Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 01/18/13
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1002 AM MST WED JAN 16 2013
.UPDATE...
&&
.SHORT TERM...CURRENT FORECASTS LOOKING ON TRACK. UPPER RIDGE TO
BEGIN BUILDING OVER THE REGION WITH NORTHWEST FLOW ALOFT. AIRMASS
TO BE MUCH WARMER WITH RAP SHOWING 700 TEMPS AROUND MINUS 4
CELSIUS BY 00Z. WITH MAINLY CLEAR SKIES EXPECTED...TEMPERATURES
SHOULD REBOUND TO NEAR NORMAL VALUES. BUT COLD AIR WILL REMAIN
TRAPPED IN MOUNTAIN VALLEYS WHICH WILL LIMIT THE WARMUP. ACROSS
PLAINS...THERE IS SOME SNOW COVER IN SPOTS WHICH WILL HINDER
WARMUP. CURRENT TEMPERATURES ARE SLOW TO WARM...AS LOW LEVEL
INVERSION REMAINS. FORECAST MAX TEMPERATURES SEEM REASONABLE FOR
NOW...THINKING THE INVERSION WILL BE BREAKING. WILL CONTINUE TO
MONITOR.
.AVIATION...LATEST MODELS INDICATING SOME SORT OF A NORTHEAST
COMPONENT AT THE AREA AIRPORTS THIS AFTERNOON...WITH PERHAPS THE
DEVELOPMENT OF AN ANTICYCLONE NORTH OF DENVER. CURRENT THINKING OF
A COUNTERCLOCKWISE TREND IN THE WINDS LOOKING MORE REASONABLE AND
WILL ADJUST WITH THE UPCOMING ISSUANCE. REST OF TAF TRENDS LOOK
GOOD.
&&
.PREV DISCUSSION... /ISSUED 405 AM MST WED JAN 16 2013/
SHORT TERM...TEMPERATURES HAVE REMAINED QUITE MILD OVERNIGHT
THANKS TO CLOUD COVER. BREEZY CONDITIONS WERE ALSO NOTED OVER THE
NORTHEAST PLAINS...AIDING MIXING. AS A RESULT...INVERSIONS ARE
QUITE WEAK THIS MORNING. FURTHER WARM ADVECTION WILL OCCUR THROUGH
THE DAY...AND SUNSHINE WILL RETURN IN EARNEST AS AIRMASS DRIES.
THERE WAS STILL SOME MID/HIGH LEVEL CLOUD COVER TO OUR NORTH...BUT
THIS WILL GRADUALLY THIN AND SEE LITTLE CHANCE OF MOUNTAIN WAVE
ENHANCEMENT WITH SUCH NORTHERLY FLOW. WRF AND NAM SYNTHETIC
SATELLITE IMAGERY ALSO SUPPORTS MAINLY SUNNY SKIES AFTER A FEW
EARLY MORNING CLOUDS. OVERALL...THIS SUPPORTS TEMPERATURES CLOSER
TO WARMER GFS MOS GUIDANCE. HOWEVER...THERE ARE SOME AREAS OF 1-4
INCH SNOW COVER ON THE PLAINS SO WILL HOLD THOSE LOCATIONS BACK
ABOUT 10 DEGREES.
FOR TONIGHT...CLEAR SKIES AND LIGHTER WINDS WILL ALLOW STRONGER
INVERSIONS TO REESTABLISH THEMSELVES. DESPITE THEIR BRIEF RESPITE
TODAY THANKS TO THE MILD START...HIGH MOUNTAIN VALLEYS WILL LIKELY
SETTLE BACK INTO COLDER TEMPERATURES DUE TO AMPLE SNOW COVER
THERE. OTHERWISE EXPECT MIN TEMPS NEAR NORMALS.
LONG TERM...SYNOPTIC SCALE MODELS ARE IN STRONG AGREEMENT THAT
THE NEXT WEEK IS GOING TO BE DOMINATED BY A STABLE AND PERSISTENT
RIDGE/TROUGH PATTERN ACROSS THE UNITED STATES. THIS WILL LEAVE
COLORADO UNDER DRY AND MILD NORTHWESTERLY FLOW ALOFT AND
PERSISTENT SUBSIDENT FORCING. CHANCES FOR PRECIPITATION WILL
ESSENTIALLY BE NIL THROUGH THE FORECAST PERIOD. TEMPERATURES WILL
MODERATE THROUGH THE WEEKEND...MORESO ON THE PLAINS THAN IN THE
MOUNTAIN VALLEYS. COLD AIR TRAPPED IN NORTH AND MIDDLE PARKS WILL
BE HARD TO SCOUR OUT. THERE WILL BE A BRIEF INTRUSION OF COLD AIR
INTO NORTHEAST COLORADO AS AN ALBERTA CLIPPER-LIKE SHORTWAVE
RACES THROUGH THE NORTHWEST FLOW THAT WILL BE IN PLACE. AT THIS
TIME THE INTRUSION OF COLD AIR LOOKS LIKE IT WILL BE QUITE SHALLOW
WITH LITTLE IMPACT ON THE AMOUNT OF MOISTURE OVER THE STATE.
TEMPERATURES WILL BE MUCH COOLER FOR THE MARTIN LUTHER KING
HOLIDAY...BUT THEN THEY ARE EXPECTED TO REBOUND NICELY FOR NEXT
TUESDAY AND WEDNESDAY AS THE WESTERN U.S. UPPER RIDGE AMPLIFIES
FOR A COUPLE DAYS. PRESENT INDICATIONS FROM THE ECMWF AND GFS
MODELS ARE THAT THE RIDGE/TROUGH PATTERN REMAINS IN PLACE THROUGH
NEXT WEDNESDAY BEFORE A TROUGH BEGINS MOVING INTO THE PACIFIC
NORTHWEST AND BEGINS BREAKING DOWN THE UPPER RIDGE LATE NEXT WEEK.
AVIATION...VISUAL LANDING CONDITIONS WILL PERSIST. WIND DIRECTION
WILL START OFF SOUTHWESTERLY AROUND 10 KTS...THEN SHOULD GRADUALLY
SHIFT MORE SOUTH/SOUTHEAST BY 16Z-18Z. WINDS THIS AFTERNOON WILL
BE MORE DIFFICULT DUE TO POSSIBLE INTERACTION WITH SNOW COVER OR
ANTICYCLONE...OR A COMBINATION OF THESE. FOR NOW...WILL OPT TOWARD
AN EAST/SOUTHEAST COMPONENT BUT SOME THREAT OF NORTHERLY WINDS UP
TO 10 KTS WILL BE POSSIBLE AT KDEN FROM 19Z-02Z. AFTER 02Z...
NORMAL SOUTH/SOUTHWEST WINDS 7-12 KTS WILL OCCUR.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...D-L
LONG TERM....DANKERS
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1008 PM MST TUE JAN 15 2013
.AVIATION...
VFR CONDITIONS EXPECTED AT ALL THREE TERMINALS THROUGH THE NEXT 24
HOURS. THE ONLY UNCERTAINTY FOR TONIGHT WILL BE WHETHER OR NOT FOG
OR STRATUS DEVELOP AT KALS LATE TONIGHT. GIVEN PERIODS OF MID TO
HIGH LEVEL CLOUD COVER ACROSS THE REGION...HAVE LEFT MENTION OF
FOG/STRATUS OUT OF THE FORECAST FOR NOW. MOZLEY
&&
.PREV DISCUSSION... /ISSUED 802 PM MST TUE JAN 15 2013/
UPDATE...
QUICK UPDATE TO BACK OFF POPS ACROSS THE NM/CO BORDER THROUGH 12Z
IN COORD WITH ABQ...AS LATEST RAP AND NAM12 SHOW ZERO QPF IN THOSE
AREAS IN THE SHORT TERM. -PJC
PREV DISCUSSION... /ISSUED 320 PM MST TUE JAN 15 2013/
SHORT TERM...
(TONIGHT AND WEDNESDAY)
.WARMER WEATHER IS ON THE WAY...
NICE RECOVERY ACROSS THE PLAINS TODAY...DESPITE A HIGH BKN CLOUD DECK
FROM AN APPROACHING SHORTWAVE. TEMPS RIGHT AROUND FREEZING AS OF MID
AFTERNOON...WHILE MTS AND HIGH VALLEYS GENERALLY REMAIN IN THE SINGLE
DIGITS TO TEENS.
NOT MUCH SHOWING UP ON WSR RIGHT NOW...BUT UPSTREAM OBS OVER NRN COL
AND SRN WY SHOW CIGS DROPPING TO THE 030-040 RANGE...AND EXPECT THE
TREND IN THICKER CLOUD COVER TO CONTINUE THROUGH THIS AFTERNOON AND
INTO THIS EVE. 18Z NAM HAS REALLY BACKED OFF QPF OVER OUR AREA...BUT
STILL EXPECT SOME ISOLD-SCT LIGHT SHSN OVER THE MTS AND PORTIONS OF
TELLER AND NRN EL PASO COUNTIES THIS EVE. VERY LITTLE IF ANY
ACCUMULATION EXPECTED. MAIN IMPACT OF THIS DISTURBANCE WILL BE
THICKER CLOUD COVER...RESULTING IN MILDER OVERNIGHT TEMPS ESPECIALLY
OVER THE PLAINS...AND A PERIOD OF GUSTY WINDS OVER THE PLAINS LATE
TONIGHT AND EARLY WED MORNING. N SIDE OF PIKES PEAK AND PORTIONS OF
TELLER COUNTY AND THE PALMER DVD...ALONG WITH THE WETS AND
SANGRES...WILL SEE THE MOST WIND...AS H7 WINDS FROM 40-50 KTS SWEEP
OVER THE ERN PLAINS TONIGHT.
WED LOOKS COMPLETELY DRY...WITH PLENTY OF SUN FOR THE AFTERNOON. THE
CENTRAL MTS COULD SEE SOME LINGERING CLOUDS THROUGH THE DAY...BUT NO
PRECIP EXPECTED AS AN UPPER RIDGE BUILDS RAPIDLY FROM THE W. IT WILL
BE QUITE MILD FOR THE PLAINS...WITH TEMPS LIKELY IN THE
50S...POSSIBLY NEARING 60 IF THE WINDS ARE A BIT STRONGER FROM THE W.
MTS AND HIGHER ELEVS WEST WILL STILL BE CHILLY...BUT COMPARATIVELY
BALMY AFTER THIS RECENT COLD SNAP...WITH TEMPS LARGELY IN THE 20S.
44
LONG TERM...
(WEDNESDAY NIGHT THROUGH NEXT TUESDAY)
MAINLY A TEMPERATURE FORECAST THE NEXT SEVERAL DAYS AS UPPER RIDGE
REMAINS IN PLACE OVER THE WESTERN U.S. THROUGH AT LEAST THE
MIDDLE OF NEXT WEEK...LEADING TO A DRY FORECAST FOR ALL OF THE
AREA AS WEATHER SYSTEMS ARE SHUNTED WELL NORTHEAST OF THE STATE.
A WEAK WAVE MOVING THROUGH THE RIDGE THU WILL PRODUCE ONLY A FEW
CLOUDS ACROSS THE REGION...THOUGH IT MAY SERVE TO SLOW THE WARM-UP
FOR A DAY...ESPECIALLY OVER THE PLAINS. TEMPS BEGIN TO WARM AGAIN
ON FRI INTO SAT...THEN A WEAK COLD FRONT BACKS INTO THE AT LEAST
THE FAR SOUTHEAST PLAINS SUNDAY...COOLING MAX TEMPS A FEW DEGREES
ALONG AND EAST OF THE MOUNTAINS. UNFORTUNATELY...UPPER RIDING WILL
KEEP COLD...STAGNANT AIR MASS IN PLACE OVER THE SAN LUIS
VALLEY...LEADING TO A MUCH SLOWER WARMING TREND HERE THAN
EVERYWHERE ELSE IN THE REGION. STILL...EXPECT DAYTIME HIGHS AT
ALAMOSA TO CLIMB BACK INTO AT LEAST THE 20S BY THE WEEKEND...AND
OVERNIGHT LOWS WILL IMPROVE INTO MAINLY THE TEENS BELOW ZERO
VERSUS THE MINUS 30F READINGS WE`VE SEEN EARLIER THIS WEEK.
WESTWARD EXTENT OF ARCTIC AIR BECOMES THE CONCERN SUNDAY NIGHT
INTO MONDAY...AS STRONG HIGH PRESSURE DROPS SOUTH INTO THE CENTRAL
PLAINS BEHIND DEEP UPPER TROUGH OVER THE GREAT LAKES. GFS SUGGESTS
ANY COLD AIR OVER THE PLAINS WILL BE VERY SHALLOW AND ERODE BY MON
AFTERNOON AS W-NW SURFACE FLOW AND LEE TROUGH DEVELOP. ECMWF IS
MUCH COLDER...KEEPING THE COLD AIR PINNED AGAINST THE EASTERN
MOUNTAINS UNTIL MONDAY NIGHT...BEFORE WARMER AIR SURGES BACK EAST
TUES. FORECAST LEANS TOWARD THE ECMWF AT THIS POINT AS PROGGED
1047 MB SURFACE HIGH OVER WRN NEB MON AFTERNOON SUGGESTS COLD AIR
WILL BE FAIRLY DEEP AND DIFFICULT TO QUICKLY DISLODGE. WENT WELL
BELOW NUMERICAL MOS GUIDANCE AND SLIGHTLY BELOW MODEL CONSENSUS
TEMPS FOR TUE AFTERNOON...ESPECIALLY NEAR THE KS BORDER. TEMPS
BEGIN TO MODERATE ON TUES AS SURFACE RIDGE MOVES EAST AND LEE
TROUGH REFORMS OVER THE EASTERN PLAINS. --10
AVIATION...MAIN CONCERN WILL BE POTENTIAL FOR SHSN NR KCOS THIS
EVE...ALTHOUGH LATEST COMPUTER GUIDANCE SUGGESTS THAT MOST OF EL
PASO SHOULD STAY DRY TONIGHT. COULD STILL SEE A BRIEF PERIOD OF
MVFR CIGS. WINDS ALSO LOOK TO GET A BIT GUSTY LATE TONIGHT INTO
WED MORNING FROM THE NNW...WITH GUSTS TO 30 KTS OR SO OVER THE HYR
TRRN IN THE PIKES PEAK REGION...POSSIBLY REACHING THE KCOS
TERMINAL AT TIMES. CLEAR AND DRY WX IS EXPECTED FOR ALL SPOTS ON
WED. KALS COULD STILL SEE A BRIEF INTERVAL OF LOW CIGS OR SHALLOW
PC FG EARLY ON WED...BUT CONFIDENCE IN ANY WIDESPREAD RESTRICTION
TO VIS IS TOO LOW TO INCLUDE IN THE ALS TAF. 44
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
88/34
AREA FORECAST DISCUSSION
NWS ALBANY NY
700 PM EST THU JAN 17 2013
.SYNOPSIS...
A COLD FRONT WILL SETTLE SOUTH OF THE REGION TONIGHT. A STORM
SYSTEM PASSING WELL OFF THE MID ATLANTIC COAST WILL BRING SOME
CLOUDS TO THE REGION THIS EVENING...AND PERHAPS A FEW SNOW SHOWERS
OR FLURRIES FOR SOUTHEAST AREAS. HIGH PRESSURE WILL BUILD IN FOR
FRIDAY...BRINGING FAIR BUT COLD CONDITIONS. ANOTHER STORM SYSTEM
WILL APPROACH FROM THE GREAT LAKES FRIDAY NIGHT AND
SATURDAY...BRINGING CLOUDS AND SOME SNOW SHOWERS...AND FOLLOWED BY
ANOTHER SURGE OF VERY COLD AIR FOR SUNDAY THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AS OF 655 PM EST...A COLD FRONT CONTINUES TO MOVE SOUTHWARD ACROSS
SOUTHERN NEW ENGLAND THIS EVENING. TEMPS ARE GRADUALLY FALLING
INTO THE TEENS ACROSS THE SOUTHERN ADIRONDACKS...AND THROUGH THE
20S FOR AREAS NORTH OF THE MOHAWK RIVER VALLEY AND CAPITAL
DISTRICT.
A THICK CANOPY OF HIGH AND MID LEVEL CLOUDS CONTINUES TO COVER
MOST OF THE REGION...IN ASSOCIATION WITH MOISTURE STREAMING
NORTHWARD IN ASSOCIATION WITH THE STRONG UPPER LEVEL STORM SYSTEM
TRAVERSING THE SOUTHEAST STATES. LOW CLOUDS ARE PERSISTING SOUTH
AND EAST OF THE CAPITAL REGION. SOME HOURLY CHANGES TO T/TDS WERE
MADE BASED ON OBSERVATIONS.
THE LATEST HRRR INDICATES THAT AS THE MID LEVEL CLOUDS THICKEN
MORE THIS EVENING...THERE COULD BE SOME FEEDER/SEEDER PROCESSES
WITH THE LOWER CLOUD DECK WHICH COULD PRODUCE SOME LIGHT SNOW
SHOWERS OR FLURRIES FOR AREAS MAINLY SOUTH AND SOUTHEAST OF THE
GREATER CAPITAL DISTRICT...PARTICULARLY ACROSS PORTIONS OF THE
MID HUDSON VALLEY...EXTREME SOUTHERN BERKSHIRES...AND NW CT AFTER
MIDNIGHT. HAVE INCLUDED MENTION OF FLURRIES OVERNIGHT IN MOST OF
THESE AREAS...ALONG WITH MENTION OF SLIGHT CHC POPS FOR SNOW
SHOWERS ACROSS THE MID HUDSON VALLEY AND NW CT. IN THIS
REGION...CAN NOT COMPLETELY RULE OUT A COATING OF SNOW IN SOME
AREAS BY DAYBREAK.
THE HIGH/MID LEVEL CLOUD CANOPY SHOULD GRADUALLY THIN FROM NW TO
SE...STARTING AROUND MIDNIGHT...AND CONTINUING THROUGH DAYBREAK.
THIS RAISES A RATHER CHALLENGING TEMPERATURE FORECAST...ESP FOR
NORTHERN AREAS...AS ANY PERIOD OF CLEAR SKIES ALONG WITH
DECREASING WIND AND AT LEAST SOME SNOW COVER COULD LEAD TO A QUICK
DROP IN TEMPS. HAVE SIDED WITH...OR EVEN WENT A BIT BELOW THE
COLDER MOS FOR MIN TEMPS OVERNIGHT ACROSS NORTHERN AREAS...WITH
WIDESPREAD SUBZERO MINS EXPECTED. FURTHER SOUTH...HAVE SIDED WITH
THE COLDER MET MOS IN MOST AREAS...ALTHOUGH TOOK A BLEND OF THE
MAV/MET MOS ACROSS SOUTHERN AREAS WHERE CLOUDS COULD LAST LONGER.
ACROSS NORTHERN AREAS WHERE SUBZERO TEMPS ARE EXPECTED...WINDS
SHOULD DROP TO BELOW 5 MPH...AND THEREFORE NO WIND CHILL HEADLINES
ARE INDICATED.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
FRIDAY...A PERIOD OF MOSTLY SUNNY SKIES IS EXPECTED THROUGH MUCH
OF THE DAY IN VALLEY AREAS...BEFORE A COMBINATION OF WARM
ADVECTION...AND SOME LAKE MOISTURE WITH A BACKING NORTHWEST TO
WEST WIND ALLOW CLOUDS TO REDEVELOP LATER IN THE DAY ACROSS THE
WESTERN MOHAWK VALLEY/ADIRONDACKS...AND PERHAPS ACROSS THE
SCHOHARIE VALLEY/HELDERBERGS. HAVE SIDED WITH THE COLDER SIDE OF
MOS FOR MAX TEMPS...WITH GENERALLY 20-25 IN VALLEY AREAS FROM
ALBANY N AND W...AND 25-30 IN VALLEY AREAS SOUTH OF ALBANY...WHILE
MOST HIGHER ELEVATIONS ONLY REACH THE TEENS. SOME SNOW SHOWERS ARE
EXPECTED TO DEVELOP BY AFTERNOON ACROSS THE WESTERN ADIRONDACKS
AND MOHAWK VALLEY REGION.
FRIDAY NIGHT-SAT...AS A STRONG CLIPPER TYPE SYSTEM APPROACHES FROM
THE GREAT LAKES REGION...A SURGE OF MID LEVEL WARM ADVECTION IS
EXPECTED TO PRODUCE ABUNDANT CLOUDS FOR LATER FRI NIGHT INTO AT
LEAST SAT MORNING...AND PERHAPS WELL INTO SAT AFTERNOON ACROSS
NORTHERN AREAS...WHERE ISENTROPIC LIFT WILL PERSIST. ALSO...AREAS
OF SNOW SHOWERS AND FLURRIES WILL OCCUR IN NORTHERN AREAS FRI NT
INTO SAT AM. SOME COATINGS WILL BE POSSIBLE IN VALLEY AREAS NORTH
OF THE CAPITAL REGION...WITH PERHAPS 1-4 INCHES ACROSS PORTIONS OF
THE WESTERN MOHAWK VALLEY/ADIRONDACK REGION. TEMPS FRI NT SHOULD
INITIALLY FALL QUICKLY...BEFORE RISING LATER IN THE EVENING
THROUGH DAYBREAK SAT. HAVE GENERALLY WENT WITH THE COLDER SIDE OF
GUIDANCE FOR MINS...ESP ACROSS NORTHERN AREAS. ON SAT...DESPITE A
DEVELOPING SOUTHWEST FLOW...CLOUDS AND A LOW LEVEL INVERSION MAY
PREVENT TEMPS FROM RISING TO THE WARMER MAV MOS NUMBERS. HAVE
SIDED WITH THE COOLER MET MOS IN MOST AREAS...AND HAVE EVEN
UNDERCUT BY A FEW ACROSS NORTHERN AREAS...WITH MID 30S EXPECTED
ACROSS THE SOUTHERN ADIRONDACKS AND LAKE GEORGE/SARATOGA
REGION...AND UPPER 30S TO LOWER 40S IN VALLEY AREAS FURTHER SOUTH.
HOWEVER...ACROSS PORTIONS OF THE SE CATSKILLS AND MID HUDSON
VALLEY...MORE SUNSHINE...AND A GUSTY DOWNSLOPING SW FLOW SHOULD
BOOST TEMPS INTO THE 45-50 RANGE.
SAT NT...OUR REGION SHOULD REMAIN WITHIN THE WARM SECTOR OF THE
APPROACHING CLIPPER. AS A COLD FRONT APPROACHES FROM THE NORTHWEST
LATER AT NIGHT...CLOUDS AND SOME SNOW SHOWERS SHOULD DEVELOP BY
DAYBREAK SUNDAY ACROSS N/W AREAS...WHERE CHC POPS ARE INDICATED.
INCREASING CLOUDS...AND A BRISK S/SW WIND SHOULD PREVENT TEMPS
FROM FALLING MUCH...AND THEREFORE HAVE GONE ABOVE MOS...WITH UPPER
20S TO MID 30S EXPECTED REGIONWIDE FOR MINS.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
...BELOW NORMAL TEMPERATURES WILL PERSIST THROUGH THE EXTENDED
PERIOD.
NORMAL TEMPERATURES FOR THE PERIOD JAN 20TH THROUGH 23RD:
ALBANY: HIGHS AROUND 30. LOWS IN THE MID TEENS.
GLENS FALLS: HIGHS IN THE UPPER 20S. LOWS IN THE SINGLE DIGITS.
POUGHKEEPSIE: HIGHS IN THE MID 30S. LOWS IN THE MID TEENS.
BENNINGTON: HIGHS AROUND 30. LOWS NEAR 10.
PITTSFIELD: HIGHS IN THE UPPER 20S. LOWS NEAR 10.
MODEL GUIDANCE CONTINUES TO BE IN GOOD AGREEMENT IN REGARDS TO THE
LONGWAVE PATTERN FOR THE PERIOD WITH A LARGE TROUGH COVERING THE
EASTERN 2/3 OF THE CONUS WITH SHORT WAVES ROTATING ABOUT AN UPPER
LOW OVER HUDSON/S BAY CANADA AND RIDGING ALONG THE WEST COAST.
NOW...EVEN THE DIFFERENCES IN THE LONG RANGE MODELS WERE IN PRETTY
GOOD AGREEMENT.
A POTENT CLIPPER...TRACKING ACROSS THE GREAT LAKES...WILL DRIVE AN
ARCTIC FRONT ACROSS THE REGION ON SUNDAY. THIS FRONT STILL LOOKS TO
HAVE DECENT UPPER LEVEL DYNAMICS AND A SHARP THERMAL GRADIENT
ASSOCIATED WITH IT...SO A ROUND OF SNOW SHOWERS/SQUALLS IS POSSIBLE
WITH THE FRONTAL PASSAGE. A SOUTH OR SOUTHWEST WIND WILL SHIFT
WEST-NORTHWEST AND DRIVE H850 TEMPS FROM ABOUT -2C EARLY...TO NEARLY
-20C BY LATE IN THE DAY! TEMPERATURES MIGHT ACTUALLY SPIKE IN THE
MORNING...THEN DROP DURING THE AFTERNOON ACROSS THE ENTIRE REGION.
HOWEVER THIS FAR OUT...WE JUST USED THE CLIMATOLOGICAL DIURNAL TREND
IN THE GRIDS SINCE A CHANGE IN THE ARRIVAL OF THIS REALLY COLD AIR
WOULD CHANGE HOURLY TEMPERATURES QUITE A BIT.
BY SUNDAY NIGHT WITH 850 MB TEMPERATURES LOOK TO HAVE DROPPED TO
BETWEEN -15 TO -20 C ACROSS THE FORECAST AREA. A WESTERLY WIND OF 10
TO 20 MPH WILL MAKE IT FEEL EVEN COLDER. WIND CHILL VALUES MAY REACH
ADVISORY CRITERIA (-20F) ACROSS THE SOUTHERN ADIRONDACKS AND THE
HIGHER TERRAIN OF SOUTHERN VERMONT. WILL HAVE MENTION IN OUR
HAZARDOUS WEATHER OUTLOOK.
SHORT WAVES ROTATING ABOUT THE UPPER LOW WILL BRING REINFORCING
SHOTS OF COLDER AIR TO THE REGION AS ADDITIONAL CLIPPER SYSTEMS MOVE
THROUGH MONDAY THROUGH WEDNESDAY. THIS WILL KEEP CLOUDS AND THE
THREAT OF SNOW SHOWERS IN THE FORECAST...ESPECIALLY DOWNWIND OF LAKE
ONTARIO. AT THIS POINT THE SYSTEMS WILL HAVE LIMITED MOISTURE
ASSOCIATED WITH THEM SO ANY PRECIPITATION/SNOW SHOULD BE LIGHT.
ONE THING TO WATCH ON TUESDAY. IT STILL APPEARS THAT A STORM IN THE
SOUTHERN JETSTREAM SHOULD MOVE WELL SOUTH AND EAST OF OUR REGION OUT
INTO THE OCEAN. HOWEVER...EVEN IF IT DOES...INTERACTION BETWEEN THIS
SYSTEM AND A POSSIBLE SHORTWAVE REINFORCING THE TROUGH OVER
US...MIGHT PRODUCE BROAD ASCENT TO GIVE OUR ENTIRE AREA LIGHT SNOW
OR SNOW SHOWERS TUESDAY. AGAIN...THIS SCENARIO IS NOT ETCHED IN
STONE...AND FOR NOW...ONLY WENT SLIGHT CHANCES IN AREAS OUTSIDE THE
ELEVATED TERRAIN TO THE WEST OF THE HUDSON VALLEY WHERE WE WENT LOW
POPS DUE TO MORE LAKE AVAILABLE EFFECT MOISTURE.
AS THE AFOREMENTIONED OCEAN STORM WINDS UP LATE TUESDAY...IT LOOKS
TO DRIVE ANOTHER SURGE OF ARCTIC AIR OUR WAY FOR TUESDAY...WITH SOME
INDICATIONS THAT H850 TEMPERATURES COULD BE EVEN COLDER (IN THE -20C
TO -25C RANGE). OF COURSE THIS NEW SURGE OF ARCTIC AIR COULD COME
WITH ANOTHER ROUND OF SNOW SHOWERS/SNOW SQUALLS AND LAKE EFFECT
SNOW.
INITIALLY THE ENVIRONMENT LOOKS SOMEWHAT SHEARED FOR SIGNIFICANT
LAKE EFFECT ACCUMULATIONS. HOWEVER...BY LATE TUESDAY INTO
WEDNESDAY...THE FLOW LOOKS TO BECOME MORE CYCLONIC WITH LESS SHEAR
AND VERY COLD AIR PRODUCING POTENTIAL EXTREME SLANTWISE INSTABILITY
OFF LAKE ONTARIO. WE WILL MONITOR THE LAKE EFFECT POTENTIAL THROUGH
THE PERIOD.
TEMPERATURES WILL TO TOP OUT IN THE 30S TO NEAR 40 SUNDAY IN THE
HUDSON VALLEY (THE WARMEST READINGS AROUND POUGHKEEPSIE). HIGHER
TERRAIN WILL SEE HIGHS ONLY 25-30. AGAIN...TEMPERATURES COULD DROP
DURING THE AFTERNOON.
OVERNIGHT LOWS SUNDAY NIGHT THROUGH WEDNESDAY LOOK TO TUMBLE TO THE
TEENS FROM THE TRI-CITIES SOUTHWARD...AROUND ZERO TO SINGLE NUMBERS
FURTHER NORTH AND WEST. THIS ASSUMES SOME WIND (AS OPPOSED TO CALM
CONDITIONS). IF THE WIND WERE TO DECOUPLE ANY OF THESE NIGHTS WITH
EVEN A PARTIALLY CLEAR SKY...OVERNIGHT LOWS COULD BE A LOT
COLDER...ESPECIALLY UP NORTH.
DAYTIME HIGHS MONDAY THROUGH THURSDAY LOOK TO LOOK TO BE 20-25 IN
THE HUDSON VALLEY FROM ALBANY SOUTHWARD...TEENS FURTHER NORTH...WITH
SOME READINGS AROUND 10 ACROSS THE ADIRONDACKS. THESE VALUES MIGHT
NOT BE COLD ENOUGH BUT AS WE GET CLOSER TO THIS TIME PERIOD...WE
WILL ADJUST THEM AS NEEDED.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
A COLD FRONT CONTINUES TO MOVE SOUTH OF SOUTHERN NEW ENGLAND AND
WILL INTERACT WITH A LOW PRESSURE SYSTEM OVER THE MID ATLANTIC
REGION. VFR CONDITIONS ARE EXPECTED...AS HIGH PRESSURE WILL BE
BUILDING IN FROM THE ERN GREAT LAKES REGION...AND WILL KEEP THE
STORM SYSTEM SOUTH AND EAST OF MUCH OF THE NORTHEAST OVERNIGHT.
MID AND HIGH CLOUDS WILL LINGER FROM KALB-KPSF NORTH AND
EAST...WHILE SOME LOW CLOUDS /STILL VFR/ WILL LINGER NEAR KPOU.
THERE COULD BE A FEW FLURRIES OR SNOW SHOWERS AFTER MIDNIGHT NEAR
KPOU...SO A VCSH GROUP WAS USED THERE.
THE SKIES WILL CLEAR TOWARDS DAYBREAK WITH THE ARCTIC ANTICYCLONE
BUILDING IN OVER UPSTATE NY. A FEW-SCT CU OR CIRRUS WILL BE
AROUND...BUT VFR CONDITIONS WILL DOMINATE.
N/NW WINDS OF 5-10 KTS WILL LIGHTEN OVERNIGHT. THE WINDS WILL
INCREASE FROM THE W/NW AT AROUND 10 KTS TOMORROW AFTERNOON.
OUTLOOK...
FRI NIGHT-SAT...VFR...NO SIG WX.
SUN...MAINLY VFR. CHC -SHSN.
MON...VFR. SLIGHT CHC -SHSN.
TUE...VFR. CHC SUB-VFR CIG -SHSN.
&&
.HYDROLOGY...
MAINLY DRY AND COLD WEATHER WILL OCCUR OVER THE NEXT FIVE DAYS.
WHILE SOME SNOW SHOWERS ARE POSSIBLE OVER THE NEXT FEW DAYS ACROSS
NORTHERN AREAS...PRECIPITATION AMOUNTS WILL BE LIGHT AND IN THE
FORM OF SNOW. COLD TEMPERATURES...ESPECIALLY EARLY NEXT
WEEK...WILL CAUSE RIVER AND LAKE ICE TO FORM AND THICKEN.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...FRUGIS/KL
NEAR TERM...KL/WASULA
SHORT TERM...KL
LONG TERM...IAA/HWJIV
AVIATION...WASULA
HYDROLOGY...FRUGIS/KL
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
150 PM EST WED JAN 16 2013
...COLD FRONT ON THURSDAY ENDS THE STRETCH OF ABOVE NORMAL TEMPS...
...GALE WATCH IN EFFECT FOR PORTIONS OF THE COASTAL WATERS...
.SHORT TERM (THIS EVENING THROUGH FRIDAY NIGHT)...
18Z WATER VAPOR AND H4 RAP ANALYSIS SHOW A CONTINUED AMPLIFIED UPPER
LEVEL PATTERN OVER THE CONUS THIS WEDNESDAY MORNING. MAIN LONGWAVE
TROUGH AXIS OVER THE CENTRAL PORTION OF THE COUNTY IS UNDERGOING A
FRACTURE EVENT...WITH NORTHERN ENERGY LOBE CROSSING THE GREAT LAKES
REGION AND SOUTHERN VORTICITY CENTER CUTTING OFF OVER
CENTRAL/EASTERN TEXAS. THIS SOUTHERN ENERGY WILL BE PROGRESSIVE...
AND IS FORECAST TO BECOME QUITE A POTENT LITTLE UPPER LOW AS IT
MOVES ALONG THE NORTHERN GULF COAST THE NEXT 24-30 HOURS.
CLOSER TO HOME...THE PENINSULA IS EXPERIENCING ITS FINALLY DAY
UNDER THE SUPPRESSION OF THE UPPER RIDGE. THIS RIDGE HAS PROVIDED A
LONG DURATION OF DRY AND UNSEASONABLY WARM WEATHER FOR OVER A WEEK.
THE STRONG SYSTEM APPROACHING FORM THE WEST WILL COMPLETELY BREAK
DOWN THE RIDGE BY THIS TIME TOMORROW AND BRING COOLER AND MORE
SEASONABLE CONDITIONS FOR THE END OF THE WEEK.
AT THE SURFACE...HIGH PRESSURE CENTERED NORTH OF THE BAHAMAS
CONTINUES TO RIDGE BACK TO THE WEST INTO THE EASTERN GULF OF MEXICO.
FURTHER WEST WE FIND A CURRENTLY QUASI-STATIONARY FRONTAL BOUNDARY
EXTENDING FROM THE CENTRAL GULF NORTHWARD TO AL/GA. THIS FRONT WILL
RE-DEVELOP AND STRENGTHEN LATER TONIGHT/EARLY THURSDAY AS THE
APPROACHING UPPER LEVEL ENERGY TRIGGERS CYCLOGENESIS ALONG THE GA/SC
COAST. RELATED MASS FIELDS WILL QUICKLY PUSH THIS SURFACE BOUNDARY
THROUGH OUR AREA LATE THURSDAY MORNING INTO THE AFTERNOON.
OVERALL...DOES NOT APPEAR THAT WE WILL SEE ENOUGH MOISTURE RETURN
FOR A WIDESPREAD OR SIGNIFICANT RAIN EVENT AHEAD OF THIS FRONT...
HOWEVER...THERE WILL BE ENOUGH DEEP LAYER QG FORCING/SYNOPTIC
SUPPORT ALONG WITH INCREASING SURFACE FOCUS ALONG THE LOW LEVEL
BOUNDARY TO SUPPORT AT LEAST A BROKEN BAND OF SHOWERS DURING THE
DAYLIGHT HOURS. 12Z GUIDANCE CONTINUES TO INDICATE LOW QPF OF
GENERALLY A TENTH OF AN INCH OR LESS.
POSSIBLY MORE SIGNIFICANT IS THE WIND GUSTS POTENTIAL IN THE WAKE OF
THE FRONT...ESPECIALLY ALONG THE IMMEDIATE COAST. GFS/ECMWF ARE BOTH
SHOWING SUSTAINED WINDS OF 25-30 KNOTS OVER THE EASTERN GULF LATER
THURSDAY INTO THURSDAY EVENING. AT LEAST SOME OF THIS WIND ENERGY
WILL TRANSLATE TO THE COAST...AND WOULD NOT BE SURPRISED TO SEE
GUSTS OVER 30 MPH IN CLOSE PROXIMITY TO THE WATER DURING THAT TIME.
THE STRONG ONSHORE FLOW WILL ALSO PUSH A DECENT WESTERLY SWELL
TOWARD THE BEACHES. LATEST FORECAST SUGGEST A HIGH SURF ADVISORY
WILL BECOME NECESSARY FROM PINELLAS COUNTY SOUTHWARD ALONG THE
SUNCOAST THURSDAY EVENING THROUGH FRIDAY MORNING. THIS HIGH SURF AND
ONSHORE FLOW WILL ALSO SUPPORT AN ELEVATED RISK OF RIP CURRENTS LATE
THURSDAY AFTERNOON INTO FRIDAY.
COLD FRONT WILL CLEAR THE FORECAST AREA EARLY THURSDAY EVENING WITH
A COOLER AND DRIER AIRMASS ARRIVING ON GUSTY NORTHWEST/NORTH FLOW.
HIGH TEMPERATURES FOR MANY LOCATIONS ON THURSDAY ARE LIKELY TO OCCUR
DURING THE LATE MORNING OR MIDDAY AND THEN HOLD STEADY...OR EVEN
DROP THROUGH THE AFTERNOON HOURS IN THE POST-FRONTAL ENVIRONMENT.
THURSDAY NIGHT WILL FEEL COLD COMPARED TO WHAT THIS REGION HAS
EXPERIENCED LATELY. GENERALLY SPEAKING THE MOS IS TOO COLD ON THESE
EARLY ADVECTION NIGHTS AND HAVE RAISED THE MAV/MET CONSENSUS UP A
FEW DEGREES. EVEN STILL...WIDESPREAD 40S ARE EXPECTED...WITH EVEN
SOME UPPER 30S TOWARD LEVY COUNTY. ADD IN A LITTLE WIND...AND IT
WILL BE A CHILLY OVERNIGHT PERIOD.
SENSIBLE WEATHER FOR FRIDAY AND FRIDAY NIGHT WILL BE FAIR AS TEMPS
WILL BE BACK TO SEASONABLE LEVELS. ONCE AGAIN...RAISED THE MOS LOW
TEMPS A COUPLE DEGREES...ESPECIALLY OVER THE NATURE COAST ZONES DUE
TO AN UNFAVORABLE SURFACE RIDGE POSITION FOR SIGNIFICANT RADIATIONAL
COOLING.
&&
.LONG TERM (SATURDAY - TUESDAY)...
U/L RIDGE WILL PERSIST ALONG THE WEST COAST OF THE U.S. WITH A BROAD
TROUGH ACROSS THE REMAINDER OF THE CONUS. SURFACE HIGH PRESSURE
WILL HOLD OVER THE SOUTHEAST U.S. FRIDAY NIGHT AND SATURDAY WITH A
STATIONARY BOUNDARY SOUTH OF THE FORECAST AREA. BROAD EAST TO
NORTHEAST FLOW OFF THE ATLANTIC COMBINED WITH WARM AIR OVERRUNNING
THE COLDER AIR ACROSS WEST CENTRAL AND SOUTHWEST FLORIDA WILL CREATE
MOSTLY CLOUDY SKIES AND A FEW SPRINKLES OVER THE REGION. SURFACE
HIGH PRESSURE WILL HOLD OVER THE REGION SUNDAY WITH BOUNDARY LAYER
FLOW BACKING TO THE NORTH AND NORTHWEST ON MONDAY AS A REINFORCING
COLD FRONT MOVES ACROSS THE REGION. LITTLE DEEP LAYER MOISTURE OR
U/L SUPPORT TO WORK WITH SO ONLY EXPECT MOSTLY CLOUDY SKIES AS THE
FRONT PUSHES ACROSS THE AREA. MUCH COOLER DRIER AIR WILL ADVECT
ACROSS THE FORECAST AREA MONDAY NIGHT AND TUESDAY WITH CLEARING
SKIES AND BREEZY NORTH TO NORTHWEST WINDS.
&&
.AVIATION...
VFR CONDITIONS WILL PREVAIL THROUGH EARLY TONIGHT. AFTER ABOUT 08Z
TONIGHT SOME AREAS OF MVFR/LOCAL IFR CEILINGS WILL BE POSSIBLE AT
ALL TERMINALS WITH SOME MVFR/IFR VISIBILITIES AT LAL...PGD AND RSW.
SCATTERED SHOWERS WILL BE POSSIBLE AFTER ABOUT 13Z THURSDAY AHEAD OF
THE COLD FRONT WITH THE BOUNDARY MOVING ACROSS THE TERMINALS DURING
THE MIDDAY/EARLY AFTERNOON.
&&
.MARINE...
FORECAST WATERS RESIDE BETWEEN A RIDGE OF HIGH PRESSURE TO OUR EAST
AND A FRONTAL BOUNDARY OVER THE CENTRAL GULF OF MEXICO. SOUTH TO
SOUTHEAST FLOW WILL CONTINUE AHEAD OF THIS FRONT THROUGH TONIGHT.
THE COLD FRONT WILL STRENGTHEN AND QUICKLY TRANSLATE THROUGH THE
EASTERN GULF OF MEXICO ON THURSDAY. WINDS WILL SHIFT WEST AND
NORTHWEST BEHIND THE FRONT AND QUICKLY INCREASE TO HIGH END ADVISORY
LEVELS. THERE IS THE POTENTIAL FOR FREQUENT GUSTS TO NEAR GALE FORCE
THURSDAY AFTERNOON INTO THURSDAY NIGHT...ESPECIALLY NORTH OF
ENGLEWOOD...ALONG WITH SEAS BUILDING TO OVER 7 FEET AWAY FROM THE
COAST. WINDS WILL VEER TO THE NORTHEAST ON FRIDAY...BUT REMAIN
ELEVATED ALONG WITH SEAS THROUGH THE DAY.
&&
.FIRE WEATHER...
THE LONG PERIOD OF ABOVE AVERAGE TEMPERATURES IS COMING TO AN END
ACROSS THE FLORIDA PENINSULA. A COLD FRONT WILL CROSS THE AREA
THURSDAY AFTERNOON WITH A FEW SHOWERS AND THEN USHER IN A COOLER AND
DRIER AIRMASS FOR THE END OF THE WEEK. ALTHOUGH RELATIVE HUMIDITY
LEVELS WILL BE ABOVE CRITICAL VALUES ON THURSDAY...WINDS WILL BE
ELEVATED ALONG WITH DISPERSION INDICES. BREEZY CONDITIONS AND
ELEVATED DISPERSION INDICES ARE AGAIN EXPECTED FOR FRIDAY. AT THIS
TIME...THE FORECAST KEEPS RELATIVE HUMIDITY ABOVE 35 PERCENT...BUT
THE SITUATION WILL NEED TO BE MONITORED CLOSELY WITH FUTURE
FORECASTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 64 70 47 68 / 10 50 10 10
FMY 64 76 51 71 / 10 30 10 10
GIF 59 74 45 69 / 10 30 10 10
SRQ 64 71 50 69 / 10 40 10 10
BKV 57 70 42 66 / 10 50 10 10
SPG 66 69 50 66 / 10 50 10 10
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...GALE WATCH FROM THURSDAY AFTERNOON THROUGH LATE
THURSDAY NIGHT FOR ENGLEWOOD TO TARPON SPRINGS OUT 20 NM-
ENGLEWOOD TO TARPON SPRINGS OUT 20 TO 60 NM-TARPON
SPRINGS TO SUWANNEE RIVER OUT 20 NM-TARPON SPRINGS TO
SUWANNEE RIVER OUT 20 TO 60 NM.
&&
$$
SHORT TERM/MARINE/FIRE WX...MROCZKA
AVIATION...CLOSE
LONG TERM...OGLESBY
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
825 AM EST WED JAN 16 2013
.UPDATE (REST OF TODAY THROUGH FRIDAY)...
13Z WATER VAPOR AND H4 RAP ANALYSIS SHOW A CONTINUED AMPLIFIED UPPER
LEVEL PATTERN OVER THE CONUS THIS WEDNESDAY MORNING. MAIN LONGWAVE
TROUGH AXIS OVER THE CENTRAL PORTION OF THE COUNTY IS UNDERGOING A
FRACTURE EVENT...WITH NORTHERN ENERGY LOBE CROSSING THE GREAT LAKES
REGION AND SOUTHERN VORTICITY CENTER NOW CUTTING OFF OVER CENTRAL
TEXAS. THIS SOUTHERN ENERGY WILL HOWEVER ALSO BE PROGRESSIVE...AND
IS FORECAST TO BECOME QUITE A POTENT LITTLE UPPER LOW AS IT MOVES
ALONG THE NORTHERN GULF COAST THE NEXT 24-36 HOURS.
CLOSER TO HOME...THE PENINSULA WILL EXPERIENCE ITS FINALLY DAY UNDER
THE SUPPRESSION OF THE UPPER RIDGE. THIS RIDGE HAS PROVIDED A LONG
DURATION OF DRY AND UNSEASONABLY WARM WEATHER FOR OVER A WEEK. THE
STRONG SYSTEM APPROACHING FORM THE WEST WILL COMPLETELY BREAK DOWN
THE RIDGE BY THIS TIME TOMORROW AND BRING COOLER AND MORE SEASONABLE
CONDITIONS FOR THE END OF THE WEEK. AT LEAST FOR NOW...THE RIDGE IS
STILL DOMINANT IN OUR WEATHER. 12Z KTBW SOUNDING PROFILE CONTINUES
TO SHOW A WELL-DEFINED SUBSIDENCE INVERSION AROUND 830MB AND A DRY
PROFILE ABOVE THIS LEVEL. THE DEEP SUPPRESSION AND DECENT DIURNAL
MIXING SHOULD ALLOW TEMPS TO APPROACH OR SURPASS 80 FOR ONE FINAL
DAY AWAY FROM THE IMMEDIATE COAST.
AT THE SURFACE...HIGH PRESSURE CENTERED NORTH OF THE BAHAMAS
CONTINUES TO RIDGE BACK TO THE WEST INTO THE EASTERN GULF OF MEXICO.
FURTHER WEST WE FIND A CURRENTLY QUASI-STATIONARY FRONTAL BOUNDARY
EXTENDING FROM THE CENTRAL GULF NORTHWARD TO AL/GA. THIS FRONT WILL
RE-DEVELOP AND STRENGTHEN LATER TONIGHT/EARLY THURSDAY AS THE
APPROACHING UPPER LEVEL ENERGY TRIGGERS CYCLOGENESIS ALONG THE GA/SC
COAST. RELATED MASS FIELDS WILL QUICKLY PUSH THIS SURFACE BOUNDARY
THROUGH OUR AREA LATE THURSDAY MORNING INTO THE AFTERNOON.
OVERALL...DOES NOT APPEAR THAT WE WILL SEE ENOUGH MOISTURE RETURN
FOR A WIDESPREAD OR SIGNIFICANT RAIN EVENT AHEAD OF THIS FRONT...
HOWEVER...THERE WILL BE ENOUGH DEEP LAYER QG FORCING/SYNOPTIC
SUPPORT ALONG WITH INCREASING SURFACE FOCUS ALONG THE LOW LEVEL
BOUNDARY TO SUPPORT AT LEAST A BROKEN BAND OF SHOWERS DURING THE
DAYLIGHT HOURS THURSDAY. IN GENERAL...LIKELY LOOKING AT AT AROUND
A TENTH OF AN INCH OR LESS QPF.
POSSIBLY MORE SIGNIFICANT IS THE WIND GUSTS POTENTIAL IN THE WAKE OF
THE FRONT...ESPECIALLY ALONG THE IMMEDIATE COAST. GFS/ECMWF ARE BOTH
SHOWING SUSTAINED WINDS OF 25-30 KNOTS OVER THE EASTERN GULF LATER
THURSDAY INTO THURSDAY EVENING. AT LEAST SOME OF THIS WIND ENERGY
WILL TRANSLATE TO THE COAST AND WOULD NOT BE SURPRISED TO SEE GUSTS
OVER 30 MPH IN CLOSE PROXIMITY TO THE WATER DURING THAT TIME. THE
STRONG ONSHORE FLOW WILL ALSO PUSH A DECENT WESTERLY SWELL TOWARD
THE BEACHES. LATEST FORECAST WOULD SUGGEST A HIGH SURF ADVISORY MAY
BE NEEDED FROM PINELLAS COUNTY SOUTHWARD THURSDAY EVENING THROUGH
FRIDAY MORNING.
COLD FRONT WILL CLEAR THE FORECAST AREA EARLY THURSDAY EVENING WITH
COOLER AND GENERALLY DRY WEATHER RETURNING FOR FRIDAY.
&&
.AVIATION...
SOME MVFR/LOCAL IFR CONDITIONS EARLY THIS MORNING WILL LIFT AND
DISSIPATE WITH VFR CONDITIONS THEN PREVAILING INTO EARLY TONIGHT.
LATE TONIGHT INTO EARLY THURSDAY MORNING THERE COULD BE SOME MORE
MVFR/LOCAL IFR CONDITIONS...BUT MAINLY AT LAL...PGD AND RSW.
&&
.MARINE...
FORECAST WATERS RESIDE BETWEEN A RIDGE OF HIGH PRESSURE TO OUR EAST
AND A FRONTAL BOUNDARY OVER THE CENTRAL GULF OF MEXICO. SOUTH TO
SOUTHEAST FLOW WILL CONTINUE AHEAD OF THIS FRONT THROUGH TONIGHT.
THE COLD FRONT WILL STRENGTHEN AND QUICKLY TRANSLATE THROUGH THE
EASTERN GULF OF MEXICO ON THURSDAY. WINDS WILL SHIFT WEST AND
NORTHWEST BEHIND THE FRONT AND QUICKLY INCREASE TO ADVISORY LEVELS.
A FEW WIND GUSTS TO NEAR GALE FORCE APPEAR POSSIBLE LATE THURSDAY
AFTERNOON INTO THURSDAY NIGHT...ALONG WITH SEAS BUILDING TO OVER 7
FEET AWAY FROM THE COAST. WINDS WILL VEER TO THE NORTHEAST ON
FRIDAY...BUT REMAIN ELEVATED ALONG WITH SEAS THROUGH THE DAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 79 64 70 47 / 0 10 50 10
FMY 83 64 79 51 / 0 10 30 10
GIF 81 63 74 44 / 0 10 30 10
SRQ 78 62 71 49 / 0 10 40 10
BKV 81 57 70 42 / 0 10 50 10
SPG 79 65 68 52 / 0 10 50 10
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
UPDATE/MARINE...MROCZKA
AVIATION...CLOSE
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
338 AM EST WED JAN 16 2013
.UPDATE...
THE LONG TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 212 PM EST TUE JAN 15 2013
QUIET WEATHER CAN BE EXPECTED UNDER HIGH PRESSURE THROUGH THE END
OF THE WEEK WITH TEMPERATURES NEAR NORMAL FOR THIS TIME OF YEAR.
COULD SEE A BRIEF WARM UP SATURDAY INTO THE 40S BEFORE
TEMPERATURES DROP BACK TO NORMAL SUNDAY AND THEN GET VERY COLD TO
START OUT THE WEEK. A CLIPPER SYSTEM WILL MOVE THROUGH SUNDAY
NIGHT THROUGH MONDAY NIGHT BRINGING CHANCES FOR SNOW.
&&
.NEAR TERM /TONIGHT/...
ISSUED AT 929 PM EST TUE JAN 15 2013
LATEST SHORT TERM MODEL GUIDANCE ALONG WITH REGIONAL RADAR LOOPS
SUGGEST PRECIPITATION SHIELD ASSOCIATED WITH SYSTEM MOVING THROUGH
THE TENNESSEE VALLEY SHOULD STAY SOUTH OF THE FORECAST AREA TONIGHT
FOR THE MOST PART. ONLY HAVE SLIGHT CHANCE POPS GOING OVER THE FAR
SOUTHEAST FOR THE REST OF THE NIGHT...SO WILL LEAVE THE POP FORECAST
AS IS.
THIS EVENING/S UPPER AIR INDICATE TEMPERATURES NEAR OR BELOW
FREEZING THROUGHOUT THE COLUMN THIS FAR NORTH...SO THINK THE CHANCES
OF FREEZING RAIN THIS FAR NORTH ARE DIMINISHING.
FINALLY...WITH ONLY WEAK COLD ADVECTION TONIGHT AND SKIES REMAINING
CLOUDY MOST OF THE NIGHT...DECIDED TO BUMP UP THE LOWS A COUPLE OF
DEGREES.
PREVIOUS DISCUSSION FOLLOWS.
SKIES SHOULD START OUT MOSTLY CLOUDY WITH A LOW PRESSURE SYSTEM
MOVING NORTHEAST OUT OF THE GULF AND THROUGH THE SOUTHEASTERN U.S. A
BIT OF MODEL DISAGREEMENT OVER HOW FAR NORTH PRECIPITATION
ASSOCIATED WITH THIS SYSTEM WILL GET DESPITE SIMILAR POSITIONS AND
STRENGTH FOR THE LOW PRESSURE CENTER. THE RAP AND GEM WERE THE
FURTHEST NORTH AND BRING THE PRECIP INTO THE FAR SOUTHEASTERN
COUNTIES. THE GFS KEEPS THE PRECIP WELL TO THE SOUTH...WHILE THE NAM
AND 0Z ECMWF JUST CLIP THE FAR SOUTHEAST WITH A HUNDREDTH OF QPF.
WITH THE VARIETY OF SOLUTIONS SHOULD CARRY A LOW CHANCE POP IN THE
FAR SOUTHEAST WITH DRY WEATHER BUT MOSTLY CLOUDY SKIES ELSEWHERE.
WENT WITH LOWS A DEGREE OR TWO BELOW GUIDANCE WITH EXPECTED COLD
ADVECTION.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
ISSUED AT 212 PM EST TUE JAN 15 2013
HIGH PRESSURE WILL REMAIN OVER THE AREA THROUGH THE SHORT TERM. A
LOW PRESSURE SYSTEM MOVING ACROSS THE HUDSON BAY WILL DRAG A COLD
FRONT ACROSS THE GREAT LAKES WEDNESDAY AND WEDNESDAY NIGHT...BUT IT
LOOKS LIKE ALL THE FORCING ASSOCIATED WITH IT WILL STAY WELL NORTH
OF THE AREA. ANOTHER SOUTHERN LOW PRESSURE SYSTEM WHICH WILL MOVE
ACROSS THE SOUTHEAST U.S. DURING THE SAME TIME APPEARS TO BE TOO FAR
SOUTH TO IMPACT POPS HERE. GUIDANCE IS IN GOOD AGREEMENT AND WILL
USE AN AVERAGE WHICH RESULTS IN NEAR NORMAL TEMPERATURES AND DRY
WEATHER.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
ISSUED AT 338 AM EST WED JAN 16 2013
MAIN FOCUS CONTINUES TO BE ON TIMING AND MAGNITUDE OF ARCTIC FRONT
SET TO SETTLE SOUTHEAST ACROSS CENTRAL INDIANA EARLY NEXT WEEK.
OPERATIONAL MODELS ARE NOW IN MUCH CLOSER AGREEMENT ON TIMING OF
WESTERN LOBE OF NORTHERN ONTARIO VORTEX ACROSS CENTRAL INDIANA.
HOWEVER...THE 00Z GFS WAS STILL A BIT FASTER TO BRING IN THE ARTIC
FRONT JUDGED BY 1000-500 MILLIBAR THICKNESS FIELDS THAT BRING A 5040
METER LINE TO NORTHERN PARTS OF THE FORECAST AREA BY 00Z TUESDAY.
MEANWHILE...THE 00Z ECMWF WAS EVEN COLDER...5010 METERS...BUT 6
HOURS BEHIND BY 06Z TUESDAY. WITH OPERATIONAL MODELS TRENDING
TOWARDS THE ENSEMBLES...ENSEMBLES ARE PREFERED. HOWEVER...THE BETTER
DEFINED ARCTIC FRONT PER THE OPERATIONAL 00Z ECMWF AND GEM LOOKS A
BIT BETTER THAN THE 00Z GFS. THE REGIONAL INITIALIZATION APPEARS TO
BE EVEN A BIT SLOWER THAN THE SLOWER EURO AND GEM REGARDING THE
LOWEST THICKNESSES WITH THE ARCTIC AIRMASS. SO...LOWERED REGIONAL
HIGHS A COUPLE OF DEGREES ON MONDAY. AT ANY RATE...SATURDAY WILL BE
THE WARMEST DAY OF THE EXTENDED WITH SOUTHWEST FLOW AHEAD OF AN
INITIAL COLD FRONT THAT IS EXPECTED TO SURGE SOUTHEAST ACROSS
CENTRAL INDIANA LATE SATURDAY AND SATURDAY NIGHT. THIS FRONT WILL BE
MOISTURE STARVED...AND THUS DRY FORECAST LOOKS GOOD. THE FRONT WILL
SERVE TO BRING COLDER AIR IN TO CENTRAL INDIANA WITH HIGHS SATURDAY
IN THE 40S BUT ONLY IN THE UPPER 20S TO MID 30S SUNDAY PER THE
REGIONAL INITIALIZATION.
THE SLOWER AND BETTER DEFINED LEADING EDGE OF THE ARCTIC FRONT PER
THE 00Z EURO AND GEM LOOKS TO ARRIVE BY MONDAY MORNING BY 12Z. KEPT
SMALL SNOW CHANCES IN PER THE REGIONAL AND PERSISTANCE...BUT LIMITED
MOISTURE SUGGESTS LITTLE TO NO ACCUMULATION. WITH ARCTIC AIR
ENTRENCHED MONDAY NIGHT...SINGLE DIGIT LOWS LOOK GOOD WITH
TEMPERATURES WARMING NO HIGHER THAN THE TEENS ON TUESDAY.
&&
.AVIATION /DISCUSSION FOR 160600Z TAF ISSUANCE/...
ISSUED AT 1125 PM EST TUE JAN 15 2013
VFR CONDITIONS ANTICIPATED THROUGHOUT THE FORECAST PERIOD. LOW
PRESSURE SHIFTS INTO THE SOUTHERN APPALACHIANS LATE
TONIGHT...MOISTURE ALOFT WILL ALSO BEGIN TO DEPART OFF TO THE EAST
AND CEILINGS ARE EXPECTED TO LIFT AND SCATTER IN THE HOURS
APPROACHING DAYBREAK. HIGH PRESSURE RIDGE THEN BUILDS INTO THE
REGION TODAY WITH BROAD SUBSIDENCE. WILL SEE SKIES BECOME
MOSTLY CLEAR. LIGHT AND VARIABLE WINDS LATE TONIGHT WILL SHIFT TO
W/SW AND INCREASE TO NEAR 10KTS BY THIS AFTERNOON.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...CP/JAS
SHORT TERM...CP
LONG TERM....MK
AVIATION...SMF
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1123 PM EST TUE JAN 15 2013
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 212 PM EST TUE JAN 15 2013
QUIET WEATHER CAN BE EXPECTED UNDER HIGH PRESSURE THROUGH THE END
OF THE WEEK WITH TEMPERATURES NEAR NORMAL FOR THIS TIME OF YEAR.
COULD SEE A BRIEF WARM UP SATURDAY INTO THE 40S BEFORE
TEMPERATURES DROP BACK TO NORMAL SUNDAY AND THEN GET VERY COLD TO
START OUT THE WEEK. A CLIPPER SYSTEM WILL MOVE THROUGH SUNDAY
NIGHT THROUGH MONDAY NIGHT BRINGING CHANCES FOR SNOW.
&&
.NEAR TERM /TONIGHT/...
ISSUED AT 929 PM EST TUE JAN 15 2013
LATEST SHORT TERM MODEL GUIDANCE ALONG WITH REGIONAL RADAR LOOPS
SUGGEST PRECIPITATION SHIELD ASSOCIATED WITH SYSTEM MOVING THROUGH
THE TENNESSEE VALLEY SHOULD STAY SOUTH OF THE FORECAST AREA TONIGHT
FOR THE MOST PART. ONLY HAVE SLIGHT CHANCE POPS GOING OVER THE FAR
SOUTHEAST FOR THE REST OF THE NIGHT...SO WILL LEAVE THE POP FORECAST
AS IS.
THIS EVENING/S UPPER AIR INDICATE TEMPERATURES NEAR OR BELOW
FREEZING THROUGHOUT THE COLUMN THIS FAR NORTH...SO THINK THE CHANCES
OF FREEZING RAIN THIS FAR NORTH ARE DIMINISHING.
FINALLY...WITH ONLY WEAK COLD ADVECTION TONIGHT AND SKIES REMAINING
CLOUDY MOST OF THE NIGHT...DECIDED TO BUMP UP THE LOWS A COUPLE OF
DEGREES.
PREVIOUS DISCUSSION FOLLOWS.
SKIES SHOULD START OUT MOSTLY CLOUDY WITH A LOW PRESSURE SYSTEM
MOVING NORTHEAST OUT OF THE GULF AND THROUGH THE SOUTHEASTERN U.S. A
BIT OF MODEL DISAGREEMENT OVER HOW FAR NORTH PRECIPITATION
ASSOCIATED WITH THIS SYSTEM WILL GET DESPITE SIMILAR POSITIONS AND
STRENGTH FOR THE LOW PRESSURE CENTER. THE RAP AND GEM WERE THE
FURTHEST NORTH AND BRING THE PRECIP INTO THE FAR SOUTHEASTERN
COUNTIES. THE GFS KEEPS THE PRECIP WELL TO THE SOUTH...WHILE THE NAM
AND 0Z ECMWF JUST CLIP THE FAR SOUTHEAST WITH A HUNDREDTH OF QPF.
WITH THE VARIETY OF SOLUTIONS SHOULD CARRY A LOW CHANCE POP IN THE
FAR SOUTHEAST WITH DRY WEATHER BUT MOSTLY CLOUDY SKIES ELSEWHERE.
WENT WITH LOWS A DEGREE OR TWO BELOW GUIDANCE WITH EXPECTED COLD
ADVECTION.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
ISSUED AT 212 PM EST TUE JAN 15 2013
HIGH PRESSURE WILL REMAIN OVER THE AREA THROUGH THE SHORT TERM. A
LOW PRESSURE SYSTEM MOVING ACROSS THE HUDSON BAY WILL DRAG A COLD
FRONT ACROSS THE GREAT LAKES WEDNESDAY AND WEDNESDAY NIGHT...BUT IT LOOKS
LIKE ALL THE FORCING ASSOCIATED WITH IT WILL STAY WELL NORTH OF THE
AREA. ANOTHER SOUTHERN LOW PRESSURE SYSTEM WHICH WILL MOVE ACROSS
THE SOUTHEAST U.S. DURING THE SAME TIME APPEARS TO BE TOO FAR SOUTH
TO IMPACT POPS HERE. GUIDANCE IS IN GOOD AGREEMENT AND WILL USE AN
AVERAGE WHICH RESULTS IN NEAR NORMAL TEMPERATURES AND DRY WEATHER.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
ISSUED AT 248 PM EST TUE JAN 15 2013
FOCUS OF THE EXTENDED PERIOD REMAINS ON THE ARRIVAL OF WHAT
INCREASINGLY APPEARS TO BE THE COLDEST AIRMASS OF THE SEASON AS A
PIEICE OF THE POLAR VORTEX BREAKS OFF AND AMPLIFIES THE UPPER
TROUGH OVER THE EASTERN PART OF THE COUNTRY.
WARMEST DAY OF THE PERIOD WILL BE SATURDAY AS SOUTHERLY FLOW AHEAD
OF A COLD FRONT ENABLES TEMPS TO RISE INTO THE 40S ACROSS THE
FORECAST AREA. LOW PRESSURE WILL TRACK THROUGH THE GREAT LAKES
SATURDAY NIGHT AND BRING THE COLD FRONT THROUGH CENTRAL INDIANA BY
EARLY SUNDAY. THE FRONT WILL USHER IN THE INITIAL SHOT OF COLDER
AIR...AS TEMPS ARE LIKELY TO FALL BACK INTO THE 20S AND LOWER 30S.
PASSAGE OF THE FRONT LOOKS TO BE DRY AS DEEPER MOISTURE IS FOCUSED
CLOSER TO THE LOW ACROSS THE GREAT LAKES. ARCTIC FRONT SET TO DIVE
INTO THE REGION ON MONDAY...USHERING IN MUCH COLDER AIR AS 850MB
TEMPS NOSEDIVE. ANTICIPATE SNOW SHOWERS TO ACCOMPANY THE FRONTAL
PASSAGE AND AS WIND FLOW ALIGNS TO THE NORTHWEST IN ITS WAKE...
LIKELY TO SEE SOME IMPACTS FROM LAKE ENHANCEMENT SNOW SHOWERS
THROUGH MONDAY NIGHT.
THE MUCH GREATER IMPACT WITH THE FRONTAL PASSAGE WILL BE TO
TEMPERATURES AS 850MB TEMPS ON BOTH THE ECMWF AND OP GFS FALL INTO
THE -23 TO -21C RANGE BY TUESDAY. IF THESE NUMBERS EVEN COME CLOSE
TO VERIFYING...HIGH TEMPS ON TUESDAY ARE LIKELY TO STRUGGLE INTO
THE 10-15 DEGREE RANGE AND PROVIDE CENTRAL INDIANA WITH THE
COLDEST AIR OF THE SEASON TO DATE. KNOWING HOW MODELS THIS FAR OUT
TEND TO UNDEROD THE DEPTH OF ARCTIC COLD AND WITH GROWING
CONFIDENCE IN THE INTENSITY OF THE COLD AIRMASS...HAVE CHOSEN TO
UNDERCUT ALLBLEND TEMPS BY 3 TO 4 DEGREES FOR BOTH MONDAY AND
TUESDAY. LOWS MAY BE DOWN NEAR ZERO BY TUESDAY NIGHT.
&&
.AVIATION /DISCUSSION FOR 160600Z TAF ISSUANCE/...
ISSUED AT 1125 PM EST TUE JAN 15 2013
VFR CONDITIONS ANTICIPATED THROUGHOUT THE FORECAST PERIOD. LOW
PRESSURE SHIFTS INTO THE SOUTHERN APPALACHIANS LATE
TONIGHT...MOISTURE ALOFT WILL ALSO BEGIN TO DEPART OFF TO THE EAST
AND CEILINGS ARE EXPECTED TO LIFT AND SCATTER IN THE HOURS
APPROACHING DAYBREAK. HIGH PRESSURE RIDGE THEN BUILDS INTO THE
REGION TODAY WITH BROAD SUBSIDENCE. WILL SEE SKIES BECOME
MOSTLY CLEAR. LIGHT AND VARIABLE WINDS LATE TONIGHT WILL SHIFT TO
W/SW AND INCREASE TO NEAR 10KTS BY THIS AFTERNOON.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...CP/JAS
SHORT TERM...CP
LONG TERM....RYAN
AVIATION...SMF
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1140 PM MST TUE JAN 15 2013
.SHORT TERM...(THIS AFTERNOON THROUGH WEDNESDAY)
ISSUED AT 212 PM MST TUE JAN 15 2013
LATEST WV IMAGERY AND RUC H5 ANALYSIS SHOWS LONGWAVE TROUGH EXTENDING
FROM THE GREAT LAKES ACROSS CENTRAL KANSAS INTO NORTHERN MEXICO. CWA
IS CURRENTLY ON SUBSIDENT SIDE OF TROUGH AXIS UNDER SHORTWAVE
RIDGING. A WEAK SHORTWAVE TROUGH OVER MONTANA IS CURRENTLY MOVING
THROUGH N/NW FLOW ALONG THE BACK SIDE OF THE TROUGH.
THIS FEATURE IS EXPECTED TO SPLIT WITH A WEAK PIECE OF ENERGY MOVING
SOUTH ACROSS EASTERN COLORADO TONIGHT. WITH MAIN H3 JET AXIS WELL
NORTH OF THE CWA...I AM ONLY ANTICIPATING WEAK FORCING. MODEL
SOUNDINGS INDICATE A SATURATED LEVEL BETWEEN 800-600MB. WITH WEAK
FORCING IN THE WEST...AND VERY LITTLE IN THE WAY OF QPF SHOWN BY
AVAILABLE GUIDANCE I LIMITED SLIGHT CHANCE POPS TO WESTERN CWA THIS
EVENING AND OVERNIGHT...AND SCATTERED FLURRIES ELSEWHERE. EVEN IN
THE WEST WHERE MEASURABLE SNOW IS POSSIBLE I WOULD ONLY ANTICIPATE
A FEW TENTHS OF AN INCH WITH THIS SYSTEM.
SUBSIDENCE ALONG AND A MUCH DRIER AIR MASS WILL SPREAD EAST
WEDNESDAY WITH W/NW FLOW DEVELOPING. AIR MASS HAS ALREADY MODIFIED
WITH SHORTWAVE RIDGING THIS AFTERNOON AND SHOULD CONTINUE TO MODIFY
WED WITH HIGHS IN THE 40S/NEAR 50. THE SNOW PACK IN THE WEST AND NE
WILL STILL KEEP HIGHS SLIGHTLY COOLER...HOWEVER WITH WESTERLY WINDS
WE SHOULD STILL SEE HIGHS AROUND 40F AT THE COLDEST. A CONCERN FOR
WED WILL BE WINDS...WITH BREEZY TO WINDY CONDITIONS ANTICIPATED. I
AM LESS CONFIDENT HOW WINDY IT WILL BE WITH LIMITED MIXING HEIGHTS
BASED ON SOUNDING ANALYSIS. IF WE MIX MUCH HIGHER THAN CURRENT
SOUNDINGS SUGGEST...THEN WE COULD SEE ADVISORY CRITERIA MET...
ESPECIALLY IF WE USE THE NAM WINDS ALOFT. FOR NOW...I LIMITED WINDS
TO JUST UNDER ADVISORY CRITERIA WED AFTERNOON.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 1135 PM MST TUE JAN 15 2013
UPPER PATTERN ACROSS THE CONUS THIS PERIOD WILL FEATURE A RIDGE IN
THE WEST AND A TROUGH IN THE EAST. LOCAL AREA WILL FALL MAINLY
UNDER THE INFLUENCE OF THE RIDGE AND NO PRECIPITATION IS FORECAST.
AS FOR TEMPERATURES...MAIN CONCERN WILL BE FOR A BACK DOOR COLD
FRONT EARLY SUNDAY FOLLOWED BY A STRONGER COLD FRONT SUNDAY NIGHT
AND MONDAY. MONDAY WILL BE THE COLDEST DAY...BUT IT APPEARS COLD
SNAP WILL BE SHORT LIVED AS MODELS SHOW WARMING ON TUESDAY AND
WEDNESDAY AS COLD AIR LIFTS OUT TO THE NORTH UNDER SHORTWAVE
RIDGING.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1001 PM MST TUE JAN 15 2013
KGLD RADAR GETTING RETURNS ON LIGHT SNOW/FLURRIES ACROSS THE AREA
TONIGHT. HOWEVER ONLY ISOLATED REPORTS OF SNOW REACHING THE
SURFACE. THIS AREA OF LIGHT SNOW IS MOVING SOUTH QUICKLY AND
EXPECT DECREASING CLOUDS BY EARLY WEDNESDAY MORNING. CURRENT
METARS ARE VFR AND THE LATEST TREND IS FOR INCREASING CLOUD BASES.
THERE IS POTENTIAL FOR BREEZY TO WINDY CONDITIONS ACROSS THE AREA
BUT MIXING HEIGHTS ARE BELOW 800MB. WINDS WILL DECREASE BY 00Z
THURSDAY.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...024
AVIATION...032
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1130 PM CST TUE JAN 15 2013
...UPDATE TO AVIATION...
.DISCUSSION...
20Z WATER VAPOR SHOWS THE TROUGH AXIS OVERHEAD WITH THE UPPER
FLOW BEGINNING TO SPLIT WITH ENERGY BEING LEFT BEHIND OVER THE
SOUTHERN HIGH PLAINS. AT THE SURFACE...THE RIDGE AXIS STRETCHED
FROM THE TX PANHANDLE UP TO CHICAGO. THERE IS A MAXIMUM IN SURFACE
DEWPOINTS IMMEDIATELY DOWNSTREAM OF THE SNOW PACK IN SOUTHERN NEB.
WITH DAYTIME HEATING STEEPENING UP LOW LEVEL LAPSE RATES WITH
ADDED BOUNDARY LAYER MOISTURE...A CU FIELD HAS FORMED OVER NORTH
CENTRAL KS. WOULD EXPECT THESE CLOUDS TO DIMINISH WITH THE LOSS OF
DAYTIME HEATING AND THE 19Z RAP AND 18Z NAM SEEM TO SUPPORT THIS
IDEA...SO THINK SKIES SHOULD BECOME MOSTLY CLEAR OVERNIGHT.
FOR TONIGHT AND WEDNESDAY...THE FORECAST AREA IS EXPECTED TO BE
BETWEEN THE SPLITTING PATTERN WITH A CLOSED LOW REMAINING OVER THE
SOUTHERN PLAINS AND STRONG NORTHWEST FLOW REMAINING NORTH OVER THE
DAKOTAS AND UPPER MIDWEST. THEREFORE THERE IS EXPECTED TO BE LITTLE
OR NOW LARGE SCALE FORCING AFFECTING THE FORECAST AREA. WITH THIS
AND A DRY AIRMASS TO START OUT WITH...THE FORECAST REMAINS DRY.
THERE WILL BE A TROUGH AXIS/WIND SHIFT MOVE THROUGH THE AREA ON
WEDNESDAY. MODELS DO NOT SHOW ANY COLD AIR BEHIND THIS BOUNDARY AND
IN FACT HAVE WARM AIR ADVECTING IN FROM THE WEST WITH A DOWNSLOPE
WIND. THEREFORE HAVE CONTINUED WITH HIGHS GENERALLY AROUND 50. THERE
IS INDICATIONS FROM THE NAM AND GFS OF SOME SATURATED AIR BEHIND THE
FRONT WHICH COULD BE HELPED BY MELTING SNOW IN NEB...SO THINK SKIES
COULD BECOME PARTLY CLOUDY AS WINDS SHIFT TO THE WEST AND NORTHWEST.
THE PRESSURE GRADIENT SHOULD INCREASE OVERNIGHT AS THE SURFACE
TROUGH APPROACHES THE AREA. THIS SHOULD CAUSE WINDS TO GRADUALLY
INCREASE OVERNIGHT HELPING TO KEEP MIN TEMPS SEVERAL DEGREES WARMER
THAN THIS MORNING AND HAVE MIN TEMPS IN THE UPPER TEENS.
WOLTERS
CLEAR SKIES TO BE THE RULE THROUGH EARLY NEXT WEEK WITH NORTHWEST
FLOW ALOFT KEEPING MOISTURE RETURN IN CHECK AND MEAGER FORCING
MECHANISMS FOR CLOUDS LET ALONE PRECIPITATION. WEAK SURFACE HIGH
BUILDS IN THURSDAY WITH ACTUALLY A BIT OF WARMING AROUND
850MB...BUT THE LIMITED MIXING SHOULD KEEP HIGHS A FEW DEGREES
COOLER THAN WEDNESDAY. FRIDAY STILL LOOKING THE BE THE WARMEST DAY
WITH WEST TO SOUTHWEST WINDS DEVELOPING AHEAD OF A WAVE IN THE GREAT
LAKES. SATURDAY WILL SEE THE FIRST OF TWO COLD FRONTS MOVE IN DURING
THE DAY. MID TO LATE DAY COLD AIR ADVECTION SHOULD KEEP HIGHS IN THE
40S...WITH A MORE POTENT SHOT COMING IN THE SUNDAY NIGHT INTO MONDAY
TIME FRAME. THERE HAS BEEN SOME VACILLATION IN THE MODELS WITH HOW
FAR SOUTHWEST THE COLD AIR WILL REACH AND SPECIFIC TIMING OF THE
COLD AIR REMAINS UNCERTAIN. ALSO...THERE IS GOOD AGREEMENT WITH THE
UPPER PATTERN BREAKING DOWN TO A MORE ZONAL CHARACTER AS THE EASTERN
PACIFIC RIDGE BREAKS DOWN LEADING TO THE COLDEST AIR/S RESIDENCE
TIME IN THE CENTRAL PLAINS LIMITED. MONDAYS MAXES IN THE UPPER TEENS
TO MID 20S SEEM REASONABLE AT THIS POINT WITH MODIFICATION FOR
TUESDAY.
65
&&
.AVIATION...
VFR CONDITIONS WITH LIGHT WINDS EXPECTED THROUGH REMAINDER OF THE
FORECAST PERIOD. MODELS INDICATING A NEAR-SATURATED LEVEL AROUND
3000 FEET MID DAY ON WED...BUT GIVEN ITS SHALLOW NATURE ITS
POSSIBLE THAT IT WILL REMAIN SCT OR SIMPLY MIX OUT. WILL MENTION
SCT030 FOR THIS FORECAST AND INCREASE COVERAGE IN LATER ISSUANCES
SHOULD IT BE WARRANTED.
JL
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1029 PM MST TUE JAN 15 2013
.SHORT TERM...(THIS AFTERNOON THROUGH WEDNESDAY)
ISSUED AT 212 PM MST TUE JAN 15 2013
LATEST WV IMAGERY AND RUC H5 ANALYSIS SHOWS LONGWAVE TROUGH EXTENDING
FROM THE GREAT LAKES ACROSS CENTRAL KANSAS INTO NORTHERN MEXICO. CWA
IS CURRENTLY ON SUBSIDENT SIDE OF TROUGH AXIS UNDER SHORTWAVE
RIDGING. A WEAK SHORTWAVE TROUGH OVER MONTANA IS CURRENTLY MOVING
THROUGH N/NW FLOW ALONG THE BACK SIDE OF THE TROUGH.
THIS FEATURE IS EXPECTED TO SPLIT WITH A WEAK PIECE OF ENERGY MOVING
SOUTH ACROSS EASTERN COLORADO TONIGHT. WITH MAIN H3 JET AXIS WELL
NORTH OF THE CWA...I AM ONLY ANTICIPATING WEAK FORCING. MODEL
SOUNDINGS INDICATE A SATURATED LEVEL BETWEEN 800-600MB. WITH WEAK
FORCING IN THE WEST...AND VERY LITTLE IN THE WAY OF QPF SHOWN BY
AVAILABLE GUIDANCE I LIMITED SLIGHT CHANCE POPS TO WESTERN CWA THIS
EVENING AND OVERNIGHT...AND SCATTERED FLURRIES ELSEWHERE. EVEN IN
THE WEST WHERE MEASURABLE SNOW IS POSSIBLE I WOULD ONLY ANTICIPATE
A FEW TENTHS OF AN INCH WITH THIS SYSTEM.
SUBSIDENCE ALONG AND A MUCH DRIER AIR MASS WILL SPREAD EAST
WEDNESDAY WITH W/NW FLOW DEVELOPING. AIR MASS HAS ALREADY MODIFIED
WITH SHORTWAVE RIDGING THIS AFTERNOON AND SHOULD CONTINUE TO MODIFY
WED WITH HIGHS IN THE 40S/NEAR 50. THE SNOW PACK IN THE WEST AND NE
WILL STILL KEEP HIGHS SLIGHTLY COOLER...HOWEVER WITH WESTERLY WINDS
WE SHOULD STILL SEE HIGHS AROUND 40F AT THE COLDEST. A CONCERN FOR
WED WILL BE WINDS...WITH BREEZY TO WINDY CONDITIONS ANTICIPATED. I
AM LESS CONFIDENT HOW WINDY IT WILL BE WITH LIMITED MIXING HEIGHTS
BASED ON SOUNDING ANALYSIS. IF WE MIX MUCH HIGHER THAN CURRENT
SOUNDINGS SUGGEST...THEN WE COULD SEE ADVISORY CRITERIA MET...
ESPECIALLY IF WE USE THE NAM WINDS ALOFT. FOR NOW...I LIMITED WINDS
TO JUST UNDER ADVISORY CRITERIA WED AFTERNOON.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 212 PM MST TUE JAN 15 2013
FORECAST PROBLEMS WILL BE THE AMOUNT OF WARMUP BEFORE THE NEXT VERY
COLD AIR MASS ARRIVES AND HOW COLD WILL THAT AIR MASS ALONG WITH
WHEN IT ARRIVES. SATELLITE SHOWING AN AMPLIFIED FLOW STARTING WITH
A BROAD...DEEP AND COMPLICATED UPPER TROUGH OVER THE WESTERN HALF OF
THE PACIFIC WHICH IS MAINTAINING/AMPLIFYING AN UPPER RIDGE NEAR THE
WEST COAST OF NORTH AMERICA. THIS TRANSITIONS TO A TROUGH OVER THE
CENTER OF THE COUNTRY WHICH HAS/CONTINUES TO SPLIT. WARMER AIR MASS
STARTING TO WORK ITS WAY INTO THE REGION.
AT JET LEVEL...THE MODELS INITIALIZED FINE WITH THE ECMWF SLIGHTLY
WORSE THAN THE OTHERS. SATELLITE AND UPPER AIR ANALYSIS SHOW THE
MODELS HAVE INITIALIZED WELL AT MID LEVELS. HOWEVER WOULD HAVE TO
SLIGHTLY FAVOR THE UKMET/CANADIAN OVER THE NAM/ECMWF. AT THE
SURFACE THE SREF WAS DOING A LITTLE BETTER THAN THE ECMWF. THE UKMET
WAS DOING A LITTLE BETTER THAN THE ECMWF AND GFS ON THE LOW LEVEL
THERMAL FIELD.
WEDNESDAY NIGHT/THURSDAY...MAIN STORM TRACK REMAINS WELL NORTH OF
THE AREA AND UNDER SUBSIDENCE FROM THE JET. FLOW ALOFT IS MORE
NORTHWEST WITH LITTLE TO NO CLOUD COVER EXPECTED AT THIS TIME.
WINDS MAY DROP OFF LATE IN THE NIGHT MAINLY IN THE WEST. SURFACE
RIDGE MOVES THROUGH EARLY IN THE DAY ON THURSDAY WITH WINDS SHIFTING
MORE TOWARD THE SOUTH IN THE AFTERNOON. ADJUSTED TEMPERATURES UP A
LITTLE.
THURSDAY NIGHT/FRIDAY...STORM TRACK STILL NORTH OF THE AREA WITH
WEST TO NORTHWEST FLOW ALOFT. THERE MAY BE A LITTLE MORE CLOUD
COVER DURING THE NIGHT AS A WEAK SYSTEM MOVES THROUGH IN THE FLOW
BUT AGAIN LITTLE TO NO CLOUD COVER EXPECTED. DOWNSLOPE COMPONENT IS
MUCH BETTER ON THE WINDS AND ALL MODELS ARE SIMILAR IN THEIR INCREASE
IN THE 850 MB TEMPERATURES. ALSO WOULD EXPECT THE WARM AIR ADVECTION
AND DOWNSLOPE WILL BE BETTER THAN DEPICTED SINCE THIS WILL BE AHEAD
OF THE INITIAL PUSH OF COLDER THAT WILL COME IN ON SATURDAY. SO FELT
COMFORTABLE IN WARMING UP MAXES FROM THE CURRENT PACKAGE. IT IS
POSSIBLE THAT ADDITIONAL RAISING OF THE MAXES WILL BE POSSIBLE.
FRIDAY NIGHT THROUGH TUESDAY...BIG CHANGE IN THE WEATHER...TO MUCH
COLDER TEMPERATURES THIS WEEKEND INTO THE BEGINNING OF NEXT WEEK...
STILL LOOKS ON TRACK. THERE ARE STILL DIFFERENCES IN THE MODELS BUT
THEY ARE MUCH CLOSER THAN YESTERDAY WHICH INCREASES CONFIDENCE ON
THE MAGNITUDE AND ESPECIALLY THE TIMING. SATURDAY LOOKS TO BE VERY
TRICKY. THE INITIAL PUSH IS COMING IN A LITTLE FASTER AND LOOKS
LIKE IT MAY ARRIVE LATE MORNING INTO EARLY AFTERNOON ESPECIALLY IN
THE NORTHEAST HALF OF THE AREA. SO THERE LOOKS TO BE A GOOD GRADIENT
ACROSS MY AREA WHICH WILL NEED TO BE RESOLVED AS WE GET MUCH CLOSER
TO THE DAY. AT THIS TIME TOOK WHAT WAS GIVEN TO ME BY THE CRH_INIT
AND NUDGED DOWN A LITTLE AS I BLENDED WITH NEIGHBORS.
FIRST PUSH OF THE COLD AIR LOOKS TO BE WELL ENTRENCHED BY 12Z
SUNDAY. MODELS WANT TO SCOUR OUT THE COLD AIR DURING THE DAY AS WINDS
SHIFT TO THE WEST BEFORE THE COLDEST AIR ARRIVES SUNDAY NIGHT. NOT
ENTIRELY SOLD ON THAT. SO AFTER COLLABORATION WITH NEIGHBORS DID
LOWER MAXES FROM WHAT WAS GIVEN BY THE INIT. VERY COLD AIR TO
ARRIVE SUNDAY NIGHT INTO MONDAY PER MODEL CONSENSUS. AFTER
COLLABORATION FELT VERY COMFORTABLE IN LOWERING MAXES SIGNIFICANTLY.
WHEN THE COLD AIR COMES IN SUNDAY NIGHT AND MONDAY FLURRIES WILL BE
POSSIBLE. THEN MODELS WANT TO REALLY SCOUR OUT THE COLD AIR ON
TUESDAY AND AGAIN NOT SOLD ON THAT. HOWEVER...THE INIT GAVE ME COOLER
TEMPERATURES THAN WHAT THE MODEL 850 TEMPERATURES SAY. SO AGREED WITH
SURROUNDING OFFICES IN LEAVING THOSE TEMPERATURES ALONE FOR NOW.
THANKS TO ALL FOR THE COLLABORATION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1001 PM MST TUE JAN 15 2013
KGLD RADAR GETTING RETURNS ON LIGHT SNOW/FLURRIES ACROSS THE AREA
TONIGHT. HOWEVER ONLY ISOLATED REPORTS OF SNOW REACHING THE
SURFACE. THIS AREA OF LIGHT SNOW IS MOVING SOUTH QUICKLY AND
EXPECT DECREASING CLOUDS BY EARLY WEDNESDAY MORNING. CURRENT
METARS ARE VFR AND THE LATEST TREND IS FOR INCREASING CLOUD BASES.
THERE IS POTENTIAL FOR BREEZY TO WINDY CONDITIONS ACROSS THE AREA
BUT MIXING HEIGHTS ARE BELOW 800MB. WINDS WILL DECREASE BY 00Z
THURSDAY.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...BULLER
AVIATION...032
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
358 PM CST WED JAN 16 2013
.DISCUSSION...
TONIGHT AND THURSDAY...LOW PRES TRIPLE POINT CENTER TRAVERSING ESE
THRU WRN WI WITH THE CDFNT SNAKING EWD THRU KMSP TWD KABR...AND
THIS CDFNT WILL CONTINUE TO PRES SE THRU THE REST OF THE EVE.
BATCH OF -SN THAT PUSHED THROUGH MAINLY WRN AND SRN PORTIONS OF
THE TWIN CITIES REGION HAS SHIFTED OFF TO THE SE SO AM NOT
EXPECTING MUCH MORE OF ANY ACCUMULATING OR VISIBILITY-HAMPERING
SNOWFALL. THE SNOW WILL COME TO AN END OVER THE MPX CWFA BY LATE
EVENING THEN COLDER HIGH PRES WILL SLIDE SE LATE TNGT THRU TMRW.
SKIES WILL PARTIALLY CLEAR OUT...BUT THE MAIN IMPACT WILL BE
STRONGER CAA. AFTER HIGHS THAT RANGED THRU THE 30S THIS AFTN...THE
POST-FRONTAL CAA WILL FORCE LOWS THAT WILL SPAN FROM 10 DEGREES
ABOVE ZERO TO 10 DEGREES BELOW ZERO TONIGHT. THIS WILL THEN BE
FOLLOWED BY HIGHS FROM AROUND 10 TO THE LOWER 20S FOR THU.
THURSDAY NIGHT THROUGH SATURDAY...THE AREA OF HIGH PRES WILL ONLY
BE SHORT-LIVED AS IT SHIFTS OFF TO THE SE THU NIGHT INTO FRI WHILE
A WMFNT NUDGES IN FROM THE W. THIS WILL RESULT IN NOT ONLY A
WARMING TREND FRI INTO FRI NIGHT BUT ALSO THE POTENTIAL FOR SOME
SNOW SHOWERS OR LIGHT SNOW FOR MAINLY NRN AND ERN PORTIONS OF THE
MPX CWFA THU NIGHT THRU SAT AS THE FNT WILL SLOWLY LIFT OUT AND
GIVE WAY TO SEVERAL UPPER LEVEL DISTURBANCES PLUS A TRAILING CDFNT
FOR SAT. POPS ARE NO HIGHER THAN CHC RANGE AND ACCUMULATIONS...IF
ANY...WILL BE MINOR. AS FOR TEMPS...THE SIGNIFICANT WARM-UP FOR
FRI WILL BRING HIGHS AROUND 40 NEAR THE IA BORDER WITH 30S
ELSEWHERE THROUGHOUT THE CWFA. HOWEVER...THE MAIN CDFNT WHICH WILL
BE THE FOCUS FOR A SIGNIFICANT ARCTIC CHILL WILL PUSH THROUGH LATE
SAT SO ALTHOUGH HIGHS WILL DROP OFF ONLY TO THE LOW 20S TO LOW
30S... CAA WILL ABSOLUTELY COMMENCE BY LATE DAY SAT. WINDS WILL
ALSO BE ON THE INCRS DURG THE DAY SAT WITH A TIGHT POST-FRONTAL
PRES GRADIENT AND STRONG JETTING. WIND CHILL VALUES BY LATE DAY
SATURDAY WILL BE IN THE SINGLE DIGITS IN FAR SRN AND ERN
PORTIONS... WHILE NRN AND WRN PORTIONS WILL DROP TO AS LOW AS 20
DEGREES BELOW ZERO.
SATURDAY NIGHT THROUGH TUESDAY...THE ARCTIC BLAST WILL COMMENCE
OVER THE REGION STARTING SAT NIGHT AS A 1040-1050MB HIGH PRES
CENTER FROM NRN CANADA WILL DROP INTO THE NORTH-CENTRAL CONUS. IT
WILL SETTLE OVER THE AREA MON INTO MON NIGHT...MAKING THESE TWO
PERIODS THE COLDEST THIS REGION HAS SEEN IN SOME TIME. BREEZY
CONDITIONS WILL ALSO STILL BE PRESENT WITH THE COLD AIR...SO
COMBINING HIGHS RANGING FROM ZERO TO 10 BELOW ZERO ON MON FOLLOWED
BY LOWS MON NIGHT BETWEEN 10 AND 20 BELOW ZERO WILL MAKE FOR WIND
CHILL VALUES BETWEEN 20 AND 35 DEGREES BELOW ZERO. IT/S LOOKING
MORE AND MORE LIKELY THAT WIND CHILL ADVISORIES/WARNINGS WILL BE
NEEDED. AFTER TEMPS BOTTOM OUT MON NIGHT...THE HIGH PRES CENTER
WILL PUSH OFF TO THE E...ALLOWING A MORE SOUTHERLY FLOW. THIS
WILL ALLOW HIGHS ON TUE TO CLIMB INTO THE SINGLE DIGITS ABOVE
ZERO.
&&
.AVIATION.../00Z TAF ISSUANCE/
WITH SNOW RAPIDLY MOVING EAST ACROSS MN...WENT CONSIDERABLY MORE
PESSIMISTIC WITH THE 18Z TAFS. THESE TAFS BASED HEAVILY ON THE
RAP/HRRR...WHICH HAVE BOTH HANDLED THIS SNOW QUITE WELL THIS
MORNING. SEEING WIDESPREAD 1-3SM VIS SNOW ACROSS WRN MN RIGHT
NOW...WITH AN OCCASIONAL VIS UNDER 1SM. WITH SNOW BEING REPORTED
FROM MADISON TO LONG PRAIRIE...ALL TERMINALS LOOK TO GET IN THE
SNOW...WITH MSP/AXN BEING IN THE HEART OF THE BAND AND STC/RNH/EAU
BEING ON THE NORTH SIDE OF IT AND RWF BEING ON THE SOUTH SIDE. FOR
AXN/MSP...WENT WITH OUTRIGHT IFR VIS IN SNOW...WITH OUTER
LOCATIONS GETTING A TEMPO IFR TREATMENT. WILL BE A FAIRLY
PROGRESSIVE BAND OF SNOW...WITH MOST TERMINALS DONE WITH IT BY
00Z. IN ITS WAKE...EXPECT A BRIEF PERIOD OF SKC-FEW SKY
CONDS...BUT THE MPX AREA WILL BE REMAINING WITHIN A FRONTAL ZONE
ALOFT...WITH CLOUDS RETURNING BY THE END OF THE NIGHT. BASED ON
THE NAM/RAP...EXPECT ANOTHER ROUND OF MVFR CIGS TO MOVE OUT OF THE
DAKOTAS TONIGHT. CONFIDENCE NOT AS HIGH WITH THIS OCCURRING...BUT
WENT WITH THE STRATUS IDEA BASED ON CONTINUED COOLING NOTED ON
NAM BUFKIT SOUNDINGS OUT WEST. FOR WINDS...COLD FRONT IS JUST NOW
SLIPPING THROUGH RWF/MSP/EAU. WILL SEE WINDS BACK ALL THE WAY OVER
TO THE N IN WRN MN AND NW IN ERN MN/WRN WI. NOT EXPECTING AND HAVE
NOT SEEN MUCH IN THE WAY OF GUSTS...BUT SHOULD KEEP PERSISTENT
SUSTAINED SPEEDS IN THE 10-15 KT RANGE THROUGH THE REST OF THE DAY.
KMSP...SNOW IS RAPIDLY APPROACHING FROM THE WEST AND SHOULD BE AT
THE FIELD WITHIN THE FIRST HOUR. SOLID IFR OBS HAVE BEEN SEEN WITH
THIS BATCH OF SNOW ALL MORNING AND BASED ON THAT...SENT THE VIS
THAT DIRECTION FOR MSP. HRRR HAS CONTINUED TO HANDEL THIS ACTIVITY
WELL...AND FOLLOWED IT AND THE RAP CLOSELY FOR TIMING SNOW IN/OUT.
LOOKING AT NAM SOUNDINGS...MAY SEE A BRIEF MVFR CIG OR TWO
THURSDAY MORNING...BUT OTHERWISE...VFR CONDITIONS WILL DOMINATE
THIS TAF PERIOD ONCE THE AFTERNOON SNOW MOVES OUT.
/OUTLOOK FOR KMSP/
FRI...VFR. CHC OF -SN AND MVFR VIS/CIG IN MORNING. WIND SW 5-15
KTS.
SAT...MVFR CIGS LIKELY. AFTERNOON -SN POSSIBLE. W WIND 5 KTS BECOMING NW
15-20 KTS WITH GUSTS TO 30 KTS.
SUN...CHANCE OF -SN WITH MVFR OR LOWER CIG/VIS. WINDS W 5-10 KTS
BECOMING NW 15-20 KTS LATE.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
JPC/MPG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1234 PM CST WED JAN 16 2013
.UPDATE...
18Z AVIATION DISCUSSION ADDED BELOW.
JUST GOT THROUGH WITH SOME SWEEPING UPDATES TO THE GRIDS...WITH
THE BIG ONE TO DRASTICALLY INCREASE POPS FOR THIS
AFTERNOON...WITH LIKELY POPS NOW INDICATED FROM WEST CENTRAL MN
INTO THE TWIN CITIES. RAP H85/H7 FGEN LOCKING ON TO BAND OF
MODERATE SNOW MOVING OUT OF SE NODAK NOW...WITH THE HRRR
REFLECTIVITY FORECASTS THIS MORNING PICKING UP ON THE AREA AS
WELL. THE RAP TAKES THIS AREA OF FGEN FROM THE AXN AREA DOWN
TOWARD LA CROSSE BY THIS EVENING...WITH HRRR REFLECTIVITY FORECAST
FOLLOWING THIS AREA OF FORCING PRETTY MUCH LOCK AND STEP. AS A
RESULT...BOOSTED THE POPS QUITE A BIT...TAKING THE LEAD OF THE
HRRR/RAP FOR THE REST OF TODAY. NOT EXPECTING MUCH SNOWFALL WITH
THIS...WITH A HALF INCH OF SNOW ACCUMS CURRENTLY INDICATED IN THE
GRIDS. TIMING WISE...THIS LOOKS TO MOVE INTO THE TWIN CITIES JUST
IN TIME FOR THE EVENING COMMUTE...SO WE MAY END UP GOING 2 FOR 2
ON WEATHER SLOWED COMMUTES TODAY.
OTHER THAN POP/WX...INCREASED DEWPS SEVERAL DEGREES OUT AHEAD OF
THE FRONT...WHERE THEY HAVE INCREASED INTO THE 30S THIS
MORNING...AND SPED UP THE TEMP DROP IN THE NW CWA SOME THIS
AFTERNOON...AS WE ARE STARTING TO SEE SOME PRETTY GOOD CAA ACROSS
THE RED RIVER VALLEY...WHERE THE GRAND FORKS AREA IS ALREADY BACK
DOWN INTO THE SINGLE DIGITS.
&&
.PREV DISCUSSION...
/ISSUED 413 AM CST WED JAN 16 2013/
OVERVIEW...NO MAJOR CHANGES TO THE PREVIOUS FORECAST. BACKED OFF
ON THE POPS TODAY IN EASTERN MN AND WESTERN WI...TRAILING WAVE
BEHIND THE COLD FRONT JUST DOESNT LOOK OVERLY IMPRESSIVE.
INCREASED POPS A BIT WITH FRIDAY`S CLIPPER SYSTEM...AS THERE IS
PRETTY GOOD CONTINUITY WITH THAT SYSTEM OVER THE LAST COUPLE MODEL
RUNS. FINALLY...ONLY SLIGHT ADJUSTMENTS TO TEMPERATURES AND WIND
SPEEDS SUNDAY THROUGH MONDAY WITH THE BLAST OF ARCTIC AIR...BUT
ENDED UP WITH MORE LOCATIONS WITH APPARENT TEMPERATURES BETWEEN 30
AND 40 BELOW ZERO...EVEN AS EARLY AS SUNDAY NIGHT WHEN THE WIND
LOOKS TO BE BLUSTERY.
COLD FRONT AND SURFACE TROUGH MAKING STEADY PROGRESS ACROSS
MINNESOTA THIS MORNING. INTERESTING TEMPERATURE TREND THIS MORNING IN
WESTERN MN AND THE DAKOTAS. FOR EXAMPLE...THE TEMPERATURE AT
KGFK HAS GONE FROM 21...23...29...34...37...27...24...19 OVER THE
LAST 8 HOURS ENDING AT 4 AM. FARGO IS ACTUALLY REPORTING LIGHT
RAIN THIS MORNING AS WELL. COLDER AIR IS CERTAINLY ON THE WAY
BEHIND THIS CLIPPER SYSTEM AND IT SHOULD LIMIT TEMPS IN NORTHERN
PORTIONS OF THE FORECAST AREA TODAY. TRIED TO INCLUDE A NON-
DIURNAL TEMPERATURE TREND OVER THE NEXT 24 HOURS. GIVEN THE SPEED
OF THE COLD FRONT AND POSITION OF STRONGEST RADAR RETURNS IN
RELATION TO THIS FRONT...MOST OF MINNESOTA MIGHT ONLY END UP WITH
A FEW FLURRIES OR SPRINKLES TODAY. THE TRAILING WAVE IS SUBTLE AT
THIS POINT AND IT`S DIFFICULT EVEN TO PICK OUT IN WATER VAPOR.
THIS SHOULD VIRTUALLY BE A NON ISSUE IN TERMS OF PRECIP FOR
EASTERN MN AND WESTERN WI THIS AFTERNOON. REDUCED POPS...BUT DID
NOT GO COMPLETELY DRY...AND STILL KEEP 40%-50% GOING IN WESTERN
MN. TEMP FORECAST TODAY IS CHALLENGING...BUT EVEN WITH CLOUD COVER
WE MIGHT BE TOO COOL IN SPOTS WHERE WE HAVE MID 30S GOING GIVEN
THE QUICK WARM FRONTAL PASSAGE TODAY. MIGHT SEE A LOT OF UPPER 30S
AND POSSIBLY EVEN A COUPLE 40S.
THE 16.00Z GFS HAS JOGGED NORTH A BIT WITH FRIDAY`S CLIPPER
SYSTEM...THE ECMWF HAS COME FARTHER SOUTH BUT IS WEAKER AND
BROADER WITH THE SURFACE REFLECTION. STILL WORTH A MENTION OF SNOW
ON FRIDAY GIVEN THIS SIGNAL HAS BEEN SHOWING UP FOR A COUPLE DAYS
NOW. LIGHT SNOW LOOKS MORE PROMISING IN NORTHERN MN AND FAR
NORTHERN WI. THIS SYSTEM ACTUALLY HAS A TRAILING SURFACE LOW THAT
LINGERS INTO SATURDAY. THIS MIGHT MEAN MORE CLOUD COVER/PERHAPS
FLURRIES THAN WHAT IS CURRENTLY IN THE FORECAST.
WE`VE BEEN ADVERTISING THE STRONG ARCTIC AIR MASS FOR SUNDAY NIGHT
THROUGH MONDAY NIGHT...FOR AT LEAST TWO DAYS NOW. NOT MUCH CHANGE
WITH LAST NIGHTS MODEL RUNS...AS THE ARCTIC BOUNDARY COMES IN
QUICK AND THE AIR MASS ALREADY BEGINS TO MODERATE BY TUESDAY.
HOWEVER...THE LATEST FORECAST WIND CHILLS ARE IMPRESSIVELY COLD
EVEN SUNDAY NIGHT WITH HIGH BUILDING IN ACROSS THE DAKOTAS AND
REMNANT SURFACE TROUGH HANGING BACK OVER THE WARMER GREAT LAKES IN
THE WAKE OF THE CLIPPER SYSTEM. THERE SHOULD BE A STRONG PUSH OF
COLD AIR WITH THE ARCTIC BOUNDARY AND THE PRESSURE GRADIENT
SUGGESTS BLUSTERY WINDS AS COLD AIR ADVECTION KICKS IN GEAR.
MONDAY HAS A LOOK OF ONE THOSE CLASSICALLY COLD MN/WI DAYS YOU MAY
REMEMBER FROM YOUR CHILDHOOD...AND AT THE VERY LEAST SINCE 2009.
BREEZY NORTHERLY WINDS AND HIGH TEMPERATURES BETWEEN -2 AND -12
WITH SUNNY SKIES. THE LACK OF SNOW COVER IN PORTIONS OF WEST
CENTRAL WI AND SOUTHERN MN WILL KEEP TEMPS WARMER BY A FEW
DEGREES...BUT NONETHELESS...THIS WILL BE SOME OF THE COLDEST AIR
WE`VE SEEN IN THE LAST 3-4 YEARS. WE SHOULD SEE WIND CHILLS
BETWEEN 25 AND 40 BELOW ACROSS MUCH OF THE AREA. WIND CHILL
ADVISORY/WARNINGS WILL BE NEEDED SUNDAY/TUESDAY.
&&
.AVIATION.../00Z TAF ISSUANCE/
WITH SNOW RAPIDLY MOVING EAST ACROSS MN...WENT CONSIDERABLY MORE
PESSIMISTIC WITH THE 18Z TAFS. THESE TAFS BASED HEAVILY ON THE
RAP/HRRR...WHICH HAVE BOTH HANDLED THIS SNOW QUITE WELL THIS
MORNING. SEEING WIDESPREAD 1-3SM VIS SNOW ACROSS WRN MN RIGHT
NOW...WITH AN OCCASIONAL VIS UNDER 1SM. WITH SNOW BEING REPORTED
FROM MADISON TO LONG PRAIRIE...ALL TERMINALS LOOK TO GET IN THE
SNOW...WITH MSP/AXN BEING IN THE HEART OF THE BAND AND STC/RNH/EAU
BEING ON THE NORTH SIDE OF IT AND RWF BEING ON THE SOUTH SIDE. FOR
AXN/MSP...WENT WITH OUTRIGHT IFR VIS IN SNOW...WITH OUTER
LOCATIONS GETTING A TEMPO IFR TREATMENT. WILL BE A FAIRLY
PROGRESSIVE BAND OF SNOW...WITH MOST TERMINALS DONE WITH IT BY
00Z. IN ITS WAKE...EXPECT A BRIEF PERIOD OF SKC-FEW SKY
CONDS...BUT THE MPX AREA WILL BE REMAINING WITHIN A FRONTAL ZONE
ALOFT...WITH CLOUDS RETURNING BY THE END OF THE NIGHT. BASED ON
THE NAM/RAP...EXPECT ANOTHER ROUND OF MVFR CIGS TO MOVE OUT OF THE
DAKOTAS TONIGHT. CONFIDENCE NOT AS HIGH WITH THIS OCCURRING...BUT
WENT WITH THE STRATUS IDEA BASED ON CONTINUED COOLING NOTED ON
NAM BUFKIT SOUNDINGS OUT WEST. FOR WINDS...COLD FRONT IS JUST NOW
SLIPPING THROUGH RWF/MSP/EAU. WILL SEE WINDS BACK ALL THE WAY OVER
TO THE N IN WRN MN AND NW IN ERN MN/WRN WI. NOT EXPECTING AND HAVE
NOT SEEN MUCH IN THE WAY OF GUSTS...BUT SHOULD KEEP PERSISTENT
SUSTAINED SPEEDS IN THE 10-15 KT RANGE THROUGH THE REST OF THE DAY.
KMSP...SNOW IS RAPIDLY APPROACHING FROM THE WEST AND SHOULD BE AT
THE FIELD WITHIN THE FIRST HOUR. SOLID IFR OBS HAVE BEEN SEEN WITH
THIS BATCH OF SNOW ALL MORNING AND BASED ON THAT...SENT THE VIS
THAT DIRECTION FOR MSP. HRRR HAS CONTINUED TO HANDEL THIS ACTIVITY
WELL...AND FOLLOWED IT AND THE RAP CLOSELY FOR TIMING SNOW IN/OUT.
LOOKING AT NAM SOUNDINGS...MAY SEE A BRIEF MVFR CIG OR TWO
THURSDAY MORNING...BUT OTHERWISE...VFR CONDITIONS WILL DOMINATE
THIS TAF PERIOD ONCE THE AFTERNOON SNOW MOVES OUT.
/OUTLOOK FOR KMSP/
FRI...VFR. CHC OF -SN AND MVFR VIS/CIG IN MORNING. WIND SW 5-15
KTS.
SAT...MVFR CIGS LIKELY. AFTERNOON -SN POSSIBLE. W WIND 5 KTS BECOMING NW
15-20 KTS WITH GUSTS TO 30 KTS.
SUN...CHANCE OF -SN WITH MVFR OR LOWER CIG/VIS. WINDS W 5-10 KTS
BECOMING NW 15-20 KTS LATE.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
CLF/MPG
AREA FORECAST DISCUSSION
NWS DULUTH MN
1215 PM CST WED JAN 16 2013
.AVIATION.../18Z TAF ISSUANCE/
LOW CLOUDS ASSOC WITH A DEPARTING COLD FRONT WILL CONTINUE TO
DECREASE IN COVERAGE THIS AFTERNOON ACROSS MOST OF THE CWA. BY
THIS EVENING...MOST AREAS SHOULD SEE PARTLY CLOUDY SKIES AS HIGH
PRESSURE FROM CANADA BUILDS ACROSS THE UPPER MIDWEST. AREAS OF
STRATUS MAY REDEVELOP THURSDAY MORNING AS INDICATED BY THE NAM12
TIME/HEIGHT CROSS SECTION.
&&
.PREV DISCUSSION... /ISSUED 1016 AM CST WED JAN 16 2013/
UPDATE...
TOOK OUT MENTION OF FZDZ AND KEPT WITH SCATTERED FLURRIES INTO THE
EARLY AFTERNOON OVER THE NRN COUNTIES WITH LIGHT SNOW/FLURRIES
PERSISTING TO THE SOUTH AS A WEAK SYSTEM SLIDES THROUGH SRN MN.
MINOR CHANGES TO SKY COVER THIS MORNING AND AFTERNOON...HOLDING ON
TO CLOUDS INTO THE EARLY EVENING BEFORE CLEARING THINGS OUT
SOMEWHAT TONIGHT...AND GOING MAINLY PARTLY CLOUDY. STILL EXPECTING
A VERY COLD AIR MASS TO DROP IN ACROSS THE AREA TONIGHT AND BRING
TEMPS DOWN INTO THE TEENS AND 20S BELOW ZERO WITH WIND CHILL
READINGS -25 TO -35. WILL BE ISSUING A WIND CHILL ADVISORY FOR
TONIGHT WITH THE AFTERNOON FORECAST...AND POSSIBLY A WARNING FOR
THE FAR NRN COUNTIES.
PREV DISCUSSION... /ISSUED 551 AM CST WED JAN 16 2013/
AVIATION...12Z TAFS
IFR OR LOW MVFR CEILINGS COVERED MOST OF NORTHEAST
MINNESOTA EARLY THIS MORNING...WITH MVFR CEILINGS AND VSBYS FROM 1 TO 3
MILES IN SNOW OR FREEZING DRIZZLE WERE OCCURRING OVER NORTHWEST
WISCONSIN. MUCH OF THE PRECIPITATION WILL MOVE OUT OF THE
NORTHLAND THIS MORNING...AND CEILINGS WILL INCREASE TO MVFR. WE
FOLLOWED CLOSE TO THE RAP 925MB CONDENSATION PRESSURE DEFICITS TO
TIME CLEARING TODAY. GUSTY WEST TO NORTHWEST WINDS WILL OCCUR THIS
MORNING INTO EARLY AFTERNOON BEFORE DIMINISHING LATE.
PREV DISCUSSION... /ISSUED 408 AM CST WED JAN 16 2013/
SHORT TERM...TODAY THROUGH THURSDAY.
AT 4 AM...LIGHT SNOW CONTINUED TO SPREAD SOUTHEAST ACROSS THE CWA.
THE LOWEST VSBYS WERE NOW IN NW WI. THERE HAS ALSO BEEN SOME
PATCHY FREEZING DRIZZLE ACROSS THE AREA. TEMPERATURES WERE LARGELY
IN THE 20S.
THE MAIN FOCUS FOR THE MORNING WILL CONTINUE TO BE LIGHT SNOW AND
PATCHY FREEZING DRIZZLE. THE COMBINATION OF FREEZING DRIZZLE AND
SNOW WILL MAKE ROADS SLICK THIS MORNING. THE COLD FRONT WILL MOVE
QUICKLY SE ACROSS THE CWA THIS MORNING...FOLLOWED BY FALLING
TEMPERATURES DUE TO STRONG CAA BEHIND THE COLD FRONT. SW WINDS
WILL SWITCH TO THE NW AND BECOME GUSTY DURING THE AFTERNOON.
ARCTIC HIGH PRESSURE WILL BUILD ACROSS THE REGION TONIGHT...WITH
VERY COLD AIR SETTLING INTO THE NORTHLAND. HAVE DROPPED TEMPS EVEN
FURTHER FOR TONIGHT GIVEN THE STRENGTH OF THE ARCTIC AIR. EXPECT
TEMPERATURES TO FALL INTO THE MID 20S BELOW ZERO IN THE NORTH
TONIGHT. WITH WINDS SWITCHING TO THE NW...WE COULD ALSO SEE SOME
LAKE EFFECT SNOW SHOWERS ALONG THE SOUTH SHORE. NOT LOOKING FOR
TOO MUCH IN THE WAY OF SNOW ACCUMULATION AS WINDS WILL BE A BIT
WESTERLY.
ARCTIC HIGH PRESSURE WILL REINFORCE ITSELF ACROSS THE REGION ON
THURSDAY...WITH TEMPERATURES REMAINING BELOW ZERO ACROSS THE
NORTHERN THIRD OF THE CWA. ONCE THE CLOUDS SCOUR OUT THIS
AFTERNOON...WE SHOULD SEE A FAIR AMOUNT OF CLEAR SKIES TONIGHT
INTO THURSDAY.
LONG TERM...THURSDAY NIGHT THROUGH TUESDAY.
MAIN STORY IN THE EXTENDED WILL BE VERY COLD AIR MOVING OVER THE
REGION LATER IN THE WEEKEND...INTO THE MIDDLE OF NEXT WEEK.
UPPER RIDGE OVER THE WEST COAST/EASTERN PACIFIC WILL GRADUALLY SHIFT
OVER THE WESTERN CONUS LATE IN THE PERIOD. AN UPPER LOW OVER HUDSON
BAY WILL SHIFT EAST AND NORTH INTO THE WEEKEND...WITH SHORTWAVES
MOVING THROUGH AND MUCH COLDER AIR MOVING IN OVER THE WEEKEND.
A SHORTWAVE AND WAA WILL AFFECT THE CWA THURSDAY NIGHT LEADING TO A
CHANCE FOR LIGHT SNOW INTO FRIDAY. TEMPS SHOULD DROP QUICKLY
THURSDAY EVENING...THEN RISE OVERNIGHT WITH INCREASING CLOUDS/WAA.
GOOD WAA WILL LEAD TO ACCUMULATIONS FROM A DUSTING TO PERHAPS 2
INCHES. 850MB TEMPS ARE FORECAST TO RISE TO NEAR 0C ACROSS OUR
SOUTHWEST CWA ON FRIDAY...LEADING TO HIGHS IN THE UPPER TWENTIES TO
NEAR 30 IN OUR SOUTHERN ZONES.
ANOTHER WAVE AND SURFACE LOW WILL LEAD TO A CONTINUED CHANCE FOR
LIGHT SNOW FRIDAY NIGHT AND SATURDAY. THE WAVE ON SATURDAY IS
STRONGER...AND THE LATEST ECMWF SUGGESTS A FEW INCHES OF SNOW WILL
BE POSSIBLE...MAINLY OVER NORTHERN MINNESOTA. MUCH COLDER AIR WILL
POUR INTO THE NORTHLAND AS THE LOW PASSES ON SATURDAY. 850MB TEMPS
ARE FORECAST TO DROP TO -20 TO -22C OVER MUCH OF OUR MINNESOTA CWA
SATURDAY AFTERNOON...WITH EVEN COLDER TEMPS MOVING IN SUNDAY NIGHT.
A FAVORABLE PERIOD FOR SIGNIFICANT LES WILL OCCUR ALONG THE SOUTH
SHORE AS THE COLDER AIR MOVES IN SATURDAY AFTERNOON/NIGHT.
COLD WILL BE THE MAIN STORY SUNDAY INTO TUESDAY. LOWS SUNDAY NIGHT
INTO TUESDAY NIGHT WILL BE IN THE TEENS BELOW ZERO TO MID TWENTIES
BELOW. THERE WILL BE ENOUGH WIND SATURDAY NIGHT TO CREATE SOME VERY
LOW WIND CHILLS. HIGHS SUNDAY INTO TUESDAY ARE FORECAST TO REMAIN AT
OR BELOW ZERO OVER NORTHEAST MINNESOTA...AND ONLY BE A FEW DEGREES
WARMER OVER NORTHWEST WISCONSIN.
&&
.POINT TEMPS/POPS...
DLH -13 4 -2 26 / 10 10 40 50
INL -24 -4 -15 18 / 10 10 40 50
BRD -8 9 4 29 / 10 10 40 20
HYR -11 10 -2 30 / 10 10 40 40
ASX -4 10 4 28 / 40 20 40 50
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
AVIATION...BERDES
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1030 AM CST WED JAN 16 2013
.UPDATE...
JUST GOT THROUGH WITH SOME SWEEPING UPDATES TO THE GRIDS...WITH
THE BIG ONE TO DRASTICALLY INCREASE POPS FOR THIS
AFTERNOON...WITH LIKELY POPS NOW INDICATED FROM WEST CENTRAL MN
INTO THE TWIN CITIES. RAP H85/H7 FGEN LOCKING ON TO BAND OF
MODERATE SNOW MOVING OUT OF SE NODAK NOW...WITH THE HRRR
REFLECTIVITY FORECASTS THIS MORNING PICKING UP ON THE AREA AS
WELL. THE RAP TAKES THIS AREA OF FGEN FROM THE AXN AREA DOWN
TOWARD LA CROSSE BY THIS EVENING...WITH HRRR REFLECTIVITY FORECAST
FOLLOWING THIS AREA OF FORCING PRETTY MUCH LOCK AND STEP. AS A
RESULT...BOOSTED THE POPS QUITE A BIT...TAKING THE LEAD OF THE
HRRR/RAP FOR THE REST OF TODAY. NOT EXPECTING MUCH SNOWFALL WITH
THIS...WITH A HALF INCH OF SNOW ACCUMS CURRENTLY INDICATED IN THE
GRIDS. TIMING WISE...THIS LOOKS TO MOVE INTO THE TWIN CITIES JUST
IN TIME FOR THE EVENING COMMUTE...SO WE MAY END UP GOING 2 FOR 2
ON WEATHER SLOWED COMMUTES TODAY.
OTHER THAN POP/WX...INCREASED DEWPS SEVERAL DEGREES OUT AHEAD OF
THE FRONT...WHERE THEY HAVE INCREASED INTO THE 30S THIS
MORNING...AND SPED UP THE TEMP DROP IN THE NW CWA SOME THIS
AFTERNOON...AS WE ARE STARTING TO SEE SOME PRETTY GOOD CAA ACROSS
THE RED RIVER VALLEY...WHERE THE GRAND FORKS AREA IS ALREADY BACK
DOWN INTO THE SINGLE DIGITS.
&&
.PREV DISCUSSION...
/ISSUED 413 AM CST WED JAN 16 2013/
OVERVIEW...NO MAJOR CHANGES TO THE PREVIOUS FORECAST. BACKED OFF
ON THE POPS TODAY IN EASTERN MN AND WESTERN WI...TRAILING WAVE
BEHIND THE COLD FRONT JUST DOESNT LOOK OVERLY IMPRESSIVE.
INCREASED POPS A BIT WITH FRIDAY`S CLIPPER SYSTEM...AS THERE IS
PRETTY GOOD CONTINUITY WITH THAT SYSTEM OVER THE LAST COUPLE MODEL
RUNS. FINALLY...ONLY SLIGHT ADJUSTMENTS TO TEMPERATURES AND WIND
SPEEDS SUNDAY THROUGH MONDAY WITH THE BLAST OF ARCTIC AIR...BUT
ENDED UP WITH MORE LOCATIONS WITH APPARENT TEMPERATURES BETWEEN 30
AND 40 BELOW ZERO...EVEN AS EARLY AS SUNDAY NIGHT WHEN THE WIND
LOOKS TO BE BLUSTERY.
COLD FRONT AND SURFACE TROUGH MAKING STEADY PROGRESS ACROSS
MINNESOTA THIS MORNING. INTERESTING TEMPERATURE TREND THIS MORNING IN
WESTERN MN AND THE DAKOTAS. FOR EXAMPLE...THE TEMPERATURE AT
KGFK HAS GONE FROM 21...23...29...34...37...27...24...19 OVER THE
LAST 8 HOURS ENDING AT 4 AM. FARGO IS ACTUALLY REPORTING LIGHT
RAIN THIS MORNING AS WELL. COLDER AIR IS CERTAINLY ON THE WAY
BEHIND THIS CLIPPER SYSTEM AND IT SHOULD LIMIT TEMPS IN NORTHERN
PORTIONS OF THE FORECAST AREA TODAY. TRIED TO INCLUDE A NON-
DIURNAL TEMPERATURE TREND OVER THE NEXT 24 HOURS. GIVEN THE SPEED
OF THE COLD FRONT AND POSITION OF STRONGEST RADAR RETURNS IN
RELATION TO THIS FRONT...MOST OF MINNESOTA MIGHT ONLY END UP WITH
A FEW FLURRIES OR SPRINKLES TODAY. THE TRAILING WAVE IS SUBTLE AT
THIS POINT AND IT`S DIFFICULT EVEN TO PICK OUT IN WATER VAPOR.
THIS SHOULD VIRTUALLY BE A NON ISSUE IN TERMS OF PRECIP FOR
EASTERN MN AND WESTERN WI THIS AFTERNOON. REDUCED POPS...BUT DID
NOT GO COMPLETELY DRY...AND STILL KEEP 40%-50% GOING IN WESTERN
MN. TEMP FORECAST TODAY IS CHALLENGING...BUT EVEN WITH CLOUD COVER
WE MIGHT BE TOO COOL IN SPOTS WHERE WE HAVE MID 30S GOING GIVEN
THE QUICK WARM FRONTAL PASSAGE TODAY. MIGHT SEE A LOT OF UPPER 30S
AND POSSIBLY EVEN A COUPLE 40S.
THE 16.00Z GFS HAS JOGGED NORTH A BIT WITH FRIDAY`S CLIPPER
SYSTEM...THE ECMWF HAS COME FARTHER SOUTH BUT IS WEAKER AND
BROADER WITH THE SURFACE REFLECTION. STILL WORTH A MENTION OF SNOW
ON FRIDAY GIVEN THIS SIGNAL HAS BEEN SHOWING UP FOR A COUPLE DAYS
NOW. LIGHT SNOW LOOKS MORE PROMISING IN NORTHERN MN AND FAR
NORTHERN WI. THIS SYSTEM ACTUALLY HAS A TRAILING SURFACE LOW THAT
LINGERS INTO SATURDAY. THIS MIGHT MEAN MORE CLOUD COVER/PERHAPS
FLURRIES THAN WHAT IS CURRENTLY IN THE FORECAST.
WE`VE BEEN ADVERTISING THE STRONG ARCTIC AIR MASS FOR SUNDAY NIGHT
THROUGH MONDAY NIGHT...FOR AT LEAST TWO DAYS NOW. NOT MUCH CHANGE
WITH LAST NIGHTS MODEL RUNS...AS THE ARCTIC BOUNDARY COMES IN
QUICK AND THE AIR MASS ALREADY BEGINS TO MODERATE BY TUESDAY.
HOWEVER...THE LATEST FORECAST WIND CHILLS ARE IMPRESSIVELY COLD
EVEN SUNDAY NIGHT WITH HIGH BUILDING IN ACROSS THE DAKOTAS AND
REMNANT SURFACE TROUGH HANGING BACK OVER THE WARMER GREAT LAKES IN
THE WAKE OF THE CLIPPER SYSTEM. THERE SHOULD BE A STRONG PUSH OF
COLD AIR WITH THE ARCTIC BOUNDARY AND THE PRESSURE GRADIENT
SUGGESTS BLUSTERY WINDS AS COLD AIR ADVECTION KICKS IN GEAR.
MONDAY HAS A LOOK OF ONE THOSE CLASSICALLY COLD MN/WI DAYS YOU MAY
REMEMBER FROM YOUR CHILDHOOD...AND AT THE VERY LEAST SINCE 2009.
BREEZY NORTHERLY WINDS AND HIGH TEMPERATURES BETWEEN -2 AND -12
WITH SUNNY SKIES. THE LACK OF SNOW COVER IN PORTIONS OF WEST
CENTRAL WI AND SOUTHERN MN WILL KEEP TEMPS WARMER BY A FEW
DEGREES...BUT NONETHELESS...THIS WILL BE SOME OF THE COLDEST AIR
WE`VE SEEN IN THE LAST 3-4 YEARS. WE SHOULD SEE WIND CHILLS
BETWEEN 25 AND 40 BELOW ACROSS MUCH OF THE AREA. WIND CHILL
ADVISORY/WARNINGS WILL BE NEEDED SUNDAY/TUESDAY.
&&
.AVIATION.../12Z TAF ISSUANCE/
FIRST AREA OF LIGHT SNOW FOR TODAY ASSOCIATED WITH WARM AIR
ADVECTION AND THIS IS MOVING QUICKLY SOUTHEAST WITH SOME
REDEVELOPMENT. SYSTEM IS STRENGTHENING A BIT AND VSBYS HAVE
DROPPED IN ERN MN AND WESTERN WISC. WILL HAVE SOME IFR VSBY THIS
MORNING WHILE CEILINGS STAY GENERALLY IN THE 1000-1500 FOOT AGL
LAYER. HOWEVER...A FEW AREAS WILL HAVE IFR CIGS.
SOME LOWER CEILINGS BEHIND PRECIP...AND ALSO COLD ADVECTION BEHIND
COLD FRONT ENTERING CENTRAL MN HAS LED TO SOME IFR CEILINGS WHICH
WILL AFFECT AXN/STC FOR A FEW HOURS THIS MORNING.
SECOND BATCH OF LIGHT SNOW LOOKS TO MOVE INTO WEST CENTRAL INTO
SOUTH CENTRAL MN LATE MORNING AND AFTERNOON. KRWF WILL SEE MVFR
CIGS/VSBY THIS AFTERNOON. THERE IS A SMALL CHANCE IT COULD LOWER
TO IFR BUT HAVE NOT ADDED THIS TO TAF. AFTER THAT...VFR CONDITIONS
WITH NW WIND GRADUALLY DIMINISHING TO 5-7 KTS TONIGHT.
KMSP...IFR VSBY IN LIGHT SNOW WILL PERSIST TIL 14Z. AFTER THAT...
EXPECT MVFR CIGS/VSBYS THE REST OF THE MORNING. LIGHT SNOW THIS AFTERNOON
SHOULD AFFECT WEST CENTRAL INTO SOUTH CENTRAL MN AND THEREFORE BYPASS
KMSP TO THE SOUTHWEST. THERE IS A SMALL CHANCE OF FLURRIES THIS
AFTERNOON BUT NOT ENOUGH CONFIDENCE TO ADD THAT. NW WIND WILL
DECREASE THIS EVENING.
/OUTLOOK FOR KMSP/
THU...VFR. W WIND 5-10 KTS.
FRI...VFR. CHC FLURRIES. SW WIND 5-15 KTS.
SAT...MVFR CIGS LIKELY. CHC MVFR VSBY. W WIND 5 KTS BECOMING NW
15-20 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
MPG/CLF/TDK
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1016 AM CST WED JAN 16 2013
.UPDATE...
TOOK OUT MENTION OF FZDZ AND KEPT WITH SCATTERED FLURRIES INTO THE
EARLY AFTERNOON OVER THE NRN COUNTIES WITH LIGHT SNOW/FLURRIES
PERSISTING TO THE SOUTH AS A WEAK SYSTEM SLIDES THROUGH SRN MN.
MINOR CHANGES TO SKY COVER THIS MORNING AND AFTERNOON...HOLDING ON
TO CLOUDS INTO THE EARLY EVENING BEFORE CLEARING THINGS OUT
SOMEWHAT TONIGHT...AND GOING MAINLY PARTLY CLOUDY. STILL EXPECTING
A VERY COLD AIR MASS TO DROP IN ACROSS THE AREA TONIGHT AND BRING
TEMPS DOWN INTO THE TEENS AND 20S BELOW ZERO WITH WIND CHILL
READINGS -25 TO -35. WILL BE ISSUING A WIND CHILL ADVISORY FOR
TONIGHT WITH THE AFTERNOON FORECAST...AND POSSIBLY A WARNING FOR
THE FAR NRN COUNTIES.
&&
.PREV DISCUSSION... /ISSUED 551 AM CST WED JAN 16 2013/
AVIATION...12Z TAFS
IFR OR LOW MVFR CEILINGS COVERED MOST OF NORTHEAST
MINNESOTA EARLY THIS MORNING...WITH MVFR CEILINGS AND VSBYS FROM 1 TO 3
MILES IN SNOW OR FREEZING DRIZZLE WERE OCCURRING OVER NORTHWEST
WISCONSIN. MUCH OF THE PRECIPITATION WILL MOVE OUT OF THE
NORTHLAND THIS MORNING...AND CEILINGS WILL INCREASE TO MVFR. WE
FOLLOWED CLOSE TO THE RAP 925MB CONDENSATION PRESSURE DEFICITS TO
TIME CLEARING TODAY. GUSTY WEST TO NORTHWEST WINDS WILL OCCUR THIS
MORNING INTO EARLY AFTERNOON BEFORE DIMINISHING LATE.
PREV DISCUSSION... /ISSUED 408 AM CST WED JAN 16 2013/
SHORT TERM...TODAY THROUGH THURSDAY.
AT 4 AM...LIGHT SNOW CONTINUED TO SPREAD SOUTHEAST ACROSS THE CWA.
THE LOWEST VSBYS WERE NOW IN NW WI. THERE HAS ALSO BEEN SOME
PATCHY FREEZING DRIZZLE ACROSS THE AREA. TEMPERATURES WERE LARGELY
IN THE 20S.
THE MAIN FOCUS FOR THE MORNING WILL CONTINUE TO BE LIGHT SNOW AND
PATCHY FREEZING DRIZZLE. THE COMBINATION OF FREEZING DRIZZLE AND
SNOW WILL MAKE ROADS SLICK THIS MORNING. THE COLD FRONT WILL MOVE
QUICKLY SE ACROSS THE CWA THIS MORNING...FOLLOWED BY FALLING
TEMPERATURES DUE TO STRONG CAA BEHIND THE COLD FRONT. SW WINDS
WILL SWITCH TO THE NW AND BECOME GUSTY DURING THE AFTERNOON.
ARCTIC HIGH PRESSURE WILL BUILD ACROSS THE REGION TONIGHT...WITH
VERY COLD AIR SETTLING INTO THE NORTHLAND. HAVE DROPPED TEMPS EVEN
FURTHER FOR TONIGHT GIVEN THE STRENGTH OF THE ARCTIC AIR. EXPECT
TEMPERATURES TO FALL INTO THE MID 20S BELOW ZERO IN THE NORTH
TONIGHT. WITH WINDS SWITCHING TO THE NW...WE COULD ALSO SEE SOME
LAKE EFFECT SNOW SHOWERS ALONG THE SOUTH SHORE. NOT LOOKING FOR
TOO MUCH IN THE WAY OF SNOW ACCUMULATION AS WINDS WILL BE A BIT
WESTERLY.
ARCTIC HIGH PRESSURE WILL REINFORCE ITSELF ACROSS THE REGION ON
THURSDAY...WITH TEMPERATURES REMAINING BELOW ZERO ACROSS THE
NORTHERN THIRD OF THE CWA. ONCE THE CLOUDS SCOUR OUT THIS
AFTERNOON...WE SHOULD SEE A FAIR AMOUNT OF CLEAR SKIES TONIGHT
INTO THURSDAY.
LONG TERM...THURSDAY NIGHT THROUGH TUESDAY.
MAIN STORY IN THE EXTENDED WILL BE VERY COLD AIR MOVING OVER THE
REGION LATER IN THE WEEKEND...INTO THE MIDDLE OF NEXT WEEK.
UPPER RIDGE OVER THE WEST COAST/EASTERN PACIFIC WILL GRADUALLY SHIFT
OVER THE WESTERN CONUS LATE IN THE PERIOD. AN UPPER LOW OVER HUDSON
BAY WILL SHIFT EAST AND NORTH INTO THE WEEKEND...WITH SHORTWAVES
MOVING THROUGH AND MUCH COLDER AIR MOVING IN OVER THE WEEKEND.
A SHORTWAVE AND WAA WILL AFFECT THE CWA THURSDAY NIGHT LEADING TO A
CHANCE FOR LIGHT SNOW INTO FRIDAY. TEMPS SHOULD DROP QUICKLY
THURSDAY EVENING...THEN RISE OVERNIGHT WITH INCREASING CLOUDS/WAA.
GOOD WAA WILL LEAD TO ACCUMULATIONS FROM A DUSTING TO PERHAPS 2
INCHES. 850MB TEMPS ARE FORECAST TO RISE TO NEAR 0C ACROSS OUR
SOUTHWEST CWA ON FRIDAY...LEADING TO HIGHS IN THE UPPER TWENTIES TO
NEAR 30 IN OUR SOUTHERN ZONES.
ANOTHER WAVE AND SURFACE LOW WILL LEAD TO A CONTINUED CHANCE FOR
LIGHT SNOW FRIDAY NIGHT AND SATURDAY. THE WAVE ON SATURDAY IS
STRONGER...AND THE LATEST ECMWF SUGGESTS A FEW INCHES OF SNOW WILL
BE POSSIBLE...MAINLY OVER NORTHERN MINNESOTA. MUCH COLDER AIR WILL
POUR INTO THE NORTHLAND AS THE LOW PASSES ON SATURDAY. 850MB TEMPS
ARE FORECAST TO DROP TO -20 TO -22C OVER MUCH OF OUR MINNESOTA CWA
SATURDAY AFTERNOON...WITH EVEN COLDER TEMPS MOVING IN SUNDAY NIGHT.
A FAVORABLE PERIOD FOR SIGNIFICANT LES WILL OCCUR ALONG THE SOUTH
SHORE AS THE COLDER AIR MOVES IN SATURDAY AFTERNOON/NIGHT.
COLD WILL BE THE MAIN STORY SUNDAY INTO TUESDAY. LOWS SUNDAY NIGHT
INTO TUESDAY NIGHT WILL BE IN THE TEENS BELOW ZERO TO MID TWENTIES
BELOW. THERE WILL BE ENOUGH WIND SATURDAY NIGHT TO CREATE SOME VERY
LOW WIND CHILLS. HIGHS SUNDAY INTO TUESDAY ARE FORECAST TO REMAIN AT
OR BELOW ZERO OVER NORTHEAST MINNESOTA...AND ONLY BE A FEW DEGREES
WARMER OVER NORTHWEST WISCONSIN.
&&
.POINT TEMPS/POPS...
DLH 27 -13 4 -2 / 10 10 10 40
INL 17 -24 -4 -15 / 10 10 10 40
BRD 30 -8 9 4 / 20 10 10 40
HYR 28 -11 10 -2 / 20 10 10 40
ASX 27 -4 10 4 / 20 40 20 40
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...TENTINGER
AREA FORECAST DISCUSSION
NWS DULUTH MN
551 AM CST WED JAN 16 2013
.AVIATION...12Z TAFS
IFR OR LOW MVFR CEILINGS COVERED MOST OF NORTHEAST
MINNESOTA EARLY THIS MORNING...WITH MVFR CEILINGS AND VSBYS FROM 1 TO 3
MILES IN SNOW OR FREEZING DRIZZLE WERE OCCURRING OVER NORTHWEST
WISCONSIN. MUCH OF THE PRECIPITATION WILL MOVE OUT OF THE
NORTHLAND THIS MORNING...AND CEILINGS WILL INCREASE TO MVFR. WE
FOLLOWED CLOSE TO THE RAP 925MB CONDENSATION PRESSURE DEFICITS TO
TIME CLEARING TODAY. GUSTY WEST TO NORTHWEST WINDS WILL OCCUR THIS
MORNING INTO EARLY AFTERNOON BEFORE DIMINISHING LATE.
&&
.PREV DISCUSSION... /ISSUED 408 AM CST WED JAN 16 2013/
SHORT TERM...TODAY THROUGH THURSDAY.
AT 4 AM...LIGHT SNOW CONTINUED TO SPREAD SOUTHEAST ACROSS THE CWA.
THE LOWEST VSBYS WERE NOW IN NW WI. THERE HAS ALSO BEEN SOME
PATCHY FREEZING DRIZZLE ACROSS THE AREA. TEMPERATURES WERE LARGELY
IN THE 20S.
THE MAIN FOCUS FOR THE MORNING WILL CONTINUE TO BE LIGHT SNOW AND
PATCHY FREEZING DRIZZLE. THE COMBINATION OF FREEZING DRIZZLE AND
SNOW WILL MAKE ROADS SLICK THIS MORNING. THE COLD FRONT WILL MOVE
QUICKLY SE ACROSS THE CWA THIS MORNING...FOLLOWED BY FALLING
TEMPERATURES DUE TO STRONG CAA BEHIND THE COLD FRONT. SW WINDS
WILL SWITCH TO THE NW AND BECOME GUSTY DURING THE AFTERNOON.
ARCTIC HIGH PRESSURE WILL BUILD ACROSS THE REGION TONIGHT...WITH
VERY COLD AIR SETTLING INTO THE NORTHLAND. HAVE DROPPED TEMPS EVEN
FURTHER FOR TONIGHT GIVEN THE STRENGTH OF THE ARCTIC AIR. EXPECT
TEMPERATURES TO FALL INTO THE MID 20S BELOW ZERO IN THE NORTH
TONIGHT. WITH WINDS SWITCHING TO THE NW...WE COULD ALSO SEE SOME
LAKE EFFECT SNOW SHOWERS ALONG THE SOUTH SHORE. NOT LOOKING FOR
TOO MUCH IN THE WAY OF SNOW ACCUMULATION AS WINDS WILL BE A BIT
WESTERLY.
ARCTIC HIGH PRESSURE WILL REINFORCE ITSELF ACROSS THE REGION ON
THURSDAY...WITH TEMPERATURES REMAINING BELOW ZERO ACROSS THE
NORTHERN THIRD OF THE CWA. ONCE THE CLOUDS SCOUR OUT THIS
AFTERNOON...WE SHOULD SEE A FAIR AMOUNT OF CLEAR SKIES TONIGHT
INTO THURSDAY.
LONG TERM...THURSDAY NIGHT THROUGH TUESDAY.
MAIN STORY IN THE EXTENDED WILL BE VERY COLD AIR MOVING OVER THE
REGION LATER IN THE WEEKEND...INTO THE MIDDLE OF NEXT WEEK.
UPPER RIDGE OVER THE WEST COAST/EASTERN PACIFIC WILL GRADUALLY SHIFT
OVER THE WESTERN CONUS LATE IN THE PERIOD. AN UPPER LOW OVER HUDSON
BAY WILL SHIFT EAST AND NORTH INTO THE WEEKEND...WITH SHORTWAVES
MOVING THROUGH AND MUCH COLDER AIR MOVING IN OVER THE WEEKEND.
A SHORTWAVE AND WAA WILL AFFECT THE CWA THURSDAY NIGHT LEADING TO A
CHANCE FOR LIGHT SNOW INTO FRIDAY. TEMPS SHOULD DROP QUICKLY
THURSDAY EVENING...THEN RISE OVERNIGHT WITH INCREASING CLOUDS/WAA.
GOOD WAA WILL LEAD TO ACCUMULATIONS FROM A DUSTING TO PERHAPS 2
INCHES. 850MB TEMPS ARE FORECAST TO RISE TO NEAR 0C ACROSS OUR
SOUTHWEST CWA ON FRIDAY...LEADING TO HIGHS IN THE UPPER TWENTIES TO
NEAR 30 IN OUR SOUTHERN ZONES.
ANOTHER WAVE AND SURFACE LOW WILL LEAD TO A CONTINUED CHANCE FOR
LIGHT SNOW FRIDAY NIGHT AND SATURDAY. THE WAVE ON SATURDAY IS
STRONGER...AND THE LATEST ECMWF SUGGESTS A FEW INCHES OF SNOW WILL
BE POSSIBLE...MAINLY OVER NORTHERN MINNESOTA. MUCH COLDER AIR WILL
POUR INTO THE NORTHLAND AS THE LOW PASSES ON SATURDAY. 850MB TEMPS
ARE FORECAST TO DROP TO -20 TO -22C OVER MUCH OF OUR MINNESOTA CWA
SATURDAY AFTERNOON...WITH EVEN COLDER TEMPS MOVING IN SUNDAY NIGHT.
A FAVORABLE PERIOD FOR SIGNIFICANT LES WILL OCCUR ALONG THE SOUTH
SHORE AS THE COLDER AIR MOVES IN SATURDAY AFTERNOON/NIGHT.
COLD WILL BE THE MAIN STORY SUNDAY INTO TUESDAY. LOWS SUNDAY NIGHT
INTO TUESDAY NIGHT WILL BE IN THE TEENS BELOW ZERO TO MID TWENTIES
BELOW. THERE WILL BE ENOUGH WIND SATURDAY NIGHT TO CREATE SOME VERY
LOW WIND CHILLS. HIGHS SUNDAY INTO TUESDAY ARE FORECAST TO REMAIN AT
OR BELOW ZERO OVER NORTHEAST MINNESOTA...AND ONLY BE A FEW DEGREES
WARMER OVER NORTHWEST WISCONSIN.
&&
.POINT TEMPS/POPS...
DLH 26 -14 4 -2 / 30 10 10 40
INL 19 -26 -4 -15 / 10 10 10 40
BRD 28 -12 9 4 / 20 10 10 40
HYR 30 -11 10 -2 / 60 10 10 40
ASX 30 -6 10 4 / 60 40 20 40
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...DAP
LONG TERM....MELDE
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
539 PM CST THU JAN 17 2013
.AVIATION...00Z TAFS FOR KOFK...KLNK AND KOMA.
GENERALLY VFR CONDITIONS ARE EXPECTED THROUGH FRIDAY AFTERNOON. AN
AREA OF DENSE FOG FROM JUST WEST OF KOMA TO THE NORTH SHOULD
REMAIN WEST OF KOMA...BUT COULD EXPAND EAST FOR A TIME IN THE
EVENING. THEN SOUTHWEST LOW LEVEL JET WILL KICK IN BY 06Z KEEPING
MOST FOG AND LOW CLOUDS FROM FORMING. LOW LEVEL WIND SHEAR WILL
RESULT FROM THE STRONG LOW LEVEL JET...WITH SPEEDS CLOSE TO 50KT
AT FL020.
DERGAN
&&
.PREV DISCUSSION... /ISSUED 333 PM CST THU JAN 17 2013/
SHORT TERM...TONIGHT THROUGH SUNDAY
MAIN FORECAST PROBLEM IS TEMPS AND WINDS WITH THE STRONG COLD
FRONT ON SATURDAY AND ANOTHER FRONT SUNDAY/SUNDAY NIGHT.
HOWEVER THE INITIAL ISSUE IS THE PERSISTENT AREA OF FOG AND
STRATUS THAT REMAINED JUST EAST OF OMAHA THROUGHOUT THE DAY...BUT
AFTERNOON VISIBLE LOOP SHOWS THAT AREA IS FINALLY ERODING WITH THE
HELP OF AFTERNOON WARMING AND A WEST COMPONENT TO THE CLOUD TOP
WINDS. AS TO WHETHER OR NOT THIS FOG/STRATUS WILL FORM AGAIN
TONIGHT...WE BELIEVE THE STRENGTHENING WESTERLY 850MB WINDS SHOULD
KEEP THE LAYER MIXED ENOUGH TO PREVENT REFORMING AND SOME WARMING
IN THE LAYER SHOULD HELP AS WELL.
ASSUMING FRIDAY STARTS WITHOUT THE STRATUS DECK...THE WESTERLY
850 WINDS WILL INFLUENCE A FAIRLY QUICK WARM UP THROUGHOUT THE
MORNING AND HIGHS SHOULD REACH THE 50S MOST AREAS. THOSE LOCATIONS
WHERE AN INCH OR MORE OF SNOW REMAINS WILL BE A FEW DEGREES
COOLER...WHICH IS MAINLY WEST AND NORTH OF LINCOLN INTO THE
FREMONT AREA.
ON FRIDAY THE MAIN UPPER JET REMAINS WELL NORTH OF THE FORECAST
AREA... HOWEVER A STRENGTHENING NORTHWEST FLOW JET MAX IS
FORECAST TO BE MOVING THROUGH SOUTHERN ALBERTA/SASKATCHEWAN WHICH
QUICKLY PUSHES ARCTIC AIR SOUTH THROUGH THE PLAINS. MODELS ARE IN
GOOD AGREEMENT WITH THE TIMING AND STRENGTH OF THE COLD FRONTAL
PASSAGE ACROSS OUR AREA SATURDAY. BEFORE THE FRONT MOVES
THROUGH ON SATURDAY...THE AIRMASS WILL AGAIN SUPPORT WARM
TEMPERATURES IN THE 40S BUT SOME CLOUD COVER WILL LIMIT WARMING.
BEHIND THE FRONT NORTHWEST WINDS WILL INCREASE CONSIDERABLY WITH
GUSTS OF 30 MPH AND SHARPLY FALLING TEMPERATURES. THE AIRMASS WILL
REMAIN TOO DRY FOR ANY PRECIPITATION WITH THIS SYSTEM.
BY SUNDAY A 1032+ SURFACE HIGH BUILDS IN WITH HIGHS MOSTLY IN THE
20S. ALSO ON SUNDAY THE UPPER RIDGE ALONG THE WEST COAST IS
PROGGED TO AMPLIFY AND THUS PUSH ANOTHER COLD FRONT THROUGH THE
PLAINS...THIS TIME FOLLOWED BY A STRONGER SURFACE HIGH OF AROUND
1040MB. NAM AND GFS ARE IN FAIR AGREEMENT ON THE TIMING OF THE
SUNDAY FRONT BUT THE 12Z ECMWF IS A BIT SLOWER. EITHER WAY WE WILL
SEE ANOTHER SURGE OF ARCTIC AIR AND COLDER TEMPERATURES. WIND
CHILLS COULD DROP INTO THE MINUS 15 TO MINUS 20 DEGREE RANGE LATE
SUNDAY NIGHT AND MONDAY MORNING ESPECIALLY IN NORTHEAST NEBRASKA.
ONE FACTOR THAT WILL HELP KEEP TEMPERATURES FROM PLUMMETING WELL BELOW
ZERO WITH THESE ARCTIC BLASTS WILL BE THE LACK OF SNOW COVER.
HOWEVER COMPARED TO THE WARM DAYS LEADING UP TO SUNDAY...THE
CHANGE IN TEMPERATURES AND WIND CHILLS WILL SURELY HAVE AN IMPACT
ON THE REGION.
NIETFELD
LONG TERM...SUNDAY NIGHT THROUGH THURSDAY
MAIN CONCERN CONTINUES TO BE TEMPERATURES THROUGH THE PERIOD.
ARCTIC AIRMASS IS STILL PROGGED TO PUSH INTO THE AREA THIS
WEEKEND...WITH REINFORCING COLD AIR ON SUNDAY NIGHT/MONDAY. CWA
WILL BE ON THE WESTERN FRINGE OF THE COLDEST AIR...AND LACKING IN
SNOWPACK...BUT STILL COULD SEE TEMPS FALL INTO THE SINGLE DIGITS
BELOW TO SINGLE DIGITS ABOVE ZERO...WITH RECOVERY INTO THE LOWER
TEENS TO LOWER 20S ON MONDAY. MODERATING TEMPERATURES WILL THEN
CONTINUE THROUGH AT LEAST WEDNESDAY NIGHT AS UPPER-LEVEL RIDGE MOVES
OVERHEAD AND LOW-LEVEL SOUTHWEST FLOW CONTINUES. BY WEDNESDAY
NIGHT/THURSDAY...ECMWF AND GFS BOTH INDICATE A STORM SYSTEM MOVING
OUT OF THE ROCKIES AND ACROSS THE PLAINS. GFS AND 00Z ECMWF KEPT
PRECIP EAST OF THE CWA...WHILE 12Z ECMWF IS A LITTLE SLOWER AND
DEEPER AND DOES PLACE CWA IN A MORE FAVORABLE LOCATION FOR PRECIP.
FOR NOW...BLENDS WERE DRY AND BELIEVE THAT IS THE WAY TO LEAN UNTIL
MODELS DEVELOP SOME CONSISTENCY WITH THE THURSDAY SYSTEM. COLD AIR
WILL SPILL IN AGAIN BEHIND THE SYSTEM...BEGINNING SOMETIME AROUND
THURSDAY.
MAYES
AVIATION...
18Z TAFS FOR KOMA...KOFK...KLNK
INITIAL CONCERN WILL BE HOW THE STRATUS WILL AFFECT KOMA NOW THAT
IT IS MOVING OUT OF KLNK AND IS TO THE EAST OF KOFK. THE RAP SEEMS
TO BE HANDLING THE STRATUS THE BEST...ALTHOUGH MAY NOT BE
EXTENSIVE ENOUGH WITH THE WEAK FLOW. IFR CONDITIONS HAVE SPREAD
INTO MLE AND WITH THE LIGHT NORTHEAST DRIFT OF THE DECK...DID
BRING THE DECK IN KOMA THROUGH 00Z. WILL NEED TO MONITOR THIS
AFTERNOON UNTIL EARLY EVENING TO SEE HOW MUCH THE AREA IS ABLE TO
SHRINK DURING THE AFTERNOON.
AFTER 03Z...THE LOW LEVEL JET STRENGTHENS AND HAVE ADDED TO ALL
THREE TAF FORECASTS. THIS SHOULD HINDER ANY LOW CLOUDS
DEVELOPMENT.
ZAPOTOCNY
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
99/99
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1000 PM EST THU JAN 17 2013
.SYNOPSIS...
AN INTENSE AND QUICK MOVING AREA OF LOW PRESSURE WILL BRING
WIND...RAIN AND A RETURN TO CHILLY TEMPERATURES TONIGHT. THE
WINTER CHILL WILL PERSIST INTO THE WEEKEND AND THEN PERIODICALLY
BE REINFORCED BY SUCCESSIVE...DRY COLD FRONTS THROUGH MUCH OF
NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1000 PM THURSDAY...THE COLD FRONT IS NOW WELL OFFSHORE. THE
BAND OF HEAVY RAINFALL AND EMBEDDED CONVECTION WITHIN THE ENHANCED
ZONE OF ASCENT IS OFFSHORE TOO. ATTENTION NOW TURNS TO THE UPPER
LEVEL LOW CURRENTLY OVER UPSTATE SOUTH CAROLINA. THIS SWIRLING
BALL OF COLD AIR ALOFT IS FORECAST BY ALL MODEL GUIDANCE TO MOVE
NORTHEASTWARD TO THE SOUTHERN CHESAPEAKE BAY BY 3-5 AM. STEEP LAPSE
RATES ALOFT AND DEEP MOISTURE ASSOCIATED WITH THIS LOW ARE PRODUCING
WIDESPREAD LIGHT PRECIPITATION EXTENDING FROM UPSTATE SOUTH CAROLINA
ACROSS THE WESTERN TWO-THIRDS OF NORTH CAROLINA. UNDERNEATH THIS
UPPER SYSTEM...COLD AIR BEING PULLED SOUTH BEHIND THE DEPARTING
SURFACE LOW HAS CHANGED RAIN OVER TO SNOW ALONG AND NORTH OF A LINE
FROM JUST NORTH OF CHARLOTTE TO ASHEBORO TO RALEIGH. WHILE THE
CHANCES FOR MEASURABLE SNOW HAVE NEVER BEEN GOOD IN OUR FORECAST
AREA...THERE REMAINS A SMALL POTENTIAL THAT THE RAIN COULD END MIXED
WITH SNOW ACROSS BENNETTSVILLE...LUMBERTON AND ELIZABETHTOWN AFTER
MIDNIGHT. NO ACCUMULATIONS ARE EXPECTED DUE TO ABOVE-FREEZING AIR
TEMPERATURES AND WELL-ABOVE FREEZING GROUND TEMPERATURES.
ALSO...I SPOKE TO A REPRESENTATIVE WITH THE EMERGENCY MANAGEMENT
AGENCY IN COLUMBUS COUNTY WHO REPORTED FAIRLY WIDESPREAD AND
SUBSTANTIAL DAMAGE FROM THE LINE OF SHOWERS THAT MOVED THROUGH THERE
AROUND 645 PM. WE WILL BE SENDING A STORM SURVEY TEAM OUT TO THE
CHADBOURN COMMUNITY IN WESTERN COLUMBUS COUNTY TOMORROW MORNING TO
SURVEY AND CLASSIFY THE DAMAGE THERE.
PREVIOUS DISCUSSION FROM 630 PM FOLLOWS...
A POWERFUL UPPER LEVEL LOW IN NORTHWEST GEORGIA WILL MOVE
EAST-NORTHEASTWARD TONIGHT...SPREADING A VARIETY OF WEATHER ACROSS
THE CAROLINAS. SURFACE LOW PRESSURE OUT AHEAD OF THE UPPER SYSTEM
EXISTS UNDER THE STRONGEST UPPER LEVEL DIVERGENCE AND COUPLED
DEEP-LAYER ASCENT. A 100-MILE WIDE BAND OF MODERATE TO HEAVY RAIN IS
SWEEPING EAST RAPIDLY ACROSS THE AREA AND SHOULD BE OFFSHORE EAST OF
MYRTLE BEACH BY 8 PM...AND OFFSHORE EAST OF WILMINGTON BY 10 PM.
RAINFALL AMOUNTS WITHIN THIS BAND ARE AVERAGING 0.25 TO 0.50 INCHES
PER HOUR. SCATTERED CONVECTIVE CELLS OUT AHEAD OF THE MAIN RAIN BAND
BRIEFLY DISPLAYED ROTATIONAL SIGNATURES THAT REALLY CAUGHT OUR
ATTENTION EARLIER...BUT THIS DEVELOPED AS THE CELLS CROSSED NORTH OF
A VERY PRONOUNCED FRONT THAT LIES FROM JUST SOUTH OF WILMINGTON
THROUGH JUST NORTH OF WHITEVILLE. A VERY STABLE LOW-LEVEL
ENVIRONMENT NORTH OF THE BOUNDARY KEPT POSSIBLE FUNNEL CLOUDS FROM
REACHING THE SURFACE. ADDITIONAL SHOWERS WITHIN THE FRONTAL BAND
ITSELF ARE TRANSPORTING DOWN 50-70 KNOT WINDS OBSERVED ON THIS
EVENING`S CHARLESTON SC WEATHER BALLOON FLIGHT JUST 3000-4000 FT OFF
THE GROUND. DOWNED TREES HAVE BEEN REPORTED FROM A NORTHERN HORRY
COUNTY ALREADY.
ONCE THIS BAND OF MODERATE TO HEAVY RAIN SWEEPS OFFSHORE...PRECIP
CHANCES WILL FALL TREMENDOUSLY FOR THE REMAINDER OF TONIGHT FOR
ABOUT THE SOUTHERN TWO-THIRDS OF OUR FORECAST AREA WHICH INCLUDES
THE AREAS SOUTH OF FLORENCE...MARION...MYRTLE BEACH AND SOUTHPORT
WHERE A DRY...STABLE MID LEVEL ENVIRONMENT SHOULD PREVAIL. CLOSER TO
THE PATH THE STRONG UPPER LEVEL LOW IS EXPECTED TO TAKE...THE MID
LEVEL ENVIRONMENT WILL BE MUCH MORE MOIST AND LAPSE RATES WILL BE
MUCH STEEPER. THIS WILL KEEP PERIODS OF LIGHT RAIN GOING THROUGH
MIDNIGHT AND PERHAPS 2-3 AM FOR DARLINGTON...BENNETTSVILLE...
LUMBERTON...AND ELIZABETHTOWN.
THE BIG QUESTION IS HOW MUCH COLD AIR ARRIVES IN THE LOWER LEVELS
FOR A POSSIBLE CHANGEOVER TO SNOW IN OUR NORTHERN AREAS. EXAMINING
MODEL RH ON THE -8C TO -12C SURFACES THERE SHOULD BE DENDRITIC
CRYSTAL GROWTH UP IN THE CLOUDS UP BEGINNING AROUND 10 PM AND
LASTING THROUGH 2-3 AM FROM NORTH OF FLORENCE THROUGH ELIZABETHTOWN.
IN THE LOW LEVELS COLD AIR WILL BE THE LIMITED FACTOR. BASED ON THE
LATEST RUC AND 18Z NAM IT APPEARS SURFACE TEMPS OF 37/38 DEGREES
(IMPLYING AN ABOVE-FREEZING SURFACE-BASED LAYER NO DEEPER THAN 1500
FT) WILL ARRIVE AFTER 12 MIDNIGHT-1 AM...ALLOWING FOR A COUPLE HOURS
OF MIXED RAIN-SNOW BEFORE PRECIPITATION ENDS. QPF BY THIS TIME
SHOULD BE RATHER LIGHT AND WITH ABOVE FREEZING AIR TEMPS AND
WELL-ABOVE FREEZING SOIL TEMPS NO SNOW ACCUMULATIONS ARE EXPECTED. I
HAVE REMOVED SLEET FROM THE FORECAST AS THIS SHOULD ONLY BE A
RAIN-SNOW SCENARIO WITHOUT ANY POTENTIAL FOR MELTING ALOFT AND
REFREEZING.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 2 PM THURSDAY...WINTER IS BACK. IT WILL BE A CHILLY AND
BRISK START TO THE DAY FRI AS THE PRESSURE GRADIENT WILL REMAIN
RATHER TIGHT BETWEEN STRONG HIGH PRESSURE ACROSS THE OHIO AND
TENNESSEE VALLEYS AND LOW PRESSURE INTENSIFYING SE OF NEW ENGLAND.
THE GRADIENT WILL SLACKEN THROUGH THE AFTERNOON AND WIND
GUSTS...UP TO 25 TO 30 MPH...WILL DIMINISH. CHILLY TEMPS FRI
MORNING...ESPECIALLY IN COMPARISON TO RECENT DAYS...COUPLED WITH
THE WIND...WILL MAKE IT FEEL AS IF IT WERE IN THE MID 20S TO LOWER
30S. EVEN WITH BRIGHT SUNSHINE...TEMPS ARE NOT EXPECTED TO RISE
QUICKLY AS 850 MB TEMPS WILL START THE DAY JUST BELOW ZERO DEG.
PREVIOUS THINKING HAS NOT CHANGED AND WILL FORECAST HIGHS BELOW 50
DEGREES IN MOST PLACES...WITH MID 40S MOST COMMON. GOOD
RADIATIONAL COOLING IS EXPECTED FRI NIGHT AS HIGH PRESSURE REACHES
THE AREA. CLEAR SKIES AND VIRTUALLY CALM WIND WILL ALLOW EVE TEMPS
TO QUICKLY DROP AS DEWPOINTS DURING THIS TIME WILL BE WELL DOWN IN
THE 20S. OVERNIGHT LOWS ARE EXPECTED TO REACH THE MID AND UPPER
20S WITH SOME LOWER 20S WHERE RADIATIONAL COOLING MAXIMIZES
LONGEST.
CHILLY SURFACE HIGH PRESSURE WILL STILL BE IN PLACE ON SAT...BUT THE
WESTWARD EXTENT OF THE RIDGE WILL BEGIN TO BREAK DOWN DURING THE
AFTERNOON. SOME WEAK RETURN OF MILDER AIR AHEAD OF THE LEADING EDGE
OF THE NEXT COLD SURGE IS EXPECTED BY SAT AFTERNOON. THEREFORE...
THE SECOND HALF OF THE PERIOD SHOULD NOT BE AS CHILLY AND CLOSER TO
VALUES MORE TYPICAL OF MID JAN. WILL FORECAST HIGHS IN THE LOWER TO
MID 50S SAT. DEWPOINTS WILL BE CLIMBING THROUGH THE DAY SAT AND WITH
NIGHTFALL...TEMPS WILL NOT BE ABLE TO FALL AS RAPIDLY OR AS FAR AS
FRI NIGHT. DO NOT SEE A REASON TO STRAY TOO FAR FROM MODEL CONSENSUS
WHICH BRINGS LOWS TO THE MID AND UPPER 30S OVERNIGHT SAT.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 2 PM THURSDAY...THE LONG TERM APPEARS TO BE ENTIRELY RAIN-FREE
AND INCREASINGLY COLD. SUNDAY WILL BE THE ONE MILD DAY AHEAD OF THE
FIRST SHOT OF COLDER AIR SLATED TO ARRIVE LATE IN THE DAY OR AT
NIGHT. THIS FIRST BOUNDARY WILL BE FAIRLY WEAK LEADING TO
TEMPERATURES ONLY A FEW DEGREES SHY OF CLIMO ON MONDAY...EVEN THOUGH
SOME 8 DEGREES COLDER THAN SUNDAY. DEEPENING MID LEVEL TROUGHINESS
AROUND HUDSON BAY VORTEX SENDS MUCH STRONGER SHOT OF COLD AIR
ADVECTION INTO THE SOUTHEAST MONDAY NIGHT. THERE IS STILL SOME
QUESTION AS TO THE ARCTIC CONTENT OF THE AIRMASS THAT FOLLOWS. THE
GFS FOR EXAMPLE HAS 850MB TEMPS RANGING FROM 0 TO -4C SOUTH TO NORTH
ACROSS THE REGION 00Z WED WHEREAS THE ECMWF (FROM 00Z) HAS -6 TO
-12C. THE CANADIAN IS CLOSER IN CAMP TO THE ECWMF IN SHOWING TRUE
ARCTIC AIR INVADING THE SOUTHEAST ALTHOUGH ITS PROGRESS IS SLIGHTLY
HELD UP BY A CLIPPER TYPE OF WAVE THAT MAY OR MAY NOT COME TO PASS.
CURRENT FORECAST WEIGHTED TOWARDS THE COLDER CONSENSUS.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
AS OF 00Z...PERIODS OF MVFR AND IFR WILL CONTINUE OVERNIGHT INTO THE
EARLY MORNING HOURS DUE TO REDUCED VISIBILITIES REGARDING PATCHY FOG
AND HEAVIER DOWNPOURS EARLY ON...FOLLOWED BY LOWERED CIGS. AFTER
DAYBREAK...VFR WILL PREVAIL AND CONTINUE THROUGH THE REMAINDER OF
THE VALID PERIOD.
CURRENT RADAR DEPICTS RAINFALL ACROSS THE ENTIRE AREA WITH QUITE THE
SCENARIO WITH A N-S WIND-DRIVEN LINE OF STORMS IN ASSOCIATION WITH A
LOW PRESSURE SYSTEM JUST ALONG THE COLD FRONT. AS A RESULT THERE ARE
A VARIETY OF WIND DIRECTIONS ACROSS THE AREA WITH WESTERLY WINDS AT
KFLO/KMYR/KCRE...AND EAST-NORTHEASTERLY WINDS AT KLBT/KILM. AS THIS
LINE CONTINUES TO PROPAGATE EAST NORTH-EAST AND TAPER OFF OVER THE
NEXT FEW HOURS...ALL WINDS WILL BECOME WESTERLY AOB 15 KTS WITH
GUSTS UP TO 25 KTS OVERNIGHT. AFTER MIDNIGHT...WIND DIRECTION WILL
CONTINUE TO VEER...BECOMING NORTHERLY AOB 15 KTS GUSTS 18-25 KTS
INTO THE MORNING HOURS. ANY RESIDUAL LOWERED CIGS FROM OVERNIGHT
WILL QUICKLY IMPROVE BY MORNING AS THE COLD FRONT PUSHES OUT OF THE
AREA. VFR WILL PREVAIL FOR THE REMAINDER OF THE PERIOD.
NORTH-NORTHEAST WINDS WILL CONTINUE THROUGHOUT THE DAY ON
FRIDAY...WITH GUSTS SUBSIDING INTO THE EARLY EVENING HOURS.
EXTENDED OUTLOOK...VFR THROUGH THE EXTENDED.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1000 PM THURSDAY...THE ONLY SIGNIFICANT CHANGE TO THE FORECAST
WAS TO RAISE SEA HEIGHTS BY 1-2 FEET BASED ON CURRENTLY REPORTED
WAVE OBSERVATIONS FROM THE FRYING PAN SHOALS BUOY...THE NEARSHORE
WRIGHTSVILLE BEACH BUOY...AND THE OCEAN CREST PIER WAVE GAUGE. WITH
THE COLD FRONT AND ATTENDANT LOW PRESSURE AREA NOW OFFSHORE WINDS
WILL BECOME NORTHERLY OVERNIGHT WITH GALE FORCE GUSTS REMAINING
POSSIBLE. PREVIOUS DISCUSSION FROM 630 PM FOLLOWS...
A COLD FRONT HAS SLID IN FROM THE NORTH AND LIES BETWEEN
WRIGHTSVILLE BEACH AND CAROLINA BEACH ALONG THE NORTH CAROLINA
COASTLINE. NORTHEAST WINDS NORTH OF THE BOUNDARY CONTRAST WITH SOUTH
WINDS ELSEWHERE. ANOTHER PORTION OF THE COLD FRONT IS QUICKLY
OVERTAKING FROM THE WEST...DRIVEN BY STRONG SURFACE LOW PRESSURE NOW
JUST NORTH OF MYRTLE BEACH. THIS LOW AND FRONT WILL SWEEP ACROSS THE
ENTIRE FORECAST AREA IN THE NEXT COUPLE OF HOURS...FOLLOWED BY GUSTY
WESTERLY WINDS THAT SHOULD TURN MORE NORTHERLY WITH TIME OVERNIGHT.
A GALE WARNING REMAINS IN EFFECT MORE FOR GUSTS THAN FOR SUSTAINED
WIND SPEEDS. THE STRONGEST WINDS ARE EXPECTED THIS EVENING WITH
CONVECTIVE SHOWERS ALONG THE FRONT...AND THEN AGAIN AFTER MIDNIGHT
AS THE LOW MOVES OFFSHORE AND COLD AIR POURS INTO THE REGION FROM
THE NORTH. SEAS SHOULD BUILD TO A VERY CHOPPY 4-6 FT WITH 7-FOOT
SEAS POSSIBLE WITHIN 20 MILES OF THE COAST NEAR CAPE FEAR.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 2 PM THURSDAY...THE GALE WILL LIKELY PERSIST INTO THE FIRST
FEW HOURS OF FRI...WITH A PERIOD OF SMALL CRAFT ADVISORY CONDITIONS
EXPECTED THEREAFTER. LOW PRESSURE WILL HAVE MOVED WELL AWAY FROM THE
AREA BY FRI MORNING...INTENSIFYING OFF THE SE NEW ENGLAND COAST. AT
THE SAME TIME...STRONG HIGH PRESSURE WILL BE CENTERED ACROSS THE
OHIO AND TENNESSEE VALLEYS. THE COMBINATION OF THESE TWO FEATURES
WILL CREATE A RATHER TIGHT PRESSURE GRADIENT ACROSS THE WATERS. WIND
SPEEDS WILL BE ON A STEADY DOWNWARD TREND DURING THE DAY ON FRI...
VEERING FROM N TO NE BY FRI EVE AND REMAINING FROM THE NNE OR NE
INTO SAT. WIND SPEEDS WILL CONTINUE TO DIMINISH WITH THE APPROACH OF
THE CENTER OF HIGH PRESSURE. WINDS WILL BECOME MORE WESTERLY SAT
NIGHT AS ANOTHER COLD FRONT APPROACHES FROM THE NW. SEAS WILL BE IN
THE PROCESS OF PEAKING FRI MORNING...IN THE RANGE OF 6 TO 9 FT WITH
PERHAPS 10 FT AT THE FRYING PAN SHOALS BUOY. WAVE HEIGHTS WILL
STEADILY SUBSIDE FRI AFTERNOON AND NIGHT WITH SEAS COMMONLY 2 TO 3
FT SAT AND SAT NIGHT.
LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 2 PM THURSDAY...OFFSHORE/WESTERLY WINDS ON SUNDAY WILL GET
VEERED ABOUT ABOUT A COMPASS POINT TO NW ASSOC WITH THE APPROACH OF
A COLD FRONT. A FURTHER TURN TO THE N LATER AT NIGHT WILL FOLLOW
FROPA BUT ANY INCREASE IN WIND SPEED AND THUS SEAS WILL BE MINIMAL.
THE WHOLE PROCESS IS THEN REPEATED BY THE APPROACH AND PASSAGE OF A
MORE VIGOROUS COLD FRONT MONDAY NIGHT. THIS BOUNDARY AND THE ENSUING
COLD SURGE COULD PUSH WIND AND/OR SEAS UP INTO SCEC REALM OR
POSSIBLY EVEN A SHORT LIVED ADVISORY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...GALE WARNING UNTIL 9 AM EST FRIDAY FOR AMZ250-252-254-256.
&&
$$
NEAR TERM...TRA
SHORT TERM...RJD
LONG TERM...MBB
AVIATION...SGL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
647 PM EST THU JAN 17 2013
.SYNOPSIS...
AN INTENSE AND QUICK MOVING AREA OF LOW PRESSURE WILL BRING
WIND...RAIN AND A RETURN TO CHILLY TEMPERATURES TONIGHT. THE
WINTER CHILL WILL PERSIST INTO THE WEEKEND AND THEN PERIODICALLY
BE REINFORCED BY SUCCESSIVE...DRY COLD FRONTS THROUGH MUCH OF
NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 630 PM THURSDAY...A POWERFUL UPPER LEVEL LOW IN NORTHWEST
GEORGIA WILL MOVE EAST-NORTHEASTWARD TONIGHT...SPREADING A VARIETY
OF WEATHER ACROSS THE CAROLINAS. SURFACE LOW PRESSURE OUT AHEAD OF
THE UPPER SYSTEM EXISTS UNDER THE STRONGEST UPPER LEVEL DIVERGENCE
AND COUPLED DEEP-LAYER ASCENT. A 100-MILE WIDE BAND OF MODERATE TO
HEAVY RAIN IS SWEEPING EAST RAPIDLY ACROSS THE AREA AND SHOULD BE
OFFSHORE EAST OF MYRTLE BEACH BY 8 PM...AND OFFSHORE EAST OF
WILMINGTON BY 10 PM. RAINFALL AMOUNTS WITHIN THIS BAND ARE AVERAGING
0.25 TO 0.50 INCHES PER HOUR. SCATTERED CONVECTIVE CELLS OUT AHEAD
OF THE MAIN RAIN BAND BRIEFLY DISPLAYED ROTATIONAL SIGNATURES THAT
REALLY CAUGHT OUR ATTENTION EARLIER...BUT THIS DEVELOPED AS THE
CELLS CROSSED NORTH OF A VERY PRONOUNCED FRONT THAT LIES FROM JUST
SOUTH OF WILMINGTON THROUGH JUST NORTH OF WHITEVILLE. A VERY STABLE
LOW-LEVEL ENVIRONMENT NORTH OF THE BOUNDARY KEPT POSSIBLE FUNNEL
CLOUDS FROM REACHING THE SURFACE. ADDITIONAL SHOWERS WITHIN THE
FRONTAL BAND ITSELF ARE TRANSPORTING DOWN 50-70 KNOT WINDS OBSERVED
ON THIS EVENING`S CHARLESTON SC WEATHER BALLOON FLIGHT JUST
3000-4000 FT OFF THE GROUND. DOWNED TREES HAVE BEEN REPORTED FROM A
NORTHERN HORRY COUNTY ALREADY.
ONCE THIS BAND OF MODERATE TO HEAVY RAIN SWEEPS OFFSHORE...PRECIP
CHANCES WILL FALL TREMENDOUSLY FOR THE REMAINDER OF TONIGHT FOR
ABOUT THE SOUTHERN TWO-THIRDS OF OUR FORECAST AREA WHICH INCLUDES
THE AREAS SOUTH OF FLORENCE...MARION...MYRTLE BEACH AND SOUTHPORT
WHERE A DRY...STABLE MID LEVEL ENVIRONMENT SHOULD PREVAIL. CLOSER TO
THE PATH THE STRONG UPPER LEVEL LOW IS EXPECTED TO TAKE...THE MID
LEVEL ENVIRONMENT WILL BE MUCH MORE MOIST AND LAPSE RATES WILL BE
MUCH STEEPER. THIS WILL KEEP PERIODS OF LIGHT RAIN GOING THROUGH
MIDNIGHT AND PERHAPS 2-3 AM FOR DARLINGTON...BENNETTSVILLE...
LUMBERTON...AND ELIZABETHTOWN.
THE BIG QUESTION IS HOW MUCH COLD AIR ARRIVES IN THE LOWER LEVELS
FOR A POSSIBLE CHANGEOVER TO SNOW IN OUR NORTHERN AREAS. EXAMINING
MODEL RH ON THE -8C TO -12C SURFACES THERE SHOULD BE DENDRITIC
CRYSTAL GROWTH UP IN THE CLOUDS UP BEGINNING AROUND 10 PM AND
LASTING THROUGH 2-3 AM FROM NORTH OF FLORENCE THROUGH ELIZABETHTOWN.
IN THE LOW LEVELS COLD AIR WILL BE THE LIMITED FACTOR. BASED ON THE
LATEST RUC AND 18Z NAM IT APPEARS SURFACE TEMPS OF 37/38 DEGREES
(IMPLYING AN ABOVE-FREEZING SURFACE-BASED LAYER NO DEEPER THAN 1500
FT) WILL ARRIVE AFTER 12 MIDNIGHT-1 AM...ALLOWING FOR A COUPLE HOURS
OF MIXED RAIN-SNOW BEFORE PRECIPITATION ENDS. QPF BY THIS TIME
SHOULD BE RATHER LIGHT AND WITH ABOVE FREEZING AIR TEMPS AND
WELL-ABOVE FREEZING SOIL TEMPS NO SNOW ACCUMULATIONS ARE EXPECTED. I
HAVE REMOVED SLEET FROM THE FORECAST AS THIS SHOULD ONLY BE A
RAIN-SNOW SCENARIO WITHOUT ANY POTENTIAL FOR MELTING ALOFT AND
REFREEZING.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 2 PM THURSDAY...WINTER IS BACK. IT WILL BE A CHILLY AND
BRISK START TO THE DAY FRI AS THE PRESSURE GRADIENT WILL REMAIN
RATHER TIGHT BETWEEN STRONG HIGH PRESSURE ACROSS THE OHIO AND
TENNESSEE VALLEYS AND LOW PRESSURE INTENSIFYING SE OF NEW ENGLAND.
THE GRADIENT WILL SLACKEN THROUGH THE AFTERNOON AND WIND
GUSTS...UP TO 25 TO 30 MPH...WILL DIMINISH. CHILLY TEMPS FRI
MORNING...ESPECIALLY IN COMPARISON TO RECENT DAYS...COUPLED WITH
THE WIND...WILL MAKE IT FEEL AS IF IT WERE IN THE MID 20S TO LOWER
30S. EVEN WITH BRIGHT SUNSHINE...TEMPS ARE NOT EXPECTED TO RISE
QUICKLY AS 850 MB TEMPS WILL START THE DAY JUST BELOW ZERO DEG.
PREVIOUS THINKING HAS NOT CHANGED AND WILL FORECAST HIGHS BELOW 50
DEGREES IN MOST PLACES...WITH MID 40S MOST COMMON. GOOD
RADIATIONAL COOLING IS EXPECTED FRI NIGHT AS HIGH PRESSURE REACHES
THE AREA. CLEAR SKIES AND VIRTUALLY CALM WIND WILL ALLOW EVE TEMPS
TO QUICKLY DROP AS DEWPOINTS DURING THIS TIME WILL BE WELL DOWN IN
THE 20S. OVERNIGHT LOWS ARE EXPECTED TO REACH THE MID AND UPPER
20S WITH SOME LOWER 20S WHERE RADIATIONAL COOLING MAXIMIZES
LONGEST.
CHILLY SURFACE HIGH PRESSURE WILL STILL BE IN PLACE ON SAT...BUT THE
WESTWARD EXTENT OF THE RIDGE WILL BEGIN TO BREAK DOWN DURING THE
AFTERNOON. SOME WEAK RETURN OF MILDER AIR AHEAD OF THE LEADING EDGE
OF THE NEXT COLD SURGE IS EXPECTED BY SAT AFTERNOON. THEREFORE...
THE SECOND HALF OF THE PERIOD SHOULD NOT BE AS CHILLY AND CLOSER TO
VALUES MORE TYPICAL OF MID JAN. WILL FORECAST HIGHS IN THE LOWER TO
MID 50S SAT. DEWPOINTS WILL BE CLIMBING THROUGH THE DAY SAT AND WITH
NIGHTFALL...TEMPS WILL NOT BE ABLE TO FALL AS RAPIDLY OR AS FAR AS
FRI NIGHT. DO NOT SEE A REASON TO STRAY TOO FAR FROM MODEL CONSENSUS
WHICH BRINGS LOWS TO THE MID AND UPPER 30S OVERNIGHT SAT.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 2 PM THURSDAY...THE LONG TERM APPEARS TO BE ENTIRELY RAIN-FREE
AND INCREASINGLY COLD. SUNDAY WILL BE THE ONE MILD DAY AHEAD OF THE
FIRST SHOT OF COLDER AIR SLATED TO ARRIVE LATE IN THE DAY OR AT
NIGHT. THIS FIRST BOUNDARY WILL BE FAIRLY WEAK LEADING TO
TEMPERATURES ONLY A FEW DEGREES SHY OF CLIMO ON MONDAY...EVEN THOUGH
SOME 8 DEGREES COLDER THAN SUNDAY. DEEPENING MID LEVEL TROUGHINESS
AROUND HUDSON BAY VORTEX SENDS MUCH STRONGER SHOT OF COLD AIR
ADVECTION INTO THE SOUTHEAST MONDAY NIGHT. THERE IS STILL SOME
QUESTION AS TO THE ARCTIC CONTENT OF THE AIRMASS THAT FOLLOWS. THE
GFS FOR EXAMPLE HAS 850MB TEMPS RANGING FROM 0 TO -4C SOUTH TO NORTH
ACROSS THE REGION 00Z WED WHEREAS THE ECMWF (FROM 00Z) HAS -6 TO
-12C. THE CANADIAN IS CLOSER IN CAMP TO THE ECWMF IN SHOWING TRUE
ARCTIC AIR INVADING THE SOUTHEAST ALTHOUGH ITS PROGRESS IS SLIGHTLY
HELD UP BY A CLIPPER TYPE OF WAVE THAT MAY OR MAY NOT COME TO PASS.
CURRENT FORECAST WEIGHTED TOWARDS THE COLDER CONSENSUS.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
AS OF 00Z...PERIODS OF MVFR AND IFR WILL CONTINUE OVERNIGHT INTO THE
EARLY MORNING HOURS DUE TO REDUCED VISIBILITIES REGARDING PATCHY FOG
AND HEAVIER DOWNPOURS EARLY ON...FOLLOWED BY LOWERED CIGS. AFTER
DAYBREAK...VFR WILL PREVAIL AND CONTINUE THROUGH THE REMAINDER OF
THE VALID PERIOD.
CURRENT RADAR DEPICTS RAINFALL ACROSS THE ENTIRE AREA WITH QUITE THE
SCENARIO WITH A N-S WIND-DRIVEN LINE OF STORMS IN ASSOCIATION WITH A
LOW PRESSURE SYSTEM JUST ALONG THE COLD FRONT. AS A RESULT THERE ARE
A VARIETY OF WIND DIRECTIONS ACROSS THE AREA WITH WESTERLY WINDS AT
KFLO/KMYR/KCRE...AND EAST-NORTHEASTERLY WINDS AT KLBT/KILM. AS THIS
LINE CONTINUES TO PROPAGATE EAST NORTH-EAST AND TAPER OFF OVER THE
NEXT FEW HOURS...ALL WINDS WILL BECOME WESTERLY AOB 15 KTS WITH
GUSTS UP TO 25 KTS OVERNIGHT. AFTER MIDNIGHT...WIND DIRECTION WILL
CONTINUE TO VEER...BECOMING NORTHERLY AOB 15 KTS GUSTS 18-25 KTS
INTO THE MORNING HOURS. ANY RESIDUAL LOWERED CIGS FROM OVERNIGHT
WILL QUICKLY IMPROVE BY MORNING AS THE COLD FRONT PUSHES OUT OF THE
AREA. VFR WILL PREVAIL FOR THE REMAINDER OF THE PERIOD.
NORTH-NORTHEAST WINDS WILL CONTINUE THROUGHOUT THE DAY ON
FRIDAY...WITH GUSTS SUBSIDING INTO THE EARLY EVENING HOURS.
EXTENDED OUTLOOK...VFR THROUGH THE EXTENDED.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 630 PM THURSDAY...A COLD FRONT HAS SLID IN FROM THE NORTH AND
LIES BETWEEN WRIGHTSVILLE BEACH AND CAROLINA BEACH ALONG THE NORTH
CAROLINA COASTLINE. NORTHEAST WINDS NORTH OF THE BOUNDARY CONTRAST
WITH SOUTH WINDS ELSEWHERE. ANOTHER PORTION OF THE COLD FRONT IS
QUICKLY OVERTAKING FROM THE WEST...DRIVEN BY STRONG SURFACE LOW
PRESSURE NOW JUST NORTH OF MYRTLE BEACH. THIS LOW AND FRONT WILL
SWEEP ACROSS THE ENTIRE FORECAST AREA IN THE NEXT COUPLE OF
HOURS...FOLLOWED BY GUSTY WESTERLY WINDS THAT SHOULD TURN MORE
NORTHERLY WITH TIME OVERNIGHT. A GALE WARNING REMAINS IN EFFECT MORE
FOR GUSTS THAN FOR SUSTAINED WIND SPEEDS. THE STRONGEST WINDS ARE
EXPECTED THIS EVENING WITH CONVECTIVE SHOWERS ALONG THE FRONT...AND
THEN AGAIN AFTER MIDNIGHT AS THE LOW MOVES OFFSHORE AND COLD AIR
POURS INTO THE REGION FROM THE NORTH. SEAS SHOULD BUILD TO A VERY
CHOPPY 4-6 FT WITH 7-FOOT SEAS POSSIBLE WITHIN 20 MILES OF THE COAST
NEAR CAPE FEAR.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 2 PM THURSDAY...THE GALE WILL LIKELY PERSIST INTO THE FIRST
FEW HOURS OF FRI...WITH A PERIOD OF SMALL CRAFT ADVISORY CONDITIONS
EXPECTED THEREAFTER. LOW PRESSURE WILL HAVE MOVED WELL AWAY FROM THE
AREA BY FRI MORNING...INTENSIFYING OFF THE SE NEW ENGLAND COAST. AT
THE SAME TIME...STRONG HIGH PRESSURE WILL BE CENTERED ACROSS THE
OHIO AND TENNESSEE VALLEYS. THE COMBINATION OF THESE TWO FEATURES
WILL CREATE A RATHER TIGHT PRESSURE GRADIENT ACROSS THE WATERS. WIND
SPEEDS WILL BE ON A STEADY DOWNWARD TREND DURING THE DAY ON FRI...
VEERING FROM N TO NE BY FRI EVE AND REMAINING FROM THE NNE OR NE
INTO SAT. WIND SPEEDS WILL CONTINUE TO DIMINISH WITH THE APPROACH OF
THE CENTER OF HIGH PRESSURE. WINDS WILL BECOME MORE WESTERLY SAT
NIGHT AS ANOTHER COLD FRONT APPROACHES FROM THE NW. SEAS WILL BE IN
THE PROCESS OF PEAKING FRI MORNING...IN THE RANGE OF 6 TO 9 FT WITH
PERHAPS 10 FT AT THE FRYING PAN SHOALS BUOY. WAVE HEIGHTS WILL
STEADILY SUBSIDE FRI AFTERNOON AND NIGHT WITH SEAS COMMONLY 2 TO 3
FT SAT AND SAT NIGHT.
LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 2 PM THURSDAY...OFFSHORE/WESTERLY WINDS ON SUNDAY WILL GET
VEERED ABOUT ABOUT A COMPASS POINT TO NW ASSOC WITH THE APPROACH OF
A COLD FRONT. A FURTHER TURN TO THE N LATER AT NIGHT WILL FOLLOW
FROPA BUT ANY INCREASE IN WIND SPEED AND THUS SEAS WILL BE MINIMAL.
THE WHOLE PROCESS IS THEN REPEATED BY THE APPROACH AND PASSAGE OF A
MORE VIGOROUS COLD FRONT MONDAY NIGHT. THIS BOUNDARY AND THE ENSUING
COLD SURGE COULD PUSH WIND AND/OR SEAS UP INTO SCEC REALM OR
POSSIBLY EVEN A SHORT LIVED ADVISORY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...GALE WARNING UNTIL 9 AM EST FRIDAY FOR AMZ250-252-254-256.
&&
$$
NEAR TERM...TRA
SHORT TERM...RJD
LONG TERM...MBB
AVIATION...SGL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
310 PM EST WED JAN 16 2013
.SYNOPSIS...
DEEP LAYER HIGH PRESSURE TONIGHT WILL GIVE WAY TO A PERIOD OF
WIND AND RAIN WITH THE BRUNT OF THE UNSETTLED WEATHER ARRIVING
LATER THURSDAY AFTERNOON AND INTO THURSDAY NIGHT. NEAR RECORD
WARMTH WILL BE REPLACED BY A WINTER CHILL BEGINNING LATE THURSDAY
NIGHT AND PERSISTING THROUGH THE WEEKEND AND EARLY NEXT WEEK AS
COLD AIR IS REINFORCED BY SUCCESSIVE COLD FRONT.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
AS OF 3 PM WEDNESDAY...HAVE TWEAKED THE OVERCAST SKIES TO THE
EAST SLIGHTLY BASED ON MOST RECENT SATELLITE TRENDS. RUC CONTINUES
TO SHOW THE COAST REMAINING CLEAR FOR THE NEXT FEW HOURS AND IT
WOULD APPEAR CLOUD COVER WILL BE MORE UPDATE CENTRIC FOR THE NEAR
TERM.
WATER VAPOR IMAGERY SHOWING ESSENTIALLY THE SAME PATTERN AS WE
HAVE OBSERVED FOR DAYS NOW...A PLUME OF MOISTURE MOVING ACROSS THE
TENNESSEE/MISSISSIPPI VALLEY WITH DRY AIR MOVING IN ALONG THE
SOUTHEAST COAST. MID LEVEL PATTERN WILL BE CHANGING DRAMATICALLY
OVER THE NEXT FEW DAYS BUT NOT NECESSARILY THROUGH 1200 UTC
THURSDAY. IN FACT...ONLY WEAK FORCING...LOW LEVEL FRONTOGENESIS IS
ADVERTISED BY THE MAJOR MODELS THROUGH THROUGH THURSDAY MORNING
ACROSS OUR WESTERN AREAS AND HAVE TRENDED BACK MINIMAL POP VALUES.
GUIDANCE ALSO SHOWS OVERCAST SKIES/BOUNDARY WAVERING IN PLACE
THROUGH THE OVERNIGHT HOURS WITHOUT MOVING A LOT. FINALLY...WARMER
GFS MAV NUMBERS SEEM A SAFE BET BASED ON PERSISTENCE FOR OVERNIGHT
LOWS.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
AS OF 3 PM WEDNESDAY...TEMPERATURES MORE TYPICAL OF WINTER WILL
RETURN TO THE AREA DURING THIS PERIOD. IN FACT...FOR THE FIRST
TIME SINCE JAN 5-6...TEMPS WILL BE BELOW NORMAL.
A COLD FRONT WILL CONTINUE ITS DRIFT TOWARD THE AREA INTO THU. AN
AREA OF LOW PRESSURE WILL DEVELOP IN RESPONSE TO APPROACHING
SHORTWAVE ENERGY. UNTIL THIS LOW MOVES OVERHEAD AND THEN NE OF THE
AREA...THE EASTERN CAROLINAS WILL REMAIN LARGELY IN THE WARM SECTOR.
TEMPS WILL BE TRICKY ON THU GIVEN THE PROXIMITY OF THE COLD FRONT
AND THICKENING CLOUDS AND EVENTUALLY THE ONSET OF RAIN. AT THIS
TIME...EXPECT A RATHER TIGHT TEMP GRADIENT WITH THU AFTERNOON HIGHS
RANGING FROM AROUND 60 DEGREES ACROSS THE NW CORNER OF THE FORECAST
AREA TO LOWER AND MID 70S ACROSS MOST OF THE AREA ALONG AND S OF A
LINE FROM NEAR BURGAW TO WHITEVILLE TO DILLON TO DARLINGTON. THIS
TIGHT GRADIENT COLD EASILY BE A LITTLE FURTHER N OR S OF THIS
POSITION...SO THE HIGH TEMPS ON THU MAY CHANGE WITH LATER FORECASTS.
WHAT IS A VIRTUAL SLAM DUNK IS A PERIOD OF RAIN...ESPECIALLY LATER
THU AND THU EVE DUE TO CONTRIBUTIONS FROM INSTABILITY ALONG THE
FRONT...PVA...UPPER DIFFLUENCE IN THE VICINITY OF THE STRONG UPPER
JET AND LIFT ASSOCIATED WITH AN AREA OF STRENGTHENING LOW PRESSURE.
THE LAYER OF SATURATION INCREASES TO ABOUT 17 KFT AND PRECIPITABLE
WATER VALUES CLIMB TO ONE AND ONE-HALF INCHES. THUS A PERIOD OF
MODERATE TO HEAVY RAIN IS EXPECTED...ESPECIALLY DURING THE EVENING
HOURS OF THU. AS THE AREA OF LOW PRESSURE MOVES BY...COLD AIR WILL
GET DRAWN INTO THE EASTERN CAROLINAS AS THE COLD FRONT SURGES S. AT
THE SAME TIME THE COLD AIR IS ARRIVING...THE COLUMN WILL BE RAPIDLY
DRYING AND IT LOOKS AS THOUGH THE RAIN WILL END BEFORE IT HAS A
CHANCE TO CHANGEOVER OR MIX WITH A BRIEF PERIOD OF SNOW AS THE
CRITICAL DENDRITIC GROWTH ZONE IS THE FIRST TO DRY OUT.
WE ARE FORECASTING ALL RAIN ACROSS THE ILM FORECAST AREA AND THE
WINTER WEATHER TOP DOWN METHODOLOGY WAS APPLIED TO PRODUCE THIS
FORECAST. ANY SNOW WITH THIS SYSTEM WILL REMAIN N AND NW OF THE AREA
AND THERE WILL LIKELY BE SOME ACCUMULATION OF SNOW ACROSS THE
NORTHERN 2/3RDS OR SO OF NORTH CAROLINA. RAINFALL AMOUNTS OF 1/2 TO
1 INCH WILL BE MOST COMMON...HOWEVER SOME AREAS MAY RECEIVE SLIGHTLY
MORE QPF...WITH THE HIGHEST PROBABILITY FOR THIS ACROSS THE CAPE
FEAR RIVER BASIN. OTHER AREAS MAY RECEIVE SLIGHTLY LESS QPF...WITH
THE HIGHEST PROBABILITY ACROSS THE SOUTHERN GRAND STRAND AND
GEORGETOWN.
DEVELOPING CAA IN THE WAKE OF DEPARTING AND INTENSIFYING LOW
PRESSURE WILL ALLOW THE PRESSURE GRADIENT TO TIGHTEN AND WIND GUSTS
TO AROUND 30 MPH ARE EXPECTED THU NIGHT. 850 MB TEMPS WILL DROP TO
AROUND MINUS 2 DEG C BY FRI MORNING. LOWS BY FRI MORNING WILL BE
WELL DOWN IN THE 30S...AND NW PORTIONS OF THE FORECAST AREA WILL BE
CLOSE TO FREEZING FRI MORNING. TEMPS WILL STRUGGLE EVEN WITH BRIGHT
SUNSHINE ON FRI...AND THE FORECAST TEMP PROFILES SUGGEST TEMPS WILL
NEVER REACH 50 IN MOST LOCATIONS WITH MID 40S MOST COMMON.
AS HIGH PRESSURE POSITIONS ITSELF OVERHEAD...IT WILL BE COLD FRI
NIGHT...CLEAR SKIES AND LIGHT TO CALM WINDS WILL QUICKLY DRIVE TEMPS
INTO THE 20S AND AS LOW AS THE LOWER 20S IN THOSE AREAS WHERE
RADIATIONAL COOLING IS MAXIMIZED LONGEST.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 3 PM WEDNESDAY...WEAKENING SURFACE HIGH PRESSURE AND ZONAL MID
LEVEL FLOW IN PLACE OVER THE WEEKEND. TEMPERATURES WILL BE QUITE
CLOSE TO CLIMO AND AMPLE SUNSHINE EXPECTED. A SERIES OF
MOISTURE-DEPRIVED COLD FRONTS WILL MARCH SOUTHWARD ACROSS THE AREA
EARLY NEXT WEEK. THE FIRST COMES THROUGH LATE SUNDAY OR SUNDAY
NIGHT. THE SECOND STRONGER PUSH COMES MONDAY NIGHT. TEMPS WILL THUS
FALL A LITTLE BELOW CLIMO BY MONDAY WHEREAS THE BALANCE OF THE LONG
TERM WILL BRING SOME DOWNRIGHT COLD WEATHER WITH HIGHS STUCK IN THE
40S AND LOWS LOWER 20S. NATURALLY THERE IS SOME DISAGREEMENT BETWEEN
VARIOUS MODELS REGARDING THE MAGNITUDE OF THE COLD SO FAR OUT IN
TIME.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 18Z...TRICKY FORECAST ALONG THE COAST WITH SEA FOG LURKING.
THINK WIND TRAJECTORY WILL KEEP IT JUST OFFSHORE THROUGH THE
AFTERNOON HOURS...BUT AS THE WIND DIES AFTER SUNSET LOOK FOR THE
STRATUS TO MOVE BACK IN...FIRST AT THE MYRTLES AND LATER AT ILM.
EVENTUALLY LBT AND FLO WILL GO DOWN WITH ALL THE LOW LEVEL
MOISTURE IN PLACE. WINDS MAY STAY ABOVE 5 KTS TONIGHT...WHICH
COULD HELP TO KEEP VISIBILITIES UP A BIT MORE THAN LAST NIGHT.
THURSDAY...FRONTAL SYSTEM APPROACHES...BUT ANY RAIN WILL HOLD OFF
UNTIL AFTER THE END OF THE FORECAST PERIOD. WINDS WILL SHIFT MORE
SOUTH SOUTHEASTERLY...WITH A TROUGH INLAND.
EXTENDED OUTLOOK...RAIN/MVFR/IFR LIKELY THURSDAY INTO EARLY FRIDAY.
VFR DEVELOPING FRIDAY AND PERSISTING THROUGH MONDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM WEDNESDAY...A RELATIVELY BENIGN SOUTHWESTERLY FLOW OF
10-15 KNOTS WILL CONTINUE THROUGH THE PERIOD. INITIALLY BUOY
OBSERVATIONS SHOW VALUES CLOSER TO THE LOWER END OF THE RANGE WITH
41013 NOW AT NINE KNOTS. JMPN7 IS MUCH HIGHER THANKS TO SEA BREEZE
AFFECTS AT 22 KNOTS. SWELL ENERGY HAS ALL BUT DISSIPATED AND
WAVEWATCH SHOWS THIS TREND REMAINS INTACT FOR THE NEXT 12-18
HOURS. SIGNIFICANT SEAS OF 2-4 FEET CAN BE EXPECTED.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 PM WEDNESDAY...A GALE WATCH HAS BEEN ISSUED FOR ALL WATERS
FOR LATER THU AFTERNOON AND THROUGH THE DAY ON FRI. THE STRONGEST
WINDS AND HIGHEST SEAS ARE EXPECTED THU NIGHT. WINDS ARE EXPECTED TO
AT LEAST REACH GALE FORCE IN GUSTS WITH THE BEST CHANCE FOR
SUSTAINED WINDS TO GALE FORCE ACROSS THE NORTHERN WATERS...ON THE
BACK SIDE OF AN INTENSIFYING AND DEPARTING AREA OF LOW PRESSURE.
WINDS WILL BE FROM A SOUTHERLY DIRECTION THU...SHIFTING TO W AND
THEN NW THU EVE AS A COLD FRONT SURGES ACROSS THE WATERS. NW WINDS
WILL VEER TO N OVERNIGHT THU WITH N WINDS ON FRI VEERING TO NE FRI
NIGHT AS THE CENTER OF HIGH PRESSURE APPROACHES. SEAS WILL REACH UP
TO 7 TO 9 FT THU NIGHT. SEAS WILL SUBSIDE THROUGH THE DAY ON FRI AND
THIS TREND WILL PERSIST FRI NIGHT.
LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 3 PM WEDNESDAY...EAST-WEST ELONGATED HIGH PRESSURE WITH AXIS
RIGHT ACROSS THE REGION TO KEEP WINDS QUITE LITE ON SATURDAY. SEAS
WILL QUICKLY SETTLE DOWN TO ABOUT 2 FT. AT THE START OF THE PERIOD
THERE MAY STILL BE A LINGERING SWELL YIELDING A NEARSHORE/OFFSHORE
GRADIENT IN SEA HEIGHT BUT THE OVERALL TREND WILL BE FOR SEAS TO
DIMINISH. SAT NIGHT INTO SUNDAY THE AXIS OF THE RIDGE WILL BOTH SINK
TO THE SOUTH AND ALSO PRETTY MUCH WASH OUT. THIS WILL TURN THE FLOW
BACK TO AN OFFSHORE DIRECTION. SEAS WILL REMAIN QUITE SMALL IN THE
ABSENCE OF ANY APPRECIABLE CHANGE IN WIND SPEEDS. A FAIRLY WEAK COLD
FRONT PUSHES THROUGH SUNDAY NIGHT TURNING WIND TO THE NORTH. THIS
BOUNDARY WILL BE FOLLOWED BY A STRONGER ONE THAT MAY LEAD TO QUITE A
SURGE IN WIND AND SEAS BY THE VERY END OF THE PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...GALE WATCH FROM THURSDAY AFTERNOON THROUGH FRIDAY AFTERNOON
FOR AMZ250-252-254-256.
&&
$$
SYNOPSIS...SHK
NEAR TERM...SHK
SHORT TERM...RJD
LONG TERM...MBB
AVIATION...SHK/DL
AREA FORECAST DISCUSSION
NWS BISMARCK ND
330 PM CST WED JAN 16 2013
.SHORT TERM...TONIGHT THROUGH THURSDAY NIGHT...
THE MAIN CHALLENGE OF THE SHORT TERM WILL BE THE TIMING AND
INTENSITY OF PRECIPITATION THROUGH THURSDAY NIGHT.
RADAR RETURNS AT 20Z CONTINUE TO SHOW THE TREND OF DIMINISHING LIGHT
SNOW ACROSS PORTIONS OF THE EAST...WHILE THE WEST AND SOUTHWEST
REMAIN QUIET. THE LATEST RUN OF THE RAP AND THE 12Z NAM HAVE
INITIALIZED POORLY WHEN TAKING A LOOK AT CURRENT TRENDS. RADAR
RETURNS SUPPORT DIMINISHING LIGHT SNOW ACROSS MY EAST...HOWEVER IT
DOES NOT SUPPORT THE AREA OF PRECIPITATION ACROSS MY WEST AND
SOUTHWEST. AS A RESULT...HAVE OPTED TO BRING DOWN POPS/QPF
ESPECIALLY ACROSS THE SOUTHWEST AND WEST AND MENTIONED FLURRIES IN
THE WEATHER GRIDS.
ANOTHER IMPULSE WILL ENTER THE AREA THURSDAY AFTERNOON FROM THE
SOUTHERN MANITOBA AND SASKATCHEWAN AND MOVE SOUTHEAST ACROSS THE
NORTHWEST TO SOUTHEAST ORIENTED BAROCLINIC ZONE SET UP OVER NORTH
DAKOTA...GENERATING ANOTHER ROUND OF PRECIPITATION ACROSS NORTHERN
PORTIONS OF CENTRAL NORTH DAKOTA. PRECIPITATION TYPE SHOULD REMAIN
ALL SNOW AS MODEL SOUNDINGS FORECAST A TEMPERATURE PROFILE THAT
REMAINS BELOW FREEZING. SNOW ACCUMULATIONS ARE EXPECTED TO BE LIGHT
AND UNDER AN INCH.
.LONG TERM...FRIDAY THROUGH WEDNESDAY...
THE HIGHLIGHT OF THE EXTENDED FORECAST CONTINUES TO BE A POTENTIAL
ARCTIC SURGE SATURDAY INTO EARLY NEXT WEEK.
ONE LAST MILD DAY IS FORECAST ACROSS WESTERN AND CENTRAL NORTH
DAKOTA ON FRIDAY AS THE LOW LEVEL BAROCLINIC ZONE BENEATH THE POLAR
JET SHIFTS NORTHEAST WITH THE APPROACH OF THE NEXT CLIPPER SYSTEM.
WITH WESTERLY DOWNSLOPING WINDS OF 15-20 KTS...WIDESPREAD HIGHS IN
THE 30S ARE ANTICIPATED...WHICH MAY BE A BIT LOW FOR A FEW PLACES AS
THE SNOWPACK CONTINUES TO THIN. IN GENERAL...FOLLOWED A BLEND OF THE
DETERMINISTIC MODELS...AVOIDING THE NAM WHICH HAS SHOWN POOR
TEMPERATURE VERIFICATION AS OF LATE ON DAY 3.
FOR SATURDAY...THE AFOREMENTIONED CLIPPER PROPAGATES SOUTHEAST WITH
AN ASSOCIATED VERY STRONG COLD FRONT THAT WILL MARK THE BEGINNING OF
WHAT COULD BE THE COLDEST AIRMASS OF THE SEASON THUS FAR. WITH A
RATHER MILD CONDITIONS THROUGH FRIDAY NIGHT WITH LOW LEVEL MIXING
AHEAD OF THE FRONT...TEMPERATURES ARE LIKELY TO FALL THROUGH THE
ENTIRE DAY ACROSS THE AREA BEHIND THE FRONT. THE OTHER CONCERN FOR
SATURDAY IS THE STRONG WIND POTENTIAL. WHILE VERY STRONG ISALLOBARIC
FORCING IS FORECAST BEHIND THE FRONT WITH 15-20MB/6 HR PRESSURE
RISES WITH STRONG LOW LEVEL COLD AIR ADVECTION...THE BIG QUESTION
ONCE AGAIN IS LOW LEVEL LAPSES RATES AND HOW HIGH MOMENTUM CAN BE
TRANSFERRED FROM....WHICH IS VARIED AMONGST THE DETERMINISTIC MODELS.
WHILE WIND ADVISORY LEVEL GUSTS ARE PROBABLE GIVEN CURRENT
TRENDS...SHOULD NEAR ADIABATIC LAPSE RATES BE ESTABLISHED THROUGH
850 MB...50+ KTS COULD BE MIXED TO THE SURFACE.
THE OVERALL 12 UTC GUIDANCE SUITE IS IN GOOD AGREEMENT IN THE
DEVELOPMENT OF A HIGH AMPLITUDE UPPER LEVEL RIDGE ALONG THE PACIFIC
COAST AND INTO THE ARCTIC THROUGH SUNDAY AND INTO NEXT WEEK...WHICH
SHOULD ALLOW VERY COLD ARCTIC AIR TO BE TRANSPORTED SOUTH UNDER DEEP
CYCLONIC FLOW ALOFT. THE COLDEST TIMEFRAME APPEARS TO BE SUNDAY
THROUGH MONDAY NIGHT AS A NEAR 1045 MB SURFACE HIGH ON THE
DETERMINISTIC MODELS BRINGS A REINFORCING SHOT OF COLD AIR TO THE
AREA.GIVEN GOOD AGREEMENT...WILL UTILIZE A BLEND OF THE
GUIDANCE...WHICH RESULTS IN WIDESPREAD LOWS SUNDAY NIGHT OF -15 TO
-25 WITH SUB-ZERO DAYTIME HIGHS ON MONDAY. WIND CHILL TEMPERATURES
COLDER THAN -40 ARE NOT OUT OF THE QUESTION. SHOULD TRENDS
CONTINUE...A WIND CHILL WATCH MAY BE NECESSARY. THE QUESTION BECOMES
LATE MONDAY AND INTO TUESDAY OF WHETHER THE LOW LEVEL ARCTIC AIRMASS
CAN SCOURED OUT...OR IF WARMING AHEAD OF LEE TROUGHING WILL NOT BE
REALIZED AT THE SURFACE. THE 12 UTC GFS APPEARING TO BE THE MOST
AGGRESSIVE AT GETTING RID OF THE ARCTIC AIR...WHICH IS QUESTIONABLE
COMPARED TO ITS OWN ENSEMBLE MEAN AND THE GEM/ECMWF.
&&
.AVIATION...
AS OF 21 UTC...A COLD FRONT WAS LOCATED FROM KISN THROUGH KBIS AND
KABR. THIS FRONT SHOULD SOON STALL OUT ACROSS SOUTHWEST NORTH
DAKOTA. SNOW FROM THIS MORNING HAS GENERALLY
DISSIPATED...HOWEVER...ISOLATED VERY LIGHT SNOW SHOWERS ARE STILL
POSSIBLE THROUGH 00 UTC. THE PREDOMINANT FLIGHT CATEGORY ACROSS
WESTERN AND CENTRAL NORTH DAKOTA THROUGH THE AFTERNOON AND MUCH OF
THE NIGHT SHOULD BE MVFR IN STRATUS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...HUBER
LONG TERM/AVIATION...AYD
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
1011 AM CST WED JAN 16 2013
.DISCUSSION...
OVERALL...FORECAST IS IN GOOD SHAPE. ADJUSTED HIGHEST POPS A BIT
FARTHER SOUTH ALONG BAND OF LIGHT SNOW STRETCHING FROM BOTTINEAU
TO BETWEEN FARGO AND WAHPETON. THIS AREA OF SNOW EXPECTED TO SAG
SOUTH AND EAST THROUGH THE DAY ALONG STRONGEST MID-LEVEL THERMAL
GRADIENT. ACCUMULATIONS SHOULD BE AN INCH OR LESS. SNOW SHOULD
EXIT THE FORECAST AREA BY 00 UTC TONIGHT.
SURFACE COLD FRONT HAS MOVED SOUTH AND WEST OF THE FORECAST AREA
AND WITH STRONG COLD AIR ADVECTION...EXPECT TEMPERATURES TO FALL
THROUGH THE DAY. MOST LOCATIONS NORTH OF THE HIGHWAY 2 CORRIDOR
WILL FALL BELOW ZERO BY 6 PM THIS EVENING. AFTERNOON BOUNDARY
LAYER DEEPENS TO BETWEEN 900 AND 950 HPA WITH AROUND 20 KTS TO MIX
TO THE SURFACE...SO WILL SEE NORTHERLY WIND FROM 10 TO 15 MPH.
SHOULD SEE SOME GRADUAL CLEARING ACROSS THE NORTHEAST LATE IN THE
DAY... BUT DID INCREASE SKY COVER THIS MORNING AND EARLY AFTERNOON
REGION- WIDE GIVEN UPSTREAM CLOUD COVER.
&&
.AVIATION...
CIGS SHOULD IMPROVE AS IFR/MVFR CONDITIONS ERODE WITH DRIER
NORTHERLY WINDS AT ALL TAF SITES. ANY STRONG GUSTS THIS MORNING
WILL DIMINISH DURING THE LATER HALF OF THE DAY WITH SFC HIGH
BUILDING IN TO THE REGION. SNOW BAND MAY CLIP THE DVL AND FAR TAF
SITES THROUGH EARLY AFTN...MAY CAUSE VSBY/CIGS TO DROP FOR A
BRIEF PERIOD.
&&
.PREV DISCUSSION... /ISSUED 636 AM CST WED JAN 16 2013/
UPDATE...
UPDATED FOR A EASTWARD TREND OF -SN ACROSS THE LANGDON TO GFK TO
PARK RAPIDS LINE. ALSO COOLED TEMPS THIS MORNING ACROSS THE NORTH
AS TEMPS IN THE SINGLE DIGITS ENTERING INT EH NORTHERN VALLEY
ALREADY. LATEST RAP MODEL RUN HANDLED THESE TRENDS VERY WELL USED
IT FOR THE REST OF THE MORNING AND INTO EARLY AFTN OF PCPN
PLACEMENT.
PREV DISCUSSION... /ISSUED 340 AM CST WED JAN 16 2013/
SHORT TERM...
THE CHALLENGES FOR THE FORECAST THIS MORNING INCLUDE THE TIMING OF
FRONTAL PASSAGES AND ASSOCIATED PCPN/CLOUD COVER AND AND ITS
EFFECT ON TEMPERATURES. MODELS IN REASONABLE AGREEMENT WITH GENERAL
FEATURES THROUGH THE END OF THE WEEK AND WILL USE A BLEND FOR THE
FORECAST PACKAGE.
COLD FRONT CURRENTLY PUSHING ACROSS THE CWFA WITH A STRONG PUSH OF
CAA IN ITS WAKE. AHEAD OF THE WIND SHIFT TO THE NORTH TEMPS HAVE
PUSHED INTO THE MID 30S VALLEY AND WEST. SAFE TO SAY TODAYS HIGHS
HAVE BEEN REACHED AND TEMPS WILL FALL FOR THE REST OF THE DAY AS
925MB TEMPS DROP 10 TO 20 C BY 00Z THURS. SOME -SN IS LIKELY ACROSS
THE SW PORTION OF THE CWFA AS A WEAK IMPULSE MOVES SE ALONG THE
BAROCLINIC ZONE AND UNDER THE 300MB RIGHT EXIT REGION. EXPECT AN
INCH OR TWO ALONG AND SOUTH OF A LINE FROM DVL TO W CASS TO ELBOW
LAKE.
SFC HIGH PRESSURE SLIDES ACROSS THE REGION TONIGHT AND TEMPS WILL
BE HIGHLY DEPENDENT ON CLOUD COVER WITH THE COLDEST VALUES
EXPECTED ACROSS THE NW MN... NEAR ZERO IN THE FAR WEST TO ALMOST
20 BELOW IN THE N RRV AND ROX TO BDE AREAS. A SLOW RECOVERY
EXPECTED THURSDAY AS WEAK MIXING AND THE COLD COLUMN LIMIT
WARMING.
RETURN FLOW AHEAD OF THE NEXT SW IN THE NW FLOW BEGINS THURSDAY PM
AND SHOULD LIMIT TEMP DROP OFF ACROSS E ND AS CLOUDS/-SN IN THE
WAA MOVES INTO THE FA. SFC LOW TRACK ALONG AND SOUTH OF THE
INTERNATIONAL BORDER WILL KEEP BEST CHC FOR -SN ALONG THE
INTERNATIONAL BORDER AREAS TO BEMIDJI FRIDAY WITH WEST WINDS
ALLOWING FOR SOME WARMING ACROSS SE ND FRIDAY AFTN. COLD FRONT
PUSHES THROUGH OVERNIGHT WITH FALLING TEMPS EXPECTED DURING THE
DAY SATURDAY.
LONG TERM (SAT-TUE)... A COLD PERIOD COMING UP AS ALL LONG RANGE
MODELS SHOW THE POLAR LOW OVER HUDSON BAY. SEVERAL SHORT WAVES
WILL CONTINUE TO MOVE SOUTHEAST...ONE WILL MOVE THRU SUNDAY
FOLLOWED BY HIGH PRESSURE AND LIKELY THE COLDEST OF THE AIRMASSES
THIS WINTER SEASON FOR SUN NIGHT INTO TUESDAY. EXPECT TEMPS TO
REMAIN BLO ZERO SUN-TUE. WITH HIGH OVERHEAD AND LIKELY A CLEAR
SKY SHOULD HAVE WIDESPREAD -20S SUN NIGHT AND AGAIN MON
NIGHT...COLDEST IN THE NORTH AND EASTERN PARTS OF THE FCST AREA.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
ROGERS/JK
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
636 AM CST WED JAN 16 2013
.UPDATE...
UPDATED FOR A EASTWARD TREND OF -SN ACROSS THE LANGDON TO GFK TO
PARK RAPIDS LINE. ALSO COOLED TEMPS THIS MORNING ACROSS THE NORTH
AS TEMPS IN THE SINGLE DIGITS ENTERING INT EH NORTHERN VALLEY
ALREADY. LATEST RAP MODEL RUN HANDLED THESE TRENDS VERY WELL USED
IT FOR THE REST OF THE MORNING AND INTO EARLY AFTN OF PCPN
PLACEMENT.
&&
.PREV DISCUSSION... /ISSUED 340 AM CST WED JAN 16 2013/
SHORT TERM...
THE CHALLENGES FOR THE FORECAST THIS MORNING INCLUDE THE TIMING OF
FRONTAL PASSAGES AND ASSOCIATED PCPN/CLOUD COVER AND AND ITS
EFFECT ON TEMPERATURES. MODELS IN REASONABLE AGREEMENT WITH GENERAL
FEATURES THROUGH THE END OF THE WEEK AND WILL USE A BLEND FOR THE
FORECAST PACKAGE.
COLD FRONT CURRENTLY PUSHING ACROSS THE CWFA WITH A STRONG PUSH OF
CAA IN ITS WAKE. AHEAD OF THE WIND SHIFT TO THE NORTH TEMPS HAVE
PUSHED INTO THE MID 30S VALLEY AND WEST. SAFE TO SAY TODAYS HIGHS
HAVE BEEN REACHED AND TEMPS WILL FALL FOR THE REST OF THE DAY AS
925MB TEMPS DROP 10 TO 20 C BY 00Z THURS. SOME -SN IS LIKELY ACROSS
THE SW PORTION OF THE CWFA AS A WEAK IMPULSE MOVES SE ALONG THE
BAROCLINIC ZONE AND UNDER THE 300MB RIGHT EXIT REGION. EXPECT AN
INCH OR TWO ALONG AND SOUTH OF A LINE FROM DVL TO W CASS TO ELBOW
LAKE.
SFC HIGH PRESSURE SLIDES ACROSS THE REGION TONIGHT AND TEMPS WILL
BE HIGHLY DEPENDENT ON CLOUD COVER WITH THE COLDEST VALUES
EXPECTED ACROSS THE NW MN... NEAR ZERO IN THE FAR WEST TO ALMOST
20 BELOW IN THE N RRV AND ROX TO BDE AREAS. A SLOW RECOVERY
EXPECTED THURSDAY AS WEAK MIXING AND THE COLD COLUMN LIMIT
WARMING.
RETURN FLOW AHEAD OF THE NEXT SW IN THE NW FLOW BEGINS THURSDAY PM
AND SHOULD LIMIT TEMP DROP OFF ACROSS E ND AS CLOUDS/-SN IN THE
WAA MOVES INTO THE FA. SFC LOW TRACK ALONG AND SOUTH OF THE
INTERNATIONAL BORDER WILL KEEP BEST CHC FOR -SN ALONG THE
INTERNATIONAL BORDER AREAS TO BEMIDJI FRIDAY WITH WEST WINDS
ALLOWING FOR SOME WARMING ACROSS SE ND FRIDAY AFTN. COLD FRONT
PUSHES THROUGH OVERNIGHT WITH FALLING TEMPS EXPECTED DURING THE
DAY SATURDAY.
LONG TERM (SAT-TUE)... A COLD PERIOD COMING UP AS ALL LONG RANGE
MODELS SHOW THE POLAR LOW OVER HUDSON BAY. SEVERAL SHORT WAVES
WILL CONTINUE TO MOVE SOUTHEAST...ONE WILL MOVE THRU SUNDAY
FOLLOWED BY HIGH PRESSURE AND LIKELY THE COLDEST OF THE AIRMASSES
THIS WINTER SEASON FOR SUN NIGHT INTO TUESDAY. EXPECT TEMPS TO
REMAIN BLO ZERO SUN-TUE. WITH HIGH OVERHEAD AND LIKELY A CLEAR
SKY SHOULD HAVE WIDESPREAD -20S SUN NIGHT AND AGAIN MON
NIGHT...COLDEST IN THE NORTH AND EASTERN PARTS OF THE FCST AREA.
AVIATION...
CIGS SHOULD IMPROVE AS IFR/MVFR CONDITIONS ERODE WITH DRIER
NORTHERLY WINDS AT ALL TAF SITES. ANY STRONG GUSTS THIS MORNING
WILL DIMINISH DURING THE LATER HALF OF THE DAY WITH SFC HIGH
BUILDING IN TO THE REGION. SNOW BAND MAY CLIP THE DVL AND FAR TAF
SITES THROUGH EARLY AFTN... MAY CAUSE VSBY/CIGS TO DROP FOR A BRIEF
PERIOD.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
939 AM EST WED JAN 16 2013
.SYNOPSIS...
A WEAK RIDGE OF HIGH PRESSURE WILL BUILD EAST INTO THE OHIO VALLEY
TODAY. FOR TONIGHT INTO THURSDAY...A WEAK COLD FRONT WILL PUSH
EAST ACROSS THE GREAT LAKES. HIGH PRESSURE WILL BUILD BACK INTO
THE REGION ON FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A WEAK RIDGE OF HIGH PRESSURE WILL BUILD EAST INTO THE OHIO VALLEY
TODAY. LOW LEVEL MOISTURE WILL SCOUR AND/OR SHIFT OFF TO THE EAST
AS DRIER AIR FILTERS INTO THE REGION FROM THE WEST. CLOUDS STILL
MAY BE SLOW TO CLEAR AS HIGH LEVEL MOISTURE LINGERS. WENT CLOSE
TO GUIDANCE FOR HIGHS THIS AFTERNOON WHICH SHOULD RANGE FROM THE
MID AND UPPER 30S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
A WEAK COLD FRONT WILL GLANCE THE NORTHEASTERN PARTS OF OUR AREA
TONIGHT INTO THURSDAY MORNING. SOME LIGHT PRECIPITATION WILL PASS
TO OUR NORTH AND IS NOT EXPECTED TO REACH OUR ZONES AT THIS TIME.
HIGH PRESSURE WILL THEN BEGIN TO BUILD ACROSS THE REGION LATER
ON THURSDAY. GRADUAL CLEARING IS EXPECTED TO OCCUR ON THURSDAY AS
WELL. CLEARING WILL EXTEND INTO THURSDAY NIGHT AS THE RIDGE
CONTINUES TO EXTEND ACROSS THE OHIO VALLEY. THIS WILL BRING SOME
FAVORABLE RADIATIONAL COOLING CONDITIONS THURSDAY NIGHT.
THEREFORE...WENT BELOW MODEL GUIDANCE FOR LOWS FOR THAT PARTICULAR
PERIOD.
THE RIDGE WILL THEN SLIDE SOUTH OF OUR AREA FRIDAY AND SETTLE
ACROSS THE SOUTHEASTERN ATLANTIC COAST BY SATURDAY. THIS WILL BRING
A TRANSITION TO RETURN FLOW WHICH IN TURN WILL BRING ABOUT A
GRADUAL WARMING TREND FROM FRIDAY THROUGH SATURDAY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
MUCH COOLER AIR IS IN STORE FOR THE REMAINDER OF THE LONG TERM
TIME FRAME. AN UPPER LEVEL DISTURBANCE WILL MOVE THROUGH THE FA
SATURDAY NIGHT BRINGING A CHANCE FOR SNOW SHOWERS TO NORTHERN
PORTIONS OF THE FA. COOLER AIR WILL BE USHERED INTO THE AREA
SATURDAY NIGHT WITH LOWS DROPPING INTO THE 20S BY SUNDAY MORNING.
NOT EXPECTING MUCH IN THE WAY OF AN INCREASE IN TEMPERATURES ON
SUNDAY AS COLDER AIR CONTINUES TO FILTER INTO THE AREA.
THE NEXT DISTURBANCE WILL WORK INTO THE AREA MONDAY INTO MONDAY
NIGHT ALLOWING FOR A BETTER CHANCE OF SOME SNOW SHOWERS AND A
REINFORCING SHOT OF COLD AIR. WITH COOLER AIR WORKING INTO THE AREA
AND WITH CLOUD COVER EXPECT HIGH TEMPERATURES ON MONDAY ONLY TO
REACH INTO THE UPPER TEENS TO MIDDLE 20S. THE TEMPERATURES WILL
DROP OFF INTO THE UPPER SINGLE DIGITS TO THE LOW TEENS MONDAY
NIGHT. CLOUD COVER ACROSS THE AREA WILL KEEP TEMPERATURES FROM
DROPPING EVEN FURTHER. WITH WINDS OFF OF THE LAKE SOME LAKE EFFECT
SNOW SHOWERS MAY LINGER THROUGH THE DAY ON TUESDAY BEFORE DRY
CONDITIONS RETURN TO THE REGION TUESDAY NIGHT. EXPECT THE COLDEST
NIGHT TO BE TUESDAY NIGHT WITH LESS CLOUD COVER ACROSS THE AREA.
WIDESPREAD SINGLE DIGIT TEMPERATURES WILL BE POSSIBLE TUESDAY NIGHT.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
PCPN HAS PUSHED WELL SOUTHEAST OF THE TAF SITES THIS MORNING. MAIN
CONCERN IS SOME LINGERING MVFR CIGS THAT EXTEND BACK INTO PARTS
OF EASTERN INDIANA. THE LATEST RAP IS ACTUALLY TRYING TO CLEAR
THESE LOWER CLOUDS OUT THROUGH LATE MORNING AS LOW LEVEL FLOW
BECOMES NORTHWESTERLY. WILL TREND THE FORECAST ACCORDINGLY AND
ALLOW FOR CLOUDS TO START TO SCATTER OUT THROUGH MID DAY. HIGH
PRESSURE AND A DRIER AIRMASS WILL THEN SETTLE INTO THE REGION
THROUGH THIS AFTERNOON. A WEAKENING BOUNDARY WILL PUSH DOWN FROM
THE NORTHWEST LATER TONIGHT. THIS COULD LEAD TO AN INCREASE IN
MAINLY VFR CIGS LATE IN THE PERIOD.
OUTLOOK...NO SIGNIFICANT WEATHER IS EXPECTED.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HICKMAN/LATTO
NEAR TERM...HICKMAN/LATTO
SHORT TERM...LATTO/HICKMAN
LONG TERM...NOVAK
AVIATION...JGL
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
632 AM EST WED JAN 16 2013
.SYNOPSIS...
LOW PRESSURE WILL EXIT THE REGION TODAY. HIGH PRESSURE WILL
GRADUALLY BUILD ACROSS THE AREA STARTING THURSDAY. THIS WILL
BRING A PERIOD OF QUIET WEATHER THROUGH THE START OF THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LOW PRESSURE LOCATED OVER THE CENTRAL APPALACHIANS WILL CONTINUE
ITS NORTHEASTWARD TRACK TOWARD THE NEW ENGLAND COAST TODAY. THE
BACK EDGE OF A WINTRY MIX OF PRECIPITATION WILL EXIT THE
SOUTHEASTERN PORTIONS OF THE FORECAST AREA BY MID MORNING. HAVE
CANCELLED THE WINTER WEATHER ADVISORY FOR ALL OTHER ZONES EXCEPT
THOSE WITH ONGOING PRECIPITATION. CLOUD COVER EXTENDING FROM THE
EAST COAST WESTWARD TO ILLINOIS WILL TAKE ITS TIME DEPARTING OUR
AREA TODAY. EVENTUALLY...SOME BREAKS TO OUR NORTHWEST WILL TRY TO
MAKE IT INTO THE NORTHERN PARTS OF THE FORECAST AREA THIS
AFTERNOON. HOWEVER...THIS WILL BE SHORT LIVED AS CLOUD COVER WILL
ONCE AGAIN INCREASE AS A COLD FRONT APPROACHES FROM THE NORTH THIS
EVENING.
HIGH TEMPERATURES WILL REMAIN IN CHECK TODAY WITH CLOUD COVER
PERSISTING FOR MUCH OF THE AREA. WENT CLOSE TO GUIDANCE FOR HIGHS.
HOWEVER...AS THE PAST FEW DAYS HAVE SHOWN...THESE NUMBERS MAY BE
TOO HIGH IF WE DO NOT SEE MUCH OF THE WAY OF ANY SUN TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
THE COLD FRONT WILL GLANCE THE NORTHEASTERN PARTS OF OUR AREA
WEDNESDAY LATE NIGHT. SOME LIGHT PRECIPITATION WILL PASS TO OUR
NORTH AND IS NOT EXPECTED TO REACH OUR ZONES AT THIS TIME.
HIGH PRESSURE WILL THEN BEGIN TO BUILD ACROSS THE REGION ON
THURSDAY. GRADUAL CLEARING IS EXPECTED TO OCCUR ON THURSDAY AS
WELL. CLEARING WILL EXTEND INTO THURSDAY NIGHT AS THE RIDGE
CONTINUES TO EXTEND ACROSS THE OHIO VALLEY. THIS WILL BRING SOME
FAVORABLE RADIATIONAL COOLING CONDITIONS THURSDAY NIGHT.
THEREFORE...WENT BELOW MODEL GUIDANCE FOR LOWS FOR THAT PARTICULAR
PERIOD.
THE RIDGE WILL THEN SLIDE SOUTH OF OUR AREA FRIDAY AND SETTLE
ACROSS THE SOUTHEASTERN ATLANTIC COAST BY SATURDAY. THIS WILL BRING
A TRANSITION TO RETURN FLOW WHICH IN TURN WILL BRING ABOUT A
GRADUAL WARMING TREND FROM FRIDAY THROUGH SATURDAY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
MUCH COOLER AIR IS IN STORE FOR THE REMAINDER OF THE LONG TERM
TIME FRAME. AN UPPER LEVEL DISTURBANCE WILL MOVE THROUGH THE FA
SATURDAY NIGHT BRINGING A CHANCE FOR SNOW SHOWERS TO NORTHERN
PORTIONS OF THE FA. COOLER AIR WILL BE USHERED INTO THE AREA
SATURDAY NIGHT WITH LOWS DROPPING INTO THE 20S BY SUNDAY MORNING.
NOT EXPECTING MUCH IN THE WAY OF AN INCREASE IN TEMPERATURES ON
SUNDAY AS COLDER AIR CONTINUES TO FILTER INTO THE AREA.
THE NEXT DISTURBANCE WILL WORK INTO THE AREA MONDAY INTO MONDAY
NIGHT ALLOWING FOR A BETTER CHANCE OF SOME SNOW SHOWERS AND A
REINFORCING SHOT OF COLD AIR. WITH COOLER AIR WORKING INTO THE AREA
AND WITH CLOUD COVER EXPECT HIGH TEMPERATURES ON MONDAY ONLY TO
REACH INTO THE UPPER TEENS TO MIDDLE 20S. THE TEMPERATURES WILL
DROP OFF INTO THE UPPER SINGLE DIGITS TO THE LOW TEENS MONDAY
NIGHT. CLOUD COVER ACROSS THE AREA WILL KEEP TEMPERATURES FROM
DROPPING EVEN FURTHER. WITH WINDS OFF OF THE LAKE SOME LAKE EFFECT
SNOW SHOWERS MAY LINGER THROUGH THE DAY ON TUESDAY BEFORE DRY
CONDITIONS RETURN TO THE REGION TUESDAY NIGHT. EXPECT THE COLDEST
NIGHT TO BE TUESDAY NIGHT WITH LESS CLOUD COVER ACROSS THE AREA.
WIDESPREAD SINGLE DIGIT TEMPERATURES WILL BE POSSIBLE TUESDAY NIGHT.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
PCPN HAS PUSHED WELL SOUTHEAST OF THE TAF SITES THIS MORNING. MAIN
CONCERN IS SOME LINGERING MVFR CIGS THAT EXTEND BACK INTO PARTS
OF EASTERN INDIANA. THE LATEST RAP IS ACTUALLY TRYING TO CLEAR
THESE LOWER CLOUDS OUT THROUGH LATE MORNING AS LOW LEVEL FLOW
BECOMES NORTHWESTERLY. WILL TREND THE FORECAST ACCORDINGLY AND
ALLOW FOR CLOUDS TO START TO SCATTER OUT THROUGH MID DAY. HIGH
PRESSURE AND A DRIER AIRMASS WILL THEN SETTLE INTO THE REGION
THROUGH THIS AFTERNOON. A WEAKENING BOUNDARY WILL PUSH DOWN FROM
THE NORTHWEST LATER TONIGHT. THIS COULD LEAD TO AN INCREASE IN
MAINLY VFR CIGS LATE IN THE PERIOD.
OUTLOOK...NO SIGNIFICANT WEATHER IS EXPECTED.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...LATTO
NEAR TERM...LATTO
SHORT TERM...LATTO
LONG TERM...NOVAK
AVIATION...JGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
729 PM EST THU JAN 17 2013
.SYNOPSIS...
AN ARCTIC FRONTAL BOUNDARY WILL SAG INTO NORTHERN PENNSYLVANIA
THIS EVENING. AT THE SAME TIME...A DEVELOPING STORM WILL PASS
JUST TO THE SOUTH OF THE STATE. AFTER A COLD DAY ON FRIDAY...
TEMPERATURES WILL MODERATE A BIT ON SATURDAY BEFORE A SHOT OF MUCH
COLDER AIR ARRIVES SUNDAY. TEMPERATURES WILL DIP TO NEAR OR BELOW
ZERO IN PARTS OF THE AREA NEXT WEEK AS THE COLDEST AIR OF THE
SEASON MOVES IN.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
5 PM UPDATE...
THICK...MULTI-LAYERED CLOUD SHIELD CONTINUES TO STREAM NE OVER
THE AREA FROM THE DEVELOPING WAVE OVER THE SERN US. NRN EDGE OF
THE PRECIP IS ACROSS SRN WVA AND NRN VA /JUST SOUTH OF THE D.C.
AREA/. HRRR AND 4KM NAM SHOWS THE NRN EDGE OF THE PRECIP REMAINING
STATIONARY THEN SAGGING SLOWLY SOUTH AND EAST THROUGH THIS
EVENING. THIS AGREES WITH THE LATEST TRENDS ON THE KLWX 88D.
MAIN CONCERN FOR THIS EVENING FOR ANY MEASURABLE PRECIP WILL BE
INVOF A SLOW MOVING EAST/WEST ARCTIC BOUNDARY DRAPED ACROSS
SOUTHERN NEW YORK. SOME VERY WEAK...AND FLEETING ISENTROPIC LIFT
NEAR THE 275K THETA SFC /AHEAD OF A WEAK WAVE OF LOW PRESSURE
ALONG THE BOUNDARY/ WILL SUPPORT AN AREA OF LIGHT SNOW POSSIBLY
DRIFTING SOUTH OF THE PENN/NY BORDER. A LIGHT COATING OF SNOW IS
POSSIBLE NEAR AND TO THE NORTH OF ROUTE 6. THIS FRONT WILL
FOLLOWED BY SOME LAKE EFFECT SNOW SHOWERS ACRS NWRN PENN BY
MIDNIGHT. THE SNOW SHOWERS SHOULD CONTINUE INTO FRIDAY MORNING.
STRATO CU CLOUD TEMPS BENEATH THE SUBSIDENCE INVERSION /THAT WILL
BRIEFLY POKE UP TO AROUND 7-8 KFT AGL THIS EVENING/ WILL BE
IN THE FAVORABLE DENDRITIC GROWTH ZONE...SO SOME NARROW SNOW BANDS
COULD DROP A QUICK INCH OR TWO NEAR AND TO THE WEST OF KBFD.
ELSEWHERE ACROSS THE CENTRAL MTNS AND SUSQ VALLEY REGION...NOTHING
MORE THAN SOME FLURRIES ARE POSSIBLE.
TEMPS THIS EVENING WILL VARY FROM THE MID AND UPPER 20S ALONG THE
PA/NY BORDER...TO THE LOWER AND MID 30S THROUGHOUT THE CENTRAL AND
SOUTHERN VALLEYS.
LOWS TONIGHT WILL BE VERY NEAR TO SLIGHTLY BELOW NORMAL.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
LATEST GUIDANCE STILL KEEPS THE SRN STREAM SYSTEM ROLLING TO THE
EAST-NORTHEAST...KEEPING THE THREAT OF PRECIP SOUTH OF THE MASON-
DIXON LINE. THE WAVE IS MADE TO DEEPEN OFF SHORE FRIDAY AS IT
SPEEDS AWAY...BEING REPLACED BY A STRONG HIGH FROM THE TN VALLEY.
CLEARING IS POSSIBLE ON FRIDAY AS THE ADVECTION CHANGES SIGN IN
THE AFTN...AND WE SEE THE ARCTIC AIR BEAT A QUICK RETREAT OFF TO
THE NORTHEAST AS THE FLOW GOES SW ON THE BACK SIDE OF THE HIGH.
DESPITE THE WARM ADVECTION THAT IS EXPECTED TO DEVELOP DURING THE
DAY...HIGHS IN THE 20S AND 30S WILL STILL AVERAGE WELL BELOW
NORMAL.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
SFC HIGH PRES WILL SLIDE ENEWD FROM THE TN VLY INTO THE SRN MID ATLC
FRIDAY EVENING BEFORE EXPANDING ACRS THE SE STATES INTO SATURDAY.
A STRONG AND RELATIVELY MILD SWLY LLVL FLOW /40-50KT LLJ/ IN-BTWN
THE AFOREMENTIONED SFC HIGH AND CLIPPER LOW CROSSING THE UPPER GRT
LKS WILL PRODUCE STG LOW-MID LVL WAA...PUSHING 850MB TEMPS ABV 0C
IN MOST AREAS ON SAT. THIS SHOULD RESULT IN A BRIEF WARM-UP ON
SATURDAY WITH HIGHS PROJECTED TO CLIMB SEVERAL DEGREES ABV NORMAL.
H5 SHORTWAVE TROUGH AND ASSOCD CLIPPER SFC LOW WILL TRACK EWD ACRS
SRN ONTARIO INTO THE ST. LAWRENCE RIVER VALLEY SAT NGT INTO EARLY
SUNDAY. MODELS REMAIN IN GOOD AGREEMENT IN PLOWING AN ARCTIC FRONT
SEWD ACRS THE CWA EARLY SUNDAY WITH TEMPS ALOFT PLUMMETING TO -10
TO -15C AT 850MB BY 00Z MONDAY. THE POTNL MAY EXIST FOR HIGH
IMPACT SUB-ADVY /HISA/ SNOW SQUALLS WITH THE ARCTIC FROPA...WHICH
COULD CAUSE RAPID WHITE-OUT CONDS. SOME LAKE EFFECT SNOW SHOWERS
ARE ALSO POSSIBLE OVER THE NW MTNS.
*THE NDFD WEB GRAPHICS SHOW "HEAVY SNOW" FOR SAT NGT/EARLY SUNDAY.
WE ARE NOT EXPECTING HEAVY SNOW IN A LITERAL SENSE...BUT HAVE
INSERTED +SW /HEAVY SQUALLS/ INTO THE GRIDS WHICH GETS TRANSLATED
INTO HEAVY SNOW ON THE NDFD WEB GRAPHICS.* HEAVY SNOW SQUALLS
PRODUCE INTENSE BURSTS OF SNOW WITH ACCUMS GENERALLY LESS THAN 1"
OVER A SHORT DURATION.
MEDIUM RANGE MODEL AND ENSEMBLE GUIDANCE REMAINS IN VERY GOOD
AGREEMENT IN DEPICTING A DEEP TROUGH OVER THE ERN U.S....WITH A
VERY COLD POLAR VORTEX /-40C AT 500MB/ SITUATED OVER HUDSON BAY.
THE STRONG COLD SIGNAL IN THE LARGE SCALE PATTERN WILL SUPPORT
HIGH CONFIDENCE IN BELOW NORMAL TEMPERATURES THROUGH THE PERIOD.
PRELIM DAY 4-7 MAX/MIN TEMPS WERE DERIVED USING AN EVEN BLEND OF
17/00Z HPC/NAEFS/GFS/ECMWF MOS DATA. INITIAL VERIFICATION OF THE
EXPERIMENTAL 00Z ECMWF MOS DATA HAS SHOWN INCREASED SKILL OVER THE
GFS-BASED GUIDANCE AT THIS RANGE...AND IS NOTABLY COLDER EARLY NEXT
WEEK WHEN TEMPS SHOULD REACH THEIR BOTTOM...WITH -20C AIR AT H85.
FINAL AFTN TEMPS WERE NUDGED TOWARD THE 12Z GMOS WHICH RESULTED
IN ONLY MINOR CHANGES TO PRELIM FCST.
THE WELL-ADVERTISED MODIFIED ARCTIC OUTBREAK WILL DELIVER THE
COLDEST AIR OF THE SEASON TO THE AREA...ARRIVING ON SCHEDULE AS WE
ENTER THE HEART OF CLIMATOLOGICAL WINTER. THE UPPER LEVEL RIDGE IN
THE WEST IS PROJECTED TO BREAK-DOWN BY THE END OF THE PERIOD...AND
SHOULD ALLOW FOR SOME MODERATION INTO THE SECOND HALF OF NEXT WEEK.
THE GFS REMAINS SLIGHTLY FASTER THAN THE NON-NCEP GUID IN LIFTING
THE BASE OF THE ERN TROUGH NWD AT DAY 7-8. PRECIPITATION DURING THE
PERIOD WILL BE LIMITED/CONFINED MAINLY TO THE WESTERN HIGH
TERRAIN...WITH WEAK CLIPPERS REINFORCING THE COLD NWLY FLOW.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
MVFR CIGS WILL CONTINUE OVER MAINLY THE NORTHWEST MOUNTAINS
TONIGHT. KJST AND VCNTY WILL LIKELY SEE VFR FOR THE FIRST HALF OF
TONIGHT...FOLLOWED BY MVFR CIGS LATE.
LAKE MOISTURE CLIMBING THE HIGH TERRAIN OF THE NORTHWEST WILL
KEEP THE CHANCE OF SNOW SHOWERS AND LOCALLY REDUCED CONDITIONS IN
THE PICTURE INTO AT LEAST MID DAY FRIDAY...WITH IMPROVEMENT
EXPECTED BY FRIDAY AFTERNOON AND EVENING AS WINDS TURN MORE
SOUTHWESTERLY ON THE BACK SIDE OF A RETREATING HIGH.
THE TIGHT GRADIENT OVER THE REGION SHOULD ALLOW FOR GUSTY WINDS
LATE TOMORROW MORNING...THROUGH MOST OF THE AFTERNOON.
OUTLOOK...
FRI...AM -SHSN/MVFR CIGS POSS W MTNS.
SAT...NO SIG WX EXPECTED.
SUN-TUE...SHSN/MVFR POSS W MTNS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE/LAMBERT
SHORT TERM...LA CORTE
LONG TERM...STEINBUGL
AVIATION...LA CORTE/CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
452 AM EST WED JAN 16 2013
.SYNOPSIS...
WINTRY PRECIPITATION WILL TAPER OFF THIS MORNING. A SURGE OF
COLDER AIR WILL MOVE ACROSS THE LOWER LAKES THURSDAY AND BRING
SCATTERED SNOW SHOWERS TO THE HIGHER TERRAIN. A STORM SHOULD MOVE
THROUGH THE MID-ATLANTIC STATES THURSDAY...BUT IT SHOULD STAY TO
THE SOUTH OF THE AREA. TEMPERATURES WILL MODERATE A BIT ON
SATURDAY BEFORE MUCH COLDER AIR ARRIVES SUNDAY AND MONDAY.
TEMPERATURES MAY DIP INTO THE SINGLE DIGITS IN PARTS OF THE AREA
NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MOST RECENT RAP/RUC AND HRRR RUNS PORTRAY THE CURRENT RADAR
TRENDS VERY NICELY...AND HIGH CONFIDENCE IN THESE SOLUTIONS IS THE
RESULT. THE BREAK/VERY LIGHT PRECIP SHOULD BE THE ESSENTIAL END
TO THE BEST ACCUMULATIONS. ONE OR TWO MORE WEAK SURGES OF HIGHER
PRECIP RATES COULD AFFECT THE CENTRAL AND NORTHERN AREAS THIS
MORNING. THE FIRST OF WHICH APPEARS TO BE MOVING THRU THE LAURELS
RIGHT NOW. THINGS WILL DEFINATELY BE TAPERING OFF THROUGH THE
EARLY MORNING. WHILE A DUSTING/THIN ACCUMULATION OF SNOW OR SLEET
IS POSSIBLE ACROSS THE NORTH AFTER 10 OR 11 AM...IT APPEARS IT
PROBABLY WON/T WARRANT EXTENDING THE ADVY AND WILL LET IT RIDE AS
IS FOR NOW. WILL ALSO KEEP THE REST OF THE ADVY IN PLACE WITH
MORNING TRAVEL PROBLEMS LIKELY DUE TO SECONDARY AND TERTIARY ROADS
STILL COVERED WITH SNOW/ICE FOR A FEW HOURS AFTER SUNRISE. TEMPS
ARE AT OR BELOW FREEZING FOR ALL BUT KCXY AT THIS HOUR. THIS KEEPS
THE THREAT OF FZRA GOING FOR THE NEXT FEW HRS IN THE LOWER SUSQ.
SKY WILL REMAIN CLOUDY FOR A GOOD PORTION OF THE DAY...BUT SOME
CLEARING IS POSSIBLE THIS AFTN - ESP IN THE N.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
BASE OF THE BROAD UPPER TROUGH WILL BE OVERHEAD ON
THURSDAY...KEEPING A SIGNIFICANT SHORT WAVE TROUGH ROLLING EAST
THROUGH THE SMOKIES. THIS WAVE LOOKS TO DEVELOP FURTHER AND BECOME
A FAIRLY DECENT PRECIP/SNOW THREAT -- BUT SHOULD ALSO STAY TO THE
SOUTH OF THE AREA. THE FAR NRN EDGE OF THE PRECIP SHIELD MAY TOUCH
THE FAR SE ON THURS AFTN/EVENING...BUT ONLY A CHC POP IS WARRANTED
AT THIS POINT. THE BIGGER STORY WILL BE THE ARCTIC FRONT MOVING
DOWN ACROSS THE GREAT LAKES ON THURSDAY. WHILE THE 8H TEMPS DIP
GRADUALLY TODAY AND TONIGHT...THE COLD ADVECTION REALLY RAMPS UP
ON THURSDAY. THIS SHOULD CREATE SNOW SHOWERS AND PERHAPS A FEW
SQUALLS IN THE NWRN MTS. WILL HOLD ONTO CURR/SCT POPS FOR A BIT
DUE TO TIMING DIFFERENCES.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
SCATTERED -SHSN ARE POSSIBLE ACROSS NORTHERN AND WESTERN PA IN
THE CHILLY NORTHWESTERLY FLOW BEHIND THE FRONT. BY FRIDAY...850MB
TEMPS ARE ALREADY ON THE RISE AS HIGH PRESSURE PUSHES OFF THE EAST
COAST AND SOUTHERLY FLOW DEVELOPS.
SATURDAY WILL BE A MILD DAY...BEFORE A MORE POTENT COLD FRONT
CROSSES THE AREA SAT NIGHT/SUNDAY. ANOTHER SHOT OF COLDER AIR
WILL BE ACCOMPANIED BY A RENEWED CHC OF SHSN ACROSS NORTHERN AND
WESTERN PA ON SUNDAY.
THE EARLY PART OF NEXT WEEK LOOKS WINTER-LIKE...WITH BELOW-NORMAL
TEMPERATURES. THE 12Z OPERATIONAL GFS AND ECMWF BOTH SWING A PIECE
OF ENERGY AROUND THE BASE OF THE EASTERN U.S. TROUGH IN THE MON/TUES
TIMEFRAME...BUT CURRENTLY HAVE COASTAL LOW PRES DEVELOPMENT
OCCURRING TOO FAR NORTH/EAST OF THE AREA TO HAVE MUCH OF AN IMPACT.
&&
.AVIATION /10Z WEDNESDAY THROUGH SUNDAY/...
A LARGE AREA OF HEAVY SNOW IS OVER MUCH OF SOUTH CENTRAL
PA...ALONG WITH A MIXTURE OF RAIN...SLEET...AND FREEZING
RAIN ACROSS THE SE.
ADVERSE CONDITIONS WILL COTINUE OVERNIGHT INTO WED MORNING...
BEFORE IMPROVING.
EARLIER DISCUSSION BELOW.
SCATTERED PRECIPITATION CONTINUES TO SPREAD ACROSS THE REGION.
SNOW SHOULD DOMINATE ACROSS CENTRAL PA NORTH...WITH A WINTRY MIX
ACROSS THE SOUTHEAST...AND FREEZING RAIN AND SNOW MIX ACROSS THE
LAURELS...IN IFR AND LOWER ACROSS ALL TAF SITES BY 06Z...WITH BFD
BY 09Z AT THE LATEST. PERIODS OF -FZRA FROM SHIFTING WARM AIR
ALOFT FROM 07Z TO 12Z ARE POSSIBLE IN THE SE. HIGHEST QPF WILL OCCUR
ACROSS SOUTHERN TIER...ALONG WITH HIGHEST THREAT OF ICING
CONDITIONS IN THE KJST- KAOO AREA. ALL AREAS SHOULD CLEAR BETWEEN
18 TO 21Z TOMORROW AFTERNOON.
OUTLOOK...
WED...AM WINTRY MIX/LOW CIGS.
THU...SHSN/OCNL MVFR POSS NW MTNS. WINDY.
FRI-SAT...NO SIG WX EXPECTED.
SUN...SHSN/OCNL MVFR POSS NW MTNS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR
PAZ012-017>019-024>028-033>037-041-042-045-046-049>053-056>059-
063>066.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DANGELO
LONG TERM...EVANEGO
AVIATION...CERU/MARTIN/RXR
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
845 PM CST THU JAN 17 2013
.DISCUSSION.../ISSUED AT 845 PM CST/
THE WARM FRONT IS PRESENTLY SITUATED THROUGH OUR SOUTH CENTRAL SOUTH
DAKOTA ZONES LATE THIS EVENING. AS EXPECTED MID CLOUDS ALSO
STREAMING OVERHEAD...WITH BROKEN STRATUS COVERING A GOOD BIT OF OUR
NORTH AND EAST EARLIER IN THE EVENING NOW MOSTLY DISSIPATING EXCEPT
FOR SOME AREAS OF NORTHWESTERN IOWA. ALL MODELS ARE OVERDOING THE
EXTENT OF STRATUS THIS EVENING...BUT ALL POINT TOWARD ANY EXISTING
LOW CLOUDS PULLING OFF TO THE NORTHEAST OVERNIGHT AS THE LOW LEVEL
FLOW TURNS SOUTH/SOUTHWESTERLY. OBS INDICATING SOME FOG DEVELOPING
JUST TO OUR SOUTH...THROUGH EASTERN NEBRASKA...WITH A FEW LOWERING
VISIBILITIES OVER NORTHWESTERN IOWA ALSO...SO PATCHY FOG REMAINS
APPROPRIATE IN THE FORECAST FOR PARTS OF THE AREA TONIGHT.
TEMPERATURES ARE ON TRACK FOR LOWS MAINLY IN THE 20S...POSSIBLY
RISING A BIT LATER IN THE NIGHT AS WINDS PICK UP AND CLOUDS CONTINUE
TO STREAM ACROSS THE REGION. GOING FORECAST COVERS THE ABOVE
MENTIONED ELEMENTS PRETTY WELL...WITH ONLY MINOR UPDATES FOR REAL
TIME TRENDS.
&&
.AVIATION.../FOR THE 00Z TAF ISSUANCE/
GENERALLY VFR CONDITIONS EXPECTED ACROSS THE REGION THROUGH 00Z
SATURDAY. PATCHY MVFR CEILINGS WILL STILL BE POSSIBLE THROUGH 12Z.
PATCHY FOG MAY ALSO DEVELOP TONIGHT INTO EARLY FRIDAY MORNING OVER
PORTIONS OF NORTHWEST IOWA AND FAR SOUTHEAST SOUTH DAKOTA.
&&
.PREV DISCUSSION.../ISSUED AT 311 PM CST/
WARM FRONT LIFTS NORTH TONIGHT GIVING WAY TO A MILD AND MOSTLY SUNNY
FRIDAY ACROSS THE AREA. FORECAST TONIGHT A BIT TRICKY WITH POTENTIAL
STRATUS ISSUES. MID LEVEL CLOUDS WILL CONTINUE TO STREAM ACROSS OUR
NORTH THROUGH THE NIGHT ASSOCIATED WITH MID LEVEL FRONTAL BOUNDARY.
HOWEVER THINK THE CWA WILL REMAIN DRY...OTHER THAN MAYBE AN ISOLATED
FLURRY ACROSS SOUTHWEST MINNESOTA. AREA OF STRATUS FROM SOUTH OF
SIOUX FALLS INTO EASTERN NEBRASKA CONTINUES TO DISSIPATE UNDER
DAYTIME HEATING. HOWEVER...CURRENT THINKING...BACKED BY THE RAP AND
NAM...IS THAT THIS AREA WILL REFORM AND EXPAND THIS EVENING INTO
TONIGHT. WITH SOUTHERLY BOUNDARY LAYER FLOW THIS WILL THEN EXPAND
AND COULD COVER MUCH OF THE CWA FOR A PERIOD TONIGHT. DRIER BOUNDARY
LAYER MOVING IN FROM THE SOUTHWEST WILL ALLOW THE STRATUS TO CLEAR
FROM SOUTHWEST TO NORTHEAST THROUGH THE NIGHT. COULD BE AREAS OF FOG
AS WELL. BEST CHANCE OF STAYING CLEAR THROUGH THE NIGHT WILL BE WEST
OF SIOUX CITY TO YANKTON UP TOWARDS GREGORY. LOW LEVEL JET INCREASES
TONIGHT...WHICH SHOULD KEEP A SOUTHERLY BREEZE GOING. THE BREEZE
COMBINED WITH POTENTIAL CLOUDS SHOULD KEEP LOWS ON THE WARM SIDE OF
GUIDANCE. GENERALLY AROUND 20 SOUTHWEST MINNESOTA TO LOW AND MID 20S
ELSEWHERE. LOWS WILL PROBABLY BE IN THE EVENING...WITH STEADY OR
RISING TEMPERATURES OVERNIGHT.
ANY STRATUS SHOULD EXIT THE CWA BY AROUND 12Z. COULD BE SOME CIRRUS
OVERHEAD DURING THE DAY...BUT OVERALL EXPECTING A MOSTLY SUNNY DAY.
KEPT HIGHS CLOSE TO THE ECMWF AND ECMWF MOS...AS THEY PERFORMED BEST
ON WEDNESDAY. LOOKING AT LOW AND MID 40S NORTH TO THE LOW AND MID
50S CLOSER TO THE MISSOURI RIVER. WITH 925MB TEMPERATURES
APPROACHING 10C IN OUR SOUTHWEST...WOULD NOT BE SURPRISED IF
SOMEPLACE IN NORTH CENTRAL NEBRASKA...OR ADJACENT AREAS OF GREGORY
AND CHARLES MIX COUNTIES COME CLOSE TO 60. /CHENARD
MAJOR PATTERN CHANGE EXPECTED TO BEGIN ON SATURDAY AS AN ARCTIC
BLAST DROPS SOUTHWARD INTO THE NORTHERN PLAINS. COLD FRONT SLATED TO
PUSH THROUGH THE FORECAST AREA DURING THE DAY...AND THE BIG QUESTION
IS HOW QUICKLY IT WILL ARRIVE. LARGE TEMPERATURE DISCREPANCIES
BETWEEN MODELS FOR SATURDAY HIGHS WITH A STAGGERING NEARLY 30 DEGREE
DIFFERENCE BETWEEN THE WARMEST AND COLDEST MODELS IN SIOUX FALLS.
THE GFS AND NAM ARE THE FASTEST WITH PULLING THE COLDER AIR INTO THE
FORECAST AREA WHILE THE ECMWF AND GEM PAINT A MUCH SLOWER
PROGRESSION AND DEPICT A MILD DAY ACROSS THE CWA. HAVE OPTED FOR A
MIDDLE GROUND SOLUTION WITH MIXING KEEPING TEMPERATURES ON THE
MILDER SIDE. EXPECT THE MISSOURI VALLEY TO REACH NEAR 40 RANGING TO
AROUND 30 AT OUR NORTHERN BORDER.
FRONTAL PASSAGE IS EXPECTED TO BE DRY...BUT STRONG NORTHWEST WINDS
IN ITS WAKE WILL PRODUCE SOME BRUTAL WIND CHILLS. WITH 925MB WINDS
UP AROUND 50 KT AND STRONG COLD AIR ADVECTION...WOULD NOT BE
SURPRISED TO SEE ADVISORY LEVEL WINDS. COLD AIR WILL QUICKLY DROP
SOUTH LATE EVENING INTO THE OVERNIGHT AND LOWS SATURDAY NIGHT WILL
BE IN THE SINGLE DIGITS ABOVE AND BELOW ZERO. WINDS WILL DECREASE ON
SUNDAY AS SURFACE HIGH PRESSURE QUICKLY SHUNTS SOUTHEAST OF THE
REGION...BUT DO NOT EXPECT MUCH RECOVERY OF TEMPERATURES. HIGHS WILL
ONLY BE IN THE SINGLE DIGITS AND TEENS FOR THE MAJORITY OF THE CWA.
A QUICK SHOT OF LIGHT SNOW WILL MOVE SOUTHEAST DURING THE DAY AHEAD
OF A REINFORCING SHOT OF COLD AIR. SNOW WOULD LIKELY BE BRIEF WITH
NOT MUCH MOISTURE TO WORK WITH...HOWEVER THE COLD TEMPERATURES
SHOULD PRODUCE UP TO AN INCH OF FLUFFY SNOW. NORTHERLY WINDS WILL
PICK UP ONCE AGAIN BEHIND THE FRONT AND WOULD DRIFT WHATEVER SNOW
FALLS ON SUNDAY. SUNDAY NIGHT WILL SEE SOME OF THE COLDEST
TEMPERATURES OF THE SEASON SO FAR WITH THE NORTHERN HALF DROPPING
INTO THE TEENS BELOW ZERO. FRIGID TEMPERATURES WILL CONTINUE INTO
MONDAY WITH HIGHS NEAR ZERO IN OUR NORTHEAST.
MODELS KEEP THE LARGE UPPER RIDGE OVER THE INTERMOUNTAIN WEST IN
PLACE INTO TUESDAY...WHICH LEAVES THE FORECAST AREA UNDER COOL
NORTHWEST FLOW. MODELS BRING A WEAK WAVE THROUGH THE FLOW AROUND THE
MONDAY NIGHT TO TUESDAY TIME FRAME...HOWEVER NOT A LOT OF CONFIDENCE
THAT THE CWA WILL SEE MUCH IMPACT. WILL LEAVE THE SLIGHT CHANCES
THAT THE LATEST ALLBLEND PRODUCED FOR NOW. WARMER WEATHER MAY RETURN
ON WEDNESDAY AND THURSDAY WITH THE RIDGE ADVANCING EASTWARD.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
620 PM CST THU JAN 17 2013
.DISCUSSION.../ISSUED AT 311 PM CST/
WARM FRONT LIFTS NORTH TONIGHT GIVING WAY TO A MILD AND MOSTLY SUNNY
FRIDAY ACROSS THE AREA. FORECAST TONIGHT A BIT TRICKY WITH POTENTIAL
STRATUS ISSUES. MID LEVEL CLOUDS WILL CONTINUE TO STREAM ACROSS OUR
NORTH THROUGH THE NIGHT ASSOCIATED WITH MID LEVEL FRONTAL BOUNDARY.
HOWEVER THINK THE CWA WILL REMAIN DRY...OTHER THAN MAYBE AN ISOLATED
FLURRY ACROSS SOUTHWEST MINNESOTA. AREA OF STRATUS FROM SOUTH OF
SIOUX FALLS INTO EASTERN NEBRASKA CONTINUES TO DISSIPATE UNDER
DAYTIME HEATING. HOWEVER...CURRENT THINKING...BACKED BY THE RAP AND
NAM...IS THAT THIS AREA WILL REFORM AND EXPAND THIS EVENING INTO
TONIGHT. WITH SOUTHERLY BOUNDARY LAYER FLOW THIS WILL THEN EXPAND
AND COULD COVER MUCH OF THE CWA FOR A PERIOD TONIGHT. DRIER BOUNDARY
LAYER MOVING IN FROM THE SOUTHWEST WILL ALLOW THE STRATUS TO CLEAR
FROM SOUTHWEST TO NORTHEAST THROUGH THE NIGHT. COULD BE AREAS OF FOG
AS WELL. BEST CHANCE OF STAYING CLEAR THROUGH THE NIGHT WILL BE WEST
OF SIOUX CITY TO YANKTON UP TOWARDS GREGORY. LOW LEVEL JET INCREASES
TONIGHT...WHICH SHOULD KEEP A SOUTHERLY BREEZE GOING. THE BREEZE
COMBINED WITH POTENTIAL CLOUDS SHOULD KEEP LOWS ON THE WARM SIDE OF
GUIDANCE. GENERALLY AROUND 20 SOUTHWEST MINNESOTA TO LOW AND MID 20S
ELSEWHERE. LOWS WILL PROBABLY BE IN THE EVENING...WITH STEADY OR
RISING TEMPERATURES OVERNIGHT.
ANY STRATUS SHOULD EXIT THE CWA BY AROUND 12Z. COULD BE SOME CIRRUS
OVERHEAD DURING THE DAY...BUT OVERALL EXPECTING A MOSTLY SUNNY DAY.
KEPT HIGHS CLOSE TO THE ECMWF AND ECMWF MOS...AS THEY PERFORMED BEST
ON WEDNESDAY. LOOKING AT LOW AND MID 40S NORTH TO THE LOW AND MID
50S CLOSER TO THE MISSOURI RIVER. WITH 925MB TEMPERATURES
APPROACHING 10C IN OUR SOUTHWEST...WOULD NOT BE SURPRISED IF
SOMEPLACE IN NORTH CENTRAL NEBRASKA...OR ADJACENT AREAS OF GREGORY
AND CHARLES MIX COUNTIES COME CLOSE TO 60. /CHENARD
MAJOR PATTERN CHANGE EXPECTED TO BEGIN ON SATURDAY AS AN ARCTIC
BLAST DROPS SOUTHWARD INTO THE NORTHERN PLAINS. COLD FRONT SLATED TO
PUSH THROUGH THE FORECAST AREA DURING THE DAY...AND THE BIG QUESTION
IS HOW QUICKLY IT WILL ARRIVE. LARGE TEMPERATURE DISCREPANCIES
BETWEEN MODELS FOR SATURDAY HIGHS WITH A STAGGERING NEARLY 30 DEGREE
DIFFERENCE BETWEEN THE WARMEST AND COLDEST MODELS IN SIOUX FALLS.
THE GFS AND NAM ARE THE FASTEST WITH PULLING THE COLDER AIR INTO THE
FORECAST AREA WHILE THE ECMWF AND GEM PAINT A MUCH SLOWER
PROGRESSION AND DEPICT A MILD DAY ACROSS THE CWA. HAVE OPTED FOR A
MIDDLE GROUND SOLUTION WITH MIXING KEEPING TEMPERATURES ON THE
MILDER SIDE. EXPECT THE MISSOURI VALLEY TO REACH NEAR 40 RANGING TO
AROUND 30 AT OUR NORTHERN BORDER.
FRONTAL PASSAGE IS EXPECTED TO BE DRY...BUT STRONG NORTHWEST WINDS
IN ITS WAKE WILL PRODUCE SOME BRUTAL WIND CHILLS. WITH 925MB WINDS
UP AROUND 50 KT AND STRONG COLD AIR ADVECTION...WOULD NOT BE
SURPRISED TO SEE ADVISORY LEVEL WINDS. COLD AIR WILL QUICKLY DROP
SOUTH LATE EVENING INTO THE OVERNIGHT AND LOWS SATURDAY NIGHT WILL
BE IN THE SINGLE DIGITS ABOVE AND BELOW ZERO. WINDS WILL DECREASE ON
SUNDAY AS SURFACE HIGH PRESSURE QUICKLY SHUNTS SOUTHEAST OF THE
REGION...BUT DO NOT EXPECT MUCH RECOVERY OF TEMPERATURES. HIGHS WILL
ONLY BE IN THE SINGLE DIGITS AND TEENS FOR THE MAJORITY OF THE CWA.
A QUICK SHOT OF LIGHT SNOW WILL MOVE SOUTHEAST DURING THE DAY AHEAD
OF A REINFORCING SHOT OF COLD AIR. SNOW WOULD LIKELY BE BRIEF WITH
NOT MUCH MOISTURE TO WORK WITH...HOWEVER THE COLD TEMPERATURES
SHOULD PRODUCE UP TO AN INCH OF FLUFFY SNOW. NORTHERLY WINDS WILL
PICK UP ONCE AGAIN BEHIND THE FRONT AND WOULD DRIFT WHATEVER SNOW
FALLS ON SUNDAY. SUNDAY NIGHT WILL SEE SOME OF THE COLDEST
TEMPERATURES OF THE SEASON SO FAR WITH THE NORTHERN HALF DROPPING
INTO THE TEENS BELOW ZERO. FRIGID TEMPERATURES WILL CONTINUE INTO
MONDAY WITH HIGHS NEAR ZERO IN OUR NORTHEAST.
MODELS KEEP THE LARGE UPPER RIDGE OVER THE INTERMOUNTAIN WEST IN
PLACE INTO TUESDAY...WHICH LEAVES THE FORECAST AREA UNDER COOL
NORTHWEST FLOW. MODELS BRING A WEAK WAVE THROUGH THE FLOW AROUND THE
MONDAY NIGHT TO TUESDAY TIME FRAME...HOWEVER NOT A LOT OF CONFIDENCE
THAT THE CWA WILL SEE MUCH IMPACT. WILL LEAVE THE SLIGHT CHANCES
THAT THE LATEST ALLBLEND PRODUCED FOR NOW. WARMER WEATHER MAY RETURN
ON WEDNESDAY AND THURSDAY WITH THE RIDGE ADVANCING EASTWARD.
&&
.AVIATION.../FOR THE 00Z TAF ISSUANCE/
GENERALLY VFR CONDITIONS EXPECTED ACROSS THE REGION THROUGH 00Z
SATURDAY. PATCHY MVFR CEILINGS WILL STILL BE POSSIBLE THROUGH 12Z.
PATCHY FOG MAY ALSO DEVELOP TONIGHT INTO EARLY FRIDAY MORNING OVER
PORTIONS OF NORTHWEST IOWA AND FAR SOUTHEAST SOUTH DAKOTA.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1146 AM CST WED JAN 16 2013
.DISCUSSION.../ISSUED AT 1045 AM CST/
A MILD AFTERNOON IS IN STORE ACROSS THE AREA...ESPECIALLY AS YOU
HEAD SOUTH TOWARDS THE MISSOURI RIVER. WENT AHEAD AND BUMPED UP
HIGHS A COUPLE TO SEVERAL DEGREES ACROSS THE AREA...WITH MID AND
EVEN A FEW UPPER 40S POSSIBLE FROM SIOUX CITY WEST TO GREGORY.
CLOUDS INCREASING ACROSS OUR NORTH...WITH PARTLY TO MOSTLY SUNNY
SKIES CONTINUING IN THE SOUTH. BACKDOOR COLD FRONT CURRENTLY
DROPPING SOUTH OUT OF WESTERN MINNESOTA AND NORTHEAST SOUTH DAKOTA.
WILL LIKELY SEE TEMPERATURES DROP QUICKLY INTO THE 20S AND TEENS
BEHIND THIS FRONT FROM NORTH TO SOUTH. LATEST RAP WOULD SUGGEST
FRONT PASSES THROUGH THE HIGHWAY 14 CORRIDOR NEAR 22Z...INTERSTATE
90 AROUND 0Z...AND OUR SOUTHERN COUNTIES CLOSER TO 3Z. COLDEST AIR
WILL ONLY CLIP OUR AREA...WITH THE BRUNT OF IT STAYING TO OUR EAST.
WATCHING SOME LIGHT SNOW BEHIND SURFACE FRONT ASSOCIATED WITH MID
LEVEL FRONTOGENESIS. BASED ON RADAR AND MODEL FORECASTS THINK MOST
OF THIS WILL STAY TO OUR NORTHEAST...ALTHOUGH COULD CLIP AREAS FROM
BROOKINGS TO MARSHALL WITH SOME LIGHT SNOW OF A COUPLE TENTHS.
ELSEWHERE....ALONG AND NORTH OF INTERSTATE 90 MAINLY JUST THINKING
SOME FLURRIES AT MOST. /CHENARD
.PREVIOUS DISCUSSION.../ISSUED AT 340 AM CST/
WEAK UPPER LEVEL SUPPORT WILL SPREAD ACROSS THE AREA
TODAY...CREATING CLOUD COVER BUT LITTLE INT HE WAY OF SNOWFALL. JUST
ENOUGH LOWER TO MID LEVEL MOISTURE WILL EXIST HOWEVER THAT FLURRIES
AND SOME LIGHT SNOW WILL BE POSSIBLE IN THE NORTHEAST HALF OF THE
CWA. PARTS OF SOUTHWEST MINNESOTA COULD RECEIVE A COUPLE OF TENTHS
OF AN INCH. OTHERWISE...TEMPERATURES HAVE WARMED QUITE A BIT
OVERNIGHT WITH A NICE MIXING WESTERLY WIND AHEAD OF THE COLDER DRIER
AIR EXPECTED TO ADVECT INTO THE AREA FROM THE NORTH. THIS WILL ALLOW
FOR A MILD DAY ACROSS THE AREA EVEN WITH CLOUD COVER...WITH HIGHS
RANGING FROM THE MID 30S IN SOUTHWEST MINNESOTA TO 40 TO 45 ALONG
THE MISSOURI RIVER.
A WEAK RIDGE OF COLD HIGH PRESSURE WILL SETTLE SOUTH TONIGHT WHICH
WILL ALLOW FOR SOME COLD OVERNIGHT LOW TEMPERATURES. WINDS WILL NOT
BE EXCESSIVE OVERNIGHT...BUT COULD DROP WIND CHILL VALUES TO 5 TO 10
BELOW ZERO OVER PARTS OF SOUTHWEST MINNESOTA. SNOWFALL IS NOT
EXPECTED AS SUBSIDENCE FILLS IN BEHIND TODAYS UPPER LEVEL WAVE. LOWS
OVERNIGHT WILL RANGE FROM AROUND 5 ABOVE IN SOUTHWEST MINNESOTA TO
NEAR 20 ALONG THE MISSOURI RIVER.
MIXING WILL BE A BIT LIMITED ON THURSDAY AS A RIDGE OF HIGH PRESSURE
REMAINS IN PLACE OVER THE EASTERN PART OF THE CWA. THIS WILL KEEP
TEMPERATURES A LITTLE COLDER...BUT STILL CLOSE TO NORMAL OVER
SOUTHWEST MINNESOTA...MAINLY IN THE MID 20S. FARTHER SOUTH AND WEST
TEMPERATURES WILL REBOUND A BIT AND CLIMB TO 35 TO 40 DEGREES.
THURSDAY NIGHT INTO FRIDAY WILL SEE A MILD AIR MASS DEVELOP WITH
SOUTHERLY WIND FRIDAY NIGHT...BECOMING WESTERLY ON FRIDAY. THIS IS
OF COURSE A FAVORABLE WIND DIRECTION SO EXPECT MORNING LOWS IN THE
TEENS AND FRIDAY HIGHS FROM ABOUT 35 TO 45 DEGREES.
IN THE LATTER PERIODS (SAT/TUE)...SATURDAY LIKELY TO BE THE LAST
MILD DAY FOR AWHILE...AND EVEN THAT IS A LITTLE QUESTIONABLE AS ALL
OF THE MODELS HAVE A COLD FRONT SURGING THROUGH BETWEEN 18Z AND 0Z
SO ANY MINOR INCREASE IN SPEED AND SATURDAY WILL BE MUCH COLDER. A
SLIGHT MODERATION IN TEMPERATURES ON SUNDAY AS A WAVE MOVES NORTH OF
THE AREA WHICH WILL BRIEFLY LIGHTEN WINDS OR TURN THEM A BIT
SOUTHERLY THEN DRAG DOWN THE COLDEST AIR OF THE SEASON SUNDAY NIGHT.
SOME DIFFERENCES IN SPEED BUT NOT MUCH DIFFERENCE IN HOW COLD BEHIND
THE FRONT SO SOME CONFIDENCE IN OVERALL TEMPERATURE FORECAST SUNDAY
THROUGH TUESDAY...WHICH WILL BE QUITE A BIT BELOW NORMAL. IF
EVERYTHING PANS OUT MORE THAN LIKELY WILL SEE A PERIOD OF LIGHT SNOW
ON SUNDAY THEN EITHER A WIND CHILL ADVISORY OR WIND CHILL WARNING
SUNDAY NIGHT THROUGH MONDAY EVENING. HIGH PRESSURE IS EXPECTED TO
BUILD SOUTH ON MONDAY NIGHT SO WINDS WILL GO LIGHT AND IF THERE IS
ANY FRESH SNOW COVER TUESDAY MORNING LOWS WILL BE QUITE COLD. /08
&&
.AVIATION.../FOR THE 18Z TAF ISSUANCE/
CURRENTLY SEEING AN AREA OF MVFR CIGS ACROSS SOUTHWEST
MINNESOTA...WITH VFR ELSEWHERE. THIS AREA IS PUSHING OFF TO THE
SOUTHEAST WITH IMPROVING CONDITIONS OVER THE NEXT FEW HOURS.
HOWEVER...A BACKDOOR COLD FRONT IS PUSHING SOUTH OUT OF NORTH DAKOTA
AND MINNESOTA. MAIN ADJUSTMENTS TO PREVIOUS FORECAST WAS TO SPEED UP
TIMING OF THUS FRONT AND ASSOCIATED MVFR STRATUS BY ABOUT AN
HOUR...AND KEEP MVFR CIGS INTO TOMORROW MORNING. TOUGH CALL ON THE
LATTER THOUGH. INITIAL SURGE OF MVFR AND POSSIBLY ISOLATED IFR CIGS
BEHIND THE FRONT WILL PUSH SOUTH TONIGHT. SOME LOW LEVEL DRYING
LIKELY BEHIND THIS...HOWEVER AS BOUNDARY LAYER FLOW BECOMES WEAK
WESTERLY TEND TO THINK MORE STRATUS MOVES IN OR LINGERS. THINK THERE
MAY BE SOME VFR PERIODS...BUT THE PREDOMINATE CIG MAY VERY WELL BE
MVFR THROUGH TOMORROW MORNING. AGAIN THIS IS LOW CONFIDENCE...WITH
ANYWHERE FROM IFR TO VFR POSSIBLE LATER TONIGHT INTO TOMORROW
MORNING. /CHENARD
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1046 AM CST WED JAN 16 2013
.DISCUSSION.../ISSUED AT 1045 AM CST/
A MILD AFTERNOON IS IN STORE ACROSS THE AREA...ESPECIALLY AS YOU
HEAD SOUTH TOWARDS THE MISSOURI RIVER. WENT AHEAD AND BUMPED UP
HIGHS A COUPLE TO SEVERAL DEGREES ACROSS THE AREA...WITH MID AND
EVEN A FEW UPPER 40S POSSIBLE FROM SIOUX CITY WEST TO GREGORY.
CLOUDS INCREASING ACROSS OUR NORTH...WITH PARTLY TO MOSTLY SUNNY
SKIES CONTINUING IN THE SOUTH. BACKDOOR COLD FRONT CURRENTLY
DROPPING SOUTH OUT OF WESTERN MINNESOTA AND NORTHEAST SOUTH DAKOTA.
WILL LIKELY SEE TEMPERATURES DROP QUICKLY INTO THE 20S AND TEENS
BEHIND THIS FRONT FROM NORTH TO SOUTH. LATEST RAP WOULD SUGGEST
FRONT PASSES THROUGH THE HIGHWAY 14 CORRIDOR NEAR 22Z...INTERSTATE
90 AROUND 0Z...AND OUR SOUTHERN COUNTIES CLOSER TO 3Z. COLDEST AIR
WILL ONLY CLIP OUR AREA...WITH THE BRUNT OF IT STAYING TO OUR EAST.
WATCHING SOME LIGHT SNOW BEHIND SURFACE FRONT ASSOCIATED WITH MID
LEVEL FRONTOGENESIS. BASED ON RADAR AND MODEL FORECASTS THINK MOST
OF THIS WILL STAY TO OUR NORTHEAST...ALTHOUGH COULD CLIP AREAS FROM
BROOKINGS TO MARSHALL WITH SOME LIGHT SNOW OF A COUPLE TENTHS.
ELSEWHERE....ALONG AND NORTH OF INTERSTATE 90 MAINLY JUST THINKING
SOME FLURRIES AT MOST. /CHENARD
.PREVIOUS DISCUSSION.../ISSUED AT 340 AM CST/
WEAK UPPER LEVEL SUPPORT WILL SPREAD ACROSS THE AREA
TODAY...CREATING CLOUD COVER BUT LITTLE INT HE WAY OF SNOWFALL. JUST
ENOUGH LOWER TO MID LEVEL MOISTURE WILL EXIST HOWEVER THAT FLURRIES
AND SOME LIGHT SNOW WILL BE POSSIBLE IN THE NORTHEAST HALF OF THE
CWA. PARTS OF SOUTHWEST MINNESOTA COULD RECEIVE A COUPLE OF TENTHS
OF AN INCH. OTHERWISE...TEMPERATURES HAVE WARMED QUITE A BIT
OVERNIGHT WITH A NICE MIXING WESTERLY WIND AHEAD OF THE COLDER DRIER
AIR EXPECTED TO ADVECT INTO THE AREA FROM THE NORTH. THIS WILL ALLOW
FOR A MILD DAY ACROSS THE AREA EVEN WITH CLOUD COVER...WITH HIGHS
RANGING FROM THE MID 30S IN SOUTHWEST MINNESOTA TO 40 TO 45 ALONG
THE MISSOURI RIVER.
A WEAK RIDGE OF COLD HIGH PRESSURE WILL SETTLE SOUTH TONIGHT WHICH
WILL ALLOW FOR SOME COLD OVERNIGHT LOW TEMPERATURES. WINDS WILL NOT
BE EXCESSIVE OVERNIGHT...BUT COULD DROP WIND CHILL VALUES TO 5 TO 10
BELOW ZERO OVER PARTS OF SOUTHWEST MINNESOTA. SNOWFALL IS NOT
EXPECTED AS SUBSIDENCE FILLS IN BEHIND TODAYS UPPER LEVEL WAVE. LOWS
OVERNIGHT WILL RANGE FROM AROUND 5 ABOVE IN SOUTHWEST MINNESOTA TO
NEAR 20 ALONG THE MISSOURI RIVER.
MIXING WILL BE A BIT LIMITED ON THURSDAY AS A RIDGE OF HIGH PRESSURE
REMAINS IN PLACE OVER THE EASTERN PART OF THE CWA. THIS WILL KEEP
TEMPERATURES A LITTLE COLDER...BUT STILL CLOSE TO NORMAL OVER
SOUTHWEST MINNESOTA...MAINLY IN THE MID 20S. FARTHER SOUTH AND WEST
TEMPERATURES WILL REBOUND A BIT AND CLIMB TO 35 TO 40 DEGREES.
THURSDAY NIGHT INTO FRIDAY WILL SEE A MILD AIR MASS DEVELOP WITH
SOUTHERLY WIND FRIDAY NIGHT...BECOMING WESTERLY ON FRIDAY. THIS IS
OF COURSE A FAVORABLE WIND DIRECTION SO EXPECT MORNING LOWS IN THE
TEENS AND FRIDAY HIGHS FROM ABOUT 35 TO 45 DEGREES.
IN THE LATTER PERIODS (SAT/TUE)...SATURDAY LIKELY TO BE THE LAST
MILD DAY FOR AWHILE...AND EVEN THAT IS A LITTLE QUESTIONABLE AS ALL
OF THE MODELS HAVE A COLD FRONT SURGING THROUGH BETWEEN 18Z AND 0Z
SO ANY MINOR INCREASE IN SPEED AND SATURDAY WILL BE MUCH COLDER. A
SLIGHT MODERATION IN TEMPERATURES ON SUNDAY AS A WAVE MOVES NORTH OF
THE AREA WHICH WILL BRIEFLY LIGHTEN WINDS OR TURN THEM A BIT
SOUTHERLY THEN DRAG DOWN THE COLDEST AIR OF THE SEASON SUNDAY NIGHT.
SOME DIFFERENCES IN SPEED BUT NOT MUCH DIFFERENCE IN HOW COLD BEHIND
THE FRONT SO SOME CONFIDENCE IN OVERALL TEMPERATURE FORECAST SUNDAY
THROUGH TUESDAY...WHICH WILL BE QUITE A BIT BELOW NORMAL. IF
EVERYTHING PANS OUT MORE THAN LIKELY WILL SEE A PERIOD OF LIGHT SNOW
ON SUNDAY THEN EITHER A WIND CHILL ADVISORY OR WIND CHILL WARNING
SUNDAY NIGHT THROUGH MONDAY EVENING. HIGH PRESSURE IS EXPECTED TO
BUILD SOUTH ON MONDAY NIGHT SO WINDS WILL GO LIGHT AND IF THERE IS
ANY FRESH SNOW COVER TUESDAY MORNING LOWS WILL BE QUITE COLD. /08
&&
.AVIATION.../FOR THE 12Z TAF ISSUANCE/
BAND OF MVFR CEILINGS AND GENERALLY VFR VISIBILITY WITH FLURRIES
WILL CONTINUE TO PROGRESS THROUGH SOUTHEAST HALF OF THE FORECAST
AREA EARLY THIS MORNING. POTENTIAL FOR MVFR CONDITIONS SHOULD PASS
THROUGH KSUX FOR FIRST COUPLE HOURS OF THIS TAF PERIOD...OTHERWISE
EXPECTING VFR CONDITIONS TO PREVAIL AT TAF LOCATIONS UNTIL LATE THIS
AFTERNOON BEHIND COLD FRONT WHICH WILL PUSH BACK SOUTH THROUGH THE
REGION. PERIODS OF MVFR CEILINGS MORE LIKELY TO LINGER IN SOUTHWEST
MINNESOTA ALONG/EAST OF THE BUFFALO RIDGE THIS MORNING...WITH MVFR
AND EVEN SOME IFR CEILINGS SPREADING BACK ACROSS THE FORECAST AREA
NORTH TO SOUTH DURING THE LATE AFTERNOON/EVENING BEHIND THE COLD
FRONT.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
916 PM MST TUE JAN 15 2013
.UPDATE...04Z SURFACE ANALYSIS HAD WARM FRONT FROM CENTRAL ND INTO
WESTERN NE. STRONG WARM AIR ADVECTION/BAND OF FRONTOGENESIS HAS
BROUGHT -SHSN TO MUCH OF THE CWA THIS EVENING...WITH TAIL END OF
MOISTURE STARTING TO BE SEE OVER MT/ND PER BOWMAN RADAR. UPSLOPE
-SHSN STILL PULSING OVER THE BLACK HILLS...BUT THAT SHOULD END IN
A COUPLE OF HOURS. 30-45KT LOW LEVEL WINDS NOTED ON KUNR/UPSTREAM
SOUNDINGS AS WELL AS LATEST RAP/NAM GUIDANCE. NOT EVERYTHING
REACHING THE GROUND WITH BOUNDARY LAYER PARTIALLY DECOUPLED AND
WARM AIR ADVECTION. DO NEED TO UP WINDS SOME THOUGH...BASED ON
LATEST TRENDS. HAVE ALSO ADJUSTED POPS FOR RADAR/TEMPERATURE TRENDS.
WILL ALLOW ADVISORY OVER THE BLACK HILLS TO EXPIRE ON SCHEDULE
GIVEN ABOVE THINKING.
&&
.AVIATION...06Z TAFS
IFR CIGS/VSBYS ASSOCIATED WITH -SHSN WILL EXIT THE CWA BY 09Z.
BEHIND IT...VFR CONDITIONS WILL DEVELOP WITH CIGS FROM 4-8KFT
RISING TO AC/CI LEVEL WEDNESDAY.
.PREV DISCUSSION... /ISSUED 250 PM MST TUE JAN 15 2013/
DISCUSSION...VIGOROUS DEEP LAYER WAA AND HEIGHT RISES ONGOING
ACROSS THE FA...WITH UPSLOPE ENHANCEMENT BEGINNING TO REV UP. POTENT
UPPER LEVEL RIDGING AND ASSOCIATED WAA WILL CONTINUE THROUGH MOST OF
THE PERIOD...ALTHOUGH A PASSING NORTHERN STREAM DISTURBANCE WILL
OFFER A SHORT LULL IN WAA ACROSS THE NORTHERN HALF OF THE FA
WED...WITH WAA BEGINNING TO SPREAD OVER THE REGION AGAIN WED NIGHT
THUR AS THE REGION REMAINS ON THE WARM SIDE OF A VERY STRONG
BAROCLINIC ZONE. NEAR SATURATED WAA WILL CONTINUE THROUGH THIS
EVENING...BEFORE DRIER AIR ADVECTS INTO THE FA...SUPPORTING AN END
TO UPGLIDE/UPSLOPE INDUCED SNOW.
STRONG LOW CENTERED OMEGA MAX IS OFFERING STAUNCH LOW LEVEL LIFT IN
A NEAR SATURATED BL...WITH A RISING FROUDE NUMBER IN THE NORTHERN
BLACK HILLS. RAP POINT SOUNDINGS IN FAR WESTERN LAWRENCE COUNTY
INDICATE A DEEPLY SATURATED BL. HOWEVER...WAA IS SHUNTING THE LAYER
OF MAXIMUM OMEGA OUT OF THE DGZ INTO INCREASINGLY WARMER AIR. THIS
HAS ALLOWED THE PRODUCTION OF FREEZING DRIZZLE AT TIMES...WHICH IS
EXPECTED TO MIX WITH UPSLOPE SNOWS THROUGH THE AFTERNOON/EVENING..AS
LL PROFILES WARM AND MID LEVEL DRYING COMMENCES. SNOW MAY MIX WITH
OR CHANGE OVER TO ALL FREEZING DRIZZLE AT TIMES...ESP WITH
OSCILLATING INTENSITY OF UPSLOPE ENHANCEMENT AND ANY SEEDER-FEEDER
PROCESS. STILL EXPECT ANOTHER 1-3 INCHES THROUGH THE EVENING IN TH
ADV...WITH LOCALLY HIGHER AMOUNTS WHERE SNOW PERSISTS...ALTHOUGH ZL
MIXING MAY LIMIT SNOWS SIG IN SOME AREAS. WILL KEEP THE ADV GOING
THROUGH THE CURRENT EXPIRATION TIME.
BREEZY CONDITIONS CAN BE EXPECTED THROUGH WED GIVEN THE LL BAROCLINIC
ZONE IN PLACE ACROSS THE REGION/EXPECTED PRESSURE FALLS...ALTHOUGH
WAA WILL OFFSET THE INTENSITY OF WINDS TONIGHT. A LITTLE BETTER
MIXING AND WEAK CAA ACROSS THE NORTH WILL ALLOW FOR BREEZY
CONDITIONS OVER THE SD PLAINS ON WED.
DRIER AIR WILL WORK INTO THE AREA...WITH SIG AMOUNTS OF HIGH CLOUDS
EXPECTED TO REMAIN GIVEN THE LOCATION OF THE UPPER JET. IN
ADDITION...A WEAK SECONDARY COLD FRONT/TROUGH WILL ADVECT THROUGH
THE AREA...SUPPORTING SOME MID CLOUD ACROSS THE NORTH...WITH
DECREASING CLOUDS THROUGH THE WED PERIOD. ALTHOUGH VERY WARM
PROFILES ARE PROGGED JUST ABOVE THE SFC...HIGH CLOUD COVER MAY LIMIT
T RISES TO A POINT WED...ESP AWAY FROM DOWNSLOPE AREAS AND WHERE A
DEEPER SNOW PACK IS IN PLACE. LOWS WILL REMAIN TRICKY...ESP WED
NIGHT WHEN WAA AND A LINGERING PRESSURE GRADIENT IN PLACE IS
ALLOWING SOME MODEL PROGS TO FORECAST MUCH WARMER TEMPS THAN SOME
OTHER SOLUTIONS. HAVE SIDED SOME TOWARD THIS WARMER SOLUTION WHICH
HAS BEEN EVIDENT THE LAST SEVERAL RUNS...ALTHOUGH QUESTIONS ON SNOW
COVER AND DECOUPLING REMAIN. HAVE INCORPORATED SOME DOWNSLOPE
EFFECTS ON THUR/S HIGHS WHICH WILL AGAIN REMAIN TRICKY.
EXTENDED...FAST NORTHWEST FLOW WILL CONTINUE OVER THE NORTHERN
PLAINS THROUGH EARLY NEXT WEEK. THE FORECAST AREA WILL REMAIN UNDER
THE INFLUENCE OF THE WESTERN RIDGE FOR ONE MORE DAY ON FRIDAY...WITH
DRY CONDITIONS AND MILD TEMPERATURES. CHANGES WILL COME THIS WEEKEND
AS A COMPACT SHORTWAVE DIVES THROUGH NORTHERN MINNESOTA...DRAGGING A
STRONG COLD FRONT ACROSS THE DAKOTAS FRIDAY NIGHT INTO SATURDAY.
TEMPERATURES WILL COOL DRAMATICALLY BY SUNDAY AND MONDAY AS ARCTIC
AIR SETTLES ACROSS THE NORTHERN PLAINS. ANOTHER WEAKER SHORTWAVE
WILL CROSS THE DAKOTAS ON SUNDAY...GIVING THE AREA A CHANCE FOR
LIGHT SNOW THROUGH SUNDAY NIGHT.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WINTER WEATHER ADVISORY UNTIL 11 PM MST THIS EVENING FOR CENTRAL
BLACK HILLS-NORTHERN BLACK HILLS.
WY...WINTER WEATHER ADVISORY UNTIL 11 PM MST THIS EVENING FOR WYOMING
BLACK HILLS.
&&
$$
SHORT TERM...WFO UNR
LONG TERM...WFO UNR
AVIATION...HELGESON
UPDATE...HELGESON
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
525 PM CST THU JAN 17 2013
.SHORT TERM...TONIGHT THROUGH SUNDAY
245 PM CST THU JAN 17 2013
FORECAST CONCERNS FOCUS ON THE SNOW CHANCES FOR LATE
TONIGHT/FRIDAY...THEN JUST HOW COLD IT WILL GET FOR EARLY NEXT WEEK.
A WARM FRONT WILL SLIDE WEST-EAST ACROSS THE UPPER MISSISSIPPI RIVER
VALLEY EARLY FRIDAY MORNING. STRONG LOW LEVEL WARMING AHEAD OF THE
BOUNDARY...ALONG WITH ISENTROPIC UPGLIDE ON THE 275-290 K SFCS. A
NARROW...BUT ALSO RELATIVELY STRONG BAND OF 2-D FRONTOGENETIC LIFT
IS ALSO INDICATED ALONG AND AHEAD OF THE FRONT...MOSTLY IN THE
900-800 MB LAYER. NO TAP INTO GULF MOISTURE...BUT BOTH THE 17.12Z
GFS AND NAM INDICATE THE FRONT WILL BRING ENOUGH SATURATION WITH IT
FOR THE FORCING TO WORK ON. SNOW LOOKS LIKE A GOOD BET AS A
RESULT...WITH THE MOST FAVORABLE AREA ALONG AND NORTH OF I-94. IT
MOVES THROUGH FAIRLY QUICKLY...BUT COULD STILL LAY DOWN AN INCH OR
TWO BEFORE IT EXITS EAST. COBB OUTPUT AGREES WITH THIS. WILL
INCREASE POPS FOR OVERNIGHT THROUGH FRIDAY MORNING...ADDING IN THESE
MINOR ACCUMULATIONS. SOME INDICATIONS THAT THERE COULD BE A BRIEF
PERIOD OF FREEZING DRIZZLE/DRIZZLE AS THE PCPN IS ENDING.
TIME/HEIGHT X-SECTIONS AND BUFKIT SOUNDINGS POINT TO SOME MID LEVEL
DRYING...WHILE KEEPING THE NEAR SFC SATURATION ALONG WITH
THERMODYNAMIC FORCING. DRIZZLE WOULD BE THE PCPN TYPE WITH THE LOSS
OF ICE IN THE CLOUD...AND FREEZING DEPENDING ON SFC TEMPS. IT SHOULD
BE NOTED THAT WHILE PCPN AMOUNTS ARE EXPECTED TO BE
MINOR...TRAVEL...INCLUDING THE MORNING COMMUTE FRIDAY...WILL BE
IMPACTED FOR SOME LOCATIONS.
A SHORTWAVE TROUGH WILL DROP ACROSS THE REGION ON SATURDAY...WITH
THE SFC LOW MOVING WEST-EAST ACROSS NORTHERN MN/NORTHERN GREAT
LAKES. A COLD FRONT WILL PUSH ACROSS THE AREA AROUND 12Z SAT...WITH
A SECONDARY FRONT/TROUGH MOVING THROUGH AROUND 00Z SUN. NOT MUCH RH
WITH THE FIRST FRONT...SO IT SHOULD MOVE THROUGH DRY. SOME
SATURATION PER TIME/HEIGHT X-SECTIONS AND BUFKIT SOUNDINGS WITH THE
SECOND FRONT...BUT GENERALLY CONFINED BELOW 850 MB. WITH AMPLE COLD
AIR THOUGH...THERE WOULD BE ICE AND ANY PCPN AROUND THIS BOUNDARY
SHOULD BE FLURRIES/LIGHT SNOW. THESE CHANCES WILL HOLD MOSTLY NORTH
OF THE FORECAST AREA.
SPEAKING OF THE COLD AIR...850 MB TEMPS DROP THROUGH THE DAY
SAT...FROM 2 C AT 12Z TO -16 BY 00Z. THIS FLUX OF COLD AIR COULD
RESULT IN A STEADY/FALLING TEMP SCENARIO FOR THE DAY SATURDAY...WITH
THE HIGH IN THE MORNING.
ANOTHER SHORTWAVE WILL FOLLOW QUICKLY IN THE WAKE OF THE SAT
SYSTEM...DROPPING ACROSS IA SUNDAY AFTERNOON. ENOUGH SATURATION THAT
THIS SYSTEM SHOULD PRODUCE SOME LIGHT SNOW/FLURRIES.
.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY
245 PM CST THU JAN 17 2013
EXTENDED FORECAST IS ALL ABOUT THE EXPECTED COLD. GOOD AGREEMENT
WITH THE MODELS THAT COLD AIR WILL PLUNGE SOUTHWARD ACROSS THE
REGION FOR THE EARLY PART OF THE NEW WORK WEEK...WITH 850 MB TEMPS
FROM -22 TO -24 FROM SUNDAY NIGHT THROUGH TUE. ECMWF 850 MB TEMP
ANOMALIES ARE AROUND -2 FOR MON-TUE. A SFC HIGH BUILDS ACROSS THE
UPPER MISSISSIPPI RIVER VALLEY ON TUE...WITH CLEAR SKIES/LIGHT WINDS
RESULTING IN GOOD RADIATIONAL COOLING. IF THERE WAS SNOW
COVER...TEMPS WOULD PROBABLY BE 10 DEGREES COLDER. AS IT
STANDS...HIGHS WILL STRUGGLE TO REACH ZERO ON MONDAY FOR NORTHERN
LOCATIONS. WINDS LOOK TO STAY UP ENOUGH THAT WIND CHILLS WILL BE A
CONCERN SUNDAY NIGHT/MONDAY MORNING. ADVISORIES ARE LIKELY.
TUESDAY...ALTHOUGH EXPECTED TO BE COLDER...WINDS DO NOT LOOK TO BE
AS BIG OF A FACTOR.
FOR PCPN CHANCES...GFS AND ECMWF SUGGEST AN UPPER LEVEL SHORTWAVE
WILL SLIDE ACROSS THE PLAINS AND OVER IOWA MON NIGHT/TUE. SOME LIGHT
QPF IS PRODUCED...BUT IT MOVES IN AND OUT RATHER QUICKLY. A STRONGER
TROUGH IS SLATED TO MOVE OVER THE UPPER MISSISSIPPI RIVER VALLEY ON
THU...WITH THE SFC LOW SKIRTING SOUTHERN PORTIONS OF THE FORECAST
AREA. DECENT AGREEMENT WITH 12Z RUNS OF THE GFS AND EC WITH THIS
SYSTEM...ALTHOUGH THEY DIFFERED IN PREVIOUS RUNS. CURRENT TRACK
WOULD BRING A PRETTY GOOD SHOT FOR PCPN. WILL STICK WITH CONSENSUS
FOR PCPN CHANCES.
&&
.AVIATION...TONIGHT AND FRIDAY
525 PM CST THU JAN 17 2013
SURFACE HIGH PRESSURE WILL SLIDE EAST OF THE TAF SITES
TONIGHT...WITH WARM ADVECTION AHEAD OF THE NEXT SHORTWAVE
SPREADING ACROSS THE AREA. THIS WAVE WILL RESULT IN A BAND OF SNOW
PUSHING ACROSS THE AREA AFTER 06Z TONIGHT. BEST CHANCE FOR ANY
SNOW WILL BE AT KLSE. NONE THE LESS...EXPECT CEILINGS AT BOTH SITES TO
DROP INTO THE IFR/MVFR CATEGORY AFTER 08Z TONIGHT WITH SNOW
SPREADING INTO THE REGION. DID ADD A TEMPO GROUP TO KRST AS KRST
WILL BE ON THE SOUTHWESTERN FRINGE OF THE PRECIPITATION AREA. THERE IS A
CONCERN THAT A SHORT PERIOD OF FREEZING DRIZZLE WILL BE POSSIBLE
AS THE PRECIPITATION ENDS. RAP AND NAM BUFKIT SOUNDINGS SHOWS A
LOSS OF ICE CRYSTALS IN THE CLOUD LAYER. THE MOST LIKELY TIME
FRAME FOR ANY FREEZING DRIZZLE WOULD BE BETWEEN 11Z-13Z AT KRST
AND 13Z-15Z AT KLSE. CONFIDENCE NOT HIGH ENOUGH AT THIS POINT TO
INCLUDE IT IN THE FORECAST. CEILINGS SHOULD RISE AFTER 18Z FRIDAY
WITH CLOUDS SCATTERING OUT DURING THE AFTERNOON HOURS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
245 PM CST THU JAN 17 2013
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RIECK
LONG TERM....RIECK
AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1140 AM CST WED JAN 16 2013
.SHORT TERM...THROUGH THIS EVENING
1026 AM CST WED JAN 16 2013
UPDATED FORECAST TO EXTEND FREEZING DRIZZLE / LIGHT SNOW ACROSS
THE EASTERN FORECAST AREA THROUGH NOON AS POCKETS OF PRECIPITATION
CONTINUE TO MOVE EAST. DUAL POL RETURNS SUGGEST THE MAJORITY OF
THE PRECIPITATION IS LIGHT SNOW...BUT IN BETWEEN THE POCKETS OF
HIGHER REFLECT IVIES...THE PTYPE MAY BE A LIGHT MIST OR DRIZZLE.
THIS HAS CAUSED SLICK SPOTS WITH SOME ACCIDENTS ACROSS THE AREA.
THE FOCUS FOR THE PRECIPITATION IS THE SURFACE BOUNDARY DRAPED JUST
OFF TO THE NORTHWEST...AND THIS WILL MOVE THROUGH DURING THE
AFTERNOON HOURS.
FOR LATE THIS AFTERNOON INTO THE EARLY EVENING...A SECONDARY
SHORTWAVE TROUGH DIPS THROUGH THE FLOW AND INTERACTS SOMEWHAT
WITH THE LINGERING SURFACE BOUNDARY FROM THIS MORNING. UPSTREAM
OBSERVATIONS SHOW 1 TO 2SM LIGHT SNOW ACROSS THE EASTERN DAKOTAS
AND THIS PRECIPITATION WILL SLIDE SOUTH/EAST...ARRIVING IN THE
NORTHWEST FORECAST AREA BY MID AFTERNOON. HAVE INCREASED CHANCES
ACROSS MOST OF THE AREA...WITH THE IDEA THAT THE ACTIVITY WILL BE
MAINLY LIGHT WITH ONLY 1/10 TO 3/10 OF AN INCH OF SNOW EXPECTED.
HOWEVER...TIMING WILL BE RIGHT AROUND THE EVENING COMMUTE SO THERE
COULD BE SOME TRAVEL CONCERNS AS PEOPLE HEAD HOME FROM WORK AND
SCHOOL. SOUNDINGS LOOK TO SUPPORT ALL SNOW...SO HAVE NOT
INTRODUCED ANY FREEZING DRIZZLE AT THIS TIME. THE HIGHER CHANCES
LOOK TO BE ALONG AND WEST OF THE MISSISSIPPI RIVER AND THE LATEST
HI-RES MESO MODELS AND THE 16.15Z RAP HANDLE THIS FAIRLY WELL...SO
HAVE TRENDED TOWARD THEIR SOLUTIONS.
.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY
355 AM CST WED JAN 16 2013
ON FRIDAY NIGHT...A COLD FRONT WILL BRIEFLY SURGE SOUTHWARD INTO
THE AREA AND THEN MOVE BACK NORTH AS A WARM FRONT AS A LOW
PRESSURE SYSTEM MOVES INTO NORTHWEST MINNESOTA. THE 275-285K
ISENTROPIC SURFACES SHOW THAT IT WILL TAKE 50 TO 100 MB FOR
SATURATION TO OCCUR. AS A RESULT...KEPT THE FORECAST DRY FOR NOW.
HIGH TEMPERATURES ON SATURDAY WILL RANGE FROM THE MID 20S TO MID 30S.
FROM LATE SATURDAY AFTERNOON INTO SATURDAY NIGHT...AN ARCTIC COLD
FRONT WILL MOVE SOUTH THROUGH THE FORECAST AREA. THE BEST MOISTURE
AND LIFT LOOKS TO BE MAINLY ALONG AND NORTH OF THE INTERSTATE 94
CORRIDOR. DUE TO THIS...KEPT LIGHT SNOW CHANCES MAINLY CONFINED
TO THIS AREA. LIKE LAST NIGHT...THE MODEL SOUNDINGS CONTINUE TO
SUGGEST THAT THE WINDS MAY BRIEFLY GUST INTO THE 35 TO 45 MPH
RANGE IN THE WAKE OF THIS FRONT.
ON SUNDAY NIGHT AND MONDAY MORNING...THE MODELS CONTINUE TO SHOW
THAT ANOTHER ARCTIC COLD FRONT WILL MOVE SOUTH THROUGH THE REGION.
THE GEM...GFS...AND ECMWF SUGGEST THAT SOME LIGHT SNOW WILL BE
ASSOCIATED WITH THIS FRONTAL PASSAGE. 850 MB TEMPERATURES ARE
AROUND 1.5 STANDARD DEVIATIONS BELOW NORMAL IN THE GFS AND AROUND
2 STANDARD DEVIATIONS BELOW NORMAL IN THE ECMWF. IT LOOKS LIKE
MUCH OF THE AREA WILL SEE HIGH TEMPERATURES REMAINING IN THE
SINGLE DIGITS. WIND CHILLS ON THIS MORNING LOOK TO BE IN THE 10 TO
20 BELOW RANGE.
ON MONDAY NIGHT...THE MODELS CONTINUE TO SHOW THAT LOW TEMPERATURES
WILL LIKELY RANGE FROM 5 TO 20 BELOW. WITH TEMPERATURES THIS COLD...
ANY WIND AT ALL WILL PRODUCE WIND CHILLS IN THE ADVISORY CRITERIA
/20 TO 35 BELOW/.
EARLY NEXT WEEK...THE MODELS CONTINUE TO SHOW THAT A STRONG SUDDEN
STRATOSPHERIC WARMING EVENT WILL TAKE PLACE ACROSS THE NORTH
CENTRAL PACIFIC. THIS WILL RESULT IN A LONG WAVE TROUGH QUICKLY
DEVELOPING ACROSS THIS AREA. THIS IS TURN WILL GIVE AN EASTERN
NUDGE TO THE LONG WAVE RIDGE ACROSS THE EAST PACIFIC AND WESTERN
NORTH AMERICA. AS THIS OCCURS...THE COLDEST AIR SHOULD START TO
SHIFT OUT OF THE AREA ON TUESDAY AND TUESDAY NIGHT. BOTH THE
DETERMINISTIC AND ENSEMBLE MEMBERS SHOW THIS OCCURRING...SO
CONFIDENCE IS FAIRLY HIGH THAT THIS LATEST BOUT OF ARCTIC AIR WILL
BE A SHORT LIVED.
&&
.AVIATION...THROUGH 18Z THURSDAY
1140 AM CST WED JAN 16 2013
A BRIEF PERIOD OF IMPROVED CONDITIONS EARLY THIS AFTERNOON AT
KRST/KLSE BEFORE ANOTHER SHORTWAVE TROUGH DIPS DOWN...BRINGING
LIGHT SNOW ALONG WITH A WIND SHIFT TO THE NORTHWEST. THIS WAVE
CURRENTLY BRINGING 1SM OR LESS VISIBILITIES WITH IFR
CEILINGS...AND TIMING PUTS THIS SNOW BAND AT KRST AROUND
20Z...AND 21Z AT KLSE. CEILINGS AND VISIBILITIES WILL BOUNCE AROUND
FOR A PERIOD LATE THIS AFTERNOON SO HAVE INCLUDED A TEMPO GROUP TO
REFLECT THIS. THE SYSTEM WILL BEGIN TO PUSH AWAY FROM THE TAF
SITES BETWEEN 01 AND 02Z. AFTER THAT...CONFIDENCE IS LOW ON
CEILINGS BUT HAVE REMAINED PESSIMISTIC WITH A MVFR DECK THROUGH
THE NIGHT. THERE REMAINS A CHANCE THAT CLOUDS WILL SCATTER OUT...BUT
THINK THAT WILL BE A SHORT-LIVED OPPORTUNITY BEFORE ADDITIONAL
CLOUDS STREAM IN.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
355 AM CST WED JAN 16 2013
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...ZT
LONG TERM...BOYNE
AVIATION...ZT
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1026 AM CST WED JAN 16 2013
.SHORT TERM...THROUGH THIS EVENING
1026 AM CST WED JAN 16 2013
UPDATED FORECAST TO EXTEND FREEZING DRIZZLE / LIGHT SNOW ACROSS
THE EASTERN FORECAST AREA THROUGH NOON AS POCKETS OF PRECIPITATION
CONTINUE TO MOVE EAST. DUAL POL RETURNS SUGGEST THE MAJORITY OF
THE PRECIPITATION IS LIGHT SNOW...BUT IN BETWEEN THE POCKETS OF
HIGHER REFLECT IVIES...THE PTYPE MAY BE A LIGHT MIST OR DRIZZLE.
THIS HAS CAUSED SLICK SPOTS WITH SOME ACCIDENTS ACROSS THE AREA.
THE FOCUS FOR THE PRECIPITATION IS THE SURFACE BOUNDARY DRAPED JUST
OFF TO THE NORTHWEST...AND THIS WILL MOVE THROUGH DURING THE
AFTERNOON HOURS.
FOR LATE THIS AFTERNOON INTO THE EARLY EVENING...A SECONDARY
SHORTWAVE TROUGH DIPS THROUGH THE FLOW AND INTERACTS SOMEWHAT
WITH THE LINGERING SURFACE BOUNDARY FROM THIS MORNING. UPSTREAM
OBSERVATIONS SHOW 1 TO 2SM LIGHT SNOW ACROSS THE EASTERN DAKOTAS
AND THIS PRECIPITATION WILL SLIDE SOUTH/EAST...ARRIVING IN THE
NORTHWEST FORECAST AREA BY MID AFTERNOON. HAVE INCREASED CHANCES
ACROSS MOST OF THE AREA...WITH THE IDEA THAT THE ACTIVITY WILL BE
MAINLY LIGHT WITH ONLY 1/10 TO 3/10 OF AN INCH OF SNOW EXPECTED.
HOWEVER...TIMING WILL BE RIGHT AROUND THE EVENING COMMUTE SO THERE
COULD BE SOME TRAVEL CONCERNS AS PEOPLE HEAD HOME FROM WORK AND
SCHOOL. SOUNDINGS LOOK TO SUPPORT ALL SNOW...SO HAVE NOT
INTRODUCED ANY FREEZING DRIZZLE AT THIS TIME. THE HIGHER CHANCES
LOOK TO BE ALONG AND WEST OF THE MISSISSIPPI RIVER AND THE LATEST
HI-RES MESO MODELS AND THE 16.15Z RAP HANDLE THIS FAIRLY WELL...SO
HAVE TRENDED TOWARD THEIR SOLUTIONS.
.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY
355 AM CST WED JAN 16 2013
ON FRIDAY NIGHT...A COLD FRONT WILL BRIEFLY SURGE SOUTHWARD INTO
THE AREA AND THEN MOVE BACK NORTH AS A WARM FRONT AS A LOW
PRESSURE SYSTEM MOVES INTO NORTHWEST MINNESOTA. THE 275-285K
ISENTROPIC SURFACES SHOW THAT IT WILL TAKE 50 TO 100 MB FOR
SATURATION TO OCCUR. AS A RESULT...KEPT THE FORECAST DRY FOR NOW.
HIGH TEMPERATURES ON SATURDAY WILL RANGE FROM THE MID 20S TO MID 30S.
FROM LATE SATURDAY AFTERNOON INTO SATURDAY NIGHT...AN ARCTIC COLD
FRONT WILL MOVE SOUTH THROUGH THE FORECAST AREA. THE BEST MOISTURE
AND LIFT LOOKS TO BE MAINLY ALONG AND NORTH OF THE INTERSTATE 94
CORRIDOR. DUE TO THIS...KEPT LIGHT SNOW CHANCES MAINLY CONFINED
TO THIS AREA. LIKE LAST NIGHT...THE MODEL SOUNDINGS CONTINUE TO
SUGGEST THAT THE WINDS MAY BRIEFLY GUST INTO THE 35 TO 45 MPH
RANGE IN THE WAKE OF THIS FRONT.
ON SUNDAY NIGHT AND MONDAY MORNING...THE MODELS CONTINUE TO SHOW
THAT ANOTHER ARCTIC COLD FRONT WILL MOVE SOUTH THROUGH THE REGION.
THE GEM...GFS...AND ECMWF SUGGEST THAT SOME LIGHT SNOW WILL BE
ASSOCIATED WITH THIS FRONTAL PASSAGE. 850 MB TEMPERATURES ARE
AROUND 1.5 STANDARD DEVIATIONS BELOW NORMAL IN THE GFS AND AROUND
2 STANDARD DEVIATIONS BELOW NORMAL IN THE ECMWF. IT LOOKS LIKE
MUCH OF THE AREA WILL SEE HIGH TEMPERATURES REMAINING IN THE
SINGLE DIGITS. WIND CHILLS ON THIS MORNING LOOK TO BE IN THE 10 TO
20 BELOW RANGE.
ON MONDAY NIGHT...THE MODELS CONTINUE TO SHOW THAT LOW TEMPERATURES
WILL LIKELY RANGE FROM 5 TO 20 BELOW. WITH TEMPERATURES THIS COLD...
ANY WIND AT ALL WILL PRODUCE WIND CHILLS IN THE ADVISORY CRITERIA
/20 TO 35 BELOW/.
EARLY NEXT WEEK...THE MODELS CONTINUE TO SHOW THAT A STRONG SUDDEN
STRATOSPHERIC WARMING EVENT WILL TAKE PLACE ACROSS THE NORTH
CENTRAL PACIFIC. THIS WILL RESULT IN A LONG WAVE TROUGH QUICKLY
DEVELOPING ACROSS THIS AREA. THIS IS TURN WILL GIVE AN EASTERN
NUDGE TO THE LONG WAVE RIDGE ACROSS THE EAST PACIFIC AND WESTERN
NORTH AMERICA. AS THIS OCCURS...THE COLDEST AIR SHOULD START TO
SHIFT OUT OF THE AREA ON TUESDAY AND TUESDAY NIGHT. BOTH THE
DETERMINISTIC AND ENSEMBLE MEMBERS SHOW THIS OCCURRING...SO
CONFIDENCE IS FAIRLY HIGH THAT THIS LATEST BOUT OF ARCTIC AIR WILL
BE A SHORT LIVED.
&&
.AVIATION...TODAY AND TONIGHT
521 AM CST WED JAN 16 2013
SOUTHWEST FLOW AHEAD OF THE SYSTEM MOVING INTO THE UPPER MIDWEST
IS STILL PRODUCING SOME WIND SHEAR AT KLSE. EXPECT THIS WILL
DISSIPATE BY MID MORNING AS A SURFACE TROUGH APPROACHES AND THE
WINDS ALOFT DECREASE AHEAD OF THIS FEATURE. CLOUDS AHEAD OF THE
SURFACE TROUGH INITIALLY START OUT VFR BUT THEN LOWER TO MVFR AS
IT GETS CLOSER. THE LIGHT SNOW THAT HAD BEEN ALONG THE SURFACE
TROUGH OVER SOUTH DAKOTA AND WESTERN MINNESOTA HAS
WEAKENED/DISSIPATED WITH JUST SOME FLURRIES LEFT. THE MAIN AREA OF
VISIBILITY REDUCING SNOW WILL PASS TO THE NORTH OF BOTH TAF SITES
CLOSER TO THE MAIN SURFACE LOW MOVING ACROSS SOUTHERN ONTARIO AND
LAKE SUPERIOR. THE WINDS WILL SWITCH TO THE WEST BEHIND THE
SURFACE TROUGH AND SWING AROUND TO THE NORTHWEST LATE THIS
AFTERNOON OR EARLY EVENING ONCE THE COLD FRONT GOES THROUGH. THE
MVFR CEILINGS SHOULD REMAIN IN PLACE BEHIND THE SURFACE TROUGH BUT
HOW LONG THEY HOLD ON BEHIND THE COLD FRONT IS UNKNOWN. CEILINGS
ARE PRIMARILY MVFR BACK ACROSS NORTH DAKOTA INTO MANITOBA AND
ALBERTA BUT THERE ARE SOME AREAS OF VFR AS WELL. FORECAST
SOUNDINGS FROM THE 16.06Z NAM SUGGESTS THAT DRIER AIR WILL MOVE IN
THIS EVENING AND ACTUALLY CLEAR SKIES OUT. HOWEVER...NOT CONFIDENT
ON THIS AS THE MODEL SHOWS DRY AIR CURRENTLY NEAR LAKE
WINNIPEG...WHERE SKIES ARE CLEAR...BUT MOVES THIS ACROSS THE GREAT
LAKES AND NOT OVER THE AREA THIS EVENING. WILL STAY PESSIMISTIC
AND KEEP CEILINGS MVFR UNTIL CLOUDS TRENDS BECOME MORE WELL
DEFINED.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
355 AM CST WED JAN 16 2013
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...ZT
LONG TERM...BOYNE
AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
521 AM CST WED JAN 16 2013
.SHORT TERM...TODAY THROUGH FRIDAY
355 AM CST WED JAN 16 2013
AT 3 AM...A SHORT WAVE TROUGH WAS MOVING SOUTHEAST ACROSS THE
NORTHERN TWO-THIRDS OF MINNESOTA AND NORTHWEST WISCONSIN. AREAS OF
SNOW IS BEING REPORTED ACROSS MINNESOTA AND EASTERN SOUTH DAKOTA.
THE 280-290K ISENTROPIC SURFACES SHOW THAT ONLY 10 MB OF LIFT WILL
BE NEEDED FOR SATURATION TO OCCUR. NEITHER THE NAM/WRF OR THE GFS
IS THAT IMPRESSIVE WITH THEIR OMEGA IN THE BUFKIT SOUNDINGS.
MEANWHILE THE RAP SHOWS THAT THERE WILL BE 5 TO 10 MICROBARS OF
LIFT. IN ADDITION...THE MESO MODELS SHOW THAT SOME LIGHT SNOW WILL
FALL ACROSS THE AREA. AREAS SOUTH OF THE INTERSTATE 94 CORRIDOR
WILL LIKELY ONLY SEE A DUSTING OF SNOW...SO KEPT PRECIPITATION
PROBABILITIES IN THE 20 TO 40 PERCENT RANGE. MEANWHILE NORTH OF
THIS AREA...THERE IS DEEPER MOISTURE AND STRONGER FORCING...SO
WENT WITH 50 TO 80 PERCENT PRECIPITATION PROBABILITIES. SNOWFALL
AMOUNTS IN THESE AREAS LOOK TO BE AROUND A HALF INCH.
DESPITE CLOUDS ACROSS THE AREA TODAY...TEMPERATURES WILL WARM
INTO THE 30S ACROSS THE AREA. LIKE THE PAST COUPLE OF THE
DAYS...THE NAM/WRF WAS INITIALIZED WITH WAY TOO MUCH SNOW COVER
ACROSS WISCONSIN /2 TO 8 INCHES/ AND EAST CENTRAL MINNESOTA /5 TO
8 INCHES/. SINCE THE MODEL IS TRYING TO MELT THIS SNOW...ITS
TEMPERATURES ARE TOO COLD...SO WENT WITH THE WARMER GFS AND ECMWF.
FOR THIS AFTERNOON AND EVENING...THE MODELS ARE SHOWING THAT THE
SECOND SHORT WAVE TROUGH IS MUCH WEAKER. AS A RESULT...THERE WILL
LIKELY NOT BE ENOUGH MOISTURE OF LIFT FOR ANOTHER ROUND OF SNOW TO
DEVELOP. LOOKING UPSTREAM...THERE IS NO PRECIPITATION ASSOCIATED
WITH THIS WAVE...THUS...TOOK OUT THE MENTION FOR PRECIPITATION.
FOR TONIGHT...A COLD FRONT WILL MOVE SOUTH THROUGH THE AREA. LOW
TEMPERATURES ON TUESDAY MORNING WILL RANGE 0 TO 15 DEGREES. THIS
IS CLOSE TO WHAT WE NORMALLY SEE IN MID-JANUARY.
ON THURSDAY NIGHT...THE MODELS CONTINUE TO SHOW THAT A WARM FRONT
WILL MOVE NORTH ACROSS THE AREA. THE GFS...GEM...AND ECMWF ARE IN
GOOD AGREEMENT THAT THERE WILL BE ENOUGH MOISTURE AND LIFT FOR
SOME LIGHT SNOW TO DEVELOP ALONG AND NORTH OF THE INTERSTATE 94
CORRIDOR. SNOWFALL AMOUNTS LOOK LIKE THEY WILL BE A HALF INCH OR
LESS.
ON FRIDAY...A LOW PRESSURE SYSTEM WILL MOVE ACROSS NORTHERN
MINNESOTA AND NORTHERN WISCONSIN. STRONG SOUTHWEST WINDS ALOFT
WILL BRING WARM AIR QUICKLY INTO THE REGION. IN ADDITION...THE
CLOUDS WILL DECREASING DURING THE DAY/ THE COMBINATION OF
SOUTHWEST WINDS...SUNSHINE...AND NO SNOW COVER...TEMPERATURES
SHOULD EASILY CLIMB INTO THE 30S AND LOWER 40S. IF THE ECMWF IS
CORRECT...THE TEMPERATURES MAY BE EVEN A COUPLE MORE DEGREES
WARMER. IT HAS BEEN SHOWING HIGHS IN THE LOWER AND MID 40S FOR THE
PAST 4 NIGHTS. AS STATED IN EARLIER...THE NAM/WRF HAS WAY TOO MUCH
SNOW ACROSS WISCONSIN...THUS...THREW OUT ITS MOS GUIDANCE.
.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY
355 AM CST WED JAN 16 2013
ON FRIDAY NIGHT...A COLD FRONT WILL BRIEFLY SURGE SOUTHWARD INTO
THE AREA AND THEN MOVE BACK NORTH AS A WARM FRONT AS A LOW
PRESSURE SYSTEM MOVES INTO NORTHWEST MINNESOTA. THE 275-285K
ISENTROPIC SURFACES SHOW THAT IT WILL TAKE 50 TO 100 MB FOR
SATURATION TO OCCUR. AS A RESULT...KEPT THE FORECAST DRY FOR NOW.
HIGH TEMPERATURES ON SATURDAY WILL RANGE FROM THE MID 20S TO MID 30S.
FROM LATE SATURDAY AFTERNOON INTO SATURDAY NIGHT...AN ARCTIC COLD
FRONT WILL MOVE SOUTH THROUGH THE FORECAST AREA. THE BEST MOISTURE
AND LIFT LOOKS TO BE MAINLY ALONG AND NORTH OF THE INTERSTATE 94
CORRIDOR. DUE TO THIS...KEPT LIGHT SNOW CHANCES MAINLY CONFINED
TO THIS AREA. LIKE LAST NIGHT...THE MODEL SOUNDINGS CONTINUE TO
SUGGEST THAT THE WINDS MAY BRIEFLY GUST INTO THE 35 TO 45 MPH
RANGE IN THE WAKE OF THIS FRONT.
ON SUNDAY NIGHT AND MONDAY MORNING...THE MODELS CONTINUE TO SHOW
THAT ANOTHER ARCTIC COLD FRONT WILL MOVE SOUTH THROUGH THE REGION.
THE GEM...GFS...AND ECMWF SUGGEST THAT SOME LIGHT SNOW WILL BE
ASSOCIATED WITH THIS FRONTAL PASSAGE. 850 MB TEMPERATURES ARE
AROUND 1.5 STANDARD DEVIATIONS BELOW NORMAL IN THE GFS AND AROUND
2 STANDARD DEVIATIONS BELOW NORMAL IN THE ECMWF. IT LOOKS LIKE
MUCH OF THE AREA WILL SEE HIGH TEMPERATURES REMAINING IN THE
SINGLE DIGITS. WIND CHILLS ON THIS MORNING LOOK TO BE IN THE 10 TO
20 BELOW RANGE.
ON MONDAY NIGHT...THE MODELS CONTINUE TO SHOW THAT LOW TEMPERATURES
WILL LIKELY RANGE FROM 5 TO 20 BELOW. WITH TEMPERATURES THIS COLD...
ANY WIND AT ALL WILL PRODUCE WIND CHILLS IN THE ADVISORY CRITERIA
/20 TO 35 BELOW/.
EARLY NEXT WEEK...THE MODELS CONTINUE TO SHOW THAT A STRONG SUDDEN
STRATOSPHERIC WARMING EVENT WILL TAKE PLACE ACROSS THE NORTH
CENTRAL PACIFIC. THIS WILL RESULT IN A LONG WAVE TROUGH QUICKLY
DEVELOPING ACROSS THIS AREA. THIS IS TURN WILL GIVE AN EASTERN
NUDGE TO THE LONG WAVE RIDGE ACROSS THE EAST PACIFIC AND WESTERN
NORTH AMERICA. AS THIS OCCURS...THE COLDEST AIR SHOULD START TO
SHIFT OUT OF THE AREA ON TUESDAY AND TUESDAY NIGHT. BOTH THE
DETERMINISTIC AND ENSEMBLE MEMBERS SHOW THIS OCCURRING...SO
CONFIDENCE IS FAIRLY HIGH THAT THIS LATEST BOUT OF ARCTIC AIR WILL
BE A SHORT LIVED.
&&
.AVIATION...TODAY AND TONIGHT
521 AM CST WED JAN 16 2013
SOUTHWEST FLOW AHEAD OF THE SYSTEM MOVING INTO THE UPPER MIDWEST
IS STILL PRODUCING SOME WIND SHEAR AT KLSE. EXPECT THIS WILL
DISSIPATE BY MID MORNING AS A SURFACE TROUGH APPROACHES AND THE
WINDS ALOFT DECREASE AHEAD OF THIS FEATURE. CLOUDS AHEAD OF THE
SURFACE TROUGH INITIALLY START OUT VFR BUT THEN LOWER TO MVFR AS
IT GETS CLOSER. THE LIGHT SNOW THAT HAD BEEN ALONG THE SURFACE
TROUGH OVER SOUTH DAKOTA AND WESTERN MINNESOTA HAS
WEAKENED/DISSIPATED WITH JUST SOME FLURRIES LEFT. THE MAIN AREA OF
VISIBILITY REDUCING SNOW WILL PASS TO THE NORTH OF BOTH TAF SITES
CLOSER TO THE MAIN SURFACE LOW MOVING ACROSS SOUTHERN ONTARIO AND
LAKE SUPERIOR. THE WINDS WILL SWITCH TO THE WEST BEHIND THE
SURFACE TROUGH AND SWING AROUND TO THE NORTHWEST LATE THIS
AFTERNOON OR EARLY EVENING ONCE THE COLD FRONT GOES THROUGH. THE
MVFR CEILINGS SHOULD REMAIN IN PLACE BEHIND THE SURFACE TROUGH BUT
HOW LONG THEY HOLD ON BEHIND THE COLD FRONT IS UNKNOWN. CEILINGS
ARE PRIMARILY MVFR BACK ACROSS NORTH DAKOTA INTO MANITOBA AND
ALBERTA BUT THERE ARE SOME AREAS OF VFR AS WELL. FORECAST
SOUNDINGS FROM THE 16.06Z NAM SUGGESTS THAT DRIER AIR WILL MOVE IN
THIS EVENING AND ACTUALLY CLEAR SKIES OUT. HOWEVER...NOT CONFIDENT
ON THIS AS THE MODEL SHOWS DRY AIR CURRENTLY NEAR LAKE
WINNIPEG...WHERE SKIES ARE CLEAR...BUT MOVES THIS ACROSS THE GREAT
LAKES AND NOT OVER THE AREA THIS EVENING. WILL STAY PESSIMISTIC
AND KEEP CEILINGS MVFR UNTIL CLOUDS TRENDS BECOME MORE WELL
DEFINED.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
355 AM CST WED JAN 16 2013
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
356 AM CST WED JAN 16 2013
.SHORT TERM...TODAY THROUGH FRIDAY
355 AM CST WED JAN 16 2013
AT 3 AM...A SHORT WAVE TROUGH WAS MOVING SOUTHEAST ACROSS THE
NORTHERN TWO-THIRDS OF MINNESOTA AND NORTHWEST WISCONSIN. AREAS OF
SNOW IS BEING REPORTED ACROSS MINNESOTA AND EASTERN SOUTH DAKOTA.
THE 280-290K ISENTROPIC SURFACES SHOW THAT ONLY 10 MB OF LIFT WILL
BE NEEDED FOR SATURATION TO OCCUR. NEITHER THE NAM/WRF OR THE GFS
IS THAT IMPRESSIVE WITH THEIR OMEGA IN THE BUFKIT SOUNDINGS.
MEANWHILE THE RAP SHOWS THAT THERE WILL BE 5 TO 10 MICROBARS OF
LIFT. IN ADDITION...THE MESO MODELS SHOW THAT SOME LIGHT SNOW WILL
FALL ACROSS THE AREA. AREAS SOUTH OF THE INTERSTATE 94 CORRIDOR
WILL LIKELY ONLY SEE A DUSTING OF SNOW...SO KEPT PRECIPITATION
PROBABILITIES IN THE 20 TO 40 PERCENT RANGE. MEANWHILE NORTH OF
THIS AREA...THERE IS DEEPER MOISTURE AND STRONGER FORCING...SO
WENT WITH 50 TO 80 PERCENT PRECIPITATION PROBABILITIES. SNOWFALL
AMOUNTS IN THESE AREAS LOOK TO BE AROUND A HALF INCH.
DESPITE CLOUDS ACROSS THE AREA TODAY...TEMPERATURES WILL WARM
INTO THE 30S ACROSS THE AREA. LIKE THE PAST COUPLE OF THE
DAYS...THE NAM/WRF WAS INITIALIZED WITH WAY TOO MUCH SNOW COVER
ACROSS WISCONSIN /2 TO 8 INCHES/ AND EAST CENTRAL MINNESOTA /5 TO
8 INCHES/. SINCE THE MODEL IS TRYING TO MELT THIS SNOW...ITS
TEMPERATURES ARE TOO COLD...SO WENT WITH THE WARMER GFS AND ECMWF.
FOR THIS AFTERNOON AND EVENING...THE MODELS ARE SHOWING THAT THE
SECOND SHORT WAVE TROUGH IS MUCH WEAKER. AS A RESULT...THERE WILL
LIKELY NOT BE ENOUGH MOISTURE OF LIFT FOR ANOTHER ROUND OF SNOW TO
DEVELOP. LOOKING UPSTREAM...THERE IS NO PRECIPITATION ASSOCIATED
WITH THIS WAVE...THUS...TOOK OUT THE MENTION FOR PRECIPITATION.
FOR TONIGHT...A COLD FRONT WILL MOVE SOUTH THROUGH THE AREA. LOW
TEMPERATURES ON TUESDAY MORNING WILL RANGE 0 TO 15 DEGREES. THIS
IS CLOSE TO WHAT WE NORMALLY SEE IN MID-JANUARY.
ON THURSDAY NIGHT...THE MODELS CONTINUE TO SHOW THAT A WARM FRONT
WILL MOVE NORTH ACROSS THE AREA. THE GFS...GEM...AND ECMWF ARE IN
GOOD AGREEMENT THAT THERE WILL BE ENOUGH MOISTURE AND LIFT FOR
SOME LIGHT SNOW TO DEVELOP ALONG AND NORTH OF THE INTERSTATE 94
CORRIDOR. SNOWFALL AMOUNTS LOOK LIKE THEY WILL BE A HALF INCH OR
LESS.
ON FRIDAY...A LOW PRESSURE SYSTEM WILL MOVE ACROSS NORTHERN
MINNESOTA AND NORTHERN WISCONSIN. STRONG SOUTHWEST WINDS ALOFT
WILL BRING WARM AIR QUICKLY INTO THE REGION. IN ADDITION...THE
CLOUDS WILL DECREASING DURING THE DAY/ THE COMBINATION OF
SOUTHWEST WINDS...SUNSHINE...AND NO SNOW COVER...TEMPERATURES
SHOULD EASILY CLIMB INTO THE 30S AND LOWER 40S. IF THE ECMWF IS
CORRECT...THE TEMPERATURES MAY BE EVEN A COUPLE MORE DEGREES
WARMER. IT HAS BEEN SHOWING HIGHS IN THE LOWER AND MID 40S FOR THE
PAST 4 NIGHTS. AS STATED IN EARLIER...THE NAM/WRF HAS WAY TOO MUCH
SNOW ACROSS WISCONSIN...THUS...THREW OUT ITS MOS GUIDANCE.
.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY
355 AM CST WED JAN 16 2013
ON FRIDAY NIGHT...A COLD FRONT WILL BRIEFLY SURGE SOUTHWARD INTO
THE AREA AND THEN MOVE BACK NORTH AS A WARM FRONT AS A LOW
PRESSURE SYSTEM MOVES INTO NORTHWEST MINNESOTA. THE 275-285K
ISENTROPIC SURFACES SHOW THAT IT WILL TAKE 50 TO 100 MB FOR
SATURATION TO OCCUR. AS A RESULT...KEPT THE FORECAST DRY FOR NOW.
HIGH TEMPERATURES ON SATURDAY WILL RANGE FROM THE MID 20S TO MID 30S.
FROM LATE SATURDAY AFTERNOON INTO SATURDAY NIGHT...AN ARCTIC COLD
FRONT WILL MOVE SOUTH THROUGH THE FORECAST AREA. THE BEST MOISTURE
AND LIFT LOOKS TO BE MAINLY ALONG AND NORTH OF THE INTERSTATE 94
CORRIDOR. DUE TO THIS...KEPT LIGHT SNOW CHANCES MAINLY CONFINED
TO THIS AREA. LIKE LAST NIGHT...THE MODEL SOUNDINGS CONTINUE TO
SUGGEST THAT THE WINDS MAY BRIEFLY GUST INTO THE 35 TO 45 MPH
RANGE IN THE WAKE OF THIS FRONT.
ON SUNDAY NIGHT AND MONDAY MORNING...THE MODELS CONTINUE TO SHOW
THAT ANOTHER ARCTIC COLD FRONT WILL MOVE SOUTH THROUGH THE REGION.
THE GEM...GFS...AND ECMWF SUGGEST THAT SOME LIGHT SNOW WILL BE
ASSOCIATED WITH THIS FRONTAL PASSAGE. 850 MB TEMPERATURES ARE
AROUND 1.5 STANDARD DEVIATIONS BELOW NORMAL IN THE GFS AND AROUND
2 STANDARD DEVIATIONS BELOW NORMAL IN THE ECMWF. IT LOOKS LIKE
MUCH OF THE AREA WILL SEE HIGH TEMPERATURES REMAINING IN THE
SINGLE DIGITS. WIND CHILLS ON THIS MORNING LOOK TO BE IN THE 10 TO
20 BELOW RANGE.
ON MONDAY NIGHT...THE MODELS CONTINUE TO SHOW THAT LOW TEMPERATURES
WILL LIKELY RANGE FROM 5 TO 20 BELOW. WITH TEMPERATURES THIS COLD...
ANY WIND AT ALL WILL PRODUCE WIND CHILLS IN THE ADVISORY CRITERIA
/20 TO 35 BELOW/.
EARLY NEXT WEEK...THE MODELS CONTINUE TO SHOW THAT A STRONG SUDDEN
STRATOSPHERIC WARMING EVENT WILL TAKE PLACE ACROSS THE NORTH
CENTRAL PACIFIC. THIS WILL RESULT IN A LONG WAVE TROUGH QUICKLY
DEVELOPING ACROSS THIS AREA. THIS IS TURN WILL GIVE AN EASTERN
NUDGE TO THE LONG WAVE RIDGE ACROSS THE EAST PACIFIC AND WESTERN
NORTH AMERICA. AS THIS OCCURS...THE COLDEST AIR SHOULD START TO
SHIFT OUT OF THE AREA ON TUESDAY AND TUESDAY NIGHT. BOTH THE
DETERMINISTIC AND ENSEMBLE MEMBERS SHOW THIS OCCURRING...SO
CONFIDENCE IS FAIRLY HIGH THAT THIS LATEST BOUT OF ARCTIC AIR WILL
BE A SHORT LIVED.
&&
.AVIATION...THROUGH 06Z THURSDAY
1141 PM CST TUE JAN 15 2013
FOCUS OF THIS FORECAST IS ON A LOW PRESSURE SYSTEM ENCOMPASSING
SOUTH CENTRAL CANADA INTO THE NORTHERN PLAINS.
PLENTY OF DRY AIR STILL EXISTS AHEAD OF THIS SYSTEM OVER THE
FORECAST AREA. THIS DRY AIR WILL HELP KEEP VFR CONDITIONS FOR
THE EARLY MORNING HOURS. SOUTH TO SOUTHWEST WINDS HAVE INCREASED
AHEAD OF THE SYSTEM...AT THE SURFACE AT KRST WHERE GUSTS ARE
UPWARDS OF 20-25 KT...AND AT 1000-15000 FT ABOVE THE SURFACE AT
KLSE WHERE WINDS ARE 40-45KT. LOOK FOR THESE CONDITIONS TO PERSIST
THROUGH THE EARLY MORNING HOURS.
A BAND OF SNOW ASSOCIATED WITH THE SYSTEM...CURRENTLY ACROSS
THE NORTH HALF OF MINNESOTA...IS FORECAST TO IMPACT THE TAF SITES
WEDNESDAY MORNING...BETWEEN 13-18Z. THE TAF SITES LOOK TO BE ON
THE LIGHTER SOUTHERN END OF THE BAND...THUS HAVE KEPT VISIBILITIES
AT MVFR. AT MOST A COUPLE TENTHS OF ACCUMULATION WOULD OCCUR WITH
THE SNOW. CEILINGS SHOULD QUICKLY DROP TO MVFR AS WELL WITH THE
BAND OF SNOW...WHICH THEN LOOK TO HANG AROUND THROUGH THE
AFTERNOON AND EVEN INTO THE EVENING. LOW LEVEL WIND SHEAR ENDS AT
KLSE AROUND THE TIME THE BAND OF SNOW MOVES IN...SINCE THE LOW
LEVEL JET PUSHES OFF TO THE EAST. PLAN ON THE WINDS TO TURN WEST
AND NORTHWESTERLY AS THE LOW PRESSURE SYSTEMS COLD FRONT MOVES
INTO THE TAF SITES IN THE AFTERNOON. WINDS SHOULD ALSO SLOWLY DECREASE
SINCE THE PRESSURE GRADIENT BEHIND THE COLD FRONT IS NOT AS TIGHT
AS WHAT IS CURRENTLY IN PLACE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
355 AM CST WED JAN 16 2013
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...AJ
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
913 PM MST THU JAN 17 2013
.SHORT TERM...VALID FOR FRI AND SAT...
WINDS WERE BELOW ADVISORY SPEEDS THIS EVENING IN THE KLVM AND BIG
TIMBER AREAS. MANUAL ANALYSIS OF THE SURFACE PRESSURE GRADIENT
REVEALED THAT THE GRADIENT WAS MUCH FLATTER THAN DEPICTED ON LAPS
OR THE MODELS DUE TO THE 1045 HIGH CENTERED OVER THE PARK. THE
STRENGTH OF THE GRADIENT BETWEEN KLWT AND KIDA WAS 26 MB AT 03Z.
GIVEN A MORE STABLE AIRMASS...THIS GRADIENT WOULD TYPICALLY
SUPPORT WARNING CRITERIA WIND SPEEDS AT KLVM AND NYE.
HOWEVER...THE LOW-LEVELS WERE A BIT UNSTABLE THIS EVENING. WHILE
THEY SHOULD STABILIZE A BIT OVERNIGHT PER RAP AND WRF BUFKIT
SOUNDINGS...ADVISORY CURRENTLY IN EFFECT SHOULD COVER THE
SITUATION. THE FLATTER GRADIENT MAY NOT ALLOW WIND SPEEDS TO REACH
ADVISORY CRITERIA AT BIG TIMBER. SINCE CURRENT WIND SPEEDS WERE
30-35 MPH IN THIS AREA...AND WITH AIRMASS STABILIZING A BIT MORE
OVERNIGHT...HAVE NO STRONG REASON TO CHANGE THE HIGHLIGHT IN THIS
AREA. LATEST MODELS SHOWED A STRONG PRESSURE GRADIENT PERSISTING
INTO FRI NIGHT WHEN A COLD FRONT BACKDOORS INTO THE AREA. THE
RELAXING GRADIENT WILL ALLOW WIND SPEEDS TO DIMINISH AT THAT TIME.
EXPECT WINDY CONDITIONS FROM KBIL W AHEAD OF THIS FRONT.
TEMPERATURES THIS EVENING WERE IN THE 30S TO LOWER 40S IN MOST
AREAS. HIGH CLOUDS WERE SINKING S THROUGH THE REGION PER IR
SATELLITE IMAGERY. COMBINATION OF WIND AND CLOUDS WILL KEEP
TEMPERATURES A BIT HIGHER THAN FORECAST SO HAVE RAISED MINS TOWARD
THE NEW METBC GUIDANCE. ALSO ADJUSTED CLOUD COVER ACROSS THE AREA.
NEW MODEL RUNS CONTINUED TO SUPPORT A WARM AND DRY DAY ON FRI WITH
850 MB TEMPERATURES AROUND +7 DEGREES C. ARTHUR
.LONG TERM...VALID FOR SUN...MON...TUE...WED...THU...
MINIMAL CHANGES TO THE EXTENDED PERIOD FORECAST THIS AFTERNOON.
MODELS REMAIN IN GOOD AGREEMENT THROUGH THE PERIOD. THE END OF
WORK WEEK WEATHER SYSTEM ALSO APPEARS TO BE COMING INTO BETTER
AGREEMENT WITH LATEST MODELS RUNS.
THE EXTENDED FORECAST BEGINS SUNDAY...AS A BACKDOOR FRONT PUSHES
INTO THE REGION. THIS DOES NOT APPEAR TO BE A SIGNIFICANTLY WET
SYSTEM...SO NOT EXPECTING A LOT OF ACCUMULATIONS...BUT CANNOT
RULE OUT SOME SNOW. THEREFORE...HAVE CONTINUED WITH GOING POPS AT
THIS TIME. THE TIMING OF THIS SYSTEM DOES APPEAR TO HAVE SPED UP
SLIGHTLY...AND THE ASSOCIATED SURFACE LOW APPEARS TO HAVE
STRENGTHENED A BIT AS WELL. ADDITIONALLY...THESE SYSTEMS SEEM TO
REACH THE MOUNTAINS MORE OFTEN THAN NOT AND SEEM TO BE SOMEWHAT
STUBBORN IN THEIR DEPARTURES...SO COOLED TEMPS FOR SUNDAY AND
MONDAY...ESPECIALLY ACROSS THE WEST...FROM KBIL TO THE MOUNTAINS.
THE NEXT SEVERAL DAYS WILL SEE A WARMING TREND UNDER PERSISTENT DRY
NORTHWEST FLOW...BEGINNING MONDAY. THERE WILL BE SEVERAL
SHORTWAVES THROUGH THE FLOW...BUT DRY CONDITIONS AND DOWNSLOPE
FLOW SHOULD LIMIT CLOUD DEVELOPMENT. TEMPS ARE PROGGED TO WARM UP
MUCH MORE QUICKLY THAN INDICATED IN THE INHERITED FORECAST. NOT
SEEING MUCH TO INHIBIT WARM UP WITH VERY LIMITED SNOW COVER AND
CLOUD COVER THROUGH THE PERIOD UNLESS THE COLD FRONT STALLS...SO
HAVE INCREASED TEMPS FOR TUESDAY AND WEDNESDAY...ESPECIALLY ON
WEDNESDAY IN ADVANCE OF NEXT APPROACHING WEATHER SYSTEM.
MODELS APPEAR TO BE COMING INTO BETTER AGREEMENT FOR ANOTHER BROAD
PACIFIC TROF TO PUSH THROUGH THE REGION BEGINNING LATE WEDNESDAY AND
THROUGH THURSDAY. CONTINUING WITH GOING POPS AT THIS
TIME. ALSO LOWERED TEMPS SLIGHTLY FOR THURSDAY...AS FRONT SHOULD
BE THROUGH BY THAT TIME. AAG
&&
.AVIATION...
SOUTHWEST WINDS WILL INCREASE OVER WESTERN ROUTES TONIGHT AND
CONTINUE INTO FRIDAY NIGHT. GUSTS WILL EXCEED 50KTS AT KLVM. GUSTS
WILL APPROACH 35KTS AT KBIL BY LATE FRIDAY MORNING. LLWS WILL ALSO
BE A CONCERN AT KSHR AND KMLS WITH INCREASING NORTHWEST WINDS
ALOFT. OTHERWISE...VFR CONDITIONS WILL PREVAIL THROUGH THE NIGHT
WITH JUST SOME MID AND HIGH LEVEL CLOUDINESS EXPECTED. TWH
&&
.PRELIMINARY POINT TEMP/POPS...
FRI SAT SUN MON TUE WED THU
-----------------------------------------------------------
BIL 031/051 023/029 009/022 008/027 018/039 023/042 024/035
00/N 00/B 03/S 21/N 10/N 01/B 22/J
LVM 034/048 026/038 012/027 015/032 021/040 024/040 021/033
00/N 00/N 02/S 21/N 10/N 02/S 23/J
HDN 024/050 019/029 006/020 003/024 014/038 018/041 022/035
00/N 00/B 13/S 21/B 11/B 01/B 23/J
MLS 025/046 016/017 000/013 905/017 010/031 015/036 020/033
00/B 00/B 23/S 22/B 21/B 01/B 23/J
4BQ 026/047 017/023 002/018 901/021 011/034 017/038 020/033
00/U 00/B 23/S 22/B 21/B 01/B 23/J
BHK 025/042 013/015 903/009 908/011 007/027 014/034 018/031
00/B 00/N 23/S 22/B 21/B 01/B 22/J
SHR 019/052 019/032 007/023 005/030 014/041 018/042 021/033
00/U 00/B 02/S 21/B 10/B 01/B 23/J
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...WIND ADVISORY IN EFFECT UNTIL 6 AM MST SATURDAY FOR ZONES
41-65-66.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1252 AM EST FRI JAN 18 2013
.SYNOPSIS...
AN INTENSE AND QUICK MOVING AREA OF LOW PRESSURE WILL BRING
WIND...RAIN AND A RETURN TO CHILLY TEMPERATURES OVERNIGHT. THE
WINTER CHILL WILL PERSIST INTO THE WEEKEND AND THEN PERIODICALLY
BE REINFORCED BY SUCCESSIVE DRY COLD FRONTS THROUGH MUCH OF
NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 12:45 AM FRIDAY...NO FURTHER REPORTS OF FROZEN PRECIP OVER
THE PAST HOUR. RADAR LOOPS SHOW ONE LAST BAND OF RAIN DROPPING SE
ACROSS THE COASTAL PLAIN. THIS WILL BE OFFSHORE WITHIN THE NEXT
COUPLE OF HOURS...FOLLOWED BY A BRIEF PERIOD OF DRIZZLE...THEN
RAPIDLY IMPROVING CONDITIONS. THAT IS...IF ONE CONSIDERS COLD AND
BREEZY TO BE AN IMPROVEMENT. PREVIOUS DISCUSSIONS FOLLOW:
BASED ON MULTIPLE REPORTS RELAYED THROUGH TV METEOROLOGISTS OF
SNOW MIXING WITH THE RAIN FARTHER SOUTH THAN ASOS/AWOS REPORTS HAD
INDICATED...I HAVE UPDATED THE FORECAST FOR THE NEXT 3-5 HOURS TO
INCLUDE MIXED PRECIP TYPES AS FAR SOUTH AS
DARLINGTON...DILLON...THE COLUMBUS/BLADEN COUNTY LINE...AND
BURGAW. THE LATEST SEVERAL RUC MODEL RUNS SHOW FREEZING LEVELS
SHOULD BE FALLING BELOW 2000 FT AGL SHORTLY IN THE BENNETTSVILLE
AND LUMBERTON AREAS WHICH MAY SUPPORT MORE SNOW MAKING IT TO THE
SURFACE. MY THOUGHTS STILL HAVE NOT CHANGED WITH RESPECT TO THE
VERY LOW LIKELIHOOD OF ANY ACCUMULATIONS REGARDLESS OF HOW MUCH
SNOW MIXES IN. PREVIOUS DISCUSSION FROM 1000 PM FOLLOWS...
THE COLD FRONT IS NOW WELL OFFSHORE. THE BAND OF HEAVY RAINFALL AND
EMBEDDED CONVECTION WITHIN THE ENHANCED ZONE OF ASCENT IS OFFSHORE
TOO. ATTENTION NOW TURNS TO THE UPPER LEVEL LOW CURRENTLY OVER
UPSTATE SOUTH CAROLINA. THIS SWIRLING BALL OF COLD AIR ALOFT IS
FORECAST BY ALL MODEL GUIDANCE TO MOVE NORTHEASTWARD TO THE SOUTHERN
CHESAPEAKE BAY BY 3-5 AM. STEEP LAPSE RATES ALOFT AND DEEP MOISTURE
ASSOCIATED WITH THIS LOW ARE PRODUCING WIDESPREAD LIGHT
PRECIPITATION EXTENDING FROM UPSTATE SOUTH CAROLINA ACROSS THE
WESTERN TWO-THIRDS OF NORTH CAROLINA. UNDERNEATH THIS UPPER
SYSTEM...COLD AIR BEING PULLED SOUTH BEHIND THE DEPARTING SURFACE
LOW HAS CHANGED RAIN OVER TO SNOW ALONG AND NORTH OF A LINE FROM
JUST NORTH OF CHARLOTTE TO ASHEBORO TO RALEIGH. WHILE THE CHANCES
FOR MEASURABLE SNOW HAVE NEVER BEEN GOOD IN OUR FORECAST
AREA...THERE REMAINS A SMALL POTENTIAL THAT THE RAIN COULD END MIXED
WITH SNOW ACROSS BENNETTSVILLE...LUMBERTON AND ELIZABETHTOWN AFTER
MIDNIGHT. NO ACCUMULATIONS ARE EXPECTED DUE TO ABOVE-FREEZING AIR
TEMPERATURES AND WELL-ABOVE FREEZING GROUND TEMPERATURES.
ALSO...I SPOKE TO A REPRESENTATIVE WITH THE EMERGENCY MANAGEMENT
AGENCY IN COLUMBUS COUNTY WHO REPORTED FAIRLY WIDESPREAD AND
SUBSTANTIAL DAMAGE FROM THE LINE OF SHOWERS THAT MOVED THROUGH THERE
AROUND 645 PM. WE WILL BE SENDING A STORM SURVEY TEAM OUT TO THE
CHADBOURN COMMUNITY IN WESTERN COLUMBUS COUNTY TOMORROW MORNING TO
SURVEY AND CLASSIFY THE DAMAGE THERE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY NIGHT/...
AS OF 2 PM THURSDAY...WINTER IS BACK. IT WILL BE A CHILLY AND
BRISK START TO THE DAY FRI AS THE PRESSURE GRADIENT WILL REMAIN
RATHER TIGHT BETWEEN STRONG HIGH PRESSURE ACROSS THE OHIO AND
TENNESSEE VALLEYS AND LOW PRESSURE INTENSIFYING SE OF NEW ENGLAND.
THE GRADIENT WILL SLACKEN THROUGH THE AFTERNOON AND WIND
GUSTS...UP TO 25 TO 30 MPH...WILL DIMINISH. CHILLY TEMPS FRI
MORNING...ESPECIALLY IN COMPARISON TO RECENT DAYS...COUPLED WITH
THE WIND...WILL MAKE IT FEEL AS IF IT WERE IN THE MID 20S TO LOWER
30S. EVEN WITH BRIGHT SUNSHINE...TEMPS ARE NOT EXPECTED TO RISE
QUICKLY AS 850 MB TEMPS WILL START THE DAY JUST BELOW ZERO DEG.
PREVIOUS THINKING HAS NOT CHANGED AND WILL FORECAST HIGHS BELOW 50
DEGREES IN MOST PLACES...WITH MID 40S MOST COMMON. GOOD
RADIATIONAL COOLING IS EXPECTED FRI NIGHT AS HIGH PRESSURE REACHES
THE AREA. CLEAR SKIES AND VIRTUALLY CALM WIND WILL ALLOW EVE TEMPS
TO QUICKLY DROP AS DEWPOINTS DURING THIS TIME WILL BE WELL DOWN IN
THE 20S. OVERNIGHT LOWS ARE EXPECTED TO REACH THE MID AND UPPER
20S WITH SOME LOWER 20S WHERE RADIATIONAL COOLING MAXIMIZES
LONGEST.
CHILLY SURFACE HIGH PRESSURE WILL STILL BE IN PLACE ON SAT...BUT THE
WESTWARD EXTENT OF THE RIDGE WILL BEGIN TO BREAK DOWN DURING THE
AFTERNOON. SOME WEAK RETURN OF MILDER AIR AHEAD OF THE LEADING EDGE
OF THE NEXT COLD SURGE IS EXPECTED BY SAT AFTERNOON. THEREFORE...
THE SECOND HALF OF THE PERIOD SHOULD NOT BE AS CHILLY AND CLOSER TO
VALUES MORE TYPICAL OF MID JAN. WILL FORECAST HIGHS IN THE LOWER TO
MID 50S SAT. DEWPOINTS WILL BE CLIMBING THROUGH THE DAY SAT AND WITH
NIGHTFALL...TEMPS WILL NOT BE ABLE TO FALL AS RAPIDLY OR AS FAR AS
FRI NIGHT. DO NOT SEE A REASON TO STRAY TOO FAR FROM MODEL CONSENSUS
WHICH BRINGS LOWS TO THE MID AND UPPER 30S OVERNIGHT SAT.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 2 PM THURSDAY...THE LONG TERM APPEARS TO BE ENTIRELY RAIN-FREE
AND INCREASINGLY COLD. SUNDAY WILL BE THE ONE MILD DAY AHEAD OF THE
FIRST SHOT OF COLDER AIR SLATED TO ARRIVE LATE IN THE DAY OR AT
NIGHT. THIS FIRST BOUNDARY WILL BE FAIRLY WEAK LEADING TO
TEMPERATURES ONLY A FEW DEGREES SHY OF CLIMO ON MONDAY...EVEN THOUGH
SOME 8 DEGREES COLDER THAN SUNDAY. DEEPENING MID LEVEL TROUGHINESS
AROUND HUDSON BAY VORTEX SENDS MUCH STRONGER SHOT OF COLD AIR
ADVECTION INTO THE SOUTHEAST MONDAY NIGHT. THERE IS STILL SOME
QUESTION AS TO THE ARCTIC CONTENT OF THE AIRMASS THAT FOLLOWS. THE
GFS FOR EXAMPLE HAS 850MB TEMPS RANGING FROM 0 TO -4C SOUTH TO NORTH
ACROSS THE REGION 00Z WED WHEREAS THE ECMWF (FROM 00Z) HAS -6 TO
-12C. THE CANADIAN IS CLOSER IN CAMP TO THE ECWMF IN SHOWING TRUE
ARCTIC AIR INVADING THE SOUTHEAST ALTHOUGH ITS PROGRESS IS SLIGHTLY
HELD UP BY A CLIPPER TYPE OF WAVE THAT MAY OR MAY NOT COME TO PASS.
CURRENT FORECAST WEIGHTED TOWARDS THE COLDER CONSENSUS.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 06Z...PERIODS OF MVFR AND POSSIBLE IFR INTO THE EARLY MORNING
HOURS DUE TO LOWERED CIGS. BY DAYBREAK...VFR WILL PREVAIL AND
CONTINUE THROUGH THE REMAINDER OF THE VALID PERIOD.
MAY SEE SOME LINGERING VCSH OVERNIGHT BUT OVERALL MVFR ARE
ANTICIPATED OVERNIGHT WITH WINDS BECOMING NORTHERLY AT ALL SITES
AOB 15 KTS INTO THE MORNING HOURS. ANY RESIDUAL LOWERED CIGS FROM
OVERNIGHT WILL QUICKLY IMPROVE BY MORNING AS THE COLD FRONT PUSHES
OUT OF THE AREA. VFR WILL PREVAIL FOR THE REMAINDER OF THE PERIOD.
NORTH-NORTHEAST WINDS WILL CONTINUE THROUGHOUT THE DAY WITH GUSTS
UP TO 25 KTS. EXPECT GUSTS TO SUBSIDE INTO THE EARLY EVENING
HOURS.
EXTENDED OUTLOOK...VFR THROUGH THE EXTENDED.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 12:45 AM FRIDAY...GALE FORCE GUSTS PERSIST OVER THE WATERS.
NO CHANGES TO THE FORECAST WITH THE LATEST UPDATE. PREVIOUS
DISCUSSIONS FOLLOWS:
THE ONLY SIGNIFICANT CHANGE TO THE FORECAST WAS TO RAISE SEA
HEIGHTS BY 1-2 FEET BASED ON CURRENTLY REPORTED WAVE OBSERVATIONS
FROM THE FRYING PAN SHOALS BUOY...THE NEARSHORE WRIGHTSVILLE BEACH
BUOY...AND THE OCEAN CREST PIER WAVE GAUGE. WITH THE COLD FRONT
AND ATTENDANT LOW PRESSURE AREA NOW OFFSHORE WINDS WILL BECOME
NORTHERLY OVERNIGHT WITH GALE FORCE GUSTS REMAINING POSSIBLE.
PREVIOUS DISCUSSION FROM 630 PM FOLLOWS...
A COLD FRONT HAS SLID IN FROM THE NORTH AND LIES BETWEEN
WRIGHTSVILLE BEACH AND CAROLINA BEACH ALONG THE NORTH CAROLINA
COASTLINE. NORTHEAST WINDS NORTH OF THE BOUNDARY CONTRAST WITH SOUTH
WINDS ELSEWHERE. ANOTHER PORTION OF THE COLD FRONT IS QUICKLY
OVERTAKING FROM THE WEST...DRIVEN BY STRONG SURFACE LOW PRESSURE NOW
JUST NORTH OF MYRTLE BEACH. THIS LOW AND FRONT WILL SWEEP ACROSS THE
ENTIRE FORECAST AREA IN THE NEXT COUPLE OF HOURS...FOLLOWED BY GUSTY
WESTERLY WINDS THAT SHOULD TURN MORE NORTHERLY WITH TIME OVERNIGHT.
A GALE WARNING REMAINS IN EFFECT MORE FOR GUSTS THAN FOR SUSTAINED
WIND SPEEDS. THE STRONGEST WINDS ARE EXPECTED THIS EVENING WITH
CONVECTIVE SHOWERS ALONG THE FRONT...AND THEN AGAIN AFTER MIDNIGHT
AS THE LOW MOVES OFFSHORE AND COLD AIR POURS INTO THE REGION FROM
THE NORTH. SEAS SHOULD BUILD TO A VERY CHOPPY 4-6 FT WITH 7-FOOT
SEAS POSSIBLE WITHIN 20 MILES OF THE COAST NEAR CAPE FEAR.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 2 PM THURSDAY...THE GALE WILL LIKELY PERSIST INTO THE FIRST
FEW HOURS OF FRI...WITH A PERIOD OF SMALL CRAFT ADVISORY CONDITIONS
EXPECTED THEREAFTER. LOW PRESSURE WILL HAVE MOVED WELL AWAY FROM THE
AREA BY FRI MORNING...INTENSIFYING OFF THE SE NEW ENGLAND COAST. AT
THE SAME TIME...STRONG HIGH PRESSURE WILL BE CENTERED ACROSS THE
OHIO AND TENNESSEE VALLEYS. THE COMBINATION OF THESE TWO FEATURES
WILL CREATE A RATHER TIGHT PRESSURE GRADIENT ACROSS THE WATERS. WIND
SPEEDS WILL BE ON A STEADY DOWNWARD TREND DURING THE DAY ON FRI...
VEERING FROM N TO NE BY FRI EVE AND REMAINING FROM THE NNE OR NE
INTO SAT. WIND SPEEDS WILL CONTINUE TO DIMINISH WITH THE APPROACH OF
THE CENTER OF HIGH PRESSURE. WINDS WILL BECOME MORE WESTERLY SAT
NIGHT AS ANOTHER COLD FRONT APPROACHES FROM THE NW. SEAS WILL BE IN
THE PROCESS OF PEAKING FRI MORNING...IN THE RANGE OF 6 TO 9 FT WITH
PERHAPS 10 FT AT THE FRYING PAN SHOALS BUOY. WAVE HEIGHTS WILL
STEADILY SUBSIDE FRI AFTERNOON AND NIGHT WITH SEAS COMMONLY 2 TO 3
FT SAT AND SAT NIGHT.
LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 2 PM THURSDAY...OFFSHORE/WESTERLY WINDS ON SUNDAY WILL GET
VEERED ABOUT ABOUT A COMPASS POINT TO NW ASSOC WITH THE APPROACH OF
A COLD FRONT. A FURTHER TURN TO THE N LATER AT NIGHT WILL FOLLOW
FROPA BUT ANY INCREASE IN WIND SPEED AND THUS SEAS WILL BE MINIMAL.
THE WHOLE PROCESS IS THEN REPEATED BY THE APPROACH AND PASSAGE OF A
MORE VIGOROUS COLD FRONT MONDAY NIGHT. THIS BOUNDARY AND THE ENSUING
COLD SURGE COULD PUSH WIND AND/OR SEAS UP INTO SCEC REALM OR
POSSIBLY EVEN A SHORT LIVED ADVISORY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...GALE WARNING UNTIL 9 AM EST THIS MORNING FOR AMZ250-252-254-
256.
&&
$$
SYNOPSIS...SHK/REK
NEAR TERM...REK/SHK
SHORT TERM...RJD
LONG TERM...MBB
AVIATION...SGL
MARINE...REK/RJD/MBB
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1136 PM EST THU JAN 17 2013
.SYNOPSIS...
AN INTENSE AND QUICK MOVING AREA OF LOW PRESSURE WILL BRING
WIND...RAIN AND A RETURN TO CHILLY TEMPERATURES TONIGHT. THE
WINTER CHILL WILL PERSIST INTO THE WEEKEND AND THEN PERIODICALLY
BE REINFORCED BY SUCCESSIVE...DRY COLD FRONTS THROUGH MUCH OF
NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1130 PM THURSDAY...BASED ON MULTIPLE REPORTS RELAYED THROUGH
TV METEOROLOGISTS OF SNOW MIXING WITH THE RAIN FARTHER SOUTH THAN
ASOS/AWOS REPORTS HAD INDICATED...I HAVE UPDATED THE FORECAST FOR
THE NEXT 3-5 HOURS TO INCLUDE MIXED PRECIP TYPES AS FAR SOUTH AS
DARLINGTON...DILLON...THE COLUMBUS/BLADEN COUNTY LINE...AND BURGAW.
THE LATEST SEVERAL RUC MODEL RUNS SHOW FREEZING LEVELS SHOULD BE
FALLING BELOW 2000 FT AGL SHORTLY IN THE BENNETTSVILLE AND LUMBERTON
AREAS WHICH MAY SUPPORT MORE SNOW MAKING IT TO THE SURFACE. MY
THOUGHTS STILL HAVE NOT CHANGED WITH RESPECT TO THE VERY LOW
LIKELIHOOD OF ANY ACCUMULATIONS REGARDLESS OF HOW MUCH SNOW MIXES
IN. PREVIOUS DISCUSSION FROM 1000 PM FOLLOWS...
THE COLD FRONT IS NOW WELL OFFSHORE. THE BAND OF HEAVY RAINFALL AND
EMBEDDED CONVECTION WITHIN THE ENHANCED ZONE OF ASCENT IS OFFSHORE
TOO. ATTENTION NOW TURNS TO THE UPPER LEVEL LOW CURRENTLY OVER
UPSTATE SOUTH CAROLINA. THIS SWIRLING BALL OF COLD AIR ALOFT IS
FORECAST BY ALL MODEL GUIDANCE TO MOVE NORTHEASTWARD TO THE SOUTHERN
CHESAPEAKE BAY BY 3-5 AM. STEEP LAPSE RATES ALOFT AND DEEP MOISTURE
ASSOCIATED WITH THIS LOW ARE PRODUCING WIDESPREAD LIGHT
PRECIPITATION EXTENDING FROM UPSTATE SOUTH CAROLINA ACROSS THE
WESTERN TWO-THIRDS OF NORTH CAROLINA. UNDERNEATH THIS UPPER
SYSTEM...COLD AIR BEING PULLED SOUTH BEHIND THE DEPARTING SURFACE
LOW HAS CHANGED RAIN OVER TO SNOW ALONG AND NORTH OF A LINE FROM
JUST NORTH OF CHARLOTTE TO ASHEBORO TO RALEIGH. WHILE THE CHANCES
FOR MEASURABLE SNOW HAVE NEVER BEEN GOOD IN OUR FORECAST
AREA...THERE REMAINS A SMALL POTENTIAL THAT THE RAIN COULD END MIXED
WITH SNOW ACROSS BENNETTSVILLE...LUMBERTON AND ELIZABETHTOWN AFTER
MIDNIGHT. NO ACCUMULATIONS ARE EXPECTED DUE TO ABOVE-FREEZING AIR
TEMPERATURES AND WELL-ABOVE FREEZING GROUND TEMPERATURES.
ALSO...I SPOKE TO A REPRESENTATIVE WITH THE EMERGENCY MANAGEMENT
AGENCY IN COLUMBUS COUNTY WHO REPORTED FAIRLY WIDESPREAD AND
SUBSTANTIAL DAMAGE FROM THE LINE OF SHOWERS THAT MOVED THROUGH THERE
AROUND 645 PM. WE WILL BE SENDING A STORM SURVEY TEAM OUT TO THE
CHADBOURN COMMUNITY IN WESTERN COLUMBUS COUNTY TOMORROW MORNING TO
SURVEY AND CLASSIFY THE DAMAGE THERE.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 2 PM THURSDAY...WINTER IS BACK. IT WILL BE A CHILLY AND
BRISK START TO THE DAY FRI AS THE PRESSURE GRADIENT WILL REMAIN
RATHER TIGHT BETWEEN STRONG HIGH PRESSURE ACROSS THE OHIO AND
TENNESSEE VALLEYS AND LOW PRESSURE INTENSIFYING SE OF NEW ENGLAND.
THE GRADIENT WILL SLACKEN THROUGH THE AFTERNOON AND WIND
GUSTS...UP TO 25 TO 30 MPH...WILL DIMINISH. CHILLY TEMPS FRI
MORNING...ESPECIALLY IN COMPARISON TO RECENT DAYS...COUPLED WITH
THE WIND...WILL MAKE IT FEEL AS IF IT WERE IN THE MID 20S TO LOWER
30S. EVEN WITH BRIGHT SUNSHINE...TEMPS ARE NOT EXPECTED TO RISE
QUICKLY AS 850 MB TEMPS WILL START THE DAY JUST BELOW ZERO DEG.
PREVIOUS THINKING HAS NOT CHANGED AND WILL FORECAST HIGHS BELOW 50
DEGREES IN MOST PLACES...WITH MID 40S MOST COMMON. GOOD
RADIATIONAL COOLING IS EXPECTED FRI NIGHT AS HIGH PRESSURE REACHES
THE AREA. CLEAR SKIES AND VIRTUALLY CALM WIND WILL ALLOW EVE TEMPS
TO QUICKLY DROP AS DEWPOINTS DURING THIS TIME WILL BE WELL DOWN IN
THE 20S. OVERNIGHT LOWS ARE EXPECTED TO REACH THE MID AND UPPER
20S WITH SOME LOWER 20S WHERE RADIATIONAL COOLING MAXIMIZES
LONGEST.
CHILLY SURFACE HIGH PRESSURE WILL STILL BE IN PLACE ON SAT...BUT THE
WESTWARD EXTENT OF THE RIDGE WILL BEGIN TO BREAK DOWN DURING THE
AFTERNOON. SOME WEAK RETURN OF MILDER AIR AHEAD OF THE LEADING EDGE
OF THE NEXT COLD SURGE IS EXPECTED BY SAT AFTERNOON. THEREFORE...
THE SECOND HALF OF THE PERIOD SHOULD NOT BE AS CHILLY AND CLOSER TO
VALUES MORE TYPICAL OF MID JAN. WILL FORECAST HIGHS IN THE LOWER TO
MID 50S SAT. DEWPOINTS WILL BE CLIMBING THROUGH THE DAY SAT AND WITH
NIGHTFALL...TEMPS WILL NOT BE ABLE TO FALL AS RAPIDLY OR AS FAR AS
FRI NIGHT. DO NOT SEE A REASON TO STRAY TOO FAR FROM MODEL CONSENSUS
WHICH BRINGS LOWS TO THE MID AND UPPER 30S OVERNIGHT SAT.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 2 PM THURSDAY...THE LONG TERM APPEARS TO BE ENTIRELY RAIN-FREE
AND INCREASINGLY COLD. SUNDAY WILL BE THE ONE MILD DAY AHEAD OF THE
FIRST SHOT OF COLDER AIR SLATED TO ARRIVE LATE IN THE DAY OR AT
NIGHT. THIS FIRST BOUNDARY WILL BE FAIRLY WEAK LEADING TO
TEMPERATURES ONLY A FEW DEGREES SHY OF CLIMO ON MONDAY...EVEN THOUGH
SOME 8 DEGREES COLDER THAN SUNDAY. DEEPENING MID LEVEL TROUGHINESS
AROUND HUDSON BAY VORTEX SENDS MUCH STRONGER SHOT OF COLD AIR
ADVECTION INTO THE SOUTHEAST MONDAY NIGHT. THERE IS STILL SOME
QUESTION AS TO THE ARCTIC CONTENT OF THE AIRMASS THAT FOLLOWS. THE
GFS FOR EXAMPLE HAS 850MB TEMPS RANGING FROM 0 TO -4C SOUTH TO NORTH
ACROSS THE REGION 00Z WED WHEREAS THE ECMWF (FROM 00Z) HAS -6 TO
-12C. THE CANADIAN IS CLOSER IN CAMP TO THE ECWMF IN SHOWING TRUE
ARCTIC AIR INVADING THE SOUTHEAST ALTHOUGH ITS PROGRESS IS SLIGHTLY
HELD UP BY A CLIPPER TYPE OF WAVE THAT MAY OR MAY NOT COME TO PASS.
CURRENT FORECAST WEIGHTED TOWARDS THE COLDER CONSENSUS.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
AS OF 00Z...PERIODS OF MVFR AND IFR WILL CONTINUE OVERNIGHT INTO THE
EARLY MORNING HOURS DUE TO REDUCED VISIBILITIES REGARDING PATCHY FOG
AND HEAVIER DOWNPOURS EARLY ON...FOLLOWED BY LOWERED CIGS. AFTER
DAYBREAK...VFR WILL PREVAIL AND CONTINUE THROUGH THE REMAINDER OF
THE VALID PERIOD.
CURRENT RADAR DEPICTS RAINFALL ACROSS THE ENTIRE AREA WITH QUITE THE
SCENARIO WITH A N-S WIND-DRIVEN LINE OF STORMS IN ASSOCIATION WITH A
LOW PRESSURE SYSTEM JUST ALONG THE COLD FRONT. AS A RESULT THERE ARE
A VARIETY OF WIND DIRECTIONS ACROSS THE AREA WITH WESTERLY WINDS AT
KFLO/KMYR/KCRE...AND EAST-NORTHEASTERLY WINDS AT KLBT/KILM. AS THIS
LINE CONTINUES TO PROPAGATE EAST NORTH-EAST AND TAPER OFF OVER THE
NEXT FEW HOURS...ALL WINDS WILL BECOME WESTERLY AOB 15 KTS WITH
GUSTS UP TO 25 KTS OVERNIGHT. AFTER MIDNIGHT...WIND DIRECTION WILL
CONTINUE TO VEER...BECOMING NORTHERLY AOB 15 KTS GUSTS 18-25 KTS
INTO THE MORNING HOURS. ANY RESIDUAL LOWERED CIGS FROM OVERNIGHT
WILL QUICKLY IMPROVE BY MORNING AS THE COLD FRONT PUSHES OUT OF THE
AREA. VFR WILL PREVAIL FOR THE REMAINDER OF THE PERIOD.
NORTH-NORTHEAST WINDS WILL CONTINUE THROUGHOUT THE DAY ON
FRIDAY...WITH GUSTS SUBSIDING INTO THE EARLY EVENING HOURS.
EXTENDED OUTLOOK...VFR THROUGH THE EXTENDED.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1000 PM THURSDAY...THE ONLY SIGNIFICANT CHANGE TO THE FORECAST
WAS TO RAISE SEA HEIGHTS BY 1-2 FEET BASED ON CURRENTLY REPORTED
WAVE OBSERVATIONS FROM THE FRYING PAN SHOALS BUOY...THE NEARSHORE
WRIGHTSVILLE BEACH BUOY...AND THE OCEAN CREST PIER WAVE GAUGE. WITH
THE COLD FRONT AND ATTENDANT LOW PRESSURE AREA NOW OFFSHORE WINDS
WILL BECOME NORTHERLY OVERNIGHT WITH GALE FORCE GUSTS REMAINING
POSSIBLE. PREVIOUS DISCUSSION FROM 630 PM FOLLOWS...
A COLD FRONT HAS SLID IN FROM THE NORTH AND LIES BETWEEN
WRIGHTSVILLE BEACH AND CAROLINA BEACH ALONG THE NORTH CAROLINA
COASTLINE. NORTHEAST WINDS NORTH OF THE BOUNDARY CONTRAST WITH SOUTH
WINDS ELSEWHERE. ANOTHER PORTION OF THE COLD FRONT IS QUICKLY
OVERTAKING FROM THE WEST...DRIVEN BY STRONG SURFACE LOW PRESSURE NOW
JUST NORTH OF MYRTLE BEACH. THIS LOW AND FRONT WILL SWEEP ACROSS THE
ENTIRE FORECAST AREA IN THE NEXT COUPLE OF HOURS...FOLLOWED BY GUSTY
WESTERLY WINDS THAT SHOULD TURN MORE NORTHERLY WITH TIME OVERNIGHT.
A GALE WARNING REMAINS IN EFFECT MORE FOR GUSTS THAN FOR SUSTAINED
WIND SPEEDS. THE STRONGEST WINDS ARE EXPECTED THIS EVENING WITH
CONVECTIVE SHOWERS ALONG THE FRONT...AND THEN AGAIN AFTER MIDNIGHT
AS THE LOW MOVES OFFSHORE AND COLD AIR POURS INTO THE REGION FROM
THE NORTH. SEAS SHOULD BUILD TO A VERY CHOPPY 4-6 FT WITH 7-FOOT
SEAS POSSIBLE WITHIN 20 MILES OF THE COAST NEAR CAPE FEAR.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 2 PM THURSDAY...THE GALE WILL LIKELY PERSIST INTO THE FIRST
FEW HOURS OF FRI...WITH A PERIOD OF SMALL CRAFT ADVISORY CONDITIONS
EXPECTED THEREAFTER. LOW PRESSURE WILL HAVE MOVED WELL AWAY FROM THE
AREA BY FRI MORNING...INTENSIFYING OFF THE SE NEW ENGLAND COAST. AT
THE SAME TIME...STRONG HIGH PRESSURE WILL BE CENTERED ACROSS THE
OHIO AND TENNESSEE VALLEYS. THE COMBINATION OF THESE TWO FEATURES
WILL CREATE A RATHER TIGHT PRESSURE GRADIENT ACROSS THE WATERS. WIND
SPEEDS WILL BE ON A STEADY DOWNWARD TREND DURING THE DAY ON FRI...
VEERING FROM N TO NE BY FRI EVE AND REMAINING FROM THE NNE OR NE
INTO SAT. WIND SPEEDS WILL CONTINUE TO DIMINISH WITH THE APPROACH OF
THE CENTER OF HIGH PRESSURE. WINDS WILL BECOME MORE WESTERLY SAT
NIGHT AS ANOTHER COLD FRONT APPROACHES FROM THE NW. SEAS WILL BE IN
THE PROCESS OF PEAKING FRI MORNING...IN THE RANGE OF 6 TO 9 FT WITH
PERHAPS 10 FT AT THE FRYING PAN SHOALS BUOY. WAVE HEIGHTS WILL
STEADILY SUBSIDE FRI AFTERNOON AND NIGHT WITH SEAS COMMONLY 2 TO 3
FT SAT AND SAT NIGHT.
LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 2 PM THURSDAY...OFFSHORE/WESTERLY WINDS ON SUNDAY WILL GET
VEERED ABOUT ABOUT A COMPASS POINT TO NW ASSOC WITH THE APPROACH OF
A COLD FRONT. A FURTHER TURN TO THE N LATER AT NIGHT WILL FOLLOW
FROPA BUT ANY INCREASE IN WIND SPEED AND THUS SEAS WILL BE MINIMAL.
THE WHOLE PROCESS IS THEN REPEATED BY THE APPROACH AND PASSAGE OF A
MORE VIGOROUS COLD FRONT MONDAY NIGHT. THIS BOUNDARY AND THE ENSUING
COLD SURGE COULD PUSH WIND AND/OR SEAS UP INTO SCEC REALM OR
POSSIBLY EVEN A SHORT LIVED ADVISORY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...GALE WARNING UNTIL 9 AM EST FRIDAY FOR AMZ250-252-254-256.
&&
$$
NEAR TERM...TRA
SHORT TERM...RJD
LONG TERM...MBB
AVIATION...SGL
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1030 PM CST THU JAN 17 2013
.DISCUSSION.../ISSUED AT 845 PM CST/
THE WARM FRONT IS PRESENTLY SITUATED THROUGH OUR SOUTH CENTRAL SOUTH
DAKOTA ZONES LATE THIS EVENING. AS EXPECTED MID CLOUDS ALSO
STREAMING OVERHEAD...WITH BROKEN STRATUS COVERING A GOOD BIT OF OUR
NORTH AND EAST EARLIER IN THE EVENING NOW MOSTLY DISSIPATING EXCEPT
FOR SOME AREAS OF NORTHWESTERN IOWA. ALL MODELS ARE OVERDOING THE
EXTENT OF STRATUS THIS EVENING...BUT ALL POINT TOWARD ANY EXISTING
LOW CLOUDS PULLING OFF TO THE NORTHEAST OVERNIGHT AS THE LOW LEVEL
FLOW TURNS SOUTH/SOUTHWESTERLY. OBS INDICATING SOME FOG DEVELOPING
JUST TO OUR SOUTH...THROUGH EASTERN NEBRASKA...WITH A FEW LOWERING
VISIBILITIES OVER NORTHWESTERN IOWA ALSO...SO PATCHY FOG REMAINS
APPROPRIATE IN THE FORECAST FOR PARTS OF THE AREA TONIGHT.
TEMPERATURES ARE ON TRACK FOR LOWS MAINLY IN THE 20S...POSSIBLY
RISING A BIT LATER IN THE NIGHT AS WINDS PICK UP AND CLOUDS CONTINUE
TO STREAM ACROSS THE REGION. GOING FORECAST COVERS THE ABOVE
MENTIONED ELEMENTS PRETTY WELL...WITH ONLY MINOR UPDATES FOR REAL
TIME TRENDS.
&&
.AVIATION.../FOR THE 06Z TAF ISSUANCE/
OCCASIONAL IFR CEILINGS AND VISIBILITIES WILL OCCUR EAST OF I29
THROUGH 12Z FRIDAY AND THEN VFR 12Z THROUGH 06Z. WEST OF I29...VFR
CONDITIONS CAN BE EXPECTED THROUGH 06Z SATURDAY.
&&
.PREV DISCUSSION.../ISSUED AT 311 PM CST/
WARM FRONT LIFTS NORTH TONIGHT GIVING WAY TO A MILD AND MOSTLY SUNNY
FRIDAY ACROSS THE AREA. FORECAST TONIGHT A BIT TRICKY WITH POTENTIAL
STRATUS ISSUES. MID LEVEL CLOUDS WILL CONTINUE TO STREAM ACROSS OUR
NORTH THROUGH THE NIGHT ASSOCIATED WITH MID LEVEL FRONTAL BOUNDARY.
HOWEVER THINK THE CWA WILL REMAIN DRY...OTHER THAN MAYBE AN ISOLATED
FLURRY ACROSS SOUTHWEST MINNESOTA. AREA OF STRATUS FROM SOUTH OF
SIOUX FALLS INTO EASTERN NEBRASKA CONTINUES TO DISSIPATE UNDER
DAYTIME HEATING. HOWEVER...CURRENT THINKING...BACKED BY THE RAP AND
NAM...IS THAT THIS AREA WILL REFORM AND EXPAND THIS EVENING INTO
TONIGHT. WITH SOUTHERLY BOUNDARY LAYER FLOW THIS WILL THEN EXPAND
AND COULD COVER MUCH OF THE CWA FOR A PERIOD TONIGHT. DRIER BOUNDARY
LAYER MOVING IN FROM THE SOUTHWEST WILL ALLOW THE STRATUS TO CLEAR
FROM SOUTHWEST TO NORTHEAST THROUGH THE NIGHT. COULD BE AREAS OF FOG
AS WELL. BEST CHANCE OF STAYING CLEAR THROUGH THE NIGHT WILL BE WEST
OF SIOUX CITY TO YANKTON UP TOWARDS GREGORY. LOW LEVEL JET INCREASES
TONIGHT...WHICH SHOULD KEEP A SOUTHERLY BREEZE GOING. THE BREEZE
COMBINED WITH POTENTIAL CLOUDS SHOULD KEEP LOWS ON THE WARM SIDE OF
GUIDANCE. GENERALLY AROUND 20 SOUTHWEST MINNESOTA TO LOW AND MID 20S
ELSEWHERE. LOWS WILL PROBABLY BE IN THE EVENING...WITH STEADY OR
RISING TEMPERATURES OVERNIGHT.
ANY STRATUS SHOULD EXIT THE CWA BY AROUND 12Z. COULD BE SOME CIRRUS
OVERHEAD DURING THE DAY...BUT OVERALL EXPECTING A MOSTLY SUNNY DAY.
KEPT HIGHS CLOSE TO THE ECMWF AND ECMWF MOS...AS THEY PERFORMED BEST
ON WEDNESDAY. LOOKING AT LOW AND MID 40S NORTH TO THE LOW AND MID
50S CLOSER TO THE MISSOURI RIVER. WITH 925MB TEMPERATURES
APPROACHING 10C IN OUR SOUTHWEST...WOULD NOT BE SURPRISED IF
SOMEPLACE IN NORTH CENTRAL NEBRASKA...OR ADJACENT AREAS OF GREGORY
AND CHARLES MIX COUNTIES COME CLOSE TO 60. /CHENARD
MAJOR PATTERN CHANGE EXPECTED TO BEGIN ON SATURDAY AS AN ARCTIC
BLAST DROPS SOUTHWARD INTO THE NORTHERN PLAINS. COLD FRONT SLATED TO
PUSH THROUGH THE FORECAST AREA DURING THE DAY...AND THE BIG QUESTION
IS HOW QUICKLY IT WILL ARRIVE. LARGE TEMPERATURE DISCREPANCIES
BETWEEN MODELS FOR SATURDAY HIGHS WITH A STAGGERING NEARLY 30 DEGREE
DIFFERENCE BETWEEN THE WARMEST AND COLDEST MODELS IN SIOUX FALLS.
THE GFS AND NAM ARE THE FASTEST WITH PULLING THE COLDER AIR INTO THE
FORECAST AREA WHILE THE ECMWF AND GEM PAINT A MUCH SLOWER
PROGRESSION AND DEPICT A MILD DAY ACROSS THE CWA. HAVE OPTED FOR A
MIDDLE GROUND SOLUTION WITH MIXING KEEPING TEMPERATURES ON THE
MILDER SIDE. EXPECT THE MISSOURI VALLEY TO REACH NEAR 40 RANGING TO
AROUND 30 AT OUR NORTHERN BORDER.
FRONTAL PASSAGE IS EXPECTED TO BE DRY...BUT STRONG NORTHWEST WINDS
IN ITS WAKE WILL PRODUCE SOME BRUTAL WIND CHILLS. WITH 925MB WINDS
UP AROUND 50 KT AND STRONG COLD AIR ADVECTION...WOULD NOT BE
SURPRISED TO SEE ADVISORY LEVEL WINDS. COLD AIR WILL QUICKLY DROP
SOUTH LATE EVENING INTO THE OVERNIGHT AND LOWS SATURDAY NIGHT WILL
BE IN THE SINGLE DIGITS ABOVE AND BELOW ZERO. WINDS WILL DECREASE ON
SUNDAY AS SURFACE HIGH PRESSURE QUICKLY SHUNTS SOUTHEAST OF THE
REGION...BUT DO NOT EXPECT MUCH RECOVERY OF TEMPERATURES. HIGHS WILL
ONLY BE IN THE SINGLE DIGITS AND TEENS FOR THE MAJORITY OF THE CWA.
A QUICK SHOT OF LIGHT SNOW WILL MOVE SOUTHEAST DURING THE DAY AHEAD
OF A REINFORCING SHOT OF COLD AIR. SNOW WOULD LIKELY BE BRIEF WITH
NOT MUCH MOISTURE TO WORK WITH...HOWEVER THE COLD TEMPERATURES
SHOULD PRODUCE UP TO AN INCH OF FLUFFY SNOW. NORTHERLY WINDS WILL
PICK UP ONCE AGAIN BEHIND THE FRONT AND WOULD DRIFT WHATEVER SNOW
FALLS ON SUNDAY. SUNDAY NIGHT WILL SEE SOME OF THE COLDEST
TEMPERATURES OF THE SEASON SO FAR WITH THE NORTHERN HALF DROPPING
INTO THE TEENS BELOW ZERO. FRIGID TEMPERATURES WILL CONTINUE INTO
MONDAY WITH HIGHS NEAR ZERO IN OUR NORTHEAST.
MODELS KEEP THE LARGE UPPER RIDGE OVER THE INTERMOUNTAIN WEST IN
PLACE INTO TUESDAY...WHICH LEAVES THE FORECAST AREA UNDER COOL
NORTHWEST FLOW. MODELS BRING A WEAK WAVE THROUGH THE FLOW AROUND THE
MONDAY NIGHT TO TUESDAY TIME FRAME...HOWEVER NOT A LOT OF CONFIDENCE
THAT THE CWA WILL SEE MUCH IMPACT. WILL LEAVE THE SLIGHT CHANCES
THAT THE LATEST ALLBLEND PRODUCED FOR NOW. WARMER WEATHER MAY RETURN
ON WEDNESDAY AND THURSDAY WITH THE RIDGE ADVANCING EASTWARD.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
314 AM CST FRI JAN 18 2013
.SHORT TERM...TODAY THROUGH SUNDAY NIGHT
314 AM CST FRI JAN 18 2013
THE MAIN FOCUS THROUGH THE WEEKEND IS WITH PRECIPITATION CHANCES
ALONG WITH THE TEMPERATURE DROP AND STRONG WINDS BEHIND THE FIRST
IN A SERIES OF COLD FRONTS THAT WILL MOVE THROUGH THE REGION.
CURRENTLY...A BAND OF SNOW EXTENDS FROM CENTRAL MINNESOTA DOWN
INTO SOUTHWEST WISCONSIN AHEAD OF A SURFACE WARM FRONT AND WILL
QUICKLY PROPAGATE TO THE EAST THIS MORNING. SOME OF THIS SNOW HAS
TAKEN ON A CONVECTIVE LOOK TO IT ACROSS CENTRAL MINNESOTA...LIKELY
DUE TO THE LOW LEVEL FRONTOGENESIS BEING SHOWN THERE ON 18.06Z RAP
CROSS SECTIONS...WITH SOME VISIBILITIES DROPPING DOWN TO A MILE AT
TIMES. THIS SNOW WILL BE OUT OF THE FORECAST AREA QUICKLY THIS
MORNING WITH SNOW TOTALS STILL LOOKS TO BE AROUND AN INCH OR TWO
IN NORTH CENTRAL WISCONSIN WITH LESS THAN AN INCH SOUTH OF CLARK
COUNTY WISCONSIN. CONFIDENCE NOT VERY HIGH THAT FREEZING DRIZZLE
WILL OCCUR AS THERE HAS BEEN LITTLE IN REPORTS OF IT ALONG THE
BACK EDGE OF THE SNOW. 18.06Z RAP SOUNDINGS SHOW THAT IF THERE IS
AN AREA WHERE THE FREEZING DRIZZLE IS POSSIBLE...IT MAY BE ACROSS
NORTH CENTRAL WISCONSIN WHERE THE COLUMN MAY LOSE ICE WITH LOW
LEVEL LIFT STILL STRONG. CEILINGS HAVE NOT BEEN VERY LOW
THOUGH...MAINLY ABOVE 2KFT...SO THINK THAT THE LOW LEVEL RH MAY BE
A LITTLE OVERDONE. WILL LEAVE THE FZDZ MENTION IN THE FORECAST FOR
NOW...BUT HAVE TRIMMED IT BACK TO JUST BEING POSSIBLE IN WEST
CENTRAL WISCONSIN...MAINLY ALONG AND NORTH OF I-94.
THE NEXT QUESTION IS WITH TEMPERATURES TODAY WITH MUCH OF THE
REGION BEING IN THE WARM SECTOR AS A WARM FRONT LIFTS NORTHEAST OF
THE REGION. THOUGH 850MB TEMPERATURES ARE ONLY AROUND 1 STANDARD
DEVIATION ABOVE THE NORM...HIGHS MAY COME CLOSE TO A RECORD AT
RST WHERE THE PREVIOUS RECORD IS 46. WITH JUST MID TO UPPER LEVEL
CLOUD COVER TO CONTEND WITH...AND LITTLE TO NO SNOW ON THE
GROUND...TEMPERATURES SHOULD CLIMB INTO THE 40S ACROSS MUCH OF THE
REGION. THE ECMWF HAS BEEN OUR BEST VERIFYING GUIDANCE WITH THE
RECENT WARM DAYS...SO HAVE FOLLOWED IT WITH THE TRENDS FOR TODAY.
THE HAMMER DROPS SATURDAY AS THE FIRST COLD FRONT COMES THROUGH IN
THE AFTERNOON WITH A SECONDARY ONE COMING THROUGH IN THE EVENING
THAT WILL BRING DOWN THE MUCH COLDER AIR AND STRONG/GUSTY WINDS.
THE STRONG COLD AIR ADVECTION AND TIGHT PRESSURE GRADIENT WILL
LEAD TO WIND GUSTS UP INTO THE 40MPH RANGE SATURDAY EVENING RIGHT
AFTER FROPA. THIS COMBINATION OF DROPPING TEMPERATURES AND GUSTY
WINDS COULD LEAD TO THE WIND CHILL DROPPING INTO THE -20F TO -25F
RANGE ACROSS SOUTHEAST MINNESOTA AND WESTERN WISCONSIN TO WHERE A
WIND CHILL ADVISORY MAY BE NEEDED. BUMPED UP CLOUD COVER A BIT
AND ADDED SOME FLURRIES BEHIND THE COLD FRONT AS 18.00Z NAM/GFS
SOUNDINGS SHOW SOME LOW LEVEL RH DROPPING INTO THE -10C TO -20C
RANGE.
ANOTHER WEAKLY FORCED SYSTEM WILL MOVE THROUGH IOWA ON SUNDAY AND
BRING ANOTHER POSSIBLE ROUND OF LIGHT SNOW ALONG WITH IT. WITH A
RIDGE OF HIGH PRESSURE PUSHING DOWN FROM THE NORTHWEST THOUGH...IT
WILL BE HARD TO SQUEEZE OUT MUCH IN THE WAY OF PRECIPITATION.
.LONG TERM...MONDAY THROUGH THURSDAY
314 AM CST FRI JAN 18 2013
THE MAIN FOCUS INTO NEXT WEEK IS WITH THE TEMPERATURES AND HOW LOW
THEY WILL GO. THE LACK OF SNOW ON THE GROUND WILL HELP TO KEEP
TEMPERATURES UP ABOUT 10 DEGREES FROM WHERE THEY NORMALLY COULD
DROP TO...BUT EVEN SO LOWS WILL DROP WELL BELOW ZERO MONDAY
MORNING AND TUESDAY MORNING. THE 18.00Z GEM IS THE COLDEST OF THE
MODEL RUNS WITH HAVING 850MB TEMPERATURES DROPPING DOWN TO -32C BY
MONDAY AFTERNOON...BUT THAT APPEARS TO BE A BIT EXTREME COMPARED
TO THE 18.00Z GFS/ECMWF WHICH HAVE 850MB TEMPERATURES AROUND -24C
AT THAT SAME TIME. WIND CHILL ADVISORIES WILL LIKELY BE NEEDED
MONDAY AND TUESDAY WITH WIND CHILLS DROPPING DOWN INTO THE -20F TO
-30F RANGE. THE SURFACE RIDGE AXIS PASSES BY ON WEDNESDAY MORNING
WITH WARMER LOW LEVEL AIR MOVING BACK IN THROUGH THE REST OF THE
WEEK. THE 18.00Z GFS/ECMWF CONTINUE TO HINT AT A LATE WEEK SYSTEM
MOVING THROUGH THE REGION...BUT THERE IS CONSIDERABLE SPREAD ON
WHERE THIS SYSTEM WILL TRACK.
&&
.AVIATION...THROUGH 06Z SATURDAY
1128 PM CST THU JAN 17 2013
A BAND OF SNOW NOW OVER NORTH DAKOTA IS EXPECTED TO MOVE/EXPAND
SOUTHEASTWARD OVERNIGHT IN ZONE OF WARM ADVECTION AHEAD OF A WEAK
SHORTWAVE. MODELS CONSISTENT WITH THE TAF SITES BEING ON THE
SOUTHWESTERN EDGE OF THE PRECIPITATION SHIELD...ESPECIALLY KRST.
EXPECT LOWER LAYERS TO SATURATE THROUGH 09Z WITH IFR TO MVFR
CEILINGS DEVELOPING AS THE SNOW MOVES IN AROUND 09Z. FEEL KLSE
STILL HAS A BETTER CHANCE AT MEASURABLE SNOW SO DID CONTINUE THE
IFR VISIBILITIES FOR A FEW HOURS...WHILE ADDRESSED THIS AS A TEMPO
GROUP AT KRST. STILL SOME CONCERN FOR A LITTLE FREEZING DRIZZLE ON
THE BACK SIDE OF THE PRECIPITATION SHIELD AS BUFKIT SOUNDINGS
CONTINUE TO SHOW A LOSS OF ICE, HOWEVER...AM CONCERNED THAT
PRECIPITATION MAY BE ENDED BY THE TIME THERE IS A LOSS OF ICE.
THUS DID NOT INCLUDE IN THE TAFS. OTHERWISE...IMPROVING CONDITIONS
EXPECTED THROUGH THE MORNING HOURS WITH CEILINGS RISING AND CLOUDS
SCATTERING OUT DURING THE AFTERNOON. STRONG SOUTHWEST WINDS WILL
GUST TO 26 KNOTS AT KRST DURING THE AFTERNOON.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
314 AM CST FRI JAN 18 2013
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...RABERDING
AREA FORECAST DISCUSSION...UPDATED
NWS MARQUETTE MI
1027 AM EST FRI JAN 18 2013
.UPDATE...
ISSUED AT 1023 AM EST FRI JAN 18 2013
WARM AIR ADVECTION EVIDENT UPSTREAM ON SOUTHERN FRINGE OF UPPER
TROUGH OVER HUDSON BAY/NORTHERN QUEBEC. WARM AIR ADVECTION AND H8-H6
FRONTOGENESIS IN ENTRANCE REGION OF JET STREAK OVER ONTARIO AFFECTS
THE AREA WITH WIDESPREAD SNOW TODAY. H8-H7 FRONTOGENESIS EXPECTED TO
EXPAND EAST ACROSS SOUTHERN TIER THIS MORNING AND ACROSS LK MICHIGAN
ZONES THIS AFTN AND INTO EVENING. 12Z NAM IS CONSISTENT WITH 06Z RUN
AND MATCHES WELL WITH RUC/LOCAL-WRF AND MOST IMPORTANTLY REALITY
BASED ON RADAR/SFC OBS. EXPECT INCREASING SNOW OVER SCNTRL AND
SOUTHEAST CWA THROUGH AFTN...CUTTING OUT FIRST ALONG WI BORDER.
BASED ON LOCAL WRF AND RUC QPF AMOUNTS ALONG WITH EXPECTED SNOW
RATIOS SOMEWHERE IN 10-17:1 RANGE...EXPECT ADVY SNOW AMOUNTS UP TO 5
INCHES OVR PORTIONS OF SCNTRL AND SOUTHEAST/EAST ZONES FOR THIS
EVENT. SOUTHWEST FLOW OFF LK MICHIGAN WITH TEMPS AT INVERSION TOP
AROUND -10C LEADING TO SUFFICIENT OVER-WATER INSTABILITY ALSO COULD
RESULT IN ADDITIONAL INCH OR TWO DUE TO LAKE ENHANCEMENT.
SO...COORD WITH APX AND ISSUED WINTER WEATHER ADVY INTO THE EVENING
FOR DELTA THROUGH LUCE COUNTIES. FARTHER WEST...THERE IS POTENTIAL
FOR ENHANCED BAND OF SNOW TO PUSH TOTALS PAST 3 INCHES...BUT SINCE
HEAVIER SNOW FROM GOGEBIC THROUGH MENOMINEE ONLY LASTS INTO MID AFTN
AND WILL BE PRETTY LOCALIZED...PLAN NOT ISSUE ADVY THERE AND CONTINUE
TO ADDRESS VIA SPECIAL WEATHER STATEMENTS. THAT COULD CHANGE BASED ON
REPORTS THOUGH. BASED ON SOUNDINGS WHEN SNOW CUTS OUT THIS AFTN...SHOULD
SEE TRANSITION TO LGT SNOW AND/OR FREEZING DRIZZLE. &&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 435 AM EST FRI JAN 18 2013
SATELLITE AND RADAR ARE SHOWING THE LAKE EFFECT STILL ONGOING
OVER THE KEWEENAW AND FOR LOCATIONS EAST OF MUNISING. WITH WINDS
CONTINUING TO BACK TO THE WEST AND THEN SOUTHWEST EARLY THIS
MORNING...EXPECT THE LAKE EFFECT TO FOLLOW SUIT AND DEPART THE
EASTERN CWA THIS MORNING. WITH THE INTENSITY OF THE SNOW
DIMINISHING AND A STEADY MOVEMENT EASTWARD...WILL LET THE
ADVISORY EXPIRE AT 12Z. ELSEWHERE...THE HIGH PRESSURE RIDGE OVER
THE CWA AT THIS TIME HAS LED TO A PERIOD OF CLEAR SKIES OVER THE
CENTRAL CWA FOR A PERIOD THIS MORNING...ALLOWING SOME LOCATIONS TO
DROP INTO THE SINGLE DIGITS BELOW ZERO. MID AND HIGH CLOUDS HAVE
STOPPED THE TEMP DROP ALONG THE WISCONSIN BORDER AS THEY MOVE OVER
THE CWA AHEAD OF THE MAIN WEATHER MAKER FOR TODAY.
THE AREA OF LOW PRESSURE IS CURRENTLY IN SOUTHERN
SASKATCHEWAN...BUT AN SURFACE TROUGH STRETCHING SOUTHEAST THROUGH
THE DAKOTAS AND ASSOCIATED H850 TROUGH TO THE NORTHEAST OF THAT HAS
LED TO LIGHT SNOW UNDER THE BROAD WARM AIR ADVECTION THIS MORNING
IN MN AND WESTERN WI. THE LOW IS EXPECTED TO DROP SOUTHEAST THROUGH
NORTHERN MN TODAY AND INTO NORTHERN WISCONSIN OR SOUTHERN UPPER
MICHIGAN BY 00Z SATURDAY. WITH THE RIGHT REAR OF THE UPPER JET
MOVING OVER UPPER MICHIGAN AND THE SHORTWAVE MOVING THROUGH THIS
AFTERNOON AND EARLY EVENING...EXPECT THE LOW TO INTENSIFY SOME. THE
MAIN FOCUS FOR THE SNOW WILL BE THE STRONG H850-700 AND H700-500
WARM AIR ADVECTION AND ASSOCIATED FGEN ON THE H850-600 LAYER. THE
H700-500 WAA MOVES DIRECTLY ACROSS THE CWA AND THAT WILL LEAD THE
BROAD INITIAL SNOW...WHILE THE LOCATION OF THE H850-700 WAA WILL BE
THE DETERMINING FACTOR FOR THE HEAVIER QPF/SNOW. LATEST RUNS SHOW
THIS TO BE FOCUSED OVER THE SOUTHERN HALF OF UPPER MI...BUT IT
SHOULD AFFECT MUCH OF THE CWA TODAY BEFORE QUICKLY EXITING TONIGHT.
DEFINITELY A SHIFT TO THE SOUTH BY ABOUT 10-30 MILES WITH THE AXIS
OF BEST QPF...WITH MOST MODELS NOW SHOWING IT RUNNING ALONG THE WI
BORDER THIS MORNING AND THEN FOCUSING FARTHER NORTHEAST INTO
EASTERN UPPER MICHIGAN AS A SURFACE TROUGH SHARPENS AND ADDITIONAL
MOISTENING OCCURS OFF LAKE MICHIGAN WITH THE WINDS TURNING
SOUTHERLY. THUS...HAVE SHIFTED THE GOING FORECAST SLIGHTLY TOWARDS
THIS LATEST IDEA. SOME OF THE RECENT RAP/HRRR RUNS VARY BACK
AN FORTH ON THAT MORE SOUTHERN IDEA...WHILE THE 00Z ECMWF STILL
KEEPS A MORE NORTHERN SOLUTION. THIS DOES LEAD TO SOME UNCERTAINTY
ON THE NORTHERN SNOWFALL AMOUNTS. THESE TWEAKS ALSO ADJUSTED THE
TIMING SOME WHAT...WITH IT MOVING INTO THE SOUTHWESTERN CWA
AROUND 12Z AND THEN QUICKLY SHIFTING FROM WEST TO EAST AND MUCH OF
THE CWA SEEING SNOW THIS MORNING OR SHORTLY AFTER NOON IN THE
EAST.
WITH THE INITIAL PRECIPITATION OCCURRING WITHOUT TOO MUCH OF THE
LOWER LEVELS BEING SATURATED...THINKING THAT INITIAL SNOW RATIOS
WILL BE IN THE 20-24 TO 1 RANGE. THEN AS THE LOW LEVELS BECOME
SATURATED AND WAA FORCING BECOMES LOCATED BELOW THE DGZ...THERE WILL
BE A QUICK TRANSITION DOWN THROUGH THE TEENS TO A 13 TO 1 SNOW
RATIO. THIS TRANSITION AND IT/S TIMING MAKES FOR A DIFFICULT SNOW
FALL FORECAST...WHICH WILL LIKELY BE RIGHT NEAR ADVISORY LEVELS OVER
EASTERN DELTA...SCHOOLCRAFT...AND SOUTHERN LUCE COUNTIES AS IT MOVES
THROUGH THIS AFTERNOON AND EARLY EVENING. WITH THE ADDITIONAL
MOISTENING AND FORCING FOR THAT AREA BEING ROOTED BELOW THE
DGZ...WONDERING IF THAT WILL BE ENOUGH TO KEEP AMOUNTS AT OR JUST
BELOW THE 3INCH IN 12HR CRITERIA FOR SNOW RATIOS BELOW 20-1. EVEN
WITH THIS SLIGHT SOUTHWARD SHIFT...STILL EXPECT MOST LOCATIONS TO
SEE AN INCH OF SNOW...WITH THE HIGHEST AMOUNTS OVER THE SOUTHERN
U.P. /AROUND 2-2.5 INCHES/ AND OVER THE EAST WHERE LAKE ENHANCEMENT
WILL PUSH VALUES UP TO OR JUST ABOVE 3 INCHES. DUE TO THE
UNCERTAINTY WITH THE NORTHWARD EXTENT ON THE HEAVIEST SNOW AND
CURRENT BORDERLINE ADVISORY AMOUNTS...WILL NOT ISSUE AN ADVISORY AT
THIS POINT BUT KEEP THE MENTION IN THE HWO.
BEHIND THE MAIN WAA PRECIPITATION TODAY...DEEPER MOISTURE REMAINS
OVER THE NORTHERN HALF OF THE CWA TONIGHT AND EXPECT SCATTERED SNOW
SHOWERS THERE AS A SECONDARY WEAK SHORTWAVE MOVES ACROSS LAKE
SUPERIOR. THE KEWEENAW PENINSULA WOULD SEE THE BEST CHANCE FOR
ACCUMULATION...BUT OVERALL AMOUNTS WILL BE LIGHT. SUBSIDENCE WILL BE
ON THE INCREASE OVERNIGHT BEHIND THE SHORTWAVE AND SHOULD BRING AN
END TO THE SNOWFALL. ELSEWHERE...LOW LEVEL MOISTURE WILL BE STUCK
BELOW THE INVERSION FROM THE WAA AROUND H850 THIS AFTERNOON AND
EVENING BEHIND THE SNOW. THIS WILL LEAD TO CLOUDS AND POTENTIAL
FREEZING DRIZZLE CONDITIONS WITH THE LACK OF ICE CRYSTALS IN THE
CLOUDS. WILL CONTINUE THE GOING IDEA IN THE FORECAST...BUT HAVE
OPTED TO SHOW A DIMINISHING TREND OVERNIGHT OVER ALL BUT THE
KEWEENAW AS THE WINDS BECOME A LESS FAVORABLE WHEN THEY SHIFT TO
THE NORTHWEST.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 435 AM EST FRI JAN 18 2013
SAT...NUMERICAL GUIDANCE HAS COME INTO VERY GOOD AGREEMENT SHOWING
VIGOROUS SHRTWV DIGGING SEWD FM NEAR LK WINNIPEG AT 12Z SAT INTO WI
BY LATE IN THE DAY. ASSOCIATED SFC LO IS PROGGED TO MOVE ESEWD OVER
LK SUP TO JUST N-NW OF THE SAULT BY 00Z SUN. THE NAM SHOWS A TRACK A
BIT FARTHER N AND FASTER THAN THE OTHER MODELS...BUT TENDED TOWARD
ITS GUIDANCE PER NCEP PREFERENCE. THE TRACK OF THE SFC-H85 LO/MOST
SGNFT DEEP LYR QVECTOR CNVGC/UPR DVGC TO THE N AND MODEST MSTR
RETURN WL TEND TO LIMIT POPS/SN TOTALS. ANOTHER FACTOR AGAINST A
LARGE SN ACCUM IS FCST THIN DGZ BTWN 10-12K FT. FCST H7 SPECIFIC
HUMIDITY ARND 2 G/KG SUGS AN AVG 1-2 INCH ACCUMULATION FOR A 3-6 HR
PERIOD OF SYNOPTIC SN. BEST CHC FOR THE HIER POPS/SN TOTALS WL BE
OVER THE N AND E CWA. THERE MAY BE LTL ACCUMULATION OVER THE FAR
SCNTRL...ESPECIALLY AT MNM FARTHER FM THE SFC LO TRACK. ALTHOUGH
THERE IS SOME CONCERN THE SW FLOW AHEAD OF THE SFC LO MIGHT BRING
SOME ENHANCEMENT OFF LK MI INTO THE ERN ZNS...LOOKS LIKE THE LLVL
FLOW WL BE SHIFTING TOO STEADILY AND H85 TEMPS MIGHT RISE TOO MUCH
TO OPTIMIZE THE CHC FOR SGNFT ENHANCEMENT OF THE EXPECTED SN TOTALS
IN THIS AREA. SOME PLACES OVER THE E COULD SEE UP TO 3 INCHES.
EXPECT DRYING W-E IN THE AFTN AS LARGER SCALE QVECTOR DVGC/MID LVL
DRYING ARRIVES IN THE WAKE OF THE PASSING LO. SOME LES MIGHT ARRIVE
OVER THE W LATE WITH H85 TEMPS FALLING TOWARD -18 TO -20C BY 00Z SUN.
SAT NGT...WITH INCRSG CYC NW FLOW IN THE WAKE OF DEPARTING SHRTWV/
SFC LO ADVECTING H85 TEMPS UNDER -20C INTO THE CWA...EXPECT LES/BLSN
TO DVLP MAINLY IN THE NW WIND FAVORED SN BELTS. STRONG H925 WINDS
FCST UP TO 35-45 KTS MAY BLOW THE SHSN FARTHER INLAND THAN USUAL.
GIVEN FCST MSTR THRU DEEP CONVECTIVE LYR UNDER FCST INVRN BASE NEAR
8K FT WITHIN SHARP CYC NW FLOW...PERSISTENT LLVL CNVGC IN LONG FETCH
OVER THE LK...AND FCST DGZ UP TO 3K FT...OPTED TO ISSUE A LAKE
EFFECT SN WATCH FOR THE ALGER/LUCE/NRN SCHOOLCRAFT COUNTIES.
ALTHOUGH SOME HEAVIER SHSN MIGHT MOVE INTO THE S HALF OF SCHOOLCRAFT
COUNTY AS WELL LATER AT NGT...DID NOT INCLUDE THAT AREA IN THE WATCH
GIVEN SMALLER WINDOW OF OPPORTUNITY BEFORE WINDS DIMINISH ON
SUN...SEE BLO. ALTHOUGH AN LES/BLSN ADVY WL ALMOST CERTAINLY BE
NECESSARY FOR MUCH OF THE NW CWA...OPTED TO HOLD OFF ON A WATCH ATTM
BECAUSE SHORTER FETCH OVER THE WRN LK IS FCST TO RESULT IN LESS
WARMING...WITH DGZ CONFINED TO ONLY THE NEAR SFC LYR PER FCST SDNGS.
HOWEVER...THE COMBINATION OF SMALLER SN FLAKES/STRONG WINDS/BLSN WL
FAVOR SHARPLY REDUCED VSBYS EVEN IF SN TOTALS ARE LESS THAN OVER THE
SN BELTS E OF MQT. STRENTH OF NW FLOW SHOULD ADVECT LK MODERATION
FAR ENUF INLAND TO MITIGATE THE CHILL OVER EVEN THE FAR SCNTRL AND
PREVENT WIND CHILLS FM FALLING BLO ADVY THRESHOLD.
SUN/SUN NGT...THE GRADIENT NW FLOW IS FCST TO DIMINISH FAIRLY
STEADILY THRU THE DAY ON SUN AS SFC LO IN ERN CAN LIFTS TO THE NE.
LES WL PERSIST IN THE NW WIND SN BELTS THRU THIS TIME...SO WENT WITH
CATEGORICAL POPS IN THESE AREAS. MAINTAINED WATCH FOR ALGER/LUCE/N
HALF OF SCHOOLCRAFT COUNTIES THRU SUN NGT. PASSAGE OF SHRTWV/AREA OF
DEEP LYR QVECTOR DNVGC/DEEP MSTR ON SUN AFTN/EVNG MIGHT BRING SOME
-SHSN/FLURRIES TO EVEN THE SCNTRL. AS THE LLVL FLOW BACKS A BIT MORE
SUN NGT AND ADVECTS MORE UNMODIFIED ARCTIC AIR INTO THAT AREA...WIND
CHILLS MIGHT AT LEAST APRCH ADVY CRITERIA OVER THE SCNTRL.
EXTENDED PERIOD...THE FIRST HALF OF NEXT WEEK WL BE DOMINATED BY
DEEP UPR TROF OVER ERN NAMERICA WITH NW FLOW OVER THE CWA HELD IN
PLACE BY HI LATITUDE BLOCKING...A CLASSIC NEGATIVE NAO PATTERN THAT
FAVORS WELL BLO NORMAL TEMPS OVER THE GRT LKS. EXPECT PERSISTENT NW
FLOW OF ARCTIC AIR WITH H85 TEMPS AS LO AS -25 TO -30C TO BRING
NEARLY CONTINUOUS LES IN THE FAVORED SN BELTS. SO TENDED TO FCST
HIER POPS THAN MODEL CONSENSUS IN THESE AREAS ON MON INTO WED. IN
FACT...FUTURE SHIFTS WL LIKELY NEED TO EXTEND HEADLINE FOR THE ERN
ZNS INTO THIS TIME. ALTHOUGH THERE COULD BE SOME CLIPPER TYPE
SHRTWVS MOVING THRU THIS FLOW...OVERALL DRYNESS OF THE AIRMASS
INDICATES THE SCNTRL COUNTIES WL SEE NOTHING MORE THAN FLURRIES ON
THESE DAYS. WIND CHILLS OVER THE INTERIOR SCENTRAL COULD APRCH ADVY
LVLS AT TIMES. AS THE UPR TROF/ARCTIC BRANCH SLOWLY RETREAT EWD THRU
SE CANADA AFTER WED...A LO PRES DVLPG IN THE PLAINS WITHIN MORE
ACTIVE AND MSTR LADEN POLAR BRANCH WL MOVE TOWARD THE GREAT LKS BY
THU...BRINGING AN END TO THE PERSISTENT COLD/LES BUT THEN THE THREAT
OF AT LEAST A MODERATE SYNOPTIC SN EVENT BY THU.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 645 AM EST FRI JAN 18 2013
A WARM FRONT MOVING THROUGH MINNESOTA AND WISCONSIN WILL PRODUCE
AND AREA OF SNOW THAT SLIDES FROM WEST TO EAST ACROSS UPPER
MICHIGAN. THE SNOW WILL HAVE THE GREATEST INFLUENCE ON
KIWD/KSAW...WITH SLIGHTLY LIGHTER SNOW AT KCMX. KIWD SHOULD SEE THE
VISIBILITIES DROP AT OR SHORTLY AFTER TAF EFFECTIVE TIME...WITH
KCMX/KSAW AROUND MID MORNING. THERE IS SOME UNCERTAINTY IN THE
EXACT LOCATION OF THE HEAVIEST SNOW...BUT FELT CONFIDENT ENOUGH TO
DROP VISIBILITIES TO LIFR AT BOTH KIWD/KSAW. WITH SOUTHERLY
FLOW...EXPECT THE CEILINGS TO FALL NEAR OR SLIGHTLY BELOW
IFR DURING THE HEAVIEST SNOW.
WITH THE SNOW DEPARTING DURING THE EARLY AFTERNOON...LINGERING LOW
LEVEL MOISTURE WILL KEEP LOW END MVFR CEILINGS WITH ISOLATED SNOW
SHOWERS OR PATCHY FREEZING DRIZZLE. WASN/T CONFIDENT ENOUGH IN
TIMING/LOCATION OF THE FREEZING DRIZZLE TO PUT IT IN...SO FUTURE
SHIFTS WILL NEED TO MONITOR. AS WINDS SHIFT TO THE WEST
OVERNIGHT...THE CEILINGS SHOULD LIFT SOME...BUT THE NEXT LOW
PRESSURE WILL BE APPROACHING WESTERN LAKE SUPERIOR AT THAT TIME AND
KEEP THEM FROM RISING TOO MUCH AT KIWD/KCMX.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 435 AM EST FRI JAN 18 2013
THE COMBINATION OF A DEPARTING HIGH PRESSURE RIDGE AND A WEAK LOW
PRESSURE TROUGH MOVING THROUGH THE UPPER MISSISSIPPI VALLEY TODAY
WILL LEAD TO DIMINISHING WINDS BELOW 20KTS. THESE LIGHT WINDS WILL
REMAIN THROUGH TONIGHT.
EXPECT NW GALES TO 35 TO 40 KTS TO DEVELOP OVER WESTERN LK SUP LATE
SAT IN THE WAKE OF LO PRES MOVING INTO ONTARIO AND THEN OVERSPREAD
THE REST OF THE LK ON SAT NIGHT WHILE INCREASING UP TO 40 TO 45 KTS.
SINCE ARCTIC AIR WILL BE MOVING IN...HEAVY FREEZING SPRAY WILL
DEVELOP AS WELL. GALES/HEAVY FREEZING SPRAY WILL THEN DIMINISH ON SUN
W-E AS LO PRES TO THE E MOVES FARTHER AWAY AND WEAKER PRES GRADIENT
MOVES INTO THE AREA. FOR EARLY NEXT WEEK...EXPECT PERSISTENT NW WINDS
25 TO 30 KTS TO ADVECT ARCTIC AIR OVER LK SUP AND RESULT IN PERIODS
OF HEAVY FREEZING SPRAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WATCH FROM SATURDAY EVENING THROUGH MONDAY
MORNING FOR MIZ006-007-085.
WINTER WEATHER ADVISORY UNTIL 11 PM EST THIS EVENING FOR MIZ007-
013-014-085.
LAKE SUPERIOR...
GALE WATCH FROM SATURDAY AFTERNOON THROUGH SUNDAY AFTERNOON FOR
LSZ245>251-265>267.
HEAVY FREEZING SPRAY WATCH FROM LATE SATURDAY NIGHT THROUGH
TUESDAY MORNING FOR LSZ245>251-265>267.
GALE WATCH FROM SATURDAY AFTERNOON THROUGH SUNDAY MORNING FOR
LSZ162-240>244-263-264.
HEAVY FREEZING SPRAY WATCH FROM SATURDAY EVENING THROUGH MONDAY
EVENING FOR LSZ162-240>244-263-264.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...JLA
SHORT TERM...SRF
LONG TERM...KC
AVIATION...SRF
MARINE...SRF/KC
YOU CAN SEE AN ILLUSTRATED VERSION OF THE FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML.
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
530 AM CST FRI JAN 18 2013
.SHORT TERM...TODAY THROUGH SUNDAY NIGHT
314 AM CST FRI JAN 18 2013
THE MAIN FOCUS THROUGH THE WEEKEND IS WITH PRECIPITATION CHANCES
ALONG WITH THE TEMPERATURE DROP AND STRONG WINDS BEHIND THE FIRST
IN A SERIES OF COLD FRONTS THAT WILL MOVE THROUGH THE REGION.
CURRENTLY...A BAND OF SNOW EXTENDS FROM CENTRAL MINNESOTA DOWN
INTO SOUTHWEST WISCONSIN AHEAD OF A SURFACE WARM FRONT AND WILL
QUICKLY PROPAGATE TO THE EAST THIS MORNING. SOME OF THIS SNOW HAS
TAKEN ON A CONVECTIVE LOOK TO IT ACROSS CENTRAL MINNESOTA...LIKELY
DUE TO THE LOW LEVEL FRONTOGENESIS BEING SHOWN THERE ON 18.06Z RAP
CROSS SECTIONS...WITH SOME VISIBILITIES DROPPING DOWN TO A MILE AT
TIMES. THIS SNOW WILL BE OUT OF THE FORECAST AREA QUICKLY THIS
MORNING WITH SNOW TOTALS STILL LOOKS TO BE AROUND AN INCH OR TWO
IN NORTH CENTRAL WISCONSIN WITH LESS THAN AN INCH SOUTH OF CLARK
COUNTY WISCONSIN. CONFIDENCE NOT VERY HIGH THAT FREEZING DRIZZLE
WILL OCCUR AS THERE HAS BEEN LITTLE IN REPORTS OF IT ALONG THE
BACK EDGE OF THE SNOW. 18.06Z RAP SOUNDINGS SHOW THAT IF THERE IS
AN AREA WHERE THE FREEZING DRIZZLE IS POSSIBLE...IT MAY BE ACROSS
NORTH CENTRAL WISCONSIN WHERE THE COLUMN MAY LOSE ICE WITH LOW
LEVEL LIFT STILL STRONG. CEILINGS HAVE NOT BEEN VERY LOW
THOUGH...MAINLY ABOVE 2KFT...SO THINK THAT THE LOW LEVEL RH MAY BE
A LITTLE OVERDONE. WILL LEAVE THE FZDZ MENTION IN THE FORECAST FOR
NOW...BUT HAVE TRIMMED IT BACK TO JUST BEING POSSIBLE IN WEST
CENTRAL WISCONSIN...MAINLY ALONG AND NORTH OF I-94.
THE NEXT QUESTION IS WITH TEMPERATURES TODAY WITH MUCH OF THE
REGION BEING IN THE WARM SECTOR AS A WARM FRONT LIFTS NORTHEAST OF
THE REGION. THOUGH 850MB TEMPERATURES ARE ONLY AROUND 1 STANDARD
DEVIATION ABOVE THE NORM...HIGHS MAY COME CLOSE TO A RECORD AT
RST WHERE THE PREVIOUS RECORD IS 46. WITH JUST MID TO UPPER LEVEL
CLOUD COVER TO CONTEND WITH...AND LITTLE TO NO SNOW ON THE
GROUND...TEMPERATURES SHOULD CLIMB INTO THE 40S ACROSS MUCH OF THE
REGION. THE ECMWF HAS BEEN OUR BEST VERIFYING GUIDANCE WITH THE
RECENT WARM DAYS...SO HAVE FOLLOWED IT WITH THE TRENDS FOR TODAY.
THE HAMMER DROPS SATURDAY AS THE FIRST COLD FRONT COMES THROUGH IN
THE AFTERNOON WITH A SECONDARY ONE COMING THROUGH IN THE EVENING
THAT WILL BRING DOWN THE MUCH COLDER AIR AND STRONG/GUSTY WINDS.
THE STRONG COLD AIR ADVECTION AND TIGHT PRESSURE GRADIENT WILL
LEAD TO WIND GUSTS UP INTO THE 40MPH RANGE SATURDAY EVENING RIGHT
AFTER FROPA. THIS COMBINATION OF DROPPING TEMPERATURES AND GUSTY
WINDS COULD LEAD TO THE WIND CHILL DROPPING INTO THE -20F TO -25F
RANGE ACROSS SOUTHEAST MINNESOTA AND WESTERN WISCONSIN TO WHERE A
WIND CHILL ADVISORY MAY BE NEEDED. BUMPED UP CLOUD COVER A BIT
AND ADDED SOME FLURRIES BEHIND THE COLD FRONT AS 18.00Z NAM/GFS
SOUNDINGS SHOW SOME LOW LEVEL RH DROPPING INTO THE -10C TO -20C
RANGE.
ANOTHER WEAKLY FORCED SYSTEM WILL MOVE THROUGH IOWA ON SUNDAY AND
BRING ANOTHER POSSIBLE ROUND OF LIGHT SNOW ALONG WITH IT. WITH A
RIDGE OF HIGH PRESSURE PUSHING DOWN FROM THE NORTHWEST THOUGH...IT
WILL BE HARD TO SQUEEZE OUT MUCH IN THE WAY OF PRECIPITATION.
.LONG TERM...MONDAY THROUGH THURSDAY
314 AM CST FRI JAN 18 2013
THE MAIN FOCUS INTO NEXT WEEK IS WITH THE TEMPERATURES AND HOW LOW
THEY WILL GO. THE LACK OF SNOW ON THE GROUND WILL HELP TO KEEP
TEMPERATURES UP ABOUT 10 DEGREES FROM WHERE THEY NORMALLY COULD
DROP TO...BUT EVEN SO LOWS WILL DROP WELL BELOW ZERO MONDAY
MORNING AND TUESDAY MORNING. THE 18.00Z GEM IS THE COLDEST OF THE
MODEL RUNS WITH HAVING 850MB TEMPERATURES DROPPING DOWN TO -32C BY
MONDAY AFTERNOON...BUT THAT APPEARS TO BE A BIT EXTREME COMPARED
TO THE 18.00Z GFS/ECMWF WHICH HAVE 850MB TEMPERATURES AROUND -24C
AT THAT SAME TIME. WIND CHILL ADVISORIES WILL LIKELY BE NEEDED
MONDAY AND TUESDAY WITH WIND CHILLS DROPPING DOWN INTO THE -20F TO
-30F RANGE. THE SURFACE RIDGE AXIS PASSES BY ON WEDNESDAY MORNING
WITH WARMER LOW LEVEL AIR MOVING BACK IN THROUGH THE REST OF THE
WEEK. THE 18.00Z GFS/ECMWF CONTINUE TO HINT AT A LATE WEEK SYSTEM
MOVING THROUGH THE REGION...BUT THERE IS CONSIDERABLE SPREAD ON
WHERE THIS SYSTEM WILL TRACK.
&&
.AVIATION...TODAY AND TONIGHT
530 AM CST FRI JAN 18 2013
CURRENT SURFACE MAP HAS A WARM FRONT EXTENDING FROM SD THROUGH
CENTRAL IA...MOVING NORTH INTO THE UPPER MISSISSIPPI RIVER REGION.
RADAR SHOWING -SN ACTIVITY ASSOCIATED WITH LIFT AHEAD OF THE WARM
FRONT WAS NOW ALONG/NORTHEAST OF I-94 WITH VFR CLOUD AT KRST/KLSE
TAF SITES. PLAN ON THE WARM FRONT TO LIFT NORTH OF THE AREA BY
LATER THIS MORNING WITH WINDS PICKING UP FROM THE SOUTH/SOUTHWEST
IN THE WARM SECTOR ALONG WITH SOME PATCHY ALTOCUMULUS FROM TIME TO
TIME. A WEAK MID-LEVEL TROUGH IS EXPECTED TO SPREAD BROKEN LAYER
OF ALTOCUMULUS WITH BASES AOA 8KFT INTO THE AREA LATE THIS
EVENING/OVERNIGHT. OTHERWISE...VFR CONDITIONS EXPECTED THROUGH
TONIGHT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
314 AM CST FRI JAN 18 2013
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...DAS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
107 PM EST FRI JAN 18 2013
.UPDATE...
ISSUED AT 1023 AM EST FRI JAN 18 2013
WARM AIR ADVECTION EVIDENT UPSTREAM ON SOUTHERN FRINGE OF UPPER
TROUGH OVER HUDSON BAY/NORTHERN QUEBEC. WARM AIR ADVECTION AND H8-H6
FRONTOGENESIS IN ENTRANCE REGION OF JET STREAK OVER ONTARIO AFFECTS
THE AREA WITH WIDESPREAD SNOW TODAY. H8-H7 FRONTOGENESIS EXPECTED TO
EXPAND EAST ACROSS SOUTHERN TIER THIS MORNING AND ACROSS LK MICHIGAN
ZONES THIS AFTN AND INTO EVENING. 12Z NAM IS CONSISTENT WITH 06Z RUN
AND MATCHES WELL WITH RUC/LOCAL-WRF AND MOST IMPORTANTLY REALITY
BASED ON RADAR/SFC OBS. EXPECT INCREASING SNOW OVER SCNTRL AND
SOUTHEAST CWA THROUGH AFTN...CUTTING OUT FIRST ALONG WI BORDER.
BASED ON LOCAL WRF AND RUC QPF AMOUNTS ALONG WITH EXPECTED SNOW
RATIOS SOMEWHERE IN 10-17:1 RANGE...EXPECT ADVY SNOW AMOUNTS UP TO 5
INCHES OVR PORTIONS OF SCNTRL AND SOUTHEAST/EAST ZONES FOR THIS
EVENT. SOUTHWEST FLOW OFF LK MICHIGAN WITH TEMPS AT INVERSION TOP
AROUND -10C LEADING TO SUFFICIENT OVER-WATER INSTABILITY ALSO COULD
RESULT IN ADDITIONAL INCH OR TWO DUE TO LAKE ENHANCEMENT.
SO...COORD WITH APX AND ISSUED WINTER WEATHER ADVY INTO THE EVENING
FOR DELTA THROUGH LUCE COUNTIES. FARTHER WEST...THERE IS POTENTIAL
FOR ENHANCED BAND OF SNOW TO PUSH TOTALS PAST 3 INCHES...BUT SINCE
HEAVIER SNOW FROM GOGEBIC THROUGH MENOMINEE ONLY LASTS INTO MID AFTN
AND WILL BE PRETTY LOCALIZED...PLAN NOT ISSUE ADVY THERE AND CONTINUE
TO ADDRESS VIA SPECIAL WEATHER STATEMENTS. THAT COULD CHANGE BASED ON
REPORTS THOUGH. BASED ON SOUNDINGS WHEN SNOW CUTS OUT THIS AFTN...SHOULD
SEE TRANSITION TO LGT SNOW AND/OR FREEZING DRIZZLE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 435 AM EST FRI JAN 18 2013
SATELLITE AND RADAR ARE SHOWING THE LAKE EFFECT STILL ONGOING
OVER THE KEWEENAW AND FOR LOCATIONS EAST OF MUNISING. WITH WINDS
CONTINUING TO BACK TO THE WEST AND THEN SOUTHWEST EARLY THIS
MORNING...EXPECT THE LAKE EFFECT TO FOLLOW SUIT AND DEPART THE
EASTERN CWA THIS MORNING. WITH THE INTENSITY OF THE SNOW
DIMINISHING AND A STEADY MOVEMENT EASTWARD...WILL LET THE
ADVISORY EXPIRE AT 12Z. ELSEWHERE...THE HIGH PRESSURE RIDGE OVER
THE CWA AT THIS TIME HAS LED TO A PERIOD OF CLEAR SKIES OVER THE
CENTRAL CWA FOR A PERIOD THIS MORNING...ALLOWING SOME LOCATIONS TO
DROP INTO THE SINGLE DIGITS BELOW ZERO. MID AND HIGH CLOUDS HAVE
STOPPED THE TEMP DROP ALONG THE WISCONSIN BORDER AS THEY MOVE OVER
THE CWA AHEAD OF THE MAIN WEATHER MAKER FOR TODAY.
THE AREA OF LOW PRESSURE IS CURRENTLY IN SOUTHERN
SASKATCHEWAN...BUT AN SURFACE TROUGH STRETCHING SOUTHEAST THROUGH
THE DAKOTAS AND ASSOCIATED H850 TROUGH TO THE NORTHEAST OF THAT HAS
LED TO LIGHT SNOW UNDER THE BROAD WARM AIR ADVECTION THIS MORNING
IN MN AND WESTERN WI. THE LOW IS EXPECTED TO DROP SOUTHEAST THROUGH
NORTHERN MN TODAY AND INTO NORTHERN WISCONSIN OR SOUTHERN UPPER
MICHIGAN BY 00Z SATURDAY. WITH THE RIGHT REAR OF THE UPPER JET
MOVING OVER UPPER MICHIGAN AND THE SHORTWAVE MOVING THROUGH THIS
AFTERNOON AND EARLY EVENING...EXPECT THE LOW TO INTENSIFY SOME. THE
MAIN FOCUS FOR THE SNOW WILL BE THE STRONG H850-700 AND H700-500
WARM AIR ADVECTION AND ASSOCIATED FGEN ON THE H850-600 LAYER. THE
H700-500 WAA MOVES DIRECTLY ACROSS THE CWA AND THAT WILL LEAD THE
BROAD INITIAL SNOW...WHILE THE LOCATION OF THE H850-700 WAA WILL BE
THE DETERMINING FACTOR FOR THE HEAVIER QPF/SNOW. LATEST RUNS SHOW
THIS TO BE FOCUSED OVER THE SOUTHERN HALF OF UPPER MI...BUT IT
SHOULD AFFECT MUCH OF THE CWA TODAY BEFORE QUICKLY EXITING TONIGHT.
DEFINITELY A SHIFT TO THE SOUTH BY ABOUT 10-30 MILES WITH THE AXIS
OF BEST QPF...WITH MOST MODELS NOW SHOWING IT RUNNING ALONG THE WI
BORDER THIS MORNING AND THEN FOCUSING FARTHER NORTHEAST INTO
EASTERN UPPER MICHIGAN AS A SURFACE TROUGH SHARPENS AND ADDITIONAL
MOISTENING OCCURS OFF LAKE MICHIGAN WITH THE WINDS TURNING
SOUTHERLY. THUS...HAVE SHIFTED THE GOING FORECAST SLIGHTLY TOWARDS
THIS LATEST IDEA. SOME OF THE RECENT RAP/HRRR RUNS VARY BACK
AN FORTH ON THAT MORE SOUTHERN IDEA...WHILE THE 00Z ECMWF STILL
KEEPS A MORE NORTHERN SOLUTION. THIS DOES LEAD TO SOME UNCERTAINTY
ON THE NORTHERN SNOWFALL AMOUNTS. THESE TWEAKS ALSO ADJUSTED THE
TIMING SOME WHAT...WITH IT MOVING INTO THE SOUTHWESTERN CWA
AROUND 12Z AND THEN QUICKLY SHIFTING FROM WEST TO EAST AND MUCH OF
THE CWA SEEING SNOW THIS MORNING OR SHORTLY AFTER NOON IN THE
EAST.
WITH THE INITIAL PRECIPITATION OCCURRING WITHOUT TOO MUCH OF THE
LOWER LEVELS BEING SATURATED...THINKING THAT INITIAL SNOW RATIOS
WILL BE IN THE 20-24 TO 1 RANGE. THEN AS THE LOW LEVELS BECOME
SATURATED AND WAA FORCING BECOMES LOCATED BELOW THE DGZ...THERE WILL
BE A QUICK TRANSITION DOWN THROUGH THE TEENS TO A 13 TO 1 SNOW
RATIO. THIS TRANSITION AND IT/S TIMING MAKES FOR A DIFFICULT SNOW
FALL FORECAST...WHICH WILL LIKELY BE RIGHT NEAR ADVISORY LEVELS OVER
EASTERN DELTA...SCHOOLCRAFT...AND SOUTHERN LUCE COUNTIES AS IT MOVES
THROUGH THIS AFTERNOON AND EARLY EVENING. WITH THE ADDITIONAL
MOISTENING AND FORCING FOR THAT AREA BEING ROOTED BELOW THE
DGZ...WONDERING IF THAT WILL BE ENOUGH TO KEEP AMOUNTS AT OR JUST
BELOW THE 3INCH IN 12HR CRITERIA FOR SNOW RATIOS BELOW 20-1. EVEN
WITH THIS SLIGHT SOUTHWARD SHIFT...STILL EXPECT MOST LOCATIONS TO
SEE AN INCH OF SNOW...WITH THE HIGHEST AMOUNTS OVER THE SOUTHERN
U.P. /AROUND 2-2.5 INCHES/ AND OVER THE EAST WHERE LAKE ENHANCEMENT
WILL PUSH VALUES UP TO OR JUST ABOVE 3 INCHES. DUE TO THE
UNCERTAINTY WITH THE NORTHWARD EXTENT ON THE HEAVIEST SNOW AND
CURRENT BORDERLINE ADVISORY AMOUNTS...WILL NOT ISSUE AN ADVISORY AT
THIS POINT BUT KEEP THE MENTION IN THE HWO.
BEHIND THE MAIN WAA PRECIPITATION TODAY...DEEPER MOISTURE REMAINS
OVER THE NORTHERN HALF OF THE CWA TONIGHT AND EXPECT SCATTERED SNOW
SHOWERS THERE AS A SECONDARY WEAK SHORTWAVE MOVES ACROSS LAKE
SUPERIOR. THE KEWEENAW PENINSULA WOULD SEE THE BEST CHANCE FOR
ACCUMULATION...BUT OVERALL AMOUNTS WILL BE LIGHT. SUBSIDENCE WILL BE
ON THE INCREASE OVERNIGHT BEHIND THE SHORTWAVE AND SHOULD BRING AN
END TO THE SNOWFALL. ELSEWHERE...LOW LEVEL MOISTURE WILL BE STUCK
BELOW THE INVERSION FROM THE WAA AROUND H850 THIS AFTERNOON AND
EVENING BEHIND THE SNOW. THIS WILL LEAD TO CLOUDS AND POTENTIAL
FREEZING DRIZZLE CONDITIONS WITH THE LACK OF ICE CRYSTALS IN THE
CLOUDS. WILL CONTINUE THE GOING IDEA IN THE FORECAST...BUT HAVE
OPTED TO SHOW A DIMINISHING TREND OVERNIGHT OVER ALL BUT THE
KEWEENAW AS THE WINDS BECOME A LESS FAVORABLE WHEN THEY SHIFT TO
THE NORTHWEST.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 435 AM EST FRI JAN 18 2013
SAT...NUMERICAL GUIDANCE HAS COME INTO VERY GOOD AGREEMENT SHOWING
VIGOROUS SHRTWV DIGGING SEWD FM NEAR LK WINNIPEG AT 12Z SAT INTO WI
BY LATE IN THE DAY. ASSOCIATED SFC LO IS PROGGED TO MOVE ESEWD OVER
LK SUP TO JUST N-NW OF THE SAULT BY 00Z SUN. THE NAM SHOWS A TRACK A
BIT FARTHER N AND FASTER THAN THE OTHER MODELS...BUT TENDED TOWARD
ITS GUIDANCE PER NCEP PREFERENCE. THE TRACK OF THE SFC-H85 LO/MOST
SGNFT DEEP LYR QVECTOR CNVGC/UPR DVGC TO THE N AND MODEST MSTR
RETURN WL TEND TO LIMIT POPS/SN TOTALS. ANOTHER FACTOR AGAINST A
LARGE SN ACCUM IS FCST THIN DGZ BTWN 10-12K FT. FCST H7 SPECIFIC
HUMIDITY ARND 2 G/KG SUGS AN AVG 1-2 INCH ACCUMULATION FOR A 3-6 HR
PERIOD OF SYNOPTIC SN. BEST CHC FOR THE HIER POPS/SN TOTALS WL BE
OVER THE N AND E CWA. THERE MAY BE LTL ACCUMULATION OVER THE FAR
SCNTRL...ESPECIALLY AT MNM FARTHER FM THE SFC LO TRACK. ALTHOUGH
THERE IS SOME CONCERN THE SW FLOW AHEAD OF THE SFC LO MIGHT BRING
SOME ENHANCEMENT OFF LK MI INTO THE ERN ZNS...LOOKS LIKE THE LLVL
FLOW WL BE SHIFTING TOO STEADILY AND H85 TEMPS MIGHT RISE TOO MUCH
TO OPTIMIZE THE CHC FOR SGNFT ENHANCEMENT OF THE EXPECTED SN TOTALS
IN THIS AREA. SOME PLACES OVER THE E COULD SEE UP TO 3 INCHES.
EXPECT DRYING W-E IN THE AFTN AS LARGER SCALE QVECTOR DVGC/MID LVL
DRYING ARRIVES IN THE WAKE OF THE PASSING LO. SOME LES MIGHT ARRIVE
OVER THE W LATE WITH H85 TEMPS FALLING TOWARD -18 TO -20C BY 00Z SUN.
SAT NGT...WITH INCRSG CYC NW FLOW IN THE WAKE OF DEPARTING SHRTWV/
SFC LO ADVECTING H85 TEMPS UNDER -20C INTO THE CWA...EXPECT LES/BLSN
TO DVLP MAINLY IN THE NW WIND FAVORED SN BELTS. STRONG H925 WINDS
FCST UP TO 35-45 KTS MAY BLOW THE SHSN FARTHER INLAND THAN USUAL.
GIVEN FCST MSTR THRU DEEP CONVECTIVE LYR UNDER FCST INVRN BASE NEAR
8K FT WITHIN SHARP CYC NW FLOW...PERSISTENT LLVL CNVGC IN LONG FETCH
OVER THE LK...AND FCST DGZ UP TO 3K FT...OPTED TO ISSUE A LAKE
EFFECT SN WATCH FOR THE ALGER/LUCE/NRN SCHOOLCRAFT COUNTIES.
ALTHOUGH SOME HEAVIER SHSN MIGHT MOVE INTO THE S HALF OF SCHOOLCRAFT
COUNTY AS WELL LATER AT NGT...DID NOT INCLUDE THAT AREA IN THE WATCH
GIVEN SMALLER WINDOW OF OPPORTUNITY BEFORE WINDS DIMINISH ON
SUN...SEE BLO. ALTHOUGH AN LES/BLSN ADVY WL ALMOST CERTAINLY BE
NECESSARY FOR MUCH OF THE NW CWA...OPTED TO HOLD OFF ON A WATCH ATTM
BECAUSE SHORTER FETCH OVER THE WRN LK IS FCST TO RESULT IN LESS
WARMING...WITH DGZ CONFINED TO ONLY THE NEAR SFC LYR PER FCST SDNGS.
HOWEVER...THE COMBINATION OF SMALLER SN FLAKES/STRONG WINDS/BLSN WL
FAVOR SHARPLY REDUCED VSBYS EVEN IF SN TOTALS ARE LESS THAN OVER THE
SN BELTS E OF MQT. STRENTH OF NW FLOW SHOULD ADVECT LK MODERATION
FAR ENUF INLAND TO MITIGATE THE CHILL OVER EVEN THE FAR SCNTRL AND
PREVENT WIND CHILLS FM FALLING BLO ADVY THRESHOLD.
SUN/SUN NGT...THE GRADIENT NW FLOW IS FCST TO DIMINISH FAIRLY
STEADILY THRU THE DAY ON SUN AS SFC LO IN ERN CAN LIFTS TO THE NE.
LES WL PERSIST IN THE NW WIND SN BELTS THRU THIS TIME...SO WENT WITH
CATEGORICAL POPS IN THESE AREAS. MAINTAINED WATCH FOR ALGER/LUCE/N
HALF OF SCHOOLCRAFT COUNTIES THRU SUN NGT. PASSAGE OF SHRTWV/AREA OF
DEEP LYR QVECTOR DNVGC/DEEP MSTR ON SUN AFTN/EVNG MIGHT BRING SOME
-SHSN/FLURRIES TO EVEN THE SCNTRL. AS THE LLVL FLOW BACKS A BIT MORE
SUN NGT AND ADVECTS MORE UNMODIFIED ARCTIC AIR INTO THAT AREA...WIND
CHILLS MIGHT AT LEAST APRCH ADVY CRITERIA OVER THE SCNTRL.
EXTENDED PERIOD...THE FIRST HALF OF NEXT WEEK WL BE DOMINATED BY
DEEP UPR TROF OVER ERN NAMERICA WITH NW FLOW OVER THE CWA HELD IN
PLACE BY HI LATITUDE BLOCKING...A CLASSIC NEGATIVE NAO PATTERN THAT
FAVORS WELL BLO NORMAL TEMPS OVER THE GRT LKS. EXPECT PERSISTENT NW
FLOW OF ARCTIC AIR WITH H85 TEMPS AS LO AS -25 TO -30C TO BRING
NEARLY CONTINUOUS LES IN THE FAVORED SN BELTS. SO TENDED TO FCST
HIER POPS THAN MODEL CONSENSUS IN THESE AREAS ON MON INTO WED. IN
FACT...FUTURE SHIFTS WL LIKELY NEED TO EXTEND HEADLINE FOR THE ERN
ZNS INTO THIS TIME. ALTHOUGH THERE COULD BE SOME CLIPPER TYPE
SHRTWVS MOVING THRU THIS FLOW...OVERALL DRYNESS OF THE AIRMASS
INDICATES THE SCNTRL COUNTIES WL SEE NOTHING MORE THAN FLURRIES ON
THESE DAYS. WIND CHILLS OVER THE INTERIOR SCENTRAL COULD APRCH ADVY
LVLS AT TIMES. AS THE UPR TROF/ARCTIC BRANCH SLOWLY RETREAT EWD THRU
SE CANADA AFTER WED...A LO PRES DVLPG IN THE PLAINS WITHIN MORE
ACTIVE AND MSTR LADEN POLAR BRANCH WL MOVE TOWARD THE GREAT LKS BY
THU...BRINGING AN END TO THE PERSISTENT COLD/LES BUT THEN THE THREAT
OF AT LEAST A MODERATE SYNOPTIC SN EVENT BY THU.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 106 PM EST FRI JAN 18 2013
WARM AIR ADVECTION IS PRODUCING WIDESPREAD SNOWFALL ACROSS UPPER MI
EARLY THIS AFTERNOON...WITH THE MORE EXPANSIVE COVERAGE MOVING OUT
FROM THE THREE TAF SITES. A SECONDARY NARROW BAND OF SNOW CURRENTLY
OVER WESTERN UPPER MI IS EXPECTED TO MOVE THROUGH IWD OVER THE NEXT
COUPLE HOURS...AND STAY SOUTH OF CMX AND SAW. WINDS WILL NOT BE A
MAJOR CONCERN AS THEY SHOULD GENERALLY STAY BELOW 10KTS ACROSS THE
AREA. HOWEVER...SOME UPSLOPE FAVORED DIRECTIONS WILL KEEP CIGS LOWER
AT SAW INTO THIS EVENING. AS FOR CMX...WIND DIRECTION IS QUITE
TRICKY FROM THIS EVENING ON AS A TROUGH LOOKS TO PLACE ITSELF RIGHT
OVER THE AREA. PUT VARIABLE WINDS IN THE TAF BEGINNING THIS EVENING
AT CMX...THOUGH FAVORED DIRECTIONS WILL BE FROM BETWEEN NORTH AND
EAST.
A FINAL NOTE...WINDS WILL QUICKLY SHIFT AND INCREASE AT ALL SITES
SATURDAY AFTERNOON...THOUGH TIMING FOR ALL SITES IS STILL UNCERTAIN.
WESTERLY GUSTS OF AT LEAST 30KTS WILL BE POSSIBLE FOR IWD AND CMX AT
OR JUST AFTER THE END OF THIS TAF PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 435 AM EST FRI JAN 18 2013
THE COMBINATION OF A DEPARTING HIGH PRESSURE RIDGE AND A WEAK LOW
PRESSURE TROUGH MOVING THROUGH THE UPPER MISSISSIPPI VALLEY TODAY
WILL LEAD TO DIMINISHING WINDS BELOW 20KTS. THESE LIGHT WINDS WILL
REMAIN THROUGH TONIGHT.
EXPECT NW GALES TO 35 TO 40 KTS TO DEVELOP OVER WESTERN LK SUP LATE
SAT IN THE WAKE OF LO PRES MOVING INTO ONTARIO AND THEN OVERSPREAD
THE REST OF THE LK ON SAT NIGHT WHILE INCREASING UP TO 40 TO 45 KTS.
SINCE ARCTIC AIR WILL BE MOVING IN...HEAVY FREEZING SPRAY WILL
DEVELOP AS WELL. GALES/HEAVY FREEZING SPRAY WILL THEN DIMINISH ON SUN
W-E AS LO PRES TO THE E MOVES FARTHER AWAY AND WEAKER PRES GRADIENT
MOVES INTO THE AREA. FOR EARLY NEXT WEEK...EXPECT PERSISTENT NW WINDS
25 TO 30 KTS TO ADVECT ARCTIC AIR OVER LK SUP AND RESULT IN PERIODS
OF HEAVY FREEZING SPRAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WATCH FROM SATURDAY EVENING THROUGH MONDAY
MORNING FOR MIZ006-007-085.
WINTER WEATHER ADVISORY UNTIL 11 PM EST THIS EVENING FOR MIZ007-
013-014-085.
WINTER WEATHER ADVISORY UNTIL 2 PM CST THIS AFTERNOON FOR MIZ009-
010.
WINTER WEATHER ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR MIZ011-
012.
LAKE SUPERIOR...
GALE WATCH FROM SATURDAY AFTERNOON THROUGH SUNDAY AFTERNOON FOR
LSZ245>251-265>267.
HEAVY FREEZING SPRAY WATCH FROM LATE SATURDAY NIGHT THROUGH
TUESDAY MORNING FOR LSZ245>251-265>267.
GALE WATCH FROM SATURDAY AFTERNOON THROUGH SUNDAY MORNING FOR
LSZ162-240>244-263-264.
HEAVY FREEZING SPRAY WATCH FROM SATURDAY EVENING THROUGH MONDAY
EVENING FOR LSZ162-240>244-263-264.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...JLA
SHORT TERM...SRF
LONG TERM...KC
AVIATION...TK
MARINE...SRF/KC
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1234 PM EST FRI JAN 18 2013
.SYNOPSIS...
COLD SURFACE HIGH PRESSURE WILL KEEP HIGH TEMPERATURES IN THE
TEENS ACROSS THE NORTH COUNTRY TODAY. A WARM FRONT WILL BRING
LIGHT SNOW TO THE NORTH COUNTRY LATE TONIGHT INTO SATURDAY MORNING.
SATURDAY WILL BE BREEZY AND MILD WITH HIGH TEMPS REACHING THE
UPPER 30S. ANOTHER FRONTAL SYSTEM BRINGS SNOW SHOWERS TO THE
REGION SATURDAY NIGHT AND SUNDAY ALONG WITH SOME STRONG WINDS.
COLDER TEMPERATURES RETURN FOR MONDAY AND TUESDAY.
&&
.NEAR TERM /UNTIL 7 PM THIS EVENING/...
AS OF 1149 AM EST FRIDAY...CLEAR SKIES IN PLACE ACROSS THE NORTH
COUNTRY JUST BEFORE NOONTIME. SURFACE HIGH PRESSURE RIDGE OVER THE
FORECAST AREA WILL SHIFT EWD INTO NH/MAINE THIS EVENING. 850MB
TEMPS GRADUALLY MODERATING...BUT STILL -20 TO -22C PER RAP GUIDANCE
AT 18Z. MAX TEMPS WILL BE ABOUT 10 DEGREES BELOW NORMAL...ONLY
REACHING INTO THE MID-UPPER TEENS THIS AFTERNOON...WITH A FEW
LOWER 20S IN THE IMMEDIATE CT RIVER VALLEY. CLOUDS WILL BEGIN TO
INCREASE ACROSS NORTHERN NEW YORK THIS EVENING ON SOUTHWEST FLOW
AHEAD OF APPROACHING WARM FRONT.
&&
.SHORT TERM /7 PM THIS EVENING THROUGH SUNDAY/...
AS OF 230 AM EST FRIDAY...THE SHORT TERM FORECAST PERIOD WILL BE
PRETTY ACTIVE WITH TWO DIFFERENT LOW PRESSURE SYSTEMS AFFECTING
THE NORTH COUNTRY. SURFACE HIGH PRESSURE SLIDES EASY AWAY FROM
THE REGION AND WARM FRONT MOVES ACROSS THE AREA TONIGHT BRINGING
CHANCE FOR SOME LIGHT SNOW TO THE NORTH COUNTRY. BEST FORCING
WILL BE ALONG OUR NORTHERN BORDER...WITH 1-3" OF SNOW EXPECTED.
OTHER AREAS WILL ONLY HAVE UP TO 1". LOW PRESSURE SYSTEM MOVES
INTO THE SAINT LAWRENCE VALLEY OVERNIGHT. CLOUDS AND LIGHT SNOW
WILL KEEP TEMPERATURES FROM DROPPING TOO DRASTICALLY
OVERNIGHT...AND OVERNIGHT MIN TEMPS WILL BE CLOSE TO FRIDAY`S MAX
TEMPS. SATURDAY WILL BE MILD...ABOUT TEN DEGREES ABOVE NORMAL AS
WARM AIR ADVECTION CONTINUES ACROSS THE NORTH COUNTRY. WILL STILL
HAVE MENTION FOR SOME LIGHT SNOW DURING THE DAY
SATURDAY...ESPECIALLY EARLIER IN THE DAY AND ACROSS OUR NORTHERN
AND HIGHER ELEVATION ZONES. GUSTY SOUTH-SOUTHWEST WINDS WILL
DEVELOP DURING THE DAY AS THE WARM FRONT LIFTS NORTH OF THE CWA.
SATURDAY NIGHT A SECOND STRONGER LOW PRESSURE SYSTEM WILL
APPROACH...BUT THEN PASS NORTH OF...THE NORTH COUNTRY. WILL HAVE
CHANCE FOR SOME SNOW SHOWERS WITH THIS FRONTAL PASSAGE
SUNDAY...BUT BIGGER CONCERN THEN SNOW WOULD BE STRONG WINDS WITH
TIGHT PRESSURE GRADIENT IN PLACE. MAY SEE ADDITIONAL LIGHT SNOW
ACCUMULATIONS OF 1-3" IN NORTHERN NEW YORK. SATURDAY NIGHT AND
SUNDAY WILL ALSO BOTH BE MILD FOR THIS TIME OF YEAR WITH TEMPS
ONLY DROPPING IN THE UPPER 20S SATURDAY NIGHT DUE TO
WINDS...CLOUD COVER...AND SNOW SHOWERS. ON SUNDAY MAX
TEMPERATURES WILL BE EARLY IN THE DAY HEAD OF THE FRONT...BUT
WILL STILL BE ABOUT 5 DEGREES ABOVE NORMAL WITH LOWER 30S
EXPECTED.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 354 AM EST FRIDAY...NO SIGNIFICANT PRECIPITATION EVENTS EXPECTED
DURING THE EXTENDED PERIOD. THE BIG STORY WILL BE THE ARCTIC CHILL
WITH THE COLDEST AIRMASS OF THE SEASON EXPECTED TO TAKE UP RESIDENCE
OVER THE NORTH COUNTRY. CORE OF THE COLD AIR WILL BE OVER THE AREA
TUESDAY INTO WEDNESDAY WHEN TEMPERATURES WILL AVERAGE AROUND 20
DEGREES BELOW NORMAL.
COLD ADVECTION CONTINUES SUNDAY NIGHT ALONG WITH CHANCE FEW SNOW
SHOWERS IN WAKE OF DEPARTING LOW PRESSURE...WHICH WILL BE MAKING ITS
WAY UP THROUGH CANADIAN MARITIMES. WINDS STILL GUSTY DURING THE
EVENING...THEN EASING OVERNIGHT. WEAK HIGH PRESSURE WILL BUILD IN AT
THE SURFACE MONDAY...BUT UPPER TROUGH WILL REMAIN OVER THE REGION
KEEPING CLOUDS AND SLIGHT CHANCE SNOW SHOWERS OVER THE AREA.
UPPER LEVEL TROUGH WILL DIG SOUTH OF THE FORECAST AREA LATER MONDAY
INTO TUESDAY. SOME INDICATIONS THAT WEAK SURFACE LOW MAY SPIN
UP OVER MID ATLANTIC STATES MONDAY AND THEN TRACK WELL SOUTH OF
NEW ENGLAND MONDAY NIGHT INTO TUESDAY...WITH PRECIP ASSOCIATED
WITH IT REMAINING MOSTLY TO OUR SOUTH. A SERIES OF DISTURBANCES
EMBEDDED IN THE FLOW ALOFT MAY BRING A FEW SNOW SHOWERS OR
FLURRIES TO THE FORECAST AREA AT TIMES...BUT NOTHING OF CONSEQUENCE.
CHANCES FOR SNOW SHOWERS INCREASE LATER THURSDAY AS HIGH PRESSURE
MOVES EAST OF THE AREA AND WARM FRONT APPROACHES FROM THE
SOUTH AND WEST. VERY COLD AIRMASS WILL BE ENTRENCHED OVER THE
REGION FOR THE FIRST HALF OF THE WEEK. 850 MB TEMPS AROUND -20C ON
MONDAY...AND -20C TO AS LOW AS -30C OVER NORTHERN AREAS TUESDAY
INTO WEDNESDAY. THE RESULT WILL BE TEMPERATURES MUCH BELOW NORMAL
MONDAY THROUGH WEDNESDAY WITH HIGHS GENERALLY IN THE SINGLE
NUMBERS AND TEENS...WITH NIGHTTIME READINGS 0 TO 20 BELOW. COLDEST
DAYS LOOKING TO BE TUESDAY AND WEDNESDAY WHEN MANY NORTHERN
LOCALES MAY STRUGGLE TO BREAK ZERO.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
THROUGH 12Z SATURDAY...CLEAR SKIES WILL TREND TO BKN/OVC LATER
THIS EVENING AS HIGH PRESSURE SLIDES EAST OF THE REGION AND MID
LEVEL MOISTURE SPREADS EAST FROM THE GREAT LAKES WITH THE APPROACH
OF A WARM FRONT. CONDITIONS WILL DETERIORATE TO MVFR/IFR FROM WEST
TO EAST ACROSS THE REGION BETWEEN 00Z-06Z SUNDAY IN DEVELOPING
SNOW. MVFR/IFR SNOW CONTINUES THROUGH 12Z...THEN TAPERS OFF AS THE
FRONT SHIFTS NORTH OF THE REGION...EXCEPT FOR ACROSS NORTHERN NEW
YORK WHERE MVFR SNOWS WILL CONTINUE A BIT LONGER. WINDS TREND LIGHT
TO MODERATE SOUTH/SOUTHWESTERLY THIS AFTERNOON/NIGHT AND BECOME GUSTY
TO 20 KTS AFTER 12Z SATURDAY.
OUTLOOK 18Z SATURDAY THROUGH WEDNESDAY...
18Z SATURDAY THROUGH 06Z SUNDAY...A MIX OF VFR/MVFR WITH SNOW
SHOWERS IN THE VICINITY LOWERING CONDITIONS TO MVFR/IFR AT TIMES.
06Z SUNDAY THROUGH 00Z MONDAY...MVFR/IFR AT TIMES IN SNOW SHOWERS ASSOCIATED
WITH ARCTIC FRONT. WIND GUSTS FROM WEST-SOUTHWEST OF 30-40 KTS POSSIBLE.
00Z MONDAY ONWARD...IMPROVING TO VFR UNDER HIGH PRESSURE.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...NEILES
NEAR TERM...BANACOS/NEILES
SHORT TERM...NEILES
LONG TERM...RJS
AVIATION...LAHIFF
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1155 AM EST FRI JAN 18 2013
.SYNOPSIS...
COLD SURFACE HIGH PRESSURE WILL KEEP HIGH TEMPERATURES IN THE
TEENS ACROSS THE NORTH COUNTRY TODAY. A WARM FRONT WILL BRING
LIGHT SNOW TO THE NORTH COUNTRY LATE TONIGHT INTO SATURDAY MORNING.
SATURDAY WILL BE BREEZY AND MILD WITH HIGH TEMPS REACHING THE
UPPER 30S. ANOTHER FRONTAL SYSTEM BRINGS SNOW SHOWERS TO THE
REGION SATURDAY NIGHT AND SUNDAY ALONG WITH SOME STRONG WINDS.
COLDER TEMPERATURES RETURN FOR MONDAY AND TUESDAY.
&&
.NEAR TERM /UNTIL 7 PM THIS EVENING/...
AS OF 1149 AM EST FRIDAY...CLEAR SKIES IN PLACE ACROSS THE NORTH
COUNTRY JUST BEFORE NOONTIME. SURFACE HIGH PRESSURE RIDGE OVER THE
FORECAST AREA WILL SHIFT EWD INTO NH/MAINE THIS EVENING. 850MB
TEMPS GRADUALLY MODERATING...BUT STILL -20 TO -22C PER RAP GUIDANCE
AT 18Z. MAX TEMPS WILL BE ABOUT 10 DEGREES BELOW NORMAL...ONLY
REACHING INTO THE MID-UPPER TEENS THIS AFTERNOON...WITH A FEW
LOWER 20S IN THE IMMEDIATE CT RIVER VALLEY. CLOUDS WILL BEGIN TO
INCREASE ACROSS NORTHERN NEW YORK THIS EVENING ON SOUTHWEST FLOW
AHEAD OF APPROACHING WARM FRONT.
&&
.SHORT TERM /7 PM THIS EVENING THROUGH SUNDAY/...
AS OF 230 AM EST FRIDAY...THE SHORT TERM FORECAST PERIOD WILL BE
PRETTY ACTIVE WITH TWO DIFFERENT LOW PRESSURE SYSTEMS AFFECTING
THE NORTH COUNTRY. SURFACE HIGH PRESSURE SLIDES EASY AWAY FROM
THE REGION AND WARM FRONT MOVES ACROSS THE AREA TONIGHT BRINGING
CHANCE FOR SOME LIGHT SNOW TO THE NORTH COUNTRY. BEST FORCING
WILL BE ALONG OUR NORTHERN BORDER...WITH 1-3" OF SNOW EXPECTED.
OTHER AREAS WILL ONLY HAVE UP TO 1". LOW PRESSURE SYSTEM MOVES
INTO THE SAINT LAWRENCE VALLEY OVERNIGHT. CLOUDS AND LIGHT SNOW
WILL KEEP TEMPERATURES FROM DROPPING TOO DRASTICALLY
OVERNIGHT...AND OVERNIGHT MIN TEMPS WILL BE CLOSE TO FRIDAY`S MAX
TEMPS. SATURDAY WILL BE MILD...ABOUT TEN DEGREES ABOVE NORMAL AS
WARM AIR ADVECTION CONTINUES ACROSS THE NORTH COUNTRY. WILL STILL
HAVE MENTION FOR SOME LIGHT SNOW DURING THE DAY
SATURDAY...ESPECIALLY EARLIER IN THE DAY AND ACROSS OUR NORTHERN
AND HIGHER ELEVATION ZONES. GUSTY SOUTH-SOUTHWEST WINDS WILL
DEVELOP DURING THE DAY AS THE WARM FRONT LIFTS NORTH OF THE CWA.
SATURDAY NIGHT A SECOND STRONGER LOW PRESSURE SYSTEM WILL
APPROACH...BUT THEN PASS NORTH OF...THE NORTH COUNTRY. WILL HAVE
CHANCE FOR SOME SNOW SHOWERS WITH THIS FRONTAL PASSAGE
SUNDAY...BUT BIGGER CONCERN THEN SNOW WOULD BE STRONG WINDS WITH
TIGHT PRESSURE GRADIENT IN PLACE. MAY SEE ADDITIONAL LIGHT SNOW
ACCUMULATIONS OF 1-3" IN NORTHERN NEW YORK. SATURDAY NIGHT AND
SUNDAY WILL ALSO BOTH BE MILD FOR THIS TIME OF YEAR WITH TEMPS
ONLY DROPPING IN THE UPPER 20S SATURDAY NIGHT DUE TO
WINDS...CLOUD COVER...AND SNOW SHOWERS. ON SUNDAY MAX
TEMPERATURES WILL BE EARLY IN THE DAY HEAD OF THE FRONT...BUT
WILL STILL BE ABOUT 5 DEGREES ABOVE NORMAL WITH LOWER 30S
EXPECTED.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 354 AM EST FRIDAY...NO SIGNIFICANT PRECIPITATION EVENTS EXPECTED
DURING THE EXTENDED PERIOD. THE BIG STORY WILL BE THE ARCTIC CHILL
WITH THE COLDEST AIRMASS OF THE SEASON EXPECTED TO TAKE UP RESIDENCE
OVER THE NORTH COUNTRY. CORE OF THE COLD AIR WILL BE OVER THE AREA
TUESDAY INTO WEDNESDAY WHEN TEMPERATURES WILL AVERAGE AROUND 20
DEGREES BELOW NORMAL.
COLD ADVECTION CONTINUES SUNDAY NIGHT ALONG WITH CHANCE FEW SNOW
SHOWERS IN WAKE OF DEPARTING LOW PRESSURE...WHICH WILL BE MAKING ITS
WAY UP THROUGH CANADIAN MARITIMES. WINDS STILL GUSTY DURING THE
EVENING...THEN EASING OVERNIGHT. WEAK HIGH PRESSURE WILL BUILD IN AT
THE SURFACE MONDAY...BUT UPPER TROUGH WILL REMAIN OVER THE REGION
KEEPING CLOUDS AND SLIGHT CHANCE SNOW SHOWERS OVER THE AREA.
UPPER LEVEL TROUGH WILL DIG SOUTH OF THE FORECAST AREA LATER MONDAY
INTO TUESDAY. SOME INDICATIONS THAT WEAK SURFACE LOW MAY SPIN
UP OVER MID ATLANTIC STATES MONDAY AND THEN TRACK WELL SOUTH OF
NEW ENGLAND MONDAY NIGHT INTO TUESDAY...WITH PRECIP ASSOCIATED
WITH IT REMAINING MOSTLY TO OUR SOUTH. A SERIES OF DISTURBANCES
EMBEDDED IN THE FLOW ALOFT MAY BRING A FEW SNOW SHOWERS OR
FLURRIES TO THE FORECAST AREA AT TIMES...BUT NOTHING OF CONSEQUENCE.
CHANCES FOR SNOW SHOWERS INCREASE LATER THURSDAY AS HIGH PRESSURE
MOVES EAST OF THE AREA AND WARM FRONT APPROACHES FROM THE
SOUTH AND WEST. VERY COLD AIRMASS WILL BE ENTRENCHED OVER THE
REGION FOR THE FIRST HALF OF THE WEEK. 850 MB TEMPS AROUND -20C ON
MONDAY...AND -20C TO AS LOW AS -30C OVER NORTHERN AREAS TUESDAY
INTO WEDNESDAY. THE RESULT WILL BE TEMPERATURES MUCH BELOW NORMAL
MONDAY THROUGH WEDNESDAY WITH HIGHS GENERALLY IN THE SINGLE
NUMBERS AND TEENS...WITH NIGHTTIME READINGS 0 TO 20 BELOW. COLDEST
DAYS LOOKING TO BE TUESDAY AND WEDNESDAY WHEN MANY NORTHERN
LOCALES MAY STRUGGLE TO BREAK ZERO.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
THROUGH 12Z SATURDAY...VFR CONDITIONS TODAY WITH HIGH PRESSURE
OVER THE REGION. SKIES TREND BKN/OVC LATER THIS AFTERNOON AS HIGH
SLIDES EAST AND MID LEVEL MOISTURE SPREADS EAST FROM THE GREAT
LAKES WITH APPROACH OF WARM FRONT. CONDITIONS WILL DETERIORATE TO
MVFR/IFR FROM WEST TO EAST ACROSS THE REGION BETWEEN 00Z-06Z
SUNDAY IN DEVELOPING SNOW. WINDS TRENDING LIGHT TO MODERATE
SOUTH/SOUTHWESTERLY THIS AFTERNOON/NIGHT AND OCCASIONALLY GUSTY
TO 20 KTS AT NRN NY TERMINALS AFTER 18Z AND IN CHAMPLAIN VALLEY
LATER FRIDAY NIGHT.
OUTLOOK 12Z SATURDAY THROUGH TUESDAY...
12Z SATURDAY THROUGH 06Z SUNDAY...LOWERING TO MVFR/IFR AT TIMES
IN SNOW SHOWERS ASSOCIATED WITH WARM FRONT.
06Z SUNDAY THROUGH 06Z MONDAY...MVFR/IFR AT TIMES IN SNOW SHOWERS ASSOCIATED
WITH ARCTIC FRONT. WIND GUSTS FROM WEST-SOUTHWEST OF 30-40 KTS POSSIBLE.
06Z MONDAY ONWARD...IMPROVING TO VFR.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...NEILES
NEAR TERM...BANACOS/NEILES
SHORT TERM...NEILES
LONG TERM...RJS
AVIATION...RJS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1142 AM CST FRI JAN 18 2013
.SHORT TERM...TODAY THROUGH SUNDAY NIGHT
314 AM CST FRI JAN 18 2013
THE MAIN FOCUS THROUGH THE WEEKEND IS WITH PRECIPITATION CHANCES
ALONG WITH THE TEMPERATURE DROP AND STRONG WINDS BEHIND THE FIRST
IN A SERIES OF COLD FRONTS THAT WILL MOVE THROUGH THE REGION.
CURRENTLY...A BAND OF SNOW EXTENDS FROM CENTRAL MINNESOTA DOWN
INTO SOUTHWEST WISCONSIN AHEAD OF A SURFACE WARM FRONT AND WILL
QUICKLY PROPAGATE TO THE EAST THIS MORNING. SOME OF THIS SNOW HAS
TAKEN ON A CONVECTIVE LOOK TO IT ACROSS CENTRAL MINNESOTA...LIKELY
DUE TO THE LOW LEVEL FRONTOGENESIS BEING SHOWN THERE ON 18.06Z RAP
CROSS SECTIONS...WITH SOME VISIBILITIES DROPPING DOWN TO A MILE AT
TIMES. THIS SNOW WILL BE OUT OF THE FORECAST AREA QUICKLY THIS
MORNING WITH SNOW TOTALS STILL LOOKS TO BE AROUND AN INCH OR TWO
IN NORTH CENTRAL WISCONSIN WITH LESS THAN AN INCH SOUTH OF CLARK
COUNTY WISCONSIN. CONFIDENCE NOT VERY HIGH THAT FREEZING DRIZZLE
WILL OCCUR AS THERE HAS BEEN LITTLE IN REPORTS OF IT ALONG THE
BACK EDGE OF THE SNOW. 18.06Z RAP SOUNDINGS SHOW THAT IF THERE IS
AN AREA WHERE THE FREEZING DRIZZLE IS POSSIBLE...IT MAY BE ACROSS
NORTH CENTRAL WISCONSIN WHERE THE COLUMN MAY LOSE ICE WITH LOW
LEVEL LIFT STILL STRONG. CEILINGS HAVE NOT BEEN VERY LOW
THOUGH...MAINLY ABOVE 2KFT...SO THINK THAT THE LOW LEVEL RH MAY BE
A LITTLE OVERDONE. WILL LEAVE THE FZDZ MENTION IN THE FORECAST FOR
NOW...BUT HAVE TRIMMED IT BACK TO JUST BEING POSSIBLE IN WEST
CENTRAL WISCONSIN...MAINLY ALONG AND NORTH OF I-94.
THE NEXT QUESTION IS WITH TEMPERATURES TODAY WITH MUCH OF THE
REGION BEING IN THE WARM SECTOR AS A WARM FRONT LIFTS NORTHEAST OF
THE REGION. THOUGH 850MB TEMPERATURES ARE ONLY AROUND 1 STANDARD
DEVIATION ABOVE THE NORM...HIGHS MAY COME CLOSE TO A RECORD AT
RST WHERE THE PREVIOUS RECORD IS 46. WITH JUST MID TO UPPER LEVEL
CLOUD COVER TO CONTEND WITH...AND LITTLE TO NO SNOW ON THE
GROUND...TEMPERATURES SHOULD CLIMB INTO THE 40S ACROSS MUCH OF THE
REGION. THE ECMWF HAS BEEN OUR BEST VERIFYING GUIDANCE WITH THE
RECENT WARM DAYS...SO HAVE FOLLOWED IT WITH THE TRENDS FOR TODAY.
THE HAMMER DROPS SATURDAY AS THE FIRST COLD FRONT COMES THROUGH IN
THE AFTERNOON WITH A SECONDARY ONE COMING THROUGH IN THE EVENING
THAT WILL BRING DOWN THE MUCH COLDER AIR AND STRONG/GUSTY WINDS.
THE STRONG COLD AIR ADVECTION AND TIGHT PRESSURE GRADIENT WILL
LEAD TO WIND GUSTS UP INTO THE 40MPH RANGE SATURDAY EVENING RIGHT
AFTER FROPA. THIS COMBINATION OF DROPPING TEMPERATURES AND GUSTY
WINDS COULD LEAD TO THE WIND CHILL DROPPING INTO THE -20F TO -25F
RANGE ACROSS SOUTHEAST MINNESOTA AND WESTERN WISCONSIN TO WHERE A
WIND CHILL ADVISORY MAY BE NEEDED. BUMPED UP CLOUD COVER A BIT
AND ADDED SOME FLURRIES BEHIND THE COLD FRONT AS 18.00Z NAM/GFS
SOUNDINGS SHOW SOME LOW LEVEL RH DROPPING INTO THE -10C TO -20C
RANGE.
ANOTHER WEAKLY FORCED SYSTEM WILL MOVE THROUGH IOWA ON SUNDAY AND
BRING ANOTHER POSSIBLE ROUND OF LIGHT SNOW ALONG WITH IT. WITH A
RIDGE OF HIGH PRESSURE PUSHING DOWN FROM THE NORTHWEST THOUGH...IT
WILL BE HARD TO SQUEEZE OUT MUCH IN THE WAY OF PRECIPITATION.
.LONG TERM...MONDAY THROUGH THURSDAY
314 AM CST FRI JAN 18 2013
THE MAIN FOCUS INTO NEXT WEEK IS WITH THE TEMPERATURES AND HOW LOW
THEY WILL GO. THE LACK OF SNOW ON THE GROUND WILL HELP TO KEEP
TEMPERATURES UP ABOUT 10 DEGREES FROM WHERE THEY NORMALLY COULD
DROP TO...BUT EVEN SO LOWS WILL DROP WELL BELOW ZERO MONDAY
MORNING AND TUESDAY MORNING. THE 18.00Z GEM IS THE COLDEST OF THE
MODEL RUNS WITH HAVING 850MB TEMPERATURES DROPPING DOWN TO -32C BY
MONDAY AFTERNOON...BUT THAT APPEARS TO BE A BIT EXTREME COMPARED
TO THE 18.00Z GFS/ECMWF WHICH HAVE 850MB TEMPERATURES AROUND -24C
AT THAT SAME TIME. WIND CHILL ADVISORIES WILL LIKELY BE NEEDED
MONDAY AND TUESDAY WITH WIND CHILLS DROPPING DOWN INTO THE -20F TO
-30F RANGE. THE SURFACE RIDGE AXIS PASSES BY ON WEDNESDAY MORNING
WITH WARMER LOW LEVEL AIR MOVING BACK IN THROUGH THE REST OF THE
WEEK. THE 18.00Z GFS/ECMWF CONTINUE TO HINT AT A LATE WEEK SYSTEM
MOVING THROUGH THE REGION...BUT THERE IS CONSIDERABLE SPREAD ON
WHERE THIS SYSTEM WILL TRACK.
&&
.AVIATION...THROUGH 18Z SATURDAY
1142 AM CST FRI JAN 18 2013
A WARM FRONT HAS LIFTED THROUGH THE TAF SITES...RESULTING IN A
BREEZY SOUTH TO SOUTHWEST WIND. BOTH TAF SITES SHOULD STAY FAIRLY
STEADY WITH THE SUSTAINED WINDS AND GUSTS THROUGH THE
AFTERNOON...BETWEEN 10-20 KT ON SUSTAINED WINDS AND 20-25 KT ON
GUSTS. EXPECT THE WINDS AND GUSTS TO DIMINISH QUICKLY AROUND
SUNSET WITH LOSS OF HEATING. PLENTY OF LOW LEVEL DRY AIR SHOULD
KEEP CONDITIONS VFR...UP TO THE ARRIVAL OF AN ARCTIC FRONT
CURRENTLY IN SOUTHERN ALBERTA. THIS FRONT SHOULD BEGIN TO APPROACH
THE TAF SITES NEAR 18Z SATURDAY. AHEAD OF THE FRONT...WINDS WILL
BEGIN TO TURN WESTERLY...AND THIS IS NOTED IN THE TAFS.
LOOKING AHEAD...EXPECT THE ARCTIC FRONT TO CROSS THE TAF SITES
AROUND 21Z SATURDAY. WINDS IMMEDIATELY AFTER PASSAGE WILL BE QUITE
STRONG...SUSTAINED LIKELY BETWEEN 20-30 KT WITH GUSTS OF
30-40KT...HIGHEST AT KRST. IN ADDITION...AN MVFR CLOUD DECK LOOKS
TO FOLLOW IN THE WAKE OF THE FRONT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
314 AM CST FRI JAN 18 2013
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...AJ