Forecast Discussions mentioning any of
"HRRR" "RR" "RUC13" "RUC" received at GSD on 01/13/12
EAST CENTRAL FLORIDA FORECAST DISCUSSION
NWS MELBOURNE FL
822 PM EST THU JAN 12 2012
.DISCUSSION...
CURRENTLY-TONIGHT...LTST SATELLITE/OBS SHOW THE APCHG COLD FRONT
JUST EAST OF TALLAHASSEE AND THE LTST RUC GUID SHOWS THE FRONTAL
BOUNDARY ACCOMPANIED BY A MODEST BUT TEMPORARY INCREASE IN CLOUDS
AND LACKING ANY MENTIONABLE RAINFALL WILL PUSH INTO CENTRAL FL
AROUND 2 AM...AND IN THE PROCESS OF CLEARING THE TREASURE COAST
AROUND SUNRISE. WINDS ARE EXPECTED TO INCREASE AFTER PSG OF THE
FRONT BUT INCREASE SHOULD ONLY PERSIST IN THE 10 TO 15 MPH RANGE
UNTIL AROUND LATE MORNING TO MIDDAY.
DESPITE PSG OF THE FRONT BEFORE DAYBREAK MOST OF THE AREA ASIDE FROM
WEST OF I4 SHOULD REMAIN IN THE LOWER 50S WITH MID TO UPPER 50S
SOUTH OF THE FRONT ALONG THE SPACE AND TREASURE COASTS. THE FORECAST
IS IN GOOD SHAPE REGARDING TIMING AND NO UPDTS ARE PLANNED.
&&
.AVIATION...VFR AREA WIDE.
&&
.MARINE...
TONIGHT-FRI...INCREASED GRADIENT WINDS AHEAD OF APCHG FRONT
WARRANTED ADVISORY COMMENCEMENT AT 7 PM OVER THE NORTHERN WATERS
WITH SWD PROGRESSION OF HIGHER WINDS ASCD WITH PSG OF THE FRONT LATE
TONIGHT. FETCH LIMITED SEAS WILL BE SLOWER TO RESPOND AND MARINERS
SHOULD TAKE NOTE THAT THE WINDS/SEAS AWAY FROM THE COAST EARLY FRI
MORNING WILL BE WORSE THAN WHAT ARE EXPERIENCED AT THE COAST.
HOWEVER...THE FORECAST MODELS INDICATE WINDS DROPPING TO AROUND 10
KNOTS BY LATE AFTERNOON.
&&
.FIRE WEATHER...
FRI...MIN RH VALUES AROUND 25 PERCENT WILL OCCUR ACROSS THE INTERIOR
EXCEPT OKEECHOBEE AND THE SOUTH COAST. FORECAST FUEL MOISTURE
VALUES IN A FEW ZONES ARE ABOVE 30 THRESHOLD FOR ISSUANCE OF A
DANGER STMT AND A PORTION OF THE INTERIOR ALONG WITH ALL OF VOLUSIA
COUNTY MAY REQUIRE ISSUANCE EARLY FRIDAY.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY FOR WINDS UNTIL 1 PM
EST FRIDAY FOR COASTAL WATERS FROM FLAGLER BEACH TO VOLUSIA
BREVARD COUNTY LINE OUT 20 NM-WATERS FROM FLAGLER BEACH TO
VOLUSIA BREVARD COUNTY LINE 20 TO 60 NM OFFSHORE.
SMALL CRAFT ADVISORY FOR WINDS FROM 10 PM THIS EVENING TO 1 PM
EST FRIDAY FOR COASTAL WATERS FROM VOLUSIA BREVARD COUNTY
LINE TO SEBASTIAN INLET OUT 20 NM-WATERS FROM VOLUSIA
BREVARD COUNTY LINE TO SEBASTIAN INLET 20 TO 60 NM OFFSHORE.
SMALL CRAFT ADVISORY FOR WINDS FROM 1 AM TO 1 PM EST FRIDAY FOR
WATERS FROM SEBASTIAN INLET TO JUPITER INLET 20 TO 60 NM
OFFSHORE.
SMALL CRAFT ADVISORY FOR WINDS FROM 4 AM TO 1 PM EST FRIDAY FOR
COASTAL WATERS FROM SEBASTIAN INLET TO JUPITER INLET OUT 20
NM.
&&
$$
JP/AC
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
516 PM CST THU JAN 12 2012
.AVIATION...
IFR TO BRIEF LIFR CONDITIONS WITH SNOW WILL CONTINUE THROUGH
023Z/13. AFT 02Z/13 CONDITIONS WILL SLOWLY IMPROVE TO MVFR. SNOW
INTENSITY WILL DECREASE RAPIDLY AFT 02Z/13 AND TAPER TO FLURRIES
BEFORE ENDING. VSBYS TO BECOME VFR AFT 06Z/13 WITH MVFR CIGS.
AFTER 15Z...CLEARING TO FULL VFR CONDITIONS AND LIGHTER WINDS WILL
SWEEP THROUGH FROM WEST TO EAST...REACHING MLI AND DBQ BY LATE MORNING.
..ERVIN..
&&
.PREV DISCUSSION... /ISSUED 339 PM CST THU JAN 12 2012/
SYNOPSIS...
12Z UA ANALYSIS HAD AN 850MB LOW ALONG THE IA/WI BORDER WITH
ANOTHER IN SOUTHEAST LOWER MICHIGAN. A TROF EXTENDED SOUTH FROM
THE IA/WI LOW INTO SOUTHEAST MISSOURI. RADAR TRENDS THROUGH EARLY
AFTERNOON SHOW AN UPPER LEVEL FEATURE THAT IS PIVOTING A
DEFORMATION ZONE ACROSS EASTERN IOWA AND NORTHERN ILLINOIS.
18Z SFC ANALYSIS HAS AN OCCLUDED LOW BETWEEN KGRR AND KAZO AND
ANOTHER ON THE SOUTHERN EDGE OF LAKE HURON. THE POLAR FRONT
EXTENDED SOUTH FROM THE OCCLUDED LOW INTO CENTRAL ALABAMA. SEVERAL
WEAK TROFS RAN FROM SOUTHERN LAKE MICHIGAN INTO MISSOURI BACK UP
INTO SOUTHERN WISCONSIN AND IOWA. DEW POINTS WERE IN THE TEENS AND
20S FROM THE WESTERN GREAT LAKES AND LOWER MISSISSIPPI VALLEY TO
THE SINGLE DIGITS ABOVE AND BELOW ZERO ACROSS THE PLAINS.
SHORT TERM...TONIGHT...
RADAR AND WATER VAPOR ARE QUITE INTERESTING. A VORT MAX IS
ROTATING AROUND THE UPPER LOW IN SOUTHERN ILLINOIS WHICH IS
HELPING TO PIVOT THE DEFORMATION ZONE ACROSS THE CWFA. THE END
POINT OF THE PIVOT IS SLOWLY DRIFTING TO THE EAST SOUTHEAST AS THE
UPPER LOW MOVES INTO THE OHIO VALLEY PER RUC TRENDS. THUS LIGHT TO
MODERATE SNOW WITH BURSTS OF HEAVY SNOW WILL CONTINUE THROUGH 6 PM.
THE RUC SHOWS ANOTHER VORT MAX ROTATING FROM NORTHEAST ILLINOIS
BACK INTO EASTERN IOWA DURING THE EARLY EVENING. THIS FEATURE
SHOULD ALLOW THE SNOW TO MAINTAIN ITSELF THROUGH 9 PM. AFTER 9 PM
THE FORCING OVER THE WESTERN THIRD OF THE CWFA WEAKENS RAPIDLY SO
THE SNOW THERE SHOULD QUICKLY TAPER TO FLURRIES.
THE RUC TRENDS BLEND IN NICELY WITH THE WRF/GFS TRENDS INDICATING
THE OVERALL FORCING WEAKENING RAPIDLY AFTER MIDNIGHT ACROSS THE
EASTERN TWO THIRDS OF THE CWFA. THUS SNOW WILL TAPER TO FLURRIES
ACROSS THE REMAINDER OF THE CWFA AFTER MIDNIGHT WITH ALL BUT THE
FAR EASTERN PARTS OF THE CWFA SEEING THE FLURRIES END PRIOR TO
SUNRISE.
THE CURRENT HEADLINES WILL REMAIN AS IS FOR NOW. IF THE TRENDS
FROM THE RUC AND OTHER MODELS ARE CORRECT...THE POSSIBILITY DOES
EXIST THAT THE HEADLINES MAY BE CANCELLED EARLIER THAN THE CURRENT
END TIMES.
NOW FOR AMOUNTS. ADDITIONAL SNOWFALL THIS EVENING SHOULD RANGE
FROM A DUSTING IN THE FAR WESTERN PARTS OF THE CWFA TO JUST OVER
AN INCH IN THE EASTERN THIRD OF THE CWFA. MOST OF THIS ADDITIONAL
SNOWFALL WILL OCCUR BETWEEN 6 AND 8 PM. AFTER MIDNIGHT...AN
ADDITIONAL DUSTING MAY OCCUR IN THE EASTERN THIRD OF THE CWFA
WHERE LIGHT SNOW WILL LINGER THE LONGEST.
SO...STORM TOTALS SHOULD BE A GENERAL 3 TO 6 INCHES ACROSS THE
AREA. AN AREA 20 MILES EITHER SIDE OF A LINE CENTERED FROM CEDAR
RAPIDS TO ROUGHLY STERLING SHOULD SEE 5 TO 7 INCHES WITH LOCALLY
HIGHER AMOUNTS.
..08..
LONG TERM...FRIDAY THROUGH NEXT THURSDAY...
ACTIVE PATTERN TO PREVAIL THROUGH THE PERIOD.
FRI-FRI NGT...ADDITIONAL ENERGY DIVING DOWN BACKSIDE OF DEPARTING
SYSTEM WILL KEEP CLOUDS AND POSSIBLY FEW FLURRIES AROUND
FOR A TIME FRI AM. THEN EXPECT SOME DECREASE IN CLOUDS FRI AFTN
WITH SUBSIDENCE. BRISK NW WINDS CONTINUE AND WITH CLOUDS SLOW TO
DECREASE AND FRESH SNOW HAVE SIDED AT OR BELOW COLD SIDE OF GUIDANCE
FOR HIGHS. NEXT CLIPPER SYSTEM WHICH SEEN ON WATER VAPOR JUST
COMING INTO BC APPEARS TO BE A LITTLE STRONGER THAT PROGGED. THIS
ENERGY TO HEAD SE FRI NGT AND WILL SEE INCREASE IN CLOUDS WITH WARM
ADVECTION WING WITH CHC OF -SN/--SN LATE PORTIONS OF W/NW. LIGHT
WINDS AND PARTIAL CLEARING FOR TIME FRI EVE SHOULD AID IN QUICK DROP
TO NEAR OR BELOW GUIDANCE MINS BEFORE TEMPS STEADY OR RISE WITH
CLOUDS AND LLVL WARM ADVECTION OVRNGT.
SAT-SAT NGT...CLIPPER SYSTEM TO PASS DURING DAY WITH STILL PLENTY
OF SPREAD ON TRACK AND STRENGTH. ENHANCED BAROCLINICITY FROM
EVOLVING SNOW FIELD MAY PLAY ROLE... AND GIVEN THIS AND WHAT LOOKS
LIKE STRONGER WAVE WONDER IF TRACK AND POPS MAY NEED TO BE
ADJUSTED SWWD. LIMITED MOISTURE AND SO COULD END UP MOSTLY FLURRIES
WITH AREAS OF -SN WITH ANY ACCUMS MINOR AT OR BELOW 1 INCH. AT LEAST
PARTIAL CLEARING SAT NGT IN WAKE WITH LIGHT WINDS AND HAVE LOWERED
MINS TO BELOW GUIDANCE... BUT RETURN FLOW KICKS IN LATE THAT MAY SEE
TEMPS CLIMB OVRNGT.
SUN-SUN NGT... DRY WITH MODERATING TEMPS AS WARM ADVECTION STRENGTHENS
ON GUSTY SLY WINDS... WITH HEIGHTS BUILDING ALOFT. FRONT MOVES INTO
IA SUN NGT BUT SUGGESTION OF PCPN STAYING SOUTH OF CWA ACROSS PORTIONS
OF MO SWD WITHIN DEEPER LLVL MOISTURE RETURN.
MON-TUE... NEXT FRONT TO PASS WITH ENERGY AND BAROCLINICITY FAVORING
SFC LOW DEVELOPMENT ALONG FRONT PASSING NEAR REGION THAT MAY
REQUIRE POPS BEING RAISED. THERMAL PARAMETERS SUPPORT MAINLY RAIN MON
BUT AS FRONT SAGS ACROSS CWA MON NGT AND COLDER AIR MOVES IN COULD
SEE MIX THEN CHANGE TO SNOW WITH ANY RESIDUAL MOISTURE ON BACKSIDE
LINGERING INTO TUE. ANY SNOW ACCUMS WOULD APPEAR TO BE LIGHT ATTIM.
WED-THU...MUCH COLDER WITH CHC OF SNOW LATE PD WITH NEXT BOUT OF ENERGY.
..05..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...WINTER STORM WARNING UNTIL 3 AM CST FRIDAY FOR CLINTON-JACKSON-
SCOTT.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR BENTON-
BUCHANAN-DES MOINES-HENRY IA-IOWA-JEFFERSON-JOHNSON-KEOKUK-
LEE-LOUISA-MUSCATINE-VAN BUREN-WASHINGTON.
WINTER STORM WARNING UNTIL MIDNIGHT CST TONIGHT FOR CEDAR-
DELAWARE-DUBUQUE-JONES-LINN.
IL...WINTER STORM WARNING UNTIL 3 AM CST FRIDAY FOR CARROLL-JO
DAVIESS-ROCK ISLAND-STEPHENSON-WHITESIDE.
WINTER WEATHER ADVISORY UNTIL 3 AM CST FRIDAY FOR BUREAU-HANCOCK-
HENDERSON-HENRY IL-MCDONOUGH-MERCER-PUTNAM-WARREN.
MO...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR CLARK-
SCOTLAND.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
300 PM CST WED JAN 11 2012
.SYNOPSIS...
12Z UA ANALYSIS HAD AN 850MB POLAR FRONT RUNNING FROM A LOW NEAR
THE MINNESOTA ARROWHEAD SOUTHWEST INTO NEW MEXICO. A CUT OFF LOW
WAS OVER THE TENNESSEE VALLEY DRIFTING TO THE NORTHEAST. SATELLITE
AND RADAR TRENDS THROUGH EARLY AFTERNOON SHOW CLOUDS MOVING EAST
ACROSS IOWA WITH A BAND OF SNOW FROM MINNESOTA INTO WESTERN IOWA
AND EASTERN NEBRASKA.
18Z SFC ANALYSIS HAD A SERIES OF LOW IN NORTHERN WISCONSIN WITH A
PRE-FRONTAL TROF THROUGH EASTERN IOWA AND INTO CENTRAL OKLAHOMA.
THE POLAR FRONT RAN FROM JUST EAST OF KDLH...TO KMCI...TO KCDS.
DEW POINTS ALONG THE FRONT WERE IN THE 30S WITH 20S OUT AHEAD OF
IT. BEHIND THE POLAR FRONT...DEW POINTS QUICKLY DROPPED OFF INTO
THE 20S AND TEENS.
&&
.SHORT TERM...TONIGHT AND THURSDAY
COMPRESSIONAL HEATING AHEAD OF THE POLAR FRONT HAS RESULTED IN
RECORD HIGHS BEING EITHER TIED OR BROKEN TODAY. SEE THE CLIMATE
SECTION BELOW FOR SPECIFIC RECORDS.
THE WINTER STORM WATCH HAS BEEN UPGRADED TO A WINTER WEATHER ADVISORY.
BASED ON THE SYSTEM BEING A BIT SLOWER AND DIGGING A LITTLE
FURTHER TO THE SOUTH/WEST...THE START TIME OF SOME ADVISORY
HEADLINES FOR AREAS ALONG/EAST OF THE MISSISSIPPI HAVE BEEN PUSHED
BACK TO MIDNIGHT.
THE POLAR FRONT SHOULD REACH THE BULK OF THE MISSISSIPPI RIVER
RIGHT AROUND SUNSET AND SHOULD EXIT THE EASTERN CWFA JUST BEFORE
MIDNIGHT. SINCE THE SYSTEM CONTINUES TO SHOW SOME NON-LINEARITY
ASPECTS TO IT...THE RUC HAS BE VERY USEFUL IN THE IMMEDIATE SHORT
TERM.
PER THE RUC...CONDENSATION PRESSURE DEFICITS START COLLAPSING THIS
EVENING IN THE FAR WESTERN CWFA AS THE FORCING INCREASES. BY 9
PM...A BAND OF SNOW WILL BE OVER ROUGHLY THE WESTERN THIRD TO 40
PERCENT OF THE CWFA. STARTING AROUND 9 PM...THE RUC INDICATES A
DEFORMATION ZONE WILL BEGIN DEVELOPING OVER EASTERN IOWA AS THE
UPPER LEVEL SYSTEM STRENGTHENS. BY MIDNIGHT...SNOW WILL BE WIDESPREAD
GENERALLY WEST OF A KDBQ TO KEOK LINE.
AFTER MIDNIGHT...THE OVERALL FORCING CONTINUES TO STRENGTHEN AS
THE DEFORMATION ZONE BECOMES FULLY EVOLVED. BY SUNRISE...SNOW
SHOULD BE WIDESPREAD ACROSS THE ENTIRE CWFA.
SNOWFALL AMOUNTS TONIGHT SHOULD RANGE FROM 0.5 INCHES IN THE
EXTREME EASTERN CWFA TO 2.5 INCHES IN THE FAR WESTERN CWFA.
SNOW/RAIN RATIOS WILL INITIALLY START OUT CLOSE TO
CLIMATOLOGY...OR ROUGHLY 13 TO 1 AND WILL INCREASE LATER TONIGHT
INTO THURSDAY.
BASED ON THE OVERALL FORCING...THE PERIOD FROM MIDNIGHT TO ABOUT NOON
THURSDAY WILL BE WHEN A MAJORITY OF THE SNOW WILL FALL.
ON THURSDAY...SNOW WILL BE WIDESPREAD ACROSS THE AREA DURING THE
MORNING HOURS WITH THE DEFORMATION ZONE OVER THE AREA. DURING THE
AFTERNOON THE SNOW INTENSITY WILL DECREASE ACROSS THE WESTERN CWFA
WHILE CONTINUING IN THE EASTERN PARTS.
SNOW AMOUNTS ON THURSDAY WILL BE AN ADDITIONAL 1 TO 4 INCHES WITH
A GRADIENT RUNNING FROM WEST TO EAST.
SINCE THE SNOW WILL BE QUITE DRY...CONSIDERABLE DRIFTING WILL BE
SEEN...ESPECIALLY IN RURAL AND OPEN AREAS. WINDS SHOULD BE 20 TO
30 MPH WITH GUSTS TO AROUND 35 MPH. WHILE BLOWING SNOW MAY
OCCUR...IT SHOULD BE PATCHY IN NATURE IN THE RURAL AREAS.
..08..
.LONG TERM...THURSDAY NIGHT THROUGH NEXT WEDNESDAY
ACTIVE PATTERN BUT NO SIGNIFICANT SYSTEMS SUGGESTED ATTM.
SNOW IS EXPECTED TO TAPER TO FLURRIES THU EVE WITH LITTLE ADDITIONAL
ACCUMS. LINGERING GUSTY WINDS MAY PRODUCE SOME DRIFTING AND POSSIBLY
PATCHY BLOWING SNOW.
FRI-FRI NGT... WINDS GENERALLY BRISK AT 10-20 MPH DURING DAY WITH
CLOUDS AND FLURRIES POSSIBLE WITH ADDITIONAL ENERGY DIGGING DOWN
BACKSIDE OF DEPARTING STORM SYSTEM. HIGHS ONLY RECOVERING IN TEENS
AND 20S. SOME CLEARING FRI NGT BUT APPEARS SHORT LIVED AS WARM
ADVECTION MID/HIGH CLOUDS QUICKLY ON HEELS OF ANY CLEARING ATTENDANT
TO NEXT APPROACHING SHORTWAVE /CLIPPER SYSTEM/. CLOUD TRENDS MAKE
MIN TEMP FCST CHALLENGING. ANTICIPATE WINDS TO DIE OFF IN EVE AND AT
LEAST PARTIAL CLEARING FOR WIDESPREAD SINGLE DIGITS... POSSIBLY AT
OR BELOW ZERO IN SOME AREAS N/E... BEFORE CLOUDS INCREASE.
SAT-SAT NGT... CLIPPER SYSTEM EXPECTED TO PASS MAINLY DURING DAY. JET
STRUCTURE NOT THAT IMPRESSIVE AND MOISTURE LACKING SO FAVOR THE
WEAKER HI-RES ECMWF FOR MAINLY FLURRIES WITH CHC OF -SN.
SUN-SUN NGT... GENERALLY DRY WITH MODERATING TEMPS AS HEIGHTS BUILD
ALOFT WITH CHALLENGE BEING RESIDUAL SNOW COVER AND IMPACT ON TEMPS.
MAY SEE NON-DIURNAL TREND AT NGT WITH TEMPS SLOWLY RISING WITH
CONTINUED LOW LEVEL WARM ADVECTION.
MON-WED... NEXT FRONT TO PASS MON-MON NGT WITH CHC OF PCPN. MODELS
SHOWING SUFFICIENT WARMING AHEAD FOR BULK OF PCPN TO BE RAIN BUT
AS COLDER AIR DEEPENS MON NGT IN WAKE OF FRONTAL PASSAGE COULD SEE
MIX OR BRIEF CHG TO -SN. TUE-WED LOOK TO BE MAINLY DRY AND COLDER.
..05..
&&
.AVIATION...
VFR WX WILL CONTINUE UP UNTIL ROUGHLY 00Z/12. BTWN 00Z/12 AND
06Z/12 MVFR CIGS WL DLVP AT ALL TAF SITES WITH SN DVLPG IN THE
03Z/12 TO 07Z/12 TIME FRAME. CONDITIONS WILL DETERIORATE RAPIDLY
FROM 05Z/12 TO 10Z/12 WITH POTENTIAL IFR CONDITIONS. INCREASING
WINDS AND LOWERING CIGS MAY RESULT IN BRIEF PERIODS OF LIFR
CONDITIONS AFT 09Z/12.
..08..
&&
.CLIMATE...
RECORD HIGHS FOR JANUARY 11...
RECORD HIGHS WERE TIED OR BROKEN TODAY
MOLINE.........56 IN 1880
CEDAR RAPIDS...51 IN 2002 AND OTHER YEARS
DUBUQUE........50 IN 1980
BURLINGTON.....55 IN 1980
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 6 AM CST FRIDAY
FOR CLINTON-JACKSON-SCOTT.
WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO MIDNIGHT CST
THURSDAY NIGHT FOR BENTON-BUCHANAN-CEDAR-DELAWARE-DES
MOINES-DUBUQUE-HENRY IA-IOWA-JEFFERSON-JOHNSON-JONES-KEOKUK-
LEE-LINN-LOUISA-MUSCATINE-VAN BUREN-WASHINGTON.
IL...WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 6 AM CST FRIDAY
FOR BUREAU-CARROLL-HANCOCK-HENDERSON-HENRY IL-JO DAVIESS-
MCDONOUGH-MERCER-PUTNAM-ROCK ISLAND-STEPHENSON-WARREN-
WHITESIDE.
MO...WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO MIDNIGHT CST
THURSDAY NIGHT FOR CLARK-SCOTLAND.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
203 PM CST WED JAN 11 2012
.SYNOPSIS...
12Z RAOB PLOT ANALYSIS INDICATES A LARGE TROUGH PUSHING ACROSS THE ROCKIES
AND INTO THE NORTHERN PLAINS. THIS FEATURE HAS USHERED IN A COLD FRONT
EARLY THIS MORNING ACROSS SOUTHWEST KANSAS. AS OF 18Z, THIS FRONT IS
STILL MOVING ACROSS OKLAHOMA. WINDS WERE STRONG BEHIND THE FRONT WITH
MANY OBSERVATION SITES ACROSS WESTERN KANSAS REPORTING WINDS AROUND
30 KT.
&&
.DISCUSSION...
DAYS 1-2...
TONIGHT:
SHORT TERM FOCUS IS WINDS. HAVE UPDATED THE WIND ADVISORY FOR THE ENTIRE
REGION AS AWOS SITES ACROSS FAR WESTERN KANSAS HAVE BEEN AT WIND ADVISORY
CRITERIA EARLIER. HRRR AND NAM SHOW THAT WINDS WILL QUICKLY TAPER TOWARDS
6 PM CST. SECOND SHORT TERM FOCUS IS IF WE WILL SEE PRECIPITATION. THE
NAM HAS VERY LIGHT QPF ACROSS CENTRAL KANSAS TONIGHT. HRRR ALSO INDICATES
LIGHT COMPOSITE REFLECTIVITY FORECAST SO HAVE PUT 20 POPS ACROSS THE
NORTHEAST/NORTH. ELSEWHERE, WILL KEEP AROUND 10 PERCENT WITH FLURRIES. THIS
ACTIVITY WILL DIMINISH THIS EVENING. OVERNIGHT LOWS WILL BE ON THE COLD
SIDE AS WINDS WEAKEN AND SKIES CLEAR. WINDS WILL NOT COMPLETELY CALM
SO DID NOT GET TOO CARRIED AWAY WITH LOWS.
THURSDAY/THURSDAY NIGHT:
ANOTHER WINDY DAY LOOKS LIKELY ACROSS SOUTHWEST KANSAS TOMORROW. THIS
IS IN ASSOCIATION WITH A TIGHT PRESSURE GRADIENT REMAINING OVER THE
AREA. HAVE INCREASED WINDS IN THE GRIDS IN THE 20 TO 30 MPH RANGE BUT
KEPT VALUES/GUSTS BELOW WIND ADVISORY CRITERIA. INSTEAD OF HAVING TWO
WIND ADVISORIES OUT, WHICH COULD BE CONFUSING...I WILL LET THE MID SHIFT
DECIDE IF WE NEED A WIND ADVISORY OR NOT. TOMORROWS HIGHS WILL BE IN
THE 30S DEG F. OVERNIGHT LOWS ARE EXPECTED TO BE IN THE TEENS DEG F.
FRIDAY:
KANSAS WILL BE IN NORTHWEST FLOW ALOFT WHICH FAVORS A DRY FORECAST.
WILL KEEP POPS AT ZERO FRIDAY. COULD SEE SOME DOWNSLOPE WESTERLY WINDS
FRIDAY SO HAVE WARMED HIGHS UP A BIT. 850 HPA TEMPERATURES WARM UP INTO
THE LOWER SINGLE POSITIVE DIGITS DEG C, SO WE COULD SEE SOME MIXING
TO 40S DEG F AT THE SURFACE.
DAYS 3-7...
THE MID TO UPPER-LEVEL FLOW WILL GRADUALLY TRANSITION FROM
NORTHWESTERLY TO WEST-SOUTHWESTERLY FROM FRIDAY NIGHT INTO SUNDAY.
THUS, SURFACE PRESSURES WILL FALL IN THE LEE OF THE ROCKIES ALONG
WITH SOME WEAK LOW-LEVEL DOWNSLOPE FLOW. HIGH TEMPERATURES WILL
MODIFY INTO THE MID 50S BY SATURDAY AND 55 TO 60 BY SUNDAY.
A SHORTWAVE TROUGH WILL PROGRESS IN MAINLY ZONAL FLOW ACROSS THE
CENTRAL AND NORTHERN PLAINS BY MONDAY AND MONDAY NIGHT. THIS WILL
BRING SOME COLDER AIR INTO WESTERN KANSAS. SO AFTER A FAIRLY MILD
DAY MONDAY (50S TO LOWER 60S) JUST IN ADVANCE OF THE FRONT, HIGHS
WILL FALL INTO THE 30S OR LOWER 40S BY TUESDAY. NO PRECIPITATION CAN
BE EXPECTED IN THIS ZONAL PATTERN.
ANOTHER WARMING TREND IS EXPECTED BY JANUARY 18-19TH WITH HIGHS
POSSIBLY REACHING TO NEAR 70F IN A GENERALLY ZONAL MID TO UPPER-LEVEL
FLOW REGIME WITH LEE-TROUGHING AT LOW-LEVELS. HOWEVER, AS IS OFTEN
THE CASE IN ZONAL REGIMES, THERE WILL BE A SHARP TEMPERATURE
GRADIENT BETWEEN DOWNSLOPE FLOW OVER THE SOUTHERN AND CENTRAL PLAINS
AND ARCTIC AIR OVER THE NORTHERN PLAINS OR SOUTHERN CANADA. ANY
SHORTWAVE TROUGH TRAVERSING THE FLOW COULD RESULT IN ANOTHER SURGE
OF COLD AIR. THE ECMWF IS ADVERTISING ANOTHER SUCH COOLDOWN BY
JANUARY 20-21ST. NO SIGNIFICANT PRECIPITATION IS EXPECTED THROUGH
JANUARY 21ST.
&&
.AVIATION...
FOR THE 18Z TAF ISSUANCE...
WINDS WILL REMAIN SUSTAINED AT 30 KTS WITH GUSTS TO 40 KTS THOUGH
23Z AS STRONG VERTICAL MIXING BRINGS DOWN THE HIGHER WINDS. BY 00Z
THE WINDS WILL SUBSIDE TO 15TS AS THE PRESSURE GRADIENT AND VERTICAL
MIXING WEAKEN. SKIES WILL VARY BETWEEN SCT/BKN025 AND THEN CLEAR BY
00Z. A FEW FLURRIES ARE POSSIBLE AT KHYS JUST AHEAD OF AN
UPPER-LEVEL TROUGH THROUGH 23Z, BUT THIS SHOULD NOT BE ENOUGH TO
REDUCE VISIBILITIES BELOW 5SM.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 12 35 14 46 / 10 0 0 0
GCK 11 35 12 47 / 10 0 0 0
EHA 11 37 15 48 / 10 0 0 0
LBL 11 36 15 48 / 10 0 0 0
HYS 11 33 11 46 / 10 0 0 0
P28 17 37 15 46 / 10 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 6 PM CST /5 PM MST/ THIS EVENING FOR KSZ030-
031-043>046-061>066-074>081-084>090.
&&
$$
AREA FORECAST DISCUSSION
NWS GAYLORD MI
922 PM EST THU JAN 12 2012
.SYNOPSIS.../ISSUED AT 350 PM/
DEEP LOW PRESSURE WILL SLOWLY CREEP NORTHWARD INTO LAKE HURON
TONIGHT. SNOW WILL SPREAD OVER ALL OF NORTHERN MICHIGAN THROUGH
TONIGHT...AND THEN TAPER OFF FRIDAY. INCREASING NORTH TO NORTHEAST
WINDS...WILL TRANSPORT MUCH COLDER TEMPERATURES INTO THE REGION...
AND ALSO LEAD TO CONSIDERABLE BLOWING AND DRIFTING SNOW. A FEW LIGHT
SNOW SHOWERS AND FLURRIES...WILL LINGER INTO SATURDAY AND SUNDAY...
BUT WITH NO ADDITIONAL ACCUMULATION. TEMPERATURES WILL TURN MILDER
EARLY NEXT WEEK...AS THE NEXT ORGANIZED SYSTEM MOVES THROUGH.
HALBLAUB
&&
.SHORT TERM.../ISSUED AT 922 PM/...TONIGHT
UPDATE: GOING FCST IS WELL ON TRACK AT THIS POINT...WITH A WIDE
SWATH OF MAINLY LIGHT TO OCCASIONALLY MODERATE SNOW PINWHEELING
OVERHEAD. SAID SNOW SHIELD IS CURRENTLY BEGING DRIVEN BY ELONGATED
AXIS OF WARM ADVECTION ASCENT WITHIN PRONOUNCED TROWAL FEATURE
WRAPPING NORTH OF CLOSED 850-700MB LOWS NEARING SAGINAW BAY. ALSO
HELPING IS INCREASED DEFORMATION DYNAMICS DEVELOPING OVERHEAD...
WHICH SHOULD EASILY MAINTAIN CURRENT SNOW SHIELD MUCH OF THE REST OF
THE NIGHT AS TROWAL FORCING WEAKENS. LATEST RUC FCST RAOBS COMBINED
WITH 7-8PM REPORTS (THANKS TO ALL THE SPOTTERS!) SHOW RATIOS ARE
NOTHING SPECIAL...GENERALLY AROUND 10/12 TO 1...SAVE FOR EARLIER
BETTER RATIOS ACROSS THE HIGHER TERRAIN...IN LINE WITH PROGGED
BETTER LIFT THROUGH THE DGZ...WHICH HAS SINCE FADED. SNOWFALL TOTALS
THUS FAR ARE GENERALLY 1 TO 3 INCHES ACROSS MUCH OF NORTHERN
LOWER...MAINLY LESS THAN AN INCH NORTH OF THE STRAITS...WHERE
EARLIER WEDGE OF LOW LEVEL DRY AIR HELD SNOW AT BAY UNTIL ABOUT 00Z.
HEADING THROUGH THE NIGHT...GOING HEADLINES LOOK JUST FINE...THOUGH
STARTING TO FEEL THE CURRENT WARNING MAY BE A BIT OF AN OVERKILL.
STILL...WILL GIVE IT A CHANCE WITH SOME POTENTIAL FOR LAKE
ENHANCEMENT TO KICK IN AFTER 06Z WITH INCREASING INFLUX OF MUCH
COLDER AIR (H85 TEMPS TUMBLING DOWN TOWARD -12C). IN GENERAL...HAVE
LOWERED CURRENT FCST AMOUNTS JUST A TAD IN MANY AREAS THROUGH THE
NIGHT...ESPECIALLY CLOSE TO SAGINAW BAY WHERE INCOMING DRY SLOT MAY
MAKE AN APPEARANCE. STILL LOOKING LIKE ANOTHER GENERAL 2 TO 4 INCHES
WILL FALL OVERNIGHT PER RADAR EXTRAPOLATION AND EXPECTED ONLY MODEST
RATIOS OF 15 TO 1 AT BEST...WELL IN LINE WITH CURRENT ADVISORY
(AGAIN...THE WARNING MAY BE A BIT OVERDONE) AND EARLIER
EXPECTATIONS. HAVE REWORKED DIURNAL TEMPS TO SOME DEGREE TO SHOW A
SLOWER COOLING TREND (TEMPS STILL IN THE LOWER 30S IN MANY AREAS)...
THOUGH ONCE COLD ADVECTION KICKS IN TOWARD 06Z...READINGS WILL
QUICKLY TANK THROUGH THE TEENS AND 20S IN ALL AREAS.
LAWRENCE
EARLIER EXCELLENT DISCUSSION FOLLOWS:
WINTER EVENT PLUGGING ALONG JUST FINE. LOW PRESSURE CONTINUES TO
ORGANIZE AND STRENGTHEN OVER THE THUMB OF LOWER MICHIGAN...A
FAVORABLE LOCATION FOR DECENT SNOW AMOUNTS FOR MANISTEE THROUGH
GAYLORD AND ROGERS CITY IN NRN LOWER. (AXIS OF BEST SYNOPTIC
SNOWS). THE PARENT UPPER TROUGH WHICH CLOSED OFF...IS SWEEPING
ACROSS SRN IL ATTM...WHILE +100KT UPPER JET AND LEFT EXIT DYNAMICS
AND THE DEEP LAYER -DIVQ IS AIDING THE AREAS THAT WERE ALREADY
SNOWING...WHILE ALSO ERODING THE WEDGE OF DRY AIR ACROSS NW LOWER.
SNOWS ARE STARTING TO BREAK OUT THERE. IN ADDITION SOUNDING DATA
SUPPORTING LARGE DENDRITES RIGHT NOW WITH LIFT MAXIMIZING IN THE
DGZ. FOG ERODES QUICKLY WITH ONSET OF THE SNOWS. STILL QUIET IN
EASTERN UPPER. ONLY A FEW SPOTS HAVE RAIN MIXED IN WITH THE
SNOW...PRIMARILY ON THE COASTS...AND WHERE THE SNOW REMAINS LIGHT.
EVEN NE LOWER NEAR THE BAY HAS BEEN PRIMARILY SNOW...DUE TO BETTER
PRECIPITATION INTENSITY.
THROUGH THE NIGHT...MODEST TO STRONG FORCING AND JET DYNAMICS
CONTINUE TO OVERSPREAD TROWAL THROUGH THE EVENING...YET THE LIFT
MAXIMIZED IN THE DGZ WILL FALL OFF EARLY THIS EVENING WHILE THE
LOW PRESSURE SHIFTS INTO GEORGIAN BAY. THERE IS LITTLE TO NO HELP
WITH THE LAKES THROUGH THIS TIME...SO PURELY A SYNOPTIC SNOWFALL.
THIS IS NOT A PROBLEM IN PICKING UP A SOLID 3 TO 5 INCHES THROUGH
THIS EVENING IN NRN LOWER FOR AREAS MAINLY ALONG AND WEST OF I75.
AS THE LOW PRESSURE PULLS OFF TO THE EAST...THE STRONGER DYNAMICS
EXIT AND WE TURN TO MORE OF A LAKE ENHANCED SNOWFALL WITHIN
DEFORMATION ZONE ALOFT. THE COLDEST ADVECTION WILL BE WITHIN
STRENGTHENING LOW LEVEL NORTH TO NNW FLOW ACROSS NW LOWER.
INVERSION HEIGHTS NEVER REALLY GET PAST 4500 FEET...BUT CAN SEE 2
INCHES OF LAKE HELP ADDING TO ANOTHER INCH OR SO FROM DEFORMATION
SNOWS. THUS...IN THE WARNING COUNTIES...CAN SEE UP TO 6 INCHES
FALLING THROUGH TONIGHT. THE CYCLONIC CONVERGENCE IS SO GOOD THAT
WINDS ARE MORE NNE OUT OF ONTARIO...WHICH VIRTUALLY SHUTS OFF
EASTERN UPPER FROM ANY LAKE HELP (NO FETCH). ANYWAYS...SYNOPTIC
DEFORMATION SNOWS RANGING FROM AN INCH SW TO 2 INCHES DRUMMOND
ISLAND OVERNIGHT WILL RESULT IN SNOWFALL TOTALS OF 4 TO 6 INCHES
FOR MOST OF NRN MICHIGAN THROUGH TONIGHT FOR SOLID ADVISORY
CRITERIA. DID EXPAND ADVISORIES TO INCLUDE ROSCOMMON COUNTY TO
ALPENA COUNTY. THE LEAST SNOW AMOUNTS WILL FALL IN WESTERN
CHIP/MACK OF EASTERN UPPER AWAY FROM NEST DYNAMICS AND
DEFORMATION/LAKE EFFECT...AS WELL AS COUNTIES NEAR SAG BAY...WHERE
ALSO THERE WILL BE A BIT OF DRYING ALOFT (DRY SLOT JUST SOUTHEAST
OF THERE). CAN SEE 1-3 INCHES IN THESE AREAS. WILL ALSO BE SOME
AREAS OF BLOWING SNOW DEVELOPING THROUGH THE NIGHT AS TIGHTER
PRESSURE GRADIENT SLIDES IN ON BACKSIDE OF THE DEPARTING LOW. AT
NIGHT...WORST OF THE BLOWING SNOW WILL BE ALONG THE LAKE MICHIGAN
COAST AND EVEN WHITEFISH BAY (IF THE SNOW FALLS MORE DECENTLY THAN
CURRENT THINKING FOR THERE). THE COLD ADVECTION WILL RESULT IN
LOWS FALLING INTO THE TEENS NORTH TO THE LOWER 20S SOUTH.
SMD
&&
.LONG TERM.../ISSUED AT 350 PM/...FRIDAY AND BEYOND
FRIDAY...DEFORMATION SYNOPTIC SNOWS WILL BE ENDING IN THE MORNING
AS LOW PRESSURE CONTINUES TO LIFT FURTHER EAST OF US. THE DEEPER
MOISTURE WILL BE ON THE WAY OUT AS WELL...HOWEVER THERE WILL BE A
PERIOD OF TIME WHERE THE NNW LAKE EFFECT AREAS WILL SEE MODERATE
SNOWS PERSISTING INTO THE MORNING. THUS ALL WARNINGS/ADVISORIES
WILL HOLD THROUGH THE DAY. DURING THE AFTERNOON HOWEVER...THERE
WILL BE SOME DRY AIR DIVING DOWN FROM THE NORTH. THERE IS STILL
GOOD CYCLONIC CONVERGENCE WHILE THE DRY AIR ARRIVES...AND WITH
LAKE EFFECT SUSTAINING ITSELF LONGER THAN TYPICALLY
EXPECTED...WILL KEEP SNOW SHOWERS GOING SOUTH AND WEST OF GTV BAY
THROUGH THE AFTERNOON WITH TOTAL ACCUMS OF ANOTHER 1 TO 3 INCHES.
THIS IS NOT TRUE FOR EASTERN UPPER...WHERE WINDS REMAIN OUT OF THE
NORTH. MAYBE FAR WESTERN CHIP/MACK CAN SEE SOME LIGHT SNOW
SHOWERS...BUT DOWNSLOPING FLOW FROM ONTARIO WILL LIKELY TAKE AREAS
ALONG AND EAST OF -I75 THERE...PARTLY CLOUDY (MOSTLY SUNNY?). THE
DEPARTING DEFORMATION/DEEPER MOISTURE WILL GIVE UP TO ANOTHER INCH
FOR ALL OTHER AREAS. TEMPERATURES WILL REMAIN IN THE TEENS NORTH
TO LOWER 20S SOUTH THROUGH THE DAY..AS THEY EITHER BE STEADY OR
SLOWLY FALLING IN STRONG COLD ADVECTION. WINTER IS HERE.
LATER PERIODS...
DISCUSSION...QUICK INTRUSION OF MODIFIED ARCTIC AIR LATE
THIS WEEK WILL BE JUST THAT...QUICK...WITH WELL AGREED UPON MODEL
PROGS SUGGESTING A RAPID TRANSITION TO QUASI-ZONAL FLOW REGIME BY
LATER THIS WEEKEND...TRENDING TOWARD DEEPENING WESTERN TROUGHING
EARLY NEXT WEEK. LARGE SCALE INDICES/FEATURES SUPPORT SUCH...WITH
FAR EAST DISPLACED ATLANTIC BLOCKING (MAINTENANCE OF WEAKLY
POSITIVE NAO) AND BUILDING ALEUTIAN ISLANDS/BERING SEA RIDGING
(ALLOWING ENERGY TO CUT BACK SOUTHWEST ON ITS DOWNSTREAM
SIDE...DEVELOPING THE WESTERN TROUGH). PATTERN ALSO EXPECTED TO BE
A RATHER ACTIVE ONE...BOTH WITH PRECIPITATION AND TEMPERATURE
TRENDS...AS ENERGY EJECTING OUT OF THIS WESTERN TROUGH INTERACTS
WITH TIGHTENING NORTHERN CONUS BAROCLINIC ZONE. FORECAST CONCERNS
INITIALLY CENTER ON LINGERING LIGHT LAKE INDUCED SNOW POTENTIAL IN
RETREATING COLD AIRMASS THIS WEEKEND...WITH LATER CONCERNS FOCUSED
ON THE TEMPERATURE ROLLER COASTER RIDE AND POSSIBLE EARLY WEEK
STORM SYSTEM.
SYNOPTIC EFFECTS OF CURRENT WINTER STORM WILL END QUICKLY FRIDAY
EVENING...LEAVING BEHIND MORE OF A PURE LAKE INDUCED SIGNATURE FOR
SNOW GENERATION. REMNANT SYNOPTIC MOISTURE SHOULD CONTINUE TO HELP
GENERATE LAKE INDUCED SNOWS IN FAVORED NNW FLOW AREAS EARLY FRIDAY
EVENING...WITH QUICKLY WANING INTENSITY OVERNIGHT AS MOISTURE
DEPARTS AND INVERSION LEVELS STAY AROUND 850MBS. SIMPLE OVER-WATER
INSTABILITY (DELTA T/S IN THE LOWER 20S) AND IN-CLOUD OMEGA CENTERED
IN THE DGZ FAVOR AT LEAST SOME MINOR ACCUMULATIONS THROUGH THE
OVERNIGHT...WITH PERHAPS AN INCH TO INCH AND A HALF FOCUSED JUST
WEST AND SOUTHWEST OF TRAVERSE CITY. INCREASINGLY WEAK FLOW LIKELY
TO LEAD TO SOME LAND BREEZE DISRUPTION BY SATURDAY MORNING...
FOCUSING "BEST" SNOWS TO ALONG THE LAKE MICHIGAN SHORELINE. SAME
LIGHT FLOW SUPPORTS GOOD NORTHEAST DRAINAGE FLOW OFF THE ONTARIO
PLATEAU NORTH OF THE SOO...WITH SHOULD PUSH LAKE SUPERIOR SNOWS WEST
OF WHITEFISH POINT BY EARLY SATURDAY MORNING (FRIDAY EVENING NORTH
TO NORTHEAST FLOW ALSO NOT CONDUCIVE FOR HEAVY LAKE SNOWS). HAVE
GONE AHEAD A CUT SNOW COVERAGE AND AMOUNTS SIGNIFICANTLY FRIDAY
NIGHT ACROSS EASTERN UPPER (JUST TRACE AMOUNTS). WEAK LAKE SNOWS TO
CONTINUE INTO SATURDAY...ALTHOUGH LIGHT WINDS SURE TO PLAY HAVOC
WITH EXACT PLACEMENT OF ACTIVITY. GROWING EVIDENCE OF SOME LAKE
INDUCED MESOLOW FORMATION OVER NORTHERN LAKE MICHIGAN/NORTHERN GRAND
TRAVERSE BAY LATE FRIDAY NIGHT INTO SATURDAY MORNING...WITH FOCUSED
CONVERGENCE CONTINUING THE LIGHT SNOW SHOWER THREAT ALONG THE
IMMEDIATE LAKE MICHIGAN SHORELINE. SNOW AMOUNTS SHOULD BE WELL UNDER
AN INCH...UNLESS CONVERGENCE AXIS GETS TOO OUT OF HAND (SURE HAVE
SEEN THAT BEFORE). TEMPERATURES DEPENDENT ON CLOUD COVERAGE AND SNOW
ACTIVITY...WITH PATTERN RECOGNITION OF GOOD DRAINAGE FLOW
DEVELOPMENT SUPPORTING GUIDANCE TRENDS OF DROPPING READINGS WELL
BELOW ZERO OVER EAST SECTIONS OF EASTERN UPPER...AND NEAR ZERO
READING IN THE FAVORED COLD LOCATIONS OF NORTHEAST LOWER FOR FRIDAY
NIGHT. ONE OF THE COLDEST AIR MASSES OF THE SEASON FOR SATURDAY...
WITH DAYTIME HIGHS GENERALLY STUCK IN THE TEENS.
NEBULOUS FORECAST CONTINUES THROUGH THE REMAINDER OF THE
WEEKEND...WITH GUIDANCE STRUGGLING WITH WEAK CLIPPER TYPE SYSTEM
SLATED TO CROSS THROUGH THE REGION. GFS THE MOST AGGRESSIVE BY
FAR...BRING A DECENT SURFACE LOW THROUGH THE STRAITS SUNDAY MORNING.
OTHER GUIDANCE NOT NEARLY SO AMBITIOUS...WITH JUST A DIFFUSE
RELAXATION IN THE PRESSURE FIELDS AND MUCH LESS MOISTURE. MID LEVEL
SUPPORT SIDES WITH THE LESS AGGRESSIVE SCENARIOS (AS DOES
MULTI-PERIOD TRENDS)...WHICH INHERITED FORECAST ALREADY SUPPORTS.
LAKE SNOWS MAY GET SOMEWHAT OF A BOOST TOWARDS SUNDAY MORNING...WITH
INCREASING MOISTURE PROGS AND DEVELOPING LIGHT SOUTHWEST FLOW
HELPING THE MOISTURE FLUX FROM THE WATERS. COMBINE THIS WITH
TEMPERATURES STILL PLENTY COLD ENOUGH (850MB TEMPERATURES IN THE
NEGATIVE TEENS)...AND AT LEAST SOME LIGHT SNOW SHOWERS SHOULD MOVE
INTO MACKINAC COUNTY IN FAVORED SOUTHWEST FLOW AREAS.
OTHERWISE...WILL KEEP OTHER AREAS DRY.
AS MENTIONED EARLIER...A RATHER ACTIVITY PATTERN UNFOLDING FOR NEXT
WEEK AS ENERGY DIGS OUT WEST AND BAROCLINIC ZONE TIGHTENS ACROSS THE
NORTHERN CONUS. INITIAL WARM SURGE EXPECTED TO OVERSPREAD NORTHERN
MICHIGAN QUICKLY MONDAY AS SOUTHWEST FLOW STRENGTHENS ON DOWNSTREAM
SIDE OF DEPARTING HIGH PRESSURE. SUBTLE WEAK LEAD WAVE AND MOISTURE
FLUX IN WAA REGIME MAY KICK OFF A LIGHT WINTRY MIX MONDAY (RAIN/SNOW
SOUTH...ALL SNOW NORTH). BIGGER CONCERN IS POSSIBLE LOW DEVELOPMENT
AND INTENSE FGEN SIGNATURE ALONG SLOWING COLD FRONT AS PRIMARY WAVE
EJECTS OUT OF THE PLAINS MONDAY NIGHT INTO EARLY TUESDAY. PLENTY OF
HIGH RES GUIDANCE AND LOW RES ENSEMBLE SUPPORT FOR THE
ABOVE...ALTHOUGH WITH PLENTY OF UNCERTAINTY ON THE TRACK OF THE
SURFACE LOW. WILL KEEP HIGH CHANCE SNOW WORDING MONDAY NIGHT INTO
TUESDAY TO ACCOUNT FOR REMAINING UNCERTAINTY. WILL SAY SOME OF THE
GFS ENSEMBLES ARE AWFULLY STRONG WITH THIS SYSTEM (SUB 990MBS)...AND
WITH THE TENDENCY FOR THESE PACIFIC WAVES TO END UP STRONGER THAN
INITIALLY PROGGED DOES LEND AT LEAST SOME CREDENCE TO THESE STRONGER
SOLUTIONS. DEFINITELY SOMETHING TO WATCH WITH MOUNTING EVIDENCE OF A
GREAT WESTERN GULF OF MEXICO MOISTURE CONNECTION. WILL CONTINUE TO
HIGHLIGHT THIS POTENTIAL IN THE AFTERNOON RENDITION OF THE HAZARDOUS
WEATHER OUTLOOK. A GLANCING BLOW OF VERY COLD ARCTIC AIR TO FOLLOW
THIS SYSTEM TUESDAY NIGHT INTO THURSDAY...WITH 850MB TEMPERATURES
FALLING TO NEAR -20C. MORE THAN COLD ENOUGH TO START THE LAKE
MACHINE...ESPECIALLY IN FAVORED NORTHWEST FLOW AREAS. HIGH
TEMPERATURES BACK IN THE TEENS BOTH WEDNESDAY AND THURSDAY.
MSB
&&
.MARINE.../ISSUED AT 350 PM/
WINDS WILL BE INCREASING THROUGH TONIGHT FROM WEST TO EAST ACROSS
THE GREAT LAKES AS TIGHTER PRESSURE GRADIENT SLIDES IN BEHIND A
DEPARTING LOW PRESSURE SYSTEM THAT WILL BE PRODUCING MODERATE TO
HEAVY SNOWS ACROSS THE REGION. GALES STILL LOOK REAL GOOD FOR
SLEEPING BEAR POINT SOUTHWARD...BUT REMAIN JUST SHY ALL OTHER
AREAS INTO TOMORROW. THUS...ALL HEADLINES WILL HOLD AS IS. WAVE
ACTION WILL CONTINUE TO BE AN ISSUE INTO FRIDAY NIGHT.
SMD
NORTHWEST WINDS EXPECTED TO SUBSIDE RATHER QUICKLY FRIDAY
EVENING AS HIGH PRESSURE BUILDS INTO THE AREA. LIGHT WINDS WILL
CONTINUE THROUGH AT LEAST SATURDAY NIGHT...WITH SOUTHWEST FLOW
BEGINNING TO STRENGTHEN BY LATER SUNDAY. SOUTH WINDS...AT TIMES
GUSTY...WILL CONTINUE INTO EARLY NEXT WORK WEEK AHEAD OF AN
APPROACHING COLD FRONT.
MSB
&&
.AVIATION.../ISSUED AT 622 PM/...VALID FOR 00Z TAFS
WIDESPREAD IFR CEILINGS AND VISBYS ARE EXPECTED THROUGH THE NIGHT
AS SNOW CONTINUES AT ALL TERMINAL SITES...WITH WINDS BECOMING
INCREASINGLY GUSTY AT ALL SITES THROUGH THE NIGHT...HELPING
DEVELOP SOME AREAS OF BLOWING/DRIFTING SNOW AS WELL. SNOWFALL
RATES WILL GENERALLY BE AROUND A HALF INCH PER HOUR...BUT WILL
LIKELY REACH AN INCH PER HOUR AT TIMES DURING THE 00-07Z
TIMEFRAME. SYNOPTIC SNOWS WILL WIND DOWN THROUGH THE MORNING
HOURS...WITH LAKE EFFECT SNOW SHOWERS TAKING OVER...PREDOMINANTLY
AT THE TVC AND MBL TERMINALS. CONDITIONS EVERYWHERE ARE EXPECTED
TO IMPROVE TO MVFR THROUGH THE MORNING HOURS.
LAWRENCE
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY UNTIL 7 PM EST FRIDAY FOR MIZ008-015>019-
022>024-027>029-033-034.
WINTER STORM WARNING UNTIL 7 PM EST FRIDAY FOR MIZ020-021-025-
026-031-032.
LH...SMALL CRAFT ADVISORY UNTIL 11 PM EST FRIDAY FOR LHZ345>349.
LM...SMALL CRAFT ADVISORY UNTIL 11 PM EST FRIDAY FOR LMZ323-341-342.
GALE WARNING UNTIL 5 PM EST FRIDAY FOR LMZ344>346.
LS...SMALL CRAFT ADVISORY UNTIL 11 PM EST FRIDAY FOR LSZ321-322.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
1028 AM CST WED JAN 11 2012
.UPDATE...ONLY CHANGE THIS MORNING WAS TO LOWER AFTERNOON HIGHS IN
CONCERT WITH THE COOLER NAM GUIDANCE...ESPECIALLY ACROSS AREAS ALONG
AND NORTHEAST OF THE HWY 49 CORRIDOR WHERE THE LOW CLOUDS WILL BE
MOST STUBBORN THROUGH THE DAY. LATEST RUC GUIDANCE SUGGESTS THE
CLOUDS MAY TRY TO BREAK UPPER FURTHER WEST/SOUTH LATER THIS AFTERNOON
WHICH MAY ALLOW TEMPS TO RISE INTO THE MID 50S TO NEAR 60 IN A FEW
SPOTS. REST OF THE FORECAST LOOKS TO BE IN GOOD SHAPE...UPDATED
AVIATION DISCUSSION APPENDED BELOW. /BK/
&&
.PREV DISCUSSION... /ISSUED 343 AM CST WED JAN 11 2012/
DISCUSSION...TODAY THROUGH THURSDAY NIGHT...WHILE THE SURFACE LOW
AND COLD FRONT HAVE ALL BUT CLEARED THE CWA THIS MORNING...SATELLITE
SHOWS A VIGOROUS UPPER LOW LIFTING NORTHEAST DIRECTLY OVER THE
FORECAST AREA. THIS UPPER LOW WILL BE RESPONSIBLE FOR PRODUCING
SOME PATCHY OF DRIZZLE...AND EVEN SOME LIGHT RAIN...THROUGH THE
MORNING AND INTO THE EARLY AFTERNOON. LOW CLOUDS WILL ALSO PLAGUE
MUCH OF THE AREA TODAY...ESPECIALLY NORTHEAST MISSISSIPPI...BUT SOME
BREAKS WILL LIKELY BEE SEEN ACROSS THE WESTERN HALF OF THE CWA
DURING THE AFTERNOON. TEMPERATURES THIS AFTERNOON WILL STRUGGLE TO
GET OUT OF THE 50S IN MOST LOCATIONS...WITH LOWER 60S POSSIBLE
ACROSS THE SOUTH.
CLOUDS WILL TRY TO CLEAR OUT TONIGHT BUT TO NO AVAIL. ANOTHER...
STRONGER BUT MAINLY DRY...COLD FRONT WILL RACE IN FROM THE NORTHWEST
AND THROUGH THE CWA OVERNIGHT AND INTO EARLY THURSDAY MORNING.
OTHER THAN A FEW SPRINKLES OVER THE NORTH...NOT MUCH IN THE WAY OF
PRECIPITATION IS EXPECTED WITH THIS FRONT AS IT PUSHES THROUGH.
NOTICEABLY COLDER DRIER AIR THOUGH WILL BEGIN TO SURGE INTO THE CWA
FROM THE NORTHWEST AS TEMPERATURES RANGE FROM THE MID 30S TO MID 40S
EARLY THURSDAY MORNING.
STRONG COLD ADVECTION WILL BE ONGOING ACROSS THE REGION THROUGH THE
DAY THURSDAY WITH MUCH COLDER DRIER CONDITIONS EXPECTED. HIGHS
THURSDAY WILL STRUGGLE TO CLIMB OUT OF THE 40S WITH A STRONG
NORTHWEST WIND EXPECTED DURING THE DAY. WITH A TIGHT PRESSURE
GRADIENT OVER THE REGION...WINDS RIGHT NOW ON THURSDAY WILL LIKELY
BE SUSTAINED BETWEEN 20-25 MPH...WITH GUSTS AT OR GREATER THAN 30
MPH POSSIBLE. IF IT APPEARS WINDS COULD BE STRONGER...A WIND
ADVISORY MAY BE NEEDED FOR AT LEAST PORTIONS OF THE CWA THURSDAY.
WINDS WILL RELAX AS SKIES BECOME MOSTLY CLEAR EARLY THURSDAY
NIGHT...THUS CAUSING THE MERCURY TO RAPIDLY FALL. RIGHT NOW I`LL
STICK WITH MAV GUIDANCE WHICH SUGGESTS LOWS IN THE LOWER 20S FOR
EARLY FRIDAY MORNING. HOWEVER...AFTER MIDNIGHT AND TOWARDS DAY
BREAK...SOME HIGH CLOUDS COULD BEGIN TO SPREAD EAST AND OVER THE
AREA. IF THIS HAPPENS...LOWS FRIDAY MORNING COULD BE A COUPLE OF
DEGREES WARMER THAN CURRENTLY FORECAST...BUT STILL IN 20S. /19/
FRIDAY THROUGH NEXT WEDNESDAY...THE MED RANGE/LONG TERM WILL OFFER
TWO PATTERNS WITH HIGHER THAN USUAL CONFIDENCE BASE OFF NUMERICAL
MODELS BEING IS SOLID AGREEMENT. THE FIRST HALF OF THE EXTENDED WILL
FEATURE COLDER TEMPS WHILE THE LATTER HALF WILL TRANSITION TO A
WETTER PERIOD.
FOR FRI...THE CENTER OF THE COLD CANADIAN AIRMASS WILL BE SHIFTING
OVER THE CWA WITH VERY DRY AIR IN PLACE. AFTER A COLD START TO THE
DAY...HIGH TEMPS WILL REBOUND A BIT...BUT REMAIN 6-10 DEGREES BELOW
AVG. MID/UPPER 40S WILL SHOULD BE EXPECTED WHICH IS A COUPLE DEGREES
LOWER THAN THE GFS GUID. SFC HIGH PRESSURE WILL REMAIN OVER THE CWA
FOR FRI NGT AND OFFER ANOTHER COLD NGT. MY INITIAL THOUGHT WAS TO
CUT LOWS SOME...BUT ALL THE MODELS INDICATE SOME UPPER LEVEL CLOUDS
MOVING BY AND THAT MAY JUST BE ENOUGH TO PREVENT PERFECT RAD COOLING
CONDITIONS.
BY SAT...THE SFC HIGH BEGINS TO SHIFT AWAY FROM THE CWA AND SLIGHT
RETURN FLOW WILL TAKE PLACE ALLOWING FOR MODERATING CONDITIONS.
AGAIN...THE PRESENCE OF SOME HIGH CLOUDS EARLY AND COLD START TO THE
DAY...FEEL THE GFS IS WARMING THINGS TOO QUICKLY. AS A RESULT...HAVE
FOLLOWED THE ENSEMBLE SOLUTION FOR HIGHS...MID 50S. SUNDAY WILL BE
THE DAY OF TRANSITION...LOOK FOR A COOL START TO THE DAY AND A
BETTER WARMUP FOR AFTERNOON.
BETTER RETURN FLOW WILL TAKE SHAPE FOR MON AS A STRONG GRADIENT
DEVELOPS IN RESPONSE TO THE NEXT SYSTEM AND SFC FRONT. INCREASING
PRECIP CHANCES WILL DEVELOP FOR MON ACROSS THE NW...THEN SPREAD OVER
THE ENTIRE AREA FOR MON NGT INTO TUE. GUID WAS OFFERING 40% POPS
DURING THIS TIME AND THAT SEEMS REASONABLE GIVEN ITS DAY 5/6. FOR
NOW...ONLY WILL MENTION SHOWERS...BUT SOME THUNDER MAY HAVE TO BE
ADDED IF THE MODELS CAN AGREE ON BETTER LAPSE RATES. /CME/
&&
.AVIATION...
LOWS CLOUDS AND PATCHY DRIZZLE WILL KEEP CEILINGS IN THE MVFR/IFR
RANGE THROUGH A GOOD BIT OF THE DAY...WITH LOW CLOUDS HANGING AROUND
INTO TONIGHT. WEST TO WEST SOUTHWEST SURFACE WINDS BETWEEN 10-15 MPH
ARE EXPECTED TODAY...BUT WILL BECOME GUSTY FROM THE NORTHWESTERLY
LATE TONIGHT INTO THURSDAY MORNING AS ANOTHER STRONG COLD FRONT MOVES
THROUGH. ANY SITE THAT SEES VFR CONDITIONS OVER THE NEXT 24 HOURS
WILL BE BRIEF. /28/19/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 53 39 45 23 / 4 9 10 0
MERIDIAN 53 39 47 23 / 6 10 11 0
VICKSBURG 55 38 44 22 / 2 11 9 0
HATTIESBURG 61 44 50 22 / 7 14 10 0
NATCHEZ 56 39 43 23 / 1 8 7 0
GREENVILLE 53 36 42 23 / 5 16 11 0
GREENWOOD 53 38 43 22 / 11 12 12 0
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
BK/28
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1140 AM CST WED JAN 11 2012
.AVIATION...18Z TAFS FOR KOFK...KOMA AND KLNK.
A STRONG COLD FRONT HAS MOVED THRU THE TAF SITES LEAVING STRONG
AND GUSTY NORTHWEST SFC WINDS BEHIND IT. SFC WINDS SUSTAINED
AROUND 25 TO 30 KTS WITH GUSTS UP TO 40 TO 45 KTS WILL CONTINUE
THROUGH THE AFTERNOON AND ONLY WEAKEN SLIGHTLY AFTER 00Z. A BAND
OF SNOW SHOWERS WILL CONTINUE TO PASS OVER THE SITES FROM
NORTHWEST TO SOUTHEAST. VISIBILITIES WILL COME DOWN TO NEAR IFR
CONDITIONS BUT SNOWFALL IS EXPECTED TO REMAIN LIGHT WITH UNDER A
HALF INCH OF ACCUMULATION. BLOWING DUST IS OCCURRING AT KOMA AND
WILL LIKELY CONTINUE THROUGH THE AFTERNOON. THIS IS MOST LIKELY
FROM SEDIMENT BEING STIRRED UP AND BLOWN AROUND FROM LAST SUMMERS
MISSOURI RIVER FLOOD. CEILINGS ARE EXPECTED TO REMAIN IN THE MVFR
CATEGORY THROUGH THE TAF PERIOD.
LIGHT FLURRIES ARE POSSIBLE AGAIN OVERNIGHT AS A SECONDARY
DISTURBANCE ROTATES THRU THE AREA.
KERN
&&
.PREV DISCUSSION... /ISSUED 516 AM CST WED JAN 11 2012/
AVIATION...
06Z TAFS FOR KOFK...KOMA AND KLNK.
A STRONG COLD FRONT THAT PUSHED THROUGH KOFK BEFORE TAF ISSUANCE
WILL QUICKLY MOVE ACROSS KOMA/KLNK WITH SURFACE WINDS EASILY
GUSTING OVER 30KTS. LOW CLOUDS IN THE LOW MVFR CATEGORY...POSSIBLY
IFR CATEGORY AT KOFK...WILL MOVE IN AN HOUR OR TWO AFTER FRONT
PASSES. IN ADDITION...SNOW SHOWERS THAT ARE LIKELY LATER THIS
MORNING MORNING THROUGH THIS AFTERNOON COULD REDUCE VISIBILITIES
DOWN TO 3 OR 4 MILES. ALTHOUGH THERE WAS SOME INDICATION THE
INTENSITY WOULD WEAKEN COMPARED TO UPSTREAM CONDITIONS WHERE SOME
VISIBILITIES DROPPED BELOW 1 MILE...CONFIDENCE NOT HIGH. LOW
CEILINGS AND ADDITIONAL SNOW SHOWERS/FLURRIES LIKELY LATER TONIGHT
AS SECOND DISTURBANCE MOVES ACROSS THE REGION.
CHERMOK
PREV DISCUSSION... /ISSUED 245 AM CST WED JAN 11 2012/
DISCUSSION...
COLD FRONT JUST BEGINNING TO ENTER NORTHWEST PORTION OF THE CWA AT
08Z WITH WIND SHIFT AT KBVN AND KYKN. COLDER AIR AND BAND OF
PRECIP LAGS BEHIND THE BOUNDARY HOWEVER WITH INITIAL WINDS
BOOSTING TEMPERATURES INTO THE LOWER 40S IMMEDIATELY BEHIND THE
BOUNDARY. 05Z HRRR MODEL HAS FRONT THROUGH MOST OF THE CWA BY 15Z
WITH THE COLDER AIR AND PRECIP JUST COMING INTO NORTHEAST
NEBRASKA AT THAT TIME. WINDS INCREASE ACROSS THE REMAINDER OF THE
CWA THEREAFTER...HAVE ADDED EASTERN PARTS OF THE CWA FROM
SOUTHEAST NEBRASKA INTO SOUTHWEST IOWA TO WIND ADVISORY AFTER 18Z.
A MIX OF RAIN AND SNOW SHOWERS POSSIBLE INITIALLY BEFORE CHANGING
TO ALL SNOW AS COLDER AIR MOVES IN. ONLY MINOR SNOWFALL EXPECTED
SINCE WIDTH OF PRECIP BAND FAIRLY NARROW AND SYSTEM MOVING THROUGH
QUICKLY. ANY REMAINING SNOW SHOWERS OR FLURRIES EXPECTED TO END
EARLY THIS EVENING IN THE FAR SOUTHEAST CORNER OF THE CWA.
TEMPERATURES...WIND AND SKY CONDITION THEN BECOME THE MAIN FOCUS
FOR TONIGHT INTO THURSDAY NIGHT AS UPPER LOW GRADUALLY SHIFTS
EAST. SLIGHTLY WARMER TEMPERATURES RETURN ON FRIDAY BUT ANY
WARMING LOOKS TO BE SHORT LIVED AS NEXT CLIPPER DROPPING INTO
NORTHERN MINNESOTA BY SATURDAY MORNING ALSO PULLS DOWN ANOTHER
BATCH OF COLD AIR WITH IT.
MORE SIGNIFICANT WARMING LIKELY EARLY IN THE EXTENDED PERIOD OVER
THE WEEKEND AS RIDGING MOVES INTO THE REGION AHEAD OF NEXT UPPER
WAVE COMING INTO THE PACIFIC NORTHWEST. ANOTHER COLD FRONT THEN
MOVES THROUGH ON MONDAY AS THE WAVE TRACKS EAST ACROSS THE PLAINS.
COLDEST AIR HOWEVER LOOKS TO STAY TO THE NORTH ALONG THE CANADIAN
BORDER AS UPPER FLOW BECOMES STRONGLY ZONAL...ESPECIALLY BY THE
ECMWF.
FOBERT
AVIATION...
06Z TAFS FOR KOMA...KLNK...KOFK.
NO SIGNIFICANT CHANGES FROM PREVIOUS FORECAST...ALTHOUGH DID
TWEAK THE TIMING OF THE ARRIVAL OF THE COLD FRONT TO 11Z AT
KOFK...13Z AT KLNK AND 14Z AT KOMA. LATEST RUC TRENDS WOULD
SUGGEST THAT IT MIGHT EVEN BE EVENHOUR BEYOND THAT. FEEL THAT
SCATTERED SNOW SHOWERS WILL DEVELOP AT BOTH KOFK/KOMA BEHIND THE
FRONT...ALTHOUGH NOT AS CONFIDENT THAT THEY WILL DEVELOP AT KLNK.
ALSO UNCERTAIN HOW LOW VISIBILITIES WILL DROP...GIVEN 25 TO 35 MPH
WINDS WITH HIGHER GUSTS. AM SEEING SEVERAL UPSTREAM REPORTS IN THE
3 MILE RANGE WITH SNOW...SO USED THAT AS A BEST ESTIMATE UNTIL THE
SNOW BAND GETS A LITTLE CLOSER
DEWALD
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR NEZ067-068-090>093.
WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR NEZ011-012-015>018-
030>034-042>045-050>053-065-066-078-088-089.
IA...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR IAZ055-056-069-079-
080-090-091.
WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR IAZ043.
&&
$$
99/99
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
516 AM CST WED JAN 11 2012
.AVIATION...
06Z TAFS FOR KOFK...KOMA AND KLNK.
A STRONG COLD FRONT THAT PUSHED THROUGH KOFK BEFORE TAF ISSUANCE
WILL QUICKLY MOVE ACROSS KOMA/KLNK WITH SURFACE WINDS EASILY
GUSTING OVER 30KTS. LOW CLOUDS IN THE LOW MVFR CATEGORY...POSSIBLY
IFR CATEGORY AT KOFK...WILL MOVE IN AN HOUR OR TWO AFTER FRONT
PASSES. IN ADDITION...SNOW SHOWERS THAT ARE LIKELY LATER THIS
MORNING MORNING THROUGH THIS AFTERNOON COULD REDUCE VISIBILITIES
DOWN TO 3 OR 4 MILES. ALTHOUGH THERE WAS SOME INDICATION THE
INTENSITY WOULD WEAKEN COMPARED TO UPSTREAM CONDITIONS WHERE SOME
VISIBILITIES DROPPED BELOW 1 MILE...CONFIDENCE NOT HIGH. LOW
CEILINGS AND ADDITIONAL SNOW SHOWERS/FLURRIES LIKELY LATER TONIGHT
AS SECOND DISTURBANCE MOVES ACROSS THE REGION.
CHERMOK
&&
.PREV DISCUSSION... /ISSUED 245 AM CST WED JAN 11 2012/
DISCUSSION...
COLD FRONT JUST BEGINNING TO ENTER NORTHWEST PORTION OF THE CWA AT
08Z WITH WIND SHIFT AT KBVN AND KYKN. COLDER AIR AND BAND OF
PRECIP LAGS BEHIND THE BOUNDARY HOWEVER WITH INITIAL WINDS
BOOSTING TEMPERATURES INTO THE LOWER 40S IMMEDIATELY BEHIND THE
BOUNDARY. 05Z HRRR MODEL HAS FRONT THROUGH MOST OF THE CWA BY 15Z
WITH THE COLDER AIR AND PRECIP JUST COMING INTO NORTHEAST
NEBRASKA AT THAT TIME. WINDS INCREASE ACROSS THE REMAINDER OF THE
CWA THEREAFTER...HAVE ADDED EASTERN PARTS OF THE CWA FROM
SOUTHEAST NEBRASKA INTO SOUTHWEST IOWA TO WIND ADVISORY AFTER 18Z.
A MIX OF RAIN AND SNOW SHOWERS POSSIBLE INITIALLY BEFORE CHANGING
TO ALL SNOW AS COLDER AIR MOVES IN. ONLY MINOR SNOWFALL EXPECTED
SINCE WIDTH OF PRECIP BAND FAIRLY NARROW AND SYSTEM MOVING THROUGH
QUICKLY. ANY REMAINING SNOW SHOWERS OR FLURRIES EXPECTED TO END
EARLY THIS EVENING IN THE FAR SOUTHEAST CORNER OF THE CWA.
TEMPERATURES...WIND AND SKY CONDITION THEN BECOME THE MAIN FOCUS
FOR TONIGHT INTO THURSDAY NIGHT AS UPPER LOW GRADUALLY SHIFTS
EAST. SLIGHTLY WARMER TEMPERATURES RETURN ON FRIDAY BUT ANY
WARMING LOOKS TO BE SHORT LIVED AS NEXT CLIPPER DROPPING INTO
NORTHERN MINNESOTA BY SATURDAY MORNING ALSO PULLS DOWN ANOTHER
BATCH OF COLD AIR WITH IT.
MORE SIGNIFICANT WARMING LIKELY EARLY IN THE EXTENDED PERIOD OVER
THE WEEKEND AS RIDGING MOVES INTO THE REGION AHEAD OF NEXT UPPER
WAVE COMING INTO THE PACIFIC NORTHWEST. ANOTHER COLD FRONT THEN
MOVES THROUGH ON MONDAY AS THE WAVE TRACKS EAST ACROSS THE PLAINS.
COLDEST AIR HOWEVER LOOKS TO STAY TO THE NORTH ALONG THE CANADIAN
BORDER AS UPPER FLOW BECOMES STRONGLY ZONAL...ESPECIALLY BY THE
ECMWF.
FOBERT
AVIATION...
06Z TAFS FOR KOMA...KLNK...KOFK.
NO SIGNIFICANT CHANGES FROM PREVIOUS FORECAST...ALTHOUGH DID
TWEAK THE TIMING OF THE ARRIVAL OF THE COLD FRONT TO 11Z AT
KOFK...13Z AT KLNK AND 14Z AT KOMA. LATEST RUC TRENDS WOULD
SUGGEST THAT IT MIGHT EVEN BE EVENHOUR BEYOND THAT. FEEL THAT
SCATTERED SNOW SHOWERS WILL DEVELOP AT BOTH KOFK/KOMA BEHIND THE
FRONT...ALTHOUGH NOT AS CONFIDENT THAT THEY WILL DEVELOP AT KLNK.
ALSO UNCERTAIN HOW LOW VISIBILITIES WILL DROP...GIVEN 25 TO 35 MPH
WINDS WITH HIGHER GUSTS. AM SEEING SEVERAL UPSTREAM REPORTS IN THE
3 MILE RANGE WITH SNOW...SO USED THAT AS A BEST ESTIMATE UNTIL THE
SNOW BAND GETS A LITTLE CLOSER
DEWALD
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WIND ADVISORY FROM NOON TODAY TO 6 PM CST THIS EVENING FOR
NEZ067-068-090>093.
WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR NEZ015-033-034-
043>045-050>053-065-066-078-088-089.
WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR NEZ011-012-016>018-
030>032-042.
IA...WIND ADVISORY FROM NOON TODAY TO 6 PM CST THIS EVENING FOR
IAZ055-056-069-079-080-090-091.
WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR IAZ043.
&&
$$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
352 AM CST WED JAN 11 2012
.SHORT TERM...TODAY THROUGH 12Z SATURDAY. MAIN FORECAST CONCERNS
WILL BE CHANCE FOR SNOW...WIND AND FALLING TEMPERATURES TODAY AND
TEMPERATURES THROUGH THE PERIOD.
SURFACE ANALYSIS AND OBSERVATIONS SHOW A COLD FRONT IN THE NORTHWEST
PART OF TE FORECAST AREA EARLY THIS MORNING. THE COLD FRONT WILL
CONTINUE TO PUSH THROUGH THE FORECAST AREA THROUGH THE REMAINDER OF
THE NIGHT. BEHIND THE FRONT WILL BE STRONG NORTHWEST WINDS AS
ALREADY EVIDENCED BY WINDS IN PORTIONS OF NORTH CENTRAL NEBRASKA.
THE WIND ADVISORY WILL CONTINUE BUT THE SOUTHEAST WILL BE A FEW
HOURS BEFORE THE WINDS INCREASE TO WIND ADVISORY CRITERIA.
AN UPPER LEVEL WAVE WILL MOVE THROUGH THE AREA TODAY. THERE WILL BE
SOME FRONTOGENESIS AS THE WAVE MOVES THROUGH AND WITH THE CLOUDS AND
MOISTURE AVAILABLE THERE WILL BE SOME FLURRIES ACROSS THE AREA. THE
QUESTION COMES IN WHETHER THERE WILL BE MORE THAN FLURRIES AND HAVE
SOME ACCUMULATION. MODELS HAVE SOME DIFFERENCES IN WHETHER THERE
WILL BE ACCUMULATION. THE NAM BRINGS VERY LIGHT QPF ACROSS THE AREA
BUT THE GFS AND ECMWF SPLITS THE PRECIPITATION AS IT MOVES ACROSS
THE AREA. WITH THE FRONTOGENESIS STRONGEST IN THE SOUTHEAST THIS
AFTERNOON HAVE PUT IN SOME LOW POPS BUT ONLY EXPECT LIGHT AMOUNTS.
TEMPERATURES ARE EXPECTED TO BE NEARLY STEADY OR EVEN FALL DURING
THE DAY AS COLDER AIR RUSHES IN BEHIND THE COLD FRONT. THE COLD AIR
LINGERS ACROSS THE AREA THROUGH THURSDAY NIGHT WITH HIGHS ONLY IN
THE 20S TO AROUND 30 AND LOWS 7 TO 15 DEGREES.
.LONG TERM...SATURDAY THROUGH TUESDAY. THE WARMING TREND WILL
CONTINUE INTO THE WEEKEND WITH SUNDAY SHAPING UP TO BE THE NICEST
DAY OF THE NEXT SEVEN. ANOTHER COLD FRONT WILL THEN COME THROUGH THE
REGION ON MONDAY RESULTING IN A COOL DOWN...WITH EVEN COLDER
TEMPERATURES BY TUESDAY.
THE TYPICAL MODEL ALL BLEND GUIDANCE USED IN THE EXTENDED PERIOD
CONTINUES TO NOT MAKE THE GRADE FOR SUNDAY AND WAS THROWN OUT IN
FAVOR OF THE BIAS CORRECTED ALL BLEND MODEL. THERE HAS BEEN A MODEL
COOL BIAS IN THE EXTENDED PERIODS NEARLY ALL WINTER DUE IN PART TO
THE LACK OF SNOW COVER...AND THE SET UP ON SUNDAY IS LIKELY GOING TO
BE ANOTHER EXAMPLE OF THIS MODEL COOL BIAS. FOR INSTANCE...850MB
TEMPERATURES YESTERDAY WERE AROUND 6-8C WITH LIGHT SOUTHWEST
WINDS...WHICH RESULTED IN HIGHS THAT WERE AROUND 60 DEGREES. 850MB
TEMPERATURES ON SUNDAY AS INDICATED IN BOTH THE 00Z GFS AND 00Z
ECMWF SHOULD AGAIN BE IN THE 6-8C RANGE WITH SOUTH WINDS AND PLENTY
OF SUNSHINE. THE MODEL ALL BLEND GUIDANCE ONLY GIVES US HIGHS IN THE
UPPER 40S TO AROUND 50. SEEMS LIKE THERE MAY BE A PROBLEM HERE WITH
THAT COOL BIAS IN THE MODEL GUIDANCE THAT HAS BEEN THERE ALL SEASON.
THEREFORE...USING THE BIAS CORRECTED GRIDS WE ARE NOW FORECASTING
HIGHS ON SUNDAY IN THE LOWER TO MID 50S...WHICH SHOULD BE A GOOD
IMPROVEMENT OVER THE BASIC MODEL GUIDANCE VALUES.
A STRONG COLD FRONT WILL SWING THROUGH AT SOME POINT ON
MONDAY...MAKING HIGHS VERY TRICKY TO FORECAST AS THEY WILL GREATLY
DEPEND ON THE TIMING OF THE FRONTAL PASSAGE. THE COLD AIR WILL MORE
ASSUREDLY HAVE INFILTRATED THE AREA BY TUESDAY...WHICH MAY KEEP MANY
AREAS FROM EVEN HITTING THE FREEZING MARK FOR HIGHS. DRY WEATHER
SEEMS LIKE IT WILL CONTINUE AS THESE FRONTS REALLY DO NOT HAVE MUCH
IN THE WAY OF MOISTURE ASSOCIATED WITH THEM.
&&
.PREV DISCUSSION... /ISSUED 1046 PM CST TUE JAN 10 2012/
AVIATION...06Z TAF. A STRONG COLD FRONT WILL MOVE ACROSS THE
REGION OVERNIGHT. THIS WILL TURN WINDS FROM THE SOUTHWEST TO A
NORTHWESTERLY DIRECTION AROUND 09Z...WITH THEM ALSO BECOMING
GUSTY. WINDS WILL BECOME EVEN STRONGER AFTER DAYBREAK WITH GUSTS
OF 36 KTS OR GREATER POSSIBLE. ANOTHER CONCERN WILL BE THE CHANCE
FOR LIGHT SNOW OR FLURRIES AS AN UPPER LEVEL DISTURBANCE MOVES
THROUGH THE REGION. THE LATEST NAM SUGGESTS THERE COULD BE LIGHT
SNOW...WHILE THE GFS IS STILL NOT SHOWING MUCH IN THE WAY OF QPF.
WILL CONTINUE WITH THE MENTION OF VCSH IN THE TAF FOR NOW SINCE
CONFIDENCE IN HOW MUCH SNOW/FLURRIES WILL ACTUALLY TAKE PLACE AT
KGRI IS LOW. CEILINGS WILL BE SOMETHING ELSE TO MONITOR WITH NAM
PROXIMITY SOUNDINGS SUGGESTING MVFR CONDITIONS WILL TAKE HOLD FOR
AT LEAST A FEW HOURS BEHIND THE COLD FRONT. THIS IS ALSO SHOWN BY
THE LATEST RUC SOUNDINGS...SO WILL HOLD ONTO THE MVFR CONDITIONS
IN THE TAF STARTING AROUND 11Z...BUT GO BACK TO VFR DURING THE
EARLY AFTERNOON AS PER THE NAM FORECAST SOUNDINGS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR NEZ039>041-046>049-
060>064-072>077-082>087.
KS...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR KSZ005>007-017>019.
&&
$$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
245 AM CST WED JAN 11 2012
.DISCUSSION...
COLD FRONT JUST BEGINNING TO ENTER NORTHWEST PORTION OF THE CWA AT
08Z WITH WIND SHIFT AT KBVN AND KYKN. COLDER AIR AND BAND OF
PRECIP LAGS BEHIND THE BOUNDARY HOWEVER WITH INITIAL WINDS
BOOSTING TEMPERATURES INTO THE LOWER 40S IMMEDIATELY BEHIND THE
BOUNDARY. 05Z HRRR MODEL HAS FRONT THROUGH MOST OF THE CWA BY 15Z
WITH THE COLDER AIR AND PRECIP JUST COMING INTO NORTHEAST
NEBRASKA AT THAT TIME. WINDS INCREASE ACROSS THE REMAINDER OF THE
CWA THEREAFTER...HAVE ADDED EASTERN PARTS OF THE CWA FROM
SOUTHEAST NEBRASKA INTO SOUTHWEST IOWA TO WIND ADVISORY AFTER 18Z.
A MIX OF RAIN AND SNOW SHOWERS POSSIBLE INITIALLY BEFORE CHANGING
TO ALL SNOW AS COLDER AIR MOVES IN. ONLY MINOR SNOWFALL EXPECTED
SINCE WIDTH OF PRECIP BAND FAIRLY NARROW AND SYSTEM MOVING THROUGH
QUICKLY. ANY REMAINING SNOW SHOWERS OR FLURRIES EXPECTED TO END
EARLY THIS EVENING IN THE FAR SOUTHEAST CORNER OF THE CWA.
TEMPERATURES...WIND AND SKY CONDITION THEN BECOME THE MAIN FOCUS
FOR TONIGHT INTO THURSDAY NIGHT AS UPPER LOW GRADUALLY SHIFTS
EAST. SLIGHTLY WARMER TEMPERATURES RETURN ON FRIDAY BUT ANY
WARMING LOOKS TO BE SHORT LIVED AS NEXT CLIPPER DROPPING INTO
NORTHERN MINNESOTA BY SATURDAY MORNING ALSO PULLS DOWN ANOTHER
BATCH OF COLD AIR WITH IT.
MORE SIGNIFICANT WARMING LIKELY EARLY IN THE EXTENDED PERIOD OVER
THE WEEKEND AS RIDGING MOVES INTO THE REGION AHEAD OF NEXT UPPER
WAVE COMING INTO THE PACIFIC NORTHWEST. ANOTHER COLD FRONT THEN
MOVES THROUGH ON MONDAY AS THE WAVE TRACKS EAST ACROSS THE PLAINS.
COLDEST AIR HOWEVER LOOKS TO STAY TO THE NORTH ALONG THE CANADIAN
BORDER AS UPPER FLOW BECOMES STRONGLY ZONAL...ESPECIALLY BY THE
ECMWF.
&&
.AVIATION...
06Z TAFS FOR KOMA...KLNK...KOFK.
NO SIGNIFICANT CHANGES FROM PREVIOUS FORECAST...ALTHOUGH DID
TWEAK THE TIMING OF THE ARRIVAL OF THE COLD FRONT TO 11Z AT
KOFK...13Z AT KLNK AND 14Z AT KOMA. LATEST RUC TRENDS WOULD
SUGGEST THAT IT MIGHT EVEN BE EVENHOUR BEYOND THAT. FEEL THAT
SCATTERED SNOW SHOWERS WILL DEVELOP AT BOTH KOFK/KOMA BEHIND THE
FRONT...ALTHOUGH NOT AS CONFIDENT THAT THEY WILL DEVELOP AT KLNK.
ALSO UNCERTAIN HOW LOW VISIBILITIES WILL DROP...GIVEN 25 TO 35 MPH
WINDS WITH HIGHER GUSTS. AM SEEING SEVERAL UPSTREAM REPORTS IN THE
3 MILE RANGE WITH SNOW...SO USED THAT AS A BEST ESTIMATE UNTIL THE
SNOW BAND GETS A LITTLE CLOSER
DEWALD
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WIND ADVISORY FROM NOON TODAY TO 6 PM CST THIS EVENING FOR
NEZ067-068-090>093.
WIND ADVISORY FROM 8 AM THIS MORNING TO 6 PM CST THIS EVENING
FOR NEZ015-033-034-043>045-050>053-065-066-078-088-089.
WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR NEZ011-012-016>018-
030>032-042.
IA...WIND ADVISORY FROM NOON TODAY TO 6 PM CST THIS EVENING FOR
IAZ055-056-069-079-080-090-091.
WIND ADVISORY FROM 8 AM THIS MORNING TO 6 PM CST THIS EVENING
FOR IAZ043.
&&
$$
FOBERT
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1137 PM CST TUE JAN 10 2012
.AVIATION...06Z TAFS FOR KOMA...KLNK...KOFK. NO SIGNIFICANT
CHANGES FROM PREVIOUS FORECAST...ALTHOUGH DID TWEAK THE TIMING OF
THE ARRIVAL OF THE COLD FRONT TO 11Z AT KOFK...13Z AT KLNK AND 14Z
AT KOMA. LATEST RUC TRENDS WOULD SUGGEST THAT IT MIGHT EVEN BE
EVENHOUR BEYOND THAT. FEEL THAT SCATTERED SNOW SHOWERS WILL
DEVELOP AT BOTH KOFK/KOMA BEHIND THE FRONT...ALTHOUGH NOT AS
CONFIDENT THAT THEY WILL DEVELOP AT KLNK. ALSO UNCERTAIN HOW LOW
VISIBILITIES WILL DROP...GIVEN 25 TO 35 MPH WINDS WITH HIGHER
GUSTS. AM SEEING SEVERAL UPSTREAM REPORTS IN THE 3 MILE RANGE WITH
SNOW...SO USED THAT AS A BEST ESTIMATE UNTIL THE SNOW BAND GETS A
LITTLE CLOSER.
DEWALD
&&
.PREV DISCUSSION... /ISSUED 927 PM CST TUE JAN 10 2012/
DISCUSSION...
MADE SOME MINOR TWEAKS TO THE FORECAST FOR PRECIPITATION TOMORROW...
MAINLY INCREASING THE AREAL COVERAGE OF SOME LIGHT SNOW OR FLURRIES
THAT SHOULD MOVE THROUGH THE REGION. THIS LOOKS LIKE A HIGHER
PROBABILITY OF OCCURRENCE...BUT GENERALLY LOW AMOUNTS EXPECTED.
ALSO BELIEVE THAT THE COLDER AIR WILL RUSH IN FAST ENOUGH BEHIND
THE FRONT THAT IT WILL PROBABLY BE ALL SNOW. SNOWFALL AMOUNTS
WOULD RANGE LESS THAN ONE HALF INCH...BUT WITH 25 TO 35 MPH
WINDS...REDUCED VISIBILITY WILL BE POSSIBLE. MADE OTHER MINIMAL
CHANGES TO TEMPS...RAISING OVERNIGHT LOWS IN MOST SPOTS A COUPLE
OF DEGREES...ALTHOUGH A COUPLE OF SPOTS HAD ALREADY BOTTOMED OUT
BELOW PREVIOUS FORECAST BECAUSE WINDS WENT CALM...SO MADE SO
MESOSCALE ADJUSTMENTS FOR THAT. BELIEVE THAT TEMPS WILL FALL
BEHIND THE FRONT TOMORROW...AND SHOULD RISE A BIT AHEAD OF THE
FRONT IN THE MORNING...BUT THEN FALL IN THOSE AREAS IN THE
AFTERNOON.
DEWALD
PREV DISCUSSION... /ISSUED 505 PM CST TUE JAN 10 2012/
AVIATION...00Z TAFS FOR KOMA...KLNK AND KOFK.
A COLD FRONT WILL MOVE THROUGH THE FORECAST AREA THIS PERIOD WILL
BE THE MAIN CHALLENGE... ARRIVING AT KOFK BY 11Z...KLNK BY 12Z...AND
KOMA BY 13Z. LIGHT SOUTH SOUTHWEST WINDS AHEAD OF THE FRONT...BUT
WINDS SHOULD ABRUPTLY SHIFT TO THE NORTHWEST AROUND 320 TO 340
DEGREES AND SUBSTANTIALLY INCREASE ONCE THE FRONT ARRIVES.
SUSTAINED WINDS WILL LIKELY INCREASE TO 26 TO 29KTS...WITH GUSTS
UP TO 34 TO 38 KTS BEHIND THE FRONT. AM ALSO EXPECTING MVFR
CEILINGS IMMEDIATELY BEHIND THE COLD FRONT AS WELL...THAT COULD
BRIEFLY BE IFR FOR AN HOUR OR TWO. COULD ALSO SEE SOME SNOW
FLURRIES FOR A PERIOD BEHIND THE FRONT ALSO...AS COLDER AIR RUSHES
INTO THE REGION COMBINED WITH AN INCREASE IN MOISTURE.
DEWALD
PREV DISCUSSION... /ISSUED 325 PM CST TUE JAN 10 2012/
SHORT TERM...TONIGHT THROUGH FRIDAY.
THE PRIMARY FORECAST CONCERNS DURING THIS PERIOD ARE WINDS FROM
LATE TONIGHT THROUGH WEDNESDAY AFTERNOON...SMALL CHANCES FOR
PRECIPITATION AND TEMPERATURES.
WATER VAPOR SATELLITE IMAGERY EARLY THIS AFTERNOON SHOWED A FAIRLY
STRONG SHORTWAVE TROUGH DROPPING SOUTHEAST TOWARD THE AREA FROM THE
ROCKY MOUNTAIN REGION. 12 HOUR HEIGHT FALLS WITH THIS FEATURE WERE
ESTIMATED AT UP TO 140 METERS AT 12Z. THIS WAVE WILL HELP DRIVE A
STRONG COLD FRONT THROUGH THE AREA LATE TONIGHT AND EARLY WEDNESDAY
MORNING. WENT AHEAD AND ISSUED A WIND ADVISORY FOR MUCH OF NORTHEAST
NEBRASKA STARTING AROUND 3 AM CST AND CONTINUED THAT UNTIL 6 PM.
ALSO WENT WITH AN ADVISORY ABOUT AS FAR SOUTHEAST AS ONAWA...OMAHA...
LINCOLN AND BEATRICE FROM 8 AM TO 6 PM. THIS ADVISORY MAY NEED SOME
ADJUSTMENT LATER. PRESSURE GRADIENT AHEAD OF THE FRONT REMAINS WEAK
TONIGHT SO SURFACE WINDS SHOULD BE RELATIVELY TONIGHT UNTIL FRONTAL
PASSAGE. WINDS WILL INCREASE DRAMATICALLY WITH FRONTAL PASSAGE DUE
TO INCREASED PRESSURE GRADIENT AND PRESSURE RISES. 12Z NAM INDICATED
3 HOUR PRESSURE RISES OF 3-4 MB MOVING INTO NORTHEAST NEBRASKA BY
12Z WEDNESDAY...THEN FOR A GOOD PORTION OF THE AREA BY 15Z. 925 MB
WINDS ALSO INCREASE TO 35-40 KNOTS WEDNESDAY MORNING.
TEMPERATURES SHOULD BE STEADY OR SLOWLY FALLING BY LATE MORNING IN
THE NORTHWEST HALF OF THE FORECAST AREA...THEN FOR THE REST OF THE
AREA BY EARLY AFTERNOON. FORCING AND MOISTURE APPEAR ADEQUATE FOR
SCATTERED LIGHT SNOW SHOWERS...SOME OF WHICH COULD PRODUCE A FEW
TENTHS OF AN INCH OF ACCUMULATION. MODELS SUGGEST THAT THE CHANCE
FOR MEASURABLE SNOW IS THE HIGHEST ACROSS SOUTHEAST NEBRASKA AND
SOUTHWEST IOWA. SOME FLURRIES COULD ALSO OCCUR IN PARTS OF THE AREA
WEDNESDAY NIGHT INTO THURSDAY. THURSDAY IS FORECAST TO BE THE
COLDEST DAY OF THE WEEK...WITH HIGHS MOSTLY 20 TO 25.
THIS COLDER WEATHER IS SHORT LIVED...AS WARMER AIR STARTS TO SPREAD
IN FROM THE WEST BY LATE FRIDAY. HIGHS FRIDAY SHOULD REACH THE 30S
WEST AND 20S EAST.
MILLER
LONG TERM...FRIDAY NIGHT THROUGH TUESDAY.
THE MAIN FORECAST CHALLENGES IN THE EXTENDED WILL BE TEMPERATURES.
THE GENERAL PATTERN CONTINUES WITH NORTHWEST FLOW ALOFT AND FREQUENT
FRONTAL PASSAGES.
A FAST MOVING SHORTWAVE TROF WILL PASS THROUGH THE UPPER MISSISSIPPI
VALLEY AND GREAT LAKES FRIDAY NIGHT. THERE IS COLD AIR ADVECTION
SATURDAY BUT GOOD MIXING SHOULD PUSH HIGHS ABOVE FRIDAY/S
READINGS. WARMER AIR WILL RETURN SUNDAY AND MONDAY AS A MID LEVEL
RIDGE BUILDS IN. THE NEXT FRONT MOVES THROUGH MONDAY. MODERATING
HIGHS ARE FORECAST FOR SATURDAY WITH HIGHS IN THE 30S/40S...AND
WARMER READINGS FOR SUNDAY IN THE 40S AND 50S. MONDAY WILL BE TRICKY
AS ALLBLEND TEMPERATURES ARE ONLY IN THE 30S TO LOWER 40S. THE ECWMF
HAS THE FRONT JUST STARTING TO MOVE THROUGH BY MIDDAY MONDAY AND THE
GFS TRIES TO PULL CLOUDS NORTHWARD...HOWEVER THESE CLOUDS ARE ABSENT
IN THE ECMWF/GEM. WITH WEDGE OF HIGHER H85 TEMPS OVER THE
CWA...WENT ABOVE ALLBLEND AND HAVE HIGHS IN THE 40S MONDAY AND
COOLER 20S/30S FOR TUESDAY.
ZAPOTOCNY
AVIATION...
18Z TAFS FOR KOFK...KOMA AND KLNK
VFR CONDITIONS AND LIGHT SOUTHWEST WINDS WILL CONTINUE THROUGH
THE EVENING HOURS BUT THIS WILL CHANGE AS A STRONG COLD FRONT
DIVES INTO THE REGION AFTER 06Z. BEHIND THE FRONT...WE EXPECT A
SHORT PERIOD OF MVFR CIGS AND THEN A QUICK DROP TO AN IFR DECK.
SFC WINDS WILL INCREASE TO NEAR 25 TO 30 KTS WITH GUSTS UP TO 35
KTS BY 18Z.
KERN
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WIND ADVISORY FROM 8 AM TO 6 PM CST WEDNESDAY FOR NEZ015-033-034-
043>045-050>053-065-066-078-088-089.
WIND ADVISORY FROM 3 AM TO 6 PM CST WEDNESDAY FOR NEZ011-012-
016>018-030>032-042.
IA...WIND ADVISORY FROM 8 AM TO 6 PM CST WEDNESDAY FOR IAZ043.
&&
$$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1046 PM CST TUE JAN 10 2012
.AVIATION...06Z TAF. A STRONG COLD FRONT WILL MOVE ACROSS THE
REGION OVERNIGHT. THIS WILL TURN WINDS FROM THE SOUTHWEST TO A
NORTHWESTERLY DIRECTION AROUND 09Z...WITH THEM ALSO BECOMING
GUSTY. WINDS WILL BECOME EVEN STRONGER AFTER DAYBREAK WITH GUSTS
OF 36 KTS OR GREATER POSSIBLE. ANOTHER CONCERN WILL BE THE CHANCE
FOR LIGHT SNOW OR FLURRIES AS AN UPPER LEVEL DISTURBANCE MOVES
THROUGH THE REGION. THE LATEST NAM SUGGESTS THERE COULD BE LIGHT
SNOW...WHILE THE GFS IS STILL NOT SHOWING MUCH IN THE WAY OF QPF.
WILL CONTINUE WITH THE MENTION OF VCSH IN THE TAF FOR NOW SINCE
CONFIDENCE IN HOW MUCH SNOW/FLURRIES WILL ACTUALLY TAKE PLACE AT
KGRI IS LOW. CEILINGS WILL BE SOMETHING ELSE TO MONITOR WITH NAM
PROXIMITY SOUNDINGS SUGGESTING MVFR CONDITIONS WILL TAKE HOLD FOR
AT LEAST A FEW HOURS BEHIND THE COLD FRONT. THIS IS ALSO SHOWN BY
THE LATEST RUC SOUNDINGS...SO WILL HOLD ONTO THE MVFR CONDITIONS
IN THE TAF STARTING AROUND 11Z...BUT GO BACK TO VFR DURING THE
EARLY AFTERNOON AS PER THE NAM FORECAST SOUNDINGS.
&&
.PREV DISCUSSION... /ISSUED 359 PM CST TUE JAN 10 2012/
SHORT TERM...TONIGHT THROUGH WEDNESDAY. THE WEATHER PATTERN WILL
UNDERGO CHANGES BEGINNING TONIGHT...RETURNING TO THE WINTRY FEEL. AN
UPPER SHORTWAVE TROUGH EXTENDING FM BRITISH COLUMBIA INTO MT/ID WILL
DIG SOUTH ACROSS THE NORTHERN AND CENTRAL PLAINS TONIGHT AND
WEDNESDAY. AN ASSOCIATED STRONG COLD FRONTAL BOUNDARY WILL REACH
OUR NW CWA AROUND MIDNIGHT AND SWEEP SOUTHEAST THRU OUR CWA BY
DAYBREAK. SIX HOUR PRESSURE RISES BEHIND THE FRONT AVERAGE 4-8MB
AND A VERY TIGHT PRESSURE GRADIENT WILL BE IN PLACE ACROSS THE
CENTRAL PLAINS WEDNESDAY AS A 1038MB SURFACE HIGH BUILDS INTO THE
NORTHERN ROCKIES. H85 WINDS AVERAGE 45 TO 55KTS AND FORECAST
SOUNDINGS INDICATE MIXING BETWEEN H85 AND H8. RESULTANT SURFACE WIND
SPEEDS SHOULD AVERAGE NEAR 30 MPH WITH GUSTS NEAR 40 MPH...AND DUE
TO THE EXPECTED INTENSE WINDS WILL GO AHEAD WITH A WIND ADVISORY.
WILL BEGIN ADVISORY AT 4 AM AS FRONT WILL BE HALFWAY THRU THE CWA AT
THIS TIME...WITH WINDS IN THE SOUTHEAST CWA PICKING UP A FEW HOURS
LATER AFTER DAYBREAK. WINDS WILL REMAIN STRONG/GUSTY ALL DAY BEFORE
SUBSIDING IN EVENING.
MUCH COLDER AIR WILL ADVECT SOUTH INTO OUR CWA FOLLOWING FROPA
TONIGHT/WEDNESDAY. AFTER UNSEASONABLY WARM TEMPS EARLY THIS WEEK IN
THE 55 TO 60 DEGREE RANGE...TEMPS WILL PLUMMET CLOSER TO SEASONAL
NORMALS IN THE COLDER AIRMASS WITH LOW TO MID 30S EXPECTED. H85
TEMPS WHICH HAVE AVERAGED 7-C THE PAST COUPLE OF DAYS WILL PLUMMET
TO -8 TO -11C BY WED EVENING. VERY LITTLE DIURNAL TEMP RANGE IS
EXPECTED WEDNESDAY FM EARLY MORNING TEMPS IN THE UPPER 20S...AND
THIS WILL FEEL MARKEDLY COLDER WHEN COMBINED WITH THE STRONG
WINDS...AND APPARENT TEMPERATURES OR WIND CHILLS WILL AVERAGE IN THE
TEENS.
IN ADDITION TO THE MARKEDLY COLDER AIR AND STRONG WINDS...A DECENT
PERIOD OF FRONTOGENETIC FORCING BETWEEN H85 AND H5 IS PRESENT
BEGINNING TOWARD DAWN WEDNESDAY IN OUR NW CWA...WHICH SWEEPS SE WITH
FROPA. IN STRONG CAA/FRONTOGENESIS AND UPPER DYNAMICS AS
UPPER TROUGH MOVES IN WEDNESDAY...CANNOT RULE OUT POTENTIAL FOR SOME
LIGHT WINTRY PCPN. ATTM...MEASURABLE SNOWFALL IS NOT APPEARING
LIKELY HOWEVER DO THINK THERE WILL BE A TIME FRAME TOMORROW WHEN A
SNOW SHOWER OR FLURRIES ARE POSSIBLE. WILL TREND WITH OCCASIONAL
FLURRIES FOR NOW AND IF SNOW POTENTIAL LOOKS MORE SIGNIFICANT WITH
SUBSEQUENT RUNS...POPS CAN BE ADDED.
LONG TERM...WEDNESDAY EVENING THROUGH NEXT TUESDAY. PRIMARY
CHALLENGES INCLUDE FLURRY CHANCES EARLY ON...FOLLOWED BY TRYING TO
NAIL DOWN A BIT OF A TEMPERATURE ROLLER COASTER...AS THE
PERSISTENTLY MILD PATTERN ABATES FOR AT LEAST AWHILE. IN
ADDITION...CONCERNS ABOUT CRITICAL FIRE WEATHER CONDITIONS
CONTINUE TO GROW FOR THURSDAY...AND THIS IS EXCLUSIVELY COVERED
IN THE SEPARATE FIRE WEATHER SECTION BELOW.
STARTING OFF WEDNESDAY EVENING/NIGHT...THE CWA SHOULD BE SETTLING
DOWN A BIT FROM THE ADVISORY LEVEL WINDS OF THE DAYTIME
HOURS...BUT BY NO MEANS WILL NORTHWEST WINDS BE LIGHT THROUGH THE
NIGHT...AS SUSTAINED SPEEDS OF AT LEAST 15-25 MPH WITH HIGHER
GUSTS PREVAIL. ON THE LARGER SCALE ALOFT...12Z ECMWF/GFS/NAM ALL
DEPICT A SHARPENING...COLD TROUGH DROPPING SOUTH THROUGH THE HEART
OF THE CENTRAL PLAINS...WITH 850MB TEMPS CRASHING DOWN INTO THE
-13 TO -17C RANGE BY 12Z. STARTING WITH PRECIP CHANCES...OPTED TO
LEAVE RISK OF MEASURABLE SNOW BELOW 20 PERCENT...BUT KEPT CHANCE
OF FLURRIES GOING ACROSS MAINLY THE SOUTHEAST 1/3 OF THE CWA IN
THE EVENING...AND ACROSS MUCH OF THE EAST/NORTHEAST THROUGH THE
NIGHT. TRUTH IS...WITH SUCH A COLD POCKET ALOFT AND SHARP VORT MAX
PASSING OVERHEAD...PROBABLY JUST SHOULD HAVE ASSIGNED CHANCE OF
FLURRIES CWA-WIDE...BUT TRACK OF THE SYSTEM WOULD SUGGEST THAT
MUCH OF THE WESTERN CWA IS LEAST LIKELY TO SEE ANY FLAKES. BOTTOM
LINE IS...ANY LIGHT SNOW/FLURRIES WEDNESDAY NIGHT SHOULD BE VERY
MINIMAL IF IT EVEN OCCURS AT ALL. FOR LOW TEMPS...KEPT LOWS
SIMILAR TO PREVIOUS FORECAST...WITH 10-15 ACROSS MOST OF THE CWA.
THIS CONTINUES TO BE 4-5 DEGREES ABOVE MET/MAV GUIDANCE
CONSENSUS...WHICH JUST LOOKS TOO COLD GIVEN WINDS AND RESULTANT
MIXING STAYING UP. ALTHOUGH THE LOW TEMPS THEMSELVES ARE NOT ALL
THAT NOTABLE...WIND CHILL VALUES WILL DROP INTO THE ZERO TO -10
RANGE ACROSS MOST OF THE CWA WED NIGHT INTO THURS MORNING...WHICH
WILL BE QUITE A SLAP IN THE FACE.
THURSDAY...KEPT ALL FLURRY MENTION OUT FOR NOW...BUT WITH WESTERN
EDGE OF MID LEVEL LOW COLD CORE/CIRCULATION LINGERING CLOSE TO THE
EASTERN CWA...LATER SHIFTS WILL HAVE TO WATCH FOR FLURRY
POTENTIAL ALTHOUGH BETTER CHANCES WILL RESIDE FROM NORTHEAST NEB
INTO IA. TEMP WISE...THURS IS STILL LOOKING LIKE THE COLDEST DAY
SINCE AT LEAST DEC. 9TH FOR MOST OF THE CWA...AND CHANGED HIGHS
LITTLE RANGING FROM LOW 20S NORTHEAST TO NEAR 30 FAR SOUTHWEST.
MAIN CHANGE TO THURSDAY WAS RAISING WIND SPEEDS AT LEAST 5
MPH...AS CONTINUED SURFACE PRESSURE GRADIENT BETWEEN GREAT LAKES
LOW AND NORTHERN ROCKIES HIGH...ALONG WITH MIXING TO AT LEAST
850MB...WILL PROMOTE SUSTAINED NORTHWEST SPEEDS AT LEAST INTO THE
20-25 MPH RANGE MOST AREAS. ALTHOUGH NOT LOOKING LIKELY AT THIS
POINT...CAN/T EVEN RULE OUT SUSTAINED SPEEDS FLIRTING WITH
ADVISORY CRITERIA OF 30 MPH AND WILL NEED TO WATCH.
OTHERWISE...MODELS SUCH AS ECMWF/GFS CONTINUE TO INSIST THAT SOME
EXTREMELY DRY AIR WILL WORK ACROSS THE AREA...WITH SURFACE
DEWPOINTS POTENTIALLY FALLING UNDER -20F. ALTHOUGH HAVE NOT GONE
THAT LOW JUST YET...HAVE TRENDED DOWNWARD. BREEZES WILL BE A BIT
LIGHTER THURS NIGHT VERSUS WED NIGHT...BUT KEPT LOWS UP MAINLY
BETWEEN 9-14 DEGREES AS LACK OF SNOW COVER SHOULD PRECLUDE MORE OF
A DROP TOWARD ZERO.
FRIDAY/FRIDAY NIGHT...ECMWF/GFS ARE IN REASONABLE AGREEMENT WITH
THE MID/UPPER PATTERN...AS THE AFOREMENTIONED SYSTEM MOVES OFF
INTO THE EASTERN CONUS...BUT ANOTHER QUICK MOVING LOW AMPLITUDE
SHORTWAVE DROPS DOWN INTO THE REGION IN STRONG NORTHWEST FLOW
ALOFT. ANY RISK OF FLURRIES FRIDAY NIGHT LOOKS TO STAY AT LEAST A
FEW HUNDRED MILES NORTH/NORTHEAST OF THE CWA. FOR HIGH TEMPS
FRIDAY...WESTERLY LOW LEVEL FLOW RESULTS IN MODEST WARMING...AND
CHANGED HIGHS LITTLE WITH MID/UPPER 30S MOST AREAS...AND SOME LOW
40S SOUTHWEST.
SATURDAY/SAT NIGHT...MID LEVEL HEIGHTS STEADILY RISE AS BROAD
RIDGING OVERSPREAD MUCH OF THE WESTERN/CENTRAL CONUS...KEEPING IT
DRY. WITH A WEST/NORTHWEST DOWNSLOPE SURFACE WIND COMPONENT IN
PLACE...A CONTINUED MODEST WARMING TREND IS LIKELY...AND CHANGED
HIGHS LITTLE WITH LOW 40S NORTH TO UPPER 40S SOUTH.
SUNDAY/SUNDAY NIGHT...THIS IS STILL LOOKING LIKE THE WARMEST PART
OF THE FORECAST PERIOD...AS BOTH THE ECMWF/GFS NOW DEPICT STRONG
WARM AIR ADVECTION AT 850MB WITH TEMPS RISING INTO THE +8-12C
RANGE DURING THE DAY. ALTHOUGH SURFACE WINDS WILL BE MORE
SOUTHERLY THAN WESTERLY...KEPT TREND GOING FROM PREVIOUS FORECAST
OF AIMING ABOVE MODEL CONSENSUS FOR HIGH TEMPS...AND HAVE MOST OF
THE CWA IN THE 49-52 RANGE WITH SOME MID 50S POSSIBLE IN THE WEST.
MONDAY INTO TUESDAY...REASONABLE MODEL AGREEMENT CONTINUES FOR
6-7 DAYS OUT THAT THE NEXT BROAD TROUGH MOVING IN FROM THE WEST
WILL HELP DRIVE THE NEXT SIGNIFICANT COLD FRONT SOUTHWARD ACROSS
THE REGION. WITH THE MAIN PUSH OF COLD AIR LIKELY HOLDING OFF
UNTIL MONDAY NIGHT...OR AT LEAST LATER IN THE DAY...STILL HAVE
HIGHS REACHING THE LOW-MID 40S BUT THIS IS VERY DEPENDENT ON
FRONTAL TIMING AND IS SUBJECT TO MODIFICATION. ALTHOUGH SOME
LIGHT SNOW/FLURRIES CANNOT BE RULED OUT MON NIGHT INTO
TUESDAY...WILL KEEP OUT ALL PRECIP MENTION FOR NOW. BY TUESDAY
THIS NEXT BATCH OF COLD AIR SHOULD BE FIRMLY IN PLACE...AND HAVE
HIGHS RANGING UPPER 20S NORTHEAST TO MID 30S SOUTHWEST.
FIRE WEATHER...AS MENTIONED ABOVE...CONCERNS ARE INCREASING FOR A
SOMEWHAT RARE CRITICAL FIRE WEATHER SITUATION FOR THURSDAY.
THE RARITY IS BECAUSE AFTERNOON HIGH TEMPERATURES WILL ONLY BE IN
THE 20S ACROSS MOST OF THE CWA/DISTRICT...WHICH USUALLY IS TOO
COLD TO WARRANT A HIGH LEVEL OF FIRE WEATHER CONCERN.
HOWEVER...MODELS HAVE BEEN INSISTENT THAT EXTREMELY DRY AIR WILL
INVADE THE REGION...WITH SURFACE DEWPOINTS POTENTIALLY CRASHING TO
AROUND -20F DURING THE DAY. THE END RESULT IS THAT RELATIVE
HUMIDITY VALUES ARE NOW FORECAST TO DROP BELOW 20 PERCENT FOR AT
LEAST A FEW HOURS ESPECIALLY ACROSS THE WESTERN/CENTRAL CWA. THESE
LOW RH VALUES...COMBINED WITH SUSTAINED WINDS EASILY AT/OVER 20
MPH THROUGH THE DAY AND DRY VEGETATION...BRINGS RED FLAG WARNING
CRITERIA INTO PLAY...AND THIS WILL NEED CLOSELY MONITORED OVER THE
NEXT FEW DAYS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...WIND ADVISORY FROM 4 AM TO 6 PM CST WEDNESDAY FOR NEZ039>041-
046>049-060>064-072>077-082>087.
KS...WIND ADVISORY FROM 4 AM TO 6 PM CST WEDNESDAY FOR KSZ005>007-
017>019.
&&
$$
SHORT TERM...FAY
LONG TERM/FIRE WEATHER...PFANNKUCH
AVIATION...KING
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
310 PM EST WED JAN 11 2012
.SYNOPSIS...
A STRONG UPPER LEVEL STORM SYSTEM WILL MOVE ACROSS THE INLAND
CAROLINAS TODAY BRINGING WIDESPREAD SHOWERS AND EMBEDDED
THUNDERSTORMS. A WEAK COLD FRONT WILL FOLLOW THIS SYSTEM THIS
EVENING. A DEEP UPPER STORM SYSTEM FORMING OVER THE PLAINS WILL
PREVENT SIGNIFICANTLY COLD AIR FROM MOVING IN THURSDAY. A STRONG
COLD FRONT WILL DRIVE THROUGH THE CAROLINAS LATE THURSDAY BRINGING
A COLDER AND DRY WEEKEND. HIGH PRESSURE WILL MOVE OFF THE COAST
EARLY NEXT WEEK WITH TEMPERATURES RETURNING TO NORMAL.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 2 PM WEDNESDAY...WARM FRONT HAS MOVED TO A POSITION FROM
HVS TO BBP TO LBT TO EYF TO BACK ISLAND AND WILL MOVE N OF ALL
FORECAST POINTS BY 1930Z. DEWPOINTS HAVE RISEN INTO THE UPPER 50S
AND LOWER 60S IN THE WARM SECTOR. A VERY DYNAMIC SYSTEM WILL
AFFECT THE AREA LATE THIS AFTERNOON AND EVE. THE MAIN SURFACE LOW
WILL TRACK ALONG THE OHIO VALLEY THROUGH TONIGHT. A POTENT
SHORTWAVE ROTATING AROUND THE UPPER LOW WILL HELP TO DEVELOP A
SECONDARY AREA OF LOW PRESSURE WHICH WILL MOVE NE AND ACROSS THE
CAROLINA PIEDMONT THIS EVE. IN THE NARROW WEDGE BETWEEN THE WARM
FRONT TO N AND COLD FRONT TO W... THE AIRMASS WILL BE SLIGHTLY
UNSTABLE AND SHEAR WILL INCREASE... ESPECIALLY IN THE VICINITY OF
THE SECONDARY LOW AND WARM FRONT. AT THIS TIME...THE HIGHEST RISK
FOR ANY SEVERE WEATHER WOULD BE N AND NE OF THE FORECAST AREA
WHERE BETTER SHEAR AND INSTABILITY ALIGN. ONGOING CONVECTION
SHOULD LARGELY LIFT OUT THROUGH MID AFTERNOON. THEN A LINE OF
FORCED SHOWERS AND ISOLATED THUNDERSTORMS IS EXPECTED LATE
AFTERNOON AND EVE IMMEDIATELY AHEAD OF THE FRONT... FROM W TO E.
THE ACTUAL COLD FRONT WILL CLEAR THE COAST IN THE 02-04Z TIME
FRAME. LOW LEVEL JET OF 50 TO 60 KT WILL PEAK DURING THIS TIME
FRAME. THE LACK OF SIGNIFICANT SURFACE BASED INSTABILITY MAY MAKE
IT DIFFICULT FOR THESE HIGHER WINDS TO MIX TO THE SURFACE.
HOWEVER...STRONG GUSTY WINDS SHOULD BE ABLE TO MIX TO THE SURFACE
IN THE STRONGEST/DEEPEST CONVECTION GIVEN THAT DOWNDRAFT CAPE
VALUES ARE EXPECTED TO BE ABOVE 700 J/KG. MUCH NEEDED RAINFALL HAS
ALREADY FALLEN ACROSS A GOOD CHUNK OF THE AREA WITH A FEW SPOTS
REPORTING ABOUT A HALF INCH. TOTAL RAINFALL AMOUNTS IN THE ONE-
HALF TO ONE INCH RANGE ARE COMMONLY EXPECTED BEFORE THE PUNCH OF
DRY AIR REACHES THE AREA LATER THIS EVE. HIGHEST AMOUNTS WILL
LIKELY OCCUR NEAREST TO THE COAST.
DRIER AND SLIGHTLY COOLER AIR WILL PUNCH IN BEHIND THE COLD FRONT
TONIGHT AND SKIES WILL AT LEAST PARTIALLY CLEAR. EVE TEMPS WILL NOT
CHANGE MUCH AHEAD OF THE COLD FRONT. LOWS EARLY THU MORNING SHOULD
BE IN THE MID AND UPPER 40S WITH PERHAPS A FEW LOWER 50S HANGING ON
AT THE COAST.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 PM WEDNESDAY...POTENT LOW PRESSURE SYSTEM WILL BE LIFTING
OFF TO THE NORTH INTO NEW ENGLAND AS COLD FRONT MOVES OFF TO THE
NORTHEAST ON THURS. AS THIS ONE SYSTEMS MOVES OFF TO THE NORTHEAST
ANOTHER NORTHERN STREAM MID TO UPPER LOW WILL DIG DOWN INTO THE
SOUTHERN MISSISSIPPI VALLEY FROM THE GREAT LAKES. THIS WILL
MAINTAIN A DEEPER SOUTHWEST FLOW OUT AHEAD OF IT THROUGH THURS
WITH DRIER AIR WRAPPING AROUND INTO THE AREA IN STRONGER WINDS
ALOFT. PCP WATER VALUES DROP DOWN CLOSER TO A HALF INCH THROUGH
THE DAY. WILL MAINTAIN A WARMER FLOW WITH TEMPS REMAINING UP IN
THE 60S ON THURS.
BY THURS NIGHT AN ARCTIC FRONT WILL GET PUSHED THROUGH BY MID TO
UPPER TROUGH DIGGING DOWN INTO THE SOUTHEAST AS IT TRACKS EAST. LOW
LEVEL WINDS AHEAD OF THIS FRONT WILL BE UP NEAR 45 TO 50 KTS
HELPING TO PUSH MOIST GULF AND ATLANTIC AIR INTO THE COASTAL
CAROLINAS AHEAD OF THE FRONT THURS NIGHT. THIS WILL PRODUCE A
SPIKE IN PCP WATER UP NEAR AN INCH FOR A FEW HOURS. THE MAIN
ENERGY WITH THIS SYSTEM WILL REMAIN WEST OF LOCAL AREA BUT
NAM/GFS SHOWING A PIECE OF ENERGY RIDING AROUND THE MAIN TROUGH
RIGHT THROUGH ILM CWA SHORTLY AFTER MIDNIGHT AS FRONT MOVES
THROUGH. ADDED MORE CLOUDS TO FORECAST AND EXPECT WE MAY SEE A FEW
LIGHT AND SPOTTY SHOWERS AS THIS SYSTEM PUSHES THROUGH AND WILL
ADD A SLIGHT CHC FOR OVERNIGHT THURS.
ONCE THIS FRONT CLEARS THE AREA AND MID TO UPPER LOW LIFTS OFF ON
FRI...PLENTY OF DRY AND COOL AIR WILL MOVE IN AS HIGH PRESSURE
BUILDS IN FROM THE WEST. 850 TEMPS PLUMMET FROM AROUND 6 C THURS
NIGHT DOWN TO -4 C BY FRI MORNING. ALTHOUGH THE 850 TEMPS RECOVER
SLIGHTLY IN WESTERLY FLOW FRI AFTN...THE VALUES REMAIN BASICALLY
BELOW 0C THROUGH THE REMAINDER OF THE SHORT TERM INTO THE WEEKEND.
TEMPS WILL HAVE TROUBLE MAKING IT TO 50 ON FRI IN A COLD AND DRY
AIR MASS WITH PLENTY OF SUNSHINE. OVERNIGHT LOWS FRI NIGHT WILL
DROP BELOW FREEZING IN MOST PLACES IN CAA.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 300 PM WEDNESDAY...AMPLIFIED UPPER TROUGH CONTINUES ACROSS THE
EAST THROUGH MONDAY WITH WEAK UPPER IMPULSES ROTATING AROUND THE
BASE OF THE TROUGH. THESE IMPULSES PROVIDE REINFORCING SHOTS OF COLD
AIR EARLY SATURDAY AND A STRONGER ONE LATE SUNDAY AS ARCTIC HIGH
PRESSURE RIDGES DOWN FROM THE NORTH. HOWEVER...VERY DRY AIR AS
EVIDENCED BY PWATS LESS THAN ONE-HALF INCH WILL KEEP THE FORECAST
DRY WITH JUST BOUTS OF INCREASED CLOUD COVER. TEMPS WILL REMAIN
BELOW NORMAL...AROUND 50 SATURDAY AND MONDAY WITH MODERATE CAA...BUT
WARMING INTO THE LOWER TO MID 50S SUNDAY AS WINDS BRIEFLY BECOME SW.
MINS IN THE 20S EACH DAY...WITH MONDAY LIKELY BEING THE COLDEST
MORNING DUE TO BETTER RADIATIONAL COOLING.
BEYOND MONDAY...GUIDANCE AGREES THAT UPPER RIDGING WILL DEVELOP IN
RESPONSE TO HEIGHT FALLS ACROSS THE MIDDLE OF THE COUNTRY WHICH
RETURNS THE AREA TO ABOVE NORMAL TEMPERATURES BY TUESDAY.
THEREAFTER...MODELS DIVERGE IN EVOLUTION OF LEE-CYCLOGENESIS EAST OF
THE ROCKIES AND HOW THIS WILL IMPACT THE CAROLINAS. WILL FAVOR THE
ECMWF FOR CONSISTENCY WHICH HAS A MORE PROGRESSIVE SOLUTION...BUT
BOTH GFS/EURO DEPICT A COLD FRONT TRAILING THROUGH LATE TUE/EARLY
WED. MOISTURE RETURN ONCE AGAIN LOOKS LIMITED THIS FAR OUT. HAVE
BUMPED POP HIGHER...BUT STILL LOW ENOUGH TO KEEP THE EXTENDED DRY.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 18Z...THE HRRR MODEL WAS LEANED ON HEAVILY FOR THE FIRST SIX
HOURS OF TAF TIME. IT HAS BEEN FAIRLY CONSISTENT WITH A GOOD
CONVERGENCE BOUNDARY ALONG THE COAST. BEST CHANCE FOR GUSTY WINDS
AND HEAVY PRECIP WILL BE AT ILM...SECONDARILY THE MYRTLES. INLAND
TERMINALS WILL STILL SEE CONVECTION...JUST WITH LIGHTER PRECIP. LOOK
FOR INTERMITTENT IFR VISIBILITIES AT ILM IN THE HEAVIER SHOWERS.
COLD FRONT WILL APPROACH FROM THE WEST AFTER 02Z...WITH THE BOUNDARY
EXPECTED TO EXIT THE COAST BY 03-04Z. BEHIND THE FRONT...EXPECT
IMPROVING CONDITIONS WITH A WIND SHIFT TO THE WEST SOUTHWEST.
MODERATE MIXING AND COLD AIR ADVECTION WILL KEEP WINDS GUSTY FOR
MUCH OF THE NIGHT...DIMINISHING A BIT AFTER 08Z.
THURSDAY...VFR WITH SCATTERED SKIES AND CONTINUED WEST SOUTHWEST
FLOW...GUSTY AT TIMES.
EXTENDED OUTLOOK...VFR IS EXPECTED THROUGH THE EXTENDED.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 2 PM WEDNESDAY...SMALL CRAFT ADVISORY WILL REMAIN IN PLACE
INTO THU AFTERNOON. WINDS AND SEAS HAVE BEGUN TO INCREASE AS STRONG
COLD FRONT APPROACHES THE WATERS. THIS FRONT WILL MOVE ACROSS THE
WATERS 03-05Z TIME FRAME. WINDS WILL BE FROM THE S AHEAD OF THE
FRONT AND THEN VEER TO SW. STRONGEST WINDS WILL OCCUR THROUGH THIS
EVE...PEAKING RIGHT AHEAD OF THE FRONT AND THEN TRENDING LOWER
OVERNIGHT. SUSTAINED WINDS AS HIGH AS 25 KT MAY GUST FOR A TIME TO
AROUND 30 KT THIS EVE WITH EVEN HIGHER GUSTS IN THE VICINITY OF
STRONG CONVECTION. THE COOLER SHELF WATERS SHOULD HELP TO DAMPEN THE
STRONGEST OF WINDS AND MARINERS SHOULD BE AWARE THAT EVEN STRONGER
WINDS WILL OCCUR OFFSHORE WHERE WARMER SEA SURFACE TEMPS RESIDE.
SEAS WILL PEAK THIS EVE...IN THE 5 TO 8 FT RANGE...THEN SLOWLY
SUBSIDE AFTER MIDNIGHT. SEAS COULD REACH NEAR 10 FT OUT AROUND
FRYING PAN SHOALS BUOY.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 PM WEDNESDAY...AS ONE SYSTEM MOVES OFF TO THE NORTH
ANOTHER MID TO UPPER LOW WILL DIG DOWN MAINTAINING SOUTHWEST WINDS
THROUGH THURS. A TIGHTENED GRADIENT WILL PERSIST BETWEEN THESE
SYSTEMS AND HIGH PRESSURE BUILDING IN THROUGH THE MID WEST. EXPECT
WINDS TO MAINTAIN AROUND 20 KTS THURS. SW WINDS WILL INCREASE
FURTHER UP CLOSE TO 30 KTS AS THIS MID TO UPPER TROUGH PUSHES AN
ARCTIC FRONT THROUGH THE WATERS THURS NIGHT. STRONG SCA CONDITIONS
WILL EXIST AND WINDS MAY REACH UP TOWARD GALE FORCE OVERNIGHT
THURS INTO FRI MORNING. SEAS NEAR 4 TO 6 FT THURS WILL BUILD IN
RESPONSE TO THESE STRONG SW WINDS HEADING INTO THURS NIGHT. WNA
SHOWS MAX SEAS REACHING AROUND 10 FT NEAR FRYING PAN SHOALS.
OVERALL WILL KEEP SEAS UP TO 7 TO 9 FT IN LOCAL OUTER WATERS
HEADING INTO EARLY FRI MORNING.
ONCE FRONT MOVES OFF THE COAST FURTHER AN OFF SHORE FLOW WESTERLY
FLOW WILL DEVELOP. A COMBINATION OF CAA AND A TIGHTENED GRADIENT
FLOW MAY MAINTAIN SCA CONDITIONS THROUGH FRI NIGHT. SEAS WILL
BEGIN TO DIMINISH ON FRI MAINLY NEAR SHORE AS STRONG WESTERLY
WINDS PERSIST. BY FRI NIGHT SEAS SHOULD BE RUNNING AROUND 3 TO 5 FT.
LONG TERM/SATURDAY THROUGH MONDAY/...
AS OF 3 PM WEDNESDAY...SEAS INITIALLY OF 3-4 FT WILL FALL THROUGH
SATURDAY TO 1-2 FT AS NW WINDS EASE TO AROUND 10 KTS AND PUSH THE
HIGHEST WAVES WELL OFFSHORE. WINDS BACK TO THE WSW LATE SAT/EARLY
SUN AHEAD OF A SECONDARY COLD SURGE AND BEGIN TO INCREASE DUE TO
TIGHTENING GRADIENT. SEAS BUILD TO 3-5 FT AS WINDS INCREASE TO 20
KTS AND VEER BACK TO THE NW BEHIND A COLD SURGE LATE SUNDAY. WINDS
VEER FURTHER TO THE NORTHEAST AND SLOWLY DECREASE MONDAY AS HIGH
PRESSURE RIDGES DOWN THE COAST. WIND CHOP OF 3-4 FT WILL PERSIST
MONDAY...EXCEPT ONLY AROUND 1 FT IN THE SHADOWED AREA NEAR SHORE
BRUNSWICK AND HORRY COUNTIES.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR AMZ250-252-254-
256.
&&
$$
NEAR TERM...RJD
SHORT TERM...RGZ
LONG TERM...JDW
AVIATION...RJD/DL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
222 PM EST WED JAN 11 2012
.SYNOPSIS...
A STRONG UPPER LEVEL STORM SYSTEM WILL MOVE ACROSS THE INLAND
CAROLINAS TODAY BRINGING WIDESPREAD SHOWERS AND EMBEDDED
THUNDERSTORMS. A WEAK COLD FRONT WILL FOLLOW THIS SYSTEM THIS
EVENING. A DEEP UPPER STORM SYSTEM FORMING OVER THE PLAINS WILL
PREVENT SIGNIFICANTLY COLD AIR FROM MOVING IN THURSDAY. A STRONG
COLD FRONT WILL DRIVE THROUGH THE CAROLINAS LATE THURSDAY BRINGING
A COLDER AND DRY WEEKEND. HIGH PRESSURE WILL MOVE OFF THE COAST
EARLY NEXT WEEK WITH TEMPERATURES RETURNING TO NORMAL.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 2 PM WEDNESDAY...WARM FRONT HAS MOVED TO A POSITION FROM HVS
TO BBP TO LBT TO EYF TO BACK ISLAND AND WILL MOVE N OF ALL FORECAST
POINTS BY 1930Z. DEWPOINTS HAVE RISEN INTO THE UPPER 50S AND LOWER
60S IN THE WARM SECTOR. A VERY DYNAMIC SYSTEM WILL AFFECT THE AREA
LATE THIS AFTERNOON AND EVE. THE MAIN SURFACE LOW WILL TRACK ALONG
THE OHIO VALLEY THROUGH TONIGHT. A POTENT SHORTWAVE ROTATING AROUND
THE UPPER LOW WILL HELP TO DEVELOP A SECONDARY AREA OF LOW PRESSURE
WHICH WILL MOVE NE AND ACROSS THE CAROLINA PIEDMONT THIS EVE. IN THE
NARROW WEDGE BETWEEN THE WARM FRONT TO N AND COLD FRONT TO W... THE
AIRMASS WILL BE SLIGHTLY UNSTABLE AND SHEAR WILL INCREASE...
ESPECIALLY IN THE VICINITY OF THE SECONDARY LOW AND WARM FRONT.
AT THIS TIME...THE HIGHEST RISK FOR ANY SEVERE WEATHER WOULD BE N
AND NE OF THE FORECAST AREA WHERE BETTER SHEAR AND INSTABILITY
ALIGN. ONGOING CONVECTION SHOULD LARGELY LIFT OUT THROUGH MID
AFTERNOON. THEN A LINE OF FORCED SHOWERS AND ISOLATED THUNDERSTORMS
IS EXPECTED LATE AFTERNOON AND EVE IMMEDIATELY AHEAD OF THE FRONT...
FROM W TO E. THE ACTUAL COLD FRONT WILL CLEAR THE COAST IN THE
02-04Z TIME FRAME. LOW LEVEL JET OF 50 TO 60 KT WILL PEAK DURING
THIS TIME FRAME. THE LACK OF SIGNIFICANT SURFACE BASED INSTABILITY
MAY MAKE IT DIFFICULT FOR THESE HIGHER WINDS TO MIX TO THE SURFACE.
HOWEVER...STRONG GUSTY WINDS SHOULD BE ABLE TO MIX TO THE SURFACE IN
THE STRONGEST/DEEPEST CONVECTION GIVEN THAT DOWNDRAFT CAPE VALUES
ARE EXPECTED TO BE ABOVE 700 J/KG. MUCH NEEDED RAINFALL HAS ALREADY
FALLEN ACROSS A GOOD CHUNK OF THE AREA WITH A FEW SPOTS REPORTING
ABOUT A HALF INCH. TOTAL RAINFALL AMOUNTS IN THE ONE-HALF TO ONE
INCH RANGE ARE COMMONLY EXPECTED BEFORE THE PUNCH OF DRY AIR REACHES
THE AREA LATER THIS EVE. HIGHEST AMOUNTS WILL LIKELY OCCUR NEAREST
TO THE COAST.
DRIER AND SLIGHTLY COOLER AIR WILL PUNCH IN BEHIND THE COLD FRONT
TONIGHT AND SKIES WILL AT LEAST PARTIALLY CLEAR. EVE TEMPS WILL NOT
CHANGE MUCH AHEAD OF THE COLD FRONT. LOWS EARLY THU MORNING SHOULD
BE IN THE MID AND UPPER 40S WITH PERHAPS A FEW LOWER 50S HANGING ON
AT THE COAST.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 AM WEDNESDAY...COLD FRONT WILL BE NORTH AND EAST OF THE AREA
THU MORNING...THOUGH INITIALLY THERE WILL BE NO SIGN OF COLD AIR.
DIGGING 5H TROUGH OVER THE MISSISSIPPI VALLEY HELPS KEEP THE COLD
AIR TO THE WEST THU WITH STRONG SOUTHWEST FLOW PRODUCING 1 LAST DAY
WITH TEMPERATURES IN THE LOW TO MID 60S. ARCTIC COLD FRONT CROSSES
THE AREA LATE THU NIGHT WITH COLD ADVECTION ON ITS HEELS. LIMITED
MOISTURE RETURN AHEAD OF THE FRONT KEEPS FROPA DRY...THOUGH THERE IS
LIKELY TO BE AN INCREASE IN LOW CLOUDS WITH SOUNDINGS SHOWING
INCREASING MOISTURE THROUGH ABOUT 800 MB. THU NIGHT LOW WILL BE
TRICKY...MAINLY DEPENDENT ON TIMING OF THE FRONT/COLD AIR BUT
NUMBERS SHOULD END UP CLOSE TO CLIMO.
COLD AIR ARRIVES FROM THE WEST-SOUTHWEST ON THU NIGHT AND FRI AS
SEVERAL SHORTWAVES ROUND THE BASE OF THE 5H TROUGH THEN HEAD
NORTHEAST. HIGH FRI WILL STRUGGLE TO REACH 50S DESPITE SUNNY TO
MOSTLY SUNNY SKIES. WINDS STAY UP FRI NIGHT AS REINFORCING SHOT OF
COLD AIR ARRIVES LATE. LOWS WILL RANGE FROM UPPER 20S INLAND TO
AROUND 30 AT THE COAST.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 3 AM WEDNESDAY...AMPLIFIED UPPER PATTERN SAT/SUN WILL START
TRANSITIONING TO A PROGRESSIVE/FLAT PATTERN LATE IN THE PERIOD. AIR
MASS MODERATES A LITTLE SAT INTO SUN WITH DEEP WESTERLY FLOW. WINDS
MAY TURN SOUTHWEST LATE SAT NIGHT AND EARLY SUN BEFORE ANOTHER SHOT
OF COLD AIR ARRIVES DURING SUN...ASSOCIATED WITH CLIPPER SYSTEM
CROSS THE MID ATLANTIC. HIGH PRESSURE BUILDS IN FROM THE
WEST...SETTLING OVER THE AREA SUN NIGHT AND PRODUCING WHAT LOOKS TO
BE THE ONLY NIGHT OF REALLY GOOD RADIATIONAL COOLING. WITH UPPER
PATTERN FLATTENING OUT THE SURFACE HIGH IS QUICKLY PUSHED OFFSHORE
MON INTO TUE WITH RETURN FLOW DEVELOPING AND TEMPERATURES RETURNING
TO CLIMO.
00Z GFS/ECMWF CONTINUE TO CARRY A SURFACE SYSTEM BORN OF AN UPPER
WAVE CROSSING THE PLAINS EARLY NEXT WEEK. BOTH HAVE THE SURFACE
FEATURE AND 5H WAVE HEADING NORTH...THROUGH THE GREAT LAKES
REGION...BUT PUSH THE TRAILING COLD FRONT ACROSS THE AREA TUE. STILL
A LOT OF UNCERTAINTY WITH RESPECT TO TUE SO FOR NOW HAVE CONTINUED
THE INHERITED DRY TREND.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 18Z...THE HRRR MODEL WAS LEANED ON HEAVILY FOR THE FIRST SIX
HOURS OF TAF TIME. IT HAS BEEN FAIRLY CONSISTENT WITH A GOOD
CONVERGENCE BOUNDARY ALONG THE COAST. BEST CHANCE FOR GUSTY WINDS
AND HEAVY PRECIP WILL BE AT ILM...SECONDARILY THE MYRTLES. INLAND
TERMINALS WILL STILL SEE CONVECTION...JUST WITH LIGHTER PRECIP. LOOK
FOR INTERMITTENT IFR VISIBILITIES AT ILM IN THE HEAVIER SHOWERS.
COLD FRONT WILL APPROACH FROM THE WEST AFTER 02Z...WITH THE BOUNDARY
EXPECTED TO EXIT THE COAST BY 03-04Z. BEHIND THE FRONT...EXPECT
IMPROVING CONDITIONS WITH A WIND SHIFT TO THE WEST SOUTHWEST.
MODERATE MIXING AND COLD AIR ADVECTION WILL KEEP WINDS GUSTY FOR
MUCH OF THE NIGHT...DIMINISHING A BIT AFTER 08Z.
THURSDAY...VFR WITH SCATTERED SKIES AND CONTINUED WEST SOUTHWEST
FLOW...GUSTY AT TIMES.
EXTENDED OUTLOOK...VFR IS EXPECTED THROUGH THE EXTENDED.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 2 PM WEDNESDAY...SMALL CRAFT ADVISORY WILL REMAIN IN PLACE
INTO THU AFTERNOON. WINDS AND SEAS HAVE BEGUN TO INCREASE AS STRONG
COLD FRONT APPROACHES THE WATERS. THIS FRONT WILL MOVE ACROSS THE
WATERS 03-05Z TIME FRAME. WINDS WILL BE FROM THE S AHEAD OF THE
FRONT AND THEN VEER TO SW. STRONGEST WINDS WILL OCCUR THROUGH THIS
EVE...PEAKING RIGHT AHEAD OF THE FRONT AND THEN TRENDING LOWER
OVERNIGHT. SUSTAINED WINDS AS HIGH AS 25 KT MAY GUST FOR A TIME TO
AROUND 30 KT THIS EVE WITH EVEN HIGHER GUSTS IN THE VICINITY OF
STRONG CONVECTION. THE COOLER SHELF WATERS SHOULD HELP TO DAMPEN THE
STRONGEST OF WINDS AND MARINERS SHOULD BE AWARE THAT EVEN STRONGER
WINDS WILL OCCUR OFFSHORE WHERE WARMER SEA SURFACE TEMPS RESIDE.
SEAS WILL PEAK THIS EVE...IN THE 5 TO 8 FT RANGE...THEN SLOWLY
SUBSIDE AFTER MIDNIGHT. SEAS COULD REACH NEAR 10 FT OUT AROUND
FRYING PAN SHOALS BUOY.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 AM WEDNESDAY...DESPITE PASSAGE OF COLD FRONT WINDS REMAIN
WEST-SOUTHWEST WITH TIGHT GRADIENT KEEPING SPEEDS CLOSE TO 20 KT
THU. SPEEDS INCREASE THU NIGHT AS ARCTIC FRONT CROSSES THE WATERS.
STRONG COLD ADVECTION AND TIGHT GRADIENT IN THE WAKE OF THE FRONT
WILL KEEP SPEEDS OVER 20 KT AND GUSTY. WINDS EVENTUALLY BECOME
OFFSHORE FRI...BUT NOT BEFORE SEAS AREA ABLE TO BUILD CLOSE TO 10 FT
WELL AWAY FROM SHORE. SCA WILL LIKELY BE IN EFFECT INTO FRI
AFTERNOON AND POSSIBLY FRI EVENING FOR NC WATERS. ANOTHER SHOT OF
COLD AIR ARRIVES LATE FRI NIGHT WITH WEST WINDS SHIFTING TO
NORTHWEST...BUT REMAINING AROUND 15 KT...BY THE END OF THE PERIOD.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 3 AM WEDNESDAY...10 TO 15 KT WESTERLY FLOW SAT MAY BRIEFLY
BECOME SOUTHWEST SAT NIGHT BEFORE NEXT SURGE OF COLD AIR ARRIVES
SUN. ARRIVAL OF COLD AIR COINCIDES WITH PINCHED GRADIENT...FROM
APPROACH AND THEN PASSAGE OF CLIPPER SYSTEM TO THE NORTH...WHICH
INCREASES NORTHWEST WINDS TO 15 TO 20 KT. OFFSHORE COMPONENT SHOULD
KEEP SEAS WITH 20 NM IN THE 2 TO 4 FT RANGE...BUT SPEEDS ON SUN MAY
WARRANT A SCEC.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 1 PM EST
THURSDAY FOR AMZ250-252-254-256.
&&
$$
NEAR TERM...RJD
SHORT TERM...III
LONG TERM...III
AVIATION...DL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1155 AM EST WED JAN 11 2012
.SYNOPSIS...
A STRONG UPPER LEVEL STORM SYSTEM WILL MOVE ACROSS THE INLAND
CAROLINAS TODAY BRINGING WIDESPREAD SHOWERS AND EMBEDDED
THUNDERSTORMS. A WEAK COLD FRONT WILL FOLLOW THIS SYSTEM THIS
EVENING. A DEEP UPPER STORM SYSTEM FORMING OVER THE PLAINS WILL
PREVENT SIGNIFICANTLY COLD AIR FROM MOVING IN THURSDAY. A STRONG
COLD FRONT WILL DRIVE THROUGH THE CAROLINAS LATE THURSDAY BRINGING
A COLDER AND DRY WEEKEND. HIGH PRESSURE WILL MOVE OFF THE COAST
EARLY NEXT WEEK WITH TEMPERATURES RETURNING TO NORMAL.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 10 AM WEDNESDAY...A WARM FRONT HAS BEGUN TO MOVE ACROSS THE
AREA AND WILL MOVE N OF THE ENTIRE FORECAST AREA THROUGH EARLY
AFTERNOON. ISENTROPIC UPGLIDE WILL CONTRIBUTE TO THE DEVELOPMENT OF
SHOWERS. A VERY DYNAMIC SYSTEM ACROSS THE MID SOUTH WILL AFFECT THE
EASTERN CAROLINAS LATE THIS AFTERNOON AND EVE. THE MAIN SURFACE LOW
WILL TRACK ACROSS THE CENTRAL APPALACHIANS THIS AFTERNOON. A POTENT
SHORTWAVE ROTATING AROUND THE UPPER LOW WILL HELP TO DEVELOP A
SECONDARY AREA OF LOW PRESSURE ACROSS THE PIEDMONT OF NORTH
CAROLINA. IN THE NARROW WEDGE BETWEEN WARM FRONT TO N AND COLD FRONT
TO W...AIRMASS WILL BECOME SLIGHTLY UNSTABLE. SHEAR WILL INCREASE AS
WEAK SURFACE LOW DEVELOPS LATER THIS AFTERNOON AND EVE. THE
JUXTAPOSITION AND EVENTUAL TRACK OF THIS FEATURE WILL DETERMINE
WHERE ISOLATED SEVERE WEATHER WILL THREATEN. AT THIS TIME...THE
HIGHEST RISK FOR ANY SEVERE WEATHER WOULD BE N AND NE OF THE
FORECAST AREA WHERE BETTER SHEAR AND INSTABILITY LINE UP. A LINE OF
FORCED SHOWERS AND ISOLATED THUNDERSTORMS AHEAD OF THE COLD FRONT IS
EXPECTED LATE AFTERNOON AND EVE...FROM W TO E. THE ACTUAL COLD FRONT
WILL CLEAR THE COAST IN THE 02-04Z TIME FRAME. LOW LEVEL JET OF 50
TO 60 KT WILL BE PEAKING DURING THIS TIME FRAME. THE LACK OF SURFACE
BASED INSTABILITY WILL MAKE IT DIFFICULT FOR THESE HIGHER WINDS TO
MIX TO THE SURFACE. HOWEVER...STRONG GUSTY WINDS SHOULD BE ABLE TO
MIX TO THE SURFACE IN THE STRONGEST/DEEPEST CONVECTION. MUCH NEEDED
RAINFALL IS STILL IN THE FORECAST AND RAINFALL AMOUNTS IN THE
ONE-HALF TO ONE INCH RANGE ARE COMMONLY EXPECTED WITH THE BULK
ARRIVING IN THE LATE AFTERNOON AND EVE HOURS.
WARM FRONTAL PASSAGE SHOULD ALLOW ALL AREAS TO REACH THE LOWER TO
MID 60S THIS AFTERNOON...HIGHEST SW. DRIER AND SLIGHTLY COOLER AIR
WILL PUNCH IN BEHIND THE COLD FRONT TONIGHT AND SKIES WILL AT LEAST
PARTIALLY CLEAR. LOWS EARLY ON THU SHOULD BE IN THE MID AND UPPER
40S WITH PERHAPS A FEW LOWER 50S HANGING ON AT THE COAST.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 AM WEDNESDAY...COLD FRONT WILL BE NORTH AND EAST OF THE AREA
THU MORNING...THOUGH INITIALLY THERE WILL BE NO SIGN OF COLD AIR.
DIGGING 5H TROUGH OVER THE MISSISSIPPI VALLEY HELPS KEEP THE COLD
AIR TO THE WEST THU WITH STRONG SOUTHWEST FLOW PRODUCING 1 LAST DAY
WITH TEMPERATURES IN THE LOW TO MID 60S. ARCTIC COLD FRONT CROSSES
THE AREA LATE THU NIGHT WITH COLD ADVECTION ON ITS HEELS. LIMITED
MOISTURE RETURN AHEAD OF THE FRONT KEEPS FROPA DRY...THOUGH THERE IS
LIKELY TO BE AN INCREASE IN LOW CLOUDS WITH SOUNDINGS SHOWING
INCREASING MOISTURE THROUGH ABOUT 800 MB. THU NIGHT LOW WILL BE
TRICKY...MAINLY DEPENDENT ON TIMING OF THE FRONT/COLD AIR BUT
NUMBERS SHOULD END UP CLOSE TO CLIMO.
COLD AIR ARRIVES FROM THE WEST-SOUTHWEST ON THU NIGHT AND FRI AS
SEVERAL SHORTWAVES ROUND THE BASE OF THE 5H TROUGH THEN HEAD
NORTHEAST. HIGH FRI WILL STRUGGLE TO REACH 50S DESPITE SUNNY TO
MOSTLY SUNNY SKIES. WINDS STAY UP FRI NIGHT AS REINFORCING SHOT OF
COLD AIR ARRIVES LATE. LOWS WILL RANGE FROM UPPER 20S INLAND TO
AROUND 30 AT THE COAST.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 3 AM WEDNESDAY...AMPLIFIED UPPER PATTERN SAT/SUN WILL START
TRANSITIONING TO A PROGRESSIVE/FLAT PATTERN LATE IN THE PERIOD. AIR
MASS MODERATES A LITTLE SAT INTO SUN WITH DEEP WESTERLY FLOW. WINDS
MAY TURN SOUTHWEST LATE SAT NIGHT AND EARLY SUN BEFORE ANOTHER SHOT
OF COLD AIR ARRIVES DURING SUN...ASSOCIATED WITH CLIPPER SYSTEM
CROSS THE MID ATLANTIC. HIGH PRESSURE BUILDS IN FROM THE
WEST...SETTLING OVER THE AREA SUN NIGHT AND PRODUCING WHAT LOOKS TO
BE THE ONLY NIGHT OF REALLY GOOD RADIATIONAL COOLING. WITH UPPER
PATTERN FLATTENING OUT THE SURFACE HIGH IS QUICKLY PUSHED OFFSHORE
MON INTO TUE WITH RETURN FLOW DEVELOPING AND TEMPERATURES RETURNING
TO CLIMO.
00Z GFS/ECMWF CONTINUE TO CARRY A SURFACE SYSTEM BORN OF AN UPPER
WAVE CROSSING THE PLAINS EARLY NEXT WEEK. BOTH HAVE THE SURFACE
FEATURE AND 5H WAVE HEADING NORTH...THROUGH THE GREAT LAKES
REGION...BUT PUSH THE TRAILING COLD FRONT ACROSS THE AREA TUE. STILL
A LOT OF UNCERTAINTY WITH RESPECT TO TUE SO FOR NOW HAVE CONTINUED
THE INHERITED DRY TREND.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 17Z...THE HRRR MODEL WAS LEANED ON HEAVILY FOR THE FIRST SIX
HOURS OF TAF TIME. IT HAS BEEN FAIRLY CONSISTENT WITH A GOOD
CONVERGENCE BOUNDARY ALONG THE COAST. BEST CHANCE FOR GUSTY WINDS
AND HEAVY PRECIP WILL BE AT ILM...SECONDARILY THE MYRTLES. INLAND
TERMINALS WILL STILL SEE CONVECTION...JUST WITH LIGHTER PRECIP. LOOK
FOR INTERMITTENT IFR VISIBILITIES AT ILM IN THE HEAVIER SHOWERS.
COLD FRONT WILL APPROACH FROM THE WEST AFTER 02Z...WITH THE BOUNDARY
EXPECTED TO EXIT THE COAST BY 03-04Z. BEHIND THE FRONT...EXPECT
IMPROVING CONDITIONS WITH A WIND SHIFT TO THE WEST SOUTHWEST.
MODERATE MIXING AND COLD AIR ADVECTION WILL KEEP WINDS GUSTY FOR
MUCH OF THE NIGHT...DIMINISHING A BIT AFTER 08Z.
THURSDAY...VFR WITH SCATTERED SKIES AND CONTINUED WEST SOUTHWEST
FLOW...GUSTY AT TIMES.
EXTENDED OUTLOOK...VFR IS EXPECTED THROUGH THE EXTENDED.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 10 AM WEDNESDAY...WINDS SHOULD RAMP HIGHER IN THE WARM SECTOR
AHEAD OF THE COLD FRONT. THE COOLER SHELF WATERS SHOULD HELP TO
DAMPEN THE STRONGEST OF WINDS WHICH WILL BE OCCURRING OFFSHORE WHERE
WARMER SEA SURFACE TEMPS RESIDE. STILL...THE SYSTEM IS DYNAMIC AND
WITH A 50 TO 60 KT LOW LEVEL JET IMPINGING ON THE AREA LATER THIS
AFTERNOON AND THIS EVE...A SMALL CRAFT ADVISORY WILL REMAIN IN PLACE.
SOUTH WINDS WILL INCREASE TO 20 TO 25 KT LATER AFTERNOON AND PERSIST
INTO THIS EVE...VEERING TO SW IN THE WAKE OF THE COLD FRONT. SEAS
WILL BUILD QUICKLY AND WILL CONTINUE TO SHOW SEAS BUILDING TO 5 TO 8
FT ACROSS THE MAJORITY OF THE WATERS...HIGHEST BEYOND 10 NM.
WIND AND ESPECIALLY SEAS WILL SUBSIDE OVERNIGHT.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 AM WEDNESDAY...DESPITE PASSAGE OF COLD FRONT WINDS REMAIN
WEST-SOUTHWEST WITH TIGHT GRADIENT KEEPING SPEEDS CLOSE TO 20 KT
THU. SPEEDS INCREASE THU NIGHT AS ARCTIC FRONT CROSSES THE WATERS.
STRONG COLD ADVECTION AND TIGHT GRADIENT IN THE WAKE OF THE FRONT
WILL KEEP SPEEDS OVER 20 KT AND GUSTY. WINDS EVENTUALLY BECOME
OFFSHORE FRI...BUT NOT BEFORE SEAS AREA ABLE TO BUILD CLOSE TO 10 FT
WELL AWAY FROM SHORE. SCA WILL LIKELY BE IN EFFECT INTO FRI
AFTERNOON AND POSSIBLY FRI EVENING FOR NC WATERS. ANOTHER SHOT OF
COLD AIR ARRIVES LATE FRI NIGHT WITH WEST WINDS SHIFTING TO
NORTHWEST...BUT REMAINING AROUND 15 KT...BY THE END OF THE PERIOD.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 3 AM WEDNESDAY...10 TO 15 KT WESTERLY FLOW SAT MAY BRIEFLY
BECOME SOUTHWEST SAT NIGHT BEFORE NEXT SURGE OF COLD AIR ARRIVES
SUN. ARRIVAL OF COLD AIR COINCIDES WITH PINCHED GRADIENT...FROM
APPROACH AND THEN PASSAGE OF CLIPPER SYSTEM TO THE NORTH...WHICH
INCREASES NORTHWEST WINDS TO 15 TO 20 KT. OFFSHORE COMPONENT SHOULD
KEEP SEAS WITH 20 NM IN THE 2 TO 4 FT RANGE...BUT SPEEDS ON SUN MAY
WARRANT A SCEC.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 1 PM EST
THURSDAY FOR AMZ250-252-254-256.
&&
$$
NEAR TERM...RJD
SHORT TERM...III
LONG TERM...III
AVIATION...DL
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
826 PM CST THU JAN 12 2012
.UPDATED DISCUSSION...
SNOWFALL REPORTS CONTINUE TO TRICKLE IN THIS EVENING.
GENERALLY...ONE HALF TO ONE INCH AMOUNTS ACROSS THE FAR NORTHERN
TIER OF THE MID STATE. AREAS ALONG THE PLATEAU ARE ALSO SPORTING
ONE HALF TO 1 INCH AMOUNTS. RECENT RADAR TRENDS DID SHOW SOME
ENHANCEMENT MOVE ACROSS STEWART COUNTY AND WE DID GET A LOCAL
REPORT OF 1 TO 2 INCHES FOLLOWING THE BRIEF PERIOD OF HEAVIER
SNOWFALL.
OTW...LATEST RUC DATA STILL SHOWS THE SNOWFALL CUTTING OFF AROUND
06S TO THE WEST OF THE PLATEAU. LOOKING UPSTREAM...VSBYS ARE ALL
P6SM SO THIS IS LOOKING BELIEVABLE. FURTHERMORE...ECHO TRENDS
APPEARS TO BE WEAKENING TO OUR NORTHWEST.
RECEIVED A REPORT OF A 1 HOUR CLOSURE OF I-65 THROUGH MARSHALL
COUNTY DUE TO THE ROAD CONDITIONS. THUS...I HAVE UPDATED THE SPS TO
COVER ALL OF MIDDLE TN THROUGH THE OVERNIGHT. THE SPS WAS ISSUED
TO ADVISE OF THE DANGEROUS ROAD CONDITIONS DUE TO THE WINTRY PRECIP.
NO CHANGES TO THE ZONE FORECAST FOR NOW. I WILL UP THE SNOWFALL
GRIDS JUST BY ONE OR TWO TENTHS ACROSS THE STEWART COUNTY AREA.
OTW...EVERYTHING LOOKS OK FOR NOW.
.PREV DISCUSSION... /ISSUED 553 PM CST THU JAN 12 2012/
DISCUSSION...
AREAS OF SNOWFALL CONTINUE AT THIS HOUR ACROSS MUCH OF THE
NORTHERN HALF OF MIDDLE TN. SCATTERED SNOW SHOWERS ARE ALSO NOTED
ACROSS SOUTHERN AREAS. SNOWFALL REPORTS ARE SCATTERED AND ARE
GENERALLY UNDER 1 INCH SO FAR.
FIRST ORDER OF BUSINESS WILL BE TO ALLOW THE WIND ADVISORY TO
EXPIRE AT 6PM CST. LATEST WIND REPORTS THROUGHOUT THE CWA ARE AT
THE SUB ADVISORY LEVEL. THUS...WITH THE WEAKENING GRADIENT TREND
EXPECTED TO CONTINUE...WILL ALLOW THE WIND ADVISORY TO EXPIRE.
SECOND ORDER OF BUSINESS WILL INVOLVE THE DECREASE IN ZONE
GROUPINGS ACROSS THE CWA. WILL DO THIS SO AS TO ALLOW THE ZONE
TEXT SNOWFALL AMOUNTS TO MATCH THE GRAPHICS AND WSW THAT IS
CURRENTLY IN EFFECT.
AS OF NOW EXPECTED SNOWFALL TOTALS...SNOWFALL GRAPHIC AND THE CURRENT
WSW APPEARS TO BE ON TRACK. WILL ADJUST ZONES TO MATCH.
OTW...MUCH LESS SNOWFALL COVERAGE IS NOTED ON THE MEG RADAR. THIS
WILL LIKELY CALL FOR PRE MIDNIGHT WORDING IN TERMS OF OUR SNOWFALL
POTENTIAL. THE 6HR QPF RETURNS FROM THE MODELS LOOK TO CUT OFF
THE SNOWFALL TO THE WEST OF THE CUMBERLAND PLATEAU. THIS WILL NEED
TO BE REFLECTED IN THE UPCOMING UPDATE.
I WILL ALSO POINT OUT THAT AN SPS HAS BEEN ISSUED TO TO ADVISE THE
MID STATE AREA OF THE DANGEROUS ROAD CONDITIONS THAT ARE IN PLACE.
THOUGH THE ACCUMULATION POTENTIAL WILL LESSEN WITH TIME
OVERNIGHT...THE ROAD CONDITIONS MAY IN FACT WORSEN.
THAT`S ALL FOR NOW...I`LL FIRST UPDATE THE GRIDS AND THEN RUN THE
FORMATTERS. ZONES WILL THEN FOLLOW SHORTLY.
PREV DISCUSSION... /ISSUED 259 PM CST THU JAN 12 2012/
DISCUSSION...SURFACE MAP AT 21Z SHOWS COLD FRONT COMPLETELY
THROUGH MIDDLE TENNESSEE, WITH RAPID COLD ADVECTION TAKING PLACE
ACROSS THE MID STATE. HAVE ALREADY RECEIVED SEVERAL REPORTS OF
LIGHT SNOW AND ICE, MAINLY ON THE NORTH SIDE OF I-40. DEEPEST
MOISTURE HAS ALREADY PULLED EAST OF THE MID STATE, WITH REMAINING
MOISTURE CONFINED TO THE LOWEST 10 KFT. LATEST MODELS SHOW LOW-
LEVEL WRAP-AROUND MOISTURE CONTINUING TO CIRCULATE THROUGH THE MID
STATE OVERNIGHT AND EARLY TOMORROW MORNING. QPF`S ARE RELATIVELY
LOW, WITH THE HIGHEST AMOUNTS OCCURRING ALONG THE UPPER PLATEAU,
TAPERING OFF TO NEAR ZERO IN OUR SOUTHWEST. SNOW AMOUNTS UP TO AN
INCH ARE POSSIBLE ALONG THE HIGHLAND RIM AND AREAS JUST WEST OF
THE CUMBERLAND PLATEAU, WITH 1 TO 2 INCHES POSSIBLE ALONG THE
PLATEAU ITSELF. SNOW WILL TAPER OFF SIGNIFICANTLY AFTER MIDNIGHT,
SO WILL CONTINUE THE WSW UNTIL 06Z TONIGHT. TEMPERATURES WILL
CONTINUE THEIR FREE-FALL OVERNIGHT, DROPPING BELOW 20 DEGREES IN
MANY PLACES. THUS, WHATEVER PRECIPITATION DOES FALL LATE THIS
AFTERNOON AND OVERNIGHT WILL LIKELY FREEZE AND STAY FROZEN UNTIL
TOMORROW.
&&
.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE 20 32 21 45 / 50 0 05 05
CLARKSVILLE 19 31 19 45 / 50 0 05 05
CROSSVILLE 17 28 17 40 / 60 20 05 05
COLUMBIA 20 34 22 47 / 30 0 05 05
LAWRENCEBURG 20 35 22 50 / 20 0 05 05
WAVERLY 20 32 20 47 / 30 0 05 05
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR
TNZ005>011-028>034-063>066-077>080.
&&
$$
21
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
352 PM CST WED JAN 11 2012
.SHORT TERM...
THE SURFACE PRESSURE GRADIENT SUPPORTING TODAYS STIFF NORTHERLY
WINDS IS EXPECTED TO EASE STEADILY THIS EVENING...WITH DROP IN MOST
SURFACE WIND SPEEDS NEAR OR PRIOR TO 00Z THIS EVENING. OUR PLAN IS
TO ALLOW THE WIND ADVISORY TO RUN ITS COURSE UNTIL 00Z WITH NO
EXTENSION. WINDS PROBABLY WILL BE SLOWEST TO DROP THIS EVENING OVER
THE ROLLING PLAINS AND MAY RETAIN GREATER THAN 10 MPH WINDS UNTIL
CLOSE TO DAYBREAK ON THURSDAY. THIS SHOULD KEEP ESPECIALLY THE
SOUTHERN ROLLING PLAINS BETTER MIXED WHILE LOW TEMPERATURES
OTHERWISE TONIGHT SHOULD DROP INTO TEENS ON MOST OF THE CAPROCK AND
LOW TO MID 20S OVER ROLLING PLAINS. THE UPPER FLOW SHOULD REMAIN
SLIGHTLY ANTICYCLONICALLY CURVED IN NORTHWEST FLOW ALOFT WITH A
BRANCH OF THE POLAR JET STILL OVER THE AREA UNTIL MIDDAY THURSDAY.
THIS MAY LEAD TO AREAS OF MID CLOUDS AGAIN LATER TONIGHT AND/OR
THROUGH THURSDAY...THOUGH SOMEWHAT DIFFICULT TO ANTICIPATE. LOW
CLOUDS TONIGHT ALSO SOMEWHAT UNCERTAIN GIVEN PREDOMINANT NORTHERLY
LOW LEVEL FLOW AND VERY DRY AIR...THOUGH RUC INDICATES ABOUT 20
DEGREES MORE NORTHEAST COMPONENT AND MAINTAINS MORE H850 LAYER
MOISTURE ACROSS NORTHERN AND EASTERN ZONES. SO...APPEARS PERHAPS
BEST AREAS FOR MVFR LAYER LOW CLOUDS WOULD BE ACROSS NORTHEAST ZONES
BUT CANT RULE OUT FOR CENTRAL. EITHER WAY...A CHILLY NIGHT WILL
OCCUR WITH A FLATTER SURFACE PRESSURE GRADIENT DOMINATING THROUGH
MUCH OF THURSDAY. TRENDED HIGHS THURSDAY VERY SLIGHTLY UPWARDS ALONG
LINES OF GUIDANCE TRENDS AS WELL. RMCQUEEN
&&
.LONG TERM...
EXPECT DRY CONDITIONS AND MODERATING TEMPERATURES LATE WEEK ON
THROUGH THE WEEKEND. INITIALLY...A SHORTWAVE TROUGH EMBEDDED WITHIN
NORTHWESTERLY FLOW ALOFT WILL TRAVERSE THE AREA FRIDAY. THIS
DISTURBANCE WILL GENERATE AREAS OF MID/HIGH CLOUD BUT LITTLE ELSE.
THE NORTHWESTERLY FLOW WILL BACK WITH TIME WITH A PROGRESSIVE UPPER
RIDGE TRANSLATING OVER SATURDAY NIGHT AND SUNDAY. THIS
PATTERN...COMBINED WITH INCREASING SOUTHERLY/SOUTHWESTERLY LOW-
LEVEL FLOW...WILL PUSH HIGHS BACK ABOVE AVERAGE OVER THE WEEKEND
/LIKELY ECLIPSING THE 60 DEGREE MARK BY SUNDAY/. ONE MINOR CAVEAT
REVOLVE AROUND A CLIPPER SYSTEM DIVING INTO THE UPPER MIDWEST THAT
MAY ATTEMPT TO BACKDOOR A WEAK COLD FRONT INTO THE NORTHEAST ZONES
ON SATURDAY. EVEN IF THIS FRONT DOES MAKE IT INTO THE AREA...ONLY
MINOR IMPACTS ARE EXPECTED. THUS...HAVE TRENDED FORECAST
TEMPERATURES UP A NOTCH OVER THE WEEKEND.
ATTENTION WILL THEN TURN TO ANOTHER SHORTWAVE TROUGH /THE REMNANTS
OF THE CUTOFF LOW CURRENTLY SPINNING WELL OFF THE CALIFORNIA COAST/
THAT WILL RACE BY THE REGION IN NEAR ZONAL FLOW ALOFT ON MONDAY.
UNFORTUNATELY THE PROGRESSIVE AND OPENING/WEAKENING NATURE OF THE
SYSTEM...ALONG WITH THE DEARTH OF LOW-LEVEL MOISTURE TO WORK
WITH...WILL LIKELY KEEP THIS SYSTEM A DRY ONE LOCALLY. HOWEVER...IF
YOU LIKE WIND YOU MAY BE IN STORE FOR ANOTHER TREAT AS THE LATEST
GUIDANCE AND RAW NWP MODEL OUTPUT SUGGEST WESTERLY WINDS MAY
APPROACH OR EXCEED ADVISORY LEVELS DURING THE DAY MONDAY.
HENCE...HAVE TRENDED WINDS SPEEDS UPWARD IN THE GRIDS...THOUGH A
TOUCH BELOW ADVISORY LEVELS AT THIS POINT. THESE WINDS COULD ALSO
LOFT A BIT OF BLOWING DUST /LIKE TODAY/ AND ALSO ELEVATE THE FIRE
DANGER. HOWEVER...CURRENT PROJECTIONS DO KEEP HUMIDITIES ABOVE MORE
CRITICAL THRESHOLDS...THOUGH THIS COULD BE A BIT OPTIMISTIC AS IS
OFTEN THE CASE IN THE STRONG WESTERLY FLOW REGIME.
BEYOND MONDAY...A COLD FRONT IS PROGGED TO MOVE THROUGH EARLY
TUESDAY...DROPPING TEMPERATURES TOWARD MORE SEASONAL LEVELS. THE
LATEST ROUND OF MODEL SOLUTIONS HAVE TRENDED A LITTLE STRONGER WITH
THE FRONT...PUSHING IT THROUGH THE ENTIRE FA...AND HAVE FOLLOWED
SUITE IN THE GRIDS. THIS COOL-DOWN SHOULD BE RELATIVELY SHORT-LIVED
THOUGH AS THE SFC RIDGE IS QUICKLY SHUNTED EASTWARD UNDER MODERATE
TO STRONG MID-LEVEL ZONAL FLOW IN PLACE ACROSS MUCH OF THE CONUS.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 16 41 18 47 23 / 10 0 0 0 0
TULIA 17 42 17 49 22 / 10 0 0 0 0
PLAINVIEW 18 42 19 50 23 / 10 0 0 0 0
LEVELLAND 19 43 21 51 25 / 10 0 0 0 0
LUBBOCK 19 43 21 52 23 / 10 0 0 0 0
DENVER CITY 21 42 23 49 26 / 0 0 0 0 0
BROWNFIELD 22 43 23 50 25 / 0 0 0 0 0
CHILDRESS 23 45 20 53 24 / 10 0 0 0 0
SPUR 24 46 23 53 26 / 10 0 0 0 0
ASPERMONT 25 46 25 54 25 / 10 0 0 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR THE FOLLOWING
ZONES: TXZ021>044.
&&
$$
05/23
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
1156 AM CST WED JAN 11 2012
.AVIATION...
FOR THE 18Z TAFS...EXPECT MVFR CIGS TO PERSIST THRU THE AFTERNOON
HOURS AT ALL SITES IN RESPONSE TO COLD UPPER LEVEL STORM SYSTEM WHICH
IS FCST TO SWING BY TO THE NORTH OF THE TX AND OK PNHDLS. ONLY A FEW
SNOW FLURRIES ARE PSBL AT BEST ACROSS NRN TAF SITES. WINDS WILL ALSO
REMAIN STRONG THIS AFTERNOON...WITH AVIATION WEATHER WARNING IN
EFFECT FOR KAMA TIL 23Z TODAY. WINDS AND CLOUDS WILL SLOWLY DIMINISH
DURG THE COURSE OF THE EVENING HOURS WITH VFR CONDITIONS ANTICIPATED
BY LATE TONIGHT.
ANDRADE
&&
.PREV DISCUSSION... /ISSUED 601 AM CST WED JAN 11 2012/
AVIATION...
MAIN CONCERNS FOR THIS TAF CYCLE ARE STRONG WINDS AND MVFR CIGS.
COLD FRONT WILL MOVE THROUGH THE PANHANDLES THIS MORNING...WITH GUSTY
NORTHERLY WINDS IN ITS WAKE. THESE WINDS WILL INCREASE BETWEEN 14Z
AND 16Z...WITH 40 KNOTS POSSIBLE AT AMA INTO THE AFTERNOON. AWW WILL
CONTINUE AT AMA UNTIL 23Z. LATEST RUC FORECAST SOUNDINGS SHOW MVFR
CIGS HANGING AROUND UNTIL 00Z AND HAVE INCLUDED IN THE LATEST TAFS.
VFR CONDITIONS ANTICIPATED AFTER 00Z. NORTHERLY WINDS WILL ALSO
SUBSIDE BY 00Z...BUT GUST BETWEEN 20 AND 22 KNOTS UNTIL 06Z.
PREV DISCUSSION... /ISSUED 330 AM CST WED JAN 11 2012/
DISCUSSION...
COLD FRONT CURRENTLY THROUGH NORTHWESTERN KANSAS WILL MAKE ITS
PRESENCE KNOWN ACROSS PANHANDLES THIS MORNING. NORTH WINDS BEHIND
FRONT ARE EXPECTED TO REMAIN BELOW ADVISORY LEVELS. WIND CHILL
VALUES TODAY WILL REMAIN BELOW 32 DEGREES ACROSS ALL BUT FAR
SOUTHERN SECTIONS.
NO MEASURABLE PRECIPITATION IS EXPECTED TODAY...BUT HAVE INCLUDED
SCATTERED FLURRIES THIS AFTERNOON ACROSS NORTHERN SECTIONS...WHERE
POTENT VORTICITY MAXIMUM WILL TRAVERSE. NO PRECIPITATION IN
REMAINDER OF FORECAST.
WINDY CONDITIONS WILL END EARLY THIS EVENING...WITH CLEARING SKY
ALLOWING TEMPERATURES TO FALL INTO THE 10 TO 20 DEGREE RANGE AREA
WIDE. DEEP NORTHWEST FLOW ON THURSDAY WILL MAKE FOR ANOTHER COOL
DAY.
WARMING TREND BEGINS ON FRIDAY AS MID-LEVEL HEIGHTS RISE AND
SOUTHWEST SURFACE WINDS RESUME. WEAK COLD FRONT OR BRIEF WIND SHIFT
ON SATURDAY WILL HAVE MINIMAL IMPACT. DEEPENING SURFACE TROF SUNDAY
AND MONDAY EXPECTED TO RESULT IN MAXIMUM TEMPERATURES 10 TO 15
DEGREES ABOVE NORMAL. BACK DOOR COLD FRONT MONDAY NIGHT EXPECTED TO
PASS DRYLY...WITH COOLER CONDITIONS ON TUESDAY. 03
COCKRELL
FIRE WEATHER...
NORTH WINDS WILL DEVELOP THIS MORNING FOLLOWING THE PASSAGE OF A
STRONG COLD FRONT...BUT RELATIVE HUMIDITY VALUES WILL REMAIN WELL
ABOVE CRITICAL OR ELEVATED THRESHOLDS. NORTHWEST WINDS ON THURSDAY
WILL BE GUSTY MUCH OF THE DAY...AND THEN DIMINISH BY LATE
AFTERNOON. WINDS WILL BE MUCH LIGHTER FRIDAY AND SATURDAY.
SOUTHWEST WINDS INCREASE ON SUNDAY AND MONDAY...POSSIBLY RESULTING
IN ELEVATED FIRE WEATHER CONDTIONS ACROSS THE WESTERN HALF OF THE
FORECAST AREA. 03
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
601 AM CST WED JAN 11 2012
.AVIATION...
MAIN CONCERNS FOR THIS TAF CYCLE ARE STRONG WINDS AND MVFR CIGS.
COLD FRONT WILL MOVE THROUGH THE PANHANDLES THIS MORNING...WITH GUSTY
NORTHERLY WINDS IN ITS WAKE. THESE WINDS WILL INCREASE BETWEEN 14Z
AND 16Z...WITH 40 KNOTS POSSIBLE AT AMA INTO THE AFTERNOON. AWW WILL
CONTINUE AT AMA UNTIL 23Z. LATEST RUC FORECAST SOUNDINGS SHOW MVFR
CIGS HANGING AROUND UNTIL 00Z AND HAVE INCLUDED IN THE LATEST TAFS.
VFR CONDITIONS ANTICIPATED AFTER 00Z. NORTHERLY WINDS WILL ALSO
SUBSIDE BY 00Z...BUT GUST BETWEEN 20 AND 22 KNOTS UNTIL 06Z.
&&
.PREV DISCUSSION... /ISSUED 330 AM CST WED JAN 11 2012/
DISCUSSION...
COLD FRONT CURRENTLY THROUGH NORTHWESTERN KANSAS WILL MAKE ITS
PRESENCE KNOWN ACROSS PANHANDLES THIS MORNING. NORTH WINDS BEHIND
FRONT ARE EXPECTED TO REMAIN BELOW ADVISORY LEVELS. WIND CHILL
VALUES TODAY WILL REMAIN BELOW 32 DEGREES ACROSS ALL BUT FAR
SOUTHERN SECTIONS.
NO MEASURABLE PRECIPITATION IS EXPECTED TODAY...BUT HAVE INCLUDED
SCATTERED FLURRIES THIS AFTERNOON ACROSS NORTHERN SECTIONS...WHERE
POTENT VORTICITY MAXIMUM WILL TRAVERSE. NO PRECIPITATION IN
REMAINDER OF FORECAST.
WINDY CONDITIONS WILL END EARLY THIS EVENING...WITH CLEARING SKY
ALLOWING TEMPERATURES TO FALL INTO THE 10 TO 20 DEGREE RANGE AREA
WIDE. DEEP NORTHWEST FLOW ON THURSDAY WILL MAKE FOR ANOTHER COOL
DAY.
WARMING TREND BEGINS ON FRIDAY AS MID-LEVEL HEIGHTS RISE AND
SOUTHWEST SURFACE WINDS RESUME. WEAK COLD FRONT OR BRIEF WIND SHIFT
ON SATURDAY WILL HAVE MINIMAL IMPACT. DEEPENING SURFACE TROF SUNDAY
AND MONDAY EXPECTED TO RESULT IN MAXIMUM TEMPERATURES 10 TO 15
DEGREES ABOVE NORMAL. BACK DOOR COLD FRONT MONDAY NIGHT EXPECTED TO
PASS DRYLY...WITH COOLER CONDITIONS ON TUESDAY. 03
COCKRELL
FIRE WEATHER...
NORTH WINDS WILL DEVELOP THIS MORNING FOLLOWING THE PASSAGE OF A
STRONG COLD FRONT...BUT RELATIVE HUMIDITY VALUES WILL REMAIN WELL
ABOVE CRITICAL OR ELEVATED THRESHOLDS. NORTHWEST WINDS ON THURSDAY
WILL BE GUSTY MUCH OF THE DAY...AND THEN DIMINISH BY LATE
AFTERNOON. WINDS WILL BE MUCH LIGHTER FRIDAY AND SATURDAY.
SOUTHWEST WINDS INCREASE ON SUNDAY AND MONDAY...POSSIBLY RESULTING
IN ELEVATED FIRE WEATHER CONDTIONS ACROSS THE WESTERN HALF OF THE
FORECAST AREA. 03
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
10/03
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1128 PM CST TUE JAN 10 2012
.AVIATION...
CONCERNS...FOG POTENTIAL AROUND DAYBREAK.
WE/VE REMOVED IFR AND MVFR FOG FOR ALL SITES DUE TO THE EXPECTATION
THAT WESTERLY WINDS WILL REMAIN UP OVERNIGHT. IF WINDS GO CALM
FOR MORE THAN 2 HOURS...THEN 3-5SM BR OR GROUND FOG COULD FORM AND
LAST UNTIL 15Z. THE RUC MODEL WEAKENS SURFACE WINDS AROUND
DAYBREAK WHILE THE OTHER MODELS KEEP THEM UP 3-6KTS. WILL MONITOR
3.9 IR SATELLITE FOR DEVELOPMENT LATE TONIGHT.
A STRONG COLD FRONT TO PLOW THROUGH NORTH AND CENTRAL TEXAS LATE
WEDNESDAY AFTERNOON AND EARLY EVENING. FROPA FOR THE METROPLEX
TAF SITES WILL BE 23-00Z AND KACT BY 01Z. NORTHWESTERLY WINDS WILL
INCREASE TO 24G33KT SEVERAL HOURS BEHIND FROPA ACROSS THE
METROPLEX. IF GUSTS REACH 35 KTS OR HIGHER...A KDFW AIRPORT
WEATHER WARNING WOULD BE REQUIRED. 75
&&
.PREV DISCUSSION... /ISSUED 338 PM CST TUE JAN 10 2012/
BEST MID-LEVEL LAPSE RATES ARE NOW CONFINED TO ARKANSAS...AND
UPPER LOW HAS BEEN EFFECTIVELY CUT OFF FROM SUBTROPICAL PLUME. DRY
AIR CONTINUES TO ENTRAIN INTO THE CORE OF SYSTEM...AND SHOULD
LIMIT ADDITIONAL PRECIP TO SPRINKLES/DRIZZLE. UPPER LOW WILL REACH
EASTERN EXTENT OF THE FWD CWA AROUND NIGHTFALL.
DEEP SUBSIDENCE WILL FOLLOW TONIGHT...WITH WEAK SURFACE RIDGING
DIMINISHING WINDS. WITH CLEAR SKIES AND LIGHT WINDS...THE SURFACE
LAYER SHOULD QUICKLY SATURATE. SHALLOW FOG IS LIKELY AREAWIDE.
SUBTLE DRY ADVECTION FROM THE WEST SHOULD PREVENT WIDESPREAD DENSE
FOG...BUT THE VISIBILITY IS EXPECTED TO FALL BELOW ONE MILE AT
SOME LOCATIONS. THE SHALLOW NATURE OF THE FOG AND INCREASING
SOUTHWEST WINDS AHEAD OF APPROACHING FRONT SHOULD ALLOW FOG TO
DISSIPATE MORE EFFECTIVELY THAN TYPICAL JANUARY FOG EVENTS.
SUNNY SKIES AND DRYING DOWNSLOPE WINDS WILL BUOY TEMPERATURES INTO
THE 60S ON WEDNESDAY. THE MILD WEATHER WILL BE SHORT-LIVED AS COLD
FRONT WILL INVADE NORTHWEST PORTIONS OF CWA AROUND SUNSET. SURFACE
BOUNDARY IS CURRENTLY IN THE DAKOTAS...BUT WILL QUICKLY SPILL
SOUTH. WIND CHILLS WILL PLUMMET INTO THE TEENS BY DAYBREAK
THURSDAY. A BLUSTERY DAY WILL FOLLOW. AFTERNOON TEMPERATURES WILL
RETURN TO NORMAL BY SATURDAY.
A STRAY SHORTWAVE CURRENTLY OFF THE COAST OF SAN FRANCISCO WILL
CUT OFF. GUIDANCE CONTINUES TO STRUGGLE WITH EVOLUTION OF FEATURE
NEXT WEEK. ONCE THE LOW EJECTS...IT SHOULD BECOME AN OPEN WAVE
WHEN IT REACHES THE SOUTHERN PLAINS...THUS ANY RAIN EVENT WOULD
BE BRIEF. TO AVOID SPREADING 20 POPS THROUGHOUT AN EXTENDED
PERIOD...WILL MAINTAIN SHOWERS ONLY MONDAY AND MONDAY NIGHT...
DESPITE UNCERTAINTY IN TIMING.
25
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 37 65 31 45 28 / 10 0 0 0 0
WACO, TX 34 66 31 48 23 / 10 0 0 0 0
PARIS, TX 36 61 27 41 22 / 10 0 5 0 0
DENTON, TX 34 63 25 44 22 / 10 0 0 0 0
MCKINNEY, TX 35 62 30 43 22 / 10 0 0 0 0
DALLAS, TX 38 66 32 44 31 / 10 0 0 0 0
TERRELL, TX 36 66 31 45 24 / 10 0 0 0 0
CORSICANA, TX 37 66 32 46 26 / 10 0 0 0 0
TEMPLE, TX 34 68 30 46 23 / 5 0 0 0 0
MINERAL WELLS, TX 33 64 24 46 23 / 10 0 0 0 0
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
75/
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
225 PM CST WED JAN 11 2012
.SHORT TERM...
.TONIGHT AND THURSDAY...FORECAST CONFIDENCE HIGH.
DECIDED ON A WINTER WEATHER ADVISORY HEADLINE INSTEAD OF A WINTER
STORM WARNING DUE TO THE LONG DURATION OF THIS EVENT.
SFC WIND SHIFT AND COLD FRONT JUST GETTING INTO WEST CENTRAL WI THIS
AFTERNOON BRINGING INTIALLY JUST LOW CLOUDS. TIMING OF THIS FRONT
GETTING INTO SOUTH CENTRAL WI KEEPS TRENDING SLOWER.
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW 500MB LOW OVER
SOUTHEASTERN U.S. AND AN ELONGATED TROUGH DIPPING DOWN INTO THE
DAKOTAS. THE LONGWAVE TROUGH WILL BECOME A CLOSED 500MB LOW OVER
MO/IL BETWEEN 18Z THU AND 00Z FRI...WHICH WILL FURTHER DEEPEN AND
BECOME NEGATIVELY TILTED AS IT MOVES EAST INTO OHIO 06Z-12Z FRI.
EVEN THOUGH THE TWO UPPER LEVEL SYSTEMS WILL NOT MERGE...THE
MOISTURE WRAPPED INTO THE SOUTHEAST LOW WILL BE PULLED NORTHWESTWARD
INTO THE UPPER GREAT LAKES REGION. 285K TO 300K ISENTROPIC LIFT WILL
BRING AN EXTRA SURGE OF MOISTURE LIFT INTO LAKE MICHIGAN AND EASTERN
WI BETWEEN 18Z THU-06Z FRI. THIS WILL COMBINE WITH OMEGA VALUES OF
-5 TO -6 IN THE DENDRITIC GROWTH ZONE TO CREATE MODERATE SNOW AND
HALF INCH PER HOUR SNOWFALL RATES.
COLD TEMPS FLOWING INTO THE REGION WITH THE STRONG COLD FRONT WILL
BLOW THE SNOW AROUND THU AFTERNOON AND HELP TO KNOCK DOWN SNOW
RATIOS LATER THU AFTERNOON AND THU NIGHT. NAM SNOW RATIOS IN THE 14
TO 16:1 RANGE LOOK GOOD THROUGH 21Z THU...THEN CUT THE NAM RATIOS
DOWN A BIT TO STAY WITHIN THE 15 TO 17:1 RANGE THROUGH 06Z FRI.
IT/S IMPORTANT TO STRESS THAT THE CALCULATED SNOWFALL TOTALS OF 6 TO
8 INCHES WILL FALL OVER A VERY LONG TIME PERIOD FROM LATE TONIGHT
THROUGH EARLY FRIDAY AFTERNOON. THIS STORM TOTAL WAS DETERMINED BY
ADDING UP 6-HOURLY SNOWFALL GRIDS...AND DOES NOT REPRESENT HOW MANY
INCHES WILL BE ON A SNOW BOARD BY THE END OF THE EVENT. USE CAUTION
WHEN SITING THE STORM TOTAL SNOWFALL AMOUNTS!
THE BRUNT OF THE SNOW WILL COME BETWEEN MID THU MORNING AND MID THU
EVENING. THE MORNING COMMUTE IN MADISON WILL BE MESSY IF THIS STORM
KEEPS ITS CURRENT PACE. THE AFTERNOON COMMUTE WILL BE MESSY IN BOTH
MADISON AND MILWAUKEE WITH THE HIGHER SNOW RATES AND WIND BLOWING
THE SNOW AROUND. GIVEN THE LONG DURATION EVENT...SNOW PLOWS SHOULD
BE ABLE TO KEEP UP WITH THE SNOWFALL...WITH HIGHEST SNOW RATES OF A
HALF INCH PER HOUR FOR 4 TO 6 HOURS.
.THURSDAY NIGHT AND FRIDAY...FORECAST CONFIDENCE...MEDIUM
MID/UPPER TROUGH EXITS THE EASTERN GREAT LAKES REGION BY FRIDAY.
STRONG SURFACE LOW OVER LOWER MICHIGAN THURSDAY EVENING REACHES
THE EASTERN GREAT LAKES EARLY FRIDAY MORNING. ACCUMULATING SNOW
SHOULD CONTINUE THURSDAY EVENING...DIMINISHING BY FRIDAY MORNING.
12Z NAM/ECMWF SIMILAR IN PRECIPITATION AMOUNTS WITH THE GFS
SLIGHTLY LOWER.
LONG DURATION SNOW EVENT BUT APPEARS NO 12 HOUR PERIOD WILL REACH
6 INCHES AND 24 HOUR PERIOD WILL NOT REACH 8 INCHES SO WILL GO
WITH ADVISORY HEADLINES. WINDS/AND SOME BLOWING DRIFTING
SNOW...ESPECIALLY THURSDAY EVENING...BUT THIS NOT SEEM TO BE TOO
SEVERE TO WARRANT AN UPGRADE TO WARNING STATUS.
.LONG TERM...
.FRIDAY NIGHT AND SATURDAY......FORECAST CONFIDENCE...MEDIUM
SHORTWAVE IN THE NORTHWEST MID/UPPER LEVEL FLOW WILL MOVE ACROSS
THE NORTHERN PLAINS FRIDAY NIGHT AND MOVE ACROSS NORTHERN ILLINOIS
ON SATURDAY. ASSOCIATED WEAK SURFACE LOW IS EXPECTED TO TRACK
ACROSS NORTHERN ILLINOIS OR FAR SOUTHERN WISCONSIN. AN INCH OR
LESS OF SNOW POSSIBLE.
.SUNDAY THROUGH TUESDAY...FORECAST CONFIDENCE...MEDIUM
NORTHWEST MID/UPPER LEVEL FLOW SUNDAY UNTIL A RIDGE BUILDS INTO
WISCONSIN SUNDAY NIGHT AS A SHORTWAVE DIGS OVER THE WESTERN U.S.
AS A RESULT A SURFACE HIGH SHOULD EXTEND ACROSS THE GREAT LAKES.
SOUTH WINDS WILL INCREASE SUNDAY NIGHT AHEAD OF THE SURFACE TROUGH.
BY MONDAY MID/UPPER LEVEL FLOW BECOMES SOUTHWEST AS THE SHORTWAVE
MOVES EAST INTO THE ROCKIES/HIGH PLAINS REGION. BOTH THE 12Z GFS
AND 12Z ECMWF BRINGS A SURFACE TROUGH TO THE MISSISSIPPI VALLEY
WITH LIGHT PRECIPITATION SPREADING NORTH INTO SOUTHERN WISCONSIN.
BY THIS TIME THICKNESS VALUES RISE ABOVE 540 DM.
THE SHORTWAVE TROUGH SHOULD REACH THE UPPER MISSISSIPPI VALLEY
MONDAY NIGHT AND REACH THE GREAT LAKES ON TUESDAY. PRECIPITATION
SHOULD MIX WITH/CHANGE TO SNOW BEHIND THE SURFACE TROUGH/COLD FRONT.
PRECIPITATION WILL DIMINISH/END MONDAY NIGHT.
.TUESDAY NIGHT AND WEDNESDAY...FORECAST CONFIDENCE...MEDIUM
SURFACE HIGH BUILDS INTO WISCONSIN TUESDAY NIGHT BEFORE THE HIGH
MOVES ACROSS KENTUCKY.
&&
.AVIATION/00Z TAFS/...
VFR CONDITIONS EXPECTED THROUGH ABOUT 01Z AT KMSN AND 05Z AT KMKE
AND OTHER SE WI TAF SITES. WEDGE OF CLEAR SKIES BETWEEN SYSTEM TO
OUR SOUTH AND APPROACHING ONE TO THE NORTHWEST SHOULD LAST INTO THE
EARLY EVENING WITH SOME HIGH CLOUDS INITIALLY SPREADING IN. LOW
CLOUDS WITH MVFR CONDITIONS WILL SINK QUICKLY TO IFR IN THE WAKE OF
THE PASSING COLD FRONT BETWEEN 01-05Z THU. ANY SNOW AT KMSN SHOULD
HOLD OFF UNTIL AFTER 06Z THU AND AFTER 12Z THU AT KMKE.
INITIAL SNOW IS EXPECTED TO BE LIGHT...THEN THE BEST STORM DYNAMICS
MOVE ACROSS WI FROM WEST TO EAST 12-18Z THU AND REMAIN NEARLY
STATIONARY OVER SOUTH CENTRAL AND SOUTHEAST WI THROUGH 00Z TO 06Z
FRI AS SFC LOW PRESSURE REGROUPS OVER SOUTHEAST LOWER
MICHIGAN...OCCLUDES AND WAITS FOR THE 500MB UPPER LOW TO SHIFT
EASTWARD ACROSS ILLINOIS AND INDIANA.
TOTAL SNOW AMOUNTS UP TO 8 INCHES WILL FALL OVER A VERY LONG TIME
PERIOD...RUNNING FROM LATE TONIGHT THROUGH FRIDAY MORNING. THE
HEAVIEST PERIOD WOULD BE BETWEEN 18Z THU THROUGH 06Z FRIDAY WHERE UP
TO 4 INCHES COULD FALL.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY FROM 6 AM THURSDAY TO 6 AM CST FRIDAY
FOR WIZ047-057-063-068.
WINTER WEATHER ADVISORY FROM 9 AM THURSDAY TO 9 AM CST FRIDAY
FOR WIZ051-052-058>060-064>066-069>072.
WINTER WEATHER ADVISORY FROM 3 AM THURSDAY TO 6 AM CST FRIDAY
FOR WIZ046-056-062-067.
LM...SMALL CRAFT ADVISORY FROM 9 AM THURSDAY TO MIDNIGHT CST FRIDAY
NIGHT FOR LMZ643>646.
&&
$$
TONIGHT/THURSDAY AND AVIATION/MARINE...MRC
THURSDAY NIGHT THROUGH WEDNESDAY...HENTZ
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
255 AM EST FRI Jan 13 2012
.SYNOPSIS...
08Z water vapor and H4 RUC analysis shows an amplified upper level
pattern across the CONUS this morning. Main feature is longwave
troughing covering much of the county to the east of the continental
divide. Within this larger trough we find a closed upper low
spinning over the Ohio Valley and responsible for plenty of ongoing
winter precipitation from the Great Lakes to the NE states. The base
of this trough extends down to the northern Gulf coast and will
pivot across our region this morning. Early morning satellite
imagery shows areas of high level cirrus streaming across our skies
ahead of the trough axis and associated with upper level jet energy
aligned along the northern Gulf Coast.
At the surface,
Cold front which crossed the forecast area on Thursday continues to
move south and east over the FL peninsula. In the wake of this
front, a ridge of high pressure is building eastward along the Gulf
coast delivering a cooler and drier airmass. Temperatures will
continue a slow slide downward through the pre-dawn hours reaching
the lower/middle 30s by sunrise to the NW of a PC to Tallahassee to
Valdosta line, and upper 30s to low 40s further south and east.
&&
.SHORT TERM (TODAY THROUGH SUNDAY)...
Today,
High pressure centered over Texas will continue to ridge eastward to
our region through the day. The ridge will supply us with a fair,
dry, and cool forecast to end the work week. Will call it mostly
sunny, however there will be some passing cirrus this morning across
the Big Bend zones, and then additional cirrus arriving from the
west late in the day ahead of yet another mid-level shortwave. With
CAA ongoing this morning, temperatures will be slow to respond.
850mb temps will be lowering through the day, with the 0C line
dipping down close to KDHN and KABY. With this cooler low level
airmass in place, expecting high temperatures by mid afternoon to
generally reach the lower 50s (middle 50s down toward KCTY).
Tonight,
Gradient will weaken as the ridge axis continue to build closer to
the region. In terms of a radiational cooling setup, the high
position is certainly not ideal, however it isn`t terrible either.
It is likely that de-coupling of the boundary layer will eventually
take place, although it may take much of the night to occur. With
this in mind, do not anticipate much in the way of hard freeze
conditions, however much of the forecast area will experience
sub-freezing temperatures during the late night hours. Normally
colder locations under radiational cooling will briefly drop down
into the middle 20s around sunrise, with most other spots bottoming
out in the upper 20s to lower 30s.
Saturday/Sunday,
After the cold start Saturday morning, high pressure building
overhead will provide the region with a dry and seasonable weekend.
Airmass will begin to recover during Saturday as the longwave
mid-level trough begins to pull away to the NE. High temperatures
will respond, reaching the upper 50s for afternoon highs. The
overall airmass will not be as cool Saturday night, however the
surface high will be almost directly over the forecast area. This
more favorable high position combined with plenty of residual dry
air will allow for a good radiational cooling setup. Expecting
widespread low temperatures by sunrise to reside between 30-35
degrees. Normally colder spots...especially along the I-10 corridor
and Suwannee River Valley will have the potential to briefly reach
the upper 20s. Temperatures rebound further on Sunday after the cold
start, with 850mb temps climbing to 6-8C by the end of the day. With
the high position in close proximity, overall diurnal mixing will be
held in check, but should still be able to mix out our afternoon
temps into the lower/mid 60s.
&&
.LONG TERM (MONDAY THROUGH NEXT FRIDAY)...
The large scale longwave pattern commences fairly amplified. This is
highlighted in the Nrn stream by weak troughing across Wrn states
and extreme Wrn Atlc and ridging in between. Srn stream with weak
troughing Pac Coast to TX and ridging Ewd into extreme Wrn Atlc. At
surface, high along NC/VA coast with ridge axis swwd into
Apalachee Bay. Low in Canada N of MN with cold front Swwd into
Colorado. This place local area in very dry pattern.
During the rest of the period, Wrn upper trough digs Ewd while Srn
stream upper ridge moves offshore with Srn flow becoming nearly
zonal and stays so before weak troughing approaches shifting flow to
SWLY on Fri. At surface, Ewd moving UPR Nrn trough pushes surface
low moves to Srn Great Lakes kicking high into Atlc. Assocd cold
front dragged rapidly Sewd with deep sly flow setup from Gulf. Front
pushed thru CWA Tues night exiting Wed morn Ern zones bringing sct
shwrs and isold tstms Tues into Wed. In its wake strong high builds
SEWD from Srn Plains Ewd spreading a reinforcing shot of cold and
very dry air across local region Wed into Fri. By end of period high
pushed offshore with next low moving newd into TN valley dragging
trailing cold front to Wrn Gulf. In response, onshore flow with
increasing chances of rain commences again across local area by end
of Fri.
Forecast will show Sct pops Tues aftn into Wed. Otherwise nil pops
thru period. Ahead of the front min temps will be around 10 degrees
above climo Mon and Tues nights dropping to at or below climo Wed
and Thurs nights and may reach freezing in coldest locales. Max
temps commence at least 10 degrees above climo on Tues dropping to
at or below climo on Wed then inching up to a few degrees above
climo by Fri. Average inland min/max temps are 39/62.
&&
.MARINE
A ridge of high pressure will begin to build over the forecast
waters today in the wake of a cold front. Advisory level northwest
winds will diminish through the day, and expect the current advisory
to be dropped later this morning or early this afternoon. After a
round of cautionary level winds tonight, high pressure will build
overhead for much of the weekend keeping winds and seas below
headline criteria. Winds will begin to pick up once again out of the
east and southeast early next week as the ridge of high pressure
exits the region.
&&
.AVIATION (THROUGH 06Z SATURDAY)...
Wind speeds will continue to be in the 10 kt range and locally gusty
until 09z before diminishing to around or under 10kts until it
becomes near calm after sunset. Aside from a scattering of low level
clouds, expect only cirrus to stream over the region thru 06z Sat.
&&
.FIRE WEATHER...
A very dry airmass will settle in across the region through
Saturday, with RH values dropping into the lower 20s each afternoon.
Durations of critical RH will be right around 4 hours across SE
AL/SW GA for both days with driest values across SE ALA and SW GA. A
Red Flag warning has been issued for the SE ALA/GA counties for this
afternoon. Altho critical RH values will be realized over N FL,
neither ERC, winds or dispersion red flag values will be realized so
no warning was issued. Similar conditions are expected on Saturday
and a fire weather watch remains in effect for the GA/AL counties.
The airmass will slowly moisten Sun thru Tues then dry out again on
Wed into Thurs in the wake of a cold front.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 52 27 58 29 65 / 0 0 0 0 0
Panama City 53 34 59 38 63 / 0 0 0 0 0
Dothan 51 29 59 33 62 / 0 0 0 0 0
Albany 51 27 58 31 61 / 0 0 0 0 0
Valdosta 52 27 57 31 61 / 0 0 0 0 0
Cross City 56 27 59 30 65 / 0 0 0 0 0
Apalachicola 52 35 57 34 63 / 0 0 0 0 0
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
AL...Red Flag Warning from Noon today to 4 PM CST this afternoon for
Coffee-Dale-Geneva-Henry-Houston.
Fire Weather Watch Saturday afternoon for Coffee-Dale-Geneva-
Henry-Houston.
GA...Red Flag Warning from 1 PM to 5 PM EST this afternoon for Baker-
Ben Hill-Berrien-Brooks-Calhoun-Clay-Colquitt-Cook-Decatur-
Dougherty-Early-Grady-Irwin-Lanier-Lee-Lowndes-Miller-
Mitchell-Quitman-Randolph-Seminole-Terrell-Thomas-Tift-
Turner-Worth.
Fire Weather Watch Saturday afternoon for Baker-Ben
Hill-Berrien-Brooks-Calhoun-Clay-Colquitt-Cook-Decatur-
Dougherty-Early-Grady-Irwin-Lanier-Lee-Lowndes-Miller-
Mitchell-Quitman-Randolph-Seminole-Terrell-Thomas-Tift-
Turner-Worth.
FL...None.
GM...Small Craft Advisory until Noon EST today for Apalachee Bay-
Coastal waters From Ochlockonee River to Apalachicola FL
out to 20 NM-Coastal waters from Suwannee River to Keaton
Beach FL out 20 NM-Coastal waters from Apalachicola to
Destin FL out 20 NM-Waters from Suwannee River to
Apalachicola FL from 20 to 60 NM-Waters from Apalachicola
to Destin FL from 20 to 60 NM.
&&
$$
SYNOPSIS/SHORT TERM/MARINE...MROCZKA
LONG TERM/AVIATION/FIRE WX...BLOCK
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
414 AM EST FRI JAN 13 2012
.SHORT TERM...
MID LVL DEFORMATION ZONE CONTS TO PIVOT EWD ACRS CWA THIS MORNING IN
RESPONSE TO UPR LOW LIFTING OUT OF ERN OH. BROAD/DEEP MSTR PLUME
REMAINS ENTRENCHED UPSTREAM WITHIN DEEP CYCLONIC FLW OVR THE WRN
LAKES AND WHICH PRESENTS SOMEWHAT OF A PROBLEM GOING FORWARD THROUGH
THIS MORNING. SNOWFALL ACCUMS SO FAR RANGE FM 3-4 INCHES NORTHWEST
TO LESS THAN 1 INCH ERN HALF THANKS SOLELY TO MID LVL DRY SLOT THAT
WRAPPED IN ALG ERN SIDE OF CLOSING MID LVL CIRC YDA. HWVR SFC TROUGH
HAS PIVOTED INLAND ACRS BERRIEN/LAPORTE COUNTIES AS OF 09Z AND
RESULTED IN A SEQUENTIAL BLOSSOMING IN HIGHER RADAR RTNS OF
25-30 DBZ INDICATING WIDESPREAD MOD-HVY SNOW ONGOING NOW GENERALLY
ALG A LINE FM KIRS...KASW...KRCR. XPC FURTHER CONSOLIDATION
/DEFINITION TO LK BANDS BTWN NOW AND 15Z AS LL WIND FIELD BECOMES
BTR DEFINED AND OBSVD IN RECENT RADAR TRENDS. IN ADDN...INLAND THERMAL
MODIFICATION HAS BEEN QUITE ROBUST W/5-10 DEGREES WARMING NOTED
OVERNIGHT AND SHLD CONT TO PROMOTE INTENSE LL FRONTOGENESIS ESP INLAND
THROUGH THIS AFTN AND THEREIN LIES THE BIGGEST PROBLEM. MIX OF
00Z-06Z HIGHRES GUIDANCE WAVERS CONSIDERABLY ON PLACEMENT OF SRN
EDGE OF LK ENHANCEMENT THIS MORNING BFR GIVING AWAY TO PURE LK
EFFECT BY THIS AFTN W/AN IMPLIED ADDNL 3-4 INCHES OF SNOW FM
12-00Z. PRIOR 00-03Z RUC FCST TREND LOOKED CLOSE UPSTREAM YET WAS
TOO FAR EAST W/ALIGNMENT AT 06Z AND TOO PROGRESSIVE. HWVR 06Z FCST
OFF EVEN FURTHER. NAM12 LIES MIDWAY BTWN NMM/ARW SOLUTIONS SO A
COMBO OF THOSE THREE SHLD SUFFICE THROUGH AFTN BFR SWITCHING TO
BLENDED HIGHRES PLACEMENT. THUS NRN 2 TIERS OF WARNING WILL CONT
THROUGH 00Z W/LIKELY EXTENSION NEEDED THIS EVENING PENDING PRIMARY
LK BAND EVOLUTION THROUGH THIS MORNING. THIS REMAINS QUITE
UNCERTAIN...AND TIED TO WHETHER ERN BAND THROUGH CASS/ST
JOE/LAGRANGE OR WRN BAND THROUGH LAPORTE/ST JOE/ELKHART DOMINATES
AND LTL DEFINITIVE SIGNAL SEEN YET IN OBSVNL TRENDS THIS MORNING
TO GIVE A NOD ONE WAY OR THE OTHER.
AS FOR HIGHLIGHTS...SRN WARNING SEGMENT CONSISTING OF
STARKE/MARSHALL/KOSCIUSKO WILL BE DOWNGRADED. WILL HOLD
W/ADVISORY AREA AS LARGER AREA OF SYNOPTICALLY ENHANCED SHSN
WORKS THROUGH THE AREA THIS MORNING W/GENERAL 1-2 INCHES ADDNL
XPCD THROUGH 18Z. HWVR SW ZONES WILL LIKELY BE DROPPED AT SOME
POINT PRIOR TO EXPIRATION.
PRIMARY LK BAND THROUGH SW MI INTO NRN IN PROGGED TO REMAIN QUITE
INTENSE INTO THIS EVENING AND WILL LIKELY ADD ANOTHER 1-3 INCHES
HWVR ERODING INVERSION HGTS AND GENERAL DRYING ALOFT SUGGEST
INTENSITY WILL BE LIMITED W/GREATER ACCUMS CONFINED TO
LAPORTE/BERRIEN AND CASS. OTHERWISE SFC GRADIENT WKNS RAPIDLY LT
THIS AFTN W/BLSN ENDING.
UPSTREAM CLIPPER PUSHING THROUGH WRN ALBERTA THIS MORNING WILL DIVE
QUICKLY SEWD TONIGHT AND INTO THE OH VALLEY SAT AFTN. CERTAINLY A
LACK OF MSTR OVERTOP RETREATING ARCTIC WEDGE HWVR GOING GRIDDED POPS
LOOK REASONABLE AND MAINTAINED. PRIMARY CHG WAS TO BLEND TWD COLDER
MOS SPLIT ON MAX TEMPS.
&&
.LONG TERM.../SUNDAY THROUGH THURSDAY/
UPPER LEVEL FLOW WILL AMPLIFY SOMEWHAT FOR THE START OF THE NEW
WEEK. THIS WILL ALLOW FOR MODERATING TEMPERATURES BACK TO NEAR OR
ABOVE NORMAL LEVELS BEFORE THE NEXT TROUGH BRINGS PRECIP AND COLDER
WEATHER BACK TO THE AREA.
RAPID WAA WILL BE UNDERWAY DURING THE DAY SUNDAY AS 850 MB TEMPS
CLIMB A GOOD 5 TO 10 DEGREES C REACHING TO +2 TO -3 C BY SUNDAY
EVENING. EVEN WARMER TEMPS WILL BE ADVECTED IN SUNDAY NIGHT INTO
MONDAY AS LL FLOW RAMPS UP ALLOWING FOR MOST AREAS TO +3 TO +6 C IN
THE LOW LEVELS BY MONDAY EVENING. CONCERNS FOR SEEING THESE WARMER
TEMPS AT THE SURFACE REMAIN AS A RESULT OF COMBINATION OF AT LEAST
SOME SNOWPACK /ALTHOUGH MAYBE NOT AS MUCH AS ORIGINALLY THOUGHT/ AND
INCREASING CLOUD COVER ASSOCIATED WITH THE APPROACHING SYSTEM. HAVE
OPTED TO HAVE FEW CHANGES TO TEMPS SUNDAY AND MONDAY FOR THE TIME
BEING. LIGHT PRECIP IS STILL POSSIBLE AS LL MSTR WILL INCREASE AND
AT LEAST SOME LOW LEVEL LIFT WILL TAKE PLACE. IF PRECIP WAS TO
ARRIVE FAST ENOUGH MONDAY MORNING...THERE COULD BE A PERIOD OF
FREEZING PRECIP...BUT TEMPS SHOULD CLIMB FAIRLY QUICK ABOVE FREEZING
AND KEEP THIS THREAT TO A MINIMUM.
BEST CHANCE FOR RAINFALL WILL BE MONDAY NIGHT AS COLD FRONT
APPROACHES THE AREA WITH LOW PRESSURE TRACKING ALONG IT. CONFIDENCE
IN ANY ONE MODEL SOLUTION NOT VERY HIGH WITH NORMALLY FAVORED ECMWF
FLIP FLOPPING BETWEEN NORTHERN ENERGY REMAINING STRONGER WITH SFC
LOW ACROSS NORTHERN GREAT LAKES...AND SOUTHERN ENERGY STRENGTHENING
ALLOWING FOR DEEPENING LOW PRESSURE OVER THE FORECAST AREA ON
TUESDAY. WILL MAINTAIN LIKELY POPS MONDAY NIGHT AND HIGHER END POPS
CHC TO LOW END LIKELY TUESDAY FOR CONSISTENCY SAKE. PTYPE SHOULD BE
ALL RAIN MONDAY NIGHT BUT COULD BE RAIN OR MIX OF RAIN/SNOW ON
TUESDAY DEPENDING ON TRACK OF SFC LOW. RUSH OF COLD AIR WILL ARRIVE
ONCE AGAIN WITH TEMPS FALLING BACK BELOW NORMAL INTO THE 20S AND
REMAINING THAT WAY THROUGH THE REMAINDER OF THE PERIOD. YET ANOTHER
DISTURBANCE WILL ARRIVE FOR WEDS NGT INTO THURS BRINGING ANOTHER
CHANCE FOR SNOW.
&&
.AVIATION...
DIFFICULT NR TERM AS LK ENHANCEMENT GIVES WAY TO PURE LK EFFECT SHSN.
XPC POOR FLIGHT CONDS TO CONT AT KSBN INTO THIS AFTN ESP IN LIGHT
OF LL WIND FIELD REORGANIZING THIS MORNING AND SIGNS OF RENEWED LK
BAND DVLPMNT. 06Z ISSUANCE LOOKS ON TRACK LIFR CONDS EARLY ON
GIVING WAY TO IFR UNTIL LT THIS AFTN. INTENSE SFC GRADIENT THIS
MORNING WILL CONT THROUGH MID AFTN BFR DIMINISHING. OTHERWISE
IMPROVING CONDS TO MVFR XPCD THIS EVENING.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER WEATHER ADVISORY UNTIL 1 PM EST /NOON CST/ THIS AFTERNOON
FOR INZ012>018-020-022>027-032>034.
WINTER STORM WARNING UNTIL 7 PM EST /6 PM CST/ THIS EVENING FOR
INZ003>006-008.
WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR INZ007-
009.
MI...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR MIZ077>080.
WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR MIZ081.
OH...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR OHZ001-
002-004-005-015-016-024-025.
LM...GALE WARNING UNTIL 7 PM EST THIS EVENING FOR LMZ043-046.
&&
$$
SHORT TERM...T
LONG TERM...FISHER
AVIATION...T
AREA FORECAST DISCUSSION
NWS GAYLORD MI
1145 PM EST THU JAN 12 2012
.SYNOPSIS.../ISSUED AT 350 PM/
DEEP LOW PRESSURE WILL SLOWLY CREEP NORTHWARD INTO LAKE HURON
TONIGHT. SNOW WILL SPREAD OVER ALL OF NORTHERN MICHIGAN THROUGH
TONIGHT...AND THEN TAPER OFF FRIDAY. INCREASING NORTH TO NORTHEAST
WINDS...WILL TRANSPORT MUCH COLDER TEMPERATURES INTO THE REGION...
AND ALSO LEAD TO CONSIDERABLE BLOWING AND DRIFTING SNOW. A FEW LIGHT
SNOW SHOWERS AND FLURRIES...WILL LINGER INTO SATURDAY AND SUNDAY...
BUT WITH NO ADDITIONAL ACCUMULATION. TEMPERATURES WILL TURN MILDER
EARLY NEXT WEEK...AS THE NEXT ORGANIZED SYSTEM MOVES THROUGH.
HALBLAUB
&&
.SHORT TERM.../ISSUED AT 922 PM/...TONIGHT
UPDATE: GOING FCST IS WELL ON TRACK AT THIS POINT...WITH A WIDE
SWATH OF MAINLY LIGHT TO OCCASIONALLY MODERATE SNOW PINWHEELING
OVERHEAD. SAID SNOW SHIELD IS CURRENTLY BEING DRIVEN BY ELONGATED
AXIS OF WARM ADVECTION ASCENT WITHIN PRONOUNCED TROWAL FEATURE
WRAPPING NORTH OF CLOSED 850-700MB LOWS NEARING SAGINAW BAY. ALSO
HELPING IS INCREASED DEFORMATION DYNAMICS DEVELOPING OVERHEAD...
WHICH SHOULD EASILY MAINTAIN CURRENT SNOW SHIELD MUCH OF THE REST OF
THE NIGHT AS TROWAL FORCING WEAKENS. LATEST RUC FCST RAOBS COMBINED
WITH 7-8PM REPORTS (THANKS TO ALL THE SPOTTERS!) SHOW RATIOS ARE
NOTHING SPECIAL...GENERALLY AROUND 10/12 TO 1...SAVE FOR EARLIER
BETTER RATIOS ACROSS THE HIGHER TERRAIN...IN LINE WITH PROGGED
BETTER LIFT THROUGH THE DGZ...WHICH HAS SINCE FADED. SNOWFALL TOTALS
THUS FAR ARE GENERALLY 1 TO 3 INCHES ACROSS MUCH OF NORTHERN
LOWER...MAINLY LESS THAN AN INCH NORTH OF THE STRAITS...WHERE
EARLIER WEDGE OF LOW LEVEL DRY AIR HELD SNOW AT BAY UNTIL ABOUT 00Z.
HEADING THROUGH THE NIGHT...GOING HEADLINES LOOK JUST FINE...THOUGH
STARTING TO FEEL THE CURRENT WARNING MAY BE A BIT OF AN OVERKILL.
STILL...WILL GIVE IT A CHANCE WITH SOME POTENTIAL FOR LAKE
ENHANCEMENT TO KICK IN AFTER 06Z WITH INCREASING INFLUX OF MUCH
COLDER AIR (H85 TEMPS TUMBLING DOWN TOWARD -12C). IN GENERAL...HAVE
LOWERED CURRENT FCST AMOUNTS JUST A TAD IN MANY AREAS THROUGH THE
NIGHT...ESPECIALLY CLOSE TO SAGINAW BAY WHERE INCOMING DRY SLOT MAY
MAKE AN APPEARANCE. STILL LOOKING LIKE ANOTHER GENERAL 2 TO 4 INCHES
WILL FALL OVERNIGHT PER RADAR EXTRAPOLATION AND EXPECTED ONLY MODEST
RATIOS OF 15 TO 1 AT BEST...WELL IN LINE WITH CURRENT ADVISORY
(AGAIN...THE WARNING MAY BE A BIT OVERDONE) AND EARLIER
EXPECTATIONS. HAVE REWORKED DIURNAL TEMPS TO SOME DEGREE TO SHOW A
SLOWER COOLING TREND (TEMPS STILL IN THE LOWER 30S IN MANY AREAS)...
THOUGH ONCE COLD ADVECTION KICKS IN TOWARD 06Z...READINGS WILL
QUICKLY TANK THROUGH THE TEENS AND 20S IN ALL AREAS.
LAWRENCE
EARLIER EXCELLENT DISCUSSION FOLLOWS:
WINTER EVENT PLUGGING ALONG JUST FINE. LOW PRESSURE CONTINUES TO
ORGANIZE AND STRENGTHEN OVER THE THUMB OF LOWER MICHIGAN...A
FAVORABLE LOCATION FOR DECENT SNOW AMOUNTS FOR MANISTEE THROUGH
GAYLORD AND ROGERS CITY IN NRN LOWER. (AXIS OF BEST SYNOPTIC
SNOWS). THE PARENT UPPER TROUGH WHICH CLOSED OFF...IS SWEEPING
ACROSS SRN IL ATTM...WHILE +100KT UPPER JET AND LEFT EXIT DYNAMICS
AND THE DEEP LAYER -DIVQ IS AIDING THE AREAS THAT WERE ALREADY
SNOWING...WHILE ALSO ERODING THE WEDGE OF DRY AIR ACROSS NW LOWER.
SNOWS ARE STARTING TO BREAK OUT THERE. IN ADDITION SOUNDING DATA
SUPPORTING LARGE DENDRITES RIGHT NOW WITH LIFT MAXIMIZING IN THE
DGZ. FOG ERODES QUICKLY WITH ONSET OF THE SNOWS. STILL QUIET IN
EASTERN UPPER. ONLY A FEW SPOTS HAVE RAIN MIXED IN WITH THE
SNOW...PRIMARILY ON THE COASTS...AND WHERE THE SNOW REMAINS LIGHT.
EVEN NE LOWER NEAR THE BAY HAS BEEN PRIMARILY SNOW...DUE TO BETTER
PRECIPITATION INTENSITY.
THROUGH THE NIGHT...MODEST TO STRONG FORCING AND JET DYNAMICS
CONTINUE TO OVERSPREAD TROWAL THROUGH THE EVENING...YET THE LIFT
MAXIMIZED IN THE DGZ WILL FALL OFF EARLY THIS EVENING WHILE THE
LOW PRESSURE SHIFTS INTO GEORGIAN BAY. THERE IS LITTLE TO NO HELP
WITH THE LAKES THROUGH THIS TIME...SO PURELY A SYNOPTIC SNOWFALL.
THIS IS NOT A PROBLEM IN PICKING UP A SOLID 3 TO 5 INCHES THROUGH
THIS EVENING IN NRN LOWER FOR AREAS MAINLY ALONG AND WEST OF I75.
AS THE LOW PRESSURE PULLS OFF TO THE EAST...THE STRONGER DYNAMICS
EXIT AND WE TURN TO MORE OF A LAKE ENHANCED SNOWFALL WITHIN
DEFORMATION ZONE ALOFT. THE COLDEST ADVECTION WILL BE WITHIN
STRENGTHENING LOW LEVEL NORTH TO NNW FLOW ACROSS NW LOWER.
INVERSION HEIGHTS NEVER REALLY GET PAST 4500 FEET...BUT CAN SEE 2
INCHES OF LAKE HELP ADDING TO ANOTHER INCH OR SO FROM DEFORMATION
SNOWS. THUS...IN THE WARNING COUNTIES...CAN SEE UP TO 6 INCHES
FALLING THROUGH TONIGHT. THE CYCLONIC CONVERGENCE IS SO GOOD THAT
WINDS ARE MORE NNE OUT OF ONTARIO...WHICH VIRTUALLY SHUTS OFF
EASTERN UPPER FROM ANY LAKE HELP (NO FETCH). ANYWAYS...SYNOPTIC
DEFORMATION SNOWS RANGING FROM AN INCH SW TO 2 INCHES DRUMMOND
ISLAND OVERNIGHT WILL RESULT IN SNOWFALL TOTALS OF 4 TO 6 INCHES
FOR MOST OF NRN MICHIGAN THROUGH TONIGHT FOR SOLID ADVISORY
CRITERIA. DID EXPAND ADVISORIES TO INCLUDE ROSCOMMON COUNTY TO
ALPENA COUNTY. THE LEAST SNOW AMOUNTS WILL FALL IN WESTERN
CHIP/MACK OF EASTERN UPPER AWAY FROM NEST DYNAMICS AND
DEFORMATION/LAKE EFFECT...AS WELL AS COUNTIES NEAR SAG BAY...WHERE
ALSO THERE WILL BE A BIT OF DRYING ALOFT (DRY SLOT JUST SOUTHEAST
OF THERE). CAN SEE 1-3 INCHES IN THESE AREAS. WILL ALSO BE SOME
AREAS OF BLOWING SNOW DEVELOPING THROUGH THE NIGHT AS TIGHTER
PRESSURE GRADIENT SLIDES IN ON BACKSIDE OF THE DEPARTING LOW. AT
NIGHT...WORST OF THE BLOWING SNOW WILL BE ALONG THE LAKE MICHIGAN
COAST AND EVEN WHITEFISH BAY (IF THE SNOW FALLS MORE DECENTLY THAN
CURRENT THINKING FOR THERE). THE COLD ADVECTION WILL RESULT IN
LOWS FALLING INTO THE TEENS NORTH TO THE LOWER 20S SOUTH.
SMD
&&
.LONG TERM.../ISSUED AT 350 PM/...FRIDAY AND BEYOND
FRIDAY...DEFORMATION SYNOPTIC SNOWS WILL BE ENDING IN THE MORNING
AS LOW PRESSURE CONTINUES TO LIFT FURTHER EAST OF US. THE DEEPER
MOISTURE WILL BE ON THE WAY OUT AS WELL...HOWEVER THERE WILL BE A
PERIOD OF TIME WHERE THE NNW LAKE EFFECT AREAS WILL SEE MODERATE
SNOWS PERSISTING INTO THE MORNING. THUS ALL WARNINGS/ADVISORIES
WILL HOLD THROUGH THE DAY. DURING THE AFTERNOON HOWEVER...THERE
WILL BE SOME DRY AIR DIVING DOWN FROM THE NORTH. THERE IS STILL
GOOD CYCLONIC CONVERGENCE WHILE THE DRY AIR ARRIVES...AND WITH
LAKE EFFECT SUSTAINING ITSELF LONGER THAN TYPICALLY
EXPECTED...WILL KEEP SNOW SHOWERS GOING SOUTH AND WEST OF GTV BAY
THROUGH THE AFTERNOON WITH TOTAL ACCUMS OF ANOTHER 1 TO 3 INCHES.
THIS IS NOT TRUE FOR EASTERN UPPER...WHERE WINDS REMAIN OUT OF THE
NORTH. MAYBE FAR WESTERN CHIP/MACK CAN SEE SOME LIGHT SNOW
SHOWERS...BUT DOWNSLOPING FLOW FROM ONTARIO WILL LIKELY TAKE AREAS
ALONG AND EAST OF -I75 THERE...PARTLY CLOUDY (MOSTLY SUNNY?). THE
DEPARTING DEFORMATION/DEEPER MOISTURE WILL GIVE UP TO ANOTHER INCH
FOR ALL OTHER AREAS. TEMPERATURES WILL REMAIN IN THE TEENS NORTH
TO LOWER 20S SOUTH THROUGH THE DAY..AS THEY EITHER BE STEADY OR
SLOWLY FALLING IN STRONG COLD ADVECTION. WINTER IS HERE.
LATER PERIODS...
DISCUSSION...QUICK INTRUSION OF MODIFIED ARCTIC AIR LATE
THIS WEEK WILL BE JUST THAT...QUICK...WITH WELL AGREED UPON MODEL
PROGS SUGGESTING A RAPID TRANSITION TO QUASI-ZONAL FLOW REGIME BY
LATER THIS WEEKEND...TRENDING TOWARD DEEPENING WESTERN TROUGHING
EARLY NEXT WEEK. LARGE SCALE INDICES/FEATURES SUPPORT SUCH...WITH
FAR EAST DISPLACED ATLANTIC BLOCKING (MAINTENANCE OF WEAKLY
POSITIVE NAO) AND BUILDING ALEUTIAN ISLANDS/BERING SEA RIDGING
(ALLOWING ENERGY TO CUT BACK SOUTHWEST ON ITS DOWNSTREAM
SIDE...DEVELOPING THE WESTERN TROUGH). PATTERN ALSO EXPECTED TO BE
A RATHER ACTIVE ONE...BOTH WITH PRECIPITATION AND TEMPERATURE
TRENDS...AS ENERGY EJECTING OUT OF THIS WESTERN TROUGH INTERACTS
WITH TIGHTENING NORTHERN CONUS BAROCLINIC ZONE. FORECAST CONCERNS
INITIALLY CENTER ON LINGERING LIGHT LAKE INDUCED SNOW POTENTIAL IN
RETREATING COLD AIRMASS THIS WEEKEND...WITH LATER CONCERNS FOCUSED
ON THE TEMPERATURE ROLLER COASTER RIDE AND POSSIBLE EARLY WEEK
STORM SYSTEM.
SYNOPTIC EFFECTS OF CURRENT WINTER STORM WILL END QUICKLY FRIDAY
EVENING...LEAVING BEHIND MORE OF A PURE LAKE INDUCED SIGNATURE FOR
SNOW GENERATION. REMNANT SYNOPTIC MOISTURE SHOULD CONTINUE TO HELP
GENERATE LAKE INDUCED SNOWS IN FAVORED NNW FLOW AREAS EARLY FRIDAY
EVENING...WITH QUICKLY WANING INTENSITY OVERNIGHT AS MOISTURE
DEPARTS AND INVERSION LEVELS STAY AROUND 850MBS. SIMPLE OVER-WATER
INSTABILITY (DELTA T/S IN THE LOWER 20S) AND IN-CLOUD OMEGA CENTERED
IN THE DGZ FAVOR AT LEAST SOME MINOR ACCUMULATIONS THROUGH THE
OVERNIGHT...WITH PERHAPS AN INCH TO INCH AND A HALF FOCUSED JUST
WEST AND SOUTHWEST OF TRAVERSE CITY. INCREASINGLY WEAK FLOW LIKELY
TO LEAD TO SOME LAND BREEZE DISRUPTION BY SATURDAY MORNING...
FOCUSING "BEST" SNOWS TO ALONG THE LAKE MICHIGAN SHORELINE. SAME
LIGHT FLOW SUPPORTS GOOD NORTHEAST DRAINAGE FLOW OFF THE ONTARIO
PLATEAU NORTH OF THE SOO...WITH SHOULD PUSH LAKE SUPERIOR SNOWS WEST
OF WHITEFISH POINT BY EARLY SATURDAY MORNING (FRIDAY EVENING NORTH
TO NORTHEAST FLOW ALSO NOT CONDUCIVE FOR HEAVY LAKE SNOWS). HAVE
GONE AHEAD A CUT SNOW COVERAGE AND AMOUNTS SIGNIFICANTLY FRIDAY
NIGHT ACROSS EASTERN UPPER (JUST TRACE AMOUNTS). WEAK LAKE SNOWS TO
CONTINUE INTO SATURDAY...ALTHOUGH LIGHT WINDS SURE TO PLAY HAVOC
WITH EXACT PLACEMENT OF ACTIVITY. GROWING EVIDENCE OF SOME LAKE
INDUCED MESOLOW FORMATION OVER NORTHERN LAKE MICHIGAN/NORTHERN GRAND
TRAVERSE BAY LATE FRIDAY NIGHT INTO SATURDAY MORNING...WITH FOCUSED
CONVERGENCE CONTINUING THE LIGHT SNOW SHOWER THREAT ALONG THE
IMMEDIATE LAKE MICHIGAN SHORELINE. SNOW AMOUNTS SHOULD BE WELL UNDER
AN INCH...UNLESS CONVERGENCE AXIS GETS TOO OUT OF HAND (SURE HAVE
SEEN THAT BEFORE). TEMPERATURES DEPENDENT ON CLOUD COVERAGE AND SNOW
ACTIVITY...WITH PATTERN RECOGNITION OF GOOD DRAINAGE FLOW
DEVELOPMENT SUPPORTING GUIDANCE TRENDS OF DROPPING READINGS WELL
BELOW ZERO OVER EAST SECTIONS OF EASTERN UPPER...AND NEAR ZERO
READING IN THE FAVORED COLD LOCATIONS OF NORTHEAST LOWER FOR FRIDAY
NIGHT. ONE OF THE COLDEST AIR MASSES OF THE SEASON FOR SATURDAY...
WITH DAYTIME HIGHS GENERALLY STUCK IN THE TEENS.
NEBULOUS FORECAST CONTINUES THROUGH THE REMAINDER OF THE
WEEKEND...WITH GUIDANCE STRUGGLING WITH WEAK CLIPPER TYPE SYSTEM
SLATED TO CROSS THROUGH THE REGION. GFS THE MOST AGGRESSIVE BY
FAR...BRING A DECENT SURFACE LOW THROUGH THE STRAITS SUNDAY MORNING.
OTHER GUIDANCE NOT NEARLY SO AMBITIOUS...WITH JUST A DIFFUSE
RELAXATION IN THE PRESSURE FIELDS AND MUCH LESS MOISTURE. MID LEVEL
SUPPORT SIDES WITH THE LESS AGGRESSIVE SCENARIOS (AS DOES
MULTI-PERIOD TRENDS)...WHICH INHERITED FORECAST ALREADY SUPPORTS.
LAKE SNOWS MAY GET SOMEWHAT OF A BOOST TOWARDS SUNDAY MORNING...WITH
INCREASING MOISTURE PROGS AND DEVELOPING LIGHT SOUTHWEST FLOW
HELPING THE MOISTURE FLUX FROM THE WATERS. COMBINE THIS WITH
TEMPERATURES STILL PLENTY COLD ENOUGH (850MB TEMPERATURES IN THE
NEGATIVE TEENS)...AND AT LEAST SOME LIGHT SNOW SHOWERS SHOULD MOVE
INTO MACKINAC COUNTY IN FAVORED SOUTHWEST FLOW AREAS.
OTHERWISE...WILL KEEP OTHER AREAS DRY.
AS MENTIONED EARLIER...A RATHER ACTIVITY PATTERN UNFOLDING FOR NEXT
WEEK AS ENERGY DIGS OUT WEST AND BAROCLINIC ZONE TIGHTENS ACROSS THE
NORTHERN CONUS. INITIAL WARM SURGE EXPECTED TO OVERSPREAD NORTHERN
MICHIGAN QUICKLY MONDAY AS SOUTHWEST FLOW STRENGTHENS ON DOWNSTREAM
SIDE OF DEPARTING HIGH PRESSURE. SUBTLE WEAK LEAD WAVE AND MOISTURE
FLUX IN WAA REGIME MAY KICK OFF A LIGHT WINTRY MIX MONDAY (RAIN/SNOW
SOUTH...ALL SNOW NORTH). BIGGER CONCERN IS POSSIBLE LOW DEVELOPMENT
AND INTENSE FGEN SIGNATURE ALONG SLOWING COLD FRONT AS PRIMARY WAVE
EJECTS OUT OF THE PLAINS MONDAY NIGHT INTO EARLY TUESDAY. PLENTY OF
HIGH RES GUIDANCE AND LOW RES ENSEMBLE SUPPORT FOR THE
ABOVE...ALTHOUGH WITH PLENTY OF UNCERTAINTY ON THE TRACK OF THE
SURFACE LOW. WILL KEEP HIGH CHANCE SNOW WORDING MONDAY NIGHT INTO
TUESDAY TO ACCOUNT FOR REMAINING UNCERTAINTY. WILL SAY SOME OF THE
GFS ENSEMBLES ARE AWFULLY STRONG WITH THIS SYSTEM (SUB 990MBS)...AND
WITH THE TENDENCY FOR THESE PACIFIC WAVES TO END UP STRONGER THAN
INITIALLY PROGGED DOES LEND AT LEAST SOME CREDENCE TO THESE STRONGER
SOLUTIONS. DEFINITELY SOMETHING TO WATCH WITH MOUNTING EVIDENCE OF A
GREAT WESTERN GULF OF MEXICO MOISTURE CONNECTION. WILL CONTINUE TO
HIGHLIGHT THIS POTENTIAL IN THE AFTERNOON RENDITION OF THE HAZARDOUS
WEATHER OUTLOOK. A GLANCING BLOW OF VERY COLD ARCTIC AIR TO FOLLOW
THIS SYSTEM TUESDAY NIGHT INTO THURSDAY...WITH 850MB TEMPERATURES
FALLING TO NEAR -20C. MORE THAN COLD ENOUGH TO START THE LAKE
MACHINE...ESPECIALLY IN FAVORED NORTHWEST FLOW AREAS. HIGH
TEMPERATURES BACK IN THE TEENS BOTH WEDNESDAY AND THURSDAY.
MSB
&&
.MARINE.../ISSUED AT 350 PM/
WINDS WILL BE INCREASING THROUGH TONIGHT FROM WEST TO EAST ACROSS
THE GREAT LAKES AS TIGHTER PRESSURE GRADIENT SLIDES IN BEHIND A
DEPARTING LOW PRESSURE SYSTEM THAT WILL BE PRODUCING MODERATE TO
HEAVY SNOWS ACROSS THE REGION. GALES STILL LOOK REAL GOOD FOR
SLEEPING BEAR POINT SOUTHWARD...BUT REMAIN JUST SHY ALL OTHER
AREAS INTO TOMORROW. THUS...ALL HEADLINES WILL HOLD AS IS. WAVE
ACTION WILL CONTINUE TO BE AN ISSUE INTO FRIDAY NIGHT.
SMD
NORTHWEST WINDS EXPECTED TO SUBSIDE RATHER QUICKLY FRIDAY
EVENING AS HIGH PRESSURE BUILDS INTO THE AREA. LIGHT WINDS WILL
CONTINUE THROUGH AT LEAST SATURDAY NIGHT...WITH SOUTHWEST FLOW
BEGINNING TO STRENGTHEN BY LATER SUNDAY. SOUTH WINDS...AT TIMES
GUSTY...WILL CONTINUE INTO EARLY NEXT WORK WEEK AHEAD OF AN
APPROACHING COLD FRONT.
MSB
&&
.AVIATION.../ISSUED AT 1145 PM/...VALID FOR 06Z TAFS
WIDESPREAD LIGHT TO OCCASIONALLY MODERATE SNOW WITH IFR
CONDITIONS WILL CONTINUE AT ALL TERMINAL SITES THE REMAINDER OF
THE NIGHT...ENDING FROM WEST TO EAST THROUGH THE MORNING AS UPPER
LEVEL FORCING WANES AND MOISTURE DECREASES. EXPECT SOME
DEVELOPMENT OF LAKE EFFECT SNOW SHOWERS AS WINDS SETTLE IN FROM
THE NORTH/NORTHWEST...FAVORING PRIMARILY TVC AND MBL FOR THE
LOWEST CEILINGS AND BRIEF INTERLUDES OF LOWER VISBYS. WINDS WILL
BECOME GUSTY FOR ALL LOCATIONS THROUGH THE NIGHT...WITH THE
POTENTIAL FOR SOME LOCALIZED BLOWING AND DRIFTING SNOW. DRIER AIR
WILL ENTER THE PICTURE TONIGHT...WITH PLN POSSIBLY CLEARING AND
VFR CONDITIONS MAKING A RETURN TO APN WHILE TVC/MBL MAINTAIN
PERIODIC LAKE EFFECT SNOW SHOWERS.
LAWRENCE
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY UNTIL 7 PM EST FRIDAY FOR MIZ008-015>019-
022>024-027>029-033-034.
WINTER STORM WARNING UNTIL 7 PM EST FRIDAY FOR MIZ020-021-025-
026-031-032.
LH...SMALL CRAFT ADVISORY UNTIL 11 PM EST FRIDAY FOR LHZ345>349.
LM...SMALL CRAFT ADVISORY UNTIL 11 PM EST FRIDAY FOR LMZ323-341-342.
GALE WARNING UNTIL 5 PM EST FRIDAY FOR LMZ344>346.
LS...SMALL CRAFT ADVISORY UNTIL 11 PM EST FRIDAY FOR LSZ321-322.
&&
$$
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1145 PM CST THU JAN 12 2012
.UPDATE...FOR 06Z AVIATION DISCUSSION.
&&
.AVIATION...06Z AVIATION DISCUSSION.
UNCERTAINTIES...CEILING TRANSITION TIMINGS...SNOW SHWRS IMPACTS AND
TAPERING OFF TIMING...SFC WIND GUST POTENTIAL. SEVERAL ADMS POSSIBLE
THRU 14/06Z. BROAD UPPER LEVEL TROUGHING WILL CONTINUE TO MOVE NEWD
OF THE MID STATE BY 13/12Z...WITH MAIN IMPACTS OF SNOW SHWRS 13/06Z
-13/11Z....WITH MVFR CEILING FLUCTUATIONS. GUSTY SFC WINDS OF UP TO
25 KTS EXPECTED THRU 14/00Z PER STRONG SFC PRESSURE GRADIENT INFLUENCES.
CLING SKIES EXPECTED W TO E BETWEEN 13/16Z-13/18Z WITH SFC/UPPER LEVEL
RIDGING INFLUENCES PROVIDING ONLY POSSIBLE BKN CI THRU 14/06Z.
&&
.PREV DISCUSSION.../ISSUED 1115 PM CST THU JAN 12 2012/
UPDATE...
UPDATED WSW CODE AT BOTTOM. ZONES OUT SHORTLY.
PREV DISCUSSION.../ISSUED 1038 PM CST THU JAN 12 2012/
UPDATE...
MOSTLY LIGHT TO OCCASIONALLY MODERATE SNOW SHOWERS CONTINUE TO FALL
ACROSS PRIMARILY THE NORTHERN HALF OF THE MID STATE. UPON
EXAMINATION OF THE PAH RADAR...IT DOES LOOK AS THOUGH A DECREASE
IN COVERAGE AND INTENSITY IS INDICATED.
THE FORECAST LOOKS LIKE IT REMAINS ON TRACK. HOWEVER...WE WILL BE
EXTENDING THE WINTER WEATHER ADVISORY FOR THE CENTRAL AND NORTHERN
CUMBERLAND PLATEAU. SNOWFALL WILL LIKELY CONTINUE WELL PAST
MIDNIGHT ACROSS THAT AREA. THE WINTER WEATHER ADVISORY WILL EXPIRE
FOR THE PLATEAU AT 8 AM FRIDAY MORNING. ADDITIONAL ACCUMULATIONS
OF AROUND 1 INCH CAN BE EXPECTED.
OTW...WILL INCLUDE LOWER CHANCES OF MEASURABLE SNOW WEST OF THE
PLATEAU FOR THE AFTER MIDNIGHT PERIOD. FOR AREAS ADJACENT TO THE
PLATEAU...WILL KEEP 30-50 POPS RUNNING WITH 20 POPS FAR WEST.
MINIMAL ADDITIONAL ACCUMULATIONS ARE EXPECTED WEST OF THE PLATEAU
AFTER MIDNIGHT.
THIS AFD WILL BE REISSUED AROUND 11PM...ONCE THE NEW WSW IS
SENT...TO REFLECT THE PROPER WSW ZONE CODING AT THE BOTTOM OF THIS
MESSAGE.
PREV DISCUSSION... /ISSUED 826 PM CST THU JAN 12 2012/
UPDATED DISCUSSION...
SNOWFALL REPORTS CONTINUE TO TRICKLE IN THIS EVENING.
GENERALLY...ONE HALF TO ONE INCH AMOUNTS ACROSS THE FAR NORTHERN
TIER OF THE MID STATE. AREAS ALONG THE PLATEAU ARE ALSO SPORTING
ONE HALF TO 1 INCH AMOUNTS. RECENT RADAR TRENDS DID SHOW SOME
ENHANCEMENT MOVE ACROSS STEWART COUNTY AND WE DID GET A LOCAL
REPORT OF 1 TO 2 INCHES FOLLOWING THE BRIEF PERIOD OF HEAVIER
SNOWFALL.
OTW...LATEST RUC DATA STILL SHOWS THE SNOWFALL CUTTING OFF AROUND
06S TO THE WEST OF THE PLATEAU. LOOKING UPSTREAM...VSBYS ARE ALL
P6SM SO THIS IS LOOKING BELIEVABLE. FURTHERMORE...ECHO TRENDS
APPEARS TO BE WEAKENING TO OUR NORTHWEST.
RECEIVED A REPORT OF A 1 HOUR CLOSURE OF I-65 THROUGH MARSHALL
COUNTY DUE TO THE ROAD CONDITIONS. THUS...I HAVE UPDATED THE SPS TO
COVER ALL OF MIDDLE TN THROUGH THE OVERNIGHT. THE SPS WAS ISSUED
TO ADVISE OF THE DANGEROUS ROAD CONDITIONS DUE TO THE WINTRY PRECIP.
NO CHANGES TO THE ZONE FORECAST FOR NOW. I WILL UP THE SNOWFALL
GRIDS JUST BY ONE OR TWO TENTHS ACROSS THE STEWART COUNTY AREA.
OTW...EVERYTHING LOOKS OK FOR NOW.
PREV DISCUSSION... /ISSUED 553 PM CST THU JAN 12 2012/
DISCUSSION...
AREAS OF SNOWFALL CONTINUE AT THIS HOUR ACROSS MUCH OF THE
NORTHERN HALF OF MIDDLE TN. SCATTERED SNOW SHOWERS ARE ALSO NOTED
ACROSS SOUTHERN AREAS. SNOWFALL REPORTS ARE SCATTERED AND ARE
GENERALLY UNDER 1 INCH SO FAR.
FIRST ORDER OF BUSINESS WILL BE TO ALLOW THE WIND ADVISORY TO
EXPIRE AT 6PM CST. LATEST WIND REPORTS THROUGHOUT THE CWA ARE AT
THE SUB ADVISORY LEVEL. THUS...WITH THE WEAKENING GRADIENT TREND
EXPECTED TO CONTINUE...WILL ALLOW THE WIND ADVISORY TO EXPIRE.
SECOND ORDER OF BUSINESS WILL INVOLVE THE DECREASE IN ZONE
GROUPINGS ACROSS THE CWA. WILL DO THIS SO AS TO ALLOW THE ZONE
TEXT SNOWFALL AMOUNTS TO MATCH THE GRAPHICS AND WSW THAT IS
CURRENTLY IN EFFECT.
AS OF NOW EXPECTED SNOWFALL TOTALS...SNOWFALL GRAPHIC AND THE CURRENT
WSW APPEARS TO BE ON TRACK. WILL ADJUST ZONES TO MATCH.
OTW...MUCH LESS SNOWFALL COVERAGE IS NOTED ON THE MEG RADAR. THIS
WILL LIKELY CALL FOR PRE MIDNIGHT WORDING IN TERMS OF OUR SNOWFALL
POTENTIAL. THE 6HR QPF RETURNS FROM THE MODELS LOOK TO CUT OFF
THE SNOWFALL TO THE WEST OF THE CUMBERLAND PLATEAU. THIS WILL NEED
TO BE REFLECTED IN THE UPCOMING UPDATE.
I WILL ALSO POINT OUT THAT AN SPS HAS BEEN ISSUED TO TO ADVISE THE
MID STATE AREA OF THE DANGEROUS ROAD CONDITIONS THAT ARE IN PLACE.
THOUGH THE ACCUMULATION POTENTIAL WILL LESSEN WITH TIME
OVERNIGHT...THE ROAD CONDITIONS MAY IN FACT WORSEN.
THAT`S ALL FOR NOW...I`LL FIRST UPDATE THE GRIDS AND THEN RUN THE
FORMATTERS. ZONES WILL THEN FOLLOW SHORTLY.
PREV DISCUSSION... /ISSUED 259 PM CST THU JAN 12 2012/
DISCUSSION...SURFACE MAP AT 21Z SHOWS COLD FRONT COMPLETELY
THROUGH MIDDLE TENNESSEE, WITH RAPID COLD ADVECTION TAKING PLACE
ACROSS THE MID STATE. HAVE ALREADY RECEIVED SEVERAL REPORTS OF
LIGHT SNOW AND ICE, MAINLY ON THE NORTH SIDE OF I-40. DEEPEST
MOISTURE HAS ALREADY PULLED EAST OF THE MID STATE, WITH REMAINING
MOISTURE CONFINED TO THE LOWEST 10 KFT. LATEST MODELS SHOW LOW-
LEVEL WRAP-AROUND MOISTURE CONTINUING TO CIRCULATE THROUGH THE MID
STATE OVERNIGHT AND EARLY TOMORROW MORNING. QPF`S ARE RELATIVELY
LOW, WITH THE HIGHEST AMOUNTS OCCURRING ALONG THE UPPER PLATEAU,
TAPERING OFF TO NEAR ZERO IN OUR SOUTHWEST. SNOW AMOUNTS UP TO AN
INCH ARE POSSIBLE ALONG THE HIGHLAND RIM AND AREAS JUST WEST OF
THE CUMBERLAND PLATEAU, WITH 1 TO 2 INCHES POSSIBLE ALONG THE
PLATEAU ITSELF. SNOW WILL TAPER OFF SIGNIFICANTLY AFTER MIDNIGHT,
SO WILL CONTINUE THE WSW UNTIL 06Z TONIGHT. TEMPERATURES WILL
CONTINUE THEIR FREE-FALL OVERNIGHT, DROPPING BELOW 20 DEGREES IN
MANY PLACES. THUS, WHATEVER PRECIPITATION DOES FALL LATE THIS
AFTERNOON AND OVERNIGHT WILL LIKELY FREEZE AND STAY FROZEN UNTIL
TOMORROW.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR
TNZ005>009-028>030-063-064-077>080.
WINTER WEATHER ADVISORY UNTIL 9 AM CST FRIDAY FOR TNZ010-011-
031>034-065-066.
&&
$$
31
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1115 PM CST THU JAN 12 2012
.UPDATE...
UPDATED WSW CODE AT BOTTOM. ZONES OUT SHORTLY.
&&
.PREV DISCUSSION... /ISSUED 1038 PM CST THU JAN 12 2012/
UPDATE...
MOSTLY LIGHT TO OCCASIONALLY MODERATE SNOW SHOWERS CONTINUE TO FALL
ACROSS PRIMARILY THE NORTHERN HALF OF THE MID STATE. UPON
EXAMINATION OF THE PAH RADAR...IT DOES LOOK AS THOUGH A DECREASE
IN COVERAGE AND INTENSITY IS INDICATED.
THE FORECAST LOOKS LIKE IT REMAINS ON TRACK. HOWEVER...WE WILL BE
EXTENDING THE WINTER WEATHER ADVISORY FOR THE CENTRAL AND NORTHERN
CUMBERLAND PLATEAU. SNOWFALL WILL LIKELY CONTINUE WELL PAST
MIDNIGHT ACROSS THAT AREA. THE WINTER WEATHER ADVISORY WILL EXPIRE
FOR THE PLATEAU AT 8 AM FRIDAY MORNING. ADDITIONAL ACCUMULATIONS
OF AROUND 1 INCH CAN BE EXPECTED.
OTW...WILL INCLUDE LOWER CHANCES OF MEASURABLE SNOW WEST OF THE
PLATEAU FOR THE AFTER MIDNIGHT PERIOD. FOR AREAS ADJACENT TO THE
PLATEAU...WILL KEEP 30-50 POPS RUNNING WITH 20 POPS FAR WEST.
MINIMAL ADDITIONAL ACCUMULATIONS ARE EXPECTED WEST OF THE PLATEAU
AFTER MIDNIGHT.
THIS AFD WILL BE REISSUED AROUND 11PM...ONCE THE NEW WSW IS
SENT...TO REFLECT THE PROPER WSW ZONE CODING AT THE BOTTOM OF THIS
MESSAGE.
PREV DISCUSSION... /ISSUED 826 PM CST THU JAN 12 2012/
UPDATED DISCUSSION...
SNOWFALL REPORTS CONTINUE TO TRICKLE IN THIS EVENING.
GENERALLY...ONE HALF TO ONE INCH AMOUNTS ACROSS THE FAR NORTHERN
TIER OF THE MID STATE. AREAS ALONG THE PLATEAU ARE ALSO SPORTING
ONE HALF TO 1 INCH AMOUNTS. RECENT RADAR TRENDS DID SHOW SOME
ENHANCEMENT MOVE ACROSS STEWART COUNTY AND WE DID GET A LOCAL
REPORT OF 1 TO 2 INCHES FOLLOWING THE BRIEF PERIOD OF HEAVIER
SNOWFALL.
OTW...LATEST RUC DATA STILL SHOWS THE SNOWFALL CUTTING OFF AROUND
06S TO THE WEST OF THE PLATEAU. LOOKING UPSTREAM...VSBYS ARE ALL
P6SM SO THIS IS LOOKING BELIEVABLE. FURTHERMORE...ECHO TRENDS
APPEARS TO BE WEAKENING TO OUR NORTHWEST.
RECEIVED A REPORT OF A 1 HOUR CLOSURE OF I-65 THROUGH MARSHALL
COUNTY DUE TO THE ROAD CONDITIONS. THUS...I HAVE UPDATED THE SPS TO
COVER ALL OF MIDDLE TN THROUGH THE OVERNIGHT. THE SPS WAS ISSUED
TO ADVISE OF THE DANGEROUS ROAD CONDITIONS DUE TO THE WINTRY PRECIP.
NO CHANGES TO THE ZONE FORECAST FOR NOW. I WILL UP THE SNOWFALL
GRIDS JUST BY ONE OR TWO TENTHS ACROSS THE STEWART COUNTY AREA.
OTW...EVERYTHING LOOKS OK FOR NOW.
PREV DISCUSSION... /ISSUED 553 PM CST THU JAN 12 2012/
DISCUSSION...
AREAS OF SNOWFALL CONTINUE AT THIS HOUR ACROSS MUCH OF THE
NORTHERN HALF OF MIDDLE TN. SCATTERED SNOW SHOWERS ARE ALSO NOTED
ACROSS SOUTHERN AREAS. SNOWFALL REPORTS ARE SCATTERED AND ARE
GENERALLY UNDER 1 INCH SO FAR.
FIRST ORDER OF BUSINESS WILL BE TO ALLOW THE WIND ADVISORY TO
EXPIRE AT 6PM CST. LATEST WIND REPORTS THROUGHOUT THE CWA ARE AT
THE SUB ADVISORY LEVEL. THUS...WITH THE WEAKENING GRADIENT TREND
EXPECTED TO CONTINUE...WILL ALLOW THE WIND ADVISORY TO EXPIRE.
SECOND ORDER OF BUSINESS WILL INVOLVE THE DECREASE IN ZONE
GROUPINGS ACROSS THE CWA. WILL DO THIS SO AS TO ALLOW THE ZONE
TEXT SNOWFALL AMOUNTS TO MATCH THE GRAPHICS AND WSW THAT IS
CURRENTLY IN EFFECT.
AS OF NOW EXPECTED SNOWFALL TOTALS...SNOWFALL GRAPHIC AND THE CURRENT
WSW APPEARS TO BE ON TRACK. WILL ADJUST ZONES TO MATCH.
OTW...MUCH LESS SNOWFALL COVERAGE IS NOTED ON THE MEG RADAR. THIS
WILL LIKELY CALL FOR PRE MIDNIGHT WORDING IN TERMS OF OUR SNOWFALL
POTENTIAL. THE 6HR QPF RETURNS FROM THE MODELS LOOK TO CUT OFF
THE SNOWFALL TO THE WEST OF THE CUMBERLAND PLATEAU. THIS WILL NEED
TO BE REFLECTED IN THE UPCOMING UPDATE.
I WILL ALSO POINT OUT THAT AN SPS HAS BEEN ISSUED TO TO ADVISE THE
MID STATE AREA OF THE DANGEROUS ROAD CONDITIONS THAT ARE IN PLACE.
THOUGH THE ACCUMULATION POTENTIAL WILL LESSEN WITH TIME
OVERNIGHT...THE ROAD CONDITIONS MAY IN FACT WORSEN.
THAT`S ALL FOR NOW...I`LL FIRST UPDATE THE GRIDS AND THEN RUN THE
FORMATTERS. ZONES WILL THEN FOLLOW SHORTLY.
PREV DISCUSSION... /ISSUED 259 PM CST THU JAN 12 2012/
DISCUSSION...SURFACE MAP AT 21Z SHOWS COLD FRONT COMPLETELY
THROUGH MIDDLE TENNESSEE, WITH RAPID COLD ADVECTION TAKING PLACE
ACROSS THE MID STATE. HAVE ALREADY RECEIVED SEVERAL REPORTS OF
LIGHT SNOW AND ICE, MAINLY ON THE NORTH SIDE OF I-40. DEEPEST
MOISTURE HAS ALREADY PULLED EAST OF THE MID STATE, WITH REMAINING
MOISTURE CONFINED TO THE LOWEST 10 KFT. LATEST MODELS SHOW LOW-
LEVEL WRAP-AROUND MOISTURE CONTINUING TO CIRCULATE THROUGH THE MID
STATE OVERNIGHT AND EARLY TOMORROW MORNING. QPF`S ARE RELATIVELY
LOW, WITH THE HIGHEST AMOUNTS OCCURRING ALONG THE UPPER PLATEAU,
TAPERING OFF TO NEAR ZERO IN OUR SOUTHWEST. SNOW AMOUNTS UP TO AN
INCH ARE POSSIBLE ALONG THE HIGHLAND RIM AND AREAS JUST WEST OF
THE CUMBERLAND PLATEAU, WITH 1 TO 2 INCHES POSSIBLE ALONG THE
PLATEAU ITSELF. SNOW WILL TAPER OFF SIGNIFICANTLY AFTER MIDNIGHT,
SO WILL CONTINUE THE WSW UNTIL 06Z TONIGHT. TEMPERATURES WILL
CONTINUE THEIR FREE-FALL OVERNIGHT, DROPPING BELOW 20 DEGREES IN
MANY PLACES. THUS, WHATEVER PRECIPITATION DOES FALL LATE THIS
AFTERNOON AND OVERNIGHT WILL LIKELY FREEZE AND STAY FROZEN UNTIL
TOMORROW.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR
TNZ005>009-028>030-063-064-077>080.
WINTER WEATHER ADVISORY UNTIL 9 AM CST FRIDAY FOR TNZ010-011-
031>034-065-066.
&&
$$
21
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1038 PM CST THU JAN 12 2012
.UPDATE...
MOSTLY LIGHT TO OCCASIONALLY MODERATE SNOW SHOWERS CONTINUE TO FALL
ACROSS PRIMARILY THE NORTHERN HALF OF THE MID STATE. UPON
EXAMINATION OF THE PAH RADAR...IT DOES LOOK AS THOUGH A DECREASE
IN COVERAGE AND INTENSITY IS INDICATED.
THE FORECAST LOOKS LIKE IT REMAINS ON TRACK. HOWEVER...WE WILL BE
EXTENDING THE WINTER WEATHER ADVISORY FOR THE CENTRAL AND NORTHERN
CUMBERLAND PLATEAU. SNOWFALL WILL LIKELY CONTINUE WELL PAST
MIDNIGHT ACROSS THAT AREA. THE WINTER WEATHER ADVISORY WILL EXPIRE
FOR THE PLATEAU AT 8 AM FRIDAY MORNING. ADDITIONAL ACCUMULATIONS
OF AROUND 1 INCH CAN BE EXPECTED.
OTW...WILL INCLUDE LOWER CHANCES OF MEASURABLE SNOW WEST OF THE
PLATEAU FOR THE AFTER MIDNIGHT PERIOD. FOR AREAS ADJACENT TO THE
PLATEAU...WILL KEEP 30-50 POPS RUNNING WITH 20 POPS FAR WEST.
MINIMAL ADDITIONAL ACCUMULATIONS ARE EXPECTED WEST OF THE PLATEAU
AFTER MIDNIGHT.
THIS AFD WILL BE REISSUED AROUND 11PM...ONCE THE NEW WSW IS
SENT...TO REFLECT THE PROPER WSW ZONE CODING AT THE BOTTOM OF THIS
MESSAGE.
&&
.PREV DISCUSSION... /ISSUED 826 PM CST THU JAN 12 2012/
UPDATED DISCUSSION...
SNOWFALL REPORTS CONTINUE TO TRICKLE IN THIS EVENING.
GENERALLY...ONE HALF TO ONE INCH AMOUNTS ACROSS THE FAR NORTHERN
TIER OF THE MID STATE. AREAS ALONG THE PLATEAU ARE ALSO SPORTING
ONE HALF TO 1 INCH AMOUNTS. RECENT RADAR TRENDS DID SHOW SOME
ENHANCEMENT MOVE ACROSS STEWART COUNTY AND WE DID GET A LOCAL
REPORT OF 1 TO 2 INCHES FOLLOWING THE BRIEF PERIOD OF HEAVIER
SNOWFALL.
OTW...LATEST RUC DATA STILL SHOWS THE SNOWFALL CUTTING OFF AROUND
06S TO THE WEST OF THE PLATEAU. LOOKING UPSTREAM...VSBYS ARE ALL
P6SM SO THIS IS LOOKING BELIEVABLE. FURTHERMORE...ECHO TRENDS
APPEARS TO BE WEAKENING TO OUR NORTHWEST.
RECEIVED A REPORT OF A 1 HOUR CLOSURE OF I-65 THROUGH MARSHALL
COUNTY DUE TO THE ROAD CONDITIONS. THUS...I HAVE UPDATED THE SPS TO
COVER ALL OF MIDDLE TN THROUGH THE OVERNIGHT. THE SPS WAS ISSUED
TO ADVISE OF THE DANGEROUS ROAD CONDITIONS DUE TO THE WINTRY PRECIP.
NO CHANGES TO THE ZONE FORECAST FOR NOW. I WILL UP THE SNOWFALL
GRIDS JUST BY ONE OR TWO TENTHS ACROSS THE STEWART COUNTY AREA.
OTW...EVERYTHING LOOKS OK FOR NOW.
PREV DISCUSSION... /ISSUED 553 PM CST THU JAN 12 2012/
DISCUSSION...
AREAS OF SNOWFALL CONTINUE AT THIS HOUR ACROSS MUCH OF THE
NORTHERN HALF OF MIDDLE TN. SCATTERED SNOW SHOWERS ARE ALSO NOTED
ACROSS SOUTHERN AREAS. SNOWFALL REPORTS ARE SCATTERED AND ARE
GENERALLY UNDER 1 INCH SO FAR.
FIRST ORDER OF BUSINESS WILL BE TO ALLOW THE WIND ADVISORY TO
EXPIRE AT 6PM CST. LATEST WIND REPORTS THROUGHOUT THE CWA ARE AT
THE SUB ADVISORY LEVEL. THUS...WITH THE WEAKENING GRADIENT TREND
EXPECTED TO CONTINUE...WILL ALLOW THE WIND ADVISORY TO EXPIRE.
SECOND ORDER OF BUSINESS WILL INVOLVE THE DECREASE IN ZONE
GROUPINGS ACROSS THE CWA. WILL DO THIS SO AS TO ALLOW THE ZONE
TEXT SNOWFALL AMOUNTS TO MATCH THE GRAPHICS AND WSW THAT IS
CURRENTLY IN EFFECT.
AS OF NOW EXPECTED SNOWFALL TOTALS...SNOWFALL GRAPHIC AND THE CURRENT
WSW APPEARS TO BE ON TRACK. WILL ADJUST ZONES TO MATCH.
OTW...MUCH LESS SNOWFALL COVERAGE IS NOTED ON THE MEG RADAR. THIS
WILL LIKELY CALL FOR PRE MIDNIGHT WORDING IN TERMS OF OUR SNOWFALL
POTENTIAL. THE 6HR QPF RETURNS FROM THE MODELS LOOK TO CUT OFF
THE SNOWFALL TO THE WEST OF THE CUMBERLAND PLATEAU. THIS WILL NEED
TO BE REFLECTED IN THE UPCOMING UPDATE.
I WILL ALSO POINT OUT THAT AN SPS HAS BEEN ISSUED TO TO ADVISE THE
MID STATE AREA OF THE DANGEROUS ROAD CONDITIONS THAT ARE IN PLACE.
THOUGH THE ACCUMULATION POTENTIAL WILL LESSEN WITH TIME
OVERNIGHT...THE ROAD CONDITIONS MAY IN FACT WORSEN.
THAT`S ALL FOR NOW...I`LL FIRST UPDATE THE GRIDS AND THEN RUN THE
FORMATTERS. ZONES WILL THEN FOLLOW SHORTLY.
PREV DISCUSSION... /ISSUED 259 PM CST THU JAN 12 2012/
DISCUSSION...SURFACE MAP AT 21Z SHOWS COLD FRONT COMPLETELY
THROUGH MIDDLE TENNESSEE, WITH RAPID COLD ADVECTION TAKING PLACE
ACROSS THE MID STATE. HAVE ALREADY RECEIVED SEVERAL REPORTS OF
LIGHT SNOW AND ICE, MAINLY ON THE NORTH SIDE OF I-40. DEEPEST
MOISTURE HAS ALREADY PULLED EAST OF THE MID STATE, WITH REMAINING
MOISTURE CONFINED TO THE LOWEST 10 KFT. LATEST MODELS SHOW LOW-
LEVEL WRAP-AROUND MOISTURE CONTINUING TO CIRCULATE THROUGH THE MID
STATE OVERNIGHT AND EARLY TOMORROW MORNING. QPF`S ARE RELATIVELY
LOW, WITH THE HIGHEST AMOUNTS OCCURRING ALONG THE UPPER PLATEAU,
TAPERING OFF TO NEAR ZERO IN OUR SOUTHWEST. SNOW AMOUNTS UP TO AN
INCH ARE POSSIBLE ALONG THE HIGHLAND RIM AND AREAS JUST WEST OF
THE CUMBERLAND PLATEAU, WITH 1 TO 2 INCHES POSSIBLE ALONG THE
PLATEAU ITSELF. SNOW WILL TAPER OFF SIGNIFICANTLY AFTER MIDNIGHT,
SO WILL CONTINUE THE WSW UNTIL 06Z TONIGHT. TEMPERATURES WILL
CONTINUE THEIR FREE-FALL OVERNIGHT, DROPPING BELOW 20 DEGREES IN
MANY PLACES. THUS, WHATEVER PRECIPITATION DOES FALL LATE THIS
AFTERNOON AND OVERNIGHT WILL LIKELY FREEZE AND STAY FROZEN UNTIL
TOMORROW.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR
TNZ005>011-028>034-063>066-077>080.
&&
$$
21
AREA FORECAST DISCUSSION
NWS DENVER CO
321 AM MST FRI JAN 13 2012
.SHORT TERM...NW FLOW ALOFT WILL REMAIN OVER THE AREA THRU TONIGHT.
QUITE A BIT OF HIGHER LEVEL MOISTURE WILL MOVE ACROSS THE AREA TODAY
WITH PERIODS OF HIGHER LEVEL CLOUDS THRU THIS AFTN BUT NO PCPN.
CROSS-SECTIONS SHOW GUSTY NWLY WINDS WILL OCCUR IN THE
MTNS...FOOTHILLS AND ACROSS THE NERN PLAINS ESPECIALLY NR THE WY-NE
BORDER AREA. GUSTS MAY REACH THE 40-45 MPH RANGE THIS AFTN NR THE
WY-NE BORDER WITH 55-60 MPH IN THE FOOTHILLS AND HIGHER MTNS. AT
THIS TIME WINDS SHOULD STAY BLO WARNING CRITERIA. OTHER CONCERN
WOULD BE FIRE WEATHER POTENTIAL OVER PARTS OF THE NERN PLAINS
HOWEVER MODELS ARE SHOWING VARYING HUMIDITY LEVELS THIS AFTN SO NOT
SURE WHICH SOLUTIONS ARE RIGHT. THERE MAY BE A SMALL 3 HOUR WINDOW
FROM 20Z-23Z WHERE CONDITIONS MAY BE MET MAINLY ALONG THE WY-NE
BORDER. AS FAR AS TEMPS SHOULD CONTINUE TO SEE WARMER READINGS WITH
HIGHS IN THE 45 TO 50 DEGREE RANGE ACROSS NERN CO.
FOR TONIGHT NW FLOW WILL CONTINUE HOWEVER HIGHER LEVEL MOISTURE WILL
DECREASE SO HIGH LEVEL CLOUDINESS SHOULD DIMINISH. CROSS-SECTIONS
CONTINUE TO SHOW GUSTY WINDS OVER THE HIGHER MTNS AND FOOTHILLS
OVERNIGHT BUT SPEEDS SHOULD REMAIN BLO WARNING CRITERIA.
.LONG TERM....UPPER RIDGING DOMINATES THE FORECAST AREA INTO MID DAY
SUNDAY...WITH NORTHWESTERLY FLOW ALOFT SATURDAY...BECOMING ZONAL
SATURDAY NIGHT INTO SUNDAY. BY LATER SUNDAY AFTERNOON AND NIGHT
...THE FLOW ALOFT BECOMES SOUTHWESTERLY WITH AN UPPER TROUGH MOVING
INTO THE GREAT BASIN FROM THE NORTHWEST. THE SYNOPTIC SCALE ENERGY
IS BENIGN SATURDAY INTO SUNDAY AFTERNOON...THEN WEAK QG ASCENT MOVES
IN LATE. BY MONDAY MORNING...THE UPWARD VERTICAL VELOCITY IS
PROGGED TO INCREASE. THE BOUNDARY LAYER FLOW WILL LIKELY BE
DOWNSLOPING IN NATURE SATURDAY THROUGH SUNDAY...WITH LOW LEVEL
TROUGHING EAST OF THE MOUNTAINS ALL WEEKEND. FOR MOISTURE...THERE
IS SOME IN THE MID AND UPPER LEVELS SATURDAY THROUGH SUNDAY...MORE
SO ON THE GFS. AFTER 06Z SUNDAY NIGHT...BOTH MODELS INCREASE
MOISTURE DRAMATICALLY OVER THE MOUNTAINS. THE QPF FIELDS SHOW NO
MEASURABLE PRECIPITATION OVER THE CWA SATURDAY THROUGH MIDNIGHT
SUNDAY NIGHT. THERE IS A TAD OVER THE MOUNTAINS WEST OF THE DIVIDE
PROGGED FROM 06Z TO 12Z MONDAY MORNING. NO POPS THROUGH SUNDAY
EVENING...THEN 20%S IN THE HIGH MOUNTAINS OVERNIGHT SUNDAY. FOR
TEMPERATURES...SATURDAY`S HIGHS ARE 3-4.5 C WARMER THAN TODAY`S.
SUNDAY`S HIGHS ARE 1-3 C WARMER THAN SATURDAY`S. FOR THE LATER
DAYS...MONDAY THROUGH THURSDAY...THE NAM...GFS...AND ECMWF ALL SHOW
AN UPPER TROUGH TO MOVE ACROSS THE CWA LATER MONDAY AND MONDAY
NIGHT. THERE IS MOISTURE...COLD AIR...AND UPSLOPE FOR THE PLAINS
AND FOOTHILLS. HOWEVER IT IS A QUICK SHOT. AFTER THE TROUGH AXIS
MOVES THROUGH...PRETTY STRONG NORTHWESTERLY FLOW ALOFT IS PROGGED TO
CONTINUE MUCH OF NEXT WEEK. THE GFS SHOWS FAIRLY DECENT MOISTURE IN
THE FLOW...BUT THE ECMWF HAS LESS. THIS TYPE OF PATTERN WOULD FAVOR
MOUNTAIN SNOWS OFF AND ON. WE`LL SEE. MONDAY AND TUESDAY LOOK
PRETTY COLD...WITH WARMING FOR WEDNESDAY AND THURSDAY.
&&
.AVIATION...OUTSIDE OF SOME HIGHER LEVEL CLOUDS VFR CONDITIONS WILL
BE IN PLACE THRU TONIGHT. WINDS THIS MORNING WILL BE SSW BUT WILL
SHIFT TO MORE WLY BY 17Z. IN THE AFTN BOTH THE RUC AND HRRR SO
A SURGE OF STRONGER WINDS COMING OFF THE FOOTHILLS FM THE WNW AROUND
20Z WITH GUSTS OF 25-30 MPH POSSIBLE FM 20Z-23Z. BY EARLY EVENING
WINDS SHOULD GRADUALLY BECOME MORE WSW WITH DECREASING SPEEDS AND
THEN WILL BECOME MORE SSW BY 06Z.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
RPK/RJK
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
635 AM EST FRI Jan 13 2012
...Updated for 12Z Aviation Update...
.SYNOPSIS...
08Z water vapor and H4 RUC analysis shows an amplified upper level
pattern across the CONUS this morning. Main feature is longwave
troughing covering much of the county to the east of the continental
divide. Within this larger trough we find a closed upper low
spinning over the Ohio Valley and responsible for plenty of ongoing
winter precipitation from the Great Lakes to the NE states. The base
of this trough extends down to the northern Gulf coast and will
pivot across our region this morning. Early morning satellite
imagery shows areas of high level cirrus streaming across our skies
ahead of the trough axis and associated with upper level jet energy
aligned along the northern Gulf Coast.
At the surface,
Cold front which crossed the forecast area on Thursday continues to
move south and east over the FL peninsula. In the wake of this
front, a ridge of high pressure is building eastward along the Gulf
coast delivering a cooler and drier airmass. Temperatures will
continue a slow slide downward through the pre-dawn hours reaching
the lower/middle 30s by sunrise to the NW of a PC to Tallahassee to
Valdosta line, and upper 30s to low 40s further south and east.
&&
.SHORT TERM (TODAY THROUGH SUNDAY)...
Today,
High pressure centered over Texas will continue to ridge eastward to
our region through the day. The ridge will supply us with a fair,
dry, and cool forecast to end the work week. Will call it mostly
sunny, however there will be some passing cirrus this morning across
the Big Bend zones, and then additional cirrus arriving from the
west late in the day ahead of yet another mid-level shortwave. With
CAA ongoing this morning, temperatures will be slow to respond.
850mb temps will be lowering through the day, with the 0C line
dipping down close to KDHN and KABY. With this cooler low level
airmass in place, expecting high temperatures by mid afternoon to
generally reach the lower 50s (middle 50s down toward KCTY).
Tonight,
Gradient will weaken as the ridge axis continue to build closer to
the region. In terms of a radiational cooling setup, the high
position is certainly not ideal, however it isn`t terrible either.
It is likely that de-coupling of the boundary layer will eventually
take place, although it may take much of the night to occur. With
this in mind, do not anticipate much in the way of hard freeze
conditions, however much of the forecast area will experience
sub-freezing temperatures during the late night hours. Normally
colder locations under radiational cooling will briefly drop down
into the middle 20s around sunrise, with most other spots bottoming
out in the upper 20s to lower 30s.
Saturday/Sunday,
After the cold start Saturday morning, high pressure building
overhead will provide the region with a dry and seasonable weekend.
Airmass will begin to recover during Saturday as the longwave
mid-level trough begins to pull away to the NE. High temperatures
will respond, reaching the upper 50s for afternoon highs. The
overall airmass will not be as cool Saturday night, however the
surface high will be almost directly over the forecast area. This
more favorable high position combined with plenty of residual dry
air will allow for a good radiational cooling setup. Expecting
widespread low temperatures by sunrise to reside between 30-35
degrees. Normally colder spots...especially along the I-10 corridor
and Suwannee River Valley will have the potential to briefly reach
the upper 20s. Temperatures rebound further on Sunday after the cold
start, with 850mb temps climbing to 6-8C by the end of the day. With
the high position in close proximity, overall diurnal mixing will be
held in check, but should still be able to mix out our afternoon
temps into the lower/mid 60s.
&&
.LONG TERM (MONDAY THROUGH NEXT FRIDAY)...
The large scale longwave pattern commences fairly amplified. This is
highlighted in the Nrn stream by weak troughing across Wrn states
and extreme Wrn Atlc and ridging in between. Srn stream with weak
troughing Pac Coast to TX and ridging Ewd into extreme Wrn Atlc. At
surface, high along NC/VA coast with ridge axis swwd into
Apalachee Bay. Low in Canada N of MN with cold front Swwd into
Colorado. This place local area in very dry pattern.
During the rest of the period, Wrn upper trough digs Ewd while Srn
stream upper ridge moves offshore with Srn flow becoming nearly
zonal and stays so before weak troughing approaches shifting flow to
SWLY on Fri. At surface, Ewd moving UPR Nrn trough pushes surface
low moves to Srn Great Lakes kicking high into Atlc. Assocd cold
front dragged rapidly Sewd with deep sly flow setup from Gulf. Front
pushed thru CWA Tues night exiting Wed morn Ern zones bringing sct
shwrs and isold tstms Tues into Wed. In its wake strong high builds
SEWD from Srn Plains Ewd spreading a reinforcing shot of cold and
very dry air across local region Wed into Fri. By end of period high
pushed offshore with next low moving newd into TN valley dragging
trailing cold front to Wrn Gulf. In response, onshore flow with
increasing chances of rain commences again across local area by end
of Fri.
Forecast will show Sct pops Tues aftn into Wed. Otherwise nil pops
thru period. Ahead of the front min temps will be around 10 degrees
above climo Mon and Tues nights dropping to at or below climo Wed
and Thurs nights and may reach freezing in coldest locales. Max
temps commence at least 10 degrees above climo on Tues dropping to
at or below climo on Wed then inching up to a few degrees above
climo by Fri. Average inland min/max temps are 39/62.
&&
.MARINE
A ridge of high pressure will begin to build over the forecast
waters today in the wake of a cold front. Advisory level northwest
winds will diminish through the day, and expect the current advisory
to be dropped later this morning or early this afternoon. After a
round of cautionary level winds tonight, high pressure will build
overhead for much of the weekend keeping winds and seas below
headline criteria. Winds will begin to pick up once again out of the
east and southeast early next week as the ridge of high pressure
exits the region.
&&
.AVIATION (THROUGH 12Z SATURDAY)...
VFR conditions will prevail through the TAF period with only
periodic bands of high level cirrus crossing the sky. Winds have
calmed early this morning from the gusty conditions on Thursday,
however do expect NW/W gusts to pick back up later this morning into
the afternoon. The highest gusts will around around KDHN and KABY
with speeds approaching 20 knots will be possible. Further south for
KECP, KTLH, and KVLD gusts closer to 15 knots should be expected.
These winds will rapidly diminish toward sunset this evening.
&&
.FIRE WEATHER...
A very dry airmass will settle in across the region through
Saturday, with RH values dropping into the lower 20s each afternoon.
Durations of critical RH will be right around 4 hours across SE
AL/SW GA for both days with driest values across SE ALA and SW GA. A
Red Flag warning has been issued for the SE ALA/GA counties for this
afternoon. Altho critical RH values will be realized over N FL,
neither ERC, winds or dispersion red flag values will be realized so
no warning was issued. Similar conditions are expected on Saturday
and a fire weather watch remains in effect for the GA/AL counties.
The airmass will slowly moisten Sun thru Tues then dry out again on
Wed into Thurs in the wake of a cold front.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 52 27 58 29 65 / 0 0 0 0 0
Panama City 53 34 59 38 63 / 0 0 0 0 0
Dothan 51 29 59 33 62 / 0 0 0 0 0
Albany 51 27 58 31 61 / 0 0 0 0 0
Valdosta 52 27 57 31 61 / 0 0 0 0 0
Cross City 56 27 59 30 65 / 0 0 0 0 0
Apalachicola 52 35 57 34 63 / 0 0 0 0 0
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
AL...Red Flag Warning from Noon today to 4 PM CST this afternoon for
Coffee-Dale-Geneva-Henry-Houston.
Fire Weather Watch Saturday afternoon for Coffee-Dale-Geneva-
Henry-Houston.
GA...Red Flag Warning from 1 PM to 5 PM EST this afternoon for Baker-
Ben Hill-Berrien-Brooks-Calhoun-Clay-Colquitt-Cook-Decatur-
Dougherty-Early-Grady-Irwin-Lanier-Lee-Lowndes-Miller-
Mitchell-Quitman-Randolph-Seminole-Terrell-Thomas-Tift-
Turner-Worth.
Fire Weather Watch Saturday afternoon for Baker-Ben
Hill-Berrien-Brooks-Calhoun-Clay-Colquitt-Cook-Decatur-
Dougherty-Early-Grady-Irwin-Lanier-Lee-Lowndes-Miller-
Mitchell-Quitman-Randolph-Seminole-Terrell-Thomas-Tift-
Turner-Worth.
FL...None.
GM...Small Craft Advisory until Noon EST today for Apalachee Bay-
Coastal waters From Ochlockonee River to Apalachicola FL
out to 20 NM-Coastal waters from Suwannee River to Keaton
Beach FL out 20 NM-Coastal waters from Apalachicola to
Destin FL out 20 NM-Waters from Suwannee River to
Apalachicola FL from 20 to 60 NM-Waters from Apalachicola
to Destin FL from 20 to 60 NM.
&&
$$
SYNOPSIS/SHORT TERM/MARINE...MROCZKA
LONG TERM/AVIATION/FIRE WX...BLOCK
AREA FORECAST DISCUSSION...UPDATED FOR AVIATION SECTION
NWS TALLAHASSEE FL
508 AM EST FRI Jan 13 2012
.SYNOPSIS...
08Z water vapor and H4 RUC analysis shows an amplified upper level
pattern across the CONUS this morning. Main feature is longwave
troughing covering much of the county to the east of the continental
divide. Within this larger trough we find a closed upper low
spinning over the Ohio Valley and responsible for plenty of ongoing
winter precipitation from the Great Lakes to the NE states. The base
of this trough extends down to the northern Gulf coast and will
pivot across our region this morning. Early morning satellite
imagery shows areas of high level cirrus streaming across our skies
ahead of the trough axis and associated with upper level jet energy
aligned along the northern Gulf Coast.
At the surface,
Cold front which crossed the forecast area on Thursday continues to
move south and east over the FL peninsula. In the wake of this
front, a ridge of high pressure is building eastward along the Gulf
coast delivering a cooler and drier airmass. Temperatures will
continue a slow slide downward through the pre-dawn hours reaching
the lower/middle 30s by sunrise to the NW of a PC to Tallahassee to
Valdosta line, and upper 30s to low 40s further south and east.
&&
.SHORT TERM (TODAY THROUGH SUNDAY)...
Today,
High pressure centered over Texas will continue to ridge eastward to
our region through the day. The ridge will supply us with a fair,
dry, and cool forecast to end the work week. Will call it mostly
sunny, however there will be some passing cirrus this morning across
the Big Bend zones, and then additional cirrus arriving from the
west late in the day ahead of yet another mid-level shortwave. With
CAA ongoing this morning, temperatures will be slow to respond.
850mb temps will be lowering through the day, with the 0C line
dipping down close to KDHN and KABY. With this cooler low level
airmass in place, expecting high temperatures by mid afternoon to
generally reach the lower 50s (middle 50s down toward KCTY).
Tonight,
Gradient will weaken as the ridge axis continue to build closer to
the region. In terms of a radiational cooling setup, the high
position is certainly not ideal, however it isn`t terrible either.
It is likely that de-coupling of the boundary layer will eventually
take place, although it may take much of the night to occur. With
this in mind, do not anticipate much in the way of hard freeze
conditions, however much of the forecast area will experience
sub-freezing temperatures during the late night hours. Normally
colder locations under radiational cooling will briefly drop down
into the middle 20s around sunrise, with most other spots bottoming
out in the upper 20s to lower 30s.
Saturday/Sunday,
After the cold start Saturday morning, high pressure building
overhead will provide the region with a dry and seasonable weekend.
Airmass will begin to recover during Saturday as the longwave
mid-level trough begins to pull away to the NE. High temperatures
will respond, reaching the upper 50s for afternoon highs. The
overall airmass will not be as cool Saturday night, however the
surface high will be almost directly over the forecast area. This
more favorable high position combined with plenty of residual dry
air will allow for a good radiational cooling setup. Expecting
widespread low temperatures by sunrise to reside between 30-35
degrees. Normally colder spots...especially along the I-10 corridor
and Suwannee River Valley will have the potential to briefly reach
the upper 20s. Temperatures rebound further on Sunday after the cold
start, with 850mb temps climbing to 6-8C by the end of the day. With
the high position in close proximity, overall diurnal mixing will be
held in check, but should still be able to mix out our afternoon
temps into the lower/mid 60s.
&&
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY).
The large scale longwave pattern commences fairly amplified. This is
highlighted in the Nrn stream by weak troughing across Wrn states
and extreme Wrn Atlc and ridging in between. Srn stream with weak
troughing Pac Coast to TX and ridging Ewd into extreme Wrn Atlc. At
surface, high along NC/VA coast with ridge axis swwd into
Apalachee Bay. Low in Canada N of MN with cold front Swwd into
Colorado. This place local area in very dry pattern.
During the rest of the period, Wrn upper trough digs Ewd while Srn
stream upper ridge moves offshore with Srn flow becoming nearly
zonal and stays so before weak troughing approaches shifting flow to
SWLY on Fri. Second upper trough over Gulf digs rapidly ESE Tuesday
and Tuesday night. At surface, Above troughs push surface low moves
to Srn Great Lakes kicking high into Atlc. Assocd cold front with
limited instability dragged rapidly Sewd with deep sly flow setup
from Gulf. GFS and ECMWF similar in timing and intensity of
front pushed thru CWA Tues night exiting Wed morn Ern most zones
bringing sct shwrs and a few tstms Tues aftn into early Wed. In its
wake, strong high builds SEWD from Srn Plains Ewd spreading a
reinforcing shot of cold and very dry air across local region Wed
into Fri. By end of period high pushed offshore with next low moving
newd into TN valley dragging trailing cold front to Wrn Gulf. In
response, onshore flow with increasing chances of rain commences
again across local area by end of Fri.
Forecast will show Sct pops Tues aftn into Wed. Otherwise nil pops
thru period. Ahead of the front min temps will be around 10 degrees
above climo Mon and Tues nights dropping to at or below climo Wed
and Thurs nights and may reach freezing in coldest locales. Max
temps commence at least 10 degrees above climo on Tues dropping to
at or below climo on Wed then inching up to a few degrees above
climo by Fri. Average inland min/max temps are 39/62.
&&
.AVIATION (THROUGH 12Z SATURDAY)...
Wind speeds will continue to be in the 5 to 10 kt range and locally
gusty coast and ern most counties until around sunrise before
increasing to around 10kts with higher gusts mainly S/Cntrl GA until
it becomes near calm after sunset. Aside from a scattering of low
level clouds, expect only SCT-BKN cirrus to stream over the region
thru 12z Sat.
&&
.MARINE
A ridge of high pressure will begin to build over the forecast
waters today in the wake of a cold front. Advisory level northwest
winds will diminish through the day, and expect the current advisory
to be dropped later this morning or early this afternoon. After a
round of cautionary level winds tonight, high pressure will build
overhead for much of the weekend keeping winds and seas below
headline criteria. Winds will begin to pick up once again out of the
east and southeast early next week as the ridge of high pressure
exits the region.
&&
.FIRE WEATHER...
A very dry airmass will settle in across the region through
Saturday, with RH values dropping into the lower 20s each afternoon.
Durations of critical RH will be right around 4 hours across SE
AL/SW GA for both days with driest values across SE ALA and SW GA. A
Red Flag warning has been issued for the SE ALA/GA counties for this
afternoon. Altho critical RH values will be realized over N FL,
neither ERC, winds or dispersion red flag values will be realized so
no warning was issued. Similar conditions are expected on Saturday
and a fire weather watch remains in effect for the GA/AL counties.
The airmass will slowly moisten Sun thru Tues then dry out again on
Wed into Thurs in the wake of a cold front.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 52 27 58 29 65 / 0 0 0 0 0
Panama City 53 34 59 38 63 / 0 0 0 0 0
Dothan 51 29 59 33 62 / 0 0 0 0 0
Albany 51 27 58 31 61 / 0 0 0 0 0
Valdosta 52 27 57 31 61 / 0 0 0 0 0
Cross City 56 27 59 30 65 / 0 0 0 0 0
Apalachicola 52 35 57 34 63 / 0 0 0 0 0
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
AL...Red Flag Warning from Noon today to 4 PM CST this afternoon for
Coffee-Dale-Geneva-Henry-Houston.
Fire Weather Watch Saturday afternoon for Coffee-Dale-Geneva-
Henry-Houston.
GA...Red Flag Warning from 1 PM to 5 PM EST this afternoon for Baker-
Ben Hill-Berrien-Brooks-Calhoun-Clay-Colquitt-Cook-Decatur-
Dougherty-Early-Grady-Irwin-Lanier-Lee-Lowndes-Miller-
Mitchell-Quitman-Randolph-Seminole-Terrell-Thomas-Tift-
Turner-Worth.
Fire Weather Watch Saturday afternoon for Baker-Ben
Hill-Berrien-Brooks-Calhoun-Clay-Colquitt-Cook-Decatur-
Dougherty-Early-Grady-Irwin-Lanier-Lee-Lowndes-Miller-
Mitchell-Quitman-Randolph-Seminole-Terrell-Thomas-Tift-
Turner-Worth.
FL...None.
GM...Small Craft Advisory until Noon EST today for Apalachee Bay-
Coastal waters From Ochlockonee River to Apalachicola FL
out to 20 NM-Coastal waters from Suwannee River to Keaton
Beach FL out 20 NM-Coastal waters from Apalachicola to
Destin FL out 20 NM-Waters from Suwannee River to
Apalachicola FL from 20 to 60 NM-Waters from Apalachicola
to Destin FL from 20 to 60 NM.
&&
$$
SYNOPSIS/SHORT TERM/MARINE...MROCZKA
LONG TERM/AVIATION/FIRE WX...BLOCK
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1000 AM CST FRI JAN 13 2012
.UPDATE...
A SIGNIFICANT REVISION IS COMING TO THE OVERALL FCST. WATER VAPOR
SHOWS A NICE VORT MAX ROTATING SOUTHEAST ACROSS IOWA. RADAR
RETURNS ARE EXPANDING ACROSS THE AREA SHOWING -SN DEVELOPING PER
SFC OBS. A DUSTING HAS ALREADY OCCURRED IN THE CID METRO AREA.
PER THE RUC TRENDS...THERE IS WEAK F VECTOR CONVERGENCE ACROSS THE
AREA THAT MAINTAINS THROUGH THE AFTERNOON. FORCING IS WEAK BUT
THERE AND CONDENSATION PRESSURE DEFICITS ARE MODERATELY LOW IN THE
SHALLOW ARCTIC AIR.
BASED ON THIS THE FCST HAS BEEN REVISED TO GO WITH -SN FOR THE
REMAINDER OF THE DAY. ACCUMULATIONS SHOULD ONLY BE A DUSTING BUT
EMBEDDED SNOW SHOWERS MAY RESULT IN LOCALIZED HALF INCH ACCUMULATIONS.
AN UPDATED FCST WILL BE AVAILABLE SHORTLY.
..08..
&&
.AVIATION...
MVFR CONDITIONS CONTINUE ACROSS THE AREA. LIFT FROM AN UPPER LEVEL
DISTURBANCE IS ALLOWING -SN TO BREAK OUT WEST OF THE MISSISSIPPI
WITH MOVEMENT TO THE EAST. BASED ON TRENDS FROM THE RUC MODEL...
MVFR CIGS/VSBYS ARE LIKELY TO PERSIST UNTIL NEARLY 00Z/14. VFR
CONDITIONS ARE EXPECTED TO DVLP AFT 00Z/14.
..08..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DENVER CO
1032 AM MST FRI JAN 13 2012
.UPDATE...CURRENT FORECAST STILL ON TRACK AS NORTHWEST FLOW ALOFT
PERSISTS. GUSTY WINDS TO CONTINUE ACROSS MUCH OF THE AREA THROUGH
THE AFTERNOON WITH THE STRONGEST GUSTS OVER THE MOUNTAINS AND
ALONG THE FOOTHILLS. GUIDANCE AS WELL AS LOCAL SANGTER WIND MODEL SHOWING
WINDS TO REMAIN BELOW HIGH WIND CRITERIA. MODELS SHOW SOME
WEAKENING OF THE WINDS ACROSS PLAINS BY THIS EVENING...STILL
REMAINING GUSTY ALONG FOOTHILLS AND MOUNTAINS. ALL THIS REFLECTED
IN CURRENT GRIDS.
&&
.AVIATION...CURRENT TAF TRENDS STILL ON TRACK. LATEST RUC AND HRRR
STILL SHOW THAT PUSH OF NORTHWEST WINDS ACROSS THE AREA BETWEEN 20Z
AND 23Z. DID INCREASE THE WINDS A BIT OVERNIGHT AS SURFACE
GRADIENT SUGGESTS A BIT OF ENHANCED DRAINAGE.
&&
.PREV DISCUSSION... /ISSUED 321 AM MST FRI JAN 13 2012/
SHORT TERM...NW FLOW ALOFT WILL REMAIN OVER THE AREA THRU TONIGHT.
QUITE A BIT OF HIGHER LEVEL MOISTURE WILL MOVE ACROSS THE AREA TODAY
WITH PERIODS OF HIGHER LEVEL CLOUDS THRU THIS AFTN BUT NO PCPN.
CROSS-SECTIONS SHOW GUSTY NWLY WINDS WILL OCCUR IN THE
MTNS...FOOTHILLS AND ACROSS THE NERN PLAINS ESPECIALLY NR THE WY-NE
BORDER AREA. GUSTS MAY REACH THE 40-45 MPH RANGE THIS AFTN NR THE
WY-NE BORDER WITH 55-60 MPH IN THE FOOTHILLS AND HIGHER MTNS. AT
THIS TIME WINDS SHOULD STAY BLO WARNING CRITERIA. OTHER CONCERN
WOULD BE FIRE WEATHER POTENTIAL OVER PARTS OF THE NERN PLAINS
HOWEVER MODELS ARE SHOWING VARYING HUMIDITY LEVELS THIS AFTN SO NOT
SURE WHICH SOLUTIONS ARE RIGHT. THERE MAY BE A SMALL 3 HOUR WINDOW
FROM 20Z-23Z WHERE CONDITIONS MAY BE MET MAINLY ALONG THE WY-NE
BORDER. AS FAR AS TEMPS SHOULD CONTINUE TO SEE WARMER READINGS WITH
HIGHS IN THE 45 TO 50 DEGREE RANGE ACROSS NERN CO.
FOR TONIGHT NW FLOW WILL CONTINUE HOWEVER HIGHER LEVEL MOISTURE WILL
DECREASE SO HIGH LEVEL CLOUDINESS SHOULD DIMINISH. CROSS-SECTIONS
CONTINUE TO SHOW GUSTY WINDS OVER THE HIGHER MTNS AND FOOTHILLS
OVERNIGHT BUT SPEEDS SHOULD REMAIN BLO WARNING CRITERIA.
LONG TERM....UPPER RIDGING DOMINATES THE FORECAST AREA INTO MID DAY
SUNDAY...WITH NORTHWESTERLY FLOW ALOFT SATURDAY...BECOMING ZONAL
SATURDAY NIGHT INTO SUNDAY. BY LATER SUNDAY AFTERNOON AND NIGHT
..THE FLOW ALOFT BECOMES SOUTHWESTERLY WITH AN UPPER TROUGH MOVING
INTO THE GREAT BASIN FROM THE NORTHWEST. THE SYNOPTIC SCALE ENERGY
IS BENIGN SATURDAY INTO SUNDAY AFTERNOON...THEN WEAK QG ASCENT MOVES
IN LATE. BY MONDAY MORNING...THE UPWARD VERTICAL VELOCITY IS
PROGGED TO INCREASE. THE BOUNDARY LAYER FLOW WILL LIKELY BE
DOWNSLOPING IN NATURE SATURDAY THROUGH SUNDAY...WITH LOW LEVEL
TROUGHING EAST OF THE MOUNTAINS ALL WEEKEND. FOR MOISTURE...THERE
IS SOME IN THE MID AND UPPER LEVELS SATURDAY THROUGH SUNDAY...MORE
SO ON THE GFS. AFTER 06Z SUNDAY NIGHT...BOTH MODELS INCREASE
MOISTURE DRAMATICALLY OVER THE MOUNTAINS. THE QPF FIELDS SHOW NO
MEASURABLE PRECIPITATION OVER THE CWA SATURDAY THROUGH MIDNIGHT
SUNDAY NIGHT. THERE IS A TAD OVER THE MOUNTAINS WEST OF THE DIVIDE
PROGGED FROM 06Z TO 12Z MONDAY MORNING. NO POPS THROUGH SUNDAY
EVENING...THEN 20%S IN THE HIGH MOUNTAINS OVERNIGHT SUNDAY. FOR
TEMPERATURES...SATURDAY`S HIGHS ARE 3-4.5 C WARMER THAN TODAY`S.
SUNDAY`S HIGHS ARE 1-3 C WARMER THAN SATURDAY`S. FOR THE LATER
DAYS...MONDAY THROUGH THURSDAY...THE NAM...GFS...AND ECMWF ALL SHOW
AN UPPER TROUGH TO MOVE ACROSS THE CWA LATER MONDAY AND MONDAY
NIGHT. THERE IS MOISTURE...COLD AIR...AND UPSLOPE FOR THE PLAINS
AND FOOTHILLS. HOWEVER IT IS A QUICK SHOT. AFTER THE TROUGH AXIS
MOVES THROUGH...PRETTY STRONG NORTHWESTERLY FLOW ALOFT IS PROGGED TO
CONTINUE MUCH OF NEXT WEEK. THE GFS SHOWS FAIRLY DECENT MOISTURE IN
THE FLOW...BUT THE ECMWF HAS LESS. THIS TYPE OF PATTERN WOULD FAVOR
MOUNTAIN SNOWS OFF AND ON. WE`LL SEE. MONDAY AND TUESDAY LOOK
PRETTY COLD...WITH WARMING FOR WEDNESDAY AND THURSDAY.
AVIATION...OUTSIDE OF SOME HIGHER LEVEL CLOUDS VFR CONDITIONS WILL
BE IN PLACE THRU TONIGHT. WINDS THIS MORNING WILL BE SSW BUT WILL
SHIFT TO MORE WLY BY 17Z. IN THE AFTN BOTH THE RUC AND HRRR SO
A SURGE OF STRONGER WINDS COMING OFF THE FOOTHILLS FM THE WNW AROUND
20Z WITH GUSTS OF 25-30 MPH POSSIBLE FM 20Z-23Z. BY EARLY EVENING
WINDS SHOULD GRADUALLY BECOME MORE WSW WITH DECREASING SPEEDS AND
THEN WILL BECOME MORE SSW BY 06Z.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...D-L
LONG TERM....RJK
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS ALBANY NY
539 PM EST FRI JAN 13 2012
.SYNOPSIS...
LOW PRESSURE WILL DEEPEN AND INTENSIFY...AS IT MOVES
INTO THE CANADIAN MARITIMES TONIGHT. BLUSTERY AND COLD CONDITIONS
WILL CONTINUE OVERNIGHT WITH OCCASIONAL SNOW SHOWERS AND
FLURRIES...AS AN ARCTIC COLD FRONT MOVES THROUGH TOWARDS DAYBREAK.
ARCTIC HIGH PRESSURE WILL BUILD IN FROM SOUTHEASTERN ONTARIO LATE
SATURDAY INTO SUNDAY WITH SUBSIDING WINDS...BUT FRIGID TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 530 PM EST...WE ARE RECEIVING REPORTS OF 5-7 INCHES OF
SNOWFALL...AND UPSLOPE SNOWFALL IS REALLY CRANKING UP NOW ALONG
THE NRN-CNTRL TACONICS...BERKSHIRES AND SRN GREENS. WE JUST
RECEIVED A REPORT OF 5" IN DALTON...6.5" IN PITTSFIELD...7 INCHES IN SAVOY
AND LENOX...AND 6.5 INCHES IN WOODFORD VT. WE HAVE INCREASED NRN
BERKSHIRE CTY...BENNINGTON...AND WRN WINDHAM CTY VT TO WINTER
STORM WARNINGS FOR 6-12 INCHES OF HEAVY SNOW AND BLOWING SNOW. THE
UPSLOPE SNOWFALL LOOKS CLASSIC RIGHT NOW BASED ON THE KENX RADAR
RETURNS EAST OF THE I-90 CORRIDOR...AND NOW THAT THE UPPER LOW IS
OVER MAINE COUPLED WITH A SFC TROUGH MOVING OVER THE REGION. WE
INCREASED THE ADVISORY AMOUNTS FOR ERN RENSSELAER AND ERN COLUMBIA
COUNTIES TO 4-8" TOO.
PREVIOUS NEAR TERM...
AS OF 4 PM EST...THE WATER VAPOR LOOP THIS AFTERNOON HAS THE
POTENT H500 CLOSED LOW MOVING EAST OF NY INTO NEW ENGLAND. AN
IMPRESSIVE 125+KT H500 JET STREAK CONTINUES TO MOVE EAST OF NEW
ENGLAND THIS AFTERNOON. THE OCCLUDED FRONT TO THE INTENSIFYING SFC
LOW OVER SE QUEBEC BLASTED THROUGH THIS MORNING...WHICH HAS KICKED
OFF SOME SNOW SQUALLS...AND UPSLOPE SNOWFALL ALONG THE WRN SPINE
OF THE SRN GREENS MTNS...CNTRL-NRN TACONICS...AND THE BERKSHIRES.
THE LOW TO THE MID LEVEL DEFORMATION ZONE TO THE POTENT UPPER LOW
HAS CONTINUED THE SNOWFALL ALONG THE WRN DACKS...AND WRN-CNTRL MOHAWK
VALLEY.
THE UPSLOPE SNOWFALL IN ERN COLUMBIA...ERN RENSSELAER AND N-CNTRL
BERKSHIRE COUNTIES HAS BEEN IMPRESSIVE THIS AFTERNOON WITH A
REPORT OF 6 INCHES AT PERU IN THE BERKSHIRES AS OF 3 PM. SOME OF
THE KEY FEATURES FOR AN UPSLOPE SUBSYNOPTIC SNOWFALL EVENT WITH A
CLOSED LOW WERE IN PLACE WITH STRONG CYCLONIC VORTICITY
ADVECTION...COLD ADVECTION IN THE LOW LEVELS...MOIST LOW TO MID
LEVELS...AND PERSISTENT W/SW FLOW. USUALLY THIS OCCURS WHEN THE
UPPER LOW IS EAST OR NORTHEAST OF THE REGION PER THE BTV CSTAR
WORK. THIS IS A HYBRID TYPE CASE. THE LATEST FROM THE NAM12 AND
HRRR 3KM REF PRODUCT HAS THE SNOWFALL WINDING DOWN BETWEEN 00Z-
03Z. WE EXPANDED THE ADVISORY TO INCLUDE SRN BERKSHIRE CTY /JUST
NORTH THE MASS PIKE/...AS WELL AS INCLUDING THE NRN-CNTRL TACONICS.
THE SNOW REPORTS HAVE RANGED FROM 1-3 INCHES SO FAR IN
HERKIMER COUNTY AND SW HAMILTON CTY. SOME LAKE MOISTURE WILL
CONTINUE TO BE UTILIZED IN THE DEFORMATION ZONE. OROGRAPHIC
ENHANCEMENT WILL CONTINUE ALONG THE WRN DACKS. WE HAVE EXTENDED
THE WINTER WEATHER ADVISORY FOR THE SRN DACKS AND THE WRN MOHAWK
VALLEY UNTIL MIDNIGHT. BLUSTERY W/SW WINDS WILL PERSIST THIS
EVENING BLOWING THE SNOW AROUND. THE BETTER LIFT AND MOISTURE
CONVERGENCE HAS BEEN CLOSER TO THE LAKE SHORE AND OVER W-CNTRL NY
TODAY. WE PLACED THE HIGHEST SNOW TOTALS THERE OVER NRN HERKIMER
CTY WITH 4 TO 8 INCHES...AND HAVE GONE 3 TO 6 INCHES ELSEWHERE.
LOOKING AT THE BUFKIT SOUNDINGS FROM KSYR...KUCA...AND KRME...THE
INVERSION DOES LOWER TO 4-5 KFT AGL OVERNIGHT WHICH WILL DIMINISH
THE SNOW...AND THE SFC TO BOUNDARY LAYER FLOW BEGINS TO VEER MORE
TO THE NW /CLOSE TO A 300 DEGREE TRAJECTORY/ WITH THE PASSAGE OF
ANOTHER COLD FRONT /THE LEADING EDGE OF ARCTIC AIR/. THERE COULD BE
A QUICK LAKE EXTENSION DOWN THE MOHAWK VALLEY FOR SOME SCT SNOW
SHOWERS TOWARDS DAYBREAK. THE HRRR HINTS AT HIS POSSIBILITY. WE
WILL HAVE TO MONITOR IF THIS MATERIALIZES.
IN TERMS OF THE WIND ADVISORY...GUSTS HAVE GENERALLY BEEN 30-35
KTS...JUST SHORT OF WIND ADVISORY CRITERIA. HOWEVER...AS OF 4 PM
KALB JUST HAD A GUST TO 36 KTS...AND THE H925 WINDS DO INCREASE TO
35-40 KTS...AND THE H850 WINDS TO 50-60 KTS BY 00Z. WE ARE
CONCERNED A FEW GUSTS COULD REACH 40 KTS OR SO..IF WE MIX TO H925. THE
LOW LEVEL PRESSURE GRADIENT WILL BE INCREASING...AND THERE IS A SFC
TROUGH MOVING ACROSS THE REGION AT 21Z PER THE RUC. WE WILL KEEP
THE WIND ADVISORY UP UNTIL MIDNIGHT. THE WINDS WILL GRADUALLY EASE
SLIGHTLY AFTER MIDNIGHT FROM THE W AT 15-25 MPH WITH SOME GUSTS
AROUND 35 MPH.
A BATCH OF SNOW SHOWERS OR SQUALLS WILL MOVE ACROSS THE REGION
BWTN 21Z-00Z. THIS COULD PRODUCE A DUSTING TO A FEW INCHES OF
SNOWFALL IN THE NON-ADVISORY AREAS FROM THE CAPITAL REGION NORTH.
LOWS TONIGHT WILL BE CHILLY WITH 5-10F READINGS OVER THE
ADIRONDACK PARK...TEENS ELSEWHERE..EXCEPT LOWER TO MID 20S FROM
KALB SOUTH DOWN THE HUDSON RIVER VALLEY...AND EAST OF THE GREEN
MTNS.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
SATURDAY...ANOTHER BOUNDARY MOVES THROUGH DURING THE MORNING...AS
THE SFC TO BOUNDARY LAYER FLOW CONTINUES TO VEER TO THE NORTHWEST.
THERE MAYBE A FEW MULTIBANDS OFF LAKE ONTARIO MAINLY IMPACTING
CNTRL NY. THE BEST CHC OF ISOLATED TO SCT SNOW SHOWERS AND
FLURRIES WILL BE WEST OF THE HUDSON RIVER VALLEY. THE STRONG
SUBSIDENCE FROM THE ARCTIC HIGH BUILDING IN WILL TEND TO SQUASH ANY
FURTHER DEVELOPMENT OF THE LAKE EFFECT SNOW GETTING INTO MOST OF
THE REGION. ANY ACCUMULATIONS FOR THE WRN MOHAWK VALLEY/ERN
CATSKILLS SHOULD BE LIGHT. OTHERWISE...COLD ADVECTION CONTINUES
OVER THE REGION WITH H850 TEMPS FALLING TO -15C TO -20C. MAX
TEMPS WILL OCCUR EARLY TOMORROW WITH HIGHS IN THE 25-30F RANGE
SOUTH AND EAST OF THE CAPITAL REGION...AND MIDS TEENS TO L20S
NORTH AND WEST...EXCEPT OVER THE SRN DACKS...WHERE SOME SINGLE
DIGITS AND LOWER TEENS WILL BE COMMON. IT WILL STILL BE BLUSTERY
WITH WINDCHILLS IN THE SINGLE DIGITS AND TEENS...AND BELOW ZERO
NORTH AND WEST OF THE CAPITAL REGION.
SATURDAY NIGHT...TRICKY FORECAST HOW FAST THE WINDS DECOUPLE WITH
THE ARCTIC HIGH BUILDING IN. WE COULD FLIRT WITH SOME ADVISORY
LEVELS WIND CHILLS OVER THE SRN DACKS...IF WE MAINTAIN WINDS IN
EXCESS OF 5 MPH. WE WILL CONTINUE THE PREVIOUS FORECASTS MENTION
IN THE HWO. OVERALL...A BITTERLY COLD NIGHT IS EXPECTED WITH LOWS
IN THE SINGLE DIGITS FROM THE CAPITAL DISTRICT SOUTH AND
EAST...AND ZERO TO 10 BELOW NORTH AND WEST...EXCEPT 10-20 BELOW IN
THE SRN DACKS.
SUNDAY-SUNDAY NIGHT...ARCTIC HIGH PRESSURE BUILDS OVER NY AND NEW
ENGLAND ON SUNDAY. MOSTLY SUNNY AND COLD CONDITIONS WILL PREVAIL
WITH HIGHS IN THE TEENS TO L20S OVER MOST OF THE REGION...EXCEPT
SOME SINGLE DIGITS OVER THE SRN DACKS...AND THE SRN GREENS. WE
START TO WARM ADVECT SUNDAY NIGHT...AS THE HIGH SLOWLY SHIFTS
DOWNSTREAM OVER NRN NEW ENGLAND. SOME CIRRUS MAY CREEP IN AHEAD OF
A WARM FRONT OVER THE GREAT LAKES REGION...AND SE ONTARIO. LOWS
WILL NOT BE AS COLD WITH MAINLY SINGLE DIGITS FROM THE MOHAWK
VALLEY...CAPITAL REGION SOUTH...AND SOME ZERO TO 10 BELOW READINGS
NORTH.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
A TRANQUIL WEATHER PATTERN ON MONDAY WILL TRANSITION TO A MORE
ACTIVE PATTERN TOWARD THE END OF THE WORK WEEK. A RIDGE LOOKS TO BE
IN PLACE MONDAY MORNING BUT AS THE DAY PROGRESSES...A SHORTWAVE
TROUGH IN THE MIDWEST WILL ACT TO SHIFT THE RIDGE FROM NORTHEAST
INTO THE ATLANTIC COAST. THIS SHORTWAVE WILL PROGRESS TO THE EAST
TOWARD EASTERN OHIO/W PA LATE TUESDAY INTO EARLY WEDNESDAY. THIS LOW
WILL PRODUCE WINDY CONDITIONS WITH SUSTAINED WNW WINDS AT 15-20 KTS
AND GUSTS 20-25 KTS THROUGH LATE WEDNESDAY.
THE ECMWF AND GFS BOTH SHOW THE POSITIVE TILTED TROUGH BECOMING A
NEGATIVE TROUGH OVER THE OHIO VALLEY WEDNESDAY MORNING...WITH
CYCLOGENESIS AT THE SFC OVER THE GREAT LAKES AREA AT THIS TIME. THE
MODELS AT THIS TIME SHOWS A DECENT LOW PRESSURE SYSTEM OVER THE
LAKES AND WESTERN NY MOVING NORTHEAST ALONG THE NY/CANADA BORDER. AT
THIS TIME...MODEL FORECAST SOUNDINGS SHOW THE PRECIPITATION TYPE
OVER THE FA STARTING OUT AS SNOW. BUT WITH TEMPERATURES WARMING
THROUGHOUT THE DAY...AREAS IN THE IMMEDIATE CAPITAL REGION AND SOUTH
WILL LIKELY CHANGE TO RAIN. AREAS NORTH OF ALB WILL SEE SNOW OR A
WINTRY MIX...DEPENDING ON ELEVATION.
THE GFS MODEL HAS THE SFC LOW PRESSURE SYSTEM MOVING OUT OF THE
NORTHEAST MOVING FASTER BUT ALL OF THE MODELS HAVE THE LOW PRESSURE
SYSTEMS OUT OF THE REGION BY LATE WEDNESDAY. THIS WILL BE FOLLOWED
BY ANOTHER SYSTEM...BUT MODELS LACKING CONSENSUS FOR LATE THURSDAY
INTO FRIDAY. GFS SHOWING NEGATIVELY TILTED UPPER LEVEL TROUGH WHICH
DEVELOPS A COASTAL LOW OFF OF CAPE COD. MEANWHILE THE ECMWF SHOW THE
UPPER LEVEL TROUGH HANGING BACK WEST...THEN RETREATING UP INTO
CANADA. WILL HAVE TO KEEP AN EYE AS THIS SYSTEM DEVELOPS.
NEAR NORMAL MAX TEMPS WILL WARM ON TUESDAY FROM A WARM FRONT AHEAD
OF THE APPROACHING LOW...TO 10 DEGREES ABOVE NORMAL. THIS WILL BE
FOLLOWED BY A COLD FRONT ON TUESDAY AND A STRONG NW FLOW PRODUCING
SLIGHTLY BELOW NORMAL TEMPERATURES THROUGH THE REST OF THE PERIOD.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
A STRENGTHENING LOW PRESSURE SYSTEM NEAR MONTREAL IS BRINGING VERY
WINDY AND MUCH COLDER AIR TO THE REGION THIS AFTERNOON...WITH
SCATTERED TO NUMEROUS SNOW SHOWERS EXPECTED...ESP AT KGFL AND KALB.
BOTH VSBYS AND CIGS COULD BECOME IFR IN ANY SNOW SHOWERS OR EMBEDDED
HEAVIER SQUALLS THIS AFTERNOON. CIGS AT KGFL AND KALB WILL LIKELY
REMAIN MVFR THIS EVENING AS COLD CYCLONIC FLOW CONTINUES. SCATTERED
SNOW SHOWERS WILL CONTINUE OVERNIGHT AS WELL ALTHOUGH THE BEST
CHANCE FOR STEADY SNOW IS THIS AFTERNOON AND EVENING. THE SNOW
SHOWERS SHOULD BECOME LESS NUMEROUS OVERNIGHT...ALTHOUGH MAY LINGER
AT KALB THROUGH DAYBREAK SATURDAY.
WINDS WILL BE WESTERLY AT 15-25 KT...WITH SOME STRONGER GUSTS
POSSIBLE...WINDS WILL REMAIN STRONG/GUSTY THROUGH THIS
EVENING...BEFORE DIMINISHING SLIGHTLY LATER THIS EVENING...ESP AT
KPOU.
OUTLOOK...
FRI NT...MAINLY MVFR...WINDY. SCATTERED -SHSN.
SAT-MON...VFR...NO SIG WX.
MON NT-TUE...MVFR...CHC IFR -SHSN/-FZRA.
WED...VFR. NO SIG WX.
&&
.HYDROLOGY...
NO MAJOR PROBLEMS ARE EXPECTED ON THE MAIN STEM RIVERS OVER THE
NEXT 5 DAYS. THE ARCTIC AIR MASS WILL ALLOW ICE TO FORM AND CONTINUE TO
THICKEN ON MAIN STEM RIVERS...LAKES...AND OTHER BODIES OF WATER
THROUGH THE WEEKEND. TEMPERATURES WILL MODERATE BACK ABOVE NORMAL
BY TUESDAY.
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...WIND ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR CTZ001-013.
NY...WIND ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR NYZ032-033-
038>043-047>054-058>061-063>066-082>084.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR NYZ032-
033-038-042-054-061.
MA...WIND ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR MAZ001-025.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR MAZ025.
WINTER STORM WARNING UNTIL MIDNIGHT EST TONIGHT FOR MAZ001.
VT...WIND ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR VTZ013>015.
WINTER STORM WARNING UNTIL MIDNIGHT EST TONIGHT FOR VTZ013-014.
&&
$$
SYNOPSIS...WASULA
NEAR TERM...WASULA
SHORT TERM...WASULA
LONG TERM...KGM/LFM
AVIATION...SND
HYDROLOGY...WASULA
AREA FORECAST DISCUSSION
NWS ALBANY NY
439 PM EST FRI JAN 13 2012
.SYNOPSIS...
LOW PRESSURE WILL DEEPEN AND INTENSIFY...AS IT MOVES
INTO THE CANADIAN MARITIMES TONIGHT. BLUSTERY AND COLD CONDITIONS
WILL CONTINUE OVERNIGHT WITH OCCASIONAL SNOW SHOWERS AND
FLURRIES...AS AN ARCTIC COLD FRONT MOVES THROUGH TOWARDS DAYBREAK.
ARCTIC HIGH PRESSURE WILL BUILD IN FROM SOUTHEASTERN ONTARIO LATE
SATURDAY INTO SUNDAY WITH SUBSIDING WINDS...BUT FRIGID TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 4 PM EST...THE WATER VAPOR LOOP THIS AFTERNOON HAS THE
POTENT H500 CLOSED LOW MOVING EAST OF NY INTO NEW ENGLAND. AN
IMPRESSIVE 125+KT H500 JET STREAK CONTINUES TO MOVE EAST OF NEW
ENGLAND THIS AFTERNOON. THE OCCLUDED FRONT TO THE INTENSIFYING SFC
LOW OVER SE QUEBEC BLASTED THROUGH THIS MORNING...WHICH HAS KICKED
OFF SOME SNOW SQUALLS...AND UPSLOPE SNOWFALL ALONG THE WRN SPINE
OF THE SRN GREENS MTNS...CNTRL-NRN TACONICS...AND THE BERKSHIRES.
THE LOW TO THE MID LEVEL DEFORMATION ZONE TO THE POTENT UPPER LOW
HAS CONTINUED THE SNOWFALL ALONG THE WRN DACKS...AND WRN-CNTRL MOHAWK
VALLEY.
THE UPSLOPE SNOWFALL IN ERN COLUMBIA...ERN RENSSELAER AND N-CNTRL
BERKSHIRE COUNTIES HAS BEEN IMPRESSIVE THIS AFTERNOON WITH A
REPORT OF 6 INCHES AT PERU IN THE BERKSHIRES AS OF 3 PM. SOME OF
THE KEY FEATURES FOR AN UPSLOPE SUBSYNOPTIC SNOWFALL EVENT WITH A
CLOSED LOW WERE IN PLACE WITH STRONG CYCLONIC VORTICITY
ADVECTION...COLD ADVECTION IN THE LOW LEVELS...MOIST LOW TO MID
LEVELS...AND PERSISTENT W/SW FLOW. USUALLY THIS OCCURS WHEN THE
UPPER LOW IS EAST OR NORTHEAST OF THE REGION PER THE BTV CSTAR
WORK. THIS IS A HYBRID TYPE CASE. THE LATEST FROM THE NAM12 AND
HRRR 3KM REF PRODUCT HAS THE SNOWFALL WINDING DOWN BETWEEN 00Z-
03Z. WE EXPANDED THE ADVISORY TO INCLUDE SRN BERKSHIRE CTY /JUST
NORTH THE MASS PIKE/...AS WELL AS INCLUDING THE NRN-CNTRL TACONICS.
THE SNOW REPORTS HAVE RANGED FROM 1-3 INCHES SO FAR IN
HERKIMER COUNTY AND SW HAMILTON CTY. SOME LAKE MOISTURE WILL
CONTINUE TO BE UTILIZED IN THE DEFORMATION ZONE. OROGRAPHIC
ENHANCEMENT WILL CONTINUE ALONG THE WRN DACKS. WE HAVE EXTENDED
THE WINTER WEATHER ADVISORY FOR THE SRN DACKS AND THE WRN MOHAWK
VALLEY UNTIL MIDNIGHT. BLUSTERY W/SW WINDS WILL PERSIST THIS
EVENING BLOWING THE SNOW AROUND. THE BETTER LIFT AND MOISTURE
CONVERGENCE HAS BEEN CLOSER TO THE LAKE SHORE AND OVER W-CNTRL NY
TODAY. WE PLACED THE HIGHEST SNOW TOTALS THERE OVER NRN HERKIMER
CTY WITH 4 TO 8 INCHES...AND HAVE GONE 3 TO 6 INCHES ELSEWHERE.
LOOKING AT THE BUFKIT SOUNDINGS FROM KSYR...KUCA...AND KRME...THE
INVERSION DOES LOWER TO 4-5 KFT AGL OVERNIGHT WHICH WILL DIMINISH
THE SNOW...AND THE SFC TO BOUNDARY LAYER FLOW BEGINS TO VEER MORE
TO THE NW /CLOSE TO A 300 DEGREE TRAJECTORY/ WITH THE PASSAGE OF
ANOTHER COLD FRONT /THE LEADING EDGE OF ARCTIC AIR/. THERE COULD BE
A QUICK LAKE EXTENSION DOWN THE MOHAWK VALLEY FOR SOME SCT SNOW
SHOWERS TOWARDS DAYBREAK. THE HRRR HINTS AT HIS POSSIBILITY. WE
WILL HAVE TO MONITOR IF THIS MATERIALIZES.
IN TERMS OF THE WIND ADVISORY...GUSTS HAVE GENERALLY BEEN 30-35
KTS...JUST SHORT OF WIND ADVISORY CRITERIA. HOWEVER...AS OF 4 PM
KALB JUST HAD A GUST TO 36 KTS...AND THE H925 WINDS DO INCREASE TO
35-40 KTS...AND THE H850 WINDS TO 50-60 KTS BY 00Z. WE ARE
CONCERNED A FEW GUSTS COULD REACH 40 KTS OR SO..IF WE MIX TO H925. THE
LOW LEVEL PRESSURE GRADIENT WILL BE INCREASING...AND THERE IS A SFC
TROUGH MOVING ACROSS THE REGION AT 21Z PER THE RUC. WE WILL KEEP
THE WIND ADVISORY UP UNTIL MIDNIGHT. THE WINDS WILL GRADUALLY EASE
SLIGHTLY AFTER MIDNIGHT FROM THE W AT 15-25 MPH WITH SOME GUSTS
AROUND 35 MPH.
A BATCH OF SNOW SHOWERS OR SQUALLS WILL MOVE ACROSS THE REGION
BWTN 21Z-00Z. THIS COULD PRODUCE A DUSTING TO A FEW INCHES OF
SNOWFALL IN THE NON-ADVISORY AREAS FROM THE CAPITAL REGION NORTH.
LOWS TONIGHT WILL BE CHILLY WITH 5-10F READINGS OVER THE
ADIRONDACK PARK...TEENS ELSEWHERE..EXCEPT LOWER TO MID 20S FROM
KALB SOUTH DOWN THE HUDSON RIVER VALLEY...AND EAST OF THE GREEN
MTNS.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
SATURDAY...ANOTHER BOUNDARY MOVES THROUGH DURING THE MORNING...AS
THE SFC TO BOUNDARY LAYER FLOW CONTINUES TO VEER TO THE NORTHWEST.
THERE MAYBE A FEW MULTIBANDS OFF LAKE ONTARIO MAINLY IMPACTING
CNTRL NY. THE BEST CHC OF ISOLATED TO SCT SNOW SHOWERS AND
FLURRIES WILL BE WEST OF THE HUDSON RIVER VALLEY. THE STRONG
SUBSIDENCE FROM THE ARCTIC HIGH BUILDING IN WILL TEND TO SQUASH ANY
FURTHER DEVELOPMENT OF THE LAKE EFFECT SNOW GETTING INTO MOST OF
THE REGION. ANY ACCUMULATIONS FOR THE WRN MOHAWK VALLEY/ERN
CATSKILLS SHOULD BE LIGHT. OTHERWISE...COLD ADVECTION CONTINUES
OVER THE REGION WITH H850 TEMPS FALLING TO -15C TO -20C. MAX
TEMPS WILL OCCUR EARLY TOMORROW WITH HIGHS IN THE 25-30F RANGE
SOUTH AND EAST OF THE CAPITAL REGION...AND MIDS TEENS TO L20S
NORTH AND WEST...EXCEPT OVER THE SRN DACKS...WHERE SOME SINGLE
DIGITS AND LOWER TEENS WILL BE COMMON. IT WILL STILL BE BLUSTERY
WITH WINDCHILLS IN THE SINGLE DIGITS AND TEENS...AND BELOW ZERO
NORTH AND WEST OF THE CAPITAL REGION.
SATURDAY NIGHT...TRICKY FORECAST HOW FAST THE WINDS DECOUPLE WITH
THE ARCTIC HIGH BUILDING IN. WE COULD FLIRT WITH SOME ADVISORY
LEVELS WIND CHILLS OVER THE SRN DACKS...IF WE MAINTAIN WINDS IN
EXCESS OF 5 MPH. WE WILL CONTINUE THE PREVIOUS FORECASTS MENTION
IN THE HWO. OVERALL...A BITTERLY COLD NIGHT IS EXPECTED WITH LOWS
IN THE SINGLE DIGITS FROM THE CAPITAL DISTRICT SOUTH AND
EAST...AND ZERO TO 10 BELOW NORTH AND WEST...EXCEPT 10-20 BELOW IN
THE SRN DACKS.
SUNDAY-SUNDAY NIGHT...ARCTIC HIGH PRESSURE BUILDS OVER NY AND NEW
ENGLAND ON SUNDAY. MOSTLY SUNNY AND COLD CONDITIONS WILL PREVAIL
WITH HIGHS IN THE TEENS TO L20S OVER MOST OF THE REGION...EXCEPT
SOME SINGLE DIGITS OVER THE SRN DACKS...AND THE SRN GREENS. WE
START TO WARM ADVECT SUNDAY NIGHT...AS THE HIGH SLOWLY SHIFTS
DOWNSTREAM OVER NRN NEW ENGLAND. SOME CIRRUS MAY CREEP IN AHEAD OF
A WARM FRONT OVER THE GREAT LAKES REGION...AND SE ONTARIO. LOWS
WILL NOT BE AS COLD WITH MAINLY SINGLE DIGITS FROM THE MOHAWK
VALLEY...CAPITAL REGION SOUTH...AND SOME ZERO TO 10 BELOW READINGS
NORTH.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
A TRANQUIL WEATHER PATTERN ON MONDAY WILL TRANSITION TO A MORE
ACTIVE PATTERN TOWARD THE END OF THE WORK WEEK. A RIDGE LOOKS TO BE
IN PLACE MONDAY MORNING BUT AS THE DAY PROGRESSES...A SHORTWAVE
TROUGH IN THE MIDWEST WILL ACT TO SHIFT THE RIDGE FROM NORTHEAST
INTO THE ATLANTIC COAST. THIS SHORTWAVE WILL PROGRESS TO THE EAST
TOWARD EASTERN OHIO/W PA LATE TUESDAY INTO EARLY WEDNESDAY. THIS LOW
WILL PRODUCE WINDY CONDITIONS WITH SUSTAINED WNW WINDS AT 15-20 KTS
AND GUSTS 20-25 KTS THROUGH LATE WEDNESDAY.
THE ECMWF AND GFS BOTH SHOW THE POSITIVE TILTED TROUGH BECOMING A
NEGATIVE TROUGH OVER THE OHIO VALLEY WEDNESDAY MORNING...WITH
CYCLOGENESIS AT THE SFC OVER THE GREAT LAKES AREA AT THIS TIME. THE
MODELS AT THIS TIME SHOWS A DECENT LOW PRESSURE SYSTEM OVER THE
LAKES AND WESTERN NY MOVING NORTHEAST ALONG THE NY/CANADA BORDER. AT
THIS TIME...MODEL FORECAST SOUNDINGS SHOW THE PRECIPITATION TYPE
OVER THE FA STARTING OUT AS SNOW. BUT WITH TEMPERATURES WARMING
THROUGHOUT THE DAY...AREAS IN THE IMMEDIATE CAPITAL REGION AND SOUTH
WILL LIKELY CHANGE TO RAIN. AREAS NORTH OF ALB WILL SEE SNOW OR A
WINTRY MIX...DEPENDING ON ELEVATION.
THE GFS MODEL HAS THE SFC LOW PRESSURE SYSTEM MOVING OUT OF THE
NORTHEAST MOVING FASTER BUT ALL OF THE MODELS HAVE THE LOW PRESSURE
SYSTEMS OUT OF THE REGION BY LATE WEDNESDAY. THIS WILL BE FOLLOWED
BY ANOTHER SYSTEM...BUT MODELS LACKING CONSENSUS FOR LATE THURSDAY
INTO FRIDAY. GFS SHOWING NEGATIVELY TILTED UPPER LEVEL TROUGH WHICH
DEVELOPS A COASTAL LOW OFF OF CAPE COD. MEANWHILE THE ECMWF SHOW THE
UPPER LEVEL TROUGH HANGING BACK WEST...THEN RETREATING UP INTO
CANADA. WILL HAVE TO KEEP AN EYE AS THIS SYSTEM DEVELOPS.
NEAR NORMAL MAX TEMPS WILL WARM ON TUESDAY FROM A WARM FRONT AHEAD
OF THE APPROACHING LOW...TO 10 DEGREES ABOVE NORMAL. THIS WILL BE
FOLLOWED BY A COLD FRONT ON TUESDAY AND A STRONG NW FLOW PRODUCING
SLIGHTLY BELOW NORMAL TEMPERATURES THROUGH THE REST OF THE PERIOD.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
A STRENGTHENING LOW PRESSURE SYSTEM NEAR MONTREAL IS BRINGING VERY
WINDY AND MUCH COLDER AIR TO THE REGION THIS AFTERNOON...WITH
SCATTERED TO NUMEROUS SNOW SHOWERS EXPECTED...ESP AT KGFL AND KALB.
BOTH VSBYS AND CIGS COULD BECOME IFR IN ANY SNOW SHOWERS OR EMBEDDED
HEAVIER SQUALLS THIS AFTERNOON. CIGS AT KGFL AND KALB WILL LIKELY
REMAIN MVFR THIS EVENING AS COLD CYCLONIC FLOW CONTINUES. SCATTERED
SNOW SHOWERS WILL CONTINUE OVERNIGHT AS WELL ALTHOUGH THE BEST
CHANCE FOR STEADY SNOW IS THIS AFTERNOON AND EVENING. THE SNOW
SHOWERS SHOULD BECOME LESS NUMEROUS OVERNIGHT...ALTHOUGH MAY LINGER
AT KALB THROUGH DAYBREAK SATURDAY.
WINDS WILL BE WESTERLY AT 15-25 KT...WITH SOME STRONGER GUSTS
POSSIBLE...WINDS WILL REMAIN STRONG/GUSTY THROUGH THIS
EVENING...BEFORE DIMINISHING SLIGHTLY LATER THIS EVENING...ESP AT
KPOU.
OUTLOOK...
FRI NT...MAINLY MVFR...WINDY. SCATTERED -SHSN.
SAT-MON...VFR...NO SIG WX.
MON NT-TUE...MVFR...CHC IFR -SHSN/-FZRA.
WED...VFR. NO SIG WX.
&&
.HYDROLOGY...
NO MAJOR PROBLEMS ARE EXPECTED ON THE MAIN STEM RIVERS OVER THE
NEXT 5 DAYS. THE ARCTIC AIR MASS WILL ALLOW ICE TO FORM AND CONTINUE TO
THICKEN ON MAIN STEM RIVERS...LAKES...AND OTHER BODIES OF WATER
THROUGH THE WEEKEND. TEMPERATURES WILL MODERATE BACK ABOVE NORMAL
BY TUESDAY.
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...WIND ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR CTZ001-013.
NY...WIND ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR NYZ032-033-
038>043-047>054-058>061-063>066-082>084.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR NYZ032-
033-038-042-054-061.
MA...WIND ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR MAZ001-025.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR MAZ001-
025.
VT...WIND ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR VTZ013>015.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR VTZ013-
014.
&&
$$
SYNOPSIS...WASULA
NEAR TERM...WASULA
SHORT TERM...WASULA
LONG TERM...KGM/LFM
AVIATION...SND
HYDROLOGY...WASULA
AREA FORECAST DISCUSSION
NWS NEW YORK NY
111 PM EST FRI JAN 13 2012
.SYNOPSIS...
LOW PRESSURE WILL TRACK DOWN THE SAINT LAWRENCE THROUGH
TONIGHT...WITH AN ASSOCIATED SECONDARY COLD APPROACHING THE TRI-
STATE LATE TONIGHT...AND PUSHING ACROSS THE AREA SATURDAY. HIGH
PRESSURE BUILDS IN BEHIND THE DEPARTING STORM SYSTEM SATURDAY
THROUGH EARLY NEXT WEEK. ANOTHER STORM SYSTEM AFFECTS THE AREA
MONDAY NIGHT THROUGH TUESDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AT 17Z...A VIGOROUS COLD FRONT WAS LOCATED NEAR THE WESTERN RI/MA
BORDER. PER LATEST WATER VAPOR...JET STREAK HAS PASSED TO THE
EAST...AND 500 HPA RUC ANALYSIS SHOWS NEGATIVE VORTICITY ADVECTION
OVER THE AREA. SO WHILE SOME ISOLD FLURRIES CANNOT BE RULED
OUT...BASICALLY GOING WITH A DRY FORECAST...WITH THE EXCEPTION OF
FAR NW ZONES...WHERE HAVE SLIGHT CHANCE FOR LAKE EFFECT SNOW
SHOWERS THIS AFTERNOON. LITTLE OR NO ACCUMULATION EXPECTED WITH THESE.
WITH RECENT PEAK WIND GUSTS TO 40 KT AT KPHI AND 41 KT AT
KFIG...WILL CONTINUE WIND ADVISORY AS IS FOR NOW...THOUGH APPEARS
POTENTIAL FOR REACHING IS MARGINAL ACROSS INTERIOR ZONES (NOTING
PEAK GUSTS ONLY TO 37 KT AT KMPO).
TEMPERATURES FALLING FAIRLY RAPIDLY BEHIND THE FRONT...WITH HIGHS
FOR TODAY REACHED JUST AHEAD OF THE FRONT THIS MORNING. NAM
2-METER TEMPERATURES ARE HANDLING THIS VERY WELL...AND HAVE BEEN
USED TO UPDATE HOURLY TEMPERATURE GRIDS THIS AFTERNOON. ALL AREAS
SHOULD BE INTO THE 30S BY LATE AFTERNOON...WITH NW PORTIONS OF THE
CWA FALLING INTO THE M-U 20S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
COLD ADVECTION CONTINUES TONIGHT BUT IS WEAKEN THAN DURING EARLY
THIS MORNING. ALSO WINDS ALOFT...900 MB TO 850 MB...DIMINISH
QUICKLY THIS EVENING. WILL CONTINUE TO WIND ADVISORY AS POSTED
THROUGH MIDNIGHT...HOWEVER WINDS COULD FALL BELOW ADVISORY LEVELS
EARLY IN THE EVENING.
UPPER TROUGH REMAINS IN THE AREA TONIGHT THROUGH SATURDAY AS SHORT
WAVES ROTATE THROUGH. CYCLONIC FLOW CONTINUES IN THE AREA AS
SURFACE LOW MOVES SLOWLY TO THE NORTHEAST THROUGH THE PERIOD.
PRECIPITATION IS NOT EXPECTED HOWEVER WITH MOISTURE IN THE AREA
VARYING CLOUDINESS IS EXPECTED.
USED THE NAM GUIDANCE FOR TEMPERATURES THROUGH SATURDAY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
JET STREAM SOUTH OF THE REGION SIGNALING COLD AIR MASS ENTRENCHED
ACROSS THE AREA WITH A TROUGH INDICATED AT 500 MB. HOWEVER...THIS
WILL BE A PROGRESSIVE PATTERN AS TROUGH AXIS SLIDES THROUGH ON
SUNDAY. SECONDARY COLD FRONT JUST MOVING SOUTH OF REGION SAT NIGHT
WITH HIGH PRESSURE BUILDING IN FROM THE WEST AT THE SURFACE.
NORTHWEST FLOW WILL CONTINUE TO REINFORCE THE COLD AIR ADVECTION.
RIDGING WILL THEN TAKE PLACE SUNDAY NIGHT WITH HEIGHT RISES AS TEMPS
INCREASE AT 850 MB. SFC HIGH PRESSURE CENTERS OVER THE AREA WITH
GOOD RADIATIONAL COOLING CONDITIONS EXPECTED.
FAVORED MET GUIDANCE IN THIS TIME FRAME WITH BELOW NORMAL
TEMPERATURES EXPECTED. LOWS WITH BETTER COLD AIR ADVECTION SAT NIGHT
BUT BREEZY CONDITIONS WILL BE SIMILAR TO SUN NIGHT LOWS WITH THAT
NIGHT HAVING BETTER RADIATIONAL COOLING AS WINDS LIGHTEN WITH THE
DECREASED PRESSURE GRADIENT.
HIGH PRESSURE AND RIDGING MOVES OFFSHORE ON MONDAY WITH A RETURN
SOUTHERLY FLOW DEVELOPING. TEMPERATURES MONDAY AND MONDAY NIGHT
SHOULD BE NEAR NORMAL LEVELS. FORECAST FAVORED THE GFS NEAR THIS
TIME FRAME. KEPT A SMALLER SPREAD OF TEMPERATURES MONDAY NIGHT AND
SLIGHTLY WARMER NEAR THE COAST WITH THE SOUTHERLY FLOW.
THERE WILL BE AN INCREASING CHANCE OF PRECIP WITH AN ADVANCING COLD
FRONT ACCOMPANYING ALOFT BY A POSITIVELY TILTED DIGGING TROUGH WEST
OF THE APPALACHIANS. INCREASED POPS NEAR 50 PERCENT HERE AS DECENT
QUASI-GEOSTROPHIC FORCING SHOWN BY MODELS WITH Q VECTOR CONVERGENCE
BETWEEN 850 AND 500 MB. COULD BE A COMPLEX WINTER WX SCENARIO
SHAPING UP FOR THE INTERIOR AS THE WARMER AIR ALOFT AT 850 MB
INCREASES NEAR TO A FEW DEGREES ABOVE FREEZING. WITH INTERIOR
TEMPS STILL AT OR BELOW FREEZING AND NOT AS INFLUENCED BY THE
SOUTHERLY FLOW...A PERIOD OF FROZEN PRECIP CONSISTING OF
SNOW...SLEET...AND/OR FREEZING RAIN WOULD BE POSSIBLE. KEPT
LOCATIONS NEAR THE COAST TO JUST PLAIN RAIN WITH THE SOUTHERLY
FLOW.
WARM AIR EVENTUALLY SPREADS ACROSS ENTIRE FORECAST REGION BY LATER
TUESDAY MORNING AND ALLOWS FOR PRECIP TO BE MAINLY RAIN THEREAFTER.
THE COLD FRONT PUSHES THROUGH BY LATE TUESDAY NIGHT WITH A LOWERED
TREND TO RAIN SHOWERS WHICH COULD MIX WITH AND CHANCE TO SNOW
SHOWERS ESPECIALLY FARTHER INLAND AT THE TAIL END OF THE PRECIP
RIGHT BEHIND THE COLD FRONT. WITH COLDER AIR COMING INTO PLACE AS
WELL ALOFT...THIS MAKES FOR A MORE SIMPLE SCENARIO OF A MIX OF RAIN
AND SNOW SHOWERS.
KEPT SLIGHT CHANCE POPS FOR SNOW AND RAIN SHOWERS ON WEDNESDAY AND
THURSDAY BECAUSE BEHIND THE COLD FRONT A BROAD UPPER LEVEL TROUGH
HANGS ON IN THE AREA WITH AN EMBEDDED SHORTWAVE/VORTICITY MAXIMUM
PUSHING THROUGH LATER ON WEDNESDAY AS WELL AS THURSDAY.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
HIGH PRESSURE SLOWLY BUILDS IN THIS AFTERNOON.
VFR...HOWEVER BRIEF MVFR CIGS POSSIBLE THIS AFTERNOON.
FOR ALL TERMINALS...THERE IS A CHANCE OF FLURRIES OR BRIEF LIGHT
SNOW SHOWERS NOW THROUGH 21Z-22Z. THIS IS NOT HOWEVER EXPECTED TO
ACCUMULATE ON RUNWAYS OR CAUSE SUB-VFR VISIBILITIES AT GROUND
LEVEL. THE DURATION AND COVERAGE OF THE FLURRIES/SNOW SHOWERS ARE
NOT ENOUGH TO WARRANT INCLUSION AS EVEN IN A TEMPO GROUP.
MEDIUM TO HIGH CONFIDENCE IN WIND DIRECTION. SUSTAINED/GUST
MAGNITUDES MAY BE OFF BY AROUND 5 KT AT TIMES.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KEWR FCSTER COMMENTS: OCCASIONAL GUSTS UP TO 41-44 KTS POSSIBLE
THIS AFTERNOON.
KJFK FCSTER COMMENTS: SUSTAINED WINDS OF 30-33 KT POSSIBLE AT
TIMES UNTIL AROUND 20Z. OCCASIONAL GUSTS UP TO 44-47 KTS POSSIBLE
THIS AFTERNOON.
KLGA FCSTER COMMENTS: OCCASIONAL GUSTS UP TO 39-42 KTS POSSIBLE
THIS AFTERNOON.
KTEB FCSTER COMMENTS: OCCASIONAL GUSTS 36-39 KTS POSSIBLE THROUGH
THIS AFTERNOON.
KHPN FCSTER COMMENTS: SUSTAINED WINDS AND GUSTS FORECAST MAY BE
AROUND 5 KT TOO HIGH THIS AFTERNOON.
KISP FCSTER COMMENTS: OCCASIONAL UP TO 37-40 KTS POSSIBLE THIS
AFTERNOON.
OUTLOOK FOR 18Z SATURDAY THROUGH WEDNESDAY...
SAT PM...VFR. FLURRIES POSSIBLE EARLY. GUSTY NW-W WINDS 20-25 KT.
SUN-MON...VFR.
TUE...SUB VFR POSSIBLE IN RAIN/MORNING WINTRY PRECIP.
WED...SUB VFR WITH WINTRY MIX POSSIBLE AM. GUSTY NW WINDS 20-25 KT
POSSIBLE.
&&
.MARINE...
GUSTS TO GALE FORCE BEHIND THE EXITING COLD FRONT EXPECTED INTO THIS
EVENING...THOUGH NOT NECESSARILY ALL THE TIME. WILL CONTINUE WITH
GALE WARNING AS AS...WITH GALE WARNING THROUGH THE OVERNIGHT HOURS
ACROSS THE OCEAN WATERS EAST OF FIRE ISLAND INLET.
ONCE THE WINDS DIMINISH ON THE REMAINDER OF THE FORECAST WATERS
THIS EVENING...SMALL CRAFT WIND GUSTS WILL CONTINUE THROUGH MUCH OF
THE OVERNIGHT. AND SMALL CRAFT WINDS WILL BE LIKELY ON THE OCEAN
WATERS INTO SATURDAY AFTERNOON...WITH SEAS REMAINING ABOVE 5 FT INTO
SATURDAY NIGHT.
STRONG OFF SHORE FLOW THROUGH TODAY WILL PUSH WATER OUT OF THE
WESTERN LONG ISLAND SOUND. THIS WILL RESULT IN LOW WATER PROBLEMS
DURING LOW TIDE THIS EVENING AND A LOW WATER ADVISORY HAS BEEN
ISSUED.
MARGINAL SCA WIND GUSTS REMAINING ON THE OUTER OCEAN WATERS THROUGH
SAT NIGHT BEFORE ENDING SUN MORNING. SUB SCA CONDITIONS THEN
EXPECTED THROUGH MON. MON NIGHT...OUT AHEAD OF NEXT COLD
FRONT...SOUTHERLY FLOW WILL LEAD TO A RETURN OF WIND GUSTS AND SEAS
TO SCA LEVELS WHICH COULD VERY WELL CONTINUE THROUGH THE REMAINDER
OF THE FORECAST.
&&
.HYDROLOGY...
AROUND A TENTH OF AN INCH OF RAINFALL IS POSSIBLE THROUGH EARLY THIS
AFTERNOON. DRY WEATHER RETURNS TONIGHT AND CONTINUES THROUGH MONDAY.
&&
.TIDES/COASTAL FLOODING...
STRONG AND GUSTY SOUTHWESTERLY WINDS DEVELOPING THIS MORNING AND
CONTINUING THROUGH THE DAY WILL PUSH WATER OUT OF THE WESTERN LONG
ISLAND SOUND. BY THE TIME OF THE LOW TIDE EARLY THIS EVENING TIDAL
DEPARTURES ARE EXPECTED TO RUN 3 TO 3 1/2 FT BELOW NORMAL. THIS
WILL RESULT IN LOW WATER PROBLEMS AND A LOW WATER ADVISORY HAS
BEEN ISSUED.
LATEST TRENDS IN OBSERVATIONS BEGINNING TO GIVE CONCERN ABOUT LOW
WATER IN NEW YORK HARBOR AND THE SOUTH SHORE BAYS AS WELL FOR
SATURDAY MORNINGS LOW TIDE. WILL CONTINUE TO EVALUATE.
&&
.EQUIPMENT...
THE KOKX WSR-88D WILL BE DOWN FOR THE INSTALLATION OF DUAL
POLARIZATION SOFTWARE AND HARDWARE THROUGH JANUARY 24TH.
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...WIND ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR CTZ005>012.
NY...WIND ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR NYZ067>075-
078>081-176>179.
NJ...WIND ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR NJZ002-004-006-
103>108.
MARINE...GALE WARNING UNTIL MIDNIGHT EST TONIGHT FOR ANZ330-335-338-340-
345-355.
LOW WATER ADVISORY FROM 6 PM TO 11 PM EST THIS EVENING FOR
ANZ335.
GALE WARNING UNTIL 5 AM EST SATURDAY FOR ANZ350-353.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...WIND ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR CTZ005>012.
NY...WIND ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR NYZ067>075-
078>081-176>179.
NJ...WIND ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR NJZ002-004-006-
103>108.
MARINE...GALE WARNING UNTIL MIDNIGHT EST TONIGHT FOR ANZ330-335-338-340-
345-355.
LOW WATER ADVISORY FROM 6 PM TO 11 PM EST THIS EVENING FOR
ANZ335.
GALE WARNING UNTIL 5 AM EST SATURDAY FOR ANZ350-353.
&&
$$
AVIATION...JC
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1218 PM EST FRI JAN 13 2012
.SYNOPSIS...
LOW PRESSURE WILL TRACK DOWN THE SAINT LAWRENCE THROUGH
TONIGHT...WITH AN ASSOCIATED SECONDARY COLD APPROACHING THE TRI-
STATE LATE TONIGHT...AND PUSHING ACROSS THE AREA SATURDAY. HIGH
PRESSURE BUILDS IN BEHIND THE DEPARTING STORM SYSTEM SATURDAY
THROUGH EARLY NEXT WEEK. ANOTHER STORM SYSTEM AFFECTS THE AREA
MONDAY NIGHT THROUGH TUESDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AT 17Z...A VIGOROUS COLD FRONT WAS LOCATED NEAR THE WESTERN RI/MA
BORDER. PER LATEST WATER VAPOR...JET STREAK HAS PASSED TO THE
EAST...AND 500 HPA RUC ANALYSIS SHOWS NEGATIVE VORTICITY ADVECTION
OVER THE AREA. SO WHILE SOME ISOLD FLURRIES CANNOT BE RULED
OUT...BASICALLY GOING WITH A DRY FORECAST...WITH THE EXCEPTION OF
FAR NW ZONES...WHERE HAVE SLIGHT CHANCE FOR LAKE EFFECT SNOW
SHOWERS THIS AFTERNOON. LITTLE OR NO ACCUMULATION EXPECTED WITH THESE.
WITH RECENT PEAK WIND GUSTS TO 40 KT AT KPHI AND 41 KT AT
KFIG...WILL CONTINUE WIND ADVISORY AS IS FOR NOW...THOUGH APPEARS
POTENTIAL FOR REACHING IS MARGINAL ACROSS INTERIOR ZONES (NOTING
PEAK GUSTS ONLY TO 37 KT AT KMPO).
TEMPERATURES FALLING FAIRLY RAPIDLY BEHIND THE FRONT...WITH HIGHS
FOR TODAY REACHED JUST AHEAD OF THE FRONT THIS MORNING. NAM
2-METER TEMPERATURES ARE HANDLING THIS VERY WELL...AND HAVE BEEN
USED TO UPDATE HOURLY TEMPERATURE GRIDS THIS AFTERNOON. ALL AREAS
SHOULD BE INTO THE 30S BY LATE AFTERNOON...WITH NW PORTIONS OF THE
CWA FALLING INTO THE M-U 20S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
COLD ADVECTION CONTINUES TONIGHT BUT IS WEAKEN THAN DURING EARLY
THIS MORNING. ALSO WINDS ALOFT...900 MB TO 850 MB...DIMINISH
QUICKLY THIS EVENING. WILL CONTINUE TO WIND ADVISORY AS POSTED
THROUGH MIDNIGHT...HOWEVER WINDS COULD FALL BELOW ADVISORY LEVELS
EARLY IN THE EVENING.
UPPER TROUGH REMAINS IN THE AREA TONIGHT THROUGH SATURDAY AS SHORT
WAVES ROTATE THROUGH. CYCLONIC FLOW CONTINUES IN THE AREA AS
SURFACE LOW MOVES SLOWLY TO THE NORTHEAST THROUGH THE PERIOD.
PRECIPITATION IS NOT EXPECTED HOWEVER WITH MOISTURE IN THE AREA
VARYING CLOUDINESS IS EXPECTED.
USED THE NAM GUIDANCE FOR TEMPERATURES THROUGH SATURDAY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
JET STREAM SOUTH OF THE REGION SIGNALING COLD AIR MASS ENTRENCHED
ACROSS THE AREA WITH A TROUGH INDICATED AT 500 MB. HOWEVER...THIS
WILL BE A PROGRESSIVE PATTERN AS TROUGH AXIS SLIDES THROUGH ON
SUNDAY. SECONDARY COLD FRONT JUST MOVING SOUTH OF REGION SAT NIGHT
WITH HIGH PRESSURE BUILDING IN FROM THE WEST AT THE SURFACE.
NORTHWEST FLOW WILL CONTINUE TO REINFORCE THE COLD AIR ADVECTION.
RIDGING WILL THEN TAKE PLACE SUNDAY NIGHT WITH HEIGHT RISES AS TEMPS
INCREASE AT 850 MB. SFC HIGH PRESSURE CENTERS OVER THE AREA WITH
GOOD RADIATIONAL COOLING CONDITIONS EXPECTED.
FAVORED MET GUIDANCE IN THIS TIME FRAME WITH BELOW NORMAL
TEMPERATURES EXPECTED. LOWS WITH BETTER COLD AIR ADVECTION SAT NIGHT
BUT BREEZY CONDITIONS WILL BE SIMILAR TO SUN NIGHT LOWS WITH THAT
NIGHT HAVING BETTER RADIATIONAL COOLING AS WINDS LIGHTEN WITH THE
DECREASED PRESSURE GRADIENT.
HIGH PRESSURE AND RIDGING MOVES OFFSHORE ON MONDAY WITH A RETURN
SOUTHERLY FLOW DEVELOPING. TEMPERATURES MONDAY AND MONDAY NIGHT
SHOULD BE NEAR NORMAL LEVELS. FORECAST FAVORED THE GFS NEAR THIS
TIME FRAME. KEPT A SMALLER SPREAD OF TEMPERATURES MONDAY NIGHT AND
SLIGHTLY WARMER NEAR THE COAST WITH THE SOUTHERLY FLOW.
THERE WILL BE AN INCREASING CHANCE OF PRECIP WITH AN ADVANCING COLD
FRONT ACCOMPANYING ALOFT BY A POSITIVELY TILTED DIGGING TROUGH WEST
OF THE APPALACHIANS. INCREASED POPS NEAR 50 PERCENT HERE AS DECENT
QUASI-GEOSTROPHIC FORCING SHOWN BY MODELS WITH Q VECTOR CONVERGENCE
BETWEEN 850 AND 500 MB. COULD BE A COMPLEX WINTER WX SCENARIO
SHAPING UP FOR THE INTERIOR AS THE WARMER AIR ALOFT AT 850 MB
INCREASES NEAR TO A FEW DEGREES ABOVE FREEZING. WITH INTERIOR
TEMPS STILL AT OR BELOW FREEZING AND NOT AS INFLUENCED BY THE
SOUTHERLY FLOW...A PERIOD OF FROZEN PRECIP CONSISTING OF
SNOW...SLEET...AND/OR FREEZING RAIN WOULD BE POSSIBLE. KEPT
LOCATIONS NEAR THE COAST TO JUST PLAIN RAIN WITH THE SOUTHERLY
FLOW.
WARM AIR EVENTUALLY SPREADS ACROSS ENTIRE FORECAST REGION BY LATER
TUESDAY MORNING AND ALLOWS FOR PRECIP TO BE MAINLY RAIN THEREAFTER.
THE COLD FRONT PUSHES THROUGH BY LATE TUESDAY NIGHT WITH A LOWERED
TREND TO RAIN SHOWERS WHICH COULD MIX WITH AND CHANCE TO SNOW
SHOWERS ESPECIALLY FARTHER INLAND AT THE TAIL END OF THE PRECIP
RIGHT BEHIND THE COLD FRONT. WITH COLDER AIR COMING INTO PLACE AS
WELL ALOFT...THIS MAKES FOR A MORE SIMPLE SCENARIO OF A MIX OF RAIN
AND SNOW SHOWERS.
KEPT SLIGHT CHANCE POPS FOR SNOW AND RAIN SHOWERS ON WEDNESDAY AND
THURSDAY BECAUSE BEHIND THE COLD FRONT A BROAD UPPER LEVEL TROUGH
HANGS ON IN THE AREA WITH AN EMBEDDED SHORTWAVE/VORTICITY MAXIMUM
PUSHING THROUGH LATER ON WEDNESDAY AS WELL AS THURSDAY.
&&
.AVIATION /17Z FRIDAY THROUGH TUESDAY/...
HIGH PRESSURE SLOWLY BUILDS IN BEHIND A COLD FRONT OFF TO THE EAST.
VFR...HOWEVER BRIEF MVFR POSSIBLE UNTIL NOON. COULD BE BRIEF MVFR
CIGS THIS AFTERNOON AS WELL...BUT NOT ENOUGH CONFIDENCE TO PUT
INTO TAFS AT THIS TIME.
IN GENERAL...FORECAST SUSTAINED AND GUSTS MAY BE OFF BY AROUND 5
KT THROUGH THE DAY. MODERATE TO HIGH CONFIDENCE IN WIND DIRECTION.
BATCH OF PRECIP THAT IS NOW JUST EAST OF THE CITY TERMINALS MAY
END WITH A MIX OF RAIN/SLEET/SNOW...BUT THE DURATION OF ANY MIXED
PRECIP IS EXPECTED TO BE VERY BRIEF.
FLURRIES ALSO POSSIBLE AT TIMES THIS AFTERNOON...BUT NOT ENOUGH
CONFIDENCE IN PLACEMENT AND OCCURRENCE TO INCLUDE IN TAFS.
THE STRONG WINDS WILL PERSIST THROUGH AT LEAST 00Z.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KEWR FCSTER COMMENTS: OCCASIONAL GUSTS AROUND 40 KTS POSSIBLE
THROUGH THE REST OF THE MORNING...AND UP TO 41-44 KTS POSSIBLE
THIS AFTERNOON.
KJFK FCSTER COMMENTS: OCCASIONAL GUSTS UP TO 45 KTS POSSIBLE FOR
THE REST OF THIS MORNING...AND UP TO 45-48 KTS POSSIBLE THIS
AFTERNOON.
KLGA FCSTER COMMENTS: OCCASIONAL GUSTS AROUND 40 KTS POSSIBLE
THROUGH THE REST OF THE MORNING...AND UP TO 43-46 KTS POSSIBLE
THIS AFTERNOON.
KTEB FCSTER COMMENTS: OCCASIONAL GUSTS 35-38 KTS POSSIBLE THROUGH THE
REST OF THE MORNING
KHPN FCSTER COMMENTS: GUSTS MIGHT NOT REACH 40 KT THIS AFTERNOON.
KISP FCSTER COMMENTS: OCCASIONAL GUSTS 35-38 KTS POSSIBLE
THROUGH THE REST OF THE MORNING...AND UP TO 40-43 KTS POSSIBLE
THIS AFTERNOON.
OUTLOOK FOR 12Z SATURDAY THROUGH TUESDAY...
SAT...VFR. FLURRIES POSSIBLE. GUSTY NW-W WINDS.
SUN-MON...VFR.
TUE...SUB VFR POSSIBLE IN RAIN/MORNING WINTRY PRECIP.
&&
.MARINE...
GUSTS TO GALE FORCE BEHIND THE EXITING COLD FRONT EXPECTED INTO THIS
EVENING...THOUGH NOT NECESSARILY ALL THE TIME. WILL CONTINUE WITH
GALE WARNING AS AS...WITH GALE WARNING THROUGH THE OVERNIGHT HOURS
ACROSS THE OCEAN WATERS EAST OF FIRE ISLAND INLET.
ONCE THE WINDS DIMINISH ON THE REMAINDER OF THE FORECAST WATERS
THIS EVENING...SMALL CRAFT WIND GUSTS WILL CONTINUE THROUGH MUCH OF
THE OVERNIGHT. AND SMALL CRAFT WINDS WILL BE LIKELY ON THE OCEAN
WATERS INTO SATURDAY AFTERNOON...WITH SEAS REMAINING ABOVE 5 FT INTO
SATURDAY NIGHT.
STRONG OFF SHORE FLOW THROUGH TODAY WILL PUSH WATER OUT OF THE
WESTERN LONG ISLAND SOUND. THIS WILL RESULT IN LOW WATER PROBLEMS
DURING LOW TIDE THIS EVENING AND A LOW WATER ADVISORY HAS BEEN
ISSUED.
MARGINAL SCA WIND GUSTS REMAINING ON THE OUTER OCEAN WATERS THROUGH
SAT NIGHT BEFORE ENDING SUN MORNING. SUB SCA CONDITIONS THEN
EXPECTED THROUGH MON. MON NIGHT...OUT AHEAD OF NEXT COLD
FRONT...SOUTHERLY FLOW WILL LEAD TO A RETURN OF WIND GUSTS AND SEAS
TO SCA LEVELS WHICH COULD VERY WELL CONTINUE THROUGH THE REMAINDER
OF THE FORECAST.
&&
.HYDROLOGY...
AROUND A TENTH OF AN INCH OF RAINFALL IS POSSIBLE THROUGH EARLY THIS
AFTERNOON. DRY WEATHER RETURNS TONIGHT AND CONTINUES THROUGH MONDAY.
&&
.TIDES/COASTAL FLOODING...
STRONG AND GUSTY SOUTHWESTERLY WINDS DEVELOPING THIS MORNING AND
CONTINUING THROUGH THE DAY WILL PUSH WATER OUT OF THE WESTERN LONG
ISLAND SOUND. BY THE TIME OF THE LOW TIDE EARLY THIS EVENING TIDAL
DEPARTURES ARE EXPECTED TO RUN 3 TO 3 1/2 FT BELOW NORMAL. THIS
WILL RESULT IN LOW WATER PROBLEMS AND A LOW WATER ADVISORY HAS
BEEN ISSUED.
LATEST TRENDS IN OBSERVATIONS BEGINNING TO GIVE CONCERN ABOUT LOW
WATER IN NEW YORK HARBOR AND THE SOUTH SHORE BAYS AS WELL FOR
SATURDAY MORNINGS LOW TIDE. WILL CONTINUE TO EVALUATE.
&&
.EQUIPMENT...
THE KOKX WSR-88D WILL BE DOWN FOR THE INSTALLATION OF DUAL
POLARIZATION SOFTWARE AND HARDWARE THROUGH JANUARY 24TH.
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...WIND ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR CTZ005>012.
NY...WIND ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR NYZ067>075-
078>081-176>179.
NJ...WIND ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR NJZ002-004-006-
103>108.
MARINE...GALE WARNING UNTIL MIDNIGHT EST TONIGHT FOR ANZ330-335-338-340-
345-355.
LOW WATER ADVISORY FROM 6 PM TO 11 PM EST THIS EVENING FOR
ANZ335.
GALE WARNING UNTIL 5 AM EST SATURDAY FOR ANZ350-353.
&&
$$
SYNOPSIS...MALOIT/MET
NEAR TERM...MALOIT
SHORT TERM...MET
LONG TERM...JM
AVIATION...JMC
MARINE...MALOIT/JM/MET
HYDROLOGY...MET
TIDES/COASTAL FLOODING...MET/MALOIT
EQUIPMENT...MALOIT
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1219 PM EST FRI JAN 13 2012
.AVIATION... / 18Z TAFS /
TRANSITION TO PURE LAKE EFFECT SNOW SHOWERS TAKING PLACE WITH
PRIMARY IMPACT ANTICIPATED THIS AFTERNOON AND EVENING AT SBN. AS
IS THE NATURE WITH LAKE EFFECT VISIBILITIES OFTEN BOUNCE BACK AND
FORTH BETWEEN LIFR/IFR/MVFR AND EXPECT THIS AT SBN THIS AFTN/EVE.
MAINLY MVFR CIGS THROUGH THE PERIOD AT FWA WITH SCT SNOW SHOWERS
POSSIBLY REDUCING VISBY`S AT TIMES THIS AFTN. A GRADUAL
IMPROVEMENT TO HIGHER END MVFR CIGS CAN BE EXPECTED LATE TONIGHT
INTO TOMORROW MORNING AS THE FLOW BACKS AND LE SHSN`S SHIFT NORTH
OF THE TERMINALS. OTHERWISE...GUSTY WESTERLY WINDS WILL FINALLY
BEGIN TO RELAX BY EARLY THIS EVENING.
&&
.PREV DISCUSSION... /ISSUED 414 AM EST FRI JAN 13 2012/
SHORT TERM...
MID LVL DEFORMATION ZONE CONTS TO PIVOT EWD ACRS CWA THIS MORNING IN
RESPONSE TO UPR LOW LIFTING OUT OF ERN OH. BROAD/DEEP MSTR PLUME
REMAINS ENTRENCHED UPSTREAM WITHIN DEEP CYCLONIC FLW OVR THE WRN
LAKES AND WHICH PRESENTS SOMEWHAT OF A PROBLEM GOING FORWARD THROUGH
THIS MORNING. SNOWFALL ACCUMS SO FAR RANGE FM 3-4 INCHES NORTHWEST
TO LESS THAN 1 INCH ERN HALF THANKS SOLELY TO MID LVL DRY SLOT THAT
WRAPPED IN ALG ERN SIDE OF CLOSING MID LVL CIRC YDA. HWVR SFC TROUGH
HAS PIVOTED INLAND ACRS BERRIEN/LAPORTE COUNTIES AS OF 09Z AND
RESULTED IN A SEQUENTIAL BLOSSOMING IN HIGHER RADAR RTNS OF
25-30 DBZ INDICATING WIDESPREAD MOD-HVY SNOW ONGOING NOW GENERALLY
ALG A LINE FM KIRS...KASW...KRCR. XPC FURTHER CONSOLIDATION
/DEFINITION TO LK BANDS BTWN NOW AND 15Z AS LL WIND FIELD BECOMES
BTR DEFINED AND OBSVD IN RECENT RADAR TRENDS. IN ADDN...INLAND THERMAL
MODIFICATION HAS BEEN QUITE ROBUST W/5-10 DEGREES WARMING NOTED
OVERNIGHT AND SHLD CONT TO PROMOTE INTENSE LL FRONTOGENESIS ESP INLAND
THROUGH THIS AFTN AND THEREIN LIES THE BIGGEST PROBLEM. MIX OF
00Z-06Z HIGHRES GUIDANCE WAVERS CONSIDERABLY ON PLACEMENT OF SRN
EDGE OF LK ENHANCEMENT THIS MORNING BFR GIVING AWAY TO PURE LK
EFFECT BY THIS AFTN W/AN IMPLIED ADDNL 3-4 INCHES OF SNOW FM
12-00Z. PRIOR 00-03Z RUC FCST TREND LOOKED CLOSE UPSTREAM YET WAS
TOO FAR EAST W/ALIGNMENT AT 06Z AND TOO PROGRESSIVE. HWVR 06Z FCST
OFF EVEN FURTHER. NAM12 LIES MIDWAY BTWN NMM/ARW SOLUTIONS SO A
COMBO OF THOSE THREE SHLD SUFFICE THROUGH AFTN BFR SWITCHING TO
BLENDED HIGHRES PLACEMENT. THUS NRN 2 TIERS OF WARNING WILL CONT
THROUGH 00Z W/LIKELY EXTENSION NEEDED THIS EVENING PENDING PRIMARY
LK BAND EVOLUTION THROUGH THIS MORNING. THIS REMAINS QUITE
UNCERTAIN...AND TIED TO WHETHER ERN BAND THROUGH CASS/ST
JOE/LAGRANGE OR WRN BAND THROUGH LAPORTE/ST JOE/ELKHART DOMINATES
AND LTL DEFINITIVE SIGNAL SEEN YET IN OBSVNL TRENDS THIS MORNING
TO GIVE A NOD ONE WAY OR THE OTHER.
AS FOR HIGHLIGHTS...SRN WARNING SEGMENT CONSISTING OF
STARKE/MARSHALL/KOSCIUSKO WILL BE DOWNGRADED. WILL HOLD
W/ADVISORY AREA AS LARGER AREA OF SYNOPTICALLY ENHANCED SHSN
WORKS THROUGH THE AREA THIS MORNING W/GENERAL 1-2 INCHES ADDNL
XPCD THROUGH 18Z. HWVR SW ZONES WILL LIKELY BE DROPPED AT SOME
POINT PRIOR TO EXPIRATION.
PRIMARY LK BAND THROUGH SW MI INTO NRN IN PROGGED TO REMAIN QUITE
INTENSE INTO THIS EVENING AND WILL LIKELY ADD ANOTHER 1-3 INCHES
HWVR ERODING INVERSION HGTS AND GENERAL DRYING ALOFT SUGGEST
INTENSITY WILL BE LIMITED W/GREATER ACCUMS CONFINED TO
LAPORTE/BERRIEN AND CASS. OTHERWISE SFC GRADIENT WKNS RAPIDLY LT
THIS AFTN W/BLSN ENDING.
UPSTREAM CLIPPER PUSHING THROUGH WRN ALBERTA THIS MORNING WILL DIVE
QUICKLY SEWD TONIGHT AND INTO THE OH VALLEY SAT AFTN. CERTAINLY A
LACK OF MSTR OVERTOP RETREATING ARCTIC WEDGE HWVR GOING GRIDDED POPS
LOOK REASONABLE AND MAINTAINED. PRIMARY CHG WAS TO BLEND TWD COLDER
MOS SPLIT ON MAX TEMPS.
LONG TERM.../SUNDAY THROUGH THURSDAY/
UPPER LEVEL FLOW WILL AMPLIFY SOMEWHAT FOR THE START OF THE NEW
WEEK. THIS WILL ALLOW FOR MODERATING TEMPERATURES BACK TO NEAR OR
ABOVE NORMAL LEVELS BEFORE THE NEXT TROUGH BRINGS PRECIP AND COLDER
WEATHER BACK TO THE AREA.
RAPID WAA WILL BE UNDERWAY DURING THE DAY SUNDAY AS 850 MB TEMPS
CLIMB A GOOD 5 TO 10 DEGREES C REACHING TO +2 TO -3 C BY SUNDAY
EVENING. EVEN WARMER TEMPS WILL BE ADVECTED IN SUNDAY NIGHT INTO
MONDAY AS LL FLOW RAMPS UP ALLOWING FOR MOST AREAS TO +3 TO +6 C IN
THE LOW LEVELS BY MONDAY EVENING. CONCERNS FOR SEEING THESE WARMER
TEMPS AT THE SURFACE REMAIN AS A RESULT OF COMBINATION OF AT LEAST
SOME SNOWPACK /ALTHOUGH MAYBE NOT AS MUCH AS ORIGINALLY THOUGHT/ AND
INCREASING CLOUD COVER ASSOCIATED WITH THE APPROACHING SYSTEM. HAVE
OPTED TO HAVE FEW CHANGES TO TEMPS SUNDAY AND MONDAY FOR THE TIME
BEING. LIGHT PRECIP IS STILL POSSIBLE AS LL MSTR WILL INCREASE AND
AT LEAST SOME LOW LEVEL LIFT WILL TAKE PLACE. IF PRECIP WAS TO
ARRIVE FAST ENOUGH MONDAY MORNING...THERE COULD BE A PERIOD OF
FREEZING PRECIP...BUT TEMPS SHOULD CLIMB FAIRLY QUICK ABOVE FREEZING
AND KEEP THIS THREAT TO A MINIMUM.
BEST CHANCE FOR RAINFALL WILL BE MONDAY NIGHT AS COLD FRONT
APPROACHES THE AREA WITH LOW PRESSURE TRACKING ALONG IT. CONFIDENCE
IN ANY ONE MODEL SOLUTION NOT VERY HIGH WITH NORMALLY FAVORED ECMWF
FLIP FLOPPING BETWEEN NORTHERN ENERGY REMAINING STRONGER WITH SFC
LOW ACROSS NORTHERN GREAT LAKES...AND SOUTHERN ENERGY STRENGTHENING
ALLOWING FOR DEEPENING LOW PRESSURE OVER THE FORECAST AREA ON
TUESDAY. WILL MAINTAIN LIKELY POPS MONDAY NIGHT AND HIGHER END POPS
CHC TO LOW END LIKELY TUESDAY FOR CONSISTENCY SAKE. PTYPE SHOULD BE
ALL RAIN MONDAY NIGHT BUT COULD BE RAIN OR MIX OF RAIN/SNOW ON
TUESDAY DEPENDING ON TRACK OF SFC LOW. RUSH OF COLD AIR WILL ARRIVE
ONCE AGAIN WITH TEMPS FALLING BACK BELOW NORMAL INTO THE 20S AND
REMAINING THAT WAY THROUGH THE REMAINDER OF THE PERIOD. YET ANOTHER
DISTURBANCE WILL ARRIVE FOR WEDS NGT INTO THURS BRINGING ANOTHER
CHANCE FOR SNOW.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WARNING UNTIL 7 AM EST /6 AM CST/ SATURDAY FOR
INZ003>006-008.
WINTER WEATHER ADVISORY UNTIL 1 AM EST SATURDAY FOR INZ007-009.
MI...WINTER STORM WARNING UNTIL 7 AM EST SATURDAY FOR MIZ077>080.
WINTER WEATHER ADVISORY UNTIL 1 AM EST SATURDAY FOR MIZ081.
OH...NONE.
LM...GALE WARNING UNTIL 7 PM EST THIS EVENING FOR LMZ043-046.
&&
$$
SHORT TERM...T
LONG TERM...FISHER
AVIATION...STEINWEDEL
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
327 PM CST FRI JAN 13 2012
.SYNOPSIS...
12Z UA ANALYSIS HAS AN EXTRATROPICAL CYCLONE IN SOUTHEAST CANADA
WITH NUMEROUS TROFS FROM THE TENNESSEE VALLEY BACK INTO THE UPPER
MIDWEST. RADAR TRENDS THROUGH MID AFTERNOON CONTINUE TO SHOW PLENTY
OF FLURRIES AND LIGHT SNOW OVER THE MID MISSISSIPPI VALLEY. CLEARING
UNDER THE CYCLONIC FLOW WAS MAKING SLOW BUT STEADY PROGRESS EASTWARD.
18Z SFC ANALYSIS HAS A COLD FRONT FROM THE EASTERN GREAT LAKES BACK
INTO NORTHEAST ILLINOIS WITH A HIGH PRESSURE RIDGE FROM MINNESOTA
INTO EASTERN TEXAS. A CHINOOK WARM FRONT WAS OVER THE EASTERN PARTS
OF THE DAKOTAS AND NEBRASKA. A WARM FRONT ASSOCIATED WITH THE NEXT
CLIPPER SYSTEM WAS MOVING OUT OF THE NORTHERN ROCKIES. DEW POINTS
UNDER THE HIGH PRESSURE RIDGE WERE IN THE SINGLE DIGITS ABOVE AND
BELOW ZERO. OTHERWISE DEW POINTS WERE IN THE TEENS AND 20S ACROSS
THE MIDWEST AND PLAINS.
&&
.SHORT TERM...TONIGHT AND SATURDAY...
LIGHT SNOW WILL CONTINUE THROUGH LATE AFTERNOON BUT WILL TAPER TO
FLURRIES ONCE SUNSET OCCURS. RUC TRENDS CONTINUE TO SHOW WEAK F
VECTOR CONVERGENCE AND WEAK FRONTOGENETICAL FORCING WILL REMAIN
ACROSS THE AREA INTO THE EARLY EVENING. THAT COMBINED WITH THE
SHALLOW ARCTIC AIR MASS AND A VORT MAX MOVING THROUGH THE CWFA WILL
ALLOW FLURRIES TO PERSIST THROUGH MID EVENING.
CLEARING WILL OCCUR FROM WEST TO EAST DURING THE EVENING AND
OVERNIGHT HOURS. TEMPERATURES SHOULD DROP QUICKLY ONCE CLEARING
OCCURS DUE TO THE SNOW COVER AND LIGHT WINDS. AFTER MIDNIGHT...WAA
CLOUDS FROM THE APPROACHING CLIPPER SYSTEM WILL MOVE INTO THE AREA
AND LIKELY ALLOW TEMPERATURES TO BOTTOM OUT AND SLOWLY RISE.
AFTER 3 AM...ALL MODELS SHOW F VECTOR CONVERGENCE DEVELOPING AGAIN
WITH COLLAPSING CONDENSATION PRESSURE DEFICITS ALONG WITH AN
INCREASE IN FRONTOGENETICAL FORCING. MOISTURE WITH THIS CLIPPER
SYSTEM IS LIMITED BUT FLURRIES AND LIGHT SNOW SHOULD BREAK OUT PRIOR
TO DAWN GENERALLY WEST OF A KIIB TO KPPQ LINE. SCHC/CHC POPS WERE
DONE DUE TO THE LIMITED MOISTURE BUT MAY NEED TO BE RAISED IN THE
EXTREME WEST AND SOUTHWEST PARTS OF THE CWFA.
THE WAA PRECIPITATION WING OF THE CLIPPER SYSTEM WILL MOVE ACROSS
THE WESTERN HALF OR TWO THIRDS OF THE CWFA SATURDAY MORNING.
CONDENSATION PRESSURE DEFICITS REMAIN LOW AND THERE IS F VECTOR
CONVERGENCE WITH SOME FORCING. DURING THE AFTERNOON THE COLD
CONVEYOR BELT PRECIPITATION FROM THE CLIPPER SYSTEM WILL OVERSPREAD
THE ENTIRE AREA BEFORE ENDING FROM THE WEST LATE IN THE AFTERNOON.
AS FOR AMOUNTS...A DUSTING OF ACCUMULATION IS POSSIBLE PRIOR TO
SUNRISE IN THE FAR WEST/SOUTHWEST PARTS OF THE CWFA. ACCUMULATIONS
DURING THE DAY SATURDAY SHOULD RANGE FROM A DUSTING TO ONE HALF
INCH. IT IS CONCEIVABLE THAT ACCUMULATIONS APPROACHING AN INCH MAY
OCCUR OVER THE SOUTHWEST THIRD TO HALF OF THE CWFA. ..08..
.LONG TERM...SATURDAY NIGHT THROUGH NEXT FRIDAY...
ACTIVE/UNSETTLED PATTERN TO PERSIST THROUGH THE PERIOD WITH MANY FCST
CHALLENGES. MAIN STORM SYSTEM THAT BEARS CONSIDERABLE WATCHING IS IN
MON-TUE TIME-FRAME. THIS STORM LOOKS TO BRING WINTRY MIX OF PCPN WITH
POTENTIAL FOR HEADLINES.
SAT NGT... SOME RESIDUAL WEAK LIFT LINGERS INTO THE EVE ACROSS THE NORTH
AS CLIPPER DEPARTS AND WARM FRONT PUSHES THROUGH. NAM AND GFS
BUFR SOUNDINGS SHOW LOSS OF ICE INTRODUCTION WHICH WOULD SUPPORT DRIZZLE
OR FREEZING DRIZZLE. CONCERNS THOUGH THESE MODELS MAY BE OVERDONE WITH
EXTENT OF LOW LEVEL MOISTURE ... A TYPICAL BIAS ESPECIALLY WITH
NAM... ESPECIALLY GIVEN NO SNOW MELT. GIVEN UNCERTAINTIES AND WITH
ANY PCPN JUST TRACE AMOUNTS HAVE LEFT OUT ANY MENTION ATTIM. MAY SEE
TEMPS STEADY OR RISING OVRNGT ESPECIALLY SOUTH WITH ONSET OF LOW LEVEL
WARM ADVECTION.
SUN-SUN NGT... NEXT ARCTIC FRONT TO EMERGE INTO THE PLAINS AND EXPECTED
TO PUSH THROUGH IA AND POSSIBLY BISECTING 12Z MON PER NAM/GFS. HI-RES
ECMWF SLOWER BUT 12Z RUN IS SLIGHTLY FASTER AND MAY BE TRENDING TOWARD
NAM/GFS. DEEPER MOISTURE RETURNS LATE FOR POSSIBLY SOME VERY LIGHT RAIN
OR DRIZZLE AFTER MIDNIGHT... OR VERY LIGHT FREEZING RAIN/DRIZZLE IN SOME
AREAS DEPENDING ON SFC TEMPS WITH NW CWA MOST SUSCEPTIBLE IT APPEARS
ATTIM BUT THIS DEPENDENT ON FRONTAL TIMING. MOST IF NOT ALL OF
AREA SHOULD GET ABOVE FREEZING WITH 40S WIDESPREAD ACROSS THE SW CWA ON
GUSTY SOUTHERLY WINDS.
MON-TUE... STRONG BAROCLINICITY AND COUPLED JET STRUCTURE SUPPORT
CYCLOGENESIS ALONG ARCTIC FRONT... WITH CONSIDERABLE MODEL SPREAD ON
MAGNITUDE/TRACK/TIMING... AND GIVEN HIGHLY DYNAMICAL ENVIRONMENT EXPECT
CONTINUED CHANGES IN MODELS NEXT DAY OR TWO. GFS AND HI-RES ECMWF HAVE
TRENDED DEEPER AND SLOWER... AND MAY CONTINUE TO SEE THIS TREND. BOTTOM
LINE IS MOISTURE AND FORCING SUPPORTS MODERATE QPF EVENT NOT TOO
DISSIMILAR FROM THIS MOST RECENT EVENT. DEPENDING ON FRONT AND SFC LOW
LOCATIONS PCPN TYPES COULD VARY OR TRANSITION FROM RAIN TO FREEZING
RAIN...SLEET AND SNOW ACROSS CWA. THEREFORE... WITH THE WINTRY MIXTURE
THIS SYSTEM WILL BEAR CONSIDERABLE WATCHING IN THE DAYS AHEAD. POPS ARE
IN MOD/HIGH CHC CATEGORY FOR NOW GIVEN UNCERTAINTY WITH TRACK. IN
ADDITION MAY SEE FOG MON WITH AREAS OF DENSE FOG AHEAD OF SFC LOW WITHIN
LOW LEVEL MOISTURE CONVERGENCE.
WED-FRI... MUCH COLDER WITH ANOTHER ARCTIC FRONT SUGGESTED TO ARRIVE
WED THAT MAY NEED POPS IN LATER FCSTS. FOR NOW THOUGH HAVE CHC POPS
THU-FRI AS ENERGY RIPPLES ALONG LOW-MID LEVEL BAROCLINIC ZONE. WINTER HAS
FINALLY ARRIVED. ..05..
&&
.AVIATION...
MVFR CONDITIONS WILL CONTINUE THROUGH 03Z/14 WITH -SN. THE -SN IS
EXPECTED TO TAPER TO FLURRIES WITH SUNSET. VFR WX WILL THEN BE SEEN
AS HIGH PRESSURE MOVES ACRS EASTERN IOWA AND ILLINOIS. THE NEXT
SYSTEM APPROACHES FROM THE NORTHERN PLAINS AFT 06Z/14 WITH -SN
EXPECTED TO DVLP JUST PRIOR TO SUNRISE AT KCID/KBRL. 12Z-18Z/14 MVFR
CONDITIONS WILL AGAIN DVLP AT ALL TAF SITES AS -SN BECOMES MORE
WIDESPREAD. ..08..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1126 AM CST FRI JAN 13 2012
.AVIATION...
MVFR CONDITIONS WILL CONTINUE THROUGH 00Z/14 WITH -SN. AFT 00Z/14
VFR CONDITIONS WILL DVLP AT ALL TAF SITES WITH LIGHT WINDS. NEXT
SYSTEM APPROACHES FROM THE NORTHERN PLAINS WITH -SN DVLPG JUST
PRIOR TO SUNRISE AT KCID/KBRL. AFT 12Z/14 MVFR CONDITIONS WILL
AGAIN DVLP AT ALL TAF SITES WITH -SN BECOMING MORE WIDESPREAD.
..08..
&&
.PREV DISCUSSION... /ISSUED 1000 AM CST FRI JAN 13 2012/
UPDATE...
A SIGNIFICANT REVISION IS COMING TO THE OVERALL FCST. WATER VAPOR
SHOWS A NICE VORT MAX ROTATING SOUTHEAST ACROSS IOWA. RADAR
RETURNS ARE EXPANDING ACROSS THE AREA SHOWING -SN DEVELOPING PER
SFC OBS. A DUSTING HAS ALREADY OCCURRED IN THE CID METRO AREA.
PER THE RUC TRENDS...THERE IS WEAK F VECTOR CONVERGENCE ACROSS THE
AREA THAT MAINTAINS THROUGH THE AFTERNOON. FORCING IS WEAK BUT
THERE AND CONDENSATION PRESSURE DEFICITS ARE MODERATELY LOW IN THE
SHALLOW ARCTIC AIR.
BASED ON THIS THE FCST HAS BEEN REVISED TO GO WITH -SN FOR THE
REMAINDER OF THE DAY. ACCUMULATIONS SHOULD ONLY BE A DUSTING BUT
EMBEDDED SNOW SHOWERS MAY RESULT IN LOCALIZED HALF INCH ACCUMULATIONS.
AN UPDATED FCST WILL BE AVAILABLE SHORTLY.
.08..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
208 PM MST FRI JAN 13 2012
.SYNOPSIS...
208 PM MST FRI JAN 13 2012
EARLY AFTERNOON WV IMAGERY AND RUC H5 ANALYSIS SHOW LARGE SCALE
PATTERN DOMINATED BY TROUGH ACROSS THE EASTERN CONUS...WITH RIDGE
BUILDING ALONG THE PACIFIC COAST. WEDGED BETWEEN THESE TWO
FEATURES...N/NW FLOW CONTINUES ACROSS THE CWA.
DR
&&
.DISCUSSION...
208 PM MST FRI JAN 13 2012
TONIGHT...SHOULD SEE NORTHWEST WINDS OF 10 TO 20 MPH WINDS WITH
HIGHER GUSTS THROUGH MIDNIGHT BEHIND A DEPARTING UPPER LEVEL
DISTURBANCE. AFTER MIDNIGHT WINDS SUBSIDE A BIT INTO THE 10 MPH
RANGE. OVERNIGHT LOWS WILL BE A BIT WARMER THEN THE PAST FEW NIGHTS
AS WARM AIR ALOFT MOVES IN. WILL AIM FOR LOWS GENERALLY IN THE UPPER
TEENS TO LOW 20S IN FAR EASTERN COLORADO...LOW TO MID 20S EAST OF
THE CO/KS BORDER. THIS IS SEVERAL DEGREES WARMER THAN THE MAV AND
MET MOS GUIDANCE.
007
SATURDAY-SUNDAY...H5 RIDGE CONTINUES TO BUILD EAST TOWARDS CWA...WITH
DRY/STABLE AIR MASS IN PLACE THROUGH SUNDAY NIGHT. TEMPERATURES
WILL CONTINUE TO MODERATE OVER THE NEXT FEW DAYS...WITH HIGH TEMPS
IN THE 50S SATURDAY...AND MID/UPPER 50S ON SUNDAY. CONSIDERING
TEMPS ALOFT SAT/SUN NIGHTS...BUMPED LOWS TO THE UPPER 20S. THIS IS
ABOUT 5-10F ABOVE MOS GUIDANCE...HOWEVER CONSIDERING TEMPS ALOFT
AND POSSIBLE SKY COVER SUN NIGHT...THIS MAY STILL BE TOO COOL.
MONDAY-MONDAY NIGHT...TROUGH DEVELOPING OVER THE PACIFIC NW OVER THE
WEEKEND WILL PROGRESS EAST ACROSS THE GREAT BASIN TOWARDS THE CWA
MONDAY. GUIDANCE STILL DIFFERS BY ABOUT 6HR ON TIMING OF ASSOCIATED
COLD FRONT MONDAY...HOWEVER OVERALL TREND HAS BEEN TO SPEED UP
ARRIVAL...WITH FRONTAL PASSAGE LIKELY BY MIDDAY. PRECIP ASSOCIATED WITH
LARGE SCALE ASCENT ALONG LEADING EDGE OF TROUGH AXIS LOOKS TO ARRIVE
FROM THE NW LATE MONDAY AFTERNOON...QUICKLY MOVING EAST THROUGH THE
EVENING HOURS. GUIDANCE IN GOOD AGREEMENT ON STABLE/DRY AIR QUICKLY
MOVING IN AFTER 06Z...SO I TRENDED FORECAST IN THAT DIRECTION. I
KEPT BEST CHANCES DURING THE EVENING IN THE NORTH...AND LEFT A SMALL
AREA OF SLIGHT CHANCE POPS IN THE FAR EAST AFTER 06Z. CONSIDERING
LIMITED MOISTURE AND QUICK NATURE OF THIS SYSTEM...ONLY ANTICIPATING
LIGHT SNOW ACCUMULATIONS...ABOUT AN INCH OR LESS.
TUESDAY-FRIDAY...REMAINING FORECAST LOOKS DRY WITH W/NW FLOW
DEVELOPING ACROSS WESTERN CONUS...AND DRY/STABLE AIR MASS IN PLACE.
BIGGEST QUESTION THROUGH THESE PERIODS WILL BE HOW QUICKLY SHALLOW
COLD AIR MASS MODERATES...AND WHAT TEMPS WILL DO IN RESPONSE TO WEAK
SHORTWAVE TROUGHS EMBEDDED WITHIN MEAN FLOW. FOR NOW EXPECT BELOW
NORMAL TEMPS TUESDAY AND NEAR NORMAL TEMPS WEDNESDAY. GUIDANCE STILL
INDICATING RISING H5 HEIGHTS H85 TEMPS TO ABOUT 10-12C BY
FRIDAY...WHEN I KEPT FORECAST OF MID 50S IN THE WEST. THIS MAY END
UP BEING TOO COOL CONSIDERING CONDITIONS ALOFT...HOWEVER THERE IS
ENOUGH UNCERTAINTY IN REGARDS TO BOUNDARY LAYER DIFFERENCES TO
KEEP ME FROM CHANGING TOO MUCH THIS FAR OUT.
DR
&&
.AVIATION...
1020 AM MST FRI JAN 13 2012
FOR THE 18Z TAFS...VFR CONDITIONS WILL CONTINUE THROUGH THE
PREVAILING PERIOD. LIGHT WINDS ARE EXPECTED TO BECOME GUSTY AFTER
19Z...HOWEVER...MODELS DIFFER IN INTENSITY. HAVE GONE MID RANGE
FOR WIND AND GUSTS...WILL MONITOR AND ADJUST IF NECESSARY. SURFACE
TROUGH WILL CONTINUE TO MOVE THROUGH THE AREA THIS AFTERNOON WITH
WINDS BECOMING LIGHT OVERNIGHT AND TOMORROW. A FEW MID LEVEL CLOUDS
WILL BE POSSIBLE AS THE UPPER LEVEL SYSTEM MOVES ACROSS THE
NORTHERN PLAINS.
PMM
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
NE...NONE.
CO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAY ME
1256 PM EST FRI JAN 13 2012
.SYNOPSIS...
LOW PRESSURE WILL MOVE EAST FROM THE GREAT LAKES AND DOWN THE
SAINT LAWRENCE RIVER VALLEY DRAGGING A COLD FRONT ACROSS THE
REGION THIS AFTERNOON. A SECOND COLD FRONT WILL MOVE THROUGH LATE
TONIGHT OR EARLY SATURDAY. ARCTIC HIGH PRESSURE WILL BUILD EAST
ACROSS THE REGION SATURDAY NIGHT THROUGH MONDAY. A COLD FRONT WILL
APPROACH FROM THE MIDWEST MONDAY NIGHT AND TUESDAY THEN EXIT THE
COAST EARLY WEDNESDAY. A RIDGE OF HIGH PRESSURE FOLLOWS FOR
WEDNESDAY. A WEAK CLIPPER SYSTEM WILL CROSS THE AREA LATE NEXT
WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
1753Z UPDATE...
MORE ADVISORIES FOR FREEZING RAIN ARE SET TO EXPIRE OVER THE NEXT
HOUR. ATMOSPHERE WILL QUICKLY TRANSITION BEHIND THE STRONG FRONT.
DESPITE THE STRONG CAA...TEMPS MAY BRIEFLY JUMP UPWARDS INTO THE
30S IN MANY AREAS.
STRONG GUSTY WINDS AND ISOLD SQUALLS MAY OCCUR THROUGH THIS
EVENING...ESPECIALLY ACROSS THE HIGHER TERRAIN. HIGHEST WIND GUSTS
THIS AFTERNOON WILL BE OVER THE HILLTOWNS OF
MERRIMACK...ROCKINGHAM AND STRAFFORD COUNTIES...FOLLOWED BY GUSTY
WINDS ALL AREAS THIS EVENING.
1400Z UPDATE...
HAVE TAKEN A VERY CLOSE LOOK AT WIND FIELDS THIS MORNING AND USED
NEW MIXING TECHNIQUES IN THE GRIDS INVOLVING MIXING HEIGHT AND
WIND FIELDS FROM SEVERAL MODELS INCLUDING THE HRRR AND RUC. EXPECT
WIND GUSTS IN THE 35 TO 40 MPH RANGE OVER SOUTHERN NEW HAMPSHIRE
AND FAR SOUTHWEST MAINE TO DEVELOP DURING THE AFTERNOON HOURS.
WITH A FRESH GLAZE OF ICE ON THE TREES FROM THIS MORNINGS FREEZING
RAIN AND FREEZING DRIZZLE...EXPECT SOME TREE LIMBS TO BE DOWNED.
HAVE COORDINATED WITH NH ON THIS...AND HAVE CALLED OBSERVERS IN
THE AREA...WHICH SUGGESTS ABOUT A TENTH TO TWO TENTHS OF AN INCH
OF ICE HAS ACCUMULATED ON TREES. THE RESULT...WITH THE APPROACHING
WIND AND THE CURRENT ICING WILL BE SCATTERED POWER OUTAGES. WILL
CONTINUE TO MONITOR THIS CLOSELY AND WILL BE ISSUING AN SPS IN THE
NEXT HOUR FOR THIS POTENTIAL.
MINOR EDITS TO THE REST OF THE GRIDS...HOWEVER...HAVE LOWERED THE
MAX TEMPS DOWN A BIT. THIS HAS A BIG IMPACT ON THE MIXES LEVELS
THIS AFTERNOON. EXPECT TEMPS TO JUMP FOR ABOUT AN HOUR (UPWARDS)
AFTER THE FROPA...THEN HEAD RIGHT BACK DOWN.
WITH THE APPROACH OF THE OCCLUSION...FREEZING DRIZZLE AND FREEZING
RAIN SHOULD BE ENDING SHORTLY IN PORTIONS OF NH. HAVE ALLOWED SOME
OF THE ADVISORIES TO EXPIRE.
PREV DISC...
WILL UPDATE TO INPUT LATEST OBSERVED DATA. NO REAL CHANGES AT
THIS TIME. THE UPR LVL TROF AND SFC LOW ARE EXITING INTO THE
MARITIMES EARLY THIS MORNING WITH NORTHERLY WINDS IN ITS WAKE KEEP
TEMPS BELOW FREEZING JUST ABOUT EVERYWHERE ACROSS THE FCST AREA.
THE ONLY PLACES THAT MAY STILL BE AROUND FREEZING ARE ALONG THE
IMMEDIATE COASTLINE OVER THE MID COAST REGION OF MAINE.
A MUCH LARGER UPR LVL CUTOFF SYSTEM TO OUR SW WILL LIFT OUT TO
THE NE AND WEAKEN TDA AS IT FORCES A SFC LOW TO TRACK FROM THE ERN
GREAT LAKES DOWN THE ST LAWRENCE RIVER VALLEY TDA. A TRAILING CD
FNT WILL SWEEP FROM SW TO NE ACROSS THE FCST AREA LATE THIS
MORNING INTO THIS AFTERNOON. AHEAD OF THIS FNT CD AIR REMAINS AT
THE SFC WHILE WARMER AIR CONTINUES TO MOVE IN ALOFT. AN AREA OF
PRCP MOVES IN WITH THE UPR LVL AND SFC SYSTEMS...AND IS ALREADY
SHOWING UP ON THE RADAR MOSAIC LOOP WITH PRCP POISED TO MOVE INTO
OUR MOST SW ZONES AT THIS TIME.
PRCP WILL BE MOSTLY LGT FZRA THOUGH SOME IP OR EVEN SOME WET SN
PSBL ACROSS THE MORE NRN ZONES. COULD SEE SOME -RA ALONG THE MID
COAST REGION. WITH ACCUMULATING FZRA THRU THE MORNING AND INTO THE
AFTERNOON OVER MORE NRN AND ERN ZONES WILL CONT A FREEZING RAIN
ADVISORY. THERE COULD BE OTHER PRCP TYPES WITH THIS EVENT...
ESPECIALLY ACROSS THE N/MT ZONES BUT THE MAIN THREAT WILL BE FZRA
AND WANT TO HIGHLIGHT THAT.
AS THE FNT MOVES THRU GUSTY SW WINDS SET UP WHICH MIX OUT THE
TEMP SOUNDING WHICH SHOULD WRM UP THE SFC BUT AT THE SAME TIME
COLDER AIR MOVES IN ALOFT. THIS WILL FORCE PRCP OVER TO -SHSN OR
-SHRA CHANGING OVER TO -SHSN WITH SOME ACCUMULATION PSBL ACROSS
THE N/MT ZONES. GENERALLY USED GFS40 AND A BLEND OF MAV/MET MOS
ALONG WITH RFC QPF FOR THE NEAR TERM FCST.
&&
.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
A SECOND CD FNT MOVES THRU LATER TNGT AND OUT TO SEA SATURDAY
MORNING. SHSN AND SOME ACCUMULATION, MAINLY N/MT ZONES, PSBL WITH
THIS FNT WITH DRYER AND MUCH COLDER AIR MOVING IN ON GUSTY NW
WINDS BEHIND THE FNT FOR LATE TNGT AND SATURDAY. GENERALLY USED
GFS40 AND A BLEND OF MAV/MET MOS ALONG WITH RFC QPF FOR THE SHORT
TERM FCST.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AN UPPER TROUGH AND BELOW NORMAL TEMPERATURES WILL DOMINATE ACROSS
THE NORTHEAST FOR MUCH OF THE PERIOD. A BRIEF RESPITE TUESDAY...WITH
RIDGING AND WEST-SOUTHWEST FLOW TO PROVIDE A ONE DAY WARM UP AND
WELL ABOVE NORMAL TEMPERATURES. WE BEGIN THE PERIOD WITH ARCTIC
HIGH PRESSURE BUILDING EAST ACROSS THE FORECAST AREA SATURDAY
NIGHT THROUGH MONDAY WITH WELL BELOW NORMAL TEMPERATURES. A COLD
FRONT APPROACHES FROM THE MIDWEST MONDAY NIGHT AND TUESDAY PRECEDED
BY A MILDER SOUTHWEST FLOW. THE COLD FRONT WILL EXIT THE COAST
EARLY WEDNESDAY FOLLOWED BY A FRESH SHOT OF ARCTIC AIR. A WEAK
CLIPPER SYSTEM WILL CROSS THE REGION THURSDAY INTO FRIDAY.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
SHORT TERM /TODAY THROUGH SATURDAY/...VARIABLE CONDITIONS WITH
MOSTLY IFR TO LIFR CIG/VSBY ALONG WITH MIXED, THOUGH MOSTLY FZRA,
THIS MORNING INTO THIS AFTERNOON. IMPROVING CONDITIONS THIS
AFTERNOON BUT WITH GUSTY W SW WINDS SETTING UP BEHIND A CD FNT. A
SECOND CD FNT MAY BRING SOME -SHSN TO MAINLY THE N/MT AREAS TNGT
BUT WITH IMPROVING CONDITIONS FOR MOST TAF SITES. THE IMPROVING
TREND WILL CONT ON SATURDAY.
LONG TERM...
MON PM - TUE...AREAS OF MVFR POSSIBLE IN RAIN AND SNOW SHOWERS.
TUE...SW SFC WIND MAY GUST TO 25 KT.
&&
.MARINE...
SHORT TERM /TODAY THROUGH SATURDAY/...WILL CONT THE GLW THRU TNGT.
WINDS WILL BELOW GALE FORCE THIS MORNING BUT PICK UP LATER ON AS A
CD FNT MOVES THRU AND A STRONG SW PRES GRADIENT SETS UP AND
CONTINUES INTO TNGT UNTIL A CD FNT APPROACHES THE WATERS TOWARD
DAYBREAK. COULD SEE A FEW GUSTS INTO STORM FORCE...AROUND 50 KT
LATER TDA AND TNGT. WINDS SLOWLY LET UP SATURDAY AS THE PRES
GRADIENT LETS UP...BUT A CD NW FLOW OVER THE WARMER WATER WILL
STILL KEEP SOME GUSTINESS AROUND.
LONG TERM...
MON PM - TUE...GALE FORCE WINDS ARE POSSIBLE.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...GALE WARNING UNTIL 7 AM EST SATURDAY FOR ANZ150>154.
&&
$$
JC
AREA FORECAST DISCUSSION
NWS GRAY ME
1131 AM EST FRI JAN 13 2012
.SYNOPSIS...
LOW PRESSURE WILL MOVE EAST FROM THE GREAT LAKES AND DOWN THE
SAINT LAWRENCE RIVER VALLEY DRAGGING A COLD FRONT ACROSS THE
REGION THIS AFTERNOON. A SECOND COLD FRONT WILL MOVE THROUGH LATE
TONIGHT OR EARLY SATURDAY. ARCTIC HIGH PRESSURE WILL BUILD EAST
ACROSS THE REGION SATURDAY NIGHT THROUGH MONDAY. A COLD FRONT WILL
APPROACH FROM THE MIDWEST MONDAY NIGHT AND TUESDAY THEN EXIT THE
COAST EARLY WEDNESDAY. A RIDGE OF HIGH PRESSURE FOLLOWS FOR
WEDNESDAY. A WEAK CLIPPER SYSTEM WILL CROSS THE AREA LATE NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATE...
HAVE TAKEN A VERY CLOSE LOOK AT WIND FIELDS THIS MORNING AND USED
NEW MIXING TECHNIQUES IN THE GRIDS INVOLVING MIXING HEIGHT AND
WIND FIELDS FROM SEVERAL MODELS INCLUDING THE HRRR AND RUC. EXPECT
WIND GUSTS IN THE 35 TO 40 MPH RANGE OVER SOUTHERN NEW HAMPSHIRE
AND FAR SOUTHWEST MAINE TO DEVELOP DURING THE AFTERNOON HOURS.
WITH A FRESH GLAZE OF ICE ON THE TREES FROM THIS MORNINGS FREEZING
RAIN AND FREEZING DRIZZLE...EXPECT SOME TREE LIMBS TO BE DOWNED.
HAVE COORDINATED WITH NH ON THIS...AND HAVE CALLED OBSERVERS IN
THE AREA...WHICH SUGGESTS ABOUT A TENTH TO TWO TENTHS OF AN INCH
OF ICE HAS ACCUMULATED ON TREES. THE RESULT...WITH THE APPROACHING
WIND AND THE CURRENT ICING WILL BE SCATTERED POWER OUTAGES. WILL
CONTINUE TO MONITOR THIS CLOSELY AND WILL BE ISSUING AN SPS IN THE
NEXT HOUR FOR THIS POTENTIAL.
MINOR EDITS TO THE REST OF THE GRIDS...HOWEVER...HAVE LOWERED THE
MAX TEMPS DOWN A BIT. THIS HAS A BIG IMPACT ON THE MIXES LEVELS
THIS AFTERNOON. EXPECT TEMPS TO JUMP FOR ABOUT AN HOUR (UPWARDS)
AFTER THE FROPA...THEN HEAD RIGHT BACK DOWN.
WITH THE APPROACH OF THE OCCLUSION...FREEZING DRIZZLE AND FREEZING
RAIN SHOULD BE ENDING SHORTLY IN PORTIONS OF NH. HAVE ALLOWED SOME
OF THE ADVISORIES TO EXPIRE.
PREV DISC...
WILL UPDATE TO INPUT LATEST OBSERVED DATA. NO REAL CHANGES AT
THIS TIME. THE UPR LVL TROF AND SFC LOW ARE EXITING INTO THE
MARITIMES EARLY THIS MORNING WITH NORTHERLY WINDS IN ITS WAKE KEEP
TEMPS BELOW FREEZING JUST ABOUT EVERYWHERE ACROSS THE FCST AREA.
THE ONLY PLACES THAT MAY STILL BE AROUND FREEZING ARE ALONG THE
IMMEDIATE COASTLINE OVER THE MID COAST REGION OF MAINE.
A MUCH LARGER UPR LVL CUTOFF SYSTEM TO OUR SW WILL LIFT OUT TO
THE NE AND WEAKEN TDA AS IT FORCES A SFC LOW TO TRACK FROM THE ERN
GREAT LAKES DOWN THE ST LAWRENCE RIVER VALLEY TDA. A TRAILING CD
FNT WILL SWEEP FROM SW TO NE ACROSS THE FCST AREA LATE THIS
MORNING INTO THIS AFTERNOON. AHEAD OF THIS FNT CD AIR REMAINS AT
THE SFC WHILE WARMER AIR CONTINUES TO MOVE IN ALOFT. AN AREA OF
PRCP MOVES IN WITH THE UPR LVL AND SFC SYSTEMS...AND IS ALREADY
SHOWING UP ON THE RADAR MOSAIC LOOP WITH PRCP POISED TO MOVE INTO
OUR MOST SW ZONES AT THIS TIME.
PRCP WILL BE MOSTLY LGT FZRA THOUGH SOME IP OR EVEN SOME WET SN
PSBL ACROSS THE MORE NRN ZONES. COULD SEE SOME -RA ALONG THE MID
COAST REGION. WITH ACCUMULATING FZRA THRU THE MORNING AND INTO THE
AFTERNOON OVER MORE NRN AND ERN ZONES WILL CONT A FREEZING RAIN
ADVISORY. THERE COULD BE OTHER PRCP TYPES WITH THIS EVENT...
ESPECIALLY ACROSS THE N/MT ZONES BUT THE MAIN THREAT WILL BE FZRA
AND WANT TO HIGHLIGHT THAT.
AS THE FNT MOVES THRU GUSTY SW WINDS SET UP WHICH MIX OUT THE
TEMP SOUNDING WHICH SHOULD WRM UP THE SFC BUT AT THE SAME TIME
COLDER AIR MOVES IN ALOFT. THIS WILL FORCE PRCP OVER TO -SHSN OR
-SHRA CHANGING OVER TO -SHSN WITH SOME ACCUMULATION PSBL ACROSS
THE N/MT ZONES. GENERALLY USED GFS40 AND A BLEND OF MAV/MET MOS
ALONG WITH RFC QPF FOR THE NEAR TERM FCST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
A SECOND CD FNT MOVES THRU LATER TNGT AND OUT TO SEA SATURDAY
MORNING. SHSN AND SOME ACCUMULATION, MAINLY N/MT ZONES, PSBL WITH
THIS FNT WITH DRYER AND MUCH COLDER AIR MOVING IN ON GUSTY NW
WINDS BEHIND THE FNT FOR LATE TNGT AND SATURDAY. GENERALLY USED
GFS40 AND A BLEND OF MAV/MET MOS ALONG WITH RFC QPF FOR THE SHORT
TERM FCST.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
AN UPPER TROUGH AND BELOW NORMAL TEMPERATURES WILL DOMINATE ACROSS
THE NORTHEAST FOR MUCH OF THE PERIOD. A BRIEF RESPITE TUESDAY...WITH
RIDGING AND WEST-SOUTHWEST FLOW TO PROVIDE A ONE DAY WARM UP AND
WELL ABOVE NORMAL TEMPERATURES. WE BEGIN THE PERIOD WITH ARCTIC
HIGH PRESSURE BUILDING EAST ACROSS THE FORECAST AREA SATURDAY
NIGHT THROUGH MONDAY WITH WELL BELOW NORMAL TEMPERATURES. A COLD
FRONT APPROACHES FROM THE MIDWEST MONDAY NIGHT AND TUESDAY PRECEDED
BY A MILDER SOUTHWEST FLOW. THE COLD FRONT WILL EXIT THE COAST
EARLY WEDNESDAY FOLLOWED BY A FRESH SHOT OF ARCTIC AIR. A WEAK
CLIPPER SYSTEM WILL CROSS THE REGION THURSDAY INTO FRIDAY.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
SHORT TERM /TODAY THROUGH SATURDAY/...VARIABLE CONDITIONS WITH
MOSTLY IFR TO LIFR CIG/VSBY ALONG WITH MIXED, THOUGH MOSTLY FZRA,
THIS MORNING INTO THIS AFTERNOON. IMPROVING CONDITIONS THIS
AFTERNOON BUT WITH GUSTY W SW WINDS SETTING UP BEHIND A CD FNT. A
SECOND CD FNT MAY BRING SOME -SHSN TO MAINLY THE N/MT AREAS TNGT
BUT WITH IMPROVING CONDITIONS FOR MOST TAF SITES. THE IMPROVING
TREND WILL CONT ON SATURDAY.
LONG TERM...
MON PM - TUE...AREAS OF MVFR POSSIBLE IN RAIN AND SNOW SHOWERS.
TUE...SW SFC WIND MAY GUST TO 25 KT.
&&
.MARINE...
SHORT TERM /TODAY THROUGH SATURDAY/...WILL CONT THE GLW THRU TNGT.
WINDS WILL BELOW GALE FORCE THIS MORNING BUT PICK UP LATER ON AS A
CD FNT MOVES THRU AND A STRONG SW PRES GRADIENT SETS UP AND
CONTINUES INTO TNGT UNTIL A CD FNT APPROACHES THE WATERS TOWARD
DAYBREAK. COULD SEE A FEW GUSTS INTO STORM FORCE...AROUND 50 KT
LATER TDA AND TNGT. WINDS SLOWLY LET UP SATURDAY AS THE PRES
GRADIENT LETS UP...BUT A CD NW FLOW OVER THE WARMER WATER WILL
STILL KEEP SOME GUSTINESS AROUND.
LONG TERM...
MON PM - TUE...GALE FORCE WINDS ARE POSSIBLE.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...FREEZING RAIN ADVISORY UNTIL 11 AM EST THIS MORNING FOR MEZ018-
023.
FREEZING RAIN ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
MEZ007>009-012>014-019>022-024>028.
NH...FREEZING RAIN ADVISORY UNTIL 11 AM EST THIS MORNING FOR
NHZ005>010-013-014.
FREEZING RAIN ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
NHZ001>004.
MARINE...GALE WARNING UNTIL 7 AM EST SATURDAY FOR ANZ150>154.
&&
$$
JC
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
342 PM CST FRI JAN 13 2012
.SHORT TERM...TONIGHT THROUGH MONDAY.
THE PRIMARY CONCERNS IN THE SHORT TERM WILL THE HOW FAR SOUTHWEST
TO CARRY THE LIGHT SNOW AND FLURRIES OVERNIGHT AND EARLY
SATURDAY...TEMPERATURES SATURDAY AND SUNDAY...HOW FAR NORTH WILL
THE LIGHT RAIN AND DRIZZLE MAKE IT MONDAY MORNING...AND LIGHT SNOW
MOVING IN FROM THE WEST MONDAY.
AT 18Z...LIGHT SNOW RETURNS HAVE SPREAD INTO PARTS OF MT AND BY
20Z GGW WAS DOWN TO 1/2SM IN SNOW. SINCE THE OPERATIONAL MODELS
WERE ALL DRY AT THAT TIME IN MT...NOT REAL CONFIDENT IN HOW THEY
ARE HANDLING THIS SYSTEM. THE SHORTWAVE TROF OVER THE WRN DAKOTAS
IS FORECAST TO QUICKLY DROP SOUTHEAST OVERNIGHT INTO MISSOURI BY
12Z. THIS WITH WAA...UPWARD VERTICAL MOTION WITH THE WAVE...AND
POTENTIAL VORTICITY ADVECTION. THE 12Z/18Z CONTINUED DRY EXCEPT
FOR HARRISON CO IN IOWA. THE GFS HAS SOME LIGHT PRECIPITATION
MAKING IT INTO NORTHEAST NEB WHILE THE 00Z/12 EC/12Z 4KM WRF AND
THE LATEST HRRR ARE A BIT STRONGER WITH THE WAVE IN GENERATING
LIGHT SNOW FROM NORTHEAST NEBRASKA INTO WESTERN IOWA. ALTHOUGH
THERE ARE QUITE A FEW RETURNS SHOWING UP AT 21Z...SFC REPORTS ARE
STILL SPARSE IN REPORTING THE SNOW. LOOKING AT THE FORCING...
SATURATION...AND COLDEST TEMPS HAVE INCLUDED SOME SLIGHT CHC TO
CHC POPS OVER ESPECIALLY THE NORTHEASTERN THIRD OF THE CWA. AT
THIS TIME ONLY ADDED SOME VERY LIGHT AMOUNTS TO THE NORTHEAST.
ALTHOUGH SURFACE DEWPOINTS ARE VERY LOW (BELOW ZERO WRN IA AND THE
ALONG THE MISSOURI RIVER)...LOOK FOR THEM TO INCREASE OVERNIGHT
INTO THE TEENS AND 20S. WITH A SURFACE LOW TRACKING ACROSS THE
AREA OVERNIGHT...TEMPERATURES WILL BE TRICKY...FALLING OFF QUICKLY
TONIGHT IN WRN IOWA...BUT BEING HELD UP ACRS THE WRN CWA.
MID LEVEL RIDGING WILL BUILD IN FOR THE WEEKEND. WARMER
TEMPERATURES ARE FORECAST FOR WEEKEND WITH 50S FOR SUNDAY. THE
NEXT COLD FRONT MOVES THROUGH OVERNIGHT SUNDAY AND LOW CLOUDS AND
SOME DRIZZLE COULD DEVELOP IN SOUTHWEST IOWA. COLDER AIR WILL
RETURN FOR MONDAY WITH LIGHT SNOW DEVELOPING OVER SOUTH DAKOTA AND
WESTERN AND CENTRAL NEBRASKA. THIS LIGHT SNOW COULD START TO MAKE
IT INTO PARTS OF THE WESTERN FORECAST AREA BY DAY/S END.
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY.
MODELS CERTAINLY DIVERGE REGARDING THE AMOUNT AND INTENSITY OF COLD
AIR PLUNGING INTO THE PLAINS BY MID TO LATE WEEK. THE OPERATIONAL
GFS HAS REMAINED THE COLDEST OF THE MEDIUM RANGE MODELS...WITH ECMWF
THE WARMEST. GFS ENSEMBLE MEMBERS OFFER NO HELP AS THE SPREAD IS
WIDE HERE TOO. IN FACT...THE 00Z ENSEMBLE TEMPERATURES FOR THURSDAY
HIGHS RANGED FROM 21 TO 49 AT OMAHA.
LEADING UP TO THIS TIME PERIOD...A SIMILAR EVOLUTION OF THE UPPER
FLOW PATTERN IS NOTED BY GFS/ECMWF. BOTH SHOW A BROAD TROUGH OVER
THE CENTER OF THE COUNTRY WITH A SHORTWAVE MOVING THROUGH NEBRASKA
AND IOWA MONDAY NIGHT AND TUESDAY. AND BOTH MODELS BREAK OUT LIGHT
SNOW WITH THIS SYSTEM...ESPECIALLY ACROSS NORTHERN NEBRASKA INTO
NORTHERN IOWA. OUR CURRENT FORECAST HAS LIGHT SNOW IN THE FORECAST
MONDAY NIGHT...SO LEFT THAT UNCHANGED. HOWEVER...SLIGHTLY SLOWER
ECMWF KEEPS SNOW IN FOR TUESDAY. IF THIS OCCURS IT SHOULD ONLY
AFFECT OUR EAST AND SHOULD BE ENDING QUICKLY IN THE MORNING.
THEN UPPER PATTERN BEGINS TO FLATTEN OUT SOME...WITH NORTHWEST FLOW
THE CONSENSUS FOR WEDNESDAY. HIGHS IN THE 20S TUESDAY IN COOL
ADVECTION REGIME WILL WARM INTO THE 30S WEDNESDAY.
THURSDAY IS THE BIG QUESTION MARK AS THE GFS CONTINUES TO SHOW
STRONG BAROCLINIC ZONE DROPPING THROUGH THE CWA WHILE ECMWF KEEPS
BRUNT OF COLD AIR TO OUR NORTHEAST. DURING NORMAL WINTERS WOULD
EXPECT THE GFS AND COLD AIR TO WIN OUT...BUT THIS HAS BEEN ANYTHING
BUT A NORMAL WINTER. WE HAVE SEEN THESE SCENARIOS ADVERTISED AT DAYS
6 AND 7 BEFORE...AND TRENDING TOWARD WARMER SOLUTIONS HAS BEEN BEST.
ESPECIALLY WITH LIMITED SNOW COVER TO OUR NORTH. BOTH SIDES OF THE
ARGUMENT HAVE MERIT...SO TO STAY CONSISTENT WITH CURRENT
FORECAST...SURROUNDING OFFICES AND WIDELY DIVERGENT MODELS...WILL
HAVE TO KEEP TEMPERATURES CLOSE TO WHAT WE CURRENTLY HAVE GOING WITH
HIGHS IN THE 20S AND LOWER 30S. WHATEVER THE CASE...EXPECT A LITTLE
WARMER CONDITIONS ON FRIDAY AS RETURN FLOW SETS UP. MAY ALSO SEE
SOME LIGHT SNOW WITH THIS SCENARIO.
&&
.AVIATION...
18Z TAFS FOR KOMA...KLNK...AND KOFK.
VFR CONDITIONS ARE EXPECTED TO PREVAIL AT ALL SITES THROUGH THE
TAF PERIOD. A FRONTAL BOUNDARY WILL APPROACH THE CWA THIS
AFTERNOON...BRINGING WINDS AROUND TO THE SOUTHEAST AHEAD OF THE
FRONT. OVERNIGHT...WINDS BEHIND THE FRONT ARE EXPECTED TO
INCREASE AND SWITCH TO THE NORTHWEST.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
ZAPOTOCNY/DERGAN/ROURKE