Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 01/01/15
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
1057 PM PST MON DEC 29 2014
...WINDY AND COLDER WEATHER ON THE WAY FOR THE END OF 2014...
.SYNOPSIS...A FAST MOVING STORM SYSTEM WILL MOVE SOUTHEAST ACROSS
NEVADA TONIGHT BRINGING A SLIGHT CHANCE OF SHOWERS MAINLY IN THE HILLS.
COLDER AND WINDIER CONDITIONS WILL SETTLE OVER THE AREA TUESDAY AND
WEDNESDAY BEHIND THIS SYSTEM. A WARMING TREND WILL RETURN BY LATE
THIS WEEK.
&&
.DISCUSSION...AS OF 9:00 PM PST MONDAY...A COLD UPPER LEVEL LOW
OVER SOUTHEAST OREGON WILL DRIVE SOUTHEAST DURING THE NIGHT WITH THE
TROUGH AXIS MOVING THROUGH THE AREA LATE TONIGHT. THE SYSTEM HAS
VERY LITTLE MOISTURE BUT RECENT HRRR MODEL RUNS HAVE SHOWN
ISOLATED CONTOURS OF ONE TO TWO-HUNDREDTHS OF PRECIP IN THE HILLS.
A SLIGHT CHANCE OF SHOWERS IS IN THE FORECAST FOR TONIGHT BUT MOST
LIKELY ANY PRECIP WILL FALL OVER THE HILLS.
WINDS WILL INCREASE AS THIS TROUGH AXIS MOVES THROUGH WITH MODELS
SHOWING 925 MB WINDS INCREASING TO 35-45 KT RANGE TUESDAY MORNING.
MODELS ALSO SHOW DECENT OMEGA VALUES AFTER THE TROUGH PASSES
INDICATING THAT WINDS ALOFT COULD MIX DOWN TO THE SURFACE.
THEREFORE A WIND ADVISORY IS IN EFFECT BEGINNING TUESDAY MORNING
IN THE NORTH AND EAST BAY HILLS AND SANTA CRUZ MOUNTAINS FOR GUSTS
UP TO 55-60 MPH...AND MIDDAY TUESDAY FOR THE REST OF THE SFO BAY
AREA WITH GUSTS TO 40-45 MPH. STRONG WINDS WILL CONTINUE THROUGH
TUESDAY NIGHT AND MAY EVEN BE SLIGHTLY STRONGER THAN TUESDAY
MORNING. THESE STRONG WINDS WILL BRING DOWN SOME TREES AND CAUSE
POWER OUTAGES AS THE SOIL REMAINS FAIRLY WET FROM RAINS EARLIER
THIS MONTH.
WINDS WILL DECREASE BY MIDDAY WEDNESDAY AS THE LOW MOVES FURTHER
EAST AND AN UPPER LEVEL RIDGE BUILDS IN FROM THE WEST. COLD
NORTHERLY FLOW WILL CONTINUE OVER THE AREA THROUGH WEDNESDAY AND
WITH THE WINDS DIMINISHING IT WILL SET UP A COLD NIGHT FOR NEW
YEARS EVE. TEMPERATURES WILL DROP INTO THE 20S IN MANY OF THE
INLAND VALLEYS WITH LOWER TO MID 30S IN THE URBAN AREAS AROUND
OAKLAND-SAN JOSE. A FROST ADVISORY MAY BE NEEDED FOR MOST OF THE
SFO BAY AREA WEDNESDAY NIGHT.
TEMPERATURES WILL SLOWLY WARM UP THURSDAY THROUGH SUNDAY AS THE
UPPER LEVEL RIDGE MOVES OVER THE WEST COAST. IN THE LONG
RANGE...MODELS CONTINUE TO STRUGGLE WITH WHETHER THERE WILL BE
RAIN IN OUR CWA AROUND THE MIDDLE OF NEXT WEEK. LATEST GFS AND
ECMWF INDICATE A CHANCE FOR RAIN FOR AT LEAST THE NORTHERN PART OF
THE DISTRICT.
&&
.AVIATION...AS OF 10:45 PM PST MONDAY...THE LIMITED BAND OF LOW
AND MID LEVEL CLOUDINESS ASSOCIATED WITH THE MOSTLY DRY COLD
FRONT SWEEPING SOUTHWARD THROUGH CENTRAL CALIFORNIA IS NOW PASSING
THROUGH THE MONTEREY BAY REGION. BEHIND IT SKIES ARE EXPECTED TO
REMAIN MOSTLY CLEAR THROUGH THE NIGHT...AS THE BOUNDARY LAYER AIR
MASS LOOKS TO REMAIN SUFFICIENTLY DRY AND WELL MIXED AS TO
PRECLUDE ANY DEVELOPMENT OF FOG OR LOW CLOUDS.
ON TUESDAY HOWEVER...COUPLING OF A RAPIDLY INCREASING NORTH TO
SOUTH PRESSURE GRADIENT WITH STRONG NORTH-TO-NORTHEAST FLOW ALOFT WILL
RESULT IN INCREASINGLY STRONG WINDS OVER THE DISTRICT. KEY QUESTIONS ARE
WHEN...WHERE...AND TO WHAT DEGREE THESE WILL MIX DOWN TO THE
SURFACE AT LOW ELEVATIONS. HIGH RESOLUTION LOCAL MODEL OUTPUT
INDICATES THIS WILL IN FACT PROGRESSIVELY OCCUR AT SFO BAY AREA
TAF SITES DURING THE DAY ON TUESDAY...WITH WINDS LIKELY BECOMING
LOCALLY STRONG AND GUSTY BY AFTERNOON.
VICINITY OF KSFO...MOSTLY CLEAR SKIES THROUGH THE REMAINDER OF THE NIGHT
AND ALL DAY ON TUESDAY AS THE POST-FRONTAL AIR MASS REMAINS DRY
AND WELL MIXED. WINDS VEER NORTH-NORTHEASTERLY TOMORROW AND ARE
LIKELY TO BECOME STRONG AND GUSTY BY AFTERNOON. MEDIUM-TO-HIGH CONFIDENCE.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...VFR CONDITIONS WITH GENERALLY LIGHT
WINDS THROUGH THE PERIOD. MEDIUM CONFIDENCE.
&&
.MARINE...AS OF 01:38 PM PST MONDAY...STRONG HIGH PRESSURE WILL
BUILD OVER THE GREAT BASIN INCREASING NORTHERLY WINDS THROUGH
WEDNESDAY. WINDS DECREASE WEDNESDAY NIGHT AND THURSDAY AS THE HIGH
WEAKENS.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...SCA...PIGEON PT TO PT PINOS 0-10 NM
SCA...PIGEON PT TO PT PINOS 10-60 NM
SCA...PT PINOS TO PT PIEDRAS BLANCAS 10-60 NM
SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM UNTIL 3 AM
SCA...PT ARENA TO PT REYES 0-10 NM
SCA...PT ARENA TO PT REYES 10-60 NM
SCA...PT REYES TO PIGEON PT 0-10 NM
SCA...PT REYES TO PIGEON PT 10-60 NM
&&
$$
PUBLIC FORECAST: W PI
AVIATION/MARINE: BLIER
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AREA FORECAST DISCUSSION
NWS RENO NV
936 PM PST MON DEC 29 2014
.UPDATE...
JUST A FEW MINOR FORECAST TWEAKS THIS EVENING. WE ARE STILL ON
TRACK FOR A LIGHT SNOWFALL LATER TONIGHT. HOWEVER, THE INITIAL
BAND ASSOCIATED WITH SHALLOWER LIFT/MOISTURE HAS MOVED TO BETWEEN
RENO AND CARSON CITY AND IS NOT THE MAIN BAND OF SNOW FOR THE
AREA.
THE MAIN EVENT FOR THE RENO-SPARKS AND CARSON CITY-MINDEN AREAS
LOOKS TO BE LATER TONIGHT AS THE MAIN UPPER COLD POOL/TROUGH AXIS
APPROACHES. THIS IS EVIDENCED BY INCREASING RADAR RETURNS UP AROUND
PYRAMID LAKE AND COLDER CLOUD TOPS IN THE INFRARED SATELLITE NORTH
OF RENO. ALONG WITH A LIGHT SNOWFALL FOR MOST OF WESTERN NEVADA,
THE INSTABILITY AND DEEPER MOISTURE WITH THE COLD POOL SHOULD
COMBINE WITH UPSLOPE FLOW AGAINST THE CARSON RANGE TO PRODUCE
LOCALLY HIGHER SNOWFALL TOTALS IN THE FOOTHILLS SOUTH AND WEST OF
RENO. SNYDER
&&
.SYNOPSIS...
A STRONG COLD FRONT WILL PUSH THROUGH THE AREA TONIGHT. SNOWFALL IS
POSSIBLE WITH POTENTIAL TRAVEL IMPACTS FOR THE TUESDAY MORNING
COMMUTE ALONG THE HIGHWAY 395 CORRIDOR. STRONG WINDS ARE EXPECTED TO
PRODUCE ROUGH CONDITIONS ON AREA LAKES ALONG WITH POSSIBLE AREAS OF
BLOWING SNOW. TEMPERATURES WILL BE BITTER COLD WITH WIND CHILLS IN
THE SINGLE DIGITS AND NEGATIVE VALUES HEADING INTO THE NEW YEAR. A
MILDER PATTERN WILL RETURN FOR THE WEEKEND.
&&
.PREVIOUS DISCUSSION... /ISSUED 242 PM PST MON DEC 29 2014/
SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT
VISIBLE SATELLITE IMAGERY SHOWING A COLD UPPER LOW ACROSS THE
PACIFIC NORTHWEST WITH COOLING IR COLD TOPS ALONG A STRONG COLD
FRONT OVER SOUTHERN OREGON. THIS FRONT WILL QUICKLY DRIVE SOUTH
THROUGH NORTHERN NEVADA TONIGHT INTO TUESDAY MORNING PROVIDING THE
POTENTIAL FOR A FEW INCHES OF SNOWFALL AND BITTER COLD HEADING INTO
THE NEW YEAR.
HI-RES MESOSCALE AND GLOBAL MODELS ARE BEGINNING TO CLUE INTO THE
FORMATION OF BANDED SNOWFALL CREATED BY STRONG LOW LEVEL
FRONTOGENESIS AND MOISTURE IN A REGION OF FAVORABLE MICROPHYSICS FOR
ICE CRYSTAL GROWTH. THESE COLD TEMPERATURES WILL MAKE FOR LIGHT
AND FLUFFY SNOW. SOME DISAGREEMENT ON TIMING BUT LARGELY LOOKING
FOR SNOWFALL IN THE RENO/CARSON CITY REGION AS EARLY 8PM BUT THE
MOST FAVORABLE WINDOW LOOKS TO BE BETWEEN 10PM-4AM. A WINTER
WEATHER ADVISORY HAS BEEN POSTED FOR THE SIERRA FRONT WHICH
INCLUDES THE HWY 395 CORRIDOR SOUTH THROUGH MINDEN AND
GARDNERVILLE. THE ADVISORY ALSO COVERS PORTIONS OF WESTERN MINERAL
AND SOUTHERN LYON COUNTY. GENERALLY LOOKING FOR SNOWFALL IN THE
1-2" RANGE FROM RENO TO CARSON CITY WITH HIGHER AMOUNTS SOUTH
WHERE UPSLOPE FORCING WILL ADD ADDITIONAL LIFT. LOCATIONS ALONG
THE EASTERN SLOPES OF THE CARSON RANGE, EASTERN ALPINE CO,
NORTHERN MONO COUNTY COULD SEE MORE IN THE 2-4" RANGE. SLIDERS ARE
NOTORIOUSLY DIFFICULT SYSTEMS TO FORECAST SO WILL PUT FORECAST
CONFIDENCE IN SNOW AMOUNTS IN THE MEDIUM CATEGORY.
THE OTHER IMPACTS WITH THIS SYSTEM WILL BE SOME GUSTY CONDITIONS
BEHIND THE FRONT AS A STRONG PRESSURE GRADIENT DEVELOPS ACROSS
WESTERN NEVADA AND THE SIERRA. EXPECTING TO SEE SUSTAINED WINDS IN
THE 15-25 MPH RANGE WITH GUSTS UP TO 40-45 MPH OUT OF THE EAST WHICH
PUTS THIS JUST BELOW ADVISORY CRITERIA ACROSS WESTERN NEVADA. HAVE
HOWEVER POSTED A LAKE WIND ADVISORY FOR PYRAMID LAKE AND A WIND
ADVISORY ACROSS THE TAHOE BASIN. EXPECTING HAZARDOUS BOATING
CONDITIONS ON AREA LAKES WITH GUSTS NEAR 45 MPH EXPECTED IN THE
TAHOE BASIN WITH HIGHEST WAVES ALONG THE ATYPICAL WESTERN SHORES.
WINDS WILL SHARPLY INCREASE IN ELEVATION WITH VERY STRONG WINDS
EXPECTED MAINLY ABOVE 8,500 FEET WHERE GUSTS BETWEEN 80-100+ MPH ARE
POSSIBLE. THIS MAY ALSO POSE THE RISK FOR TREE FALLS ACROSS THE
TAHOE BASIN PARTICULARLY FOR TREES WEAKENED FROM THE PAST WIND
EVENT. THE SAME STRONG WINDS HOLD TRUE ACROSS HIGH TERRAIN THROUGH
MONO COUNTY BUT THE STRONGEST WINDS WILL REMAIN OVER THE CREST AND
ALONG THE WESTERN SLOPES OF THE SIERRA WHERE VERY STRONG DOWNSLOPE
WINDS LOOK FAVORABLE.
OTHERWISE, LOOKING FOR SNOW SHOWERS TO LINGER THROUGH TUESDAY
AFTERNOON ESPECIALLY ACROSS ALPINE AND MONO COUNTY WHERE UPSLOPE
FORCING SETS UP. AN INCH OR TWO IS POSSIBLE ACROSS THE TAHOE BASIN
AND MONO COUNTY OUTSIDE OF AREAS OF LAKE ENHANCED SNOWFALL. STRONG
WINDS MAY ALSO PRODUCE AREAS OF BLOWING SNOW AND REDUCED VISIBILITY.
FUENTES
(WEDNESDAY AND THURSDAY)..
MAIN CHANGE TO THE WEDNESDAY-THURSDAY TIME FRAME WAS LOWERING MAX
AND MIN TEMPS BY A FEW DEGREES EACH, WITH THE INCREASED
EXPECTATION OF ACCUMULATING SNOW WITH THE UPPER LOW PASSING
THROUGH TONIGHT AND TUESDAY. THE PRESENCE OF SNOW COVER WILL
STRENGTHEN THE VALLEY INVERSION FURTHER AND KEEP HIGHS ONLY IN THE
LOWER-MID 20S WEDNESDAY. STRONG NE-E WINDS WILL CONTINUE OVER THE
SIERRA RIDGES WITH GUSTS 75-85 MPH, WHILE SURFACE WIND GUSTS WILL
GENERALLY RANGE FROM 25-35 MPH EXCEPT NEAR 40 MPH AROUND TAHOE
WEDNESDAY MORNING. THESE WINDS WILL DECREASE LATER IN THE DAY AS
THE UPPER LOW MOVES FROM SOUTHEAST CA TO ARIZONA.
NEW YEARS EVE WILL BE QUITE COLD WITH TEMPERATURES BY MIDNIGHT
DROPPING TO THE LOWER TEENS FOR RENO-CARSON CITY AND SINGLE DIGITS
AROUND TAHOE. ALTHOUGH WINDS WILL BE DECREASING, WIND CHILLS COULD
STILL BE NEAR ZERO FOR WESTERN NV AND -10 DEGREES IN THE TAHOE BASIN
FOR THE FIRST COUPLE HOURS OF 2015. THE EARLY MORNING LOWS FOR NEW
YEARS DAY ARE LIKELY TO BE AROUND 5 DEGREES FOR URBAN AREAS OF
WESTERN NV, AND BELOW ZERO AWAY FROM THE MAIN CITIES AND IN THE
SIERRA VALLEYS.
ON THURSDAY, THE CORE OF THE COLD AIR MASS WILL MOVE AWAY FROM
WESTERN NV BUT WITH INVERSION STILL IN PLACE, HIGHS ARE LIKELY TO
REMAIN BELOW FREEZING. LIGHTER WINDS ARE EXPECTED WITH DRY
CONDITIONS PREVAILING THROUGH THE FIRST DAY OF 2015. MJD
LONG TERM (FRIDAY-MONDAY)...
THE MOTTO FOR THE LONG TERM WILL BE "WELCOME TO INVERSION CITY".
GUIDANCE CONSENSUS SHOWS RIDGING JUST OFF THE WEST COAST THROUGH THE
WEEKEND WHICH YIELDS WARMING TEMPERATURES AT 700MB. COUPLED WITH A
SURFACE HIGH OVER THE INTERMOUNTAIN WEST THIS RESULTS IN AN
INVERSION PATTERN FOR THE VALLEYS OF WESTERN NV AND NORTHEAST CA,
WITH LIGHT WINDS, LIMITED MIXING, AND POTENTIAL AIR POLLUTION
BUILDUPS. TEMPERATURES IN VALLEYS WILL WARM EACH DAY BUT AT A MUCH
SLOWER RATE COMPARED TO THE MOUNTAINS. IF WE GET SUFFICIENT SNOWFALL
TONIGHT THEN THOSE INVERSIONS COULD BE STRONGER WITH POTENTIAL FOR
SPOTS OF FREEZING FOG IN NORMALLY PRONE AREAS.
UNFORTUNATELY I`M REALLY NOT SEEING MEANINGFUL STORM POTENTIAL
THROUGH AT LEAST MONDAY AS THE RIDGE BLOCKS PACIFIC STORMS FROM
IMPACTING CA/NV. THERE ARE SOME SIGNS OF THE RIDGE BREAKING DOWN OR
BEING UNDERCUT MID/LATE NEXT WEEK ALLOWING AN INCREASED CHANCE OF
ATMOSPHERIC RIVERS LANDFALLING ON THE WEST COAST. BUT OF COURSE
PREDICTABILITY OF THESE PATTERN CHANGES 7-10 DAYS OUT IS QUITE
LIMITED. CS
AVIATION...
FORECAST CONFIDENCE IN TODAY`S TAFS IS MEDIUM, WITH UNCERTAINTIES IN
TIMING AND INTENSITY OF TONIGHT`S BAND OF SNOW. THESE KIND OF SLIDER
STORMS ARE A CHALLENGE TO PREDICT SO SNOWFALL POTENTIAL REMAINS ONLY
MEDIUM CONFIDENCE AS WELL. HIGH RESOLUTION SIMULATIONS (HRRR) ARE
SHOWING A FAST MOVING BAND OF -SN DEVELOPING FROM AAT-LOL AROUND
SUNDOWN AND THEN DROPPING SOUTHWARD INTO RNO/CXP 4-10Z, TRK/TVL/MEV
AROUND 6-12Z, AND AFTER 12Z AT MMH. IN SUCH A STRONGLY FORCED
SITUATION THE HRRR USUALLY DOES REASONABLY WELL SO WE`LL FOLLOW FOR
THE TAFS.
PERIODS OF MVFR/IFR -SN LIKELY AT RNO/CXP/TRK/TVL/MEV TONIGHT
YIELDING UP TO 2 INCHES OF FLUFFY SNOW. THERE`S ABOUT A 20% CHANCE
WE COULD SEE BRIEF PERIODS OF HEAVIER SNOW, 1/2SM VISIBILITY TYPE
STUFF, BUT PREDICTING TIMING ON THAT IS TRICKY. GUSTY N/NE WINDS
WILL RESULTING IN BLOWING SNOW AS WELL. CLOUDS WILL RESULT IN
TERRAIN OBSCURATION TONIGHT THROUGH TOMORROW.
THE POST-FRONTAL NORTHEAST WINDS TUESDAY WILL BE PRONOUNCED AND
GUSTY, WITH A FRESH SUSTAINED 15-25 KTS EAST/NORTHEAST WIND WITH
GUSTS 25-30 KTS. CXP WHICH IS PRONE TO NE FLOW EVENTS, WILL LIKELY
SEE PERIODS OF STRONGER SUSTAINED WINDS. RIDGE LEVEL GUSTS OF 60-70
KTS FORECAST TOMORROW, INCREASING TUESDAY NIGHT INTO WEDNESDAY. DUE
TO THE UNUSUAL NE WIND DIRECTION, THAT WILL LEAD TO TURBULENCE
ESPECIALLY WEST OF ANY MOUNTAINS DUE TO MOUNTAIN WAVE ACTIVITY. CS
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...LAKE WIND ADVISORY FROM 7 AM TO 7 PM PST TUESDAY FOR PYRAMID
LAKE IN NVZ004.
WIND ADVISORY FROM 7 AM TUESDAY TO 4 AM PST WEDNESDAY NVZ002.
WINTER WEATHER ADVISORY UNTIL 4 PM PST TUESDAY NVZ001.
WINTER WEATHER ADVISORY UNTIL 10 AM PST TUESDAY NVZ003.
CA...WIND ADVISORY FROM 7 AM TUESDAY TO 4 AM PST WEDNESDAY CAZ072.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
919 PM PST MON DEC 29 2014
...WINDY AND COLDER WEATHER ON THE WAY FOR THE END OF 2014...
.SYNOPSIS...A FAST MOVING STORM SYSTEM WILL MOVE SOUTHEAST ACROSS
NEVADA TONIGHT BRINGING A SLIGHT CHANCE OF SHOWERS MAINLY IN THE HILLS.
COLDER AND WINDIER CONDITIONS WILL SETTLE OVER THE AREA TUESDAY AND
WEDNESDAY BEHIND THIS SYSTEM. A WARMING TREND WILL RETURN BY LATE
THIS WEEK.
&&
.DISCUSSION...AS OF 9:00 PM PST MONDAY...A COLD UPPER LEVEL LOW
OVER SOUTHEAST OREGON WILL DRIVE SOUTHEAST DURING THE NIGHT WITH THE
TROUGH AXIS MOVING THROUGH THE AREA LATE TONIGHT. THE SYSTEM HAS
VERY LITTLE MOISTURE BUT RECENT HRRR MODEL RUNS HAVE SHOWN
ISOLATED CONTOURS OF ONE TO TWO-HUNDREDTHS OF PRECIP IN THE HILLS.
A SLIGHT CHANCE OF SHOWERS IS IN THE FORECAST FOR TONIGHT BUT MOST
LIKELY ANY PRECIP WILL FALL OVER THE HILLS.
WINDS WILL INCREASE AS THIS TROUGH AXIS MOVES THROUGH WITH MODELS
SHOWING 925 MB WINDS INCREASING TO 35-45 KT RANGE TUESDAY MORNING.
MODELS ALSO SHOW DECENT OMEGA VALUES AFTER THE TROUGH PASSES
INDICATING THAT WINDS ALOFT COULD MIX DOWN TO THE SURFACE.
THEREFORE A WIND ADVISORY IS IN EFFECT BEGINNING TUESDAY MORNING
IN THE NORTH AND EAST BAY HILLS AND SANTA CRUZ MOUNTAINS FOR GUSTS
UP TO 55-60 MPH...AND MIDDAY TUESDAY FOR THE REST OF THE SFO BAY
AREA WITH GUSTS TO 40-45 MPH. STRONG WINDS WILL CONTINUE THROUGH
TUESDAY NIGHT AND MAY EVEN BE SLIGHTLY STRONGER THAN TUESDAY
MORNING. THESE STRONG WINDS WILL BRING DOWN SOME TREES AND CAUSE
POWER OUTAGES AS THE SOIL REMAINS FAIRLY WET FROM RAINS EARLIER
THIS MONTH.
WINDS WILL DECREASE BY MIDDAY WEDNESDAY AS THE LOW MOVES FURTHER
EAST AND AN UPPER LEVEL RIDGE BUILDS IN FROM THE WEST. COLD
NORTHERLY FLOW WILL CONTINUE OVER THE AREA THROUGH WEDNESDAY AND
WITH THE WINDS DIMINISHING IT WILL SET UP A COLD NIGHT FOR NEW
YEARS EVE. TEMPERATURES WILL DROP INTO THE 20S IN MANY OF THE
INLAND VALLEYS WITH LOWER TO MID 30S IN THE URBAN AREAS AROUND
OAKLAND-SAN JOSE. A FROST ADVISORY MAY BE NEEDED FOR MOST OF THE
SFO BAY AREA WEDNESDAY NIGHT.
TEMPERATURES WILL SLOWLY WARM UP THURSDAY THROUGH SUNDAY AS THE
UPPER LEVEL RIDGE MOVES OVER THE WEST COAST. IN THE LONG
RANGE...MODELS CONTINUE TO STRUGGLE WITH WHETHER THERE WILL BE
RAIN IN OUR CWA AROUND THE MIDDLE OF NEXT WEEK. LATEST GFS AND
ECMWF INDICATE A CHANCE FOR RAIN FOR AT LEAST THE NORTHERN PART OF
THE DISTRICT.
&&
.AVIATION...AS OF 4:45 PM PST MONDAY...PATCHES OF LOW AND MID
LEVEL CLOUDINESS REMAIN OVER PORTIONS OF THE DISTRICT BUT WITH ALL
TERMINALS NOW REPORTING VFR CONDITIONS. THESE SHOULD CONTINUE THROUGH
THE NIGHT AS THE BOUNDARY LAYER AIR MASS LOOKS TO REMAIN
SUFFICIENTLY DRY AND WELL MIXED AS TO PRECLUDE DEVELOPMENT OF EITHER
FOG OR CIGS.
THE PASSAGE OF A STRONG BUT DRY UPPER LEVEL DISTURBANCE FROM THE
NORTH TONIGHT...IN CONJUNCTION WITH DEVELOPMENT OF A STRONG NE TO SW
ORIENTED SEA LEVEL PRESSURE GRADIENT...WILL RESULT IN INCREASINGLY
STRONG NORTH TO NORTHEASTERLY FLOW ALOFT OVER THE AREA. KEY
QUESTIONS ARE WHEN...WHERE...AND TO WHAT DEGREE THESE WINDS MIX
DOWN TO THE SURFACE. HIGH RESOLUTION LOCAL MODEL OUTPUT INDICATES
THIS WILL PROGRESSIVELY OCCUR AT SFO BAY AREA TAF SITES DURING THE
DAY ON TUESDAY...WITH WINDS POTENTIALLY BECOMING LOCALLY STRONG
AND GUSTY BY AFTERNOON.
VICINITY OF KSFO...NO MORE THAN SCATTERED CLOUDINESS IS EXPECTED
OVERNIGHT AND TUESDAY MORNING AS THE AIR MASS REMAINS DRY AND
WELL MIXED. WINDS VEER NORTH-NORTHEASTERLY TOMORROW AND ARE
LIKELY TO BECOME STRONG AND GUSTY BY AFTERNOON. MEDIUM CONFIDENCE.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...VFR CONDITIONS WITH GENERALLY LIGHT
WINDS THROUGH THE PERIOD. MEDIUM CONFIDENCE.
&&
.MARINE...AS OF 01:38 PM PST MONDAY...STRONG HIGH PRESSURE WILL
BUILD OVER THE GREAT BASIN INCREASING NORTHERLY WINDS THROUGH
WEDNESDAY. WINDS DECREASE WEDNESDAY NIGHT AND THURSDAY AS THE HIGH
WEAKENS.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...SCA...PT PINOS TO PT PIEDRAS BLANCAS 10-60 NM
SCA...PT REYES TO PIGEON PT 0-10 NM
SCA...PT REYES TO PIGEON PT 10-60 NM
SCA...PT ARENA TO PT REYES 0-10 NM
SCA...PT ARENA TO PT REYES 10-60 NM
SCA...PIGEON PT TO PT PINOS 10-60 NM
SCA...PT REYES TO PIGEON PT 0-10 NM
SCA...PIGEON PT TO PT PINOS 0-10 NM
&&
$$
PUBLIC FORECAST: W PI
AVIATION: BLIER
MARINE: AC
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AREA FORECAST DISCUSSION
NWS MIAMI FL
430 PM EST TUE DEC 30 2014
...VERY WARM, HUMID PATTERN TO CONTINUE INTO THE NEW YEAR...
.UPDATE...SEA BREEZES HAVE DEVELOPED ALONG BOTH THE GULF AND
ATLANTIC COASTS THIS AFTERNOON...CLEARLY SEEN IN VISIBLE SATELLITE
IMAGERY. PRETTY RARE FOR WINTERTIME! ENOUGH LOW LEVEL MOISTURE IS
PRESENT TO HAVE CU FORMING ALONG THE SEA BREEZE FRONTS, BUT NOT
QUITE ENOUGH TO GET SHOWERS GOING. HRRR IS OVERDOING QPF AS RADAR
CONTINUES TO SHOW NO SHOWER ACTIVITY (ECHOES SOUTH OF LAKE
OKEECHOBEE ARE REFLECTIVE OF SUGARCANE BURNING). AS DAYTIME
HEATING IS LOSS, IT LOOKS LIKE CONDITIONS WILL REMAIN DRY THROUGH
TONIGHT...BUT AS THE WEAKENING COLD FRONT OVER CENTRAL FLORIDA
SAGS SOUTHWARD, SOME CONVERGENCE ALONG THE PALM BEACH COAST COULD
ALLOW FOR A FEW SHOWERS TO DEVELOP THERE LATER TONIGHT...SO KEPT
SHOWER MENTION IN THERE ONLY.
SOUTH FL CONTINUES WITH ABOVE NORMAL TEMPS ALONG WITH
HUMIDITY...AND THIS WILL CONTINUE INTO THE WEEKEND AND EARLY NEXT
WEEK! A RECORD HIGH OF 83F WAS TIED AT MIAMI TODAY. THE HOTTEST
READINGS WERE FROM OPA LOCKA (KOPF) TO PEMBROKE PINES (KHWO) TO
WEST PALM BEACH (KPBI) WHERE HIGHS OFFICIALLY REACHED 85F, THE
WARMEST IN THE COUNTRY (FOR MAJOR REPORTING STATIONS/SOME UPPER
80S WERE REGISTERED BY MESONETS OVER PORTIONS OF INTERIOR SOUTH FL
THIS AFTERNOON).
THE WARM PATTERN WILL CONTINUE WITH POSSIBLY BUILDING HEAT BY THIS
WEEKEND. ECMWF INDICATES MAX TEMPS INTO THE MID-UPPER 80S EAST
COAST METRO WITH DEWPOINTS INTO THE LOWER 70S EQUATING TO HEAT
INDICES INTO THE LOWER 90S! GFS AND MODEL BLENDS OFFER SLIGHTLY
COOLER READINGS...AND THAT`S WHAT OUR CURRENT FORECAST REFLECTS.
HOWEVER, WE VERY WELL MAY NEED TO INCREASE OUR HIGHS PROJECTED FOR
THIS UPCOMING WEEKEND. A POSSIBLE "MINI-HEAT WAVE" TO START 2015.
/GREGORIA
&&
.PREV DISCUSSION... /ISSUED 247 PM EST TUE DEC 30 2014/
SHORT TERM (TONIGHT-NEW YEARS` DAY)...
A MOSTLY ZONAL UPPER FLOW PATTERN WILL CONTINUE ACROSS SOUTH FLORIDA
THROUGH NEW YEARS` DAY AS A STRONG RIDGE REMAINS ACROSS CUBA AND THE
BAHAMA ISLANDS. A WEAK COLD FRONT CURRENTLY IN NORTH CENTRAL
FLORIDA WILL OOZE INTO SOUTH FLORIDA TONIGHT AND WEDNESDAY BEFORE
STALLING AND RAPIDLY BECOME DIFFUSE. THERE WILL BE SOME CLOUDS
WITH THE FRONTAL BOUNDARY BUT VERY LITTLE IN THE WAY OF RAINFALL
AS DEEP LAYER MOISTURE WILL BE LACKING. THERE IS SOME POTENTIAL
FOR FOG AGAIN OVER THE INTERIOR AHEAD OF THE FRONT. HOWEVER,
EXTENSIVE CLOUD COVER WILL LIKELY HAMPER FOG DEVELOPMENT AND WILL
LEAVE OUT OF FORECAST AT THIS TIME WITH THE SREF ONLY SHOWING A
30-40% CHANCE OF VISIBILITY LOWERING LESS THAN THREE MILES. DUE TO
THE LACK OF PUSH WITH THIS FRONT, THE STRONG SUBSIDENCE CAP
CURRENTLY OVER SOUTH FLORIDA WILL BE SLOW TO ERODE WITH FORECAST
SOUNDINGS ONLY INDICATING SOME INSTABILITY BY LATE WEDNESDAY AND
EVEN THEN A PWAT OF ONLY AROUND 1.3".
LONG TERM (FRIDAY-TUESDAY)...
NOT MANY CHANGES SEEN TO THE UPPER FLOW PATTERN IN THE EXTENDED
PERIOD AS THE SUBTROPICAL RIDGE REMAINS FIRMLY ENTRENCHED IN ITS
POSITION ACROSS THE BAHAMA ISLAND CHAIN. AT THE SURFACE, WHAT IS
LEFT OF THE FRONTAL BOUNDARY WILL LIFT BACK TO THE NORTH WEDNESDAY
NIGHT OR THURSDAY. THIS IS IN RESPONSE TO A POWERFUL TROUGH
CURRENTLY DEEPENING INTO THE FOUR CORNERS AREA THAT WILL MOVE INTO
THE CENTRAL/SOUTHERN PLAINS ON FRIDAY NIGHT AND SATURDAY THEN INTO
THE GREAT LAKES AND NEW ENGLAND THIS WEEKEND. A COLD FRONT
ASSOCIATED WITH THIS SYSTEM WILL THEN MOVE INTO NORTH FLORIDA ON
SUNDAY WHERE IT WILL STALL INTO EARLY NEXT WEEK. SO THESE TWO
PARAGRAPHS SPELL OUT A WARM AND GENERALLY DRY PATTERN FOR SOUTH
FLORIDA TO END THIS YEAR AND THE BEGINNING OF THE NEW YEAR.
MARINE...
GOOD BOATING CONDITIONS WILL CONTINUE THROUGH THE FORECAST PERIOD
WITH A LIGHT WIND EXPECTED AND SEAS 4 FEET OR LESS. THE PRESSURE
GRADIENT WILL REMAIN WEAK AS THE COLD FRONT BECOMES DIFFUSE AND
THEN SLOWLY LIFTS TO THE NORTH TOWARDS THE END OF THE WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 69 79 68 78 / 20 40 20 20
FORT LAUDERDALE 70 80 69 79 / 10 30 20 20
MIAMI 70 81 69 80 / 10 20 10 20
NAPLES 66 79 65 79 / 10 20 10 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
300 PM EST TUE DEC 30 2014
.UPDATE (REST OF TODAY THROUGH WEDNESDAY)...
20Z WATER VAPOR AND H4 RAP ANALYSIS CONTINUE TO SHOW MUCH OF THE
NATION UNDER A BROAD LONGWAVE TROUGH. THE MOST ENERGETIC FEATURE
WITHIN THIS TROUGH IS A STRONG SHORTWAVE DROPPING SOUTH THROUGH THE
INTERMOUNTAIN WEST WHICH IS PROGGED BY ALL THE NUMERICAL GUIDANCE TO
BECOME A LARGE CUTOFF LOW OVER THE SOUTHWESTERN STATES BEFORE
EJECTING EASTWARD ACROSS THE SOUTHERN/CENTRAL PLAINS LATER IN THE
WEEK. OUR FORECAST AREA RESIDES WITHIN A ZONE OF DEEP LAYER
SOUTHWEST FLOW BETWEEN THE LONGWAVE TROUGH AND AND WEST-EAST
ORIENTED RIDGE ACROSS THE NORTHWEST CARIBBEAN. A PLUME OF SOUTHERN
STREAM MOISTURE IS STILL IN WV IMAGERY RIDGING THIS FLOW OVER THE
EASTERN GULF OF MEXICO AND FL PENINSULA.
AT THE SURFACE...A WEAK COLD FRONT IS NOW ALIGNED ACROSS THE CENTRAL
FLORIDA PENINSULA AND IS MAKING VERY SLOW PROGRESS SOUTHWARD.
REGIONAL RADARS SHOW A SWATH OF LIGHT SHOWERS AND AREAS OF DRIZZLE
ALONG AND NOW BEHIND THIS BOUNDARY. THIS TRANSITION FROM A KATAFRONT
TO AN ANAFRONT CONFIGURATION HAS HELPED KEEP THE RAIN ACROSS MANY OF
THE SAME PLACES SO FAR TODAY...EVEN THROUGH THE FRONT ITSELF HAS
MADE STEADY PROGRESS TO THE SOUTH SINCE EARLY THIS MORNING.
&&
.SHORT TERM (REST OF TODAY THROUGH WEDNESDAY)...
REST OF TODAY...THE FRONT STILL LOOKS TO SLOWLY SETTLE SOUTH TO NEAR
PUNTA GORDA AROUND SUNSET. THE ORGANIZATION AND COVERAGE OF SHOWERS
HAS DIMINISHED SOMEWHAT IN THE PAST COUPLE OF HOURS AS THE WEAK
SHORTWAVE TO OUR NORTH IS NOW PASSING BY. HOWEVER...THE LOW LEVEL
BOUNDARY FOCUS WILL STILL KEEP THE CHANCE FOR MORE SCT SHOWERS IN
THE FORECAST...GENERALLY SOUTH OF HERNANDO COUNTY AND TO THE NORTH
OF THE SARASOTA TO PUNTA GORDA REGION. ALSO WITH THE FLOW BECOMING
MORE AND MORE PARALLEL TO THE FRONT...THE ACTUALLY BOUNDARY PASSAGE
WILL NOT NECESSARILY END THE CHANCE FOR RAIN. MANY OF THE GUIDANCE
MEMBERS WERE INDICATING THE BOUNDARY TAKING ON AN INCREASINGLY
ANAFRONT CONFIGURATION WHERE BETTER CHANCES FOR THE CLOUDS AND
SHOWERS ARE ACTUALLY ALONG AND BEHIND THE BOUNDARY. THIS APPEARS TO
BE TAKING SHAPE THIS AFTERNOON AS THE FRONT IS NOW DOWN SOUTH OF THE
TAMPA BAY/POLK COUNTY REGION...AND YET MUCH OF THE LIGHT
SHOWERS/DRIZZLE ARE STILL REMAINS ALONG THE GENERAL I-4 CORRIDOR.
FOR OUR FAR NORTHERN ZONES...THE RAIN IS OVER AND DRIER AIR WILL
CONTINUE TO SETTLE BEHIND THE FRONT THROUGH EARLY THIS EVENING.
FOR OUR FAR SOUTHERN ZONES...WELL...THE WITH THE FRONT BECOMING MORE
ANAFRONT WITH TIME...THE SHOWERS SOUTHWARD MARCH AS SLOWED TO A
CRAWL. EVENTUALLY A FEW SHOWERS/PATCHES OF DRIZZLE SHOULD MAKE IT
DOWN TO SARASOTA/PUNTA GORDA AND FORT MYERS...BUT IS LOOKING MORE
LIKELY TO BE TONIGHT THAN DURING THE ACTUAL DAYLIGHT HOURS TODAY.
TONIGHT AND WEDNESDAY...THE FRONT STALLS AND BEGINS TO WASH OUT OVER
THE SOUTHERN PENINSULA. WILL KEEP LOW POPS FOR LIGHT SHOWERS/DRIZZLE
FOR THE FIRST HALF OF THE OVERNIGHT...MAINLY TO THE SOUTH OF THE
TAMPA BAY REGION AND THEN LOOKS AS THROUGH MOST OF THE ACTIVITY
SHOULD FADE. THERE IS GOING TO BE QUITE A BIT OF LOW LEVEL MOISTURE
STILL IN PLACE OVERNIGHT...AND THE SREF AND STATISTICAL GUIDANCE ARE
SHOWING A LOT OF LOWER CLOUDS DEVELOPING. SO EVEN PLACE THAT DO NOT
CLOUD OVER DURING THE DAY FROM THE FRONT ITSELF...SHOULD BEGIN TO
BECOME OVERCAST OVERNIGHT. THESE CLOUDS WILL LIKELY BE WITH US FOR A
GOOD PORTION OF THE DAY ON WEDNESDAY (ESPECIALLY THE FIRST
HALF)...AND HENCE WILL NOT HAVE ALL THAT MUCH SUN IN THE FORECAST
FOR WEDNESDAY. THE GUIDANCE MEMBERS ARE INDICATING THE DEVELOPMENT
OF AN INVERTED TROUGH OVER THE GULF STREAM OFF THE FL EAST COAST
DURING LATER TONIGHT AND EARLY WEDNESDAY THAT THEN MIGRATES WESTWARD
A BIT DURING THE DAY. THIS FOCUS ALONG WITH SOME SPEED CONVERGENCE
ALONG THE COAST LOOKS TO BE ENOUGH FOR SHOWERS TO BEGIN MIGRATING
ONSHORE. NOT IMPOSSIBLE THAT A FEW OF THESE SHOWERS OR SPRINKLES
COULD SURVIVE THE TREK ACROSS THE PENINSULA TO REACH SOME OF OUR
EASTERN AND SOUTHERN ZONES. GOING TO KEEP THE POPS AT OR BELOW 20%
FOR NOW...AND WILL MENTION A FEW SPRINKLES IN THE FORECAST WEDNESDAY
FOR THE SOUTHERN HALF OF THE FORECAST AREA. THOSE SPRINKLES SHOULD
BE GONE BY TOMORROW EVENING...AND AS IT LOOKS NOW...ALTHOUGH A LOT
OF CLOUDS AROUND...THE WEATHER FOR AFTER DARK ON NEW YEARS EVE LOOKS
DRY WITH SEASONABLE TEMPERATURES.
&&
.LONG TERM (THURSDAY THROUGH NEXT TUESDAY)...
ZONAL FLOW ALOFT AND WEAK RIDGING WILL BE IN PLACE TO START THE
PERIOD WITH A REMNANT BOUNDARY DRAPED ACROSS SOUTH FL. THE BOUNDARY
WILL LIFT NORTH OVER THE AREA INTO FRIDAY AS A TROUGH DEVELOPS OVER
THE GULF STREAM JUST OFF THE FL EAST COAST AND A WEAK LOW DEEPENS
OFF OF THE TEXAS COAST IN THE GULF OF MEXICO. THIS WILL ALLOW FOR A
SLIGHT CHANCE OF RAIN WEDNESDAY NIGHT AND THURSDAY. FLOW ALOFT WILL
BECOME SW FOR THE WEEKEND AS WEAK RIDGING BUILDS OVER THE STATE FROM
THE ATLANTIC AND THE LOW OFF OF TEXAS LIFTS NE AND DRAGS A COLD
FRONT INTO THE REGION BY SUNDAY. THE FRONT WILL SETTLE INTO THE AREA
SUNDAY AFTERNOON AND THEN STALL ACROSS THE NORTHERN HALF OF THE
PENINSULA FOR EARLY NEXT WEEK. THIS WILL ALLOW FOR A FEW SHOWERS
MAINLY ACROSS THE NATURE COAST SATURDAY THROUGH SUNDAY...AND INLAND
ACROSS THE AREA MONDAY. TEMPERATURES WILL REMAIN ABOVE NORMAL
THROUGH THE WEEKEND AND FALL A COUPLE OF DEGREES TO CLOSER TO NORMAL
FOR EARLY NEXT WEEK.
&&
.AVIATION...
MVFR TO OCCASIONAL IFR CONDITIONS THIS AFTERNOON FROM KSRQ/KPIE/KTPA
AND KLAL. SOUTH OF THE FRONTAL BAND FROM KPGD TO KRSW WILL CONTINUE
TO SEE PREVAILING VFR CONDITIONS INTO THE EVENING HOURS. GOOD
AGREEMENT AMONG THE DETERMINISTIC AND STATISTICAL GUIDANCE THAT WE
WILL SEE AN EXPANSION OF THE LOWER CLOUDS DURING THE SECOND HALF OF
THE NIGHT INTO WEDNESDAY MORNING. SO ALTHOUGH EVEN THE NORTHERN
TERMINALS MAY SEE A BRIEF WINDOW OF IMPROVEMENT THIS EVENING...GOING
WITH PREVAILING MVFR CIGS FOR ALL TERMINALS AFTER 06Z. IF THE MAV IS
CORRECT THAN PERIODS OF IFR CIGS ARE POSSIBLE. BEST CHANCES TO SEE
ANY FOG/VIS RESTRICTIONS WILL BE DOWN TOWARD KPGD AND KRSW. EXPECT
MVFR CATEGORY CIGS TO HOLD THROUGH MUCH OF THE MORNING AT MANY
SPOTS...IF NOT UNTIL THE END OF THE TAF PERIOD.
&&
.MARINE...
MARINE FORECAST AREA REMAINS DIVIDED WITH IMPACTS ASSOCIATED WITH A
QUASI-STATIONARY FRONTAL SYSTEM DRAPED OVER THE WATERS FROM OFF
HERNANDO BEACH SOUTHWARD TO OFF THE COAST FROM VENICE. MAIN AREA OF
SHOWERS EXTENDS OFF THE COAST OF HOLIDAY AND OUT 100 NM INTO THE
EASTERN GULF OF MEXICO. CONDITIONS EARLY THIS AFTERNOON /2PM/
REPORTS SEAS AROUND 6 FEET WITH A PERIOD OF 5 SECONDS AT BUOY036 112
MILES W-NW OF TAMPA WHILE BUOY03 REPORTS SEAS OF 2 FEET AND A PERIOD
OF 8 SECONDS IN THE CALMER AIRMASS 208 MILES WEST OF NAPLES. NO
FLAGS EXPECTED THROUGH THE PERIOD AND SHOWER ACTIVITY WILL GRADUALLY
DIMINISH TONIGHT.
&&
.FIRE WEATHER...
NO SIGNIFICANT FIRE WEATHER CONCERNS EXPECTED THE NEXT SEVERAL DAYS.
WEAK COLD FRONT WILL EXIT SOUTH OF THE AREA THIS EVENING ALLOWING
SOMEWHAT DRIER AIR TO ARRIVE FROM THE NORTH FOR WEDNESDAY AND
THURSDAY. THEREAFTER...INCREASING TEMPERATURES AND LOW LEVEL
MOISTURE IS EXPECTED FOR THE END OF THE WEEK.
FOG POTENTIAL...
PATCHY FOG IS EXPECTED TO DEVELOP OVERNIGHT...MAINLY TO THE SOUTH OF
THE I-4 CORRIDOR WITH THE BEST CHANCES FOR ANY SIGNIFICANT FOG
OCCURRING FROM AROUND PUNTA GORDA AND SOUTHWARD.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 61 75 60 76 / 40 10 10 10
FMY 65 79 64 80 / 30 20 10 20
GIF 61 76 58 76 / 40 10 10 10
SRQ 63 77 61 77 / 40 10 10 10
BKV 58 74 54 74 / 20 10 20 10
SPG 63 75 61 74 / 40 10 10 10
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/AVIATION/FIRE WX...MROCZKA
LONG TERM...HUBBARD
MARINE...LAMARRE
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
1020 AM EST TUE DEC 30 2014
.DISCUSSION...
FRONTAL BNDRY JUST N OF THE I-4 CORRIDOR HAS STALLED DUE TO A
STUBBORN H100-H70 HI PRES RIDGE OVER THE FL STRAITS. MRNG RAOBS SHOW
DEEP MOISTURE AHEAD OF THE FRONT WITH PWAT VALUES BTWN 1.5"-1.8" AS
KXMR-KTBW RESPECTABLY...BUT DECREASING EITHER SIDE OF THE BNDRY TO
1.2" AT KJAX/KMFL. RUC ANALYSIS SHOWS RESPECTABLE MID/UPR LVL
DYNAMIC SUPPORT ALONG THE FRNTL BNDRY OVER THE GOMEX...BUT LITTLE
OVER CENTRAL FL. LATEST RADAR TREND REFLECTS THIS LACK OF SUPPORT AS
AN AREA OF MODERATE RAIN THAT MOVED ONSHORE OVER TAMPA BAY HAS
WEAKENED INTO A BROAD AREA OF LIGHT STRATIFORM RAIN AS IT APPROACHED
THE FL TURNPIKE.
WHILE THE FRONT HAS STALLED...RUC SHOWS AN H100-H70 N/NW SURGE OVER
THE LWR MS VALLEY THAT SHOULD GIVE IT THE PUSH IT NEEDS TO PLOW THE
RIDGE AXIS OUT OF THE FL STRAITS LATER TODAY. LITTLE IN THE WAY OF
SFC HEATING N OF SR60 AS CLOUD COVER ENTRENCHED WITHIN THE FRONTAL
TROF STREAMS ACRS CENTRAL FL. PRECIP WILL BE SPOTTY AT BEST WITH QPF
VALUES AOB 0.10". FURTHER S...WHILE SUNNY SKIES AND SFC DEWPOINTS IN
THE M/U60S NORMALLY WOULD SUGGEST THE THREAT OF TSRAS...THE LACK OF
ANY SIG DYNAMIC SUPPORT COUPLED WITH A LINGERING SUBSIDENCE
INVERSION IN THE H85-H70 LYR (LAPSE RATES BTWN 3.0-4.0C/KM) SUGGESTS
THE SRN CWA WILL REMAIN DRY.
WILL KNOCK A FEW DEG OF MAX TEMPS FROM BREVARD/OSCEOLA NWD...ALSO
WILL SHAVE POPS BACK A TOUCH ARND LAKE OKEECHOBEE.
&&
.AVIATION...THRU 31/12Z
SFC WNDS: THRU 30/20Z...W/SW 5-8KTS BCMG N. AFT 30/20Z...N 4-7KTS.
VSBYS/WX: THRU 30/20Z...N OF KTIX-KISM...PDS OF MVFR IN -RA/BR...S
OF KTIX-KISM PREVAILING VFR WITH LCL IFR IN BR/FG ENDING BY 30/16Z.
BTWN 30/20Z-31/04Z...N OF KTIX-KISM VFR...S OF KTIX-KISM PDS OF MVFR
IN -RA/BR. AFT 31/04Z...AREAS MVFR BR WITH LCL LIFR FG N OF
KDAB-KISM.
CIGS: THRU 30/17Z...N OF KTIX-KISM PREVAILING BTWN FL015-020 WITH
AREAS LIFR BLO FL005...S OF KTIX-KISM PREVAILING AOA FL120 WITH LCL
LIFR BLO FL004. BTWN 30/17Z-31/04Z...PREVAILING FL040-060 WITH AREAS
MVFR FL020-030. AFT 31/04Z...PREVAILING MVFR FL020-030...N OF
KTIX-KISM AREAS LIFR BLO FL005...S OF KTIX-KISM LCL IFR BTWN
FL005-009.
&&
.MARINE...
RUC ANALYSIS SHOWS TEH FRONTAL TROF EXTENDING FROM THE CENTRAL GOMEX
TO THE NC OUTER BANKS. LATEST SFC OBS INDICATE THE FRONT HAS PUSHED
S OF ST. AUGUSTINE BUT REMAINS N OF BUOY009...FOG/CALM WINDS ALONG
THE COAST BTWN PALM COAST AND NEW SMYRNA BEACH AS OF 14Z SUGGEST THE
BNDRY IS IN THE VCNTY OF THE VOLUSIA/FLAGLER COUNTY LINE.
DESPITE A STUBBORN RIDGE AXIS OVER THE FL STRAITS...THE FRONT WILL
PUSH THRU CENTRAL FL THRU SUNSET...FORCING SFC/BNDRY LYR WINDS TO
VEER FROM W/SW TO DUE NORTH...GENERALLY BTWN 10-15KTS. SEAS AOB 2FT
NEARSHORE AND 2-3FT OFFSHORE...INCREASING TO 2-3FT NEARSHORE AND
3-4FT OFFSHORE AS WINDS SWING ARND TO THE N. NO SIG CHANGES.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...BRAGAW
LONG TERM/IMPACT WX...LASCODY
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
1010 AM EST TUE DEC 30 2014
.UPDATE (REST OF TODAY THROUGH WEDNESDAY)...
15Z WATER VAPOR AND H4 RAP ANALYSIS CONTINUE TO SHOW MUCH OF THE
NATION UNDER A BROAD LONGWAVE TROUGH. THE MOST ENERGETIC FEATURE
WITHIN THIS TROUGH IS A STRONG SHORTWAVE DROPPING SOUTH THROUGH THE
INTERMOUNTAIN WEST WHICH IS PROGGED BY ALL THE NUMERICAL GUIDANCE TO
BECOME A LARGE CUTOFF LOW OVER THE SOUTHWESTERN STATES BEFORE
EJECTING EASTWARD ACROSS THE SOUTHERN/CENTRAL PLAINS LATER IN THE
WEEK. OUR FORECAST AREA RESIDES WITHIN A ZONE OF DEEP LAYER
SOUTHWEST FLOW BETWEEN THE LONGWAVE TROUGH AND AND WEST-EAST
ORIENTED RIDGE ACROSS THE NORTHWEST CARIBBEAN. A PLUME OF SOUTHERN
STREAM MOISTURE IS STILL IN WV IMAGERY RIDGING THIS FLOW OVER THE
EASTERN GULF OF MEXICO AND FL PENINSULA.
AT THE SURFACE...A WEAK COLD FRONT HAS ENTERED THE NORTHERN FLORIDA
PENINSULA AND IS NOW STRETCHED ACROSS THE NATURE COAST ON A SLOW
TREK SOUTHWARD THROUGH THE DAY.
REGIONAL RADARS CONTINUE TO SHOW AN EXPANSION OF THE SHOWERS ALONG
AND AHEAD OF THIS BOUNDARY...AND THIS IS LIKELY RELATED TO SOME
ADDED SYNOPTIC SUPPORT FOR LIFT ASSOCIATED WITH A WEAK/SUBTLE
PASSING SHORTWAVE ALOFT OVER THE NE GULF OF MEXICO. HAVE
SUBSTANTIALLY INCREASED RAIN CHANCES FOR THE MORNING THROUGH
WEST-CENTRAL FLORIDA AS A SOGGY NEXT FEW HOURS NOW APPEARS LIKELY.
FORECAST GRIDS AND TEXT PRODUCTS HAVE BEEN UPDATED.
THE RAIN IS ALSO HELPING LIFT SOME OF THE DENSE FOG SEEN AROUND THE
AREA. FOR LOCATIONS SOUTH OF THE RAIN SHIELD...THE DENSE FOG IS
HOLDING IN LONGER. JUST BEGINNING TO SEE THE EROSION OF THIS FOG DUE
TO DIURNAL MIXING AND VISIBILITIES SHOULD BE IMPROVING QUICKLY INTO
THE LATER MORNING HOURS. WITH ALL THIS IN MIND WILL ALLOW THE DENSE
FOG ADVISORY TO EXPIRE AT 10AM...EVEN THOUGH A FEW SPOTS MAY STILL
TECHNICALLY MEET CRITERIA FOR A BIT LONGER. USING THE LATEST HRRR
FOR TIMING...THE FRONT STILL LOOKS TO ARRIVE AT THE I-4 CORRIDOR
AROUND MIDDAY/EARLY AFTERNOON AND THEN SLOWLY SETTLE SOUTH TO NEAR
PUNTA GORDA AROUND SUNSET. THE ORGANIZATION AND COVERAGE OF SHOWERS
SHOULD BEGIN TO DIMINISH DURING THE SECOND HALF OF THE DAY AS THE
SHORTWAVE INFLUENCE PASSES TO OUR EAST. HOWEVER...THE LOW LEVEL
BOUNDARY FOCUS WILL STILL KEEP THE CHANCE FOR MORE SCT SHOWERS IN
THE FORECAST. ALSO WITH THE FLOW BECOMING MORE AND MORE PARALLEL TO
THE FRONT...THE ACTUALLY BOUNDARY PASSAGE WILL NOT NECESSARILY END
THE CHANCE FOR RAIN AS MANY OF THE GUIDANCE MEMBERS ARE INDICATING
THE BOUNDARY WILL TAKE ON AN INCREASINGLY ANAFRONT CONFIGURATION BY
LATER TODAY WHERE BETTER CHANCES FOR THE CLOUDS AND SHOWERS ARE
ACTUALLY ALONG AND BEHIND THE BOUNDARY.
FOR OUR SOUTHERN ZONES...FOG WILL BE LIFTING BY MIDDAY. YOUR SHOWERS
CHANCES WILL BE INCREASING LATER THIS AFTERNOON AND INTO THE EVENING
AS THE BOUNDARY MAKES IT WAYS SOUTHWARD.
TONIGHT AND WEDNESDAY...THE FRONT STALLS AND BEGINS TO WASH OUT OVER
THE SOUTHERN PENINSULA. THE GUIDANCE MEMBERS ARE ALL STARTING TO
INDICATE THE DEVELOPMENT OF AN INVERTED TROUGH OVER THE GULF STREAM
OFF THE FL EAST COAST DURING THIS TIME. THIS FOCUS ALONG WITH SOME
SPEED CONVERGENCE ALONG THE COAST LOOKS TO BE ENOUGH FOR SHOWERS TO
BEGIN MIGRATING ONSHORE. GOING TO HAVE TO LOOK AT THIS A BIT CLOSER
WITH THE 12Z GUIDANCE AS SOME OF THESE SHOWERS MAY HAVE A CHANCE TO
MIGRATE INLAND ENOUGH TO IMPACT PORTIONS OF POLK/HIGHLANDS COUNTIES
ON WEDNESDAY. WOULD NOT BE A LOT OF RAIN...BUT WOULD NOT BE THE
COMPLETELY DRY FORECAST CURRENTLY IN THE GRIDS. ELSEWHERE WEDNESDAY
STILL LOOKS TO BE MAINLY DRY...HOWEVER PROB NOT A WHOLE LOT OF SUN
AROUND...ESPECIALLY FOR THE I-4 CORRIDOR AND SOUTHWARD.
&&
.AVIATION...
VARYING CONDITIONS OUT THERE THIS MORNING WITH A MIX OF FOG AND
RAIN. ALTHOUGH MANY STATIONS WILL NOT BE PREVAILING LIFR OR
LOWER...PERIODS OF THESE LOW RESTRICTIONS WILL REMAIN POSSIBLE FOR
ALL TERMINALS THROUGH THE MORNING HOURS. IMPROVEMENT WILL OCCUR FOR
THE SECOND HALF OF THE DAY...HOWEVER AT LEAST PERIODS OF MVFR
CONDITIONS SHOULD STILL BE EXPECTED.
&&
.MARINE...
AREAS OF SEA FOG REMAIN OVER THE WATERS THIS MORNING AHEAD OF AN
APPROACHING COLD FRONT. THE FOG HAS BECOME LESS PREVALENT OVER THE
PAST COUPLE OF HOURS...ESPECIALLY OVER TAMPA BAY AND THE GULF WATERS
TO THE WEST OF THE BAY AS SHOWERS HAVE BEEN ONGOING THERE FOR
SEVERAL HOURS. THE SEA FOG IS EXPECTED TO DISSIPATE BY LATE MORNING
OR EARLY AFTERNOON AS THE FRONT SINKS SOUTHWARD. THERE WILL BE A
CHANCE FOR SHOWERS THROUGH THE REST OF THE DAY AS WELL...WHICH COULD
BRIEFLY REDUCE VISIBILITY OVER THE WATERS.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 78 63 75 59 / 90 10 20 10
FMY 82 65 81 63 / 30 20 20 10
GIF 79 62 75 57 / 80 10 20 10
SRQ 79 63 76 60 / 70 10 20 10
BKV 78 59 74 53 / 60 10 10 10
SPG 77 65 74 60 / 90 10 20 10
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
UPDATE/AVIATION...MROCZKA
MARINE...CARLISLE
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
825 AM EST TUE DEC 30 2014
.UPDATE (REST OF TODAY THROUGH WEDNESDAY)...
13Z WATER VAPOR AND H4 RAP ANALYSIS CONTINUE TO SHOW MUCH OF THE
NATION UNDER A BROAD LONGWAVE TROUGH. THE MOST ENERGETIC FEATURE
WITHIN THIS TROUGH IS A STRONG SHORTWAVE DROPPING SOUTH THROUGH THE
INTERMOUNTAIN WEST WHICH IS PROGGED BY ALL THE NUMERICAL GUIDANCE TO
BECOME A LARGE CUTOFF LOW OVER THE SOUTHWESTERN STATES BEFORE
EJECTING EASTWARD ACROSS THE SOUTHERN/CENTRAL PLAINS LATER IN THE
WEEK. OUR FORECAST AREA RESIDES WITHIN A ZONE OF DEEP LAYER
SOUTHWEST FLOW BETWEEN THE LONGWAVE TROUGH AND AND WEST-EAST
ORIENTED RIDGE ACROSS THE NORTHWEST CARIBBEAN. A PLUME OF SOUTHERN
STREAM MOISTURE IS STILL IN WV IMAGERY RIDGING THIS FLOW OVER THE
EASTERN GULF OF MEXICO AND FL PENINSULA.
AT THE SURFACE...A WEAK COLD FRONT HAS ENTERED THE NORTHERN FLORIDA
PENINSULA AND IS NOW STRETCHED ACROSS THE NATURE COAST ON A SLOW
TREK SOUTHWARD THROUGH THE DAY.
REGIONAL RADARS HAVE SHOWN A RAPID EXPANSION OF THE SHOWERS ALONG
AND AHEAD OF THIS BOUNDARY DURING THE PAST FEW HOURS...AND THIS IS
LIKELY RELATED TO SOME ADDED SYNOPTIC SUPPORT FOR LIFT ASSOCIATED
WITH A WEAK/SUBTLE PASSING SHORTWAVE ALOFT OVER THE NE GULF OF
MEXICO. HAVE SUBSTANTIALLY INCREASED RAIN CHANCES FOR THE MORNING
THROUGH WEST-CENTRAL FLORIDA AS A SOGGY NEXT FEW HOURS NOW APPEARS
LIKELY. FORECAST GRIDS AND TEXT PRODUCTS HAVE BEEN UPDATED.
THE RAIN IS ALSO HELPING LIFT SOME OF THE DENSE FOG SEEN AROUND THE
AREA AND WILL BE MAKING DECISIONS ON WHAT TO DO WITH THE DENSE FOG
ADVISORY IN THE NEXT COUPLE OF HOURS. USING THE LATEST HRRR FOR
TIMING...THE FRONT LOOKS TO ARRIVE THE I-4 CORRIDOR AROUND MIDDAY
AND THEN SLOWLY SETTLE SOUTH TO NEAR PUNTA GORDA AROUND SUNSET. THE
ORGANIZATION AND COVERAGE OF SHOWERS SHOULD BEGIN TO DIMINISH DURING
THE SECOND HALF OF THE DAY AS THE SHORTWAVE INFLUENCE PASSES TO OUR
EAST. HOWEVER...THE LOW LEVEL BOUNDARY FOCUS WILL STILL KEEP THE
CHANCE FOR MORE SCT SHOWERS IN THE FORECAST. ALSO WITH THE FLOW
BECOMING MORE AND MORE PARALLEL TO THE FRONT...THE ACTUALLY
BOUNDARY PASSAGE WILL NOT NECESSARILY END THE CHANCE FOR RAIN AS
MANY OF THE GUIDANCE MEMBERS ARE INDICATING THE BOUNDARY WILL TAKE
ON AN INCREASINGLY ANAFRONT CONFIGURATION BY LATER TODAY WHERE
BETTER CHANCES FOR THE CLOUDS AND SHOWERS ARE ACTUALLY ALONG AND
BEHIND THE BOUNDARY.
FOR OUR SOUTHERN ZONES...A COUPLE MORE HOURS WITH THE FOG AND THEN
WE SHOULD BEGIN TO BURN IT OFF. YOUR SHOWERS CHANCES WILL BE
INCREASING THIS AFTERNOON AND INTO THE EVENING AS THE BOUNDARY MAKES
IT WAYS SOUTHWARD.
TONIGHT AND WEDNESDAY...THE FRONT STALLS AND BEGINS TO WASH OUT OVER
THE SOUTHERN PENINSULA. THE GUIDANCE MEMBERS ARE ALL STARTING TO
INDICATE THE DEVELOPMENT OF AN INVERTED TROUGH OVER THE GULF STREAM
OFF THE FL EAST COAST DURING THIS TIME. THIS FOCUS ALONG WITH SOME
SPEED CONVERGENCE ALONG THE COAST LOOKS TO BE ENOUGH FOR SHOWERS TO
BEGIN MIGRATING ONSHORE. GOING TO HAVE TO LOOK AT THIS A BIT CLOSER
WITH THE 12Z GUIDANCE AS SOME OF THESE SHOWERS MAY HAVE A CHANCE TO
MIGRATE INLAND ENOUGH TO IMPACT PORTIONS OF POLK/HIGHLANDS COUNTIES
ON WEDNESDAY. WOULD NOT BE A LOT OF RAIN...BUT WOULD NOT BE THE
COMPLETELY DRY FORECAST CURRENTLY IN THE GRIDS. ELSEWHERE WEDNESDAY
STILL LOOKS TO BE MAINLY DRY...HOWEVER PROB NOT A WHOLE LOT OF SUN
AROUND...ESPECIALLY FOR THE I-4 CORRIDOR AND SOUTHWARD.
&&
.AVIATION...
VARYING CONDITIONS OUT THERE THIS MORNING WITH A MIX OF FOG AND
RAIN. ALTHOUGH MANY STATIONS WILL NOT BE PREVAILING LIFR OR
LOWER...PERIODS OF THESE LOW RESTRICTIONS WILL REMAIN POSSIBLE FOR
ALL TERMINALS THROUGH THE MORNING HOURS. IMPROVEMENT WILL OCCUR FOR
THE SECOND HALF OF THE DAY...HOWEVER AT LEAST PERIODS OF MVFR
CONDITIONS SHOULD STILL BE EXPECTED.
&&
.MARINE...
DENSE SEA FOG WILL BE LOCATED OVER THE NEAR SHORE COASTAL WATERS
SOUTH OF THE COLD FRONT. AS THE COLD FRONT GRADUALLY SINKS SOUTH
TODAY...THE AREA OF SEA FOG WILL BE SINK SOUTH AND DECREASE IN AREAL
COVERAGE...DISSIPATING BY LATE TODAY. WEAK HIGH PRESSURE WILL BUILD
OVER THE WATERS BEHIND THE FRONT THROUGH THE REMAINDER OF THE WEEK.
WINDS WILL BE LESS THAN 15 KNOTS WITH SEAS LESS THAN 4 FEET THROUGH
THE PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 78 63 75 59 / 90 10 20 10
FMY 82 65 81 63 / 30 20 20 10
GIF 79 62 75 57 / 80 10 20 10
SRQ 79 63 76 60 / 70 10 20 10
BKV 78 59 74 53 / 60 10 10 10
SPG 77 65 74 60 / 90 10 20 10
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR
COASTAL CHARLOTTE-COASTAL CITRUS-COASTAL HERNANDO-
COASTAL HILLSBOROUGH-COASTAL LEE-COASTAL LEVY-COASTAL
MANATEE-COASTAL PASCO-COASTAL SARASOTA-DESOTO-HARDEE-
HIGHLANDS-INLAND CHARLOTTE-INLAND HERNANDO-INLAND
HILLSBOROUGH-INLAND LEE-INLAND MANATEE-INLAND PASCO-
INLAND SARASOTA-PINELLAS-POLK.
GULF WATERS...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING
FOR BONITA BEACH TO ENGLEWOOD OUT 20 NM-CHARLOTTE HARBOR AND
PINE ISLAND SOUND-ENGLEWOOD TO TARPON SPRINGS OUT 20
NM-TAMPA BAY WATERS-TARPON SPRINGS TO SUWANNEE RIVER
OUT 20 NM.
&&
$$
UPDATE/AVIATION...MROCZKA
MARINE...CARLISLE
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
614 AM EST TUE DEC 30 2014
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE AREA TODAY INTO FRIDAY...BEFORE
MOVING INTO THE ATLANTIC BY SATURDAY. A COASTAL TROUGH WILL DEVELOP
SATURDAY AND LIFT NORTH OF THE REGION BY SUNDAY. A COLD FRONT WILL
THEN PASS OFF THE COAST EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MESOSCALE UPDATE...THE DENSE FOG IN THE SAVANNAH AND BEAUFORT
AREAS HAS LIFTED BACK INTO A VERY LOW STRATUS DECK. WEBCAMS AND
SURFACE OBSERVATIONS INDICATE VSBYS HAVE IMPROVED TO 1-2 MILES.
HOWEVER...LOCALLY DENSE FOG IS STILL LIKELY NEAR BODIES OF WATER
AND OTHER LOW LYING AREAS. AN AREA OF DENSE FOG IS TRYING TO NOSE
INTO PARTS OF JENKINS-CANDLER-EVANS-TATTNALL AND BULLOCH. WITH
SUNRISE APPROACHING...PREFER TO HANDLE THIS WITH A SPECIAL WEATHER
STATEMENT. HOWEVER...A DENSE FOG ADV CAN NOT BE RULED OUT. SURFACE
TROUGH/SECONDARY COLD SURGE IS WORKING ITS WAY SOUTH OF THE SOUTH
SANTEE RIVER AND WILL CROSS THE I-26 CORRIDOR THROUGH SUNRISE.
HIGHS WILL LIKELY OCCUR DAY TIME HIGHS WILL LIKELY OCCUR IN THE
7-9AM TIME FRAME BEFORE TEMPERATURES HOLD STEADY THEN POSSIBLY
FALL. ADJUSTED HOURLY TEMPERATURES ACROSS THE CHARLESTON TRI-
COUNTY AREA A BIT.
TODAY...LOW CONFIDENCE FORECAST TODAY. THE COLD FRONT AND
ASSOCIATED FRONTAL WAVE ARE NOW WELL OFFSHORE WITH A NORTHERLY
LOW-LEVEL FLOW DOMINATING IN ITS WAKE. A WEAK POST FRONTAL SURFACE
TROUGH DELINEATING A SURGE OF COOLER AIR WILL APPROACH THE
CHARLESTON AREA BY SUNRISE...THE SAVANNAH AREA BY MID/LATE MORNING
AND FINALLY CLEARING THE ALTAMAHA RIVER BY LATE AFTERNOON. MODELS
SHOW A TRANSIENT HYBRID WEDGE SETTING UP ACROSS MAINLY THE CENTRAL
AND NORTHERN PORTIONS OF THE FORECAST AREA IN THE WAKE OF THE
TROUGH AS 290K ISENTROPIC ASSENT BRIEFLY INTENSIFIES ATOP THE LOW-
LEVEL POST FRONTAL WEDGING PATTERN. THIS PATTERN WILL ESSENTIALLY
REINFORCE THE WIDESPREAD LOW CLOUDS AND PATCHY DRIZZLE THAT ARE
ALREADY IN PLACE ACROSS THE LOWCOUNTRY AND COASTAL EMPIRE FOR A
GOOD PORTION OF THE DAY. THE TEMPERATURE FORECAST IS PROVING TO BE
EXTREMELY CHALLENGING AS A RESULT AND ASSUMES THE TRANSIENT WEDGE
ACTUALLY DEVELOPS AS DEPICTED IN THE HIGHER RESOLUTION DATA SETS.
DAILY HIGHS /7AM-6PM/ WILL LIKELY OCCUR BY MID-MORNING ACROSS THE
CHARLESTON TRI-COUNTY AREA AND EARLY AFTERNOON ACROSS THE
REMAINDER OF SOUTHEAST SOUTH CAROLINA AND SOUTHEAST GEORGIA.
TEMPERATURES WILL LIKELY HOLD STEADY OR SLOWLY FALL NORTH THE
SAVANNAH RIVER AS THE WEDGE BRIEFING INTENSIFIES. HIGHS WILL RANGE
MID 50S NORTH...UPPER 50/NEAR 60 CENTRAL TO THE LOWER-MID 60S
SOUTH. UTILIZE A 30/30/30 BLEND OF RAP/H3R AND GLAMP DATA TO
CONSTRUCT HOURLY TEMPERATURES. SINCE THIS IS A VERY LOW CONFIDENCE
FORECAST...CHANGES--SOME POSSIBLY SIGNIFICANT--WILL LIKELY BE
NEEDED THROUGHOUT THE DAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
TONIGHT...THE TRANSIENT HYBRID WEDGE WILL QUICKLY BREAKDOWN THIS
EVENING AS HIGH PRESSURE FINALLY BRIDGES THE SOUTHERN APPALACHIANS
AND BECOMES MORE DOMINATE ACROSS THE SOUTHEAST STATES. A GOOD BIT
OF CLOUD COVER WILL LINGER THROUGH THE NIGHT WITH THE POTENTIAL
FOR SOME CLEARING TO OCCUR ACROSS THE NORTH AFTER 3 AM. WILL HAVE
TO WATCH FOR SOME FOG TO DEVELOP AFTER MIDNIGHT...BUT THIS DOES
NOT LOOK SIGNIFICANT AT THIS TIME. LOWS WILL RANGE FROM THE MID-
UPPER 30S INTERIOR NORTH WHERE THE BETTER CHANCES FOR CLEARING
WILL OCCUR WITH UPPER 30S TO LOWER 40S ELSEWHERE...EXCEPT MID 40S
ALONG THE GEORGIA COAST WHERE ONSHORE WINDS WILL MODERATE
TEMPERATURES A BIT.
WEDNESDAY AND THURSDAY...EXPANSIVE SURFACE HIGH PRESSURE WILL
BE GRADUALLY WEAKENING AS IT SLIPS TOWARD THE EAST COAST UNDER
RELATIVELY ZONAL FLOW ALOFT. EXPECT DRY CONDITIONS TO PREVAIL
WEDNESDAY AND THURSDAY WITHIN THIS PATTERN. TEMPERATURES
WEDNESDAY WILL BE A FEW DEGREES COOLER THAN NORMAL...PEAKING IN THE
MID TO UPPER 50S DURING THE AFTERNOON AND FALLING INTO THE LOW 30S
NORTH TO UPPER 30S COAST AND SOUTH OVERNIGHT. NORTH FLOW WEAKENS
ON THURSDAY AS THE CENTER OF THE SURFACE HIGH PASSES DIRECTLY OVER
THE REGION...AND WITH SUBTLE RIDGING BUILDING UP FROM THE
BAHAMAS...HIGH TEMPERATURES WILL MODERATE TOWARD SEASONAL NORMALS
IN THE UPPER 50S TO LOWER 60S. A GRADUALLY IMPROVING TAP INTO GULF
MOISTURE LATE THURSDAY WILL SUPPORT INCREASING CLOUDS...WITH LOW
TEMPERATURES A FEW DEGREES MILDER IN THE UPPER 30S INLAND TO LOW
40S CLOSER TO THE COAST.
FRIDAY...AN UPPER LEVEL CUT OFF LOW WILL MOVE FROM THE SOUTHWEST
STATES INTO THE SOUTHERN PLAINS...PROVIDING THE ENERGY TO DEVELOP
A WAVE OF LOW PRESSURE ACROSS THE WESTERN GULF LATE IN THE DAY.
THE SOUTHEAST STATES WILL REMAIN ON THE PERIPHERY OF ATLANTIC HIGH
PRESSURE...WHERE SHORTWAVE ENERGY TRACKING UP FROM THE GULF OF
MEXICO WILL SUPPORT THE GRADUAL AMPLIFICATION OF A COASTAL TROUGH.
NUMERICAL MODEL SOLUTIONS ARE INDICATING SUFFICIENT ISENTROPIC
ASCENT BETWEEN THE COASTAL TROUGH AND A DEVELOPING INLAND WEDGE
TO GENERATE ISOLATED TO SCATTERED RAIN...WITH BEST COVERAGE
ACROSS NORTHERN AND INLAND AREAS. TEMPERATURES COULD BE A DEGREE
OR TWO COOLER THAN THE PREVIOUS DAY GIVEN THE INCREASING CLOUD
COVER...YET STILL RANGE NEAR SEASONAL NORMALS IN THE UPPER 50S TO
LOW 60S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
FRIDAY NIGHT THROUGH SUNDAY...A TRANSIENT INLAND WEDGE/COASTAL
TROUGH PATTERN WILL BE IN PLACE THROUGH EARLY SATURDAY...BEFORE
THE COASTAL TROUGH QUICKLY LIFTS NORTH OF THE REGION AHEAD OF AN
APPROACHING COLD FRONT FROM THE WEST. THE CUT OFF LOW ACROSS THE
SOUTHERN PLAINS WILL DAMPEN AND LIFT NORTHEAST INTO THE OHIO
VALLEY ON SATURDAY. THE ASSOCIATED SURFACE LOW WILL PULL INTO THE
NEW ENGLAND STATES SUNDAY...WITH ITS TRAILING COLD FRONT
PROGRESSING THROUGH THE MID ATLANTIC AND SOUTHEAST STATES BY
SUNDAY AFTERNOON. HIGH TEMPERATURES WILL SURGE INTO THE 60S TO
AROUND 70 DEGREES SATURDAY AND SUNDAY WITHIN WARM SOUTHERLY FLOW
AHEAD OF THE FRONT...WHILE SCATTERED SHOWERS ARE POSSIBLE SATURDAY
THROUGH SUNDAY AFTERNOON. PREFER TO REMAIN RATHER CONSERVATIVE
WITH RAIN CHANCES AT THIS POINT...CONSIDERING THE SOUTHERN END OF
THE FRONT WILL RUN INTO THE PERIPHERY OF THE SUBTROPICAL RIDGE AND
BECOME PARALLEL TO FLOW ALOFT.
SUNDAY NIGHT THROUGH TUESDAY...SURFACE HIGH PRESSURE WILL BUILD IN
THE WAKE OF THE DEPARTING COLD FRONT EARLY NEXT WEEK...EVENTUALLY
SETTLING TO THE NORTH OF THE AREA. RAIN FREE CONDITIONS WILL
PREVAIL. TEMPERATURES ARE EXPECTED TO RETURN TO SEASONAL
NORMALS...POSSIBLY COOLER IF A WEDGE PATTERN CAN SET UP TOWARD THE
END OF THE FORECAST PERIOD.
&&
.AVIATION /11Z TUESDAY THROUGH SATURDAY/...
CIGS WILL REMAIN BELOW ALTERNATE MINIMUMS THROUGH 14-15Z WITH CIGS
RISING THEREAFTER. EXPECT MVFR CIGS TO RETURN TO KSAV BY 16Z WHICH
WILL REMAIN IN PLACE THROUGH THE REMAINDER OF THE 12Z TAF PERIOD.
AT KCHS...CIGS WILL BE SLOWER TO RISE WITH IFR CIGS RETURNING BY
17-18Z. THESE CONDITIONS WILL LINGER THROUGH 12Z WEDNESDAY.
EXTENDED AVIATION OUTLOOK...VFR CONDITIONS WILL PREVAIL WEDNESDAY
AND THURSDAY. CHANCES FOR FLIGHT RESTRICTIONS INCREASE INTO THE
WEEKEND AS THE NEXT SYSTEM IMPACTS THE REGION.
&&
.MARINE...
TODAY...CEILINGS OF 100 FT AT THE HILTON HEAD AIRPORT AND WEBCAMS
IN THE SAVANNAH RIVER AS WELL AS TYBEE ISLAND SUGGEST SEA FOG IS
IN PLACE ACROSS THE COASTAL WATERS THIS MORNING. IT IS UNCLEAR
EXACTLY HOW WIDESPREAD THE FOG IS...BUT RAP VISIBILITIES DATA
SUGGEST ITS PROBABLY PRETTY WIDESPREAD. WFO JAX RECENTLY RELAYED
THAT THE BAR PILOTS OUT OF SAINT SIMMONS ARE REPORTING IMPROVED
VSBYS OVER THE PAST HOUR...BUT THE SHELF WATERS OFF TYBEE ISLAND
ARE SEVERAL DEGREES COOLER. PREFER TO HOLD THE MARINE DENSE FOG
ADVISORY FOR THE GEORGIA NEARSHORE AND BEAUFORT COUNTY WATERS
UNTIL 8 AM...OR AT LEAST UNTIL CONDITIONS CAN BE BETTER EVALUATED
ON COASTAL WEBCAMS AS THE SUN RISES. OTHERWISE...NORTH WINDS WILL
INCREASE TO 10-15 KT TODAY WITH SEAS 1-3 FT.
TONIGHT...WINDS WILL INCREASE A BIT AS THE PRESSURE GRADIENT
INDUCED BY HIGH PRESSURE BUILDING IN FROM THE WEST TIGHTENS.
EXPECT WINDS OF 15-20 KT WITH SEAS 2-3 FT NEARSHORE...4-5 FT
OFFSHORE.
WEDNESDAY THROUGH SATURDAY...THE PRESSURE GRADIENT WILL REMAIN
RELATIVELY TIGHT INTO WEDNESDAY MORNING ON THE PERIPHERY OF HIGH
PRESSURE BUILDING FROM THE WEST. MARGINAL SMALL CRAFT ADVISORY
WINDS IN GUSTS TO 25 KT COULD LINGER ACROSS THE OFFSHORE GEORGIA
WATERS...BEFORE CONDITIONS SLOWLY IMPROVE AS THE DAY PROGRESSES.
THE SURFACE HIGH WILL THEN STEADILY TRACK EAST AND ALLOW THE
GRADIENT TO RELAX TOWARD THE END OF THE WEEK. A COASTAL TROUGH
WILL DEVELOP LATE FRIDAY INTO SATURDAY...WITH INCREASING SOUTHERLY
FLOW IN IT WAKE.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR AMZ352-354.
&&
$$
ST
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
409 AM EST TUE DEC 30 2014
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE AREA TODAY INTO FRIDAY...BEFORE
MOVING INTO THE ATLANTIC BY SATURDAY. A COASTAL TROUGH WILL DEVELOP
SATURDAY AND LIFT NORTH OF THE REGION BY SUNDAY. A COLD FRONT WILL
THEN PASS OFF THE COAST EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
THROUGH SUNRISE...STRATUS BUILD DOWN IS IN PROGRESS WITH BKN-OVC
CLOUDY LAYERS OF 100-300 FT BEGINNING TO LOWER TO THE SURFACE.
ALREADY SEEING A FEW SITES WITH VISIBILITIES LESS THAN 1/2 MILE AND
TRENDS ARE BEING WATCHED FOR THE DEVELOPMENT OF DENSE FOG. VSBYS
AND WEBCAMS IN THE BEAUFORT AND SAVANNAH AREAS INDICATE THE FOG IS
QUICKLY BECOMING DENSE AND WIDESPREAD ENOUGH FOR A DENSE FOG
ADVISORY. AN ADVISORY HAS BE ISSUED FOR COASTAL COLLETON-BEAUFORT-
INLAND JASPER-COASTAL JASPER-INLAND CHATHAM AND COASTAL CHATHAM
UNTIL 9 AM. IT IS UNCLEAR HOW WIDESPREAD THE DENSE FOG WILL BECOME
ELSEWHERE...ESPECIALLY GIVEN WINDS ARE AVERAGING 5-10 MPH...BUT
THE ADVISORY WILL BE ADJUSTED TEMPORALLY OR SPATIALLY AS NEEDED.
TODAY...LOW CONFIDENCE FORECAST TODAY. THE COLD FRONT AND
ASSOCIATED FRONTAL WAVE ARE NOW WELL OFFSHORE WITH A NORTHERLY
LOW-LEVEL FLOW DOMINATING IN ITS WAKE. A WEAK POST FRONTAL SURFACE
TROUGH DELINEATING A SURGE OF COOLER AIR WILL APPROACH THE
CHARLESTON AREA BY SUNRISE...THE SAVANNAH AREA BY MID-MORNING AND
FINALLY CLEARING THE ALTAMAHA RIVER BY LATE AFTERNOON. MODELS SHOW
A TRANSIENT HYBRID WEDGE SETTING UP ACROSS MAINLY THE CENTRAL AND
NORTHERN PORTIONS OF THE FORECAST AREA IN THE WAKE OF THE TROUGH
AS 290K ISENTROPIC ASSENT BRIEFLY INTENSIFIES ATOP THE LOW-LEVEL
POST FRONTAL WEDGING PATTERN. THIS PATTERN WILL ESSENTIALLY
REINFORCE THE WIDESPREAD LOW CLOUDS AND PATCHY DRIZZLE THAT ARE
ALREADY IN PLACE ACROSS THE LOWCOUNTRY AND COASTAL EMPIRE FOR A
GOOD PORTION OF THE DAY. THE TEMPERATURE FORECAST IS PROVING TO BE
EXTREMELY CHALLENGING AS A RESULT AND ASSUMES THE TRANSIENT WEDGE
ACTUALLY DEVELOPS AS DEPICTED IN THE HIGHER RESOLUTION DATA SETS.
DAILY HIGHS /7AM-6PM/ WILL LIKELY OCCUR BY MID-MORNING ACROSS THE
CHARLESTON TRI-COUNTY AREA AND EARLY AFTERNOON ACROSS THE
REMAINDER OF SOUTHEAST SOUTH CAROLINA AND SOUTHEAST GEORGIA.
TEMPERATURES WILL LIKELY HOLD STEADY OR SLOWLY FALL NORTH THE
SAVANNAH RIVER AS THE WEDGE BRIEFING INTENSIFIES. HIGHS WILL RANGE
MID 50S NORTH...UPPER 50/NEAR 60 CENTRAL TO THE LOWER-MID 60S
SOUTH. UTILIZE A 30/30/30 BLEND OF RAP/H3R AND GLAMP DATA TO
CONSTRUCT HOURLY TEMPERATURES. SINCE THIS IS A VERY LOW CONFIDENCE
FORECAST...CHANGES--SOME POSSIBLY SIGNIFICANT--WILL LIKELY BE
NEEDED THROUGHOUT THE DAY.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY/...
TONIGHT...THE TRANSIENT HYBRID WEDGE WILL QUICKLY BREAKDOWN THIS
EVENING AS HIGH PRESSURE FINALLY BRIDGES THE SOUTHERN APPALACHIANS
AND BECOMES MORE DOMINATE ACROSS THE SOUTHEAST STATES. A GOOD BIT
OF CLOUD COVER WILL LINGER THROUGH THE NIGHT WITH THE POTENTIAL
FOR SOME CLEARING TO OCCUR ACROSS THE NORTH AFTER 3 AM. WILL HAVE
TO WATCH FOR SOME FOG TO DEVELOP AFTER MIDNIGHT...BUT THIS DOES
NOT LOOK SIGNIFICANT AT THIS TIME. LOWS WILL RANGE FROM THE MID-
UPPER 30S INTERIOR NORTH WHERE THE BETTER CHANCES FOR CLEARING
WILL OCCUR WITH UPPER 30S TO LOWER 40S ELSEWHERE...EXCEPT MID 40S
ALONG THE GEORGIA COAST WHERE ONSHORE WINDS WILL MODERATE
TEMPERATURES A BIT.
WEDNESDAY AND THURSDAY...EXPANSIVE SURFACE HIGH PRESSURE WILL
BE GRADUALLY WEAKENING AS IT SLIPS TOWARD THE EAST COAST UNDER
RELATIVELY ZONAL FLOW ALOFT. EXPECT DRY CONDITIONS TO PREVAIL
WEDNESDAY AND THURSDAY WITHIN THIS PATTERN. TEMPERATURES
WEDNESDAY WILL BE A FEW DEGREES COOLER THAN NORMAL...PEAKING IN THE
MID TO UPPER 50S DURING THE AFTERNOON AND FALLING INTO THE LOW 30S
NORTH TO UPPER 30S COAST AND SOUTH OVERNIGHT. NORTH FLOW WEAKENS
ON THURSDAY AS THE CENTER OF THE SURFACE HIGH PASSES DIRECTLY OVER
THE REGION...AND WITH SUBTLE RIDGING BUILDING UP FROM THE
BAHAMAS...HIGH TEMPERATURES WILL MODERATE TOWARD SEASONAL NORMALS
IN THE UPPER 50S TO LOWER 60S. A GRADUALLY IMPROVING TAP INTO GULF
MOISTURE LATE THURSDAY WILL SUPPORT INCREASING CLOUDS...WITH LOW
TEMPERATURES A FEW DEGREES MILDER IN THE UPPER 30S INLAND TO LOW
40S CLOSER TO THE COAST.
FRIDAY...AN UPPER LEVEL CUT OFF LOW WILL MOVE FROM THE SOUTHWEST
STATES INTO THE SOUTHERN PLAINS...PROVIDING THE ENERGY TO DEVELOP
A WAVE OF LOW PRESSURE ACROSS THE WESTERN GULF LATE IN THE DAY.
THE SOUTHEAST STATES WILL REMAIN ON THE PERIPHERY OF ATLANTIC HIGH
PRESSURE...WHERE SHORTWAVE ENERGY TRACKING UP FROM THE GULF OF
MEXICO WILL SUPPORT THE GRADUAL AMPLIFICATION OF A COASTAL TROUGH.
NUMERICAL MODEL SOLUTIONS ARE INDICATING SUFFICIENT ISENTROPIC
ASCENT BETWEEN THE COASTAL TROUGH AND A DEVELOPING INLAND WEDGE
TO GENERATE ISOLATED TO SCATTERED RAIN...WITH BEST COVERAGE
ACROSS NORTHERN AND INLAND AREAS. TEMPERATURES COULD BE A DEGREE
OR TWO COOLER THAN THE PREVIOUS DAY GIVEN THE INCREASING CLOUD
COVER...YET STILL RANGE NEAR SEASONAL NORMALS IN THE UPPER 50S TO
LOW 60S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
FRIDAY NIGHT THROUGH SUNDAY...A TRANSIENT INLAND WEDGE/COASTAL
TROUGH PATTERN WILL BE IN PLACE THROUGH EARLY SATURDAY...BEFORE
THE COASTAL TROUGH QUICKLY LIFTS NORTH OF THE REGION AHEAD OF AN
APPROACHING COLD FRONT FROM THE WEST. THE CUT OFF LOW ACROSS THE
SOUTHERN PLAINS WILL DAMPEN AND LIFT NORTHEAST INTO THE OHIO
VALLEY ON SATURDAY. THE ASSOCIATED SURFACE LOW WILL PULL INTO THE
NEW ENGLAND STATES SUNDAY...WITH ITS TRAILING COLD FRONT
PROGRESSING THROUGH THE MID ATLANTIC AND SOUTHEAST STATES BY
SUNDAY AFTERNOON. HIGH TEMPERATURES WILL SURGE INTO THE 60S TO
AROUND 70 DEGREES SATURDAY AND SUNDAY WITHIN WARM SOUTHERLY FLOW
AHEAD OF THE FRONT...WHILE SCATTERED SHOWERS ARE POSSIBLE SATURDAY
THROUGH SUNDAY AFTERNOON. PREFER TO REMAIN RATHER CONSERVATIVE
WITH RAIN CHANCES AT THIS POINT...CONSIDERING THE SOUTHERN END OF
THE FRONT WILL RUN INTO THE PERIPHERY OF THE SUBTROPICAL RIDGE AND
BECOME PARALLEL TO FLOW ALOFT.
SUNDAY NIGHT THROUGH TUESDAY...SURFACE HIGH PRESSURE WILL BUILD IN
THE WAKE OF THE DEPARTING COLD FRONT EARLY NEXT WEEK...EVENTUALLY
SETTLING TO THE NORTH OF THE AREA. RAIN FREE CONDITIONS WILL
PREVAIL. TEMPERATURES ARE EXPECTED TO RETURN TO SEASONAL
NORMALS...POSSIBLY COOLER IF A WEDGE PATTERN CAN SET UP TOWARD THE
END OF THE FORECAST PERIOD.
&&
.AVIATION /07Z TUESDAY THROUGH SATURDAY/...
LIFR CIGS WILL LINGER AT BOTH TERMINALS THROUGH SUNRISE. CIGS WILL
REMAIN BELOW ALTERNATE MINIMUMS AND COULD DROP BELOW AIRPORT
MINIMUMS OVER THE NEXT FEW HOURS. FOG COULD BECOME A PROBLEM
LATE...BUT THE LOW CIGS WILL BE THE PRIMARY ISSUE UNLESS THE
STRATUS DECKS REACH THE GROUND RESULTING IN DENSE FOG. LOW
CONFIDENCE IN THIS SCENARIO RIGHT NOW. CIGS WILL LIFT EVER SO
SLOWLY AFTER SUNRISE...BUT SHOULD RISE ABOVE ALTERNATE MINIMUMS
13-14Z...ALTHOUGH STAYING IN IFR. MVFR SHOULD RETURN BY 16-17Z AND
LINGER THE REST OF THE 06Z TAF PERIOD.
EXTENDED AVIATION OUTLOOK...VFR CONDITIONS WILL PREVAIL WEDNESDAY
AND THURSDAY. CHANCES FOR FLIGHT RESTRICTIONS INCREASE INTO THE
WEEKEND AS THE NEXT SYSTEM IMPACTS THE REGION.
&&
.MARINE...
TODAY...CEILINGS OF 100 FT AT THE HILTON HEAD AIRPORT AND WEBCAMS
IN THE SAVANNAH RIVER AS WELL AS TYBEE ISLAND SUGGEST SEA FOG IS
IN PLACE ACROSS THE COASTAL WATERS THIS MORNING. IT IS UNCLEAR
EXACTLY HOW WIDESPREAD THE FOG IS...BUT RAP VISIBILITIES DATA
SUGGEST ITS PROBABLY PRETTY WIDESPREAD. WFO JAX RECENTLY RELAYED
THAT THE BAR PILOTS OUT OF SAINT SIMMONS ARE REPORTING IMPROVED
VSBYS OVER THE PAST HOUR...BUT THE SHELF WATERS OFF TYBEE ISLAND
ARE SEVERAL DEGREES COOLER. PREFER TO HOLD THE MARINE DENSE FOG
ADVISORY FOR THE GEORGIA NEARSHORE AND BEAUFORT COUNTY WATERS
UNTIL 8 AM...OR AT LEAST UNTIL CONDITIONS CAN BE BETTER EVALUATED
ON COASTAL WEBCAMS AS THE SUN RISES. OTHERWISE...NORTH WINDS WILL
INCREASE TO 10-15 KT TODAY WITH SEAS 1-3 FT.
TONIGHT...WINDS WILL INCREASE A BIT AS THE PRESSURE GRADIENT
INDUCED BY HIGH PRESSURE BUILDING IN FROM THE WEST TIGHTENS.
EXPECT WINDS OF 15-20 KT WITH SEAS 2-3 FT NEARSHORE...4-5 FT
OFFSHORE.
WEDNESDAY THROUGH SATURDAY...THE PRESSURE GRADIENT WILL REMAIN
RELATIVELY TIGHT INTO WEDNESDAY MORNING ON THE PERIPHERY OF HIGH
PRESSURE BUILDING FROM THE WEST. MARGINAL SMALL CRAFT ADVISORY
WINDS IN GUSTS TO 25 KT COULD LINGER ACROSS THE OFFSHORE GEORGIA
WATERS...BEFORE CONDITIONS SLOWLY IMPROVE AS THE DAY PROGRESSES.
THE SURFACE HIGH WILL THEN STEADILY TRACK EAST AND ALLOW THE
GRADIENT TO RELAX TOWARD THE END OF THE WEEK. A COASTAL TROUGH
WILL DEVELOP LATE FRIDAY INTO SATURDAY...WITH INCREASING SOUTHERLY
FLOW IN IT WAKE.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR GAZ118-119.
SC...DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR SCZ047>049-
051.
MARINE...DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR AMZ352-354.
&&
$$
ST/WMS
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
129 AM EST TUE DEC 30 2014
.SYNOPSIS...
A COLD FRONT WILL MOVE SOUTHEAST INTO THE ATLANTIC EARLY TONIGHT AND
PUSH FURTHER OFFSHORE OVERNIGHT. HIGH PRESSURE WILL BUILD INTO THE
AREA TUESDAY INTO FRIDAY...BEFORE MOVING INTO THE ATLANTIC BY
SATURDAY. A COASTAL TROUGH WILL DEVELOP EARLY THIS WEEKEND THEN
LIFT NORTH OF THE REGION ON SUNDAY. A COLD FRONT WILL THEN PASS
OFF THE COAST EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
WEAK COLD FRONT HAS CLEARED THE GEORGIA COAST WITH A PRONOUNCED
POST-FRONTAL SURFACE TROUGH DROPPING SOUTH. THE TROUGH HAS PASSED
THE CHARLESTON AIRPORT AND WILL CONTINUE TO MOVE SLOWLY SOUTH
THROUGH SUNRISE. LOW STRATUS AND EVENTUALLY FOG WILL AFFECT THE
REGION OVERNIGHT WITH OCCASIONAL LIGHT DRIZZLE. SKIES HAVE CLEARED
BRIEFLY ACROSS ALLENDALE COUNTY AND DENSE RADIATION FOG HAS
QUICKLY DEVELOPED. ITS UNCLEAR HOW LONG THE DENSE FOG WILL
LAST...BUT IT MAY BE ANOTHER 1-2 HOURS BEFORE LOW CLOUDS FILL IN
FROM THE NORTH. IN FACT...CLEARING AND DENSE FOG COULD OCCUR
ACROSS MUCH OF THE FAR WESTERN ZONES FOR THE NEXT FEW HOURS. WILL
WATCH TRENDS CAREFULLY. OTHERWISE...DRIZZLE AND EXTENSIVE CLOUD
COVER WILL PERSIST. IT IS UNCLEAR HOW STRONG POST-FRONTAL STRATUS
BUILD DOWN WILL BE...BUT THERE IS A POTENTIAL FOR SOME DENSE FOG.
MADE ADJUSTMENTS TO CLOUD COVER...FOG COVERAGE AND INTRODUCED
AREAS OF DRIZZLE INTO THE FORECAST FOR THE MIDNIGHT UPDATE. THE
REST OF THE FORECAST IS OKAY.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY/...
TUESDAY AND TUESDAY NIGHT...NEARLY ZONAL FLOW WILL PREVAIL ALOFT AS
A COLD FRONT SLIPS OFF SHORE. BACK TO THE WEST...CONFLUENT FLOW
ALOFT WILL HELP TO FORCE AN IMPRESSIVE 1058 MB HIGH OVER THE
NORTHERN ROCKIES THAT WILL BUILD INTO THE FORECAST AREA THROUGH THE
DAY. FOLLOWING LOW LEVEL THETA E FIELDS...THE LEADING EDGE OF THE
COOLER AIR BEHIND THE FRONT AND THE EXTENT OF THE STRONG SURFACE
HIGH WILL NOT OOZE INTO THE AREA UNTIL LATER IN THE DAY ON TUESDAY
AND POSSIBLY EVEN INTO THE EVENING. AHEAD OF THIS THETA E
GRADIENT...RESIDUAL MOISTURE IN THE LOWEST 3-4K FT OF THE
ATMOSPHERE SHOWS UP WELL IN MODEL TIME HEIGHTS AND CROSS SECTIONS.
THIS SHOULD MANIFEST ITSELF IN THE FORM OF EXTENSIVE STRATUS
ACROSS THE FORECAST AREA FOR MUCH OF THE DAY. IN FACT...WE MAY NOT
SEE ANY CLEARING IN THE TRI-COUNTY REGION UNTIL LATE IN THE
AFTERNOON. THIS WILL HELP KEEP TEMPERATURES AT BAY DESPITE THE
LATER ARRIVAL OF THE COOLER AIR. LOOK FOR HIGHS IN THE MID/UPPER
50S FURTHER NORTH...AND LOW 60S FURTHER TO THE SOUTH. SOME OF THE
MODELS ARE WRINGING OUT SOME MEASURABLE PRECIPITATION IN THE
MORNING DESPITE THE LACK OF FORCING AND RELATIVELY SHALLOW MOIST
LAYER. HAVE KEPT THE FORECAST DRY. OVERNIGHT...COOL NORTHERLY FLOW
WILL SETTLE IN AS THE LOW LEVELS START TO DRY OUT. THE FORECAST IS
DRY AND FEATURES LOWS FALLING INTO THE UPPER 30S NORTH...LOW 40S
FURTHER SOUTH FOR COASTAL SOUTHEAST GEORGIA.
WEDNESDAY THROUGH THURSDAY...ZONAL FLOW WILL PREVAIL ALOFT AS
EXPANSIVE BUT WEAKENING HIGH PRESSURE BUILDS IN FROM THE WEST. WE
MAY BE DEALING WITH A DECENT AMOUNT OF JET-INDUCED HIGH CLOUDS ON
WEDNESDAY...BUT A COLUMN THAT IS OVERALL VERY DRY WILL KEEP THE
FORECAST RAIN FREE THROUGH THURSDAY. TEMPERATURES WILL BE ON THE
COOL SIDE WEDNESDAY...RUNNING ABOUT 4 DEGREES BELOW NORMAL...THEN
RIGHT AROUND NORMAL ON THURSDAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
THE EXPANSIVE SURFACE HIGH WILL STEADILY SHIFT OVER GEORGIA AND
THE CAROLINAS BY FRIDAY...BEFORE MOVING INTO THE ATLANTIC WATERS
SATURDAY. A STRONG CUT OFF LOW OVER THE DESERT SOUTHWEST FRIDAY WILL
EJECT INTO THE SOUTHERN PLAINS OVER THE WEEKEND AND THEN DAMPEN
AS IT MOVE INTO THE UPPER GULF COAST REGION BY LATE WEEKEND. CLOUDS
WILL BE ON THE INCREASE THURSDAY NIGHT AS A SHORT WAVES TRAVERSES
INTO THE REGION ATOP A LARGE SUBTROPICAL RIDGE OVER FLORIDA AND
THE CARIBBEAN. THIS DISTURBANCE MAY PRODUCE SOME SPOTTY LIGHT RAINS
ON FRIDAY BUT CERTAINLY NOT SIGNIFICANT AS PRECIP IS LIKELY TO
EVAPORATE IN DRY LAYERS BELOW 10 KFT. A SLIGHT CHANCE POP LOOKS QUITE
SUFFICIENT. STEADIER RAINS ACROSS NORTH GEORGIA AND THE WESTERN
CAROLINAS MAY BEGIN TO ANCHOR A WEDGE ON SATURDAY WITH GLOBAL
MODELS DIFFERING ON SURFACE PATTERNS. THE WEEKEND LOOKS A BIT
UNSETTLED WITH PLENTY OF CLOUDS MOST AREAS AND MAINLY LOW END CHANCE
POPS AS THE UPPER WAVE FLATTENS SIGNIFICANTLY LATE IN THE WEEKEND.
SUNDAY APPEARS TO BE THE WARMER OF THE DAYS AFTER WE TRENDED DOWN A
GOOD BIT ON TEMPS NORTHERN ZONES SATURDAY. A COLD FRONT SHOULD MOVE
OFF THE COAST EARLY NEXT WEEK.
&&
.AVIATION /07Z TUESDAY THROUGH SATURDAY/...
LIFR CIGS WILL LINGER AT BOTH TERMINALS THROUGH SUNRISE. CIGS WILL
REMAIN BELOW ALTERNATE MINIMUMS AND COULD DROP BELOW AIRPORT
MINIMUMS OVER THE NEXT FEW HOURS. FOG COULD BECOME A PROBLEM
LATE...BUT THE LOW CIGS WILL BE THE PRIMARY ISSUE UNLESS THE
STRATUS DECKS REACH THE GROUND RESULTING IN DENSE FOG. LOW
CONFIDENCE IN THIS SCENARIO RIGHT NOW. CIGS WILL LIFT EVER SO
SLOWLY AFTER SUNRISE...BUT SHOULD RISE ABOVE ALTERNATE MINIMUMS
13-14Z...ALTHOUGH STAYING IN IFR. MVFR SHOULD RETURN BY 16-17Z AND
LINGER THE REST OF THE 06Z TAF PERIOD.
EXTENDED AVIATION OUTLOOK...LOW CEILINGS TO CLEAR OUT TUESDAY
NIGHT...IF NOT BEFORE. VFR CONDITIONS WILL THEN PREVAIL THROUGH AT
LEAST THURSDAY. CHANCES FOR FLIGHT RESTRICTIONS INCREASE INTO THE
WEEKEND AS THE NEXT SYSTEM IMPACTS THE REGION.
&&
.MARINE...
TONIGHT...CEILINGS AT HILTON HEAD HAVE DROPPED TO 100 FT...
SUGGESTING DENSE FOG IN OCCURRING JUST OFFSHORE. EXPANDED THE
MARINE DENSE FOG ADVISORY NORTH TO INCLUDE THE BEAUFORT COUNTY
WATERS. WEBCAMS OUT OF TYBEE ISLAND AND EARLIER REPORTS FROM THE
SAINT SIMMONS BAR PILOT BOAT PROVIDE ENOUGH DATA TO SUPPORT A
MARINE DENSE FOG ADVISORY FOR THE GEORGIA NEARSHORE WATERS THROUGH
6 AM. RAP VSBY PROGS APPEAR TO CAPTURE THE SEA FOG WELL AND WAS
USED TO CONSTRUCT WEATHER AND VSBY GRIDS THROUGH 6 AM.
TUESDAY THROUGH SATURDAY...A COLD FRONT WILL PUSH WELL OFFSHORE
TUESDAY AS HIGH PRESSURE WILL BEGIN TO BUILD IN TUESDAY NIGHT. AS
THE HIGH BUILDS IN A NOTABLE NORTHERLY SURGE WILL TAKE PLACE TUESDAY
NIGHT AND INTO WEDNESDAY MORNING. A SOLID 15-20 KT OF WIND IS
EXPECTED WITHIN 20 NM WITH SOME GUSTS TO 25 KT POSSIBLE. WINDS WILL
BE CLOSER TO 20-25 KT FOR THE OUTER GEORGIA WATERS WITH SOME 6 FT
SEAS POSSIBLE. SMALL CRAFT ADVISORIES MAY BE NEEDED...ESPECIALLY FOR
THE OUTER GEORGIA WATERS TUESDAY NIGHT. THEREAFTER...HIGH PRESSURE
WILL BE THE PRIMARY WEATHER FEATURE THOUGH THE GRADIENT WILL RELAX.
IT IS STILL A BIT TOO EARLY TO COMMIT ON STRENGTH OF THE WEDGE THIS
WEEKEND AND TIMING THE WARM FRONT THROUGH...BUT COMPLEX LOW LEVEL
MIXING ENVIRONMENTS ARE LIKELY.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
AMZ352-354.
&&
$$
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
1240 AM EST TUE DEC 30 2014
.SYNOPSIS...
A COLD FRONT WILL MOVE SOUTHEAST INTO THE ATLANTIC EARLY TONIGHT AND
PUSH FURTHER OFFSHORE OVERNIGHT. HIGH PRESSURE WILL BUILD INTO THE
AREA TUESDAY INTO FRIDAY...BEFORE MOVING INTO THE ATLANTIC BY
SATURDAY. A COASTAL TROUGH WILL DEVELOP EARLY THIS WEEKEND THEN
LIFT NORTH OF THE REGION ON SUNDAY. A COLD FRONT WILL THEN PASS
OFF THE COAST EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
WEAK COLD FRONT HAS CLEARED THE GEORGIA COAST WITH A PRONOUNCED
POST-FRONTAL SURFACE TROUGH DROPPING SOUTH. THE TROUGH HAS PASSED
THE CHARLESTON AIRPORT AND WILL CONTINUE TO MOVE SLOWLY SOUTH
THROUGH SUNRISE. LOW STRATUS AND EVENTUALLY FOG WILL AFFECT THE
REGION OVERNIGHT WITH OCCASIONAL LIGHT DRIZZLE. SKIES HAVE CLEARED
BRIEFLY ACROSS ALLENDALE COUNTY AND DENSE RADIATION FOG HAS
QUICKLY DEVELOPED. ITS UNCLEAR HOW LONG THE DENSE FOG WILL
LAST...BUT IT MAY BE ANOTHER 1-2 HOURS BEFORE LOW CLOUDS FILL IN
FROM THE NORTH. IN FACT...CLEARING AND DENSE FOG COULD OCCUR
ACROSS MUCH OF THE FAR WESTERN ZONES FOR THE NEXT FEW HOURS. WILL
WATCH TRENDS CAREFULLY. OTHERWISE...DRIZZLE AND EXTENSIVE CLOUD
COVER WILL PERSIST. IT IS UNCLEAR HOW STRONG POST-FRONTAL STRATUS
BUILD DOWN WILL BE...BUT THERE IS A POTENTIAL FOR SOME DENSE FOG.
MADE ADJUSTMENTS TO CLOUD COVER...FOG COVERAGE AND INTRODUCED
AREAS OF DRIZZLE INTO THE FORECAST FOR THE MIDNIGHT UPDATE. THE
REST OF THE FORECAST IS OKAY.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY/...
TUESDAY AND TUESDAY NIGHT...NEARLY ZONAL FLOW WILL PREVAIL ALOFT AS
A COLD FRONT SLIPS OFF SHORE. BACK TO THE WEST...CONFLUENT FLOW
ALOFT WILL HELP TO FORCE AN IMPRESSIVE 1058 MB HIGH OVER THE
NORTHERN ROCKIES THAT WILL BUILD INTO THE FORECAST AREA THROUGH THE
DAY. FOLLOWING LOW LEVEL THETA E FIELDS...THE LEADING EDGE OF THE
COOLER AIR BEHIND THE FRONT AND THE EXTENT OF THE STRONG SURFACE
HIGH WILL NOT OOZE INTO THE AREA UNTIL LATER IN THE DAY ON TUESDAY
AND POSSIBLY EVEN INTO THE EVENING. AHEAD OF THIS THETA E
GRADIENT...RESIDUAL MOISTURE IN THE LOWEST 3-4K FT OF THE
ATMOSPHERE SHOWS UP WELL IN MODEL TIME HEIGHTS AND CROSS SECTIONS.
THIS SHOULD MANIFEST ITSELF IN THE FORM OF EXTENSIVE STRATUS
ACROSS THE FORECAST AREA FOR MUCH OF THE DAY. IN FACT...WE MAY NOT
SEE ANY CLEARING IN THE TRI-COUNTY REGION UNTIL LATE IN THE
AFTERNOON. THIS WILL HELP KEEP TEMPERATURES AT BAY DESPITE THE
LATER ARRIVAL OF THE COOLER AIR. LOOK FOR HIGHS IN THE MID/UPPER
50S FURTHER NORTH...AND LOW 60S FURTHER TO THE SOUTH. SOME OF THE
MODELS ARE WRINGING OUT SOME MEASURABLE PRECIPITATION IN THE
MORNING DESPITE THE LACK OF FORCING AND RELATIVELY SHALLOW MOIST
LAYER. HAVE KEPT THE FORECAST DRY. OVERNIGHT...COOL NORTHERLY FLOW
WILL SETTLE IN AS THE LOW LEVELS START TO DRY OUT. THE FORECAST IS
DRY AND FEATURES LOWS FALLING INTO THE UPPER 30S NORTH...LOW 40S
FURTHER SOUTH FOR COASTAL SOUTHEAST GEORGIA.
WEDNESDAY THROUGH THURSDAY...ZONAL FLOW WILL PREVAIL ALOFT AS
EXPANSIVE BUT WEAKENING HIGH PRESSURE BUILDS IN FROM THE WEST. WE
MAY BE DEALING WITH A DECENT AMOUNT OF JET-INDUCED HIGH CLOUDS ON
WEDNESDAY...BUT A COLUMN THAT IS OVERALL VERY DRY WILL KEEP THE
FORECAST RAIN FREE THROUGH THURSDAY. TEMPERATURES WILL BE ON THE
COOL SIDE WEDNESDAY...RUNNING ABOUT 4 DEGREES BELOW NORMAL...THEN
RIGHT AROUND NORMAL ON THURSDAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
THE EXPANSIVE SURFACE HIGH WILL STEADILY SHIFT OVER GEORGIA AND
THE CAROLINAS BY FRIDAY...BEFORE MOVING INTO THE ATLANTIC WATERS
SATURDAY. A STRONG CUT OFF LOW OVER THE DESERT SOUTHWEST FRIDAY WILL
EJECT INTO THE SOUTHERN PLAINS OVER THE WEEKEND AND THEN DAMPEN
AS IT MOVE INTO THE UPPER GULF COAST REGION BY LATE WEEKEND. CLOUDS
WILL BE ON THE INCREASE THURSDAY NIGHT AS A SHORT WAVES TRAVERSES
INTO THE REGION ATOP A LARGE SUBTROPICAL RIDGE OVER FLORIDA AND
THE CARIBBEAN. THIS DISTURBANCE MAY PRODUCE SOME SPOTTY LIGHT RAINS
ON FRIDAY BUT CERTAINLY NOT SIGNIFICANT AS PRECIP IS LIKELY TO
EVAPORATE IN DRY LAYERS BELOW 10 KFT. A SLIGHT CHANCE POP LOOKS QUITE
SUFFICIENT. STEADIER RAINS ACROSS NORTH GEORGIA AND THE WESTERN
CAROLINAS MAY BEGIN TO ANCHOR A WEDGE ON SATURDAY WITH GLOBAL
MODELS DIFFERING ON SURFACE PATTERNS. THE WEEKEND LOOKS A BIT
UNSETTLED WITH PLENTY OF CLOUDS MOST AREAS AND MAINLY LOW END CHANCE
POPS AS THE UPPER WAVE FLATTENS SIGNIFICANTLY LATE IN THE WEEKEND.
SUNDAY APPEARS TO BE THE WARMER OF THE DAYS AFTER WE TRENDED DOWN A
GOOD BIT ON TEMPS NORTHERN ZONES SATURDAY. A COLD FRONT SHOULD MOVE
OFF THE COAST EARLY NEXT WEEK.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
LIFR CIGS WILL LINGER AT BOTH TERMINALS THROUGH SUNRISE. CIGS WILL
REMAIN BELOW ALTERNATE MINIMUMS AND COULD DROP BELOW AIRPORT
MINIMUMS OVER THE NEXT FEW HOURS. FOG COULD BECOME A PROBLEM
LATE...BUT THE LOW CIGS WILL BE THE PRIMARY ISSUE UNLESS THE
STRATUS DECKS REACH THE GROUND RESULTING IN DENSE FOG. LOW
CONFIDENCE IN THIS SCENARIO RIGHT NOW. CIGS WILL LIFT EVER SO
SLOWLY AFTER SUNRISE...BUT SHOULD RISE ABOVE ALTERNATE MINIMUMS
13-14Z...ALTHOUGH STAYING IN IFR. MVFR SHOULD RETURN BY 16-17Z AND
LINGER THE REST OF THE 06Z TAF PERIOD.
EXTENDED AVIATION OUTLOOK...LOW CEILINGS TO CLEAR OUT TUESDAY
NIGHT...IF NOT BEFORE. VFR CONDITIONS WILL THEN PREVAIL THROUGH AT
LEAST THURSDAY. CHANCES FOR FLIGHT RESTRICTIONS INCREASE INTO THE
WEEKEND AS THE NEXT SYSTEM IMPACTS THE REGION.
&&
.MARINE...
TONIGHT...WEBCAMS OUT OF TYBEE ISLAND AND EARLIER REPORTS FROM THE
SAINT SIMMONS BAR PILOT BOAT PROVIDE ENOUGH DATA TO SUPPORT A
MARINE DENSE FOG ADVISORY FOR THE GEORGIA NEARSHORE WATERS THROUGH
6 AM. RAP VSBY PROGS APPEAR TO CAPTURE THE SEA FOG WELL AND WAS
USED TO CONSTRUCT WEATHER AND VSBY GRIDS THROUGH 6 AM.
TUESDAY THROUGH SATURDAY...A COLD FRONT WILL PUSH WELL OFFSHORE
TUESDAY AS HIGH PRESSURE WILL BEGIN TO BUILD IN TUESDAY NIGHT. AS
THE HIGH BUILDS IN A NOTABLE NORTHERLY SURGE WILL TAKE PLACE TUESDAY
NIGHT AND INTO WEDNESDAY MORNING. A SOLID 15-20 KT OF WIND IS
EXPECTED WITHIN 20 NM WITH SOME GUSTS TO 25 KT POSSIBLE. WINDS WILL
BE CLOSER TO 20-25 KT FOR THE OUTER GEORGIA WATERS WITH SOME 6 FT
SEAS POSSIBLE. SMALL CRAFT ADVISORIES MAY BE NEEDED...ESPECIALLY FOR
THE OUTER GEORGIA WATERS TUESDAY NIGHT. THEREAFTER...HIGH PRESSURE
WILL BE THE PRIMARY WEATHER FEATURE THOUGH THE GRADIENT WILL RELAX.
IT IS STILL A BIT TOO EARLY TO COMMIT ON STRENGTH OF THE WEDGE THIS
WEEKEND AND TIMING THE WARM FRONT THROUGH...BUT COMPLEX LOW LEVEL
MIXING ENVIRONMENTS ARE LIKELY.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
AMZ354.
&&
$$
ST
AREA FORECAST DISCUSSION
NWS POCATELLO ID
155 PM MST TUE DEC 30 2014
.SHORT TERM...TONIGHT THROUGH FRIDAY. AN AMPLIFIED RIDGE OF HIGH
PRESSURE WILL PREVAIL ALONG THE PAC COAST THROUGH THURSDAY
MAINTAINING THE COLD ARCTIC NNE FLOW ACROSS THE REGION. THUS WIND
CHILL WARNINGS WILL CONTINUE ACROSS THE UPPER SNAKE RIVER
PLAIN/HIGHLANDS AND ADJOINING TRIBUTARIES WHERE ELEVATED WIND SPEEDS
WILL CREATE DANGEROUSLY COLD WIND CHILL VALUES. VALLEY FOG AND LOW
CLOUDS OVER BOISE/MOUNTAIN HOME MAY CONTINUE TO BACK UP THE VALLEY
INTO THE LOWER SNAKE RIVER PLAIN/ERN MAGIC VALLEY OVERNIGHT WHICH
MAY ALSO HELP TO MODERATE THE FRIGIDLY COLD TEMPS IN THAT AREA. BY
FRIDAY...THE RIDGE WEAKENS AS A PAC STORM BREAKS INTO WRN CANADA
ENCOURAGING DAYTIME HIGH TEMPERATURES TO WARM TO NEAR NORMAL LEVELS.
HUSTON
.LONG TERM...FRIDAY NIGHT THROUGH NEXT TUESDAY NIGHT. TWO SHORTWAVES
EXPECTED TO MOVE THROUGH CENTRAL AND EASTERN IDAHO...ONE ON THE VERY
FIRST PERIOD (FRI NIGHT)...AND A SECOND FROM LATE SUN THROUGH MON.
THEY BOTH AFFECT MAINLY THE NORTHERN HALF OF THE FORECAST
AREA...WITH NEARLY ZERO PRECIPITATION EXPECTED IN THE SOUTH CENTRAL
HIGHLANDS AND PARTS OF THE EASTERN MAGIC VALLEY. TERRAIN EFFECTS ARE
STRONG...WITH A LIGHT SNOW EVENT EXPECTED IN THE SNAKE RIVER
PLAIN...BUT MODERATE RIGHT NOW FOR THE MOUNTAINS. BY THE END OF THE
PERIOD...AN UPPER LEVEL RIDGE BEGINS TO BUILD INTO SOUTHERN IDAHO.
THIS PUSHES THE STORM TRACK FARTHER NORTH AND AWAY FROM THE GEM
STATE. THERE IS A SHORTWAVE THAT ARRIVES IN THE FINAL 24 HOURS OF
THE FORECAST THAT MAY BRUSH THE IDAHO-MONTANA BORDER REGION...BUT
ITS EFFECTS SHOULD BE SLIGHT. THE UPPER LEVEL LONG WAVE PATTERN IS
ALSO SHIFTING IN THIS WAY...REINFORCING THE LIKELIHOOD OF THE RIDGE
BUILDING INTO IDAHO FOR A DRIER END TO THIS PERIOD. MESSICK
&&
.AVIATION...ARCTIC AIR HAS MOVED IN AND STABILIZED...SO NOT LOOKING
FOR THE GUSTY WIND AGAIN TONIGHT...ALTHOUGH AMBIENT TEMPERATURES
WILL ACTUALLY BE COLDER. THE MAIN FORECAST PROBLEM THOUGH IS WHETHER
OR NOT THE STRATUS EXPECTED BY MOS GUIDANCE WILL APPEAR OR NOT.
TIME-HEIGHT CROSS SECTIONS DO NOT HAVE ANY BOUNDARY LAYER HUMIDITY
THAT EXCEEDS 90 PERCENT EXCEPT FOR KBYI. THIS MORNING THERE WAS A
LARGE STRATUS AREA IN THE TREASURE VALLEY AND WESTERN MAGIC
VALLEY...SO IT IS A CONCERN THAT THE STRATUS COULD SPREAD FROM THERE
INTO THE EASTERN MAGIC VALLEY AND KBYI. THE HRRR AND NAM NOW
INDICATE THAT THE EASTERLY WIND WILL WEAKEN AT KBYI AND GO LIGHT AND
VARIABLE AFTER 31/07Z OR SO...SO THIS WOULD LIKELY BE THE TIME OF
ARRIVAL OF ANY STRATUS. HAVE UPDATED TO PUT THIS INTO THE KBYI TAF.
THE OTHER TWO LOW ELEVATION AIRPORTS COULD STILL EXPERIENCE SOME
STRATUS...BUT BOUNDARY LAYER HUMIDITY IS NOT AS GOOD...SO HAVE PUT
IN A FEW CLOUDS BELOW 1000 FT. KSUN WAS EXPECTED TO BE IN THE
CLEAR...BUT AN AREA OF STRATUS HAS MOVED THROUGH THE SAWTOOTHS AND
IS LYING JUST TO THE SOUTH OF THE KSUN AIRDROME. ANY RETURN TO A
SOUTHERLY COMPONENT TO THE WIND AT KSUN COULD ADVECT THE STRATUS
INTO THE AIRPORT AREA. ONCE WIND THERE SWITCHES BACK TO NORTHWEST
DURING THE EARLY EVENING...THIS SHOULD END THE THREAT TO THE CIG AT
KSUN. MESSICK
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
WIND CHILL WARNING CONTINUES UNTIL NOON WEDNESDAY IDZ019.
WIND CHILL WARNING FROM 8 PM MST THIS EVENING UNTIL NOON WEDNESDAY
IDZ020-021-032.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
229 AM CST TUE DEC 30 2014
.SHORT TERM...
229 AM CST
THROUGH WEDNESDAY...
ONE WORD SUMS UP THE ENTIRE SHORT TERM FORECAST: COLD. SOMEWHAT
MODIFIED ARCTIC AIR IS SEEPING SOUTH AND SHOULD SET THE STAGE FOR
SEASONABLY COLD CONDITIONS THE NEXT COUPLE DAYS. THE LACK OF SNOW
COVER HERE OR IMMEDIATELY UPSTREAM SHOULD ALLOW THE AIR MASS TO
MODIFY SOME AND WE CERTAINLY WILL NOT BE ANYWHERE NEAR AS COLD AS
IT WOULD BE WITH SNOW COVER.
STRONG LOW PRESSURE WILL DROP SOUTH INTO HUDSON BAY WEDNESDAY AND WE
COMBINED WITH THE STRONG HIGH TO OUR SOUTH WILL SET THE STAGE FOR AN
INCREASINGLY WINDY DAY WEDNESDAY...SO EVEN THOUGH TEMPERATURES WILL
BE IN THE SAME BALLPARK AS TODAY ON WEDNESDAY THE STRONG WINDS WILL
MAKE IT FEEL COLDER WITH WIND CHILLS HOVERING NEAR ZERO OR EVEN A
BIT BELOW ALL DAY AND INTO NEW YEARS EVE NIGHT.
IZZI
&&
.LONG TERM...
229 AM CST
WEDNESDAY NIGHT THROUGH MONDAY...
TROUGH OVER THE REGION WILL RETREAT WITH RISING HEIGHTS AND
MODERATING TEMPERATURES THURSDAY AND FRIDAY WITH GENERALLY DRY
CONDITIONS. IN THE LONGER TERM ALL EYES WILL BE ON WHAT BECOMES OF
THE POWERFUL CUT OFF SYSTEM OVER THE SOUTHWEST. MEDIUM RANGE MODELS
CONTINUE TO WAFFLE AROUND WITH TIMING...TRACK...AND INTENSITY
VARYING FROM RUN TO RUN AND MODEL TO MODEL. THESE TYPE OF SYSTEMS
ARE NOT WELL HANDLED BY NUMERICAL GUIDANCE AND WOULD EXPECT CONTINUE
MODEL VARIANCES...SOME POSSIBLY SIGNIFICANT...IN THE COMING DAYS SO
AM NOT WILLING TO STRAY FROM THE BLENDED MODEL GUIDANCE WITH LOW
POPS AND RAIN OR SNOW FOR P-TYPE. DOES LOOK LIKE MORE COLD AIR WILL
PROBABLY SPILL INTO THE AREA BEHIND THAT SOUTHWESTERN SYSTEM WHEN
EVER IT DOES END UP PASSING BY.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* NORTH-NORTHWEST WINDS 10 KT OR HIGHER GRADUALLY SHIFTING WEST
LATER TODAY.
//DISCUSSION...UPDATED 06Z...
ISOLATED MVFR CIGS ARE LARGELY PASSING SOUTH OF A KVYS-KMGC
LINE...WITH A VFR DECK SLIDING SE THROUGH THE AREA THIS EVENING.
THE VFR DECK WILL CONTINUE MOVING SE AND SHOULD CLEAR THE AREA BY
DAYBREAK...WITH ANY ADDITIONAL LAKE INDUCED MVFR TO BE EAST OF
KGYY. ONLY CLOUDS LEFT WILL BE PASSING HIGH CLOUDS FROM A LOW IN
COLORADO. OTHERWISE...HIGH PRESSURE NOSES SOUTH INTO THE PLAINS TODAY
WHICH WILL ALONG NORTH- NORTHWEST WINDS TO TAKE ON A MORE WESTERLY
COMPONENT THROUGH THE DAY...LARGELY STAYING FROM 9-12 KT THROUGH
THE PERIOD.
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM-HIGH IN WINDS.
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
WEDNESDAY...VFR. STIFF SOUTHWEST WINDS.
THURSDAY-FRIDAY...VFR. WEST-SOUTHWEST WINDS.
SATURDAY-SUNDAY...CHANCE OF SNOW AND IFR.
MTF
&&
.MARINE...
304 PM CST
NORTH TO NORTHWEST WINDS PERSIST ACROSS THE LAKE TONIGHT...THEN
GRADUALLY BACK SOUTHWEST BY WEDNESDAY AND INCREASE TO GALES BY
WEDNESDAY AFTERNOON OR EVENING. IT IS NOT CERTAIN HOW EFFECTIVELY
THESE SOMEWHAT MILDER SOUTHWEST WINDS WILL SUPPORT STRONG GALES
OVER THE COLD WATER...BUT GALES DO APPEAR LIKELY. UNTIL WINDS TURN
AWAY FROM NORTH AND NORTHWEST...CONDITIONS WILL BE FAVORABLE FOR
SMALL CRAFT HEADLINES FOR THE FIRST HALF OF THE WEEK...AND
ESPECIALLY IN THE INDIANA NEARSHORE WATERS.
LENNING
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL MIDNIGHT
WEDNESDAY.
GALE WATCH...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-LMZ567-
LMZ868...9 AM WEDNESDAY TO 3 AM THURSDAY.
GALE WATCH...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...NOON WEDNESDAY TO 3 AM
THURSDAY.
&&
$$
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1128 PM CST Mon Dec 29 2014
.UPDATE...
ISSUED AT 900 PM CST MON DEC 29 2014
The lift being generated in the post frontal airmass has been very
weak, based on radar returns and local observations. Have only
seen isolated reports of flurries so far. A clearing line just
north of the band of clouds/flurries is progressing southward,
which would spell an end to the very narrow channel of
lift/clouds/flurries. Have updated the sky grids to account for
some clearing later tonight at least across the northern counties.
Less cloud cover would mean colder lows that we currently have, a
bit more toward the colder guidance numbers. Have trimmed a few
degrees from lows NW of a line from SPI to BMI. Will keep a
mention of flurries in tonight`s forecast following the trek of the
band of clouds to the SE. No other significant changes needed this
evening. Tomorrow looks like a colder but mostly sunny day. Updated
info will be available shortly.
&&
.SHORT TERM...(Tonight)
ISSUED AT 315 PM CST MON DEC 29 2014
The 18Z surface analysis indicated the leading edge of the Arctic
airmass, ahead of an intense high pressure center in the Canadian
Rockies, was sinking just south of I-80. Clouds associated with cold
air undercutting were along the I-74 corridor at 20z/2 pm CST. This
area of cloudiness, along with low clouds in southern Iowa/northern
Missouri will overspread central and eventually southeast Illinois
this evening.
There should be enough weak forcing for snow flurries, particularly
in central Illinois this evening, and the rest of the forecast area
late tonight as the short range models point to weak lift just
behind the strongest low level cold advection. The HRRR model is
trying to produce some measurable snow from Bloomington to near
Taylorville between 6 pm and Midnight. At this point, it is the only
model, doing this and has most likely latched on to the area of
light snow around Pontiac. Will keep an eye on this, but for now
will stick to the mention of flurries.
The numerical guidance appears to be on the colder side due to less
cloud cover and stronger cold advection. Thus, will be going with
lows roughly 5 degrees warmer than guidance in central IL and 2-3
degrees warmer in southeast IL due to forecast cloud cover.
&&
.LONG TERM...(Tuesday through Monday)
ISSUED AT 315 PM CST MON DEC 29 2014
The narrow band of flurries will continue into Tuesday morning, but
should dissipate by afternoon. Behind this area, and strong 1050mb
high pressure area will drop into the region. This high will bring
dry weather to the area through Thur night, as well as well below
normal temps through the period. With the center of the high
dropping into the plains Tue night, the coldest temps are expected
to be Tue night through Wed. Northwesterly winds Tue night will
still be around 10mph, so there could be enough mixing to prevent
the bottom from dropping out on the temps. However, single digits
are still expected over half of the CWA, and combined with the wind
speeds, below zero wind chills are probably Tue night/Wed morning.
Beyond this, the high pressure will slide further south into the
southern plains by Thursday night. Temps may warm slightly, but only
to back around normal.
The return of slightly warmer temps and moisture will not occur
until the high pressure area move into the southeastern US Thur
night and Fri. However, along with this will come the chance of pcpn
to the area for the end of the week and the weekend. The questions
still remain as to the timing of the pcpn return, how warm it will
get, and what p-type will occur. Both the GFS and ECMWF continue to
not agree on the overall solution with this system. However, there
is some agreement as to how the upper level will evolve into
Saturday. The upper level low pressure area will weaken and get
lifted out into the flow over the weekend. ECMWF is much quicker
with this than the GFS. Models also agree that the pcpn will not
really begin until Fri night/Sat morning. However, there still
remains a chance of pcpn Friday in the southeast, so will keep
chance pops there, though would not be surprised to see this change
later. Beyond this, models do not agree with location of pcpn and
sfc low pressure area. With the ECMWF being quicker with the upper
level system, it keeps the low further south and therefore has very
little pcpn in our area...and only in the extreme southeast. The GFS
is further north with the low, but has shifted it east since
yesterday`s model runs. However, it keeps pcpn over the area through
the weekend, just not as much as before; and with the low east,
temps may not get as warm, thereby effecting the p-type through the
weekend. Will still be keeping the p-type simple and just going with
snow, becoming rain or snow, then snow at night and rain and/or snow
again during the daytime. The chance of pcpn will continue into Sat
night. Sunday and Monday will be dry for now as the system should be
well east of the area.
Temps in the extended will warm, with the warmest temps being on
Saturday and then cooling back off by Monday as another shot of
colder air slides into the area.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
ISSUED AT 1128 PM CST MON DEC 29 2014
The weak cold front has pretty much dissipated this evening, with
just a lingering band of clouds and possibly a few flurries
drifting southward across the area. In general, a 2-4
hour period of MVFR clouds could occur over the terminal sites the
rest of the night. The base cloud layer appears to be very ragged,
and periods of MVFR could be broken up by VFR conditions. Have
included flurries only at BMI, with dry conditions elsewhere. No
impacts are expected from any snowfall overnight.
Mid clouds are indicated in the forecast soundings for the day on
Tuesday, with gradual lowering of the mid-deck Tuesday evening
down to 10K feet. Breaks in the mid-clouds appears likely based on
the amount of dry air above and below the cloud layer.
Winds will start out NNE, then shift to the N by sunrise and NW
Tuesday afternoon. Wind speeds will generally hover btwn 6-9kt at
night and 9-12kt during the day.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Shimon
SHORT TERM...Miller
LONG TERM...Auten
AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1243 PM EST TUE DEC 30 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 304 AM EST TUE DEC 30 2014
IN THE NEAR TERM PERIOD...THE FOCUS WILL BE ON THE COOL DOWN AS
ARCTIC HIGH PRESSURE STRENGTHENS OVER WESTERN CANADA. MUCH COLDER
AIR WILL SPILL INTO PORTIONS OF THE CONTINENTAL U.S. AS A RESULT.
HOWEVER...NO PRECIPITATION IS EXPECTED UNTIL THE EXTENDED PERIOD
WHEN A CUT OFF LOW OVER THE DESERT SOUTHWEST MAKES ITS PROGRESSION
ACROSS THE PLAINS...AND INTO CENTRAL INDIANA. TIMING AND TRACKING
INCONSISTENCIES ARE MAKING IT DIFFICULT TO PINPOINT PRECIP TYPE AT
THIS TIME...BUT EARLY INDICATIONS ARE SHOWING MIXED PRECIPITATION
FOR MOST OF FRIDAY AND SATURDAY. PRECIP WILL END FROM WEST TO EAST
ON SUNDAY...AND THE REMAINDER OF THE EXTENDED FORECAST WILL BE DRY
AS FLOW ALOFT BECOMES MORE ZONAL ON MONDAY.
&&
.NEAR TERM /THIS AFTERNOON/...
ISSUED AT 950 AM EST TUE DEC 30 2014
FLURRIES WILL BE REMOVED FROM THE NORTHWEST. EVEN IN CLEAR AIR
MODE THE RADARS UPSTREAM DONT SHOW ANYTHING AND THE HRRR DOESNT
INTRODUCE ANYTHING.
OTHER ELEMENTS OF THE EARLIER FORECAST ARE WORKING WELL BASED ON THE
LATEST OBSERVATIONS.&&
.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
ISSUED AT 304 AM EST TUE DEC 30 2014
THE MAIN FOCUS OF THE SHORT TERM PERIOD CONTINUES TO BE ON
TEMPERATURES AND ANY CHANGES IN TIMING OF DAY 5 STORM SYSTEM
THAT COULD POSSIBLY RESULT IN PRECIP AS EARLY AS THURSDAY NIGHT.
TEMPERATURES WILL REALLY PLUMMET TONIGHT WITH COLD AIR IN PLACE
AND PARTLY CLOUDY SKIES. SOME OF THE COLDEST TEMPS IN A LONG TIME
WILL AFFECT CENTRAL INDIANA. READINGS IN THE SINGLE DIGITS OVER
THE NORTHWESTERN THIRD OF THE FORECAST AREA CAN BE EXPECTED...AND
TEENS OVER THE REMAINDER OF CENTRAL INDIANA. THERE WILL BE LITTLE
IMPROVEMENT IN TEMPS TOMORROW DESPITE SOME SUNSHINE. HIGHS ARE
ONLY EXPECTED TO WARM INTO THE 20S. AS SURFACE FLOW BECOMES
SOUTHWESTERLY ON WEDNESDAY NIGHT...TEMPS WILL BECOME SLIGHTLY MORE
MILD THOUGH FOR THE SECOND HALF OF THE SHORT TERM PERIOD WITH
HIGHS IN THE 30S ON THURSDAY...AND LOWS IN THE 20S ON THURSDAY
NIGHT.
ATTENTION THEN TURNS TO ANY PRECIP CHANCES AT THE VERY END OF THE
SHORT TERM PERIOD AS MOISTURE AHEAD OF DESERT SOUTHWEST CUT OFF
LOW MOVES CLOSER TO THE REGION. AS OF NOW...ALL MODELS ARE STILL
TRENDING TOWARD A DRY THURSDAY/THURSDAY NIGHT...AND ARE EVEN
SLOWING DOWN FURTHER WITH THE BULK OF THE PRECIP PROGGED FOR
FRIDAY AND SATURDAY ACROSS CENTRAL INDIANA.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
ISSUED AT 304 AM EST TUE DEC 30 2014
THE MAIN FOCUS OF THE SHORT TERM PERIOD CONTINUES TO BE ON
TEMPERATURES AND ANY CHANGES IN TIMING OF DAY 5 STORM SYSTEM
THAT COULD POSSIBLY RESULT IN PRECIP AS EARLY AS THURSDAY NIGHT.
TEMPERATURES WILL REALLY PLUMMET TONIGHT WITH COLD AIR IN PLACE
AND PARTLY CLOUDY SKIES. SOME OF THE COLDEST TEMPS IN A LONG TIME
WILL AFFECT CENTRAL INDIANA. READINGS IN THE SINGLE DIGITS OVER
THE NORTHWESTERN THIRD OF THE FORECAST AREA CAN BE EXPECTED...AND
TEENS OVER THE REMAINDER OF CENTRAL INDIANA. THERE WILL BE LITTLE
IMPROVEMENT IN TEMPS TOMORROW DESPITE SOME SUNSHINE. HIGHS ARE
ONLY EXPECTED TO WARM INTO THE 20S. AS SURFACE FLOW BECOMES
SOUTHWESTERLY ON WEDNESDAY NIGHT...TEMPS WILL BECOME SLIGHTLY MORE
MILD THOUGH FOR THE SECOND HALF OF THE SHORT TERM PERIOD WITH
HIGHS IN THE 30S ON THURSDAY...AND LOWS IN THE 20S ON THURSDAY
NIGHT.
ATTENTION THEN TURNS TO ANY PRECIP CHANCES AT THE VERY END OF THE
SHORT TERM PERIOD AS MOISTURE AHEAD OF DESERT SOUTHWEST CUT OFF
LOW MOVES CLOSER TO THE REGION. AS OF NOW...ALL MODELS ARE STILL
TRENDING TOWARD A DRY THURSDAY/THURSDAY NIGHT...AND ARE EVEN
SLOWING DOWN FURTHER WITH THE BULK OF THE PRECIP PROGGED FOR
FRIDAY AND SATURDAY ACROSS CENTRAL INDIANA.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
ISSUED AT 410 AM EST MON DEC 30 2014
THERE IS BETTER AGREEMENT BETWEEN THE MODELS AS THEY ALL BRING
PRECIPITATION NORTH ACROSS OUR ENTIRE REGION FRIDAY NIGHT THROUGH
SATURDAY. PREVIOUSLY THE EURO ONLY BROUGHT IT INTO OUR SOUTHERN
AREAS...WHILE MOST OTHER MODELS BROUGHT IT FARTHER NORTH. WITH THE
EXCEPTION OF THE NAM ALL MODELS HAVE TRENDED A LITTLE SLOWER IN NOT
BEGINNING PRECIPITATION UNTIL FRIDAY NIGHT. WILL GO ALONG WITH THIS
SCENARIO AND KEEP ALL BUT THE FAR SOUTH DRY UNTIL FRIDAY NIGHT.
PRECIPITATION WILL BE THE MAIN ISSUE FRIDAY NIGHT AND SATURDAY AS
MODELS PULL WARMER NORTH INTO OUR REGION. BUFKIT SOUNDINGS
INDICATE LOW CHANCES OF SNOW ACROSS OUR NORTH AND FREEZING
PRECIPITATION SOUTH EARLY FRIDAY NIGHT AND WITH THICKNESS AND
TEMPERATURES RISING SLOWLY OVERNIGHT WHICH SHOULD ALLOW CHANCES OF
FREEZING RAIN TO SPREAD NORTH BY SATURDAY MORNING AND THEN
PRECIPITATION BEING MOSTLY RAIN SATURDAY AFTERNOON. ALL MODELS
INDICATE QUITE A BIT OF PRECIPITATION AROUND SATURDAY AND WENT WITH
HPC PROGS WHICH INDICATED LIKELY POPS CENTRAL AND SOUTH SATURDAY.
AFTER LOW PRESSURE GOES BY...MODELS INDICATE A CHANGEOVER BACK TO
LIGHT SNOW OR FLURRIES SATURDAY NIGHT WITH RETURN OF COLDER AIR.
WILL ALSO MENTION SLIGHT CHANCE OF SNOW SHOWERS WITH MIXED PRECIP
FAR SOUTHEAST SUNDAY MORNING AND THEN DRY AFTER THAT AS COLD HIGH
PRESSURE BUILDS BACK IN.
MADE SOME ADJUSTMENTS TO HOURLY TEMPERATURES FRIDAY NIGHT AND
SATURDAY MORNING AS TEMPERATURES WILL BE NON-DIURNAL.
OTHERWISE...MADE ONLY MINOR TWEAKS TO A MOS BLEND ON TEMPERATURES
MOST OTHER PERIODS.
&&
.AVIATION /DISCUSSION FOR THE 301800Z TAF ISSUANCE/...
ISSUED AT 1233 PM EST TUE DEC 30 2014
MAINLY VFR CONDITIONS EXPECTED THROUGH MOST OF THE TAF PERIOD. THE
ONE CAVEAT TO THAT IS THE BAND OF SCT/BKN MVFR CEILINGS EXISTING
WITHIN THE 2 OR 3 COUNTY WIDE BAND OF CLOUDS CURRENTLY EXTENDING
DOWN FROM NORTH CENTRAL INDIANA THROUGH WEST CENTRAL INDIANA.
UNDERNEATH SOME OF THE MORE CONCENTRATED CLOUD SHIELD...BKN TO
OVC MVFR CEILINGS ARE PERSISTING. EXPECT THOSE MVFR CEILINGS TO
MOVE OUT OF LAF BY 30/20Z AND OUT OF HUF AROUND 30/21Z. DO CURRENTLY
EXPECT TO SEE THOSE MVFR CEILINGS MAKE IT INTO IND AROUND 30/18Z
AND INTO BMG BY 30/19Z AS CU FIELD IS THICKENING ACROSS WEST-
CENTRAL AND CENTRAL PORTIONS OF CENTRAL INDIANA. EXPECT THE MVFR
CEILINGS TO SCATTER OR MOVE FROM IND/BMG BY 30/22-23Z. ALONG WITH
THE INCREASE IN CLOUDS...A GRADUAL BACKING OF WINDS TO THE
NORTHWEST IS EXPECTED AS WELL. WOULD NOT BE SURPRISED TO SEE AN OB
OR TWO FROM LAF WITH -SN SENSING FLURRIES WITHIN THE NEXT FEW
HOURS AS WELL.
OTHERWISE...EXPECT VFR CONDITIONS WITH FEW/SCT CU AND A SCATTERED
MID-LEVEL DECK. MODEL SOUNDINGS CONTINUE TO INDICATE CLEARING
OCCURRING TONIGHT AS ARCTIC HIGH PRESSURE BUILDS INTO THE GREAT
PLAINS STATES.
NORTH WINDS AROUND 10 KNOTS WILL BECOME NORTHWEST THIS AFTERNOON
AND WEST AROUND 5 TO 7 KNOTS LATE TONIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...TDUD
NEAR TERM...JK
SHORT TERM...TDUD
LONG TERM...JH
AVIATION...MRD
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1212 PM EST TUE DEC 30 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 304 AM EST TUE DEC 30 2014
IN THE NEAR TERM PERIOD...THE FOCUS WILL BE ON THE COOL DOWN AS
ARCTIC HIGH PRESSURE STRENGTHENS OVER WESTERN CANADA. MUCH COLDER
AIR WILL SPILL INTO PORTIONS OF THE CONTINENTAL U.S. AS A RESULT.
HOWEVER...NO PRECIPITATION IS EXPECTED UNTIL THE EXTENDED PERIOD
WHEN A CUT OFF LOW OVER THE DESERT SOUTHWEST MAKES ITS PROGRESSION
ACROSS THE PLAINS...AND INTO CENTRAL INDIANA. TIMING AND TRACKING
INCONSISTENCIES ARE MAKING IT DIFFICULT TO PINPOINT PRECIP TYPE AT
THIS TIME...BUT EARLY INDICATIONS ARE SHOWING MIXED PRECIPITATION
FOR MOST OF FRIDAY AND SATURDAY. PRECIP WILL END FROM WEST TO EAST
ON SUNDAY...AND THE REMAINDER OF THE EXTENDED FORECAST WILL BE DRY
AS FLOW ALOFT BECOMES MORE ZONAL ON MONDAY.
&&
.NEAR TERM /THIS AFTERNOON/...
ISSUED AT 950 AM EST TUE DEC 30 2014
FLURRIES WILL BE REMOVED FROM THE NORTHWEST. EVEN IN CLEAR AIR
MODE THE RADARS UPSTREAM DONT SHOW ANYTHING AND THE HRRR DOESNT
INTRODUCE ANYTHING.
OTHER ELEMENTS OF THE EARLIER FORECAST ARE WORKING WELL BASED ON THE
LATEST OBSERVATIONS.&&
.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
ISSUED AT 304 AM EST TUE DEC 30 2014
THE MAIN FOCUS OF THE SHORT TERM PERIOD CONTINUES TO BE ON
TEMPERATURES AND ANY CHANGES IN TIMING OF DAY 5 STORM SYSTEM
THAT COULD POSSIBLY RESULT IN PRECIP AS EARLY AS THURSDAY NIGHT.
TEMPERATURES WILL REALLY PLUMMET TONIGHT WITH COLD AIR IN PLACE
AND PARTLY CLOUDY SKIES. SOME OF THE COLDEST TEMPS IN A LONG TIME
WILL AFFECT CENTRAL INDIANA. READINGS IN THE SINGLE DIGITS OVER
THE NORTHWESTERN THIRD OF THE FORECAST AREA CAN BE EXPECTED...AND
TEENS OVER THE REMAINDER OF CENTRAL INDIANA. THERE WILL BE LITTLE
IMPROVEMENT IN TEMPS TOMORROW DESPITE SOME SUNSHINE. HIGHS ARE
ONLY EXPECTED TO WARM INTO THE 20S. AS SURFACE FLOW BECOMES
SOUTHWESTERLY ON WEDNESDAY NIGHT...TEMPS WILL BECOME SLIGHTLY MORE
MILD THOUGH FOR THE SECOND HALF OF THE SHORT TERM PERIOD WITH
HIGHS IN THE 30S ON THURSDAY...AND LOWS IN THE 20S ON THURSDAY
NIGHT.
ATTENTION THEN TURNS TO ANY PRECIP CHANCES AT THE VERY END OF THE
SHORT TERM PERIOD AS MOISTURE AHEAD OF DESERT SOUTHWEST CUT OFF
LOW MOVES CLOSER TO THE REGION. AS OF NOW...ALL MODELS ARE STILL
TRENDING TOWARD A DRY THURSDAY/THURSDAY NIGHT...AND ARE EVEN
SLOWING DOWN FURTHER WITH THE BULK OF THE PRECIP PROGGED FOR
FRIDAY AND SATURDAY ACROSS CENTRAL INDIANA.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
ISSUED AT 304 AM EST TUE DEC 30 2014
THE MAIN FOCUS OF THE SHORT TERM PERIOD CONTINUES TO BE ON
TEMPERATURES AND ANY CHANGES IN TIMING OF DAY 5 STORM SYSTEM
THAT COULD POSSIBLY RESULT IN PRECIP AS EARLY AS THURSDAY NIGHT.
TEMPERATURES WILL REALLY PLUMMET TONIGHT WITH COLD AIR IN PLACE
AND PARTLY CLOUDY SKIES. SOME OF THE COLDEST TEMPS IN A LONG TIME
WILL AFFECT CENTRAL INDIANA. READINGS IN THE SINGLE DIGITS OVER
THE NORTHWESTERN THIRD OF THE FORECAST AREA CAN BE EXPECTED...AND
TEENS OVER THE REMAINDER OF CENTRAL INDIANA. THERE WILL BE LITTLE
IMPROVEMENT IN TEMPS TOMORROW DESPITE SOME SUNSHINE. HIGHS ARE
ONLY EXPECTED TO WARM INTO THE 20S. AS SURFACE FLOW BECOMES
SOUTHWESTERLY ON WEDNESDAY NIGHT...TEMPS WILL BECOME SLIGHTLY MORE
MILD THOUGH FOR THE SECOND HALF OF THE SHORT TERM PERIOD WITH
HIGHS IN THE 30S ON THURSDAY...AND LOWS IN THE 20S ON THURSDAY
NIGHT.
ATTENTION THEN TURNS TO ANY PRECIP CHANCES AT THE VERY END OF THE
SHORT TERM PERIOD AS MOISTURE AHEAD OF DESERT SOUTHWEST CUT OFF
LOW MOVES CLOSER TO THE REGION. AS OF NOW...ALL MODELS ARE STILL
TRENDING TOWARD A DRY THURSDAY/THURSDAY NIGHT...AND ARE EVEN
SLOWING DOWN FURTHER WITH THE BULK OF THE PRECIP PROGGED FOR
FRIDAY AND SATURDAY ACROSS CENTRAL INDIANA.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
ISSUED AT 410 AM EST MON DEC 30 2014
THERE IS BETTER AGREEMENT BETWEEN THE MODELS AS THEY ALL BRING
PRECIPITATION NORTH ACROSS OUR ENTIRE REGION FRIDAY NIGHT THROUGH
SATURDAY. PREVIOUSLY THE EURO ONLY BROUGHT IT INTO OUR SOUTHERN
AREAS...WHILE MOST OTHER MODELS BROUGHT IT FARTHER NORTH. WITH THE
EXCEPTION OF THE NAM ALL MODELS HAVE TRENDED A LITTLE SLOWER IN NOT
BEGINNING PRECIPITATION UNTIL FRIDAY NIGHT. WILL GO ALONG WITH THIS
SCENARIO AND KEEP ALL BUT THE FAR SOUTH DRY UNTIL FRIDAY NIGHT.
PRECIPITATION WILL BE THE MAIN ISSUE FRIDAY NIGHT AND SATURDAY AS
MODELS PULL WARMER NORTH INTO OUR REGION. BUFKIT SOUNDINGS
INDICATE LOW CHANCES OF SNOW ACROSS OUR NORTH AND FREEZING
PRECIPITATION SOUTH EARLY FRIDAY NIGHT AND WITH THICKNESS AND
TEMPERATURES RISING SLOWLY OVERNIGHT WHICH SHOULD ALLOW CHANCES OF
FREEZING RAIN TO SPREAD NORTH BY SATURDAY MORNING AND THEN
PRECIPITATION BEING MOSTLY RAIN SATURDAY AFTERNOON. ALL MODELS
INDICATE QUITE A BIT OF PRECIPITATION AROUND SATURDAY AND WENT WITH
HPC PROGS WHICH INDICATED LIKELY POPS CENTRAL AND SOUTH SATURDAY.
AFTER LOW PRESSURE GOES BY...MODELS INDICATE A CHANGEOVER BACK TO
LIGHT SNOW OR FLURRIES SATURDAY NIGHT WITH RETURN OF COLDER AIR.
WILL ALSO MENTION SLIGHT CHANCE OF SNOW SHOWERS WITH MIXED PRECIP
FAR SOUTHEAST SUNDAY MORNING AND THEN DRY AFTER THAT AS COLD HIGH
PRESSURE BUILDS BACK IN.
MADE SOME ADJUSTMENTS TO HOURLY TEMPERATURES FRIDAY NIGHT AND
SATURDAY MORNING AS TEMPERATURES WILL BE NON-DIURNAL.
OTHERWISE...MADE ONLY MINOR TWEAKS TO A MOS BLEND ON TEMPERATURES
MOST OTHER PERIODS.
&&
.AVIATION /DISCUSSION FOR THE 301800Z TAF ISSUANCE/...
ISSUED AT 1147 AM EST TUE DEC 30 2014
MAINLY VFR CONDITIONS EXPECTED THROUGH MOST OF THE TAF PERIOD. THE
ONE CAVEAT TO THAT IS THE SPORADIC FEW/SCT MVFR CEILINGS EXISTING WITHIN
THE THIN BAND OF CLOUDS CURRENTLY EXTENDING DOWN FROM NORTH
CENTRAL INDIANA THROUGH WEST CENTRAL INDIANA. UNDERNEATH SOME OF
THE MORE CONCENTRATED CLOUD SHIELD...I.E. ABOVE AND SOUTHWEST OF
HUF AND ABOVE AND NORTH OF LAF...BKN TO OVC MVFR CEILINGS ARE
PERSISTING. EXPECT THOSE MVFR CEILINGS TO MOVE OUT OF LAF IN THE
NEXT 2 HRS OR SO AND OUT OF HUF WITHIN THE NEXT 3 TO 4 HOURS. DO
NOT CURRENTLY EXPECT TO SEE THOSE MVFR CEILINGS MAKE IT INTO IND
OR BMG. HOWEVER...IT IS NOT OUTSIDE THE REALM OF POSSIBILITY OVER
THE NEXT FEW HOURS AS CU FIELD IS THICKENING ACROSS WEST-CENTRAL AND
CENTRAL PORTIONS OF CENTRAL INDIANA. ALONG WITH THE INCREASE IN
CLOUDS...A GRADUAL BACKING OF WINDS TO THE NORTHWEST IS EXPECTED
AS WELL. WOULD NOT BE SURPRISED TO SEE AN OB OR TWO FROM LAF WITH
-SN SENSING FLURRIES WITHIN THE NEXT FEW HOURS AS WELL.
OTHERWISE...EXPECT VFR CONDITIONS WITH FEW/SCT CU AND A SCATTERED
MID-LEVEL DECK. MODEL SOUNDINGS CONTINUE TO INDICATE CLEARING
OCCURRING TONIGHT AS ARCTIC HIGH PRESSURE BUILDS INTO THE GREAT
PLAINS STATES.
NORTH WINDS AROUND 10 KNOTS WILL BECOME NORTHWEST THIS AFTERNOON
AND WEST AROUND 5 TO 7 KNOTS LATE TONIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...TDUD
NEAR TERM...JK
SHORT TERM...TDUD
LONG TERM...JH
AVIATION...MRD
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
951 AM EST TUE DEC 30 2014
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 304 AM EST TUE DEC 30 2014
IN THE NEAR TERM PERIOD...THE FOCUS WILL BE ON THE COOL DOWN AS
ARCTIC HIGH PRESSURE STRENGTHENS OVER WESTERN CANADA. MUCH COLDER
AIR WILL SPILL INTO PORTIONS OF THE CONTINENTAL U.S. AS A RESULT.
HOWEVER...NO PRECIPITATION IS EXPECTED UNTIL THE EXTENDED PERIOD
WHEN A CUT OFF LOW OVER THE DESERT SOUTHWEST MAKES ITS PROGRESSION
ACROSS THE PLAINS...AND INTO CENTRAL INDIANA. TIMING AND TRACKING
INCONSISTENCIES ARE MAKING IT DIFFICULT TO PINPOINT PRECIP TYPE AT
THIS TIME...BUT EARLY INDICATIONS ARE SHOWING MIXED PRECIPITATION
FOR MOST OF FRIDAY AND SATURDAY. PRECIP WILL END FROM WEST TO EAST
ON SUNDAY...AND THE REMAINDER OF THE EXTENDED FORECAST WILL BE DRY
AS FLOW ALOFT BECOMES MORE ZONAL ON MONDAY.
&&
.NEAR TERM /THIS AFTERNOON/...
ISSUED AT 950 AM EST TUE DEC 30 2014
FLURRIES WILL BE REMOVED FROM THE NORTHWEST. EVEN IN CLEAR AIR
MODE THE RADARS UPSTREAM DONT SHOW ANYTHING AND THE HRRR DOESNT
INTRODUCE ANYTHING.
OTHER ELEMENTS OF THE EARLIER FORECAST ARE WORKING WELL BASED ON THE
LATEST OBSERVATIONS.&&
.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
ISSUED AT 304 AM EST TUE DEC 30 2014
THE MAIN FOCUS OF THE SHORT TERM PERIOD CONTINUES TO BE ON
TEMPERATURES AND ANY CHANGES IN TIMING OF DAY 5 STORM SYSTEM
THAT COULD POSSIBLY RESULT IN PRECIP AS EARLY AS THURSDAY NIGHT.
TEMPERATURES WILL REALLY PLUMMET TONIGHT WITH COLD AIR IN PLACE
AND PARTLY CLOUDY SKIES. SOME OF THE COLDEST TEMPS IN A LONG TIME
WILL AFFECT CENTRAL INDIANA. READINGS IN THE SINGLE DIGITS OVER
THE NORTHWESTERN THIRD OF THE FORECAST AREA CAN BE EXPECTED...AND
TEENS OVER THE REMAINDER OF CENTRAL INDIANA. THERE WILL BE LITTLE
IMPROVEMENT IN TEMPS TOMORROW DESPITE SOME SUNSHINE. HIGHS ARE
ONLY EXPECTED TO WARM INTO THE 20S. AS SURFACE FLOW BECOMES
SOUTHWESTERLY ON WEDNESDAY NIGHT...TEMPS WILL BECOME SLIGHTLY MORE
MILD THOUGH FOR THE SECOND HALF OF THE SHORT TERM PERIOD WITH
HIGHS IN THE 30S ON THURSDAY...AND LOWS IN THE 20S ON THURSDAY
NIGHT.
ATTENTION THEN TURNS TO ANY PRECIP CHANCES AT THE VERY END OF THE
SHORT TERM PERIOD AS MOISTURE AHEAD OF DESERT SOUTHWEST CUT OFF
LOW MOVES CLOSER TO THE REGION. AS OF NOW...ALL MODELS ARE STILL
TRENDING TOWARD A DRY THURSDAY/THURSDAY NIGHT...AND ARE EVEN
SLOWING DOWN FURTHER WITH THE BULK OF THE PRECIP PROGGED FOR
FRIDAY AND SATURDAY ACROSS CENTRAL INDIANA.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
ISSUED AT 410 AM EST MON DEC 30 2014
THERE IS BETTER AGREEMENT BETWEEN THE MODELS AS THEY ALL BRING
PRECIPITATION NORTH ACROSS OUR ENTIRE REGION FRIDAY NIGHT THROUGH
SATURDAY. PREVIOUSLY THE EURO ONLY BROUGHT IT INTO OUR SOUTHERN
AREAS...WHILE MOST OTHER MODELS BROUGHT IT FARTHER NORTH. WITH THE
EXCEPTION OF THE NAM ALL MODELS HAVE TRENDED A LITTLE SLOWER IN NOT
BEGINNING PRECIPITATION UNTIL FRIDAY NIGHT. WILL GO ALONG WITH THIS
SCENARIO AND KEEP ALL BUT THE FAR SOUTH DRY UNTIL FRIDAY NIGHT.
PRECIPITATION WILL BE THE MAIN ISSUE FRIDAY NIGHT AND SATURDAY AS
MODELS PULL WARMER NORTH INTO OUR REGION. BUFKIT SOUNDINGS
INDICATE LOW CHANCES OF SNOW ACROSS OUR NORTH AND FREEZING
PRECIPITATION SOUTH EARLY FRIDAY NIGHT AND WITH THICKNESS AND
TEMPERATURES RISING SLOWLY OVERNIGHT WHICH SHOULD ALLOW CHANCES OF
FREEZING RAIN TO SPREAD NORTH BY SATURDAY MORNING AND THEN
PRECIPITATION BEING MOSTLY RAIN SATURDAY AFTERNOON. ALL MODELS
INDICATE QUITE A BIT OF PRECIPITATION AROUND SATURDAY AND WENT WITH
HPC PROGS WHICH INDICATED LIKELY POPS CENTRAL AND SOUTH SATURDAY.
AFTER LOW PRESSURE GOES BY...MODELS INDICATE A CHANGEOVER BACK TO
LIGHT SNOW OR FLURRIES SATURDAY NIGHT WITH RETURN OF COLDER AIR.
WILL ALSO MENTION SLIGHT CHANCE OF SNOW SHOWERS WITH MIXED PRECIP
FAR SOUTHEAST SUNDAY MORNING AND THEN DRY AFTER THAT AS COLD HIGH
PRESSURE BUILDS BACK IN.
MADE SOME ADJUSTMENTS TO HOURLY TEMPERATURES FRIDAY NIGHT AND
SATURDAY MORNING AS TEMPERATURES WILL BE NON-DIURNAL.
OTHERWISE...MADE ONLY MINOR TWEAKS TO A MOS BLEND ON TEMPERATURES
MOST OTHER PERIODS.
&&
.AVIATION /DISCUSSION FOR 301500Z KIND TAF UPDATE/...
ISSUED AT 913 AM EST TUE DEC 30 2014
NOT MUCH CHANGE TO PREVIOUS TAF FOR IND. STILL EXPECTING MAINLY
VFR THROUGH THE PERIOD. BASED ON CURRENT OBSERVATIONAL
TRENDS...DID STRENGTHEN THE WINDS SLIGHTLY OVER THE NEXT COUPLE
HOURS AND ALSO DELAYED THE BACKING OF THE SURFACE WINDS. THE
PREVIOUS DISCUSSION FOLLOWS...
ISSUED AT 625 AM AM EST TUE DEC 30 2014
SATELLITE INDICATES BAND OF STRATO CU WITH DRY SECONDARY COLD
FRONT WILL BE MOVING ACROSS TAF SITES TODAY. COULD BE A PERIOD OF
MVFR CEILINGS AT KLAF THIS MORNING...OTHERWISE CEILINGS WILL BE
JUST ABOVE 3 THOUSAND FEET AS BAND MOVES AS IT MOVES ACROSS.
TIMING WILL BE MID MORNING TO MID AFTERNOON AT KLAF AND KHUF AND
MAINLY THIS AFTERNOON AT KIND AND KBMG. OTHERWISE...VFR WITH FEW
CU AND SCATTERED MID CLOUDS. MODEL SOUNDINGS INDICATE CLEARING
SHOULD OCCUR LATE TONIGHT AS ARCTIC HIGH PRESSURE BUILDS INTO THE
GREAT PLAINS.
NORTH WINDS AROUND 10 KNOTS WILL BECOME NORTHWEST THIS AFTERNOON AND
WEST AROUND 5 KNOTS LATE TONIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...TDUD
NEAR TERM...JK
SHORT TERM...TDUD
LONG TERM...JH
AVIATION...MRD/JH
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
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AREA FORECAST DISCUSSION
NWS WICHITA KS
310 AM CST TUE DEC 30 2014
.SYNOPSIS...
ISSUED AT 308 AM CST TUE DEC 30 2014
LARGE POSITIVE TILTED UPPER TROUGH EXTENDS FROM THE NORTHERN
PLAINS INTO NORTHERN CA WITH THE MAIN VORT LOBE OVER THE WESTERN
PORTION OF THIS TROUGH. AT THE SURFACE...ARCTIC AIR IS SPILLING
SOUTH ACROSS THE PLAINS WITH NEGATIVE TEMP VALUES NOW ENCOMPASSING
THE NORTHERN HALF OF NEBRASKA.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 308 AM CST TUE DEC 30 2014
LIGHT SNOW HAS BEEN PERSISTENT OVERNIGHT FOR AREAS ALONG AND WEST
OF I-135 AND AM EXPECTING THIS TO CONTINUE THROUGH AT LEAST THE
MORNING HOURS AND POSSIBLY INTO THE AFTERNOON. FEEL CONFIDENT IN
THIS AS ISENTROPIC LIFT IN THE 280-285K LAYER REMAINS PRETTY MUCH
UNCHANGED FROM WHAT IS OCCURRING NOW. EVEN THOUGH MOST SITES WILL
NOT TIP OFF A 0.01 OF PRECIP...WILL RUN WITH HIGH POP WORDING AS
WHAT IS OCCURRING IS MORE THAN JUST FLURRIES WITH SOME
VISIBILITIES AT OR LESS THAN 3SM. WILL KEEP WITH CURRENT HEADLINE
MAINLY DUE TO COMING CLOSE TO WIND CHILL CRITERIA.
THE FRIGID AIRMASS WILL REMAIN IN PLACE TONIGHT THROUGH WED WITH
TEMPS AROUND 20 DEGREES BELOW NORMAL. WOULD NOT BE SHOCKED IF WE
GET SOME FLURRIES TO LINGER TONIGHT OVER THE SOUTHWEST PORTION OF
THE FORECAST AREA AS THE LIFT IS SLOW TO MOVE OUT. THE MAIN VORT
LOBE OUT WEST IS EXPECTED TO CUT OFF AND TRACK ACROSS THE DESERT
SOUTHWEST BY THU AND WILL BECOME THE FOCUS FOR THE EXTENDED
PERIODS.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 308 AM CST TUE DEC 30 2014
THROUGH 00Z SAT BOTH THE ECMWF AND GFS REMAIN FAIRLY SIMILAR IN
TRACKING THE CLOSED LOW OVER EASTERN NM. HOWEVER...THESE MODELS
AGAIN START TO DEVIATE FOR THE FRI NIGHT THROUGH SAT TIME FRAME.
THE GFS IS CONTINUING THE TREND OF LIFTING THE IMPULSE FURTHER
NORTH COMPARED TO THE ECMWF. THE GFS SOLUTION WOULD RESULT IN
WIDESPREAD WINTRY PRECIP FOR MOST OF THE FORECAST AREA FRI NIGHT
INTO SAT MORNING WITH THE ECMWF KEEPING MOST OF THE PRECIP SOUTH
OF THE KS/OK BORDER. HAVE A SLIGHT LEAN TO THE GFS SINCE IT HAS
BEEN A BIT MORE CONSISTENT AND FEEL THAT AT LEAST A PORTION OF OUR
FORECAST AREA WILL BE IMPACTED BY WINTRY PRECIP OVER THE WEEKEND.
LAWSON
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1135 PM CST MON DEC 29 2014
LIGHT SNOW IS MOVING ACROSS THE WESTERN SECTIONS OF THE FORECAST
AREA IMPACTING KRSL/KHUT/KICT AND WILL SOON IMPACT KSLN. MVFR TO
IFR CEILINGS AND VISIBILITIES ARE ALSO IMPACTING THE TERMINALS.
EXPECT THIS TO PERSIST THROUGH THE OVERNIGHT HOURS. THE SHORT-
TERM HIGHER RES RUC GUIDANCE SHOWS THE SNOW DIMINISHING AROUND
SUNRISE...WHILE THE NAM KEEPS PRECIP AROUND LONGER. HAVE TRENDED
TOWARD THE RUC AT THIS TIME IN THE TAFS ENDING THE SNOW AROUND
SUNRISE AND EVENTUALLY LIFTING THE CEILINGS TO HIGH END MVFR AND
IN SOME CASES VFR BY THE END OF THE PERIOD. NORTH TO NORTHEASTERLY
WINDS WILL PERSIST THROUGH THE FORECAST.
BILLINGS WRIGHT
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 18 4 22 14 / 30 10 0 0
HUTCHINSON 13 2 21 13 / 40 10 0 0
NEWTON 15 2 21 13 / 20 10 0 0
ELDORADO 18 4 22 14 / 20 10 0 0
WINFIELD-KWLD 21 6 24 16 / 20 10 0 0
RUSSELL 7 -3 15 8 / 30 10 0 0
GREAT BEND 8 -2 17 10 / 30 10 0 0
SALINA 12 -1 18 12 / 30 10 0 0
MCPHERSON 12 1 20 12 / 30 10 0 0
COFFEYVILLE 30 9 27 16 / 10 10 0 0
CHANUTE 25 5 24 15 / 10 10 0 0
IOLA 23 4 24 15 / 10 10 0 0
PARSONS-KPPF 27 7 25 16 / 10 10 0 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR KSZ032-033-047-
048.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
1135 PM CST MON DEC 29 2014
...UPDATED FOR 06Z AVIATION DISCUSSION...
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 234 PM CST MON DEC 29 2014
ARCTIC AIR OVER THE DAKOTAS/NEBRASKA WAS CONTINUING TO SURGE
SOUTH AND WILL SPREAD ACROSS KANSAS FOR TONIGHT AND REMAIN OVER
THE AREA FOR THE NEXT COUPLE OF DAYS. MEANWHILE SNOW CURRENTLY
OVER NORTHWEST KANSAS WILL EXPAND EASTWARD INTO CENTRAL KANSAS FOR
TONIGHT WITH SOME LIGHT ACCUMULATIONS POSSIBLE...WITH A TRACE TO 2
INCHES POSSIBLE. THE SNOW SHOULD BEGIN TO TAPER OFF QUICKLY FOR
TUESDAY MORNING...AS THE VERTICAL MOTION FROM UPPER LEVEL WAVE
DIMINISHES. WIND CHILLS WILL DROP TO DANGEROUS LEVELS FOR TUESDAY
MORNING AND COULD AGAIN FOR WEDNESDAY MORNING ACROSS CENTRAL
KANSAS. A WIND CHILL ADVISORY COULD BE HOISTED BY LATER SHIFTS FOR
WEDNESDAY MORNING IF TRENDS MAINTAIN. TEMPERATURES SHOULD MODIFY
AND WARM A BIT COME THURSDAY AS DOWNSLOPE FLOW HELPS BOOSTS
DAYTIME HIGHS.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 234 PM CST MON DEC 29 2014
SOME UNCERTAINTY REMAINS BETWEEN THE GFS/ECMWF MODEL AS EXPECTED
THIS FAR OUT IN TIME WITH POSITIONING OF THE FRI/SAT SYSTEM...BUT
NONE THE LESS WINTER PRECIPITATION STILL SEEMS REASONABLE FOR
MAINLY SOUTH CENTRAL/SOUTHEAST KANSAS. BELOW NORMAL TEMPERATURES
WILL CONTINUE FOR SUNDAY AND MONDAY AS SURFACE HIGH PRESSURE
BUILDS OVER KANSAS...AND TEMPERATURES COULD BE EVEN COLDER IF
FRESH SNOW FALLS ACROSS THE REGION.
JAKUB
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1135 PM CST MON DEC 29 2014
LIGHT SNOW IS MOVING ACROSS THE WESTERN SECTIONS OF THE FORECAST
AREA IMPACTING KRSL/KHUT/KICT AND WILL SOON IMPACT KSLN. MVFR TO
IFR CEILINGS AND VISIBILITIES ARE ALSO IMPACTING THE TERMINALS.
EXPECT THIS TO PERSIST THROUGH THE OVERNIGHT HOURS. THE SHORT-
TERM HIGHER RES RUC GUIDANCE SHOWS THE SNOW DIMINISHING AROUND
SUNRISE...WHILE THE NAM KEEPS PRECIP AROUND LONGER. HAVE TRENDED
TOWARD THE RUC AT THIS TIME IN THE TAFS ENDING THE SNOW AROUND
SUNRISE AND EVENTUALLY LIFTING THE CEILINGS TO HIGH END MVFR AND
IN SOME CASES VFR BY THE END OF THE PERIOD. NORTH TO NORTHEASTERLY
WINDS WILL PERSIST THROUGH THE FORECAST.
BILLINGS WRIGHT
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 15 19 4 21 / 60 10 10 0
HUTCHINSON 10 15 2 20 / 100 20 10 0
NEWTON 11 17 2 20 / 50 10 10 0
ELDORADO 14 20 4 22 / 30 10 10 0
WINFIELD-KWLD 18 22 6 23 / 30 10 10 0
RUSSELL 4 9 -3 18 / 100 30 10 0
GREAT BEND 6 10 -2 18 / 100 30 10 0
SALINA 8 12 -1 19 / 90 10 10 0
MCPHERSON 9 14 1 20 / 100 10 10 0
COFFEYVILLE 23 28 9 25 / 30 10 10 0
CHANUTE 19 24 5 23 / 10 10 10 0
IOLA 18 23 4 22 / 10 10 10 0
PARSONS-KPPF 21 26 7 24 / 20 10 10 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON CST TUESDAY FOR KSZ032-033-
047-048.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
637 PM EST WED DEC 31 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 429 PM EST WED DEC 31 2014
WV IMAGERY AND RUC ANALYSIS INDICATED NW MID/UPPER LEVEL FLOW FROM
NW CANADA INTO THE GREAT LAKES BETWEEN A TROUGH OVER HUDSON BAY AND
A RIDGE FROM THE ERN PACIFIC INTO BC. A SHORTWAVE TROUGH WAS MOVING
THROUGH UPPER MI WITH ANOTHER WEAKER SHRTWV UPSTREAM OVER MANITOBA.
ANOTHER CLIPPER SHRTWV WAS FARTHER UPSTREAM OVER NW SASK. AT THE
SFC...STRONG WEST WINDS PREVAILED ACROSS THE REGION BETWEEN A 988 MB
LOW NEAR HUDSON BAY AND 1036 MB ARCTIC HIGH PRES INTO THE SRN
PLAINS. THE STRONGEST WINDS THIS MORNING INTO EARLY AFTERNOON ACROSS
LAKE SUPERIOR OCCURRED AS THE STRONGER PRES FALLS SLID THROUGH NRN
ONTARIO. WITH 850 MB TEMPS AROUND -19C AND CONVERGENT WRLY FLOW
DEVELOPING LES HAS INCREASED ACROSS THE KEWEENAW AS WINDS VEERED
FROM SW TO W.
TONIGHT...EXPECT THE STRONGEST LOW LEVEL CONV SUPPORTING LES TO
REMAIN OVER THE KEWEENAW. EVEN WITH A FAVORABLE POSITION OF THE DGZ
IN THE CLOUD LAYER...THE STRONGER WINDS WILL CREATE ENOUGH
COMPACTION/FRACTURING TO LIMIT SLR VALUES CLOSER TO 20/1. SO OVERALL
ACCUMULATIONS TONIGHT IN THE 2 TO 5 INCH RANGE ARE EXPECTED. WINDS
GUSTING INTO THE 30 TO 40 MPH RANGE WILL ALSO CONTINUE TO PRODUCE
CONSIDERABLE BLOWING AND DRIFTING SNOW IN OPEN AREAS WHERE OCNL
WHITEOUT CONDITIONS ARE POSSIBLE. WINDS ARE EXPECTED TO DIMINISH
OVERNIGHT REDUCING THE BLSN HAZARDS.
THU...THE NRN SASK SHRTWV TROUGH WILL BRUSH THE AREA WITH ENOUGH
700-500 MB QVECTOR CONV AND 800-600 MB FGEN TO SUPPORT AN AREA OF
LIGHT SNOW FROM NRN MN INTO NRN WI AND UPPER MI. WITH THE LACK OF
SIGNFICANT MOISTURE INFLOW/AVAILABILITY...SNOW AMOUNTS OF A HALF
INCH OR LESS ARE EXPECTED. HOWEVER...THE DEEPER MOISTURE WITH
INCREASING INVERSION HEIGHTS INTO THE AREA WILL SUPPORT GREATER LES
INTENSITY FOR THE W TO WNW FLOW LES SNOW BELTS. SINCE THE STRONGER
LOW LEVEL CONV IS EXPECTED TO SHIFT SOUTHWARD OVERALL SNOW AMOUNTS
SHOULD REMAIN IN THE 1 TO 3 INCH RANGE.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 316 PM EST WED DEC 31 2014
AN UPPER TROUGH OVER EASTERN CANADA LEAD TO COLD AIR AND LAKE
EFFECT SNOW OVER THE NORTHWEST WIND SNOW BELTS TO START THE PERIOD.
THIS LIGHT TO OCCASIONALLY MODERATE LAKE EFFECT SNOW WILL CONTINUE
IN THOSE NORTHWEST WIND BELTS ON THURSDAY NIGHT...BUT AS THE LOW
LEVEL WINDS BACK LATE THURSDAY NIGHT INTO FRIDAY MORNING...WILL
FOCUS THE POPS/SNOW TO THE WEST-NORTHWEST AREAS ON FRIDAY (AND
WESTERLY AREAS LATE FRIDAY AFTERNOON). WHILE LAKE INDUCED
EQUILIBRIUM LEVELS WILL BE AROUND 8KFT...THERE ARE SOME CONCERNS IN
THE AMOUNT OF MOISTURE AVAILABLE AS SUBSIDENCE AND DRIER AIR ARRIVE
THURSDAY NIGHT FROM A HIGH MOVING SOUTHEAST INTO MINNESOTA.
THUS...WILL STICK WITH A DUSTING TO 3-4IN EVERY 12HRS THROUGH
FRIDAY...WITH THE HIGHEST AMOUNTS OVER THE EAST WITH THE LONGER
FETCH AND SOME INDICATIONS OF A LINGERING TROUGH AIDING
CONVERGENCE TOWARDS WHITEFISH POINT. THE HIGH WILL SHIFT SOUTHEAST
OF THE AREA ON FRIDAY EVENING...BACKING WINDS TO THE SOUTHWEST AND
ONLY LEAVING LAKE EFFECT SNOW OVER THE KEWEENAW FOR FRIDAY NIGHT.
THE FOCUS THEN TURNS TO THE INTERACTION AND PHASING OF THE SPLIT
FLOW FOR THE START OF THE WEEKEND. MODELS SEEM TO COMING INTO
BETTER AGREEMENT ON THE OVERALL IDEA FOR THE WEEKEND...ALTHOUGH
THERE ARE STILL SMALLER DIFFERENCES THAT COULD HAVE AN IMPACT ON
THE AMOUNT OF SNOW SEEN OVER PARTS OF THE U.P. THERE ARE TWO
FEATURES AT PLAY FOR THIS WEEKEND...THE FIRST IS THE REMNANTS OF
THE UPPER LOW PRODUCING SNOW OVER THE SOUTHWEST CONUS TODAY AND THE
SECOND FEATURE IS A SHORTWAVE CURRENTLY OVER THE ALEUTIANS ISLANDS
AND DROPPING SOUTHEAST INTO THE NORTHERN ROCKIES ON FRIDAY NIGHT.
THIS WILL LEAD TO A LOW DEVELOPING IN THE LEE OF THE NORTHERN
ROCKIES AND THEN MOVING EAST INTO THE DAKOTAS AND WESTERN MINNESOTA
BY SATURDAY MORNING. EXPECT SNOW TO SPREAD EAST AHEAD OF THIS LOW
AND INTO THE NORTHWEST HALF OF THE CWA...ASSOCIATED WITH STRONG MID
LEVEL WARM AIR ADVECTION. WHILE THE HEAVIEST SNOW APPEARS TO OCCUR
OVER LAKE SUPERIOR...WILL SHOW SOME LIKELY POPS OVER AND AROUND THE
KEWEENAW PENINSULA FOR SATURDAY. AS THAT IS OCCURRING...THE
NORTHERN SHORTWAVE WILL CONTINUE TO DIVE SOUTHEAST AND PHASE WITH
THE SOUTHERN UPPER LOW AND LEAD TO BOTH EJECTING NORTHEAST THROUGH
THE LOWER GREAT LAKES REGION SATURDAY NIGHT INTO SUNDAY. AS
EXPECTED IN THESE PHASING EVENTS...EACH MODEL RUN GIVES A SLIGHTLY
DIFFERENT IDEA ON THE EVOLUTION OF THE PHASED FEATURES AND IN TURN
THE SURFACE FEATURES. OVERALL...THE GENERAL IDEA IS FOR A
STRENGTHENING LOW TO LIFT NORTHEAST THROUGH SOUTHEAST LOWER
MICHIGAN ON SATURDAY NIGHT AND THEN INTO QUEBEC ON SUNDAY. WITH
THAT TRACK...WOULD EXPECT MUCH OF THE SYNOPTIC
FORCING/PRECIPITATION ASSOCIATED WITH THOSE FEATURES TO MISS THE
U.P....BUT WOULD STILL EXPECT AT LEAST SOME LAKE ENHANCEMENT AS THE
WINDS TURN TO THE NORTHWEST BEHIND THE ELONGATED SURFACE TROUGH
STRETCHING NORTH OVER EASTERN LAKE SUPERIOR LATE SATURDAY NIGHT.
INITIALLY...WOULDN/T EXPECT THE LAKE ENHANCEMENT TO AMOUNT TO TOO
HIGH OF SNOWFALL AMOUNTS ON SATURDAY NIGHT...BUT AS MUCH COLDER AIR
MOVES INTO THE AREA (850MB TEMPS FALLING TO -25C BY 00Z MONDAY) AND
THE DEEPER MOISTURE IS STILL PRESENT FROM THE DEPARTING
SYSTEM...WOULD EXPECT THE LAKE ENHANCEMENT/EFFECT SNOW TO TAKE OFF
ON SUNDAY IN THE NORTHWEST WIND SNOW BELTS. WILL TREND POPS UP TO
DEFINITE VALUES DURING THIS PERIOD AND CONTINUE TO MENTION
MODERATE/HEAVY SNOW WORDING IN THE HWO.
BEHIND THE LOW...EXPECT THE FIRST PART OF THE WORK WEEK TO BE VERY
COLD WITH CONTINUED LAKE EFFECT SNOW. THE CANADIAN UPPER TROUGH
WILL SAG SOUTH INTO THE GREAT LAKES REGION AND KEEP THE COLD AIR IN
PLACE (850MB TEMPS IN THE LOW 20C BELOW ZERO)...WITH ANOTHER
SHORTWAVE MOVING THROUGH ON MONDAY NIGHT POTENTIALLY PULLING 850MB
TEMPERATURES CLOSE TO -30C FOR TUESDAY. THAT WILL LEAD TO VERY COLD
HIGH TEMPERATURES FOR MONDAY/TUESDAY...WITH SOME LOCATIONS OVER THE
INTERIOR WEST EVEN STRUGGLING TO RISE ABOVE 0. IN FACT...LOOKING AT
THE 00Z ECMWF ENSEMBLE MEMBERS AT KSAW AND OTHER SITES IN THE
WESTERN/CENTRAL U.P....THERE MAY END UP BEING A 24-36 HOUR PERIOD OF
SUB ZERO TEMPERATURES LATE SUNDAY NIGHT THROUGH AT LEAST TUESDAY
MORNING. THE COMBINATION OF THE COLD TEMPERATURES AT NIGHT (SINGLE
DIGITS AND TEENS BELOW ZERO) AND WINDS IN THE 5-10MPH RANGE WILL
LEAD TO LOW WIND CHILL VALUES MONDAY/TUESDAY MORNINGS AND
POTENTIALLY EVENING WEDNESDAY MORNING. AS LONG AS THE WIND SPEEDS
STAY UP...WOULD EXPECT THE NEED FOR WIND CHILL ADVISORIES AT A
MINIMUM AND WILL CONTINUE TO ADDRESS IN THE HWO.
AS FOR LAKE EFFECT DURING THE FIRST PART OF NEXT WEEK...EXPECT WINDS
TO BACK TO THE WEST ON MONDAY AND WILL FOCUS THE LAKE EFFECT POPS
IN THOSE AREAS. WITH THE AMOUNT OF COLD AIR IN PLACE...VERY LITTLE
OF THE CLOUD LAYER WILL BE IN THE DGZ AND MOST WILL BE ABOVE
IT...WHICH LEADS TO MORE COLUMN/PLATE SNOWFLAKES AND WOULD EXPECT
ACCUMULATIONS TO BE LIMITED. WINDS WILL SHIFT MORE TO THE NORTHWEST
ON TUESDAY BEHIND THAT NEXT SHORTWAVE AND WILL TREND POPS TO THAT
FAVORED WIND DIRECTION. WITH THE AMOUNT OF COLD AIR...THERE
SHOULDN/T BE MUCH OF AN ISSUE FOR AT LEAST SOME LAKE EFFECT...SO
DID TREND POPS UP TO LIKELY-DEFINITE VALUES EVEN THOUGH AMOUNTS
SHOULD BE LIMITED. AS THE UPPER TROUGH SHIFTS EAST ON WEDNESDAY AND
THROUGH THE END OF THE WORK WEEK...THE UPPER GREAT LAKES REGION
SHOULD SEE A MODERATION IN THEIR TEMPERATURES TOWARDS MORE NORMAL
VALUES TOWARDS THE END OF NEXT WEEK. LOOKING AT THE 00Z ECMWF
ENSEMBLE MEAN FOR DAYS 9-15...IT SHOWS MORE OF A ZONAL FLOW ACROSS
THE CONUS...WHICH WOULD TRANSLATE TO MORE NORMAL OR EVEN SLIGHTLY
ABOVE NORMAL TEMPERATURES HEADING INTO THE MIDDLE OF JANUARY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 637 PM EST WED DEC 31 2014
GUSTY WINDS OVER THE KEWEENAW TO KEEP BLSN GOING INTO THE
EVENING HOURS AND COMBINED WITH LES WILL KEEP VISIBILITY IN THE
IFR RANGE AT KCMX...ALTHOUGH THERE MAY BE A FEW PERIODS WHERE VSBYS
RISE INTO THE LOW MVFR RANGE AS SLIGHTLY DRIER AIR WORKS INTO THE
AREA. ONCE WINDS SHIFT MORE TO THE WEST...IFR CONDITIONS WILL
PREVAIL AT KCMX THROUGH THE NIGHT AND INTO THE EARLY DAYLIGHT HOURS.
VFR/MVFR CONDITIONS TO HOLD AT KIWD. VFR CONDITIONS TO CONTINUE AT
KSAW WITH SW TO W DOWNSLOPING FLOW TO PERSIST.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 429 PM EST WED DEC 31 2014
LAKE SUPERIOR WILL BE STUCK BETWEEN VERY STRONG HIGH PRESSURE ACROSS
THE S PLAINS AND A DEEP HUDSON BAY LOW TODAY. GALES OF 35-45KTS WILL
CONTINUE BEFORE SLOWLY DIMINISHING TO 35KTS LATE TONIGHT INTO
THURSDAY MORNING OUT OF THE W-NW. GIVEN PLENTY OF COLD AIR...AND
STRONG WINDS...HEAVY FREEZING SPRAY WILL ALSO BE A CONCERN INTO
THURSDAY.
LOOK FOR THE TROUGH OVER LAKE SUPERIOR TO DEEPEN TONIGHT THROUGH
THURSDAY. THE HUDSON BAY LOW WILL SHIFT AND WEAKEN ACROSS N QUEBEC
THURSDAY NIGHT...ALLOWING THE TROUGH ACROSS LAKE SUPERIOR TO WEAKEN
AS WELL. HIGH PRESSURE SINKING ACROSS MANITOBA AND MINNESOTA
THURSDAY NIGHT WILL BUILD RIDGE ACROSS LAKE SUPERIOR ON FRIDAY AS IT
PROGRESSES ACROSS THE REMAINDER OF THE GREAT LAKES. A WEAK TROUGH
WILL LIKELY LINGER ACROSS MAINLY E LAKE SUPERIOR DURING THIS TIME.
EXPECT A LOW NEAR MONTANA ON FRIDAY TO TRACK ACROSS THE N AND
CENTRAL PLAINS SATURDAY MORNING...AND THE MID MISSISSIPPI VALLEY
SATURDAY AFTERNOON...BEFORE DEEPENING NORTHEASTWARD ACROSS THE LOWER
GREAT LAKES AND QUEBEC LATE SATURDAY NIGHT INTO SUNDAY. THIS WILL
BRING A TROUGH THROUGH THE AREA SATURDAY NIGHT INTO SUNDAY...ALONG
WITH THE POTENTIAL FOR N-NW GALES. HEAVY FREEZING SPRAY WILL
ALSO MAKE A RETURN ACROSS MUCH OF LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST THURSDAY FOR MIZ001-003.
LAKESHORE FLOOD ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR MIZ001-
003.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 4 AM EST /3 AM CST/ THURSDAY
FOR LSZ162-240>245-248>251-263>267.
GALE WARNING UNTIL 10 AM EST THURSDAY FOR LSZ266-267.
GALE WARNING UNTIL 7 AM EST /6 AM CST/ THURSDAY FOR LSZ162-
241>248-263>265.
HEAVY FREEZING SPRAY WARNING UNTIL 1 AM EST THURSDAY FOR LSZ246-
247.
GALE WARNING UNTIL 7 AM EST THURSDAY FOR LSZ249>251.
LAKE MICHIGAN...
HEAVY FREEZING SPRAY WARNING UNTIL 1 AM EST THURSDAY FOR LMZ221-
248-250.
GALE WARNING UNTIL 1 AM EST THURSDAY FOR LMZ221-250.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...RJT
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
559 PM EST TUE DEC 30 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 427 PM EST TUE DEC 30 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A PROMINENT MID/UPPER LEVEL
RIDGE FROM THE ERN PACIFIC INTO BC AND A TROUGH OVER NE CANADA
RESULTING IN NNW FLOW TOWARD NRN ONTARIO AND THE NRN LAKES. A
SHORTWAVE TROUGH AXIS EXTENDED FROM JAMES BAY INTO SE NORTH DAKOTA.
WITH ONLY WEAK FORCING AND LITTLE MOISTURE AVAILABLE...NO PCPN WAS
ASSOCIATED WITH THIS FEATURE. FURTHER UPSTREAM...A STRONGER SHRTWV
WAS MOVING THROUGH NRN SASK/MANITOBA. AT THE SFC...W TO WNW FLOW
PREVAILED ACROSS UPPER MI AND LAKE SUPERIOR AS 1048 MB HIGH PRES
CONTINUES TO SINK THROUGH THE NRN AND CNTRL PLAINS. EVEN WITH 850 MB
TEMPS NEAR -23C...SATELLITE/RADAR INDICATED ONLY LIGHT TO MODERATE
LES INTO NW UPPER MI AND EAST OF MUNISING AS INVERSION HEIGHTS
REMAINED NEAR 4K FT WITH VERY DRY AIR UPSTREAM.
TONIGHT...EXPECT WINDS TO GRADUALLY BACK TO SW AHEAD OF THE
SASK/MANITOBA SHRTWV WHICH WILL PUSH THE LES MOSTLY OFFSHORE.
HOWEVER...ADDITIONAL SNOWFALL AMOUNTS OF 1 TO 3 INCHES NW(KEWEENAW
AND 2 TO 4 INCHES NE (NE OF P53) ARE POSSIBLE. TEMPS FALLING OFF
INTO THE -7F TO -12F RANGE AND WINDS NEAR 10 MPH WILL DROP WIND
CHILLS INTO THE -20 TO -33 RANGE OVER THE INTERIOR WRN HALF WHERE
WIND CHILL ADVISORIES WILL REMAIN IN EFFECT.
WEDNESDAY...AS THE SHRTWV MOVES THROUGH THE NRN LAKES AND DRAGS A
WEAK TROUGH THE AREA...WINDS WILL VEER AGAIN FROM SW TO W BY
AFTERNOON. THIS WILL BRING THE LES INTO THE NRN KEWEENAW BY MIDDAY
AND INTO MUCH OF THE REST OF THE PENINSULA BY MID TO LATE AFTERNOON.
THE COMBINATION OF THE LES AND WIND GUSTS OVER 40 MPH WILL LEAD TO
VERY POOR VSBY WHICH WILL LINGER INTO THE EVENING...PROMPTING THE
ISSUANCE OF AN LES ADVY. ALTHOUGH THERE WILL BE A PERIOD OF DEEPER
MOISTURE THAT SHOULD INTENSIFY LES...THE SHIFTING WIND DIRECTIONS
SHOULD LIMIT OVERALL AMOUNTS TO THE 1 TO 3 INCH RANGE BY EVENING.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 427 PM EST TUE DEC 30 2014
UPPER AIR PATTERN STARTS OUT WITH TROUGHING ANCHORED OVER HUDSON BAY
AND ANOTHER MORE COMPACT TROUGH OVER DESERT SOUTHWEST OF CONUS. ONLY
RIDGING OF NOTE IS OVER THE EASTERN PACIFIC OCEAN INTO FAR WESTERN
CANADA. ATTENTION THIS WEEKEND WILL BE ON THE SOUTHWEST CONUS TROUGH.
MODELS CONTINUE TO FAVOR IDEA THAT AS STRONG JET ENERGY ADVANCES
AHEAD OF TROUGH...IT WILL EMERGE OVER THE SOUTHERN PLAINS ON
SATURDAY AND LIFT OVER THE GREAT LAKES ON SUNDAY. MEANWHILE...ANOTHER
SHORTWAVE WITHIN THE BASE OF LARGER TROUGHING OVER EASTERN CANADA
WILL WORK OVER THE UPPER GREAT LAKES. ONE OR BOTH OF THESE FEATURES
MAY BRING WIDESPREAD SNOW TO UPR MICHIGAN FRIDAY NIGHT THROUGH
SATURDAY NIGHT. THERE IS POTENTIAL THAT THE TWO FEATURES COULD
PHASE...THOUGH THAT IS NOT CERTAIN...AND THAT WOULD RESULT IN
GREATEST CHANCE OF SEEING HIGHER END SNOW EVENT.
NO MATTER HOW IT SHAKES OUT...THERE ARE INDICATIONS VERY CHILLY
AIRMASS...EVEN COLDER THAN ONE CURRENTLY AFFECTING THE REGION...WILL
SETTLE OVER UPR GREAT LAKES BY EARLY NEXT WEEK. BEYOND END OF
EXTENDED THERE ARE SIGNALS THAT RIDGE OVER EAST PACIFIC BREAKS DOWN
AND MORE MILD AIR RETURNS TO MUCH OF THE CONUS. PATTERN SHIFT THE
CFSV2 HAS BEEN SHOWING FOR A WHILE NOW. THUS...OVERALL IT DOES NOT
APPEAR THAT THE UPCOMING COLD WILL BE THAT LONG LASTING.
INTIALLY THE MAIN ISSUE WILL BE THE ONGOING WEST FLOW LAKE EFFECT
AND BLOWING SNOW WITH POOR VSBY OVER THE KEWEENAW. DECENT AGREEMENT
THAT SHORTWAVE DROPPING WNW-ESE OVER LK SUPERIOR AND UPR MICHIGAN
WEDNESDAY EVENING WITH LEADING SFC TROUGH AND ENHANCED CONVERGENCE
AND ADDITIONAL MOISTURE WILL RESULT IN A A BRIEF PERIOD OF MODERATE
TO HEAVY LES. WIND CORE MAX AT 950-925MB OVER 40 KTS WILL BE EASING
BY WEDNESDAY EVENING...BUT MIXED LAYER WINDS UP TO 40 KTS WILL STILL
RESULT IN STRONG/GUSTY WINDS OVER 30 MPH AND BLSN/POOR VSBY.
SOUNDINGS SHOW MARGINAL MOISTURE AND INSTABILITY FOR SIGNIFICANT LES
THOUGH AFTER THE TROUGH PASSAGE WITH INVERSIONS PEAKING AT 5-7 KFT
AGL WEDNESDAY EVENING AND LAKE INDUCED EQL NOT MUCH HIGHER THAN
THAT. MAJORITY OF THE MOIST LAYER IS WITHIN THE DGZ BUT STRONG WINDS
WILL LIKELY CUT DOWN SLR/S. POOR VSBY WILL BE THE BIGGER STORY
COMPARED TO SNOW AMOUNTS. AFTER COORDINATING WITH SHORT TERM
FORECASTER... DECIDED TO GO WITH LAKE EFFECT SNOW ADVISORY FOR SNOW
AND BLOWING SNOW WEDNESDAY AFTN THROUGH EARLY AFTERNOON ON NEW YEARS
DAY. WILL MENTION OCCASIONAL WHITEOUT CONDITIONS IN THE WSW
STATEMENT.
LAKE EFFECT AND BLOWING SNOW BECOME FACTOR LATE WEDNESDAY NIGHT INTO
THURSDAY FOR AREAS FAVORED BY WNW WINDS...ONTONAGON COUNTY OVER THE
WEST AND IN THE SNOW BELTS OF EASTERN HALF OF UPR MICHIGAN. LOOKING
AT ONLY A PURE LES SETUP AS SOUNDINGS SHOW SHARP DRYING ABOVE 8KFT.
TEMPS AT TOP OF INVERSION BLO -20C LEAD TO MARGINAL INSTABILITY GIVEN
WATER TEMPS 2-3C. MOST OF LAKE CONVECTIVE LAYER WILL BE IN THE DGZ
AND WINDS WILL BE DIMINISHING...SO FLUFF FACTOR WILL PLAY MORE OF A
ROLE. OVERALL...ADVY SNOW AMOUNTS SEEM POSSIBLE INTO NEW YEARS DAY
FOR THE WNW FLOW AREAS.
LAKE EFFECT LINGERS FOR WNW FLOW AREAS INTO FRIDAY...BUT WILL
CONTINUE TO DIMINISH AS HIGH PRESSURE RIDGE SLIDES ACROSS WESTERN
GREAT LAKES. COLD WILL SLOWLY EASE...THOUGH TEMPS WELL BLO ZERO
EXPECTED THURSDAY NIGHT OVER INTERIOR CNTRL UPR MICHIGAN. INCREASE
OF MID CLOUDS MAY RESULT IN LESS TEMP DROP OVER WEST CWA.
MAIN QUESTION THIS WEEKEND IS HOW MUCH PHASING OCCURS BTWN
APPROACHING NORTHERN STREAM SHORTWAVE TROUGH AND THE UPPER LOW
OPENING UP AS IT LIFTS INTO THE CNTRL PLAINS FM THE SOUTHWEST CONUS.
SINCE MAJORITY OF JET ENERGY REMAINS AHEAD OF THE SOUTHERN STREAM
TROUGH...WOULD EXPECT IT TO STAY FAIRLY PROGRESSIVE AND HAVE LESS
CHANCE OF PHASING WITH NORTHERN STREAM SYSTEM. EVEN SO...THE
NORTHERN STREAM SHORTWAVE ALONG WITH INCREASING NNE-NNW FLOW WITH
H85 TEMPS BLO -12C SATURDAY NIGHT INTO SUNDAY MAY LEAD TO SEVERAL
INCHES OF SNOW. BEST SHOT OF SYNOPTIC SNOW WOULD BE OVER THE SOUTH
AND EAST CWA WHILE THE GREATEST CHANCE FOR LAKE ENHANCEMENT WOULD BE
OVER THE WEST AND NORTH CENTRAL CWA. TIGHT PRESSURE GRADIENT RESULTS
IN GUSTY WINDS AND BLOWING SNOW AS WELL. MODEL TRENDS FOR THIS
SYSTEM ARE VARIABLE WITH EARLIER RUNS A FEW DAYS AGO SHOWING A
WRAPPED UP SYSTEM AND RECENT RUNS BACKING AWAY FM THAT. LATEST RUNS
SEEM TO BE TRYING TO COME BACK TO AT LEAST A FARTHER WEST TRACK TO
THE SOUTHERN STREAM SYSTEM IF NOT A MORE PHASED SYSTEM. SYSTEM BEARS
WATCHING AS IT COULD RESULT IN SOME HEADLINES.
BEHIND THE SYSTEM...LOOKS VERY COLD WITH H85 TEMPS DOWN TO -28C BY
NEXT MONDAY. INCREASED POPS FOR LAKE EFFECT IN WNW-W FLOW AREAS.
MAJORITY OF LAKE CONVECTIVE LAYER IS AT TEMPS BLO -20C...SO SLR/S
WILL BE LOW AND MAIN PROBLEM COULD BE POOR VSBY. COULD ALSO HAVE
WIND CHILL ISSUES FOR THE FIRST DAY BACK TO SCHOOL AFTER WINTER
VACATION.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 559 PM EST TUE DEC 30 2014
LAKE EFFECT SNOW WILL FAVOR PERSISTENT MVFR CIGS AND IFR/LIFR VSBY
AT CMX THROUGH THE PERIOD. GUSTY WINDS INTO WED MORNING WILL ALSO
REDUCE VSBY WITH BLSN. LAKE EFFECT CLOUDS/SNOW WILL LIFT FAR ENOUGH
TO THE NORTH FOR IMPROVING CONDITIONS TO VFR WHICH WILL LAST INTO
WED AS WINDS BECOME WSW AT IWD. AT SAW...VFR CONDITIONS WILL
CONTINUE THROUGH THE PERIOD. WILL GET GUSTY AT ALL SITES LATE
TONIGHT THROUGH WED.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 427 PM EST TUE DEC 30 2014
WEST TO SOUTHWEST GALES 40-45 KTS ARE EXPECTED OVER MOST OF LK
SUPERIOR BEGINNING LATER TONIGHT WILL SHIFT TO WEST-NORTHWEST GALES
TO 35 KTS LATE WEDNESDAY NIGHT INTO THURSDAY MORNING. IN ADDITION TO
THE GALES... HEAVY FREEZING SPRAY WILL AFFECT MOST OF THE LAKE INTO
THURSDAY. WINDS DIMINISH TO LESS THAN 25 KTS BY FRIDAY...BUT THE
LULL WILL BE BRIEF AS NORTHERLY WINDS INCREASE TO GALES TO 40 KTS
SATURDAY NIGHT INTO SUNDAY. MORE HEAVY FREEZING SPRAY WILL OCCUR AT
THIS TIME AS WELL.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND CHILL ADVISORY FROM 9 PM EST /8 PM CST/ THIS EVENING TO 10
AM EST /9 AM CST/ WEDNESDAY FOR MIZ002-009-010-084.
LAKE EFFECT SNOW ADVISORY FROM 1 PM WEDNESDAY TO 1 PM EST
THURSDAY FOR MIZ001-003.
LAKESHORE FLOOD ADVISORY FROM 6 AM WEDNESDAY TO MIDNIGHT EST
WEDNESDAY NIGHT FOR MIZ001-003.
WIND CHILL ADVISORY FROM 11 PM EST /10 PM CST/ THIS EVENING TO
10 AM EST /9 AM CST/ WEDNESDAY FOR MIZ004-005-011-012.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST /NOON CST/ THURSDAY
FOR LSZ240>245-248>251-263>267.
GALE WARNING FROM 1 AM WEDNESDAY TO 1 PM EST THURSDAY FOR LSZ244-
245-264>267.
GALE WARNING FROM 7 PM WEDNESDAY TO 1 PM EST THURSDAY FOR
LSZ249>251.
GALE WARNING FROM 10 AM WEDNESDAY TO 1 PM EST THURSDAY FOR
LSZ246>248.
HEAVY FREEZING SPRAY WARNING FROM 1 AM WEDNESDAY TO 1 PM EST
THURSDAY FOR LSZ246-247.
GALE WARNING FROM 1 AM EST /MIDNIGHT CST/ WEDNESDAY TO 7 AM EST
/6 AM CST/ THURSDAY FOR LSZ162-241>243-263.
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST /6 AM CST/ THURSDAY
FOR LSZ162.
LAKE MICHIGAN...
HEAVY FREEZING SPRAY WARNING FROM 10 AM WEDNESDAY TO 1 PM EST
THURSDAY FOR LMZ221-248-250.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...07
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
429 PM EST TUE DEC 30 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 427 PM EST TUE DEC 30 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A PROMINENT MID/UPPER LEVEL
RIDGE FROM THE ERN PACIFIC INTO BC AND A TROUGH OVER NE CANADA
RESULTING IN NNW FLOW TOWARD NRN ONTARIO AND THE NRN LAKES. A
SHORTWAVE TROUGH AXIS EXTENDED FROM JAMES BAY INTO SE NORTH DAKOTA.
WITH ONLY WEAK FORCING AND LITTLE MOISTURE AVAILABLE...NO PCPN WAS
ASSOCIATED WITH THIS FEATURE. FURTHER UPSTREAM...A STRONGER SHRTWV
WAS MOVING THROUGH NRN SASK/MANITOBA. AT THE SFC...W TO WNW FLOW
PREVAILED ACROSS UPPER MI AND LAKE SUPERIOR AS 1048 MB HIGH PRES
CONTINUES TO SINK THROUGH THE NRN AND CNTRL PLAINS. EVEN WITH 850 MB
TEMPS NEAR -23C...SATELLITE/RADAR INDICATED ONLY LIGHT TO MODERATE
LES INTO NW UPPER MI AND EAST OF MUNISING AS INVERSION HEIGHTS
REMAINED NEAR 4K FT WITH VERY DRY AIR UPSTREAM.
TONIGHT...EXPECT WINDS TO GRADUALLY BACK TO SW AHEAD OF THE
SASK/MANITOBA SHRTWV WHICH WILL PUSH THE LES MOSTLY OFFSHORE.
HOWEVER...ADDITIONAL SNOWFALL AMOUNTS OF 1 TO 3 INCHES NW(KEWEENAW
AND 2 TO 4 INCHES NE (NE OF P53) ARE POSSIBLE. TEMPS FALLING OFF
INTO THE -7F TO -12F RANGE AND WINDS NEAR 10 MPH WILL DROP WIND
CHILLS INTO THE -20 TO -33 RANGE OVER THE INTERIOR WRN HALF WHERE
WIND CHILL ADVISORIES WILL REMAIN IN EFFECT.
WEDNESDAY...AS THE SHRTWV MOVES THROUGH THE NRN LAKES AND DRAGS A
WEAK TROUGH THE AREA...WINDS WILL VEER AGAIN FROM SW TO W BY
AFTERNOON. THIS WILL BRING THE LES INTO THE NRN KEWEENAW BY MIDDAY
AND INTO MUCH OF THE REST OF THE PENINSULA BY MID TO LATE AFTERNOON.
THE COMBINATION OF THE LES AND WIND GUSTS OVER 40 MPH WILL LEAD TO
VERY POOR VSBY WHICH WILL LINGER INTO THE EVENING...PROMPTING THE
ISSUANCE OF AN LES ADVY. ALTHOUGH THERE WILL BE A PERIOD OF DEEPER
MOISTURE THAT SHOULD INTENSIFY LES...THE SHIFTING WIND DIRECTIONS
SHOULD LIMIT OVERALL AMOUNTS TO THE 1 TO 3 INCH RANGE BY EVENING.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 427 PM EST TUE DEC 30 2014
UPPER AIR PATTERN STARTS OUT WITH TROUGHING ANCHORED OVER HUDSON BAY
AND ANOTHER MORE COMPACT TROUGH OVER DESERT SOUTHWEST OF CONUS. ONLY
RIDGING OF NOTE IS OVER THE EASTERN PACIFIC OCEAN INTO FAR WESTERN
CANADA. ATTENTION THIS WEEKEND WILL BE ON THE SOUTHWEST CONUS TROUGH.
MODELS CONTINUE TO FAVOR IDEA THAT AS STRONG JET ENERGY ADVANCES
AHEAD OF TROUGH...IT WILL EMERGE OVER THE SOUTHERN PLAINS ON
SATURDAY AND LIFT OVER THE GREAT LAKES ON SUNDAY. MEANWHILE...ANOTHER
SHORTWAVE WITHIN THE BASE OF LARGER TROUGHING OVER EASTERN CANADA
WILL WORK OVER THE UPPER GREAT LAKES. ONE OR BOTH OF THESE FEATURES
MAY BRING WIDESPREAD SNOW TO UPR MICHIGAN FRIDAY NIGHT THROUGH
SATURDAY NIGHT. THERE IS POTENTIAL THAT THE TWO FEATURES COULD
PHASE...THOUGH THAT IS NOT CERTAIN...AND THAT WOULD RESULT IN
GREATEST CHANCE OF SEEING HIGHER END SNOW EVENT.
NO MATTER HOW IT SHAKES OUT...THERE ARE INDICATIONS VERY CHILLY
AIRMASS...EVEN COLDER THAN ONE CURRENTLY AFFECTING THE REGION...WILL
SETTLE OVER UPR GREAT LAKES BY EARLY NEXT WEEK. BEYOND END OF
EXTENDED THERE ARE SIGNALS THAT RIDGE OVER EAST PACIFIC BREAKS DOWN
AND MORE MILD AIR RETURNS TO MUCH OF THE CONUS. PATTERN SHIFT THE
CFSV2 HAS BEEN SHOWING FOR A WHILE NOW. THUS...OVERALL IT DOES NOT
APPEAR THAT THE UPCOMING COLD WILL BE THAT LONG LASTING.
INTIALLY THE MAIN ISSUE WILL BE THE ONGOING WEST FLOW LAKE EFFECT
AND BLOWING SNOW WITH POOR VSBY OVER THE KEWEENAW. DECENT AGREEMENT
THAT SHORTWAVE DROPPING WNW-ESE OVER LK SUPERIOR AND UPR MICHIGAN
WEDNESDAY EVENING WITH LEADING SFC TROUGH AND ENHANCED CONVERGENCE
AND ADDITIONAL MOISTURE WILL RESULT IN A A BRIEF PERIOD OF MODERATE
TO HEAVY LES. WIND CORE MAX AT 950-925MB OVER 40 KTS WILL BE EASING
BY WEDNESDAY EVENING...BUT MIXED LAYER WINDS UP TO 40 KTS WILL STILL
RESULT IN STRONG/GUSTY WINDS OVER 30 MPH AND BLSN/POOR VSBY.
SOUNDINGS SHOW MARGINAL MOISTURE AND INSTABILITY FOR SIGNIFICANT LES
THOUGH AFTER THE TROUGH PASSAGE WITH INVERSIONS PEAKING AT 5-7 KFT
AGL WEDNESDAY EVENING AND LAKE INDUCED EQL NOT MUCH HIGHER THAN
THAT. MAJORITY OF THE MOIST LAYER IS WITHIN THE DGZ BUT STRONG WINDS
WILL LIKELY CUT DOWN SLR/S. POOR VSBY WILL BE THE BIGGER STORY
COMPARED TO SNOW AMOUNTS. AFTER COORDINATING WITH SHORT TERM
FORECASTER... DECIDED TO GO WITH LAKE EFFECT SNOW ADVISORY FOR SNOW
AND BLOWING SNOW WEDNESDAY AFTN THROUGH EARLY AFTERNOON ON NEW YEARS
DAY. WILL MENTION OCCASIONAL WHITEOUT CONDITIONS IN THE WSW
STATEMENT.
LAKE EFFECT AND BLOWING SNOW BECOME FACTOR LATE WEDNESDAY NIGHT INTO
THURSDAY FOR AREAS FAVORED BY WNW WINDS...ONTONAGON COUNTY OVER THE
WEST AND IN THE SNOW BELTS OF EASTERN HALF OF UPR MICHIGAN. LOOKING
AT ONLY A PURE LES SETUP AS SOUNDINGS SHOW SHARP DRYING ABOVE 8KFT.
TEMPS AT TOP OF INVERSION BLO -20C LEAD TO MARGINAL INSTABILITY GIVEN
WATER TEMPS 2-3C. MOST OF LAKE CONVECTIVE LAYER WILL BE IN THE DGZ
AND WINDS WILL BE DIMINISHING...SO FLUFF FACTOR WILL PLAY MORE OF A
ROLE. OVERALL...ADVY SNOW AMOUNTS SEEM POSSIBLE INTO NEW YEARS DAY
FOR THE WNW FLOW AREAS.
LAKE EFFECT LINGERS FOR WNW FLOW AREAS INTO FRIDAY...BUT WILL
CONTINUE TO DIMINISH AS HIGH PRESSURE RIDGE SLIDES ACROSS WESTERN
GREAT LAKES. COLD WILL SLOWLY EASE...THOUGH TEMPS WELL BLO ZERO
EXPECTED THURSDAY NIGHT OVER INTERIOR CNTRL UPR MICHIGAN. INCREASE
OF MID CLOUDS MAY RESULT IN LESS TEMP DROP OVER WEST CWA.
MAIN QUESTION THIS WEEKEND IS HOW MUCH PHASING OCCURS BTWN
APPROACHING NORTHERN STREAM SHORTWAVE TROUGH AND THE UPPER LOW
OPENING UP AS IT LIFTS INTO THE CNTRL PLAINS FM THE SOUTHWEST CONUS.
SINCE MAJORITY OF JET ENERGY REMAINS AHEAD OF THE SOUTHERN STREAM
TROUGH...WOULD EXPECT IT TO STAY FAIRLY PROGRESSIVE AND HAVE LESS
CHANCE OF PHASING WITH NORTHERN STREAM SYSTEM. EVEN SO...THE
NORTHERN STREAM SHORTWAVE ALONG WITH INCREASING NNE-NNW FLOW WITH
H85 TEMPS BLO -12C SATURDAY NIGHT INTO SUNDAY MAY LEAD TO SEVERAL
INCHES OF SNOW. BEST SHOT OF SYNOPTIC SNOW WOULD BE OVER THE SOUTH
AND EAST CWA WHILE THE GREATEST CHANCE FOR LAKE ENHANCEMENT WOULD BE
OVER THE WEST AND NORTH CENTRAL CWA. TIGHT PRESSURE GRADIENT RESULTS
IN GUSTY WINDS AND BLOWING SNOW AS WELL. MODEL TRENDS FOR THIS
SYSTEM ARE VARIABLE WITH EARLIER RUNS A FEW DAYS AGO SHOWING A
WRAPPED UP SYSTEM AND RECENT RUNS BACKING AWAY FM THAT. LATEST RUNS
SEEM TO BE TRYING TO COME BACK TO AT LEAST A FARTHER WEST TRACK TO
THE SOUTHERN STREAM SYSTEM IF NOT A MORE PHASED SYSTEM. SYSTEM BEARS
WATCHING AS IT COULD RESULT IN SOME HEADLINES.
BEHIND THE SYSTEM...LOOKS VERY COLD WITH H85 TEMPS DOWN TO -28C BY
NEXT MONDAY. INCREASED POPS FOR LAKE EFFECT IN WNW-W FLOW AREAS.
MAJORITY OF LAKE CONVECTIVE LAYER IS AT TEMPS BLO -20C...SO SLR/S
WILL BE LOW AND MAIN PROBLEM COULD BE POOR VSBY. COULD ALSO HAVE
WIND CHILL ISSUES FOR THE FIRST DAY BACK TO SCHOOL AFTER WINTER
VACATION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1249 PM EST TUE DEC 30 2014
LAKE EFFECT SNOW WILL FAVOR PERSISTENT MVFR CIGS AND IFR/LIFR VSBY
AT CMX UNTIL LATE TONIGHT WHEN WINDS BACKING TO SAW WILL PUSH THE
LES BANDS OFFSHORE. GUSTY WINDS INTO WED MORNING WILL ALSO REDUCE
VSBY WITH BLSN EVEN AS THE LES REMAINS MAINLY OFFSHORE.
LAKE EFFECT CLOUDS/SNOW WILL REMAIN NEAR IWD THROUGH THIS AFTERNOON
BUT MAY LIFT FAR ENOUGH TO THE NORTH FOR IMPROVING CONDITIONS TO VFR
WHICH WILL LAST INTO WED AS WINDS BECOME WSW. AT SAW...MVFR CIGS
WITH SOME LIGHT SNOW SHOWERS OR FLURRIES WILL ALSO GIVE WAY TO
CLEARING WITH VFR CONDITIONS THIS EVENING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 427 PM EST TUE DEC 30 2014
WEST TO SOUTHWEST GALES 40-45 KTS ARE EXPECTED OVER MOST OF LK
SUPERIOR BEGINNING LATER TONIGHT WILL SHIFT TO WEST-NORTHWEST GALES
TO 35 KTS LATE WEDNESDAY NIGHT INTO THURSDAY MORNING. IN ADDITION TO
THE GALES... HEAVY FREEZING SPRAY WILL AFFECT MOST OF THE LAKE INTO
THURSDAY. WINDS DIMINISH TO LESS THAN 25 KTS BY FRIDAY...BUT THE
LULL WILL BE BRIEF AS NORTHERLY WINDS INCREASE TO GALES TO 40 KTS
SATURDAY NIGHT INTO SUNDAY. MORE HEAVY FREEZING SPRAY WILL OCCUR AT
THIS TIME AS WELL.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND CHILL ADVISORY FROM 9 PM EST /8 PM CST/ THIS EVENING TO 10
AM EST /9 AM CST/ WEDNESDAY FOR MIZ002-009-010-084.
LAKE EFFECT SNOW ADVISORY FROM 1 PM WEDNESDAY TO 1 PM EST
THURSDAY FOR MIZ001-003.
WIND CHILL ADVISORY FROM 11 PM EST /10 PM CST/ THIS EVENING TO
10 AM EST /9 AM CST/ WEDNESDAY FOR MIZ004-005-011-012.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST /NOON CST/ THURSDAY
FOR LSZ240>245-248>251-263>267.
GALE WARNING FROM 1 AM WEDNESDAY TO 1 PM EST THURSDAY FOR LSZ244-
245-264>267.
GALE WARNING FROM 7 PM WEDNESDAY TO 1 PM EST THURSDAY FOR
LSZ249>251.
GALE WARNING FROM 10 AM WEDNESDAY TO 1 PM EST THURSDAY FOR
LSZ246>248.
HEAVY FREEZING SPRAY WARNING FROM 1 AM WEDNESDAY TO 1 PM EST
THURSDAY FOR LSZ246-247.
GALE WARNING FROM 1 AM EST /MIDNIGHT CST/ WEDNESDAY TO 7 AM EST
/6 AM CST/ THURSDAY FOR LSZ162-241>243-263.
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST /6 AM CST/ THURSDAY
FOR LSZ162.
LAKE MICHIGAN...
HEAVY FREEZING SPRAY WARNING FROM 10 AM WEDNESDAY TO 1 PM EST
THURSDAY FOR LMZ221-248-250.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...JLB
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1133 PM EST MON DEC 29 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 403 PM EST MON DEC 29 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH
EXTENDING FROM NRN QUEBEC THROUGH THE NRN PLAINS INTO THE ROCKIES.
THE NEXT SIGNIFICANT UPSTREAM SHORTWAVE TROUGH WAS DROPPING SOUTH
THROUGH NRN SASK/MANITOBA. AT THE SFC...1054 MB ARCTIC HIGH PRES OVER
ALBERTA EXTENDED INTO THE NRN PLAINS AND UPPER MS VALLEY AND NRN
LAKES RESULTING IN A FLOW OF VERY COLD AIR ACROSS LAKE SUPERIOR ON
NW WINDS. DESPITE 850 MB TEMPS NEAR -21C...LES HAS BEEN LIMITED BY
THE VERY DRY UPSTREAM CONDITIONS AS THE BACK EDGE OF THE CLOUDS WAS
CLOSER TO THE MI SHORE IN THE WEST AND NEAR THE CENTER OF THE NRN
LAKE. RADAR SHOWED MAINLY WEAK WIND PARALLEL BANDS INTO THE ERN
CWA.
TONIGHT...WITH THE LOSS OF DAYTIME MIXING AND ONSET OF LAND BREEZES
THE LES MAY BECOME BETTER ORGANIZED. THE PERSISTENT 290-300 FLOW LES
IS EXPECTED TO CONTINUE BUT WILL BE LIMITED BY 4K FT INVERSION
HEIGHTS AND A LACK OF ANY SUSTAINED AREAS OF LOW LEVEL CONV. THE LONGER
FETCH INTO THE EAST WILL SUPPORT SNOWFALL AMOUNTS IN THE 2 TO 4 INCH
RANGE WITH SLR VALUES NEAR 25/1...E OF MUNISING WHILE OVER THE WEST
ONLY 1 TO 3 INCH AMOUNTS ARE EXPECTED. WIND CHILL VALUES OVER THE
INTERIOR WEST COULD FALL INTO THE -20 TO -25 RANGE AS SFC TEMPS DROP
TO AROUND -8F. HOWEVER...WINDS SHOULD REMAIN LESS THAN 10 MPH.
TUESDAY...EXPECT THE WINDS TO BACK MORE WRLY AHEAD OF THE
SASK/MANITOBA SHORTWAVE TROUGH...ESPECIALLY IN THE AFTERNOON.
OTHERWISE...LIGHT TO MODERATE WNW FLOW LES WILL CONTINUE WITH 850 MB
TEMPS REMAINING NEAR -22C AND INVERSION HEIGHTS AROUND 4K FT. THE
STRONGEST LOW LEVEL CONV...INFLUENCED BY LAKE-INDUCED TROUGHING IS
EXPECTED OVER THE ERN LAKE WITH SOME STRONGER BANDS POSSIBLE
CLIPPING THE NE PORTION OF LUCE COUNTY. FOR NOW...EXPECT ADDITIONAL
ACCUMULATIONS IN THE 2 TO 4 INCH RANGE E OF P53 AND 1 TO 3 INCHES
INTO THE WEST.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 426 PM EST MON DEC 29 2014
A BROAD UPPER TROUGH OVER CANADA AND THE GREAT LAKES REGION WILL
LEAD TO BELOW NORMAL TEMPERATURES AND PERIODS OF LAKE EFFECT SNOW
THROUGH THE FIRST WEEK OF 2015.
AT THE START OF THE PERIOD...THE AREA WILL STILL BE BETWEEN A
STRONG HIGH OVER WESTERN NEBRASKA AND A LOW JUST TO THE NORTH OF
HUDSON BAY. ALOFT...A SHORTWAVE WILL JUST BE DEPARTING THE AREA AND
BRINGING ONE LAST SURGE OF -21C 850MB TEMPS TO THE AREA.
THUS...EXPECT NORTHWEST FLOW LAKE EFFECT TO STILL BE ONGOING
TUESDAY EVENING. A SURFACE TROUGH DIVING SOUTHEAST FROM THE HUDSON
BAY LOW WILL LEAD TO BACKING FLOW ON TUESDAY NIGHT INTO WEDNESDAY
MORNING...SHIFTING THE LAKE EFFECT TO THE WESTERLY FLOW AREAS (THE
KEWEEANW AND RIGHT ALONG THE LAKE SUPERIOR SHORELINE EAST OF
MUNISING). SNOWFALL AMOUNTS TUESDAY NIGHT CONTINUE TO LOOK LIGHT
AND FLUFFY AS INVERSION HEIGHTS ARE STILL IN THE 4-5KFT RANGE WITH
MUCH OF THE CLOUD LAYER IN THE DGZ. WILL FOLLOW THE SNOWFALL
AMOUNTS SEEN OVER THE LAST 12/24HRS AND HAVE THEM BE IN THE
1-4IN/12HRS RANGE.
TUESDAY NIGHT WILL BE ANOTHER COLD NIGHT AWAY FROM THE LAKE EFFECT
CLOUDS...WITH LOWS FALLING INTO THE SINGLE DIGITS AND LOWER TEENS
BELOW ZERO. WIND CHILLS WILL BECOME A CONCERN LATE IN THE NIGHT
INTO WEDNESDAY MORNING...AS THE WEST TO SOUTHWEST WINDS BEGIN TO
INCREASE WITH THE TIGHTENING PRESSURE GRADIENT. WHILE THIS WILL
LIKELY INCREASE MIXING AND IN TURN WARM TEMPS SLIGHTLY (HELPED BY
SOME MID CLOUDS MOVING IN)...THERE WILL STILL BE A PERIOD LATE
TUESDAY NIGHT INTO WEDNESDAY MORNING WHERE WIND CHILL VALUES WILL BE
IN THE -20 TO -30 DEGREE RANGE OVER THE INTERIOR LOCATIONS. WILL
CONTINUE TO MENTION THIS IN THE HWO AND AN ADVISORY MAY BEEN
NEEDED TOMORROW.
WITH THE LOW LEVEL WINDS TRYING TO BACK TOWARDS THE SOUTHWEST
DURING THE DAY WEDNESDAY...DID TRY TO SHOW BETTER TIMING ON THE
LAKE EFFECT SNOW. EXPECT IT TO TRY TO SHIFT OVER THE FAR NORTHERN
PART OF THE KEWEENAW BY MID DAY AND WELL OFFSHORE OVER THE
EAST. WINDS WILL BECOME QUITE GUSTY DURING THIS PERIOD...WITH MUCH
OF UPPER MICHIGAN EXPERIENCING GUSTS IN THE 25 TO 35MPH RANGE. BUT
OVER THE KEWEENAW PENINSULA AND CLOSER TO THE TIGHTER PRESSURE
GRADIENT...WOULD EXPECT GUSTS TO AT LEAST 40 MPH AND AT TIMES
45-50MPH. THESE WINDS COMBINED WITH THE FLUFFY LAKE EFFECT SEEN
OVER THE LAST COUPLE OF DAYS WILL LIKELY LEAD TO SIGNIFICANT
BLOWING SNOW DEVELOPING THROUGH THE DAY WEDNESDAY. THEN...AS STRONG
SHORTWAVE DIVES SOUTHEAST ACROSS THE UPPER GREAT LAKES REGION DURING
THE AFTERNOON AND THE SURFACE TROUGH DURING THE EARLY
EVENING...EXPECT WINDS TO SHIFT BACK TO THE WEST AND REFOCUS THE
LAKE EFFECT IN THE WESTERLY WIND AREAS. THINK THERE COULD BE A
PERIOD OF MODERATE SNOW AS THE WINDS TURN TO THE WEST...DUE TO
INVERSION HEIGHTS RISING TO 7KFT AND MUCH OF THE CLOUD STILL IN THE
DGZ. THERE ARE A COUPLE DOWNSIDES TO HIGHER SNOWFALL AMOUNTS (TIED
TO THE STRONG WINDS)...BUT THERE WILL STILL BE VERY POOR CONDITIONS
OVER THE KEWEENAW. FIRST...THE HIGH WINDS WILL LIMIT THE RESIDENCE
TIME OVER THE WESTERN LAKE AS THEY SHIFT TO THE WEST. SECOND...THE
STRONG WINDS WILL BREAK UP THE DENDRITES FROM THE FAVORABLE CLOUD
LAYER AND LEAD TO SMALLER/FRACTURED FLAKES. WHILE THIS WILL LIMIT
SNOWFALL AMOUNTS...IT WILL BE MORE EFFECTIVE AT REDUCING
VISIBILITIES AND WHEN COMBINED WITH THE BLOWING SNOW...WOULD EXPECT
VISIBILITIES BELOW 1/4 MILE AT TIMES LATE WEDNESDAY AFTERNOON INTO
WEDNESDAY NIGHT. WILL CONTINUE TO MENTION THESE POOR CONDITIONS FOR
THE KEWEENAW IN THE HWO.
EXPECT NORTHWEST FLOW LAKE EFFECT TO REESTABLISH ON THURSDAY FOR
AREAS DOWNSTREAM FROM LAKE SUPERIOR. ELSEWHERE IN THE U.P...MODELS
DIFFER IN THEIR SOLUTIONS ON POTENTIAL SHORTWAVES ZIPPING
EAST-SOUTHEAST ACROSS THE AREA. AT TIMES...MODELS HAVE SHOWN LIGHT
SNOW ASSOCIATED WITH THESE QUICK WAVES THURSDAY AND AGAIN FRIDAY.
BOTH STRENGTH AND LOCATIONS HAS NOT BEEN CONSISTENT IN THE MODELS
OVER THE LAST 24 HOURS...SO WILL FOCUS LARGELY ON LAKE EFFECT
TURNING TO THE WESTERLY WIND LOCATIONS AND SHOW SLIGHT CHANCES
ELSEWHERE.
THE UNCERTAINTY CONTINUES INTO THE WEEKEND...AS MODELS DIFFER ON HOW
THE CLOSED UPPER LOW THAT DEVELOPS OVER THE SOUTHWEST CONUS TUESDAY
INTERACTS WITH THE NORTHERN STREAM JET AS IT SHIFTS EAST ACROSS THE
SOUTHERN CONUS. THE 12Z GFS/GEM SOLUTIONS MERGE THE UPPER LOW WITH
A MORE AMPLIFIED NORTHERN STREAM TROUGH AND THEN LIFT IT AND A
DEVELOPING SURFACE LOW NORTHEAST THROUGH THE LOWER GREAT LAKES
SATURDAY NIGHT. MEANWHILE...THE 12Z ECMWF AND ITS ENSEMBLE MEMBERS
SHOW A MUCH FLATTER NORTHERN STREAM TROUGH AND DON/T MERGE THE
WAVES UNTIL THE EAST COAST ON SUNDAY. THAT WOULD LEAD TO MORE OF A
NORTHERLY FLOW LAKE EFFECT FOR THE AREA. THIS WILL DEFINITELY BE
SOMETHING TO WATCH OVER THE COMING DAYS. EVEN IF THERE ISN/T A LOW
MOVING THROUGH THE LOWER GREAT LAKES...TEMPERATURES WILL BE COLD
ENOUGH FOR LAKE EFFECT SNOW AND WILL CONTINUE TO SHOW THE POTENTIAL
IN THE GRIDS FOR AREAS NEAR LAKE SUPERIOR.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1133 PM EST MON DEC 29 2014
EXPECT MAINLY MVFR CONDITIONS AT IWD/CMX THROUGH THE PERIOD...WITH
BETTER CONDITIONS AT SAW. THERE COULD BE TEMPORARY IFR CONDITIONS
FOR VISIBILITY IN THE HEAVIER SNOW SHOWERS ESPECIALLY AT CMX. LIKE
LAST NIGHT...THERE WILL BE TEMPORARY MVFR CIGS AT SAW OVERNIGHT.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 403 PM EST MON DEC 29 2014
EXPECT HEAVY FREEZING SPRAY BY TUESDAY AFTERNOON AND GALES FROM LATE
TUESDAY NIGHT THROUGH THURSDAY MORNING.
A RIDGE ACROSS THE UPPER GREAT LAKES WILL BUILD TUESDAY...AS VERY
STRONG ARCTIC HIGH PRESSURE INITIALLY AT 31.3 INCHES OVER SW CANADA
SINKS ACROSS MONTANA. LOOK FOR THE RIDGE OVER LAKE SUPERIOR TO SINK
SOUTH TUESDAY NIGHT. THIS WILL BE AS A HUDSON BAY LOW DRAGS A TROUGH
ACROSS LAKE SUPERIOR. THE LOW WILL DEEPEN OVER S HUDSON BAY
WEDNESDAY NIGHT AS IT BRINGS A REINFORCING TROUGH ACROSS LAKE
SUPERIOR. W GALES OF 35-45KTS ARE STILL ANTICIPATED /ALONG WITH
HEAVY FREEZING SPRAY TUESDAY NIGHT THROUGH THURSDAY MORNING AS
THE PRESSURE GRADIENT TIGHTENS BETWEEN THE EXITING HIGH TO THE S AND
STRONG LOW TO THE N. LOOK FOR THE LOW TO SHIFT ACROSS N QUEBEC AND
WEAKEN SIGNIFICANTLY THURSDAY NIGHT. HIGH PRESSURE WILL THEN BUILD
SE ACROSS SASKATCHEWAN AND S MANITOBA ON THURSDAY AND FRIDAY AS A
RIDGE TRACKS ACROSS THE UPPER GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING FROM 1 PM EST /NOON CST/ TUESDAY TO
1 PM EST /NOON CST/ THURSDAY FOR LSZ240>243-248>251-263-
265>267.
GALE WARNING FROM 1 AM WEDNESDAY TO 1 PM EST THURSDAY FOR LSZ244-
245-264>267.
HEAVY FREEZING SPRAY WARNING FROM 7 PM EST /6 PM CST/ TUESDAY TO
7 AM EST /6 AM CST/ THURSDAY FOR LSZ162.
GALE WARNING FROM 1 AM EST /MIDNIGHT CST/ WEDNESDAY TO 7 AM EST
/6 AM CST/ THURSDAY FOR LSZ162-241>243-263.
HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST THURSDAY FOR LSZ244-
245-264.
HEAVY FREEZING SPRAY WARNING FROM 1 AM WEDNESDAY TO 1 PM EST
THURSDAY FOR LSZ246-247.
LAKE MICHIGAN...
HEAVY FREEZING SPRAY WARNING FROM 10 AM WEDNESDAY TO 1 PM EST
THURSDAY FOR LMZ221-248-250.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
924 PM EST WED DEC 31 2014
.SYNOPSIS...
A COLD FRONT WILL BRING THE POTENTIAL FOR LAKE SNOWS NORTH OF THE
NEW YORK THRUWAY THURSDAY NIGHT AND FRIDAY. ON SATURDAY AFTERNOON, A
STORM SYSTEM WILL MOVE IN FROM THE OHIO VALLEY, BRINGING A MIX OF
RAIN AND SNOW SATURDAY NIGHT.
&&
.NEAR TERM /UNTIL 8 AM THURSDAY MORNING/...
920 PM UPDATE...
THE LAKE EFFECT SNOW BAND OVER THE NORTH COUNTRY IS PROGGED TO
SKIRT NORTHERN ONEIDA COUNTY BETWEEN 7Z AND 10Z, BRINGING LIGHT
SNOW ACCUMULATION.
LATEST HRRR OUTPUT SUGGESTS A FEW FLURRIES OR LIGHT SNOW SHOWERS
MAY SNEAK INTO NORTHWESTERN STEUBEN COUNTY OVERNIGHT, DUE TO A
FLUCTUATING ERIE BAND. ADDED A SLIGHT CHC POP.
INTERIOR VALLEY TEMPERATURES ARE ALREADY NEAR PROJECTED OVERNIGHT
MINS, SO HAVE ADJUSTED MINS DOWNWARD.
1255 PM UPDATE...
LAKE SNOWS HV EXITED NRN ONEIDA CNTY THUS HV CANCELLED THE WARNING.
EXPECT LK EFFECT SNOW TO RMN WELL TO THE NORTH ON 240-250 FLOW THRU
THE OVRNGT WITH A SLIGHT WOBBLE TO THE SOUTH POSSIBLE TWD 09Z WITH
PERHAPS A FEW LGT SNOW SHOWERS AND/OR FLURRIES SNEAKING INTO EXTREME
NRN ONEIDA THRU DAYBREAK. VRY MINIMAL ACCUMS ARE EXPECTED WITH THIS
WOBBLE.
EXPECTING THAT LK ERIE BAND WL STAY A TAD TOO FAR WEST TO AFFECT
FINGER LAKES THIS EVNG INTO THE OVRNGT. NOTHING MORE THAN CLD CVR
EXPECTED ON 240 DEGREE FLOW. EXPECT MINS TO DROP INTO THE LWR TEENS
BY MRNG WITH SINGLE DIGITS POSSIBLE IN NOTORIOUSLY COLDER VALLEYS.
&&
.SHORT TERM /8 AM THURSDAY MORNING THROUGH SATURDAY/...
245 PM UPDATE...
LAKE EFFECT SNOW WL RMN NORTH OF CWA FOR MOST OF TOMORROW. THERE IS
SOME INDICATION THAT SNOW BAND WL MAKE A RUN TWD THE SOUTH ARND 18Z
BUT QUICKLY RETREAT BACK TO THE NORTH AS WINDS BACK TWD THE SOUTH
AHD OF APPCHG CDFNT. HV MAINLY CONFINED 20-30 POPS FOR LOCATIONS
NORTH OF THE NY THRUWAY DRG THE AFTN HRS. AS WINDS GO SRLY TEMPS WL
WARM INTO THE 20S BY AFTN, WRMR THAN TDA THO STILL BLO NRML VALUES.
CDFNT WL SLIP SOUTH THRU SRN CANADA LATE THUR NGT WITH LK SNOWS
DVLPNG AHD OF AND ALONG THIS BNDRY. MODELS SEEM TO BE IN PRETTY GOOD
AGREEMENT WITH FROPA WITH ONLY SVR HRS DIFFERENCE ON TIMING. THUS
EXPECT LK EFFECT SNOW SHOWERS TO COMMENCE LATE EVNG AND TWD MIDNIGHT
WITH LKLY BAND OF SNOW SHOWERS DROPPING INTO NRN ONEIDA AFTER 08Z.
WL ALLOW LATER SHIFTS TO GET A BETTER HANDLE ON ANY POTENTIAL
HEADLINES FOR LK EFFECT EVENT TOMORROW NIGHT/FRI MRNG. GFS AND NAM
DIFFER ON HOW LONG FLOW WL BE ALIGNED FOR FAVORABLE LK SNOWS ON
FRIDAY. NAM PUSHES FRONT THRU QUICKLY AND ALLOWS DRIER AIR TO
DISRUPT SNOWS DRG THE AFTN WHILE GFS KEEP INVERSION UP ARND 800MB
DRG THE AFTN HRS WITH FAIRLY STEADY STATE 280 DEGREE FLOW. FEEL IT
PRUDENT TO HOLD OFF ON ANY HEADLINES AT THIS TIME DUE TO VARYING
DEGREES OF UNCERTAINTY.
SFC HIPRES WL BEGIN BUILDING IN LATE FRI NGT THO SOME REMNANT SNOWS
MAY STILL EXIST NORTH OF THE THRUWAY THRU 06Z SAT. QUIET WX EXPECTED
UNTIL SYSTEM MVS IN FM THE SOUTH AFT 18Z SATURDAY. COLD AIR DAMMING
PROGGED ACRS ERN ZONES THRU END OF SHORT TERM PD THUS PCPN WL MV IN
AS ALL SNOW THRU 00Z SUN.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
MAIN FOCUS CONTINUES TO BE EARLY IN THE PERIOD WITH MED RANGE
MODELS IN PRETTY GOOD SYNOPTIC AGREEMENT THAT A PHASING SOUTHERN
STREAM/NORTHERN STREAM TROF WILL EJECT A SFC LOW THROUGH THE GREAT
LAKES REGION AND EASTERN ONTARIO/QUEBEC ON SATURDAY NIGHT AND
SUNDAY. THIS IS, OF COURSE, A TRACK THAT SIGNALS A SNOW-TO-MIX-TO-RAIN
EVENT FOR CNY/NEPA...FOLLOWED BY A DRY SLOT AND SHOWERY
PRECIPITATION ON THE BACK SIDE SUN-MON. GIVEN THE MODEL AGREEMENT
AND TRENDS...THIS IS A FAIRLY HIGH CONFIDENCE EVENT SO WILL
CONTINUE WITH CAT POP ALREADY OFFERED BY PREVIOUS FCST.
BEYOND MONDAY...A BROAD UPPER LEVEL TROF RESIDENT ACROSS THE
NORTHEAST AND GTLKS WILL MAINTAIN A COLD AND UNSTABLE WEST-NW FLOW
WITH TRANSIENT UPPER LEVEL WAVES GENERATING PERIODS OF LAKE SNOW
RESPONSES TO THE EAST OF ERIE AND ONTARIO. HAVE PRETTY MUCH
CONSTANT CHANCES FOR SNOW SHOWERS OR FLURRIES GOING THROUGH WEDNESDAY.
WITH THE EXCEPTION OF AN ABNORMALLY MILD SUNDAY...TEMPERATURES
WILL BE AT OR BELOW NORMAL DURING THIS TIME.
&&
.AVIATION /02Z THURSDAY THROUGH MONDAY/...
VFR IS EXPECTED FOR THE NEXT 24 HOURS. AT KSYR/KRME, BKN CIGS
AROUND 4K FT ARE FORECAST THROUGH THE PERIOD FROM LAKE CLOUDS OFF
LAKE ERIE. REST OF TAF SITES JUST SCT CLOUDS AROUND 5K FT OR SCT CI.
SOUTHWEST WINDS AROUND 10 KNOTS AND GUSTING AT KSYR NEAR 20 KNOTS.
WINDS WILL INCREASE THURSDAY MORNING AT 10-15 KNOTS WITH GUSTS UP
TO 25 KNOTS.
OUTLOOK...
FRI...VFR. LOCAL MVFR CIG/VSBY IN LE SNOW SHOWERS VCNTY KRME-
KSYR...PSBL KITH.
SAT/SAT NGT...BECOMING IFR WITH SNOW DEVELOPING...CHANGING TO
WINTRY MIX AND OCNL RAIN/FRZG RAIN OVERNIGHT.
SUN...VFR. SCT RAIN SHOWERS.
MON...MVFR. SCT SNOW SHOWERS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJP/PVF
NEAR TERM...DJP/PVF
SHORT TERM...PVF
LONG TERM...JAB
AVIATION...RRM
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1233 PM CST TUE DEC 30 2014
.UPDATE...
ISSUED AT 1235 PM CST TUE DEC 30 2014
WE HAVE LET THE WIND CHILL ADVISORY EXPIRE. WIND CHILLS WILL STILL
HOVER NEAR 20 BELOW FOR MOST AREAS TODAY...SO STILL COLD. WE MAY
NEED A WIND CHILL ADVISORY ONCE AGAIN OVERNIGHT AS WINDS INCREASE
FROM THE WEST...SO WILL MONITOR THIS THREAT.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 332 AM CST TUE DEC 30 2014
COLDEST CORE OF AIRMASS IS OVER THE FCST AREA CURRENTLY. A SHORT
WAVE TROUGH MOVING SOUTHWARD NOW ALONG THE CANADIAN BORDER AND
BEHIND IT BEGINS SLOW WARMING AT THE 850 MB LEVEL LATER TODAY AND
TONIGHT. HOW MUCH WARMING WILL THERE BE AT THE SFC REMAINS A
QUESTION. TRENDED TOWARD HIGHER GUIDANCE VALUES AS GFS/NAM MOS
TEMPS TOO COLD AS MANY AREAS HAVE LIGHT OR MINIMAL SNOW COVER.
TO START THE DAY...THERE IS A BAND OF CLOUDS ALONG LEADING EDGE OF
THE SHORT WAVE...AND THIS WILL DROP SOUTHWARD THRU THE FCST
AREA..LASTING 2-3 HOURS AT ANY ONE PLACE. RAP MODEL 850 RH FIELD
SHOWS ITS PROGRESSION NICELY. BEHIND IT IT WILL CLEAR OUT AGAIN.
SO THE BALANCE OF THE DAY WILL SEE CONSIDERABLE SUN AND WINDS WILL
TURN A BIT MORE WESTERLY. WITH THIS IN MIND DID RAISE MAX TEMPS A
FEW DEGREES TO VERY NEAR YESTERDAY`S READINGS WITH ZERO TO 5 ABOVE
IN THE IMMEDIATE RRV AND SE ND/WCNTRL MN TO ZERO TO BELOW DVL
BASIN AND PARTS OF NW MN ESP AWAY FROM THICKEST FORESTS. HOURLY
TEMP AND WIND FCST INDICATE MOST AREAS OUT OF WC ADVISORY 18Z OR
SO SO WILL LEAVE THAT IN PLACE.
ALLOWED SOME FALL OFF IN TEMPS TONIGHT BUT NOT MUCH AS RISING
TEMPS EXPECTED ALONG WITH A BREEZY WEST WIND. WIND CHILLS SHOULD
BARELY DROP INTO THE ADV RANGE THIS EVENING BEFORE WARMING KICKS
IN. AREA OFFICES HOLDING OFF ON ANY NEW WIND CHILL ADV AS SO MUCH
DEPENDS ON HOW WARM IT GETS LATER TODAY AND HOW MUCH TEMP FALLS
EARLY THIS EVENING BEFORE SFC WARMING BEGINS.
SHORT WAVE WILL DIVE SOUTH THRU NW ONTARIO AND TOWARD MN ARROWHEAD
WEDNESDAY. THICKER CLOUD COVER LIKELY NORTH CENTRAL-NORTHEASTERN
MN WITH MORE OF A PARTLY CLOUDY REGIME FARTHER WEST. 850 TEMPS
DON/T FALL MUCH WEDNESDAY SO NET RESULT WILL BE WARMER AFTN HIGHS
WITH TEENS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 332 AM CST TUE DEC 30 2014
AS ADVERTISED FOR THE PAST FEW DAYS...A WEAK SHORT WAVE WILL DIVE
SOUTHEAST FROM ALBERTA AND ACROSS NORTH DAKOTA AND INTO MINNESOTA
WED NIGHT INTO THURSDAY SPREADING A BAND OF LIGHT SNOW WITH
AMOUNTS UNDER 1 INCH.
FOR FRIDAY THROUGH TUESDAY...GFS AND ECMWF HAVE COME INTO CLOSE AGREEMENT
FOR THE START OF THE PERIOD WITH A MEAN H5 TROF AXIS EXTENDING
FROM A HUDSONS BAY LOW INTO THE EASTERN GREAT LAKES WITH A REX
BLOCK ALONG THE WESTERN NOAM COAST RESULTING IN SPLIT H5 FLOW OVER
THE CONUS...A PATTERN WHICH THEN PERSISTS THROUGH THE PERIOD. THUS
WITH NORTHWEST FLOW OVER THE NORTHERN PLAINS WE STAND A GOOD
CHANCE FOR MEASURABLE SNOW /A FEW INCHES/ FROM FRIDAY EVENING
INTO SATURDAY... WITH MARKEDLY COOLER TEMPS AND ADDITIONAL
FLURRIES THROUGH THE EARLY PART OF NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1230 PM CST TUE DEC 30 2014
MOSTLY CLEAR SKIES EXPECT THIS AFTN AND TONIGHT. MAIN AVIATION ISSUE
WILL BE WINDS INCREASING OVERNIGHT...BECOMING WSW AND BREEZY
ESPECIALLY ACROSS NORTHEASTERN ND. VFR CONDITIONS EXPECTED THROUGHOUT 18Z
TAF PERIOD.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...DK
SHORT TERM...RIDDLE
LONG TERM...GUST/RIDDLE
AVIATION...SPEICHER
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1001 AM CST TUE DEC 30 2014
.UPDATE...
ISSUED AT 958 AM CST TUE DEC 30 2014
NO UPDATE PLANNED AT THIS TIME.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 332 AM CST TUE DEC 30 2014
COLDEST CORE OF AIRMASS IS OVER THE FCST AREA CURRENTLY. A SHORT
WAVE TROUGH MOVING SOUTHWARD NOW ALONG THE CANADIAN BORDER AND
BEHIND IT BEGINS SLOW WARMING AT THE 850 MB LEVEL LATER TODAY AND
TONIGHT. HOW MUCH WARMING WILL THERE BE AT THE SFC REMAINS A
QUESTION. TRENDED TOWARD HIGHER GUIDANCE VALUES AS GFS/NAM MOS
TEMPS TOO COLD AS MANY AREAS HAVE LIGHT OR MINIMAL SNOW COVER.
TO START THE DAY...THERE IS A BAND OF CLOUDS ALONG LEADING EDGE OF
THE SHORT WAVE...AND THIS WILL DROP SOUTHWARD THRU THE FCST
AREA..LASTING 2-3 HOURS AT ANY ONE PLACE. RAP MODEL 850 RH FIELD
SHOWS ITS PROGRESSION NICELY. BEHIND IT IT WILL CLEAR OUT AGAIN.
SO THE BALANCE OF THE DAY WILL SEE CONSIDERABLE SUN AND WINDS WILL
TURN A BIT MORE WESTERLY. WITH THIS IN MIND DID RAISE MAX TEMPS A
FEW DEGREES TO VERY NEAR YESTERDAY`S READINGS WITH ZERO TO 5 ABOVE
IN THE IMMEDIATE RRV AND SE ND/WCNTRL MN TO ZERO TO BELOW DVL
BASIN AND PARTS OF NW MN ESP AWAY FROM THICKEST FORESTS. HOURLY
TEMP AND WIND FCST INDICATE MOST AREAS OUT OF WC ADVISORY 18Z OR
SO SO WILL LEAVE THAT IN PLACE.
ALLOWED SOME FALL OFF IN TEMPS TONIGHT BUT NOT MUCH AS RISING
TEMPS EXPECTED ALONG WITH A BREEZY WEST WIND. WIND CHILLS SHOULD
BARELY DROP INTO THE ADV RANGE THIS EVENING BEFORE WARMING KICKS
IN. AREA OFFICES HOLDING OFF ON ANY NEW WIND CHILL ADV AS SO MUCH
DEPENDS ON HOW WARM IT GETS LATER TODAY AND HOW MUCH TEMP FALLS
EARLY THIS EVENING BEFORE SFC WARMING BEGINS.
SHORT WAVE WILL DIVE SOUTH THRU NW ONTARIO AND TOWARD MN ARROWHEAD
WEDNESDAY. THICKER CLOUD COVER LIKELY NORTH CENTRAL-NORTHEASTERN
MN WITH MORE OF A PARTLY CLOUDY REGIME FARTHER WEST. 850 TEMPS
DON/T FALL MUCH WEDNESDAY SO NET RESULT WILL BE WARMER AFTN HIGHS
WITH TEENS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 332 AM CST TUE DEC 30 2014
AS ADVERTISED FOR THE PAST FEW DAYS...A WEAK SHORT WAVE WILL DIVE
SOUTHEAST FROM ALBERTA AND ACROSS NORTH DAKOTA AND INTO MINNESOTA
WED NIGHT INTO THURSDAY SPREADING A BAND OF LIGHT SNOW WITH
AMOUNTS UNDER 1 INCH.
FOR FRIDAY THROUGH TUESDAY...GFS AND ECMWF HAVE COME INTO CLOSE AGREEMENT
FOR THE START OF THE PERIOD WITH A MEAN H5 TROF AXIS EXTENDING
FROM A HUDSONS BAY LOW INTO THE EASTERN GREAT LAKES WITH A REX
BLOCK ALONG THE WESTERN NOAM COAST RESULTING IN SPLIT H5 FLOW OVER
THE CONUS...A PATTERN WHICH THEN PERSISTS THROUGH THE PERIOD. THUS
WITH NORTHWEST FLOW OVER THE NORTHERN PLAINS WE STAND A GOOD
CHANCE FOR MEASURABLE SNOW /A FEW INCHES/ FROM FRIDAY EVENING
INTO SATURDAY... WITH MARKEDLY COOLER TEMPS AND ADDITIONAL
FLURRIES THROUGH THE EARLY PART OF NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 700 AM CST TUE DEC 30 2014
BAND OF VFR CLOUD COVER DROPPING SOUTH. AT 13Z CLOUD BAND WAS
CARRINGTON TO GRAND FORKS TO WASKISH. CLEARING BEHIND THIS CLOUD
BAND IN NE ND...BUT SCATTERED CLOUDS REMAIN IN SOUTHEASTERN
MANITOBA. TIMED CLOUD BAND SOUTHWARD THROUGH THE MORNING INTO
FARGO THEN A FEW HOURS OF SCATTERED CLOUDS THEN CLEAR. SOME CIRRUS
SPILLING SOUTH TONIGHT. WEST TO NORTHWEST WIND 10 TO 15 KTS TODAY
INCREASING 15 TO 25 KTS IN NRN VALLEY OVERNIGHT.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WIND CHILL ADVISORY UNTIL NOON CST TODAY FOR NDZ006>008-014>016-
024-026>030-038-039-049-052>054.
MN...WIND CHILL ADVISORY UNTIL NOON CST TODAY FOR MNZ001>009-013>017-
022>024-027>032-040.
&&
$$
UPDATE...DK
SHORT TERM...RIDDLE
LONG TERM...GUST/RIDDLE
AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
709 AM CST TUE DEC 30 2014
.UPDATE...
ISSUED AT 700 AM CST TUE DEC 30 2014
NO UPDATES.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 332 AM CST TUE DEC 30 2014
COLDEST CORE OF AIRMASS IS OVER THE FCST AREA CURRENTLY. A SHORT
WAVE TROUGH MOVING SOUTHWARD NOW ALONG THE CANADIAN BORDER AND
BEHIND IT BEGINS SLOW WARMING AT THE 850 MB LEVEL LATER TODAY AND
TONIGHT. HOW MUCH WARMING WILL THERE BE AT THE SFC REMAINS A
QUESTION. TRENDED TOWARD HIGHER GUIDANCE VALUES AS GFS/NAM MOS
TEMPS TOO COLD AS MANY AREAS HAVE LIGHT OR MINIMAL SNOW COVER.
TO START THE DAY...THERE IS A BAND OF CLOUDS ALONG LEADING EDGE OF
THE SHORT WAVE...AND THIS WILL DROP SOUTHWARD THRU THE FCST
AREA..LASTING 2-3 HOURS AT ANY ONE PLACE. RAP MODEL 850 RH FIELD
SHOWS ITS PROGRESSION NICELY. BEHIND IT IT WILL CLEAR OUT AGAIN.
SO THE BALANCE OF THE DAY WILL SEE CONSIDERABLE SUN AND WINDS WILL
TURN A BIT MORE WESTERLY. WITH THIS IN MIND DID RAISE MAX TEMPS A
FEW DEGREES TO VERY NEAR YESTERDAY`S READINGS WITH ZERO TO 5 ABOVE
IN THE IMMEDIATE RRV AND SE ND/WCNTRL MN TO ZERO TO BELOW DVL
BASIN AND PARTS OF NW MN ESP AWAY FROM THICKEST FORESTS. HOURLY
TEMP AND WIND FCST INDICATE MOST AREAS OUT OF WC ADVISORY 18Z OR
SO SO WILL LEAVE THAT IN PLACE.
ALLOWED SOME FALL OFF IN TEMPS TONIGHT BUT NOT MUCH AS RISING
TEMPS EXPECTED ALONG WITH A BREEZY WEST WIND. WIND CHILLS SHOULD
BARELY DROP INTO THE ADV RANGE THIS EVENING BEFORE WARMING KICKS
IN. AREA OFFICES HOLDING OFF ON ANY NEW WIND CHILL ADV AS SO MUCH
DEPENDS ON HOW WARM IT GETS LATER TODAY AND HOW MUCH TEMP FALLS
EARLY THIS EVENING BEFORE SFC WARMING BEGINS.
SHORT WAVE WILL DIVE SOUTH THRU NW ONTARIO AND TOWARD MN ARROWHEAD
WEDNESDAY. THICKER CLOUD COVER LIKELY NORTH CENTRAL-NORTHEASTERN
MN WITH MORE OF A PARTLY CLOUDY REGIME FARTHER WEST. 850 TEMPS
DONT FALL MUCH WEDNESDAY SO NET RESULT WILL BE WARMER AFTN HIGHS
WITH TEENS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 332 AM CST TUE DEC 30 2014
AS ADVERTISED FOR THE PAST FEW DAYS...A WEAK SHORT WAVE WILL DIVE
SOUTHEAST FROM ALBERTA AND ACROSS NORTH DAKOTA AND INTO MINNESOTA
WED NIGHT INTO THURSDAY SPREADING A BAND OF LIGHT SNOW WITH
AMOUNTS UNDER 1 INCH.
FOR FRIDAY THROUGH TUESDAY...GFS AND ECMWF HAVE COME INTO CLOSE AGREEMENT
FOR THE START OF THE PERIOD WITH A MEAN H5 TROF AXIS EXTENDING
FROM A HUDSONS BAY LOW INTO THE EASTERN GREAT LAKES WITH A REX
BLOCK ALONG THE WESTERN NOAM COAST RESULTING IN SPLIT H5 FLOW OVER
THE CONUS...A PATTERN WHICH THEN PERSISTS THROUGH THE PERIOD. THUS
WITH NORTHWEST FLOW OVER THE NORTHERN PLAINS WE STAND A GOOD
CHANCE FOR MEASASUREABLE SNOW /A FEW INCHES/ FROM FRIDAY EVENING
INTO SATURDAY... WITH MARKEDLY COOLER TEMPS AND ADDITIONAL
FLURRIES THROUGH THE EARLY PART OF NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 700 AM CST TUE DEC 30 2014
BAND OF VFR CLOUD COVER DROPPING SOUTH. AT 13Z CLOUD BAND WAS
CARRINGTON TO GRAND FORKS TO WASKISH. CLEARING BEHIND THIS CLOUD
BAND IN NE ND...BUT SCATTERED CLOUDS REMAIN IN SOUTHEASTERN
MANITOBA. TIMED CLOUD BAND SOUTHWARD THROUGH THE MORNING INTO
FARGO THEN A FEW HOURS OF SCATTERED CLOUDS THEN CLEAR. SOME CIRRUS
SPILLING SOUTH TONIGHT. WEST TO NORTHWEST WIND 10 TO 15 KTS TODAY
INCREASING 15 TO 25 KTS IN NRN VALLEY OVERNIGHT.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WIND CHILL ADVISORY UNTIL NOON CST TODAY FOR NDZ006>008-014>016-
024-026>030-038-039-049-052>054.
MN...WIND CHILL ADVISORY UNTIL NOON CST TODAY FOR MNZ001>009-013>017-
022>024-027>032-040.
&&
$$
UPDATE...RIDDLE
SHORT TERM...RIDDLE
LONG TERM...GUST/RIDDLE
AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
341 AM CST TUE DEC 30 2014
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 332 AM CST TUE DEC 30 2014
COLDEST CORE OF AIRMASS IS OVER THE FCST AREA CURRENTLY. A SHORT
WAVE TROUGH MOVING SOUTHWARD NOW ALONG THE CANADIAN BORDER AND
BEHIND IT BEGINS SLOW WARMING AT THE 850 MB LEVEL LATER TODAY AND
TONIGHT. HOW MUCH WARMING WILL THERE BE AT THE SFC REMAINS A
QUESTION. TRENDED TOWARD HIGHER GUIDANCE VALUES AS GFS/NAM MOS
TEMPS TOO COLD AS MANY AREAS HAVE LIGHT OR MINIMAL SNOW COVER.
TO START THE DAY...THERE IS A BAND OF CLOUDS ALONG LEADING EDGE OF
THE SHORT WAVE...AND THIS WILL DROP SOUTHWARD THRU THE FCST
AREA..LASTING 2-3 HOURS AT ANY ONE PLACE. RAP MODEL 850 RH FIELD
SHOWS ITS PROGRESSION NICELY. BEHIND IT IT WILL CLEAR OUT AGAIN.
SO THE BALANCE OF THE DAY WILL SEE CONSIDERABLE SUN AND WINDS WILL
TURN A BIT MORE WESTERLY. WITH THIS IN MIND DID RAISE MAX TEMPS A
FEW DEGREES TO VERY NEAR YESTERDAY`S READINGS WITH ZERO TO 5 ABOVE
IN THE IMMEDIATE RRV AND SE ND/WCNTRL MN TO ZERO TO BELOW DVL
BASIN AND PARTS OF NW MN ESP AWAY FROM THICKEST FORESTS. HOURLY
TEMP AND WIND FCST INDICATE MOST AREAS OUT OF WC ADVISORY 18Z OR
SO SO WILL LEAVE THAT IN PLACE.
ALLOWED SOME FALL OFF IN TEMPS TONIGHT BUT NOT MUCH AS RISING
TEMPS EXPECTED ALONG WITH A BREEZY WEST WIND. WIND CHILLS SHOULD
BARELY DROP INTO THE ADV RANGE THIS EVENING BEFORE WARMING KICKS
IN. AREA OFFICES HOLDING OFF ON ANY NEW WIND CHILL ADV AS SO MUCH
DEPENDS ON HOW WARM IT GETS LATER TODAY AND HOW MUCH TEMP FALLS
EARLY THIS EVENING BEFORE SFC WARMING BEGINS.
SHORT WAVE WILL DIVE SOUTH THRU NW ONTARIO AND TOWARD MN ARROWHEAD
WEDNESDAY. THICKER CLOUD COVER LIKELY NORTH CENTRAL-NORTHEASTERN
MN WITH MORE OF A PARTLY CLOUDY REGIME FARTHER WEST. 850 TEMPS
DONT FALL MUCH WEDNESDAY SO NET RESULT WILL BE WARMER AFTN HIGHS
WITH TEENS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 332 AM CST TUE DEC 30 2014
AS ADVERTISED FOR THE PAST FEW DAYS...A WEAK SHORT WAVE WILL DIVE
SOUTHEAST FROM ALBERTA AND ACROSS NORTH DAKOTA AND INTO MINNESOTA
WED NIGHT INTO THURSDAY SPREADING A BAND OF LIGHT SNOW WITH
AMOUNTS UNDER 1 INCH.
FOR FRIDAY THROUGH TUESDAY...GFS AND ECMWF HAVE COME INTO CLOSE AGREEMENT
FOR THE START OF THE PERIOD WITH A MEAN H5 TROF AXIS EXTENDING
FROM A HUDSONS BAY LOW INTO THE EASTERN GREAT LAKES WITH A REX
BLOCK ALONG THE WESTERN NOAM COAST RESULTING IN SPLIT H5 FLOW OVER
THE CONUS...A PATTERN WHICH THEN PERSISTS THROUGH THE PERIOD. THUS
WITH NORTHWEST FLOW OVER THE NORTHERN PLAINS WE STAND A GOOD
CHANCE FOR MEASASUREABLE SNOW /A FEW INCHES/ FROM FRIDAY EVENING
INTO SATURDAY... WITH MARKEDLY COOLER TEMPS AND ADDITIONAL
FLURRIES THROUGH THE EARLY PART OF NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1127 PM CST MON DEC 29 2014
NARROW BAND OF MAINLY SCT/BKN MID LEVEL CLOUDS ASSOCIATED WITH A
WEAK BOUNDARY WILL AFFECT THE NORTH HALF OF THE FA THROUGH 12Z.
AFTER THAT NOT SURE HOW MUCH CLOUD COVER WILL BE LEFT AS MODELS
GENERALLY WASH OUT BOUNDARY.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WIND CHILL ADVISORY UNTIL NOON CST TODAY FOR NDZ006>008-014>016-
024-026>030-038-039-049-052>054.
MN...WIND CHILL ADVISORY UNTIL NOON CST TODAY FOR MNZ001>009-013>017-
022>024-027>032-040.
&&
$$
SHORT TERM...RIDDLE
LONG TERM...GUST/RIDDLE
AVIATION...VOELKER
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
408 PM EST TUE DEC 30 2014
.SYNOPSIS...
HIGH PRESSURE AND A DRY AIRMASS WILL REMAIN IN PLACE ACROSS THE
AREA THROUGH FRIDAY. A LOW PRESSURE SYSTEM WILL LIFT NORTHEAST
ACROSS THE REGION THIS WEEKEND...BRINGING THE NEXT CHANCE FOR
PRECIPITATION.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
INCREASING LOW LEVEL LAPSE RATES ACROSS NORTHERN INDIANA
AND NORTHWEST OHIO HAVE LED TO SOME SCATTERED SNOW SHOWER/FLURRY
DEVELOPMENT THIS AFTERNOON. THIS MAY BECOME A BIT MORE WIDESPREAD
ACROSS OUR NORTHWEST OVER THE NEXT HOUR OR SO BUT WOULD EXPECT TO
SEE A DOWNTURN IN COVERAGE THROUGH THE EVENING HOURS AS THE LOW
LEVEL LAPSE RATES BEGIN TO DECREASE AGAIN. WILL THEREFORE JUST
INCLUDE A CHANCE OF A FLURRY ACROSS PARTS OF OUR NORTHWEST THROUGH
MID EVENING. THE CLOUDS ARE ALSO LOOKING FAIRLY DIURNAL ON THE
VISIBLE SATELLITE IMAGERY SO WOULD EXPECT TO SEE SOME DISSIPATION
IN THE CLOUDS THROUGH THE EVENING HOURS TOO. WILL TREND TOWARD A
PARTLY CLOUDY SKY NORTH TO MOSTLY CLEAR IN THE SOUTH FOR LATER
TONIGHT. EXPECT OVERNIGHT LOWS DOWN INTO THE TEENS ACROSS THE
AREA.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
AN ELONGATED AXIS OF SURFACE HIGH PRESSURE WILL REMAIN STRETCHED
ACROSS THE OHIO AND TENNESSEE VALLEYS WEDNESDAY INTO THURSDAY.
WITH A DRY AIRMASS IN PLACE...EXPECT MAINLY CLEAR SKIES THROUGH
MUCH OF THE SHORT TERM PERIOD. WEAK LOW LEVEL CAA WILL CONTINUE
INTO WEDNESDAY AND ALLOWING FOR MIXING UP TO ABOUT 900 MB ONLY
YIELDS HIGHS RANGING FROM THE LOWER 20S NORTH TO MID/UPPER 20S
SOUTH. LOW LEVEL FLOW WILL BEGIN TO SLOWLY BACK WEDNESDAY NIGHT
INTO THURSDAY...LEADING TO SOME WEAK DEVELOPING WAA. EXPECT HIGHS
ON THURSDAY RANGING FROM THE UPPER 20S NORTH TO LOW/MID 30S SOUTH.
THIS WILL ALSO LEAD TO A GRADUAL INCREASING IN CLOUDS FROM THE
SOUTH THROUGH THURSDAY NIGHT.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
THE CLOSED LOW IN PLACE ACROSS THE SOUTHWEST CONUS EARLIER IN THE
WEEK WILL BE MOVING ACROSS THE FOUR CORNERS REGION TOWARD THE PLAINS
ON FRIDAY. MODEL RUNS OVER THE PAST COUPLE DAYS HAVE BEEN RATHER
CONSISTENT WITH THIS MOVEMENT OF THE UPPER LOW...AS WELL AS
DEVELOPING A SOUTHERLY FLOW OUT OF THE GULF OF MEXICO AT THE SAME
TIME. MOISTURE SHOULD REMAIN LIMITED ENOUGH FRIDAY AND FRIDAY NIGHT
ACROSS THE AREA...AND CONFLUENT FLOW ALOFT WILL BE IN PLACE...SO
ONLY A SLIGHT CHANCE OF RAIN AND SNOW IS INCLUDED IN THE
FORECAST...MAINLY OVER THE SOUTHERN COUNTIES OF THE AREA.
INCONSISTENCIES ACROSS THE MODELS HAVE BEEN MUCH MORE ABUNDANT WITH
THE HANDLING OF THE UPPER LOW AS IT EMERGES INTO THE PLAINS STATES
ON SATURDAY. AFTER SUGGESTING YESTERDAY THAT PHASING OF NORTHERN AND
SOUTHERN STREAM ENERGY MAY NOT HAPPEN...RUNS LAST NIGHT AND TODAY
ARE SUGGESTING THIS PHASING MAY INDEED OCCUR. THE 12Z RUNS HAVE ALL
PRETTY MUCH COME IN SUPPORTING PHASING AND A SURFACE LOW TRACK INTO
THE OHIO VALLEY AND GREAT LAKES FROM SATURDAY AFTERNOON THROUGH
SUNDAY. THIS SOLUTION WOULD SUPPORT THE DEVELOPMENT OF A WINTRY MIX
OF PRECIPITATION LATE FRIDAY NIGHT AND SATURDAY MORNING ACROSS THE
AREA...BEFORE CHANGING OVER TO RAIN BY LATER SATURDAY AFTERNOON.
BUFKIT SOUNDINGS INDICATE ENOUGH COLD AIR SHOULD INITIALLY BE IN
PLACE AT THE SURFACE FOR SOME FREEZING RAIN TO DEVELOP LATE FRIDAY
NIGHT AND SATURDAY MORNING WITH THIS PARTICULAR STORM TRACK. ONLY A
MIX OF RAIN AND SNOW WILL BE INCLUDED IN THIS FORECAST PACKAGE FOR
NOW...PENDING MORE AGREEMENT ON THE SYSTEM TRACK FROM FUTURE MODEL
RUNS.
RAIN MAY CHANGE BACK TO SOME SNOW AS PRECIPITATION PULLS OUT OF THE
AREA SUNDAY...WITH TEMPERATURES COOLING BACK BELOW NORMAL. THE 12Z
MODELS ARE TRYING TO RESOLVE A COUPLE OF DISTURBANCES ROTATING
THROUGH CYCLONIC FLOW EARLY NEXT WEEK. THESE IMPULSES COULD BRING
CHANCES FOR LIGHT SNOW TO THE AREA MONDAY AND TUESDAY.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
VFR SKC OR JUST FEW CLOUDS THROUGH 21-00Z...AND THEN BOTH RAP AND
NAM PICK UP THE MVFR CIGS OVER INDIANA FAIRLY WELL AT THIS
TIME...SO CONTINUING WITH THE PREVIOUS FORECAST OF MVFR CIGS IN
THE 00Z-08Z TIMEFRAME...THOUGH THIS IS SLIGHTLY ON THE PESSIMISTIC
SIDE AS ADVECTION OF MOISTURE OFF LAKE MI STOPPING OVERNIGHT AS THE
SFC HIGH BUILDS IN AND THE MOISTURE FLOW CUTS OFF.
SCATTERING/LIFING OF THE MVFR CLOUDS MAY OCCUR EARLIER. SOME
POTENTIAL AT KDAY/KCMH/KLCK FOR MVFR CIGS TO DROP BELOW THE 2K FT
FUEL ALTERNATE CRITERIA THRESHOLD IN THE 02Z-08Z TIMEFRAME.
AFTER THIS LL MOISTURE PUSHES EAST...FLOW BACKS TO THE SW WITH
SLIGHTLY INCREASED WINDS.
OUTLOOK...MVFR CEILINGS AND VISIBILITIES POSSIBLE ON SATURDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...JGL
NEAR TERM...JGL
SHORT TERM...JGL
LONG TERM...SHOBE2
AVIATION...JDR
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1256 PM EST TUE DEC 30 2014
.SYNOPSIS...
HIGH PRESSURE WILL KEEP A DRY CONIDITIONS OVER THE OHIO VALLEY
THROUGH FRIDAY. ON FRIDAY NIGHT...LOW PRESSURE FROM THE SOUTHERN
PLAINS WILL TRACK TOWARD THE LOWER OHIO VALLEY AT THE SAME TIME A
LOW PRESSURE WILL TRACK TOWARD THE GREAT LAKES FROM THE NORTHERN
PLAINS. THE COMBINATION OF THESE TWO SYSTEMS WILL BRING
PRECIPITATION TO THE REGION FRIDAY NIGHT INTO THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CONTINUED SUN...BUT WITH SOME LAKE EFFECT CLOUDS TO AFFECT THE
NORTHERN FCST AREA AS THE AFTERNOON PROGRESSES. WITH THIS AMOUNT
OF SUN...TEMPS IN ESPECIALLY THE SOUTHERN FCST AREA CLIMBING A BIT
MORE THAN ANTICIPATED SO HAVE RAISED HIGHS SLIGHTLY HERE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
HIGH PRESSURE WILL DIVE SOUTHWARD FROM THE NORTHERN PLAINS TODAY
TO OKLAHOMA WEDNESDAY AND THEN SETTLE OVER THE GULF STATES
THURSDAY. THE HIGH WILL THEN LIFT NORTHWARD THROUGH THE TENNESSEE
VALLEY TO THE OHIO VALLEY BY FRIDAY EVENING. GENERALLY DRY
CONDITIONS AND MOSTLY CLEAR SKIES WILL OCCUR FOR THE REGION
THROUGH THIS TIME.
THE ARCTIC AIR WILL BE AT ITS HEIGHT OVER THE REGION TONIGHT
THROUGH WEDNESDAY NIGHT WITH LOWS IN THE TEENS AND HIGHS IN THE
20S. THE AIRMASS WILL BEGIN TO MODERATE AFTER THIS TIME WITH A
GRADUAL RISE IN BOTH DAYTIME HIGHS AND NIGHTTIME LOWS FOR EACH
PERIOD.
THE NEXT SHOT OF PRECIPITATION WILL BEGIN LATE FRIDAY NIGHT AS A
WARM FRONT PASSES OVER THE REGION ASSOCIATED WITH LOW PRESSURE
EJECTING NORTHEAST FROM THE WESTERN GULF.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
THE PERIOD BEGINS WITH SURFACE HIGH PRESSURE ACROSS THE LOWER
MISSISSIPPI VALLEY THURSDAY AND THURSDAY NIGHT. THIS FEATURE WILL
KEEP DRY CONDITIONS ACROSS THE AREA WITH BELOW NORMAL TEMPERATURES.
THE MAIN QUESTION FOR THIS FORECAST CONTINUES TO BE THE EVOLUTION OF
THE SOUTHWEST CONUS UPPER LOW. MODEL RUNS FROM THE PAST COUPLE DAYS
HAVE GENERALLY SLOWED THE EJECTION OF THIS LOW...WITH THE FEATURE
NOT REALLY LEAVING THE FOUR CORNERS ON THE 12Z RUNS UNTIL FRIDAY
NIGHT. SOME MOISTURE IS SHOWN RETURNING FRIDAY FROM THE GULF TOWARD
THE OHIO VALLEY WELL AHEAD OF THE UPPER LOW...THOUGH CONFLUENT FLOW
ALOFT SHOULD COUNTERACT THE DEVELOPMENT OF PRECIPITATION ACROSS THE
AREA. ENOUGH LIFT AND MOISTURE MAY BE IN PLACE BY FRIDAY NIGHT TO
PRODUCE SOME RAIN AND SNOW...ESPECIALLY ACROSS THE SOUTHERN PORTION
OF THE AREA. THAT CHANCE WILL CONTINUE INTO SATURDAY...THOUGH THE
12Z ECMWF/PARALLEL GFS ARE INDICATING THE BEST MOISTURE AND SURFACE
LOW DEVELOPMENT WILL REMAIN SOUTH OF THE AREA. THE 12Z GFS AND GFS
ENSEMBLE STILL SHOW THIS SYSTEM PROPAGATING TOWARD THE OHIO
VALLEY...THOUGH THE STRENGTH OF THE UPPER LOW IN PLACE OVER HUDSON
BAY MAY JUST BE ENOUGH TO BRUSH THIS SYSTEM MORE EAST ALONG THE
LINES OF THE ECMWF/PARALLEL GFS. THIS SOLUTION WOULD STILL KEEP
CHANCES OF RAIN AND SNOW ACROSS THE AREA THROUGH SUNDAY...THOUGH
MORE FOCUSED ON THE THE SOUTHERN COUNTIES.
ALL OF THE MODELS TEND TO PULL PRECIPITATION OUT OF THE AREA BY
SUNDAY NIGHT...WITH GENERALLY DRY CONDITIONS IN PLACE MONDAY.
TEMPERATURES SHOULD BE NEAR TO SOMEWHAT BELOW NORMAL AT THE END OF
THE PERIOD.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
VFR SKC OR JUST FEW CLOUDS THROUGH 21-00Z...AND THEN BOTH RAP AND
NAM PICK UP THE MVFR CIGS OVER INDIANA FAIRLY WELL AT THIS
TIME...SO CONTINUING WITH THE PREVIOUS FORECAST OF MVFR CIGS IN
THE 00Z-08Z TIMEFRAME...THOUGH THIS IS SLIGHTLY ON THE PESSIMISTIC
SIDE AS ADVECTION OF MOISTURE OFF LAKE MI STOPPING OVERNIGHT AS THE
SFC HIGH BUILDS IN AND THE MOISTURE FLOW CUTS OFF.
SCATTERING/LIFING OF THE MVFR CLOUDS MAY OCCUR EARLIER. SOME
POTENTIAL AT KDAY/KCMH/KLCK FOR MVFR CIGS TO DROP BELOW THE 2K FT
FUEL ALTERNATE CRITERIA THRESHOLD IN THE 02Z-08Z TIMEFRAME.
AFTER THIS LL MOISTURE PUSHES EAST...FLOW BACKS TO THE SW WITH
SLIGHTLY INCREASED WINDS.
OUTLOOK...MVFR CEILINGS AND VISIBILITIES POSSIBLE ON SATURDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...JDR
NEAR TERM...JDR
SHORT TERM...FRANKS
LONG TERM...SHOBE2
AVIATION...JDR
AREA FORECAST DISCUSSION
NWS TULSA OK
1126 PM CST MON DEC 29 2014
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
VFR CIGS ALL SITES WITH LAYERED CLOUDS THROUGHOUT THE PERIOD. CIGS
BECOMING MVFR NERN OK SITES FOLLOWING COLD FRONTAL SURGE LATER
TONIGHT. CIGS PROBABLY HANG AROUND ON TUESDAY LONGER THAN
INDICATED IN MODEL FIELDS. NORTHEASTERLY WIND WILL BACK TO THE
NORTH NORTHEAST AND INCREASE WITH FRONTAL PASSAGE.
&&
.PREV DISCUSSION... /ISSUED 904 PM CST MON DEC 29 2014/
..UPDATE...
DISCUSSION...
RADAR ECHOES ARE LEAVING THE FORECAST AREA...SO WILL DROP MENTION
OF FLURRIES FOR THE REMAINDER OF THE OVERNIGHT PERIOD. 00Z
NAM...01Z HRRR AND 02Z RAP ALL APPEAR DRY FOR THE REST OF THE
NIGHT. LFM IS MISSING...ALONG WITH BAROTROPIC AND SHIP PAPA DATA.
..HAVING A RIP VAN WINKLE MOMENT...
WILL UPDATE TO TAKE OUT FLURRIES AND SPRINKLES.
APPEARS THE COLD SURGE IS STILL IN KANSAS...FROM JUST SOUTH OF MKC
TO NORTH OF ICT TO NEAR AMA...BASED MAINLY ON LOCATION OF
STRONGEST WINDS AND GUSTINESS. PROGRESS HAS BEEN SLOW...BUT ON
TARGET FOR TUESDAY MORNING.
NO CHANGE TO MINIMUM TEMPS.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
SHORT TERM...02
AVIATION...69
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
333 AM EST TUE DEC 30 2014
.SYNOPSIS...
A HIGHLY AMPLIFIED PATTERN OVER NORTH AMERICA WITH A STRONG RIDGE
OVER THE PACIFIC NORTHWEST AND A TROUGH OVER THE NORTHEAST WILL
PRODUCE TWO COLD SURGES. THE FIRST SHOULD PRODUCE COLD WEATHER
TROUGH NEW YEARS. A SOUTHERN STREAM STORM COULD BRING A WINTRY MIX
AND/OR RAIN TO THE REGION OVER THE WEEKEND AHEAD OF THE FORECAST
SECOND SURGE OF COLD CONTINENTAL AIR.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
SATELLITE IMAGERY CONTINUES TO SHOW TWO DISTINCT CLOUDS
SYSTEMS...HIGH CLOUDS PASSING TO OUR SOUTH AND LOW CLOUDS NEAR THE
NY BORDER.
HRRR SHOWS NO SIGNIFICANT SNOW AREAS OVERNIGHT...HOWEVER LATESET
RADAR IMAGERSY SHOWS BAND OF FLURRIES/LIGHT SNOW SHOWERS
MOVING SE ACROSS PARTS OF THE CENTRAL MTNS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM WEDNESDAY/...
THE HRRR ONLY GETS US TO LATE MORNING AND IT SHOWS...AT BEST SOME
FLURRIES IN SPOTS ALONG NY BORDER IN MORNING.
HIGH PRESSURE TO OUR WEST CONTINUES TO BUILD INTO THE REGION FROM
THE WEST TUESDAY. IN THIS NORTH-NORTHWEST FLOW OUR 850 MB TEMPS
FALL 2 TO 4 MORE DEGREES DURING THE DAY GETTING TO ABOUT -1SD
BELOW NORMAL BY EVENING. A COLDER THAN NORMAL DAY IS ON TAP.
THE HIGH SLIDES TO OUR SOUTH AND WEST INTO WEDNESDAY AND OUR 850
MB TEMPS BOTTOM OUT IN THE -13 TO -18C RANGE. THIS IMPLIES BETTER
CHANCE OF SOME LAKE ENHANCED SNOWS IN NORTHWESTERN AND WESTERN
MOUNTAINS. THE SNOW IN NW PA AND SW NY PEAKS IN THE SREF AFTER 00
TO 03 UTC WEDNESDAY AND BEGINS TO DIMINISH WEDNESDAY EVENING.
TRIED TO SHOW SOME SNOW UP IN THE NW AREAS BUT KEPT AMOUNT ON THE
LOW SIDE. BLENDED LARGE SCALE MODELS WITH 21Z SREF TO REFINE THE
AREA OF POPS AND QPF. QPF AMOUNTS WERE OF COURSE LOW.
CLEARLY WEDNESDAY SHOULD BE ABOUT THE COLDEST DAY OF THE WINTER
TO DATE WITH THE -16C CONTOUR DRAPED OVER CENTRAL PA AND AT LEAST
-1SD BELOW NORMAL TEMPERATURES. THAT IS 5 TO 10F BELOW NORMAL.
THE COLD AT LEAST WILL CONTINUE INTO NEW YEARS DAY (SEE BELOW) AS
THE HIGH LUMBERS BY TO OUR SOUTH.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
STRONG HIGH PRESSURE OVER THE CENTRAL U.S. THIS MIDWEEK WILL
WEAKEN AND DRIFT TOWARD THE CAROLINAS BY FRIDAY AS A WEAK WAVE
SLIDES QUICKLY ACROSS THE GREAT LAKES. THIS WILL BRING AN
EXTENDED PERIOD OF FAIR BUT COOLER THAN NORMAL WEATHER TO THE
FORECAST AREA. SOME SNOW SHOWERS MAY IMPACT THE NW MTNS...BUT
MOST OF THE SNOW SHOWER ACTIVITY WILL REMAIN NORTH OF THE PA
BORDER. BREEZY CONDITIONS WED NIGHT INTO THU IN FAST FLOW WILL
RESULT IN SINGLE DIGIT WIND CHILLS OVER NORTHERN AND WESTERN PARTS
OF THE CWA AS WE RING IN THE NEW YEAR.
GEFS AND OTHER LONG RANGE GUIDANCE SHOW THE FIRST NOTABLE STORM
OF 2015 DEVELOPING FOR NEXT WEEKEND. TIMING/STORM TRACK ISSUES
REMAIN WITH MUCH UNCERTAINTY IN EVOLUTION OF THIS SYSTEM...BUT
GUIDANCE IMPLIES A POTENTIAL MIXED PRECIPITATION EVENT FROM
GENERALLY SAT AFT THROUGH FIRST HALF OF SUNDAY. GFS CONTINUES TO
BRINGS A LOW UP THE OHIO VALLEY TO OUR WEST...PUSHING A SHOT OF
MILDER AIR BACK INTO THE STATE WITH RAIN LIKELY BECOMING THE MOST
DOMINANT PRECIPITATION TYPE /WITH FREEZING PRECIP POSS AT ONSET/.
IN CONTRAST...THE OPERATIONAL ECMWF REMAINING FIRM ON BRINGING
THE SURFACE LOW SOUTH AND EAST OF PA WHICH WOULD RESULT IN COLDER
AIR AND A MORE MIXED BAG OF PRECIPITATION TYPES AND PERHAPS SNOW
IN NORTHERN AND SOME CENTRAL AREAS. THE EC MEAN IS A BIT MORE
AGGRESSIVE DEVELOPING THE LOW...POTENTIALLY MAKING THE OPERATIONAL
RUN AN OUTLIER. FOR NOW...DIDN/T MAKE ANY LARGE CHANGES TO
FORECAST OVER THE WEEKEND AND HELD ON TO THE POTENTIAL FOR A MIX
OF WINTRY PRECIP - ESP ACROSS CENTRAL AND NORTHERN PA...AND LEANED
MORE TOWARD RAIN IN THE LOWER SUSQ.
QUICK SHOT OF COLDER AIR TO START NEXT WEEK...WITH CHANCE FOR
ANOTHER LOW SLIDING EASTWARD FROM THE GREAT LAKES INTO NEW ENGLAND
MIDWEEK WITH CHANCE OF SNOW FOR PA.
&&
.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
MVFR CIGS WILL LIKELY REMAIN IN PLACE AT BFD INTO TUESDAY WITH
NORTHWESTERLY WINDS AND A CHILLY...SHALLOW AIR MASS. CONTINUED
NORTHWESTERLY FLOW WILL MAKE A FEW FLURRIES AT BFD...BUT THE REST
OF THE TERMINALS WILL REMAIN DRY AND ONLY JST MAY SEE MVFR CIGS
OVERNIGHT. CLOUDS MAY LOWER AT IPT/UNV AS THE LOW CLOUD DECK
ASSOCIATED WITH THE COLDER AIR SLIDING DOWN FROM THE NORTH MOVES
SOUTHWARD. BUT...WILL KEEP IT AS VFR THRU THE TAF PERIOD FOR THE
TIME BEING.
HIGH PRESSURE CENTERED OVER THE FRONT RANGE OF THE ROCKIES AND THE
GREAT PLAINS WILL STRETCH FAR TO THE EAST AND GRADUALLY SINK
SOUTHWARD. A BRIEF SHOT OF COLDER AIR WITHIN A FEW HOURS OF 12Z
WED MAY CREATE A BROADER AREA OF SHSN/SQ. BUT THE REDUCTIONS IN
VIS/CIG SHOULD BE LIMITED TO BFD...AND NOT EVEN JST. THE WAVE
ALOFT WILL BE ACCOMPANIED BY VERY LITTLE MOISTURE. WINDS COULD
BECOME GUSTY...THOUGH.
OUTLOOK...
WED-FRI...VFR.
SAT...MVFR/IFR POSS IN WINTRY PRECIP.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...GRUMM/GARTNER
NEAR TERM...GRUMM/GARTNER
SHORT TERM...GRUMM
LONG TERM...RXR
AVIATION...DANGELO/CERU/GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
217 AM EST TUE DEC 30 2014
.SYNOPSIS...
A HIGHLY AMPLIFIED PATTERN OVER NORTH AMERICA WITH A STRONG RIDGE
OVER THE PACIFIC NORTHWEST AND A TROUGH OVER THE NORTHEAST WILL
PRODUCE TWO COLD SURGES. THE FIRST SHOULD PRODUCE COLD WEATHER
TROUGH NEW YEARS. A SOUTHERN STREAM STORM COULD BRING A WINTRY MIX
AND/OR RAIN TO THE REGION OVER THE WEEKEND AHEAD OF THE FORECAST
SECOND SURGE OF COLD CONTINENTAL AIR.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
SATELLITE IMAGERY CONTINUES TO SHOW TWO DISTINCT CLOUDS
SYSTEMS...HIGH CLOUDS PASSING TO OUR SOUTH AND LOW CLOUDS NEAR THE
NY BORDER. HRRR SUGGESTS OUR FORECASTS IN SOUTH/CENTRAL ARE TOO
CLOUDY.
HRRR ALSO SHOWS NO SIGNIFICANT SNOW AREAS OVERNIGHT IN NORTHWEST.
THE WEAK NORTHWEST FLOW OUT OF THE HIGH CENTERED OVER THE TN
VALLEY DOES NOT CAUSE THE MODEL TO GENERATE ANY LAKE ENHANCED
SNOWS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM WEDNESDAY/...
THE HRRR ONLY GETS US TO LATE MORNING AND IT SHOWS...AT BEST SOME
FLURRIES IN SPOTS ALONG NY BORDER IN MORNING.
HIGH PRESSURE TO OUR WEST CONTINUES TO BUILD INTO THE REGION FROM
THE WEST TUESDAY. IN THIS NORTH-NORTHWEST FLOW OUR 850 MB TEMPS
FALL 2 TO 4 MORE DEGREES DURING THE DAY GETTING TO ABOUT -1SD
BELOW NORMAL BY EVENING. A COLDER THAN NORMAL DAY IS ON TAP.
THE HIGH SLIDES TO OUR SOUTH AND WEST INTO WEDNESDAY AND OUR 850
MB TEMPS BOTTOM OUT IN THE -13 TO -18C RANGE. THIS IMPLIES BETTER
CHANCE OF SOME LAKE ENHANCED SNOWS IN NORTHWESTERN AND WESTERN
MOUNTAINS. THE SNOW IN NW PA AND SW NY PEAKS IN THE SREF AFTER 00
TO 03 UTC WEDNESDAY AND BEGINS TO DIMINISH WEDNESDAY EVENING.
TRIED TO SHOW SOME SNOW UP IN THE NW AREAS BUT KEPT AMOUNT ON THE
LOW SIDE. BLENDED LARGE SCALE MODELS WITH 21Z SREF TO REFINE THE
AREA OF POPS AND QPF. QPF AMOUNTS WERE OF COURSE LOW.
CLEARLY WEDNESDAY SHOULD BE ABOUT THE COLDEST DAY OF THE WINTER
TO DATE WITH THE -16C CONTOUR DRAPED OVER CENTRAL PA AND AT LEAST
-1SD BELOW NORMAL TEMPERATURES. THAT IS 5 TO 10F BELOW NORMAL.
THE COLD AT LEAST WILL CONTINUE INTO NEW YEARS DAY (SEE BELOW) AS
THE HIGH LUMBERS BY TO OUR SOUTH.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
STRONG HIGH PRESSURE OVER THE CENTRAL U.S. THIS MIDWEEK WILL
WEAKEN AND DRIFT TOWARD THE CAROLINAS BY FRIDAY AS A WEAK WAVE
SLIDES QUICKLY ACROSS THE GREAT LAKES. THIS WILL BRING AN
EXTENDED PERIOD OF FAIR BUT COOLER THAN NORMAL WEATHER TO THE
FORECAST AREA. SOME SNOW SHOWERS MAY IMPACT THE NW MTNS...BUT
MOST OF THE SNOW SHOWER ACTIVITY WILL REMAIN NORTH OF THE PA
BORDER. BREEZY CONDITIONS WED NIGHT INTO THU IN FAST FLOW WILL
RESULT IN SINGLE DIGIT WIND CHILLS OVER NORTHERN AND WESTERN PARTS
OF THE CWA AS WE RING IN THE NEW YEAR.
GEFS AND OTHER LONG RANGE GUIDANCE SHOW THE FIRST NOTABLE STORM
OF 2015 DEVELOPING FOR NEXT WEEKEND. TIMING/STORM TRACK ISSUES
REMAIN WITH MUCH UNCERTAINTY IN EVOLUTION OF THIS SYSTEM...BUT
GUIDANCE IMPLIES A POTENTIAL MIXED PRECIPITATION EVENT FROM
GENERALLY SAT AFT THROUGH FIRST HALF OF SUNDAY. GFS CONTINUES TO
BRINGS A LOW UP THE OHIO VALLEY TO OUR WEST...PUSHING A SHOT OF
MILDER AIR BACK INTO THE STATE WITH RAIN LIKELY BECOMING THE MOST
DOMINANT PRECIPITATION TYPE /WITH FREEZING PRECIP POSS AT ONSET/.
IN CONTRAST...THE OPERATIONAL ECMWF REMAINING FIRM ON BRINGING
THE SURFACE LOW SOUTH AND EAST OF PA WHICH WOULD RESULT IN COLDER
AIR AND A MORE MIXED BAG OF PRECIPITATION TYPES AND PERHAPS SNOW
IN NORTHERN AND SOME CENTRAL AREAS. THE EC MEAN IS A BIT MORE
AGGRESSIVE DEVELOPING THE LOW...POTENTIALLY MAKING THE OPERATIONAL
RUN AN OUTLIER. FOR NOW...DIDN/T MAKE ANY LARGE CHANGES TO
FORECAST OVER THE WEEKEND AND HELD ON TO THE POTENTIAL FOR A MIX
OF WINTRY PRECIP - ESP ACROSS CENTRAL AND NORTHERN PA...AND LEANED
MORE TOWARD RAIN IN THE LOWER SUSQ.
QUICK SHOT OF COLDER AIR TO START NEXT WEEK...WITH CHANCE FOR
ANOTHER LOW SLIDING EASTWARD FROM THE GREAT LAKES INTO NEW ENGLAND
MIDWEEK WITH CHANCE OF SNOW FOR PA.
&&
.AVIATION /07Z TUESDAY THROUGH SATURDAY/...
MVFR CIGS WILL LIKELY REMAIN IN PLACE AT BFD INTO TUESDAY WITH
NORTHWESTERLY WINDS AND A CHILLY...SHALLOW AIR MASS. CONTINUED
NORTHWESTERLY FLOW WILL MAKE A FEW FLURRIES AT BFD...BUT THE REST
OF THE TERMINALS WILL REMAIN DRY AND ONLY JST MAY SEE MVFR CIGS
OVERNIGHT. CLOUDS MAY LOWER AT IPT/UNV AS THE LOW CLOUD DECK
ASSOCIATED WITH THE COLDER AIR SLIDING DOWN FROM THE NORTH MOVES
SOUTHWARD. BUT...WILL KEEP IT AS VFR THRU THE TAF PERIOD FOR THE
TIME BEING.
HIGH PRESSURE CENTERED OVER THE FRONT RANGE OF THE ROCKIES AND THE
GREAT PLAINS WILL STRETCH FAR TO THE EAST AND GRADUALLY SINK
SOUTHWARD. A BRIEF SHOT OF COLDER AIR WITHIN A FEW HOURS OF 12Z
WED MAY CREATE A BROADER AREA OF SHSN/SQ. BUT THE REDUCTIONS IN
VIS/CIG SHOULD BE LIMITED TO BFD...AND NOT EVEN JST. THE WAVE
ALOFT WILL BE ACCOMPANIED BY VERY LITTLE MOISTURE. WINDS COULD
BECOME GUSTY...THOUGH.
OUTLOOK...
WED-FRI...VFR.
SAT...MVFR/IFR POSS IN WINTRY PRECIP.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...GRUMM/GARTNER
NEAR TERM...GRUMM/GARTNER
SHORT TERM...GRUMM
LONG TERM...RXR
AVIATION...DANGELO/CERU/GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
109 AM EST TUE DEC 30 2014
.SYNOPSIS...
A HIGHLY AMPLIFIED PATTERN OVER NORTH AMERICA WITH A STRONG RIDGE
OVER THE PACIFIC NORTHWEST AND A TROUGH OVER THE NORTHEAST WILL
PRODUCE TWO COLD SURGES. THE FIRST SHOULD PRODUCE COLD WEATHER
TROUGH NEW YEARS. A SOUTHERN STREAM STORM COULD BRING A WINTRY MIX
AND/OR RAIN TO THE REGION OVER THE WEEKEND AHEAD OF THE FORECAST
SECOND SURGE OF COLD CONTINENTAL AIR.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
SATELLITE IMAGERY CONTINUES TO SHOW TWO DISTINCT CLOUDS
SYSTEMS...HIGH CLOUDS PASSING TO OUR SOUTH AND LOW CLOUDS NEAR THE
NY BORDER. HRRR SUGGESTS OUR FORECASTS IN SOUTH/CENTRAL ARE TOO
CLOUDY.
HRRR ALSO SHOWS NO SIGNIFICANT SNOW AREAS OVERNIGHT IN NORTHWEST.
THE WEAK NORTHWEST FLOW OUT OF THE HIGH CENTERED OVER THE TN
VALLEY DOES NOT CAUSE THE MODEL TO GENERATE ANY LAKE ENHANCED
SNOWS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM WEDNESDAY/...
THE HRRR ONLY GETS US TO LATE MORNING AND IT SHOWS...AT BEST SOME
FLURRIES IN SPOTS ALONG NY BORDER IN MORNING.
HIGH PRESSURE TO OUR WEST CONTINUES TO BUILD INTO THE REGION FROM
THE WEST TUESDAY. IN THIS NORTH-NORTHWEST FLOW OUR 850 MB TEMPS
FALL 2 TO 4 MORE DEGREES DURING THE DAY GETTING TO ABOUT -1SD
BELOW NORMAL BY EVENING. A COLDER THAN NORMAL DAY IS ON TAP.
THE HIGH SLIDES TO OUR SOUTH AND WEST INTO WEDNESDAY AND OUR 850
MB TEMPS BOTTOM OUT IN THE -13 TO -18C RANGE. THIS IMPLIES BETTER
CHANCE OF SOME LAKE ENHANCED SNOWS IN NORTHWESTERN AND WESTERN
MOUNTAINS. THE SNOW IN NW PA AND SW NY PEAKS IN THE SREF AFTER 00
TO 03 UTC WEDNESDAY AND BEGINS TO DIMINISH WEDNESDAY EVENING.
TRIED TO SHOW SOME SNOW UP IN THE NW AREAS BUT KEPT AMOUNT ON THE
LOW SIDE. BLENDED LARGE SCALE MODELS WITH 21Z SREF TO REFINE THE
AREA OF POPS AND QPF. QPF AMOUNTS WERE OF COURSE LOW.
CLEARLY WEDNESDAY SHOULD BE ABOUT THE COLDEST DAY OF THE WINTER
TO DATE WITH THE -16C CONTOUR DRAPED OVER CENTRAL PA AND AT LEAST
-1SD BELOW NORMAL TEMPERATURES. THAT IS 5 TO 10F BELOW NORMAL.
THE COLD AT LEAST WILL CONTINUE INTO NEW YEARS DAY (SEE BELOW) AS
THE HIGH LUMBERS BY TO OUR SOUTH.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
STRONG HIGH PRESSURE OVER THE CENTRAL U.S. THIS MIDWEEK WILL
WEAKEN AND DRIFT TOWARD THE CAROLINAS BY FRIDAY AS A WEAK WAVE
SLIDES QUICKLY ACROSS THE GREAT LAKES. THIS WILL BRING AN
EXTENDED PERIOD OF FAIR BUT COOLER THAN NORMAL WEATHER TO THE
FORECAST AREA. SOME SNOW SHOWERS MAY IMPACT THE NW MTNS...BUT
MOST OF THE SNOW SHOWER ACTIVITY WILL REMAIN NORTH OF THE PA
BORDER. BREEZY CONDITIONS WED NIGHT INTO THU IN FAST FLOW WILL
RESULT IN SINGLE DIGIT WIND CHILLS OVER NORTHERN AND WESTERN PARTS
OF THE CWA AS WE RING IN THE NEW YEAR.
GEFS AND OTHER LONG RANGE GUIDANCE SHOW THE FIRST NOTABLE STORM
OF 2015 DEVELOPING FOR NEXT WEEKEND. TIMING/STORM TRACK ISSUES
REMAIN WITH MUCH UNCERTAINTY IN EVOLUTION OF THIS SYSTEM...BUT
GUIDANCE IMPLIES A POTENTIAL MIXED PRECIPITATION EVENT FROM
GENERALLY SAT AFT THROUGH FIRST HALF OF SUNDAY. GFS CONTINUES TO
BRINGS A LOW UP THE OHIO VALLEY TO OUR WEST...PUSHING A SHOT OF
MILDER AIR BACK INTO THE STATE WITH RAIN LIKELY BECOMING THE MOST
DOMINANT PRECIPITATION TYPE /WITH FREEZING PRECIP POSS AT ONSET/.
IN CONTRAST...THE OPERATIONAL ECMWF REMAINING FIRM ON BRINGING
THE SURFACE LOW SOUTH AND EAST OF PA WHICH WOULD RESULT IN COLDER
AIR AND A MORE MIXED BAG OF PRECIPITATION TYPES AND PERHAPS SNOW
IN NORTHERN AND SOME CENTRAL AREAS. THE EC MEAN IS A BIT MORE
AGGRESSIVE DEVELOPING THE LOW...POTENTIALLY MAKING THE OPERATIONAL
RUN AN OUTLIER. FOR NOW...DIDN/T MAKE ANY LARGE CHANGES TO
FORECAST OVER THE WEEKEND AND HELD ON TO THE POTENTIAL FOR A MIX
OF WINTRY PRECIP - ESP ACROSS CENTRAL AND NORTHERN PA...AND LEANED
MORE TOWARD RAIN IN THE LOWER SUSQ.
QUICK SHOT OF COLDER AIR TO START NEXT WEEK...WITH CHANCE FOR
ANOTHER LOW SLIDING EASTWARD FROM THE GREAT LAKES INTO NEW ENGLAND
MIDWEEK WITH CHANCE OF SNOW FOR PA.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
MVFR CIGS WILL LIKELY REMAIN IN PLACE AT BFD INTO TUESDAY WITH
NORTHWESTERLY WINDS AND A CHILLY...SHALLOW AIR MASS. CONTINUED
NORTHWESTERLY FLOW WILL MAKE A FEW FLURRIES AT BFD...BUT THE REST
OF THE TERMINALS WILL REMAIN DRY AND ONLY JST MAY SEE MVFR CIGS
OVERNIGHT. CLOUDS MAY LOWER AT IPT/UNV AS THE LOW CLOUD DECK
ASSOCIATED WITH THE COLDER AIR SLIDING DOWN FROM THE NORTH MOVES
SOUTHWARD. BUT...WILL KEEP IT AS VFR THRU THE TAF PERIOD FOR THE
TIME BEING.
HIGH PRESSURE CENTERED OVER THE FRONT RANGE OF THE ROCKIES AND THE
GREAT PLAINS WILL STRETCH FAR TO THE EAST AND GRADUALLY SINK
SOUTHWARD. A BRIEF SHOT OF COLDER AIR WITHIN A FEW HOURS OF 12Z
WED MAY CREATE A BROADER AREA OF SHSN/SQ. BUT THE REDUCTIONS IN
VIS/CIG SHOULD BE LIMITED TO BFD...AND NOT EVEN JST. THE WAVE
ALOFT WILL BE ACCOMPANIED BY VERY LITTLE MOISTURE. WINDS COULD
BECOME GUSTY...THOUGH.
OUTLOOK...
WED-FRI...VFR.
SAT...MVFR/IFR POSS IN WINTRY PRECIP.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...GRUMM/GARTNER
NEAR TERM...GRUMM/GARTNER
SHORT TERM...GRUMM
LONG TERM...RXR
AVIATION...DANGELO/GARTNER
AREA FORECAST DISCUSSION
NWS EL PASO TX/SANTA TERESA NM
258 PM MST TUE DEC 30 2014
.SYNOPSIS...
A COLD FRONT PUSHED WEST ACROSS MUCH OF THE BORDERLAND TODAY...
LEAVING IN IT`S WAKE COLD AIR AND INCREASING LOW CLOUDS FOR TONIGHT.
A PACIFIC FRONTAL SYSTEM WILL MOVE TO WESTERN ARIZONA WEDNESDAY.
THIS WILL PUSH CLOUDS IN AND KICK OFF SNOW SHOWERS OVER THE GILA AND
RAIN SHOWERS OVER THE LOWLANDS. MOST OF THIS ACTIVITY WILL END
THURSDAY FOR A BRIEF PERIOD BEFORE THE MAIN UPPER LOW MOVES OVER THE
AREA FRIDAY. THIS WILL SPREAD MORE RAIN AND SNOW SHOWERS...WITH THE
SACRAMENTO MOUNTAINS LIKELY SEEING HEAVY SNOW. MUCH OF THE LOWLANDS
COULD SEE A MIX OF RAIN AND SNOW BUT LITTLE OR NO ACCUMULATION. THE
LOW EXITS THE AREA FRIDAY NIGHT ALLOWING SKIES TO CLEAR. THROUGH MID
WEEK OF NEXT WEEK...THE PATTERN LOOKS TO REMAIN A DRY WITH
TEMPERATURES POSSIBLY BACK ABOVE NORMAL BY MONDAY.
&&
.DISCUSSION...
COMPLEX WINTER WEATHER PATTERN TO CONTINUE OVER THE NEXT 3 DAYS.
MODELS HAVE BEEN RELATIVELY CLOSE...BUT 12Z GFS RUN THROUGH SOME
DOUBT INTO FRIDAY SOLUTION. OTHERWISE FEW CHANGES MADE TO PREVIOUS
FORECAST PACKAGE.
BACK DOOR COLD FRONT SWEPT THROUGH THE RIO GRANDE VALLEY THIS
MORNING. SFC OBS SHOW FRONT MAYBE OUT TO THE ARIZONA BORDER. COOL
AIR LIKELY SHALLOW FROM DEMING WEST AS THOSE LOCATIONS WERE STILL
ABLE TO MODIFY THIS AFTERNOON. EXTENSIVE LOW CLOUDS HAVE BEEN DAMMED
UP AGAINST EASTERN TERRAIN ALL DAY. CLOUDS COVERED THE EASTERN SACS
AND ARE SLOWLY SEEPING INTO HUDSPETH COUNTY. SOME FREEZING FOG HAS
BEEN REPORTED...BUT PROG SOUNDINGS SUPPORT VERY LITTLE IN THE WAY OF
PRECIP OVERNIGHT. WILL KEEP FREEZING FOG ADV OUT FOR EASTERN SACS
AND ALSO ADD HUDSPETH COUNTY TO THE ADVISORY. TYPICAL PATTERN IS FOR
LOW CLOUDS TO ACCELERATE WESTWARD AFTER SUNSET. HRRR ALSO SHOWS
THIS...CLOUDING EL PASO CO OVER AROUND 6-7 PM...AND MOST OF THE REST
OF THE LOWLANDS TO THE DIVIDE BY AROUND MIDNIGHT.
LOW CLOUDS AND EAST PUSH WILL SLOWLY DIMINISH WEDNESDAY AS MAIN
UPPER LOW DESCENDS DOWN TO WESTERN ARIZONA AND SURFACE GRADIENT
BEGINS TO RELAX. NOT EXPECTING MUCH OF ANY PRECIP WEDNESDAY THOUGH
KEEPING LOW POPS IN SEEMS PRUDENT. PACIFIC UPPER LOW AND SURFACE
FRONT CONTINUE ADVANCING EAST. UPPER LOW PROGGED OVER EASTERN
ARIZONA THURSDAY MORNING...WITH ATTENDANT FRONT PUSHING EAST ACROSS
THE CWA. THIS WILL PRODUCE ANOTHER PERIOD SHOWERS...WITH SNOW LEVELS
MOSTLY ABOVE 5000 FT. WILL ISSUED WINTER WEATHER ADV FOR THE GILA
ZONES AS THIS SYSTEM LIKELY TO DROP DECENT SNOWFALL OVER THAT AREA.
SHOULD SEE BRIEF END TO PRECIP THURSDAY NIGHT AS UPPER LOW LIFTS
INTO COLORADO AND FRONT IS EAST OF THE AREA.
HANG BACK LOW FORMS SOUTHWEST OF ORIGINAL LOW AND WILL MOVE OVER
SOUTHERN NEW MEXICO FRIDAY. THIS IS WHERE THE 12Z GFS RUN DEVIATES
FROM THE OTHER MODELS. NAM/ECMWF STILL SHOWING STRONG PRESENCE OF
THIS LOW WITH HEAVY SNOW OVER THE SACS AND RAIN/SNOW OVER THE
LOWLANDS. WILL STILL KEEP THIS THINKING FOR NOW. SNOW LEVELS FRIDAY
LIKELY AT 4500-5000 FT SO SOME OF THE LOWLANDS COULD GET LIGHT SNOW
ACCUMULATIONS. MOST FAVORED AREA NORTH AND WEST OF LAS CRUCES WILL
HAVE TO BE WATCHED FOR POTENTIAL ADVISORIES. BELIEVE THE SACS WILL
GET HEAVY SNOW BUT TOO EARLY TO ISSUE AT THIS TIME...ESPECIALLY WITH
THE GFS UNCERTAINTY.
UPPER LOW EXITS FRIDAY NIGHT WITH CLEARING TO FOLLOW. SATURDAY
THROUGH TUESDAY PERIOD SHOULD REMAIN DRY AS WEST COAST UPPER RIDGE
PERSISTS. TEMPERATURES SHOULD SLOWLY WARM BACK TO NORMAL BY MONDAY
AND TUESDAY.
&&
.AVIATION...VALID 31/00Z-01/00Z...
THRU 06Z...P6SM FEW-SCT020 SCT-BKN150-200. AFT 06Z MOISTURE WILL BE
PUSHING WESTWARD WITH SCT-BKN010-020 BKN-OVC120-150 DEVELOPING AT
ALL TAF SITES WITH VERY PATCHY FZDZ POSSIBLE...MAINLY EAST OF KELP
AND POSSIBLY TOWARD KTCS. LOW CLOUDS WILL REMAIN IN PLACE EAST OF
RIO GRANDE...BUT POSSIBLY BECOME MORE SCT AFT 18Z WEST OF RIVER. E
TO NE WINDS 10-20G30KTS THRU PD...STRONGEST ON WESTERN MOUNTAIN
SLOPES.
&&
.FIRE WEATHER...
COLD FRONT HAS MOVED THROUGH THE REGION WITH GUSTY EAST WINDS IN
PLACE WHICH WILL CONTINUE THROUGH WEDNESDAY. VERY LIGHT
PRECIPITATION IN THE FORM OF FREEZING DRIZZLE IS POSSIBLE FAR NORTH
AND EAST TONIGHT...BUT DEEPER LOW LEVEL MOISTURE WILL BE PUSHING
WEST THROUGH THE NIGHT. SNOW IS EXPECTED OVER THE GILA REGION
STARTING WEDNESDAY NIGHT AND OVER THE SACS MAINLY LATE THURSDAY INTO
FRIDAY. SEVERAL INCHES OF SNOW ARE POSSIBLE IN EACH OF THESE
MOUNTAIN ZONES. LOWLANDS COULD SEE A MIX OF RAIN AND SNOW WITH ANY
ACCUMULATIONS REMAINING UNDER AN INCH. EXPECT BELOW NORMAL
TEMPERATURES TO REMAIN IN PLACE THROUGH THE WEEKEND BEFORE WARMER
AIR RETURNS EARLY NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
EL PASO 29 43 35 50 31 / 0 0 10 20 20
SIERRA BLANCA 24 36 29 46 30 / 20 20 10 20 20
LAS CRUCES 26 42 31 46 30 / 0 0 10 30 30
ALAMOGORDO 25 42 31 48 29 / 20 0 20 20 30
CLOUDCROFT 20 33 22 36 23 / 30 20 20 40 50
TRUTH OR CONSEQUENCES 25 42 30 42 26 / 10 20 30 30 30
SILVER CITY 25 41 28 37 25 / 0 10 50 50 30
DEMING 27 44 30 44 27 / 0 0 20 30 30
LORDSBURG 28 45 31 43 26 / 0 10 40 40 20
WEST EL PASO METRO 30 43 36 48 35 / 0 0 10 20 20
DELL CITY 22 33 28 45 25 / 20 20 20 20 20
FORT HANCOCK 26 41 33 51 29 / 10 10 10 10 20
LOMA LINDA 24 38 29 45 32 / 20 10 10 20 30
FABENS 27 42 34 49 29 / 0 0 10 20 20
SANTA TERESA 26 44 32 48 30 / 0 0 10 20 20
WHITE SANDS HQ 27 40 33 46 32 / 0 0 10 20 30
JORNADA RANGE 21 43 25 45 25 / 0 0 10 30 30
HATCH 25 44 30 46 28 / 0 10 20 30 30
COLUMBUS 30 45 34 45 32 / 0 0 10 30 20
OROGRANDE 25 40 30 46 30 / 10 0 10 20 30
MAYHILL 18 30 22 38 26 / 50 30 30 40 30
MESCALERO 18 34 22 40 24 / 30 20 20 40 50
TIMBERON 20 33 22 38 25 / 20 20 20 40 40
WINSTON 22 39 24 39 21 / 20 20 50 60 30
HILLSBORO 25 42 28 41 26 / 10 20 30 40 30
SPACEPORT 21 44 25 45 24 / 0 10 20 30 30
LAKE ROBERTS 24 42 25 37 24 / 0 20 60 70 30
HURLEY 25 42 28 40 26 / 0 10 40 40 20
CLIFF 22 47 31 40 20 / 0 10 70 60 20
MULE CREEK 19 46 24 38 17 / 0 10 80 70 30
FAYWOOD 27 41 30 40 28 / 0 10 30 40 30
ANIMAS 30 50 34 47 28 / 0 0 40 30 20
HACHITA 26 46 29 45 26 / 0 0 30 30 20
ANTELOPE WELLS 29 53 33 50 28 / 0 0 20 30 20
CLOVERDALE 32 55 34 46 27 / 0 0 40 40 30
&&
.EPZ WATCHES/WARNINGS/ADVISORIES...
NM...FREEZING FOG ADVISORY FROM 7 PM THIS EVENING TO 11 AM MST
WEDNESDAY FOR NMZ417.
WINTER WEATHER ADVISORY FROM 6 PM WEDNESDAY TO 11 AM MST
THURSDAY FOR NMZ401>403-408.
WIND ADVISORY UNTIL 11 AM MST WEDNESDAY FOR NMZ411.
FREEZING FOG ADVISORY UNTIL 11 AM MST WEDNESDAY FOR NMZ416.
TX...FREEZING FOG ADVISORY FROM 7 PM THIS EVENING TO 11 AM MST
WEDNESDAY FOR TXZ420>424.
WIND ADVISORY UNTIL 11 AM MST WEDNESDAY FOR TXZ418.
&&
$$
HEFNER/GRZYWACZ
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1216 PM CST TUE DEC 30 2014
.UPDATE...
COLDER AND SOMEWHAT DRIER AIR BEHIND THE ARCTIC COLD FRONT THAT
PASSED ABOUT MID MORNING. WINDS ALSO SLIGHTLY MORE NORTHERLY.
PRECIPITATION REMAINS LIGHT BUT ENOUGH FOR A LIGHT GLAZE ALMOST
EVERYWHERE...AND LATELY OVER SOUTHERN PART OF THE ROLLING PLAINS.
WIND CHILLS HAVE REMAINED BELOW MINUS 5 ACROSS NORTHWEST ZONES
WITH WINDS ONLY SLIGHTLY LOWER WHILE TEMPERATURES UNLIKELY TO RISE
THIS AFTERNOON. WE HAVE ADDED THE SOUTHERN PART OF THE ROLLING
PLAINS TO THE WINTER WEATHER ADVISORY NOW UNTIL 3 PM. ALSO ISSUED
A WIND CHILL ADVISORY FOR THE NORTHWEST UNTIL 3. MOST SOLUTIONS
CONTINUE TO GENERATE LIGHT PRECIPITATION TONIGHT PERHAPS SLIGHTLY
FAVORING SOUTHEAST ZONES BUT NOT CLEAR YET. RMCQUEEN
&&
.AVIATION...
WITH DRIER COLDER AIR MOVING IN WE EXPECT CEILINGS TO INCH BACK TO
NEAR LOWER END OF MVFR CEILINGS LATER TODAY. SOLUTIONS STILL SUGGEST
LOWERING CONDITIONS MAY BECOME PERVASIVE OVERNIGHT WITH EXPANDING
LIGHT PRECIPITATION FOR KLBB AND KPVW BUT NOT CERTAIN ENOUGH
EITHER FOR A CHANGE OR TEMPO GROUP. RMCQUEEN
&&
.PREV DISCUSSION... /ISSUED 921 AM CST TUE DEC 30 2014/
UPDATE...
ISSUED A WINTER WEATHER ADVISORY FOR FREEZING DRIZZLE ON THE
CAPROCK UNTIL NOON. MAY NEED TO EXTEND THIS AFTERNOON...AND IF SO
WILL CONSIDER GOING THROUGH MUCH OF THE NIGHT. VERY COLD AIR
MOVING SOUTHWARD SHOULD CHANGE FREEZING DRIZZLE MORE TO LIGHT SNOW
AND PERHAPS LESS ICE ACCUMULATIONS BUT NOT CERTAIN AT THIS TIME. RMCQUEEN
PREV DISCUSSION... /ISSUED 544 AM CST TUE DEC 30 2014/
UPDATE...
KLBB 88D SHOWING THE EXPANSION OF VERY LIGHT REFLECTIVTY /ZERO TO
MINUS 15 DBZ/ BTWN 1000 AND 5000 FT AGL AND LOWERING WITH TIME.
THIS SHOULD BE THE PERIOD OF VERY LIGHT FLURRIES AND/OR FREEZING
DRIZZLE ASSOCIATED WITH FRONTOGENTICAL FORCING. PER THE HRRR THIS
PRECIP SHOULD SHIFT SWD WITH THE FORCING THROUGH THE MORNING.
EXPECTATION IS IT SHOULD REMAIN TOO LIGHT CAUSE MUCH IN THE WAY OF
DIFFICULTY THIS MORNING...BUT WILL CONTINUE TO MONITOR TRENDS.
AVIATION...
CIGS TO LOWER A BIT MORE DURING THE FIRST PART OF THE FCST PERIOD
BUT SHOULD REMAIN MVFR THEN REMAIN PRETTY STABLE THROUGH THE
REMAINDER OF THE PERIOD. ANTICIPATE SOME PERIODS OF LIGHT FREEZING
DRIZZLE AND/OR FLURRIES THROUGH THE FCST TIME AS WELL. GUSTY NNE
WINDS THROUGH MUCH OF THE DAY SHOULD RELAX TOWARD EVENING.
PREV DISCUSSION... /ISSUED 428 AM CST TUE DEC 30 2014/
SHORT TERM...
THE COLD FRONT IS NOW WELL INTO THE PERMIAN BASIN AND BIG COUNTRY
WITH MUCH COLDER AIR FILTERING IN BEHIND IT RATHER THAN SURGING AT
THIS POINT. WITH A GOOD STRATUS DECK NOW IN PLACE...ALTHOUGH
NOT TERRIBLY LOW AT ABOUT 2000 FT AGL...AND LOW LEVEL COLD ADVECTION
PERSISTING THROUGH THE DAY...TEMPS WILL HAVE TROUBLE MOVING OFF OF
MORNING LOWS. INDEED...WILL LIKELY SEE TEMPS FALL THROUGH ABOUT
MID-MORNING BEFORE SOME SLIGHT RECOVERY LATER IN THE DAY.
HOWEVER...MAIN FOCUS CONTINUES TO BE ON CHANCE FOR VERY LIGHT
PRECIPITATION TODAY AND TONIGHT AND POTENTIAL IMPACTS OF IT WITH
TEMPS IN THE TEENS AND 20S. THIS PRECIP EVENT CONTINUES TO LOOK
PRIMARILY ISENTROPIC DRIVEN WITH SOME MINOR CONTRIBUTION FROM
FRONTOGENETICAL FORCING EARLY ON. ISENTROPIC PROJECTIONS DEPICT LIFT
INITIALLY AT THE VERY TOP OF THE COLD AIR...PRIMARILY IN THE WARMER
AND DRIER MID LEVELS ABOVE IT. HOWEVER...AS THE COLD AIR DEEPENS
THROUGH THE DAY...SOME OF THIS COLD MOISTURE SHOULD BE TAPPED BY THE
ISENTROPIC LIFT TO PRODUCE SOME LIGHT PRECIP. BEST WINDOW FOR THIS
APPEARS TO BE BETWEEN 3 PM AND MIDNIGHT...AFTER WHICH ISENTROPIC
LIFT WEAKENS SIGNIFICANTLY. QUESTION THEN BECOMES PHASE OF THIS
PRECIPITATION. PROGGED SOUNDINGS SUPPORT EITHER FREEZING DRIZZLE OR
VERY LIGHT SNOW. COLDER LOW LEVELS ACROSS THE NORTH AND WEST MIGHT
END UP FAVORING FLURRIES TO A DUSTING OF SNOW WHILE FURTHER SOUTH
AND EAST FREEZING DRIZZLE LIKELY TO BE PREDOMINANT. HOW MUCH IS A
BIG QUESTION WITH SOUNDINGS SUGGESTING THE MODEL QPF OUTPUT IS
OVERDONE.
AS FOR POTENTIAL FOR ADVISORY...STILL SOME DETAILS TO WORK OUT SUCH
AS FLURRIES VS DRIZZLE AND TIMING OF ONSET OF PRECIP HEAVY AND/OR
WIDESPREAD ENOUGH TO BEGIN TO CAUSE TRAVEL ISSUES. SINCE CURRENT
EXPECTATION IS THE MORE SIGNIFICANT PART OF THE EVENT IS STILL 8-12
HOURS AWAY AND ANOTHER MODEL RUN AND 12Z UA ANALYSIS SHOULD HELP
NARROW DOWN THE DETAILS FURTHER...WILL DEFER ON THE ISSUANCE OF AN
ADVISORY ATTM.
LONG TERM...
AN UA DISTURBANCE ACROSS THE GREAT BASIN IS STILL PROGGED TO PINCH
OFF AND DIVE SSE TO ACROSS SRN CALI TOMORROW...AND ACROSS THE DESERT
SW ON THURSDAY. AS SUCH...FLOW ALOFT WILL EVOLVE FROM A BROAD
CYCLONIC FLOW TO SWRLY FLOW. IF THE ANTICIPATED TRACK OF THE SYSTEM
DOES NOT CHANGE...IT WILL MOVE DIRECTLY ACROSS THE SOUTHERN PLAINS
FRIDAY NIGHT THEN EXIT TO THE NE BY SATURDAY. THEREAFTER...DRY NW
FLOW ALOFT WILL PREVAIL.
TEMPS STRUGGLING TO GET OUT OF THE 20S WILL CHARACTERIZE WEDNESDAY
AS THE CAA USHERED IN BY LAST NIGHT/S COLD FRONTAL PASSAGE REMAINS
ENTRENCHED. FURTHERMORE...MAY ALSO EXPERIENCE A LINGERING FREEZING
DRIZZLE/WINTRY MIX...COURTESY OF MOISTENED ATMOSPHERIC LOW LEVELS
AND AN UPSLOPE SFC REGIME. THIS WINTRY MIX MAY BE HARD-PRESSED TO
REACH THE GROUND AS IT WILL HAVE TO FALL THROUGH RATHER DRY
MID-LEVELS...WHICH IS WHERE THE SLIVER OF UL SUPPORT IS MAXIMIZED.
ON THURSDAY DURING THE DAY...A SIMILAR SCENARIO TO WEDNESDAY WILL
PLAY OUT...WITH THE DIFFERENCE BEING PROGGED MODEL SOUNDINGS HINTING
AT A WARM TONGUE DEVELOPING IN THE MID-LEVELS...THUS SUGGESTING
MORE OF A FREEZING RAIN/WINTRY MIX OCCURRENCE. NONETHELESS...THE
BEST LIFT IS STILL MAXIMIZED WITHIN THE DRY MID-LEVELS AND HENCE LIGHT
PRECIP IS EXPECTED. BY THURSDAY NIGHT HOWEVER...MID-LEVELS ARE
SHOWN TO MOISTEN AS THE UA SYSTEM DRAWS NEAR. THE BEST UL SUPPORT
IS FINALLY TAPPING INTO ADEQUATE MOISTURE. MID-LEVEL MOISTENING
OCCURRING WITHIN THE DENDRITIC ZONE COULD PROMOTE A CHANCE OF
SNOW...PARTICULARLY ACROSS THE HIGHER TERRAIN OF THE NWRN ZONES.
ELSEWHERE...FREEZING RAIN AND PERHAPS SLEET WILL BE COMMON...WITH
THE EXCEPTION OF THE FAR ROLLING PLAINS WHERE A MIX OF A COLD RAIN
AND FREEZING RAIN MAY OCCUR...GIVEN TEMPS WILL WARM TO SLIGHTLY
ABOVE FREEZING THERE /LOWER 30S ELSEWHERE/. TEMPS WILL WARMUP
FURTHER ON FRIDAY...INTO THE MIDDLE TO UPPER 30S ON THE CAPROCK
TO UPPER 30S TO LOWER 40S OFF THE CAPROCK...WHICH WILL AFFECT THE
PRECIP PHASE. COULD THEREFORE SEE MORE OF A RAIN AND SNOW MIX OR A
RAIN AND FREEZING RAIN MIX DEVELOP BY THE EVENING /THE NWRN ZONES
WILL BE THE EXCEPTION AS SOUNDING PROFILES SUGGEST LIGHT SNOW
THERE/.
LATE FRIDAY NIGHT-EARLY SATURDAY MORNING...LARGE SCALE ASCENT WILL
BE FLEETING AS THE SYSTEM COMMENCE TO EXIT THE REGION. PERHAPS SOME
LINGERING RAIN AND SNOW MIX WILL BE POSSIBLE ACROSS PORTIONS OF THE
ROLLING PLAINS EARLY SATURDAY MORNING. THEREAFTER...DRY NW FLOW
ALOFT WILL PREVAIL AND THE RETURN TO SRLY SFC FLOW EARLY NEXT
WEEK WILL AID IN PUSHING TEMPS BACK UP TO NEAR 50.
NOTE: ALTHOUGH THE WINTRY PRECIP IS EXPECTED TO BE LIGHT THIS
WEEK...IT COULD STILL POSE A THREAT FOR HAZARDOUS ROAD
CONDITIONS AS A THIN GLAZE OF ICE COULD FORM ACROSS OVERPASSES AND
BRIDGES IN PARTICULAR. AS YOU HEAD OUT TO ENJOY THE NEW YEAR
FESTIVITIES...CAUTION IS ADVISED. CHECK BACK TO STAY ALERT AND UP TO
DATE WITH ANY WEATHER CHANGES.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 7 22 17 32 20 / 40 20 10 20 20
TULIA 10 22 19 32 23 / 40 10 10 20 20
PLAINVIEW 12 23 19 32 25 / 40 10 10 20 20
LEVELLAND 14 24 19 32 25 / 50 20 20 20 30
LUBBOCK 14 25 21 32 26 / 50 20 20 20 30
DENVER CITY 16 25 20 33 26 / 50 20 20 30 30
BROWNFIELD 15 25 20 33 26 / 50 20 20 30 30
CHILDRESS 14 25 22 34 26 / 40 10 10 20 30
SPUR 15 25 22 33 27 / 50 20 20 30 30
ASPERMONT 18 27 24 36 29 / 40 20 20 30 30
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR THE
FOLLOWING ZONES: TXZ021>024-027>030-033>037-039>044.
WIND CHILL ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR THE
FOLLOWING ZONES: TXZ021>023.
&&
$$
05/99/05
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1006 AM CST TUE DEC 30 2014
.UPDATE...
WITH FOG BEGINNING TO LIFT IN MANY AREAS EAST OF THE I35
CORRIDOR...ALLOWED THE DENSE FOG ADVISORY TO EXPIRE OUT THERE.
HOWEVER...FOG IS SLUGGISH TO LIFT ON THE ESCARPMENT AND SOME
LOCATIONS IN THE EASTERN PARTS OF THE I35 CORRIDOR COUNTIES ARE
STILL SEEING VISIBILITIES RISE AND FALL. EXPECT THIS TO IMPROVE
OVER THE NEXT TWO HOURS SO EXTENDED THE DFA THROUGH 18Z TO BE
SAFE.
TB3
&&
.PREV DISCUSSION... /ISSUED 725 AM CST TUE DEC 30 2014/
UPDATE...ONE FINAL UPDATE TO EXPAND DENSE FOG ADVISORY WEST TO
THE RIO GRANDE.
PREV DISCUSSION... /ISSUED 613 AM CST TUE DEC 30 2014/
AVIATION...
LIFR/VLIFR VIS AND CIGS IN AUSTIN AND SAN ANTONIO THIS MORNING
WILL CONTINUE UNTIL MID-MORNING WHEN NORTHWESTERLY WINDS PICK UP.
THEN MVFR/IFR CIGS THROUGH THE REST OF THE TAF PERIOD. DRT WILL
DROP TO IFR SHORTLY AND STAY THAT WAY UNTIL AROUND 18Z. EXPECTING
PRECIPITATION WEDNESDAY MORNING AT DRT. HAVE NOT INCLUDED ANY
PRECIP IN AUSTIN OR SAN ANTONIO...BUT THERE IS A SLIGHT CHANCE FOR
RAIN. IF THERE IS ANY RAIN IT WILL DROP VIS TO MVFR.
PREV DISCUSSION... /ISSUED 523 AM CST TUE DEC 30 2014/
UPDATE...SECOND UPDATE TO EXPAND DENSE FOG ADVISORY FARTHER WEST
AND SOUTH BASED ON SATELLITE AND WEB CAM TRENDS. THIS ALSO LINES
UP WELL WITH HRRR EXPANSION OF FOG.
PREV DISCUSSION... /ISSUED 443 AM CST TUE DEC 30 2014/
UPDATE...QUICK UPDATE TO ISSUE DENSE FOG ADVISORY FOR I-35
CORRIDOR FROM COMAL TO WILLIAMSON COUNTY EASTWARD. THIS IS BASED ON
SEVERAL WEBCAMS AND OBS INDICATING DENSE FOG. THERE IS ALSO THE
POTENTIAL FOR PATCHY TO AREAS OF DENSE FOG SOUTH AND WEST OF THE
ADVISORY AREA THROUGH THE MORNING.
PREV DISCUSSION... /ISSUED 401 AM CST TUE DEC 30 2014/
SHORT TERM (TODAY THROUGH WEDNESDAY)...AREAS OF LOW STRATUS AND
FOG HAVE FORMED ACROSS EASTERN AREAS AS WELL AS ALONG THE RIO
GRANDE EARLY THIS MORNING. THE FOG AND CLOUDS WILL CONTINUE TO
EXPAND INTO THE I-35 CORRIDOR AND PORTIONS OF THE HILL COUNTRY
THROUGH THE MORNING HOURS.
THE MUCH ADVERTISED ARCTIC AIRMASS HAS MOVED THROUGH THE HILL
COUNTRY AND INTO WEST TEXAS. THE AIRMASS IN RELATIVELY DENSE
BEHIND A 1055MB HIGH ANALYZED UP IN MONTANA. THE AIRMASS WILL
GRADUALLY FILTER INTO SOUTH-CENTRAL TEXAS TODAY AND TONIGHT.
ISENTROPIC ASCENT ABOVE THE SHALLOW...COLD AIRMASS WELL DEVELOP
TONIGHT AND GRADUALLY STRENGTHEN WEDNESDAY AND WEDNESDAY NIGHT.
INITIALLY THICK CLOUDS WILL RESULT FROM THIS...WITH ONLY PATCHY
DRIZZLE AND PATCHY LIGHT RAIN DEVELOPING ACROSS THE WESTERN CWA
TONIGHT AND EXPANDING EAST ON WEDNESDAY. THE GFS CONTINUES TO BE
DRIER IN THE LOWEST LEVELS TODAY THROUGH WEDNESDAY...TAKING LONGER
TO MOISTEN. HOWEVER FORECAST SOUNDINGS FROM THE HRRR/ARW/NMM AS
WELL AS NAM12 ARE NOT QUITE AS AGGRESSIVE WITH THIS DRY LAYER AND
MOISTENS FASTER. HAVE FOLLOWED SLIGHTLY CLOSER TO THE LATTER. THIS
COULD POTENTIALLY RESULT IN PATCHY FREEZING DRIZZLE AND FREEZING
LIGHT RAIN ALONG AND NORTH OF A PANDALE TO LEAKY TO JOHNSON CITY
TO BURNET LINE EARLY WEDNESDAY MORNING. QPF AMOUNTS SHOULD BE VERY
LIGHT...AND GIVEN GROUND TEMPS AND PATCHY COVERAGE IMPACTS SHOULD
BE LIMITED TO ELEVATED SURFACES WITH MINIMAL TRAVEL IMPACTS.
ON WEDNESDAY VERY LITTLE DIURNAL TEMPERATURE RANGE IS EXPECTED...
WITH HIGHS ONLY CLIMBING INTO THE MID 30S ACROSS THE HILL COUNTRY
(WITH A FEW ISOLATED HILL COUNTRY SPOTS REMAINING IN THE LOW
30S)...UPPER 30S ALONG THE I-35 CORRIDOR AND LOW 40S ALONG THE RIO
GRANDE AS WELL AS FAR SOUTHERN/SOUTHEAST AREAS.
LONG TERM (WEDNESDAY NIGHT THROUGH MONDAY)...
FREEZING RAIN WITH TRAVEL IMPACTS POSSIBLE LATE NEW YEARS EVE
INTO NEW YEARS DAY ACROSS THE HILL COUNTRY. WINTER STORM WATCH POSTED...
THE UPPER LEVEL LOW ACROSS SOUTHERN CALIFORNIA IS FORECAST TO
MOVE EAST INTO ARIZONA NEW YEARS EVE NIGHT INTO NEW YEARS DAY. THE
ISENTROPIC UPGLIDE OVER THE COLD AIRMASS STRENGTHENS WEST TO EAST
DURING THIS TIME. SEVERAL MODELS HAVE BEEN INDICATING FOR A FEW
RUNS NOW A MID AND UPPER LEVEL SHORTWAVE IN THE SOUTHWEST FLOW
ALOFT MOVING OUT OF MEXICO AND INTO WEST-CENTRAL TEXAS AND THE
HILL COUNTRY LATE WEDNESDAY NIGHT AND THURSDAY. GFS AND ECMWF BOTH
SHOW ENHANCED BAND OF QPF CLIPPING THE HILL COUNTRY...ALONG WITH
SREF OUTPUT. CONFIDENCE CONTINUES TO GROW IN FREEZING RAIN EVENT
LATE WEDNESDAY NIGHT THROUGH MIDDAY THURSDAY ACROSS AT LEAST THE
HILL COUNTRY. THE WARM CLOUD LAYER DEPTH IS INCREASING DURING THIS
TIME...BUT CAN NOT COMPLETELY RULE OUT SLEET MIXING IN ACROSS THE
NORTHERN HILL COUNTRY AS WELL. GIVEN HOLIDAY TRAVEL SENSITIVITY...
AND AFTER COORDINATION WITH SURROUNDING WFOS...WE HAVE DECIDED TO
ISSUE A WINTER STORM WATCH FOR THE HILL COUNTRY...ALONG AND NORTH
OF A VAL VERDE TO BANDERA TO BURNET COUNTY LINE. IF TEMPS AND
ENHANCEMENT IN QPF VERIFY...THERE COULD BE A BAND ACROSS THE
NORTHERN HILL COUNTRY OF HIGHER ICE ACCUMULATION AMOUNTS.
FARTHER EAST ALONG THE I-35 CORRIDOR...TEMPERATURES WILL BE VERY
CLOSE TO FREEZING EARLY THURSDAY MORNING. ALTHOUGH THESE COUNTIES
ARE NOT CURRENTLY IN THE WATCH...THE FREEZING RAIN LINE IS
FORECAST TO REACH A HELOTES TO WIMBERLEY TO GEORGETOWN LINE. ANY
TRENDS DOWNWARD IN THE TEMP FORECAST...OR WET-BULB COOLING...COULD
PUSH THIS LINE TOWARDS THE AUSTIN AND NORTHERN SAN ANTONIO METRO
AREAS. THOSE WITH TRAVEL PLANS NEW YEARS EVE NIGHT INTO NEW YEARS
DAY ALONG THE INTERSTATE 35 CORRIDOR SHOULD CLOSELY MONITOR FOR
ANY FORECASTS UPDATES.
MODELS ARE SLIGHTLY SLOWER WITH HOW FAST THE UPPER LEVEL LOW
EJECTS OUT INTO THE PLAINS FROM RUNS A FEW DAYS AGO. THE UPPER
LEVEL LOW MOVES ACROSS SOUTHERN NEW MEXICO FRIDAY AND NORTHEAST
THROUGH WEST TEXAS FRIDAY NIGHT INTO SATURDAY MORNING. GOOD
CHANCES FOR RAIN WILL CONTINUE ACROSS THE REGION THURSDAY NIGHT
THROUGH FRIDAY NIGHT. THE WARM CLOUD LAYER CONTINUES TO WARM
FURTHER WITH SLIGHT MODIFICATION IN THE COLD AIRMASS BELOW. PRECIP
WILL REMAIN ALL LIQUID DURING THIS TIME (ALTHOUGH MAY HAVE TO
WATCH CLOSELY ACROSS FAR NORTHERN AREAS OF THE CWA THURSDAY
NIGHT). IN ADDITION...THERE WILL ALSO BE THE POTENTIAL FOR
EMBEDDED THUNDER THURSDAY NIGHT THROUGH FRIDAY NIGHT AS ELEVATED
LAPSE RATES STEEPEN...AND HAVE CONTINUED THIS IN THE FORECAST.
CLEARING AND DRYING TAKES PLACE DOES EVENTUALLY TAKE PLACE
WEST TO EAST SATURDAY WITH HIGHS TEMPS WARMING BACK TO TOWARDS
SEASONABLE LEVELS OVER THE WEEKEND AND INTO EARLY NEXT WEEK.
JR
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 52 34 38 34 40 / 10 10 20 30 60
AUSTIN BERGSTROM INTL AIRPORT 52 35 38 34 40 / 10 10 20 30 60
NEW BRAUNFELS MUNI AIRPORT 54 36 38 34 39 / 10 10 20 30 50
BURNET MUNI AIRPORT 48 30 36 29 37 / 10 10 20 30 60
DEL RIO INTL AIRPORT 54 36 41 33 44 / 10 40 30 30 20
GEORGETOWN MUNI AIRPORT 49 32 36 31 38 / 10 10 20 30 60
HONDO MUNI AIRPORT 56 36 39 33 42 / 10 20 20 30 40
SAN MARCOS MUNI AIRPORT 53 35 38 34 40 / 10 10 20 30 60
LA GRANGE - FAYETTE REGIONAL 55 36 41 36 42 / 10 10 20 30 50
SAN ANTONIO INTL AIRPORT 55 36 39 35 41 / 10 10 20 30 50
STINSON MUNI AIRPORT 56 38 39 36 41 / 10 10 20 30 50
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL NOON CST TODAY FOR THE FOLLOWING COUNTIES:
BANDERA...BEXAR...BLANCO...BURNET...COMAL...EDWARDS...GILLESPIE...
HAYS...KENDALL...KERR...KINNEY...LLANO...MAVERICK...MEDINA...REAL...
TRAVIS...UVALDE...VAL VERDE...WILLIAMSON...ZAVALA.
WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY MORNING
FOR THE FOLLOWING COUNTIES: BANDERA...BLANCO...BURNET...EDWARDS...
GILLESPIE...KENDALL...KERR...LLANO...REAL...VAL VERDE.
&&
$$
MESOSCALE/AVIATION...03
SYNOPTIC/GRIDS...12
PUBLIC SERVICE/DATA COLLECTION...00
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
921 AM CST TUE DEC 30 2014
.UPDATE...
ISSUED A WINTER WEATHER ADVISORY FOR FREEZING DRIZZLE ON THE
CAPROCK UNTIL NOON. MAY NEED TO EXTEND THIS AFTERNOON...AND IF SO
WILL CONSIDER GOING THROUGH MUCH OF THE NIGHT. VERY COLD AIR
MOVING SOUTHWARD SHOULD CHANGE FREEZING DRIZZLE MORE TO LIGHT SNOW
AND PERHAPS LESS ICE ACCUMULATIONS BUT NOT CERTAIN AT THIS TIME. RMCQUEEN
&&
.PREV DISCUSSION... /ISSUED 544 AM CST TUE DEC 30 2014/
UPDATE...
KLBB 88D SHOWING THE EXPANSION OF VERY LIGHT REFLECTIVTY /ZERO TO
MINUS 15 DBZ/ BTWN 1000 AND 5000 FT AGL AND LOWERING WITH TIME.
THIS SHOULD BE THE PERIOD OF VERY LIGHT FLURRIES AND/OR FREEZING
DRIZZLE ASSOCIATED WITH FRONTOGENTICAL FORCING. PER THE HRRR THIS
PRECIP SHOULD SHIFT SWD WITH THE FORCING THROUGH THE MORNING.
EXPECTATION IS IT SHOULD REMAIN TOO LIGHT CAUSE MUCH IN THE WAY OF
DIFFICULTY THIS MORNING...BUT WILL CONTINUE TO MONITOR TRENDS.
AVIATION...
CIGS TO LOWER A BIT MORE DURING THE FIRST PART OF THE FCST PERIOD
BUT SHOULD REMAIN MVFR THEN REMAIN PRETTY STABLE THROUGH THE
REMAINDER OF THE PERIOD. ANTICIPATE SOME PERIODS OF LIGHT FREEZING
DRIZZLE AND/OR FLURRIES THROUGH THE FCST TIME AS WELL. GUSTY NNE
WINDS THROUGH MUCH OF THE DAY SHOULD RELAX TOWARD EVENING.
PREV DISCUSSION... /ISSUED 428 AM CST TUE DEC 30 2014/
SHORT TERM...
THE COLD FRONT IS NOW WELL INTO THE PERMIAN BASIN AND BIG COUNTRY
WITH MUCH COLDER AIR FILTERING IN BEHIND IT RATHER THAN SURGING AT
THIS POINT. WITH A GOOD STRATUS DECK NOW IN PLACE...ALTHOUGH
NOT TERRIBLY LOW AT ABOUT 2000 FT AGL...AND LOW LEVEL COLD ADVECTION
PERSISTING THROUGH THE DAY...TEMPS WILL HAVE TROUBLE MOVING OFF OF
MORNING LOWS. INDEED...WILL LIKELY SEE TEMPS FALL THROUGH ABOUT
MID-MORNING BEFORE SOME SLIGHT RECOVERY LATER IN THE DAY.
HOWEVER...MAIN FOCUS CONTINUES TO BE ON CHANCE FOR VERY LIGHT
PRECIPITATION TODAY AND TONIGHT AND POTENTIAL IMPACTS OF IT WITH
TEMPS IN THE TEENS AND 20S. THIS PRECIP EVENT CONTINUES TO LOOK
PRIMARILY ISENTROPIC DRIVEN WITH SOME MINOR CONTRIBUTION FROM
FRONTOGENETICAL FORCING EARLY ON. ISENTROPIC PROJECTIONS DEPICT LIFT
INITIALLY AT THE VERY TOP OF THE COLD AIR...PRIMARILY IN THE WARMER
AND DRIER MID LEVELS ABOVE IT. HOWEVER...AS THE COLD AIR DEEPENS
THROUGH THE DAY...SOME OF THIS COLD MOISTURE SHOULD BE TAPPED BY THE
ISENTROPIC LIFT TO PRODUCE SOME LIGHT PRECIP. BEST WINDOW FOR THIS
APPEARS TO BE BETWEEN 3 PM AND MIDNIGHT...AFTER WHICH ISENTROPIC
LIFT WEAKENS SIGNIFICANTLY. QUESTION THEN BECOMES PHASE OF THIS
PRECIPITATION. PROGGED SOUNDINGS SUPPORT EITHER FREEZING DRIZZLE OR
VERY LIGHT SNOW. COLDER LOW LEVELS ACROSS THE NORTH AND WEST MIGHT
END UP FAVORING FLURRIES TO A DUSTING OF SNOW WHILE FURTHER SOUTH
AND EAST FREEZING DRIZZLE LIKELY TO BE PREDOMINANT. HOW MUCH IS A
BIG QUESTION WITH SOUNDINGS SUGGESTING THE MODEL QPF OUTPUT IS
OVERDONE.
AS FOR POTENTIAL FOR ADVISORY...STILL SOME DETAILS TO WORK OUT SUCH
AS FLURRIES VS DRIZZLE AND TIMING OF ONSET OF PRECIP HEAVY AND/OR
WIDESPREAD ENOUGH TO BEGIN TO CAUSE TRAVEL ISSUES. SINCE CURRENT
EXPECTATION IS THE MORE SIGNIFICANT PART OF THE EVENT IS STILL 8-12
HOURS AWAY AND ANOTHER MODEL RUN AND 12Z UA ANALYSIS SHOULD HELP
NARROW DOWN THE DETAILS FURTHER...WILL DEFER ON THE ISSUANCE OF AN
ADVISORY ATTM.
LONG TERM...
AN UA DISTURBANCE ACROSS THE GREAT BASIN IS STILL PROGGED TO PINCH
OFF AND DIVE SSE TO ACROSS SRN CALI TOMORROW...AND ACROSS THE DESERT
SW ON THURSDAY. AS SUCH...FLOW ALOFT WILL EVOLVE FROM A BROAD
CYCLONIC FLOW TO SWRLY FLOW. IF THE ANTICIPATED TRACK OF THE SYSTEM
DOES NOT CHANGE...IT WILL MOVE DIRECTLY ACROSS THE SOUTHERN PLAINS
FRIDAY NIGHT THEN EXIT TO THE NE BY SATURDAY. THEREAFTER...DRY NW
FLOW ALOFT WILL PREVAIL.
TEMPS STRUGGLING TO GET OUT OF THE 20S WILL CHARACTERIZE WEDNESDAY
AS THE CAA USHERED IN BY LAST NIGHT/S COLD FRONTAL PASSAGE REMAINS
ENTRENCHED. FURTHERMORE...MAY ALSO EXPERIENCE A LINGERING FREEZING
DRIZZLE/WINTRY MIX...COURTESY OF MOISTENED ATMOSPHERIC LOW LEVELS
AND AN UPSLOPE SFC REGIME. THIS WINTRY MIX MAY BE HARD-PRESSED TO
REACH THE GROUND AS IT WILL HAVE TO FALL THROUGH RATHER DRY
MID-LEVELS...WHICH IS WHERE THE SLIVER OF UL SUPPORT IS MAXIMIZED.
ON THURSDAY DURING THE DAY...A SIMILAR SCENARIO TO WEDNESDAY WILL
PLAY OUT...WITH THE DIFFERENCE BEING PROGGED MODEL SOUNDINGS HINTING
AT A WARM TONGUE DEVELOPING IN THE MID-LEVELS...THUS SUGGESTING
MORE OF A FREEZING RAIN/WINTRY MIX OCCURRENCE. NONETHELESS...THE
BEST LIFT IS STILL MAXIMIZED WITHIN THE DRY MID-LEVELS AND HENCE LIGHT
PRECIP IS EXPECTED. BY THURSDAY NIGHT HOWEVER...MID-LEVELS ARE
SHOWN TO MOISTEN AS THE UA SYSTEM DRAWS NEAR. THE BEST UL SUPPORT
IS FINALLY TAPPING INTO ADEQUATE MOISTURE. MID-LEVEL MOISTENING
OCCURRING WITHIN THE DENDRITIC ZONE COULD PROMOTE A CHANCE OF
SNOW...PARTICULARLY ACROSS THE HIGHER TERRAIN OF THE NWRN ZONES.
ELSEWHERE...FREEZING RAIN AND PERHAPS SLEET WILL BE COMMON...WITH
THE EXCEPTION OF THE FAR ROLLING PLAINS WHERE A MIX OF A COLD RAIN
AND FREEZING RAIN MAY OCCUR...GIVEN TEMPS WILL WARM TO SLIGHTLY
ABOVE FREEZING THERE /LOWER 30S ELSEWHERE/. TEMPS WILL WARMUP
FURTHER ON FRIDAY...INTO THE MIDDLE TO UPPER 30S ON THE CAPROCK
TO UPPER 30S TO LOWER 40S OFF THE CAPROCK...WHICH WILL AFFECT THE
PRECIP PHASE. COULD THEREFORE SEE MORE OF A RAIN AND SNOW MIX OR A
RAIN AND FREEZING RAIN MIX DEVELOP BY THE EVENING /THE NWRN ZONES
WILL BE THE EXCEPTION AS SOUNDING PROFILES SUGGEST LIGHT SNOW
THERE/.
LATE FRIDAY NIGHT-EARLY SATURDAY MORNING...LARGE SCALE ASCENT WILL
BE FLEETING AS THE SYSTEM COMMENCE TO EXIT THE REGION. PERHAPS SOME
LINGERING RAIN AND SNOW MIX WILL BE POSSIBLE ACROSS PORTIONS OF THE
ROLLING PLAINS EARLY SATURDAY MORNING. THEREAFTER...DRY NW FLOW
ALOFT WILL PREVAIL AND THE RETURN TO SRLY SFC FLOW EARLY NEXT
WEEK WILL AID IN PUSHING TEMPS BACK UP TO NEAR 50.
NOTE: ALTHOUGH THE WINTRY PRECIP IS EXPECTED TO BE LIGHT THIS
WEEK...IT COULD STILL POSE A THREAT FOR HAZARDOUS ROAD
CONDITIONS AS A THIN GLAZE OF ICE COULD FORM ACROSS OVERPASSES AND
BRIDGES IN PARTICULAR. AS YOU HEAD OUT TO ENJOY THE NEW YEAR
FESTIVITIES...CAUTION IS ADVISED. CHECK BACK TO STAY ALERT AND UP TO
DATE WITH ANY WEATHER CHANGES.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 20 11 22 17 32 / 30 40 20 10 20
TULIA 22 13 22 19 32 / 30 40 10 10 20
PLAINVIEW 23 14 23 19 32 / 30 40 10 10 20
LEVELLAND 24 16 24 19 32 / 40 50 20 20 20
LUBBOCK 25 16 25 21 32 / 40 50 20 20 20
DENVER CITY 27 18 25 20 33 / 40 50 20 20 30
BROWNFIELD 27 18 25 20 33 / 40 50 20 20 30
CHILDRESS 28 18 25 22 34 / 30 40 10 10 20
SPUR 28 18 25 22 33 / 30 50 20 20 30
ASPERMONT 30 20 27 24 36 / 30 40 20 20 30
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR THE FOLLOWING
ZONES: TXZ021>024-027>030-033>036-039>042.
&&
$$
05/99
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
725 AM CST TUE DEC 30 2014
.UPDATE...ONE FINAL UPDATE TO EXPAND DENSE FOG ADVISORY WEST TO
THE RIO GRANDE.
&&
.PREV DISCUSSION... /ISSUED 613 AM CST TUE DEC 30 2014/
AVIATION...
LIFR/VLIFR VIS AND CIGS IN AUSTIN AND SAN ANTONIO THIS MORNING
WILL CONTINUE UNTIL MID-MORNING WHEN NORTHWESTERLY WINDS PICK UP.
THEN MVFR/IFR CIGS THROUGH THE REST OF THE TAF PERIOD. DRT WILL
DROP TO IFR SHORTLY AND STAY THAT WAY UNTIL AROUND 18Z. EXPECTING
PRECIPITATION WEDNESDAY MORNING AT DRT. HAVE NOT INCLUDED ANY
PRECIP IN AUSTIN OR SAN ANTONIO...BUT THERE IS A SLIGHT CHANCE FOR
RAIN. IF THERE IS ANY RAIN IT WILL DROP VIS TO MVFR.
PREV DISCUSSION... /ISSUED 523 AM CST TUE DEC 30 2014/
UPDATE...SECOND UPDATE TO EXPAND DENSE FOG ADVISORY FARTHER WEST
AND SOUTH BASED ON SATELLITE AND WEB CAM TRENDS. THIS ALSO LINES
UP WELL WITH HRRR EXPANSION OF FOG.
PREV DISCUSSION... /ISSUED 443 AM CST TUE DEC 30 2014/
UPDATE...QUICK UPDATE TO ISSUE DENSE FOG ADVISORY FOR I-35
CORRIDOR FROM COMAL TO WILLIAMSON COUNTY EASTWARD. THIS IS BASED ON
SEVERAL WEBCAMS AND OBS INDICATING DENSE FOG. THERE IS ALSO THE
POTENTIAL FOR PATCHY TO AREAS OF DENSE FOG SOUTH AND WEST OF THE
ADVISORY AREA THROUGH THE MORNING.
PREV DISCUSSION... /ISSUED 401 AM CST TUE DEC 30 2014/
SHORT TERM (TODAY THROUGH WEDNESDAY)...AREAS OF LOW STRATUS AND
FOG HAVE FORMED ACROSS EASTERN AREAS AS WELL AS ALONG THE RIO
GRANDE EARLY THIS MORNING. THE FOG AND CLOUDS WILL CONTINUE TO
EXPAND INTO THE I-35 CORRIDOR AND PORTIONS OF THE HILL COUNTRY
THROUGH THE MORNING HOURS.
THE MUCH ADVERTISED ARCTIC AIRMASS HAS MOVED THROUGH THE HILL
COUNTRY AND INTO WEST TEXAS. THE AIRMASS IN RELATIVELY DENSE
BEHIND A 1055MB HIGH ANALYZED UP IN MONTANA. THE AIRMASS WILL
GRADUALLY FILTER INTO SOUTH-CENTRAL TEXAS TODAY AND TONIGHT.
ISENTROPIC ASCENT ABOVE THE SHALLOW...COLD AIRMASS WELL DEVELOP
TONIGHT AND GRADUALLY STRENGTHEN WEDNESDAY AND WEDNESDAY NIGHT.
INITIALLY THICK CLOUDS WILL RESULT FROM THIS...WITH ONLY PATCHY
DRIZZLE AND PATCHY LIGHT RAIN DEVELOPING ACROSS THE WESTERN CWA
TONIGHT AND EXPANDING EAST ON WEDNESDAY. THE GFS CONTINUES TO BE
DRIER IN THE LOWEST LEVELS TODAY THROUGH WEDNESDAY...TAKING LONGER
TO MOISTEN. HOWEVER FORECAST SOUNDINGS FROM THE HRRR/ARW/NMM AS
WELL AS NAM12 ARE NOT QUITE AS AGGRESSIVE WITH THIS DRY LAYER AND
MOISTENS FASTER. HAVE FOLLOWED SLIGHTLY CLOSER TO THE LATTER. THIS
COULD POTENTIALLY RESULT IN PATCHY FREEZING DRIZZLE AND FREEZING
LIGHT RAIN ALONG AND NORTH OF A PANDALE TO LEAKY TO JOHNSON CITY
TO BURNET LINE EARLY WEDNESDAY MORNING. QPF AMOUNTS SHOULD BE VERY
LIGHT...AND GIVEN GROUND TEMPS AND PATCHY COVERAGE IMPACTS SHOULD
BE LIMITED TO ELEVATED SURFACES WITH MINIMAL TRAVEL IMPACTS.
ON WEDNESDAY VERY LITTLE DIURNAL TEMPERATURE RANGE IS EXPECTED...
WITH HIGHS ONLY CLIMBING INTO THE MID 30S ACROSS THE HILL COUNTRY
(WITH A FEW ISOLATED HILL COUNTRY SPOTS REMAINING IN THE LOW
30S)...UPPER 30S ALONG THE I-35 CORRIDOR AND LOW 40S ALONG THE RIO
GRANDE AS WELL AS FAR SOUTHERN/SOUTHEAST AREAS.
LONG TERM (WEDNESDAY NIGHT THROUGH MONDAY)...
FREEZING RAIN WITH TRAVEL IMPACTS POSSIBLE LATE NEW YEARS EVE
INTO NEW YEARS DAY ACROSS THE HILL COUNTRY. WINTER STORM WATCH POSTED...
THE UPPER LEVEL LOW ACROSS SOUTHERN CALIFORNIA IS FORECAST TO
MOVE EAST INTO ARIZONA NEW YEARS EVE NIGHT INTO NEW YEARS DAY. THE
ISENTROPIC UPGLIDE OVER THE COLD AIRMASS STRENGTHENS WEST TO EAST
DURING THIS TIME. SEVERAL MODELS HAVE BEEN INDICATING FOR A FEW
RUNS NOW A MID AND UPPER LEVEL SHORTWAVE IN THE SOUTHWEST FLOW
ALOFT MOVING OUT OF MEXICO AND INTO WEST-CENTRAL TEXAS AND THE
HILL COUNTRY LATE WEDNESDAY NIGHT AND THURSDAY. GFS AND ECMWF BOTH
SHOW ENHANCED BAND OF QPF CLIPPING THE HILL COUNTRY...ALONG WITH
SREF OUTPUT. CONFIDENCE CONTINUES TO GROW IN FREEZING RAIN EVENT
LATE WEDNESDAY NIGHT THROUGH MIDDAY THURSDAY ACROSS AT LEAST THE
HILL COUNTRY. THE WARM CLOUD LAYER DEPTH IS INCREASING DURING THIS
TIME...BUT CAN NOT COMPLETELY RULE OUT SLEET MIXING IN ACROSS THE
NORTHERN HILL COUNTRY AS WELL. GIVEN HOLIDAY TRAVEL SENSITIVITY...
AND AFTER COORDINATION WITH SURROUNDING WFOS...WE HAVE DECIDED TO
ISSUE A WINTER STORM WATCH FOR THE HILL COUNTRY...ALONG AND NORTH
OF A VAL VERDE TO BANDERA TO BURNET COUNTY LINE. IF TEMPS AND
ENHANCEMENT IN QPF VERIFY...THERE COULD BE A BAND ACROSS THE
NORTHERN HILL COUNTRY OF HIGHER ICE ACCUMULATION AMOUNTS.
FARTHER EAST ALONG THE I-35 CORRIDOR...TEMPERATURES WILL BE VERY
CLOSE TO FREEZING EARLY THURSDAY MORNING. ALTHOUGH THESE COUNTIES
ARE NOT CURRENTLY IN THE WATCH...THE FREEZING RAIN LINE IS
FORECAST TO REACH A HELOTES TO WIMBERLEY TO GEORGETOWN LINE. ANY
TRENDS DOWNWARD IN THE TEMP FORECAST...OR WET-BULB COOLING...COULD
PUSH THIS LINE TOWARDS THE AUSTIN AND NORTHERN SAN ANTONIO METRO
AREAS. THOSE WITH TRAVEL PLANS NEW YEARS EVE NIGHT INTO NEW YEARS
DAY ALONG THE INTERSTATE 35 CORRIDOR SHOULD CLOSELY MONITOR FOR
ANY FORECASTS UPDATES.
MODELS ARE SLIGHTLY SLOWER WITH HOW FAST THE UPPER LEVEL LOW
EJECTS OUT INTO THE PLAINS FROM RUNS A FEW DAYS AGO. THE UPPER
LEVEL LOW MOVES ACROSS SOUTHERN NEW MEXICO FRIDAY AND NORTHEAST
THROUGH WEST TEXAS FRIDAY NIGHT INTO SATURDAY MORNING. GOOD
CHANCES FOR RAIN WILL CONTINUE ACROSS THE REGION THURSDAY NIGHT
THROUGH FRIDAY NIGHT. THE WARM CLOUD LAYER CONTINUES TO WARM
FURTHER WITH SLIGHT MODIFICATION IN THE COLD AIRMASS BELOW. PRECIP
WILL REMAIN ALL LIQUID DURING THIS TIME (ALTHOUGH MAY HAVE TO
WATCH CLOSELY ACROSS FAR NORTHERN AREAS OF THE CWA THURSDAY
NIGHT). IN ADDITION...THERE WILL ALSO BE THE POTENTIAL FOR
EMBEDDED THUNDER THURSDAY NIGHT THROUGH FRIDAY NIGHT AS ELEVATED
LAPSE RATES STEEPEN...AND HAVE CONTINUED THIS IN THE FORECAST.
CLEARING AND DRYING TAKES PLACE DOES EVENTUALLY TAKE PLACE
WEST TO EAST SATURDAY WITH HIGHS TEMPS WARMING BACK TO TOWARDS
SEASONABLE LEVELS OVER THE WEEKEND AND INTO EARLY NEXT WEEK.
JR
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 52 34 38 34 40 / 10 10 20 30 60
AUSTIN BERGSTROM INTL AIRPORT 52 35 38 34 40 / 10 10 20 30 60
NEW BRAUNFELS MUNI AIRPORT 54 36 38 34 39 / 10 10 20 30 50
BURNET MUNI AIRPORT 48 30 36 29 37 / 10 10 20 30 60
DEL RIO INTL AIRPORT 54 36 41 33 44 / 10 40 30 30 20
GEORGETOWN MUNI AIRPORT 49 32 36 31 38 / 10 10 20 30 60
HONDO MUNI AIRPORT 56 36 39 33 42 / 10 20 20 30 40
SAN MARCOS MUNI AIRPORT 53 35 38 34 40 / 10 10 20 30 60
LA GRANGE - FAYETTE REGIONAL 55 36 41 36 42 / 10 10 20 30 50
SAN ANTONIO INTL AIRPORT 55 36 39 35 41 / 10 10 20 30 50
STINSON MUNI AIRPORT 56 38 39 36 41 / 10 10 20 30 50
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR THE FOLLOWING
COUNTIES: ATASCOSA...BANDERA...BASTROP...BEXAR...BLANCO...BURNET...
CALDWELL...COMAL...DIMMIT...EDWARDS...FAYETTE...FRIO...GILLESPIE...
GONZALES...GUADALUPE...HAYS...KENDALL...KERR...KINNEY...LEE...
LLANO...MAVERICK...MEDINA...REAL...TRAVIS...UVALDE...VAL VERDE...
WILLIAMSON...WILSON...ZAVALA.
WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY MORNING
FOR THE FOLLOWING COUNTIES: BANDERA...BLANCO...BURNET...EDWARDS...
GILLESPIE...KENDALL...KERR...LLANO...REAL...VAL VERDE.
&&
$$
MESOSCALE/AVIATION...05
SYNOPTIC/GRIDS...76
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
613 AM CST TUE DEC 30 2014
.AVIATION...
LIFR/VLIFR VIS AND CIGS IN AUSTIN AND SAN ANTONIO THIS MORNING
WILL CONTINUE UNTIL MID-MORNING WHEN NORTHWESTERLY WINDS PICK UP.
THEN MVFR/IFR CIGS THROUGH THE REST OF THE TAF PERIOD. DRT WILL
DROP TO IFR SHORTLY AND STAY THAT WAY UNTIL AROUND 18Z. EXPECTING
PRECIPITATION WEDNESDAY MORNING AT DRT. HAVE NOT INCLUDED ANY
PRECIP IN AUSTIN OR SAN ANTONIO...BUT THERE IS A SLIGHT CHANCE FOR
RAIN. IF THERE IS ANY RAIN IT WILL DROP VIS TO MVFR.
&&
.PREV DISCUSSION... /ISSUED 523 AM CST TUE DEC 30 2014/
UPDATE...SECOND UPDATE TO EXPAND DENSE FOG ADVISORY FARTHER WEST
AND SOUTH BASED ON SATELLITE AND WEB CAM TRENDS. THIS ALSO LINES
UP WELL WITH HRRR EXPANSION OF FOG.
PREV DISCUSSION... /ISSUED 443 AM CST TUE DEC 30 2014/
UPDATE...QUICK UPDATE TO ISSUE DENSE FOG ADVISORY FOR I-35
CORRIDOR FROM COMAL TO WILLIAMSON COUNTY EASTWARD. THIS IS BASED ON
SEVERAL WEBCAMS AND OBS INDICATING DENSE FOG. THERE IS ALSO THE
POTENTIAL FOR PATCHY TO AREAS OF DENSE FOG SOUTH AND WEST OF THE
ADVISORY AREA THROUGH THE MORNING.
PREV DISCUSSION... /ISSUED 401 AM CST TUE DEC 30 2014/
SHORT TERM (TODAY THROUGH WEDNESDAY)...AREAS OF LOW STRATUS AND
FOG HAVE FORMED ACROSS EASTERN AREAS AS WELL AS ALONG THE RIO
GRANDE EARLY THIS MORNING. THE FOG AND CLOUDS WILL CONTINUE TO
EXPAND INTO THE I-35 CORRIDOR AND PORTIONS OF THE HILL COUNTRY
THROUGH THE MORNING HOURS.
THE MUCH ADVERTISED ARCTIC AIRMASS HAS MOVED THROUGH THE HILL
COUNTRY AND INTO WEST TEXAS. THE AIRMASS IN RELATIVELY DENSE
BEHIND A 1055MB HIGH ANALYZED UP IN MONTANA. THE AIRMASS WILL
GRADUALLY FILTER INTO SOUTH-CENTRAL TEXAS TODAY AND TONIGHT.
ISENTROPIC ASCENT ABOVE THE SHALLOW...COLD AIRMASS WELL DEVELOP
TONIGHT AND GRADUALLY STRENGTHEN WEDNESDAY AND WEDNESDAY NIGHT.
INITIALLY THICK CLOUDS WILL RESULT FROM THIS...WITH ONLY PATCHY
DRIZZLE AND PATCHY LIGHT RAIN DEVELOPING ACROSS THE WESTERN CWA
TONIGHT AND EXPANDING EAST ON WEDNESDAY. THE GFS CONTINUES TO BE
DRIER IN THE LOWEST LEVELS TODAY THROUGH WEDNESDAY...TAKING LONGER
TO MOISTEN. HOWEVER FORECAST SOUNDINGS FROM THE HRRR/ARW/NMM AS
WELL AS NAM12 ARE NOT QUITE AS AGGRESSIVE WITH THIS DRY LAYER AND
MOISTENS FASTER. HAVE FOLLOWED SLIGHTLY CLOSER TO THE LATTER. THIS
COULD POTENTIALLY RESULT IN PATCHY FREEZING DRIZZLE AND FREEZING
LIGHT RAIN ALONG AND NORTH OF A PANDALE TO LEAKY TO JOHNSON CITY
TO BURNET LINE EARLY WEDNESDAY MORNING. QPF AMOUNTS SHOULD BE VERY
LIGHT...AND GIVEN GROUND TEMPS AND PATCHY COVERAGE IMPACTS SHOULD
BE LIMITED TO ELEVATED SURFACES WITH MINIMAL TRAVEL IMPACTS.
ON WEDNESDAY VERY LITTLE DIURNAL TEMPERATURE RANGE IS EXPECTED...
WITH HIGHS ONLY CLIMBING INTO THE MID 30S ACROSS THE HILL COUNTRY
(WITH A FEW ISOLATED HILL COUNTRY SPOTS REMAINING IN THE LOW
30S)...UPPER 30S ALONG THE I-35 CORRIDOR AND LOW 40S ALONG THE RIO
GRANDE AS WELL AS FAR SOUTHERN/SOUTHEAST AREAS.
LONG TERM (WEDNESDAY NIGHT THROUGH MONDAY)...
FREEZING RAIN WITH TRAVEL IMPACTS POSSIBLE LATE NEW YEARS EVE
INTO NEW YEARS DAY ACROSS THE HILL COUNTRY. WINTER STORM WATCH POSTED...
THE UPPER LEVEL LOW ACROSS SOUTHERN CALIFORNIA IS FORECAST TO
MOVE EAST INTO ARIZONA NEW YEARS EVE NIGHT INTO NEW YEARS DAY. THE
ISENTROPIC UPGLIDE OVER THE COLD AIRMASS STRENGTHENS WEST TO EAST
DURING THIS TIME. SEVERAL MODELS HAVE BEEN INDICATING FOR A FEW
RUNS NOW A MID AND UPPER LEVEL SHORTWAVE IN THE SOUTHWEST FLOW
ALOFT MOVING OUT OF MEXICO AND INTO WEST-CENTRAL TEXAS AND THE
HILL COUNTRY LATE WEDNESDAY NIGHT AND THURSDAY. GFS AND ECMWF BOTH
SHOW ENHANCED BAND OF QPF CLIPPING THE HILL COUNTRY...ALONG WITH
SREF OUTPUT. CONFIDENCE CONTINUES TO GROW IN FREEZING RAIN EVENT
LATE WEDNESDAY NIGHT THROUGH MIDDAY THURSDAY ACROSS AT LEAST THE
HILL COUNTRY. THE WARM CLOUD LAYER DEPTH IS INCREASING DURING THIS
TIME...BUT CAN NOT COMPLETELY RULE OUT SLEET MIXING IN ACROSS THE
NORTHERN HILL COUNTRY AS WELL. GIVEN HOLIDAY TRAVEL SENSITIVITY...
AND AFTER COORDINATION WITH SURROUNDING WFOS...WE HAVE DECIDED TO
ISSUE A WINTER STORM WATCH FOR THE HILL COUNTRY...ALONG AND NORTH
OF A VAL VERDE TO BANDERA TO BURNET COUNTY LINE. IF TEMPS AND
ENHANCEMENT IN QPF VERIFY...THERE COULD BE A BAND ACROSS THE
NORTHERN HILL COUNTRY OF HIGHER ICE ACCUMULATION AMOUNTS.
FARTHER EAST ALONG THE I-35 CORRIDOR...TEMPERATURES WILL BE VERY
CLOSE TO FREEZING EARLY THURSDAY MORNING. ALTHOUGH THESE COUNTIES
ARE NOT CURRENTLY IN THE WATCH...THE FREEZING RAIN LINE IS
FORECAST TO REACH A HELOTES TO WIMBERLEY TO GEORGETOWN LINE. ANY
TRENDS DOWNWARD IN THE TEMP FORECAST...OR WET-BULB COOLING...COULD
PUSH THIS LINE TOWARDS THE AUSTIN AND NORTHERN SAN ANTONIO METRO
AREAS. THOSE WITH TRAVEL PLANS NEW YEARS EVE NIGHT INTO NEW YEARS
DAY ALONG THE INTERSTATE 35 CORRIDOR SHOULD CLOSELY MONITOR FOR
ANY FORECASTS UPDATES.
MODELS ARE SLIGHTLY SLOWER WITH HOW FAST THE UPPER LEVEL LOW
EJECTS OUT INTO THE PLAINS FROM RUNS A FEW DAYS AGO. THE UPPER
LEVEL LOW MOVES ACROSS SOUTHERN NEW MEXICO FRIDAY AND NORTHEAST
THROUGH WEST TEXAS FRIDAY NIGHT INTO SATURDAY MORNING. GOOD
CHANCES FOR RAIN WILL CONTINUE ACROSS THE REGION THURSDAY NIGHT
THROUGH FRIDAY NIGHT. THE WARM CLOUD LAYER CONTINUES TO WARM
FURTHER WITH SLIGHT MODIFICATION IN THE COLD AIRMASS BELOW. PRECIP
WILL REMAIN ALL LIQUID DURING THIS TIME (ALTHOUGH MAY HAVE TO
WATCH CLOSELY ACROSS FAR NORTHERN AREAS OF THE CWA THURSDAY
NIGHT). IN ADDITION...THERE WILL ALSO BE THE POTENTIAL FOR
EMBEDDED THUNDER THURSDAY NIGHT THROUGH FRIDAY NIGHT AS ELEVATED
LAPSE RATES STEEPEN...AND HAVE CONTINUED THIS IN THE FORECAST.
CLEARING AND DRYING TAKES PLACE DOES EVENTUALLY TAKE PLACE
WEST TO EAST SATURDAY WITH HIGHS TEMPS WARMING BACK TO TOWARDS
SEASONABLE LEVELS OVER THE WEEKEND AND INTO EARLY NEXT WEEK.
JR
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 52 34 38 34 40 / 10 10 20 30 60
AUSTIN BERGSTROM INTL AIRPORT 52 35 38 34 40 / 10 10 20 30 60
NEW BRAUNFELS MUNI AIRPORT 54 36 38 34 39 / 10 10 20 30 50
BURNET MUNI AIRPORT 48 30 36 29 37 / 10 10 20 30 60
DEL RIO INTL AIRPORT 54 36 41 33 44 / 10 40 30 30 20
GEORGETOWN MUNI AIRPORT 49 32 36 31 38 / 10 10 20 30 60
HONDO MUNI AIRPORT 56 36 39 33 42 / 10 20 20 30 40
SAN MARCOS MUNI AIRPORT 53 35 38 34 40 / 10 10 20 30 60
LA GRANGE - FAYETTE REGIONAL 55 36 41 36 42 / 10 10 20 30 50
SAN ANTONIO INTL AIRPORT 55 36 39 35 41 / 10 10 20 30 50
STINSON MUNI AIRPORT 56 38 39 36 41 / 10 10 20 30 50
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY MORNING
FOR THE FOLLOWING COUNTIES: BANDERA...BLANCO...BURNET...EDWARDS...
GILLESPIE...KENDALL...KERR...LLANO...REAL...VAL VERDE.
DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR THE FOLLOWING
COUNTIES: ATASCOSA...BANDERA...BASTROP...BEXAR...BLANCO...BURNET...
CALDWELL...COMAL...DIMMIT...FAYETTE...FRIO...GILLESPIE...GONZALES...
GUADALUPE...HAYS...KENDALL...KERR...LEE...LLANO...MEDINA...TRAVIS...
UVALDE...WILLIAMSON...WILSON...ZAVALA.
&&
$$
MESOSCALE/AVIATION...05
SYNOPTIC/GRIDS...76
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
544 AM CST TUE DEC 30 2014
.UPDATE...
KLBB 88D SHOWING THE EXPANSION OF VERY LIGHT REFLECTIVTY /ZERO TO
MINUS 15 DBZ/ BTWN 1000 AND 5000 FT AGL AND LOWERING WITH TIME.
THIS SHOULD BE THE PERIOD OF VERY LIGHT FLURRIES AND/OR FREEZING
DRIZZLE ASSOCIATED WITH FRONTOGENTICAL FORCING. PER THE HRRR THIS
PRECIP SHOULD SHIFT SWD WITH THE FORCING THROUGH THE MORNING.
EXPECTATION IS IT SHOULD REMAIN TOO LIGHT CAUSE MUCH IN THE WAY OF
DIFFICULTY THIS MORNING...BUT WILL CONTINUE TO MONITOR TRENDS.
&&
.AVIATION...
CIGS TO LOWER A BIT MORE DURING THE FIRST PART OF THE FCST PERIOD
BUT SHOULD REMAIN MVFR THEN REMAIN PRETTY STABLE THROUGH THE
REMAINDER OF THE PERIOD. ANTICIPATE SOME PERIODS OF LIGHT FREEZING
DRIZZLE AND/OR FLURRIES THROUGH THE FCST TIME AS WELL. GUSTY NNE
WINDS THROUGH MUCH OF THE DAY SHOULD RELAX TOWARD EVENING.
&&
.PREV DISCUSSION... /ISSUED 428 AM CST TUE DEC 30 2014/
SHORT TERM...
THE COLD FRONT IS NOW WELL INTO THE PERMIAN BASIN AND BIG COUNTRY
WITH MUCH COLDER AIR FILTERING IN BEHIND IT RATHER THAN SURGING AT
THIS POINT. WITH A GOOD STRATUS DECK NOW IN PLACE...ALTHOUGH
NOT TERRIBLY LOW AT ABOUT 2000 FT AGL...AND LOW LEVEL COLD ADVECTION
PERSISTING THROUGH THE DAY...TEMPS WILL HAVE TROUBLE MOVING OFF OF
MORNING LOWS. INDEED...WILL LIKELY SEE TEMPS FALL THROUGH ABOUT
MID-MORNING BEFORE SOME SLIGHT RECOVERY LATER IN THE DAY.
HOWEVER...MAIN FOCUS CONTINUES TO BE ON CHANCE FOR VERY LIGHT
PRECIPITATION TODAY AND TONIGHT AND POTENTIAL IMPACTS OF IT WITH
TEMPS IN THE TEENS AND 20S. THIS PRECIP EVENT CONTINUES TO LOOK
PRIMARILY ISENTROPIC DRIVEN WITH SOME MINOR CONTRIBUTION FROM
FRONTOGENETICAL FORCING EARLY ON. ISENTROPIC PROJECTIONS DEPICT LIFT
INITIALLY AT THE VERY TOP OF THE COLD AIR...PRIMARILY IN THE WARMER
AND DRIER MID LEVELS ABOVE IT. HOWEVER...AS THE COLD AIR DEEPENS
THROUGH THE DAY...SOME OF THIS COLD MOISTURE SHOULD BE TAPPED BY THE
ISENTROPIC LIFT TO PRODUCE SOME LIGHT PRECIP. BEST WINDOW FOR THIS
APPEARS TO BE BETWEEN 3 PM AND MIDNIGHT...AFTER WHICH ISENTROPIC
LIFT WEAKENS SIGNIFICANTLY. QUESTION THEN BECOMES PHASE OF THIS
PRECIPITATION. PROGGED SOUNDINGS SUPPORT EITHER FREEZING DRIZZLE OR
VERY LIGHT SNOW. COLDER LOW LEVELS ACROSS THE NORTH AND WEST MIGHT
END UP FAVORING FLURRIES TO A DUSTING OF SNOW WHILE FURTHER SOUTH
AND EAST FREEZING DRIZZLE LIKELY TO BE PREDOMINANT. HOW MUCH IS A
BIG QUESTION WITH SOUNDINGS SUGGESTING THE MODEL QPF OUTPUT IS
OVERDONE.
AS FOR POTENTIAL FOR ADVISORY...STILL SOME DETAILS TO WORK OUT SUCH
AS FLURRIES VS DRIZZLE AND TIMING OF ONSET OF PRECIP HEAVY AND/OR
WIDESPREAD ENOUGH TO BEGIN TO CAUSE TRAVEL ISSUES. SINCE CURRENT
EXPECTATION IS THE MORE SIGNIFICANT PART OF THE EVENT IS STILL 8-12
HOURS AWAY AND ANOTHER MODEL RUN AND 12Z UA ANALYSIS SHOULD HELP
NARROW DOWN THE DETAILS FURTHER...WILL DEFER ON THE ISSUANCE OF AN
ADVISORY ATTM.
LONG TERM...
AN UA DISTURBANCE ACROSS THE GREAT BASIN IS STILL PROGGED TO PINCH
OFF AND DIVE SSE TO ACROSS SRN CALI TOMORROW...AND ACROSS THE DESERT
SW ON THURSDAY. AS SUCH...FLOW ALOFT WILL EVOLVE FROM A BROAD
CYCLONIC FLOW TO SWRLY FLOW. IF THE ANTICIPATED TRACK OF THE SYSTEM
DOES NOT CHANGE...IT WILL MOVE DIRECTLY ACROSS THE SOUTHERN PLAINS
FRIDAY NIGHT THEN EXIT TO THE NE BY SATURDAY. THEREAFTER...DRY NW
FLOW ALOFT WILL PREVAIL.
TEMPS STRUGGLING TO GET OUT OF THE 20S WILL CHARACTERIZE WEDNESDAY
AS THE CAA USHERED IN BY LAST NIGHT/S COLD FRONTAL PASSAGE REMAINS
ENTRENCHED. FURTHERMORE...MAY ALSO EXPERIENCE A LINGERING FREEZING
DRIZZLE/WINTRY MIX...COURTESY OF MOISTENED ATMOSPHERIC LOW LEVELS
AND AN UPSLOPE SFC REGIME. THIS WINTRY MIX MAY BE HARD-PRESSED TO
REACH THE GROUND AS IT WILL HAVE TO FALL THROUGH RATHER DRY
MID-LEVELS...WHICH IS WHERE THE SLIVER OF UL SUPPORT IS MAXIMIZED.
ON THURSDAY DURING THE DAY...A SIMILAR SCENARIO TO WEDNESDAY WILL
PLAY OUT...WITH THE DIFFERENCE BEING PROGGED MODEL SOUNDINGS HINTING
AT A WARM TONGUE DEVELOPING IN THE MID-LEVELS...THUS SUGGESTING
MORE OF A FREEZING RAIN/WINTRY MIX OCCURRENCE. NONETHELESS...THE
BEST LIFT IS STILL MAXIMIZED WITHIN THE DRY MID-LEVELS AND HENCE LIGHT
PRECIP IS EXPECTED. BY THURSDAY NIGHT HOWEVER...MID-LEVELS ARE
SHOWN TO MOISTEN AS THE UA SYSTEM DRAWS NEAR. THE BEST UL SUPPORT
IS FINALLY TAPPING INTO ADEQUATE MOISTURE. MID-LEVEL MOISTENING
OCCURRING WITHIN THE DENDRITIC ZONE COULD PROMOTE A CHANCE OF
SNOW...PARTICULARY ACROSS THE HIGHER TERRAIN OF THE NWRN ZONES.
ELSEWHERE...FREEZING RAIN AND PERHAPS SLEET WILL BE COMMON...WITH
THE EXCEPTION OF THE FAR ROLLING PLAINS WHERE A MIX OF A COLD RAIN
AND FREEZING RAIN MAY OCCUR...GIVEN TEMPS WILL WARM TO SLIGHTLY
ABOVE FREEZING THERE /LOWER 30S ELSEWHERE/. TEMPS WILL WARMUP
FURTHER ON FRIDAY...INTO THE MIDDLE TO UPPER 30S ON THE CAPROCK
TO UPPER 30S TO LOWER 40S OFF THE CAPROCK...WHICH WILL AFFECT THE
PRECIP PHASE. COULD THEREFORE SEE MORE OF A RAIN AND SNOW MIX OR A
RAIN AND FREEZING RAIN MIX DEVELOP BY THE EVENING /THE NWRN ZONES
WILL BE THE EXCEPTION AS SOUNDING PROFILES SUGGEST LIGHT SNOW
THERE/.
LATE FRIDAY NIGHT-EARLY SATURDAY MORNING...LARGE SCALE ASCENT WILL
BE FLEETING AS THE SYSTEM COMMENCE TO EXIT THE REGION. PERHAPS SOME
LINGERING RAIN AND SNOW MIX WILL BE POSSIBLE ACROSS PORTIONS OF THE
ROLLING PLAINS EARLY SATURDAY MORNING. THEREAFTER...DRY NW FLOW
ALOFT WILL PREVAIL AND THE RETURN TO SRLY SFC FLOW EARLY NEXT
WEEK WILL AID IN PUSHING TEMPS BACK UP TO NEAR 50.
NOTE: ALTHOUGH THE WINTRY PRECIP IS EXPECTED TO BE LIGHT THIS
WEEK...IT COULD STILL POSE A THREAT FOR HAZARDOUS ROAD
CONDITIONS AS A THIN GLAZE OF ICE COULD FORM ACROSS OVERPASSES AND
BRIDGES IN PARTICULAR. AS YOU HEAD OUT TO ENJOY THE NEW YEAR
FESTIVITIES...CAUTION IS ADVISED. CHECK BACK TO STAY ALERT AND UP TO
DATE WITH ANY WEATHER CHANGES.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 20 11 22 17 32 / 30 40 20 10 20
TULIA 22 13 22 19 32 / 30 40 10 10 20
PLAINVIEW 23 14 23 19 32 / 30 40 10 10 20
LEVELLAND 24 16 24 19 32 / 40 50 20 20 20
LUBBOCK 25 16 25 20 32 / 40 50 20 20 20
DENVER CITY 27 18 25 20 33 / 40 50 20 20 30
BROWNFIELD 27 18 25 20 33 / 40 50 20 20 30
CHILDRESS 28 18 25 22 34 / 20 40 10 10 20
SPUR 28 18 25 22 33 / 30 50 20 20 30
ASPERMONT 30 20 27 24 36 / 20 40 20 20 30
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
07/29/07
AREA FORECAST DISCUSSION
NWS MIDLAND/ODESSA TX
541 AM CST Tue Dec 30 2014
.DISCUSSION...
&&
.AVIATION...
Strong front has moved through the region with a gusty N/NE wind
in its wake... gusts should continue through the day. Low clouds
have reached most TAF sites and will remain through the day with
low MVFR/IFR conditions. Expect a wintry precipitation to develop
with freezing rain... freezing drizzle... and sleet along with
some fog to reduce vsbys.
&&
.PREV DISCUSSION... /ISSUED 512 AM CST Tue Dec 30 2014/
DISCUSSION...As of 5:00 AM CST Tuesday...Sfc obs indc that the
Arctic Front has made it to the Trans Pecos...and continues to
surge south. Low clouds have quickly filled in behind the front
with low overcast past Wink per sfc obs and satl imagery.
Winter weather will be the rule into the New Year. Mild air will
override the cold low level airmass. With the lack of jet
dynamics isentropic lift will lead to periods of light freezing
rain and sleet right thru Wednesday aftn...and possibly into New
Years Day. The HRRR model is indc precipitation moving thru the
Permian Basin and Southeast New Mexico this morning and moving
south of the Pecos River by late morning. Temps will slowly fall
through the day with below freezing temps thru New Years Eve. Due
to the extended nature of this event and the substantial impacts
to holiday travel have upgraded the Winter Storm Watch to a Winter
Storm Warning. The warning will continue thru Wed aftn for West
Texas and Southeast New Mexico...except for the Presidio Valley
where temps could be a little warmer. Strong sfc pressure gradient
will lead to high winds thru Guadalupe Pass...the High Wind Watch
has been upgraded to a High Wind Warning continuing into Wednesday
morning. A combination of gusty winds and very cold temperatures
could lead to wind chill values in the single digits in the Plains
tonight...with dangerous wind chill values as low as -10F in the
Guadalupe Mtns.
An upper low over SoCal will move slowly east into Southeast New
Mexico Friday night. Light freezing rain and sleet could continue
into New Years morning. It is possible that the Winter Storm
Warning might need to be extended into New Years morning. Milder
air should change the precipitation to rain New Years aftn.
However...the ECMWF is showing a deeper cold airmass moving back
into the CWA bringing a chance of snow Thursday night...and a
chance of a rain/snow mix Friday and Friday night.
As the upper low moves east of the CWA...the upcoming weekend will
be dry but cool. Southwest flow sfc and aloft will bring dry
weather along with a warming trend the beginning of next week.
Strobin
&&
.MAF WATCHES/WARNINGS/ADVISORIES...
NM...WINTER STORM WARNING until 5 PM MST Wednesday FOR THE FOLLOWING
ZONES... Central Lea County...Eddy County Plains...
Guadalupe Mountains of Eddy County...Northern Lea County...
Southern Lea County.
TX...WINTER STORM WARNING until 6 PM CST /5 PM MST/ Wednesday FOR THE
FOLLOWING ZONES... Andrews...Big Bend Area...Borden...
Crane...Davis/Apache Mountains Area...Dawson...Ector...
Gaines...Glasscock...Guadalupe Mountains...Howard...
Loving...Marfa Plateau...Martin...Midland...Mitchell...
Pecos...Reagan...Reeves County and Upper Trans Pecos...
Scurry...Terrell...Upton...Van Horn and Highway 54
Corridor...Ward...Winkler.
HIGH WIND WARNING until 8 AM MST Wednesday FOR THE FOLLOWING
ZONES... Guadalupe Mountains.
&&
$$
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AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
523 AM CST TUE DEC 30 2014
.UPDATE...SECOND UPDATE TO EXPAND DENSE FOG ADVISORY FARTHER WEST
AND SOUTH BASED ON SATELLITE AND WEB CAM TRENDS. THIS ALSO LINES
UP WELL WITH HRRR EXPANSION OF FOG.
&&
.PREV DISCUSSION... /ISSUED 443 AM CST TUE DEC 30 2014/
UPDATE...QUICK UPDATE TO ISSUE DENSE FOG ADVISORY FOR I-35
CORRIDOR FROM COMAL TO WILLIMSON COUNTY EASTWARD. THIS IS BASED ON
SEVERAL WEBCAMS AND OBS INDICATING DENSE FOG. THERE IS ALSO THE
POTENTIAL FOR PATCHY TO AREAS OF DENSE FOG SOUTH AND WEST OF THE
ADVISORY AREA THROUGH THE MORNING.
PREV DISCUSSION... /ISSUED 401 AM CST TUE DEC 30 2014/
SHORT TERM (TODAY THROUGH WEDNESDAY)...AREAS OF LOW STRATUS AND
FOG HAVE FORMED ACROSS EASTERN AREAS AS WELL AS ALONG THE RIO
GRANDE EARLY THIS MORNING. THE FOG AND CLOUDS WILL CONTINUE TO
EXPAND INTO THE I-35 CORRIDOR AND PORTIONS OF THE HILL COUNTRY
THROUGH THE MORNING HOURS.
THE MUCH ADVERTISED ARCTIC AIRMASS HAS MOVED THROUGH THE HILL
COUNTRY AND INTO WEST TEXAS. THE AIRMASS IN RELATIVELY DENSE
BEHIND A 1055MB HIGH ANALYZED UP IN MONTANA. THE AIRMASS WILL
GRADUALLY FILTER INTO SOUTH-CENTRAL TEXAS TODAY AND TONIGHT.
ISENTROPIC ASCENT ABOVE THE SHALLOW...COLD AIRMASS WELL DEVELOP
TONIGHT AND GRADUALLY STRENGTHEN WEDNESDAY AND WEDNESDAY NIGHT.
INITIALLY THICK CLOUDS WILL RESULT FROM THIS...WITH ONLY PATCHY
DRIZZLE AND PATCHY LIGHT RAIN DEVELOPING ACROSS THE WESTERN CWA
TONIGHT AND EXPANDING EAST ON WEDNESDAY. THE GFS CONTINUES TO BE
DRIER IN THE LOWEST LEVELS TODAY THROUGH WEDNESDAY...TAKING LONGER
TO MOISTEN. HOWEVER FORECAST SOUNDINGS FROM THE HRRR/ARW/NMM AS
WELL AS NAM12 ARE NOT QUITE AS AGGRESSIVE WITH THIS DRY LAYER AND
MOISTENS FASTER. HAVE FOLLOWED SLIGHTLY CLOSER TO THE LATTER. THIS
COULD POTENTIALLY RESULT IN PATCHY FREEZING DRIZZLE AND FREEZING
LIGHT RAIN ALONG AND NORTH OF A PANDALE TO LEAKY TO JOHNSON CITY
TO BURNET LINE EARLY WEDNESDAY MORNING. QPF AMOUNTS SHOULD BE VERY
LIGHT...AND GIVEN GROUND TEMPS AND PATCHY COVERAGE IMPACTS SHOULD
BE LIMITED TO ELEVATED SURFACES WITH MINIMAL TRAVEL IMPACTS.
ON WEDNESDAY VERY LITTLE DIURNAL TEMPERATURE RANGE IS EXPECTED...
WITH HIGHS ONLY CLIMBING INTO THE MID 30S ACROSS THE HILL COUNTRY
(WITH A FEW ISOLATED HILL COUNTRY SPOTS REMAINING IN THE LOW
30S)...UPPER 30S ALONG THE I-35 CORRIDOR AND LOW 40S ALONG THE RIO
GRANDE AS WELL AS FAR SOUTHERN/SOUTHEAST AREAS.
LONG TERM (WEDNESDAY NIGHT THROUGH MONDAY)...
.FREEZING RAIN WITH TRAVEL IMPACTS POSSIBLE LATE NEW YEARS EVE
INTO NEW YEARS DAY ACROSS THE HILL COUNTRY. WINTER STORM WATCH POSTED...
THE UPPER LEVEL LOW ACROSS SOUTHERN CALIFORNIA IS FORECAST TO
MOVE EAST INTO ARIZONA NEW YEARS EVE NIGHT INTO NEW YEARS DAY. THE
ISENTROPIC UPGLIDE OVER THE COLD AIRMASS STRENGTHENS WEST TO EAST
DURING THIS TIME. SEVERAL MODELS HAVE BEEN INDICATING FOR A FEW
RUNS NOW A MID AND UPPER LEVEL SHORTWAVE IN THE SOUTHWEST FLOW
ALOFT MOVING OUT OF MEXICO AND INTO WEST-CENTRAL TEXAS AND THE
HILL COUNTRY LATE WEDNESDAY NIGHT AND THURSDAY. GFS AND ECMWF BOTH
SHOW ENHANCED BAND OF QPF CLIPPING THE HILL COUNTRY...ALONG WITH
SREF OUTPUT. CONFIDENCE CONTINUES TO GROW IN FREEZING RAIN EVENT
LATE WEDNESDAY NIGHT THROUGH MIDDAY THURSDAY ACROSS AT LEAST THE
HILL COUNTRY. THE WARM CLOUD LAYER DEPTH IS INCREASING DURING THIS
TIME...BUT CAN NOT COMPLETELY RULE OUT SLEET MIXING IN ACROSS THE
NORTHERN HILL COUNTRY AS WELL. GIVEN HOLIDAY TRAVEL SENSITIVITY...
AND AFTER COORDINATION WITH SURROUNDING WFOS...WE HAVE DECIDED TO
ISSUE A WINTER STORM WATCH FOR THE HILL COUNTRY...ALONG AND NORTH
OF A VAL VERDE TO BANDERA TO BURNET COUNTY LINE. IF TEMPS AND
ENHANCEMENT IN QPF VERIFY...THERE COULD BE A BAND ACROSS THE
NORTHERN HILL COUNTRY OF HIGHER ICE ACCUMULATION AMOUNTS.
FARTHER EAST ALONG THE I-35 CORRIDOR...TEMPERATURES WILL BE VERY
CLOSE TO FREEZING EARLY THURSDAY MORNING. ALTHOUGH THESE COUNTIES
ARE NOT CURRENTLY IN THE WATCH...THE FREEZING RAIN LINE IS
FORECAST TO REACH A HELOTES TO WIMBERLY TO GEORGETOWN LINE. ANY
TRENDS DOWNWARD IN THE TEMP FORECAST...OR WET-BULB COOLING...COULD
PUSH THIS LINE TOWARDS THE AUSTIN AND NORTHERN SAN ANTONIO METRO
AREAS. THOSE WITH TRAVEL PLANS NEW YEARS EVE NIGHT INTO NEW YEARS
DAY ALONG THE INTERSTATE 35 CORRIDOR SHOULD CLOSELY MONITOR FOR
ANY FORECASTS UPDATES.
MODELS ARE SLIGHTLY SLOWER WITH HOW FAST THE UPPER LEVEL LOW
EJECTS OUT INTO THE PLAINS FROM RUNS A FEW DAYS AGO. THE UPPER
LEVEL LOW MOVES ACROSS SOUTHERN NEW MEXICO FRIDAY AND NORTHEAST
THROUGH WEST TEXAS FRIDAY NIGHT INTO SATURDAY MORNING. GOOD
CHANCES FOR RAIN WILL CONTINUE ACROSS THE REGION THURSDAY NIGHT
THROUGH FRIDAY NIGHT. THE WARM CLOUD LAYER CONTINUES TO WARM
FURTHER WITH SLIGHT MODIFICATION IN THE COLD AIRMASS BELOW. PRECIP
WILL REMAIN ALL LIQUID DURING THIS TIME (ALTHOUGH MAY HAVE TO
WATCH CLOSELY ACROSS FAR NORTHERN AREAS OF THE CWA THURSDAY
NIGHT). IN ADDITION...THERE WILL ALSO BE THE POTENTIAL FOR
EMBEDDED THUNDER THURSDAY NIGHT THROUGH FRIDAY NIGHT AS ELEVATED
LAPSE RATES STEEPEN...AND HAVE CONTINUED THIS IN THE FORECAST.
CLEARING AND DRYING TAKES PLACE DOES EVENTUALLY TAKE PLACE
WEST TO EAST SATURDAY WITH HIGHS TEMPS WARMING BACK TO TOWARDS
SEASONABLE LEVELS OVER THE WEEKEND AND INTO EARLY NEXT WEEK.
JR
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 52 34 38 34 40 / 10 10 20 30 60
AUSTIN BERGSTROM INTL AIRPORT 52 35 38 34 40 / 10 10 20 30 60
NEW BRAUNFELS MUNI AIRPORT 54 36 38 34 39 / 10 10 20 30 50
BURNET MUNI AIRPORT 48 30 36 29 37 / 10 10 20 30 60
DEL RIO INTL AIRPORT 54 36 41 33 44 / 10 40 30 30 20
GEORGETOWN MUNI AIRPORT 49 32 36 31 38 / 10 10 20 30 60
HONDO MUNI AIRPORT 56 36 39 33 42 / 10 20 20 30 40
SAN MARCOS MUNI AIRPORT 53 35 38 34 40 / 10 10 20 30 60
LA GRANGE - FAYETTE REGIONAL 55 36 41 36 42 / 10 10 20 30 50
SAN ANTONIO INTL AIRPORT 55 36 39 35 41 / 10 10 20 30 50
STINSON MUNI AIRPORT 56 38 39 36 41 / 10 10 20 30 50
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY MORNING
FOR THE FOLLOWING COUNTIES: BANDERA...BLANCO...BURNET...EDWARDS...
GILLESPIE...KENDALL...KERR...LLANO...REAL...VAL VERDE.
DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR THE FOLLOWING
COUNTIES: ATASCOSA...BANDERA...BASTROP...BEXAR...BLANCO...BURNET...
CALDWELL...COMAL...DIMMIT...FAYETTE...FRIO...GILLESPIE...GONZALES...
GUADALUPE...HAYS...KENDALL...KERR...LEE...LLANO...MEDINA...TRAVIS...
UVALDE...WILLIAMSON...WILSON...ZAVALA.
&&
$$
MESOSCALE/AVIATION...05
SYNOPTIC/GRIDS...76
AREA FORECAST DISCUSSION
NWS MIDLAND/ODESSA TX
512 AM CST Tue Dec 30 2014
.DISCUSSION...As of 5:00 AM CST Tuesday...Sfc obs indc that the
Arctic Front has made it to the Trans Pecos...and continues to
surge south. Low clouds have quickly filled in behind the front
with low overcast past Wink per sfc obs and satl imagery.
Winter weather will be the rule into the New Year. Mild air will
override the cold low level airmass. With the lack of jet
dynamics isentropic lift will lead to periods of light freezing
rain and sleet right thru Wednesday aftn...and possibly into New
Years Day. The HRRR model is indc precipitation moving thru the
Permian Basin and Southeast New Mexico this morning and moving
south of the Pecos River by late morning. Temps will slowly fall
through the day with below freezing temps thru New Years Eve. Due
to the extended nature of this event and the substantial impacts
to holiday travel have upgraded the Winter Storm Watch to a Winter
Storm Warning. The warning will continue thru Wed aftn for West
Texas and Southeast New Mexico...except for the Presidio Valley
where temps could be a little warmer. Strong sfc pressure gradient
will lead to high winds thru Guadalupe Pass...the High Wind Watch
has been upgraded to a High Wind Warning continuing into Wednesday
morning. A combination of gusty winds and very cold temperatures
could lead to wind chill values in the single digits in the Plains
tonight...with dangerous wind chill values as low as -10F in the
Guadalupe Mtns.
An upper low over SoCal will move slowly east into Southeast New
Mexico Friday night. Light freezing rain and sleet could continue
into New Years morning. It is possible that the Winter Storm
Warning might need to be extended into New Years morning. Milder
air should change the precipitation to rain New Years aftn.
However...the ECMWF is showing a deeper cold airmass moving back
into the CWA bringing a chance of snow Thursday night...and a
chance of a rain/snow mix Friday and Friday night.
As the upper low moves east of the CWA...the upcoming weekend will
be dry but cool. Southwest flow sfc and aloft will bring dry
weather along with a warming trend the beginning of next week.
Strobin
&&
.PRELIMINARY POINT TEMPS/POPS...
ANDREWS TX 29 20 24 22 / 60 60 50 30
BIG SPRING TX 31 20 24 24 / 60 60 50 30
CARLSBAD NM 31 23 25 23 / 40 60 50 30
DRYDEN TX 41 32 32 29 / 50 60 50 20
FORT STOCKTON TX 32 20 29 25 / 50 60 60 20
GUADALUPE PASS TX 26 14 21 19 / 40 50 60 20
HOBBS NM 29 21 24 21 / 60 60 50 30
MARFA TX 37 19 31 22 / 30 40 50 20
MIDLAND INTL AIRPORT TX 30 19 25 23 / 60 60 50 30
ODESSA TX 29 20 25 23 / 60 60 50 30
WINK TX 32 28 29 26 / 40 60 50 20
&&
.MAF WATCHES/WARNINGS/ADVISORIES...
NM...WINTER STORM WARNING until 5 PM MST Wednesday FOR THE FOLLOWING
ZONES... Central Lea County...Eddy County Plains...
Guadalupe Mountains of Eddy County...Northern Lea County...
Southern Lea County.
TX...WINTER STORM WARNING until 6 PM CST /5 PM MST/ Wednesday FOR THE
FOLLOWING ZONES... Andrews...Big Bend Area...Borden...
Crane...Davis/Apache Mountains Area...Dawson...Ector...
Gaines...Glasscock...Guadalupe Mountains...Howard...
Loving...Marfa Plateau...Martin...Midland...Mitchell...
Pecos...Reagan...Reeves County and Upper Trans Pecos...
Scurry...Terrell...Upton...Van Horn and Highway 54
Corridor...Ward...Winkler.
HIGH WIND WARNING until 8 AM MST Wednesday FOR THE FOLLOWING
ZONES... Guadalupe Mountains.
&&
$$
72/33
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HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1152 PM EST MON DEC 29 2014
.SYNOPSIS...
COLD SURFACE HIGH PRESSURE WILL CONTINUE TO WEDGE DOWN FROM THE
NORTH ALONG THE APPALACHIANS TONIGHT WHILE A WEAK UPPER LEVEL
DISTURBANCE IS EXPECTED TO PASS FROM WEST TO EAST ACROSS THE AREA
TONIGHT THROUGH EARLY TUESDAY. VERY LIGHT PRECIPITATION ASSOCIATED
WITH THIS FEATURE IS EXPECTED TO CHANGE OVER TO SNOW ACROSS THE
NORTHERN PORTION OF THE REGION...WITH ACCUMULATIONS OF AN INCH OR
LESS...MAINLY ALONG AND NORTH OF U.S. 460. DRY BUT CONTINUED COLD
HIGH PRESSURE WILL BEGIN TO PUSH IN FROM THE WEST LATER TUESDAY
AND LAST UNTIL LATE IN THE WEEK.
&&
.NEAR TERM /THROUGH TUESDAY/...
AS OF 635 PM EST MONDAY...
MADE A FEW MINOR ADJUSTMENTS TO EXISTING SET OF GRIDS TO BUMP UP
PROBABILITY OF PRECIPITATION TO ACCOUNT FOR WIDESPREAD RAIN AND
DRIZZLE NOW FALLING ACROSS MUCH OF THE NEW RIVER VALLEY NORTH
TOWARD THE ALLEGHANY HIGHLANDS. DESPITE AREAL EXTENT OF
PRECIPITATION...AMOUNTS CONTINUE TO BE LIGHT...GENERALLY ONLY
AROUND 0.01 INCH/PER HOUR.
LATEST UPPER-AIR SOUNDING...RELEASED ABOUT 30 MINUTES AGO...SHOWS
LOWEST 3K FEET AGL STILL ABOVE FREEZING AND NEARLY SATURATED...SO
IT WILL TAKE MUCH OF THE EVENING...PERHAPS INTO THE EARLY MORNING
HOURS...TO DRIVE SNOW LEVELS DOWN FROM HIGHEST RIDGES TO MOUNTAIN
VALLEY AREAS...CONSISTENT WITH PREVIOUS FORECAST THINKING.
THEREFORE...SNOWFALL TOTALS STILL NOT EXPECTED TO BECOME
PROBLEMATIC AS THE NIGHT PROGRESSES...ESPECIALLY CONSIDERING
CURRENT WARM GROUND CONDITIONS AND VERY LIGHT FALL RATES.
ALSO MADE A FEW TWEAKS TO HOURLY TEMPS/DEW POINT GRIDS TO REFLECT
LATEST MESONET OBSERVATIONS...OTHERWISE REST OF FORECAST FOR
TONIGHT STILL LOOKS RIGHT ON TARGET.
AS OF 350 PM EST MONDAY...
TRICKY FCST OVERNIGHT IN REGARDS TO THE AMOUNTS AND LOCATIONS OF
VERY LIGHT PCPN AS A WEAK UPPER WAVE PASSES OVER THE DEEPENING
COLD AIR DAMMING WEDGE AS COLD SFC HIGH PRESSURE SPILLS DOWN FROM
THE NORTH. MODEL GUIDANCE ALL QUITE DIFFERENT WITH MAIN
OPERATIONAL NCEP MODELS TRENDING UPWARD SOMEWHAT WITH AS MUCH AS A
QUARTER TO TWO THIRDS OF AN INCH LIQUID EQUIV...MAINLY OVER THE
WESTERN PORTIONS. EVEN ORIGINALLY DRIER GFS NOW AS MUCH AS FOUR
TENTHS OF AN INCH OVER THE ALLEGHANY HIGHLANDS. MEANWHILE
CONVECTIVE-ALLOWING MODELS GENERALLY LESS THAN TWO TENTHS OF AN
INCH. AM LEANING ON THE LIGHT SIDE OF THE QPF OPTIONS...MORE IN
LINE WITH IDEA OF MOST OF THE HRRR RUNS...AND POSSIBILITY THAT
MORE OF THE PCPN ACTUALLY ENDS UP BACK ACROSS THE FOOTHILLS AND
PIEDMONT AGAIN. AM LEAVING SOME VERY LOW LIKELY POPS FOR TONIGHT
ACROSS PARTS OF THE MOUNTAINS...WITH HIGHER CHANCE POPS NOW ACROSS
THE FOOTHILLS. THE ISSUE OF MOISTURE DEPTH IS STILL CONCERN AS
WELL...AND WHILE I DID NOT INCLUDE ANY DRIZZLE IN THE
GRIDS...THERE COULD VERY WELL BE PERIODS OF TIME AND PORTIONS OF
THE AREA WHERE WE SEE MORE DRIZZLE DUE TO LACK OF ICE CRYSTAL
GROWTH ALOFT. THIS WOULD CUT DOWN ON ANY OF THE ALREADY LIGHT SNOW
ACCUMS IF AND WHERE THIS HAPPENS. WARM NOSE DOES NOT SEEM TO BE
PRESENT IN ANY MODEL SOUNDINGS...SO GOING WITH EITHER RAIN OR
SNOW...AND SO SFC TEMPS WILL BE THE KEY TO THAT CHANGEOVER. AS FAR
AS THE TEMPS GO...ALREADY GETTING COLDER THIS AFTERNOON THAN WE
EARLIER ANTICIPATED...AND SOME HIGHER ELEVATIONS HAVE REPORTS SOME
VERY LIGHT SNOW. THUS LOWERED TEMPS THROUGH EVENING AND OVERNIGHT
A FEW DEGREES FROM PREVIOUS FORECAST WHERE WEDGE IS EXPECTED TO BE
THE STRONGEST...AND THIS RESULTS IN A SLIGHTLY EARLIER CHANGEOVER
FROM LIGHT RAIN TO LIGHT SNOW...BUT EXCEPT FOR HIGHER
ELEVATIONS...THIS WILL STILL BE AFTER MIDNIGHT.
BOTTOM LINE IS ONLY VERY LIGHT AMOUNTS OF SNOW ACCUM
EXPECTED LATE TONIGHT AND IN THE EARLY MORNING HOURS TUESDAY...AND
IT WILL LIKELY HAVE TROUBLE STICKING AS WELL EXCEPT FOR HIGHEST
ELEVATIONS. HAVE DUSTING TO LESS THAN AN INCH GENERALLY NORTH OF
U.S. 460...AND DOWN THE BLUE RIDGE TO NEAR MEADOWS OF DAN. MAYBE
AN INCH TO ALMOST TWO ALONG HIGHEST RIDGES OF ALLEGHANY HIGHLANDS
AND ALONG BLUE RIDGE PARKWAY NORTH OF PEAKS OF OTTER. MOST ROADS
NOT EXPECTED TO SEE ANY ACCUMULATION.
ANY LINGERING PCPN EVAPORATES QUICKLY BY MIDDAY TUESDAY AS SHORT
WAVE PASSES BY AND DRIER AIR FROM NORTH CONTINUES TO FILTER IN.
WESTERLY FLOW AT RIDGE TOP LEVEL DEVELOPS BUT VERY WEAK FLOW AND
LITTLE MOISTURE TO WORK WITH SO NO ISSUES WITH ANY UPSLOPE SNOW
SHOWERS IN FAR WEST IT APPEARS. MAX TEMPS MAY BE TRICKY WITH SOME
SUNSHINE LATE IN THE DAY...BUT THIS COULD BE TOO LATE FOR LOW SUN
ANGLE TO HAVE MUCH IMPACT...SO FOR NOW GOING ON COLD SIDE OF
GUIDANCE WITH ONLY ABOUT A 5-7 DEGREE RISE FROM OVERNIGHT LOWS.
ABOVE FREEZING BY LATE MORNING SO ANY MINOR AMOUNTS OF SNOW THAT
DOES FALL WILL BE GONE BY NOON MOST LIKELY.
FINALLY...COLD WEDGE WILL KEEP SOME AREAS OF FOG AND LOW CEILINGS
AROUND...MOST ESPECIALLY NEAR THE BLUE RIDGE...BUT ALSO SOME OF
THE MTN VALLEYS AS WELL...SO BLANKED THE FOOTHILLS AND WESTWARD
WITH PATCHY FOG THROUGH TOMORROW MORNING IN THE FORECAST GRIDS BUT THIS
MAY LINGER THROUGH MUCH OF THE DAY IN SPOTS UNTIL THE WEAK WESTERLY
FLOW CAN PUSH EAST.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
AS OF 200 PM EST MONDAY...
A LARGE AREA OF HIGH PRESSURE WILL BUILD SOUTH FROM THE ROCKIES LATE
TUESDAY...THEN INTO THE SOUTHEAST U.S. BY THURSDAY EVENING KEEPING
DRY WEATHER FOR OUR AREA DURING THIS PORTION OF THE FORECAST.
ADJUSTED TEMPS DOWN A FEW DEGREES WEDNESDAY MORNING AND WEDNESDAY
AFTERNOON UNDER GOOD COLD AIR ADVECTION. BY THURSDAY MORNING
MODELS ARE IN GOOD AGREEMENT THAT SFC HIGH NOSES INTO OUR
AREA ALLOWING VALLEY WINDS TO DIMINISH. THIS COMBINED WITH THE
DRY AIR MASS IN PLACE SHOULD ALLOW TEMPS TO DROP BELOW GUIDANCE
VALUES. THE EXCEPTION WILL BE ON THE RIDGETOPS WHERE 850MB WINDS
WILL KEEP TEMPS WARMER.
HEIGHTS RISE ON THURSDAY AS AN UPPER RIDGE BEGINS TO BUILD IN THE
CENTRAL U.S. IN ADVANCE OF A SOUTHWEST U.S. UPPER LOW.
THIS...COMBINED WITH DOWNSLOPING WINDS...SHOULD ALLOW FOR A NICE
RECOVERY IN TEMPS THURSDAY. WENT A DEGREE OR TWO ABOVE GUIDANCE FOR
HIGHS.
ONLY OTHER CHANGE TO THE FORECAST WAS TO INCREASE THE WINDS ABOVE
3500 FEET WEDNESDAY AND THURSDAY AS A SWIFT MOVING NORTHERN STREAM
SHORTWAVE PASSES THROUGH THE EASTERN GREAT LAKES THROUGH NEW ENGLAND
DURING THIS TIME.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 235 PM EST MONDAY...
DRY AND SEASONABLY COOL WEATHER IS EXPECTED OVER THE BLACKSBURG
FORECAST AREA FRIDAY MORNING AS A WEAK SHORT WAVE IN NORTHERN STREAM
SCOOTS EAST THROUGH NEW ENGLAND...WITH COOL HIGH PRESSURE BUILDING
SOUTHWESTWARD IN ITS WAKE.
HOWEVER...MUCH OF THE REST OF THE LONG TERM FORECAST FROM FRIDAY
AFTERNOON INTO MONDAY APPEARS TO BE MUCH MORE UNCERTAIN...WITH
SIGNIFICANT AND PERSISTENT DISPARITY EXISTING BETWEEN THE LONGER-
TERM MODELS IN REFLECTING STRENGTH AND PLACEMENT OF NORTHERN
STREAM...AND ITS INFLUENCE ON SOUTHERN STREAM CLOSED LOW SOUTH OF
THE FOUR CORNERS AREA ON FRIDAY AFTERNOON THAT IS FORECAST TO
GRADUALLY LIFT NORTHEAST AND FILL AS IT PROGRESSES FROM THE SOUTHERN
PLAINS UP THROUGH THE OHIO VALLEY OVER THE WEEKEND.
ECMWF MAINTAINS A MORE PERSISTENT CLOSED UPPER LOW THAT IS MUCH LESS
AMPLIFIED...YET LESS PROGRESSIVE AND FURTHER SOUTH...RESULTING IN
INCREASING ISENTROPIC LIFT AND RAIN MOVING INTO AT LEAST THE
SOUTHWESTERN HALF OF THE BLACKSBURG FORECAST AREA BY/DURING FRIDAY
AFTERNOON...BUT NOT ENDING UNTIL PASSAGE OF OPENING/WEAKENING UPPER
TROF ON SUNDAY NIGHT.
GFS...WHICH REFLECTS A MORE AMPLIFIED...YET EVENTUALLY MORE
PROGRESSIVE AND NORTHERN SYSTEM PLACEMENT...HOLDS BACK RAIN SHIELD
UNTIL SATURDAY DUE TO INFLUENCE OF LARGER AND STRONGER DRY SURFACE
HIGH PRESSURE SYSTEM OVER NEW ENGLAND. GFS ALSO THE COLDER OF THE
LONGER RANGE SOLUTIONS...SINCE STRONGER SURFACE RIDGE TO NORTHEAST
WOULD LOCK COOL-WEDGE IN PLACE OVER THE BLACKSBURG FORECAST AREA.
HOWEVER...BEING MORE PROGRESSIVE...RAIN EVENT ENDS A BIT EARLIER
THAN ECMWF SOLUTION...ON SUNDAY AFTERNOON WITH PASSAGE OF UPPER
TROF...BUT WITH PERHAPS SOME COLD ADVECTION UPSLOPE PRECIPITATION
CONTINUING ACROSS THE WESTERN FLANKS OF THE APPALACHIANS UNTIL
AROUND DAYBREAK MONDAY.
BOTH MODELS HAVE BEEN INCONSISTENT IN TIMING AND PLACEMENT OF SYSTEM
THOUGH THIS TIME FRAME FOR AT LEAST THE PAST SEVERAL
RUNS...WHICH IS NOT ALL THAT SURPRISING CONSIDERING ACTIVE
NORTHERN STREAM CLASHING WITH INITIALLY CLOSED AND STAGNANT
SOUTHERN STREAM SYSTEM...SO MODEL BLEND/ENSEMBLE APPROACH BEST TO
APPLY FOR LONG TERM FORECAST UNTIL CONFIDENCE INCREASES IN MOVING
TOWARD ANY PARTICULAR SOLUTION.
NEITHER MODEL INDICATING THAT THICKNESSES WILL BE ESPECIALLY
CRITICAL FOR P-TYPE ISSUES...MEANING A MAINLY WET RATHER THAN WHITE
FORECAST OVER THE WEEKEND. HOWEVER...IF COLDER GFS SOLUTION
VERIFIES...THICKNESSES MAY BE CLOSE ENOUGH TO CRITICAL VALUES NORTH
OF HIGHWAY 64 TO WARRANT AT LEAST A NOMINAL INSERTION OF A P-TYPE
MIX DURING TIME OF PRECIPITATION ONSET...AND PERHAPS FOLLOWING
PASSAGE OF MAIN SYSTEM IN THE NORTHWESTERN MOUNTAINS ON SUNDAY NIGHT
PROVIDED THAT POST FRONTAL COLD ADVECTION IS SUFFICIENTLY STRONG.
REGARDLESS OF TIMING AND PLACEMENT DIFFERENCES...ALL LONGER RANGE
MODELS INDICATE THAT MONDAY WILL BE DRY FOLLOWING PASSAGE OF THE
MAIN UPPER SYSTEM...WITH ANY ADDITION SOUTHERN STREAM ENERGY LIKELY
TO BE DEFLECTED TO OUR SOUTH AS NORTHERN STREAM TROFING GRADUALLY
STRENGTHENS AND AMPLIFIES FROM THE UPPER GREAT LAKES EAST INTO THE
NORTHEASTERN PORTION OF THE NATION FROM MONDAY INTO THE MID WEEK
PERIOD.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 1150 PM EST MONDAY...
IFR TO LIFR CONDITIONS EXPECTED TO CONTINUE AT ALL AIRPORTS
THROUGH AT LEAST TONIGHT...AND FOR WESTERN AIRPORTS EVEN INTO
EARLY PART OF TUESDAY...UNDER THE INFLUENCE OF COLD AIR DAMMING
WHICH IS ONLY STRENGTHENING WITH TIME. ALL AIRPORTS EXCEPT FOR KDAN
SHOULD SEE SOME VERY LIGHT RAIN CHANGE TO LIGHT SNOW
OVERNIGHT...BUT NOT EXPECTED TO STICK MUCH AT ALL EXCEPT FOR THE
HIGHER ELEVATION AIRPORTS SUCH AS KLWB...AND KBCB. NOT SURE IT
WILL BE COLD ENOUGH TO REALLY ACCUMULATE AT KBLF AND KROA OR KLYH.
KDAN LIKELY WILL NOT EVEN SEE CHANGEOVER. IN ANY CASE...SNOW
AMOUNTS WOULD ONLY APPROACH AN INCH IN THE WORSE-CASE SCENARIO.
LOW CONFIDENCE FOR WHEN CONDITIONS MAY BEGIN TO BREAK OUT AND
LIFT ON TUESDAY. MORE CONFIDENT THAT KROA...KLYH AND KDAN WILL
IMPROVE TO VFR BY TUESDAY AFTERNOON AS DRIER AIR CONTINUES TO
FILTER DOWN FROM NORTH. CLEARING WILL CONTINUE IN THE AFTERNOON
AND EVENING. EVEN MOUNTAIN TAF SITES WILL IMPROVE TO VFR.
EXTENDED DISCUSSION...
A LARGE AREA OF HIGH PRESSURE WILL START TO NOSE INTO THE AREA
FROM THE WEST LATER TUESDAY INTO WEDNESDAY. VFR WILL THEN
PREVAIL THROUGH AT LEAST THURSDAY
CONDITIONS DETERIORATE THE WEEKEND. THE NEXT LOW PRESSURE SYSTEM
TO AFFECT THE AREA WILL COME FROM THE SOUTHWEST..DEVELOPING ALONG
THE TEXAS GULF COAST FRIDAY...THEN MOVING NORTHEAST ACROSS THE MID
ATLANTIC REGION FOR THE WEEKEND. THIS SYSTEM LOOKS LIKE IT WILL
PRODUCE A MULTI-DAY PERIOD OF SUB-VFR CONDITIONS...BEGINNING AS
EARLY AS FRIDAY NIGHT...AND LINGERING THROUGH SUNDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...SK
NEAR TERM...SK/WERT
SHORT TERM...PH
LONG TERM...WERT
AVIATION...AMS/WERT
AREA FORECAST DISCUSSION
NWS TUCSON AZ
945 PM MST WED DEC 31 2014
.SYNOPSIS...RAIN AND SNOW WILL CONTINUE ACROSS MUCH OF THE AREA INTO
THURSDAY. SNOW LEVELS WILL FALL TO THE VALLEY FLOORS IN SOME
LOCATIONS TONIGHT. ELEVATIONS ABOVE 4000 FEET CAN EXPECT
ACCUMULATING SNOW BY THURSDAY MORNING WITH SIGNIFICANT SNOW IN THE
MOUNTAINS. A SECONDARY DISTURBANCE WILL BRING A FEW SNOW SHOWERS
THURSDAY NIGHT INTO FRIDAY MORNING. A HARD FREEZE IS LIKELY FOR THE
TUCSON METRO AREA THURSDAY NIGHT AND PERHAPS AGAIN FRIDAY NIGHT. DRY
CONDITIONS WITH A WARMING TREND WILL OCCUR THIS WEEKEND AND INTO
NEXT WEEK.
&&
.DISCUSSION...KEMX WSR-88D CONTINUES TO INDICATE NUMEROUS MAINLY
30-35 DBZ ECHOES ACROSS MUCH OF PIMA/SRN PINAL/SANTA CRUZ/FAR WRN
COCHISE COUNTY VALID 0440Z. THESE PRECIP ECHOES WERE MOVING NEWD
AROUND 10-15 KTS. BASED ON VARIOUS OBSERVATIONS...THE BEST ESTIMATE
FOR SNOW LEVELS IN THE FOOTHILLS ADJACENT TUCSON IS 3000-3500 FEET...
AND 4000-4500 FEET ACROSS ERN SANTA CRUZ COUNTY. THERE HAVE BEEN
SEVERAL REPORTS OF SNOW MIXED WITH RAIN ABOVE 3000 FEET VIA SOCIAL
MEDIA. MOUNT LEMMON FIRE DEPARTMENT (ELEV ABOUT 7800 FT) REPORTED A
SNOW ACCUMULATION OF 7.0 INCHES VALID 940 PM MST.
542 DM LOW CENTERED OVER FAR WEST CENTRAL AZ WILL MOVE NEWD INTO
NORTH CENTRAL AZ AROUND DAYBREAK THUR. PRECIP WILL CONTINUE TO MOVE
EWD THE REST OF TONIGHT...AND THE 01/01Z RUC HRRR DEPICTS THE BULK
OF PRECIP TO END FROM TUCSON WWD AROUND 01/08Z OR SO. HAVE NOTED
THAT THE HRRR DEPICTS PRECIP TO END ACROSS ERN SECTIONS SHORTLY
THEREAFTER...OR BY AROUND DAYBREAK THUR.
FOR THE OFFICIAL FORECAST UPDATE...SNOW LEVELS WERE LOWERED TO
REFLECT THE ONGOING CONDITIONS AS NOTED ABOVE. AREAS OF FOG WERE
ADDED FOR THE REST OF TONIGHT AND INTO THUR MORNING FOR ERN PIMA
COUNTY...SANTA CRUZ COUNTY AND THE UPPER SAN PEDRO RIVER VALLEY.
BASED ON RECEIPT OF THE 01/00Z NAM/GFS MOS GUIDANCE...OPTED TO
CHANGE THE FREEZE WATCH FOR THE TUCSON METRO AREA AND ADJOINING
LOCALES WEST-TO-NORTHWEST OF TUCSON TO A HARD FREEZE WARNING LATE
THUR NIGHT/EARLY FRI MORNING.
THE OTHER WINTER STORM WARNINGS...WINTER WEATHER ADVISORIES...AND
FREEZE WATCH CONTINUE UNCHANGED. PRECIP THUR AFTERNOON SHOULD BE
CONFINED TO ERN SECTIONS...AND ANY LINGERING SHOWERS SHOULD BE
MAINLY NEAR THE NEW MEXICO BORDER FRI.
PLEASE REFER TO THE ADDITIONAL SECTIONS FOR FURTHER DETAIL.
&&
.AVIATION...VALID THRU 02/06Z.
WIDESPREAD RAIN AND SNOW WILL OCCUR INTO THURSDAY MORNING...THEN
SCATTERED RAIN/SNOW SHOWERS WILL PREVAIL EAST OF KTUS THURSDAY
AFTERNOON AND THURSDAY EVENING. EXPECT WIDESPREAD MVFR CONDITIONS
INTO THURSDAY MORNING ALONG WITH OCCASIONAL IFR CONDITIONS. CLOUDS
WILL DECREASE WEST OF KTUS THURSDAY AFTERNOON FOLLOWED BY GRADUALLY
IMPROVING SKY CONDITIONS FURTHER EASTWARD TO INCLUDE KTUS THURSDAY
EVENING. SURFACE WIND EAST OF KTUS THE REST OF TONIGHT WILL BE SLY
TO WLY AT 12-20 KTS WITH GUSTS TO 30 KTS. THEREAFTER... SURFACE WIND
WILL BE MAINLY LESS THAN 10 KTS MOST SECTIONS THURSDAY AND THURSDAY
EVENING. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...EXPECT WIDESPREAD RAIN AND SNOW INTO THURSDAY AS A
WINTER STORM SYSTEM MOVES ACROSS THE AREA. A FEW LINGERING SHOWERS
WILL OCCUR EAST OF TUCSON THURSDAY NIGHT INTO FRIDAY. THEREAFTER...
DRY CONDITIONS WILL OCCUR THIS WEEKEND AND INTO NEXT WEEK.
&&
.PREV DISCUSSION...THE NEXT AREA OF CONCERN WILL BE SUB-FREEZING LOW
TEMPS FRIDAY AND SATURDAY MORNINGS...WHEN LOW TEMPS ARE EXPECTED TO
BE IN THE MID 20S TO NEAR 30 FOR MUCH OF THE TUCSON METRO AND INTO
CENTRAL PIMA COUNTY AND SOUTHEAST PINAL COUNTY. AFTER INSPECTION OF
12Z MOS LOW TEMP NUMBERS FOR FRIDAY AND SATURDAY MORNINGS...DECIDED
TO GO WITH A HARD FREEZE WATCH FOR SOUTHEAST PINAL COUNTY...CENTRAL
AND EASTERN PORTIONS OF PIMA COUNTY FRIDAY MORNING...THEN JUST FOR
EASTERN PORTIONS OF PIMA COUNTY AND EASTERN PINAL COUNTY FOR
SATURDAY MORNING SINCE THE LOWS WILL BE SLIGHTLY WARMER SATURDAY
MORNING COMPARED TO FRIDAY...AND AREAL COVERAGE OF TEMPS AT OR BELOW
27 DEGS F WILL BE SMALLER.
AS THE LOW BEGINS TO EJECT TO THE EAST LATE THURSDAY INTO FRIDAY...
LINGERING MOISTURE AND COLD AIR WILL JUSTIFY KEEPING A WINTER
WEATHER ADVISORY FOR THE MOUNTAINS OF GRAHAM AND GREENLEE COUNTIES
AND FOR THE SANTA CATALINA AND RINCON MOUNTAINS OF EASTERN PIMA
COUNTY THROUGH LATE THURSDAY AFTERNOON. THE LOW WILL BE FAR ENOUGH
TO OUR EAST BY LATE FRIDAY/EARLY SATURDAY TO RESULT IN A RETURN TO
DRY CONDITIONS THROUGH THE REMAINDER OF THE FORECAST PERIOD WITH A
WARMING TREND BEGINNING EARLY NEXT WEEK.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 11 AM MST THURSDAY FOR AZZ510-511-514.
WINTER STORM WARNING UNTIL 11 AM MST THURSDAY FOR AZZ506-509
ABOVE 4000 FEET.
WINTER WEATHER ADVISORY UNTIL 11 AM MST THURSDAY FOR AZZ512-513.
WINTER WEATHER ADVISORY FROM 11 AM TO 5 PM MST THURSDAY FOR
AZZ510-511-514.
HARD FREEZE WARNING FROM 3 AM TO 9 AM MST FRIDAY FOR AZZ502-
504>506.
FREEZE WATCH FROM LATE FRIDAY NIGHT THROUGH SATURDAY MORNING
FOR AZZ504-506.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
FRANCIS
PREV DISCUSSION...MOLLERE
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
501 AM EST THU JAN 1 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 429 PM EST WED DEC 31 2014
WV IMAGERY AND RUC ANALYSIS INDICATED NW MID/UPPER LEVEL FLOW FROM
NW CANADA INTO THE GREAT LAKES BETWEEN A TROUGH OVER HUDSON BAY AND
A RIDGE FROM THE ERN PACIFIC INTO BC. A SHORTWAVE TROUGH WAS MOVING
THROUGH UPPER MI WITH ANOTHER WEAKER SHRTWV UPSTREAM OVER MANITOBA.
ANOTHER CLIPPER SHRTWV WAS FARTHER UPSTREAM OVER NW SASK. AT THE
SFC...STRONG WEST WINDS PREVAILED ACROSS THE REGION BETWEEN A 988 MB
LOW NEAR HUDSON BAY AND 1036 MB ARCTIC HIGH PRES INTO THE SRN
PLAINS. THE STRONGEST WINDS THIS MORNING INTO EARLY AFTERNOON ACROSS
LAKE SUPERIOR OCCURRED AS THE STRONGER PRES FALLS SLID THROUGH NRN
ONTARIO. WITH 850 MB TEMPS AROUND -19C AND CONVERGENT WRLY FLOW
DEVELOPING LES HAS INCREASED ACROSS THE KEWEENAW AS WINDS VEERED
FROM SW TO W.
TONIGHT...EXPECT THE STRONGEST LOW LEVEL CONV SUPPORTING LES TO
REMAIN OVER THE KEWEENAW. EVEN WITH A FAVORABLE POSITION OF THE DGZ
IN THE CLOUD LAYER...THE STRONGER WINDS WILL CREATE ENOUGH
COMPACTION/FRACTURING TO LIMIT SLR VALUES CLOSER TO 20/1. SO OVERALL
ACCUMULATIONS TONIGHT IN THE 2 TO 5 INCH RANGE ARE EXPECTED. WINDS
GUSTING INTO THE 30 TO 40 MPH RANGE WILL ALSO CONTINUE TO PRODUCE
CONSIDERABLE BLOWING AND DRIFTING SNOW IN OPEN AREAS WHERE OCNL
WHITEOUT CONDITIONS ARE POSSIBLE. WINDS ARE EXPECTED TO DIMINISH
OVERNIGHT REDUCING THE BLSN HAZARDS.
THU...THE NRN SASK SHRTWV TROUGH WILL BRUSH THE AREA WITH ENOUGH
700-500 MB QVECTOR CONV AND 800-600 MB FGEN TO SUPPORT AN AREA OF
LIGHT SNOW FROM NRN MN INTO NRN WI AND UPPER MI. WITH THE LACK OF
SIGNFICANT MOISTURE INFLOW/AVAILABILITY...SNOW AMOUNTS OF A HALF
INCH OR LESS ARE EXPECTED. HOWEVER...THE DEEPER MOISTURE WITH
INCREASING INVERSION HEIGHTS INTO THE AREA WILL SUPPORT GREATER LES
INTENSITY FOR THE W TO WNW FLOW LES SNOW BELTS. SINCE THE STRONGER
LOW LEVEL CONV IS EXPECTED TO SHIFT SOUTHWARD OVERALL SNOW AMOUNTS
SHOULD REMAIN IN THE 1 TO 3 INCH RANGE.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 501 AM EST THU JAN 1 2015
PERSISTENT RIDGING OVER THE EASTERN PACIFIC/NAMERICA WEST COAST
REGION WILL MAINTAIN A BROAD UPPER TROUGH OVER MUCH OF CANADA AND
THE GREAT LAKES REGION THROUGH THE FIRST WEEK OF JANUARY RESULTING
IN BELOW NORMAL TEMPERATURES AND PERIODS OF LAKE EFFECT SNOW FOR
UPPER MI.
BEGINNING FRIDAY...MODEL CONSENSUS SUGGESTS WINDS WL BACK MORE
WESTERLY AGAIN AS SFC RDG AXIS ADVANCES ACROSS AREA FROM THE NRN
PLAINS. THE GENERALLY WEAK WRLY FLOW ALONG WITH ENHANCED LOW-LVL
CONVERGENCE FROM LAND BREEZES WL HELP FOCUS GENERALLY LIGHT LAKE
EFFECT SNOW ACROSS THE KEWEENAN PENINSULA AND THE FAR ERN SHORELINE
OF THE CWA AS INVERSION BASES CRASH BLO 5KFT WITH DRY AIR NOTED
BENEATH THE INVERSION. SINCE MUCH OF THE DGZ IN STILL WITHIN THE
CLOUD LAYER...LES BANDS COULD YIELD 1-2 INCHES OF FLUFFY
ACCUMULATION DURING THE DAY. WAA CLOUDS AHEAD OF SHORTWAVE MOVING IN
FROM THE NRN PLAINS WILL LIMIT RADIATIONAL COOLING FRIDAY NIGHT BUT
TEMPS SHOULD STILL APPROACH ZERO OR MAYBE EVEN DIP BLO ZERO AT A FEW
OF THE TYPICAL COLDER LOCATIONS OVER THE WESTERN INTERIOR.
THIS WEEKEND...FOCUS IS ON PHASING/INTERACTION OF SPLIT FLOW. TWO
FEATURES WILL COME INTO PLAY...ONE WILL BE THE REMNANTS OF A CLOSED
LOW NOW PRODUCING SNOW OVER THE SW CONUS...AND THE SECOND IS A NRN
BRANCH SHORTWAVE NOW OVER THE ALEUTIAN ISLANDS WHICH IS FCST TO DIVE
SE ACROSS THE NRN ROCKIES FRI NIGHT AND THEN THROUGH THE PLAINS
STATES ON SAT. ASSOCIATED STRONG MID LEVEL WARM AIR ADVECTION AHEAD
OF THIS SHORTWAVE AND ITS ASSOC SFC LOW WILL SPREAD SNOW EAST INTO
MAINLY THE NORTHWEST HALF OF THE CWA ON SAT. WHILE THE MODELS STILL
PEG THE HEAVIEST SNOW TO OCCUR OVER LAKE SUPERIOR...WILL CONTINUE TO
SHOW SOME LIKELY POPS OVER AND AROUND THE KEWEENAW PENINSULA FOR
SATURDAY. AS THIS SNOW IS OCCURRING...THE NORTHERN SHORTWAVE WILL
CONTINUE TO DIVE SOUTHEAST AND BEGIN TO PHASE WITH THE REMNANTS OF
THE SW CONUS UPPER LOW WHICH WILL LEAD TO BOTH FEATURES EJECTING
NORTHEAST THROUGH THE LOWER GREAT LAKES REGION SATURDAY NIGHT INTO
SUNDAY. THE 00Z ECMWF...GFS AND NAM ALL TRENDING DEEPER AND FARTHER
WEST WITH RESULTING SFC LOW WHICH BLEND OF THESE MODELS SHOW A TRACK
THROUGH SRN LWR MI TO NEAR GEORGIAN BAY BY 12Z SUNDAY. THE GEM-NH
MEANWHILE AFTER SHOWING A SIMILAR TRACK TO THE 00Z ECMWF/GFS BLEND
HAS NOW TRENDED FARTHER EAST THROUGH SE LOWER MI INTO ERN ONTARIO.
IF THE LATEST GFS/ECMWF SOLNS HOLD TRUE THIS WOULD MEAN A GREATER
POTENTIAL FOR SYNOPTIC PCPN TO SPREAD INTO UPPER MI...ESPECIALLY THE
EAST HALF...ALONG WITH A GREATER POTENTIAL FOR NORTH FLOW LAKE
ENHANCED SNOW ON THE BACKSIDE OF THE SYSTEM. WILL LIKELY NEED TO
TREND POPS UPWARD ACROSS THE CWA AND ESPECIALLY ALONG LAKE SUPERIOR
ZONES WITH A GREATER POTENTIAL FOR LAKE ENHANCED SNOW SAT NIGHT INTO
SUNDAY. WINDS WILL ALSO RAMP UP WITH TIGHTER GRADIENT ON BACKSIDE OF
SYSTEM WHICH WILL ALSO RESULT IN MORE BLOWING SNOW. WILL HIGHLIGHT
POTENTIAL FOR MODERATE SNOW AND BLOWING SNOW IN HWO...ESPECIALLY
ALONG LAKE SUPERIOR AND THE EAST HALF OF THE CWA FOR SAT NIGHT INTO
SUNDAY EVENING.
LATE SUNDAY NIGHT INTO MONDAY NIGHT...WEAKENING PRES GRADIENT WILL
ALLOW WINDS TO DIMINISH ESPECIALLY OVER THE INTERIOR. WINDS WILL
ALSO BE BACKING MORE WESTERLY ESPECIALLY BY MONDAY IN ADVANCE OF
STRONG SFC HIGH PRES RDG BUILDING IN FROM THE NRN PLAINS...SO EXPECT
LES TO EVENTUALLY BECOME MORE CONFINED TO KEWEENAW AND FAR ERN
SHORELINE AREAS OF THE CWA MONDAY AFTERNOON INTO MON NIGHT. WITH
HEART OF COLDEST AIR (850 MB TEMPS OF -26 TO -28C) COMING ACROSS THE
UPPER LAKES...EXPECT VERY COLD TEMPS SUN NIGHT AND MONDAY. EXPECT
MUCH OF THE INTERIOR CWA TO FALL BLO ZERO AND WOULD NOT BE SURPRISED
TO SEE SOME WESTERN INTERIOR LOCATIONS FALL WELL INTO THE TEENS BLO
ZERO... ESPECIALLY ALONG THE WI BORDER. HIGHS MONDAY WILL REMAIN
VERY COLD WITH READINGS RANGING FROM THE SINGLE DIGITS BLO ZERO
WESTERN INTERIOR TO THE SINGLE DIGITS ABV ZERO EAST AND ALONG THE
GREAT LAKES.
TUESDAY INTO WEDNESDAY...MODELS IN REASONABLY GOOD AGREEMENT SHOWING
ANOTHER CLIPPER SHORTWAVE MOVING ACROSS THE UPPER GREAT LAKES ON
TUESDAY WITH ANOTHER REINFORCING SHOT OF ARCTIC AIR (8H TEMPS FALL
AGAIN TO -28C TO -30C) AS WINDS VEER TO THE NW. THIS WILL BRING LES
FARTHER INLAND AGAIN AFFECTING THE NRN TIER AND ERN HALF COUNTIES
FROM LATE TUE THROUGH WED. LOOK LIKE ONLY THE FAR SOUTH CENTRAL
WOULD ESCAPE THE LES. WITH SUCH A COLD ARCTIC AIRMASS FCST THE DGZ
WILL GET SQUASHED NEAR THE LAKE SFC WHICH WILL LIKELY RESULT IN
SMALLER FLAKE SIZE. THIS WILL LIMIT LES ACCUMULATION BUT AT SAME
TIME WILL BE MORE EFFECTIVE FOR REDUCING VSBY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1209 AM EST THU JAN 1 2015
WINDS HAVE BECOME MORE WESTERLY OVER THE WESTERN U.P. WITH THE
PASSAGE OF A WEAK SHORTWAVE. WESTERLY FLOW HAS RESULTED IN ENHANCED
LES AT KCMX AT TIMES...WITH VSBYS OCCASIONALLY FALLING TO LIFR DUE
TO SNOW AND BLOWING SNOW WHILE CIGS LOWER TO IFR. AS WINDS VEER TO
NW DURING THE LATE MORNING HOURS...EXPECT KCMX CONDITIONS TO IMPROVE
WITH MVFR PREVAILING BY MIDDAY. KIWD TO SEE LES AND BLSN IN NW FLOW
WITH MAINLY MVFR CONDITIONS THERE...WITH BRIEF PERIODS OF IFR DUE TO
HEAVIER LES. KSAW TO SEE MVFR CONDITIONS AS NW DOWNSLOPE THERE NOT
FAVORABLE FOR LOWER CIGS/VSBYS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 412 AM EST THU JAN 1 2015
A LOW OVER S HUDSON BAY WILL SHIFT INTO N QUEBEC FRIDAY MORNING. THE
TROUGH EXTENDING FROM THIS LOW ACROSS LAKE SUPERIOR WILL SLOWLY
WEAKEN. AS A RESULT...EXPECT THE GALES OF 35-40KTS TO SLOWLY
DIMINISH TOO. WHILE HEAVY FREEZING SPRAY HAS DIMINISHED THIS
MORNING...IT WILL PICK UP AGAIN OVER N LAKE SUPERIOR THIS
AFTERNOON-EVENING.
HIGH PRESSURE SINKING ACROSS MINNESOTA THIS EVENING WILL STRETCH
FROM THE GREAT LAKES THROUGH THE OHIO VALLEY ON FRIDAY...AND EXIT TO
SOUTHERN QUEBEC AND THE NEW ENGLAND STATES FRIDAY NIGHT. EXPECT A
LOW ACROSS THE DAKOTAS FRIDAY NIGHT TO CONSOLIDATE WITH AN
ADDITIONAL LOW ACROSS THE MISSISSIPPI VALLEY. THE NEW LOW WILL MOVE
NE AND DEEPEN ACROSS LOWER MICHIGAN AND LAKE HURON SATURDAY
NIGHT...AND EXIT S QUEBEC ON SUNDAY. THIS WILL BRING A TROUGH
SATURDAY NIGHT INTO SUNDAY FOR LAKE SUPERIOR. N-NW GALES OF 35 TO
NEAR 40KTS WILL AGAIN BE POSSIBLE SUNDAY INTO SUNDAY EVENING. BY
MONDAY...A RIDGE WILL SETTLE ACROSS THE N PLAINS AND UPPER
MISSISSIPPI VALLEY. HEAVY FREEZING SPRAY WILL ALSO RETURN AS A COLD
RIDGE WILL SETTLE ACROSS THE N PLAINS AND UPPER MISSISSIPPI VALLEY
MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
MIZ001-003.
LAKE SUPERIOR...
GALE WARNING UNTIL 10 AM EST THIS MORNING FOR LSZ266-267.
GALE WARNING UNTIL 7 AM EST /6 AM CST/ THIS MORNING FOR LSZ162-
241>251-263>265.
HEAVY FREEZING SPRAY WARNING FROM 1 PM THIS AFTERNOON TO 3 AM
EST FRIDAY FOR LSZ263-264.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...VOSS
AVIATION...RJT
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
414 AM EST THU JAN 1 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 429 PM EST WED DEC 31 2014
WV IMAGERY AND RUC ANALYSIS INDICATED NW MID/UPPER LEVEL FLOW FROM
NW CANADA INTO THE GREAT LAKES BETWEEN A TROUGH OVER HUDSON BAY AND
A RIDGE FROM THE ERN PACIFIC INTO BC. A SHORTWAVE TROUGH WAS MOVING
THROUGH UPPER MI WITH ANOTHER WEAKER SHRTWV UPSTREAM OVER MANITOBA.
ANOTHER CLIPPER SHRTWV WAS FARTHER UPSTREAM OVER NW SASK. AT THE
SFC...STRONG WEST WINDS PREVAILED ACROSS THE REGION BETWEEN A 988 MB
LOW NEAR HUDSON BAY AND 1036 MB ARCTIC HIGH PRES INTO THE SRN
PLAINS. THE STRONGEST WINDS THIS MORNING INTO EARLY AFTERNOON ACROSS
LAKE SUPERIOR OCCURRED AS THE STRONGER PRES FALLS SLID THROUGH NRN
ONTARIO. WITH 850 MB TEMPS AROUND -19C AND CONVERGENT WRLY FLOW
DEVELOPING LES HAS INCREASED ACROSS THE KEWEENAW AS WINDS VEERED
FROM SW TO W.
TONIGHT...EXPECT THE STRONGEST LOW LEVEL CONV SUPPORTING LES TO
REMAIN OVER THE KEWEENAW. EVEN WITH A FAVORABLE POSITION OF THE DGZ
IN THE CLOUD LAYER...THE STRONGER WINDS WILL CREATE ENOUGH
COMPACTION/FRACTURING TO LIMIT SLR VALUES CLOSER TO 20/1. SO OVERALL
ACCUMULATIONS TONIGHT IN THE 2 TO 5 INCH RANGE ARE EXPECTED. WINDS
GUSTING INTO THE 30 TO 40 MPH RANGE WILL ALSO CONTINUE TO PRODUCE
CONSIDERABLE BLOWING AND DRIFTING SNOW IN OPEN AREAS WHERE OCNL
WHITEOUT CONDITIONS ARE POSSIBLE. WINDS ARE EXPECTED TO DIMINISH
OVERNIGHT REDUCING THE BLSN HAZARDS.
THU...THE NRN SASK SHRTWV TROUGH WILL BRUSH THE AREA WITH ENOUGH
700-500 MB QVECTOR CONV AND 800-600 MB FGEN TO SUPPORT AN AREA OF
LIGHT SNOW FROM NRN MN INTO NRN WI AND UPPER MI. WITH THE LACK OF
SIGNFICANT MOISTURE INFLOW/AVAILABILITY...SNOW AMOUNTS OF A HALF
INCH OR LESS ARE EXPECTED. HOWEVER...THE DEEPER MOISTURE WITH
INCREASING INVERSION HEIGHTS INTO THE AREA WILL SUPPORT GREATER LES
INTENSITY FOR THE W TO WNW FLOW LES SNOW BELTS. SINCE THE STRONGER
LOW LEVEL CONV IS EXPECTED TO SHIFT SOUTHWARD OVERALL SNOW AMOUNTS
SHOULD REMAIN IN THE 1 TO 3 INCH RANGE.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 316 PM EST WED DEC 31 2014
AN UPPER TROUGH OVER EASTERN CANADA LEAD TO COLD AIR AND LAKE
EFFECT SNOW OVER THE NORTHWEST WIND SNOW BELTS TO START THE PERIOD.
THIS LIGHT TO OCCASIONALLY MODERATE LAKE EFFECT SNOW WILL CONTINUE
IN THOSE NORTHWEST WIND BELTS ON THURSDAY NIGHT...BUT AS THE LOW
LEVEL WINDS BACK LATE THURSDAY NIGHT INTO FRIDAY MORNING...WILL
FOCUS THE POPS/SNOW TO THE WEST-NORTHWEST AREAS ON FRIDAY (AND
WESTERLY AREAS LATE FRIDAY AFTERNOON). WHILE LAKE INDUCED
EQUILIBRIUM LEVELS WILL BE AROUND 8KFT...THERE ARE SOME CONCERNS IN
THE AMOUNT OF MOISTURE AVAILABLE AS SUBSIDENCE AND DRIER AIR ARRIVE
THURSDAY NIGHT FROM A HIGH MOVING SOUTHEAST INTO MINNESOTA.
THUS...WILL STICK WITH A DUSTING TO 3-4IN EVERY 12HRS THROUGH
FRIDAY...WITH THE HIGHEST AMOUNTS OVER THE EAST WITH THE LONGER
FETCH AND SOME INDICATIONS OF A LINGERING TROUGH AIDING
CONVERGENCE TOWARDS WHITEFISH POINT. THE HIGH WILL SHIFT SOUTHEAST
OF THE AREA ON FRIDAY EVENING...BACKING WINDS TO THE SOUTHWEST AND
ONLY LEAVING LAKE EFFECT SNOW OVER THE KEWEENAW FOR FRIDAY NIGHT.
THE FOCUS THEN TURNS TO THE INTERACTION AND PHASING OF THE SPLIT
FLOW FOR THE START OF THE WEEKEND. MODELS SEEM TO COMING INTO
BETTER AGREEMENT ON THE OVERALL IDEA FOR THE WEEKEND...ALTHOUGH
THERE ARE STILL SMALLER DIFFERENCES THAT COULD HAVE AN IMPACT ON
THE AMOUNT OF SNOW SEEN OVER PARTS OF THE U.P. THERE ARE TWO
FEATURES AT PLAY FOR THIS WEEKEND...THE FIRST IS THE REMNANTS OF
THE UPPER LOW PRODUCING SNOW OVER THE SOUTHWEST CONUS TODAY AND THE
SECOND FEATURE IS A SHORTWAVE CURRENTLY OVER THE ALEUTIANS ISLANDS
AND DROPPING SOUTHEAST INTO THE NORTHERN ROCKIES ON FRIDAY NIGHT.
THIS WILL LEAD TO A LOW DEVELOPING IN THE LEE OF THE NORTHERN
ROCKIES AND THEN MOVING EAST INTO THE DAKOTAS AND WESTERN MINNESOTA
BY SATURDAY MORNING. EXPECT SNOW TO SPREAD EAST AHEAD OF THIS LOW
AND INTO THE NORTHWEST HALF OF THE CWA...ASSOCIATED WITH STRONG MID
LEVEL WARM AIR ADVECTION. WHILE THE HEAVIEST SNOW APPEARS TO OCCUR
OVER LAKE SUPERIOR...WILL SHOW SOME LIKELY POPS OVER AND AROUND THE
KEWEENAW PENINSULA FOR SATURDAY. AS THAT IS OCCURRING...THE
NORTHERN SHORTWAVE WILL CONTINUE TO DIVE SOUTHEAST AND PHASE WITH
THE SOUTHERN UPPER LOW AND LEAD TO BOTH EJECTING NORTHEAST THROUGH
THE LOWER GREAT LAKES REGION SATURDAY NIGHT INTO SUNDAY. AS
EXPECTED IN THESE PHASING EVENTS...EACH MODEL RUN GIVES A SLIGHTLY
DIFFERENT IDEA ON THE EVOLUTION OF THE PHASED FEATURES AND IN TURN
THE SURFACE FEATURES. OVERALL...THE GENERAL IDEA IS FOR A
STRENGTHENING LOW TO LIFT NORTHEAST THROUGH SOUTHEAST LOWER
MICHIGAN ON SATURDAY NIGHT AND THEN INTO QUEBEC ON SUNDAY. WITH
THAT TRACK...WOULD EXPECT MUCH OF THE SYNOPTIC
FORCING/PRECIPITATION ASSOCIATED WITH THOSE FEATURES TO MISS THE
U.P....BUT WOULD STILL EXPECT AT LEAST SOME LAKE ENHANCEMENT AS THE
WINDS TURN TO THE NORTHWEST BEHIND THE ELONGATED SURFACE TROUGH
STRETCHING NORTH OVER EASTERN LAKE SUPERIOR LATE SATURDAY NIGHT.
INITIALLY...WOULDN/T EXPECT THE LAKE ENHANCEMENT TO AMOUNT TO TOO
HIGH OF SNOWFALL AMOUNTS ON SATURDAY NIGHT...BUT AS MUCH COLDER AIR
MOVES INTO THE AREA (850MB TEMPS FALLING TO -25C BY 00Z MONDAY) AND
THE DEEPER MOISTURE IS STILL PRESENT FROM THE DEPARTING
SYSTEM...WOULD EXPECT THE LAKE ENHANCEMENT/EFFECT SNOW TO TAKE OFF
ON SUNDAY IN THE NORTHWEST WIND SNOW BELTS. WILL TREND POPS UP TO
DEFINITE VALUES DURING THIS PERIOD AND CONTINUE TO MENTION
MODERATE/HEAVY SNOW WORDING IN THE HWO.
BEHIND THE LOW...EXPECT THE FIRST PART OF THE WORK WEEK TO BE VERY
COLD WITH CONTINUED LAKE EFFECT SNOW. THE CANADIAN UPPER TROUGH
WILL SAG SOUTH INTO THE GREAT LAKES REGION AND KEEP THE COLD AIR IN
PLACE (850MB TEMPS IN THE LOW 20C BELOW ZERO)...WITH ANOTHER
SHORTWAVE MOVING THROUGH ON MONDAY NIGHT POTENTIALLY PULLING 850MB
TEMPERATURES CLOSE TO -30C FOR TUESDAY. THAT WILL LEAD TO VERY COLD
HIGH TEMPERATURES FOR MONDAY/TUESDAY...WITH SOME LOCATIONS OVER THE
INTERIOR WEST EVEN STRUGGLING TO RISE ABOVE 0. IN FACT...LOOKING AT
THE 00Z ECMWF ENSEMBLE MEMBERS AT KSAW AND OTHER SITES IN THE
WESTERN/CENTRAL U.P....THERE MAY END UP BEING A 24-36 HOUR PERIOD OF
SUB ZERO TEMPERATURES LATE SUNDAY NIGHT THROUGH AT LEAST TUESDAY
MORNING. THE COMBINATION OF THE COLD TEMPERATURES AT NIGHT (SINGLE
DIGITS AND TEENS BELOW ZERO) AND WINDS IN THE 5-10MPH RANGE WILL
LEAD TO LOW WIND CHILL VALUES MONDAY/TUESDAY MORNINGS AND
POTENTIALLY EVENING WEDNESDAY MORNING. AS LONG AS THE WIND SPEEDS
STAY UP...WOULD EXPECT THE NEED FOR WIND CHILL ADVISORIES AT A
MINIMUM AND WILL CONTINUE TO ADDRESS IN THE HWO.
AS FOR LAKE EFFECT DURING THE FIRST PART OF NEXT WEEK...EXPECT WINDS
TO BACK TO THE WEST ON MONDAY AND WILL FOCUS THE LAKE EFFECT POPS
IN THOSE AREAS. WITH THE AMOUNT OF COLD AIR IN PLACE...VERY LITTLE
OF THE CLOUD LAYER WILL BE IN THE DGZ AND MOST WILL BE ABOVE
IT...WHICH LEADS TO MORE COLUMN/PLATE SNOWFLAKES AND WOULD EXPECT
ACCUMULATIONS TO BE LIMITED. WINDS WILL SHIFT MORE TO THE NORTHWEST
ON TUESDAY BEHIND THAT NEXT SHORTWAVE AND WILL TREND POPS TO THAT
FAVORED WIND DIRECTION. WITH THE AMOUNT OF COLD AIR...THERE
SHOULDN/T BE MUCH OF AN ISSUE FOR AT LEAST SOME LAKE EFFECT...SO
DID TREND POPS UP TO LIKELY-DEFINITE VALUES EVEN THOUGH AMOUNTS
SHOULD BE LIMITED. AS THE UPPER TROUGH SHIFTS EAST ON WEDNESDAY AND
THROUGH THE END OF THE WORK WEEK...THE UPPER GREAT LAKES REGION
SHOULD SEE A MODERATION IN THEIR TEMPERATURES TOWARDS MORE NORMAL
VALUES TOWARDS THE END OF NEXT WEEK. LOOKING AT THE 00Z ECMWF
ENSEMBLE MEAN FOR DAYS 9-15...IT SHOWS MORE OF A ZONAL FLOW ACROSS
THE CONUS...WHICH WOULD TRANSLATE TO MORE NORMAL OR EVEN SLIGHTLY
ABOVE NORMAL TEMPERATURES HEADING INTO THE MIDDLE OF JANUARY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1209 AM EST THU JAN 1 2015
WINDS HAVE BECOME MORE WESTERLY OVER THE WESTERN U.P. WITH THE
PASSAGE OF A WEAK SHORTWAVE. WESTERLY FLOW HAS RESULTED IN ENHANCED
LES AT KCMX AT TIMES...WITH VSBYS OCCASIONALLY FALLING TO LIFR DUE
TO SNOW AND BLOWING SNOW WHILE CIGS LOWER TO IFR. AS WINDS VEER TO
NW DURING THE LATE MORNING HOURS...EXPECT KCMX CONDITIONS TO IMPROVE
WITH MVFR PREVAILING BY MIDDAY. KIWD TO SEE LES AND BLSN IN NW FLOW
WITH MAINLY MVFR CONDITIONS THERE...WITH BRIEF PERIODS OF IFR DUE TO
HEAVIER LES. KSAW TO SEE MVFR CONDITIONS AS NW DOWNSLOPE THERE NOT
FAVORABLE FOR LOWER CIGS/VSBYS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 412 AM EST THU JAN 1 2015
A LOW OVER S HUDSON BAY WILL SHIFT INTO N QUEBEC FRIDAY MORNING. THE
TROUGH EXTENDING FROM THIS LOW ACROSS LAKE SUPERIOR WILL SLOWLY
WEAKEN. AS A RESULT...EXPECT THE GALES OF 35-40KTS TO SLOWLY
DIMINISH TOO. WHILE HEAVY FREEZING SPRAY HAS DIMINISHED THIS
MORNING...IT WILL PICK UP AGAIN OVER N LAKE SUPERIOR THIS
AFTERNOON-EVENING.
HIGH PRESSURE SINKING ACROSS MINNESOTA THIS EVENING WILL STRETCH
FROM THE GREAT LAKES THROUGH THE OHIO VALLEY ON FRIDAY...AND EXIT TO
SOUTHERN QUEBEC AND THE NEW ENGLAND STATES FRIDAY NIGHT. EXPECT A
LOW ACROSS THE DAKOTAS FRIDAY NIGHT TO CONSOLIDATE WITH AN
ADDITIONAL LOW ACROSS THE MISSISSIPPI VALLEY. THE NEW LOW WILL MOVE
NE AND DEEPEN ACROSS LOWER MICHIGAN AND LAKE HURON SATURDAY
NIGHT...AND EXIT S QUEBEC ON SUNDAY. THIS WILL BRING A TROUGH
SATURDAY NIGHT INTO SUNDAY FOR LAKE SUPERIOR. N-NW GALES OF 35 TO
NEAR 40KTS WILL AGAIN BE POSSIBLE SUNDAY INTO SUNDAY EVENING. BY
MONDAY...A RIDGE WILL SETTLE ACROSS THE N PLAINS AND UPPER
MISSISSIPPI VALLEY. HEAVY FREEZING SPRAY WILL ALSO RETURN AS A COLD
RIDGE WILL SETTLE ACROSS THE N PLAINS AND UPPER MISSISSIPPI VALLEY
MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
MIZ001-003.
LAKE SUPERIOR...
GALE WARNING UNTIL 10 AM EST THIS MORNING FOR LSZ266-267.
GALE WARNING UNTIL 7 AM EST /6 AM CST/ THIS MORNING FOR LSZ162-
241>251-263>265.
HEAVY FREEZING SPRAY WARNING FROM 1 PM THIS AFTERNOON TO 3 AM
EST FRIDAY FOR LSZ263-264.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...RJT
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1210 AM EST THU JAN 1 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 429 PM EST WED DEC 31 2014
WV IMAGERY AND RUC ANALYSIS INDICATED NW MID/UPPER LEVEL FLOW FROM
NW CANADA INTO THE GREAT LAKES BETWEEN A TROUGH OVER HUDSON BAY AND
A RIDGE FROM THE ERN PACIFIC INTO BC. A SHORTWAVE TROUGH WAS MOVING
THROUGH UPPER MI WITH ANOTHER WEAKER SHRTWV UPSTREAM OVER MANITOBA.
ANOTHER CLIPPER SHRTWV WAS FARTHER UPSTREAM OVER NW SASK. AT THE
SFC...STRONG WEST WINDS PREVAILED ACROSS THE REGION BETWEEN A 988 MB
LOW NEAR HUDSON BAY AND 1036 MB ARCTIC HIGH PRES INTO THE SRN
PLAINS. THE STRONGEST WINDS THIS MORNING INTO EARLY AFTERNOON ACROSS
LAKE SUPERIOR OCCURRED AS THE STRONGER PRES FALLS SLID THROUGH NRN
ONTARIO. WITH 850 MB TEMPS AROUND -19C AND CONVERGENT WRLY FLOW
DEVELOPING LES HAS INCREASED ACROSS THE KEWEENAW AS WINDS VEERED
FROM SW TO W.
TONIGHT...EXPECT THE STRONGEST LOW LEVEL CONV SUPPORTING LES TO
REMAIN OVER THE KEWEENAW. EVEN WITH A FAVORABLE POSITION OF THE DGZ
IN THE CLOUD LAYER...THE STRONGER WINDS WILL CREATE ENOUGH
COMPACTION/FRACTURING TO LIMIT SLR VALUES CLOSER TO 20/1. SO OVERALL
ACCUMULATIONS TONIGHT IN THE 2 TO 5 INCH RANGE ARE EXPECTED. WINDS
GUSTING INTO THE 30 TO 40 MPH RANGE WILL ALSO CONTINUE TO PRODUCE
CONSIDERABLE BLOWING AND DRIFTING SNOW IN OPEN AREAS WHERE OCNL
WHITEOUT CONDITIONS ARE POSSIBLE. WINDS ARE EXPECTED TO DIMINISH
OVERNIGHT REDUCING THE BLSN HAZARDS.
THU...THE NRN SASK SHRTWV TROUGH WILL BRUSH THE AREA WITH ENOUGH
700-500 MB QVECTOR CONV AND 800-600 MB FGEN TO SUPPORT AN AREA OF
LIGHT SNOW FROM NRN MN INTO NRN WI AND UPPER MI. WITH THE LACK OF
SIGNFICANT MOISTURE INFLOW/AVAILABILITY...SNOW AMOUNTS OF A HALF
INCH OR LESS ARE EXPECTED. HOWEVER...THE DEEPER MOISTURE WITH
INCREASING INVERSION HEIGHTS INTO THE AREA WILL SUPPORT GREATER LES
INTENSITY FOR THE W TO WNW FLOW LES SNOW BELTS. SINCE THE STRONGER
LOW LEVEL CONV IS EXPECTED TO SHIFT SOUTHWARD OVERALL SNOW AMOUNTS
SHOULD REMAIN IN THE 1 TO 3 INCH RANGE.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 316 PM EST WED DEC 31 2014
AN UPPER TROUGH OVER EASTERN CANADA LEAD TO COLD AIR AND LAKE
EFFECT SNOW OVER THE NORTHWEST WIND SNOW BELTS TO START THE PERIOD.
THIS LIGHT TO OCCASIONALLY MODERATE LAKE EFFECT SNOW WILL CONTINUE
IN THOSE NORTHWEST WIND BELTS ON THURSDAY NIGHT...BUT AS THE LOW
LEVEL WINDS BACK LATE THURSDAY NIGHT INTO FRIDAY MORNING...WILL
FOCUS THE POPS/SNOW TO THE WEST-NORTHWEST AREAS ON FRIDAY (AND
WESTERLY AREAS LATE FRIDAY AFTERNOON). WHILE LAKE INDUCED
EQUILIBRIUM LEVELS WILL BE AROUND 8KFT...THERE ARE SOME CONCERNS IN
THE AMOUNT OF MOISTURE AVAILABLE AS SUBSIDENCE AND DRIER AIR ARRIVE
THURSDAY NIGHT FROM A HIGH MOVING SOUTHEAST INTO MINNESOTA.
THUS...WILL STICK WITH A DUSTING TO 3-4IN EVERY 12HRS THROUGH
FRIDAY...WITH THE HIGHEST AMOUNTS OVER THE EAST WITH THE LONGER
FETCH AND SOME INDICATIONS OF A LINGERING TROUGH AIDING
CONVERGENCE TOWARDS WHITEFISH POINT. THE HIGH WILL SHIFT SOUTHEAST
OF THE AREA ON FRIDAY EVENING...BACKING WINDS TO THE SOUTHWEST AND
ONLY LEAVING LAKE EFFECT SNOW OVER THE KEWEENAW FOR FRIDAY NIGHT.
THE FOCUS THEN TURNS TO THE INTERACTION AND PHASING OF THE SPLIT
FLOW FOR THE START OF THE WEEKEND. MODELS SEEM TO COMING INTO
BETTER AGREEMENT ON THE OVERALL IDEA FOR THE WEEKEND...ALTHOUGH
THERE ARE STILL SMALLER DIFFERENCES THAT COULD HAVE AN IMPACT ON
THE AMOUNT OF SNOW SEEN OVER PARTS OF THE U.P. THERE ARE TWO
FEATURES AT PLAY FOR THIS WEEKEND...THE FIRST IS THE REMNANTS OF
THE UPPER LOW PRODUCING SNOW OVER THE SOUTHWEST CONUS TODAY AND THE
SECOND FEATURE IS A SHORTWAVE CURRENTLY OVER THE ALEUTIANS ISLANDS
AND DROPPING SOUTHEAST INTO THE NORTHERN ROCKIES ON FRIDAY NIGHT.
THIS WILL LEAD TO A LOW DEVELOPING IN THE LEE OF THE NORTHERN
ROCKIES AND THEN MOVING EAST INTO THE DAKOTAS AND WESTERN MINNESOTA
BY SATURDAY MORNING. EXPECT SNOW TO SPREAD EAST AHEAD OF THIS LOW
AND INTO THE NORTHWEST HALF OF THE CWA...ASSOCIATED WITH STRONG MID
LEVEL WARM AIR ADVECTION. WHILE THE HEAVIEST SNOW APPEARS TO OCCUR
OVER LAKE SUPERIOR...WILL SHOW SOME LIKELY POPS OVER AND AROUND THE
KEWEENAW PENINSULA FOR SATURDAY. AS THAT IS OCCURRING...THE
NORTHERN SHORTWAVE WILL CONTINUE TO DIVE SOUTHEAST AND PHASE WITH
THE SOUTHERN UPPER LOW AND LEAD TO BOTH EJECTING NORTHEAST THROUGH
THE LOWER GREAT LAKES REGION SATURDAY NIGHT INTO SUNDAY. AS
EXPECTED IN THESE PHASING EVENTS...EACH MODEL RUN GIVES A SLIGHTLY
DIFFERENT IDEA ON THE EVOLUTION OF THE PHASED FEATURES AND IN TURN
THE SURFACE FEATURES. OVERALL...THE GENERAL IDEA IS FOR A
STRENGTHENING LOW TO LIFT NORTHEAST THROUGH SOUTHEAST LOWER
MICHIGAN ON SATURDAY NIGHT AND THEN INTO QUEBEC ON SUNDAY. WITH
THAT TRACK...WOULD EXPECT MUCH OF THE SYNOPTIC
FORCING/PRECIPITATION ASSOCIATED WITH THOSE FEATURES TO MISS THE
U.P....BUT WOULD STILL EXPECT AT LEAST SOME LAKE ENHANCEMENT AS THE
WINDS TURN TO THE NORTHWEST BEHIND THE ELONGATED SURFACE TROUGH
STRETCHING NORTH OVER EASTERN LAKE SUPERIOR LATE SATURDAY NIGHT.
INITIALLY...WOULDN/T EXPECT THE LAKE ENHANCEMENT TO AMOUNT TO TOO
HIGH OF SNOWFALL AMOUNTS ON SATURDAY NIGHT...BUT AS MUCH COLDER AIR
MOVES INTO THE AREA (850MB TEMPS FALLING TO -25C BY 00Z MONDAY) AND
THE DEEPER MOISTURE IS STILL PRESENT FROM THE DEPARTING
SYSTEM...WOULD EXPECT THE LAKE ENHANCEMENT/EFFECT SNOW TO TAKE OFF
ON SUNDAY IN THE NORTHWEST WIND SNOW BELTS. WILL TREND POPS UP TO
DEFINITE VALUES DURING THIS PERIOD AND CONTINUE TO MENTION
MODERATE/HEAVY SNOW WORDING IN THE HWO.
BEHIND THE LOW...EXPECT THE FIRST PART OF THE WORK WEEK TO BE VERY
COLD WITH CONTINUED LAKE EFFECT SNOW. THE CANADIAN UPPER TROUGH
WILL SAG SOUTH INTO THE GREAT LAKES REGION AND KEEP THE COLD AIR IN
PLACE (850MB TEMPS IN THE LOW 20C BELOW ZERO)...WITH ANOTHER
SHORTWAVE MOVING THROUGH ON MONDAY NIGHT POTENTIALLY PULLING 850MB
TEMPERATURES CLOSE TO -30C FOR TUESDAY. THAT WILL LEAD TO VERY COLD
HIGH TEMPERATURES FOR MONDAY/TUESDAY...WITH SOME LOCATIONS OVER THE
INTERIOR WEST EVEN STRUGGLING TO RISE ABOVE 0. IN FACT...LOOKING AT
THE 00Z ECMWF ENSEMBLE MEMBERS AT KSAW AND OTHER SITES IN THE
WESTERN/CENTRAL U.P....THERE MAY END UP BEING A 24-36 HOUR PERIOD OF
SUB ZERO TEMPERATURES LATE SUNDAY NIGHT THROUGH AT LEAST TUESDAY
MORNING. THE COMBINATION OF THE COLD TEMPERATURES AT NIGHT (SINGLE
DIGITS AND TEENS BELOW ZERO) AND WINDS IN THE 5-10MPH RANGE WILL
LEAD TO LOW WIND CHILL VALUES MONDAY/TUESDAY MORNINGS AND
POTENTIALLY EVENING WEDNESDAY MORNING. AS LONG AS THE WIND SPEEDS
STAY UP...WOULD EXPECT THE NEED FOR WIND CHILL ADVISORIES AT A
MINIMUM AND WILL CONTINUE TO ADDRESS IN THE HWO.
AS FOR LAKE EFFECT DURING THE FIRST PART OF NEXT WEEK...EXPECT WINDS
TO BACK TO THE WEST ON MONDAY AND WILL FOCUS THE LAKE EFFECT POPS
IN THOSE AREAS. WITH THE AMOUNT OF COLD AIR IN PLACE...VERY LITTLE
OF THE CLOUD LAYER WILL BE IN THE DGZ AND MOST WILL BE ABOVE
IT...WHICH LEADS TO MORE COLUMN/PLATE SNOWFLAKES AND WOULD EXPECT
ACCUMULATIONS TO BE LIMITED. WINDS WILL SHIFT MORE TO THE NORTHWEST
ON TUESDAY BEHIND THAT NEXT SHORTWAVE AND WILL TREND POPS TO THAT
FAVORED WIND DIRECTION. WITH THE AMOUNT OF COLD AIR...THERE
SHOULDN/T BE MUCH OF AN ISSUE FOR AT LEAST SOME LAKE EFFECT...SO
DID TREND POPS UP TO LIKELY-DEFINITE VALUES EVEN THOUGH AMOUNTS
SHOULD BE LIMITED. AS THE UPPER TROUGH SHIFTS EAST ON WEDNESDAY AND
THROUGH THE END OF THE WORK WEEK...THE UPPER GREAT LAKES REGION
SHOULD SEE A MODERATION IN THEIR TEMPERATURES TOWARDS MORE NORMAL
VALUES TOWARDS THE END OF NEXT WEEK. LOOKING AT THE 00Z ECMWF
ENSEMBLE MEAN FOR DAYS 9-15...IT SHOWS MORE OF A ZONAL FLOW ACROSS
THE CONUS...WHICH WOULD TRANSLATE TO MORE NORMAL OR EVEN SLIGHTLY
ABOVE NORMAL TEMPERATURES HEADING INTO THE MIDDLE OF JANUARY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1209 AM EST THU JAN 1 2015
WINDS HAVE BECOME MORE WESTERLY OVER THE WESTERN U.P. WITH THE
PASSAGE OF A WEAK SHORTWAVE. WESTERLY FLOW HAS RESULTED IN ENHANCED
LES AT KCMX AT TIMES...WITH VSBYS OCCASIONALLY FALLING TO LIFR DUE
TO SNOW AND BLOWING SNOW WHILE CIGS LOWER TO IFR. AS WINDS VEER TO
NW DURING THE LATE MORNING HOURS...EXPECT KCMX CONDITIONS TO IMPROVE
WITH MVFR PREVAILING BY MIDDAY. KIWD TO SEE LES AND BLSN IN NW FLOW
WITH MAINLY MVFR CONDITIONS THERE...WITH BRIEF PERIODS OF IFR DUE TO
HEAVIER LES. KSAW TO SEE MVFR CONDITIONS AS NW DOWNSLOPE THERE NOT
FAVORABLE FOR LOWER CIGS/VSBYS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 429 PM EST WED DEC 31 2014
LAKE SUPERIOR WILL BE STUCK BETWEEN VERY STRONG HIGH PRESSURE ACROSS
THE S PLAINS AND A DEEP HUDSON BAY LOW TODAY. GALES OF 35-45KTS WILL
CONTINUE BEFORE SLOWLY DIMINISHING TO 35KTS LATE TONIGHT INTO
THURSDAY MORNING OUT OF THE W-NW. GIVEN PLENTY OF COLD AIR...AND
STRONG WINDS...HEAVY FREEZING SPRAY WILL ALSO BE A CONCERN INTO
THURSDAY.
LOOK FOR THE TROUGH OVER LAKE SUPERIOR TO DEEPEN TONIGHT THROUGH
THURSDAY. THE HUDSON BAY LOW WILL SHIFT AND WEAKEN ACROSS N QUEBEC
THURSDAY NIGHT...ALLOWING THE TROUGH ACROSS LAKE SUPERIOR TO WEAKEN
AS WELL. HIGH PRESSURE SINKING ACROSS MANITOBA AND MINNESOTA
THURSDAY NIGHT WILL BUILD RIDGE ACROSS LAKE SUPERIOR ON FRIDAY AS IT
PROGRESSES ACROSS THE REMAINDER OF THE GREAT LAKES. A WEAK TROUGH
WILL LIKELY LINGER ACROSS MAINLY E LAKE SUPERIOR DURING THIS TIME.
EXPECT A LOW NEAR MONTANA ON FRIDAY TO TRACK ACROSS THE N AND
CENTRAL PLAINS SATURDAY MORNING...AND THE MID MISSISSIPPI VALLEY
SATURDAY AFTERNOON...BEFORE DEEPENING NORTHEASTWARD ACROSS THE LOWER
GREAT LAKES AND QUEBEC LATE SATURDAY NIGHT INTO SUNDAY. THIS WILL
BRING A TROUGH THROUGH THE AREA SATURDAY NIGHT INTO SUNDAY...ALONG
WITH THE POTENTIAL FOR N-NW GALES. HEAVY FREEZING SPRAY WILL
ALSO MAKE A RETURN ACROSS MUCH OF LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
MIZ001-003.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 4 AM EST /3 AM CST/ EARLY
THIS MORNING FOR LSZ162-240>245-248>251-263>267.
GALE WARNING UNTIL 10 AM EST THIS MORNING FOR LSZ266-267.
GALE WARNING UNTIL 7 AM EST /6 AM CST/ THIS MORNING FOR LSZ162-
241>251-263>265.
HEAVY FREEZING SPRAY WARNING UNTIL 1 AM EST EARLY THIS MORNING
FOR LSZ246-247.
LAKE MICHIGAN...
HEAVY FREEZING SPRAY WARNING UNTIL 1 AM EST EARLY THIS MORNING
FOR LMZ221-248-250.
GALE WARNING UNTIL 1 AM EST EARLY THIS MORNING FOR LMZ221-250.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...RJT
MARINE...JLB
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1259 AM EST THU JAN 1 2015
.SYNOPSIS...
A COLD FRONT WILL BRING THE POTENTIAL FOR LAKE SNOWS NORTH OF THE
NEW YORK THRUWAY THURSDAY NIGHT AND FRIDAY. ON SATURDAY AFTERNOON, A
STORM SYSTEM WILL MOVE IN FROM THE OHIO VALLEY, BRINGING A MIX OF
RAIN AND SNOW SATURDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
920 PM UPDATE...
THE LAKE EFFECT SNOW BAND OVER THE NORTH COUNTRY IS PROGGED TO
SKIRT NORTHERN ONEIDA COUNTY BETWEEN 7Z AND 10Z, BRINGING LIGHT
SNOW ACCUMULATION.
LATEST HRRR OUTPUT SUGGESTS A FEW FLURRIES OR LIGHT SNOW SHOWERS
MAY SNEAK INTO NORTHWESTERN STEUBEN COUNTY OVERNIGHT, DUE TO A
FLUCTUATING ERIE BAND. ADDED A SLIGHT CHC POP.
INTERIOR VALLEY TEMPERATURES ARE ALREADY NEAR PROJECTED OVERNIGHT
MINS, SO HAVE ADJUSTED MINS DOWNWARD.
1255 PM UPDATE...
LAKE SNOWS HV EXITED NRN ONEIDA CNTY THUS HV CANCELLED THE WARNING.
EXPECT LK EFFECT SNOW TO RMN WELL TO THE NORTH ON 240-250 FLOW THRU
THE OVRNGT WITH A SLIGHT WOBBLE TO THE SOUTH POSSIBLE TWD 09Z WITH
PERHAPS A FEW LGT SNOW SHOWERS AND/OR FLURRIES SNEAKING INTO EXTREME
NRN ONEIDA THRU DAYBREAK. VRY MINIMAL ACCUMS ARE EXPECTED WITH THIS
WOBBLE.
EXPECTING THAT LK ERIE BAND WL STAY A TAD TOO FAR WEST TO AFFECT
FINGER LAKES THIS EVNG INTO THE OVRNGT. NOTHING MORE THAN CLD CVR
EXPECTED ON 240 DEGREE FLOW. EXPECT MINS TO DROP INTO THE LWR TEENS
BY MRNG WITH SINGLE DIGITS POSSIBLE IN NOTORIOUSLY COLDER VALLEYS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY/...
245 PM UPDATE...
LAKE EFFECT SNOW WL RMN NORTH OF CWA FOR MOST OF TOMORROW. THERE IS
SOME INDICATION THAT SNOW BAND WL MAKE A RUN TWD THE SOUTH ARND 18Z
BUT QUICKLY RETREAT BACK TO THE NORTH AS WINDS BACK TWD THE SOUTH
AHD OF APPCHG CDFNT. HV MAINLY CONFINED 20-30 POPS FOR LOCATIONS
NORTH OF THE NY THRUWAY DRG THE AFTN HRS. AS WINDS GO SRLY TEMPS WL
WARM INTO THE 20S BY AFTN, WRMR THAN TDA THO STILL BLO NRML VALUES.
CDFNT WL SLIP SOUTH THRU SRN CANADA LATE THUR NGT WITH LK SNOWS
DVLPNG AHD OF AND ALONG THIS BNDRY. MODELS SEEM TO BE IN PRETTY GOOD
AGREEMENT WITH FROPA WITH ONLY SVR HRS DIFFERENCE ON TIMING. THUS
EXPECT LK EFFECT SNOW SHOWERS TO COMMENCE LATE EVNG AND TWD MIDNIGHT
WITH LKLY BAND OF SNOW SHOWERS DROPPING INTO NRN ONEIDA AFTER 08Z.
WL ALLOW LATER SHIFTS TO GET A BETTER HANDLE ON ANY POTENTIAL
HEADLINES FOR LK EFFECT EVENT TOMORROW NIGHT/FRI MRNG. GFS AND NAM
DIFFER ON HOW LONG FLOW WL BE ALIGNED FOR FAVORABLE LK SNOWS ON
FRIDAY. NAM PUSHES FRONT THRU QUICKLY AND ALLOWS DRIER AIR TO
DISRUPT SNOWS DRG THE AFTN WHILE GFS KEEP INVERSION UP ARND 800MB
DRG THE AFTN HRS WITH FAIRLY STEADY STATE 280 DEGREE FLOW. FEEL IT
PRUDENT TO HOLD OFF ON ANY HEADLINES AT THIS TIME DUE TO VARYING
DEGREES OF UNCERTAINTY.
SFC HIPRES WL BEGIN BUILDING IN LATE FRI NGT THO SOME REMNANT SNOWS
MAY STILL EXIST NORTH OF THE THRUWAY THRU 06Z SAT. QUIET WX EXPECTED
UNTIL SYSTEM MVS IN FM THE SOUTH AFT 18Z SATURDAY. COLD AIR DAMMING
PROGGED ACRS ERN ZONES THRU END OF SHORT TERM PD THUS PCPN WL MV IN
AS ALL SNOW THRU 00Z SUN.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
MAIN FOCUS CONTINUES TO BE EARLY IN THE PERIOD WITH MED RANGE
MODELS IN PRETTY GOOD SYNOPTIC AGREEMENT THAT A PHASING SOUTHERN
STREAM/NORTHERN STREAM TROF WILL EJECT A SFC LOW THROUGH THE GREAT
LAKES REGION AND EASTERN ONTARIO/QUEBEC ON SATURDAY NIGHT AND
SUNDAY. THIS IS, OF COURSE, A TRACK THAT SIGNALS A SNOW-TO-MIX-TO-RAIN
EVENT FOR CNY/NEPA...FOLLOWED BY A DRY SLOT AND SHOWERY
PRECIPITATION ON THE BACK SIDE SUN-MON. GIVEN THE MODEL AGREEMENT
AND TRENDS...THIS IS A FAIRLY HIGH CONFIDENCE EVENT SO WILL
CONTINUE WITH CAT POP ALREADY OFFERED BY PREVIOUS FCST.
BEYOND MONDAY...A BROAD UPPER LEVEL TROF RESIDENT ACROSS THE
NORTHEAST AND GTLKS WILL MAINTAIN A COLD AND UNSTABLE WEST-NW FLOW
WITH TRANSIENT UPPER LEVEL WAVES GENERATING PERIODS OF LAKE SNOW
RESPONSES TO THE EAST OF ERIE AND ONTARIO. HAVE PRETTY MUCH
CONSTANT CHANCES FOR SNOW SHOWERS OR FLURRIES GOING THROUGH WEDNESDAY.
WITH THE EXCEPTION OF AN ABNORMALLY MILD SUNDAY...TEMPERATURES
WILL BE AT OR BELOW NORMAL DURING THIS TIME.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
06Z UPDATE...
VFR STILL EXPECTED FOR THE NEXT 24 HOURS...EXCEPT LAKE EFFECT
-SHSN DROPPING INTO KRME AND THEN KSYR 03Z-06Z FRIDAY WITH
ASSOCIATED MVFR TO IFR VIS. UNTIL THEN...SCT-BKN CLOUDS AROUND
4-5 KFT FOR THE NY TERMINALS COURTESY OF LAKE ERIE MOISTURE
CARRYING ACROSS...AND ONLY PATCHY HIGH CIRRUS FOR KAVP 15-25 KFT
AGL. WINDS GENERALLY SW TO WSW 10-15 KTS WITH GUSTS DURING THE
DAYTIME HOURS IN LOWER 20S KT RANGE. KSYR-KRME WINDS SLIGHTLY
VEERING MORE WESTERLY TOWARDS END OF TAF PERIOD.
OUTLOOK...
FRI...LAKE EFFECT SNOW BAND IN VICINITY OF KRME-KSYR WITH
ASSOCIATED IFR VIS AT TIMES. LOCALIZED BRIEF MVFR-IFR SNOW SHOWERS
POSSIBLE KITH-KBGM.
SAT/SAT NGT...BECOMING IFR WITH SNOW DEVELOPING...CHANGING TO
WINTRY MIX AND OCNL RAIN/FRZG RAIN OVERNIGHT.
SUN...VFR. SCT RAIN SHOWERS.
MON...MVFR. SCT SNOW SHOWERS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJP/PVF
NEAR TERM...DJP/PVF
SHORT TERM...PVF
LONG TERM...JAB
AVIATION...MDP
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
900 AM MST THU JAN 1 2015
...FREEZING TEMPERATURES LIKELY AT MANY LOWER DESERT LOCATIONS AGAIN
TONIGHT...
.SYNOPSIS...
THE STRONG AND VERY COLD STORM SYSTEM THAT BROUGHT RAIN AND LOW
ELEVATION SNOWFALL TO THE DESERT SOUTHWEST WILL SLOWLY MOVE OFF TO
THE EAST TODAY. IN ITS WAKE...WELL BELOW NORMAL TEMPERATURES WILL
PERSIST ACROSS THE REGION THROUGH SUNDAY. HIGH PRESSURE BUILDING IN
FROM THE WEST WILL BRING A GRADUAL WARMING TREND FRIDAY THROUGH THE
MIDDLE PART OF NEXT WEEK.
&&
.DISCUSSION...
AFTER A RATHER INTERESTING NEW YEAR/S EVE...WHICH SAW NUMEROUS
REPORTS OF SNOW FLURRIES ACROSS THE GREATER PHX AREA JUST BEFORE
MIDNIGHT...THIS MORNING HAS STARTED OUT ON THE COLD SIDE...WITH MOST
OUTLYING LOWER DESERT LOCATIONS REPORTING LOWS AT/BELOW FREEZING.
CURRENTLY...OUTSIDE OF SOME MID-LEVEL CLOUDINESS ACROSS
SOUTH-CENTRAL ARIZONA...MOST AREAS ARE SEEING THE RETURN OF SUNNY TO
PARTLY SUNNY SKIES. TODAY STILL APPEARS IT WILL BE A RATHER COLD
ONE...WITH 850MB TEMPS REMAINING IN THE -2 TO -4C
RANGE...SUPPORTING HIGH TEMPS ONLY IN THE MID-40 TO LOWER-50
RANGE...IN SPITE OF THE EXPECTED SUNSHINE. AS FAR AS THE VERY SHORT
TERM IS CONCERNED...OTHER THAN SOME MINOR ADJUSTMENTS TO REDUCE POPS
AND TO THE TEMP AND DEWPOINT GRIDS...CURRENT GRIDS AND ZONE
FORECASTS STILL LOOK GOOD...AND NO FURTHER UPDATES ARE PLANNED.
&&
.PREVIOUS DISCUSSION...
WELL-DEFINED VORT MAX CONTINUES TO SLIDE EASTWARD ACROSS NORTHERN AZ
EARLY THIS MORNING. ELONGATED BAND OF COOLER CLOUDS ASSOCIATED WITH
STRONG JET AND VORTICITY-FORCED ASCENT HAS PUSHED STEADILY EASTWARD
INTO NORTHERN AND EASTERN AZ. LAST GASP OF PRECIPITATION ACROSS THE
PHOENIX AREA WAS IN THE FORM OF LIGHT SNOW ACROSS MANY SPOTS JUST
BEFORE MIDNIGHT. EVEN IN THE LOWEST ELEVATIONS OF THE VALLEY...A MIX
OF RAIN AND SNOW WAS OBSERVED.
FOR THIS MORNING...GLOBAL AND HI-RES GUIDANCE INCLUDING THE HRRR ARE
IN GOOD AGREEMENT THAT LIGHT SNOW WILL CONTINUE TO TAPER OFF ACROSS
SOUTHERN GILA COUNTY WITH LITTLE ADDITIONAL ACCUMULATION. END TIME
OF THE WINTER STORM WARNING FOR THE HIGHER ELEVATIONS OF SOUTHERN
GILA COUNTY HAS BEEN TRIMMED TO 6 AM. WITH A SUBSIDENT FLOW
EXPECTED...POPS WERE ALSO LOWERED ACROSS THESE AREAS AND IN THE
LOWER DESERTS THROUGH THIS AFTERNOON. NEVERTHELESS...SCATTERED
CLOUDS WILL WRAP AROUND THE DEPARTING LOW PRESSURE SYSTEM PRODUCING
PARTLY CLOUDY SKIES AND ISOLATED SNOW FLURRIES.
AFTER A VERY COLD MORNING...TEMPERATURES WILL AGAIN STRUGGLE TO
REACH THE 50 DEGREE MARK...MARKING THE COLDEST MAX TEMPERATURES
SINCE THE FREEZING EVENT IN JANUARY 2013. THE COLD AFTERNOON WILL
SET THE STAGE FOR ANOTHER COLD NIGHT. MOSTLY CLEAR SKIES AND LIGHT
WINDS IN THE WAKE OF THE DEPARTING LOW PRESSURE SYSTEM WILL PROMOTE
RADIATIONAL COOLING AND A FREEZE WARNING REMAINS IN EFFECT FOR MUCH
OF THE LOWER DESERTS INCLUDING THE PHOENIX AREA. LATEST STATISTICAL
GUIDANCE HAS TRENDED SOMEWHAT COLDER AND IMPERIAL COUNTY WAS ALSO
ADDED TO THE WARNING.
OPERATIONAL MODELS REMAIN IN EXCELLENT AGREEMENT THROUGH THE
EXTENDED...INDICATING THAT PACIFIC HIGH PRESSURE WILL BUILD ACROSS
THE REGION. THIS WILL RESULT IN DRY CONDITIONS ALONG WITH INCREASING
THICKNESSES AND A GRADUAL WARMING TREND THROUGH THE MIDDLE OF NEXT
WEEK. HOWEVER...TEMPERATURES WILL REMAIN BELOW NORMAL THROUGH MONDAY
WITH COLD MORNINGS. A FREEZE WARNING MAY ULTIMATELY BE NEEDED FOR
PORTIONS OF THE AREA AGAIN SATURDAY MORNING.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA AND KSDL...
MOIST BOUNDARY LAYER CONDITIONS REMAIN ACROSS THE AREA WITH PATCHES
OF LOW VFR STRATOCU PERSISTING ACROSS SOUTH-CENTRAL ARIZONA. THE
STRATOCU DECK AT 4-5K FEET WILL AFFECT THE PHOENIX TERMINALS FOR A
GOOD PORTION OF THIS MORNING AND POSSIBLY INTO THE AFTERNOON. CIGS
FOR THIS AFTERNOON AND EVENING WILL RISE TO AROUND 6K FEET AND
SHOULD BE MORE SCATTERED. LIGHT WINDS WILL DOMINATE THROUGH THE
PERIOD AND GENERALLY FOLLOW TYPICAL DIURNAL WIND PATTERNS.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
CLEAR TO MOSTLY CLEAR SKIES AND LIGHT WINDS WILL LAST THROUGH AT
LEAST FRIDAY MORNING. NO AVIATION IMPACTS EXPECTED.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SATURDAY THROUGH WEDNESDAY...
A REBOUND IN TEMPERATURES WILL HAPPEN THIS WEEKEND INTO NEXT WITH
HIGHS REACHING NORMALS BY NEXT MONDAY AND WARMING EVEN FURTHER BY
NEXT WEDNESDAY. MINIMUM RELATIVE HUMIDITIES OF 15 TO 30 PERCENT ON
SATURDAY WILL GRADUALLY LOWER THROUGH THE PERIOD WITH VALUES IN THE
TEENS TO LOWER 20S FOR NEXT TUESDAY AND WEDNESDAY. WINDS WILL REMAIN
LIGHT THROUGH THE PERIOD UNDER STRONG HIGH PRESSURE.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...FREEZE WARNING UNTIL 9 AM MST THIS MORNING AZZ020>022-026>028.
FREEZE WARNING FROM 11 PM THIS EVENING TO 9 AM MST FRIDAY
AZZ020>023-026>028.
WINTER STORM WARNING UNTIL 6 AM MST EARLY THIS MORNING ABOVE
3500 FEET FOR AZZ024.
CA...FREEZE WARNING UNTIL 8 AM PST THIS MORNING CAZ033.
FREEZE WARNING FROM 10 PM THIS EVENING TO 8 AM PST FRIDAY
CAZ033.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...PERCHA/HIRSCH
AVIATION....KUHLMAN
FIRE WEATHER...KUHLMAN
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
512 AM MST THU JAN 1 2015
...FREEZING TEMPERATURES LIKELY AT MANY LOWER DESERT LOCATIONS THIS
MORNING AND AGAIN TONIGHT...
.SYNOPSIS...
THE STRONG AND VERY COLD STORM SYSTEM THAT BROUGHT RAIN AND LOW
ELEVATION SNOWFALL TO THE DESERT SOUTHWEST WILL SLOWLY MOVE OFF TO
THE EAST TODAY. IN ITS WAKE...WELL BELOW NORMAL TEMPERATURES WILL
PERSIST ACROSS THE REGION THROUGH SUNDAY. HIGH PRESSURE BUILDING IN
FROM THE WEST WILL BRING A GRADUAL WARMING TREND FRIDAY THROUGH THE
MIDDLE PART OF NEXT WEEK.
&&
.DISCUSSION...
WELL-DEFINED VORT MAX CONTINUES TO SLIDE EASTWARD ACROSS NORTHERN AZ
EARLY THIS MORNING. ELONGATED BAND OF COOLER CLOUDS ASSOCIATED WITH
STRONG JET AND VORTICITY-FORCED ASCENT HAS PUSHED STEADILY EASTWARD
INTO NORTHERN AND EASTERN AZ. LAST GASP OF PRECIPITATION ACROSS THE
PHOENIX AREA WAS IN THE FORM OF LIGHT SNOW ACROSS MANY SPOTS JUST
BEFORE MIDNIGHT. EVEN IN THE LOWEST ELEVATIONS OF THE VALLEY...A MIX
OF RAIN AND SNOW WAS OBSERVED.
FOR THIS MORNING...GLOBAL AND HI-RES GUIDANCE INCLUDING THE HRRR ARE
IN GOOD AGREEMENT THAT LIGHT SNOW WILL CONTINUE TO TAPER OFF ACROSS
SOUTHERN GILA COUNTY WITH LITTLE ADDITIONAL ACCUMULATION. END TIME
OF THE WINTER STORM WARNING FOR THE HIGHER ELEVATIONS OF SOUTHERN
GILA COUNTY HAS BEEN TRIMMED TO 6 AM. WITH A SUBSIDENT FLOW
EXPECTED...POPS WERE ALSO LOWERED ACROSS THESE AREAS AND IN THE
LOWER DESERTS THROUGH THIS AFTERNOON. NEVERTHELESS...SCATTERED
CLOUDS WILL WRAP AROUND THE DEPARTING LOW PRESSURE SYSTEM PRODUCING
PARTLY CLOUDY SKIES AND ISOLATED SNOW FLURRIES.
AFTER A VERY COLD MORNING...TEMPERATURES WILL AGAIN STRUGGLE TO
REACH THE 50 DEGREE MARK...MARKING THE COLDEST MAX TEMPERATURES
SINCE THE FREEZING EVENT IN JANUARY 2013. THE COLD AFTERNOON WILL
SET THE STAGE FOR ANOTHER COLD NIGHT. MOSTLY CLEAR SKIES AND LIGHT
WINDS IN THE WAKE OF THE DEPARTING LOW PRESSURE SYSTEM WILL PROMOTE
RADIATIONAL COOLING AND A FREEZE WARNING REMAINS IN EFFECT FOR MUCH
OF THE LOWER DESERTS INCLUDING THE PHOENIX AREA. LATEST STATISTICAL
GUIDANCE HAS TRENDED SOMEWHAT COLDER AND IMPERIAL COUNTY WAS ALSO
ADDED TO THE WARNING.
OPERATIONAL MODELS REMAIN IN EXCELLENT AGREEMENT THROUGH THE
EXTENDED...INDICATING THAT PACIFIC HIGH PRESSURE WILL BUILD ACROSS
THE REGION. THIS WILL RESULT IN DRY CONDITIONS ALONG WITH INCREASING
THICKNESSES AND A GRADUAL WARMING TREND THROUGH THE MIDDLE OF NEXT
WEEK. HOWEVER...TEMPERATURES WILL REMAIN BELOW NORMAL THROUGH MONDAY
WITH COLD MORNINGS. A FREEZE WARNING MAY ULTIMATELY BE NEEDED FOR
PORTIONS OF THE AREA AGAIN SATURDAY MORNING.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA AND KSDL...
MOIST BOUNDARY LAYER CONDITIONS REMAIN ACROSS THE AREA WITH PATCHES
OF LOW VFR STRATOCU PERSISTING ACROSS SOUTH-CENTRAL ARIZONA. THE
STRATOCU DECK AT 4-5K FEET WILL AFFECT THE PHOENIX TERMINALS FOR A
GOOD PORTION OF THIS MORNING AND POSSIBLY INTO THE AFTERNOON. CIGS
FOR THIS AFTERNOON AND EVENING WILL RISE TO AROUND 6K FEET AND
SHOULD BE MORE SCATTERED. LIGHT WINDS WILL DOMINATE THROUGH THE
PERIOD AND GENERALLY FOLLOW TYPICAL DIURNAL WIND PATTERNS.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
CLEAR TO MOSTLY CLEAR SKIES AND LIGHT WINDS WILL LAST THROUGH AT
LEAST FRIDAY MORNING. NO AVIATION IMPACTS EXPECTED.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SATURDAY THROUGH WEDNESDAY...
A REBOUND IN TEMPERATURES WILL HAPPEN THIS WEEKEND INTO NEXT WITH
HIGHS REACHING NORMALS BY NEXT MONDAY AND WARMING EVEN FURTHER BY
NEXT WEDNESDAY. MINIMUM RELATIVE HUMIDITIES OF 15 TO 30 PERCENT ON
SATURDAY WILL GRADUALLY LOWER THROUGH THE PERIOD WITH VALUES IN THE
TEENS TO LOWER 20S FOR NEXT TUESDAY AND WEDNESDAY. WINDS WILL REMAIN
LIGHT THROUGH THE PERIOD UNDER STRONG HIGH PRESSURE.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...FREEZE WARNING UNTIL 9 AM MST THIS MORNING AZZ020>022-026>028.
FREEZE WARNING FROM 11 PM THIS EVENING TO 9 AM MST FRIDAY
AZZ020>023-026>028.
WINTER STORM WARNING UNTIL 6 AM MST EARLY THIS MORNING ABOVE
3500 FEET FOR AZZ024.
CA...FREEZE WARNING UNTIL 8 AM PST THIS MORNING CAZ033.
FREEZE WARNING FROM 10 PM THIS EVENING TO 8 AM PST FRIDAY CAZ033.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH
AVIATION....KUHLMAN
FIRE WEATHER...KUHLMAN
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
335 AM MST THU JAN 1 2015
...FREEZING TEMPERATURES LIKELY AT MANY LOWER DESERT LOCATIONS THIS
MORNING AND AGAIN TONIGHT...
.SYNOPSIS...
THE STRONG AND VERY COLD STORM SYSTEM THAT BROUGHT RAIN AND LOW
ELEVATION SNOWFALL TO THE DESERT SOUTHWEST WILL SLOWLY MOVE OFF TO
THE EAST TODAY. IN ITS WAKE...WELL BELOW NORMAL TEMPERATURES WILL
PERSIST ACROSS THE REGION THROUGH SUNDAY. HIGH PRESSURE BUILDING IN
FROM THE WEST WILL BRING A GRADUAL WARMING TREND FRIDAY THROUGH THE
MIDDLE PART OF NEXT WEEK.
&&
.DISCUSSION...
WELL-DEFINED VORT MAX CONTINUES TO SLIDE EASTWARD ACROSS NORTHERN AZ
EARLY THIS MORNING. ELONGATED BAND OF COOLER CLOUDS ASSOCIATED WITH
STRONG JET AND VORTICITY-FORCED ASCENT HAS PUSHED STEADILY EASTWARD
INTO NORTHERN AND EASTERN AZ. LAST GASP OF PRECIPITATION ACROSS THE
PHOENIX AREA WAS IN THE FORM OF LIGHT SNOW ACROSS MANY SPOTS JUST
BEFORE MIDNIGHT. EVEN IN THE LOWEST ELEVATIONS OF THE VALLEY...A MIX
OF RAIN AND SNOW WAS OBSERVED.
FOR THIS MORNING...GLOBAL AND HI-RES GUIDANCE INCLUDING THE HRRR ARE
IN GOOD AGREEMENT THAT LIGHT SNOW WILL CONTINUE TO TAPER OFF ACROSS
SOUTHERN GILA COUNTY WITH LITTLE ADDITIONAL ACCUMULATION. END TIME
OF THE WINTER STORM WARNING FOR THE HIGHER ELEVATIONS OF SOUTHERN
GILA COUNTY HAS BEEN TRIMMED TO 6 AM. WITH A SUBSIDENT FLOW
EXPECTED...POPS WERE ALSO LOWERED ACROSS THESE AREAS AND IN THE
LOWER DESERTS THROUGH THIS AFTERNOON. NEVERTHELESS...SCATTERED
CLOUDS WILL WRAP AROUND THE DEPARTING LOW PRESSURE SYSTEM PRODUCING
PARTLY CLOUDY SKIES AND ISOLATED SNOW FLURRIES.
AFTER A VERY COLD MORNING...TEMPERATURES WILL AGAIN STRUGGLE TO
REACH THE 50 DEGREE MARK...MARKING THE COLDEST MAX TEMPERATURES
SINCE THE FREEZING EVENT IN JANUARY 2013. THE COLD AFTERNOON WILL
SET THE STAGE FOR ANOTHER COLD NIGHT. MOSTLY CLEAR SKIES AND LIGHT
WINDS IN THE WAKE OF THE DEPARTING LOW PRESSURE SYSTEM WILL PROMOTE
RADIATIONAL COOLING AND A FREEZE WARNING REMAINS IN EFFECT FOR MUCH
OF THE LOWER DESERTS INCLUDING THE PHOENIX AREA. LATEST STATISTICAL
GUIDANCE HAS TRENDED SOMEWHAT COLDER AND IMPERIAL COUNTY WAS ALSO
ADDED TO THE WARNING.
OPERATIONAL MODELS REMAIN IN EXCELLENT AGREEMENT THROUGH THE
EXTENDED...INDICATING THAT PACIFIC HIGH PRESSURE WILL BUILD ACROSS
THE REGION. THIS WILL RESULT IN DRY CONDITIONS ALONG WITH INCREASING
THICKNESSES AND A GRADUAL WARMING TREND THROUGH THE MIDDLE OF NEXT
WEEK. HOWEVER...TEMPERATURES WILL REMAIN BELOW NORMAL THROUGH MONDAY
WITH COLD MORNINGS. A FREEZE WARNING MAY ULTIMATELY BE NEEDED FOR
PORTIONS OF THE AREA AGAIN SATURDAY MORNING.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA AND KSDL...
BROAD AREA OF LOWER LEVEL STRATUS COVERS MUCH OF THE LOWER CENTRAL
AZ DESERTS...WITH VARYING LAYERS AND BREAKS IN THE CLOUD DECK. WILL
LOOK FOR PERIODS OF MVFR CIGS AT PHX AREA TERMINALS THROUGH THE
EVENING...BUT CONDITIONS WILL NOT REMAIN AS SOCKED IN AS THEY WERE
DURING THE DAY. CIGS AROUND THE 5500-6000FT LAYER MAY HOLD THROUGH
SUNRISE AND TERRAIN OBSCURATIONS WILL ALSO PERSIST. WX RADAR SCOPES
STILL SHOW SCATTERED LIGHT SHOWERS OVER EASTERN PORTIONS OF THE PHX
METRO THAT MAY PASS OVER THE TERMINALS...BRIEFLY REDUCING CIGS BUT
NOT AMOUNTING TO MUCH BY WAY OF WETTING TARMAC/APRON SFCS. WESTERLY
WINDS 10KTS OR LESS WILL HOLD INTO THE OVERNIGHT HOURS...BEFORE
ATTEMPTING TO SWITCH TO EASTERLY NEAR OR AFTER 01/12Z...OTHERWISE
BECOME VARIABLE WITH SPEEDS 6 KTS OR LESS.
GIVEN THE COOLING AIRMASS AND ELEVATED DEWPOINTS...EXPECT ATLEAST
VCFG NEAR KIWA AND KSDL BY SUNRISE...WITH LESS CONFIDENCE OF ANY
SUBSTANTIAL FOG DEVELOPING NEAR KPHX.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
PATCHES OF LOW TO MID LEVEL CIGS CONTINUE TO CIRCULATE AROUND THE
UPPER LOW THAT HAS NOW PUSHED INTO NW AZ. CIGS GNLY WILL HOLD ABOVE
8KFT FOR THE REMAINDER OF THE EVENING AS SOME DRIER AIR CONTINUES TO
WORK INTO THE REGION. WINDS TO HOLD NORTHERLY HEADINGS WHILE
SUBSIDING IN THEIR ELEVATED SPEEDS...OCCASIONALLY BECOMING NEAR CALM
AS SKIES CLEAR BY SUNRISE.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
FRIDAY THROUGH TUESDAY...
MOSTLY CLEAR SKIES AND MUCH BELOW NORMAL TEMPERATURES ARE EXPECTED
FRIDAY THROUGH SUNDAY...WARMING SOMEWHAT MONDAY AND TUESDAY. MINIMUM
RELATIVE HUMIDITIES FRIDAY WILL RANGE FROM 20 PERCENT IN SOUTHEAST
CALIFORNIA TO 50 PERCENT IN SOUTHERN GILA COUNTY...DECREASING MONDAY
AND TUESDAY BY 15 TO 20 PERCENT RANGE AREA-WIDE. LIGHT WIND.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...FREEZE WARNING UNTIL 9 AM MST THIS MORNING AZZ020>022-026>028.
FREEZE WARNING FROM 11 PM THIS EVENING TO 9 AM MST FRIDAY
AZZ020>023-026>028.
WINTER STORM WARNING UNTIL 6 AM MST EARLY THIS MORNING ABOVE
3500 FEET FOR AZZ024.
CA...FREEZE WARNING UNTIL 8 AM PST THIS MORNING CAZ033.
FREEZE WARNING FROM 10 PM THIS EVENING TO 8 AM PST FRIDAY CAZ033.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH
AVIATION....NOLTE
FIRE WEATHER...VASQUEZ
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
502 AM MST THU JAN 1 2015
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 406 AM MST THU JAN 1 2015
SATELLITE AND RADAR SIGNATURES FINALLY SHOWING SOME PROMISE ACROSS
OUR SOUTHWEST CWA EARLY THIS MORNING. THIS IS A LATER START THAN
EXPECTED. SNOW TOTALS ARE LIKELY GOING TO BE LESS THAN EARLIER
THOUGHT...BUT LOOKING AT BLANDING WEB CAM...THIS STORM IS LIKELY
TO IMPACT TRAVEL ON THIS HOLIDAY OVER A GOOD CHUNK OF OUR CWA. THE
NEXT 6 TO 12 HOURS WILL BE THE MOST ACTIVE PERIOD ACROSS OUR CWA
AND WILL LET THE CURRENT HIGHLIGHTS RUN.
LARGE SCALE ASCENT IS INCREASING SIGNIFICANTLY OVER THE 4 CORNERS AS
THE UPPER JET MAX IS FINALLY REFORMING ON THE DOWNSTREAM SIDE OF THE
CYCLONE AND ALLOWING IT TO SLOG EASTWARD. THE CYCLONIC JET IS AIDING
IN THE STRONG UPWARD MOTION AND AN INVERTED TROF EXTENDING FROM THE
4 CORNERS TO THE CENTRAL MOUNTAINS IS AIDING IN LOW LEVEL
CONVERGENCE OVER SOUTHEAST UTAH AND SOUTHWESTERN COLORADO THIS
MORNING. QG FIELDS SUGGEST THE ASCENT INCREASES AND TIGHTENS THROUGH
MID MORNING NEAR THE 4 CORNERS...THEN RELAXES THROUGH THE DAY AS MID
LEVEL CIRCULATION IS ELONGATED BY THE RETREATING JET MAX. SOUTHERLY
OROGRAPHICS ARE LIKELY TO AID IN FOCUSING HEAVIER SNOW IN THE
FOOTHILLS AND HILLS OF THE SOUTHERN SAN JUANS WITH THE LOW JUST TO
THE WEST THIS MORNING. UNFORTUNATELY INSTABILITY WILL NOT BE AS
STRONG AS ANTICIPATED 24 HOURS AGO. BOTH MODELS SHOW BOTH A MID
LEVEL AND LOW LEVEL CIRCULATION RUNNING ALONG THE INVERTED TROUGH
AXIS AND THIS SHOULD BRING SNOW ACROSS THE CENTRAL MOUNTAINS AND
VALLEYS THROUGH THE EARLY EVENING...THOUGH OROGRAPHICS SLACKEN LATER
TODAY. DID BOOST POPS AND SNOW AMOUNTS ACROSS THE WEST ELKS...ELKS
AND TOP OF THE MESA. LOOKING AT THE LATEST BUFKIT SOUNDING DATA AND
SREF PLUMES ALSO THINK SOME HIGH VALLEY LOCATIONS MAY PICK UP SOME
SNOW THIS AFTERNOON. THIS INCLUDES ASPEN WHICH IS NEAR THE PASSING
SURFACE LOW AND GUNNISON WHERE AMOUNTS WILL GENERALLY BE 2-3 INCHES.
DECIDED AGAINST AN ADVISORY AT THIS TIME WITH THE HIGH PASSES
CLOSED...THE ONLY CONCERN WOULD BE AT MCCLURE BUT CONFIDENCE TOO LOW
ATTM. THE LOW CONTINUES TO ELONGATE TONIGHT WITH THE GFS AND NAM NOW
TAKING DIFFERENT CAMPS ON WHERE THE MAIN CIRCULATIONS REMAIN IN THIS
AREA OF LOW PRESSURE. GFS DEVELOPS ONE SOUTHERN UTAH AND THE NAM THE
PLAINS OF COLORADO. EITHER WAY AN EASTERLY COMPONENT TO THE WINDS
OCCUR WHICH MAY KEEP SOME ISOLATED SHOWERS GOING WITH RESIDUAL
MOISTURE AROUND FOR THE MOST PART THIS STORM IS DONE BY MIDNIGHT.
THE DENDRITIC LAYER DRIES OUT IN THE FAVORED GFS SOLUTION AND THIS
LEAD TO A QUIET BUT COLD FRIDAY AND NEW SNOW HOLDS THE INVERSION IN.
TEMPERATURES REMAIN COLD AND WELL BELOW NORMAL.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 406 AM MST THU JAN 1 2015
THE NEXT PROGRESSIVE SHORT WAVE ARRIVES FROM THE NORTHWEST WITH
INCREASING CLOUDS ACROSS THE NORTH ON FRIDAY NIGHT. THE BEST
DYNAMICAL FORCING ARRIVES SATURDAY...COINCIDING WITH SOME MID
LEVEL COLD ADVECTION. THE NORTHERN COLORADO MOUNTAINS WILL BE THE
PRIMARY BENEFICIARY FOR SNOW...BUT COULD EXTEND AS FAR SOUTH AS
THE NWRN SAN JUAN MOUNTAINS. MODEL QPF AMOUNTS SUGGEST SNOW
AMOUNTS MOSTLY IN THE 5-10 INCH RANGE FOR THE NWRN COLORADO
MOUNTAINS. A LITTLE CONCERN THAT THE TRAPPED COLD AIR AND SNOW TO
LIQUID RATIOS OF 20:1 OR HIGHER COULD ENHANCE SNOW AMOUNTS. ABOVE
TIMBERLINE OR EXPOSED AREAS WILL BE PRONE FOR BLOWING SNOW AS
700 MB GRADIENT FLOW WILL BE AROUND 30 KTS. WITH THE MODERATELY
DEEP SURFACE LOW TRACKING WELL NORTH OF COLORADO (ACROSS MONTANA
AND THE DAKOTAS)...THIS REDUCES THE LIKELIHOOD OF SIGNIFICANT
HEAVY SNOW (MEANING 12+ INCHES) FOR NORTHWEST COLORADO. THE SNOW
THREAT DECREASES FARTHER WEST AND SOUTH.
PACIFIC MOISTURE CONTINUES TO STREAM OVER THE NRN COLORADO
MOUNTAINS FOR SOME OROGRAPHIC SNOWFALL INTO MONDAY. THIS MOISTURE
FEED IS NOT DEEP WITH SPOTTY LIGHT AMOUNTS FOR NORTHERN ROUTT
COUNTY.
THE PASSAGE OF SATURDAYS SHORT WAVE IS STRONG ENOUGH TO CAUSE SOME
MIXING AND WEAKEN TEMPERATURE INVERSIONS. A WARMING TREND SHOULD
PERSIST INTO NEXT WEDNESDAY. THE RATE OF WARMING TENDS TO BE
PROBLEMATIC SINCE MANY VALLEYS ARE SNOW COVERED...BUT THE PATTERN
DOES NOT FAVOR A STAGNANT AIR MASS WITH WNW FLOW PREVAILING OVER
THE FORECAST AREA (WITH THE MAIN JET NORTH OF COLORADO). THE
RIDGE AXIS WILL BE POSITIONED OVER THE WEST COAST STATES AND NOT
OVERHEAD...SO THIS SHOULD RESULT IN SOME TEMPERATURE MODERATION.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 502 AM MST THU JAN 1 2015
WIDESPREAD -SN (OR OCCASIONAL MODERATE SNOW) WITH IFR CIGS ACROSS
ACROSS SERN UTAH AND SWRN COLORADO TODAY. THE I70 CORRIDOR OR
KGJT...KRIL...KASE...KEGE WILL BE ON THE NRN FRINGE OF THIS REGION
OF SNOW. CURRENT HRRR MODEL KEEPS LIGHT SNOW FROM IMPACTING THESE
TAF SITES WITH THE EXCEPTION OF KASE. KASE MAY TEMPORARILY FALL
BELOW ILS BREAKPOINTS THIS AFTERNOON AND INTO THE EVENING HOURS.
SLOW IMPROVEMENT AFTER 00Z WITH LIGHT TO MODERATE SNOW DECREASING
ACROSS SW COLORADO.
VFR IS EXPECTED TO PREVAIL NORTH OF INTERSTATE 70.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER WEATHER ADVISORY UNTIL MIDNIGHT MST TONIGHT FOR COZ018-
020.
WINTER STORM WARNING UNTIL MIDNIGHT MST TONIGHT FOR COZ019-
021>023.
UT...WINTER STORM WARNING UNTIL MIDNIGHT MST TONIGHT FOR UTZ028.
WINTER STORM WARNING UNTIL 6 PM MST THIS EVENING FOR UTZ022-029.
&&
$$
SHORT TERM...15
LONG TERM...PF
AVIATION...PF
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
426 AM MST THU JAN 1 2015
.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 425 AM MST THU JAN 1 2015
A CLOSED MID-UPPER LOW OVER NORTH CENTRAL ARIZONA AT 09Z
WILL BECOME INCREASINGLY ELONGATED ACROSS COLORADO AS IT SHIFTS
EASTWARD ACROSS THE FOUR CORNERS REGION TODAY. AT THE SFC...AN
EXPANSIVE AREA OF HIGH PRESSURE LINKED TO AN ARCTIC AIRMASS COVERS
THE GREAT PLAINS. MODELS SHOW PRECIP FORMING NORTHEASTWARD ALONG THE
700-500MB TROUGH DEFORMATION AXIS REACHING THE SOUTHWEST CORNER OF
THE FORECAST AREA BY LATE THIS MORNING. FORWARD SPEED OF CLOUD
SHIELD WRAPPING AROUND THE UPPER LOW WILL LIKELY ARRIVE SOONER THAN
THAT BASED ON SPEED OF MOTION MEASUREMENTS USING IR SATELLITE
IMAGERY. EXCEPT FOR A BAND OF CIRRUS CLOUD STREAKING NEWRD ACRS THE
SOUTHEAST CORNER OF THE CWA...SKIES AT THE PRESENT TIME WERE CLEAR
ACROSS N-CENTRAL/NORTHEAST COLORADO. HRRR AND RAP MDLS SHOW LIGHT
SNOWFALL/QPF OVER THE MOSQUITO...TEN MILE AND SOUTHERN FRONT RANGE
MTNS BY MIDDAY...THEN SPREADING NORTHWARD OVER THE FRONT RANGE AND
EASTWARD ALONG THE PALMER DIVIDE AND SOUTHERN SECTIONS OF THE I-25
URBAN CORRIDOR DURING THE LATE AFTERNOON HOURS. FORECASTED PCPN AMTS
IN THIS AREA RANGE FROM A TRACE TO 0.20 INCH BY 00Z/FRI...AND SNOW
AMOUNTS FROM A TRACE TO 3 INCHES. THE HEAVIER AMTS WILL BE FOUND
OVER THE HIGHER TERRAIN SURROUNDING SOUTH PARK AND ALONG HIGHER
PORTIONS OF THE PALMER DIVIDE IN DOUGLAS COUNTY. BY EVENING WITH THE
UPPER LOW WEAKENING AND TURNING SOUTHEAST AWAY FROM COLORADO...
SHOULD SEE A MARKED DECREASE IN SNOWFALL ACROSS SOUTHERN SECTIONS OF
THE CWA BY MID TO LATE EVENING. AS THIS IS TAKING PLACE...MODELS
NAMELY THE NAM...SHOW A SECONDARY AREA OF SNOWFALL DEVELOPING OVER
THE NORTHERN FRONT RANGE MTN AND NRN I-25 URBAN CORRIDOR AS A RESULT
OF OROGRAPHIC LIFT AND COLD ADVECTION OCCURRING ON THE NORTHERN
FRINGE OF THE UPPER TROUGH. COULD SEE LOCAL SNOW AMTS UP TO AN INCH
OR SO OVER HIGHER ELEVATIONS OF THE NRN FRONT RANGE AND POSSIBLY A
QUARTER INCH OR SO ON THE NEARBY PLAINS BEFORE SKIES CLEAR AROUND
10Z/FRI.
HIGH TEMPERATURES TODAY ARE EXPECTED TO BE A FEW DEGS COOLER THAN
YESTERDAY DUE IN LARGE PART TO THE LACK OF SUNSHINE THIS AFTERNOON.
WHEREAS TEMPS TONIGHT NOT AS COLD AS PREVIOUS NIGHTS BECAUSE OF
CLOUD COVER AND AS A RESULT OF MIXED BNDRY LAYER DUE TO PCPN IN
THE AREA.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 425 AM MST THU JAN 1 2015
THE UPPER LOW NOW OVER ARIZONA WILL WEAKEN AND BECOME ELONGATED
ACROSS COLORADO EARLY FRIDAY MORNING. A PIECE OF THIS LOW
SEPARATES FROM THE PARENT SYSTEM WHICH WILL REMAIN OVER NEW
MEXICO THROUGH FRIDAY NIGHT. STILL EXPECT A FAIR AMOUNT OF
CLOUDINESS FRIDAY AM BUT ANY PRECIP WILL HAVE FINISHED DURING THE
EARLY MORNING HOURS. TEMPERATURES WILL STILL REMAIN IN THE 30S
ACROSS LOWER ELEVATIONS.
THE MAIN LOW OVER NEW MEXICO IS PROGGED TO LIFT NORTHEAST INTO THE
CENTRAL PLAINS ON SATURDAY WHILE A SECONDARY WAVE MOVES RAPIDLY
SOUTHEAST FROM THE NORTHERN ROCKIES. AN ACCOMPANIED COLD FRONT
EXPECTED TO BLAST ACROSS THE NORTHEAST PLAINS AROUND MIDDAY
SATURDAY WITH A BRIEF PERIOD OF UPSLOPE FLOW ON SATURDAY AFTERNOON
AND QUICK SHOT OF QG UPWARD FORCING AS STRONG JET MOVES ACROSS
COLORADO. WILL CONTINUE TO INCREASE POPS SLIGHTLY DURING THIS
PERIOD AS CONDITIONS CONTINUE TO LOOK MORE FAVORABLE FOR A SHOT OF
SNOW OVER MOUNTAINS AND PLAINS.
FOR SUNDAY AND INTO EARLY NEXT WEEK....THE PATTERN WILL SHIFT TO
A STRONG NORTHWEST FLOW ALOFT. THIS WILL RESULT IN INCREASING
WINDS OVER MOUNTAINS AND EAST SLOPES WITH A DOWNSLOPE WARMING
TREND OVER THE NORTHEAST PLAINS. GIVEN THE FLOW PATTERN EXPECT
SOME SNOW SHOWERS TO CONTINUE OVER THE HIGHER ELEVATIONS OF THE
NORTHERN MOUNTAINS BUT ONLY MINIMAL ACCUMULATIONS.
&&
.AVIATION...(FOR THE TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 425 AM MST THU JAN 1 2015
VFR CONDITIONS AT DENVER AREA TERMINALS THIS MORNING WILL
DETERIORATE TO MVFR CONDITIONS WITH LOWERING CIGS TO AROUND
4000-5000 FT AGL AND SCATTERED AREAS OF LIGHT SNOWFALL REDUCING
VSBYS TO 3-5 MILES AFTER 4 PM MST. KAPA COULD POSSIBLY SEE ILS
CONDITIONS WITH CIGS LOWERING TO BELOW 3000 FEET AGL AND VSBYS
BELOW 3 MILES WITH LIGHT TO MODERATE SNOWFALL LATE THIS AFTERNOON
AND EARLY THIS EVENING. CONDITIONS SHOULD IMPROVE AT ALL
TERMINALS AFTER 04Z THIS EVENING WITH CLEARING SKIES BEFORE
MORNING. LIGHT S-SWLY WINDS EARLY TO MID-MORNING EXPECTED TO
BECOME W-NWLY BY LATE MORNING BEFORE RETURNING TO A S-SWLY
DIRECTION THIS EVENING. MOST AREAS SHOULD SEE WIND SPEEDS
REMAINING UNDER 12 KTS.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BAKER
LONG TERM...ENTREKIN
AVIATION...BAKER
AREA FORECAST DISCUSSION
NWS MIAMI FL
1004 AM EST THU JAN 1 2015
.UPDATE...
SCATTERED SHOWERS REMAIN THIS MORNING MAINLY ACROSS THE ATLANTIC
WATERS OFF THE PALM BEACHES. WEAK STATIONARY FRONT REMAINS DRAPED
ACROSS THE AREA THIS MORNING CONTRIBUTING TO THE SHOWERS AND
EXTENSIVE CLOUDINESS. LATEST VISIBLE SATELLITE DOES HOWEVER SHOW
CLOUD SHIELD BEGINNING TO ERODE ACROSS BROWARD AND MIAMI-DADE
COUNTIES LATE THIS MORNING. THIS HAS ALLOWED TEMPERATURES TO SURGE
INTO THE MID TO UPPER 70S ALREADY. HRRR CONTINUES TO DEPICT
ISOLATED LIGHT SHOWERS ACROSS MAINLY THE EASTERN HALF OF THE AREA
INTO THE EARLY AFTERNOON HOURS...SO KEPT SLIGHT CHANCE POP GOING.
THE REMAINDER OF THE FORECAST LOOKS ON TRACK AT THIS TIME. UPDATE
SENT.
&&
.PREV DISCUSSION... /ISSUED 649 AM EST THU JAN 1 2015/
AVIATION...
WEAK LOW PRESSURE OVER SOUTHWEST FLORIDA IN COMBINATION WITH
DIFFUSE FRONT NEAR LAKE OKEECHOBEE KEEPING PLENTY OF CLOUDS AND
IFR/MVFR CONDITIONS IN BOTH CEILINGS AND VISIBILITY (MIXTURE OF
SHOWERS AND FOG) ACROSS SOUTH FLORIDA THIS MORNING. BAND OF
SHOWERS NEAR FLL/PBI AREA HAS STAYED MOSTLY OFFSHORE WITH LIGHT
SHOWERS REACHING THE TERMINAL SITES. EXPECT THESE CONDITIONS TO
PERSIST THROUGH ABOUT 15Z, FOLLOWED BY SLOW IMPROVEMENT AS THE LOW
PRESSURE MOVES INTO THE GULF AND THE FRONT CONTINUES TO DISSIPATE.
BY 18Z, EXPECT VFR CONDITIONS TO ONCE AGAIN PREVAIL WITH WIND FLOW
BECOMING LIGHT SE (EXCEPT SEA BREEZE AT KAPF). THIS WILL ALSO
INTRODUCE SLIGHTLY DRIER AIR TO THE AREA WITH COVERAGE OF SHOWERS
DECREASING AS A RESULT. BY THIS EVENING, MOST OF AREA SHOULD BE
FREE OF PRECIPITATION. SOME FOG/LOW CLOUDS COULD ONCE AGAIN FORM
LATE TONIGHT AFTER 06Z, MAINLY INTERIOR AND WESTERN SECTIONS OF
THE PENINSULA. /MOLLEDA
PREV DISCUSSION... /ISSUED 319 AM EST THU JAN 1 2015/
DISCUSSION...
A COMPACT AND WEAK MESOSCALE LOW PASSED SOUTHWARD ACROSS THE
ATLANTIC WATERS YESTERDAY ALONG PALM BEACH COUNTY THEN DRIFTED
WESTWARD ACROSS THE SOUTH FLORIDA PENINSULA EARLY THIS MORNING.
DURING THE EARLY MORNING HOURS SCATTERED SHOWER ACTIVITY OCCURRED
WITH THE GREATEST COVERAGE ACROSS NORTHERN BROWARD COUNTY AND
ACROSS PALM BEACH COUNTY AND ADJACENT ATLANTIC WATERS...WITH THIS
COVERAGE CONTINUING.
THE COMBINATION OF LOW STRATUS AND/OR FOG WILL CONTINUE EARLY THIS
MORNING WITH MOST OF THE COVERAGE EXPECTED ACROSS MIAMI DADE
COUNTY AND SOUTHERN HALF OF BROWARD COUNTY.
THE WILL BE A CHANCE OF RIP CURRENTS TODAY BUT MAINLY EXPECTED
ACROSS THE PALM BEACH COUNTY BEACHES.
THE LATEST MODEL GUIDANCE INDICATES A WEAK SURFACE TROUGH AND
DIFFUSE FRONTAL BOUNDARY CONTINUING ACROSS THE SOUTH FLORIDA
PENINSULA TODAY WITH HIGH PRESSURE THEN STARTING TO BUILD BACK
ACROSS THE REGION THIS EVENING AND OVER NIGHT. THE FORECAST FOR
TODAY IS FOR ISOLATED TO SCATTERED SHOWERS MAINLY ACROSS THE
ATLANTIC WATERS AND THE ATLANTIC METRO AREAS WITH THE GREATEST
COVERAGE CONTINUING TO BE ACROSS BROWARD AND PALM BEACH COUNTIES
AND THE ADJACENT ATLANTIC WATERS. A DRYING TREND IS THEN FORECAST
WITH THE MODEL CONSENSUS INDICATING SOUTHERLY LOW LEVEL FLOW
BRINGING IN DRIER AIR INTO THE REGION TONIGHT INTO FRIDAY. BY
FRIDAY HIGH PRESSURE WILL PREVAIL ACROSS THE REGION WITH A SURFACE
RIDGE EAST OF THE FLORIDA PENINSULA AND AT THE MID TO UPPER LEVELS
A LARGE AMPLITUDE RIDGE BECOMING ESTABLISHED ACROSS THE FLORIDA
STRAITS. THIS PATTERN WILL MORE OR LESS PERSIST THROUGH THE
UPCOMING WEEKEND...WITH STABLE WEATHER CONDITIONS AND INCREASINGLY
WARMER TEMPERATURES PREVAILING ACROSS THE REGION.
FOR THE EXTENDED FORECAST...THE GLOBAL MODEL CONSENSUS INDICATES
THE NEXT COLD FRONT ENTERING THE FLORIDA PANHANDLE AND NORTHERN
FLORIDA ON SUNDAY AND THEN INTO CENTRAL FLORIDA ON MONDAY AND APPROACHING
LAKE OKEECHOBEE AND WEAKENING MONDAY NIGHT. BY TUESDAY THE MODELS
START TO DIVERGE IN THEIR SOLUTIONS...BUT OVER ALL NO SIGNIFICANT
IMPACTS ARE FORECAST THUS FAR FOR SOUTH FLORIDA WITH THE FORECAST
INDICATING JUST A GRADUAL COOL DOWN AND POSSIBLY SOME ISOLATED
SHOWER ACTIVITY. /BD
MARINE...
THE LOCAL PRESSURE GRADIENT ACROSS THE REGION EARLY THIS MORNING
IS SUCH THAT WINDS IN THE 15 TO 20 KNOT RANGE ARE FORECAST ACROSS
THE ATLANTIC WATERS MAINLY TO THE EAST OF PALM BEACH COUNTY AND
ACROSS THE OFF SHORE WATERS...WITH AN SCEC FOR THESE WATERS TODAY.
THE PRESSURE GRADIENT AND RESULTANT WINDS EAST OF PALM BEACH
COUNTY IS FORECAST TO RELAX TONIGHT INTO FRIDAY. FOR THE REMAINDER
OF THE OF THE FORECAST...WINDS AND SEAS ACROSS THE GULF AND
ATLANTIC WATERS ARE FORECAST TO REMAIN WELL BELOW ADVISORY LEVELS.
/BD
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 80 70 81 73 / 30 10 10 10
FORT LAUDERDALE 80 72 81 73 / 20 10 10 10
MIAMI 81 71 81 73 / 20 10 10 10
NAPLES 79 67 81 68 / 10 10 10 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
UPDATE...10/CD
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
937 AM EST Thu Jan 1 2015
.Near Term [Through Today]...
Morning satellite imagery shows mid and high clouds streaming
eastward ahead of an upper level trough over the southwest states.
There is also an area of low clouds across portions of the southeast
big bend and south-central Georgia. In between these two areas
around Tallahassee, skies are mostly sunny. Some of the hi-res
guidance such as the 11z HRRR keeps low clouds around the southeast
big bend well into the afternoon hours, and if that occurs we will
end up with another interesting high temperature distribution across
the area today. It is possible that the warmest temperatures today
will be across the central areas away from the high clouds to the
west and low clouds to the east. Clouds will increase across the
entire area tonight from west to east ahead of a developing warm
front across the northern Gulf coast.
&&
.Aviation...
[Through 12z Friday] VFR conditions are expected to prevail for
today across most of the area with light winds. The exception will
be around VLD which will be on the edge of an MVFR cloud deck
through this morning. MVFR conditions may return to the entire area
tonight as moisture increases to the north of a developing warm
front.
&&
.Prev Discussion [423 AM EST]...
.Short Term [Tonight Through Saturday]...
There will be an upper level ridge over the region during this time.
At the sfc, a weak high will be over the Southeast on Friday. By
Saturday, a low from the Gulf will move through the lower MS River
Valley. This low will strengthen quickly as it is supported in the
upper levels by a deep trough moving out of the Southwest states. A
warm front will pass through on Saturday bringing a chance for
rain well ahead of the low, particularly in the northwestern part of
the CWA. Expect cloudy skies with ample moisture from the Atlantic
on Friday, then from the Gulf when winds become southerly on
Saturday. Lows will be in the 40s on Friday morning and 50s on
Saturday morning. Highs will range from the mid 60s to the lower 70s
on Friday. Highs will be in the 70s on Saturday.
.Long Term [Saturday Night Through Thursday]...
By Sunday morning a strong low at the sfc will be over the Great
Lakes region. A cold front will extend all the way to the Gulf
Coast. Rain with some thunder is expected Sunday into Sunday night
as the front moves through. On Monday high pressure will move in
from the west bringing cooler, drier air. No rain is expected for
the rest of the period as high pressure dominates the region. Temps
will shift to seasonal levels after FROPA (50s/60s for highs and
30s/40s for lows).
.Marine...
Light to moderate northeasterly winds will turn southerly by
Saturday. Cautionary level winds are possible on Saturday ahead of a
cold front. Advisory level winds are possible on Monday after the
cold front passes.
.Fire Weather...
No fire weather concerns are expected over the next several days as
afternoon relative humidities will continue to remain well above any
Red Flag concerns.
.Hydrology...
Most of the rivers across the region are slowly subsiding after last
week`s heavy rainfall. Even the Withlacoochee river near Pinetta has
leveled off, and will likely drop into action stage later today.
While rivers outside the lower Withlacoochee/Suwannee area will
continue to fall to below flood stage, this upcoming weekend`s
rainfall totals may not be quite as high as earlier thought,
especially where the current stages and potential problems would be
the highest. At present, storm total QPF is expected to range from
around 0.5 inches over the Suwannee and Withlacoochee basins, with
a gradual increasing trend to the N and W. The highest totals of
1.5" to 2.5" appear likely over far western portions of the FL
Panhandle as well as SE AL, which fortunately contain the basins
which can handle those amounts of rainfall over a short period of
time without too many concerns.
Detailed information pertaining to current river stages and
forecasts can be found at: http://water.weather.gov/ahps.
&&
.Preliminary Point Temps/PoPs...
Tallahassee 66 48 70 57 78 / 10 20 30 20 20
Panama City 63 53 68 61 74 / 0 20 40 30 40
Dothan 59 46 63 55 74 / 0 20 60 40 50
Albany 59 44 64 52 74 / 0 20 50 30 40
Valdosta 62 46 69 56 78 / 10 10 30 20 20
Cross City 63 50 75 58 81 / 10 10 30 20 10
Apalachicola 64 54 67 62 73 / 0 20 30 20 30
&&
.TAE Watches/Warnings/Advisories...
FL...None.
GA...None.
AL...None.
GM...None.
&&
$$
NEAR TERM...DVD
SHORT TERM...MCDERMOTT
LONG TERM...MCDERMOTT
AVIATION...DVD
MARINE...MCDERMOTT
FIRE WEATHER...GOULD
HYDROLOGY...GOULD
AREA FORECAST DISCUSSION
NWS CARIBOU ME
715 AM EST THU JAN 1 2015
.SYNOPSIS...
A WARM FRONT WILL LIFT ACROSS THE REGION TODAY. AN ARCTIC FRONT
WILL SWEEP THROUGH THE REGION LATER TONIGHT INTO FRIDAY. HIGH
PRESSURE WILL BUILD INTO THE REGION FROM CANADA FRIDAY NIGHT INTO
SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
715 AM UPDATE...ADJUSTED THE HRLY TEMPERATURES AND SKY CONDITIONS
TO MATCH THE LATEST OBS.11Z SURFACE ANALYSIS SHOWED THE WARM FRONT
LIFTING NORTH W/HINTS OF A WEAK LOW DEVELOPING THE FRONT ALONG THE
HANCOCK-WASHINGTON COUNTY COAST. POPS WERE PUSHED FURTHER EAST TO
ACCOUNT FOR SOME LIGHT SNOW THIS MORNING AS THE RADAR WAS SHOWING
SOME LIGHT RETURNS. NO OTHER CHANGES ATTM.
LATEST SURFACE ANALYSIS SHOWED WARM FRONT LIFTING N ACROSS THE
PINE TREE STATE. SOME LIGHT PRECIP IN THE FORM OF SOME LIGHT SNOW
ACROSS THE IMMEDIATE COAST W/MOST OF PRECIP OFFSHORE. FURTHER N,
THE RADAR SHOWED SOME VERY LIGHT RETURNS IN THE FORM OF SOME
FLURRIES. TEMPERATURES WERE SLOWLY RISING THIS MORNING AND WILL
CONTINUE TO DO SO TODAY W/THE WARM FRONT PASSAGE. PERIODS OF LIGHT
SNOW/SNOW SHOWERS EXPECTED ACROSS THE NORTH AND WEST AND RIGHT
ALONG THE DOWNEAST COAST. THE NAM AND RAP GUIDANCE POINT TO SOME
STEEPENING LAPSE RATES OF 7.0C/KM FROM 850-700MBS W/THE WARM
FRONT. THE BEST CHANCE FOR ANY ACCUMULATING SNOW WILL BE ACROSS
THE FAR W AND NW W/AN INCH POSSIBLE. TEMPERATURES ARE EXPECTED TO
THE UPPER TEENS AND LOWER FOR THE NORTHERN 1/2 OF THE CWA AND
MID/UPPER 20S CENTRAL TO THE DOWNEAST REGION.
THINGS GET EVEN MORE INTERESTING THIS EVENING AND OVERNIGHT W/THE
ARCTIC FRONT EXPECTED TO MOVE ACROSS THE REGION. BOTH THE NAM AND
GFS SOUNDINGS SHOW DEEP MOISTURE THROUGH 700MBS W/ANOTHER ROUND OF
STEEP LAPSE RATES AOA 7.0C/KM IN THE 850-700MB LAYER. DECENT SHEAR
OF 30KTS IN THE 0-3KM LAYER. BTV SNOW SQUALL PARAMETER SHOWS A
STRONG SIGNAL SUPPORTING THE POTENTIAL FOR SNOW SQUALLS WHICH
COULD DUMP A QUICK INCH OF SNOW W/GUSTY WINDS AND VSBYS BLO 1/2SM.
STAYED W/THE DAYCREW`S ASSESSMENT OF 60% POPS ACROSS THE NORTHERN
1/2 OF THE CWA INTO TONIGHT AS THE ARCTIC FRONT SLIDES ACROSS THE
REGION. TEMPERATURES WILL DROP OFF, BUT NOT UNTIL AFTER 09Z.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
THE COLD FRONT WILL SWEEP EAST ON FRIDAY AS HIGH PRESSURE BEGINS TO
BUILD IN FROM CENTRAL CANADA. WE COULD SEE A FEW MORNING SNOW
SHOWERS OTHERWISE PARTLY TO MOSTLY CLOUDY SKIES CAN BE EXPECTED
ACROSS THE REGION ON FRIDAY. HIGHS ON FRIDAY WILL RANGE FROM 10 TO
15 ABOVE NORTH AND MID 20S DOWN EAST.
MAINLY CLEAR AND VERY COLD WEATHER CAN BE EXPECTED FOR FRIDAY NIGHT. LOWS
WILL RANGE FROM 10 TO 15 BELOW ACROSS TEH NORTH AND ZERO TO 10
ABOVE DOWNEAST.
MOSTLY SUNNY SKIES CAN BE EXPECTED ON SATURDAY BEFORE WE SEE
INCREASING HIGH CLOUDS SATURADY AFTERNOON. HIGHS ON SATURDAY WILL
RANGE FROM THE SINGLE DIGITS ABOVE ZERO NORTH AND MID TEENS TO
NEAR 20S DOWN EAST.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
CLOUDS INCREASE SATURDAY EVENING WITH SNOW DEVELOPING AFTER
MIDNIGHT. THE LATEST GFS/ECMWF TRACK LOW PRESSURE OFF TO OUR
NORTHWEST DURING SATURDAY NIGHT AND SUNDAY AS WEAK LOW PRESSURE
DEVELOPS ALONG THE DOWN EAST COAST. APPEARS AS IF THE LOW TRACKING
OFF TO OUR NORTHWEST WILL REMAIN THE PRIMARY LOW ALLOWING WARMER
AIR TO CHANGE PRECIPITATION TO A MIX OR ALL RAIN ACROSS DOWNEAST
AND CENTRAL AREAS DURING SUNDAY. AT THIS TIME LOOKS LIKE THIS
SYSTEM WILL BE AN ADVISORY LEVEL EVENT. PRECIPITATION WILL START
TO WIND DOWN SUNDAY NIGHT AS THE LOW MOVES AWAY FROM THE REGION.
VERY COLD AIR WILL BEGIN TO POUR INTO THE REGION DURING MONDAY
WITH HIGHS OCCURRING EARLY IN THE DAY. VERY COLD AND DRY WEATHER
FOR MONDAY NIGHT AND TUEDSAY. A CLIPPER TYPE LOW MAY BRING SOME
SNOW TO ESPECIALLY DOWN EAST AREAS TUESDAY NIGHT AND WEDNESDAY.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
NEAR TERM: VFR EXPECTED W/TEH EXCEPTION OF THE NORTHERN TERMINALS
ESPECIALLY KCAR AND KFVE AS MVFR CONDITIONS ARE POSSIBLE LATER
THIS AFTERNOON INTO TONIGHT IN SNOW SHOWERS/SQUALLS.
SHORT TERM: IFR IN PRECIPITATION SATURDAY NIGHT THROUGH SUNDAY
NIGHT. OTHERWISE VFR FRIDAY AND MONDAY.
&&
.MARINE...
NEAR TERM: THE SCA WILL STAY UP THROUGH TONIGHT W/WINDS INCREASING
TO 20-25 KTS BY TONIGHT. THE OUTER ZONES COULD SEE GUSTS TO 30 KTS
AS A LLVL JET OF 45 KTS MOVES OVER THE WATERS AHEAD OF THE APCHG
ARCTIC FRONT. SEAS WILL RESPOND ACCORDINGLY BUILDING TO 6-8 FT BY
TONIGHT.
SHORT TERM:SMALL CRAFT ADVISORY LEVEL CONDITIONS ARE EXPECTED
FRIDAY AND FRIDAY NIGHT. CONDITIONS SHOULD THEN DECREASE BELOW
SMALL CRAFT ADVISORY LEVELS SATURDAY WITH CONDITIONS ONCE AGAIN
INCREASING TO SCA LEVELS SATURDAY NIGHT AND SUNDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EST FRIDAY FOR ANZ050>052.
&&
$$
NEAR TERM...HEWITT
SHORT TERM...DUDA
LONG TERM...DUDA
AVIATION...HEWITT/DUDA
MARINE...HEWITT/DUDA
AREA FORECAST DISCUSSION
NWS CARIBOU ME
518 AM EST THU JAN 1 2015
.SYNOPSIS...
A WARM FRONT WILL LIFT ACROSS THE REGION TODAY. AN ARCTIC FRONT
WILL SWEEP THROUGH THE REGION LATER TONIGHT INTO FRIDAY. HIGH
PRESSURE WILL BUILD INTO THE REGION FROM CANADA FRIDAY NIGHT INTO
SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
LATEST SURFACE ANALYSIS SHOWED WARM FRONT LIFTING N ACROSS THE
PINE TREE STATE. SOME LIGHT PRECIP IN THE FORM OF SOME LIGHT SNOW
ACROSS THE IMMEDIATE COAST W/MOST OF PRECIP OFFSHORE. FURTHER N,
THE RADAR SHOWED SOME VERY LIGHT RETURNS IN THE FORM OF SOME
FLURRIES. TEMPERATURES WERE SLOWLY RISING THIS MORNING AND WILL
CONTINUE TO DO SO TODAY W/THE WARM FRONT PASSAGE. PERIODS OF LIGHT
SNOW/SNOW SHOWERS EXPECTED ACROSS THE NORTH AND WEST AND RIGHT
ALONG THE DOWNEAST COAST. THE NAM AND RAP GUIDANCE POINT TO SOME
STEEPENING LAPSE RATES OF 7.0C/KM FROM 850-700MBS W/THE WARM
FRONT. THE BEST CHANCE FOR ANY ACCUMULATING SNOW WILL BE ACROSS
THE FAR W AND NW W/AN INCH POSSIBLE. TEMPERATURES ARE EXPECTED TO
THE UPPER TEENS AND LOWER FOR THE NORTHERN 1/2 OF THE CWA AND
MID/UPPER 20S CENTRAL TO THE DOWNEAST REGION.
THINGS GET EVEN MORE INTERESTING THIS EVENING AND OVERNIGHT W/THE
ARCTIC FRONT EXPECTED TO MOVE ACROSS THE REGION. BOTH THE NAM AND
GFS SOUNDINGS SHOW DEEP MOISTURE THROUGH 700MBS W/ANOTHER ROUND OF
STEEP LAPSE RATES AOA 7.0C/KM IN THE 850-700MB LAYER. DECENT SHEAR
OF 30KTS IN THE 0-3KM LAYER. BTV SNOW SQUALL PARAMETER SHOWS A
STRONG SIGNAL SUPPORTING THE POTENTIAL FOR SNOW SQUALLS WHICH
COULD DUMP A QUICK INCH OF SNOW W/GUSTY WINDS AND VSBYS BLO 1/2SM.
STAYED W/THE DAYCREW`S ASSESSMENT OF 60% POPS ACROSS THE NORTHERN
1/2 OF THE CWA INTO TONIGHT AS THE ARCTIC FRONT SLIDES ACROSS THE
REGION. TEMPERATURES WILL DROP OFF, BUT NOT UNTIL AFTER 09Z.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
THE COLD FRONT WILL SWEEP EAST ON FRIDAY AS HIGH PRESSURE BEGINS TO
BUILD IN FROM CENTRAL CANADA. WE COULD SEE A FEW MORNING SNOW
SHOWERS OTHERWISE PARTLY TO MOSTLY CLOUDY SKIES CAN BE EXPECTED
ACROSS THE REGION ON FRIDAY. HIGHS ON FRIDAY WILL RANGE FROM 10 TO
15 ABOVE NORTH AND MID 20S DOWN EAST.
MAINLY CLEAR AND VERY COLD WEATHER CAN BE EXPECTED FOR FRIDAY NIGHT. LOWS
WILL RANGE FROM 10 TO 15 BELOW ACROSS TEH NORTH AND ZERO TO 10
ABOVE DOWNEAST.
MOSTLY SUNNY SKIES CAN BE EXPECTED ON SATURDAY BEFORE WE SEE
INCREASING HIGH CLOUDS SATURADY AFTERNOON. HIGHS ON SATURDAY WILL
RANGE FROM THE SINGLE DIGITS ABOVE ZERO NORTH AND MID TEENS TO
NEAR 20S DOWN EAST.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
CLOUDS INCREASE SATURDAY EVENING WITH SNOW DEVELOPING AFTER
MIDNIGHT. THE LATEST GFS/ECMWF TRACK LOW PRESSURE OFF TO OUR
NORTHWEST DURING SATURDAY NIGHT AND SUNDAY AS WEAK LOW PRESSURE
DEVELOPS ALONG THE DOWN EAST COAST. APPEARS AS IF THE LOW TRACKING
OFF TO OUR NORTHWEST WILL REMAIN THE PRIMARY LOW ALLOWING WARMER
AIR TO CHANGE PRECIPITATION TO A MIX OR ALL RAIN ACROSS DOWNEAST
AND CENTRAL AREAS DURING SUNDAY. AT THIS TIME LOOKS LIKE THIS
SYSTEM WILL BE AN ADVISORY LEVEL EVENT. PRECIPITATION WILL START
TO WIND DOWN SUNDAY NIGHT AS THE LOW MOVES AWAY FROM THE REGION.
VERY COLD AIR WILL BEGIN TO POUR INTO THE REGION DURING MONDAY
WITH HIGHS OCCURRING EARLY IN THE DAY. VERY COLD AND DRY WEATHER
FOR MONDAY NIGHT AND TUEDSAY. A CLIPPER TYPE LOW MAY BRING SOME
SNOW TO ESPECIALLY DOWN EAST AREAS TUESDAY NIGHT AND WEDNESDAY.
&&
.AVIATION /09Z THURSDAY THROUGH MONDAY/...
NEAR TERM: VFR EXPECTED W/TEH EXCEPTION OF THE NORTHERN TERMINALS
ESPECIALLY KCAR AND KFVE AS MVFR CONDITIONS ARE POSSIBLE LATER
THIS AFTERNOON INTO TONIGHT IN SNOW SHOWERS/SQUALLS.
SHORT TERM: IFR IN PRECIPITATION SATURDAY NIGHT THROUGH SUNDAY
NIGHT. OTHERWISE VFR FRIDAY AND MONDAY.
&&
.MARINE...
NEAR TERM: THE SCA WILL STAY UP THROUGH TONIGHT W/WINDS INCREASING
TO 20-25 KTS BY TONIGHT. THE OUTER ZONES COULD SEE GUSTS TO 30 KTS
AS A LLVL JET OF 45 KTS MOVES OVER THE WATERS AHEAD OF THE APCHG
ARCTIC FRONT. SEAS WILL RESPOND ACCORDINGLY BUILDING TO 6-8 FT BY
TONIGHT.
SHORT TERM:SMALL CRAFT ADVISORY LEVEL CONDITIONS ARE EXPECTED
FRIDAY AND FRIDAY NIGHT. CONDITIONS SHOULD THEN DECREASE BELOW
SMALL CRAFT ADVISORY LEVELS SATURDAY WITH CONDITIONS ONCE AGAIN
INCREASING TO SCA LEVELS SATURDAY NIGHT AND SUNDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EST FRIDAY FOR ANZ050>052.
&&
$$
NEAR TERM...HEWITT
SHORT TERM...DUDA
LONG TERM...DUDA
AVIATION...HEWITT/DUDA
MARINE...HEWITT/DUDA
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
931 AM CST THU JAN 1 2015
.UPDATE...
SUBSTANTIAL ADJUSTMENTS NEEDED TO FORECAST TODAY...PRIMARILY TO
INCREASE POPS ESPECIALLY OVER S/SW SECTIONS...AND TO LOWER TEMPS A
BIT.
&&
.SHORT TERM...
MORNING RADAR AND ANALYSES SHOW EXPANDING AREA OF PRECIPITATION
ACROSS MUCH OF LA/E TX/S AR/SW MS. THIS IS IN AREA OF INCREASING
MOISTURE ADVECTION/ISENTROPIC ASCENT ABOVE REMNANT WEAKENING SFC HIGH
PRESSURE ACROSS REGION. RADAR TRENDS AND LATEST HRRR/RAP MODELS
SUGGEST THAT EARLIER GLOBAL MODELS WERE A BIT TOO FAR NORTH IN
DEPICTION OF BEST RAINFALL POTENTIAL FOR TODAY...WITH BETTER MOISTURE
ADVECTION LIKELY TO FOCUS BETTER QPF FARTHER TO THE S CLOSER TO THE
I-20 CORRIDOR. BLEND OF LAST FEW HRRR RUNS SUGGEST AN AXIS OF 0.5 TO
1.5" OF QPF THROUGH EARLY THIS EVENING FROM THE LOWER ARKLAMISS DELTA
BACK WSW INTO EC TX...WITH AMOUNTS OF AT LEAST .1" OVER MOST OF OUR
SERVICE AREA. HENCE HAVE ADJUSTED POPS TO MAINTAIN HIGH POPS OVER
DELTA BUT EXPAND CATEGORICAL POPS TO ENCOMPASS MOST OF THE WESTERN
2/3 OF OUR AREA. TAPERED POPS TO THE E WHERE BETTER MOISTURE
ADVECTION WILL BE SLOWER TO ARRIVE AND HENCE BETTER CHANCES FOR RAIN.
HAVE HAD A COUPLE OF REPORTS OF SLEET IN WESTERN AREAS THIS
MORNING...AND COLD...DRY SUBCLOUD LAYER DEPICTED IN SOUNDINGS THIS
MORNING SUGGEST THIS REMAINS A POSSIBILITY NEXT FEW HOURS ESPECIALLY
NORTHERN HALF OF AREA. HAVE KEPT THIS IN GRIDS...BUT AS MENTIONED IN
PREVIOUS AFD SHOULD NOT BE ANY IMPACT WITH TEMPS ABOVE FREEZING.
LIGHTNING DATA HAS SHOWN SPORADIC STRIKES WITH ACTIVITY SHIFTING
ACROSS E TX THIS MORNING...AND MODELS SHOW A COUPLE OF HUNDRED OF
JOULES OF ELEVATED CAPE WORKING INTO SW SECTIONS OF OUR AREA THIS
AFTERNOON. THIS IN COMBO WITH HRRR HAVING SOME CONVECTIVE LOOKING
ELEMENTS IN ITS REFLECTIVITY FORECASTS HAVE RESULTED IN AN ADDITION
OF SLGT CHC TSRA FOR SW AREAS THIS AFTERNOON WHICH ALSO AGREES WITH
LATEST SPC DAY 1 OUTLOOK.
GIVEN ARRIVAL OF CLOUDS/RAIN AND CONTINUED STAGNANT REMNANT
COLD...DRY SURFACE HIGH OVER AREA...THINK TEMPS WILL REALLY
STRUGGLE MOST AREAS TODAY. HENCE HAVE KNOCKED A COUPLE OF DEGS OFF
MAXES AND WENT WITH HRRR HOURLY TEMPS. A BIT OF MORNING SUN IN FAR
E/SE SECTIONS COULD ALLOW TEMPS THERE TO REACH FORECAST MAXES AND
HRRR SUPPORTS THIS AS WELL...SO PRETTY MUCH LEFT MAXES IN THOSE AREAS
ALONE. /AEG/
&&
.AVIATION...
CIGS CONTINUE TO BE MAINLY VFR EVEN WITH LIGHT PRECIPITATION
SPREADING EASTWARD ACROSS THE MS RIVER...INCLUDING SOME
INSIGNIFICANT AMOUNTS OF LIGHT SLEET AT THE ONSET. BUT CONDITIONS
QUICKLY WORSEN JUST WEST OF THE FORECAST AREA WITH WIDESPREAD
MVFR/IFR CIGS AND VSBYS ASSOCIATED WITH RA/TSRA OVER WRN LA. EXPECT
THIS HEAVIER RAINFALL TO CONTINUE TO DEVELOP EAST AND AFFECT THE
GLH/GWO/JAN/HKS AREA INITIALLY THIS AFTERNOON...THEN ALL TAF SITES
AS WE GO THROUGH TONIGHT. SOME ISOLATED TSRA WILL BE POSSIBLE
PARTICULARLY AT GLH/JAN/HKS/HBG. FRIDAY WILL BE A POOR AVIATION
WEATHER DAY WITH WIDESPREAD RA/TSRA PRODUCING IFR CONDITIONS OVER
THE ENTIRE AREA. /EC/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 46 43 52 52 / 91 86 85 67
MERIDIAN 54 44 52 52 / 63 75 86 66
VICKSBURG 44 41 50 50 / 96 91 87 75
HATTIESBURG 56 48 60 60 / 58 64 71 50
NATCHEZ 44 43 56 55 / 92 86 75 71
GREENVILLE 45 38 45 44 / 95 95 93 82
GREENWOOD 47 39 47 47 / 90 91 91 74
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
AEG/EC
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
504 AM CST THU JAN 1 2015
.DISCUSSION...
HAPPY NEW YEAR FROM ALL OF US AT NWS JACKSON!
SHORT TERM (TODAY THROUGH FRIDAY NIGHT)...
WHILE COOL/RELATIVELY DRY NORTHERLY/EASTERLY FLOW WILL CONTINUE AT
THE SURFACE...BIG CHANGES ARE AFOOT ABOUT 2000 FEET UP. FLOW IN THE
LOWER LEVELS OF THE ATMOSPHERE WILL SHIFT AROUND TO THE SOUTHWEST...
WITH STRONG ISENTROPIC UPGLIDE COMMENCING OVER THE REGION BRINGING
INCREASING PRECIP CHANCES BY THIS AFTERNOON. LOOKING EVEN HIGHER IN
THE ATMOSPHERE...AN UPPER LOW WAS LOCATED NEAR THE FOUR CORNERS
REGION WITH A SPLIT UPPER JET OVER THE WEST PHASING TOGETHER OVER
THE MIDWEST/MID ATLANTIC. MID AND HIGH CLOUDS HAVE ALREADY BEEN ON
THE INCREASE ACROSS MUCH OF THE REGION OVERNIGHT...WHICH HAS LIMITED
RADIATIONAL COOLING IN MANY AREAS. AS MORE SUBSTANTIAL ATMOSPHERIC
MOISTENING OCCURS THROUGH THE DAY...THE CLOUD DECK WILL GRADUALLY
LOWER AND LIGHT PRECIP WILL BEGIN TO REACH THE SURFACE.
REGIONAL RADAR SHOWED LIGHT PRECIP REACHING THE ARKLATEX INTO NW
LOUISIANA. LATEST HRRR RUNS SUGGEST SOME OF THIS ACTIVITY WILL MOVE
INTO OUR NE LOUISIANA PARISHES SHORTLY AFTER DAYBREAK... SLOWLY
SPREADING EASTWARD THROUGH THE MORNING. DUE TO SUBSTANTIALLY DRY AIR
BELOW AROUND 800 MB...IT MAY TAKE A WHILE FOR PRECIP TO REACH THE
GROUND...SO WE MAY SEE SEVERAL ECHOES ON RADAR WITH ONLY SPRINKLES
INITIALLY. THIS DRY AIR MAY ALSO LEAD TO SOME LIGHT SLEET AT THE
ONSET OF PRECIPITATION OVER THE DELTA AS WETBULBING OCCURS IN THE DRY
LAYER. BUFR SOUNDINGS SUGGEST THIS WILL BE POSSIBLE UNTIL AROUND OR
SHORTLY AFTER NOON. MAINTAINED A MENTION OF SLIGHT CHANCE OF SLEET IN
THE FORECAST...BUT TO BE CLEAR...NO MEASURABLE SLEET AND NO IMPACTS
ARE EXPECTED AS SURFACE TEMPS WILL BE ABOVE FREEZING DURING THIS TIME
PERIOD AND PRECIP WILL BE RATHER LIGHT.
MORE SUBSTANTIAL RAIN CHANCES WILL COME OVER THE NORTHWEST HALF OF
THE CWA THIS AFTERNOON INTO TONIGHT ONCE LOW LEVEL DRY AIR IS NO
LONGER AN ISSUE. THE CLOSED UPPER LOW WILL BECOME EMBEDDED IN UPPER
LEVEL FLOW AS A TROUGH MOVING INTO THE SOUTHERN PLAINS ON FRIDAY.
THIS WILL BRING MORE FAVORABLE UPPER DIVERGENCE OVER THE AREA...
ESPECIALLY FARTHER NORTH IN THE CWA CLOSER TO THE UPPER JET
STREAK...WITH CONTINUED ISENTROPIC ASCENT IN THE LOWER LEVELS. THUS
LIKELY TO CATEGORICAL POPS WILL BE MAINTAINED ACROSS MOST OF THE CWA
THROUGH FRIDAY NIGHT. THOUGH THE ATMOSPHERE WILL REMAIN STABLE AT THE
SURFACE THROUGH MUCH OF THIS TIME...THERE WILL BE ELEVATED
INSTABILITY AND CHANCE/SLIGHT CHANCE THUNDERSTORMS WERE MAINTAINED IN
THE FORECAST.
THE EASTWARD ADVANCE OF THE UPPER TROUGH WILL ALSO PROMPT SURFACE
CYCLOGENESIS ALONG THE NW GULF COAST. THIS LOW WILL TRACK NORTHWARD
FRIDAY NIGHT...FINALLY BRINGING RETURN FLOW AT THE SURFACE OVERNIGHT.
SOME SURFACE BASED CONVECTION WILL BE POSSIBLE ACROSS THE SOUTH PART
OF THE AREA OVERNIGHT AS DEWPOINTS RISE INTO THE MID 60S WITH SBCAPES
POTENTIALLY RISING INTO THE 500-1000 J/KG RANGE. TEMPERATURES THROUGH
THE SHORT TERM WILL PRIMARILY BE DRIVEN BY THE PRESENCE OF CLOUDS AND
PRECIP...AND WAA ON FRIDAY NIGHT. TRENDED CLOSE TO RAW TEMP GUIDANCE
THROUGHOUT THE PERIOD. /DL/
LONG TERM (SATURDAY THROUGH THURSDAY)L...ACTIVE WEATHER WILL CONTINUE
INTO THE EXTENDED...WHERE THE PRIMARY FOCUS WILL BE ON HEAVY RAIN AND
STORM POTENTIAL.
ON SATURDAY A MID TO UPPER LEVEL CLOSED LOW WILL BE MOVING THROUGH
THE PLAINS AND WILL EJECT AS A NEGATIVE TILTED SHORTWAVE TOWARD THE
THE OHIO VALLEY. WE WILL BE UNDER THE RIGHT REAR QUAD OF AN MID TO
UPPER LEVEL JET. ALSO LOWLEVEL JET WINDS(850-925 MB) WILL BE AROUND
35 TO 55 KNOTS...FROM THE SOUTH. THIS WILL SPELL GUSTY SOUTH WINDS
ACROSS THE REGION WITH GUSTS 25-28 KNOTS. MEANWHILE LARGE SCALE
MOISTURE TRANSPORT AND ASCENT WILL BE IN PROGRESS AS THE WARM SECTOR
SURGES 60S DEWPOINTS INTO MOST OF THE REGION. THE QUESTION IS HOW FAR
NORTH WILL WARM MARINE LAYER (MID TO UPPER 60S DEWPOINTS) TRAVEL. A
COLD FRONT WILL MOVE ACROSS THE REGION DURING THE DAY WITH A SURFACE
LOW MOVING NORTHEAST AND DEEPENING. CHECKING 00Z AND 12Z MODEL RUNS
WHICH WERE SIMILAR WITH THE TRACK OF THE SURFACE LOW GENERALLY WEST
OF THE MS RIVER...THUS BRINGING BETTER LOW LEVEL INSTABILITY ACROSS
MOST THE REGION. MODEL SOUNDINGS SHOW GOOD SHEAR ALONG WITH CURVED
HODOGRAPHS FOR SOME SEVERE POTENTIAL. THE GFS TRIES TO BRING IN 65
PLUS DEWPOINTS NEAR THE I-20 CORRIDOR WITH NEAR 70 DEWPOINTS NEAR OUR
SOUTHEAST BORDER. THIS WILL BRING SOME CAPES IN EXCESS OF 1500 J/KG.
THE SHEAR VECTORS WILL BE GENERALLY PARALLEL TO THE FRONT FOR SOME
POSSIBLE QLCS COMPLEXES ALONG WITH HELICITY > 300. HEIGHTS ACROSS THE
SOUTHEAST THOUGH ARE A LITTLE HIGH FOR THIS TIME OF THE YEAR. SPC
SREF...CIPS AND NAM MODELS POINT THE GREATEST SEVERE RISK ALONG THE
NATCHEZ TRACE CORRIDOR...WHERE THE HEIGHTS ARE A LITTLE MORE
CONDUCIVE. IF THIS TREND CONTINUES MAY CONSIDER PUTTING THAT AREA IN
AN ELEVATED RISK IN FUTURE MODEL RUNS. SO WILL KEEP THE LIMITED RISK
FOR NOW. THE COLD FRONT WILL EXIT THE REGION DURING THE EVENING THUS
ENDING THE SEVERE RISK.
LOOKING AT THE HEAVY RAIN RISK. PWATS WILL INCREASE TO AROUND 1.7
INCHES WHICH IS THE HIGHER AVERAGE PERCENTILE FOR THIS TIME OF
YEAR...WHICH SPELLS EFFICIENT RAINS. MODELS AND HPC ARE GENERALLY
GOING FOR 1-2 INCHES WITH LOCALLY INCH AMOUNTS POSSIBLE ALONG AND
AHEAD OF THE COLD FRONT. THIS WILL ADD TO OUR RECENT RAINS FOR
SATURATED SOIL CONDITIONS. SO WILL KEEP THE LIMITED RISK FOR
FLOODING FOR FRIDAY INTO SATURDAY. UNLESS THE MODELS SIGNAL
HIGHER RAINFALL AMOUNTS IN FUTURE MODEL RUNS...NO FLOOD WATCH WILL
BE CONSIDERED AT THIS TIME.
THE RAINS WILL EXIT THE REGION ON SUNDAY MORNING. HIGH PRESSURE WILL
SETTLE ACROSS THE REGION ON MONDAY. SO DRY AND COOL CONDITIONS WILL
PREVAIL FOR SUNDAY THROUGH WEDNESDAY. ANOTHER SURGE OF COOL AIR WILL
PUSH INTO THE REGION FOR TUESDAY INTO WEDNESDAY. WITH THIS AIRMASS
IT LOOKS LIKE THE BEST PART OF THIS AIRMASS WILL MISS THE REGION
TO THE NORTH. ON THURSDAY SHORTWAVE RIDGING WILL BUILD IN FROM THE
WEST AS LOW LEVEL RETURN FLOW COMES IN FOR SOME SHOWERS IN THE
SOUTHWEST BY EARLY FRIDAY./17/
&&
.AVIATION...VFR CONDITIONS WILL CONTINUE THROUGH AT LEAST EARLY
AFTERNOON AT MOST TERMINALS...BUT THE MID CLOUD DECK WILL GRADUALLY
LOWER THROUGH THE DAY...LIKELY REACHING MVFR CATEGORY TONIGHT IN ALL
AREAS EXCEPT AROUND MEI AND HBG. LIGHT RAIN WILL SPREAD EASTWARD INTO
THE REGION THIS MORNING...BECOMING MODERATE LATER ON TONIGHT. THIS
MAY BRING VISIBILITY REDUCTIONS TO MVFR ESPECIALLY AT NORTHWEST
TERMINALS WHERE MORE SUBSTANTIAL RAINFALL IS EXPECTED THROUGH THE TAF
PERIOD. CEILING AND OCCASIONAL VISIBILITY REDUCTIONS WILL LIKELY
PERSIST THROUGH THE WEEKEND. THERE IS A SMALL CHANCE OF LIGHT SLEET
AT GWO AND GLH THIS MORNING...BUT NO ISSUES ARE EXPECTED TO RESULT
FROM THIS. /DL/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 47 43 52 52 / 34 86 85 67
MERIDIAN 52 44 52 52 / 17 75 86 66
VICKSBURG 43 41 50 50 / 61 91 87 75
HATTIESBURG 57 48 60 60 / 21 64 71 50
NATCHEZ 45 43 56 55 / 42 86 75 71
GREENVILLE 40 38 45 44 / 93 95 93 82
GREENWOOD 44 39 47 47 / 91 91 91 74
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
DL/17
AREA FORECAST DISCUSSION
NWS JACKSON MS
418 AM CST THU JAN 1 2015
.DISCUSSION...
HAPPY NEW YEAR FROM ALL OF US AT NWS JACKSON!
SHORT TERM (TODAY THROUGH FRIDAY NIGHT)...
WHILE COOL/RELATIVELY DRY NORTHERLY/EASTERLY FLOW WILL CONTINUE AT
THE SURFACE...BIG CHANGES ARE AFOOT ABOUT 2000 FEET UP. FLOW IN THE
LOWER LEVELS OF THE ATMOSPHERE WILL SHIFT AROUND TO THE SOUTHWEST...
WITH STRONG ISENTROPIC UPGLIDE COMMENCING OVER THE REGION BRINGING
INCREASING PRECIP CHANCES BY THIS AFTERNOON. LOOKING EVEN HIGHER IN
THE ATMOSPHERE...AN UPPER LOW WAS LOCATED NEAR THE FOUR CORNERS
REGION WITH A SPLIT UPPER JET OVER THE WEST PHASING TOGETHER OVER
THE MIDWEST/MID ATLANTIC. MID AND HIGH CLOUDS HAVE ALREADY BEEN ON
THE INCREASE ACROSS MUCH OF THE REGION OVERNIGHT...WHICH HAS LIMITED
RADIATIONAL COOLING IN MANY AREAS. AS MORE SUBSTANTIAL ATMOSPHERIC
MOISTENING OCCURS THROUGH THE DAY...THE CLOUD DECK WILL GRADUALLY
LOWER AND LIGHT PRECIP WILL BEGIN TO REACH THE SURFACE.
REGIONAL RADAR SHOWED LIGHT PRECIP REACHING THE ARKLATEX INTO NW
LOUISIANA. LATEST HRRR RUNS SUGGEST SOME OF THIS ACTIVITY WILL MOVE
INTO OUR NE LOUISIANA PARISHES SHORTLY AFTER DAYBREAK... SLOWLY
SPREADING EASTWARD THROUGH THE MORNING. DUE TO SUBSTANTIALLY DRY AIR
BELOW AROUND 800 MB...IT MAY TAKE A WHILE FOR PRECIP TO REACH THE
GROUND...SO WE MAY SEE SEVERAL ECHOES ON RADAR WITH ONLY SPRINKLES
INITIALLY. THIS DRY AIR MAY ALSO LEAD TO SOME LIGHT SLEET AT THE
ONSET OF PRECIPITATION OVER THE DELTA AS WETBULBING OCCURS IN THE DRY
LAYER. BUFR SOUNDINGS SUGGEST THIS WILL BE POSSIBLE UNTIL AROUND OR
SHORTLY AFTER NOON. MAINTAINED A MENTION OF SLIGHT CHANCE OF SLEET IN
THE FORECAST...BUT TO BE CLEAR...NO MEASURABLE SLEET AND NO IMPACTS
ARE EXPECTED AS SURFACE TEMPS WILL BE ABOVE FREEZING DURING THIS TIME
PERIOD AND PRECIP WILL BE RATHER LIGHT.
MORE SUBSTANTIAL RAIN CHANCES WILL COME OVER THE NORTHWEST HALF OF
THE CWA THIS AFTERNOON INTO TONIGHT ONCE LOW LEVEL DRY AIR IS NO
LONGER AN ISSUE. THE CLOSED UPPER LOW WILL BECOME EMBEDDED IN UPPER
LEVEL FLOW AS A TROUGH MOVING INTO THE SOUTHERN PLAINS ON FRIDAY.
THIS WILL BRING MORE FAVORABLE UPPER DIVERGENCE OVER THE AREA...
ESPECIALLY FARTHER NORTH IN THE CWA CLOSER TO THE UPPER JET
STREAK...WITH CONTINUED ISENTROPIC ASCENT IN THE LOWER LEVELS. THUS
LIKELY TO CATEGORICAL POPS WILL BE MAINTAINED ACROSS MOST OF THE CWA
THROUGH FRIDAY NIGHT. THOUGH THE ATMOSPHERE WILL REMAIN STABLE AT THE
SURFACE THROUGH MUCH OF THIS TIME...THERE WILL BE ELEVATED
INSTABILITY AND CHANCE/SLIGHT CHANCE THUNDERSTORMS WERE MAINTAINED IN
THE FORECAST.
THE EASTWARD ADVANCE OF THE UPPER TROUGH WILL ALSO PROMPT SURFACE
CYCLOGENESIS ALONG THE NW GULF COAST. THIS LOW WILL TRACK NORTHWARD
FRIDAY NIGHT...FINALLY BRINGING RETURN FLOW AT THE SURFACE OVERNIGHT.
SOME SURFACE BASED CONVECTION WILL BE POSSIBLE ACROSS THE SOUTH PART
OF THE AREA OVERNIGHT AS DEWPOINTS RISE INTO THE MID 60S WITH SBCAPES
POTENTIALLY RISING INTO THE 500-1000 J/KG RANGE. TEMPERATURES THROUGH
THE SHORT TERM WILL PRIMARILY BE DRIVEN BY THE PRESENCE OF CLOUDS AND
PRECIP...AND WAA ON FRIDAY NIGHT. TRENDED CLOSE TO RAW TEMP GUIDANCE
THROUGHOUT THE PERIOD. /DL/
LONG TERM (SATURDAY THROUGH THURSDAY)L...ACTIVE WEATHER WILL CONTINUE
INTO THE EXTENDED...WHERE THE PRIMARY FOCUS WILL BE ON HEAVY RAIN AND
STORM POTENTIAL.
ON SATURDAY A MID TO UPPER LEVEL CLOSED LOW WILL BE MOVING THROUGH
THE PLAINS AND WILL EJECT AS A NEGATIVE TILTED SHORTWAVE TOWARD THE
THE OHIO VALLEY. WE WILL BE UNDER THE RIGHT REAR QUAD OF AN MID TO
UPPER LEVEL JET. ALSO LOWLEVEL JET WINDS(850-925 MB) WILL BE AROUND
35 TO 55 KNOTS...FROM THE SOUTH. THIS WILL SPELL GUSTY SOUTH WINDS
ACROSS THE REGION WITH GUSTS 25-28 KNOTS. MEANWHILE LARGE SCALE
MOISTURE TRANSPORT AND ASCENT WILL BE IN PROGRESS AS THE WARM SECTOR
SURGES 60S DEWPOINTS INTO MOST OF THE REGION. THE QUESTION IS HOW FAR
NORTH WILL WARM MARINE LAYER (MID TO UPPER 60S DEWPOINTS) TRAVEL. A
COLD FRONT WILL MOVE ACROSS THE REGION DURING THE DAY WITH A SURFACE
LOW MOVING NORTHEAST AND DEEPENING. CHECKING 00Z AND 12Z MODEL RUNS
WHICH WERE SIMILAR WITH THE TRACK OF THE SURFACE LOW GENERALLY WEST
OF THE MS RIVER...THUS BRINGING BETTER LOW LEVEL INSTABILITY ACROSS
MOST THE REGION. MODEL SOUNDINGS SHOW GOOD SHEAR ALONG WITH CURVED
HODOGRAPHS FOR SOME SEVERE POTENTIAL. THE GFS TRIES TO BRING IN 65
PLUS DEWPOINTS NEAR THE I-20 CORRIDOR WITH NEAR 70 DEWPOINTS NEAR OUR
SOUTHEAST BORDER. THIS WILL BRING SOME CAPES IN EXCESS OF 1500 J/KG.
THE SHEAR VECTORS WILL BE GENERALLY PARALLEL TO THE FRONT FOR SOME
POSSIBLE QLCS COMPLEXES ALONG WITH HELICITY > 300. HEIGHTS ACROSS THE
SOUTHEAST THOUGH ARE A LITTLE HIGH FOR THIS TIME OF THE YEAR. SPC
SREF...CIPS AND NAM MODELS POINT THE GREATEST SEVERE RISK ALONG THE
NATCHEZ TRACE CORRIDOR...WHERE THE HEIGHTS ARE A LITTLE MORE
CONDUCIVE. IF THIS TREND CONTINUES MAY CONSIDER PUTTING THAT AREA IN
AN ELEVATED RISK IN FUTURE MODEL RUNS. SO WILL KEEP THE LIMITED RISK
FOR NOW. THE COLD FRONT WILL EXIT THE REGION DURING THE EVENING THUS
ENDING THE SEVERE RISK.
LOOKING AT THE HEAVY RAIN RISK. PWATS WILL INCREASE TO AROUND 1.7
INCHES WHICH IS THE HIGHER AVERAGE PERCENTILE FOR THIS TIME OF
YEAR...WHICH SPELLS EFFICIENT RAINS. MODELS AND HPC ARE GENERALLY
GOING FOR 1-2 INCHES WITH LOCALLY INCH AMOUNTS POSSIBLE ALONG AND
AHEAD OF THE COLD FRONT. THIS WILL ADD TO OUR RECENT RAINS FOR
SATURATED SOIL CONDITIONS. SO WILL KEEP THE LIMITED RISK FOR
FLOODING FOR FRIDAY INTO SATURDAY. UNLESS THE MODELS SIGNAL
HIGHER RAINFALL AMOUNTS IN FUTURE MODEL RUNS...NO FLOOD WATCH WILL
BE CONSIDERED AT THIS TIME.
THE RAINS WILL EXIT THE REGION ON SUNDAY MORNING. HIGH PRESSURE WILL
SETTLE ACROSS THE REGION ON MONDAY. SO DRY AND COOL CONDITIONS WILL
PREVAIL FOR SUNDAY THROUGH WEDNESDAY. ANOTHER SURGE OF COOL AIR WILL
PUSH INTO THE REGION FOR TUESDAY INTO WEDNESDAY. WITH THIS AIRMASS
IT LOOKS LIKE THE BEST PART OF THIS AIRMASS WILL MISS THE REGION
TO THE NORTH. ON THURSDAY SHORTWAVE RIDGING WILL BUILD IN FROM THE
WEST AS LOW LEVEL RETURN FLOW COMES IN FOR SOME SHOWERS IN THE
SOUTHWEST BY EARLY FRIDAY./17/
&&
.AVIATION...VFR CONDITIONS WILL CONTINUE THROUGH AT LEAST EARLY
AFTERNOON AT MOST TERMINALS...BUT THE MID CLOUD DECK WILL GRADUALLY
LOWER THROUGH THE DAY...LIKELY REACHING MVFR CATEGORY TONIGHT IN ALL
AREAS EXCEPT AROUND MEI AND HBG. LIGHT RAIN WILL SPREAD EASTWARD INTO
THE REGION THIS MORNING...BECOMING MODERATE LATER ON TONIGHT. THIS
MAY BRING VISIBILITY REDUCTIONS TO MVFR ESPECIALLY AT NORTHWEST
TERMINALS WHERE MORE SUBSTANTIAL RAINFALL IS EXPECTED THROUGH THE TAF
PERIOD. CEILING AND OCCASIONAL VISIBILITY REDUCTIONS WILL LIKELY
PERSIST THROUGH THE WEEKEND. /DL/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 47 43 52 52 / 34 86 85 67
MERIDIAN 52 44 52 52 / 17 75 86 66
VICKSBURG 43 41 50 50 / 61 91 87 75
HATTIESBURG 57 48 60 60 / 21 64 71 50
NATCHEZ 45 43 56 55 / 42 86 75 71
GREENVILLE 40 38 45 44 / 93 95 93 82
GREENWOOD 44 39 47 47 / 91 91 91 74
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
DL/17
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
935 AM EST THU JAN 1 2015
.SYNOPSIS...
HIGH PRESSURE ACROSS THE SOUTHEASTERN U.S. WILL MOVE OFFSHORE
FRIDAY. RAIN CHANCES WILL INCREASE FRIDAY...WITH PERIODS OF RAIN
EXPECTED FRIDAY NIGHT AND SATURDAY AS A WARM FRONT APPROACHES. A
STRONG COLD FRONT MAY BRING A FEW THUNDERSTORMS SUNDAY AFTERNOON AND
NIGHT. CLEAR AND COLD CONDITIONS WILL OVERSPREAD THE CAROLINAS
MONDAY THROUGH WEDNESDAY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM THURSDAY...VERY FEW CHANGES WERE NEEDED TO THE
FORECAST. SKIES ARE CLEAR WITH SATELLITE IMAGERY INDICATING CIRRUS
NOW APPROACHING THE SOUTHERN APPALACHIANS WILL BEGIN TO REACH THE
COAST THIS AFTERNOON. 12Z SOUNDINGS FROM MHX AND GSO LOOKED MUCH
LIKE THE 06Z MODELS INDICATED. BASED ON RECENT HRRR AND RUC
MODELS I HAVE INCREASED ONSHORE WINDS BY A FEW MPH THIS AFTERNOON
NEAR THE BEACHES WITH A WEAK SEABREEZE CIRCULATION. THIS ONSHORE
WIND WILL ALSO UNFORTUNATELY DRAG SOME PRETTY CHILLY AIR BACK IN
FROM THE OCEAN DURING THE MID-AFTERNOON HOURS.
INLAND HIGHS SHOULD RANGE FROM 54-57...WITH THE BEACHES RUNNING A
FEW DEGREES COOLER.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...FOR THE MEDIUM AND LONG RANGE PACKAGE WILL
FAVOR THE GFS/ECMWF SOLUTION FOR THE PERIOD. H5 CUT OFF LOW ACROSS
THE SW RESULTS IN SPLIT FLOW ACROSS THE CONUS WITH RIDGING ACROSS
THE GULF COAST AND SE THROUGH THE PERIOD. EXPECT CLOUDS TO STREAM
INTO THE AREA AND THICKEN ON FRIDAY WITH PRECIPITATION CHANCES
INCREASING AS GULF MOISTURE BECOMES AVAILABLE. BELIEVE THE FIRST
HALF OF THE DAY SHOULD REMAIN DRY WITH CHANCE POPS DURING THE
LATER HALF OF FRIDAY. MAIN BULK OF PRECIPITATION STAYS TO OUR WEST
AS H5 LOW AND SURFACE LOW TRACK TO THE NE . H8 LOW LEVEL JET
INCREASE TO 30-35 KNOTS ACROSS THE REGION INCREASING LOW LEVEL
INSTABILITY AS EXIT REGION OF JET MOVES ACROSS THE CWA LATE
SATURDAY. WITH H5 SW FLOW WILL LOOK FOR MODERATING TEMPERATURES
THROUGH THE PERIOD. MOST OF THE PRECIPITATION WILL BE ON THE LIGHT
SIDE FRIDAY INTO SATURDAY WITH BREAKS THROUGHOUT THE PERIOD. WILL
STAY CLOSE TO GUIDANCE TEMPS FOR THE PERIOD.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 300 AM THURSDAY...EXPECT SUNDAY TO BE THE MORE ACTIVE DAY
OF THE WEEKEND WITH THE SPLIT FLOW PATTERN ACROSS THE US PHASING
IN ACROSS THE EASTERN HALF OF THE COUNTRY DURING THIS PERIOD AS H5
LOW AND SURFACE LOW MOVE INTO THE GREAT LAKES WITH DEVELOPING
TROUGH ACROSS THE CENTRAL U.S. H5 SW FLOW ACROSS THE SE WITH ABOVE
NORMAL TEMPERATURES EXPECTED ON SUNDAY AND THE GREATER RISK OF
RAIN AND POSSIBLE THUNDERSTORMS AHEAD OF ADVANCING COLD FRONT
MOVING INTO THE CAROLINAS. MODELS PEG THE FRONT ACROSS THE CWA
DURING LATE AFTERNOON INTO THE EARLY EVENING WITH BEST DYNAMICS AT
THIS TIME TO SUPPORT SOME ELEVATED CONVECTION AIDED BY DEPARTED H8
JET STREAK ACROSS THE REGION. WILL MAKE MENTION OF SLIGHT CHANCE
OF TSTM IN THE GRIDS FOR THE AFTERNOON/EVENING PERIOD. AS THE
FRONT EXITS THE COAST LATE SUNDAY AND H5 FLOW DAMPENS OUT BECOMING
MORE ZONAL FOR NEXT WEEK EXPECT SEASONABLE TO SLIGHTLY ABOVE CLIMO
TEMPS FOR NEXT WEEK FOR THE HIGHS AND CLEAR BUT COOLER OVERNIGHT
LOWS BELOW SLIGHTLY BELOW CLIMO AS CANADIAN HIGH PRESSURE BUILD IN
FORM THE WEST BUT STAYS TO OUR NORTH. GFS SEEMS TO WANT TO
DEVELOP A SURFACE LOW OFF THE SE COAST LATE IN THE PERIOD BUT ITS
FURTHER EAST THEN THE 31/00Z RUN OF LAST NIGHT AND WEAKER. THE
ECMWF HAS NOT HAD THIS FEATURE DURING THE PAST FEW RUNS SO WITH
HE GFS TRENDING WEAKER AND FURTHER EAST IT WILL NOT IMPACT THE
REGION TUESDAY INTO WEDNESDAY. H5 FLOW BECOMES MORE NW TOWARDS THE
END OF THE PERIOD AND WE START TO SEE COOLER TEMPS ARRIVE BY
THURSDAY INTO FRIDAY.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AS OF 12Z...CRE AND FLO WILL HAVE TO DEAL WITH FOG FOR THE FIRST
HOUR OR SO...OTHERWISE VFR CONDITIONS ARE EXPECTED THROUGH THE END
OF THE FORECAST PERIOD. HIGH PRESSURE WILL SHIFT OFFSHORE THIS
AFTERNOON...ALLOWING RETURN FLOW WITH INCREASING MID AND UPPER LEVEL
MOISTURE LATE THIS AFTERNOON THROUGH THE OVERNIGHT HOURS. SHOULD SEE
A MID CLOUD CEILING SOMETIME AFTER MIDNIGHT. THE INSULATING CLOUD
LAYER SHOULD KEEP FOG AT BAY. LIGHT SOUTHERLY FLOW TODAY WITH LIGHT
TO NEAR CALM WINDS TONIGHT.
EXTENDED OUTLOOK...VFR INTO FRI. CHANCE OF RAIN AND MVFR/TEMPO IFR
CONDITIONS FRI NIGHT THROUGH SUN. BECOMING VFR LATE SUN. VFR MON.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM THURSDAY...VERY FEW CHANGES WERE NEEDED TO THE
FORECAST. BASED ON LATEST HRRR AND RUC MODELS I HAVE BUMPED UP WIND
SPEEDS BETWEEN 1-5 PM BY A FEW KNOTS NEAR THE BEACHES WITH A WEAK
SEABREEZE CIRCULATION. WIND SPEEDS STILL WILL REMAIN LESS THAN 10
KT. SEAS ARE BARELY 1-2 FEET AND SHOULD CHANGE LITTLE THROUGH THE
DAY. E THE RULE TONIGHT. SEAS WILL BE 2 FT OR LESS THROUGH THE
PERIOD.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...WEAK BUBBLE HIGH ACROSS THE COASTAL WATERS
DURING FRIDAY WILL RESULT IN RELATIVELY LIGHT WINDS AND SEAS LESS
THAN 10 KT WITH SEAS 1-2 FEET NEAR SHORE AND 2-3 OFFSHORE.
SATURDAY THE WINDS INCREASE FROM THE EAST AS COASTAL TROUGH
OFFSHORE INTERACTS WITH THE FRONT TO UR WEST IN TIGHTENING THE
PRESSURE GRADIENT ACROSS THE WATERS. BY MID DAY SATURDAY EAST
WINDS OF 10-15 KTS NEAR SHORE AND 15-20 KTS OFFSHORE WILL START TO
BUILD SEAS TO 2-4 NEAR SHORE AND 3-5 FEET OFFSHORE APPROACHING 6
FEET IN THE OUTER MARINE ZONES BY LATE SATURDAY.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 300 AM THURSDAY...SMALL CRAFT ADVISORY CONDITIONS ARE
POSSIBLE SUNDAY AND MAYBE MONDAY AS FRONT APPROACHES THE COASTAL
WATERS AND WINDS VEER TO THE SW AND INCREASE TO 15-20 KTS NEAR
SHORE AND 20 TO 25 KTS OFFSHORE WITH BUILDING SEAS. WITH H8 JET
STREAK EXITING THE AREA AND THREAT OF ISOLATED THUNDERSTORMS SEAS
SHOULD REACT AND BUILD QUICKLY ON SUNDAY AND BE CHOPPY. FRONT
PASSES ACROSS THE COASTAL WATERS LATE SUNDAY NIGHT EARLY MONDAY
AND WINDS BECOME NORTHWEST STILL RATHER STRONG AT 15-20 KTS WILL
KEEP SEAS UP FOR THE EARLY PART OF MONDAY BEFORE SUBSIDING A BIT
BY AFTERNOON BUT NOT BY MUCH.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...RJD/TRA
SHORT TERM...MAC
LONG TERM...MAC
AVIATION...43
AREA FORECAST DISCUSSION
NWS TULSA OK
942 AM CST THU JAN 1 2015
.DISCUSSION...
THE FORECAST FOR TODAY HAS A HUGE BUST POTENTIAL. IT ALL HINGES
ON THE LOCATION OF THE FREEZING LINE AND IF THE HRRR QPF PANS
OUT. THE FREEZING LINE IS NOW LOCATED ACROSS SOUTHEAST OKLAHOMA
INTO WEST-CENTRAL ARKANSAS. HOWEVER...THERE MAY STILL SOME POCKETS OF
BELOW FREEZING TEMPERATURES IN THIS AREA. IT IS BASICALLY GOING TO
BE RACE BETWEEN THE PRECIPITATION SHIELD AND THE FREEZING LINE...TO
DETERMINE THE PRECIPITATION TYPE ACROSS NORTHEAST OKLAHOMA AND NORTHWEST
ARKANSAS THIS AFTERNOON. WILL CONTINUE WINTER WEATHER ADVISORY AS IT
IS FOR NOW WITH MAINLY FREEZING RAIN AND SLEET EXPECTED ACROSS NORTHEAST
OKLAHOMA AND NORTHWEST ARKANSAS THIS AFTERNOON. LIGHT ACCUMULATIONS OF
ICE ARE EXPECTED. HOWEVER...TRAVEL IMPACTS CAN BE GREAT WITH EVEN A THIN
GLAZE OF ICE. WILL MORE THAN LIKELY SEE MAINLY RAIN ACROSS THE SOUTH
WITH PATCHES OF SLEET.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...WINTER WEATHER ADVISORY UNTIL 6 PM THURSDAY FOR OKZ049-OKZ053-
OKZ060-OKZ061-OKZ062-OKZ063-OKZ064-OKZ065-OKZ066-OKZ067-
OKZ068-OKZ069-OKZ070-OKZ071-OKZ072-OKZ073-OKZ074-OKZ075-
OKZ076.
AR...WINTER WEATHER ADVISORY UNTIL 6 PM THURSDAY FOR ARZ001-ARZ002-
ARZ010-ARZ011-ARZ019-ARZ020-ARZ029.
&&
$$
SHORT TERM...10
AREA FORECAST DISCUSSION...UPDATED
NWS NORMAN OK
555 AM CST THU JAN 1 2015
.AVIATION...
01/12Z TAFS...PRIMARILY MVFR/IFR CONDITIONS EXPECTED MOST OF THE
FORECAST PERIOD. AREAS OF FREEZING DRIZZLE/FREEZING RAIN EXPECTED
TO AFFECT ALL BUT FAR NORTHERN OKLAHOMA TERMINALS...WHERE PRECIP
WILL MAINLY BE SNOW THIS MORNING INTO EARLY AFTERNOON. MOST
PERSISTENT LIGHT FZDZ/FZRA EXPECTED NEAR AND SOUTH OF KHBR AND
KOUN. BREAK IN MOST OF THE PRECIP EXPECTED TOWARD AND AFTER 20-22Z
BUT CIGS/VSBY WILL KEEP IFR/MVFR CONDITIONS GOING ALL BUT NORTHERN
OKLAHOMA SITES. WIDESPREAD FREEZING/FROZEN PRECIP EXPECTED TO
SPREAD OVER REGION JUST AFTER THIS TAF PERIOD AND LASTING MOST OF
THE DAY FRIDAY.
&&
.PREV DISCUSSION... /ISSUED 452 AM CST THU JAN 1 2015/
DISCUSSION...
WAVE NUMBER ONE OF PRECIPITATION IS ONGOING ACROSS SOUTHERN
OKLAHOMA AND WESTERN TEXAS THIS MORNING. RADAR TRENDS SHOW
ENHANCEMENT OF RADAR REFLECTIVITY IN THE TEXAS PANHANDLE. THE
CELLULAR STRUCTURE AND ENHANCED REFLECTIVITY SUGGEST THIS IS
ASSOCIATED WITH SLEET. BOTH THE HRRR AND RAP SUGGEST THIS WILL
CONTINUE TO DEVELOP AND MOVE EASTWARD WITH THE POTENTIAL FOR A
WINTRY MIX EVEN NORTH OF I-40 THIS MORNING INTO EARLY AFTERNOON.
THEREFORE...DECIDED TO EXPAND THE WINTER WEATHER ADVISORY FARTHER
NORTH.
WAVE NUMBER ONE WILL EXIT THE AREA LATE AFTERNOON INTO EARLY
EVENING. ATTENTION THEN TURNS TO SECOND WAVE OF PRECIPITATION THAT
IS ASSOCIATED WITH THE MAIN UPPER LEVEL LOW. A MORE WIDESPREAD
PRECIPITATION EVENT IS EXPECTED. PRECIPITATION WILL LIKELY DEVELOP
IN WESTERN NORTH TEXAS EARLY FRIDAY MORNING AND LIFT NORTHEASTWARD
THROUGH THE DAY FRIDAY. BECAUSE OF THE EARLY ONSET...THERE IS
CONCERN OF A SIGNIFICANT ICING EVENT ACROSS WESTERN NORTH TEXAS.
THE FORECAST ON FRIDAY WILL DEPEND ON THE EVOLUTION OF THE SFC 32F
WETBULB TEMPERATURE. LATEST GUIDANCE SUGGESTS THIS COULD BE VERY
CLOSE TO THE I-44 CORRIDOR BY FRIDAY AFTERNOON. OPTED FOR A MIX OF
RAIN/FREEZING RAIN ALONG I-44...WITH A FREEZING RAIN/SLEET MIX
NORTHWEST AND ALL RAIN SOUTHEAST.
A TRANSITION TO SNOW WILL OCCUR LATE FRIDAY INTO SATURDAY AS THE
UPPER LEVEL LOW PASSES THROUGH OKLAHOMA. BOTH THE PARALLEL GFS AND
ECMWF STILL SUGGEST THERE COULD BE ACCUMULATING SNOW IN NORTHERN
OKLAHOMA SATURDAY. THERE IS THE POTENTIAL THERE COULD BE ENOUGH
ACCUMULATING SNOW FOR HEADLINES. THE REST OF OKLAHOMA AND WESTERN
NORTH TEXAS COULD BE DRY SLOTTED SATURDAY.
AFTER COLLABORATION WITH SURROUNDING OFFICES...DECIDED TO HOLD
OFF ON ANY HEADLINES FOR FRIDAY AND SATURDAY. NEVERTHELESS...HEADLINES
WILL LIKELY BE REQUIRED FOR PARTS OF THE AREA FRIDAY INTO SATURDAY
FOR ACCUMULATING ICE AND/OR SNOW. STAY-TUNED!
BEYOND SATURDAY...A RATHER COLD DAY IS EXPECTED ON SUNDAY BEHIND THE
STORM SYSTEM. TEMPERATURES WILL SLOWLY MODERATE BEFORE ANOTHER COLD
FRONT APPROACHES THE REGION AROUND MID-WEEK. THE FORECAST IS DRY
BEYOND SATURDAY.
MAHALE
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 30 27 34 31 / 70 20 60 70
HOBART OK 28 24 33 29 / 80 20 50 60
WICHITA FALLS TX 30 29 34 32 / 90 60 80 70
GAGE OK 29 18 33 22 / 30 0 20 40
PONCA CITY OK 31 24 33 30 / 30 10 30 70
DURANT OK 32 32 36 36 / 90 50 80 80
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR
OKZ021>048-050>052.
TX...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR
TXZ083>090.
&&
$$
11/10/11
AREA FORECAST DISCUSSION
NWS NORMAN OK
452 AM CST THU JAN 1 2015
.DISCUSSION...
WAVE NUMBER ONE OF PRECIPITATION IS ONGOING ACROSS SOUTHERN
OKLAHOMA AND WESTERN TEXAS THIS MORNING. RADAR TRENDS SHOW
ENHANCEMENT OF RADAR REFLECTIVITY IN THE TEXAS PANHANDLE. THE
CELLULAR STRUCTURE AND ENHANCED REFLECTIVITY SUGGEST THIS IS
ASSOCIATED WITH SLEET. BOTH THE HRRR AND RAP SUGGEST THIS WILL
CONTINUE TO DEVELOP AND MOVE EASTWARD WITH THE POTENTIAL FOR A
WINTRY MIX EVEN NORTH OF I-40 THIS MORNING INTO EARLY AFTERNOON.
THEREFORE...DECIDED TO EXPAND THE WINTER WEATHER ADVISORY FARTHER
NORTH.
WAVE NUMBER ONE WILL EXIT THE AREA LATE AFTERNOON INTO EARLY
EVENING. ATTENTION THEN TURNS TO SECOND WAVE OF PRECIPITATION THAT
IS ASSOCIATED WITH THE MAIN UPPER LEVEL LOW. A MORE WIDESPREAD
PRECIPITATION EVENT IS EXPECTED. PRECIPITATION WILL LIKELY DEVELOP
IN WESTERN NORTH TEXAS EARLY FRIDAY MORNING AND LIFT NORTHEASTWARD
THROUGH THE DAY FRIDAY. BECAUSE OF THE EARLY ONSET...THERE IS
CONCERN OF A SIGNIFICANT ICING EVENT ACROSS WESTERN NORTH TEXAS.
THE FORECAST ON FRIDAY WILL DEPEND ON THE EVOLUTION OF THE SFC 32F
WETBULB TEMPERATURE. LATEST GUIDANCE SUGGESTS THIS COULD BE VERY
CLOSE TO THE I-44 CORRIDOR BY FRIDAY AFTERNOON. OPTED FOR A MIX OF
RAIN/FREEZING RAIN ALONG I-44...WITH A FREEZING RAIN/SLEET MIX
NORTHWEST AND ALL RAIN SOUTHEAST.
A TRANSITION TO SNOW WILL OCCUR LATE FRIDAY INTO SATURDAY AS THE
UPPER LEVEL LOW PASSES THROUGH OKLAHOMA. BOTH THE PARALLEL GFS AND
ECMWF STILL SUGGEST THERE COULD BE ACCUMULATING SNOW IN NORTHERN
OKLAHOMA SATURDAY. THERE IS THE POTENTIAL THERE COULD BE ENOUGH
ACCUMULATING SNOW FOR HEADLINES. THE REST OF OKLAHOMA AND WESTERN
NORTH TEXAS COULD BE DRY SLOTTED SATURDAY.
AFTER COLLABORATION WITH SURROUNDING OFFICES...DECIDED TO HOLD
OFF ON ANY HEADLINES FOR FRIDAY AND SATURDAY. NEVERTHELESS...HEADLINES
WILL LIKELY BE REQUIRED FOR PARTS OF THE AREA FRIDAY INTO SATURDAY
FOR ACCUMULATING ICE AND/OR SNOW. STAY-TUNED!
BEYOND SATURDAY...A RATHER COLD DAY IS EXPECTED ON SUNDAY BEHIND THE
STORM SYSTEM. TEMPERATURES WILL SLOWLY MODERATE BEFORE ANOTHER COLD
FRONT APPROACHES THE REGION AROUND MID-WEEK. THE FORECAST IS DRY
BEYOND SATURDAY.
MAHALE
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 30 27 34 31 / 70 20 60 70
HOBART OK 28 24 33 29 / 80 20 50 60
WICHITA FALLS TX 30 29 34 32 / 90 60 80 70
GAGE OK 29 18 33 22 / 30 0 20 40
PONCA CITY OK 31 24 33 30 / 30 10 30 70
DURANT OK 32 32 36 36 / 90 50 80 80
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR
OKZ021>048-050>052.
TX...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR
TXZ083>090.
&&
$$
11/10
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
714 AM CST THU JAN 1 2015
.UPDATE...
PLEASE SEE THE 12Z AVIATION DISCUSSION BELOW.
&&
.AVIATION...
CIGS WILL CONTINUE TO LOWER THROUGHOUT THE DAY AS LIGHT PRECIPITATION
CONTINUES TO MOVE FROM SOUTHWEST TO NORTHEAST ACROSS THE REGION.
MOST TAF SITES ARE EITHER CURRENTLY IFR OR WILL DROP INTO IFR
WITHIN THE NEXT COUPLE OF HOURS. ALL LIQUID PRECIPITATION IS
EXPECTED AT OUR TAF SITES AS TEMPERATURES REMAIN ABOVE FREEZING.
&&
.PREV DISCUSSION... /ISSUED 417 AM CST THU JAN 1 2015/
SHORT TERM (TODAY THROUGH FRIDAY)...
LIGHT FREEZING PRECIPITATION CONTINUES OVER THE ADVY AND WARNING
AREAS OF THE SRN EDWARDS PLATEAU...HILL COUNTRY AND BALCONES
ESCARPMENT. A CLUSTER OF WEAK THUNDERSTORMS CROSSED FROM NRN
MEXICO AND LOOKS TO BE PRODUCING A BRIGHT BAND OF WHAT IS PROBABLY
SNOW MELTING INTO RAIN AND POSSIBLY A PARTIAL MELT/REFREEZE TO
SLEET AND GRAUPEL. THIS CONVECTIVE AREA IS LOSING THE CELLULAR
STRUCTURE AND SHOULD CONTINUE TO WEAKEN AS IT LIFTS NE. THUS WILL
LEAVE OUT THE MENTION OF THUNDER AND LET NOWCASTS HANDLE WHAT
SHOULD BE A SHORT-LIVED EVENT.
THE DAYBREAK EMERGENCE OF CONVECTIVE SLEET BAND IS EXPECTED TO
TRACK RIGHT ALONG THE EASTERN PART OF THE BALCONES ESCARPMENT.
THUS AM HESITANT TO WARM MORNING TEMPERATURE FORECASTS TO MATCH
THE CURRENT TRENDS HOLDING ABOVE FREEZING. HI-RES MODELS HAVE KEPT
WITH THE CONVECTIVE BANDING AREA FORMING FARTHER NORTH...BUT THE
LATEST RUNS OF THE HRRR DEPICT THE ONGOING CONVECTIVE AREA WELL
AND SEND IT ACROSS THE AUSTIN METRO AREA AND NW PART OF THE SAN
ANTONIO METRO AREA THROUGH DAYBREAK. WHILE THIS CLUSTER OF
MODERATE PRECIPITATION COULD LOWER TEMPS TO FREEZING
BRIEFLY...EXPECT THE WEAKENING TREND TO ALLOW MOST AREAS IN THE
ADVISORY TO HOLD ONTO ABOVE FREEZING TEMPERATURES WITH MORE
ISOLATED FROZEN CONDITIONS POSSIBLE AT HIGHER ELEVATIONS. A
SECONDARY CONVECTIVE BAND REMAINS IN THE HRRR PICTURE WHICH SHOULD
POTENTIALLY ADD TO THE FREEZING RAIN/SLEET MIX OVER THE WARNING
AREA AT AROUND DAYBREAK. THUS THE ONGOING WINTER STORM WARNING AND
WINTER WEATHER ADVISORY AREA IS THUS CONSIDERED APPROPRIATE AND NO
WSW UPDATES ARE PLANNED.
THE CONSENSUS MODEL POPULATION OF THE TEMPERATURES IN THE GRIDDED
DATA SUGGESTED A QUICK WARM- UP TO ABOVE FREEZING...BUT WE FAVOR A
MORE GRADUAL RISE IN THE MORNING PERIOD WHERE ICING HAS OCCURRED.
BY NOON...MODEL SOUNDINGS SUGGEST THERE SHOULD BE AMPLE TIME FOR
THE WARMING TO HAVE OCCURRED...AS THE FRONTAL INVERSION SHOULD
CONTINUE TO BE MODIFIED BY FALLING RAIN AND DRIZZLE. A COLD RAIN
REMAINS IN THE PICTURE THROUGH FRIDAY. TEMPERATURES SHOULD BE
ALMOST FLAT FROM THIS AFTERNOON THROUGH LATE FRIDAY MORNING BEFORE
WARMING INTO THE 40S OVER MOST AREAS LATE FRIDAY. DESPITE THE HIGH
POPS BENEATH THE SOLID OVERRUNNING PATTERN...QPF AMOUNTS REMAIN
CONSERVATIVE AND GENERALLY BELOW 1/2 INCH.
LONG TERM (FRIDAY NIGHT THROUGH WEDNESDAY)...
THE EASTWARD EJECTION OF A SLOW MOVING UPPER LOW BRINGS A SLIGHTLY
MORE CONVECTIVE ENVIRONMENT TO TX BY FRIDAY EVENING. THE INCREASED
POTENTIAL FOR THUNDER TRANSLATES TO SLIGHTLY HIGHER QPF AMOUNTS
WITH ANOTHER 1/2 INCH OF RAIN POSSIBLE IN THE FRIDAY NIGHT PERIOD
ALONE.
MODEL CONSENSUS REMAINS IN GOOD AGREEMENT TO BRING DECREASING
CLOUDS AND RAIN CHANCES BY MIDDAY SATURDAY AND PROBABLY THE
WARMEST TEMPS OF THE WEEK. THIS IS BECAUSE ANOTHER FRONT ARRIVES
BY SUNDAY MORNING. THE ECMWF TRENDED SHARPLY COLDER FROM THIS
FRONT WITH A MUCH ENHANCED POLAR TROUGH OVER THE EASTERN US. THE
GFS HAS ALSO TRENDED SLIGHTLY COLDER...SO A BLEND OF THESE TWO
MODELS LOOKS REASONABLE. AM HESITANT TO BUY INTO THE ECMWF BASED
GUIDANCE THAT PROJECTED MIDDLE TEENS OVER THE HILL COUNTRY MONDAY
MORNING. THE COLD PATTERN IS SHOWN BY BOTH THE GFS AND ECMWF
SOLUTIONS TO BE SHORT-LIVED WITH A PROGRESSIVE ZONAL PATTERN
PUSHING AN UPPER RIDGE OVER TX BY MIDWEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 39 38 43 40 59 / 80 90 80 80 30
AUSTIN BERGSTROM INTL AIRPORT 40 37 43 39 58 / 80 90 80 80 30
NEW BRAUNFELS MUNI AIRPORT 41 39 45 42 61 / 70 80 70 80 30
BURNET MUNI AIRPORT 38 35 40 37 57 / 90 90 80 80 20
DEL RIO INTL AIRPORT 41 41 49 41 61 / 40 50 40 50 -
GEORGETOWN MUNI AIRPORT 40 36 41 38 56 / 90 90 80 80 30
HONDO MUNI AIRPORT 41 39 47 40 62 / 50 60 50 60 20
SAN MARCOS MUNI AIRPORT 40 38 44 41 59 / 70 80 70 80 30
LA GRANGE - FAYETTE REGIONAL 43 41 47 44 59 / 70 70 80 80 40
SAN ANTONIO INTL AIRPORT 41 39 46 42 61 / 60 80 60 70 20
STINSON MUNI AIRPORT 42 40 46 42 62 / 60 70 60 70 20
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR THE FOLLOWING
COUNTIES: BEXAR...COMAL...HAYS...KINNEY...MEDINA...TRAVIS...
UVALDE...WILLIAMSON.
WINTER STORM WARNING UNTIL NOON CST TODAY FOR THE FOLLOWING
COUNTIES: BANDERA...BLANCO...BURNET...EDWARDS...GILLESPIE...
KENDALL...KERR...LLANO...REAL...VAL VERDE.
&&
$$
MESOSCALE/AVIATION...18
SYNOPTIC/GRIDS...24
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
417 AM CST THU JAN 1 2015
.SHORT TERM (TODAY THROUGH FRIDAY)...
LIGHT FREEZING PRECIPITATION CONTINUES OVER THE ADVY AND WARNING
AREAS OF THE SRN EDWARDS PLATEAU...HILL COUNTRY AND BALCONES
ESCARPMENT. A CLUSTER OF WEAK THUNDERSTORMS CROSSED FROM NRN
MEXICO AND LOOKS TO BE PRODUCING A BRIGHT BAND OF WHAT IS PROBABLY
SNOW MELTING INTO RAIN AND POSSIBLY A PARTIAL MELT/REFREEZE TO
SLEET AND GRAUPEL. THIS CONVECTIVE AREA IS LOSING THE CELLULAR
STRUCTURE AND SHOULD CONTINUE TO WEAKEN AS IT LIFTS NE. THUS WILL
LEAVE OUT THE MENTION OF THUNDER AND LET NOWCASTS HANDLE WHAT
SHOULD BE A SHORT-LIVED EVENT.
THE DAYBREAK EMERGENCE OF CONVECTIVE SLEET BAND IS EXPECTED TO
TRACK RIGHT ALONG THE EASTERN PART OF THE BALCONES ESCARPMENT.
THUS AM HESITANT TO WARM MORNING TEMPERATURE FORECASTS TO MATCH
THE CURRENT TRENDS HOLDING ABOVE FREEZING. HI-RES MODELS HAVE KEPT
WITH THE CONVECTIVE BANDING AREA FORMING FARTHER NORTH...BUT THE
LATEST RUNS OF THE HRRR DEPICT THE ONGOING CONVECTIVE AREA WELL
AND SEND IT ACROSS THE AUSTIN METRO AREA AND NW PART OF THE SAN
ANTONIO METRO AREA THROUGH DAYBREAK. WHILE THIS CLUSTER OF
MODERATE PRECIPITATION COULD LOWER TEMPS TO FREEZING
BRIEFLY...EXPECT THE WEAKENING TREND TO ALLOW MOST AREAS IN THE
ADVISORY TO HOLD ONTO ABOVE FREEZING TEMPERATURES WITH MORE
ISOLATED FROZEN CONDITIONS POSSIBLE AT HIGHER ELEVATIONS. A
SECONDARY CONVECTIVE BAND REMAINS IN THE HRRR PICTURE WHICH SHOULD
POTENTIALLY ADD TO THE FREEZING RAIN/SLEET MIX OVER THE WARNING
AREA AT AROUND DAYBREAK. THUS THE ONGOING WINTER STORM WARNING AND
WINTER WEATHER ADVISORY AREA IS THUS CONSIDERED APPROPRIATE AND NO
WSW UPDATES ARE PLANNED.
THE CONSENSUS MODEL POPULATION OF THE TEMPERATURES IN THE GRIDDED
DATA SUGGESTED A QUICK WARM- UP TO ABOVE FREEZING...BUT WE FAVOR A
MORE GRADUAL RISE IN THE MORNING PERIOD WHERE ICING HAS OCCURRED.
BY NOON...MODEL SOUNDINGS SUGGEST THERE SHOULD BE AMPLE TIME FOR
THE WARMING TO HAVE OCCURRED...AS THE FRONTAL INVERSION SHOULD
CONTINUE TO BE MODIFIED BY FALLING RAIN AND DRIZZLE. A COLD RAIN
REMAINS IN THE PICTURE THROUGH FRIDAY. TEMPERATURES SHOULD BE
ALMOST FLAT FROM THIS AFTERNOON THROUGH LATE FRIDAY MORNING BEFORE
WARMING INTO THE 40S OVER MOST AREAS LATE FRIDAY. DESPITE THE HIGH
POPS BENEATH THE SOLID OVERRUNNING PATTERN...QPF AMOUNTS REMAIN
CONSERVATIVE AND GENERALLY BELOW 1/2 INCH.
&&
.LONG TERM (FRIDAY NIGHT THROUGH WEDNESDAY)...
THE EASTWARD EJECTION OF A SLOW MOVING UPPER LOW BRINGS A SLIGHTLY
MORE CONVECTIVE ENVIRONMENT TO TX BY FRIDAY EVENING. THE INCREASED
POTENTIAL FOR THUNDER TRANSLATES TO SLIGHTLY HIGHER QPF AMOUNTS
WITH ANOTHER 1/2 INCH OF RAIN POSSIBLE IN THE FRIDAY NIGHT PERIOD
ALONE.
MODEL CONSENSUS REMAINS IN GOOD AGREEMENT TO BRING DECREASING
CLOUDS AND RAIN CHANCES BY MIDDAY SATURDAY AND PROBABLY THE
WARMEST TEMPS OF THE WEEK. THIS IS BECAUSE ANOTHER FRONT ARRIVES
BY SUNDAY MORNING. THE ECMWF TRENDED SHARPLY COLDER FROM THIS
FRONT WITH A MUCH ENHANCED POLAR TROUGH OVER THE EASTERN US. THE
GFS HAS ALSO TRENDED SLIGHTLY COLDER...SO A BLEND OF THESE TWO
MODELS LOOKS REASONABLE. AM HESITANT TO BUY INTO THE ECMWF BASED
GUIDANCE THAT PROJECTED MIDDLE TEENS OVER THE HILL COUNTRY MONDAY
MORNING. THE COLD PATTERN IS SHOWN BY BOTH THE GFS AND ECMWF
SOLUTIONS TO BE SHORT-LIVED WITH A PROGRESSIVE ZONAL PATTERN
PUSHING AN UPPER RIDGE OVER TX BY MIDWEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 39 38 43 40 59 / 80 90 80 80 30
AUSTIN BERGSTROM INTL AIRPORT 40 37 43 39 58 / 80 90 80 80 30
NEW BRAUNFELS MUNI AIRPORT 41 39 45 42 61 / 70 80 70 80 30
BURNET MUNI AIRPORT 38 35 40 37 57 / 90 90 80 80 20
DEL RIO INTL AIRPORT 41 41 49 41 61 / 40 50 40 50 -
GEORGETOWN MUNI AIRPORT 40 36 41 38 56 / 90 90 80 80 30
HONDO MUNI AIRPORT 41 39 47 40 62 / 50 60 50 60 20
SAN MARCOS MUNI AIRPORT 40 38 44 41 59 / 70 80 70 80 30
LA GRANGE - FAYETTE REGIONAL 43 41 47 44 59 / 70 70 80 80 40
SAN ANTONIO INTL AIRPORT 41 39 46 42 61 / 60 80 60 70 20
STINSON MUNI AIRPORT 42 40 46 42 62 / 60 70 60 70 20
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR THE FOLLOWING
COUNTIES: BEXAR...COMAL...HAYS...KINNEY...MEDINA...TRAVIS...
UVALDE...WILLIAMSON.
WINTER STORM WARNING UNTIL NOON CST TODAY FOR THE FOLLOWING
COUNTIES: BANDERA...BLANCO...BURNET...EDWARDS...GILLESPIE...
KENDALL...KERR...LLANO...REAL...VAL VERDE.
&&
$$
MESOSCALE/AVIATION...24
SYNOPTIC/GRIDS...18
AREA FORECAST DISCUSSION...UPDATE FOR AVIATION
NWS LITTLE ROCK AR
1150 AM CST THU JAN 1 2015
.AVIATION...
OVERALL VFR CEILINGS AND FLIGHT CONDITIONS WILL START THE FORECAST.
THE AREA OF MAINLY LIGHT TO PATCHY MODERATE RAIN...WITH A FEW SPOTS
MIXED WITH LIGHT SLEET OR LIGHT FREEZING RAIN IN WESTERN TO
NORTHWEST AR...ARE SPREADING OVER AR. TEMPS WILL HOLD ABOVE FREEZING
OVER MOST LOCALS AND RAIN WILL BE SEEN...WITH THE GREATEST CHANCE OF
LIGHT SLEET OR LIGHT FREEZING RAIN IN WESTERN TO NORTHERN AR. PATCHY
MVFR CEILINGS WILL BE POSSIBLE WITH THE HEAVIER PRECIP AREAS. WINDS
ARE LIGHT FROM THE NE TO SE. TONIGHT...CEILINGS WILL GRADUALLY LOWER
TO MAINLY MVFR CONDITIONS WITH THE LIGHT TO AT TIMES MODERATE RAIN.
PATCHY LIGHT FREEZING RAIN AND SLEET MAY BE SEEN OVER WESTERN AND
NORTHERN AR. ICING WILL BE POSSIBLE IN CLOUDS. THE CHANCE OF RAIN
WILL CONTINUE ON FRIDAY. (59)
&&
.PREV DISCUSSION... /ISSUED 1059 AM CST THU JAN 1 2015/
.UPDATE...
PRECIPITATION HAS INCREASED ACROSS PORTIONS OF SOUTHEAST ARKANSAS
THROUGH THE MORNING HOURS...WITH ONLY A FEW BRIEF REPORTS OF SLEET
COMING IN. TEMPERATURES AROUND THE STATE THIS MORNING NOW HAVE
MOSTLY RISEN ABOVE FREEZING. THE FEW EXCEPTIONS ARE IN THE HIGHER
ELEVATIONS ACROSS WESTERN AND NORTHWEST ARKANSAS. HRRR CONTINUES
TO BRING A SECOND ROUND OF PRECIPITATION ACROSS NORTHWEST ARKANSAS
LATER THIS AFTERNOON. DO FULLY EXPECT SOME EVAPORATIVE COOLING
THROUGH THE DAY TODAY AS ENVIRONMENT MOISTENS UP. CURRENT THINKING
IS THAT THIS WILL HAVE NO NET EFFECT ON TEMPS AND THEY WILL REMAIN
STATIONARY THROUGH THE AFTERNOON. FORECAST IS IN GOOD SHAPE...AND
JUST MADE SOME MINOR TWEAKS TO TEMPERATURES TO REFLECT THE CURRENT
TRENDS.
&&
.PREV DISCUSSION... /ISSUED 625 AM CST THU JAN 1 2015/
AVIATION...01/12Z TAF CYCLE
VFR CONDS WL START OFF THE PD...BUT CONDS WL DETERIORATE TODAY AS
PRECIP DVLPS AND OVERSPREADS THE FA. PARTS OF WRN AND NRN AR WL
SEE A MIX OF LGT FRZG RAIN AND SLEET THIS MRNG BEFORE CHANGING OVR
TO JUST RAIN BY THIS AFTN. SOME FRZG DRIZZLE WL BE POSSIBLE TNGT
OVR NRN AR. ELSEWHERE...A BRIEF PD OF RAIN AND SLEET WL OCCUR THIS
MRNG BEFORE PRECIP BCMS JUST A COLD RAIN. /44/
PREV DISCUSSION... /ISSUED 231 AM CST THU JAN 1 2015/
SHORT TERM...TODAY THROUGH SUNDAY
TEMPS ACROSS THE CWA THIS MORNING ARE REMAINING STEADY IN THE 30S
FOR MOST LOCATIONS...WITH MOST LOCATIONS ABOVE FREEZING. THE CLOUD
COVER HAS KEPT THESE TEMPS FROM FALLING...AND WILL LIKELY SEE TEMPS
REMAIN STEADY THROUGH SUNRISE. DRY AIR IS IN PLACE HOWEVER...WITH
DEWPTS IN THE UPPER TEENS TO MID 20S. WATER VAPOR IMAGERY IS SHOWING
A MOISTURE PLUME STRETCHING FROM THE PACIFIC...LIFTING NE INTO TX
AND OK THIS MORNING...WITH PRECIP EVIDENT IN NRN TX AND RECENTLY SRN
OK AS SEEN IN REGIONAL RADAR IMAGERY.
AS THIS MOISTURE APPROACHES THE WRN AND SWRN COUNTIES THIS
MORNING...DO EXPECT SOME EVAPORATIVE COOLING AS MOISTURE FALLS
THROUGH THE DRY LAYER NEAR THE SFC. HAVE TEMPS DROPPING SEVERAL DEG
AT THE ONSET OF PRECIP...WHICH WILL BE THE PRIMARY TIME FOR ANY
WINTRY PRECIP. INITIALLY...A PERIOD OF SLEET AND FREEZING RAIN WILL
BE SEEN AS THE COLUMN SATURATES DURING THE MORNING HRS. GIVEN TEMPS
ARE ALREADY WARMER THAN EARLIER EXPECTED AT THIS TIME...THE
POTENTIAL FOR WIDESPREAD WINTER WX HAZARDS IS EVEN LOWER THAN
EARLIER EXPECTED. AS A RESULT...THINKING ANY SLEET OR ICE
ACCUMULATIONS WILL BE LIGHT...AND LIMITED TO THE HIGHER TERRAIN OF
THE OUACHITAS AND OZARKS...AND OTHER ISOLATED AREAS ACROSS THE FAR
WRN AND NWRN COUNTIES. ANY TRAVEL HAZARDS THIS NEW YEARS MORNING
WILL BE LIMITED TO THESE LOCATIONS...ESPECIALLY ON BRIDGES AND
OVERPASSES. WILL CONTINUE TO EMPHASIZE ANY WINTRY WX TRAVEL CONCERNS
IN AN UPDATED SPS THIS MORNING.
LOCATIONS FURTHER EAST WILL ALSO SEE SOME SLEET OR PATCHY FREEZING
RAIN AT THE ONSET OF THE PRECIP...BUT TEMPS THROUGHOUT THE ENTIRE
THERMAL PROFILE WILL WARM OVER TIME...LEADING TO JUST A COLD RAIN BY
LATER THIS MORNING AND ESPECIALLY THIS AFTERNOON. THE HIGHEST PRECIP
RATES WILL BE ACROSS THE SRN HALF OF THE CWA WHERE TEMPS ARE
WARMEST. LIGHTER PRECIP RATES WILL BE SEEN ACROSS THE NRN
COUNTIES...WHERE TEMPS MAY REMAIN COLD ENOUGH THIS AFTERNOON TO SEE
SOME FREEZING RAIN MIX WITH THE RAIN...ESPECIALLY IN THE HIGHER
TERRAIN OF THE OZARKS AND NEAR THE MO BORDER. ONLY MINOR ICE
ACCUMULATIONS ARE EXPECTED THIS AFTERNOON IN AREAS WHERE THE
FREEZING RAIN OCCURS.
THIS EVENING...MOST LOCATIONS WILL SEE ALL RAINFALL AS TEMPS WILL
REMAIN STEADY OR EVEN WARM A DEG OR TWO BY FRI MORNING. MOST OF THE
PRECIP ACTIVITY WILL ALSO HAVE SHIFTED FURTHER SOUTH...WITH NRN
LOCATIONS LIKELY SEEING DRY CONDITIONS TONIGHT. AS A
RESULT...DROP POPS ALONG THE MO BORDER TO ONLY SLIGHT CHANCE. IF
ANY PRECIP WERE TO FALL ACROSS THE NRN COUNTIES...MAINLY RAIN IS
EXPECTED...THOUGH A FEW SPOTS IN THE HIGHER TERRAIN COULD AGAIN SEE
SOME FREEZING RAIN MIX IN WITH THE RAIN.
EVEN THIS CLOSE TO THE ONSET OF THIS MINOR WINTER WX EPISODE...THERE
DOES REMAIN SOME UNCERTAINTY REGARDING TEMPS. SOME ADJUSTMENTS IN
THE FORECAST REMAIN POSSIBLE...ESPECIALLY CONSIDERING SOME LOCATIONS
WILL BE SO NEAR THE FREEZING MARK. ANY CHANGES IN THE EXPECTED TEMPS
COULD ALTER THE POTENTIAL FROZEN PRECIP ACCUMULATION...RESULTING IN
INCREASED WINTER WX TRAVEL HAZARDS. PLEASE REFER TO THE LATEST
FORECASTS UPDATES THIS NEW YEARS DAY...ESPECIALLY IN THE HIGHER
TERRAIN OF THE OUACHITAS AND OZARKS...THE WRN COUNTIES...AND AREAS
ALONG THE MO BORDER.
ENOUGH WARMING WILL HAVE OCCURRED FOR FRI INTO SAT TO SEE ALL LIQUID
PRECIP. THE SW FLOW ALOFT WILL INTENSIFY FRI INTO SAT...WITH
WIDESPREAD SHRA AND EVEN SOME RUMBLES OF THUNDER POSSIBLE ACROSS THE
CWA. SOME LOCALLY HEAVY RAINFALL WILL ALSO BE POSSIBLE...THOUGH ONLY
WIDESPREAD RAINFALL AMOUNTS OF 1 TO 2 INCHES ARE CURRENTLY EXPECTED.
AS A RESULT...A FLASH FLOOD WATCH IS NOT EXPECTED AT THIS TIME.
THE STORM SYSTEM WILL EXIT THE REGION SAT INTO SAT NIGHT...WITH
DRIER AIR MOVING INTO THE STATE BY THE AFTERNOON HRS SAT. AS A
RESULT...HAVE POPS DECREASING RAPIDLY BY SAT AFTERNOON FROM SW TO
NE. SOME LINGERING MOISTURE COULD BE SEEN ACROSS THE NRN COUNTIES
SAT NIGHT...WITH SOME SPRINKLES OR A FEW SNOW FLAKES POSSIBLE.
A COLD FRONT WILL SURGE THROUGH THE STATE ON SUN...WITH COLDER AND
DRIER CONDITIONS MOVING INTO THE REGION. CHANCES FOR ANY PRECIP WILL
BE LOW TO END THE SHORT TERM PERIOD.
LONG TERM...MONDAY THROUGH WEDNESDAY
MODELS ARE IN DECENT AGREEMENT THIS MRNG WITH OVERALL FCST TRENDS
THRU THE PD. A WESTERLY FLOW ALOFT ON MON WL EVENTUALLY TURN NWLY
FOR TUE AND WED AS A LONG WV TROF SHARPENS OVR THE ERN HALF OF THE
NATION. AS A RESULT...A SERIES OF CLIPPER TYPE SFC LOWS WL DROP SEWD
AND BRING REINFORCING SHOTS OF COLDER AIR TO AR THRU THE MIDDLE OF
THE WEEK. WITH LTL IN THE WAY OF LOW LVL MOISTURE RETURN
ANTICIPATED...THE FCST WL RMN DRY.
&&
.PRELIMINARY POINT TEMPS/POPS...
BATESVILLE AR 37 34 40 36 / 50 40 80 80
CAMDEN AR 36 36 42 40 / 100 80 90 80
HARRISON AR 35 32 40 34 / 30 20 50 80
HOT SPRINGS AR 37 34 41 38 / 90 60 90 80
LITTLE ROCK AR 38 35 41 38 / 80 60 90 80
MONTICELLO AR 37 35 42 42 / 100 80 90 80
MOUNT IDA AR 38 34 41 37 / 90 60 90 80
MOUNTAIN HOME AR 34 33 41 35 / 30 20 50 80
NEWPORT AR 37 34 40 38 / 50 50 80 80
PINE BLUFF AR 37 35 41 40 / 90 80 90 80
RUSSELLVILLE AR 37 34 41 37 / 80 40 80 80
SEARCY AR 36 33 40 37 / 60 50 90 80
STUTTGART AR 37 34 41 39 / 90 60 90 80
&&
.LZK WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
65
AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
1059 AM CST THU JAN 1 2015
.UPDATE...
PRECIPITATION HAS INCREASED ACROSS PORTIONS OF SOUTHEAST ARKANSAS
THROUGH THE MORNING HOURS...WITH ONLY A FEW BRIEF REPORTS OF SLEET
COMING IN. TEMPERATURES AROUND THE STATE THIS MORNING NOW HAVE
MOSTLY RISEN ABOVE FREEZING. THE FEW EXCEPTIONS ARE IN THE HIGHER
ELEVATIONS ACROSS WESTERN AND NORTHWEST ARKANSAS. HRRR CONTINUES
TO BRING A SECOND ROUND OF PRECIPITATION ACROSS NORTHWEST ARKANSAS
LATER THIS AFTERNOON. DO FULLY EXPECT SOME EVAPORATIVE COOLING
THROUGH THE DAY TODAY AS ENVIRONMENT MOISTENS UP. CURRENT THINKING
IS THAT THIS WILL HAVE NO NET EFFECT ON TEMPS AND THEY WILL REMAIN
STATIONARY THROUGH THE AFTERNOON. FORECAST IS IN GOOD SHAPE...AND
JUST MADE SOME MINOR TWEAKS TO TEMPERATURES TO REFLECT THE CURRENT
TRENDS.
&&
.PREV DISCUSSION... /ISSUED 625 AM CST THU JAN 1 2015/
AVIATION...01/12Z TAF CYCLE
VFR CONDS WL START OFF THE PD...BUT CONDS WL DETERIORATE TODAY AS
PRECIP DVLPS AND OVERSPREADS THE FA. PARTS OF WRN AND NRN AR WL
SEE A MIX OF LGT FRZG RAIN AND SLEET THIS MRNG BEFORE CHANGING OVR
TO JUST RAIN BY THIS AFTN. SOME FRZG DRIZZLE WL BE POSSIBLE TNGT
OVR NRN AR. ELSEWHERE...A BRIEF PD OF RAIN AND SLEET WL OCCUR THIS
MRNG BEFORE PRECIP BCMS JUST A COLD RAIN. /44/
PREV DISCUSSION... /ISSUED 231 AM CST THU JAN 1 2015/
SHORT TERM...TODAY THROUGH SUNDAY
TEMPS ACROSS THE CWA THIS MORNING ARE REMAINING STEADY IN THE 30S
FOR MOST LOCATIONS...WITH MOST LOCATIONS ABOVE FREEZING. THE CLOUD
COVER HAS KEPT THESE TEMPS FROM FALLING...AND WILL LIKELY SEE TEMPS
REMAIN STEADY THROUGH SUNRISE. DRY AIR IS IN PLACE HOWEVER...WITH
DEWPTS IN THE UPPER TEENS TO MID 20S. WATER VAPOR IMAGERY IS SHOWING
A MOISTURE PLUME STRETCHING FROM THE PACIFIC...LIFTING NE INTO TX
AND OK THIS MORNING...WITH PRECIP EVIDENT IN NRN TX AND RECENTLY SRN
OK AS SEEN IN REGIONAL RADAR IMAGERY.
AS THIS MOISTURE APPROACHES THE WRN AND SWRN COUNTIES THIS
MORNING...DO EXPECT SOME EVAPORATIVE COOLING AS MOISTURE FALLS
THROUGH THE DRY LAYER NEAR THE SFC. HAVE TEMPS DROPPING SEVERAL DEG
AT THE ONSET OF PRECIP...WHICH WILL BE THE PRIMARY TIME FOR ANY
WINTRY PRECIP. INITIALLY...A PERIOD OF SLEET AND FREEZING RAIN WILL
BE SEEN AS THE COLUMN SATURATES DURING THE MORNING HRS. GIVEN TEMPS
ARE ALREADY WARMER THAN EARLIER EXPECTED AT THIS TIME...THE
POTENTIAL FOR WIDESPREAD WINTER WX HAZARDS IS EVEN LOWER THAN
EARLIER EXPECTED. AS A RESULT...THINKING ANY SLEET OR ICE
ACCUMULATIONS WILL BE LIGHT...AND LIMITED TO THE HIGHER TERRAIN OF
THE OUACHITAS AND OZARKS...AND OTHER ISOLATED AREAS ACROSS THE FAR
WRN AND NWRN COUNTIES. ANY TRAVEL HAZARDS THIS NEW YEARS MORNING
WILL BE LIMITED TO THESE LOCATIONS...ESPECIALLY ON BRIDGES AND
OVERPASSES. WILL CONTINUE TO EMPHASIZE ANY WINTRY WX TRAVEL CONCERNS
IN AN UPDATED SPS THIS MORNING.
LOCATIONS FURTHER EAST WILL ALSO SEE SOME SLEET OR PATCHY FREEZING
RAIN AT THE ONSET OF THE PRECIP...BUT TEMPS THROUGHOUT THE ENTIRE
THERMAL PROFILE WILL WARM OVER TIME...LEADING TO JUST A COLD RAIN BY
LATER THIS MORNING AND ESPECIALLY THIS AFTERNOON. THE HIGHEST PRECIP
RATES WILL BE ACROSS THE SRN HALF OF THE CWA WHERE TEMPS ARE
WARMEST. LIGHTER PRECIP RATES WILL BE SEEN ACROSS THE NRN
COUNTIES...WHERE TEMPS MAY REMAIN COLD ENOUGH THIS AFTERNOON TO SEE
SOME FREEZING RAIN MIX WITH THE RAIN...ESPECIALLY IN THE HIGHER
TERRAIN OF THE OZARKS AND NEAR THE MO BORDER. ONLY MINOR ICE
ACCUMULATIONS ARE EXPECTED THIS AFTERNOON IN AREAS WHERE THE
FREEZING RAIN OCCURS.
THIS EVENING...MOST LOCATIONS WILL SEE ALL RAINFALL AS TEMPS WILL
REMAIN STEADY OR EVEN WARM A DEG OR TWO BY FRI MORNING. MOST OF THE
PRECIP ACTIVITY WILL ALSO HAVE SHIFTED FURTHER SOUTH...WITH NRN
LOCATIONS LIKELY SEEING DRY CONDITIONS TONIGHT. AS A
RESULT...DROP POPS ALONG THE MO BORDER TO ONLY SLIGHT CHANCE. IF
ANY PRECIP WERE TO FALL ACROSS THE NRN COUNTIES...MAINLY RAIN IS
EXPECTED...THOUGH A FEW SPOTS IN THE HIGHER TERRAIN COULD AGAIN SEE
SOME FREEZING RAIN MIX IN WITH THE RAIN.
EVEN THIS CLOSE TO THE ONSET OF THIS MINOR WINTER WX EPISODE...THERE
DOES REMAIN SOME UNCERTAINTY REGARDING TEMPS. SOME ADJUSTMENTS IN
THE FORECAST REMAIN POSSIBLE...ESPECIALLY CONSIDERING SOME LOCATIONS
WILL BE SO NEAR THE FREEZING MARK. ANY CHANGES IN THE EXPECTED TEMPS
COULD ALTER THE POTENTIAL FROZEN PRECIP ACCUMULATION...RESULTING IN
INCREASED WINTER WX TRAVEL HAZARDS. PLEASE REFER TO THE LATEST
FORECASTS UPDATES THIS NEW YEARS DAY...ESPECIALLY IN THE HIGHER
TERRAIN OF THE OUACHITAS AND OZARKS...THE WRN COUNTIES...AND AREAS
ALONG THE MO BORDER.
ENOUGH WARMING WILL HAVE OCCURRED FOR FRI INTO SAT TO SEE ALL LIQUID
PRECIP. THE SW FLOW ALOFT WILL INTENSIFY FRI INTO SAT...WITH
WIDESPREAD SHRA AND EVEN SOME RUMBLES OF THUNDER POSSIBLE ACROSS THE
CWA. SOME LOCALLY HEAVY RAINFALL WILL ALSO BE POSSIBLE...THOUGH ONLY
WIDESPREAD RAINFALL AMOUNTS OF 1 TO 2 INCHES ARE CURRENTLY EXPECTED.
AS A RESULT...A FLASH FLOOD WATCH IS NOT EXPECTED AT THIS TIME.
THE STORM SYSTEM WILL EXIT THE REGION SAT INTO SAT NIGHT...WITH
DRIER AIR MOVING INTO THE STATE BY THE AFTERNOON HRS SAT. AS A
RESULT...HAVE POPS DECREASING RAPIDLY BY SAT AFTERNOON FROM SW TO
NE. SOME LINGERING MOISTURE COULD BE SEEN ACROSS THE NRN COUNTIES
SAT NIGHT...WITH SOME SPRINKLES OR A FEW SNOW FLAKES POSSIBLE.
A COLD FRONT WILL SURGE THROUGH THE STATE ON SUN...WITH COLDER AND
DRIER CONDITIONS MOVING INTO THE REGION. CHANCES FOR ANY PRECIP WILL
BE LOW TO END THE SHORT TERM PERIOD.
LONG TERM...MONDAY THROUGH WEDNESDAY
MODELS ARE IN DECENT AGREEMENT THIS MRNG WITH OVERALL FCST TRENDS
THRU THE PD. A WESTERLY FLOW ALOFT ON MON WL EVENTUALLY TURN NWLY
FOR TUE AND WED AS A LONG WV TROF SHARPENS OVR THE ERN HALF OF THE
NATION. AS A RESULT...A SERIES OF CLIPPER TYPE SFC LOWS WL DROP SEWD
AND BRING REINFORCING SHOTS OF COLDER AIR TO AR THRU THE MIDDLE OF
THE WEEK. WITH LTL IN THE WAY OF LOW LVL MOISTURE RETURN
ANTICIPATED...THE FCST WL RMN DRY.
&&
.PRELIMINARY POINT TEMPS/POPS...
BATESVILLE AR 37 34 40 36 / 50 40 80 80
CAMDEN AR 36 36 42 40 / 100 80 90 80
HARRISON AR 35 32 40 34 / 30 20 50 80
HOT SPRINGS AR 37 34 41 38 / 90 60 90 80
LITTLE ROCK AR 38 35 41 38 / 80 60 90 80
MONTICELLO AR 37 35 42 42 / 100 80 90 80
MOUNT IDA AR 38 34 41 37 / 90 60 90 80
MOUNTAIN HOME AR 34 33 41 35 / 30 20 50 80
NEWPORT AR 37 34 40 38 / 50 50 80 80
PINE BLUFF AR 37 35 41 40 / 90 80 90 80
RUSSELLVILLE AR 37 34 41 37 / 80 40 80 80
SEARCY AR 36 33 40 37 / 60 50 90 80
STUTTGART AR 37 34 41 39 / 90 60 90 80
&&
.LZK WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
65
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
320 PM MST THU JAN 1 2015
.SHORT TERM...(TONIGHT THROUGH FRIDAY NIGHT)
ISSUED AT 320 PM MST THU JAN 1 2015
THE HEAVIEST SNOWFALL OCCURRED LATE LAST NIGHT AND EARLY THIS
MORNING ACROSS THE FOUR CORNERS REGION AS PREDICTED. REPORTS
INDICATED 3 TO 5 INCHES OF SNOWFALL ACROSS MUCH OF THE REGION
WITH SNOWFALL RATES NEAR 1 INCH PER HOUR IN SOME LOCATIONS. UPWARD
FORCING IMPRESSIVE DURING THIS PERIOD AHEAD OF MID-LEVEL LOW
CENTERED OVER NORTH-CENTRAL ARIZONA. AT 12Z...GOOD SURFACE
CONVERGENCE IN EVIDENCE WITH SURFACE LOW CENTERED SOUTH OF KDRO
ACCORDING TO RAP ANALYSIS. CONCURRENTLY...STRONG MID-LEVEL QG
ASCENT OVER THE AREA TOPPED BY DIVERGENCE AT HIGHER LEVELS OF THE
TROPOSPHERE WHERE LEFT EXIT REGION OF JET WAS POSITIONED.
HOWEVER...DURING THE AFTERNOON COVERAGE AND SNOWFALL RATES HAD
DECREASED SIGNIFICANTLY AS FORCING WAS DIMINISHED. SOUTHWESTWARD
FLOWING JET ON THE BACK SIDE OF THE LOW CONTINUED TO PROPAGATE TO
THE SOUTHWEST WHILE THE NORTHEASTWARD FLOWING JET ON THE LEADING
EDGE MOVED OVER THE SOUTHERN PLAINS. THE SHEARING MOMENT BETWEEN
THESE FLOWS STRETCHED THE LOW ALONG A SOUTHWEST TO NORTHEAST AXIS.
AS A RESULT...DYNAMIC FORCING SHIFTED TO THE NORTHEAST CAUSING THE
SURFACE AND 7H LOW CIRCULATIONS TO MOVE IN THAT DIRECTION. IN
ADDITION TO THE LOSS OF DYNAMIC FORCING OVER THE SOUTHERN FORECAST
AREA...OROGRAPHIC LIFT ALSO IMPACTED AS WEAK 7H LOW RECENTERED
OVER THE SAN JUANS RESULTING IN WEAK AND VARIED WINDS.
MODELS IN GOOD AGREEMENT...GENERATING VERY LITTLE QPF OVER MOST OF
THE LOWER ELEVATIONS OF SOUTHEAST UTAH AND SOUTHWEST COLORADO
DURING THE REMAINDER OF THE AFTERNOON AND THIS EVENING. THEREFORE
...WILL CANCEL WINTER STORM WARNINGS FOR THESE AREAS WITH THIS
PACKAGE. HOWEVER...RAP13 AND HRRR BOTH INDICATED MODERATE SNOWFALL
WILL CONTINUE ALONG A SOUTHWEST TO NORTHEAST ORIENTED BAND
CENTERED OVER KCEZ. CONSEQUENTLY...WILL HOLD ONTO WINTER STORM
WARNING FOR MODERATE SNOWFALL OVER THE SOUTHWEST CORNER OF THE
STATE. IN ADDITION...LIGHT TO MODERATE SNOW SHOULD CONTINUE OVER
THE SAN JUAN MOUNTAINS WHILE COVERAGE INCREASES OVER THE CENTRAL
COLORADO MOUNTAINS AS DYNAMIC FORCING BECOMES MORE FAVORABLE. ONLY
EXPECTING 2 TO 4 INCHES WITH LOCALLY HIGHER AMOUNTS IN THE CENTRAL
MOUNTAINS SO WILL NOT EXPAND WINTER WEATHER ADVISORIES...THOUGH
WILL CONTINUE HILITES ACROSS THE SAN JUANS INTO THE EVENING.
SUBSIDENCE AND DRYING SETS IN LATER TONIGHT AS THE LOW CENTER IS
DRIVEN SOUTHWARD BY THE SOUTHWESTWARD PROPAGATING JET ON THE LOW/S
REAR FLANK. AS A RESULT...SNOWFALL WILL DIMINISH TO A FEW
FLURRIES OVER THE CENTRAL MOUNTAINS AFTER MIDNIGHT. ANTICYCLONIC
FLOW TO THE NORTH WILL INHIBIT SNOWFALL FRIDAY...THOUGH CANNOT
ENTIRELY RULE OUT A FEW FLURRIES ALONG THE DIVIDE FRIDAY
AFTERNOON. A SHORTWAVE TROUGH DROPPING TOWARD THE REGION FROM THE
NORTHWEST WILL BE THE NEXT SNOW PRODUCER OVER THE FORECAST AREA
POSSIBLY IMPACTING THE NORTHERN COLORADO MOUNTAINS FRIDAY NIGHT.
THE AREA WILL BE UNDER WARM AIR ADVECTION WHILE FLOW REMAINS
ANTICYCLONIC SO EXPECT SNOW WILL BE SCATTERED AND LIGHT...LIKELY
HOLDING OFF UNTIL AFTER MIDNIGHT AS INDICATED BY FAVORED GFS AND
ECMWF SOLUTIONS.
WAA WILL ALLOW AIRMASS TO MODERATE A BIT...BUT TEMPERATURES WILL
REMAIN COLDER THAN NORMAL FOR THE LATTER PART OF THE WEEK.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 320 PM MST THU JAN 1 2015
EXPECT SNOW WILL INCREASE OVER THE NORTHERN COLORADO MOUNTAINS
SATURDAY AS THE SHORTWAVE TROUGH DISCUSSED PREVIOUSLY PUSHES
ACROSS SOUTHWEST WYOMING IN THE MORNING...THEN ACROSS NORTHWEST
COLORADO DURING THE AFTERNOON. MODELS NOT GENERATING SIGNIFICANT
SNOW ACCUMULATIONS AT THIS POINT...BUT THERE REMAINS THE POTENTIAL
FOR ADVISORY LEVEL SNOW ACROSS THE PARK...GORE...ELKHEAD...AND
FLATTOP RANGES. A TIGHTENING GRADIENT ALOFT BENEATH THE NOSE OF A
SOUTHWARD FLOWING 120 KT JET WILL GENERATE STRONG AND GUSTY
NORTHWEST WINDS ACROSS THE RIDGES GENERATING AREAS OF BLOWING
SNOW.
MODELS INDICATED ANOTHER SHORTWAVE IN THE NORTHWESTERLIES WILL
BRING SIMILAR CONDITIONS SUNDAY AFTERNOON THROUGH SUNDAY NIGHT...
THOUGH IT APPEARS TO BE WEAKER THAN SATURDAY/S SYSTEM. HOWEVER...
ECMWF INDICATED THAT OROGRAPHIC SNOWFALL COULD CONTINUE WELL INTO
MONDAY SO MAY BE MORE IMPACTFUL THAN DEPICTED NOW. A RIDGE OF HIGH
PRESSURE EASES EASTWARD FROM TUESDAY TO THURSDAY BRINGING DRY AND
MILDER CONDITIONS FOR THE MIDDLE PART OF THE COMING WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 320 PM MST THU JAN 1 2015
WITH THE STORM CIRCULATION CENTER MOVING THROUGH NORTH-CENTRAL
THEN NORTHEAST NEW MEXICO TONIGHT AND THE JET RUNNING FURTHER
SOUTH AND EAST...MOST OF THE PRECIPITATION HAS SHIFTED TO THE
NORTHERN HEMISPHERE OF THE STORM. THE BEST ENHANCEMENT WILL BE
NORTH AND WEST OF A DISTURBANCE CIRCULATING OVER KCOS.
PRECIPITATION ENHANCED BY THAT DISTURBANCE WILL MOVE OVER KASE
THROUGH EARLY THIS EVENING...PROVIDING THE FURTHER DEGRADATION OF
FLIGHT CONDITIONS THERE. EXPECT MVFR CIGS AND VSBYS OVER KASE
UNTIL ABOUT 06Z AND INTERMITTENT IFR IN STRONGER SNOW SHOWERS
THROUGH ABOUT 02Z. KEGE...KRIL SHOULD SEE BRIEF MVFR CIGS AND
VSBYS THRU ABOUT 04Z AS SNOW SHOWERS ROTATE OVER THOSE LOCATIONS.
KGJT...KVEL AND ALL AIRPORTS NORTH OF I-70 SHOULD REMAIN VFR.
THE NORTHERN EDGE OF THE MAIN PRECIP BAND WILL EXTEND FROM KFNL
THEN SOUTHWEST TO KCNY. THE HEAVIEST PRECIP IN THE BAND SHOULD
EXTEND FROM KASE TO KMTJ TO ABOUT KBDG. MOUNTAINS AND HIGH PASSES
ACROSS CENTRAL CO AND SE UT WILL REMAIN OBSCURED TONIGHT AND BEGIN
OPENING UP AFTER SUNRISE. CONDITIONS WILL IMPROVE SIGNIFICANTLY
AFTER ABOUT 08Z TONIGHT.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER WEATHER ADVISORY UNTIL MIDNIGHT MST TONIGHT FOR COZ018.
WINTER STORM WARNING UNTIL 6 PM MST THIS EVENING FOR COZ021.
WINTER STORM WARNING UNTIL MIDNIGHT MST TONIGHT FOR COZ019.
UT...WINTER STORM WARNING UNTIL MIDNIGHT MST TONIGHT FOR UTZ028.
&&
$$
SHORT TERM...NL
LONG TERM...NL
AVIATION...CC
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1254 PM MST THU JAN 1 2015
.UPDATE...
ISSUED AT 1254 PM MST THU JAN 1 2015
BAND OF SNOW MOVING ACROSS THE PALMER DIVIDE IS PRODUCING A PERIOD
OF HEAVY SNOW. IT IS ALSO MAKING A FASTER NORTHWARD PROGRESSION.
AS A RESULT OF THE HEAVIER INTENSITY..SHOULD HAVE A BETTER CHANCE
OF MAKING IT INTO THE DENVER METRO AREA THIS AFTERNOON SO HAVE
BOOSTED POPS ACCORDINGLY.
UPDATE ISSUED AT 1012 AM MST THU JAN 1 2015
SATELLITE SHOWS THE MID LEVEL CLOUD DECK SPREADING INTO THE
SOUTHERN PORTIONS OF THE FORECAST AREA. RADAR ECHOES ARE RAPIDLY
INCREASING IN COVERAGE JUST TO THE SOUTH OF THE FORECAST
AREA IN SOUTHERN COLORADO...BUT MOST OF THIS IS VIRGA ON THE
PLAINS. MEANWHILE...MOUNTAIN LOCALES IN SOUTHERN COLORADO
ARE RECEIVING ACCUMULATING SNOWFALL. Q-G LIFT WILL INCREASE
THROUGH THE AFTERNOON UNDER THE LARGE SCALE DEFORMATION ZONE
SETTING UP ACROSS OUR FORECAST AREA. AS A RESULT...THE CLOUDS
WILL CONTINUE TO THICKEN AND LOWER WITH VIRGA BECOMING WIDESPREAD.
QUESTION STILL SURROUNDS HOW EFFICIENTLY THE SUBCLOUD LAYER WILL
MOISTEN ESPECIALLY SINCE THERE IS STILL SOME LOW LEVEL DOWNSLOPE
COMPONENT BELOW 700 MB. ABOVE THAT...FAIRLY STRONG EASTERLY
UPSLOPE COMPONENT AROUND 20 KNOTS ON AVERAGE. DUE TO THE DRIER LOW
LEVEL AIR...THE MAIN THREAT OF ACCUMULATING SNOW STILL RESIDES
FROM PARK/SUMMIT COUNTIES EASTWARD INTO DOUGLAS COUNTY AND THE
PALMER DIVIDE AREA LATER THIS AFTERNOON. HOWEVER...BY LATER THIS
EVENING THE BEST LIFT SHIFTS SLOWLY NORTHWARD SO BETTER CHANCE
COULD ACTUALLY MOVE SOMEWHAT NORTH. WILL HAVE TO WATCH THIS FOR
DUSTING TO 1 INCH OF SNOW POSSIBLE OVER THE DENVER METRO AREA
MAINLY BETWEEN 4 PM AND MIDNIGHT. ALL OF THIS HANDLED WELL IN
EXISTING FORECAST SO ONLY ADJUSTMENTS WERE TO INCREASE PARK COUNTY
POPS AS EVEN VALLEY LOCATIONS IN SOUTH PARK SHOULD PICK UP
MEASURABLE SNOWFALL THIS AFTERNOON.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 425 AM MST THU JAN 1 2015
A CLOSED MID-UPPER LOW OVER NORTH CENTRAL ARIZONA AT 09Z
WILL BECOME INCREASINGLY ELONGATED ACROSS COLORADO AS IT SHIFTS
EASTWARD ACROSS THE FOUR CORNERS REGION TODAY. AT THE SFC...AN
EXPANSIVE AREA OF HIGH PRESSURE LINKED TO AN ARCTIC AIRMASS COVERS
THE GREAT PLAINS. MODELS SHOW PRECIP FORMING NORTHEASTWARD ALONG THE
700-500MB TROUGH DEFORMATION AXIS REACHING THE SOUTHWEST CORNER OF
THE FORECAST AREA BY LATE THIS MORNING. FORWARD SPEED OF CLOUD
SHIELD WRAPPING AROUND THE UPPER LOW WILL LIKELY ARRIVE SOONER THAN
THAT BASED ON SPEED OF MOTION MEASUREMENTS USING IR SATELLITE
IMAGERY. EXCEPT FOR A BAND OF CIRRUS CLOUD STREAKING NEWRD ACRS THE
SOUTHEAST CORNER OF THE CWA...SKIES AT THE PRESENT TIME WERE CLEAR
ACROSS N-CENTRAL/NORTHEAST COLORADO. HRRR AND RAP MDLS SHOW LIGHT
SNOWFALL/QPF OVER THE MOSQUITO...TEN MILE AND SOUTHERN FRONT RANGE
MTNS BY MIDDAY...THEN SPREADING NORTHWARD OVER THE FRONT RANGE AND
EASTWARD ALONG THE PALMER DIVIDE AND SOUTHERN SECTIONS OF THE I-25
URBAN CORRIDOR DURING THE LATE AFTERNOON HOURS. FORECASTED PCPN AMTS
IN THIS AREA RANGE FROM A TRACE TO 0.20 INCH BY 00Z/FRI...AND SNOW
AMOUNTS FROM A TRACE TO 3 INCHES. THE HEAVIER AMTS WILL BE FOUND
OVER THE HIGHER TERRAIN SURROUNDING SOUTH PARK AND ALONG HIGHER
PORTIONS OF THE PALMER DIVIDE IN DOUGLAS COUNTY. BY EVENING WITH THE
UPPER LOW WEAKENING AND TURNING SOUTHEAST AWAY FROM COLORADO...
SHOULD SEE A MARKED DECREASE IN SNOWFALL ACROSS SOUTHERN SECTIONS OF
THE CWA BY MID TO LATE EVENING. AS THIS IS TAKING PLACE...MODELS
NAMELY THE NAM...SHOW A SECONDARY AREA OF SNOWFALL DEVELOPING OVER
THE NORTHERN FRONT RANGE MTN AND NRN I-25 URBAN CORRIDOR AS A RESULT
OF OROGRAPHIC LIFT AND COLD ADVECTION OCCURRING ON THE NORTHERN
FRINGE OF THE UPPER TROUGH. COULD SEE LOCAL SNOW AMTS UP TO AN INCH
OR SO OVER HIGHER ELEVATIONS OF THE NRN FRONT RANGE AND POSSIBLY A
QUARTER INCH OR SO ON THE NEARBY PLAINS BEFORE SKIES CLEAR AROUND
10Z/FRI.
HIGH TEMPERATURES TODAY ARE EXPECTED TO BE A FEW DEGS COOLER THAN
YESTERDAY DUE IN LARGE PART TO THE LACK OF SUNSHINE THIS AFTERNOON.
WHEREAS TEMPS TONIGHT NOT AS COLD AS PREVIOUS NIGHTS BECAUSE OF
CLOUD COVER AND AS A RESULT OF MIXED BNDRY LAYER DUE TO PCPN IN
THE AREA.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 425 AM MST THU JAN 1 2015
THE UPPER LOW NOW OVER ARIZONA WILL WEAKEN AND BECOME ELONGATED
ACROSS COLORADO EARLY FRIDAY MORNING. A PIECE OF THIS LOW
SEPARATES FROM THE PARENT SYSTEM WHICH WILL REMAIN OVER NEW
MEXICO THROUGH FRIDAY NIGHT. STILL EXPECT A FAIR AMOUNT OF
CLOUDINESS FRIDAY AM BUT ANY PRECIP WILL HAVE FINISHED DURING THE
EARLY MORNING HOURS. TEMPERATURES WILL STILL REMAIN IN THE 30S
ACROSS LOWER ELEVATIONS.
THE MAIN LOW OVER NEW MEXICO IS PROGGED TO LIFT NORTHEAST INTO THE
CENTRAL PLAINS ON SATURDAY WHILE A SECONDARY WAVE MOVES RAPIDLY
SOUTHEAST FROM THE NORTHERN ROCKIES. AN ACCOMPANIED COLD FRONT
EXPECTED TO BLAST ACROSS THE NORTHEAST PLAINS AROUND MIDDAY
SATURDAY WITH A BRIEF PERIOD OF UPSLOPE FLOW ON SATURDAY AFTERNOON
AND QUICK SHOT OF QG UPWARD FORCING AS STRONG JET MOVES ACROSS
COLORADO. WILL CONTINUE TO INCREASE POPS SLIGHTLY DURING THIS
PERIOD AS CONDITIONS CONTINUE TO LOOK MORE FAVORABLE FOR A SHOT OF
SNOW OVER MOUNTAINS AND PLAINS.
FOR SUNDAY AND INTO EARLY NEXT WEEK....THE PATTERN WILL SHIFT TO
A STRONG NORTHWEST FLOW ALOFT. THIS WILL RESULT IN INCREASING
WINDS OVER MOUNTAINS AND EAST SLOPES WITH A DOWNSLOPE WARMING
TREND OVER THE NORTHEAST PLAINS. GIVEN THE FLOW PATTERN EXPECT
SOME SNOW SHOWERS TO CONTINUE OVER THE HIGHER ELEVATIONS OF THE
NORTHERN MOUNTAINS BUT ONLY MINIMAL ACCUMULATIONS.
&&
.AVIATION...(FOR THE TAFS THROUGH 18Z FRIDAY MORNING)
ISSUED AT 1254 PM MST THU JAN 1 2015
CLOUDS WILL CONTINUE TO THICKEN AND LOWER THROUGH 21Z-03Z WITH
ILS LANDING CONDITIONS LIKELY WITH CEILINGS UNDER 5000-6000 FEET.
SHOULD ALSO SEE AREAS OF MVFR CEILINGS AND 3-4SM VISIBILITIES IN
LIGHT SNOW 21Z-07Z. LOCAL VISIBILITY AROUND 1SM WITH AROUND 1 INCH
ACCUMULATION POSSIBLE AT KAPA GIVEN INTENSITY OF SNOW BAND
MOVING UP FROM THE SOUTH. AFT 07Z...AREAS OF LIGHT SNOW AND LOWER
CEILINGS ARE EXPECTED TO DISSIPATE THRU 12Z AS AIRMASS GRADUALLY
DRIES AND UPPER LEVEL DISTURBANCE DEPARTS TO THE NORTHEAST. LIGHT
SOUTH/SOUTHWEST WINDS UNDER 7 KNOTS MAY BECOME LIGHT/VARIABLE
THROUGH THE EARLY EVENING BEFORE SETTLING TO A SOUTHWEST/WEST
AROUND 5-8 KNOTS OVERNIGHT.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BARJENBRUCH
SHORT TERM...BAKER
LONG TERM...ENTREKIN
AVIATION...BARJENBRUCH
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1012 AM MST THU JAN 1 2015
.UPDATE...
ISSUED AT 1012 AM MST THU JAN 1 2015
SATELLITE SHOWS THE MID LEVEL CLOUD DECK SPREADING INTO THE
SOUTHERN PORTIONS OF THE FORECAST AREA. RADAR ECHOES ARE RAPIDLY
INCREASING IN COVERAGE JUST TO THE SOUTH OF THE FORECAST
AREA IN SOUTHERN COLORADO...BUT MOST OF THIS IS VIRGA ON THE
PLAINS. MEANWHILE...MOUNTAIN LOCALES IN SOUTHERN COLORADO
ARE RECEIVING ACCUMULATING SNOWFALL. Q-G LIFT WILL INCREASE
THROUGH THE AFTERNOON UNDER THE LARGE SCALE DEFORMATION ZONE
SETTING UP ACROSS OUR FORECAST AREA. AS A RESULT...THE CLOUDS
WILL CONTINUE TO THICKEN AND LOWER WITH VIRGA BECOMING WIDESPREAD.
QUESTION STILL SURROUNDS HOW EFFICIENTLY THE SUBCLOUD LAYER WILL
MOISTEN ESPECIALLY SINCE THERE IS STILL SOME LOW LEVEL DOWNSLOPE
COMPONENT BELOW 700 MB. ABOVE THAT...FAIRLY STRONG EASTERLY
UPSLOPE COMPONENT AROUND 20 KNOTS ON AVERAGE. DUE TO THE DRIER LOW
LEVEL AIR...THE MAIN THREAT OF ACCUMULATING SNOW STILL RESIDES
FROM PARK/SUMMIT COUNTIES EASTWARD INTO DOUGLAS COUNTY AND THE
PALMER DIVIDE AREA LATER THIS AFTERNOON. HOWEVER...BY LATER THIS
EVENING THE BEST LIFT SHIFTS SLOWLY NORTHWARD SO BETTER CHANCE
COULD ACTUALLY MOVE SOMEWHAT NORTH. WILL HAVE TO WATCH THIS FOR
DUSTING TO 1 INCH OF SNOW POSSIBLE OVER THE DENVER METRO AREA
MAINLY BETWEEN 4 PM AND MIDNIGHT. ALL OF THIS HANDLED WELL IN
EXISTING FORECAST SO ONLY ADJUSTMENTS WERE TO INCREASE PARK COUNTY
POPS AS EVEN VALLEY LOCATIONS IN SOUTH PARK SHOULD PICK UP
MEASURABLE SNOWFALL THIS AFTERNOON.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 425 AM MST THU JAN 1 2015
A CLOSED MID-UPPER LOW OVER NORTH CENTRAL ARIZONA AT 09Z
WILL BECOME INCREASINGLY ELONGATED ACROSS COLORADO AS IT SHIFTS
EASTWARD ACROSS THE FOUR CORNERS REGION TODAY. AT THE SFC...AN
EXPANSIVE AREA OF HIGH PRESSURE LINKED TO AN ARCTIC AIRMASS COVERS
THE GREAT PLAINS. MODELS SHOW PRECIP FORMING NORTHEASTWARD ALONG THE
700-500MB TROUGH DEFORMATION AXIS REACHING THE SOUTHWEST CORNER OF
THE FORECAST AREA BY LATE THIS MORNING. FORWARD SPEED OF CLOUD
SHIELD WRAPPING AROUND THE UPPER LOW WILL LIKELY ARRIVE SOONER THAN
THAT BASED ON SPEED OF MOTION MEASUREMENTS USING IR SATELLITE
IMAGERY. EXCEPT FOR A BAND OF CIRRUS CLOUD STREAKING NEWRD ACRS THE
SOUTHEAST CORNER OF THE CWA...SKIES AT THE PRESENT TIME WERE CLEAR
ACROSS N-CENTRAL/NORTHEAST COLORADO. HRRR AND RAP MDLS SHOW LIGHT
SNOWFALL/QPF OVER THE MOSQUITO...TEN MILE AND SOUTHERN FRONT RANGE
MTNS BY MIDDAY...THEN SPREADING NORTHWARD OVER THE FRONT RANGE AND
EASTWARD ALONG THE PALMER DIVIDE AND SOUTHERN SECTIONS OF THE I-25
URBAN CORRIDOR DURING THE LATE AFTERNOON HOURS. FORECASTED PCPN AMTS
IN THIS AREA RANGE FROM A TRACE TO 0.20 INCH BY 00Z/FRI...AND SNOW
AMOUNTS FROM A TRACE TO 3 INCHES. THE HEAVIER AMTS WILL BE FOUND
OVER THE HIGHER TERRAIN SURROUNDING SOUTH PARK AND ALONG HIGHER
PORTIONS OF THE PALMER DIVIDE IN DOUGLAS COUNTY. BY EVENING WITH THE
UPPER LOW WEAKENING AND TURNING SOUTHEAST AWAY FROM COLORADO...
SHOULD SEE A MARKED DECREASE IN SNOWFALL ACROSS SOUTHERN SECTIONS OF
THE CWA BY MID TO LATE EVENING. AS THIS IS TAKING PLACE...MODELS
NAMELY THE NAM...SHOW A SECONDARY AREA OF SNOWFALL DEVELOPING OVER
THE NORTHERN FRONT RANGE MTN AND NRN I-25 URBAN CORRIDOR AS A RESULT
OF OROGRAPHIC LIFT AND COLD ADVECTION OCCURRING ON THE NORTHERN
FRINGE OF THE UPPER TROUGH. COULD SEE LOCAL SNOW AMTS UP TO AN INCH
OR SO OVER HIGHER ELEVATIONS OF THE NRN FRONT RANGE AND POSSIBLY A
QUARTER INCH OR SO ON THE NEARBY PLAINS BEFORE SKIES CLEAR AROUND
10Z/FRI.
HIGH TEMPERATURES TODAY ARE EXPECTED TO BE A FEW DEGS COOLER THAN
YESTERDAY DUE IN LARGE PART TO THE LACK OF SUNSHINE THIS AFTERNOON.
WHEREAS TEMPS TONIGHT NOT AS COLD AS PREVIOUS NIGHTS BECAUSE OF
CLOUD COVER AND AS A RESULT OF MIXED BNDRY LAYER DUE TO PCPN IN
THE AREA.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 425 AM MST THU JAN 1 2015
THE UPPER LOW NOW OVER ARIZONA WILL WEAKEN AND BECOME ELONGATED
ACROSS COLORADO EARLY FRIDAY MORNING. A PIECE OF THIS LOW
SEPARATES FROM THE PARENT SYSTEM WHICH WILL REMAIN OVER NEW
MEXICO THROUGH FRIDAY NIGHT. STILL EXPECT A FAIR AMOUNT OF
CLOUDINESS FRIDAY AM BUT ANY PRECIP WILL HAVE FINISHED DURING THE
EARLY MORNING HOURS. TEMPERATURES WILL STILL REMAIN IN THE 30S
ACROSS LOWER ELEVATIONS.
THE MAIN LOW OVER NEW MEXICO IS PROGGED TO LIFT NORTHEAST INTO THE
CENTRAL PLAINS ON SATURDAY WHILE A SECONDARY WAVE MOVES RAPIDLY
SOUTHEAST FROM THE NORTHERN ROCKIES. AN ACCOMPANIED COLD FRONT
EXPECTED TO BLAST ACROSS THE NORTHEAST PLAINS AROUND MIDDAY
SATURDAY WITH A BRIEF PERIOD OF UPSLOPE FLOW ON SATURDAY AFTERNOON
AND QUICK SHOT OF QG UPWARD FORCING AS STRONG JET MOVES ACROSS
COLORADO. WILL CONTINUE TO INCREASE POPS SLIGHTLY DURING THIS
PERIOD AS CONDITIONS CONTINUE TO LOOK MORE FAVORABLE FOR A SHOT OF
SNOW OVER MOUNTAINS AND PLAINS.
FOR SUNDAY AND INTO EARLY NEXT WEEK....THE PATTERN WILL SHIFT TO
A STRONG NORTHWEST FLOW ALOFT. THIS WILL RESULT IN INCREASING
WINDS OVER MOUNTAINS AND EAST SLOPES WITH A DOWNSLOPE WARMING
TREND OVER THE NORTHEAST PLAINS. GIVEN THE FLOW PATTERN EXPECT
SOME SNOW SHOWERS TO CONTINUE OVER THE HIGHER ELEVATIONS OF THE
NORTHERN MOUNTAINS BUT ONLY MINIMAL ACCUMULATIONS.
&&
.AVIATION...(FOR THE TAFS THROUGH 18Z FRIDAY MORNING)
ISSUED AT 1012 AM MST THU JAN 1 2015
CLOUDS WILL CONTINUE TO THICKEN AND LOWER THROUGH 22Z-03Z WITH
ILS LANDING CONDITIONS LIKELY WITH CEILINGS UNDER 5000-6000 FEET.
SHOULD ALSO SEE POCKETS OF MVFR CEILINGS AND 3-4SM VISIBILITIES IN
LIGHT SNOW 22Z-07Z. AFT 07Z...AREAS OF LIGHT SNOW AND LOWER
CEILINGS ARE EXPECTED TO DISSIPATE THRU 12Z AS AIRMASS GRADUALLY
DRIES AND UPPER LEVEL DISTURBANCE DEPARTS TO THE NORTHEAST. LIGHT
SOUTH/SOUTHWEST WINDS UNDER 7 KNOTS MAY BECOME LIGHT/VARIABLE
THROUGH THE EARLY EVENING BEFORE SETTLING TO A SOUTHWEST/WEST
AROUND 5-8 KNOTS OVERNIGHT.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BARJENBRUCH
SHORT TERM...BAKER
LONG TERM...ENTREKIN
AVIATION...BARJENBRUCH
AREA FORECAST DISCUSSION
NWS MIAMI FL
124 PM EST THU JAN 1 2015
.AVIATION...
LINGERING STATIONARY FRONT ACROSS THE AREA IS EXPECTED TO PUSH TO
THE NORTH AS A WARM FRONT THROUGH THE NIGHT. THIS WILL LEAVE AMPLE
LOW LEVEL MOISTURE AND THE THREAT OF FOG/LOW CIGS MAINLY ACROSS
THE GULF COAST OVERNIGHT AND INTO EARLY FRIDAY MORNING. UNDERCUT
LAMP GUIDANCE AGAIN FOR KAPF THROUGH THE NIGHT PREVAILING MVFR
CIGS WITH TEMPO IFR CIGS AND VSBY. BELIEVE THAT THE EAST COAST
SITES SHOULD REMAIN VFR WITH BRIEF MVFR CIGS POSSIBLE BUT NOT
CONFIDENT ENOUGH TO MENTION IN TAFS ATTM.
&&
.PREV DISCUSSION... /ISSUED 1004 AM EST THU JAN 1 2015/
UPDATE...
SCATTERED SHOWERS REMAIN THIS MORNING MAINLY ACROSS THE ATLANTIC
WATERS OFF THE PALM BEACHES. WEAK STATIONARY FRONT REMAINS DRAPED
ACROSS THE AREA THIS MORNING CONTRIBUTING TO THE SHOWERS AND
EXTENSIVE CLOUDINESS. LATEST VISIBLE SATELLITE DOES HOWEVER SHOW
CLOUD SHIELD BEGINNING TO ERODE ACROSS BROWARD AND MIAMI-DADE
COUNTIES LATE THIS MORNING. THIS HAS ALLOWED TEMPERATURES TO SURGE
INTO THE MID TO UPPER 70S ALREADY. HRRR CONTINUES TO DEPICT
ISOLATED LIGHT SHOWERS ACROSS MAINLY THE EASTERN HALF OF THE AREA
INTO THE EARLY AFTERNOON HOURS...SO KEPT SLIGHT CHANCE POP GOING.
THE REMAINDER OF THE FORECAST LOOKS ON TRACK AT THIS TIME. UPDATE
SENT.
PREV DISCUSSION... /ISSUED 319 AM EST THU JAN 1 2015/
DISCUSSION...
A COMPACT AND WEAK MESOSCALE LOW PASSED SOUTHWARD ACROSS THE
ATLANTIC WATERS YESTERDAY ALONG PALM BEACH COUNTY THEN DRIFTED
WESTWARD ACROSS THE SOUTH FLORIDA PENINSULA EARLY THIS MORNING.
DURING THE EARLY MORNING HOURS SCATTERED SHOWER ACTIVITY OCCURRED
WITH THE GREATEST COVERAGE ACROSS NORTHERN BROWARD COUNTY AND
ACROSS PALM BEACH COUNTY AND ADJACENT ATLANTIC WATERS...WITH THIS
COVERAGE CONTINUING.
THE COMBINATION OF LOW STRATUS AND/OR FOG WILL CONTINUE EARLY THIS
MORNING WITH MOST OF THE COVERAGE EXPECTED ACROSS MIAMI DADE
COUNTY AND SOUTHERN HALF OF BROWARD COUNTY.
THE WILL BE A CHANCE OF RIP CURRENTS TODAY BUT MAINLY EXPECTED
ACROSS THE PALM BEACH COUNTY BEACHES.
THE LATEST MODEL GUIDANCE INDICATES A WEAK SURFACE TROUGH AND
DIFFUSE FRONTAL BOUNDARY CONTINUING ACROSS THE SOUTH FLORIDA
PENINSULA TODAY WITH HIGH PRESSURE THEN STARTING TO BUILD BACK
ACROSS THE REGION THIS EVENING AND OVER NIGHT. THE FORECAST FOR
TODAY IS FOR ISOLATED TO SCATTERED SHOWERS MAINLY ACROSS THE
ATLANTIC WATERS AND THE ATLANTIC METRO AREAS WITH THE GREATEST
COVERAGE CONTINUING TO BE ACROSS BROWARD AND PALM BEACH COUNTIES
AND THE ADJACENT ATLANTIC WATERS. A DRYING TREND IS THEN FORECAST
WITH THE MODEL CONSENSUS INDICATING SOUTHERLY LOW LEVEL FLOW
BRINGING IN DRIER AIR INTO THE REGION TONIGHT INTO FRIDAY. BY
FRIDAY HIGH PRESSURE WILL PREVAIL ACROSS THE REGION WITH A SURFACE
RIDGE EAST OF THE FLORIDA PENINSULA AND AT THE MID TO UPPER LEVELS
A LARGE AMPLITUDE RIDGE BECOMING ESTABLISHED ACROSS THE FLORIDA
STRAITS. THIS PATTERN WILL MORE OR LESS PERSIST THROUGH THE
UPCOMING WEEKEND...WITH STABLE WEATHER CONDITIONS AND INCREASINGLY
WARMER TEMPERATURES PREVAILING ACROSS THE REGION.
FOR THE EXTENDED FORECAST...THE GLOBAL MODEL CONSENSUS INDICATES
THE NEXT COLD FRONT ENTERING THE FLORIDA PANHANDLE AND NORTHERN
FLORIDA ON SUNDAY AND THEN INTO CENTRAL FLORIDA ON MONDAY AND APPROACHING
LAKE OKEECHOBEE AND WEAKENING MONDAY NIGHT. BY TUESDAY THE MODELS
START TO DIVERGE IN THEIR SOLUTIONS...BUT OVER ALL NO SIGNIFICANT
IMPACTS ARE FORECAST THUS FAR FOR SOUTH FLORIDA WITH THE FORECAST
INDICATING JUST A GRADUAL COOL DOWN AND POSSIBLY SOME ISOLATED
SHOWER ACTIVITY. /BD
MARINE...
THE LOCAL PRESSURE GRADIENT ACROSS THE REGION EARLY THIS MORNING
IS SUCH THAT WINDS IN THE 15 TO 20 KNOT RANGE ARE FORECAST ACROSS
THE ATLANTIC WATERS MAINLY TO THE EAST OF PALM BEACH COUNTY AND
ACROSS THE OFF SHORE WATERS...WITH AN SCEC FOR THESE WATERS TODAY.
THE PRESSURE GRADIENT AND RESULTANT WINDS EAST OF PALM BEACH
COUNTY IS FORECAST TO RELAX TONIGHT INTO FRIDAY. FOR THE REMAINDER
OF THE OF THE FORECAST...WINDS AND SEAS ACROSS THE GULF AND
ATLANTIC WATERS ARE FORECAST TO REMAIN WELL BELOW ADVISORY LEVELS.
/BD
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 70 81 73 82 / 10 10 10 10
FORT LAUDERDALE 72 81 73 81 / 10 10 10 10
MIAMI 71 81 73 83 / 10 10 10 10
NAPLES 67 81 68 82 / 10 10 10 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...60/BD
LONG TERM....60/BD
AVIATION...10/CD
AREA FORECAST DISCUSSION
NWS POCATELLO ID
201 PM MST THU JAN 1 2015
.SHORT TERM...TONIGHT THROUGH SUNDAY. THE LATEST SATELLITE IMAGERY
WAS CLEARLY SHOWING A BROAD AREA OF STRATUS/LOW CLOUDS EXTENDING
FROM BOISE UP THE VALLEY THROUGH POCATELLO. NUMERICAL MODELS SHOW
THE STRATUS WORKING FURTHER NE TONIGHT AND LINGERING THROUGH A GOOD
PORTION OF THE MORNING FRIDAY BEFORE GRADUALLY DISSIPATING AHEAD OF
AN INCOMING SYSTEM. FURTHER UPSTREAM...A VIGOROUS PAC STORM SYSTEM
WAS SPREADING INTO THE NW BRITISH COLUMBIA COAST. THE MODELS SHEAR
THIS WAVE SE ACROSS THE CANADIAN ROCKIES TONIGHT/FRIDAY AND ALONG
THE MONTANA/WYOMING DIVIDE FRIDAY NIGHT/SATURDAY WITH ATTENDING
SNOWFALL IMPACTING MAINLY THE NE MOUNTAINS. STORM TOTAL
ACCUMULATIONS OF 1 TO 4 INCHES ARE ANTICIPATED FRIDAY NIGHT/SATURDAY
IN THE MOUNTAINS FROM ISLAND PARK SOUTH THROUGH SODA SPRINGS. SOME
EROSION OF THE COLD AIR TRAPPED IN THE VALLEYS IS ALSO ANTICIPATED
LATE FRIDAY AFTERNOON/SATURDAY. A SECOND STRONGER SYSTEM HITS THE NW
BRITISH COLUMBIA COAST SUNDAY WHILE THE ASSOCIATED PRECIPITATION
BEGINS TO SPREAD INTO THE NRN AND ERN MOUNTAINS AS EARLY AS SATURDAY
NIGHT AND CONTINUES THROUGH SUNDAY AND MONDAY. CONTINUED WARMING IS
EXPECTED SUNDAY AS SW WINDS BEGIN TO SCOUR OUT THE REMAINING COLD
AIR TRAPPED IN THE VALLEYS. HUSTON
.LONG TERM...SUNDAY NIGHT THROUGH NEXT THURSDAY NIGHT. ONLY ONE
SIGNIFICANT TROUGH PASSING THROUGH EARLY DURING THE EXTENDED PERIOD.
EXPECTED TO MAINLY AFFECT THE MOUNTAINS WITH A MODERATE AMOUNT OF
SNOW...WHILE THE LOWER ELEVATIONS WILL SEE EITHER RAIN OR SNOW WITH
ONLY LIGHT ACCUMULATION. THIS WILL MAINLY BE SUN NIGHT AND MON.
AFTER THIS...AN UPPER LEVEL HIGH MOVES IN FROM THE SOUTH...KEEPING
MILD AIR AND LOWER ELEVATION TEMPERATURES IN AT LEAST THE UPPER 30S.
AT THE VERY END...CLOUDS START TO OVERSPREAD AGAIN FROM THE WEST AS
ANOTHER LOW ENTERS THE NORTH AMERICAN WEST COAST. GFS IS TENDING TO
BE THE DRIER GUIDANCE COMPARED TO ECMWF. THE ECMWF IS ALSO MUCH
WARMER WITH HIGHER 500MB HEIGHTS AND THUS WARMER AIRMASS. HAVE SIDED
A LITTLE MORE TOWARDS THE GFS...ESPECIALLY FOR OVERNIGHT LOWS.
MESSICK
&&
.AVIATION...STRATUS AND FOG COULD...AND SHOULD...BE A PROBLEM AGAIN
TONIGHT. BUT IT IS A LOW CONFIDENCE FORECAST BASED ON SEVERAL
ISSUES. THE PRESSURE GRADIENT ACROSS THE EASTERN MAGIC VALLEY AND
SNAKE RIVER PLAIN WILL INFLUENCE WIND TO BE WESTERLY...WHILE THE
NATURAL SLOPE-VALLEY EFFECT WOULD BE THE OPPOSITE. THE SPREAD OF
STRATUS BACK OVER THE THREE VALLEY AIRDROMES IS COMPLETELY DEPENDENT
ON THE WIND FLOW. HRRR FORECAST INDICATES NORTHEAST TO EAST GRADIENT
DEVELOPS AND KEEPS THE STRATUS AWAY FROM THE LOW ELEVATION AIRPORTS.
BOUNDARY LAYER MOISTURE PROGS AND STATISTICS INDICATE THE STRATUS
SHOULD RECUR...PLUS THE STRATUS HAS IN NO WAY TOTALLY EVAPORATED.
THUS HAVE HAD IT REDEVELOP AND BE EVEN LOWER THAN IT WAS LAST NIGHT.
MEANWHILE...AT KSUN THE STRATUS DID ADVECT UP THE VALLEY WITH THE
ONSET OF SOUTHEAST WIND...BUT IT PULLED UP SHORT AND THINNED WITH
THE DIURNAL WARMING. FEEL MORE CONFIDENT ABOUT THIS ONE THAT THE FOG
WILL STAY AWAY AT LEAST THROUGH THE LATE NIGHT AND MORNING HOURS OF
THE TAF. NO SIGNIFICANT WINDSPEEDS EXPECTED. MESSICK
&&
.PIH WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CARIBOU ME
555 PM EST THU JAN 1 2015
.SYNOPSIS...
AN ARCTIC FRONT WILL SWEEP NORTHWEST TO SOUTHEAST THROUGH THE
REGION LATE TONIGHT INTO FRIDAY. HIGH PRESSURE WILL BUILD ACROSS
THE REGION FRIDAY NIGHT THROUGH SATURDAY. LOW PRESSURE TRACKING
NORTHWEST OF MAINE WILL ALLOW A WARM FRONT TO APPROACH THE REGION
SUNDAY.
&&
.NEAR TERM /THROUGH FRIDAY/...
530 PM UPDATE: MOST OF THIS UPDATE WAS MADE ON REFINING POPS BASED
ON FCST LIQ EQUIV POPS ACROSS THE NW TWO THIRDS OF THE FA. THIS
WAS DONE USING THE LATEST HRLY UPDATED HRRR SIM RADAR REF
OUTPUT...WHICH SHOWS MOST OF THE SN SHWR ACTIVITY XPCTD OVR THE NW
AND FAR NRN PTNS OF THE FA THIS EVE...WITH THIS BAND SLOWLY MOVG
SE LATE TNGT INTO NE PTNS OF THE FA...BEFORE BECOMING LESS
ORGANIZED BY DAYBREAK FRI. WITH THE ACTUAL ARCTIC FRONT XPCTD TO
REMAIN NW OF THE WRN ME/QB BORDER MSLY PRIOR TO 06Z...MOST OF THE
INITIAL SN SHWR ACTIVITY WILL BE FRONTOGENETICALLY FORCED...WITH
ANY LCLY ENHANCED BANDING OF SN RATES MSLY AFT 06Z ALG THE LEADING
EDGE OF THE ARCTIC FRONT AS IT CROSSES THRU NW AND EVENTUALLY NE
ME VERY LATE TNGT. NOT SURE WHETHER THIS BANDING WILL BE INTENSE
ENOUGH TO QUALIFY AS SN SQLS DURG THIS TM OF NGT WHEN SFC-1000M
LAPSE RATES ARE MORE STABLE THAN LATE MORN INTO AFTN...BUT CANNOT
COMPLETELY RULE SN SQL ACTIVITY ATTM. OTHERWISE...MODIFICATIONS
WERE MADE TO CLD CVR AND FCST HRLY TEMPS OVRNGT INTO FRI BASED ON
5 PM SAT IMAGERY AND SFC OBS.
ORGNL DISC: MAIN CONCERN OVERNIGHT CONTINUES TO BE THE POTENTIAL
FOR SNOW SQUALLS LATE MSLY ACROSS NW AND FAR N PTNS OF THE FA.
LOW PRESSURE CURRENTLY CROSSING HUDSON BAY WILL CONTINUE ITS
EASTWARD TREK TONIGHT, DRAGGING ITS ATTENDANT COLD FRONT ALONG
SOUTHERN CANADA/NORTHERN UNITED STATES AS IT DOES SO. THIS FRONT
WILL PUSH INTO NORTHERN MAINE LATE THIS EVENING AND EVENTUALLY MOVE
OFF THE MAINE COAST FRIDAY MORNING. THIS IS A POTENT ARCTIC FRONT
AND WILL SERVE TO DO TWO THINGS. ONE, IT WILL RETURN COLDER AIR TO
THE REGION, AND TWO, IT WILL ALSO SERVE AS A FOCUS FOR SNOW SHOWER
ACTIVITY, ESPECIALLY OVER NORTHERN MAINE. GOOD MOISTURE CONVERGENCE
ALONG THE FRONT, ALONG WITH STEEPENING LAPSE RATES AND PLENTIFUL
LIFT, A BAND OF SNOW SQUALLS WILL BE POSSIBLE, ESPECIALLY OVER THE
SAINT JOHN VALLEY. ANY SQUALLS WILL BE CAPABLE OF PRODUCING
VISIBILITY OF A HALF MILE OR LESS, GUSTY WINDS, AND A QUICK INCH OR
TWO OF SNOW. OUTSIDE OF ANY SQUALLS, EXPECT JUST SCATTERED SNOW
SHOWERS WITH LIGHT ACCUMULATION. TEMPERATURES WILL DROP OFF QUICKLY
BEHIND THE FRONT, WITH OVERNIGHT LOWS RETURNING INTO THE SINGLE
DIGITS ACROSS THE NORTHERN PORTIONS OF THE COUNTY. ELSEWHERE,
TEMPERATURES WILL BE IN THE TEENS TO MID 20S.
FOR FRIDAY...THE AFOREMENTIONED FRONT WILL FINISH ITS SOUTHWARD PUSH
AND WILL BE OFFSHORE BY AFTERNOON. AS SUCH, THE BULK OF THE SNOW
SHOWERS WILL COME TO AN END WITH JUST A FEW LINGERING SNOW FLAKES
POSSIBLE OVER NORTHERN MAINE. HIGHS WILL BE CHILLY IN THE
NORTH...10 TO 15 DEGREES...BUT CENTRAL AND SOUTHERN MAINE WILL BE A
BIT BETTER, TOPPING OUT IN THE 20S TO AROUND 30.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
COULD HAVE A SLIGHT CHANCE OF SNOW SHOWERS ACROSS THE
NORTH/MOUNTAINS EARLY FRIDAY NIGHT. OTHERWISE...HIGH PRESSURE
BUILDS EAST TOWARD THE REGION FRIDAY NIGHT WITH DECREASING CLOUDS
NORTH AND MOSTLY CLEAR SKIES DOWNEAST. HIGH PRESSURE THEN CROSSES
THE REGION SATURDAY WITH PARTLY/MOSTLY SUNNY SKIES. LOW PRESSURE
LIFTING ACROSS THE GREAT LAKES WILL DRAW A WARM FRONT TOWARD NEW
ENGLAND SATURDAY NIGHT. CLOUD COVER WILL INCREASE ACROSS THE
REGION EARLY SATURDAY NIGHT. LOW TEMPERATURES SATURDAY NIGHT WILL
OCCUR EARLY THEN BEGIN TO RISE OVERNIGHT WITH THE INCREASING
CLOUDS. OVERRUNNING PRECIPITATION WILL THEN EXPAND ACROSS THE
FORECAST AREA LATER SATURDAY NIGHT. BASED ON CRITICAL
THICKNESSES...EXPECT PRECIPITATION TO REMAIN MOSTLY IN THE FORM OF
SNOW ACROSS THE FORECAST AREA SATURDAY NIGHT. HOWEVER...THE SNOW
COULD BEGIN TO TRANSITION TO A WINTRY MIX ACROSS DOWNEAST AREAS
LATE. THE PRIMARY GREAT LAKES LOW TRACKS NORTHWEST OF THE REGION
SUNDAY DRAWING THE WARM FRONT NORTH ACROSS THE REGION. MODELS
INDICATE THE POSSIBILITY THAT A WEAK SECONDARY LOW COULD DEVELOP
ALONG THE WARM FRONT AND MOVE ALONG THE COAST...THOUGH THE EXTENT
TO WHICH THE LOW DEVELOPS IS UNCERTAIN. EXPECT A WINTRY MIX TO
TRANSITION TO MOSTLY RAIN ACROSS MUCH OF THE DOWNEAST AREA SUNDAY
AFTERNOON...WITH SNOW TRANSITIONING TO A WINTRY MIX ACROSS
NORTHERN AREAS. PRECIPITATION TYPES WILL BE DEPENDENT ON HOW
QUICKLY THE LOW LEVEL COLD AIR CAN BE ERODED. A STRONGER SECONDARY
LOW MOVING ALONG THE COAST WOULD HELP THE LOW LEVEL COLD AIR
REMAIN MORE PERSISTENT ACROSS INTERIOR DOWNEAST AREAS...WHILE A
WEAKER LOW WOULD ALLOW THE LOW LEVEL COLD AIR TO BE ERODED MORE
RAPIDLY. GENERALLY EXPECT STORM TOTAL SNOW ACCUMULATION OF 4 TO 7
INCHES ACROSS NORTHERN AREAS THROUGH SUNDAY WITH 3 TO 5 INCHES
DOWNEAST. SLEET AND ICE ACCUMULATIONS WILL BE DEPENDENT ON THE
TIMING OF THE TRANSITION FROM SNOW WHICH IS STILL UNCERTAIN AT
THIS TIME. TEMPERATURES WILL BE AT BELOW NORMAL LEVELS
SATURDAY...THEN AT ABOVE NORMAL LEVELS SUNDAY DEPENDENT ON THE
EXTENT OF LOW LEVEL WARMING.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
LATEST RUN OF GFS/ECMWF IN GOOD AGREEMENT TRACKING LOW PRESSURE
NORTH OF CWA THROUGH MONDAY WITH STRONG NORTHWEST TO NORTH
GRADIENT ESTABLISHING FOR GUSTY WINDS AND A RAPID DECREASE IN
TEMPERATURES. SNOW SHOWER ACTIVITY...OR MIXED PRECIPITATION ALONG
DOWNEAST...WILL DIMINISH QUICKLY ACROSS THE AREA BY MONDAY NIGHT.
ANOTHER LOW APPROACHES FROM THE GREAT LAKES ON TUESDAY BUT CURRENT
GUIDANCE KEEPS THE SYSTEM OFFSHORE RESULTING IN CHANCE POPS ALONG
DOWNEAST COAST AND SLIGHT CHANCE TO CENTRAL AREAS THROUGH EARLY
THURSDAY. HIGH PRESSURE THEN BUILDS IN FROM THE WEST ON THURSDAY
FOR A BRIEF RESPITE BEFORE A CLIPPER SYSTEM APPROACHES AGAIN FROM
THE WEST. TEMPERATURES THROUGH THE WEEK WILL REMAIN WELL BELOW
NORMALS.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
NEAR TERM: VFR CONDITIONS WILL PREVAIL AT THE SOUTHERN TERMINALS
THROUGH THE PERIOD. HOWEVER, AT KCAR/KFVE/KPQI, A COLD FRONTAL
PASSAGE WILL BRING SNOW SHOWERS AND PERHAPS EVEN SNOW SQUALLS.
PREVAILING MVFR CONDITIONS ARE EXPECTED 22Z THU THRU 12Z FRIDAY,
WITH IFR/LIFR POSSIBLE IN ANY SNOW. CONDITIONS WILL IMPROVE
THROUGH THE DAY FRIDAY WITH LIFTING CEILINGS AND DECREASING
COVERAGE OF SNOW SHOWERS.
SHORT TERM: COULD HAVE LOCALIZED MVFR CONDITIONS ACROSS THE
NORTH AND MOUNTAINS EARLY FRIDAY NIGHT. OTHERWISE...VFR
CONDITIONS ARE EXPECTED ACROSS THE REGION FRIDAY NIGHT INTO EARLY
SATURDAY NIGHT. CONDITIONS WILL LOWER TO IFR/LIFR LEVELS LATER
SATURDAY NIGHT WITH SIMILAR CONDITIONS PERSISTING INTO EARLY
SUNDAY NIGHT. CONDITIONS WILL IMPROVE TO MVFR/VFR LEVELS ACROSS
NORTHERN AREAS LATER SUNDAY NIGHT...WITH VFR CONDITIONS DEVELOPING
DOWNEAST. OCCASIONAL MVFR CONDITIONS COULD PERSIST ACROSS THE
NORTH AND MOUNTAINS MONDAY. OTHERWISE...VFR CONDITIONS ARE
EXPECTED ACROSS THE REGION MONDAY INTO TUESDAY.
&&
.MARINE...
NEAR TERM: A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR TONIGHT,
BUT IT HAS BEEN EXTENDED THROUGH FRIDAY. WINDS WILL INCREASE AHEAD
OF AN APPROACHING COLD FRONT TONIGHT, AND THEN SWITCH TO THE
WEST/NORTHWEST FRIDAY AS THE FRONT CROSSES THE GULF OF MAINE.
WINDS OF 15 TO 20 KT WITH GUSTS TO 30 KT ARE EXPECTED THROUGH THE
PERIOD.
SHORT TERM: SMALL CRAFT ADVISORY CONDITIONS WILL OCCUR FRIDAY
NIGHT INTO EARLY SATURDAY. CONDITIONS WILL BRIEFLY FALL BELOW
SMALL CRAFT ADVISORY LEVELS SATURDAY AFTERNOON INTO EARLY
SATURDAY NIGHT. SMALL CRAFT ADVISORY CONDITIONS WILL DEVELOP AGAIN
LATER SATURDAY NIGHT. STRONG SMALL CRAFT ADVISORY...OR POSSIBLY
GALE CONDITIONS...WILL OCCUR SUNDAY. VISIBILITIES WILL LOWER IN
DEVELOPING SNOW AND MIXED PRECIPITATION LATER SATURDAY
NIGHT...WITH MIXED PRECIPITATION CHANGING TO RAIN SUNDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST SATURDAY FOR ANZ050>052.
&&
$$
NEAR TERM...VJN
SHORT TERM...NORCROSS
LONG TERM...PJR
AVIATION...VJN/NORCROSS
MARINE...VJN/NORCROSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
410 PM EST THU JAN 1 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 351 PM EST THU JAN 1 2015
DEEP TROUGH ALOFT CENTERED OVER HUDSON BAY. MULTIPLE SHORTWAVES
MOVING THROUGH THE BASE OF THE TROUGH...BUT AFTER THE SHORTWAVE
MOVED THROUGH THIS MORNING...THERE IS NO LARGER SCALE SUPPORT OVER
THE AREA OR UPSTREAM. PRIMARY COLD FRONT TIED TO THE LAST SHORTWAVE
IS CURRENTLY SINKING SOUTHWARD OVER UPR MICHIGAN. BAND OF HEAVY SNOW
ALONG THE FRONT HAS WORKED THROUGH MARQUETTE AND MUNISING AND IS NOW
ALLIGNED FM SAWYER TO CHATHAM TO SHINGLETON AND TO NEWBERRY AS OF 20Z.
VSBY DOWN TO 1/4SM IN THIS SNOW BAND...BUT IT IS NOT LASTING TOO LONG.
LES OVER THE WESTERN CWA IS SCUFFLING ALONG. IN FACT AFTER THE FRONT
MOVED THROUGH THE KEWEENAW...SPOTS HAVE CLEARED OUT BRIEFLY. HINTS OF
WIND PARALLEL BANDS OVER WESTERN LK SUPERIOR...BUT DRY AIR AND
INVERSIONS BLO 5KFT IS LIMITING THIS DEVELOPMENT. BETTER LES
DEVELOPMENT OVER EASTERN LK SUPERIOR WITH CLOUD STREETS EXTENDING
BACK TO NCNTRL LK SUPERIOR. WILL TAKE A FEW HOURS...BUT DO EXPECT AT
LEAST MODERATE LES TO DEVELOP IN THE NW LOW-LEVEL WINDS INTO EASTERN
CWA. BLYR WINDS OVER 30 KTS INTO THE EVENING WILL RESULT IN BLSN/POOR
VSBY IN THE HEAVIER SNOW BANDS. INVERSIONS 5-8 KFT AND TEMPS AT
INVERSION TOP OF -20C SHOULD AT LEAST RESULT IN SCT HEAVIER SNOW
SHOWERS. 17Z HRRR DOING NICE JOB WITH EXPECTED EVOLUTION THROUGH THE
EVENING...THOUGH IT SEEMS A BIT SLOW WITH TIMING OF HEAVIER SNOW BAND
TIED TO THE FRONT.
ADDITIONAL SNOW AMOUNTS SHOULD STAY IN CHECK GIVEN LACK OF ENHANCED
MOISTURE AND LIFT SINCE WE ARE WITHIN A PURE LES REGIME. SUPPOSE IF
SNOW BANDS CAN STAY ANCHORED IN ONE PLACE THROUGH THE NIGHT...MAY SEE
SEVERAL INCHES OF FLUFFY ACCUMS AS ALL CONVECTIVE DEPTH IS WITHIN THE
DGZ. ALREADY ISSUED LES ADVISORY THROUGH MIDNIGHT FOR ALGER...NORTHERN
SCHOOLCRAFT...AND LUCE COUNTIES. AFTER MIDNIGHT SEEMS THAT DRY AIR
AND LOWER INVERSIONS THAT ARE AFFECTING WESTERN LK SUPERIOR AND CWA
WILL PUT CRIMP IN THE LES INTENSITY OVERNIGHT. WEAK LES WILL CONTINUE
INTO FRIDAY...MAINLY FOR AREAS FAVORED BY WNW-W WINDS...SO ESSENTIALLY
THE SNOW BELTS OF THE KEWEENAW AND ALSO TO THE EAST OF MUNISING.
CONDITIONS EVEN MORE UNFAVORABLE THAN LATER TONIGHT...BUT WITH DGZ
DOMINATING THE CONVECTIVE LAYER STILL COULD SQUEEZE OUT A COUPLE MORE
INCHES OF FLUFF IN PERSISTENT SNOW SHOWERS.
AWAY FM THE LES TONIGHT...LOWERED SKY COVER AND TEMPERATURES AS THE
DRIER AIR SHOULD WIN OUT AS IS OCCURRING UPSTREAM IN MINNESOTA AND
NORTHWEST ONTARIO THIS AFTN. INTERIOR TEMPS SHOULD DIP WELL BLO ZERO
ONCE THE NW WINDS BEHIND THE COLD FRONT BEGIN TO BACK OFF. SHOULD BE
SHARP GRADIENT TO MIN TEMPS AS YOU GET CLOSER TO LK SUPERIOR DUE TO
LINGERING LAKE EFFECT CLOUDS AS 925MB WINDS STAY WNW-NW THROUGH THE
NIGHT. ALSO MAY SEE TEMPS STEADY OR RISE LATE IN THE WEST WITH
ADVANCING DECK OF 6-9KFT ALTOSTRATUS CLOUDS. ANOTHER COOL DAY WITH
AFTN READINGS IN THE TEENS OVER THE CWA.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 408 PM EST THU JAN 1 2015
A PROMINENT RIDGE GRADUALLLY BUILDING TO THE EAST INTO WRN NOAM WILL
MAINTAIN A BROAD TROUGH FROM CENTRAL CANADA INTO THE GREAT LAKES.
AFTER LOW PRESSURE SYSTEM LIFTS NE FROM THE CNTRL GREAT LAKES...MUCH
COLDER AIR WILL MOVE INTO THE REGION AND REMAIN THROUGH MUCH OF NEXT
WEEK KEEPING LES GOING FOR MAINLY NW TO WNW FLOW FAVORED LOCATIONS.
FRI NIGHT AND SAT...A BROAD 850-600 MB WARM ADVECTION 280K-295
ISENTROPIC LIFT ZONE WILL DEVELOP FROM THE NRN PLAINS INTO NRN MN AND NRN
LAKE SUPERIOR IN RESPONSE TO THE DEVELOPING TROUGH OVER THE PLAINS
AND UPPER LEVEL DIV WITH THE RIGHT ENTRANCE OF A 250-300 MB JET
STREAK THROUGH NRN ONTARIO. THE MODELS KEEP MOST OF THE PCPN WITH
THIS FEATURE NORTH OF UPPER MI. WAA WILL RAISE TEMPS AT OR
SLIGHTLY ABOVE AVERAGE WITH READINGS IN THE MID TO UPPER 20S.
SAT NIGHT INTO SUN...A SHRTWV ORIGINATING FROM THE GULF OF ALASKA
DIVING INTO THE WRN CONUS TROUGH WILL HELP EJECT THE SW CLOSED LOW
NE TOWARD THE GREAT LAKES. THE 12Z GFS/ECMWF ALONG WITH ENSEMBLES
FAVOR A LOW TRACK FROM THE SRN END OF LAKE MI TO CNTRL LAKE HURON
AND THEN NE INTO QUEBEC. STRONG 700-300 MB QVECTOR CONV ASSOCIATED
WITH THE SHRTWV WILL SUPPORT A BROAD AREA OF SNOW FROM WI INTO UPPER
MI BY LATE SAT AND ESPECIALLY LATE SAT NIGHT. MDLS CONSENSUS QPF IN
THE 0.20 TO 0.35 INCH RANGE WITH SLR VALUES AROUND 14/1 WILL SUPPORT
POTENTIAL FOR 3 TO 6 INCHES BY 18Z/SUN. ADDITIONAL SUPPORT FOR
HEAVIER SNOW IS EXPECTED OVER THE NORTH CYCLONIC NRLY FLOW AND 850
MB TEMPS DROPPING FROM -10C TO -15C BY 12Z TO -14C TO -19C BY 18Z
WILL RESULT HIGHER AMOUNTS THROUGH LAKE ENHANCEMENT. BY SUN
AFTERNOON THE DEEPER MOISTURE AND SYNOPTIC SUPPORT LIFT QUICKLY WITH
A TRANSITION TO LIGHTER PURE LES.
SUN NIGHT INTO MON...VERY COLD ARCTIC AIR WILL PLUNGE INTO THE
REGION WITH 850 MB TEMPS DROPPING TO AROUND -27C BY 12Z MON. THIS
WILL LOWER THE DGZ TOWARD THE SFC AND REDUCE POTENTIAL FOR
SIGNIFICANT LES. HOWEVER...WIND CHILL WITH A MORE WRLY SFC WIND
COMPONENT RESULTING FROM LAKE INDUCED TROUGHING WILL ALLOW TEMPS TO
DROP OFF OVER MUCH OF THE CWA. WIND CHILL VALUES IN THE -20 TO -35
RANGE ARE EXPECTED.
TUE-THU...A FEW CLIPPER SHRTWVS ARE LIKELY TO MOVE THROUGH THE REGION WITH
NW-NNW MID LEVEL FLOW IN PLACE. THIS MAY BRING REINFORCING BOUTS OF
COLD AIR AND SHIFT THE POSITIONS OF THE HEAVIER LES BANDS. TEMPS MAY
MODERATE SLIGHTLY IF SFC WINDS VEER MORE TO THE NW WITH MORE MARINE
MODIFICATION. HOWEVER...WIND CHILLS MAY REMAIN NEAR ADVY THRESHOLD
DURING THE LATER NIGHT INTO MORNING HOURS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1243 PM EST THU JAN 1 2015
COLD FRONT HAS MADE IT THROUGH KCMX AND WILL IMPACT KIWD AND KSAW
WITH A PERIOD OF SNOW SHOWERS AND BLOWING SNOW THIS AFTN. AT KIWD
AND KSAW...GENERALLY THE CIGS WILL BE MVFR INTO TONIGHT. VSBY WILL
BE IFR OR MVFR...BUT WILL BEGIN TO IMPROVE BY EARLY EVENING AS DRIER
AIR ERODES THE LAKE EFFECT SNOW SHOWERS. WILL SEE IMPROVEMENT TO VFR
LATE TONIGHT INTO FRIDAY AT KIWD AND KSAW. AT KCMX...PERSISTENT WNW-
NW FLOW OFF LK SUPERIOR WILL KEEP LAKE EFFECT SNOW SHOWERS WITH IFR
TO MVFR VSBY THROUGH THE PERIOD. STRONGEST WINDS WITH BLSN THIS
AFTN...THEN WINDS DIMINISH SIGNIFICANTLY THIS EVENING AND OVERNIGHT
TONIGHT.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 351 PM EST THU JAN 1 2015
NW GALES DIMINISH THIS EVENING OVER THE EAST HALF. HEAVY FREEZING
SPRAY WILL ALSO END LATE TONIGHT. WINDS SETTLE DOWN TO LESS THAN 25
KTS LATER TONIGHT THROUGH FRIDAY NIGHT AS HIGH PRESSURE MOVES
OVERHEAD. EXPECT A BRIEF PERIOD OF STRONGER SE WINDS ON SATURDAY...BUT
THE BETTER CHANCE OF STRONGER WINDS WILL BE LATE SATURDAY NIGHT INTO
SUNDAY AS NORTH TO NORTHWEST WINDS INCREASE AS A LOW PRESSURE SYSTEM
LIFTS OVER THE GREAT LAKES THEN MOVES EAST OVER QUEBEC. BEST SHOT OF
GALES WILL BE OVER THE EAST HALF OF LK SUPERIOR ON SUNDAY. NW WINDS
TO 30 KTS WILL LINGER OVER MUCH OF LK SUPERIOR INTO EARLY NEXT WEEK
BEHIND THE WEEKEND SYSTEM. MORE HEAVY FREEZING SPRAY IS EXPECTED LATE
THIS WEEKEND INTO EARLY NEXT WEEK AS ARCTIC AIR FLOWS ACROSS LK
SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR MIZ006-
007-085.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 1 AM EST FRIDAY FOR LSZ265-
267.
GALE WARNING UNTIL 6 PM EST THIS EVENING FOR LSZ266-267.
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST /6 AM CST/ FRIDAY
FOR LSZ241>245-263-264-266.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...JLB
AVIATION...JLA
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
353 PM EST THU JAN 1 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 351 PM EST THU JAN 1 2015
DEEP TROUGH ALOFT CENTERED OVER HUDSON BAY. MULTIPLE SHORTWAVES
MOVING THROUGH THE BASE OF THE TROUGH...BUT AFTER THE SHORTWAVE
MOVED THROUGH THIS MORNING...THERE IS NO LARGER SCALE SUPPORT OVER
THE AREA OR UPSTREAM. PRIMARY COLD FRONT TIED TO THE LAST SHORTWAVE
IS CURRENTLY SINKING SOUTHWARD OVER UPR MICHIGAN. BAND OF HEAVY SNOW
ALONG THE FRONT HAS WORKED THROUGH MARQUETTE AND MUNISING AND IS NOW
ALLIGNED FM SAWYER TO CHATHAM TO SHINGLETON AND TO NEWBERRY AS OF 20Z.
VSBY DOWN TO 1/4SM IN THIS SNOW BAND...BUT IT IS NOT LASTING TOO LONG.
LES OVER THE WESTERN CWA IS SCUFFLING ALONG. IN FACT AFTER THE FRONT
MOVED THROUGH THE KEWEENAW...SPOTS HAVE CLEARED OUT BRIEFLY. HINTS OF
WIND PARALLEL BANDS OVER WESTERN LK SUPERIOR...BUT DRY AIR AND
INVERSIONS BLO 5KFT IS LIMITING THIS DEVELOPMENT. BETTER LES
DEVELOPMENT OVER EASTERN LK SUPERIOR WITH CLOUD STREETS EXTENDING
BACK TO NCNTRL LK SUPERIOR. WILL TAKE A FEW HOURS...BUT DO EXPECT AT
LEAST MODERATE LES TO DEVELOP IN THE NW LOW-LEVEL WINDS INTO EASTERN
CWA. BLYR WINDS OVER 30 KTS INTO THE EVENING WILL RESULT IN BLSN/POOR
VSBY IN THE HEAVIER SNOW BANDS. INVERSIONS 5-8 KFT AND TEMPS AT
INVERSION TOP OF -20C SHOULD AT LEAST RESULT IN SCT HEAVIER SNOW
SHOWERS. 17Z HRRR DOING NICE JOB WITH EXPECTED EVOLUTION THROUGH THE
EVENING...THOUGH IT SEEMS A BIT SLOW WITH TIMING OF HEAVIER SNOW BAND
TIED TO THE FRONT.
ADDITIONAL SNOW AMOUNTS SHOULD STAY IN CHECK GIVEN LACK OF ENHANCED
MOISTURE AND LIFT SINCE WE ARE WITHIN A PURE LES REGIME. SUPPOSE IF
SNOW BANDS CAN STAY ANCHORED IN ONE PLACE THROUGH THE NIGHT...MAY SEE
SEVERAL INCHES OF FLUFFY ACCUMS AS ALL CONVECTIVE DEPTH IS WITHIN THE
DGZ. ALREADY ISSUED LES ADVISORY THROUGH MIDNIGHT FOR ALGER...NORTHERN
SCHOOLCRAFT...AND LUCE COUNTIES. AFTER MIDNIGHT SEEMS THAT DRY AIR
AND LOWER INVERSIONS THAT ARE AFFECTING WESTERN LK SUPERIOR AND CWA
WILL PUT CRIMP IN THE LES INTENSITY OVERNIGHT. WEAK LES WILL CONTINUE
INTO FRIDAY...MAINLY FOR AREAS FAVORED BY WNW-W WINDS...SO ESSENTIALLY
THE SNOW BELTS OF THE KEWEENAW AND ALSO TO THE EAST OF MUNISING.
CONDITIONS EVEN MORE UNFAVORABLE THAN LATER TONIGHT...BUT WITH DGZ
DOMINATING THE CONVECTIVE LAYER STILL COULD SQUEEZE OUT A COUPLE MORE
INCHES OF FLUFF IN PERSISTENT SNOW SHOWERS.
AWAY FM THE LES TONIGHT...LOWERED SKY COVER AND TEMPERATURES AS THE
DRIER AIR SHOULD WIN OUT AS IS OCCURRING UPSTREAM IN MINNESOTA AND
NORTHWEST ONTARIO THIS AFTN. INTERIOR TEMPS SHOULD DIP WELL BLO ZERO
ONCE THE NW WINDS BEHIND THE COLD FRONT BEGIN TO BACK OFF. SHOULD BE
SHARP GRADIENT TO MIN TEMPS AS YOU GET CLOSER TO LK SUPERIOR DUE TO
LINGERING LAKE EFFECT CLOUDS AS 925MB WINDS STAY WNW-NW THROUGH THE
NIGHT. ALSO MAY SEE TEMPS STEADY OR RISE LATE IN THE WEST WITH
ADVANCING DECK OF 6-9KFT ALTOSTRATUS CLOUDS. ANOTHER COOL DAY WITH
AFTN READINGS IN THE TEENS OVER THE CWA.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 501 AM EST THU JAN 1 2015
PERSISTENT RIDGING OVER THE EASTERN PACIFIC/NAMERICA WEST COAST
REGION WILL MAINTAIN A BROAD UPPER TROUGH OVER MUCH OF CANADA AND
THE GREAT LAKES REGION THROUGH THE FIRST WEEK OF JANUARY RESULTING
IN BELOW NORMAL TEMPERATURES AND PERIODS OF LAKE EFFECT SNOW FOR
UPPER MI.
BEGINNING FRIDAY...MODEL CONSENSUS SUGGESTS WINDS WL BACK MORE
WESTERLY AGAIN AS SFC RDG AXIS ADVANCES ACROSS AREA FROM THE NRN
PLAINS. THE GENERALLY WEAK WRLY FLOW ALONG WITH ENHANCED LOW-LVL
CONVERGENCE FROM LAND BREEZES WL HELP FOCUS GENERALLY LIGHT LAKE
EFFECT SNOW ACROSS THE KEWEENAN PENINSULA AND THE FAR ERN SHORELINE
OF THE CWA AS INVERSION BASES CRASH BLO 5KFT WITH DRY AIR NOTED
BENEATH THE INVERSION. SINCE MUCH OF THE DGZ IN STILL WITHIN THE
CLOUD LAYER...LES BANDS COULD YIELD 1-2 INCHES OF FLUFFY
ACCUMULATION DURING THE DAY. WAA CLOUDS AHEAD OF SHORTWAVE MOVING IN
FROM THE NRN PLAINS WILL LIMIT RADIATIONAL COOLING FRIDAY NIGHT BUT
TEMPS SHOULD STILL APPROACH ZERO OR MAYBE EVEN DIP BLO ZERO AT A FEW
OF THE TYPICAL COLDER LOCATIONS OVER THE WESTERN INTERIOR.
THIS WEEKEND...FOCUS IS ON PHASING/INTERACTION OF SPLIT FLOW. TWO
FEATURES WILL COME INTO PLAY...ONE WILL BE THE REMNANTS OF A CLOSED
LOW NOW PRODUCING SNOW OVER THE SW CONUS...AND THE SECOND IS A NRN
BRANCH SHORTWAVE NOW OVER THE ALEUTIAN ISLANDS WHICH IS FCST TO DIVE
SE ACROSS THE NRN ROCKIES FRI NIGHT AND THEN THROUGH THE PLAINS
STATES ON SAT. ASSOCIATED STRONG MID LEVEL WARM AIR ADVECTION AHEAD
OF THIS SHORTWAVE AND ITS ASSOC SFC LOW WILL SPREAD SNOW EAST INTO
MAINLY THE NORTHWEST HALF OF THE CWA ON SAT. WHILE THE MODELS STILL
PEG THE HEAVIEST SNOW TO OCCUR OVER LAKE SUPERIOR...WILL CONTINUE TO
SHOW SOME LIKELY POPS OVER AND AROUND THE KEWEENAW PENINSULA FOR
SATURDAY. AS THIS SNOW IS OCCURRING...THE NORTHERN SHORTWAVE WILL
CONTINUE TO DIVE SOUTHEAST AND BEGIN TO PHASE WITH THE REMNANTS OF
THE SW CONUS UPPER LOW WHICH WILL LEAD TO BOTH FEATURES EJECTING
NORTHEAST THROUGH THE LOWER GREAT LAKES REGION SATURDAY NIGHT INTO
SUNDAY. THE 00Z ECMWF...GFS AND NAM ALL TRENDING DEEPER AND FARTHER
WEST WITH RESULTING SFC LOW WHICH BLEND OF THESE MODELS SHOW A TRACK
THROUGH SRN LWR MI TO NEAR GEORGIAN BAY BY 12Z SUNDAY. THE GEM-NH
MEANWHILE AFTER SHOWING A SIMILAR TRACK TO THE 00Z ECMWF/GFS BLEND
HAS NOW TRENDED FARTHER EAST THROUGH SE LOWER MI INTO ERN ONTARIO.
IF THE LATEST GFS/ECMWF SOLNS HOLD TRUE THIS WOULD MEAN A GREATER
POTENTIAL FOR SYNOPTIC PCPN TO SPREAD INTO UPPER MI...ESPECIALLY THE
EAST HALF...ALONG WITH A GREATER POTENTIAL FOR NORTH FLOW LAKE
ENHANCED SNOW ON THE BACKSIDE OF THE SYSTEM. WILL LIKELY NEED TO
TREND POPS UPWARD ACROSS THE CWA AND ESPECIALLY ALONG LAKE SUPERIOR
ZONES WITH A GREATER POTENTIAL FOR LAKE ENHANCED SNOW SAT NIGHT INTO
SUNDAY. WINDS WILL ALSO RAMP UP WITH TIGHTER GRADIENT ON BACKSIDE OF
SYSTEM WHICH WILL ALSO RESULT IN MORE BLOWING SNOW. WILL HIGHLIGHT
POTENTIAL FOR MODERATE SNOW AND BLOWING SNOW IN HWO...ESPECIALLY
ALONG LAKE SUPERIOR AND THE EAST HALF OF THE CWA FOR SAT NIGHT INTO
SUNDAY EVENING.
LATE SUNDAY NIGHT INTO MONDAY NIGHT...WEAKENING PRES GRADIENT WILL
ALLOW WINDS TO DIMINISH ESPECIALLY OVER THE INTERIOR. WINDS WILL
ALSO BE BACKING MORE WESTERLY ESPECIALLY BY MONDAY IN ADVANCE OF
STRONG SFC HIGH PRES RDG BUILDING IN FROM THE NRN PLAINS...SO EXPECT
LES TO EVENTUALLY BECOME MORE CONFINED TO KEWEENAW AND FAR ERN
SHORELINE AREAS OF THE CWA MONDAY AFTERNOON INTO MON NIGHT. WITH
HEART OF COLDEST AIR (850 MB TEMPS OF -26 TO -28C) COMING ACROSS THE
UPPER LAKES...EXPECT VERY COLD TEMPS SUN NIGHT AND MONDAY. EXPECT
MUCH OF THE INTERIOR CWA TO FALL BLO ZERO AND WOULD NOT BE SURPRISED
TO SEE SOME WESTERN INTERIOR LOCATIONS FALL WELL INTO THE TEENS BLO
ZERO... ESPECIALLY ALONG THE WI BORDER. HIGHS MONDAY WILL REMAIN
VERY COLD WITH READINGS RANGING FROM THE SINGLE DIGITS BLO ZERO
WESTERN INTERIOR TO THE SINGLE DIGITS ABV ZERO EAST AND ALONG THE
GREAT LAKES.
TUESDAY INTO WEDNESDAY...MODELS IN REASONABLY GOOD AGREEMENT SHOWING
ANOTHER CLIPPER SHORTWAVE MOVING ACROSS THE UPPER GREAT LAKES ON
TUESDAY WITH ANOTHER REINFORCING SHOT OF ARCTIC AIR (8H TEMPS FALL
AGAIN TO -28C TO -30C) AS WINDS VEER TO THE NW. THIS WILL BRING LES
FARTHER INLAND AGAIN AFFECTING THE NRN TIER AND ERN HALF COUNTIES
FROM LATE TUE THROUGH WED. LOOK LIKE ONLY THE FAR SOUTH CENTRAL
WOULD ESCAPE THE LES. WITH SUCH A COLD ARCTIC AIRMASS FCST THE DGZ
WILL GET SQUASHED NEAR THE LAKE SFC WHICH WILL LIKELY RESULT IN
SMALLER FLAKE SIZE. THIS WILL LIMIT LES ACCUMULATION BUT AT SAME
TIME WILL BE MORE EFFECTIVE FOR REDUCING VSBY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1243 PM EST THU JAN 1 2015
COLD FRONT HAS MADE IT THROUGH KCMX AND WILL IMPACT KIWD AND KSAW
WITH A PERIOD OF SNOW SHOWERS AND BLOWING SNOW THIS AFTN. AT KIWD
AND KSAW...GENERALLY THE CIGS WILL BE MVFR INTO TONIGHT. VSBY WILL
BE IFR OR MVFR...BUT WILL BEGIN TO IMPROVE BY EARLY EVENING AS DRIER
AIR ERODES THE LAKE EFFECT SNOW SHOWERS. WILL SEE IMPROVEMENT TO VFR
LATE TONIGHT INTO FRIDAY AT KIWD AND KSAW. AT KCMX...PERSISTENT WNW-
NW FLOW OFF LK SUPERIOR WILL KEEP LAKE EFFECT SNOW SHOWERS WITH IFR
TO MVFR VSBY THROUGH THE PERIOD. STRONGEST WINDS WITH BLSN THIS
AFTN...THEN WINDS DIMINISH SIGNIFICANTLY THIS EVENING AND OVERNIGHT
TONIGHT.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 351 PM EST THU JAN 1 2015
NW GALES DIMINISH THIS EVENING OVER THE EAST HALF. HEAVY FREEZING
SPRAY WILL ALSO END LATE TONIGHT. WINDS SETTLE DOWN TO LESS THAN 25
KTS LATER TONIGHT THROUGH FRIDAY NIGHT AS HIGH PRESSURE MOVES
OVERHEAD. EXPECT A BRIEF PERIOD OF STRONGER SE WINDS ON SATURDAY...BUT
THE BETTER CHANCE OF STRONGER WINDS WILL BE LATE SATURDAY NIGHT INTO
SUNDAY AS NORTH TO NORTHWEST WINDS INCREASE AS A LOW PRESSURE SYSTEM
LIFTS OVER THE GREAT LAKES THEN MOVES EAST OVER QUEBEC. BEST SHOT OF
GALES WILL BE OVER THE EAST HALF OF LK SUPERIOR ON SUNDAY. NW WINDS
TO 30 KTS WILL LINGER OVER MUCH OF LK SUPERIOR INTO EARLY NEXT WEEK
BEHIND THE WEEKEND SYSTEM. MORE HEAVY FREEZING SPRAY IS EXPECTED LATE
THIS WEEKEND INTO EARLY NEXT WEEK AS ARCTIC AIR FLOWS ACROSS LK
SUPERIOR. &&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR MIZ006-
007-085.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 1 AM EST FRIDAY FOR LSZ265-
267.
GALE WARNING UNTIL 6 PM EST THIS EVENING FOR LSZ266-267.
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST /6 AM CST/ FRIDAY
FOR LSZ241>245-263-264-266.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...VOSS
AVIATION...JLA
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1246 PM EST THU JAN 1 2015
.UPDATE...
ISSUED AT 1107 AM EST THU JAN 1 2015
WIDESPREAD NOAA WEATHER RADIO OUTAGE ACROSS UPR MICHIGAN CONTINUES
AT THIS HOUR DUE TO LARGER SCALE COMMS OUTAGE WITH VERIZON.
SHORTWAVE WITH WIDEPSREAD LGT SNOW IS EXITING EASTERN CWA. SFC
COLD FRONT IS FINALLY STARTING TO SINK ACROSS SOUTHERN HALF OF LK
SUPERIOR THOUGH IT IS TAKING ITS TIME IN DOING SO. LES OVER THE
KEWEENAW THIS MORNING HAS BEEN HEAVY WITH 1+ INCH PER HOUR RATES.
EXPECT LES TO BECOME LESS FOCUSED THOUGH THROUGH MIDDAY AS WINDS
SHIFT FROM THE STRONG CONVERGENT WESTERLY FLOW TO A MORE SHEARED
NORTHWEST FLOW BEHIND THE COLD FRONT. LAKE EFFECT SNOW ADVISORY
SET TO EXPIRE AT 18Z TODAY FOR NORTHERN HOUGHTON AND KEWEENAW
COUNTIES. BASED ON EXPECTED TRENDS IN LES AND WIND THAT LOOKS GOOD
AND WILL NOT MAKE ANY EXTENSIONS ATTM.
ATTN THEN TURNS TO FROPA OVER EASTERN CWA EARLY TO MID AFTN. EXPECT
DECENT CONVERGENCE BAND TO FIRST AFFECT SNOW BELTS EAST OF MARQUETTE
THEN NW FLOW LES WILL DEVELOP. RAP SOUNDINGS INDICATE INVERSIONS TO
7-8KFT WITH TEMPS AROUND -20C AT INVERSION TOP THROUGH EARLY
EVENING. MIXED LAYER WINDS 25-35 KTS WILL RESULT IN WINDY CONDITIONS
AFTER FROPA WITH BLSN/POOR VSBY. WOULD EXPECT SNOWFALL RATES BTWN
0.5-1.0 INCH PER HOUR THIS AFTN INTO THE EARLY EVENING. MUCH OF THE
CONVECTIVE LAYER IS WITHIN THE DGZ...SO SLR/S WILL BE WELL OVER
20:1.
OPTED TO ISSUE A LAKE EFFECT SNOW ADVISORY FOR ALGER...NORTHERN
SCHOOLCRAFT...AND LUCE COUNTIES THROUGH THE EVENING. SNOW AND BLSN
WILL MAKE TRAVEL DIFFICULT INTO THE EARLY EVENING WITH VSBY DOWN TO
1/4SM AT TIMES...AND SNOW AMOUNTS WILL BE BOOSTED BY HIGHER SLR/S
AND DECENTLY HIGH INVERSIONS. IN WAKE OF FROPA LATE THIS EVENING AND
OVERNIGHT TONIGHT...EXPECT DIMINISHING LES AS INVERSIONS FALL BLO
5KFT...BUT DIMINISHING WINDS AND MOST OF THE CONVECTIVE LAYER WITHIN
THE DGZ WILL STILL BOOST SNOW AMOUNTS. EXPECT SNOW TOTALS TODAY INTO
THIS EVENING OF 2 TO 4 INCHES AND ANOTHER 1 TO 3 INCHES LATER THIS
EVENING INTO THE OVERNIGHT.
UPDATED WSW STATEMENT ALREADY OUT. COORD WITH APX ON THE LAKE EFFECT
SNOW ADVISORY FOR LUCE COUNTY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 546 AM EST THU JAN 1 2015
THE STACKED SFC-500MB LOW OVER S HUDSON BAY WILL WEAKEN SLIGHTLY AND
DRIFT OVER N QUEBEC OVERNIGHT TONIGHT. THIS WILL KEEP THE UPPER
GREAT LAKES IN NW FLOW ALOFT WITH SEVERAL SMALL WAVES SHIFTING
ACROSS THE AREA. A DOMINANT SFC TROUGH/COLD FRONT HOVERING NEAR THE
N MN BORDER WILL SINK ACROSS UPPER MI THROUGH THE DAY TODAY.
THIS...AND AN SHORTWAVE PUSHING ACROSS THE AREA WILL ALLOW FOR SOME
INTENSIFICATION TO SNOW SHOWERS THIS AFTERNOON. AS A RESULT...WILL
KEEP THE HIGH CHANCE POPS GOING ACROSS THE AREA AROUND 18Z...BEFORE
DIMINISHING THEM AGAIN TO ALONG THE LAKE SUPERIOR SHORELINE THIS
EVENING. 850MB TEMPS WILL FALL FROM THE MORNING READINGS OF -12 TO
-15C TO -18 TO -21C BY DAYBREAK FRIDAY.
AS FOR SPECIFICS...
LES CONTINUES ACROSS THE KEWEENAW PENINSULA...WITH A DOMINANT BAND
STRETCHING ACROSS LAKE SUPERIOR TO NEAR WHITEFISH POINT. LOOK FOR
THE EASTERN LAKE SUPERIOR BAND TO SLOWLY SINK S ONSHORE AS THE
CONVERGENT W TO SW WINDS KEEPING IT JUST OFF THE SHORE RELAX AND NW
WINDS OFF THE LAKE WIN OUT LATER THIS MORNING. THIS WILL PUSH THE
BAND OVER N LUCE COUNTY...WITH 1-3 INCHES OF SNOW FCST FOR MUCH OF
LUCE COUNTY. ANOTHER 1-3 INCHES IS EXPECTED TONIGHT WITH BETTER
CONVERGENCE NEAR WHITEFISH POINT.
WILL KEEP THE LES ADVISORY FOR SNOW AND BLOWING/DRIFTING SNOW GOING
ACROSS THE KEWEENAW PENINUSLA. EXPECT ANY DOMINANT BANDS...HIGHER
SNOW AMOUNTS...TO DRIFT AROUND AND S OF CMX...WITH NEW SNOW TODAY OF
1-3 INCHES.
EXPECT ANOTHER COLD NIGHT...WITH LOWS GENERALLY IN THE SINGLE DIGITS
BELOW AND ABOVE ZERO...WARMEST WHERE CLOUDS AND SNOW SHOWERS LINGER
ALONG LAKE SUPERIOR.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 501 AM EST THU JAN 1 2015
PERSISTENT RIDGING OVER THE EASTERN PACIFIC/NAMERICA WEST COAST
REGION WILL MAINTAIN A BROAD UPPER TROUGH OVER MUCH OF CANADA AND
THE GREAT LAKES REGION THROUGH THE FIRST WEEK OF JANUARY RESULTING
IN BELOW NORMAL TEMPERATURES AND PERIODS OF LAKE EFFECT SNOW FOR
UPPER MI.
BEGINNING FRIDAY...MODEL CONSENSUS SUGGESTS WINDS WL BACK MORE
WESTERLY AGAIN AS SFC RDG AXIS ADVANCES ACROSS AREA FROM THE NRN
PLAINS. THE GENERALLY WEAK WRLY FLOW ALONG WITH ENHANCED LOW-LVL
CONVERGENCE FROM LAND BREEZES WL HELP FOCUS GENERALLY LIGHT LAKE
EFFECT SNOW ACROSS THE KEWEENAN PENINSULA AND THE FAR ERN SHORELINE
OF THE CWA AS INVERSION BASES CRASH BLO 5KFT WITH DRY AIR NOTED
BENEATH THE INVERSION. SINCE MUCH OF THE DGZ IN STILL WITHIN THE
CLOUD LAYER...LES BANDS COULD YIELD 1-2 INCHES OF FLUFFY
ACCUMULATION DURING THE DAY. WAA CLOUDS AHEAD OF SHORTWAVE MOVING IN
FROM THE NRN PLAINS WILL LIMIT RADIATIONAL COOLING FRIDAY NIGHT BUT
TEMPS SHOULD STILL APPROACH ZERO OR MAYBE EVEN DIP BLO ZERO AT A FEW
OF THE TYPICAL COLDER LOCATIONS OVER THE WESTERN INTERIOR.
THIS WEEKEND...FOCUS IS ON PHASING/INTERACTION OF SPLIT FLOW. TWO
FEATURES WILL COME INTO PLAY...ONE WILL BE THE REMNANTS OF A CLOSED
LOW NOW PRODUCING SNOW OVER THE SW CONUS...AND THE SECOND IS A NRN
BRANCH SHORTWAVE NOW OVER THE ALEUTIAN ISLANDS WHICH IS FCST TO DIVE
SE ACROSS THE NRN ROCKIES FRI NIGHT AND THEN THROUGH THE PLAINS
STATES ON SAT. ASSOCIATED STRONG MID LEVEL WARM AIR ADVECTION AHEAD
OF THIS SHORTWAVE AND ITS ASSOC SFC LOW WILL SPREAD SNOW EAST INTO
MAINLY THE NORTHWEST HALF OF THE CWA ON SAT. WHILE THE MODELS STILL
PEG THE HEAVIEST SNOW TO OCCUR OVER LAKE SUPERIOR...WILL CONTINUE TO
SHOW SOME LIKELY POPS OVER AND AROUND THE KEWEENAW PENINSULA FOR
SATURDAY. AS THIS SNOW IS OCCURRING...THE NORTHERN SHORTWAVE WILL
CONTINUE TO DIVE SOUTHEAST AND BEGIN TO PHASE WITH THE REMNANTS OF
THE SW CONUS UPPER LOW WHICH WILL LEAD TO BOTH FEATURES EJECTING
NORTHEAST THROUGH THE LOWER GREAT LAKES REGION SATURDAY NIGHT INTO
SUNDAY. THE 00Z ECMWF...GFS AND NAM ALL TRENDING DEEPER AND FARTHER
WEST WITH RESULTING SFC LOW WHICH BLEND OF THESE MODELS SHOW A TRACK
THROUGH SRN LWR MI TO NEAR GEORGIAN BAY BY 12Z SUNDAY. THE GEM-NH
MEANWHILE AFTER SHOWING A SIMILAR TRACK TO THE 00Z ECMWF/GFS BLEND
HAS NOW TRENDED FARTHER EAST THROUGH SE LOWER MI INTO ERN ONTARIO.
IF THE LATEST GFS/ECMWF SOLNS HOLD TRUE THIS WOULD MEAN A GREATER
POTENTIAL FOR SYNOPTIC PCPN TO SPREAD INTO UPPER MI...ESPECIALLY THE
EAST HALF...ALONG WITH A GREATER POTENTIAL FOR NORTH FLOW LAKE
ENHANCED SNOW ON THE BACKSIDE OF THE SYSTEM. WILL LIKELY NEED TO
TREND POPS UPWARD ACROSS THE CWA AND ESPECIALLY ALONG LAKE SUPERIOR
ZONES WITH A GREATER POTENTIAL FOR LAKE ENHANCED SNOW SAT NIGHT INTO
SUNDAY. WINDS WILL ALSO RAMP UP WITH TIGHTER GRADIENT ON BACKSIDE OF
SYSTEM WHICH WILL ALSO RESULT IN MORE BLOWING SNOW. WILL HIGHLIGHT
POTENTIAL FOR MODERATE SNOW AND BLOWING SNOW IN HWO...ESPECIALLY
ALONG LAKE SUPERIOR AND THE EAST HALF OF THE CWA FOR SAT NIGHT INTO
SUNDAY EVENING.
LATE SUNDAY NIGHT INTO MONDAY NIGHT...WEAKENING PRES GRADIENT WILL
ALLOW WINDS TO DIMINISH ESPECIALLY OVER THE INTERIOR. WINDS WILL
ALSO BE BACKING MORE WESTERLY ESPECIALLY BY MONDAY IN ADVANCE OF
STRONG SFC HIGH PRES RDG BUILDING IN FROM THE NRN PLAINS...SO EXPECT
LES TO EVENTUALLY BECOME MORE CONFINED TO KEWEENAW AND FAR ERN
SHORELINE AREAS OF THE CWA MONDAY AFTERNOON INTO MON NIGHT. WITH
HEART OF COLDEST AIR (850 MB TEMPS OF -26 TO -28C) COMING ACROSS THE
UPPER LAKES...EXPECT VERY COLD TEMPS SUN NIGHT AND MONDAY. EXPECT
MUCH OF THE INTERIOR CWA TO FALL BLO ZERO AND WOULD NOT BE SURPRISED
TO SEE SOME WESTERN INTERIOR LOCATIONS FALL WELL INTO THE TEENS BLO
ZERO... ESPECIALLY ALONG THE WI BORDER. HIGHS MONDAY WILL REMAIN
VERY COLD WITH READINGS RANGING FROM THE SINGLE DIGITS BLO ZERO
WESTERN INTERIOR TO THE SINGLE DIGITS ABV ZERO EAST AND ALONG THE
GREAT LAKES.
TUESDAY INTO WEDNESDAY...MODELS IN REASONABLY GOOD AGREEMENT SHOWING
ANOTHER CLIPPER SHORTWAVE MOVING ACROSS THE UPPER GREAT LAKES ON
TUESDAY WITH ANOTHER REINFORCING SHOT OF ARCTIC AIR (8H TEMPS FALL
AGAIN TO -28C TO -30C) AS WINDS VEER TO THE NW. THIS WILL BRING LES
FARTHER INLAND AGAIN AFFECTING THE NRN TIER AND ERN HALF COUNTIES
FROM LATE TUE THROUGH WED. LOOK LIKE ONLY THE FAR SOUTH CENTRAL
WOULD ESCAPE THE LES. WITH SUCH A COLD ARCTIC AIRMASS FCST THE DGZ
WILL GET SQUASHED NEAR THE LAKE SFC WHICH WILL LIKELY RESULT IN
SMALLER FLAKE SIZE. THIS WILL LIMIT LES ACCUMULATION BUT AT SAME
TIME WILL BE MORE EFFECTIVE FOR REDUCING VSBY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1243 PM EST THU JAN 1 2015
COLD FRONT HAS MADE IT THROUGH KCMX AND WILL IMPACT KIWD AND KSAW
WITH A PERIOD OF SNOW SHOWERS AND BLOWING SNOW THIS AFTN. AT KIWD
AND KSAW...GENERALLY THE CIGS WILL BE MVFR INTO TONIGHT. VSBY WILL
BE IFR OR MVFR...BUT WILL BEGIN TO IMPROVE BY EARLY EVENING AS DRIER
AIR ERODES THE LAKE EFFECT SNOW SHOWERS. WILL SEE IMPROVEMENT TO VFR
LATE TONIGHT INTO FRIDAY AT KIWD AND KSAW. AT KCMX...PERSISTENT WNW-
NW FLOW OFF LK SUPERIOR WILL KEEP LAKE EFFECT SNOW SHOWERS WITH IFR
TO MVFR VSBY THROUGH THE PERIOD. STRONGEST WINDS WITH BLSN THIS
AFTN...THEN WINDS DIMINISH SIGNIFICANTLY THIS EVENING AND OVERNIGHT
TONIGHT. &&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 412 AM EST THU JAN 1 2015
A LOW OVER S HUDSON BAY WILL SHIFT INTO N QUEBEC FRIDAY MORNING. THE
TROUGH EXTENDING FROM THIS LOW ACROSS LAKE SUPERIOR WILL SLOWLY
WEAKEN. AS A RESULT...EXPECT THE GALES OF 35-40KTS TO SLOWLY
DIMINISH TOO. WHILE HEAVY FREEZING SPRAY HAS DIMINISHED THIS
MORNING...IT WILL PICK UP AGAIN OVER N LAKE SUPERIOR THIS
AFTERNOON-EVENING.
HIGH PRESSURE SINKING ACROSS MINNESOTA THIS EVENING WILL STRETCH
FROM THE GREAT LAKES THROUGH THE OHIO VALLEY ON FRIDAY...AND EXIT TO
SOUTHERN QUEBEC AND THE NEW ENGLAND STATES FRIDAY NIGHT. EXPECT A
LOW ACROSS THE DAKOTAS FRIDAY NIGHT TO CONSOLIDATE WITH AN
ADDITIONAL LOW ACROSS THE MISSISSIPPI VALLEY. THE NEW LOW WILL MOVE
NE AND DEEPEN ACROSS LOWER MICHIGAN AND LAKE HURON SATURDAY
NIGHT...AND EXIT S QUEBEC ON SUNDAY. THIS WILL BRING A TROUGH
SATURDAY NIGHT INTO SUNDAY FOR LAKE SUPERIOR. N-NW GALES OF 35 TO
NEAR 40KTS WILL AGAIN BE POSSIBLE SUNDAY INTO SUNDAY EVENING. BY
MONDAY...A RIDGE WILL SETTLE ACROSS THE N PLAINS AND UPPER
MISSISSIPPI VALLEY. HEAVY FREEZING SPRAY WILL ALSO RETURN AS A COLD
RIDGE WILL SETTLE ACROSS THE N PLAINS AND UPPER MISSISSIPPI VALLEY
MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
MIZ001-003.
LAKE EFFECT SNOW ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR MIZ006-
007-085.
LAKE SUPERIOR...
GALE WARNING UNTIL 6 PM EST THIS EVENING FOR LSZ266-267.
HEAVY FREEZING SPRAY WARNING UNTIL 3 AM EST FRIDAY FOR LSZ263-
264.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...JLA
SHORT TERM...KF
LONG TERM...VOSS
AVIATION...JLA
MARINE...KF
AREA FORECAST DISCUSSION...UPDATED
NWS MARQUETTE MI
1107 AM EST THU JAN 1 2015
.UPDATE...
ISSUED AT 1107 AM EST THU JAN 1 2015
WIDESPREAD NOAA WEATHER RADIO OUTAGE ACROSS UPR MICHIGAN CONTINUES
AT THIS HOUR DUE TO LARGER SCALE COMMS OUTAGE WITH VERIZON.
SHORTWAVE WITH WIDEPSREAD LGT SNOW IS EXITING EASTERN CWA. SFC
COLD FRONT IS FINALLY STARTING TO SINK ACROSS SOUTHERN HALF OF LK
SUPERIOR THOUGH IT IS TAKING ITS TIME IN DOING SO. LES OVER THE
KEWEENAW THIS MORNING HAS BEEN HEAVY WITH 1+ INCH PER HOUR RATES.
EXPECT LES TO BECOME LESS FOCUSED THOUGH THROUGH MIDDAY AS WINDS
SHIFT FROM THE STRONG CONVERGENT WESTERLY FLOW TO A MORE SHEARED
NORTHWEST FLOW BEHIND THE COLD FRONT. LAKE EFFECT SNOW ADVISORY
SET TO EXPIRE AT 18Z TODAY FOR NORTHERN HOUGHTON AND KEWEENAW
COUNTIES. BASED ON EXPECTED TRENDS IN LES AND WIND THAT LOOKS GOOD
AND WILL NOT MAKE ANY EXTENSIONS ATTM.
ATTN THEN TURNS TO FROPA OVER EASTERN CWA EARLY TO MID AFTN. EXPECT
DECENT CONVERGENCE BAND TO FIRST AFFECT SNOW BELTS EAST OF MARQUETTE
THEN NW FLOW LES WILL DEVELOP. RAP SOUNDINGS INDICATE INVERSIONS TO
7-8KFT WITH TEMPS AROUND -20C AT INVERSION TOP THROUGH EARLY
EVENING. MIXED LAYER WINDS 25-35 KTS WILL RESULT IN WINDY CONDITIONS
AFTER FROPA WITH BLSN/POOR VSBY. WOULD EXPECT SNOWFALL RATES BTWN
0.5-1.0 INCH PER HOUR THIS AFTN INTO THE EARLY EVENING. MUCH OF THE
CONVECTIVE LAYER IS WITHIN THE DGZ...SO SLR/S WILL BE WELL OVER
20:1.
OPTED TO ISSUE A LAKE EFFECT SNOW ADVISORY FOR ALGER...NORTHERN
SCHOOLCRAFT...AND LUCE COUNTIES THROUGH THE EVENING. SNOW AND BLSN
WILL MAKE TRAVEL DIFFICULT INTO THE EARLY EVENING WITH VSBY DOWN TO
1/4SM AT TIMES...AND SNOW AMOUNTS WILL BE BOOSTED BY HIGHER SLR/S
AND DECENTLY HIGH INVERSIONS. IN WAKE OF FROPA LATE THIS EVENING AND
OVERNIGHT TONIGHT...EXPECT DIMINISHING LES AS INVERSIONS FALL BLO
5KFT...BUT DIMINISHING WINDS AND MOST OF THE CONVECTIVE LAYER WITHIN
THE DGZ WILL STILL BOOST SNOW AMOUNTS. EXPECT SNOW TOTALS TODAY INTO
THIS EVENING OF 2 TO 4 INCHES AND ANOTHER 1 TO 3 INCHES LATER THIS
EVENING INTO THE OVERNIGHT.
UPDATED WSW STATEMENT ALREADY OUT. COORD WITH APX ON THE LAKE EFFECT
SNOW ADVISORY FOR LUCE COUNTY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 546 AM EST THU JAN 1 2015
THE STACKED SFC-500MB LOW OVER S HUDSON BAY WILL WEAKEN SLIGHTLY AND
DRIFT OVER N QUEBEC OVERNIGHT TONIGHT. THIS WILL KEEP THE UPPER
GREAT LAKES IN NW FLOW ALOFT WITH SEVERAL SMALL WAVES SHIFTING
ACROSS THE AREA. A DOMINANT SFC TROUGH/COLD FRONT HOVERING NEAR THE
N MN BORDER WILL SINK ACROSS UPPER MI THROUGH THE DAY TODAY.
THIS...AND AN SHORTWAVE PUSHING ACROSS THE AREA WILL ALLOW FOR SOME
INTENSIFICATION TO SNOW SHOWERS THIS AFTERNOON. AS A RESULT...WILL
KEEP THE HIGH CHANCE POPS GOING ACROSS THE AREA AROUND 18Z...BEFORE
DIMINISHING THEM AGAIN TO ALONG THE LAKE SUPERIOR SHORELINE THIS
EVENING. 850MB TEMPS WILL FALL FROM THE MORNING READINGS OF -12 TO
-15C TO -18 TO -21C BY DAYBREAK FRIDAY.
AS FOR SPECIFICS...
LES CONTINUES ACROSS THE KEWEENAW PENINSULA...WITH A DOMINANT BAND
STRETCHING ACROSS LAKE SUPERIOR TO NEAR WHITEFISH POINT. LOOK FOR
THE EASTERN LAKE SUPERIOR BAND TO SLOWLY SINK S ONSHORE AS THE
CONVERGENT W TO SW WINDS KEEPING IT JUST OFF THE SHORE RELAX AND NW
WINDS OFF THE LAKE WIN OUT LATER THIS MORNING. THIS WILL PUSH THE
BAND OVER N LUCE COUNTY...WITH 1-3 INCHES OF SNOW FCST FOR MUCH OF
LUCE COUNTY. ANOTHER 1-3 INCHES IS EXPECTED TONIGHT WITH BETTER
CONVERGENCE NEAR WHITEFISH POINT.
WILL KEEP THE LES ADVISORY FOR SNOW AND BLOWING/DRIFTING SNOW GOING
ACROSS THE KEWEENAW PENINUSLA. EXPECT ANY DOMINANT BANDS...HIGHER
SNOW AMOUNTS...TO DRIFT AROUND AND S OF CMX...WITH NEW SNOW TODAY OF
1-3 INCHES.
EXPECT ANOTHER COLD NIGHT...WITH LOWS GENERALLY IN THE SINGLE DIGITS
BELOW AND ABOVE ZERO...WARMEST WHERE CLOUDS AND SNOW SHOWERS LINGER
ALONG LAKE SUPERIOR.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 501 AM EST THU JAN 1 2015
PERSISTENT RIDGING OVER THE EASTERN PACIFIC/NAMERICA WEST COAST
REGION WILL MAINTAIN A BROAD UPPER TROUGH OVER MUCH OF CANADA AND
THE GREAT LAKES REGION THROUGH THE FIRST WEEK OF JANUARY RESULTING
IN BELOW NORMAL TEMPERATURES AND PERIODS OF LAKE EFFECT SNOW FOR
UPPER MI.
BEGINNING FRIDAY...MODEL CONSENSUS SUGGESTS WINDS WL BACK MORE
WESTERLY AGAIN AS SFC RDG AXIS ADVANCES ACROSS AREA FROM THE NRN
PLAINS. THE GENERALLY WEAK WRLY FLOW ALONG WITH ENHANCED LOW-LVL
CONVERGENCE FROM LAND BREEZES WL HELP FOCUS GENERALLY LIGHT LAKE
EFFECT SNOW ACROSS THE KEWEENAN PENINSULA AND THE FAR ERN SHORELINE
OF THE CWA AS INVERSION BASES CRASH BLO 5KFT WITH DRY AIR NOTED
BENEATH THE INVERSION. SINCE MUCH OF THE DGZ IN STILL WITHIN THE
CLOUD LAYER...LES BANDS COULD YIELD 1-2 INCHES OF FLUFFY
ACCUMULATION DURING THE DAY. WAA CLOUDS AHEAD OF SHORTWAVE MOVING IN
FROM THE NRN PLAINS WILL LIMIT RADIATIONAL COOLING FRIDAY NIGHT BUT
TEMPS SHOULD STILL APPROACH ZERO OR MAYBE EVEN DIP BLO ZERO AT A FEW
OF THE TYPICAL COLDER LOCATIONS OVER THE WESTERN INTERIOR.
THIS WEEKEND...FOCUS IS ON PHASING/INTERACTION OF SPLIT FLOW. TWO
FEATURES WILL COME INTO PLAY...ONE WILL BE THE REMNANTS OF A CLOSED
LOW NOW PRODUCING SNOW OVER THE SW CONUS...AND THE SECOND IS A NRN
BRANCH SHORTWAVE NOW OVER THE ALEUTIAN ISLANDS WHICH IS FCST TO DIVE
SE ACROSS THE NRN ROCKIES FRI NIGHT AND THEN THROUGH THE PLAINS
STATES ON SAT. ASSOCIATED STRONG MID LEVEL WARM AIR ADVECTION AHEAD
OF THIS SHORTWAVE AND ITS ASSOC SFC LOW WILL SPREAD SNOW EAST INTO
MAINLY THE NORTHWEST HALF OF THE CWA ON SAT. WHILE THE MODELS STILL
PEG THE HEAVIEST SNOW TO OCCUR OVER LAKE SUPERIOR...WILL CONTINUE TO
SHOW SOME LIKELY POPS OVER AND AROUND THE KEWEENAW PENINSULA FOR
SATURDAY. AS THIS SNOW IS OCCURRING...THE NORTHERN SHORTWAVE WILL
CONTINUE TO DIVE SOUTHEAST AND BEGIN TO PHASE WITH THE REMNANTS OF
THE SW CONUS UPPER LOW WHICH WILL LEAD TO BOTH FEATURES EJECTING
NORTHEAST THROUGH THE LOWER GREAT LAKES REGION SATURDAY NIGHT INTO
SUNDAY. THE 00Z ECMWF...GFS AND NAM ALL TRENDING DEEPER AND FARTHER
WEST WITH RESULTING SFC LOW WHICH BLEND OF THESE MODELS SHOW A TRACK
THROUGH SRN LWR MI TO NEAR GEORGIAN BAY BY 12Z SUNDAY. THE GEM-NH
MEANWHILE AFTER SHOWING A SIMILAR TRACK TO THE 00Z ECMWF/GFS BLEND
HAS NOW TRENDED FARTHER EAST THROUGH SE LOWER MI INTO ERN ONTARIO.
IF THE LATEST GFS/ECMWF SOLNS HOLD TRUE THIS WOULD MEAN A GREATER
POTENTIAL FOR SYNOPTIC PCPN TO SPREAD INTO UPPER MI...ESPECIALLY THE
EAST HALF...ALONG WITH A GREATER POTENTIAL FOR NORTH FLOW LAKE
ENHANCED SNOW ON THE BACKSIDE OF THE SYSTEM. WILL LIKELY NEED TO
TREND POPS UPWARD ACROSS THE CWA AND ESPECIALLY ALONG LAKE SUPERIOR
ZONES WITH A GREATER POTENTIAL FOR LAKE ENHANCED SNOW SAT NIGHT INTO
SUNDAY. WINDS WILL ALSO RAMP UP WITH TIGHTER GRADIENT ON BACKSIDE OF
SYSTEM WHICH WILL ALSO RESULT IN MORE BLOWING SNOW. WILL HIGHLIGHT
POTENTIAL FOR MODERATE SNOW AND BLOWING SNOW IN HWO...ESPECIALLY
ALONG LAKE SUPERIOR AND THE EAST HALF OF THE CWA FOR SAT NIGHT INTO
SUNDAY EVENING.
LATE SUNDAY NIGHT INTO MONDAY NIGHT...WEAKENING PRES GRADIENT WILL
ALLOW WINDS TO DIMINISH ESPECIALLY OVER THE INTERIOR. WINDS WILL
ALSO BE BACKING MORE WESTERLY ESPECIALLY BY MONDAY IN ADVANCE OF
STRONG SFC HIGH PRES RDG BUILDING IN FROM THE NRN PLAINS...SO EXPECT
LES TO EVENTUALLY BECOME MORE CONFINED TO KEWEENAW AND FAR ERN
SHORELINE AREAS OF THE CWA MONDAY AFTERNOON INTO MON NIGHT. WITH
HEART OF COLDEST AIR (850 MB TEMPS OF -26 TO -28C) COMING ACROSS THE
UPPER LAKES...EXPECT VERY COLD TEMPS SUN NIGHT AND MONDAY. EXPECT
MUCH OF THE INTERIOR CWA TO FALL BLO ZERO AND WOULD NOT BE SURPRISED
TO SEE SOME WESTERN INTERIOR LOCATIONS FALL WELL INTO THE TEENS BLO
ZERO... ESPECIALLY ALONG THE WI BORDER. HIGHS MONDAY WILL REMAIN
VERY COLD WITH READINGS RANGING FROM THE SINGLE DIGITS BLO ZERO
WESTERN INTERIOR TO THE SINGLE DIGITS ABV ZERO EAST AND ALONG THE
GREAT LAKES.
TUESDAY INTO WEDNESDAY...MODELS IN REASONABLY GOOD AGREEMENT SHOWING
ANOTHER CLIPPER SHORTWAVE MOVING ACROSS THE UPPER GREAT LAKES ON
TUESDAY WITH ANOTHER REINFORCING SHOT OF ARCTIC AIR (8H TEMPS FALL
AGAIN TO -28C TO -30C) AS WINDS VEER TO THE NW. THIS WILL BRING LES
FARTHER INLAND AGAIN AFFECTING THE NRN TIER AND ERN HALF COUNTIES
FROM LATE TUE THROUGH WED. LOOK LIKE ONLY THE FAR SOUTH CENTRAL
WOULD ESCAPE THE LES. WITH SUCH A COLD ARCTIC AIRMASS FCST THE DGZ
WILL GET SQUASHED NEAR THE LAKE SFC WHICH WILL LIKELY RESULT IN
SMALLER FLAKE SIZE. THIS WILL LIMIT LES ACCUMULATION BUT AT SAME
TIME WILL BE MORE EFFECTIVE FOR REDUCING VSBY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 739 AM EST THU JAN 1 2015
A COLD FRONT ACROSS THE AREA WILL HELP KEEP SNOW SHOWERS GOING AT
ALL 3 SITES. REDUCED VIS DOWN TO LIFR AND IFR WILL REMAIN AT IWD UP
THROUGH CMX...GIVEN THE FAVORABLE W WINDS THAT WILL BE BECOME MORE
NORTHWESTERLY BY LATE MORNING/EARLY AFTERNOON. REMAINED MOST
PESSIMISTIC FOR CMX AS SOUNDINGS INDICATE LOW LEVEL MOISTURE TRAPPED
BELOW 5KFT THROUGH THE END OF THE PERIOD. BLSN WILL SLOWLY COME TO
AN END TODAY AS THE STRONG LOW RESPONSIBLE FOR THE STRONG WINDS
DIMINISHES AND EXITS HUDSON BAY INTO QUEBEC. LOOK FOR VFR CEILINGS
TO RETURN BEHIND THE SFC TROUGH BY 01Z FRIDAY IF NOT EARLIER...AND
END BY AROUND 05Z /OR POSSIBLY A BIT LATER/ AT IWD AS SFC WINDS
BECOME MORE OUT OF THE W...WITH THE MAIN BANDS OF LAKE EFFECT SNOW
SHIFTING N OF THE SITE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 412 AM EST THU JAN 1 2015
A LOW OVER S HUDSON BAY WILL SHIFT INTO N QUEBEC FRIDAY MORNING. THE
TROUGH EXTENDING FROM THIS LOW ACROSS LAKE SUPERIOR WILL SLOWLY
WEAKEN. AS A RESULT...EXPECT THE GALES OF 35-40KTS TO SLOWLY
DIMINISH TOO. WHILE HEAVY FREEZING SPRAY HAS DIMINISHED THIS
MORNING...IT WILL PICK UP AGAIN OVER N LAKE SUPERIOR THIS
AFTERNOON-EVENING.
HIGH PRESSURE SINKING ACROSS MINNESOTA THIS EVENING WILL STRETCH
FROM THE GREAT LAKES THROUGH THE OHIO VALLEY ON FRIDAY...AND EXIT TO
SOUTHERN QUEBEC AND THE NEW ENGLAND STATES FRIDAY NIGHT. EXPECT A
LOW ACROSS THE DAKOTAS FRIDAY NIGHT TO CONSOLIDATE WITH AN
ADDITIONAL LOW ACROSS THE MISSISSIPPI VALLEY. THE NEW LOW WILL MOVE
NE AND DEEPEN ACROSS LOWER MICHIGAN AND LAKE HURON SATURDAY
NIGHT...AND EXIT S QUEBEC ON SUNDAY. THIS WILL BRING A TROUGH
SATURDAY NIGHT INTO SUNDAY FOR LAKE SUPERIOR. N-NW GALES OF 35 TO
NEAR 40KTS WILL AGAIN BE POSSIBLE SUNDAY INTO SUNDAY EVENING. BY
MONDAY...A RIDGE WILL SETTLE ACROSS THE N PLAINS AND UPPER
MISSISSIPPI VALLEY. HEAVY FREEZING SPRAY WILL ALSO RETURN AS A COLD
RIDGE WILL SETTLE ACROSS THE N PLAINS AND UPPER MISSISSIPPI VALLEY
MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
MIZ001-003.
LAKE EFFECT SNOW ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR MIZ006-
007-085.
LAKE SUPERIOR...
GALE WARNING UNTIL 6 PM EST THIS EVENING FOR LSZ266-267.
HEAVY FREEZING SPRAY WARNING UNTIL 3 AM EST FRIDAY FOR LSZ263-
264.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...JLA
SHORT TERM...KF
LONG TERM...VOSS
AVIATION...KF
MARINE...KF
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
423 PM CST Thu Jan 1 2015
.SHORT TERM: (Tonight and Friday)
Issued at 338 PM CST Thu Jan 1 2015
The area is sandwiched between high pressure to the south and a trof
of low pressure up across the Upper Midwest. Southwest flow is the
result and temperatures have rebounded into the mid and upper 30s
across the entire area. With abundant cloud cover and weak
southwest flow continuing tonight, expect that lows tonight will be
several degrees warmer tonight than they were last night. Most
areas should get back down below freezing again, but think temps
should stay mostly in the upper 20s to low 30s across the majority
of the area (with the exception of northern MO and west central IL
where clouds should be thinner allowing for more radiational
cooling). NAM, GFS, and RAP develop some weak moisture convergence
on the 850mb baroclinic zone Friday morning just south of the STL
Metro area. While the GFS says dry, the NAM and to a lesser extent
the RAP do print out a little very light QPF. 4km NCEP and NSSL WRF
models also show very light QPF Friday morning, and light simulated
radar returns as well. Therefore, feel there`s enough signal to
bump up PoPs slightly for Friday morning along and southeast of
I-44/US-50. P-types will likely start out as a little rain/sleet
mix and where temps are below freezing there could be a bit of
glaze, but amounts look very light. Precip should turn quickly to
light rain or just sprinkles with a couple of hours of sunrise, and
highs look to be in the mid to upper 30s across the area on Friday.
Carney
.LONG TERM: (Friday Night through Next Thursday)
Issued at 421 PM CST Thu Jan 1 2015
Models are coming into better consensus with the storm system for
Friday night and Saturday. GFS and NAM continue to warm up bit by
bit. Most recent partial thickness forecasts show all critical
thickness lines for rain/snow well up into northern
Missouri/southern Iowa by the time the precipitation starts on
Friday night. Forecast soundings also have little or no cold layer
in the low levels indicating that sleet is becoming less and less
likely. So have more or less confined any chances of sleet to
northern zones Friday evening, changing over to all rain and
freezing rain where surface temperatures dictate. Think any
accumulations of freezing rain will be minor due to warm ground
temperatures and diabatic warming due to latent heat release.
Temperatures should warm above freezing after sunrise on Saturday
morning at any rate which should stop any ice accumulation. Think
the greatest amount of accumulation will be over northern MO and
west central IL and amounts should be between a trace and 0.05 inch.
Dry slot should wrap around into the storm on Saturday afternoon
which will likely make the rain slack off and even end across
southern portions of the area. Cold front moves through Saturday
evening with the tail end of the def-zone clipping our area.
Guidance seems to want to keep the majority of the QPF out of our
area over northwest Missouri and southern Iowa. However, it looks
like our northwest counties could get clipped with an inch or two of
snow before all the shouting is over.
Remainder of the forecast looks cold and dry as a longwave trof
deepens over the eastern CONUS. This will allow a couple of Arctic
air intrusions into the lower 48...one on Sunday and Monday behind
the weekend storm, and another midweek. This should keep
temperatures well below normal through the end of the forecast
period.
Carney
&&
.AVIATION: (For the 18z TAFs through 18z Friday Afternoon)
Issued at 1142 AM CST Thu Jan 1 2015
General thickening and lowering cloud deck trend is expected over
the next 30 hours as southerly flow continues in the lower
atmosphere. Have not introduced precipitation into the forecast at
this time as the majority is forecast to remain south of the
terminals. That being said, a few models are showing some light
QPF edging toward the St. Louis Metro terminals early tomorrow
morning. Depending on surface temperature this could be DZ or
FZDZ if it occurs. Am not confident enough in this occuring to
include into the forecast at this time. Light southwest to south
wind expected to continue.
Specifics for KSTL:
Only concern is for light drizzle or freezing drizzle early Friday
morning. Confidence too low at this point to include in the
forecast - but something to keep an eye on. Otherwise, general
thickening and lowering cloud trend is forecast with a light
southwest wind.
CVKING
&&
.PRELIMINARY POINT TEMPS/POPS:
Saint Louis 29 38 34 41 / 10 20 80 90
Quincy 23 34 29 35 / 5 5 50 80
Columbia 27 37 31 38 / 10 10 80 80
Jefferson City 28 38 32 40 / 10 10 80 80
Salem 29 37 33 43 / 10 10 80 90
Farmington 30 38 33 43 / 20 20 80 90
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
339 PM CST Thu Jan 1 2015
.SHORT TERM: (Tonight and Friday)
Issued at 338 PM CST Thu Jan 1 2015
The area is sandwiched between high pressure to the south and a trof
of low pressure up across the Upper Midwest. Southwest flow is the
result and temperatures have rebounded into the mid and upper 30s
across the entire area. With abundant cloud cover and weak
southwest flow continuing tonight, expect that lows tonight will be
several degrees warmer tonight than they were last night. Most
areas should get back down below freezing again, but think temps
should stay mostly in the upper 20s to low 30s across the majority
of the area (with the exception of northern MO and west central IL
where clouds should be thinner allowing for more radiational
cooling). NAM, GFS, and RAP develop some weak moisture convergence
on the 850mb baroclinic zone Friday morning just south of the STL
Metro area. While the GFS says dry, the NAM and to a lesser extent
the RAP do print out a little very light QPF. 4km NCEP and NSSL WRF
models also show very light QPF Friday morning, and light simulated
radar returns as well. Therefore, feel there`s enough signal to
bump up PoPs slightly for Friday morning along and southeast of
I-44/US-50. P-types will likely start out as a little rain/sleet
mix and where temps are below freezing there could be a bit of
glaze, but amounts look very light. Precip should turn quickly to
light rain or just sprinkles with a couple of hours of sunrise, and
highs look to be in the mid to upper 30s across the area on Friday.
Carney
.LONG TERM: (Tonight through Wednesday)
Issued at 345 AM CST Thu Jan 1 2015
(Tonight through Saturday)
The approaching system to impact the region thru the weekend
continues to be the forecast focus.
The upper low, currently over the swrn U.S., shud have been well
sampled last evening which increases confidence in the latest mdl
guidance. However, with differences among mdl solns, that confidence
is reduced. A quick note that the 00z GFS soln has dewpoint
initialization problems once again. This time, it appears the bad
data is washed out within 18 to 24 hrs, at least in this region.
Otherwise, mdls are in good agreement thru 12z Fri. However,
differences quickly emerge beyond this time. The NAM/local WRF are a
fast soln, with the GEM being a slow soln and the ECMWF/GFS/GEFS
between these extremes tho still not in agreement with one another.
Have trended twd the ECMWF/GFS/GEFS solns thru this period. These
solns seem most logical given the timing and placement of the
upstream jet.
Overall, main forecast changes are precip onset quicker as well as
warmer temps. Mdls have a more shallow cold air wedge N of the
wrmfnt as the system approaches. Have therefore trended p-types twd
a RA vs. FZRA and reduced mention of IP. However, the nwd
advancement of the wrmfnt slows greatly Fri night into Sat. Have
kept mention of IP across nrn portions of the CWA during this time
where the cold air shud be deep enuf for precip to refreeze. The
warm air aloft is also colder during this time so cold air shud not
need to be as deep.
The ECMWF/GFS/GEFS have shifted the def zone precip further to the
NW on Sat night. The best chances for SN now appear to stretch from
KC to ern IA, just to the NW of the CWA. However, nrn and ern
portions of the CWA will likely see some SN as the def zone pulls
newd thru the region. Uncertainty with the placement of this precip
still exists and will continue until mdl solns are more consistent.
(Sunday through Wednesday)
Precip will have ended by the beginning of this period and
therefore, focus turns to temps thru the extd.
The ECMWF/GFS/GEFS remain in fairly good agreement thru the end of
the forecast period. Have therefore trended the forecast twd a
compromise thru the extd.
Cannot rule out a chance for precip sometime Mon night into Tues
and/or Wed. Since these systems are clippers, determining the
location of precip as the s/w drops thru the region will be
difficult and have low confidence in any one soln. Have kept PoPs
low for now.
Tilly
&&
.AVIATION: (For the 18z TAFs through 18z Friday Afternoon)
Issued at 1142 AM CST Thu Jan 1 2015
General thickening and lowering cloud deck trend is expected over
the next 30 hours as southerly flow continues in the lower
atmosphere. Have not introduced precipitation into the forecast at
this time as the majority is forecast to remain south of the
terminals. That being said, a few models are showing some light
QPF edging toward the St. Louis Metro terminals early tomorrow
morning. Depending on surface temperature this could be DZ or
FZDZ if it occurs. Am not confident enough in this occuring to
include into the forecast at this time. Light southwest to south
wind expected to continue.
Specifics for KSTL:
Only concern is for light drizzle or freezing drizzle early Friday
morning. Confidence too low at this point to include in the
forecast - but something to keep an eye on. Otherwise, general
thickening and lowering cloud trend is forecast with a light
southwest wind.
CVKING
&&
.PRELIMINARY POINT TEMPS/POPS:
Saint Louis 29 38 34 41 / 10 20 80 90
Quincy 23 34 29 35 / 5 5 50 80
Columbia 27 37 31 38 / 10 10 80 80
Jefferson City 28 38 32 40 / 10 10 80 80
Salem 29 37 33 43 / 10 10 80 90
Farmington 30 38 33 43 / 20 20 80 90
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1140 AM EST THU JAN 1 2015
.SYNOPSIS...
HIGH PRESSURE ACROSS THE SOUTHEASTERN U.S. WILL MOVE OFFSHORE
FRIDAY. RAIN CHANCES WILL INCREASE FRIDAY...WITH PERIODS OF RAIN
EXPECTED FRIDAY NIGHT AND SATURDAY AS A WARM FRONT APPROACHES. A
STRONG COLD FRONT MAY BRING A FEW THUNDERSTORMS SUNDAY AFTERNOON AND
NIGHT. CLEAR AND COLD CONDITIONS WILL OVERSPREAD THE CAROLINAS
MONDAY THROUGH WEDNESDAY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM THURSDAY...VERY FEW CHANGES WERE NEEDED TO THE
FORECAST. SKIES ARE CLEAR WITH SATELLITE IMAGERY INDICATING CIRRUS
NOW APPROACHING THE SOUTHERN APPALACHIANS WILL BEGIN TO REACH THE
COAST THIS AFTERNOON. 12Z SOUNDINGS FROM MHX AND GSO LOOKED MUCH
LIKE THE 06Z MODELS INDICATED. BASED ON RECENT HRRR AND RUC
MODELS I HAVE INCREASED ONSHORE WINDS BY A FEW MPH THIS AFTERNOON
NEAR THE BEACHES WITH A WEAK SEABREEZE CIRCULATION. THIS ONSHORE
WIND WILL ALSO UNFORTUNATELY DRAG SOME PRETTY CHILLY AIR BACK IN
FROM THE OCEAN DURING THE MID-AFTERNOON HOURS.
INLAND HIGHS SHOULD RANGE FROM 54-57...WITH THE BEACHES RUNNING A
FEW DEGREES COOLER.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...FOR THE MEDIUM AND LONG RANGE PACKAGE WILL
FAVOR THE GFS/ECMWF SOLUTION FOR THE PERIOD. H5 CUT OFF LOW ACROSS
THE SW RESULTS IN SPLIT FLOW ACROSS THE CONUS WITH RIDGING ACROSS
THE GULF COAST AND SE THROUGH THE PERIOD. EXPECT CLOUDS TO STREAM
INTO THE AREA AND THICKEN ON FRIDAY WITH PRECIPITATION CHANCES
INCREASING AS GULF MOISTURE BECOMES AVAILABLE. BELIEVE THE FIRST
HALF OF THE DAY SHOULD REMAIN DRY WITH CHANCE POPS DURING THE
LATER HALF OF FRIDAY. MAIN BULK OF PRECIPITATION STAYS TO OUR WEST
AS H5 LOW AND SURFACE LOW TRACK TO THE NE . H8 LOW LEVEL JET
INCREASE TO 30-35 KNOTS ACROSS THE REGION INCREASING LOW LEVEL
INSTABILITY AS EXIT REGION OF JET MOVES ACROSS THE CWA LATE
SATURDAY. WITH H5 SW FLOW WILL LOOK FOR MODERATING TEMPERATURES
THROUGH THE PERIOD. MOST OF THE PRECIPITATION WILL BE ON THE LIGHT
SIDE FRIDAY INTO SATURDAY WITH BREAKS THROUGHOUT THE PERIOD. WILL
STAY CLOSE TO GUIDANCE TEMPS FOR THE PERIOD.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 300 AM THURSDAY...EXPECT SUNDAY TO BE THE MORE ACTIVE DAY
OF THE WEEKEND WITH THE SPLIT FLOW PATTERN ACROSS THE US PHASING
IN ACROSS THE EASTERN HALF OF THE COUNTRY DURING THIS PERIOD AS H5
LOW AND SURFACE LOW MOVE INTO THE GREAT LAKES WITH DEVELOPING
TROUGH ACROSS THE CENTRAL U.S. H5 SW FLOW ACROSS THE SE WITH ABOVE
NORMAL TEMPERATURES EXPECTED ON SUNDAY AND THE GREATER RISK OF
RAIN AND POSSIBLE THUNDERSTORMS AHEAD OF ADVANCING COLD FRONT
MOVING INTO THE CAROLINAS. MODELS PEG THE FRONT ACROSS THE CWA
DURING LATE AFTERNOON INTO THE EARLY EVENING WITH BEST DYNAMICS AT
THIS TIME TO SUPPORT SOME ELEVATED CONVECTION AIDED BY DEPARTED H8
JET STREAK ACROSS THE REGION. WILL MAKE MENTION OF SLIGHT CHANCE
OF TSTM IN THE GRIDS FOR THE AFTERNOON/EVENING PERIOD. AS THE
FRONT EXITS THE COAST LATE SUNDAY AND H5 FLOW DAMPENS OUT BECOMING
MORE ZONAL FOR NEXT WEEK EXPECT SEASONABLE TO SLIGHTLY ABOVE CLIMO
TEMPS FOR NEXT WEEK FOR THE HIGHS AND CLEAR BUT COOLER OVERNIGHT
LOWS BELOW SLIGHTLY BELOW CLIMO AS CANADIAN HIGH PRESSURE BUILD IN
FORM THE WEST BUT STAYS TO OUR NORTH. GFS SEEMS TO WANT TO
DEVELOP A SURFACE LOW OFF THE SE COAST LATE IN THE PERIOD BUT ITS
FURTHER EAST THEN THE 31/00Z RUN OF LAST NIGHT AND WEAKER. THE
ECMWF HAS NOT HAD THIS FEATURE DURING THE PAST FEW RUNS SO WITH
HE GFS TRENDING WEAKER AND FURTHER EAST IT WILL NOT IMPACT THE
REGION TUESDAY INTO WEDNESDAY. H5 FLOW BECOMES MORE NW TOWARDS THE
END OF THE PERIOD AND WE START TO SEE COOLER TEMPS ARRIVE BY
THURSDAY INTO FRIDAY.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 18Z...WEAK HIGH PRESSURE WILL SHIFT OFFSHORE TODAY...WITH
MAINLY WEAK SOUTHWESTERLY FLOW THIS AFTERNOON. THIS
EVENING...INCREASING CLOUDINESS AS THE NEXT SLUG OF MOISTURE RIDES
UP FROM THE SOUTHWEST. THE NAM IS A BIT MORE PESSIMISTIC THAN THE
GFS...WITH RAIN BEGINNING BEFORE DAYBREAK IN SPOTS. WILL GO WITH
MORE OF A BLEND DUE TO THE WEAK ISENTROPIC NATURE OF THINGS. WILL
INTRODUCE PRECIP FRIDAY BY MID TO LATE MORNING. CEILINGS AND
VISIBILITIES WILL LIKELY REMAIN VFR THROUGH THE END OF THE FORECAST
PERIOD...HOWEVER THINGS WILL DETERIORATE SHORTLY AFTER THAT.
EXTENDED OUTLOOK...VFR INTO FRI. CHANCE OF RAIN AND MVFR/TEMPO IFR
CONDITIONS FRI NIGHT THROUGH SUN. BECOMING VFR LATE SUN. VFR MON AND
TUE.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM THURSDAY...VERY FEW CHANGES WERE NEEDED TO THE
FORECAST. BASED ON LATEST HRRR AND RUC MODELS I HAVE BUMPED UP WIND
SPEEDS BETWEEN 1-5 PM BY A FEW KNOTS NEAR THE BEACHES WITH A WEAK
SEABREEZE CIRCULATION. WIND SPEEDS STILL WILL REMAIN LESS THAN 10
KT. SEAS ARE BARELY 1-2 FEET AND SHOULD CHANGE LITTLE THROUGH THE
DAY. E THE RULE TONIGHT. SEAS WILL BE 2 FT OR LESS THROUGH THE
PERIOD.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...WEAK BUBBLE HIGH ACROSS THE COASTAL WATERS
DURING FRIDAY WILL RESULT IN RELATIVELY LIGHT WINDS AND SEAS LESS
THAN 10 KT WITH SEAS 1-2 FEET NEAR SHORE AND 2-3 OFFSHORE.
SATURDAY THE WINDS INCREASE FROM THE EAST AS COASTAL TROUGH
OFFSHORE INTERACTS WITH THE FRONT TO UR WEST IN TIGHTENING THE
PRESSURE GRADIENT ACROSS THE WATERS. BY MID DAY SATURDAY EAST
WINDS OF 10-15 KTS NEAR SHORE AND 15-20 KTS OFFSHORE WILL START TO
BUILD SEAS TO 2-4 NEAR SHORE AND 3-5 FEET OFFSHORE APPROACHING 6
FEET IN THE OUTER MARINE ZONES BY LATE SATURDAY.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 300 AM THURSDAY...SMALL CRAFT ADVISORY CONDITIONS ARE
POSSIBLE SUNDAY AND MAYBE MONDAY AS FRONT APPROACHES THE COASTAL
WATERS AND WINDS VEER TO THE SW AND INCREASE TO 15-20 KTS NEAR
SHORE AND 20 TO 25 KTS OFFSHORE WITH BUILDING SEAS. WITH H8 JET
STREAK EXITING THE AREA AND THREAT OF ISOLATED THUNDERSTORMS SEAS
SHOULD REACT AND BUILD QUICKLY ON SUNDAY AND BE CHOPPY. FRONT
PASSES ACROSS THE COASTAL WATERS LATE SUNDAY NIGHT EARLY MONDAY
AND WINDS BECOME NORTHWEST STILL RATHER STRONG AT 15-20 KTS WILL
KEEP SEAS UP FOR THE EARLY PART OF MONDAY BEFORE SUBSIDING A BIT
BY AFTERNOON BUT NOT BY MUCH.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...RJD/TRA
SHORT TERM...MAC
LONG TERM...MAC
AVIATION...43
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
324 PM CST THU JAN 1 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 324 PM CST THU JAN 1 2015
FORECAST CHALLENGES FOR SHORT TERM WILL BE OVERNIGHT LOWS TONIGHT
FOLLOWED BY EVOLUTION OF A SNOW PRODUCING CLIPPER SYSTEM TOMORROW
NIGHT...TO INCLUDE SNOW AMOUNTS AND INTENSITIES MAINLY AFTER
MIDNIGHT INTO SUNDAY MORNING. THE ECMWF/GEM/GFS HAVE THE BEST
AGREEMENT FOR THIS SYSTEM AND WILL USE A ECMWF/GFS BLEND.
TONIGHT...CURRENT VIS SHOWS SOME CLEARING OVER PORTIONS OF THE
DEVILS LAKE BASIN AS WELL AS FRESH SNOW ACROSS PORTIONS OF
NORTHEAST ND AND THE NORTHERN RED RIVER VALLEY. MID CLOUD UPSTREAM
IN THE NW FLOW MAY ADVECT BACK INTO THE FAR NW AND TIMING OF THIS
CLOUD COVER WILL BE CRITICAL ON OVERNIGHT LOWS...AS WELL AS ONSET
OF RETURN FLOW ACROSS EASTERN ND BY MIDNIGHT. A WEAK LOW WILL
SKIRT THE NORTH TONIGHT...AND BRINGS SOME LIGHT SNOW TO THE
NORTHERN FORECAST AREA FROM MIDNIGHT THROUGH MID MORNING TOMORROW.
VERY LIGHT ACCUMULATIONS ARE EXPECTED. MEANWHILE...A CLIPPER WILL
DEVELOP ON THE LEE SIDE OF THE NORTHERN/CANADIAN ROCKIES. EXPECT
COLDEST TEMPERATURES OVER THE NORTHEASTERN FCST AREA ESPECIALLY
THE NORTHERN VALLEY WHERE SKIES SHOULD REMAIN CLEAR ENOUGH TO GET
EARLY LOWS BEFORE WARM ADVECTION BEGINS BY MORNING.
TOMORROW...CLIPPER SYSTEM BEGINS TO DROP INTO MT AND MOVE
EAST...NEARING THE ND STATE LINE AROUND 00Z. A WARM FRONTAL BNDRY
WILL LIFT NORTH AND HELP GENERATE SNOW MAINLY IN W AND CNTRL ND
ALONG THE INTL BORDER. MODELS DIFFER ON EASTWARD EXTEND OF
SNOW...WITH GEM/ECMWF/GFS REACHING THE NORTHERN VALLEY BY 00Z AND
THE NAM SLOWER AND DRIER IN THE AFTN HOURS. FOR THIS PERIOD
ONLY...LIKE THE SLOWER NAM AS IT WILL TAKE A WHILE TO SATURATE THE
COLUMN GIVEN THE DRY AIRMASS IN PLACE FROM NE FLOW TODAY AND
TONIGHT. SHOULD SEE SOME DEVELOPMENT IN NORTHEASTERN ND IN THE 21Z
TO 00Z SATURDAY TIME FRAME.
TOMORROW NIGHT...WELL ADVERTISED CLIPPER SYSTEM WILL MOVE ACROSS
CWA...HOWEVER EXACT TRACK OF SFC LOW STILL IN QUESTION. GENERALLY
THE SLIGHTLY SOUTHWARD GFS/ECMWF/GFS SOLUTION IS PREFERRED OVER
THE MORE NORTHERN NAM SOLUTION...ALTHOUGH ALL MODELS TRENDED NORTH
SINCE YESTERDAYS RUN. AN RIGHT ENTRANCE REGION WILL SET UP
GENERALLY OVER SOUTHEASTERN MANITOBA AS THE SFC LOW MOVES INTO
EASTERN DAKOTAS AFT MIDNIGHT SAT NIGHT. MODELS ARE SHOWING DECENT
ISENTROPIC LIFT AS WELL AS H300 TO H500 Q VECTOR CONVERGENCE OVER
PORTIONS OF NORTHEASTERN ND AND NORTHWEST MN. THESE INGREDIENTS
ARE BEST OVERLAPPED IN SOUTHEASTERN MB AND PORTIONS OF THE NE
CWA AND SHOULD HAVE SUFFICIENT ASCENT TO CREATE BANDED SNOWFALL.
DID INCREASE GFS-BASED SNOW RATIOS TO AROUND 25:1 IN THE FAR NE.
EXPECT TO SEE SOME AREAS OF HEAVY SNOWFALL ACROSS THE NORTH...BUT
STILL ENOUGH UNCERTAINTY ON EXACT COUNTIES TO HOLD OFF ON
UPGRADING HEADLINES TO A HEAVY SNOW WARNING AS MAIN IMPACTS WILL
BE IN THE THIRD PERIOD. IN GENERAL...OVER SIX INCHES OF SNOW IS
QUITE POSSIBLE IN COUNTIES ALONG THE INTERNATIONAL BORDER...WITH
HEAVIER SNOWFALL BEGINNING AFTER MIDNIGHT AND INCREASING THROUGH
MID MORNING SATURDAY.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 324 PM CST THU JAN 1 2015
SATURDAY...CLIPPER WILL TRACK INTO THE LOWER GREAT LAKES AND WRAP
AROUND SNOWFALL SHOULD EXIT EASTERN ZONES BY OOZ SUNDAY. MOST
SIGNIFICANT ISSUE SATURDAY WILL BE INCREASING WINDS DUE TO TIGHT
PRESSURE GRADIENT FROM DEPARTING LOW AND STRONG COLD ADVECTION AS
ARCTIC AIR POURS IN TO REGION. THIS WILL GENERATE AREAS OF BLOWING
SNOW IN NORTHEASTERN ND BY NOONTIME SATURDAY. THE SOUTHWARD EXTEND
OF ANY BLOWING SNOW WILL BE DEPENDENT ON PLACEMENT OF ANY NEW
SNOW...WITH MOST FRESH SNOW FALLING NORTH OF THE HWY 200 CORRIDOR
AND THE HEAVIEST NORTH OF HWY 2. AGAIN...STILL SOME UNCERTAINTY ON
THE TRACK OF THE SFC LOW AND PLACEMENT OF SNOWFALL...BUT BLOWING
SNOW COULD BE AN ISSUE IN AT LEAST NE ND ON SAT AM.
SATURDAY NIGHT THROUGH SUNDAY...WINDS WILL TAPER DOWN IN THE
SOUTHERN VALLEY BY MID TO LATE SATURDAY EVENING. YET ANOTHER
ARCTIC AIR MASS WILL THEN MOVE INTO THE REGION AND CREATE SEVERAL
DAYS OF SUB ZERO TEMPERATURES FOR MUCH OF THE FORECAST AREA...WITH
SUNDAY HIGHS STRUGGLING TO MAKE IT OUT OF THE TEENS BELOW ZERO ON
SUNDAY IN THE NORTH.
SUNDAY NIGHT THROUGH THURSDAY...THE WORD FOR THE PERIOD IS COLD.
ARCTIC HIGH PRESSURE REMAINS IN PLACE OVER THE NORTHERN
PLAINS...WITH A POSSIBLE WEAK SYSTEM MOVING THROUGH MONDAY NIGHT.
THE GFS AND ECMWF BRING A WEAK REINFORCING SHORTWAVE THROUGH EARLY
IN THE WEEK...WITH A LOW PRESSURE CENTER MOVING JUST TO THE SOUTH OF
THE CWA AND PUTTING THE SOUTHERN COUNTIES IN THE GOOD DEFORMATION
ZONE. THE GEM ON THE OTHER HAND...IS DRY AND NAEFS PRECIP
PROBABILITIES ARE NOT THAT HIGH. THE BLENDED SOLUTION GIVES SOME LOW
POPS IN OUR SOUTH AND THAT SEEMS REASONABLE FOR NOW. TEMPERATURES
WILL CONTINUE TO REMAIN WELL BELOW SEASONAL AVERAGES WITH MANY
PLACES SEEING EVEN HIGHS IN THE NEGATIVE NUMBERS. TEMPS SHOULD BEGIN
TO MODERATE TOWARDS THE END OF THE PERIOD AS THERE ARE SIGNS OF
HEIGHT RISES AS THE MAIN UPPER TROUGH PULLS EAST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 143 PM CST THU JAN 1 2015
TAF SITES HAVE ALL GONE VFR WITH CIGS BETWEEN 3000-7000 FT. SAT LOOP
SHOWS ACTUAL CLEARING MOVING INTO NORTHWESTERN MN...WHICH SHOULD
IMPACT KBJI...KTVF AND KGFK SHORTLY. THE QUESTION WILL BE HOW FAR
SOUTH THE CLEARING GOES TODAY. THE RAP HAS A DECENT HANDLE ON
CURRENT CONDITIONS AND HAS THE DRYING RUNNING OUT OF STEAM BEFORE
REACHING KFAR AND KDVL...SO LEANED TOWARDS THAT SOLUTION. EVEN AS
THERE IS SOME CLEARING IT WILL BE SHORT LIVED AS MOISTURE RETURNS
EARLY TONIGHT AS SOUTH WINDS BEGIN TO PICK UP AHEAD OF A LOW
PRESSURE SYSTEM. FOR NOW HAVE VFR CLOUDS MOVING BACK IN FIRST...THEN
ALL SITES GOING BACK DOWN TO MVFR BETWEEN 06Z AND 12Z FRIDAY. SOME
GUIDANCE SHOWS LIGHT FOG FORMATION BUT FOR NOW WILL LEAVE OUT
REDUCTIONS TO VIS. NORTH WINDS TODAY WILL BECOME LIGHT AND VARIABLE
THIS EVENING BEFORE PICKING UP OUT OF THE SOUTH BY THE END OF THE
PERIOD.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WINTER STORM WATCH FROM FRIDAY AFTERNOON THROUGH SATURDAY
AFTERNOON FOR NDZ006>008-014>016-026-027-054.
MN...WINTER STORM WATCH FROM FRIDAY AFTERNOON THROUGH SATURDAY
AFTERNOON FOR MNZ001-004>009-013>017.
&&
$$
SHORT TERM...SPEICHER
LONG TERM...JR/SPEICHER
AVIATION...SPEICHER
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
144 PM CST THU JAN 1 2015
.UPDATE...
LATEST SFC OBS INDICATE N TO NNE FLOW IS BRINGING IN VERY DRY AIR
MASS WITH DEW POINTS AROUND 0 TO 7 F ACROSS MOST OF THE NORTHERN
PORTIONS OF CWA...TRANSITIONING QUICKLY TO 15 TO 20 F ALONG AND
SOUTH OF THE HWY 200 CORRIDOR. CONSEQUENTLY NOT SEEING ANY REPORTS
OF LIGHT SNOW ACROSS NORTHERN SITES WITH THE DRY LOW LYR...WHILE
THERE ARE STILL A FEW REPORTS ACROSS OTTER TAIL AND GRANT
COUNTIES. ISENTROPIC CHARTS INDICATE CONDENSATION PRESSURE
DEFICITS CLIMB QUICKLY BY 18Z...WHICH SHOULD HELP SCOUR OUT
REMAINING CLOUD COVER AND PUSH TO THE FAR SOUTHERN VALLEY ANY AFTN
CLOUD COVER. WILL REMOVE POPS FOR ALL BUT SE AND E CNTRL ZONES FOR
REMAINDER OF MORNING BUT KEEP MENTION OF FLURRIES THROUGHOUT AREAS
OF CLOUD COVER. WILL ALSO ADJUST AFTN SKY FOR EXPECTED TRENDS. LOW
SUN ANGLE MAKING IT DIFFICULT TO SEE HOW QUICKLY CLEARING LINE IS
MOVING...SO MAY NEED TO MAKE FURTHER ADJUSTMENTS AT 19Z UPDATE.
UPDATE ISSUED AT 743 AM CST THU JAN 1 2015
HIGH TEMPS TODAY TWEAKED A BIT WITH TIMING OF COLD AIR CURRENTLY
MOVING INTO THE AREA. OTHERWISE NO CHANGES MADE AT THIS UPDATE.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 403 AM CST THU JAN 1 2015
UPPER LEVEL TROUGHS OVER THE GULF OF AK AND THE UPPER LEVEL LOW OVER
THE DESERT SOUTHWEST FORECAST TO NEARLY PHASE UP OVER THE CENTRAL
PLAINS BY THE END OF THE PERIOD. SURFACE LOW FORECAST TO BOMB OUT
FROM THE LOWER OH VALLEY INTO THE GREAT LAKE STATES BY THE END OF
THE PERIOD. LEE SIDE SURFACE TROUGH TO DEVELOP OVER MT/WY AND WILL
MOVE OUT INTO SD BY 12Z SAT. WILL BE LIVING ALONG THE BAROCLINIC
ZONE THE NEXT COUPLE DAYS. IN THE MEANTIME QUITE FAST TRANSITIONS
WITH WARM AIR TO THE SOUTH AND WEST AND COLD AIR NORTH AND EAST.
MODEL SOUNDINGS INDICATED LOWER LAYERS SATURATE QUICKLY THIS MORNING
AHEAD OF A COLD FRONT. COLD AIR OVER SOUTHERN CANADA WILL BRUSH THE
AREA FOR MAINLY THIS MORNING. WARM ADVECTION WILL QUICKLY RETURN
TONIGHT. LIGHT SNOW EXPECTED ACROSS THE AREA THIS MORNING WITH SHORT
WAVE/JET STREAK MOVING THROUGH.
WILL ADD LIGHT SNOW FOR FRI MORNING WITH WARM ADVECTION AND
BAROCLINIC ZONE IN THE AREA. OTHERWISE MORE SIGNIFICANT SNOW
EXPECTED TO START FRI AFTERNOON. THROUGH SAT AFTERNOON. POTENTIAL
FOR 6 OR MORE INCHES OF SNOW GENERALLY NORTH OF HIGHWAY 2. WILL
ISSUE A WINTER STORM WATCH FOR THAT AREA.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 403 AM CST THU JAN 1 2015
FOR SUNDAY THROUGH WEDNESDAY...FORECAST AREA IS DOMINATED BY AN
UPPER LEVEL TROUGH AND ARCTIC HIGH PRESSURE. 00Z GFS/ECMWF PRETTY
SIMILAR IN OVERALL PATTERN THOUGH ECMWF IS A BIT COLDER WITH ARCTIC
AIR. COLDEST DAY SUNDAY...SOME CLOUDS AND RISK OF VERY LIGHT SNOW
WILL MOVE ALONG THE SOUTH AND NORTH DAKOTA BORDER MONDAY AS A SYSTEM
MOVES INTO THE CENTRAL PLAINS PER GFS...BUT ECMWF KEEPS IT WELL
SOUTH DUE TO STRONGER HIGH. HIGH PRESSURE AND CONTINUED BELOW NORMAL
TEMPS TUES-WED PERIOD. TEMP MODERATION SEEMS LIKELY END OF NEXT
WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 143 PM CST THU JAN 1 2015
TAF SITES HAVE ALL GONE VFR WITH CIGS BETWEEN 3000-7000 FT. SAT LOOP
SHOWS ACTUAL CLEARING MOVING INTO NORTHWESTERN MN...WHICH SHOULD
IMPACT KBJI...KTVF AND KGFK SHORTLY. THE QUESTION WILL BE HOW FAR
SOUTH THE CLEARING GOES TODAY. THE RAP HAS A DECENT HANDLE ON
CURRENT CONDITIONS AND HAS THE DRYING RUNNING OUT OF STEAM BEFORE
REACHING KFAR AND KDVL...SO LEANED TOWARDS THAT SOLUTION. EVEN AS
THERE IS SOME CLEARING IT WILL BE SHORT LIVED AS MOISTURE RETURNS
EARLY TONIGHT AS SOUTH WINDS BEGIN TO PICK UP AHEAD OF A LOW
PRESSURE SYSTEM. FOR NOW HAVE VFR CLOUDS MOVING BACK IN FIRST...THEN
ALL SITES GOING BACK DOWN TO MVFR BETWEEN 06Z AND 12Z FRIDAY. SOME
GUIDANCE SHOWS LIGHT FOG FORMATION BUT FOR NOW WILL LEAVE OUT
REDUCTIONS TO VIS. NORTH WINDS TODAY WILL BECOME LIGHT AND VARIABLE
THIS EVENING BEFORE PICKING UP OUT OF THE SOUTH BY THE END OF THE
PERIOD.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WINTER STORM WATCH FROM FRIDAY AFTERNOON THROUGH SATURDAY
AFTERNOON FOR NDZ006>008-014>016-026-027-054.
MN...WINTER STORM WATCH FROM FRIDAY AFTERNOON THROUGH SATURDAY
AFTERNOON FOR MNZ001-004>009-013>017.
&&
$$
UPDATE...SPEICHER
SHORT TERM...HOPPES
LONG TERM...RIDDLE
AVIATION...SPEICHER
AREA FORECAST DISCUSSION
NWS NORMAN OK
1130 AM CST THU JAN 1 2015
.AVIATION...
LIGHT RAIN AND FREEZING RAIN WILL CONTINUE ACROSS SOUTHERN AND
EASTERN OKLAHOMA THROUGH 00Z FRI. THEREAFTER...MAINLY DRY
CONDITIONS EXPECTED THROUGH EARLY FRI MORNING. HOWEVER...MVFR TO
IFR CIGS AND VSBYS WILL LIKELY PERSIST FROM KSPS/KLAW TO
KCSM/KHBR. WINDS WILL SHIFT AROUND TO THE NORTH EARLY FRI...AND
FREEZING DRIZZLE AND FREEZING RAIN WILL BUILD INTO SOUTHWESTERN
TERMINALS BY 12Z...SPREADING NORTHWARD THROUGH THE DAY. FREEZING
RAIN MAY CHANGE OVER TO RAIN DURING THE AFTERNOON HOURS FRIDAY.
&&
.PREV DISCUSSION... /ISSUED 555 AM CST THU JAN 1 2015/
AVIATION...
01/12Z TAFS...PRIMARILY MVFR/IFR CONDITIONS EXPECTED MOST OF THE
FORECAST PERIOD. AREAS OF FREEZING DRIZZLE/FREEZING RAIN EXPECTED
TO AFFECT ALL BUT FAR NORTHERN OKLAHOMA TERMINALS...WHERE PRECIP
WILL MAINLY BE SNOW THIS MORNING INTO EARLY AFTERNOON. MOST
PERSISTENT LIGHT FZDZ/FZRA EXPECTED NEAR AND SOUTH OF KHBR AND
KOUN. BREAK IN MOST OF THE PRECIP EXPECTED TOWARD AND AFTER 20-22Z
BUT CIGS/VSBY WILL KEEP IFR/MVFR CONDITIONS GOING ALL BUT NORTHERN
OKLAHOMA SITES. WIDESPREAD FREEZING/FROZEN PRECIP EXPECTED TO
SPREAD OVER REGION JUST AFTER THIS TAF PERIOD AND LASTING MOST OF
THE DAY FRIDAY.
PREV DISCUSSION... /ISSUED 452 AM CST THU JAN 1 2015/
DISCUSSION...
WAVE NUMBER ONE OF PRECIPITATION IS ONGOING ACROSS SOUTHERN
OKLAHOMA AND WESTERN TEXAS THIS MORNING. RADAR TRENDS SHOW
ENHANCEMENT OF RADAR REFLECTIVITY IN THE TEXAS PANHANDLE. THE
CELLULAR STRUCTURE AND ENHANCED REFLECTIVITY SUGGEST THIS IS
ASSOCIATED WITH SLEET. BOTH THE HRRR AND RAP SUGGEST THIS WILL
CONTINUE TO DEVELOP AND MOVE EASTWARD WITH THE POTENTIAL FOR A
WINTRY MIX EVEN NORTH OF I-40 THIS MORNING INTO EARLY AFTERNOON.
THEREFORE...DECIDED TO EXPAND THE WINTER WEATHER ADVISORY FARTHER
NORTH.
WAVE NUMBER ONE WILL EXIT THE AREA LATE AFTERNOON INTO EARLY
EVENING. ATTENTION THEN TURNS TO SECOND WAVE OF PRECIPITATION THAT
IS ASSOCIATED WITH THE MAIN UPPER LEVEL LOW. A MORE WIDESPREAD
PRECIPITATION EVENT IS EXPECTED. PRECIPITATION WILL LIKELY DEVELOP
IN WESTERN NORTH TEXAS EARLY FRIDAY MORNING AND LIFT NORTHEASTWARD
THROUGH THE DAY FRIDAY. BECAUSE OF THE EARLY ONSET...THERE IS
CONCERN OF A SIGNIFICANT ICING EVENT ACROSS WESTERN NORTH TEXAS.
THE FORECAST ON FRIDAY WILL DEPEND ON THE EVOLUTION OF THE SFC 32F
WETBULB TEMPERATURE. LATEST GUIDANCE SUGGESTS THIS COULD BE VERY
CLOSE TO THE I-44 CORRIDOR BY FRIDAY AFTERNOON. OPTED FOR A MIX OF
RAIN/FREEZING RAIN ALONG I-44...WITH A FREEZING RAIN/SLEET MIX
NORTHWEST AND ALL RAIN SOUTHEAST.
A TRANSITION TO SNOW WILL OCCUR LATE FRIDAY INTO SATURDAY AS THE
UPPER LEVEL LOW PASSES THROUGH OKLAHOMA. BOTH THE PARALLEL GFS AND
ECMWF STILL SUGGEST THERE COULD BE ACCUMULATING SNOW IN NORTHERN
OKLAHOMA SATURDAY. THERE IS THE POTENTIAL THERE COULD BE ENOUGH
ACCUMULATING SNOW FOR HEADLINES. THE REST OF OKLAHOMA AND WESTERN
NORTH TEXAS COULD BE DRY SLOTTED SATURDAY.
AFTER COLLABORATION WITH SURROUNDING OFFICES...DECIDED TO HOLD
OFF ON ANY HEADLINES FOR FRIDAY AND SATURDAY. NEVERTHELESS...HEADLINES
WILL LIKELY BE REQUIRED FOR PARTS OF THE AREA FRIDAY INTO SATURDAY
FOR ACCUMULATING ICE AND/OR SNOW. STAY-TUNED!
BEYOND SATURDAY...A RATHER COLD DAY IS EXPECTED ON SUNDAY BEHIND THE
STORM SYSTEM. TEMPERATURES WILL SLOWLY MODERATE BEFORE ANOTHER COLD
FRONT APPROACHES THE REGION AROUND MID-WEEK. THE FORECAST IS DRY
BEYOND SATURDAY.
MAHALE
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 27 34 31 39 / 20 60 70 30
HOBART OK 24 33 29 40 / 20 50 60 20
WICHITA FALLS TX 29 34 32 43 / 60 80 70 20
GAGE OK 18 33 22 35 / 0 20 40 50
PONCA CITY OK 24 33 30 37 / 10 30 70 40
DURANT OK 32 36 36 46 / 50 80 80 40
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR OKZ012-
013-016>048-050>052.
TX...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR
TXZ083>090.
&&
$$
06/84
AREA FORECAST DISCUSSION
NWS TULSA OK
1124 AM CST THU JAN 1 2015
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
CURRENTLY SEEING VFR CONDITIONS ACROSS EASTERN OKLAHOMA AND
WESTERN ARKANSAS. HOWEVER...THAT WILL CHANGE OVER THE NEXT
FEW HOURS AS CONDITIONS DETERIORATE. WILL SEE IFR CONDITIONS
LATER TONIGHT AS LOW CLOUDS AND FOG DEVELOP ACROSS THE AREA.
&&
.PREV DISCUSSION... /ISSUED 942 AM CST THU JAN 1 2015/
DISCUSSION...
THE FORECAST FOR TODAY HAS A HUGE BUST POTENTIAL. IT ALL HINGES
ON THE LOCATION OF THE FREEZING LINE AND IF THE HRRR QPF PANS
OUT. THE FREEZING LINE IS NOW LOCATED ACROSS SOUTHEAST OKLAHOMA
INTO WEST-CENTRAL ARKANSAS. HOWEVER...THERE MAY STILL SOME POCKETS OF
BELOW FREEZING TEMPERATURES IN THIS AREA. IT IS BASICALLY GOING TO
BE RACE BETWEEN THE PRECIPITATION SHIELD AND THE FREEZING LINE...TO
DETERMINE THE PRECIPITATION TYPE ACROSS NORTHEAST OKLAHOMA AND NORTHWEST
ARKANSAS THIS AFTERNOON. WILL CONTINUE WINTER WEATHER ADVISORY AS IT
IS FOR NOW WITH MAINLY FREEZING RAIN AND SLEET EXPECTED ACROSS NORTHEAST
OKLAHOMA AND NORTHWEST ARKANSAS THIS AFTERNOON. LIGHT ACCUMULATIONS OF
ICE ARE EXPECTED. HOWEVER...TRAVEL IMPACTS CAN BE GREAT WITH EVEN A THIN
GLAZE OF ICE. WILL MORE THAN LIKELY SEE MAINLY RAIN ACROSS THE SOUTH
WITH PATCHES OF SLEET.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...WINTER WEATHER ADVISORY UNTIL 6 PM THURSDAY FOR OKZ060-OKZ061-
OKZ062-OKZ063-OKZ064-OKZ065-OKZ066-OKZ067-OKZ068-OKZ069-
OKZ070-OKZ071-OKZ072-OKZ073-OKZ074-OKZ075-OKZ076.
AR...WINTER WEATHER ADVISORY UNTIL 6 PM THURSDAY FOR ARZ001-ARZ002-
ARZ010-ARZ011-ARZ019-ARZ020-ARZ029.
&&
$$
AVIATION...10
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
214 PM CST THU JAN 1 2015
.DISCUSSION...WEAK HIGH PRESSURE CONTINUES TO COVER MIDDLE
TENNESSEE EARLY THIS AFTERNOON WITH A VFR OVERCAST STRATOCU DECK
KEEPING A LID ON TEMPERATURES. RADAR MOSAIC SHOWS A LARGE AREA OF
MAINLY LIGHT RAIN OVER NORTHERN MS AND EXTREME SW TN, BUT GIVEN
LARGE DEW POINT SPREADS STILL IN PLACE ACROSS THE MID STATE, RAIN
WILL BE SLOW TO ARRIVE HERE. HRRR DOES SHOW SOME DEVELOPMENT
DURING THE EVENING AND OVERNIGHT, WITH MOST OF THE ACTIVITY
REMAINING IN THE RELATIVELY WARM AIR OF SOUTHERN MIDDLE TENNESSEE.
SCATTERED ACTIVITY MAY DEVELOP ACROSS OUR NORTH BEFORE 12Z, AND UP
AGAINST THE KY STATE LINE THIS PRECIPITATION MAY START OFF AS A
RA/FZRA OR RA/IP MIXTURE, BUT ACCUMULATIONS ARE NOT EXPECTED. IN
THE MEANTIME, A DEVELOPING LOW TO OUR SW WILL COME RACING NE`WD
INTO THE OZARKS BY 12Z SATURDAY, BRINGING A WARM FRONT NORTHWARD
ACROSS MIDDLE TENNESSEE SO THAT TEMPERATURES SATURDAY MAY WARM
INTO THE 60`S OFF THE PLATEAU. MODEL SOUNDINGS DO SHOW SOME
ELEVATED INSTABILITY WITH THIS SYSTEM, SO WILL INCLUDE TS IN THE
FORECAST FOR SATURDAY AND SATURDAY NIGHT. CAN`T COMPLETELY RULE
OUT A THUNDERSTORM OR TWO PRIOR TO 12Z SATURDAY, BUT THE BEST
INSTABILITY WON`T OCCUR UNTIL DURING THE DAY, SO WILL LIMIT TS TO
DAY 3 ONLY. SPC ALSO HAS US IN A GENERAL THUNDERSTORM AREA ON DAY
3, WITH FROPA OCCURRING BETWEEN 00Z AND 12Z SUNDAY. THERE WILL
LIKELY BE SOME LEFTOVER RAIN ON SUNDAY, BUT THEN LOOK FOR DRY
WEATHER FROM SUNDAY NIGHT AT LEAST THROUGH THURSDAY. TEMPERATURES
NEXT WEEK WILL REMAIN COLDER THAN NORMAL AS WE NEVER DO REALLY
ESTABLISH ANY MEANINGFUL RETURN FLOW, SO IT`S GOING TO A COLD
WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE 34 41 40 62 / 50 80 100 90
CLARKSVILLE 31 38 37 63 / 40 70 100 100
CROSSVILLE 33 44 43 58 / 60 80 100 80
COLUMBIA 34 44 42 63 / 60 80 100 90
LAWRENCEBURG 33 45 44 64 / 60 90 100 90
WAVERLY 31 41 40 63 / 50 80 100 100
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
ROSE
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1213 PM CST THU JAN 1 2015
.UPDATE...
SFC AND SHORT TERM HI RES MODEL ANALYSIS SHOWS THE 32 DEGREE LINE
SLOWLY CRAWLING NORTH OF OUR CWA BORDER BY EARLY THIS AFTERNOON.
SOME SFC OBS ARE STILL SHOWING AT OR JUST BELOW FREEZING FOR AREAS
ALONG THE BORDER AT 18Z. MOST RETURNS ON RADAR ARE EITHER NOT
REACHING THE SURFACE OR VERY LIGHT DRIZZLE AT THE MOMENT SO DID
NOT WANT TO EXTEND THE WARNING BEYOND 18Z. JUST CAPTURED THE MINOR
TRAVEL HAZARDS IN AN SPS FOR THE FIRST COUPLE HOURS OF THE AFTERNOON.
OTHERWISE...SOME SMALL ADJUSTMENTS TO THIS AFTERNOON PRECIP
CHANCES WERE MADE TO BETTER AGREE WITH NEIGHBORS AND BASED OFF
HRRR/WRF INPUT AND REST OF FORECAST PACKAGE LOOKS GOOD THROUGH
TONIGHT.
TB3
&&
.PREV DISCUSSION... /ISSUED 1148 AM CST THU JAN 1 2015/
AVIATION...
ISENTROPIC LIFT OF A MOIST AIRMASS OVER THE SHALLOW COLD AIRMASS
WILL MAINTAIN IFR/LIFR CIGS/VSBYS THIS AFTERNOON THROUGH FRIDAY.
PERIODS OF -RADZ AND BR ARE EXPECTED. N TO NE WINDS OF 10 KTS OR
LESS WILL PREVAIL...EXCEPT VRBL LESS THAN 5 KTS ALONG RIO GRANDE.
PREV DISCUSSION... /ISSUED 714 AM CST THU JAN 1 2015/
UPDATE...
PLEASE SEE THE 12Z AVIATION DISCUSSION BELOW.
AVIATION...
CIGS WILL CONTINUE TO LOWER THROUGHOUT THE DAY AS LIGHT PRECIPITATION
CONTINUES TO MOVE FROM SOUTHWEST TO NORTHEAST ACROSS THE REGION.
MOST TAF SITES ARE EITHER CURRENTLY IFR OR WILL DROP INTO IFR
WITHIN THE NEXT COUPLE OF HOURS. ALL LIQUID PRECIPITATION IS
EXPECTED AT OUR TAF SITES AS TEMPERATURES REMAIN ABOVE FREEZING.
PREV DISCUSSION... /ISSUED 417 AM CST THU JAN 1 2015/
SHORT TERM (TODAY THROUGH FRIDAY)...
LIGHT FREEZING PRECIPITATION CONTINUES OVER THE ADVY AND WARNING
AREAS OF THE SRN EDWARDS PLATEAU...HILL COUNTRY AND BALCONES
ESCARPMENT. A CLUSTER OF WEAK THUNDERSTORMS CROSSED FROM NRN
MEXICO AND LOOKS TO BE PRODUCING A BRIGHT BAND OF WHAT IS PROBABLY
SNOW MELTING INTO RAIN AND POSSIBLY A PARTIAL MELT/REFREEZE TO
SLEET AND GRAUPEL. THIS CONVECTIVE AREA IS LOSING THE CELLULAR
STRUCTURE AND SHOULD CONTINUE TO WEAKEN AS IT LIFTS NE. THUS WILL
LEAVE OUT THE MENTION OF THUNDER AND LET NOWCASTS HANDLE WHAT
SHOULD BE A SHORT-LIVED EVENT.
THE DAYBREAK EMERGENCE OF CONVECTIVE SLEET BAND IS EXPECTED TO
TRACK RIGHT ALONG THE EASTERN PART OF THE BALCONES ESCARPMENT.
THUS AM HESITANT TO WARM MORNING TEMPERATURE FORECASTS TO MATCH
THE CURRENT TRENDS HOLDING ABOVE FREEZING. HI-RES MODELS HAVE KEPT
WITH THE CONVECTIVE BANDING AREA FORMING FARTHER NORTH...BUT THE
LATEST RUNS OF THE HRRR DEPICT THE ONGOING CONVECTIVE AREA WELL
AND SEND IT ACROSS THE AUSTIN METRO AREA AND NW PART OF THE SAN
ANTONIO METRO AREA THROUGH DAYBREAK. WHILE THIS CLUSTER OF
MODERATE PRECIPITATION COULD LOWER TEMPS TO FREEZING
BRIEFLY...EXPECT THE WEAKENING TREND TO ALLOW MOST AREAS IN THE
ADVISORY TO HOLD ONTO ABOVE FREEZING TEMPERATURES WITH MORE
ISOLATED FROZEN CONDITIONS POSSIBLE AT HIGHER ELEVATIONS. A
SECONDARY CONVECTIVE BAND REMAINS IN THE HRRR PICTURE WHICH SHOULD
POTENTIALLY ADD TO THE FREEZING RAIN/SLEET MIX OVER THE WARNING
AREA AT AROUND DAYBREAK. THUS THE ONGOING WINTER STORM WARNING AND
WINTER WEATHER ADVISORY AREA IS THUS CONSIDERED APPROPRIATE AND NO
WSW UPDATES ARE PLANNED.
THE CONSENSUS MODEL POPULATION OF THE TEMPERATURES IN THE GRIDDED
DATA SUGGESTED A QUICK WARM- UP TO ABOVE FREEZING...BUT WE FAVOR A
MORE GRADUAL RISE IN THE MORNING PERIOD WHERE ICING HAS OCCURRED.
BY NOON...MODEL SOUNDINGS SUGGEST THERE SHOULD BE AMPLE TIME FOR
THE WARMING TO HAVE OCCURRED...AS THE FRONTAL INVERSION SHOULD
CONTINUE TO BE MODIFIED BY FALLING RAIN AND DRIZZLE. A COLD RAIN
REMAINS IN THE PICTURE THROUGH FRIDAY. TEMPERATURES SHOULD BE
ALMOST FLAT FROM THIS AFTERNOON THROUGH LATE FRIDAY MORNING BEFORE
WARMING INTO THE 40S OVER MOST AREAS LATE FRIDAY. DESPITE THE HIGH
POPS BENEATH THE SOLID OVERRUNNING PATTERN...QPF AMOUNTS REMAIN
CONSERVATIVE AND GENERALLY BELOW 1/2 INCH.
LONG TERM (FRIDAY NIGHT THROUGH WEDNESDAY)...
THE EASTWARD EJECTION OF A SLOW MOVING UPPER LOW BRINGS A SLIGHTLY
MORE CONVECTIVE ENVIRONMENT TO TX BY FRIDAY EVENING. THE INCREASED
POTENTIAL FOR THUNDER TRANSLATES TO SLIGHTLY HIGHER QPF AMOUNTS
WITH ANOTHER 1/2 INCH OF RAIN POSSIBLE IN THE FRIDAY NIGHT PERIOD
ALONE.
MODEL CONSENSUS REMAINS IN GOOD AGREEMENT TO BRING DECREASING
CLOUDS AND RAIN CHANCES BY MIDDAY SATURDAY AND PROBABLY THE
WARMEST TEMPS OF THE WEEK. THIS IS BECAUSE ANOTHER FRONT ARRIVES
BY SUNDAY MORNING. THE ECMWF TRENDED SHARPLY COLDER FROM THIS
FRONT WITH A MUCH ENHANCED POLAR TROUGH OVER THE EASTERN US. THE
GFS HAS ALSO TRENDED SLIGHTLY COLDER...SO A BLEND OF THESE TWO
MODELS LOOKS REASONABLE. AM HESITANT TO BUY INTO THE ECMWF BASED
GUIDANCE THAT PROJECTED MIDDLE TEENS OVER THE HILL COUNTRY MONDAY
MORNING. THE COLD PATTERN IS SHOWN BY BOTH THE GFS AND ECMWF
SOLUTIONS TO BE SHORT-LIVED WITH A PROGRESSIVE ZONAL PATTERN
PUSHING AN UPPER RIDGE OVER TX BY MIDWEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 39 38 43 40 59 / 80 90 80 80 30
AUSTIN BERGSTROM INTL AIRPORT 40 37 43 39 58 / 80 90 80 80 30
NEW BRAUNFELS MUNI AIRPORT 41 39 45 42 61 / 70 80 70 80 30
BURNET MUNI AIRPORT 38 35 40 37 57 / 90 90 80 80 20
DEL RIO INTL AIRPORT 41 41 49 41 61 / 40 50 40 50 -
GEORGETOWN MUNI AIRPORT 40 36 41 38 56 / 90 90 80 80 30
HONDO MUNI AIRPORT 41 39 47 40 62 / 50 60 50 60 20
SAN MARCOS MUNI AIRPORT 40 38 44 41 59 / 70 80 70 80 30
LA GRANGE - FAYETTE REGIONAL 43 41 47 44 59 / 70 70 80 80 40
SAN ANTONIO INTL AIRPORT 41 39 46 42 61 / 60 80 60 70 20
STINSON MUNI AIRPORT 42 40 46 42 62 / 60 70 60 70 20
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...04
SYNOPTIC/GRIDS...03
PUBLIC SERVICE/DATA COLLECTION...12
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1148 AM CST THU JAN 1 2015
.AVIATION...
ISENTROPIC LIFT OF A MOIST AIRMASS OVER THE SHALLOW COLD AIRMASS
WILL MAINTAIN IFR/LIFR CIGS/VSBYS THIS AFTERNOON THROUGH FRIDAY.
PERIODS OF -RADZ AND BR ARE EXPECTED. N TO NE WINDS OF 10 KTS OR
LESS WILL PREVAIL...EXCEPT VRBL LESS THAN 5 KTS ALONG RIO GRANDE.
&&
.PREV DISCUSSION... /ISSUED 714 AM CST THU JAN 1 2015/
UPDATE...
PLEASE SEE THE 12Z AVIATION DISCUSSION BELOW.
AVIATION...
CIGS WILL CONTINUE TO LOWER THROUGHOUT THE DAY AS LIGHT PRECIPITATION
CONTINUES TO MOVE FROM SOUTHWEST TO NORTHEAST ACROSS THE REGION.
MOST TAF SITES ARE EITHER CURRENTLY IFR OR WILL DROP INTO IFR
WITHIN THE NEXT COUPLE OF HOURS. ALL LIQUID PRECIPITATION IS
EXPECTED AT OUR TAF SITES AS TEMPERATURES REMAIN ABOVE FREEZING.
PREV DISCUSSION... /ISSUED 417 AM CST THU JAN 1 2015/
SHORT TERM (TODAY THROUGH FRIDAY)...
LIGHT FREEZING PRECIPITATION CONTINUES OVER THE ADVY AND WARNING
AREAS OF THE SRN EDWARDS PLATEAU...HILL COUNTRY AND BALCONES
ESCARPMENT. A CLUSTER OF WEAK THUNDERSTORMS CROSSED FROM NRN
MEXICO AND LOOKS TO BE PRODUCING A BRIGHT BAND OF WHAT IS PROBABLY
SNOW MELTING INTO RAIN AND POSSIBLY A PARTIAL MELT/REFREEZE TO
SLEET AND GRAUPEL. THIS CONVECTIVE AREA IS LOSING THE CELLULAR
STRUCTURE AND SHOULD CONTINUE TO WEAKEN AS IT LIFTS NE. THUS WILL
LEAVE OUT THE MENTION OF THUNDER AND LET NOWCASTS HANDLE WHAT
SHOULD BE A SHORT-LIVED EVENT.
THE DAYBREAK EMERGENCE OF CONVECTIVE SLEET BAND IS EXPECTED TO
TRACK RIGHT ALONG THE EASTERN PART OF THE BALCONES ESCARPMENT.
THUS AM HESITANT TO WARM MORNING TEMPERATURE FORECASTS TO MATCH
THE CURRENT TRENDS HOLDING ABOVE FREEZING. HI-RES MODELS HAVE KEPT
WITH THE CONVECTIVE BANDING AREA FORMING FARTHER NORTH...BUT THE
LATEST RUNS OF THE HRRR DEPICT THE ONGOING CONVECTIVE AREA WELL
AND SEND IT ACROSS THE AUSTIN METRO AREA AND NW PART OF THE SAN
ANTONIO METRO AREA THROUGH DAYBREAK. WHILE THIS CLUSTER OF
MODERATE PRECIPITATION COULD LOWER TEMPS TO FREEZING
BRIEFLY...EXPECT THE WEAKENING TREND TO ALLOW MOST AREAS IN THE
ADVISORY TO HOLD ONTO ABOVE FREEZING TEMPERATURES WITH MORE
ISOLATED FROZEN CONDITIONS POSSIBLE AT HIGHER ELEVATIONS. A
SECONDARY CONVECTIVE BAND REMAINS IN THE HRRR PICTURE WHICH SHOULD
POTENTIALLY ADD TO THE FREEZING RAIN/SLEET MIX OVER THE WARNING
AREA AT AROUND DAYBREAK. THUS THE ONGOING WINTER STORM WARNING AND
WINTER WEATHER ADVISORY AREA IS THUS CONSIDERED APPROPRIATE AND NO
WSW UPDATES ARE PLANNED.
THE CONSENSUS MODEL POPULATION OF THE TEMPERATURES IN THE GRIDDED
DATA SUGGESTED A QUICK WARM- UP TO ABOVE FREEZING...BUT WE FAVOR A
MORE GRADUAL RISE IN THE MORNING PERIOD WHERE ICING HAS OCCURRED.
BY NOON...MODEL SOUNDINGS SUGGEST THERE SHOULD BE AMPLE TIME FOR
THE WARMING TO HAVE OCCURRED...AS THE FRONTAL INVERSION SHOULD
CONTINUE TO BE MODIFIED BY FALLING RAIN AND DRIZZLE. A COLD RAIN
REMAINS IN THE PICTURE THROUGH FRIDAY. TEMPERATURES SHOULD BE
ALMOST FLAT FROM THIS AFTERNOON THROUGH LATE FRIDAY MORNING BEFORE
WARMING INTO THE 40S OVER MOST AREAS LATE FRIDAY. DESPITE THE HIGH
POPS BENEATH THE SOLID OVERRUNNING PATTERN...QPF AMOUNTS REMAIN
CONSERVATIVE AND GENERALLY BELOW 1/2 INCH.
LONG TERM (FRIDAY NIGHT THROUGH WEDNESDAY)...
THE EASTWARD EJECTION OF A SLOW MOVING UPPER LOW BRINGS A SLIGHTLY
MORE CONVECTIVE ENVIRONMENT TO TX BY FRIDAY EVENING. THE INCREASED
POTENTIAL FOR THUNDER TRANSLATES TO SLIGHTLY HIGHER QPF AMOUNTS
WITH ANOTHER 1/2 INCH OF RAIN POSSIBLE IN THE FRIDAY NIGHT PERIOD
ALONE.
MODEL CONSENSUS REMAINS IN GOOD AGREEMENT TO BRING DECREASING
CLOUDS AND RAIN CHANCES BY MIDDAY SATURDAY AND PROBABLY THE
WARMEST TEMPS OF THE WEEK. THIS IS BECAUSE ANOTHER FRONT ARRIVES
BY SUNDAY MORNING. THE ECMWF TRENDED SHARPLY COLDER FROM THIS
FRONT WITH A MUCH ENHANCED POLAR TROUGH OVER THE EASTERN US. THE
GFS HAS ALSO TRENDED SLIGHTLY COLDER...SO A BLEND OF THESE TWO
MODELS LOOKS REASONABLE. AM HESITANT TO BUY INTO THE ECMWF BASED
GUIDANCE THAT PROJECTED MIDDLE TEENS OVER THE HILL COUNTRY MONDAY
MORNING. THE COLD PATTERN IS SHOWN BY BOTH THE GFS AND ECMWF
SOLUTIONS TO BE SHORT-LIVED WITH A PROGRESSIVE ZONAL PATTERN
PUSHING AN UPPER RIDGE OVER TX BY MIDWEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 39 38 43 40 59 / 80 90 80 80 30
AUSTIN BERGSTROM INTL AIRPORT 40 37 43 39 58 / 80 90 80 80 30
NEW BRAUNFELS MUNI AIRPORT 41 39 45 42 61 / 70 80 70 80 30
BURNET MUNI AIRPORT 38 35 40 37 57 / 90 90 80 80 20
DEL RIO INTL AIRPORT 41 41 49 41 61 / 40 50 40 50 -
GEORGETOWN MUNI AIRPORT 40 36 41 38 56 / 90 90 80 80 30
HONDO MUNI AIRPORT 41 39 47 40 62 / 50 60 50 60 20
SAN MARCOS MUNI AIRPORT 40 38 44 41 59 / 70 80 70 80 30
LA GRANGE - FAYETTE REGIONAL 43 41 47 44 59 / 70 70 80 80 40
SAN ANTONIO INTL AIRPORT 41 39 46 42 61 / 60 80 60 70 20
STINSON MUNI AIRPORT 42 40 46 42 62 / 60 70 60 70 20
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL NOON CST TODAY FOR THE FOLLOWING
COUNTIES: BANDERA...BLANCO...BURNET...EDWARDS...GILLESPIE...
KENDALL...KERR...LLANO...REAL...VAL VERDE.
&&
$$
MESOSCALE/AVIATION...04
SYNOPTIC/GRIDS...03
PUBLIC SERVICE/DATA COLLECTION...12