE WINDS AROUND 10-20 KTS THIS
EVENING WILL SHIFT TO THE NW AS THE FRONT MOVES THROUGH CENTRAL NC
OVERNIGHT.
LOOKING AHEAD:
VFR CONDITIONS EXPECTED FRIDAY NIGHT THROUGH TUESDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 4 AM EST FRIDAY
FOR NC028-042-043-077-078-083-084.
WINTER STORM WARNING FROM 6 PM THIS EVENING TO 4 AM EST FRIDAY FOR
NCZ007>011-021>027-038>041-073>076.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...SMITH
LONG TERM...SMITH
AVIATION...WSS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
240 PM EST THU JAN 17 2013
.SYNOPSIS...
STRENGTHENING LOW PRESSURE OVER NORTHERN GEORGIA WILL TRACK TO THE
EAST NORTHEAST ACROSS SOUTHEAST NORTH CAROLINA THIS EVENING... THEN
OFF THE COAST LATE TONIGHT. COLD HIGH PRESSURE WILL BUILD IN FROM
THE WEST FRIDAY INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 150 PM THURSDAY...
THROUGH TONIGHT: CONFIDENCE REMAINS HIGH IN THE OCCURRENCE OF
SIGNIFICANT BANDED SNOWFALL OVER NRN AND WRN PORTIONS OF NC EARLY
THIS EVENING THROUGH TONIGHT.
INTENSIFYING SURFACE LOW PRESSURE... LOCATED OVER NE GA EARLY THIS
AFTERNOON... WILL CONTINUE A STEADY ENE TRACK ALONG A FRONTAL ZONE
ACROSS SE NC. THE NAM/GFS/RAP/SREF MEAN HAVE EXHIBITED EXCELLENT
CONTINUITY THE LAST SEVERAL RUNS REGARDING TRACK AND TIMING... AND
HAVE SHOWN A VERY SMALL SOUTHWARD TREND IN THE EXTENT OF COLDER AIR.
DYNAMIC LIFT WITH THIS SYSTEM WILL BE EXTREMELY STRONG -- ESPECIALLY
ALOFT WITH HIGH OMEGA FOCUSED IN THE CRUCIAL -12C TO -20C LAYER
ALOFT -- BUT QUICK-HITTING. AN INTENSE UPPER DIVERGENCE MAX EXPECTED
TO BE ROUGHLY OVER THE SRN NC FOOTHILLS AT 00Z WILL MOVE NE THROUGH
CENTRAL NC BEFORE EXITING NE SECTIONS OF THE CWA BY AROUND 07Z. THIS
IS IN TANDEM WITH THE PASSAGE OF STRONG Q-VECTOR CONVERGENCE... MID
LEVEL DCVA AND A RISE/FALL COUPLET OF AROUND +/- 200 METERS...
STRONG LOW LEVEL THETA-E ADVECTION... AND DEEP MOIST ISENTROPIC
UPGLIDE. THE FACT THAT THIS SYSTEM IS STRENGTHENING QUICKLY UPON
ARRIVAL IS ESPECIALLY TROUBLING IN THAT THE RESULTANT RAPID MASS
FIELD ADJUSTMENTS ARE LIABLE TO SIGNIFICANT AND QUICKLY BOLSTER
ASCENT AND HEIGHTEN THE EXTENT AND INTENSITY OF THE SNOW BANDING.
MOISTURE AVAILABILITY WILL GENERALLY NOT BE A PROBLEM WITH VERY HIGH
PW (OVER 200 PERCENT OF NORMAL) AND A STRONG MOISTURE TRANSPORT FROM
THE GULF... ALTHOUGH THE INCOMING DRY SLOT ON THE SE SIDE OF THE LOW
WILL BE WORTH MONITORING AND MAY LIMIT WINTRY TOTALS IN THE
SOUTHEAST CWA (SEE BELOW). HOW FAST THE COLD AIR ARRIVES ESPECIALLY
ALOFT REMAINS A CONCERN... ALTHOUGH THE MODELS INITIALIZED WELL AND
ARE IN VERY GOOD AGREEMENT... BOOSTING CONFIDENCE IN THEIR TIMING OF
THE ANTICIPATED THERMAL CHANGES.
THE HEAVIEST SNOW BANDING IS LIKELY TO OCCUR OVER THE WRN AND NRN
PIEDMONT... FROM HIGH ROCK AND BADIN LAKES... ACROSS THE I-40 AND
HIGHWAY 64 CORRIDORS BETWEEN (AND INCLUDING) THE TRIAD AND THE
TRIANGLE... UP TO KERR LAKE AND LAKE GASTON... VERY ROUGHLY
FOLLOWING THE I-85 CORRIDOR TO THE NW... ALIGNED WITH THE AREA OF
STRONGEST DEFORMATION ALOFT. KEY TIMING STILL LOOKS TO BE FROM 23Z
UNTIL AROUND 07Z WITH A QUICK EXIT SOON THEREAFTER. SREF
PROBABILITIES HAVE BEEN VERY CONSISTENT IN SHOWING A 70+ PERCENT
CHANCE OF SNOWFALL RATES OVER ONE INCH PER HOUR ACROSS MUCH OF THE
PIEDMONT AND FAR NRN COASTAL PLAIN FROM MID EVENING UNTIL THE EARLY
OVERNIGHT HOURS. WITH THESE RATES AND THE TIMING OF A FEW HOURS OF
HEAVY BANDED SNOW (STARTING AS A RAIN/SNOW MIX)... STORM TOTAL
ACCUMULATIONS OF 2-4 INCHES IN THIS AREA WITH ISOLATED 5 INCH TOTALS
LOOK QUITE REASONABLE. BORDERING THE WARNING AREA... STILL EXPECT AN
INCH OR SO OF ACCUMULATION MAINLY ON GRASSY AREAS... WITH A LITTLE
SLUSH ON ROADS POSSIBLE.
SOUTH AND EAST OF HERE... INCLUDING FAYETTEVILLE AND CLINTON... A
QUICK BURST OF MAINLY SNOW IS POSSIBLE WITH STRONG DYNAMIC COOLING
THROUGH THE COLUMN AS THE LOW ALOFT PASSES BY... BUT THE WINDOW OF
OPPORTUNITY WILL BE VERY SHORT AS AMOUNTS/DURATION WILL BE GREATLY
LIMITED BY THE MID-UPPER LEVEL DRY SLOT ARRIVAL WITH NOTABLE DRYING
ABOVE THE -5C LEVEL... SUPPRESSING CRYSTAL GROWTH ALOFT... PLUS
BOUNDARY LAYER TEMPS SHOULD HOLD ABOVE FREEZING FOR MUCH OF THIS
EVENT... NOT DROPPING TO NEAR FREEZING UNTIL PRECIP IS NEARLY GONE.
EXPECT LIGHT ACCUMULATIONS OF A DUSTING CONFINED TO GRASSY AREAS.
A SIDE NOTE: MID LEVEL LAPSE RATE PROGS ARE QUITE INTERESTING...
INCLUDING THE 12 KM NAM WHICH INDICATES 850-500 MB VALUES OF 5.5-6.0
C/KM TRAVERSING THE CWA... JUST WNW OF THE 850 MB LOW TRACK...
PRIMARILY BETWEEN 03Z AND 06Z. AND RECENT RAP RUNS TAKE THE 700-400
MB LAPSE RATES (WHICH CAPTURES THE MIXED PHASE REGION ALOFT) UP TO
7.0 C/KM OVER THE NW PIEDMONT TOWARD MIDNIGHT. CONSIDERING THIS
POSSIBILITY FOR UPRIGHT INSTABILITY COMBINED WITH VIGOROUS DYNAMIC
LIFT... A FEW LIGHTNING STRIKES WITHIN SNOW BANDS ARE CERTAINLY
POSSIBLE... ALTHOUGH LIKELY TOO ISOLATED TO INCLUDE IN THE FORECAST
AT THIS TIME.
STRENGTHENING WINDS WILL BE AN ISSUE AS WELL WITH THE TIGHTENING
MSLP GRADIENT AS THE LOW APPROACHES. WE ARE ALREADY SEEING FREQUENT
GUSTS TO 25-40 KTS (ALTHOUGH SOME OF THIS MAY BE AUGMENTED BY A
POSSIBLE GRAVITY WAVE). EXPECT A PERIOD OF SUSTAINED WINDS OF 15-25
MPH WITH SPORADIC GUSTS TO AROUND 30 MPH FROM LATE AFTERNOON UNTIL
AROUND 1-2 AM.
TEMPS SHOULD STEADILY DROP THROUGH THE REST OF THE AFTERNOON AND
NIGHT. -GIH
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/...
AS OF 240 PM THURSDAY...
A 1032MB HIGH PRESSURE WILL SETTLE OVERHEAD FRIDAY NIGHT...ALLOWING
FOR GOOD RADIATIONAL COOLING UNDER CLEAR SKIES. THERE MAY BE SOME
SHADED AREAS WHERE SNOW COVER IS ABLE TO LINGER THROUGH THE DAY
FRIDAY...WHICH MAY HELP RADIATIONAL COOLING IN A FEW SPOTS...BUT
OVERALL GUIDANCE SUPPORTS LOWS IN THE MID 20S. THE UPPER LEVEL FLOW
WILL REMAIN RELATIVELY FLAT SATURDAY WHILE THE SURFACE HIGH SHIFTS
SLIGHTLY SOUTHWARD. THE SHALLOW COOLER AIRMASS WILL ONLY SLIGHTLY
MODIFY WITH WEAK VERTICAL MIXING...LEADING TO HIGHS IN THE MID 40S
TO LOWER 50S. LOWS SATURDAY NIGHT IN THE UPPER 20S TO LOWER 30S
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 240 PM THURSDAY...
THE UPPER LEVEL PATTERN WILL BEGIN A SLOW AMPLIFICATION SUNDAY AS
RIDGING BUILDS OUT WEST AND A DEEP TROUGH DEVELOPS OVER THE EASTERN
US. A COLD NORTHWESTERLY FLOW WILL PERSIST THROUGH MIDWEEK... A
COUPLE REINFORCING SHOTS OF ARCTIC AIR VIA DRY COLD FRONTS AS
SHORTWAVES ROTATE SOUTHEAST OUT OF CANADA AND INTO THE BASE OF THE
TROUGH. HIGHS AROUND NORMAL SUNDAY WILL FALL IN TO THE 40S
MONDAY....AND THEN A MORE SIZABLE DROP TUESDAY AND THICKNESSES CRASH
TO NEAR OR BELOW 1260M TUESDAY MORNING. BASED ON THESE
THICKNESSES...LOWS COULD BE IN THE TEENS AND HIGHS IN THE LOW TO MID
30S. MODELS HAVE ONLY RECENTLY COME INTO BETTER AGREEMENT ON THESE
THICKNESSES...AND THE LACK OF SNOW COVER OVER THE MIDWEST LEADS TO
LOWER CONFIDENCE IN TEMPS BEING ON THE COLDER SIDE OF WHAT HAS
HISTORICALLY BEEN OBSERVED. DURING THIS PERIOD...ALL CYCLOGENESIS
ASSOCIATED WITH SHORTWAVES IN THE NORTHWEST FLOW ALOFT SHOULD STAY
WELL OFFSHORE...WITH THE ONLY SENSIBLE IMPACT WILL BE POSSIBLE
OROGRAPHIC CIRRUS MONDAY NIGHT OR TUESDAY NIGHT. BY THE END OF THE
PERIOD...MODELS INDICATE THE WEST COAST RIDGE MAY WEAKEN AND ALLOW
ENERGY TO CROSS INTO THE CENTRAL US AND BRING A BETTER CHANCE OF
PRECIP LATE NEXT WEEK INTO THE WEEKEND.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 1250 PM THURSDAY...
24 HOUR TAF PERIOD:
LIGHT TO MODERATE RAIN WILL CONTINUE OVER THE WRN HALF OF THE AREA
AND SLOWLY MOVE EAST THIS EVENING AS THE SURFACE LOW TRACKS NE INTO
CENTRAL NC. HIGH CONFIDENCE THAT IFR AND LIFR AVIATION CONDITIONS
WILL CONTINUE THROUGH APPROX 12Z FRIDAY. RAIN WILL CHANGE TO SNOW
FROM WEST TO EAST...WITH SOME UNCERTAINTY ON THE EXACT TIMING OF THE
CHANGE OVER. FOR NOW HAVE SNOW STARTING AROUND 23Z AT KINT AND KGSO
TO 02-04Z AT KRDU AND KRWI...WITH THE CHANCE FOR A BRIEF PERIOD OF
SNOW AT KFAY AROUND 05Z FRIDAY. SNOW AND FOG WILL KEEP LIFR
CONDITIONS IN PLACE THROUGH 05Z-06Z. RESIDUAL LOW LEVEL MOISTURE MAY
KEEP VISBYS LOW EVEN AFTER THE SNOW ENDS. AVIATION CONDITIONS SHOULD
IMPROVE TO VFR AROUND SUNRISE. NNE WINDS AROUND 10-20 KTS THIS
EVENING WILL SHIFT TO THE NW AS THE FRONT MOVES THROUGH CENTRAL NC
OVERNIGHT.
LOOKING AHEAD:
VFR CONDITIONS EXPECTED FRIDAY NIGHT THROUGH TUESDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 4 AM EST FRIDAY
FOR NC028-042-043-077-078-083-084.
WINTER STORM WARNING FROM 6 PM THIS EVENING TO 4 AM EST FRIDAY FOR
NCZ007>011-021>027-038>041-073>076.
&&
$$
SYNOPSIS...HARTFIELD/KC
NEAR TERM...HARTFIELD
SHORT TERM...SMITH
LONG TERM...SMITH
AVIATION...WSS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
152 PM EST THU JAN 17 2013
.SYNOPSIS...
STRENGTHENING LOW PRESSURE OVER NORTHEEAST GEORGIA THIS AFTERNOON
WILL TRACK TO THE EAST NORTHEAST ACROSS SOUTHEAST NORTH CAROLINA
THIS EVENING THROUGH MIDNIGHT... THEN OFF THE COAST LATE TONIGHT.
COLD HIGH PRESSURE WILL BUILD IN FROM THE WEST FRIDAY INTO THE
WEEKEND.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 150 PM THURSDAY...
THROUGH TONIGHT: CONFIDENCE REMAINS HIGH IN THE OCCURRENCE OF
SIGNIFICANT BANDED SNOWFALL OVER NRN AND WRN PORTIONS OF NC EARLY
THIS EVENING THROUGH TONIGHT.
INTENSIFYING SURFACE LOW PRESSURE... LOCATED OVER NE GA EARLY THIS
AFTERNOON... WILL CONTINUE A STEADY ENE TRACK ALONG A FRONTAL ZONE
ACROSS SE NC. THE NAM/GFS/RAP/SREF MEAN HAVE EXHIBITED EXCELLENT
CONTINUITY THE LAST SEVERAL RUNS REGARDING TRACK AND TIMING... AND
HAVE SHOWN A VERY SMALL SOUTHWARD TREND IN THE EXTENT OF COLDER AIR.
DYNAMIC LIFT WITH THIS SYSTEM WILL BE EXTREMELY STRONG -- ESPECIALLY
ALOFT WITH HIGH OMEGA FOCUSED IN THE CRUCIAL -12C TO -20C LAYER
ALOFT -- BUT QUICK-HITTING. AN INTENSE UPPER DIVERGENCE MAX EXPECTED
TO BE ROUGHLY OVER THE SRN NC FOOTHILLS AT 00Z WILL MOVE NE THROUGH
CENTRAL NC BEFORE EXITING NE SECTIONS OF THE CWA BY AROUND 07Z. THIS
IS IN TANDEM WITH THE PASSAGE OF STRONG Q-VECTOR CONVERGENCE... MID
LEVEL DCVA AND A RISE/FALL COUPLET OF AROUND +/- 200 METERS...
STRONG LOW LEVEL THETA-E ADVECTION... AND DEEP MOIST ISENTROPIC
UPGLIDE. THE FACT THAT THIS SYSTEM IS STRENGTHENING QUICKLY UPON
ARRIVAL IS ESPECIALLY TROUBLING IN THAT THE RESULTANT RAPID MASS
FIELD ADJUSTMENTS ARE LIABLE TO SIGNIFICANT AND QUICKLY BOLSTER
ASCENT AND HEIGHTEN THE EXTENT AND INTENSITY OF THE SNOW BANDING.
MOISTURE AVAILABILITY WILL GENERALLY NOT BE A PROBLEM WITH VERY HIGH
PW (OVER 200 PERCENT OF NORMAL) AND A STRONG MOISTURE TRANSPORT FROM
THE GULF... ALTHOUGH THE INCOMING DRY SLOT ON THE SE SIDE OF THE LOW
WILL BE WORTH MONITORING AND MAY LIMIT WINTRY TOTALS IN THE
SOUTHEAST CWA (SEE BELOW). HOW FAST THE COLD AIR ARRIVES ESPECIALLY
ALOFT REMAINS A CONCERN... ALTHOUGH THE MODELS INITIALIZED WELL AND
ARE IN VERY GOOD AGREEMENT... BOOSTING CONFIDENCE IN THEIR TIMING OF
THE ANTICIPATED THERMAL CHANGES.
THE HEAVIEST SNOW BANDING IS LIKELY TO OCCUR OVER THE WRN AND NRN
PIEDMONT... FROM HIGH ROCK AND BADIN LAKES... ACROSS THE I-40 AND
HIGHWAY 64 CORRIDORS BETWEEN (AND INCLUDING) THE TRIAD AND THE
TRIANGLE... UP TO KERR LAKE AND LAKE GASTON... VERY ROUGHLY
FOLLOWING THE I-85 CORRIDOR TO THE NW... ALIGNED WITH THE AREA OF
STRONGEST DEFORMATION ALOFT. KEY TIMING STILL LOOKS TO BE FROM 23Z
UNTIL AROUND 07Z WITH A QUICK EXIT SOON THEREAFTER. SREF
PROBABILITIES HAVE BEEN VERY CONSISTENT IN SHOWING A 70+ PERCENT
CHANCE OF SNOWFALL RATES OVER ONE INCH PER HOUR ACROSS MUCH OF THE
PIEDMONT AND FAR NRN COASTAL PLAIN FROM MID EVENING UNTIL THE EARLY
OVERNIGHT HOURS. WITH THESE RATES AND THE TIMING OF A FEW HOURS OF
HEAVY BANDED SNOW (STARTING AS A RAIN/SNOW MIX)... STORM TOTAL
ACCUMULATIONS OF 2-4 INCHES IN THIS AREA WITH ISOLATED 5 INCH TOTALS
LOOK QUITE REASONABLE. BORDERING THE WARNING AREA... STILL EXPECT AN
INCH OR SO OF ACCUMULATION MAINLY ON GRASSY AREAS... WITH A LITTLE
SLUSH ON ROADS POSSIBLE.
SOUTH AND EAST OF HERE... INCLUDING FAYETTEVILLE AND CLINTON... A
QUICK BURST OF MAINLY SNOW IS POSSIBLE WITH STRONG DYNAMIC COOLING
THROUGH THE COLUMN AS THE LOW ALOFT PASSES BY... BUT THE WINDOW OF
OPPORTUNITY WILL BE VERY SHORT AS AMOUNTS/DURATION WILL BE GREATLY
LIMITED BY THE MID-UPPER LEVEL DRY SLOT ARRIVAL WITH NOTABLE DRYING
ABOVE THE -5C LEVEL... SUPPRESSING CRYSTAL GROWTH ALOFT... PLUS
BOUNDARY LAYER TEMPS SHOULD HOLD ABOVE FREEZING FOR MUCH OF THIS
EVENT... NOT DROPPING TO NEAR FREEZING UNTIL PRECIP IS NEARLY GONE.
EXPECT LIGHT ACCUMULATIONS OF A DUSTING CONFINED TO GRASSY AREAS.
A SIDE NOTE: MID LEVEL LAPSE RATE PROGS ARE QUITE INTERESTING...
INCLUDING THE 12 KM NAM WHICH INDICATES 850-500 MB VALUES OF 5.5-6.0
C/KM TRAVERSING THE CWA... JUST WNW OF THE 850 MB LOW TRACK...
PRIMARILY BETWEEN 03Z AND 06Z. AND RECENT RAP RUNS TAKE THE 700-400
MB LAPSE RATES (WHICH CAPTURES THE MIXED PHASE REGION ALOFT) UP TO
7.0 C/KM OVER THE NW PIEDMONT TOWARD MIDNIGHT. CONSIDERING THIS
POSSIBILITY FOR UPRIGHT INSTABILITY COMBINED WITH VIGOROUS DYNAMIC
LIFT... A FEW LIGHTNING STRIKES WITHIN SNOW BANDS ARE CERTAINLY
POSSIBLE... ALTHOUGH LIKELY TOO ISOLATED TO INCLUDE IN THE FORECAST
AT THIS TIME.
STRENGTHENING WINDS WILL BE AN ISSUE AS WELL WITH THE TIGHTENING
MSLP GRADIENT AS THE LOW APPROACHES. WE ARE ALREADY SEEING FREQUENT
GUSTS TO 25-40 KTS (ALTHOUGH SOME OF THIS MAY BE AUGMENTED BY A
POSSIBLE GRAVITY WAVE). EXPECT A PERIOD OF SUSTAINED WINDS OF 15-25
MPH WITH SPORADIC GUSTS TO AROUND 30 MPH FROM LATE AFTERNOON UNTIL
AROUND 1-2 AM.
TEMPS SHOULD STEADILY DROP THROUGH THE REST OF THE AFTERNOON AND
NIGHT. -GIH
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 245 AM THURSDAY...
QUITE WEATHER IS EXPECTED TO FINALLY RETURN BY FRIDAY... WITH
SUBSIDENCE AND DRYING IN THE WAKE OF THE THE QUICK MOVING STRONG
S/W... WHICH WILL LIFT OFF TO THE NORTHEAST OF THE AREA ON FRIDAY.
THIS WILL YIELD SUNNY SKIES FOR CENTRAL NC. HOWEVER... AFTERNOON LOW
LEVEL THICKNESS VALUES ARE EXPECTED TO STRUGGLE TO REACH 1300
METERS. THIS COUPLED WITH POSSIBLY SOME SNOW ON THE GROUND ACROSS
PORTIONS OF THE AREA WILL KEEP HIGH TEMPERATURES CHILLY. WILL GO
HIGH TEMPS RANGING FROM THE LOW 40S ACROSS THE NORTH TO UPPER 40S
ACROSS THE SOUTH.
SURFACE HIGH PRESSURE WILL SETTLE OVER THE AREA FOR FRIDAY NIGHT...
BEFORE SHIFTING OFFSHORE ON SATURDAY... WHILE MID/UPPER LEVEL FLOW
GENERALLY REMAINS WESTERLY. THIS WILL CONTINUE TO YIELD SUNNY/CLEAR
SKIES ACROSS THE AREA... WITH A COLD SATURDAY MORNING GIVEN THE
CLEAR SKIES AND CALM TO LIGHT AND VARIABLE WINDS. THUS... WILL GO
WITH LOWS IN THE LOW TO MID 20S FOR SATURDAY MORNING. HIGHS SATURDAY
SHOULD BE WARMER THAN FRIDAY... AS A SOUTHERLY RETURN FLOW DEVELOPS
AND AFTERNOON LOW LEVEL THICKNESS VALUES REBOUND INTO THE 1320S.
HOWEVER... STILL THINK WE WILL SEE HIGH TEMPS ONLY REBOUND TO NEAR
NORMAL OR SLIGHTLY BELOW NORMAL... GENERALLY IN THE UPPER 40S TO
LOWER 50S... AS THE MIXED LAYER WILL BE QUITE SHALLOW. TEMPS SUNDAY
MORNING WILL FOLLOW THE SAME TREND (WARMER THAN THE PREVIOUS
MORNING)... WITH LOWS EXPECTED TO GENERALLY RANGE FROM 30-35 DEGREES.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 3 AM THURSDAY...
MID/UPPER FLOW IS EXPECTED TO BECOME MORE AMPLIFIED WITH A DEEP
TROUGH DEVELOPING ACROSS THE EASTERN U.S.... ALLOWING MUCH COLDER
AIR TO SURGE INTO THE AREA EARLY NEXT WEEK. A COUPLE OF DRY COLD
FRONT ARE EXPECTED TO MOVE THROUGH THE AREA DURING THIS TIMEFRAME...
ONE LATE SUNDAY INTO SUNDAY AND ANOTHER POSSIBLE DRY COLD FRONT ON
WEDNESDAY. SUNDAY LOOKS TO BE THE WARMEST DAY OF THE MEDIUM RANGE
RANGE... AHEAD OF A STRONG COLD FRONT WHICH SHOULD BRING SOME OF THE
COLD AIR YET OF THE WINTER SEASON. THUS... EXPECT HIGHS SUNDAY WILL
RANGE FROM AROUND 50 NW TO NEAR 60 SOUTH/SOUTHEAST (A BIT OF TRICKY
TEMP FORECAST THOUGH GIVEN ABOUT 6 TO 9 HOURS DIFFERENCE BETWEEN THE
GFS AND ECWMF). HIGHS AND LOW TEMPS FOR THE REMAINDER OF THE PERIOD
ARE EXPECTED TO BE BELOW NORMAL... WITH LOW TEMPS GENERALLY IN THE
20S... WITH POSSIBLY EVEN SOME TEENS BY TUESDAY MORNING IN THE COLD
OUTLYING AREAS. HIGH TEMPS ARE GENERALLY EXPECTED TO BE IN THE
40S... WITH MAYBE A FEW LOCATIONS ACROSS THE NORTH ON TUESDAY
STRUGGLING TO REACH 40 DEGREES.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 1250 PM THURSDAY...
24 HOUR TAF PERIOD:
LIGHT TO MODERATE RAIN WILL CONTINUE OVER THE WRN HALF OF THE AREA
AND SLOWLY MOVE EAST THIS EVENING AS THE SURFACE LOW TRACKS NE INTO
CENTRAL NC. HIGH CONFIDENCE THAT IFR AND LIFR AVIATION CONDITIONS
WILL CONTINUE THROUGH APPROX 12Z FRIDAY. RAIN WILL CHANGE TO SNOW
FROM WEST TO EAST...WITH SOME UNCERTAINTY ON THE EXACT TIMING OF THE
CHANGE OVER. FOR NOW HAVE SNOW STARTING AROUND 23Z AT KINT AND KGSO
TO 02-04Z AT KRDU AND KRWI...WITH THE CHANCE FOR A BRIEF PERIOD OF
SNOW AT KFAY AROUND 05Z FRIDAY. SNOW AND FOG WILL KEEP LIFR
CONDITIONS IN PLACE THROUGH 05Z-06Z. RESIDUAL LOW LEVEL MOISTURE MAY
KEEP VISBYS LOW EVEN AFTER THE SNOW ENDS. AVIATION CONDITIONS SHOULD
IMPROVE TO VFR AROUND SUNRISE. NNE WINDS AROUND 10-20 KTS THIS
EVENING WILL SHIFT TO THE NW AS THE FRONT MOVES THROUGH CENTRAL NC
OVERNIGHT.
LOOKING AHEAD:
VFR CONDITIONS EXPECTED FRIDAY NIGHT THROUGH TUESDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 4 AM EST FRIDAY
FOR NC028-042-043-077-078-083-084.
WINTER STORM WARNING FROM 6 PM THIS EVENING TO 4 AM EST FRIDAY FOR
NCZ007>011-021>027-038>041-073>076.
&&
$$
SYNOPSIS...HARTFIELD/KC
NEAR TERM...HARTFIELD
SHORT TERM...BSD
LONG TERM...BSD
AVIATION...WSS
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
959 AM CST THU JAN 17 2013
.DISCUSSION...
THE MAIN CHALLENGE TODAY WILL BE TEMPS. SFC HIGH PRESSURE WILL
BUILD INTO THE REGION...AND TEMPS WON/T WARM TOO MUCH FROM CURRENT
READINGS. WILL TAKE A LOOK AT CURRENT TEMPS...BUT NOT EXPECTING
TOO MANY CHANGES FROM CURRENT FORECAST THIS MORNING.
&&
.AVIATION...
MIXED VFR AND MVFR CLOUD DECKS AROUND THIS MORNING WITH SOME
POTENTIAL FOR CLEARING INTO NE ND/NW MN THRU THIS AFTN. WINDS
WILL BE PRETTY LIGHT TODAY...GENERALLY 10 KTS OR LESS...BUT MAY BE
MORE VARIABLE IN DIRECTION DUE TO RATHER WEAK SFC FEATURES. WINDS
WILL TURN SOUTHERLY TONIGHT AND INCREASE TO THE 10 TO 20 KT RANGE
IN THE RRV AND ERN ND. CLOUDS WILL SPREAD OVER THE REGION AGAIN
WITH LIGHT SNOW MOVING INTO DVL-GFK BY 06Z AND THEN SPREADING
EAST. SOME MVFR CIGS AND VSBYS PSBL WITH THIS SYSTEM.
&&
.PREV DISCUSSION... /ISSUED 615 AM CST THU JAN 17 2013/
UPDATE...
FLURRIES PERSISTING LONGER THAN THOUGHT PER RADAR AND OBS. ONCE
AGAIN RAP MODEL DOING WELL AND HAS THE FLURRIES EXITING THE
SOUTHEAST FCST AREA 16-17Z. WILL MENTION FLURRIES IN MUCH OF
NW/WCNTRL MN INTO FAR SE ND UNTIL THEN AS WAVE MOVES THROUGH.
NOTING A PERIOD OF 20 TO 30 KT WIND GUST SPREADING THRU DVL BASIN
WITH CLEARING PROGRESSING SOUTHEAST QUICKLY.
PREV DISCUSSION... /ISSUED 344 AM CST THU JAN 17 2013/
SHORT TERM...
WATER VAPOR SHOWS THE RIGHT FRONT OF A 300 MB 150KT JET OVER NE
ND/NW MN THIS MORNING. A COUPLE OF WEAK 500 MB SHORT WAVES ON THE
SOUTH EDGE OF JET MAX FROM SRN SASK INTO CNTRL-SE ND. ONCE WEAK
SYSTEM MOVING THRU ERN ND ATTM INTO WCNTRL MN PRODUCING SOME
FLURRIES. MAIN RESULT OF JET MAX IS TO PRODUCE AN EXPANSIVE CLOUD
SHIELD WHICH HAS MOVED OVER ALL OF THE FCST AREA OVERNIGHT CAUSING
RISING TEMPS IN NW MN WHICH DID DROP INTO THE MID TEENS BELOW
EARLY THIS EVE. AS A RESULT OF WARMING TEMPS AND LIGHT WINDS HAVE
CANCELLED WIND CHILL ADV.
SHORT TERM MODELS SUCH AS THE RAP INSIST SOME CLEARING WILL MOVE
INTO FAR NE ND AND NW MN LATER THIS MORNING AND AFTN AND SOME
CLEARING IS NOTED IN PATCHY FASHION MOVING INTO SW MANITOBA ATTM
FROM CNTRL SASK. THUS SOME SUN PSBL LATER TODAY.
TEMPS A REAL CONCERN THRU THE PD. SFC MAP SHOWS A WK LOW NR DVL
MOVING SOUTHEAST ALONG A THERMAL BOUNDARY FROM SE SASK INTO SE
ND...NR AN ESTEVAN TO MINOT TO JAMESTOWN TO ABERDEEN LINE. TEMPS
INTO THE TEENS IN THE FAR WRN FCST AREA ATTM AND EXPECT AS WINDS
TURN A BIT MORE NORTH AFTER SUNRISE TEMPS TO FALL A BIT. REST OF
THE FCST AREA TO REMAIN CHILLY WITH HIGHS TODAY IN THE SINGLE
DIGITS...WITH TEMPS STRUGGLING TO REACH ZERO IN FAR NORTHEAST FCST
AREA WHERE COLDEST AIRMASS RESIDES.
TONIGHT WILL SEE NEXT SHORT WAVE WHICH WILL MOVE INTO CNTRL
ALBERTA MOVE SOUTHEAST. THIS SYSTEM WILL BE MORE PRESENT AT THE
925-850 MB LEVEL WHERE LOWER LEVEL WARM ADVECTION ZONE WILL
STRENGTHEN TONIGHT FROM WRN MANITOBA INTO ERN ND/NW MN. THUS DO
LOOK FOR A BAND OF WARM ADV SNOW TO EXPAND SOUTHEAST INTO DVL
BASIN BEFORE 06Z AND THEN SPREAD EAST OVERNIGHT...WITH WARM ADV
MAXIMIZING IN NW MN LATE TONIGHT WHERE 1-2 INCHES OF SNOW MAY FALL
UP IN THE ROSEAU-WARROAD-BAUDETTE AREAS. STRONG WARMING AT THE SFC
TO AS WINDS TURN SOUTHERLY AND INCREASE TO 10 TO 20 KTS. AS WHAT
OCCURRED A FEW DAYS AGO EXPECT RISING TEMPS OVER ERN ND TONIGHT
REACHING THE 20S. AIRMASS TO REMAIN RATHER MILD INTO FRIDAY AS
WELL SOUTH OF A STRONGER SHORT WAVE AND SFC LOW WHICH WILL MOVE
FROM NORTHERN ALBERTA SOUTHEAST TOWARD LAKE OF THE WOODS REGION
SATURDAY. SOME LIGHT SNOW WITH THIS SYSTEM AS WELL...BUT MOSTLY
OVER FAR NW MN INTO ONTARIO. TEMPS FRIDAY SOUTH OF THE LOW WILL
RISE INTO THE LOW-MID 30S AS 925 MB TEMPS RISE TO ABOVE ZERO IN
AREAS FROM DVL TO FARGO TO FERGUS FALLS SOUTHWARD.
SATURDAY PROMISES TO BE AN INTERESTING DAY AS SFC LOW MOVES FROM
LAKE OF THE WOODS REGION SOUTHEAST AND IN ITS WAKE WILL BE STRONG
COLD ADVECTION WITH 925 MB TEMPS DROPPING SOME 20 DEGREES DURING
THE DAY SATURDAY WITH 25 TO 30 KT SFC WINDS FROM THE NORTH. HOURLY
TEMPS A REAL HEADACHE AS COULD WELL BE IN THE 20S TO START IN SE
ND/WCNTRL MN...BUT ALL AREAS WILL SEE FALLING TEMPS INTO THE
SINGLE DIGITS ABOVE AND BELOW ZERO IN THE AFTN WITH WIND CHILLS IN
THE TEENS AND 20S BELOW.
HIGH PRESSURE WILL MOVE IN SAT NIGHT WITH LIGHTER WINDS AND MAYBE
A PERIOD OF RATHER CLEAR SKY ESP IN THE EVENING. THIS SHOULD ALLOW
FOR WIDESPREAD TEENS BLO ZERO...BUT CLOUDS IN ADVANCE OF THE NEXT
SYSTEM DUE TO ARRIVE SUNDAY WILL LIKELY PREVENT ANY HUGE TEMP
DROP.
LONG TERM (SUNDAY-WEDNESDAY)...
THE 00Z GFS/ECMWF/GEM ARE ALL IN GOOD AGREEMENT THROUGH MUCH OF THE
PERIOD WITH THE OVERALL SYNOPTIC PATTERN EVOLUTION. STRONGLY
MERIDIONAL NORTHWESTERLY FLOW ALOFT IN RESPONSE TO HIGH AMPLITUDE
RIDGING ACROSS WESTERN NORTH AMERICA WILL DRIVE ARCTIC AIR SOUTH ACROSS
THE NORTHERN PLAINS. BOTH THE GFS/ECMWF SHOW 925 MB TEMPS FALLING
INTO THE -25C TO -30C RANGE BY 12Z MONDAY...BEFORE SLOW MODIFICATION
OF THE AIR MASS TAKES PLACE BY THE END OF THE PERIOD AS THE UPPER
AIR PATTERN BEGINS TO DE-AMPLIFY AND THICKNESSES RISE. HIGH TEMPS
WILL GENERALLY BE BELOW ZERO IN MOST AREAS SUNDAY AND
MONDAY...RECOVERING INTO THE SINGLE DIGITS AND TEENS BY WEDNESDAY.
LOW TEMPS LIKELY WILL DEPEND ON CLOUDS AND SFC HIGH POSITION TO SOME
DEGREE...BUT TEMPS DOWN TO NEAR OR BELOW -20F EXPECTED IN MANY AREAS
ON SUNDAY NIGHT AND AGAIN IN SOME AREAS ON MONDAY NIGHT.
AS HAS BEEN THE CASE RECENTLY WITHIN THE NORTHWEST FLOW ALOFT...WEAK
EMBEDDED WAVES MAY BRING PERIODIC CHANCES FOR LIGHT SNOW AND
FLURRIES...BUT THE TIMING AND LOCATION OF THESE SYSTEMS IS UNCERTAIN
AT THIS RANGE. MAINTAINED LOW POPS FOR SUNDAY WITH ONE SYSTEM
DROPPING OUT OF CANADA. SOME INDICATION OF ANOTHER WEAK SYSTEM FOR
MONDAY NIGHT OR TUESDAY...BUT WILL STICK WITH DRY FORECAST FOR NOW
DUE TO LOW CONFIDENCE. OTHERWISE...A SERIES OF ARCTIC HIGHS DROPPING
SOUTH WILL RESULT IN FAIRLY TRANQUIL WEATHER FOR MUCH OF THE PERIOD.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
DK
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
615 AM CST THU JAN 17 2013
.UPDATE...
FLURRIES PERSISTING LONGER THAN THOUGHT PER RADAR AND OBS. ONCE
AGAIN RAP MODEL DOING WELL AND HAS THE FLURRIES EXITING THE
SOUTHEAST FCST AREA 16-17Z. WILL MENTION FLURRIES IN MUCH OF
NW/WCNTRL MN INTO FAR SE ND UNTIL THEN AS WAVE MOVES THROUGH.
NOTING A PERIOD OF 20 TO 30 KT WIND GUST SPREADING THRU DVL BASIN
WITH CLEARING PROGRESSING SOUTHEAST QUICKLY.
&&
.PREV DISCUSSION... /ISSUED 344 AM CST THU JAN 17 2013/
SHORT TERM...
WATER VAPOR SHOWS THE RIGHT FRONT OF A 300 MB 150KT JET OVER NE
ND/NW MN THIS MORNING. A COUPLE OF WEAK 500 MB SHORT WAVES ON THE
SOUTH EDGE OF JET MAX FROM SRN SASK INTO CNTRL-SE ND. ONCE WEAK
SYSTEM MOVING THRU ERN ND ATTM INTO WCNTRL MN PRODUCING SOME
FLURRIES. MAIN RESULT OF JET MAX IS TO PRODUCE AN EXPANSIVE CLOUD
SHIELD WHICH HAS MOVED OVER ALL OF THE FCST AREA OVERNIGHT CAUSING
RISING TEMPS IN NW MN WHICH DID DROP INTO THE MID TEENS BELOW
EARLY THIS EVE. AS A RESULT OF WARMING TEMPS AND LIGHT WINDS HAVE
CANCELLED WIND CHILL ADV.
SHORT TERM MODELS SUCH AS THE RAP INSIST SOME CLEARING WILL MOVE
INTO FAR NE ND AND NW MN LATER THIS MORNING AND AFTN AND SOME
CLEARING IS NOTED IN PATCHY FASION MOVING INTO SW MANITOBA ATTM
FROM CNTRL SASK. THUS SOME SUN PSBL LATER TODAY.
TEMPS A REAL CONCERN THRU THE PD. SFC MAP SHOWS A WK LOW NR DVL
MOVING SOUTHEAST ALONG A THERMAL BOUNDARY FROM SE SASK INTO SE
ND...NR AN ESTEVAN TO MINOT TO JAMESTOWN TO ABERDEEN LINE. TEMPS
INTO THE TEENS IN THE FAR WRN FCST AREA ATTM AND EXPECT AS WINDS
TURN A BIT MORE NORTH AFTER SUNRISE TEMPS TO FALL A BIT. REST OF
THE FCST AREA TO REMAIN CHILLY WITH HIGHS TODAY IN THE SINGLE
DIGITS...WITH TEMPS STRUGGLING TO REACH ZERO IN FAR NORTHEAST FCST
AREA WHERE COLDEST AIRMASS RESIDES.
TONIGHT WILL SEE NEXT SHORT WAVE WHICH WILL MOVE INTO CNTRL
ALBERTA MOVE SOUTHEAST. THIS SYSTEM WILL BE MORE PRESENT AT THE
925-850 MB LEVEL WHERE LOWER LEVEL WARM ADVECTION ZONE WILL
STRENGTHEN TONIGHT FROM WRN MANITOBA INTO ERN ND/NW MN. THUS DO
LOOK FOR A BAND OF WARM ADV SNOW TO EXPAND SOUTHEAST INTO DVL
BASIN BEFORE 06Z AND THEN SPREAD EAST OVERNIGHT...WITH WARM ADV
MAXIMIZING IN NW MN LATE TONIGHT WHERE 1-2 INCHES OF SNOW MAY FALL
UP IN THE ROSEAU-WARROAD-BAUDETTE AREAS. STRONG WARMING AT THE SFC
TO AS WINDS TURN SOUTHERLY AND INCREASE TO 10 TO 20 KTS. AS WHAT
OCCURRED A FEW DAYS AGO EXPECT RISING TEMPS OVER ERN ND TONIGHT
REACHING THE 20S. AIRMASS TO REMAIN RATHER MILD INTO FRIDAY AS
WELL SOUTH OF A STRONGER SHORT WAVE AND SFC LOW WHICH WILL MOVE
FROM NORTHERN ALBERTA SOUTHEAST TOWARD LAKE OF THE WOODS REGION
SATURDAY. SOME LIGHT SNOW WITH THIS SYSTEM AS WELL...BUT MOSTLY
OVER FAR NW MN INTO ONTARIO. TEMPS FRIDAY SOUTH OF THE LOW WILL
RISE INTO THE LOW-MID 30S AS 925 MB TEMPS RISE TO ABOVE ZERO IN
AREAS FROM DVL TO FARGO TO FERGUS FALLS SOUTHWARD.
SATURDAY PROMISES TO BE AN INTERESTING DAY AS SFC LOW MOVES FROM
LAKE OF THE WOODS REGION SOUTHEAST AND IN ITS WAKE WILL BE STRONG
COLD ADVECTION WITH 925 MB TEMPS DROPPING SOME 20 DEGREES DURING
THE DAY SATURDAY WITH 25 TO 30 KT SFC WINDS FROM THE NORTH. HOURLY
TEMPS A REAL HEADACHE AS COULD WELL BE IN THE 20S TO START IN SE
ND/WCNTRL MN...BUT ALL AREAS WILL SEE FALLING TEMPS INTO THE
SINGLE DIGITS ABOVE AND BELOW ZERO IN THE AFTN WITH WIND CHILLS IN
THE TEENS AND 20S BELOW.
HIGH PRESSURE WILL MOVE IN SAT NIGHT WITH LIGHTER WINDS AND MAYBE
A PERIOD OF RATHER CLEAR SKY ESP IN THE EVENING. THIS SHOULD ALLOW
FOR WIDESPREAD TEENS BLO ZERO...BUT CLOUDS IN ADVANCE OF THE NEXT
SYSTEM DUE TO ARRIVE SUNDAY WILL LIKELY PREVENT ANY HUGE TEMP
DROP.
LONG TERM (SUNDAY-WEDNESDAY)...
THE 00Z GFS/ECMWF/GEM ARE ALL IN GOOD AGREEMENT THROUGH MUCH OF THE
PERIOD WITH THE OVERALL SYNOPTIC PATTERN EVOLUTION. STRONGLY
MERIDIONAL NORTHWESTERLY FLOW ALOFT IN RESPONSE TO HIGH AMPLITUDE
RIDGING ACROSS WESTERN NORTH AMERICA WILL DRIVE ARCTIC AIR SOUTH ACROSS
THE NORTHERN PLAINS. BOTH THE GFS/ECMWF SHOW 925 MB TEMPS FALLING
INTO THE -25C TO -30C RANGE BY 12Z MONDAY...BEFORE SLOW MODIFICATION
OF THE AIR MASS TAKES PLACE BY THE END OF THE PERIOD AS THE UPPER
AIR PATTERN BEGINS TO DE-AMPLIFY AND THICKNESSES RISE. HIGH TEMPS
WILL GENERALLY BE BELOW ZERO IN MOST AREAS SUNDAY AND
MONDAY...RECOVERING INTO THE SINGLE DIGITS AND TEENS BY WEDNESDAY.
LOW TEMPS LIKELY WILL DEPEND ON CLOUDS AND SFC HIGH POSITION TO SOME
DEGREE...BUT TEMPS DOWN TO NEAR OR BELOW -20F EXPECTED IN MANY AREAS
ON SUNDAY NIGHT AND AGAIN IN SOME AREAS ON MONDAY NIGHT.
AS HAS BEEN THE CASE RECENTLY WITHIN THE NORTHWEST FLOW ALOFT...WEAK
EMBEDDED WAVES MAY BRING PERIODIC CHANCES FOR LIGHT SNOW AND
FLURRIES...BUT THE TIMING AND LOCATION OF THESE SYSTEMS IS UNCERTAIN
AT THIS RANGE. MAINTAINED LOW POPS FOR SUNDAY WITH ONE SYSTEM
DROPPING OUT OF CANADA. SOME INDICATION OF ANOTHER WEAK SYSTEM FOR
MONDAY NIGHT OR TUESDAY...BUT WILL STICK WITH DRY FORECAST FOR NOW
DUE TO LOW CONFIDENCE. OTHERWISE...A SERIES OF ARCTIC HIGHS DROPPING
SOUTH WILL RESULT IN FAIRLY TRANQUIL WEATHER FOR MUCH OF THE PERIOD.
AVIATION...
MIXED VFR AND MVFR CLOUD DECKS AROUND THIS MORNING WITH SOME
POTENTIAL FOR CLEARING INTO NE ND/NW MN LATER THIS MORNING THRU
THIS AFTN. WINDS WILL BE PRETTY LIGHT TODAY...GENERALLY 10 KTS OR
LESS...BUT MAY BE MORE VARIABLE IN DIRECTION DUE TO RATHER WEAK
SFC FEATURES. WINDS WILL TURN SOUTHERY TONIGHT AND INCREASE TO THE
10 TO 20 KT RANGE IN THE RRV AND ERN ND. CLOUDS WILL SPREAD OVER
THE REGION AGAIN WITH LIGHT SNOW MOVING INTO DVL-GFK BY 06Z AND
THEN SPREADING EAST. SOME MVFR CIGS AND VSBYS PSBL WITH THIS
SYSTEM.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
RIDDLE/MAKOWSKI
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
344 AM CST THU JAN 17 2013
.SHORT TERM...
WATER VAPOR SHOWS THE RIGHT FRONT OF A 300 MB 150KT JET OVER NE
ND/NW MN THIS MORNING. A COUPLE OF WEAK 500 MB SHORT WAVES ON THE
SOUTH EDGE OF JET MAX FROM SRN SASK INTO CNTRL-SE ND. ONCE WEAK
SYSTEM MOVING THRU ERN ND ATTM INTO WCNTRL MN PRODUCING SOME
FLURRIES. MAIN RESULT OF JET MAX IS TO PRODUCE AN EXPANSIVE CLOUD
SHIELD WHICH HAS MOVED OVER ALL OF THE FCST AREA OVERNIGHT CAUSING
RISING TEMPS IN NW MN WHICH DID DROP INTO THE MID TEENS BELOW
EARLY THIS EVE. AS A RESULT OF WARMING TEMPS AND LIGHT WINDS HAVE
CANCELLED WIND CHILL ADV.
SHORT TERM MODELS SUCH AS THE RAP INSIST SOME CLEARING WILL MOVE
INTO FAR NE ND AND NW MN LATER THIS MORNING AND AFTN AND SOME
CLEARING IS NOTED IN PATCHY FASION MOVING INTO SW MANITOBA ATTM
FROM CNTRL SASK. THUS SOME SUN PSBL LATER TODAY.
TEMPS A REAL CONCERN THRU THE PD. SFC MAP SHOWS A WK LOW NR DVL
MOVING SOUTHEAST ALONG A THERMAL BOUNDARY FROM SE SASK INTO SE
ND...NR AN ESTEVAN TO MINOT TO JAMESTOWN TO ABERDEEN LINE. TEMPS
INTO THE TEENS IN THE FAR WRN FCST AREA ATTM AND EXPECT AS WINDS
TURN A BIT MORE NORTH AFTER SUNRISE TEMPS TO FALL A BIT. REST OF
THE FCST AREA TO REMAIN CHILLY WITH HIGHS TODAY IN THE SINGLE
DIGITS...WITH TEMPS STRUGGLING TO REACH ZERO IN FAR NORTHEAST FCST
AREA WHERE COLDEST AIRMASS RESIDES.
TONIGHT WILL SEE NEXT SHORT WAVE WHICH WILL MOVE INTO CNTRL
ALBERTA MOVE SOUTHEAST. THIS SYSTEM WILL BE MORE PRESENT AT THE
925-850 MB LEVEL WHERE LOWER LEVEL WARM ADVECTION ZONE WILL
STRENGTHEN TONIGHT FROM WRN MANITOBA INTO ERN ND/NW MN. THUS DO
LOOK FOR A BAND OF WARM ADV SNOW TO EXPAND SOUTHEAST INTO DVL
BASIN BEFORE 06Z AND THEN SPREAD EAST OVERNIGHT...WITH WARM ADV
MAXIMIZING IN NW MN LATE TONIGHT WHERE 1-2 INCHES OF SNOW MAY FALL
UP IN THE ROSEAU-WARROAD-BAUDETTE AREAS. STRONG WARMING AT THE SFC
TO AS WINDS TURN SOUTHERLY AND INCREASE TO 10 TO 20 KTS. AS WHAT
OCCURRED A FEW DAYS AGO EXPECT RISING TEMPS OVER ERN ND TONIGHT
REACHING THE 20S. AIRMASS TO REMAIN RATHER MILD INTO FRIDAY AS
WELL SOUTH OF A STRONGER SHORT WAVE AND SFC LOW WHICH WILL MOVE
FROM NORTHERN ALBERTA SOUTHEAST TOWARD LAKE OF THE WOODS REGION
SATURDAY. SOME LIGHT SNOW WITH THIS SYSTEM AS WELL...BUT MOSTLY
OVER FAR NW MN INTO ONTARIO. TEMPS FRIDAY SOUTH OF THE LOW WILL
RISE INTO THE LOW-MID 30S AS 925 MB TEMPS RISE TO ABOVE ZERO IN
AREAS FROM DVL TO FARGO TO FERGUS FALLS SOUTHWARD.
SATURDAY PROMISES TO BE AN INTERESTING DAY AS SFC LOW MOVES FROM
LAKE OF THE WOODS REGION SOUTHEAST AND IN ITS WAKE WILL BE STRONG
COLD ADVECTION WITH 925 MB TEMPS DROPPING SOME 20 DEGREES DURING
THE DAY SATURDAY WITH 25 TO 30 KT SFC WINDS FROM THE NORTH. HOURLY
TEMPS A REAL HEADACHE AS COULD WELL BE IN THE 20S TO START IN SE
ND/WCNTRL MN...BUT ALL AREAS WILL SEE FALLING TEMPS INTO THE
SINGLE DIGITS ABOVE AND BELOW ZERO IN THE AFTN WITH WIND CHILLS IN
THE TEENS AND 20S BELOW.
HIGH PRESSURE WILL MOVE IN SAT NIGHT WITH LIGHTER WINDS AND MAYBE
A PERIOD OF RATHER CLEAR SKY ESP IN THE EVENING. THIS SHOULD ALLOW
FOR WIDESPREAD TEENS BLO ZERO...BUT CLOUDS IN ADVANCE OF THE NEXT
SYSTEM DUE TO ARRIVE SUNDAY WILL LIKELY PREVENT ANY HUGE TEMP
DROP.
.LONG TERM (SUNDAY-WEDNESDAY)...
THE 00Z GFS/ECMWF/GEM ARE ALL IN GOOD AGREEMENT THROUGH MUCH OF THE
PERIOD WITH THE OVERALL SYNOPTIC PATTERN EVOLUTION. STRONGLY
MERIDIONAL NORTHWESTERLY FLOW ALOFT IN RESPONSE TO HIGH AMPLITUDE
RIDGING ACROSS WESTERN NORTH AMERICA WILL DRIVE ARCTIC AIR SOUTH ACROSS
THE NORTHERN PLAINS. BOTH THE GFS/ECMWF SHOW 925 MB TEMPS FALLING
INTO THE -25C TO -30C RANGE BY 12Z MONDAY...BEFORE SLOW MODIFICATION
OF THE AIR MASS TAKES PLACE BY THE END OF THE PERIOD AS THE UPPER
AIR PATTERN BEGINS TO DE-AMPLIFY AND THICKNESSES RISE. HIGH TEMPS
WILL GENERALLY BE BELOW ZERO IN MOST AREAS SUNDAY AND
MONDAY...RECOVERING INTO THE SINGLE DIGITS AND TEENS BY WEDNESDAY.
LOW TEMPS LIKELY WILL DEPEND ON CLOUDS AND SFC HIGH POSITION TO SOME
DEGREE...BUT TEMPS DOWN TO NEAR OR BELOW -20F EXPECTED IN MANY AREAS
ON SUNDAY NIGHT AND AGAIN IN SOME AREAS ON MONDAY NIGHT.
AS HAS BEEN THE CASE RECENTLY WITHIN THE NORTHWEST FLOW ALOFT...WEAK
EMBEDDED WAVES MAY BRING PERIODIC CHANCES FOR LIGHT SNOW AND
FLURRIES...BUT THE TIMING AND LOCATION OF THESE SYSTEMS IS UNCERTAIN
AT THIS RANGE. MAINTAINED LOW POPS FOR SUNDAY WITH ONE SYSTEM
DROPPING OUT OF CANADA. SOME INDICATION OF ANOTHER WEAK SYSTEM FOR
MONDAY NIGHT OR TUESDAY...BUT WILL STICK WITH DRY FORECAST FOR NOW
DUE TO LOW CONFIDENCE. OTHERWISE...A SERIES OF ARCTIC HIGHS DROPPING
SOUTH WILL RESULT IN FAIRLY TRANQUIL WEATHER FOR MUCH OF THE PERIOD.
&&
.AVIATION...
MIXED VFR AND MVFR CLOUD DECKS AROUND THIS MORNING WITH SOME
POTENTIAL FOR CLEARING INTO NE ND/NW MN LATER THIS MORNING THRU
THIS AFTN. WINDS WILL BE PRETTY LIGHT TODAY...GENERALLY 10 KTS OR
LESS...BUT MAY BE MORE VARIABLE IN DIRECTION DUE TO RATHER WEAK
SFC FEATURES. WINDS WILL TURN SOUTHERY TONIGHT AND INCREASE TO THE
10 TO 20 KT RANGE IN THE RRV AND ERN ND. CLOUDS WILL SPREAD OVER
THE REGION AGAIN WITH LIGHT SNOW MOVING INTO DVL-GFK BY 06Z AND
THEN SPREADING EAST. SOME MVFR CIGS AND VSBYS PSBL WITH THIS
SYSTEM.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
RIDDLE/MAKOWSKI
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1129 PM CST WED JAN 16 2013
.DISCUSSION...LATEST SURFACE MAP SHOWS A STATIONARY FRONT STRETCHING
FROM MOOSE JAW IN CANADA...SOUTHEAST TO WILLISTON...DICKINSON AND
CURVING INTO PIERRE SOUTH DAKOTA. 925MB ISOTHERM STRUCTURE ON THE
NAM AND HOURLY RAP MODEL CLEARLY SHOW THE BAROCLINIC BOUNDARY
DEFINING THIS FRONT. TWO WAVES OF LOW PRESSURE WERE OBSERVED...ONE
NEAR KILLDEER IN DUNN COUNTY...AND THE SECOND FURTHER UPSTREAM
WEST OF CROSBY. MODEL GUIDANCE SUGGESTS RISING TEMPERATURES
OVERNIGHT FOR MANY LOCATIONS ALONG THE FRONT AND AHEAD OF THE
LOWS. THIS WOULD MAINLY AFFECT SOUTH CENTRAL NORTH DAKOTA. AS EACH
WAVE SLIDES ALONG THE BOUNDARY OVERNIGHT INTO THURSDAY
MORNING...THE BOUNDARY IS FORCED TO BULGE NORTHEAST...THUS
ALLOWING A WARM-UP FROM THE SFC-925MB...THEN QUICKLY COOLS DOWN
AGAIN AS THE LOW DEPARTS AND THE BAROCLINIC ZONE IS FORCED TO
RETREAT FURTHER SOUTHWEST. TEMPERATURES WILL BE A CHALLENGE
OVERNIGHT...VERY MUCH DEPENDENT ON THE POSITION OF THE SURFACE
LOWS AT EACH HOUR THROUGH 15Z THURSDAY. THIS TREND IS ALREADY
OCCURRING...AS KBIS HAS WARMED 4 DEGREES IN THE LAST 3HRS. THE
CHALLENGE WILL BE JUST HOW MUCH WARMING WILL OCCUR. THE RAP
SUGGESTS TEMPERATURES RISING TO AROUND 32F BY 12Z AT KBIS. WILL
BLEND THE CURRENT FORECAST WITH THE RAP WHICH WILL SHOW A WARMING
TREND TO AROUND 30 BY MORNING. ONCE THE SURFACE LOW SHIFTS TO THE
SOUTHEAST...TEMPERATURES WILL ACTUALLY FALL DURING THE 12Z TO 18Z
TIME FRAME. WILL ALSO CONTINUE WITH THE MENTION OF FLURRIES
OVERNIGHT WHERE THE BAROCLINIC ZONE AND SURFACE LOWS INTERACT.
CURRENT RADAR RETURNS REMAIN CONSISTENT WITH THIS IDEA.
&&
.AVIATION...A FRONTAL BOUNDARY WILL REMAIN SITUATED NORTHWEST TO
SOUTHEAST ACROSS THE FORECAST AREA TONIGHT. LOW PRESSURE SLIDING
SOUTHEAST ALONG THE BOUNDARY WILL PRODUCE AREAS OF MVFR CLOUDS AND
POSSIBLY A FEW PERIODS OF LIGHT SNOW...MAINLY FROM WILLISTON AND
MINOT SOUTHEAST TO BISMARCK AND JAMESTOWN. THE BOUNDARY WILL DROP
SOUTH ON THURSDAY WITH SURFACE FLOW TURNING MORE NORTHERLY EAST OF
THE BOUNDARY...AND A WESTERLY FLOW WEST OF THE BOUNDARY. THE
BOUNDARY WILL THEN LIFT NORTHEAST LATE THURSDAY AND THURSDAY NIGHT
AS A WARM FRONT. DEPICTING LOW CEILINGS WILL BE TROUBLESOME UNTIL
LATE IN THE FORECAST PERIOD WHEN THE BOUNDARY LIFTS NORTHEAST AND
DRIER AIR WORKS INTO THE AREA BEHIND THE WARM FRONT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
DISCUSSION...KS
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1250 PM EST THU JAN 17 2013
.SYNOPSIS...
CLOUD COVER WILL CONTINUE FOR MUCH OF TODAY AS THE OHIO VALLEY
RESIDES BETWEEN LOW PRESSURE TO THE SOUTH...AND HIGH PRESSURE TO
THE WEST. THE HIGH WILL BUILD EASTWARD TONIGHT...BRINGING THE AREA
A PERIOD OF SEASONABLE TEMPERATURES AND FAIR WEATHER THROUGH
SATURDAY. SOME SNOW SHOWERS WILL BECOME POSSIBLE SATURDAY NIGHT AS
AN ARCTIC AIRMASS BEGINS TO MOVE INTO OUR REGION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AMPLE CLOUD COVER EXTENDS ACROSS THE AREA UNDER A DENSE HIGH
CLOUD CANOPY ASSOCIATED WITH A STRONG UPPER LEVEL JET. PATCHES OF
LOW CLOUDS ARE ALSO OCCURRING UNDER THIS DECK PRIMARILY ASSOCIATED
WITH MOIST LOW LEVEL NORTHERLY FLOW. MODELS ARE IN DISAGREEMENT ON
HOW TO HANDLE THIS LOW LEVEL MOISTURE AS WE GO THROUGH THE DAY.
THE HIGH CLOUDS WILL GRADUALLY SHIFT EAST AS THE JET MAX EXITS OUR
REGION TODAY. THE RAP INDICATES THAT MUCH OF THE LOW CLOUD COVER
WILL CONTINUE THROUGHOUT THE DAY. THE NAM SUGGESTS CLEARING THIS
AFTERNOON. FOLLOWING THE PERSISTENT TREND FOR THE PAST SEVERAL
DAYS...WILL BE PESSIMISTIC ABOUT CLEARING TODAY. THIS WILL RESULT
IN HIGH TEMPERATURES IN THE 30S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
A WEAK COLD FRONT WILL PASS ACROSS THE AREA TONIGHT. THIS FRONT
WILL BE MOISTURE STARVED SO KEPT ANY MENTION OF FLURRIES...THAT
HI RES MODELS ARE SUGGESTING...OUT OF THE FORECAST. HIGH PRESSURE
WILL BEGIN TO BUILD BEHIND THIS WEAK FRONT LATE TONIGHT AND INTO
THE DAY FRIDAY. THIS SHOULD FINALLY PROVIDE FOR SOME CLEARING
SKIES...ESPECIALLY ACROSS THE SOUTH AND CLOSER TO THE RIDGE
CENTER. TEMPERATURES WILL REMAIN GENERALLY SEASONABLE THURSDAY
NIGHT AND FRIDAY.
BY FRIDAY NIGHT SOME RETURN FLOW WILL DEVELOP WITH THE LOW LEVEL
PRESSURE GRADIENT INCREASING AS THE RIDGE SHIFTS ACROSS THE
SOUTHEASTERN CONUS AND LOW PRESSURE BEGINS TO PUSH EASTWARD
ACROSS THE GREAT LAKES. WARMER TEMPERATURES MOVING IN AS WELL AS
WINDS KEEPING UP OVERNIGHT WILL LIKELY KEEP TEMPERATURES IN THE
UPPER 20S FOR THE MOST PART.
SURFACE GRADIENT WILL TIGHTEN FURTHER ON SATURDAY AS THE LOW
PASSES TO OUR NORTH WHICH WILL PROVIDE BREEZY SOUTHWEST WINDS AND
A RATHER MILD DAY. TEMPERATURES WILL LIKELY TOP OUT IN THE MIDDLE
40S ACROSS THE NORTH TO THE LOWER 50S ACROSS THE SOUTH.
A DEEP UPPER TROUGH BEGINS TO DIG SOUTH INTO OUR REGION SATURDAY
NIGHT AS THE SURFACE LOW REACHES THE EASTERN GREAT LAKES. AS THIS
OCCURS...AN ARCTIC COLD FRONT WILL ARRIVE AT OUR DOORSTEP. SOME
LIGHT PRECIPITATION IN THE FORM OF SNOW SHOWERS LOOKS
POSSIBLE BEHIND THIS FRONT...ESPECIALLY ACROSS THE NORTHERN
PORTIONS OF THE FORECAST AREA. BEHIND THIS STRONG COLD
FRONT...BREEZY NORTHWEST WINDS WILL BRING MUCH COLDER AND DRIER
AIR ACROSS THE REGION SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
WEAK SHORT WAVES WILL BRING A SLIGHT CHANCE FOR SNOW SHOWERS ON
MONDAY AND AGAIN ON TUESDAY NIGHT. OTHERWISE...PRECIPITATION IS
NOT EXPECTED IN THE MODIFIED ARCTIC AIRMASS.
ABOVE NORMAL HIGHS ARE EXPECTED FOR SATURDAY IN A BRIEF ROUND OF
WARM ADVECTION AND SOLAR HEATING. IN THE COLDER AIRMASS THAT WILL BE
AROUND FOR THE REST OF THE PERIOD...TEMPERATURES WILL BE WELL BELOW
NORMAL. TUESDAY MAY BE THE COLDEST DAY...WITH HIGHS NOT FORECAST TO
REACH 20 IN MOST LOCATIONS.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
HIGH PRESSURE WILL BUILD INTO THE REGION TONIGHT AND WILL MOVE OFF
TO THE SOUTHEAST ON FRIDAY. A WARM FRONT IS FORECAST TO PIVOT
NORTHEAST ACROSS THE GREAT LAKES ON FRIDAY.
MODELS CONTINUE TO OFFER VARYING SOLUTIONS ON THE AMOUNT OF LOW
LEVEL MOISTURE PRESENT ACROSS THE REGION AHEAD OF A WEAKENING COLD
FRONT. VISIBLE SATELLITE IMAGERY HAS BEEN SHOWING LOW LEVEL
CUMULUS DEVELOPING ACROSS NW OHIO INTO CENTRAL INDIANA.
ATTM...EXPECT A PERIOD OF MVFR CIGS AT KDAY AND HAVE ONLY PLACED
SCATTERED CUMULUS ELSEWHERE. WILL CONTINUE TO MONITOR.
OTHERWISE...AM EXPECTING DIURNAL CUMULUS CLOUDS TO DISSIPATE AFTER
SUNSET.
FOR THE OVERNIGHT PERIOD...MODELS AGAIN KEEP HINTING AT SOME LOW
LEVEL MOISTURE ADVECTING CLOSE TO THE NORTHERN TAF SITES OF KDAY
AND KCMH. I DO NOT HAVE CONFIDENCE ATTM TO PLACE IN THE TAF SO
HAVE LEFT MAINLY CLEAR SKIES FOR NOW.
ON FRIDAY...AVIATORS CAN EXPECTED MID AND HIGH LEVEL CLOUDS TO
ADVECT ACROSS THE REGION AS THEY SPILL INTO THE REGION IN ADVANCE
OF AFOREMENTIONED WARM FRONT. VFR CONDITIONS SHOULD PREVAIL.
OUTLOOK...NO SIGNIFICANT WEATHER IS EXPECTED.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...LATTO
NEAR TERM...HICKMAN/LATTO
SHORT TERM...LATTO
LONG TERM...CONIGLIO
AVIATION...HICKMAN/JGL
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
954 AM EST THU JAN 17 2013
.SYNOPSIS...
CLOUD COVER WILL CONTINUE FOR MUCH OF TODAY AS THE OHIO VALLEY
RESIDES BETWEEN LOW PRESSURE TO THE SOUTH...AND HIGH PRESSURE TO
THE WEST. THE HIGH WILL BUILD EASTWARD TONIGHT...BRINGING THE AREA
A PERIOD OF SEASONABLE TEMPERATURES AND FAIR WEATHER THROUGH
SATURDAY. SOME SNOW SHOWERS WILL BECOME POSSIBLE SATURDAY NIGHT AS
AN ARCTIC AIRMASS BEGINS TO MOVE INTO OUR REGION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AMPLE CLOUD COVER EXTENDS ACROSS THE AREA UNDER A DENSE HIGH
CLOUD CANOPY ASSOCIATED WITH A STRONG UPPER LEVEL JET. PATCHES OF
LOW CLOUDS ARE ALSO OCCURRING UNDER THIS DECK PRIMARILY ASSOCIATED
WITH MOIST LOW LEVEL NORTHERLY FLOW. MODELS ARE IN DISAGREEMENT ON
HOW TO HANDLE THIS LOW LEVEL MOISTURE AS WE GO THROUGH THE DAY.
THE HIGH CLOUDS WILL GRADUALLY SHIFT EAST AS THE JET MAX EXITS OUR
REGION TODAY. THE RAP INDICATES THAT MUCH OF THE LOW CLOUD COVER
WILL CONTINUE THROUGHOUT THE DAY. THE NAM SUGGESTS CLEARING THIS
AFTERNOON. FOLLOWING THE PERSISTENT TREND FOR THE PAST SEVERAL
DAYS...WILL BE PESSIMISTIC ABOUT CLEARING TODAY. THIS WILL RESULT
IN HIGH TEMPERATURES IN THE 30S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
A WEAK COLD FRONT WILL PASS ACROSS THE AREA TONIGHT. THIS FRONT
WILL BE MOISTURE STARVED SO KEPT ANY MENTION OF FLURRIES...THAT
HI RES MODELS ARE SUGGESTING...OUT OF THE FORECAST. HIGH PRESSURE
WILL BEGIN TO BUILD BEHIND THIS WEAK FRONT LATE TONIGHT AND INTO
THE DAY FRIDAY. THIS SHOULD FINALLY PROVIDE FOR SOME CLEARING
SKIES...ESPECIALLY ACROSS THE SOUTH AND CLOSER TO THE RIDGE
CENTER. TEMPERATURES WILL REMAIN GENERALLY SEASONABLE THURSDAY
NIGHT AND FRIDAY.
BY FRIDAY NIGHT SOME RETURN FLOW WILL DEVELOP WITH THE LOW LEVEL
PRESSURE GRADIENT INCREASING AS THE RIDGE SHIFTS ACROSS THE
SOUTHEASTERN CONUS AND LOW PRESSURE BEGINS TO PUSH EASTWARD
ACROSS THE GREAT LAKES. WARMER TEMPERATURES MOVING IN AS WELL AS
WINDS KEEPING UP OVERNIGHT WILL LIKELY KEEP TEMPERATURES IN THE
UPPER 20S FOR THE MOST PART.
SURFACE GRADIENT WILL TIGHTEN FURTHER ON SATURDAY AS THE LOW
PASSES TO OUR NORTH WHICH WILL PROVIDE BREEZY SOUTHWEST WINDS AND
A RATHER MILD DAY. TEMPERATURES WILL LIKELY TOP OUT IN THE MIDDLE
40S ACROSS THE NORTH TO THE LOWER 50S ACROSS THE SOUTH.
A DEEP UPPER TROUGH BEGINS TO DIG SOUTH INTO OUR REGION SATURDAY
NIGHT AS THE SURFACE LOW REACHES THE EASTERN GREAT LAKES. AS THIS
OCCURS...AN ARCTIC COLD FRONT WILL ARRIVE AT OUR DOORSTEP. SOME
LIGHT PRECIPITATION IN THE FORM OF SNOW SHOWERS LOOKS
POSSIBLE BEHIND THIS FRONT...ESPECIALLY ACROSS THE NORTHERN
PORTIONS OF THE FORECAST AREA. BEHIND THIS STRONG COLD
FRONT...BREEZY NORTHWEST WINDS WILL BRING MUCH COLDER AND DRIER
AIR ACROSS THE REGION SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
WEAK SHORT WAVES WILL BRING A SLIGHT CHANCE FOR SNOW SHOWERS ON
MONDAY AND AGAIN ON TUESDAY NIGHT. OTHERWISE...PRECIPITATION IS
NOT EXPECTED IN THE MODIFIED ARCTIC AIRMASS.
ABOVE NORMAL HIGHS ARE EXPECTED FOR SATURDAY IN A BRIEF ROUND OF
WARM ADVECTION AND SOLAR HEATING. IN THE COLDER AIRMASS THAT WILL BE
AROUND FOR THE REST OF THE PERIOD...TEMPERATURES WILL BE WELL BELOW
NORMAL. TUESDAY MAY BE THE COLDEST DAY...WITH HIGHS NOT FORECAST TO
REACH 20 IN MOST LOCATIONS.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
LOW LEVEL CLOUD COVER IS SOMEWHAT TOUGH TO DISCERN THIS MORNING AS
THICK CIRRUS CLOUDS ARE BLOCKING ANY HELP FROM THE IR SATELLITE
IMAGES. BASED ON SURFACE OBS...IT DOES APPEAR THAT THE MVFR SC
DECK IS EXPANDING ACROSS NORTHERN PORTIONS OF OUR FA. THE LATEST
RAP IS INDICATING SOME DECENT 925 MB MOISTURE PUSHING DOWN ACROSS
OUR AREA THROUGH AT LEAST THE REST OF THE MORNING...BUT THE 06Z
NAM IS NOT AS MOIST. GIVEN THAT THE LOW LEVEL CAA WILL CONTINUE
INTO THIS AFTERNOON...WOULD BE INCLINED TO THINK THE MVFR CLOUDS
WOULD STICK AROUND FOR A WHILE. WILL THEREFORE BE A LITTLE SLOWER
TO SCATTER THINGS OUT THIS AFTERNOON BUT DO EXPECT TO EVENTUALLY
SEE AT LEAST SOME PARTIAL CLEARING. LOW LEVEL MOISTURE IS PROGGED
TO INCREASE ACROSS NORTHERN OHIO AGAIN LATER TONIGHT. THIS MAY
ALLOW FOR SOME SC TO SNEAK BACK DOWN TOWARD THE NORTHERN TAFS LATE
IN THE PERIOD.
OUTLOOK...NO SIGNIFICANT WEATHER IS EXPECTED.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...LATTO
NEAR TERM...HICKMAN/LATTO
SHORT TERM...LATTO
LONG TERM...CONIGLIO
AVIATION...JGL
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
637 AM EST THU JAN 17 2013
.SYNOPSIS...
CLOUD COVER WILL CONTINUE FOR MUCH OF TODAY AS THE OHIO VALLEY
RESIDES BETWEEN LOW PRESSURE TO THE SOUTH...AND HIGH PRESSURE TO
THE WEST. THE HIGH WILL BUILD EASTWARD TONIGHT...BRINGING THE AREA
A PERIOD OF SEASONABLE TEMPERATURES AND FAIR WEATHER THROUGH
SATURDAY. SOME SNOW SHOWERS WILL BECOME POSSIBLE SATURDAY NIGHT AS
AN ARCTIC AIRMASS BEGINS TO MOVE INTO OUR REGION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AMPLE CLOUD COVER EXTENDS ACROSS THE AREA UNDER A DENSE HIGH
CLOUD CANOPY ASSOCIATED WITH A STRONG UPPER LEVEL JET. PATCHES OF
LOW CLOUDS ARE ALSO OCCURRING UNDER THIS DECK PRIMARILY ASSOCIATED
WITH MOIST LOW LEVEL NORTHERLY FLOW. MODELS ARE IN DISAGREEMENT ON
HOW TO HANDLE THIS LOW LEVEL MOISTURE AS WE GO THROUGH THE DAY.
THE HIGH CLOUDS WILL GRADUALLY SHIFT EAST AS THE JET MAX EXITS OUR
REGION TODAY. THE RAP INDICATES THAT MUCH OF THE LOW CLOUD COVER
WILL CONTINUE THROUGHOUT THE DAY. THE NAM SUGGESTS CLEARING THIS
AFTERNOON. FOLLOWING THE PERSISTENT TREND FOR THE PAST SEVERAL
DAYS...WILL BE PESSIMISTIC ABOUT CLEARING TODAY. THIS WILL RESULT
IN HIGH TEMPERATURES PEAKING IN THE MIDDLE 30S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
A WEAK COLD FRONT WILL PASS ACROSS THE AREA TONIGHT. THIS FRONT
WILL BE MOISTURE STARVED SO KEPT ANY MENTION OF FLURRIES...THAT
HI RES MODELS ARE SUGGESTING...OUT OF THE FORECAST. HIGH PRESSURE
WILL BEGIN TO BUILD BEHIND THIS WEAK FRONT LATE TONIGHT AND INTO
THE DAY FRIDAY. THIS SHOULD FINALLY PROVIDE FOR SOME CLEARING
SKIES...ESPECIALLY ACROSS THE SOUTH AND CLOSER TO THE RIDGE
CENTER. TEMPERATURES WILL REMAIN GENERALLY SEASONABLE THURSDAY
NIGHT AND FRIDAY.
BY FRIDAY NIGHT SOME RETURN FLOW WILL DEVELOP WITH THE LOW LEVEL
PRESSURE GRADIENT INCREASING AS THE RIDGE SHIFTS ACROSS THE
SOUTHEASTERN CONUS AND LOW PRESSURE BEGINS TO PUSH EASTWARD
ACROSS THE GREAT LAKES. WARMER TEMPERATURES MOVING IN AS WELL AS
WINDS KEEPING UP OVERNIGHT WILL LIKELY KEEP TEMPERATURES IN THE
UPPER 20S FOR THE MOST PART.
SURFACE GRADIENT WILL TIGHTEN FURTHER ON SATURDAY AS THE LOW
PASSES TO OUR NORTH WHICH WILL PROVIDE BREEZY SOUTHWEST WINDS AND
A RATHER MILD DAY. TEMPERATURES WILL LIKELY TOP OUT IN THE MIDDLE
40S ACROSS THE NORTH TO THE LOWER 50S ACROSS THE SOUTH.
A DEEP UPPER TROUGH BEGINS TO DIG SOUTH INTO OUR REGION SATURDAY
NIGHT AS THE SURFACE LOW REACHES THE EASTERN GREAT LAKES. AS THIS
OCCURS...AN ARCTIC COLD FRONT WILL ARRIVE AT OUR DOORSTEP. SOME
LIGHT PRECIPITATION IN THE FORM OF SNOW SHOWERS LOOKS
POSSIBLE BEHIND THIS FRONT...ESPECIALLY ACROSS THE NORTHERN
PORTIONS OF THE FORECAST AREA. BEHIND THIS STRONG COLD
FRONT...BREEZY NORTHWEST WINDS WILL BRING MUCH COLDER AND DRIER
AIR ACROSS THE REGION SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
WEAK SHORT WAVES WILL BRING A SLIGHT CHANCE FOR SNOW SHOWERS ON
MONDAY AND AGAIN ON TUESDAY NIGHT. OTHERWISE...PRECIPITATION IS
NOT EXPECTED IN THE MODIFIED ARCTIC AIRMASS.
ABOVE NORMAL HIGHS ARE EXPECTED FOR SATURDAY IN A BRIEF ROUND OF
WARM ADVECTION AND SOLAR HEATING. IN THE COLDER AIRMASS THAT WILL BE
AROUND FOR THE REST OF THE PERIOD...TEMPERATURES WILL BE WELL BELOW
NORMAL. TUESDAY MAY BE THE COLDEST DAY...WITH HIGHS NOT FORECAST TO
REACH 20 IN MOST LOCATIONS.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
LOW LEVEL CLOUD COVER IS SOMEWHAT TOUGH TO DISCERN THIS MORNING AS
THICK CIRRUS CLOUDS ARE BLOCKING ANY HELP FROM THE IR SATELLITE
IMAGES. BASED ON SURFACE OBS...IT DOES APPEAR THAT THE MVFR SC
DECK IS EXPANDING ACROSS NORTHERN PORTIONS OF OUR FA. THE LATEST
RAP IS INDICATING SOME DECENT 925 MB MOISTURE PUSHING DOWN ACROSS
OUR AREA THROUGH AT LEAST THE REST OF THE MORNING...BUT THE 06Z
NAM IS NOT AS MOIST. GIVEN THAT THE LOW LEVEL CAA WILL CONTINUE
INTO THIS AFTERNOON...WOULD BE INCLINED TO THINK THE MVFR CLOUDS
WOULD STICK AROUND FOR A WHILE. WILL THEREFORE BE A LITTLE SLOWER
TO SCATTER THINGS OUT THIS AFTERNOON BUT DO EXPECT TO EVENTUALLY
SEE AT LEAST SOME PARTIAL CLEARING. LOW LEVEL MOISTURE IS PROGGED
TO INCREASE ACROSS NORTHERN OHIO AGAIN LATER TONIGHT. THIS MAY
ALLOW FOR SOME SC TO SNEAK BACK DOWN TOWARD THE NORTHERN TAFS LATE
IN THE PERIOD.
OUTLOOK...NO SIGNIFICANT WEATHER IS EXPECTED.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...LATTO
NEAR TERM...LATTO
SHORT TERM...LATTO
LONG TERM...CONIGLIO
AVIATION...JGL
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
421 AM EST THU JAN 17 2013
.SYNOPSIS...
CLOUD COVER WILL CONTINUE FOR MUCH OF TODAY AS THE OHIO VALLEY
RESIDES BETWEEN LOW PRESSURE TO THE SOUTH...AND HIGH PRESSURE TO
THE WEST. THE HIGH WILL BUILD EASTWARD TONIGHT...BRINGING THE AREA
A PERIOD OF SEASONABLE TEMPERATURES AND FAIR WEATHER THROUGH
SATURDAY. SOME SNOW SHOWERS WILL BECOME POSSIBLE SATURDAY NIGHT AS
AN ARCTIC AIRMASS BEGINS TO MOVE INTO OUR REGION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A
AMPLE CLOUD COVER EXTENDS ACROSS THE AREA UNDER A DENSE HIGH CLOUD
CANOPY ASSOCIATED WITH A STRONG UPPER LEVEL JET. PATCHES OF LOW
CLOUDS ARE ALSO OCCURRING UNDER THIS DECK PRIMARILY ASSOCIATED WITH
MOIST LOW LEVEL NORTHERLY FLOW. MODELS ARE IN DISAGREEMENT ON HOW
TO HANDLE THIS LOW LEVEL MOISTURE AS WE GO THROUGH THE DAY. THE
HIGH CLOUDS WILL GRADUALLY SHIFT EAST AS THE JET MAX EXITS OUR
REGION TODAY. THE RAP INDICATES THAT MUCH OF THE LOW CLOUD COVER
WILL CONTINUE THROUGHOUT THE DAY. THE NAM SUGGESTS CLEARING THIS
AFTERNOON. FOLLOWING THE PERSISTENT TREND FOR THE PAST SEVERAL
DAYS...WILL BE PESSIMISTIC ABOUT CLEARING TODAY. THIS WILL RESULT
IN HIGH TEMPERATURES PEAKING IN THE MIDDLE 30S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
A WEAK COLD FRONT WILL PASS ACROSS THE AREA TONIGHT. THIS FRONT
WILL BE MOISTURE STARVED SO KEPT ANY MENTION OF FLURRIES...THAT
HI RES MODELS ARE SUGGESTING...OUT OF THE FORECAST. HIGH PRESSURE
WILL BEGIN TO BUILD BEHIND THIS WEAK FRONT LATE TONIGHT AND INTO
THE DAY FRIDAY. THIS SHOULD FINALLY PROVIDE FOR SOME CLEARING
SKIES...ESPECIALLY ACROSS THE SOUTH AND CLOSER TO THE RIDGE
CENTER. TEMPERATURES WILL REMAIN GENERALLY SEASONABLE THURSDAY
NIGHT AND FRIDAY.
BY FRIDAY NIGHT SOME RETURN FLOW WILL DEVELOP WITH THE LOW LEVEL
PRESSURE GRADIENT INCREASING AS THE RIDGE SHIFTS ACROSS THE
SOUTHEASTERN CONUS AND LOW PRESSURE BEGINS TO PUSH EASTWARD
ACROSS THE GREAT LAKES. WARMER TEMPERATURES MOVING IN AS WELL AS
WINDS KEEPING UP OVERNIGHT WILL LIKELY KEEP TEMPERATURES IN THE
UPPER 20S FOR THE MOST PART.
SURFACE GRADIENT WILL TIGHTEN FURTHER ON SATURDAY AS THE LOW
PASSES TO OUR NORTH WHICH WILL PROVIDE BREEZY SOUTHWEST WINDS AND
A RATHER MILD DAY. TEMPERATURES WILL LIKELY TOP OUT IN THE MIDDLE
40S ACROSS THE NORTH TO THE LOWER 50S ACROSS THE SOUTH.
A DEEP UPPER TROUGH BEGINS TO DIG SOUTH INTO OUR REGION SATURDAY
NIGHT AS THE SURFACE LOW REACHES THE EASTERN GREAT LAKES. AS THIS
OCCURS...AN ARCTIC COLD FRONT WILL ARRIVE AT OUR DOORSTEP. SOME
LIGHT PRECIPITATION IN THE FORM OF SNOW SHOWERS LOOKS
POSSIBLE BEHIND THIS FRONT...ESPECIALLY ACROSS THE NORTHERN
PORTIONS OF THE FORECAST AREA. BEHIND THIS STRONG COLD
FRONT...BREEZY NORTHWEST WINDS WILL BRING MUCH COLDER AND DRIER
AIR ACROSS THE REGION SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
WEAK SHORT WAVES WILL BRING A SLIGHT CHANCE FOR SNOW SHOWERS ON
MONDAY AND AGAIN ON TUESDAY NIGHT. OTHERWISE...PRECIPITATION IS
NOT EXPECTED IN THE MODIFIED ARCTIC AIRMASS.
ABOVE NORMAL HIGHS ARE EXPECTED FOR SATURDAY IN A BRIEF ROUND OF
WARM ADVECTION AND SOLAR HEATING. IN THE COLDER AIRMASS THAT WILL BE
AROUND FOR THE REST OF THE PERIOD...TEMPERATURES WILL BE WELL BELOW
NORMAL. TUESDAY MAY BE THE COLDEST DAY...WITH HIGHS NOT FORECAST TO
REACH 20 IN MOST LOCATIONS.
&&
.AVIATION /10Z THURSDAY THROUGH MONDAY/...
A WEAKENING FRONTAL BOUNDARY WILL PUSH DOWN ACROSS THE REGION
THROUGH THIS MORNING. AS IT DOES...A SC FIELD WILL OVERSPREAD THE
TAF SITES OVER THE NEXT FEW HOURS. THE SOUTHERN EDGE OF THIS IS
STILL VFR...BUT WE WILL LIKELY SEE SOME MVFR CIGS DEVELOP THROUGH
DAYBREAK...ESPECIALLY AT THE NORTHERN TAF SITES. DRIER AIR WILL
WORK IN FROM THE NORTHWEST THROUGH MID TO LATE MORNING. THIS
SHOULD ALLOW LOWER CLOUDS TO SCATTER OUT WITH VFR CONDITIONS
EXPECTED THROUGH THE REMAINDER OF THE TAF PERIOD.
OUTLOOK...NO SIGNIFICANT WEATHER IS EXPECTED.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...LATTO
NEAR TERM...LATTO
SHORT TERM...LATTO
LONG TERM...CONIGLIO
AVIATION...JGL
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
330 AM EST THU JAN 17 2013
.SYNOPSIS...
CLOUD COVER WILL CONTINUE FOR MUCH OF TODAY AS THE OHIO VALLY
RESIDES BETWEEN LOW PRESSURE TO THE SOUTH...AND HIGH PRESSURE TO
THE WEST. THE HIGH WILL BUILD EASTWARD TONIGHT...BRINGING THE AREA
A PERIOD OF SEASONABLE TEMPERATURES AND FAIR WEATHER THROUGH
SATURDAY. SOME SNOW SHOWERS WILL BECOME POSSIBLE SATURDAY NIGHT AS
AN ARCTIC AIRMASS BEGINS TO MOVE INTO OUR REGION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...A
AMPLE CLOUD COVER EXTENDS ACROSS THE AREA UNDER A DENSE HIGH CLOUD
CANOPY ASSOCIATED WITH A STRONG UPPER LEVEL JET. PATCHES OF LOW
CLOUDS ARE ALSO OCCURRING UNDER THIS DECK PRIMARILY ASSOCIATED WITH
MOIST LOW LEVEL NORTHERLY FLOW. MODELS ARE IN DISAGREEMENT ON HOW
TO HANDLE THIS LOW LEVEL MOISTURE AS WE GO THROUGH THE DAY. THE
HIGH CLOUDS WILL GRADUALLY SHIFT EAST AS THE JET MAX EXITS OUR
REGION TODAY. THE RAP INDICATES THAT MUCH OF THE LOW CLOUD COVER
WILL CONTINUE THROUGHOUT THE DAY. THE NAM SUGGESTS CLEARING THIS
AFTERNOON. FOLLOWING THE PERSISTENT TREND FOR THE PAST SEVERAL
DAYS...WILL BE PESSIMISTIC ABOUT CLEARING TODAY. THIS WILL RESULT
IN HIGH TEMPERATURES PEAKING IN THE MIDDLE 30S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
A WEAK COLD FRONT WILL PASS ACROSS THE AREA TONIGHT. THIS FRONT
WILL BE MOISTURE STARVED SO KEPT ANY MENTION OF FLURRIES...THAT
HI RES MODELS ARE SUGGESTING...OUT OF THE FORECAST. HIGH PRESSURE
WILL BEGIN TO BUILD BEHIND THIS WEAK FRONT LATE TONIGHT AND INTO
THE DAY FRIDAY. THIS SHOULD FINALLY PROVIDE FOR SOME CLEARING
SKIES...ESPECIALLY ACROSS THE SOUTH AND CLOSER TO THE RIDGE
CENTER. TEMPERATURES WILL REMAIN GENERALLY SEASONABLE THURSDAY
NIGHT AND FRIDAY.
BY FRIDAY NIGHT SOME RETURN FLOW WILL DEVELOP WITH THE LOW LEVEL
PRESSURE GRADIENT INCREASING AS THE RIDGE SHIFTS ACROSS THE
SOUTHEASTERN CONUS AND LOW PRESSURE BEGINS TO PUSH EASTWARD
ACROSS THE GREAT LAKES. WARMER TEMPERATURES MOVING IN AS WELL AS
WINDS KEEPING UP OVERNIGHT WILL LIKELY KEEP TEMPERATURES IN THE
UPPER 20S FOR THE MOST PART.
SURFACE GRADIENT WILL TIGHTEN FURTHER ON SATURDAY AS THE LOW
PASSES TO OUR NORTH WHICH WILL PROVIDE BREEZY SOUTHWEST WINDS AND
A RATHER MILD DAY. TEMPERATURES WILL LIKELY TOP OUT IN THE MIDDLE
40S ACROSS THE NORTH TO THE LOWER 50S ACROSS THE SOUTH.
A DEEP UPPER TROUGH BEGINS TO DIG SOUTH INTO OUR REGION SATURDAY
NIGHT AS THE SURFACE LOW REACHES THE EASTERN GREAT LAKES. AS THIS
OCCURS...AN ARCTIC COLD FRONT WILL ARRIVE AT OUR DOORSTEP. SOME
LIGHT PRECIPITATION IN THE FORM OF SNOW SHOWERS LOOKS
POSSIBLE BEHIND THIS FRONT...ESPECIALLY ACROSS THE NORTHERN
PORTIONS OF THE FORECAST AREA. BEHIND THIS STRONG COLD
FRONT...BREEZY NORTHWEST WINDS WILL BRING MUCH COLDER AND DRIER
AIR ACROSS THE REGION SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
WEAK SHORT WAVES WILL BRING A SLIGHT CHANCE FOR SNOW SHOWERS ON
MONDAY AND AGAIN ON TUESDAY NIGHT. OTHERWISE...PRECIPITATION IS
NOT EXPECTED IN THE MODIFIED ARCTIC AIRMASS.
ABOVE NORMAL HIGHS ARE EXPECTED FOR SATURDAY IN A BRIEF ROUND OF
WARM ADVECTION AND SOLAR HEATING. IN THE COLDER AIRMASS THAT WILL BE
AROUND FOR THE REST OF THE PERIOD...TEMPERATURES WILL BE WELL BELOW
NORMAL. TUESDAY MAY BE THE COLDEST DAY...WITH HIGHS NOT FORECAST TO
REACH 20 IN MOST LOCATIONS.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
A WEAKENING FRONTAL BOUNDARY WILL PUSH DOWN ACROSS THE REGION
THROUGH THIS MORNING. AS IT DOES...A SC FIELD WILL OVERSPREAD THE
TAF SITES OVER THE NEXT FEW HOURS. THE SOUTHERN EDGE OF THIS IS
STILL VFR...BUT WE WILL LIKELY SEE SOME MVFR CIGS DEVELOP THROUGH
DAYBREAK...ESPECIALLY AT THE NORTHERN TAF SITES. DRIER AIR WILL
WORK IN FROM THE NORTHWEST THROUGH MID TO LATE MORNING. THIS
SHOULD ALLOW LOWER CLOUDS TO SCATTER OUT WITH VFR CONDITIONS
EXPECTED THROUGH THE REMAINDER OF THE TAF PERIOD.
OUTLOOK...NO SIGNIFICANT WEATHER IS EXPECTED.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...LATTO
NEAR TERM...LATTO
SHORT TERM...LATTO
LONG TERM...CONIGLIO
AVIATION...JGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
528 PM EST THU JAN 17 2013
.SYNOPSIS...
AN ARCTIC FRONTAL BOUNDARY WILL SAG INTO NORTHERN PENNSYLVANIA
THIS EVENING. AT THE SAME TIME...A DEVELOPING STORM WILL PASS
JUST TO THE SOUTH OF THE STATE. AFTER A COLD DAY ON FRIDAY...
TEMPERATURES WILL MODERATE A BIT ON SATURDAY BEFORE A SHOT OF MUCH
COLDER AIR ARRIVES SUNDAY. TEMPERATURES WILL DIP TO NEAR OR BELOW
ZERO IN PARTS OF THE AREA NEXT WEEK AS THE COLDEST AIR OF THE
SEASON MOVES IN.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
5 PM UPDATE...
THICK...MULTI-LAYERED CLOUD SHIELD CONTINUES TO STREAM NE OVER
THE AREA FROM THE DEVELOPING WAVE OVER THE SERN US. NRN EDGE OF
THE PRECIP IS ACROSS SRN WVA AND NRN VA /JUST SOUTH OF THE D.C.
AREA/. HRRR AND 4KM NAM SHOWS THE NRN EDGE OF THE PRECIP REMAINING
STATIONARY THEN SAGGING SLOWLY SOUTH AND EAST THROUGH THIS
EVENING. THIS AGREES WITH THE LATEST TRENDS ON THE KLWX 88D.
MAIN CONCERN FOR THIS EVENING FOR ANY MEASURABLE PRECIP WILL BE
INVOF A SLOW MOVING EAST/WEST ARCTIC BOUNDARY DRAPED ACROSS
SOUTHERN NEW YORK. SOME VERY WEAK...AND FLEETING ISENTROPIC LIFT
NEAR THE 275K THETA SFC /AHEAD OF A WEAK WAVE OF LOW PRESSURE
ALONG THE BOUNDARY/ WILL SUPPORT AN AREA OF LIGHT SNOW POSSIBLY
DRIFTING SOUTH OF THE PENN/NY BORDER. A LIGHT COATING OF SNOW IS
POSSIBLE NEAR AND TO THE NORTH OF ROUTE 6. THIS FRONT WILL
FOLLOWED BY SOME LAKE EFFECT SNOW SHOWERS ACRS NWRN PENN BY
MIDNIGHT. THE SNOW SHOWERS SHOULD CONTINUE INTO FRIDAY MORNING.
STRATO CU CLOUD TEMPS BENEATH THE SUBSIDENCE INVERSION /THAT WILL
BRIEFLY POKE UP TO AROUND 7-8 KFT AGL THIS EVENING/ WILL BE
IN THE FAVORABLE DENDRITIC GROWTH ZONE...SO SOME NARROW SNOW BANDS
COULD DROP A QUICK INCH OR TWO NEAR AND TO THE WEST OF KBFD.
ELSEWHERE ACROSS THE CENTRAL MTNS AND SUSQ VALLEY REGION...NOTHING
MORE THAN SOME FLURRIES ARE POSSIBLE.
TEMPS THIS EVENING WILL VARY FROM THE MID AND UPPER 20S ALONG THE
PA/NY BORDER...TO THE LOWER AND MID 30S THROUGHOUT THE CENTRAL AND
SOUTHERN VALLEYS.
LOWS TONIGHT WILL BE VERY NEAR TO SLIGHTLY BELOW NORMAL.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
LATEST GUIDANCE STILL KEEPS THE SRN STREAM SYSTEM ROLLING TO THE
EAST-NORTHEAST...KEEPING THE THREAT OF PRECIP SOUTH OF THE MASON-
DIXON LINE. THE WAVE IS MADE TO DEEPEN OFF SHORE FRIDAY AS IT
SPEEDS AWAY...BEING REPLACED BY A STRONG HIGH FROM THE TN VALLEY.
CLEARING IS POSSIBLE ON FRIDAY AS THE ADVECTION CHANGES SIGN IN
THE AFTN...AND WE SEE THE ARCTIC AIR BEAT A QUICK RETREAT OFF TO
THE NORTHEAST AS THE FLOW GOES SW ON THE BACK SIDE OF THE HIGH.
DESPITE THE WARM ADVECTION THAT IS EXPECTED TO DEVELOP DURING THE
DAY...HIGHS IN THE 20S AND 30S WILL STILL AVERAGE WELL BELOW
NORMAL.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
SFC HIGH PRES WILL SLIDE ENEWD FROM THE TN VLY INTO THE SRN MID ATLC
FRIDAY EVENING BEFORE EXPANDING ACRS THE SE STATES INTO SATURDAY.
A STRONG AND RELATIVELY MILD SWLY LLVL FLOW /40-50KT LLJ/ IN-BTWN
THE AFOREMENTIONED SFC HIGH AND CLIPPER LOW CROSSING THE UPPER GRT
LKS WILL PRODUCE STG LOW-MID LVL WAA...PUSHING 850MB TEMPS ABV 0C
IN MOST AREAS ON SAT. THIS SHOULD RESULT IN A BRIEF WARM-UP ON
SATURDAY WITH HIGHS PROJECTED TO CLIMB SEVERAL DEGREES ABV NORMAL.
H5 SHORTWAVE TROUGH AND ASSOCD CLIPPER SFC LOW WILL TRACK EWD ACRS
SRN ONTARIO INTO THE ST. LAWRENCE RIVER VALLEY SAT NGT INTO EARLY
SUNDAY. MODELS REMAIN IN GOOD AGREEMENT IN PLOWING AN ARCTIC FRONT
SEWD ACRS THE CWA EARLY SUNDAY WITH TEMPS ALOFT PLUMMETING TO -10
TO -15C AT 850MB BY 00Z MONDAY. THE POTNL MAY EXIST FOR HIGH
IMPACT SUB-ADVY /HISA/ SNOW SQUALLS WITH THE ARCTIC FROPA...WHICH
COULD CAUSE RAPID WHITE-OUT CONDS. SOME LAKE EFFECT SNOW SHOWERS
ARE ALSO POSSIBLE OVER THE NW MTNS.
*THE NDFD WEB GRAPHICS SHOW "HEAVY SNOW" FOR SAT NGT/EARLY SUNDAY.
WE ARE NOT EXPECTING HEAVY SNOW IN A LITERAL SENSE...BUT HAVE
INSERTED +SW /HEAVY SQUALLS/ INTO THE GRIDS WHICH GETS TRANSLATED
INTO HEAVY SNOW ON THE NDFD WEB GRAPHICS.* HEAVY SNOW SQUALLS
PRODUCE INTENSE BURSTS OF SNOW WITH ACCUMS GENERALLY LESS THAN 1"
OVER A SHORT DURATION.
MEDIUM RANGE MODEL AND ENSEMBLE GUIDANCE REMAINS IN VERY GOOD
AGREEMENT IN DEPICTING A DEEP TROUGH OVER THE ERN U.S....WITH A
VERY COLD POLAR VORTEX /-40C AT 500MB/ SITUATED OVER HUDSON BAY.
THE STRONG COLD SIGNAL IN THE LARGE SCALE PATTERN WILL SUPPORT
HIGH CONFIDENCE IN BELOW NORMAL TEMPERATURES THROUGH THE PERIOD.
PRELIM DAY 4-7 MAX/MIN TEMPS WERE DERIVED USING AN EVEN BLEND OF
17/00Z HPC/NAEFS/GFS/ECMWF MOS DATA. INITIAL VERIFICATION OF THE
EXPERIMENTAL 00Z ECMWF MOS DATA HAS SHOWN INCREASED SKILL OVER THE
GFS-BASED GUIDANCE AT THIS RANGE...AND IS NOTABLY COLDER EARLY NEXT
WEEK WHEN TEMPS SHOULD REACH THEIR BOTTOM...WITH -20C AIR AT H85.
FINAL AFTN TEMPS WERE NUDGED TOWARD THE 12Z GMOS WHICH RESULTED
IN ONLY MINOR CHANGES TO PRELIM FCST.
THE WELL-ADVERTISED MODIFIED ARCTIC OUTBREAK WILL DELIVER THE
COLDEST AIR OF THE SEASON TO THE AREA...ARRIVING ON SCHEDULE AS WE
ENTER THE HEART OF CLIMATOLOGICAL WINTER. THE UPPER LEVEL RIDGE IN
THE WEST IS PROJECTED TO BREAK-DOWN BY THE END OF THE PERIOD...AND
SHOULD ALLOW FOR SOME MODERATION INTO THE SECOND HALF OF NEXT WEEK.
THE GFS REMAINS SLIGHTLY FASTER THAN THE NON-NCEP GUID IN LIFTING
THE BASE OF THE ERN TROUGH NWD AT DAY 7-8. PRECIPITATION DURING THE
PERIOD WILL BE LIMITED/CONFINED MAINLY TO THE WESTERN HIGH
TERRAIN...WITH WEAK CLIPPERS REINFORCING THE COLD NWLY FLOW.
&&
.AVIATION /22Z THURSDAY THROUGH TUESDAY/...
MVFR CIGS WILL CONTINUE OVER MAINLY THE NORTHWEST MOUNTAINS
TONIGHT. KJST AND VCNTY WILL LIKELY SEE VFR FOR THE FIRST HALF OF
TONIGHT...FOLLOWED BY MVFR CIGS LATE.
LAKE MOISTURE CLIMBING THE HIGH TERRAIN OF THE NORTHWEST WILL
KEEP THE CHANCE OF SNOW SHOWERS AND LOCALLY REDUCED CONDITIONS IN
THE PICTURE INTO AT LEAST MID DAY FRIDAY...WITH IMPROVEMENT
EXPECTED BY FRIDAY AFTERNOON AND EVENING AS WINDS TURN MORE
SOUTHWESTERLY ON THE BACK SIDE OF A RETREATING HIGH.
OUTLOOK...
FRI...AM -SHSN/MVFR CIGS POSS W MTNS.
SAT...NO SIG WX EXPECTED.
SUN-TUE...SHSN/MVFR POSS W MTNS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/LAMBERT
NEAR TERM...LA CORTE/LAMBERT
SHORT TERM...LA CORTE
LONG TERM...STEINBUGL
AVIATION...LA CORTE/LAMBERT
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1001 AM EST THU JAN 17 2013
.SYNOPSIS...
A WEAK COLD FRONT WILL PRESS IN FROM THE NORTHWEST TODAY. AT THE
SAME TIME...A STORM SYSTEM WILL PASS JUST TO THE SOUTH OF THE
STATE. AFTER A COLD DAY ON FRIDAY...TEMPERATURES WILL MODERATE A
BIT ON SATURDAY BEFORE MUCH COLDER AIR ARRIVES SUNDAY.
TEMPERATURES WILL DIP TO NEAR OR BELOW ZERO IN PARTS OF THE AREA
NEXT WEEK AS THE COLDEST AIR OF THE SEASON MOVES IN.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
10 AM UPDATE...
THICK CLOUD COVER CONTINUES TO STREAM NE OVER THE AREA FROM THE
DEVELOPING WAVE OVER THE SERN US. NRN EDGE OF THE PRECIP JUST
MAKING INTO SOUTHERN DELAWARE...SHOULD REMAIN SOUTH OF THE BORDER
TODAY.
ELSEWHERE OVER THE NW SOME PATCHY FREEZING DRIZZLE IS POSSIBLE
OVER SOME OF THE RIDGES...OTHERWISE NOTHING MORE THAN A FEW
SCATTERED LIGHT SNOW SHOWERS WILL OCCUR.
THE ABUNDANCE OF CLOUDS AND THE COLD AIR ADVECTION TODAY WILL
CAUSE TEMPS TO STAY RATHER STEADY OVER MUCH OF THE AREA...AND EVEN
DROP A FEW DEGS IN THE NWRN THIRD OF THE AREA.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
GFS AND NAM KEEP THE SRN STREAM SYSTEM ROLLING TO THE EAST AND
NEVER REALLY THREATEN OUR SERN COS WITH PRECIP. ECMWF AND ONE OR
TWO MEMBERS OF THE GEFS STILL NUDGE VERY LIGHT PRECIP INTO THE
EXTREME SE...WHICH IS JUST ENOUGH TO KEEP A 20 POP THERE FOR THE
EVENING. BUT THEN THE WAVE DEEPENS OFF SHORE AND PULLS IN THE COLD
AIR FOR FRIDAY. CLEARING IS POSSIBLE ON FRIDAY AS THE ADVECTION
CHANGES SIGN IN THE AFTN...RAISING THE 8H TEMPS 10C IN JUST
3-4HRS. THE NW FLOW ALOFT KEEPS IT ACTIVE AND UNSETTLED THROUGH
THE PERIOD. THE 1035MB HIGH OFF TO OUR SOUTH AND 8H TEMPS RISING
INTO THE BLACK ON SAT WILL MAKE IT VERY LIKELY THAT WE WILL
ECLIPSE NORMAL MAXES BY 5 TO 10F ON SAT.
THE MOST INTERESTING PERIOD OF THE ENTIRE FORECAST IS SAT NIGHT
AND SUNDAY MORNING. TIMING OF A VERY STRONG/RAPID CHANGE IN AIR
MASS IS FAIRLY CONSISTENT AMONG THE NUMERICAL GUIDANCE. THE FRONT
WILL BLOW THROUGH SOMETIME AROUND OR AFTER MIDNIGHT IN THE NW AND
SHORTLY AFTER SUNRISE IN THE SE. THIS SORT OF SET UP IS VERY
FAVORABLE FOR INTENSE SNOW SHOWERS/SQUALLS. HOWEVER...THE
EXPECTED NIGHTTIME PASSAGE COULD LESSEN THE INTENSITY OF ANY
SQUALLS WITHOUT THE MODEST INCREASE IN INSTABILITY/MIXING POSSIBLE
DURING THE DAYLIGHT HOURS. ANOTHER POSITIVE THING IS THAT IT
SHOULD OCCUR IN THE OVERNIGHT AND NOT EVEN ON A SCHOOL/WORK-DAY
MORNING. HAVE CONTINUED THE MENTION OF THE POSSIBILITY OF SQUALLS
IN THE HWO...DUE TO THE POTENTIAL TRAVEL IMPACT RATHER THAN ANY
HARD AND FAST SNOW OR ICE CRITERIA. TEMPS DROP BACK ON SUNDAY TO
5 OR 10F BELOW NORMALS. HAVE ALLOWED FOR JUST A FEW DEG RISE IN
TEMPS...BUT IT COULD BE ANOTHER STEADY OR SLIGHT DROP DURING THE
DAYLIGHT HRS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
THE PATTERN LOOKS COLD HEADING INTO NEXT WEEK WITH HIGH
CONFIDENCE IN BELOW NORMAL TEMPERATURES. ASIDE FROM OCNL LAKE
EFFECT SNOW SHOWERS AND SCT FLURRIES...PRECIPITATION SHOULD BE
HARD TO COME BY WITH VERY DRY MODIFIED ARCTIC AIR PERSISTING THRU
THE END OF THE PD.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
A SURGE OF HIGHER MOISTURE AHEAD OF APPROACHING COLD FRONT WILL
ASCEND THE W MTNS...PRODUCING A PERIOD OF IFR CIGS AT BFD AND JST
EARLY THIS AM. ACROSS THE RIDGE/VALLEY REGION...MVFR CIGS BEING
REPORTED AT AOO/UNV/IPT AT 11Z.
COLD FRONT WILL PUSH THRU CENTRAL PA LATER THIS MORNING...USHERING
IN A DRIER AIR MASS AND RISING CIGS. LATEST RAP LOW LVL MOISTURE
FIELDS SUGGEST BFD WILL RISE TO MVFR CIGS BTWN 12Z-13Z AND JST
WILL FOLLOW BY ARND 14Z. IN THE WAKE OF THE FRONT...MOISTURE FROM
LK ERIE WILL ASCEND THE NW MTNS...LIKELY RESULTING IN MVFR CIGS
PERSISTING AT BFD UNTIL AT LEAST MID AFTN. FURTHER
SOUTH...SOUNDINGS SUGGEST THE POSSIBILITY OF LINGERING MVFR CIGS
AT JST/UNV/AOO THRU ARND MIDDAY. HOWEVER...DOWNSLOPING FLOW ACROSS
THE SUSQ VALLEY SHOULD ENSURE VFR CONDS AT MDT AND LNS THROUGH
TODAY.
OUTLOOK...
FRI...AM -SHSN/MVFR CIGS POSS W MTNS.
SAT...NO SIG WX EXPECTED.
SUN-MON...SHSN/MVFR POSS W MTNS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO/LA CORTE
NEAR TERM...DANGELO/LA CORTE
SHORT TERM...DANGELO
LONG TERM...STEINBUGL
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
641 AM EST THU JAN 17 2013
.SYNOPSIS...
A WEAK COLD FRONT WILL PRESS IN FROM THE NORTHWEST TODAY. AT THE
SAME TIME...A STORM SYSTEM WILL PASS JUST TO THE SOUTH OF THE
STATE. AFTER A COLD DAY ON FRIDAY...TEMPERATURES WILL MODERATE A
BIT ON SATURDAY BEFORE MUCH COLDER AIR ARRIVES SUNDAY.
TEMPERATURES WILL DIP INTO THE SINGLE DIGITS IN PARTS OF THE AREA
NEXT WEEK AS THE COLDEST AIR OF THE SEASON MOVES IN.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
6 AM...
TEMPS STILL AROUND 40 ALONG THE SRN BORDER...BUT WIND HAS VEERED
SLIGHTLY. THE HIGH CLOUDS ARE THICK ENOUGH TO MAKE VIRGA SEEN ON
THE RADAR AND REMARKED IN OBS AT KMDT. LOW CLOUDS COVER MOST OF
THE AREA NOW. A COLD FRONT IS DROPPING ACROSS THE LOWER GREAT
LAKES AND WILL TURN THE WINDS MORE NORTHERLY SOON. ENOUGH
FRICTION/MOISTURE FLUX WILL CREATE SHSN IN THE NW...BUT ANY ACCUMS
SHOULD STAY IN THE SNOW BELT THIS MORNING OR EARLY AFTN. A FEW
FLURRIES COULD GET OFF THE ALLEGHENIES...BUT WILL NOT MENTION MUCH
S OR E OF CLEARFIELD AND WELLSBORO. THE ABUNDANCE OF CLOUDS AND
THE COLD AIR ADVECTION TODAY WILL CAUSE TEMPS TO STAY RATHER
STEADY OVER MUCH OF THE AREA...AND EVEN DROP A FEW DEGS IN THE
NWRN THIRD OF THE AREA.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
GFS AND NAM KEEP THE SRN STREAM SYSTEM ROLLING TO THE EAST AND
NEVER REALLY THREATEN OUR SERN COS WITH PRECIP. ECMWF AND ONE OR
TWO MEMBERS OF THE GEFS STILL NUDGE VERY LIGHT PRECIP INTO THE
EXTREME SE...WHICH IS JUST ENOUGH TO KEEP A 20 POP THERE FOR THE
EVENING. BUT THEN THE WAVE DEEPENS OFF SHORE AND PULLS IN THE COLD
AIR FOR FRIDAY. CLEARING IS POSSIBLE ON FRIDAY AS THE ADVECTION
CHANGES SIGN IN THE AFTN...RAISING THE 8H TEMPS 10C IN JUST
3-4HRS. THE NW FLOW ALOFT KEEPS IT ACTIVE AND UNSETTLED THROUGH
THE PERIOD. THE 1035MB HIGH OFF TO OUR SOUTH AND 8H TEMPS RISING
INTO THE BLACK ON SAT WILL MAKE IT VERY LIKELY THAT WE WILL
ECLIPSE NORMAL MAXES BY 5 TO 10F ON SAT.
THE MOST INTERESTING PERIOD OF THE ENTIRE FORECAST IS SAT NIGHT
AND SUNDAY MORNING. TIMING OF A VERY STRONG/RAPID CHANGE IN AIR
MASS IS FAIRLY CONSISTENT AMONG THE NUMERICAL GUIDANCE. THE FRONT
WILL BLOW THROUGH SOMETIME AROUND OR AFTER MIDNIGHT IN THE NW AND
SHORTLY AFTER SUNRISE IN THE SE. THIS SORT OF SET UP IS VERY
FAVORABLE FOR INTENSE SNOW SHOWERS/SQUALLS. HOWEVER...THE
EXPECTED NIGHTTIME PASSAGE COULD LESSEN THE INTENSITY OF ANY
SQUALLS WITHOUT THE MODEST INCREASE IN INSTABILITY/MIXING POSSIBLE
DURING THE DAYLIGHT HOURS. ANOTHER POSITIVE THING IS THAT IT
SHOULD OCCUR IN THE OVERNIGHT AND NOT EVEN ON A SCHOOL/WORK-DAY
MORNING. HAVE CONTINUED THE MENTION OF THE POSSIBILITY OF SQUALLS
IN THE HWO...DUE TO THE POTENTIAL TRAVEL IMPACT RATHER THAN ANY
HARD AND FAST SNOW OR ICE CRITERIA. TEMPS DROP BACK ON SUNDAY TO
5 OR 10F BELOW NORMALS. HAVE ALLOWED FOR JUST A FEW DEG RISE IN
TEMPS...BUT IT COULD BE ANOTHER STEADY OR SLIGHT DROP DURING THE
DAYLIGHT HRS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
THE PATTERN LOOKS COLD HEADING INTO NEXT WEEK WITH HIGH
CONFIDENCE IN BELOW NORMAL TEMPERATURES. ASIDE FROM OCNL LAKE
EFFECT SNOW SHOWERS AND SCT FLURRIES...PRECIPITATION SHOULD BE
HARD TO COME BY WITH VERY DRY MODIFIED ARCTIC AIR PERSISTING THRU
THE END OF THE PD.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
A SURGE OF HIGHER MOISTURE AHEAD OF APPROACHING COLD FRONT WILL
ASCEND THE W MTNS...PRODUCING A PERIOD OF IFR CIGS AT BFD AND JST
EARLY THIS AM. ACROSS THE RIDGE/VALLEY REGION...MVFR CIGS BEING
REPORTED AT AOO/UNV/IPT AT 11Z.
COLD FRONT WILL PUSH THRU CENTRAL PA LATER THIS MORNING...USHERING
IN A DRIER AIR MASS AND RISING CIGS. LATEST RAP LOW LVL MOISTURE
FIELDS SUGGEST BFD WILL RISE TO MVFR CIGS BTWN 12Z-13Z AND JST
WILL FOLLOW BY ARND 14Z. IN THE WAKE OF THE FRONT...MOISTURE FROM
LK ERIE WILL ASCEND THE NW MTNS...LIKELY RESULTING IN MVFR CIGS
PERSISTING AT BFD UNTIL AT LEAST MID AFTN. FURTHER
SOUTH...SOUNDINGS SUGGEST THE POSSIBILITY OF LINGERING MVFR CIGS
AT JST/UNV/AOO THRU ARND MIDDAY. HOWEVER...DOWNSLOPING FLOW ACROSS
THE SUSQ VALLEY SHOULD ENSURE VFR CONDS AT MDT AND LNS THROUGH
TODAY.
OUTLOOK...
FRI...AM -SHSN/MVFR CIGS POSS W MTNS.
SAT...NO SIG WX EXPECTED.
SUN-MON...SHSN/MVFR POSS W MTNS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DANGELO
LONG TERM...STEINBUGL
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
102 AM EST THU JAN 17 2013
.SYNOPSIS...
A COLD FRONT WILL CONTINUE TO DRIFT SLOWLY THROUGH THE REGION
INTO TONIGHT. LOW PRESSURE IS FORECAST DEVELOP OVER THE EASTERN GULF
OF MEXICO AND MOVE NORTHEAST ALONG THE FRONT ON THURSDAY. AS THE LOW
MOVES OFF THE NORTH CAROLINA COAST THURSDAY NIGHT...THE WEATHER WILL
BE DRIER AND SEASONABLY COOL FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF MIDNIGHT...COLD WEDGE APPEARS TO BE HOLDING STRONG AND THIS
SHOULD LARGELY INHIBIT WARM AIR ALOFT FROM MAKING MUCH FURTHER PUSH
NORTHWARD INTO THE CWFA. RAP 925MB TEMP PROGS FOR THE REST OF THE
NIGHT SHOW SLIGHT WARMING IN THE COUNTIES NEAR/ALONG OUR SOUTHEAST
BORDER WHILE COLD ADVECTION IS CLEARLY GETTING UNDERWAY OVER THE
MTNS AND NRN NC PIEDMONT. TEMP/DEWPT TRENDS HAVE BEEN REVISED USING
THE RAP SFC TEMPS WHICH WERE IN FAIRLY GOOD AGREEMENT WITH 12 AM
ANALYZED OBS AND AGREE WITH THE 925MB PATTERN.
AS OF 10 PM...OVER THE COURSE OF THE EVENING I HAVE BEEN MONITORING
TRENDS IN THE MODEL GUIDANCE AND UPDATING THE FORECAST ACCORDINGLY.
TWO TRENDS HAVE OCCURRED...GUIDANCE IS WETTER AND SLIGHT QUICKER
WITH COOLING TEMPS LATE TOMORROW AFTERNOON AND EVENING. IN
SHORT...THE POTENTIAL FOR HEAVY SNOW HAS INCREASED ACROSS THE NC
MTNS...REMAINING AROUND THE SAME AS THE PREVIOUS PACKAGE EAST.
LATEST WATER VAPOR IMAGERY INDICATES THAT THE H5 LOW OVER ARKLATX
REGION HAS STARTED TO TRANSITION FROM A POSITIVE TILTED TROUGH TO
MORE NEUTRAL. AHEAD OF THE LOW...A RIBBON OF 1.2 INCH PW EXTENDED
FROM THE YUCATAN PENINSULA ACROSS THE FL PANHANDLE TO THE SOUTHERN
APPALACHIANS. THE PW VALUES ARE NEARLY 200 PERCENT OF NORMAL. AS THE
H5 LOW APPROACHES TONIGHT...A SFC LOW IS EXPECTED TO RAPIDLY DEEPEN
AND ORGANIZE ACROSS CENTRAL GA. AS THE LOW DEEPENS...LLVL FLOW WILL
INCREASE...SUPPORTING A WARM FRONT/WEDGE BOUNDARY ACROSS THE
PIEDMONT OF THE CAROLINAS. NAM12 INDICATES THAT A SW TO NE BAND OF
925-850MB FRONTOGENESIS WILL DEVELOP DURING THE PRE DAWN HOURS. IN
ADDITION...H7 QG UPWARD VERTICAL VELOCITIES WILL INCREASE TO NEAR 15
MBS/HR. THE COMBINATION OF RICH MOISTURE AND DEEPENING LIFT WILL
SUPPORT THE DEVELOPMENT OF A BAND OF MODERATE RAIN ACROSS THE
FOOTHILLS AND PIEDMONT LATE TONIGHT. TEMPERATURES MAY SLOWLY RISE OR
REMAIN STEADY OVERNIGHT...UNDER WAA ALOFT. PRECIP WILL FALL AS RAIN.
POPS WERE INCREASE OVERNIGHT.
DYNAMICS ACROSS THE SOUTHERN APPALACHIAN REGION WILL INCREASE
SHARPLY AFTER SUNRISE AS THE TILTED LOW PRESSURE SYSTEM BEGINS TO
MOVE EASTWARD. A WIDE DEFORMATION ZONE SHOULD PIVOT OVER THE NC MTNS
THROUGH MID DAY...THEN BEGIN TO SHIFT EAST DURING THE AFTERNOON AND
EVENING. BY 18Z...THE CORE OF H7 QG UPWARD VERTICAL VELOCITIES WILL
RAPIDLY INCREASE TO 40 MBS/HR AND TRACK SE TO NE ACROSS THE MIDDLE
OF THE FORECAST AREA...FRONTOGENESIS PEAKS DURING THIS PERIOD. IN
ADDITION...THE NAM12 INDICATES THAT A BROAD FIELD OF NEGATIVE
SATURATED GEO POTENTIAL VORTICITY WILL DEVELOP AHEAD OF H7
LOW...POSSIBLY SIGNALING THE EXISTENCE OF INSTABILITY. GIVEN THE
ENVIRONMENT AND DURATION OF STRONG FORCING...I UPDATE THE FORECAST
TO INCREASE QPF BY AN INCH...INCREASE POPS TO 100 PERCENT.
TEMPERATURES ARE VERY CHALLENGING...BUT I ADJUST CONTINUOUS COOLING
TREND WITH THE NAM 2M TEMPS. USING THIS APPROACH...PRECIP SHOULD
BEGIN TO TRANSITION TO SN/IP ACROSS THE TN BORDER AFTER 18Z. THE
SNOW LINE WILL ADVANCE TO THE FOOTHILLS BY 0Z.
THE GFS AND NAM INDICATE THAT THE DEFORMATION ZONE WILL REMAIN OVER
THE CWA THROUGH THURS EVENING...MOVING EAST OF THE CWA BY EARLY FRI
MORNING. TEMPERATURES WILL DECREASE STEADILY THROUGH THE PERIOD.
HOWEVER...IT APPEARS THAT ONLY A 3 TO 6 HOUR WINDOW WILL EXIST EAST
OF THE MTNS FOR ACCUMULATING SN...GIVEN THE RAPID DECREASE IN
MOISTURE ALOFT AND FORCING. I HAVE UPDATED THE STORM TOTAL SNOW
FORECAST TO INCREASE SNOWFALL ACROSS THE MTNS BY A COUPLE OF
INCHES...AREAS EAST REMAIN VERY SIMILAR TO THE PREVIOUS FORECAST.
THE WINTER STORM PRODUCTS AND FLOOD WATCH APPEAR TO BE WELL PLACED
AND TIMED.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM FRIDAY/...
AS OF 315 PM WEDNESDAY...A NE TO SW ORIENTED DEEP LAYER FRONTAL
BOUNDARY REMAINS STALLED OVER THE WESTERN CAROLINAS AND NE GA. PW
VALUES ALONG THE BNDRY CONTINUE TO RUN 200 TO 300 PERCENT OF NORMAL.
IN FACT...NESTS MENTIONED THIS MORNING THAT FFC/S SOUNDING THIS
MORNING HAD IT/S 4TH HIGHEST RECORDED JANUARY PW VALUE. SO THAT SAY
THAT THERE IS A SIGNIFICANT AMOUNT OF MOISTURE IN PLACE OVER THE
REGION IS AN UNDERSTATEMENT. A POTENT UPPER LOW OVER ERN TX THIS
EVENING WILL TAKE ON A NEGATIVE TILT AND LIFT ACROSS THE UPSTATE BY
TOMORROW EVENING. THE NUMERICAL MODELS GENERATE VERY HEAVY RAIN WITH
THIS FEATURE. QPF AVERAGES AROUND 3 INCHES OVER MUCH OF THE SRN AND
ERN NC MTNS...THE FOOTHILLS AND THE WESTERN PIEDMONT. CONSIDERING
THE AMAZING AMOUNT OF RAIN SOME MOUNTAIN LOCATIONS HAVE HAD OVER THE
PAST THREE DAYS...THIS EXTRA SHOT OF RAIN IS LIKELY TO CAUSE A
CONSIDERABLE AMOUNT OF STREAM AND RIVER FLOODING. THEREFORE THE
FLOOD WATCH WILL BE EXPANDED ACROSS THE REST OF THE MOUNTAINS AND
FOOTHILLS OF THE WESTERN CAROLINAS AND NORTHEAST GEORGIA. WE COULD
SEE SOME VERY HIGH RAINFALL RATES AS THE WARM CONVEYOR BELT WORKS
ACROSS THE FA DURING THE DAYTIME TMRW. A TSTM ISN/T OUT OF THE
QUESTION. CONSIDERING THE EXPECTED RATES...SOME OF THE FLOODING MAY
BE MORE OF THE FLASH FLOOD VARIETY. IN FACT...I/M STILL DEBATING IF
WE WILL ISSUE THE NEW WATCH AS A FLOOD OR FLASH FLOOD PRODUCT.
THE OTHER CONCERN AS THE LOW PASSES WILL BE SNOWFALL. THE AIRMASS
AHEAD OF THE LOW IS VERY WARM AND MOIST. IT WILL TAKE A WHILE FOR
THE PCPN TO CHANGE OVER TO SNOW. I WOULDN/T EXPECT ANY SNOW TO
DEVELOP UNTIL 18 TO 21 UTC ACROSS THE HIGHER MOUNTAIN ELEVATIONS.
THE SNOW LEVELS WILL THEN QUICKLY DROP AND WORK EASTWARD WITH TIME.
THE SREF PLUME DIAGRAMS ARE SHOWING WINTER STORM CRITERIA SNOWFALL
AT ASHEVILLE AND EVEN AT HICKORY. I HAVE UPGRADED THE WINTER STORM
WATCH TO A WARNING ACROSS MOST OF THE NC MTNS. OVER THE SOUTHWEST
MOUNTAINS THE WARMING WILL BE IN EFFECT FOR ELEVATIONS ABOVE 3500
FEET. BY THE TIME THE SNOW LEVEL MAKES IT TO THE VALLEY FLOORS IN
THOSE AREAS...I EXPECT THE HEAVIEST PCPN WILL HAVE ENDED.
THE NORTHERN MOST PART OF THE UPSTATE AND NE GA HAVE BEEN INCLUDED
IN A WINTER WEATHER ADVISORY FOR TOMORROW NIGHT. ONLY AROUND AN INCH
OF SNOW IS IN THE GRIDS...BUT IF THE NAM/S STRONGER...SLOWER AND
COLDER DEFORMATION ZONE VERIFIES...WE COULD SEE HEAVIER HEAVIER SNOW
IN THESE LOCATIONS IN WELL. I AM MORE CONFIDENT IN THE NAM TONIGHT
AS THE IT AND THE GFS HAVE COME INTO MUCH BETTER AGREEMENT. OVER THE
NORTH CAROLINA ZONES...THE NAM AND MANY SREF MEMBERS INDICATE A
PERIOD OF SNOW ACROSS THE FOOTHILLS AND PIEDMONT DURING THE EVENING
HOURS. A CROSS SECTION THROUGH THE NAM SHOWS A DEEP LAYER NEGATIVE
EPV FROM 00-03 UTC. THIS IMPLIES THE POTENTIAL FOR HEAVY BANDED
PRECIPITATION WHICH WILL HELP TO LOWER SNOW LEVELS. IN FACT...AT
THIS POINT I/D SAY CONFIDENCE IS GOOD THAT PARTS OF THE PIEDMONT
WILL SEE SNOW...THOUGH ACCUMULATING SNOW MAY BE CONFINED TO A NARROW
BAND UNDER THE BEST CSI. THE RALEIGH OFFICE IS THINKING ALONG THE
SAME LINES AND WE HAVE ISSUED A WINTER STORM WATCH FOR THESE AREAS
STARTING AT 21 UTC TOMORROW. EVEN WITH WARM GROUND...HEAVY SNOWFALL
RATES COULD CAUSE TRAVEL CONCERNS AND MAY BREAK SOME LIMBS CAUSING
POWER OUTAGES.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
AS OF 230 PM WEDNESDAY...A BROAD TROUGH WILL BE IN PLACE ACROSS THE
ERN CONUS THROUGH THE WEEKEND AS A SHARP WAVE ROUNDS THE POLAR
VORTEX AND CROSSES THE GREAT LAKES. A COLD FRONT WILL MOVE THROUGH
THE REGION ON SUNDAY...BUT IT SHOULD BE DRY OTHER THAN SHALLOW W TO
NW UPSLOPE FLOW MOISTURE INTO THE WRN MTNS PRODUCING SOME CLOUDS
LATE SUNDAY.
REINFORCING ENERGY WILL DIVE SE THROUGH THE MIDWEST ON MON AND PASS
MAINLY N OF THE FORECAST AREA MON NIGHT THROUGH TUE. BRIEFLY COUPLED
JET DIVERGENCE WILL BE POSSIBLE DURING THE MON NIGHT TIME
FRAME...BUT MOISTURE WILL BE TOO SHALLOW FOR ANYTHING OTHER THAN
SLIGHT CHANCES OF UPSLOPE SNOW SHOWERS IN THE WRN MTNS. REINFORCING
ARCTIC AIR WILL THEN ARRIVE BEHIND THE FRONT EARLY TUE THROUGH
WED...WITH DEEP LAYER NW FLOW THROUGH THE PERIOD ALONG WITH DRY
CONDITIONS.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AT KCLT AND KHKY...THE FIRST 6 HOURS OR SO OF THE PERIOD WILL LIKELY
BE MARKED BY VERY MESSY CONDITIONS...WITH CIGS AND VISBY BOUNCING
BACK AND FORTH BETWEEN VARIOUS FLT CATEGORIES. TOWARD DAYBREAK...
CONDITIONS SHOULD SETTLE INTO THE IFR/LIFR RANGE...AS STRONG LOW
LEVEL LIFT DEVELOPS IN RESPONSE TO STRONG UPPER LEVEL STORM SYSTEM
MOVING OUT OF THE LOWER MISS VALLEY. IN THE INTERIM...ONE AREA OF
LIGHT/MOD RAIN WILL PUSH EAST OF THE TERMINALS BY AROUND 07Z.
HOWEVER...ANOTHER ONE WILL APPROACH BETWEEN 09 AND 10Z. WHILE VISBY
WILL LIKELY IMPROVE IN BETWEEN THESE WAVES OF PRECIP...THE GENERAL
IDEA IS THAT CIGS WILL REMAIN (OR RETURN TO) LIFR. VERY POOR FLT
CONDITIONS ARE EXPECTED TO CONTINUE THROUGH THE DAY. PERIODS OF
HEAVY RAIN ARE EXPECTED DURING THE DAYLIGHT HOURS...LIKELY RESULTING
IN LONG DURATION OF IFR/LIFR VISBY. STRENGTHENING NE WINDS WILL
DEVELOP AS LOW PRESSURE INTENSIFIES TO THE SOUTHWEST...WITH GUSTS IN
THE 20S LIKELY BY AFTERNOON. FINALLY...RAIN IS EXPECTED TO CHANGE TO
SNOW THURSDAY EVENING...WITH LIGHT ACCUMULATIONS POSSIBLE...ESP AT
KHKY.
ELSEWHERE...ONE WAVE OF LIGHT/MOD RAIN HAS SHIFTED EAST OF THE
TERMINALS...BUT ANOTHER WILL MOVE BACK OVER THE AREA BETWEEN 7 AND 9
Z. VISBY IS EXPECTED TO BRIEFLY IMPROVE TO VFR PRIOR TO THE ARRIVAL
OF THE NEXT WAVE. HOWEVER...CIGS ARE A BIT MORE PROBLEMATIC. THE
IMPROVEMENT IN CIGS THAT WAS OBSERVED EARLIER WAS TIED TO THE ONSET
OF PRECIP...AND CIGS MAY VERY WELL RETURN TO LIFR/IFR PRIOR TO THE
ONSET OF PRECIP. CIGS ARE THEN EXPECTED TO BOUNCE AROUND BETWEEN FLT
CATEGORIES UNTIL AROUND SUNRISE...WHEN STRONG LOW LEVEL LIFT
DEVELOPS IN RESPONSE TO STRONG UPPER LEVEL STORM SYSTEM MOVING OUT
OF THE LOWER MISS VALLEY. THIS SHOULD RESULT IN CIGS SETTLING TO THE
IFR/LIFR RANGE...LASTING THROUGH THE DAY. PERIODS OF HEAVY RAIN ARE
EXPECTED DURING THE DAYLIGHT HOURS...LIKELY RESULTING IN LONG
DURATION OF IFR/LIFR VISBY. STRENGTHENING N/NE WINDS WILL DEVELOP AS
LOW PRESSURE INTENSIFIES TO THE SOUTHWEST...WITH GUSTS IN THE 20S
LIKELY BY AFTERNOON.THE OTHER ITEM OF CONCERN IS THAT RAIN WILL
CHANGE TO SNOW AT KAVL BY 00Z. ACCUMULATING SNOWFALL IS LIKELY. THE
UPSTATE TERMINALS MAY ALSO SEE SOME FLAKES AS WELL BEFORE THE PRECIP
ENDS THURSDAY EVENING...BUT LITTLE OR NO ACCUMULATIONS IS
EXPECTED.
OUTLOOK...DRY HIGH PRESSURE WILL BEGIN BUILDING OVER THE REGION
FRIDAY AND WILL REMAIN THROUGH THE WEEKEND.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT THE FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...FLOOD WATCH THROUGH THIS EVENING FOR GAZ010-017-018-026-028.
WINTER WEATHER ADVISORY FROM 1 PM THIS AFTERNOON TO MIDNIGHT
EST TONIGHT FOR GAZ010-017.
NC...FLOOD WATCH THROUGH THIS EVENING FOR NCZ033-035-048>053-058-
059-062>065-501>510.
WINTER STORM WARNING FROM 1 PM THIS AFTERNOON TO MIDNIGHT EST
TONIGHT FOR NCZ033-048>050-052-053-064-065-501>507-509.
WINTER WEATHER ADVISORY FROM 1 PM THIS AFTERNOON TO MIDNIGHT
EST TONIGHT FOR NCZ051-058-059-062-063.
WINTER STORM WARNING FROM 7 AM THIS MORNING TO MIDNIGHT EST
TONIGHT FOR NCZ051-058-059-062-063.
WINTER STORM WATCH FROM THIS AFTERNOON THROUGH LATE TONIGHT
FOR NCZ035>037-056-057-068>072-508-510.
SC...FLOOD WATCH THROUGH THIS EVENING FOR SCZ001>007-010.
WINTER WEATHER ADVISORY FROM 1 PM THIS AFTERNOON TO MIDNIGHT
EST TONIGHT FOR SCZ001>003.
&&
$$
SYNOPSIS...CSH
NEAR TERM...NED/WIMBERLEY
SHORT TERM...MCAVOY
LONG TERM...HG
AVIATION...JDL
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
311 PM CST THU JAN 17 2013
.DISCUSSION.../ISSUED AT 311 PM CST/
WARM FRONT LIFTS NORTH TONIGHT GIVING WAY TO A MILD AND MOSTLY SUNNY
FRIDAY ACROSS THE AREA. FORECAST TONIGHT A BIT TRICKY WITH POTENTIAL
STRATUS ISSUES. MID LEVEL CLOUDS WILL CONTINUE TO STREAM ACROSS OUR
NORTH THROUGH THE NIGHT ASSOCIATED WITH MID LEVEL FRONTAL BOUNDARY.
HOWEVER THINK THE CWA WILL REMAIN DRY...OTHER THAN MAYBE AN ISOLATED
FLURRY ACROSS SOUTHWEST MINNESOTA. AREA OF STRATUS FROM SOUTH OF
SIOUX FALLS INTO EASTERN NEBRASKA CONTINUES TO DISSIPATE UNDER
DAYTIME HEATING. HOWEVER...CURRENT THINKING...BACKED BY THE RAP AND
NAM...IS THAT THIS AREA WILL REFORM AND EXPAND THIS EVENING INTO
TONIGHT. WITH SOUTHERLY BOUNDARY LAYER FLOW THIS WILL THEN EXPAND
AND COULD COVER MUCH OF THE CWA FOR A PERIOD TONIGHT. DRIER BOUNDARY
LAYER MOVING IN FROM THE SOUTHWEST WILL ALLOW THE STRATUS TO CLEAR
FROM SOUTHWEST TO NORTHEAST THROUGH THE NIGHT. COULD BE AREAS OF FOG
AS WELL. BEST CHANCE OF STAYING CLEAR THROUGH THE NIGHT WILL BE WEST
OF SIOUX CITY TO YANKTON UP TOWARDS GREGORY. LOW LEVEL JET INCREASES
TONIGHT...WHICH SHOULD KEEP A SOUTHERLY BREEZE GOING. THE BREEZE
COMBINED WITH POTENTIAL CLOUDS SHOULD KEEP LOWS ON THE WARM SIDE OF
GUIDANCE. GENERALLY AROUND 20 SOUTHWEST MINNESOTA TO LOW AND MID 20S
ELSEWHERE. LOWS WILL PROBABLY BE IN THE EVENING...WITH STEADY OR
RISING TEMPERATURES OVERNIGHT.
ANY STRATUS SHOULD EXIT THE CWA BY AROUND 12Z. COULD BE SOME CIRRUS
OVERHEAD DURING THE DAY...BUT OVERALL EXPECTING A MOSTLY SUNNY DAY.
KEPT HIGHS CLOSE TO THE ECMWF AND ECMWF MOS...AS THEY PERFORMED BEST
ON WEDNESDAY. LOOKING AT LOW AND MID 40S NORTH TO THE LOW AND MID
50S CLOSER TO THE MISSOURI RIVER. WITH 925MB TEMPERATURES
APPROACHING 10C IN OUR SOUTHWEST...WOULD NOT BE SURPRISED IF
SOMEPLACE IN NORTH CENTRAL NEBRASKA...OR ADJACENT AREAS OF GREGORY
AND CHARLES MIX COUNTIES COME CLOSE TO 60. /CHENARD
MAJOR PATTERN CHANGE EXPECTED TO BEGIN ON SATURDAY AS AN ARCTIC
BLAST DROPS SOUTHWARD INTO THE NORTHERN PLAINS. COLD FRONT SLATED TO
PUSH THROUGH THE FORECAST AREA DURING THE DAY...AND THE BIG QUESTION
IS HOW QUICKLY IT WILL ARRIVE. LARGE TEMPERATURE DISCREPANCIES
BETWEEN MODELS FOR SATURDAY HIGHS WITH A STAGGERING NEARLY 30 DEGREE
DIFFERENCE BETWEEN THE WARMEST AND COLDEST MODELS IN SIOUX FALLS.
THE GFS AND NAM ARE THE FASTEST WITH PULLING THE COLDER AIR INTO THE
FORECAST AREA WHILE THE ECMWF AND GEM PAINT A MUCH SLOWER
PROGRESSION AND DEPICT A MILD DAY ACROSS THE CWA. HAVE OPTED FOR A
MIDDLE GROUND SOLUTION WITH MIXING KEEPING TEMPERATURES ON THE
MILDER SIDE. EXPECT THE MISSOURI VALLEY TO REACH NEAR 40 RANGING TO
AROUND 30 AT OUR NORTHERN BORDER.
FRONTAL PASSAGE IS EXPECTED TO BE DRY...BUT STRONG NORTHWEST WINDS
IN ITS WAKE WILL PRODUCE SOME BRUTAL WIND CHILLS. WITH 925MB WINDS
UP AROUND 50 KT AND STRONG COLD AIR ADVECTION...WOULD NOT BE
SURPRISED TO SEE ADVISORY LEVEL WINDS. COLD AIR WILL QUICKLY DROP
SOUTH LATE EVENING INTO THE OVERNIGHT AND LOWS SATURDAY NIGHT WILL
BE IN THE SINGLE DIGITS ABOVE AND BELOW ZERO. WINDS WILL DECREASE ON
SUNDAY AS SURFACE HIGH PRESSURE QUICKLY SHUNTS SOUTHEAST OF THE
REGION...BUT DO NOT EXPECT MUCH RECOVERY OF TEMPERATURES. HIGHS WILL
ONLY BE IN THE SINGLE DIGITS AND TEENS FOR THE MAJORITY OF THE CWA.
A QUICK SHOT OF LIGHT SNOW WILL MOVE SOUTHEAST DURING THE DAY AHEAD
OF A REINFORCING SHOT OF COLD AIR. SNOW WOULD LIKELY BE BRIEF WITH
NOT MUCH MOISTURE TO WORK WITH...HOWEVER THE COLD TEMPERATURES
SHOULD PRODUCE UP TO AN INCH OF FLUFFY SNOW. NORTHERLY WINDS WILL
PICK UP ONCE AGAIN BEHIND THE FRONT AND WOULD DRIFT WHATEVER SNOW
FALLS ON SUNDAY. SUNDAY NIGHT WILL SEE SOME OF THE COLDEST
TEMPERATURES OF THE SEASON SO FAR WITH THE NORTHERN HALF DROPPING
INTO THE TEENS BELOW ZERO. FRIGID TEMPERATURES WILL CONTINUE INTO
MONDAY WITH HIGHS NEAR ZERO IN OUR NORTHEAST.
MODELS KEEP THE LARGE UPPER RIDGE OVER THE INTERMOUNTAIN WEST IN
PLACE INTO TUESDAY...WHICH LEAVES THE FORECAST AREA UNDER COOL
NORTHWEST FLOW. MODELS BRING A WEAK WAVE THROUGH THE FLOW AROUND THE
MONDAY NIGHT TO TUESDAY TIME FRAME...HOWEVER NOT A LOT OF CONFIDENCE
THAT THE CWA WILL SEE MUCH IMPACT. WILL LEAVE THE SLIGHT CHANCES
THAT THE LATEST ALLBLEND PRODUCED FOR NOW. WARMER WEATHER MAY RETURN
ON WEDNESDAY AND THURSDAY WITH THE RIDGE ADVANCING EASTWARD.
&&
.AVIATION.../FOR THE 18Z TAF ISSUANCE/
CURRENTLY SEEING VFR STRATUS OVER MUCH OF THE FORECAST AREA. HOWEVER
BAND OF IFR/LIFR STRATUS CONTINUES TO LINGER FROM YANKTON TO SIOUX
CITY AND SOUTH INTO EASTERN NEBRASKA. WEAK BOUNDARY LAYER FLOW
PREVENTING MUCH MOVEMENT...AND RAP SOUNDINGS SUGGEST DISSIPATION IS
UNLIKELY. THUS NOW THINKING THAT KSUX STAYS STUCK IN THE IFR STRATUS
THROUGH THE DAY AND INTO TONIGHT. WOULD NOT BE SURPRISED IF THE LIFR
CIGS CURRENTLY WEST OF SIOUX CITY POSSIBLY MOVE IN TONIGHT...BUT
WITH LOW CONFIDENCE ON TIMING AND CIG HEIGHT...WILL LEAVE THINGS IFR
FOR NOW. AREA OF MVFR STRATUS OVER NORTH CENTRAL SOUTH DAKOTA IS
BEGINNING TO MOVE BACK INTO OUR NORTHERN AREAS. RAP WOULD SUGGEST
THIS MOVES INTO KHON AND KFSD FOR A PERIOD THIS AFTERNOON..BEFORE
CLOUD LAYER FLOW TURNS SOUTHWESTERLY PUSHING IT BACK NORTH. WILL
HAVE TO MONITOR THIS THOUGH...AS KFSD WILL LIKELY BE RIGHT ON THE
EDGE OF THESE MVFR CIGS. OTHER CONCERN FOR KFSD IS THE IFR/LIFR
STRATUS TO THE SOUTH MENTIONED ABOVE. BASED ON SATELLITE...BELIEVE
THIS AREA IS NOT TOO FAR AWAY. AS BOUNDARY LAYER FLOW TURNS WEAK
SOUTHERLY THINKING THIS MOVES IN LATER THIS AFTERNOON OR EVENING.
THIS IS SHOWN BY THE RAP...WHICH EXPANDS THE CURRENT LOW STRATUS
DECK NORTHWARD...EVENTUALLY POSSIBLY EVEN REACHING KHON. KEPT KFSD
AND KHON AT LOW END MVFR FOR NOW...BUT THINKING A PERIOD OF IFR OR
LIFR IS VERY POSSIBLE TONIGHT...ESPECIALLY AT KFSD. BY LATER
TONIGHT...DRIER AIR WILL WORK IN FROM SOUTHWEST TO NORTHEAST...WITH
ALL TAF SITES BECOMING VFR BY MORNING. /CHENARD
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1150 AM CST THU JAN 17 2013
.DISCUSSION.../ISSUED AT 955 AM CST/
A COUPLE AREAS OF CLOUDS ACROSS THE CWA AT THIS TIME...WITH A SMALL
WINDOW OF CLEARING FROM SIOUX FALLS TO MARSHALL. THINK THIS AREA
WILL GIVE WAY TO INCREASING CLOUDS...AS STRATUS IN CENTRAL SOUTH
DAKOTA MOVES BACK IN. MEANWHILE...THERE IS A SECOND AREA OF LOWER
CLOUDS CLOSER TO THE MISSOURI RIVER...FROM YANKTON TO SIOUX CITY
AND SOUTH DOWN INTERSTATE 29 TOWARDS OMAHA AND LINCOLN NEBRASKA.
WILL HAVE TO WATCH AND SEE WHAT HAPPENS WITH THIS THROUGH THE REST
OF THE MORNING. RAP SUGGESTS IT MAY ACTUALLY EXPAND...AND WITH
BOUNDARY LAYER FLOW BECOMING WEAK SOUTHWESTERLY...IT MAY LINGER
ACROSS OUR NORTHWEST IOWA COUNTIES. AS FAR AS TEMPERATURES
GO...WOULD NOT BE SURPRISED IF AREAS FROM WEST OF YANKTON TO GREGORY
END UP A COUPLE DEGREES WARMER...ESPECIALLY IF IT REMAINS MOSTLY
SUNNY. ALSO...AREAS FROM SIOUX FALLS TO SIOUX CITY AND EAST...MAY
END UP A FEW DEGREES COOLER THAN CURRENT FORECAST IF CLOUDS HANG
AROUND LIKE THE RAP IS SUGGESTING. GIVEN CLOUD COVER
UNCERTAINTY...WILL LEAVE HIGHS ALONE FOR NOW AND ADJUST AS NEED BE
AS CLOUD AND TEMPERATURE TRENDS BECOME MORE APPARENT LATER THIS
MORNING. /CHENARD
.PREVIOUS DISCUSSION.../ISSUED AT 305 AM CST/
A CHILLY START TO THE DAY AS A SHALLOW ARCTIC AIR MASS HAS STALLED
OVER THE EASTERN HALF OF THE CWA. THIS WILL MODIFY THROUGH THE DAY
LEADING TOWARDS HIGH TEMPERATURES A BIT ABOVE NORMAL...BUT NOT AS
WARM AS YESTERDAY. CLOUDS AS WELL AS THE COOLER START WILL BE THE
MAIN REASONS. REGARDLESS...PLANNING ON HIGHS FROM NEAR 40 ALONG THE
MISSOURI RIVER TO THE MID 20S IN SOUTHWEST MINNESOTA.
A STRONG SOUTHERLY PRESSURE GRADIENT WILL DEVELOP OVERNIGHT LEADING
TOWARDS A NON DIURNAL TEMPERATURE PROFILE. LOWS IN MOST SPOTS WILL
OCCUR BETWEEN ABOUT 2Z AND 6Z...THEN RISE AFTER. EXPECTING LOWS IN
THE MID TEENS TO LOWER 20S BUT 12Z FRIDAY TEMPERATURES LIKELY TO BE
BETWEEN 25 AND 30 DEGREES IN MOST LOCATIONS WITH A BIT OF A BREEZY
SOUTH WIND.
THIS WILL LEAD INTO A VERY WARM FRIDAY...ESPECIALLY LOOKING AT WHAT
HAPPENED ACROSS THE AREA TODAY. NOT MUCH INT HE WAY OF CLOUD COVER
AND WINDS TURNING FROM THE SOUTHWEST TO THE WEST AND NORTHWEST
THROUGH THE DAY SUPPORTS MIXY AND MILD CONDITIONS. WITH 925MB
TEMPERATURES WELL INTO THE SINGLE DIGITS...ESPECIALLY SOUTH...HIGHS
SHOULD RANGE FROM THE LOWER 40S NORTH TO 50 TO 55 SOUTH.
MILD WESTERLY FLOW WILL REMAIN IN PLACE THROUGH FRIDAY NIGHT INTO
SATURDAY MORNING AHEAD OF A STRONG PUSH OF COLD AIR. TEMPERATURES
SHOULD ONLY FALL INTO THE 20 TO 25 DEGREE RANGE FRIDAY NIGHT THEN
QUICKLY WARM INTO THE MID 30S TO LOWER 40S ON SATURDAY AHEAD OF THE
COLD FRONT. IF THE FRONT IS JUST A FEW HOURS SLOWER HIGHS WILL
LIKELY BE ANOTHER 5 DEGREES WARMER SO TIMING OF THIS BOUNDARY WILL
BE VERY IMPORTANT. HAVE TEMPERATURES TANKING LATE AFTERNOON AND
EVENING AS THE FRONT BARRELS THROUGH. AT SOME POINT IN TIME MAY NEED
A WIND ADVISORY FOR THE AREA AND POSSIBLY A WIND CHILL ADVISORY IN
THE NORTHERN CWA.
IN THE LATTER PERIODS(SUN/THU)...NOT MUCH IN THE WAY OF CHANGES AS
BELOW NORMAL TEMPERATURES STILL THE MAIN ISSUE. A VERY STRONG RIDGE
WILL BE IN PLACE OVER THE WESTERN UNITED STATES WHICH WILL ALLOW A
NORTHERLY ORIENTED JET TO BE IN PLACE OVER THE NORTHERN PLAINS. THIS
WILL MAKE IT DIFFICULT TO BREAK OUT OF THE COLD AIR DURING THE
PERIOD. WILL CONTINUE THE CHANCE FOR SNOW ON SUNDAY AHEAD OF THE
VERY STRONG COLD FRONT. NOT EXPECTING A LOT OF ACCUMULATION BUT
MIGHT BE ENOUGH TO ADD A LITTLE TO WHAT IS OUT THERE. SUNDAY NIGHT
INTO MONDAY EVENING LIKELY TO BE THE COLDEST 24 HOUR PERIOD THIS
SEASON SO FAR WITH SOME TYPE OF COLD HEADLINE ANTICIPATED. AFTER
THIS MODELS NOT REAL AGREEABLE BUT NOT TERRIBLE. LOOKS LIKE A SLOW
MODERATING TREND THROUGH THE WEEK. /08
&&
.AVIATION.../FOR THE 18Z TAF ISSUANCE/
CURRENTLY SEEING VFR STRATUS OVER MUCH OF THE FORECAST AREA. HOWEVER
BAND OF IFR/LIFR STRATUS CONTINUES TO LINGER FROM YANKTON TO SIOUX
CITY AND SOUTH INTO EASTERN NEBRASKA. WEAK BOUNDARY LAYER FLOW
PREVENTING MUCH MOVEMENT...AND RAP SOUNDINGS SUGGEST DISSIPATION IS
UNLIKELY. THUS NOW THINKING THAT KSUX STAYS STUCK IN THE IFR STRATUS
THROUGH THE DAY AND INTO TONIGHT. WOULD NOT BE SURPRISED IF THE LIFR
CIGS CURRENTLY WEST OF SIOUX CITY POSSIBLY MOVE IN TONIGHT...BUT
WITH LOW CONFIDENCE ON TIMING AND CIG HEIGHT...WILL LEAVE THINGS IFR
FOR NOW. AREA OF MVFR STRATUS OVER NORTH CENTRAL SOUTH DAKOTA IS
BEGINNING TO MOVE BACK INTO OUR NORTHERN AREAS. RAP WOULD SUGGEST
THIS MOVES INTO KHON AND KFSD FOR A PERIOD THIS AFTERNOON..BEFORE
CLOUD LAYER FLOW TURNS SOUTHWESTERLY PUSHING IT BACK NORTH. WILL
HAVE TO MONITOR THIS THOUGH...AS KFSD WILL LIKELY BE RIGHT ON THE
EDGE OF THESE MVFR CIGS. OTHER CONCERN FOR KFSD IS THE IFR/LIFR
STRATUS TO THE SOUTH MENTIONED ABOVE. BASED ON SATELLITE...BELIEVE
THIS AREA IS NOT TOO FAR AWAY. AS BOUNDARY LAYER FLOW TURNS WEAK
SOUTHERLY THINKING THIS MOVES IN LATER THIS AFTERNOON OR EVENING.
THIS IS SHOWN BY THE RAP...WHICH EXPANDS THE CURRENT LOW STRATUS
DECK NORTHWARD...EVENTUALLY POSSIBLY EVEN REACHING KHON. KEPT KFSD
AND KHON AT LOW END MVFR FOR NOW...BUT THINKING A PERIOD OF IFR OR
LIFR IS VERY POSSIBLE TONIGHT...ESPECIALLY AT KFSD. BY LATER
TONIGHT...DRIER AIR WILL WORK IN FROM SOUTHWEST TO NORTHEAST...WITH
ALL TAF SITES BECOMING VFR BY MORNING. /CHENARD
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
955 AM CST THU JAN 17 2013
.DISCUSSION.../ISSUED AT 955 AM CST/
A COUPLE AREAS OF CLOUDS ACROSS THE CWA AT THIS TIME...WITH A SMALL
WINDOW OF CLEARING FROM SIOUX FALLS TO MARSHALL. THINK THIS AREA
WILL GIVE WAY TO INCREASING CLOUDS...AS STRATUS IN CENTRAL SOUTH
DAKOTA MOVES BACK IN. MEANWHILE...THERE IS A SECOND AREA OF LOWER
CLOUDS CLOSER TO THE MISSOURI RIVER...FROM YANKTON TO SIOUX CITY
AND SOUTH DOWN INTERSTATE 29 TOWARDS OMAHA AND LINCOLN NEBRASKA.
WILL HAVE TO WATCH AND SEE WHAT HAPPENS WITH THIS THROUGH THE REST
OF THE MORNING. RAP SUGGESTS IT MAY ACTUALLY EXPAND...AND WITH
BOUNDARY LAYER FLOW BECOMING WEAK SOUTHWESTERLY...IT MAY LINGER
ACROSS OUR NORTHWEST IOWA COUNTIES. AS FAR AS TEMPERATURES
GO...WOULD NOT BE SURPRISED IF AREAS FROM WEST OF YANKTON TO GREGORY
END UP A COUPLE DEGREES WARMER...ESPECIALLY IF IT REMAINS MOSTLY
SUNNY. ALSO...AREAS FROM SIOUX FALLS TO SIOUX CITY AND EAST...MAY
END UP A FEW DEGREES COOLER THAN CURRENT FORECAST IF CLOUDS HANG
AROUND LIKE THE RAP IS SUGGESTING. GIVEN CLOUD COVER
UNCERTAINTY...WILL LEAVE HIGHS ALONE FOR NOW AND ADJUST AS NEED BE
AS CLOUD AND TEMPERATURE TRENDS BECOME MORE APPARENT LATER THIS
MORNING. /CHENARD
.PREVIOUS DISCUSSION.../ISSUED AT 305 AM CST/
A CHILLY START TO THE DAY AS A SHALLOW ARCTIC AIR MASS HAS STALLED
OVER THE EASTERN HALF OF THE CWA. THIS WILL MODIFY THROUGH THE DAY
LEADING TOWARDS HIGH TEMPERATURES A BIT ABOVE NORMAL...BUT NOT AS
WARM AS YESTERDAY. CLOUDS AS WELL AS THE COOLER START WILL BE THE
MAIN REASONS. REGARDLESS...PLANNING ON HIGHS FROM NEAR 40 ALONG THE
MISSOURI RIVER TO THE MID 20S IN SOUTHWEST MINNESOTA.
A STRONG SOUTHERLY PRESSURE GRADIENT WILL DEVELOP OVERNIGHT LEADING
TOWARDS A NON DIURNAL TEMPERATURE PROFILE. LOWS IN MOST SPOTS WILL
OCCUR BETWEEN ABOUT 2Z AND 6Z...THEN RISE AFTER. EXPECTING LOWS IN
THE MID TEENS TO LOWER 20S BUT 12Z FRIDAY TEMPERATURES LIKELY TO BE
BETWEEN 25 AND 30 DEGREES IN MOST LOCATIONS WITH A BIT OF A BREEZY
SOUTH WIND.
THIS WILL LEAD INTO A VERY WARM FRIDAY...ESPECIALLY LOOKING AT WHAT
HAPPENED ACROSS THE AREA TODAY. NOT MUCH INT HE WAY OF CLOUD COVER
AND WINDS TURNING FROM THE SOUTHWEST TO THE WEST AND NORTHWEST
THROUGH THE DAY SUPPORTS MIXY AND MILD CONDITIONS. WITH 925MB
TEMPERATURES WELL INTO THE SINGLE DIGITS...ESPECIALLY SOUTH...HIGHS
SHOULD RANGE FROM THE LOWER 40S NORTH TO 50 TO 55 SOUTH.
MILD WESTERLY FLOW WILL REMAIN IN PLACE THROUGH FRIDAY NIGHT INTO
SATURDAY MORNING AHEAD OF A STRONG PUSH OF COLD AIR. TEMPERATURES
SHOULD ONLY FALL INTO THE 20 TO 25 DEGREE RANGE FRIDAY NIGHT THEN
QUICKLY WARM INTO THE MID 30S TO LOWER 40S ON SATURDAY AHEAD OF THE
COLD FRONT. IF THE FRONT IS JUST A FEW HOURS SLOWER HIGHS WILL
LIKELY BE ANOTHER 5 DEGREES WARMER SO TIMING OF THIS BOUNDARY WILL
BE VERY IMPORTANT. HAVE TEMPERATURES TANKING LATE AFTERNOON AND
EVENING AS THE FRONT BARRELS THROUGH. AT SOME POINT IN TIME MAY NEED
A WIND ADVISORY FOR THE AREA AND POSSIBLY A WIND CHILL ADVISORY IN
THE NORTHERN CWA.
IN THE LATTER PERIODS(SUN/THU)...NOT MUCH IN THE WAY OF CHANGES AS
BELOW NORMAL TEMPERATURES STILL THE MAIN ISSUE. A VERY STRONG RIDGE
WILL BE IN PLACE OVER THE WESTERN UNITED STATES WHICH WILL ALLOW A
NORTHERLY ORIENTED JET TO BE IN PLACE OVER THE NORTHERN PLAINS. THIS
WILL MAKE IT DIFFICULT TO BREAK OUT OF THE COLD AIR DURING THE
PERIOD. WILL CONTINUE THE CHANCE FOR SNOW ON SUNDAY AHEAD OF THE
VERY STRONG COLD FRONT. NOT EXPECTING A LOT OF ACCUMULATION BUT
MIGHT BE ENOUGH TO ADD A LITTLE TO WHAT IS OUT THERE. SUNDAY NIGHT
INTO MONDAY EVENING LIKELY TO BE THE COLDEST 24 HOUR PERIOD THIS
SEASON SO FAR WITH SOME TYPE OF COLD HEADLINE ANTICIPATED. AFTER
THIS MODELS NOT REAL AGREEABLE BUT NOT TERRIBLE. LOOKS LIKE A SLOW
MODERATING TREND THROUGH THE WEEK. /08
&&
.AVIATION.../FOR THE 12Z TAF ISSUANCE/
APPEARS TO BE MANY CLOUD LAYERS AT VARYING HEIGHTS ACROSS THE REGION
AT THE START OF THE PERIOD. PRIMARY TO AVIATION CONCERNS IS IFR-LIFR
BAND OF STRATUS WITHIN SURFACE RIDGE AXIS FROM THE LOWER JAMES RIVER
VALLEY INTO NORTHEAST NEBRASKA. DIFFICULT TO DISCERN THIS BAND FROM
PRIMARILY VFR STRATUS FARTHER TO THE EAST...HOWEVER NAM/RAP MODELS
DO SHOW THIS VERY LOW LEVEL MOISTURE BAND MOVING TOWARD THE KSUX TAF
SITE BY MID-LATE MORNING. CONFIDENCE IS LOW THAT THE BAND WILL HOLD
TOGETHER/REACH KSUX...SO JUST WENT WITH MENTION OF SCATTERED CLOUD
LAYER BELOW 1KFT FOR NOW...BUT WILL WATCH CLOSELY THROUGH THE EARLY
PART OF THE PERIOD TO SEE IF BAND HOLDS TOGETHER. SOME MVFR STRATUS
CEILINGS SLIDING THROUGH NORTHEAST PARTS OF THE FORECAST AREA AS
WELL THIS MORNING...BUT NOT EXPECTED TO AFFECT TAF SITES AT THIS
TIME. BY 18Z...VFR CONDITIONS EXPECTED TO DOMINATE ACROSS THE AREA
WITH LIGHT/VARIABLE WINDS. NAM/RAP MODELS HINTING AT IFR-LIFR
STRATUS AND/OR FOG REDEVELOPING OVERNIGHT...POTENTIALLY AFFECTING
KFSD/KSUX AFTER 04Z IN ADVANCE OF SURFACE WARM FRONT. AGAIN HAVE
LOW CONFIDENCE IN THIS DEVELOPMENT AS MOISTURE LAYER APPEARS TO BE
SHALLOW ON FORECAST SOUNDINGS...SO HAVE LEFT TAFS VFR THROUGH THE
NIGHT FOR NOW.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1117 PM CST WED JAN 16 2013
.UPDATE...FOR 06Z AVIATION FORECAST
&&
.AVIATION...
WINTER STORM WATCH IN EFFECT FOR THE PLATEAU ON THURSDAY AS
FREEZING RAIN...SLEET AND SNOW WILL LIKELY IMPACT THE AREA.
THEREFORE POOR FLYING CONDITIONS WILL EXITS ALONG THE PLATEAU
BEGINNING AROUND 08Z AS CEILINGS AND VSBYS LOWER AND A MIX OF
LIGHT RAIN AND SLEET BEGINS. WINTER WEATHER WILL CONTINUE ALONG
THE PLATEAU DURING THE OVERNIGHT HOUR AND DURING THE DAY ON
THURSDAY.
AS FOR NASHVILLE NOT EXPECTING SIGNIFICANT PRECIP BUT WE COULD
SEE A MIX OF LIGHT RAIN AND SNOW FROM ABOUT MID MORNING THROUGH
NOON AND THEN A FEW FLURRIES IN THE AFTERNOON. MVFR CONDITIONS DUE
TO CEILINGS AND VSBYS WILL PREVAIL THROUGH A GOOD PART OF THE NEXT
24 HOURS.
CLARKSVILLE WILL LIKELY REMAIN VFR THROUGH A GOOD PART OF THE NEXT
24 HOURS WITH MVFR CONDITIONS POSSIBLE DUE TO CEILINGS FROM 15Z TO
ABOUT 18Z ON THURSDAY. FLURRIES ARE POSSIBLE IN THE AFTERNOON ON
THURSDAY.
GUSTY WINDS CAN BE EXPECTED ACROSS THE MID STATE FROM ABOUT MID-
DAY ON THROUGH THE AFTERNOON WITH SOME GUSTS OVER 20 KNOTS.
UPPER LOW OVER TEXARKANA WILL MOVE EASTWARD IN THE OVERNIGHT. 850
MILLIBAR LOW ABOUT JACKSON MISSISSIPPI. GOOD UPPER DIFFLUENCE
ACROSS THE TENNESSEE VALLEY WILL INCREASE IN THE OVERNIGHT AND ON
THURSDAY. LATEST RUC RUN HAS PRECIP BREAKING OUT SOUTHERN AND
EASTERN AREAS OF THE MID STATE AND ALONG THE PLATEAU. THIS IN LINE
WITH LATEST NSSL WRF RUN.
BOYD
&&
.PREV DISCUSSION... /ISSUED 946 PM CST WED JAN 16 2013/
UPDATE...
LATEST RADAR IMAGERY SHOWS RAIN HAS DIMINISHED IN COVERAGE AND
INTENSITY THIS EVENING WITH ONE MAIN BAND NOW EXTENDING FROM
NORTHWEST ALABAMA TO THE NORTHERN PLATEAU. HOWEVER...WATER VAPOR
IMAGERY DEPICTS A STRONG UPPER LEVEL LOW OVER EASTERN TEXAS THAT
WILL BE MOVING EASTWARD ACROSS THE GULF COAST STATES TO OUR SOUTH
TOMORROW. RAIN HAS ALREADY BEGUN DEVELOPING AND EXPANDING IN
COVERAGE ACROSS LOUISIANA AND MISSISSIPPI IN ASSOCIATION WITH THIS
SYSTEM...AND ADDITIONAL RAINFALL IS EXPECTED TO FORM LATE TONIGHT
AND SPREAD NORTHEASTWARD INTO OUR EASTERN ZONES. THERMAL PROFILES
WILL REMAIN TOO WARM FOR ANYTHING BUT RAIN TONIGHT EXCEPT
POSSIBLY ON THE FAR NORTHWEST EDGE OF THE PRECIPITATION WHERE A
VERY LIGHT RAIN/SNOW MIX HAS BEEN LEFT IN. HAVE UPDATED TEMPS AND
POPS FOR TONIGHT BASED ON THESE LATEST TRENDS.
AS UPPER LEVEL LOW MOVES TO OUR SOUTH DURING THE DAY ON
THURSDAY...A SURFACE LOW IS EXPECTED TO TAKE SHAPE AND DEEPEN OVER
THE CAROLINAS. CAA WILL CORRESPONDINGLY INCREASE ACROSS THE MID
STATE DURING THE DAY WITH GUSTY NORTH WINDS EXPECTED. AN
EXTENSIVE LOOK AT BUFKIT SOUNDINGS INDICATES THERMAL PROFILES WILL
BECOME FAVORABLE FOR A MIX OF RAIN AND SNOW...AND POSSIBLY
FREEZING RAIN AS WELL...OVER OUR PLATEAU COUNTIES THURSDAY MORNING
AS COLD AIR CONTINUES TO ADVECT SOUTHWARD...WITH A CHANGEOVER TO
ALL SNOW BY AFTERNOON AS SATURATED PROFILES FALL COMPLETELY BELOW
FREEZING. ALL PRECIP THEN EXITS THE AREA QUICKLY BY THURSDAY
EVENING AS SYSTEM SHIFTS OFF TO THE EAST.
SOME UNCERTAINTY REMAINS ON SNOW ACCUMS IN THE WSW AREA WITH BULK
OF PRECIP REMAINING TO OUR EAST AND CONCERNS WITH TIMING OF
CHANGEOVER AND SNOWFALL RATES. CURRENT REASONING IS CLOSEST TO A
BLEND OF HPC GUIDANCE WITH NAM/GFS SNOW ACCUMS...AND SHOWING A
GENERAL 1 TO 3 INCHES OF TOTAL SNOWFALL POSSIBLE ON THE
PLATEAU...WITH 4 INCH AMOUNTS NOT OUT OF THE QUESTION IN THE
TYPICALLY FAVORED AREAS OF HIGHER TERRAIN IN EASTERN
PUTNAM/CUMBERLAND/FENTRESS COUNTIES. SUCH AMOUNTS WOULD GENERALLY
BE A WINTER WEATHER ADVISORY TYPE EVENT...BUT WILL LET MID SHIFT
TAKE A LOOK AT 00Z GUIDANCE BEFORE DECIDING WHETHER AN ADVISORY OR
WARNING IS WARRANTED. ALSO APPEARS THERE WILL BE A SHARP CUTOFF TO
PRECIPITATION ON NORTHWEST EDGE OF PRECIP SHIELD PER 00Z NAM
AND MUCH OF MIDDLE TENNESSEE WEST OF THE CURRENT WSW AREA MAY BE
TOTALLY DRY TOMORROW...BUT WILL LEAVE LOW POPS IN FOR NOW.
UPDATED PRODUCTS WILL BE OUT SHORTLY.
PREV DISCUSSION... /ISSUED 649 PM CST WED JAN 16 2013/
UPDATE...FOR CSV AMENDMENT AT 170043Z
AVIATION...
TAKING A CLOSER LOOK AT THE FORECAST SOUNDING FOR CROSSVILLE HAVE
AMENDED TO INCLUDE A PERIOD OF FREEZING RAIN AND SLEET FROM 17/14Z
THROUGH ABOUT 17/18Z WITH SNOW BEGINNING BY 17/20Z. ICE ACCUMULATIONS ARE
LIKELY ALONG THE PLATEAU ON THURSDAY WITH SNOW ACCUMULATIONS OF 2
TO 4 INCHES POSSIBLE THURSDAY AFTERNOON.
BOYD
PREV DISCUSSION... /ISSUED 603 PM CST WED JAN 16 2013/
UPDATE...FOR 00Z AVIATION FORECAST
AVIATION...
CLOSED OFF UPPER LOW OVER NORTHEAST TEXAS THIS EVENING WILL SWING EAST
TONIGHT AND INTO MISSISSIPPI BY DAYBREAK THURSDAY. UPPER LOW WILL
MOVE EAST ACROSS ALABAMA AND INTO NORTHEAST GEORGIA BY EARLY THURSDAY
EVENING. MID STATE WILL BE ON THE COLD SIDE OF THIS SYSTEM WITH
GOOD COLD ADVECTION SPILLING IN DURING THE LATE MORNING AND MID
DAY ON THURSDAY. MORE RAIN TONIGHT AND THURSDAY MORNING ACROSS
SOUTHERN AND EASTERN AREAS WILL CHANGE TO SNOW OVER EASTERN AREAS
AND ALONG THE PLATEAU AROUND MID DAY THURSDAY WITH ACCUMULATIONS
LIKELY. THE SNOW COULD BECOME HEAVY AT TIMES AT CROSSVILLE WITH
VERTICAL VISIBILITIES OF < 100 FEET AND HORIZONTAL VISIBILITIES
DOWN TO 1/4 SM WITH SNOW ACCUMULATIONS LIKELY. SNOW WILL CONTINUE
INTO THE EVENING ALONG THE PLATEAU.
BOYD
PREV DISCUSSION... /ISSUED 354 PM CST WED JAN 16 2013/
DISCUSSION...LIGHT RAIN CONTINUES TO TRICKLE ACROSS MAINLY
SOUTHERN AND EASTERN MIDDLE TENNESSEE, WITH THE COLDEST PARTS OF
THE MID STATE STILL ECHO-FREE. LOOK FOR PRECIPITATION TO GRADUALLY
INCREASE OVERNIGHT AND TOMORROW AS AN UPPER LOW, CURRENTLY LOCATED
OVER THE ARK-LA-TEX, MOVES EASTWARD OVER THE NEXT 24 HOURS AND
SPREADS ADDITIONAL MOISTURE OVER MIDDLE TENNESSEE. WITH THE MID
STATE REMAINING ON THE COLD SIDE OF THE LOW, TEMPERATURES AREN`T
GOING TO WARM A GREAT DEAL. AREAS TO BE AFFECTED BY THIS SYSTEM
ARE PRIMARILY THE AREAS BEING AFFECTED NOW, THAT BEING SOUTHERN
MIDDLE TENNESSEE AND AREAS ALONG AND JUST WEST OF THE CUMBERLAND
PLATEAU. PRECIPITATION WILL REMAIN LIQUID DURING THE EVENING, BUT
LIGHT SNOW MAY MIX IN OVERNIGHT ACROSS THE COLDER PARTS, INCLUDING
THE NASHVILLE METRO AREA. LIGHT ACCUMULATIONS MAY OCCUR AS
TEMPERATURES BRIEFLY DROP TO FREEZING, BUT POP`S IN THESE AREAS
ARE LOW AND QPF`S REMAIN LOW, SO VERY LITTLE FROZEN PRECIPITATION
WILL OCCUR. LOOK FOR THE RAIN/SNOW MIX TO SPREAD EASTWARD DURING
THE MORNING AS ABOVE-SURFACE TEMPERATURES ALONG THE PLATEAU COOL.
(THICKNESS VALUES BY THURSDAY AFTERNOON DO SUPPORT SNOW.) SURFACE
TEMPERATURES WILL REMAIN ABOVE FREEZING THROUGHOUT MOST OF THE
DAY, WITH TEMPERATURES GETTING INTO THE LOWER 40`S TOMORROW
AFTERNOON ACROSS MAINLY THE WESTERN HALF OF MIDDLE TENNESSEE.
PLATEAU LOCATIONS WILL LIKELY SEE LIGHT ACCUMULATION OF SNOW
THURSDAY AFTERNOON AND EARLY EVENING, WITH AMOUNTS GENERALLY UNDER
ONE-HALF INCH. THIS WILL KEEP US BELOW ADVISORY CRITERIA, SO WILL
COVER THIS WITH A SPECIAL WEATHER STATEMENT SHORTLY.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM 6 AM CST THURSDAY THROUGH THURSDAY
AFTERNOON FOR TNZ011-032>034-065-066-077>080.
&&
$$
01
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
243 AM MST SAT JAN 19 2013
.SHORT TERM...DRY NW FLOW ALOFT WILL CONTINUE TODAY AND TONIGHT. A
MTN WAVE EARLY THIS MORNING IS ALLOWING FOR SOME GUSTY NWLY WINDS
IN AND NR THE FOOTHILLS WHICH WILL LINGER THRU THE MID MORNING
HOURS BEFORE DECREASING SOME BY MIDDAY. OTHERWISE GUSTY NW WINDS
WILL ALSO OCCUR ALONG AND NR THE WY-NE BORDER ESPECIALLY LATER
THIS MORNING INTO THE AFTN HOURS AS BETTER MIXING DEVELOPS. AS FOR
HIGHS READINGS WILL BE IN THE 50S ACROSS NERN CO. ONCE AGAIN IN
THE HIGHER MTN VALLEYS INVERSIONS WILL LEAD TO WIDE TEMP SPREADS
ESPECIALLY ACROSS ZONE 32.
FOR TONIGHT ANOTHER MTN WAVE MAY DEVELOP AFTER MIDNIGHT LEADING TO
AN INCREASE IN WINDS OVER THE HIGHER MTNS AND FOOTHILLS. AT THIS
TIME IT APPEARS SPEEDS SHOULD STAY BLO HIGHLIGHT CRITERIA.
.LONG TERM...NORTHWESTERLY FLOW ALOFT IS PROGGED TO CONTINUE OVER
THE FORECAST AREA SUNDAY AND SUNDAY NIGHT. ON MONDAY...THE FLOW
IS PROGGED TO BECOME NORTH-NORTHWESTERLY AND INCREASE A BIT IN
SPEED. BY TUESDAY MORNING AT 12Z IT WEAKENS AND IS BACK TO A
NORTHWESTERLY DIRECTION. AT THAT TIME AN UPPER RIDGE AXIS IS
LOCATED OVER THE GREAT BASIN. THE SYNOPTIC SCALE ENERGY IS PROGGED
TO BE BENIGN SUNDAY THROUGH MONDAY NIGHT. THE BOUNDARY LAYER FLOW
LOOKS TO BE UPSLOPING FOR THE PLAINS AND FOOTHILLS SUNDAY...WITH
NORMAL DUIRNAL PATTERNS FOR SUNDAY NIGHT INTO MONDAY. LOW LEVEL
TROUHGING EAST OF THE MOUNTAINS SETS UP LATER SUNDAY THROUGH
TUESDAY NIGHT...BUT THE GRADIENT IS PRETTY WEAK. A MIX OF NORMAL
TRENDS TO DOWNSLOPING SHOULD PREVAIL THOSE TWO PERIODS. MOISTURE
CONTINUES TO BE QUITE LIMITED ACCORDING TO THE MODELS. THERE IS A
LITTLE OVER THE PLAINS WITH THE UPSLOPE SUNDAY AFTERNOON AND
EVENING...MORE SO ON THE GFS. THE GFS ALSO SHOWS A TAD IN THE
UPPER LEVELS MONDAY AND MONDAY NIGHT...BUT THAT`S ABOUT IT. THERE
IS NO MEASURABLE PRECIPITATION NOTED ON THE QPF FIELDS FOR THE
FORECAST AREA SUNDAY THROUGH MONDAY NIGHT. NO POPS. FOR
TEMPERATURES...SUNDAY`S HIGHS ARE 4-8 C COLDER THAN TODAY`S
EXPECTED HIGHS. MONDAY`S READINGS WARM UP 3-5 C OVER SUNDAY`S. FOR
THE LATER DAYS...TUESDAY THROUGH FRIDAY...MODELS HAVE PRETTY WEAK
NORTHWESTERLY FLOW ALOFT FOR THE CWA TUESDAY AND WEDNESDAY.
BY THURSDAY...THE ECMWF AND GFS START DEVELOPING AN UPPER TROUGH
NORTH AND NORTHEAST OF COLORADO. THE FLOW ALOFT INCREASES AND IS
ZONAL ON THURSDAY. BY FRIDAY...A MEAN TROUGH IS PROGGED TO COVER
THE EASTERN HALF OF NORTH AMERICA...AND AN UPPER RIDGE IS OVER
THE GREAT BASIN. THE GFS BRINGS SOME MOISTURE OVER THE CWA
THURSDAY AND THURSDAY NIGHT. THE ECMWF DOES NOT. THE OTHER DAYS
ARE PRETTY DRY ON BOTH MODELS. WILL KEEP POPS OUT FOR NOW.
TEMPERATURES REMAIN ABOVE SEASONAL NORMALS THROUGH THE PERIOD.
&&
.AVIATION...WEST WINDS HAVE SPREAD ACROSS THE AIRPORT EARLY THIS
MORNING BUT SHOULD BECOME MORE SWLY AFTER SUNRISE. BY 16Z WINDS
MAY BECOME MORE SLY. FOR THIS AFTN THERE IS QUITE A DIFFERENCE IN
WIND FCSTS AS THE HRRR AND RAP INDICATE A LONGMONT ANTI-CYCLONE
DEVELOPING WITH WINDS BECOMING MORE ELY BY EARLY AFTN WHILE THE
NAM HAS A WLY COMPONENT. WITH NWLY FLOW OVER THE CHEYENNE RIDGE
THAT WOULD FAVOR A POTENTIAL ANTI-CYCLONE SO WILL TREND TAF
TOWARDS THE HRRR/RAP SOLUTION. BY EARLY EVENING WINDS SHOULD
GRADUALLY TRENDS TOWARDS DRAINAGE. VFR CONDITIONS WILL BE IN PLACE
TODAY THRU TONIGHT.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RPK
LONG TERM....RJK
AVIATION...RPK
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
352 AM EST SAT JAN 19 2013
.DISCUSSION...
CURRENTLY...STRONG HI PRES RIDGE EXTENDING FROM THE CAROLINAS TO
THE NW GOMEX. THE USAF CAPE PROFILER AND THE KTBW VAD WIND
PROFILE SHOWING 25-30KTS OF ERLY FLOW 5KFT...DIMINISHING TO
15-25KTS AT THE KJAX VAD WIND PROFILE. RAP ANALYSIS SHOWS HIGH
REGIONAL MOISTURE THRU THE H100-H85 LYR ASSOCD WITH A MARINE
STRATOCU DECK. KMFL/KTBW EVENING SOUNDINGS HAVE A SATURATED
H100-H80 LYR TRAPPED BLO A STOUT SUBSIDENCE INVERSION...THOUGH
PWAT VALUES TOP OUT ARND 0.80". KJAX SOUNDING IS A BIT DRIER WITH
PWAT ARND 0.40". RADAR SHOWS PERIODIC BANDS OF LIGHT RAIN MVG
ONSHORE S OF CAPE CANAVERAL.
TODAY-TONIGHT...THE HI PRES RIDGE WILL MAINTAIN A DEEP/STEADY
NERLY SFC/LOW LVL FLOW AS IT GRADUALLY WEAKENS. LOW LVL MOISTURE
IS HIGH ENOUGH TO MAINTAIN ISOLD/SCT SHRAS...THOUGH ITS SHALLOW
DEPTH WILL LIMIT QPF TO 0.10" OR LESS. DEPTH/STRENGTH OF THE NE
FLOW WILL PUSH THESE SHRAS WELL INTO THE INTERIOR THRU THE AFTN.
PRECIP WILL END OVER THE INTERIOR OVERNIGHT AS WINDS DIMINISH BUT
WILL CONTINUE ALONG THE COAST.
THE DEEP ONSHORE FLOW WILL TAP MOIST/MILD OCEAN AIR TO KEEP TEMPS
ABV AVG. MAXES IN THE M/U70S...MINS IN THE M/U50S ALONG AND N OF
THE I-4 CORRIDOR AND L/M60S ALONG THE SPACE/TREASURE COASTS.
SUN...A WEAK INVERTED TROUGH IS FORECAST TO DEVELOP EAST OF
FLORIDA WHICH WILL BACK THE LOW LEVEL FLOW SOME...TO THE N/NE. IT
WILL ALSO PRODUCE A BAND OF MOISTURE CONVERGENCE EXTENDING FROM
THE ATLC SW ACROSS THE COAST TOWARDS OKEECHOBEE...WHICH SHOULD
PRODUCE BRING SOME SHOWERS ACROSS THE COAST MAINLY SOUTH OF THE
CAPE. SO WILL MAINTAIN A SMALL 20 POP THERE AS WELL AS SOUTHERN
INTERIOR SECTIONS THOUGH SOME AREAS COULD SEE A FEW PERIODS OF
RAIN WITH LOCALLY HIGHER RAIN CHANCES AND AMOUNTS. FORECAST MODEL
SOUNDINGS SHOW CONSIDERABLE STRATOCUMULUS CLOUDS ALONG WITH SOME
CIRRUS SO MORE CLOUDS THAN SUN EXPECTED. NONETHELESS...
TEMPERATURES WILL REMAIN SLIGHTLY ABOVE NORMAL WITH HIGHS IN THE
MID 70S. LESS ONSHORE FLOW SUNDAY NIGHT SHOULD ALLOW COASTAL
COMMUNITIES SOUTH OF THE CAPE TO COOL A FEW MORE DEGREES WITH LOWS
NEAR 60.
MON-FRI...THE WEEK BEGINS WITH A HIGHLY AMPLIFIED UPPER PATTERN
ACROSS THE U.S...RIDGE IN THE WEST AND TROUGH IN THE EAST.
MEANWHILE...AT THE SURFACE A REINFORCING HI PRES RIDGE WILL DROP
OUT OF CANADA AND BUILD INTO THE SE U.S. MONDAY AND TUESDAY AND
BRING COOLER AND ESPECIALLY DRIER CONDITIONS INTO MIDWEEK. PRIOR
TO INFLUX OF MUCH DRIER AIR...THERE STILL LOOKS TO BE ENOUGH
MOISTURE TO PRODUCE A FEW SHOWERS MONDAY ALG THE TREASURE COAST TO
OKEECHOBEE SO HAVE MAINTAINED SMALL 20 POP THERE. RAIN CHANCES
LOOK QUITE SLIM TUE-THU AND HAVE KEPT THE FORECAST DRY.
AFTER A MILD MONDAY...BOTH HIGH AND LOW TEMPERATURES ARE FORECAST
TO FALL AT OR SLIGHTLY BELOW NORMAL TUE-WED WITH UPPER 30S
POSSIBLE ACROSS NORTH LAKE COUNTY WED MORNING. FREEZING
TEMPERATURES ARE STILL NOT EXPECTED AT THIS TIME. HIGH TEMPS ARE
FORECAST TO RANGE FROM THE MID 60S NORTH OF ORLANDO TO THE LOWER
70S OKEECHOBEE/ TREASURE COAST. SOME MODERATION OF TEMP/MOISTURE
WILL OCCUR BY THU AS HIGH PRESSURE PUSHES EAST INTO THE ATLC AND A
MORE DIRECT ONSHORE FLOW DEVELOPS.
&&
.AVIATION...
THRU 20/00Z...PREVAILING CIGS BTWN FL040-060. ISOLD MVFR SHRAS E OF
KTIX-KISM-KOBE THRU 19/14Z. AFT 19/14Z...ISOLD MVFR SHRAS ALL SITES
WITH SFC WND G18-22KTS.
&&
.MARINE...
TODAY-TONIGHT...RIDGE AXIS OVER THE DEEP SOUTH WILL MAINTAIN A
MODERATE TO FRESH NERLY BREEZE THRU MID AFTN. THE RIDGE WILL
GRADUALLY WEAKEN THRU DAYBREAK SUN...ALLOWING WIND TO DIMINISH BLO
THE 20KT SCA THRESHOLD BY LATE AFTN. HOWEVER...THE NE COMPONENT WILL
CONTINUE TO PUSH SWELL ENERGY INTO THE E FL COAST...KEEPING SEAS ABV
SCA CRITERIA THRU EARLY SUN MORNING. WIND SCA EXPIRATION TIME OF 21Z
LOOKS REASONABLE...WILL EXTEND THE SCA FOR SEAS THRU 09Z SUN.
SUN-WED...INVERTED TROUGH DEVELOPING EAST OF THE WATERS WILL BACK
WINDS TO A MORE N/NE DIRECTION SUNDAY WITH SPEEDS AROUND 10-15 KTS
AND SEAS 4-6 FT. SO WILL LIKELY NEED A CAUTION HEADLINE AT LEAST
FOR THE GULF STREAM SUNDAY. WATERS WILL BE IN A LIGHT NORTHERLY
PRES GRAD MONDAY BUT NORTH WINDS WILL INCREASE MONDAY NIGHT/EARLY
TUE AS HIGH PRESSURE BUILDS OVER THE AREA FROM THE NORTHWEST.
THERE WILL LIKELY BE A BRIEF PERIOD OF HAZARDOUS BOATING CONDITIONS
WITH ADVISORIES ISSUED TUE/TUE NIGHT. SWAN MODEL BUILDS SEAS TO 6
FT OFFSHORE WOULD NOT BE SURPRISED TO SEE 7 FT IN THE GULF STREAM.
THEN WINDS DECREASE PRETTY QUICKLY WED AS HIGH PRESSURE CENTER
SETTLES OVER THE AREA WITH SEAS SUBSIDING.
&&
.FIRE WEATHER...
NO LOW RH CONCERNS THROUGH MONDAY THOUGH MIN RH VALUES WILL BE A
LITTLE LOWER...40 TO 45 PERCENT ORLANDO NORTHWARD...MONDAY AFTN.
COOLER AND MUCH DRIER AIR IS FORECAST TO OVERSPREAD THE AREA TUE
AND PRODUCE MIN RH VALUES BELOW 35 PERCENT WITH N/NW WINDS AROUND
15 MPH. WED COULD BE NEARLY AS DRY ACROSS THE INTERIOR BUT WINDS
LOOK LIGHTER.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 74 60 73 55 / 20 10 10 10
MCO 76 59 76 57 / 20 10 10 10
MLB 75 65 77 61 / 30 20 20 20
VRB 75 65 78 60 / 30 20 20 20
LEE 75 57 75 55 / 20 10 10 10
SFB 75 59 75 57 / 20 10 10 10
ORL 75 59 75 58 / 20 10 10 10
FPR 76 65 77 61 / 30 20 20 20
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR COASTAL
WATERS FROM FLAGLER BEACH TO VOLUSIA BREVARD COUNTY LINE
OUT 20 NM-COASTAL WATERS FROM SEBASTIAN INLET TO JUPITER
INLET OUT 20 NM-COASTAL WATERS FROM VOLUSIA BREVARD COUNTY
LINE TO SEBASTIAN INLET OUT 20 NM-WATERS FROM FLAGLER BEACH
TO VOLUSIA BREVARD COUNTY LINE 20 TO 60 NM OFFSHORE-WATERS
FROM SEBASTIAN INLET TO JUPITER INLET 20 TO 60 NM OFFSHORE-
WATERS FROM VOLUSIA BREVARD COUNTY LINE TO SEBASTIAN INLET
20 TO 60 NM OFFSHORE.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 4 PM THIS AFTERNOON
TO 4 AM EST SUNDAY FOR COASTAL WATERS FROM FLAGLER BEACH TO
VOLUSIA BREVARD COUNTY LINE OUT 20 NM-COASTAL WATERS FROM
SEBASTIAN INLET TO JUPITER INLET OUT 20 NM-COASTAL WATERS
FROM VOLUSIA BREVARD COUNTY LINE TO SEBASTIAN INLET OUT 20
NM-WATERS FROM FLAGLER BEACH TO VOLUSIA BREVARD COUNTY LINE
20 TO 60 NM OFFSHORE-WATERS FROM SEBASTIAN INLET TO JUPITER
INLET 20 TO 60 NM OFFSHORE-WATERS FROM VOLUSIA BREVARD
COUNTY LINE TO SEBASTIAN INLET 20 TO 60 NM OFFSHORE.
&&
$$
SHORT TERM...BRAGAW
LONG TERM....KELLY
AREA FORECAST DISCUSSION
NWS MIAMI FL
809 AM EST SAT JAN 19 2013
.UPDATE...UPDATED MOST ELEMENTS FOR CURRENT TRENDS. AREA OF LIGHT
RAIN NOW IS FOCUSED ACROSS METRO BROWARD. HRRR AND NAM SHOW A
GRADUALLY NORTHWARD SHIFT ALONG THE ATLANTIC COAST WITH TIME
TODAY. NAM KEEPS A SOLID AREA OF QPF MOVING UP THE PALM BEACH
COAST WHILE THE HRRR LESSENS QPF THIS AFTERNOON, SO TOOK A MIDDLE
OF THE ROAD APPROACH. LOOKS LIKE TWO WEAK LOWS HAVE
DEVELOPED...ONE OVER OUR ATLANTIC WATERS AND ANOTHER CLEARLY
DEFINED ONE ON SAT IMAGERY OVER THE GULF OFF THE SW FL COAST.
THESE FEATURES WILL KEEP EXTENSIVE CLOUDINESS OVER THE AREA TODAY,
BUT WITH A FEW BREAKS EXPECTED IN THE AFTERNOON. THIS SHOULD
MANAGE TO ALLOW TEMPS TO REACH FORECASTED HIGHS, BUT WILL NEED TO
MONITOR THIS BC IF THERE ARE NO BREAKS, HIGHS MAY BE A TAD TOO
WARM. IT DOESN`T TAKE MUCH BREAKS TO ACHIEVE OUR WARMER HIGHS
ADVERTISED SO HAVE KEPT THE FCST AS IS FOR NOW FOR MAX T.
/GREGORIA
&&
.PREV DISCUSSION... /ISSUED 645 AM EST SAT JAN 19 2013/
AVIATION...
MOSTLY CLOUDY SKIES WILL PREVAIL ACROSS SOUTH FLORIDA THIS
MORNING. LIGHT DRAINAGE FLOW IS STILL PRESENT ACROSS THE EASTERN
TERMINALS...BUT WILL SHIFT TO THE EAST BY 19/18Z. VCSH WAS KEPT
AS PREVAILING AT ALL EASTERN TERMINALS EXCEPT FOR KPBI. SHOWERS
WILL CONTINUE DEVELOPING THIS AFTERNOON...FOR THIS REASON KEPT
VCSH AT ALL EASTERN TERMINALS THROUGH THE EVENING. FOR KAPF...DRY
CONDITIONS EXPECTED THROUGH THE PERIOD. WIND FLOW WILL BE WEAK
ENOUGH TO ALLOW FOR THE SEABREEZE TO DEVELOP BY 19/19Z.
PREV DISCUSSION... /ISSUED 338 AM EST SAT JAN 19 2013/
DISCUSSION...
AN ACTIVE NIGHT ALONG THE ATLANTIC COAST HAS BEEN THE CASE
THIS MORNING. SHOWERS HAVE BEEN DEVELOPING ALL NIGHT ALONG A STALLED
FRONTAL BOUNDARY, LAYING JUST TO THE SOUTHEAST OF THE CWA. MODELS
ARE SHOWING A WEAK LOW FORMING ALONG THIS BOUNDARY, WHICH WILL ACT
AS THE FOCAL POINT FOR CONTINUED DEVELOPMENT OF SHOWERS TODAY,
MAINLY SCATTERED IN NATURE. THIS ACTIVITY WILL CONTINUE INTO THE
EVENING HOURS AND BEGIN TO DIE DOWN TONIGHT. THE LOW THEN LOOKS TO
FALL APART LATER ON SUNDAY. THERE LOOKS TO BE SOME UPPER LEVEL
SUPPORT FOR THE SHOWERS TO BE NORTH, AS A JET STREAK WILL MOVE IN
AND THE LEFT EXIT REGION WILL BE AROUND THE JAX AREA. KEPT A
MENTION OF MAINLY A SLIGHT CHANCE OF COASTAL SHOWERS FOR THE NEXT
FEW DAYS.
FOR THE BEGINNING OF THE WEEK, A COLD FRONT, WITH AN ARCTIC PUSH,
MOVES THROUGH THE CWA. THERE IS LITTLE EXPECTED IN THE WAY OF
PRECIPITATION, BUT IT SHOULD ALLOW TEMPERATURES COOL SOMEWHAT. IT
WILL KEEP THE HIGH TEMPERATURES IN THE 70S THIS WEEK, WHICH IS NOT
MUCH DIFFERENT THAN THE WEEKEND. HOWEVER, THE LOW TEMPERATURES
WILL BE ABLE TO DROP INTO THE MID TO UPPER 40S IN THE NORTHWEST
ZONES OF THE CWA. THE MAIN COLD AIR MASS DOES LOOK TO REMAIN WELL
TO THE NORTH, SO TEMPERATURES ALONG THE COAST AND FAR SOUTH
FLORIDA ARE EXPECTED TO ONLY DROP INTO THE LOW 60S, MAYBE UPPER
50S.
BEYOND THE COLD FRONT, HIGH PRESSURE WILL SET UP ONCE AGAIN, WHICH
WILL KEEP THE WEATHER QUIET FROM TUESDAY NIGHT THROUGH THE END OF
THE WEEK, WITH HIGH TEMPERATURES SLOWLY RISING THROUGH THE WEEK.
FIRE WEATHER...
A STALLED FRONTAL BOUNDARY AND A DEVELOPING LOW PRESSURE SYSTEM
NEAR THE AREA, WILL KEEP SHOWERS DEVELOPING ALONG THE ATLANTIC
COAST AND KEEP ENOUGH SURFACE MOISTURE IN PLACE TO KEEP RH VALUES
ABOVE ANY CRITICAL LEVELS. WINDS LOOK AS THOUGH THEY WILL BE
LIGHTER THE ORIGINALLY THOUGH FOR THE NEXT COUPLE OF DAYS, WHICH
WILL MEAN THEY WILL ALSO NOT REACH ANY CRITICAL LEVELS FOR THE
NEXT SEVERAL DAYS. THERE WILL BE A COLD FRONT NEXT WEEK, WHICH MAY
BRING SOME GUTSY WINDS AND A SLIGHT CHANCE FOR A SHOWER. BEHIND
THIS FRONT, A MUCH DRIER AIR MASS IS EXPECTED. MIN RHS MAY DROP
DOWN INTO THE MID 30 PERCENT RANGE IN THE NORTHWESTERN FIRE
WEATHER ZONES. HOWEVER, WINDS ARE CURRENTLY EXPECTED TO REMAIN
BELOW THRESHOLDS AT THIS TIME.
MARINE...
FOR THE GULF WATERS...SEAS ARE EXPECTED TO STEADILY SUBSIDE THE
REMAINDER OF TODAY AS THE WINDS ACROSS THE REGION ARE FORECAST TO
BECOME MORE NORTHEASTERLY AND SLOWLY SUBSIDE.
FOR THE ATLANTIC WATERS...AS MODERATE NORTH TO NORTHEAST WINDS
CONTINUE TO BUILD INTO THE REGION TODAY...THE ATLANTIC AND GULF
STREAM SEAS ARE EXPECTED TO INCREASE THE REMAINDER OF TODAY THEN
FORECAST TO BUILD QUICKLY TO ADVISORY LEVELS BY EARLY SATURDAY
MORNING...MAINLY TO THE EAST OF PALM BEACH COUNTY...AND TO
PERSIST THROUGH SATURDAY EVENING. A SMALL CRAFT ADVISORY IS IN
EFFECT FOR THE ATLANTIC WATERS AT 00Z SUNDAY THIS EVENING.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 77 66 78 65 / 50 30 20 20
FORT LAUDERDALE 78 67 79 67 / 80 30 20 20
MIAMI 79 66 80 66 / 50 30 20 20
NAPLES 75 63 77 63 / 20 10 10 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR COASTAL
WATERS FROM DEERFIELD BEACH TO OCEAN REEF, FL OUT 20 NM-
COASTAL WATERS FROM JUPITER INLET TO DEERFIELD BEACH, FL
OUT 20 NM-WATERS FROM DEERFIELD BEACH TO OCEAN REEF, FL
EXTENDING FROM 20 NM TO THE TERRITORIAL WATERS OF THE
BAHAMAS-WATERS FROM JUPITER INLET TO DEERFIELD BEACH, FL
EXTENDING FROM 20 NM TO 60 NM.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
947 AM CST SAT JAN 19 2013
.SHORT TERM...TODAY THROUGH MONDAY NIGHT
947 AM CST SAT JAN 19 2013
947 AM UPDATE...FORECAST IN GENERAL REMAINS ON TRACK. POTENT
SHORTWAVE WAS NOTED ON THE 15Z WATER VAPOR LOOP OVER SOUTHERN
MANITOBA...WITH A 120-140 KT JET AT THE TROPOPAUSE DIGGING INTO
THE DAKOTAS ON THE SOUTHWEST SIDE OF THE SHORTWAVE PER RAP
ANALYSIS. DPVA AHEAD OF THE SHORTWAVE HAS RESULTED IN A DEEPENING
SURFACE LOW...CURRENTLY AROUND 1002MB CENTERED OVER THE MN
ARROWHEAD. TRAILING THE LOW IS AN ARCTIC COLD FRONT ALONG THE
NORTH DAKOTA/SOUTH DAKOTA BORDER. SURFACE TEMPERATURES DROP FROM
THE MID TO UPPER 30S FROM SOUTH DAKOTA INTO THE FORECAST
AREA...INTO THE SINGLE DIGITS ABOVE ZERO OVER NORTHERN NORTH
DAKOTA. WITH THE RAPID DROP IN TEMPERATURES IS A 2 MB/HR PRESSURE
RISE OVER NORTH DAKOTA. THESE PRESSURE RISES AND A TIGHT PRESSURE
GRADIENT BEHIND THE ARCTIC FRONT HAS RESULTED IN WINDS GUSTING
30-50 KT ACROSS NORTH DAKOTA INTO FAR NORTHWEST MN. THERE ARE ALSO
SOME SNOW SHOWERS OCCURRING IMMEDIATELY BEHIND THE FRONT...AIDED
BY LOW LEVEL FRONTOGENESIS.
NAM/RAP/HRRR FORECASTS CONTINUE TO INDICATE THAT THE ARCTIC FRONT
WILL CROSS THE FORECAST AREA BETWEEN 21-00Z...WITH WINDS AND GUSTS
RAPIDLY INCREASING BEHIND THE FRONT AS INDICATED OVER NORTH
DAKOTA. INTERESTING TO SEE THAT AT 00Z...THE RAP WIND GUSTS SHOW
UPWARDS OF 40 KT OR SO ACROSS THE ENTIRE FORECAST AREA. NEEDLESS
TO SAY...THE WIND ADVISORY LOOKS SOLID. PLUS...THE SURFACE LOW
SHOULD BE ABLE TO DEEPEN A LITTLE MORE AS IT MOVES ACROSS THE
WARMER LAKE SUPERIOR WATER...AND HAS THE SYNOPTIC SCALE IMPACT TO
DEEPEN.
THERE ARE 2 ISSUES PRIOR TO THE ARCTIC FRONT ARRIVAL...THOUGH. THE
FIRST IS CLOUD COVER. FIRST BAND OF MID CLOUDS...ASSOCIATED WITH A
SHORTWAVE SEEN ON WATER VAPOR STRETCHING FROM NORTHEAST NEBRASKA
TO LA CROSSE...IS CLEARING OUT OF THE FORECAST AREA RIGHT NOW.
ANOTHER BATCH OF MID CLOUDS HAVE DEVELOPED OVER CENTRAL MN...AHEAD
OF ANOTHER WEAK SHORTWAVE. THESE CLOUDS APPEAR SLATED TO CROSS THE
FORECAST AREA DURING THE NEXT FEW HOURS. HAVE INCREASED CLOUD
COVER TO ACCOUNT FOR THESE. THERE STILL MAY BE ANOTHER BREAK IN
CLOUDS BEFORE THE ARCTIC FRONT ARRIVES. WITH THE IN-AND-OUT
PERIODS OF SUNSHINE AND 925MB TEMPS AROUND 5C PER 12Z MPX AND DVN
RAOBS...CONCERNED TEMPERATURES ARE NOT HIGH ENOUGH. HRRR ACTUALLY
HAS TEMPERATURES CLIMBING INTO THE LOW 50S OVER THE SOUTHERN HALF
OF THE FORECAST AREA. HRRR DID VERY WELL YESTERDAY...ALBEIT WE DID
HAVE FULL SUNSHINE. FOR NOW HAVE INCREASED TEMPERATURES
SLIGHTLY...MAINLY SOUTH OF I-90.
LASTLY...RAP AND 00Z/06Z NCEP HIRES ARW RUNS ARE IN GOOD AGREEMENT
SHOWING THE BAND OF SNOW SHOWERS OVER SOUTHERN NORTH DAKOTA POST-
FRONTAL DROPPING THROUGH MOST OF THE FORECAST AREA BETWEEN 18-00Z.
PREVIOUS FORECAST HAD THIS COVERED WELL...JUST GAVE A LITTLE MORE
TIMING AND SWITCHED TO A COVERAGE SNOW SHOWERS PHRASING SINCE
THERE IS A CONVECTIVE NATURE TO THE PRECIPITATION.
PREVIOUS DISCUSSION ISSUED AT 318 AM...
THE MAIN FOCUS IS ON THE DRASTIC CHANGES THAT ARE ON TAP FOR TODAY
AS A COLD FRONT DROPS THROUGH THE REGION.
CURRENTLY...BROAD CYCLONIC FLOW ALOFT IS IN PLACE THROUGH MUCH OF
CANADA AND THE US WITH THE CORE OF THE LOW CENTERED TO THE EAST OF
HUDSON BAY LEAVING THE UPPER MISSISSIPPI RIVER VALLEY IN
NORTHWESTERLY FLOW. DESPITE THIS...LOW LEVEL TEMPERATURES REMAIN
MILD AT THE MOMENT WITH A SURFACE LOW OVER EASTERN NORTH DAKOTA
AND A WARM FRONT EXTENDING TO THE EAST-SOUTHEAST ACROSS NORTHERN
WISCONSIN. THIS MORNING WILL END UP BEING THE WARMEST PART OF THE
DAY AS THIS SURFACE LOW TRACKS TO THE EAST TOWARD THE UP OF
MICHIGAN. THIS FEATURE WILL BRING A COLD FRONT THROUGH THE REGION
EARLY THIS AFTERNOON WITH WINDS SHIFTING TO THE NORTHWEST AND
BECOMING STRONG POST-FROPA. NOT A WHOLE LOT OF CHANGES TO THE
GOING WIND FORECAST WITH A TIGHTENING SURFACE PRESSURE
GRADIENT...STRONG LOW LEVEL COLD AIR ADVECTION AND 3HR PRESSURE
RISES OF 6-8MB SHOULD ALL LEAD TO STRONG AND GUSTY WINDS FOR A 6
TO 9 HOUR PERIOD LATE THIS AFTERNOON AND EVENING. SUBSIDENT AIR
SHOULD HELP TO MIX DOWN SOME HIGHER GUSTS IN THE 45-50MPH
RANGE...PARTICULARLY IN THE HIGHER ELEVATIONS IN SOUTHEAST
MINNESOTA AND NORTHEAST IOWA. BASED ON ALL THIS...THE WIND
ADVISORY STILL LOOKS GOOD FOR THE REGION STARTING MID AFTERNOON
AND ENDING AROUND MIDNIGHT AS THE WINDS DIMINISH.
ANOTHER FEATURE WITH THIS FRONT IS THE BRIEF SHOT OF SNOW THAT
WILL COME WITH IT. THE 19.00Z NAM AND MESO-MODELS SHOW A BAND OF
SNOW FORMING OUT AHEAD OF THE COLD FRONT WHERE THE OVERALL FORCING
IS A LITTLE STRONGER ACROSS SOUTHEAST MINNESOTA AND NORTH CENTRAL
WISCONSIN. THIS WILL LEAD TO A SHORT PERIOD...LIKELY LESS THAN AN
HOUR...OF SNOW WHICH COULD BRIEFLY BE HEAVY. THIS COULD LEAD TO A
BRIEF DUSTING OF AROUND A HALF INCH OF SNOW AS IT COMES THROUGH.
KEPT SOME FLURRIES THROUGH THE NIGHT ACROSS MUCH OF THE REGION DUE
TO THE LOW LEVEL SATURATED LAYER BEING IN THE ICE LAYER OF -8C TO
-20C...THOUGH THEY MAY NOT OCCUR IF THE SUBSIDENCE IS TOO STRONG
AND CLEARS THINGS OUT.
ALTHOUGH WINDS WILL BE ON THE DECREASE AFTER MIDNIGHT...THEY WILL
STILL BE IN THE 10-20MPH RANGE AS THE COLDER AIR MOVES INTO THE
REGION. BASED ON THE TEMPERATURE/WIND FORECAST...THERE COULD BE
SOME -20F TO -25F WIND CHILLS THAT OCCUR ACROSS PORTIONS OF
SOUTHEAST MINNESOTA AND NORTH CENTRAL WISCONSIN. THIS MAY WARRANT
THE NEED FOR A WIND CHILL ADVISORY ONCE THE WIND ADVISORY ENDS.
MAY STILL GO FOR ONE THIS MORNING...BUT AM STILL WORKING ON THE
COLLABORATION WITH NEIGHBORING OFFICES AT THE MOMENT ON WHETHER
TO GO FOR IT NOW OR LATER TODAY.
BEYOND THIS ITS ALL ABOUT HOW COLD TEMPERATURES WILL GET WITH
LITTLE TO NO SNOW PACK OUT THERE. A WEAKENING MID LEVEL TROUGH
THAT HAS LITTLE LOW LEVEL SUPPORT WILL MOVE THROUGH ON SUNDAY AND
COULD PROVIDE ANOTHER DUSTING OF SNOW...THOUGH CONFIDENCE IS NOT
VERY HIGH ON THIS WITH THE WEAK MID LEVEL LIFT. HAD THE SNOW PACK
NOT ERODED AWAY LAST WEEK...OUR TEMPERATURES WOULD LIKELY BE ABOUT
10 DEGREES COLDER THAN WHAT IS BEING FORECAST. DESPITE THIS...THE
GUIDANCE ALL REMAINS IN GOOD AGREEMENT OF HAVING SUB-ZERO
TEMPERATURES IN PLACE TO START NEXT WEEK. WIND CHILL ADVISORIES
WILL DEFINITELY BE NEEDED FROM MONDAY MORNING THROUGH TUESDAY
MORNING WITH WIND CHILLS IN THE -20F TO -30F RANGE.
.LONG TERM...TUESDAY THROUGH FRIDAY
318 AM CST SAT JAN 19 2013
THE COLD AIR MASS APPEARS TO REMAIN IN PLACE ACROSS THE UPPER
MISSISSIPPI RIVER VALLEY THROUGH THE REST OF THE WEEK THOUGH IT
DOES MODERATE SOME GOING INTO WEDNESDAY AND BEYOND AS THE RIDGE
AXIS MOVES THROUGH AND THE CORE OF COLD LOW LEVEL AIR SHIFTS TO
THE EAST. THERE ARE SOME HINTS THAT A SYSTEM WILL DROP DOWN
THROUGH THE NORTHWEST FLOW ALOFT TUESDAY INTO TUESDAY NIGHT WHICH
COULD BRING SOME SNOW ALONG WITH IT. THE 19.00Z GFS IS THE ONLY
MODEL SHOWING THIS SNOW REACHING THE FORECAST AREA WITH THE 19.00Z
ECMWF PLACING THE SURFACE RIDGE RIGHT ALONG THE MISSISSIPPI RIVER.
SHOULD THE GFS PAN OUT...THERE COULD BE SOME HIGH RATIO SNOW THAT
OCCURS WITH 19.00Z BUFKIT SOUNDINGS SHOWING A DEEP DENDRITIC GROWTH
ZONE FROM THE SURFACE ON UP TO 700MB. THE BEST CHANCES FOR AN
ACCUMULATING SNOW IS WITH A SYSTEM THAT MAY COME IN ON THURSDAY OR
FRIDAY. THE 19.00Z GFS IS SLOW WITH THIS SYSTEM AND BRINGS IT IN
THURSDAY NIGHT INTO FRIDAY WHILE THE 19.00Z ECMWF HAS IT THROUGH
BY THURSDAY. THE 19.00Z GFS BUFKIT SOUNDINGS ARE EVEN DEEPER WITH
THE DENDRITIC GROWTH ZONE AND LIFT WITH THIS SYSTEM...WHICH COULD
AGAIN LEAD TO A HIGH SNOW TO LIQUID RATIO SNOW. TRENDED LOWER ON
TEMPERATURES ON THURSDAY WITH GUIDANCE SHOWING THIS SYSTEM
TRENDING A BIT FURTHER TO THE SOUTH.
&&
.AVIATION...TODAY AND TONIGHT
551 AM CST SAT JAN 19 2013
ALL EYES ARE ON AN ARCTIC COLD FRONT THAT WILL BLAST THROUGH THE
AREA THIS AFTERNOON. UNTIL THEN...EXPECT PATCHY ALTOCUMULUS WITH
BASES AOA 10KFT. LOOK FOR SOUTHWEST WINDS IN ADVANCE OF THE FRONT
THIS MORNING...THEN SHIFTING TO THE NORTHWEST AND INCREASING INTO
THE 25-35KT RANGE WITH GUSTS INTO THE 40-45KT RANGE AROUND 21Z.
THIS FRONTAL PASSAGE IS ALSO EXPECTED TO PRODUCE MVFR CLOUDS ALONG
WITH SCATTERED SNOW SHOWER ACTIVITY. THESE STRONG WINDS AND
LOCALLY REDUCED VISIBILITIES IN SCATTERED SNOW SHOWER ACTIVITY WILL
LIKELY POSE PROBLEMS FOR BOTH GROUND AND AIRCRAFT OPERATIONS. LOOK
FOR THE STRONG/GUSTY NORTHWEST WINDS TO SUBSIDE AFTER MIDNIGHT
ALONG WITH SCATTERING CLOUDS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
551 AM CST SAT JAN 19 2013
WI...WIND ADVISORY FROM 3 PM THIS AFTERNOON TO MIDNIGHT CST TONIGHT
FOR WIZ017-029-032>034-041>044-053>055-061.
WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM CST SUNDAY FOR
WIZ017-029.
MN...WIND ADVISORY FROM 3 PM THIS AFTERNOON TO MIDNIGHT CST TONIGHT
FOR MNZ079-086>088-094>096.
IA...WIND ADVISORY FROM 3 PM THIS AFTERNOON TO MIDNIGHT CST TONIGHT
FOR IAZ008>011-018-019-029-030.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...DAS
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
912 AM MST SAT JAN 19 2013
.UPDATE...
&&
.SHORT TERM...IN THE WAKE OF LAST NIGHTS WEAK TROF THERE IS STILL
SOME GUSTY WINDS IN THE MOUNTAINS AND FOOTHILLS. THESE WINDS WILL
CONTINUE TO DECREASE THIS AFTERNOON. BASED ON THE MORNING DENVER
SOUNDING...TEMPERATURES MIGHT BE A DEGREE OR TWO COOLER FROM
YESTERDAY WITH SLIGHT COOLING IN THE 600-700MB LAYER. WINDS
EXPECTED TO INCREASE AGAIN LATER TONIGHT ALONG EAST SLOPES AS NEXT
WEAK RIPPLE MOVES THROUGH THE FLOW.
.AVIATION...CURRENT TAFS LOOK GOOD AND STILL PLANNING TO PLAY THE
LONGMONT ANTICYCLONE THIS AFTERNOON WITH A LIGHT EAST TO SOUTHEAST
WIND AT DEN AND APA. BJC MAY STILL SEE A MORE WESTERLY COMPONENT
THIS AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 243 AM MST SAT JAN 19 2013/
SHORT TERM...DRY NW FLOW ALOFT WILL CONTINUE TODAY AND TONIGHT. A
MTN WAVE EARLY THIS MORNING IS ALLOWING FOR SOME GUSTY NWLY WINDS
IN AND NR THE FOOTHILLS WHICH WILL LINGER THRU THE MID MORNING
HOURS BEFORE DECREASING SOME BY MIDDAY. OTHERWISE GUSTY NW WINDS
WILL ALSO OCCUR ALONG AND NR THE WY-NE BORDER ESPECIALLY LATER
THIS MORNING INTO THE AFTN HOURS AS BETTER MIXING DEVELOPS. AS FOR
HIGHS READINGS WILL BE IN THE 50S ACROSS NERN CO. ONCE AGAIN IN
THE HIGHER MTN VALLEYS INVERSIONS WILL LEAD TO WIDE TEMP SPREADS
ESPECIALLY ACROSS ZONE 32.
FOR TONIGHT ANOTHER MTN WAVE MAY DEVELOP AFTER MIDNIGHT LEADING TO
AN INCREASE IN WINDS OVER THE HIGHER MTNS AND FOOTHILLS. AT THIS
TIME IT APPEARS SPEEDS SHOULD STAY BLO HIGHLIGHT CRITERIA.
LONG TERM...NORTHWESTERLY FLOW ALOFT IS PROGGED TO CONTINUE OVER
THE FORECAST AREA SUNDAY AND SUNDAY NIGHT. ON MONDAY...THE FLOW
IS PROGGED TO BECOME NORTH-NORTHWESTERLY AND INCREASE A BIT IN
SPEED. BY TUESDAY MORNING AT 12Z IT WEAKENS AND IS BACK TO A
NORTHWESTERLY DIRECTION. AT THAT TIME AN UPPER RIDGE AXIS IS
LOCATED OVER THE GREAT BASIN. THE SYNOPTIC SCALE ENERGY IS PROGGED
TO BE BENIGN SUNDAY THROUGH MONDAY NIGHT. THE BOUNDARY LAYER FLOW
LOOKS TO BE UPSLOPING FOR THE PLAINS AND FOOTHILLS SUNDAY...WITH
NORMAL DUIRNAL PATTERNS FOR SUNDAY NIGHT INTO MONDAY. LOW LEVEL
TROUHGING EAST OF THE MOUNTAINS SETS UP LATER SUNDAY THROUGH
TUESDAY NIGHT...BUT THE GRADIENT IS PRETTY WEAK. A MIX OF NORMAL
TRENDS TO DOWNSLOPING SHOULD PREVAIL THOSE TWO PERIODS. MOISTURE
CONTINUES TO BE QUITE LIMITED ACCORDING TO THE MODELS. THERE IS A
LITTLE OVER THE PLAINS WITH THE UPSLOPE SUNDAY AFTERNOON AND
EVENING...MORE SO ON THE GFS. THE GFS ALSO SHOWS A TAD IN THE
UPPER LEVELS MONDAY AND MONDAY NIGHT...BUT THAT`S ABOUT IT. THERE
IS NO MEASURABLE PRECIPITATION NOTED ON THE QPF FIELDS FOR THE
FORECAST AREA SUNDAY THROUGH MONDAY NIGHT. NO POPS. FOR
TEMPERATURES...SUNDAY`S HIGHS ARE 4-8 C COLDER THAN TODAY`S
EXPECTED HIGHS. MONDAY`S READINGS WARM UP 3-5 C OVER SUNDAY`S. FOR
THE LATER DAYS...TUESDAY THROUGH FRIDAY...MODELS HAVE PRETTY WEAK
NORTHWESTERLY FLOW ALOFT FOR THE CWA TUESDAY AND WEDNESDAY.
BY THURSDAY...THE ECMWF AND GFS START DEVELOPING AN UPPER TROUGH
NORTH AND NORTHEAST OF COLORADO. THE FLOW ALOFT INCREASES AND IS
ZONAL ON THURSDAY. BY FRIDAY...A MEAN TROUGH IS PROGGED TO COVER
THE EASTERN HALF OF NORTH AMERICA...AND AN UPPER RIDGE IS OVER
THE GREAT BASIN. THE GFS BRINGS SOME MOISTURE OVER THE CWA
THURSDAY AND THURSDAY NIGHT. THE ECMWF DOES NOT. THE OTHER DAYS
ARE PRETTY DRY ON BOTH MODELS. WILL KEEP POPS OUT FOR NOW.
TEMPERATURES REMAIN ABOVE SEASONAL NORMALS THROUGH THE PERIOD.
AVIATION...WEST WINDS HAVE SPREAD ACROSS THE AIRPORT EARLY THIS
MORNING BUT SHOULD BECOME MORE SWLY AFTER SUNRISE. BY 16Z WINDS
MAY BECOME MORE SLY. FOR THIS AFTN THERE IS QUITE A DIFFERENCE IN
WIND FCSTS AS THE HRRR AND RAP INDICATE A LONGMONT ANTI-CYCLONE
DEVELOPING WITH WINDS BECOMING MORE ELY BY EARLY AFTN WHILE THE
NAM HAS A WLY COMPONENT. WITH NWLY FLOW OVER THE CHEYENNE RIDGE
THAT WOULD FAVOR A POTENTIAL ANTI-CYCLONE SO WILL TREND TAF
TOWARDS THE HRRR/RAP SOLUTION. BY EARLY EVENING WINDS SHOULD
GRADUALLY TRENDS TOWARDS DRAINAGE. VFR CONDITIONS WILL BE IN PLACE
TODAY THRU TONIGHT.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...ENTREKIN
LONG TERM....RJK
AVIATION...ENTREKIN
AREA FORECAST DISCUSSION
NWS MIAMI FL
101 PM EST SAT JAN 19 2013
.AVIATION...
LOW LEVEL TROUGH LOCATED NEAR KPBI WILL CONTINUE TO MOVE NORTHWARD
UP THE COAST THROUGH THE DAY. RAIN HAS ENDED SOUTH OF KFXE...AND
VFR CONDITIONS ARE EXPECTED SOUTH OF KFXE THROUGH TONIGHT. OLD
FRONTAL BOUNDARY REMAINS JUST SOUTH OF THE REGION AND MOSTLY
CLOUDY TO CLOUDY SKIES WILL PREVAIL THROUGH THE END OF THE PERIOD.
SOME LOW CIGS/VIS MAY BE POSSIBLE FOR KAPF...KFXE...AND KTMB
TONIGHT AS WINDS BECOME CALM AND A LAND BREEZE SETS UP.
OTHERWISE...LIGHT NORTHEAST WINDS ARE EXPECTED THIS
AFTERNOON...AND AGAIN AFTER 15Z SUNDAY.
&&
.PREV DISCUSSION... /ISSUED 1104 AM EST SAT JAN 19 2013/
UPDATE...LOWERED POPS FOR BASED ON RADAR TRENDS. LOOKS LIKE WE
WILL HAVE PREDOMINATELY SCATTERED SHOWER ACTIVITY FROM NE BROWARD
AND ALONG THE PALM BEACH COAST WITH A SLIGHT CHANCE OF SHOWERS
ELSEWHERE THROUGH THE DAY. SOME SUNSHINE NOW SOUTH WITH BREAKS
DEVELOPING AT OTHER LOCALES SO IT LOOKS LIKE HIGHS ARE ON TRACK.
/GREGORIA
PREV DISCUSSION... /ISSUED 809 AM EST SAT JAN 19 2013/
UPDATE...UPDATED MOST ELEMENTS FOR CURRENT TRENDS. AREA OF LIGHT
RAIN NOW IS FOCUSED ACROSS METRO BROWARD. HRRR AND NAM SHOW A
GRADUALLY NORTHWARD SHIFT ALONG THE ATLANTIC COAST WITH TIME
TODAY. NAM KEEPS A SOLID AREA OF QPF MOVING UP THE PALM BEACH
COAST WHILE THE HRRR LESSENS QPF THIS AFTERNOON, SO TOOK A MIDDLE
OF THE ROAD APPROACH. LOOKS LIKE TWO WEAK LOWS HAVE
DEVELOPED...ONE OVER OUR ATLANTIC WATERS AND ANOTHER CLEARLY
DEFINED ONE ON SAT IMAGERY OVER THE GULF OFF THE SW FL COAST.
THESE FEATURES WILL KEEP EXTENSIVE CLOUDINESS OVER THE AREA TODAY,
BUT WITH A FEW BREAKS EXPECTED IN THE AFTERNOON. THIS SHOULD
MANAGE TO ALLOW TEMPS TO REACH FORECASTED HIGHS, BUT WILL NEED TO
MONITOR THIS BC IF THERE ARE NO BREAKS, HIGHS MAY BE A TAD TOO
WARM. IT DOESN`T TAKE MUCH BREAKS TO ACHIEVE OUR WARMER HIGHS
ADVERTISED SO HAVE KEPT THE FCST AS IS FOR NOW FOR MAX T.
/GREGORIA
PREV DISCUSSION... /ISSUED 645 AM EST SAT JAN 19 2013/
AVIATION...
MOSTLY CLOUDY SKIES WILL PREVAIL ACROSS SOUTH FLORIDA THIS
MORNING. LIGHT DRAINAGE FLOW IS STILL PRESENT ACROSS THE EASTERN
TERMINALS...BUT WILL SHIFT TO THE EAST BY 19/18Z. VCSH WAS KEPT
AS PREVAILING AT ALL EASTERN TERMINALS EXCEPT FOR KPBI. SHOWERS
WILL CONTINUE DEVELOPING THIS AFTERNOON...FOR THIS REASON KEPT
VCSH AT ALL EASTERN TERMINALS THROUGH THE EVENING. FOR KAPF...DRY
CONDITIONS EXPECTED THROUGH THE PERIOD. WIND FLOW WILL BE WEAK
ENOUGH TO ALLOW FOR THE SEABREEZE TO DEVELOP BY 19/19Z.
PREV DISCUSSION... /ISSUED 338 AM EST SAT JAN 19 2013/
DISCUSSION...
AN ACTIVE NIGHT ALONG THE ATLANTIC COAST HAS BEEN THE CASE
THIS MORNING. SHOWERS HAVE BEEN DEVELOPING ALL NIGHT ALONG A STALLED
FRONTAL BOUNDARY, LAYING JUST TO THE SOUTHEAST OF THE CWA. MODELS
ARE SHOWING A WEAK LOW FORMING ALONG THIS BOUNDARY, WHICH WILL ACT
AS THE FOCAL POINT FOR CONTINUED DEVELOPMENT OF SHOWERS TODAY,
MAINLY SCATTERED IN NATURE. THIS ACTIVITY WILL CONTINUE INTO THE
EVENING HOURS AND BEGIN TO DIE DOWN TONIGHT. THE LOW THEN LOOKS TO
FALL APART LATER ON SUNDAY. THERE LOOKS TO BE SOME UPPER LEVEL
SUPPORT FOR THE SHOWERS TO BE NORTH, AS A JET STREAK WILL MOVE IN
AND THE LEFT EXIT REGION WILL BE AROUND THE JAX AREA. KEPT A
MENTION OF MAINLY A SLIGHT CHANCE OF COASTAL SHOWERS FOR THE NEXT
FEW DAYS.
FOR THE BEGINNING OF THE WEEK, A COLD FRONT, WITH AN ARCTIC PUSH,
MOVES THROUGH THE CWA. THERE IS LITTLE EXPECTED IN THE WAY OF
PRECIPITATION, BUT IT SHOULD ALLOW TEMPERATURES COOL SOMEWHAT. IT
WILL KEEP THE HIGH TEMPERATURES IN THE 70S THIS WEEK, WHICH IS NOT
MUCH DIFFERENT THAN THE WEEKEND. HOWEVER, THE LOW TEMPERATURES
WILL BE ABLE TO DROP INTO THE MID TO UPPER 40S IN THE NORTHWEST
ZONES OF THE CWA. THE MAIN COLD AIR MASS DOES LOOK TO REMAIN WELL
TO THE NORTH, SO TEMPERATURES ALONG THE COAST AND FAR SOUTH
FLORIDA ARE EXPECTED TO ONLY DROP INTO THE LOW 60S, MAYBE UPPER
50S.
BEYOND THE COLD FRONT, HIGH PRESSURE WILL SET UP ONCE AGAIN, WHICH
WILL KEEP THE WEATHER QUIET FROM TUESDAY NIGHT THROUGH THE END OF
THE WEEK, WITH HIGH TEMPERATURES SLOWLY RISING THROUGH THE WEEK.
FIRE WEATHER...
A STALLED FRONTAL BOUNDARY AND A DEVELOPING LOW PRESSURE SYSTEM
NEAR THE AREA, WILL KEEP SHOWERS DEVELOPING ALONG THE ATLANTIC
COAST AND KEEP ENOUGH SURFACE MOISTURE IN PLACE TO KEEP RH VALUES
ABOVE ANY CRITICAL LEVELS. WINDS LOOK AS THOUGH THEY WILL BE
LIGHTER THE ORIGINALLY THOUGH FOR THE NEXT COUPLE OF DAYS, WHICH
WILL MEAN THEY WILL ALSO NOT REACH ANY CRITICAL LEVELS FOR THE
NEXT SEVERAL DAYS. THERE WILL BE A COLD FRONT NEXT WEEK, WHICH MAY
BRING SOME GUTSY WINDS AND A SLIGHT CHANCE FOR A SHOWER. BEHIND
THIS FRONT, A MUCH DRIER AIR MASS IS EXPECTED. MIN RHS MAY DROP
DOWN INTO THE MID 30 PERCENT RANGE IN THE NORTHWESTERN FIRE
WEATHER ZONES. HOWEVER, WINDS ARE CURRENTLY EXPECTED TO REMAIN
BELOW THRESHOLDS AT THIS TIME.
MARINE...
FOR THE GULF WATERS...SEAS ARE EXPECTED TO STEADILY SUBSIDE THE
REMAINDER OF TODAY AS THE WINDS ACROSS THE REGION ARE FORECAST TO
BECOME MORE NORTHEASTERLY AND SLOWLY SUBSIDE.
FOR THE ATLANTIC WATERS...AS MODERATE NORTH TO NORTHEAST WINDS
CONTINUE TO BUILD INTO THE REGION TODAY...THE ATLANTIC AND GULF
STREAM SEAS ARE EXPECTED TO INCREASE THE REMAINDER OF TODAY THEN
FORECAST TO BUILD QUICKLY TO ADVISORY LEVELS BY EARLY SATURDAY
MORNING...MAINLY TO THE EAST OF PALM BEACH COUNTY...AND TO
PERSIST THROUGH SATURDAY EVENING. A SMALL CRAFT ADVISORY IS IN
EFFECT FOR THE ATLANTIC WATERS AT 00Z SUNDAY THIS EVENING.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 66 78 65 78 / 30 20 20 20
FORT LAUDERDALE 67 79 67 79 / 30 20 20 20
MIAMI 66 80 66 80 / 30 20 20 20
NAPLES 63 77 63 76 / 10 10 10 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR COASTAL
WATERS FROM DEERFIELD BEACH TO OCEAN REEF, FL OUT 20 NM-
COASTAL WATERS FROM JUPITER INLET TO DEERFIELD BEACH, FL
OUT 20 NM-WATERS FROM DEERFIELD BEACH TO OCEAN REEF, FL
EXTENDING FROM 20 NM TO THE TERRITORIAL WATERS OF THE
BAHAMAS-WATERS FROM JUPITER INLET TO DEERFIELD BEACH, FL
EXTENDING FROM 20 NM TO 60 NM.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...57/DG
AVIATION/RADAR...84/AK
AREA FORECAST DISCUSSION
NWS MIAMI FL
1104 AM EST SAT JAN 19 2013
.UPDATE...LOWERED POPS FOR BASED ON RADAR TRENDS. LOOKS LIKE WE
WILL HAVE PREDOMINATELY SCATTERED SHOWER ACTIVITY FROM NE BROWARD
AND ALONG THE PALM BEACH COAST WITH A SLIGHT CHANCE OF SHOWERS
ELSEWHERE THROUGH THE DAY. SOME SUNSHINE NOW SOUTH WITH BREAKS
DEVELOPING AT OTHER LOCALES SO IT LOOKS LIKE HIGHS ARE ON TRACK.
/GREGORIA
&&
.PREV DISCUSSION... /ISSUED 809 AM EST SAT JAN 19 2013/
UPDATE...UPDATED MOST ELEMENTS FOR CURRENT TRENDS. AREA OF LIGHT
RAIN NOW IS FOCUSED ACROSS METRO BROWARD. HRRR AND NAM SHOW A
GRADUALLY NORTHWARD SHIFT ALONG THE ATLANTIC COAST WITH TIME
TODAY. NAM KEEPS A SOLID AREA OF QPF MOVING UP THE PALM BEACH
COAST WHILE THE HRRR LESSENS QPF THIS AFTERNOON, SO TOOK A MIDDLE
OF THE ROAD APPROACH. LOOKS LIKE TWO WEAK LOWS HAVE
DEVELOPED...ONE OVER OUR ATLANTIC WATERS AND ANOTHER CLEARLY
DEFINED ONE ON SAT IMAGERY OVER THE GULF OFF THE SW FL COAST.
THESE FEATURES WILL KEEP EXTENSIVE CLOUDINESS OVER THE AREA TODAY,
BUT WITH A FEW BREAKS EXPECTED IN THE AFTERNOON. THIS SHOULD
MANAGE TO ALLOW TEMPS TO REACH FORECASTED HIGHS, BUT WILL NEED TO
MONITOR THIS BC IF THERE ARE NO BREAKS, HIGHS MAY BE A TAD TOO
WARM. IT DOESN`T TAKE MUCH BREAKS TO ACHIEVE OUR WARMER HIGHS
ADVERTISED SO HAVE KEPT THE FCST AS IS FOR NOW FOR MAX T.
/GREGORIA
PREV DISCUSSION... /ISSUED 645 AM EST SAT JAN 19 2013/
AVIATION...
MOSTLY CLOUDY SKIES WILL PREVAIL ACROSS SOUTH FLORIDA THIS
MORNING. LIGHT DRAINAGE FLOW IS STILL PRESENT ACROSS THE EASTERN
TERMINALS...BUT WILL SHIFT TO THE EAST BY 19/18Z. VCSH WAS KEPT
AS PREVAILING AT ALL EASTERN TERMINALS EXCEPT FOR KPBI. SHOWERS
WILL CONTINUE DEVELOPING THIS AFTERNOON...FOR THIS REASON KEPT
VCSH AT ALL EASTERN TERMINALS THROUGH THE EVENING. FOR KAPF...DRY
CONDITIONS EXPECTED THROUGH THE PERIOD. WIND FLOW WILL BE WEAK
ENOUGH TO ALLOW FOR THE SEABREEZE TO DEVELOP BY 19/19Z.
PREV DISCUSSION... /ISSUED 338 AM EST SAT JAN 19 2013/
DISCUSSION...
AN ACTIVE NIGHT ALONG THE ATLANTIC COAST HAS BEEN THE CASE
THIS MORNING. SHOWERS HAVE BEEN DEVELOPING ALL NIGHT ALONG A STALLED
FRONTAL BOUNDARY, LAYING JUST TO THE SOUTHEAST OF THE CWA. MODELS
ARE SHOWING A WEAK LOW FORMING ALONG THIS BOUNDARY, WHICH WILL ACT
AS THE FOCAL POINT FOR CONTINUED DEVELOPMENT OF SHOWERS TODAY,
MAINLY SCATTERED IN NATURE. THIS ACTIVITY WILL CONTINUE INTO THE
EVENING HOURS AND BEGIN TO DIE DOWN TONIGHT. THE LOW THEN LOOKS TO
FALL APART LATER ON SUNDAY. THERE LOOKS TO BE SOME UPPER LEVEL
SUPPORT FOR THE SHOWERS TO BE NORTH, AS A JET STREAK WILL MOVE IN
AND THE LEFT EXIT REGION WILL BE AROUND THE JAX AREA. KEPT A
MENTION OF MAINLY A SLIGHT CHANCE OF COASTAL SHOWERS FOR THE NEXT
FEW DAYS.
FOR THE BEGINNING OF THE WEEK, A COLD FRONT, WITH AN ARCTIC PUSH,
MOVES THROUGH THE CWA. THERE IS LITTLE EXPECTED IN THE WAY OF
PRECIPITATION, BUT IT SHOULD ALLOW TEMPERATURES COOL SOMEWHAT. IT
WILL KEEP THE HIGH TEMPERATURES IN THE 70S THIS WEEK, WHICH IS NOT
MUCH DIFFERENT THAN THE WEEKEND. HOWEVER, THE LOW TEMPERATURES
WILL BE ABLE TO DROP INTO THE MID TO UPPER 40S IN THE NORTHWEST
ZONES OF THE CWA. THE MAIN COLD AIR MASS DOES LOOK TO REMAIN WELL
TO THE NORTH, SO TEMPERATURES ALONG THE COAST AND FAR SOUTH
FLORIDA ARE EXPECTED TO ONLY DROP INTO THE LOW 60S, MAYBE UPPER
50S.
BEYOND THE COLD FRONT, HIGH PRESSURE WILL SET UP ONCE AGAIN, WHICH
WILL KEEP THE WEATHER QUIET FROM TUESDAY NIGHT THROUGH THE END OF
THE WEEK, WITH HIGH TEMPERATURES SLOWLY RISING THROUGH THE WEEK.
FIRE WEATHER...
A STALLED FRONTAL BOUNDARY AND A DEVELOPING LOW PRESSURE SYSTEM
NEAR THE AREA, WILL KEEP SHOWERS DEVELOPING ALONG THE ATLANTIC
COAST AND KEEP ENOUGH SURFACE MOISTURE IN PLACE TO KEEP RH VALUES
ABOVE ANY CRITICAL LEVELS. WINDS LOOK AS THOUGH THEY WILL BE
LIGHTER THE ORIGINALLY THOUGH FOR THE NEXT COUPLE OF DAYS, WHICH
WILL MEAN THEY WILL ALSO NOT REACH ANY CRITICAL LEVELS FOR THE
NEXT SEVERAL DAYS. THERE WILL BE A COLD FRONT NEXT WEEK, WHICH MAY
BRING SOME GUTSY WINDS AND A SLIGHT CHANCE FOR A SHOWER. BEHIND
THIS FRONT, A MUCH DRIER AIR MASS IS EXPECTED. MIN RHS MAY DROP
DOWN INTO THE MID 30 PERCENT RANGE IN THE NORTHWESTERN FIRE
WEATHER ZONES. HOWEVER, WINDS ARE CURRENTLY EXPECTED TO REMAIN
BELOW THRESHOLDS AT THIS TIME.
MARINE...
FOR THE GULF WATERS...SEAS ARE EXPECTED TO STEADILY SUBSIDE THE
REMAINDER OF TODAY AS THE WINDS ACROSS THE REGION ARE FORECAST TO
BECOME MORE NORTHEASTERLY AND SLOWLY SUBSIDE.
FOR THE ATLANTIC WATERS...AS MODERATE NORTH TO NORTHEAST WINDS
CONTINUE TO BUILD INTO THE REGION TODAY...THE ATLANTIC AND GULF
STREAM SEAS ARE EXPECTED TO INCREASE THE REMAINDER OF TODAY THEN
FORECAST TO BUILD QUICKLY TO ADVISORY LEVELS BY EARLY SATURDAY
MORNING...MAINLY TO THE EAST OF PALM BEACH COUNTY...AND TO
PERSIST THROUGH SATURDAY EVENING. A SMALL CRAFT ADVISORY IS IN
EFFECT FOR THE ATLANTIC WATERS AT 00Z SUNDAY THIS EVENING.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 77 66 78 65 / 40 30 20 20
FORT LAUDERDALE 78 67 79 67 / 20 30 20 20
MIAMI 79 66 80 66 / 20 30 20 20
NAPLES 75 63 77 63 / 20 10 10 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR COASTAL
WATERS FROM DEERFIELD BEACH TO OCEAN REEF, FL OUT 20 NM-
COASTAL WATERS FROM JUPITER INLET TO DEERFIELD BEACH, FL
OUT 20 NM-WATERS FROM DEERFIELD BEACH TO OCEAN REEF, FL
EXTENDING FROM 20 NM TO THE TERRITORIAL WATERS OF THE
BAHAMAS-WATERS FROM JUPITER INLET TO DEERFIELD BEACH, FL
EXTENDING FROM 20 NM TO 60 NM.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DULUTH MN
336 PM CST SAT JAN 19 2013
.SHORT TERM.../NOW - SUNDAY NIGHT/
THE MAIN CHALLENGES FOR THIS FORECAST INCLUDE 1) THE THREAT OF
STRONG WINDS ACROSS THE NORTHLAND THROUGH TONIGHT IN THE WAKE OF A
STRONG COLD FRONT...2) THE THREAT OF LAKE EFFECT SNOW FOR THE
GOGEBIC RANGE AND 3) THE THREAT OF HAZARDOUS WIND CHILL VALUES
TONIGHT AND TOMORROW MORNING. THE MODELS ARE IN REASONABLE
AGREEMENT...SO LEANED ON A BLEND. THE LATEST HIGH RESOLUTIONS
MODELS INDICATE STRONG WIND GUSTS ALONG THE NORTH SHORE
TONIGHT...SO ISSUED A WIND ADVISORY FOR THE NORTH SHORE THAT IS
SEPARATE FROM THE WIND ADVISORY FOR PARTS OF EAST CENTRAL
MINNESOTA AND NORTHWESTERN WISCONSIN.
AT 2130Z...THERE WAS A STRONG CLIPPER SYSTEM CENTERED OVER UPPER
PENINSULA MICHIGAN. THE NORTHLAND HAD STRONG W TO NW WINDS...WHICH
WERE GENERALLY STRENGTHENING IN THE WAKE OF THE CLIPPER. THE
NORTHLAND HAD CLOUDY SKIES. TEMPERATURES RANGED FROM THE LOW TO
MID 30S IN THE FAR EASTERN FA TO THE SINGLE DIGITS IN THE FAR NW
FA.
THROUGH TONIGHT...THE CLIPPER SYSTEM WILL CONTINUE TO MOVE EAST.
THE STRONG NW WINDS CARRYING QUITE THE ARCTIC BLAST WILL CONTINUE
TO INCREASE LATE THIS AFTERNOON...PERHAPS PEAK EARLY THIS
EVENING...THEN GRADUALLY RELAX THROUGH THE REST OF THE NIGHT. THE
EXCEPTION COULD BE ALONG THE IMMEDIATE NORTH SHORE WHERE
WINDS...ESPECIALLY GUSTS...WILL LIKELY STRENGTHEN INTO THIS
EVENING AND PEAK AROUND MIDNIGHT. THIS IS BASED ON THE LATEST RUNS
OF THE HRRR AND LOCAL WRF MODELS. THOSE MODELS SUGGEST WIND GUSTS
UP TO 50 KT. NOT SURE IF THE GUSTS WILL BE THAT STRONG...BUT
DECIDED TO ISSUE A WIND ADVISORY FOR THE NORTH SHORE THROUGH 09Z
TONIGHT FOR GUSTS UP TO 50 MPH. THE CURRENT WIND ADVISORY FROM
SOUTHERN CASS COUNTY TO BURNETT COUNTY STILL LOOKS GOOD THROUGH
03Z. WIND CHILL VALUES WILL PLUMMET TONIGHT WITH THE FALLING
TEMPERATURES...AND THE CURRENT WIND CHILL ADVISORY FOR TONIGHT AND
INTO TOMORROW MORNING DOES NOT NEED ANY CHANGES. LAKE EFFECT SNOW
SHOWERS WILL INCREASE ACROSS THE SOUTH SHORE TONIGHT...ESPECIALLY
THE GOGEBIC RANGE IN IRON COUNTY...AS THE STRONG COLD NW WINDS
DEVELOP OVER WESTERN LAKE SUPERIOR. WILL NOT BE MAKING CHANGES TO
THE CURRENT LAKE EFFECT SNOW ADVISORY FOR IRON COUNTY AS PARTS OF
THE COUNTY COULD GET SEVERAL INCHES OF SNOW THROUGH SUNDAY
MORNING.
SUNDAY AND SUNDAY NIGHT...IT WILL BE A PARTICULARLY COLD DAY
ACROSS THE NORTHLAND WITH MUCH OF REGION NOT EVEN REACHING ZERO
DEGREES. LAKE EFFECT SNOW SHOWERS WILL LIKELY CONTINUE FOR THE
SOUTH SHORE. ANOTHER WIND CHILL ADVISORY OR WARNING WILL LIKELY BE
NEEDED. SOME PARTS OF FAR NORTHERN MINNESOTA COULD HAVE WIND CHILL
VALUES APPROACHING 50 DEGREES BELOW ZERO.
.LONG TERM.../MONDAY - FRIDAY NIGHT/
MODELS SHOWING GOOD AGREEMENT THAT THE CORE OF COLDEST H85-H50 AIR
PUSHES INTO THE NORTHERN AREAS EARLY MONDAY MORNING...SWINGING
THROUGH THE NORTHLAND THROUGH 00Z TUESDAY. AT THIS TIME WIND CHILL
VALUES IN THE NEIGHBORHOOD OF NEGATIVE 30 TO 50 ARE EXPECTED EARLY
MONDAY MORNING WITH VERY LITTLE IMPROVEMENT THROUGH THE DAY. THE
LATEST ECM/GFS SUGGEST THAT THE WRN LAKE SUPERIOR REGION REMAINS ON
THE BACK EDGE OF THE ARCTIC AIR MASS THROUGH MUCH OF THE WEEK WITH A
PERSIST ANT NORTHWEST FLOW. HAVE KEPT POPS ACROSS THE SOUTH SHORE
ZONES FOR AN ONGOING PERIOD OF LAKE EFFECT SNOW AS WELL.
&&
.AVIATION.../18Z TAF ISSUANCE/
MVFR CIGS WITH -SN AND BLSN WILL PREVAIL THROUGH 00Z..THEN
GRADUALLY IMPROVING TO VFR GENERALLY AFTER 06Z. NORTHWEST WINDS
WILL INCREASE THROUGH THE AFTERNOON WITH GUSTS OF 30 TO 35 KTS
COMMON ACROSS THE FORECAST ARES THROUGH THE 20Z TO 06Z PERIOD.
HIGHER GUSTS AROUND 40 KT WILL BE POSSIBLE AT THE KBRD AND KDLH
TERMINALS AROUND 00Z...WITH THE STRONGEST GUSTS OF 45-50 KT
EXPECTED ALONG THE NORTH SHORE OF LAKE SUPERIOR AFTER 03Z.
&&
.POINT TEMPS/POPS...
DLH -12 0 -21 -9 / 10 10 10 10
INL -19 -5 -30 -12 / 10 10 10 10
BRD -12 1 -22 -10 / 10 10 10 0
HYR -5 3 -18 -7 / 20 10 10 10
ASX -1 6 -13 -4 / 60 30 50 40
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WIND CHILL ADVISORY FROM 9 PM THIS EVENING TO NOON CST SUNDAY
FOR MNZ010>012-018>021-025-026-033>038.
WIND ADVISORY UNTIL 9 PM CST THIS EVENING FOR MNZ033-034-036-038.
WIND ADVISORY UNTIL 3 AM CST SUNDAY FOR MNZ020-021.
WI...WIND ADVISORY UNTIL 9 PM CST THIS EVENING FOR WIZ006.
WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST SUNDAY FOR
WIZ001>004-006>009.
LAKE EFFECT SNOW ADVISORY UNTIL NOON CST SUNDAY FOR WIZ004.
LS...NONE.
&&
$$
SHORT TERM...GROCHOCINSKI
LONG TERM....GRANING
AVIATION...GRANING
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
306 PM CST SAT JAN 19 2013
.DISCUSSION...
FORECAST CONCERNS FOR THE 7 DAY PERIOD AHEAD ARE MAINLY CONFINED
TO THE NEXT 48 HOURS. THE ARCTIC BOUNDARY IS PASSING THROUGH THE
CWA AS FORECAST THIS AFTERNOON. SUSTAINED WINDS NEAR 30 MPH WITH
GUSTS REACHING 55 MPH HAVE BEEN COMMON IN THE WAKE OF THE FRONT.
THE BOUNDARY IS MOVING THROUGH THE TWIN CITIES AT THIS TIME. THE
FRONT WILL BE PAST KEAU TO THE IA BORDER BY 5 PM. THE WIND
ADVISORY WILL REMAIN IN EFFECT CWA-WIDE THROUGH 9 PM. SOME FLURRY
ACTIVITY CAN NOT BE RULED OUT AS WELL IN THE CLOUD STREETS THAT
STRETCH BACK TO THE CANADIAN BORDER. OF GREATER CONCERN...WE
DEFINITELY HAVE DRIFTING SNOW ACROSS THE NW CWA AROUND KAXN BASED
ON MULTIPLE WEB CAMS. THE VISIBILITY IS NOT TOO BAD...BUT IT DOES
BECOME MUCH WORSE NW OF OUR CWA TOWARDS FERGUS FALLS AND FARGO.
HAVE ADDED BLOWING SNOW TO THE GRIDS FOR THE LATE AFTERNOON/
EVENING HOURS TO AREAS WEST OF A KLXL TO KOVL LINE ALONG WITH
ISSUING AN SPS.
AS THE EVENING PROGRESSES AND TEMPERATURES CONTINUE TO
PLUMMET...WIND CHILL VALUES BECOME CRITICAL ACROSS CENTRAL MN AND
PARTS OF WEST CENTRAL WI. THE CURRENT WIND CHILL ADVISORIES LOOK
OKAY WITH THE ONE ACROSS CENTRAL MN BEGINNING AFTER 9 PM AND IN
WEST CENTRAL WI AFTER MIDNIGHT. AT THIS POINT...THE WIND CHILL
VALUES OF 25 BELOW ARE MOST WIDESPREAD ACROSS CENTRAL MN
OVERNIGHT AND SUNDAY MORNING.
A DISTURBANCE MOVING SOUTHEAST ACROSS THE PLAINS ON SUNDAY WILL
BRING A PERIOD OF SNOW THAT WILL BRUSH WEST CENTRAL THROUGH SOUTH
CENTRAL MN. THE MODELS HAVE BEEN PRETTY CONSISTENT WITH THIS
FEATURE FOR THE PAST FEW DAYS ALTHOUGH A SLIGHT SOUTHWEST DRIFT
HAS OCCURRED WITH TIME. THE SREF SHOWS 18 OF 21 MEMBERS MEASURING
ALONG AND SOUTH THE MN RIVER VALLEY. AS A RESULT...RAISED POPS IN
THESE AREAS TO 60-80 PERCENT BASED ON THE ABOVE ALONG WITH THE MID
LEVEL FRONTOGENESIS AND THE LOW CONDENSATION PRESSURE DEFICITS/
ADIABATIC OMEGA MOVING THROUGH ON THE 280K SURFACE. CARIBOU SNOW
TECHNIQUE PRETTY CONSISTENT AS WELL BETWEEN THE NAM/GFS AND SREF
ON SNOW AMOUNTS BEING AROUND A HALF INCH...ALTHOUGH THE GRIDS
REFLECT FROM A HALF INCH TO NEARLY AN INCH. ITS INTERESTING TO NOTE
THAT THE SATURATED COLUMN ACROSS THE SW CWA ON SUNDAY IS AT OR
BELOW -18 DEG C. THIS WOULD BE MORE PLATES AND COLUMNS WITH THE
DENDRITIC DEVELOPMENT.
THE HEART OF THE ARCTIC AIR WILL BE FROM SUNDAY NIGHT THROUGH
TUESDAY. MORE WIND CHILL PRODUCTS WILL LIKELY BE NEEDED SUNDAY
NIGHT AND MONDAY WITH CURRENT GRIDDED WIND CHILL VALUES IN THE 25
BELOW TO 45 BELOW ZERO RANGE. OVERNIGHT LOWS SUNDAY NIGHT AND
MONDAY NIGHT PRETTY MUCH BETWEEN 10 BELOW AND 20 BELOW ZERO ACROSS
THE CWA. THE HIGHS ON MONDAY ARE STILL PROGGED BELOW ZERO ACROSS
THE ENTIRE CWA.
THERE WILL BE SLOW MODERATION TO THE TEMPERATURES IN THE MID WEEK
PERIOD. THERE ALSO REMAINS A CHANCE OF LIGHT SNOW FROM THURSDAY
INTO FRIDAY AS A PACIFIC SHORT WAVE MOVES THROUGH. ONE OF THE
PROBLEMS SEEN WITH THIS SYSTEM IS THAT THE MODELS ARE TRYING TO
SHOW BOTH NORTHERN AND SOUTHERN STREAM ENERGY. WE COULD END UP
WITH A SPLIT PRECIPITATION PATTERN ACROSS THE UPPER MISSISSIPPI
VALLEY REGION. HENCE...CHANCE POPS CONTINUE WITH LOW CONFIDENCE ON
THE OUTCOME. IT WILL LIKELY TURN COLD AGAIN HEADING INTO NEXT
WEEKEND IN THE WAKE OF THIS SYSTEM WITH BELOW ZERO TEMPERATURES
FOR SATURDAY MORNING.
&&
.AVIATION... /18Z TAF ISSUANCE/
SFC LOW NOW MOVING OVER LK SUPERIOR...WITH THE ARCTIC COLD FRONT
NOW STARTING ON A TEAR SOUTH ACROSS MN. WAS INITIALLY THINKING OF
SCALING GUSTS BACK SOME...SINCE GUSTS ACROSS NRN MN/NODAK WERE
ONLY GUSTING IN THE MID 30S...BUT AS OBS AROUND 1730Z STARTED
ROLLING...STARTED TO SEE GUSTS OVER 40 KTS ACROSS WEST CENTRAL MN
RIGHT BEHIND THE BOUNDARY...SO LEFT BIG GUSTS IN PLACE. STILL
EXPECT A 2 OR 3 HOUR WINDOW WITH SUSTAINED WINDS 30-35 KTS WITH
GUSTS 40 TO 45 KTS IMMEDIATELY BEHIND THE FRONT...BEFORE SUSTAINED
SPEEDS AND GUSTS SETTLE DOWN ABOUT 10 KTS. FRONT ALSO COMING DOWN
WITH MVFR CIGS BETWEEN 010 AND 020. THESE CLOUDS WILL REMAIN IN
PLACE THROUGH THE AFTERNOON...BUT CLEARING IS SEEN MOVING SOUTH
ACROSS NODAK THIS AFTERNOON. CURRENTLY CLOCKING THIS CLEARING
MOVING SOUTH AT ABOUT 50 KTS...SO A RETURN TO VFR CONDS MAY COME
ABOUT FASTER THAN CURRENTLY INDICATED. THIS TREND TO VFR CIGS IS
SUPPORTED BY THE SREF...WHICH HAS MUCH OF THE MPX CWA VFR
OVERNIGHT...BEFORE BRINGING ANOTHER ROUND OF MVFR CIGS IN FROM THE
DAKOTAS LATE TONIGHT. AS FOR WX...THERE WILL BE TWO CHANCES FOR
SNOW. FIRST WILL BE BEHIND THE COLD FRONT THIS AFTERNOON...THOUGH
THIS LOOKING LESS LIKELY OUTSIDE OF CENTRAL MN. RAP SOUNDINGS SHOW
POST FRONTAL CLOUD LAYER REACHING UP INTO THE SNOW GROWTH ZONE
NORTH...BUT AS YOU HEAD TOWARD MSP/EAU...THE POST FRONTAL CLOUD
LAYER IS FORECAST TO BE TOO WARM TO GENERATE ICE CRYSTALS...SO CUT
BACK ON SNOW MENTION OUTSIDE OF CENTRAL MN. SECOND CHANCE WILL
COME TONIGHT AS AN UPPER WAVE MOVES ACROSS AN ELEVATED FRONTAL
BOUNDARY ACROSS SW MN. MOST OF THE SNOW LOOKS TO STAY SW OF MPX
TERMINALS...THOUGH RWF LOOKS TO GET A PERIOD OF -SN IN THE
MORNING.
KMSP...MVFR CIGS ALREADY MOVING INTO THE NW METRO AND SHOULD BE IN
AT MSP WITHIN THE FIRST HOUR. WILL START SEEING GUSTS PICK UP WITH
THE ARRIVAL OF THE CLOUDS...THOUGH GUSTS NEAR 40 KTS ARE TRAILING
THE CLOUDS BY A BIT...THOUGH MAY SEE STRONGER GUSTS SHOW UP A BIT
EARLIER THAN 22Z. ALSO PULLED BACK ON SNOW BASED ON WARMER
FORECAST CLOUD LAYER...BUT LOOKING AT IR...IS A NICE BAND OF
COOLER TOPS MOVING SOUTH ACROSS CENTRAL MN AT THE MOMENT. IF THIS
CAN HOLD TOGETHER...MAY NEED TO MENTION AN IFR VIS MENTION IN -SN
BETWEEN 21Z AND 23Z. SREF HAS A GOOD HANDEL ON CLEARING CURRENTLY
MOVING ACROSS NODAK...SO FOLLOWED IT IN BRINGING VFR CONDITION
BACK IN TONIGHT. SNOW MOVING INTO SW MN LOOKS TO REMAIN WELL SW OF
MSP...BUT CAN NOT RULE OUT A FLURRY OR TWO WITH MVFR CONDS MOVING
BACK IN BY SUNDAY AFTERNOON.
/OUTLOOK FOR KMSP/
MON...MVFR CIGS POSSIBLE EARLY. WINDS NW 10 KTS.
TUE...VFR. WINDS W 5 KTS.
WED...VFR. WINDS SW 5 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WIND ADVISORY UNTIL 9 PM CST THIS EVENING FOR ANOKA-BENTON-BLUE
EARTH-BROWN-CARVER-CHIPPEWA-CHISAGO-DAKOTA-DOUGLAS-
FARIBAULT-FREEBORN-GOODHUE-HENNEPIN-ISANTI-KANABEC-
KANDIYOHI-LAC QUI PARLE-LE SUEUR-MARTIN-MCLEOD-MEEKER-MILLE
LACS-MORRISON-NICOLLET-POPE-RAMSEY-REDWOOD-RENVILLE-RICE-
SCOTT-SHERBURNE-SIBLEY-STEARNS-STEELE-STEVENS-SWIFT-TODD-
WASECA-WASHINGTON-WATONWAN-WRIGHT-YELLOW MEDICINE.
WIND CHILL ADVISORY FROM 9 PM THIS EVENING TO 11 AM CST SUNDAY
FOR BENTON-DOUGLAS-ISANTI-KANABEC-MILLE LACS-MORRISON-POPE-
SHERBURNE-STEARNS-STEVENS-TODD.
WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 11 AM CST SUNDAY
FOR ANOKA-CHISAGO.
WI...WIND ADVISORY UNTIL 9 PM CST THIS EVENING FOR BARRON-CHIPPEWA-
DUNN-EAU CLAIRE-PEPIN-PIERCE-POLK-RUSK-ST. CROIX.
WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 11 AM CST SUNDAY
FOR BARRON-CHIPPEWA-DUNN-POLK-RUSK-ST. CROIX.
&&
$$
RAH/MPG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1240 PM CST SAT JAN 19 2013
.UPDATE...
18Z AVIATION DISCUSSION ADDED BELOW.
&&
UPDATE...
/ISSUED 1043 AM CST SAT JAN 19 2013/
COUPLE OF CHANGES MADE TO GRIDS THIS MORNING. BIGGEST CHANGE WAS
TO LOWER POPS FOR THIS AFTERNOON...WITH POPS NOW UNDER 50% WITH
SCT SNOW SHOWERS WORDING NOTED. THIS WAS BASED ON FORECAST
SOUNDINGS FROM THE RAP. YES WE ARE STILL SEEING AGGRESSIVE CAA
WITH UNSTABLE LOW LEVEL LAPSE RATES...BUT THERE IS NO SATURATION
NOTED WITHIN THE DENDRITIC GROWTH ZONE. SO DESPITE SEEING
EXTENSIVE CLOUD COVER...DOUBTING WHETHER THERE WILL BE MUCH OF ANY
ACTIVITY BEHIND THE COLD FRONT...WHICH AT 1030AM WAS JUST
BEGINNING TO PUSH INTO THE NRN PORTION OF THE MPX MN CWA.
ONLY OTHER CHANGES WERE MINOR TIMING CHANGES TO WIND SPEED
INCREASE AND TEMP/DEWP DROPS BEHIND THE COLD FRONT. WITH MAIN
FRONT COMING IN A LITTLE SLOWER THAN WHAT WAS EXPECTED THIS
MORNING...DELAYED THE SPEED INCREASE AND TEMP DROPS BY A COUPLE OF
HOURS...BUT STILL LOOKING QUITE BLUSTERY WITH AGGRESSIVE TEMP
DROPS ONCE THE FRONT GOES THROUGH...AS SEEN IN FARGO WHERE IT WENT
FROM 36 AT 14Z DOWN TO 18 AT 16Z...SO LOSING NEARLY 10 DEGS PER
HOUR.
PREV DISCUSSION...
/ISSUED 615 AM CST SAT JAN 19 2013/
BIG CHANGE IN THE WEATHER WILL COMMENCE TODAY. LOCAL WRF MODEL
MEAN DOES INDICATE THE NORTHERN CWA WILL SEE SOME SNOW SHOWERS AS
STRONG COLD FRONT DROPS SOUTHEAST OVER THE AREA. APPEARS FRONT
WILL BE LOCATED JUST NORTH OF KMSP THROUGH 18Z. THEN EXITING THE
FAR SOUTH THROUGH 23Z. STRONG NORTHWEST WINDS DEVELOPING BEHIND
FRONT WITH STRONG CAA PATTERN AND STEEP LAPSE RATES DEVELOPING.
THIS ALONG WITH PV ANOMALY SHOULD BE ENOUGH TO DRIVE 45-50 MPH
WIND GUSTS OVER MUCH OF THE AREA INTO THE AFTERNOON WITH FROPA.
WILL CONTINUE THE WIND ADV FOR THE REGION THROUGH 9 PM. TEMPERATURES
EXPECTED TO TUMBLE RAPIDLY AS WELL AFTER FROPA...INTO THE SINGLE
DIGITS NORTHWEST AND THROUGH THE TEENS IN THE SOUTHEAST. WILL NEED
WIND CHILL ADVISORY FOR NORTHERN PORTION OF THE CWA DURING THE NIGHT
AND SATURDAY MORNING.
COLD AIR DROPS OVER THE AREA THE NEXT SEVERAL DAYS AS 1050MB HIGH
MOVES ACROSS THE DAKOTAS WITH MINUS 28 TO MINUS 30 CELSIUS H85 AIR
MOVING ACROSS THE AREA. ANOTHER WEAK SHORT WAVE MOVES ACROSS THE
AREA SUNDAY AND CONTINUED SOME CHANCE POPS...MAINLY TO THE
SOUTHWEST. THE CORE OF COLDEST AIR TO MOVE THROUGH MONDAY WITH
THE ENTIRE CWA EXPECTED TO REMAIN BELOW ZERO. WIND CHILL
WARNING/ADVISORY WILL MOST LIKELY BE NEEDED AGAIN SUNDAY NIGHT
PERHAPS LINGERING THROUGH MONDAY NIGHT OR TUESDAY MORNING.
MODERATION OF THE ARCTIC AIR THEN TAKES PLACE AFTER TUESDAY.
LONGER TERM MODELS SUGGEST ANOTHER MORE SIGNIFICANT WAVE MOVES
INTO THE REGION THURSDAY INTO FRIDAY WITH ANOTHER SHOT AT SOME
ACCUMULATING SNOW. COLDER AIR FOLLOWS THIS SYSTEM AS WELL...BUT
NOT AS COLD AS THE AIR MOVING IN EARLY IN THE PERIOD.
&&
.AVIATION.../18Z TAF ISSUANCE/
SFC LOW NOW MOVING OVER LK SUPERIOR...WITH THE ARCTIC COLD FRONT
NOW STARTING ON A TEAR SOUTH ACROSS MN. WAS INITIALLY THINKING OF
SCALING GUSTS BACK SOME...SINCE GUSTS ACROSS NRN MN/NODAK WERE
ONLY GUSTING IN THE MID 30S...BUT AS OBS AROUND 1730Z STARTED
ROLLING...STARTED TO SEE GUSTS OVER 40 KTS ACROSS WEST CENTRAL MN
RIGHT BEHIND THE BOUNDARY...SO LEFT BIG GUSTS IN PLACE. STILL
EXPECT A 2 OR 3 HOUR WINDOW WITH SUSTAINED WINDS 30-35 KTS WITH
GUSTS 40 TO 45 KTS IMMEDIATELY BEHIND THE FRONT...BEFORE SUSTAINED
SPEEDS AND GUSTS SETTLE DOWN ABOUT 10 KTS. FRONT ALSO COMING DOWN
WITH MVFR CIGS BETWEEN 010 AND 020. THESE CLOUDS WILL REMAIN IN
PLACE THROUGH THE AFTERNOON...BUT CLEARING IS SEEN MOVING SOUTH
ACROSS NODAK THIS AFTERNOON. CURRENTLY CLOCKING THIS CLEARING
MOVING SOUTH AT ABOUT 50 KTS...SO A RETURN TO VFR CONDS MAY COME
ABOUT FASTER THAN CURRENTLY INDICATED. THIS TREND TO VFR CIGS IS
SUPPORTED BY THE SREF...WHICH HAS MUCH OF THE MPX CWA VFR
OVERNIGHT...BEFORE BRINGING ANOTHER ROUND OF MVFR CIGS IN FROM THE
DAKOTAS LATE TONIGHT. AS FOR WX...THERE WILL BE TWO CHANCES FOR
SNOW. FIRST WILL BE BEHIND THE COLD FRONT THIS AFTERNOON...THOUGH
THIS LOOKING LESS LIKELY OUTSIDE OF CENTRAL MN. RAP SOUNDINGS SHOW
POST FRONTAL CLOUD LAYER REACHING UP INTO THE SNOW GROWTH ZONE
NORTH...BUT AS YOU HEAD TOWARD MSP/EAU...THE POST FRONTAL CLOUD
LAYER IS FORECAST TO BE TOO WARM TO GENERATE ICE CRYSTALS...SO CUT
BACK ON SNOW MENTION OUTSIDE OF CENTRAL MN. SECOND CHANCE WILL
COME TONIGHT AS AN UPPER WAVE MOVES ACROSS AN ELEVATED FRONTAL
BOUNDARY ACROSS SW MN. MOST OF THE SNOW LOOKS TO STAY SW OF MPX
TERMINALS...THOUGH RWF LOOKS TO GET A PERIOD OF -SN IN THE
MORNING.
KMSP...MVFR CIGS ALREADY MOVING INTO THE NW METRO AND SHOULD BE IN
AT MSP WITHIN THE FIRST HOUR. WILL START SEEING GUSTS PICK UP WITH
THE ARRIVAL OF THE CLOUDS...THOUGH GUSTS NEAR 40 KTS ARE TRAILING
THE CLOUDS BY A BIT...THOUGH MAY SEE STRONGER GUSTS SHOW UP A BIT
EARLIER THAN 22Z. ALSO PULLED BACK ON SNOW BASED ON WARMER
FORECAST CLOUD LAYER...BUT LOOKING AT IR...IS A NICE BAND OF
COOLER TOPS MOVING SOUTH ACROSS CENTRAL MN AT THE MOMENT. IF THIS
CAN HOLD TOGETHER...MAY NEED TO MENTION AN IFR VIS MENTION IN -SN
BETWEEN 21Z AND 23Z. SREF HAS A GOOD HANDEL ON CLEARING CURRENTLY
MOVING ACROSS NODAK...SO FOLLOWED IT IN BRINGING VFR CONDITION
BACK IN TONIGHT. SNOW MOVING INTO SW MN LOOKS TO REMAIN WELL SW OF
MSP...BUT CAN NOT RULE OUT A FLURRY OR TWO WITH MVFR CONDS MOVING
BACK IN BY SUNDAY AFTERNOON.
/OUTLOOK FOR KMSP/
MON...MVFR CIGS POSSIBLE EARLY. WINDS NW 10 KTS.
TUE...VFR. WINDS W 5 KTS.
WED...VFR. WINDS SW 5 KTS.
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WIND ADVISORY UNTIL 9 PM CST THIS EVENING FOR ANOKA-BENTON-BLUE
EARTH-BROWN-CARVER-CHIPPEWA-CHISAGO-DAKOTA-DOUGLAS-
FARIBAULT-FREEBORN-GOODHUE-HENNEPIN-ISANTI-KANABEC-
KANDIYOHI-LAC QUI PARLE-LE SUEUR-MARTIN-MCLEOD-MEEKER-MILLE
LACS-MORRISON-NICOLLET-POPE-RAMSEY-REDWOOD-RENVILLE-RICE-
SCOTT-SHERBURNE-SIBLEY-STEARNS-STEELE-STEVENS-SWIFT-TODD-
WASECA-WASHINGTON-WATONWAN-WRIGHT-YELLOW MEDICINE.
WIND CHILL ADVISORY FROM 9 PM THIS EVENING TO 11 AM CST SUNDAY
FOR BENTON-DOUGLAS-ISANTI-KANABEC-MILLE LACS-MORRISON-POPE-
SHERBURNE-STEARNS-STEVENS-TODD.
WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 11 AM CST SUNDAY
FOR ANOKA-CHISAGO.
WI...WIND ADVISORY UNTIL 9 PM CST THIS EVENING FOR BARRON-CHIPPEWA-
DUNN-EAU CLAIRE-PEPIN-PIERCE-POLK-RUSK-ST. CROIX.
WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 11 AM CST SUNDAY
FOR BARRON-CHIPPEWA-DUNN-POLK-RUSK-ST. CROIX.
&&
$$
DWE/MPG
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
1100 AM CST SAT JAN 19 2013
.DISCUSSION...
COLD FRONT HAS REACHED ALL BUT THE SOUTHERN VALLEY AND ADJACENT
PORTIONS OF WEST CENTRAL MN WHERE 16 UTC OBSERVATIONS SHOWED
TEMPERATURES STILL IN THE UPPER 20S AND LOW 30S. HIGHS FOR THE DAY
HAVE ALREADY OCCURRED AND WILL SEE FALLING TEMPERATURES THROUGH
THE LATE MORNING AND AFTERNOON HOURS.
REGIONAL RADARS SHOWING WEAK STREAMERS IN WAKE OF THE FRONT...SO
ADDED CHANCE POPS THROUGH THE MID-AFTERNOON FOR POSSIBLY A DUSTING
TO A TENTH OF AN INCH ACCUMULATION. REALISTICALLY...WINDS WILL
MAKE MEASURING ANY NEW SNOWFALL NEARLY IMPOSSIBLE.
STRONGEST WIND SO FAR HAS BEEN CONFINED TO THE HIGHER TERRAIN FROM
ROLLA TO RUGBY TO HARVEY TO COOPERSTOWN WHERE GUSTS AT TIMES HAVE
EXCEEDED 50 MPH. FARTHER SOUTH AND EAST...GUSTS HAVE BEEN IN THE
35 TO 45 MPH RANGE. LATEST RAP STILL SHOWING 925 HPA WINDS AT OR
ABOVE 40 KTS THROUGH THE AFTERNOON...SO AS MIXED LAYER DEEPENS..
STILL EXPECT WINDS TO INCREASE FOR THE NEXT FEW HOURS BEFORE
DECREASING LATER THIS AFTERNOON. SINCE THE EVENT IS STILL
UNFOLDING...WILL NOT MAKE ANY CHANGES TO HIGH WIND WARNING/WIND
ADVISORY HEADLINES AT THIS TIME.
REDUCTIONS IN VISIBILITY AT OR BELOW A QUARTER OF A MILE ARE
WIDESPREAD ACROSS PORTIONS OF THE DEVILS LAKE BASIN AND NORTHERN
VALLEY. THE WORST CONDITIONS WILL CONTINUE ACROSS OPEN COUNTRY
AWAY FROM CITIES AND SHELTERED AREAS. MOST VISIBILITY ISSUES ARE
DUE TO BLOWING AND DRIFTING SNOW ON THE GROUND...BUT CANNOT RULE
OUT RAPID WORSENING CONDITIONS IF A BRIEF SNOW STREAMER MOVES
OVERHEAD. CURRENT BLIZZARD WARNING/WINTER WEATHER ADVISORY LOOKS
GOOD WITH NO CHANGES PLANNED.
&&
.AVIATION...
MVFR CIGS HAVE SLIPPED SOUTH AND EAST AHEAD OF DRY PUNCH...HAVING
REACHED KFAR BY MID MORNING. VENTURI EFFECT HAS SHIFTED VALLEY WINDS
TO A MORE NORTHERLY DIRECTION AT INCREASED SPEEDS...WILL CONTINUE
FOR A TIME BEFORE BACKING TO NORTHWEST FOR THE AFTERNOON. OTHERWISE...
STILL EXPECTING LOWEST VSBY VICINITY OF KDVL LATE MORNING...
AFFECTING NORTHERN VALLEY SITES BY EARLY AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 340 AM CST SAT JAN 19 2013/
DISCUSSION...FORECAST CHALLENGE CONCERNS ONGOING HEADLINES WITH
STRONG ARCTIC COLD FRONT. MODELS IN GOOD AGREEMENT AND WILL USE
BLEND FOR FORECAST.
VERY CHALLENGING FORECAST FOR TODAY AND WILL FOCUS DISCUSSION
MAINLY TO THE VERY SHORT TERM . SURFACE LOW OVER NORTHERN VALLEY TO
PROPAGATE ESE AND DEEPEN BEFORE REACHING THE GREAT LAKES THIS
EVENING. ASSOCIATED STRONG ARCTIC COLD FRONT TO PLOW THROUGH
FORECAST AREA TODAY. MAIN CONCERN WITH FEATURE WILL BE STRONG
WINDS IN WAKE OF COLD FRONTAL PASSAGE AND POTENTIAL FOR BLIZZARD
CONDITIONS AND EVENTUAL HAZARDOUS WIND CHILLS WITH FALLING
TEMPERATURES. WILL SPLIT DISCUSSION TO AREAS RECEIVING PARTICULAR
HEADLINES.
NORTHERN VALLEY INTO DVL BASIN. CURRENT BLIZZARD WARNING LOOKING
GOOD. THIS AREA HAS DEEPEST SNOW COVER AND AVAILABLE FRESH SNOW TO
BLOW AROUND. CURRENT BAND OF -SN ALONG AND NORTH OF SURFACE LOW
SHIFTING INTO FAR NORTHERN MN AND WILL CONTINUE INTO THE MORNING
HOURS. MODEL SOUNDINGS INDICATING MIXED LAYER TO AROUND 900MB WITH
30KTS TO MIX AND SHOULD BE EFFICIENT WITH STRONG COLD ADVECTION.
WHILE GROUND BLIZZARD CONDITIONS NOT EXPECTED WITHIN TOWNS HAVE
EXPANDED BLIZZARD WARNING INTO GRAND FORKS AND WEST POLK COUNTIES
WHERE NORTHERN PARTS OF THE COUNTY AND AREAS WEST OF VALLEY RIDGE
HAVE BETTER POTENTIAL FOR GROUND BLIZZARD CONDITIONS.
REMAINDER OF AREAS WEST OF VALLEY. WINDS ALOFT STRONGER AND MIXED
LAYER DEEPER. LOCAL CHECKLIST INDICATING POTENTIAL FOR STRONGEST
WINDS THIS AREA. TEMPERATURES HAVE BEEN MILD CURRENTLY AND IN THE
PAST WEEK ALONG WITH -RA LAST WEEKEND WHICH HAS CRUSTED SNOW PRETTY
WELL. A FEW SNOW SHOWERS POSSIBLE WITH FROPA HOWEVER SHOULD NOT
GREATLY AFFECT VSBY. WITH POTENTIAL FOR BLOWING SLIM WILL GO WITH
HIGH WIND WARNING.
CENTRAL/SOUTHERN VALLEY INTO ADJACENT PORTIONS OF MN...-RA LAST
WEEKEND AND WARM TEMPERATURES ALSO PUT A HEAVY CRUST ON AVAILABLE
THIN SNOW COVER. WITH LITTLE IN ADDITIONAL SNOW FALL ON TOP OF CRUST
THINK BLSN WILL BE MINIMAL CONFINED TO SOME MINOR RESTRICTION IN
OPEN COUNTRY. SHSN AGAIN ALONG FRONT TO BE ISOLD AND NOT A GREAT
IMPACT ON VSBY. MIXED LAYER ALSO NOT AS DEEP AS WEST OF VALLEY AND
BOTH NAM/GFS MODEL SOUNDING INDICATING ABOUT 30KTS TO MIX WHICH
AGAIN SHOULD BE PRETTY EFFICIENT WITH STRENGTH OF COLD ADVECTION.
WIND DIRECTION MORE NW VS N WHICH WOULD LIMIT FAVORABLE FUNNELING
DOWN VALLEY. FOR THIS DO NOT FEEL WE WILL REACH HIGH WIND CRITERIA.
WITH SOME BLOWING AND EVENTUAL WIND CHILLS WITH FALLING TEMPERATURES
WILL OPT FOR WINTER WX ADVISORY VS JUST WIND ADVISORY TO HEIGHTEN
AWARENESS VS WIND ADVISORY.
FAR SOUTHERN FA HAS BEEN THE WARMEST AND DO BELIEVE THERE WILL
MINIMAL BLOWING SNOW. WITH DELAY IN COLDEST AIR TILL THIS AFTERNOON
WILL JUST GO WITH WIND ADVISORY.
VERY COLD AIRMASS WILL HOLD OVER FA FOR THE REMAINDER OF THE PERIOD.
WILL SE AN EXTENDED PERIOD OF EITHER WIND CHILL ADVISORY/WARNING
HEADLINES REMAINDER OF WEEKEND INTO AT LEAST EARLY NEXT WEEK AS
TEMPERATURES LIKELY TO CLIMB ABOVE ZERO AT ANY TIME.
LONG TERM (TUESDAY-FRIDAY)...
NORTHWEST FLOW ALOFT WILL KEEP TEMPS BELOW NORMAL THROUGH THIS
PERIOD. A BIT OF MODERATION IS POSSIBLE FOR MID-WEEK AS THE UPPER
AIR PATTERN DE-AMPLIFIES WITH WEAKENING OF THE WESTERN NORTH AMERICA
RIDGE. HOWEVER...RECENT MODEL RUNS HAVE TRENDED A BIT COLDER FOR
MID-WEEK WITH MUCH OF THE WARMER AIR REMAINING FARTHER SOUTHWEST.
THE GLOBAL MODELS ALL SUGGEST A PACIFIC SHORTWAVE TROUGH WILL LIFT
ACROSS THE NORTHERN ROCKIES INTO THE NORTHERN PLAINS SOMETIME IN THE
LATE WEDNESDAY THROUGH THURSDAY NIGHT TIME FRAME...WITH THE
GEM/ECMWF QUICKER THAN THE GFS. THIS SYSTEM WILL BRING ANOTHER
CHANCE FOR A BIT OF SNOW TO THE AREA...BUT CONFIDENCE IN THE TIMING
AND PLACEMENT IS LOW...GIVEN THE UNCERTAINTY IN THE EVOLUTION OF THE
UPPER SYSTEM AND ASSOCIATED SFC LOW. BEHIND THE SYSTEM...COLDER
TEMPS ARE EXPECTED ONCE AGAIN AS THE NORTHWEST FLOW AMPLIFIES.
AVIATION...
MVFR/IFR CIGS CONFINED TO FAR NORTHERN AREAS IN AREA OF -SN.
REMAINDER OF FA VFR. EXPECT CIGS TO LOWER THIS AFTERNOON IN WAKE OF
STRONG COLD FRONT. LOWEST VSBY EXPECTED ACROSS DVL BASIN INTO
NORTHERN VALLEY WITH GROUND BLIZZARD CONDITIONS. WINDS WILL INCREASE
SIGNIFICANTLY DURING THE MORNING FROM NW-SE. EXPECT WINDS OF
25-40MPH WITH HIGHER GUSTS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WINTER WEATHER ADVISORY UNTIL 9 PM CST THIS EVENING FOR NDZ030-
039.
WIND ADVISORY UNTIL 9 PM CST THIS EVENING FOR NDZ052-053.
BLIZZARD WARNING UNTIL 9 PM CST THIS EVENING FOR NDZ006>008-
014>016-024-026-027-054.
HIGH WIND WARNING UNTIL 9 PM CST THIS EVENING FOR NDZ028-029-038-
049.
MN...WINTER WEATHER ADVISORY UNTIL 9 PM CST THIS EVENING FOR MNZ002-
003-005-008-013>015-022-027-028.
WIND ADVISORY UNTIL 9 PM CST THIS EVENING FOR MNZ029>032-040.
BLIZZARD WARNING UNTIL 9 PM CST THIS EVENING FOR MNZ001-004-007.
&&
$$
ROGERS/VOELKER/WJB
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
443 PM CST SAT JAN 19 2013
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND SUNDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A STRONG
SHORTWAVE DIVING SE OVER NORTHERN MINNESOTA...WHICH IS DRIVING A
SURFACE LOW OVER WESTERN LAKE SUPERIOR. ARCTIC COLD FRONT EXTENDS
WESTWARD FROM THIS LOW OVER CENTRAL MINNESOTA AND NORTHERN SOUTH
DAKOTA. RETURNS ON RADAR OVER WESTERN WISCONSIN MAY NOT BE HITTING
THE GROUND...BUT THERE IS SCATTERED SNOW SHOWERS OCCURRING ALONG THE
ARCTIC FRONT AND JUST AHEAD OF THE SHORTWAVE...WHICH ARE DROPPING
VISIBILITIES TO AROUND A MILE AT TIMES. WINDS ARE ALSO RAPIDLY
INCREASING BEHIND THE FRONT...WITH SOME WIDELY SCATTERED REPORTS
JUST HIGHER THAN 40 KTS. TEMPERATURES BEHIND THE FRONT ARE FALLING
QUICKLY INTO THE SINGLE DIGITS ABOVE ZERO...WHILE READINGS ARE IN
THE UPPER 30S TO LOWER 40S ACROSS NORTHERN WISCONSIN. WITH THE
PASSAGE OF THE ARCTIC FRONT THIS EVENING...TEMPERATURE AND WIND
HEADLINES ARE THE MAIN FORECAST CONCERNS.
TONIGHT...THE STRONG SHORTWAVE WILL PUSH THE ARCTIC COLD FRONT
RAPIDLY SOUTHEAST ACROSS NORTH-CENTRAL WISCONSIN LATER THIS
AFTERNOON...AND NORTHEAST WISCONSIN EARLY THIS EVENING. DESPITE
STRONG MID AND UPPER LEVEL FORCING IN THE FORM OF -DIVQ AND
DIVERGENCE AHEAD OF THE WAVE...MID-LEVELS STRUGGLE TO SATURATE. SO
THINK WILL SEE NOT MUCH MORE THAN A SCT LINE OF SNOW SHOWERS JUST
AHEAD OF THE SHORTWAVE...WHICH WILL PROVIDE A BRIEF BURST OF SNOW
AND REDUCE VISIBILITIES...BUT NOT MUCH IN THE WAY OF ACCUMS. SO
WILL KEEP POPS IN THE LOW CHANCE RANGE OVER NE WISCONSIN FOR EARLY
THIS EVENING WITH THE FRONTAL PASSAGE. CLOUDS EXTEND NORTH ACROSS
MINNESOTA TO THE CANADIAN BORDER WHERE SNOW SHOWERS CONTINUE TO FALL
UNDER A LOW OVERCAST. SO THINK SNOW SHOWERS WILL FALL OVER
NORTH-CENTRAL WISCONSIN FOR MUCH OF THE EVENING. BEHIND THE FRONT
BY LATE IN THE EVENING...LOW LEVEL WINDS WILL SHIFT TO THE NORTHWEST
WITH GOOD TRAJECTORIES FOR LAKE EFFECT SNOW ACCUMULATIONS.
HOWEVER...850MB TEMPS WILL BE PLUMMETING INTO THE LOWER 20S BELOW
ZERO WHICH IS GETTING TOO COLD FOR GOOD DENDRITIC SNOW GROWTH. AS A
RESULT...FLAKES WILL BE SMALL AND ACCUMS SHOULD BE HELD IN
CHECK...AND WILL CONTINUE TO GO WITH 1-3 INCH AMOUNTS TONIGHT IN THE
SNOW BELT OF N-C WISCONSIN. LITTLE TO NO ACCUM ELSEWHERE.
BIGGER IMPACTS WILL LIKELY BE WIND RELATED. STRONG DESCENT
IMMEDIATELY BEHIND THE FRONT IN A REGION OF STRONG COLD
ADVECTION...STEEPENING LOW LEVEL LAPSE RATES...AND GOOD ISALLABARIC
PUSH WILL CREATE STRONG GUSTY WEST TO NORTHWEST WINDS THAT SHOULD
APPROACH OR JUST EXCEED WIND ADVISORY CRITERIA LATE THIS AFTERNOON
AND THROUGH THE EVENING. STRONGEST WINDS IN THE MIXED LAYER OF
45-50KTS ARE PROGGED TO OCCUR OVER CENTRAL AND EAST-CENTRAL
WISCONSIN WHERE THE CURRENT WIND ADVISORY RESIDES...SO PLACEMENT OF
HEADLINES LOOK GOOD. THE GUSTY WINDS SEEM TO BE RUNNING AN HOUR OR
TWO LATE...AND WILL LIKELY HAVE TO WAIT UNTIL THE COLDER AIR ALOFT
ARRIVES TO STEEPEN THE LOW LEVEL LAPSE RATES FOR THE GUSTY WINDS TO
OCCUR...LIKELY IN THE 22-02Z TIME PERIOD. WILL KEEP HEADLINE TIMING
STATUS QUO. THE STRONG PRESSURE RISES SHIFT TO THE EAST BY
MIDNIGHT...AND WIND GUSTS SHOULD BE SUBSIDING BY THIS TIME. AS A
RESULT...STILL THINK THE EVENING OR MIDNIGHT CREW WILL BE ABLE TO
END WIND HEADLINES EARLY. THE COMBO OF GUSTY NW WINDS AND INCOMING
ARCTIC AIR WILL CREATE WIND CHILL READINGS OF 20-25 DEGREES BELOW
ZERO OVER CENTRAL AND NORTH-CENTRAL WISCONSIN LATE TONIGHT.
SUNDAY...ARCTIC AIR WILL CONTINUE TO POUR ACROSS THE REGION ON
SUNDAY. NORTHWEST WINDS WILL CONTINUE TO PRODUCE LAKE EFFECT SNOW
SHOWERS IN THE SNOW BELTS...BUT WINDS DO BACK A BIT SO SNOW SHOWERS
SHOULD BE GRADUALLY DIMINISHING OVER THE COURSE OF THE MORNING. AIR
WILL REMAIN TOO COLD FOR DENDRITIC SNOW GROWTH SO NOT EXPECTING MUCH
ACCUMS. OTHERWISE...STEEP LOW LEVEL LAPSE RATES AND FLOW OFF LAKE
SUPERIOR SHOULD KEEP SKIES PARTLY TO MOSTLY CLOUDY. TEMPS IN THE
SINGLE DIGITS TO LOWER TEENS.
.LONG TERM...SUNDAY NIGHT THROUGH NEXT SATURDAY. DURATION OF THE
ARCTIC BLAST OF AIR THIS WEEK ALONG WITH LIKELY ADDITIONAL WIND
CHILL HEADLINES WILL BE THE PRIMARY ISSUE FOR THE FIRST HALF OF
THE NEW WEEK. ANOTHER CLIPPER SYSTEM IS PROGGED TO DROP INTO THE
REGION AROUND THURSDAY FOLLOWED WITH A REINFORCING BUT MILDER
AND PERHAPS BRIEFER SHOT OF ARCTIC AIR. SOME MDM RANGE MODELS ARE
INDICATING A MODERATING TREND LATER NEXT WEEKEND.
ADDITIONAL WIND CHILL HEADLINES WILL LIKELY BE POSTED LATER THIS
WEEKEND AS THE SATURDAY NIGHT HEADLINES EXPIRE. FORECAST TEMPS
SUGGEST THE COLDEST AIR ARRIVES LATER MONDAY WITH SOME CURRENT
VALUES APPROACHING WIND CHILL WARNING CRITERIA MONDAY NIGHT.
TYPICAL WITH THE VERY COLD PATTERNS...MODELS LIKELY OVERDOING THE
COVERAGE OF CLOUDS. WILL TONE DOWN CLOUDS OVER MOST LOCATIONS
EXCEPT FOR AREAS JUST DOWNSTREAM FROM LAKE SUPERIOR.
LAKE EFFECT SNOWS EXPECTED OVER FAR NORTH CENTRAL WISCONSIN WITH
THE COLD AIR INTRUSION. BUT APPEARS TO BE LIMITED AT THIS TIME
DUE TO THE DRY AIR MASS...FALLING INVERSION HEIGHTS...AND A BIT
TOO WESTERLY WIND DIRECTION.
TEMPS TO MODERATE TO NEAR SEASONAL LEVELS LATER THIS WEEK WITH A
CLIPPER SYSTEM DROPPING SOUTH INTO THE NORTHERN AND CENTRAL PLAINS
THURSDAY BEFORE PHASING WITH SOME SOUTHERN STREAM ENERGY THURSDAY
NIGHT. GFS IS INDICATING A POSSIBLE ADVISORY SNOW OVER THE SOUTH
HALF OR THIRD OF THE STATE THURSDAY NIGHT WITH THIS PHASED SYSTEM.
WILL GLANCE AT THE ECMWF THIS AFTERNOON TOO SEE IF A SIMILAR
TREND IN ORDER TO MAKE ANY ADJUSTMENTS...BUT GOING FORECAST THAT
FAR OUT REASONABLE.
&&
.AVIATION...FOR 00Z TAF ISSUANCE. ARCTIC FRONT SURGING SE ACRS THE
AREA. WL SEE A PERIOD OF STG WINDS AND SOME MVFR CIGS AND VSBYS
THIS EVENING. BRIEF IFR CONDITONS POSSIBLE. NOT REALLY THAT MUCH
SNOW TO BLOW ARND IN THE AREA...SO EXPECT CONDITIONS TO IMPROVE
BACK TO VFR BY LATE TNGT. THE EXCEPTION MAY BE IN THE FAR N /RHI/
WHERE CLDS OFF LAKE SUPERIOR WL CONT TO STREAM SE.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 3 AM CST SUNDAY FOR WIZ038>040-048>050.
WIND ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR WIZ030-031-035>037-
045.
WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM CST SUNDAY FOR
WIZ005-010-011-018-019-030-035-036.
WIND ADVISORY UNTIL 6 AM CST SUNDAY FOR WIZ022.
&&
$$
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
315 PM CST SAT JAN 19 2013
.SHORT TERM...
TONIGHT - CONFIDENCE...MEDIUM
STRENGTHENING LOW PRESSURE CONTINUES TO SHIFT EAST FROM NEAR LAKE
SUPERIOR. NICE POCKET OF PRESSURE DRIVING SOUTHEAST FROM THE
DAKOTAS. THE RUC IS BEHIND SCHEDULE A BIT ON THIS...BUT HAS A A
PRESSURE RISE MAX OVER THE CWA AT 6Z...BUT MAY END UP BEING MORE
AROUND 3Z. LEADING EDGE OF ARCTIC FRONT DRIVING SE FROM CENTRAL MN.
FRONT EXPECTED TO CLEAR THE SOUTHEAST BY 3Z. BUFKIT SOUNDINGS SHOW
FAIRLY DEEP POST-FRONTAL MIXING AND STRONG SUBSIDENCE FROM LATER
THIS EVENING INTO THE OVERNIGHT WITH WIND ADVISORY CRITERIA STILL
LIKELY. IN FACT RAP SOUNDINGS VERY IMPRESSIVE ACTUALLY SHOWING
BORDERLINE WARNING FOR A TIME. RUC PROGGED 3 HOUR PRESSURE RISE OF
4-5 MB SLIDING ACROSS LATER COMBINED WITH 50 KNOT 850 WIND MAX
SUGGESTS THIS IDEA. AT THIS POINT WE ARE LOOKING AT A HIGH END
ADVISORY/LOW END WARNING. WILL RETAIN THE ADVISORY AT THIS POINT BUT
WOULD NOT BE SURPRISED TO SEE A FEW GUSTS EXCEED THE WARNING
THRESHOLD.
GUIDANCE NUMBERS STILL SUPPORT SINGLE DIGIT LOWS FOR MUCH OF CWA.
PREFER THE DRIER LOOK THE NAM/HPC VERSUS GFS/ECMWF WITH RESPECT TO
QPF IN THE COLD ADVECTION REGIME. STRATUS POTENTIAL THERE GIVEN
MODEL AGREEMENT IN LOW LEVEL RH PROGS. WILL NOT MENTION FLURRIES
AT THIS TIME WITH VERY LITTLE REPORTS UPSTREAM THOUGH FLOW WILL BE
CYCLONIC BUT LOW LEVELS TO BECOME DOMINATED BY SUBSIDENCE. GIVEN
THE SLOWER ARRIVAL OF THE FRONT...PUSHED EASTERN WIND ADVISORY
AHEAD AN HOUR. KEPT THE WEST AS IS TO BLEND WITH NEIGHBORS.
SUNDAY - CONFIDENCE...MEDIUM
ARCTIC AIR-MASS IN PLACE. 925 TEMPS AVERAGING -14 TO -17C SUGGEST
TEMPS MODIFYING INTO THE TEENS WHICH SEEMS REASONABLE WITH ABSENCE OF
SNOW-COVER. ELONGATED SHORTWAVE DROPS ACROSS THE AREA. NOT OVERLY
IMPRESSED WITH THIS FEATURE. QPF PROGS TREND THIS FURTHER WEST OR
SOUTHWEST OF THE CWA. FOCUS APPEARS WEST CLOSER TO MAX IN 850-700
MILLIBAR Q-VECTOR CONVERGENCE. MOISTURE LOOKS LIMITED. ADDED SOME
FLURRIES IN THE SOUTHWEST IN THE AFTERNOON TO MATCH UP WITH KDVN AND
KARX...BUT EVEN NEW 12Z ECMWF HAS TRENDED FURTHER SOUTHWEST THIS
FEATURE.
.LONG TERM...
.SUNDAY NIGHT THROUGH TUESDAY NIGHT...FORECAST CONFIDENCE IS MEDIUM.
AN IMPULSE/VORTICITY MAX PROGGED BY MODELS TO SLIDE SOUTHEAST FROM
DAKOTAS TO ILLINOIS SUNDAY NIGHT. HOWEVER...MOSTLY CHANNELED
VORTICITY WITH THIS FEATURE. MODEL SOUNDINGS SUNDAY EVENING SUGGEST
SOME FLURRIES AT BEST....WILL BLEND IN WITH NEIGHBORS ON THE
FLURRIES SUNDAY EVENING.
BASIC COLD DRY NORTHWEST FLOW ALOFT MONDAY INTO TUESDAY NIGHT. CORE
OF COLDEST AIR AT 850 MB WILL ARRIVE IN WISCONSIN ON MONDAY WITH
-24C TO -26...SETTING UP THE COLDEST NIGHT OF THE WINTER SEASON FOR
MONDAY NIGHT INTO EARLY TUESDAY MORNING. PROGGED WIND CHILL VALUES
OF -20C TO -25C FOR MONDAY NIGHT UNTIL ABOUT 10 OR 11 AM CST TUESDAY
FOR SOUTHERN WISCONSIN WILL REQUIRE A WIND CHILL ADVISORY TO BE
ISSUED ON LATER SHIFTS. THIS ASSUMES FORECAST PANS OUT.
.WEDNESDAY AND WEDNESDAY NIGHT...FORECAST CONFIDENCE IS MEDIUM.
SURFACE RIDGE WILL EXTEND FROM DAKOTAS TO THE TENNESSEE AREA...SO
QUIET AT THIS TIME. BOTH GFS AND ECMWF MODERATE 850 MB TEMPERATURES
TO -18C TO -20C BY 6 AM WED...SO SOMEWHAT WARMER SURFACE TEMPS
EXPECTED ON WEDNESDAY. HOWEVER...ECMWF BRINGS ANOTHER PUSH OF COLD
AIR DOWN INTO SOUTHERN WISCONSIN WEDNESDAY AFTERNOON. IN ANY
CASE...BOTH MODELS CONTINUE MODERATION TREND LATE WEDNESDAY NIGHT.
.THURSDAY AND FRIDAY...FORECAST CONFIDENCE IS LOW.
ON THURSDAY...MODELS SHOW ANOTHER SHORT-WAVE TROUGH DROPPING EAST
SOUTHEAST THROUGH THE WISCONSIN AREA. ASSOCIATED WARM-AIR ADVECTION
AND ISENTROPIC LIFT IN MID-LEVELS QUICKLY RESULTS IN CLOUDY SKIES
AND CHANCES OF SNOW BY LATE AFTERNOON...CONTINUING INTO THURSDAY
NIGHT. A SECONDARY SHORT-WAVE TROUGH ROTATES SOUTH OUT OF WESTERN
ONTARIO CANADA ON FRIDAY INTO GREAT LAKES REGION. THIS WILL CONTINUE
THE CHANCES OF SOME LIGHT SNOW INTO FRIDAY. MEANWHILE...SURFACE LOW
PRESSURE WILL MOVE NORTHEAST TO SOUTHERN OHIO BY FRIDAY MORNING PER
GFS...AND IN KENTUCKY PER ECMWF. 12Z GFS RUN THIS MORNING HAS THIS
LOW PRESSURE DEEPER THAN ECMWF...A FLIP-FLOP FROM 00Z RUN FRIDAY
EVENING WHICH HAD ECMWF WITH THE DEEPER SOLUTION. STAY TUNED.
&&
.AVIATION/00Z TAFS/...MAIN CONCERN WILL BE THE STRONG POST-FRONTAL
WINDS THAT ARRIVE VERY LATE THIS AFTERNOON/MORE LIKELY THIS EVENING
ACROSS SRN WI. NW WINDS OF 25-35 KNOTS LOOK LIKE A GOOD BET WITH
SOME GUSTS OVER 40 KNOTS. LOW LEVEL RH PROGS SUGGEST A GLANCING SHOT
OF STRATUS IN THE 6-12Z TIME FRAME TONIGHT IN THE COLD ADVECTION
REGIME...WITH A DRIER SIGNAL IN THE 12Z-00Z TIME FRAME ON SUNDAY.
GRADIENT SLACKENS FOR SUNDAY. WEAK VORT AXIS SLIDES THROUGH THOUGH
MOISTURE/LIFT LACKING. A FEW FLURRIES IN PARTS OF SC WI THOUGH ALL
MODELS KEEP QPF FURTHER SOUTHWEST OF THE AREA.
&&
.MARINE...NO CHANGES TO HEADLINES AT THIS POINT. HEAVY FREEZING
SPRAY AND GALE CONDITIONS LOOK VERY FAVORABLE TONIGHT AS STRONG COLD
FRONT PUSHES THROUGH THIS EVENING. ONCE GALE EXPIRES...SMALL CRAFT
WILL LIKELY BE NEEDED.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...WIND ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR WIZ046-047-056-057-
062-063-067-068.
WIND ADVISORY UNTIL 3 AM CST SUNDAY FOR WIZ051-052-058>060-
064>066-069>072.
LM...HEAVY FREEZING SPRAY WARNING FROM MIDNIGHT TONIGHT TO NOON CST
SUNDAY FOR LMZ643>646.
SMALL CRAFT ADVISORY UNTIL 6 PM CST THIS EVENING FOR LMZ643>646.
GALE WARNING UNTIL 6 AM CST SUNDAY FOR LMZ643>646.
&&
$$
TONIGHT/SUNDAY AND AVIATION/MARINE...COLLAR
SUNDAY NIGHT THROUGH SATURDAY...KAPELA
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
218 PM CST SAT JAN 19 2013
.SHORT TERM...TONIGHT AND SUNDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A STRONG
SHORTWAVE DIVING SE OVER NORTHERN MINNESOTA...WHICH IS DRIVING A
SURFACE LOW OVER WESTERN LAKE SUPERIOR. ARCTIC COLD FRONT EXTENDS
WESTWARD FROM THIS LOW OVER CENTRAL MINNESOTA AND NORTHERN SOUTH
DAKOTA. RETURNS ON RADAR OVER WESTERN WISCONSIN MAY NOT BE HITTING
THE GROUND...BUT THERE IS SCATTERED SNOW SHOWERS OCCURRING ALONG THE
ARCTIC FRONT AND JUST AHEAD OF THE SHORTWAVE...WHICH ARE DROPPING
VISIBILITIES TO AROUND A MILE AT TIMES. WINDS ARE ALSO RAPIDLY
INCREASING BEHIND THE FRONT...WITH SOME WIDELY SCATTERED REPORTS
JUST HIGHER THAN 40 KTS. TEMPERATURES BEHIND THE FRONT ARE FALLING
QUICKLY INTO THE SINGLE DIGITS ABOVE ZERO...WHILE READINGS ARE IN
THE UPPER 30S TO LOWER 40S ACROSS NORTHERN WISCONSIN. WITH THE
PASSAGE OF THE ARCTIC FRONT THIS EVENING...TEMPERATURE AND WIND
HEADLINES ARE THE MAIN FORECAST CONCERNS.
TONIGHT...THE STRONG SHORTWAVE WILL PUSH THE ARCTIC COLD FRONT
RAPIDLY SOUTHEAST ACROSS NORTH-CENTRAL WISCONSIN LATER THIS
AFTERNOON...AND NORTHEAST WISCONSIN EARLY THIS EVENING. DESPITE
STRONG MID AND UPPER LEVEL FORCING IN THE FORM OF -DIVQ AND
DIVERGENCE AHEAD OF THE WAVE...MID-LEVELS STRUGGLE TO SATURATE. SO
THINK WILL SEE NOT MUCH MORE THAN A SCT LINE OF SNOW SHOWERS JUST
AHEAD OF THE SHORTWAVE...WHICH WILL PROVIDE A BRIEF BURST OF SNOW
AND REDUCE VISIBILITIES...BUT NOT MUCH IN THE WAY OF ACCUMS. SO
WILL KEEP POPS IN THE LOW CHANCE RANGE OVER NE WISCONSIN FOR EARLY
THIS EVENING WITH THE FRONTAL PASSAGE. CLOUDS EXTEND NORTH ACROSS
MINNESOTA TO THE CANADIAN BORDER WHERE SNOW SHOWERS CONTINUE TO FALL
UNDER A LOW OVERCAST. SO THINK SNOW SHOWERS WILL FALL OVER
NORTH-CENTRAL WISCONSIN FOR MUCH OF THE EVENING. BEHIND THE FRONT
BY LATE IN THE EVENING...LOW LEVEL WINDS WILL SHIFT TO THE NORTHWEST
WITH GOOD TRAJECTORIES FOR LAKE EFFECT SNOW ACCUMULATIONS.
HOWEVER...850MB TEMPS WILL BE PLUMMETING INTO THE LOWER 20S BELOW
ZERO WHICH IS GETTING TOO COLD FOR GOOD DENDRITIC SNOW GROWTH. AS A
RESULT...FLAKES WILL BE SMALL AND ACCUMS SHOULD BE HELD IN
CHECK...AND WILL CONTINUE TO GO WITH 1-3 INCH AMOUNTS TONIGHT IN THE
SNOW BELT OF N-C WISCONSIN. LITTLE TO NO ACCUM ELSEWHERE.
BIGGER IMPACTS WILL LIKELY BE WIND RELATED. STRONG DESCENT
IMMEDIATELY BEHIND THE FRONT IN A REGION OF STRONG COLD
ADVECTION...STEEPENING LOW LEVEL LAPSE RATES...AND GOOD ISALLABARIC
PUSH WILL CREATE STRONG GUSTY WEST TO NORTHWEST WINDS THAT SHOULD
APPROACH OR JUST EXCEED WIND ADVISORY CRITERIA LATE THIS AFTERNOON
AND THROUGH THE EVENING. STRONGEST WINDS IN THE MIXED LAYER OF
45-50KTS ARE PROGGED TO OCCUR OVER CENTRAL AND EAST-CENTRAL
WISCONSIN WHERE THE CURRENT WIND ADVISORY RESIDES...SO PLACEMENT OF
HEADLINES LOOK GOOD. THE GUSTY WINDS SEEM TO BE RUNNING AN HOUR OR
TWO LATE...AND WILL LIKELY HAVE TO WAIT UNTIL THE COLDER AIR ALOFT
ARRIVES TO STEEPEN THE LOW LEVEL LAPSE RATES FOR THE GUSTY WINDS TO
OCCUR...LIKELY IN THE 22-02Z TIME PERIOD. WILL KEEP HEADLINE TIMING
STATUS QUO. THE STRONG PRESSURE RISES SHIFT TO THE EAST BY
MIDNIGHT...AND WIND GUSTS SHOULD BE SUBSIDING BY THIS TIME. AS A
RESULT...STILL THINK THE EVENING OR MIDNIGHT CREW WILL BE ABLE TO
END WIND HEADLINES EARLY. THE COMBO OF GUSTY NW WINDS AND INCOMING
ARCTIC AIR WILL CREATE WIND CHILL READINGS OF 20-25 DEGREES BELOW
ZERO OVER CENTRAL AND NORTH-CENTRAL WISCONSIN LATE TONIGHT.
SUNDAY...ARCTIC AIR WILL CONTINUE TO POUR ACROSS THE REGION ON
SUNDAY. NORTHWEST WINDS WILL CONTINUE TO PRODUCE LAKE EFFECT SNOW
SHOWERS IN THE SNOW BELTS...BUT WINDS DO BACK A BIT SO SNOW SHOWERS
SHOULD BE GRADUALLY DIMINISHING OVER THE COURSE OF THE MORNING. AIR
WILL REMAIN TOO COLD FOR DENDRITIC SNOW GROWTH SO NOT EXPECTING MUCH
ACCUMS. OTHERWISE...STEEP LOW LEVEL LAPSE RATES AND FLOW OFF LAKE
SUPERIOR SHOULD KEEP SKIES PARTLY TO MOSTLY CLOUDY. TEMPS IN THE
SINGLE DIGITS TO LOWER TEENS.
.LONG TERM...SUNDAY NIGHT THROUGH NEXT SATURDAY. DURATION OF THE
ARCTIC BLAST OF AIR THIS WEEK ALONG WITH LIKELY ADDITIONAL WIND
CHILL HEADLINES WILL BE THE PRIMARY ISSUE FOR THE FIRST HALF OF
THE NEW WEEK. ANOTHER CLIPPER SYSTEM IS PROGGED TO DROP INTO THE
REGION AROUND THURSDAY FOLLOWED WITH A REINFORCING BUT MILDER
AND PERHAPS BRIEFER SHOT OF ARCTIC AIR. SOME MDM RANGE MODELS ARE
INDICATING A MODERATING TREND LATER NEXT WEEKEND.
ADDITIONAL WIND CHILL HEADLINES WILL LIKELY BE POSTED LATER THIS
WEEKEND AS THE SATURDAY NIGHT HEADLINES EXPIRE. FORECAST TEMPS
SUGGEST THE COLDEST AIR ARRIVES LATER MONDAY WITH SOME CURRENT
VALUES APPROACHING WIND CHILL WARNING CRITERIA MONDAY NIGHT.
TYPICAL WITH THE VERY COLD PATTERNS...MODELS LIKELY OVERDOING THE
COVERAGE OF CLOUDS. WILL TONE DOWN CLOUDS OVER MOST LOCATIONS
EXCEPT FOR AREAS JUST DOWNSTREAM FROM LAKE SUPERIOR.
LAKE EFFECT SNOWS EXPECTED OVER FAR NORTH CENTRAL WISCONSIN WITH
THE COLD AIR INTRUSION. BUT APPEARS TO BE LIMITED AT THIS TIME
DUE TO THE DRY AIR MASS...FALLING INVERSION HEIGHTS...AND A BIT
TOO WESTERLY WIND DIRECTION.
TEMPS TO MODERATE TO NEAR SEASONAL LEVELS LATER THIS WEEK WITH A
CLIPPER SYSTEM DROPPING SOUTH INTO THE NORTHERN AND CENTRAL PLAINS
THURSDAY BEFORE PHASING WITH SOME SOUTHERN STREAM ENERGY THURSDAY
NIGHT. GFS IS INDICATING A POSSIBLE ADVISORY SNOW OVER THE SOUTH
HALF OR THIRD OF THE STATE THURSDAY NIGHT WITH THIS PHASED SYSTEM.
WILL GLANCE AT THE ECMWF THIS AFTERNOON TOO SEE IF A SIMILAR
TREND IN ORDER TO MAKE ANY ADJUSTMENTS...BUT GOING FORECAST THAT
FAR OUT REASONABLE.
&&
.AVIATION...WHILE LIGHT MIXED PRECIPITATION HAS EXITED NORTHEAST
WISCONSIN...THE BIGGEST AVIATION HAZARDS WILL ACCOMPANY AN ARCTIC
COLD FRONTAL PASSAGE LATE THIS AFTERNOON AND THIS EVENING. SCT SNOW
SHOWERS ARE STILL EXPECTED TO DEVELOP ALONG THE FRONT...WITH LOCAL
VSBYS BLO 1SM. IN ADDITION...STRONG WEST WINDS WILL DEVELOP BEHIND
THE FRONT AS ARCTIC AIR POURS ACROSS THE STATE...WITH GUSTS TO 35 TO
40 KTS...HIGHEST ACROSS C/EC WI AND ALONG THE LAKESHORE. LAKE EFFECT
SNOW SHOWERS WILL DEVELOP IN NC WI TONIGHT...AND NW WINDS WILL BE
STRONG ENOUGH TO CARRY SOME SNOW INTO RHI. IMPROVING CONDITIONS
WILL OCCUR AFTER MIDNIGHT IN TERMS OF DIMINISHING WINDS...SNOW
SHOWERS...AND INCREASING CIGS. VFR CONDITIONS TOMORROW UNDER ARCTIC
HIGH PRESSURE.
MPC
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 6 PM THIS EVENING TO 3 AM CST SUNDAY FOR
WIZ038>040-048>050.
WIND ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR WIZ030-031-035>037-
045.
WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM CST SUNDAY FOR
WIZ005-010-011-018-019-030-035-036.
WIND ADVISORY FROM 6 PM THIS EVENING TO 6 AM CST SUNDAY FOR
WIZ022.
&&
$$
MPC/TDH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1135 AM CST SAT JAN 19 2013
.SHORT TERM...TODAY THROUGH MONDAY NIGHT
947 AM CST SAT JAN 19 2013
947 AM UPDATE...FORECAST IN GENERAL REMAINS ON TRACK. POTENT
SHORTWAVE WAS NOTED ON THE 15Z WATER VAPOR LOOP OVER SOUTHERN
MANITOBA...WITH A 120-140 KT JET AT THE TROPOPAUSE DIGGING INTO
THE DAKOTAS ON THE SOUTHWEST SIDE OF THE SHORTWAVE PER RAP
ANALYSIS. DPVA AHEAD OF THE SHORTWAVE HAS RESULTED IN A DEEPENING
SURFACE LOW...CURRENTLY AROUND 1002MB CENTERED OVER THE MN
ARROWHEAD. TRAILING THE LOW IS AN ARCTIC COLD FRONT ALONG THE
NORTH DAKOTA/SOUTH DAKOTA BORDER. SURFACE TEMPERATURES DROP FROM
THE MID TO UPPER 30S FROM SOUTH DAKOTA INTO THE FORECAST
AREA...INTO THE SINGLE DIGITS ABOVE ZERO OVER NORTHERN NORTH
DAKOTA. WITH THE RAPID DROP IN TEMPERATURES IS A 2 MB/HR PRESSURE
RISE OVER NORTH DAKOTA. THESE PRESSURE RISES AND A TIGHT PRESSURE
GRADIENT BEHIND THE ARCTIC FRONT HAS RESULTED IN WINDS GUSTING
30-50 KT ACROSS NORTH DAKOTA INTO FAR NORTHWEST MN. THERE ARE ALSO
SOME SNOW SHOWERS OCCURRING IMMEDIATELY BEHIND THE FRONT...AIDED
BY LOW LEVEL FRONTOGENESIS.
NAM/RAP/HRRR FORECASTS CONTINUE TO INDICATE THAT THE ARCTIC FRONT
WILL CROSS THE FORECAST AREA BETWEEN 21-00Z...WITH WINDS AND GUSTS
RAPIDLY INCREASING BEHIND THE FRONT AS INDICATED OVER NORTH
DAKOTA. INTERESTING TO SEE THAT AT 00Z...THE RAP WIND GUSTS SHOW
UPWARDS OF 40 KT OR SO ACROSS THE ENTIRE FORECAST AREA. NEEDLESS
TO SAY...THE WIND ADVISORY LOOKS SOLID. PLUS...THE SURFACE LOW
SHOULD BE ABLE TO DEEPEN A LITTLE MORE AS IT MOVES ACROSS THE
WARMER LAKE SUPERIOR WATER...AND HAS THE SYNOPTIC SCALE IMPACT TO
DEEPEN.
THERE ARE 2 ISSUES PRIOR TO THE ARCTIC FRONT ARRIVAL...THOUGH. THE
FIRST IS CLOUD COVER. FIRST BAND OF MID CLOUDS...ASSOCIATED WITH A
SHORTWAVE SEEN ON WATER VAPOR STRETCHING FROM NORTHEAST NEBRASKA
TO LA CROSSE...IS CLEARING OUT OF THE FORECAST AREA RIGHT NOW.
ANOTHER BATCH OF MID CLOUDS HAVE DEVELOPED OVER CENTRAL MN...AHEAD
OF ANOTHER WEAK SHORTWAVE. THESE CLOUDS APPEAR SLATED TO CROSS THE
FORECAST AREA DURING THE NEXT FEW HOURS. HAVE INCREASED CLOUD
COVER TO ACCOUNT FOR THESE. THERE STILL MAY BE ANOTHER BREAK IN
CLOUDS BEFORE THE ARCTIC FRONT ARRIVES. WITH THE IN-AND-OUT
PERIODS OF SUNSHINE AND 925MB TEMPS AROUND 5C PER 12Z MPX AND DVN
RAOBS...CONCERNED TEMPERATURES ARE NOT HIGH ENOUGH. HRRR ACTUALLY
HAS TEMPERATURES CLIMBING INTO THE LOW 50S OVER THE SOUTHERN HALF
OF THE FORECAST AREA. HRRR DID VERY WELL YESTERDAY...ALBEIT WE DID
HAVE FULL SUNSHINE. FOR NOW HAVE INCREASED TEMPERATURES
SLIGHTLY...MAINLY SOUTH OF I-90.
LASTLY...RAP AND 00Z/06Z NCEP HIRES ARW RUNS ARE IN GOOD AGREEMENT
SHOWING THE BAND OF SNOW SHOWERS OVER SOUTHERN NORTH DAKOTA POST-
FRONTAL DROPPING THROUGH MOST OF THE FORECAST AREA BETWEEN 18-00Z.
PREVIOUS FORECAST HAD THIS COVERED WELL...JUST GAVE A LITTLE MORE
TIMING AND SWITCHED TO A COVERAGE SNOW SHOWERS PHRASING SINCE
THERE IS A CONVECTIVE NATURE TO THE PRECIPITATION.
PREVIOUS DISCUSSION ISSUED AT 318 AM...
THE MAIN FOCUS IS ON THE DRASTIC CHANGES THAT ARE ON TAP FOR TODAY
AS A COLD FRONT DROPS THROUGH THE REGION.
CURRENTLY...BROAD CYCLONIC FLOW ALOFT IS IN PLACE THROUGH MUCH OF
CANADA AND THE US WITH THE CORE OF THE LOW CENTERED TO THE EAST OF
HUDSON BAY LEAVING THE UPPER MISSISSIPPI RIVER VALLEY IN
NORTHWESTERLY FLOW. DESPITE THIS...LOW LEVEL TEMPERATURES REMAIN
MILD AT THE MOMENT WITH A SURFACE LOW OVER EASTERN NORTH DAKOTA
AND A WARM FRONT EXTENDING TO THE EAST-SOUTHEAST ACROSS NORTHERN
WISCONSIN. THIS MORNING WILL END UP BEING THE WARMEST PART OF THE
DAY AS THIS SURFACE LOW TRACKS TO THE EAST TOWARD THE UP OF
MICHIGAN. THIS FEATURE WILL BRING A COLD FRONT THROUGH THE REGION
EARLY THIS AFTERNOON WITH WINDS SHIFTING TO THE NORTHWEST AND
BECOMING STRONG POST-FROPA. NOT A WHOLE LOT OF CHANGES TO THE
GOING WIND FORECAST WITH A TIGHTENING SURFACE PRESSURE
GRADIENT...STRONG LOW LEVEL COLD AIR ADVECTION AND 3HR PRESSURE
RISES OF 6-8MB SHOULD ALL LEAD TO STRONG AND GUSTY WINDS FOR A 6
TO 9 HOUR PERIOD LATE THIS AFTERNOON AND EVENING. SUBSIDENT AIR
SHOULD HELP TO MIX DOWN SOME HIGHER GUSTS IN THE 45-50MPH
RANGE...PARTICULARLY IN THE HIGHER ELEVATIONS IN SOUTHEAST
MINNESOTA AND NORTHEAST IOWA. BASED ON ALL THIS...THE WIND
ADVISORY STILL LOOKS GOOD FOR THE REGION STARTING MID AFTERNOON
AND ENDING AROUND MIDNIGHT AS THE WINDS DIMINISH.
ANOTHER FEATURE WITH THIS FRONT IS THE BRIEF SHOT OF SNOW THAT
WILL COME WITH IT. THE 19.00Z NAM AND MESO-MODELS SHOW A BAND OF
SNOW FORMING OUT AHEAD OF THE COLD FRONT WHERE THE OVERALL FORCING
IS A LITTLE STRONGER ACROSS SOUTHEAST MINNESOTA AND NORTH CENTRAL
WISCONSIN. THIS WILL LEAD TO A SHORT PERIOD...LIKELY LESS THAN AN
HOUR...OF SNOW WHICH COULD BRIEFLY BE HEAVY. THIS COULD LEAD TO A
BRIEF DUSTING OF AROUND A HALF INCH OF SNOW AS IT COMES THROUGH.
KEPT SOME FLURRIES THROUGH THE NIGHT ACROSS MUCH OF THE REGION DUE
TO THE LOW LEVEL SATURATED LAYER BEING IN THE ICE LAYER OF -8C TO
-20C...THOUGH THEY MAY NOT OCCUR IF THE SUBSIDENCE IS TOO STRONG
AND CLEARS THINGS OUT.
ALTHOUGH WINDS WILL BE ON THE DECREASE AFTER MIDNIGHT...THEY WILL
STILL BE IN THE 10-20MPH RANGE AS THE COLDER AIR MOVES INTO THE
REGION. BASED ON THE TEMPERATURE/WIND FORECAST...THERE COULD BE
SOME -20F TO -25F WIND CHILLS THAT OCCUR ACROSS PORTIONS OF
SOUTHEAST MINNESOTA AND NORTH CENTRAL WISCONSIN. THIS MAY WARRANT
THE NEED FOR A WIND CHILL ADVISORY ONCE THE WIND ADVISORY ENDS.
MAY STILL GO FOR ONE THIS MORNING...BUT AM STILL WORKING ON THE
COLLABORATION WITH NEIGHBORING OFFICES AT THE MOMENT ON WHETHER
TO GO FOR IT NOW OR LATER TODAY.
BEYOND THIS ITS ALL ABOUT HOW COLD TEMPERATURES WILL GET WITH
LITTLE TO NO SNOW PACK OUT THERE. A WEAKENING MID LEVEL TROUGH
THAT HAS LITTLE LOW LEVEL SUPPORT WILL MOVE THROUGH ON SUNDAY AND
COULD PROVIDE ANOTHER DUSTING OF SNOW...THOUGH CONFIDENCE IS NOT
VERY HIGH ON THIS WITH THE WEAK MID LEVEL LIFT. HAD THE SNOW PACK
NOT ERODED AWAY LAST WEEK...OUR TEMPERATURES WOULD LIKELY BE ABOUT
10 DEGREES COLDER THAN WHAT IS BEING FORECAST. DESPITE THIS...THE
GUIDANCE ALL REMAINS IN GOOD AGREEMENT OF HAVING SUB-ZERO
TEMPERATURES IN PLACE TO START NEXT WEEK. WIND CHILL ADVISORIES
WILL DEFINITELY BE NEEDED FROM MONDAY MORNING THROUGH TUESDAY
MORNING WITH WIND CHILLS IN THE -20F TO -30F RANGE.
.LONG TERM...TUESDAY THROUGH FRIDAY
318 AM CST SAT JAN 19 2013
THE COLD AIR MASS APPEARS TO REMAIN IN PLACE ACROSS THE UPPER
MISSISSIPPI RIVER VALLEY THROUGH THE REST OF THE WEEK THOUGH IT
DOES MODERATE SOME GOING INTO WEDNESDAY AND BEYOND AS THE RIDGE
AXIS MOVES THROUGH AND THE CORE OF COLD LOW LEVEL AIR SHIFTS TO
THE EAST. THERE ARE SOME HINTS THAT A SYSTEM WILL DROP DOWN
THROUGH THE NORTHWEST FLOW ALOFT TUESDAY INTO TUESDAY NIGHT WHICH
COULD BRING SOME SNOW ALONG WITH IT. THE 19.00Z GFS IS THE ONLY
MODEL SHOWING THIS SNOW REACHING THE FORECAST AREA WITH THE 19.00Z
ECMWF PLACING THE SURFACE RIDGE RIGHT ALONG THE MISSISSIPPI RIVER.
SHOULD THE GFS PAN OUT...THERE COULD BE SOME HIGH RATIO SNOW THAT
OCCURS WITH 19.00Z BUFKIT SOUNDINGS SHOWING A DEEP DENDRITIC GROWTH
ZONE FROM THE SURFACE ON UP TO 700MB. THE BEST CHANCES FOR AN
ACCUMULATING SNOW IS WITH A SYSTEM THAT MAY COME IN ON THURSDAY OR
FRIDAY. THE 19.00Z GFS IS SLOW WITH THIS SYSTEM AND BRINGS IT IN
THURSDAY NIGHT INTO FRIDAY WHILE THE 19.00Z ECMWF HAS IT THROUGH
BY THURSDAY. THE 19.00Z GFS BUFKIT SOUNDINGS ARE EVEN DEEPER WITH
THE DENDRITIC GROWTH ZONE AND LIFT WITH THIS SYSTEM...WHICH COULD
AGAIN LEAD TO A HIGH SNOW TO LIQUID RATIO SNOW. TRENDED LOWER ON
TEMPERATURES ON THURSDAY WITH GUIDANCE SHOWING THIS SYSTEM
TRENDING A BIT FURTHER TO THE SOUTH.
&&
.AVIATION...THROUGH 18Z SUNDAY
1135 AM CST SAT JAN 19 2013
ARCTIC FRONT CONTINUES ITS MARCH TOWARDS THE TAF SITES AND AS OF
17Z STRETCHED FROM NEAR ABERDEEN SD TO DULUTH MN. AHEAD OF THE
FRONT...WINDS ARE TURNING WESTERLY AND SHOULD START GUSTING
SHORTLY TO 25 KT AT KRST DUE TO DAYTIME MIXING. KLSE IS A LITTLE
MORE PROTECTED BY THE VALLEY...BUT STILL BY 20Z ANTICIPATING
GUSTS TO DEVELOP THERE. VFR CONDITIONS ANTICIPATED UNTIL THE ARCTIC
FRONT ARRIVES DUE TO DRY LOW LEVEL AIR IN PLACE.
ARCTIC FRONT SHOULD REACH KRST AROUND 21Z AND KLSE AROUND 22Z.
IMMEDIATELY IN ITS WAKE...WINDS VEER TOWARDS THE NORTHWEST AND
RAPIDLY INCREASE. EXPECTING BOTH TAF SITES TO SEE SUSTAINED WINDS
OF 25-30 KT WITH GUSTS OF 40-45 KT WHICH WILL LAST THROUGH MUCH OF
THE EVENING. THE STRONG WINDS ARE A RESULT OF ARCTIC AIR
FLOWING...PRESSURES RISING RAPIDLY AND THE LOW PRESSURE AREA
RESPONSIBLE FOR A TIGHT PRESSURE GRADIENT OVER THE TAF SITES
DEEPENING AS IT CROSSES LAKE SUPERIOR. ALONG WITH THE FRONT WILL
COME A BAND OF MVFR STRATUS WITH SOME FLURRIES/SNOW SHOWERS.
VISIBILITIES MAY DROP TO IFR VERY BRIEFLY...BUT MVFR SEEMS MORE
LIKELY SINCE THE SNOW SHOWER COVERAGE SHOULD BE SCATTERED AT BEST.
KEPT THE TEMPO GROUP OF MVFR VISIBILITY TIL 00Z WHEN SNOW SHOWERS
ARE MOST LIKELY.
UPSTREAM...CLEARING CAN BE SEEN DROPPING INTO NORTHERN NORTH
DAKOTA. ANTICIPATING THIS TO REACH THE TAF SITES AROUND 06Z TO
HELP SCATTER OUT THE MVFR CLOUD DECK...LEADING TO VFR CONDITIONS
AFTERWARDS THROUGH 18Z SUNDAY. PLAN ON WINDS TO GRADUALLY DIMINISH
AS WELL BETWEEN 06-18Z SUNDAY...STAYING THE STRONGEST AT KLSE
BEING CLOSER TO THE SURFACE LOW AND FARTHEST AWAY FROM ARCTIC HIGH
PRESSURE BUILDING INTO WESTERN MINNESOTA.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
551 AM CST SAT JAN 19 2013
WI...WIND ADVISORY FROM 3 PM THIS AFTERNOON TO MIDNIGHT CST TONIGHT
FOR WIZ017-029-032>034-041>044-053>055-061.
WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM CST SUNDAY FOR
WIZ017-029.
MN...WIND ADVISORY FROM 3 PM THIS AFTERNOON TO MIDNIGHT CST TONIGHT
FOR MNZ079-086>088-094>096.
IA...WIND ADVISORY FROM 3 PM THIS AFTERNOON TO MIDNIGHT CST TONIGHT
FOR IAZ008>011-018-019-029-030.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1130 AM CST SAT JAN 19 2013
UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE
.UPDATE...THE LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW
AN AREA OF MIXED PRECIPITATION OVER NE WISCONSIN LATE THIS
MORNING. THIS PRECIPITATION SHOULD EXIT BY AROUND MIDDAY...BUT
COULD STILL LEAD TO SLICK ROADWAYS OVER DOOR COUNTY WHERE
TEMPERATURES ARE CURRENTLY IN THE UPPER 20S. LOOKING AHEAD...A
STRONG SHORTWAVE AND ARCTIC COLD FRONT ARE NOW MOVING QUICKLY EAST
OVER NORTHERN MINNESOTA. BOTH THE 12Z NAM AND RUC SHOW THESE
FEATURES REACHING NORTH-CENTRAL AND CENTRAL WISCONSIN AROUND
20-21Z AND NORTHEAST WISCONSIN BY AROUND 00Z. UPSTREAM OBS OVER
NORTH DAKOTA AND NORTHERN MINNESOTA SHOW OBS IN THE 1-3SM
RANGE...AND SUPPORT GOING WITH LIKELY SNOW SHOWERS OVER N-C
WISCONSIN LATE THIS AFTERNOON. ALSO HAVE OBSERVED SEVERAL WIND
GUSTS IN THE UPPER 30S TO LOWER 40S KTS BEHIND THE FRONT...WHERE A
STRONG ISALLOBARIC COMPONENT IS LEADING TO HIGHER GUSTS. SINCE THE
COLDER AIR BEHIND THE FRONT IS NOT PROGGED TO ARRIVE OVER THE FOX
VALLEY AND LAKESHORE UNTIL 00Z...HAVE DELAYED THE WIND ADVISORY
HEADLINES BY A FEW HOURS THERE. THE BEST PERIOD OF WIND IS DUE TO
ARRIVE LATE THIS AFTERNOON THROUGH LATE THIS EVENING WHEN THE
STRONGEST DESCENDING MOTION AND ISALLOBARIC PUSH ARRIVE. THINK
THE ADVISORY ENDING TIME IS A BIT TOO LONG...BUT WILL RE-EXAMINE
THAT LATER.
MPC
&&
.PREV DISCUSSION...ISSUED AT 625 AM CST SAT JAN 19 2013.
SHORT TERM...TODAY THROUGH SUNDAY...PCPN TRENDS...STRONG WINDS...
FALLING TEMPERATURES AND ASSOCIATED WIND ADVISORY/WIND
CHILL/MARINE HEADLINES ARE THE MAIN FCST CONCERNS.
CLIPPER LOW OVER NE ND/NW MN WILL TRACK THROUGH THE UPPER PENINSULA
OF MICHIGAN TODAY...AND DRAG AN ARCTIC COLD FRONT THROUGH THE FCST
AREA THIS AFTERNOON. SCT SNOW SHOWERS SEEN OVER THER MN ARROWHEAD
AND FAR NW WI SHOULD BRUSH THROUGH NORTHERN WI THIS MORNING...AND
ADDITIONAL SNOW SHOWERS WILL ACCOMPANY THE COLD FRONT THIS AFTERNOON.
ALTHOUGH MOISTURE IS LACKING WITH THIS SYSTEM...VERY STG DYNAMICS
ASSOC WITH A STG S/W TROF...THE LFQ OF AN UPPER LEVEL JET...DEEP
MID-LEVEL FRONTOGENTIC FORCING AND STEEP 850-700 MB LAPSE RATES
WILL HELP GENERATE SCT MODERATE SNOW SHOWERS ALONG THE FRONT THIS
AFTERNOON. THIS COULD END UP BEING A HISA (HIGH IMPACT SUB-ADVISORY)
EVENT...AS LOCALLY POOR VISIBILITIES WILL LIKELY OCCUR...AND WET
ROADS WILL QUICKLY FREEZE AS TEMPERATURES PLUMMET BEHIND THE
FRONT LATE THIS AFTERNOON. WILL MENTION THIS POSSIBILITY IN THE
HWO...AND ADD AN EXTRA PARAGRAPH ABOUT IT IN THE WIND ADVISORY
STATEMENT. THE DAY SHIFT CAN ISSUE AN SPS IF THE SNOW SHOWERS AND
TRAVEL CONCERNS DEVELOP AS EXPECTED. HAVE MAINTAINED LIKELY POPS
ACROSS NC WI FOR THIS AFTERNOON...WHERE MOST PLACES SHOULD PICK UP
AN INCH OR SO OF SNOW THIS AFTERNOON. LOCALLY HIGHER AMOUNTS ARE
POSSIBLE IN VILAS COUNTY.
PCPN TRENDS WILL TRANSITION TO MORE OF A TYPICAL NW FLOW LAKE EFFECT
PATTERN TONIGHT INTO SUNDAY. THE SETUP IS NEVER PERFECT FOR BIG
ACCUMS...AS THE WIND TRAJECTORY IS BIT TOO WESTERLY AT TIMES...STG
SUBSIDENCE OCCURS AT TIMES...AND LLVL TEMPS BECOME TOO COLD FOR
DENDRITES BY MID-EVENING TONIGHT. PLAN TO MENTION ADDITIONAL
ACCUMS OF 1 TO 3 INCHES IN VILAS COUNTY TONIGHT AND ANOTHER INCH
ON SUNDAY.
STG CAA AND SUBSIDENCE IN THE WAKE OF THE FRONT...COMBINED WITH
925 MB WINDS 40-45 KTS/850 MB WINDS OF 45-55 KT...AND STEEP LLVL
LAPSE RATES...SHOULD RESULT IN WIND GUSTS TO 45 TO 50 MPH ACROSS
MOST OF C/EC WI AND THE LAKESHORE LATE THIS AFTERNOON AND TONIGHT.
HAVE ISSUED A WIND ADVISORY FOR THIS AREA. THE WINDS WILL SUBSIDE
A BIT OVERNIGHT...BUT THE COMBINATION OF WIND/TEMPS WILL PRODUCE
WIND CHILLS AS COLD AS -25 OVER MUCH OF NC/C WI OVERNIGHT INTO
SUNDAY MORNING. HAVE ISSUED A WIND CHILL ADVISORY FOR THAT AREA.
LONG TERM...SUNDAY NGT THRU NEXT FRI. THE MAIN STORY FOR THE
FIRST PART OF THE EXTENDED FCST TO BE THE ARCTIC BLAST WHICH WL
SETTLE OVER THE REGION WITH THE COLDEST AIR THIS WINTER SEASON.
NOT UNTIL THE WRN CONUS UPR RDG BREAKS DOWN AT MID-WEEK WL THE
ARCTIC AIR BEGIN TO LEAVE WI...TO QUICKLY BE FOLLOWED BY A
RELATIVELY STRONG/FAST-MOVING SHORTWAVE TROF ACROSS THE NRN TIER
OF STATES. THIS SYSTEM WOULD IMPACT NE WI THU-THU NGT AND BRING
THE NEXT CHC FOR MEASURABLE SNOW. TEMPS BY LATE IN THE WORK WEEK
SHOULD AT LEAST APPROACH NORMAL ALTHO ANOTHER COOL DOWN IS HINTED
AT BY THE MDLS FOR NEXT WEEKEND.
ARCTIC AIR WL CONT TO POUR INTO THE GREAT LAKES SUNDAY NGT WITH 8H
TEMPS OVER NW WI APPROACHING -30C. THE PRESSURE GRADIENT IS STILL
FAIRLY TIGHT BETWEEN THE DEPARTED CLIPPER OVER SE CANADA AND STRONG
HI PRES OVER THE NRN/CNTRL PLAINS. EXPECT TO SEE WIND CHILL
HEADLINES TO BE ISSUED WITH MIN TEMPS RANGING FROM THE MID-TEENS
BELOW ZERO N-CNTRL TO AROUND ZERO LAKESIDE...COUPLED WITH W-NW
WINDS AROUND 10 MPH...TO SEND WIND CHILLS INTO THE -20 TO -32
DEGREE RANGE. THESE W-NW WINDS ARE NOT A FAVORABLE TRAJ FOR HEAVY
LAKE EFFECT SNOW SHWRS OVER VILAS CNTY...HOWEVER ANTICIPATE SEEING
AT LEAST SCT SNOW SHWR ACTIVITY REACH THE FAVORED SNOWBELT AREAS
OF THE CNTY WITH PERHAPS UP TO AN INCH OF ACCUMULATION.
LITTLE CHANGE EXPECTED SYNOPTICALLY SPEAKING HEADED INTO MON WITH
THE NW FLOW ALOFT AND THE ARCTIC AIR MASS LOCKED IN OVER THE
REGION. THE BETTER LAKE EFFECT SNOW WL CONT TO FAVOR NW/ERN 1/3 OF
UPR MI WITH ONLY SCT ACTIVITY AFFECTING VILAS CNTY. TEMPS WL
REMAIN THE BIG STORY AS MUCH OF N-CNTRL AND CNTRL WI WL NOT GET
OUR OF THE NEGATIVE NUMBERS (GENERALLY ZERO TO 5 BELOW). ON TOP OF
THE VERY COLD TEMPS WL BE A SUSTAINED W-NW WIND OF 10 TO 20 MPH
WHICH WOULD PLACE WIND CHILL READINGS AT -20 DEGS OR COLDER FOR
ALMOST THE ENTIRE FCST AREA...THUS HEADLINES BY NEED TO BE
EXTENDED RIGHT THRU MON.
THE AREA OF HI PRES IS FCST TO EXTEND FROM THE UPR MS VALLEY TO
THE OZARKS MON NGT WITH WINDS BACKING A BIT MORE TO A 280 OR 290
DEGREE DIRECTION WHICH IS EVEN MORE OF AN UNFAVORABLE TRAJ TO
BRING LAKE EFFECT INTO VILAS CNTY...THUS AM NOT EXPECTING MUCH (IF
ANY ACCUMULATION). THERE WL BE SOME WIND THRU THE NGT WHICH WOULD
HELP TO PREVENT TEMPS FROM COMPLETELY FREE-FALLING. EVEN SO...MON
NGT APPEARS TO BE THE COLDEST NGT WITH READINGS DROPPING TO NEAR
20 BELOW ZERO N-CNTRL...AROUND 5 BELOW ZERO ALONG THE LK MI
SHORELINE. ADD IN SOME WIND AND WE ARE LOOKING AT ADDITIONAL WIND
CHILL HEADLINES FOR ALL OF NE WI. THE HI PRES FINALLY REACHES THE
WRN GREAT LAKES REGION ON TUE WHICH SHOULD ALLOW FOR WINDS TO
LIGHTEN UP (GENERALLY IN THE 5-10 MPH RANGE). THIS SFC HI DOES NOT
HAVE A LOT OF DRY AIR WITH IT AS FCST SOUNDINGS INDICATE SEVERAL
LAYERS OF MOISTURE...THUS PARTLY SUNNY SKIES WOULD BE THE BEST
CASE SCENARIO. MAX TEMPS WL AGAIN STRUGGLE TO REACH ZERO...ESPECIALLY
AFTER THE BITTERLY COLD START TO THE DAY. MAY NEED TO TAKE VALUES
DOWN A DEGREE OR TWO FROM THE PREVIOUS FCST.
CHANGES IN THE OVERALL SYNOPTIC PATTERN BEGINS TUE NGT AS THE WRN
CONUS UPR RDG STARTS TO MOVE TOWARD THE ROCKIES AND WEAKEN A BIT.
ONE MORE VERY COLD NGT ANTICIPATED ACROSS NE WI WITH THE SFC HI
PRACTICALLY OVERHEAD (THUS LIGHT WINDS). LOOK FOR MIN TEMPS TO
RANGE FROM 10 BELOW TO 15 BELOW NORTH TO AROUND ZERO LAKESIDE.
SOME MODERATION IN TEMPS IS EXPECTED ON WED AS THE SFC HI SHIFTS
TO OUR EAST ALLOWING WINDS TO BACK W-SW AND THE CORE OF THE UPR
TROF PULLS FARTHER EAST. IN ADDITION...THE UPR RDG QUICKLY BREAKS
DOWN OVER THE ROCKIES ALLOWING FOR SOME MILDER PACIFIC AIR TO
BEGIN MOVING INTO THE CNTRL CONUS.
SINCE THE MEAN FLOW TO BECOME LESS AMPLIFIED WITH THE BREAK DOWN
OF THE UPR RDG...THIS WL ALLOW FOR A PACIFIC SYSTEM TO RACE EWD
ACROSS THE CONUS WED NGT INTO FRI. AS ONE WOULD EXPECT...THE MDLS
ARE HAVING SERIOUS TIMING ISSUES WITH THIS SYSTEM...AS WELL AS THE
TRACK OF THE ACCOMPANYING SFC LOW. SIMPLY TAKING A ROUGH AVERAGE
OF THE MDLS WOULD FAVOR THIS SYSTEM AFFECTING NE WI DURING THE THU-
THU NGT TIME FRAME WITH SOME MEASURABLE SNOW. AMOUNTS COULD BE
LIMITED DUE TO THE SPEED OF THE SYSTEM OVERALL...BUT WAY TOO EARLY
TO DETERMINE SNOW EXTENT JUST YET. TEMPS ARE PROGGED TO WARM INTO
THE TEENS TO LWR 20S FOR BOTH THU AND FRI...BUT THERE ARE SIGNS OF
ANOTHER UPR RDG BUILDING ACROSS THE WRN CONUS TOWARD NEXT WEEKEND
WHICH COULD DUMP ANOTHER COLD AIR MASS INTO THE GREAT LAKES. THIS
AIR MASS WHILE COLD...WL NOT BE ANYTHING COMPARED TO THE IMPENDING
ARCTIC BLAST FROM EARLIER IN THE WEEK.
&&
.AVIATION...WHILE LIGHT MIXED PRECIPITATION HAS EXITED NORTHEAST
WISCONSIN...THE BIGGEST AVIATION HAZARDS WILL ACCOMPANY AN ARCTIC
COLD FRONTAL PASSAGE LATE THIS AFTERNOON AND THIS EVENING. SCT SNOW
SHOWERS ARE STILL EXPECTED TO DEVELOP ALONG THE FRONT...WITH LOCAL
VSBYS BLO 1SM. IN ADDITION...STRONG WEST WINDS WILL DEVELOP BEHIND
THE FRONT AS ARCTIC AIR POURS ACROSS THE STATE...WITH GUSTS TO 35 TO
40 KTS...HIGHEST ACROSS C/EC WI AND ALONG THE LAKESHORE. LAKE EFFECT
SNOW SHOWERS WILL DEVELOP IN NC WI TONIGHT...AND NW WINDS WILL BE
STRONG ENOUGH TO CARRY SOME SNOW INTO RHI. IMPROVING CONDITIONS
WILL OCCUR AFTER MIDNIGHT IN TERMS OF DIMINISHING WINDS...SNOW
SHOWERS...AND INCREASING CIGS. VFR CONDITIONS TOMORROW UNDER ARCTIC
HIGH PRESSURE.
MPC
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 6 PM THIS EVENING TO 3 AM CST SUNDAY FOR
WIZ038>040-048>050.
WIND ADVISORY FROM 3 PM THIS AFTERNOON TO MIDNIGHT CST TONIGHT
FOR WIZ030-031-035>037-045.
WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM CST SUNDAY FOR
WIZ005-010-011-018-019-030-035-036.
WIND ADVISORY FROM 6 PM THIS EVENING TO 6 AM CST SUNDAY FOR
WIZ022.
&&
$$
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1039 AM CST SAT JAN 19 2013
.UPDATE...THE LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW
AN AREA OF MIXED PRECIPITATION OVER NE WISCONSIN LATE THIS
MORNING. THIS PRECIPITATION SHOULD EXIT BY AROUND MIDDAY...BUT
COULD STILL LEAD TO SLICK ROADWAYS OVER DOOR COUNTY WHERE
TEMPERATURES ARE CURRENTLY IN THE UPPER 20S. LOOKING AHEAD...A
STRONG SHORTWAVE AND ARCTIC COLD FRONT ARE NOW MOVING QUICKLY EAST
OVER NORTHERN MINNESOTA. BOTH THE 12Z NAM AND RUC SHOW THESE
FEATURES REACHING NORTH-CENTRAL AND CENTRAL WISCONSIN AROUND
20-21Z AND NORTHEAST WISCONSIN BY AROUND 00Z. UPSTREAM OBS OVER
NORTH DAKOTA AND NORTHERN MINNESOTA SHOW OBS IN THE 1-3SM
RANGE...AND SUPPORT GOING WITH LIKELY SNOW SHOWERS OVER N-C
WISCONSIN LATE THIS AFTERNOON. ALSO HAVE OBSERVED SEVERAL WIND
GUSTS IN THE UPPER 30S TO LOWER 40S KTS BEHIND THE FRONT...WHERE A
STRONG ISALLOBARIC COMPONENT IS LEADING TO HIGHER GUSTS. SINCE THE
COLDER AIR BEHIND THE FRONT IS NOT PROGGED TO ARRIVE OVER THE FOX
VALLEY AND LAKESHORE UNTIL 00Z...HAVE DELAYED THE WIND ADVISORY
HEADLINES BY A FEW HOURS THERE. THE BEST PERIOD OF WIND IS DUE TO
ARRIVE LATE THIS AFTERNOON THROUGH LATE THIS EVENING WHEN THE
STRONGEST DESCENDING MOTION AND ISALLOBARIC PUSH ARRIVE. THINK
THE ADVISORY ENDING TIME IS A BIT TOO LONG...BUT WILL RE-EXAMINE
THAT LATER.
MPC
&&
.PREV DISCUSSION...ISSUED AT 625 AM CST SAT JAN 19 2013.
SHORT TERM...TODAY THROUGH SUNDAY...PCPN TRENDS...STRONG WINDS...
FALLING TEMPERATURES AND ASSOCIATED WIND ADVISORY/WIND
CHILL/MARINE HEADLINES ARE THE MAIN FCST CONCERNS.
CLIPPER LOW OVER NE ND/NW MN WILL TRACK THROUGH THE UPPER PENINSULA
OF MICHIGAN TODAY...AND DRAG AN ARCTIC COLD FRONT THROUGH THE FCST
AREA THIS AFTERNOON. SCT SNOW SHOWERS SEEN OVER THER MN ARROWHEAD
AND FAR NW WI SHOULD BRUSH THROUGH NORTHERN WI THIS MORNING...AND
ADDITIONAL SNOW SHOWERS WILL ACCOMPANY THE COLD FRONT THIS AFTERNOON.
ALTHOUGH MOISTURE IS LACKING WITH THIS SYSTEM...VERY STG DYNAMICS
ASSOC WITH A STG S/W TROF...THE LFQ OF AN UPPER LEVEL JET...DEEP
MID-LEVEL FRONTOGENTIC FORCING AND STEEP 850-700 MB LAPSE RATES
WILL HELP GENERATE SCT MODERATE SNOW SHOWERS ALONG THE FRONT THIS
AFTERNOON. THIS COULD END UP BEING A HISA (HIGH IMPACT SUB-ADVISORY)
EVENT...AS LOCALLY POOR VISIBILITIES WILL LIKELY OCCUR...AND WET
ROADS WILL QUICKLY FREEZE AS TEMPERATURES PLUMMET BEHIND THE
FRONT LATE THIS AFTERNOON. WILL MENTION THIS POSSIBILITY IN THE
HWO...AND ADD AN EXTRA PARAGRAPH ABOUT IT IN THE WIND ADVISORY
STATEMENT. THE DAY SHIFT CAN ISSUE AN SPS IF THE SNOW SHOWERS AND
TRAVEL CONCERNS DEVELOP AS EXPECTED. HAVE MAINTAINED LIKELY POPS
ACROSS NC WI FOR THIS AFTERNOON...WHERE MOST PLACES SHOULD PICK UP
AN INCH OR SO OF SNOW THIS AFTERNOON. LOCALLY HIGHER AMOUNTS ARE
POSSIBLE IN VILAS COUNTY.
PCPN TRENDS WILL TRANSITION TO MORE OF A TYPICAL NW FLOW LAKE EFFECT
PATTERN TONIGHT INTO SUNDAY. THE SETUP IS NEVER PERFECT FOR BIG
ACCUMS...AS THE WIND TRAJECTORY IS BIT TOO WESTERLY AT TIMES...STG
SUBSIDENCE OCCURS AT TIMES...AND LLVL TEMPS BECOME TOO COLD FOR
DENDRITES BY MID-EVENING TONIGHT. PLAN TO MENTION ADDITIONAL
ACCUMS OF 1 TO 3 INCHES IN VILAS COUNTY TONIGHT AND ANOTHER INCH
ON SUNDAY.
STG CAA AND SUBSIDENCE IN THE WAKE OF THE FRONT...COMBINED WITH
925 MB WINDS 40-45 KTS/850 MB WINDS OF 45-55 KT...AND STEEP LLVL
LAPSE RATES...SHOULD RESULT IN WIND GUSTS TO 45 TO 50 MPH ACROSS
MOST OF C/EC WI AND THE LAKESHORE LATE THIS AFTERNOON AND TONIGHT.
HAVE ISSUED A WIND ADVISORY FOR THIS AREA. THE WINDS WILL SUBSIDE
A BIT OVERNIGHT...BUT THE COMBINATION OF WIND/TEMPS WILL PRODUCE
WIND CHILLS AS COLD AS -25 OVER MUCH OF NC/C WI OVERNIGHT INTO
SUNDAY MORNING. HAVE ISSUED A WIND CHILL ADVISORY FOR THAT AREA.
LONG TERM...SUNDAY NGT THRU NEXT FRI. THE MAIN STORY FOR THE
FIRST PART OF THE EXTENDED FCST TO BE THE ARCTIC BLAST WHICH WL
SETTLE OVER THE REGION WITH THE COLDEST AIR THIS WINTER SEASON.
NOT UNTIL THE WRN CONUS UPR RDG BREAKS DOWN AT MID-WEEK WL THE
ARCTIC AIR BEGIN TO LEAVE WI...TO QUICKLY BE FOLLOWED BY A
RELATIVELY STRONG/FAST-MOVING SHORTWAVE TROF ACROSS THE NRN TIER
OF STATES. THIS SYSTEM WOULD IMPACT NE WI THU-THU NGT AND BRING
THE NEXT CHC FOR MEASURABLE SNOW. TEMPS BY LATE IN THE WORK WEEK
SHOULD AT LEAST APPROACH NORMAL ALTHO ANOTHER COOL DOWN IS HINTED
AT BY THE MDLS FOR NEXT WEEKEND.
ARCTIC AIR WL CONT TO POUR INTO THE GREAT LAKES SUNDAY NGT WITH 8H
TEMPS OVER NW WI APPROACHING -30C. THE PRESSURE GRADIENT IS STILL
FAIRLY TIGHT BETWEEN THE DEPARTED CLIPPER OVER SE CANADA AND STRONG
HI PRES OVER THE NRN/CNTRL PLAINS. EXPECT TO SEE WIND CHILL
HEADLINES TO BE ISSUED WITH MIN TEMPS RANGING FROM THE MID-TEENS
BELOW ZERO N-CNTRL TO AROUND ZERO LAKESIDE...COUPLED WITH W-NW
WINDS AROUND 10 MPH...TO SEND WIND CHILLS INTO THE -20 TO -32
DEGREE RANGE. THESE W-NW WINDS ARE NOT A FAVORABLE TRAJ FOR HEAVY
LAKE EFFECT SNOW SHWRS OVER VILAS CNTY...HOWEVER ANTICIPATE SEEING
AT LEAST SCT SNOW SHWR ACTIVITY REACH THE FAVORED SNOWBELT AREAS
OF THE CNTY WITH PERHAPS UP TO AN INCH OF ACCUMULATION.
LITTLE CHANGE EXPECTED SYNOPTICALLY SPEAKING HEADED INTO MON WITH
THE NW FLOW ALOFT AND THE ARCTIC AIR MASS LOCKED IN OVER THE
REGION. THE BETTER LAKE EFFECT SNOW WL CONT TO FAVOR NW/ERN 1/3 OF
UPR MI WITH ONLY SCT ACTIVITY AFFECTING VILAS CNTY. TEMPS WL
REMAIN THE BIG STORY AS MUCH OF N-CNTRL AND CNTRL WI WL NOT GET
OUR OF THE NEGATIVE NUMBERS (GENERALLY ZERO TO 5 BELOW). ON TOP OF
THE VERY COLD TEMPS WL BE A SUSTAINED W-NW WIND OF 10 TO 20 MPH
WHICH WOULD PLACE WIND CHILL READINGS AT -20 DEGS OR COLDER FOR
ALMOST THE ENTIRE FCST AREA...THUS HEADLINES BY NEED TO BE
EXTENDED RIGHT THRU MON.
THE AREA OF HI PRES IS FCST TO EXTEND FROM THE UPR MS VALLEY TO
THE OZARKS MON NGT WITH WINDS BACKING A BIT MORE TO A 280 OR 290
DEGREE DIRECTION WHICH IS EVEN MORE OF AN UNFAVORABLE TRAJ TO
BRING LAKE EFFECT INTO VILAS CNTY...THUS AM NOT EXPECTING MUCH (IF
ANY ACCUMULATION). THERE WL BE SOME WIND THRU THE NGT WHICH WOULD
HELP TO PREVENT TEMPS FROM COMPLETELY FREE-FALLING. EVEN SO...MON
NGT APPEARS TO BE THE COLDEST NGT WITH READINGS DROPPING TO NEAR
20 BELOW ZERO N-CNTRL...AROUND 5 BELOW ZERO ALONG THE LK MI
SHORELINE. ADD IN SOME WIND AND WE ARE LOOKING AT ADDITIONAL WIND
CHILL HEADLINES FOR ALL OF NE WI. THE HI PRES FINALLY REACHES THE
WRN GREAT LAKES REGION ON TUE WHICH SHOULD ALLOW FOR WINDS TO
LIGHTEN UP (GENERALLY IN THE 5-10 MPH RANGE). THIS SFC HI DOES NOT
HAVE A LOT OF DRY AIR WITH IT AS FCST SOUNDINGS INDICATE SEVERAL
LAYERS OF MOISTURE...THUS PARTLY SUNNY SKIES WOULD BE THE BEST
CASE SCENARIO. MAX TEMPS WL AGAIN STRUGGLE TO REACH ZERO...ESPECIALLY
AFTER THE BITTERLY COLD START TO THE DAY. MAY NEED TO TAKE VALUES
DOWN A DEGREE OR TWO FROM THE PREVIOUS FCST.
CHANGES IN THE OVERALL SYNOPTIC PATTERN BEGINS TUE NGT AS THE WRN
CONUS UPR RDG STARTS TO MOVE TOWARD THE ROCKIES AND WEAKEN A BIT.
ONE MORE VERY COLD NGT ANTICIPATED ACROSS NE WI WITH THE SFC HI
PRACTICALLY OVERHEAD (THUS LIGHT WINDS). LOOK FOR MIN TEMPS TO
RANGE FROM 10 BELOW TO 15 BELOW NORTH TO AROUND ZERO LAKESIDE.
SOME MODERATION IN TEMPS IS EXPECTED ON WED AS THE SFC HI SHIFTS
TO OUR EAST ALLOWING WINDS TO BACK W-SW AND THE CORE OF THE UPR
TROF PULLS FARTHER EAST. IN ADDITION...THE UPR RDG QUICKLY BREAKS
DOWN OVER THE ROCKIES ALLOWING FOR SOME MILDER PACIFIC AIR TO
BEGIN MOVING INTO THE CNTRL CONUS.
SINCE THE MEAN FLOW TO BECOME LESS AMPLIFIED WITH THE BREAK DOWN
OF THE UPR RDG...THIS WL ALLOW FOR A PACIFIC SYSTEM TO RACE EWD
ACROSS THE CONUS WED NGT INTO FRI. AS ONE WOULD EXPECT...THE MDLS
ARE HAVING SERIOUS TIMING ISSUES WITH THIS SYSTEM...AS WELL AS THE
TRACK OF THE ACCOMPANYING SFC LOW. SIMPLY TAKING A ROUGH AVERAGE
OF THE MDLS WOULD FAVOR THIS SYSTEM AFFECTING NE WI DURING THE THU-
THU NGT TIME FRAME WITH SOME MEASURABLE SNOW. AMOUNTS COULD BE
LIMITED DUE TO THE SPEED OF THE SYSTEM OVERALL...BUT WAY TOO EARLY
TO DETERMINE SNOW EXTENT JUST YET. TEMPS ARE PROGGED TO WARM INTO
THE TEENS TO LWR 20S FOR BOTH THU AND FRI...BUT THERE ARE SIGNS OF
ANOTHER UPR RDG BUILDING ACROSS THE WRN CONUS TOWARD NEXT WEEKEND
WHICH COULD DUMP ANOTHER COLD AIR MASS INTO THE GREAT LAKES. THIS
AIR MASS WHILE COLD...WL NOT BE ANYTHING COMPARED TO THE IMPENDING
ARCTIC BLAST FROM EARLIER IN THE WEEK.
&&
.AVIATION...LOW CLOUDS REMAINED ACROSS FAR NORTHERN WI EARLY THIS
MORNING...AND SCT SNOW SHOWERS WILL LIKELY IMPACT THAT AREA THIS
MORNING. HOWEVER...THE BIGGEST AVIATION HAZARDS WILL ACCOMPANY AN
ARCTIC COLD FRONTAL PASSAGE THIS AFTERNOON. SCT SNOW SHOWERS WILL
DEVELOP ALONG THE FRONT...WITH LOCAL VSBYS BLO 1SM. IN ADDITION...
STRONG WEST WINDS WILL DEVELOP LATE THIS AFTERNOON AND TONIGHT...
WITH GUSTS TO 35 TO 45 KTS...HIGHEST ACROSS C/EC WI AND ALONG THE
LAKESHORE. LAKE EFFECT SNOW SHOWERS WILL DEVELOP IN NC WI LATER
TODAY INTO TONIGHT...ESPECIALLY ACROSS VILAS COUNTY.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 6 PM THIS EVENING TO 3 AM CST SUNDAY FOR
WIZ038>040-048>050.
WIND ADVISORY FROM 3 PM THIS AFTERNOON TO MIDNIGHT CST TONIGHT
FOR WIZ030-031-035>037-045.
WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM CST SUNDAY FOR
WIZ005-010-011-018-019-030-035-036.
WIND ADVISORY FROM 6 PM THIS EVENING TO 6 AM CST SUNDAY FOR
WIZ022.
&&
$$