Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 01/07/13
AREA FORECAST DISCUSSION
NWS PUEBLO CO
249 PM MST SAT JAN 5 2013
.SHORT TERM...
(TONIGHT AND SUNDAY)
SHORTWAVE PASSING OFF TO THE NORTHEAST HAS SENT A DRY COLD FRONT
THROUGH THE SE PLAINS. WINDS NOT TERRIBLY STRONG WITH IT...AND
MIXING HAS ACTUALLY WARMED TEMPS A FEW DEGREES IN SPITE OF THE CAA
BEHIND THE FRONT...WITH KLAA AT 45 DEGREES SO FAR...COMPARED TO
YESTERDAY`S HIGH OF ONLY 39. MEANWHILE...THE SAN LUIS VALLEY HAS
BEEN STRUGGLING TO WARM...WITH KALS ONLY AT 11 DEGREES AS OF 21Z.
TONIGHT...CLEAR SKIES...DRY SFC DEW POINTS...AND SNOW COVER IN SOME
PLACES WILL LEAD TO ANOTHER COLD NIGHT. CAN`T FIND A REASON WHY
KALS WON`T DROP TO AROUND -30 AGAIN TONIGHT...SO TOOK MIN TEMPS
THERE WELL BELOW GUIDANCE. OTHER CHALLENGE WILL BE POTENTIAL FOR
FOG IN THE SAN LUIS VALLEY. THIS DIDN`T HAPPEN LAST NIGHT...OR AT
LEAST VISIBILITY AT KALS DIDN`T DROP BELOW 5 MILES...THOUGH WE DID
SEE SOME LIFR STRATUS IN THE WEB CAMS AND IN THE CEILOMETER DATA FROM
ASOS. NAM12 SOUNDINGS SATURATE AT THE SFC AROUND 02Z AND REMAIN SO
THROUGH 15Z SUN. THE LOCAL 4 KM WRF ALSO INDICATES POTENTIAL FOR
FOG...AND HRRR SHOWS SFC RHS APPROACHING 80% BY 09Z SUN. RAP
SOUNDINGS BY CONTRAST LOOK FAIRLY DRY...AND NEITHER THE MET NOR MAV
GUIDANCE HAVE ANY INDICATION OF FOG. WILL THROW PATCHY FOG INTO THE
GRIDS FOR NOW...BUT WILL DELAY THIS UNTIL AFTER 06Z. HUNCH IS IT
WON`T OCCUR UNTIL AFTER 09-10Z BASED ON WHAT HAPPENED LAST
NIGHT...AND SHOULD BREAK BY 15-16Z ON SUN.
FLOW ALOFT BECOMES MORE SOUTHWESTERLY ON SUNDAY AS THE UPPER RIDGE
SHIFTS EASTWARD AND NEXT UPPER LOW MOVES INTO CA. LEE TROF
DEEPENS IN RESPONSE WITH WINDS AIDING IN BETTER MIXING ALONG THE
I-25 CORRIDOR. CURRENT FORECAST WITH 40S AND LOWER 50S LOOK
REASONABLE ACROSS THE PLAINS. MEANWHILE...DRY CONDITIONS WILL
CONTINUE EVERYWHERE. ITS POSSIBLE THAT KALS COULD SEE SOME
MODERATING TEMPERATURES AS WELL IF WINDS CAN MIX IN...BUT GIVEN THE
STRONG INVERSIONS...KEPT TEMPS BELOW GUIDANCE VALUES WITH SOME MINOR
IMPROVEMENT. -KT
.LONG TERM...
(SUNDAY NIGHT-SATURDAY)
SUNDAY NIGHT-MONDAY...LATEST MODELS CONTINUE TO BE IN GOOD AGREEMENT
OF DEVELOPING SPLIT FLOW PATTERN INTO THE MIDDLE WEEK. CLOSED LOW IN
THE DEVELOPING SOUTHERN STREAM ACROSS THE SOUTHEASTERN NEVADA SUNDAY
AFTERNOON PROGGED TO DIVE INTO OLD MEXICO THROUGH THE DAY MONDAY AS
A MINOR WAVE EMBEDDED IN THE ZONAL FLOW ACROSS NORTHERN TIER OF
STATES TRANSLATES ACROSS THE NORTHERN ROCKIES AND INTO THE NORTHERN
HIGH PLAINS. OVERNIGHT LOWS...ESPECIALLY IN THE SAN LUIS VALLEY
REMAIN TRICKY WITH SOME INCREASE IN HIGH LEVEL MOISTURE SPREADING
ACROSS THE REGION...THOUGH DOES NOT LOOK TO BE ENOUGH TO KEEP TEMPS
FROM TANKING...AND HAVE GONE BELOW GUIDANCE VALUES IN THE HIGH MT
VALLEYS. BOTH SYSTEMS REMAIN TOO FAR AWAY FROM THE AREA TO PRODUCE
ANY PRECIPITATION...THOUGH WILL SEE SLIGHTLY COOLER TEMPERATURES
AS PASSING NORTHERN STREAM SYSTEM SENDS A WEAK BACKDOOR COLD FRONT
ACROSS EASTERN COLORADO MONDAY MORNING.
MONDAY NIGHT-WEDNESDAY NIGHT...WEAK FLOW PROGGED ACROSS THE AREA
THROUGH THIS PERIOD AS OLD MEXICO LOW SLOWLY LIFTS OUT INTO THE
SOUTHERN HIGH PLAINS. MODELS DIFFER ON TRACK WITH THE EC A TAD
FURTHER NORTH AND WEST WITH SAID SYSTEM ACROSS THE NORTH CENTRAL
TEXAS PANHANDLE WEDNESDAY NIGHT AND PRINTS OUT SOME LIGHT QPF
ACROSS THE FAR SE PLAINS. WITH THE WEAK FLOW ALOFT...HAVE GONE BELOW
GUIDANCE FOR HIGHS THROUGH THE PERIOD...WITH TEMPERATURES MAINLY IN
THE 40S TO LOWER 50S ACROSS THE PLAINS AND 30S ACROSS THE HIGHER
TERRAIN. AGAIN...HAVE STAYED WELL BELOW GUIDANCE FOR THE SAN LUIS
VALLEY AS NOT ENOUGH WIND TO SCOUR OUT THE COLD AIRMASS IN PLACE.
THURSDAY-SATURDAY...LATEST MODELS CONTINUE TO INDICATE A BETTER
CHANCE OF WIDESPREAD PRECIPITATION INTO THE EARLY WEEKEND AS PACIFIC
ENERGY DIGGING INTO THE GREAT BASIN ON THURSDAY SLOWLY LIFTS OUT
ACROSS THE ROCKIES THROUGH SATURDAY. SOME CONCERN THAT STRONG
BACKSIDE JET ACROSS THE GREAT BASIN COULD DIG THE SYSTEM FURTHER
SOUTH THAN CURRENT PROJECTIONS...SO HAVE KEPT CURRENT MODEL
CONSENSUS SOLUTION WHICH GIVES CHANCE POPS ACROSS THE CONTINENTAL
DIVIDE THURSDAY NIGHT AND FRIDAY...WITH CHANCE AND SLIGHT CHANCE
POPS SPREADING ACROSS THE REST OF THE HIGHER TERRAIN THROUGH THE
EASTERN PLAINS FRIDAY THROUGH SATURDAY. TEMPERATURES WILL ALSO BE
TRENDING BACK BELOW SEASONAL AVERAGES BY FRIDAY AND SATURDAY. -MW
&&
.AVIATION...
CLEAR SKIES AND VFR CONDITIONS EXPECTED AT KPUB AND KCOS THROUGH
SUNDAY. CHALLENGE WILL BE THE POTENTIAL FOR LIFR CIGS AND POSSIBLY
VIS IN FZFG AT KALS OVERNIGHT. MODELS DIFFER IN WHETHER THIS WILL
OR WILL NOT OCCUR...AND CONFIDENCE IS LOW. PLAN TO DELAY LIFR
CONDITIONS UNTIL AFTER 09Z IN NEXT TAF ISSUANCE. ANY LIFR CIGS/VIS
SHOULD BREAK BETWEEN 15-16Z...WITH VFR CONDITIONS AND LIGHT WINDS
THROUGH SUNDAY. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
31/23
AREA FORECAST DISCUSSION
NWS ALBANY NY
1245 PM EST SUN JAN 6 2013
.SYNOPSIS...
LOW PRESSURE AND ITS ASSOCIATED COLD FRONT TRACKING EAST FROM THE
GREAT LAKES REGION WILL MOVE ACROSS EASTERN NEW YORK AND WESTERN NEW
ENGLAND LATE TONIGHT. THIS COULD BRING SOME LIGHT SNOW OR SNOW
SHOWERS...WITH THE BEST CHANCE FOR ACCUMULATIONS IN THE HIGHER
TERRAIN...MAINLY NORTHWEST OF ALBANY. DRIER AND MILDER WEATHER IS
EXPECTED AS WE MOVE AHEAD INTO THE UPCOMING WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1230 AM...FIRST I HAVE TO COMMEND THE PREVIOUS FORECASTERS ON
THEIR HOURLY CLOUD COVER GRIDS. PER SATELLITE PICTURES...THE GRID
FORECAST WAS NEARLY RIGHT ON! GOOD JOB!
ONLY MINOR TWEAKING ON THIS UPDATE...MAINLY TO TRIM BACK THE SNOW
SHOWERS. RADAR DOES INDICATE ANOTHER ROUND BEGINNING TO TRICKLE INTO
OUR WESTERN AREAS. MOST MODELS KEEP ANY MEASURABLE SNOW SHOWERS
ACROSS THE HIGHER ELEVATIONS. THE EXPERIMENTAL HRRR DOES INDICATE
SOME RETURNS AROUND 15 DBZ...MAINLY JUST NORTH OF THE MOHAWK
RIVER.
FOR NOW...KEEP MEASURABLE POPS NORTH AND WEST (EAST TOO) OF ALBANY
PROPER AND EVEN IN THOSE OTHER AREAS LOOKING AT MANY FLURRIES WITH A
BURST OF SLIGHTLY HEAVIER SNOW SHOWERS. THE ONLY ACCUMULATION SNOWS
LOOK TO BE ACROSS THE DACKS AND PERHAPS SOUTHERN GREENS WHERE UP TO
AN INCH COULD ACCUMULATE. ELSEWHERE...ANY PRECIPITATION THAT FALLS
MIGHT BE LIGHT ENOUGH AND COMBINED WITH SURFACE TEMPERATURES ABOVE
FREEZING TO EVEN FALL AS LIGHT RAIN SHOWERS (REALLY SPRINKLES).
EITHER WAY...NOT A BIG DEAL.
OTHERWISE...IT WILL REMAIN RATHER CLOUDS NORTH OF ALBANY...SUNSHINE
FADING BEHIND INCREASING CLOUDS SOUTH OF ALBANY. RIGHT IN THE
CAPITAL DISTRICT LOOKING FOR MORE CLOUDS THAN SUNSHINE BUT A FEW
BREAKS AS WE ARE GETTING RIGHT NOW.
ON GOING HIGH TEMPERATURES LOOK MOSTLY IN THE BALL PARK. DID TWEAK A
FEW PLACES UPWARD...BUT OVERALL IN PRETTY GOOD SHAPE. LOOK FOR HIGH
TEMPERATURES THIS AFTERNOON IN THE LOWER 40S MID HUDSON VALLEY AND
LOWER LITCHFIELD COUNTY...35-40 MOST OTHER VALLEY LOCATIONS...MID
20S TO LOWER 30S.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
IN THE WAKE OF THE LOW DEPARTURE...A LARGE HIGH PRESSURE SYSTEM
WILL TAKER CONTROL OF OUR WEATHER FOR MONDAY INTO TUESDAY.
THIS WILL NOT BE A VERY COLD AIRMASS SO TEMPS WILL BE NEAR OR
ABOVE NORMAL DURING THAT TIME. MAINLY CLEAR SKIES WILL ACCOMPANY
THIS HIGH PRESSURE CENTER TOO...
FOR TEMPS...HIGHS MONDAY TO BE AROUND 20 FOR THE DACKS TO MID
30S FOR THE MID HUDSON VALLEY...AND LOWS MONDAY NIGHT IN THE UPPER
SINGLE NUMBERS AND TEENS AS CLEAR SKIES AND LIGHT WINDS ALLOW FOR
GOOD RADIATIONAL COOLING. HIGHS ON TUESDAY CLIMB BACK INTO THE MID
30S FOR THE TERRAIN TO SOME LOWER 40S FOR THE MID HUDSON VALLEY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THE WEATHER WILL BEGIN RATHER QUIET TO START THE EXTENDED
PERIOD...AS HIGH PRESSURE REMAINS ANCHORED TO THE SOUTH AND WEST OF
THE REGION. TEMPS WILL BE SEASONABLE FOR TUESDAY NIGHT WITH TEENS
AND 20S FOR MOST AREAS. A SW FLOW AT PLACE IN THE LOW AND MID LEVELS
WILL ALLOW FOR MILDER AIR FOR WEDNESDAY WITH MID 30S TO MID 40S
ACROSS THE REGION.
A FAST MOVING NORTHERN STREAM SHORTWAVE WILL SLIDE BY TO THE NORTH
OF THE REGION ACROSS SOUTHERN CANADA FOR WED INTO WED NIGHT. THIS
MAY ALLOW FOR A FEW -SHSN FOR THE ADIRONDACKS...OTHERWISE IT WILL
REMAIN DRY. THIS SYSTEM MAY BRING A GLANCING SHOT OF COOLER AIR TO
THE REGION...AS TEMPS WILL BE A FEW DEGREES COOLER FOR THURSDAY
ACROSS THE AREA WITH CONTINUED DRY CONDITIONS.
A SLOW MOVING CUTOFF SYSTEM WILL EJECT OUT OF THE SOUTHERN PLAINS
TOWARDS THE NORTHEAST FOR THE LATE WEEK PERIOD. WITH THIS SYSTEM...A
SURGE OF WARMER AIR WILL ALLOW FOR MUCH ABOVE NORMAL TEMPS...AND
PRECIP WITH THIS SYSTEM WILL MAINLY FALL IN THE FORM OF RAIN
SHOWERS. HOWEVER...THE MODELS DISAGREE WITH THE EXACT SOLUTION FOR
THE LATTER PORTION OF THE WEEK...WHICH IS TYPICAL WHEN DEALING WITH
A CUTOFF 500 HPA LOW AND A SPLIT FLOW PATTERN. THE 00Z ECMWF IS MUCH
SLOWER BRINGING ANY SYSTEMS INTO THE AREA THAN THE 00Z GFS. THE 00Z
GGEM IS SIMILAR TO THE ECMWF. THE 00Z GEFS MEMBERS CONTINUE TO SHOW
VARIABILITY REGARDING TIMING/QPF TO THE REGION AS WELL. FOR NOW...WE
WILL TAKE A COMPROMISE AND CONTINUE TO SHOW SLIGHT CHC/LOW CHC POPS
FOR THURSDAY NIGHT...AND CHC POPS FOR FRI/FRI NIGHT...AND SLIGHT CHC
POPS INTO SATURDAY. HOWEVER...THIS IS WITH LOW CONFIDENCE...AS THE
GROWING MODEL CONSENSUS BETWEEN THE ECMWF/GGEM MAY SUGGEST THAT IT
REMAINS DRY EVEN INTO FRIDAY AS WELL...WITH PRECIP ARRIVING FOR FRI
NIGHT INTO THE WEEKEND. WE WILL CONTINUE TO SHOW MAX TEMPS REACHING
THE 40S FOR MOST AREAS FOR FRIDAY AND SATURDAY...WHICH IS ABOUT 10
DEGREES ABOVE NORMAL FOR THIS TIME OF YEAR. MIN TEMPS WILL DEPEND ON
THE EXACT TIMING OF THE PRECIP...BUT LOWS WILL ONLY DROP TO THE 20S
AND 30S...WITH SOME AREAS POSSIBLY NOT FALLING BELOW FREEZING EVEN
AT NIGHT.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
THE WEAK SURFACE LOW WILL MOVE ACROSS NORTHERN NEW YORK AND NORTHERN
NEW ENGLAND THIS EVENING. MOISTURE WRAPPING AROUND THE BACK SIDE OF
THIS SYSTEM WILL KEEP CLOUDS OVER THE KGFL/KALB/KPSF TAF SITES
THROUGH TONIGHT (BUT THERE WILL BE BREAKS IN THE CLOUDS FOR THE REST
OF THE AFTN AT KALB/KPSF). AT KPOU EXPECT JUST SCT CLOUDS FOR THE
REST OF THE AFTN. AS THE MOISTURE INCREASE THIS EVENING...THESE IS A
CHANCE OF SNOW SHOWERS AT KGFL/KALB/KPSF...BUT THE THREAT IS LOW
ENOUGH TO ONLY FORECAST VCSH IN THE TAFS. NO PCPN EXPECTED AT KPOU.
BETWEEN 05Z AND 08Z A COLD FRONT WILL MOVE FROM NORTH TO SOUTH
ACROSS THE TAF SITES. THEN HIGH PRESSURE WILL BUILD IN FOR
MONDAY.
MAINLY MVFR CIGS ARE FORECSAT AT KGFL THROUGH TONIGHT. MVFR/VFR CIGS
AT KPSF...AND VFR CIGS AT KALB/KPOU. VSBYS ARE FORECAST TO BE VFR AT
ALL THE SITES. AFTER SUNRISE ON MONDAY...EXPECT CLOUDS TO DECREASE
TO SCT WITH VFR CONDITIONS PREVAILING THROUGH THE END OF THE TAF
PERIOD.
SURFACE WINDS WILL BE SOUTH TO SOUTHWEST AT 5 TO 10 KTS AT ALL THE
TAF SITES UNTIL THE FRONTAL PASSAGE...THEN NORTHWEST TO NORTH AT 5
TO 15 KTS BEHIND THE FRONT.
OUTLOOK...
MON AFTN-WED MRNG...VFR. NO SIG WX.
WED AFTN-WED NITE...VFR/MVFR. CHC -RASN.
THU...VFR. NO SIG WX.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE EXPECTED THE NEXT 5 DAYS RELATED TO QPF...AS
MAINLY DRY WEATHER OR SNOW PRODUCING SYSTEMS WILL IMPACT THE ALBANY
HYDRO SERVICE AREA /HSA/. MOST OF THESE WILL BE RATHER LIGHT.
SOME RIVER GAGES ARE EXHIBITING SIGNS OF ICE EFFECTS...AND RIVER
LEVEL READINGS LOOK UNREPRESENTATIVE. ICE WILL CONTINUE TO FORM
AND THICKEN ON ALL WATERWAYS IN THE ALY HSA THROUGH THE WEEKEND.
WE WILL HAVE TO MONITOR FOR ANY FREEZE UP JAMS...ESPECIALLY ALONG
THE NRN PERIPHERY OF THE HSA.
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...BGM
NEAR TERM...HWJIV
SHORT TERM...BGM
LONG TERM...FRUGIS
AVIATION...GJM
HYDROLOGY...GJM/BGM
AREA FORECAST DISCUSSION
NWS ALBANY NY
1235 PM EST SUN JAN 6 2013
.SYNOPSIS...
LOW PRESSURE AND ITS ASSOCIATED COLD FRONT TRACKING EAST FROM THE
GREAT LAKES REGION WILL MOVE ACROSS EASTERN NEW YORK AND WESTERN NEW
ENGLAND LATE TONIGHT. THIS COULD BRING SOME LIGHT SNOW OR SNOW
SHOWERS...WITH THE BEST CHANCE FOR ACCUMULATIONS IN THE HIGHER
TERRAIN...MAINLY NORTHWEST OF ALBANY. DRIER AND MILDER WEATHER IS
EXPECTED AS WE MOVE AHEAD INTO THE UPCOMING WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1230 AM...FIRST I HAVE TO COMMEND THE PREVIOUS FORECASTERS ON
THEIR HOURLY CLOUD COVER GRIDS. PER SATELLITE PICTURES...THE GRID
FORECAST WAS NEARLY RIGHT ON! GOOD JOB!
ONLY MINOR TWEAKING ON THIS UPDATE...MAINLY TO TRIM BACK THE SNOW
SHOWERS. RADAR DOES INDICATE ANOTHER ROUND BEGINNING TO TRICKLE INTO
OUR WESTERN AREAS. MOST MODELS KEEP ANY MEASURABLE SNOW SHOWERS
ACROSS THE HIGHER ELEVATIONS. THE EXPERIMENTAL HRRR DOES INDICATE
SOME RETURNS AROUND 15 DBZ...MAINLY JUST NORTH OF THE MOHAWK
RIVER.
FOR NOW...KEEP MEASURABLE POPS NORTH AND WEST (EAST TOO) OF ALBANY
PROPER AND EVEN IN THOSE OTHER AREAS LOOKING AT MANY FLURRIES WITH A
BURST OF SLIGHTLY HEAVIER SNOW SHOWERS. THE ONLY ACCUMULATION SNOWS
LOOK TO BE ACROSS THE DACKS AND PERHAPS SOUTHERN GREENS WHERE UP TO
AN INCH COULD ACCUMULATE. ELSEWHERE...ANY PRECIPITATION THAT FALLS
MIGHT BE LIGHT ENOUGH AND COMBINED WITH SURFACE TEMPERATURES ABOVE
FREEZING TO EVEN FALL AS LIGHT RAIN SHOWERS (REALLY SPRINKLES).
EITHER WAY...NOT A BIG DEAL.
OTHERWISE...IT WILL REMAIN RATHER CLOUDS NORTH OF ALBANY...SUNSHINE
FADING BEHIND INCREASING CLOUDS SOUTH OF ALBANY. RIGHT IN THE
CAPITAL DISTRICT LOOKING FOR MORE CLOUDS THAN SUNSHINE BUT A FEW
BREAKS AS WE ARE GETTING RIGHT NOW.
ON GOING HIGH TEMPERATURES LOOK MOSTLY IN THE BALL PARK. DID TWEAK A
FEW PLACES UPWARD...BUT OVERALL IN PRETTY GOOD SHAPE. LOOK FOR HIGH
TEMPERATURES THIS AFTERNOON IN THE LOWER 40S MID HUDSON VALLEY AND
LOWER LITCHFIELD COUNTY...35-40 MOST OTHER VALLEY LOCATIONS...MID
20S TO LOWER 30S.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
IN THE WAKE OF THE LOW DEPARTURE...A LARGE HIGH PRESSURE SYSTEM
WILL TAKER CONTROL OF OUR WEATHER FOR MONDAY INTO TUESDAY.
THIS WILL NOT BE A VERY COLD AIRMASS SO TEMPS WILL BE NEAR OR
ABOVE NORMAL DURING THAT TIME. MAINLY CLEAR SKIES WILL ACCOMPANY
THIS HIGH PRESSURE CENTER TOO...
FOR TEMPS...HIGHS MONDAY TO BE AROUND 20 FOR THE DACKS TO MID
30S FOR THE MID HUDSON VALLEY...AND LOWS MONDAY NIGHT IN THE UPPER
SINGLE NUMBERS AND TEENS AS CLEAR SKIES AND LIGHT WINDS ALLOW FOR
GOOD RADIATIONAL COOLING. HIGHS ON TUESDAY CLIMB BACK INTO THE MID
30S FOR THE TERRAIN TO SOME LOWER 40S FOR THE MID HUDSON VALLEY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THE WEATHER WILL BEGIN RATHER QUIET TO START THE EXTENDED
PERIOD...AS HIGH PRESSURE REMAINS ANCHORED TO THE SOUTH AND WEST OF
THE REGION. TEMPS WILL BE SEASONABLE FOR TUESDAY NIGHT WITH TEENS
AND 20S FOR MOST AREAS. A SW FLOW AT PLACE IN THE LOW AND MID LEVELS
WILL ALLOW FOR MILDER AIR FOR WEDNESDAY WITH MID 30S TO MID 40S
ACROSS THE REGION.
A FAST MOVING NORTHERN STREAM SHORTWAVE WILL SLIDE BY TO THE NORTH
OF THE REGION ACROSS SOUTHERN CANADA FOR WED INTO WED NIGHT. THIS
MAY ALLOW FOR A FEW -SHSN FOR THE ADIRONDACKS...OTHERWISE IT WILL
REMAIN DRY. THIS SYSTEM MAY BRING A GLANCING SHOT OF COOLER AIR TO
THE REGION...AS TEMPS WILL BE A FEW DEGREES COOLER FOR THURSDAY
ACROSS THE AREA WITH CONTINUED DRY CONDITIONS.
A SLOW MOVING CUTOFF SYSTEM WILL EJECT OUT OF THE SOUTHERN PLAINS
TOWARDS THE NORTHEAST FOR THE LATE WEEK PERIOD. WITH THIS SYSTEM...A
SURGE OF WARMER AIR WILL ALLOW FOR MUCH ABOVE NORMAL TEMPS...AND
PRECIP WITH THIS SYSTEM WILL MAINLY FALL IN THE FORM OF RAIN
SHOWERS. HOWEVER...THE MODELS DISAGREE WITH THE EXACT SOLUTION FOR
THE LATTER PORTION OF THE WEEK...WHICH IS TYPICAL WHEN DEALING WITH
A CUTOFF 500 HPA LOW AND A SPLIT FLOW PATTERN. THE 00Z ECMWF IS MUCH
SLOWER BRINGING ANY SYSTEMS INTO THE AREA THAN THE 00Z GFS. THE 00Z
GGEM IS SIMILAR TO THE ECMWF. THE 00Z GEFS MEMBERS CONTINUE TO SHOW
VARIABILITY REGARDING TIMING/QPF TO THE REGION AS WELL. FOR NOW...WE
WILL TAKE A COMPROMISE AND CONTINUE TO SHOW SLIGHT CHC/LOW CHC POPS
FOR THURSDAY NIGHT...AND CHC POPS FOR FRI/FRI NIGHT...AND SLIGHT CHC
POPS INTO SATURDAY. HOWEVER...THIS IS WITH LOW CONFIDENCE...AS THE
GROWING MODEL CONSENSUS BETWEEN THE ECMWF/GGEM MAY SUGGEST THAT IT
REMAINS DRY EVEN INTO FRIDAY AS WELL...WITH PRECIP ARRIVING FOR FRI
NIGHT INTO THE WEEKEND. WE WILL CONTINUE TO SHOW MAX TEMPS REACHING
THE 40S FOR MOST AREAS FOR FRIDAY AND SATURDAY...WHICH IS ABOUT 10
DEGREES ABOVE NORMAL FOR THIS TIME OF YEAR. MIN TEMPS WILL DEPEND ON
THE EXACT TIMING OF THE PRECIP...BUT LOWS WILL ONLY DROP TO THE 20S
AND 30S...WITH SOME AREAS POSSIBLY NOT FALLING BELOW FREEZING EVEN
AT NIGHT.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
WEAK WARM AIR ADVECTION ASSOCIATED WITH A WARM FRONTAL BOUNDARY HAS
ALLOWED FOR A BAND OF SNOW SHOWERS TO MOVE THROUGH THE AREA EARLY
THIS MORNING. THESE SNOW SHOWERS HAVE MOVED EAST OF THE REGION...SO
NO ADDITIONAL SNOW IS EXPECTED DURING THE DAY TODAY.
HOWEVER...LINGERING LOW LEVEL MOISTURE IN THE WAKE OF THESE SNOW
SHOWERS HAS ALLOWED FOR SOME LOW STRATUS FOR KPSF/KGFL...AND A LIGHT
MIST AT KPOU. SOME IFR CIGS HAVE OCCURRED AT KGFL/KPSF. THIS SHOULD
BE SHORT-LIVED...HOWEVER...AS THIS LOW STRATUS/MIST SHOULD BEGIN TO
DISSIPATE/MIX OUT OVER THE NEXT FEW HOURS...ALTHOUGH MVFR CIGS MAY
CONTINUE AT KGFL/KPSF THROUGH THE MID TO LATE MORNING.
BY AFTN...ALL SITES SHOULD BE VFR WITH JUST SCT-BKN MID LEVEL
CLOUDS. LIGHT SW WINDS OF 7 KTS OR LESS WILL BE IN PLACE THROUGHOUT
THE AREA.
A COLD FRONT LOOKS TO APPROACH THE AREA FOR THIS EVENING AND INTO
THE OVERNIGHT HOURS...SO WILL HAVE BKN-OVC CIGS OF 4-7 KFT AND
INCLUDE A MENTION OF VCSH FOR A PASSING FLURRY FOR THE NORTHERN
TERMINALS. KPOU LOOKS TO STAY DRY WITH JUST SCT MID LEVEL CLOUDS.
FLYING CONDITIONS LOOK TO STAY VFR FOR THE MAJORITY OF THE TIME
OVERNIGHT TONIGHT. WESTERLY WINDS WILL BE AROUND 5 KTS.
OUTLOOK...
MON-WED...VFR. NO SIG WX.
THU...VFR/MVFR. CHC -RASN.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE EXPECTED THE NEXT 5 DAYS RELATED TO QPF...AS
MAINLY DRY WEATHER OR SNOW PRODUCING SYSTEMS WILL IMPACT THE ALBANY
HYDRO SERVICE AREA /HSA/. MOST OF THESE WILL BE RATHER LIGHT.
SOME RIVER GAGES ARE EXHIBITING SIGNS OF ICE EFFECTS...AND RIVER
LEVEL READINGS LOOK UNREPRESENTATIVE. ICE WILL CONTINUE TO FORM
AND THICKEN ON ALL WATERWAYS IN THE ALY HSA THROUGH THE WEEKEND.
WE WILL HAVE TO MONITOR FOR ANY FREEZE UP JAMS...ESPECIALLY ALONG
THE NRN PERIPHERY OF THE HSA.
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...BGM
NEAR TERM...HWJIV
SHORT TERM...BGM
LONG TERM...FRUGIS
AVIATION...FRUGIS
HYDROLOGY...GJM/BGM
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1005 AM EST SAT JAN 5 2013
.SYNOPSIS...
MAINLY DRY AND SEASONABLY COLD WEATHER WILL CONTINUE THROUGH
TODAY. THERE IS A CHANCE OF A FEW SNOW SHOWERS/FLURRIES LATE
TONIGHT INTO SUNDAY...AND AGAIN SUNDAY NIGHT INTO MONDAY.
TEMPERATURES WILL WARM TO ABOVE NORMAL LEVEL THE MIDDLE AND END
OF NEXT WEEK. DRY WEATHER SHOULD PREVAIL MUCH OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
10 AM UPDATE...
ONLY MINOR ADJUSTMENTS NECESSARY FOR THIS MID MORNING UPDATE.
LATEST MAV/RAP TEMPS/DEWPOINTS ARE LOOKING GOOD SO HAVE ADJUSTED
TOWARD THOSE VALUES FOR THE REMAINDER OF THE DAY.
OTHERWISE...STILL A BIT OF A LAKE CONNECTION WITH SOME LOW LVL
STRATO-CU IN THE W INTERIOR AND N OF ROUTE 2. IT MAY TAKE UNTIL
ABOUT MID AFTERNOON...ONCE A MORE NLY COMPONENT TO THE WIND SETS
IN FOR THIS CONNECTION TO CUTOFF. LIKED THE NAMDNG5 AND RAP WHICH
BOTH SHOWED THIS POTENTIAL SO HAVE ADJUSTED TOWARD THOSE SOLUTIONS
FOR SKIES. OTHERWISE MUCH OF THE FORECAST REMAINS ON TRACK.
PREVIOUS DISCUSSION...
MID LEVEL SHORTWAVE CONTINUING TO MAKE PROGRESS ACROSS NORTHERN
NEW ENGLAND EARLY THIS MORNING. WEST WINDS STARTING TO INCREASE AS
THIS PACKET OF ENERGY GET CLOSER. THESE WEST WINDS ARE STRONG
ENOUGH TO SUPPLY GREAT LAKES MOISTURE EAST OF THE BERKSHIRES.
EXPECTING THESE CLOUDS TO DECREASE THROUGH THE MORNING IN THE WAKE
OF THE DEPARTING SHORTWAVE. GUIDANCE IS DOING THIS TOO QUICKLY
THOUGH. SLOWED DOWN THE CLEARING BASED ON OBSERVED IR SATELLITE
DATA. EVEN SO...LOCATIONS NEAR THE BERKSHIRES AND ACROSS SOUTHERN
NH MAY HOLD ONTO CLOUDS LONGER THAN CURRENT FORECAST WHERE THE
GREAT LAKES MOISTURES A CONCERN.
TEMPERATURES WERE A BLEND OF THE MOS GUIDANCE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
ANOTHER MID-LEVEL SHORTWAVE APPROACHES FROM THE WEST. EXPECTING
INCREASING CLOUDS LATE THIS EVENING AND AFTER MIDNIGHT. THE FAIR
SKIES AND LIGHT WINDS SHOULD ALLOW FOR GOOD RADIATIONAL COOLING
DURING THE FIRST PART OF THE NIGHT. AS SUCH EXPECTING MINIMUM
TEMPERATURES BELOW FREEZING ACROSS ALL OF SOUTHERN NEW ENGLAND BY
THE TIME ANY PRECIPITATION ARRIVES.
THERE IS DECENT ISENTROPIC LIFT...BUT DEEP MOISTURE WILL CONTINUE
TO BE AN ISSUE. MOST OF THE 05/00Z GUIDANCE DEPICTS A SCENARIO
WHERE THERE IS A SMALL WINDOW OF OPPORTUNITY WHERE THERE ARE
ACTIVE ICE NUCLEI ACROSS THE REGION. THIS TIMING DOES NOT QUITE
MATCH UP WITH A MOIST BOUNDARY LAYER...SO MOST OF THE SNOW WHICH
IS GENERATED ALOFT WILL LIKELY SUBLIMATE INTO THE DRY AIR NEAR THE
SURFACE. EVENTUALLY THE COLUMN WILL BE SUFFICIENTLY MOIST FOR SOME
OF THE SNOW TO REACH THE GROUND. AT THAT POINT THOUGH THERE LIKELY
WILL NOT BE ENOUGH TIME TO ACCUMULATE MUCH.
MAINTAINED THE IDEA OF JUST A CHANCE OF MEASURABLE WATER
EQUIVALENT ACROSS SOUTHERN NEW ENGLAND FOR NOW. WILL NEED TO
KEEP AN EYE ON THE MOVING PARTS IN CASE THEY LINE UP BETTER LATE
TONIGHT INTO SUNDAY MORNING. EXPECTING MAINLY DRY WEATHER FOR THE
AFTERNOON AS THE TIMING OF A LOW PRESSURE IN THE SOUTHERN JET
STREAM LOOKS SLOWER.
TEMPERATURES WERE A BLEND OF THE MOS GUIDANCE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
HIGHLIGHTS...
* COLD TEMPS MON FOLLOWED BY WARMING TEMPS THRU THE WEEK
* RAIN POSSIBLE TOWARDS THE END OF THE WEEK
MODELS ARE IN GOOD AGREEMENT THROUGH THE TUESDAY. THEN DIFFERENCES
START TO APPEAR BETWEEN THE ECMWF AND THE GFS. GENERALLY A QUIET
PATTERN FOR SOUTHERN NEW ENGLAND THROUGH MID WEEK. COOLER
TEMPERATURES MONDAY WILL BE FOLLOWED BY A FAIRLY SIGNIFICANT WARM UP
THROUGH THE REST OF THE WEEK. MODELS DIFFER ON THE PATTERN FOR THE
END OF THE WEEK. THE GFS BRINGS LOW PRESSURE THROUGH QUEBEC WITH A
COLD FRONT THROUGH SOUTHERN NEW ENGLAND WEDNESDAY WHILE THE ECMWF
KEEPS HIGH PRESSURE AND DRY WEATHER. THEN ESSENTIALLY THE OPPOSITE
ON THURSDAY. FRIDAY...THEY AGREE ON ANOTHER LOW PRESSURE SYSTEM
MOVING THROUGH QUEBEC...WITH THE ECMWF BRINGING A COLD FRONT AND
PRECIP INTO SOUTHERN NEW ENGLAND AND THE GFS KEEPING THINGS DRY.
THE GFS ENSEMBLES LOOK PRETTY EVENLY SPLIT BETWEEN SOMETHING THAT
LOOKS LIKE THE OPERATIONAL GFS AND SOMETHING THAT LOOKS MORE LIKE
THE ECMWF. ALL THIS TO SAY CONFIDENCE IS LOW FOR THE LATER PART OF
THE WEEK.
SUNDAY NIGHT AND MONDAY...LOW PRESSURE MOVES THROUGH NORTHERN NEW
ENGLAND SUNDAY NIGHT...BRINGING A COLD FRONT ACROSS SOUTHERN NEW
ENGLAND. THIS FRONTAL PASSAGE LOOKS PRETTY STARVED FOR MOISTURE AT
THIS POINT. CAN/T RULE OUT A FEW FLURRIES...PARTICULARLY ACROSS THE
NORTHWESTERN ZONES...BUT EXPECT IT TO BE FAIRLY DRY. THIS WILL
BRING ONE MORE ROUND OF COLDER TEMPERATURES TO THE REGION MONDAY AS
HIGH PRESSURE BUILDS INTO THE AREA. AT TIMES MONDAY WHEN THE WIND
DIRECTION IS OFF THE OCEAN...MAY SEE A PERIOD OF OCEAN EFFECT SNOW
ALONG THE EAST COAST. WILL KEEP CHANCE POPS IN FOR THIS
POSSIBILITY.
TUESDAY...QUIET WEATHER EXPECTED WITH THE START OF A WARMING TREND
THAT WILL LAST THROUGHOUT THE WEEK.
WEDNESDAY THROUGH FRIDAY...AS STATED ABOVE THIS PERIOD HAS A LOT OF
UNCERTAINTY IN IT REGARDING THE POTENTIAL FOR RAIN. TEMPERATURE
PROFILES ARE FAIRLY SIMILAR ACROSS THE MODELS...WITH THE WARMING
TREND CONTINUING OR LEVELING OFF THROUGH THE END OF THE WEEK. WILL
INTRODUCE SLIGHT CHANCE POPS FOR WEDNESDAY AND THURSDAY TO ACCOUNT
FOR THE DIFFERENCES IN THE MODELS. KEEPING CHANCE POPS FOR FRIDAY
WHEN BOTH MODELS INDICATE SOME RAIN. NO PTYPE PROBLEMS HERE...TEMPERATURES
SHOULD BE WARM ENOUGH FOR RAIN ACROSS THE AREA. A BLEND OF MODEL
GUIDANCE SHOULD WORK WELL FOR TEMPERATURES.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
SHORT TERM...HIGH CONFIDENCE.
MAINLY VFR THROUGH TODAY. MVFR CIGS LIKELY TOWARD THE HIGHER
TERRAIN OF THE BERKSHIRES. GUSTY W-SW WINDS BECOMING NORTHWEST
AND DIMINISHING LATER TODAY. MVFR CONDITIONS POSSIBLE IN SCATTERED
SNOW SHOWERS LATE TONIGHT INTO SUNDAY. MOSTLY VFR BY SUNDAY
AFTERNOON.
KBOS TAF...HIGH CONFIDENCE IN TAF.
KBDL TAF...HIGH CONFIDENCE IN TAF.
OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY...
HIGH CONFIDENCE. MAINLY VFR CONDITIONS EXPECTED. LOW PROBABILITY
OF OCEAN EFFECT SNOW SHOWERS LOWERING CONDITIONS TO MVFR BRIEFLY
MONDAY.
&&
.MARINE...
HIGH CONFIDENCE IN AN IMPROVING TREND ACROSS THE COASTAL WATERS.
REPLACED GALE WARNINGS WITH SMALL CRAFT ADVISORIES BASED ON
LATEST BUOY OBSERVATIONS. STILL A LOW PROBABILITY FOR A GUST TO 35
KT ACROSS THE OUTER COASTAL WATERS EAST OF MASSACHUSETTS THIS
MORNING.
HIGH PRESSURE BUILDS OVER THE WATERS LATER TODAY. THIS WILL BRING
DIMINISHING WIND...BECOMING LIGHT THIS EVENING AND MUCH OF
TONIGHT. WINDS SHOULD INCREASE AGAIN LATE SUNDAY AS ANOTHER LOW
PRESSURE APPROACHES THE WATERS.
OUTLOOK...SUNDAY THROUGH WEDNESDAY...
MODERATE TO HIGH CONFIDENCE THROUGH WEDNESDAY.
SEAS WILL BE 5 TO 6 FEET ON THE OUTER WATERS THROUGH MUCH OF THE
PERIOD. WINDS WILL GUST TO SMALL CRAFT CRITERIA LATE SUNDAY NIGHT
INTO MONDAY MORNING AND AGAIN ON TUESDAY. OTHERWISE...WINDS REMAIN
BELOW SMALL CRAFT CRITERIA. SNOW SHOWERS ARE POSSIBLE MONDAY...
PARTICULARLY ON THE EASTERN WATERS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR
ANZ231>235-237-251-256.
SMALL CRAFT ADVISORY UNTIL 8 PM EST THIS EVENING FOR ANZ250-
254-255.
&&
$$
SYNOPSIS...BELK/RLG
NEAR TERM...BELK/DOODY
SHORT TERM...BELK
LONG TERM...RLG
AVIATION...BELK/RLG
MARINE...BELK/RLG
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
650 PM EST SUN JAN 6 2013
.UPDATE...
00Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS A COMPLEX UPPER LEVEL
PATTERN ACROSS THE CONUS THIS EVENING. MAIN FEATURE FOR OUR
SHORT-TERM WEATHER IS A LONGWAVE TROUGH PASSING TO OUR NORTH AND
APPROACHING THE EASTERN SEABOARD. OVERALL...NOT MUCH IN THE WAY OF
SYNOPTIC QG SUPPORT FOR LIFT OVER OUR AREA ASSOCIATED WITH THIS
TROUGH...HOWEVER WE ARE...FOR A SHORT TIME...UNDER THE FAVORABLE
ENTRANCE REGION OF A 150-160KT UPPER LEVEL JET. ASSOCIATED UPPER
LEVEL DIVERGENCE ALONG WITH SOME WEAK LOW LEVEL UPGLIDE ARE FORCING
A LARGE AREA OF SHOWERS AND A FEW ISOLATED STORMS OVER THE EASTERN
GULF OF MEXICO AND INLAND TO THE NATURE COAST ZONES. ADDITIONAL
SHOWERS FORCED BY DAYTIME HEATING/SEABREEZE INTERACTIONS (IS IT
JANUARY ?) HAVE MOVED WELL INLAND THIS EVENING AND WILL SLOWLY FADE
WITH THE LOSS OF DIURNAL HEATING.
THE BIG QUESTION FOR OUR FORECAST WILL BE HOW MUCH OF THE SHOWERS
ACTIVITY CURRENTLY OVER THE GULF AND NATURE COAST WILL REACH ZONES
FURTHER SOUTH AND EAST DURING THE OVERNIGHT HOURS. THIS HAS BEEN A
DIFFICULT SYSTEM TO FORECAST AS GUIDANCE HAS BEEN INCONSISTENT WITH
THE TIMING AND COVERAGE OF THE QPF FIELDS. THE SHOWERS/AREAS OF RAIN
HAVE NOT BEEN FAR OFFSHORE FOR A WHILE NOW...AND ARE ONLY SLOWLY
APPROACHING THE COAST. DO FEEL THAT WE WILL EVENTUALLY SEE THE
SHOWERS MAKE IT DOWN INTO THE I-4 CORRIDOR AND THE COASTAL SUNCOAST
ZONES LATER THIS EVENING...HOWEVER JUST HOW MUCH RAIN IS A BIG
QUESTION. OUR FAVORABLE LOCATION UNDER THE UPPER JET WILL NOT LAST
ALL THAT MUCH LONGER...AS THE JET TRANSLATES EASTWARD AND ALSO
WEAKENS WITH TIME ACCORDING TO THE GFS/ECMWF. MANY OF THE
HI-RESOLUTION CONVECTION ALLOWING GUIDANCE ALSO SHOW A DECREASE IN
SHOWER COVERAGE DURING THE SECOND HALF OF THE NIGHT AS THE WHOLE
SYSTEM PASSES OVER THE REGION. THEREFORE...THE RAIN IS
APPROACHING...BUT WE ARE RUNNING OUT OF TIME BEFORE THE SUPPORT FOR
ORGANIZED RAIN STARTS TO FADE.
IN TERMS OF THE GRIDS...WILL KEEP RAIN CHANCES HIGH TONIGHT...BUT
WILL BEGIN TO BACK OFF ON THE OVERALL RAIN TOTALS BASED ON THE
LATEST ENSEMBLE LOOK AT THE GUIDANCE.
FOR MONDAY...WEAK FRONTAL BOUNDARY WILL STILL BE ALIGNED OVER THE
SOUTHERN THIRD OF THE PENINSULA. GFS/NAM SHOWING SOME LEFTOVER
UPGLIDE ASSOCIATED WITH THIS BOUNDARY ALONG THE 295-305K SURFACES.
BEST CHANCE FOR LINGERING SHOWERS BY MONDAY AFTERNOON WOULD BE SOUTH
AND EAST OF THE I-4 CORRIDOR WHERE THIS WEAK LIFT IS COINCIDENT WITH
THE MOISTURE.
&&
.AVIATION...
LARGE AREA OF RAIN/SHOWERS WILL BRING TEMPO MVFR/IFR CONDITIONS 00Z
TO 05Z. STRATUS WILL PREVAIL OVERNIGHT WITH IFR TO PERHAPS LIFR
CEILINGS WITH SOME VISIBILITIES 3 TO 5 MILES. SLOW IMPROVEMENT AFTER
15Z MONDAY.
&&
.MARINE...
A FRONTAL BOUNDARY SAGS INTO SOUTH FL TONIGHT AND THEN LIFTS BACK
NORTH TO CENTRAL FL MON. THE BOUNDARY CONTINUES INTO NORTHERN FL TUE
AND DECAYS AS HIGH PRESSURE MOVES OFF THE EASTERN SEABOARD AND EAST
OVER THE OPEN ATLANTIC...BUT RIDGING BACK TO THE GULF.
NORTH AND NE WINDS TONIGHT INCREASE TO AROUND 15 TO 15-2O KT WITH
SOME MARINE SECTIONS HIGHLIGHTED FOR EXERCISE CAUTION. WINDS
CONTINUE ROBUST FOR THE NEXT DAY OR SO AND PERHAPS REACH AROUND
20KT. THE MAIN CONCERN WILL BE SCATTERED TO NUMEROUS SHOWERS WITH
ISOLATED THUNDERSTORMS MAINLY TONIGHT. WINDS MODERATE SOME FOR MID
TO LATE WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 59 74 60 80 / 80 30 10 20
FMY 64 80 63 84 / 50 30 10 20
GIF 57 74 59 81 / 80 30 10 20
SRQ 61 77 62 80 / 80 30 10 20
BKV 57 75 58 81 / 90 20 10 20
SPG 61 72 62 78 / 80 30 10 20
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
UPDATE...MROCZKA
AVIATION...JILLSON
MARINE...RUDE
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
157 PM CST SAT JAN 5 2013
.DISCUSSION...
1254 PM CST
UPDATE FOR THIS AFTERNOON...
UPPER LOW THAT WAS OVER THE TX AND OK PANHANDLE AREAS DURING THE
PREDAWN HAS REFORMED FURTHER TO THE NE THIS MORNING AND WAS
CURRENTLY MOVING NORTHEASTWARD OVER NW AND N CENTRAL MO.
MEANWHILE...A SHORT WAVE TROF WAS QUICKLY DROPPING SOUTHEASTWARD
ACROSS SD AND NE BEHIND THE LIFTING MID MS VALLEY UPPER LOW.
MODELS SHOW THE UPPER LOW GRADUALLY WEAKENING DURING THE
AFTERNOON AS IT REACHES NORTHERN IL BY 00Z. MODELS ALSO SHOW THE
PLAINS SHORT WAVE TROF CONTINUING TO MN AND NORTHERN IA BY 00Z
AND BEGINNING TO MERGE WITH THE WEAKENING UPPER LOW.
SATELLITE LOOP SHOWS COOLING TOPS MOVING ACROSS THE N HALF OF IL
IN IR...WHILE VIS LOOP SHOWS TEXTURED CLOUDS WITH A BIT OF A
CONVECTIVE NATURE TO THEM ACROSS MOST OF THE REGION. RADAR
COMPOSITE SHOWS ECHOES FROM FAR SE IA EASTWARD TO GENERALLY OVER
THE I-74 CORRIDOR THEN CURVING S AND SSW TO THE S TIP OF IL.
BASED ON CURRENT AND RECENT METARS SNOW IS FALLING FROM THE MID
TO BACK EDGE OF THE ECHO COVERAGE WHILE UNDER THE LEADING EDGE OF
THE ECHOES THE LOWER LAYERS ARE TOO DRY TO PREVENT METEORS FROM
EVAPORATING BEFORE REACHING THE SURFACE.
WHILE A RATHER UNUSUAL SET UP OF LOWER AND MID LEVEL COLD AIR
ADVECTION IS OCCURRING WITH THE SW FLOW AHEAD OF THE APPROACHING
DISTURBANCE THERE IS AN AREA OF MID LEVEL LEVEL ISENTROPIC UPGLIDE
INDICATED FROM NE MO TO NORTHERN IL MATCHING THE MORE INTENSE
ECHOES ACROSS THE NORTHERN PORTIONS OF IL. THE AREA OF MID LEVEL
LIFT IS PROGGED BY THE RAP TO BE OVER N CENTRAL AND NE IL INTO SE
WI AT 00Z.
AS THE AREA OF MID LEVEL LIFT CONTINUES TO MOVE OVER THE LOCAL
FORECAST AREA AND THE LOWER LEVELS MOISTEN THIS AFTERNOON
ANTICIPATE LIGHT SNOW BREAKING OUT. A FEW LOCATIONS UPSTREAM HAVE
REPORTED A BRIEF PERIOD OF VISIBILITY BETWEEN 3/4 AND 1 1/4 MI AS
A MORE INTENSE RADAR ECHO MOVED ACROSS THE SITE. ACCUMULATIONS
DURING THE AFTERNOON WILL BE AN INCH OR LESS AS OVERALL THE
SNOWFALL WILL LIGHT AND WITH TEMPERATURES IN THE LOWER AND MID
30S THE REST OF THE AFTERNOON WHAT DOES FALL WILL BE AT LEAST
PARTIALLY MELTING.
TRS
.PREV DISCUSSION...
334 AM CST
MAIN FORECAST CONCERN THIS MORNING WILL BE DETAILS OF SNOWFALL
ACROSS THE AREA THIS AFTERNOON AND EVENING...AS WELL AS A BIG WARM
UP IN STORE NEXT WEEK.
TODAY AND TONIGHT...CONFIDENCE HIGH
THIS MORNING...SATELLITE ANALYSIS SHOWS UPPER LOW SPINNING ACROSS
THE TX/OK PANHANDLE REGION WITH LEAD VORT MAX LIFTING NORTHEAST
ACROSS EASTERN OK. A SECOND NORTHERN STREAM SHORTWAVE IS MOVING
SOUTHEAST ACROSS NORTHERN ALBERTA. AT THE SURFACE...EXPANSIVE
RIDGING SPANS FROM THE MID APPALACHIAN RANGE SOUTHWEST INTO SOUTHERN
TEXAS...CUTTING OFF ACCESS TO ANY GULF MOISTURE.
MODELS ARE IN VERY GOOD AGREEMENT TODAY REGARDING THE EVOLUTION OF
THE CLOSED LOW OVER THE CENTRAL PLAINS THIS MORNING...INTO AN OPEN
WAVE AS IT MOVES ACROSS THE MID TO UPPER MISSISSIPPI VALLEY THIS
AFTERNOON...AND CONTINUES TO DAMPEN IS IT MOVES EAST OF THE FORECAST
AREA THIS EVENING. DESPITE MODERATE FORCING THAT IS ASSOCIATED WITH
THE DCVA OF THE UPPER WAVE AS IT MOVES ACROSS NORTHERN ILLINOIS
LATE THIS AFTERNOON...THE AIRMASS IN PLACE IS VERY DRY AND BELIEVE
MODELS SATURATE THE COLUMN TOO QUICKLY. EVENING RAOBS FROM ILX/DVN
INDICATED PWATS OF 0.20-0.23...HOWEVER GUIDANCE SHOWS RAPID
SATURATION OF THE COLUMN OVER JUST AN HOUR OR TWO. RAW GFS/NAM
SNOWFALL TOTALS AMOUNT TO ONE TO JUST OVER TWO INCHES FROM ROUGHLY
OTTAWA TO NEAR DOWNTOWN CHICAGO. PLACEMENT OF THE AXIS OF HEAVIEST
SNOW IS OKAY...HOWEVER SUSPECT THAT SNOWFALL WILL NOT BEGIN IN
EARNEST UNTIL CLOSER TO 20-21Z NEAR OTTAWA AND 22-23Z THIS EVENING
FOR CHICAGO...WHICH WILL COINCIDE WITH BETTER FORCING WITHIN THE
DENDRITIC GROWTH ZONE. WITH WBZ HEIGHTS NEAR THE SURFACE...AM NOT
TOO CONCERNED ABOUT MIXED PRECIP AT THE ONSET. TEMPERATURES
WARMING INTO THE MID 30S TODAY MAY ALSO MAKE IT A LITTLE TOUGH FOR
SNOW TO ACCUMULATE INITIALLY...SO ONLY EXPECT A DUSTING TO AROUND
HALF AN INCH THROUGH THIS EVENING.
DRIER MID LEVEL AIR QUICKLY MOVES IN BEHIND THE DEPARTING FIRST
UPPER WAVE THIS EVENING...AND WHILE THERE MAY BE A SHORT WINDOW
WHERE SEEDER FEEDER MECHANICS CONTINUE TO SUPPLY NUCLEI FOR SNOW
GROWTH...THE MID LEVEL DRY LAYER QUICKLY DEEPENS BY AROUND 03-04Z
LEAVING SHALLOW LOW LEVEL MOISTURE WITH TOPS AROUND -5C. THIS MAY
LEAD TO A CHANGE OVER TO FREEZING DRIZZLE AS SURFACE TEMPS FALL
BELOW THE FREEZING MARK...HOWEVER NAM GUIDANCE IN PARTICULAR IS
NOTORIOUS FOR HOLDING ONTO LOW LEVEL MOISTURE TOO LONG...AND WITH
GFS INDICATING SLIGHTLY DRIER AIR NEAR THE SURFACE...DOESNT LOOK
LIKE THIS WILL BE A WIDESPREAD/ACCUMULATING ICE AT THIS TIME.
MOTORISTS AND PEDESTRIANS SHOULD STILL BE WARY OF A FEW SLICK SPOTS
THIS EVENING AND OVERNIGHT.
SUNDAY THROUGH TUESDAY...CONFIDENCE HIGH
THE SECOND NORTHERN STREAM WAVE WILL MOVE ACROSS THE REGION SUNDAY
MORNING...AND SHOULD BE DEPARTING THE CWA BY EARLY AFTERNOON. EXPECT
EVEN LESS MOISTURE WITH THIS WAVE...SO AT BEST MAY SQUEEZE OUT A FEW
FLURRIES. SKIES SHOULD BEGIN TO CLEAR FROM THE WEST DURING THE
AFTERNOON AS ANTICYCLONIC FLOW/SURFACE RIDGING BEGIN TO WORK INTO
THE AREA. TEMPERATURES WILL BEGIN TO MODERATE THROUGH EARLY NEXT
WEEK AND EXPECT DRY CONDITIONS THROUGH TUESDAY WITH THE SURFACE
RIDGE MOVING OFF TO OUR EAST. FOR MONDAY AND TUESDAY...EXPECT MAX
TEMPS TO REBOUND BACK IN THE UPPER 30S TO AROUND 40 WITH LOW TEMPS
IN THE MID TO UPPER 20S.
WEDNESDAY THROUGH FRIDAY...CONFIDENCE LOW
WHILE THERE IS GENERAL AGREEMENT IN THE MODELS THROUGH TUESDAY
REGARDING RIDGING BUILDING ACROSS THE EASTERN CONUS WHILE A DEEP LOW
CUTS OFF OVER THE SOUTHWEST CONUS...SIGNIFICANT TIMING DIFFERENCES
DEVELOP IN THE MODELS BY WEDNESDAY. THE ECMWF HAS BEEN CONSISTENTLY
A SLOWER AND DEEPER MODEL WHILE THE GFS HAS TRENDED TOWARDS THIS
SOLUTION...WITH THE GEM A COMPROMISE. BY THURSDAY EXPECT THE LOW TO
LIFT NORTHEAST SOMEWHERE ACROSS THE MIDWEST...WITH HUGE IMPLICATIONS
ON THE TEMP/PRECIP FORECAST FROM MIDWEEK ON. GIVEN THE UNCERTAINTY
IN THE TRACK OF THE SYSTEM...DIDNT MAKE BIG CHANGES FROM GOING
FORECAST...THOUGH DID STAY SLIGHTLY WARMER THAN MODEL CONSENSUS
FAVORING THE WARMER SOLUTION OF THE MORE CONSISTENT ECMWF...WHICH
WOULD SUGGEST WARM AND RAINY CONDITIONS ESPECIALLY THURSDAY AS THE
LOW TAPS INTO GULF MOISTURE WITH STRONG WARM ADVECTION/MOISTURE
TRANSPORT UP THE MISSISSIPPI VALLEY. JUST TO HIGHLIGHT THE
DIFFERENCES IN SOLUTIONS...THE ECMWF SUGGESTS TEMPERATURES ON
THURSDAY IN THE MID TO UPPER 50S SOUTH OF I-80 WITH UPPER 40S TO MID
50S TO THE NORTH. MEANWHILE...THE GFS HAS MID 30S ACROSS THE ENTIRE
CWA THURSDAY. WILL HAVE TO CONTINUE TO MONITOR MODEL TRENDS WITH
THIS SYSTEM.
BMD
//PREV DISCUSSION...
334 AM CST
MAIN FORECAST CONCERN THIS MORNING WILL BE DETAILS OF SNOWFALL
ACROSS THE AREA THIS AFTERNOON AND EVENING...AS WELL AS A BIG WARM
UP IN STORE NEXT WEEK.
TODAY AND TONIGHT...CONFIDENCE HIGH
THIS MORNING...SATELLITE ANALYSIS SHOWS UPPER LOW SPINNING ACROSS
THE TX/OK PANHANDLE REGION WITH LEAD VORT MAX LIFTING NORTHEAST
ACROSS EASTERN OK. A SECOND NORTHERN STREAM SHORTWAVE IS MOVING
SOUTHEAST ACROSS NORTHERN ALBERTA. AT THE SURFACE...EXPANSIVE
RIDGING SPANS FROM THE MID APPALACHIAN RANGE SOUTHWEST INTO SOUTHERN
TEXAS...CUTTING OFF ACCESS TO ANY GULF MOISTURE.
MODELS ARE IN VERY GOOD AGREEMENT TODAY REGARDING THE EVOLUTION OF
THE CLOSED LOW OVER THE CENTRAL PLAINS THIS MORNING...INTO AN OPEN
WAVE AS IT MOVES ACROSS THE MID TO UPPER MISSISSIPPI VALLEY THIS
AFTERNOON...AND CONTINUES TO DAMPEN IS IT MOVES EAST OF THE FORECAST
AREA THIS EVENING. DESPITE MODERATE FORCING THAT IS ASSOCIATED WITH
THE DCVA OF THE UPPER WAVE AS IT MOVES ACROSS NORTHERN ILLINOIS
LATE THIS AFTERNOON...THE AIRMASS IN PLACE IS VERY DRY AND BELIEVE
MODELS SATURATE THE COLUMN TOO QUICKLY. EVENING RAOBS FROM ILX/DVN
INDICATED PWATS OF 0.20-0.23...HOWEVER GUIDANCE SHOWS RAPID
SATURATION OF THE COLUMN OVER JUST AN HOUR OR TWO. RAW GFS/NAM
SNOWFALL TOTALS AMOUNT TO ONE TO JUST OVER TWO INCHES FROM ROUGHLY
OTTAWA TO NEAR DOWNTOWN CHICAGO. PLACEMENT OF THE AXIS OF HEAVIEST
SNOW IS OKAY...HOWEVER SUSPECT THAT SNOWFALL WILL NOT BEGIN IN
EARNEST UNTIL CLOSER TO 20-21Z NEAR OTTAWA AND 22-23Z THIS EVENING
FOR CHICAGO...WHICH WILL COINCIDE WITH BETTER FORCING WITHIN THE
DENDRITIC GROWTH ZONE. WITH WBZ HEIGHTS NEAR THE SURFACE...AM NOT
TOO CONCERNED ABOUT MIXED PRECIP AT THE ONSET. TEMPERATURES
WARMING INTO THE MID 30S TODAY MAY ALSO MAKE IT A LITTLE TOUGH FOR
SNOW TO ACCUMULATE INITIALLY...SO ONLY EXPECT A DUSTING TO AROUND
HALF AN INCH THROUGH THIS EVENING.
DRIER MID LEVEL AIR QUICKLY MOVES IN BEHIND THE DEPARTING FIRST
UPPER WAVE THIS EVENING...AND WHILE THERE MAY BE A SHORT WINDOW
WHERE SEEDER FEEDER MECHANICS CONTINUE TO SUPPLY NUCLEI FOR SNOW
GROWTH...THE MID LEVEL DRY LAYER QUICKLY DEEPENS BY AROUND 03-04Z
LEAVING SHALLOW LOW LEVEL MOISTURE WITH TOPS AROUND -5C. THIS MAY
LEAD TO A CHANGE OVER TO FREEZING DRIZZLE AS SURFACE TEMPS FALL
BELOW THE FREEZING MARK...HOWEVER NAM GUIDANCE IN PARTICULAR IS
NOTORIOUS FOR HOLDING ONTO LOW LEVEL MOISTURE TOO LONG...AND WITH
GFS INDICATING SLIGHTLY DRIER AIR NEAR THE SURFACE...DOESNT LOOK
LIKE THIS WILL BE A WIDESPREAD/ACCUMULATING ICE AT THIS TIME.
MOTORISTS AND PEDESTRIANS SHOULD STILL BE WARY OF A FEW SLICK SPOTS
THIS EVENING AND OVERNIGHT.
SUNDAY THROUGH TUESDAY...CONFIDENCE HIGH
THE SECOND NORTHERN STREAM WAVE WILL MOVE ACROSS THE REGION SUNDAY
MORNING...AND SHOULD BE DEPARTING THE CWA BY EARLY AFTERNOON. EXPECT
EVEN LESS MOISTURE WITH THIS WAVE...SO AT BEST MAY SQUEEZE OUT A FEW
FLURRIES. SKIES SHOULD BEGIN TO CLEAR FROM THE WEST DURING THE
AFTERNOON AS ANTICYCLONIC FLOW/SURFACE RIDGING BEGIN TO WORK INTO
THE AREA. TEMPERATURES WILL BEGIN TO MODERATE THROUGH EARLY NEXT
WEEK AND EXPECT DRY CONDITIONS THROUGH TUESDAY WITH THE SURFACE
RIDGE MOVING OFF TO OUR EAST. FOR MONDAY AND TUESDAY...EXPECT MAX
TEMPS TO REBOUND BACK IN THE UPPER 30S TO AROUND 40 WITH LOW TEMPS
IN THE MID TO UPPER 20S.
WEDNESDAY THROUGH FRIDAY...CONFIDENCE LOW
WHILE THERE IS GENERAL AGREEMENT IN THE MODELS THROUGH TUESDAY
REGARDING RIDGING BUILDING ACROSS THE EASTERN CONUS WHILE A DEEP LOW
CUTS OFF OVER THE SOUTHWEST CONUS...SIGNIFICANT TIMING DIFFERENCES
DEVELOP IN THE MODELS BY WEDNESDAY. THE ECMWF HAS BEEN CONSISTENTLY
A SLOWER AND DEEPER MODEL WHILE THE GFS HAS TRENDED TOWARDS THIS
SOLUTION...WITH THE GEM A COMPROMISE. BY THURSDAY EXPECT THE LOW TO
LIFT NORTHEAST SOMEWHERE ACROSS THE MIDWEST...WITH HUGE IMPLICATIONS
ON THE TEMP/PRECIP FORECAST FROM MIDWEEK ON. GIVEN THE UNCERTAINTY
IN THE TRACK OF THE SYSTEM...DIDNT MAKE BIG CHANGES FROM GOING
FORECAST...THOUGH DID STAY SLIGHTLY WARMER THAN MODEL CONSENSUS
FAVORING THE WARMER SOLUTION OF THE MORE CONSISTENT ECMWF...WHICH
WOULD SUGGEST WARM AND RAINY CONDITIONS ESPECIALLY THURSDAY AS THE
LOW TAPS INTO GULF MOISTURE WITH STRONG WARM ADVECTION/MOISTURE
TRANSPORT UP THE MISSISSIPPI VALLEY. JUST TO HIGHLIGHT THE
DIFFERENCES IN SOLUTIONS...THE ECMWF SUGGESTS TEMPERATURES ON
THURSDAY IN THE MID TO UPPER 50S SOUTH OF I-80 WITH UPPER 40S TO MID
50S TO THE NORTH. MEANWHILE...THE GFS HAS MID 30S ACROSS THE ENTIRE
CWA THURSDAY. WILL HAVE TO CONTINUE TO MONITOR MODEL TRENDS WITH
THIS SYSTEM.
BMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* WET LIGHT SNOW BEGINNING LIKELY WITHIN 2030-2100Z AND LASTING
FOR A FEW HOURS WITH A PERIOD OF TEMPORARY MORE INTENSE RATES
AND IFR VISBYS.
* TEMPORARY MVFR CIGS BECOMING WIDESPREAD BY LATER THIS EVE.
* A PROBABLE PERIOD OF DRIZZLE...WHICH DEPENDING ON TEMPS COULD BE
FREEZING DRIZZLE.
* GUSTY S WINDS GRADUALLY VEERING TO WNW BY SUNDAY MORNING.
//DISCUSSION...UPDATED 20Z...
AXIS OF SNOW CONTINUES TO SHIFT ENE TOWARD THE CHICAGOLAND TAF
SITES. SOON AFTER START THIS WILL LIKELY SEE TEMPORARY IFR
VISIBILITY...AND SUCH HAS BEEN OBSERVED HERE AT THE WEATHER
FORECAST OFFICE. CONFIDENCE DIMINISHES BEYOND THIS...ALTHOUGH A
PERIOD OF DRIZZLE LOOKS SLIGHTLY MORE PROBABLE THIS EVE...AND
TEMPERATURES WOULD LIKELY BE ABOVE FREEZING AT THAT TIME.
//PREV DISCUSSION...UPDATED 18Z...
A STRONG UPPER LEVEL DISTURBANCE ACROSS NORTHERN MO EARLY THIS
AFTERNOON IS SHIFTING NORTHEAST TOWARD THE AREA AND WILL MOVE
OVERHEAD CHICAGO AROUND 00Z...WITH ANOTHER ONE ACROSS WESTERN MN
TO MOVE OVER ON ITS HEELS OVERNIGHT. THE FIRST WAVE WILL CONTINUE
TO USHER AN ARC OF SNOW SHOWERS NORTHWARD ACROSS IL AND INTO NW
IN. PERIODIC VISIBILITIES OF UNDER ONE AND A HALF MILES HAVE BEEN
OBSERVED...HOWEVER THESE HAVE BEEN QUITE BRIEF. THESE TEMPORARY
LOWER VISIBILITIES WILL PERSIST WITH THIS AREA THROUGH THE
AFTERNOON...AND EXPECT THAT THE RADAR ECHOES WILL FILL IN SOME
BEHIND THIS LEADING ARC. A BRIEF MIX WITH RAIN IS POSSIBLE AT
FIRST...BUT THE MAIN PRECIP TYPE SHOULD BE WET AND POSSIBLY LARGE
SNOWFLAKES. TOTAL SNOW ACCUMULATION WILL LIKELY BE BETWEEN A FEW
TENTHS OF AN INCH TO HIGHEST CASE SCENARIO AROUND AN INCH. AS THIS
INITIAL WAVE PASSES...A PERIOD OF SOMEWHAT WEAK FORCING WILL BE IN
PLACE...BUT ENOUGH SO THAT TEMPORARY LIGHT SNOW/FLURRIES AS WELL
AS DRIZZLE WILL BE POSSIBLE. TEMPERATURES WILL FALL TO BELOW
FREEZING POTENTIALLY AS EARLY AS 03Z-06Z...BUT DEFINITELY BY EARLY
OVERNIGHT CREATING THE POTENTIAL FOR FZDZ IF INDEED DRIZZLE CAN
UNFOLD. AS THE SECOND UPPER LEVEL DISTURBANCE MOVES JUST TO THE
NORTH...SCATTERED LIGHT SNOW SHOWERS MAY BE SEEN LATE TONIGHT INTO
EARLY SUNDAY MORNING. WINDS WILL BE GUSTY FROM THE S VEERING TO
THE WNW BY DAYBREAK SUNDAY MORNING BEHIND A SURFACE COLD FRONT.
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN SNOW OCCURRING AND TIMING...WITH HIGH
CONFIDENCE IN TEMPORARY IFR VISIBILITY...THOUGH MEDIUM
CONFIDENCE IN DURATION.
* LOW CONFIDENCE IN CIGS TONIGHT. CIGS VERY WELL COULD BE HIGHER
WITH ONLY PATCHES OF SUB 2000 FT CIGS...BUT IF DRIZZLE IS
WIDESPREAD...IFR CIGS ARE LIKELY.
* LOW CONFIDENCE IN FZDZ AT ANY ONE TAF SITE.
* HIGH CONFIDENCE IN WIND TRENDS.
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT THROUGH WEDNESDAY...VFR.
WEDNESDAY NIGHT AND THURSDAY...CHANCE SHRA/DZ AND MVFR WITH IFR
POSSIBLE.
FRIDAY...SLIGHT CHANCE SHRA...MVFR POSSIBLE.
MTF
&&
.MARINE...
257 AM CST
A TROUGH OF LOW PRESSURE EXTENDS ACROSS NORTHERN LAKE MICHIGAN FROM
A LOW CENTERED OVER MAINE EARLY THIS MORNING. HIGH PRESSURE WILL
SPREAD ACROSS THE LAKE FROM THE NORTHWEST THIS MORNING THEN QUICKLY
BE PUSHED EASTWARD AS WEAK LOW PRESSURE CURRENTLY OVER THE WESTERN
DAKOTAS MOVES IN. WILL SEE A STEADY DECREASE IN WIND SPEEDS THROUGH
THE MORNING AS THE HIGH ARRIVES BEFORE AN INCREASE IN WEST AND
SOUTHWEST WINDS COMMENCES THIS AFTERNOON AS THE LOW ARRIVES FROM
THE WEST. EXPECT THE HIGHEST SPEEDS ACROSS THE SOUTHERN HALF OF
THE LAKE. THE LOW WILL SHIFT EAST OF THE LAKE SUNDAY MORNING
BRINGING A SHIFT TO NORTHWEST WINDS WITH SPEEDS REMAINING ELEVATED
INTO THE AFTERNOON BEFORE DROPPING OFF DURING THE EVENING AS HIGH
PRESSURE RETURNS. THIS HIGH WILL QUICKLY SHIFT EAST AS WELL WITH
STRONG LOW PRESSURE MOVING ACROSS THE CANADIAN PRAIRIES BEHIND IT.
THE PRESSURE GRADIENT WILL STRENGTHEN CONSIDERABLY ON MONDAY WITH
SOUTHWEST WINDS INCREASING THROUGH THE DAY. THE LOW WILL PASS
NORTH OF THE LAKE AND MAY DEEPEN SLIGHTLY AS IT DOES SO MONDAY
NIGHT. AS A RESULT...MID RANGE SOUTHWEST GALES ARE LOOKING MORE
LIKELY BY LATE MONDAY AFTERNOON BUT EASE TUESDAY MORNING AS THE
LOW MOVES INTO NORTHERN QUEBEC AND WEAK HIGH PRESSURE RIDGING
ARRIVES. WILL BUMP FORECAST WORDING UP TO GALES AND CARRY 40 KT
NORTH FOR NOW BUT THERE IS SOME POTENTIAL TO BE CLOSER TO 45 KT
FOR AT LEAST A SHORT TIME MONDAY EVENING IF THE LOW DEEPENS
SUFFICIENTLY. WINDS SHOULD BE CLOSER TO 30-35 KT SOUTH. BEYOND
THAT CONFIDENCE LOWERS BUT THE PATTERN LOOKS TO REMAIN ACTIVE WITH
ANOTHER LOW PASSING NORTH OF THE LAKE TUESDAY NIGHT. THE SOUTHERN
STREAM OF FLOW LOOKS TO BECOME MORE ACTIVE AND LOW PRESSURE MAY
MOVE UP FROM THE SOUTHWEST LATE NEXT WEEK.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1254 PM CST SAT JAN 5 2013
.DISCUSSION...
1254 PM CST
UPDATE FOR THIS AFTERNOON...
UPPER LOW THAT WAS OVER THE TX AND OK PANHANDLE AREAS DURING THE
PREDAWN HAS REFORMED FURTHER TO THE NE THIS MORNING AND WAS
CURRENTLY MOVING NORTHEASTWARD OVER NW AND N CENTRAL MO.
MEANWHILE...A SHORT WAVE TROF WAS QUICKLY DROPPING SOUTHEASTWARD
ACROSS SD AND NE BEHIND THE LIFTING MID MS VALLEY UPPER LOW.
MODELS SHOW THE UPPER LOW GRADUALLY WEAKENING DURING THE
AFTERNOON AS IT REACHES NORTHERN IL BY 00Z. MODELS ALSO SHOW THE
PLAINS SHORT WAVE TROF CONTINUING TO MN AND NORTHERN IA BY 00Z
AND BEGINNING TO MERGE WITH THE WEAKENING UPPER LOW.
SATELLITE LOOP SHOWS COOLING TOPS MOVING ACROSS THE N HALF OF IL
IN IR...WHILE VIS LOOP SHOWS TEXTURED CLOUDS WITH A BIT OF A
CONVECTIVE NATURE TO THEM ACROSS MOST OF THE REGION. RADAR
COMPOSITE SHOWS ECHOES FROM FAR SE IA EASTWARD TO GENERALLY OVER
THE I-74 CORRIDOR THEN CURVING S AND SSW TO THE S TIP OF IL.
BASED ON CURRENT AND RECENT METARS SNOW IS FALLING FROM THE MID
TO BACK EDGE OF THE ECHO COVERAGE WHILE UNDER THE LEADING EDGE OF
THE ECHOES THE LOWER LAYERS ARE TOO DRY TO PREVENT METEORS FROM
EVAPORATING BEFORE REACHING THE SURFACE.
WHILE A RATHER UNUSUAL SET UP OF LOWER AND MID LEVEL COLD AIR
ADVECTION IS OCCURRING WITH THE SW FLOW AHEAD OF THE APPROACHING
DISTURBANCE THERE IS AN AREA OF MID LEVEL LEVEL ISENTROPIC UPGLIDE
INDICATED FROM NE MO TO NORTHERN IL MATCHING THE MORE INTENSE
ECHOES ACROSS THE NORTHERN PORTIONS OF IL. THE AREA OF MID LEVEL
LIFT IS PROGGED BY THE RAP TO BE OVER N CENTRAL AND NE IL INTO SE
WI AT 00Z.
AS THE AREA OF MID LEVEL LIFT CONTINUES TO MOVE OVER THE LOCAL
FORECAST AREA AND THE LOWER LEVELS MOISTEN THIS AFTERNOON
ANTICIPATE LIGHT SNOW BREAKING OUT. A FEW LOCATIONS UPSTREAM HAVE
REPORTED A BRIEF PERIOD OF VISIBILITY BETWEEN 3/4 AND 1 1/4 MI AS
A MORE INTENSE RADAR ECHO MOVED ACROSS THE SITE. ACCUMULATIONS
DURING THE AFTERNOON WILL BE AN INCH OR LESS AS OVERALL THE
SNOWFALL WILL LIGHT AND WITH TEMPERATURES IN THE LOWER AND MID
30S THE REST OF THE AFTERNOON WHAT DOES FALL WILL BE AT LEAST
PARTIALLY MELTING.
TRS
.PREV DISCUSSION...
334 AM CST
MAIN FORECAST CONCERN THIS MORNING WILL BE DETAILS OF SNOWFALL
ACROSS THE AREA THIS AFTERNOON AND EVENING...AS WELL AS A BIG WARM
UP IN STORE NEXT WEEK.
TODAY AND TONIGHT...CONFIDENCE HIGH
THIS MORNING...SATELLITE ANALYSIS SHOWS UPPER LOW SPINNING ACROSS
THE TX/OK PANHANDLE REGION WITH LEAD VORT MAX LIFTING NORTHEAST
ACROSS EASTERN OK. A SECOND NORTHERN STREAM SHORTWAVE IS MOVING
SOUTHEAST ACROSS NORTHERN ALBERTA. AT THE SURFACE...EXPANSIVE
RIDGING SPANS FROM THE MID APPALACHIAN RANGE SOUTHWEST INTO SOUTHERN
TEXAS...CUTTING OFF ACCESS TO ANY GULF MOISTURE.
MODELS ARE IN VERY GOOD AGREEMENT TODAY REGARDING THE EVOLUTION OF
THE CLOSED LOW OVER THE CENTRAL PLAINS THIS MORNING...INTO AN OPEN
WAVE AS IT MOVES ACROSS THE MID TO UPPER MISSISSIPPI VALLEY THIS
AFTERNOON...AND CONTINUES TO DAMPEN IS IT MOVES EAST OF THE FORECAST
AREA THIS EVENING. DESPITE MODERATE FORCING THAT IS ASSOCIATED WITH
THE DCVA OF THE UPPER WAVE AS IT MOVES ACROSS NORTHERN ILLINOIS
LATE THIS AFTERNOON...THE AIRMASS IN PLACE IS VERY DRY AND BELIEVE
MODELS SATURATE THE COLUMN TOO QUICKLY. EVENING RAOBS FROM ILX/DVN
INDICATED PWATS OF 0.20-0.23...HOWEVER GUIDANCE SHOWS RAPID
SATURATION OF THE COLUMN OVER JUST AN HOUR OR TWO. RAW GFS/NAM
SNOWFALL TOTALS AMOUNT TO ONE TO JUST OVER TWO INCHES FROM ROUGHLY
OTTAWA TO NEAR DOWNTOWN CHICAGO. PLACEMENT OF THE AXIS OF HEAVIEST
SNOW IS OKAY...HOWEVER SUSPECT THAT SNOWFALL WILL NOT BEGIN IN
EARNEST UNTIL CLOSER TO 20-21Z NEAR OTTAWA AND 22-23Z THIS EVENING
FOR CHICAGO...WHICH WILL COINCIDE WITH BETTER FORCING WITHIN THE
DENDRITIC GROWTH ZONE. WITH WBZ HEIGHTS NEAR THE SURFACE...AM NOT
TOO CONCERNED ABOUT MIXED PRECIP AT THE ONSET. TEMPERATURES
WARMING INTO THE MID 30S TODAY MAY ALSO MAKE IT A LITTLE TOUGH FOR
SNOW TO ACCUMULATE INITIALLY...SO ONLY EXPECT A DUSTING TO AROUND
HALF AN INCH THROUGH THIS EVENING.
DRIER MID LEVEL AIR QUICKLY MOVES IN BEHIND THE DEPARTING FIRST
UPPER WAVE THIS EVENING...AND WHILE THERE MAY BE A SHORT WINDOW
WHERE SEEDER FEEDER MECHANICS CONTINUE TO SUPPLY NUCLEI FOR SNOW
GROWTH...THE MID LEVEL DRY LAYER QUICKLY DEEPENS BY AROUND 03-04Z
LEAVING SHALLOW LOW LEVEL MOISTURE WITH TOPS AROUND -5C. THIS MAY
LEAD TO A CHANGE OVER TO FREEZING DRIZZLE AS SURFACE TEMPS FALL
BELOW THE FREEZING MARK...HOWEVER NAM GUIDANCE IN PARTICULAR IS
NOTORIOUS FOR HOLDING ONTO LOW LEVEL MOISTURE TOO LONG...AND WITH
GFS INDICATING SLIGHTLY DRIER AIR NEAR THE SURFACE...DOESNT LOOK
LIKE THIS WILL BE A WIDESPREAD/ACCUMULATING ICE AT THIS TIME.
MOTORISTS AND PEDESTRIANS SHOULD STILL BE WARY OF A FEW SLICK SPOTS
THIS EVENING AND OVERNIGHT.
SUNDAY THROUGH TUESDAY...CONFIDENCE HIGH
THE SECOND NORTHERN STREAM WAVE WILL MOVE ACROSS THE REGION SUNDAY
MORNING...AND SHOULD BE DEPARTING THE CWA BY EARLY AFTERNOON. EXPECT
EVEN LESS MOISTURE WITH THIS WAVE...SO AT BEST MAY SQUEEZE OUT A FEW
FLURRIES. SKIES SHOULD BEGIN TO CLEAR FROM THE WEST DURING THE
AFTERNOON AS ANTICYCLONIC FLOW/SURFACE RIDGING BEGIN TO WORK INTO
THE AREA. TEMPERATURES WILL BEGIN TO MODERATE THROUGH EARLY NEXT
WEEK AND EXPECT DRY CONDITIONS THROUGH TUESDAY WITH THE SURFACE
RIDGE MOVING OFF TO OUR EAST. FOR MONDAY AND TUESDAY...EXPECT MAX
TEMPS TO REBOUND BACK IN THE UPPER 30S TO AROUND 40 WITH LOW TEMPS
IN THE MID TO UPPER 20S.
WEDNESDAY THROUGH FRIDAY...CONFIDENCE LOW
WHILE THERE IS GENERAL AGREEMENT IN THE MODELS THROUGH TUESDAY
REGARDING RIDGING BUILDING ACROSS THE EASTERN CONUS WHILE A DEEP LOW
CUTS OFF OVER THE SOUTHWEST CONUS...SIGNIFICANT TIMING DIFFERENCES
DEVELOP IN THE MODELS BY WEDNESDAY. THE ECMWF HAS BEEN CONSISTENTLY
A SLOWER AND DEEPER MODEL WHILE THE GFS HAS TRENDED TOWARDS THIS
SOLUTION...WITH THE GEM A COMPROMISE. BY THURSDAY EXPECT THE LOW TO
LIFT NORTHEAST SOMEWHERE ACROSS THE MIDWEST...WITH HUGE IMPLICATIONS
ON THE TEMP/PRECIP FORECAST FROM MIDWEEK ON. GIVEN THE UNCERTAINTY
IN THE TRACK OF THE SYSTEM...DIDNT MAKE BIG CHANGES FROM GOING
FORECAST...THOUGH DID STAY SLIGHTLY WARMER THAN MODEL CONSENSUS
FAVORING THE WARMER SOLUTION OF THE MORE CONSISTENT ECMWF...WHICH
WOULD SUGGEST WARM AND RAINY CONDITIONS ESPECIALLY THURSDAY AS THE
LOW TAPS INTO GULF MOISTURE WITH STRONG WARM ADVECTION/MOISTURE
TRANSPORT UP THE MISSISSIPPI VALLEY. JUST TO HIGHLIGHT THE
DIFFERENCES IN SOLUTIONS...THE ECMWF SUGGESTS TEMPERATURES ON
THURSDAY IN THE MID TO UPPER 50S SOUTH OF I-80 WITH UPPER 40S TO MID
50S TO THE NORTH. MEANWHILE...THE GFS HAS MID 30S ACROSS THE ENTIRE
CWA THURSDAY. WILL HAVE TO CONTINUE TO MONITOR MODEL TRENDS WITH
THIS SYSTEM.
BMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* WET LIGHT SNOW BEGINNING LIKELY WITHIN 2100-2130Z AND LASTING
FOR A FEW HOURS WITH A PERIOD OF TEMPORARY MORE INTENSE RATES
AND IFR VISBYS.
* TEMPORARY MVFR CIGS BECOMING WIDESPREAD BY LATER THIS EVE.
* A CHANCE FOR FREEZING DRIZZLE LATE THIS EVE INTO OVERNIGHT.
* GUSTY S WINDS GRADUALLY VEERING TO WNW BY SUNDAY MORNING.
//DISCUSSION...UPDATED 18Z...
A STRONG UPPER LEVEL DISTURBANCE ACROSS NORTHERN MO EARLY THIS
AFTERNOON IS SHIFTING NORTHEAST TOWARD THE AREA AND WILL MOVE
OVERHEAD CHICAGO AROUND 00Z...WITH ANOTHER ONE ACROSS WESTERN MN
TO MOVE OVER ON ITS HEELS OVERNIGHT. THE FIRST WAVE WILL CONTINUE
TO USHER AN ARC OF SNOW SHOWERS NORTHWARD ACROSS IL AND INTO NW
IN. PERIODIC VISIBILITIES OF UNDER ONE AND A HALF MILES HAVE BEEN
OBSERVED...HOWEVER THESE HAVE BEEN QUITE BRIEF. THESE TEMPORARY
LOWER VISIBILITIES WILL PERSIST WITH THIS AREA THROUGH THE
AFTERNOON...AND EXPECT THAT THE RADAR ECHOES WILL FILL IN SOME
BEHIND THIS LEADING ARC. A BRIEF MIX WITH RAIN IS POSSIBLE AT
FIRST...BUT THE MAIN PRECIP TYPE SHOULD BE WET AND POSSIBLY LARGE
SNOWFLAKES. TOTAL SNOW ACCUMULATION WILL LIKELY BE BETWEEN A FEW
TENTHS OF AN INCH TO HIGHEST CASE SCENARIO AROUND AN INCH. AS THIS
INITIAL WAVE PASSES...A PERIOD OF SOMEWHAT WEAK FORCING WILL BE IN
PLACE...BUT ENOUGH SO THAT TEMPORARY LIGHT SNOW/FLURRIES AS WELL
AS DRIZZLE WILL BE POSSIBLE. TEMPERATURES WILL FALL TO BELOW
FREEZING POTENTIALLY AS EARLY AS 03Z-06Z...BUT DEFINITELY BY EARLY
OVERNIGHT CREATING THE POTENTIAL FOR FZDZ IF INDEED DRIZZLE CAN
UNFOLD. AS THE SECOND UPPER LEVEL DISTURBANCE MOVES JUST TO THE
NORTH...SCATTERED LIGHT SNOW SHOWERS MAY BE SEEN LATE TONIGHT INTO
EARLY SUNDAY MORNING. WINDS WILL BE GUSTY FROM THE S VEERING TO
THE WNW BY DAYBREAK SUNDAY MORNING BEHIND A SURFACE COLD FRONT.
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN SNOW OCCURRING. MEDIUM CONFIDENCE IN TIMING
AND LOWEST VISBYS AND CIGS.
* LOW CONFIDENCE IN CIGS TONIGHT. CIGS VERY WELL COULD BE HIGHER
WITH ONLY PATCHES OF SUB 2000 FT CIGS...BUT IF DRIZZLE WERE TO
OCCUR...EVEN DOWN TO IFR IS PROBABLE.
* LOW CONFIDENCE IN FZDZ AT ANY ONE TAF SITE.
* HIGH CONFIDENCE IN WIND TRENDS.
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 18Z...
SUNDAY NIGHT THROUGH WEDNESDAY...VFR.
WEDNESDAY NIGHT AND THURSDAY...CHANCE SHRA/DZ AND MVFR WITH IFR
POSSIBLE.
FRIDAY...SLIGHT CHANCE SHRA...MVFR POSSIBLE.
MTF
&&
.MARINE...
257 AM CST
A TROUGH OF LOW PRESSURE EXTENDS ACROSS NORTHERN LAKE MICHIGAN FROM
A LOW CENTERED OVER MAINE EARLY THIS MORNING. HIGH PRESSURE WILL
SPREAD ACROSS THE LAKE FROM THE NORTHWEST THIS MORNING THEN QUICKLY
BE PUSHED EASTWARD AS WEAK LOW PRESSURE CURRENTLY OVER THE WESTERN
DAKOTAS MOVES IN. WILL SEE A STEADY DECREASE IN WIND SPEEDS THROUGH
THE MORNING AS THE HIGH ARRIVES BEFORE AN INCREASE IN WEST AND
SOUTHWEST WINDS COMMENCES THIS AFTERNOON AS THE LOW ARRIVES FROM
THE WEST. EXPECT THE HIGHEST SPEEDS ACROSS THE SOUTHERN HALF OF
THE LAKE. THE LOW WILL SHIFT EAST OF THE LAKE SUNDAY MORNING
BRINGING A SHIFT TO NORTHWEST WINDS WITH SPEEDS REMAINING ELEVATED
INTO THE AFTERNOON BEFORE DROPPING OFF DURING THE EVENING AS HIGH
PRESSURE RETURNS. THIS HIGH WILL QUICKLY SHIFT EAST AS WELL WITH
STRONG LOW PRESSURE MOVING ACROSS THE CANADIAN PRAIRIES BEHIND IT.
THE PRESSURE GRADIENT WILL STRENGTHEN CONSIDERABLY ON MONDAY WITH
SOUTHWEST WINDS INCREASING THROUGH THE DAY. THE LOW WILL PASS
NORTH OF THE LAKE AND MAY DEEPEN SLIGHTLY AS IT DOES SO MONDAY
NIGHT. AS A RESULT...MID RANGE SOUTHWEST GALES ARE LOOKING MORE
LIKELY BY LATE MONDAY AFTERNOON BUT EASE TUESDAY MORNING AS THE
LOW MOVES INTO NORTHERN QUEBEC AND WEAK HIGH PRESSURE RIDGING
ARRIVES. WILL BUMP FORECAST WORDING UP TO GALES AND CARRY 40 KT
NORTH FOR NOW BUT THERE IS SOME POTENTIAL TO BE CLOSER TO 45 KT
FOR AT LEAST A SHORT TIME MONDAY EVENING IF THE LOW DEEPENS
SUFFICIENTLY. WINDS SHOULD BE CLOSER TO 30-35 KT SOUTH. BEYOND
THAT CONFIDENCE LOWERS BUT THE PATTERN LOOKS TO REMAIN ACTIVE WITH
ANOTHER LOW PASSING NORTH OF THE LAKE TUESDAY NIGHT. THE SOUTHERN
STREAM OF FLOW LOOKS TO BECOME MORE ACTIVE AND LOW PRESSURE MAY
MOVE UP FROM THE SOUTHWEST LATE NEXT WEEK.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1055 AM MST SAT JAN 5 2013
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 236 AM MST SAT JAN 5 2013
04Z WATER VAPOR IMAGERY AND RAP ANALYSIS INDICATED UPPER LEVEL LOW
CIRCULATION CENTERED OVER THE OKLAHOMA PANHANDLE MOVING
NORTHEAST...WITH A SECOND SHORT WAVE TROUGH DIVING TO THE SOUTHEAST
ACROSS THE NORTHERN PLAINS. FOR THE MOST PART...00Z SOUNDINGS HAD
WARMED AND DRIED FROM 24 HOURS AGO WITH THE ONLY EXCEPTION BEING
H75-H5 MOISTENING AT DDC IN ADVANCE OF SOUTHERN LOW. MOISTENING WAS
LIMITED TO THIS LEVEL HOWEVER...WITH LARGE SUB CLOUD DRY LATER
NOTED.
TODAY-SUNDAY...TROUGH TO THE SOUTH WILL GRADUALLY LIFT TO THE
NORTHEAST THIS MORNING AS NEXT SYSTEM APPROACHES FROM THE NORTH.
WHILE THERE IS A BIT OF ASCENT EXPECTED...SYSTEMS FOR THE MOST PART
DO NOT BRING ANY MEANINGFUL INFLUX OF MOISTURE TO THE AREA. WITH
OBSERVED SOUNDINGS AROUND THE AREA INDICATING VERY DRY
CONDITIONS...ESPECIALLY BELOW H7...LEADS ME TO THINK DEPARTING
SYSTEM WILL LEAD TO MUCH MORE THAN A PERIOD OF MID CLOUDS...ALTHOUGH
WILL MONITOR. SYSTEM APPROACHING FROM THE NORTH WILL HAVE SIMILAR
MOISTURE AVAILABILITY ISSUES DURING THE AFTERNOON AS IT MOVES ACROSS
THE AREA. MAIN CONCERN WITH THIS SECOND SYSTEM WILL BE THE SHARP
INCREASE IN WIND SPEEDS OFF OF THE SURFACE...ESPECIALLY AS
SUBSIDENCE INCREASES IN THE AFTERNOON. HAVE BUMPED UP THE WINDS INTO
THE 15 TO 25 MPH CATEGORY FOR THE TIME BEING...AS THE LINGERING
IMPACT OF SNOW COVER MAKES CONFIDENCE IN DEEP MIXING TOO LOW TO
BRING DOWN HIGHER SPEEDS. STRONG SUBSIDENCE WILL OVERSPREAD THE AREA
TONIGHT AS SHORT WAVE RIDGE MOVES OVER THE AREA. THIS WILL LEAD TO
CONTINUED DRY AND MOSTLY CLEAR CONDITIONS THROUGH SUNDAY MORNING
BEFORE CLOUDS BEGIN TO INCREASE LATE IN THE AFTERNOON AS RIDGE
SHIFTS TO THE EAST OF THE AREA. OVERALL CURRENT FORECAST LOOKS
REASONABLE CONSIDERING LATEST SUITE OF DATA AND ONLY MADE A FEW
MINOR CHANGES TO TEMPS.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 236 AM MST SAT JAN 5 2013
SUNDAY NIGHT-MONDAY NIGHT...H5 TROUGH WILL SPLIT INTO A NORTHERN AND
SOUTHERN SYSTEM OVER THE WESTERN CONUS WITH GOOD MODEL AGREEMENT
THAT SOUTHERN TROUGH WILL DIVE TO THE SOUTH ALONG THE US/MEXICO
BORDER AND REMAINING WELL TO THE SOUTH OF THE AREA WHILE NORTHERN
TROUGH MOVES ACROSS THE NORTHERN PLAINS. WITH THE EXPECTED TRACK OF
THE UPPER LEVEL SYSTEMS...EXPECT DRY CONDITIONS TO CONTINUE ACROSS
THE AREA WITH NO MEANINGFUL THREAT FOR PRECIPITATION. THESE SYSTEMS
WILL STILL HAVE A SMALL IMPACT ON THE AREA AS SFC TROUGH DEEPENS ON
SUNDAY RESULTING IN SOUTHERLY WINDS INCREASING TO 15 TO 25MPH LATE
SUNDAY AFTERNOON AND REMAIN GUSTY OVERNIGHT. EXPECTING THIS TO HOLD
UP MIN TEMPERATURES SEVERAL DEGREES WITH A FEW AREAS REMAINING ABOVE
NORMAL FOR LOWS.
TUESDAY THROUGH FRIDAY...MODELS HAVE COME INTO BETTER AGREEMENT
WITH THE DEVELOPMENT/TRACK OF THE UPPER LEVEL LOW OVER THE DESERT
SOUTHWEST ON TUESDAY. MODELS HAVE THE CLOSED LOW MOVING OVER
OKLAHOMA AND NORTHERN TEXAS WEDNESDAY NIGHT. AS THE LOW MOVES
NORTH ISENTROPIC LIFT WILL DEVELOP OVER THE SOUTHEAST PART OF THE
AREA...LEADING TO SOME CHANCES FOR PRECIPITATION. AS THE CLOSED
LOW MOVES NORTHEAST THURSDAY PRECIPITATION WILL COME TO AN END.
THURSDAY ANOTHER UPPER LEVEL TROUGH WILL MOVE OVER THE
INTER-MOUNTAIN WEST TOWARD THE AREA. AHEAD OF THE UPPER LEVEL
TROUGH A COLD FRONT WILL MOVE INTO THE AREA LATE THURSDAY NIGHT.
PRECIPITATION CHANCES INCREASE BEHIND THE FRONT AS
ISENTROPIC/SYNOPTIC LIFT AND MOISTURE INCREASE. AT THIS TIME WILL
KEEP PRECIPITATION CHANCES AND MOISTURE AMOUNTS ON THE LOW END DUE TO
FAIRLY WEAK LIFT AHEAD OF THE TROUGH.
TEMPERATURES FOR THE PERIOD WILL BE NEAR NORMAL THROUGH THURSDAY.
BELOW NORMAL TEMPERATURES RETURN BEHIND THE COLD FRONT THURSDAY
NIGHT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1053 AM MST SAT JAN 5 2013
VFR CONDITIONS EXPECTED AT BOTH KGLD AND KMCK THROUGH THE TAF
PERIOD. NORTHWEST WINDS WILL OCCASIONALLY GUST TO 20KTS THROUGH
THE AFTERNOON BEHIND A WEAKENING COLD FRONT...DIMINISHING AROUND
SUNSET.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...JRM
LONG TERM...JRM/JTL
AVIATION...024
AREA FORECAST DISCUSSION
NWS GOODLAND KS
439 AM MST SAT JAN 5 2013
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 236 AM MST SAT JAN 5 2013
04Z WATER VAPOR IMAGERY AND RAP ANALYSIS INDICATED UPPER LEVEL LOW
CIRCULATION CENTERED OVER THE OKLAHOMA PANHANDLE MOVING
NORTHEAST...WITH A SECOND SHORT WAVE TROUGH DIVING TO THE SOUTHEAST
ACROSS THE NORTHERN PLAINS. FOR THE MOST PART...00Z SOUNDINGS HAD
WARMED AND DRIED FROM 24 HOURS AGO WITH THE ONLY EXCEPTION BEING
H75-H5 MOISTENING AT DDC IN ADVANCE OF SOUTHERN LOW. MOISTENING WAS
LIMITED TO THIS LEVEL HOWEVER...WITH LARGE SUB CLOUD DRY LATER
NOTED.
TODAY-SUNDAY...TROUGH TO THE SOUTH WILL GRADUALLY LIFT TO THE
NORTHEAST THIS MORNING AS NEXT SYSTEM APPROACHES FROM THE NORTH.
WHILE THERE IS A BIT OF ASCENT EXPECTED...SYSTEMS FOR THE MOST PART
DO NOT BRING ANY MEANINGFUL INFLUX OF MOISTURE TO THE AREA. WITH
OBSERVED SOUNDINGS AROUND THE AREA INDICATING VERY DRY
CONDITIONS...ESPECIALLY BELOW H7...LEADS ME TO THINK DEPARTING
SYSTEM WILL LEAD TO MUCH MORE THAN A PERIOD OF MID CLOUDS...ALTHOUGH
WILL MONITOR. SYSTEM APPROACHING FROM THE NORTH WILL HAVE SIMILAR
MOISTURE AVAILABILITY ISSUES DURING THE AFTERNOON AS IT MOVES ACROSS
THE AREA. MAIN CONCERN WITH THIS SECOND SYSTEM WILL BE THE SHARP
INCREASE IN WIND SPEEDS OFF OF THE SURFACE...ESPECIALLY AS
SUBSIDENCE INCREASES IN THE AFTERNOON. HAVE BUMPED UP THE WINDS INTO
THE 15 TO 25 MPH CATEGORY FOR THE TIME BEING...AS THE LINGERING
IMPACT OF SNOW COVER MAKES CONFIDENCE IN DEEP MIXING TOO LOW TO
BRING DOWN HIGHER SPEEDS. STRONG SUBSIDENCE WILL OVERSPREAD THE AREA
TONIGHT AS SHORT WAVE RIDGE MOVES OVER THE AREA. THIS WILL LEAD TO
CONTINUED DRY AND MOSTLY CLEAR CONDITIONS THROUGH SUNDAY MORNING
BEFORE CLOUDS BEGIN TO INCREASE LATE IN THE AFTERNOON AS RIDGE
SHIFTS TO THE EAST OF THE AREA. OVERALL CURRENT FORECAST LOOKS
REASONABLE CONSIDERING LATEST SUITE OF DATA AND ONLY MADE A FEW
MINOR CHANGES TO TEMPS.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 236 AM MST SAT JAN 5 2013
SUNDAY NIGHT-MONDAY NIGHT...H5 TROUGH WILL SPLIT INTO A NORTHERN AND
SOUTHERN SYSTEM OVER THE WESTERN CONUS WITH GOOD MODEL AGREEMENT
THAT SOUTHERN TROUGH WILL DIVE TO THE SOUTH ALONG THE US/MEXICO
BORDER AND REMAINING WELL TO THE SOUTH OF THE AREA WHILE NORTHERN
TROUGH MOVES ACROSS THE NORTHERN PLAINS. WITH THE EXPECTED TRACK OF
THE UPPER LEVEL SYSTEMS...EXPECT DRY CONDITIONS TO CONTINUE ACROSS
THE AREA WITH NO MEANINGFUL THREAT FOR PRECIPITATION. THESE SYSTEMS
WILL STILL HAVE A SMALL IMPACT ON THE AREA AS SFC TROUGH DEEPENS ON
SUNDAY RESULTING IN SOUTHERLY WINDS INCREASING TO 15 TO 25MPH LATE
SUNDAY AFTERNOON AND REMAIN GUSTY OVERNIGHT. EXPECTING THIS TO HOLD
UP MIN TEMPERATURES SEVERAL DEGREES WITH A FEW AREAS REMAINING ABOVE
NORMAL FOR LOWS.
TUESDAY THROUGH FRIDAY...MODELS HAVE COME INTO BETTER AGREEMENT
WITH THE DEVELOPMENT/TRACK OF THE UPPER LEVEL LOW OVER THE DESERT
SOUTHWEST ON TUESDAY. MODELS HAVE THE CLOSED LOW MOVING OVER
OKLAHOMA AND NORTHERN TEXAS WEDNESDAY NIGHT. AS THE LOW MOVES
NORTH ISENTROPIC LIFT WILL DEVELOP OVER THE SOUTHEAST PART OF THE
AREA...LEADING TO SOME CHANCES FOR PRECIPITATION. AS THE CLOSED
LOW MOVES NORTHEAST THURSDAY PRECIPITATION WILL COME TO AN END.
THURSDAY ANOTHER UPPER LEVEL TROUGH WILL MOVE OVER THE
INTER-MOUNTAIN WEST TOWARD THE AREA. AHEAD OF THE UPPER LEVEL
TROUGH A COLD FRONT WILL MOVE INTO THE AREA LATE THURSDAY NIGHT.
PRECIPITATION CHANCES INCREASE BEHIND THE FRONT AS
ISENTROPIC/SYNOPTIC LIFT AND MOISTURE INCREASE. AT THIS TIME WILL
KEEP PRECIPITATION CHANCES AND MOISTURE AMOUNTS ON THE LOW END DUE TO
FAIRLY WEAK LIFT AHEAD OF THE TROUGH.
TEMPERATURES FOR THE PERIOD WILL BE NEAR NORMAL THROUGH THURSDAY.
BELOW NORMAL TEMPERATURES RETURN BEHIND THE COLD FRONT THURSDAY
NIGHT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 436 AM MST SAT JAN 5 2013
VFR CONDITIONS WILL PREVAIL FOR THE NEXT 24 HOURS WITH WESTERLY
WINDS SHIFTING TO THE NORTH AND INCREASING TO 13 TO 20KTS THIS
AFTERNOON BEFORE DECREASING AFTER SUNSET.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...JRM
LONG TERM...JRM/JTL
AVIATION...JRM
AREA FORECAST DISCUSSION
NWS GOODLAND KS
237 AM MST SAT JAN 5 2013
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 236 AM MST SAT JAN 5 2013
04Z WATER VAPOR IMAGERY AND RAP ANALYSIS INDICATED UPPER LEVEL LOW
CIRCULATION CENTERED OVER THE OKLAHOMA PANHANDLE MOVING
NORTHEAST...WITH A SECOND SHORT WAVE TROUGH DIVING TO THE SOUTHEAST
ACROSS THE NORTHERN PLAINS. FOR THE MOST PART...00Z SOUNDINGS HAD
WARMED AND DRIED FROM 24 HOURS AGO WITH THE ONLY EXCEPTION BEING
H75-H5 MOISTENING AT DDC IN ADVANCE OF SOUTHERN LOW. MOISTENING WAS
LIMITED TO THIS LEVEL HOWEVER...WITH LARGE SUB CLOUD DRY LATER
NOTED.
TODAY-SUNDAY...TROUGH TO THE SOUTH WILL GRADUALLY LIFT TO THE
NORTHEAST THIS MORNING AS NEXT SYSTEM APPROACHES FROM THE NORTH.
WHILE THERE IS A BIT OF ASCENT EXPECTED...SYSTEMS FOR THE MOST PART
DO NOT BRING ANY MEANINGFUL INFLUX OF MOISTURE TO THE AREA. WITH
OBSERVED SOUNDINGS AROUND THE AREA INDICATING VERY DRY
CONDITIONS...ESPECIALLY BELOW H7...LEADS ME TO THINK DEPARTING
SYSTEM WILL LEAD TO MUCH MORE THAN A PERIOD OF MID CLOUDS...ALTHOUGH
WILL MONITOR. SYSTEM APPROACHING FROM THE NORTH WILL HAVE SIMILAR
MOISTURE AVAILABILITY ISSUES DURING THE AFTERNOON AS IT MOVES ACROSS
THE AREA. MAIN CONCERN WITH THIS SECOND SYSTEM WILL BE THE SHARP
INCREASE IN WIND SPEEDS OFF OF THE SURFACE...ESPECIALLY AS
SUBSIDENCE INCREASES IN THE AFTERNOON. HAVE BUMPED UP THE WINDS INTO
THE 15 TO 25 MPH CATEGORY FOR THE TIME BEING...AS THE LINGERING
IMPACT OF SNOW COVER MAKES CONFIDENCE IN DEEP MIXING TOO LOW TO
BRING DOWN HIGHER SPEEDS. STRONG SUBSIDENCE WILL OVERSPREAD THE AREA
TONIGHT AS SHORT WAVE RIDGE MOVES OVER THE AREA. THIS WILL LEAD TO
CONTINUED DRY AND MOSTLY CLEAR CONDITIONS THROUGH SUNDAY MORNING
BEFORE CLOUDS BEGIN TO INCREASE LATE IN THE AFTERNOON AS RIDGE
SHIFTS TO THE EAST OF THE AREA. OVERALL CURRENT FORECAST LOOKS
REASONABLE CONSIDERING LATEST SUITE OF DATA AND ONLY MADE A FEW
MINOR CHANGES TO TEMPS.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 236 AM MST SAT JAN 5 2013
SUNDAY NIGHT-MONDAY NIGHT...H5 TROUGH WILL SPLIT INTO A NORTHERN AND
SOUTHERN SYSTEM OVER THE WESTERN CONUS WITH GOOD MODEL AGREEMENT
THAT SOUTHERN TROUGH WILL DIVE TO THE SOUTH ALONG THE US/MEXICO
BORDER AND REMAINING WELL TO THE SOUTH OF THE AREA WHILE NORTHERN
TROUGH MOVES ACROSS THE NORTHERN PLAINS. WITH THE EXPECTED TRACK OF
THE UPPER LEVEL SYSTEMS...EXPECT DRY CONDITIONS TO CONTINUE ACROSS
THE AREA WITH NO MEANINGFUL THREAT FOR PRECIPITATION. THESE SYSTEMS
WILL STILL HAVE A SMALL IMPACT ON THE AREA AS SFC TROUGH DEEPENS ON
SUNDAY RESULTING IN SOUTHERLY WINDS INCREASING TO 15 TO 25MPH LATE
SUNDAY AFTERNOON AND REMAIN GUSTY OVERNIGHT. EXPECTING THIS TO HOLD
UP MIN TEMPERATURES SEVERAL DEGREES WITH A FEW AREAS REMAINING ABOVE
NORMAL FOR LOWS.
TUESDAY THROUGH FRIDAY...MODELS HAVE COME INTO BETTER AGREEMENT
WITH THE DEVELOPMENT/TRACK OF THE UPPER LEVEL LOW OVER THE DESERT
SOUTHWEST ON TUESDAY. MODELS HAVE THE CLOSED LOW MOVING OVER
OKLAHOMA AND NORTHERN TEXAS WEDNESDAY NIGHT. AS THE LOW MOVES
NORTH ISENTROPIC LIFT WILL DEVELOP OVER THE SOUTHEAST PART OF THE
AREA...LEADING TO SOME CHANCES FOR PRECIPITATION. AS THE CLOSED
LOW MOVES NORTHEAST THURSDAY PRECIPIATION WILL COME TO AN END.
THURSDAY ANOTHER UPPER LEVEL TROUGH WILL MOVE OVER THE
INTER-MOUNTAIN WEST TOWARD THE AREA. AHEAD OF THE UPPER LEVEL
TROUGH A COLD FRONT WILL MOVE INTO THE AREA LATE THURSDAY NIGHT.
PRECIPITATION CHANCES INCREASE BEHIND THE FRONT AS
ISENTROPIC/SYNOPIC LIFT AND MOISTURE INCREASE. AT THIS TIME WILL
KEEP PRECIPIATION CHANCES AND MOISTURE AMOUNTS ON THE LOW END DUE TO
FAIRLY WEAK LIFT AHEAD OF THE TROUGH.
TEMPERATURES FOR THE PERIOD WILL BE NEAR NORMAL THROUGH THURSDAY.
BELOW NORMAL TEMPERATURES RETURN BEHIND THE COLD FRONT THURSDAY
NIGHT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1010 PM MST FRI JAN 4 2013
VFR THROUGH THE PERIOD AT KGLD AND KMCK. SFC TROUGH MOVES THROUGH
SHORTLY AFTER AROUND 06Z BRINGING NORTHWEST WINDS AROUND 10KTS.
THESE WINDS WILL BECOME GUSTY DURING THE DAY SATURDAY WITH
25-30KTS POSSIBLE. CLOUDINESS THROUGH MORNING GENERALLY AT CIRRUS
LEVEL WITH SOME CLOUDS AROUND 7K AND 12K FEET AT KMCK DURING THE
AFTERNOON.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...JRM
LONG TERM...JRM/JTL
AVIATION...99
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1202 AM CST SAT JAN 5 2013
...UPDATE TO SYNOPSIS...
.SYNOPSIS...
ISSUED AT 1200 AM CST SAT JAN 5 2013
WV IMAGERY AND 00Z UPPER AIR ANALYSIS INDICATE A CLOSED OFF UPPER
LEVEL LOW LIFTING NORTHEAST ACROSS THE TEXAS PANHANDLE. MEANWHILE,
A FAIRLY WEAK FLOW ALOFT PERSISTS ACROSS WESTERN KANSAS. NEAR THE
SURFACE, A LEE SIDE TROUGH OF LOW PRESSURE IN EASTERN COLORADO IS
PUSHING SLOWLY EASTWARD TOWARD THE KANSAS BORDER. SURFACE DEWPOINTS
ARE MAINLY IN THE 20S(F) ACROSS SOUTHWEST AND SOUTH CENTRAL KANSAS
WITH A FEW TEENS(F) ACROSS WEST CENTRAL KANSAS.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 254 PM CST FRI JAN 4 2013
THE UPPER LOW IS PROGGED BY THE MODELS TO MOVE FROM NEW MEXICO THIS
AFTERNOON THROUGH THE TEXAS PANHANDLE INTO EASTERN KANSAS BY
SATURDAY AFTERNOON. MODEL SOUNDINGS MOISTEN UP IN THE MID LEVELS
ACROSS SOUTH CENTRAL KANSAS THIS EVENING AND START TO MOISTEN
DOWNWARD WITH TIME. THE MODELS CONTINUE TO BE SKIMPY ON QPF WITH
THIS SYSTEM WHICH MAKES SENSE GIVEN THE LIMITED MOISTURE. THINK
THAT THERE COULD AT LEAST BE SOME FLURRIES FOR A PERIOD OF TIME
TONIGHT AND HAVE ADDED THAT TO THE GRIDS IN SOUTH CENTRAL KANSAS.
SURFACE WINDS WERE GRADUALLY VEERING WITH TIME THIS AFTERNOON AS THE
EASTERN COLORADO TROUGH DEEPENS IN ADVANCE OF THE UPPER WAVE. THIS
WILL ALLOW WEAK LOW LEVEL MOIST ADVECTION TO OCCUR OVER SOUTHWEST
KANSAS THIS EVENING. WITH THE MOISTURE RIDING UP OVER SNOW COVERED
GROUND, WE SHOULD SEE SOME FOG DEVELOP LATER THIS EVENING AND
CONTINUING THROUGH TONIGHT. MOS OUTPUT IS NOT INDICATING ANY
REDUCTION IN VISIBILITY AT ALL TONIGHT AND THE HRRR MODEL DOES NOT
INDICATE MUCH EITHER BEFORE 08Z. THE SREF PROBABILITIES DO SHOW SOME
INCREASED CHANCES FOR FOG SO WILL CONTINUE THE TREND OF SOME AREAS
OF FOG DEVELOPING. WILL ALSO START THE AREAS OF FOG FARTHER WEST
TOWARD GARDEN CITY AND SYRACUSE LATE THIS EVENING. FOR NOW WILL
HOLD OFF ON ANY HEADLINES AND LET THE NEXT SHIFT MAKE THAT
ASSESSMENT.
ON SATURDAY THE ANY LINGERING FOG IN THE EARLY MORNING SHOULD
DISSIPATE OR MOVE EAST OUT OF CENTRAL KANSAS AS THE SURFACE TROUGH
CONTINUES EAST. THE REMAINDER OF THE DAY SHOULD SEE MAINLY SUNNY
SKIES. WITH A LITTLE BETTER MIXING THAN TODAY, HIGH TEMPERATURES
SHOULD BE ABLE TO CLIMB INTO THE 30S OVER THE SNOW COVERED AREAS
WITH LOWER TO MIDDLE 40S IN SOUTH CENTRAL KANSAS WHERE THE SNOW HAS
MELTED.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 227 PM CST FRI JAN 4 2013
A WEAK, UPPER LEVEL HIGH PRESSURE RIDGE OVER THE PLAINS SUNDAY AND
INTO MONDAY WILL START TO BREAK DOWN BY LATE TUESDAY, AS A LARGE
UPPER LEVEL LOW PRESSURE SYSTEM APPROACHES FROM THE SOUTHWEST.
BOTH SUNDAY AND MONDAY WILL BE WARMER THAN IT HAS BEEN RECENTLY,
AND PLENTY OF SUNSHINE SHOULD HELP MELT MORE OF THE SNOW COVER.
HIGHS SUNDAY, MONDAY AND TUESDAY WILL RANGE FROM AROUND THE 40F
DEGREE NORTH OF THE I-70, TO THE MID TO UPPER 40S ALONG AND NEAR
THE OKLAHOMA BORDER. THEN ON TUESDAY NIGHT, SYNOPTIC SCALE LIFT
WILL RESULT FROM THE CLOSED LOW APPROACHING FROM THE SOUTHWEST.
MOISTURE WILL BE DEEPENING AND ADVECTING NORTH INTO SOUTHWESTERN
KANSAS, AND ESPECIALLY SOUTH CENTRAL KANSAS. THAT UPPER SYSTEM
WILL CONTINUE TO MARCH INTO THE TEXAS PANHANDLE BY 09/18Z OR WED
AFTERNOON, WHERE IT WILL THEN BEGIN TO LIFT NORTHEAST AND START TO
OPEN UP AS A WAVE, AT THE SAME TIME. AS FOR PRECIPITATION, THE
GOING 20 TO 30 PERCENT OF PRECIPITATION CHANCES, BASICALLY
SOUTHEAST OF A LIBERAL TO PRATT LINE, THROUGH WED/12Z SEEM
REASONABLE. THEN AS THE UPPER LOW LIFTS NORTHEAST LATE WEDNESDAY
INTO EASTERN KANSAS, 20(WEST) TO 35 (EAST) PRECIPITATION CHANCES
WEDNESDAY AFTERNOON AND NIGHT ACROSS ALL OF SOUTHWESTERN KANSAS
ALSO SEEM APPROPRIATE. PRECIPITATION TYPE WILL VARY FROM RAIN OR
SNOW IN THE DAY TIMES AND LIGHT SNOW IN THE NIGHT TIMES. AS THE
UPPER SYSTEM LIFTS OUT WEDNESDAY NIGHT, IT SHOULD ACCELERATE, AND
CHANCES FOR PRECIPITATION WILL QUICKLY END LATE WEDNESDAY NIGHT OR
VERY EARLY THURSDAY MORNING. AS THIS OCCURS, THERE WILL BE
CLEARING AND COOLING THURSDAY. A LITTLE WRAP-AROUND COLD AIR WILL
FILTER BACK INTO THE SOUTHWESTERN KANSAS FRIDAY, AND A LITTLE
LIGHT SNOW MAY DEVELOP. LOWER 20 PERCENT CHANCES FOR LIGHT SNOW
EXIST FOR FRIDAY.
WEDNESDAY AND THURSDAY LOOK TO WARM INTO THE LOWER TO MIDDLE 40S
NORTH OF JETMORE, AND AROUND 50F DEGREES SOUTH OF THE JETMORE-DODGE
CITY AREAS. ON FRIDAY, IT WILL COOL OFF TO HIGHS IN THE 30S.
MINIMUM TEMPERATURES WILL START OUT COLD SATURDAY MORNING, IN THE
TEENS OVER THE SNOW PACKED AREAS NORTHWEST OF A WAKEENEY TO GARDEN
CITY TO ELKHART LINE, AND RANGE TO THE MID 20S IN THE COLDWATER AND
MEDICINE LODGE AREAS. MEDIUM RANGE MODELS WARM MINIMUMS TO AROUND
THE 20F DEGREE MARK IN THE SCOTT CITY AREA BY TUESDAY, AND TO NEAR
30F DEGREES IN THE PRATT AREA. THE SLIGHT WARMING TREND WILL EXTEND
INTO THURSDAY MORNING, WITH LOWS FROM THE MID 20S IN SYRACUSE AND
SCOTT CITY, RANGING TO THE LOWER 30S IN PRATT, KIOWA AND COLDWATER.
MINIMUMS FRIDAY WILL TURN COOLER FROM AROUND 20F DEGREES IN THE KEARNY
COUNTY AREA TO THE UPPER 20S IN THE BARBER COUNTY AREA. SATURDAY
MORNING (DAY 8) SHOULD BE EVEN COLDER.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1100 PM CST FRI JAN 4 2013
VFR CONDITIONS ARE EXPECTED TO CONTINUE AT ALL TAF SITES
OVERNIGHT. HOWEVER, LIGHT SOUTHERLY WINDS AND HIGH RELATIVE
HUMIDITIES MAY ALLOW FOR THE DEVELOPMENT OF LOW LEVEL STRATUS
AROUND DAYBREAK FROM THE TEXAS PANHANDLE NORTHWARD INTO PORTIONS
OF SOUTHWEST KANSAS...POTENTIALLY AFFECTING KDDC AND KGCK.
MVFR/IFR CIGS AND VSBYS MAY BE POSSIBLE BRIEFLY AT KDDC...AND
ALTHOUGH LESS LIKELY...KGCK GENERALLY AFTER 10Z TO 12Z. OTHERWISE,
VFR CONDITIONS WILL DOMINATE THROUGH THE DAY SATURDAY. AS FOR
WINDS, A SURFACE TROUGH OF LOW PRESSURE IN EASTERN COLORADO WILL
EDGE SLOWLY EASTWARD ACROSS WESTERN KANSAS EARLY SATURDAY MORNING.
THIS WILL RESULT IN LIGHT SOUTHWESTERLY WINDS BECOMING
NORTHWESTERLY 10 TO 20KT BY SATURDAY EARLY AFTERNOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 38 16 43 20 / 0 0 0 0
GCK 36 13 42 18 / 0 0 0 0
EHA 41 16 45 22 / 0 0 0 0
LBL 39 14 45 19 / 0 0 0 0
HYS 35 16 37 18 / 0 0 0 0
P28 42 20 44 21 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JJOHNSON
SHORT TERM...GERARD
LONG TERM...BURKE
AVIATION...JJOHNSON
AREA FORECAST DISCUSSION
NWS WICHITA KS
1136 PM CST FRI JAN 4 2013
.AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
UPPER LOW WILL PROGRESS NORTHEAST OVER THE REGION
TONIGHT...SPREADING DENSE LOW TO MID LEVEL CLOUDS ACROSS THE AREA.
COULD SEE A FEW AREAS OF LIGHT SNOW/FLURRIES ESPECIALLY OVER KCNU
LATE TONIGHT THROUGH EARLY SATURDAY...WITH A FEW FLURRIES NOT
COMPLETELY OUT OF THE PICTURE FOR ALL OTHER SITES...BUT SCENARIO
NOT LOOKING AS FAVORABLE AS PREVIOUS FORECASTS. OTHERWISE...LOW
VFR CIGS AROUND 3000-4000 FT AGL WILL LIKELY MOVE INTO KICT-KCNU
AND MAYBE KHUT BY 08-10 UTC...PERSISTING INTO SATURDAY
MORNING...LONGEST FOR KCNU. A WEAK WIND SHIFT WILL PASS ACROSS THE
REGION SATURDAY...SWITCHING WINDS FROM SOUTHWESTERLY TO
WEST/NORTHWESTERLY BY AFTERNOON.
ADK
&&
.PREV DISCUSSION... /ISSUED 1002 PM CST FRI JAN 4 2013/
UPDATE...
SNOW CHANCES NOT LOOKING AS GOOD OVERNIGHT DUE TO DRY SUB-CLOUD
LAYER AND LIMITED MOISTURE. LATEST EVENING SOUNDINGS ARE QUITE
DRY...AND PRECIPITATION NEAR/UNDER THE UPPER LOW OVER WESTERN KS
AND THE PANHANDLES OF OK/TX HAS HAD A TOUGH TIME REACHING THE
GROUND. ADDITIONALLY...LATEST RUC AND 00Z NAM HAVE BACKED OFF ON
PRECIPITATION AMOUNTS...WITH THE GREATEST 700-600MB MOISTURE
TRAJECTORIES TARGETING THE OZARKS OF AR/MO. HOWEVER...HELD ONTO
40-50 POPS OVER FAR SOUTHEAST KS FROM ABOUT 3AM--8AM...AS LATEST
HRRR CONTINUES TO SHOW SOME QPF LATER TONIGHT THROUGH EARLY
SATURDAY. ANTICIPATING NO MORE THAN A DUSTING SNOW ACCUMULATION.
THINKING PATCHY FLURRIES WILL BE POSSIBLE AS FAR WEST/NORTHWEST AS
CENTRAL KS UNDERNEATH UPPER LOW.
ADDITIONALLY...REMOVED PATCHY FOG WORDING FROM THE FORECAST...AS
SURFACE-BOUNDARY LAYER FLOW WILL LIKELY BE TOO HIGH FOR ANY FOG
FORMATION.
ADK
PREV DISCUSSION... /ISSUED 549 PM CST FRI JAN 4 2013/
AVIATION...00Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
AN UPPER LEVEL LOW WILL DRIFT NORTHEAST ACROSS THE REGION
TONIGHT...SPREADING DENSE LOW TO MID-LEVEL CLOUDS NORTHEAST.
THINKING ALL SITES WILL REMAIN VFR EXCEPT KCNU...WHERE A QUICK
SHOT OF LIGHT SNOW AND LOW MVFR OR HIGH IFR CIGS WILL BE POSSIBLE
FROM ABOUT 10-14 UTC. ANTICIPATING ACCUMULATIONS TO REMAIN UNDER
ONE-HALF INCH. FURTHER WEST ACROSS THE REST OF CENTRAL AND EASTERN
KS...PERIODIC FLURRIES CANNOT BE RULED OUT FROM ABOUT 08-14
UTC...BUT THINKING MOST AREAS WILL REMAIN PRECIPITATION-FREE DUE
TO A DRY SUB-CLOUD LAYER. OTHERWISE...CLOUDS/PRECIPITATION SHOULD
EXIT EASTERN KS BY LATE MORNING/EARLY AFTERNOON SATURDAY...WITH A
WEAK SURFACE TROUGH SHIFTING WINDS FROM SOUTHWESTERLY TO
WEST/NORTHWESTERLY IN THE AFTERNOON.
ADK
PREV DISCUSSION... /ISSUED 158 PM CST FRI JAN 4 2013/
DISCUSSION...
FORECAST CHALLENGES...LIGHT SNOW CHANCES EARLY SATURDAY MORNING
AND THEN PRECIP CHANCES AGAIN NEXT WEEK.
TONIGHT-MONDAY
UPPER LOW OVER NEW MEXICO WILL LIFT NORTHEAST ACROSS THE TEXAS
PANHANDLE EARLY TONIGHT AND ACROSS SOUTHEAST KANSAS SATURDAY
MORNING. CURRENT FORECAST LOOKS REASONABLE WITH MODEST CHANCE FOR
LIGHT QPF/SNOWS ACROSS SOUTHEAST KANSAS. SOME FLURRIES OR EVEN A
DUSTING OF LIGHT SNOW IS POSSIBLE A BIT FURTHER WEST TO I-135
CORRIDOR...THOUGH BETTER LIFT COINCIDENT WITH RELATIVELY DEEPER
TROPOSPHERIC MOISTENING SHOULD FAVOR SOMEWHAT BETTER CHANCES FOR
LIGHT SNOW ACCUMS ACROSS SOUTHEAST KANSAS. A NORTHERN STREAM UPPER
TROF WILL DIVE SOUTHEAST ACROSS THE MIDWEST SATURDAY NIGHT...WITH
DRY AND SEASONABLY MILD WEATHER EXPECTED FOR THE LATTER PORTION
OF THE WEEKEND. THE EXCEPTIONS BEING OVER THE RESIDUAL SNOW COVER
WHICH WILL KEEP TEMPERATURES A BIT COOLER MAINLY ACROSS CENTRAL
KANSAS.
TUESDAY-FRIDAY
THE MAIN CHALLENGE IN THE OUTER PERIODS CONTINUES TO REVOLVE
AROUND THE HANDLING OF THE SOUTHERN STREAM UPPER TROF MOVING
ACROSS THE SOUTHERN PLAINS NEXT WEEK. THE GFS REMAINS SOMEWHAT
MORE PROGRESSIVE WITH A BIT MORE PHASING OF ENERGY WITHIN THE
NORTHERN STREAM...WHILE THE ECMWF IS MUCH SLOWER. THIS LEADS TO
SOMEWHAT LOWER CONFIDENCE IN THE TRACK AND TIMING OF THE
ASSOCIATED SYNOPTIC FEATURES...SO WILL MAKE LITTLE CHANGE TO THE
GOING FORECAST FOR NOW. THERE DOES SEEM TO BE BETTER CONTINUITY
AND CONFIDENCE IN DEVELOPING A MEAN LONGWAVE UPPER TROF ACROSS
THE WEST BY THE END OF THE WEEK...ALLOWING MUCH COLDER AIR TO BE
POISED AND READY TO DROP SOUTH INTO KANSAS.
DARMOFAL
AVIATION...18Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
THE AVIATION CONCERN IS THE LOW MVFR/IFR CEILINGS AND SNOW CHANCES
FOR KCNU.
AS AN UPPER LEVEL DISTURBANCE APPROACHES THIS AFTERNOON AND
EVENING...MID LEVEL CLOUDS WILL STREAM IN FROM THE SOUTH. AFTER
SUNSET LOWER MVFR CLOUDS WILL MOVE IN IMPACTING PRIMARILY KICT AND
KCNU. SNOW SHOWERS ARE EXPECTED AT KCNU TOWARDS THE MORNING
HOURS...AND HAVE REDUCED VISIBILITIES AND CEILINGS TO IFR RANGE.
VFR CONDITIONS ARE EXPECTED THROUGH THE AFTERNOON AND EARLY
OVERNIGHT HOURS AT ALL TERMINALS UNTIL THOSE LOWER MVFR CEILINGS
MOVE IN. WINDS WILL STAY RELATIVELY LIGHT AND OUT OF THE
SOUTH/SOUTHWEST. TOWARD THE END OF THIS 24 HOUR VALID PERIOD...A
FRONT WILL BEGIN TO MOVE THROUGH THE AREA...CHANGING THE WINDS
AROUND TO THE NORTHWEST...THIS SHOULD IMPACT KRSL BY 15-16Z TOMORROW
AND BEGIN TO IMPACT KSLN BY 18Z.
BILLINGS
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 26 43 20 44 / 10 10 0 0
HUTCHINSON 24 41 17 42 / 10 10 0 0
NEWTON 25 40 18 40 / 10 10 0 0
ELDORADO 26 41 21 42 / 20 20 0 0
WINFIELD-KWLD 28 45 21 45 / 20 20 0 0
RUSSELL 16 35 13 38 / 10 10 0 0
GREAT BEND 19 36 13 38 / 10 10 0 0
SALINA 21 38 15 39 / 10 10 0 0
MCPHERSON 23 39 16 40 / 10 10 0 0
COFFEYVILLE 29 46 22 40 / 40 40 0 0
CHANUTE 27 44 20 39 / 40 40 0 0
IOLA 27 43 20 39 / 40 40 0 0
PARSONS-KPPF 28 45 21 40 / 40 40 0 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1112 PM CST FRI JAN 4 2013
...UPDATE TO AVIATION...
.SYNOPSIS...
ISSUED AT 254 PM CST FRI JAN 4 2013
THE 12Z UPPER AIR ANALYSIS SHOWED A CLOSED LOW AT 500 MB SPINNING
OVER NEW MEXICO THIS MORNING. THE ANALYSIS SHOWS THAT THIS SYSTEM
DOES NOT HAVE A LOT OF MOISTURE TO WORK WITH BUT SATELLITE IMAGERY
SHOWED MID AND HIGH LEVEL CLOUDINESS AHEAD OF THIS SYSTEM SPREADING
UP TOWARD SOUTHWEST KANSAS THIS AFTERNOON. IN THE LOWER LEVELS, A
RIDGE OF HIGH PRESSURE AT 850 MB EXTENDED FROM SOUTHEAST TEXAS BACK
INTO THE FOUR CORNERS REGION. AT THE SURFACE, A LOW PRESSURE TROUGH
WAS SLOWLY DEEPENING OVER EASTERN COLORADO. SURFACE DEWPOINTS WERE
GENERALLY IN THE TEENS OVER SOUTHWEST KANSAS WHILE FARTHER SOUTH,
OVER THE TEXAS PANHANDLE INTO WESTERN OKLAHOMA, DEWPOINTS WERE IN
THE LOWER TO MIDDLE 20S.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 254 PM CST FRI JAN 4 2013
THE UPPER LOW IS PROGGED BY THE MODELS TO MOVE FROM NEW MEXICO THIS
AFTERNOON THROUGH THE TEXAS PANHANDLE INTO EASTERN KANSAS BY
SATURDAY AFTERNOON. MODEL SOUNDINGS MOISTEN UP IN THE MID LEVELS
ACROSS SOUTH CENTRAL KANSAS THIS EVENING AND START TO MOISTEN
DOWNWARD WITH TIME. THE MODELS CONTINUE TO BE SKIMPY ON QPF WITH
THIS SYSTEM WHICH MAKES SENSE GIVEN THE LIMITED MOISTURE. THINK
THAT THERE COULD AT LEAST BE SOME FLURRIES FOR A PERIOD OF TIME
TONIGHT AND HAVE ADDED THAT TO THE GRIDS IN SOUTH CENTRAL KANSAS.
SURFACE WINDS WERE GRADUALLY VEERING WITH TIME THIS AFTERNOON AS THE
EASTERN COLORADO TROUGH DEEPENS IN ADVANCE OF THE UPPER WAVE. THIS
WILL ALLOW WEAK LOW LEVEL MOIST ADVECTION TO OCCUR OVER SOUTHWEST
KANSAS THIS EVENING. WITH THE MOISTURE RIDING UP OVER SNOW COVERED
GROUND, WE SHOULD SEE SOME FOG DEVELOP LATER THIS EVENING AND
CONTINUING THROUGH TONIGHT. MOS OUTPUT IS NOT INDICATING ANY
REDUCTION IN VISIBILITY AT ALL TONIGHT AND THE HRRR MODEL DOES NOT
INDICATE MUCH EITHER BEFORE 08Z. THE SREF PROBABILITIES DO SHOW SOME
INCREASED CHANCES FOR FOG SO WILL CONTINUE THE TREND OF SOME AREAS
OF FOG DEVELOPING. WILL ALSO START THE AREAS OF FOG FARTHER WEST
TOWARD GARDEN CITY AND SYRACUSE LATE THIS EVENING. FOR NOW WILL
HOLD OFF ON ANY HEADLINES AND LET THE NEXT SHIFT MAKE THAT
ASSESSMENT.
ON SATURDAY THE ANY LINGERING FOG IN THE EARLY MORNING SHOULD
DISSIPATE OR MOVE EAST OUT OF CENTRAL KANSAS AS THE SURFACE TROUGH
CONTINUES EAST. THE REMAINDER OF THE DAY SHOULD SEE MAINLY SUNNY
SKIES. WITH A LITTLE BETTER MIXING THAN TODAY, HIGH TEMPERATURES
SHOULD BE ABLE TO CLIMB INTO THE 30S OVER THE SNOW COVERED AREAS
WITH LOWER TO MIDDLE 40S IN SOUTH CENTRAL KANSAS WHERE THE SNOW HAS
MELTED.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 227 PM CST FRI JAN 4 2013
A WEAK, UPPER LEVEL HIGH PRESSURE RIDGE OVER THE PLAINS SUNDAY AND
INTO MONDAY WILL START TO BREAK DOWN BY LATE TUESDAY, AS A LARGE
UPPER LEVEL LOW PRESSURE SYSTEM APPROACHES FROM THE SOUTHWEST.
BOTH SUNDAY AND MONDAY WILL BE WARMER THAN IT HAS BEEN RECENTLY,
AND PLENTY OF SUNSHINE SHOULD HELP MELT MORE OF THE SNOW COVER.
HIGHS SUNDAY, MONDAY AND TUESDAY WILL RANGE FROM AROUND THE 40F
DEGREE NORTH OF THE I-70, TO THE MID TO UPPER 40S ALONG AND NEAR
THE OKLAHOMA BORDER. THEN ON TUESDAY NIGHT, SYNOPTIC SCALE LIFT
WILL RESULT FROM THE CLOSED LOW APPROACHING FROM THE SOUTHWEST.
MOISTURE WILL BE DEEPENING AND ADVECTING NORTH INTO SOUTHWESTERN
KANSAS, AND ESPECIALLY SOUTH CENTRAL KANSAS. THAT UPPER SYSTEM
WILL CONTINUE TO MARCH INTO THE TEXAS PANHANDLE BY 09/18Z OR WED
AFTERNOON, WHERE IT WILL THEN BEGIN TO LIFT NORTHEAST AND START TO
OPEN UP AS A WAVE, AT THE SAME TIME. AS FOR PRECIPITATION, THE
GOING 20 TO 30 PERCENT OF PRECIPITATION CHANCES, BASICALLY
SOUTHEAST OF A LIBERAL TO PRATT LINE, THROUGH WED/12Z SEEM
REASONABLE. THEN AS THE UPPER LOW LIFTS NORTHEAST LATE WEDNESDAY
INTO EASTERN KANSAS, 20(WEST) TO 35 (EAST) PRECIPITATION CHANCES
WEDNESDAY AFTERNOON AND NIGHT ACROSS ALL OF SOUTHWESTERN KANSAS
ALSO SEEM APPROPRIATE. PRECIPITATION TYPE WILL VARY FROM RAIN OR
SNOW IN THE DAY TIMES AND LIGHT SNOW IN THE NIGHT TIMES. AS THE
UPPER SYSTEM LIFTS OUT WEDNESDAY NIGHT, IT SHOULD ACCELERATE, AND
CHANCES FOR PRECIPITATION WILL QUICKLY END LATE WEDNESDAY NIGHT OR
VERY EARLY THURSDAY MORNING. AS THIS OCCURS, THERE WILL BE
CLEARING AND COOLING THURSDAY. A LITTLE WRAP-AROUND COLD AIR WILL
FILTER BACK INTO THE SOUTHWESTERN KANSAS FRIDAY, AND A LITTLE
LIGHT SNOW MAY DEVELOP. LOWER 20 PERCENT CHANCES FOR LIGHT SNOW
EXIST FOR FRIDAY.
WEDNESDAY AND THURSDAY LOOK TO WARM INTO THE LOWER TO MIDDLE 40S
NORTH OF JETMORE, AND AROUND 50F DEGREES SOUTH OF THE JETMORE-DODGE
CITY AREAS. ON FRIDAY, IT WILL COOL OFF TO HIGHS IN THE 30S.
MINIMUM TEMPERATURES WILL START OUT COLD SATURDAY MORNING, IN THE
TEENS OVER THE SNOW PACKED AREAS NORTHWEST OF A WAKEENEY TO GARDEN
CITY TO ELKHART LINE, AND RANGE TO THE MID 20S IN THE COLDWATER AND
MEDICINE LODGE AREAS. MEDIUM RANGE MODELS WARM MINIMUMS TO AROUND
THE 20F DEGREE MARK IN THE SCOTT CITY AREA BY TUESDAY, AND TO NEAR
30F DEGREES IN THE PRATT AREA. THE SLIGHT WARMING TREND WILL EXTEND
INTO THURSDAY MORNING, WITH LOWS FROM THE MID 20S IN SYRACUSE AND
SCOTT CITY, RANGING TO THE LOWER 30S IN PRATT, KIOWA AND COLDWATER.
MINIMUMS FRIDAY WILL TURN COOLER FROM AROUND 20F DEGREES IN THE KEARNY
COUNTY AREA TO THE UPPER 20S IN THE BARBER COUNTY AREA. SATURDAY
MORNING (DAY 8) SHOULD BE EVEN COLDER.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1100 PM CST FRI JAN 4 2013
VFR CONDITIONS ARE EXPECTED TO CONTINUE AT ALL TAF SITES
OVERNIGHT. HOWEVER, LIGHT SOUTHERLY WINDS AND HIGH RELATIVE
HUMIDITIES MAY ALLOW FOR THE DEVELOPMENT OF LOW LEVEL STRATUS
AROUND DAYBREAK FROM THE TEXAS PANHANDLE NORTHWARD INTO PORTIONS
OF SOUTHWEST KANSAS...POTENTIALLY AFFECTING KDDC AND KGCK.
MVFR/IFR CIGS AND VSBYS MAY BE POSSIBLE BRIEFLY AT KDDC...AND
ALTHOUGH LESS LIKELY...KGCK GENERALLY AFTER 10Z TO 12Z. OTHERWISE,
VFR CONDITIONS WILL DOMINATE THROUGH THE DAY SATURDAY. AS FOR
WINDS, A SURFACE TROUGH OF LOW PRESSURE IN EASTERN COLORADO WILL
EDGE SLOWLY EASTWARD ACROSS WESTERN KANSAS EARLY SATURDAY MORNING.
THIS WILL RESULT IN LIGHT SOUTHWESTERLY WINDS BECOMING
NORTHWESTERLY 10 TO 20KT BY SATURDAY EARLY AFTERNOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 16 38 16 43 / 0 0 0 0
GCK 14 36 13 42 / 0 0 0 0
EHA 14 41 16 45 / 0 0 0 0
LBL 16 39 14 45 / 10 0 0 0
HYS 15 35 16 37 / 0 0 0 0
P28 25 42 20 44 / 10 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...GERARD
SHORT TERM...GERARD
LONG TERM...BURKE
AVIATION...JJOHNSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1252 PM EST SAT JAN 5 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 527 AM EST SAT JAN 5 2013
WV LOOP AND 00Z RAOBS INDICATE WNW FLOW ALOFT ON PERIPHERY OF POLAR
VORTEX CENTERED OVER NUNAVUT CANADA ACROSS HUDSON BAY. COLD AIR IS
NEAR BY WITH H85 TEMPS BLO -15C OVER NORTHERN ONTARIO AND SFC TEMPS
BLO ZERO. FAIRLY MILD BY COMPARISON ACROSS UPR LAKES THOUGH AS H85
TEMPS ARE AROUND -1C. SHALLOW COLD AIR HAS ALLOWED SPOTS ALONG WI
BORDER THAT HAVE CLEAR SKIES TO DROP INTO SINGLE DIGITS ABOVE ZERO.
WARMER AIR AT H85 IS SEEN UPSTREAM OVER NORTHERN PLAINS WITH ABR AT
+4C AND MPX AT +2C. MAIN SHORTWAVE UPSTREAM IS CROSSING ALBERTA AND
SASKATCHEWAN THIS MORNING IN THE NORTHERN STREAM. ALSO IS A WAVE OVER
THE SOUTHERN PLAINS IN THE SOUTHERN STREAM. NORTHERN STREAM WAVE IS
WELL AGREED UPON BY MODELS TO SLIDE INTO NORTHERN PLAINS TODAY AND
DIG ACROSS UPPER LAKES LATE TONIGHT INTO SUNDAY MORNING AS H4-H3 JET
STREAK IN POLAR JET STREAM DIGS INTO WEST SIDE OF TROUGH. ASSOCIATED
SFC LOW IS JUST GETTING GOING OVER WESTERN NORTH DAKOTA WITH MSLP OF
1015MB. OUT AHEAD OF THE LOW TODAY...CURIOUS ON HOW WARM TEMPS WILL
GET. RAP HANDLES LOW CLOUDS WELL RIGHT NOW AND IT INDICATES PARTIAL
CLEARING OF CLOUDS OVER WEST THIS MORNING INTO EARLY AFTN...WHILE
CLOUDS HANG IN OVER KEWEEENAW AND ALSO DOWNWIND OF SW FLOW OVER LK
MICHIGAN. MIXING TO 950MB-925MB SUPPORTS HIGHS REACHING INTO THE 30S
AGAIN FOR MOST AREAS. ONLY PRECIP TODAY WOULD BE OVER EAST WHERE SOME
DRIZZLE MAY OCCUR WITH ADDITIONAL MOISTURE PROVIDED BY LK MICHIGAN.
AS TROUGH DEEPENS TONIGHT...SO TO DOES SFC LOW AS IT MOVES ACROSS LK
SUPERIOR/UPR MICHIGAN. BASED ON 1000-900MB THICKNESS
PACKING...EXPECT COLD FRONT TO DROP OVER NORTHWEST PORTION OF CWA
03Z-06Z TONIGHT AND REACH THE FAR EASTERN CWA BTWN 09Z-12Z.
SOUNDINGS FM NAM AND GFS GENERALLY SIMILAR SHOWING LOW-LEVEL
MOISTURE BUILDING UP AOA 800MB AS TROUGH DEEPENS ACROSS AREA.
MARGINALLY COLD INITIALLY EVEN AFTER FROPA WITH MOISTURE BARELY
REACHING -10C ISOTHERM. KEPT MENTION OF DRIZZLE AND/OR FREEZING
DRIZZLE THROUGH EVENING THEN AS TROUGH DEEPENS/MOISTURE DEPTH
INCREASES AND COLD AIR ADVECTION DEVELOPS /H85 TEMPS FALLING TO
AROUND -11C BY 12Z SUNDAY/ EXPECT A PERIOD OF LAKE ENHANCED SNOW
SHOWERS TO FORM. NORTH WINDS IN MOIST LAYER AND AXIS OF H85 THERMAL
TROUGH POINT TO FAR WEST AND NORTH CENTRAL CWA TO SEE MOST SNOW
TONIGHT. SINCE COLD AIR LAGS FARTHER TO THE EAST...KEPT MENTION OF
FREEZING DRIZZLE IN AT ISQ-ERY UNTIL AROUND 09Z.
USED BLEND OF HIGHER RESOLUTION GUIDANCE TO COME UP WITH QPF/SNOW
AMOUNTS FOR TONIGHT. IN GENERAL MOST OF THESE GUIDANCE SETS CAME UP
WITH AN AVERAGE OF 0.20 INCH FOR 6 HR QPF OVER HIGHER TERRAIN OF
WEST AND NORTH CENTRAL. ALSO LEANED ON LOCAL LK EFFECT GUIDANCE TO
MAKE SURE MODEL DERVIED OUTPUT WAS NOT TOO FAR OUT OF LINE. AT THE
MOST WOULD EXPECT 2-3 INCHES OF SNOW TONIGHT FOR FAVORED AREAS NEAR
LK SUPERIOR AND MAINLY LESS THAN 1 INCH OVER REST OF NORTHERN CWA.
DUE TO STRONGER NORTH WINDS IN BLYR...SNOW PROBABLY FALLS OVER SOUTH
CWA AS WELL...BUT ANY ACCUMS WILL BE MINOR. DO EXPECT TO SEE SNOW
ACCUMS REACH OVER MUCH OF GOGEBIC COUNTY...INTO FAR SOUTHERN
PORTIONS OF MARQUETTE COUNTY AND ALSO OVER NORTHERN PORTION OF DELTA
COUNTY DUE TO THOSE STRONGER WINDS. AS TROUGH DEEPENS AND DEEPER
MOISTURE EXPANDS BRIEFLY MAY SEE SNOW BECOME MORE WIDESPREAD...AT
LEAST BRIEFLY...OVER ROUGHLY EAST THIRD OF CWA WELL AFTER 06Z. THIS
COULD BOOST SNOW AMOUNTS EVEN IN NON-TRADITIONAL LK EFFECT AREAS OF
ALGER/SCHOOLCRAFT/LUCE COUNTIES.
WINDS WILL SHIFT ABRUBTLY TO THE NORTH BEHIND THE COLD FRONT. GUSTS
ALONG LK SUPERIOR FROM KEWEENAW PENINSULA TOWARD BIG BAY/MARQUETTE
AND EVENTUALLY MUNISING MAY REACH OVER 30 MPH LATE TONIGHT.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 527 AM EST SAT JAN 5 2013
AS ADVERTISED IN LATE DEC...EARLY JAN HAS STARTED ON THE QUIET SIDE
WITH REGARD TO PCPN IN THE UPPER LAKES. IT LOOKS LIKE THAT WILL
CONTINUE THRU THE FIRST HALF OF THE COMING WEEK. AS IN LATE DEC...
SPLIT FLOW PERSISTS...THOUGH THE SRN STREAM IS LESS ACTIVE AND THE
NRN STREAM IS MORE ACTIVE. IN THE NRN STREAM...A TROF CURRENTLY
DOMINATES ERN CANADA DOWNSTREAM OF RIDGING OVER WRN CANADA THAT
EXTENDS N INTO THE ARCTIC. THIS PLACES THE UPPER LAKES UNDER WNW
FLOW. OVER THE NEXT SEVERAL DAYS...THE RIDGE/TROF OVER WRN/ERN
CANADA RESPECTIVELY WILL RELAX WITH POLAR VORTEX SETTLING INTO A
POSITION NW OF HUDSON BAY. THIS WILL BRING A TRANSITION TO ZONAL
FLOW ACROSS SRN CANADA...ALLOWING MILD PACIFIC AIR TO WASH ACROSS
THE CONUS. THUS...TEMPS HERE DURING THE UPCOMING WEEK WILL BE WELL
ABOVE NORMAL FOR JAN. HEADING INTO THE LATTER PORTION OF THE WEEK...
MEDIUM RANGE GUIDANCE HAS BEEN CONSISTENTLY SUGGESTING TROF
AMPLIFICATION OVER THE WRN CONUS AS RIDGE BEGINS TO BUILD THRU THE
NE PACIFIC TOWARD AK. THIS WILL LIKELY BREAK THE RECENT DRY
PATTERN...PERHAPS AS EARLY AS MIDWEEK AS SRN STREAM ENERGY MAY BE
FORCED FAR ENOUGH N TO BRING A SHIELD OF PCPN (QUITE POSSIBLY MOSTLY
RAIN) INTO UPPER MI. FARTHER DOWN THE ROAD...THERE HAVE BEEN AND
CONTINUE TO BE HINTS FROM MEDIUM RANGE GUIDANCE THAT AT LEAST A
PORTION OF MID TO LATE JAN COULD TURN COLD AS WRN TROF SLOWLY SHIFTS
E INTO CNTRL NAMERICA. HOWEVER...THE FORECASTED MJO PHASE FAVORS
WARM WEATHER OVER THE ERN HALF OF THE CONUS DURING THAT PERIOD.
THUS...IT WILL BE INTERESTING TO SEE HOW FAR E THE TROF SHIFTS AND
HOW FAR SE AND E ARCTIC AIR MOVES. IN ANY EVENT...ASSUMING TROF DOES
MAKE SOME EASTWARD PROGRESS...POTENTIAL SHOULD BE THERE FOR AN
ACTIVE WINTER STORM TRACK FOR A TIME FROM THE SRN ROCKIES/SRN PLAINS
E AND NE INTO AREAS FROM THE MISSISSIPPI RIVER VALLEY EASTWARD.
SO...FOR THOSE LOOKING FOR SNOW FOR OUTDOOR ACTIVITIES...THERE MAY
BE A FAVORABLE WINDOW OF OPPORTUNITY DURING THE MIDDLE OF JAN IF
TROF AND COLDER AIR DON`T END UP BEING HELD TO THE W.
AS ALLUDED TO ABOVE...WARM AND MOSTLY DRY WEATHER WILL BE THE RULE
HEADING INTO THE MIDDLE OF THE COMING WEEK. CLIPPER NRN STREAM
SHORTWAVE THAT DIVES INTO THE WRN LAKES TONIGHT WILL BE QUICKLY
EXITING THE AREA SUN. SOLID HEIGHT RISES AND A CRUSHING INVERSION
DOWN TO 3KFT SUGGEST LIGHT LES OCCURRING SUN MORNING WILL END W TO E
DURING THE DAY...ENDING FIRST OVER THE W. THERE WILL BE AN
OPPORTUNITY FOR TEMPS TO PLUMMET SUN EVENING AS SFC RIDGE AND PERIOD
OF LIGHT/CALM WINDS SHIFTS QUICKLY ACROSS THE AREA. MID/HIGH SINGLE
DIGITS SHOULD GENERALLY BE THE RULE IN THE INTERIOR WITH TEMPS
SHOWING SOME RISE OVERNIGHT IN MANY LOCATIONS. LARGE TEMP BUST
POTENTIAL IS PRESENT AS THERE MAY BE ENOUGH TIME FOR TRADITIONAL
COLD SPOTS TO SLIP BLO ZERO.
GIVEN THE NOTABLY BETTER RUN-TO-RUN CONTINUITY OF THE ECMWF OVER THE
LAST SEVERAL RUNS AND GFS TRENDS TOWARD THE ECMWF...WILL LEAN
STRONGLY TOWARD THE ECMWF FOR MUCH OF THE FCST DURING THE COMING
WEEK. ANY PCPN THRU MIDWEEK WILL DEPEND ON HOW CLOSE ANY SHORTWAVES
PASS TO THE AREA IN THE ZONAL FLOW. AT THIS POINT...WITH ZONALLY
ORIENTED JET SHIFTING N OF THE AREA...PCPN CHANCES APPEAR MINIMAL
THRU MIDWEEK AS EASTWARD TRACKING SHORTWAVES SHOULD PASS N OF THE
AREA.
ON MON...TRANSITION TO ZONAL FLOW ACROSS SRN CANADA WILL BE FULLY
UNDERWAY...AND A SHORTWAVE WILL BE MOVING FROM MANITOBA IN THE
MORNING TO NRN ONTARIO IN THE AFTN. WITH LACK OF MOISTURE UNDER
ZONAL FLOW AND TRACK OF WAVE WELL TO THE N...PCPN IS NOT EXPECTED
HERE. IT SHOULD BE BREEZY/WINDY MON AS 55-65KT LOW-LEVEL JET
TRANSLATES ACROSS THE AREA. FORTUNATELY...STABILITY WILL LIMIT
MIXING DEPTH...BUT FAVORABLE TRACK OF PRES FALL MAX ACROSS NRN
ONTARIO JUST N OF LAKE SUPERIOR COULD MAKE FOR A WIND ADVY EVENT FOR
SOME LOCATIONS. SOUTHERLY WINDS FAVOR ERN ALGER/SCHOOLCRAFT/LUCE FOR
STRONGEST WINDS WITH KERY AND GRAND MARAIS ESPECIALLY FAVORED.
ELSEWHERE...DOWNSLOPE WARMING ALONG LAKE SUPERIOR MAY ENCOURAGE
DEEPER MIXING/STRONGER MOMENTUM TRANSPORT IN THOSE LOCATIONS AS
WELL. SOLID GALES EXPECTED ON LAKE SUPERIOR (GUSTS AT HIGH OBS
PLATFORMS MAY REACH STORM FORCE). GALES ALSO EXPECTED ON NRN LAKE
MI. UNDER BREEZY S/SW WINDS...HIGHS WILL TOP OUT IN THE 30S ACROSS
THE AREA AND COULD NEAR 40F IN LOCATIONS THAT SEE DOWNSLOPING.
WARMTH CONTINUES TUE AS NEXT SHORTWAVE TRACKS ACROSS CNTRL
SASKATCHEWAN TOWARD FAR NRN ONTARIO. IT WILL BE ANOTHER DAY OF WELL
ABOVE NORMAL TEMPS FOR JAN. WHILE MID/HIGH CLOUDS SHOULD KEEP
WARMING IN CHECK...STILL EXPECT HIGHS AGAIN INTO THE 30S.
ANOTHER SHORTWAVE WILL TAKE A TRACK A LITTLE FARTHER S ON WED. WHILE
THAT COULD IMPROVE THE CHC OF A LITTLE PCPN...IT`S NOT WORTHY OF A
MENTION AT THIS POINT GIVEN THE ZONAL PATTERN. WED SHOULD BE ANOTHER
DAY WITH 30S THE RULE FOR HIGH TEMPS.
THE END OF THE WEEK TURNS MORE INTERESTING. AS FLOW BUCKLES WITH WRN
TROF TAKING SHAPE THU/FRI...ATTENTION TURNS TO THE CLOSED SRN STREAM
LOW THAT WILL BE OVER SRN CA SUN AND IN THE VCNTY OF W TX WED.
ALTHOUGH WITH SOME TIMING VARIATION...THE ECMWF HAS BEEN VERY
CONSISTENT SHOWING THIS SYSTEM GETTING KICKED NE THRU THE MID
MISSISSIPPI VALLEY AND INTO THE GREAT LAKES REGION IN RESPONSE TO
THE DEEPENING WRN TROF. LOOKS LIKE PCPN...QUITE POSSIBLY ALL RAIN...
WILL SPREAD INTO UPPER MI THU. COLUMN MAY COOL JUST ENOUGH THU NIGHT
FOR PCPN TO CHANGE TO PREDOMINANTLY SNOW OVER HIGHER TERRAIN. THERE
IS STILL SUFFICIENT UNCERTAINTY IN HOW THIS SRN STREAM SYSTEM WILL
TRACK TO KEEP POPS ONLY IN THE CHC CATEGORY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1251 PM EST SAT JAN 5 2013
ALTHOUGH THE TERMINALS ACROSS UPPER MICHIGAN ARE CURRENLY VFR WITH
MOSTLY CLEAR SKIES...MVFR CIGS HAVE DEVELOPED ACROSS EASTERN UPPER
MICHIGAN DUE TO THE LOWER LEVEL MOISTURE OFF LAKE MICHIGAN. AS THE
SURFACE LOW APPROACHES FROM THE WEST THIS AFTERNOON...EXPECT THESE
CLOUDS TO EXPAND AND SPREAD WEST TO SAW. MEANWHILE...MVFR CIGS
ASSOCIATED WITH THE LOW WILL MOVE INTO CMX AND IWD LATE THIS AFTN
AND EARLY THIS EVENING. LIGHT FREEZING DRIZZLE OR LIGHT SNOW WILL
CHANGE TO ALL SNOW AS THE LOW PASSES ACROSS UPPER MI
OVERNIGHT...STARTING AT IWD AND CMX THIS EVENING...THEN AT SAW AFTER
MIDNIGHT. DUE TO UPSLOPE NORTH FLOW AT IWD AND SAW...EXPECT IFR
CONDITIONS AT THOSE LOCATIONS. IN ADDITION...GUSTY NORTH WINDS WILL
BE A CONCERN WITH SOME BLOWING SNOW POSSIBLE THROUGH SUN MORNING.
IMPROVING CONDITIONS SUN MORNING AS THE LOW DEPARTS AND DRIER AIR
MOVES IN.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 527 AM EST SAT JAN 5 2013
LOW PRESSURE SHIFTING ACROSS THE UPPER GREAT LAKES WILL RESULT IN A
COLD FRONT MOVING ACROSS LAKE SUPERIOR THIS EVENING OVER WESTERN
LAKE SUPERIOR AND BY LATE IN THE NIGHT OVER THE FAR EASTERN PORTION
OF THE LAKE. EXPECT LIGHT EAST-SOUTHEAST WINDS LESS THAN 20 KTS
AHEAD OF THE FRONT TO RAPIDLY INCREASE TO 20-30 KTS FROM THE NORTH
IN THE WAKE OF THE FRONT. GALE FORCE GUSTS ARE NOT OUT OF THE
QUESTION OVER CNTRL LK SUPERIOR AFTER MIDNIGHT DUE TO SHARP PRESSURE
RISES BUILDING IN BRIEFLY BEHIND THE LOW PRESSURE/COLD FRONT.
RIDGE OF HIGH PRES QUICKLY PASSES ACROSS THE UPPER LAKES SUN
EVENING...BRINGING A BRIEF PERIOD OF LIGHT WINDS. THEN...NEXT LOW
PRES SYSTEM TRACKING E INTO NRN ONTARIO MON WILL BRING A SUBSTANTIAL
AND RAPID INCREASE IN S TO SW WINDS ACROSS LAKE SUPERIOR LATE SUN
NIGHT/MON. ALTHOUGH STABILITY OF TEMP PROFILE WILL LIMIT MIXING TO
VERY STRONG WINDS OF 55-65KT AS LOW AS 2-3KFT ABOVE THE LAKE SFC...
FAVORABLE TRACK OF PRES FALL MAX JUST N OF LAKE SUPERIOR WILL BE AN
ENHANCING FACTOR. AT THIS POINT...SOLID MID RANGE GALES ARE EXPECTED
ACROSS THE LAKE MON. HIGH OBS PLATFORMS WILL PROBABLY SEE GUSTS
REACH STORM FORCE. GALES WILL END MON NIGHT AS LOW CONTINUES
EASTWARD AND WINDS VEER SW TO W. BY TUE AFTN...WINDS WILL BE UNDER
20KT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...ROLFSON
AVIATION...MRD
MARINE...JLA/ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
655 AM EST SAT JAN 5 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 527 AM EST SAT JAN 5 2013
WV LOOP AND 00Z RAOBS INDICATE WNW FLOW ALOFT ON PERIPHERY OF POLAR
VORTEX CENTERED OVER NUNAVUT CANADA ACROSS HUDSON BAY. COLD AIR IS
NEAR BY WITH H85 TEMPS BLO -15C OVER NORTHERN ONTARIO AND SFC TEMPS
BLO ZERO. FAIRLY MILD BY COMPARISON ACROSS UPR LAKES THOUGH AS H85
TEMPS ARE AROUND -1C. SHALLOW COLD AIR HAS ALLOWED SPOTS ALONG WI
BORDER THAT HAVE CLEAR SKIES TO DROP INTO SINGLE DIGITS ABOVE ZERO.
WARMER AIR AT H85 IS SEEN UPSTREAM OVER NORTHERN PLAINS WITH ABR AT
+4C AND MPX AT +2C. MAIN SHORTWAVE UPSTREAM IS CROSSING ALBERTA AND
SASKATCHEWAN THIS MORNING IN THE NORTHERN STREAM. ALSO IS A WAVE OVER
THE SOUTHERN PLAINS IN THE SOUTHERN STREAM. NORTHERN STREAM WAVE IS
WELL AGREED UPON BY MODELS TO SLIDE INTO NORTHERN PLAINS TODAY AND
DIG ACROSS UPPER LAKES LATE TONIGHT INTO SUNDAY MORNING AS H4-H3 JET
STREAK IN POLAR JET STREAM DIGS INTO WEST SIDE OF TROUGH. ASSOCIATED
SFC LOW IS JUST GETTING GOING OVER WESTERN NORTH DAKOTA WITH MSLP OF
1015MB. OUT AHEAD OF THE LOW TODAY...CURIOUS ON HOW WARM TEMPS WILL
GET. RAP HANDLES LOW CLOUDS WELL RIGHT NOW AND IT INDICATES PARTIAL
CLEARING OF CLOUDS OVER WEST THIS MORNING INTO EARLY AFTN...WHILE
CLOUDS HANG IN OVER KEWEEENAW AND ALSO DOWNWIND OF SW FLOW OVER LK
MICHIGAN. MIXING TO 950MB-925MB SUPPORTS HIGHS REACHING INTO THE 30S
AGAIN FOR MOST AREAS. ONLY PRECIP TODAY WOULD BE OVER EAST WHERE SOME
DRIZZLE MAY OCCUR WITH ADDITIONAL MOISTURE PROVIDED BY LK MICHIGAN.
AS TROUGH DEEPENS TONIGHT...SO TO DOES SFC LOW AS IT MOVES ACROSS LK
SUPERIOR/UPR MICHIGAN. BASED ON 1000-900MB THICKNESS
PACKING...EXPECT COLD FRONT TO DROP OVER NORTHWEST PORTION OF CWA
03Z-06Z TONIGHT AND REACH THE FAR EASTERN CWA BTWN 09Z-12Z.
SOUNDINGS FM NAM AND GFS GENERALLY SIMILAR SHOWING LOW-LEVEL
MOISTURE BUILDING UP AOA 800MB AS TROUGH DEEPENS ACROSS AREA.
MARGINALLY COLD INITIALLY EVEN AFTER FROPA WITH MOISTURE BARELY
REACHING -10C ISOTHERM. KEPT MENTION OF DRIZZLE AND/OR FREEZING
DRIZZLE THROUGH EVENING THEN AS TROUGH DEEPENS/MOISTURE DEPTH
INCREASES AND COLD AIR ADVECTION DEVELOPS /H85 TEMPS FALLING TO
AROUND -11C BY 12Z SUNDAY/ EXPECT A PERIOD OF LAKE ENHANCED SNOW
SHOWERS TO FORM. NORTH WINDS IN MOIST LAYER AND AXIS OF H85 THERMAL
TROUGH POINT TO FAR WEST AND NORTH CENTRAL CWA TO SEE MOST SNOW
TONIGHT. SINCE COLD AIR LAGS FARTHER TO THE EAST...KEPT MENTION OF
FREEZING DRIZZLE IN AT ISQ-ERY UNTIL AROUND 09Z.
USED BLEND OF HIGHER RESOLUTION GUIDANCE TO COME UP WITH QPF/SNOW
AMOUNTS FOR TONIGHT. IN GENERAL MOST OF THESE GUIDANCE SETS CAME UP
WITH AN AVERAGE OF 0.20 INCH FOR 6 HR QPF OVER HIGHER TERRAIN OF
WEST AND NORTH CENTRAL. ALSO LEANED ON LOCAL LK EFFECT GUIDANCE TO
MAKE SURE MODEL DERVIED OUTPUT WAS NOT TOO FAR OUT OF LINE. AT THE
MOST WOULD EXPECT 2-3 INCHES OF SNOW TONIGHT FOR FAVORED AREAS NEAR
LK SUPERIOR AND MAINLY LESS THAN 1 INCH OVER REST OF NORTHERN CWA.
DUE TO STRONGER NORTH WINDS IN BLYR...SNOW PROBABLY FALLS OVER SOUTH
CWA AS WELL...BUT ANY ACCUMS WILL BE MINOR. DO EXPECT TO SEE SNOW
ACCUMS REACH OVER MUCH OF GOGEBIC COUNTY...INTO FAR SOUTHERN
PORTIONS OF MARQUETTE COUNTY AND ALSO OVER NORTHERN PORTION OF DELTA
COUNTY DUE TO THOSE STRONGER WINDS. AS TROUGH DEEPENS AND DEEPER
MOISTURE EXPANDS BRIEFLY MAY SEE SNOW BECOME MORE WIDESPREAD...AT
LEAST BRIEFLY...OVER ROUGHLY EAST THIRD OF CWA WELL AFTER 06Z. THIS
COULD BOOST SNOW AMOUNTS EVEN IN NON-TRADITIONAL LK EFFECT AREAS OF
ALGER/SCHOOLCRAFT/LUCE COUNTIES.
WINDS WILL SHIFT ABRUBTLY TO THE NORTH BEHIND THE COLD FRONT. GUSTS
ALONG LK SUPERIOR FROM KEWEENAW PENINSULA TOWARD BIG BAY/MARQUETTE
AND EVENTUALLY MUNISING MAY REACH OVER 30 MPH LATE TONIGHT.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 527 AM EST SAT JAN 5 2013
AS ADVERTISED IN LATE DEC...EARLY JAN HAS STARTED ON THE QUIET SIDE
WITH REGARD TO PCPN IN THE UPPER LAKES. IT LOOKS LIKE THAT WILL
CONTINUE THRU THE FIRST HALF OF THE COMING WEEK. AS IN LATE DEC...
SPLIT FLOW PERSISTS...THOUGH THE SRN STREAM IS LESS ACTIVE AND THE
NRN STREAM IS MORE ACTIVE. IN THE NRN STREAM...A TROF CURRENTLY
DOMINATES ERN CANADA DOWNSTREAM OF RIDGING OVER WRN CANADA THAT
EXTENDS N INTO THE ARCTIC. THIS PLACES THE UPPER LAKES UNDER WNW
FLOW. OVER THE NEXT SEVERAL DAYS...THE RIDGE/TROF OVER WRN/ERN
CANADA RESPECTIVELY WILL RELAX WITH POLAR VORTEX SETTLING INTO A
POSITION NW OF HUDSON BAY. THIS WILL BRING A TRANSITION TO ZONAL
FLOW ACROSS SRN CANADA...ALLOWING MILD PACIFIC AIR TO WASH ACROSS
THE CONUS. THUS...TEMPS HERE DURING THE UPCOMING WEEK WILL BE WELL
ABOVE NORMAL FOR JAN. HEADING INTO THE LATTER PORTION OF THE WEEK...
MEDIUM RANGE GUIDANCE HAS BEEN CONSISTENTLY SUGGESTING TROF
AMPLIFICATION OVER THE WRN CONUS AS RIDGE BEGINS TO BUILD THRU THE
NE PACIFIC TOWARD AK. THIS WILL LIKELY BREAK THE RECENT DRY
PATTERN...PERHAPS AS EARLY AS MIDWEEK AS SRN STREAM ENERGY MAY BE
FORCED FAR ENOUGH N TO BRING A SHIELD OF PCPN (QUITE POSSIBLY MOSTLY
RAIN) INTO UPPER MI. FARTHER DOWN THE ROAD...THERE HAVE BEEN AND
CONTINUE TO BE HINTS FROM MEDIUM RANGE GUIDANCE THAT AT LEAST A
PORTION OF MID TO LATE JAN COULD TURN COLD AS WRN TROF SLOWLY SHIFTS
E INTO CNTRL NAMERICA. HOWEVER...THE FORECASTED MJO PHASE FAVORS
WARM WEATHER OVER THE ERN HALF OF THE CONUS DURING THAT PERIOD.
THUS...IT WILL BE INTERESTING TO SEE HOW FAR E THE TROF SHIFTS AND
HOW FAR SE AND E ARCTIC AIR MOVES. IN ANY EVENT...ASSUMING TROF DOES
MAKE SOME EASTWARD PROGRESS...POTENTIAL SHOULD BE THERE FOR AN
ACTIVE WINTER STORM TRACK FOR A TIME FROM THE SRN ROCKIES/SRN PLAINS
E AND NE INTO AREAS FROM THE MISSISSIPPI RIVER VALLEY EASTWARD.
SO...FOR THOSE LOOKING FOR SNOW FOR OUTDOOR ACTIVITIES...THERE MAY
BE A FAVORABLE WINDOW OF OPPORTUNITY DURING THE MIDDLE OF JAN IF
TROF AND COLDER AIR DON`T END UP BEING HELD TO THE W.
AS ALLUDED TO ABOVE...WARM AND MOSTLY DRY WEATHER WILL BE THE RULE
HEADING INTO THE MIDDLE OF THE COMING WEEK. CLIPPER NRN STREAM
SHORTWAVE THAT DIVES INTO THE WRN LAKES TONIGHT WILL BE QUICKLY
EXITING THE AREA SUN. SOLID HEIGHT RISES AND A CRUSHING INVERSION
DOWN TO 3KFT SUGGEST LIGHT LES OCCURRING SUN MORNING WILL END W TO E
DURING THE DAY...ENDING FIRST OVER THE W. THERE WILL BE AN
OPPORTUNITY FOR TEMPS TO PLUMMET SUN EVENING AS SFC RIDGE AND PERIOD
OF LIGHT/CALM WINDS SHIFTS QUICKLY ACROSS THE AREA. MID/HIGH SINGLE
DIGITS SHOULD GENERALLY BE THE RULE IN THE INTERIOR WITH TEMPS
SHOWING SOME RISE OVERNIGHT IN MANY LOCATIONS. LARGE TEMP BUST
POTENTIAL IS PRESENT AS THERE MAY BE ENOUGH TIME FOR TRADITIONAL
COLD SPOTS TO SLIP BLO ZERO.
GIVEN THE NOTABLY BETTER RUN-TO-RUN CONTINUITY OF THE ECMWF OVER THE
LAST SEVERAL RUNS AND GFS TRENDS TOWARD THE ECMWF...WILL LEAN
STRONGLY TOWARD THE ECMWF FOR MUCH OF THE FCST DURING THE COMING
WEEK. ANY PCPN THRU MIDWEEK WILL DEPEND ON HOW CLOSE ANY SHORTWAVES
PASS TO THE AREA IN THE ZONAL FLOW. AT THIS POINT...WITH ZONALLY
ORIENTED JET SHIFTING N OF THE AREA...PCPN CHANCES APPEAR MINIMAL
THRU MIDWEEK AS EASTWARD TRACKING SHORTWAVES SHOULD PASS N OF THE
AREA.
ON MON...TRANSITION TO ZONAL FLOW ACROSS SRN CANADA WILL BE FULLY
UNDERWAY...AND A SHORTWAVE WILL BE MOVING FROM MANITOBA IN THE
MORNING TO NRN ONTARIO IN THE AFTN. WITH LACK OF MOISTURE UNDER
ZONAL FLOW AND TRACK OF WAVE WELL TO THE N...PCPN IS NOT EXPECTED
HERE. IT SHOULD BE BREEZY/WINDY MON AS 55-65KT LOW-LEVEL JET
TRANSLATES ACROSS THE AREA. FORTUNATELY...STABILITY WILL LIMIT
MIXING DEPTH...BUT FAVORABLE TRACK OF PRES FALL MAX ACROSS NRN
ONTARIO JUST N OF LAKE SUPERIOR COULD MAKE FOR A WIND ADVY EVENT FOR
SOME LOCATIONS. SOUTHERLY WINDS FAVOR ERN ALGER/SCHOOLCRAFT/LUCE FOR
STRONGEST WINDS WITH KERY AND GRAND MARAIS ESPECIALLY FAVORED.
ELSEWHERE...DOWNSLOPE WARMING ALONG LAKE SUPERIOR MAY ENCOURAGE
DEEPER MIXING/STRONGER MOMENTUM TRANSPORT IN THOSE LOCATIONS AS
WELL. SOLID GALES EXPECTED ON LAKE SUPERIOR (GUSTS AT HIGH OBS
PLATFORMS MAY REACH STORM FORCE). GALES ALSO EXPECTED ON NRN LAKE
MI. UNDER BREEZY S/SW WINDS...HIGHS WILL TOP OUT IN THE 30S ACROSS
THE AREA AND COULD NEAR 40F IN LOCATIONS THAT SEE DOWNSLOPING.
WARMTH CONTINUES TUE AS NEXT SHORTWAVE TRACKS ACROSS CNTRL
SASKATCHEWAN TOWARD FAR NRN ONTARIO. IT WILL BE ANOTHER DAY OF WELL
ABOVE NORMAL TEMPS FOR JAN. WHILE MID/HIGH CLOUDS SHOULD KEEP
WARMING IN CHECK...STILL EXPECT HIGHS AGAIN INTO THE 30S.
ANOTHER SHORTWAVE WILL TAKE A TRACK A LITTLE FARTHER S ON WED. WHILE
THAT COULD IMPROVE THE CHC OF A LITTLE PCPN...IT`S NOT WORTHY OF A
MENTION AT THIS POINT GIVEN THE ZONAL PATTERN. WED SHOULD BE ANOTHER
DAY WITH 30S THE RULE FOR HIGH TEMPS.
THE END OF THE WEEK TURNS MORE INTERESTING. AS FLOW BUCKLES WITH WRN
TROF TAKING SHAPE THU/FRI...ATTENTION TURNS TO THE CLOSED SRN STREAM
LOW THAT WILL BE OVER SRN CA SUN AND IN THE VCNTY OF W TX WED.
ALTHOUGH WITH SOME TIMING VARIATION...THE ECMWF HAS BEEN VERY
CONSISTENT SHOWING THIS SYSTEM GETTING KICKED NE THRU THE MID
MISSISSIPPI VALLEY AND INTO THE GREAT LAKES REGION IN RESPONSE TO
THE DEEPENING WRN TROF. LOOKS LIKE PCPN...QUITE POSSIBLY ALL RAIN...
WILL SPREAD INTO UPPER MI THU. COLUMN MAY COOL JUST ENOUGH THU NIGHT
FOR PCPN TO CHANGE TO PREDOMINANTLY SNOW OVER HIGHER TERRAIN. THERE
IS STILL SUFFICIENT UNCERTAINTY IN HOW THIS SRN STREAM SYSTEM WILL
TRACK TO KEEP POPS ONLY IN THE CHC CATEGORY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 652 AM EST SAT JAN 5 2013
BKN MVFR CIGS GIVE WAY TO A PERIOD OF MAINLY CLEAR SKIES AFTER MID
MORNING AT CMX AND SAW. SKIES ARE ALREADY CLEAR AT IWD. EXPECT
APPROACHING LOW PRESSURE SYSTEM AND A COLD FRONT TO RESULT IN LOWER
CLOUDS AGAIN LATE TODAY THROUGH TONIGHT. CIGS INITIALLY MVFR BUT
SHOULD TREND IFR THROUGH THE EVENING. EXPECT LGT FREEZING DRIZZLE OR
SNOW THROUGH EVENING...CHANGING TO SNOW SHOWERS OVERNIGHT TONIGHT.
ONLY INCLUDED FZDZ AT IWD THIS EVENING DUE TO MORE FAVORABLE NORTH
WINDS/UPSLOPE. IFR CONDITIONS SHOULD THEN PREVAIL AT IWD AND SAW
OVERNIGHT TONIGHT AS NORTH WINDS CONTINUE. AT CMX...SINCE LOCAL
CLIMATOLOGY SUGGESTS NORTH WINDS ARE NOT AS FAVORABLE FOR PERSISTENT
LOWER CIGS/VSBY...KEPT CONDITIONS MVFR. NORTH WINDS OFF LK SUPERIOR
COULD BE GUSTY LATE TONIGHT...ESPECIALY AT SAW WHERE GUSTS MAY EXCEED
25 KTS THROUGH DAYBREAK ON SUNDAY. IMPROVING CONDITIONS DEVELOP ON
SUNDAY AT ALL THE TAF SITES WITH DIMINISHING SNOW SHOWERS AND CIGS
MAINLY MVFR TO LOWER VFR.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 527 AM EST SAT JAN 5 2013
LOW PRESSURE SHIFTING ACROSS THE UPPER GREAT LAKES WILL RESULT IN A
COLD FRONT MOVING ACROSS LAKE SUPERIOR THIS EVENING OVER WESTERN
LAKE SUPERIOR AND BY LATE IN THE NIGHT OVER THE FAR EASTERN PORTION
OF THE LAKE. EXPECT LIGHT EAST-SOUTHEAST WINDS LESS THAN 20 KTS
AHEAD OF THE FRONT TO RAPIDLY INCREASE TO 20-30 KTS FROM THE NORTH
IN THE WAKE OF THE FRONT. GALE FORCE GUSTS ARE NOT OUT OF THE
QUESTION OVER CNTRL LK SUPERIOR AFTER MIDNIGHT DUE TO SHARP PRESSURE
RISES BUILDING IN BRIEFLY BEHIND THE LOW PRESSURE/COLD FRONT.
RIDGE OF HIGH PRES QUICKLY PASSES ACROSS THE UPPER LAKES SUN
EVENING...BRINGING A BRIEF PERIOD OF LIGHT WINDS. THEN...NEXT LOW
PRES SYSTEM TRACKING E INTO NRN ONTARIO MON WILL BRING A SUBSTANTIAL
AND RAPID INCREASE IN S TO SW WINDS ACROSS LAKE SUPERIOR LATE SUN
NIGHT/MON. ALTHOUGH STABILITY OF TEMP PROFILE WILL LIMIT MIXING TO
VERY STRONG WINDS OF 55-65KT AS LOW AS 2-3KFT ABOVE THE LAKE SFC...
FAVORABLE TRACK OF PRES FALL MAX JUST N OF LAKE SUPERIOR WILL BE AN
ENHANCING FACTOR. AT THIS POINT...SOLID MID RANGE GALES ARE EXPECTED
ACROSS THE LAKE MON. HIGH OBS PLATFORMS WILL PROBABLY SEE GUSTS
REACH STORM FORCE. GALES WILL END MON NIGHT AS LOW CONTINUES
EASTWARD AND WINDS VEER SW TO W. BY TUE AFTN...WINDS WILL BE UNDER
20KT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...ROLFSON
AVIATION...JLA
MARINE...JLA/ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
529 AM EST SAT JAN 5 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 527 AM EST SAT JAN 5 2013
WV LOOP AND 00Z RAOBS INDICATE WNW FLOW ALOFT ON PERIPHERY OF POLAR
VORTEX CENTERED OVER NUNAVUT CANADA ACROSS HUDSON BAY. COLD AIR IS
NEAR BY WITH H85 TEMPS BLO -15C OVER NORTHERN ONTARIO AND SFC TEMPS
BLO ZERO. FAIRLY MILD BY COMPARISON ACROSS UPR LAKES THOUGH AS H85
TEMPS ARE AROUND -1C. SHALLOW COLD AIR HAS ALLOWED SPOTS ALONG WI
BORDER THAT HAVE CLEAR SKIES TO DROP INTO SINGLE DIGITS ABOVE ZERO.
WARMER AIR AT H85 IS SEEN UPSTREAM OVER NORTHERN PLAINS WITH ABR AT
+4C AND MPX AT +2C. MAIN SHORTWAVE UPSTREAM IS CROSSING ALBERTA AND
SASKATCHEWAN THIS MORNING IN THE NORTHERN STREAM. ALSO IS A WAVE OVER
THE SOUTHERN PLAINS IN THE SOUTHERN STREAM. NORTHERN STREAM WAVE IS
WELL AGREED UPON BY MODELS TO SLIDE INTO NORTHERN PLAINS TODAY AND
DIG ACROSS UPPER LAKES LATE TONIGHT INTO SUNDAY MORNING AS H4-H3 JET
STREAK IN POLAR JET STREAM DIGS INTO WEST SIDE OF TROUGH. ASSOCIATED
SFC LOW IS JUST GETTING GOING OVER WESTERN NORTH DAKOTA WITH MSLP OF
1015MB. OUT AHEAD OF THE LOW TODAY...CURIOUS ON HOW WARM TEMPS WILL
GET. RAP HANDLES LOW CLOUDS WELL RIGHT NOW AND IT INDICATES PARTIAL
CLEARING OF CLOUDS OVER WEST THIS MORNING INTO EARLY AFTN...WHILE
CLOUDS HANG IN OVER KEWEEENAW AND ALSO DOWNWIND OF SW FLOW OVER LK
MICHIGAN. MIXING TO 950MB-925MB SUPPORTS HIGHS REACHING INTO THE 30S
AGAIN FOR MOST AREAS. ONLY PRECIP TODAY WOULD BE OVER EAST WHERE SOME
DRIZZLE MAY OCCUR WITH ADDITIONAL MOISTURE PROVIDED BY LK MICHIGAN.
AS TROUGH DEEPENS TONIGHT...SO TO DOES SFC LOW AS IT MOVES ACROSS LK
SUPERIOR/UPR MICHIGAN. BASED ON 1000-900MB THICKNESS
PACKING...EXPECT COLD FRONT TO DROP OVER NORTHWEST PORTION OF CWA
03Z-06Z TONIGHT AND REACH THE FAR EASTERN CWA BTWN 09Z-12Z.
SOUNDINGS FM NAM AND GFS GENERALLY SIMILAR SHOWING LOW-LEVEL
MOISTURE BUILDING UP AOA 800MB AS TROUGH DEEPENS ACROSS AREA.
MARGINALLY COLD INITIALLY EVEN AFTER FROPA WITH MOISTURE BARELY
REACHING -10C ISOTHERM. KEPT MENTION OF DRIZZLE AND/OR FREEZING
DRIZZLE THROUGH EVENING THEN AS TROUGH DEEPENS/MOISTURE DEPTH
INCREASES AND COLD AIR ADVECTION DEVELOPS /H85 TEMPS FALLING TO
AROUND -11C BY 12Z SUNDAY/ EXPECT A PERIOD OF LAKE ENHANCED SNOW
SHOWERS TO FORM. NORTH WINDS IN MOIST LAYER AND AXIS OF H85 THERMAL
TROUGH POINT TO FAR WEST AND NORTH CENTRAL CWA TO SEE MOST SNOW
TONIGHT. SINCE COLD AIR LAGS FARTHER TO THE EAST...KEPT MENTION OF
FREEZING DRIZZLE IN AT ISQ-ERY UNTIL AROUND 09Z.
USED BLEND OF HIGHER RESOLUTION GUIDANCE TO COME UP WITH QPF/SNOW
AMOUNTS FOR TONIGHT. IN GENERAL MOST OF THESE GUIDANCE SETS CAME UP
WITH AN AVERAGE OF 0.20 INCH FOR 6 HR QPF OVER HIGHER TERRAIN OF
WEST AND NORTH CENTRAL. ALSO LEANED ON LOCAL LK EFFECT GUIDANCE TO
MAKE SURE MODEL DERVIED OUTPUT WAS NOT TOO FAR OUT OF LINE. AT THE
MOST WOULD EXPECT 2-3 INCHES OF SNOW TONIGHT FOR FAVORED AREAS NEAR
LK SUPERIOR AND MAINLY LESS THAN 1 INCH OVER REST OF NORTHERN CWA.
DUE TO STRONGER NORTH WINDS IN BLYR...SNOW PROBABLY FALLS OVER SOUTH
CWA AS WELL...BUT ANY ACCUMS WILL BE MINOR. DO EXPECT TO SEE SNOW
ACCUMS REACH OVER MUCH OF GOGEBIC COUNTY...INTO FAR SOUTHERN
PORTIONS OF MARQUETTE COUNTY AND ALSO OVER NORTHERN PORTION OF DELTA
COUNTY DUE TO THOSE STRONGER WINDS. AS TROUGH DEEPENS AND DEEPER
MOISTURE EXPANDS BRIEFLY MAY SEE SNOW BECOME MORE WIDESPREAD...AT
LEAST BRIEFLY...OVER ROUGHLY EAST THIRD OF CWA WELL AFTER 06Z. THIS
COULD BOOST SNOW AMOUNTS EVEN IN NON-TRADITIONAL LK EFFECT AREAS OF
ALGER/SCHOOLCRAFT/LUCE COUNTIES.
WINDS WILL SHIFT ABRUBTLY TO THE NORTH BEHIND THE COLD FRONT. GUSTS
ALONG LK SUPERIOR FROM KEWEENAW PENINSULA TOWARD BIG BAY/MARQUETTE
AND EVENTUALLY MUNISING MAY REACH OVER 30 MPH LATE TONIGHT.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 527 AM EST SAT JAN 5 2013
AS ADVERTISED IN LATE DEC...EARLY JAN HAS STARTED ON THE QUIET SIDE
WITH REGARD TO PCPN IN THE UPPER LAKES. IT LOOKS LIKE THAT WILL
CONTINUE THRU THE FIRST HALF OF THE COMING WEEK. AS IN LATE DEC...
SPLIT FLOW PERSISTS...THOUGH THE SRN STREAM IS LESS ACTIVE AND THE
NRN STREAM IS MORE ACTIVE. IN THE NRN STREAM...A TROF CURRENTLY
DOMINATES ERN CANADA DOWNSTREAM OF RIDGING OVER WRN CANADA THAT
EXTENDS N INTO THE ARCTIC. THIS PLACES THE UPPER LAKES UNDER WNW
FLOW. OVER THE NEXT SEVERAL DAYS...THE RIDGE/TROF OVER WRN/ERN
CANADA RESPECTIVELY WILL RELAX WITH POLAR VORTEX SETTLING INTO A
POSITION NW OF HUDSON BAY. THIS WILL BRING A TRANSITION TO ZONAL
FLOW ACROSS SRN CANADA...ALLOWING MILD PACIFIC AIR TO WASH ACROSS
THE CONUS. THUS...TEMPS HERE DURING THE UPCOMING WEEK WILL BE WELL
ABOVE NORMAL FOR JAN. HEADING INTO THE LATTER PORTION OF THE WEEK...
MEDIUM RANGE GUIDANCE HAS BEEN CONSISTENTLY SUGGESTING TROF
AMPLIFICATION OVER THE WRN CONUS AS RIDGE BEGINS TO BUILD THRU THE
NE PACIFIC TOWARD AK. THIS WILL LIKELY BREAK THE RECENT DRY
PATTERN...PERHAPS AS EARLY AS MIDWEEK AS SRN STREAM ENERGY MAY BE
FORCED FAR ENOUGH N TO BRING A SHIELD OF PCPN (QUITE POSSIBLY MOSTLY
RAIN) INTO UPPER MI. FARTHER DOWN THE ROAD...THERE HAVE BEEN AND
CONTINUE TO BE HINTS FROM MEDIUM RANGE GUIDANCE THAT AT LEAST A
PORTION OF MID TO LATE JAN COULD TURN COLD AS WRN TROF SLOWLY SHIFTS
E INTO CNTRL NAMERICA. HOWEVER...THE FORECASTED MJO PHASE FAVORS
WARM WEATHER OVER THE ERN HALF OF THE CONUS DURING THAT PERIOD.
THUS...IT WILL BE INTERESTING TO SEE HOW FAR E THE TROF SHIFTS AND
HOW FAR SE AND E ARCTIC AIR MOVES. IN ANY EVENT...ASSUMING TROF DOES
MAKE SOME EASTWARD PROGRESS...POTENTIAL SHOULD BE THERE FOR AN
ACTIVE WINTER STORM TRACK FOR A TIME FROM THE SRN ROCKIES/SRN PLAINS
E AND NE INTO AREAS FROM THE MISSISSIPPI RIVER VALLEY EASTWARD.
SO...FOR THOSE LOOKING FOR SNOW FOR OUTDOOR ACTIVITIES...THERE MAY
BE A FAVORABLE WINDOW OF OPPORTUNITY DURING THE MIDDLE OF JAN IF
TROF AND COLDER AIR DON`T END UP BEING HELD TO THE W.
AS ALLUDED TO ABOVE...WARM AND MOSTLY DRY WEATHER WILL BE THE RULE
HEADING INTO THE MIDDLE OF THE COMING WEEK. CLIPPER NRN STREAM
SHORTWAVE THAT DIVES INTO THE WRN LAKES TONIGHT WILL BE QUICKLY
EXITING THE AREA SUN. SOLID HEIGHT RISES AND A CRUSHING INVERSION
DOWN TO 3KFT SUGGEST LIGHT LES OCCURRING SUN MORNING WILL END W TO E
DURING THE DAY...ENDING FIRST OVER THE W. THERE WILL BE AN
OPPORTUNITY FOR TEMPS TO PLUMMET SUN EVENING AS SFC RIDGE AND PERIOD
OF LIGHT/CALM WINDS SHIFTS QUICKLY ACROSS THE AREA. MID/HIGH SINGLE
DIGITS SHOULD GENERALLY BE THE RULE IN THE INTERIOR WITH TEMPS
SHOWING SOME RISE OVERNIGHT IN MANY LOCATIONS. LARGE TEMP BUST
POTENTIAL IS PRESENT AS THERE MAY BE ENOUGH TIME FOR TRADITIONAL
COLD SPOTS TO SLIP BLO ZERO.
GIVEN THE NOTABLY BETTER RUN-TO-RUN CONTINUITY OF THE ECMWF OVER THE
LAST SEVERAL RUNS AND GFS TRENDS TOWARD THE ECMWF...WILL LEAN
STRONGLY TOWARD THE ECMWF FOR MUCH OF THE FCST DURING THE COMING
WEEK. ANY PCPN THRU MIDWEEK WILL DEPEND ON HOW CLOSE ANY SHORTWAVES
PASS TO THE AREA IN THE ZONAL FLOW. AT THIS POINT...WITH ZONALLY
ORIENTED JET SHIFTING N OF THE AREA...PCPN CHANCES APPEAR MINIMAL
THRU MIDWEEK AS EASTWARD TRACKING SHORTWAVES SHOULD PASS N OF THE
AREA.
ON MON...TRANSITION TO ZONAL FLOW ACROSS SRN CANADA WILL BE FULLY
UNDERWAY...AND A SHORTWAVE WILL BE MOVING FROM MANITOBA IN THE
MORNING TO NRN ONTARIO IN THE AFTN. WITH LACK OF MOISTURE UNDER
ZONAL FLOW AND TRACK OF WAVE WELL TO THE N...PCPN IS NOT EXPECTED
HERE. IT SHOULD BE BREEZY/WINDY MON AS 55-65KT LOW-LEVEL JET
TRANSLATES ACROSS THE AREA. FORTUNATELY...STABILITY WILL LIMIT
MIXING DEPTH...BUT FAVORABLE TRACK OF PRES FALL MAX ACROSS NRN
ONTARIO JUST N OF LAKE SUPERIOR COULD MAKE FOR A WIND ADVY EVENT FOR
SOME LOCATIONS. SOUTHERLY WINDS FAVOR ERN ALGER/SCHOOLCRAFT/LUCE FOR
STRONGEST WINDS WITH KERY AND GRAND MARAIS ESPECIALLY FAVORED.
ELSEWHERE...DOWNSLOPE WARMING ALONG LAKE SUPERIOR MAY ENCOURAGE
DEEPER MIXING/STRONGER MOMENTUM TRANSPORT IN THOSE LOCATIONS AS
WELL. SOLID GALES EXPECTED ON LAKE SUPERIOR (GUSTS AT HIGH OBS
PLATFORMS MAY REACH STORM FORCE). GALES ALSO EXPECTED ON NRN LAKE
MI. UNDER BREEZY S/SW WINDS...HIGHS WILL TOP OUT IN THE 30S ACROSS
THE AREA AND COULD NEAR 40F IN LOCATIONS THAT SEE DOWNSLOPING.
WARMTH CONTINUES TUE AS NEXT SHORTWAVE TRACKS ACROSS CNTRL
SASKATCHEWAN TOWARD FAR NRN ONTARIO. IT WILL BE ANOTHER DAY OF WELL
ABOVE NORMAL TEMPS FOR JAN. WHILE MID/HIGH CLOUDS SHOULD KEEP
WARMING IN CHECK...STILL EXPECT HIGHS AGAIN INTO THE 30S.
ANOTHER SHORTWAVE WILL TAKE A TRACK A LITTLE FARTHER S ON WED. WHILE
THAT COULD IMPROVE THE CHC OF A LITTLE PCPN...IT`S NOT WORTHY OF A
MENTION AT THIS POINT GIVEN THE ZONAL PATTERN. WED SHOULD BE ANOTHER
DAY WITH 30S THE RULE FOR HIGH TEMPS.
THE END OF THE WEEK TURNS MORE INTERESTING. AS FLOW BUCKLES WITH WRN
TROF TAKING SHAPE THU/FRI...ATTENTION TURNS TO THE CLOSED SRN STREAM
LOW THAT WILL BE OVER SRN CA SUN AND IN THE VCNTY OF W TX WED.
ALTHOUGH WITH SOME TIMING VARIATION...THE ECMWF HAS BEEN VERY
CONSISTENT SHOWING THIS SYSTEM GETTING KICKED NE THRU THE MID
MISSISSIPPI VALLEY AND INTO THE GREAT LAKES REGION IN RESPONSE TO
THE DEEPENING WRN TROF. LOOKS LIKE PCPN...QUITE POSSIBLY ALL RAIN...
WILL SPREAD INTO UPPER MI THU. COLUMN MAY COOL JUST ENOUGH THU NIGHT
FOR PCPN TO CHANGE TO PREDOMINANTLY SNOW OVER HIGHER TERRAIN. THERE
IS STILL SUFFICIENT UNCERTAINTY IN HOW THIS SRN STREAM SYSTEM WILL
TRACK TO KEEP POPS ONLY IN THE CHC CATEGORY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1249 AM EST SAT JAN 5 2013
LOW LEVEL MOISTURE ACROSS THE AREA BELOW AN INVERSION AROUND 3K FT
IS EXPECTED TO PERSIST OVERNIGHT BUT GRADUALLY DISSIPATE FROM THE
WSW LATE. MVFR CIGS AT IWD AND SAW ARE EXPECTED TO GIVE WAY TO VFR
CONDITIONS BY AROUND 09Z TO 12Z. HOWEVER...MODELS SUGGEST THAT THE
MOISTURE BAND WILL LINGER AT CMX. A SHORTWAVE AND SFC TROUGH MOVING
INTO THE REGION SATURDAY SHOULD BRING IN MVFR CIGS THAT MAY DROP
INTO THE IFR RANGE SAT EVENING. SOME LIGHT SNOW OR POSSIBLY FREEZING
DRIZZLE MAY ALSO BE POSSIBLE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 527 AM EST SAT JAN 5 2013
LOW PRESSURE SHIFTING ACROSS THE UPPER GREAT LAKES WILL RESULT IN A
COLD FRONT MOVING ACROSS LAKE SUPERIOR THIS EVENING OVER WESTERN
LAKE SUPERIOR AND BY LATE IN THE NIGHT OVER THE FAR EASTERN PORTION
OF THE LAKE. EXPECT LIGHT EAST-SOUTHEAST WINDS LESS THAN 20 KTS
AHEAD OF THE FRONT TO RAPIDLY INCREASE TO 20-30 KTS FROM THE NORTH
IN THE WAKE OF THE FRONT. GALE FORCE GUSTS ARE NOT OUT OF THE
QUESTION OVER CNTRL LK SUPERIOR AFTER MIDNIGHT DUE TO SHARP PRESSURE
RISES BUILDING IN BRIEFLY BEHIND THE LOW PRESSURE/COLD FRONT.
RIDGE OF HIGH PRES QUICKLY PASSES ACROSS THE UPPER LAKES SUN
EVENING...BRINGING A BRIEF PERIOD OF LIGHT WINDS. THEN...NEXT LOW
PRES SYSTEM TRACKING E INTO NRN ONTARIO MON WILL BRING A SUBSTANTIAL
AND RAPID INCREASE IN S TO SW WINDS ACROSS LAKE SUPERIOR LATE SUN
NIGHT/MON. ALTHOUGH STABILITY OF TEMP PROFILE WILL LIMIT MIXING TO
VERY STRONG WINDS OF 55-65KT AS LOW AS 2-3KFT ABOVE THE LAKE SFC...
FAVORABLE TRACK OF PRES FALL MAX JUST N OF LAKE SUPERIOR WILL BE AN
ENHANCING FACTOR. AT THIS POINT...SOLID MID RANGE GALES ARE EXPECTED
ACROSS THE LAKE MON. HIGH OBS PLATFORMS WILL PROBABLY SEE GUSTS
REACH STORM FORCE. GALES WILL END MON NIGHT AS LOW CONTINUES
EASTWARD AND WINDS VEER SW TO W. BY TUE AFTN...WINDS WILL BE UNDER
20KT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...ROLFSON
AVIATION...JLB
MARINE...JLA/ROLFSON
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1100 AM CST SUN JAN 6 2013
.UPDATE...
UPDATED TO INCLUDE 18Z AVIATION DISCUSSION BELOW.
&&
.DISCUSSION...
/ISSUED AT 347 AM CST SUN JAN 6 2013/
ONE THING THAT LOOKS CERTAIN IS THAT WE WILL GET A NICE JANUARY
THAW COMING UP THIS WEEK. WHERE THERE ARE STILL QUESTIONS IS HOW
WARM IS SAID THAW...AND IS IT ACCOMPANIED WITH RAIN IN THE THU/FRI
TIMEFRAME. QUESTION MARKS DO NOT GO AWAY FOR THE WEEKEND IN TERMS
OF THE WEATHER...WITH THE ONLY THING THAT LOOKS CERTAIN BY THE END
OF THE WEEK INTO NEXT WEEKEND IS THAT THE MID SECTION OF THE
COUNTRY LOOKS TO BE MORE ACTIVE.
THE THAW IS COMING...JUST NOT TODAY. SFC LOW AT 3 AM WAS NEAR THE
MACKINAC STRAIGHTS. SEEING WIDESPREAD STRATUS ACROSS NRN MN
WITHIN CYCLONIC FLOW BEHIND THIS LOW. THIS STRATUS IS MAKING
INROADS SOUTH AND SHOULD BLANKET MUCH OF NW QUARTER OF THE MPX
CWA BY DAYBREAK. FOR NOW HAVE CLOUDS THINNING DURING THE
MORNING...WITH MOSTLY SUNNY SKIES INDICATED BY THE AFTERNOON...BUT
THE RAP /PER 925-850 MB RH/ KEEPS THE CLOUDS IN PLACE THROUGH THE
DAY. CERTAINLY WOULD NOT BE THE FIRST TIME STRATUS GOT TRAPPED
UNDER A DEVELOPING INVERSION...WHICH WE WILL SEE THANKS TO 12 HR
H5 HEIGHT RISES IN EXCESS OF 120M BY THE AFTERNOON. EVEN WITHOUT
THE CLOUD COVER...COOLER AIR THAT ARRIVED OVERNIGHT WILL HELP HOLD
TEMPERATURES TODAY BACK INTO THE TEENS AND 20S.
TONIGHT...WINDS WILL TURN OUT OF THE SW AND SHOULD BE QUITE STRONG
RIGHT THROUGH THE EVENING OUT AHEAD OF COLD THAT WILL BE MOVING
ACROSS NODAK. LLJ OUT AHEAD THE FRONT PROGGED BY THE GFS/NAM TO
BE AROUND 60 KTS...SO THIS WILL QUICKLY BRING WARMER AIR BACK INTO
THE REGION...WITH 925 MB TEMPS GETTING BACK UP AROUND THE 0C MARK
BY MONDAY AFTERNOON. THE ONLY THING HOLDING THE AREA BACK FROM
SEEING HIGHS IN THE MID AND EVEN UPPER 30S IS THE COLD FRONT
QUICKLY MOVE THROUGH IN THE MORNING...BUT STILL SHOULD SEE HIGHS A
FEW DEGS ON EITHER SIDE OF 30.
FOR TUESDAY...A FAIRLY SHARP AND NEGATIVELY TILTED H5 TROUGH IS
STILL FORECAST TO SWING THROUGH THE REGION. HAVE SEEN A SLIGHT SRN
SHIFT WITH THE ECMWF TOWARD THE GFS WITH QPF WITH THIS
WAVE...THOUGH IT STILL KEEPS QPF NORTH OF THE MPX CWA...WHERE IT
TAKES THE PV ANOMALY. THE FIM/GFS AND EVEN THE 06.00 GEM ARE NOW
BRINGING SOME PRECIP INTO THE NRN HALF OF THE MPX CWA. AT THIS
POINT...KEPT POPS BELOW 15% THOUGH DID ADD A MENTION OF SCT
FLURRIES ACROSS CENTRAL MN. MAIN REASON FOR NOT INCLUDING
MENTIONABLE POPS IS THAT THE PRIMARY SFC LOW...EVEN ON THE SRN
OUTLIER GFS IS PROGGED TO GO ACROSS SRN CANADA...WHICH WOULD HELP
KEEP BETTER PRECIP CHANCES UP ALONG THE INTERNATIONAL BORDER. EVEN
IF SNOW WERE TO OCCUR...IT WOULD BE ANOTHER HALF INCH OR LESS TYPE
SNOWFALL.
MODELS MAINTAIN DECENT AGREEMENT ON THE PROGRESSION OF THINGS NEXT
WEEK THROUGH WEDNESDAY...BUT QUICKLY DIVERGE AFTER THAT...WITH
EVEN RUN-TO-RUN CONSISTENCY WITHIN INDIVIDUAL MODELS BEING LESS
THAN IDEAL. AT ISSUE IS HOW THEY HANDEL THE CLOSED H5 LOW THAT IS
CURRENTLY NEAR SAN FRANCISCO. BY WEDNESDAY...THIS LOW WILL BE NEAR
THE BIG BEND REGION OF TX AS A DEEP AND POSITIVELY TILTED TROUGH
WORKS DOWN THE WEST COAST. AS ALL OF THIS IS GOING ON...AN
IMPRESSIVE RIDGE WILL BE BUILDING ACROSS THE ERN CONUS...WITH 590
DM HEIGHTS EXPECTED OVER FLA AND THE 576 DM LINE CLEAR UP TO THE
WI/IL BORDER. WHERE MODELS DIVERGE IS THE EXTENT WHICH THE CLOSED
LOW WILL INTERACT WITH THE WEST COAST TROUGH. OVER THE PAST 24 HRS
THE GFS AND ECMWF HAVE TRADED POSITIONS ON HOW TO HANDEL THE
WAVE...WITH THE GFS NOW BRINGING THE WAVE NORTH TOWARD THE GREAT
LAKES BY FRIDAY...WITH THE ECMWF TAKING THE WAVE ACROSS THE OHIO
VALLEY. THE GEM/FIM ARE MORE IN LINE WITH THE GFS...THOUGH A
LITTLE SLOWER. AT THIS POINT...GIVEN THE STRENGTH OF THE RIDGE
EXPECTED OVER THE SE...FIND IT HARD TO BELIEVE THE ECMWF SOLUTION
THAT IT WILL PLOW RIGHT THROUGH THE RIDGE AND WOULD FAVOR THE MORE
WRN SOLUTIONS. WHERE THERE IS AGREEMENT HOWEVER WITH THE
MODELS...IS THAT WHEREVER THE PRECIPITATION GOES...THICKNESSES
WILL BE WARM ENOUGH ACROSS THE MPX CWA FOR ALL RAIN ON THURSDAY.
IN FACT...MODELS DELAY THE ONSET OF THE COLD AIR BY A DAY
NOW...WITH THE ECMWF AND GEM SHOWING HIGHS IN THE 40S ON FRIDAY
ACROSS THE ERN HALF OF THE CWA...WHICH MEANS ANY TRANSITION BACK
TO SNOW POSSIBLY WAITING UNTIL AS LATE AS FRIDAY NIGHT OR
SATURDAY.
BESIDE THE POTENTIAL FOR RAIN...TEMPERATURE AND DEWPOINT FORECASTS
THURSDAY AND FRIDAY SHOW THE POTENTIAL FOR SOME AGGRESSIVE SNOW
MELT FOR JANUARY STANDARDS. BESIDE HIGHS POSSIBLY PUSHING 40 ONE
OR BOTH OF THE DAYS...THURSDAY NIGHT MAY SEE LOWS STAY ABOVE
FREEZING...WITH DEWPOINTS EVEN GETTING INTO THE MID/UPPER 30S.
EVEN WITHOUT ANY RAIN...THESE CONDITIONS WILL LIKELY LEAVE BARE
SPOTS IN THE SNOW COVER BY THIS WEEKEND.
AS FOR THE WEEKEND...MODEL AGREEMENT GETS NO BETTER. ABOUT ALL ONE
CAN SAY IS THAT THE WRN TROUGH WILL CONTINUE TO PUSH EAST...AND AS
IT DOES SO...MORE SEASONABLE AIR WILL MAKE A RETURN...WITH SOME
SNOW STILL LOOKING POSSIBLE.
&&
.AVIATION.../18Z TAF ISSUANCE/
THINGS GENERALLY LOOK QUIET AVIATION-WISE THROUGH THE FORECAST
PERIOD AS A RIDGE OF HIGH PRESSURE CURRENT SITUATED OVER THE
REGION MOVES EAST AND SOUTHWESTERLY FLOW DEVELOPS. A SURFACE LOW
WILL PASS BY WELL TO THE NORTH ON MONDAY... WITH A DIFFUSE FRONTAL
BOUNDARY MOVING ACROSS THE AREA DURING THE DAY. WITHOUT ANY
MOISTURE RETURN AHEAD OF THE SYSTEM NO PRECIPITATION OR LOW CLOUDS
ARE ANTICIPATED. THERE ARE SOME LOW CLOUDS CURRENTLY IMPACTING
WESTERN AND FAR EASTERN PORTIONS OF THE AREA. THESE FORMED IN THE
QUIESCENT CONDITIONS UNDER THE RIDGE AND SHOULD MIX AND/OR BE
ADVECTED OUT OF THE AREA THROUGH THE AFTERNOON HOURS. HOWEVER...
KAXN AND KEAU WILL HAVE SOME LOW CLOUD ISSUES THIS AFTERNOON...
PARTICULARLY KAXN WHERE LIFR CONDITIONS MAY LINGER THROUGH 00Z. A
DECENT PRESSURE GRADIENT DEVELOPS TONIGHT INTO MONDAY AHEAD OF THE
SYSTEM WHICH MOVES BY TO OUR NORTH... AND ALTHOUGH SURFACE WIND
GUSTS ARE NOT EXPECTED TO BE VERY SIGNIFICANT... THERE LOOKS TO BE
A PERIOD OVERNIGHT TONIGHT INTO EARLY MONDAY MORNING WHEN THE LOW
LEVEL JET WILL STRENGTHEN TO 45+ KT BETWEEN 1K AND 2K FT AGL.
INCLUDED A NON-CONVECTIVE WIND SHEAR MENTION IN THE TAFS FOR MOST
SITES... EXCEPT THE WEST WHERE SOME SURFACE GUSTINESS IS EXPECTED
TO OCCUR.
KMSP...TAF REFLECTS OVERALL EXPECTATIONS WITH MAIN UNCERTAINTY
BEING THE EXACT TIMING OF WIND SHIFTS AND THE DEGREE OF SURFACE
GUSTINESS VS ELEVATED WIND SHEAR AOA 1K FT AGL LATE TONIGHT. DO
NOT EXPECT A SIGNIFICANT VARIATION FROM THE TAF... BUT COULD SEE
DIFFERENCES OF +/- 2HRS AND/OR +/- 5KT.
/OUTLOOK FOR KMSP/
MONDAY NIGHT...VFR CONDITIONS EXPECTED. SOUTHWEST WINDS 5 TO 10 KT
BECOMING SOUTH.
TUESDAY...MVFR CEILINGS POSSIBLE LATE ALONG WITH A FEW FLURRIES.
SOUTH WINDS 10 TO 20 KT.
TUESDAY NIGHT...MVFR CEILINGS EXPECTED ALONG WITH A FEW FLURRIES.
SOUTHWEST WINDS 15 TO 25 KT BECOMING WEST.
WEDNESDAY...VFR CONDITIONS EXPECTED. WEST WINDS 10 TO 20 KT
BECOMING SOUTH LATE.
WEDNESDAY NIGHT...VFR CONDITIONS EXPECTED. SOUTH WINDS 10 TO 20
KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DULUTH MN
1200 PM CST SAT JAN 5 2013
.AVIATION.../18Z TAF ISSUANCE/
SKY COVER ACROSS THE NORTHLAND IS HIGHLY VARIABLE AT
MIDDAY...RANGING FROM IFR/LIFR IN THE KBRD AREA TO MVFR OR EVEN
SKC ACROSS THE REGION. THIS WILL CONTINUE TO BE THE CASE THIS
AFTERNOON BUT THINK THE TREND WILL BE TO OVERWHELMINGLY FAVOR MVFR
CIGS AS THE DAY WEARS ON. THE CLOUDS WILL THEN BREAK UP AGAIN
OVERNIGHT AND BECOME MOSTLY CLEAR AGAIN ON SUNDAY MORNING.
&&
.PREV DISCUSSION... /ISSUED 1025 AM CST SAT JAN 5 2013/
UPDATE...
REMOVED MENTION OF PATCHY FOG OVER SERN COUNTIES THIS MORNING AND
EXTENDED FOG MENTION UNTIL NOON ACROSS NRN COUNTIES. MATCHED
CURRENT SATELLITE/OBS TO GRIDS AND APPLIED LATEST HIGH RES/SHORT
RANGE MODELS TO TEMPS/WINDS AND SKIES. NEGLIGIBLE CHANGES MADE TO
FORECAST OVERALL.
PREV DISCUSSION... /ISSUED 535 AM CST SAT JAN 5 2013/
AVIATION...12Z TAFS.
VFR WITH PATCHY MVFR CIGS OVER THE MN ARROWHEAD AND ISOLD LIFR
CIGS/VSBYS IN FZFG AT THE OUTSET. EXPECT MORE CLOUDS TO FORM AS
SFC LOW MOVES INTO MN LATER TODAY. MVFR CIGS ARE ANTICIPATED WITH
SOME -SN OR FLURRIES DEVELOPING AROUND 18Z AS AN UPPER LEVEL TROF
ARRIVES. AFTER 01Z...LOOK FOR AN IMPROVEMENT TO VFR AS THE SFC LOW
DEPARTS AND HIGH PRESSURE MOVES IN.
PREV DISCUSSION... /ISSUED 301 AM CST SAT JAN 5 2013/
SHORT TERM...TODAY THROUGH SUNDAY.
A WEAK SURFACE LOW PRESSURE SYSTEM OVER NORTH DAKOTA WILL SLIDE
EASTWARD OVER NORTHERN MINNESOTA AND NORTHERN WISCONSIN TODAY. THIS
WILL BRING A SLIGHT CHANCE OF LIGHT SNOW THIS AFTERNOON AND EVENING
TO THE NORTHLAND. LITTLE IF ANY SNOW ACCUMULATIONS WILL OCCUR WITH
THIS SYSTEM. THE ONLY EXCEPTION WILL BE THE BAYFIELD PENINSULA AND
GOGEBIC RANGE WHERE LAKE EFFECT SNOWS WILL BEGIN ONCE THE LOW MOVES
TO THE EAST OVER THE EASTERN GREAT LAKES LATE SATURDAY NIGHT. THE
LAKE EFFECT SNOW SHOWERS WILL BEGIN TO TAPER OFF SUNDAY AS HIGH
PRESSURE BUILDS IN FROM THE CENTRAL PLAINS. SNOW ACCUMULATIONS FOR
THE BAYFIELD PENINSULA AND GOGEBIC RANGE WILL BE ONE TO TWO INCHES
WITH MOST OF THAT FALLING BETWEEN 06Z AND 12Z ON SUNDAY. HIGH
TEMPERATURES WILL AVERAGE SLIGHTLY ABOVE NORMAL OVER THE
WEEKEND...MAINLY IN THE LOWER TO MID 20`S.
LONG TERM...SUNDAY NIGHT THROUGH FRIDAY.
A STRONG AREA OF LOW PRESSURE WILL MOVE THROUGH SOUTH CENTRAL CANADA
JUST N OF THE INTERNATIONAL BORDER SUNDAY NIGHT THROUGH MONDAY
NIGHT. DUE TO THE TRACK OF THIS LOW...DO NOT EXPECT ANY SNOW OVER
THE NORTHERN TIER OF THE FA NEXT TO CANADA. WITH THE TIGHTENING
PRESSURE GRADIENT...THE WIND SPEED WILL INCREASE AND BE QUITE BRISK
ON MONDAY. THE WIND SHOULD DIMINISH MONDAY NIGHT HOWEVER AS THE
CANADIAN SFC LOW MOVES QUICKLY TO THE E. HIGH PRESSURE COVERS THE
AREA ON TUESDAY. BY TUESDAY NIGHT...THE MODELS DIVERGE WITH THE NEXT
AREA OF LOW PRESSURE. GFS TAKES THE LOW RIGHT THROUGH THE FA...ECMWF
IS WAY UP IN CANADA...THE GEM BARELY HAS A LOW CENTER SLOWLY MOVING
THROUGH MANITOBA. USED A BLENDED APPROACH WITH SMALL CHANCE POPS
TUESDAY NIGHT AND WEDNESDAY. THE MODELS GROW FARTHER APART WITH TIME
FOR THE REMAINDER OF THE LONG TERM AND USED A BLENDED APPROACH FOR
POPS/WEATHER.
AVIATION...06Z TAFS
MOST OF THE MVFR CEILINGS OVER FAR NORTHEAST MINNESOTA HAVE
DIMINISHED THIS EVENING...WITH MORE OVER FAR NORTH CENTRAL
WISCONSIN/UPPER MICHIGAN. SOME FOG AND IFR CEILINGS HAVE DEVELOPED
AS WELL...AND WE DID ADD VSBY REDUCTIONS AND IFR CEILINGS IN SOME
OF THE TAFS...PARTICULARLY KHIB. WE HAVE YET TO SEE MUCH LOWER
CLOUD DEVELOPMENT LATE THIS EVENING OUTSIDE OF THE SPOTTY IFR
CONDITIONS...AND THE RAP SEEMS TO BE HANDLING CLOUDS BETTER THAN
THE HRRR. AS LOW LEVEL WAA STRENGTHENS OVERNIGHT...WE STILL MAY
SEE SOME DEVELOPMENT LATE EXPANDING INTO SATURDAY. THE LOW IS
STILL FORECAST TO TRACK ACROSS CENTRAL-NORTHERN MINNESOTA
SATURDAY INTO UPPER MICHIGAN BY 00Z SUN. WE KEPT THE TAFS DRY
UNTIL 00Z...THEN IT APPEARS ENOUGH SATURATION WILL OCCUR TO GET
SOME LIGHT SNOW/FLURRIES. MORE SUBSTANTIAL SNOW SHOWERS WILL OCCUR
ALONG THE SOUTH SHORE DUE TO NORTHERLY WINDS FLOWING OVER THE
LAKE.
&&
.POINT TEMPS/POPS...
DLH 23 9 22 11 / 20 20 0 0
INL 17 -4 18 12 / 10 10 0 0
BRD 21 3 20 11 / 20 10 0 0
HYR 24 12 24 11 / 10 30 10 0
ASX 27 17 26 15 / 10 30 10 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...TENTINGER
LONG TERM....DAP
AVIATION...DAP
AREA FORECAST DISCUSSION
NWS DULUTH MN
1025 AM CST SAT JAN 5 2013
.UPDATE...
REMOVED MENTION OF PATCHY FOG OVER SERN COUNTIES THIS MORNING AND
EXTENDED FOG MENTION UNTIL NOON ACROSS NRN COUNTIES. MATCHED
CURRENT SATELLITE/OBS TO GRIDS AND APPLIED LATEST HIGH RES/SHORT
RANGE MODELS TO TEMPS/WINDS AND SKIES. NEGLIGIBLE CHANGES MADE TO
FORECAST OVERALL.
&&
.PREV DISCUSSION... /ISSUED 535 AM CST SAT JAN 5 2013/
AVIATION...12Z TAFS.
VFR WITH PATCHY MVFR CIGS OVER THE MN ARROWHEAD AND ISOLD LIFR
CIGS/VSBYS IN FZFG AT THE OUTSET. EXPECT MORE CLOUDS TO FORM AS
SFC LOW MOVES INTO MN LATER TODAY. MVFR CIGS ARE ANTICIPATED WITH
SOME -SN OR FLURRIES DEVELOPING AROUND 18Z AS AN UPPER LEVEL TROF
ARRIVES. AFTER 01Z...LOOK FOR AN IMPROVEMENT TO VFR AS THE SFC LOW
DEPARTS AND HIGH PRESSURE MOVES IN.
PREV DISCUSSION... /ISSUED 301 AM CST SAT JAN 5 2013/
SHORT TERM...TODAY THROUGH SUNDAY.
A WEAK SURFACE LOW PRESSURE SYSTEM OVER NORTH DAKOTA WILL SLIDE
EASTWARD OVER NORTHERN MINNESOTA AND NORTHERN WISCONSIN TODAY. THIS
WILL BRING A SLIGHT CHANCE OF LIGHT SNOW THIS AFTERNOON AND EVENING
TO THE NORTHLAND. LITTLE IF ANY SNOW ACCUMULATIONS WILL OCCUR WITH
THIS SYSTEM. THE ONLY EXCEPTION WILL BE THE BAYFIELD PENINSULA AND
GOGEBIC RANGE WHERE LAKE EFFECT SNOWS WILL BEGIN ONCE THE LOW MOVES
TO THE EAST OVER THE EASTERN GREAT LAKES LATE SATURDAY NIGHT. THE
LAKE EFFECT SNOW SHOWERS WILL BEGIN TO TAPER OFF SUNDAY AS HIGH
PRESSURE BUILDS IN FROM THE CENTRAL PLAINS. SNOW ACCUMULATIONS FOR
THE BAYFIELD PENINSULA AND GOGEBIC RANGE WILL BE ONE TO TWO INCHES
WITH MOST OF THAT FALLING BETWEEN 06Z AND 12Z ON SUNDAY. HIGH
TEMPERATURES WILL AVERAGE SLIGHTLY ABOVE NORMAL OVER THE
WEEKEND...MAINLY IN THE LOWER TO MID 20`S.
LONG TERM...SUNDAY NIGHT THROUGH FRIDAY.
A STRONG AREA OF LOW PRESSURE WILL MOVE THROUGH SOUTH CENTRAL CANADA
JUST N OF THE INTERNATIONAL BORDER SUNDAY NIGHT THROUGH MONDAY
NIGHT. DUE TO THE TRACK OF THIS LOW...DO NOT EXPECT ANY SNOW OVER
THE NORTHERN TIER OF THE FA NEXT TO CANADA. WITH THE TIGHTENING
PRESSURE GRADIENT...THE WIND SPEED WILL INCREASE AND BE QUITE BRISK
ON MONDAY. THE WIND SHOULD DIMINISH MONDAY NIGHT HOWEVER AS THE
CANADIAN SFC LOW MOVES QUICKLY TO THE E. HIGH PRESSURE COVERS THE
AREA ON TUESDAY. BY TUESDAY NIGHT...THE MODELS DIVERGE WITH THE NEXT
AREA OF LOW PRESSURE. GFS TAKES THE LOW RIGHT THROUGH THE FA...ECMWF
IS WAY UP IN CANADA...THE GEM BARELY HAS A LOW CENTER SLOWLY MOVING
THROUGH MANITOBA. USED A BLENDED APPROACH WITH SMALL CHANCE POPS
TUESDAY NIGHT AND WEDNESDAY. THE MODELS GROW FARTHER APART WITH TIME
FOR THE REMAINDER OF THE LONG TERM AND USED A BLENDED APPROACH FOR
POPS/WEATHER.
AVIATION...06Z TAFS
MOST OF THE MVFR CEILINGS OVER FAR NORTHEAST MINNESOTA HAVE
DIMINISHED THIS EVENING...WITH MORE OVER FAR NORTH CENTRAL
WISCONSIN/UPPER MICHIGAN. SOME FOG AND IFR CEILINGS HAVE DEVELOPED
AS WELL...AND WE DID ADD VSBY REDUCTIONS AND IFR CEILINGS IN SOME
OF THE TAFS...PARTICULARLY KHIB. WE HAVE YET TO SEE MUCH LOWER
CLOUD DEVELOPMENT LATE THIS EVENING OUTSIDE OF THE SPOTTY IFR
CONDITIONS...AND THE RAP SEEMS TO BE HANDLING CLOUDS BETTER THAN
THE HRRR. AS LOW LEVEL WAA STRENGTHENS OVERNIGHT...WE STILL MAY
SEE SOME DEVELOPMENT LATE EXPANDING INTO SATURDAY. THE LOW IS
STILL FORECAST TO TRACK ACROSS CENTRAL-NORTHERN MINNESOTA
SATURDAY INTO UPPER MICHIGAN BY 00Z SUN. WE KEPT THE TAFS DRY
UNTIL 00Z...THEN IT APPEARS ENOUGH SATURATION WILL OCCUR TO GET
SOME LIGHT SNOW/FLURRIES. MORE SUBSTANTIAL SNOW SHOWERS WILL OCCUR
ALONG THE SOUTH SHORE DUE TO NORTHERLY WINDS FLOWING OVER THE
LAKE.
&&
.POINT TEMPS/POPS...
DLH 23 9 22 11 / 20 20 0 0
INL 17 -4 18 12 / 10 10 0 0
BRD 21 3 20 11 / 20 10 0 0
HYR 24 12 24 11 / 10 30 10 0
ASX 27 17 26 15 / 10 30 10 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...TENTINGER
AREA FORECAST DISCUSSION
NWS DULUTH MN
535 AM CST SAT JAN 5 2013
.AVIATION...12Z TAFS.
VFR WITH PATCHY MVFR CIGS OVER THE MN ARROWHEAD AND ISOLD LIFR
CIGS/VSBYS IN FZFG AT THE OUTSET. EXPECT MORE CLOUDS TO FORM AS
SFC LOW MOVES INTO MN LATER TODAY. MVFR CIGS ARE ANTICIPATED WITH
SOME -SN OR FLURRIES DEVELOPING AROUND 18Z AS AN UPPER LEVEL TROF
ARRIVES. AFTER 01Z...LOOK FOR AN IMPROVEMENT TO VFR AS THE SFC LOW
DEPARTS AND HIGH PRESSURE MOVES IN.
&&
.PREV DISCUSSION... /ISSUED 301 AM CST SAT JAN 5 2013/
SHORT TERM...TODAY THROUGH SUNDAY.
A WEAK SURFACE LOW PRESSURE SYSTEM OVER NORTH DAKOTA WILL SLIDE
EASTWARD OVER NORTHERN MINNESOTA AND NORTHERN WISCONSIN TODAY. THIS
WILL BRING A SLIGHT CHANCE OF LIGHT SNOW THIS AFTERNOON AND EVENING
TO THE NORTHLAND. LITTLE IF ANY SNOW ACCUMULATIONS WILL OCCUR WITH
THIS SYSTEM. THE ONLY EXCEPTION WILL BE THE BAYFIELD PENINSULA AND
GOGEBIC RANGE WHERE LAKE EFFECT SNOWS WILL BEGIN ONCE THE LOW MOVES
TO THE EAST OVER THE EASTERN GREAT LAKES LATE SATURDAY NIGHT. THE
LAKE EFFECT SNOW SHOWERS WILL BEGIN TO TAPER OFF SUNDAY AS HIGH
PRESSURE BUILDS IN FROM THE CENTRAL PLAINS. SNOW ACCUMULATIONS FOR
THE BAYFIELD PENINSULA AND GOGEBIC RANGE WILL BE ONE TO TWO INCHES
WITH MOST OF THAT FALLING BETWEEN 06Z AND 12Z ON SUNDAY. HIGH
TEMPERATURES WILL AVERAGE SLIGHTLY ABOVE NORMAL OVER THE
WEEKEND...MAINLY IN THE LOWER TO MID 20`S.
LONG TERM...SUNDAY NIGHT THROUGH FRIDAY.
A STRONG AREA OF LOW PRESSURE WILL MOVE THROUGH SOUTH CENTRAL CANADA
JUST N OF THE INTERNATIONAL BORDER SUNDAY NIGHT THROUGH MONDAY
NIGHT. DUE TO THE TRACK OF THIS LOW...DO NOT EXPECT ANY SNOW OVER
THE NORTHERN TIER OF THE FA NEXT TO CANADA. WITH THE TIGHTENING
PRESSURE GRADIENT...THE WIND SPEED WILL INCREASE AND BE QUITE BRISK
ON MONDAY. THE WIND SHOULD DIMINISH MONDAY NIGHT HOWEVER AS THE
CANADIAN SFC LOW MOVES QUICKLY TO THE E. HIGH PRESSURE COVERS THE
AREA ON TUESDAY. BY TUESDAY NIGHT...THE MODELS DIVERGE WITH THE NEXT
AREA OF LOW PRESSURE. GFS TAKES THE LOW RIGHT THROUGH THE FA...ECMWF
IS WAY UP IN CANADA...THE GEM BARELY HAS A LOW CENTER SLOWLY MOVING
THROUGH MANITOBA. USED A BLENDED APPROACH WITH SMALL CHANCE POPS
TUESDAY NIGHT AND WEDNESDAY. THE MODELS GROW FARTHER APART WITH TIME
FOR THE REMAINDER OF THE LONG TERM AND USED A BLENDED APPROACH FOR
POPS/WEATHER.
AVIATION...06Z TAFS
MOST OF THE MVFR CEILINGS OVER FAR NORTHEAST MINNESOTA HAVE
DIMINISHED THIS EVENING...WITH MORE OVER FAR NORTH CENTRAL
WISCONSIN/UPPER MICHIGAN. SOME FOG AND IFR CEILINGS HAVE DEVELOPED
AS WELL...AND WE DID ADD VSBY REDUCTIONS AND IFR CEILINGS IN SOME
OF THE TAFS...PARTICULARLY KHIB. WE HAVE YET TO SEE MUCH LOWER
CLOUD DEVELOPMENT LATE THIS EVENING OUTSIDE OF THE SPOTTY IFR
CONDITIONS...AND THE RAP SEEMS TO BE HANDLING CLOUDS BETTER THAN
THE HRRR. AS LOW LEVEL WAA STRENGTHENS OVERNIGHT...WE STILL MAY
SEE SOME DEVELOPMENT LATE EXPANDING INTO SATURDAY. THE LOW IS
STILL FORECAST TO TRACK ACROSS CENTRAL-NORTHERN MINNESOTA
SATURDAY INTO UPPER MICHIGAN BY 00Z SUN. WE KEPT THE TAFS DRY
UNTIL 00Z...THEN IT APPEARS ENOUGH SATURATION WILL OCCUR TO GET
SOME LIGHT SNOW/FLURRIES. MORE SUBSTANTIAL SNOW SHOWERS WILL OCCUR
ALONG THE SOUTH SHORE DUE TO NORTHERLY WINDS FLOWING OVER THE
LAKE.
&&
.POINT TEMPS/POPS...
DLH 23 9 22 11 / 20 20 0 0
INL 20 -1 18 12 / 10 10 0 0
BRD 20 3 20 11 / 20 10 0 0
HYR 24 12 24 11 / 20 30 10 0
ASX 27 17 26 15 / 20 30 10 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
AVIATION...GSF
AREA FORECAST DISCUSSION
NWS DULUTH MN
301 AM CST SAT JAN 5 2013
.SHORT TERM...TODAY THROUGH SUNDAY.
A WEAK SURFACE LOW PRESSURE SYSTEM OVER NORTH DAKOTA WILL SLIDE
EASTWARD OVER NORTHERN MINNESOTA AND NORTHERN WISCONSIN TODAY. THIS
WILL BRING A SLIGHT CHANCE OF LIGHT SNOW THIS AFTERNOON AND EVENING
TO THE NORTHLAND. LITTLE IF ANY SNOW ACCUMULATIONS WILL OCCUR WITH
THIS SYSTEM. THE ONLY EXCEPTION WILL BE THE BAYFIELD PENINSULA AND
GOGEBIC RANGE WHERE LAKE EFFECT SNOWS WILL BEGIN ONCE THE LOW MOVES
TO THE EAST OVER THE EASTERN GREAT LAKES LATE SATURDAY NIGHT. THE
LAKE EFFECT SNOW SHOWERS WILL BEGIN TO TAPER OFF SUNDAY AS HIGH
PRESSURE BUILDS IN FROM THE CENTRAL PLAINS. SNOW ACCUMULATIONS FOR
THE BAYFIELD PENINSULA AND GOGEBIC RANGE WILL BE ONE TO TWO INCHES
WITH MOST OF THAT FALLING BETWEEN 06Z AND 12Z ON SUNDAY. HIGH
TEMPERATURES WILL AVERAGE SLIGHTLY ABOVE NORMAL OVER THE
WEEKEND...MAINLY IN THE LOWER TO MID 20`S.
.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY.
A STRONG AREA OF LOW PRESSURE WILL MOVE THROUGH SOUTH CENTRAL CANADA
JUST N OF THE INTERNATIONAL BORDER SUNDAY NIGHT THROUGH MONDAY
NIGHT. DUE TO THE TRACK OF THIS LOW...DO NOT EXPECT ANY SNOW OVER
THE NORTHERN TIER OF THE FA NEXT TO CANADA. WITH THE TIGHTENING
PRESSURE GRADIENT...THE WIND SPEED WILL INCREASE AND BE QUITE BRISK
ON MONDAY. THE WIND SHOULD DIMINISH MONDAY NIGHT HOWEVER AS THE
CANADIAN SFC LOW MOVES QUICKLY TO THE E. HIGH PRESSURE COVERS THE
AREA ON TUESDAY. BY TUESDAY NIGHT...THE MODELS DIVERGE WITH THE NEXT
AREA OF LOW PRESSURE. GFS TAKES THE LOW RIGHT THROUGH THE FA...ECMWF
IS WAY UP IN CANADA...THE GEM BARELY HAS A LOW CENTER SLOWLY MOVING
THROUGH MANITOBA. USED A BLENDED APPROACH WITH SMALL CHANCE POPS
TUESDAY NIGHT AND WEDNESDAY. THE MODELS GROW FARTHER APART WITH TIME
FOR THE REMAINDER OF THE LONG TERM AND USED A BLENDED APPROACH FOR
POPS/WEATHER.
&&
.AVIATION...06Z TAFS
MOST OF THE MVFR CEILINGS OVER FAR NORTHEAST MINNESOTA HAVE
DIMINISHED THIS EVENING...WITH MORE OVER FAR NORTH CENTRAL
WISCONSIN/UPPER MICHIGAN. SOME FOG AND IFR CEILINGS HAVE DEVELOPED
AS WELL...AND WE DID ADD VSBY REDUCTIONS AND IFR CEILINGS IN SOME
OF THE TAFS...PARTICULARLY KHIB. WE HAVE YET TO SEE MUCH LOWER
CLOUD DEVELOPMENT LATE THIS EVENING OUTSIDE OF THE SPOTTY IFR
CONDITIONS...AND THE RAP SEEMS TO BE HANDLING CLOUDS BETTER THAN
THE HRRR. AS LOW LEVEL WAA STRENGTHENS OVERNIGHT...WE STILL MAY
SEE SOME DEVELOPMENT LATE EXPANDING INTO SATURDAY. THE LOW IS
STILL FORECAST TO TRACK ACROSS CENTRAL-NORTHERN MINNESOTA
SATURDAY INTO UPPER MICHIGAN BY 00Z SUN. WE KEPT THE TAFS DRY
UNTIL 00Z...THEN IT APPEARS ENOUGH SATURATION WILL OCCUR TO GET
SOME LIGHT SNOW/FLURRIES. MORE SUBSTANTIAL SNOW SHOWERS WILL OCCUR
ALONG THE SOUTH SHORE DUE TO NORTHERLY WINDS FLOWING OVER THE
LAKE.
&&
.POINT TEMPS/POPS...
DLH 23 9 22 11 / 20 20 0 0
INL 20 -1 18 12 / 10 10 0 0
BRD 20 3 20 11 / 20 10 0 0
HYR 24 12 24 11 / 20 30 10 0
ASX 27 17 26 15 / 20 30 10 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...KK
LONG TERM....GSF
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS DULUTH MN
1123 PM CST FRI JAN 4 2013
.AVIATION...06Z TAFS
MOST OF THE MVFR CEILINGS OVER FAR NORTHEAST MINNESOTA HAVE
DIMINISHED THIS EVENING...WITH MORE OVER FAR NORTH CENTRAL
WISCONSIN/UPPER MICHIGAN. SOME FOG AND IFR CEILINGS HAVE DEVELOPED
AS WELL...AND WE DID ADD VSBY REDUCTIONS AND IFR CEILINGS IN SOME
OF THE TAFS...PARTICULARLY KHIB. WE HAVE YET TO SEE MUCH LOWER
CLOUD DEVELOPMENT LATE THIS EVENING OUTSIDE OF THE SPOTTY IFR
CONDITIONS...AND THE RAP SEEMS TO BE HANDLING CLOUDS BETTER THAN
THE HRRR. AS LOW LEVEL WAA STRENGTHENS OVERNIGHT...WE STILL MAY
SEE SOME DEVELOPMENT LATE EXPANDING INTO SATURDAY. THE LOW IS
STILL FORECAST TO TRACK ACROSS CENTRAL-NORTHERN MINNESOTA
SATURDAY INTO UPPER MICHIGAN BY 00Z SUN. WE KEPT THE TAFS DRY
UNTIL 00Z...THEN IT APPEARS ENOUGH SATURATION WILL OCCUR TO GET
SOME LIGHT SNOW/FLURRIES. MORE SUBSTANTIAL SNOW SHOWERS WILL OCCUR
ALONG THE SOUTH SHORE DUE TO NORTHERLY WINDS FLOWING OVER THE
LAKE.
&&
.PREV DISCUSSION... /ISSUED 823 PM CST FRI JAN 4 2013/
UPDATE...
TEMPS HAVING BEEN DROPPING QUICKLY IN SPOTS...AND ADJUSTED MINS
TONIGHT DOWN A FEW DEGREES IN SPOTS. SOME PATCHY FOG ALSO
OCCURRING AND WE ADDED SOME TO THE GRIDS. WE DON`T EXPECT THE FOG
TO BE TOO WIDESPREAD OR DENSE.
PREV DISCUSSION... /ISSUED 551 PM CST FRI JAN 4 2013/
AVIATION...00Z TAFS
MAIN CONCERN REVOLVES AROUND THE MVFR CEILINGS OVER FAR NORTHEAST
MINNESOTA...AND THE POSSIBLE DEVELOPMENT OR REDEVELOPMENT FURTHER
SOUTH LATER TONIGHT INTO SATURDAY.
THE RAP SUGGESTS THE MVFR CEILINGS OVER FAR NORTHEAST MINNESOTA
WILL REMAIN THERE OR MOVE OFF TO THE EAST. INCREASING WAA
OVERNIGHT RESULTS IN THE MODELS INCREASING LOW LEVEL RH OVER OUR
SOUTHERN CWA SHORTLY AFTER 06Z...THEN FURTHER NORTH LATE TONIGHT
INTO SATURDAY. NO EVIDENCE OF THIS YET...BUT WAA WILL BE RAMPING
UP. WE DID ADD A TEMPO GROUP TO SEVERAL TAFS TONIGHT...AND DID GO
WITH PREVAILING MVFR CEILINGS IN MOST TAFS AT SOME POINT SATURDAY.
LOW PRESSURE WILL MOVE INTO THE RED RIVER VALLEY BY 12Z...THEN
CONTINUE EAST TOWARD LAKE SUPERIOR BY MID DAY...THEN INTO UPPER
MICHIGAN BY SATURDAY EVENING. SOME LIGHT SNOW OR FLURRIES WILL
ALSO BE POSSIBLE...BUT MOST MODELS SUGGEST THEY MAY NOT OCCUR
UNTIL LATE IN THE PERIOD OR SATURDAY EVENING SO WE DID NOT ADD TO
THE TAFS YET.
SOME LIGHT FOG MAY ALSO BE CONCERN LATER TONIGHT INTO SATURDAY MORNING...AND
WE DID ADD SOME 3-6SM VSBY RESTRICTIONS.
PREV DISCUSSION... /ISSUED 348 PM CST FRI JAN 4 2013/
SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT...
COOLER AIR WILL GRADUALLY FILTER INTO MUCH OF THE NORTHLAND
OVERNIGHT AS DIFFUSE FRONTAL ZONE CONTINUES TO SAG SOUTHWARD WITH
WINDS GRADUALLY TURNING TO THE N/NE. LOCALLY GUSTY WINDS ALONG THE
NORTH SHORE WILL SUBSIDE THIS EVENING AS PRESSURE RISE CENTER
MOVES OFF TO THE EAST OF THE REGION.
NEXT UPSTREAM WAVE IS CLEARLY EVIDENT IN WV IMAGERY COMING EAST OF
THE CANADIAN ROCKIES..AND ASSOCIATED WEAK SFC LOW TAKING SHAPE
OVER SRN SASKATCHEWAN. THIS WAVE WILL STEADILY MOVE ESEWD TOWARD
THE NORTHLAND TONIGHT AND SATURDAY WITH A SLOW BUT STEADY INCREASE
IN CLOUD COVER LATE TONIGHT AND THE FIRST PART OF THE DAY
SATURDAY. OVERALL..LIFT WITH THIS WAVE WILL BE RELATIVELY BENIGN
AND ACHIEVING DEEP LAYER SATURATION FOR MORE THAN A FEW HOURS LATE
SAT/SAT NIGHT WILL LIKELY BE AN ISSUE IN MOST AREAS. THUS..OVERALL
SNOW CHANCES DONT APPEAR TO BE ALL THAT ROBUST. HOWEVER..MOST
SHORT RANGE GUIDANCE MASS FIELDS ARE IN AGREEMENT THAT LOW LEVEL
WARM ADVECTION WILL BE FAIRLY STRONG..AND AIDED BY MODEST AND
SHALLOW FRONTOGENESIS FOR AT LEAST SEVERAL HOURS OVER ERN MN/NW WI
AND LK SUPERIOR. WE WILL NEED TO WATCH THIS AS THERE COULD BE A
BAND OF LIGHT SNOW THAT SETS UP SOMEWHERE FROM NEAR DULUTH EAST
TOWARD THE U.P. OF MICHIGAN..AND IF THIS OCCURS THERE COULD BE AN
INCH OR TWO OF SNOW OVER A SMALL AREA OF THE ERN CWA BY SUNDAY
MORNING.
THIS WAVE WILL TRAVERSE THE AREA RATHER QUICKLY..FOLLOWED BY COLD
ADVECTION AND AT LEAST A SHORT PERIOD OF LK EFFECT SNOW POTENTIAL
ON THE SOUTH SHORE BEGINNING SAT EVENING INTO SUNDAY. RIGHT NOW IT
APPEARS THAT ACCUMS WILL BE RELATIVELY LIGHT ALONG THE SOUTH
SHORE..BUT WE DID INCREASE POPS INTO THE 60-80 PERCENT RANGE FOR
THE BAYFIELD PENINSULA AND GOGEBIC RANGE FOR SAT NIGHT.
LONG TERM...SUNDAY THROUGH THURSDAY...
THE PERIOD WILL BEGIN WITH THE NORTHLAND IN THE WAKE OF A SURFACE
LOW PRESSURE SYSTEM...WHICH SHOULD BE IN MAINLAND MICHIGAN...AND
SURFACE HIGH PRESSURE IN THE NORTHERN PLAINS BEGINNING TO MOVE
INTO THE FA. THE NORTHERLY WINDS OVER WESTERN LAKE SUPERIOR COULD
RESULT IN LINGERING LAKE EFFECT SNOW FOR THE SOUTH SHORE SUNDAY
MORNING...BUT IT SHOULD CEASE BY THE AFTERNOON DUE TO THE CHANGING
WIND DIRECTION. AFTER THE HIGH PRESSURE MOVES IN...THE NORTHLAND
IS GOING TO HAVE A TOUGH TIME GETTING PCPN FOR A FEW DAYS. IT
LOOKS LIKE A LOW PRESSURE SYSTEM WILL MOVE THROUGH
CENTRAL/NORTHERN MANITOBA AND ONTARIO EARLY NEXT WEEK...BUT IT
WILL PROBABLY BE TOO FAR AWAY TO BRING ANY MEASURABLE PCPN TO THE
FA. THE MODELS HAVE BEEN INDICATING A POTENT MID/UPPER LEVEL LOW
CUTTING ACROSS THE SOUTHWESTERN US THIS WEEKEND AND LIFTING INTO
THE UPPER MIDWEST MID TO LATE NEXT WEEK. MOST OF THE MODELS KEEP
THE ASSOCIATED SURFACE LOW WELL ENOUGH EAST OF THE FA TO PREVENT
THE NORTHLAND FROM BEING AFFECTED BY THE SYSTEM...WITH THE
EXCEPTION OF THE ECMWF. THE ECMWF LIFTS THE SURFACE LOW INTO
CENTRAL/EASTERN WISCONSIN...AND BRINGS CONSIDERABLE PCPN TO THE SE
FA. CONSIDERING THE ECMWF HAS TEMPERATURES NEAR OR SLIGHTLY BELOW
FREEZING IN NW WISCONSIN...FORECASTED A CHANCE OF A MIXTURE OF
RAIN AND SNOW. WILL NEED TO KEEP A CLOSE EYE ON THE MODELS TO SEE
HOW THIS SYSTEM WILL AFFECT THE NORTHLAND. TEMPERATURES THROUGH
THE PERIOD SHOULD BE NEAR OR ABOVE NORMAL.
&&
.POINT TEMPS/POPS...
DLH 13 23 9 22 / 0 20 20 0
INL -5 20 -1 18 / 10 10 10 0
BRD 7 20 3 20 / 0 20 10 0
HYR 8 24 12 24 / 0 20 30 10
ASX 10 26 17 26 / 0 20 30 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...MELDE/MILLER
AVIATION.....MELDE
AREA FORECAST DISCUSSION
NWS JACKSON MS
1000 AM CST SAT JAN 5 2013
.UPDATE...
LATEST SATELLITE IMAGERY SHOWED AN UPPER DISTURBANCE MOVING NORTHEAST OVER
NORTHWEST MISSOURI LATE THIS MORNING. IT WAS BRINGING IN ISENTROPIC
LIFT ON TOP OF A 1030 MB SURFACE RIDGE IN THE FORM OF VERY LIGHT
RAIN. MORNING SOUNDINGS SHOWS SOME LOW LEVEL DRY AIR WHICH WAS
MOISTENING UP FROM TOP DOWN. LATEST LOCAL WRF AND AND RUC SHOWS LIGHT
RAIN ACROSS THE REGION WITH THE BEST COVERAGE ACROSS THE SOUTHEAST
2/3RDS BEFORE ENDING FROM THE NORTHWEST THIS EVENING. CURRENT HIGHS
IN THE UPPER 40S TO MIDDLE 50S LOOKS TO BE ON TRACK. HAVE LOWERED
POPS SOME TO MOSTLY LIKELY CATEGORY FOR TODAY BEFORE LOWERING TO
CHANCE CATEGORY BY MID AFTERNOON./17/
./PREVIOUS DISCUSSION...400 AM CST SAT JAN 5 2013
.SHORT TERM...(TODAY THROUGH SUNDAY NIGHT)...
DECENT MID LEVEL DISTURBANCE IN THE OK PANHANDLE MOVING ENE AT 30KTS
THIS MORNING AND DRAGGING MOISTURE OVER THE TOP OF OUR SURFACE RIDGE
AXIS(1030MB) CENTERED ALONG THE MS RIVER NEAR KGLH. ISENTROPIC
UPGLIDE ON THE 300-310K SURFACES WILL BE ENOUGH FOR WIDESPREAD
SPRINKLES STARTING BY DAYLIGHT WRN HALF AND SPREADING OVER THE ENTIRE
CWFA BEFORE MIDDAY. CANNOT TOTALLY RULE OUT A FEW REPORTS OF SLEET AT
THE ONSET OF THE RAIN BUT THE NARROW LOW LEVEL DRY LAYER WAS ERODING
AT A RAPID PACE.
OVERALL...BEST MOISTURE TRANSPORT AND OMEGA APPEARS TO CROSS SRN 1/3
OF THE AREA SO WILL HAVE BEST CATEGORICAL POPS FOR MEASURING ONE
QUARTER INCH RAINFALL AMOUNTS. OTHERWISE...MOST LOCATIONS REMAIN
UNDER A TENTH OF AN INCH AS CLOUDY SKIES AND VERY MINIMAL WINDS SEE
TEMPS HOLDING MAINLY M-U40S.
THE LIGHT RAINS END RATHER QUICKLY FROM W TO E THIS EVENING BUT
CLOUDS MAY LINGER UNTIL A WEAK LOW LEVEL TROUGH PASSES EARLY SUNDAY
MORNING. EARLY SUNDAY LOWS SHOULD HOLD IN THE M-U30S. SKIES SHOULD
CLEAR SUNDAY MORNING WITH INCREASING DOWNGLIDE AND DRYING AIRMASS
COMING IN FROM THE CENTRAL ROCKIES. EVEN WITH EXPECTED SUNSHINE
SUNDAY AFTERNOON...HIGHS STAY IN THE NEAR NORMAL 50S. THAT LEADS
INTO A CLEAR AND CHILLY SUNDAY NIGHT WITH ANOTHER SURFACE HIGH OF
1032MB POSITIONED IN SRN MO MOVING E. A GOOD RADIATIONAL COOLING
SETUP FOR US EARLY MONDAY SHOULD BRING MORE FROST AND LOW TEMPS
AGAIN IN THE U20-L30S. /40/
.LONG TERM...(MONDAY THROUGH SATURDAY)...
NEAR NORMAL CONDITIONS WILL OPEN THE WORK WEEK AS HIGHS MON CLIMB
INTO THE MID 50S. A FEW MID AND HIGH LEVEL CLOUDS WILL BE STREAMING
BY AS A WEAK/MOISTURE STARVED S/WV LIFTS ACROSS THE REGION IN
SOUTHWESTERLY FLOW ALOFT. STRONG HIGH PRESSURE WILL TAKE ANCHOR
ALONG THE EASTERN SEABOARD ON TUE ALLOWING A WARMING TREND TO
COMMENCE HEADED INTO THE MIDDLE PORTION OF THE WEEK...ALONG WITH
INCREASING CLOUD COVER AS TIME PASSES.
THE MAIN FOCUS FOR THIS FORECAST PACKAGE IS ON THE EVOLUTION OF A
CLOSED LOW THE MODELS SHOW CROSSING THE DESERT SOUTHWEST EARLY IN
THE WEEK...GRADUALLY MAKING ITS WAY OVER THE SOUTHERN PLAINS AND
INTO THE MID/UPPER MS VALLEY REGION LATE IN THE WEEK. THE MODELS
SEEM TO BE COMING INTO BETTER AGREEMENT WITH REGARD TO TIMING OF
THIS SYSTEM...WITH THE OUTLIER BEING THE FASTER OP GFS WHICH LACKS
SUPPORT FROM EVEN THE GFS ENSEMBLE MEAN. AS SUCH...TONIGHT`S
EXTENDED FORECAST LEANS HEAVILY ON THE 00Z ECMWF/GFS ENS MEAN/ECMWF
MEAN. THIS SOLUTION HOLDS OFF ON ANY WARM FRONTAL RAINS ACROSS THE
ARKLAMISS UNTIL LATE TUE NIGHT OR EARLY WED MORNING JUST BEFORE THE
WARM FRONT LIFTS ACROSS THE REGION. THE 00Z ECMWF IS QUITE
AGGRESSIVE WITH THE LOW LEVEL MOISTURE TRANSPORT SHOWING 65 DEGREE
SFC DEW POINTS AS FAR NORTH AS GLH/GWO BY WED EVENING JUST BEFORE
THE COLD FRONT PASSES. THIS MAY BE A BIT AGGRESSIVE...BUT ISN`T
TOTALLY OUT OF THE QUESTION GIVEN THE RICH POOL OF MOISTURE SHOWN
OFFSHORE OF BROWNSVILLE TX ON LATEST TPW SATELLITE PRODUCTS. THE
POTENTIAL FOR SFC BASED INSTABILITY AND ASSOCIATED RISK OF SEVERE
WEATHER (MAINLY IN THE FORM OF WIND GUSTS GIVEN "WARM" TEMPS ALOFT)
GOES UP IF WE CAN GET THAT KIND OF MOISTURE PULLED THIS FAR NORTH.
GIVEN THE FACT THAT SLOWER TIMING OF THIS SYSTEM OVERALL IS FAVORED
(ALLOWING MORE TIME FOR THE MOISTURE TO ARRIVE)...AND THE STRENGTH
OF THE AMBIENT WIND FIELDS...AM GOING TO ADD THE POTENTIAL FOR
STRONG WIND GUSTS TO THE HWO FOR THE SOUTHERN HALF OF THE CWA.
TIMING IS STILL A BIT OF A CHALLENGE...BUT LOOKS LIKE THE MAIN
TIMEFRAME FOR THE WORST OF THE WEATHER WILL BE LATE WED INTO
THU...AT LEAST FOR NOW. STAY TUNED FOR UPDATES ON THAT. THE ECMWF
ALSO SHOWS SOME POTENTIAL FOR TORNADOES ACROSS SOUTHERN AREAS GIVEN
STRONG LOW LEVEL SHEAR AHEAD OF THE CONVECTION...AND IF THE LOW
LEVEL MOISTURE CAN GET IN HERE...THIS ISN`T TOTALLY OUT OF THE
QUESTION. WILL BE KEEPING AN EYE ON THAT.
IN ADDITION TO THE RISK OF STRONG WIND GUSTS WILL BE THE POTENTIAL
FOR A QUICK ONE TO TWO INCHES OF RAINFALL WITH THIS SYSTEM. GIVEN
THE MOIST GROUND CONDITIONS IN PLACE WILL CONTINUE TO MENTION THE
HEAVY RAIN POTENTIAL IN THE HWO/GRAPHICS AS THIS COULD RE-AGGRAVATE
SOME MINOR RIVER FLOOD ISSUES.
THE RAINS LOOK TO CLEAR OUT BY LATE THU AS THE COLD FRONT PASSES...
BUT IT APPEARS THE FRONT WILL QUICKLY LIFT NORTH HEADED INTO FRI AS
STRONG HIGH PRESSURE REMAINS OVER THE EASTERN/SOUTHEASTERN CONUS.
THIS WILL ALLOW WARMER TEMPS TO RETURN OVER THE WEEKEND...
ACCOMPANIED BY LOW END RAIN CHANCES.
AS FOR TEMPS...GFS MOS HIGHS/LOWS WERE TWEAKED (QUITE A BIT AROUND
MID WEEK) TOWARD THE GENERALLY WARMER ECMWF MOS. POPS WERE ADJUSTED
TO FOLLOW ALONG WITH TIMING OFFERED BY THE ECMWF AS WELL. /BK/
&&
.AVIATION...VFR CEILINGS WILL PREVAIL THROUGH EARLY SUNDAY LOWERING
BRIEFLY TO 3-4K FEET AT TIMES. AREAS OF RAIN WILL CAN BE EXPECTED
TODAY...BRINGING BRIEF LOCALLY MVFR VISIBILITIES. /40/03
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 48 33 57 30 / 60 18 7 4
MERIDIAN 53 34 57 27 / 56 24 8 4
VICKSBURG 48 34 56 29 / 58 15 6 4
HATTIESBURG 56 38 60 34 / 54 24 12 6
NATCHEZ 48 35 56 32 / 60 18 7 5
GREENVILLE 48 34 53 28 / 53 11 6 3
GREENWOOD 48 32 55 26 / 54 13 7 4
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
17/03/40/BK
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1236 PM EST SUN JAN 6 2013
.SYNOPSIS...
A WEAK AREA OF LOW PRESSURE WILL BRING MINOR SNOW ACCUMULATIONS TO
MOST LOCATIONS THIS AFTERNOON AND EVENING...BUT SNOWS WILL BE
A BIT STEADIER EAST OF LAKE ONTARIO. HIGH PRESSURE WILL THEN BUILD
INTO THE OHIO VALLEY AND EASTERN GREAT LAKES FOR THE FIRST HALF OF
NEXT WEEK WITH DRY WEATHER AND WARMING TEMPERATURES. THE JANUARY
THAW WILL LAST RIGHT THROUGH NEXT WEEKEND WITH MILD TEMPERATURES AND
INCREASING CHANCES OF RAIN.
&&
.NEAR TERM /THROUGH TONIGHT/...
A WIDESPREAD AREA OF MAINLY LIGHT WET SNOW CONTINUES ACROSS MOST OF
WESTERN NY EARLY THIS AFTERNOON...AND HAS RECENTLY BLOSSOMED EAST OF
LAKE ONTARIO. THIS ALL APPEARS TO BE ASSOCIATED WITH WEAK ASCENT
FROM A MID LEVEL SHORTWAVE EVIDENT IN WATER VAPOR IMAGERY. THE SNOW
WILL BECOME STEADIEST EAST OF LAKE ONTARIO AS THE SHORTWAVE
INTERACTS WITH AN OLD FRONTAL ZONE IN THE AREA...AND SOME VERY
LIMITED LAKE ENHANCEMENT BEGINS.
AT LOWER ELEVATIONS TEMPERATURES ARE ABOVE FREEZING...SO JUST EXPECT
LESS THAN AN INCH OF ACCUMULATION ON EXISTING SNOW...WITH ROADS JUST
REMAINING WET. SOME RAIN WILL ALSO MIX IN AT LOWER ELEVATIONS
ESPECIALLY ALONG THE LAKESHORES. THE HIGHER TERRAIN OF THE SOUTHERN
TIER MAY PICK UP AN INCH OR SO TODAY AS TEMPERATURES REMAIN CLOSER
TO THE FREEZING MARK. EAST OF LAKE ONTARIO THE LOWER ELEVATIONS MAY
PICK UP AN INCH OR SO THIS AFTERNOON...WITH AROUND 2 INCHES ACROSS
THE TUG HILL AND WESTERN FOOTHILLS OF THE ADIRONDACKS.
THE NEXT PART OF THIS GENERALLY WEAK SYSTEM WILL IMPACT THE REGION
DURING THE LATE AFTERNOON AND EVENING HOURS. THE KEY WILL BE THE
PASSAGE OF ANOTHER SHORT WAVE...WHICH WILL HELP DRIVE A COLD FRONT
ACROSS THE REGION. HOWEVER...THERE WILL BE WELL ALIGNED SOUTHWEST
FLOW AHEAD OF THIS...WITH AMPLE MOISTURE AND A LONG FETCH. 850 MB
TEMPERATURES WILL ONLY BE AROUND -7C...WITH LAKE INDUCED CAPES
BARELY MEASURABLE. HOWEVER...THIS WILL PROBABLY BE ENOUGH TO BOOST
MOISTURE A BIT...AND BRING A PERIOD OF SNOW TO MOST LOCATIONS. THE
QPF FORECAST OF MOST OF THE HIGHER RESOLUTION MODEL GUIDANCE
SUGGESTS THIS ENHANCEMENT WILL BE A SIGNIFICANT PART OF WHATEVER
SNOW FALLS...AND SEVERAL RUNS OF THE HRRR ARE PRODUCING PLAUSIBLE
SOLUTIONS.
THE LIONS SHARE OF SNOW WILL FALL BETWEEN 21Z AND 06Z...WITH MOST
LOCATIONS LIKELY TO SEE ONLY A FEW HOURS OF LIGHT TO MODERATE
SNOWS SOMEWHERE IN THAT TIMEFRAME. EXPECT AN INCH OR TWO TO FALL EAST
OF LAKE ERIE...MAINLY ACROSS THE HIGHER TERRAIN WITH AN ADDED BOOST
FROM UPSLOPE FLOW. STEADIER SNOWS WILL FALL EAST OF LAKE
ONTARIO...WITH STEADIER SNOWS LIKELY TO DEVELOP THIS AFTERNOON...AND
CONTINUE INTO THE EVENING. HRRR GUIDANCE SUGGESTS A BAND OF MODERATE
SNOW WILL DEVELOP...WITH A TOTAL OF 2 TO 4 INCHES OF SNOW LIKELY IN
THAT REGION THIS AFTERNOON AND EVENING. THIS IS IN LINE WITH THE
SEVERAL RUNS OF THE RGEM/NAM. ONE LIMITING FACTOR MAY BE
TEMPERATURES...WHICH WILL BE NEAR OR ABOVE FREEZING THROUGH THE
EVENT AT LOWER ELEVATIONS...WHICH MAY TEMPER ACCUMULATIONS NEAR LAKE
ONTARIO. THE LEAST AMOUNT OF SNOW WILL FALL FROM THE SOUTH SHORE OF
LAKE ONTARIO INTO THE FINGER LAKES...WHERE THE LEAST PRECIP AND
WARMEST BOUNDARY LAYER TEMPERATURES WILL BE FOUND. SOME OF THESE
AREAS MAY SEE NO ACCUMULATION AT ALL.
THE FRONT WILL PUSH SOUTH OF THE REGION LATE TONIGHT...WHICH SHOULD
BRING DRIER AIR INTO THE REGION. SOME LIGHT LAKE EFFECT SNOW SHOWERS
OR FLURRIES CAN/T BE RULED OUT...BUT WHAT DOES DEVELOP SHOULD BE
SHORT LIVED GIVEN THE SHORT FETCH IN THE NORTHERLY FLOW AND THE DRY
AIR UPSTREAM. HOWEVER...THIS SET UP IS FAVORABLE FOR CLOUDS TO BE
QUITE PERSISTENT BEHIND THE FRONT...AS ANY LAKE MOISTURE GETS
TRAPPED BENEATH THE INVERSION. BECAUSE OF THIS...HEDGE ON THE WARM
SIDE OF GUIDANCE FOR LOW TEMPERATURES. EXPECT LOWS IN THE LOWER 20S
IN MOST LOCATIONS...BUT SIGNIFICANTLY COOLER TEMPERATURES ARE
POSSIBLE EAST OF LAKE ONTARIO WHERE CLEARING IS POSSIBLE.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
A QUIET PERIOD IS EXPECTED MONDAY AND TUESDAY WITH A SLOW MODERATING
TREND TO CONTINUE THROUGH THE WORK WEEK.
FOR MONDAY A FEW FLURRIES OR LIGHT SNOW SHOWERS MAY STILL BE FALLING
OFF LAKE ONTARIO SOUTHEAST OF THE LAKE EARLY IN THE MORNING HOURS.
TEMPERATURES ALOFT AT 850 HPA UNDER WARM AIR ADVECTION ARE ONLY
MARGINAL FOR LAKE EFFECT SNOW...AND WITH LOW LEVEL LIFT ESSENTIALLY
GONE AND MOISTURE LACKING FROM WITHIN THE SNOW GROWTH ZONE...ANY
SUPPORT FOR LAKE EFFECT SNOW WILL NOT BE CONDUCIVE...THUS ANY LAKE
ACTIVITY SHOULD DIMINISH QUICKLY THROUGH THE MORNING. THE 850 HPA
RIDGE REMAINS TO OUR WEST TO START THE DAY AND A BROKEN LOW LAYER OF
CLOUDS ACROSS HIGHER TERRAIN OF WNY...GENESEE VALLEY AND NORTHERN
FINGER LAKES REGION WILL LIKELY START THE DAY. AS THIS RIDGE AXIS
PASSES THE AREA FROM WEST TO EAST THROUGH THE MORNING HOURS EXPECT
INCREASING AMOUNTS OF SUNSHINE. DESPITE A GOOD DEAL OF SUNSHINE
THROUGH THE AFTERNOON HOURS TEMPERATURES WILL HOLD TO AROUND NORMAL
ACROSS WESTERN NEW YORK...WITH HIGHS AROUND 30...AND SLIGHTLY BELOW
NORMAL ACROSS THE EASTERN LAKE ONTARIO REGION WITH LOW TO MID
20S.
MONDAY NIGHT A BROAD AREA OF HIGH PRESSURE WILL BE FOUND ALONG THE
ATLANTIC COASTLINE WITH A SOUTHWEST RETURN FLOW ACROSS THE EASTERN
GREAT LAKES REGION. THIS WILL PROHIBIT TEMPERATURES FROM
PLUNGING...AND IN FACT THEY MAY RISE A DEGREE OR TWO OVERNIGHT
ACROSS THE DOWN SLOPE AREAS OF WNY. TOWARDS THE NORTHERN FINGER
LAKES AND EASTERN LAKE ONTARIO REGION WHERE THE SOUTHWEST FLOW WILL
NOT BE AS GREAT TEMPERATURES WILL FALL BACK INTO THE TEENS TO AROUND
20. TO THE WEST MILDER OVERNIGHT LOWS ARE EXPECTED...WITH LOW 20S
ACROSS INTERIOR SOUTHWEST NEW YORK AND UPPER 20S FOR THE LOWER
ELEVATIONS.
LATE MONDAY NIGHT AND TUESDAY A STORM SYSTEM WILL PASS WELL TO OUR
NORTH ACROSS JAMES BAY AND CENTRAL/NORTHERN QUEBEC. A TIGHTENING
PRESSURE GRADIENT BETWEEN THIS SYSTEM AND HIGH PRESSURE ALONG THE
EASTERN SHORELINE WILL ALLOW WINDS TO BECOME BREEZY THROUGH THE DAY
TUESDAY...ESPECIALLY OFF THE LAKES ON A SOUTHWEST FLOW. A FEW CLOUDS
WILL LIKELY PASS ACROSS THE REGION THOUGH STILL A GOOD DEAL OF
SUNSHINE IS EXPECTED. TEMPERATURES ALOFT AT 850 HPA WILL BE SEVERAL
DEGREES WARMER THAN MONDAY...AND WITH THESE SOUTHWEST WINDS
TEMPERATURES SHOULD BE A BIT WARMER THAN MONDAY...WITH HIGHS
MODERATING INTO THE MID TO UPPER 30S. REMAINING DRY OVERNIGHT THOUGH
CLOUDS WILL START TO THICKEN MORE AS A SECOND STORM SYSTEM TAKES A
SLIGHTLY MORE SOUTHERN TRACK THROUGH CANADA. LOWS TUESDAY NIGHT WILL
FALL BACK INTO THE MID 20S TO AROUND 30 ACROSS THE REGION.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
A GENERAL ZONAL FLOW WILL REMAIN IN PLACE ALONG THE CANADIAN/U.S.
BORDER THROUGH THURSDAY. AFTER THAT...A MORE AMPLIFIED FLOW WILL SET
UP THURSDAY NIGHT THROUGH SATURDAY AS A DEEPENING TROUGH DIGS INTO
THE WESTERN U.S...WHILE A FLAT RIDGE REMAINS IN PLACE OVER EASTERN
THIRD OF THE NATION.
REGARDING THE FORECAST DETAILS...A WELL DEFINED SHORT WAVE WILL
PASS JUST NORTH OF NEW YORK STATE ON WEDNESDAY...BEFORE DRIFTING
INTO NORTHERN NEW ENGLAND WEDNESDAY NIGHT. A TIGHT PRESSURE GRADIENT
BETWEEN THIS LOW AND HIGH PRESSURE OVER THE SOUTHEAST WILL AGAIN
MAKE FOR A BREEZY TO WINDY DAY ACROSS THE REGION. EXPECT WIND GUSTS
TO BE STRONGER WEDNESDAY THAN TUESDAY...WITH THE LOW CLOSER TO THE
REGION. A FEW GUSTS MAY APPROACH 40 TO 45 MPH IN TRADITIONALLY GUSTY
AREAS OF THE CWA.
A WEAK FRONT THAT IS ASSOCIATED WITH THIS IMPULSE WILL DROP SOUTH
ACROSS NEW YORK STATE WEDNESDAY NIGHT...BUT THE FRONT WILL NOT HAVE
MUCH MOISTURE TO WORK WITH. WILL HAVE LOW CHC POPS EAST OF LAKE
ONTARIO WHERE SOME LAKE ENHANCEMENT TO THE PRECIPITATION MIGHT
OCCUR. OTHERWISE EXPECT THE REGION TO REMAIN DRY.
ON THURSDAY...THE GFS AND ECMWF ARE IN BETTER AGREEMENT REGARDING
THE MOVEMENT OF THE CLOSED LOW THAT WILL BE LIFTING OUT OF THE
SOUTHERN PLAINS. THE GFS IS STILL A LITTLE FASTER IN LIFTING THE
UPPER LOW OUT...BUT THE GENERAL TREND IS THAT ANY PCPN ASSOCIATED
WITH THE APPROACHING LOW MAY DELAYED UNTIL THURSDAY NIGHT. THE
SLOWER MOVEMENT OF THE LOW ALSO MEANS THAT IT WILL TAKE LONGER THE
FOR BOUNDARY LAYER TEMPERATURES TO MODERATE. THIS MAY RESULT IN A
BETTER CHANCE FOR LIGHT SNOW AT THE ONSET OF THE PCPN.
ON FRIDAY...THE UPPER LOW WILL WEAKEN AS IT ENCOUNTERS THE FLAT
RIDGE THAT WILL STILL BE IN PLACE OVER THE EASTERN PART OF THE
NATION. BY SATURDAY...THE ECMWF TAKES THE ASSOCIATED SURFACE LOW AND
MERGES IT WITH A DEEPER LOW THAT WILL BE LIFTING NORTH ACROSS JAMES
BAY. SINCE THE SURFACE LOW IS FORECAST TO STAY TO OUR WEST...A MILD
SOUTHWEST FLOW WILL PREVAIL ACROSS THE AREA. THIS WILL LIKELY CAUSE
MOST PCPN TO FALL AS RAIN ON FRIDAY AND SATURDAY.
THE MODERATING TREND DURING THIS PERIOD WILL PUSH TEMPERATURES INTO
THE LOWER TO MID 40S ACROSS MOST OF THE AREA ON FRIDAY AND SATURDAY.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
WIDESPREAD LIGHT SNOW WILL CONTINUE THIS AFTERNOON AND EVENING
ACROSS WESTERN NY AND THE NORTH COUNTRY...AND WILL BE MIXED WITH
SOME RAIN NEAR THE LAKESHORES THROUGH THE REST OF THE DAYLIGHT
HOURS. EXPECT MAINLY MVFR CONDITIONS THROUGH MID AFTERNOON WITH SOME
SPOTTY IFR CIGS ACROSS HIGHER TERRAIN. LATE THIS AFTERNOON AND EARLY
THIS EVENING A MID LEVEL TROUGH WILL CROSS THE AREA AND MAY ENHANCE
SNOW SOMEWHAT...WITH VSBY DROPPING TO IFR IN SOME SPOTS FOR SEVERAL
HOURS. THIS WILL BE MOST PREVALENT ACROSS THE HIGHER TERRAIN OF THE
WESTERN SOUTHERN TIER INCLUDING KJHW...AND ALSO EAST OF LAKE ONTARIO
INCLUDING KART WITH SOME MINOR LAKE ENHANCEMENT.
THE SNOW WILL GRADUALLY TAPER OFF FROM WEST TO EAST LATER THIS
EVENING WITH IFR ACROSS THE WESTERN SOUTHERN TIER AND EAST OF LAKE
ONTARIO IMPROVING TO MVFR. EXPECT PLENTY OF STRATUS TO KEEP MVFR
CIGS GOING FOR THE REST OF THE NIGHT BEFORE LOW LEVEL WINDS SHIFT TO
THE SOUTHWEST MONDAY MORNING AND BEGIN TO SCOUR OUT LOW LEVEL
MOISTURE...WITH A RETURN TO VFR EXPECTED.
OUTLOOK...
TUESDAY THROUGH THURSDAY...MAINLY VFR.
FRIDAY...VFR/MVFR WITH A CHANCE OF RAIN SHOWERS.
&&
.MARINE...
LOW PRESSURE ACROSS THE CENTRAL LAKES WILL LIFT UP THE SAINT
LAWRENCE VALLEY LATER TODAY. THIS WILL RESULT IN A DECENT SOUTHWEST
FLOW AND SMALL CRAFT CONDITIONS TODAY AND INTO TONIGHT. WINDS WILL
SHIFT TO THE NORTH AS AN ASSOCIATED COLD FRONT DROPS ACROSS THE
WATERS TONIGHT. THEN HIGH PRESSURE WILL BUILD ACROSS THE WATERS
MONDAY...WITH DIMINISHING WINDS. AS THE HIGH SLIDES EAST...A
TIGHTENING PRESSURE GRADIENT MAY REQUIRE SMALL CRAFT ADVISORIES
AGAIN MID-WEEK IN A SOUTHWESTERLY FLOW.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EST MONDAY FOR LEZ040-041.
SMALL CRAFT ADVISORY UNTIL 9 PM EST THIS EVENING FOR
LEZ020.
SMALL CRAFT ADVISORY UNTIL 10 AM EST MONDAY FOR
LOZ043-044.
SMALL CRAFT ADVISORY UNTIL 4 AM EST MONDAY FOR LOZ042-045.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL/HITCHCOCK
SHORT TERM...THOMAS
LONG TERM...THOMAS/TJP
AVIATION...HITCHCOCK
MARINE...APFFEL/THOMAS
AREA FORECAST DISCUSSION
NWS BUFFALO NY
401 AM EST SAT JAN 5 2013
.SYNOPSIS...
HIGH PRESSURE WILL BRING FAIR WEATHER FOR MOST TODAY...BEFORE AN
AREA OF LOW PRESSURE MOVES THROUGH THE GREAT LAKES TONIGHT AND
SUNDAY WITH A WIDESPREAD LIGHT SNOWFALL. ANOTHER HIGH WILL BUILD IN
BEHIND THE LOW MONDAY...WITH A CHILLY START TO THE WEEK. AS THIS
HIGH MOVES INTO THE ATLANTIC...TEMPERATURES WILL WARM THROUGH
MID-WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
TODAYS WEATHER WILL BE MUCH LESS EVENTFUL...AS HIGH PRESSURE PASSES
NORTH OF THE REGION. A WEAK FRONTAL BOUNDARY WILL DROP SOUTHWARD TO LAKE
ONTARIO...BUT THEN STALL AND EVENTUALLY LIFT BACK NORTH LATER TODAY.
THROUGH 400 AM...THERE ARE LIGHT LAKE EFFECT SNOW SHOWERS
LINGERING EAST OF LAKE ONTARIO...BUT NO ACTIVITY OFF LAKE ERIE.
THERE ARE ALSO A FEW SNOW SHOWERS WITH THE FRONT ITSELF.
OTHERWISE...SKIES WHERE CLOUDY ACROSS MOST OF THE REGION...WITH
JUST A FEW BREAKS. THIS IS A BIT MORE PESSIMISTIC THAN PREVIOUS
GUIDANCE. THIS COMBINED WITH THE WINDS HAS KEPT TEMPERATURES FROM
DROPPING...ESPECIALLY EAST OF LAKE ONTARIO WHICH IS JUST ON THE
WARM SIDE OF THE FRONT. COLDER TEMPERATURES SHOULD MAKE IT INTO
THE NORTH COUNTRY EARLY THIS MORNING...WITH ELSEWHERE LIKELY TO
REMAIN IN THE MID AND UPPER 20S DUE TO THE CLOUD COVER.
WHAT IS LEFT OF THE LAKE EFFECT SNOW SHOWERS WILL SLIDE SOUTH AND
DISSIPATE THROUGH MID-MORNING. THE FRONT MAY PROVIDE A BRIEF
ENHANCEMENT...BUT ALL OF THIS SHOULD BE ON THE LITE SIDE...WITH
LITTLE IF ANY SNOW ACCUMULATION THROUGH THIS MORNING. THE HRRR MODEL
HAS A GOOD MODEL ON THESE TRENDS...AND IS GENERALLY SUPPORTED BY THE
RGEM/NAM IN QPF FORECASTS.
OTHERWISE...EXPECT FAIR WEATHER TODAY...WITH SOME BREAKS OF SUN...ESPECIALLY
EAST OF LAKE ONTARIO WHICH WILL BE NORTH OF THE FRONTAL BOUNDARY.
CLOUDS SHOULD LINGER LONGEST IN THE SOUTHERN TIER...AND ALONG THE
FRONTAL BOUNDARY. TEMPERATURES SHOULD BE SEASONABLE...WITH HIGHS
IN THE LOWER 30S IN MOST LOCATIONS...MID TO UPPER 20S IN THE
EASTERN LAKE ONTARIO REGION.
FOR TONIGHT...A WEAK ARE OF LOW PRESSURE WILL MOVE ACROSS THE UPPER
LAKES. THIS WILL SWING A WEAK AREA OF WARM AIR ADVECTION IN THE
MID-LEVELS...AS AN UPPER TROF AXIS QUICKLY CROSSES THE REGION.
BUFKIT SHOWS LIFT BOTH IN THE MID AND UPPER LEVELS...SUGGESTING EACH
FEATURE WILL MAKE A CONTRIBUTION. LAKES MAY PROVIDE A MINIMAL
MOISTURE CONTRIBUTION...BUT THIS WILL LARGELY BE A SYNOPTIC EVENT.
DESPITE MODEST QPF VALUES...AVERAGING A TENTH OF AN INCH OR
LESS...THERE IS BROAD MODEL AGREEMENT THAT THERE WILL BE SOME
MEASURABLE PRECIPITATION ACROSS MOST OF THE CWA. BECAUSE OF
THIS...GENERALLY GO WITH CATEGORICAL POPS...DESPITE THE MODEST
AMOUNTS OF QPF.
ITS INTERESTING TO NOTE THAT DESPITE THE MARGINALLY COLD
TEMPERATURES AT THE SURFACE...OMEGA LINES UP FAIRLY WELL WITH SNOW
GROWTH REGIONS WHICH SUGGESTS FAIRLY DECENT SNOW RATIOS. THIS
SAID...THE QUICK PROGRESSION OF THE SHORTWAVE...AND MODEST WARM AIR
ADVECTION SUPPORT LIGHT QPFS WHICH ARE THE MODEL CONSENSUS. GIVEN
SUCH LIGHT QPF...SNOW RATIO WILL NOT HAVE MUCH OF AN IMPACT ON
AMOUNTS. FOR MOST AREAS EXPECT AROUND AN INCH OF SNOW TONIGHT...WITH
LESSER AMOUNTS INLAND ACROSS ALLEGANY/LIVINGSTON/ONTARIO COUNTIES.
SNOW SHOULD MOVE INTO THE REGION LATE THIS EVENING...AND BRING A
RATHER QUICK 3 TO 6 HOUR PERIOD OF LIGHT SNOW.
OVERNIGHT LOWS SHOULD COME DURING THE EVENING HOURS...WITH
TEMPERATURES RISING LATER IN THE NIGHT AS WARMER AIR AND CLOUDS
ADVECT INTO THE REGION.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
TWO SHORTWAVES WILL IMPACT THE REGION SUNDAY...PRODUCING LIGHT
SNOWFALL ACROSS THE REGION. THE FIRST SHORTWAVE CROSSING THE EASTERN
GREAT LAKES FROM THE SOUTHWEST WILL BE IN THE PROCESS OF CROSSING
THE REGION SUNDAY MORNING WITH SNOWFALL FOCUSED EAST OF THE GENESEE
VALLEY.
THE SECOND SHORTWAVE...THIS IN THE NORTHERN BRANCH OF THE JET STREAM
WILL SLIGHTLY DEEPEN A SURFACE LOW ACROSS THE SOUTHERN ONTARIO
CANADA REGION SUNDAY. A SOUTHWEST FLOW AHEAD OF THE LOW AND ITS
ASSOCIATED COLD FRONT...WITH 925 HPA TEMPERATURES AROUND -3 TO -4C
WILL CREATE JUST ENOUGH LAKE INSTABILITY THAT A LITTLE LAKE ENHANCED
SNOW SHOWERS ARE LIKELY AHEAD OF THE COLD FRONT. LOW LEVEL LIFT IS
MARGINAL...BUT IT SHOULD SUFFICE TO BRING MOISTURE UP INTO THE
BOTTOM OF THE GOOD SNOW GROWTH ZONE LATER IN THE DAY SUNDAY.
OFF BOTH LAKE ERIE AND ONTARIO WINDS WILL BACK ENOUGH AHEAD OF THE
COLD FRONT TO ALLOW THE LAKE ENHANCED SNOW SHOWERS TO BEGIN AROUND
BUFFALO AND THE NORTHTOWNS OFF LAKE ERIE...AND WATERTOWN AND TOWNS
NORTH OFF LAKE ONTARIO. WHILE SYNOPTIC SNOW IS LIKELY ACROSS MUCH OF
THE REGION SUNDAY NIGHT AHEAD OF THE COLD FRONT...WILL FOCUS THE
HIGHEST POPS WITHIN A BAND OF LAKE ENHANCED SNOW SHOWERS THAT WILL
QUICKLY DROP SOUTHWARD OFF BOTH LAKES THROUGH THE AFTERNOON AND
EARLY EVENING HOURS.
THE COMBINATION OF LAKE SNOWS AND SYNOPTIC SNOWS WILL QUICKLY END
THROUGH THE OVERNIGHT HOURS AS DRIER AIR USHERS IN BEHIND THE COLD
FRONT THAT CROSSES MUCH OF THE CWA SUNDAY NIGHT. LAKE ENHANCED SNOW
WILL END FIRST OFF LAKE ERIE...AND LATER IN THE NIGHT OFF LAKE
ONTARIO WITH JUST A FLURRY LINGERING TOWARDS DAWN SOUTH AND EAST OF
LAKE ONTARIO.
AS FAR AS SNOWFALL GOES SUNDAY AND SUNDAY NIGHT AREAS EAST OF LAKE
ONTARIO WILL LIKELY RECEIVED THE GREATEST SNOW TOTALS OF 2 TO 4
INCHES...WITH EARLY MORNING SYNOPTIC SNOW...AND THEN LATER IN THE
AFTERNOON SOME LAKE ENHANCED SNOW SHOWERS IN ADDITION TO A LIGHT
SYNOPTIC SNOWFALL AHEAD OF THE COLD FRONT. SOUTH OF LAKE ONTARIO
SNOWFALL SUNDAY AND SUNDAY EVENING WILL LIKELY AVERAGE A HALF TO ONE
INCH WITH THE HIGHER TERRAIN SOUTH OF BUFFALO POSSIBLY NEARING 2
INCHES.
TEMPERATURES ON SUNDAY WILL CLIMB TO THE LOW TO MID 30S ACROSS THE
REGION BEFORE FALLING BACK TO SEASONAL NORMALS SUNDAY NIGHT BEHIND
THE COLD FRONT. A NORTHWEST FLOW WILL LIKELY MAINTAIN CLOUDS ACROSS
MUCH OF THE AREA SOUTH OF LAKE ONTARIO WITH ONLY PARTIAL CLEARING
LATE ACROSS THE NORTHERN NIAGARA FRONTIER AND NORTHERN GENESEE
VALLEY. TOWARDS THE NORTH COUNTRY SOME CLEARING IS LIKELY TO THE
NORTH AND WEST OF THE TUG HILL AND WESTERN FOOT HILLS OF THE
ADIRONDACKS...AND HERE WE COULD SEE TEMPERATURES DROP LATE IN THE
NIGHT TOWARDS THE LOW SINGLE DIGITS.
MONDAY MORNING THE TAIL END OF THE COLD FRONT WILL STALL ACROSS
CENTRAL NEW YORK WITH SOME PATCHES OF CLOUDS LINGERING THROUGH THE
MORNING ACROSS THE INTERIOR SOUTHERN TIER AND SOUTHERN FINGER LAKES.
THIS TRAILING COLD FRONT WILL SEPARATE TWO AREAS OF HIGH
PRESSURE...ONE OVER QUEBEC...AND A SECOND OVER THE OHIO VALLEY.
THESE TWO AIRMASSES...COMBINED WITH THE PASSING OF AN UPPER LEVEL
RIDGE AXIS SHOULD GIVE A QUIET DAY TO THE REGION MONDAY WITH MOST
AREAS MOSTLY SUNNY BY AFTERNOON. STILL ON THE CHILLY SIDE MONDAY
EVEN WITH PLENTY OF SUNSHINE AS HIGH TEMPERATURES WILL LIKELY HOLD
IN THE 20S ACROSS MUCH OF THE REGION. THOUGH WARM AIR ADVECTION
ALOFT AND LIGHT SOUTHERLY WINDS AT THE SURFACE LOWS MONDAY
NIGHT...TEMPERATURES SHOULD DROP TO A SIMILAR VALUES AS THE
PRECEDING NIGHT AS SKIES WILL LIKELY BE MAINLY CLEAR THROUGH THE
NIGHT ALLOWING FOR ADDITIONAL AMOUNTS OF RADIATIONAL COOLING.
OVERNIGHT LOWS WILL DROP BACK INTO THE TEENS...WHILE THE NORTH
COUNTRY WILL LIKELY AGAIN DROP INTO THE SINGLE DIGITS.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
A GENERAL ZONAL FLOW IS FORECAST TO BE IN PLACE ALONG THE
CANADIAN/US BORDER TUESDAY AND WEDNESDAY...WHILE A CLOSED LOW LIFTS
OUT OF THE SOUTHWEST PART OF THE COUNTRY. THE GFS AND ECMWF STILL
HAVE SIGNIFICANT DISCREPANCIES IN THE WAY THEY HANDLE THIS CUTOFF
LOW. THE ECWMF KEEPS THE LOW OVER THE SOUTHERN PLAINS THROUGH
WEDNESDAY...BEFORE LIFTING IT OUT INTO THE MIDWEST ON
THURSDAY...WHILE THE GFS LIFTS THE LOW OUT ON WEDNESDAY AND TRACKS
AN OPEN WAVE TOWARD THE LOWER LAKE ON THURSDAY. FOR NOW...WILL
CONTINUE TO HPC GUIDANCE WHICH SEEMS TO FAVOR THE MORE CONSERVATIVE
ECMWF SOLUTION. BASED ON THIS GUIDANCE...WILL KEEP THE AREA DRY
THROUGH WEDNESDAY NIGHT AS THE SURFACE LOW THAT WILL BE ASSOCIATED
WITH THE CLOSED STAYS WELL TO OUR WEST.
THE ECMWF LIFTS THE CLOSED LOW INTO THE MIDWEST ON THURSDAY...THEN
OPEN THE WAVE UP ON FRIDAY AS IT TRACKS IT EAST ACROSS THE LOWER
LAKES. THE CORRESPONDING SURFACE LOW IS FORECAST TO HEAD NORTHEAST
TOWARD THE CENTRAL GREAT LAKES ON THURSDAY...BEFORE TRACKING NORTH
OF LAKE ONTARIO ON FRIDAY. THE DEEP LAYERED SOUTHERLY FLOW AHEAD OF
THIS SYSTEM WILL TRANSPORT MILDER AIR NORTH TOWARD OUR AREA. WHILE
TEMPERATURES ALOFT LOOK WARM ENOUGH TO SUPPORT MAINLY RAIN...SURFACE
TEMPERATURES WILL BE THE KEY TO THE PCPN TYPE. BASED ON FORECAST
TEMPERATURES...WE MAY SEE A MIX OF FROZEN PCPN THURSDAY MORNING
BEFORE TEMPERATURES WARM UP ENOUGH FOR A POSSIBLE CHANGEOVER TO ALL
RAIN DURING THE AFTERNOON. MIXED PCPN COULD SET UP AGAIN ACROSS THE
HIGHER ELEVATIONS THURSDAY NIGHT BEFORE ALL PCPN CHANGES BACK OVER
TO RAIN ON FRIDAY. FOR NOW WILL KEEP FORECAST AS RAIN AND SNOW...AND
FINE TUNE THE MIXED PRECIPITATION OF SLEET AND FREEZING RAIN AS WE
DRAW CLOSER TO THE EVENT. STAY TUNED TO LATER MODEL RUNS WHICH WILL
HELP TO FINE TUNE THIS POTENTIAL FOR MIXED PCPN.
REGARDING TEMPERATURES...EXPECT A MODERATING TREND THAT WILL SEE
DAYTIME HIGHS RISING INTO THE UPPER 30S/LOWER 40S ON WEDNESDAY AND
THURSDAY...AND MAYBE EVEN THE LOW/MID 40S ON FRIDAY.
&&
.AVIATION /09Z SATURDAY THROUGH WEDNESDAY/...
WINDS HAVE DIMINISHED ACROSS THE REGION...WHICH END THE BLOWING AND
DRIFTING SNOW. AT 09Z...MOST TAF LOCATIONS WERE VFR...AS A DRIER AIR
AND A LIFTING INVERSION HAS ALLOWED CIGS TO LIFT. THERE MAY BE
PERIODS OF MVFR CIGS AT BUF/IAG/ROC...OTHERWISE MAINLY VFR CONDITIONS
ARE LIKELY FOR TODAY. A LOWER CLOUD DECK WILL LINGER AT JHW...LIKELY
INTO THE MORNING HOURS BEFORE LIFTING AND SCATTERING.
FOR TONIGHT...EXPECT A PERIOD OF GENERALLY LIGHT SNOWFALL TO BRIEFLY
RESULT IN IFR CONDITIONS DUE TO VSBY IN THE 1 TO 2 SM RANGE.
ACCUMULATIONS WILL BE LIGHT.
OUTLOOK...
SUNDAY...MVFR/IFR WITH CHANCE OF SNOW SHOWERS.
MONDAY AND TUESDAY...VFR.
WEDNESDAY...VFR/MVFR WITH A CHANCE OF RAIN.
&&
.MARINE...
WINDS HAVE DROPPED IN THE LAST SEVERAL HOURS...WITH A CONTINUED
DIMINISHING TREND EXPECTED THROUGH TODAY. SMALL CRAFT ADVISORIES ARE
IN PLACE ACROSS MOST OF THE WATERS...BUT THESE SHOULD BE ABLE TO BE
DROPPED LATER THIS MORNING.
AFTER THIS...EXPECT A RELATIVELY QUIET PERIOD ON THE WATERS...WITH
NO MAJOR SYSTEMS FORECAST THROUGH THE MIDDLE OF NEXT WEEK. THIS
SAID...THERE WILL BE SEVERAL OPPORTUNITIES FOR SMALL CRAFT
ADVISORIES...DEPENDING ON WIND DIRECTION AND STRENGTH.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EST THIS MORNING FOR LEZ040-
041.
SMALL CRAFT ADVISORY UNTIL 10 AM EST THIS MORNING FOR
LOZ042-043.
SMALL CRAFT ADVISORY UNTIL NOON EST TODAY FOR LOZ044-045.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL
SHORT TERM...THOMAS
LONG TERM...THOMAS/TJP
AVIATION...APFFEL
MARINE...APFFEL/THOMAS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
610 PM EST SUN JAN 6 2013
.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE WILL MOVE OFF THE CAROLINA COAST THIS
EVENING. A COLD FRONT WILL MOVE ACROSS CENTRAL NORTH CAROLINA
TONIGHT. HIGH PRESSURE WILL BUILD INTO REGION ON MONDAY AND PERSIST
THROUGH TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 220 PM SUNDAY...
AREAS OF PATCHY LIGHT RAIN ACROSS THE FAR SOUTHERN PIEDMONT...
SOUTHERN SANDHILLS AND SOUTHERN COASTAL PLAIN WILL PERSIST ON AND
OFF THROUGH AROUND 03Z. THE LAST BATCH OF RAIN TO MOVE THROUGH THIS
AREA IS CURRENTLY DEVELOPING IN SC WITH INDIVIDUAL ELEMENTS MOVING
QUICKLY NORTHEAST WHILE THE WHOLE AREA SHIFTS EAST. THE FEED OF LOW
LEVEL MOISTURE IS ABATING AS NOTED IN RECENT VWP IMAGERY FROM
COASTAL RADARS AND THE AIRMASS IS BEGINNING TO DRY OUT AT MID LEVELS
ACROSS THE FOOTHILLS AND THE PIEDMONT. HIGH RESOLUTION GUIDANCE
INCLUDING RECENT RUNS OF THE HRRR STILL INDICATE THAT LIGHT RAIN
WILL CONTINUE TO SKIRT THE SOUTHEASTERN THIRD OF THE RAH CWA THROUGH
THE EARLY EVENING HOURS. LATER TONIGHT A COLD FRONT WILL SWEEP
ACROSS CENTRAL NC AHEAD OF A MID TROUGH WHICH WILL RESULT IN
DRAMATIC DRYING AND SUBSIDENCE LATE TONIGHT. EXPECT CLEAR SKIES BY
DAYBREAK WITH THE EXCEPTION OF A FEW MID LEVEL CLOUDS IN THE COASTAL
PLAIN. A COLDER AIR MASS IS ADVECTED INTO THE AREA VERY LATE
ALLOWING LOW TEMPS TO FALL INTO THE 29-35 RANGE. -BLAES
&&
.SHORT TERM /MONDAY AND TUESDAY NIGHT/...
AS OF 3 PM SUNDAY...
SHORT RANGE RIDGING BUILDS INTO THE SOUTHEAST ON MONDAY AND THEN
QUICKLY TRANSLATES OFF THE COAST MONDAY NIGHT. AT THE SURFACE...A
1033MB HIGH PRESSURE SYSTEM ACROSS THE LOWER OH VALLEY MONDAY
MORNING WILL SHIFT EAST AND THEN RIDGE INTO CENTRAL NC FROM THE
COAST LATE MONDAY NIGHT. THE AIR MASS ACROSS CENTRAL NC DURING THE
SHORT RANGE PERIOD WILL BE CHARACTERIZED BY PW VALUES AROUND 0.20
INCHES AND SLIGHTLY BELOW NORMAL TEMPERATURES. SUNNY SKIES ARE
EXPECTED ON MONDAY WITH CLEAR SKIES PERSISTING INTO THE EVENING
HOURS. SOME CIRRUS CLOUDS WILL WORK INTO THE AREA FROM THE WEST LATE
MONDAY NIGHT AS THE UPPER LEVEL RIDGE AXIS SHIFT EAST. IN
ADDITION...A RETURN FLOW NEAR THE SURFACE MAY RESULT IN THE
DEVELOPMENT OF SOME LOW STRATUS THAT WILL MOVE INTO CENTRAL NC FROM
THE SOUTH AND EAST TOWARD DAYBREAK TUESDAY. HIGH TEMPERATURES ON
MONDAY WILL RANGE IN THE 47-54 RANGE WITH OVERNIGHT LOWS BETWEEN 26
AND 31 DEGREES. -BLAES
TUESDAY AND TUESDAY NIGHT:
SURFACE HIGH PRESSURE WILL MOVE FURTHER OFFSHORE ON TUESDAY AND
TUESDAY NIGHT... WHILE CONTINUING TO EXTEND BACK WESTWARD INTO
CENTRAL NC. THIS WILL ALLOW LOW LEVEL MOISTURE RETURN IN A SOUTH TO
NORTH FASHION... BELOW A STRONG SUBSIDENCE INVERSION AT AROUND 850
MB. THIS WILL LEAD TO PARTLY SUNNY TO MOSTLY CLOUDY SKIES ACROSS
SOUTHERN PORTIONS OF THE AREA BY TUESDAY AFTERNOON... WITH LOCATIONS
ACROSS THE NORTH REMAINING MOSTLY TO PARTLY SUNNY. HOWEVER... THE
INCREASE IN LOW LEVEL SOUTHERLY FLOW WILL ALLOW FOR HIGH TEMPS TO BE
SEVERAL DEGREES WARMER THAN HIGHS FROM MONDAY AFTERNOON... DESPITE
THE INCREASING CLOUD COVER. THUS... EXPECT WE WILL SEE HIGH TEMPS
RANGE FROM THE LOWER 50S NW TO UPPER 50S SE.
MOISTURE WILL CONTINUE TO INCREASE ON TUESDAY NIGHT INTO WEDNESDAY
MORNING... WITH PERHAPS A FEW LIGHT SHOWERS ACROSS SOUTHEASTERN
PORTIONS OF THE AREA ASSOCIATED WITH AN INVERTED SURFACE TROUGH NEAR
THE COAST AND POSSIBLE WEAK SURFACE LOW NEAR THE COAST. THUS... WITH
THE INCREASE IN MOISTURE EXPECT LOW TEMPS WEDNESDAY MORNING SHOULD
BE SEVERAL CATEGORIES WARMER THAN THE PREVIOUS MORNING.THIS YIELDS
HIGH RANGING FROM THE MID 30S NORTH (WHERE LOW STRATUS AND FOG
SHOULD BE THE LEAST TO AROUND 40 ACROSS THE SOUTH. -BSD
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 310 PM SUNDAY...
WEDNESDAY THROUGH SUNDAY:
MEDIUM RANGE MODELS ARE COMING INTO BETTER AGREEMENT ON THE OVERALL
UPPER FLOW PATTERN ACROSS THE CONUS DURING THIS PERIOD. HOWEVER...
TIMING AND FINER DETAIL DIFFERENCES STILL EXIST.
EXPECT THE SUBTROPICAL RIDGE TO EXTEND/BUILD ACROSS CENTRAL NC FOR
WEDNESDAY AND THURSDAY... WHILE A NORTHERN STREAM TROUGH TRACKS
ACROSS THE GREAT LAKES AND NORTHEAST. THE NORTHERN STREAM TROUGH
WILL SEND A MOSTLY DRY COLD FRONT ACROSS CENTRAL NC LATE WEDNESDAY
INTO WEDNESDAY NIGHT... LIKELY STALLING JUST TO THE SOUTH OF THE
AREA BY THURSDAY MORNING. NOT EXPECTING TOO MUCH PRECIP FOR
WEDNESDAY AND WEDNESDAY NIGHT. HOWEVER... WE COULD SEE SOME LIGHT
RAIN/SHOWERS ASSOCIATED WITH EITHER A WEAK INVERTED SURFACE TROUGH
ALONG THE COAST IN ADVANCE OF THE FRONT OR PERHAPS ALONG THE COLD
FRONT AS IT MOVES INTO EASTERN/SOUTHEASTERN PORTIONS OF THE RAH CWA.
THUS... WILL ADD A SLIGHT CHANCE FOR SHOWERS ON WEDNESDAY ACROSS THE
SOUTHEAST/EAST.
THE REST OF THE MEDIUM RANGE FORECAST WILL BE DOMINATED BY A
BUILDING/EXTENDING SUBTROPICAL RIDGE ALOFT ACROSS OUR AREA.
MEANWHILE... A LEAD SOUTHERN STREAM CLOSED LOW IS EXPECTED TO SLOWLY
LIFT NORTHEASTWARD FROM NORTHERN MEXICO INTO THE GREAT LAKES REGION
FROM TUESDAY THROUGH FRIDAY. THE RIDGE ALOFT WILL GENERALLY STEER
THE BULK OF THE AFOREMENTIONED SOUTHERN STREAM SYSTEM TO THE NORTH
OF OUR AREA. HOWEVER... A WEAKENING SURFACE COLD FRONT/TROUGH WILL
MAKE IT INTO THE REGION ON FRIDAY INTO FRIDAY NIGHT... YIELDING A
SMALL CHANCE OF SHOWERS... BUT NO REAL TEMPERATURE CHANGE. THE FLOW
PATTERN ALOFT BECOMES EVEN MORE AMPLIFIED NEXT WEEKEND... AS A DEEP
TROUGH IS EXPECTED ACROSS THE WESTERN TWO-THIRDS OF THE COUNTRY...
WITH A STRONG RIDGE ACROSS/NEAR THE EAST COAST.... WITH ANOTHER
EMBEDDED S/W AND SURFACE LOW AGAIN LIFTING FROM THE WEST/SOUTHWEST
U.S. INTO THE GREAT LAKES. GIVEN THE STRONG RIDGE ACROSS THE EAST
COAST... EXPECT THE ASSOCIATED SURFACE COLD FRONT TO REMAIN TO THE
EAST OF CENTRAL NC THROUGH THE FORECAST PERIOD.
TEMPS DURING THE EXTENDED WILL GENERALLY FEATURE A WARMING TREND...
WITH A MINOR SETBACK ON THURSDAY WITH THE COLD FRONT MOVING
INTO/THROUGH THE AREA ON WEDNESDAY/WEDNESDAY NIGHT ASSOCIATED WITH
THE NORTHERN STREAM SYSTEM. IN GENERAL EXPECT HIGH TEMPS IN THE 60S
TO MAYBE EVEN SOME LOW 70S. HOWEVER... WE MAY SEE HIGH TEMPS
THURSDAY IN THE 50S. LOWS WILL SHOW A SIMILAR TREND... GENERALLY IN
THE 40S... WITH PERHAPS EVEN SOME LOW 50S BY SUNDAY MORNING (WHICH
IS NEAR NORMAL HIGH TEMPS).
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
AS OF 610 PM SUNDAY...
A COLD FRONT WILL SWEEP EAST THROUGH THE AREA AT OR SHORTLY AFTER
MIDNIGHT. THIS WILL LEAD TO WEST TO EAST CLEARING...WITH
THE MVFR/IFR STRATUS IN THE EAST SCATTERING OUT BY THAT TIME.
VFR CONDITIONS ARE EXPECTED ON MONDAY AS A PROGRESSIVE SURFACE HIGH
BUILDS OVER THE AREA AND THEN SHIFTS QUICKLY OFFSHORE MONDAY NIGHT.
RESULTANT SOUTHERLY RETURN FLOW COULD LEAD TO A PERIOD OF
SUB-IFR CEILINGS IN STRATUS POSSIBLE LATE MONDAY NIGHT AND
ESPECIALLY TUESDAY NIGHT. INCREASED CLOUDINESS IS EXPECTED
THURSDAY AND FRIDAY WITH SOME ADVERSE AVIATION CONDITIONS
POSSIBLE IN PATCHY LIGHT RAIN.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLAES
NEAR TERM...BLAES
SHORT TERM...BLAES/BSD
LONG TERM...BSD
AVIATION...CBL.BLAES
AREA FORECAST DISCUSSION
NWS RALEIGH NC
314 PM EST SUN JAN 6 2013
.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE WILL MOVE OFF THE CAROLINA COAST THIS
EVENING. A COLD FRONT WILL MOVE ACROSS CENTRAL NORTH CAROLINA
TONIGHT. HIGH PRESSURE WILL BUILD INTO REGION ON MONDAY AND PERSIST
THROUGH TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 220 PM SUNDAY...
AREAS OF PATCHY LIGHT RAIN ACROSS THE FAR SOUTHERN PIEDMONT...
SOUTHERN SANDHILLS AND SOUTHERN COASTAL PLAIN WILL PERSIST ON AND
OFF THROUGH AROUND 03Z. THE LAST BATCH OF RAIN TO MOVE THROUGH THIS
AREA IS CURRENTLY DEVELOPING IN SC WITH INDIVIDUAL ELEMENTS MOVING
QUICKLY NORTHEAST WHILE THE WHOLE AREA SHIFTS EAST. THE FEED OF LOW
LEVEL MOISTURE IS ABATING AS NOTED IN RECENT VWP IMAGERY FROM
COASTAL RADARS AND THE AIRMASS IS BEGINNING TO DRY OUT AT MID LEVELS
ACROSS THE FOOTHILLS AND THE PIEDMONT. HIGH RESOLUTION GUIDANCE
INCLUDING RECENT RUNS OF THE HRRR STILL INDICATE THAT LIGHT RAIN
WILL CONTINUE TO SKIRT THE SOUTHEASTERN THIRD OF THE RAH CWA THROUGH
THE EARLY EVENING HOURS. LATER TONIGHT A COLD FRONT WILL SWEEP
ACROSS CENTRAL NC AHEAD OF A MID TROUGH WHICH WILL RESULT IN
DRAMATIC DRYING AND SUBSIDENCE LATE TONIGHT. EXPECT CLEAR SKIES BY
DAYBREAK WITH THE EXCEPTION OF A FEW MID LEVEL CLOUDS IN THE COASTAL
PLAIN. A COLDER AIR MASS IS ADVECTED INTO THE AREA VERY LATE
ALLOWING LOW TEMPS TO FALL INTO THE 29-35 RANGE. -BLAES
&&
.SHORT TERM /MONDAY AND TUESDAY NIGHT/...
AS OF 3 PM SUNDAY...
SHORT RANGE RIDGING BUILDS INTO THE SOUTHEAST ON MONDAY AND THEN
QUICKLY TRANSLATES OFF THE COAST MONDAY NIGHT. AT THE SURFACE...A
1033MB HIGH PRESSURE SYSTEM ACROSS THE LOWER OH VALLEY MONDAY
MORNING WILL SHIFT EAST AND THEN RIDGE INTO CENTRAL NC FROM THE
COAST LATE MONDAY NIGHT. THE AIR MASS ACROSS CENTRAL NC DURING THE
SHORT RANGE PERIOD WILL BE CHARACTERIZED BY PW VALUES AROUND 0.20
INCHES AND SLIGHTLY BELOW NORMAL TEMPERATURES. SUNNY SKIES ARE
EXPECTED ON MONDAY WITH CLEAR SKIES PERSISTING INTO THE EVENING
HOURS. SOME CIRRUS CLOUDS WILL WORK INTO THE AREA FROM THE WEST LATE
MONDAY NIGHT AS THE UPPER LEVEL RIDGE AXIS SHIFT EAST. IN
ADDITION...A RETURN FLOW NEAR THE SURFACE MAY RESULT IN THE
DEVELOPMENT OF SOME LOW STRATUS THAT WILL MOVE INTO CENTRAL NC FROM
THE SOUTH AND EAST TOWARD DAYBREAK TUESDAY. HIGH TEMPERATURES ON
MONDAY WILL RANGE IN THE 47-54 RANGE WITH OVERNIGHT LOWS BETWEEN 26
AND 31 DEGREES. -BLAES
TUESDAY AND TUESDAY NIGHT:
SURFACE HIGH PRESSURE WILL MOVE FURTHER OFFSHORE ON TUESDAY AND
TUESDAY NIGHT... WHILE CONTINUING TO EXTEND BACK WESTWARD INTO
CENTRAL NC. THIS WILL ALLOW LOW LEVEL MOISTURE RETURN IN A SOUTH TO
NORTH FASHION... BELOW A STRONG SUBSIDENCE INVERSION AT AROUND 850
MB. THIS WILL LEAD TO PARTLY SUNNY TO MOSTLY CLOUDY SKIES ACROSS
SOUTHERN PORTIONS OF THE AREA BY TUESDAY AFTERNOON... WITH LOCATIONS
ACROSS THE NORTH REMAINING MOSTLY TO PARTLY SUNNY. HOWEVER... THE
INCREASE IN LOW LEVEL SOUTHERLY FLOW WILL ALLOW FOR HIGH TEMPS TO BE
SEVERAL DEGREES WARMER THAN HIGHS FROM MONDAY AFTERNOON... DESPITE
THE INCREASING CLOUD COVER. THUS... EXPECT WE WILL SEE HIGH TEMPS
RANGE FROM THE LOWER 50S NW TO UPPER 50S SE.
MOISTURE WILL CONTINUE TO INCREASE ON TUESDAY NIGHT INTO WEDNESDAY
MORNING... WITH PERHAPS A FEW LIGHT SHOWERS ACROSS SOUTHEASTERN
PORTIONS OF THE AREA ASSOCIATED WITH AN INVERTED SURFACE TROUGH NEAR
THE COAST AND POSSIBLE WEAK SURFACE LOW NEAR THE COAST. THUS... WITH
THE INCREASE IN MOISTURE EXPECT LOW TEMPS WEDNESDAY MORNING SHOULD
BE SEVERAL CATEGORIES WARMER THAN THE PREVIOUS MORNING.THIS YIELDS
HIGH RANGING FROM THE MID 30S NORTH (WHERE LOW STRATUS AND FOG
SHOULD BE THE LEAST TO AROUND 40 ACROSS THE SOUTH. -BSD
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 310 PM SUNDAY...
WEDNESDAY THROUGH SUNDAY:
MEDIUM RANGE MODELS ARE COMING INTO BETTER AGREEMENT ON THE OVERALL
UPPER FLOW PATTERN ACROSS THE CONUS DURING THIS PERIOD. HOWEVER...
TIMING AND FINER DETAIL DIFFERENCES STILL EXIST.
EXPECT THE SUBTROPICAL RIDGE TO EXTEND/BUILD ACROSS CENTRAL NC FOR
WEDNESDAY AND THURSDAY... WHILE A NORTHERN STREAM TROUGH TRACKS
ACROSS THE GREAT LAKES AND NORTHEAST. THE NORTHERN STREAM TROUGH
WILL SEND A MOSTLY DRY COLD FRONT ACROSS CENTRAL NC LATE WEDNESDAY
INTO WEDNESDAY NIGHT... LIKELY STALLING JUST TO THE SOUTH OF THE
AREA BY THURSDAY MORNING. NOT EXPECTING TOO MUCH PRECIP FOR
WEDNESDAY AND WEDNESDAY NIGHT. HOWEVER... WE COULD SEE SOME LIGHT
RAIN/SHOWERS ASSOCIATED WITH EITHER A WEAK INVERTED SURFACE TROUGH
ALONG THE COAST IN ADVANCE OF THE FRONT OR PERHAPS ALONG THE COLD
FRONT AS IT MOVES INTO EASTERN/SOUTHEASTERN PORTIONS OF THE RAH CWA.
THUS... WILL ADD A SLIGHT CHANCE FOR SHOWERS ON WEDNESDAY ACROSS THE
SOUTHEAST/EAST.
THE REST OF THE MEDIUM RANGE FORECAST WILL BE DOMINATED BY A
BUILDING/EXTENDING SUBTROPICAL RIDGE ALOFT ACROSS OUR AREA.
MEANWHILE... A LEAD SOUTHERN STREAM CLOSED LOW IS EXPECTED TO SLOWLY
LIFT NORTHEASTWARD FROM NORTHERN MEXICO INTO THE GREAT LAKES REGION
FROM TUESDAY THROUGH FRIDAY. THE RIDGE ALOFT WILL GENERALLY STEER
THE BULK OF THE AFOREMENTIONED SOUTHERN STREAM SYSTEM TO THE NORTH
OF OUR AREA. HOWEVER... A WEAKENING SURFACE COLD FRONT/TROUGH WILL
MAKE IT INTO THE REGION ON FRIDAY INTO FRIDAY NIGHT... YIELDING A
SMALL CHANCE OF SHOWERS... BUT NO REAL TEMPERATURE CHANGE. THE FLOW
PATTERN ALOFT BECOMES EVEN MORE AMPLIFIED NEXT WEEKEND... AS A DEEP
TROUGH IS EXPECTED ACROSS THE WESTERN TWO-THIRDS OF THE COUNTRY...
WITH A STRONG RIDGE ACROSS/NEAR THE EAST COAST.... WITH ANOTHER
EMBEDDED S/W AND SURFACE LOW AGAIN LIFTING FROM THE WEST/SOUTHWEST
U.S. INTO THE GREAT LAKES. GIVEN THE STRONG RIDGE ACROSS THE EAST
COAST... EXPECT THE ASSOCIATED SURFACE COLD FRONT TO REMAIN TO THE
EAST OF CENTRAL NC THROUGH THE FORECAST PERIOD.
TEMPS DURING THE EXTENDED WILL GENERALLY FEATURE A WARMING TREND...
WITH A MINOR SETBACK ON THURSDAY WITH THE COLD FRONT MOVING
INTO/THROUGH THE AREA ON WEDNESDAY/WEDNESDAY NIGHT ASSOCIATED WITH
THE NORTHERN STREAM SYSTEM. IN GENERAL EXPECT HIGH TEMPS IN THE 60S
TO MAYBE EVEN SOME LOW 70S. HOWEVER... WE MAY SEE HIGH TEMPS
THURSDAY IN THE 50S. LOWS WILL SHOW A SIMILAR TREND... GENERALLY IN
THE 40S... WITH PERHAPS EVEN SOME LOW 50S BY SUNDAY MORNING (WHICH
IS NEAR NORMAL HIGH TEMPS).
&&
.AVIATION /18Z SUNDAY THROUGH THURSDAY/...
AS OF 105 PM SUNDAY...
PATCHY LIGHT RAIN WILL CONTINUE THROUGH SUNSET AT KFAY WITH PERIODS
OF MVFR CIGS. A BRIEF PERIOD OF LIGHT RAIN IS POSSIBLE AT KRDU AND
KFAY THIS AFTERNOON. CLEARING MID/HIGH CLOUDS COULD RESULT IN A
PERIOD OF MVFR/IFR STRATUS AFTER MIDNIGHT AT KFAY AND POSSIBLY
KRWI/KRDU. CLEAR SKIES ARE EXPECTED BY DAYBREAK MONDAY. VFR
CONDITIONS WILL PERSIST THROUGH THE TAF PERIOD AT KGSO AND KINT WITH
CIGS OF AROUND 5KFT THIS AFTERNOON LIFTING THIS EVENING. LIGHT
SOUTHWEST/WEST WINDS LESS THAN 6KTS THIS AFTERNOON AND TONIGHT WILL
BECOME NORTHERLY AT 7-10KTS ON MONDAY.
OUTLOOK...HIGH PRESSURE WILL CONTROL THE WEATHER ON SUNDAY THROUGH
MONDAY WITH FAIR WEATHER. A PERIOD OF SUB-IFR CEILINGS IN STRATUS IS
POSSIBLE LATE MONDAY NIGHT AND ESPECIALLY TUESDAY NIGHT. INCREASED
CLOUDINESS IS EXPECTED ON WEDNESDAY AND THURSDAY WITH SOME ADVERSE
AVIATION CONDITIONS POSSIBLE IN PATCHY LIGHT RAIN. -BLAES
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLAES
NEAR TERM...BLAES
SHORT TERM...BLAES/BSD
LONG TERM...BSD
AVIATION...BLAES
AREA FORECAST DISCUSSION
NWS RALEIGH NC
240 PM EST SUN JAN 6 2013
.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE WILL MOVE OFF THE CAROLINA COAST THIS
EVENING. A COLD FRONT WILL MOVE ACROSS CENTRAL NORTH CAROLINA
TONIGHT. HIGH PRESSURE WILL BUILD INTO REGION ON MONDAY AND PERSIST
THROUGH TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 220 PM SUNDAY...
AREAS OF PATCHY LIGHT RAIN ACROSS THE FAR SOUTHERN PIEDMONT...
SOUTHERN SANDHILLS AND SOUTHERN COASTAL PLAIN WILL PERSIST ON AND
OFF THROUGH AROUND 03Z. THE LAST BATCH OF RAIN TO MOVE THROUGH THIS
AREA IS CURRENTLY DEVELOPING IN SC WITH INDIVIDUAL ELEMENTS MOVING
QUICKLY NORTHEAST WHILE THE WHOLE AREA SHIFTS EAST. THE FEED OF LOW
LEVEL MOISTURE IS ABATING AS NOTED IN RECENT VWP IMAGERY FROM
COASTAL RADARS AND THE AIRMASS IS BEGINNING TO DRY OUT AT MID LEVELS
ACROSS THE FOOTHILLS AND THE PIEDMONT. HIGH RESOLUTION GUIDANCE
INCLUDING RECENT RUNS OF THE HRRR STILL INDICATE THAT LIGHT RAIN
WILL CONTINUE TO SKIRT THE SOUTHEASTERN THIRD OF THE RAH CWA THROUGH
THE EARLY EVENING HOURS. LATER TONIGHT A COLD FRONT WILL SWEEP
ACROSS CENTRAL NC AHEAD OF A MID TROUGH WHICH WILL RESULT IN
DRAMATIC DRYING AND SUBSIDENCE LATE TONIGHT. EXPECT CLEAR SKIES BY
DAYBREAK WITH THE EXCEPTION OF A FEW MID LEVEL CLOUDS IN THE COASTAL
PLAIN. A COLDER AIR MASS IS ADVECTED INTO THE AREA VERY LATE
ALLOWING LOW TEMPS TO FALL INTO THE 29-35 RANGE. -BLAES
&&
.SHORT TERM /MONDAY AND MONDAY NIGHT/...
AS OF 240 PM SUNDAY...
SHORT RANGE RIDGING BUILDS INTO THE SOUTHEAST ON MONDAY AND THEN
QUICKLY TRANSLATES OFF THE COAST MONDAY NIGHT. AT THE SURFACE...A
1033MB HIGH PRESSURE SYSTEM ACROSS THE LOWER OH VALLEY MONDAY
MORNING WILL SHIFT EAST AND THEN RIDGE INTO CENTRAL NC FROM THE
COAST LATE MONDAY NIGHT. THE AIR MASS ACROSS CENTRAL NC DURING THE
SHORT RANGE PERIOD WILL BE CHARACTERIZED BY PW VALUES AROUND 0.20
INCHES AND SLIGHTLY BELOW NORMAL TEMPERATURES. SUNNY SKIES ARE
EXPECTED ON MONDAY WITH CLEAR SKIES PERSISTING INTO THE EVENING
HOURS. SOME CIRRUS CLOUDS WILL WORK INTO THE AREA FROM THE WEST LATE
MONDAY NIGHT AS THE UPPER LEVEL RIDGE AXIS SHIFT EAST. IN
ADDITION...A RETURN FLOW NEAR THE SURFACE MAY RESULT IN THE
DEVELOPMENT OF SOME LOW STRATUS THAT WILL MOVE INTO CENTRAL NC FROM
THE SOUTH AND EAST TOWARD DAYBREAK TUESDAY. HIGH TEMPERATURES ON
MONDAY WILL RANGE IN THE 47-54 RANGE WITH OVERNIGHT LOWS BETWEEN 26
AND 31 DEGREES. -BLAES
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 258 AM SUNDAY...
MODEL SOLUTIONS COMING TOGETHER WITH THE TRACK OF THE LOW LATE IN
THE WEEK... MOVING FROM TX ON THURS INTO THE GREAT LAKES FRI. GFS
AND ECMWF STILL SHOWING THE TAIL END OF A NORTHERN STREAM COLD FRONT
ENTERING THE REGION ON THURSDAY... WITH BACKED WINDS BRIEFLY
INDICATED ON FORECAST SOUNDINGS... BEFORE A WARM FRONT SURGES NORTH
ON FRIDAY. THE ASSOCIATED COLD FRONT WILL JUST ENTER THE REGION
OVERNIGHT FRIDAY INTO SATURDAY... BEFORE WASHING OUT. TEMPS WILL BE
HIGHLY DEPENDENT ON THE TIMING AND MOVEMENT OF THESE FRONTAL ZONES
IN THE LATTER PART OF THE WEEK... BUT WILL CONTINUE TO KEEP HIGHS IN
THE 60S... WITH LOWS IN THE 40S. PRECIPITATION DOES NOT APPROACH THE
AREA UNTIL LATER IN THE DAY ON THURSDAY... AND LINGERS THROUGH
FRIDAY.
&&
.AVIATION /18Z SUNDAY THROUGH THURSDAY/...
AS OF 105 PM SUNDAY...
PATCHY LIGHT RAIN WILL CONTINUE THROUGH SUNSET AT KFAY WITH PERIODS
OF MVFR CIGS. A BRIEF PERIOD OF LIGHT RAIN IS POSSIBLE AT KRDU AND
KFAY THIS AFTERNOON. CLEARING MID/HIGH CLOUDS COULD RESULT IN A
PERIOD OF MVFR/IFR STRATUS AFTER MIDNIGHT AT KFAY AND POSSIBLY
KRWI/KRDU. CLEAR SKIES ARE EXPECTED BY DAYBREAK MONDAY. VFR
CONDITIONS WILL PERSIST THROUGH THE TAF PERIOD AT KGSO AND KINT WITH
CIGS OF AROUND 5KFT THIS AFTERNOON LIFTING THIS EVENING. LIGHT
SOUTHWEST/WEST WINDS LESS THAN 6KTS THIS AFTERNOON AND TONIGHT WILL
BECOME NORTHERLY AT 7-10KTS ON MONDAY.
OUTLOOK...HIGH PRESSURE WILL CONTROL THE WEATHER ON SUNDAY THROUGH
MONDAY WITH FAIR WEATHER. A PERIOD OF SUB-IFR CEILINGS IN STRATUS IS
POSSIBLE LATE MONDAY NIGHT AND ESPECIALLY TUESDAY NIGHT. INCREASED
CLOUDINESS IS EXPECTED ON WEDNESDAY AND THURSDAY WITH SOME ADVERSE
AVIATION CONDITIONS POSSIBLE IN PATCHY LIGHT RAIN. -BLAES
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLAES
NEAR TERM...BLAES
SHORT TERM...BLAES
LONG TERM...SEC
AVIATION...BLAES
AREA FORECAST DISCUSSION
NWS RALEIGH NC
220 PM EST SUN JAN 6 2013
.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE WILL MOVE OFF THE CAROLINA COAST THIS
EVENING. A COLD FRONT WILL MOVE ACROSS CENTRAL NORTH CAROLINA
TONIGHT. HIGH PRESSURE WILL BUILD INTO REGION ON MONDAY AND PERSIST
THROUGH TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 220 PM SUNDAY...
AREAS OF PATCHY LIGHT RAIN ACROSS THE FAR SOUTHERN PIEDMONT...
SOUTHERN SANDHILLS AND SOUTHERN COASTAL PLAIN WILL PERSIST ON AND
OFF THROUGH AROUND 03Z. THE LAST BATCH OF RAIN TO MOVE THROUGH THIS
AREA IS CURRENTLY DEVELOPING IN SC WITH INDIVIDUAL ELEMENTS MOVING
QUICKLY NORTHEAST WHILE THE WHOLE AREA SHIFTS EAST. THE FEED OF LOW
LEVEL MOISTURE IS ABATING AS NOTED IN RECENT VWP IMAGERY FROM
COASTAL RADARS AND THE AIRMASS IS BEGINNING TO DRY OUT AT MID LEVELS
ACROSS THE FOOTHILLS AND THE PIEDMONT. HIGH RESOLUTION GUIDANCE
INCLUDING RECENT RUNS OF THE HRRR STILL INDICATE THAT LIGHT RAIN
WILL CONTINUE TO SKIRT THE SOUTHEASTERN THIRD OF THE RAH CWA THROUGH
THE EARLY EVENING HOURS. LATER TONIGHT A COLD FRONT WILL SWEEP
ACROSS CENTRAL NC AHEAD OF A MID TROUGH WHICH WILL RESULT IN
DRAMATIC DRYING AND SUBSIDENCE LATE TONIGHT. EXPECT CLEAR SKIES BY
DAYBREAK WITH THE EXCEPTION OF A FEW MID LEVEL CLOUDS IN THE COASTAL
PLAIN. A COLDER AIR MASS IS ADVECTED INTO THE AREA VERY LATE
ALLOWING LOW TEMPS TO FALL INTO THE 29-35 RANGE. -BLAES
&&
.SHORT TERM /MONDAY AND MONDAY NIGHT/...
AS OF 320 AM SUNDAY...
MODIFIED CONTINENTAL POLAR HIGH PRESSURE WILL BUILD ACROSS AND
LINGER OVER THE MIDDLE ATLANTIC AND CAROLINAS THIS PERIOD...
ASSOCIATED NORTHEASTERLY FLOW DURING THE DAY...AND NIGHTTIME
CALM...WILL RESULT IN BELOW AVERAGE TEMPERATURES IN THE UPPER 40S TO
AROUND 50 AND UPPER 20S...RESPECTIVELY...THE LATTER OF WHICH SHOULD
OCCUR DESPITE INCREASING CIRRUS OVERNIGHT.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 258 AM SUNDAY...
MODEL SOLUTIONS COMING TOGETHER WITH THE TRACK OF THE LOW LATE IN
THE WEEK... MOVING FROM TX ON THURS INTO THE GREAT LAKES FRI. GFS
AND ECMWF STILL SHOWING THE TAIL END OF A NORTHERN STREAM COLD FRONT
ENTERING THE REGION ON THURSDAY... WITH BACKED WINDS BRIEFLY
INDICATED ON FORECAST SOUNDINGS... BEFORE A WARM FRONT SURGES NORTH
ON FRIDAY. THE ASSOCIATED COLD FRONT WILL JUST ENTER THE REGION
OVERNIGHT FRIDAY INTO SATURDAY... BEFORE WASHING OUT. TEMPS WILL BE
HIGHLY DEPENDENT ON THE TIMING AND MOVEMENT OF THESE FRONTAL ZONES
IN THE LATTER PART OF THE WEEK... BUT WILL CONTINUE TO KEEP HIGHS IN
THE 60S... WITH LOWS IN THE 40S. PRECIPITATION DOES NOT APPROACH THE
AREA UNTIL LATER IN THE DAY ON THURSDAY... AND LINGERS THROUGH
FRIDAY.
&&
.AVIATION /18Z SUNDAY THROUGH THURSDAY/...
AS OF 105 PM SUNDAY...
PATCHY LIGHT RAIN WILL CONTINUE THROUGH SUNSET AT KFAY WITH PERIODS
OF MVFR CIGS. A BRIEF PERIOD OF LIGHT RAIN IS POSSIBLE AT KRDU AND
KFAY THIS AFTERNOON. CLEARING MID/HIGH CLOUDS COULD RESULT IN A
PERIOD OF MVFR/IFR STRATUS AFTER MIDNIGHT AT KFAY AND POSSIBLY
KRWI/KRDU. CLEAR SKIES ARE EXPECTED BY DAYBREAK MONDAY. VFR
CONDITIONS WILL PERSIST THROUGH THE TAF PERIOD AT KGSO AND KINT WITH
CIGS OF AROUND 5KFT THIS AFTERNOON LIFTING THIS EVENING. LIGHT
SOUTHWEST/WEST WINDS LESS THAN 6KTS THIS AFTERNOON AND TONIGHT WILL
BECOME NORTHERLY AT 7-10KTS ON MONDAY.
OUTLOOK...HIGH PRESSURE WILL CONTROL THE WEATHER ON SUNDAY THROUGH
MONDAY WITH FAIR WEATHER. A PERIOD OF SUB-IFR CEILINGS IN STRATUS IS
POSSIBLE LATE MONDAY NIGHT AND ESPECIALLY TUESDAY NIGHT. INCREASED
CLOUDINESS IS EXPECTED ON WEDNESDAY AND THURSDAY WITH SOME ADVERSE
AVIATION CONDITIONS POSSIBLE IN PATCHY LIGHT RAIN. -BLAES
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLAES
NEAR TERM...BLAES
SHORT TERM...MWS
LONG TERM...SEC
AVIATION...BLAES
AREA FORECAST DISCUSSION
NWS RALEIGH NC
100 PM EST SUN JAN 6 2013
.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE WILL CROSS THE THE MIDDLE ATLANTIC STATES
TODAY...FOLLOWED BY THE PASSAGE OF A DRY COLD FRONT TONIGHT. HIGH
PRESSURE WILL BUILD INTO...AND REMAIN OVER OUR REGION...THROUGH
TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1055 AM SUNDAY...
AN AREA OF OF LIGHT RAIN FALLING FROM CEILINGS IN THE 3-6KFT RANGE
ACROSS THE SOUTHEASTERN HALF OF THE RAH CWA WILL SHIFT EAST DURING
THE NEXT FEW HOURS. THE KGSO RAOB THIS MORNING WAS NOTABLY DRIER AND
WARMER IN THE LOWEST ~5KFT COMPARED TO RECENT NAM/GFS FCST BUFR
SOUNDINGS AND NOTED MULTIPLE LAYERS OF DRYING ALOFT. RECENT VIS SAT
IMAGES HAVE INDICATED SOME EASTWARD ADVANCEMENT OF THE AREA OF
THINNING CLOUDS IN THE FOOTHILLS WHILE THE REMAINDER OF THE RAH CWA
IS BLANKETED IN OVERCAST SKIES.
EXPECT MOSTLY CLOUDY/CLOUDY SKIES TO PERSIST FOR THE REMAINDER OF
THE DAY WITH AREAS OF VERY LIGHT PRECIPITATION ACROSS THE
SOUTHERN/SOUTHEAST TIER. AFTER THE INITIAL AREA OF RAIN OVER THE
AREA WANES FOR A FEW HOURS AROUND/JUST AFTER MIDDAY...ANOTHER AREA
OF PATCHY LIGHT RAIN IS EXPECTED TO DEVELOP ACROSS SC AND SPREAD
INTO THE FAR SOUTHERN PIEDMONT..THE SOUTHERN SANDHILLS AND THE
SOUTHERN COASTAL PLAIN. THIS AREA OF RAIN IS EXPECTED TO BE
GENERATED THROUGH LOW LEVEL MOISTURE ADVECTION AND SHALLOW LIFT WITH
THE GFS AND TO A LESSER EXTENT THE NAM INDICATING SOME LIGHT QPF.
THE HIGH RES CONVECTION ALLOWING MODELS...ESPECIALLY THE HRRR HAVE
BEEN BULLISH ON ANOTHER SURGE OF PRECIPITATION BUT THE PAST RUN OR
TWO HAVE BACKED OFF A BIT. WOULD NOT CATEGORIZE THE DAY AS A WASHOUT
AS QPF VALUES WILL ONLY BE ON THE ORDER OF A FEW HUNDREDTHS OF AN
INCH. TEMPERATURES WILL BE MODULATED A GREAT DEAL BY THE CLOUDS AND
PRECIPITATION WITH HIGHS IN THE LOWER 50S ACROSS THE WEST/NORTHWEST
PARTS OF FORECAST AREA TO THE UPPER 40S/NEAR 50 EAST. -BLAES
TONIGHT: A POTENT NORTHERN STREAM S/W TROUGH AND ASSOCIATED SURFACE
COLD FRONT WILL SWEEP EASTWARD ACROSS CENTRAL NC. A RENEWED AREA OF
MID CLOUDS...AND LINGERING JET CIRRUS MAY ACCOMPANY THE S/W THROUGH
06Z...BUT STRONG SUBSIDENCE AND RAPID CLEARING/DRYING WILL COMMENCE
THEREAFTER. POST-FRONTAL...CAA-DRIVEN LOWS IN THE UPPER 20S TO
LOWER-MIDDLE 30S. -MWS
&&
.SHORT TERM /MONDAY AND MONDAY NIGHT/...
AS OF 320 AM SUNDAY...
MODIFIED CONTINENTAL POLAR HIGH PRESSURE WILL BUILD ACROSS AND
LINGER OVER THE MIDDLE ATLANTIC AND CAROLINAS THIS PERIOD...
ASSOCIATED NORTHEASTERLY FLOW DURING THE DAY...AND NIGHTTIME
CALM...WILL RESULT IN BELOW AVERAGE TEMPERATURES IN THE UPPER 40S TO
AROUND 50 AND UPPER 20S...RESPECTIVELY...THE LATTER OF WHICH SHOULD
OCCUR DESPITE INCREASING CIRRUS OVERNIGHT.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 258 AM SUNDAY...
MODEL SOLUTIONS COMING TOGETHER WITH THE TRACK OF THE LOW LATE IN
THE WEEK... MOVING FROM TX ON THURS INTO THE GREAT LAKES FRI. GFS
AND ECMWF STILL SHOWING THE TAIL END OF A NORTHERN STREAM COLD FRONT
ENTERING THE REGION ON THURSDAY... WITH BACKED WINDS BRIEFLY
INDICATED ON FORECAST SOUNDINGS... BEFORE A WARM FRONT SURGES NORTH
ON FRIDAY. THE ASSOCIATED COLD FRONT WILL JUST ENTER THE REGION
OVERNIGHT FRIDAY INTO SATURDAY... BEFORE WASHING OUT. TEMPS WILL BE
HIGHLY DEPENDENT ON THE TIMING AND MOVEMENT OF THESE FRONTAL ZONES
IN THE LATTER PART OF THE WEEK... BUT WILL CONTINUE TO KEEP HIGHS IN
THE 60S... WITH LOWS IN THE 40S. PRECIPITATION DOES NOT APPROACH THE
AREA UNTIL LATER IN THE DAY ON THURSDAY... AND LINGERS THROUGH
FRIDAY.
&&
.AVIATION /18Z SUNDAY THROUGH THURSDAY/...
AS OF 105 PM SUNDAY...
PATCHY LIGHT RAIN WILL CONTINUE THROUGH SUNSET AT KFAY WITH PERIODS
OF MVFR CIGS. A BRIEF PERIOD OF LIGHT RAIN IS POSSIBLE AT KRDU AND
KFAY THIS AFTERNOON. CLEARING MID/HIGH CLOUDS COULD RESULT IN A
PERIOD OF MVFR/IFR STRATUS AFTER MIDNIGHT AT KFAY AND POSSIBLY
KRWI/KRDU. CLEAR SKIES ARE EXPECTED BY DAYBREAK MONDAY. VFR
CONDITIONS WILL PERSIST THROUGH THE TAF PERIOD AT KGSO AND KINT WITH
CIGS OF AROUND 5KFT THIS AFTERNOON LIFTING THIS EVENING. LIGHT
SOUTHWEST/WEST WINDS LESS THAN 6KTS THIS AFTERNOON AND TONIGHT WILL
BECOME NORTHERLY AT 7-10KTS ON MONDAY.
OUTLOOK...HIGH PRESSURE WILL CONTROL THE WEATHER ON SUNDAY THROUGH
MONDAY WITH FAIR WEATHER. A PERIOD OF SUB-IFR CEILINGS IN STRATUS IS
POSSIBLE LATE MONDAY NIGHT AND ESPECIALLY TUESDAY NIGHT. INCREASED
CLOUDINESS IS EXPECTED ON WEDNESDAY AND THURSDAY WITH SOME ADVERSE
AVIATION CONDITIONS POSSIBLE IN PATCHY LIGHT RAIN. -BLAES
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...BLAES/MWS
SHORT TERM...MWS
LONG TERM...SEC
AVIATION...BLAES
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
639 AM CST SAT JAN 5 2013
.DISCUSSION...VISIBILITY ACROSS MUCH OF EASTERN NORTH DAKOTA HAS
IMPROVED AND NOW MAINLY A LOW STRATUS EVENT. WINDS EXPECTED TO
INCREASE FROM THE NORTH OVER THE NEXT FEW HOURS ENDING THE DENSE
FOG THREAT. WILL CANCEL THE ADVISORY.
&&
.AVIATION...NOT A HIGH CONFIDENCE FORECAST. AN AREA OF LIFR
CIGS WILL AFFECT EASTERN NORTH DAKOTA...BUT SHOULD ADVECT SOUTH
DURING THE MORNING HOURS AS WINDS BECOME NORTHERLY. BAND OF
MVFR/IFR CIGS EXPECTED TO PROPAGATE FROM WEST TO EAST THIS
EVENING. WILL NEED TO UPDATE WITH DETAILS WHEN/IF CONFIDENCE
INCREASES.
&&
.PREV DISCUSSION... /ISSUED 311 AM CST SAT JAN 5 2013/
SHORT TERM...CHALLENGES WILL BE FOG THIS MORNING...AND THEN
CLOUD TRENDS AND TEMPERATURES FOR THE REMAINDER OF THE PERIOD.
00Z MODELS IN DECENT AGREEMENT AND WILL USE A BLEND FOR DETAILS.
A WEAK SFC LOW IS APPROACHING FROM THE WEST AND WILL MOVE THROUGH
THE FA THIS MORNING. AN AREA OF DENSE FOG HAS DEVELOPED ACROSS
EASTERN NORTH DAKOTA. WINDS REMAIN LIGHT UNTIL AFTER THE SFC LOW
PASSES...SO HAVE ISSUED A DENSE FOG ADVISORY. 06Z HRRR HAS A GOOD
HANDLE ON CURRENT FOG CONDITIONS...AND IMPROVES VSBY ONCE WINDS
INCREASE FROM THE NORTH. LOW CONFIDENCE IN CLOUD TRENDS TODAY.
RAP/HRRR SHOW THE MOST PROBABLE SCENARIO...WITH MOST AREAS CLOUDY
TODAY AND POSSIBLE CLEARING ACROSS THE NORTH CENTRAL FA. MAX TEMPS
WILL BE TRICKY AND DEPENDENT ON CLOUDS...BUT DO NOT EXPECT A LARGE
RISE WITH NORTHERLY LOW LEVEL FLOW...AND VALUES SHOULD BE AROUND
NORMAL.
NORTHERLY UPPER LEVEL FLOW TONIGHT BECOMES MORE ZONAL BY LATER ON
SUNDAY. THERE WILL BE ANOTHER UPPER WAVE THAT SHOULD PROVIDE
CLOUDS AND MAYBE FLURRIES TO THE NE FA TONIGHT. A STRONGER SYSTEM
WILL MOVE ACROSS CANADA SUNDAY NIGHT THROUGH MONDAY NIGHT. NEAR
NORMAL TEMPERATURES THROUGH SUNDAY WILL BECOME ABOVE NORMAL
MONDAY. STRONGER WESTERLY LOW LEVEL FLOW EXPECTED ON MONDAY...AND
RAISED MAX TEMPS TO NEAR FREEZING. EXPECT ALL MEASURABLE PRECIP TO
REMAIN NORTH OF THE INTERNATIONAL BORDER.
LONG TERM (TUESDAY-FRIDAY)...THE OPERATIONAL MODELS HAVE COME
INTO SOMEWHAT BETTER AGREEMENT WITH THE PATTERN EVOLUTION DURING
THIS PERIOD. THE 00Z GFS HAS TRENDED TOWARDS THE SLOWER ECMWF
SOLUTION WITH A CLOSED LOW FORECAST TO EJECT FROM THE DESERT
SOUTHWEST INTO THE SOUTHERN PLAINS BY MID-WEEK. MEANWHILE...THE
NORTHERN PLAINS WILL STILL BE UNDER THE INFLUENCE OF A FAIRLY
ZONAL NORTHERN BRANCH OF THE JET FOR THE FIRST HALF OF THE PERIOD.
THIS WILL KEEP SEASONABLY MILD TEMPS IN PLACE FOR MUCH OF THE WORK
WEEK...WITH HIGHS IN THE 20S TO LOW 30S...AND LOWS IN THE TEENS.
THE 00Z GFS/ECMWF/GEM ALL BRING A SHORTWAVE TROUGH ACROSS THE
REGION ON TUESDAY...WITH THE GFS FARTHEST SOUTH AND THE ECMWF LESS
AMPLIFIED AND FARTHER NORTH WITH THE WAVE. A BIT OF LIGHT SNOW IS
POSSIBLE WITH THIS SYSTEM...ALTHOUGH MOISTURE AND FORCING WILL BE
LIMITED.
BY THURSDAY THE UPPER FLOW IS EXPECTED TO BECOME MORE SOUTHWESTERLY
IN RESPONSE TO THE DEVELOPMENT OF A BROAD LONGWAVE TROUGH ACROSS THE
WEST. WILL CONTINUE WITH LOW POPS THURSDAY WITH LOW-LEVEL BAROCLINIC
ZONE NEARBY AND WEAK WAVES RIPPLING THROUGH THE FLOW. UNCERTAINTY
REMAINS THOUGH REGARDING THE EVOLUTION OF THE UPPER TROUGH AS WELL
AS THE CLOSED LOW LIFTING OUT OF THE SOUTHERN PLAINS. COLDER TEMPS
WILL START TO WORK SOUTH LATE IN THE WEEK.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
TG/MAKOWSKI
AREA FORECAST DISCUSSION
NWS BISMARCK ND
320 AM CST SAT JAN 5 2013
.SHORT TERM...TODAY THROUGH SUNDAY...
THE HIGHLIGHTS OF THE SHORT TERM FORECAST ARE DENSE FOG ACROSS THE
EASTERN PORTIONS OF THE CWA THIS MORNING AND THE BEGINNING OF A
STRETCH OF ABOVE NORMAL TEMPERATURES STARING SUNDAY.
ISSUED A DENSE FOG ADVISORY FOR PORTIONS OF THE JAMES RIVER VALLEY
AND THE TURTLE MOUNTAINS THROUGH 16 UTC THIS MORNING. A STRONG
INVERSION ALONG AND EAST OF THE TERMINAL MORAINE HAS TRAPPED LOW
LEVEL MOISTURE AND LEAD TO THE DEVELOPMENT OF DENSE FOG. THE
LATEST HRRR VISIBILITY FORECASTS DEPICT THE DENSE FOG BECOMING
MORE WIDESPREAD EAST OF THE TERMINAL MORAINE...WHICH IS SUPPORTED
BY THE LATEST 11-3.9 SATELLITE TRENDS. WILL CONTINUE TO MONITOR
SHOULD A WESTWARD EXPANSION OF THE ADVISORY BECOME NECESSARY.
COOLER CONDITIONS ARE EXPECTED ACROSS WESTERN AND CENTRAL NORTH
DAKOTA TODAY IN THE WAKE OF A WEAK SURFACE LOW THAT WILL QUICKLY
PROPAGATE INTO CENTRAL MINNESOTA THIS AFTERNOON. THE OVERALL
SPREAD BETWEEN THE STATISTICAL AND DETERMINISTIC GUIDANCE IN
REGARDS TO HIGH TEMPERATURES FOR TODAY IS SMALL...AND WILL THUS
USE A BLEND. NORTHWESTERLY WIND GUSTS IN THE WAKE OF A COLD FRONT
MAY APPROACH 30 KTS THIS MORNING ACROSS SOUTHWEST NORTH
DAKOTA. HOWEVER...A RATHER SHALLOW POST FRONTAL MIXED LAYER
SUGGESTS THAT HIGHER MOMENTUM AIR WILL REMAIN IN THE INVERSION
LAYER...AND THUS...ADVISORY LEVEL WIND GUSTS OF 35+ KTS ARE NOT
ANTICIPATED. FINALLY...DID MAINTAIN THE MENTION OF ISOLATED
MORNING FLURRIES FOR MUCH OF THE AREA AS BROKEN DECKS OF LOW LEVEL
STRATUS IN THE WAKE OF THE LOW SPREAD ACROSS THE CWA.
TEMPERATURES CLIMB ON SUNDAY IN THE WARM SECTOR OF A SURFACE LOW
ACROSS EASTERN SASKATCHEWAN. GIVEN A LOW LEVEL WARM AIR ADVECTION
REGIME IN SOUTHERLY FLOW...THE CHALLENGE IS HOW MUCH WARM AIR CAN
BE MIXED TO THE SURFACE FROM AN INVERSION THAT WILL BE REINFORCED
BY THE SNOWPACK. THE TREND THE PAST COUPLE OF DAYS IN A SIMILIAR
SETUP HAS BEEN FOR THE STATISTICAL GUIDANCE TO BE ABOUT 3 TO 5
DEGREES TOO WARM...AND THE DETERMINISTIC MODELS TO ABOUT THE SAME
AMOUNT TOO COLD. THUS WILL USE A BLEND OF THE TWO GUIDANCE SUITES
WHICH YIELDS HIGHS IN THE LOWER 20S ACROSS THE JAMES RIVER VALLEY
WHERE THE LEAST MIXING IS EXPECTED...TO THE LOW TO MID 30S ACROSS
THE FAR WEST WHERE WINDS TURN SOUTHWEST AHEAD OF AN ADVANCING COLD
FRONT WHICH SHOULD ALLOW FOR GREATER MIXING HEIGHTS TO BE
ACHIEVED.
.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY...
AS HAS BEEN THE CASE THIS ENTIRE WINTER SEASON...THE LATEST GFS HAS
NOW COME IN LINE WITH THE MORE STABLE ECMWF SOLUTION WITH RESPECT TO
THE SYNOPTIC PATTERN OVER THE CONUS FOR THE FIRST HALF OF NEXT WEEK.
THERE IS NOW HIGHER CONFIDENCE IN A DRY FORECAST MONDAY WITH A
CUT-OFF LOW TRAVERSING THE DESERT SOUTHWEST AND NORTHWESTERLY FLOW
ALOFT OVER THE NORTHERN PLAINS. ABOVE NORMAL TEMPERATURES ARE ALSO
EXPECTED MONDAY.
THE LATEST GFS/GEM/ECMWF ARE NOW CONSISTENT WITH PROGGING A
SHORTWAVE EJECTING FROM THE NORTHERN ROCKIES INTO NORTH DAKOTA
TUESDAY. IT APPEARS THE STRONGEST FORCING SHOULD DEVELOP OVER
NORTHERN NORTH DAKOTA TUESDAY. A SLIGHT CHANCE FOR SNOW SHOWERS IS
FORECAST FOR NORTHWEST AND NORTH CENTRAL AS A RESULT. TEMPS ARE
EXPECTED TO REMAIN ABOVE NORMAL TUESDAY.
ANOTHER SHORTWAVE IS EXPECTED TO CLIP THE NORTHWESTERN PORTIONS OF
THE STATE WEDNESDAY. THE THERMAL PROFILE AHEAD OF THIS FEATURE IS
PROGGED TO BE ONE CONDUCIVE FOR A WINTRY MIX OF PRECIPITATION
NORTHWEST LATE WEDNESDAY. ABOVE NORMAL TEMPERATURES ARE EXPECTED TO
CONTINUE.
BY THURSDAY...A POSITIVELY TILTED LONGWAVE TROUGH AXIS IS PROGGED TO
DEVELOP AND EXTEND FROM SASKATCHEWAN SOUTHWEST INTO CENTRAL
CALIFORNIA. ITS ATTENDANT COLD FRONT IS FORECAST TO SWEEP ACROSS THE
CWA THURSDAY BRINGING A SLIGHT CHANCE OF A WINTRY MIX OF
PRECIPITATION WEST AND CENTRAL. THE WINTRY MIX SHOULD TRANSITION TO
SNOW LATE THURSDAY AS MUCH COLDER ARCTIC AIR FILTERS INTO THE REGION.
DRY CONDITIONS ARE EXPECTED FRIDAY. HOWEVER...ARCTIC AIR WILL
CONTINUE TO INFILTRATE THE REGION WITH WELL BELOW NORMAL
TEMPERATURES EXPECTED FRIDAY.
&&
.AVIATION...
PATCHY DENSE FOG IS EXPECTED TO CONTINUE TO DEVELOP NEAR
KJMS THIS MORNING. PREVAILING CONDITIONS WILL LIKELY MVFR/IFR UNTIL
SUNRISE. FURTHERMORE...MVFR CIGS OVER KISN COULD EXPAND INTO
KMOT/KDIK/KBIS BY SUNRISE THIS MORNING. OTHERWISE...VFR CONDITIONS
ARE EXPECTED TO DEVELOP AREA WIDE BY LATE MORNING. INCREASING
NORTHWESTERLY WINDS COULD GUST UP TO 25 KNOTS BY MIDDAY. THE WINDS
SHOULD SUBSIDE BY THIS EVENING WITH VFR CONDITIONS CONTINUING
OVERNIGHT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR NDZ004-005-
013-023-025-037.
&&
$$
SHORT TERM...AYD
LONG TERM/AVIATION...TM
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
311 AM CST SAT JAN 5 2013
.SHORT TERM...CHALLENGES WILL BE FOG THIS MORNING...AND THEN
CLOUD TRENDS AND TEMPERATURES FOR THE REMAINDER OF THE PERIOD.
00Z MODELS IN DECENT AGREEMENT AND WILL USE A BLEND FOR DETAILS.
A WEAK SFC LOW IS APPROACHING FROM THE WEST AND WILL MOVE THROUGH
THE FA THIS MORNING. AN AREA OF DENSE FOG HAS DEVELOPED ACROSS
EASTERN NORTH DAKOTA. WINDS REMAIN LIGHT UNTIL AFTER THE SFC LOW
PASSES...SO HAVE ISSUED A DENSE FOG ADVISORY. 06Z HRRR HAS A GOOD
HANDLE ON CURRENT FOG CONDITIONS...AND IMPROVES VSBY ONCE WINDS
INCREASE FROM THE NORTH. LOW CONFIDENCE IN CLOUD TRENDS TODAY.
RAP/HRRR SHOW THE MOST PROBABLE SCENARIO...WITH MOST AREAS CLOUDY
TODAY AND POSSIBLE CLEARING ACROSS THE NORTH CENTRAL FA. MAX TEMPS
WILL BE TRICKY AND DEPENDENT ON CLOUDS...BUT DO NOT EXPECT A LARGE
RISE WITH NORTHERLY LOW LEVEL FLOW...AND VALUES SHOULD BE AROUND
NORMAL.
NORTHERLY UPPER LEVEL FLOW TONIGHT BECOMES MORE ZONAL BY LATER ON
SUNDAY. THERE WILL BE ANOTHER UPPER WAVE THAT SHOULD PROVIDE
CLOUDS AND MAYBE FLURRIES TO THE NE FA TONIGHT. A STRONGER SYSTEM
WILL MOVE ACROSS CANADA SUNDAY NIGHT THROUGH MONDAY NIGHT. NEAR
NORMAL TEMPERATURES THROUGH SUNDAY WILL BECOME ABOVE NORMAL
MONDAY. STRONGER WESTERLY LOW LEVEL FLOW EXPECTED ON MONDAY...AND
RAISED MAX TEMPS TO NEAR FREEZING. EXPECT ALL MEASURABLE PRECIP TO
REMAIN NORTH OF THE INTERNATIONAL BORDER.
.LONG TERM (TUESDAY-FRIDAY)...THE OPERATIONAL MODELS HAVE COME
INTO SOMEWHAT BETTER AGREEMENT WITH THE PATTERN EVOLUTION DURING
THIS PERIOD. THE 00Z GFS HAS TRENDED TOWARDS THE SLOWER ECMWF
SOLUTION WITH A CLOSED LOW FORECAST TO EJECT FROM THE DESERT
SOUTHWEST INTO THE SOUTHERN PLAINS BY MID-WEEK. MEANWHILE...THE
NORTHERN PLAINS WILL STILL BE UNDER THE INFLUENCE OF A FAIRLY
ZONAL NORTHERN BRANCH OF THE JET FOR THE FIRST HALF OF THE PERIOD.
THIS WILL KEEP SEASONABLY MILD TEMPS IN PLACE FOR MUCH OF THE WORK
WEEK...WITH HIGHS IN THE 20S TO LOW 30S...AND LOWS IN THE TEENS.
THE 00Z GFS/ECMWF/GEM ALL BRING A SHORTWAVE TROUGH ACROSS THE
REGION ON TUESDAY...WITH THE GFS FARTHEST SOUTH AND THE ECMWF LESS
AMPLIFIED AND FARTHER NORTH WITH THE WAVE. A BIT OF LIGHT SNOW IS
POSSIBLE WITH THIS SYSTEM...ALTHOUGH MOISTURE AND FORCING WILL BE
LIMITED.
BY THURSDAY THE UPPER FLOW IS EXPECTED TO BECOME MORE SOUTHWESTERLY
IN RESPONSE TO THE DEVELOPMENT OF A BROAD LONGWAVE TROUGH ACROSS THE
WEST. WILL CONTINUE WITH LOW POPS THURSDAY WITH LOW-LEVEL BAROCLINIC
ZONE NEARBY AND WEAK WAVES RIPPLING THROUGH THE FLOW. UNCERTAINTY
REMAINS THOUGH REGARDING THE EVOLUTION OF THE UPPER TROUGH AS WELL
AS THE CLOSED LOW LIFTING OUT OF THE SOUTHERN PLAINS. COLDER TEMPS
WILL START TO WORK SOUTH LATE IN THE WEEK.
&&
.AVIATION...NOT A HIGH CONFIDENCE FORECAST PAST 15Z. AN AREA OF
LIFR CONDITIONS WITH FOG WILL AFFECT KDVL AND KGFK THROUGH ABOUT
15Z. WINDS BECOME NORTHERLY TODAY...AND NOT SURE HOW WIDESPREAD
IFR/MVFR CIGS WILL BECOME. RAP/HRRR INDICATE THESE CIGS WILL
REMAIN WEST OF THE VALLEY AND AFFECT ONLY KDVL. WILL MONITOR
UPSTREAM OBSERVATIONS AND LATEST MODEL GUIDANCE AND INCLUDE IN THE
FORECAST WHEN/IF CONFIDENCE INCREASES.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR NDZ006>008-
014>016-024-026>030-038-039-054.
MN...NONE.
&&
$$
TG/MAKOWSKI
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1223 AM EST SAT JAN 5 2013
.SYNOPSIS...
SURFACE HIGH PRESSURE TONIGHT. TWO MID/UPPER LEVEL TROUGHS PASS THIS
WEEKEND. HIGH PRESSURE THEN BUILDS IN...MONDAY AND EARLY WEDNESDAY.
LOW PRESSURE BRINGS RAIN SHOWERS LATE WEDNESDAY NIGHT AND THURSDAY.
&&
.NEAR TERM /THROUGH TODAY/...
1215AM UPDATE... STILL SOME LINGERING CLOUDS ACROSS NORTHERN
MOUNTAINOUS COUNTIES...WHICH WILL GRADUALLY DISSIPATE THROUGH THE
REST OF THE NIGHT. LOOKS LIKE SNOWSHOE MAY ALREADY BE STARTING ITS
NON-DIURNAL TREND AS 850 WAA TAKES OVER...SO MADE SOME MINOR
TWEAKS TO GO WITH SLOW WARMING THERE.
PREVIOUS DISCUSSION...
USED RAP AND VIS SAT TRENDS AS BASE FOR TIMING IMPROVING SKY
CONDITION INTO TONIGHT. THINK AREAS ALONG AND E OF I79 CORRIDOR
WILL KEEP CLDS WITH N MTNS HOLDING ON UNTIL PERHAPS 15Z. LOWS
TONIGHT TRICKY ONCE AGAIN AND WILL DEPEND ON EXTENT OF CLEARING
AND BL PUFF. LAMP GUIDANCE CONT TO BE ON WARM SIDE...LKLY OWING TO
BL PUFF AND ALSO CLDS ACROSS THE MTNS. DEEPER VALLEYS/HOLLOWS MAY
DECOUPLE THOUGH...GIVING UPPER TEENS. WILL LEAN TOWARD LAMP WHICH
HAS PERFORMED BETTER OVER RECENT COLD BIAS IN MET/MAV AND
INCORPORATE A COLDER SOLUTION FOR TYPICAL COLD SPOTS OUTSIDE OF
THE CLDS.
ANY REMAINING STRATUS ACROSS N MTNS WILL SCT OUT BY LATE
MORNING. SOME HIGH CLDS WILL BE ROLLING IN AFTN FROM SW...HELPING
TO PUT A FILTER ON SUNSHINE. KEPT POPS OUT THROUGH 00Z...WITH DRY
LLVLS IN PLACE. HOWEVER...MAY SEE ENOUGH TOP DOWN MOISTENING FOR
SOME LIGHT PCPN ACROSS SW VA BY 00Z.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY/...
UPPER SPLIT FLOW PATTERN CONTINUES. MODELS IN GOOD AGREEMENT ON
SOUTHERN STREAM UPPER LOW OVER THE SOUTHWEST U.S. WEAKENING AS IT
OPENS UP...AND LIFTS NORTHEASTWARD ACROSS THE OHIO VALLEY SATURDAY
NIGHT IN CONFLUENT FLOW ALOFT. THIS SYSTEM IS FORECAST TO BE TOO
WEAK TO LIFT THE BAROCLINIC ZONE...STILL ACROSS THE SOUTHEASTERN
STATES...NORTHWARD ENOUGH TO AFFECT ALL BUT THE SOUTHEAST PORTION
OUR AREA. WITH THE VORT CENTER OF THE SYSTEM TRACKING ACROSS THE
MIDDLE OHIO VALLEY INTO THE GREAT LAKES...THE EFFECTS OF ITS
DYNAMICS WILL MAINLY CLIP OUR SOUTHEAST OHIO ZONES. THUS...AS A
WHOLE...OUR AREA LOOKS TO BE IN A MIN FOR QPF. WILL KEEP LOW POPS
ACROSS THE AREA SATURDAY NIGHT...WITH THE BEST CHANCE OVER THE
NORTHWEST AND SOUTHEAST AREAS. DRY SLOW MOVES IN BY SUNDAY MORNING
AS THE SOUTHERN STREAM SYSTEM DEPARTS WITH A BREAK IN THE PRECIP.
DURING SUNDAY...A NORTHERN STEAM UPPER TROUGH AND COLD FRONT DROPS
RAPIDLY SOUTHEAST ACROSS THE AREA SUNDAY AFTERNOON...BRINGING
SCATTERED RAIN SHOWERS...CHANGING TO SNOW SHOWERS BEFORE ENDING
SUNDAY NIGHT. AGAIN...EXPECT LIGHT QPF WITH ANY SNOW ACCUMULATIONS
LIMITED TO MAINLY THE NORTHERN MOUNTAINS...GENERALLY AN INCH OR TWO
BY MONDAY MORNING.
BEHIND THIS QUICK HITTER WILL BE HIGH PRESSURE FOR MONDAY WITH
INCREASING SUNSHINE. MAX TEMPERATURES SUNDAY AND MONDAY AFTERNOON
WILL BE SIMILAR IN THE LOW TO MID 40S...SUNDAY MAINLY
DUE TO THE CLOUDS AND MONDAY MAINLY DUE TO THE SUNSHINE.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
HIGH PRESSURE REMAINS IN CONTROL MONDAY NIGHT AND TUESDAY TO PROVIDE
DRY CONDITIONS.
A DEVELOPING LOW PRESSURE SYSTEM WILL APPROACH FROM THE WEST
WEDNESDAY NIGHT. DIFFERENCES BETWEEN THE ECMWF AND GFS EXIST. THE
ECMWF IS THE PREFERRED MODELS WITH A LOW LATITUDE CYCLONE BECOMING
LESS PROGRESSIVE...WITH SFC LOW TRACK MOVING FROM THE CENTRAL PLAINS
NORTHEAST INTO THE GREAT LAKES REGION...CONTRARY TO THE GFS THAT
DEVELOPS THE LOW OVER THE SOUTHERN PLAINS...TRACKING THE LOW
OVERHEAD WV.
THEREFORE...MINOR TWEAKS WHERE NEEDED FROM PREVIOUS FORECAST...WITH
CHANCES OF RAIN SHOWERS SPREADING FROM WEST TO EAST LATE WEDNESDAY
NIGHT...WITH THE BULK OF PCPN OCCURRING ON THURSDAY.
TEMPERATURE PROFILES AND BOUNDARY LAYER SOUTHWEST FLOW SUGGEST ALL
PCPN STARTING AS LIQUID BY 15Z THURSDAY. THEREFORE...HIGHEST POPS
WHERE CODED ON THURSDAY. ECMWF H850 STRENGTHENING SOUTH TO SOUTHWEST
FLOW AROUND 50 KNOTS...AND TEMPERATURES NEAR 11C BY 18Z
THURSDAY...SUPPORT A GRADUAL WARMING TREND THRU THURSDAY AFTERNOON.
DECREASED POPS BY 06Z FRIDAY...WITH CHANCE POPS MAINLY OVER NORTHERN
AND EASTERN MOUNTAINS. DRIER AIR MASS EXPECTED BY MID FRIDAY MORNING
WITH PCPN EXITING NORTHEAST.
WENT GENERALLY WITH HPC GUIDANCE FOR TEMPERATURES ADDING FEW LOCAL
DETAILS.
&&
.AVIATION /05Z SATURDAY THROUGH WEDNESDAY/...
JUST A SMALL PATCH OF MVFR STRATUS REMAINS ACROSS THE NORTHERN
MOUNTAINS. SO MVFR LINGERING AT KEKN THROUGH THE NIGHT WITH VFR
ELSEWHERE. CLOUDS WILL INCREASE AGAIN THIS AFTERNOON INTO
TONIGHT...WITH SOME MVFR CEILINGS POSSIBLY SNEAKING INTO THE
HIGHER TERRAIN BY THE END OF THE TAF PERIOD. ALSO POSSIBLE LIGHT
RAIN OR SNOW SHOWERS ENTERING FORECAST AREA AFTER 00Z. IN GENERAL
LOOKING AT CALM TO LIGHT SW FLOW INTO TONIGHT.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z SUNDAY...
FORECAST CONFIDENCE: HIGH.
ALTERNATE SCENARIOS: TIMING OF BREAKUP OF CLOUDS OVER THE NORTHERN
MOUNTAINS MAY VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE SAT 01/05/13
UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
EST 1HRLY 01 02 03 04 05 06 07 08 09 10 11 12
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY L L L L L L L H H H H H
PKB CONSISTENCY H H H H L L L L L L L H
CKB CONSISTENCY H H L L L L L L L L L H
AFTER 06Z SUNDAY...
NO WIDESPREAD IFR CONDITIONS EXPECTED.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/JMV/30
NEAR TERM...MZ/30
SHORT TERM...JMV
LONG TERM...ARJ
AVIATION...MZ
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
342 PM CST SAT JAN 5 2013
.DISCUSSION.../ISSUED AT 342 PM CST/
UPPER WAVE PUSHING ACROSS THE DAKOTAS THIS AFTERNOON...DRIVING COLD
FRONT INTO THE FAR EASTERN PORTIONS OF THE STATE AT MID AFTERNOON.
CLOUDS PUSHING IN WITH STRONG COLD AIR ADVECTION...AND WITH OFF
SURFACE TEMPS FALLING QUICKLY TOWARD THOSE FAVORING ICE NUCLEATION...
HAVE SEEN FLURRIES DROP IN TO PARTS OF EAST CENTRAL SOUTH DAKOTA.
THE CLOUDS AND FLURRIES WILL CONTINUE TO PUSH EAST AND SOUTHEAST
THIS EVENING...BUT IT IS CERTAINLY A CHALLENGE AS TO HOW QUICKLY TO
BRING IN A MORE PERMANENT CLEARING. RAP AND 18Z NAM ARE NOW IN
FAVOR OF HANGING BACK A PERIOD OF LOWER CLOUDS LATER INTO THE NIGHT
NEAR/WEST OF THE JAMES RIVER AND THEN DRIFTING EAST AS FLOW ALOFT
STARTS TO TURN A BIT MORE WESTERLY. THIS ALSO PRESENTS A LARGE
CHALLENGE TO TEMPERATURES...WHICH WILL PROVE ALMOST IMPOSSIBLE TO
GET CLOSE ON AN HOURLY TIME FRAME WITH IN AND OUT CLOUD TRENDS.
EXPECT A BETTER PUSH OF CLEARING THROUGH THE EASTERN CWA BY LATER
EVENING...BUT ENOUGH WIND OR A FEW MORE CLOUDS LIKELY TO KEEP TEMPS
FROM PLUNGING TOO FAR ANYWHERE. GENERALLY LOOKING FOR QUITE A FEW
SINGLE DIGITS...WITH READINGS AROUND 10 WEST AS WARMER AIR SHUNTS
EAST FAIRLY QUICKLY.
SUNDAY AGAIN PRESENTS A SMALL CHALLENGE TO TEMPS...WITH A VERY
WEAK GRADIENT THROUGH MIDDAY OR EVEN EARLY AFTERNOON IN THE FAR
SOUTHEAST. LOWER ELEVATION LOCATIONS COULD EASILY ONCE AGAIN FIND
THEMSELVES MIRED IN CHILLIER AIR...WITH THE INCREASING SOUTHERLY
GRADIENT MAINLY ACROSS SOUTHEAST SOUTH DAKOTA AND INTO SOUTHWEST
MINNESOTA DURING THE AFTERNOON. HIGH CLOUDS PUSHING ACROSS WOULD
ONLY ENHANCE THE POTENTIAL FOR THIS TO OCCUR...SO WAS CAREFUL TO
NOT WARM CONDITIONS IN THE EAST TOO MUCH...AND DID NUDGE SOME
TEMPERATURES DOWN ACROSS PARTS OF NW IA. THE WEST WILL BE OPEN TO
SOME BETTER WARMING...BUT EVEN THERE THE INVERSION WILL PRESENT A
BIT OF A CHALLENGE TO LOWER ELEVATION WARMING. /CHAPMAN
THE PATTERN OF MILD WEATHER WILL CONTINUE THROUGH MUCH OF THE WEEK
AS A MORE ZONAL PATTERN SETS UP FOR THE FIRST HALF OF THE WORK WEEK.
MILDER WEST TO SOUTHWEST FLOW WILL MAKE TEMPERATURES QUITE TRICKY TO
PINPOINT...PARTICULARLY REGARDING OVERNIGHT LOWS. FOR SUNDAY
NIGHT...BREEZY SOUTH TO SOUTHWEST WINDS WILL LIKELY RESULT IN A
NON-DIURNAL TEMPERATURE TREND WITH LOWS EXPECTED IN THE EVENING OR
SHORTLY AFTER MIDNIGHT...THEN SLOWLY RISING LATE. THE QUESTION IS
HOW COOL WE WILL BE ABLE TO FALL OFF IN THE EVENING. OTHERWISE...
HIGH TEMPERATURES FOR TUESDAY AND WEDNESDAY WILL LIKELY BE NEAR OR
JUST ABOVE FREEZING...WITH THE HIGHS IN THE LOW 40S POSSIBLE IN
SOUTH CENTRAL SD WHERE THE GREATEST POTENTIAL MIXING OF THE MILD LOW
LEVEL TEMPERATURES COULD OCCUR.
LATEST MODEL RUNS SHOWING A LITTLE BETTER AGREEMENT FOR THE SYSTEM
ON WEDNESDAY NIGHT AND THURSDAY...BUT DIVERGE A BIT LEADING INTO
NEXT WEEKEND. ALSO OF NOTE ARE SOME PRETTY BIG CHANGES FROM EARLIER
MODELS RUNS. LATEST 12Z RUNS OF GFS AND ECMWF ARE MUCH SLOWER AND
FURTHER SOUTH WITH THE CLOSED LOW SYSTEM...RESULTING IN LITTLE TO NO
IMPACT ACROSS OUR FORECAST AREA. WENT AHEAD AND REMOVED MENTION OF
POPS FOR WEDNESDAY GIVEN THE SLOWER TIMING. DECIDED TO KEEP MENTION
OF LOW CHANCE POPS MAINLY IN NORTHWEST IOWA ON THURSDAY GIVEN THE
RECENT INCONSISTENCIES BETWEEN MODEL RUNS...BUT DID TRIM BACK
COVERAGE AND QUITE A BIT FROM THE ALL BLEND...WHICH WAS BIASED FROM
THE 00Z ECMWF RUN. TEMPERATURES REMAIN QUITE MILD INTO THURSDAY...
BRINGING THE QUESTION OF PRECIPITATION TYPE IF THIS SYSTEM DOES
GRAZE OUR SOUTHEAST CWA. GIVEN WHAT LOOKS LIKE VERY MILD LOW/MID
LEVELS...PRECIPITATION TYPE MAY BECOME A CONCERN EARLY THURSDAY...
BUT WITH MANY FACTORS UP IN THE AIR...WILL KEEP IT SIMPLE WITH A
RAIN AND SNOW MIX.
THE NEXT AREA OF UNCERTAINTY IS REGARDING A STORM SYSTEM AROUND THE
SATURDAY TIME FRAME. MODELS CONTINUE TO FLIP FLOP WITH
SOLUTIONS...RESULTING IN LARGE TEMPERATURE AND POP DIFFERENCES. NOT
A WHOLE LOT OF CONFIDENCE...ESPECIALLY WITH THE VERY EXTREME GFS
SOLUTION. IT DOES LOOK LIKE A BIT OF A COOL DOWN FRIDAY AND SATURDAY
COMPARED TO EARLIER IN THE WEEK...BUT NOTHING TOO EXTREME. DID NOT
ALTER MUCH FROM THE ALLBLEND.
&&
.AVIATION.../FOR THE 18Z TAF ISSUANCE/
STRATUS FIELD BEHIND ADVANCING COLD FRONT WILL SPREAD INTO KHON IN
THE FIRST HOUR OF NEW TAFS...AND WILL SPREAD THROUGH KFSD AND KSUX
SEQUENTIALLY DURING THE 21Z-23Z WINDOW. CEILINGS ARE EXPECTED TO
MAINLY BE MVFR...BUT VERY LATE AFTERNOON AND EARLY EVENING...SOME
OF THE IFR CEILINGS ALONG WITH MVFR VISIBILITIES IN FLURRIES SHOULD
WANDER SOUTHWARD INTO THE AREA. SIDED WITH THE MORE PESSIMISTIC
DURATION TO CEILINGS IN THE RAP MODEL SOLUTION. WINDS GUSTS WILL
EXCEED 25 KNOTS DURING THE AFTERNOON TO MID EVENING HOURS FOR AREAS
FROM INTERSTATE 29 WESTWARD...AND LATE AFTERNOON AND EVENING FOR
AREAS EAST. /CHAPMAN
&&
.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
1149 AM CST SAT JAN 5 2013
.DISCUSSION.../ISSUED AT 946 AM CST/
WARM FRONT/TROUGH PUSHING TOWARD JAMES VALLEY THIS MORNING...BUT
COLD FRONT CLOSE ON ITS HEELS PUSHING THROUGH NORTHWEST THIRD OF
THE STATE ALREADY BY 15Z. FOR THE MOST PART...GOING FORECAST IS ON
TRACK AND NO SIGNIFICANT CHANGES ARE NEEDED. HAVE ADJUSTED SOME OF
THE HOURLY TEMPERATURE TRENDS TO FIT THE DIFFERENTIAL WARMTH WITH
ELEVATION AHEAD OF WIND SHIFT EARLY THIS MORNING. EXPECT AREAS TO
MIX OUT WITH SHIFT IN WINDS TO WEST AND NORTHWEST...BUT INCREASING
STRATUS AND COLD ADVECTION SHOULD LEAD TO FALLING TEMPS BEHIND THE
BOUNDARY THIS AFTERNOON...AS WELL AS A FEW FLURRIES. DID SLOW UP THE
ADVANCE OF CLOUDS/FLURRIES TO THE SOUTHEAST JUST A BIT. /CHAPMAN
&&
.AVIATION.../FOR THE 18Z TAF ISSUANCE/
STRATUS FIELD BEHIND ADVANCING COLD FRONT WILL SPREAD INTO KHON IN
THE FIRST HOUR OF NEW TAFS...AND WILL SPREAD THROUGH KFSD AND KSUX
SEQUENTIALLY DURING THE 21Z-23Z WINDOW. CEILINGS ARE EXPECTED TO
MAINLY BE MVFR...BUT VERY LATE AFTERNOON AND EARLY EVENING...SOME
OF THE IFR CEILINGS ALONG WITH MVFR VISIBILITIES IN FLURRIES SHOULD
WANDER SOUTHWARD INTO THE AREA. SIDED WITH THE MORE PESSIMISTIC
DURATION TO CEILINGS IN THE RAP MODEL SOLUTION. WINDS GUSTS WILL
EXCEED 25 KNOTS DURING THE AFTERNOON TO MID EVENING HOURS FOR AREAS
FROM INTERSTATE 29 WESTWARD...AND LATE AFTERNOON AND EVENING FOR
AREAS EAST. /CHAPMAN
&&
.PREV DISCUSSION.../ISSUED AT 328 AM CST/
SHORT WAVE WILL DROP SOUTHEAST ACROSS CWA TODAY AND WILL PUSH
COLD FRONT SOUTHEAST ACROSS CWA. WILL MIX OUT WELL BEHIND THIS FRONT
WITH THE COLD AIR ADVECTION...BUT STILL WILL SEE HIGHS NEAR NORMAL.
THIS WAVE WILL BRING A CHANCE OF FLURRIES TO NORTHEAST HALF OF CWA
THIS AFTERNOON AS IT SLIDES SOUTHEAST INTO MINNESOTA. WILL ALSO SEE
GUSTY WIND OF 20 TO 30 MPH BEHIND FRONT AND MAT PRODUCE SOME BLOWING
SNOW ACROSS NORTHEAST CWA. HOWEVER...SNOW COVER NOT THAT DEEP AND
WITH DITCHES NOT FULL OF SNOW...DO NOT SEE MUCH OF A PROBLEM WITH
BLOWING SNOW.
SURFACE RIDGE WILL PUSH EAST ACROSS CWA TONIGHT...AND WITH CLEARING
SKIES AND DECREASING WINDS...WILL SEE LOWS DIP INTO THE SINGLE
DIGITS.
WARM AIR WILL BEGIN TO RETURN TO CWA ON SUNDAY AS RIDGE AXIS ALOFT
SHIFTS TO THE EAST. THIS WILL ALLOW THE BEST WARMING ACROSS THE WEST
ON SUNDAY WITH HIGHS BACK INTO THE 30S ACROSS THE SOUTHWEST. SOUTH
TO SOUTHWEST WINDS SUNDAY NIGHT WILL HELP HOLD TEMPERATURES UP
ACROSS THE CWA WITH WINDS GUSTING TO 30 TO 35 MPH ACROSS THE BUFFALO
RIDGE.
THE MILD WEATHER WILL CONTINUE MONDAY THROUGH WEDNESDAY WITH A MILD
WEST TO SOUTHWEST LOW LEVEL FLOW. GFS APPEARS TO BE OVER DOING WAVE
ON TUESDAY AND PREFER THE MORE TAME EC/GEM SOLUTION. EITHER
WAY...ABOVE NORMAL TEMPERATURES EXPECTED. HOWEVER...SNOW
COVER...ESPECIALLY NORTH OF INTERSTATE 90 WILL HOLD TEMPERATURES
DOWN A BIT...BUT SHOULD STILL MIX OUT INTO LOWER 30S...WITH LOWER
40S ACROSS SOUTHWEST CWA BY TUESDAY AND WEDNESDAY. SNOW COVER ACROSS
NEBRASKA WILL ALSO HAVE SOME IMPACT ACROSS SOUTHWEST CWA. OTHERWISE
IF THERE WAS NO SNOW COVER THERE...COULD HIT THE LOWER 50S.
MODELS DIVERGE A BIT FOR LATE WEDNESDAY NIGHT AND THURSDAY WITH WAVE
LIFTING NORTHEAST OUT OF SOUTHERN PLAINS. GFS MUCH FASTER AND
FURTHER SOUTHEAST...WHILE ECMWF AND GEM SLOWER AND FURTHER NORTH.
GFS HAS NOT HANDLED SOUTHERN SYSTEMS VERY WELL THIS WINTER AND
PREFER MORE STABLE ECMWF. STILL...THIS SYSTEM APPEARS THAT IT WILL
GRAZE THE SOUTHEAST CWA EVEN WITH ITS FURTHEST NORTH SOLUTION. WILL
BE A RELATIVELY WARM SYSTEM AND COULD SEE A MIX OF LIGHT FREEZING
RAIN OR SNOW ACROSS THE FAR SOUTHEAST LATE WEDNESDAY NIGHT. WILL
KEEP THE 20% TO 30% POPS GOING ACROSS THE SOUTHEAST ON THURSDAY.
COLDER AIR WILL FILTER BACK INTO CWA FOR FRIDAY BEHIND THIS SYSTEM.
MODELS ALL OVER THE PLACE FOR NEXT WEEKEND...WITH THE TYPICAL GFS
STORM CREATING SOLUTIONS AFTER DAY 7. ECMWF MUCH WEAKER AND USUALLY
MORE CORRECT.
&&
.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
946 AM CST SAT JAN 5 2013
.DISCUSSION.../ISSUED AT 946 AM CST/
WARM FRONT/TROUGH PUSHING TOWARD JAMES VALLEY THIS MORNING...BUT
COLD FRONT CLOSE ON ITS HEELS PUSHING THROUGH NORTHWEST THIRD OF
THE STATE ALREADY BY 15Z. FOR THE MOST PART...GOING FORECAST IS ON
TRACK AND NO SIGNIFICANT CHANGES ARE NEEDED. HAVE ADJUSTED SOME OF
THE HOURLY TEMPERATURE TRENDS TO FIT THE DIFFERENTIAL WARMTH WITH
ELEVATION AHEAD OF WIND SHIFT EARLY THIS MORNING. EXPECT AREAS TO
MIX OUT WITH SHIFT IN WINDS TO WEST AND NORTHWEST...BUT INCREASING
STRATUS AND COLD ADVECTION SHOULD LEAD TO FALLING TEMPS BEHIND THE
BOUNDARY THIS AFTERNOON...AS WELL AS A FEW FLURRIES. DID SLOW UP THE
ADVANCE OF CLOUDS/FLURRIES TO THE SOUTHEAST JUST A BIT. /CHAPMAN
&&
.AVIATION.../FOR THE 12Z TAF ISSUANCE/
VFR CONDITIONS EXPECTED TO CONTINUE THROUGH THE MORNING HOURS. A
COLD FRONT WILL PUSH THROUGH THE AREA THIS AFTERNOON. WINDS WILL
TURN BLUSTERY BEHIND THE FRONT WITH GUSTS OF 20 TO 30 KTS LIKELY.
AREA OF DEVELOPING MVFR AND IFR STRATUS OVER NORTH DAKOTA WILL
EXPAND AND HEAD SOUTH INTO OUR CWA THIS AFTERNOON. SPED UP THE
TIMING SOME IN THE TAFS BASED ON THE QUICKER RAP MODEL. THIS BRINGS
MVFR CIGS INTO KHON SHORTLY AFTER NOON...AND INTO KFSD AND KSUX BY
MID AFTERNOON. CURRENTLY THINKING MOST AREAS STAY IN THE 1-2KFT
RANGE...ALTHOUGH WILL HAVE TO MONITOR...AS SOME IFR CIGS ARE
POSSIBLE...ESPECIALLY TOWARDS EVENING. LOOKS LIKE WE SHOULD SEE
SCATTERED FLURRIES WITH THIS STRATUS...BUT VISIBILITY REDUCTIONS NOT
EXPECTED. STRATUS WILL CLEAR OUT TONIGHT FROM NORTHWEST TO
SOUTHEAST. SOME UNCERTAINTY ON WHEN THIS HAPPENS...BUT CURRENTLY
THINKING ALL TAF SITES ARE VFR BY AROUND OR SHORTLY AFTER MIDNIGHT.
VFR CONDITIONS WILL THEN CONTINUE THROUGH THE REMAINDER OF THE NIGHT
WITH DISSIPATING WINDS. /CHENARD
&&
.PREV DISCUSSION.../ISSUED AT 328 AM CST/
SHORT WAVE WILL DROP SOUTHEAST ACROSS CWA TODAY AND WILL PUSH
COLD FRONT SOUTHEAST ACROSS CWA. WILL MIX OUT WELL BEHIND THIS FRONT
WITH THE COLD AIR ADVECTION...BUT STILL WILL SEE HIGHS NEAR NORMAL.
THIS WAVE WILL BRING A CHANCE OF FLURRIES TO NORTHEAST HALF OF CWA
THIS AFTERNOON AS IT SLIDES SOUTHEAST INTO MINNESOTA. WILL ALSO SEE
GUSTY WIND OF 20 TO 30 MPH BEHIND FRONT AND MAT PRODUCE SOME BLOWING
SNOW ACROSS NORTHEAST CWA. HOWEVER...SNOW COVER NOT THAT DEEP AND
WITH DITCHES NOT FULL OF SNOW...DO NOT SEE MUCH OF A PROBLEM WITH
BLOWING SNOW.
SURFACE RIDGE WILL PUSH EAST ACROSS CWA TONIGHT...AND WITH CLEARING
SKIES AND DECREASING WINDS...WILL SEE LOWS DIP INTO THE SINGLE
DIGITS.
WARM AIR WILL BEGIN TO RETURN TO CWA ON SUNDAY AS RIDGE AXIS ALOFT
SHIFTS TO THE EAST. THIS WILL ALLOW THE BEST WARMING ACROSS THE WEST
ON SUNDAY WITH HIGHS BACK INTO THE 30S ACROSS THE SOUTHWEST. SOUTH
TO SOUTHWEST WINDS SUNDAY NIGHT WILL HELP HOLD TEMPERATURES UP
ACROSS THE CWA WITH WINDS GUSTING TO 30 TO 35 MPH ACROSS THE BUFFALO
RIDGE.
THE MILD WEATHER WILL CONTINUE MONDAY THROUGH WEDNESDAY WITH A MILD
WEST TO SOUTHWEST LOW LEVEL FLOW. GFS APPEARS TO BE OVER DOING WAVE
ON TUESDAY AND PREFER THE MORE TAME EC/GEM SOLUTION. EITHER
WAY...ABOVE NORMAL TEMPERATURES EXPECTED. HOWEVER...SNOW
COVER...ESPECIALLY NORTH OF INTERSTATE 90 WILL HOLD TEMPERATURES
DOWN A BIT...BUT SHOULD STILL MIX OUT INTO LOWER 30S...WITH LOWER
40S ACROSS SOUTHWEST CWA BY TUESDAY AND WEDNESDAY. SNOW COVER ACROSS
NEBRASKA WILL ALSO HAVE SOME IMPACT ACROSS SOUTHWEST CWA. OTHERWISE
IF THERE WAS NO SNOW COVER THERE...COULD HIT THE LOWER 50S.
MODELS DIVERGE A BIT FOR LATE WEDNESDAY NIGHT AND THURSDAY WITH WAVE
LIFTING NORTHEAST OUT OF SOUTHERN PLAINS. GFS MUCH FASTER AND
FURTHER SOUTHEAST...WHILE ECMWF AND GEM SLOWER AND FURTHER NORTH.
GFS HAS NOT HANDLED SOUTHERN SYSTEMS VERY WELL THIS WINTER AND
PREFER MORE STABLE ECMWF. STILL...THIS SYSTEM APPEARS THAT IT WILL
GRAZE THE SOUTHEAST CWA EVEN WITH ITS FURTHEST NORTH SOLUTION. WILL
BE A RELATIVELY WARM SYSTEM AND COULD SEE A MIX OF LIGHT FREEZING
RAIN OR SNOW ACROSS THE FAR SOUTHEAST LATE WEDNESDAY NIGHT. WILL
KEEP THE 20% TO 30% POPS GOING ACROSS THE SOUTHEAST ON THURSDAY.
COLDER AIR WILL FILTER BACK INTO CWA FOR FRIDAY BEHIND THIS SYSTEM.
MODELS ALL OVER THE PLACE FOR NEXT WEEKEND...WITH THE TYPICAL GFS
STORM CREATING SOLUTIONS AFTER DAY 7. ECMWF MUCH WEAKER AND USUALLY
MORE CORRECT.
&&
.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
534 AM CST SAT JAN 5 2013
.DISCUSSION.../ISSUED AT 328 AM CST/
SHORT WAVE WILL DROP SOUTHEAST ACROSS CWA TODAY AND WILL PUSH
COLD FRONT SOUTHEAST ACROSS CWA. WILL MIX OUT WELL BEHIND THIS FRONT
WITH THE COLD AIR ADVECTION...BUT STILL WILL SEE HIGHS NEAR NORMAL.
THIS WAVE WILL BRING A CHANCE OF FLURRIES TO NORTHEAST HALF OF CWA
THIS AFTERNOON AS IT SLIDES SOUTHEAST INTO MINNESOTA. WILL ALSO SEE
GUSTY WIND OF 20 TO 30 MPH BEHIND FRONT AND MAT PRODUCE SOME BLOWING
SNOW ACROSS NORTHEAST CWA. HOWEVER...SNOW COVER NOT THAT DEEP AND
WITH DITCHES NOT FULL OF SNOW...DO NOT SEE MUCH OF A PROBLEM WITH
BLOWING SNOW.
SURFACE RIDGE WILL PUSH EAST ACROSS CWA TONIGHT...AND WITH CLEARING
SKIES AND DECREASING WINDS...WILL SEE LOWS DIP INTO THE SINGLE
DIGITS.
WARM AIR WILL BEGIN TO RETURN TO CWA ON SUNDAY AS RIDGE AXIS ALOFT
SHIFTS TO THE EAST. THIS WILL ALLOW THE BEST WARMING ACROSS THE WEST
ON SUNDAY WITH HIGHS BACK INTO THE 30S ACROSS THE SOUTHWEST. SOUTH
TO SOUTHWEST WINDS SUNDAY NIGHT WILL HELP HOLD TEMPERATURES UP
ACROSS THE CWA WITH WINDS GUSTING TO 30 TO 35 MPH ACROSS THE BUFFALO
RIDGE.
THE MILD WEATHER WILL CONTINUE MONDAY THROUGH WEDNESDAY WITH A MILD
WEST TO SOUTHWEST LOW LEVEL FLOW. GFS APPEARS TO BE OVER DOING WAVE
ON TUESDAY AND PREFER THE MORE TAME EC/GEM SOLUTION. EITHER
WAY...ABOVE NORMAL TEMPERATURES EXPECTED. HOWEVER...SNOW
COVER...ESPECIALLY NORTH OF INTERSTATE 90 WILL HOLD TEMPERATURES
DOWN A BIT...BUT SHOULD STILL MIX OUT INTO LOWER 30S...WITH LOWER
40S ACROSS SOUTHWEST CWA BY TUESDAY AND WEDNESDAY. SNOW COVER ACROSS
NEBRASKA WILL ALSO HAVE SOME IMPACT ACROSS SOUTHWEST CWA. OTHERWISE
IF THERE WAS NO SNOW COVER THERE...COULD HIT THE LOWER 50S.
MODELS DIVERGE A BIT FOR LATE WEDNESDAY NIGHT AND THURSDAY WITH WAVE
LIFTING NORTHEAST OUT OF SOUTHERN PLAINS. GFS MUCH FASTER AND
FURTHER SOUTHEAST...WHILE ECMWF AND GEM SLOWER AND FURTHER NORTH.
GFS HAS NOT HANDLED SOUTHERN SYSTEMS VERY WELL THIS WINTER AND
PREFER MORE STABLE ECMWF. STILL...THIS SYSTEM APPEARS THAT IT WILL
GRAZE THE SOUTHEAST CWA EVEN WITH ITS FURTHEST NORTH SOLUTION. WILL
BE A RELATIVELY WARM SYSTEM AND COULD SEE A MIX OF LIGHT FREEZING
RAIN OR SNOW ACROSS THE FAR SOUTHEAST LATE WEDNESDAY NIGHT. WILL
KEEP THE 20% TO 30% POPS GOING ACROSS THE SOUTHEAST ON THURSDAY.
COLDER AIR WILL FILTER BACK INTO CWA FOR FRIDAY BEHIND THIS SYSTEM.
MODELS ALL OVER THE PLACE FOR NEXT WEEKEND...WITH THE TYPICAL GFS
STORM CREATING SOLUTIONS AFTER DAY 7. ECMWF MUCH WEAKER AND USUALLY
MORE CORRECT.
&&
.AVIATION.../FOR THE 12Z TAF ISSUANCE/
VFR CONDITIONS EXPECTED TO CONTINUE THROUGH THE MORNING HOURS. A
COLD FRONT WILL PUSH THROUGH THE AREA THIS AFTERNOON. WINDS WILL
TURN BLUSTERY BEHIND THE FRONT WITH GUSTS OF 20 TO 30 KTS LIKELY.
AREA OF DEVELOPING MVFR AND IFR STRATUS OVER NORTH DAKOTA WILL
EXPAND AND HEAD SOUTH INTO OUR CWA THIS AFTERNOON. SPED UP THE
TIMING SOME IN THE TAFS BASED ON THE QUICKER RAP MODEL. THIS BRINGS
MVFR CIGS INTO KHON SHORTLY AFTER NOON...AND INTO KFSD AND KSUX BY
MID AFTERNOON. CURRENTLY THINKING MOST AREAS STAY IN THE 1-2KFT
RANGE...ALTHOUGH WILL HAVE TO MONITOR...AS SOME IFR CIGS ARE
POSSIBLE...ESPECIALLY TOWARDS EVENING. LOOKS LIKE WE SHOULD SEE
SCATTERED FLURRIES WITH THIS STRATUS...BUT VISIBILITY REDUCTIONS NOT
EXPECTED. STRATUS WILL CLEAR OUT TONIGHT FROM NORTHWEST TO
SOUTHEAST. SOME UNCERTAINTY ON WHEN THIS HAPPENS...BUT CURRENTLY
THINKING ALL TAF SITES ARE VFR BY AROUND OR SHORTLY AFTER MIDNIGHT.
VFR CONDITIONS WILL THEN CONTINUE THROUGH THE REMAINDER OF THE NIGHT
WITH DISSIPATING WINDS. /CHENARD
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1151 PM CST FRI JAN 4 2013
.DISCUSSION...
UPDATED AVIATION DISCUSSION.
&&
.AVIATION...
CONTINUED WITH VFR FOR MOST OF THE TAF PERIOD DESPITE PERIODS OF
MAINLY LIGHT SHOWERS. BEST CHANCE FOR MEASURABLE RAIN...ALBEIT
LIGHT WILL BE OVERNIGHT FOR NORTHERN TAF SITES...AND TOMORROW FOR
SOUTHERN TAF SITES AS JET STREAK AND ASSOCIATED LIFT MOVE ACROSS
THE AREA...ALTHOUGH THERE COULD BE A LIGHT SHOWER ALMOST ANY TIME.
46
&&
.MARINE...EXTENDED SMALL CRAFT ADVISORY THROUGH TOMORROW AS NOW
APPEARS AFTER A SLIGHT DECREASE IN SPEEDS OVERNIGHT...WINDS SHOULD
PICK UP AGAIN LATE TONIGHT AND SATURDAY AS GULF LOW DEEPENS.
SHOULD BE MAINLY THE 20 TO 60 NM ZONES THAT SHOULD SEE THE HIGHER
WINDS. 46
&&
.PREV DISCUSSION... /ISSUED 915 PM CST FRI JAN 4 2013/
UPDATE...
SCATTERED OFFSHORE SHOWERS BECOMING BETTER ORGANIZED JUST OFF THE
COASTLINE...WITH VERY LIGHT SHOWER ACTIVITY JUST TO THE WEST OF
OUR NORTHWESTERN CWA. WEAK DIVERGENCE RIDING PARALLEL THE COAST
(PER REGION FALLING IN THE RR 25H QUAD) AND THE OFFSHORE STATIONARY
BOUNDARY WILL BE ENOUGH TO KEEP PERIODIC LIGHT SHOWERS IN PLAY
THROUGH SATURDAY AFTERNOON. THE NEAR WEST-TO-EAST ELONGATED UPPER
TOUGH AXIS WILL EVENTUALLY PASS EAST OF THE REGION LATE TOMORROW...
BRINGING THE INTERIOR SHRA TO AN END GOING INTO SATURDAY EVENING.
A WEAK LOWER LEVEL BOUNDARY WILL PASS INTO CENTRAL TEXAS...BUT
WITHOUT A SIGNIFICANT NORTHWESTERN HIGH TO BACK IT...THIS BOUNDARY
WILL STRETCH OUT AND SURFACE WINDS WILL REMAIN NORTHEAST IN NATURE.
MODERATE TO STRONG NORTH-EAST MARITIME WINDS THROUGH THE WEEKEND
AS THE OFFSHORE GRADIENT BETWEEN INLAND HIGH PRESSURE AND THE OFFSHORE
STATIONARY BOUNDARY STAYS TAUNT.
ALONG WITH PASSING SHOWERS...A COLD AND CLOUDY SATURDAY. ISENTROPIC
UPGLIDE IN PLACE AS MID-LEVEL SOUTHWESTERLIES ABOVE THESE NEAR SURFACE
(NORTH)EASTERLIES WILL KEEP SKIES MOSTLY OVERCAST AND THE MAJORITY
OF THE DAY IN THE 40S...MERCURY ONLY BRIEFLY TOUCHING THE LOWER 50S
FOR A LATE AFTERNOON HOUR OR TWO. 31
PREV DISCUSSION... /ISSUED 607 PM CST FRI JAN 4 2013/
DISCUSSION...
UPDATED AVIATION DISCUSSION.
AVIATION...
LATEST OBS AND RADAR SHOWING SOME LIGHT SHOWERS AROUND NORTHERN
TAF SITES WITH VFR 5000 TO 6000 FOOT DECK EVERYWHERE. SOME LOWER
CLOUDS INDICATED OFF TO THE WEST. OVERALL EXPECTING MOSTLY VFR
CONDITIONS AT TAF SITES...WITH A PERIOD OF MVFR POSSIBLE AT LEAST
NORTHERN TAF SITES OVERNIGHT AS BAND OF LIGHT RAIN SHIFTS EAST.
ANOTHER BAND OF LIGHT RAIN POSSIBLE ON SATURDAY FARTHER SOUTH AS
JET STREAK PIVOTS AROUND UPPER LOW...PLACING SE TEXAS IN RIGHT
REAR QUADRANT. IN ANY CASE NOT EXPECTING MUCH IN THE WAY OF
VISIBILITY RESTRICTIONS...JUST A SHORT PERIOD OF MVFR CIGS WITH
THESE BANDS OF RAIN AS THEY PIVOT THROUGH. 46
PREV DISCUSSION... /ISSUED 407 PM CST FRI JAN 4 2013/
DISCUSSION...
NOT TOO MANY CHANGES FOR THE SHORT TERM PART OF THE FCST WITH THIS
PACKAGE AS THE COLD/CLOUDY/WET PATTERN REMAINS IN PLACE OVER SE TX
THROUGH THE EARLY PART OF THIS WEEKEND. STRONG SOUTHERN STREAM JET
HELPING TO BRING A SERIES OF SHORTWAVES ACROSS THE REGION WITH THE
NEXT ONE LOOKING LIKE IT IS GOING TO MOVE THROUGH OUR CWA LATE TO-
NIGHT/SAT (PER LATEST THE WV LOOPS).
THE PERSISTENT BKN/OVC MID/HIGH CLOUD DECK SHOULD BREAK BY SUN AS
THE MAIN UPPER TROF AXIS SHIFTS EAST AND THE BRIEF RIDGING DEVEL-
OPS IN ITS WAKE. BUT AS IT HAS BEEN THE TREND OF LATE...THIS VERY
PROGRESSIVE UPPER PATTERN WILL BE BRINGING THE NEXT SYSTEM TOWARD
THE STATE QUICKLY. WHILE MODELS HAVE BEEN CONSISTENT WE ARE STILL
SEEING MARKED DIFFERENCES IN REGARD TO THE TIMING FOR THE PASSAGE
OF THE NEXT CLOSED UPPER LOW STORM SYSTEM. ECMWF RETAINING A LONE
WOLF ROLE WITH ITS SLOWER TIMING...WITH THE GFS APPEARING TO HAVE
SPED UP WITH THE 12Z RUNS. DID MAKE SOME CHANGES TO POPS FOR THIS
TUES/TUES NIGHT TIMEFRAME ACCOUNT FOR THE UNCERTAINTY. REGARDLESS
WE COULD BE DEALING WITH STRONG/SEVERE STORMS WITH THE PASSAGE OF
THIS SYSTEM (NO MATTER WHICH DAY IT ARRIVES). PROGS OF STRONG LOW
TO MID LEVEL INFLOW (40-50KTS)...FAVOURABLE POSITION OF THE UPPER
JET (LFQ) AND THE PASSAGE OF THE COLD FRONT ITSELF ALL SEEM TO BE
POINTING IN THAT DIRECTION. BEAR WATCH IN PLACE. 41
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 45 40 51 38 57 / 40 30 20 10 10
HOUSTON (IAH) 50 40 52 39 60 / 20 30 40 10 10
GALVESTON (GLS) 48 45 54 46 59 / 20 30 40 20 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION THROUGH SATURDAY AFTERNOON
FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE
MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND
TO FREEPORT OUT 20 NM.
SMALL CRAFT ADVISORY UNTIL 5 PM CST SATURDAY FOR THE FOLLOWING
ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL
20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO
60 NM.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
201 PM CST SAT JAN 5 2013
.SHORT TERM...THROUGH MONDAY NIGHT
201 PM CST SAT JAN 5 2013
MAIN FORECAST CONCERN IS WITH THE PRECIPITATION CHANCES TONIGHT.
SURFACE ANALYSIS EARLY THIS AFTERNOON SHOWS AN AREA OF LOW
PRESSURE OVER NORTHEAST MINNESOTA NEAR KDLH WITH A COLD FRONT
EXTENDING SOUTHWEST INTO KANSAS.
WATER VAPOR SATELLITE SHOWING THREE SYSTEMS THAT WILL IMPACT THE
REGION TONIGHT. UPPER LEVEL LOW AND SHORT WAVE TROUGH MOVING
ACROSS NORTHERN MISSOURI WILL CONTINUE TO MOVE OFF TO THE
EAST/NORTHEAST TONIGHT TOWARD LAKE ERIE. AS IT DOES...A SHORT WAVE
TROUGH OVER SOUTH DAKOTA WILL MOVE SOUTHEAST ACROSS IOWA INTO THE
OHIO RIVER VALLEY. THIS WAVE WILL RAPIDLY PUSH THE SURFACE LOW AND
COLD FRONT ACROSS THE REGION THROUGH THE REMAINDER OF THE
AFTERNOON AND THIS EVENING. THE THIRD SHORT WAVE TROUGH IS MOVING
INTO NORTH DAKOTA FROM MANITOBA AND IS EXPECTED TO MOVE RIGHT
TOWARD THE AREA THROUGH THE NIGHT. THE FIRST SYSTEM IS EXPECTED TO
PASS BY FAR ENOUGH TO THE SOUTH TO NOT HAVE AN IMPACT ON THE AREA.
HOWEVER...THE SECOND SHORT WAVE TROUGH AND SURFACE SYSTEM MAY HAVE
ENOUGH GOING TO POSSIBLY PRODUCE SOME LIGHT FREEZING DRIZZLE ALONG
AND AHEAD OF THE COLD FRONT. THE 05.12Z NAM SHOWS SOME WEAK
OMEGA...ON THE ORDER OF ABOUT 1 UBAR/S...IN THE 0-2 KM LAYER WHERE
SOME WARM AIR ADVECTION WILL BE OCCURRING IN THE SOUTHWEST FLOW
AHEAD OF THE COLD FRONT. THE NAM AND 05.16Z RAP BUFKIT SOUNDINGS
SHOW THE LOW LEVELS SATURATING UP TO BETWEEN 2 AND 3 KM BEFORE THE
FRONT COMES THROUGH. HOWEVER...SOMEWHAT CONCERNED THAT THE BEST
LIFT MAY BE NEAR THE TOP OR JUST ABOVE THE SATURATED LAYER AND
THUS MAY NOT BE ABLE TO PRODUCE A WHOLE LOT OF DRIZZLE. STILL
ENOUGH OF A CONCERN TO KEEP THE LOW CHANCES FOR THE FREEZING
DRIZZLE AND NO CHANGES ARE PLANNED TO THE CURRENT FORECAST.
THE THIRD SHORT WAVE TROUGH IS PRODUCING SOME REPORTS OF LIGHT
SNOW ACROSS NORTH DAKOTA AND SOUTHERN MANITOBA WITH MVFR
VISIBILITIES. HOWEVER...THESE REPORTS ARE VERY SPORADIC WITH NOT
MUCH AREAL COVERAGE. THE FORECAST SOUNDINGS DO NOT SHOW THIS WAVE
PRODUCING MUCH OMEGA TONIGHT AS IT APPROACHES BUT IT SHOULD
PRODUCE UP TO 12 PVU/S OF VORTICITY ADVECTION IN THE 500-300 MB
LAYER. SOMEWHAT CONCERNED THAT THE MODELS MAY BE UNDERDONE WITH
THE AMOUNT OF LIFT THIS WAVE WILL PRODUCE AND THAT IT COULD END UP
PRODUCING A PERIOD OF VERY LIGHT SNOW BUT WILL MAINTAIN THE
FLURRIES AS THERE IS SOME QUESTION AS TO WHETHER THE MID LEVELS
WILL SATURATE ENOUGH TO ALLOW FOR ANYTHING MORE THAN FLURRIES.
AFTER THIS WAVE MOVES BY...QUIET AND WARMER WEATHER WILL SET UP
OVER THE REGION. THE SURFACE HIGH THAT WILL BE OVER THE REGION
SUNDAY WILL MOVE OFF TO THE EAST SUNDAY NIGHT AS A SYSTEM ROLLS
ACROSS SOUTHERN CANADA. THE PRECIPITATION FROM THIS SYSTEM WILL
STAY WELL TO THE NORTH BUT IT WILL HELP DRAW WARMER AIR IN WITH
HIGHS MONDAY EXPECTED TO TOP OUT IN THE LOWER 30S ACROSS THE
ENTIRE AREA.
.LONG TERM...TUESDAY THROUGH SATURDAY
201 PM CST SAT JAN 5 2013
MEDIUM RANGE MODELS HAVE STARTED TO COME INTO BETTER AGREEMENT
WITH THE SYSTEM EXPECTED TO IMPACT THE GREAT LAKES FOR THE LATTER
HALF OF THE WEEK. THE 05.00Z ECMWF HAS REMAINED CONSISTENT WITH
ITS PREVIOUS RUNS ON THE TRACK OF THE SYSTEM WHILE THE 05.12Z GFS
HAS SHIFTED CONSIDERABLY TOWARD THE ECMWF SOLUTION. THE MODELS ARE
NOW VERY SIMILAR IN TIMING BUT THE GFS STILL DOES NOT BRING THE
SYSTEM AS FAR NORTH AS THE ECMWF. BY 11.00Z /FRIDAY EVENING/ THE
ECMWF PLACES THE UPPER LEVEL LOW NEAR THE WISCONSIN-ILLINOIS
BORDER BETWEEN KDBQ AND KRST WHILE THE GFS IS FARTHER SOUTH NEAR
KSTL. THE AGREEMENT THAT WAS IN PLACE HAS BEEN THROWN OUT THE
WINDOW BY THE 05.12Z ECMWF HAS IT HAS COME IN SLOWER AND FARTHER
SOUTH AND IS NOT SIMILAR WITH ITS TRACK TO THE GFS. WITH THE
DISPARITY BETWEEN THE MODELS...THE ONLY CHANGE MADE TO THE MODEL
CONSENSUS GRIDS WAS TO WEDNESDAY NIGHT. WITH THE ECMWF NOW BEING
SLOWER...IT SUGGESTS THE PRECIPITATION WILL NOT MOVE IN UNTIL
THURSDAY...SO WILL NOW GO WITH A DRY WEDNESDAY NIGHT. THE
PRECIPITATION FROM THIS SYSTEM SHOULD START TO MOVE OUT THURSDAY
NIGHT OR FRIDAY BUT WILL QUICKLY BE FOLLOWED BY THE NEXT SYSTEM.
THE MODELS MAINTAIN A SOUTHWEST FLOW ALOFT BEHIND THIS SYSTEM AND
QUICKLY EJECT OUT ANOTHER SYSTEM FROM THE SOUTHERN ROCKIES. THE
ECMWF IS QUICKER AND FARTHER NORTH THAN THE GFS IN THE UPPER
LEVELS...BUT THE SURFACE TRACKS LOOK TO BE SIMILAR GOING FROM NEAR
KMCI TOWARD KMKE EITHER SATURDAY OR SATURDAY NIGHT. THE ECMWF
SUGGESTS THE FIRST SYSTEM WILL BRING ENOUGH WARM AIR NORTH TO
PRODUCE PRIMARILY RAIN OR A RAIN/SNOW MIX. HOWEVER...THE
BAROCLINIC ZONE LEFT BEHIND MAY BE JUST TO THE SOUTHEAST GIVING
THE SECOND SYSTEM ENOUGH COLD AIR TO WORK WITH TO PRODUCE MAINLY
SNOW.
&&
.AVIATION...THROUGH 18Z SUNDAY
1111 AM CST SAT JAN 5 2013
LOW PRESSURE OVER SOUTH-CENTRAL MN LATE THIS MORNING WILL CONTINUE
TO MOVE EAST ACROSS THE AREA THIS AFTERNOON AND EXIT BY THIS
EVENING. WARMING/PARTIAL MELTING OF THE SNOW PACK TO OUR SOUTH AND
SOUTHWEST WINDS AHEAD OF THE LOW WILL DRAW INCREASINGLY MOIST AIR
INTO THE AREA FOR THE DEVELOPMENT OF STRATUS AFTER 21Z. LOOKING
FOR THIS STRATUS TO BECOME MORE ENTRENCHED OVER THE AREA GOING
INTO THIS EVENING AS COOLER NORTHWEST FLOW BEHIND THE LOW COOLS THE
LOWER BOUNDARY LAYER TO ITS SATURATION POINT. WILL ALSO BE ON THE
LOOKOUT FOR SOME PATCHY FREEZING DRIZZLE/SNOW GRAINS WITH WEAK LIFT
THROUGH THE STRATUS...BUT IT APPEARS THE MAJORITY OF THIS SHOULD
OCCUR EAST OF THE KRST/KLSE TAF SITES WHERE BETTER LOWER LEVEL
MOISTURE CONVERGENCE WILL BE REALIZED. WENT WITH MVFR STRATUS AT
KLSE THIS EVENING/OVERNIGHT WHILE IFR STRATUS WILL BE MORE LIKELY
AT KRST. LOOK FOR THE STRATUS TO CLEAR KRST BY 13Z AND KLSE AROUND
14Z AS DRIER AIR ADVECTS IN FROM THE NORTHERN PLAINS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
201 PM CST SAT JAN 5 2013
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION...DAS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1141 PM CST FRI JAN 4 2013
.SHORT TERM...TONIGHT THROUGH MONDAY
233 PM CST FRI JAN 4 2013
MAIN FORECAST CONCERNS ARE ON LIGHT PRECIPITATION CHANCES SATURDAY
AFTERNOON INTO SATURDAY NIGHT.
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING ALONG THE WEST COAST OF THE U.S. INTO BRITISH
COLUMBIA...AN UPPER LOW OVER NEW MEXICO...A SHORTWAVE TROUGH OVER
SOUTHERN ALBERTA...WEAK RIDGING OVER THE DAKOTAS AND DEEP TROUGHING
OVER EASTERN CANADA. THE FORECAST AREA WAS UNDER SUBSIDENCE ALOFT
BEING IN NORTHWEST FLOW AHEAD OF THE DAKOTAS RIDGING...RESULTING IN
CLEAR SKIES. IN FACT...MAINLY CLEAR SKIES ENCOMPASS MUCH OF THE
UPPER MIDWEST DUE TO PLENTY OF DRY AIR...SEEN ON 12Z SOUNDINGS FROM
BIS...OAX...MPX AND GRB. ONE THING OF INTEREST ON ALL OF THOSE
SOUNDINGS IS A STRONG AND NEARLY SATURATED INVERSION BETWEEN
925-950MB. AGAIN...DESPITE THE NEAR SATURATION...SKIES ARE STILL
CLEAR. SUNSHINE PLUS THE 925MB TEMPS STARTING OFF IN THE -3 TO -6C
RANGE AT 12Z FROM SOUNDING DATA AND DRY AIR HAS ALLOWED TEMPERATURES
TO CLIMB INTO THE MID 20S TO LOW 30S. TO THE NORTHWEST...HIGH
CLOUDS WERE SPREADING ACROSS SASKATCHEWAN AND NORTH DAKOTA AHEAD
OF THE SOUTHERN ALBERTA SHORTWAVE TROUGH. IN ADDITION...AN AREA OF
LOW PRESSURE HAS FORMED OVER SOUTHERN SASKATCHEWAN WITH A WARM
FRONT EXTENDING SOUTHEAST TO BISMARCK NORTH DAKOTA.
TONIGHT AND SATURDAY...MODELS ARE IN GOOD AGREEMENT DROPPING THE
SHORTWAVE TROUGH OVER ALBERTA THROUGH THE NORTHERN PLAINS AND INTO
NEBRASKA BY 00Z SUNDAY. THIS TROUGH HELPS TO EJECT AND SHEAR OUT THE
NEW MEXICO UPPER LOW...WHICH GETS LIFTED INTO SOUTHERN ILLINOIS AND
INDIANA. THE TRACKS OF THESE FEATURES SPLIT THE FORECAST AREA...
HOWEVER...THERE ARE STILL CONCERNS. THE MAIN ONE IS WITH LOW LEVEL
SATURATION. 925-900MB RH PROGS FROM THE 04.12Z NAM/GFS SHOW THAT AS
THE NEW MEXICO UPPER LOW LIFTS NORTHEAST...AN AREA OF LOW STRATUS
FORMS ACROSS MISSOURI SATURDAY MORNING...WHICH THEN SPREADS INTO
EASTERN IOWA AND SOUTHERN WISCONSIN DURING THE AFTERNOON. ABOVE
900MB...TROPOSPHERE IS STILL PRETTY DRY. ANALYSIS LOOKING AT THE
275-280K SURFACES SHOWS THAT MOISTURE GETS PULLED UP OUT OF THE GULF
OF MEXICO AS THE NEW MEXICO UPPER LOW LIFTS NORTHEAST. IN
ADDITION...THERE IS WEAK LIFT ON THESE SURFACES...WHICH GIVEN THAT
THE TEMPERATURE PROFILE HAS NO ICE...COULD LEAD TO FREEZING DRIZZLE
FORMATION. AS SUCH...HAVE RETAINED A MENTION OF FREEZING DRIZZLE
FROM 21-00Z...BUT RESTRICTED IT TO THE SOUTHEAST 1/3 OF THE AREA TO
CORRELATE WITH THE LIFT ON THE 275-280K SURFACES. ELSEWHERE...DRY
CONDITIONS WILL PREVAIL WITH PERHAPS LITTLE IN THE WAY OF CLOUD
COVER UNTIL LATER SATURDAY. WITH CLEAR SKIES AND DRY AIR TONIGHT...
ALONG WITH LIGHT WINDS IN MOST LOCATIONS EXCEPT FOR SOUTHEAST
MINNESOTA...TEMPERATURES COULD REALLY TANK TONIGHT. WENT SLIGHTLY
BELOW GUIDANCE FOR THE TYPICAL COLD SPOTS AS THINK THEY SHOULD BE
ABLE TO COME CLOSE TO ZERO. SINGLE DIGITS LOOK LIKELY ELSEWHERE.
925MB TEMPS ARE FAIRLY SIMILAR TO TODAY FOR SATURDAY...AND WITH
PLENTY OF SUN...HIGHS SHOULD TOP OUT CLOSE TO THOSE TODAY.
SATURDAY NIGHT AND SUNDAY...MODELS SHOW ANOTHER SHORTWAVE COMING OUT
OF SOUTH CENTRAL CANADA LATE SATURDAY...DROPPING SOUTHEAST INTO
WESTERN ILLINOIS BY 18Z SUNDAY. THIS SHORTWAVE WILL HELP TO KICK THE
TROUGH DROPPING INTO NEBRASKA EASTWARD...BUT ALSO BRING WITH IT A
SURGE OF DRY...COLDER AIR. BY 18Z SUNDAY...925MB TEMPS OVER THE
FORECAST AREA ARE AROUND -8C. PRIOR TO THE COLD AIR ARRIVAL...THERE
IS A CONCERN TO DEAL WITH WHICH IS THE SAME AS SATURDAY...LOW
STRATUS AND ANY LIGHT PRECIPITATION POSSIBLE WITH IT. IN THIS
CASE...MODELS HAVE AN AREA OF STRATUS COMING INTO THE FORECAST AREA
BEHIND A COLD FRONT ASSOCIATED WITH THE NEBRASKA TROUGH. VERY LITTLE
IF ANY ISENTROPIC LIFT IS NOTED WITHIN THIS STRATUS...SO THINK ANY
LIGHT PRECIPITATION POTENTIAL WOULD REMAIN OVER THE SOUTHEAST THIRD
OF THE AREA EARLY IN THE EVENING AHEAD OF THE FRONT. AGAIN...THIS IS
LIKELY TO BE FREEZING DRIZZLE GIVEN LACK OF ICE IN THE CLOUD. AFTER
MIDNIGHT...THERE ARE INDICATIONS OF A SECONDARY TROUGH WHICH IN
925MB TEMPS ALMOST LOOKS LIKE A WARM FRONT DROPPING SOUTH THROUGH
WISCONSIN. 270-275K ISENTROPIC LIFT PLOTS SHOW SOME LOW LEVEL LIFT
WITH THIS...LIKELY ENOUGH TO PRODUCE LIGHT PRECIPITATION. IT APPEARS
ICE WILL EXIST IN THE CLOUD THIS TIME...AIDED TOO BY MID CLOUDS
DROPPING SOUTH WITH THE SHORTWAVE COMING OUT OF SOUTH CENTRAL
CANADA. THUS...HAVE MAINTAINED A FLURRY MENTION. DRYING AND CLEARING
WILL TAKE PLACE SUNDAY MORNING FROM NORTHWEST TO SOUTHEAST. THE
INCREASE OF CLOUDS AND COLD ADVECTION WILL COUNTER-ACT EACH OTHER
SATURDAY NIGHT FOR LOWS...AND HAVE WENT WITH A BLEND OF GUIDANCE
SUGGESTING TEMPERATURES DROPPING INTO THE TEENS. SLIGHTLY COLDER DAY
EXPECTED ON SUNDAY GIVEN THE AFOREMENTIONED 925MB TEMPS.
SUNDAY NIGHT AND MONDAY...ATTENTION TURNS TO DEEP TROUGHING JUST OFF
THE WEST COAST OF NORTH AMERICA. OTHER THAN THE 04.12Z NAM...ALL
OTHER MODELS DEPICT THE TROUGH PROGRESSING EASTWARD INTO THE WESTERN
U.S. THROUGH THE WEEKEND AND SPLITTING INTO TWO. THE SOUTHERN
PART FORMS INTO A CUT-OFF LOW WHICH GETS STUCK IN THE SOUTHWESTERN
U.S.. THE NORTHERN PART IS A TROUGH THAT TRACKS ALONG THE
U.S./CANADIAN BORDER...BRINGING WITH IT A DYING COLD FRONT INTO
WESTERN MINNESOTA ON MONDAY. REGARDING THAT 04.12Z NAM...THE MODEL
HAS BEEN DISCOUNTED AS AN OUTLIER AS IT KEEPS A FULL SCALE TROUGH
AND MARCHES IT EASTWARD INTO THE PLAINS BY 00Z TUESDAY. NO MATTER
WHAT MODEL SOLUTION IS FOLLOWED...THIS PERIOD ENDS UP DRY WITH WARM
ADVECTION THROUGHOUT AS LOW LEVEL SOUTHWEST WINDS INCREASE AHEAD OF
THE APPROACHING SPLIT TROUGH AND DYING SURFACE COLD FRONT. 925MB
TEMPS CLIMB TO -2 TO -4C BY 18Z MONDAY WHILE 850MB TEMPS JUMP TO +2
TO +4C. THUS...MONDAY SHOULD END UP MUCH WARMER THAN SUNDAY WITH
MOST LOCATIONS TOPPING OUT FROM THE UPPER 20S TO MID 30S PER ECMWF
GUIDANCE. COLDEST LOCATIONS EXPECTED OVER SOUTHEAST MINNESOTA AND
NORTHEAST IOWA WITH HIGHER ALBEDO FROM SNOWPACK. LOWS SUNDAY NIGHT
LIKELY IN THE EVENING BEFORE SOUTHWEST WINDS PICK UP. FOLLOWED BLEND
OF GUIDANCE FOR LOWS.
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY
233 PM CST FRI JAN 4 2013
FOCUS AS HAS BEEN THE PAST FEW DAYS IS ON THE UPPER LOW IN THE
SOUTHWESTERN U.S. ON MONDAY. YET AGAIN THERE IS A SPLIT IN SCENARIOS
AMONGST MODEL HANDLING OF THIS UPPER LOW:
1. THE 04.12Z CANADIAN REPRESENTS A VERY FAST SCENARIO...LIFTING IT
NORTHEAST ACROSS CHICAGO TUESDAY NIGHT. WE WOULD END UP WITH A LIGHT
TO MODERATE SNOWFALL ACROSS THE FORECAST AREA TUESDAY INTO TUESDAY
NIGHT SHOULD THIS VERIFY.
2. NEXT BEHIND THE CANADIAN IS THE 04.12Z GFS...LIFTING IT FROM
TEXAS ON TUESDAY INTO THE OHIO VALLEY ON WEDNESDAY. THIS SCENARIO
WOULD IT PAN OUT WOULD KEEP THE AREA DRY AND TEMPERATURES ABOVE
NORMAL THROUGH THURSDAY.
3. LASTLY...THE 04.12Z ECMWF/UKMET ARE EXTREMELY CONSISTENT WITH
PAST ECMWF RUNS...HAVING THE UPPER LOW CROSS NORTHERN MEXICO ON
TUESDAY...SHIFTING INTO TEXAS ON WEDNESDAY...THEN LIFTING INTO
ILLINOIS ON THURSDAY. THIS SCENARIO WOULD YIELD ABOVE NORMAL
TEMPERATURES THROUGH THURSDAY...WITH DRY WEATHER THROUGH WEDNESDAY
EVENING...RAIN TO MUCH OF THE AREA FOR LATE WEDNESDAY NIGHT INTO
THURSDAY...THEN TAPERING OFF TO A SNOW OR RAIN/SNOW MIX THURSDAY
NIGHT.
THE WHOLE PROBLEM RESULTING IN THE VARIOUS SCENARIOS STARTS ON
SUNDAY...REGARDING HOW QUICK THE DEEP UPPER TROUGH SPLITS INTO TWO
AND HOW FAST UPPER RIDGING CAN BUILD INTO THE PACIFIC NORTHWEST
BEHIND IT. PER HPC AND WANTING TO FOLLOW THE CONSISTENT AND GOOD
EXTENDED VERIFYING ECMWF...LEANED THE LONG TERM FORECAST MORE
TOWARDS THE ECMWF SOLUTION. THIS ALSO IS IN BETTER AGREEMENT WITH
THE PREVIOUS FORECAST. STILL HAVE ENDED UP KEEPING A SNOW OR
RAIN/SNOW MIX IN FOR WEDNESDAY NIGHT INTO THURSDAY MORNING...TO
HANDLE UNCERTAINTY ON THE TEMPERATURE RISE AND NOT WANTING TO
INTRODUCE FREEZING RAIN SINCE THAT TYPE SEEMS UNLIKELY.
AFTER THURSDAY...NEW DEEP TROUGHING IS FORECAST TO FORM BY ALL
MODELS OVER THE WESTERN U.S....WHICH IS ONE OF THE FEATURES THAT
HELPS KICK OUT THE UPPER LOW IN THE ECMWF/UKMET. SHORTWAVES EJECTING
OUT OF THE TROUGH REQUIRE CHANCES OF SNOW IN FOR FRIDAY. COOLER
TEMPERATURES ARE LIKELY AS WELL...THOUGH AT LEAST FOR FRIDAY STILL
CLOSE TO NORMAL AS THE DEEPER COLDER AIR ASSOCIATED WITH THE TROUGH
HOLDS OFF UNTIL THE WEEKEND.
&&
.AVIATION...THROUGH 06Z SUNDAY
1141 PM CST FRI JAN 4 2013
CLEAR SKIES AND LIGHT WINDS WILL CONTINUE TO RULE INTO THE MORNING
HOURS WITH SOME HAZE/MIST POSSIBLE AT RST IF WINDS CAN REMAIN
LIGHT AT LESS THAN 5KTS. FORECAST SOUNDINGS SHOW A FAIRLY STEEP
LOW LEVEL INVERSION WITH ANY MOISTURE BEING LOCKED IN AT THE VERY
LOWEST LEVEL. SO ANY HZ/BR THAT DOES FORM WILL BE VERY SHALLOW AND
IS NOT EXPECTED TO DROP BELOW MVFR. THAT SAID...SOME OBS HAVE
QUICKLY DROPPED DOWN TO A MILE ACROSS PORTIONS OF NORTHERN
MINNESOTA AND WISCONSIN WHERE WINDS ARE MUCH LIGHTER.
THE FOCUS THEN GOES TO LATE SATURDAY AFTERNOON AND EVENING AS LOW
LEVEL MOISTURE IS ON THE INCREASE AHEAD OF A PAIR OF SYSTEMS
MOVING INTO THE REGION. DESPITE THE DEEPER LOW LEVEL MOISTURE
APPEARING TO STAY TO THE SOUTHEAST...FORECAST SOUNDINGS SHOW THAT
THERE SHOULD BE ENOUGH MOISTURE POOLING UNDER A SHALLOW INVERSION
IN THE EVENING FOR LOW LEVEL CLOUDS TO FORM. GIVEN THAT THIS HAS
BEEN A CONSISTENT SIGNAL FOR A FEW DAYS NOW...DECIDED TO GO AHEAD
AND PUT THIS INTO THE TAFS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
233 PM CST FRI JAN 4 2013
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS JACKSON KY
131 AM EST MON JAN 7 2013
.UPDATE...
ISSUED AT 130 AM EST MON JAN 7 2013
CLOUDS WILL LIKELY LINGER MUCH LONGER THAN ORIGINALLY THOUGHT AND
INDICATED FROM MODELS. OUTSIDE OF A BRIEF CLEARING PUSHING SOUTH
PRESENTLY...CLOUDS EXTEND BACK WELL TO THE NORTH AND UNTIL THE RIDGE
AXIS PUSHES ACROSS THE AREA LATER THIS AFTERNOON...WE WILL LIKELY SEE
LOW CLOUDS HANG IN SUPPORTED BY SOME WEAK NORTHEAST TO EASTERLY LOW
LEVEL FLOW. RUC SEEMS TO HAVE THE BEST HANDLE ON THE CLOUDS. HAVE
UPDATED THE FORECAST ACCORDINGLY AND MAY NEED TO TAKE A LOOK AT HIGH
TEMPERATURES TODAY AS LOW CLOUDS COULD KEEP THINGS A BIT COOLER. THE
EXCEPTION IS IN THE FAR SOUTHWEST WHICH SHOULD CLEAR OUT BASED ON
CURRENT SATELLITE TRENDS. THUS...KEPT OVERNIGHT LOWS COOLER TO THE
SOUTHWEST. OTHERWISE...ADJUSTED EVERYONE ELSE UP WITH THEIR LOWS
TONIGHT.
UPDATE ISSUED AT 826 PM EST SUN JAN 6 2013
PCPN HAS MOVED EAST AND WINDS HAVE SHIFTED TO THE NORTHWEST BUT ARE
STILL GUSTY. WINDS SHOULD DIMINISH LATER THIS EVENING. HAVE UPDATED
ZONES AND GRIDS WITH CURRENT CONDITIONS.
UPDATE ISSUED AT 625 PM EST SUN JAN 6 2013
SFC COLD FRONT IS THRU ABOUT HALF THE CWFA. WINDS BEHIND THE FRONT
HAVE SHIFTED TO THE NORTHWEST AND ARE GUSTY. FEW SPRINKLES OR LIGHT
DRIZZLE PUSHING INTO THE ERN COUNTIES. UPDATED GRIDS BUT ZONES STILL
IN GOOD SHAPE. NEXT UPDATE AFTER PCPN EXITS THE CWFA.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 240 PM EST SUN JAN 6 2013
THE SURFACE COLD FRONT IS CURRENTLY ALIGNED JUST WEST OF A LINE FROM
KCVG TO KSDF TO KBWG. THE MODELS CONTINUE TO SHOW THE BETTER CHANCES
OF MEASURABLE QPF MAINLY NORTHEAST OF THE AREA. AS SUCH...WILL ONLY
ALLOW FOR A SLIGHT CHANCE OF MEASURABLE PRECIPITATION FROM LATE THIS
AFTERNOON THROUGH EARLY THIS EVENING...MAINLY FOR THE NORTHEASTERN TWO
THIRDS OF THE COUNTIES...WITH JUST SOME SPRINKLES POSSIBLE FOR THE
SOUTHWEST.
CLEARING WILL LIKELY BE TOUGH TONIGHT...WITH SURFACE COLD AIR
ADVECTION AND NORTHWEST WINDS FAVORING A LINGERING STRATOCU DECK.
WILL THEREFORE FAVOR THE NAM IDEA ON TEMPERATURES...GENERALLY LOWER
20S IN THE WEST...AND MORE MID 20S IN THE EAST.
SKIES WILL CLEAR OUT DURING MORNING HOURS ON MONDAY...WITH
HIGHS RECOVERING TO THE LOWER TO MIDDLE 40S AS UPPER LEVEL RIDGING
BUILDS IN OVERHEAD. BESIDES SOME HIGH CIRRUS...MONDAY NIGHT WILL BE
CLEAR...WITH SOME OF THE DEEPER VALLEYS IN THE EAST LIKELY GETTING
DOWN INTO THE TEENS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 355 PM EST SUN JAN 6 2013
UPPER LEVEL AND SFC RIDGING ARE EXPECTED TO BE SHIFTING EAST OF THE
REGION AT THE START OF THE PERIOD. MODELS THEN TAKE A TROUGH FROM THE
NORTHERN PLAINS ACROSS THE GREAT LAKES AND INTO EASTERN CANADA FROM
TUESDAY INTO WEDNESDAY WHILE A CLOSED LOW INITIALLY OVER NORTHERN
MEXICO MEANDERS TOWARD THE SOUTHERN PLAINS. THE TROUGH PASSING BY TO
OUR NORTH ON TUE NIGHT INTO EARLY WED SHOULD SEND A SFC TROUGH ACROSS
THE REGION ON TUE NIGHT INTO EARLY ON WED...ALONG WHICH THE ECMWF AND
GFS BOTH HAVE MOISTURE INCREASING BRIEFLY. THE GFS IS MORE ROBUST
WITH IT...BUT DOES HAVE SOME SUPPORT FORM THE ECMWF. AT THE SAME TIME...
THE MODELS SEEM TO BE DEVELOPING SOME LIFT ACROSS THE AREA ASSOCIATED
WITH THE RIGHT ENTRANCE REGION PASSING BY TO OUR NORTH DURING THE
LATE TUE NIGHT INTO EARLY ON WED PERIOD. POPS WERE INCREASED TO
SLIGHT CHANCE ACROSS THE SOUTHWEST HALF OF THE AREA FOR THIS FOR LATE
TUE NIGHT INTO EARLY ON WED...PER ISC COORDINATION.
THEN...MODELS TRACK THE UPPER LEVEL LOW AND IT SFC SYSTEM SLOWLY FROM
THE SOUTHERN PLAINS TO THE MID MS VALLEY FROM WED INTO THU EVENING
PER GFS OR A BIT LATER AND SOUTHEAST THU NIGHT PER ECMWF. THIS WOULD
HAVE THE WARM FRONT ASSOCIATED WITH THE SYSTEM MOVING NORTH OF THE
AREA ON THU EVENING OR THU NIGHT WITH THE COLD FRONT TO FOLLOW ON
FRI. THE HIGHEST POPS ON AVERAGE ACROSS THE REGION WILL BE ON THU ON
AVERAGE...AND HIGHEST DURING THE WED NIGHT INTO THU NIGHT PERIOD IN
THE WEST WITH THE UPPER SYSTEM TO PASS BY TO THE NORTHWEST. THE
HIGHEST POPS ON FRI WERE IN THE EAST IN ADVANCE OF THE COLD FRONT.
THIS FRONT...HOWEVER...WILL MAINLY JUST USHER IN DRIER AIR WILL
LITTLE TEMP DIFFERENCES ANTICIPATED BEHIND IT.
THERE SHOULD BE A RATHER BRIEF WINDOW OF INACTIVE WEATHER FROM
FRI AFTERNOON INTO MUCH OF SAT NIGHT. AFTER THAT TIME...THE NEXT
TROUGH AND ASSOCIATED SFC SYSTEM WILL BEGIN TO APPROACH FROM THE
WEST...BUT EVENTUALLY SHOULD SLOW DOWN AND PERHAPS STALL AS IT NEARS
THE REGION. THAT SCENARIO WOULD POINT TOWARD THREAT OF HEAVY
RAIN...BUT MODEL DIFFERENCES REMAIN BETWEEN MODELS AND RUN TO RUN.
WITH THAT IN MIND...A FORECAST VERY CLOSE TO THE GRID LOAD WAS
FOLLOWED FOR POPS LATE IN THE PERIOD.
TEMPERATURE RANGES FROM WED ON WILL BE DIURNALLY LIMITED DUE TO
EXPECTED CLOUD COVER AND PRECIP CHANCES. READINGS THROUGH THE ENTIRE
PERIOD WILL AVERAGE ABOVE NORMAL...PERHAPS NEARLY 20 DEGREES ABOVE
NORMAL FOR THU NIGHT THROUGH SAT NIGHT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 130 AM EST MON JAN 7 2013
MVFR CIGS WILL CONTINUE OVERNIGHT EXCEPT ACROSS SOUTH CENTRAL
KENTUCKY NEAR KSME...WHERE SKIES ARE EXPECTED TO CLEAR SHORTLY.
OTHERWISE...ANY CLEARING FURTHER EAST IS EXPECTED TO TAKE AWHILE WITH
CLOUDS HOLDING IN A JKL PERHAPS WELL PAST DAYBREAK AND MAYBE EVEN
INTO THE EARLY AFTERNOON HOURS. BY THIS EVENING...WE SHOULD FINALLY
SEE A BETTER PUSH FOR CLEARING SKIES AS THE MID LEVEL RIDGE PUSHES
EAST. WINDS WILL TURN MORE LIGHT AND VARIABLE AS WE HEAD THROUGH THE
NIGHT AND REMAIN THAT WAY THROUGH TODAY AND TONIGHT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...GEOGERIAN
LONG TERM....JP
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS DULUTH MN
300 AM CST MON JAN 7 2013
.SHORT TERM...TODAY THROUGH TUESDAY.
SURFACE LOW PRESSURE OVER SOUTHERN MANITOBA WILL MOVE INTO ONTARIO
TODAY. NORTHERN PORTIONS OF THE FORECAST AREA WILL SEE MORE CLOUDS
AND A SLIGHT CHANCE OF FLURRIES DURING THE DAY. THE LOW PRESSURE
SYSTEM COMBINED WITH A SURFACE HIGH PRESSURE SYSTEM OVER THE OHIO
RIVER VALLEY WILL BRING BRISK SOUTHWESTERLY WINDS TO THE AREA.
CLOUDS WILL DECREASE OVER THE NORTH TONIGHT AS THE LOW MOVES FURTHER
TO THE EAST. ON TUESDAY A LOW PRESSURE SYSTEM OVER SOUTHERN
SASKATCHEWAN WILL MOVE ALONG THE INTERNATIONAL BORDER AND BRING A
CHANCE OF LIGHT SNOW TO THE NORTHLAND ON TUESDAY AFTERNOON.
TEMPERATURES WILL BE ABOVE NORMAL TODAY WITH THE BRISK SOUTHWESTERLY
WINDS THAT WILL BRING HIGHS INTO THE UPPER 20`S AND LOWER 30`S.
HIGHS ON TUESDAY WILL ALSO BE ABOVE NORMAL WITH TEMPERATURES
GENERALLY IN THE LOWER 30`S.
.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY.
A SFC LOW WILL TRAVEL FROM MANITOBA TO ONTARIO TUESDAY NIGHT
ACCOMPANIED BY A NEGATIVELY TILTED UPPER TROF. THESE FEATURES WILL
PUSH A FRONTAL BOUNDARY THROUGH THE FA. WILL CONTINUE TO CARRY THE
CHANCE POPS...TRENDING DOWNWARD OVERNIGHT. SOME LIGHT ACCUMULATION
IS POSSIBLE ESPECIALLY NEAR THE CANADIAN BORDER WHERE UP TO AN INCH
COULD FALL...LESSER AMOUNTS FURTHER SOUTH. SOME LINGERING LIGHT SNOW
IS PROBABLE OVER THE ARROWHEAD WEDNESDAY MORNING AS THE UPPER TROF
DEPARTS. RIDGING FOLLOWS FOR WEDNESDAY AFTERNOON. THE RIDGE AXIS
MOVES FARTHER EAST WEDNESDAY NIGHT WHICH ALLOWS FOR STRONG WAA TO
SET UP AHEAD OF A DEVELOPING SYSTEM IN THE ROCKIES. 850MB TEMPS
SURGE TO AROUND 7C BY 12Z THURSDAY LEADING TO MAX TEMPS IN THE
MIDDLE TO UPPER 30S ON THURSDAY. CLOUDS WILL BE ON THE INCREASE
THURSDAY AFTERNOON AS A CLOSED UPPER LOW MOVES THROUGH THE SOUTHERN
PLAINS. THIS WILL HELP PULL SOME GULF MOISTURE NORTHWARD. AS THE
UPPER LOW OPENS INTO A LONG WAVE TROF THURSDAY NIGHT...THE FA WILL
BE BETWEEN A SFC LOW NEAR CHICAGO AND ANOTHER OVER THE NORTHERN
PLAINS. WITH THE WARM AIR IN PLACE...HAVE SMALL POPS OVER THE
SOUTHERN FA FOR LIGHT RAIN THURSDAY AFTERNOON. AS COOLING OCCURS
THURSDAY NIGHT NEAR THE SFC...A MIX OF LIGHT RAIN/FREEZING RAIN IS
POSSIBLE WHERE SFC TEMPS WILL BE NEAR 32F. HAVE A MENTION OF LIGHT
SNOW OVER THE FAR NW PORTION OF THE FA WHICH IS SUPPORTED BY
FORECAST SOUNDINGS. AS THE SFC LOW MOVES FROM ND INTO SW ONTARIO ON
FRIDAY...WILL SEE AN OPPORTUNITY FOR LIGHT RAIN IN THE SE
FA...MIXING WITH LIGHT SNOW IN THE CENTRAL FA...TO ALL SNOW OVER THE
NORTH AND WEST AS COLDER AIR ARRIVES. AT THIS POINT...THE MODELS
BEGIN TO DIVERGE AS THE OVERALL UPPER FLOW BECOMES SW THANKS TO A
LARGE WEST COAST TROF. WILL CONTINUE WITH THE BLENDED APPROACH TO
POPS FOR THE REST OF THE EXTENDED AND THE PTYPE SHOULD BE ALL SNOW
WITH COLDER AIR LEAKING DOWN FROM CANADA.
&&
.AVIATION...06Z TAFS
MAINLY VFR CONDITIONS COVERED THE NORTHLAND LATE THIS EVENING. THE
MVFR CEILINGS COMING OFF OF LAKE SUPERIOR HAVE DIMINISHED ALONG
THE NORTH SHORE AS LOW TEMPERATURES HAVE RISEN. IFR CEILINGS IN
NORTHWEST MINNESOTA MAY STILL BRUSH KINL...BUT WE DID NOT PUT ANY
MENTION IN THE TAF ATTM.
A SHORTWAVE SCOOTING ALONG THE INTERNATIONAL BORDER MAY BRING SOME
LOWER CEILINGS TO KINL MONDAY MORNING. THE RAP 900MB CONDENSATION
PRESSURE DEFICITS SEEM TO BE HANDLING THIS FAIRLY WELL...AND SHOW
LOWER VALUES REACHING KINL AROUND 13Z...BUT IT JUST BRUSHES THAT
AREA. WE BRING IN PREDOMINATE MVFR CEILINGS THERE IN THE
AFTERNOON. SOME FLURRIES MAY ACCOMPANY THOSE LOWER CEILINGS.
LLWS WILL REMAIN A THREAT TONIGHT. THE WOOD LAKE PROFILER SHOWS
50 KNOTS AT 925MB AND THAT IS LINE WITH THE NAM.
&&
.POINT TEMPS/POPS...
DLH 31 14 30 22 / 0 0 30 40
INL 31 10 28 19 / 10 10 30 50
BRD 31 12 32 20 / 0 0 30 30
HYR 32 12 33 22 / 0 0 20 40
ASX 32 17 35 25 / 0 0 10 40
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 10 PM CST THIS EVENING FOR LSZ121-
140>148.
&&
$$
SHORT TERM...KK
LONG TERM....GSF
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS DULUTH MN
1144 PM CST SUN JAN 6 2013
.AVIATION...06Z TAFS
MAINLY VFR CONDITIONS COVERED THE NORTHLAND LATE THIS EVENING. THE
MVFR CEILINGS COMING OFF OF LAKE SUPERIOR HAVE DIMINISHED ALONG
THE NORTH SHORE AS LOW TEMPERATURES HAVE RISEN. IFR CEILINGS IN
NORTHWEST MINNESOTA MAY STILL BRUSH KINL...BUT WE DID NOT PUT ANY
MENTION IN THE TAF ATTM.
A SHORTWAVE SCOOTING ALONG THE INTERNATIONAL BORDER MAY BRING SOME
LOWER CEILINGS TO KINL MONDAY MORNING. THE RAP 900MB CONDENSATION
PRESSURE DEFICITS SEEM TO BE HANDLING THIS FAIRLY WELL...AND SHOW
LOWER VALUES REACHING KINL AROUND 13Z...BUT IT JUST BRUSHES THAT
AREA. WE BRING IN PREDOMINATE MVFR CEILINGS THERE IN THE
AFTERNOON. SOME FLURRIES MAY ACCOMPANY THOSE LOWER CEILINGS.
LLWS WILL REMAIN A THREAT TONIGHT. THE WOOD LAKE PROFILER SHOWS
50 KNOTS AT 925MB AND THAT IS LINE WITH THE NAM.
&&
.PREV DISCUSSION... /ISSUED 729 PM CST SUN JAN 6 2013/
UPDATE...
TEMPERATURES HAVE DROPPED QUICKLY THIS EVENING...WITH SEVERAL
AREAS ALREADY BELOW FORECAST MINS. TEMPERATURES WILL BE A
CHALLENGE TONIGHT. WINDS SHOULD BE INCREASING...AND THAT WILL
ALLOW TEMPS TO REBOUND IN SPOTS...OR AT LEAST SLOW THE RAPID DROP.
AS LOW LEVEL WINDS HAVE BECOMING SOUTHERLY...LAKE CLOUDS HAVE
MOVED ASHORE BETWEEN SILVER BAY AND GRAND PORTAGE. DELTA-T VALUES
FROM THE SURFACE TO 850MB WILL BE AS HIGH AS 13C AT GRAND PORTAGE
EARLY THIS EVENING...BUT WAA WILL LEAD LOWERING DELTA-T`S AS THE
NIGHT PROGRESSES. WE DON`T EXPECT MUCH IN THE WAY OF SNOW SHOWERS
AS THE AIRMASS IS QUITE DRY...AND THEN STABILITIES WILL INCREASE.
PREV DISCUSSION... /ISSUED 540 PM CST SUN JAN 6 2013/
AVIATION...00Z TAFS
MAINLY VFR CONDITIONS COVERED THE NORTHLAND THIS EVENING...BUT
THERE WERE SOME MVFR CEILINGS COMING ONSHORE BETWEEN SILVER BAY
AND GRAND PORTAGE DUE TO SOUTHERLY WINDS. WE DO NOT EXPECT MUCH IN
THE WAY OF SNOW SHOWERS AS LOW LEVEL TEMPS ARE FORECAST TO
INCREASE OVERNIGHT. THERE WERE ALSO SOME IFR CEILINGS OVER WESTERN
AROUND KADC/KPKD NORTHWEST INTO THE UPPER RED RIVER VALLEY. THE
RAP SHOWS SOME LOW CEILINGS MAY AFFECT KINL FOR A FEW HOURS THIS
EVENING.
INCREASING SOUTH-SOUTHWEST LLJ WILL CREATE SOME LLWS AT ALL TAFS
FOR A PERIOD.
PREV DISCUSSION... /ISSUED 311 PM CST SUN JAN 6 2013/
SHORT TERM...
THIS AFTERNOON/TONIGHT THROUGH MONDAY NIGHT...
FAIRLY QUIET CONDITIONS THROUGH THE SHORT TERM WITH ONLY A FEW
FLURRIES POSSIBLE ACROSS THE NORTHERN COUNTIES DURING THE DAY
TOMORROW. TEMPERATURES WILL BE VERY MILD TONIGHT THROUGH MONDAY
NIGHT.
UPPER RIDGE BUILDING IN ACROSS THE DAKOTAS WITH A SFC RIDGE AXIS
EXTENDING FROM JAMES BAY SWWD INTO THE MO RIVER VALLEY. THE NEXT
SYSTEM...CURRENTLY LOCATED OVER THE CANADIAN ROCKIES...WILL MOVE
EWD ACROSS SRN CANADA AND BRUSH PARTS OF FAR NRN MN WITH A FEW
FLURRIES LATE TONIGHT AND THROUGH THE DAY MONDAY. THE MOST
FAVORABLE FORCING FOR SNOWFALL WILL REMAIN WELL TO THE
NORTH...CLOSER TO THE SFC LOW MOVING THROUGH SRN MANITOBA INTO WRN
ONTARIO. WILL SEE MAINLY ADDITIONAL CLOUD COVER WITH THIS SYSTEM
ACROSS THE NRN HALF OF THE FORECAST AREA...WITH PARTLY CLOUDY TO
MOSTLY SUNNY SKIES TO THE SOUTH. SHOULD SEE EVEN MORE CLEARING
MONDAY NIGHT AS THE SYSTEM MOVES TO THE EAST AND HIGH PRESSURE
BUILDS BACK IN FROM THE WEST.
TEMPERATURES TONIGHT WILL DROP INTO THE SINGLE DIGITS AND TEENS
ABOVE ZERO...WITH THE COLDEST TEMPS LIKELY OVER NW WI WHERE THE
GREATEST AMT OF CLEARING WILL OCCUR. STRONG SWLY FLOW TOMORROW
WILL USHER IN A SLIGHTLY WARMER AIR MASS THROUGH THE DAY AND ALLOW
TEMPERATURES TO RISE INTO THE UPPER 20S AND LOWER 30S...SOME 10
DEGREES ABOVE NORMAL. TEMPS WILL DROP INTO THE SINGLE DIGITS AGAIN
MON NIGHT.
LONG TERM...
TUESDAY THROUGH SUNDAY...
A SHORTWAVE WILL MOVE ACROSS THE NORTH DAKOTA/CANADA BORDER ON
TUESDAY AND THEN LIFT INTO NW ONTARIO BY TUESDAY NIGHT. THIS WILL
SPREAD LIGHT SNOW ACROSS THE REGION DURING THAT TIME AS THE TROUGH
DIGS AND TAKES ON A BIT OF A NEGATIVE TILT. THINGS SHOULD DRY OUT
FOR WEDNESDAY WITH A RIDGE OF HIGH PRESSURE ACROSS THE CWA. WAA
WILL ALREADY TAKE OVER WEDNESDAY NIGHT AS SOUTHWEST WINDS DEVELOP
AHEAD OF LOW PRESSURE MOVING THROUGH THE MANITOBA LAKES REGION. AN
UPPER LOW MOVING NORTHWARD FROM THE PLAINS STATES WILL MOVE IN ON
THURSDAY AND THURSDAY NIGHT. WILL HOLD OFF ON INTRODUCING
PRECIPITATION UNTIL THURSDAY AFTERNOON. THAT MAY EVEN BE A BIT
QUICK...BUT THE GFS DOES HAVE PRECIPITATION MOVING IN DURING THE
AFTERNOON IN THE SOUTH. THE ECMWF IS MUCH FURTHER SOUTH. THE
PRECIPITATION SHOULD CONTINUE INTO FRIDAY AND EVEN INTO THE
WEEKEND AS LOW PRESSURE EVOLVES TO OUR W/SW. THE MODELS CONTINUE
TO SHOW SOME PRETTY SIZEABLE DIFFERENCES WITH REGARD TO THE
EVOLUTION OF A STRONG SURFACE LOW BY 18Z SATURDAY. THE ECMWF
PRETTY MUCH CONFINES THE HEAVIEST PRECIPITATION TO OUR NW...WHILE
THE GFS FAVORS OUR CWA. NO MATTER WHAT...THE MODELS CONTINUE TO
PICK UP ON SOMETHING OF INTEREST FOR NEXT WEEKEND. WAY TOO EARLY
TO DETERMINE HOW EXACTLY IT WILL AFFECT OUR CWA AT THIS POINT.
TEMPERATURES WILL WARM CONSIDERABLY DURING THE WEEK WITH
TEMPERATURES SOARING THROUGH THE 30S. COULD EVEN SEE A 40 DEGREE
READING SOUTH ON THURSDAY/FRIDAY.
&&
.POINT TEMPS/POPS...
DLH 15 30 14 30 / 0 0 0 30
INL 11 30 10 28 / 10 10 10 30
BRD 12 30 12 32 / 0 0 0 30
HYR 13 31 12 34 / 0 0 0 20
ASX 15 31 17 35 / 0 0 0 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 10 PM CST MONDAY FOR LSZ121-140>148.
&&
$$
SHORT TERM...MELDE
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
445 AM EST MON JAN 7 2013
.SYNOPSIS...
HIGH PRESSURE WILL DOMINATE THE REGIONAL PATTERN THROUGH MID-
WEEK...BRINGING DRY AND TRANQUIL WEATHER CONDITIONS TO THE AREA.
A RELATIVELY MILD SOUTHWEST RETURN FLOW SHOULD ALLOW TEMPERATURES
TO MODERATE WELL-ABOVE SEASONAL CLIMATE NORMALS BY WEDNESDAY AND
THURSDAY. THE NEXT CHANCE FOR PRECIPITATION WILL COME BY THE END
OF THE WEEK...AS LOW PRESSURE MOVES INTO THE GREAT LAKES REGION.
&&
.NEAR TERM /UNTIL NOON TODAY/...
EXTENSIVE LOW-LEVEL MSTR/CLOUD COVER IN THE WAKE OF A NEBULOUS
SFC LOW MOVG AWAY FROM NRN NEW ENGLAND WILL PERSIST ACRS MUCH OF
WESTERN AND CENTRAL PA THIS MORNING...AS UPSLOPE WLY FLOW
CONTINUES TO PROVIDE SUFFICIENT /ALBEIT WEAK/ OROGRAPHIC LIFT OVER
THE ALLEGHENIES. REGIONAL RADAR MOSAIC ALSO INDICATES SOME LGT
PCPN ACRS THE WRN AND NRN MTNS...EITHER IN THE FORM OF -SN OR
PATCHY -FZDZ. THE RAP AND 4KM NAM FCST SOUNDINGS FAVOR -FZDZ
PROFILES THRU THE PRE DAWN HOURS AS MID-LVL MSTR IS STRIPPED AWAY.
THE CLOUD COVER AND STEADY 5-10KT WNW WIND WILL KEEP TEMPS IN
THE UPPER 20S TO MID 30S. LOW CLOUDS WILL LKLY BE SLOW TO ERODE
AFT SUNRISE ESP IN THE WRN MTNS AS LOW-LEVEL MSTR GETS TRAPPED
UNDER SFC RIDGE MOVG EWD FM THE OH VLY. HOWEVER ANTICIPATE SOME
BINOVC E OF THE MTNS.
&&
.SHORT TERM /NOON TODAY THROUGH 6 AM TUESDAY/...
LG SCALE SUBSIDENCE ASSOC WITH THE AFOREMENTIONED SFC HIGH AND
BACKING LLVL FLOW /TO THE SSW/ SHOULD AFFORD MORE PEAKS OF SUN AS
THE DAY WEARS ON. HIGHS SHOULD CLIMB A FEW DEGS ABOVE EARLY
JANUARY CLIMATE NORMALS...RANGING FROM THE LOW-MID 30S OVER THE
ALLEGHENIES TO THE LOW 40S OVER THE LWR SUSQ VLY. EXPECT MAINLY
CLR SKIES OVERNIGHT AS THE RIDGE MOVES OVER THE AREA...WITH LOWS
VARYING FROM THE UPPER TEENS TO MID 20S.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
MODERATELY AMPLIFIED SPLIT FLOW PATTERN WILL PREVAIL THROUGH THE
UPCOMING WORKWEEK...WITH THE NORTHERN STREAM TAPPING MAINLY PACIFIC
AIR THROUGH THE PERIOD.
EARLY IN THE PERIOD...A RIDGE OF SFC HIGH PRESSURE WILL EXTEND FROM
THE WESTERN ATLANTIC TO THE VIRGINIAS...WITH A DEVELOPING SWRLY FLOW
AND ABUNDANT SUNSHINE TEAMING UP TO BOOST TEMPS SOME 7-10F ABOVE
NORMAL. POPS WILL BE ZERO FOR THE DAY TUESDAY.
FOR TUESDAY NIGHT AND WEDNESDAY...A WELL DEFINED AND FAST MOVING NRN
STREAM SHORTWAVE WILL TRACK FROM THE UPPER GLAKES...TO THE NERN U.S.
BY 00Z THUR. BROAD...UPPER DIFFLUENT FLOW BETWEEN TWO DISTINCT 300
MB JET MAXES IN EXCESS OF 100 KTS AND A BRIEF PUSH OF NEAR 0.50 INCH
PWATS WILL BRING JUST A FEW TO SVRL HOUR PERIOD LAYERED BROKEN CLOUD
COVER AND PERHAPS A FEW SPRINKLES...OR BRIEF LIGHT RAIN/SNOW SHOWERS
ACROSS THE WRN MTNS DURING THE EARLY TO MID MORNING HOURS WEDNESDAY
/INVOF OF A MOISTURE CHALLENGED WARM FRONT/.
FAIRLY STRONG SUBSIDENCE IN THE WARM SECTOR WILL FOLLOW FOR THE
MIDDAY AND AFTERNOON HOURS WEDNESDAY...BENEATH THE THERMALLY
INDIRECT RIGHT EXIT REGION OF A 150 KT UPPER JET STREAK CROSSING NEW
YORK STATE. PARTLY TO MOSTLY SUNNY SKIES FOR WEDNESDAY AFTERNOON
WILL BOOST TEMPS FURTHER /BY ABOUT 5 DEG F HIGHER THAN TUESDAY/.
HIGHS WED AFTN WILL VARY FROM THE LOWER 40S ACROSS THE NW MTNS TO
THE LOWER 50S IN SOME OF THE SOUTHERN VALLEYS. THESE READINGS WILL
BE ROUGHLY 10-15F ABOVE NORMAL...WITH THE GREATER DEPARTURES
OCCURRING ACROSS THE MTNS.
WESTERLY WINDS WILL QUICKLY INCREASE WEDNESDAY MORNING...AND WILL
LIKELY GUST BETWEEN 30-35 MPH AT TIMES IN THE AFTERNOON /ESPECIALLY
ACROSS THE HIGHER TERRAIN OF THE NORTH AND WEST/.
A BRIEF SHOT OF SLIGHTLY COOLER AIR FOLLOWS THE EXIT OF THIS NRN
STREAM WAVE WEDNESDAY NIGHT. AS WINDS DIMINISH QUICKLY IN THE
EVENING AND SKIES STAY MAINLY CLEAR...TEMPS WILL FALL TO AROUND 20F
ACROSS THE NRN MTNS /WHERE THE DEEPEST SNOW COVER WILL REMAIN/ TO
NEAR 30F IN THE SOUTHEAST.
SFC HIGH WILL BE CENTERED ACROSS WRN PENN TO START THE DAY
THURSDAY...AND WILL SLIDE EAST ACROSS THE COMMONWEALTH DURING THE
AFTERNOON. A SLOW MOVING...CLOSED UPPER LOW IMPACTING FAR WEST TEXAS
EARLY IN THE WEEK WILL LIFT NE WED AND THURSDAY...AS AN OPENING WAVE
IN THE AMPLIFYING SWRLY FLOW ACROSS THE MIDWEST AND GLAKES REGION.
INCREASING DEEP-LAYER WARM ADVECTION AHEAD OF THIS SYSTEM LATE
THURSDAY INTO EARLY FRIDAY WILL BRING THICKENING CLOUDS AND HIGH CHC
TO LOW LIKELY POPS FOR RAIN SHOWERS. THE VERY DRY LLVLS COULD COOL
TO JUST BELOW FREEZING AS THE PRECIP SPREADS NE THURSDAY
NIGHT...POSSIBLY LEADING TO SOME SPOTTY LIGHT MIXED PRECIP...MAINLY
TO THE NORTH AND EAST OF KIPT WHERE A FEW HOURS OF CLEARING ARE
POSSIBLE DURING THE EVENING HOURS.
IN THE WAKE OF THIS MINOR PRECIP EVENT AND SOME ADDITIONAL
SNOWMELT/RUNOFF...TEMPS WILL SLOWLY RISE TO EVEN GREATER DEPARTURES
FROM NORMAL AS A VERY ANOMALOUS UPPER RIDGE OF PLUS 2-3 ST
DEVIATIONS AMPLIFIES ACROSS THE GLAKES...EAST THROUGH THE NE U.S.
AND SERN CANADA.
HIGH TEMPS BY SATURDAY COULD BE EASILY 15-20F ABOVE NORMAL ACROSS
THE CENTRAL AND SRN PORTIONS OF THE CWA...WITH MAXES RANGING FROM
THE MID 40S IN THE NORTH...TO LOWER AND MID 50S THROUGHOUT SOUTHERN
PENN.
INCREASING CHCS FOR RAIN WILL DEVELOP FOR THE SECOND HALF OF THE
WEEKEND AS A SLOW MOVING COLD FRONT PRESSES EAST TWD THE REGION AND
ONE OR MORE WAVES OF SFC LOW PRESSURE RIDE NEWD ALONG IT.
A BIG PATTERN CHANGE IS LIKELY THE FOLLOWING WEEK AS SIGNIFICANT
RIDGING DEVELOPS ACROSS THE EASTERN PACIFIC AND ALLOWS A LARGE AREA
OF ARCTIC AIR TO SURGE SE INTO THE NRN ROCKIES AND UPPER MID VALLEY
MONDAY AND TUESDAY...WITH COOLER AIR OOZING INTO THE MIDDLE ATLANTIC
AND LOWER GLAKES REGION.
THE NEXT POTENTIAL WINTRY /OR SIGNIFICANT RAIN EVENT/ WILL LIKELY BE
NEXT TUESDAY INTO WEDNESDAY AS THE NRN AND SRN STREAM PHASES INTO A
HIGH AMPLITUDE TROUGH FROM THE UPPER GLAKES...SWD TO THE LOWER MISS
VALLEY.
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
SHALLOW MSTR IN THE FORM OF LOW ST/SC CLOUDS WILL REMAIN TRAPPED
UNDER INC SUBSIDENCE INVERSION THIS MORNING...AS HIGH PRES BEGINS
TO BUILD INTO THE AREA IN THE WAKE OF DEPARTING UPPER TROF. WEAK
LLVL UPSLOPE WILL KEEP LOW MVFR/IFR CIGS AT BFD AND JST THE
LONGEST...WHILE DOWNSLOPE SHOULD HELP PROMOTE GRADUAL IMPROVEMENT
TO VFR CIGS EAST OF THE MTNS. SOME SCT LGT SHSN OR FLURRIES ARE
POSSIBLE ACRS THE WRN/CNTRL TAFS...BUT ANY VIS REDUCTIONS SHOULD
REMAIN AOA 5SM. FCST SOUNDINGS SUGGEST SOME PATCHY -FZDZ IS PSBL
OVER THE HIER TERRAIN AND BFD/JST HAVE BOTH REPORTED UP IN THE
LAST FEW HOURS...BUT WILL NOT MENTION IN TAF DUE TO ISOLD CVRG AND
LOW PROB. LOW CIGS WILL LKLY BE SLOW TO DISSIPATE TDY ESP ACRS THE
WRN TAFS...WITH WDSPRD VFR CONDS ANTICIPATED BY THIS EVE/TNT. SFC
WNDS WILL GRADUALLY WEAKEN AND BACK TO THE SOUTH BY THE END OF THE
PD.
OUTLOOK...
TUE-WED...MAINLY VFR...MVFR PSBL ON WED.
THU...VFR...DETERIORATING CONDITIONS PSBL LATER THURSDAY NIGHT.
FRI...MVFR/IFR WITH RAIN SHOWERS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...LA CORTE/GARTNER
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
321 AM EST MON JAN 7 2013
.SYNOPSIS...
HIGH PRESSURE WILL DOMINATE THE REGIONAL PATTERN THROUGH MID-
WEEK...BRINGING DRY AND TRANQUIL WEATHER CONDITIONS TO THE AREA.
A RELATIVELY MILD SOUTHWEST RETURN FLOW SHOULD ALLOW TEMPERATURES
TO MODERATE WELL-ABOVE SEASONAL CLIMATE NORMALS BY WEDNESDAY AND
THURSDAY. THE NEXT CHANCE FOR PRECIPITATION WILL COME BY THE END
OF THE WEEK...AS LOW PRESSURE MOVES INTO THE GREAT LAKES REGION.
&&
.NEAR TERM /UNTIL NOON TODAY/...
EXTENSIVE LOW-LEVEL MSTR/CLOUD COVER IN THE WAKE OF A NEBULOUS
SFC LOW MOVG AWAY FROM NRN NEW ENGLAND WILL PERSIST ACRS MUCH OF
WESTERN AND CENTRAL PA THIS MORNING...AS UPSLOPE WLY FLOW
CONTINUES TO PROVIDE SUFFICIENT /ALBEIT WEAK/ OROGRAPHIC LIFT OVER
THE ALLEGHENIES. REGIONAL RADAR MOSAIC ALSO INDICATES SOME LGT
PCPN ACRS THE WRN AND NRN MTNS...EITHER IN THE FORM OF -SN OR
PATCHY -FZDZ. THE RAP AND 4KM NAM FCST SOUNDINGS FAVOR -FZDZ
PROFILES THRU THE PRE DAWN HOURS AS MID-LVL MSTR IS STRIPPED AWAY.
THE CLOUD COVER AND STEADY 5-10KT WNW WIND WILL KEEP TEMPS IN
THE UPPER 20S TO MID 30S. LOW CLOUDS WILL LKLY BE SLOW TO ERODE
AFT SUNRISE ESP IN THE WRN MTNS AS LOW-LEVEL MSTR GETS TRAPPED
UNDER SFC RIDGE MOVG EWD FM THE OH VLY. HOWEVER ANTICIPATE SOME
BINOVC E OF THE MTNS.
&&
.SHORT TERM /NOON TODAY THROUGH 6 AM TUESDAY/...
LG SCALE SUBSIDENCE ASSOC WITH THE AFOREMENTIONED SFC HIGH AND
BACKING LLVL FLOW /TO THE SSW/ SHOULD AFFORD MORE PEAKS OF SUN AS
THE DAY WEARS ON. HIGHS SHOULD CLIMB A FEW DEGS ABOVE EARLY
JANUARY CLIMATE NORMALS...RANGING FROM THE LOW-MID 30S OVER THE
ALLEGHENIES TO THE LOW 40S OVER THE LWR SUSQ VLY. EXPECT MAINLY
CLR SKIES OVERNIGHT AS THE RIDGE MOVES OVER THE AREA...WITH LOWS
VARYING FROM THE UPPER TEENS TO MID 20S.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
MODERATELY AMPLIFIED SPLIT FLOW PATTERN WILL BRING SEVERAL
NORTHERN STREAM WAVES ACROSS THE NORTHEAST THIS PERIOD WHILE
A CLOSED UPR LOW IN THE SRN STREAM NOW OVER SRN CALIFORNIA
MEANDERS ACROSS MEXICO THEN ACROSS THE SOUTHERN U.S. BEFORE
POSSIBLY REACHING THE EASTERN PART OF THE COUNTRY NEXT WEEKEND.
NORTHERN STORM TRACK LOOKS TO GO MAINLY NORTH OF PA...KEEPING
THE PERIOD GENERALLY DRY WITH SFC HIGH PRESSURE DOMINATING PA.
IT SHOULD BECOME PROGRESSIVELY WARMER AS LOW LEVEL FLOW REMAINS
SWRLY.
ONE FROPA WED WILL PROVIDE A SLIGHT SLIGHT CHANCE OF SHOWERS MID
WEEK.
MOISTENING LOW LEVELS ON THE SWRLY FLOW COMBINED WITH THE ARRIVAL
OF THE SRN STREAM FORCING WILL BRING INCREASING CHANCES FOR
SHOWERS...MAINLY RAIN SHOWERS...LATER THURSDAY AND CONTINUING
THROUGH NEXT WEEKEND.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
SHALLOW MSTR IN THE FORM OF LOW ST/SC CLOUDS WILL REMAIN TRAPPED
UNDER INC SUBSIDENCE INVERSION THIS MORNING...AS HIGH PRES BEGINS
TO BUILD INTO THE AREA IN THE WAKE OF DEPARTING UPPER TROF. WEAK
LLVL UPSLOPE WILL KEEP LOW MVFR/IFR CIGS AT BFD AND JST THE
LONGEST...WHILE DOWNSLOPE SHOULD HELP PROMOTE GRADUAL IMPROVEMENT
TO VFR CIGS EAST OF THE MTNS. SOME SCT LGT SHSN OR FLURRIES ARE
POSSIBLE ACRS THE WRN/CNTRL TAFS...BUT ANY VIS REDUCTIONS SHOULD
REMAIN AOA 5SM. FCST SOUNDINGS SUGGEST SOME PATCHY -FZDZ IS PSBL
OVER THE HIER TERRAIN AND BFD/JST HAVE BOTH REPORTED UP IN THE
LAST FEW HOURS...BUT WILL NOT MENTION IN TAF DUE TO ISOLD CVRG AND
LOW PROB. LOW CIGS WILL LKLY BE SLOW TO DISSIPATE TDY ESP ACRS THE
WRN TAFS...WITH WDSPRD VFR CONDS ANTICIPATED BY THIS EVE/TNT. SFC
WNDS WILL GRADUALLY WEAKEN AND BACK TO THE SOUTH BY THE END OF THE
PD.
OUTLOOK...
TUE-WED...MAINLY VFR...MVFR PSBL ON WED.
THU...VFR...DETERIORATING CONDITIONS PSBL LATER THURSDAY NIGHT.
FRI...MVFR/IFR WITH RAIN SHOWERS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...LA CORTE/GARTNER
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
952 AM EST MON JAN 7 2013
.SYNOPSIS...
A WEDGE OF HIGH PRESSURE WILL BUILD INTO THE REGION AND PREVAIL
THROUGH TUESDAY...WHILE A COASTAL TROUGH OF LOW PRESSURE STRENGTHENS
OFFSHORE. A WEAK WARM FRONT WILL LIFT NORTH OF THE AREA WEDNESDAY
INTO THURSDAY AS A STORM SYSTEM PASSES WELL TO THE WEST. ATLANTIC
HIGH PRESSURE WILL THEN PREVAIL INTO EARLY NEXT WEEK BEFORE A COLD
FRONT APPROACHES FROM THE WEST.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
07/14Z SURFACE ANALYSIS SHOWED HIGH PRESSURE WEDGED IN SOLIDLY
ACROSS THE REGION. A THICK RIBBON OF JET ENHANCED CIRROSTRATUS IS
HOLDING FIRM...BUT RAP MOISTURE PROFILES SUGGEST IT WILL GRADUALLY
MIX OUT AS THE SUPPORTING UPPER JET SHIFTS FARTHER OFFSHORE.
EXPECT PARTLY CLOUDY SKIES TO GRADUALLY BECOME MOSTLY SUNNY LATER
TODAY...MAINLY ACROSS SOUTHEAST SOUTH CAROLINA AND POSSIBLY FAR
INTERIOR SOUTHEAST GEORGIA. THE ONSHORE FLOW WILL LIKELY SUPPORT A
SLIGHT INCREASE IN MOISTURE ACROSS THE SOUTH WHICH COULD
TRANSITION TO A SHALLOW CUMULUS FIELD. IN ADDITION...SOME MARINE
STRATOCUMULUS WILL LIKELY MOVE ONSHORE ACROSS PARTS OF THE GEORGIA
COAST. ALL OF THIS SHOULD PRODUCE PARTLY CLOUDY SKIES FOR MUCH OF
SOUTHEAST GEORGIA...ESPECIALLY SOUTH OF I-16. HIGHS FROM THE MID
50S NORTH TO AROUND 60 ALONG THE ALTAMAHA RIVER LOOK ON TRACK.
BEACH LOCATIONS WILL LIKELY ONLY TOP OUT IN THE LOWER 50S WITH
SOME SPOTS HOLDING IN THE UPPER 40S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
TONIGHT...ISENTROPIC LIFT WILL STRENGTHEN AS WILL A COASTAL TROUGH
OF LOW PRESSURE OFFSHORE. EXPECT CLOUD COVER TO INCREASE TOWARD
DAYBREAK FROM THE SOUTH AND EAST. THERE COULD BE SOME LIGHT RAIN
AS WELL...MAINLY NEAR THE COAST LATE. LOWS WILL LIKELY DROP
QUICKLY AT SUNSET AND THEN BECOME MAINLY STEADY OVERNIGHT AS THE
CLOUD COVER INCREASES...ESPECIALLY AROUND THE COAST. GOING FOR
LOWS IN THE MID 30S INLAND AND AROUND 40 CLOSER TO THE
COAST...WITH MID TO UPPER 40S LIKELY ALONG THE BEACHES.
TUESDAY...A WEDGE OF HIGH PRESSURE WILL BECOME ENTRENCHED OVER THE
FORECAST AREA AS A COASTAL TROUGH STRENGTHENS OFFSHORE. LOW LEVEL
MOISTURE TRAPPED BENEATH THE INVERSION AND DEVELOPING ISENTROPIC
ASCENT WILL RESULT IN CONSIDERABLE CLOUDINESS ACROSS THE AREA. THERE
IS A SLIGHT CHANCE OF RAIN ALONG THE GEORGIA COAST AND NEAR THE
ALTAMAHA RIVER ON TUESDAY WHERE LOW LEVEL MOISTURE AND CONVERGENCE
WILL BE GREATEST. THEN...EXPECT A SLIGHT CHANCE OF RAIN ACROSS THE
ENTIRE FORECAST AREA TUESDAY NIGHT AS MOISTURE DEEPENS AND
ISENTROPIC LIFT INCREASES. TEMPERATURES WILL STRUGGLE TO WARM WITHIN
THE WEDGE...WITH HIGHS RANGING FROM THE MID 50S IN THE NORTHWEST TO
THE LOWER 60S NEAR THE ALTAMAHA RIVER AND GEORGIA COAST. LOWS
TUESDAY NIGHT SHOULD BE IN THE MID TO UPPER 40S INLAND AND IN THE
LOWER 50S NEAR THE COAST.
WEDNESDAY...FORECAST CONFIDENCE IS EXTREMELY LOW AS THE MODELS ARE
PROVIDING MIXED SIGNALS WITH RESPECT TO THE WEDGE AND HOW QUICKLY IT
ERODES. THE MID AND UPPER LEVEL PATTERN WILL CERTAINLY FEATURE A
STRENGTHENING RIDGE OVER THE SOUTHEAST STATES. THERE IS SOME
INDICATION THAT A WEAK WARM FRONT MAY ACTUALLY TRY TO DEVELOP NEAR
THE AREA AND HOOK UP WITH THE COASTAL TROUGH. HOWEVER...WARM AIR
ADVECTION ALOFT WITH PLENTIFUL LOW LEVEL MOISTURE AND THE POTENTIAL
FOR ISOLATED TO SCATTERED SHOWERS WOULD ALL SUPPORT MAINTAINING THE
WEDGE...AT LEAST INLAND FROM THE COAST WHERE THE TROUGH MAY TRY TO
SHIFT ONSHORE. WHILE H8-H5 THICKNESS VALUES SUPPORT HIGHS WELL INTO
THE 70S...THIS IS NOT TAKING INTO ACCOUNT THE LOW LEVEL ENVIRONMENT.
HAVE THEREFORE OPTED TO LEAN HEAVILY ON THE COOLEST GUIDANCE AND
WILL KEEP HIGHS ONLY IN THE MID TO UPPER 60S ACROSS MOST OF THE
AREA. IF THE WEDGE BREAKS AND SOME CLEARING OCCURS...THEN THESE
TEMPERATURES COULD BE A GOOD 5-10 DEGREES TOO COOL.
THURSDAY...THE MID AND UPPER LEVEL PATTERN WILL BECOME MORE
AMPLIFIED AS THE RIDGE EXTENDS UP THE EASTERN SEABOARD WHILE A STORM
SYSTEM LIFTS NORTHEAST ACROSS THE MISSISSIPPI VALLEY. AS THIS
OCCURS...THE WARM FRONT WILL BEGIN TO LIFT NORTH OF THE AREA FINALLY
ALLOWING THE WEDGE TO ERODE. THERE WILL BE SCATTERED SHOWERS DURING
THE DAY...ESPECIALLY ACROSS SOUTHEAST SOUTH CAROLINA CLOSER TO THE
WARM FRONT. CONFIDENCE INCREASES THAT MUCH WARMER TEMPERATURES WILL
OCCUR...WITH HIGHS IN THE LOWER TO MID 70S ACROSS THE AREA AWAY FROM
THE COAST.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
A WEAKENING COLD FRONT TRAILING FROM A STORM SYSTEM LIFTING ACROSS
THE GREAT LAKES REGION COULD DROP INTO THE AREA ON FRIDAY...BUT A
LACK OF SUFFICIENT MOISTURE/FORCING SHOULD KEEP CONDITIONS
RAIN-FREE. ATLANTIC HIGH PRESSURE AND STRONG RIDGING ALOFT WILL THEN
RESULT IN DRY CONDITIONS THROUGH THE WEEKEND ALONG WITH A
CONTINUATION OF WELL ABOVE NORMAL TEMPERATURES. THE RIDGING WILL
BEGIN TO BREAK DOWN EARLY NEXT WEEK AS A COLD FRONT APPROACHES
FROM THE WEST.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS WILL PREVAIL THROUGH 12Z TUESDAY AT KCHS AND KSAV.
LOW-LEVEL MOISTURE WILL BE ON THE INCREASE AFTER MIDNIGHT BUT ANY
CEILINGS SHOULD REMAIN VFR.
EXTENDED AVIATION OUTLOOK...MVFR OR LOWER CIGS LIKELY TUESDAY THROUGH
LATE WEDNESDAY AS A WEDGE OF HIGH PRESSURE DEVELOPS OVER BOTH
TERMINALS. MVFR CIGS/VSBYS POSSIBLE ON THURSDAY WITH A WARM FRONT
LIFTING NORTH OVER THE AREA.
&&
.MARINE...
TODAY...POOR MARINE CONDITIONS WILL PERSIST ACROSS THE WATERS
TODAY WITH SMALL CRAFT ADVISORY CONDITIONS OCCURRING OVER THE
GEORGIA OFFSHORE WATERS. BUOY AND PILOT BOAT REPORTS INDICATE
WINDS ARE A SOLID 15-20 KT NEARSHORE AND ARE LIKELY CLOSER TO
20-25 KT BEYOND 20 NM OFF THE GEORGIA COAST. WILL HAVE TO WATCH
FOR A POTENTIAL PINCHING OF THE PRESSURE GRADIENT ALONG THE COAST
WHICH COULD TIP WINDS INTO ADVISORY THRESHOLDS OVER THE NEARSHORE
WATERS...BUT KEPT CONDITIONS BELOW FOR NOW.
TONIGHT...POOR MARINE CONDITIONS TONIGHT AS AN INLAND HIGH
PRESSURE WEDGE/OFFSHORE COASTAL TROUGH OF LOW PRESSURE PATTERN
SETS UP. THIS WILL KEEP BRISK NORTH/NORTHEAST WINDS IN
PLACE...ESPECIALLY TODAY. SEAS WILL BUILD AS WELL GIVEN THE STRONG
WINDS AND FAVORABLE FETCH AND WE SHOULD SEE SMALL CRAFT ADVISORY
CONDITIONS AT LEAST BEYOND 20 NM FROM SHORE.
TUESDAY THROUGH SATURDAY...WINDS/SEAS WILL REMAIN ELEVATED OVER THE
WATERS THROUGH TUESDAY AS THE PRESSURE GRADIENT REMAINS ENHANCED
BETWEEN BUILDING HIGH PRESSURE INLAND AND A STRENGTHENING COASTAL
TROUGH ALONG THE SOUTHEAST COAST. A SMALL CRAFT ADVISORY WILL REMAIN
IN EFFECT FOR THE OUTER GEORGIA WATERS THROUGH TUESDAY MORNING AS A
RESULT. THE TROUGH WILL PERSIST THROUGH WEDNESDAY THEN SLOWLY MOVE
NORTH OF THE AREA AS A WARM FRONT ON THURSDAY. ALTHOUGH WINDS WILL
DIMINISH ACROSS THE ENTIRE MARINE AREA BY TUESDAY NIGHT THERE COULD
BE PERIODS OF ENHANCED WINDS THROUGH MID WEEK DEPENDING ON WHERE THE
BEST GRADIENT SETS UP...MOST LIKELY ACROSS THE CHARLESTON NEARSHORE
WATERS. A SOUTHERLY FLOW WILL THEN DEVELOP LATE THIS WEEK INTO THE
WEEKEND AS ATLANTIC HIGH PRESSURE BUILDS INTO THE REGION. A RISK OF
SEA FOG REMAINS OVER THE COOL NEARSHORE WATERS LATE WEEK...AS A
WARMER AND MORE HUMID AIRMASS MOVES INTO THE AREA.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST TUESDAY FOR AMZ374.
&&
$$
ST
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
641 AM EST MON JAN 7 2013
.SYNOPSIS...
HIGH PRESSURE WILL DOMINATE THE REGIONAL PATTERN THROUGH MID-
WEEK...BRINGING DRY AND TRANQUIL WEATHER CONDITIONS TO THE AREA.
A RELATIVELY MILD SOUTHWEST RETURN FLOW SHOULD ALLOW TEMPERATURES
TO MODERATE WELL-ABOVE SEASONAL CLIMATE NORMALS BY WEDNESDAY AND
THURSDAY. THE NEXT CHANCE FOR PRECIPITATION WILL COME BY THE END
OF THE WEEK...AS LOW PRESSURE MOVES INTO THE GREAT LAKES REGION.
&&
.NEAR TERM /UNTIL NOON TODAY/...
12Z UPDATE...
VERY MINOR CHANGES MADE TO SIG WX ELEMENTS WITH THE EARLY MORNING
UPDATE. ISSUED SPS TO COVER PATCHY -FZDZ AND POTNL ICY ROAD
THREAT OVER THE ALLEGHENIES. OTHERWISE...STILL LIKE THE IDEA OF
SLOW...GRADUAL CLEARING WITH PLENTY OF RESIDUAL LLVL MSTR/LOW
CLOUDS STILL COVERING NEARLY THE ENTIRE CWA PER IR SATL LOOP. TEMPS
HAVE REMAINED RELATIVELY WARM OVERNIGHT...AND WITH THE AFOREMENTIONED
CLOUDS NOT EXPECTING A HUGE REBOUND THIS AFTN.
PREVIOUS DISCUSSION FROM 321 AM...
EXTENSIVE LOW-LEVEL MSTR/CLOUD COVER IN THE WAKE OF A NEBULOUS
SFC LOW MOVG AWAY FROM NRN NEW ENGLAND WILL PERSIST ACRS MUCH OF
WESTERN AND CENTRAL PA THIS MORNING...AS UPSLOPE WLY FLOW
CONTINUES TO PROVIDE SUFFICIENT /ALBEIT WEAK/ OROGRAPHIC LIFT OVER
THE ALLEGHENIES. REGIONAL RADAR MOSAIC ALSO INDICATES SOME LGT
PCPN ACRS THE WRN AND NRN MTNS...EITHER IN THE FORM OF -SN OR
PATCHY -FZDZ. THE RAP AND 4KM NAM FCST SOUNDINGS FAVOR -FZDZ
PROFILES THRU THE PRE DAWN HOURS AS MID-LVL MSTR IS STRIPPED AWAY.
THE CLOUD COVER AND STEADY 5-10KT WNW WIND WILL KEEP TEMPS IN
THE UPPER 20S TO MID 30S. LOW CLOUDS WILL LKLY BE SLOW TO ERODE
AFT SUNRISE ESP IN THE WRN MTNS AS LOW-LEVEL MSTR GETS TRAPPED
UNDER SFC RIDGE MOVG EWD FM THE OH VLY. HOWEVER ANTICIPATE SOME
BINOVC E OF THE MTNS.
&&
.SHORT TERM /NOON TODAY THROUGH 6 AM TUESDAY/...
LG SCALE SUBSIDENCE ASSOC WITH THE AFOREMENTIONED SFC HIGH AND
BACKING LLVL FLOW /TO THE SSW/ SHOULD AFFORD MORE PEAKS OF SUN AS
THE DAY WEARS ON. HIGHS SHOULD CLIMB A FEW DEGS ABOVE EARLY
JANUARY CLIMATE NORMALS...RANGING FROM THE LOW-MID 30S OVER THE
ALLEGHENIES TO THE LOW 40S OVER THE LWR SUSQ VLY. EXPECT MAINLY
CLR SKIES OVERNIGHT AS THE RIDGE MOVES OVER THE AREA...WITH LOWS
VARYING FROM THE UPPER TEENS TO MID 20S.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
MODERATELY AMPLIFIED SPLIT FLOW PATTERN WILL PREVAIL THROUGH THE
UPCOMING WORKWEEK...WITH THE NORTHERN STREAM TAPPING MAINLY PACIFIC
AIR THROUGH THE PERIOD.
EARLY IN THE PERIOD...A RIDGE OF SFC HIGH PRESSURE WILL EXTEND FROM
THE WESTERN ATLANTIC TO THE VIRGINIAS...WITH A DEVELOPING SWRLY FLOW
AND ABUNDANT SUNSHINE TEAMING UP TO BOOST TEMPS SOME 7-10F ABOVE
NORMAL. POPS WILL BE ZERO FOR THE DAY TUESDAY.
FOR TUESDAY NIGHT AND WEDNESDAY...A WELL DEFINED AND FAST MOVING NRN
STREAM SHORTWAVE WILL TRACK FROM THE UPPER GLAKES...TO THE NERN U.S.
BY 00Z THUR. BROAD...UPPER DIFFLUENT FLOW BETWEEN TWO DISTINCT 300
MB JET MAXES IN EXCESS OF 100 KTS AND A BRIEF PUSH OF NEAR 0.50 INCH
PWATS WILL BRING JUST A FEW TO SVRL HOUR PERIOD LAYERED BROKEN CLOUD
COVER AND PERHAPS A FEW SPRINKLES...OR BRIEF LIGHT RAIN/SNOW SHOWERS
ACROSS THE WRN MTNS DURING THE EARLY TO MID MORNING HOURS WEDNESDAY
/INVOF OF A MOISTURE CHALLENGED WARM FRONT/.
FAIRLY STRONG SUBSIDENCE IN THE WARM SECTOR WILL FOLLOW FOR THE
MIDDAY AND AFTERNOON HOURS WEDNESDAY...BENEATH THE THERMALLY
INDIRECT RIGHT EXIT REGION OF A 150 KT UPPER JET STREAK CROSSING NEW
YORK STATE. PARTLY TO MOSTLY SUNNY SKIES FOR WEDNESDAY AFTERNOON
WILL BOOST TEMPS FURTHER /BY ABOUT 5 DEG F HIGHER THAN TUESDAY/.
HIGHS WED AFTN WILL VARY FROM THE LOWER 40S ACROSS THE NW MTNS TO
THE LOWER 50S IN SOME OF THE SOUTHERN VALLEYS. THESE READINGS WILL
BE ROUGHLY 10-15F ABOVE NORMAL...WITH THE GREATER DEPARTURES
OCCURRING ACROSS THE MTNS.
WESTERLY WINDS WILL QUICKLY INCREASE WEDNESDAY MORNING...AND WILL
LIKELY GUST BETWEEN 30-35 MPH AT TIMES IN THE AFTERNOON /ESPECIALLY
ACROSS THE HIGHER TERRAIN OF THE NORTH AND WEST/.
A BRIEF SHOT OF SLIGHTLY COOLER AIR FOLLOWS THE EXIT OF THIS NRN
STREAM WAVE WEDNESDAY NIGHT. AS WINDS DIMINISH QUICKLY IN THE
EVENING AND SKIES STAY MAINLY CLEAR...TEMPS WILL FALL TO AROUND 20F
ACROSS THE NRN MTNS /WHERE THE DEEPEST SNOW COVER WILL REMAIN/ TO
NEAR 30F IN THE SOUTHEAST.
SFC HIGH WILL BE CENTERED ACROSS WRN PENN TO START THE DAY
THURSDAY...AND WILL SLIDE EAST ACROSS THE COMMONWEALTH DURING THE
AFTERNOON. A SLOW MOVING...CLOSED UPPER LOW IMPACTING FAR WEST TEXAS
EARLY IN THE WEEK WILL LIFT NE WED AND THURSDAY...AS AN OPENING WAVE
IN THE AMPLIFYING SWRLY FLOW ACROSS THE MIDWEST AND GLAKES REGION.
INCREASING DEEP-LAYER WARM ADVECTION AHEAD OF THIS SYSTEM LATE
THURSDAY INTO EARLY FRIDAY WILL BRING THICKENING CLOUDS AND HIGH CHC
TO LOW LIKELY POPS FOR RAIN SHOWERS. THE VERY DRY LLVLS COULD COOL
TO JUST BELOW FREEZING AS THE PRECIP SPREADS NE THURSDAY
NIGHT...POSSIBLY LEADING TO SOME SPOTTY LIGHT MIXED PRECIP...MAINLY
TO THE NORTH AND EAST OF KIPT WHERE A FEW HOURS OF CLEARING ARE
POSSIBLE DURING THE EVENING HOURS.
IN THE WAKE OF THIS MINOR PRECIP EVENT AND SOME ADDITIONAL
SNOWMELT/RUNOFF...TEMPS WILL SLOWLY RISE TO EVEN GREATER DEPARTURES
FROM NORMAL AS A VERY ANOMALOUS UPPER RIDGE OF PLUS 2-3 ST
DEVIATIONS AMPLIFIES ACROSS THE GLAKES...EAST THROUGH THE NE U.S.
AND SERN CANADA.
HIGH TEMPS BY SATURDAY COULD BE EASILY 15-20F ABOVE NORMAL ACROSS
THE CENTRAL AND SRN PORTIONS OF THE CWA...WITH MAXES RANGING FROM
THE MID 40S IN THE NORTH...TO LOWER AND MID 50S THROUGHOUT SOUTHERN
PENN.
INCREASING CHCS FOR RAIN WILL DEVELOP FOR THE SECOND HALF OF THE
WEEKEND AS A SLOW MOVING COLD FRONT PRESSES EAST TWD THE REGION AND
ONE OR MORE WAVES OF SFC LOW PRESSURE RIDE NEWD ALONG IT.
A BIG PATTERN CHANGE IS LIKELY THE FOLLOWING WEEK AS SIGNIFICANT
RIDGING DEVELOPS ACROSS THE EASTERN PACIFIC AND ALLOWS A LARGE AREA
OF ARCTIC AIR TO SURGE SE INTO THE NRN ROCKIES AND UPPER MID VALLEY
MONDAY AND TUESDAY...WITH COOLER AIR OOZING INTO THE MIDDLE ATLANTIC
AND LOWER GLAKES REGION.
THE NEXT POTENTIAL WINTRY /OR SIGNIFICANT RAIN EVENT/ WILL LIKELY BE
NEXT TUESDAY INTO WEDNESDAY AS THE NRN AND SRN STREAM PHASES INTO A
HIGH AMPLITUDE TROUGH FROM THE UPPER GLAKES...SWD TO THE LOWER MISS
VALLEY.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
SHALLOW MSTR IN THE FORM OF LOW ST/SC CLOUDS WILL REMAIN TRAPPED
UNDER SUBSIDENCE INVERSION THRU THIS MORNING...AS HIGH PRES
BEGINS TO BUILD INTO THE AREA IN THE WAKE OF DEPARTING UPPER TROF.
WEAK LLVL UPSLOPE WILL KEEP IFR TO LOW MVFR CIGS AT BFD AND JST
THRU 16-18Z...WHILE DOWNSLOPE WNW FLOW SHOULD HELP PROMOTE GRADUAL
IMPROVEMENT/VFR CIGS EAST OF THE MTNS. FCST SOUNDINGS SUPPORT SOME
PATCHY -FZDZ AND ICING CONCERNS OVER THE HIER TERRAIN INVOF
BFD/JST THRU 13Z. LOW CIGS WILL BE SLOW TO DISSIPATE TDY ESP ACRS
THE WRN TAFS WITH WDSPRD VFR CONDS ANTICIPATED /ALONG WITH CLEARING/
BY THIS EVE AND TNT. SFC WNDS WILL GRADUALLY WEAKEN AND BACK TO
THE SOUTH BY THE END OF THE PD/12Z TUE.
OUTLOOK...
TUE-THUR...MAINLY VFR...MVFR CIGS PSBL N/W WED-THUR.
THUR NGT-FRI...BCMG MVFR/IFR WITH RAIN SHOWERS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...LA CORTE/GARTNER
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
535 AM EST MON JAN 7 2013
.SYNOPSIS...
HIGH PRESSURE WILL DOMINATE THE REGIONAL PATTERN THROUGH MID-
WEEK...BRINGING DRY AND TRANQUIL WEATHER CONDITIONS TO THE AREA.
A RELATIVELY MILD SOUTHWEST RETURN FLOW SHOULD ALLOW TEMPERATURES
TO MODERATE WELL-ABOVE SEASONAL CLIMATE NORMALS BY WEDNESDAY AND
THURSDAY. THE NEXT CHANCE FOR PRECIPITATION WILL COME BY THE END
OF THE WEEK...AS LOW PRESSURE MOVES INTO THE GREAT LAKES REGION.
&&
.NEAR TERM /UNTIL NOON TODAY/...
EXTENSIVE LOW-LEVEL MSTR/CLOUD COVER IN THE WAKE OF A NEBULOUS
SFC LOW MOVG AWAY FROM NRN NEW ENGLAND WILL PERSIST ACRS MUCH OF
WESTERN AND CENTRAL PA THIS MORNING...AS UPSLOPE WLY FLOW
CONTINUES TO PROVIDE SUFFICIENT /ALBEIT WEAK/ OROGRAPHIC LIFT OVER
THE ALLEGHENIES. REGIONAL RADAR MOSAIC ALSO INDICATES SOME LGT
PCPN ACRS THE WRN AND NRN MTNS...EITHER IN THE FORM OF -SN OR
PATCHY -FZDZ. THE RAP AND 4KM NAM FCST SOUNDINGS FAVOR -FZDZ
PROFILES THRU THE PRE DAWN HOURS AS MID-LVL MSTR IS STRIPPED AWAY.
THE CLOUD COVER AND STEADY 5-10KT WNW WIND WILL KEEP TEMPS IN
THE UPPER 20S TO MID 30S. LOW CLOUDS WILL LKLY BE SLOW TO ERODE
AFT SUNRISE ESP IN THE WRN MTNS AS LOW-LEVEL MSTR GETS TRAPPED
UNDER SFC RIDGE MOVG EWD FM THE OH VLY. HOWEVER ANTICIPATE SOME
BINOVC E OF THE MTNS.
&&
.SHORT TERM /NOON TODAY THROUGH 6 AM TUESDAY/...
LG SCALE SUBSIDENCE ASSOC WITH THE AFOREMENTIONED SFC HIGH AND
BACKING LLVL FLOW /TO THE SSW/ SHOULD AFFORD MORE PEAKS OF SUN AS
THE DAY WEARS ON. HIGHS SHOULD CLIMB A FEW DEGS ABOVE EARLY
JANUARY CLIMATE NORMALS...RANGING FROM THE LOW-MID 30S OVER THE
ALLEGHENIES TO THE LOW 40S OVER THE LWR SUSQ VLY. EXPECT MAINLY
CLR SKIES OVERNIGHT AS THE RIDGE MOVES OVER THE AREA...WITH LOWS
VARYING FROM THE UPPER TEENS TO MID 20S.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
MODERATELY AMPLIFIED SPLIT FLOW PATTERN WILL PREVAIL THROUGH THE
UPCOMING WORKWEEK...WITH THE NORTHERN STREAM TAPPING MAINLY PACIFIC
AIR THROUGH THE PERIOD.
EARLY IN THE PERIOD...A RIDGE OF SFC HIGH PRESSURE WILL EXTEND FROM
THE WESTERN ATLANTIC TO THE VIRGINIAS...WITH A DEVELOPING SWRLY FLOW
AND ABUNDANT SUNSHINE TEAMING UP TO BOOST TEMPS SOME 7-10F ABOVE
NORMAL. POPS WILL BE ZERO FOR THE DAY TUESDAY.
FOR TUESDAY NIGHT AND WEDNESDAY...A WELL DEFINED AND FAST MOVING NRN
STREAM SHORTWAVE WILL TRACK FROM THE UPPER GLAKES...TO THE NERN U.S.
BY 00Z THUR. BROAD...UPPER DIFFLUENT FLOW BETWEEN TWO DISTINCT 300
MB JET MAXES IN EXCESS OF 100 KTS AND A BRIEF PUSH OF NEAR 0.50 INCH
PWATS WILL BRING JUST A FEW TO SVRL HOUR PERIOD LAYERED BROKEN CLOUD
COVER AND PERHAPS A FEW SPRINKLES...OR BRIEF LIGHT RAIN/SNOW SHOWERS
ACROSS THE WRN MTNS DURING THE EARLY TO MID MORNING HOURS WEDNESDAY
/INVOF OF A MOISTURE CHALLENGED WARM FRONT/.
FAIRLY STRONG SUBSIDENCE IN THE WARM SECTOR WILL FOLLOW FOR THE
MIDDAY AND AFTERNOON HOURS WEDNESDAY...BENEATH THE THERMALLY
INDIRECT RIGHT EXIT REGION OF A 150 KT UPPER JET STREAK CROSSING NEW
YORK STATE. PARTLY TO MOSTLY SUNNY SKIES FOR WEDNESDAY AFTERNOON
WILL BOOST TEMPS FURTHER /BY ABOUT 5 DEG F HIGHER THAN TUESDAY/.
HIGHS WED AFTN WILL VARY FROM THE LOWER 40S ACROSS THE NW MTNS TO
THE LOWER 50S IN SOME OF THE SOUTHERN VALLEYS. THESE READINGS WILL
BE ROUGHLY 10-15F ABOVE NORMAL...WITH THE GREATER DEPARTURES
OCCURRING ACROSS THE MTNS.
WESTERLY WINDS WILL QUICKLY INCREASE WEDNESDAY MORNING...AND WILL
LIKELY GUST BETWEEN 30-35 MPH AT TIMES IN THE AFTERNOON /ESPECIALLY
ACROSS THE HIGHER TERRAIN OF THE NORTH AND WEST/.
A BRIEF SHOT OF SLIGHTLY COOLER AIR FOLLOWS THE EXIT OF THIS NRN
STREAM WAVE WEDNESDAY NIGHT. AS WINDS DIMINISH QUICKLY IN THE
EVENING AND SKIES STAY MAINLY CLEAR...TEMPS WILL FALL TO AROUND 20F
ACROSS THE NRN MTNS /WHERE THE DEEPEST SNOW COVER WILL REMAIN/ TO
NEAR 30F IN THE SOUTHEAST.
SFC HIGH WILL BE CENTERED ACROSS WRN PENN TO START THE DAY
THURSDAY...AND WILL SLIDE EAST ACROSS THE COMMONWEALTH DURING THE
AFTERNOON. A SLOW MOVING...CLOSED UPPER LOW IMPACTING FAR WEST TEXAS
EARLY IN THE WEEK WILL LIFT NE WED AND THURSDAY...AS AN OPENING WAVE
IN THE AMPLIFYING SWRLY FLOW ACROSS THE MIDWEST AND GLAKES REGION.
INCREASING DEEP-LAYER WARM ADVECTION AHEAD OF THIS SYSTEM LATE
THURSDAY INTO EARLY FRIDAY WILL BRING THICKENING CLOUDS AND HIGH CHC
TO LOW LIKELY POPS FOR RAIN SHOWERS. THE VERY DRY LLVLS COULD COOL
TO JUST BELOW FREEZING AS THE PRECIP SPREADS NE THURSDAY
NIGHT...POSSIBLY LEADING TO SOME SPOTTY LIGHT MIXED PRECIP...MAINLY
TO THE NORTH AND EAST OF KIPT WHERE A FEW HOURS OF CLEARING ARE
POSSIBLE DURING THE EVENING HOURS.
IN THE WAKE OF THIS MINOR PRECIP EVENT AND SOME ADDITIONAL
SNOWMELT/RUNOFF...TEMPS WILL SLOWLY RISE TO EVEN GREATER DEPARTURES
FROM NORMAL AS A VERY ANOMALOUS UPPER RIDGE OF PLUS 2-3 ST
DEVIATIONS AMPLIFIES ACROSS THE GLAKES...EAST THROUGH THE NE U.S.
AND SERN CANADA.
HIGH TEMPS BY SATURDAY COULD BE EASILY 15-20F ABOVE NORMAL ACROSS
THE CENTRAL AND SRN PORTIONS OF THE CWA...WITH MAXES RANGING FROM
THE MID 40S IN THE NORTH...TO LOWER AND MID 50S THROUGHOUT SOUTHERN
PENN.
INCREASING CHCS FOR RAIN WILL DEVELOP FOR THE SECOND HALF OF THE
WEEKEND AS A SLOW MOVING COLD FRONT PRESSES EAST TWD THE REGION AND
ONE OR MORE WAVES OF SFC LOW PRESSURE RIDE NEWD ALONG IT.
A BIG PATTERN CHANGE IS LIKELY THE FOLLOWING WEEK AS SIGNIFICANT
RIDGING DEVELOPS ACROSS THE EASTERN PACIFIC AND ALLOWS A LARGE AREA
OF ARCTIC AIR TO SURGE SE INTO THE NRN ROCKIES AND UPPER MID VALLEY
MONDAY AND TUESDAY...WITH COOLER AIR OOZING INTO THE MIDDLE ATLANTIC
AND LOWER GLAKES REGION.
THE NEXT POTENTIAL WINTRY /OR SIGNIFICANT RAIN EVENT/ WILL LIKELY BE
NEXT TUESDAY INTO WEDNESDAY AS THE NRN AND SRN STREAM PHASES INTO A
HIGH AMPLITUDE TROUGH FROM THE UPPER GLAKES...SWD TO THE LOWER MISS
VALLEY.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
07/09Z UPDATE...VRY MINOR CHANGES TO 07/06Z TAFS AS FCST IS
GENERALLY IN CATG. XPCT IFR TO CONT AT BFD/JST THRU 15Z...WITH
MVFR CIGS AT UNV/AOO AND VFR CIGS AT THE ERN AIRFIELDS IN ZNY
SECTOR.
PREVIOUS DISCUSSION 07/06Z...
SHALLOW MSTR IN THE FORM OF LOW ST/SC CLOUDS WILL REMAIN TRAPPED
UNDER INC SUBSIDENCE INVERSION THIS MORNING...AS HIGH PRES BEGINS
TO BUILD INTO THE AREA IN THE WAKE OF DEPARTING UPPER TROF. WEAK
LLVL UPSLOPE WILL KEEP LOW MVFR/IFR CIGS AT BFD AND JST THE
LONGEST...WHILE DOWNSLOPE SHOULD HELP PROMOTE GRADUAL IMPROVEMENT
TO VFR CIGS EAST OF THE MTNS. SOME SCT LGT SHSN OR FLURRIES ARE
POSSIBLE ACRS THE WRN/CNTRL TAFS...BUT ANY VIS REDUCTIONS SHOULD
REMAIN AOA 5SM. FCST SOUNDINGS SUGGEST SOME PATCHY -FZDZ IS PSBL
OVER THE HIER TERRAIN AND BFD/JST HAVE BOTH REPORTED UP IN THE
LAST FEW HOURS...BUT WILL NOT MENTION IN TAF DUE TO ISOLD CVRG AND
LOW PROB. LOW CIGS WILL LKLY BE SLOW TO DISSIPATE TDY ESP ACRS THE
WRN TAFS...WITH WDSPRD VFR CONDS ANTICIPATED BY THIS EVE/TNT. SFC
WNDS WILL GRADUALLY WEAKEN AND BACK TO THE SOUTH BY THE END OF THE
PD.
OUTLOOK...
TUE-THUR...MAINLY VFR...MVFR CIGS PSBL N/W WED-THUR.
THUR NGT-FRI...BCMG MVFR/IFR WITH RAIN SHOWERS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...LA CORTE/GARTNER
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
949 AM MST MON JAN 7 2013
.UPDATE...
&&
.SHORT TERM...CURRENT FORECASTS LOOK REASONABLE. CLOSED UPPER LOW
CURRENTLY OVER SOUTHERN CALIFORNIA WITH WEAK FLOW ALOFT ACROSS
COLORADO. HIGH CLOUDS OVER AREA CONTINUE TO THIN WHICH WILL ALLOW
FOR ABUNDANT SUNSHINE AND HELP WITH WARMUP DESPITE SLIGHTLY COOLER
AIRMASS OVER REGION. MAY NEED TO INCREASE TEMPS A BIT ACROSS THE
PLAINS...BASED ON CURRENT CONDITIONS.
.AVIATION...CURRENT TAF TRENDS STILL ON TRACK. LATEST RAP AND HRRR
INDICATE THE DEVELOPMENT OF A DENVER CYCLONE DURING THE AFTERNOON
WITH SOUTHEAST WINDS AT DEN AND APA...AND WEST TO NORTHWEST WINDS
AT BJC. SPEEDS STILL EXPECTED TO STAY BELOW 12 KTS. DRAINAGE
PATTERN TO DEVELOP THIS EVENING. VFR TO CONTINUE.
&&
.PREV DISCUSSION... /ISSUED 406 AM MST MON JAN 7 2013/
SHORT TERM...CLOSED UPPER LEVEL LOW OVER SOUTHERN CALIFORNIA WILL
DIVE SOUTHEAST INTO MEXICO TODAY. THE MAIN JET STREAM WILL BE OVER
THE NORTHERN ROCKIES AND LEAVE COLORADO IN BETWEEN THESE FEATURES
WHICH WILL RESULT IN A WEAK FLOW ALOFT. TEMPERATURES ARE RUNNING
MUCH WARMER THIS MORNING THAN THE PAST FEW DUE TO THE CLOUDS OVER
THE AREA. IN ADDITION TO THE HIGH CLOUDS...WEST WINDS OVER AND
NEAR THE FOOTHILLS ARE ALSO HELPING KEEP TEMPERATURES UP. THE HIGH
CLOUDS WILL MOVE OFF TO THE EAST THIS MORNING. EVEN THOUGH THE
AIRMASS ABOVE COLORADO WILL BE SLIGHTLY COOLER TODAY...A MUCH
WARMER START TO THE DAY AND SUNSHINE WILL ALLOW MOST LOCATIONS TO
GET CLOSE OR POSSIBLY A LITTLE WARMER THAN YESTERDAY.
THE JET STREAM OVER THE NORTHERN ROCKIES WILL SINK SOUTH SOME
TONIGHT AS A SHORT WAVE PASSES TO THE NORTH OF COLORADO. WILL SEE AN
INCREASE IN MID AND HIGH CLOUDS TONIGHT AS THIS OCCURS. THE CLOUD
COVER WILL BRING ANOTHER MILD NIGHT. MAY BE ABLE TO SQUEEZE OUT A
COUPLE OF WEAK SNOW SHOWERS OVER THE MOUNTAINS OF NORTH CENTRAL
COLORADO. IF ANY SNOW DEVELOPS...IT WILL BE LIGHT WITH ACCUMULATION
LESS THAN AN INCH.
LONG TERM...ABOVE AVERAGE TEMPERATURES AND AN ALMOST ZERO
CHANCE FOR PRECIP STILL PROGGED FOR THE TUESDAY-THURSDAY TIME
PERIOD. BROAD UPPER RIDGE SLOWLY MIGRATES OVER THE REGION DURING
THE 3-DAY PERIOD. MODERATE NORTHWEST FLOW ALOFT ON TUESDAY WILL
TRANSITION TO A LIGHTER WEST-SOUTHWEST FLOW ON WEDNESDAY AND A
MORE SOUTHWESTERLY FLOW OF SIMILAR SPEED ON THURSDAY. A CLOSED
UPPER LOW PASSING TO OUR SOUTHEAST ON THURSDAY COULD BRUSH
SOUTHEASTERN PORTIONS OF THE FORECAST AREA WITH A SHIELD OF
MID/HIGH LEVEL CLOUDS DURING THE MORNING HOURS...DON/T SEE ANY
PRECIP WITH THIS MOISTURE. SEE SMALL DAY-TO-DAY CHANGE IN
TEMPERATURE DURING THE PERIOD WITH TUESDAY THE COOLER OF THE 3
DAYS AND EITHER WEDNESDAY OR THURSDAY THE WARMEST DAY. ALL DEPENDS
ON HOW MUCH CLOUD COVER WE SEE ON THURSDAY.
ATTENTION NEXT TURNS TO THE DEEP UPPER TROUGH AND STRONG SFC COLD
FRONT SWINGING OUT OF THE PACIFIC NORTHWEST MIDWEEK. 00Z AND 06Z
RUNS OF THE OPERATIONAL GFS AND ECMWF APPEAR TO CLUSTER AROUND A
SIMILAR SOLUTION FOR WEDNESDAY AND THURSDAY...BUT THEN DIVERGE WITH
THE GFS BECOMING STRONGER...WETTER AND MORE PROGRESSIVE WITH THE
TROUGH THAN THE EC. MOISTURE AND WIND FIELDS OF THE 00Z/06Z CANADIAN
GEM APPEAR SIMILAR TO THOSE OF THE ECMWF...AND SIMILAR TO THE HEIGHT
AND TEMP FIELDS OF THE GFS. THE GFS INDICATES SFC CYCLOGENSIS IN
SERN COLORADO ON FRIDAY WITH A SFC COLD FRONT BACKING INTO NERN
COLORADO THAT MORNING AS A LARGE UPPER LEVEL TROUGH CARVES OUT OVER
THE ROCKY MTN REGION. THE EC AND GEM DELAY THE ARRIVAL OF THE COLD
FRONT UNTIL FRIDAY AFTERNOON AND THE REALLY COLD AIR UNTIL WELL
AFTER DARK. THIS WOULD EXPLAIN THE WIDE RANGE IN MAX TEMPERATURES
OFFERED BY THE VARIOUS MOS GUIDANCE. FOR INSTANCE...GFS MOS GIVES A
MAX TEMP OF 30 AT DENVER ON FRI AND THE ECMWF A MUCH WARMER HIGH OF
58. FOR SATURDAY...GFS GIVES A HIGH AT DENVER OF ONLY 20...AND THE
EC A HIGH OF 38. REALLY COULD GO EITHER WAY AT THIS POINT...BUT
SURROUNDING WFOS HAVE SIDED WITH THE COLDER GFS. WILL DO THE
SAME...AT LEAST FOR NOW.
THERE/S ALSO A SIGNIFICANT AMOUNT OF UNCERTAINTY WITH REGARD TO OUR
PRECIPITATION CHANCES WITH THIS SYSTEM. GFS WOULD HAVE US BELIEVE WE
COULD SEE SEVERAL INCHES OF SNOW BOTH MTNS AND PLAINS STARTING
FRIDAY AFTERNOON AND ENDING SATURDAY MORNING WITH SEVERAL HOURS OF
DEEP CYCLONIC UPSLOPE FLOW. WHEREAS EC AND GEM INDICATE LESS
OROGRAPHIC/SYNOPTIC SCALE FORCING AS WELL AS LESS LOW-LEVEL
MOISTURE. THEIR SNOW ACCUM GRIDS INDICATE ONLY SCATTERED AREAS OF
LIGHT SNOW ACCUMULATION BY SATURDAY MORNING. BOTTOM LINE...WITH SO
MUCH UNCERTAINTY IN FORECAST BEYOND THURSDAY NIGHT...NOT PLANNING TO
MAKE MANY CHANGES TO CURRENT FCST PACKAGE DURING THIS PERIOD.
AVIATION...VFR CONDITIONS WILL PREVAIL THE NEXT 24 HOURS WITH
HIGH CLOUDS THIS MORNING AND THEN AGAIN TONIGHT.
AT KDEN AND KAPA...NORMAL SOUTHERLY DRAINAGE WINDS WILL BECOME LIGHT
AND VARIABLE AFTER SUNRISE. BY AFTERNOON...EXPECTING SOME SORT OF
WEAK EASTERLY COMPONENT TO THE WIND...LIKELY EAST TO SOUTHEAST.
WINDS SPEEDS ARE EXPECTED TO STAY UNDER 12 KNOTS.
AT KBJC...WESTERLY WINDS WILL PREVAIL THROUGH EARLY MORNING. MAY SEE
WIND GUSTS AS HIGH AS 20 KNOTS AS WINDS ROLL OFF THE FOOTHILLS.
WEAKER WINDS ARE EXPECTED DURING THE DAY. THEN TONIGHT...WESTERLY
WINDS MAY INCREASE WITH GUSTS TO 25 KNOTS OCCASIONALLY OCCURRING.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...D-L
LONG TERM....BAKER
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
234 PM CST MON JAN 7 2013
.SHORT TERM...TONIGHT THROUGH THURSDAY.
MAIN FORECAST CONCERNS WILL DEAL WITH TEMPERATURES AND TIMING OF
SYSTEM MOVING OUT OF THE SOUTHERN PLAINS WEDNESDAY NIGHT INTO
THURSDAY.
DESPITE THICK CIRRUS LAYER ACROSS PARTS OF THE AREA AND LIGHT
SURFACE WINDS ALONG A WEAK TROUGH INTO EAST CENTRAL NEBRASKA...
TEMPERATURES HAVE MANAGED TO CLIMB INTO THE MID AND UPPER 30S IN
SNOW COVERED PORTION OF THE CWA WITH MID 40S TO LOWER 50S IN SNOW
FREE PARTS OF SOUTHEAST NEBRASKA AND SOUTHWEST IOWA THIS AFTERNOON.
INITIAL CONCERN FOR TONIGHT WILL BE POTENTIAL FOG DEVELOPMENT IN
THE SNOW AREAS WHERE SOME MELTING TODAY HAS ADDED MOISTURE TO THE
BOUNDARY LAYER. SHORT RANGE RAP HINTS AT DEVELOPMENT AFTER 06Z IN
AREA WHERE MENTION OF PATCHY FOG IS ALREADY IN CURRENT FORECAST.
FOR TUESDAY AND WEDNESDAY QUESTION WILL BE HOW WARM WILL
TEMPERATURES BE ABLE TO REACH. BASED ON TODAYS READINGS CLIMBING
TO AROUND 50 IN THE SOUTHEAST PART OF THE CWA...HAVE WENT A
WARMER THAN GUIDANCE IN THE SNOW FREE AREAS WITH SNOW FIELD STILL
EXPECTED TO KEEP TEMPERATURES TO THE NORTH CLOSE TO GUIDANCE.
TIMING ISSUES AMONG THE MODELS STILL IN PLAY FOR WEDNESDAY NIGHT
AND THURSDAY WITH NAM THE FASTEST AND LEAST REGARDED AT THIS TIME
FRAME. GFS AND EURO HAVE BETTER AGREEMENT BUT EURO REMAINS SLOWER
IN MOVING THE SYSTEM ACROSS THE AREA. FORECAST SOUNDINGS FOR
WEDNESDAY NIGHT SUGGEST TEMPERATURES SHOULD BE WARM ENOUGH ACROSS
THE SOUTH HALF OF THE AREA FOR PRECIP TO BE ALL LIQUID WITH
TEMPERATURES REMAINING ABOVE FREEZING ON THURSDAY ACROSS ALL THE
AREA AS RAIN CONTINUES.
.LONG TERM...THURSDAY NIGHT THROUGH MONDAY.
THE GFS AND ECM ARE IN RELATIVELY GOOD AGREEMENT WITH REGARDS TO
LARGE SCALE IN THE EXTENDED PD. BOTH ALSO SUGGESTING LITTLE CHANGE
NEEDED TO GOING FCST.
HEADING INTO NEXT WEEKEND...MODELS ADVERTISE SHORTWAVE ENERGY OVER
IA QUICKLY LIFTING TO THE GREAT LAKES REGION LATE THURSDAY NIGHT.
MEANWHILE UPSTREAM...A DEEP LONGWAVE TROF IS PROGGED TO EXTEND FROM
CNTRL CANADA ALL THE WAY TO THE SWRN CONUS. ON FRIDAY AS THE WRN
TROF GRADUALLY MIGRATES EAST...INTENSE BAROCLINIC ZONE BEGINS
SWEEPING ACROSS THE NRN/CNTRL PLAINS WITH THE LEADING EDGE OF THE
BOUNDARY REACHING THE CWA BY EARLY AFTN. COMBINATION OF INCREASING
MOISTURE AND STOUT AGEOSTROPHIC LIFT ALONG DEEP FRONTOGENETIC LYR
SHOULD BE ENOUGH TO INDUCE LIGHT SNOW ACTIVITY DURING THE FROPA
FRIDAY NIGHT.
ON SATURDAY...APPEARS TO BE A SMALL CHANCE FOR LIGHT POST-FRONTAL
SNOW ACTIVITY PER THE ECM. 300-500MB QVEC CONVERGENCE IMPLYING LIFT
VIA DPVA WHEN POTENT OR MAX ROUNDS THE BASE OF THE WRN TROF AND
LIFTS ACROSS THE CNTRL PLAINS. ON THE OTHER HAND...GFS AND CMC BOTH
SUGGESTING THE DEEP CAA WILL BE ADEQUATE TO SUPPRESS ANY LIFT VIA
DPVA. WILL OPTED FOR TOKEN 20S JUST IN CASE ECM SOLUTION WOULD
VERIFY.
OTHERWISE...TEMPS WILL PLUMMETS OVER THE PLAINS NEXT WEEKEND INTO
EARLY NEXT WEEK. EXPECT HIGHS SAT-MON WILL STRUGGLE TO REACH THE
LOW/MID 20S.
&&
.AVIATION...
18Z TAFS FOR KOFK...KOMA AND KLNK.
VFR CONDITIONS WERE FORECAST AT TAF SITES AS A WIND SHIFT BRINGS
A WEAKENING SURFACE GRADIENT. HOWEVER...IF HIGH CLOUDS CLEAR
MARKEDLY TONIGHT AND DEW POINT TEMPERATURES INCREASE A BIT MORE
THAN EXPECTED...FOG AND STRATUS COULD POSSIBLY DEVELOP OVER SNOW
AREA WHICH COULD IMPACT LNK/OMA TAF SITES TUESDAY MORNING. THIS
THREAT WILL BE ASSESSED IN FUTURE FORECASTS.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
FOBERT/DEE/CHERMOK
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
340 PM CST MON JAN 7 2013
.DISCUSSION.../ISSUED AT 340 PM/
MULTIPLE PLAYERS IN TODAY/S FORECAST FOR TONIGHT INTO TOMORROW.
CURRENTLY...MOSTLY CLEAR SKIES ACROSS THE AREA WITH A FEW HIGH
CLOUDS ACROSS CENTRAL SOUTH DAKOTA. THE SUNSHINE HAS PROMOTED SNOW
MELT...BUT WITH WEAK WINDS AND STRONG INVERSION...MOISTURE REMAINS
IN THE NEAR SURFACE LAYER. COULD SEE FOG DEVELOP OVERNIGHT
TONIGHT...BUT TRICKY TO PIN POINT WHERE EXACTLY. HRRR CONTINUES TO
SUGGEST THAT PATCHY FOG WILL BE POSSIBLY ACROSS THE NORTH...WHILE
NAM FOCUSES ON THE SOUTH AND EAST. HAVE SIDED CLOSER TO NAM...BUT
WITH WEAK WINDS...COULD GET RADIATIONAL FOG NEARLY ANYWHERE CLEAR
SKIES REMAIN FOR A FEW HOURS. AS MENTIONED IN THE MORNING
DISCUSSION...AMPLIFYING WAVE MOVING ACROSS THE AREA LATE TONIGHT
WITH UPPER LEVEL DIV Q INCREASING AFTER 06Z MAINLY ACROSS THE
NORTHERN HALF OF THE FORECAST AREA. WITH FAIRLY DRY AIR THROUGH THE
MID LEVELS OF THE ATMOSPHERE...AM NOT EXPECTING ANY PRECIPITATION
AND DROPPED MENTION OF SPRINKLES/FLURRIES FROM THE FORECAST. IF FOG
DEVELOPS IN THE SOUTHEAST...WILL NEED TO KEEP AN EYE ON DRIZZLE
POTENTIAL WITH WEAK LIFT IN THE LOW LEVELS OF THE ATMOSPHERE.
COLD FRONT IS POISED TO MOVE THROUGH THE AREA ON TUESDAY. SOUTHERLY
WINDS WILL BECOME WEST AND SOMEWHAT GUSTY BEHIND THE FRONT WITH
20-30 KNOTS OF FLOW AT 925 HPA. NOT MUCH IN THE WAY OF COLD AIR
ADVECTION BEHIND THE FRONT...AND WITH ONLY MEAGER PRESSURE RISES AND
STRONG INVERSION REMAINING ALOFT...WILL STRUGGLE TO GET A LOT OF THE
MOMENTUM DOWN THE SURFACE. STRONGEST WINDS WILL LIKELY BE ACROSS
THE NORTHERN EDGE OF THE FORECAST AREA WITH STRONGEST GRADIENT WINDS
THERE...BUT STILL LOOK TO REMAIN BELOW ADVISORY CRITERIA.
UPPER LEVEL TROUGH IS EXPECTED TO DIG ACROSS THE DESERT SOUTHWEST
MID WEEK...WHICH PUSHES THE RIDGE AXIS OVER THE FORECAST AREA ON
WEDNESDAY. EXPECT ANOTHER RELATIVELY MILD DAY WITH MOSTLY SUNNY
SKIES AND ABOVE NORMAL TEMPERATURES. EXPECT HIGHS TO REACH JUST
ABOVE FREEZING IN SOUTHWEST MINNESOTA AND ADJACENT AREAS...NUDGING
INTO THE UPPER 30S IN NORTHWEST IOWA. THE WARMEST READINGS WILL BE
FOUND IN SOUTH CENTRAL SOUTH DAKOTA WITH THE MID OR UPPER 40S IN
AREAS WHERE MUCH OF THE SNOWPACK HAS MELTED.
FOR THURSDAY...A CUT OFF LOW IS EXPECTED TO FORM IN THE SOUTHWEST
PLAINS AND TRACK NORTHEAST INTO THE NORTHERN GREAT LAKES EARLY
SATURDAY. SOME MODEL DIFFERENCES STILL EXIST...WITH THE ECMWF AND
GEM STILL FOLLOWING A SLOWER AND SLIGHTLY MORE SOUTHERLY TRACK. ALL
MODELS DO CLIP OUR SOUTHEASTERN COUNTIES AS THE SURFACE LOW TRACKS
INTO IOWA THURSDAY EVENING. TEMPERATURES WILL BE PARTICULARLY TRICKY
WITH READINGS EXPECTED TO RISE UP ABOVE FREEZING BY THE AFTERNOON.
WITH VERY WARM LOW LEVELS...EXPECT PRECIPITATION TO BE ENTIRELY
LIQUID FOR THIS SYSTEM...BUT WITH SURFACE READINGS POTENTIALLY BELOW
FREEZING IN THE MORNING AND AGAIN THURSDAY NIGHT...FREEZING RAIN
WILL ALSO BE POSSIBLE. BUT GIVEN THAT THESE TEMPERATURES WILL ONLY
BE A DEGREE OR TWO BELOW FREEZING...ICE ACCUMULATION DOES NOT LOOK
TO BE SIGNIFICANT. BUT WILL STILL CONTINUE TO MONITOR FOR ANY
CHANGES IN THIS OUTLOOK.
TEMPERATURES ON FRIDAY WILL LIKELY BE SOMEWHAT STEADY OR BEGIN TO
FALL IN THE AFTERNOON AS COOLER TEMPERATURES BEGIN TO FILTER INTO
THE AREA BEHIND THIS SYSTEM. THE BROAD POSITIVELY TILTED TROUGH
DIGGING ACROSS THE SOUTHWEST PUSHES INTO THE WESTERN PLAINS FRIDAY
EVENING...BRINGING THE NEXT POTENTIAL FOR WET WEATHER TO REGION
FRIDAY NIGHT AND SATURDAY. AGAIN...THE ECMWF IS A BIT SLOWER AND
SHOWS MORE OF A CLOSED UPPER LEVEL FEATURE. A SLIGHT CHANCE FOR SOME
LIGHT SNOW OR FLURRIES WILL BE POSSIBLE AHEAD OF THE MAIN WAVE ON
FRIDAY. THE DETAILS ARE STILL QUITE UNCERTAIN AT THIS POINT...BUT
THE GFS APPEARS TO TAKE THE BEST DYNAMICS WEST AND NORTH OF THE
FORECAST AREA...WHILE THE ECMWF HAS A BIT MORE ORGANIZATION WITH A
DECENT BAND OF MID LEVEL FRONTOGENESIS MOVING THROUGH THE FORECAST
AREA. WILL KEEP MENTION OF POPS AS A HIGH CHANCE FOR SOME LIGHT
SNOWFALL FRIDAY NIGHT AND SATURDAY. PRELIMINARY AMOUNTS LOOK LIKE A
FEW INCHES WOULD BE POSSIBLE ACROSS THE CWA.
THE LOW EXITS THE AREA SATURDAY NIGHT WITH A STRONGER SHOT OF COLD
AIR ADVECTION ARRIVING IN ITS WAKE. TEMPERATURES WILL BE MUCH COOLER
FOR THE START OF NEXT WEEK WITH HIGHS MAINLY IN THE TEENS AND LOWS
AROUND ZERO.
&&
.AVIATION.../FOR THE 18Z TAF ISSUANCE/
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. WEST TO SOUTHWEST
FLOW WILL REMAIN LIGHT THROUGHOUT THE DAY TODAY...AND GRADUALLY
TRANSITION TO SOUTHERLY ON TUESDAY. THERE IS THE POTENTIAL FOR SOME
FOG TO DEVELOP THROUGH THE OVERNIGHT HOURS TONIGHT...AND HAVE ADDED
MENTION TO TAFS EAST OF JAMES RIVER INCLUDING KFSD AND KSUX
TERMINALS. FOG COULD BE LOCALLY DENSE WITH WEAK WINDS.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$