Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 02/06/14
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1132 AM MST TUE FEB 4 2014
.UPDATE...
ISSUED AT 1130 AM MST TUE FEB 4 2014
REMOVED SOME LOWER VALLEY ADVISORIES AND EXTEND SOME HIGHER VALLEY
ADVISORIES UNTIL 5 PM.
&&
.UPDATE...
ISSUED AT 850 AM MST TUE FEB 4 2014
VERY SLICK ROADS IS THE THEME THIS MORNING WITH 2-5 INCHES
REPORTED ACROSS THE GRAND VALLEY. AT 830 AM THE RADAR LOOKS
CONVECTIVE WITH THE BEST CONVECTIVE LINE OF SHOWERS SHIFTING
QUICKLY EAST OF A LINE FORM NORWOOD TO DEBEQUE. SO PERIODS OF
HEAVY SNOW WILL AFFECT TRAVEL ON I-70 AND HIGHWAY 50 THROUGH THE
MORNING HOURS.
THE TROUGH IS OVERHEAD AND LINGERS THROUGH THE DAY. THE FINAL VORT
MAX ASSOCIATED WITH THE NW-SE BACKSIDE JET LIFTS THROUGH SE UTAH-
WEST CENTRAL COLORADO THIS AFTERNOON ADDING SOME DYNAMICAL LIFT.
MEANWHILE THE ARCTIC FRONT WAS LEAKING INTO NW COLORADO THIS
MORNING WITH LADORE RAWS WINDS GUSTY FROM THE NORTH. THE 12Z NAM
AND RAP MODELS AGREE THE FRONT WILL WORK THROUGH NW COLORADO TODAY
AND HANG UP ALONG THE ROAN-FLATTOPS THIS AFTERNOON BEFORE THEN
RETREATING NORTHWARD SOMEWHAT AS THE VORT MAX/JET PASS IN THE LATE
AFTERNOON. BY MIDNIGHT TONIGHT THE LATEST MODELS ARE PRODUCING
AROUND 5 INCHES OF NEW SNOW IN THE ROAN/FLATTOPS/GRAND MESA/NW SAN
JUANS WITH AROUND 3 INCHES ON THE UNCOMPAHGRE PLATEAU. MOST
VALLEYS LIMITED TO LESS THAN 2 INCHES...THOUGH THE CONVECTIVE
NATURE OF THIS SYSTEM WILL YIELD SOME LOCALLY HIGHER AMOUNTS.
AFTER A BREAK LATE TONIGHT THROUGH WEDNESDAY...SNOWFALL RETURNS TO
THE REGION WEDNESDAY NIGHT-THURSDAY.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 304 AM MST TUE FEB 4 2014
NO CHANGE TO THE VARIOUS WINTER HIGHLIGHTS CURRENTLY IN EFFECT TODAY
THROUGH THIS EVENING...DESPITE THE SLOW START TO THE SNOW IN GRAND
JCT AS OF 300 AM.
UPPER LOW OVER SRN NM WILL EJECT INTO THE SOUTHERN PLAINS TODAY
WHILE ENERGY OVER THE PACIFIC NW CURVES SOUTHEAST ACROSS WY. THIS
WILL TEND TO PIVOT THE NEGATIVELY TILTED TROUGH BETWEEN THE TWO
OVER CO TODAY WHILE ALLOWING AN ARCTIC FRONT TO SAG IN FROM THE
NORTH. THE FORECAST AREA COMES UNDER BROAD UPPER DIVERGENCE
TOWARD 12Z THIS MORNING IN THE NAM/EC MODELS FOR WIDESPREAD
SNOW...BUT THE AREA IS BETWEEN THE Q-G VERTICAL VELOCITY MAXIMUMS
AND FRONTOGENETIC FORCING IS NOT NEARLY AS STRONG IN THE MODELS AS
IN PREVIOUS RUNS TO REALLY FOCUS HEAVIER SNOWFALL. HOWEVER...TEMPS
IN THE MOIST LAYER REMAIN CONDUCIVE TO DENDRITIC SNOW GROWTH AHEAD
OF THE ARCTIC FRONT AND OROGRAPHICS WILL ALSO CONTRIBUTE LIFT.
LAPSE RATES STEEPEN AS THE MID-LEVEL COLD POOL MOVES IN FOR THE
POSSIBILITY OF A CONVECTIVE TINGE TO THE SNOWFALL THIS AFTERNOON.
SPECIFIC HUMIDITY/PRECIPITABLE WATER IS ON THE DECLINE THIS
AFTERNOON AND EVENING AS DRIER AIR BEGINS WORKING IN FROM THE WEST.
THE NEGATIVELY TILTED TROUGH DOESN`T CLEAR THE NORTH UNTIL ABOUT
MIDNIGHT...HOWEVER...SO SNOW SHOULD PERSIST THE LONGEST OVER THE NRN
MTNS TONIGHT. WILL ADD PATCHY FOG TO MANY VALLEYS TONIGHT FROM
RESIDUAL MOISTURE ON THE GROUND DESPITE COLDER AIR BRINGING IN LOWER
DEWPOINTS. EXPECT SUB-ZERO LOW TEMPS TONIGHT ACROSS NW CO.
WEDNESDAY LOOKS LIKE A DOWN DAY FOR PRECIPITATION. WESTERLY FLOW
ALOFT DEVELOPS WITH MID-LEVEL PACIFIC MOISTURE RIDING THE FLOW INTO
OUR AREA DURING THE AFTERNOON. WILL KEEP A CHANCE OF SNOW OVER THE
MTNS WEDNESDAY AFTERNOON. COOLER TEMPS FOR THE NORTH ON WEDNESDAY
WITH LITTLE CHANGE FROM TODAY FOR SE UT AND FAR SW CO.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 304 AM MST TUE FEB 4 2014
LIGHT SNOW WILL CONTINUE OVER HIGHER ELEVATIONS WEDNESDAY NIGHT
INTO THURSDAY MORNING AS AN ELONGATED E-W TROUGH APPROACHES THE
CWA FROM THE NORTH. WHILE EXAMINATION OF UPPER LEVELS INDICATES
MINIMAL JET SUPPORT AND ATTENDANT DIVERGENCE ALOFT...ENOUGH
MOISTURE WILL BE PRESENT AS THE BAROCLINIC ZONE APPROACHES TO
CAUSE SNOW FROM THURSDAY THROUGH FRIDAY WITH HIGHER ELEVATIONS
BEING FAVORED. AS THIS OCCURS...A RELATIVELY WEAK AREA OF LOW PRESSURE
CLOSES OFF OVER WASHINGTON STATE FRIDAY MORNING AND DUE TO ITS
CYCLONIC FLOW...WESTERLY WINDS WILL ALLOW MOISTURE TO ADVECT INTO THE
PAC NW AND REACH ERN UT AND WRN CO. ATTM...BOTH GFS AND EC NOT
REALLY SHOWING AN APPRECIABLE BREAK BETWEEN THESE TWO WX MAKERS
WITH PRECIP CONTINUING THROUGH SUNDAY MORNING. SNOWFALL AMOUNTS
FOR THE 24 HOUR PERIOD FROM THURSDAY TO FRIDAY LOOK TO BE ON THE
LOW SIDE BEFORE PICKING UP FRIDAY INTO SATURDAY. HIGHLIGHTS ARE
EXPECTED FOR THE END OF THE WORK WEEK BUT OPTED NOT TO ISSUE ANY
DURING THIS TIME-FRAME AS HIGHLIGHTS ALREADY IN PLACE FOR CURRENT
STORM.
A VERY BRIEF REPRIEVE SUNDAY MORNING BEFORE ANOTHER SYSTEM BRINGS
ANOTHER SHOT OF WINTER WX TO THE AREA SUNDAY INTO MONDAY. WITH
EVENT SO FAR OUT...BLENDED POPS GIVING SCHC TO CHC -SN FOR MAINLY
HIGHER TERRAIN LOOKS GOOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY NOON)
ISSUED AT 850 AM MST TUE FEB 4 2014
EXPECT IMPROVING THIS AFTERNOON FOR VALLEY TAF SITES WHILE MTN
TAFS ESPECIALLY KSBS...KASE...KEGE AND KTEX WILL LIKELY SEE LOW
CIGS/VIS ALL DAY WITH CONDITIONS SLOWLY IMPROVING AFTER SUNSET.
MOUNTAIN OBSCURATIONS CAN BE EXPECTED ACROSS EASTERN UT AND
WESTERN CO THROUGH MIDNIGHT WITH WIDESPREAD VFR AND ONLY LOCAL MTN
OBSCURATIONS AFTER MIDNIGHT. CLOUD CIGS ON WEDNESDAY SHOULD REMAIN
ABOVE VFR THOUGH MTN TOPS MAY BE OBSCURED AT TIMES NEAR THE CONTINENTAL
DIVIDE.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER WEATHER ADVISORY UNTIL 5 PM MST THIS AFTERNOON COZ003.
WINTER WEATHER ADVISORY UNTIL 11 PM MST THIS EVENING BELOW 7500
FEET FOR COZ017.
WINTER STORM WARNING UNTIL 11 PM MST THIS EVENING ABOVE 7500
FEET FOR COZ017.
WINTER STORM WARNING UNTIL 11 PM MST THIS EVENING COZ010-012.
WINTER STORM WARNING UNTIL 11 PM MST THIS EVENING
COZ009-013-018-019.
WINTER WEATHER ADVISORY UNTIL 5 PM MST THIS AFTERNOON
COZ001-002-007-008-011.
WINTER WEATHER ADVISORY UNTIL 11 PM MST THIS EVENING COZ004.
WINTER WEATHER ADVISORY UNTIL 5 PM MST THIS AFTERNOON COZ005.
UT...WINTER WEATHER ADVISORY UNTIL 5 PM MST THIS AFTERNOON UTZ023-025.
WINTER WEATHER ADVISORY UNTIL 11 PM MST THIS EVENING BELOW 7500
FEET FOR UTZ028.
WINTER STORM WARNING UNTIL 11 PM MST THIS EVENING ABOVE 7500
FEET FOR UTZ028.
&&
$$
SHORT TERM...JAD
LONG TERM...TGR
AVIATION...JOE
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
850 AM MST TUE FEB 4 2014
.UPDATE...
ISSUED AT 850 AM MST TUE FEB 4 2014
VERY SLICK ROADS IS THE THEME THIS MORNING WITH 2-5 INCHES
REPORTED ACROSS THE GRAND VALLEY. AT 830 AM THE RADAR LOOKS
CONVECTIVE WITH THE BEST CONVECTIVE LINE OF SHOWERS SHIFTING
QUICKLY EAST OF A LINE FORM NORWOOD TO DEBEQUE. SO PERIODS OF
HEAVY SNOW WILL AFFECT TRAVEL ON I-70 AND HIGHWAY 50 THROUGH THE
MORNING HOURS.
THE TROUGH IS OVERHEAD AND LINGERS THROUGH THE DAY. THE FINAL VORT
MAX ASSOCIATED WITH THE NW-SE BACKSIDE JET LIFTS THROUGH SE UTAH-
WEST CENTRAL COLORADO THIS AFTERNOON ADDING SOME DYNAMICAL LIFT.
MEANWHILE THE ARCTIC FRONT WAS LEAKING INTO NW COLORADO THIS
MORNING WITH LADORE RAWS WINDS GUSTY FROM THE NORTH. THE 12Z NAM
AND RAP MODELS AGREE THE FRONT WILL WORK THROUGH NW COLORADO TODAY
AND HANG UP ALONG THE ROAN-FLATTOPS THIS AFTERNOON BEFORE THEN
RETREATING NORTHWARD SOMEWHAT AS THE VORT MAX/JET PASS IN THE LATE
AFTERNOON. BY MIDNIGHT TONIGHT THE LATEST MODELS ARE PRODUCING
AROUND 5 INCHES OF NEW SNOW IN THE ROAN/FLATTOPS/GRAND MESA/NW SAN
JUANS WITH AROUND 3 INCHES ON THE UNCOMPAHGRE PLATEAU. MOST
VALLEYS LIMITED TO LESS THAN 2 INCHES...THOUGH THE CONVECTIVE
NATURE OF THIS SYSTEM WILL YIELD SOME LOCALLY HIGHER AMOUNTS.
AFTER A BREAK LATE TONIGHT THROUGH WEDNESDAY...SNOWFALL RETURNS TO
THE REGION WEDNESDAY NIGHT-THURSDAY.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 304 AM MST TUE FEB 4 2014
NO CHANGE TO THE VARIOUS WINTER HIGHLIGHTS CURRENTLY IN EFFECT TODAY
THROUGH THIS EVENING...DESPITE THE SLOW START TO THE SNOW IN GRAND
JCT AS OF 300 AM.
UPPER LOW OVER SRN NM WILL EJECT INTO THE SOUTHERN PLAINS TODAY
WHILE ENERGY OVER THE PACIFIC NW CURVES SOUTHEAST ACROSS WY. THIS
WILL TEND TO PIVOT THE NEGATIVELY TILTED TROUGH BETWEEN THE TWO
OVER CO TODAY WHILE ALLOWING AN ARCTIC FRONT TO SAG IN FROM THE
NORTH. THE FORECAST AREA COMES UNDER BROAD UPPER DIVERGENCE
TOWARD 12Z THIS MORNING IN THE NAM/EC MODELS FOR WIDESPREAD
SNOW...BUT THE AREA IS BETWEEN THE Q-G VERTICAL VELOCITY MAXIMUMS
AND FRONTOGENETIC FORCING IS NOT NEARLY AS STRONG IN THE MODELS AS
IN PREVIOUS RUNS TO REALLY FOCUS HEAVIER SNOWFALL. HOWEVER...TEMPS
IN THE MOIST LAYER REMAIN CONDUCIVE TO DENDRITIC SNOW GROWTH AHEAD
OF THE ARCTIC FRONT AND OROGRAPHICS WILL ALSO CONTRIBUTE LIFT.
LAPSE RATES STEEPEN AS THE MID-LEVEL COLD POOL MOVES IN FOR THE
POSSIBILITY OF A CONVECTIVE TINGE TO THE SNOWFALL THIS AFTERNOON.
SPECIFIC HUMIDITY/PRECIPITABLE WATER IS ON THE DECLINE THIS
AFTERNOON AND EVENING AS DRIER AIR BEGINS WORKING IN FROM THE WEST.
THE NEGATIVELY TILTED TROUGH DOESN`T CLEAR THE NORTH UNTIL ABOUT
MIDNIGHT...HOWEVER...SO SNOW SHOULD PERSIST THE LONGEST OVER THE NRN
MTNS TONIGHT. WILL ADD PATCHY FOG TO MANY VALLEYS TONIGHT FROM
RESIDUAL MOISTURE ON THE GROUND DESPITE COLDER AIR BRINGING IN LOWER
DEWPOINTS. EXPECT SUB-ZERO LOW TEMPS TONIGHT ACROSS NW CO.
WEDNESDAY LOOKS LIKE A DOWN DAY FOR PRECIPITATION. WESTERLY FLOW
ALOFT DEVELOPS WITH MID-LEVEL PACIFIC MOISTURE RIDING THE FLOW INTO
OUR AREA DURING THE AFTERNOON. WILL KEEP A CHANCE OF SNOW OVER THE
MTNS WEDNESDAY AFTERNOON. COOLER TEMPS FOR THE NORTH ON WEDNESDAY
WITH LITTLE CHANGE FROM TODAY FOR SE UT AND FAR SW CO.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 304 AM MST TUE FEB 4 2014
LIGHT SNOW WILL CONTINUE OVER HIGHER ELEVATIONS WEDNESDAY NIGHT
INTO THURSDAY MORNING AS AN ELONGATED E-W TROUGH APPROACHES THE
CWA FROM THE NORTH. WHILE EXAMINATION OF UPPER LEVELS INDICATES
MINIMAL JET SUPPORT AND ATTENDANT DIVERGENCE ALOFT...ENOUGH
MOISTURE WILL BE PRESENT AS THE BAROCLINIC ZONE APPROACHES TO
CAUSE SNOW FROM THURSDAY THROUGH FRIDAY WITH HIGHER ELEVATIONS
BEING FAVORED. AS THIS OCCURS...A RELATIVELY WEAK AREA OF LOW PRESSURE
CLOSES OFF OVER WASHINGTON STATE FRIDAY MORNING AND DUE TO ITS
CYCLONIC FLOW...WESTERLY WINDS WILL ALLOW MOISTURE TO ADVECT INTO THE
PAC NW AND REACH ERN UT AND WRN CO. ATTM...BOTH GFS AND EC NOT
REALLY SHOWING AN APPRECIABLE BREAK BETWEEN THESE TWO WX MAKERS
WITH PRECIP CONTINUING THROUGH SUNDAY MORNING. SNOWFALL AMOUNTS
FOR THE 24 HOUR PERIOD FROM THURSDAY TO FRIDAY LOOK TO BE ON THE
LOW SIDE BEFORE PICKING UP FRIDAY INTO SATURDAY. HIGHLIGHTS ARE
EXPECTED FOR THE END OF THE WORK WEEK BUT OPTED NOT TO ISSUE ANY
DURING THIS TIME-FRAME AS HIGHLIGHTS ALREADY IN PLACE FOR CURRENT
STORM.
A VERY BRIEF REPRIEVE SUNDAY MORNING BEFORE ANOTHER SYSTEM BRINGS
ANOTHER SHOT OF WINTER WX TO THE AREA SUNDAY INTO MONDAY. WITH
EVENT SO FAR OUT...BLENDED POPS GIVING SCHC TO CHC -SN FOR MAINLY
HIGHER TERRAIN LOOKS GOOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY NOON)
ISSUED AT 850 AM MST TUE FEB 4 2014
EXPECT IMPROVING THIS AFTERNOON FOR VALLEY TAF SITES WHILE MTN
TAFS ESPECIALLY KSBS...KASE...KEGE AND KTEX WILL LIKELY SEE LOW
CIGS/VIS ALL DAY WITH CONDITIONS SLOWLY IMPROVING AFTER SUNSET.
MOUNTAIN OBSCURATIONS CAN BE EXPECTED ACROSS EASTERN UT AND
WESTERN CO THROUGH MIDNIGHT WITH WIDESPREAD VFR AND ONLY LOCAL MTN
OBSCURATIONS AFTER MIDNIGHT. CLOUD CIGS ON WEDNESDAY SHOULD REMAIN
ABOVE VFR THOUGH MTN TOPS MAY BE OBSCURED AT TIMES NEAR THE CONTINENTAL
DIVIDE.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER WEATHER ADVISORY UNTIL 5 PM MST THIS AFTERNOON COZ003.
WINTER WEATHER ADVISORY UNTIL NOON MST TODAY
COZ001-002-006>008-011-020.
WINTER WEATHER ADVISORY UNTIL 11 PM MST THIS EVENING BELOW 7500
FEET FOR COZ017.
WINTER STORM WARNING UNTIL 11 PM MST THIS EVENING ABOVE 7500
FEET FOR COZ017.
WINTER STORM WARNING UNTIL 11 PM MST THIS EVENING COZ010-012.
WINTER STORM WARNING UNTIL 11 PM MST THIS EVENING
COZ009-013-018-019.
WINTER WEATHER ADVISORY UNTIL 11 PM MST THIS EVENING COZ004.
WINTER WEATHER ADVISORY UNTIL 5 PM MST THIS AFTERNOON COZ005.
UT...WINTER WEATHER ADVISORY UNTIL 5 PM MST THIS AFTERNOON UTZ023-025.
WINTER WEATHER ADVISORY UNTIL NOON MST TODAY UTZ027.
WINTER WEATHER ADVISORY UNTIL 11 PM MST THIS EVENING BELOW 7500
FEET FOR UTZ028.
WINTER STORM WARNING UNTIL 11 PM MST THIS EVENING ABOVE 7500
FEET FOR UTZ028.
&&
$$
UPDATE...JOE
SHORT TERM...JAD
LONG TERM...TGR
AVIATION...JOE
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
310 PM EST TUE FEB 4 2014
.SYNOPSIS...
19Z WATER VAPOR AND H4 RAP ANALYSIS SHOWING AN AMPLIFIED PATTERN
DEVELOPING ACROSS THE COUNTRY. THE MAIN FEATURE OF NOTE IS A DEEP
AND INCREASINGLY NEGATIVELY TILTED TROUGH THAT IS SWINGING OUT OVER
THE CENTRAL PLAINS FROM THE INTER-MOUNTAIN WEST. AT THE BASE OF THIS
TROUGH WE FIND A STRONG SHORTWAVE AND ASSOCIATED STRONG UPPER JET
EJECTING EASTWARD ACROSS THE SOUTHERN PLAINS. THIS FEATURE AND ITS
CYCLOGENESIS REFLECTION AT THE SURFACE WILL/IS SPREADING WINTRY
PRECIPITATION ACROSS A VAST STRETCH OF THE CENTRAL
PLAINS/MIDWEST...AND NORTHEAST THROUGH WEDNESDAY. THIS WINTRY
WEATHER IS FAR REMOVED FROM THE CONDITIONS OVER THE FLORIDA
PENINSULA...WHERE THE DEEPENING TROUGH/HEIGHT FALLS TO OUR WEST HAVE
ACTUALLY HELPED TO AMPLIFY THE RIDGE IN PLACE OVER OUR HEADS.
THE 04/12Z KTBW SOUNDING PROFILE SHOWS THE INFLUENCE OF THE RIDGE
WITH A DEFINED SUBSIDENCE INVERSION AROUND 650MB. A FAIRLY MOIST
COLUMN EXISTS BENEATH THIS INVERSION.
AT THE SURFACE...A LIGHT SOUTHEAST FLOW IN PLACE ON THE FAR SOUTHERN
PERIPHERY OF HIGH PRESSURE RIDGING DOWN THE EASTERN SEABOARD. WELL
TO OUR WEST WE FIND A DEVELOPING FRONTAL WAVE THAT WILL PASS WELL TO
OUR NORTH TONIGHT AND DRAG A WEAK COLD FRONT INTO THE REGION LATER
WEDNESDAY.
&&
.SHORT TERM (TONIGHT THROUGH THURSDAY NIGHT)...
TONIGHT...THE FORECAST CONCERN FOR TONIGHT IS THE POTENTIAL FOR
ADVECTION/RE-DEVELOPMENT OF DENSE SEA FOG ONTO THE LAND. WITH THE
RIDGE OVERHEAD AND LITTLE CHANGE IN THE OVERALL SYNOPTIC
SITUATION...A PERSISTENCE FORECAST OF ANOTHER ROUND OF FOG IS THE
BEST WAY TO GO. THE DEVELOPMENT OF THE SEA-FOG AND POTENTIAL
ADVECTION ONSHORE LOOKS TO BE LATER THAN WAS SEEN MONDAY EVENING.
THE SEA-FOG HAS BEEN PUSHED WELL OFFSHORE DURING THE DAY AND WILL
NEED TO ALLOW SOME TIME FOR RE-DEVELOPMENT AFTER THE DIURNAL MIXING
IS DONE THIS EVENING. LAST EVENING DENSE FOG WAS ROLLING ASHORE BY
6-7 PM...WHILE THIS EVENING...THIS PROCESS IS LIKELY TO TAKE LONGER
TO OCCUR. TIMING AND FORECASTING OF DENSE FOG IN GENERAL IS...
DIFFICULT...TO SAY THE LEAST. BASED ON THE LATEST GUIDANCE AND
SATELLITE IMAGERY BACKED THE TIMING UP BY SEVERAL HOURS TILL AT
LEAST THE LATE EVENING FOR COASTAL AREAS FROM MANATEE COUNTY
NORTHWARD. AFTER MIDNIGHT...ADDITIONAL RADIATION FOG AREAS WILL BE
DEVELOPING OVER NORTHERN AND CENTRAL LOCATIONS AWAY FROM THE
COAST...AND DOWN OVER THE SOUTHERN ZONES. IN THE END...IT ALL ADDS
UP TO A FORECAST OF ANOTHER FOGGY MORNING COMMUTE ON WEDNESDAY. THE
EVENING AND OVERNIGHT SHIFTS WILL CLOSELY MONITOR THE SITUATION AND
ISSUE DENSE FOG ADVISORIES AS NEEDED...IF NEEDED.
WEDNESDAY...THE MAIN SHORTWAVE ENERGY ALOFT WILL BE PASSING WELL TO
OUR NORTH...HOWEVER THE EVOLUTION OF THE MASS FIELDS WILL STILL
DAMPEN THE UPPER RIDGE OVER OUR HEADS. A WEAK COLD FRONT WILL BE
APPROACHING FROM THE PANHANDLE REGION DURING THE MORNING...REACHING
THE NATURE COAST FOR THE AFTERNOON...AND BE AROUND I-4...OR JUST
SOUTH OF THERE BY SUNSET. VERY LITTLE IN THE WAY OF UPPER LEVEL
FORCING WILL BE OVER US ON WEDNESDAY...LEAVING JUST THE LOW LEVEL
FOCUS ALONG AND AHEAD OF THE FRONT FOR LIFT. WITH THIS IN
MIND...WILL HAVE SCATTERED SHOWERS IN THE FORECAST...BUT DO NOT
ANTICIPATE MUCH ORGANIZATION TO THE SHOWERS...AND ONLY LIGHT
RAINFALL AMOUNTS. THE LACK OF REAL FORCING SUGGEST ALSO LEAVING ANY
THUNDER MENTION OUT OF THE FORECAST. WEDNESDAY DOES NOT LOOK LIKE A
WASHOUT. DEPENDING ON CLOUDS/FOG...THE ATMOSPHERIC POTENTIAL IS
QUITE WARM AHEAD OF THE FRONT...AND STILL HAVE AN ABOVE NORMAL DAY
IN TERMS OF TEMPERATURES AWAY FROM THE COAST. WITH ONSHORE FLOW AND
THE POTENTIAL FOR CONTINUED FOG NEAR THE COAST...TEMPS ARE LIKELY TO
BE CONSIDERABLY LOWER THAN INLAND BY EARLY TO MID AFTERNOON.
ONCE AGAIN...THE BIGGEST WEATHER FORECAST ISSUE FOR WEDNESDAY WILL
BE THE FOG. AHEAD OF THE FRONT...WINDS WILL BE SHIFTING SOUTH AND
SOUTHWEST...AS OPPOSED TO THE SOUTHEAST FLOW SEEN THE PAST FEW DAYS.
THIS DIRECTIONAL FLOW WILL FAVOR A CONTINUED ADVECTION OF SEA-FOG
ONTO COASTAL AREAS. SO...THE POTENTIAL EXISTS FOR A LONGER DURATION
OF LOWERED VISIBILITIES INTO THE DAY WEDNESDAY. SOME PORTIONS OF THE
COAST HAVE THE POTENTIAL FOR SEEING THE FOG FOR MUCH OF THE DAY. THE
COLD FRONTAL PASSAGE LATER WEDNESDAY/WED EVE WILL HELP
ALLEVIATE SOME OF THESE PROLONGED FOG ISSUES.
WEDNESDAY NIGHT...THE FRONT STALLS OVER SOUTH FLORIDA WITH SOME
SLIGHTLY DRIER AND COOLER AIR ARRIVING FROM THE NORTH. THIS IS NOT A
STRONG FRONT AND WILL NOT HAVE THE IMPACT THAT SOME OF THE FRONTS
HAD DURING PREVIOUS WEEKS. THE BIGGEST COOL DOWN WILL BE SEEN ON THE
NATURE COAST WHERE UPPER 40S TO 50S WILL BE COMMON. SOUTH OF THE I-4
CORRIDOR...STILL GOING WITH LOW TO MID 60S. LOOKS LIKE WEDNESDAY
NIGHT WILL BE A BRIEF BREAK IN THE SHOWER CHANCES.
THURSDAY/THURSDAY NIGHT...
A GENERALLY CLOUDY PATTERN FOR THURSDAY WITH A FEW LIGHT SHOWERS
POSSIBLE. THERE IS NOT MUCH IN THE WAY OF FORCING OVERHEAD. REALLY
THE ONLY THING FOUND IS SOME WEAK ISENTROPIC UPGLIDE BETWEEN
295-305K...AND SOME WEAK DIVERGENCE/DIFFLUENCE ALOFT WITHIN THE RRQ
OF AN EAST COAST JET STREAK. BOTH OF THESE FORCING MECHANISMS ARE
WEAK...AND HENCE WILL KEEP POPS IN THE CHANCE RANGE. THERE IS PLENTY
OF COLUMN MOISTURE AVAILABLE TO INTERACT WITH THIS WEAK LIFT TO
SUPPORT THE OCCASIONAL SHOWER...ESPECIALLY FOR THE NATURE
COAST...BUT RAIN FALL AMOUNTS WILL BE LIGHT ONCE AGAIN...WITH MUCH
OF THE DAY AND NIGHT JUST OVERCAST.
&&
.LONG TERM (THURSDAY NIGHT-TUESDAY)...
MEDIUM RANGE GUIDANCE IS IN FAIRLY GOOD AGREEMENT THROUGH THE LONG
TERM PERIODS...WITH ONLY SOME MINOR TIMING AND POSITIONING
DIFFERENCES NOTED WITH RESPECT TO SYNOPTIC FEATURES. A FRONTAL
BOUNDARY IS EXPECTED TO STALL OUT ACROSS CENTRAL FLORIDA THURSDAY
NIGHT AND REMAIN NEARLY STATIONARY THROUGH FRIDAY. THE CANADIAN IS
THE MOST AGGRESSIVE WITH THE FRONT AND PUSHES IT INTO SOUTH FLORIDA
BEFORE ALLOWING IT TO STALL OUT. THE GFS AND ECMWF ON THE OTHERHAND
ARE IN REASONABLY GOOD AGREEMENT SHOWING THE BOUNDARY STALLING OUT
THROUGH THE TAMPA BAY AREA AND WILL FOLLOW A BLEND OF THESE TWO
SOLUTIONS. THE BOUNDARY IS THEN EXPECTED TO LIFT BACK NORTHWARD AS A
WARM FRONT INTO NORTH FLORIDA FRIDAY NIGHT AND SATURDAY IN RESPONSE
TO SHORTWAVE ENERGY DIGGING INTO THE NATIONS MID-SECTION. THE
CANADIAN ONCE AGAIN KEEPS THE FRONTAL BOUNDARY MUCH FURTHER SOUTH
THAN EITHER THE GFS AND ECMWF...AND AS A RESULT WILL FOLLOW A
BLENDED GFS/ECMWF SOLUTION. THE SHORTWAVE ENERGY WILL CONTINUE TO
DIG INTO THE SOUTHEAST UNITED STATES SATURDAY NIGHT AND
SUNDAY...DRAGGING A SURFACE COLD FRONT THROUGH THE REGION ON SUNDAY.
AGAIN SOME MINOR TIMING DIFFERENCES ARE NOTED BETWEEN THE ECMWF AND
GFS...AND WILL HANDLE THESE AGAIN WITH A BLENDED APPROACH. MODEL
SOLUTIONS ARE THEN IN GOOD AGREEMENT SHOWING HIGH PRESSURE BUILDING
BACK INTO THE REGION EARLY NEXT WEEK.
&&
.AVIATION...
VFR CONDITIONS WILL CONTINUE THROUGH TODAY. EXPECT FOG TO BEGIN TO
REFORM OVER THE AREA BEGINNING BETWEEN 2Z AND 6Z WITH DENSE FOG
DEVELOPING BEFORE SUNRISE. FOG WILL LINGER OVER THE AREA THROUGH
AROUND 15Z BEFORE LIFTING. EXPECT THE UPCOMING FORECASTS TO TREND TO
MORE IFR CONDITIONS DURING THE EARLY MORNING HOURS. TERMINALS FROM
SRQ NORTHWARD WILL SEE VCSH BEGINNING AT 15Z AS A FRONT PUSHES INTO
THE STATE. LIGHT AND VARIABLE WINDS OVERNIGHT WILL TRANSITION TO
SOUTHWEST WINDS AT AROUND 10 KT BY THE LATE MORNING.
&&
.MARINE...
DENSE FOG CONTINUES OVER PORTIONS OF THE COASTAL WATERS...WITH
VISIBILITIES BELOW ONE MILE FREQUENTLY EXPECTED IN FOG. A COLD FRONT
WILL APPROACH THE WATERS WEDNESDAY AFTERNOON AND MOVE THROUGH THE
WATERS WEDNESDAY NIGHT BEFORE STALLING ACROSS SOUTH FLORIDA...WITH A
CHANCE FOR RAIN FOR BOTH WEDNESDAY AND THURSDAY. WINDS MAY BRIEFLY
INCREASE TO AROUND 15 KNOTS BEHIND THE FRONT...BUT THE OTHERWISE THE
ONLY MARINE CONCERN THROUGH THE NEXT FEW DAYS WILL BE THE DENSE FOG
THROUGH AT LEAST THE FIRST PART OF WEDNESDAY.
&&
.FIRE WEATHER...
THE CURRENT RIDGE OF HIGH PRESSURE OVER THE REGION WILL RETREAT
EASTWARD AS A WEAK COLD FRONT APPROACHES FROM THE NORTHWEST TONIGHT.
THIS FRONT WILL SLOWLY PUSH SOUTH INTO THE REGION DURING WEDNESDAY
AND THEN STALL OVER SOUTH FLORIDA WEDNESDAY NIGHT. NO SIGNIFICANT
PUSH OF DRIER AIR IS EXPECTED BEHIND THIS FRONT AND NO CRITICAL
LEVELS OF RELATIVE HUMIDITY ARE ANTICIPATED THROUGH THE REMAINDER OF
THE WEEK.
FOG POTENTIAL...HIGH POTENTIAL FOR FOG THROUGH WEDNESDAY. FOG WILL
LIKELY CONTAIN DENSE PATCHES...ESPECIALLY NEAR THE COAST WHERE SEA
FOG WILL PERSIST.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 66 78 61 69 / 10 40 20 40
FMY 66 82 66 80 / 10 50 40 30
GIF 65 82 60 72 / 10 50 20 40
SRQ 65 75 63 71 / 10 40 20 40
BKV 62 80 57 68 / 10 40 20 40
SPG 65 75 62 69 / 10 40 20 40
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...DENSE FOG ADVISORY UNTIL 10 AM EST WEDNESDAY FOR
ENGLEWOOD TO TARPON SPRINGS OUT 20 NM-ENGLEWOOD TO TARPON
SPRINGS OUT 20 TO 60 NM-TARPON SPRINGS TO SUWANNEE RIVER
OUT 20 NM-TARPON SPRINGS TO SUWANNEE RIVER OUT 20 TO 60 NM.
&&
$$
SYNOPSIS/SHORT TERM/MARINE/FIRE WX...MROCZKA
LONG TERM...JELSEMA
AVIATION...BARREN
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
1055 AM EST TUE FEB 4 2014
.UPDATE...
15Z WATER VAPOR AND H4 RAP ANALYSIS SHOWING AN AMPLIFIED PATTERN
DEVELOPING ACROSS THE COUNTRY. THE MAIN FEATURE OF NOTE IS A DEEP
AND INCREASINGLY NEGATIVELY TILTED TROUGH THAT IS SWINGING OUT OVER
THE CENTRAL PLAINS FROM THE INTER-MOUNTAIN WEST. AT THE BASE OF THIS
TROUGH WE FIND A STRONG SHORTWAVE AND ASSOCIATED STRONG UPPER JET
EJECTING EASTWARD ACROSS THE SOUTHERN PLAINS. THIS FEATURE AND IT
CYCLOGENESIS REFLECTION AT THE SURFACE WILL/IS SPREADING WINTRY
PRECIPITATION ACROSS A VAST STRETCH OF THE CENTRAL
PLAINS/MIDWEST...AND NORTHEAST TODAY THROUGH WEDNESDAY. THIS WINTRY
WEATHER IS FAR REMOVED FROM THE CONDITIONS OVER THE FLORIDA
PENINSULA...WHERE THE DEEPENING TROUGH/HEIGHT FALLS TO OUR WEST HAVE
ACTUALLY HELPED TO AMPLIFY THE RIDGE IN PLACE OVER OUR HEADS. THE
STACKED HIGH PRESSURE WILL CONTINUE TO ALLOW FOR ABOVE NORMAL
TEMPERATURES TODAY AND TONIGHT...AND ALSO CONTINUE OUR ISSUES WITH
DENSE OVERNIGHT AND EARLY MORNING FOG.
THE 04/12Z KTBW SOUNDING PROFILE SHOWS THE INFLUENCE OF THE RIDGE
WITH A DEFINED SUBSIDENCE INVERSION AROUND 650MB. A FAIRLY MOIST
COLUMN EXISTS BENEATH THIS INVERSION.
AT THE SURFACE...A GENERALLY LIGHT SOUTHEAST FLOW IN PLACE ON THE
FAR SOUTHERN PERIPHERY OF HIGH PRESSURE RIDGING DOWN THE EASTERN
SEABOARD. WELL TO OUR WEST WE FIND A DEVELOPING FRONTAL WAVE THAT
WILL PASS WELL TO OUR NORTH TONIGHT AND DRAG A WEAK COLD FRONT INTO
THE REGION LATER WEDNESDAY AND WEDNESDAY NIGHT. MUCH OF THE DENSE
FOG SEEN EARLIER THIS MORNING HAS LIFTED. STILL SOME PATCHES OF
DENSER FOG AROUND PINELLAS COUNTY WITH THE FLOW OFF TAMPA BAY...BUT
EVEN THESE AREAS SHOULD SEE SIGNIFICANT IMPROVEMENT AS WE GO INTO
THE MIDDAY HOURS. ELSEWHERE A MIX OF SUN AND CLOUDS IS IN PLACE WITH
TEMPERATURES CLIMBING THROUGH THE 70S SOUTH AND 60S NORTH.
REST OF TODAY AND TONIGHT...
A WARM AND PARTLY SUNNY FORECAST LOOKS ON TAP FOR MOST AREAS AS WE
HEAD THROUGH THE AFTERNOON. MOST HI-RES GUIDANCE SOLUTIONS
ANTICIPATE ENOUGH TERRESTRIAL WARMING TO ALLOW FOR SEA-BREEZE
DEVELOPMENT NEAR THE COAST. THIS DEVELOPING ONSHORE FLOW WILL ACT TO
COOL AREAS NEAR THE IMMEDIATE COAST FOR LATER THIS AFTERNOON AS THE
AIR SOURCE IS OVER THE SHELF WATERS. HOWEVER...INLAND UPPER 70S
NORTH AND LOWER 80S SOUTH DOES NOT SEEM UNREASONABLE.
THE FORECAST CONCERN FOR TONIGHT IS THE ADVECTION/RE-DEVELOPMENT OF
DENSE FOG. WITH THE RIDGE OVERHEAD AND LITTLE CHANGE IN THE OVERALL
SYNOPTIC SITUATION...A PERSISTENCE FORECAST OF ANOTHER ROUND OF FOG
IS THE BEST WAY TO GO. ALTHOUGH MOST AREAS WILL BE GENERALLY FOG
FREE LATE THIS AFTERNOON/EARLY EVENING...THE SEA-BREEZE AND LOSS OF
MIXING SHOULD ALLOW SEA-FOG RE-DEVELOPMENT/ADVECTION FROM THE
COASTAL WATERS...ONTO THE COAST FROM MANATEE COUNTY NORTHWARD
THROUGH PINELLAS COUNTY AND THE NATURE COAST. WITH SUNSET...AN
EXPANSION INLAND OF THIS FOG IS ANTICIPATED. TIMING AND FORECASTING
DENSE FOG IN GENERAL IS...DIFFICULT...TO SAY THE LEAST. DID A
LOGICAL PROGRESSION INLAND THROUGH THE EVENING THAT IS SIMILAR TO
WHAT OCCURRED MONDAY NIGHT. AFTER MIDNIGHT...ADDITIONAL RADIATION
FOG AREAS WILL BE DEVELOPING OVER LOCATIONS AWAY FROM THE COAST. IT
ALL ADDS UP TO A FORECAST OF ANOTHER FOGGY MORNING COMMUTE ON
WEDNESDAY. THE EVENING AND OVERNIGHT SHIFTS WILL CLOSELY MONITOR THE
SITUATION AND ISSUE DENSE FOG ADVISORIES AS NEEDED...IF NEEDED.
WEDNESDAY...
THE MAIN SHORTWAVE ENERGY ALOFT WILL BE PASSING WELL TO OUR
NORTH...HOWEVER THE EVOLUTION OF THE MASS FIELDS WILL STILL DAMPEN
THE UPPER RIDGE OVER OUR HEADS. A WEAK COLD FRONT WILL BE
APPROACHING FROM THE PANHANDLE REGION DURING THE MORNING...REACHING
THE NATURE COAST FOR THE AFTERNOON...AND BE AROUND I-4...OR JUST
SOUTH OF THERE BY SUNSET. VERY LITTLE IN THE WAY OF UPPER LEVEL
FORCING WILL BE OVER US ON WEDNESDAY...LEAVING JUST THE LOW LEVEL
FOCUS ALONG AND AHEAD OF THE FRONT FOR LIFT. WITH THIS IN
MIND...WILL HAVE SCATTERED SHOWERS IN THE FORECAST WORKING NORTH TO
SOUTH ON WEDNESDAY...BUT DO NOT ANTICIPATE MUCH ORGANIZATION TO THE
SHOWERS...AND ONLY LIGHT RAINFALL AMOUNTS. THE LACK OF REAL FORCING
SUGGEST ALSO LEAVING ANY THUNDER MENTION OUT OF THE FORECAST.
ONCE AGAIN...THE BIGGEST WEATHER FORECAST ISSUE WILL BE THE FOG.
AHEAD OF THE FRONT...WINDS WILL BE SHIFTING SOUTH AND SOUTHWEST...AS
OPPOSED TO THE SOUTHEAST FLOW SEEN THE PAST FEW DAYS. THIS
DIRECTIONAL FLOW WILL FAVOR A CONTINUED ADVECTION OF SEA-FOG ONTO
COASTAL AREAS. SO...THE POTENTIAL EXISTS FOR A LONGER DURATION OF
LOWERED VISIBILITIES INTO THE DAY WEDNESDAY. SOME PORTIONS OF THE
COAST HAVE THE POTENTIAL FOR SEEING THE FOG FOR MUCH OF THE DAY. THE
COLD FRONTAL PASSAGE WEDNESDAY NIGHT WILL HELP ALLEVIATE SOME OF
THESE PROLONGED FOG ISSUES.
&&
.AVIATION...
VSBY CONTINUES TO IMPROVE ACROSS THE AREA THIS MORNING. EXPECT VFR
CONDITIONS TO SET IN AND PERSIST THROUGH THE DAY TODAY. WINDS WILL
BECOME MORE SOUTHERLY OVERNIGHT HELPING TO AGAIN SHIFT SEA FOG OVER
THE TERMINALS. EXPECT FOG TO PERSIST THROUGH 12Z TOMORROW MORNING.
&&
.MARINE...
DENSE FOG CONTINUES OVER PORTIONS OF THE COASTAL WATERS...WITH
VISIBILITIES BELOW ONE MILE FREQUENTLY EXPECTED IN FOG. A COLD FRONT
WILL APPROACH THE WATERS WEDNESDAY AFTERNOON AND MOVE THROUGH THE
WATERS WEDNESDAY NIGHT BEFORE STALLING ACROSS SOUTH FLORIDA...WITH A
CHANCE FOR RAIN FOR BOTH WEDNESDAY AND THURSDAY. WINDS MAY BRIEFLY
INCREASE TO AROUND 15 KNOTS BEHIND THE FRONT...BUT THE OTHERWISE THE
ONLY MARINE CONCERN THROUGH THE NEXT FEW DAYS WILL BE THE DENSE FOG
THROUGH AT LEAST THE FIRST PART OF WEDNESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 81 67 78 63 / 10 10 40 30
FMY 86 68 83 66 / 20 10 50 20
GIF 84 66 82 63 / 20 10 40 30
SRQ 81 65 78 63 / 20 10 40 20
BKV 83 62 80 59 / 10 10 40 30
SPG 80 66 78 63 / 10 10 40 30
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...DENSE FOG ADVISORY UNTIL 10 AM EST WEDNESDAY FOR
ENGLEWOOD TO TARPON SPRINGS OUT 20 NM-ENGLEWOOD TO TARPON
SPRINGS OUT 20 TO 60 NM-TARPON SPRINGS TO SUWANNEE RIVER OUT
20 NM-TARPON SPRINGS TO SUWANNEE RIVER OUT 20 TO 60 NM.
DENSE FOG ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR TAMPA
BAY WATERS.
&&
$$
UPDATE...MROCZKA
AVIATION...BARREN
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
1040 AM EST TUE FEB 4 2014
.DISCUSSION...
FRONTAL BOUNDARY SPANNING THE N COAST OF THE GOMEX HAS BEEN HALTED
BY THE SFC/LOW LVL HI PRES RIDGE EXTENDING FROM BERMUDA TO THE BAY
OF CAMPECHE. THE RIDGE IS GENERATING A DEEP S/SERLY FLOW ACRS
CENTRAL FL WHICH IS TAPPING A MOIST LOW LVL AIRMASS OVER THE NRN
BAHAMAS AND THE FL STRAITS. LATEST RUC ANALYSIS INDICATES UPSTREAM
H100-H85 MEAN RH VALUES BTWN 75-90PCT. PWATS BTWN 1.2"-1.3" OFF THE
MORNING RAOB MAY APPEAR ON THE LOW SIDE...BUT MOST OF THIS MOISTURE
IS TRAPPED BLOW A TIGHT SUBSIDENCE INVERSION IN THE H70-H50 LYR.
DYNAMICALLY SPEAKING...THE AIRMASS IS RATHER TORPID WITH NO SIG MID
LVL VORTICITY/UPR LVL DIVERGENCE NOTED ACRS THE REGION. H85-H70
LAPSE RATES OVER SW FL APPROACHING AN IMPRESSIVE 8C/KM...BUT ARE
TRAPPED UNDER THE AFOREMENTIONED SUBSIDENCE INVERSION AND COLOCATED
WITH THE A POCKET OF RELATIVELY DRY LOW LVL AIR WITH MEAN RH VALUES
BLO 70PCT. FURTHERMORE...STREAMLINE ANALYSIS THRU THE H100-H70 LYR
SUGGESTS THIS FEATURE WILL REMAIN OVER THE W FL PENINSULA THIS AFTN.
HI MOISTURE THRU THE H100-H70 LYR WILL REQUIRE SOME MENTION OF
PRECIP AREAWIDE...ESPECIALLY AS THE SRLY FLOW HELPS PUSH AFTN TEMPS
INTO THE L/M80S WITH SFC DEWPOINTS INTO THE M/U60S. HOWEVER...THE
LACK OF INSTABILITY WILL REQUIRE BOUNDARY INTERACTION TO SPARK ANY
SHRA ACTIVITY...AND THE PREVAILING DEEP SRLY FLOW DOES NOT SUPPORT A
SEABREEZE MERGER. RADAR HAS PICKED UP BRIEF ISOLD SHRAS ALONG THE
COAST AND DOWNWIND OF THE NRN BAHAMAS...BUT NEITHER RADAR NOR SAT
TRENDS SUGGEST ANYTHING MORE THAN THIS LATER TODAY.
&&
.AVIATION...
N OF KISM-KDAB: S/SE SFC WND BLO 8KTS BCMG S/SW AFT 05/06Z. THRU
04/16Z...AREAS IFR/LCL LIFR CIGS/VSBYS IN FG AND LOW STRATUS BCMG
VFR. BTWN 04/16Z-05/03Z...SLGT CHC MVFR SHRAS. AFT 05/08Z...PTCHY
MVFR/LCL IFR VSBYS IN BR.
S OF KISM-KDAB: E/SE SFC WND AOB 10KTS. THRU 04/17Z...AREAS MVFR
CIGS BTWN FL015-025 WITH BRIEF ISOLD IFR SHRAS. BTWN
04/17Z-05/00Z...SLGT CHC MVFR SHRAS. AFT 05/08Z...PTCHY MVFR/LCL IFR
VSBYS IN BR W OF KTIX-KOBE.
&&
.MARINE...
WEAK FRONTAL BOUNDARY DRAPED ACRS THE FL PANHANDLE KEEPING THE RIDGE
OF THE SFC/LOW LVL ATLC TROF SUPPRESSED OVER THE S HALF OF THE FL
PENINSULA. FAVORABLE BOATING CONDITIONS OVERALL AS DATA BUOYS/C-MAN
NETWORK REPORTING A GENTLE TO MODERATE SERLY BREEZE WITH SEAS 2-3FT
NEARSHORE...3-4FT OFFSHORE WITH DOMINANT PDS ARND 10SEC AREAWIDE.
WINDS OFFSHORE N OF SEBASTIAN INLET MAY BRIEFLY REACH THE 15-20KT
RANGE THIS AFTN AS A RELATIVELY TIGHT PGRAD IS LURKING OVER THE
BAHAMA BANK/GREATER ANTILLES...BUT OVERALL NO SIG CHANGES EXPECTED
AS THE FRONT TO THE N APPEARS TO HAVE MADE ITS FURTHEST PENETRATION.
WAVE MODELS CONTINUE TO RUN ABOUT A FOOT ABV LATEST OBS...BUT
SUSPECT AN ERLY BACKGROUND SWELL WILL KEEP SEAS SLIGHTLY ELEVATED IN
THE OPEN ATLANTIC...UP TO 4FT NEARSHORE AND 5FT OFFSHORE.
&&
.CLIMATE...RECORD HIGHS TODAY AND TOMORROW...
TUE 2/4 WED 2/5
DAYTONA BEACH 87/1990 86/1989
ORLANDO (MCO) 86/1990 87/1982
MELBOURNE 86/1990 87/2011
VERO BEACH 87/1989 86/1986
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...BRAGAW
LONG TERM/IMPACT WX...VOLKMER
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1223 PM EST TUE FEB 4 2014
.SYNOPSIS...
ISSUED AT 1153 AM EST TUE FEB 4 2014
A WINTER STORM WILL BEGIN TO IMPACT THE REGION BY THIS EVENING AND
CONTINUING INTO WEDNESDAY. SNOW WILL OVERSPREAD THE AREA FROM
SOUTHWEST TO NORTHEAST DURING THE AFTERNOON AND EVENING HOURS. THE
SNOW WILL CONTINUE INTO MIDDAY WEDNESDAY WITH HEAVY SNOW EXPECTED
OVER MUCH OF THE AREA. IN ADDITION... BLOWING AND DRIFTING SNOW
WILL DEVELOP...ESPECIALLY IN OPEN AND RURAL AREAS.
&&
.UPDATE...
ISSUED AT 1153 AM EST TUE FEB 4 2014
ONLY MINOR CHANGES MADE TO GRIDS FOR THIS AFTERNOON. SNOWSTORM STILL
LOOKS ON TARGET FOR OUR AREA... THOUGH BASED ON CURRENT
OBSERVATIONS AND LATEST RAP FCSTS SUSPECT ONSET MAY BE DELAYED A
BIT. LOWERED HOURLY POPS ACROSS THE CWA FOR MUCH OF THIS AFTN TO
REFLECT THIS BUT OVERALL THIS HAS LITTLE IMPACT ON THE FORECAST
WITH SNOW STILL EXPECTED TO OVERSPREAD MOST OF THE AREA BY 7PM.
12Z MODELS... ESPECIALLY THE NAM... HAVE TRENDED TOWARD A LITTLE
MORE INTENSE SYSTEM WITH HIGHER QPF/SNOWFALL TOTALS. IN GENERAL
THIS TREND IS ALREADY REFLECTED IN GOING GRIDS WITH POTENTIAL
6-10INCHES OVER SE PORTION OF THE CWA TAPERING OFF TO 3-6 INCHES
NW, SO NO CHANGES PLANNED TO SNOWFALL ACCUMS ATTM.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 455 AM EST TUE FEB 4 2014
ENTIRE FOCUS ON UPGRADE/HEADLINE DELINEATION THIS AM. INITIAL
CONCERN REVOLVED AROUND DOWNTREND IN QPF ESPCLY NAM AS EVENT
DRAWS NIGH. CROSS CHECK OF MODEL SIGNALS HOWEVER CONT TO SUPPORT
AT LEAST LOW END WARNING EVENT FOR ALL BUT FAR NWRN QUARTER OR SO
OF CWA...WITH ADDNL FACTORS SUCH AS...AM COMMUTE/BLSN/DRIFTING TO
LIKELY PROVIDE UPTICK/EXTENSION OF IMPACTS. OVERALL FAIR AGREEMENT
BTWN SREF MEAN AND NAM COBB OUTPUT...WITH TREND FOCUSING WIDE BAND
ROUGHLY ALONG/SE OF 24 CORRIDOR. COLLOCATION OF STATIC
INSTABILITY/SATURATED DGZ/CONVECTIVE INSTABILITY POCKETS
ALOFT...AS UPPER LEVEL JET STREAK ACRS FAR SERN CAN GTE 180 KTS
THIS EVENING TO LIKELY AID IN FGEN RESPONSE WITH BANDED TRANSIENT
ENHANCEMENTS THIS EVENING INTO ERLY TONIGHT. WEAK TROWAL SIGNATURE
AT I290K WITH TRANSITORY AGEO VERT CIRCULATION ENHANCEMENTS PER
TIME/HGHT XSCTIONS SUGGEST FOCUSED BANDING WSW-ENE WELL NW OF
COMMA HEAD OCCLUSAL. ADDITIONALLY...IMR/GARCIA METHODOLOGY
SUPPORTS FULL STEAM AHEAD AS GENEROUS 4 G/KG ON I290K SFC PIVOTS
THROUGH FAR SERN CWA IN 03-09 UTC WED TIMEFRAME WITH 3 G/KG
CONSISTENTLY INTO ROUTE 24 CORRIDOR DURING SAME TIMEFRAME. PWAT
VALUES OF 2SD ABOVE NORMAL PROVIDING SIGNIFICANT BULK MSTR ESPCLY
IN CONSIDERATION OF COLD AIRMASS IN PLACE. SOME INIT CONCERN WRT
DRY AIR ENTRAINMENT...BUT PATTERN RECOGNITION WOULD SUGGEST THIS
TO BE RATHER WEAK/QUITE SHALLOW...RESULTING IN A SHORT
LIVED/BASICALLY A 60-90 MINUTE DLAY OF SNOWFALL ONSET AS SFC
ANTICYCLONE OVHD/STREWN E-W THROUGH SRN GRTLKS RGN...RATHER THAN
LAKE HUR/SRN ONT THAT COULD BE QUITE EROSIVE. GIVEN MESOSCALE
POTNL/MAGNITUDE OF MSTR/DEEP LYR MFLUX CONVERGENCE...WL ERR A BIT
TO HIR SIDE 6-10 SERN THIRD TIERED TO 3-6 FAR NWRN IN ADV...WITH
LESSER 5-8 ACCUM/WARNING SECTION IN BTWN.
&&
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 455 AM EST TUE FEB 4 2014
A BROAD UPPER LEVEL TROF WILL PERSIST OVER CENTRAL NORTH
AMERICA THIS PERIOD AS CROSS POLAR FLOW CONTINUES. NOTHING TO
BREAK THIS COLD PATTERN WITH TEMPERATURES REMAINING WELL BELOW
NORMAL FOR THIS TIME OF YEAR. A WEAK UPPER LEVEL TROF WILL MOVE
ACROSS THE WESTERN GREAT LAKES REGION THIS WEEKEND...BUT LIMITED
UPPER LEVEL SUPPORT AND LIMITED MOISTURE SHOULD KEEP ANY SNOW
AMOUNTS LIGHT. FOR NOW...LEFT LOW CHANCES FOR SNOW FOR A NUMBER OF
PERIODS THIS WEEKEND...BUT SUBSEQUENT SHIFTS SHOULD BE ABLE TO
REFINE THE TIMING BETTER. OTHERWISE...HAVE TRENDED TEMPS DOWN MOST
PERIODS IN LINE WITH THE ECMWF...GFS AND CANADIAN GEM. ONE THIRD
OF THE DAYS AT FT WAYNE SO FAR THIS YEAR HAVE HAD LOWS BELOW
ZERO...SO THE LATEST GFS/MEX MOS WITH MOST LOWS AROUND ZERO TO -9
APPEAR ON TRACK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1153 AM EST TUE FEB 4 2014
LITTLE CHANGE TO 12Z TAFS. DELAYED START OF SNOW AT FWA
SLIGHTLY... BUT STILL EXPECT MODERATE SNOW FALLING BY THIS EVE.
IFR CONDITIONS EXPECTED AT BOTH TERMINALS OVERNIGHT WITH LOWEST
CONDITIONS... HIGHEST SNOWFALL ACCUMS AT FWA. SNOW IN DEFORMATION
ZONE AS LOW MOVES AWAY SHOULD PERSIST THROUGH WED MORNING AND
COMBINED WITH INCREASING NORTH WINDS HELP KEEP VSBYS IN IFR RANGE
THROUGH THE END OF THE PERIOD.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WARNING UNTIL 4 PM EST /3 PM CST/ WEDNESDAY FOR
INZ005>009-012>018-020-022>027-032>034.
WINTER WEATHER ADVISORY UNTIL 4 PM EST /3 PM CST/ WEDNESDAY FOR
INZ003-004.
MI...WINTER STORM WARNING UNTIL 4 PM EST WEDNESDAY FOR MIZ079>081.
WINTER WEATHER ADVISORY UNTIL 4 PM EST WEDNESDAY FOR MIZ077-078.
OH...WINTER STORM WARNING UNTIL 4 PM EST WEDNESDAY FOR OHZ001-002-004-
005-015-016-024-025.
LM...NONE.
&&
$$
UPDATE...JT
SYNOPSIS...JT
SHORT TERM...MURPHY
LONG TERM...SKIPPER
AVIATION...JT
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WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1141 PM CST MON FEB 3 2014
.SHORT TERM /TONIGHT/...
ISSUED AT 316 PM CST MON FEB 3 2014
CONDITIONS WILL REMAIN QUIET AND SEASONABLY WARM THROUGH THE EVENING
HOURS AS SURFACE HIGH PRESSURE SHIFTS OFF TO THE EAST INTO NORTHERN
ILLINOIS. A ZONALLY ORIENTED RIDGE EXTENDING FROM THE CANADIAN
ROCKIES INTO MINNESOTA WILL STRENGTHEN DURING THE OVERNIGHT HOURS
AND CAUSE WINDS TO BACK TO THE EAST BY 12Z TUESDAY AS THE COL
BETWEEN THESE TWO HIGHS TRANSECTS THE STATE. THESE EASTERLY WINDS
WILL HELP MAINTAIN A WEDGE OF DRY AIR BELOW 800 MB THROUGH THE
OVERNIGHT HOURS AS REFLECTED IN THE 12Z/18Z NAM AND 18Z RAP BUFR
SOUNDINGS FOR ALMOST ALL OF THE CWA.
THE LATEST SYNOPTIC GUIDANCE HAS ALSO SLOWED THE ARRIVAL OF OUR NEXT
WINTER STORM TOMORROW MORNING BY ABOUT 4-6 HOURS...WHICH ISN`T
SURPRISING GIVEN THE AMPLITUDE OF THE UPPER LEVEL LONGWAVE TROUGH AS
IT MOVED INLAND OVER CALIFORNIA LAST NIGHT. THE 300 MB WAVE WILL
EJECT OUT OF THE FOUR CORNERS REGION AFTER 06Z AND BECOME NEGATIVELY
TILTED...BUT DISJOINTED FROM THE MAIN UPPER LEVEL TROUGH...AS IT
REACHES THE TEXAS PANHANDLE AT 12Z. VISIBLE SATELLITE IMAGERY SHOWS
MOISTURE ALREADY POOLING OVER WESTERN KANSAS AND NEBRASKA OUT
AHEAD OF THE WAVE...WHICH WILL SPREAD EASTWARD INTO THE CWA AFTER
06Z.
PREVIOUS MODEL RUNS HAD A BAND OF LIGHT SNOW LIFTING NORTH AND EAST
ACROSS THE CWA OVERNIGHT IN CONJUNCTION WITH A RIBBON OF 800-850
MB FRONTOGENESIS OUT AHEAD OF THE MAIN STORM. THE NAM IN
PARTICULAR HAS GREATLY BACKED OFF ON THE OVERNIGHT QPF...MOSTLY
DUE TO THE PRESENCE OF THE AFOREMENTIONED LOW LEVEL DRY LAYER. IN
FACT...THE QPF THAT IS BEING GENERATED BY THE NAM MAY JUST BE AN
ARTIFACT OF PREVIOUS MODEL RUNS AND COULD VANISH BY THE 00Z RUN.
THE GFS 280K ANALYSIS ALSO AGREES WITH THIS THINKING. DESPITE
SHARP ASCENT FROM 880 TO 800 MB OVER THE SOUTHWEST CWA...MOISTURE
REMAINS LIMITED WITH CDEFS RANGING ANYWHERE FROM 50 TO 150 MB.
THUS...THE FORECAST CHALLENGE FOR THE OVERNIGHT PERIOD REVOLVED
AROUND WHETHER THE LOW LEVEL DRY AIR WILL WIN OUT OVER THE
OVERRUNNING MOISTURE PLUME. HAVE TRENDED TOWARDS THE NAM IN BACKING
OFF ON POPS SUBSTANTIALLY...AND THIS TREND WILL NEED TO BE MONITORED
DURING THE OVERNIGHT HOURS.
.LONG TERM /TUESDAY THROUGH MONDAY/...
ISSUED AT 316 PM CST MON FEB 3 2014
THE WINTER STORM FOR TUESDAY AND TUESDAY NIGHT IS AN INTERESTING
STORM ON MANY LEVELS. IT WILL BRING WITH IT SEVERAL ELEMENTS OF A
WINTER STORM...SNOW THEN WIND FOLLOWED BY BITER COLD. LIGHT SNOW
WILL BE ONGOING FROM A WEAK WAVE THAT COMES THROUGH TONIGHT. THERE
ARE SOME QUESTIONS REMAINING FOR TUESDAY MORNING AS TO HOW QUICKLY
WE CAN SATURATE THE ATMOSPHERE AND HOW FAR SOUTH THAT WILL OCCUR.
THERE IS ALSO UNIMPRESSIVE FORCING IN THE DENDRITIC LAYER THROUGH
18Z OVER ALL BUT THE FAR SOUTHERN FORECAST AREA.
BY TUESDAY AFTERNOON INTO THE EVENING HOWEVER A SHORTWAVE LIFTS OUT
OF THE SOUTHERN PLAINS AND INTO THE UPPER MIDWEST...NEAR THE IOWA
MISSOURI BORDER. THE ATMOSPHERE WILL QUICKLY SATURATE IN THE
AFTERNOON WHILE DECENT FORCING LIFTS ACROSS THE SOUTHERN PORTION OF
THE FORECAST AREA. AFTER SOME LIGHT SNOW EARLY IN THE MORNING
FOLLOWED BY A BIT OF A BREAK...SNOW SHOULD BEGIN AGAIN IN THE
AFTERNOON AND BECOME MODERATE AT TIMES... ESPECIALLY AFTER 3 PM.
ONE CONCERN IS THAT MOST OF THE FORCING THAT OCCURS HAPPENS ABOVE
THE DENDRITIC LAYER AND WE STILL HAVE SOME ISSUES WITH SATURATION AT
18Z. BY 21Z THOUGH WE SATURATE TO AT LEAST 700 MB AND SOME FORCING
DOES MAKE IT DOWN INTO THE DENDRITIC LAYER RESULTING IN A PERIOD OF
MODERATE SNOWFALL ACROSS SOUTHERN IOWA. THE BEST AREA TO SEE THIS
IS THE SOUTHERN TWO TIERS OF COUNTIES. AS YOU GO TOWARDS THE I-80
CORRIDOR THE FORCING IS NOT AS GOOD FOR AS LONG A PERIOD OF TIME
BUT SUFFICIENT FOR SEVERAL INCHES OF SNOW.
AS COLDER AIR WORKS INTO THE AREA SNOWFALL RATIOS WILL MOVE FROM
ABOUT 14 TO 1 CLOSER TO 18 OR 19 TO 1. THIS WILL HELP GIVE HIGHER
SNOWFALL TOTALS AND THE SNOW SHOULD BE FLUFFY AND EASILY BLOWN
AROUND.
THIS SYSTEM WILL ALSO HAVE WIND WITH IT BUT AGAIN THE WIND WILL NOT
BE EXTREMELY STRONG NOR WILL IT BE COINCIDENT WITH THE BEST
SNOWFALL. SO WHILE NOT A PERFECT SITUATION IT SHOULD STILL BE
SUFFICIENT TO PRODUCE DANGEROUS TRAVEL... ESPECIALLY FAR SOUTH. UP
TOWARDS THE I-80 CORRIDOR CONDITIONS ARE STILL GOOD BUT NOT AS GOOD
AS FURTHER SOUTH. WINDS WILL INCREASE BETWEEN 4 AND 6 PM AND BY
THAT TIME THERE SHOULD BE 2 TO 3 INCHES ON THE GROUND. SINCE TRAVEL
IMPACTS FROM THIS SYSTEM ARE POTENTIALLY DANGEROUS AS IT WILL HAPPEN
DURING THE EVENING COMMUTE I HAVE PUT THE WINTER STORM WARNING UP TO
THE I-80 CORRIDOR. WE WILL CONTINUE TO EVALUATE TO SEE IF SNOWFALL
AMOUNTS PAN OUT BUT AT THIS POINT IN TIME CONFIDENCE IS HIGH FOR
SEVERAL INCHES OF SNOW ALONG WITH INCREASING WIND DURING THE DRIVE
HOME WARRANTING THE WINTER STORM WARNING.
LOCATIONS FURTHER NORTH WILL SEE LESS SNOWFALL BUT WILL STILL SEE
BRISK WINDS AND COLD TEMPS. IN FACT WE WILL LIKELY BE DEALING WITH
WIND CHILL ISSUES BEYOND THE WINTER STORM. I HAVE ISSUED A WINTER
WEATHER ADVISORY FOR LOCATIONS BETWEEN HIGHWAY 20 AND HIGHWAY 30.
THESE AREAS WILL GENERALLY SEE BETWEEN 2 AND 4 INCHES OF SNOW AND
COMBINED WITH SOME WIND I WOULD EXPECT TO SEE AT LEAST SOME TRAVEL
ISSUES ESPECIALLY IN OPEN AREAS LATER IN THE AFTERNOON AND EVENING.
BEYOND TUESDAY...MID WEEK WILL BE BITTER COLD WITH SUB ZERO LOWS AND
SINGLE DIGIT HIGHS. BY FRIDAY A STORM SYSTEM TAKING SHAPE OVER THE
SOUTHWEST WILL PRODUCE A MORE ZONAL FLOW ACROSS THE MIDWEST AND
TEMPERATURES...WHILE STILL COLD...WILL MODERATE INTO THE TEENS.
NONE OF THE MODELS NOW MATURE THIS INTO A CLOSED LOW BUT THEY STILL
VARY ON THE INTENSITY OF THE WAVE AND THUS TIMING ISSUES ARISE AS
THE MORE DIGGING THAT OCCURS THE SLOWER THE WAVE LIFTS OUT. THE GFS
IS STILL THE MOST BULLISH IN BRINGING PRECIP THIS FAR NORTH WHILE
THE EURO KEEP IT FURTHER SOUTH. FOR NOW I KEEP THE CHANCE POPS GOING
FOR THE START OF THE WEEKEND.
&&
.AVIATION...04/06Z
ISSUED AT 1128 PM CST MON FEB 3 2014
-SN BEGINNING TO PUSH INTO SOUTHERN IOWA WILL BEGIN TO AFFECT
WESTERN SITES KFOD/KDSM NEAR 12Z...BEFORE LIFTING INTO OTHER SITES
THROUGH THE AFTERNOON. CONDITIONS WILL DROP TO MVFR OR IFR WITH
-SN THOUGH THERE MAY BE A BREAK IN -SN FOR A FEW HOURS TUESDAY.
CONDITIONS MAY DROP TO LIFR AT TIMES. WINDS WILL SHIFT TO THE
NORTH LATE IN PERIOD AND WILL INCREASE AFTER 18Z. WINDS AND SN
WILL KEEP CONDITIONS MVFR OR IFR THROUGH REMAINDER OF PERIOD.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING FROM NOON TUESDAY TO 6 AM CST WEDNESDAY FOR
ADAIR-CASS-DALLAS-GUTHRIE-JASPER-MADISON-MAHASKA-MARION-POLK-
POWESHIEK-WARREN.
WINTER WEATHER ADVISORY FROM NOON TUESDAY TO 6 AM CST WEDNESDAY
FOR AUDUBON-BLACK HAWK-BOONE-CALHOUN-CARROLL-CRAWFORD-GREENE-
GRUNDY-HAMILTON-HARDIN-MARSHALL-SAC-STORY-TAMA-WEBSTER.
WINTER STORM WARNING FROM 9 AM TUESDAY TO 6 AM CST WEDNESDAY FOR
ADAMS-APPANOOSE-CLARKE-DAVIS-DECATUR-LUCAS-MONROE-RINGGOLD-
TAYLOR-UNION-WAPELLO-WAYNE.
&&
$$
SHORT TERM...SKOW
LONG TERM...FAB
AVIATION...AWB
AREA FORECAST DISCUSSION
NWS GOODLAND KS
951 PM MST MON FEB 3 2014
.UPDATE...
ISSUED AT 905 PM MST MON FEB 3 2014
CURRENTLY FINISHING AN UPDATE TO THE FORECAST. MODELS AND CURRENT
WSR-88D RADAR AND OBSERVATIONAL TRENDS ARE INDICATING A SLOWING IN
THE SNOW ARRIVING INTO THE TRI-STATE AREA. THE FIRST REPORT OF
SNOW HAS BEEN IN TRINIDAD...COLORADO UNDER THE STRONGER
REFLECTIVITIES ON THE WSR-88D RADAR IN PUEBLO...COLORADO. HAVE
REWORKED THE POP AND WEATHER GRIDS TO REFLECT THIS SLOWING BUT
MAINTAINED THE MENTIONS OF HEAVY TO MODERATE SNOW ONCE THE HEAVY
BAND REACHES THE REGION. MODERATE SNOW WAS REPORTED IN TRINIDAD SO
THINKING FOR HEAVIER SNOW IS STILL ON. ALSO...WINDS HAVE SEEMED TO
COME DOWN A LITTLE IN THE MODEL GUIDANCE FOR TOMORROW. THIS WOULD
REDUCE THE THREAT OF BLOWING AND DRIFTING SNOW. HAVE CONTINUED THE
MENTION OF BLOWING SNOW BUT CONFIDENCE IN WIDESPREAD BLOWING SNOW
PROBLEMS IS LOWER. UNDER THE HEAVIER SNOW BAND...REDUCED
VISIBILITIES ARE STILL LIKELY DUE TO THE HEAVIER SNOWFALL RATES SO
REDUCED VISIBILITIES SHOULD STILL BECOME A PROBLEM. ADJUSTED
TEMPERATURES TO REFLECT THE COOL SPOT OVER NORTHEAST COLORADO
WHERE CLOUDS CLEARED OUT EARLIER. DID NOT ADJUST QPF AND SNOW
AMOUNTS AS THERE IS STILL SOME UNCERTAINTY. HOWEVER...ONE CONCERN
WITH LATEST TRENDS IN MODEL DATA SUGGEST THAT THE HIGHEST AMOUNTS
WILL REMAIN CONFINED TO SOUTHEAST COLORADO WHICH WOULD THUS LOWER
AMOUNTS BELOW WARNING CRITERIA FOR THE WARNED AREA. WILL NEED TO
WATCH THIS CLOSELY.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 121 PM MST MON FEB 3 2014
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOW POSITIVELY TITLED TROUGH
JUST EAST OF THE FOUR CORNERS REGION WITH SW FLOW ADVECTING PLUME OF
MOISTURE AHEAD OF THIS TROUGH FROM THE PACIFIC INTO THE SOUTHERN AND
CENTRAL PLAINS. AT THE SURFACE A FRONT IS CURRENTLY STALLED OVER
NORTHERN NEBRASKA WITH AN ARCTIC FRONT ALONG THE CANADIAN US BORDER.
WINTER STORM ON TRACK TO IMPACT OUR CWA TONIGHT THROUGH TUESDAY WITH
HEAVY SNOW AND BLOWING SNOW. WINTER STORM WARNING WAS ISSUED EARLIER
FOR SW PART OF THE CWA...AND WINTER WEATHER ADVISORY FOR THE REST OF
THE CWA.
TONIGHT-TUESDAY...AS TROUGH OVER WESTERN US ROUNDS THE BASE ON THE
ROCKIES IT WILL BECOME NEGATIVELY TILTED WITH TWO COLD FRONTS
DROPPING SOUTH. THE FIRST WILL PASS THROUGH THE CWA AFTER MIDNIGHT
WITH AN ARCTIC FRONT DROPPING SOUTH THROUGH THE DAY TUESDAY.
INITIALLY SNOW DEVELOPMENT WILL BE TIED TO LOBE OF MID LEVEL
FRONTOGENETICAL FORCING OVER SW COLORADO...WHICH WILL SHIFT NORTH AS
TROUGH MOVES EAST AND THEN NORTH OVER KANSAS. GUIDANCE STILL SHOWS
INSTABILITY IN THE SATURATED LAYER IN SNOW BAND THAT FORMS OVER
COLORADO...WHICH COULD SUPPORT MUCH HIGHER SNOW RATES ACROSS THE SW
PART OF OUR CWA. A CLOSED H7 LOW WILL FORM OVER KANSAS AS THE TROUGH
DEEPENS. THERE CONTINUES TO BE AN INDICATION OF A DEFORMATION BAND
FORMING ALONG THIS 700MB LOW...WITH DIFFERENCES IN ORIENTATION. THIS
DEFORMATION BAND WOULD BE THE MAIN SNOW PRODUCER FOR EASTERN
LOCATIONS...WITH LIGHT SNOW FILLING IN BETWEEN THESE FEATURES. THE
INITIAL BAND OVER COLORADO SHOULD WEAKEN AS BEST UPPER LEVEL SUPPORT
SHIFTS EAST...WITH A WEST-EAST ORIENTATED AREA OF SNOW OVERSPREADING
THE REST OF THE FORECAST AREA. THOUGH MOST GUIDANCE INDICATES A
WEAKENING TREND...WE WILL NEED TO MONITOR TO SEE IF THE INITIAL
CONVECTIVE BAND IN SW COLORADO MAINTAINS ITS INTENSITY AS IT MOVES
NORTH (CURRENTLY INDICATED BY 12Z NAM). IF THIS WERE TO OCCUR WE
WOULD SEE WARNING CRITERIA FURTHER NORTH IN THE CWA. AS IT STANDS
MOST LOCATIONS ALONG THE I-70 CORRIDOR SHOULD SEE 3-5 INCHES WITH
AROUND 3 INCHES IN THE FAR NORTH. CURRENT THOUGHTS ARE LOCATIONS
IMPACTED BY THE CONVECTIVE BAND TONIGHT AND TUESDAY WOULD SEE 6-8
INCHES TOTAL...AND THIS IS WHERE WARNING HAS BEEN ISSUED.
IN ADDITION TO SNOW...BLOWING SNOW SHOULD DEVELOP DURING THE DAY
TUESDAY AS WINDS INCREASE DURING THE DAY. WE MAY NOT SEE THE HIGHEST
WINDS MIX TO THE SURFACE BUT WE SHOULD STILL BE ABLE TO SEE SOME
AFTERNOON GUSTS IN THE 30-35 MPH. THIS SHOULD BE ENOUGH TO PRODUCE
AREAS OF BLOWING SNOW...MAINLY IN THE EAST...THOUGH WE COULD SEE
REDUCED VISIBILITIES JUST ABOUT EVERYWHERE IN THE CWA WITH AT LEAST
PATCHY BLOWING SNOW EXPECTED.
.LONG TERM...(TOMORROW NIGHT THROUGH NEXT MONDAY)
ISSUED AT 1216 PM MST MON FEB 3 2014
LIGHT SNOW WILL BE WINDING DOWN TUESDAY NIGHT...ANY ADDITIONAL
ACCUMULATIONS WILL BE AN INCH OR LESS. WINDS WILL ALSO BE
GRADUALLY DIMINISHING...BUT THERE WILL BE AREAS OF BLOWING SNOW
ESPECIALLY IN THE EVENING. AS THE SNOW ENDS ATTENTION WILL TURN TO
TEMPERATURES. THE PERIOD WEDNESDAY THROUGH FRIDAY WILL BE
BRUTAL...ONE OF THE COLDEST STRETCHES IN RECENT MEMORY. WIND
CHILL WARNINGS OR ADVISORIES WILL LIKELY BE REQUIRED EVERY DAY.
SOME LOW TEMPERATURE RECORDS COULD BE SET...ESPECIALLY THURSDAY
MORNING AS THE SURFACE RIDGE SETTLES OVER THE REGION AND SKIES
CLEAR...TEMPERATURES WILL PLUMMET TO AROUND 15 BELOW. HIGH
TEMPERATURES ON WEDNESDAY AND THURSDAY WILL STRUGGLE TO GET ABOVE
ZERO. SOME ADDITIONAL LIGHT SNOW OR FLURRIES WILL BE POSSIBLE AS A
SERIES OF WEAK DISTURBANCE ROTATE ACROSS THE CENTRAL ROCKIES. THE
MOST SIGNIFICANT SYSTEM FRIDAY NIGHT AND SATURDAY COULD PRODUCE
ANOTHER 2 TO 4 INCHES. FINALLY START TO SEE SOME RIDGING ALOFT
BEHIND THAT SYSTEM AT THE END OF THE PERIOD...POSSIBLY GETTING
ABOVE FREEZING NEXT MONDAY FOR THE FIRST TIME IN QUITE AWHILE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 939 PM MST MON FEB 3 2014
MAIN FOCUS FOR TAFS HAS NOT CHANGED SINCE LAST ISSUANCE. STILL
CONCERNED WITH LOW CEILINGS...VISIBILITY...AND SNOW/BLOWING SNOW.
FOR 06Z TAFS...PUSHED BACK THE TIMING OF THE SNOWFALL SINCE THE
STORM IS MOVING SLOWER THAN PREVIOUSLY THOUGHT. LOOKING UPSTREAM
AT THE WINTER STORM...CURRENT METARS IN SOUTHEAST COLORADO HAVE JUST
REPORTED SNOW OVER THE PAST HOUR. ALSO INCLUDED REDUCED VISIBILITY
AND LOWERED CEILINGS AT KGLD TO BEGIN THE TAF PERIOD AS LOW
CLOUDS AND HAZE MOVE IN FROM THE SOUTHWEST. BLOWING SNOW IS STIL
AN ISSUE FOR KGLD TOMORROW AS NORTHEAST WINDS INCREASE TO AROUND
15 TO 20 KTS WITH GUSTS AROUND 20 TO 25 KTS...RESULTING IN REDUCED
VISIBILITIES AND CEILINGS TO LIFR. KMCK SHOULD STAY SUSTAINED
AROUND 16 KTS...BUT LIFR VISIBILITY AND CEILINGS STILL APPEAR
LIKELY THERE AS WELL. NEW GUIDANCE FROM THE NAM SUGGEST THE EVENT
SHOULD END AROUND 02/03Z TOMORROW...SO HAVE VISIBILITY INCREASING
AND CEILINGS BECOMING MVFR AT THIS TIME. GIVEN HOW THE MODELS HAVE
SLOWED DOWN THE TIMING ON THIS SYSTEM SINCE EARLIER...AMMENDMENTS
WILL BE MADE TO ACCOMODATE CHANGES.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...WINTER WEATHER ADVISORY UNTIL 5 PM MST /6 PM CST/ TUESDAY FOR
KSZ001>004-013>016-028-029.
WINTER STORM WARNING UNTIL 5 PM MST /6 PM CST/ TUESDAY FOR
KSZ027-041-042.
CO...WINTER WEATHER ADVISORY UNTIL 5 PM MST TUESDAY FOR COZ090-091.
WINTER STORM WARNING UNTIL 5 PM MST TUESDAY FOR COZ092.
NE...WINTER WEATHER ADVISORY UNTIL 5 PM MST /6 PM CST/ TUESDAY FOR
NEZ079>081.
&&
$$
UPDATE...RRH
SHORT TERM...DR
LONG TERM...024
AVIATION...ALW
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1213 PM CST Tue Feb 4 2014
.UPDATE...
ISSUED AT 1213 PM CST TUE FEB 4 2014
The 12z data and RAP 2 to 5 degrees too warm at the surface (18z
verification) across west KY. They are OK north and west of the
Ohio. Initial push of precip into west KY with diabatic processes in
play resulting in snow and sleet initially. After that process is
finished, we should transition more toward the overall advertisement
of snow/sleet NW, sleet freezing rain central, rain (wintry mix
possible) SE that we`ve had going.
For now, from Murray over to KHOP, have an SPS out as even there,
travel conditions may be hazardous. Just received a report as the
time of this writing, that roads conditions were not good. An
upgrade to an advisory may be required for this afternoon.
The main focus this afternoon will be on amounts given the
adjustments in QPF rest of today and into this evening.
..Noles..
&&
.SHORT TERM...(Today through Wednesday night)
ISSUED AT 317 AM CST TUE FEB 4 2014
Main forecast concern is the potential for significant snow and
ice accumulations later today into tonight. As a result, a Winter
Storm Warning will be issued shortly to include the entire Quad
State region of southeast Missouri, southern Illinois, southwest
Indiana, and all of western Kentucky with the exception of
Calloway, Trigg, Christian, and Todd counties.
A storm system over the southern Rockies was moving east into the
southern Plains early this morning. This energy will rapidly shift
east into the mid Mississippi valley by tonight. The combination of
a saturating atmosphere with increased forcing for lift will cause
precipitation developing over the central and southern Plains to
move into the forecast area later today. The precipitation will
impact mainly southeast Missouri by late morning, then spread
across the rest of the area during the afternoon. Precipitation
will persist into the early evening before tapering off by late
evening and overnight from west to east.
There are still some subtle differences in forecast models with
respect to the temperature profile. This is normally not a big
issue, but with the presence of the freezing line right through
the Heartland, it is a very big deal today. Forecast models have
continued the cooling trend noted yesterday and are now indicating
that more snow and sleet will occur further south.
Forecast thermal profiles indicate mainly snow with some sleet
along and north of a line from roughly Poplar Bluff to Paducah to
Owensboro. In this area, generally 3 to 5 inches of snow is
forecast during the event.
Mainly rain is still forecast south of a line from Mayfield to
Greenville Kentucky. With the existing snow and ice cover in this
area, the forecast of about 1 inch of rain may result in some
minor flooding issues as normal water flow may be blocked or
diverted due to the ice and snow cover.
In between, a band of freezing rain and sleet appears probable.
This zone would encompass communities from New Madrid to Calvert
City and Madisonville. In this area, up to one quarter inch of ice
accretion is possible. The delineations between precipitation
types may need to be shifted north or south as the winter weather
event evolves.
My greatest concern with the current forecast is the precipitation
type over far southern sections of western Kentucky near the
Tennessee border. Even the coldest model guidance continues to
suggest that temperatures in this area will climb above freezing
by this afternoon, and rain will be the result. However, given the
existing snow and ice cover, if temperatures are not able to make
it above the freezing mark, a substantial icing event cannot be
ruled out. This is likely a last minute adjustment that we will
need to make later today as we get a better handle on exactly how
warm temperatures will be.
The main core of precipitation will exit the area by midnight, but
some light snow or freezing drizzle will be possible through early
Wednesday. For this reason, we have decided to extend the Winter
Storm Warning through 6 AM Wednesday. Light snow showers or
flurries will be possible on Wednesday in the wrap-around moisture
on the back side of the departing storm. Expect a trend towards
clearing Wednesday night with a return to those frigid temperatures
that we`ve come to adore this winter...or not.
.LONG TERM...(Thursday through Monday)
ISSUED AT 317 AM CST TUE FEB 4 2014
No rest for the weary in the long term portion of the forecast.
Unfortunately models not in good agreement on the timing, track,
QPF, etc. associated with the multiple weather features forecast to
affect our CWA during the period.
Thursday should be dry and cold as arctic high pressure builds
across the region. Thursday night models show high pressure centered
directly over the region but bring an almost indiscernible upper
level disturbance across the area with limited moisture. With the
exception of the NAM12 and the ECMWF, the rest of the models keep it
dry, but just in case there are a few flurries will keep schc pops
over the western and northwest sections.
With no upper level support and the arctic high pressure still the
dominant weather feature over the Ohio valley, Friday should be dry
and cold. Better chances for precipitation enter the forecast Friday
night as an approaching short wave interacts with decent moisture to
produce light snow across the area. The Canadian/ECMWF are similar
with this feature but the GFS keeps it dry. If it does snow,
accumulations should be light.
Depending on what model you look at, snow may linger into Saturday,
or not. With there being so much model disagreement decided to just
go with a schc pop. Precipitation type should be all snow with the
exception of the southern Pennyrile region of west Kentucky where
there could be a rain/snow mix. Any snow accumulation should be
light.
Right now the highest pops during the period are Saturday night.
During this period the GFS and Canadian are dry with upper level
moisture and precipitation to the north and west of our CWA. The
ECMWF brings a sharp short wave with one to two tenths of an inch of
QPF across the region which would be in the form of snow with small
accumulations possible. Just in case the ECMWF is too fast, lowered
pops a tad but kept chc pops everywhere.
Ironically enough, the GFS and Canadian bring that same short wave
and moisture across our area on Sunday, so just in case their
solutions pan out, went with schc pops which should again be all
snow with little to no accumulation.
Beyond that arctic high pressure should keep the region dry and
cold. Temperatures throughout the period will remain well below
normal.
&&
.AVIATION...
ISSUED AT 541 AM CST TUE FEB 4 2014
All sites should remain VFR through 18z, with conditions slowly
deteriorating from west to east to MVFR with a mixture of
FZRA/PL/SN, and eventually IFR with a continued mixture of
FZRA/PL/SN. Winds will continue out of the northeast aob 10 knots
through 06-07Z, then switching around to the northwest aob 10 knots.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...WINTER STORM WARNING until 6 AM CST Wednesday FOR ILZ075>078-
080>094.
MO...WINTER STORM WARNING until 6 AM CST Wednesday FOR MOZ076-086-087-
100-107>112-114.
IN...WINTER STORM WARNING until 6 AM CST Wednesday FOR INZ081-082-
085>088.
KY...WINTER STORM WARNING until 6 AM CST Wednesday FOR KYZ001>008-010-
011-013>016-018>021.
&&
$$
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1056 AM CST Tue Feb 4 2014
.UPDATE...
ISSUED AT 1055 AM CST TUE FEB 4 2014
One of the most difficult forecasts had to deal with in some time.
Latest NAM and RAP data suggesting warmer air into west KY by this
afternoon with a transition to rain...and more of a wintry mix
north and west of the Ohio vs. snow. GFS, while slightly "warmer"
is still the coolest solution (all 12z data). We are seeing mainly
snow over the Ozark foothill region at this time with some sleet.
Sleet was reported along the KY/TN state line into the Murray
area. Initially, diabatic processes will help determine precip
type. Should be mainly a wintry mix / snow.
We are not going to change the Winter Storm Warning at this time.
The southern counties in the Warning are in question if the warmer
solutions pan out. For now, we are shifting the precip type and
amounts more toward what we were looking at yesterday. Once the
precip starts and establishes a baseline for temperatures, we can
watch the trajectories and advection processes near the surface.
Am concerned amount decent icing somewhere of 1/4" or more and
sleet 1/2" or more. Cannot rule out the 4 inch or so (isolated higher)
snow amounts across the NW 1/3 of the area, with some sleet
accumulation possible as well. Mainly rain by afternoon and early
evening near the TN state line (may have to adjust that NW if the
warmer models are correct). The latest model QPF has shifted the
heavy axis farther west. If need be, we will up the wintry precip
amounts. The WSW has been transmitted. The grids have been
updated. Will continue to monitor.
..Noles..
&&
.SHORT TERM...(Today through Wednesday night)
ISSUED AT 317 AM CST TUE FEB 4 2014
Main forecast concern is the potential for significant snow and
ice accumulations later today into tonight. As a result, a Winter
Storm Warning will be issued shortly to include the entire Quad
State region of southeast Missouri, southern Illinois, southwest
Indiana, and all of western Kentucky with the exception of
Calloway, Trigg, Christian, and Todd counties.
A storm system over the southern Rockies was moving east into the
southern Plains early this morning. This energy will rapidly shift
east into the mid Mississippi valley by tonight. The combination of
a saturating atmosphere with increased forcing for lift will cause
precipitation developing over the central and southern Plains to
move into the forecast area later today. The precipitation will
impact mainly southeast Missouri by late morning, then spread
across the rest of the area during the afternoon. Precipitation
will persist into the early evening before tapering off by late
evening and overnight from west to east.
There are still some subtle differences in forecast models with
respect to the temperature profile. This is normally not a big
issue, but with the presence of the freezing line right through
the Heartland, it is a very big deal today. Forecast models have
continued the cooling trend noted yesterday and are now indicating
that more snow and sleet will occur further south.
Forecast thermal profiles indicate mainly snow with some sleet
along and north of a line from roughly Poplar Bluff to Paducah to
Owensboro. In this area, generally 3 to 5 inches of snow is
forecast during the event.
Mainly rain is still forecast south of a line from Mayfield to
Greenville Kentucky. With the existing snow and ice cover in this
area, the forecast of about 1 inch of rain may result in some
minor flooding issues as normal water flow may be blocked or
diverted due to the ice and snow cover.
In between, a band of freezing rain and sleet appears probable.
This zone would encompass communities from New Madrid to Calvert
City and Madisonville. In this area, up to one quarter inch of ice
accretion is possible. The delineations between precipitation
types may need to be shifted north or south as the winter weather
event evolves.
My greatest concern with the current forecast is the precipitation
type over far southern sections of western Kentucky near the
Tennessee border. Even the coldest model guidance continues to
suggest that temperatures in this area will climb above freezing
by this afternoon, and rain will be the result. However, given the
existing snow and ice cover, if temperatures are not able to make
it above the freezing mark, a substantial icing event cannot be
ruled out. This is likely a last minute adjustment that we will
need to make later today as we get a better handle on exactly how
warm temperatures will be.
The main core of precipitation will exit the area by midnight, but
some light snow or freezing drizzle will be possible through early
Wednesday. For this reason, we have decided to extend the Winter
Storm Warning through 6 AM Wednesday. Light snow showers or
flurries will be possible on Wednesday in the wrap-around moisture
on the back side of the departing storm. Expect a trend towards
clearing Wednesday night with a return to those frigid temperatures
that we`ve come to adore this winter...or not.
.LONG TERM...(Thursday through Monday)
ISSUED AT 317 AM CST TUE FEB 4 2014
No rest for the weary in the long term portion of the forecast.
Unfortunately models not in good agreement on the timing, track,
QPF, etc. associated with the multiple weather features forecast to
affect our CWA during the period.
Thursday should be dry and cold as arctic high pressure builds
across the region. Thursday night models show high pressure centered
directly over the region but bring an almost indiscernible upper
level disturbance across the area with limited moisture. With the
exception of the NAM12 and the ECMWF, the rest of the models keep it
dry, but just in case there are a few flurries will keep schc pops
over the western and northwest sections.
With no upper level support and the arctic high pressure still the
dominant weather feature over the Ohio valley, Friday should be dry
and cold. Better chances for precipitation enter the forecast Friday
night as an approaching short wave interacts with decent moisture to
produce light snow across the area. The Canadian/ECMWF are similar
with this feature but the GFS keeps it dry. If it does snow,
accumulations should be light.
Depending on what model you look at, snow may linger into Saturday,
or not. With there being so much model disagreement decided to just
go with a schc pop. Precipitation type should be all snow with the
exception of the southern Pennyrile region of west Kentucky where
there could be a rain/snow mix. Any snow accumulation should be
light.
Right now the highest pops during the period are Saturday night.
During this period the GFS and Canadian are dry with upper level
moisture and precipitation to the north and west of our CWA. The
ECMWF brings a sharp short wave with one to two tenths of an inch of
QPF across the region which would be in the form of snow with small
accumulations possible. Just in case the ECMWF is too fast, lowered
pops a tad but kept chc pops everywhere.
Ironically enough, the GFS and Canadian bring that same short wave
and moisture across our area on Sunday, so just in case their
solutions pan out, went with schc pops which should again be all
snow with little to no accumulation.
Beyond that arctic high pressure should keep the region dry and
cold. Temperatures throughout the period will remain well below
normal.
&&
.AVIATION...
ISSUED AT 541 AM CST TUE FEB 4 2014
All sites should remain VFR through 18z, with conditions slowly
deteriorating from west to east to MVFR with a mixture of
FZRA/PL/SN, and eventually IFR with a continued mixture of
FZRA/PL/SN. Winds will continue out of the northeast aob 10 knots
through 06-07Z, then switching around to the northwest aob 10 knots.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...WINTER STORM WARNING until 6 AM CST Wednesday FOR ILZ075>078-
080>094.
MO...WINTER STORM WARNING until 6 AM CST Wednesday FOR MOZ076-086-087-
100-107>112-114.
IN...WINTER STORM WARNING until 6 AM CST Wednesday FOR INZ081-082-
085>088.
KY...WINTER STORM WARNING until 6 AM CST Wednesday FOR KYZ001>008-010-
011-013>016-018>021.
&&
$$
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
417 PM EST TUE FEB 4 2014
.SYNOPSIS...
LOW PRESSURE WILL TRACK WEST OF THE APPALACHIANS LATE TONIGHT...PUSHING
A TRAILING COLD FRONT ACROSS THE REGION WEDNESDAY. HIGH PRESSURE
BUILDS IN FROM THE WEST WEDNESDAY NIGHT AND THURSDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
LATEST WX ANALYSIS SHOWS ~1034 MB SFC HIGH PRESSURE IN PLACE OVER
THE EASTERN GREAT LAKES THIS AFTERNOON, WITH WEAK CAD RIDGING DOWN
INTO THE MID-ATLANTIC REGION. ALOFT, WV SAT IMAGERY SHOWING
SHORTWAVE ENERGY NOW LIFTING NORTH-NORTHEAST ACROSS THE MID-SOUTH
THIS AFTERNOON...HEADED TOWARDS IN/IL THROUGH THIS EVENING. LATEST
REGIONAL RADAR MOSAIC SHOWING SOME VERY LIGHT RETURNS TO OUR SOUTH
ACROSS THE CAROLINAS...AND EXPECT THIS ACTIVITY TO CONTINUE TO LIFT
TOWARDS THE CWA THROUGH EARLY THIS EVENING. LATEST RAP HAS CAPTURED
TRENDS OVER THE PAST FEW HOURS WELL...AND FORECAST FOR THE EVENING
WILL HAVE A SIMILAR FLAVOR AS BEST LIFT (290-300K ISENTROPIC SFC)
SLIPS NORTH. GENERALLY, SHRAS WILL PUSH ACROSS SOUTH CENTRAL
VA/INTERIOR NE NC THROUGH 23Z OR SO, WITH BEST SLUG OF MOISTURE HEADED
TOWARDS RIC/EZF AS THE EVENING WEARS ON. INITIALLY, BEST MOISTURE IS
IN THE SUB-CLOUD LYR, WITH DRIER AIR REMAINING ALOFT. THUS, EXPECT
RAIN TO BE LITTLE MORE THAN SOME SPOTTY DZ EARLY ON...BECOMING MORE
STEADY AS LIFT IMPROVES LATER ON IN THE EVENING. PCPN ENDS FROM
SOUTHWEST TO NORTHEAST ACROSS THE PIEDMONT DURING THE LATE
EVENING/OVERNIGHT, THOUGH EXPECT PATCHY DZ TO PERSIST THROUGH THE
NIGHT AS LLVLS REMAIN MOIST. ALSO EXPECT AREAS OF FOG DEVELOPING
LATE TONIGHT OVER SOUTH CENTRAL/SE VA INTO NE NC AS LOW PRESSURE
LIFTS INTO THE WESTERN OH VLY AND WARM FRONT LIFTS TOWARDS THE
LOCAL AREA...RESULTING IN WARMING TEMPS AFTER MIDNIGHT ACROSS THE
SOUTHEAST. EXPECT BEST LIFT TO CLEAR THE AREA BEFORE TEMPERATURES
IN THE NW FLIRT WITH ANY FZRA POTENTIAL (WHICH WILL LIE JUST NW OF
OUR CWA BORDERS). MINIMA WILL LIKELY BE ACHIEVED EARLY ACROSS THE
SOUTHEAST BEFORE BECOMING STEADY THEN SLOWLY RISING OVERNIGHT.
ACROSS THE NORTH, EXPECT TEMPERATURES TO FALL INTO THE MID TO
UPPER 30S BY LATE EVENING.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
LOW PRESSURE WILL CONTINUE TO LIFT NEWD OVER THE NRN MID-ATLANTIC
ON WEDNESDAY, EVENTUALLY SHUNTING THE ASSOCIATED SFC COLD FRONT
ACROSS THE REGION BY LATE MORNING-EARLY AFTERNOON. WHILE A
130-150KT JET STREAK WILL KEEP BEST SHORTWAVE ENERGY CONFINED TO
THE NORTH OF THE LOCAL AREA, EXPECT ENOUGH UVM/FGEN FORCING ALONG
THE COLD FRONT TO PRODUCE LIKELY SHOWERS COINCIDING WITH THE
FROPA. AS WARM FRONT LIFTS NORTH AHEAD OF THE COLD FRONT, RETURN
FLOW WILL ALLOW TEMPS TO WARM INTO THE 60S AS DEWPOINTS CLIMB INTO
THE 50S. SREF PROBS SHOWING 50-60% CHC OF MLCAPE VALUES REACHING
500 J/KG...SO EXPECT EXPECT LITTLE MORE THAN A MARGINALLY UNSTABLE
AIRMASS ACROSS FAR SE ZONES. COMBINED WITH PLENTY OF CLOUDS AND
RATHER WEAK LAPSE RATES...CONVECTIVE ACTIVITY IS NOT EXPECTED
(THOUGH A RUMBLE OR TWO OF THUNDER CAN`T BE RULED OUT).
REGARDLESS, CONVECTIVE ELEMENTS WITHIN THE MAIN LINE COULD BRING
SOME HEAVIER SHOWERS WED AFTN.
CLEARING SHOULD ENSUE QUICKLY W-E BY AFTERNOON...AS DOWNSLOPE WNW
FLOW DEVELOPS BEHIND THE FRONT AND SCOURS OUT MUCH OF THE MORNING
CLOUDINESS. HIGHS SHOULD RANGE FROM THE UPPER 40S OVER THE EASTERN
SHORE...LOW 50S NW...TO MID TO UPPER 60S IN THE WARM SECTOR
ACROSS THE SE. STORM TOTAL QPF WILL BE HIGHEST IN THE NORTH (UP TO
ONE HALF INCH) AND ALONG THE COAST (BETWEEN A QUARTER AND HALF INCH).
LESSER AMOUNTS EXPECTED FROM THE PIEDMONT INTO CENTRAL VA WITH
AMOUNTS GENERALLY UNDER ONE QUARTER OF AN INCH.
STRONG 1042+MB HIGH PRESSURE SPILLS ACROSS THE PLAINS WED NIGHT
THROUGH FRIDAY, SHUNTING THE AFOREMENTIONED COLD FRONT FARTHER
OFFSHORE AS QUASI-ZONAL FLOW ALOFT ENSUES FOR THE LATTER HALF OF
THE WORK WEEK. DRY WX IS EXPECTED THU/FRI AS SFC HI PRES BRIEFLY
SLIDES TOWARDS THE MID ATLANTIC. HIGHS FORECAST TO RANGE FROM THE
UPR 30S OVER THE LWR MD ERN SHORE TO THE LOW/MID 40S ELSEWHERE.
EARLY MORNING LOWS IN THE 30S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
DRY CONDITIONS TO START OFF THE PERIOD WITH STRONG SFC HIGH PRES
CENTERED OVR THE OH VALLEY EXTENDING INTO THE MID ATLANTIC AND
ZONAL FLOW ALOFT. THIS PATTERN WILL BREAK DOWN STARTING SATURDAY
WITH THE FOCUS IN THE LONG TERM ON A PROGRESSIVE MID-LEVEL
SHORTWAVE TROF TRAVERSING THE CONUS. MODELS DIFFER WITH THE
PLACEMENT AND TRACK OF THE SURFACE LOW WHICH DEVELOPS ALONG THE
COAST SATURDAY. THE ECMWF PUSHES QPF WEST INTO SE VA AND EVEN
CENTRAL VA SATURDAY. A BLEND OF THE TWO PUSHES CHANCE POPS INTO
CENTRAL VA SAT AFTERNOON. HAVE POPS RANGING FROM 50% ACROSS NE NC
AND SE VA TO 35% ACROSS THE PIEDMONT AND MD SATURDAY AFTERNOON.
HIGH TEMPS SAT DEPEND HIGHLY ON CLOUD COVER AND AMOUNT OF
SCATTERED SHOWERS. HAVE TENDED ON THE COOL SIDE....BUT SHOULD
THERE BE A FEW BREAKS IN THE CLOUDS TEMPS WILL NEED TO BE RAISED.
ONCE THIS FIRST COASTAL LOW RAPIDLY EXISTS CONDITIONS...ESPECIALLY
INLAND...WILL BE DRY FOR A PERIOD UNTIL THE NEXT SYSTEM ARRIVES
SUNDAY. A STRONGER WAVE DEVELOPS SUNDAY. MODELS DIFFER HIGHLY ON
THIS SCENARIO WITH THE ECMWF RUNNING FASTER AND COLDER. A BLEND OF
THE MODELS MODELS INTRODUCES A RAIN SNOW MIX SUNDAY ACROSS THE
PIEDMONT AND MD SUNDAY. SURFACE TEMPS WILL LIKELY BE TOO WARM FOR
ANY REAL ACCUMULATION IN AREAS WHERE THE RAIN/SNOW MIX OCCURS.
EXPECT ALL RAIN SUNDAY ACROSS SE VA AND NE NC. AS THE SYSTEM PULLS
AWAY FROM THE COAST SUNDAY EVENING A BRIEF PERIOD OF SNOW (MIXED
WITH SOME RAIN) COULD SPREAD EAST TO THE COAST...BUT THIS SHOULD BE
BRIEF AS DRY AIR MOVES IN RAPIDLY.
BEHIND THIS STORM SYSTEM ANOTHER STRONG SURGE OF COLD AIR IS
EXPECTED WITH BELOW NORMAL TEMPS EXPECTED EARLY NEXT WEEK.
&&
.AVIATION /21Z TUESDAY THROUGH SUNDAY/...
A SOLID LOW STRATUS DECK OF 600-2000 FT AGL WILL GRADUALLY PUSH
FARTHER INLAND FROM THE COAST TODAY WHILE CTRL VA STAYS RELATIVELY
CLOUD-FREE. THIS ALL ENDS AFTER 05/0000Z TONIGHT AS LOW CIGS
(ASSOCIATED WITH A WARM FRONT) LIFT NORTH FROM THE SE STATES TWD
THE MID ATLANTIC REGION OVERNIGHT. RAIN/DRIZZLE WILL ALSO MOVE
INTO THE AREA FROM THE SOUTHWEST AFTER THIS TIME AND OVERSPREAD
THE REGION BY 05/0600Z. THE ADDITIONAL MOISTURE FROM THE PRECIP
AND WARM FRONT WILL LOWER CIGS TO LIFR CONDITIONS AND WILL ALSO
LOWER VISIBILITIES TO ROUGHLY 2SM...POSSIBLY DOWN TO 1SM DURING
PERIODS OF HEAVIER RAINFALL. A LOW PRESSURE SYSTEM PASSES NW OF
THE REGION ON WED...PUSHING A COLD FRONT THROUGH THE AREA WED
AFTN. PRECIPITATION SHOULD END FROM WEST TO EAST DURING THE AFTN
WITH SHOWERS EXITING THE COAST BY EARLY WED EVENING. SOLID
OVERCAST SKIES BEGIN TO BREAK UP BEHIND THE FROPA AND VFR
CONDITIONS WILL RETURN WED NIGHT/THU. POST-FRONTAL WINDS ARE
EXPECTED TO BECOME GUSTY FROM THE NNW.
&&
.MARINE...
SCA CONTINUES THIS EVENING JUST FOR THE NC WATERS WHERE SEAS HAVE
BEEN SLOW TO FALL BELOW 5 TO 6 FT WITH THE NLY WINDS. SEAS WILL
DECREASE TO 5 FT OR LESS LATER THIS EVENING. ELSEWHERE WAVES AND
SEAS HAVE BEEN SLOWLY DECREASING ACROSS THE BAY AND COASTAL WATERS
AS THE PRES GRAD RELAXED SLIGHTLY. A SURFACE LOW WILL DEVELOP ALONG
THE COAST OVERNIGHT THEN LIST NE TO THE DELMARVA BY WED MORNING.
THIS WILL RESULT IN AN INCREASING SLY FLOW WED MORNING. WINDS AND
SEAS LOOK TO REMAIN SUB SCA FOR THE NEAR SHORE WATERS AND BAY AT
THIS TIME. WINDS COULD BRIEFLY REACH SCA CRITERIA SOME TIME WED
MORNING INTO EARLY AFTERNOON...HOVER...SLY WIND EVENTS TEND TO BE
OVER PREDICTED IN THE MODELS THIS TIME OF YEAR DUE TO THE COLD
WATERS. WILL WATCH THE TRENDS OVERNIGHT IN CASE A SCA IS NEEDED FOR
WED.
AS THE SURFACE LOW DEPARTS WED NIGHT A COLD FRONT WILL PUSH SOUTH
ACROSS ALL WATERS WED NIGHT INTO EARLY THU MORNING. THE BEST NLY
SURGE WITH THIS FRONT WILL OCCUR FROM 06Z-16Z THURSDAY. SCA COND ARE
LIKELY ALONG THE BAY AND COASTAL WATERS WITH THIS NLY SURGE.
HIGH PRES SETTLES IN OVER THE REGION LATE THUR THROUGH FRIDAY
MORNING BRINGING CALMER WINDS AND SUBSIDING SEAS.
THE PATTEN BECOMES UNSETTLED AGAIN OVER THE WEEKEND AS AREAS OF LOW
PRESSURE DEVELOP ALONG THE COAST AND INLAND STARTING LATE SATURDAY.
THIS PERIOD OF INCREASED WIND AND SEAS WILL LIKELY LAST THROUGH
SUNDAY AND INTO MONDAY WITH SCA COND LIKELY.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR ANZ658.
&&
$$
SYNOPSIS...MAM
NEAR TERM...MAM
SHORT TERM...MAM/SAM
LONG TERM...JAO
AVIATION...ALB/BMD
MARINE...BMD/JAO
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
359 PM EST TUE FEB 4 2014
.SYNOPSIS...
LOW PRESSURE WILL TRACK WEST OF THE APPALACHIANS LATE TONIGHT...PUSHING
A TRAILING COLD FRONT ACROSS THE REGION WEDNESDAY. HIGH PRESSURE
BUILDS IN FROM THE WEST WEDNESDAY NIGHT AND THURSDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
LATEST WX ANALYSIS SHOWS ~1034 MB SFC HIGH PRESSURE IN PLACE OVER
THE EASTERN GREAT LAKES THIS AFTERNOON, WITH WEAK CAD RIDGING DOWN
INTO THE MID-ATLANTIC REGION. ALOFT, WV SAT IMAGERY SHOWING
SHORTWAVE ENERGY NOW LIFTING NORTH-NORTHEAST ACROSS THE MID-SOUTH
THIS AFTERNOON...HEADED TOWARDS IN/IL THROUGH THIS EVENING. LATEST
REGIONAL RADAR MOSAIC SHOWING SOME VERY LIGHT RETURNS TO OUR SOUTH
ACROSS THE CAROLINAS...AND EXPECT THIS ACTIVITY TO CONTINUE TO LIFT
TOWARDS THE CWA THROUGH EARLY THIS EVENING. LATEST RAP HAS CAPTURED
TRENDS OVER THE PAST FEW HOURS WELL...AND FORECAST FOR THE EVENING
WILL HAVE A SIMILAR FLAVOR AS BEST LIFT (290-300K ISENTROPIC SFC)
SLIPS NORTH. GENERALLY, SHRAS WILL PUSH ACROSS SOUTH CENTRAL
VA/INTERIOR NE NC THROUGH 23Z OR SO, WITH BEST SLUG OF MOISTURE HEADED
TOWARDS RIC/EZF AS THE EVENING WEARS ON. INITIALLY, BEST MOISTURE IS
IN THE SUB-CLOUD LYR, WITH DRIER AIR REMAINING ALOFT. THUS, EXPECT
RAIN TO BE LITTLE MORE THAN SOME SPOTTY DZ EARLY ON...BECOMING MORE
STEADY AS LIFT IMPROVES LATER ON IN THE EVENING. PCPN ENDS FROM
SOUTHWEST TO NORTHEAST ACROSS THE PIEDMONT DURING THE LATE
EVENING/OVERNIGHT, THOUGH EXPECT PATCHY DZ TO PERSIST THROUGH THE
NIGHT AS LLVLS REMAIN MOIST. ALSO EXPECT AREAS OF FOG DEVELOPING
LATE TONIGHT OVER SOUTH CENTRAL/SE VA INTO NE NC AS LOW PRESSURE
LIFTS INTO THE WESTERN OH VLY AND WARM FRONT LIFTS TOWARDS THE
LOCAL AREA...RESULTING IN WARMING TEMPS AFTER MIDNIGHT ACROSS THE
SOUTHEAST. EXPECT BEST LIFT TO CLEAR THE AREA BEFORE TEMPERATURES
IN THE NW FLIRT WITH ANY FZRA POTENTIAL (WHICH WILL LIE JUST NW OF
OUR CWA BORDERS). MINIMA WILL LIKELY BE ACHIEVED EARLY ACROSS THE
SOUTHEAST BEFORE BECOMING STEADY THEN SLOWLY RISING OVERNIGHT.
ACROSS THE NORTH, EXPECT TEMPERATURES TO FALL INTO THE MID TO
UPPER 30S BY LATE EVENING.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
LOW PRESSURE WILL CONTINUE TO LIFT NEWD OVER THE NRN MID-ATLANTIC
ON WEDNESDAY, EVENTUALLY SHUNTING THE ASSOCIATED SFC COLD FRONT
ACROSS THE REGION BY LATE MORNING-EARLY AFTERNOON. WHILE A
130-150KT JET STREAK WILL KEEP BEST SHORTWAVE ENERGY CONFINED TO
THE NORTH OF THE LOCAL AREA, EXPECT ENOUGH UVM/FGEN FORCING ALONG
THE COLD FRONT TO PRODUCE LIKELY SHOWERS COINCIDING WITH THE
FROPA. AS WARM FRONT LIFTS NORTH AHEAD OF THE COLD FRONT, RETURN
FLOW WILL ALLOW TEMPS TO WARM INTO THE 60S AS DEWPOINTS CLIMB INTO
THE 50S. SREF PROBS SHOWING 50-60% CHC OF MLCAPE VALUES REACHING
500 J/KG...SO EXPECT EXPECT LITTLE MORE THAN A MARGINALLY UNSTABLE
AIRMASS ACROSS FAR SE ZONES. COMBINED WITH PLENTY OF CLOUDS AND
RATHER WEAK LAPSE RATES...CONVECTIVE ACTIVITY IS NOT EXPECTED
(THOUGH A RUMBLE OR TWO OF THUNDER CAN`T BE RULED OUT).
REGARDLESS, CONVECTIVE ELEMENTS WITHIN THE MAIN LINE COULD BRING
SOME HEAVIER SHOWERS WED AFTN.
CLEARING SHOULD ENSUE QUICKLY W-E BY AFTERNOON...AS DOWNSLOPE WNW
FLOW DEVELOPS BEHIND THE FRONT AND SCOURS OUT MUCH OF THE MORNING
CLOUDINESS. HIGHS SHOULD RANGE FROM THE UPPER 40S OVER THE EASTERN
SHORE...LOW 50S NW...TO MID TO UPPER 60S IN THE WARM SECTOR
ACROSS THE SE. STORM TOTAL QPF WILL BE HIGHEST IN THE NORTH (UP TO
ONE HALF INCH) AND ALONG THE COAST (BETWEEN A QUARTER AND HALF INCH).
LESSER AMOUNTS EXPECTED FROM THE PIEDMONT INTO CENTRAL VA WITH
AMOUNTS GENERALLY UNDER ONE QUARTER OF AN INCH.
STRONG 1042+MB HIGH PRESSURE SPILLS ACROSS THE PLAINS WED NIGHT
THROUGH FRIDAY, SHUNTING THE AFOREMENTIONED COLD FRONT FARTHER
OFFSHORE AS QUASI-ZONAL FLOW ALOFT ENSUES FOR THE LATTER HALF OF
THE WORK WEEK. DRY WX IS EXPECTED THU/FRI AS SFC HI PRES BRIEFLY
SLIDES TOWARDS THE MID ATLANTIC. HIGHS FORECAST TO RANGE FROM THE
UPR 30S OVER THE LWR MD ERN SHORE TO THE LOW/MID 40S ELSEWHERE.
EARLY MORNING LOWS IN THE 30S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
DRY CONDITIONS TO START OFF THE PERIOD WITH STRONG SFC HI PRES
CENTERED OVR THE OH VALLEY AND ZONAL FLOW ALOFT. FOCUS IN THE LONG
TERM PERIOD WILL BE ON A PROGRESSIVE MID-LEVEL SHORTWAVE TROF
TRAVERSING THE CONUS AND ASSOCIATED SFC LO PRES DEVELOPMENT OVR THE
ERN CONUS DURING THE WEEKEND. DID DELAY THE ONSET OF PRECIP WITH
THIS FORECAST PACKAGE...WITH PRECIP EXPECTED TO OVERSPREAD FROM SOUTH
TO NORTH ACROSS THE AREA FRI NGT THRU SAT. MODELS CONTINUE TO
SUGGEST THIS WILL MSTLY BE A PLAIN RAIN EVENT...WITH SFC TEMPS AND
TEMPS ALOFT SUGGESTING SOME FREEZING RAIN/SLEET/SNOW MAY BE PSBL
ESPECIALLY NORTH/WEST OF RIC AT THE VERY ONSET OF THE PRECIP...AND
AT THE END AS THICKNESSES CRASH. MAIN IMPACT WILL BE HEAVY
RAIN...WITH AT LEAST 1-2 INCHES PSBL FRI NGT THRU SUN NGT. TEMPS FRI
THRU SUN WILL BE NEAR NORMAL...WITH HIGHS AVGG IN THE MID 40S TO LWR
50S.
&&
.AVIATION /21Z TUESDAY THROUGH SUNDAY/...
A SOLID LOW STRATUS DECK OF 600-2000 FT AGL WILL GRADUALLY PUSH
FARTHER INLAND FROM THE COAST TODAY WHILE CTRL VA STAYS RELATIVELY
CLOUD-FREE. THIS ALL ENDS AFTER 05/0000Z TONIGHT AS LOW CIGS
(ASSOCIATED WITH A WARM FRONT) LIFT NORTH FROM THE SE STATES TWD
THE MID ATLANTIC REGION OVERNIGHT. RAIN/DRIZZLE WILL ALSO MOVE
INTO THE AREA FROM THE SOUTHWEST AFTER THIS TIME AND OVERSPREAD
THE REGION BY 05/0600Z. THE ADDITIONAL MOISTURE FROM THE PRECIP
AND WARM FRONT WILL LOWER CIGS TO LIFR CONDITIONS AND WILL ALSO
LOWER VISIBILITIES TO ROUGHLY 2SM...POSSIBLY DOWN TO 1SM DURING
PERIODS OF HEAVIER RAINFALL. A LOW PRESSURE SYSTEM PASSES NW OF
THE REGION ON WED...PUSHING A COLD FRONT THROUGH THE AREA WED
AFTN. PRECIPITATION SHOULD END FROM WEST TO EAST DURING THE AFTN
WITH SHOWERS EXITING THE COAST BY EARLY WED EVENING. SOLID
OVERCAST SKIES BEGIN TO BREAK UP BEHIND THE FROPA AND VFR
CONDITIONS WILL RETURN WED NIGHT/THU. POST-FRONTAL WINDS ARE
EXPECTED TO BECOME GUSTY FROM THE NNW.
&&
.MARINE...
UPDATE...PERSISTENT N-NE WINDS ALONG THE ATLANTIC COAST FROM CAPE
HENRY TO CURRITUCK LIGHT HAS WARRANTED AN EXTENSION TO ONGOING SCA
DUE TO SEAS OF 5-7 FT BEING SLOW TO SUBSIDE THIS AFTN. SCA FOR SRN
COASTAL WATERS IS NOW SET TO EXPIRE AT 4 PM EST TODAY.
PREVIOUS DISCUSSION...SCAS WILL RMN SLO TO COME DOWN THROUGH THE
MRNG HRS AS NNE WNDS SLO TO DIMINISH. SEAS ON THE OCN WILL TAKE
LONGEST TO SUBSIDE (TO BLO SCA - 5FT)...ESP S OF CAPE CHARLES LGT.
A WARM FRONT TO LIFT N OF THE WTRS TNGT...RESULTING IN WINDS
BECOMING S. SFC LO PRES MOVES THROUGH THE NRN PORTION OF THE
MDATLC STATES WED MRNG...THEN CONTS TO THE E WED AFTN...PUSHING A
CDFNT ACRS THE WTRS BY WED EVE. ANOTHER OF SCAS XPCD
TNGT/WED...ESP OVR THE OCN...AS SPEEDS INCRS FM THE SSW (AND SEAS
BUILD TO 5FT)...BUT WILL HOLD OFF ON ANY ADDITIONAL HEADLINE W/
THE ONE ONGOING ATTM. WINDS SHIFT TO NW WED NGT W/ LO LVL CAD
PTNTTLY STRONG ENOUGH FOR SCA CONDS. SFC HI PRES THEN RETURNS THU
THROUGH FRI.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR ANZ658.
&&
$$
SYNOPSIS...MAM
NEAR TERM...MAM
SHORT TERM...MAM/SAM
LONG TERM...MAS
AVIATION...ALB/BMD
MARINE...ALB/BMD
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1240 PM EST TUE FEB 4 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 501 AM EST TUE FEB 4 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A TROUGH FROM HUDSON BAY INTO
MANITOBA AND SRN SASK AND A RIDGE OVER THE SE CONUS RESULTING IN WSW
MID/UPPER LEVEL NRN STREAM FLOW THROUGH THE WRN GREAT LAKES. AT THE
SFC...WEAK NW TO N FLOW HAD DEVELOPED OVER LAKE SUPERIOR BEHIND A
COLD FRONT EXTENDING FROM JAMES BAY INTO ERN UPPER MI AND CNTRL WI.
TO THE WEST...A RIDGE EXTENDED FROM WRN CANADA INTO THE NRN PLAINS.
THERE WAS ENOUGH TO MOISTURE BELOW THE 4K FT INVERSION FOR CLOUDS
ACROSS MUCH OF NRN ONTARIO LAKE SUPERIOR AND NRN UPPER MI. WITH 850
MB TEMPS TO AROUND -18C...RADAR INDICATED SOME LIGHT LES FROM
MARQUETTE TO MUNISING WHERE GAPS IN THE ICE COVER WERE PRESENT.
TODAY...SINCE A WEAK PRES GRADIENT AND LIGHT WINDS ARE EXPECTED
ACROSS LAKE SUPERIOR...ANY ADDITIONAL LES IS EXPECTED WILL BE
DISORGANIZED AND DIFFICULT TO PREDICT GIVEN THE EXTENSIVE ICE COVER.
THE BEST CHANCE FOR SOME LIGHT ACCUMULATIONS WILL BE INTO THE NE
CWA...CLOSER TO THE LARGER REMAINING AREA OF OPEN WATER. SOME
FLURRIES ARE ALSO EXPECTED TO PERSIST BETWEEN MARQUETTE AND MUNISING
DOWNWIND OF ANOTHER LIMITED STRETCH OF OPEN WATER.
OTHERWISE...PARTLY TO MOSTLY CLOUDY SKIES ARE EXPECTED ACROSS THE
NORTH WITH THE MOST SUNSHINE CLOSER TO THE WI BORDER. TEMPERATURES
WILL REMAIN BELOW NORMAL WITH HIGHS IN THE TEENS.
TONIGHT...THE GRADIENT WILL TIGHTEN AND ACYC NRLY FLOW WILL INCREASE
AS HIGH PRES BUILDS INTO THE NRN ONTARIO AND A LOW MOVES THROUGH THE
OH VALLEY. EVEN WITH LIMITED HEAT/MOISTURE FLUX ACROSS THE MOSTLY
ICE COVERED LAKE...SOME LAKE CLOUDS AND A FEW FLURRIES WILL BE
POSSIBLE. THE BEST CHANCE FOR ACCUMULATING SNOW WILL REMAIN EAST OR
MUNISING WHERE SOME LOCATIONS COULD SEE AN INCH OR TWO. THE CLOUDS
SHOULD KEEP TEMPS FROM FALLING OFF TOO FAR OVER THE CNTRL AND EAST
WITH READINGS FROM ZERO TO 5 ABOVE. OVER THE WEST...TEMPS COULD
STILL FALL INTO THE -5 TO -10 RANGE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 350 AM EST TUE FEB 4 2014
RELATIVELY BENIGN PATTERN THROUGH MOST OF THE LONG TERM...WITH SOME
A MORE ACTIVE PATTERN POSSIBLY SETTING UP EARLY NEXT WEEK. FOR THE
MOST PART...RAN WITH A CONSENSUS APPROACH TO THE FORECAST...WHICH
LEFT LOW CHANCE POPS AT BEST FOR PRECIP. WHILE STILL UNCERTAIN...THE
BEST CHANCE OF PRECIP MAY BE ON WED AS SOME HIGHER RES MODELS
INDICATE NNW LES OVER ERN ALGER AND NRN LUCE COUNTIES FROM THE MORE
OPEN WATERS OF FAR ERN LAKE SUPERIOR...BUT NOT SURE EXACTLY WHAT THE
EXTENT AND LOCATION OF THE BEST LES MAY BE. ALSO...WSW WINDS WILL
INCREASE THU INTO EARLY FRI AS A RESULT OF INCREASING PRESSURE
GRADIENT...WHICH MAY RESULT IN PATCHY BLOWING SNOW NEAR LAKE
SUPERIOR OVER NWRN UPPER MI. A SLOW AND SUBTLE WARMING TREND IS
POSSIBLE THROUGH NEXT WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1235 PM EST TUE FEB 4 2014
WITH A CHILLY UPSLOPE NNW FLOW OF COLD AIR DEVELOPING...EXPECT
PREDOMINANT HIGH END MVFR TO DOMINATE THE TAF SITES THROUGH MUCH OF
THE PERIOD. EXPECT VFR CONDITIONS AT IWD TO SAW TO LOWER TO HIGH END
MVFR BY LATE THIS AFTERNOON AS UPSLOPE WIND COMPONENT DRAWS LAKE
MOISTURE AND CLOUDS INTO THE AREA.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 243 PM EST MON FEB 3 2014
OVERALL...A FAIRLY QUIET PERIOD IS EXPECTED ON LAKE SUEPRIOR AS A
STRONG HIGH PRESSURE RIDGE NOSES EAST INTO LAKE SUPERIOR ON
TUESDAY. THIS HIGH WILL SLIDE SOUTHEAST THROUGH THE OHIO RIVER
VALLEY AND WHEN A LOW MOVES THROUGH HUDSON BAY...COULD SEE WESTERLY
WINDS INCREASING TO 30KTS ON THURSDAY. WITH MUCH OF THE LAKE ICE
COVERED...SHOULDN/T BE MUCH CONCERN FOR HEAVY FREEZING SPRAY. A
POCKET OF OPEN WATER NORTH AND EAST OF GRAND MARAIS MICHIGAN WILL
BRING THE POTENTIAL FOR HEAVY FREEZING SPRAY ON THURSDAY AND
THURSDAY NIGHT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...VOSS
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
659 AM EST TUE FEB 4 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 501 AM EST TUE FEB 4 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A TROUGH FROM HUDSON BAY INTO
MANITOBA AND SRN SASK AND A RIDGE OVER THE SE CONUS RESULTING IN WSW
MID/UPPER LEVEL NRN STREAM FLOW THROUGH THE WRN GREAT LAKES. AT THE
SFC...WEAK NW TO N FLOW HAD DEVELOPED OVER LAKE SUPERIOR BEHIND A
COLD FRONT EXTENDING FROM JAMES BAY INTO ERN UPPER MI AND CNTRL WI.
TO THE WEST...A RIDGE EXTENDED FROM WRN CANADA INTO THE NRN PLAINS.
THERE WAS ENOUGH TO MOISTURE BELOW THE 4K FT INVERSION FOR CLOUDS
ACROSS MUCH OF NRN ONTARIO LAKE SUPERIOR AND NRN UPPER MI. WITH 850
MB TEMPS TO AROUND -18C...RADAR INDICATED SOME LIGHT LES FROM
MARQUETTE TO MUNISING WHERE GAPS IN THE ICE COVER WERE PRESENT.
TODAY...SINCE A WEAK PRES GRADIENT AND LIGHT WINDS ARE EXPECTED
ACROSS LAKE SUPERIOR...ANY ADDITIONAL LES IS EXPECTED WILL BE
DISORGANIZED AND DIFFICULT TO PREDICT GIVEN THE EXTENSIVE ICE COVER.
THE BEST CHANCE FOR SOME LIGHT ACCUMULATIONS WILL BE INTO THE NE
CWA...CLOSER TO THE LARGER REMAINING AREA OF OPEN WATER. SOME
FLURRIES ARE ALSO EXPECTED TO PERSIST BETWEEN MARQUETTE AND MUNISING
DOWNWIND OF ANOTHER LIMITED STRETCH OF OPEN WATER.
OTHERWISE...PARTLY TO MOSTLY CLOUDY SKIES ARE EXPECTED ACROSS THE
NORTH WITH THE MOST SUNSHINE CLOSER TO THE WI BORDER. TEMPERATURES
WILL REMAIN BELOW NORMAL WITH HIGHS IN THE TEENS.
TONIGHT...THE GRADIENT WILL TIGHTEN AND ACYC NRLY FLOW WILL INCREASE
AS HIGH PRES BUILDS INTO THE NRN ONTARIO AND A LOW MOVES THROUGH THE
OH VALLEY. EVEN WITH LIMITED HEAT/MOISTURE FLUX ACROSS THE MOSTLY
ICE COVERED LAKE...SOME LAKE CLOUDS AND A FEW FLURRIES WILL BE
POSSIBLE. THE BEST CHANCE FOR ACCUMULATING SNOW WILL REMAIN EAST OR
MUNISING WHERE SOME LOCATIONS COULD SEE AN INCH OR TWO. THE CLOUDS
SHOULD KEEP TEMPS FROM FALLING OFF TOO FAR OVER THE CNTRL AND EAST
WITH READINGS FROM ZERO TO 5 ABOVE. OVER THE WEST...TEMPS COULD
STILL FALL INTO THE -5 TO -10 RANGE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 350 AM EST TUE FEB 4 2014
RELATIVELY BENIGN PATTERN THROUGH MOST OF THE LONG TERM...WITH SOME
A MORE ACTIVE PATTERN POSSIBLY SETTING UP EARLY NEXT WEEK. FOR THE
MOST PART...RAN WITH A CONSENSUS APPROACH TO THE FORECAST...WHICH
LEFT LOW CHANCE POPS AT BEST FOR PRECIP. WHILE STILL UNCERTAIN...THE
BEST CHANCE OF PRECIP MAY BE ON WED AS SOME HIGHER RES MODELS
INDICATE NNW LES OVER ERN ALGER AND NRN LUCE COUNTIES FROM THE MORE
OPEN WATERS OF FAR ERN LAKE SUPERIOR...BUT NOT SURE EXACTLY WHAT THE
EXTENT AND LOCATION OF THE BEST LES MAY BE. ALSO...WSW WINDS WILL
INCREASE THU INTO EARLY FRI AS A RESULT OF INCREASING PRESSURE
GRADIENT...WHICH MAY RESULT IN PATCHY BLOWING SNOW NEAR LAKE
SUPERIOR OVER NWRN UPPER MI. A SLOW AND SUBTLE WARMING TREND IS
POSSIBLE THROUGH NEXT WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 658 AM EST TUE FEB 4 2014
WITH UPSLOPE NW FLOW OF COLD AIR CONTINUING...EXPECT PREDOMINANT
HIGH END MVFR TO VFR CIGS TO DOMINATE CMX AND IWD THROUGH MUCH OF
THIS FCST PERIOD. THE BEST CHANCE FOR MORE SUSTAINED LOWER CONDITIONS
WILL BE AT CMX WITH A MORE PRONOUNCED UPSLOPE WIND COMPONENT.
DOWNSLOPE NATURE OF THIS FLOW INTO SAW SHOULD RESULT IN PREDOMINANT
VFR CONDITIONS THERE. LATER TODAY...A WIND SHIFT TOWARD THE N IN
ADVANCE OF ARCTIC HIGH PRES MOVING INTO THE NRN PLAINS MAY BRING THE
MVFR CIGS INTO IWD/SAW...WHERE THIS WIND WILL BRING AN UPSLOPE
COMPONENT.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 243 PM EST MON FEB 3 2014
OVERALL...A FAIRLY QUIET PERIOD IS EXPECTED ON LAKE SUEPRIOR AS A
STRONG HIGH PRESSURE RIDGE NOSES EAST INTO LAKE SUPERIOR ON
TUESDAY. THIS HIGH WILL SLIDE SOUTHEAST THROUGH THE OHIO RIVER
VALLEY AND WHEN A LOW MOVES THROUGH HUDSON BAY...COULD SEE WESTERLY
WINDS INCREASING TO 30KTS ON THURSDAY. WITH MUCH OF THE LAKE ICE
COVERED...SHOULDN/T BE MUCH CONCERN FOR HEAVY FREEZING SPRAY. A
POCKET OF OPEN WATER NORTH AND EAST OF GRAND MARAIS MICHIGAN WILL
BRING THE POTENTIAL FOR HEAVY FREEZING SPRAY ON THURSDAY AND
THURSDAY NIGHT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...JLB
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
502 AM EST TUE FEB 4 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 501 AM EST TUE FEB 4 2014
WV IMAGERY AND RUC ANALYSIS INDICATED TROUGH FROM HUDSON BAY INTO
MANITOBA AND SRN SASK AND A RIDGE OVER THE SE CONUS RESULTING IN WSW
MID/UPPER LEVEL NRN STREAM FLOW THROUGH THE WRN GREAT LAKES. AT THE
SFC...WEAK NW TO N FLOW HAD DEVELOPED OVER LAKE SUPERIOR BEHIND A
COLD FRONT EXTENDING FROM JAMES BAY INTO ERN UPPER MI AND CNTRL WI.
TO THE WEST...A RIDGE EXTENDED FROM WRN CANADA INTO THE NRN PLAINS.
THERE WAS ENOUGH TO MOISTURE BELOW THE 4K FT INVERSION FOR CLOUDS
ACROSS MUCH OF NRN ONTARIO LAKE SUPERIOR AND NRN UPPER MI. WITH 850
MB TEMPS TO AROUND -18C...RADAR INDICATED SOME LIGHT LES FROM
MARQUETTE TO MUNISING WHERE GAPS IN THE ICE COVER WERE PRESENT.
TODAY...SINCE A WEAK PRES GRADIENT AND LIGHT WINDS ARE EXPECTED
ACROSS LAKE SUPERIOR...ANY ADDITIONAL LES IS EXPECTED WILL BE
DISORGANIZED AND DIFFICULT TO PREDICT GIVEN THE EXTENSIVE ICE COVER.
THE BEST CHANCE FOR SOME LIGHT ACCUMULATIONS WILL BE INTO THE NE
CWA...CLOSER TO THE LARGER REMAINING AREA OF OPEN WATER. SOME
FLURRIES ARE ALSO EXPECTED TO PERSIST BETWEEN MARQUETTE AND MUNISING
DOWNWIND OF ANOTHER LIMITED STRETCH OF OPEN WATER.
OTHERWISE...PARTLY TO MOSTLY CLOUDY SKIES ARE EXPECTED ACROSS THE
NORTH WITH THE MOST SUNSHINE CLOSER TO THE WI BORDER. TEMPERATURES
WILL REMAIN BELOW NORMAL WITH HIGHS IN THE TEENS.
TONIGHT...THE GRADIENT WILL TIGHTEN AND ACYC NRLY FLOW WILL INCREASE
AS HIGH PRES BUILDS INTO THE NRN ONTARIO AND A LOW MOVES THROUGH THE
OH VALLEY. EVEN WITH LIMITED HEAT/MOISTURE FLUX ACROSS THE MOSTLY
ICE COVERED LAKE...SOME LAKE CLOUDS AND A FEW FLURRIES WILL BE
POSSIBLE. THE BEST CHANCE FOR ACCUMULATING SNOW WILL REMAIN EAST OR
MUNISING WHERE SOME LOCATIONS COULD SEE AN INCH OR TWO. THE CLOUDS
SHOULD KEEP TEMPS FROM FALLING OFF TOO FAR OVER THE CNTRL AND EAST
WITH READINGS FROM ZERO TO 5 ABOVE. OVER THE WEST...TEMPS COULD
STILL FALL INTO THE -5 TO -10 RANGE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 350 AM EST TUE FEB 4 2014
RELATIVELY BENIGN PATTERN THROUGH MOST OF THE LONG TERM...WITH SOME
A MORE ACTIVE PATTERN POSSIBLY SETTING UP EARLY NEXT WEEK. FOR THE
MOST PART...RAN WITH A CONSENSUS APPROACH TO THE FORECAST...WHICH
LEFT LOW CHANCE POPS AT BEST FOR PRECIP. WHILE STILL UNCERTAIN...THE
BEST CHANCE OF PRECIP MAY BE ON WED AS SOME HIGHER RES MODELS
INDICATE NNW LES OVER ERN ALGER AND NRN LUCE COUNTIES FROM THE MORE
OPEN WATERS OF FAR ERN LAKE SUPERIOR...BUT NOT SURE EXACTLY WHAT THE
EXTENT AND LOCATION OF THE BEST LES MAY BE. ALSO...WSW WINDS WILL
INCREASE THU INTO EARLY FRI AS A RESULT OF INCREASING PRESSURE
GRADIENT...WHICH MAY RESULT IN PATCHY BLOWING SNOW NEAR LAKE
SUPERIOR OVER NWRN UPPER MI. A SLOW AND SUBTLE WARMING TREND IS
POSSIBLE THROUGH NEXT WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1223 AM EST TUE FEB 4 2014
WITH A CHILLY UPSLOPE NW FLOW OF COLD AIR CONTINUING...EXPECT
PREDOMINANT HI END MVFR TO VFR CIGS TO DOMINATE CMX AND IWD THRU
MUCH OF THIS FCST PERIOD. BEST CHC FOR MORE SUSTAINED LOWER
CONDITIONS WL BE AT CMX WITH A MORE PRONOUNCED UPSLOPE WIND
COMPONENT. DOWNSLOPE NATURE OF THIS FLOW INTO SAW SHOULD RESULT IN
PREDOMINANT VFR CONDITIONS THERE. LATER TODAY...A WSHFT TOWARD THE N
IN ADVANCE OF ARCTIC HI PRES MOVING INTO THE NRN PLAINS MAY BRING
THE MVFR CIGS INTO IWD/SAW...WHERE THIS WIND WL PRESENT AN UPSLOPE
COMPONENT. WITH SOME DRYING AND A LESS FVRBL WIND...EXPECT VFR WX TO
PREVAIL AT CMX.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 243 PM EST MON FEB 3 2014
OVERALL...A FAIRLY QUIET PERIOD IS EXPECTED ON LAKE SUEPRIOR AS A
STRONG HIGH PRESSURE RIDGE NOSES EAST INTO LAKE SUPERIOR ON
TUESDAY. THIS HIGH WILL SLIDE SOUTHEAST THROUGH THE OHIO RIVER
VALLEY AND WHEN A LOW MOVES THROUGH HUDSON BAY...COULD SEE WESTERLY
WINDS INCREASING TO 30KTS ON THURSDAY. WITH MUCH OF THE LAKE ICE
COVERED...SHOULDN/T BE MUCH CONCERN FOR HEAVY FREEZING SPRAY. A
POCKET OF OPEN WATER NORTH AND EAST OF GRAND MARAIS MICHIGAN WILL
BRING THE POTENTIAL FOR HEAVY FREEZING SPRAY ON THURSDAY AND
THURSDAY NIGHT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...KC
MARINE...SRF
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
320 PM CST Tue Feb 4 2014
.SHORT TERM: (Tonight through Wednesday)
Issued at 318 PM CST Tue Feb 4 2014
No changes will be made to going warnings/advisories with some
minor changes to snowfall amounts, mainly to account for incoming
reports. The snow spread into the eastern counties this afternoon
with some minor accumulations reported in Fayette county. Some
sleet was reported mixing in with the snow down in Fredericktown
around 1230 pm and more recently in Maeystown in Monroe county
Illinois. Still expect this mix to continue over southeast
Missouri into south central Illinois into mid evening based on
most recent RAP soundings.
To the north and west, moderate to occasionally heavy snow continues
across central and northeast Missouri into west central Illinois
where visibilities at the observation sites remain in the 1/4 to 1/2
mile range. Latest runs of the HRRR and RAP show that the
deformation zone will continue to produce accumulating snow over the
warning area of into late tonight before the deformation zone lifts
out of the area. Just to the south, snow has been falling since
late morning over parts of southeast and east central Missouri,
though pockets of dry air in the lower atmosphere has hampered it`s
eastward progress. Now dry air is moving in from the southwest
which will begin to cut down on snowfall rates. Have left freezing
drizzle in overnight over the southern half of the CWA overnight has
deep ascent moves out leaving some low level ascent in deep
moisture. Still do not expected there to be enough ice accretion to
include any mention at this point. Also left area of blowing and
drifting snow in the warning area late tonight where the winds will
pick of late tonight. System will lift out of the area early on
Wednesday. Have just a chance of snow over northeastern half of the
CWA on Wednesday morning.
Went on the cooler side of guidance tonight and tomorrow for
temperatures where the deeper snow cover will be.
Britt
.LONG TERM: (Wednesday Night through Next Tuesday)
Issued at 318 PM CST Tue Feb 4 2014
The upper flow will deamplify in the wake of the current storm
system with a more progressive flow featuring broad troffing
dominating through at least the end of the week. This will assist
the expansive 1040+ mb Arctic high building into the region
Wednesday night into Thursday. The biggest issue during this time
frame is the temperatures. There is quite a range in the MOS with
much of the model 2m temperatures siding with the colder MAV.
Given the amount of fresh snow cover that will reside across the
CWA have sided towards the colder numbers even though ideal
radiational cooling conditions (i.e. light winds) won`t exist in
this time frame. The low ambient air temperatures and even modest
wind will result in dangerous bitterly cold wind chills of -15 to
-25 late Wednesday night-Thursday morning generally along and
north of I-70. Collaboration with surrounding offices resulted in
holding off on wind chill headlines, but these will ultimately be
needed and likely issued once the current storm exits. We will
continue to hammer the message of this bitter cold in the
remainder of our produce suite.
The Arctic high will shift quickly eastward on Thursday night-Friday
night due to the progressive flow. There will also be a good deal of
cloudiness within this flow that will create some havoc with
temperatures and lead to lower confidence in the mins on Thursday
night/Friday morning. We have been carrying some low pops on Thursday
night and I have kept some low/slight chance pops in the forecast
generally along and south of I-70. The NAM, local WRF, and SREF all
show some light QPF associated with a weak impulse in the flow aloft
and attendant weak WAA/lift, while the NAMX and other models dry up
any precipitation as it attempts to spread east from the
southern/central Plains.
The forecast for this weekend is still highly questionable with a
good deal of uncertainty. Model continuity and agreement has been
quite poor and the general pattern the models were showing yesterday
with an amplifying upper trof/low moving through the
southern/central Plains into the lower/mid MS valley region is no
longer present. The general solution today is less amplified overall
and shifted north, with any advertised upper low now over Iowa on
Saturday night. Our forecast represents a multi-model blend with
greater weighting towards the ECMWF and CMC GEM. This would suggest
potential for 2 waves of snow - the first would be a chance of snow
area-wide Friday night due to a lead progressive wave and attendant
WAA, and then another chance Saturday/Saturday night more focused
across the northern CWA associated with the more northern upper
trof/low. Yet another shortwave within the progressive flow could
bring a chance of snow late Monday night-Tuesday. One thing that we
have high confidence in for the extended forecast is that the cold
weather will persist through early next week with a continuation of
below average temperatures.
Glass
&&
.AVIATION: (For the 18z TAFs through 18z Wednesday Afternoon)
Issued at 1138 AM CST Tue Feb 4 2014
Winter storm impacting the area will produce widespread IFR flight
conditions this afternoon through tonight. A wedge of dry air
along the I-70 corridor in Illinois and down the I-44 corridor in
Missouri is keeping too much snow from developing in those areas,
but I expect it to fill in over the next 2 hours or so. After the
snow begins, expect IFR flight conditions to prevail in light to
moderate snow at least through the evening. Will likely see some
improvement after 06z from southwest to northeast as the storm
lifts northeast away from the region.
Specifics for KSTL:
IFR flight conditions will prevail at Lambert this afternoon into
tonight as a winter storm impacts the region. Snow is having a
little trouble developing initially due to a wedge of dry air over
the STL area. This wedge should fill in over the next hour or so
and I expect snow to continue through tonight. Atmospheric lift is
quite strong so heavier bands of snow with VSBYS down below
alternate minimums is likely. Intensity should slacken this evening
but I think IFR flight conditions will continue through most of
the night.
Carney
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...WINTER WEATHER ADVISORY until 6 AM CST Wednesday FOR Crawford MO-
Franklin MO-Gasconade MO-Iron MO-Jefferson MO-Madison MO-
Reynolds MO-St. Charles MO-St. Francois MO-St. Louis City
MO-St. Louis MO-Ste. Genevieve MO-Washington MO.
WINTER STORM WARNING until 6 AM CST Wednesday FOR Audrain MO-
Boone MO-Callaway MO-Cole MO-Knox MO-Lewis MO-Lincoln MO-
Marion MO-Moniteau MO-Monroe MO-Montgomery MO-Osage MO-Pike
MO-Ralls MO-Shelby MO-Warren MO.
IL...WINTER WEATHER ADVISORY until 6 AM CST Wednesday FOR Bond IL-
Clinton IL-Fayette IL-Madison IL-Marion IL-Monroe IL-
Randolph IL-St. Clair IL-Washington IL.
WINTER STORM WARNING until 6 AM CST Wednesday FOR Adams IL-Brown
IL-Calhoun IL-Greene IL-Jersey IL-Macoupin IL-Montgomery IL-
Pike IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
917 PM MST MON FEB 3 2014
.UPDATE...
UPDATED FORECAST TONIGHT TO LOWER SNOW ACCUMULATIONS AND INCREASE
BLOWING SNOW COVERAGE.
SNOW TOTALS FROM TODAY WERE MAINLY AROUND AN INCH WITH A FEW 2
INCH TYPE REPORTS THROWN IN. HOWEVER BLOWING AND DRIFTING SNOW
MADE ACCURATE MEASUREMENTS DIFFICULT AND THERE WERE MANY REPORTS
OF SIGNIFICANT DRIFTING SNOW. WE HAD 0.9 INCHES OF SNOWFALL AT
THE OFFICE AS OF 6 PM...AND 0.6 AT THE BILLINGS AIRPORT AS OF 4
PM.
LATEST NAM AND RAP ARE SHOWING A DISTINCT DECREASE IN LIFT
OVERNIGHT TONIGHT COMPARED TO EARLIER RUNS. BOTH MODELS SEEM TO BE
HANDLING THE CURRENT SITUATION WELL SO HAVE TRENDED FORECAST
SNOWFALL DOWN TO AROUND 2 INCHES FOR MOST LOCATIONS THROUGH
TONIGHT...WITH AN INCH OR LESS FOR MOST AREAS TOMORROW AS
DENDRITIC GROWTH DECREASES ALONG WITH AVAILABLE MOISTURE AND LIFT.
UPPER TROF SLIDES ACROSS THE AREA TONIGHT IN A MORE NORTHWEST TO
SOUTHEAST MANNER WHICH IS WHY LIFT IS WEAKER. QG FORCING REMAINS
OVER THE SOUTHERN HALF OF THE FORECAST AREA INTO TOMORROW WHICH IS
WHERE THE HEAVIER ACCUMULATIONS CAN BE EXPECTED DURING THE EARLY
MORNING HOURS. TEMPERATURES HAVE DROPPED INTO THE LOW SINGLE
DIGITS AND WILL CONTINUE TO SLIDE BELOW ZERO BY MORNING. PRESSURE
TRENDS ARE EXPECTED TO KEEP WIND SPEEDS GENERALLY IN THE 10 TO 20
MPH RANGE IN EXPOSED LOCATIONS WHICH WILL PRODUCE WIDESPREAD
BLOWING AND DRIFTING SNOW. DRIFTING SNOW MAY BE MORE OF A PROBLEM
THAN THE RESTRICTED VISIBILITY FROM BLOWING SNOW IN RURAL AREAS.
HAVE REPORTS OF DRIFTS SEVERAL FEET DEEP IN SOME AREAS. FOR
TRAVELERS...VEHICLES ARE BLOWING SNOW AROUND CAUSING VERY POOR
VISIBILITY ON HIGHWAYS THIS EVENING SO EXTRA CAUTION IS NEEDED
PASSING AND BEING PASSED TONIGHT...ESPECIALLY BY LARGER TRUCKS.
WIND CHILLS ALREADY APPROACHING ADVISORY LEVELS IN MANY AREAS THIS
EVENING AND SHOULD DROP TO UNDER 20 BELOW ZERO BEFORE SUNRISE
TOMORROW MORNING ACROSS THE AREA. ONLY CHANGES TO GOING HIGHLITES
WILL BE TO ADJUST SNOW ACCUMULATIONS. CHAMBERS
&&
.SHORT TERM...VALID FOR TUE AND WED...
MAIN CHANGES TO THE FORECAST WERE TO INCREASE SNOW AMOUNTS IN
SOME AREAS...ADD ROSEBUD...TREASURE AND POWDER RIVER TO THE
ADVISORY AND ADD A WIND CHILL ADVISORY FOR FALLON...CUSTER AND
CARTER COUNTIES. ALSO EMPHASIZED BLOWING SNOW IN AREAS FROM
BILLINGS W AND SW...AS WELL AS ADDED WIND CHILL WORDING TO MOST
SEGMENTS OF THE ADVISORY.
SHORTWAVE SEEN ON WATER VAPOR IMAGERY...ROTATING THROUGH THE
PACIFIC NW THIS AFTERNOON...WILL MOVE ONLY SLOWLY SE TONIGHT
THROUGH ID. THIS FEATURE WILL BRING Q-VECTOR CONVERGENCE TO THE
AREA WITH THE STRONGEST LIFT OVER WESTERN AND SOUTHERN SECTIONS OF
THE FORECAST AREA. WEAK FRONTOGENESIS WILL BE OVER THE AREA
TONIGHT AS WELL WHILE STRONGER FRONTOGENESIS MOVES OUT OF THE SW
PART OF REGION. UPSLOPE FLOW UP TO 7000 FEET WAS OVER THE AREA
THIS AFTERNOON AND WILL CONTINUE OVERNIGHT. TIME-HEIGHT CROSS
SECTIONS AND BUFKIT SHOWED OMEGA AND GOOD DENDRITIC GROWTH OVER
MUCH OF THE REGION THROUGH LATE THIS EVENING. THE ABOVE FACTORS
SUPPORTED RAISING SNOW AMOUNTS OVER THE AREA. WILL NEED TO WATCH
THE SW MOUNTAINS WHERE STRONG LIFT COULD PRODUCE WARNING SNOW
AMOUNTS. FOR NOW...HAD UP TO 10 INCHES IN THIS AREA.
GUSTY WINDS WERE OCCURRING FROM KBIL TO KLVM THIS AFTERNOON
CREATING BLOWING SNOW. THE WINDS WERE CAUSED BY A STRONG PRESSURE
GRADIENT BETWEEN HIGH PRESSURE N OF THE AREA AND LOW PRESSURE OVER
ID. HAVE RAISED WIND SPEEDS OVER THE SW PART OF THE AREA FROM KBIL
SW AND ADDED AREAS OF BLOWING SNOW TO THE FORECAST. THERE WILL BE
ENOUGH WIND OVER THE AREA TO SUPPORT WIND CHILL ADVISORY CRITERIA
WHEN COMBINED WITH TEMPERATURES FALLING BELOW ZERO. THUS ADDED THE
WIND CHILLS TO MOST SEGMENTS OF THE ADVISORY.
ON TUE...THE SHORTWAVE WILL BE OVER WY AND DENDRITIC GROWTH WILL
BE MUCH LESS AS 850 MB TEMPERATURES FALL INTO THE -20S C. LIGHT
UPSLOPE SNOW WILL CONTINUE OVER MUCH OF THE AREA WITH LITTLE
ACCUMULATION. HIGH TEMPERATURES WILL BE BELOW ZERO AND THE GUSTY
WINDS WILL CONTINUE FROM KBIL W AND SW DUE TO THE CONTINUED TIGHT
PRESSURE GRADIENT. WILL CONTINUE TO MENTION AREAS OF BLOWING SNOW
IN THIS REGION. WIND CHILLS WILL BE 20 TO 30 BELOW ZERO ACROSS THE
AREA.
FORCING WILL WEAKEN OVER THE REGION TUE NIGHT UNDER A COLD W TO E
ORIENTED TROUGH. QPF WILL TAPER OFF FROM N TO S OVER THE AREA...SO
CONTINUED THE LOWER POPS. WITH 850 MB TEMPERATURES IN THE -20S
C...HAVE LOWERED TEMPERATURES SOME MORE. WINDS WILL DIMINISH TUE
NIGHT AS THE 1056 MB HIGH SETTLES OVER THE REGION. THE ENDING
TIMES ON TUE NIGHT FOR THE ADVISORIES WERE IN GOOD SHAPE. ARTHUR
.LONG TERM...VALID FOR THU...FRI...SAT...SUN...MON...
MODELS REMAIN IN GOOD AGREEMENT AND HAVE MADE ONLY MINOR CHANGES
TO THE EXTENDED FORECAST. ARCTIC AIR WILL REMAIN ENTRENCHED OVER
THE AREA FOR WEDNESDAY THROUGH FRIDAY. THE COLDEST TEMPERATURES
WILL BE WEDNESDAY/WEDNESDAY NIGHT AS MODELS PROGG 850 MB
TEMPERATURES AROUND -26C OVER THE AREA. THIS WILL TRANSLATE INTO
AFTERNOON HIGH TEMPERATURES IN THE SINGLE DIGITS BELOW ZERO AND AN
OVERNIGHT LOW NEAR 20 BELOW ZERO. RECORD LOW TEMPERATURES WILL BE
POSSIBLE FOR BILLINGS AND LIVINGSTON. A VERY SLOW WARNING TREND
WILL BEGIN OVER THE AREA STARTING THURSDAY AS THE FLOW ALOFT
BECOMES NORTHWESTERLY. HIGH TEMPERATURES ON THURSDAY WILL BE IN
THE SINGLE DIGITS ABOVE ZERO BUT BY MONDAY...TEMPERATURES WILL BE
BACK INTO THE LOW TO MID 30S AS HEIGHTS CONTINUE TO SLOWLY
INCREASE ACROSS SC/SE MT.
AS FOR PRECIPITATION...ONLY ISOLATED SNOW SHOWERS ARE EXPECTED
OVER THE MOUNTAINS FOR WEDNESDAY THROUGH NEXT MONDAY. GFS/ECMWF
CARVE OUT A LARGE TROUGH OF LOW PRESSURE OVER THE ROCKIES BUT KEEP
ENERGY MOVING WELL SOUTH OF OUR AREA. RICHMOND
&&
.AVIATION...
LIGHT SNOW WILL CONTINUE THROUGHOUT THE NIGHT RESULTING IN
WIDESPREAD MVFR TO IFR AND OCCASIONAL LIFR CONDITIONS. AREA
MOUNTAINS WILL BE OBSCURED. GUSTY NORTHEAST TO EAST WINDS WILL
RESULT IN AREAS OF BLOWING SNOW AND REDUCED VISIBILITIES. HOOLEY
&&
.PRELIMINARY POINT TEMP/POPS...
TUE WED THU FRI SAT SUN MON
-----------------------------------------------------------
BIL 904/902 915/904 919/002 913/011 903/018 003/027 014/033
++/S 50/I 00/B 00/B 00/U 00/B 00/B
LVM 905/903 920/903 920/004 910/014 902/020 008/026 019/034
++/S 52/J 10/B 01/B 11/U 11/N 11/B
HDN 903/000 914/903 919/002 913/009 905/016 901/028 009/034
++/S 50/I 00/B 00/B 01/B 00/B 00/B
MLS 905/901 914/901 916/004 914/010 906/017 903/022 004/027
+8/S 20/I 00/U 00/B 12/J 11/B 10/B
4BQ 904/000 915/901 918/005 913/014 904/020 901/022 008/030
++/S 40/I 00/B 01/B 12/J 00/B 00/B
BHK 907/902 916/903 915/005 912/011 904/018 902/020 003/025
+7/S 20/I 00/B 01/B 22/J 10/B 00/B
SHR 903/901 916/904 918/004 912/014 904/019 003/025 013/033
++/S 61/I 00/B 01/U 00/B 00/B 00/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...WINTER WEATHER ADVISORY IN EFFECT UNTIL 6 PM MST TUESDAY FOR
ZONES 28-29-42-63.
WINTER WEATHER ADVISORY IN EFFECT UNTIL MIDNIGHT MST TUESDAY
NIGHT FOR ZONES 30-31-34>36-38>41-56>58-64>66.
WIND CHILL ADVISORY IN EFFECT FROM 5 AM TUESDAY TO MIDNIGHT
MST TUESDAY NIGHT FOR ZONES 32-33-37.
WY...WINTER WEATHER ADVISORY IN EFFECT UNTIL MIDNIGHT MST TUESDAY
NIGHT FOR ZONES 98-99.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
950 AM EST TUE FEB 4 2014
.SYNOPSIS...CHILLY HIGH PRESSURE WILL NOSE INTO THE REGION TODAY
FROM THE NORTH... AS A FRONTAL ZONE SLOWLY APPROACHES FROM THE
SOUTH. A LOW PRESSURE CENTER AND ASSOCIATED COLD FRONT WILL MOVE
INTO THE AREA FROM THE WEST LATE TONIGHT THROUGH WEDNESDAY. HIGH
PRESSURE WILL BUILD IN FROM THE WEST WEDNESDAY NIGHT THROUGH
THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 950 AM TUESDAY...
REST OF TODAY: EARLIER FORECAST ADJUSTMENTS TO A SLOWER ONSET TIME
OF ISENTROPIC LIFT-DRIVEN LIGHT RAIN STILL LOOKS GOOD. LATEST
SURFACE MAP SHOWS A 1033 MB HIGH CENTERED OVER LK ONTARIO NOSING
SOUTHWARD INTO CENTRAL NC. THE NORTHERN EXTENT OF THE PATCHY LIGHT
RAIN IS JUST NOW EDGING INTO FAR SOUTH-CENTRAL NC... AND THIS SHOULD
CONTINUE TO STEADILY EXPAND NORTHWARD AS THE STRENGTHENING WINDS
ALOFT LEAD TO INCREASED OVERRUNNING AND DEEPENING MOIST UPGLIDE ATOP
THE LOW LEVEL BOUNDARY (CLEARLY EVIDENT ON THE 12Z 925 MB ANALYSIS
ACROSS ERN NC AND FAR NRN SC) AS THE DAY WEARS ON. WILL FOLLOW THE
TIMING OF THE LATEST RAP MODEL... SHOWING HIGH POPS (BUT FAIRLY LOW
TOTAL QPF OF AROUND A TENTH OF AN INCH) SPREADING NORTHWARD ACROSS
CENTRAL NC... WITH BEST COVERAGE FOCUSING ON THE FAR WRN CWA WHERE
THE WINDS JUST ALOFT WILL BE STRONGEST YIELDING THE MORE INTENSE
UPGLIDE. EXPECT PRECIP CHANCES TO BE LARGELY CONFINED TO AREAS SOUTH
OF HIGHWAY 64 PRIOR TO 3 PM... WITH A NORTHWARD EXPANSION OVER THE
REST OF THE FORECAST AREA IN THE LATE AFTERNOON THROUGH VERY EARLY
EVENING. WITH THE EXCEPTION OF AREAS RIGHT NEAR THE VA BORDER THIS
MORNING... THE ENTIRE CWA WILL REMAIN BENEATH OVERCAST SKIES THROUGH
THE DAY... ALTHOUGH THESE CLOUDS AT LEAST INITIALLY WILL BE THIN (AS
SEEN ON AMDAR AIRCRAFT SOUNDINGS THIS MORNING)... ALLOWING AT LEAST
SOME INSOLATION. STILL ON TRACK TO REACH HIGHS OF 40-45... COOLEST
SW AND WARMEST NW AND FAR NORTH. -GIH
TONIGHT: THE BULK OF THE MEASURABLE LIGHT RAIN WILL END FROM SOUTH
TO NORTH ACROSS THE PIEDMONT DURING THE EVENING...BUT PERIODS OF
DRIZZLE WILL LINGER THROUGHOUT THE NIGHT AS THE SATURATED HYBRID CAD
LAYER LOWERS. AREAS OF FOG WILL ALSO BE PROBABLE...SOME LOCALLY
DENSE WEDNESDAY MORNING...AS TEMPERATURES SETTLE INTO THE MIDDLE TO
UPPER 30S - A SMALL DIURNAL RANGE OF JUST 2-5 DEGREES FROM EARLIER
HIGHS. THE STRENGTH OF THE LOW LEVEL INVERSION WILL UNDOUBTEDLY
ENSURE THE WARM FRONT WILL HOLD TO OUR SOUTH AND EAST...DESPITE WHAT
THE NWP GUIDANCE (ESPECIALLY THE GFS) SUGGESTS. IN FACT...IT IS
QUITE PROBABLE THAT THIS WARM FRONT WILL NEVER GET INTO CENTRAL NC
EVEN ON WED...BUT MORE ON THAT BELOW. -MWS
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 AM TUESDAY...
WEDNESDAY AND WEDNESDAY NIGHT: WITH THE WEDGE HANGING ON IN THE
MORNING...A WEAK LOW WILL GRADUALLY DEVELOP OVER THE OHIO VALLEY
EARLY WEDNESDAY AND TRACK NORTHEASTWARD ALONG THE SPINE OF THE
APPALACHIANS AND ACROSS THE UPPER MID-ATLANTIC STATES BY WEDNESDAY
AFTERNOON...USHERED ALONG QUICKLY BY A 150 KT UPPER LEVEL JET. A
COLD FRONT ASSOCIATED WITH THIS FEATURE WILL CROSS NC ON WEDNESDAY
WITH THE TIMING BECOMING A BIT MORE UNCERTAIN AS THE PARENT LOW
RACES OFF TO THE NORTHEAST...LEAVING THE FRONT TO LINGER BEHIND. THE
FORWARD PROGRESSION OF THE FRONT WILL HELP TO KNOCK OUT THE WEDGE
BUT IT MAY NOT OCCUR UNTIL VERY LATE IN THE DAY...AND THUS KEEPING
HIGH TEMPERATURES A LOT LOWER IN THE NW. BEST TIMING AT THIS POINT
LOOKS TO BE AFTER 21Z IN THE TRIAD AND LATER IN THE EVENING FOR
FAYETTEVILLE AND POINTS EAST. THIS MAY HELP TO SET UP A LARGER
DISPARITY IN MAXIMUM TEMPERATURES WITH THE EASTERN HALF OF THE CWA
HAVING MORE INFLUENCE FROM THE COASTAL FRONT. UPPER 50S TO LOW 60S
IN THE NW (AND THIS IS A GENEROUS ESTIMATE AT THIS POINT...REALLY
FEEL LIKE THESE TEMPS COULD BE A LOT LOWER IF THE WEDGE HOLDS IN.)
FOR HIGHS WITH LOW 70S IN THE SE. A WIDESPREAD QUARTER OF AN INCH OF
QPF CAN BE EXPECTED WITH THIS SYSTEM. SKIES WILL BECOME PARTLY
CLOUDY TO MOSTLY CLEAR AFTER THE FRONT PASSES AND WINDS WILL REMAIN
BREEZY OUT OF THE NORTHWEST OVERNIGHT. TEMPS WILL DROP TO THE LOWER
TO UPPER 30S NW TO SE.
THURSDAY AND THURSDAY NIGHT: HIGH PRESSURE WILL BEGIN TO SLOWLY
BUILD IN FROM THE WEST...AND WHILE THE HIGH IS VERY STRONG AT 1042
MB IT IS VERY FAR AWAY...OVER THE CENTRAL PLAINS TO START BEFORE
BUILDING EASTWARD THROUGHOUT THE DAY. WINDS WILL SHIFT TO
NORTHEASTERLY AND MAX TEMPS WILL RUN IN THE MID 40S TO LOWER 50S
NORTH TO SOUTH. THE HIGH REMAINS TO THE NORTHWEST OVERNIGHT THURSDAY
WITH LOWS GENERALLY IN THE LOW TO MID 30S. SOUTHWESTERLY FLOW AND
CLOUD COVER WILL KEEP TEMPERATURES FROM DIPPING INTO THE UPPER 20S.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 300 AM TUESDAY...
FRIDAY AND FRIDAY NIGHT: A WEAK HYBRID DAMMING SCENARIO WILL SET UP
FOR FRIDAY WHICH WILL IN GENERAL...LEAD TO A CLOUDY AND COOL DAY
ACROSS CENTRAL NC WITH HIGHS IN THE LOW 40S NW TO NEAR 50 IN THE SE.
WINDS WILL STILL BE OUT OF THE NORTHEAST AND A SLIGHT CHANCE OF
RAIN/DRIZZLE WILL PERSIST THROUGHOUT THE DAY. ACCUMULATIONS OF LESS
THAN A TENTH OF AN INCH ARE EXPECTED. LOWS IN THE LOW TO UPPER 30S
NW TO SE.
SATURDAY THROUGH MONDAY: THE REMAINING PORTION OF THE LONG TERM
LOOKS VERY UNCERTAIN AT THIS TIME WITH MODEL SOLUTIONS VARYING
WIDELY IN SPACE AND TIME. WHAT WE DO KNOW IS THAT THIS PERIOD WILL
BE VERY UNSETTLED WITH SOME FORM OF LOW OR LOWS MOVING THROUGH
ALTHOUGH THE TIMING APPEARS TO BE A VERY LOW CONFIDENCE FORECAST AT
THIS POINT. MODEL SOLUTIONS DIFFER WITH THE 00Z RUN SLOWING THINGS
DOWN AND BRINING A MILLER B TYPE SCENARIO THROUGH THE AREA OVERNIGHT
SUNDAY INTO MONDAY. THE ECMWF ON THE OTHER HAND HAS SPED THINGS UP
AND HAS BECOME MORE PROGRESSIVE WITH NOT ONE BUT TWO MILLER A TYPE
LOWS FOLLOWING EACH OTHER. THE FIRST PASSING ALONG THE NC COAST ON
SATURDAY AND A SECOND DOING THE SAME SUNDAY EVENING. WPC IS FAVORING
A SOLUTION LET BY THE ECMWF AT THIS TIME BUT CONFIDENCE IN THIS IS
LOW CITING ONLY A LITTLE BIT BETTER CONTINUITY OVERALL. WITH
SPECIFICS VERY MUCH IN DOUBT AT THIS TIME WILL KEEP PRECIPITATION
MAINLY LIQUID AS SUGGESTED BY THICKNESS VALUES. WHILE THE ECMWF
SHOWS PRECIP BEING OUT OF THE AREA BY MONDAY MORNING...IF GFS
SOLUTIONS IS CORRECT...THERE COULD BE SOME FREEZING RAIN ISSUES IN
THE TRIAD BUT THIS IS HIGHLY UNCERTAIN AT THIS TIME. HIGHS DURING
THIS TIME IN THE MID 40S TO LOW 50S NW TO SE WITH LOWS IN THE MID
30S TO LOW 40S SATURDAY AND LOW TO UPPER 30S SUNDAY NIGHT INTO
MONDAY MORNING. WE WILL BEGIN TO DRY OUT ON MONDAY BUT COLD AIR
ADVECTION SHOULD KEEP TEMPERATURES IN THE UPPER 30S TO MID 40S FOR
HIGHS WITH NW WINDS AT 10 TO 15 KTS.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
AS OF 650 AM TUESDAY...
MAINLY MVFR CEILINGS WILL PERSIST ACROSS CENTRAL NC THIS MORNING...
OWING TO RELATIVELY WARM AND MOIST AIR FROM THE SOUTHWEST UPGLIDING
ATOP CHILLY AND MOIST SURFACE HIGH PRESSURE AND ASSOCIATED
NORTHEASTERLY FLOW...RESULTING IN COLD AIR DAMMING. THE CEILINGS MAY
LOWER TO IFR/JUST BELOW 1000 FT...BETWEEN 13-16Z...BUT OCCURRENCE
SEEMS TOO SHORT-LIVED OR REMOTE TO INCLUDE IN THE TAFS. OTHERWISE...
THE UPGLIDING FLOW WILL CAUSE THE CLOUD LAYER TO DEEPEN SUCH THAT
LIGHT RAIN WILL DEVELOP AND SPREAD NORTHWARD ACROSS CENTRAL NC
TODAY...BEFORE TAPERING TO DRIZZLE WITH LOWERING OVERCAST AND
VISIBILITY RESTRICTIONS INTO LIFR-IFR RANGE TONIGHT. LOW LEVEL WIND
SHEAR WILL ALSO BE PROBABLE LATE TO NIGHT-EARLY WED...AS THE WIND
JUST ABOVE THE SURFACE ACCELERATE TO BETWEEN 40-50 KTS.
OUTLOOK: THE ADVERSE AVIATION CONDITIONS IN COLD AIR DAMMING WILL
IMPROVE ON WED...FIRST AT KFAY AND KRWI WHERE THE PASSAGE OF A WARM
FRONT BY MIDDAY WILL RESULT IN LIFTING/SCATTERING TO MVFR-
VFR...FOLLOWED BY THE AFTERNOON PASSAGE OF AN OCCLUDED/COLD FRONT
FROM THE WEST THAT WILL SCOUR THE DAMP COLD AIR DAMMING AIR MASS AND
BRING ABOUT A RETURN TO DRY VFR CONDITIONS FOR MOST OF THE REMAINDER
OF THE WEEK. ANOTHER LOW SYSTEM NEAR THE SOUTHEAST US COAST MAY
PROVIDE FOR A PERIOD OF SUB-VFR CONDITIONS ON FRI...PARTICULARLY AT
EASTERN TERMINALS...FOLLOWED BY YET ANOTHER LOW PRESSURE SYSTEM AND
ASSOCIATED SUB-VFR CONDITIONS AND RAIN THIS WEEKEND.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD/MWS
SHORT TERM...ELLIS
LONG TERM...ELLIS
AVIATION...MWS
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1255 PM EST TUE FEB 4 2014
.SYNOPSIS...
LOW PRESSURE SYSTEM WITH MULTIPLE PRECIPITATION TYPES LATE
TUESDAY. HIGH PRESSURE FOR THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
9 AM UPDATE. NO MAJOR CHANGES AT THIS POINT TO THE FORECAST. DID
TWEAK THE HOURLY TEMPERATURE GRIDS THIS MORNING TO REFLECT CURRENT
CONDITIONS. WILL BE MAKING DECISIONS LATER TODAY AS TO WHETHER OR
NOT TO ADD NORTHERN MOUNTAIN ZONES TO ANY SORT OF ADVISORY
HEADLINES...AND WHETHER OR NOT TO LEAVE CURRENT ADVISORIES HOISTED
IN OHIO...OR MAKE CHANGES.
PREVIOUS DISCUSSION...
WE GET RID OF ONE MESSY SYSTEM 24 HOURS AGO...AND STILL HAVE TO DEAL
WITH ITS AFTER EFFECTS FOR THE FORECAST THIS MORNING. SNOWFALL FROM
THE SYSTEM YESTERDAY WILL HAVE DIRECT IMPACT ON THE WEATHER THROUGH
TONIGHT...IN COMBINATION WITH SURFACE NORTHEAST WINDS AND WARM AIR
ADVECTION OFF THE SURFACE. NEVER A GOOD COMBINATION.
FIRST...LOW LEVEL STRATUS REMAINS STUBBORNLY IN PLACE ACROSS MUCH OF
THE LOWLANDS OF WEST VIRGINIA...WITH A SHARP CUT OFF MAINLY JUST
NORTH OF THE OHIO RIVER. THIS HAS WREAKED HAVOC WITH THE OVERNIGHT
LOWS...AS AREAS IN THE CLEAR...SUCH AS ATHENS...BOTTOMED OUT UNDER
EFFICIENT RADIATIONAL COOLING CONDITIONS AND DROPPED INTO THE LOWER
TEENS...WHILE UNDER THE STRATUS...IT COULD NOT DROP OUT OF THE MID
TO UPPER 20S. CLOUDS ALSO ENVELOPED THE SOUTHERN MOUNTAINS...WITH
BKW IN THEM MOST OF THE NIGHT. RAP SUGGESTING THIS WILL BE NOT BE IN
A HURRY TO EXIT TODAY...AND AS HAS BEEN THE CASE SINCE LAST
EVENING...WILL LIKELY NEED TO PUSH THE ENDING TIME OF THE LOW LEVEL
MOISTURE FURTHER INTO THE DAY AS THE MODELS TRY TO FIGURE OUT WHAT
TO DO WITH THIS MOISTURE. IN TERMS OF SKY COVERAGE...THERE WILL
LITTLE CONSEQUENCE HOWEVER...AS WE ARE ALREADY SEEING HIGH LEVEL
MOISTURE STREAMING IN FROM THE SOUTHWEST...AND SHOULD BE OVERCAST
THROUGH THE PERIOD.
PRECIPITATION MOVES IN...AND HAVE KEPT THE TIMING AHEAD OF THE
MODELS AS IS COMMON WITH THESE LOWER MISSISSIPPI VALLEY ORIGINATING
STORMS. NOW COMES THE FUN OF DETERMINING THE PRECIPITATION TYPE.
MOS GUIDANCE FROM ANY MODEL WAS LARGELY USELESS FOR TEMPERATURES
TODAY...AND FELT THE OPERATIONAL GFS MODEL TEMPERATURES HAD THE BEST
HANDLE ON THE SITUATION OVER THE OHIO VALLEY. AS MENTIONED
EARLIER...SNOW PACK AND NORTHEASTERLY SURFACE WINDS WILL STIFF ARM
THE WARM ADVECTION ALOFT...MAKING IT DIFFICULT TO EVENTUALLY SCOUR
OUT THE COOL AIR. AS A RESULT...TEMPERATURES NEAR THE FREEZING MARK
CAN BE EXPECTED OVER A LARGE PORTION OF SOUTHEAST OHIO AND INTO THE
PLEASANTS AND TYLER COUNTY AREAS...AS WELL AS BACK INTO NORTHEAST
KENTUCKY. WILL ALSO SEE A LITTLE BIT OF THE WET BULB EFFECT ALOFT AT
THE START OF THE PRECIPITATION WHICH WILL NOT HELP MATTERS IN TERMS
OF GETTING TEMPERATURES ABOVE FREEZING. RUNNING THE WEATHER
PROCEDURE USING MODEL ALOFT TEMPERATURES AND THE SURFACE...BASICALLY
IN A TOP DOWN METHOD...PRODUCED MULTIPLE PRECIPITATION TYPES IN
SOUTHEAST OHIO AND JUST ACROSS THE RIVER OVER OUR NORTHERN ZONES.
THIS WAS THE REASON FOR THE WINTER WEATHER ADVISORY. PERRY COUNTY
WAS AN EASY CALL FOR THE UPGRADE TO A WARNING GIVEN THE POTENTIAL
FOR ACCUMULATING SLEET AND SNOW ON TOP OF THE FREEZING RAIN THREAT.
PER USUAL...WE ARE ON THE GRADIENT. IMAGINE THAT. SO IT GOES WITHOUT
SAYING THAT ANY MISSES REGARDING THE TEMPERATURES COULD HAVE HUGE
IMPACT ON THE RAIN/FREEZING RAIN/SLEET/SNOW LINES AND TIMINGS...AS
WAS THE STRUGGLE LAST NIGHT AS THE SUB FREEZING AIR TRIED MIGHTILY
TO SINK SOUTHWARD. HAVE HOISTED A WINTER WEATHER ADVISORY FOR THE
OTHER COUNTIES IN THE MIXED PRECIPITATION. WANTED TO GIVE THE DAY
SHIFT WHAT WILL LIKELY BE SOME MUCH NEEDED FLEXIBILITY FOR SOME LATE
CHANGES TO THESE HEADLINES AS FAR AS EXPANSIONS OR UPGRADES DUE TO A
SOMEWHAT MEDIOCRE CONFIDENCE IN THE FORECAST THIS MORNING.
NOW IT IS IMPORTANT TO REMEMBER THE FLOOD WATCH THAT IS IN PLACE.
THERE IS 1 TO 2 INCHES OF WATER CWA WIDE THAT EITHER FELL AS RAIN OR
IS STORED IN SNOW...DEPENDING ON THE LOCATION. WITH A SATURATED
GROUND THAT MAY BE PARTIALLY FROZEN IN AREAS...RUNOFF FROM THE RAIN
THAT WILL FALL OVER THE REST OF THE AREA WILL TEST THE AREA
STREAMS...CREEKS...AND RIVERS AS ANOTHER 0.75 TO 1.5 INCHES OF RAIN
OR LIQUID EQUIVALENT ARE POSSIBLE. THE FACT THAT THIS RAIN WILL FALL
BASIN WIDE IS THE OTHER TROUBLING PART OF THIS EQUATION. IN
SOUTHEAST OHIO...THERE MAY BE A TOUCH OF A CONFLICT WITH A WINTER
STORM WARNING OR WINTER WEATHER ADVISORY WHERE SLEET AND SNOW ARE A
POSSIBILITY...BUT FEEL THIS FLOOD WATCH IS STILL WELL SERVED IN
THESE PARTS.
ON THE SYNOPTIC SCALE...AFTER THE LOW PRESSURE PASSES TO THE
NORTHEAST TONIGHT...A SHARP DRY SLOT IS EXPECTED TO FOLLOW...SO
THERE MAY ACTUALLY BE SOME BREAKS IN THE CLOUDS IN THE FAR
NORTHWESTERN ZONES OF SOUTHEAST OHIO BY 12Z WEDNESDAY.
NOT DONE YET.
SOUTHEAST UPSLOPE FLOW MAKES LIFE DIFFICULT ON THE OTHER SIDE OF THE
CWA. STILL WATCHING THE WARM AIR ADVECTION...BUT 925MB WINDS AND
TEMPERATURES SHOW COLD AIR DAMMING THAT WILL BE TOUGH TO ERODE.
MOIST UPSLOPE FLOW PROMISES TO KEEP THE TEMPERATURES FROM
CLIMBING...AND WITH THE WARM PUNCH ALOFT IN RAIN...FREEZING RAIN IS
A DISTINCT POSSIBILITY LATE THIS EVENING AND TONIGHT FOR THE
GREENBRIER AND CHEAT RIVER VALLEY. THE GFS TEMPERATURES WERE NOT AS
BULLISH ON THE COLD BIAS THAT APPEARS TO BE THE BETTER SOLUTION AS
MENTIONED ABOVE...AND THUS...FEAR THAT THE OUTPUT FROM USING THE
WEATHER PROCEDURE WAS MODEST FREEZING RAIN RELEGATED TO THE FAR
EASTERN FRINGES OF RANDOLPH AND POCAHONTAS COUNTIES. NO HEADLINE YET
HERE. WILL LOOK OVER THIS ONE MORE TIME BEFORE LEAVING FOR THE
NIGHT...BUT HOPING THE NEXT MODEL RUN IS MORE HELPFUL IN THE
TEMPERATURES OUT THAT WAY THAN IT WAS FOR THIS ISSUANCE.
THINK THAT IS IT. MY BRAIN IS SHOT.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
STORM SYSTEM IS PULLING OUT AT THE BEGINNING OF THE PERIOD. EXCEPT
FOR THE NAM...OTHER MODELS ARE IN GOOD AGREEMENT ON A FASTER TIMING
OF THE FRONT ACROSS THE AREA WEDNESDAY. FRONT AT 12Z WEDNESDAY
EXPECTED TO BE NEAR THE I79 CORRIDOR...WITH CAT POPS IN RAIN
PRECEDING THE FRONT. FRONT WITH THE ORGANIZED RAIN EXITS MOUNTAINS
BY 18Z. BEHIND THE FRONT...MODELS HAVE A TYPICAL DRY SLOT FOR THIS
UPPER PATTERN...THIS BEING A STRONG WEST TO SOUTHWEST UPPER FLOW
WITH SOUTHWEST WINDS BEHIND THE FRONT. THUS...WE HAVE A SLOT OF NO
POPS FOR A TIME BEHIND THE INITIAL FRONT BEFORE THE REAL COLD FRONT
SWEEPS SOUTHEAST DURING WEDNESDAY. EVEN WITH SOME LOW LEVEL MOISTURE
AND GOOD COLD ADVECTION IN WEST TO NORTHWEST FLOW BEHIND THIS
REINFORCING SHOT OF COLD AIR...WHERE TEMPERATURES WILL BE SLOWLY
FALLING DURING THE DAY...THE PATTERN IS NOT REALLY CONDUCIVE FOR
POST FRONTAL AND UPSLOPE RAIN SHOWERS THAT WOULD CHANGE TO SNOW
SHOWERS. LOW LEVELS WILL HAVE A DISTINCTIVE ANTICYCLONIC CURVATURE
TO THE FLOW...AND MOISTURE WILL BE ON THE SHALLOW SIDE. THUS...WE
WILL CONFINE ANY SHOWERS TO THE NORTH AND NORTHEAST PORTIONS OF THE
AREA. THESE WILL END WEDNESDAY NIGHT AS SNOW SHOWERS...BUT LITTLE
ACCUMULATIONS IF ANY. TEMPERATURES WILL FALL BACK THRU THE 30S
WEDNESDAY AFTERNOON AND DOWN THROUGH THE 20S WEDNESDAY NIGHT UNDER
SOME DECENT COLD ADVECTION. HIGH PRESSURE BUILDS IN FOR THURSDAY
WITH DECREASING CLOUDS...BUT MUCH COLDER WITH HIGH TEMPS MAINLY IN THE
20S. MODERATING TEMPS FRIDAY UNDER SUNSHINE AS HIGH PRESSURE SHIFTS
EAST.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
HARD TO FIGURE THE AMOUNT OF CLOUD COVER FOR THURSDAY NIGHT INTO
FRIDAY...WITH SOME WEAK WARM AIR ADVECTION AT 850 MB. ONLY POPS
WERE SOME TOKEN 20 PERCENTS FOR THE MOST PART. SO MAINLY DRY WEATHER
FIGURED THROUGH FRIDAY NIGHT.
MAIN BULK OF PCPN FORECAST TO ARRIVE LATE SATURDAY NIGHT INTO
SUNDAY...WILL KEEP LIKELY POPS FOR RAIN OR SNOW. SEEMS THE HIGHER
PCPN TOTALS WITH THIS STORM WILL BE TO OUR EAST...TOWARD THE COAST.
STILL LEFT CHANCE POPS ON SATURDAY. INITIAL SET UP ON SATURDAY HAS
MOISTURE MAX OVER THE CAROLINAS AND ANOTHER IN THE MIDWEST. RATHER
FRAGMENTED LEADING INTO THE MAIN EVENT.
COLDER AIR IN THE WAKE OF THE STORM WITH LINGERING SNOW SHOWERS
SUNDAY NIGHT INTO EARLY MONDAY.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
STUBBRON LOW LEVEL STRATUS CONTINUES TO LINGER ACROSS THE AREA
THIS AFTERNOON. EXPECT SOME LIFTING TO MVFR/LOW VFR...PARTICULARLY
ACROSS THE SOUTH INCLUDING AT KCRW...KBKW. MAY BE HARDER/LATER TO
CLEAR ACROSS THE NORTH. REGARDLESS...MAINLY BKN TO OVC SKIES FOR
THE ENTIRE TAF PERIOD.
ANOTHER LOW PRESSURE SYSTEM WILL MOVE INTO THE REGION LATER
TONIGHT. THIS WILL SPREAD PRECIPITATION...MAINLY IN THE FORM OF
RAIN ACROSS THE WV LOWLANDS AND SOUTHWEST VA...FREEZING RAIN
ACROSS THE NORTHERN MOUNTAINS...AND A MIXTURE OF
SNOW...SLEET...AND FREEZING RAIN ACROSS PARTS OF SOUTHEAST OHIO
AND EASTERN KY...WITH BULK OF PRECIPITATION BEGINNING AFTER 03Z
WEDNESDAY. EXPECT WIDESPREAD MVFR CONDITIONS DEVELOPING AFTER
03-06Z...WITH WIDESPREAD IFR/LIFR AND LOCAL VLIFR CONDITIONS
DEVELOPING 06-14Z...WITH WIDESPREAD MVFR AND LOCAL IFR CONDITIONS
AFTER 14Z AS THE LOW PULLS OFF TO THE NORTHEAST.
SURFACE WINDS FROM THE SOUTHEAST TODAY...AND GUSTY AT TIMES
PARTICULARLY ACROSS THE HIGHER TERRAIN COUNTIES...BECOMING SOUTH
TO SOUTHWEST AFTER 09Z...AND WESTERLY AFTER 14-16Z. OCCASIONAL
GUSTS OF UP TO 24 KTS ACROSS THE LOWLANDS...WITH GUSTS UP TO 35
KTS ACROSS THE HIGHER TERRAIN.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z WEDNESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING OF STRATUS EROSION MAY VARY. TIMING OF IFR
WITH THE NEXT LOW PRESSURE SYSTEM COULD VARY...AS WELL AS
PRECIPITATION ONSET TIMING.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EST 1HRLY 13 14 15 16 17 18 19 20 21 22 23 00
CRW CONSISTENCY H H H H H H M M M H L M
HTS CONSISTENCY M M H H H H M M H L H H
BKW CONSISTENCY L H M M H H M H H M M M
EKN CONSISTENCY M H H M M H H H H H M M
PKB CONSISTENCY H H H H H H H H H H H M
CKB CONSISTENCY H H H H H H H H H M M M
AFTER 18Z WEDNESDAY...
IFR POSSIBLE WEDNESDAY...PARTICULARLY ACROSS THE HIGHER TERRAIN IN
SNOW SHOWERS.
&&
.EQUIPMENT...
PKB ASOS HAS BEEN EXPERIENCING MALFUNCTIONS...RESULTING IN SOME
MISSING OR INCOMPLETE OBSERVATIONS. ELECTRONICS TECHNICIANS ARE
AWARE OF THE PROBLEM AND PARTS ARE BEING ACQUIRED.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FLOOD WATCH FROM 8 PM EST THIS EVENING THROUGH WEDNESDAY
MORNING FOR WVZ005>011-013>020-024>040-046-047.
WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 10 AM EST
WEDNESDAY FOR WVZ009>011.
OH...FLOOD WATCH FROM 8 PM EST THIS EVENING THROUGH WEDNESDAY
MORNING FOR OHZ067-075-076-083>087.
WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 10 AM EST
WEDNESDAY FOR OHZ067-075-076-083>085.
WINTER STORM WARNING FROM 5 PM THIS AFTERNOON TO 10 AM EST
WEDNESDAY FOR OHZ066.
KY...FLOOD WATCH FROM 8 PM EST THIS EVENING THROUGH WEDNESDAY
MORNING FOR KYZ101>103-105.
VA...FLOOD WATCH FROM 8 PM EST THIS EVENING THROUGH WEDNESDAY
MORNING FOR VAZ003-004.
&&
$$
SYNOPSIS...JMV/26
NEAR TERM...SL/26
SHORT TERM...JMV
LONG TERM...KTB
AVIATION...SL
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
906 AM EST TUE FEB 4 2014
.SYNOPSIS...
LOW PRESSURE SYSTEM WITH MULTIPLE PRECIPITATION TYPES LATE
TUESDAY. HIGH PRESSURE FOR THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
9 AM UPDATE. NO MAJOR CHANGES AT THIS POINT TO THE FORECAST. DID
TWEAK THE HOURLY TEMPERATURE GRIDS THIS MORNING TO REFLECT CURRENT
CONDITIONS. WILL BE MAKING DECISIONS LATER TODAY AS TO WHETHER OR
NOT TO ADD NORTHERN MOUNTAIN ZONES TO ANY SORT OF ADVISORY
HEADLINES...AND WHETHER OR NOT TO LEAVE CURRENT ADVISORIES HOISTED
IN OHIO...OR MAKE CHANGES.
PREVIOUS DISCUSSION...
WE GET RID OF ONE MESSY SYSTEM 24 HOURS AGO...AND STILL HAVE TO DEAL
WITH ITS AFTER EFFECTS FOR THE FORECAST THIS MORNING. SNOWFALL FROM
THE SYSTEM YESTERDAY WILL HAVE DIRECT IMPACT ON THE WEATHER THROUGH
TONIGHT...IN COMBINATION WITH SURFACE NORTHEAST WINDS AND WARM AIR
ADVECTION OFF THE SURFACE. NEVER A GOOD COMBINATION.
FIRST...LOW LEVEL STRATUS REMAINS STUBBORNLY IN PLACE ACROSS MUCH OF
THE LOWLANDS OF WEST VIRGINIA...WITH A SHARP CUT OFF MAINLY JUST
NORTH OF THE OHIO RIVER. THIS HAS WREAKED HAVOC WITH THE OVERNIGHT
LOWS...AS AREAS IN THE CLEAR...SUCH AS ATHENS...BOTTOMED OUT UNDER
EFFICIENT RADIATIONAL COOLING CONDITIONS AND DROPPED INTO THE LOWER
TEENS...WHILE UNDER THE STRATUS...IT COULD NOT DROP OUT OF THE MID
TO UPPER 20S. CLOUDS ALSO ENVELOPED THE SOUTHERN MOUNTAINS...WITH
BKW IN THEM MOST OF THE NIGHT. RAP SUGGESTING THIS WILL BE NOT BE IN
A HURRY TO EXIT TODAY...AND AS HAS BEEN THE CASE SINCE LAST
EVENING...WILL LIKELY NEED TO PUSH THE ENDING TIME OF THE LOW LEVEL
MOISTURE FURTHER INTO THE DAY AS THE MODELS TRY TO FIGURE OUT WHAT
TO DO WITH THIS MOISTURE. IN TERMS OF SKY COVERAGE...THERE WILL
LITTLE CONSEQUENCE HOWEVER...AS WE ARE ALREADY SEEING HIGH LEVEL
MOISTURE STREAMING IN FROM THE SOUTHWEST...AND SHOULD BE OVERCAST
THROUGH THE PERIOD.
PRECIPITATION MOVES IN...AND HAVE KEPT THE TIMING AHEAD OF THE
MODELS AS IS COMMON WITH THESE LOWER MISSISSIPPI VALLEY ORIGINATING
STORMS. NOW COMES THE FUN OF DETERMINING THE PRECIPITATION TYPE.
MOS GUIDANCE FROM ANY MODEL WAS LARGELY USELESS FOR TEMPERATURES
TODAY...AND FELT THE OPERATIONAL GFS MODEL TEMPERATURES HAD THE BEST
HANDLE ON THE SITUATION OVER THE OHIO VALLEY. AS MENTIONED
EARLIER...SNOW PACK AND NORTHEASTERLY SURFACE WINDS WILL STIFF ARM
THE WARM ADVECTION ALOFT...MAKING IT DIFFICULT TO EVENTUALLY SCOUR
OUT THE COOL AIR. AS A RESULT...TEMPERATURES NEAR THE FREEZING MARK
CAN BE EXPECTED OVER A LARGE PORTION OF SOUTHEAST OHIO AND INTO THE
PLEASANTS AND TYLER COUNTY AREAS...AS WELL AS BACK INTO NORTHEAST
KENTUCKY. WILL ALSO SEE A LITTLE BIT OF THE WET BULB EFFECT ALOFT AT
THE START OF THE PRECIPITATION WHICH WILL NOT HELP MATTERS IN TERMS
OF GETTING TEMPERATURES ABOVE FREEZING. RUNNING THE WEATHER
PROCEDURE USING MODEL ALOFT TEMPERATURES AND THE SURFACE...BASICALLY
IN A TOP DOWN METHOD...PRODUCED MULTIPLE PRECIPITATION TYPES IN
SOUTHEAST OHIO AND JUST ACROSS THE RIVER OVER OUR NORTHERN ZONES.
THIS WAS THE REASON FOR THE WINTER WEATHER ADVISORY. PERRY COUNTY
WAS AN EASY CALL FOR THE UPGRADE TO A WARNING GIVEN THE POTENTIAL
FOR ACCUMULATING SLEET AND SNOW ON TOP OF THE FREEZING RAIN THREAT.
PER USUAL...WE ARE ON THE GRADIENT. IMAGINE THAT. SO IT GOES WITHOUT
SAYING THAT ANY MISSES REGARDING THE TEMPERATURES COULD HAVE HUGE
IMPACT ON THE RAIN/FREEZING RAIN/SLEET/SNOW LINES AND TIMINGS...AS
WAS THE STRUGGLE LAST NIGHT AS THE SUB FREEZING AIR TRIED MIGHTILY
TO SINK SOUTHWARD. HAVE HOISTED A WINTER WEATHER ADVISORY FOR THE
OTHER COUNTIES IN THE MIXED PRECIPITATION. WANTED TO GIVE THE DAY
SHIFT WHAT WILL LIKELY BE SOME MUCH NEEDED FLEXIBILITY FOR SOME LATE
CHANGES TO THESE HEADLINES AS FAR AS EXPANSIONS OR UPGRADES DUE TO A
SOMEWHAT MEDIOCRE CONFIDENCE IN THE FORECAST THIS MORNING.
NOW IT IS IMPORTANT TO REMEMBER THE FLOOD WATCH THAT IS IN PLACE.
THERE IS 1 TO 2 INCHES OF WATER CWA WIDE THAT EITHER FELL AS RAIN OR
IS STORED IN SNOW...DEPENDING ON THE LOCATION. WITH A SATURATED
GROUND THAT MAY BE PARTIALLY FROZEN IN AREAS...RUNOFF FROM THE RAIN
THAT WILL FALL OVER THE REST OF THE AREA WILL TEST THE AREA
STREAMS...CREEKS...AND RIVERS AS ANOTHER 0.75 TO 1.5 INCHES OF RAIN
OR LIQUID EQUIVALENT ARE POSSIBLE. THE FACT THAT THIS RAIN WILL FALL
BASIN WIDE IS THE OTHER TROUBLING PART OF THIS EQUATION. IN
SOUTHEAST OHIO...THERE MAY BE A TOUCH OF A CONFLICT WITH A WINTER
STORM WARNING OR WINTER WEATHER ADVISORY WHERE SLEET AND SNOW ARE A
POSSIBILITY...BUT FEEL THIS FLOOD WATCH IS STILL WELL SERVED IN
THESE PARTS.
ON THE SYNOPTIC SCALE...AFTER THE LOW PRESSURE PASSES TO THE
NORTHEAST TONIGHT...A SHARP DRY SLOT IS EXPECTED TO FOLLOW...SO
THERE MAY ACTUALLY BE SOME BREAKS IN THE CLOUDS IN THE FAR
NORTHWESTERN ZONES OF SOUTHEAST OHIO BY 12Z WEDNESDAY.
NOT DONE YET.
SOUTHEAST UPSLOPE FLOW MAKES LIFE DIFFICULT ON THE OTHER SIDE OF THE
CWA. STILL WATCHING THE WARM AIR ADVECTION...BUT 925MB WINDS AND
TEMPERATURES SHOW COLD AIR DAMMING THAT WILL BE TOUGH TO ERODE.
MOIST UPSLOPE FLOW PROMISES TO KEEP THE TEMPERATURES FROM
CLIMBING...AND WITH THE WARM PUNCH ALOFT IN RAIN...FREEZING RAIN IS
A DISTINCT POSSIBILITY LATE THIS EVENING AND TONIGHT FOR THE
GREENBRIER AND CHEAT RIVER VALLEY. THE GFS TEMPERATURES WERE NOT AS
BULLISH ON THE COLD BIAS THAT APPEARS TO BE THE BETTER SOLUTION AS
MENTIONED ABOVE...AND THUS...FEAR THAT THE OUTPUT FROM USING THE
WEATHER PROCEDURE WAS MODEST FREEZING RAIN RELEGATED TO THE FAR
EASTERN FRINGES OF RANDOLPH AND POCAHONTAS COUNTIES. NO HEADLINE YET
HERE. WILL LOOK OVER THIS ONE MORE TIME BEFORE LEAVING FOR THE
NIGHT...BUT HOPING THE NEXT MODEL RUN IS MORE HELPFUL IN THE
TEMPERATURES OUT THAT WAY THAN IT WAS FOR THIS ISSUANCE.
THINK THAT IS IT. MY BRAIN IS SHOT.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
STORM SYSTEM IS PULLING OUT AT THE BEGINNING OF THE PERIOD. EXCEPT
FOR THE NAM...OTHER MODELS ARE IN GOOD AGREEMENT ON A FASTER TIMING
OF THE FRONT ACROSS THE AREA WEDNESDAY. FRONT AT 12Z WEDNESDAY
EXPECTED TO BE NEAR THE I79 CORRIDOR...WITH CAT POPS IN RAIN
PRECEDING THE FRONT. FRONT WITH THE ORGANIZED RAIN EXITS MOUNTAINS
BY 18Z. BEHIND THE FRONT...MODELS HAVE A TYPICAL DRY SLOT FOR THIS
UPPER PATTERN...THIS BEING A STRONG WEST TO SOUTHWEST UPPER FLOW
WITH SOUTHWEST WINDS BEHIND THE FRONT. THUS...WE HAVE A SLOT OF NO
POPS FOR A TIME BEHIND THE INITIAL FRONT BEFORE THE REAL COLD FRONT
SWEEPS SOUTHEAST DURING WEDNESDAY. EVEN WITH SOME LOW LEVEL MOISTURE
AND GOOD COLD ADVECTION IN WEST TO NORTHWEST FLOW BEHIND THIS
REINFORCING SHOT OF COLD AIR...WHERE TEMPERATURES WILL BE SLOWLY
FALLING DURING THE DAY...THE PATTERN IS NOT REALLY CONDUCIVE FOR
POST FRONTAL AND UPSLOPE RAIN SHOWERS THAT WOULD CHANGE TO SNOW
SHOWERS. LOW LEVELS WILL HAVE A DISTINCTIVE ANTICYCLONIC CURVATURE
TO THE FLOW...AND MOISTURE WILL BE ON THE SHALLOW SIDE. THUS...WE
WILL CONFINE ANY SHOWERS TO THE NORTH AND NORTHEAST PORTIONS OF THE
AREA. THESE WILL END WEDNESDAY NIGHT AS SNOW SHOWERS...BUT LITTLE
ACCUMULATIONS IF ANY. TEMPERATURES WILL FALL BACK THRU THE 30S
WEDNESDAY AFTERNOON AND DOWN THROUGH THE 20S WEDNESDAY NIGHT UNDER
SOME DECENT COLD ADVECTION. HIGH PRESSURE BUILDS IN FOR THURSDAY
WITH DECREASING CLOUDS...BUT MUCH COLDER WITH HIGH TEMPS MAINLY IN THE
20S. MODERATING TEMPS FRIDAY UNDER SUNSHINE AS HIGH PRESSURE SHIFTS
EAST.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
HARD TO FIGURE THE AMOUNT OF CLOUD COVER FOR THURSDAY NIGHT INTO
FRIDAY...WITH SOME WEAK WARM AIR ADVECTION AT 850 MB. ONLY POPS
WERE SOME TOKEN 20 PERCENTS FOR THE MOST PART. SO MAINLY DRY WEATHER
FIGURED THROUGH FRIDAY NIGHT.
MAIN BULK OF PCPN FORECAST TO ARRIVE LATE SATURDAY NIGHT INTO
SUNDAY...WILL KEEP LIKELY POPS FOR RAIN OR SNOW. SEEMS THE HIGHER
PCPN TOTALS WITH THIS STORM WILL BE TO OUR EAST...TOWARD THE COAST.
STILL LEFT CHANCE POPS ON SATURDAY. INITIAL SET UP ON SATURDAY HAS
MOISTURE MAX OVER THE CAROLINAS AND ANOTHER IN THE MIDWEST. RATHER
FRAGMENTED LEADING INTO THE MAIN EVENT.
COLDER AIR IN THE WAKE OF THE STORM WITH LINGERING SNOW SHOWERS
SUNDAY NIGHT INTO EARLY MONDAY.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
IFR TO MVFR CEILINGS REMAIN IN PLACE WITH THE LOW LEVEL
STRATUS...AND EXPECT IMPROVEMENT TO VFR GENERALLY AFTER 16Z TODAY.
BKW IS THE ONLY TERMINAL THAT MAY NOT COME ABOVE MVFR CONDITIONS
AND HAVE THE TAF PESSIMISTIC IN THIS CASE. THE RAP MODEL WAS
HANDLING THIS THE BEST.
LOW PRESSURE SYSTEM MOVES IN FROM THE SOUTHWEST...WITH THE
CEILINGS LOWERING AGAIN FROM THE TOP DOWN. EXPECTING IFR TO LIFR
CEILINGS TONIGHT IN PRECIPITATION WHICH WILL MAINLY BE RAIN ACROSS
THE AREA. PKB MAY BE DEALING WITH FREEZING RAIN OR SLEET AT TIMES
WITH THE ONSET OF THE PRECIPITATION...AND SHOULD CHANGE TO RAIN
LATER TONIGHT.
BRING THE VISIBILITIES DOWN TO IFR TONIGHT IN RAIN WHEN THE WINDS
DROP BELOW 5KTS.
SURFACE FLOW NORTHEAST TODAY AND TONIGHT AROUND 10KTS FOR THE
LOWLAND TERMINALS OF CRW...PKB...HTS...AND CKB. EKN AND BKW WILL
HAVE A SOUTHEAST FLOW AT THE SURFACE...WHERE BKW MAY GUST TO
20KTS.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z WEDNESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING OF STRATUS EROSION MAY VARY. TIMING OF IFR
WITH THE NEXT LOW PRESSURE SYSTEM COULD VARY...AS WELL AS
PRECIPITATION ONSET TIMING.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
EST 1HRLY 09 10 11 12 13 14 15 16 17 18 19 20
CRW CONSISTENCY L L H H H H H H H H M M
HTS CONSISTENCY M M H H H H H H H H M H
BKW CONSISTENCY H L L H M M H H H H H H
EKN CONSISTENCY L L H H H H H H H H M M
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY M H H H H H H H H M H H
AFTER 12Z WEDNESDAY...
IFR POSSIBLE IN RAIN EARLY WEDNESDAY.
&&
.EQUIPMENT...
PKB ASOS HAS BEEN EXPERIENCING MALFUNCTIONS...RESULTING IN SOME
MISSING OR INCOMPLETE OBSERVATIONS. ELECTRONICS TECHNICIANS ARE
AWARE OF THE PROBLEM AND PARTS ARE BEING ACQUIRED.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FLOOD WATCH FROM 8 PM EST THIS EVENING THROUGH WEDNESDAY
MORNING FOR WVZ005>011-013>020-024>040-046-047.
WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 10 AM EST
WEDNESDAY FOR WVZ009>011.
OH...FLOOD WATCH FROM 8 PM EST THIS EVENING THROUGH WEDNESDAY
MORNING FOR OHZ067-075-076-083>087.
WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 10 AM EST
WEDNESDAY FOR OHZ067-075-076-083>085.
WINTER STORM WARNING FROM 5 PM THIS AFTERNOON TO 10 AM EST
WEDNESDAY FOR OHZ066.
KY...FLOOD WATCH FROM 8 PM EST THIS EVENING THROUGH WEDNESDAY
MORNING FOR KYZ101>103-105.
VA...FLOOD WATCH FROM 8 PM EST THIS EVENING THROUGH WEDNESDAY
MORNING FOR VAZ003-004.
&&
$$
SYNOPSIS...JMV/26
NEAR TERM...SL/26
SHORT TERM...JMV
LONG TERM...KTB
AVIATION...26
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
547 AM EST TUE FEB 4 2014
.SYNOPSIS...
LOW PRESSURE SYSTEM WITH MULTIPLE PRECIPITATION TYPES LATE
TUESDAY. HIGH PRESSURE FOR THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
NO CHANGES THIS MORNING TO THE FORECAST PACKAGE.
PREVIOUS DISCUSSION...
WE GET RID OF ONE MESSY SYSTEM 24 HOURS AGO...AND STILL HAVE TO DEAL
WITH ITS AFTER EFFECTS FOR THE FORECAST THIS MORNING. SNOWFALL FROM
THE SYSTEM YESTERDAY WILL HAVE DIRECT IMPACT ON THE WEATHER THROUGH
TONIGHT...IN COMBINATION WITH SURFACE NORTHEAST WINDS AND WARM AIR
ADVECTION OFF THE SURFACE. NEVER A GOOD COMBINATION.
FIRST...LOW LEVEL STRATUS REMAINS STUBBORNLY IN PLACE ACROSS MUCH OF
THE LOWLANDS OF WEST VIRGINIA...WITH A SHARP CUT OFF MAINLY JUST
NORTH OF THE OHIO RIVER. THIS HAS WREAKED HAVOC WITH THE OVERNIGHT
LOWS...AS AREAS IN THE CLEAR...SUCH AS ATHENS...BOTTOMED OUT UNDER
EFFICIENT RADIATIONAL COOLING CONDITIONS AND DROPPED INTO THE LOWER
TEENS...WHILE UNDER THE STRATUS...IT COULD NOT DROP OUT OF THE MID
TO UPPER 20S. CLOUDS ALSO ENVELOPED THE SOUTHERN MOUNTAINS...WITH
BKW IN THEM MOST OF THE NIGHT. RAP SUGGESTING THIS WILL BE NOT BE IN
A HURRY TO EXIT TODAY...AND AS HAS BEEN THE CASE SINCE LAST
EVENING...WILL LIKELY NEED TO PUSH THE ENDING TIME OF THE LOW LEVEL
MOISTURE FURTHER INTO THE DAY AS THE MODELS TRY TO FIGURE OUT WHAT
TO DO WITH THIS MOISTURE. IN TERMS OF SKY COVERAGE...THERE WILL
LITTLE CONSEQUENCE HOWEVER...AS WE ARE ALREADY SEEING HIGH LEVEL
MOISTURE STREAMING IN FROM THE SOUTHWEST...AND SHOULD BE OVERCAST
THROUGH THE PERIOD.
PRECIPITATION MOVES IN...AND HAVE KEPT THE TIMING AHEAD OF THE
MODELS AS IS COMMON WITH THESE LOWER MISSISSIPPI VALLEY ORIGINATING
STORMS. NOW COMES THE FUN OF DETERMINING THE PRECIPITATION TYPE.
MOS GUIDANCE FROM ANY MODEL WAS LARGELY USELESS FOR TEMPERATURES
TODAY...AND FELT THE OPERATIONAL GFS MODEL TEMPERATURES HAD THE BEST
HANDLE ON THE SITUATION OVER THE OHIO VALLEY. AS MENTIONED
EARLIER...SNOW PACK AND NORTHEASTERLY SURFACE WINDS WILL STIFF ARM
THE WARM ADVECTION ALOFT...MAKING IT DIFFICULT TO EVENTUALLY SCOUR
OUT THE COOL AIR. AS A RESULT...TEMPERATURES NEAR THE FREEZING MARK
CAN BE EXPECTED OVER A LARGE PORTION OF SOUTHEAST OHIO AND INTO THE
PLEASANTS AND TYLER COUNTY AREAS...AS WELL AS BACK INTO NORTHEAST
KENTUCKY. WILL ALSO SEE A LITTLE BIT OF THE WET BULB EFFECT ALOFT AT
THE START OF THE PRECIPITATION WHICH WILL NOT HELP MATTERS IN TERMS
OF GETTING TEMPERATURES ABOVE FREEZING. RUNNING THE WEATHER
PROCEDURE USING MODEL ALOFT TEMPERATURES AND THE SURFACE...BASICALLY
IN A TOP DOWN METHOD...PRODUCED MULTIPLE PRECIPITATION TYPES IN
SOUTHEAST OHIO AND JUST ACROSS THE RIVER OVER OUR NORTHERN ZONES.
THIS WAS THE REASON FOR THE WINTER WEATHER ADVISORY. PERRY COUNTY
WAS AN EASY CALL FOR THE UPGRADE TO A WARNING GIVEN THE POTENTIAL
FOR ACCUMULATING SLEET AND SNOW ON TOP OF THE FREEZING RAIN THREAT.
PER USUAL...WE ARE ON THE GRADIENT. IMAGINE THAT. SO IT GOES WITHOUT
SAYING THAT ANY MISSES REGARDING THE TEMPERATURES COULD HAVE HUGE
IMPACT ON THE RAIN/FREEZING RAIN/SLEET/SNOW LINES AND TIMINGS...AS
WAS THE STRUGGLE LAST NIGHT AS THE SUB FREEZING AIR TRIED MIGHTILY
TO SINK SOUTHWARD. HAVE HOISTED A WINTER WEATHER ADVISORY FOR THE
OTHER COUNTIES IN THE MIXED PRECIPITATION. WANTED TO GIVE THE DAY
SHIFT WHAT WILL LIKELY BE SOME MUCH NEEDED FLEXIBILITY FOR SOME LATE
CHANGES TO THESE HEADLINES AS FAR AS EXPANSIONS OR UPGRADES DUE TO A
SOMEWHAT MEDIOCRE CONFIDENCE IN THE FORECAST THIS MORNING.
NOW IT IS IMPORTANT TO REMEMBER THE FLOOD WATCH THAT IS IN PLACE.
THERE IS 1 TO 2 INCHES OF WATER CWA WIDE THAT EITHER FELL AS RAIN OR
IS STORED IN SNOW...DEPENDING ON THE LOCATION. WITH A SATURATED
GROUND THAT MAY BE PARTIALLY FROZEN IN AREAS...RUNOFF FROM THE RAIN
THAT WILL FALL OVER THE REST OF THE AREA WILL TEST THE AREA
STREAMS...CREEKS...AND RIVERS AS ANOTHER 0.75 TO 1.5 INCHES OF RAIN
OR LIQUID EQUIVALENT ARE POSSIBLE. THE FACT THAT THIS RAIN WILL FALL
BASIN WIDE IS THE OTHER TROUBLING PART OF THIS EQUATION. IN
SOUTHEAST OHIO...THERE MAY BE A TOUCH OF A CONFLICT WITH A WINTER
STORM WARNING OR WINTER WEATHER ADVISORY WHERE SLEET AND SNOW ARE A
POSSIBILITY...BUT FEEL THIS FLOOD WATCH IS STILL WELL SERVED IN
THESE PARTS.
ON THE SYNOPTIC SCALE...AFTER THE LOW PRESSURE PASSES TO THE
NORTHEAST TONIGHT...A SHARP DRY SLOT IS EXPECTED TO FOLLOW...SO
THERE MAY ACTUALLY BE SOME BREAKS IN THE CLOUDS IN THE FAR
NORTHWESTERN ZONES OF SOUTHEAST OHIO BY 12Z WEDNESDAY.
NOT DONE YET.
SOUTHEAST UPSLOPE FLOW MAKES LIFE DIFFICULT ON THE OTHER SIDE OF THE
CWA. STILL WATCHING THE WARM AIR ADVECTION...BUT 925MB WINDS AND
TEMPERATURES SHOW COLD AIR DAMMING THAT WILL BE TOUGH TO ERODE.
MOIST UPSLOPE FLOW PROMISES TO KEEP THE TEMPERATURES FROM
CLIMBING...AND WITH THE WARM PUNCH ALOFT IN RAIN...FREEZING RAIN IS
A DISTINCT POSSIBILITY LATE THIS EVENING AND TONIGHT FOR THE
GREENBRIER AND CHEAT RIVER VALLEY. THE GFS TEMPERATURES WERE NOT AS
BULLISH ON THE COLD BIAS THAT APPEARS TO BE THE BETTER SOLUTION AS
MENTIONED ABOVE...AND THUS...FEAR THAT THE OUTPUT FROM USING THE
WEATHER PROCEDURE WAS MODEST FREEZING RAIN RELEGATED TO THE FAR
EASTERN FRINGES OF RANDOLPH AND POCAHONTAS COUNTIES. NO HEADLINE YET
HERE. WILL LOOK OVER THIS ONE MORE TIME BEFORE LEAVING FOR THE
NIGHT...BUT HOPING THE NEXT MODEL RUN IS MORE HELPFUL IN THE
TEMPERATURES OUT THAT WAY THAN IT WAS FOR THIS ISSUANCE.
THINK THAT IS IT. MY BRAIN IS SHOT.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
STORM SYSTEM IS PULLING OUT AT THE BEGINNING OF THE PERIOD. EXCEPT
FOR THE NAM...OTHER MODELS ARE IN GOOD AGREEMENT ON A FASTER TIMING
OF THE FRONT ACROSS THE AREA WEDNESDAY. FRONT AT 12Z WEDNESDAY
EXPECTED TO BE NEAR THE I79 CORRIDOR...WITH CAT POPS IN RAIN
PRECEDING THE FRONT. FRONT WITH THE ORGANIZED RAIN EXITS MOUNTAINS
BY 18Z. BEHIND THE FRONT...MODELS HAVE A TYPICAL DRY SLOT FOR THIS
UPPER PATTERN...THIS BEING A STRONG WEST TO SOUTHWEST UPPER FLOW
WITH SOUTHWEST WINDS BEHIND THE FRONT. THUS...WE HAVE A SLOT OF NO
POPS FOR A TIME BEHIND THE INITIAL FRONT BEFORE THE REAL COLD FRONT
SWEEPS SOUTHEAST DURING WEDNESDAY. EVEN WITH SOME LOW LEVEL MOISTURE
AND GOOD COLD ADVECTION IN WEST TO NORTHWEST FLOW BEHIND THIS
REINFORCING SHOT OF COLD AIR...WHERE TEMPERATURES WILL BE SLOWLY
FALLING DURING THE DAY...THE PATTERN IS NOT REALLY CONDUCIVE FOR
POST FRONTAL AND UPSLOPE RAIN SHOWERS THAT WOULD CHANGE TO SNOW
SHOWERS. LOW LEVELS WILL HAVE A DISTINCTIVE ANTICYCLONIC CURVATURE
TO THE FLOW...AND MOISTURE WILL BE ON THE SHALLOW SIDE. THUS...WE
WILL CONFINE ANY SHOWERS TO THE NORTH AND NORTHEAST PORTIONS OF THE
AREA. THESE WILL END WEDNESDAY NIGHT AS SNOW SHOWERS...BUT LITTLE
ACCUMULATIONS IF ANY. TEMPERATURES WILL FALL BACK THRU THE 30S
WEDNESDAY AFTERNOON AND DOWN THROUGH THE 20S WEDNESDAY NIGHT UNDER
SOME DECENT COLD ADVECTION. HIGH PRESSURE BUILDS IN FOR THURSDAY
WITH DECREASING CLOUDS...BUT MUCH COLDER WITH HIGH TEMPS MAINLY IN THE
20S. MODERATING TEMPS FRIDAY UNDER SUNSHINE AS HIGH PRESSURE SHIFTS
EAST.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
HARD TO FIGURE THE AMOUNT OF CLOUD COVER FOR THURSDAY NIGHT INTO
FRIDAY...WITH SOME WEAK WARM AIR ADVECTION AT 850 MB. ONLY POPS
WERE SOME TOKEN 20 PERCENTS FOR THE MOST PART. SO MAINLY DRY WEATHER
FIGURED THROUGH FRIDAY NIGHT.
MAIN BULK OF PCPN FORECAST TO ARRIVE LATE SATURDAY NIGHT INTO
SUNDAY...WILL KEEP LIKELY POPS FOR RAIN OR SNOW. SEEMS THE HIGHER
PCPN TOTALS WITH THIS STORM WILL BE TO OUR EAST...TOWARD THE COAST.
STILL LEFT CHANCE POPS ON SATURDAY. INITIAL SET UP ON SATURDAY HAS
MOISTURE MAX OVER THE CAROLINAS AND ANOTHER IN THE MIDWEST. RATHER
FRAGMENTED LEADING INTO THE MAIN EVENT.
COLDER AIR IN THE WAKE OF THE STORM WITH LINGERING SNOW SHOWERS
SUNDAY NIGHT INTO EARLY MONDAY.
&&
.AVIATION /10Z TUESDAY THROUGH SATURDAY/...
IFR TO MVFR CEILINGS REMAIN IN PLACE WITH THE LOW LEVEL
STRATUS...AND EXPECT IMPROVEMENT TO VFR GENERALLY AFTER 16Z TODAY.
BKW IS THE ONLY TERMINAL THAT MAY NOT COME ABOVE MVFR CONDITIONS
AND HAVE THE TAF PESSIMISTIC IN THIS CASE. THE RAP MODEL WAS
HANDLING THIS THE BEST.
LOW PRESSURE SYSTEM MOVES IN FROM THE SOUTHWEST...WITH THE
CEILINGS LOWERING AGAIN FROM THE TOP DOWN. EXPECTING IFR TO LIFR
CEILINGS TONIGHT IN PRECIPITATION WHICH WILL MAINLY BE RAIN ACROSS
THE AREA. PKB MAY BE DEALING WITH FREEZING RAIN OR SLEET AT TIMES
WITH THE ONSET OF THE PRECIPITATION...AND SHOULD CHANGE TO RAIN
LATER TONIGHT.
BRING THE VISIBILITIES DOWN TO IFR TONIGHT IN RAIN WHEN THE WINDS
DROP BELOW 5KTS.
SURFACE FLOW NORTHEAST TODAY AND TONIGHT AROUND 10KTS FOR THE
LOWLAND TERMINALS OF CRW...PKB...HTS...AND CKB. EKN AND BKW WILL
HAVE A SOUTHEAST FLOW AT THE SURFACE...WHERE BKW MAY GUST TO
20KTS.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z WEDNESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING OF STRATUS EROSION MAY VARY. TIMING OF IFR
WITH THE NEXT LOW PRESSURE SYSTEM COULD VARY...AS WELL AS
PRECIPITATION ONSET TIMING.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 11 12 13 14 15 16 17 18 19 20 21 22
EST 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
CRW CONSISTENCY L L L M M H H H H H H H
HTS CONSISTENCY M M L L H H H H H H H H
BKW CONSISTENCY M M H H L H H H H H H M
EKN CONSISTENCY M M M H H H H H H H H H
PKB CONSISTENCY M M H H H H H H H H H H
CKB CONSISTENCY L L H H H H H H H H H H
AFTER 12Z WEDNESDAY...
IFR POSSIBLE IN RAIN EARLY WEDNESDAY.
&&
.EQUIPMENT...
PKB ASOS HAS BEEN EXPERIENCING MALFUNCTIONS...RESULTING IN SOME
MISSING OR INCOMPLETE OBSERVATIONS. ELECTRONICS TECHNICIANS ARE
AWARE OF THE PROBLEM AND PARTS ARE BEING ACQUIRED.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FLOOD WATCH FROM THIS EVENING THROUGH WEDNESDAY MORNING FOR
WVZ005>011-013>020-024>040-046-047.
WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 10 AM EST
WEDNESDAY FOR WVZ009>011.
OH...FLOOD WATCH FROM THIS EVENING THROUGH WEDNESDAY MORNING FOR
OHZ067-075-076-083>087.
WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 10 AM EST
WEDNESDAY FOR OHZ067-075-076-083>085.
WINTER STORM WARNING FROM 5 PM THIS AFTERNOON TO 10 AM EST
WEDNESDAY FOR OHZ066.
KY...FLOOD WATCH FROM THIS EVENING THROUGH WEDNESDAY MORNING FOR
KYZ101>103-105.
VA...FLOOD WATCH FROM THIS EVENING THROUGH WEDNESDAY MORNING FOR
VAZ003-004.
&&
$$
SYNOPSIS...JMV/26
NEAR TERM...26
SHORT TERM...JMV
LONG TERM...KTB
AVIATION...26
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
454 AM EST TUE FEB 4 2014
.SYNOPSIS...
LOW PRESSURE SYSTEM WITH MULTIPLE PRECIPITATION TYPES LATE
TUESDAY. HIGH PRESSURE FOR THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
WE GET RID OF ONE MESSY SYSTEM 24 HOURS AGO...AND STILL HAVE TO DEAL
WITH ITS AFTER EFFECTS FOR THE FORECAST THIS MORNING. SNOWFALL FROM
THE SYSTEM YESTERDAY WILL HAVE DIRECT IMPACT ON THE WEATHER THROUGH
TONIGHT...IN COMBINATION WITH SURFACE NORTHEAST WINDS AND WARM AIR
ADVECTION OFF THE SURFACE. NEVER A GOOD COMBINATION.
FIRST...LOW LEVEL STRATUS REMAINS STUBBORNLY IN PLACE ACROSS MUCH OF
THE LOWLANDS OF WEST VIRGINIA...WITH A SHARP CUT OFF MAINLY JUST
NORTH OF THE OHIO RIVER. THIS HAS WREAKED HAVOC WITH THE OVERNIGHT
LOWS...AS AREAS IN THE CLEAR...SUCH AS ATHENS...BOTTOMED OUT UNDER
EFFICIENT RADIATIONAL COOLING CONDITIONS AND DROPPED INTO THE LOWER
TEENS...WHILE UNDER THE STRATUS...IT COULD NOT DROP OUT OF THE MID
TO UPPER 20S. CLOUDS ALSO ENVELOPED THE SOUTHERN MOUNTAINS...WITH
BKW IN THEM MOST OF THE NIGHT. RAP SUGGESTING THIS WILL BE NOT BE IN
A HURRY TO EXIT TODAY...AND AS HAS BEEN THE CASE SINCE LAST
EVENING...WILL LIKELY NEED TO PUSH THE ENDING TIME OF THE LOW LEVEL
MOISTURE FURTHER INTO THE DAY AS THE MODELS TRY TO FIGURE OUT WHAT
TO DO WITH THIS MOISTURE. IN TERMS OF SKY COVERAGE...THERE WILL
LITTLE CONSEQUENCE HOWEVER...AS WE ARE ALREADY SEEING HIGH LEVEL
MOISTURE STREAMING IN FROM THE SOUTHWEST...AND SHOULD BE OVERCAST
THROUGH THE PERIOD.
PRECIPITATION MOVES IN...AND HAVE KEPT THE TIMING AHEAD OF THE
MODELS AS IS COMMON WITH THESE LOWER MISSISSIPPI VALLEY ORIGINATING
STORMS. NOW COMES THE FUN OF DETERMINING THE PRECIPITATION TYPE.
MOS GUIDANCE FROM ANY MODEL WAS LARGELY USELESS FOR TEMPERATURES
TODAY...AND FELT THE OPERATIONAL GFS MODEL TEMPERATURES HAD THE BEST
HANDLE ON THE SITUATION OVER THE OHIO VALLEY. AS MENTIONED
EARLIER...SNOW PACK AND NORTHEASTERLY SURFACE WINDS WILL STIFF ARM
THE WARM ADVECTION ALOFT...MAKING IT DIFFICULT TO EVENTUALLY SCOUR
OUT THE COOL AIR. AS A RESULT...TEMPERATURES NEAR THE FREEZING MARK
CAN BE EXPECTED OVER A LARGE PORTION OF SOUTHEAST OHIO AND INTO THE
PLEASANTS AND TYLER COUNTY AREAS...AS WELL AS BACK INTO NORTHEAST
KENTUCKY. WILL ALSO SEE A LITTLE BIT OF THE WET BULB EFFECT ALOFT AT
THE START OF THE PRECIPITATION WHICH WILL NOT HELP MATTERS IN TERMS
OF GETTING TEMPERATURES ABOVE FREEZING. RUNNING THE WEATHER
PROCEDURE USING MODEL ALOFT TEMPERATURES AND THE SURFACE...BASICALLY
IN A TOP DOWN METHOD...PRODUCED MULTIPLE PRECIPITATION TYPES IN
SOUTHEAST OHIO AND JUST ACROSS THE RIVER OVER OUR NORTHERN ZONES.
THIS WAS THE REASON FOR THE WINTER WEATHER ADVISORY. PERRY COUNTY
WAS AN EASY CALL FOR THE UPGRADE TO A WARNING GIVEN THE POTENTIAL
FOR ACCUMULATING SLEET AND SNOW ON TOP OF THE FREEZING RAIN THREAT.
PER USUAL...WE ARE ON THE GRADIENT. IMAGINE THAT. SO IT GOES WITHOUT
SAYING THAT ANY MISSES REGARDING THE TEMPERATURES COULD HAVE HUGE
IMPACT ON THE RAIN/FREEZING RAIN/SLEET/SNOW LINES AND TIMINGS...AS
WAS THE STRUGGLE LAST NIGHT AS THE SUB FREEZING AIR TRIED MIGHTILY
TO SINK SOUTHWARD. HAVE HOISTED A WINTER WEATHER ADVISORY FOR THE
OTHER COUNTIES IN THE MIXED PRECIPITATION. WANTED TO GIVE THE DAY
SHIFT WHAT WILL LIKELY BE SOME MUCH NEEDED FLEXIBILITY FOR SOME LATE
CHANGES TO THESE HEADLINES AS FAR AS EXPANSIONS OR UPGRADES DUE TO A
SOMEWHAT MEDIOCRE CONFIDENCE IN THE FORECAST THIS MORNING.
NOW IT IS IMPORTANT TO REMEMBER THE FLOOD WATCH THAT IS IN PLACE.
THERE IS 1 TO 2 INCHES OF WATER CWA WIDE THAT EITHER FELL AS RAIN OR
IS STORED IN SNOW...DEPENDING ON THE LOCATION. WITH A SATURATED
GROUND THAT MAY BE PARTIALLY FROZEN IN AREAS...RUNOFF FROM THE RAIN
THAT WILL FALL OVER THE REST OF THE AREA WILL TEST THE AREA
STREAMS...CREEKS...AND RIVERS AS ANOTHER 0.75 TO 1.5 INCHES OF RAIN
OR LIQUID EQUIVALENT ARE POSSIBLE. THE FACT THAT THIS RAIN WILL FALL
BASIN WIDE IS THE OTHER TROUBLING PART OF THIS EQUATION. IN
SOUTHEAST OHIO...THERE MAY BE A TOUCH OF A CONFLICT WITH A WINTER
STORM WARNING OR WINTER WEATHER ADVISORY WHERE SLEET AND SNOW ARE A
POSSIBILITY...BUT FEEL THIS FLOOD WATCH IS STILL WELL SERVED IN
THESE PARTS.
ON THE SYNOPTIC SCALE...AFTER THE LOW PRESSURE PASSES TO THE
NORTHEAST TONIGHT...A SHARP DRY SLOT IS EXPECTED TO FOLLOW...SO
THERE MAY ACTUALLY BE SOME BREAKS IN THE CLOUDS IN THE FAR
NORTHWESTERN ZONES OF SOUTHEAST OHIO BY 12Z WEDNESDAY.
NOT DONE YET.
SOUTHEAST UPSLOPE FLOW MAKES LIFE DIFFICULT ON THE OTHER SIDE OF THE
CWA. STILL WATCHING THE WARM AIR ADVECTION...BUT 925MB WINDS AND
TEMPERATURES SHOW COLD AIR DAMMING THAT WILL BE TOUGH TO ERODE.
MOIST UPSLOPE FLOW PROMISES TO KEEP THE TEMPERATURES FROM
CLIMBING...AND WITH THE WARM PUNCH ALOFT IN RAIN...FREEZING RAIN IS
A DISTINCT POSSIBILITY LATE THIS EVENING AND TONIGHT FOR THE
GREENBRIER AND CHEAT RIVER VALLEY. THE GFS TEMPERATURES WERE NOT AS
BULLISH ON THE COLD BIAS THAT APPEARS TO BE THE BETTER SOLUTION AS
MENTIONED ABOVE...AND THUS...FEAR THAT THE OUTPUT FROM USING THE
WEATHER PROCEDURE WAS MODEST FREEZING RAIN RELEGATED TO THE FAR
EASTERN FRINGES OF RANDOLPH AND POCAHONTAS COUNTIES. NO HEADLINE YET
HERE. WILL LOOK OVER THIS ONE MORE TIME BEFORE LEAVING FOR THE
NIGHT...BUT HOPING THE NEXT MODEL RUN IS MORE HELPFUL IN THE
TEMPERATURES OUT THAT WAY THAN IT WAS FOR THIS ISSUANCE.
THINK THAT IS IT. MY BRAIN IS SHOT.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
STORM SYSTEM IS PULLING OUT AT THE BEGINNING OF THE PERIOD. EXCEPT
FOR THE NAM...OTHER MODELS ARE IN GOOD AGREEMENT ON A FASTER TIMING
OF THE FRONT ACROSS THE AREA WEDNESDAY. FRONT AT 12Z WEDNESDAY
EXPECTED TO BE NEAR THE I79 CORRIDOR...WITH CAT POPS IN RAIN
PRECEDING THE FRONT. FRONT WITH THE ORGANIZED RAIN EXITS MOUNTAINS
BY 18Z. BEHIND THE FRONT...MODELS HAVE A TYPICAL DRY SLOT FOR THIS
UPPER PATTERN...THIS BEING A STRONG WEST TO SOUTHWEST UPPER FLOW
WITH SOUTHWEST WINDS BEHIND THE FRONT. THUS...WE HAVE A SLOT OF NO
POPS FOR A TIME BEHIND THE INITIAL FRONT BEFORE THE REAL COLD FRONT
SWEEPS SOUTHEAST DURING WEDNESDAY. EVEN WITH SOME LOW LEVEL MOISTURE
AND GOOD COLD ADVECTION IN WEST TO NORTHWEST FLOW BEHIND THIS
REINFORCING SHOT OF COLD AIR...WHERE TEMPERATURES WILL BE SLOWLY
FALLING DURING THE DAY...THE PATTERN IS NOT REALLY CONDUCIVE FOR
POST FRONTAL AND UPSLOPE RAIN SHOWERS THAT WOULD CHANGE TO SNOW
SHOWERS. LOW LEVELS WILL HAVE A DISTINCTIVE ANTICYCLONIC CURVATURE
TO THE FLOW...AND MOISTURE WILL BE ON THE SHALLOW SIDE. THUS...WE
WILL CONFINE ANY SHOWERS TO THE NORTH AND NORTHEAST PORTIONS OF THE
AREA. THESE WILL END WEDNESDAY NIGHT AS SNOW SHOWERS...BUT LITTLE
ACCUMULATIONS IF ANY. TEMPERATURES WILL FALL BACK THRU THE 30S
WEDNESDAY AFTERNOON AND DOWN THROUGH THE 20S WEDNESDAY NIGHT UNDER
SOME DECENT COLD ADVECTION. HIGH PRESSURE BUILDS IN FOR THURSDAY
WITH DECREASING CLOUDS...BUT MUCH COLDER WITH HIGH TEMPS MAINLY IN THE
20S. MODERATING TEMPS FRIDAY UNDER SUNSHINE AS HIGH PRESSURE SHIFTS
EAST.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
HARD TO FIGURE THE AMOUNT OF CLOUD COVER FOR THURSDAY NIGHT INTO
FRIDAY...WITH SOME WEAK WARM AIR ADVECTION AT 850 MB. ONLY POPS
WERE SOME TOKEN 20 PERCENTS FOR THE MOST PART. SO MAINLY DRY WEATHER
FIGURED THROUGH FRIDAY NIGHT.
MAIN BULK OF PCPN FORECAST TO ARRIVE LATE SATURDAY NIGHT INTO
SUNDAY...WILL KEEP LIKELY POPS FOR RAIN OR SNOW. SEEMS THE HIGHER
PCPN TOTALS WITH THIS STORM WILL BE TO OUR EAST...TOWARD THE COAST.
STILL LEFT CHANCE POPS ON SATURDAY. INITIAL SET UP ON SATURDAY HAS
MOISTURE MAX OVER THE CAROLINAS AND ANOTHER IN THE MIDWEST. RATHER
FRAGMENTED LEADING INTO THE MAIN EVENT.
COLDER AIR IN THE WAKE OF THE STORM WITH LINGERING SNOW SHOWERS
SUNDAY NIGHT INTO EARLY MONDAY.
&&
.AVIATION /10Z TUESDAY THROUGH SATURDAY/...
CONTINUING WITH THE RAP MODEL WHICH HOLDS THE IFR MOISTURE THROUGH
12Z FOR THE MOST PART...DEPENDING ON TERMINAL. PKB WILL LIKELY BE
THE FIRST TO ESCAPE THE LOW LEVEL MOISTURE.
BRIEF VFR POSSIBLE GENERALLY AFTER 15Z AHEAD OF THE UPPER LEVEL
AND MID LEVEL MOISTURE WITH THE NEXT LOW PRESSURE SYSTEM. RAIN
SETTLES IN SOUTHWEST TO NORTHEAST INTO THE LATTER HALF OF THE TAF
PERIOD...AND WILL EXPECT CONDITIONS TO DETERIORATE
RAPIDLY...CEILINGS FIRST AND THEN VISIBILITIES AS THE LOWEST
LEVELS SATURATE.
BKW TO STAY IN THE LIFR CONDITIONS THROUGH THE REMAINDER OF THE
OVERNIGHT.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z WEDNESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING OF CLEARING COULD VARY. TIMING OF IFR
WITH THE NEXT LOW PRESSURE SYSTEM COULD VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE TUE 02/04/14
UTC 1HRLY 08 09 10 11 12 13 14 15 16 17 18 19
EST 1HRLY 03 04 05 06 07 08 09 10 11 12 13 14
CRW CONSISTENCY H H H H L L H H H H H H
HTS CONSISTENCY L L L L M H H H H H H H
BKW CONSISTENCY L H H H H L L L H H H H
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY L L L L L H H H H H H H
CKB CONSISTENCY M M M L L H H H H H H H
AFTER 12Z WEDNESDAY...
IFR POSSIBLE IN RAIN LATE TUESDAY NIGHT THROUGH EARLY WEDNESDAY.
&&
.EQUIPMENT...
PKB ASOS HAS BEEN EXPERIENCING MALFUNCTIONS...RESULTING IN SOME
MISSING OR INCOMPLETE OBSERVATIONS. ELECTRONICS TECHNICIANS ARE
AWARE OF THE PROBLEM AND PARTS ARE BEING ACQUIRED.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FLOOD WATCH FROM THIS EVENING THROUGH WEDNESDAY MORNING FOR
WVZ005>011-013>020-024>040-046-047.
WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 10 AM EST
WEDNESDAY FOR WVZ009>011.
OH...FLOOD WATCH FROM THIS EVENING THROUGH WEDNESDAY MORNING FOR
OHZ067-075-076-083>087.
WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 10 AM EST
WEDNESDAY FOR OHZ067-075-076-083>085.
WINTER STORM WARNING FROM 5 PM THIS AFTERNOON TO 10 AM EST
WEDNESDAY FOR OHZ066.
KY...FLOOD WATCH FROM THIS EVENING THROUGH WEDNESDAY MORNING FOR
KYZ101>103-105.
VA...FLOOD WATCH FROM THIS EVENING THROUGH WEDNESDAY MORNING FOR
VAZ003-004.
&&
$$
SYNOPSIS...JMV/26
NEAR TERM...26
SHORT TERM...JMV
LONG TERM...KTB
AVIATION...26
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1246 AM EST TUE FEB 4 2014
.SYNOPSIS...
HIGH PRESSURE CROSSES NORTH TONIGHT. NEXT LOW PRESSURE SYSTEM
LATE TUESDAY. HIGH PRESSURE FOR THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 11 AM THIS MORNING/...
UPDATE...
KEPT THE LOW LEVEL STRATUS GOING THROUGH THE MORNING. AFTER THIS
DECK LIFTS...OVERCAST REMAINS WITH MID AND UPPER LEVEL MOISTURE
AHEAD OF THE NEXT SYSTEM.
PREVIOUS DISCUSSION...
STRATUS DECK IS BEING OVERLY PERSISTENT THIS EVENING. WHEN FLOW
SWITCHES AROUND TO THE SOUTHEAST LATER TONIGHT...THINK THAT
DOWNSLOPING WILL ERODE THE DECK WEST OF THE MOUNTAINS. WILL SLOW
DOWN CLEARING ACCORDINGLY.
&&
.SHORT TERM /11 AM THIS MORNING THROUGH THURSDAY/...
STILL SOME MINOR DIFFERENCE REGARDING THE SYNOPTIC SOLUTION FOR THE
BIG WX SYSTEM MIDWEEK. SURFACE LOW LOOKS TO TRACK OVER THE
AREA...MOST LIKELY CLOSE TO THE OH RIVER WITH SECONDARY DEVELOPMENT
ALONG THE MID ATLANTIC COAST ON WEDNESDAY. THIS TRACK PUTS PORTIONS
OF SE OH...IE PERRY/MORGAN INTO PRECIP TYPE CONUNDRUMS. THROWING OUT
THE NAM SOLUTION AND EVEN DISCARDING THE S TRACK OF GFS...STILL
LEAVES A PERIOD OF HEAVY SNOW TUESDAY NIGHT FOR PERRY COUNTY VIA THE
NEW ECMWF RUN.
AFTER SOME COORDINATION WITH SURROUNDING OFFICES...ELECTED TO
HOIST A WINTER STORM WATCH FOR PERRY FOR 3 TO 5 INCHES POSSIBLY
MIXING WITH OR CHANGING TO SLEET AT TIMES OVERNIGHT. PORTIONS OF
MORGAN...N ATHENS AND VINTON MAY ALSO GET IN ON THE ACCUMULATING
SNOWS BEFORE SWITCHING TO RA WHICH MAY BE ADVISORY WORTHY IN
SUBSEQUENT SHIFTS. ELSEWHERE...THERMAL PROFILES STILL INDICATE
MUCH OF THE PRECIP FALLS AS RAIN ACROSS THE AREA. EXCEPTION IS THE
E SLOPES PARTICULARLY ACROSS THE GREENBRIER VALLEY IN POCAHONTAS
COUNTY. SOUNDINGS INDICATE A GOOD CAD SIGNATURE FOR TUESDAY NIGHT
WITH A FREEZING RAIN SCENARIO IN THE CARDS WITH PERHAPS A LITTLE
SLEET OR SNOW AT ONSET WITH WARM FRONT CROSSING. COULD SEE AN
ADVISORY EVENTUALLY BEING ISSUED FOR THIS. OTHERWISE THE WARM LOW
LEVEL SURGE THE RULE FOR MOST IN WV WITH THOSE AFOREMENTIONED
AREAS IN SE OH CLOSE TO WINTRY TYPE PRECIP ON THE COLD SIDE. WILL
INSERT A MENTION IN HWO FOR POCAHONTAS COUNTY AND OTHER SE OH
COUNTIES MENTIONED ABOVE FOR POSSIBLE ADVISORIES.
RAINFALL AMOUNTS STILL LOOK TROUBLING ESPECIALLY AFTER
CONSIDERING WHAT JUST HAPPENED. HPC HAS A SLIGHT RISK FOR
EXCESSIVE RAIN FOR MUCH OF THE AREA. THERE IS A FEELING THAT
STRONG DOWNSLOPING MAY HELP PORTIONS OF THE LOWLANDS AND SW VA A
BIT AS FAR AS HIGH QPF AMOUNTS SHOULD THE LOW TRACK UP THE OHIO
RIVER. A FLOOD WATCH HAS BEEN ISSUED AREAWIDE EXCEPT FOR PERRY FOR
RAIN AMOUNTS OF 1 TO 1.5 INCHES ALONG WITH AN ICE JAM WORRY ON THE
SMALLER RIVERS. A CHANGE TO SNOW IS EXPECTED AS THE SYSTEM PULLS
OUT EARLY WEDNESDAY WITH SOME COATINGS POSSIBLE FOR PORTIONS OF
THE AREA.
ALSO OF NOTE IS STOUT LLJ DEPICTED ON THE MODELS TUESDAY
NIGHT BUT THEY ALSO SHOW ENOUGH OF AN INVERSION TO KEEP MOST IF
OFF THE DECK. STILL ALLOWED FOR SOME 20 KT GUSTS...A BIT HIGHER IN
SE WV.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
HARD TO FIGURE THE AMOUNT OF CLOUD COVER FOR THURSDAY NIGHT INTO
FRIDAY...WITH SOME WEAK WARM AIR ADVECTION AT 850 MB. ONLY POPS
WERE SOME TOKEN 20 PERCENTS FOR THE MOST PART. SO MAINLY DRY WEATHER
FIGURED THROUGH FRIDAY NIGHT.
MAIN BULK OF PCPN FORECAST TO ARRIVE LATE SATURDAY NIGHT INTO
SUNDAY...WILL KEEP LIKELY POPS FOR RAIN OR SNOW. SEEMS THE HIGHER
PCPN TOTALS WITH THIS STORM WILL BE TO OUR EAST...TOWARD THE COAST.
STILL LEFT CHANCE POPS ON SATURDAY. INITIAL SET UP ON SATURDAY HAS
MOISTURE MAX OVER THE CAROLINAS AND ANOTHER IN THE MIDWEST. RATHER
FRAGMENTED LEADING INTO THE MAIN EVENT.
COLDER AIR IN THE WAKE OF THE STORM WITH LINGERING SNOW SHOWERS
SUNDAY NIGHT INTO EARLY MONDAY.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
CONTINUING WITH THE RAP MODEL WHICH HOLDS THE IFR MOISTURE THROUGH
12Z FOR THE MOST PART...DEPENDING ON TERMINAL. PKB WILL LIKELY BE
THE FIRST TO ESCAPE THE LOW LEVEL MOISTURE.
BRIEF VFR POSSIBLE GENERALLY AFTER 15Z AHEAD OF THE UPPER LEVEL
AND MID LEVEL MOISTURE WITH THE NEXT LOW PRESSURE SYSTEM. RAIN
SETTLES IN SOUTHWEST TO NORTHEAST INTO THE LATTER HALF OF THE TAF
PERIOD...AND WILL EXPECT CONDITIONS TO DETERIORATE
RAPIDLY...CEILINGS FIRST AND THEN VISIBILITIES AS THE LOWEST
LEVELS SATURATE.
BKW TO STAY IN THE LIFR CONDITIONS THROUGH THE REMAINDER OF THE
OVERNIGHT.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z WEDNESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING OF CLEARING COULD VARY. TIMING OF IFR
WITH THE NEXT LOW PRESSURE SYSTEM COULD VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE TUE 02/04/14
UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
EST 1HRLY 01 02 03 04 05 06 07 08 09 10 11 12
CRW CONSISTENCY H H M H H H M M H H H H
HTS CONSISTENCY L L L L L L L H H H H H
BKW CONSISTENCY L L L H H H H L L L H H
EKN CONSISTENCY H L L L L M H H H H H H
PKB CONSISTENCY L L L L L L L H H H H H
CKB CONSISTENCY L L L L L L H H H H H H
AFTER 06Z WEDNESDAY...
IFR POSSIBLE IN RAIN LATE TUESDAY NIGHT THROUGH EARLY WEDNESDAY.
&&
.EQUIPMENT...
PKB ASOS HAS BEEN EXPERIENCING MALFUNCTIONS...RESULTING IN SOME
MISSING OR INCOMPLETE OBSERVATIONS. ELECTRONICS TECHNICIANS ARE
AWARE OF THE PROBLEM AND PARTS ARE BEING ACQUIRED.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FLOOD WATCH FROM THIS EVENING THROUGH WEDNESDAY MORNING FOR
WVZ005>011-013>020-024>040-046-047.
OH...FLOOD WATCH FROM THIS EVENING THROUGH WEDNESDAY MORNING FOR
OHZ067-075-076-083>087.
WINTER STORM WATCH FROM THIS EVENING THROUGH WEDNESDAY MORNING
FOR OHZ066.
KY...FLOOD WATCH FROM THIS EVENING THROUGH WEDNESDAY MORNING FOR
KYZ101>103-105.
VA...FLOOD WATCH FROM THIS EVENING THROUGH WEDNESDAY MORNING FOR
VAZ003-004.
&&
$$
SYNOPSIS...KTB/RPY/30
NEAR TERM...RPY/26
SHORT TERM...30
LONG TERM...KTB
AVIATION...26
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
945 PM CST WED FEB 5 2014
.UPDATE...
CLOUDS AND MOISTURE WILL GRADUALLY INCREASE OVERNIGHT AS A
PRONOUNCED SHORTWAVE OVER NORTHERN MEXICO MOVES EAST INTO WEST-
CENTRAL TEXAS. MOISTURE LEVELS WILL REMAIN LIMITED WITH THIS
SYSTEM...BUT SUFFICIENT FOR LIGHT PRECIPITATION TO DEVELOP OVER
WESTERN COUNTIES OF NORTH TEXAS EARLY THURSDAY MORNING...THEN
SWEEP NORTHEAST ACROSS THE CENTRAL AND NORTHEASTERN COUNTIES LATE
MORNING THROUGH EARLY AFTERNOON. SUB-FREEZING TEMPERATURES AT ALL
ALTITUDES INDICATES THAT PRECIPITATION WILL FALL AS SNOW. THE MOST
RECENT MODEL OUTPUT FROM THIS EVENING REMAINS FAIRLY CONSISTENT
WITH EARLIER RUNS...INDICATING 1-2 INCHES OVER THE WESTERN-MOST
LOCALES...TAPERING OFF TO AROUND A QUARTER OR HALF AN INCH IN THE
DALLAS-FORT WORTH METROPLEX...TO A DUSTING FARTHER EAST. A WINTER
WEATHER ADVISORY WILL REMAIN IN EFFECT FROM 3 AM UNTIL 2 PM
THURSDAY FOR AREAS GENERALLY WEST OF AN EASTLAND TO JACKSBORO TO
BOWIE LINE. PRECIPITATION WILL COME TO AN END THURSDAY AFTERNOON AS
THE SHORTWAVE ACCELERATES EASTWARD INTO THE MISSISSIPPI VALLEY. AT
THIS TIME...IT APPEARS THAT MEASURABLE SNOWFALL WILL BE LIMITED TO
AREAS GENERALLY ALONG AND NORTHWEST OF A LINE FROM PARIS TO
COMANCHE...WHILE AREAS FARTHER SOUTH AND EAST MAY BE TOO FAR REMOVED
FROM THE UPPER LEVEL FEATURE TO RECEIVE MEASURABLE PRECIPITATION.
EITHER WAY...BITTER COLD CONDITIONS WILL BE EXPERIENCED AREA-WIDE
THROUGH TOMORROW AS TEMPERATURES PLUMMET INTO THE TEENS. A WIND CHILL
ADVISORY WILL REMAIN IN PLACE OVERNIGHT FOR AREAS ALONG AND NORTH
OF A LINE FROM CISCO TO WEATHERFORD TO MCKINNEY TO BONHAM. WE
WILL KEEP AN EYE ON PRECIPITATION TRENDS AS ACTIVITY UNFOLDS LATER
TONIGHT...AND ADJUST THE AREAS OF THE WINTER WEATHER ADVISORY IF
NEEDED. AT THIS TIME...THE FORECAST REMAINS IN GREAT SHAPE WITH NO
SIGNIFICANT UPDATES NEEDED.
30
&&
.AVIATION...
/00Z TAFS/
CONCERNS...MVFR CIGS LATE TONIGHT AND THURSDAY MORNING IN THE
METROPLEX. CHANCE FOR LIGHT SNOW IN THE METROPLEX THURSDAY MORNING.
THE CHALLENGES...IMPACTS...AND CONCERNS FOR THE NEXT 24-30 HOURS
FOCUS MORE ON THE METROPLEX AIRPORTS WITH KACT REMAINING IN VFR
STATUS. SOME OF THE MODELS ARE INDICATING A CHANCE FOR MVFR CIGS
AROUND 2500 FEET AT KACT OVERNIGHT...BUT THE MODELS ARE SUFFERING
WITH RESOLVING THE CURRENT CLOUD CONDITIONS AND DO NOT HAVE ENOUGH
CONFIDENCE AT THIS TIME TO BRING MVFR CIGS INTO WACO WITH THIS TAF
PACKAGE.
FOR THE METROPLEX...BEST GUESS ON MVFR CIGS AROUND 2500 FEET
ARRIVING IS 06Z. AS MENTIONED ABOVE...THE MODELS ARE SUFFERING
WITH CLOUD TRENDS TODAY AND GOING INTO THE EVENING HOURS...AND WILL
BE MONITORING FOR ANY NECESSARY AMENDMENTS. A POSSIBLE SCENARIO IS
THE MVFR CIGS ACROSS OKLAHOMA SPREAD SOUTH AND ARRIVE IN THE
METROPLEX BEFORE 06Z. SOME OF THE MODELS ALSO INDICATE THE
MVFR CIGS OVERNIGHT WILL MAINLY AFFECT THE WESTERN HALF OF THE
METROPLEX...INCLUDING KAFW AND KFTW.
THERE IS STILL A CHANCE FOR LIGHT SNOW MOVING IN FROM THE WEST
THURSDAY MORNING...REACHING THE METROPLEX BETWEEN 14-15Z. SEVERAL
MODELS KEEP THE SNOW WEST OF THE METROPLEX EXCEPT FOR POSSIBLY
KAFW...SO DID NOT FEEL A NEED TO CHANGE THE CURRENT TAF TIMING AND
IMPACTS DUE TO LIGHT SNOW. CONDITIONS ARE EXPECTED TO IMPROVE AROUND
MIDDAY WITH WIND SPEEDS FINALLY DECREASING TO LESS THAN 10 KTS
DURING THE AFTERNOON HOURS.
82/JLD
&&
.PREV DISCUSSION... /ISSUED 346 PM CST WED FEB 5 2014/
VERY PROGRESSIVE UPPER PATTERN WILL KEEP NORTH TEXAS COLD WITH
SEVERAL CHANCES FOR AT LEAST LIGHT PRECIPITATION OVER THE UPCOMING
WEEK. WITH TEMPERATURES NOT EXPECTED TO MAKE IT ABOVE FREEZING
UNTIL SOMETIME FRIDAY...WINTRY PRECIPITATION REMAINS IN THE
FORECAST.
WATER VAPOR IMAGERY SHOWS STRONG SHORTWAVE NOW MAKING ITS WAY
ACROSS NORTHWEST MEXICO. RUC ANALYSIS OF THE DYNAMIC TROPOPAUSE
HAS CONSISTENTLY SUGGESTED THAT THIS FEATURE IS STRONGER THAN MOST
OF THE OTHER OPERATIONAL MODEL GUIDANCE IS INDICATING. THIS IS SUPPORTED
BY THE IMAGERY ITSELF WHICH SHOWS A COMPACT POTENT VORTEX DIGGING
ACROSS THE MEXICAN STATE OF SONORA. AS IT MOVES INTO THE BIG BEND
REGION LATER TONIGHT...SATURATION WILL TAKE PLACE FROM BOTH THE
TOP DOWN AND FROM LOW LEVEL WARM MOIST ADVECTION AS 850MB FLOW
VEERS IN RESPONSE TO APPROACHING SHORTWAVE. THE THERMAL PROFILE
ACROSS NORTH TEXAS WILL BE SUFFICIENTLY COLD TO SUPPORT ALL SNOW
SO PRECIP TYPE IS REALLY NOT IN QUESTION THIS TIME AROUND.
CROSS SECTION ANALYSIS FROM SOUTHWEST OKLAHOMA INTO NORTH CENTRAL
TEXAS INDICATES A DEEP SATURATED LAYER BY THURSDAY MORNING WITH
CONDITIONAL SYMMETRIC INSTABILITY PRESENT. AS FORCING INCREASES
LATE TONIGHT...AREAS OF SNOW ARE EXPECTED TO DEVELOP MAINLY ACROSS
THE WESTERN COUNTIES. SOME BANDING OF THE PRECIPITATION IS
POSSIBLE GIVEN THE PRESENCE OF INSTABILITY MENTIONED EARLIER AND
THIS HAS EVEN BEEN INDICATED IN THE LAST COUPLE OF RUNS OF THE 3KM
TTU WRF. WHILE QPF AMOUNTS ARE GENERALLY LIGHT ACROSS THE AREA...THE
COLD TEMPERATURES SHOULD SUPPORT SNOWFALL RATIOS OF GREATER THAN
10 TO 1. THIS ISNT TYPICAL FOR NORTH TEXAS AS WE USUALLY WIND UP
DEALING WITH HEAVY WET SNOW. BASED ON THE LATEST DATA...WE THINK 1
TO 2 INCHES OF SNOW WILL BE POSSIBLE ACROSS THE WESTERN COUNTIES
WITH LIGHTER AMOUNTS FARTHER EAST INTO THE METROPLEX. ALL OF THE
ACTIVITY SHOULD END QUICKLY BY MIDDAY OR SHORTLY THEREAFTER. A
WINTER WEATHER ADVISORY HAS BEEN ISSUED FOR THE FAR WESTERN
COUNTIES WHERE GREATEST ACCUMULATIONS ARE EXPECTED. IN
ADDITION...THE WIND CHILL ADVISORY WILL REMAIN UNCHANGED AS TEMPS
ARE EXPECTED TO FALL INTO THE LOW TO MID TEENS WITH GUSTY NORTH WINDS.
AS SOON AS THIS SYSTEM DEPARTS...ANOTHER IS QUICKLY ON ITS HEELS
FOR FRIDAY AND THIS COULD ACTUALLY BE THE DAY OF MORE SIGNIFICANT
WINTER WEATHER IMPACTS. COLD TEMPERATURES WILL REMAIN ENTRENCHED
ACROSS THE REGION WITH MOST AREAS IN THE LOW 20S EARLY FRIDAY
MORNING. SURFACE FLOW WILL WEAKEN AND VEER TO THE EAST DURING THE
DAY FRIDAY...BUT SOUTHERLY 850MB FLOW WILL BE ESTABLISHED BY THIS
TIME. LOW LEVEL MOISTURE AND WARM ADVECTION WILL BE SUFFICIENT FOR
LIGHT PRECIPITATION TO DEVELOP DURING THE DAY FRIDAY. ANALYSIS OF
FORECAST SOUNDINGS INDICATE A COUPLE OF SCENARIOS POSSIBLY PLAYING OUT.
THE LEAST FAVORABLE AT THIS TIME WOULD BE FOR A QUICK RETURN OF
MOISTURE AND WIDESPREAD SNOW TO DEVELOP DURING THE DAY. THIS SEEMS
UNLIKELY GIVEN THE LACK OF MORE SIGNIFICANT MOISTURE ALOFT...AND
MORE IMPORTANTLY LACK OF MOISTURE IN THE SNOW DENDRITIC GROWTH
ZONE. WHILE THERE WILL BE SUFFICIENT MOISTURE DOWN LOW...IT IS LIKELY
TO BE IN THE FORM OF SUPER COOLED WATER DROPLETS...WHICH LEADS TO
THE MORE LIKELY SCENARIO OF WIDESPREAD VERY LIGHT FREEZING RAIN OR
FREEZING DRIZZLE. WITH TEMPERATURES IN THE LOW TO MID 20S AND
GROUND TEMPERATURES SUFFICIENTLY COLD...ICE WOULD LIKELY RAPIDLY
DEVELOP. FOR NOW...CONFIDENCE IS LOW IN ANY PARTICULAR SOLUTION
BUT WILL HAVE 20 POPS FOR LIGHT FREEZING RAIN/DRIZZLE ON FRIDAY.
BEYOND FRIDAY...MODELS DIFFER WITH FRONTAL TIMING ON MONDAY WITH
THE ECMWF BRINGING A FRONT THROUGH AND GFS HOLDING OFF UNTIL
TUESDAY. THIS FORECAST PACKAGE WILL COMPROMISE BETWEEN THE TWO AND
SHOW INCREASING RAIN CHANCES FOR MON/TUE TIMEFRAME.
DUNN
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 17 27 20 35 28 / 10 50 5 20 10
WACO, TX 20 34 22 38 29 / 10 20 5 20 10
PARIS, TX 19 27 22 37 27 / 10 50 5 20 10
DENTON, TX 17 25 17 35 26 / 10 70 5 20 10
MCKINNEY, TX 16 27 18 34 26 / 10 50 5 20 10
DALLAS, TX 18 29 21 36 28 / 10 50 5 20 10
TERRELL, TX 20 30 21 37 28 / 10 30 5 20 10
CORSICANA, TX 21 35 25 38 30 / 10 20 5 20 10
TEMPLE, TX 22 35 22 39 31 / 10 10 5 20 10
MINERAL WELLS, TX 16 26 18 35 25 / 20 70 5 20 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 3 AM TO 2 PM CST THURSDAY FOR
TXZ091-100-101-115-116-129.
WIND CHILL ADVISORY FROM 3 AM TO NOON CST THURSDAY FOR
TXZ091>094-100>104-115>117-129-130.
&&
$$
82/30
AREA FORECAST DISCUSSION
NWS AMARILLO TX
157 PM CST TUE FEB 4 2014
.UPDATE...
EXTENDED THE WINTER WEATHER ADVISORY FOR BEAVER COUNTY UNTIL 3 PM
WHILE ALLOWING THE REST OF THE COUNTIES EXPIRE. AN ADDITIONAL ONE
HALF INCH TO ONE INCH WILL BE POSSIBLE ACROSS THE EASTERN AND
NORTHERN PORTIONS OF BEAVER COUNTY BEFORE THE SNOW MOVES OUT OF THE
COUNTY.
&&
.PREV DISCUSSION... /ISSUED 1206 PM CST TUE FEB 4 2014/
UPDATE...
LET THE WINTER WEATHER ADVISORY EXPIRE FOR THE MAJORITY OF THE TEXAS
AND OKLAHOMA PANHANDLE AS HEAVY SNOW SHOWERS HAVE MOVED OUT OF THE
AREA. THE EASTERN AND CENTRAL OKLAHOMA PANHANDLE AND NORTHEASTERN
TEXAS PANHANDLE REMAINS IN THE ADVISORY THROUGH 2 PM AS SNOW IS
CONTINUING TO OCCUR. AN ADDITIONAL ONE INCH MAY BE POSSIBLE ACROSS
PARTS OF BEAVER AND LIPSCOMB COUNTIES WITH LESS AMOUNTS EXPECTED
ACROSS THE REST OF THE ADVISORY AREA. LIGHT SNOW WILL BE POSSIBLE
THROUGH THE LATE EVENING HOURS WITH ADDITIONAL ACCUMULATIONS EXPECTED
TO BE LESS THAN A QUARTER INCH.
PREV DISCUSSION... /ISSUED 1129 AM CST TUE FEB 4 2014/
AVIATION...
NORTH WINDS IN THE 15 TO 20 KNOT RANGE WILL PREVAIL THROUGH THIS
FORECAST. SOME LIGHT SNOW WILL STILL BE POSSIBLE AT THE GUY AND AMA
TAF SITES THIS AFTERNOON...BUT FOR THE MOST PART...THE ORGANIZED
SNOW IS MOVING AWAY. IFR CONDITIONS WILL CONTINUE THROUGH MOST OF THE
NIGHT AT DHT AND GUY WITH CONDITIONS IMPROVING INTO THE MVFR RANGE
WEDNESDAY MORNING. IFR CONDITIONS AT AMA WILL GRADUALLY IMPROVE THIS
EVENING INTO THE MVFR RANGE.
PREV DISCUSSION... /ISSUED 551 AM CST TUE FEB 4 2014/
AVIATION...
FOR THE 12Z TAFS...LIGHT TO OCCASIONALLY MODERATE SNOW AND ASSOCIATED
LOW CIGS AND VSBYS WILL CONTINUE AT ALL TERMINAL SITES THIS
MORNING...WITH CONDITIONS GRADUALLY IMPROVING FROM SW TO NE ACROSS
THE AREA AS THE DAY WEARS ON. THIS IS REFLECTED IN THE TAFS. CIGS MAY
RISE INTO THE MVFR CATEGORY DURG THE COURSE OF TODAY BEFORE POSSIBLY
FALLING TO IFR AFTER SUNSET THIS EVENING AS HINTED AT IN LATEST MODEL
GUIDANCE.
ANDRADE
PREV DISCUSSION... /ISSUED 515 AM CST TUE FEB 4 2014/
SHORT TERM...SNOWFALL POTENTIAL AND COLD TEMPS ARE THE MAIN WEATHER
CONCERNS TODAY AND WEDNESDAY.
LIGHT TO MODERATE SNOW HAS INCREASED ACROSS THE TX/OK PANHANDLES
EARLY THIS MORNING AHEAD OF AN UPPER TROUGH OVER WEST TX. CURRENT
WATER VAPOR SATELLITE IMAGERY SHOWS ENHANCED CLOUD TOPS OVER NORTHERN
OK AND SOUTHERN KS...INDICATING WHERE THE HEAVIER BANDS OF SNOW ARE
LOCATED. HOWEVER FURTHER WEST...UPPER LIFT ASSOCIATED WITH THIS
SYSTEM AND ABUNDANT LOW-LEVEL MOISTURE OVER THE AREA WILL CONTINUE
TO SUPPORT SNOW THROUGHOUT MUCH OF THE DAY. STILL LOOKS LIKE THE
EASTERN OK PANHANDLE AND THE NORTHEASTERN TX PANHANDLE WILL BE THE
FAVORED AREAS FOR THE HEAVIER SNOWFALL ALTHOUGH THE RUC HAS THE
HIGHER SNOW TOTALS OVER SOUTHERN KS WHILE THE CURRENT HPC WINTER WX
DESK HAS LOWERED SNOWFALL TOTALS ACROSS THE AREA. GIVEN THIS AND THE
LATER ONSET OF SNOW...HAVE TRIMMED SNOWFALL TOTALS A TAD ALTHOUGH
STILL LOOKING TOTAL STORM ACCUMULATIONS OF 1 TO 5 INCHES. WILL
CONTINUE WITH THE WINTER WX ADVISORY FOR ALL OF THE CWA BUT WILL HOLD
OFF ON ISSUING A WINTER STORM WARNING FOR BEAVER COUNTY AS CONFIDENCE
OF THIS AREA RECEIVING ACCUMULATING SNOWS OF 6+ INCHES IS NOT HIGH.
SNOW WILL GRADUALLY END BY THIS EVENING ALTHOUGH THE WESTERN OK AND
NORTHWESTERN TX PANHANDLE CAN CONTINUE TO SEE LIGHT SNOW THIS
EVENING IN ASSOCIATION TO A STRONG COLD FRONT THAT WILL DIVE INTO THE
AREA. THIS FRONT WILL ALSO BRING A BLAST OF COLD AIR WITH IT...WHICH
WILL CAUSE TEMPS TO PLUMMET INTO THE SINGLE DIGITS TO THE MID TEENS.
ALTHOUGH WINDS WILL NOT BE PARTICULARLY STRONG...WIND CHILLS ARE
STILL EXPECTED TO FALL WELL BELOW ZERO LATE TONIGHT THROUGH WEDNESDAY
MORNING.
WEDNESDAY WILL BE A CLOUDY AND COLD DAY WITH DAYTIME HIGHS NOT
CLIMBING OUT OF THE TEENS. A PROGRESSIVE UPPER LEVEL SHORTWAVE TROUGH
WILL SLIDE ACROSS THE REGION TOWARD THE EVENING. THIS COMBINED WITH
UPSLOPE LOW LEVEL FLOW AND THE ENTRANCE REGION OF AN UPPER JET STREAK
OVER THE SOUTHERN PLAINS WILL SUPPORT ANOTHER CHANCE FOR LIGHT SNOW.
ALTHOUGH THIS UPPER WAVE WILL LIFT ACROSS THE AREA QUICKLY...IT
APPEARS THIS SYSTEM MAY BE POTENT ENOUGH TO GENERATE A QUICK 1-2
INCHES OF SNOW. TEMPS WILL QUICKLY PLUMMET WHERE SUBZERO LOWS IN THE
OK PANHANDLE TO THE SINGLE DIGITS ELSEWHERE ARE POSSIBLE. WIND CHILLS
THROUGH THE WEDNESDAY NIGHT TO EARLY THURSDAY MORNING PERIOD WILL
ONCE AGAIN FALL BELOW ZERO.
LONG TERM...
CONTINUED COLD WITH ANOTHER CHANCE OF SNOW TOWARD THE END OF THE WEEK
AS THE SOUTHERN HIGH PLAINS REMAINS UNDER THE INFLUENCE OF A
PROGRESSIVE UPPER AIR PATTERN.
THE SNOW FROM WEDNESDAY WILL CONTINUE INTO THURSDAY BEFORE WINDING
DOWN BY THE EVENING. BY FRIDAY WINDS WILL SWING BACK AROUND TO THE
SOUTHWEST USHERING IN A BRIEF AND SLIGHT WARMUP WHERE HIGHS WILL
CLIMB ABOVE THE FREEZING MARK TO AREAS ON THE CAPROCK...WHILE
LOCATIONS EAST OF THE CAPROCK WILL BE HARD PRESSED TO CLIMB OUT OF
THE 20S. AN UPPER TROUGH WILL MOVE ACROSS THE NORTHERN PLAINS AND
WILL PUSH ANOTHER STRONG COLD FRONT THROUGH THE AREA. THIS FRONT CAN
GENERATE ANOTHER SHOT OF LIGHT SNOW LATE FRIDAY NIGHT. MEDIUM RANGE
MODELS DIFFER WITH THIS FRONT AND THE MAGNITUDE OF THE COLD AIR.
HAVE LEANED TOWARD THE COLDER AND WETTER ECMWF. ONCE THIS SYSTEM
SLIDES FURTHER TO THE EAST...WEAK UPPER RIDGING TAKES HOLD ACROSS THE
SOUTHWESTERN U.S. THIS WILL SUPPORT A MODEST WARMING TREND EARLY NEXT
WEEK.
CLK
FIRE WEATHER...
NO ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED THROUGH
THE WEEK AS RELATIVE HUMIDITY VALUES WILL REMAIN WELL ABOVE 20 PERCENT.
SEVERAL CHANCES FOR LIGHT SNOW IS EXPECTED THROUGH THE WEEK.
CLK
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...WINTER WEATHER ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR THE
FOLLOWING ZONES: BEAVER.
&&
$$
15/14
AREA FORECAST DISCUSSION
NWS AMARILLO TX
1206 PM CST TUE FEB 4 2014
.UPDATE...
LET THE WINTER WEATHER ADVISORY EXPIRE FOR THE MAJORITY OF THE TEXAS
AND OKLAHOMA PANHANDLE AS HEAVY SNOW SHOWERS HAVE MOVED OUT OF THE
AREA. THE EASTERN AND CENTRAL OKLAHOMA PANHANDLE AND NORTHEASTERN
TEXAS PANHANDLE REMAINS IN THE ADVISORY THROUGH 2 PM AS SNOW IS
CONTINUING TO OCCUR. AN ADDITIONAL ONE INCH MAY BE POSSIBLE ACROSS
PARTS OF BEAVER AND LIPSCOMB COUNTIES WITH LESS AMOUNTS EXPECTED
ACROSS THE REST OF THE ADVISORY AREA. LIGHT SNOW WILL BE POSSIBLE
THROUGH THE LATE EVENING HOURS WITH ADDITIONAL ACCUMULATIONS EXPECTED
TO BE LESS THAN A QUARTER INCH.
&&
.PREV DISCUSSION... /ISSUED 1129 AM CST TUE FEB 4 2014/
AVIATION...
NORTH WINDS IN THE 15 TO 20 KNOT RANGE WILL PREVAIL THROUGH THIS
FORECAST. SOME LIGHT SNOW WILL STILL BE POSSIBLE AT THE GUY AND AMA
TAF SITES THIS AFTERNOON...BUT FOR THE MOST PART...THE ORGANIZED
SNOW IS MOVING AWAY. IFR CONDITIONS WILL CONTINUE THROUGH MOST OF THE
NIGHT AT DHT AND GUY WITH CONDITIONS IMPROVING INTO THE MVFR RANGE
WEDNESDAY MORNING. IFR CONDITIONS AT AMA WILL GRADUALLY IMPROVE THIS
EVENING INTO THE MVFR RANGE.
PREV DISCUSSION... /ISSUED 551 AM CST TUE FEB 4 2014/
AVIATION...
FOR THE 12Z TAFS...LIGHT TO OCCASIONALLY MODERATE SNOW AND ASSOCIATED
LOW CIGS AND VSBYS WILL CONTINUE AT ALL TERMINAL SITES THIS
MORNING...WITH CONDITIONS GRADUALLY IMPROVING FROM SW TO NE ACROSS
THE AREA AS THE DAY WEARS ON. THIS IS REFLECTED IN THE TAFS. CIGS MAY
RISE INTO THE MVFR CATEGORY DURG THE COURSE OF TODAY BEFORE POSSIBLY
FALLING TO IFR AFTER SUNSET THIS EVENING AS HINTED AT IN LATEST MODEL
GUIDANCE.
ANDRADE
PREV DISCUSSION... /ISSUED 515 AM CST TUE FEB 4 2014/
SHORT TERM...SNOWFALL POTENTIAL AND COLD TEMPS ARE THE MAIN WEATHER
CONCERNS TODAY AND WEDNESDAY.
LIGHT TO MODERATE SNOW HAS INCREASED ACROSS THE TX/OK PANHANDLES
EARLY THIS MORNING AHEAD OF AN UPPER TROUGH OVER WEST TX. CURRENT
WATER VAPOR SATELLITE IMAGERY SHOWS ENHANCED CLOUD TOPS OVER NORTHERN
OK AND SOUTHERN KS...INDICATING WHERE THE HEAVIER BANDS OF SNOW ARE
LOCATED. HOWEVER FURTHER WEST...UPPER LIFT ASSOCIATED WITH THIS
SYSTEM AND ABUNDANT LOW-LEVEL MOISTURE OVER THE AREA WILL CONTINUE
TO SUPPORT SNOW THROUGHOUT MUCH OF THE DAY. STILL LOOKS LIKE THE
EASTERN OK PANHANDLE AND THE NORTHEASTERN TX PANHANDLE WILL BE THE
FAVORED AREAS FOR THE HEAVIER SNOWFALL ALTHOUGH THE RUC HAS THE
HIGHER SNOW TOTALS OVER SOUTHERN KS WHILE THE CURRENT HPC WINTER WX
DESK HAS LOWERED SNOWFALL TOTALS ACROSS THE AREA. GIVEN THIS AND THE
LATER ONSET OF SNOW...HAVE TRIMMED SNOWFALL TOTALS A TAD ALTHOUGH
STILL LOOKING TOTAL STORM ACCUMULATIONS OF 1 TO 5 INCHES. WILL
CONTINUE WITH THE WINTER WX ADVISORY FOR ALL OF THE CWA BUT WILL HOLD
OFF ON ISSUING A WINTER STORM WARNING FOR BEAVER COUNTY AS CONFIDENCE
OF THIS AREA RECEIVING ACCUMULATING SNOWS OF 6+ INCHES IS NOT HIGH.
SNOW WILL GRADUALLY END BY THIS EVENING ALTHOUGH THE WESTERN OK AND
NORTHWESTERN TX PANHANDLE CAN CONTINUE TO SEE LIGHT SNOW THIS
EVENING IN ASSOCIATION TO A STRONG COLD FRONT THAT WILL DIVE INTO THE
AREA. THIS FRONT WILL ALSO BRING A BLAST OF COLD AIR WITH IT...WHICH
WILL CAUSE TEMPS TO PLUMMET INTO THE SINGLE DIGITS TO THE MID TEENS.
ALTHOUGH WINDS WILL NOT BE PARTICULARLY STRONG...WIND CHILLS ARE
STILL EXPECTED TO FALL WELL BELOW ZERO LATE TONIGHT THROUGH WEDNESDAY
MORNING.
WEDNESDAY WILL BE A CLOUDY AND COLD DAY WITH DAYTIME HIGHS NOT
CLIMBING OUT OF THE TEENS. A PROGRESSIVE UPPER LEVEL SHORTWAVE TROUGH
WILL SLIDE ACROSS THE REGION TOWARD THE EVENING. THIS COMBINED WITH
UPSLOPE LOW LEVEL FLOW AND THE ENTRANCE REGION OF AN UPPER JET STREAK
OVER THE SOUTHERN PLAINS WILL SUPPORT ANOTHER CHANCE FOR LIGHT SNOW.
ALTHOUGH THIS UPPER WAVE WILL LIFT ACROSS THE AREA QUICKLY...IT
APPEARS THIS SYSTEM MAY BE POTENT ENOUGH TO GENERATE A QUICK 1-2
INCHES OF SNOW. TEMPS WILL QUICKLY PLUMMET WHERE SUBZERO LOWS IN THE
OK PANHANDLE TO THE SINGLE DIGITS ELSEWHERE ARE POSSIBLE. WIND CHILLS
THROUGH THE WEDNESDAY NIGHT TO EARLY THURSDAY MORNING PERIOD WILL
ONCE AGAIN FALL BELOW ZERO.
LONG TERM...
CONTINUED COLD WITH ANOTHER CHANCE OF SNOW TOWARD THE END OF THE WEEK
AS THE SOUTHERN HIGH PLAINS REMAINS UNDER THE INFLUENCE OF A
PROGRESSIVE UPPER AIR PATTERN.
THE SNOW FROM WEDNESDAY WILL CONTINUE INTO THURSDAY BEFORE WINDING
DOWN BY THE EVENING. BY FRIDAY WINDS WILL SWING BACK AROUND TO THE
SOUTHWEST USHERING IN A BRIEF AND SLIGHT WARMUP WHERE HIGHS WILL
CLIMB ABOVE THE FREEZING MARK TO AREAS ON THE CAPROCK...WHILE
LOCATIONS EAST OF THE CAPROCK WILL BE HARD PRESSED TO CLIMB OUT OF
THE 20S. AN UPPER TROUGH WILL MOVE ACROSS THE NORTHERN PLAINS AND
WILL PUSH ANOTHER STRONG COLD FRONT THROUGH THE AREA. THIS FRONT CAN
GENERATE ANOTHER SHOT OF LIGHT SNOW LATE FRIDAY NIGHT. MEDIUM RANGE
MODELS DIFFER WITH THIS FRONT AND THE MAGNITUDE OF THE COLD AIR.
HAVE LEANED TOWARD THE COLDER AND WETTER ECMWF. ONCE THIS SYSTEM
SLIDES FURTHER TO THE EAST...WEAK UPPER RIDGING TAKES HOLD ACROSS THE
SOUTHWESTERN U.S. THIS WILL SUPPORT A MODEST WARMING TREND EARLY NEXT
WEEK.
CLK
FIRE WEATHER...
NO ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED THROUGH
THE WEEK AS RELATIVE HUMIDITY VALUES WILL REMAIN WELL ABOVE 20 PERCENT.
SEVERAL CHANCES FOR LIGHT SNOW IS EXPECTED THROUGH THE WEEK.
CLK
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...WINTER WEATHER ADVISORY UNTIL 2 PM CST THIS AFTERNOON FOR THE
FOLLOWING ZONES: HANSFORD...LIPSCOMB...OCHILTREE.
OK...WINTER WEATHER ADVISORY UNTIL 2 PM CST THIS AFTERNOON FOR THE
FOLLOWING ZONES: BEAVER...TEXAS.
&&
$$
15/14
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
1129 AM CST TUE FEB 4 2014
.AVIATION...
NORTH WINDS IN THE 15 TO 20 KNOT RANGE WILL PREVAIL THROUGH THIS
FORECAST. SOME LIGHT SNOW WILL STILL BE POSSIBLE AT THE GUY AND AMA
TAF SITES THIS AFTERNOON...BUT FOR THE MOST PART...THE ORGANIZED
SNOW IS MOVING AWAY. IFR CONDITIONS WILL CONTINUE THROUGH MOST OF THE
NIGHT AT DHT AND GUY WITH CONDITIONS IMPROVING INTO THE MVFR RANGE
WEDNESDAY MORNING. IFR CONDITIONS AT AMA WILL GRADUALLY IMPROVE THIS
EVENING INTO THE MVFR RANGE.
&&
.PREV DISCUSSION... /ISSUED 551 AM CST TUE FEB 4 2014/
AVIATION...
FOR THE 12Z TAFS...LIGHT TO OCCASIONALLY MODERATE SNOW AND ASSOCIATED
LOW CIGS AND VSBYS WILL CONTINUE AT ALL TERMINAL SITES THIS
MORNING...WITH CONDITIONS GRADUALLY IMPROVING FROM SW TO NE ACROSS
THE AREA AS THE DAY WEARS ON. THIS IS REFLECTED IN THE TAFS. CIGS MAY
RISE INTO THE MVFR CATEGORY DURG THE COURSE OF TODAY BEFORE POSSIBLY
FALLING TO IFR AFTER SUNSET THIS EVENING AS HINTED AT IN LATEST MODEL
GUIDANCE.
ANDRADE
PREV DISCUSSION... /ISSUED 515 AM CST TUE FEB 4 2014/
SHORT TERM...SNOWFALL POTENTIAL AND COLD TEMPS ARE THE MAIN WEATHER
CONCERNS TODAY AND WEDNESDAY.
LIGHT TO MODERATE SNOW HAS INCREASED ACROSS THE TX/OK PANHANDLES
EARLY THIS MORNING AHEAD OF AN UPPER TROUGH OVER WEST TX. CURRENT
WATER VAPOR SATELLITE IMAGERY SHOWS ENHANCED CLOUD TOPS OVER NORTHERN
OK AND SOUTHERN KS...INDICATING WHERE THE HEAVIER BANDS OF SNOW ARE
LOCATED. HOWEVER FURTHER WEST...UPPER LIFT ASSOCIATED WITH THIS
SYSTEM AND ABUNDANT LOW-LEVEL MOISTURE OVER THE AREA WILL CONTINUE
TO SUPPORT SNOW THROUGHOUT MUCH OF THE DAY. STILL LOOKS LIKE THE
EASTERN OK PANHANDLE AND THE NORTHEASTERN TX PANHANDLE WILL BE THE
FAVORED AREAS FOR THE HEAVIER SNOWFALL ALTHOUGH THE RUC HAS THE
HIGHER SNOW TOTALS OVER SOUTHERN KS WHILE THE CURRENT HPC WINTER WX
DESK HAS LOWERED SNOWFALL TOTALS ACROSS THE AREA. GIVEN THIS AND THE
LATER ONSET OF SNOW...HAVE TRIMMED SNOWFALL TOTALS A TAD ALTHOUGH
STILL LOOKING TOTAL STORM ACCUMULATIONS OF 1 TO 5 INCHES. WILL
CONTINUE WITH THE WINTER WX ADVISORY FOR ALL OF THE CWA BUT WILL HOLD
OFF ON ISSUING A WINTER STORM WARNING FOR BEAVER COUNTY AS CONFIDENCE
OF THIS AREA RECEIVING ACCUMULATING SNOWS OF 6+ INCHES IS NOT HIGH.
SNOW WILL GRADUALLY END BY THIS EVENING ALTHOUGH THE WESTERN OK AND
NORTHWESTERN TX PANHANDLE CAN CONTINUE TO SEE LIGHT SNOW THIS
EVENING IN ASSOCIATION TO A STRONG COLD FRONT THAT WILL DIVE INTO THE
AREA. THIS FRONT WILL ALSO BRING A BLAST OF COLD AIR WITH IT...WHICH
WILL CAUSE TEMPS TO PLUMMET INTO THE SINGLE DIGITS TO THE MID TEENS.
ALTHOUGH WINDS WILL NOT BE PARTICULARLY STRONG...WIND CHILLS ARE
STILL EXPECTED TO FALL WELL BELOW ZERO LATE TONIGHT THROUGH WEDNESDAY
MORNING.
WEDNESDAY WILL BE A CLOUDY AND COLD DAY WITH DAYTIME HIGHS NOT
CLIMBING OUT OF THE TEENS. A PROGRESSIVE UPPER LEVEL SHORTWAVE TROUGH
WILL SLIDE ACROSS THE REGION TOWARD THE EVENING. THIS COMBINED WITH
UPSLOPE LOW LEVEL FLOW AND THE ENTRANCE REGION OF AN UPPER JET STREAK
OVER THE SOUTHERN PLAINS WILL SUPPORT ANOTHER CHANCE FOR LIGHT SNOW.
ALTHOUGH THIS UPPER WAVE WILL LIFT ACROSS THE AREA QUICKLY...IT
APPEARS THIS SYSTEM MAY BE POTENT ENOUGH TO GENERATE A QUICK 1-2
INCHES OF SNOW. TEMPS WILL QUICKLY PLUMMET WHERE SUBZERO LOWS IN THE
OK PANHANDLE TO THE SINGLE DIGITS ELSEWHERE ARE POSSIBLE. WIND CHILLS
THROUGH THE WEDNESDAY NIGHT TO EARLY THURSDAY MORNING PERIOD WILL
ONCE AGAIN FALL BELOW ZERO.
LONG TERM...
CONTINUED COLD WITH ANOTHER CHANCE OF SNOW TOWARD THE END OF THE WEEK
AS THE SOUTHERN HIGH PLAINS REMAINS UNDER THE INFLUENCE OF A
PROGRESSIVE UPPER AIR PATTERN.
THE SNOW FROM WEDNESDAY WILL CONTINUE INTO THURSDAY BEFORE WINDING
DOWN BY THE EVENING. BY FRIDAY WINDS WILL SWING BACK AROUND TO THE
SOUTHWEST USHERING IN A BRIEF AND SLIGHT WARMUP WHERE HIGHS WILL
CLIMB ABOVE THE FREEZING MARK TO AREAS ON THE CAPROCK...WHILE
LOCATIONS EAST OF THE CAPROCK WILL BE HARD PRESSED TO CLIMB OUT OF
THE 20S. AN UPPER TROUGH WILL MOVE ACROSS THE NORTHERN PLAINS AND
WILL PUSH ANOTHER STRONG COLD FRONT THROUGH THE AREA. THIS FRONT CAN
GENERATE ANOTHER SHOT OF LIGHT SNOW LATE FRIDAY NIGHT. MEDIUM RANGE
MODELS DIFFER WITH THIS FRONT AND THE MAGNITUDE OF THE COLD AIR.
HAVE LEANED TOWARD THE COLDER AND WETTER ECMWF. ONCE THIS SYSTEM
SLIDES FURTHER TO THE EAST...WEAK UPPER RIDGING TAKES HOLD ACROSS THE
SOUTHWESTERN U.S. THIS WILL SUPPORT A MODEST WARMING TREND EARLY NEXT
WEEK.
CLK
FIRE WEATHER...
NO ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED THROUGH
THE WEEK AS RELATIVE HUMIDITY VALUES WILL REMAIN WELL ABOVE 20 PERCENT.
SEVERAL CHANCES FOR LIGHT SNOW IS EXPECTED THROUGH THE WEEK.
CLK
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...WINTER WEATHER ADVISORY UNTIL 2 PM CST THIS AFTERNOON FOR THE
FOLLOWING ZONES: DALLAM...GRAY...HANSFORD...HEMPHILL...
HUTCHINSON...LIPSCOMB...OCHILTREE...ROBERTS...SHERMAN...
WHEELER.
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR THE FOLLOWING
ZONES: ARMSTRONG...CARSON...COLLINGSWORTH...DEAF SMITH...
DONLEY...HARTLEY...MOORE...OLDHAM...POTTER...RANDALL.
OK...WINTER WEATHER ADVISORY UNTIL 2 PM CST THIS AFTERNOON FOR THE
FOLLOWING ZONES: BEAVER...CIMARRON...TEXAS.
&&
$$
15/14
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
551 AM CST TUE FEB 4 2014
.AVIATION...
FOR THE 12Z TAFS...LIGHT TO OCCASIONALLY MODERATE SNOW AND ASSOCIATED
LOW CIGS AND VSBYS WILL CONTINUE AT ALL TERMINAL SITES THIS
MORNING...WITH CONDITIONS GRADUALLY IMPROVING FROM SW TO NE ACROSS
THE AREA AS THE DAY WEARS ON. THIS IS REFLECTED IN THE TAFS. CIGS MAY
RISE INTO THE MVFR CATEGORY DURG THE COURSE OF TODAY BEFORE POSSIBLY
FALLING TO IFR AFTER SUNSET THIS EVENING AS HINTED AT IN LATEST MODEL
GUIDANCE.
ANDRADE
&&
.PREV DISCUSSION... /ISSUED 515 AM CST TUE FEB 4 2014/
SHORT TERM...SNOWFALL POTENTIAL AND COLD TEMPS ARE THE MAIN WEATHER
CONCERNS TODAY AND WEDNESDAY.
LIGHT TO MODERATE SNOW HAS INCREASED ACROSS THE TX/OK PANHANDLES
EARLY THIS MORNING AHEAD OF AN UPPER TROUGH OVER WEST TX. CURRENT
WATER VAPOR SATELLITE IMAGERY SHOWS ENHANCED CLOUD TOPS OVER NORTHERN
OK AND SOUTHERN KS...INDICATING WHERE THE HEAVIER BANDS OF SNOW ARE
LOCATED. HOWEVER FURTHER WEST...UPPER LIFT ASSOCIATED WITH THIS
SYSTEM AND ABUNDANT LOW-LEVEL MOISTURE OVER THE AREA WILL CONTINUE
TO SUPPORT SNOW THROUGHOUT MUCH OF THE DAY. STILL LOOKS LIKE THE
EASTERN OK PANHANDLE AND THE NORTHEASTERN TX PANHANDLE WILL BE THE
FAVORED AREAS FOR THE HEAVIER SNOWFALL ALTHOUGH THE RUC HAS THE
HIGHER SNOW TOTALS OVER SOUTHERN KS WHILE THE CURRENT HPC WINTER WX
DESK HAS LOWERED SNOWFALL TOTALS ACROSS THE AREA. GIVEN THIS AND THE
LATER ONSET OF SNOW...HAVE TRIMMED SNOWFALL TOTALS A TAD ALTHOUGH
STILL LOOKING TOTAL STORM ACCUMULATIONS OF 1 TO 5 INCHES. WILL
CONTINUE WITH THE WINTER WX ADVISORY FOR ALL OF THE CWA BUT WILL HOLD
OFF ON ISSUING A WINTER STORM WARNING FOR BEAVER COUNTY AS CONFIDENCE
OF THIS AREA RECEIVING ACCUMULATING SNOWS OF 6+ INCHES IS NOT HIGH.
SNOW WILL GRADUALLY END BY THIS EVENING ALTHOUGH THE WESTERN OK AND
NORTHWESTERN TX PANHANDLE CAN CONTINUE TO SEE LIGHT SNOW THIS
EVENING IN ASSOCIATION TO A STRONG COLD FRONT THAT WILL DIVE INTO THE
AREA. THIS FRONT WILL ALSO BRING A BLAST OF COLD AIR WITH IT...WHICH
WILL CAUSE TEMPS TO PLUMMET INTO THE SINGLE DIGITS TO THE MID TEENS.
ALTHOUGH WINDS WILL NOT BE PARTICULARLY STRONG...WIND CHILLS ARE
STILL EXPECTED TO FALL WELL BELOW ZERO LATE TONIGHT THROUGH WEDNESDAY
MORNING.
WEDNESDAY WILL BE A CLOUDY AND COLD DAY WITH DAYTIME HIGHS NOT
CLIMBING OUT OF THE TEENS. A PROGRESSIVE UPPER LEVEL SHORTWAVE TROUGH
WILL SLIDE ACROSS THE REGION TOWARD THE EVENING. THIS COMBINED WITH
UPSLOPE LOW LEVEL FLOW AND THE ENTRANCE REGION OF AN UPPER JET STREAK
OVER THE SOUTHERN PLAINS WILL SUPPORT ANOTHER CHANCE FOR LIGHT SNOW.
ALTHOUGH THIS UPPER WAVE WILL LIFT ACROSS THE AREA QUICKLY...IT
APPEARS THIS SYSTEM MAY BE POTENT ENOUGH TO GENERATE A QUICK 1-2
INCHES OF SNOW. TEMPS WILL QUICKLY PLUMMET WHERE SUBZERO LOWS IN THE
OK PANHANDLE TO THE SINGLE DIGITS ELSEWHERE ARE POSSIBLE. WIND CHILLS
THROUGH THE WEDNESDAY NIGHT TO EARLY THURSDAY MORNING PERIOD WILL
ONCE AGAIN FALL BELOW ZERO.
LONG TERM...
CONTINUED COLD WITH ANOTHER CHANCE OF SNOW TOWARD THE END OF THE WEEK
AS THE SOUTHERN HIGH PLAINS REMAINS UNDER THE INFLUENCE OF A
PROGRESSIVE UPPER AIR PATTERN.
THE SNOW FROM WEDNESDAY WILL CONTINUE INTO THURSDAY BEFORE WINDING
DOWN BY THE EVENING. BY FRIDAY WINDS WILL SWING BACK AROUND TO THE
SOUTHWEST USHERING IN A BRIEF AND SLIGHT WARMUP WHERE HIGHS WILL
CLIMB ABOVE THE FREEZING MARK TO AREAS ON THE CAPROCK...WHILE
LOCATIONS EAST OF THE CAPROCK WILL BE HARD PRESSED TO CLIMB OUT OF
THE 20S. AN UPPER TROUGH WILL MOVE ACROSS THE NORTHERN PLAINS AND
WILL PUSH ANOTHER STRONG COLD FRONT THROUGH THE AREA. THIS FRONT CAN
GENERATE ANOTHER SHOT OF LIGHT SNOW LATE FRIDAY NIGHT. MEDIUM RANGE
MODELS DIFFER WITH THIS FRONT AND THE MAGNITUDE OF THE COLD AIR.
HAVE LEANED TOWARD THE COLDER AND WETTER ECMWF. ONCE THIS SYSTEM
SLIDES FURTHER TO THE EAST...WEAK UPPER RIDGING TAKES HOLD ACROSS THE
SOUTHWESTERN U.S. THIS WILL SUPPORT A MODEST WARMING TREND EARLY NEXT
WEEK.
CLK
FIRE WEATHER...
NO ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED THROUGH
THE WEEK AS RELATIVE HUMIDITY VALUES WILL REMAIN WELL ABOVE 20 PERCENT.
SEVERAL CHANCES FOR LIGHT SNOW IS EXPECTED THROUGH THE WEEK.
CLK
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...WINTER WEATHER ADVISORY UNTIL 2 PM CST THIS AFTERNOON FOR THE
FOLLOWING ZONES: DALLAM...GRAY...HANSFORD...HEMPHILL...
HUTCHINSON...LIPSCOMB...OCHILTREE...ROBERTS...SHERMAN...
WHEELER.
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR THE FOLLOWING
ZONES: ARMSTRONG...CARSON...COLLINGSWORTH...DEAF SMITH...
DONLEY...HARTLEY...MOORE...OLDHAM...POTTER...RANDALL.
OK...WINTER WEATHER ADVISORY UNTIL 2 PM CST THIS AFTERNOON FOR THE
FOLLOWING ZONES: BEAVER...CIMARRON...TEXAS.
&&
$$
AREA FORECAST DISCUSSION
NWS AMARILLO TX
515 AM CST TUE FEB 4 2014
.SHORT TERM...SNOWFALL POTENTIAL AND COLD TEMPS ARE THE MAIN WEATHER
CONCERNS TODAY AND WEDNESDAY.
LIGHT TO MODERATE SNOW HAS INCREASED ACROSS THE TX/OK PANHANDLES
EARLY THIS MORNING AHEAD OF AN UPPER TROUGH OVER WEST TX. CURRENT
WATER VAPOR SATELLITE IMAGERY SHOWS ENHANCED CLOUD TOPS OVER NORTHERN
OK AND SOUTHERN KS...INDICATING WHERE THE HEAVIER BANDS OF SNOW ARE
LOCATED. HOWEVER FURTHER WEST...UPPER LIFT ASSOCIATED WITH THIS
SYSTEM AND ABUNDANT LOW-LEVEL MOISTURE OVER THE AREA WILL CONTINUE
TO SUPPORT SNOW THROUGHOUT MUCH OF THE DAY. STILL LOOKS LIKE THE
EASTERN OK PANHANDLE AND THE NORTHEASTERN TX PANHANDLE WILL BE THE
FAVORED AREAS FOR THE HEAVIER SNOWFALL ALTHOUGH THE RUC HAS THE
HIGHER SNOW TOTALS OVER SOUTHERN KS WHILE THE CURRENT HPC WINTER WX
DESK HAS LOWERED SNOWFALL TOTALS ACROSS THE AREA. GIVEN THIS AND THE
LATER ONSET OF SNOW...HAVE TRIMMED SNOWFALL TOTALS A TAD ALTHOUGH
STILL LOOKING TOTAL STORM ACCUMULATIONS OF 1 TO 5 INCHES. WILL
CONTINUE WITH THE WINTER WX ADVISORY FOR ALL OF THE CWA BUT WILL HOLD
OFF ON ISSUING A WINTER STORM WARNING FOR BEAVER COUNTY AS CONFIDENCE
OF THIS AREA RECEIVING ACCUMULATING SNOWS OF 6+ INCHES IS NOT HIGH.
SNOW WILL GRADUALLY END BY THIS EVENING ALTHOUGH THE WESTERN OK AND
NORTHWESTERN TX PANHANDLE CAN CONTINUE TO SEE LIGHT SNOW THIS
EVENING IN ASSOCIATION TO A STRONG COLD FRONT THAT WILL DIVE INTO THE
AREA. THIS FRONT WILL ALSO BRING A BLAST OF COLD AIR WITH IT...WHICH
WILL CAUSE TEMPS TO PLUMMET INTO THE SINGLE DIGITS TO THE MID TEENS.
ALTHOUGH WINDS WILL NOT BE PARTICULARLY STRONG...WIND CHILLS ARE
STILL EXPECTED TO FALL WELL BELOW ZERO LATE TONIGHT THROUGH WEDNESDAY
MORNING.
WEDNESDAY WILL BE A CLOUDY AND COLD DAY WITH DAYTIME HIGHS NOT
CLIMBING OUT OF THE TEENS. A PROGRESSIVE UPPER LEVEL SHORTWAVE TROUGH
WILL SLIDE ACROSS THE REGION TOWARD THE EVENING. THIS COMBINED WITH
UPSLOPE LOW LEVEL FLOW AND THE ENTRANCE REGION OF AN UPPER JET STREAK
OVER THE SOUTHERN PLAINS WILL SUPPORT ANOTHER CHANCE FOR LIGHT SNOW.
ALTHOUGH THIS UPPER WAVE WILL LIFT ACROSS THE AREA QUICKLY...IT
APPEARS THIS SYSTEM MAY BE POTENT ENOUGH TO GENERATE A QUICK 1-2
INCHES OF SNOW. TEMPS WILL QUICKLY PLUMMET WHERE SUBZERO LOWS IN THE
OK PANHANDLE TO THE SINGLE DIGITS ELSEWHERE ARE POSSIBLE. WIND CHILLS
THROUGH THE WEDNESDAY NIGHT TO EARLY THURSDAY MORNING PERIOD WILL
ONCE AGAIN FALL BELOW ZERO.
.LONG TERM...
CONTINUED COLD WITH ANOTHER CHANCE OF SNOW TOWARD THE END OF THE WEEK
AS THE SOUTHERN HIGH PLAINS REMAINS UNDER THE INFLUENCE OF A
PROGRESSIVE UPPER AIR PATTERN.
THE SNOW FROM WEDNESDAY WILL CONTINUE INTO THURSDAY BEFORE WINDING
DOWN BY THE EVENING. BY FRIDAY WINDS WILL SWING BACK AROUND TO THE
SOUTHWEST USHERING IN A BRIEF AND SLIGHT WARMUP WHERE HIGHS WILL
CLIMB ABOVE THE FREEZING MARK TO AREAS ON THE CAPROCK...WHILE
LOCATIONS EAST OF THE CAPROCK WILL BE HARD PRESSED TO CLIMB OUT OF
THE 20S. AN UPPER TROUGH WILL MOVE ACROSS THE NORTHERN PLAINS AND
WILL PUSH ANOTHER STRONG COLD FRONT THROUGH THE AREA. THIS FRONT CAN
GENERATE ANOTHER SHOT OF LIGHT SNOW LATE FRIDAY NIGHT. MEDIUM RANGE
MODELS DIFFER WITH THIS FRONT AND THE MAGNITUDE OF THE COLD AIR.
HAVE LEANED TOWARD THE COLDER AND WETTER ECMWF. ONCE THIS SYSTEM
SLIDES FURTHER TO THE EAST...WEAK UPPER RIDGING TAKES HOLD ACROSS THE
SOUTHWESTERN U.S. THIS WILL SUPPORT A MODEST WARMING TREND EARLY NEXT
WEEK.
CLK
&&
.FIRE WEATHER...
NO ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED THROUGH
THE WEEK AS RELATIVE HUMIDITY VALUES WILL REMAIN WELL ABOVE 20 PERCENT.
SEVERAL CHANCES FOR LIGHT SNOW IS EXPECTED THROUGH THE WEEK.
CLK
&&
.PRELIMINARY POINT TEMPS/POPS...
AMARILLO TX 33 10 18 4 14 / 60 10 10 40 40
BEAVER OK 26 3 9 1 11 / 100 20 10 30 40
BOISE CITY OK 23 2 14 0 16 / 80 30 10 30 40
BORGER TX 29 11 16 3 15 / 80 10 10 40 40
BOYS RANCH TX 33 13 21 8 20 / 60 20 10 40 40
CANYON TX 33 13 20 6 16 / 50 10 10 40 40
CLARENDON TX 32 13 19 5 12 / 70 5 10 30 40
DALHART TX 31 9 16 3 19 / 80 20 10 40 40
GUYMON OK 25 4 10 0 13 / 90 20 10 30 40
HEREFORD TX 32 14 21 7 19 / 50 10 10 40 40
LIPSCOMB TX 29 6 10 2 12 / 100 10 10 30 40
PAMPA TX 29 7 15 2 11 / 80 10 10 40 40
SHAMROCK TX 32 11 16 5 13 / 80 10 10 30 40
WELLINGTON TX 33 15 18 7 13 / 70 5 10 30 40
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...WINTER WEATHER ADVISORY UNTIL 2 PM CST THIS AFTERNOON FOR THE
FOLLOWING ZONES: DALLAM...GRAY...HANSFORD...HEMPHILL...
HUTCHINSON...LIPSCOMB...OCHILTREE...ROBERTS...SHERMAN...
WHEELER.
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR THE FOLLOWING
ZONES: ARMSTRONG...CARSON...COLLINGSWORTH...DEAF SMITH...
DONLEY...HARTLEY...MOORE...OLDHAM...POTTER...RANDALL.
OK...WINTER WEATHER ADVISORY UNTIL 2 PM CST THIS AFTERNOON FOR THE
FOLLOWING ZONES: BEAVER...CIMARRON...TEXAS.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
1124 PM CST MON FEB 3 2014
.AVIATION...
SOUTHEAST SURFACE WINDS AROUND 10 KT OVERNIGHT WILL BACK...BECOMING
EAST BY SUNRISE. ISENTROPIC LIFT AND UPSLOPE FLOW WILL SUSTAIN
DEVELOPMENT OF LIFR CEILINGS TONIGHT AND TUESDAY MORNING. FREEZING
DRIZZLE WILL GIVE WAY TO LIGHT SNOW AS STRONG UPPER-LEVEL FORCING
ARRIVES FROM SOUTHWEST. SURFACE WINDS BECOME NORTHERLY BEFORE NOON
TUESDAY. CEILINGS EXPECTED TO RISE INTO MVFR RANGE BETWEEN 17Z AND
22Z TUESDAY AS THREAT FOR FURTHER LIGHT SNOW DIMINISHES. CEILINGS
MAY LOWER INTO IFR RANGE AFTER 00Z WEDNESDAY AS COLD NORTH LOW-LEVEL
WINDS CONTINUE.
COCKRELL
&&
.PREV DISCUSSION... /ISSUED 1051 PM CST MON FEB 3 2014/
UPDATE...
LOW CLOUDS, FREEZING FOG, AND FREEZING DRIZZLE HAVE RAPIDLY DEVELOPED
THIS EVENING IN RESPONSE TO AN UPPER TROUGH LOCATED OVER SOUTHWESTERN
NEW MEXICO. THIS TROUGH IS BEGINNING TO LIFT NORTHEAST TOWARD WEST
TEXAS, AND FORCING FOR ASCENT IS ALREADY INCREASING TO OUR SOUTH AND
WEST WHERE SNOW HAS DEVELOPED OVER SOUTHEASTERN NEW MEXICO. WATER
VAPOR IMAGERY SHOWS A POTENTIAL VORTICITY ANOMALY THAT APPEARS TO BE
ON A TRAJECTORY TOWARD THE SOUTHWESTERN/SOUTHERN TEXAS PANHANDLE LATE
TONIGHT. RAP AND NAM GUIDANCE CONTINUE TO INDICATE SNOW DEVELOPING
ACROSS THESE AREAS AFTER 1 AM AND SPREADING NORTH AND EAST, A SCENARIO
ALSO SUPPORTED BY THE TEXAS TECH WRF. THESE MODELS ALSO SHOW A BANDED
SNOW SIGNAL BETWEEN ADRIAN AND AMARILLO, LIKELY TIED TO DEEP, STRONG
UPPER-/LOWER-LEVEL COUPLING AND A TROWAL FEATURE. IF THE BAND
DEVELOPS FARTHER EAST, CLOSER TO AMARILLO, WE`RE CONCERNED THAT THE
MORNING COMMUTE ACROSS AMARILLO COULD BE SEVERELY IMPACTED. WE`LL
HAVE TO WATCH THIS CLOSELY, BUT WE`VE INCREASED SNOWFALL TOTALS
ACROSS THE SOUTHWESTERN TEXAS PANHANDLE AND ADDED DEAF SMITH COUNTY
TO THE WINTER WEATHER ADVISORY. WITHIN THIS BAND OF SNOW AN AVERAGE
SNOWFALL ACCUMULATION BETWEEN 1 AND 3 INCHES IS LIKELY, BUT A
LOCALIZED 5-INCH SNOWFALL TOTAL CAN`T BE COMPLETELY RULED OUT.
FARTHER NORTH AND EAST, OUR DILEMMA WAS WHETHER TO ISSUE A WINTER
STORM WARNING FOR BEAVER COUNTY. WE`RE STILL ON THE FENCE WITH THIS,
DESPITE STRONG UPPER-/LOWER-LEVEL COUPLING, A TROWAL MOVING OVER
THIS AREA, AND A LONGER PERIOD OF SNOWFALL. SREF PROBABILITIES FOR
4" SNOWFALL TOTALS HAVE FURTHER BEEN REDUCED ON THE 21Z RUN. HOWEVER,
WE FEEL THE SREF IS TOO LOW ON SNOWFALL TOTALS, LIKELY A RESULT OF
ITS SNOW-TO-LIQUID RATIOS BEING BASED ON 2 METER TEMPERATURES. USING
ITS 2 METER TEMPS, SNOW-TO-LIQUID RATIOS WOULD BE ABOUT 9.5:1, WHICH
SEEMS FAR TOO LOW IN THIS SETUP (WE`VE USED A 14:1 RATIO). STILL, WE
WOULDN`T BE SURPRISED IF THERE IS AN ISOLATED 6-INCH AMOUNT IN BEAVER
COUNTY, BUT OVERALL, THE OVERWHELMING MAJORITY OF THE TOTALS WILL
LIKELY BE UNDER 6 INCHES. ONE ADJUSTMENT WE DID MAKE TO THE WINTER
WEATHER ADVISORY ACROSS THE NORTHERN AND NORTHEASTERN PANHANDLES WAS
TO EXTEND IT UNTIL 2 PM AS THE SNOW LIKELY WON`T TAPER OFF UNTIL
EARLY TUESDAY AFTERNOON IN THESE AREAS.
JACKSON
PREV DISCUSSION... /ISSUED 539 PM CST MON FEB 3 2014/
AVIATION...
FOR THE 00Z TAFS, THIS IS A LOW CONFIDENCE FORECAST ON MANY ELEMENTS
AND ESPECIALLY TIMING THESE ELEMENTS. EXPECT CONDITIONS TO RAPIDLY
DETERIORATE AFTER 06Z AS -FZDZ BRIEFLY DEVELOPS BEFORE TRANSITIONING
TO SNOW. THERE IS A MODERATE TO HIGH PROBABILITY ALL TERMINALS COULD
BE AT OR BELOW AIRPORT MINIMUMS, PARTICULARLY AT KDHT AND KGUY.
CONDITIONS WILL SLOWLY IMPROVE AT KAMA FIRST, FOLLOWED BY KDHT, AND
FINALLY KGUY.
JACKSON
PREV DISCUSSION... /ISSUED 412 PM CST MON FEB 3 2014/
DISCUSSION...
FORECASTS CONCERNING THE POTENTIAL FOR ACCUMULATING SNOWFALL TONIGHT/
TUESDAY REMAIN QUITE COMPLEX. THE WINTER WEATHER ADVISORY HAS BEEN
EXTENDED TO INCLUDE MORE OF THE SOUTHWESTERN AND CENTRAL TEXAS
PANHANDLE...BUT WILL STILL EXCLUDE DEAF SMITH COUNTY. IT IS IMPORTANT
TO CONVEY VARIED IMPACTS WITH THIS EVENT...AS PORTIONS OF THE
SOUTHWESTERN PANHANDLE /INCLUDING AMARILLO/ WILL LIKELY EXPERIENCE
LOW-END ADVISORY ACCUMULATIONS /UP TO 1-2 INCHES/ WHILE THE
NORTHEASTERN TEXAS PANHANDLE WILL SEE HIGH-END ADVISORY ACCUMULATIONS
/3-5 INCHES/.
FORECAST SOUNDINGS SUGGEST INITIAL WARM AIR ADVECTION IN ADVANCE OF
THE APPROACHING STORM SYSTEM MAY RESULT IN RE-NEWED FREEZING DRIZZLE
OR LIGHT SNOW THIS EVENING...BUT THE MAIN IMPACTS FROM SNOW WILL
DEFINITELY FOCUS ON THE 06-18Z TIMEFRAME. THAT IS WHEN A SHARP AND
NEGATIVELY TILTED SHORTWAVE TROUGH WILL EJECT AND PROVIDE VERY DEEP
FORCING FOR ASCENT OVER THE PANHANDLES. THIS SYSTEM...NOW OVER
NORTHWESTERN MEXICO CURRENTLY HAS AN IMPRESSIVE WATER VAPOR
REPRESENTATION...AND THERE ARE CONCERNS THAT IT WILL EMERGE DEEPER
THAN PROGGED BY MOST MODELS. THE SYSTEM IS A MATCH FOR THE LAMBERT
TYPE-B SNOW PATTERN IN WEST TEXAS WHICH TENDS TO RESULT IN SOME OF
OUR HEAVIER SNOWFALLS. HOWEVER...MOST NWP CONTINUES PERSISTENT
DEPICTIONS OF PRECIPITATION SPREADING NORTHEASTWARD OVER THE
CENTRAL/EASTERN PANHANDLE AS JET DYNAMICS AND ASSOCIATED
FRONTOGENETICAL FORCING SPREAD NORTHEAST AND FOCUS OVER THE
NORTHEASTERN TEXAS PANHANDLE/EASTERN OKLAHOMA PANHANDLE. ALL
GUIDANCE...ONCE CORRECTED FOR KNOWN BIASES...IS IN GENERAL AGREEMENT
WITH POTENTIAL SNOW ACCUMULATIONS BETWEEN 2-5 INCHES NORTH OF THE
CANADIAN RIVER...ESPECIALLY OVER THE EASTERN PANHANDLES. THIS
INCLUDES THE CIPS ANALOG AND SREF ENSEMBLE GUIDANCE WHICH ONLY
DEPICTS A 15 PERCENT PROBABILITY OF 4 PLUS INCH ACCUMULATIONS. THIS
GUIDANCE LENDS UNCERTAINTY TO PATTERN RECOGNITION CONCEPTUAL MODELS
WHICH WOULD SUGGEST THE MORE STRINGENT 6 INCH WINTER STORM CRITERIA
COULD BE THREATENED. THIS UNCERTAINTY IS FURTHER EXACERBATED DUE TO
RECENT HIGH-RESOLUTION MODELS WHICH HAVE SHIFTED THE CORRIDOR OF
STRONGEST FORCING/HEAVY SNOW WESTWARD TOWARD THE CENTRAL PANHANDLE.
DUE TO THESE UNCERTAINTIES...WILL MAINTAIN/EXPAND THE CURRENT
ADVISORY BUT WILL SEGMENT IT TO REFLECT THE VARYING ACCUMULATIONS
WITH AN EMPHASIS ON NEAR WINTER STORM IMPACTS IN THE EASTERN OKLAHOMA
PANHANDLE AND THE NORTHEASTERN TEXAS PANHANDLE. IT IS POSSIBLE THAT
LOCALIZED 6 INCH AMOUNTS COULD MATERIALIZE THERE...AND ULTIMATELY
WARRANT A WINTER STORM WARNING UPGRADE.
THERE ARE OTHER TIMEFRAMES OF CONCERN IN THIS FORECAST PERIOD AS
WELL. ANOTHER INVASION OF ARCTIC AIR WILL PUSH SOUTHWARD IN THE WAKE
OF TOMORROW/S SYSTEM. PERIODS OF LIGHT SNOW APPEAR LIKELY WEDNESDAY
AND THURSDAY AS THE ENTRANCE REGION OF AN UPPER JET LINGERS ATOP
LIGHT UPSLOPE LOW LEVEL FLOW. THE NEXT POTENTIAL FOR SIGNIFICANT
WINTER PRECIPITATION MAY OCCUR BY THE WEEKEND AS ANOTHER SHARP UPPER
AIR TROUGH IS PROGGED BY THE LONG RANGE MODELS TO TRANSLATE OVER THE
SOUTHERN PLAINS.
FIRE WEATHER...
ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE NOT EXPECTED
THROUGH THE REST OF THE WEEK. SEVERAL OPPORTUNITIES FOR WETTING
MOISTURE WILL EXIST THROUGH THE UPCOMING WEEK..
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...WINTER WEATHER ADVISORY UNTIL 2 PM CST TUESDAY FOR THE FOLLOWING
ZONES: DALLAM...GRAY...HANSFORD...HEMPHILL...HUTCHINSON...
LIPSCOMB...OCHILTREE...ROBERTS...SHERMAN...WHEELER.
WINTER WEATHER ADVISORY UNTIL NOON CST TUESDAY FOR THE FOLLOWING
ZONES: ARMSTRONG...CARSON...COLLINGSWORTH...DEAF SMITH...
DONLEY...HARTLEY...MOORE...OLDHAM...POTTER...RANDALL.
OK...WINTER WEATHER ADVISORY UNTIL 2 PM CST TUESDAY FOR THE FOLLOWING
ZONES: BEAVER...CIMARRON...TEXAS.
&&
$$
03/13
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
1051 PM CST MON FEB 3 2014
.UPDATE...
LOW CLOUDS, FREEZING FOG, AND FREEZING DRIZZLE HAVE RAPIDLY DEVELOPED
THIS EVENING IN RESPONSE TO AN UPPER TROUGH LOCATED OVER SOUTHWESTERN
NEW MEXICO. THIS TROUGH IS BEGINNING TO LIFT NORTHEAST TOWARD WEST
TEXAS, AND FORCING FOR ASCENT IS ALREADY INCREASING TO OUR SOUTH AND
WEST WHERE SNOW HAS DEVELOPED OVER SOUTHEASTERN NEW MEXICO. WATER
VAPOR IMAGERY SHOWS A POTENTIAL VORTICITY ANOMALY THAT APPEARS TO BE
ON A TRAJECTORY TOWARD THE SOUTHWESTERN/SOUTHERN TEXAS PANHANDLE LATE
TONIGHT. RAP AND NAM GUIDANCE CONTINUE TO INDICATE SNOW DEVELOPING
ACROSS THESE AREAS AFTER 1 AM AND SPREADING NORTH AND EAST, A SCENARIO
ALSO SUPPORTED BY THE TEXAS TECH WRF. THESE MODELS ALSO SHOW A BANDED
SNOW SIGNAL BETWEEN ADRIAN AND AMARILLO, LIKELY TIED TO DEEP, STRONG
UPPER-/LOWER-LEVEL COUPLING AND A TROWAL FEATURE. IF THE BAND
DEVELOPS FARTHER EAST, CLOSER TO AMARILLO, WE`RE CONCERNED THAT THE
MORNING COMMUTE ACROSS AMARILLO COULD BE SEVERELY IMPACTED. WE`LL
HAVE TO WATCH THIS CLOSELY, BUT WE`VE INCREASED SNOWFALL TOTALS
ACROSS THE SOUTHWESTERN TEXAS PANHANDLE AND ADDED DEAF SMITH COUNTY
TO THE WINTER WEATHER ADVISORY. WITHIN THIS BAND OF SNOW AN AVERAGE
SNOWFALL ACCUMULATION BETWEEN 1 AND 3 INCHES IS LIKELY, BUT A
LOCALIZED 5-INCH SNOWFALL TOTAL CAN`T BE COMPLETELY RULED OUT.
FARTHER NORTH AND EAST, OUR DILEMMA WAS WHETHER TO ISSUE A WINTER
STORM WARNING FOR BEAVER COUNTY. WE`RE STILL ON THE FENCE WITH THIS,
DESPITE STRONG UPPER-/LOWER-LEVEL COUPLING, A TROWAL MOVING OVER
THIS AREA, AND A LONGER PERIOD OF SNOWFALL. SREF PROBABILITIES FOR
4" SNOWFALL TOTALS HAVE FURTHER BEEN REDUCED ON THE 21Z RUN. HOWEVER,
WE FEEL THE SREF IS TOO LOW ON SNOWFALL TOTALS, LIKELY A RESULT OF
ITS SNOW-TO-LIQUID RATIOS BEING BASED ON 2 METER TEMPERATURES. USING
ITS 2 METER TEMPS, SNOW-TO-LIQUID RATIOS WOULD BE ABOUT 9.5:1, WHICH
SEEMS FAR TOO LOW IN THIS SETUP (WE`VE USED A 14:1 RATIO). STILL, WE
WOULDN`T BE SURPRISED IF THERE IS AN ISOLATED 6-INCH AMOUNT IN BEAVER
COUNTY, BUT OVERALL, THE OVERWHELMING MAJORITY OF THE TOTALS WILL
LIKELY BE UNDER 6 INCHES. ONE ADJUSTMENT WE DID MAKE TO THE WINTER
WEATHER ADVISORY ACROSS THE NORTHERN AND NORTHEASTERN PANHANDLES WAS
TO EXTEND IT UNTIL 2 PM AS THE SNOW LIKELY WON`T TAPER OFF UNTIL
EARLY TUESDAY AFTERNOON IN THESE AREAS.
JACKSON
&&
.PREV DISCUSSION... /ISSUED 539 PM CST MON FEB 3 2014/
AVIATION...
FOR THE 00Z TAFS, THIS IS A LOW CONFIDENCE FORECAST ON MANY ELEMENTS
AND ESPECIALLY TIMING THESE ELEMENTS. EXPECT CONDITIONS TO RAPIDLY
DETERIORATE AFTER 06Z AS -FZDZ BRIEFLY DEVELOPS BEFORE TRANSITIONING
TO SNOW. THERE IS A MODERATE TO HIGH PROBABILITY ALL TERMINALS COULD
BE AT OR BELOW AIRPORT MINIMUMS, PARTICULARLY AT KDHT AND KGUY.
CONDITIONS WILL SLOWLY IMPROVE AT KAMA FIRST, FOLLOWED BY KDHT, AND
FINALLY KGUY.
JACKSON
PREV DISCUSSION... /ISSUED 412 PM CST MON FEB 3 2014/
DISCUSSION...
FORECASTS CONCERNING THE POTENTIAL FOR ACCUMULATING SNOWFALL TONIGHT/
TUESDAY REMAIN QUITE COMPLEX. THE WINTER WEATHER ADVISORY HAS BEEN
EXTENDED TO INCLUDE MORE OF THE SOUTHWESTERN AND CENTRAL TEXAS
PANHANDLE...BUT WILL STILL EXCLUDE DEAF SMITH COUNTY. IT IS IMPORTANT
TO CONVEY VARIED IMPACTS WITH THIS EVENT...AS PORTIONS OF THE
SOUTHWESTERN PANHANDLE /INCLUDING AMARILLO/ WILL LIKELY EXPERIENCE
LOW-END ADVISORY ACCUMULATIONS /UP TO 1-2 INCHES/ WHILE THE
NORTHEASTERN TEXAS PANHANDLE WILL SEE HIGH-END ADVISORY ACCUMULATIONS
/3-5 INCHES/.
FORECAST SOUNDINGS SUGGEST INITIAL WARM AIR ADVECTION IN ADVANCE OF
THE APPROACHING STORM SYSTEM MAY RESULT IN RE-NEWED FREEZING DRIZZLE
OR LIGHT SNOW THIS EVENING...BUT THE MAIN IMPACTS FROM SNOW WILL
DEFINITELY FOCUS ON THE 06-18Z TIMEFRAME. THAT IS WHEN A SHARP AND
NEGATIVELY TILTED SHORTWAVE TROUGH WILL EJECT AND PROVIDE VERY DEEP
FORCING FOR ASCENT OVER THE PANHANDLES. THIS SYSTEM...NOW OVER
NORTHWESTERN MEXICO CURRENTLY HAS AN IMPRESSIVE WATER VAPOR
REPRESENTATION...AND THERE ARE CONCERNS THAT IT WILL EMERGE DEEPER
THAN PROGGED BY MOST MODELS. THE SYSTEM IS A MATCH FOR THE LAMBERT
TYPE-B SNOW PATTERN IN WEST TEXAS WHICH TENDS TO RESULT IN SOME OF
OUR HEAVIER SNOWFALLS. HOWEVER...MOST NWP CONTINUES PERSISTENT
DEPICTIONS OF PRECIPITATION SPREADING NORTHEASTWARD OVER THE
CENTRAL/EASTERN PANHANDLE AS JET DYNAMICS AND ASSOCIATED
FRONTOGENETICAL FORCING SPREAD NORTHEAST AND FOCUS OVER THE
NORTHEASTERN TEXAS PANHANDLE/EASTERN OKLAHOMA PANHANDLE. ALL
GUIDANCE...ONCE CORRECTED FOR KNOWN BIASES...IS IN GENERAL AGREEMENT
WITH POTENTIAL SNOW ACCUMULATIONS BETWEEN 2-5 INCHES NORTH OF THE
CANADIAN RIVER...ESPECIALLY OVER THE EASTERN PANHANDLES. THIS
INCLUDES THE CIPS ANALOG AND SREF ENSEMBLE GUIDANCE WHICH ONLY
DEPICTS A 15 PERCENT PROBABILITY OF 4 PLUS INCH ACCUMULATIONS. THIS
GUIDANCE LENDS UNCERTAINTY TO PATTERN RECOGNITION CONCEPTUAL MODELS
WHICH WOULD SUGGEST THE MORE STRINGENT 6 INCH WINTER STORM CRITERIA
COULD BE THREATENED. THIS UNCERTAINTY IS FURTHER EXACERBATED DUE TO
RECENT HIGH-RESOLUTION MODELS WHICH HAVE SHIFTED THE CORRIDOR OF
STRONGEST FORCING/HEAVY SNOW WESTWARD TOWARD THE CENTRAL PANHANDLE.
DUE TO THESE UNCERTAINTIES...WILL MAINTAIN/EXPAND THE CURRENT
ADVISORY BUT WILL SEGMENT IT TO REFLECT THE VARYING ACCUMULATIONS
WITH AN EMPHASIS ON NEAR WINTER STORM IMPACTS IN THE EASTERN OKLAHOMA
PANHANDLE AND THE NORTHEASTERN TEXAS PANHANDLE. IT IS POSSIBLE THAT
LOCALIZED 6 INCH AMOUNTS COULD MATERIALIZE THERE...AND ULTIMATELY
WARRANT A WINTER STORM WARNING UPGRADE.
THERE ARE OTHER TIMEFRAMES OF CONCERN IN THIS FORECAST PERIOD AS
WELL. ANOTHER INVASION OF ARCTIC AIR WILL PUSH SOUTHWARD IN THE WAKE
OF TOMORROW/S SYSTEM. PERIODS OF LIGHT SNOW APPEAR LIKELY WEDNESDAY
AND THURSDAY AS THE ENTRANCE REGION OF AN UPPER JET LINGERS ATOP
LIGHT UPSLOPE LOW LEVEL FLOW. THE NEXT POTENTIAL FOR SIGNIFICANT
WINTER PRECIPITATION MAY OCCUR BY THE WEEKEND AS ANOTHER SHARP UPPER
AIR TROUGH IS PROGGED BY THE LONG RANGE MODELS TO TRANSLATE OVER THE
SOUTHERN PLAINS.
FIRE WEATHER...
ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE NOT EXPECTED
THROUGH THE REST OF THE WEEK. SEVERAL OPPORTUNITIES FOR WETTING
MOISTURE WILL EXIST THROUGH THE UPCOMING WEEK..
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...WINTER WEATHER ADVISORY UNTIL 2 PM CST TUESDAY FOR THE FOLLOWING
ZONES: DALLAM...GRAY...HANSFORD...HEMPHILL...HUTCHINSON...
LIPSCOMB...OCHILTREE...ROBERTS...SHERMAN...WHEELER.
WINTER WEATHER ADVISORY UNTIL NOON CST TUESDAY FOR THE FOLLOWING
ZONES: ARMSTRONG...CARSON...COLLINGSWORTH...DEAF SMITH...
DONLEY...HARTLEY...MOORE...OLDHAM...POTTER...RANDALL.
OK...WINTER WEATHER ADVISORY UNTIL 2 PM CST TUESDAY FOR THE FOLLOWING
ZONES: BEAVER...CIMARRON...TEXAS.
&&
$$
JC/JJ
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1046 PM CST MON FEB 3 2014
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SYNOPSIS...
ISSUED AT 203 PM CST MON FEB 3 2014
QUIET MID-WINTER WX WITH CONTINUED BELOW NORMAL TEMPERATURES.
THE DOMINANT LARGE SCALE FEATURE ACRS THE NRN HEMISPHERE WL BE
THE MASSIVE POSITIVE UPR HEIGHT ANOMALY THAT WL BE SLOWLY
RETROGRADING AWAY FM AK DURING THE NEXT 10 DAYS. THE MAIN
WESTERLIES WL SPLIT AS THEY ENCOUNTER THE HIGH/RIDGE...THEN MERGE
BACK TOGETHER OVER NOAM. THE LCN OF THE FCST AREA WITHIN THE
CONFLUENT ZONE WHERE THE NRN AND SRN STREAMS MERGE BACK TOGETHER
WL RESULT IN FAIRLY TRANQUIL MID-WINTER WX FOR THE AREA.
PCPN SHOULD CONSIST OF JUST A LITTLE LIGHT SNOW OR FLURRIES AT
TIMES AS THE FCST AREA GETS GRAZED BY THE TAIL OF NRN STREAM
SHRTWVS OR THE NRN FRINGE OF SRN STREAM CYCLONES. COLD HIGH
PRESSURE WL BE RIDGING FM NW CANADA...SEWD...BENEATH THE UPR
CONFLUENT ZONE. THAT WL KEEP TEMPS BLO NORMAL THROUGH THE PERIOD.
IF THE MED RANGE MODELS ARE CORRECT IN THEIR HANDLING OF THE UPR
PATTERN...AND THEY ARE ALL SHOWING PRETTY MUCH THE SAME
TRENDS...WE WILL FINALLY GET THE NERN PAC UPR RIDGE SHIFTED FAR
ENOUGH W TO ALLOW TEMPS TO TREND BACK CLOSER TO SEASONAL NORMALS.
BUT THAT PROBABLY WON/T HAPPEN UNTIL BEYOND THE END OF THE PERIOD.
&&
.SHORT TERM...TONIGHT AND TUESDAY
ISSUED AT 203 PM CST MON FEB 3 2014
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW ARCTIC HIGH
PRESSURE CENTERED OVER THE MID-MISSISSIPPI VALLEY TO THE SOUTHERN
GREAT LAKES EARLY THIS AFTERNOON. SHORTWAVE TROUGH OVER NEBRASKA
IS SENDING A RATHER THICK LOOKING AREA OF MID AND HIGH CLOUDS
TOWARDS THE WESTERN GREAT LAKES. MEANWHILE...BAND OF LOW STRATUS
AND FLURRIES ARE MAKING A LITTLE PROGRESS SOUTHEAST ALONG A
SURFACE TROUGH OVER NE MINNESOTA AND FAR WESTERN LAKE SUPERIOR.
THE PINE TREE EFFECT IS BEGINNING TO TAKE SHAPE ACROSS NORTH-
CENTRAL WISCONSIN WHERE TEMPERATURES HAVE REACHED 25 DEGREES AT
LAND O LAKES AND 22 DEGREES AT EAGLE RIVER. WITH THE MAIN FOCUS
FOR PRECIPITATION OCCURRING OVER CENTRAL PLAINS TO THE OHIO
VALLEY...FORECAST CONCERNS ONCE AGAIN REVOLVE AROUND TEMPS AND
CLOUDS.
TONIGHT...SURFACE HIGH PRESSURE WILL SHIFT ACROSS THE EASTERN
GREAT LAKES WHILE A WEAK SURFACE TROUGH SAGS INTO NORTH-CENTRAL TO
WEST-CENTRAL WISCONSIN. LITTLE TO ANY TEMPERATURE ADVECTION ALONG
THIS TROUGH AS WINDS WILL BECOME LIGHT AND VARIABLE ONCE AGAIN.
BUT UNLIKE THE PAST COUPLE NIGHTS...RIGHT ENTRANCE REGION OF A
JETSTREAK OVER SOUTHERN CANADA ALONG WITH WEAK SHORTWAVE ENERGY
WILL PROVIDE AMPLE MID AND UPPER LEVEL CLOUDS. WITH THE SOLID
NATURE TO THEIR APPEARANCE...THINK A REPEAT PERFORMANCE OF TEMPS
THE PAST COUPLE NIGHTS IS UNLIKELY. LOWS ACROSS CENTRAL AND
WESTERN NEBRASKA AND SOUTH DAKOTA WERE MAINLY IN THE SINGLE DIGITS
ABOVE ZERO AND A FEW DEGREES BELOW ZERO. SO WILL HAVE LOWS IN THAT
SIMILAR RANGE TONIGHT...WHICH IS SIMILAR TO THE BCALLBLEND.
TUESDAY...SUBTLE REINFORCING ARCTIC COLD FRONT WILL STALL OVER
NORTHWEST WISCONSIN WHILE MID AND HIGH CLOUDS LINGER OVERHEAD
DURING THE MORNING. AREA OF LOW PRESSURE MOVING WITHIN THE
SOUTHERN STREAM REMAINS PROJECTED TO SLIDE TO OUR SOUTH. NORTHERN
PERIPHERY OF THE CIRRUS SHIELD FROM THIS SYSTEM WILL PROVIDE A
PARTLY SUNNY TO MOSTLY CLOUDY DAY ACROSS THE FORECAST AREA.
NORTHERN WISCONSIN HAS A BETTER CHANCE OF MORE SUN AS SOME OF THE
MID AND UPPER MOISTURE PEELS OUT DURING THE AFTERNOON. 925MB TEMPS
COOL OFF SOME BEHIND THE FRONT OVER N-C WISCONSIN...SO WILL GO
WITH HIGH TEMPS IN THE MIDDLE TEENS THERE...AND THE LOWER 20S OVER
E-C WISCONSIN.
.LONG TERM...TUESDAY NIGHT THROUGH MONDAY
ISSUED AT 203 PM CST MON FEB 3 2014
COLD BUT QUIET PATTERN WL CONTINUE. THE SRN 1/3 OF THE FCST AREA
COULD GET GRAZED BY THE SNOW SHIELD FM SYSTEM TRACKING THROUGH THE
OHIO VALLEY TUE NGT INTO WED. THE NRN EDGE OF THE PCPN STILL IN
DOUBT...SO DIDN/T TAKE POPS BEYOND CHC CATEGORY. EVEN IF PCPN
MAKES IT INTO THE AREA...PROBABLY WOULD NOT GET MORE THAN A
DUSTING. SITN WOULD NORMALLY BE A PRETTY GOOD SETUP FOR LAKE-
EFFECT OFF LAKE MICHIGAN. BUT WITH THE LAKE PROBABLY OVER 50 PCT
ICE COVERED...IT SEEMS UNLIKELY THE LAKE-EFFECT WOULD AMOUNT TO
ANYTHING MORE THAN JUST FLURRIES OR SCT LGT SHSN. THE NEXT SRN
STREAM SYSTEM WON/T HEAD EWD FM THE PLAINS UNTIL THE WEEKEND...
AND IT LOOKS SIMILAR TO THE TUE NGT SYSTEM.
TEMPS WL PROBABLY AVERAGE 10-18 F DEG BLO NORMAL FOR THE PERIOD.
THAT IS A SIGNIFICANT DEPARTURE FM NORMAL...BUT IT PROBABLY WON/T
SEEM EXCEPTIONALLY COLD AFTER WHAT WE HAD LAST MONTH. ALSO...WE/VE
NOW GAINED BACK ABOUT 6 WEEKS WORTH OF SUN ANGLE...AND WE ARE
STARTING TO SEE THE EFFECTS OF THAT ON MAX TEMPS DURING THE DAY.
THE WARMEST TEMPS IN THE FCST AREA THIS AFTN ARE UP IN VILAS
COUNTY...DESPITE THE FACT THAT THEY FELL TO 20 BELOW TO 25 BELOW
ZERO THIS MORNING. STRANGE THOUGH IT MAY SEEM...THIS IS ACTUALLY A
SIGN WE ARE HEADING TOWARD SPRING.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1043 PM CST MON FEB 3 2014
DISTURBANCES MOVING THROUGH FLOW OVER NORTHERN PLAINS AND A MORE
AMPLIFIED LOW PRESSURE SYSTEM EXPECTED TO PASS WELL TO OUR
SOUTH...WILL BRING PERIODS OF MAINLY MID AND HIGH CLOUDS OVER THE
STATE THROUGH MUCH OF THE TAF PERIOD.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS.......SKOWRONSKI
SHORT TERM.....MPC
LONG TERM......SKOWRONSKI
AVIATION.......TE
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
820 PM MST WED FEB 5 2014
.SYNOPSIS...
A WEATHER DISTURBANCE WILL BRING CONSIDERABLE CLOUDINESS AND
ISOLATED SHOWERS THROUGH TONIGHT...PARTICULARLY ACROSS THE
HIGHER TERRAIN OF SOUTH-CENTRAL ARIZONA. A STRONGER WEATHER
DISTURBANCE WILL BRING A SLIGHT CHANCE OF SHOWERS THURSDAY NIGHT AND
FRIDAY...WITH A BETTER CHANCE OVER THE HIGHER TERRAIN OF
SOUTH-CENTRAL ARIZONA. ANTICIPATE BELOW NORMAL TEMPERATURES THROUGH
FRIDAY. OVER THE WEEKEND...A WARMING TREND WILL BEGIN AS HIGH
PRESSURE MOVES INTO THE WESTERN STATES.
&&
.DISCUSSION...
THIS EVENING WEATHER BALLOON SOUNDINGS SHOWED ALL 500/300 MB FALLS
WERE EAST OF PHOENIX...CENTERED AROUND EL PASO...SIGNALING THE
SHORTWAVE HAS PASSED. REGIONAL UPPER AIR DATA ALSO SHOWED 700/500 MB
WARM AIR ADVECTION TRENDING TOWARD SOUTHWEST AZ THIS EVENING FROM
SOUTHERN CA. IN OTHER WORDS...THE AIRMASS OVERNIGHT IS QUICKLY
STABILIZING WITH AN END TO SHOWER POTENTIAL OVER OUR FORECAST AREA
FROM PHOENIX TO GLOBE/MIAMI. SATELLITE IMAGERY ALSO SHOWED CLOUDS
DISSIPATING RATHER QUICKLY AT 03Z ACROSS SOUTH CENTRAL AZ. SKIES
ACROSS SOUTHEAST CA AND SOUTHWEST AZ WERE CLEAR AT 03Z.
HOWEVER...BALLOON DATA SHOWED THE LOW LEVEL AIRMASS BELOW 800 MB...
OR BELOW 7 THSD FT...WAS RELATIVELY MOIST WITH RESPECT TO THE
CURRENT AIRMASS OVER THE REGION. FOR EXAMPLE...800 MB DEWPOINTS FROM
SAN DIEGO/NORTHERN BAJA TO PHOENIX WERE RUNNING FROM MINUS 2-4 C...
WHILE 700 MB TEMPS ARE TO REMAIN NEAR THE MINUS 6 DEG C RANGE
THROUGH THURSDAY. THEREFORE THE LOW LEVEL AIRMASS HAS BECOME
SUFFICIENTLY MOIST...WITH LOW LEVEL WINDS EXPECTED TO BACK ON
THURSDAY...AHEAD OF THE NEXT ANTICIPATED COLDER AND DYNAMICALLY
STRONGER DISTURBANCE. THIS NEXT DISTURBANCE WILL HAVE A BETTER
CHANCE TO GENERATE MEASURABLE PRECIP AS OPPOSED TO THE DISTURBANCE
THAT PASSED THIS AFTERNOON OR WED AFTERNOON. AND...RECENT PRECIP
WATER IMAGERY ALSO SHOWED A STEADY HOUR BY HOUR EASTWARD SHIFT IN
PACIFIC MOISTURE TOWARD THE WEST COAST AHEAD OF THE APPROACHING
SHORTWAVE.
THEREFORE...BASED ON THE COLDER AND DYNAMICALLY STRONGER SHORTWAVE
EXPECTED TO ARRIVE LATE THURSDAY AFTERNOON AND NIGHT...WE FEEL THERE
IS A BETTER CHANCE OF SHOWERS SPREADING WEST TO EAST. THE BEST
CHANCE OF SHOWERS WILL OCCUR THURSDAY NIGHT OVER SOUTH CENTRAL AZ
FROM WICKENBURG AND PHOENIX EAST INTO MOUNTAINOUS SOUTHERN GILA
COUNTY ZONE 24. SNOW LEVELS THURSDAY NIGHT WILL REMAIN FAIRLY
HIGH...FALLING TO BETWEEN 5000 AND 5500 FEET BY FRIDAY MORNING.
WEATHER UPDATES INCREASING THE CHANCE OF SHOWERS FOR THE LATE
THURSDAY AFTERNOON AND THURSDAY NIGHT...MAINLY ACROSS SOUTH CENTRAL
AZ WERE SENT EARLIER. NO FURTHER UPDATES EXPECTED.
PORTIONS OF PREVIOUS DISCUSSION...310 PM MST...
A SHORT-WAVE TROUGH CONTINUED TO SLIDE THROUGH EASTERN AZ. CLOUD
SHIELD ASSOCIATED WITH THE MORNING VIRGA/SPRINKLES HAS MOVED EAST OF
THE AREA. THIS CREATED AN AREA OF CLEARING ACROSS SOUTH-CENTRAL AZ
THAT QUICKLY FILLED IN THIS AFTERNOON. CONDITIONS REMAIN RELATIVELY
STABLE IN THIS AREA...THOUGH MODEST FORCING FOR UVM HAS DEVELOPED
AHEAD OF AN ELONGATED VORT MAX BEHIND THE TROUGH AXIS ALONG THE CO
RIVER VALLEY. LATEST HRRR SUGGESTS THAT ISOLATED SHOWERS STILL HAVE
THE POTENTIAL TO DEVELOP IN THIS REGION THROUGH THE REMAINDER OF THE
AFTERNOON. CLEARING TREND TO FOLLOW FOR THIS EVENING.
FAST ON THE HEELS OF THE AFOREMENTIONED TROUGH WILL BE ANOTHER
PACIFIC TROUGH FOR THURSDAY/THURSDAY NIGHT. MODELS CONTINUE TO TREND
FASTER WITH THIS SYSTEM AND THE SUITE OF LOCAL HI-RES WRFS SUGGEST
THAT A THREAT OF SHOWERS MAY AGAIN DEVELOP AS EARLY AS THURSDAY LATE
AFTERNOON. HOWEVER...CONSENSUS AMONG THE MODELS POINT TO NORTHERN AZ
FOR THE HIGHEST PRECIP CHANCES/AMOUNTS CONTINUING INTO FRIDAY
MORNING. SUBSIDENCE AND SHARP HEIGHT RISES ARE EXPECTED TO
PREDOMINATE BY FRIDAY AFTERNOON BEHIND THE TROUGH AXIS.
&&
.PREVIOUS DISCUSSION...
SATURDAY THROUGH TUESDAY...
HIGH PRESSURE BUILDS IN OVER THE WEEKEND FOR A WARMING TREND. HIGHS
SHOULD CLIMB ABOVE NORMAL SUNDAY...INTO THE 70S ACROSS THE LOWER
DESERTS...AND STAY THERE THROUGH TUESDAY DESPITE A PASSING SHORT
WAVE MONDAY. WITH CLEARER SKIES AND DRIER AIR...LOW TEMPS WILL BE AT
THEIR COOLEST THIS WEEKEND BEFORE INCREASING AGAIN.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA...INCLUDING KPHX...KIWA...AND KSDL...AND
SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA INCLUDING KIPL AND KBLH...
THROUGH 18Z THU...SCT CLDS NEAR 10 THSD MSL. LIGHT WIND UNDER 5
KNOTS. FROM 18Z THU TO 03Z FRI...PACIFIC DISTURBANCE APPROACHING THE
AREA. INCREASING CLOUDS BECOMING 12 THSD BKN AGL BY 20Z THU...
ISOLATED R SHWRS AFT 00Z FRI.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
FRIDAY THROUGH TUESDAY...
FAST MOVING TROUGH WILL SWEEP THROUGH THE AREA ON FRIDAY...NOT AS
INTENSE OF A SYSTEM AS FIRST THOUGHT A FEW DAYS AGO...BUT
NONETHELESS IT WILL HAVE SOME MOISTURE TO WORK WITH. COULD SEE
SHOWERS ACROSS PORTIONS OF THE AREA...POSSIBLY EVEN ACROSS THE
DESERTS OF THE PHOENIX AREA. ANY RAIN THAT OCCURS WOULD BE
LIGHT...LESS THAN A TENTH OF AN INCH TOTAL. FOLLOWING THE
TROUGH...HUMIDITIES WILL REMAIN ELEVATED AS STRONG DRY ADVECTION
THAT WAS FORECAST A FEW DAYS AGO NOW APPEARS UNLIKELY. ELEVATED
HUMIDITIES WILL PERSIST INTO EARLY NEXT WEEK. AS FOR WINDS...NOTHING
TOO STRONG EVEN WITH THE LOW ON FRIDAY...TYPICAL DIURNAL
DRAINAGE/UPSLOPE PATTERNS EXPECTED THROUGH TUESDAY.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...VASQUEZ/HIRSCH
PREVIOUS TO PREVIOUS DISCUSSION...AJ
AVIATION...MEYERS
FIRE WEATHER...LEINS
AREA FORECAST DISCUSSION...UPDATED
NWS RENO NV
817 PM PST WED FEB 5 2014
.UPDATE...
NOT PLANNING ON ANY CHANGES THIS EVENING. THE 00Z NAM AND LATEST
3KM HRRR SUGGEST TRACK OF SHORTWAVE FURTHER SOUTH LATE TONIGHT AND
THURSDAY WITH THE GFS MAINTAINING A GENERALLY SOUTH OF HIGHWAY 50
LINE FOR THE BULK OF PRECIPITATION. SO AMOUNTS FOR THE TAHOE BASIN
MAY BE HEAVIEST ON THE SOUTH END TOWARD ALPINE COUNTY. WILL WAIT
FOR THE 00Z ECMWF TO DETERMINE IF THIS MORE SOUTHERN TRACK IS
REASONABLE AND LET THE NIGHT SHIFT MAKE NECESSARY ADJUSTMENTS
WITH THE MORNING FORECAST. MODELS ARE SHOWING A DEFINITE DECREASE
IN COVERAGE BY LATE AFTERNOON. SO THE ADVISORIES ARE PROBABLY TOO
LONG ALTHOUGH SLICK ROADS WILL PERSIST INTO THURSDAY NIGHT WHERE
NOT TREATED. AS COLD AS THINGS ARE, ANY SNOW THAT FALLS WILL
RESULT IN HAZARDOUS ROADS DURING THE THURSDAY MORNING COMMUTE
INCLUDING LOWER VALLEYS. FOR LOWER VALLEYS, CONFIDENCE IN AT LEAST
AN INCH OF SNOW IS ONLY LOW-MEDIUM FOR THE RENO AREA AND NORTH
VALLEYS WITH MEDIUM CONFIDENCE IN THE CARSON CITY-DAYTON AREA OF
HIGHWAY 50, AND HIGH SOUTH OF CARSON CITY ALONG THE HIGHWAY 395
CORRIDOR.
QUICK LOOK BEYOND THURSDAY STILL SUGGESTS A VERY AND WET WARM
SYSTEM WITH GUSTY WINDS. SO AS FAR AS THE 00Z GFS/NAM
DETERMINISTIC RUNS, THE FORECAST IS ON TRACK WITH THE TYPICAL
UNCERTAINTY IN SNOW LEVELS. HOHMANN
&&
.PREVIOUS DISCUSSION... /ISSUED 313 PM PST WED FEB 5 2014/
SYNOPSIS...
INCREASING MOISTURE AND A WEAK DISTURBANCE MOVING OVER THE SIERRA
AND WESTERN NEVADA WILL BRING SOME SNOW THURSDAY. DEEPER PACIFIC
MOISTURE WILL BRING MILDER TEMPERATURES AND PERIODS OF RAIN AND
SNOW TO THE REGION THIS WEEKEND ALONG WITH GUSTY WINDS. DRIER
WEATHER IS EXPECTED NEXT WEEK.
SHORT TERM...
ACTIVE WEATHER PATTERN FOR THE NEXT FEW DAYS BEGINNING TOMORROW.
THE MODELS CONTINUE TO SHOW DISCREPANCIES BETWEEN ONE ANOTHER AS
WELL AS RUN TO RUN EVEN FOR TOMORROW. THERE IS ENOUGH AGREEMENT
THAT WE FEEL CONFIDENT THERE WILL BE SNOW IN THE SIERRA AND
POSSIBLY WESTERN NEVADA TOMORROW. ALSO, THE STORM SLATED FOR THE
WEEKEND IS TRENDING WETTER ON THE MODELS AS WELL.
EXPECT INCREASING CLOUDS TONIGHT AHEAD OF A WEAK PACIFIC SYSTEM
FOR TOMORROW. THE TRACK IS THE BIGGEST HEADACHE THIS AFTERNOON AS
THE GFS IS THE FURTHEST SOUTH AND THE EC THE FURTHEST NORTH. HAVE
USED THE SREF WHICH IS IN BETWEEN AND STILL SHOWS A DECENT CHANCE
OF SNOW FROM I-80 SOUTH FOR TOMORROW. SNOW SHOULD BEGIN AROUND 12Z
IN THE SIERRA FOR THE TAHOE BASIN SOUTH TO MONO COUNTY AND
CONTINUE THROUGH THE AFTERNOON. SOME PERIODS OF LIGHT SNOW WILL
ALSO OCCUR IN WRN NEVADA DURING THE LATE MORNING AND AFTERNOON
SOUTH OF I-80 WITH LIGHTER SHOWERS POSSIBLE NORTH. MODELS AGREE ON
QPF AROUND 1/2 INCH IN THE SIERRA WITH SNOW RATIOS OF 12-15:1, SO
HOISTED A LOW-MODERATE ADVISORY WITH A FEW INCHES AROUND 6000 FEET
AND UP TO 10 INCHES ABOVE 7,000. AMOUNTS IN WRN NEVADA WILL BE
LESS THAN 2 INCHES, AND WITH THE SNOW BEING LIGHT, EXPECT LITTLE
IMPACT TO ROADS BELOW 5,000 FEET EVEN THOUGH SNOW LEVELS WILL BE
NEAR THE VALLEY FLOORS.
SNOW TO END EARLY THURSDAY EVENING WITH A BRIEF BREAK BEFORE THE
NEXT SYSTEM MOVES IN FRIDAY AFTERNOON. THIS NEXT SYSTEM HAS A GOOD
SUBTROPICAL MOISTURE TAP ON ALL THE MODELS WITH PW APPROACHING 1.5
INCHES ALONG THE COAST BY FRIDAY AFTERNOON. WHILE THE JET IS
PROGGED TO BE TO THE NORTH, AND ITS FORCING WOULD NOT BE FAVORABLE,
A STRONG WARM FRONT WILL MOVE THROUGH. ITS ISENTROPIC LIFT AND
STRONG SW UPSLOPE FLOW WILL PROVIDE GOOD FORCING FOR THE SIERRA.
SNOW LEVELS WILL BE TRICKY INTO FRIDAY NIGHT AND POSSIBLY START
OUT BELOW 5000 FEET BEFORE RISING OVERNIGHT. THE GFS KEEPS SNOW
LEVELS LOWER LONGER WHILE THE NAM RAISES THEM FASTER. IN ADDITION,
STRONG WINDS ARE POSSIBLE NEAR AND EAST OF HIGHWAY 395 WITH THIS
SYSTEM. THE NAM IS STRONGER WITH THE WINDS AS WELL WITH MORE
SHADOWING INTO WESTERN NEVADA. WITH LACK OF A SURFACE HIGH OVER
THE GREAT BASIN AND NEAR NORMAL HIGHS FRIDAY AFTERNOON, I AM
LEANING TOWARD THE NAM IDEAS. THE LACK OF A SURFACE HIGH WILL
LIMIT ANY COLD AIR DAMMING AND ALSO RESULT AND A MORE FAVORABLE
PROFILE FOR WINDS.
WHILE RAIN AND SNOW WILL OCCUR IN THE SIERRA, THE WARMER SOLUTIONS
WILL KEEP MOST ACCUMULATING SNOW ABOVE 7000 FEET SO WILL HOLD OFF
ON ANY WATCHES AT THIS TIME. AS FOR WINDS, THE BEST POTENTIAL FOR
STRONG WINDS IS ALONG THE SIERRA FRONT INTO MONO COUNTY. WHILE THE
INCREASING WINDS ALOFT ON THE NAM UPSTREAM FAVOR TRAPPED LEE
WAVES, 700 MB WINDS OF 60-70 KTS WOULD BE STRONG ENOUGH FOR SOME
GUSTS OVER 60 MPH. ISSUED HIGH WIND WATCH FOR THOSE AREAS AS I AM
CONFIDENT WE WILL SEE AT LEAST ADVISORY LEVEL WINDS. ELSEWHERE,
IT WILL BE WINDY AS WELL BUT ONLY ADVISORY LEVEL WINDS LOOK TO
OCCUR AND WILL HANDLE THAT CLOSER TO THE EVENT. ONE OTHER THING TO
MENTION IS THAT EVEN IF A BIT MORE SPILLOVER OCCURS THAN EXPECTED,
SFC GRADIENT WILL ALSO BE SUPPORTIVE ENOUGH FOR GUSTY WINDS
ACCOMPANIED BY THE RAIN AND/OR SNOW.
A BRIEFING ON THE SERIES OF STORMS WHICH SUMMARIZES THIS
INFORMATION CAN BE FOUND ON OUR WEB PAGE AND YOU TUBE CHANNEL.
WALLMANN
LONG TERM...SATURDAY THROUGH WEDNESDAY...
FOR SATURDAY THROUGH EARLY MONDAY MORNING ATTENTION TURNS TO A
SUBTROPICAL MOISTURE PLUME EXTENDING FROM HAWAII INTO THE WEST
COAST. A MODEST PLUME OF ABOUT 1.25 INCHES WILL EXTEND OVER THE BAY
AREA BEGINNING EARLY SATURDAY AND PERSISTS UNTIL LATE SUNDAY INTO
EARLY MONDAY MORNING. THIS IS SHAPING OUT TO BE ANOTHER WARM SYSTEM
WITH AMPLE MOISTURE BUT WILL FEATURE HIGH SNOW LEVELS THAT WILL
RAPIDLY INCREASE ON SATURDAY TO BETWEEN ABOUT 7,000-8,000 FEET.
FORCING WILL ALSO BE AN ISSUE WITH THIS SYSTEM WITH JET DYNAMICS
REMAINING NORTH ACROSS OREGON AND STRONG FRONTOGENESIS FORCING
REMAINING ABSENT. MAIN MECHANISM WILL BE OROGRAPHIC LIFT ACROSS THE
SIERRA AND MODEST ISENTROPIC LIFT. THIS SHOULD YIELD THE HIGHEST
PRECIPITATION AMOUNTS ON THE WINDWARD SLOPES OF THE SIERRA AND ALONG
THE CREST. STILL COULD SEE SOME HEALTHY LIQUID EQUIVALENT PRECIP
ALONG THE CREST WITH MODELS DEPICTING GENERALLY BETWEEN 2-3 INCHES
OF LIQUID FOR A 48 HOUR PERIOD FROM SATURDAY INTO EARLY MONDAY
MORNING. THIS COULD YIELD OVER 2 FEET OF SNOWFALL FOR HIGHER SIERRA
TERRAIN WITH MAINLY A RAIN EVENT FOR LOWER ELEVATIONS. SNOWFALL
AMOUNTS BELOW 8,000 FEET IS LOW CONFIDENCE DUE TO UNCERTAINTIES WITH
SNOW LEVEL PLACEMENT AT THIS POINT.
RECENT RUNS CONCENTRATE THE BULK OF THE MOISTURE ACROSS FROM THE
TAHOE BASIN NORTH INTO LASSEN COUNTY WITH LESSER AMOUNTS ACROSS MONO
COUNTY. GENERALLY EXPECTING ABOUT 1-1.5 INCHES OF LIQUID EQUIVALENT
ACROSS THE CREST IN MONO COUNTY. EXPECT MUCH OF WESTERN NEVADA TO BE
SHADOWED THROUGH THE WEEKEND WITH MAINLY INTERMITTENT SHOWERS BLOWING
ACROSS THE SIERRA WITH STRONG AND GUSTY WINDS PERSISTING THROUGH
SATURDAY. EXPECTING THE BEST CHANCE OF SPILLOVER PRECIPITATION TO
OCCUR SUNDAY NIGHT INTO EARLY MONDAY MORNING WHEN A SHORTWAVE TROUGH
CROSSES THE REGION. SNOW LEVEL WILL THEN FALL AGAIN NEAR 6,000 FEET
LATE SUNDAY. ACROSS WESTERN NEVADA, COULD SEE RAINFALL AMOUNTS NEAR
AN INCH IN THE FOOTHILLS WITH AROUND ONE HALF INCH ALONG THE SIERRA
FRONT AND A THIRD OF AN INCH ACROSS THE BASIN AND RANGE AREAS
THROUGH EARLY MONDAY MORNING. FUENTES
THE WEATHER IS EXPECTED TO SETTLE DOWN FOR THE FIRST HALF OF THE
WORK WEEK AS THE MOISTURE FEED DISSIPATES OVER CALIFORNIA AND
NEVADA AND A NEW FEED DIRECTS ITSELF TOWARDS THE PACIFIC
NORTHWEST.
MONDAY, THE UPPER DISTURBANCE ON THE TAIL END OF THIS WEEKEND`S
MOISTURE TAP WILL PUSH OFF INTO EASTERN NEVADA AND UTAH. THIS WILL
MEAN SHOWERS TAPERING OFF DURING THE DAY WITH SNOW LEVELS FALLING TO
BETWEEN 5000-6500 FEET (BUT LITTLE OR NO ADDITIONAL SNOWFALL).
TUESDAY AND WEDNESDAY, NORTHERN CALIFORNIA AND NEVADA WILL BE ON THE
SOUTHERN PERIPHERY OF THE MAIN STORM TRACK AS AN UPPER TROUGH DIGS
OVER THE NORTH CENTRAL PACIFIC AND PUMPS UP A RIDGE OVER THE REGION.
MODELS INDICATE PLENTY OF MID-HIGH LEVEL MOISTURE SO I HAVE LEFT
MOSTLY CLOUDY SKIES IN THE FORECAST. PRECIPITATION-WISE, THERE IS
SOME UNCERTAINTY AS TO WHETHER OR NOT WE COULD SQUEEZE OUT PERIODIC
LIGHT SHOWERS NORTH OF INTERSTATE 80 DEPENDING ON HOW THE FAST FLOW
TO OUR NORTH BUCKLES WITH MINOR DISTURBANCES MOVING OVER THE RIDGE.
THEREFORE, I HAVE LEFT LOW POP IN BUT TRIMMED IT BACK TO AREAS
GENERALLY NORTH OF INTERSTATE 80. SNYDER
AVIATION...
CIRRUS CLOUDS AHEAD OF AN UPPER DISTURBANCE ABOUT 600 MILES WEST
OF KSFO HAVE SPREAD INTO NORTHERN CALIFORNIA. THIS DISTURBANCE
WILL MOVE INTO THE SIERRA AND WESTERN NEVADA BETWEEN 09Z-15Z
THURSDAY, BRINGING -SN/-SHSN AND WIDESPREAD TERRAIN OBSCURATION
(ESPECIALLY SIERRA AND WESTERN NV PEAKS) TO THE AREA THROUGH
THURSDAY AFTERNOON.
AS FAR AS SIERRA TERMINAL IMPACTS, IFR/LIFR CIGS/VSBYS EXPECTED FOR
MOST OF THURSDAY IN NORTHERN SIERRA WITH SEVERAL INCHES OF SNOWFALL
ON UNTREATED SURFACES. FOR KMMH, -SHSN POSSIBLE IN THE MORNING
THURSDAY BUT THE HEAVIEST SNOWFALL SHOULD BE IN THE 19Z/11 AM TO
00Z/4 PM TIME FRAME.
FOR WESTERN NEVADA TERMINALS (INCLUDING KRNO/KCXP) THURSDAY, A
PERIOD OF -SN LIKELY IN THE MORNING FOLLOWED BY SNOW SHOWERS IN THE
AFTERNOON. CIGS/VSBY LOOK GENERALLY LOWEST IN THE MORNING, WITH MORE
INTERMITTENT LOWERING IN -SHSN IN THE AFTERNOON. GIVEN THAT SNOW IS
EXPECTED TO START BY AROUND SUNRISE, UNTREATED PAVEMENT AT TERMINALS
COULD SEE A LIGHT ACCUMULATION (MOST LIKELY LESS THAN ONE INCH).
CONFIDENCE IN A LIGHT ACCUMULATION IS AROUND 40%. AFTER 18-19Z,
GROUND TEMPERATURES SHOULD COME UP ENOUGH TO MELT ROAD/RUNWAY
SURFACES. SNYDER
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...HIGH WIND WATCH FROM FRIDAY EVENING THROUGH SATURDAY MORNING
NVZ003.
WINTER WEATHER ADVISORY FROM 4 AM TO 10 PM PST THURSDAY NVZ002.
CA...WINTER WEATHER ADVISORY FROM 4 AM TO 10 PM PST THURSDAY CAZ073.
HIGH WIND WATCH FROM FRIDAY EVENING THROUGH SATURDAY MORNING
CAZ073.
WINTER WEATHER ADVISORY FROM 4 AM TO 10 PM PST THURSDAY CAZ072.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
953 PM MST WED FEB 5 2014
.UPDATE...
ISSUED AT 952 PM MST WED FEB 5 2014
SNOW HAS BEEN SLOW TO GET STARTED THIS EVENING. MOST PRECIPITATION
WAS TO OUR NORTH ALONG THE 700 MB BAROCLINIC BAND THAT STRETCHED
FROM SRN ID ACROSS SRN WY. BUT...RABBIT EARS SNOTEL RECORDED LIGHT
SNOW IN THE PAST HOUR...AND MT WERNER OBS SHOWING LOWERED CLOUDS AND
VISIBILITY. STILL EXPECT SNOW TO EXPAND INTO THE NORTHERN AND CENTRAL
MOUNTAINS OVERNIGHT IN THE WAKE OF A SHORTWAVE NOW JUST BRUSHING OUR
NRN BORDER. HIGH RESOLUTION HRRR MODELS SHOWING THE INITIAL SNOW TO
BE MOSTLY LIGHT...HOWEVER. FORECAST GRIDS UPDATED EARLIER TO REFLECT
THIS SLOWER START.
&&
.SHORT TERM...(TONIGHT THROUGH THURSDAY NIGHT)
ISSUED AT 317 PM MST WED FEB 5 2014
YESTERDAYS COLD FRONT HAS RETREATED TO CLOSE TO THE WYOMING BORDER
THIS AFTERNOON. MOST VALLEY TEMPERATURES STILL LAG TUESDAY
AFTERNOON INDICATING INVERSIONS ARE IN PLACE. THIS FORECAST AREA
REMAINS SANDWICHED BETWEEN A TROUGH PROGRESSING THROUGH THE DESERT
SW AND AN ELONGATED W-E TROUGH ALONG THE NORTHERN TIER STATES WITH
BOTH FEATURES SHIFTING EAST BY THURSDAY.
TONIGHT...MOISTURE IS STILL PROGGED TO INCREASE ESPECIALLY ACROSS
THE NORTHERN ZONES. LACK OF DYNAMICAL SUPPORT AND WEAK MID-LEVEL
WARM ADVECTION WILL LIMIT MOST SNOWFALL TO THE NORTHERN AND
CENTRAL COLORADO MOUNTAINS.
THURSDAY-THURSDAY NIGHT...THE TAIL OF THE SHEARED TROUGH RAKES THE
SOUTHERN ZONES BRINGING LIGHT SHOWERS TO THE SAN JUANS ESPECIALLY
TO THE HILLS ABOVE PAGOSA SPRINGS. OTHERWISE OROGRAPHIC WNW FLOW
WILL CONTINUE TO PRODUCE WIDESPREAD BUT LIGHT MOUNTAIN SNOWFALL.
VALLEY INVERSIONS WILL BEGIN TO BE ERODE AS SNOW SHOWERS/VIRGA
AND BRISK MTN WINDS WORK ON THE TOP OF INVERSIONS. SIGNIFICANT
OVERRUNNING SNOWFALL NEEDS TO BE WATCHED FOR CRAIG-STEAMBOAT AREA.
COORDINATED WITH THE PUEBLO OFFICE TO CARRY SUB-ADVISORY SNOW
AMOUNTS IN THE SOUTHERN MTNS THROUGH THURSDAY NIGHT. THE NE UTAH
UINTA MTNS TOO WERE EXPECTED TO GET ONLY LIGHT ACCUMULATIONS
THROUGH THESE PERIODS AS THE SURFACE FRONT REMAINS NORTH OF THAT
ZONE AND WEST OROGRAPHICS ARE UNFAVORABLE THERE.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 317 PM MST WED FEB 5 2014
12Z MODELS BRING A TROUGH THROUGH THE GREAT BASIN OVERNIGHT INTO
FRIDAY AND IS EXPECTED TO BRING A WAVE OF ENERGY INTO WESTERN CO
ON FRIDAY MORNING. THE REAPPEARANCE OF THE UPPER LEVEL JET ON
FRIDAY WILL ALLOW WINDS TO INCREASE WITH THE PROBABILITY OF SNOW
AND ALLOW FOR GOOD DIVERGENCE ALOFT. GFS HAS A 110KT TO 120KT JET
MAX MOVING INTO THE REGION ON SATURDAY...WHICH IS WHEN THE MOST
WIDESPREAD AND EFFICIENT SNOWFALL IS EXPECTED WITH THIS NEXT
SERIES OF SYSTEMS. HOWEVER...SINCE MODELS HAVE NOT BEEN
CONSISTENT...HAVE KEPT FROM ISSUING ANY NEW HAZARDS THIS AFTERNOON
FOR THE LONGER RANGE. IT DOES APPEAR THAT ADVISORIES WILL BE
NEEDED FOR THE SAN JUANS AND POTENTIALLY ALONG PARTS OF THE I-70
CORRIDOR FROM ABOUT GLENWOOD SPRINGS AND EAST FOR THE WEEKEND.
LOOKING FOR SOME BETTER CONSISTENCIES BETWEEN MODEL RUNS BEFORE
MAKING THAT DECISION.
SNOW LEVEL WILL RISE THROUGHOUT THE AFTERNOON ON SATURDAY AS THE
JET STREAM LIFTS NORTH AND BEGINS TO MIX OUT THE COLD AIR POOL
WHICH HAS BEEN IN PLACE THE LAST FEW DAYS SINCE THE LAST SNOWFALL. MOS
GUIDANCE IS SHOWING UNSEASONABLY WARM TEMPS ON SUNDAY AND MONDAY.
KEPT TEMPS IN THE VALLEYS SLIGHTLY COOLER THAN MOS GUIDANCE
CONSIDERING THE SNOW COVER BUT TEMPERATURES WILL LIKELY RISE ABOVE
FREEZING IN CENTRAL COLORADO VALLEYS IN THE AFTERNOON AND EARLY
EVENING...WHICH MAY RESULT IN A RAIN/SNOW MIX IF PRECIPITATION
ACCOMPANIES THIS WARM AIR ADVECTION.
IF TRAVELING ACROSS THE I-70 CORRIDOR THIS WEEKEND...BE PREPARED FOR
POTENTIAL WINTER WEATHER. LONG RANGE MODELS SUGGEST THAT SNOW
WILL CONTINUE OVER VAIL PASS FRIDAY THROUGH MIDWEEK...THOUGH THE
SNOW INTENSITY WILL VARY BASED ON THE TIMING OF THE SHORTWAVE
DISTURBANCES. PWAT INCREASES SATURDAY THROUGH MONDAY ACROSS THE
REGION. CURRENT MODELS SHOW A POTENTIALLY WIDESPREAD...BUT FAST
MOVING...PRECIPITATION EVENT BEGINNING ON MONDAY MORNING. BOTH
THE GFS AND EC INDICATE THIS SYSTEM MOVING IN VERY EARLY MONDAY
MORNING AND CONTINUING THROUGHOUT THE DAY.
THIS ACTIVE ZONAL PATTERN CONTINUES THROUGH MID NEXT WEEK...THEN
THE LONG RANGE GFS AND EC SUGGEST DEVELOPMENT OF A WEAK RIDGE OVER
THE WEST COAST. THIS RIDGING WOULD PUT THE AREA BACK INTO
NORTHWEST FLOW AND KEEP THE NORTHCENTRAL MTNS IN THE MOST
FAVORABLE LOCATION FOR PRECIPITATION MID FEBRUARY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 952 PM MST WED FEB 5 2014
WESTERLY FLOW ALOFT WILL PREVAIL THROUGH THU EVENING. MOISTURE IN
THE FLOW WILL RESULT IN OCCASIONAL -SN ACROSS THE NORTHERN AND
CENTRAL MTNS BY 12Z THU...AND THE SOUTHERN MTNS BY 18Z. LOWERING CIGS
WILL RESULT IN MTN TOPS BECOMING OBSCURED. VFR WILL BE THE
PREVAILING CONDITIONS AT THE VALLEY TAF SITES WITH SOME PERIODS MVFR
CIGS/VSBY IN -SN AT KRIL/KEGE AFTER 12Z. LONGER PERIODS OF MVFR IN
-SN WITH POSSIBLE IFR VSBY AT TIMES ARE EXPECTED AT KASE AFTER
09Z...AND AT KTEX AFTER 15Z.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER STORM WARNING UNTIL 6 PM MST SATURDAY
COZ004-009-010-012-013.
WINTER STORM WARNING UNTIL 6 PM MST SATURDAY ABOVE 7500 FEET FOR
COZ003.
UT...NONE.
&&
$$
UPDATE...JAD
SHORT TERM...JOE
LONG TERM...JAM
AVIATION...JAD
AREA FORECAST DISCUSSION
NWS BOISE ID
846 PM MST WED FEB 5 2014
.DISCUSSION...LIGHT SNOW AND LOW CLOUDS EXTENDED ACROSS CENTRAL
OREGON THROUGH FAR SOUTH IDAHO AS OF 8 PM. CLOUD TOPS WERE
COOLING OFFSHORE IN ADVANCE OF THE NEXT SYSTEM POISED TO CROSS SE
OREGON EARLY THURSDAY AND SW IDAHO LATE THURSDAY THROUGH EARLY
FRIDAY. LIGHT TO MODERATE SNOW IS EXPECTED AS THE OFFSHORE SYSTEM
CROSSES THE AREA...AND THE LOWER CLOUD DECK ACROSS THE SRN
VALLEYS. HRRR MODELS AGREE WITH TIMING OF THE ONSET OF LIGHT SNOW
TO BURNS BEFORE SUNRISE. A WINTER WEATHER ADVISORY IS ALREADY OUT
FOR THIS NEXT SYSTEM AS WELL AS A FEW IMPULSES AFTER IT...AND THAT
LOOKS RIGHT ON ESPECIALLY FOR PLANNING PURPOSES THROUGH THE
WEEKEND. SEVERAL PERIODS OF PRECIPITATION WILL CROSS THE AREA WITH
SNOW THROUGH SATURDAY. A MILDER BUT STILL MOIST SYSTEM WILL CROSS
THE AREA LATE IN THE WEEKEND...BUT THE EXACT TIMING OF HEAVIER
PRECIPITATION RATES ARE STILL VARYING. NO CHANGES TO THE FORECAST
THIS SHIFT.
&&
.AVIATION...FOR TONIGHT AREAS OF MVFR IN LIGHT SNOW ACROSS SE OREGON
AND SW IDAHO SOUTH OF A LINE FROM KBNO-KONO-KSNT WILL OBSCURE MTNS.
WILL SEE AREAS OF IFR DEVELOP THURSDAY AS SNOW BECOMES WIDESPREAD
ACROSS SE OREGON AND SW IDAHO...AND EXTENDS NORTH TO KBKE AND KMYL.
FOR PLANNING PURPOSES EXPECT PERIODS OF IFR IN SNOW TO CONTINUE
THROUGH SATURDAY NIGHT FOR ALL OF SE OREGON AND SW IDAHO. EASTERLY
SURFACE WINDS DEVELOP TONIGHT WITH SPEEDS UP TO 20 KTS ON THURSDAY.
WEST WINDS ALOFT 20 KTS TONIGHT INCREASING TO 40 KTS LATE
THURSDAY.
&&
.PREV DISCUSSION...
SHORT TERM...TONIGHT THROUGH SATURDAY...COMPLEX AND CONTINUALLY
EVOLVING SYSTEM COMING IN OVER THE NEXT SEVERAL DAYS. WINTER
WEATHER ADVISORIES HAVE BEEN EXPANDED TO INCLUDE EACH ZONE IN THE
FORECAST AREA FOR AT LEAST 18 HOURS...AND THE LONGEST-RUNNING
ADVISORIES NOW REACH INTO SATURDAY AFTERNOON. SIMPLY PUT...WE
WILL SEE A WARM FRONT MOVING THROUGH THE AREA THURSDAY FOLLOWED BY
A COLD FRONT FRIDAY...AND THEN ANOTHER WARM FRONT SATURDAY. THE
AIR THAT MOVES IN AFTER THE INITIAL WARM FRONT WILL STILL BE COLD
ENOUGH TO ALLOW SNOW ALL THE WAY TO THE LOWEST ELEVATIONS.
THEREFORE WE WILL SEE A PROLONGED PERIOD OF INTERMITTENT SNOWFALL
LASTING THU THROUGH SAT...AND EVEN BEYOND THAT IN THE WEST CENTRAL
AND BOISE MOUNTAINS. SNOWFALL TOTAL ARE DETAILED IN THE TEXT OF
THE ADVISORY. BECAUSE THIS SYSTEM STILL HAS SO MUCH ENERGY OFF THE
COAST...AND BECAUSE OF THE HIGH-AMPLITUDE FLOW PATTERN JUST TO OUR
WEST...THE DETAILS OF THE PRECIPITATION REMAIN IN FLUX FROM MODEL
RUN TO MODEL RUN...AND SIGNIFICANT DIFFERENCES STILL EXIST BETWEEN
THE MODELS. AT THIS POINT IT IS CLEAR THAT WE ARE IN FOR A
SIGNIFICANT SNOWFALL. THEREFORE THE ADVISORIES ARE OUT THERE.
HOWEVER...THERE IS STILL NOTABLE UNCERTAINTY IN THE DETAILS OF
EXACTLY WHEN AND WHERE THE HEAVIEST SNOW WILL FALL. SO WE DO
EXPECT SOME CHANGES TO THE ADVISORIES AS WE GO THROUGH THE NEXT
COUPLE DAYS. TEMPS WILL BE DIFFICULT BECAUSE WHERE AND WHEN THE
SNOW FALLS...THE DAYTIME HIGHS WILL BE INHIBITED SIGNIFICANTLY.
DECIDED TO GO WITH GUIDANCE THAT LEANED ON THE COLDER SIDE DURING
THE DAY AND MILDER SIDE AT NIGHT OWING TO CLOUD COVER AND THE
MODERATING INFLUENCE OF PRECIPITATION. NEEDLESS TO SAY...DIURNAL
RANGES WILL BE SMALL...EXCEPT ON SATURDAY FOR LOCATIONS THAT
BREAK OUT AFTER THE FINAL WARM FRONT PASSES BY. THIS IS MOST
LIKELY IN SOUTHERN HARNEY AND MALHEUR COUNTIES...AND PERHAPS THE
SOUTHWEST HIGHLANDS. WINDS WILL NOT BE MUCH OF A FACTOR FOR MOST
AREAS...BUT WE WILL GET GUSTS ABOVE 20 MPH IN THE HIGHER TERRAIN
OF SRN MALHEUR...SRN HARNEY...AND OWYHEE COUNTIES FRIDAY INTO
SATURDAY.
LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY...MODELS AGREE ON
AN UNSETTLED PATTERN FOR OUR AREA WITH ZONAL FLOW THROUGH A LOW
AMPLITUDE LONGWAVE RIDGE CENTERED OVER THE INTERMOUNTAIN REGION.
TEMPERATURES WILL AVERAGE NEAR NORMAL THROUGH THE PERIOD...WITH
CLOUD COVER LIMITING DIURNAL RANGE. THERE WILL BE A CHANCE OF
PRECIPITATION EACH DAY...WITH THE MAIN EPISODE SCHEDULED FOR
SATURDAY NIGHT THROUGH SUNDAY NIGHT. MAINLY RAIN WILL FALL IN THE
LOWER VALLEYS...BUT UP TO A FOOT OF SNOW POSSIBLE OVER THE HIGHER
MOUNTAINS OF CENTRAL IDAHO. THERE WILL BE A BRIEF BREAK MONDAY
AND TUESDAY WITH PRECIPITATION CONFINED MAINLY TO THE MOUNTAINS
NORTH OF THE SNAKE RIVER VALLEY. TUESDAY NIGHT AND WEDNESDAY
PRECIPITATION CHANCES ARE EXPECTED TO AGAIN INCREASE ACROSS THE
AREA.
&&
.BOI WATCHES/WARNINGS/ADVISORIES...
ID...WINTER WEATHER ADVISORY FROM 5 PM THURSDAY TO 5 PM MST SATURDAY
IDZ012-014-016.
WINTER WEATHER ADVISORY FROM 5 AM THURSDAY TO 5 PM MST SATURDAY
IDZ015-029-030.
WINTER WEATHER ADVISORY FROM 5 PM THURSDAY TO 5 PM MST FRIDAY
IDZ011-013-028-033.
OR...WINTER WEATHER ADVISORY FROM 5 PM THURSDAY TO 5 PM MST SATURDAY
ORZ064.
WINTER WEATHER ADVISORY FROM 5 AM MST /4 AM PST/ THURSDAY TO 5
PM MST /4 PM PST/ SATURDAY ORZ061-063.
WINTER WEATHER ADVISORY FROM 10 AM THURSDAY TO 4 AM PST FRIDAY
ORZ062.
&&
$$
WEATHER.GOV/BOISE
DISCUSSION...VM
AVIATION.....DG
PREV SHORT TERM...SP
PREV LONG TERM....JT/DD
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1144 PM CST WED FEB 5 2014
.UPDATE...
ISSUED AT 938 PM CST WED FEB 5 2014
IT APPEARS THAT MOST AREAS ACROSS THE FA HAVE AT LEAST SOME
CLEARING...ALTHOUGH MID-HIGH CLOUDS REMAIN SCT-BKN AT TIMES. THE
LOW CLOUDS UPSTREAM IN MANITOBA BREAK APART AS THEY APPROACH THE
REGION...WHICH THE RAP INDICATES. WILL CONTINUE WITH THE TREND OF
LOWERING SKY THROUGH THE NIGHT (ALTHOUGH WITH LOWER THAN NORMAL
CONFIDENCE). MODELS INDICATE 10-15 KNOT WINDS WEST OF THE
VALLEY...WITH MUCH LIGHTER WINDS EAST OF THE VALLEY. THUS...MIN
TEMPS WILL BE WARMER WEST OF THE VALLEY...WHICH THE CURRENT
FORECAST INDICATES. WIND CHILL ADVISORY IN GOOD SHAPE.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 255 PM CST WED FEB 5 2014
THE CHALLENGE FOR THE FORECAST IS TEMPS AND WIND CHILLS AS CLOUD
TRENDS CONTINUE TO BE DIFFICULT TO FORECAST.
SHORT WAVE EMBEDDED IN 500MB TROUGH CENTERED OVER THE FA IS
CONTINUING TO BRING CLOUDS TO THE CWFA. ENERGY WILL SLOWLY
PINWHEEL EAST SOUTHEAST AND WEAKEN TONIGHT. HOW MUCH CLEARING WILL
OCCUR AS THE SYSTEM EXISTS IS UNCERTAIN AS UPSTREAM STRATUS DECK
IN SASKATCHEWAN MAY LIMIT TEMPERATURE FROM FALLING TO DRAMATICALLY
OVERNIGHT. CLOUD DECK DECREASING IN COVERAGE DEPICTED IN MODEL
SOLUTIONS OVERNIGHT BUT UNCERTAINTY REMAINS. NONETHELESS TEMPS
AND WIND TO COMBINE ONCE AGAIN FOR APPARENT TEMPS TO RANGE FROM 25
TO 40 BELOW. AS A RESULT THE ALMOST DAILY WIND CHILL ADVISORY HAS
BEEN ISSUED FOR THIS EVENING THRU 18Z THURSDAY.
SLIGHTLY HIGHER MAX TEMPS EXPECTED TOMORROW WITH 925MB TEMPS A
BIT WARMER AND WARMING WESTERLY SFC WINDS DEVELOP AS PRESSURE
GRADIENT TIGHTENS ACROSS THE REGION BETWEEN THE SFC HIGH OVER THE
WESTERN DAKOTAS AND THE HUDSON BAY STACKED LOW PRESSURE SYSTEM.
WESTERLY WINDS CONTINUE THURSDAY NIGHT WITH SOME CLOUD COVER
KEEPING TEMPS IN THE 5 TO 10 BELOW RANGE.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 255 PM CST WED FEB 5 2014
FRIDAY AND SATURDAY MORE OF THE SAME WITH 500MB NW FLOW ALOFT AND
THE NEXT RE-ENFORCING SHOT OF COLD AIR EXPECTED SATURDAY MORNING.
TEMPS CONTINUE TO BE BELOW NORMAL WITH HIGHS IN THE SINGLE DIGITS
AND LOW 5 TO 15 BELOW.
MODELS REMAIN IN GOOD AGREEMENT IN SHOWING HIGH PRESSURE SETTLING
OVER THE AREA WITH LIGHT WINDS SUNDAY INTO MONDAY. TEMPS WILL
REMAIN WELL BELOW NORMAL. 500 MB PATTERN FLATTENS A BIT BY NEXT
WED WITH A PACIFIC LOW MOVING EAST NEAR THE INTL BORDER AND SHOULD
SPREAD A CHANCE FOR SOME LIGHT SNOWS TUES NIGHT-WED BUT MOST OF
THE ACTION LOOKS NORTH OF THE LOW IN CANADA. 12Z ECMWF IS A BIT
WARMER SOUTH OF THE LOW THAN GFS...BUT OVERALL AN UPWARD TREND IN
TEMPS SEEN BY WED WITH TEENS FOR HIGHS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1144 PM CST WED FEB 5 2014
CIGS HAVE BEEN GRADUALLY CLEARING OR RISING AS EXPECTED. THERE IS
AN AREA OF MVFR CIGS THAT CONTINUES TO APPROACH THE REGION.
HOWEVER...THESE CIGS ARE DISSIPATING AS THEY ENTER...AND THE RAP
GUIDANCE INDICATES THIS TREND WILL CONTINUE. THERE MAY BE BRIEF
MOMENTS OF MVFR CIGS THIS MORNING...BUT NOTHING LONG TERM IS
EXPECTED.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WIND CHILL ADVISORY UNTIL NOON CST THURSDAY FOR NDZ006>008-
014>016-024-026>030-038-039-049-052>054.
MN...WIND CHILL ADVISORY UNTIL NOON CST THURSDAY FOR MNZ001>009-
013>017-022>024-027>032-040.
&&
$$
UPDATE...TG
SHORT TERM...JK
LONG TERM...JK/RIDDLE
AVIATION...TG
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
937 PM CST WED FEB 5 2014
.UPDATE...
ISSUED AT 938 PM CST WED FEB 5 2014
IT APPEARS THAT MOST AREAS ACROSS THE FA HAVE AT LEAST SOME
CLEARING...ALTHOUGH MID-HIGH CLOUDS REMAIN SCT-BKN AT TIMES. THE
LOW CLOUDS UPSTREAM IN MANITOBA BREAK APART AS THEY APPROACH THE
REGION...WHICH THE RAP INDICATES. WILL CONTINUE WITH THE TREND OF
LOWERING SKY THROUGH THE NIGHT (ALTHOUGH WITH LOWER THAN NORMAL
CONFIDENCE). MODELS INDICATE 10-15 KNOT WINDS WEST OF THE
VALLEY...WITH MUCH LIGHTER WINDS EAST OF THE VALLEY. THUS...MIN
TEMPS WILL BE WARMER WEST OF THE VALLEY...WHICH THE CURRENT
FORECAST INDICATES. WIND CHILL ADVISORY IN GOOD SHAPE.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 255 PM CST WED FEB 5 2014
THE CHALLENGE FOR THE FORECAST IS TEMPS AND WIND CHILLS AS CLOUD
TRENDS CONTINUE TO BE DIFFICULT TO FORECAST.
SHORT WAVE EMBEDDED IN 500MB TROUGH CENTERED OVER THE FA IS
CONTINUING TO BRING CLOUDS TO THE CWFA. ENERGY WILL SLOWLY
PINWHEEL EAST SOUTHEAST AND WEAKEN TONIGHT. HOW MUCH CLEARING WILL
OCCUR AS THE SYSTEM EXISTS IS UNCERTAIN AS UPSTREAM STRATUS DECK
IN SASKATCHEWAN MAY LIMIT TEMPERATURE FROM FALLING TO DRAMATICALLY
OVERNIGHT. CLOUD DECK DECREASING IN COVERAGE DEPICTED IN MODEL
SOLUTIONS OVERNIGHT BUT UNCERTAINTY REMAINS. NONETHELESS TEMPS
AND WIND TO COMBINE ONCE AGAIN FOR APPARENT TEMPS TO RANGE FROM 25
TO 40 BELOW. AS A RESULT THE ALMOST DAILY WIND CHILL ADVISORY HAS
BEEN ISSUED FOR THIS EVENING THRU 18Z THURSDAY.
SLIGHTLY HIGHER MAX TEMPS EXPECTED TOMORROW WITH 925MB TEMPS A
BIT WARMER AND WARMING WESTERLY SFC WINDS DEVELOP AS PRESSURE
GRADIENT TIGHTENS ACROSS THE REGION BETWEEN THE SFC HIGH OVER THE
WESTERN DAKOTAS AND THE HUDSON BAY STACKED LOW PRESSURE SYSTEM.
WESTERLY WINDS CONTINUE THURSDAY NIGHT WITH SOME CLOUD COVER
KEEPING TEMPS IN THE 5 TO 10 BELOW RANGE.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 255 PM CST WED FEB 5 2014
FRIDAY AND SATURDAY MORE OF THE SAME WITH 500MB NW FLOW ALOFT AND
THE NEXT RE-ENFORCING SHOT OF COLD AIR EXPECTED SATURDAY MORNING.
TEMPS CONTINUE TO BE BELOW NORMAL WITH HIGHS IN THE SINGLE DIGITS
AND LOW 5 TO 15 BELOW.
MODELS REMAIN IN GOOD AGREEMENT IN SHOWING HIGH PRESSURE SETTLING
OVER THE AREA WITH LIGHT WINDS SUNDAY INTO MONDAY. TEMPS WILL
REMAIN WELL BELOW NORMAL. 500 MB PATTERN FLATTENS A BIT BY NEXT
WED WITH A PACIFIC LOW MOVING EAST NEAR THE INTL BORDER AND SHOULD
SPREAD A CHANCE FOR SOME LIGHT SNOWS TUES NIGHT-WED BUT MOST OF
THE ACTION LOOKS NORTH OF THE LOW IN CANADA. 12Z ECMWF IS A BIT
WARMER SOUTH OF THE LOW THAN GFS...BUT OVERALL AN UPWARD TREND IN
TEMPS SEEN BY WED WITH TEENS FOR HIGHS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 605 PM CST WED FEB 5 2014
SIMILAR IDEA TO PREVIOUS TAF ISSUANCE...BUT KEPT THE MVFR CIGS IN
A BIT LONGER FOR KBJI-KTVF-KGFK-KDVL. WILL MONITOR AND IF THESE
LOWER CIGS CLEAR QUICKER WILL AMEND ACCORDINGLY.
STRATOCU UPSTREAM IN MANITOBA APPEARS TO BE BREAKING AS IT
APPROACHES THE REGION...BUT CONFIDENCE WITH HOW THESE CLOUDS
EVOLVE TONIGHT REMAINS LOWER THAN AVERAGE.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WIND CHILL ADVISORY UNTIL NOON CST THURSDAY FOR NDZ006>008-
014>016-024-026>030-038-039-049-052>054.
MN...WIND CHILL ADVISORY UNTIL NOON CST THURSDAY FOR MNZ001>009-
013>017-022>024-027>032-040.
&&
$$
UPDATE...TG
SHORT TERM...JK
LONG TERM...JK/RIDDLE
AVIATION...TG
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1259 AM EST THU FEB 6 2014
.SYNOPSIS...
COLDER WITH LIGHT UPSLOPE SNOW SHOWERS TONIGHT IN THE WAKE OF LOW
PRESSURE. HIGH PRESSURE FOR THE END OF THE WEEK. WEAK MID/UPPER
LEVEL DISTURBANCES OVER THE WEEKEND IN BOARD TROF.
&&
.NEAR TERM /THROUGH TODAY/...
UPDATED POPS BLENDING IN THE HIGH RESOLUTION MODEL HRRR QPF AS IT
LOOKS WELL INITIALIZED BY RADAR. FINE LINES OF SNOW SHOWERS ARE
EVIDENT ON RADAR IMAGES PERPENDICULAR TO THE EASTERN MOUNTAINS.
EXPECT AT LEAST ONE INCH OR TWO OVER THE HIGHER TERRAIN...AND JUST
A COATING OF SNOW ACROSS CENTRAL LOWER ELEVATIONS. PCPN SHOULD
DIMINISH IN COVERAGE BY MIDNIGHT.
STILL WATER LEVELS FROM LITTLE SANDY RIVER AT GRAYSON CONTINUES
ABOVE FLOOD STATE BUT HYDROGRAPH SHOWS IT HAS CRESTED. WITH THE
BULK OF PCPN ENDED...AND NOT SIGNIFICANT PCPN EXPECTED...BELIEVE
WATER LEVELS OR MOST RIVER SHOULD BE RUNNING HIGH...CRESTING OR
LOWERING. EXCEPTIONS WILL BE SMALL STREAMS WITH DEBRIS AND/OR ICE
JAMS THAT COULD PRODUCE MINOR FLOODING PROBLEMS.
ANY LINGERING LIGHT SNOW SHOWERS WILL TAPER OFF ACROSS THE
MOUNTAINS BY LATE THURSDAY MORNING. WILL STILL BE PLENTY OF LOW
CLOUD COVER LINGERING THROUGH THURSDAY...AS MOISTURE REMAINS
TRAPPED BENEATH LOW LEVEL INVERSION...BUT WILL START TO SEE SOME
LIFTING/PARTIAL CLEARING BY THURSDAY AFTERNOON. HOWEVER...WITH
THAT SAID...WILL ALSO SEE AN INCREASE IN MID AND HIGH CLOUDS FROM
SYSTEM TO THE SOUTH...SO OVERALL...RELATIVELY CLOUDY CONDITIONS
WILL PERSIST.
MUCH COLDER AIR WILL MOVE INTO THE REGION TONIGHT...WITH 850MB
TEMPS FALLING TO AROUND -14C. DID LOWER OVERNIGHT LOW TEMPS
SLIGHTLY FROM PREVIOUS FORECAST...BUT DIDNT WANT TO GO TOO COLD
WITH PERSISTENT CLOUD COVER.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY/...
SHORT TERM PERIOD BEGINS QUIETLY WITH WEAKLY-AMPLIFIED SW FLOW
ALOFT. AT THE SURFACE...WEAK WESTERLY FLOW WILL CONTINUE OVERNIGHT
THU NIGHT WITH HIGH PRESSURE PUSHING INTO THE AREA FROM THE
WEST...PROGGED TO BE CENTERED OVER THE MID-MISS VALLEY BY 12Z FRI. A
BIT OF A TOUGH CALL ON OVERNIGHT MINS BUT A WEAK RIPPLE IN THE FLOW
PUSHING ACROSS OVERNIGHT WILL KEEP LOW CLOUDS IN PLACE FOR MUCH OF
THE AREA...AND AS SUCH WILL SIDE ON THE WARMER SIDE OF GUIDANCE.
WILL SEE MINS GENERALLY MID/UPPER TEENS TO LOW 20S WEST VIRGINIA
LOWLANDS...WHILE SE OHIO DROPS INTO THE UPPER SINGLE DIGITS TO LOW
TEENS GENERALLY. SOME QUESTIONS WITH REGARD TO FRIDAY SKY COVER WITH
A DECENT AMOUNT OF LOW LEVEL MOISTURE TRAPPED...ESPECIALLY EAST OF
THE OHIO AS USUAL. COLD ADVECTION CEASES DURING THE AFTERNOON
HOWEVER AND WITH THAT...WILL KEEP A MOSTLY CLOUDY SKY FOR MOST THEN
ALLOW FOR SOME PARTLY CLOUDY SKIES LATER IN THE AFTERNOON.
UNFORTUNATELY...HAD TO LOWER MAX TEMPS FRIDAY BY A GOOD 3F-5F FOR
MOST LOCATIONS PER LATEST NWP OUTPUT AND MOS GUIDE. PROGGED 925MB
TEMPS OF -7C TO -8C ALONG THE I-64 CORRIDOR WOULD ONLY SUPPORT SFC
TEMPS STRUGGLING TO BREAK THE FREEZING MARK WITH FULL SUN AND
MIXING. TEMPS ACROSS SE OHIO MEANWHILE WILL ONLY REACH THE LOW/MID
20S WITH 925MB TEMPS BTWN -11C AND -13C AND A RESIDUAL SNOW
COVER.
BY FRIDAY NIGHT THROUGH SATURDAY DIFFS IN VARIOUS NWP OUTPUT
CONTINUE WITH THE SYSTEM PROGGED FOR THE WEEKEND. OPERATIONAL MODELS
ARE COMING INTO BETTER AGREEMENT WITH REGARD TO THE SYNOPTIC SCALE
FEATURES...WITH OUR FORECAST AREA GENERALLY BEING SANDWICHED BTWN
THE SFC LOW WELL TO OUR SOUTHEAST...AND THE NEXT UPPER TROUGH AND
ASSOC SFC LOW PROGRESSING EASTWARD OVER THE CENTRAL AND UPPER
MIDWEST. ANOTHER QUICK-MOVING S/W TROUGH IN THE FLOW ALOFT AND ITS
MOISTURE FIELD PROVIDES THE MAIN DIFFS WITH POTENTIAL PRECIP FOR
SAT...WITH THE LATEST NAM12 SHOWING FAIRLY MEAGER LLVL MOISTURE AND
LATEST OP GFS MORE BULLISH WITH ITS HANDLING OF THE MOISTURE. IN
ESSENCE...WILL BRING AN AREA OF SOMEWHAT HIGHER POPS ACROSS THE
SOUTHERN/MOUNTAINS ZONES BTWN 12Z-18Z SAT...THEN WILL TRANSITION THE
HIGHER POPS TOWARDS THE NORTH AND NORTHWEST DURING THE AFTERNOON AS
THE MORNING SYSTEM PULLS AWAY WITH THE SYSTEM TO THE WEST GETTING A
LITTLE CLOSER. LOWERED MAX TEMPS JUST A BIT BUT STILL EXPECT THE
UPPER 30S TO NEAR 40 POSSIBLE FROM THE I-64 CORRIDOR AND LOWER 40S
FOR THE SOUTHERN COALFIELDS. WITH FAIRLY DRY AIR AT THE SFC WITH
DECENT DEWPOINT DEPRESSIONS EVEN SAT AFTERNOON...MAINTAINED MOSTLY
SNOW OR AT LEAST A RAIN/SNOW MIX FOR MOST LOCATIONS EXCEPT THE
COALFIELDS AS ANY PRECIP WHICH COULD BRIEFLY BEGIN AS RAIN FURTHER
NORTH WOULD QUICKLY TRANSITION TO SNOW. NOT EXPECTING MUCH IN THE
WAY OF ACCUMULATION HOWEVER BUT DID INSERT UP TO A HALF-INCH ACROSS
THE FAR NORTHWEST ZONES OF SE OHIO AND THE EAST MOUNTAINS BY END OF
THE PERIOD.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
CONSIDERING THE WET GROUND AND SWOLLEN WATERWAYS...THANKFULLY...WE
CONTINUED TO FORECAST NO MAJOR STORM FOR THIS WEEKEND.
ALSO...NO COLD WAVES...BUT BELOW NORMAL TEMPERATURES TRYING TO
MODERATE TOWARD SEASONABLE.
TRIED TO HOLD ONTO POPS A BIT HIGHER THAN GUIDANCE FOR THE
POSSIBILITY OF SOME LIGHT SNOW IN THE BOARD 500 MB TROF SATURDAY
NIGHT INTO SUNDAY. WE CONTINUE TO FORECAST NO MAJOR STORM THIS
WEEKEND.
COLDER AIR STILL FORECAST TO ADVECT IN SUNDAY NIGHT INTO MONDAY.
AGAIN HELD ONTO HIGHER POPS FOR LINGERING SNOW SHOWERS ESPECIALLY IN
WEST VIRGINIA SUNDAY NIGHT. THERE MAY EVEN BE SOME MID LEVEL
DISTURBANCES STILL CROSSING SUNDAY NIGHT IN THAT BROAD 500 MB TROF.
MAINLY DRY MONDAY. TRIED TO STREAK EAST...SOME CHANCE POPS MONDAY
NIGHT IN THE FAST ZONAL FLOW.
WENT HIGHER POPS THAN WPC GUIDANCE...FOR TUESDAY INTO
WEDNESDAY...WITH LIKELY POPS FIRST INTRODUCED ACROSS SOUTHERN
COUNTIES. 12Z GFS FURTHER SOUTH COMPARED TO ECMWF. NORTHERN
SOLUTION COULD BE SOME SNOW TO RAIN.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
EXPECT A SLOW IMPROVEMENT TO THE AVIATION CONDITIONS TONIGHT WITH
THE LIGHT SNOW ENDING. MVFR CEILINGS BECOME VFR GENERALLY AFTER
18Z THURSDAY...GIVE OR TAKE A COUPLE OF HOURS DEPENDING ON THE
TERMINAL. VFR EXPECTED INTO THURSDAY NIGHT WITH A DRY FORECAST IN
PLACE.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z FRIDAY...
FORECAST CONFIDENCE: MEDIUM TO HIGH.
ALTERNATE SCENARIOS: CEILINGS MAY LIFT TO VFR SOONER THAN FORECAST.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE THU 02/06/14
UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
EST 1HRLY 01 02 03 04 05 06 07 08 09 10 11 12
CRW CONSISTENCY M M M M L L L M H H H H
HTS CONSISTENCY H H H M M H H H H H H H
BKW CONSISTENCY M M M M M L L L H H H H
EKN CONSISTENCY M M M M M M M L L L L H
PKB CONSISTENCY H L H H H H H H H M H H
CKB CONSISTENCY M M M M M M M L L L M H
AFTER 06Z FRIDAY...
IFR POSSIBLE SATURDAY AND SUNDAY IN RAIN AND SNOW SHOWERS.
&&
.EQUIPMENT...
PKB ASOS HAS BEEN EXPERIENCING MALFUNCTIONS...RESULTING IN SOME
MISSING OR INCOMPLETE OBSERVATIONS. TECHNICIANS ARE AWARE OF THE
PROBLEM AND PARTS ARE BEING ACQUIRED.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/50/SL
NEAR TERM...ARJ/SL
SHORT TERM...50
LONG TERM...KTB
AVIATION...26
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
703 PM EST WED FEB 5 2014
.SYNOPSIS...
COLDER WITH LIGHT UPSLOPE SNOW SHOWERS TONIGHT IN THE WAKE OF LOW
PRESSURE. HIGH PRESSURE FOR THE END OF THE WEEK. WEAK MID/UPPER
LEVEL DISTURBANCES OVER THE WEEKEND IN BOARD TROF.
&&
.NEAR TERM /THROUGH THURSDAY/...
UPDATED POPS BLENDING IN THE HIGH RESOLUTION MODEL HRRR QPF AS IT
LOOKS WELL INITIALIZED BY RADAR. FINE LINES OF SNOW SHOWERS ARE
EVIDENT ON RADAR IMAGES PERPENDICULAR TO THE EASTERN MOUNTAINS.
EXPECT AT LEAST ONE INCH OR TWO OVER THE HIGHER TERRAIN...AND JUST
A COATING OF SNOW ACROSS CENTRAL LOWER ELEVATIONS. PCPN SHOULD
DIMINISH IN COVERAGE BY MIDNIGHT.
STILL WATER LEVELS FROM LITTLE SANDY RIVER AT GRAYSON CONTINUES
ABOVE FLOOD STATE BUT HYDROGRAPH SHOWS IT HAS CRESTED. WITH THE
BULK OF PCPN ENDED...AND NOT SIGNIFICANT PCPN EXPECTED...BELIEVE
WATER LEVELS OR MOST RIVER SHOULD BE RUNNING HIGH...CRESTING OR
LOWERING. EXCEPTIONS WILL BE SMALL STREAMS WITH DEBRIS AND/OR ICE
JAMS THAT COULD PRODUCE MINOR FLOODING PROBLEMS.
ANY LINGERING LIGHT SNOW SHOWERS WILL TAPER OFF ACROSS THE
MOUNTAINS BY LATE THURSDAY MORNING. WILL STILL BE PLENTY OF LOW
CLOUD COVER LINGERING THROUGH THURSDAY...AS MOISTURE REMAINS
TRAPPED BENEATH LOW LEVEL INVERSION...BUT WILL START TO SEE SOME
LIFTING/PARTIAL CLEARING BY THURSDAY AFTERNOON. HOWEVER...WITH
THAT SAID...WILL ALSO SEE AN INCREASE IN MID AND HIGH CLOUDS FROM
SYSTEM TO THE SOUTH...SO OVERALL...RELATIVELY CLOUDY CONDITIONS
WILL PERSIST.
MUCH COLDER AIR WILL MOVE INTO THE REGION TONIGHT...WITH 850MB
TEMPS FALLING TO AROUND -14C. DID LOWER OVERNIGHT LOW TEMPS
SLIGHTLY FROM PREVIOUS FORECAST...BUT DIDNT WANT TO GO TOO COLD
WITH PERSISTENT CLOUD COVER.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
SHORT TERM PERIOD BEGINS QUIETLY WITH WEAKLY-AMPLIFIED SW FLOW
ALOFT. AT THE SURFACE...WEAK WESTERLY FLOW WILL CONTINUE OVERNIGHT
THU NIGHT WITH HIGH PRESSURE PUSHING INTO THE AREA FROM THE
WEST...PROGGED TO BE CENTERED OVER THE MID-MISS VALLEY BY 12Z FRI. A
BIT OF A TOUGH CALL ON OVERNIGHT MINS BUT A WEAK RIPPLE IN THE FLOW
PUSHING ACROSS OVERNIGHT WILL KEEP LOW CLOUDS IN PLACE FOR MUCH OF
THE AREA...AND AS SUCH WILL SIDE ON THE WARMER SIDE OF GUIDANCE.
WILL SEE MINS GENERALLY MID/UPPER TEENS TO LOW 20S WEST VIRGINIA
LOWLANDS...WHILE SE OHIO DROPS INTO THE UPPER SINGLE DIGITS TO LOW
TEENS GENERALLY. SOME QUESTIONS WITH REGARD TO FRIDAY SKY COVER WITH
A DECENT AMOUNT OF LOW LEVEL MOISTURE TRAPPED...ESPECIALLY EAST OF
THE OHIO AS USUAL. COLD ADVECTION CEASES DURING THE AFTERNOON
HOWEVER AND WITH THAT...WILL KEEP A MOSTLY CLOUDY SKY FOR MOST THEN
ALLOW FOR SOME PARTLY CLOUDY SKIES LATER IN THE AFTERNOON.
UNFORTUNATELY...HAD TO LOWER MAX TEMPS FRIDAY BY A GOOD 3F-5F FOR
MOST LOCATIONS PER LATEST NWP OUTPUT AND MOS GUIDE. PROGGED 925MB
TEMPS OF -7C TO -8C ALONG THE I-64 CORRIDOR WOULD ONLY SUPPORT SFC
TEMPS STRUGGLING TO BREAK THE FREEZING MARK WITH FULL SUN AND
MIXING. TEMPS ACROSS SE OHIO MEANWHILE WILL ONLY REACH THE LOW/MID
20S WITH 925MB TEMPS BTWN -11C AND -13C AND A RESIDUAL SNOW
COVER.
BY FRIDAY NIGHT THROUGH SATURDAY DIFFS IN VARIOUS NWP OUTPUT
CONTINUE WITH THE SYSTEM PROGGED FOR THE WEEKEND. OPERATIONAL MODELS
ARE COMING INTO BETTER AGREEMENT WITH REGARD TO THE SYNOPTIC SCALE
FEATURES...WITH OUR FORECAST AREA GENERALLY BEING SANDWICHED BTWN
THE SFC LOW WELL TO OUR SOUTHEAST...AND THE NEXT UPPER TROUGH AND
ASSOC SFC LOW PROGRESSING EASTWARD OVER THE CENTRAL AND UPPER
MIDWEST. ANOTHER QUICK-MOVING S/W TROUGH IN THE FLOW ALOFT AND ITS
MOISTURE FIELD PROVIDES THE MAIN DIFFS WITH POTENTIAL PRECIP FOR
SAT...WITH THE LATEST NAM12 SHOWING FAIRLY MEAGER LLVL MOISTURE AND
LATEST OP GFS MORE BULLISH WITH ITS HANDLING OF THE MOISTURE. IN
ESSENCE...WILL BRING AN AREA OF SOMEWHAT HIGHER POPS ACROSS THE
SOUTHERN/MOUNTAINS ZONES BTWN 12Z-18Z SAT...THEN WILL TRANSITION THE
HIGHER POPS TOWARDS THE NORTH AND NORTHWEST DURING THE AFTERNOON AS
THE MORNING SYSTEM PULLS AWAY WITH THE SYSTEM TO THE WEST GETTING A
LITTLE CLOSER. LOWERED MAX TEMPS JUST A BIT BUT STILL EXPECT THE
UPPER 30S TO NEAR 40 POSSIBLE FROM THE I-64 CORRIDOR AND LOWER 40S
FOR THE SOUTHERN COALFIELDS. WITH FAIRLY DRY AIR AT THE SFC WITH
DECENT DEWPOINT DEPRESSIONS EVEN SAT AFTERNOON...MAINTAINED MOSTLY
SNOW OR AT LEAST A RAIN/SNOW MIX FOR MOST LOCATIONS EXCEPT THE
COALFIELDS AS ANY PRECIP WHICH COULD BRIEFLY BEGIN AS RAIN FURTHER
NORTH WOULD QUICKLY TRANSITION TO SNOW. NOT EXPECTING MUCH IN THE
WAY OF ACCUMULATION HOWEVER BUT DID INSERT UP TO A HALF-INCH ACROSS
THE FAR NORTHWEST ZONES OF SE OHIO AND THE EAST MOUNTAINS BY END OF
THE PERIOD.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
CONSIDERING THE WET GROUND AND SWOLLEN WATERWAYS...THANKFULLY...WE
CONTINUED TO FORECAST NO MAJOR STORM FOR THIS WEEKEND.
ALSO...NO COLD WAVES...BUT BELOW NORMAL TEMPERATURES TRYING TO
MODERATE TOWARD SEASONABLE.
TRIED TO HOLD ONTO POPS A BIT HIGHER THAN GUIDANCE FOR THE
POSSIBILITY OF SOME LIGHT SNOW IN THE BOARD 500 MB TROF SATURDAY
NIGHT INTO SUNDAY. WE CONTINUE TO FORECAST NO MAJOR STORM THIS
WEEKEND.
COLDER AIR STILL FORECAST TO ADVECT IN SUNDAY NIGHT INTO MONDAY.
AGAIN HELD ONTO HIGHER POPS FOR LINGERING SNOW SHOWERS ESPECIALLY IN
WEST VIRGINIA SUNDAY NIGHT. THERE MAY EVEN BE SOME MID LEVEL
DISTURBANCES STILL CROSSING SUNDAY NIGHT IN THAT BROAD 500 MB TROF.
MAINLY DRY MONDAY. TRIED TO STREAK EAST...SOME CHANCE POPS MONDAY
NIGHT IN THE FAST ZONAL FLOW.
WENT HIGHER POPS THAN WPC GUIDANCE...FOR TUESDAY INTO
WEDNESDAY...WITH LIKELY POPS FIRST INTRODUCED ACROSS SOUTHERN
COUNTIES. 12Z GFS FURTHER SOUTH COMPARED TO ECMWF. NORTHERN
SOLUTION COULD BE SOME SNOW TO RAIN.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
MVFR CONDITIONS WILL CONTINUE OR DETERIORATE INTO IFR UNDER LOW
CEILINGS OR SNOW SHOWERS. PCPN WILL BE LIGHT BUT CONCENTRATED IN
FINE LINES OF SNOWFALL. GUSTY WESTERLY/NORTHWESTERLY WINDS WILL
DIMINISH BY 09Z...AS THE ATMOSPHERE TRIES TO DECOUPLE.
CEILINGS COULD DETERIORATE TO IFR/LIFR OVER BKW...AND EKN WHERE
MOISTURE CAN BE TRAPPED AND CONDENSATE AT LOWER LEVELS FROM 06
THROUGH 12Z THURSDAY.
OTHER SITES COULD EXPERIENCE WIDESPREAD MVFR/LOCAL IFR CIGS TO
LINGER THROUGH AT LEAST 15-16Z...WHEN GRADUAL LIFTING TO VFR AREA
WIDE IS EXPECTED.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z FRIDAY...
FORECAST CONFIDENCE: LOW.
ALTERNATE SCENARIOS: CIGS MAY LIFT TO VFR SOONER THAN FORECAST.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE THU
UTC 1HRLY 00 01 02 03 04 05 06 07 08 09 10 11
EST 1HRLY 19 20 21 22 23 00 01 02 03 04 05 06
CRW CONSISTENCY L L L L M M M M L L L L
HTS CONSISTENCY L L L L L L L L L L L M
BKW CONSISTENCY L L L L M M M M L L L L
EKN CONSISTENCY M M M M M M M M M M M L
PKB CONSISTENCY L L L L M M M M H H M M
CKB CONSISTENCY M M M M M M M M M M L L
AFTER 00Z FRIDAY...
IFR POSSIBLE SATURDAY AND SUNDAY IN RAIN AND SNOW SHOWERS.
&&
.EQUIPMENT...
PKB ASOS HAS BEEN EXPERIENCING MALFUNCTIONS...RESULTING IN SOME
MISSING OR INCOMPLETE OBSERVATIONS. TECHNICIANS ARE AWARE OF THE
PROBLEM AND PARTS ARE BEING ACQUIRED.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/50/SL
NEAR TERM...ARJ/SL
SHORT TERM...50
LONG TERM...KTB
AVIATION...ARJ
EQUIPMENT...ARJ
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1138 PM CST WED FEB 5 2014
.AVIATION...
/06Z TAFS/
CONCERNS...MVFR CIGS LATE TONIGHT AND THURSDAY MORNING IN THE
METROPLEX. CHANCE FOR LIGHT SNOW IN THE METROPLEX THURSDAY MORNING.
SOME MVFR CIGS WITH BASES 2000-2500 FEET ARE BEGINNING TO DEVELOP
IN THE METROPLEX. WILL PREVAIL A SCT025 FOR NOW BECOMING BKN025
AROUND 09Z. SOME OF THE MODELS CONTINUE TO INDICATE THAT THE BKN
DECK WILL REMAIN OVER TARRANT COUNTY WITH DALLAS COUNTY REMAINING
FEW-SCT AND WILL WATCH TRENDS OVERNIGHT. KACT IS EXPECTED TO
REMAIN IN VFR CONDITIONS BUT MAY HAVE BRIEF PERIODS OF BKN025
DURING THE NIGHT.
THERE IS STILL A CHANCE FOR LIGHT SNOW MOVING IN FROM THE WEST
THURSDAY MORNING...REACHING THE METROPLEX BETWEEN 14-15Z. SEVERAL
MODELS KEEP THE SNOW WEST OF THE METROPLEX EXCEPT FOR POSSIBLY
KAFW...SO DID NOT FEEL A NEED TO CHANGE THE CURRENT TAF TIMING AND
IMPACTS DUE TO LIGHT SNOW. CONDITIONS ARE EXPECTED TO IMPROVE
AROUND MIDDAY WITH WIND SPEEDS FINALLY DECREASING TO LESS THAN 10
KTS DURING THE AFTERNOON HOURS.
82/JLD
&&
.UPDATE...
CLOUDS AND MOISTURE WILL GRADUALLY INCREASE OVERNIGHT AS A
PRONOUNCED SHORTWAVE OVER NORTHERN MEXICO MOVES EAST INTO WEST-
CENTRAL TEXAS. MOISTURE LEVELS WILL REMAIN LIMITED WITH THIS
SYSTEM...BUT SUFFICIENT FOR LIGHT PRECIPITATION TO DEVELOP OVER
WESTERN COUNTIES OF NORTH TEXAS EARLY THURSDAY MORNING...THEN
SWEEP NORTHEAST ACROSS THE CENTRAL AND NORTHEASTERN COUNTIES LATE
MORNING THROUGH EARLY AFTERNOON. SUB-FREEZING TEMPERATURES AT ALL
ALTITUDES INDICATES THAT PRECIPITATION WILL FALL AS SNOW. THE MOST
RECENT MODEL OUTPUT FROM THIS EVENING REMAINS FAIRLY CONSISTENT
WITH EARLIER RUNS...INDICATING 1-2 INCHES OVER THE WESTERN-MOST
LOCALES...TAPERING OFF TO AROUND A QUARTER OR HALF AN INCH IN THE
DALLAS-FORT WORTH METROPLEX...TO A DUSTING FARTHER EAST. A WINTER
WEATHER ADVISORY WILL REMAIN IN EFFECT FROM 3 AM UNTIL 2 PM
THURSDAY FOR AREAS GENERALLY WEST OF AN EASTLAND TO JACKSBORO TO
BOWIE LINE. PRECIPITATION WILL COME TO AN END THURSDAY AFTERNOON AS
THE SHORTWAVE ACCELERATES EASTWARD INTO THE MISSISSIPPI VALLEY. AT
THIS TIME...IT APPEARS THAT MEASURABLE SNOWFALL WILL BE LIMITED TO
AREAS GENERALLY ALONG AND NORTHWEST OF A LINE FROM PARIS TO
COMANCHE...WHILE AREAS FARTHER SOUTH AND EAST MAY BE TOO FAR REMOVED
FROM THE UPPER LEVEL FEATURE TO RECEIVE MEASURABLE PRECIPITATION.
EITHER WAY...BITTER COLD CONDITIONS WILL BE EXPERIENCED AREA-WIDE
THROUGH TOMORROW AS TEMPERATURES PLUMMET INTO THE TEENS. A WIND CHILL
ADVISORY WILL REMAIN IN PLACE OVERNIGHT FOR AREAS ALONG AND NORTH
OF A LINE FROM CISCO TO WEATHERFORD TO MCKINNEY TO BONHAM. WE
WILL KEEP AN EYE ON PRECIPITATION TRENDS AS ACTIVITY UNFOLDS LATER
TONIGHT...AND ADJUST THE AREAS OF THE WINTER WEATHER ADVISORY IF
NEEDED. AT THIS TIME...THE FORECAST REMAINS IN GREAT SHAPE WITH NO
SIGNIFICANT UPDATES NEEDED.
30
&&
.PREV DISCUSSION... /ISSUED 346 PM CST WED FEB 5 2014/
VERY PROGRESSIVE UPPER PATTERN WILL KEEP NORTH TEXAS COLD WITH
SEVERAL CHANCES FOR AT LEAST LIGHT PRECIPITATION OVER THE UPCOMING
WEEK. WITH TEMPERATURES NOT EXPECTED TO MAKE IT ABOVE FREEZING
UNTIL SOMETIME FRIDAY...WINTRY PRECIPITATION REMAINS IN THE
FORECAST.
WATER VAPOR IMAGERY SHOWS STRONG SHORTWAVE NOW MAKING ITS WAY
ACROSS NORTHWEST MEXICO. RUC ANALYSIS OF THE DYNAMIC TROPOPAUSE
HAS CONSISTENTLY SUGGESTED THAT THIS FEATURE IS STRONGER THAN MOST
OF THE OTHER OPERATIONAL MODEL GUIDANCE IS INDICATING. THIS IS SUPPORTED
BY THE IMAGERY ITSELF WHICH SHOWS A COMPACT POTENT VORTEX DIGGING
ACROSS THE MEXICAN STATE OF SONORA. AS IT MOVES INTO THE BIG BEND
REGION LATER TONIGHT...SATURATION WILL TAKE PLACE FROM BOTH THE
TOP DOWN AND FROM LOW LEVEL WARM MOIST ADVECTION AS 850MB FLOW
VEERS IN RESPONSE TO APPROACHING SHORTWAVE. THE THERMAL PROFILE
ACROSS NORTH TEXAS WILL BE SUFFICIENTLY COLD TO SUPPORT ALL SNOW
SO PRECIP TYPE IS REALLY NOT IN QUESTION THIS TIME AROUND.
CROSS SECTION ANALYSIS FROM SOUTHWEST OKLAHOMA INTO NORTH CENTRAL
TEXAS INDICATES A DEEP SATURATED LAYER BY THURSDAY MORNING WITH
CONDITIONAL SYMMETRIC INSTABILITY PRESENT. AS FORCING INCREASES
LATE TONIGHT...AREAS OF SNOW ARE EXPECTED TO DEVELOP MAINLY ACROSS
THE WESTERN COUNTIES. SOME BANDING OF THE PRECIPITATION IS
POSSIBLE GIVEN THE PRESENCE OF INSTABILITY MENTIONED EARLIER AND
THIS HAS EVEN BEEN INDICATED IN THE LAST COUPLE OF RUNS OF THE 3KM
TTU WRF. WHILE QPF AMOUNTS ARE GENERALLY LIGHT ACROSS THE AREA...THE
COLD TEMPERATURES SHOULD SUPPORT SNOWFALL RATIOS OF GREATER THAN
10 TO 1. THIS ISNT TYPICAL FOR NORTH TEXAS AS WE USUALLY WIND UP
DEALING WITH HEAVY WET SNOW. BASED ON THE LATEST DATA...WE THINK 1
TO 2 INCHES OF SNOW WILL BE POSSIBLE ACROSS THE WESTERN COUNTIES
WITH LIGHTER AMOUNTS FARTHER EAST INTO THE METROPLEX. ALL OF THE
ACTIVITY SHOULD END QUICKLY BY MIDDAY OR SHORTLY THEREAFTER. A
WINTER WEATHER ADVISORY HAS BEEN ISSUED FOR THE FAR WESTERN
COUNTIES WHERE GREATEST ACCUMULATIONS ARE EXPECTED. IN
ADDITION...THE WIND CHILL ADVISORY WILL REMAIN UNCHANGED AS TEMPS
ARE EXPECTED TO FALL INTO THE LOW TO MID TEENS WITH GUSTY NORTH WINDS.
AS SOON AS THIS SYSTEM DEPARTS...ANOTHER IS QUICKLY ON ITS HEELS
FOR FRIDAY AND THIS COULD ACTUALLY BE THE DAY OF MORE SIGNIFICANT
WINTER WEATHER IMPACTS. COLD TEMPERATURES WILL REMAIN ENTRENCHED
ACROSS THE REGION WITH MOST AREAS IN THE LOW 20S EARLY FRIDAY
MORNING. SURFACE FLOW WILL WEAKEN AND VEER TO THE EAST DURING THE
DAY FRIDAY...BUT SOUTHERLY 850MB FLOW WILL BE ESTABLISHED BY THIS
TIME. LOW LEVEL MOISTURE AND WARM ADVECTION WILL BE SUFFICIENT FOR
LIGHT PRECIPITATION TO DEVELOP DURING THE DAY FRIDAY. ANALYSIS OF
FORECAST SOUNDINGS INDICATE A COUPLE OF SCENARIOS POSSIBLY PLAYING OUT.
THE LEAST FAVORABLE AT THIS TIME WOULD BE FOR A QUICK RETURN OF
MOISTURE AND WIDESPREAD SNOW TO DEVELOP DURING THE DAY. THIS SEEMS
UNLIKELY GIVEN THE LACK OF MORE SIGNIFICANT MOISTURE ALOFT...AND
MORE IMPORTANTLY LACK OF MOISTURE IN THE SNOW DENDRITIC GROWTH
ZONE. WHILE THERE WILL BE SUFFICIENT MOISTURE DOWN LOW...IT IS LIKELY
TO BE IN THE FORM OF SUPER COOLED WATER DROPLETS...WHICH LEADS TO
THE MORE LIKELY SCENARIO OF WIDESPREAD VERY LIGHT FREEZING RAIN OR
FREEZING DRIZZLE. WITH TEMPERATURES IN THE LOW TO MID 20S AND
GROUND TEMPERATURES SUFFICIENTLY COLD...ICE WOULD LIKELY RAPIDLY
DEVELOP. FOR NOW...CONFIDENCE IS LOW IN ANY PARTICULAR SOLUTION
BUT WILL HAVE 20 POPS FOR LIGHT FREEZING RAIN/DRIZZLE ON FRIDAY.
BEYOND FRIDAY...MODELS DIFFER WITH FRONTAL TIMING ON MONDAY WITH
THE ECMWF BRINGING A FRONT THROUGH AND GFS HOLDING OFF UNTIL
TUESDAY. THIS FORECAST PACKAGE WILL COMPROMISE BETWEEN THE TWO AND
SHOW INCREASING RAIN CHANCES FOR MON/TUE TIMEFRAME.
DUNN
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 17 27 20 35 28 / 10 50 5 20 10
WACO, TX 20 34 22 38 29 / 10 20 5 20 10
PARIS, TX 19 27 22 37 27 / 10 50 5 20 10
DENTON, TX 17 25 17 35 26 / 10 70 5 20 10
MCKINNEY, TX 16 27 18 34 26 / 10 50 5 20 10
DALLAS, TX 18 29 21 36 28 / 10 50 5 20 10
TERRELL, TX 20 30 21 37 28 / 10 30 5 20 10
CORSICANA, TX 21 35 25 38 30 / 10 20 5 20 10
TEMPLE, TX 22 35 22 39 31 / 10 10 5 20 10
MINERAL WELLS, TX 16 26 18 35 25 / 20 70 5 20 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 3 AM TO 2 PM CST THURSDAY FOR
TXZ091-100-101-115-116-129.
WIND CHILL ADVISORY FROM 3 AM TO NOON CST THURSDAY FOR
TXZ091>094-100>104-115>117-129-130.
&&
$$
82/30
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
530 PM CST WED FEB 5 2014
.AVIATION...
/00Z TAFS/
CONCERNS...MVFR CIGS LATE TONIGHT AND THURSDAY MORNING IN THE
METROPLEX. CHANCE FOR LIGHT SNOW IN THE METROPLEX THURSDAY MORNING.
THE CHALLENGES...IMPACTS...AND CONCERNS FOR THE NEXT 24-30 HOURS
FOCUS MORE ON THE METROPLEX AIRPORTS WITH KACT REMAINING IN VFR
STATUS. SOME OF THE MODELS ARE INDICATING A CHANCE FOR MVFR CIGS
AROUND 2500 FEET AT KACT OVERNIGHT...BUT THE MODELS ARE SUFFERING
WITH RESOLVING THE CURRENT CLOUD CONDITIONS AND DO NOT HAVE ENOUGH
CONFIDENCE AT THIS TIME TO BRING MVFR CIGS INTO WACO WITH THIS TAF
PACKAGE.
FOR THE METROPLEX...BEST GUESS ON MVFR CIGS AROUND 2500 FEET
ARRIVING IS 06Z. AS MENTIONED ABOVE...THE MODELS ARE SUFFERING
WITH CLOUD TRENDS TODAY AND GOING INTO THE EVENING HOURS...AND WILL
BE MONITORING FOR ANY NECESSARY AMENDMENTS. A POSSIBLE SCENARIO IS
THE MVFR CIGS ACROSS OKLAHOMA SPREAD SOUTH AND ARRIVE IN THE
METROPLEX BEFORE 06Z. SOME OF THE MODELS ALSO INDICATE THE
MVFR CIGS OVERNIGHT WILL MAINLY AFFECT THE WESTERN HALF OF THE
METROPLEX...INCLUDING KAFW AND KFTW.
THERE IS STILL A CHANCE FOR LIGHT SNOW MOVING IN FROM THE WEST
THURSDAY MORNING...REACHING THE METROPLEX BETWEEN 14-15Z. SEVERAL
MODELS KEEP THE SNOW WEST OF THE METROPLEX EXCEPT FOR POSSIBLY
KAFW...SO DID NOT FEEL A NEED TO CHANGE THE CURRENT TAF TIMING AND
IMPACTS DUE TO LIGHT SNOW. CONDITIONS ARE EXPECTED TO IMPROVE AROUND
MIDDAY WITH WIND SPEEDS FINALLY DECREASING TO LESS THAN 10 KTS
DURING THE AFTERNOON HOURS.
82/JLD
&&
.PREV DISCUSSION... /ISSUED 346 PM CST WED FEB 5 2014/
VERY PROGRESSIVE UPPER PATTERN WILL KEEP NORTH TEXAS COLD WITH
SEVERAL CHANCES FOR AT LEAST LIGHT PRECIPITATION OVER THE UPCOMING
WEEK. WITH TEMPERATURES NOT EXPECTED TO MAKE IT ABOVE FREEZING
UNTIL SOMETIME FRIDAY...WINTRY PRECIPITATION REMAINS IN THE
FORECAST.
WATER VAPOR IMAGERY SHOWS STRONG SHORTWAVE NOW MAKING ITS WAY
ACROSS NORTHWEST MEXICO. RUC ANALYSIS OF THE DYNAMIC TROPOPAUSE
HAS CONSISTENTLY SUGGESTED THAT THIS FEATURE IS STRONGER THAN MOST
OF THE OTHER OPERATIONAL MODEL GUIDANCE IS INDICATING. THIS IS SUPPORTED
BY THE IMAGERY ITSELF WHICH SHOWS A COMPACT POTENT VORTEX DIGGING
ACROSS THE MEXICAN STATE OF SONORA. AS IT MOVES INTO THE BIG BEND
REGION LATER TONIGHT...SATURATION WILL TAKE PLACE FROM BOTH THE
TOP DOWN AND FROM LOW LEVEL WARM MOIST ADVECTION AS 850MB FLOW
VEERS IN RESPONSE TO APPROACHING SHORTWAVE. THE THERMAL PROFILE
ACROSS NORTH TEXAS WILL BE SUFFICIENTLY COLD TO SUPPORT ALL SNOW
SO PRECIP TYPE IS REALLY NOT IN QUESTION THIS TIME AROUND.
CROSS SECTION ANALYSIS FROM SOUTHWEST OKLAHOMA INTO NORTH CENTRAL
TEXAS INDICATES A DEEP SATURATED LAYER BY THURSDAY MORNING WITH
CONDITIONAL SYMMETRIC INSTABILITY PRESENT. AS FORCING INCREASES
LATE TONIGHT...AREAS OF SNOW ARE EXPECTED TO DEVELOP MAINLY ACROSS
THE WESTERN COUNTIES. SOME BANDING OF THE PRECIPITATION IS
POSSIBLE GIVEN THE PRESENCE OF INSTABILITY MENTIONED EARLIER AND
THIS HAS EVEN BEEN INDICATED IN THE LAST COUPLE OF RUNS OF THE 3KM
TTU WRF. WHILE QPF AMOUNTS ARE GENERALLY LIGHT ACROSS THE AREA...THE
COLD TEMPERATURES SHOULD SUPPORT SNOWFALL RATIOS OF GREATER THAN
10 TO 1. THIS ISNT TYPICAL FOR NORTH TEXAS AS WE USUALLY WIND UP
DEALING WITH HEAVY WET SNOW. BASED ON THE LATEST DATA...WE THINK 1
TO 2 INCHES OF SNOW WILL BE POSSIBLE ACROSS THE WESTERN COUNTIES
WITH LIGHTER AMOUNTS FARTHER EAST INTO THE METROPLEX. ALL OF THE
ACTIVITY SHOULD END QUICKLY BY MIDDAY OR SHORTLY THEREAFTER. A
WINTER WEATHER ADVISORY HAS BEEN ISSUED FOR THE FAR WESTERN
COUNTIES WHERE GREATEST ACCUMULATIONS ARE EXPECTED. IN
ADDITION...THE WIND CHILL ADVISORY WILL REMAIN UNCHANGED AS TEMPS
ARE EXPECTED TO FALL INTO THE LOW TO MID TEENS WITH GUSTY NORTH WINDS.
AS SOON AS THIS SYSTEM DEPARTS...ANOTHER IS QUICKLY ON ITS HEELS
FOR FRIDAY AND THIS COULD ACTUALLY BE THE DAY OF MORE SIGNIFICANT
WINTER WEATHER IMPACTS. COLD TEMPERATURES WILL REMAIN ENTRENCHED
ACROSS THE REGION WITH MOST AREAS IN THE LOW 20S EARLY FRIDAY
MORNING. SURFACE FLOW WILL WEAKEN AND VEER TO THE EAST DURING THE
DAY FRIDAY...BUT SOUTHERLY 850MB FLOW WILL BE ESTABLISHED BY THIS
TIME. LOW LEVEL MOISTURE AND WARM ADVECTION WILL BE SUFFICIENT FOR
LIGHT PRECIPITATION TO DEVELOP DURING THE DAY FRIDAY. ANALYSIS OF
FORECAST SOUNDINGS INDICATE A COUPLE OF SCENARIOS POSSIBLY PLAYING OUT.
THE LEAST FAVORABLE AT THIS TIME WOULD BE FOR A QUICK RETURN OF
MOISTURE AND WIDESPREAD SNOW TO DEVELOP DURING THE DAY. THIS SEEMS
UNLIKELY GIVEN THE LACK OF MORE SIGNIFICANT MOISTURE ALOFT...AND
MORE IMPORTANTLY LACK OF MOISTURE IN THE SNOW DENDRITIC GROWTH
ZONE. WHILE THERE WILL BE SUFFICIENT MOISTURE DOWN LOW...IT IS LIKELY
TO BE IN THE FORM OF SUPER COOLED WATER DROPLETS...WHICH LEADS TO
THE MORE LIKELY SCENARIO OF WIDESPREAD VERY LIGHT FREEZING RAIN OR
FREEZING DRIZZLE. WITH TEMPERATURES IN THE LOW TO MID 20S AND
GROUND TEMPERATURES SUFFICIENTLY COLD...ICE WOULD LIKELY RAPIDLY
DEVELOP. FOR NOW...CONFIDENCE IS LOW IN ANY PARTICULAR SOLUTION
BUT WILL HAVE 20 POPS FOR LIGHT FREEZING RAIN/DRIZZLE ON FRIDAY.
BEYOND FRIDAY...MODELS DIFFER WITH FRONTAL TIMING ON MONDAY WITH
THE ECMWF BRINGING A FRONT THROUGH AND GFS HOLDING OFF UNTIL
TUESDAY. THIS FORECAST PACKAGE WILL COMPROMISE BETWEEN THE TWO AND
SHOW INCREASING RAIN CHANCES FOR MON/TUE TIMEFRAME.
DUNN
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 17 27 20 35 28 / 10 50 5 20 10
WACO, TX 20 34 22 38 29 / 10 20 5 20 10
PARIS, TX 19 27 22 37 27 / 10 50 5 20 10
DENTON, TX 17 25 17 35 26 / 10 70 5 20 10
MCKINNEY, TX 16 27 18 34 26 / 10 50 5 20 10
DALLAS, TX 18 29 21 36 28 / 10 50 5 20 10
TERRELL, TX 20 30 21 37 28 / 10 30 5 20 10
CORSICANA, TX 21 35 25 38 30 / 10 20 5 20 10
TEMPLE, TX 22 35 22 39 31 / 10 10 5 20 10
MINERAL WELLS, TX 16 26 18 35 25 / 20 70 5 20 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 3 AM TO 2 PM CST THURSDAY FOR
TXZ091-100-101-115-116-129.
WIND CHILL ADVISORY FROM 3 AM TO NOON CST THURSDAY FOR
TXZ091>094-100>104-115>117-129-130.
&&
$$
82/30
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1011 PM CST WED FEB 5 2014
.UPDATE...
ISSUED AT 807 PM CST WED FEB 5 2014
CLOUDS ARE DISSIPATING AND EXITING THE FORECAST AREA MUCH FASTER
THAN PREVIOUSLY FORECAST. HAVE BEEN UPDATING TRENDS OVER THE PAST
FEW HOURS TO ACCOUNT TO THE CLEARING TREND SEEN ON 11-3.9UM
IMAGERY AND OBSERVATIONS. APPEARS DIURNAL HEATING HAD A BIG
INFLUENCE ON THE CLOUD COVER THIS AFTERNOON...ESPECIALLY AROUND
AND WEST OF I-35 WHERE THOSE CLOUDS ARE NOW DISSIPATED. AS FAR AS
THE CLOUDS WRAPPING AROUND THE VORT CENTER IN NORTHEAST SOUTH
DAKOTA...THESE ARE MOVING VERY LITTLE. THEREFORE...THEY MAY NOT
EVEN GET HERE UNTIL WELL AFTER SUNRISE...IF AT ALL GIVEN THE TRACK
OF THE VORT EXPECTED TO STAY MOSTLY NORTH OF THE FORECAST AREA.
MUCH OF THE FLURRY ACTIVITY HAS FOLLOWED THE CLOUD TRENDS...
DISSIPATING QUICKLY BETWEEN 4-6 PM. ONLY AREA THAT STILL HAS
FLURRIES MENTIONED IS TAYLOR/CLARK COUNTIES. EVEN HERE...THE
FLURRIES MAY END BY MIDNIGHT.
WITH CLEARER SKIES TONIGHT...ATTENTION TURNS TO TEMPERATURES.
05.18Z NAM AND 05.23Z RAP INDICATE MUCH COLDER LOWS THAN
FORECAST...PARTICULARLY SOUTH OF I-90. COMPARING THEIR 1-3 HOURLY
FORECAST OUTPUT...THEY DO SEEM TO BE A BIT TOO COLD. HOWEVER...THE
IDEA OF A COLDER NIGHT SEEMS REASONABLE GIVEN THE CLEARER SKIES.
LOWERED LOWS A FEW DEGREES SOUTH OF INTERSTATE 90...AS WELL AS THE
BLACK RIVER FALLS/SPARTA AREA. NEEDLESS TO SAY THE COLDER
TEMPERATURES EASILY SUPPORTS THE GOING WIND CHILL ADVISORY.
&&
.SHORT TERM...(TONIGHT THROUGH THURSDAY NIGHT)
ISSUED AT 215 PM CST WED FEB 5 2014
FLURRIES TONIGHT AND BITTER COLD WIND CHILLS TONIGHT INTO THURSDAY
MORNING WILL BE THE MAIN FOCUS IN THE SHORT TERM.
WATER VAPOR IMAGERY SHOWING AN ELONGATED MID-LEVEL TROUGH EXTENDING
FROM WESTERN QUEBEC THROUGH SOUTHERN ONTARIO INTO THE NORTHERN
PLAINS. VERY LIGHT/NON-MEASURABLE SNOW CONTINUED TO LINGER ACROSS
THE FORECAST AREA UNDER THIS TROUGH/GENERAL CYCLONIC FLOW.
OTHERWISE...SKIES WERE CLOUDY ACROSS THE AREA WITH TEMPERATURES
BEING HELD IN CHECK IN THE SINGLE DIGITS AND TEENS ABOVE ZERO.
OF NOTE ON THE WATER VAPOR EMBEDDED WITHIN THE LONG WAVE TROUGH WAS A
VORTICITY MAXIMUM OVER EASTERN ND. THIS WAVE WILL WEAKEN AS IT MOVES
SOUTHEAST INTO THE AREA TONIGHT. NONETHELESS...MODELS SHOW A WING OF
WEAK WIND OF 700-300MB PV-ADVECTION MOVING THROUGH THE AREA AND IS
EXPECTED TO KEEP FLURRY ACTIVITY GOING THROUGH THE NIGHT. DESPITE
CLOUD COVER...EXPECTING TEMPERATURES TONIGHT INTO EARLY THURSDAY
MORNING TO FALL INTO -5 TO -11F RANGE. THESE TEMPERATURES COMBINED
WITH WINDS IN THE 6 TO 12 MPH RANGE WILL PRODUCE WIND CHILLS IN THE
-15 TO -30F RANGE. AS SUCH...A WIND CHILL ADVISORY REMAINS IN EFFECT
TONIGHT THROUGH NOON THURSDAY.
WILL LIKELY NEED ANOTHER WIND CHILL ADVISORY HEADLINE FOR THURSDAY
NIGHT INTO FRIDAY MORNING AS WELL. LOOK FOR TEMPERATURES TO FALL
INTO THE -5 TO -15F RANGE AND WEST/SOUTHWEST WINDS BLOWING AROUND 7-
15 MPH ON THE BACKSIDE OF HIGH PRESSURE SLIDING SOUTH OF THE AREA.
THIS IS EXPECTED TO PRODUCE BITTER COLD WIND CHILL VALUES IN THE -15
TO -30F RANGE.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 215 PM CST WED FEB 5 2014
FRIDAY THROUGH SATURDAY NIGHT:
AFTER THE BITTER COLD WIND CHILLS THROUGH FRIDAY MORNING...ATTENTION
THEN TURNS TO A FAIRLY VIGOROUS MID-LEVEL TROUGH ROTATING OUT OF THE
PLAINS AND ACROSS THE AREA FRIDAY NIGHT/SATURDAY. THIS SIGNAL HAS
BEEN GETTING MORE CONSISTENT BETWEEN THE MODELS AND FROM RUN-TO-
RUN. FURTHER ANALYSIS WITH THE NAM/GFS SHOWS DECENT 700-300MB PV-
ADVECTION ASSOCIATED WITH THE WAVE ALONG WITH FAIRLY STRONG 275K
ISENTROPIC LIFT INTO THE REGION FROM LATE FRIDAY NIGHT/AFTER
MIDNIGHT...THROUGH SATURDAY. BASED ON THIS...HAVE PUSHED POPS INTO
THE LIKELY CATEGORY CENTERED ON DURING THE DAY SATURDAY. RIGHT
NOW...IT APPEARS A BROAD AREA OF 1.5-2.5 INCHES IS EXPECTED WITH THE
HEAVIEST AMOUNTS ALONG AND SOUTH OF I-90. 12Z MODELS HAVE THIS WAVE
PUSHING EAST OF THE AREA SATURDAY EVENING WITH PERHAPS SOME
LINGERING LIGHT SNOW ACROSS PORTIONS OF NORTHEAST IA INTO CENTRAL
WI. TEMPERATURE-WISE...HIGHS SATURDAY EXPECTED TO TOP OFF IN THE
TEENS WITH LOWS SATURDAY NIGHT DIPPING BACK DOWN INTO THE SINGLE
DIGITS EITHER SIDE OF ZERO.
SUNDAY THROUGH WEDNESDAY:
12Z ECMWF/GFS STARTING TO INDICATE SOME WEAKENING/BREAKING DOWN OF
THE RIDGE OFF THE WEST COAST FOR SUNDAY THROUGH WEDNESDAY. MODIFIED
WEST/NORTHWEST FLOW ALOFT STEERS PRECIPITATING PRECIPITATION WAVES
SOUTH OF THE AREA WITH OUR AREA REMAINING DRY THROUGH THE PERIOD.
ALSO...LOOKS LIKE SOME MODERATION IN TEMPERATURE AS WELL AS ARCTIC
AIR IS HELD NORTH OF THE CANADIAN BORDER WITH RETREAT OF THE POLAR
VORTEX. LOOKING FOR HIGHS STARTING OFF SUNDAY IN THE SINGLE
DIGITS/TEENS ABOVE ZERO...MODERATING SLOWLY INTO THE UPPER
TEENS/MIDDLE 20S BY WEDNESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1011 PM CST WED FEB 5 2014
SKIES HAVE CLEARED OUT AT THE TAF SITES RESULTING FROM THE LOSS OF
DAYTIME HEATING AND DRIER AIR FLOWING IN FROM THE WEST.
ANTICIPATING VFR CONDITIONS TO CONTINUE THROUGH THURSDAY NIGHT AS
A FLOW OF DRY...ARCTIC AIR PERSISTS. THERE COULD BE SOME SCATTERED
DAYTIME STRATOCUMULUS WITH MVFR CEILINGS AT RST...BUT BELIEVE
ENOUGH DRY AIR SHOULD BE PRESENT TO PRECLUDE THE CLOUDS FROM GOING
TO BROKEN. A NORTHWEST TO WEST 5-15 KT BREEZE WILL PERSIST AS WELL
AT BOTH TAF SITES...WITH THE STRONGEST WINDS OCCURRING DURING THE
MID TO LATE AFTERNOON HOURS AT THE TIME OF PEAK HEATING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WIND CHILL ADVISORY UNTIL NOON CST THURSDAY FOR WIZ017-029-
032>034-041>044-053>055-061.
MN...WIND CHILL ADVISORY UNTIL NOON CST THURSDAY FOR MNZ086-087-094-
095.
WIND CHILL ADVISORY UNTIL NOON CST THURSDAY FOR MNZ079-088-096.
IA...WIND CHILL ADVISORY UNTIL NOON CST THURSDAY FOR IAZ008>010-018-
019-029.
WIND CHILL ADVISORY UNTIL NOON CST THURSDAY FOR IAZ011-030.
&&
$$
UPDATE...AJ
SHORT TERM...DAS
LONG TERM....DAS
AVIATION...AJ
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
852 PM CST WED FEB 5 2014
.UPDATE...
SKY COVER AND RELATED TEMPERATURES PROBLEMATIC OVERNIGHT. SKIES
CLEARED OUT A BIT FASTER THAN EXPECTED ESPECIALLY OVER SOUTHWEST
AND THESE CLEAR SKIES STRETCH ACROSS IOWA. MADE ADJUSTMENTS TO
LOWER SKY COVER MUCH OF THE NIGHT INTO THURSDAY...GENERALLY
FOLLOWING LATEST RAP SKY COVER GUIDANCE.
LAST FEW RUNS OF THE RAP WOULD INDICATE...IF CORRECT...THAT OUR
LOW TEMPERATURE FORECAST NEEDS TO BE LOWERED 10 DEGREES. GIVEN
THAT WE HAVE SEEN A COLD BIAS WITH THIS MODEL AND MANY OTHER
MODELS FOR THAT MATTER THIS WINTER...OUR GOING FORECAST IS
PROBABLY OK.
THAT SAID...RECENT TEMPERATURE TRENDS HAVE PRETTY MUCH MATCHED THE
FALL PREDICTED BY THE RAP. THERE ARE A FEW SPOTS IN SOUTHERN
MINNESOTA AND NORTHERN IOWA THAT HAVE FALLEN INTO THE -5 TO -10F
RANGE ALREADY. THE 18Z NAM...WHICH WAS THE CLOSEST LARGE SCALE
MODEL IN REPRESENTING 00Z TEMPERATURES...WAS PREDICTING WESTERN
SITES TO BE AROUND 0F BY 06Z. PVB AND DBQ WERE ALREADY ABOUT 2F AT
03Z...SO WE MAY NEED TO LOWER VALUES FURTHER.
THE WIND CHILL ADVISORY LOOKS GOOD FOR THE WESTERN TWO-THIRDS AS
THE TREND WOULD BE FOR COLDER VALUES IF ANYTHING.
&&
.AVIATION/06Z TAFS/...
CLOUD DECKS VANISHED DURING THE EVENING FASTER THAN SHOWN ON
RAP...NAM...GFS TIME SECTIONS. SIGNIFICANT DRYING SHOWN AFTER
06Z-09Z ABOVE 850 MB...BUT SATELLITE SHOWS LARGE AREAS OF CLEAR
SKIES FROM SOUTHERN WISCONSIN OVER INTO IOWA. THERE ARE PATCHES OF
VFR TO MVFR CEILINGS OVER NORTHERN ILLINOIS THAT MAY CLIP KENW BUT
THAT WOULD ONLY BRIEFLY IMPACT TAF SITE.
OTHERWISE LOOKS VFR WITH LIGHT WEST WINDS NEXT 24 HOURS.
&&
.PREV DISCUSSION... /ISSUED 332 PM CST WED FEB 5 2014/
TONIGHT - CONFIDENCE...MEDIUM
LINGERING LOW TO MID LEVEL RH ASSOCIATED WITH UPSTREAM WEAKER
SHORTWAVE MOVING EWD THROUGH MN TO NEAR KMPX BY 12Z. VERY LIGHT RETURNS
SHOWING UP ON RADAR MOSAIC. WILL PUT IN ISOLD FLURRIES. THE CLOUDS WILL
HOLD UP TEMPS A BIT IN THE ADVISORY AREA. SOME CLEARING EXPECTED
LATER THIS EVENING...SEEING SOME OF THIS ACROSS CNTRL IA. OVERNIGHT
LOWS DIP TO BETWEEN 6 AND 12 BELOW ACROSS THE ADVISORY AREA. ALSO GETTING
SOME WCI/S DIPPING TO AROUND 20 BELOW A BIT FURTHER EAST SO ADDED ANOTHER
TIER OF COUNTIES. THIS BLENDS WITH KLOT.
THURSDAY - CONFIDENCE...HIGH
BITTERLY COLD START TO THE DAY WITH NOT A GREAT DEAL OF RECOVERY.
SHORTWAVE SHEARS OUT INTO LOWER MICHIGAN. LIKELY TO STILL BE A FAIR
AMOUNT OF CLOUDS AROUND WITH THIS FEATURE. 925 TEMPS -18 TO -20C.
LOW LEVEL COLD ADVECTION ON A DRY NORTHWEST FLOW. TEMPS WILL STRUGGLE
THROUGH THE SINGLE DIGITS.
SHORT TERM...THURSDAY NIGHT THROUGH SATURDAY
THURSDAY NIGHT AND FRIDAY...FORECAST CONFIDENCE HIGH.
WE STAY ON THE NORTH/COLD/SIDE OF UPPER JET...AND UNDER SUBSIDENCE
OF LEFT ENTRANCE REGION OF DEPARTING UPPER JET MAX...WITH A
BROAD...FLAT UPPER TROUGH OVER THE REGION INTO SATURDAY. CHANNEL OF
SHEARED VORTICITY STRETCHES ALONG WI/IL BORDER...BUT LACK OF
MOISTURE MAKES IT HARD TO SEE MUCH MORE THAN SOME CIRRUS WITH THIS
FEATURE
925/850 MB COLD POCKETS IN PLACE OVER SRN WI THURSDAY NIGHT...WITH
TEMPERATURES A FEW DEGREES COLDER THAN TONIGHT...ESPECIALLY IN THE
EASTERN HALF OF THE CWA. THOUGH SURFACE PRESSURE GRADIENT OVER
REGION NOT AS TIGHT AS TONIGHT STILL ENOUGH WIND TO BRING ANOTHER
NIGHT WITH WIND CHILL ADVISORIES AS WIND CHILL VALUES DIP TO
-20 TO -25 OVER MOST OF THE CWA OVERNIGHT TO MID-MORNING FRIDAY.
WARM AIR ADVECTION ON DEVELOPING SWLY FLOW AS COLD HIGH SLIDES EAST
RAISING 925MB TEMPS 4C TO 5C BY 00Z SATURDAY WITH HIGHS FRIDAY
REACHING THE TEENS ABOVE ZERO...STILL AROUND 15 DEGREES BELOW
NORMAL.
FRIDAY NIGHT AND SATURDAY...FORECAST CONFIDENCE MEDIUM.
SOME MODEL DIFFERENCES ON TIMING OF POTENT SHORT WAVE AND ASSOCIATED
PRECIPITATION RIDING INTO THE AREA WITH NEXT UPPER JET MAX.
ECMWF/NAM/GFS BRING ISENTROPIC LIFT AND FULL COLUMN SATURATION INTO
THE FAR WEST JUST BEFORE/AT 12Z SATURDAY...WITH SOME DYNAMIC LIFT
FROM DIFFERENTIAL CVA WITH A WEAK LEAD VORT MAX. THE GEM SLOWER WITH
THE WAVE AND SNOW. CONSENSUS POPS FOLLOW THE BETTER LAYER Q-VECTOR
CONVERGENCE AND FRONTOGENETIC RESPONSE ON THE FASTER MODELS...WITH
THE POSSIBILITY OF A DOUBLE-BARREL SNOW EVENT WITH THE INITIAL WARM
ADVECTION SNOW IN THE MORNING...THEN THE DCVA-DRIVEN SNOW WITH THE
SHORT WAVE IN THE AFTERNOON. WHILE TEMPS DO RISE WITH THE WARM AIR
ADVECTION 925-850MB BAROCLINIC RIBBON HANGS UP IN NRN IL...OR NEAR
THE WI/IL BORDER. LOWS FRIDAY NIGHT COOL INTO THE SINGLE DIGITS
BELOW AROUND MIDNIGHT THEN STEADY OUT. HIGHS SATURDAY 15F TO 20F.
LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY. FORECAST CONFIDENCE
MEDIUM.
SNOW LINGERS INTO SATURDAY EVENING THEN HIGH PRESSURE BUILDS IN FOR
THE FIRST PART OF NEXT WEEK WITH BELOW NORMAL TEMPERATURES
CONTINUING. WEAK SHORT WAVES PASS MAINLY NORTH SUNDAY AND TUESDAY
THOUGH COULD BRUSH FORECAST AREA WITH CLOUDS AND FLURRIES. NEXT
CHANCE FOR MEASURABLE PRECIPITATION WILL COME NEXT WEDNESDAY
NIGHT/THURSDAY.
AVIATION/00Z TAFS/...SURFACE LOW CONTINUES TO PULL AWAY FROM THE
AREA. PRESSURE GRADIENT RELAXING A BIT. LOW LEVEL COLD ADVECTION
PERSISTS INTO THU MRNG. ANOTHER SHORTWAVE IN THE FLOW APPROACHES
LATER TNGT INTO THU. LOW LEVEL RH PROGS KEEP CLOUD COVER AROUND. MOS
SUGGESTS SOME MVFR CIGS TONIGHT AND THEN MOSTLY VFR THU. ANY SNSH
ACTIVITY WILL BE PATCHY AND LIGHT...MAINLY JUST FLURRIES.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...WIND CHILL ADVISORY FROM 3 AM TO 10 AM CST THURSDAY FOR WIZ046-
047-056>058-062>064-067>070.
LM...NONE.
&&
$$
UPDATE...CRAVEN
TONIGHT/THURSDAY AND AVIATION/MARINE...COLLAR
THURSDAY NIGHT THROUGH WEDNESDAY...REM
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
807 PM CST WED FEB 5 2014
.UPDATE...
ISSUED AT 807 PM CST WED FEB 5 2014
CLOUDS ARE DISSIPATING AND EXITING THE FORECAST AREA MUCH FASTER
THAN PREVIOUSLY FORECAST. HAVE BEEN UPDATING TRENDS OVER THE PAST
FEW HOURS TO ACCOUNT TO THE CLEARING TREND SEEN ON 11-3.9UM
IMAGERY AND OBSERVATIONS. APPEARS DIURNAL HEATING HAD A BIG
INFLUENCE ON THE CLOUD COVER THIS AFTERNOON...ESPECIALLY AROUND
AND WEST OF I-35 WHERE THOSE CLOUDS ARE NOW DISSIPATED. AS FAR AS
THE CLOUDS WRAPPING AROUND THE VORT CENTER IN NORTHEAST SOUTH
DAKOTA...THESE ARE MOVING VERY LITTLE. THEREFORE...THEY MAY NOT
EVEN GET HERE UNTIL WELL AFTER SUNRISE...IF AT ALL GIVEN THE TRACK
OF THE VORT EXPECTED TO STAY MOSTLY NORTH OF THE FORECAST AREA.
MUCH OF THE FLURRY ACTIVITY HAS FOLLOWED THE CLOUD TRENDS...
DISSIPATING QUICKLY BETWEEN 4-6 PM. ONLY AREA THAT STILL HAS
FLURRIES MENTIONED IS TAYLOR/CLARK COUNTIES. EVEN HERE...THE
FLURRIES MAY END BY MIDNIGHT.
WITH CLEARER SKIES TONIGHT...ATTENTION TURNS TO TEMPERATURES.
05.18Z NAM AND 05.23Z RAP INDICATE MUCH COLDER LOWS THAN
FORECAST...PARTICULARLY SOUTH OF I-90. COMPARING THEIR 1-3 HOURLY
FORECAST OUTPUT...THEY DO SEEM TO BE A BIT TOO COLD. HOWEVER...THE
IDEA OF A COLDER NIGHT SEEMS REASONABLE GIVEN THE CLEARER SKIES.
LOWERED LOWS A FEW DEGREES SOUTH OF INTERSTATE 90...AS WELL AS THE
BLACK RIVER FALLS/SPARTA AREA. NEEDLESS TO SAY THE COLDER
TEMPERATURES EASILY SUPPORTS THE GOING WIND CHILL ADVISORY.
&&
.SHORT TERM...(TONIGHT THROUGH THURSDAY NIGHT)
ISSUED AT 215 PM CST WED FEB 5 2014
FLURRIES TONIGHT AND BITTER COLD WIND CHILLS TONIGHT INTO THURSDAY
MORNING WILL BE THE MAIN FOCUS IN THE SHORT TERM.
WATER VAPOR IMAGERY SHOWING AN ELONGATED MID-LEVEL TROUGH EXTENDING
FROM WESTERN QUEBEC THROUGH SOUTHERN ONTARIO INTO THE NORTHERN
PLAINS. VERY LIGHT/NON-MEASURABLE SNOW CONTINUED TO LINGER ACROSS
THE FORECAST AREA UNDER THIS TROUGH/GENERAL CYCLONIC FLOW.
OTHERWISE...SKIES WERE CLOUDY ACROSS THE AREA WITH TEMPERATURES
BEING HELD IN CHECK IN THE SINGLE DIGITS AND TEENS ABOVE ZERO.
OF NOTE ON THE WATER VAPOR EMBEDDED WITHIN THE LONG WAVE TROUGH WAS A
VORTICITY MAXIMUM OVER EASTERN ND. THIS WAVE WILL WEAKEN AS IT MOVES
SOUTHEAST INTO THE AREA TONIGHT. NONETHELESS...MODELS SHOW A WING OF
WEAK WIND OF 700-300MB PV-ADVECTION MOVING THROUGH THE AREA AND IS
EXPECTED TO KEEP FLURRY ACTIVITY GOING THROUGH THE NIGHT. DESPITE
CLOUD COVER...EXPECTING TEMPERATURES TONIGHT INTO EARLY THURSDAY
MORNING TO FALL INTO -5 TO -11F RANGE. THESE TEMPERATURES COMBINED
WITH WINDS IN THE 6 TO 12 MPH RANGE WILL PRODUCE WIND CHILLS IN THE
-15 TO -30F RANGE. AS SUCH...A WIND CHILL ADVISORY REMAINS IN EFFECT
TONIGHT THROUGH NOON THURSDAY.
WILL LIKELY NEED ANOTHER WIND CHILL ADVISORY HEADLINE FOR THURSDAY
NIGHT INTO FRIDAY MORNING AS WELL. LOOK FOR TEMPERATURES TO FALL
INTO THE -5 TO -15F RANGE AND WEST/SOUTHWEST WINDS BLOWING AROUND 7-
15 MPH ON THE BACKSIDE OF HIGH PRESSURE SLIDING SOUTH OF THE AREA.
THIS IS EXPECTED TO PRODUCE BITTER COLD WIND CHILL VALUES IN THE -15
TO -30F RANGE.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 215 PM CST WED FEB 5 2014
FRIDAY THROUGH SATURDAY NIGHT:
AFTER THE BITTER COLD WIND CHILLS THROUGH FRIDAY MORNING...ATTENTION
THEN TURNS TO A FAIRLY VIGOROUS MID-LEVEL TROUGH ROTATING OUT OF THE
PLAINS AND ACROSS THE AREA FRIDAY NIGHT/SATURDAY. THIS SIGNAL HAS
BEEN GETTING MORE CONSISTENT BETWEEN THE MODELS AND FROM RUN-TO-
RUN. FURTHER ANALYSIS WITH THE NAM/GFS SHOWS DECENT 700-300MB PV-
ADVECTION ASSOCIATED WITH THE WAVE ALONG WITH FAIRLY STRONG 275K
ISENTROPIC LIFT INTO THE REGION FROM LATE FRIDAY NIGHT/AFTER
MIDNIGHT...THROUGH SATURDAY. BASED ON THIS...HAVE PUSHED POPS INTO
THE LIKELY CATEGORY CENTERED ON DURING THE DAY SATURDAY. RIGHT
NOW...IT APPEARS A BROAD AREA OF 1.5-2.5 INCHES IS EXPECTED WITH THE
HEAVIEST AMOUNTS ALONG AND SOUTH OF I-90. 12Z MODELS HAVE THIS WAVE
PUSHING EAST OF THE AREA SATURDAY EVENING WITH PERHAPS SOME
LINGERING LIGHT SNOW ACROSS PORTIONS OF NORTHEAST IA INTO CENTRAL
WI. TEMPERATURE-WISE...HIGHS SATURDAY EXPECTED TO TOP OFF IN THE
TEENS WITH LOWS SATURDAY NIGHT DIPPING BACK DOWN INTO THE SINGLE
DIGITS EITHER SIDE OF ZERO.
SUNDAY THROUGH WEDNESDAY:
12Z ECMWF/GFS STARTING TO INDICATE SOME WEAKENING/BREAKING DOWN OF
THE RIDGE OFF THE WEST COAST FOR SUNDAY THROUGH WEDNESDAY. MODIFIED
WEST/NORTHWEST FLOW ALOFT STEERS PRECIPITATING PRECIPITATION WAVES
SOUTH OF THE AREA WITH OUR AREA REMAINING DRY THROUGH THE PERIOD.
ALSO...LOOKS LIKE SOME MODERATION IN TEMPERATURE AS WELL AS ARCTIC
AIR IS HELD NORTH OF THE CANADIAN BORDER WITH RETREAT OF THE POLAR
VORTEX. LOOKING FOR HIGHS STARTING OFF SUNDAY IN THE SINGLE
DIGITS/TEENS ABOVE ZERO...MODERATING SLOWLY INTO THE UPPER
TEENS/MIDDLE 20S BY WEDNESDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 554 PM CST WED FEB 5 2014
COMPLICATED CLOUD FORECAST TONIGHT AS MVFR TO VFR STRATUS IS
MIXED WITH SOME DIURNALLY DRIVEN CLOUDS TO THE WEST. IN THE LAST
HOUR...OBSERVATIONS ACROSS CENTRAL/SOUTHERN MN HAVE BEEN SCATTERING
OUT. IT IS HIT OR MISS...BUT THINKING THE TREND THIS EVENING INTO
THE OVERNIGHT WILL BE MORE CLEARING / SCATTERING THAN BROKEN. IT
WILL HAVE TO BE CLOSELY WATCHED TO SEE WHAT REMAINS WELL AFTER
SUNSET. AS FAR AS FLURRIES...SAME IDEA THAT A LOT OF ACTIVITY WAS
DIURNAL AND HAS SUBSIDED QUITE A BIT IN THE LAST HOUR. SO HAVE
REMOVED VCSH GROUP FROM TAF. TOWARD THURSDAY
AFTERNOON...SCATTERING TO BROKEN CLOUDS WILL REMAIN IN PLACE AS
SOUNDINGS SHOW LOW LEVEL LAPSE RATES ARE STEEP ENOUGH TO PROMOTE
MORE DIURNAL CLOUDS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST THURSDAY
FOR WIZ017-029-032>034-041>044-053>055-061.
MN...WIND CHILL ADVISORY UNTIL NOON CST THURSDAY FOR MNZ086-087-094-
095.
WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST THURSDAY
FOR MNZ079-088-096.
IA...WIND CHILL ADVISORY UNTIL NOON CST THURSDAY FOR IAZ008>010-018-
019-029.
WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST THURSDAY
FOR IAZ011-030.
&&
$$
UPDATE...AJ
SHORT TERM...DAS
LONG TERM....DAS
AVIATION...ZT
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
431 AM PST Thu Feb 6 2014
.Synopsis...
Series of moist Pacific storms will impact Interior Northern
California today through early next week bringing rain...snow in
the mountains...and breezy to windy conditions at times.
&&
.Discussion...
Satellite imagery showing short wave trough rotating around large
scale polar low and across the CWA this morning with light to
moderate returns on Mosaic base reflectivity. Rainfall amounts
generally around around a third of an inch or less in the
Sacramento Valley overnight with lighter amounts to the north.
Light snow has been observed in the Shasta mountains and Coastal
range and in the Sierra Nevada. Snow levels currently around 2000
to 3000 feet. System on satellite appears to be moving faster than
06z progs are showing and latest HRRR suggesting precip will be
decreasing by late morning into early afternoon with lingering
showers...mainly over southern portions of the forecast area where
dynamics and moisture are better focused.
Light shower threat looks to continue tonight...mainly over the
mountains...then large atmospheric river extending from the
tropics takes aim on NorCal. WAA precip and large scale
isentropic lift increases over western portions of the CWA Friday
morning then spreads over the entire CWA during the day. Models
indicating periods of moderate to heavy precip Friday night
through the weekend as the concentrated moisture plume slowly sags
southward through Interior NorCal. Low snow levels in the
foothills will continue Friday morning but will gradually
rise to above 6000 feet by Saturday evening and near pass levels
Sunday into Monday. Winter storm watch has been expanded to
include the Coastal mountains for Friday into Saturday. Models
continue to showing significantly different QPF totals through the
weekend with oper GFS indicating upwards of 6 to 7 inches of
liquid precip in the Sierra while the ECMWF-HiRes is a little less
than half that amount. QPFs are in better agreement in the Central
Valley where upwards of 1 to 2 inches likely.
PCH
.Extended Discussion (Monday through Thursday)
Precipitation tapers off on Monday as temporary upper ridging
slides over the west coast. ECMWF a little slower clearing out
last in series of weekend systems so left in slight threat pops on
Monday with highest pops over Sierra closest to departing system.
Extended models all flatten west coast ridge quickly next Tuesday
as next Pacific frontal system pushes into the Pacific Northwest
bringing slight chances of precipitation to the northern most
portions of the state. Relatively flat ridging over the west coast
will allow a couple more slightly stronger Pacific systems to move
into the region Wednesday and Thursday. Precipitation amounts
will be limited due to general ridging over the area but most of
CWA will see a threat of precipitation. Despite cloud cover and
occasional precipitation...Daytime highs throughout the extended
period are expected to remain several degrees above normal with
moderate to high snow levels under moderately warm airmass.
&&
.Aviation...
Frontal passage through northern California today will bring MVFR/IFR
ceilings and visibility in light rain to the valley with IFR
conditions at the higher elevations in rain and snow. Snow levels
2500 to 3500 feet. Secondary shortwave trough will bring MVFR most
areas overnight with light rain/snow mainly north of interstate
80. Mainly south winds to 15 knots lower elevations with gusts to
40 knots highest elevations.
&&
.STO Watches/Warnings/Advisories...
Winter Storm Watch from Friday afternoon through Saturday evening
above 5000 feet in the west slope Northern Sierra Nevada...Western
Plumas county/Lassen park.
Winter Weather Advisory until 10 pm pst this evening above 4000
feet in the west slope Northern Sierra Nevada.
Winter Storm Watch from Friday afternoon through Saturday
afternoon above 4000 feet in the mountains southwestern Shasta
county to northern Lake county.
Winter Storm Watch from Friday afternoon through Saturday evening
for Shasta Lake area/Western Shasta county.
&&
$$
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
1020 AM EST THU FEB 6 2014
.UPDATE (REST OF TODAY AND TONIGHT)...
15Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS A RATHER UNAMPLIFIED UPPER
LEVEL PATTERN OVER THE CONUS...HIGHLIGHTED BY WEAK RIDGING ALONG
BOTH THE PACIFIC AND ATLANTIC COASTS AND SUBTLE TROUGHING THROUGH
THE CENTRAL PLAINS/MS VALLEY. ONE MORE SIGNIFICANT SHORTWAVE MOVING
ACROSS TEXAS/NORTHERN MEXICO THROUGH THE BASE OF THE LONGWAVE TROUGH
SHOWS A DEFINED SUBSIDENCE/DRYING PATTERN IN ITS WAKE. THIS FEATURE
WILL QUICKLY TRANSLATE EASTWARD AND HAVE A GLANCING INFLUENCE ON THE
FORECAST FOR THE FL PENINSULA LATER TODAY INTO TONIGHT AS IT BEGINS
TO SHEAR OUT AND PASS TO OUR NORTH. UPSTREAM 06/12Z SOUNDING PROFILE
FROM KTBW SHOWS A SPLIT COLUMN FEATURING A MOIST ENVIRONMENT BELOW A
WEAK 500MB SUBSIDENCE INVERSION...AND MUCH DRIER AIR FOR THE
REMAINDER OF THE TROP. THE MOIST LOWER LEVELS LEAD TO A HIGH OVERALL
PW FOR THIS PROFILE AROUND 1.56". THIS VALUE IS APPROACHING 2
STANDARD DEVIATIONS ABOVE CLIMATOLOGY FOR EARLY FEBRUARY.
AT THE SURFACE...A COLD FRONT PASSED THROUGH THE REGION LAST
NIGHT AND IS NOW QUASI-STATIONARY OVER THE SOUTH-CENTRAL FLORIDA
PENINSULA. SEEING A BIG DEWPOINT GRADIENT ACROSS THE BOUNDARY THIS
MORNING WITH VALUES IN THE 30S AND 40S APPROACHING THE I-10
CORRIDOR...AND UPPER 60S TO LOWER 70S DOWN BY LAKE OKEECHOBEE.
UNLIKE MANY FRONT WE SEE...WHERE SKIES CLEAR AND RAIN CHANCES END
AFTER THE FRONTAL PASSAGE (KATAFRONT)...THIS PATTERN IS KNOWS AS
ANAFRONT...AND IS HIGHLIGHTED BY CONDITIONS SUPPORTING CLOUDS AND
SHOWERS WITHIN THE POST-FRONTAL ENVIRONMENT. THIS IS WHAT WE ARE
SEEING THIS MORNING WITH NUMEROUS WEST TO EAST MOVING SHOWER
CLUSTERS...GENERALLY TO THE NORTH OF I-4. THESE SHOWERS ARE BEING
SUPPORTED BY A WEAK ISENTROPIC UPGLIDE REGIME WITHIN THE 300-305K
SURFACES AND A BROAD SPEED DIVERGENCE REGIME WITHIN THE MID LEVELS
OF THE TROP.
REST OF TODAY THROUGH THIS EVENING...THE OVERALL SYNOPTIC PATTERN AND
LIFTING MECHANISMS WILL HOLD IN PLACE ALONG AND NORTH OF THE I-4
CORRIDOR...KEEPING RAIN CHANCES RATHER HIGH. IF ANYTHING...THE UPPER
JET SUPPORT OVER THE NORTHERN PENINSULA INCREASES WITH TIME...ALONG
WITH AN SLOW INCREASE IN SYNOPTIC SUPPORT/QVECTOR CONVERGENCE
ASSOCIATED WITH THE SHORTWAVE APPROACHING AND PASSING TO OUR NORTH.
SOUTH OF THE I-4 CORRIDOR...THE LARGER SCALE LIFT WILL BE MUCH
WEAKER. HOWEVER...WHAT WE DO HAVE DOWN SOUTH IS LOW LEVEL FRONTAL
BOUNDARY FOCUS FOR MORE CONVECTIVE TYPE SHOWERS/STORMS LATER TODAY
ONCE DIURNAL HEATING HAS HAD A CHANCE. THE BEST CHANCES FOR THESE
LATER DAY STORMS WILL BE DOWN BY THE FRONT IN OKEECHOBEE...ST
LUCIE...AND MARTIN COUNTIES. THIS ACTIVITY WILL SUBSIDE WITH SUNSET
AND THE LOSS OF TERRESTRIAL HEATING...BUT THE BANDS OF SHOWERS OVER
THE NORTH LOOK TO CONTINUE BEING FEATURED IN THE FORECAST THROUGH AT
LEAST THE EVENING HOURS.
BEHIND THE FRONT WITH ALL THE CLOUDS/SHOWERS...WE WILL SEE A BIG
TEMPERATURE GRADIENT THROUGH THE DAY. THIS WILL BE AMPLIFIED BY
LOCAL WET-BULB EFFECTS ACROSS THE NORTHERN COUNTIES AS THE LIGHT
RAIN FALLS INTO A CONSTANT SUPPLY OF DRIER DEWPOINT AIR FROM THE
NORTH. CURRENT GRIDS SHOW HIGH TEMPERATURES UP TOWARD VOLUSIA AND
LAKE COUNTIES STRUGGLING INTO THE LOWER 60S...AND THEN RANGING UP
INTO THE MID/UPPER 70S ACROSS THE FAR SOUTH. THIS GRADIENT SEEMS
REASONABLE...AND DO NOT ANTICIPATE MUCH CHANGE NEEDED TO THIS PART
OF THE FORECAST.
SYNOPTIC LIFTING MECHANISMS SUBSIDE OVER THE NORTHERN HALF OF THE
PENINSULA DURING THE SECOND HALF OF THE NIGHT AS THE SHORTWAVE TO
OUR NORTH PASSES ON. WILL KEEP A CHANCE POP IN TO THE NORTH OF THE
I-4 CORRIDOR DUE TO WEAK RESIDUAL UPGLIDE AND SPEED DIVERGENCE...
HOWEVER...THE SHOWER ORGANIZATION AND SPATIAL COVERAGE IS LIKELY TO
BE LESS THAN EARLIER. LOW TEMPS LOOK COOL...BUT NOT UNSEASONABLE FOR
EARLY FEBRUARY...WITH MOST LOCATIONS DROPPING INTO THE LOWER/MIDDLE
50S. JUST A BIT WARMER IN THE UPPER 50S TO LOWER 60S CLOSE TO THE
COAST TO THE SOUTH OF MELBOURNE. HAVE A GREAT DAY!
.PREVIOUS DISCUSSION...
FRIDAY...THE STALLED FRONTAL BOUNDARY REMAINS OVER CENTRAL FL TO
LAKE OKEECHOBEE WITH PSBL DEVELOPMENT OF A WAVE ALONG THE BOUNDARY
EAST OF THE STATE BY EVENING. ONGOING FORECAST WITH SCT LIGHT TO
MODERATE RAIN WITH SOME SFC CONVERGENCE AND ISENTROPIC LIFTING ALONG
THE BOUNDARY PREDICTED FOR THE BULK OF THE FORECAST AREA.
CONSIDERABLE CLOUDS WITH RAIN AMOUNTS AROUND A TENTH OF AN INCH WITH
SOME LOCALLY HIGHER AMOUNTS.
WEEKEND...HAD TO KEEP A MENTIONABLE RAIN CHC SAT AND INTO SUN IN
THE FORECAST DUE TO PRESENCE OF BOUNDARY FROM MID AND LATE WEEK
REMAINING IN THE AREA. LOW PRESSURE ADVERTISED TO DEVELOP ALONG
WAVE NE OF STATE LATE SAT WITH VARYING PLACEMENT WL PRODUCE A SCT
RAIN CHC AS FEATURE AND ASCD REINFORCING COLD FRONT DRAG NEAR
AREA. DRYING AND COOLER CONDS SUN AS POST FRONTAL HIGH PRESSURE
WORKS INTO THE SOUTHEAST AND FL PENINSULA.
EXTENDED...CONTINUED DRY EARLY NEXT WEEK WITH CONTINENTAL WINDS
MON BECOMING ONSHORE BY EARLY TUE AND PERSISTING INTO MIDWEEK.
&&
.AVIATION...
SHALLOW OVERRUNNING EVENT BEHIND SFC COLD FRONT ACROSS DEEP S FL IS
PROVIDING MVFR CIGS ACROSS MOST SITES WITH IFR CIGS IN SOME SRN
SITES (VRB) ALONG WITH WEAK SHRA ALONG AND NORTH OF I4. CURRENT
GUIDANCE IS A BIT OVERDONE...INDICATING IFR CONDITIONS SHOULD BE
OCCURRING IN ALL AREAS. WILL KEEP A BIT MORE OPTIMISTIC FORECAST
WITH ALL AREAS BECOMING MVFR AND REMAINING THERE...BUT WILL
RE-EVALUATE LOWER CIG POTENTIAL FOR LATER IN THE DAY AND OVERNIGHT
WITH 18Z TAFS. SCT SHRA WILL REMAIN THROUGH THE PERIOD...ESP ACROSS
SITES FROM MLB TO ISM AND NORTHWARD.
&&
.MARINE...
TODAY AND TONIGHT...CAUTIONARY HEADLINES OVER NORTHERN TWO OFFSHORE
LEGS WILL BE EXPANDED TO INCLUDE ALL OFFSHORE AND NORTHERN NEAR
SHORE LEGS WITH EARLY MORNING PACKAGE AS FRONTAL SURGE WORKS IN FROM
THE NORTH. SOUTHERN OFFSHORE LEG CAUTION WILL BE MORE DUE TO
ANTICIPATED 6 FT SEAS BUILDING DOWN THE WATERS INTO THIS AFTERNOON.
AT THIS POINT APPEARS SOUTHERN NEAR SHORE LEG WILL REMAIN A LITTLE
BELOW CAUTION CRITERIA GIVEN THE DECREASE IN FORWARD MOTION OF THE
FRONT AS IT WORKS DOWN THE WATERS BUT WILL NEED TO BE MONITORED THIS
MORNING. AFTER INITIAL SURGE THIS MORNING WINDS WILL MAINTAIN A
NORTHERLY COMPONENT INTO TONIGHT BUT SPEEDS BACK OFF INTO 10-15KT
RANGE.
END OF WEEK...THE FRONTAL BOUNDARY REMAINS RELATIVELY CLOSE TO
THE LOCAL WATERS INTO SATURDAY. LOW PRESSURE DEVELOPMENT WL CREATE
SOME UNSETTLED CONDITIONS SAT. SEAS 5 TO 6 FT OVER THE OUTER
WATERS BY SAT MAY REQUIRE HEADLINES. NW COUNTERING WINDS WL KEEP
HIGHER SEAS AND WIND WAVES SUN.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 64 54 69 62 / 70 50 50 40
MCO 71 53 72 61 / 60 40 40 40
MLB 73 59 75 66 / 40 40 40 30
VRB 75 60 77 63 / 40 30 30 20
LEE 66 51 68 59 / 70 40 40 40
SFB 68 53 70 61 / 60 40 40 40
ORL 70 54 70 61 / 60 40 40 40
FPR 76 62 78 63 / 40 30 20 20
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
UPDATE...MROCZKA
AVIATION...COLSON/GITTINGER
PREVIOUS DISCUSSION...GLITTO/PENDERGRAST
AREA FORECAST DISCUSSION
NWS MIAMI FL
920 AM EST THU FEB 6 2014
.UPDATE...
A STALLED FRONTAL BOUNDARY WAS LOCATED FROM NEAR FORT MYERS
NORTHEASTWARD THROUGH VERO BEACH THIS MORNING. DENSE FOG FORMED
SOUTH OF THIS BOUNDARY...WITH VISIBILITIES 1/4 MILE OR LESS ACROSS
MUCH OF THE WESTERN INTERIOR. THE FOG IS BEGINNING TO LIFT AND THE
DENSE FOG ADVISORY WAS ALLOWED TO EXPIRE FOR THE LAND AND WATER
AREAS AT 9 AM. DENSE FOG DEVELOPED OVER THE LOCAL GULF WATERS
WEST OF NAPLES LAST NIGHT. BEACH CAMS SHOW SOME FOG STILL
REMAINS...SO WILL KEEP PATCHY FOG IN THE FORECAST FOR THE GULF
WATERS THROUGHOUT THE DAY. DENSE FOG COULD REDEVELOP OVER THE
WATER THIS EVENING.
THE SURFACE BOUNDARY IS FORECAST TO REMAIN NEARLY STATIONARY
TODAY...AND SHOWERS AND A FEW THUNDERSTORMS ARE FORECAST TO
DEVELOP ALONG AND SOUTH OF THIS BOUNDARY. THE BEST CHANCE OF
SHOWERS AND STORMS IS ACROSS THE INTERIOR THIS AFTERNOON...WITH
SOME SHOWERS POSSIBLY MOVING INTO THE METRO AREAS OF PALM BEACH
AND BROWARD COUNTIES AS WELL. THE GLOBAL MODELS AS WELL AS THE
LOCAL WRF MODELS AND HRRR ARE ALL IN GOOD AGREEMENT ON THIS
SCENARIO THIS AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 628 AM EST THU FEB 6 2014/
AVIATION...
KAPF WILL SLOWLY COME OUT OF THE IFR CONDITIONS BY 14Z THIS
MORNING DUE TO THE FOG BURNING OFF. REST OF THE TAF SITES WILL BE
IN THE VFR CONDITIONS TODAY. SHOWERS/TSTORMS LOOK TO FOCUS OVER
THE INTERIOR THIS AFTERNOON. KPBI STANDS THE BETTER CHANCE OF A
FEW SHRA/TSRA MOVING IN FROM THE WEST LATE THIS AFTERNOON SO
INCLUDED VCTS THERE. BNB
PREV DISCUSSION... /ISSUED 310 AM EST THU FEB 6 2014/
.ABOVE NORMAL TEMPERATURES CONTINUE THROUGH THE WEEKEND OVER SOUTH FLORIDA...
.PATCHY TO AREAS OF FOG EACH NIGHT THROUGH THE WEEKEND...
SHORT TERM...
FOG HAS DEVELOPED EARLY THIS MORNING OVER THE WESTERN AREAS OF
SOUTH FLORIDA WITH ISOLATED AREAS OF DENSE FOG. THE FOG SHOULD
CONTINUE OVER THE WESTERN AREAS THROUGH SUNRISE WHILE SPREADING
INTO THE EASTERN INTERIOR AREAS OF SOUTH FLORIDA. SO A DENSE FOG
ADVISORY HAS BEEN ISSUED FOR THE WESTERN AREAS OF SOUTH FLORIDA
THROUGH 9 AM EDT THIS MORNING...AND WE WILL CONTINUE TO MONITOR
THE EASTERN INTERIOR AREAS OF SOUTH FLORIDA THROUGH THE EARLY
MORNING HOURS TO SEE IF THE DENSE FOG ADVISORY NEEDS TO BE
EXPANDED EASTWARD.
A COLD FRONT OVER CENTRAL FLORIDA WILL CONTINUE TO MOVE SLOWLY
SOUTH TODAY...BEFORE STALLING OVER THE LAKE OKEECHOBEE REGION
TONIGHT. THIS WILL KEEP THE WIND FLOW OVER SOUTH FLORIDA IN A
SOUTHERLY DIRECTION TODAY ALONG WITH THE EAST AND WEST COAST SEA
BREEZES DEVELOPING AND PUSHING INLAND. SO THE BEST COVERAGE OF
SHOWERS WILL BE OVER THE INTERIOR AREAS TODAY ALONG WITH A FEW
STORMS LATE THIS AFTERNOON. THERE COULD ALSO BE A FEW STORMS OVER
METRO PALM BEACH COUNTY LATE THIS AFTERNOON INTO EARLY THIS
EVENING...AS THE STEERING FLOW WILL BECOME MORE SOUTHWEST AHEAD OF
THE FRONT.
FOG IS AGAIN POSSIBLE TONIGHT OVER MOST OF SOUTH FLORIDA WITH EVEN
SOME DENSE FOG POSSIBLE OVER THE INTERIOR AND WEST COAST METRO
AREAS...DUE TO THE FRONT NEARBY AND THE LIGHT SOUTH TO SOUTHWEST
STEERING FLOW. SO HAVE PUT IN FOG WORDING OVER MOST OF SOUTH FLORIDA
FOR LATE TONIGHT INTO EARLY FRIDAY MORNING WITH EVEN ISOLATED DENSE
FOG OVER THE INTERIOR AND WEST COAST METRO AREAS.
THE STATIONARY FRONT OVER LAKE OKEECHOBEE REGION WILL MOVE BACK
NORTHWARD INTO NORTHERN FLORIDA ON FRIDAY...AS A WEAK LOW
PRESSURE DEVELOPS OVER THE NORTHERN GULF OF MEXICO. THIS WILL
ALLOW FOR THE STEERING FLOW TO BE SOUTHEAST OVER SOUTH FLORIDA ON
FRIDAY BRINGING IN SOME DRIER AIR TO THE AREA FROM THE BAHAMA
ISLANDS. SO THE ONLY AREA THAT WILL SEE A SLIGHT CHANCE OF SHOWERS
WILL BE OVER THE INTERIOR AND WEST COAST METRO AREAS ON FRIDAY.
THE WEAK LOW WILL MOVE NORTHEAST ACROSS NORTHERN FLORIDA ON
SATURDAY BEFORE MOVING INTO THE WESTERN ATLANTIC WATERS ON SUNDAY.
THIS WILL ALLOW FOR THE WARM FRONT TO BECOME A COLD FRONT AND MOVE
SOUTH THROUGH SOUTH FLORIDA ON SUNDAY. SO THE SLIGHT CHANCE OF
SHOWERS WILL CONTINUE OVER SOUTH FLORIDA THIS WEEKEND...EXCEPT FOR
A CHANCE OF SHOWERS AROUND THE LAKE OKEECHOBEE REGION ON SATURDAY.
HIGHS THROUGH THIS WEEKEND WILL BE IN THE LOWER TO MID 80S WITH
LOWS IN THE 60S...EXCEPT AROUND 70 ALONG THE EAST COAST METRO
AREAS. THESE HIGHS AND LOWS ARE ABOUT 5 TO 10 DEGREES ABOVE THE
AVERAGE FOR THIS TIME OF YEAR. THE HEAT INDEX WILL ALSO BE RUNNING
IN THE MID 80S TO AROUND 90 DEGREES THIS WEEKEND.
LONG TERM...
DRY AND MORE COMFORTABLE WEATHER WILL RETURN TO SOUTH FLORIDA EARLY
NEXT WEEK BEHIND THE PASSAGE OF THE COLD FRONT LATE THIS WEEKEND.
HOWEVER...THE DRY AND COMFORTABLE WEATHER WILL NOT LAST LONG AS
ANOTHER LOW PRESSURE WILL DEVELOP OVER THE NORTHWEST GULF OF
MEXICO AND MOVE NORTHEAST ACROSS THE SOUTHEASTERN UNITED STATES BY
MIDDLE OF NEXT WEEK. THIS IN TURN WILL BRING THE WINDS BACK TO A
SOUTHERLY DIRECTION AND BRING IN THE MOISTURE FROM THE SOUTH BY THE
MIDDLE OF NEXT WEEK. THERE WILL ALSO BE A 20 TO 30 PERCENT CHANCE OF
SHOWERS OVER THE AREA MIDDLE OF NEXT WEEK.
AVIATION...
KAPF JUST WENT DOWN TO 1/4SM FG AND LOOKS AS THOUGH
THIS MAY HANG IN ALL NIGHT SO KEPT THIS CONDITION GOING. ELSEWHERE
THE THINKING IS THAT LOW CLOUDINESS WILL DEVELOP IN MVFR CATEGORY.
WILL HAVE TO KEEP AN EYE OUT FOR POSSIBLE IFR AS WELL, BUT GIVEN
UNCERTAINTIES MAINTAINED MVFR EAST COAST SITES. POSSIBLE
IMPROVEMENT DURING THE DAY, BUT MVFR COULD HANG ON THROUGHOUT THE
DAY...ESPECIALLY AT KAPF. SHOWERS/TSTORMS LOOK TO FOCUS OVER THE
INTERIOR THIS AFTERNOON. KPBI STANDS THE BETTER CHANCE OF A FEW
SHRA/TSRA MOVING IN FROM THE WEST LATE THIS AFTERNOON SO INCLUDED
VCTS THERE. /GREGORIA
MARINE...
THE WINDS WILL REMAIN BELOW 10 KNOTS TODAY INTO THIS WEEKEND WHILE
SLOWLY REMAINING IN A SOUTHERLY DIRECTION. THIS WILL KEEP THE SEAS
BELOW 6 FEET TODAY INTO THIS WEEKEND IN BOTH THE ATLANTIC AND GULF
WATERS. SO BOATING CONDITIONS SHOULD BE GOOD THIS WEEKEND OUTSIDE
OF ANY SHOWERS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 81 67 82 68 / 30 30 10 10
FORT LAUDERDALE 82 70 83 72 / 20 20 10 10
MIAMI 83 71 84 71 / 20 20 10 10
NAPLES 81 63 82 64 / 20 20 20 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...84/AK
AVIATION/RADAR...85/AG
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
638 AM EST THU FEB 6 2014
.SYNOPSIS...
HIGH PRESSURE WILL BE CENTERED NORTH AND WEST OF THE FORECAST
AREA THROUGH FRIDAY. AN UPPER-LEVEL DISTURBANCE WILL BRING
ENHANCED CLOUDINESS TONIGHT. LOW PRESSURE WILL DEVELOP OFF THE
SOUTHEAST COAST SATURDAY AND SHOULD HAVE LIFTED WELL NORTHEAST OF
THE AREA BY SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
TODAY...THE LOWER LEVELS OF THE ATMOSPHERE WILL REMAIN DRY
TODAY. THE SURFACE HIGH CENTERED WELL TO OUR WEST WILL DIRECT A
DRY NORTHERLY FLOW INTO OUR AREA. HOWEVER...THERE WILL BE MID AND
HIGH CLOUDINESS IN THE WEST-SOUTHWEST FLOW ASSOCIATED WITH THE
BROAD TROUGH. LIFT AHEAD OF A MID-LEVEL SHORTWAVE TROUGH COULD
HELP SUPPORT LIGHT RAIN TOWARD THE END OF THE DAY IN THE SOUTH
PART. THE 08Z HRRR INDICATED SPOTTY AREAS OF RAIN IN THE CENTRAL
SAVANNAH RIVER AREA BEGINNING AROUND 22Z. THE TEMPERATURE
GUIDANCE WAS CLOSE WITH HIGHS NEAR 50 NORTH TO THE MIDDLE 50S
SOUTHEAST.
TONIGHT...THE MODELS INDICATE LIFT ASSOCIATED WITH A SHORTWAVE
TROUGH MAINLY EARLY TONIGHT. MOISTURE WILL BE LIMITED WITH H85
WESTERLY FLOW AND NEUTRAL THERMAL ADVECTION. THE PRECIPITATION
CHANCE APPEARS LOW. KEPT SLIGHT CHANCE POPS MAINLY IN THE SOUTH
PART WHICH SHOULD BE CLOSER TO A LITTLE DEEPER MOISTURE. THE NAM
AND GFS ARE CONSISTENT KEEPING SURFACE TEMPERATURES ABOVE FREEZING
DURING THIS TIME. DRYING AND COLD ADVECTION BEHIND THE SHORTWAVE
TROUGH SUPPORTS TEMPERATURES FALLING BELOW FREEZING TOWARD
SUNRISE. THE TEMPERATURE GUIDANCE WAS CLOSE WITH LOWS IN THE UPPER
20S AND LOWER 30S.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
THE NAM AND GFS ARE CONSISTENT SHOWING A DRY AIR MASS REMAINING IN
PLACE FRIDAY AND FRIDAY EVENING. MOISTURE WILL BE ON THE INCREASE
LATE FRIDAY NIGHT ASSOCIATED WITH LOW PRESSURE DEVELOPING OFF THE
SOUTHEAST COAST. THE NAM AND GFS SHOW THIS FEATURE LIFTING
NORTHEAST OF THE FORECAST AREA SATURDAY AND SATURDAY NIGHT. THE
MODELS SHOW DEEPER MOISTURE AND ISENTROPIC LIFT CONFINED TO THE
EASTERN PART OF THE FORECAST AREA SATURDAY MORNING. WE FORECASTED
LIKELY POPS IN THE EAST PART WITH JUST CHANCE ELSEWHERE DURING
THAT TIME. MODEL TIME-HEIGHT DISPLAYS SUPPORT LIQUID PRECIPITATION.
EXPECT DRYING BEHIND THE SYSTEM FOR SATURDAY AFTERNOON AND NIGHT.
USED THE GUIDANCE CONSENSUS FOR THE TEMPERATURE FORECAST.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
THE GFS AND ECMWF DISPLAY A DRY PATTERN SUNDAY THROUGH MONDAY WITH H85
WESTERLY FLOW AND COLD OR NEUTRAL THERMAL ADVECTION DOMINATING.
THE MODELS SHOW A WEDGE-RIDGE PATTERN TUESDAY AND WEDNESDAY WITH A
DEVELOPING SIGNIFICANT UPPER-LEVEL TROUGH AND ASSOCIATED LOW
PRESSURE SYSTEM. THE MODELS HAVE NOT BEEN CONSISTENT WITH THE
TIMING OF THIS SYSTEM BUT THE 00Z GFS AND ECMWF DO INDICATE DEEP
MOISTURE WEDNESDAY WITH LOW PRESSURE NEARING THE FORECAST AREA.
THERE IS A POSSIBILITY OF ENOUGH COLD AIR ASSOCIATED WITH THE
WEDGE PATTERN FOR WINTER-TYPE PRECIPITATION MAINLY IN THE NORTH
PART.
&&
.AVIATION /11Z THURSDAY THROUGH MONDAY/...
VFR CONDITIONS EXPECTED THROUGH THE TAF FORECAST PERIOD.
HIGH PRESSURE WILL REMAIN OVER THE AREA TODAY WITH RIPPLES OF ENERGY
IN SOUTHWEST FLOW ALOFT CAUSING BKN/OVC MIDDLE AND HIGH-LEVEL CLOUDS
FOR MUCH OF THE TAF PERIOD. WINDS WILL GRADUALLY SHIFT TO
NORTHEASTERLY MAINLY AFTER 13Z THIS MORNING. A FEW SPRINKLES MAY BE
POSSIBLE LATE THIS AFTERNOON INTO THE EVENING HOURS MAINLY AT
AGS/DNL/OGB...BUT NOT ENOUGH CONFIDENCE TO MENTION IN THE TAFS AT
THIS TIME. CIGS WILL REMAIN VFR TODAY INTO TONIGHT BUT MAY BECOME
MORE SCT/BKN TOWARDS THE END OF THE PERIOD.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE FRIDAY NIGHT INTO
SATURDAY AS ANOTHER SYSTEM.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1001 AM CST THU FEB 6 2014
.DISCUSSION...
952 AM CST
WE WILL BE LETTING THE WIND CHILL ADVISORY FOR THIS MORNING EXPIRE
AT 10 AM. SEVERAL SITES OUT WEST ARE STILL HOVERING RIGHT AROUND
-20 FOR THE WIND CHILL...BUT THESE AREAS SHOULD IMPROVE SOME INTO
NEXT HOUR OR TWO...AND WE FELT THAT IT WAS NOT WORTH EXTENDING THE
ADVISORY FOR ANOTHER HOUR OR TWO. OTHERWISE...NO MAJOR CHANGES TO
THE GOING FORECAST. WE WILL ASSES THE NEED TO EXPAND THE WIND
CHILL ADVISORY FOR TONIGHT INTO FRIDAY ACROSS THE REST OF THE AREA
WITH THE AFTERNOON PACKAGE.
KJB
//PREV DISCUSSION...
333 AM CST
THIS FORECAST WAS FOCUSED ON CURRENT COLD AIR THROUGH FRIDAY AS
WELL AS THE NEXT ROUND EARLY NEXT WEEK...WITH A SNOW EVENT
SANDWICHED IN-BETWEEN ON SATURDAY. THERE SURE HAVE BEEN PLENTY OF
THESE COLD-SNOW-COLD SANDWICHES THIS WINTER!
TODAY...
FROM A MASSIVE STORM SYSTEM YESTERDAY MORNING TO A MASSIVE HIGH
PRESSURE THIS MORNING...THE PROGRESSIVE FLOW CONTINUES. THIS
MORNINGS HIGH CENTERED AT 1043MB FROM MT INTO THE CENTRAL PLAINS
IS TRYING TO NUDGE ITS WAY INTO THE AREA. AT THE LEADING EDGE OF
THE 850-925MB THERMAL TROUGH THERE HAVE BEEN UNDULATING POCKETS OF
STRATOCU WITH FLURRIES EARLY THIS MORNING OVER THE FORECAST AREA.
THE RAP ANALYZES THIS WELL AND PROPAGATES THIS CAA/RH EAST OF
THE AREA BY MID-MORNING. COULD BE SOME FEW-SCT FINGERS OF CU TO
REDEVELOP TODAY AS COLD AIR ADVECTION AT THE TOP OF THE MIXED LAYER
CONTINUES THROUGH EARLY AFTERNOON. THIS ALSO COULD BE REALIZED AT
THE SFC WITH TEMPS STEADY OR EVEN SLOWLY DROPPING THROUGH 9-10 AM
IN SOME COMMUNITIES. THE REBOUND WILL BE SMALL TODAY WITH HIGHS
IN THE 5 TO THE 10 ABOVE RANGE...WITH MAYBE 12-14 IN DOWNTOWN
CHICAGO. THOSE ARE A COUPLE-FEW DEGREES HIGHER THAN INHERITED AND
THIS CLIMB WAS BECAUSE THESE EARLY MORNING CLOUDS THAT HAVE KEPT
SOME READINGS UP.
TONIGHT/FRIDAY...
THE HIGH PRESSURE WILL EXPAND EAST INTO THE MID-MISSISSIPPI
VALLEY BY LATE THIS EVE AND WEAKEN SLOWLY AS IT DOES. WE SHOULD
MAINTAIN SOME WIND COMPONENT...ALTHOUGH SUSPECT THAT GUIDANCE MAY
BE TOO HIGH ON WIND SPEEDS AS THEY OFTEN CAN BE AT NIGHT AND OVER
SNOW COVER. EVEN WITH 5-8 KT WINDS...WIND CHILL ADVISORY CRITERIA
LOOKS TO BE REACHED IN A GOOD PART OF THE AREA THAT IS UNDER THE
CURRENT WIND CHILL ADVISORY. AS FOR ACROSS THE SOUTHERN FORECAST
AREA...WHICH IS CLOSEST TO THE ACTIVE JET ACROSS THE SOUTHERN
U.S...THERE WILL LIKELY BE AT LEAST SOME THIN CIRRUS...IF NOT
BROKEN. SO A BIT MORE MARGINAL THERE. HAVE GONE WITH A WIND CHILL
ADVISORY FOR TONIGHT/FRIDAY IN THE CURRENT ADVISORY AREA TO GET
THE MESSAGE OUT. WILL LET DAY SHIFT ASSESS IF IT NEEDS TO BE
EXPANDED EAST...INCLUDING INTO THE CHICAGO METRO AREA. SOUTHWEST
FLOW GRADUALLY STARTS TO ENVELOP THE AREA FRIDAY BEHIND THE
HIGH...SO A HANDFUL OF DEGREES ARE EXPECTED TO BE ADDED TO TODAYS
HIGHS...WITH 10 TO 15 FORECAST ON FRIDAY.
SATURDAY/SATURDAY NIGHT...
GOOD AGREEMENT IN GUIDANCE ON MASS FIELDS REMAINS THE CASE THROUGH
THE FIRST HALF OF THE WEEKEND...WITH A STRONG WESTERLY UPPER JET
MOVING OVER THE WEST COAST AND ADVANCING EAST INTO THE CENTRAL
PLAINS. A QUICK-MOVING SORT OF HYBRID PACIFIC/CLIPPER SYSTEM IS
EXPECTED TO PROGRESS WITH THE LEFT EXIT REGION OF THIS INTO THE
AREA. DIFFERENCES DO EXIST IN GUIDANCE IN HOW IT EVOLVES THE LOW-
LEVEL FEATURES...WITH THE 00Z/06Z NAM BEING 10MB DEEPER THAN THE
00Z EC ON THE SURFACE WAVE...AND ACTUALLY THE ONLY MODEL SHOWING A
DEEPENING TREND IN THE SFC WAVE AS IT MOVES EAST OVER THE FORECAST
AREA. WHILE THE NAM CAN BE A BIT ROBUST ON DAY 3 IT SEEMS...THE
PV ANOMALY ASSOCIATED WITH THE UPPER TROUGH IS QUITE STRONG AND
ITS ORIENTATION WOULD FAVOR A LOW TO AT LEAST HOLD ITS INTENSITY
AS IT MOVES OVER THE AREA. SO AGAIN LEAN WITH THE MIDDLE GROUND
00Z GFS...WHICH ALSO HAS A MIDDLE GROUND QPF FORECAST.
THE IMPRESSIVE FEATURE WITH THIS IS THE MID-LEVEL VORT MAGNITUDE
AND ITS ADVECTION...DIRECTLY OVER AT LEAST PART OF THE FORECAST AREA
ON GUIDANCE...AND IT TIGHTENS THE BAROCLINIC ZONE TO WHERE IT
WOULD SEEM TEMPORARY BANDING COULD BE A CONCERN. THE GFS ALSO WOULD
SUGGEST THE DENDRITIC GROWTH ZONE IS LIKELY TO BE TAPPED AND GIVEN
A LIMITED RETURN FLOW PERIOD...WOULD EXPECT THE COLUMN TO BE COOL
ENOUGH TO PRESENT THIS AS A POSSIBLE CONCERN. SO HAVE GONE TOWARD
15:1 RATIOS IN INITIAL SNOW FORECAST. VORT MAGNITUDE USING
EMPIRICAL LEMO TECHNIQUE WOULD SUPPORT AT LEAST A FEW INCH STRIPE
OF SNOW SOMEWHERE...BUT WE WILL HAVE TO SEE AS WE GET CLOSER...AS
DURATION OF SNOW COULD OVERALL BE LIMITED IF EARLY SATURATION IS
AN ISSUE. WHILE CONTINUED THE TREND TO INCH UP POPS...NOW WITH 70
PERCENTS ACROSS MUCH OF NORTHERN IL ON SATURDAY. DID NOT GET FANCY
TRYING TO BREAK OUT MORNING VS AFTERNOON...BUT SOME TEMPORAL
RESOLUTION WILL INEVITABLY BE ABLE TO BE ADDED IN TIME.
SUNDAY AND BEYOND...
NORTHWEST FLOW ALOFT REMAINS FORECAST DURING EARLY NEXT
WEEK...WITH COLD AIR ADVECTION DEVELOPING BEHIND THE SATURDAY
SYSTEM. SUNDAY NIGHT/MONDAY MORNING COULD VERY WELL BE A PERIOD OF
WIND CHILL CONCERNS AGAIN. THE 925MB TEMPERATURES IN THE -15C TO
-20C RANGE ONCE AGAIN COULD SUPPORT NEGATIVE DOUBLE DIGIT LOWS IN
MOST OUTLYING AREAS ON MONDAY NIGHT WHERE LONG RANGE GUIDANCE
INDICATES HIGH PRESSURE AND A CLEAR SKY OVER THE FRESHENED SNOW
PACK. HAVE LEANED TOWARD A RAW BLEND OF GUIDANCE /NO MOS/ IN THAT
PERIOD...AND EVEN UNDERCUT THAT BY A FEW DEGREES. WITH THE HIGH
PRESSURE AND DEGREE OF SUBSIDENCE MOVING OVERHEAD IT LOOKS LIKE A
POSSIBLE MINI-PERIOD OF DRY WEATHER /OUTSIDE OF FLURRIES/ DURING
SUN THROUGH TUE...AT LEAST AT THIS TIME.
MTF
&&
.CLIMATE...
RECORD COLD HIGHS FOR TODAY FEBRUARY 6TH:
ROCKFORD: 3 DEGREES (1982)
WHILE THIS IS NOT LIKELY TO BE BROKEN TODAY...THE TEMPERATURE AT
MIDNIGHT WAS 2 DEGREES AND IT COULD BE CLOSE THIS AFTERNOON.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* NONE.
KREIN
//DISCUSSION...UPDATED 12Z...
A FAIRLY QUIET WEATHER DAY ON TAP WITH VFR CONDITIONS AND WEST FLOW
PREVAILING. SOME LINGERING FLURRIES AND MVFR CIGS PERSIST OVER
PORTIONS OF THE CHICAGO METRO THIS MORNING BUT ARE PROGGED TO MOVE
OUT EARLY THIS MORNING. RAP 900-925 RH HAS HAD A DECENT HANDLE ON
THE PROGRESSION THIS MORNING AND INDICATES CLEARING SHORTLY. THERE
MAY BE SOME COLD AIR CU THAT REDEVELOPS TODAY BETWEEN 020-025...BUT
ANTICIPATE IT BEING FEW TO SCT IN COVERAGE IF IT EVEN DEVELOPS.
GUSTS WILL ALSO PICK UP LATER IN THE MORNING THROUGH THE
AFTERNOON...INTO THE MID POSSIBLY UPPER TEENS. WINDS WILL TAPER
AGAIN IN THE EVENING AROUND SUNSET.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH CONFIDENCE IN ALL FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...VFR.
SATURDAY...SNOW LIKELY WITH SOME ACCUMULATION. IFR PSBL.
SUNDAY THROUGH WEDNESDAY...VFR LIKELY.
BMD
&&
.MARINE...
258 AM CST
AN EXPANSIVE AREA OF HIGH PRESSURE SPANS FROM THE CANADIAN ROCKIES
ACROSS THE CENTRAL PLAINS WITH A RIDGE EXTENDING EAST ALONG THE OHIO
RIVER VALLEY. WITH LOW PRESSURE SPINNING OVER HUDSON BAY...THIS WILL
LEAVE LAKE MICHIGAN IN A PERIOD OF MODERATE WESTERLY FLOW STARTING
LATER TODAY AS WINDS RAMP BACK UP TO AROUND 30 KT. WITH TEMPS
FALLING INTO THE SINGLE DIGITS ACROSS MAINLY THE NORTH HALF OF THE
LAKE...CONDITIONS ARE FAVORABLE FOR FREEZING SPRAY TO DEVELOP. THE
THREAT WILL DIMINISH FRIDAY NIGHT AS THE WINDS BEGIN TO SUBSIDE. LOW
PRESSURE WILL MOVE ACROSS THE SOUTHERN LAKE REGION OVER THE
WEEKEND...WITH ANOTHER COLD CANADIAN HIGH BUILDING BACK INTO THE
MIDWEST AND GREAT LAKES EARLY NEXT WEEK WITH LIGHT FLOW EXPECTED.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WIND CHILL ADVISORY...ILZ003-ILZ004-ILZ005-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ019-ILZ020-ILZ021-ILZ032 UNTIL 10 AM THURSDAY.
WIND CHILL ADVISORY...ILZ003-ILZ004-ILZ005-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ019-ILZ020-ILZ021-ILZ032...9 PM THURSDAY TO 11 AM
FRIDAY.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
956 AM CST THU FEB 6 2014
.DISCUSSION...
952 AM CST
WE WILL BE LETTING THE WIND CHILL ADVISORY FOR THIS MORNING EXPIRE
AT 10 AM. SEVERAL SITES OUT WEST ARE STILL HOVERING RIGHT AROUND
-20 FOR THE WIND CHILL...BUT THESE AREAS SHOULD IMPROVE SOME INTO
NEXT HOUR OR TWO...AND WE FELT THAT IT WAS NOT WORTH EXTENDING THE
ADVISORY FOR ANOTHER HOUR OR TWO. OTHERWISE...NO MAJOR CHANGES TO
THE GOING FORECAST. WE WILL ASSES THE NEED TO EXPAND THE WIND
CHILL ADVISORY FOR TONIGHT INTO FRIDAY ACROSS THE REST OF THE AREA
WITH THE AFTERNOON PACKAGE.
KJB
&&
.PREV DISCUSSION...
333 AM CST
THIS FORECAST WAS FOCUSED ON CURRENT COLD AIR THROUGH FRIDAY AS
WELL AS THE NEXT ROUND EARLY NEXT WEEK...WITH A SNOW EVENT
SANDWICHED IN-BETWEEN ON SATURDAY. THERE SURE HAVE BEEN PLENTY OF
THESE COLD-SNOW-COLD SANDWICHES THIS WINTER!
TODAY...
FROM A MASSIVE STORM SYSTEM YESTERDAY MORNING TO A MASSIVE HIGH
PRESSURE THIS MORNING...THE PROGRESSIVE FLOW CONTINUES. THIS
MORNINGS HIGH CENTERED AT 1043MB FROM MT INTO THE CENTRAL PLAINS
IS TRYING TO NUDGE ITS WAY INTO THE AREA. AT THE LEADING EDGE OF
THE 850-925MB THERMAL TROUGH THERE HAVE BEEN UNDULATING POCKETS OF
STRATOCU WITH FLURRIES EARLY THIS MORNING OVER THE FORECAST AREA.
THE RAP ANALYZES THIS WELL AND PROPAGATES THIS CAA/RH EAST OF
THE AREA BY MID-MORNING. COULD BE SOME FEW-SCT FINGERS OF CU TO
REDEVELOP TODAY AS COLD AIR ADVECTION AT THE TOP OF THE MIXED LAYER
CONTINUES THROUGH EARLY AFTERNOON. THIS ALSO COULD BE REALIZED AT
THE SFC WITH TEMPS STEADY OR EVEN SLOWLY DROPPING THROUGH 9-10 AM
IN SOME COMMUNITIES. THE REBOUND WILL BE SMALL TODAY WITH HIGHS
IN THE 5 TO THE 10 ABOVE RANGE...WITH MAYBE 12-14 IN DOWNTOWN
CHICAGO. THOSE ARE A COUPLE-FEW DEGREES HIGHER THAN INHERITED AND
THIS CLIMB WAS BECAUSE THESE EARLY MORNING CLOUDS THAT HAVE KEPT
SOME READINGS UP.
TONIGHT/FRIDAY...
THE HIGH PRESSURE WILL EXPAND EAST INTO THE MID-MISSISSIPPI
VALLEY BY LATE THIS EVE AND WEAKEN SLOWLY AS IT DOES. WE SHOULD
MAINTAIN SOME WIND COMPONENT...ALTHOUGH SUSPECT THAT GUIDANCE MAY
BE TOO HIGH ON WIND SPEEDS AS THEY OFTEN CAN BE AT NIGHT AND OVER
SNOW COVER. EVEN WITH 5-8 KT WINDS...WIND CHILL ADVISORY CRITERIA
LOOKS TO BE REACHED IN A GOOD PART OF THE AREA THAT IS UNDER THE
CURRENT WIND CHILL ADVISORY. AS FOR ACROSS THE SOUTHERN FORECAST
AREA...WHICH IS CLOSEST TO THE ACTIVE JET ACROSS THE SOUTHERN
U.S...THERE WILL LIKELY BE AT LEAST SOME THIN CIRRUS...IF NOT
BROKEN. SO A BIT MORE MARGINAL THERE. HAVE GONE WITH A WIND CHILL
ADVISORY FOR TONIGHT/FRIDAY IN THE CURRENT ADVISORY AREA TO GET
THE MESSAGE OUT. WILL LET DAY SHIFT ASSESS IF IT NEEDS TO BE
EXPANDED EAST...INCLUDING INTO THE CHICAGO METRO AREA. SOUTHWEST
FLOW GRADUALLY STARTS TO ENVELOP THE AREA FRIDAY BEHIND THE
HIGH...SO A HANDFUL OF DEGREES ARE EXPECTED TO BE ADDED TO TODAYS
HIGHS...WITH 10 TO 15 FORECAST ON FRIDAY.
SATURDAY/SATURDAY NIGHT...
GOOD AGREEMENT IN GUIDANCE ON MASS FIELDS REMAINS THE CASE THROUGH
THE FIRST HALF OF THE WEEKEND...WITH A STRONG WESTERLY UPPER JET
MOVING OVER THE WEST COAST AND ADVANCING EAST INTO THE CENTRAL
PLAINS. A QUICK-MOVING SORT OF HYBRID PACIFIC/CLIPPER SYSTEM IS
EXPECTED TO PROGRESS WITH THE LEFT EXIT REGION OF THIS INTO THE
AREA. DIFFERENCES DO EXIST IN GUIDANCE IN HOW IT EVOLVES THE LOW-
LEVEL FEATURES...WITH THE 00Z/06Z NAM BEING 10MB DEEPER THAN THE
00Z EC ON THE SURFACE WAVE...AND ACTUALLY THE ONLY MODEL SHOWING A
DEEPENING TREND IN THE SFC WAVE AS IT MOVES EAST OVER THE FORECAST
AREA. WHILE THE NAM CAN BE A BIT ROBUST ON DAY 3 IT SEEMS...THE
PV ANOMALY ASSOCIATED WITH THE UPPER TROUGH IS QUITE STRONG AND
ITS ORIENTATION WOULD FAVOR A LOW TO AT LEAST HOLD ITS INTENSITY
AS IT MOVES OVER THE AREA. SO AGAIN LEAN WITH THE MIDDLE GROUND
00Z GFS...WHICH ALSO HAS A MIDDLE GROUND QPF FORECAST.
THE IMPRESSIVE FEATURE WITH THIS IS THE MID-LEVEL VORT MAGNITUDE
AND ITS ADVECTION...DIRECTLY OVER AT LEAST PART OF THE FORECAST AREA
ON GUIDANCE...AND IT TIGHTENS THE BAROCLINIC ZONE TO WHERE IT
WOULD SEEM TEMPORARY BANDING COULD BE A CONCERN. THE GFS ALSO WOULD
SUGGEST THE DENDRITIC GROWTH ZONE IS LIKELY TO BE TAPPED AND GIVEN
A LIMITED RETURN FLOW PERIOD...WOULD EXPECT THE COLUMN TO BE COOL
ENOUGH TO PRESENT THIS AS A POSSIBLE CONCERN. SO HAVE GONE TOWARD
15:1 RATIOS IN INITIAL SNOW FORECAST. VORT MAGNITUDE USING
EMPIRICAL LEMO TECHNIQUE WOULD SUPPORT AT LEAST A FEW INCH STRIPE
OF SNOW SOMEWHERE...BUT WE WILL HAVE TO SEE AS WE GET CLOSER...AS
DURATION OF SNOW COULD OVERALL BE LIMITED IF EARLY SATURATION IS
AN ISSUE. WHILE CONTINUED THE TREND TO INCH UP POPS...NOW WITH 70
PERCENTS ACROSS MUCH OF NORTHERN IL ON SATURDAY. DID NOT GET FANCY
TRYING TO BREAK OUT MORNING VS AFTERNOON...BUT SOME TEMPORAL
RESOLUTION WILL INEVITABLY BE ABLE TO BE ADDED IN TIME.
SUNDAY AND BEYOND...
NORTHWEST FLOW ALOFT REMAINS FORECAST DURING EARLY NEXT
WEEK...WITH COLD AIR ADVECTION DEVELOPING BEHIND THE SATURDAY
SYSTEM. SUNDAY NIGHT/MONDAY MORNING COULD VERY WELL BE A PERIOD OF
WIND CHILL CONCERNS AGAIN. THE 925MB TEMPERATURES IN THE -15C TO
-20C RANGE ONCE AGAIN COULD SUPPORT NEGATIVE DOUBLE DIGIT LOWS IN
MOST OUTLYING AREAS ON MONDAY NIGHT WHERE LONG RANGE GUIDANCE
INDICATES HIGH PRESSURE AND A CLEAR SKY OVER THE FRESHENED SNOW
PACK. HAVE LEANED TOWARD A RAW BLEND OF GUIDANCE /NO MOS/ IN THAT
PERIOD...AND EVEN UNDERCUT THAT BY A FEW DEGREES. WITH THE HIGH
PRESSURE AND DEGREE OF SUBSIDENCE MOVING OVERHEAD IT LOOKS LIKE A
POSSIBLE MINI-PERIOD OF DRY WEATHER /OUTSIDE OF FLURRIES/ DURING
SUN THROUGH TUE...AT LEAST AT THIS TIME.
MTF
&&
.CLIMATE...
RECORD COLD HIGHS FOR TODAY FEBRUARY 6TH:
ROCKFORD: 3 DEGREES (1982)
WHILE THIS IS NOT LIKELY TO BE BROKEN TODAY...THE TEMPERATURE AT
MIDNIGHT WAS 2 DEGREES AND IT COULD BE CLOSE THIS AFTERNOON.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* NONE.
KREIN
//DISCUSSION...UPDATED 12Z...
A FAIRLY QUIET WEATHER DAY ON TAP WITH VFR CONDITIONS AND WEST FLOW
PREVAILING. SOME LINGERING FLURRIES AND MVFR CIGS PERSIST OVER
PORTIONS OF THE CHICAGO METRO THIS MORNING BUT ARE PROGGED TO MOVE
OUT EARLY THIS MORNING. RAP 900-925 RH HAS HAD A DECENT HANDLE ON
THE PROGRESSION THIS MORNING AND INDICATES CLEARING SHORTLY. THERE
MAY BE SOME COLD AIR CU THAT REDEVELOPS TODAY BETWEEN 020-025...BUT
ANTICIPATE IT BEING FEW TO SCT IN COVERAGE IF IT EVEN DEVELOPS.
GUSTS WILL ALSO PICK UP LATER IN THE MORNING THROUGH THE
AFTERNOON...INTO THE MID POSSIBLY UPPER TEENS. WINDS WILL TAPER
AGAIN IN THE EVENING AROUND SUNSET.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* HIGH CONFIDENCE IN ALL FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...VFR.
SATURDAY...SNOW LIKELY WITH SOME ACCUMULATION. IFR PSBL.
SUNDAY THROUGH WEDNESDAY...VFR LIKELY.
BMD
&&
.MARINE...
258 AM CST
AN EXPANSIVE AREA OF HIGH PRESSURE SPANS FROM THE CANADIAN ROCKIES
ACROSS THE CENTRAL PLAINS WITH A RIDGE EXTENDING EAST ALONG THE OHIO
RIVER VALLEY. WITH LOW PRESSURE SPINNING OVER HUDSON BAY...THIS WILL
LEAVE LAKE MICHIGAN IN A PERIOD OF MODERATE WESTERLY FLOW STARTING
LATER TODAY AS WINDS RAMP BACK UP TO AROUND 30 KT. WITH TEMPS
FALLING INTO THE SINGLE DIGITS ACROSS MAINLY THE NORTH HALF OF THE
LAKE...CONDITIONS ARE FAVORABLE FOR FREEZING SPRAY TO DEVELOP. THE
THREAT WILL DIMINISH FRIDAY NIGHT AS THE WINDS BEGIN TO SUBSIDE. LOW
PRESSURE WILL MOVE ACROSS THE SOUTHERN LAKE REGION OVER THE
WEEKEND...WITH ANOTHER COLD CANADIAN HIGH BUILDING BACK INTO THE
MIDWEST AND GREAT LAKES EARLY NEXT WEEK WITH LIGHT FLOW EXPECTED.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WIND CHILL ADVISORY...ILZ003-ILZ004-ILZ005-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ019-ILZ020-ILZ021-ILZ032...9 PM THURSDAY TO 11 AM
FRIDAY.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
754 AM CST THU FEB 6 2014
.DISCUSSION...
333 AM CST
THIS FORECAST WAS FOCUSED ON CURRENT COLD AIR THROUGH FRIDAY AS
WELL AS THE NEXT ROUND EARLY NEXT WEEK...WITH A SNOW EVENT
SANDWICHED IN-BETWEEN ON SATURDAY. THERE SURE HAVE BEEN PLENTY OF
THESE COLD-SNOW-COLD SANDWICHES THIS WINTER!
TODAY...
FROM A MASSIVE STORM SYSTEM YESTERDAY MORNING TO A MASSIVE HIGH
PRESSURE THIS MORNING...THE PROGRESSIVE FLOW CONTINUES. THIS
MORNINGS HIGH CENTERED AT 1043MB FROM MT INTO THE CENTRAL PLAINS
IS TRYING TO NUDGE ITS WAY INTO THE AREA. AT THE LEADING EDGE OF
THE 850-925MB THERMAL TROUGH THERE HAVE BEEN UNDULATING POCKETS OF
STRATOCU WITH FLURRIES EARLY THIS MORNING OVER THE FORECAST AREA.
THE RAP ANALYZES THIS WELL AND PROPAGATES THIS CAA/RH EAST OF
THE AREA BY MID-MORNING. COULD BE SOME FEW-SCT FINGERS OF CU TO
REDEVELOP TODAY AS COLD AIR ADVECTION AT THE TOP OF THE MIXED LAYER
CONTINUES THROUGH EARLY AFTERNOON. THIS ALSO COULD BE REALIZED AT
THE SFC WITH TEMPS STEADY OR EVEN SLOWLY DROPPING THROUGH 9-10 AM
IN SOME COMMUNITIES. THE REBOUND WILL BE SMALL TODAY WITH HIGHS
IN THE 5 TO THE 10 ABOVE RANGE...WITH MAYBE 12-14 IN DOWNTOWN
CHICAGO. THOSE ARE A COUPLE-FEW DEGREES HIGHER THAN INHERITED AND
THIS CLIMB WAS BECAUSE THESE EARLY MORNING CLOUDS THAT HAVE KEPT
SOME READINGS UP.
TONIGHT/FRIDAY...
THE HIGH PRESSURE WILL EXPAND EAST INTO THE MID-MISSISSIPPI
VALLEY BY LATE THIS EVE AND WEAKEN SLOWLY AS IT DOES. WE SHOULD
MAINTAIN SOME WIND COMPONENT...ALTHOUGH SUSPECT THAT GUIDANCE MAY
BE TOO HIGH ON WIND SPEEDS AS THEY OFTEN CAN BE AT NIGHT AND OVER
SNOW COVER. EVEN WITH 5-8 KT WINDS...WIND CHILL ADVISORY CRITERIA
LOOKS TO BE REACHED IN A GOOD PART OF THE AREA THAT IS UNDER THE
CURRENT WIND CHILL ADVISORY. AS FOR ACROSS THE SOUTHERN FORECAST
AREA...WHICH IS CLOSEST TO THE ACTIVE JET ACROSS THE SOUTHERN
U.S...THERE WILL LIKELY BE AT LEAST SOME THIN CIRRUS...IF NOT
BROKEN. SO A BIT MORE MARGINAL THERE. HAVE GONE WITH A WIND CHILL
ADVISORY FOR TONIGHT/FRIDAY IN THE CURRENT ADVISORY AREA TO GET
THE MESSAGE OUT. WILL LET DAY SHIFT ASSESS IF IT NEEDS TO BE
EXPANDED EAST...INCLUDING INTO THE CHICAGO METRO AREA. SOUTHWEST
FLOW GRADUALLY STARTS TO ENVELOP THE AREA FRIDAY BEHIND THE
HIGH...SO A HANDFUL OF DEGREES ARE EXPECTED TO BE ADDED TO TODAYS
HIGHS...WITH 10 TO 15 FORECAST ON FRIDAY.
SATURDAY/SATURDAY NIGHT...
GOOD AGREEMENT IN GUIDANCE ON MASS FIELDS REMAINS THE CASE THROUGH
THE FIRST HALF OF THE WEEKEND...WITH A STRONG WESTERLY UPPER JET
MOVING OVER THE WEST COAST AND ADVANCING EAST INTO THE CENTRAL
PLAINS. A QUICK-MOVING SORT OF HYBRID PACIFIC/CLIPPER SYSTEM IS
EXPECTED TO PROGRESS WITH THE LEFT EXIT REGION OF THIS INTO THE
AREA. DIFFERENCES DO EXIST IN GUIDANCE IN HOW IT EVOLVES THE LOW-
LEVEL FEATURES...WITH THE 00Z/06Z NAM BEING 10MB DEEPER THAN THE
00Z EC ON THE SURFACE WAVE...AND ACTUALLY THE ONLY MODEL SHOWING A
DEEPENING TREND IN THE SFC WAVE AS IT MOVES EAST OVER THE FORECAST
AREA. WHILE THE NAM CAN BE A BIT ROBUST ON DAY 3 IT SEEMS...THE
PV ANOMALY ASSOCIATED WITH THE UPPER TROUGH IS QUITE STRONG AND
ITS ORIENTATION WOULD FAVOR A LOW TO AT LEAST HOLD ITS INTENSITY
AS IT MOVES OVER THE AREA. SO AGAIN LEAN WITH THE MIDDLE GROUND
00Z GFS...WHICH ALSO HAS A MIDDLE GROUND QPF FORECAST.
THE IMPRESSIVE FEATURE WITH THIS IS THE MID-LEVEL VORT MAGNITUDE
AND ITS ADVECTION...DIRECTLY OVER AT LEAST PART OF THE FORECAST AREA
ON GUIDANCE...AND IT TIGHTENS THE BAROCLINIC ZONE TO WHERE IT
WOULD SEEM TEMPORARY BANDING COULD BE A CONCERN. THE GFS ALSO WOULD
SUGGEST THE DENDRITIC GROWTH ZONE IS LIKELY TO BE TAPPED AND GIVEN
A LIMITED RETURN FLOW PERIOD...WOULD EXPECT THE COLUMN TO BE COOL
ENOUGH TO PRESENT THIS AS A POSSIBLE CONCERN. SO HAVE GONE TOWARD
15:1 RATIOS IN INITIAL SNOW FORECAST. VORT MAGNITUDE USING
EMPIRICAL LEMO TECHNIQUE WOULD SUPPORT AT LEAST A FEW INCH STRIPE
OF SNOW SOMEWHERE...BUT WE WILL HAVE TO SEE AS WE GET CLOSER...AS
DURATION OF SNOW COULD OVERALL BE LIMITED IF EARLY SATURATION IS
AN ISSUE. WHILE CONTINUED THE TREND TO INCH UP POPS...NOW WITH 70
PERCENTS ACROSS MUCH OF NORTHERN IL ON SATURDAY. DID NOT GET FANCY
TRYING TO BREAK OUT MORNING VS AFTERNOON...BUT SOME TEMPORAL
RESOLUTION WILL INEVITABLY BE ABLE TO BE ADDED IN TIME.
SUNDAY AND BEYOND...
NORTHWEST FLOW ALOFT REMAINS FORECAST DURING EARLY NEXT
WEEK...WITH COLD AIR ADVECTION DEVELOPING BEHIND THE SATURDAY
SYSTEM. SUNDAY NIGHT/MONDAY MORNING COULD VERY WELL BE A PERIOD OF
WIND CHILL CONCERNS AGAIN. THE 925MB TEMPERATURES IN THE -15C TO
-20C RANGE ONCE AGAIN COULD SUPPORT NEGATIVE DOUBLE DIGIT LOWS IN
MOST OUTLYING AREAS ON MONDAY NIGHT WHERE LONG RANGE GUIDANCE
INDICATES HIGH PRESSURE AND A CLEAR SKY OVER THE FRESHENED SNOW
PACK. HAVE LEANED TOWARD A RAW BLEND OF GUIDANCE /NO MOS/ IN THAT
PERIOD...AND EVEN UNDERCUT THAT BY A FEW DEGREES. WITH THE HIGH
PRESSURE AND DEGREE OF SUBSIDENCE MOVING OVERHEAD IT LOOKS LIKE A
POSSIBLE MINI-PERIOD OF DRY WEATHER /OUTSIDE OF FLURRIES/ DURING
SUN THROUGH TUE...AT LEAST AT THIS TIME.
MTF
&&
.CLIMATE...
RECORD COLD HIGHS FOR TODAY FEBRUARY 6TH:
ROCKFORD: 3 DEGREES (1982)
WHILE THIS IS NOT LIKELY TO BE BROKEN TODAY...THE TEMPERATURE AT
MIDNIGHT WAS 2 DEGREES AND IT COULD BE CLOSE THIS AFTERNOON.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* NONE.
KREIN
//DISCUSSION...UPDATED 12Z...
A FAIRLY QUIET WEATHER DAY ON TAP WITH VFR CONDITIONS AND WEST FLOW
PREVAILING. SOME LINGERING FLURRIES AND MVFR CIGS PERSIST OVER
PORTIONS OF THE CHICAGO METRO THIS MORNING BUT ARE PROGGED TO MOVE
OUT EARLY THIS MORNING. RAP 900-925 RH HAS HAD A DECENT HANDLE ON
THE PROGRESSION THIS MORNING AND INDICATES CLEARING SHORTLY. THERE
MAY BE SOME COLD AIR CU THAT REDEVELOPS TODAY BETWEEN 020-025...BUT
ANTICIPATE IT BEING FEW TO SCT IN COVERAGE IF IT EVEN DEVELOPS.
GUSTS WILL ALSO PICK UP LATER IN THE MORNING THROUGH THE
AFTERNOON...INTO THE MID POSSIBLY UPPER TEENS. WINDS WILL TAPER
AGAIN IN THE EVENING AROUND SUNSET.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* HIGH CONFIDENCE IN ALL FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...VFR.
SATURDAY...SNOW LIKELY WITH SOME ACCUMULATION. IFR PSBL.
SUNDAY THROUGH WEDNESDAY...VFR LIKELY.
BMD
&&
.MARINE...
258 AM CST
AN EXPANSIVE AREA OF HIGH PRESSURE SPANS FROM THE CANADIAN ROCKIES
ACROSS THE CENTRAL PLAINS WITH A RIDGE EXTENDING EAST ALONG THE OHIO
RIVER VALLEY. WITH LOW PRESSURE SPINNING OVER HUDSON BAY...THIS WILL
LEAVE LAKE MICHIGAN IN A PERIOD OF MODERATE WESTERLY FLOW STARTING
LATER TODAY AS WINDS RAMP BACK UP TO AROUND 30 KT. WITH TEMPS
FALLING INTO THE SINGLE DIGITS ACROSS MAINLY THE NORTH HALF OF THE
LAKE...CONDITIONS ARE FAVORABLE FOR FREEZING SPRAY TO DEVELOP. THE
THREAT WILL DIMINISH FRIDAY NIGHT AS THE WINDS BEGIN TO SUBSIDE. LOW
PRESSURE WILL MOVE ACROSS THE SOUTHERN LAKE REGION OVER THE
WEEKEND...WITH ANOTHER COLD CANADIAN HIGH BUILDING BACK INTO THE
MIDWEST AND GREAT LAKES EARLY NEXT WEEK WITH LIGHT FLOW EXPECTED.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WIND CHILL ADVISORY...ILZ003-ILZ004-ILZ005-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ019-ILZ020-ILZ021-ILZ032 UNTIL 10 AM THURSDAY.
WIND CHILL ADVISORY...ILZ003-ILZ004-ILZ005-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ019-ILZ020-ILZ021-ILZ032...9 PM THURSDAY TO 11 AM
FRIDAY.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
531 AM CST THU FEB 6 2014
.DISCUSSION...
333 AM CST
THIS FORECAST WAS FOCUSED ON CURRENT COLD AIR THROUGH FRIDAY AS
WELL AS THE NEXT ROUND EARLY NEXT WEEK...WITH A SNOW EVENT
SANDWICHED IN-BETWEEN ON SATURDAY. THERE SURE HAVE BEEN PLENTY OF
THESE COLD-SNOW-COLD SANDWICHES THIS WINTER!
TODAY...
FROM A MASSIVE STORM SYSTEM YESTERDAY MORNING TO A MASSIVE HIGH
PRESSURE THIS MORNING...THE PROGRESSIVE FLOW CONTINUES. THIS
MORNINGS HIGH CENTERED AT 1043MB FROM MT INTO THE CENTRAL PLAINS
IS TRYING TO NUDGE ITS WAY INTO THE AREA. AT THE LEADING EDGE OF
THE 850-925MB THERMAL TROUGH THERE HAVE BEEN UNDULATING POCKETS OF
STRATOCU WITH FLURRIES EARLY THIS MORNING OVER THE FORECAST AREA.
THE RAP ANALYZES THIS WELL AND PROPAGATES THIS CAA/RH EAST OF
THE AREA BY MID-MORNING. COULD BE SOME FEW-SCT FINGERS OF CU TO
REDEVELOP TODAY AS COLD AIR ADVECTION AT THE TOP OF THE MIXED LAYER
CONTINUES THROUGH EARLY AFTERNOON. THIS ALSO COULD BE REALIZED AT
THE SFC WITH TEMPS STEADY OR EVEN SLOWLY DROPPING THROUGH 9-10 AM
IN SOME COMMUNITIES. THE REBOUND WILL BE SMALL TODAY WITH HIGHS
IN THE 5 TO THE 10 ABOVE RANGE...WITH MAYBE 12-14 IN DOWNTOWN
CHICAGO. THOSE ARE A COUPLE-FEW DEGREES HIGHER THAN INHERITED AND
THIS CLIMB WAS BECAUSE THESE EARLY MORNING CLOUDS THAT HAVE KEPT
SOME READINGS UP.
TONIGHT/FRIDAY...
THE HIGH PRESSURE WILL EXPAND EAST INTO THE MID-MISSISSIPPI
VALLEY BY LATE THIS EVE AND WEAKEN SLOWLY AS IT DOES. WE SHOULD
MAINTAIN SOME WIND COMPONENT...ALTHOUGH SUSPECT THAT GUIDANCE MAY
BE TOO HIGH ON WIND SPEEDS AS THEY OFTEN CAN BE AT NIGHT AND OVER
SNOW COVER. EVEN WITH 5-8 KT WINDS...WIND CHILL ADVISORY CRITERIA
LOOKS TO BE REACHED IN A GOOD PART OF THE AREA THAT IS UNDER THE
CURRENT WIND CHILL ADVISORY. AS FOR ACROSS THE SOUTHERN FORECAST
AREA...WHICH IS CLOSEST TO THE ACTIVE JET ACROSS THE SOUTHERN
U.S...THERE WILL LIKELY BE AT LEAST SOME THIN CIRRUS...IF NOT
BROKEN. SO A BIT MORE MARGINAL THERE. HAVE GONE WITH A WIND CHILL
ADVISORY FOR TONIGHT/FRIDAY IN THE CURRENT ADVISORY AREA TO GET
THE MESSAGE OUT. WILL LET DAY SHIFT ASSESS IF IT NEEDS TO BE
EXPANDED EAST...INCLUDING INTO THE CHICAGO METRO AREA. SOUTHWEST
FLOW GRADUALLY STARTS TO ENVELOP THE AREA FRIDAY BEHIND THE
HIGH...SO A HANDFUL OF DEGREES ARE EXPECTED TO BE ADDED TO TODAYS
HIGHS...WITH 10 TO 15 FORECAST ON FRIDAY.
SATURDAY/SATURDAY NIGHT...
GOOD AGREEMENT IN GUIDANCE ON MASS FIELDS REMAINS THE CASE THROUGH
THE FIRST HALF OF THE WEEKEND...WITH A STRONG WESTERLY UPPER JET
MOVING OVER THE WEST COAST AND ADVANCING EAST INTO THE CENTRAL
PLAINS. A QUICK-MOVING SORT OF HYBRID PACIFIC/CLIPPER SYSTEM IS
EXPECTED TO PROGRESS WITH THE LEFT EXIT REGION OF THIS INTO THE
AREA. DIFFERENCES DO EXIST IN GUIDANCE IN HOW IT EVOLVES THE LOW-
LEVEL FEATURES...WITH THE 00Z/06Z NAM BEING 10MB DEEPER THAN THE
00Z EC ON THE SURFACE WAVE...AND ACTUALLY THE ONLY MODEL SHOWING A
DEEPENING TREND IN THE SFC WAVE AS IT MOVES EAST OVER THE FORECAST
AREA. WHILE THE NAM CAN BE A BIT ROBUST ON DAY 3 IT SEEMS...THE
PV ANOMALY ASSOCIATED WITH THE UPPER TROUGH IS QUITE STRONG AND
ITS ORIENTATION WOULD FAVOR A LOW TO AT LEAST HOLD ITS INTENSITY
AS IT MOVES OVER THE AREA. SO AGAIN LEAN WITH THE MIDDLE GROUND
00Z GFS...WHICH ALSO HAS A MIDDLE GROUND QPF FORECAST.
THE IMPRESSIVE FEATURE WITH THIS IS THE MID-LEVEL VORT MAGNITUDE
AND ITS ADVECTION...DIRECTLY OVER AT LEAST PART OF THE FORECAST AREA
ON GUIDANCE...AND IT TIGHTENS THE BAROCLINIC ZONE TO WHERE IT
WOULD SEEM TEMPORARY BANDING COULD BE A CONCERN. THE GFS ALSO WOULD
SUGGEST THE DENDRITIC GROWTH ZONE IS LIKELY TO BE TAPPED AND GIVEN
A LIMITED RETURN FLOW PERIOD...WOULD EXPECT THE COLUMN TO BE COOL
ENOUGH TO PRESENT THIS AS A POSSIBLE CONCERN. SO HAVE GONE TOWARD
15:1 RATIOS IN INITIAL SNOW FORECAST. VORT MAGNITUDE USING
EMPIRICAL LEMO TECHNIQUE WOULD SUPPORT AT LEAST A FEW INCH STRIPE
OF SNOW SOMEWHERE...BUT WE WILL HAVE TO SEE AS WE GET CLOSER...AS
DURATION OF SNOW COULD OVERALL BE LIMITED IF EARLY SATURATION IS
AN ISSUE. WHILE CONTINUED THE TREND TO INCH UP POPS...NOW WITH 70
PERCENTS ACROSS MUCH OF NORTHERN IL ON SATURDAY. DID NOT GET FANCY
TRYING TO BREAK OUT MORNING VS AFTERNOON...BUT SOME TEMPORAL
RESOLUTION WILL INEVITABLY BE ABLE TO BE ADDED IN TIME.
SUNDAY AND BEYOND...
NORTHWEST FLOW ALOFT REMAINS FORECAST DURING EARLY NEXT
WEEK...WITH COLD AIR ADVECTION DEVELOPING BEHIND THE SATURDAY
SYSTEM. SUNDAY NIGHT/MONDAY MORNING COULD VERY WELL BE A PERIOD OF
WIND CHILL CONCERNS AGAIN. THE 925MB TEMPERATURES IN THE -15C TO
-20C RANGE ONCE AGAIN COULD SUPPORT NEGATIVE DOUBLE DIGIT LOWS IN
MOST OUTLYING AREAS ON MONDAY NIGHT WHERE LONG RANGE GUIDANCE
INDICATES HIGH PRESSURE AND A CLEAR SKY OVER THE FRESHENED SNOW
PACK. HAVE LEANED TOWARD A RAW BLEND OF GUIDANCE /NO MOS/ IN THAT
PERIOD...AND EVEN UNDERCUT THAT BY A FEW DEGREES. WITH THE HIGH
PRESSURE AND DEGREE OF SUBSIDENCE MOVING OVERHEAD IT LOOKS LIKE A
POSSIBLE MINI-PERIOD OF DRY WEATHER /OUTSIDE OF FLURRIES/ DURING
SUN THROUGH TUE...AT LEAST AT THIS TIME.
MTF
&&
.CLIMATE...
RECORD COLD HIGHS FOR TODAY FEBRUARY 6TH:
ROCKFORD: 3 DEGREES (1982)
WHILE THIS IS NOT LIKELY TO BE BROKEN TODAY...THE TEMPERATURE AT
MIDNIGHT WAS 2 DEGREES AND IT COULD BE CLOSE THIS AFTERNOON.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* NONE
BMD
//DISCUSSION...UPDATED 12Z...
A FAIRLY QUIET WEATHER DAY ON TAP WITH VFR CONDITIONS AND WEST FLOW
PREVAILING. SOME LINGERING FLURRIES AND MVFR CIGS PERSIST OVER
PORTIONS OF THE CHICAGO METRO THIS MORNING BUT ARE PROGGED TO MOVE
OUT EARLY THIS MORNING. RAP 900-925 RH HAS HAD A DECENT HANDLE ON
THE PROGRESSION THIS MORNING AND INDICATES CLEARING SHORTLY. THERE
MAY BE SOME COLD AIR CU THAT REDEVELOPS TODAY BETWEEN 020-025...BUT
ANTICIPATE IT BEING FEW TO SCT IN COVERAGE IF IT EVEN DEVELOPS.
GUSTS WILL ALSO PICK UP LATER IN THE MORNING THROUGH THE
AFTERNOON...INTO THE MID POSSIBLY UPPER TEENS. WINDS WILL TAPER
AGAIN IN THE EVENING AROUND SUNSET.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* HIGH CONFIDENCE IN ALL FORECAST ELEMENTS.
BMD
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...VFR.
SATURDAY...SNOW LIKELY WITH SOME ACCUMULATION. IFR PSBL.
SUNDAY THROUGH WEDNESDAY...VFR LIKELY.
BMD
&&
.MARINE...
258 AM CST
AN EXPANSIVE AREA OF HIGH PRESSURE SPANS FROM THE CANADIAN ROCKIES
ACROSS THE CENTRAL PLAINS WITH A RIDGE EXTENDING EAST ALONG THE OHIO
RIVER VALLEY. WITH LOW PRESSURE SPINNING OVER HUDSON BAY...THIS WILL
LEAVE LAKE MICHIGAN IN A PERIOD OF MODERATE WESTERLY FLOW STARTING
LATER TODAY AS WINDS RAMP BACK UP TO AROUND 30 KT. WITH TEMPS
FALLING INTO THE SINGLE DIGITS ACROSS MAINLY THE NORTH HALF OF THE
LAKE...CONDITIONS ARE FAVORABLE FOR FREEZING SPRAY TO DEVELOP. THE
THREAT WILL DIMINISH FRIDAY NIGHT AS THE WINDS BEGIN TO SUBSIDE. LOW
PRESSURE WILL MOVE ACROSS THE SOUTHERN LAKE REGION OVER THE
WEEKEND...WITH ANOTHER COLD CANADIAN HIGH BUILDING BACK INTO THE
MIDWEST AND GREAT LAKES EARLY NEXT WEEK WITH LIGHT FLOW EXPECTED.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WIND CHILL ADVISORY...ILZ003-ILZ004-ILZ005-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ019-ILZ020-ILZ021-ILZ032 UNTIL 10 AM THURSDAY.
WIND CHILL ADVISORY...ILZ003-ILZ004-ILZ005-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ019-ILZ020-ILZ021-ILZ032...9 PM THURSDAY TO 11 AM
FRIDAY.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
300 AM CST THU FEB 6 2014
.DISCUSSION...
324 PM CST
THE MAIN FORECAST CONCERNS WILL BE WITH WIND CHILLS TONIGHT AND
AGAIN THURSDAY NIGHT AS AN ARCTIC SURFACE HIGH DOMINATES ACROSS THE
CENTRAL CONUS.
...HAVE ISSUED A WIND CHILL ADVISORY FOR WESTERN SECTIONS OF THE
AREA FOR LATE TONIGHT THROUGH LATE MORNING THURSDAY...
LAKE EFFECT SNOW SHOWERS CONTINUE ACROSS PORTIONS OF EASTERN
ILLINOIS...ESPECIALLY ACROSS SOUTHERN COOK AND INTO NORTHWESTERN
INDIANA. THIS ACTIVITY WILL WANE QUICKLY OVER THE NEXT COUPLE HOURS
ACROSS NORTHEASTERN ILLINOIS AS THE LAND-LAKE CONVERGENCE ZONE
CONTINUES TO SHIFT RAPIDLY TO THE EAST ACROSS NORTHWESTERN INDIANA.
THE LAKE EFFECT SNOW SHOWERS MAY LINGER FOR A SHORT PERIOD EARLY
THIS EVENING ACROSS PORTIONS OF LAKE AND PORTER COUNTY
INDIANA WITH SOME MINOR ACCUMULATIONS UP TO AN ADDITIONAL INCH
POSSIBLE...BUT THIS ACTIVITY WILL ALSO ABATE BY MID TO LATE EVENING
AS THE FLOW ACROSS THE LAKE BACKS MORE NORTHWESTERLY.
IT APPEARS THAT PERIODS OF VERY LIGHT SNOW SHOWERS AND FLURRIES MAY
CONTINUE TONIGHT ACROSS MUCH OF THE AREA AS THE REGION REMAINS IN A
RATHER DISTURBED MID AND UPPER LEVEL WESTERLY FLOW ALONG THE
NORTHERN FRINGE OF A 110+ KT UPPER LEVEL JET. SEVERAL UPSTREAM OBS
ACROSS IOWA AND MINNESOTA HAVE INDICATED PERIODS OF FLURRIES...AND I
WOULD EXPECT TO TO BE THE CASE ACROSS MUCH OF MY AREA TONIGHT AS
WELL. MODEL BUFFER SOUNDINGS SUGGEST THAT LOWER LEVEL SATURATION
WILL BE SUFFICIENT TO SQUEEZE OUT AT LEAST SOME FLURRIES.
OTHERWISE...AS MENTIONED ABOVE...I ISSUED A WIND CHILL ADVISORY FOR
THE WESTERN HALF OF MY CWA. MY NEIGHBORS TO THE SOUTH AND EAST HAVE
SLIGHTLY LOWER CRITERIA FOR WIND CHILL ADVISORIES...HENCE THE GAP IN
THE ADVISORY ACROSS MY SOUTHEASTERN COUNTIES. I CHOOSE NOT TO PUT
THESE AREAS IN AN ADVISORY DUE TO THE FACT THAT IT DOES NOT APPEAR
TO BE QUITE AS COLD THERE AS PREVIOUSLY THOUGHT DUE TO CLOUD COVER
AND A GRADIENT THAT WILL LIKELY KEEP WINDS UP AROUND 10 MPH FOR MUCH
OF THE NIGHT. FOR THESE REASONS IT WILL BE ADVECTION ALONE AND NOT
RADIATIONAL COOLING THAT WILL LEAD TO THE COLD TEMPERATURES ACROSS
THE AREA. GIVEN THAT THE AIR MASS...WHICH WAS SLIGHTLY COLDER ACROSS
MINNESOTA THIS MORNING PRODUCED LOWS AROUND -5...I THINK THESE
VALUES WILL OCCUR ACROSS MY NORTH CENTRAL ILLINOIS COUNTIES...WITH
VALUES LIKELY NEAR ZERO IN MY SOUTHEASTERN COUNTIES. OVERALL THIS
WILL YIELD WIND CHILLS AS LOW AS -25 NORTH CENTRAL TO AROUND -15
ACROSS MY SOUTHEASTERN COUNTIES. THE EVENING SHIFT CAN WATCH TRENDS
TONIGHT AND EXPAND THE ADVISORY IF NECESSARY.
COLD CONDITIONS WILL CONTINUE ON THURSDAY AS THE 1040 MB SURFACE HIGH
SHIFTS EASTWARD FROM THE PLAINS ACROSS THE LOWER MISSOURI RIVER
VALLEY. THIS COULD YIELD WIND CHILLS IN EXCESS OF -20 ACROSS MOST OF
MY CWA INTO FRIDAY MORNING AS ACTUALLY LOW TEMPS FALL SEVERAL
DEGREES BELOW ZERO.
A STRONG 120+ KT WESTERLY UPPER LEVEL JET WILL DEVELOP ACROSS THE
EASTERN PACIFIC AND ACROSS THE PACIFIC NORTHWEST LATER THIS WEEK AS
THE THE LARGE SCALE WEATHER PATTERN ACROSS THE NORTH PACIFIC SHIFTS.
THIS WILL SET THE STAGE FOR MULTIPLE DISTURBANCES TO EJECT EASTWARD
ACROSS THE PLAINS STATES THROUGH THE EXTENDED PERIOD. IT APPEARS
THAT ONE OF THESE DISTURBANCES MAY TAKE A TRACK EASTWARD IN A
FAVORABLE AREA FOR SOME MORE ACCUMULATING SNOW ACROSS THE AREA ON
SATURDAY. HOWEVER...AT THIS TIME THIS DOES NOT APPEAR TO BE A MAJOR
SNOW MAKER FOR THE AREA.
OTHERWISE...THE REST OF THE EXTENDED PERIOD APPEARS TO REMAIN COLDER
THAN AVERAGE. THERE WILL BE MORE POTENTIALS FOR PRECIPITATION EARLY
TO THE MIDDLE PART OF NEXT WEEK AS THE WEATHER PATTERN REMAINS
ACTIVE. HOWEVER...AT THIS TIME THERE ARE TO MANY UNCERTAINTIES IN HOW
FAR NORTH PRECIPITATION MAY GET...WITH THE POSSIBILITY OF MUCH OF THE
PRECIPITATION BEING LOCK UP TO THE SOUTH OF THE AREA. CONFIDENCE IS
LOW AT THIS TIME...AND ANY NORTHWARD SHIFT IN THE FAVORED TRACK OF
THESE SOUTHERN TRACKED SYSTEMS COULD PRODUCE SNOW INTO NORTHERN
ILLINOIS.
KJB
&&
.CLIMATE...
RECORD COLD HIGHS FOR THURSDAY FEBRUARY 6TH:
ROCKFORD: 3 DEGREES (1982)
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 09Z...
* LIGHT SNOW AND PATCHY MVFR THIS EVENING...TAPERING OVER NEXT
HOUR.
BMD
//DISCUSSION...UPDATED 09Z...
MVFR CIGS/FLURRIES LINGERED LONGER THAN EXPECTED. RAP SEEMS TO
HAVE DECENT HAND ON WHATS GOING ON...AND HAVE EXPANDED TIMING OF
FLURRIES TO BETTER MATCH UP. CIGS ARE GENERALLY IN THE 025-030
RANGE AND DO NOT ANTICIPATE VSBY TO DROP BELOW 6SM.
PREVIOUS DISCUSSION 06Z...
STEEP LOW LEVEL LAPSE RATES OVER THE AREA HAVE RESULTED IN A PATCH OF
CLOUDS MOVING OVER THE AREA WHICH ARE PRODUCING A FEW FLURRIES. THESE
WILL BE SHORT LIVED THOUGH AS THEY PROGRESS EAST ACROSS THE AREA AND
FLAT UPPER LEVEL RIDGING WILL RESULT IN SUBSIDENCE AND DRYING OF THE
AIRMASS...SO DO NOT EXPECT ADDITIONAL DEVELOPMENT OVERNIGHT. WINDS
WILL BE PRIMARILY WESTERLY THOUGH THE PERIOD AS A STRONG HIGH BUILDS
TO THE SOUTH OF THE TERMINALS. GUSTS INTO THE MID TO UPPER TEENS ARE
EXPECTED TO DEVELOP MID TO LATE THURSDAY MORNING...AND END IN THE
EVENING. OUTSIDE OF THE PATCHY MVFR OVER THE NEXT HOUR OR
TWO...EXPECT THE REMAINDER OF THE PERIOD TO BE VFR.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 09Z...
* HIGH CONFIDENCE IN ALL FORECAST ELEMENTS.
BMD
//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...
FRIDAY...VFR LIKELY.
SATURDAY...SNOW/MVFR-IFR LIKELY.
SUNDAY THROUGH TUESDAY...VFR LIKELY.
ZEBIC
&&
.MARINE...
258 AM CST
AN EXPANSIVE AREA OF HIGH PRESSURE SPANS FROM THE CANADIAN ROCKIES
ACROSS THE CENTRAL PLAINS WITH A RIDGE EXTENDING EAST ALONG THE OHIO
RIVER VALLEY. WITH LOW PRESSURE SPINNING OVER HUDSON BAY...THIS WILL
LEAVE LAKE MICHIGAN IN A PERIOD OF MODERATE WESTERLY FLOW STARTING
LATER TODAY AS WINDS RAMP BACK UP TO AROUND 30 KT. WITH TEMPS
FALLING INTO THE SINGLE DIGITS ACROSS MAINLY THE NORTH HALF OF THE
LAKE...CONDITIONS ARE FAVORABLE FOR FREEZING SPRAY TO DEVELOP. THE
THREAT WILL DIMINISH FRIDAY NIGHT AS THE WINDS BEGIN TO SUBSIDE. LOW
PRESSURE WILL MOVE ACROSS THE SOUTHERN LAKE REGION OVER THE
WEEKEND...WITH ANOTHER COLD CANADIAN HIGH BUILDING BACK INTO THE
MIDWEST AND GREAT LAKES EARLY NEXT WEEK WITH LIGHT FLOW EXPECTED.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WIND CHILL ADVISORY...ILZ003-ILZ004-ILZ005-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ019-ILZ020-ILZ021-ILZ032 UNTIL 10 AM THURSDAY.
WIND CHILL ADVISORY...ILZ003-ILZ004-ILZ005-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ019-ILZ020-ILZ021-ILZ032...9 PM THURSDAY TO 11 AM
FRIDAY.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
940 AM EST THU FEB 6 2014
.SYNOPSIS...
A WEAK DISTURBANCE WILL CROSS THE GREAT LAKES REGION TODAY
FOLLOWED BY HIGH PRESSURE LATE TONIGHT AND FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FOR THE MORNING UPDATE...MADE SOME ADJUSTMENTS TO
TEMPS...SKY...AND POPS BASED ON SATELLITE...RADAR...AND SURFACE
OBSERVATIONS. SOME SCATTERED FLURRIES CONTINUE TO LINGER IN
NORTHWEST FLOW...ESPECIALLY IN THE RIDGES WITH THE HELP OF
UPSLOPE...BUT THIS SHOULD BEGIN TO TAPER OFF SHORTLY AS INVERSION
HEIGHTS FALL.
ANOTHER WEAK TROUGH WILL CROSS THE GREAT LAKES TODAY BUT WITH
LITTLE MOISTURE...NO PRECIPITATION IS EXPECTED. TEMPERATURES WILL
REMAIN BELOW SEASONAL AVERAGES WITH HIGHS IN THE TWENTIES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
THE WK TROF MAY BRING A FEW FLURRIES N AND E OF PIT THIS
EVE...OTRW HIGH PRES WL GRDLY BLD IN THRU FRI. MOISTURE BEGINS TO
INCR SAT ON THE NRN PERIPHERY OF A LOW OFF THE SE COAST...AND IN
ADVANCE OF ANOTHER SHRTWV ACRS THE MD WEST. MDL PROGS DO NOT PHASE
THESE TWO SYSTEMS...THEREFORE ONLY CHC POPS FCST FOR SAT FOR SNW
AS UPR SPPRT IS LACKING. AS THE MD WEST SHRTWV CROSSES THE RGN SAT
NGT...WENT WITH LIKELY POPS FOR LGT SNW WITH SUFFICENT UPR SPPRT
AND MOISTURE. ANOTHER FAST MOVG SHRTWV CROSSES THE GT LKS/UPR OH
VLY SUN...WITH CHC POPS MAINTAINED DUE TO QN IN TIMING AND AVAIL
UPR SPPRT. TEMPS SHOULD REMAIN BLO SEASONAL AVGS THRU THE PD.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
LONG TERM FORECAST WAS CONSTRUCTED USING WPC GUIDANCE WITH GENLY
DRY AND SEASONABLY COLD CONDITIONS UNTIL FORMATION OF MID ATLANTIC
LOW PRES BY MID WEEK...WHICH COULD SPREAD MORE SNOW ACRS THE UPR
OH REGION. CHC POPS WERE INCLUDED FOR THAT SCENARIO...BUT
CONFIDENCE IS MINIMAL AT MOMENT GIVEN THE TIMING AND DIFFERENCES
IN MDL TRENDS.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
MVFR STRATOCU WL CONT TO FLOW ACRS UPR OHIO TERMINALS THIS MRNG AS
COLD ADVCTN ON WEAKENING NW BNDRY LYR FLOW PERSISTS. AS THAT FLOW
DRIES AND BACKS...EXPECT IMPROVEMENT TO VFR.
WEAK DISTURBANCE IS PROGGED TO INCRS MID LVL CLDS THIS AFTN ALNG
WITH SOME FLAT STRATOCU GIVEN THE LOW CONVECTIVE THRESHOLDS. WL
FOLLOW THE LATEST HRRR TRENDS AND REINTRODUCE MVFR CONDITIONS FOR
THE AFTN.
.OUTLOOK..../THURSDAY THROUGH MONDAY/...
A SERIES OF DISTURBANCES WL INCRS PCPN AND RESTRICTION CHCS THIS
WEEKEND.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BISMARCK ND
940 AM CST THU FEB 6 2014
.UPDATE...
ISSUED AT 925 AM CST THU FEB 6 2014
UPDATE FOR SKY COVER AND TEMPERATURE TRENDS...AND TO EXPAND AREA
OF FLURRIES INTO THE AFTERNOON SOUTHEAST. LOWERED TEMPS...MAINLY
SOUTHWEST DUE TO THE MUCH COLDER START TO THE DAY. LAYER RH PROGS
FROM THE 13KM RAP SUGGEST CLOUDS LINGERING MAINLY ACROSS THE EAST
INTO THIS AFTERNOON. WIND CHILL ADVISORY CONTINUES THROUGH THE MORNING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 352 AM CST THU FEB 6 2014
DANGEROUS WIND CHILLS HIGHLIGHT THE SHORT TERM FORECAST.
FOR THIS MORNING...A BROAD DECK OF STRATUS WILL CONTINUE TO
OVERSPREAD WESTERN AND CENTRAL NORTH DAKOTA. THIS HAS HELPED TO
KEEP OVERNIGHT LOWS GENERALLY IN THE -5 TO -10 RANGE FOR MOST
LOCATIONS UNDER THE DECK. AS A RESULT...WIND CHILLS ARE LOW END
WIND CHILL ADVISORY CRITERIA IN THE -25 TO -30 RANGE FOR MOST
LOCATIONS. AS THE DECK IS ERODED FROM WEST TO EAST BY THE LATE
MORNING AND THROUGH THE AFTERNOON WITH INCREASING WESTERLY WINDS
...INSOLATION SHOULD ALLOW FOR HIGHS OF 5 TO 10 ABOVE. THIS WOULD
RESULT IN WIND CHILLS WARMING ABOVE ADVISORY CRITERIA ON SCHEDULE
BY 18 UTC. LIKE YESTERDAY...DID ADD A MENTION OF FLURRIES UNDER
THE STRATUS.
FOR TONIGHT...A SURFACE RIDGE AXIS WILL BE IN PLACE ACROSS THE
DAKOTAS...WITH CLEAR SKIES. THE ONE LIMIT TO OVERNIGHT COOLING WILL
BE MIXING ON THE ORDER OF 10-15 KTS. THUS TRENDED TOWARDS THE
WARMER EDGE OF GUIDANCE...THE CONSENSUS OF THE 00 UTC
DETERMINISTIC MODELS...FOR LOWS OVERNIGHT GENERALLY IN THE -5 TO
-10 RANGE. WHEN COMBINED WITH WINDS...SOME LOCATIONS HAVE WIND
CHILLS IN THE -25 TO -30 RANGE. WILL ALLOW FURTHER SHIFTS TO
EVALUATE IF A WIND CHILL ADVISORY WILL BE NEEDED FOR TONIGHT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 352 AM CST THU FEB 6 2014
NO SIGNIFICANT CHANGES TO THIS TIME PERIOD WITH COLD
AND MOSTLY DRY WEATHER CONTINUING INTO NEXT WEEK BEFORE TEMPERATURES
BEGIN TO MODERATE AND LOW CHANCES OF PRECIP RETURN.
MODELS ARE IN GOOD AGREEMENT WITH 500MB FLOW INITIALLY SHOWING SPLIT
FLOW IN PLACE. HUDSON BAY LOW SHIFTS EASTWARD DURING THE WEEKEND
WITH BROAD TROUGH OVER EASTERN NORTH AMERICA AND RIDGE OVER THE WEST
LEAVING NORTHERN PLAINS IN NORTHWEST FLOW ALOFT INTO EARLY NEXT
WEEK. BOTH GFS/ECMWF SHOW SHORTWAVE IN NW FLOW CROSSING OUR REGION
AROUND TUESDAY AND RELATIVELY WEAK SURFACE LOW...THOUGH SOME TIMING
AND LOCATION DIFFERENCES EXIST. CONTINUE TO CARRY SOME LOW POPS FOR
THIS TIME PERIOD.
WITH REGARD TO COLD WEATHER...WIND CHILL VALUES DROP TO -25 TO -30
RANGE FRIDAY NIGHT MAINLY ACROSS THE NORTH AND INTO NORTHERN JAMES
RIVER VALLEY. WIND CHILLS ARE FORECAST A LITTLE COLDER ON SATURDAY
NIGHT RANGING FROM -30 TO -35 DEGREES MAINLY EAST AND NORTH OF THE
MISSOURI RIVER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 925 AM CST THU FEB 6 2014
MVFR CEILINGS AND A FEW LIGHT SNOW SHOWERS WILL CONTINUE THROUGH
THE MORNING HOURS. CLEARING TREND EXPECTED FROM WEST TO EAST
ACROSS THE STATE THIS AFTERNOON AND EVENING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL 1 PM CST /NOON MST/ THIS AFTERNOON FOR
NDZ001>005-009>013-017>023-025-031>037-040>048-050-051.
&&
$$
UPDATE/AVIATION...RP KINNEY
SHORT TERM...AYD
LONG TERM...JNS
AREA FORECAST DISCUSSION...UPDATED
NWS MORRISTOWN TN
927 AM EST THU FEB 6 2014
.DISCUSSION...
LIGHT SNOW IS PERSISTING ACROSS PORTIONS OF SW VA THIS MORNING. IT
SHOULD BEGIN TO TAPER OFF IN THE EARLY AFTERNOON AS RUC SOUNDINGS
SHOW A DRYING TREND ALOFT. NO SIGNIFICANT ACCUMULATION IS
EXPECTED...BUT WILL UPDATE TO ADD A POP MENTION THROUGH EARLY
AFTERNOON. TEMPERATURES WILL ALSO NEED TO BE ADJUSTED DOWNWARD
ACROSS THE ENTIRE AREA BASED ON CLOUD COVER AND LATEST GUIDANCE.
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
DGS
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
942 AM CST THU FEB 6 2014
.UPDATE...
WE HAVE LOWERED TODAY/S HIGH TEMPERATURES BY A FEW DEGREES ACROSS
MOST OF THE REGION. THE LATEST RUC13 AND SREF MODEL DATA SUGGESTS
HIGHS WILL REMAIN IN THE 30S ACROSS MOST AREAS...WITH TEMPS
STRUGGLING TO REACH FREEZING OVER THE HILL COUNTRY. HIGHS ALONG
THE I-35 CORRIDOR WILL STRUGGLE TO REACH THE MID 30S. NO CHANGES
TO THE WINTER WEATHER ADVISORY JUST YET AS THE LATEST RADAR DATA
CONTINUES TO SHOW SOME LIGHT ECHOES ACROSS THE HILL COUNTRY SLOWLY
MOVING INTO THE I-35 CORRIDOR. WE COULD SEE SOME LIGHT SNOW OR
GRAUPEL FROM THIS ACTIVITY. GIVEN THE LIGHT RADAR RETURNS...WOULD
NOT EXPECT ANY SIGNIFICANT ACCUMULATIONS FROM THIS ACTIVITY.
&&
.PREV DISCUSSION... /ISSUED 547 AM CST THU FEB 6 2014/
AVIATION...
VFR CONDITIONS AT I-35 SITES WITH MVFR AT KDRT. EXPECT THIS TREND
TO CONTINUE WITH COLD HIGH PRESSURE IN CONTROL OVER THE REGION.
ALL SLEET AND LIGHT SNOW SHOULD BE OUT OF THE AREA BY 14Z. CLOUDS
SHOULD REMAIN IN THE 4-6 THOUSAND FOOT RANGE THIS AFTERNOON.
CEILINGS WILL LOWER TO 2-4 THOUSAND FEET AFTER 01Z FRIDAY. AFTER
08Z TONIGHT WILL SEE ANOTHER UPPER LEVEL SYSTEM MOVE ACROSS WITH
LOW CHANCES FOR LIGHT FREEZING DRIZZLE. CURRENTLY FEEL THAT ANY
ACCUMULATIONS WOULD BE MINOR. NORTHERLY WINDS WILL DECREASE TO 10
TO 15 KNOTS THIS MORNING AND NEAR 10 KNOTS THIS AFTERNOON AND
OVERNIGHT.
PREV DISCUSSION... /ISSUED 525 AM CST THU FEB 6 2014/
UPDATE...
HAVE ISSUED A WINTER WEATHER ADVISORY FOR A BAND OF SLEET AND SNOW
FROM NORTHERN SAN ANTONIO ACROSS THE NEW BRAUNFELS AND SAN MARCOS
AREAS...THEN EAST TO LA GRANGE AND LEXINGTON. SLEET AND SNOW
ACCUMULATIONS UP TO ONE HALF INCH ARE POSSIBLE. THE BAND WILL MOVE
EAST BY 11 AM.
PREV DISCUSSION... /ISSUED 424 AM CST THU FEB 6 2014/
UPDATE...
ADDED MENTION OF SLEET FOR A BAND FROM HONDO TO SAN ANTONIO TO
BASTROP TO GIDDINGS. A DUSTING MAY BE POSSIBLE WITH THIS BAND.
PREV DISCUSSION... /ISSUED 341 AM CST THU FEB 6 2014/
SHORT TERM (TODAY THROUGH FRIDAY)...
COLD ADVECTION CONTINUES ACROSS SOUTH CENTRAL TEXAS EARLY THIS
MORNING AS AN UPPER LEVEL TROUGH MOVES ACROSS THE BIG BEND REGION.
ISENTROPIC LIFT ASSOCIATED WITH THIS TROUGH WILL GENERATE VERY
LIGHT PRECIPITATION. CURRENT AND FORECAST SOUNDING DATA SHOW THAT
SNOW FLURRIES ARE THE LIKELY PRECIPITATION TYPE. NO ACCUMULATION
IS EXPECTED DUE TO A VERY DRY LOWER LEVEL AIRMASS. THE TROUGH WILL
MOVE NORTHEAST OF OUR AREA BY MIDDAY ENDING THE FLURRIES AS LIFT
ENDS. ANOTHER UPPER LEVEL TROUGH CURRENTLY SEEN APPROACHING THE
CALIFORNIA COAST WILL MOVE ACROSS TEXAS ON FRIDAY. ISENTROPIC LIFT
WILL DEVELOP LATE TONIGHT. A WARMER AND MORE MOIST AIRMASS ALOFT
WILL CREATE DRIZZLE OR FREEZING DRIZZLE. EVEN THOUGH MORE MOISTURE
WILL BE AVAILABLE...LITTLE OR NO ICE ACCUMULATION IS EXPECTED.
HOWEVER...A SLIGHTLY STRONGER SYSTEM WITH SLIGHTLY DEEPER MOISTURE
COULD PRODUCE LIGHT ICING ON BRIDGES...OVERPASSES AND OTHER
ELEVATED ROADS. SO...STAY TUNED FOR THE LATEST DEVELOPMENTS ON
THIS WEATHER EVENT. ISENTROPIC LIFT SLOWLY WANES WITH DRIZZLE
ENDING BY LATE FRIDAY EVENING. CLOUD COVER WILL MAKE TEMPERATURES
STRUGGLE TO REACH 40 MOST AREAS TODAY AND FRIDAY. AVERAGE HIGHS
ARE IN THE LOWER TO MID 60S.
LONG TERM (FRIDAY NIGHT THROUGH WEDNESDAY)...
SOUTHWESTERLY WINDS DEVELOP ON SATURDAY AS THE SURFACE HIGH MOVES
AWAY LEADING TO A WARM DAY WITH HIGHS NEAR OR JUST ABOVE AVERAGE.
THE MODELS HAVE BECOME MORE DISAGREEABLE FOR SUNDAY AND MONDAY.
THE GFS BRINGS A WEAK BACKDOOR COLD FRONT INTO OUR AREA SUNDAY AND
LIFTS IT BACK NORTH MONDAY WITH A STRONGER COLD FRONT TUESDAY
WHILE THE ECMWF BRINGS A MODERATELY COLD FRONT THROUGH SUNDAY
NIGHT WITH A STRONGER PUSH OF COLD AIR TUESDAY. BOTH MODELS SHOW
AN UPPER LEVEL TROUGH MOVING ACROSS TEXAS LATE TUESDAY INTO
TUESDAY NIGHT. FOR NOW...WILL SIDE WITH THE GFS ON THE FRONT.
WARM ADVECTION SHOWERS ARE POSSIBLE MONDAY INTO MONDAY NIGHT WITH
A SLIGHTLY BETTER CHANCE OF SHOWERS WITH THE UPPER LEVEL TROUGH
TUESDAY INTO TUESDAY NIGHT. COLD AND DRY AGAIN FOR WEDNESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 36 26 41 35 67 / 10 10 20 10 -
AUSTIN BERGSTROM INTL AIRPORT 36 24 39 33 66 / 10 10 20 10 -
NEW BRAUNFELS MUNI AIRPORT 36 27 38 33 68 / 20 10 20 10 -
BURNET MUNI AIRPORT 34 23 39 31 65 / 10 10 20 10 -
DEL RIO INTL AIRPORT 42 30 47 36 71 / 10 - - - -
GEORGETOWN MUNI AIRPORT 35 23 39 32 63 / 10 10 20 10 -
HONDO MUNI AIRPORT 39 28 42 34 70 / 10 10 20 10 -
SAN MARCOS MUNI AIRPORT 36 26 38 33 67 / 20 10 20 10 -
LA GRANGE - FAYETTE REGIONAL 39 29 39 35 63 / 20 10 20 20 10
SAN ANTONIO INTL AIRPORT 36 29 41 35 69 / 20 10 20 10 -
STINSON MUNI AIRPORT 36 30 40 34 69 / 10 10 20 10 -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 11 AM CST THIS MORNING FOR THE
FOLLOWING COUNTIES: BASTROP...BEXAR...CALDWELL...COMAL...FAYETTE...
GONZALES...GUADALUPE...HAYS...LEE.
&&
$$
MESOSCALE/AVIATION...25
SYNOPTIC/GRIDS...24
PUBLIC SERVICE/DATA COLLECTION...33
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
1020 AM PST Thu Feb 6 2014
.Synopsis...
Series of moist Pacific storms will impact Interior Northern
California today through early next week bringing rain...snow in
the mountains...and breezy to windy conditions at times.
&&
.Discussion...
First wave of precip in Norcal has virtually moved south of our CWA
as vort max off the central CA coast drops SEwd to off the Socal
coast by 00z Fri. Updated the zones earlier this morning to account
for a weaker short wave and area of showers expected to move through
the Nrn portion of the CWA this afternoon...mainly affecting the
coastal mtns and Nrn zones including the Nrn Sac Vly. This feature
is between the 2 larger scale waves...the one to our SW and the
other rotating around the Rex low over the Pac NW.
This system will wind down tonite and there will be a break in the
wx. Then on Fri and into the weekend the much wetter and warmer wx
system will impact Norcal. The main TPW plume around 150-160W will
advect NEwd as energy rotates around the base of the central Pac
trof and the Pacific jet moves into Norcal. WAA precip will rapidly
develop over Norcal on Fri with The amplification of the ridge and
jet shifting the plume gradually Nwd on Sat. With the influx of
subtropical air...snow levels will rise so the initial warning for
the Siernev around 5 kft will need to be tweaked to higher snow
levels during the weekend. Snow levels could rise to near or above
the major passes on I-80/Hwy 50 during the late Sat early Sun time
frame. In advance of this...the main impact will be Fri afternoon
and Fri nite with the lower snow levels and focus of the plume over
the 80/50 corridor. Thus...we are contemplating upgrading the watch
to a warning by the afternoon package. A gradual drop in snow levels
to below pass level is likely on Sun as the jet sags Swd again. Main
changes to forecasts will be to QPF and snow levels...and we are
also contemplating winds Fri afternoon into Sat morning in the
valley as Sly upvalley flow increases in the warm sector.
JHM
Satellite imagery showing short wave trough rotating around large
scale polar low and across the CWA this morning with light to
moderate returns on Mosaic base reflectivity. Rainfall amounts
generally around around a third of an inch or less in the
Sacramento Valley overnight with lighter amounts to the north.
Light snow has been observed in the Shasta mountains and Coastal
range and in the Sierra Nevada. Snow levels currently around 2000
to 3000 feet. System on satellite appears to be moving faster than
06z progs are showing and latest HRRR suggesting precip will be
decreasing by late morning into early afternoon with lingering
showers...mainly over southern portions of the forecast area where
dynamics and moisture are better focused.
Light shower threat looks to continue tonight...mainly over the
mountains...then large atmospheric river extending from the
tropics takes aim on NorCal. WAA precip and large scale
isentropic lift increases over western portions of the CWA Friday
morning then spreads over the entire CWA during the day. Models
indicating periods of moderate to heavy precip Friday night
through the weekend as the concentrated moisture plume slowly sags
southward through Interior NorCal. Low snow levels in the
foothills will continue Friday morning but will gradually
rise to above 6000 feet by Saturday evening and near pass levels
Sunday into Monday. Winter storm watch has been expanded to
include the Coastal mountains for Friday into Saturday. Models
continue to showing significantly different QPF totals through the
weekend with oper GFS indicating upwards of 6 to 7 inches of
liquid precip in the Sierra while the ECMWF-HiRes is a little less
than half that amount. QPFs are in better agreement in the Central
Valley where upwards of 1 to 3 inches likely.
PCH
.Extended Discussion (Monday through Thursday)
Precipitation tapers off on Monday as temporary upper ridging
slides over the west coast. ECMWF a little slower clearing out
last in series of weekend systems so left in slight threat pops on
Monday with highest pops over Sierra closest to departing system.
Extended models all flatten west coast ridge quickly next Tuesday
as next Pacific frontal system pushes into the Pacific Northwest
bringing slight chances of precipitation to the northern most
portions of the state. Relatively flat ridging over the west coast
will allow a couple more slightly stronger Pacific systems to move
into the region Wednesday and Thursday. Precipitation amounts
will be limited due to general ridging over the area but most of
CWA will see a threat of precipitation. Despite cloud cover and
occasional precipitation...Daytime highs throughout the extended
period are expected to remain several degrees above normal with
moderate to high snow levels under moderately warm airmass.
&&
.Aviation...
Frontal system has shifted into central California with scattered
showers expected to continue across NorCal through this afternoon.
Primarily VFR/MVFR, but local IFR ceilings possible in heavier
showers. Generally IFR/LIFR conditions for mountains the next 24
hours, with snow levels down to 2500 to 3500 ft. Mainly south winds
10 to 15 knots for the lower elevations, with southwest wind gusts
to 40 knots over higher terrain. Shen
&&
.STO Watches/Warnings/Advisories...
Winter Storm Watch from Friday afternoon through Saturday evening
above 5000 feet in the west slope Northern Sierra Nevada...Western
Plumas county/Lassen park.
Winter Weather Advisory until 10 pm pst this evening above 4000
feet in the west slope Northern Sierra Nevada.
Winter Storm Watch from Friday afternoon through Saturday
afternoon above 4000 feet in the mountains southwestern Shasta
county to northern Lake county.
Winter Storm Watch from Friday afternoon through Saturday evening
for Shasta Lake area/Western Shasta county.
&&
$$
AREA FORECAST DISCUSSION
NWS MIAMI FL
246 PM EST THU FEB 6 2014
.DISCUSSION...
STALLED FRONTAL BOUNDARY REMAINED DRAPED ACROSS THE LAKE REGION
EARLY THIS AFTERNOON. A FEW SHOWERS WERE ALSO BEGINNING TO DEVELOP
ALONG THE BOUNDARY. SCATTERED SHOWERS AND A FEW THUNDERSTORMS
REMAIN IN THE FORECAST THROUGH THE AFTERNOON HOURS. A FEW SHOWERS
COULD LINGER INTO THE OVERNIGHT HOURS ACROSS THE INTERIOR AND PALM
BEACH COUNTY.
LOW CEILINGS AND FOG IS EXPECTED AGAIN TONIGHT. SREF IS SHOWING
NEAR 100 PERCENT PROBABILITY OF CEILINGS BELOW 1000FT FROM SOUTH
OF NAPLES AND ACROSS GLADES AND HENDRY COUNTIES. DENSE SEA FOG IS
POSSIBLE AGAIN THIS EVENING OVER THE GULF WATERS...THEN AFTER
MIDNIGHT WINDS ARE EXPECTED TO INCREASE OUT OF THE NORTHEAST AND
THAT SHOULD PUT AN END TO THE FOG THERE. SOME GUIDANCE SUGGESTS
THAT FOG COULD DEVELOP ACROSS THE INTERIOR AND THEN PUSH INTO THE
METRO AREAS LATE TONIGHT AS THE BOUNDARY LAYER WINDS SHIFT TO THE
WEST. SO PUSHED THE PATCHY FOG CHANCE TO THE COAST AND AREAS OF
FOG INTO THE METRO AREAS FOR TONIGHT. DENSE FOG IS ALSO POSSIBLE.
THE FRONTAL BOUNDARY IS FORECAST TO LIFT SLOWLY BACK NORTHWARD ON
FRIDAY AS A WARM FRONT. SOME SLIGHT DRYING IS FORECAST TO TAKE
PLACE IN THE LOW LEVELS ON FRIDAY...BEFORE DEEPER MOISTURE SURGES
BACK INTO THE REGION FRIDAY NIGHT INTO SATURDAY.
AN AREA OF LOW PRESSURE IS FORECAST TO DEVELOP ALONG THE FRONTAL
BOUNDARY OFF OF THE EAST CENTRAL FLORIDA COAST FRIDAY NIGHT INTO
SATURDAY. THIS LOW WILL THEN MOVE OFF TO THE NORTHEAST THROUGH THE
WEEKEND. THIS WILL FORCE THE FRONTAL BOUNDARY BACK SOUTH...AND
INCREASE RAIN CHANCES ON SATURDAY AND INTO SUNDAY. THE FRONT IS
THEN FORECAST TO PUSH SOUTH OF THE REGION BY SUNDAY EVENING...WITH
DRIER AIR PUSHING INTO SOUTH FLORIDA. IT WILL BE WARM THIS WEEKEND
WITH HIGHS IN THE 80S AND HEAT INDICES NEARING 90.
HIGH TEMPERATURES WILL NOT BE AFFECTED EARLY NEXT WEEK BY THE
FRONTAL PASSAGE...BUT DEWPOINTS WILL DROP 5-10 DEGREES AND
OVERNIGHT LOWS WILL BE SEVERAL DEGREES COOLER. THE DRY AND
COMFORTABLE WEATHER WILL NOT LAST LONG. ANOTHER AREA OF LOW
PRESSURE WILL DEVELOP OVER THE NORTHWESTERN GULF OF MEXICO AND
MOVE NORTHEAST ACROSS THE SOUTHEASTERN UNITED STATES BY THE MIDDLE
OF NEXT WEEK. IN TURN...MOISTURE WILL THEN INCREASE AGAIN FROM THE
SOUTH.
&&
.AVIATION...
A COLD FRONT STALLED ACROSS THE AREA WILL CONTINUE TO INFLUENCE
THE LOCAL WEATHER THROUGH THE 24 HR TAF PERIOD...MAINLY FOR
REDUCED CIGS AND VSBYS AT SITE APF AND INCREASED SHOWER/TSTM
CHANCES AROUND PBI. THE LATEST HRRR AND WRF MODEL REFLECTIVITIES
INDICATE THE BEST RAIN CHANCES SETTING UP ACROSS THE INTERIOR AND
NORTHERN LOCATIONS FROM THE LAKE TO THE PALM BEACHES THROUGH THE
AFTERNOON HOURS TODAY. ALTHOUGH THE BULK OF THIS ACTIVITY SHOULD
REMAIN JUST INLAND OF THE PBI SITE...ANY EWD SHIFT TOWARD THE
COAST THROUGH THE LATE AFTERNOON/EARLY EVENING HOURS COULD RESULT
IN REDUCED VSBYS/CIGS IN AND AROUND ANY ACTIVITY. SIMILAR TO THIS
MORNING AND THROUGH THE OVERNIGHT HOURS LAST NIGHT...CIGS/VSBYS
DUE FOG WILL BECOME THE MAIN CONCERN...MAINLY FOR SITE APF AND
POSSIBLY TMB. THIS MAY LINGER THROUGH THE MID-MORNING HOURS FRIDAY
BEFORE BURNING OFF OR LIFTING. 85/AG
&&
.MARINE...
THE WINDS WILL REMAIN BELOW 10 KNOTS THROUGH THIS WEEKEND...EXCEPT
OVER THE GULF WATERS TONIGHT WHERE WINDS WILL INCREASE TO 10-15
KNOTS. THIS WILL KEEP THE SEAS 4 FEET OR LESS THROUGH THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 67 80 68 83 / 20 10 10 30
FORT LAUDERDALE 69 78 72 80 / 10 10 10 30
MIAMI 69 80 71 83 / 10 10 10 30
NAPLES 67 81 66 81 / 20 10 10 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...84/AK
AVIATION/RADAR...85/AG
AREA FORECAST DISCUSSION
NWS MIAMI FL
113 PM EST THU FEB 6 2014
.AVIATION...
A COLD FRONT STALLED ACROSS THE AREA WILL CONTINUE TO INFLUENCE
THE LOCAL WEATHER THROUGH THE 24 HR TAF PERIOD...MAINLY FOR
REDUCED CIGS AND VSBYS AT SITE APF AND INCREASED SHOWER/TSTM
CHANCES AROUND PBI. THE LATEST HRRR AND WRF MODEL REFLECTIVITIES
INDICATE THE BEST RAIN CHANCES SETTING UP ACROSS THE INTERIOR AND
NORTHERN LOCATIONS FROM THE LAKE TO THE PALM BEACHES THROUGH THE
AFTERNOON HOURS TODAY. ALTHOUGH THE BULK OF THIS ACTIVITY SHOULD
REMAIN JUST INLAND OF THE PBI SITE...ANY EWD SHIFT TOWARD THE
COAST THROUGH THE LATE AFTERNOON/EARLY EVENING HOURS COULD RESULT
IN REDUCED VSBYS/CIGS IN AND AROUND ANY ACTIVITY. SIMILAR TO THIS
MORNING AND THROUGH THE OVERNIGHT HOURS LAST NIGHT...CIGS/VSBYS
DUE FOG WILL BECOME THE MAIN CONCERN...MAINLY FOR SITE APF AND
POSSIBLY TMB. THIS MAY LINGER THROUGH THE MID-MORNING HOURS FRIDAY
BEFORE BURNING OFF OR LIFTING. 85/AG
&&
.PREV DISCUSSION... /ISSUED 920 AM EST THU FEB 6 2014/
UPDATE...
A STALLED FRONTAL BOUNDARY WAS LOCATED FROM NEAR FORT MYERS
NORTHEASTWARD THROUGH VERO BEACH THIS MORNING. DENSE FOG FORMED
SOUTH OF THIS BOUNDARY...WITH VISIBILITIES 1/4 MILE OR LESS ACROSS
MUCH OF THE WESTERN INTERIOR. THE FOG IS BEGINNING TO LIFT AND THE
DENSE FOG ADVISORY WAS ALLOWED TO EXPIRE FOR THE LAND AND WATER
AREAS AT 9 AM. DENSE FOG DEVELOPED OVER THE LOCAL GULF WATERS
WEST OF NAPLES LAST NIGHT. BEACH CAMS SHOW SOME FOG STILL
REMAINS...SO WILL KEEP PATCHY FOG IN THE FORECAST FOR THE GULF
WATERS THROUGHOUT THE DAY. DENSE FOG COULD REDEVELOP OVER THE
WATER THIS EVENING.
THE SURFACE BOUNDARY IS FORECAST TO REMAIN NEARLY STATIONARY
TODAY...AND SHOWERS AND A FEW THUNDERSTORMS ARE FORECAST TO
DEVELOP ALONG AND SOUTH OF THIS BOUNDARY. THE BEST CHANCE OF
SHOWERS AND STORMS IS ACROSS THE INTERIOR THIS AFTERNOON...WITH
SOME SHOWERS POSSIBLY MOVING INTO THE METRO AREAS OF PALM BEACH
AND BROWARD COUNTIES AS WELL. THE GLOBAL MODELS AS WELL AS THE
LOCAL WRF MODELS AND HRRR ARE ALL IN GOOD AGREEMENT ON THIS
SCENARIO THIS AFTERNOON.
PREV DISCUSSION... /ISSUED 628 AM EST THU FEB 6 2014/
AVIATION...
KAPF WILL SLOWLY COME OUT OF THE IFR CONDITIONS BY 14Z THIS
MORNING DUE TO THE FOG BURNING OFF. REST OF THE TAF SITES WILL BE
IN THE VFR CONDITIONS TODAY. SHOWERS/TSTORMS LOOK TO FOCUS OVER
THE INTERIOR THIS AFTERNOON. KPBI STANDS THE BETTER CHANCE OF A
FEW SHRA/TSRA MOVING IN FROM THE WEST LATE THIS AFTERNOON SO
INCLUDED VCTS THERE. BNB
PREV DISCUSSION... /ISSUED 310 AM EST THU FEB 6 2014/
ABOVE NORMAL TEMPERATURES CONTINUE THROUGH THE WEEKEND OVER SOUTH FLORIDA...
PATCHY TO AREAS OF FOG EACH NIGHT THROUGH THE WEEKEND...
SHORT TERM...
FOG HAS DEVELOPED EARLY THIS MORNING OVER THE WESTERN AREAS OF
SOUTH FLORIDA WITH ISOLATED AREAS OF DENSE FOG. THE FOG SHOULD
CONTINUE OVER THE WESTERN AREAS THROUGH SUNRISE WHILE SPREADING
INTO THE EASTERN INTERIOR AREAS OF SOUTH FLORIDA. SO A DENSE FOG
ADVISORY HAS BEEN ISSUED FOR THE WESTERN AREAS OF SOUTH FLORIDA
THROUGH 9 AM EDT THIS MORNING...AND WE WILL CONTINUE TO MONITOR
THE EASTERN INTERIOR AREAS OF SOUTH FLORIDA THROUGH THE EARLY
MORNING HOURS TO SEE IF THE DENSE FOG ADVISORY NEEDS TO BE
EXPANDED EASTWARD.
A COLD FRONT OVER CENTRAL FLORIDA WILL CONTINUE TO MOVE SLOWLY
SOUTH TODAY...BEFORE STALLING OVER THE LAKE OKEECHOBEE REGION
TONIGHT. THIS WILL KEEP THE WIND FLOW OVER SOUTH FLORIDA IN A
SOUTHERLY DIRECTION TODAY ALONG WITH THE EAST AND WEST COAST SEA
BREEZES DEVELOPING AND PUSHING INLAND. SO THE BEST COVERAGE OF
SHOWERS WILL BE OVER THE INTERIOR AREAS TODAY ALONG WITH A FEW
STORMS LATE THIS AFTERNOON. THERE COULD ALSO BE A FEW STORMS OVER
METRO PALM BEACH COUNTY LATE THIS AFTERNOON INTO EARLY THIS
EVENING...AS THE STEERING FLOW WILL BECOME MORE SOUTHWEST AHEAD OF
THE FRONT.
FOG IS AGAIN POSSIBLE TONIGHT OVER MOST OF SOUTH FLORIDA WITH EVEN
SOME DENSE FOG POSSIBLE OVER THE INTERIOR AND WEST COAST METRO
AREAS...DUE TO THE FRONT NEARBY AND THE LIGHT SOUTH TO SOUTHWEST
STEERING FLOW. SO HAVE PUT IN FOG WORDING OVER MOST OF SOUTH FLORIDA
FOR LATE TONIGHT INTO EARLY FRIDAY MORNING WITH EVEN ISOLATED DENSE
FOG OVER THE INTERIOR AND WEST COAST METRO AREAS.
THE STATIONARY FRONT OVER LAKE OKEECHOBEE REGION WILL MOVE BACK
NORTHWARD INTO NORTHERN FLORIDA ON FRIDAY...AS A WEAK LOW
PRESSURE DEVELOPS OVER THE NORTHERN GULF OF MEXICO. THIS WILL
ALLOW FOR THE STEERING FLOW TO BE SOUTHEAST OVER SOUTH FLORIDA ON
FRIDAY BRINGING IN SOME DRIER AIR TO THE AREA FROM THE BAHAMA
ISLANDS. SO THE ONLY AREA THAT WILL SEE A SLIGHT CHANCE OF SHOWERS
WILL BE OVER THE INTERIOR AND WEST COAST METRO AREAS ON FRIDAY.
THE WEAK LOW WILL MOVE NORTHEAST ACROSS NORTHERN FLORIDA ON
SATURDAY BEFORE MOVING INTO THE WESTERN ATLANTIC WATERS ON SUNDAY.
THIS WILL ALLOW FOR THE WARM FRONT TO BECOME A COLD FRONT AND MOVE
SOUTH THROUGH SOUTH FLORIDA ON SUNDAY. SO THE SLIGHT CHANCE OF
SHOWERS WILL CONTINUE OVER SOUTH FLORIDA THIS WEEKEND...EXCEPT FOR
A CHANCE OF SHOWERS AROUND THE LAKE OKEECHOBEE REGION ON SATURDAY.
HIGHS THROUGH THIS WEEKEND WILL BE IN THE LOWER TO MID 80S WITH
LOWS IN THE 60S...EXCEPT AROUND 70 ALONG THE EAST COAST METRO
AREAS. THESE HIGHS AND LOWS ARE ABOUT 5 TO 10 DEGREES ABOVE THE
AVERAGE FOR THIS TIME OF YEAR. THE HEAT INDEX WILL ALSO BE RUNNING
IN THE MID 80S TO AROUND 90 DEGREES THIS WEEKEND.
LONG TERM...
DRY AND MORE COMFORTABLE WEATHER WILL RETURN TO SOUTH FLORIDA EARLY
NEXT WEEK BEHIND THE PASSAGE OF THE COLD FRONT LATE THIS WEEKEND.
HOWEVER...THE DRY AND COMFORTABLE WEATHER WILL NOT LAST LONG AS
ANOTHER LOW PRESSURE WILL DEVELOP OVER THE NORTHWEST GULF OF
MEXICO AND MOVE NORTHEAST ACROSS THE SOUTHEASTERN UNITED STATES BY
MIDDLE OF NEXT WEEK. THIS IN TURN WILL BRING THE WINDS BACK TO A
SOUTHERLY DIRECTION AND BRING IN THE MOISTURE FROM THE SOUTH BY THE
MIDDLE OF NEXT WEEK. THERE WILL ALSO BE A 20 TO 30 PERCENT CHANCE OF
SHOWERS OVER THE AREA MIDDLE OF NEXT WEEK.
AVIATION...
KAPF JUST WENT DOWN TO 1/4SM FG AND LOOKS AS THOUGH
THIS MAY HANG IN ALL NIGHT SO KEPT THIS CONDITION GOING. ELSEWHERE
THE THINKING IS THAT LOW CLOUDINESS WILL DEVELOP IN MVFR CATEGORY.
WILL HAVE TO KEEP AN EYE OUT FOR POSSIBLE IFR AS WELL, BUT GIVEN
UNCERTAINTIES MAINTAINED MVFR EAST COAST SITES. POSSIBLE
IMPROVEMENT DURING THE DAY, BUT MVFR COULD HANG ON THROUGHOUT THE
DAY...ESPECIALLY AT KAPF. SHOWERS/TSTORMS LOOK TO FOCUS OVER THE
INTERIOR THIS AFTERNOON. KPBI STANDS THE BETTER CHANCE OF A FEW
SHRA/TSRA MOVING IN FROM THE WEST LATE THIS AFTERNOON SO INCLUDED
VCTS THERE. /GREGORIA
MARINE...
THE WINDS WILL REMAIN BELOW 10 KNOTS TODAY INTO THIS WEEKEND WHILE
SLOWLY REMAINING IN A SOUTHERLY DIRECTION. THIS WILL KEEP THE SEAS
BELOW 6 FEET TODAY INTO THIS WEEKEND IN BOTH THE ATLANTIC AND GULF
WATERS. SO BOATING CONDITIONS SHOULD BE GOOD THIS WEEKEND OUTSIDE
OF ANY SHOWERS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 67 82 68 83 / 30 10 10 20
FORT LAUDERDALE 70 83 72 83 / 20 10 10 20
MIAMI 71 84 71 84 / 20 10 10 20
NAPLES 63 82 64 81 / 20 20 10 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...57/DG
AVIATION/RADAR...54/BNB
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
226 PM CST THU FEB 6 2014
.DISCUSSION...
952 AM CST
WE WILL BE LETTING THE WIND CHILL ADVISORY FOR THIS MORNING EXPIRE
AT 10 AM. SEVERAL SITES OUT WEST ARE STILL HOVERING RIGHT AROUND
-20 FOR THE WIND CHILL...BUT THESE AREAS SHOULD IMPROVE SOME INTO
NEXT HOUR OR TWO...AND WE FELT THAT IT WAS NOT WORTH EXTENDING THE
ADVISORY FOR ANOTHER HOUR OR TWO. OTHERWISE...NO MAJOR CHANGES TO
THE GOING FORECAST. WE WILL ASSES THE NEED TO EXPAND THE WIND
CHILL ADVISORY FOR TONIGHT INTO FRIDAY ACROSS THE REST OF THE AREA
WITH THE AFTERNOON PACKAGE.
KJB
//PREV DISCUSSION...
333 AM CST
THIS FORECAST WAS FOCUSED ON CURRENT COLD AIR THROUGH FRIDAY AS
WELL AS THE NEXT ROUND EARLY NEXT WEEK...WITH A SNOW EVENT
SANDWICHED IN-BETWEEN ON SATURDAY. THERE SURE HAVE BEEN PLENTY OF
THESE COLD-SNOW-COLD SANDWICHES THIS WINTER!
TODAY...
FROM A MASSIVE STORM SYSTEM YESTERDAY MORNING TO A MASSIVE HIGH
PRESSURE THIS MORNING...THE PROGRESSIVE FLOW CONTINUES. THIS
MORNINGS HIGH CENTERED AT 1043MB FROM MT INTO THE CENTRAL PLAINS
IS TRYING TO NUDGE ITS WAY INTO THE AREA. AT THE LEADING EDGE OF
THE 850-925MB THERMAL TROUGH THERE HAVE BEEN UNDULATING POCKETS OF
STRATOCU WITH FLURRIES EARLY THIS MORNING OVER THE FORECAST AREA.
THE RAP ANALYZES THIS WELL AND PROPAGATES THIS CAA/RH EAST OF
THE AREA BY MID-MORNING. COULD BE SOME FEW-SCT FINGERS OF CU TO
REDEVELOP TODAY AS COLD AIR ADVECTION AT THE TOP OF THE MIXED LAYER
CONTINUES THROUGH EARLY AFTERNOON. THIS ALSO COULD BE REALIZED AT
THE SFC WITH TEMPS STEADY OR EVEN SLOWLY DROPPING THROUGH 9-10 AM
IN SOME COMMUNITIES. THE REBOUND WILL BE SMALL TODAY WITH HIGHS
IN THE 5 TO THE 10 ABOVE RANGE...WITH MAYBE 12-14 IN DOWNTOWN
CHICAGO. THOSE ARE A COUPLE-FEW DEGREES HIGHER THAN INHERITED AND
THIS CLIMB WAS BECAUSE THESE EARLY MORNING CLOUDS THAT HAVE KEPT
SOME READINGS UP.
TONIGHT/FRIDAY...
THE HIGH PRESSURE WILL EXPAND EAST INTO THE MID-MISSISSIPPI
VALLEY BY LATE THIS EVE AND WEAKEN SLOWLY AS IT DOES. WE SHOULD
MAINTAIN SOME WIND COMPONENT...ALTHOUGH SUSPECT THAT GUIDANCE MAY
BE TOO HIGH ON WIND SPEEDS AS THEY OFTEN CAN BE AT NIGHT AND OVER
SNOW COVER. EVEN WITH 5-8 KT WINDS...WIND CHILL ADVISORY CRITERIA
LOOKS TO BE REACHED IN A GOOD PART OF THE AREA THAT IS UNDER THE
CURRENT WIND CHILL ADVISORY. AS FOR ACROSS THE SOUTHERN FORECAST
AREA...WHICH IS CLOSEST TO THE ACTIVE JET ACROSS THE SOUTHERN
U.S...THERE WILL LIKELY BE AT LEAST SOME THIN CIRRUS...IF NOT
BROKEN. SO A BIT MORE MARGINAL THERE. HAVE GONE WITH A WIND CHILL
ADVISORY FOR TONIGHT/FRIDAY IN THE CURRENT ADVISORY AREA TO GET
THE MESSAGE OUT. WILL LET DAY SHIFT ASSESS IF IT NEEDS TO BE
EXPANDED EAST...INCLUDING INTO THE CHICAGO METRO AREA. SOUTHWEST
FLOW GRADUALLY STARTS TO ENVELOP THE AREA FRIDAY BEHIND THE
HIGH...SO A HANDFUL OF DEGREES ARE EXPECTED TO BE ADDED TO TODAYS
HIGHS...WITH 10 TO 15 FORECAST ON FRIDAY.
SATURDAY/SATURDAY NIGHT...
GOOD AGREEMENT IN GUIDANCE ON MASS FIELDS REMAINS THE CASE THROUGH
THE FIRST HALF OF THE WEEKEND...WITH A STRONG WESTERLY UPPER JET
MOVING OVER THE WEST COAST AND ADVANCING EAST INTO THE CENTRAL
PLAINS. A QUICK-MOVING SORT OF HYBRID PACIFIC/CLIPPER SYSTEM IS
EXPECTED TO PROGRESS WITH THE LEFT EXIT REGION OF THIS INTO THE
AREA. DIFFERENCES DO EXIST IN GUIDANCE IN HOW IT EVOLVES THE LOW-
LEVEL FEATURES...WITH THE 00Z/06Z NAM BEING 10MB DEEPER THAN THE
00Z EC ON THE SURFACE WAVE...AND ACTUALLY THE ONLY MODEL SHOWING A
DEEPENING TREND IN THE SFC WAVE AS IT MOVES EAST OVER THE FORECAST
AREA. WHILE THE NAM CAN BE A BIT ROBUST ON DAY 3 IT SEEMS...THE
PV ANOMALY ASSOCIATED WITH THE UPPER TROUGH IS QUITE STRONG AND
ITS ORIENTATION WOULD FAVOR A LOW TO AT LEAST HOLD ITS INTENSITY
AS IT MOVES OVER THE AREA. SO AGAIN LEAN WITH THE MIDDLE GROUND
00Z GFS...WHICH ALSO HAS A MIDDLE GROUND QPF FORECAST.
THE IMPRESSIVE FEATURE WITH THIS IS THE MID-LEVEL VORT MAGNITUDE
AND ITS ADVECTION...DIRECTLY OVER AT LEAST PART OF THE FORECAST AREA
ON GUIDANCE...AND IT TIGHTENS THE BAROCLINIC ZONE TO WHERE IT
WOULD SEEM TEMPORARY BANDING COULD BE A CONCERN. THE GFS ALSO WOULD
SUGGEST THE DENDRITIC GROWTH ZONE IS LIKELY TO BE TAPPED AND GIVEN
A LIMITED RETURN FLOW PERIOD...WOULD EXPECT THE COLUMN TO BE COOL
ENOUGH TO PRESENT THIS AS A POSSIBLE CONCERN. SO HAVE GONE TOWARD
15:1 RATIOS IN INITIAL SNOW FORECAST. VORT MAGNITUDE USING
EMPIRICAL LEMO TECHNIQUE WOULD SUPPORT AT LEAST A FEW INCH STRIPE
OF SNOW SOMEWHERE...BUT WE WILL HAVE TO SEE AS WE GET CLOSER...AS
DURATION OF SNOW COULD OVERALL BE LIMITED IF EARLY SATURATION IS
AN ISSUE. WHILE CONTINUED THE TREND TO INCH UP POPS...NOW WITH 70
PERCENTS ACROSS MUCH OF NORTHERN IL ON SATURDAY. DID NOT GET FANCY
TRYING TO BREAK OUT MORNING VS AFTERNOON...BUT SOME TEMPORAL
RESOLUTION WILL INEVITABLY BE ABLE TO BE ADDED IN TIME.
SUNDAY AND BEYOND...
NORTHWEST FLOW ALOFT REMAINS FORECAST DURING EARLY NEXT
WEEK...WITH COLD AIR ADVECTION DEVELOPING BEHIND THE SATURDAY
SYSTEM. SUNDAY NIGHT/MONDAY MORNING COULD VERY WELL BE A PERIOD OF
WIND CHILL CONCERNS AGAIN. THE 925MB TEMPERATURES IN THE -15C TO
-20C RANGE ONCE AGAIN COULD SUPPORT NEGATIVE DOUBLE DIGIT LOWS IN
MOST OUTLYING AREAS ON MONDAY NIGHT WHERE LONG RANGE GUIDANCE
INDICATES HIGH PRESSURE AND A CLEAR SKY OVER THE FRESHENED SNOW
PACK. HAVE LEANED TOWARD A RAW BLEND OF GUIDANCE /NO MOS/ IN THAT
PERIOD...AND EVEN UNDERCUT THAT BY A FEW DEGREES. WITH THE HIGH
PRESSURE AND DEGREE OF SUBSIDENCE MOVING OVERHEAD IT LOOKS LIKE A
POSSIBLE MINI-PERIOD OF DRY WEATHER /OUTSIDE OF FLURRIES/ DURING
SUN THROUGH TUE...AT LEAST AT THIS TIME.
MTF
&&
.CLIMATE...
RECORD COLD HIGHS FOR TODAY FEBRUARY 6TH:
ROCKFORD: 3 DEGREES (1982)
WHILE THIS IS NOT LIKELY TO BE BROKEN TODAY...THE TEMPERATURE AT
MIDNIGHT WAS 2 DEGREES AND IT COULD BE CLOSE THIS AFTERNOON.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* NONE.
KREIN
//DISCUSSION...UPDATED 18Z...
QUIET WEATHER FOR THE AVIATION COMUNITY WILL CONTINUE THROUGH THE
PERIOD. WITH HIGH PRESSURE BUILDING ACTOSS THE MIDDLE MISSISSIPPI
VALLEY THROUGH THE OHIO VALLEY...SKIES ARE MOSTLY CLEAR WITH ONLY
A FEW FRAGMENTS OF STRATOCU OR CIRRUS. WINDS WILL BE OUT OF THE
WEST THROUGH THE REMAINDER OF THE DAY BEFORE GRADUALLY BACKING A
LITTLE MORE SWLY THROUGH THE EVENING AND OVERNIGHT. AMPLE SUNSHINE
WILL ALLOW FOR SOME MIXING THROUGH THE DAYTIME HOURS...SO...WILL
MAINTAIN THE GUSTS IN THE UPPER TEENS. SOME MID LEVEL MOISTURE IS
EXPECTION TO OVERSPREAD THE REGION TONIGHT...BRINGING SOME SCT-BKN
WITH BASES AT 8KFT-10KFT...BUT NOTHING OPERATIONALLY SIGNIFICANT.
CONDITIONS TOMORROW WILL CONTINUE TO BE QUIET...WITH SWLY WINDS
AND MOSTLY CLEAR SKIES.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN ALL FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...VFR.
SATURDAY...SNOW LIKELY WITH SOME ACCUMULATION. IFR PSBL.
SUNDAY THROUGH WEDNESDAY...VFR LIKELY.
BMD
&&
.MARINE...
224 PM CST
BROAD SURFACE RIDGE EXTENDS FROM THE OHIO VALLEY WEST THROUGH THE
CENTRAL PLAINS...AND WILL REMAIN ORIENTED ACROSS THIS AREA THROUGH
THE NEXT 24 HOURS. THIS FEATURE COMBINED WITH A LOW PRESSURE WELL
NORTH ACROSS HUDSON BAY WILL CREATE A WESTERLY GRADIENT ACROSS THE
LAKE AND PRODUCE WINDS TO 30 KT OVERNIGHT THROUGH FRIDAY BEFORE THIS
GRADIENT WEAKENS. AS A RESULT OF THE INCREASED WINDS TONIGHT THROUGH
FRIDAY OVER THE NORTHERN PORTIONS OF THE LAKE...FREEZING SPRAY IS
LIKELY FOR THE ICE FREE AREAS. FOR THE NEARSHORE WATERS THE WINDS
HAVE BEEN HOVERING AROUND SMALL CRAFT CONDITIONS...HOWEVER IT
APPEARS THE WINDS WILL DIMINISH SLIGHTLY THIS EVENING TO COME BACK
DOWN TO 15 TO 25 KT. SO WILL NOT BE ISSUING ANY HEADLINES AT THIS
TIME. THE RIDGE WILL BEGIN TO DRIFT EAST TOWARDS NEW ENGLAND
SATURDAY...WHILE A TROUGH OF LOW PRESSURE BEGINS TO PULL EAST OF
THE CENTRAL ROCKIES SATURDAY MORNING. THIS LOW IS THEN EXPECTED TO
LIFT NORTHEAST TOWARDS THE WESTERN GREAT LAKES SATURDAY AFTERNOON.
THIS LOW WILL THEN LIFT NORTHEAST TO THE EASTERN LAKES MIDDAY
SUNDAY AND ALLOW A TIGHTENING GRADIENT AND NORTHWEST FLOW TO
RETURN FOR LAKE MICHIGAN.
ANOTHER RIDGE OF HIGH PRESSURE WILL RETURN EARLY NEXT WEEK FOR THE
GREAT LAKES...WITH LIGHT FLOW RETURNING AS WELL.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WIND CHILL ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032-ILZ033-ILZ039...6 PM THURSDAY TO 11 AM FRIDAY.
IN...WIND CHILL ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019...6 PM
THURSDAY TO 11 AM FRIDAY.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
137 PM CST THU FEB 6 2014
.DISCUSSION...
952 AM CST
WE WILL BE LETTING THE WIND CHILL ADVISORY FOR THIS MORNING EXPIRE
AT 10 AM. SEVERAL SITES OUT WEST ARE STILL HOVERING RIGHT AROUND
-20 FOR THE WIND CHILL...BUT THESE AREAS SHOULD IMPROVE SOME INTO
NEXT HOUR OR TWO...AND WE FELT THAT IT WAS NOT WORTH EXTENDING THE
ADVISORY FOR ANOTHER HOUR OR TWO. OTHERWISE...NO MAJOR CHANGES TO
THE GOING FORECAST. WE WILL ASSES THE NEED TO EXPAND THE WIND
CHILL ADVISORY FOR TONIGHT INTO FRIDAY ACROSS THE REST OF THE AREA
WITH THE AFTERNOON PACKAGE.
KJB
//PREV DISCUSSION...
333 AM CST
THIS FORECAST WAS FOCUSED ON CURRENT COLD AIR THROUGH FRIDAY AS
WELL AS THE NEXT ROUND EARLY NEXT WEEK...WITH A SNOW EVENT
SANDWICHED IN-BETWEEN ON SATURDAY. THERE SURE HAVE BEEN PLENTY OF
THESE COLD-SNOW-COLD SANDWICHES THIS WINTER!
TODAY...
FROM A MASSIVE STORM SYSTEM YESTERDAY MORNING TO A MASSIVE HIGH
PRESSURE THIS MORNING...THE PROGRESSIVE FLOW CONTINUES. THIS
MORNINGS HIGH CENTERED AT 1043MB FROM MT INTO THE CENTRAL PLAINS
IS TRYING TO NUDGE ITS WAY INTO THE AREA. AT THE LEADING EDGE OF
THE 850-925MB THERMAL TROUGH THERE HAVE BEEN UNDULATING POCKETS OF
STRATOCU WITH FLURRIES EARLY THIS MORNING OVER THE FORECAST AREA.
THE RAP ANALYZES THIS WELL AND PROPAGATES THIS CAA/RH EAST OF
THE AREA BY MID-MORNING. COULD BE SOME FEW-SCT FINGERS OF CU TO
REDEVELOP TODAY AS COLD AIR ADVECTION AT THE TOP OF THE MIXED LAYER
CONTINUES THROUGH EARLY AFTERNOON. THIS ALSO COULD BE REALIZED AT
THE SFC WITH TEMPS STEADY OR EVEN SLOWLY DROPPING THROUGH 9-10 AM
IN SOME COMMUNITIES. THE REBOUND WILL BE SMALL TODAY WITH HIGHS
IN THE 5 TO THE 10 ABOVE RANGE...WITH MAYBE 12-14 IN DOWNTOWN
CHICAGO. THOSE ARE A COUPLE-FEW DEGREES HIGHER THAN INHERITED AND
THIS CLIMB WAS BECAUSE THESE EARLY MORNING CLOUDS THAT HAVE KEPT
SOME READINGS UP.
TONIGHT/FRIDAY...
THE HIGH PRESSURE WILL EXPAND EAST INTO THE MID-MISSISSIPPI
VALLEY BY LATE THIS EVE AND WEAKEN SLOWLY AS IT DOES. WE SHOULD
MAINTAIN SOME WIND COMPONENT...ALTHOUGH SUSPECT THAT GUIDANCE MAY
BE TOO HIGH ON WIND SPEEDS AS THEY OFTEN CAN BE AT NIGHT AND OVER
SNOW COVER. EVEN WITH 5-8 KT WINDS...WIND CHILL ADVISORY CRITERIA
LOOKS TO BE REACHED IN A GOOD PART OF THE AREA THAT IS UNDER THE
CURRENT WIND CHILL ADVISORY. AS FOR ACROSS THE SOUTHERN FORECAST
AREA...WHICH IS CLOSEST TO THE ACTIVE JET ACROSS THE SOUTHERN
U.S...THERE WILL LIKELY BE AT LEAST SOME THIN CIRRUS...IF NOT
BROKEN. SO A BIT MORE MARGINAL THERE. HAVE GONE WITH A WIND CHILL
ADVISORY FOR TONIGHT/FRIDAY IN THE CURRENT ADVISORY AREA TO GET
THE MESSAGE OUT. WILL LET DAY SHIFT ASSESS IF IT NEEDS TO BE
EXPANDED EAST...INCLUDING INTO THE CHICAGO METRO AREA. SOUTHWEST
FLOW GRADUALLY STARTS TO ENVELOP THE AREA FRIDAY BEHIND THE
HIGH...SO A HANDFUL OF DEGREES ARE EXPECTED TO BE ADDED TO TODAYS
HIGHS...WITH 10 TO 15 FORECAST ON FRIDAY.
SATURDAY/SATURDAY NIGHT...
GOOD AGREEMENT IN GUIDANCE ON MASS FIELDS REMAINS THE CASE THROUGH
THE FIRST HALF OF THE WEEKEND...WITH A STRONG WESTERLY UPPER JET
MOVING OVER THE WEST COAST AND ADVANCING EAST INTO THE CENTRAL
PLAINS. A QUICK-MOVING SORT OF HYBRID PACIFIC/CLIPPER SYSTEM IS
EXPECTED TO PROGRESS WITH THE LEFT EXIT REGION OF THIS INTO THE
AREA. DIFFERENCES DO EXIST IN GUIDANCE IN HOW IT EVOLVES THE LOW-
LEVEL FEATURES...WITH THE 00Z/06Z NAM BEING 10MB DEEPER THAN THE
00Z EC ON THE SURFACE WAVE...AND ACTUALLY THE ONLY MODEL SHOWING A
DEEPENING TREND IN THE SFC WAVE AS IT MOVES EAST OVER THE FORECAST
AREA. WHILE THE NAM CAN BE A BIT ROBUST ON DAY 3 IT SEEMS...THE
PV ANOMALY ASSOCIATED WITH THE UPPER TROUGH IS QUITE STRONG AND
ITS ORIENTATION WOULD FAVOR A LOW TO AT LEAST HOLD ITS INTENSITY
AS IT MOVES OVER THE AREA. SO AGAIN LEAN WITH THE MIDDLE GROUND
00Z GFS...WHICH ALSO HAS A MIDDLE GROUND QPF FORECAST.
THE IMPRESSIVE FEATURE WITH THIS IS THE MID-LEVEL VORT MAGNITUDE
AND ITS ADVECTION...DIRECTLY OVER AT LEAST PART OF THE FORECAST AREA
ON GUIDANCE...AND IT TIGHTENS THE BAROCLINIC ZONE TO WHERE IT
WOULD SEEM TEMPORARY BANDING COULD BE A CONCERN. THE GFS ALSO WOULD
SUGGEST THE DENDRITIC GROWTH ZONE IS LIKELY TO BE TAPPED AND GIVEN
A LIMITED RETURN FLOW PERIOD...WOULD EXPECT THE COLUMN TO BE COOL
ENOUGH TO PRESENT THIS AS A POSSIBLE CONCERN. SO HAVE GONE TOWARD
15:1 RATIOS IN INITIAL SNOW FORECAST. VORT MAGNITUDE USING
EMPIRICAL LEMO TECHNIQUE WOULD SUPPORT AT LEAST A FEW INCH STRIPE
OF SNOW SOMEWHERE...BUT WE WILL HAVE TO SEE AS WE GET CLOSER...AS
DURATION OF SNOW COULD OVERALL BE LIMITED IF EARLY SATURATION IS
AN ISSUE. WHILE CONTINUED THE TREND TO INCH UP POPS...NOW WITH 70
PERCENTS ACROSS MUCH OF NORTHERN IL ON SATURDAY. DID NOT GET FANCY
TRYING TO BREAK OUT MORNING VS AFTERNOON...BUT SOME TEMPORAL
RESOLUTION WILL INEVITABLY BE ABLE TO BE ADDED IN TIME.
SUNDAY AND BEYOND...
NORTHWEST FLOW ALOFT REMAINS FORECAST DURING EARLY NEXT
WEEK...WITH COLD AIR ADVECTION DEVELOPING BEHIND THE SATURDAY
SYSTEM. SUNDAY NIGHT/MONDAY MORNING COULD VERY WELL BE A PERIOD OF
WIND CHILL CONCERNS AGAIN. THE 925MB TEMPERATURES IN THE -15C TO
-20C RANGE ONCE AGAIN COULD SUPPORT NEGATIVE DOUBLE DIGIT LOWS IN
MOST OUTLYING AREAS ON MONDAY NIGHT WHERE LONG RANGE GUIDANCE
INDICATES HIGH PRESSURE AND A CLEAR SKY OVER THE FRESHENED SNOW
PACK. HAVE LEANED TOWARD A RAW BLEND OF GUIDANCE /NO MOS/ IN THAT
PERIOD...AND EVEN UNDERCUT THAT BY A FEW DEGREES. WITH THE HIGH
PRESSURE AND DEGREE OF SUBSIDENCE MOVING OVERHEAD IT LOOKS LIKE A
POSSIBLE MINI-PERIOD OF DRY WEATHER /OUTSIDE OF FLURRIES/ DURING
SUN THROUGH TUE...AT LEAST AT THIS TIME.
MTF
&&
.CLIMATE...
RECORD COLD HIGHS FOR TODAY FEBRUARY 6TH:
ROCKFORD: 3 DEGREES (1982)
WHILE THIS IS NOT LIKELY TO BE BROKEN TODAY...THE TEMPERATURE AT
MIDNIGHT WAS 2 DEGREES AND IT COULD BE CLOSE THIS AFTERNOON.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* NONE.
KREIN
//DISCUSSION...UPDATED 18Z...
QUIET WEATHER FOR THE AVIATION COMUNITY WILL CONTINUE THROUGH THE
PERIOD. WITH HIGH PRESSURE BUILDING ACTOSS THE MIDDLE MISSISSIPPI
VALLEY THROUGH THE OHIO VALLEY...SKIES ARE MOSTLY CLEAR WITH ONLY
A FEW FRAGMENTS OF STRATOCU OR CIRRUS. WINDS WILL BE OUT OF THE
WEST THROUGH THE REMAINDER OF THE DAY BEFORE GRADUALLY BACKING A
LITTLE MORE SWLY THROUGH THE EVENING AND OVERNIGHT. AMPLE SUNSHINE
WILL ALLOW FOR SOME MIXING THROUGH THE DAYTIME HOURS...SO...WILL
MAINTAIN THE GUSTS IN THE UPPER TEENS. SOME MID LEVEL MOISTURE IS
EXPECTION TO OVERSPREAD THE REGION TONIGHT...BRINGING SOME SCT-BKN
WITH BASES AT 8KFT-10KFT...BUT NOTHING OPERATIONALLY SIGNIFICANT.
CONDITIONS TOMORROW WILL CONTINUE TO BE QUIET...WITH SWLY WINDS
AND MOSTLY CLEAR SKIES.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN ALL FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...VFR.
SATURDAY...SNOW LIKELY WITH SOME ACCUMULATION. IFR PSBL.
SUNDAY THROUGH WEDNESDAY...VFR LIKELY.
BMD
&&
.MARINE...
258 AM CST
AN EXPANSIVE AREA OF HIGH PRESSURE SPANS FROM THE CANADIAN ROCKIES
ACROSS THE CENTRAL PLAINS WITH A RIDGE EXTENDING EAST ALONG THE OHIO
RIVER VALLEY. WITH LOW PRESSURE SPINNING OVER HUDSON BAY...THIS WILL
LEAVE LAKE MICHIGAN IN A PERIOD OF MODERATE WESTERLY FLOW STARTING
LATER TODAY AS WINDS RAMP BACK UP TO AROUND 30 KT. WITH TEMPS
FALLING INTO THE SINGLE DIGITS ACROSS MAINLY THE NORTH HALF OF THE
LAKE...CONDITIONS ARE FAVORABLE FOR FREEZING SPRAY TO DEVELOP. THE
THREAT WILL DIMINISH FRIDAY NIGHT AS THE WINDS BEGIN TO SUBSIDE. LOW
PRESSURE WILL MOVE ACROSS THE SOUTHERN LAKE REGION OVER THE
WEEKEND...WITH ANOTHER COLD CANADIAN HIGH BUILDING BACK INTO THE
MIDWEST AND GREAT LAKES EARLY NEXT WEEK WITH LIGHT FLOW EXPECTED.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WIND CHILL ADVISORY...ILZ003-ILZ004-ILZ005-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ019-ILZ020-ILZ021-ILZ032...9 PM THURSDAY TO 11 AM
FRIDAY.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1212 PM CST THU FEB 6 2014
.DISCUSSION...
952 AM CST
WE WILL BE LETTING THE WIND CHILL ADVISORY FOR THIS MORNING EXPIRE
AT 10 AM. SEVERAL SITES OUT WEST ARE STILL HOVERING RIGHT AROUND
-20 FOR THE WIND CHILL...BUT THESE AREAS SHOULD IMPROVE SOME INTO
NEXT HOUR OR TWO...AND WE FELT THAT IT WAS NOT WORTH EXTENDING THE
ADVISORY FOR ANOTHER HOUR OR TWO. OTHERWISE...NO MAJOR CHANGES TO
THE GOING FORECAST. WE WILL ASSES THE NEED TO EXPAND THE WIND
CHILL ADVISORY FOR TONIGHT INTO FRIDAY ACROSS THE REST OF THE AREA
WITH THE AFTERNOON PACKAGE.
KJB
//PREV DISCUSSION...
333 AM CST
THIS FORECAST WAS FOCUSED ON CURRENT COLD AIR THROUGH FRIDAY AS
WELL AS THE NEXT ROUND EARLY NEXT WEEK...WITH A SNOW EVENT
SANDWICHED IN-BETWEEN ON SATURDAY. THERE SURE HAVE BEEN PLENTY OF
THESE COLD-SNOW-COLD SANDWICHES THIS WINTER!
TODAY...
FROM A MASSIVE STORM SYSTEM YESTERDAY MORNING TO A MASSIVE HIGH
PRESSURE THIS MORNING...THE PROGRESSIVE FLOW CONTINUES. THIS
MORNINGS HIGH CENTERED AT 1043MB FROM MT INTO THE CENTRAL PLAINS
IS TRYING TO NUDGE ITS WAY INTO THE AREA. AT THE LEADING EDGE OF
THE 850-925MB THERMAL TROUGH THERE HAVE BEEN UNDULATING POCKETS OF
STRATOCU WITH FLURRIES EARLY THIS MORNING OVER THE FORECAST AREA.
THE RAP ANALYZES THIS WELL AND PROPAGATES THIS CAA/RH EAST OF
THE AREA BY MID-MORNING. COULD BE SOME FEW-SCT FINGERS OF CU TO
REDEVELOP TODAY AS COLD AIR ADVECTION AT THE TOP OF THE MIXED LAYER
CONTINUES THROUGH EARLY AFTERNOON. THIS ALSO COULD BE REALIZED AT
THE SFC WITH TEMPS STEADY OR EVEN SLOWLY DROPPING THROUGH 9-10 AM
IN SOME COMMUNITIES. THE REBOUND WILL BE SMALL TODAY WITH HIGHS
IN THE 5 TO THE 10 ABOVE RANGE...WITH MAYBE 12-14 IN DOWNTOWN
CHICAGO. THOSE ARE A COUPLE-FEW DEGREES HIGHER THAN INHERITED AND
THIS CLIMB WAS BECAUSE THESE EARLY MORNING CLOUDS THAT HAVE KEPT
SOME READINGS UP.
TONIGHT/FRIDAY...
THE HIGH PRESSURE WILL EXPAND EAST INTO THE MID-MISSISSIPPI
VALLEY BY LATE THIS EVE AND WEAKEN SLOWLY AS IT DOES. WE SHOULD
MAINTAIN SOME WIND COMPONENT...ALTHOUGH SUSPECT THAT GUIDANCE MAY
BE TOO HIGH ON WIND SPEEDS AS THEY OFTEN CAN BE AT NIGHT AND OVER
SNOW COVER. EVEN WITH 5-8 KT WINDS...WIND CHILL ADVISORY CRITERIA
LOOKS TO BE REACHED IN A GOOD PART OF THE AREA THAT IS UNDER THE
CURRENT WIND CHILL ADVISORY. AS FOR ACROSS THE SOUTHERN FORECAST
AREA...WHICH IS CLOSEST TO THE ACTIVE JET ACROSS THE SOUTHERN
U.S...THERE WILL LIKELY BE AT LEAST SOME THIN CIRRUS...IF NOT
BROKEN. SO A BIT MORE MARGINAL THERE. HAVE GONE WITH A WIND CHILL
ADVISORY FOR TONIGHT/FRIDAY IN THE CURRENT ADVISORY AREA TO GET
THE MESSAGE OUT. WILL LET DAY SHIFT ASSESS IF IT NEEDS TO BE
EXPANDED EAST...INCLUDING INTO THE CHICAGO METRO AREA. SOUTHWEST
FLOW GRADUALLY STARTS TO ENVELOP THE AREA FRIDAY BEHIND THE
HIGH...SO A HANDFUL OF DEGREES ARE EXPECTED TO BE ADDED TO TODAYS
HIGHS...WITH 10 TO 15 FORECAST ON FRIDAY.
SATURDAY/SATURDAY NIGHT...
GOOD AGREEMENT IN GUIDANCE ON MASS FIELDS REMAINS THE CASE THROUGH
THE FIRST HALF OF THE WEEKEND...WITH A STRONG WESTERLY UPPER JET
MOVING OVER THE WEST COAST AND ADVANCING EAST INTO THE CENTRAL
PLAINS. A QUICK-MOVING SORT OF HYBRID PACIFIC/CLIPPER SYSTEM IS
EXPECTED TO PROGRESS WITH THE LEFT EXIT REGION OF THIS INTO THE
AREA. DIFFERENCES DO EXIST IN GUIDANCE IN HOW IT EVOLVES THE LOW-
LEVEL FEATURES...WITH THE 00Z/06Z NAM BEING 10MB DEEPER THAN THE
00Z EC ON THE SURFACE WAVE...AND ACTUALLY THE ONLY MODEL SHOWING A
DEEPENING TREND IN THE SFC WAVE AS IT MOVES EAST OVER THE FORECAST
AREA. WHILE THE NAM CAN BE A BIT ROBUST ON DAY 3 IT SEEMS...THE
PV ANOMALY ASSOCIATED WITH THE UPPER TROUGH IS QUITE STRONG AND
ITS ORIENTATION WOULD FAVOR A LOW TO AT LEAST HOLD ITS INTENSITY
AS IT MOVES OVER THE AREA. SO AGAIN LEAN WITH THE MIDDLE GROUND
00Z GFS...WHICH ALSO HAS A MIDDLE GROUND QPF FORECAST.
THE IMPRESSIVE FEATURE WITH THIS IS THE MID-LEVEL VORT MAGNITUDE
AND ITS ADVECTION...DIRECTLY OVER AT LEAST PART OF THE FORECAST AREA
ON GUIDANCE...AND IT TIGHTENS THE BAROCLINIC ZONE TO WHERE IT
WOULD SEEM TEMPORARY BANDING COULD BE A CONCERN. THE GFS ALSO WOULD
SUGGEST THE DENDRITIC GROWTH ZONE IS LIKELY TO BE TAPPED AND GIVEN
A LIMITED RETURN FLOW PERIOD...WOULD EXPECT THE COLUMN TO BE COOL
ENOUGH TO PRESENT THIS AS A POSSIBLE CONCERN. SO HAVE GONE TOWARD
15:1 RATIOS IN INITIAL SNOW FORECAST. VORT MAGNITUDE USING
EMPIRICAL LEMO TECHNIQUE WOULD SUPPORT AT LEAST A FEW INCH STRIPE
OF SNOW SOMEWHERE...BUT WE WILL HAVE TO SEE AS WE GET CLOSER...AS
DURATION OF SNOW COULD OVERALL BE LIMITED IF EARLY SATURATION IS
AN ISSUE. WHILE CONTINUED THE TREND TO INCH UP POPS...NOW WITH 70
PERCENTS ACROSS MUCH OF NORTHERN IL ON SATURDAY. DID NOT GET FANCY
TRYING TO BREAK OUT MORNING VS AFTERNOON...BUT SOME TEMPORAL
RESOLUTION WILL INEVITABLY BE ABLE TO BE ADDED IN TIME.
SUNDAY AND BEYOND...
NORTHWEST FLOW ALOFT REMAINS FORECAST DURING EARLY NEXT
WEEK...WITH COLD AIR ADVECTION DEVELOPING BEHIND THE SATURDAY
SYSTEM. SUNDAY NIGHT/MONDAY MORNING COULD VERY WELL BE A PERIOD OF
WIND CHILL CONCERNS AGAIN. THE 925MB TEMPERATURES IN THE -15C TO
-20C RANGE ONCE AGAIN COULD SUPPORT NEGATIVE DOUBLE DIGIT LOWS IN
MOST OUTLYING AREAS ON MONDAY NIGHT WHERE LONG RANGE GUIDANCE
INDICATES HIGH PRESSURE AND A CLEAR SKY OVER THE FRESHENED SNOW
PACK. HAVE LEANED TOWARD A RAW BLEND OF GUIDANCE /NO MOS/ IN THAT
PERIOD...AND EVEN UNDERCUT THAT BY A FEW DEGREES. WITH THE HIGH
PRESSURE AND DEGREE OF SUBSIDENCE MOVING OVERHEAD IT LOOKS LIKE A
POSSIBLE MINI-PERIOD OF DRY WEATHER /OUTSIDE OF FLURRIES/ DURING
SUN THROUGH TUE...AT LEAST AT THIS TIME.
MTF
&&
.CLIMATE...
RECORD COLD HIGHS FOR TODAY FEBRUARY 6TH:
ROCKFORD: 3 DEGREES (1982)
WHILE THIS IS NOT LIKELY TO BE BROKEN TODAY...THE TEMPERATURE AT
MIDNIGHT WAS 2 DEGREES AND IT COULD BE CLOSE THIS AFTERNOON.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* NONE.
KREIN
//DISCUSSION...UPDATED 18Z...
QUIET WEATHER FOR THE AVIATION COMUNITY WILL CONTINUE THROUGH THE
PERIOD. WITH HIGH PRESSURE BUILDING ACTOSS THE MIDDLE MISSISSIPPI
VALLEY THROUGH THE OHIO VALLEY...SKIES ARE MOSTLY CLEAR WITH ONLY
A FEW FRAGMENTS OF STRATOCU OR CIRRUS. WINDS WILL BE OUT OF THE
WEST THROUGH THE REMAINDER OF THE DAY BEFORE GRADUALLY BACKING A
LITTLE MORE SWLY THROUGH THE EVENING AND OVERNIGHT. AMPLE SUNSHINE
WILL ALLOW FOR SOME MIXING THROUGH THE DAYTIME HOURS...SO...WILL
MAINTAIN THE GUSTS IN THE UPPER TEENS. SOME MID LEVEL MOISTURE IS
EXPECTION TO OVERSPREAD THE REGION TONIGHT...BRINGING SOME SCT-BKN
WITH BASES AT 8KFT-10KFT...BUT NOTHING OPERATIONALLY SIGNIFICANT.
CONDITIONS TOMORROW WILL CONTINUE TO BE QUIET...WITH SWLY WINDS
AND MOSTLY CLEAR SKIES.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN ALL FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...VFR.
SATURDAY...SNOW LIKELY WITH SOME ACCUMULATION. IFR PSBL.
SUNDAY THROUGH WEDNESDAY...VFR LIKELY.
BMD
&&
.MARINE...
258 AM CST
AN EXPANSIVE AREA OF HIGH PRESSURE SPANS FROM THE CANADIAN ROCKIES
ACROSS THE CENTRAL PLAINS WITH A RIDGE EXTENDING EAST ALONG THE OHIO
RIVER VALLEY. WITH LOW PRESSURE SPINNING OVER HUDSON BAY...THIS WILL
LEAVE LAKE MICHIGAN IN A PERIOD OF MODERATE WESTERLY FLOW STARTING
LATER TODAY AS WINDS RAMP BACK UP TO AROUND 30 KT. WITH TEMPS
FALLING INTO THE SINGLE DIGITS ACROSS MAINLY THE NORTH HALF OF THE
LAKE...CONDITIONS ARE FAVORABLE FOR FREEZING SPRAY TO DEVELOP. THE
THREAT WILL DIMINISH FRIDAY NIGHT AS THE WINDS BEGIN TO SUBSIDE. LOW
PRESSURE WILL MOVE ACROSS THE SOUTHERN LAKE REGION OVER THE
WEEKEND...WITH ANOTHER COLD CANADIAN HIGH BUILDING BACK INTO THE
MIDWEST AND GREAT LAKES EARLY NEXT WEEK WITH LIGHT FLOW EXPECTED.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WIND CHILL ADVISORY...ILZ003-ILZ004-ILZ005-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ019-ILZ020-ILZ021-ILZ032...9 PM THURSDAY TO 11 AM
FRIDAY.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS GRAY ME
216 PM EST THU FEB 6 2014
.SYNOPSIS...
HIGH PRESSURE BUILDS ACROSS THE REGION THROUGH SATURDAY...PRODUCING
A SPELL OF FAIR BUT COLD WEATHER. LOW PRESSURE TRACKS SOUTH OF THE
REGION SUNDAY INTO MONDAY...AND MAY BRING SOME SNOW TO THE REGION.
HIGH PRESSURE RETURNS FOR TUESDAY AND WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
OVERNIGHT MIN TEMPERATURE FORECAST WILL BE A CHALLENGE OVERNIGHT
AND HIGHLY DEPENDENT ON THE TIMING OF CLOUD COVER OVER THE REGION
LATER THIS EVENING. IT WILL BE WARMER DUR TO THIS INSOLATING
FACTOR WITH TEMPS AT OR ABOVE ZERO IN THE MOUNTAINS TO ABOUT 10
ABOVE AT THE COAST.
LATEST HRRR MODEL RUN CONTINUES TO SHOW PRECIPITATION WITH THE
OFFSHORE STREAMERS DURING THE FIRST HALF OF TONIGHT. WINDS SWITCH
TO THE WEST...MOVING THE SNOW SHOWERS PERPENDICULAR TO THE
SHORE...BUT REMAINING WELL OFF THE COASTLINE. A FEW UPSLOPE SNOW
SHOWERS MAY DEVELOP IN THE MOUNTAINS LATE TONIGHT.
&&
.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
DOWNSLOPING WINDS WILL ALLOW FOR MORE SUN OVER SOUTHERN PORTIONS
OF ME/NH TOMORROW...WITH LOW CLOUDINESS AND MOISTURE BEING HUNG UP
IN THE WNW FACING HIGHER TERRAIN. THE SUNSHINE OVER SOUTHERN AREAS
SHOULD ALLOW TEMPERATURES TO APPROACH NEAR NORMAL LEVELS FOR
AFTERNOON HIGHS...PUSHING 30 DEGREES ALONG THE COASTLINE WHERE BEST
DIABATIC WARMING TAKES PLACE.
A WEAK FRONT WILL APPROACH FROM THE NORTHWEST FRIDAY NIGHT. THIS
WILL ALLOW MORE MOISTURE TO ENTER THE NORTHERNMOST MOUNTAINS IN
THE FORM OF CLOUDS AND PERHAPS SCATTERED FLURRIES.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
MODELS IN GENERAL AGREEMENT ON BROAD TROUGHING ACROSS THE REGION
WITH A CONTINUATION OF BELOW NORMAL TEMPERATURES. A SERIES OF IMPULSES
WILL RACE EAST ACROSS THE CONUS BEFORE EXITING THE MID ATLANTIC
IN THE LATE SUNDAY - EARLY MONDAY TIMEFRAME. THE SYSTEM WILL BE
PROGRESSIVE AND THERE REMAINS SOME UNCERTAINTY ON ITS EVENTUAL
IMPACT ON THE FORECAST AREA. HOWEVER...THE TREND OVER THE PAST
SEVERAL DAYS HAS BEEN WEAKER AND LITTLE IF ANY PHASING OF ENERGY
WHICH SUPPORTS A RATHER BENIGN SYSTEM. WITH THE EXCEPTION OF THIS
SYSTEM...IT`S SHAPING UP TO BE RATHER QUIET HERE OVER THE NEXT
WEEK. IN THE DAILIES...HIGH PRESSURE WILL BUILD TO THE SOUTH OF
THE AREA SATURDAY. LOW PRESSURE WILL PASS WELL SOUTH AND EAST OF
THE REGION LATE SUNDAY INTO MONDAY. HIGH PRESSURE FOLLOWS THIS
SYSTEM MONDAY NIGHT THROUGH WEDNESDAY.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
SHORT TERM...MAINLY VFR THROUGH TOMORROW NIGHT.
LONG TERM...
SUN PM - MON AM...AREAS OF MVFR IN SNOW ARE POSSIBLE.
&&
.MARINE...
SHORT TERM...SEAS STILL NEAR 5 FEET ALONG THE OUTER COASTAL
WATERS. HOWEVER...THE TREND IS DOWN AND WE WILL BE LOWERING THE
SCAS WITH THIS AFTERNOON FORECAST PACKAGE.
LONG TERM...
SAT...SMALL CRAFT WINDS AND SEAS ARE POSSIBLE.
MON - TUE...SMALL CRAFT WINDS AND SEAS ARE POSSIBLE.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
JC/ES
AREA FORECAST DISCUSSION
NWS GRAY ME
1150 AM EST THU FEB 6 2014
.SYNOPSIS...
HIGH PRESSURE BUILDS ACROSS THE REGION TODAY THROUGH
SATURDAY...PRODUCING A SPELL OF FAIR BUT COLD WEATHER. LOW
PRESSURE TRACKS SOUTH OF THE REGION SUNDAY INTO MONDAY...AND MAY
BRING SOME SNOW TO THE REGION. HIGH PRESSURE RETURNS FOR TUESDAY AND
WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
HAVE UPDATED THE GRIDS BASED ON CURRENT CONDITIONS. TEMPS WILL
RECOVER FROM A FEW LOCATIONS FALLING TO AS LOW AS 10 BELOW LAST
NIGHT. ALSO...WIND DIRECTION ALONG THE MARINE LAYER WILL BE
SUFFICIENTLY FROM THE NORTHWEST...KEEPING STREAMERS OFFSHORE.
LATEST HRRR RUN SHOWS THESE STREAMER MOVING PARALLEL TO THE
COAST...BUT OFFSHORE BY THIS EVENING AS FLOW BECOMES MORE WEST...SOUTHWESTERLY.
PREV DISC...
HIGH PRESSURE AXIS NUDGES INTO WESTERN NEW ENGLAND TODAY...
WITH A LIGHT NORTHERLY FLOW ACROSS THE FORECAST AREA. SHOULD SEE
CLOUDS DISSIPATING AND GIVING WAY TO A MOSTLY SUNNY SKY... BUT
TEMPERATURES WILL BE A LITTLE BELOW NORMAL WITH HIGHS IN THE 20S.
&&
.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
A WEAK TROUGH MOVES INTO NORTHERN NEW ENGLAND TONIGHT AND WILL
BRING A FEW MORE CLOUDS AND A LOW CHANCE OF SNOW SHOWERS TO THE
MOUNTAINS. TEMPERATURES FALL OFF INTO THE SINGLE DIGITS AWAY FROM
THE IMMEDIATE COAST... AND BELOW ZERO IN NORTHERN VALLEYS.
MORE QUIET WEATHER EXPECTED FOR FRIDAY AS HIGH PRESSURE AND A FLAT
ZONAL FLOW CONTINUE TO KEEP A COOL AIR MASS IN PLACE WITH NO
SIGNIFICANT DISTURBANCES TO PROVIDE PRECIPITATION.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
MID LATITUDES IN THE WESTERN HALF OF THE NORTHERN HEMISPHERE WILL
FEATURE WEAKLY AMPLIFIED FLOW AT 500 MB THROUGH THE FORECAST
PERIOD... WITH SEVERAL WEAK WAVES MOVING THRU THE NORTHERN AND
SOUTHERN STREAMS... BUT NO PHASING FOR ANY COMPLEX SYSTEMS TO
DEVELOP. POLAR VORTEX IS SITUATED IN ITS NORMAL POSITION NEAR
HUDSON BAY AND THE MEAN AREA OF WEAK TROUGHING WILL TAP INTO THIS
SOURCE FOR COLDER AIR AND KEEP TEMPERATURES RUNNING BELOW NORMAL
THRU THE PERIOD... BUT NOT SIGNIFICANTLY SO... WITH HIGHS
GENERALLY RUNNING 5-10 F BELOW NORMAL... AND LOWS SHOWING SLIGHTLY
LESS OF A DEPARTURE FROM NORMAL.
AS FAR AS PRECIPITATION GOES... NEXT CHANCE FOR ANY WILL BE LATE
SUNDAY INTO MONDAY... AS SURFACE LOW TRACKS SOUTH OF THE REGION...
AND COULD BRING SOME LIGHT SNOW TO THE AREA. 00Z EURO IS EVEN
FURTHER SOUTH THAN PREVIOUS RUNS... AND WOULD SEE VERY LIGHT
ACCUMULATIONS IF ANY AT ALL. THE GFS STILL HANGING ONTO THE IDEA
OF AN INVERTED TROUGH... WHICH WOULD BRING SOME ACCUMULATION TO
THE AREA... BUT EXPERIENCE SAYS THAT MODELS TEND TO OVERDO THESE
INVERTED TROUGHS... ESPECIALLY THIS FAR OUT IN THE FORECAST. STILL
ENOUGH THERE TO HANG ONTO THE CHANCE POPS.
BEHIND THIS SYSTEM WILL SEE TEMPERATURES DROP A FEW DEGREES... AS
HIGH PRESSURE BUILDS IN FOR THE MIDDLE OF NEXT WEEK... WITH THE
POSSIBILITY OF ANOTHER COASTAL LOW IN THE VICINITY ON THURSDAY.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
SHORT TERM...VFR CONDITIONS EXPECTED WITH LIGHT WINDS. LOWER
CLOUDS MAY HANG ON A LITTLE LONGER TO THE WEST/NORTH OF THE
MOUNTAINS THIS MORNING BUT EVEN THIS SHOULD GIVE WAY TO VFR.
LONG TERM...MAINLY VFR. LOW PRESSURE PASSING TO OUR SOUTH COULD
PRODUCE SOME FLIGHT RESTRICTIONS IN SNOW LATE SUNDAY INTO
MONDAY... WITH THE BETTER CHANCE AT COASTAL TERMINALS.
&&
.MARINE...
SHORT TERM...SEAS CONTINUE TO BE HIGHER THAN MODEL FORECASTS
ACROSS THE GULF OF MAINE THIS MORNING PRIMARILY DUE TO WIND WAVES
ASSOCIATED WITH THE HIGHER WINDS. THESE WINDS HAVE BEGUN TO
SUBSIDE... AND IT WILL TAKE A WHILE FOR THE WAVE HEIGHTS TO FALL
BELOW 5 FEET. THE SMALL CRAFT ADVISORY CONTINUES UNTIL 4 PM THOUGH
IT MAY BE ABLE TO BE DROPPED EARLIER IF OBSERVATIONS SUPPORT THIS.
LONG TERM...IN GENERAL WINDS SEAS WILL STAY BELOW SCA LEVELS
FRIDAY NIGHT THRU MONDAY... ALTHOUGH CANNOT RULE OUT BORDERLINE
SCA CONDITIONS AS LOW PRESSURE PASSES TO THE SOUTH LATE SUNDAY
INTO MONDAY.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM EST THIS
AFTERNOON FOR ANZ150-152-154.
&&
$$
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
350 PM CST THU FEB 6 2014
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 342 PM CST THU FEB 6 2014
ANOTHER NIGHT...ANOTHER WIND CHILL ADVISORY...THAT IS PRETTY MUCH
ALL THAT CAN BE SAID ABOUT THE SHORT TERM PERIOD. THE ARCTIC
HIGH...WHICH HAS BEEN ON A SLOW MARCH SOUTHEAST THE LAST COUPLE OF
DAYS IS NOW CENTERED DOWN IN THE KC METRO AREA...THOUGH THE CENTRAL
PRESSURE IS NOW UP TO ABOUT 1035 MB...WHICH REPRESENTS ABOUT A 20 MB
DROP IN PRESSURE OVER THE LAST 24 HOURS. DESPITE THE FALLING
PRESSURE...ITS AIRMASS STILL PACKS A GOOD PUNCH...WITH HIGHS TODAY
FIGHTING TO GET ABOVE ZERO HERE AND SINGLE DIGITS HIGHS THIS
AFTERNOON EXISTING ALL THE WAY DOWN TO THE OK/TX PANHANDLES.
IF YOU ARE LOOKING FOR A POSITIVE SIGN OF WARMER WEATHER TO
COME...WE GOT IT TODAY WHEN THE FULL SUNSHINE WAS POWERFUL ENOUGH TO
GENERATE JUST ENOUGH MIXING TO DEVELOP A THIN CU FIELD THIS
AFTERNOON. UNFORTUNATELY...THIS CLOUD COVER WILL QUICKLY GO AWAY
TONIGHT AS THE SUN SETS...LEAVING US WITH ANOTHER STARRY AND COLD
NIGHT. WEST WINDS TONIGHT WILL HAVE SLIGHT WARM ADVECTIVE
PROPERTIES...BUT WILL ONLY BE ENOUGH TO JUST MAKE TONIGHT 2 OR 3
DEGREES WARMER THAN LAST NIGHT. THOSE FAIRLY PERSISTENT 5-10 MPH
WINDS COMBINED WITH LOWS BACK DOWN IN THE NEIGHBORHOOD OF -10 WILL
AGAIN SEND WIND CHILL TEMPERATURES TUMBLING DOWN TO -25 OR
LOWER...HENCE THE REAPPEARANCE OF A WIND CHILL ADVISORY BETWEEN
MIDNIGHT AND 9 AM FRIDAY.
FOR FRIDAY...WINDS WILL DIMINISH AS WE GET INTO A BAGGY RIDGE AXIS
AHEAD OF THE SATURDAY SNOW MAKER. WEAK WAA FROM THE NIGHT BEFORE
WILL ALLOW TEMPS TO WARM CLOSE TO 10 DEGREES ABOVE WHAT WE ARE
SEEING TODAY...BUT THOSE LIGHT WINDS WILL LIMIT MIXING...WHICH WILL
MAKE IT TOUGH TO GET MUCH HIGHER THAN THE LOWER TEENS.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 342 PM CST THU FEB 6 2014
LITTLE CHANGE OVERALL TO THE LONG TERM FORECAST. SNOW EVENT ACROSS
SOUTHERN MN STILL IN THE FORECAST. NEW RUNS OF THE GFS AND NAM THIS
MORNING WERE IN VERY GOOD AGREEMENT CONCERNING THE QPF EXTENT AND
AMOUNTS...AND WITH THE TRACK OF A WEAK SURFACE LOW. THE ECMWF
REMAINS THE OUTLIER IN HANDLING THE UPPER LEVEL SHORTWAVE...AND
STILL DOES NOT DEVELOP A SURFACE LOW AS THE OTHER MODELS DO.
STILL...IT DOES BRING SOME LIGHT SNOW INTO SOUTHERN MINNESOTA AS
WELL. THE 18Z NAM ACTUALLY CAME IN WITH EVEN LESS QPF...BUT WILL
CONTINUE WITH A SLIGHTLY HIGHER AMOUNT IN THE FORECAST GIVEN THE
STRONG FORCING ASSOCIATED WITH THIS WAVE.CONTINUED CATEGORICAL POPS
ACROSS THE SOUTH AS THE I-90 CORRIDOR LOOKS TO BE BEST POSITIONED
FOR THE HIGHEST SNOW AMOUNTS IN THE MPX CWA...BETWEEN 2-3". DESPITE
STRONG FORCING WITH THIS SHORTWAVE...SLIGHTLY LOWERED SNOWFALL
AMOUNTS AS NEW MODEL RUNS CAME IN WITH SLIGHTLY LESS QPF...AND
COLLABORATED SNOW RATIOS INDICATED THOSE NEEDED TO BE LOWERED
SLIGHTLY AS WELL. MODELS TENDED TO SLIGHTLY SLOW THE SYSTEM DOWN AS
WELL...SO WENT AHEAD AND ADJUSTED THE TIMING OF INCREASING POPS
FRIDAY NIGHT TO SLOW IT DOWN JUST A FEW HOURS. SNOW RATIOS WILL BE
CRITICAL IN THIS EVENT AS THE MOISTURE AVAILABLE IS RATHER
LIMITED...BUT THE DENDRITIC GROWTH ZONE VERY DEEP...SO GENERALLY
LIGHT QPF SNOW THAT WILL PILE UP EASILY BEING IN DENDRITIC FORM.
ONCE THE SNOW EVENT ON SATURDAY DEPARTS...YET ANOTHER ARCTIC HIGH
FILLS IN FROM ALBERTA/SASKATCHEWAN WITH TEMPERATURES LOOKING QUITE
COLD MONDAY MORNING WHEN TEENS AND TWENTIES BELOW ZERO RETURN TO THE
REGION. AN ALBERTA CLIPPER LOOKS TO SPREAD LIGHT SNOW THROUGH THE
UPPER MIDWEST TUESDAY NIGHT/WEDNESDAY...WHICH WILL BE FOLLOWED BY A
WARM UP TO NEAR NORMAL TEMPERATURES LATER IN THE WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1202 PM CST THU FEB 6 2014
ONLY CONCERN FOR TAFS IS BATCH OF CLOUD COVER THAT MOVED OUT OF
NODAK AND INTO NW MN THIS MORNING. THEY HAVE BEEN STRUGGLING TO
PUSH SOUTHEAST THIS MORNING...BUT THE RAP AND NAM WANT TO SHOW
THIS CLOUD BANK COMING DOWN ESSENTIALLY I-94 IN ONE FORM OR
ANOTHER. CONFIDENCE NOT OVERLY HIGH ON HOW MUCH THESE CLOUDS WILL
HOLD TOGETHER...SO MAINLY WENT WITH A PERIOD OF SCT025 AT
TERMINALS TO REFLECT MOST LIKELY PERIOD WHEN THIS CLOUD SHIELD OR
ITS REMNANTS WOULD MOVE BY. ONLY AIRPORT TO GET PREDOMINATE MVFR
CIG TREATMENT WAS AXN...BUT WITH MVFR CIGS ONLY A COUNTY AWAY THEY
SHOULD HAVE NO PROBLEM FILTERING INTO THE AXN AREA THIS AFTERNOON.
EARLIER THIS MORNING THESE CLOUDS WERE PRODUCING -SN ACROSS
NODAK...BUT THAT HAS SINCE CEASED...SO INCLUDED NO SNOW MENTION
AT AXN WITH THESE CLOUDS. CONFIDENCE IS HIGH WITH THE REST OF TAF
PERIOD.
KMSP...WILL HAVE TO WATCH THE CLOUD BANK TO THE NW...BUT THERE IS
A POSSIBILITY THAT THERE COULD BE SOME BKN MVFR CIGS FOR A LITTLE
BIT 00Z AND 04Z. OTHERWISE...NO CONCERNS WITH THE REST OF THE TAF.
/OUTLOOK FOR KMSP/
SAT...MVFR/-SN LIKELY WITH IFR POSSIBLE. WINDS WNW AT 5KTS.
SUN...VFR. WINDS NW AT 10KTS.
MON...VFR. WINDS W AT 5KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM CST FRIDAY FOR
MNZ041>045-047>070-073>078-082>085-091>093.
WI...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM CST FRIDAY FOR
WIZ014>016-023>028.
&&
$$
SHORT TERM...MPG
LONG TERM...SPD
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1202 PM CST THU FEB 6 2014
.UPDATE...
ISSUED AT 1202 PM CST THU FEB 6 2014
WITH THE EXPIRATION OF THE WIND CHILL ADVISORY THIS MORNING...WENT
AHEAD AND POSTED YET ANOTHER WIND CHILL ADVY FOR TONIGHT INTO
FRIDAY MORNING. LOWS TONIGHT WILL BE NO MORE THAN 3 DEGREES WARMER
THAT WHAT WAS SEEN LAST NIGHT...AND WITH WINDS EXPECTED TO REMAIN
BETWEEN 5 AND 12 MPH...WE WILL AGAIN SEE WIND CHILL VALUES DROP TO
-25 OR COLDER ACROSS THE ENTIRE MPX CWA.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 359 AM CST THU FEB 6 2014
EARLY MORNING WATER VAPOR IMAGERY TOGETHER WITH 500MB HEIGHTS AND
WINDS SHOWS A BROAD LONGWAVE TROUGH EXPANDING THE ENTIRE BREADTH OF
NORTH AMERICA. THERE WERE A FEW SHORTWAVES LOCATED ON THE POLEWARD
SIDE OF THE JET...BUT THEY ARE NOT EXPECTED TO PRODUCE ANY
PRECIPITATION OVER THE UPPER MIDWEST. AT THE SURFACE A RIDGE OF HIGH
PRESSURE WAS DRAPED ALONG THE UPPER MISSOURI RIVER VALLEY...WHILE A
SURFACE LOW WAS LOCATED ACROSS HUDSON BAY. THIS LED TO PERSISTENT
WEST NORTHWEST WIND OF 5 TO 15 MPH...AND WHEN COMBINED WITH
TEMPERATURES OF -10 TO -15F PRODUCED WIND CHILLS NEAR -30F.
OVER THE NEXT 24 HOURS HIGH PRESSURE WILL CONTINUE TO BUILD DOWN THE
MISSOURI RIVER VALLEY. THE WINDS ACROSS MN/WI WILL GRADUALLY TAKE ON
A SOUTHERLY COMPONENT BY FRIDAY MORNING...BUT RADIATIONAL COOLING
WILL OVERTAKE THE WEAK WARM AIR ADVECTION AND THURSDAY NIGHT
TEMPERATURES WILL STILL FALL BELOW ZERO ONCE AGAIN. DESPITE THE
LIGHT SNOW THAT FELL ON WEDNESDAY...WOULD LIKE TO DOUBLE DOWN ON A
DRY FORECAST FOR REDEMPTION AS CONFIDENCE REMAINS HIGH THAT NO
PRECIPITATION WILL FALL NOW THROUGH FRIDAY MORNING.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 359 AM CST THU FEB 6 2014
SURPRISE SURPRISE THE BIGGEST STORY FOR THE LONG TERM IS THE
COLD...BUT THERE IS A MODEST TWINKLE OF LIGHT AT THE END OF THE
TUNNEL. MORE ON THAT IN A BIT. THE BIGGEST CHANGE OF THIS FORECAST
PACKAGE IS TO CONTINUE BOOSTING CHANCES OF SNOW LATE FRIDAY NIGHT
AND SATURDAY AS MODELS SLOWLY HONE IN ON A COMMON SOLUTION. THE
SURFACE RIDGE WILL SLIDE SOUTHEAST INTO THE OHIO VALLEY FRIDAY
AFTERNOON WITH ZONAL FLOW AND A POWERFUL UPPER JET EXTENDING INTO
THE CENTRAL ROCKIES FROM THE CENTRAL NORTHERN PACIFIC. A SHORT
WAVE ON THE LEADING EDGE OF THIS JET WILL RACE EASTWARD ACROSS THE
NORTHERN ROCKIES AND INTO THE NORTHERN/CENTRAL PLAINS LATE FRIDAY
NIGHT. THE GFS REMAINS THE MOST CONSISTENT SOLUTION AND JUST ABOUT
EVERY ENSEMBLE MEMBER SUPPORTS THE IDEA OF A STRONGER WAVE WITH
MORE ROBUST SNOWFALL. THE NAM AND GEM ARE GENERALLY ALONG THE SAME
LINES AS THE GFS...WITH THE ECMWF THE LEAST CONSISTENT AND
WEAKEST...TO THE POINT WHERE ALMOST NO SNOW FALLS ACROSS THE AREA.
THE ODD THING ABOUT THE ECMWF AS WPC POINTS OUT...MASS FIELDS ARE
SIMILAR TO THE GFS BUT THE SURFACE REFLECTION IS NOT REPRESENTATIVE
AT ALL. THE MID LEVEL ENERGY LOOKS PRETTY IMPRESSIVE WITH A NICE
DEEPENING OF THE 500 AND 700 MB TROUGHS AS IT PASSES THROUGH. THE
700 MB LOW PASSES RIGHT OVERHEAD. OMEGA DOESN/T LOOK NEARLY AS
ROBUST AS THE LAST SYSTEM...BUT THE DENDRITIC GROWTH ZONE IS
RATHER DEEP...EXTENDING FROM THE SURFACE TO ABOUT 650 MB.
ISENTROPIC LIFT IS PRETTY DECENT TOO...BUT MIXING RATIOS ARE
MEAGER AND PW VALUES ONLY REACH ABOUT 1/4 INCH. THERE WILL BE A
WELL DEVELOPED SNOW SHIELD WITH THE DYNAMICS PRESENT BUT THE
INTENSITY IS A BIT IN QUESTION GIVEN THE NEGATIVE FACTORS. LOOKING
AT THE AMOUNT OF MOISTURE AVAILABLE...THINK THE MAX ACCUMULATION
POTENTIAL IS ABOUT 3 INCHES.
THE SNOW WILL TAPER OFF SATURDAY AFTERNOON WITH ANOTHER HIGH
BUILDING INTO THE DAKOTAS SATURDAY NIGHT. EARLY NEXT WEEK LOOKS
REAL COLD WITH HIGHS IN THE SINGLE DIGITS AND LOWS IN THE TEENS
AND POSSIBLY 20S BELOW ZERO.
THE STORM TRACK SHIFTS TOWARD THE CANADIAN BORDER DURING THE
MIDDLE OF NEXT WEEK WITH MILDER AIR /BUT STILL BELOW NORMAL/
PUSHING BACK IN FROM THE SOUTHWEST. EVENTUALLY THE RIDGE BUILDS
BACK UP THE WEST COAST AND A COLDER PATTERN WILL RETURN SOMETIME
LATE IN THE WEEK.
SOMETHING INTERESTING AND A BIT DEPRESSING OF NOTE...THE WARMEST
MEMBER OF THE CFS ONLY REACHES 40 A FEW TIMES DURING THE NEXT 45
DAYS AT MSP. WHAT/S WORSE IS THE COLDEST MEMBER DROPS BELOW ZERO
ABOUT FIVE TIMES AS OFTEN DURING THE SAME PERIOD. WHAT/S WORSE
STILL IS CPC CHOOSING TO IGNORE THE CFS FOR BEING TOO WARM.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1202 PM CST THU FEB 6 2014
ONLY CONCERN FOR TAFS IS BATCH OF CLOUD COVER THAT MOVED OUT OF
NODAK AND INTO NW MN THIS MORNING. THEY HAVE BEEN STRUGGLING TO
PUSH SOUTHEAST THIS MORNING...BUT THE RAP AND NAM WANT TO SHOW
THIS CLOUD BANK COMING DOWN ESSENTIALLY I-94 IN ONE FORM OR
ANOTHER. CONFIDENCE NOT OVERLY HIGH ON HOW MUCH THESE CLOUDS WILL
HOLD TOGETHER...SO MAINLY WENT WITH A PERIOD OF SCT025 AT
TERMINALS TO REFLECT MOST LIKELY PERIOD WHEN THIS CLOUD SHIELD OR
ITS REMNANTS WOULD MOVE BY. ONLY AIRPORT TO GET PREDOMINATE MVFR
CIG TREATMENT WAS AXN...BUT WITH MVFR CIGS ONLY A COUNTY AWAY THEY
SHOULD HAVE NO PROBLEM FILTERING INTO THE AXN AREA THIS AFTERNOON.
EARLIER THIS MORNING THESE CLOUDS WERE PRODUCING -SN ACROSS
NODAK...BUT THAT HAS SINCE CEASED...SO INCLUDED NO SNOW MENTION
AT AXN WITH THESE CLOUDS. CONFIDENCE IS HIGH WITH THE REST OF TAF
PERIOD.
KMSP...WILL HAVE TO WATCH THE CLOUD BANK TO THE NW...BUT THERE IS
A POSSIBILITY THAT THERE COULD BE SOME BKN MVFR CIGS FOR A LITTLE
BIT 00Z AND 04Z. OTHERWISE...NO CONCERNS WITH THE REST OF THE TAF.
/OUTLOOK FOR KMSP/
SAT...MVFR/-SN LIKELY WITH IFR POSSIBLE. WINDS WNW AT 5KTS.
SUN...VFR. WINDS NW AT 10KTS.
MON...VFR. WINDS W AT 5KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM CST FRIDAY FOR
MNZ041>045-047>070-073>078-082>085-091>093.
WI...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM CST FRIDAY FOR
WIZ014>016-023>028.
&&
$$
UPDATE...MPG
SHORT TERM...JRB
LONG TERM...BORGHOFF
AVIATION...MPG
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
1104 AM CST THU FEB 6 2014
.DISCUSSION...UPPER DISTURBANCE IS NOW SWINGING ACROSS THE LOWER MS
RIVER VALLEY...WITH MOSTLY LIGHT PRECIPITATION ONGOING ACROSS
EASTERN TEXAS AND LOUISIANA. THUS FAR...A FEW REPORTS OF FLURRIES
AND/OR LIGHT SLEET HAVE BEEN RECEIVED FROM OUR NE LOUISIANA PARISHES
AND INTO THE NATCHEZ AND BROOKHAVEN AREAS. HOWEVER...MUCH OF THE
PRECIP BEING DETECTED BY RADAR IS NOT REACHING THE GROUND. FOR
INSTANCE...CALLS TO RICHLAND AND FRANKLIN PARISHES UNDER SOME OF THE
20-30 DBZ RETURNS YIELDED NO REPORTS. FARTHER WEST...MAINLY TO THE
WEST OF ALEXANDRIA...WHERE THERE HAS BEEN MORE OPPORTUNITY FOR THE
ATMOSPHERE TO MOISTEN DOWN TO THE SURFACE...LIGHT TO OCCASIONALLY
MODERATE...SNOW IS REACHING THE GROUND MORE EFFECTIVELY. GREATEST
ACCUMULATIONS WE HAVE BEEN MADE AWARE OF IN THAT AREA WERE A DUSTING
IN GRANT PARISH.
MANY HI-RES MODELS HAVE SHOWN A SCARCITY OF QPF ACROSS OUR SOUTHERN
ZONES...HOWEVER THEY HAVE ALSO NOT HAD THE BEST HANDLE ON THE PRECIP
THAT WAS ONGOING ACROSS EAST TEXAS AND PARTS OF WESTERN LOUISIANA
THIS MORNING. THE LATEST RUNS OF THE RAP HAVE BEGUN TO BETTER HANDLE
THE ONGOING PRECIPITATION AND NOW SHOW A CORRIDOR OF QPF (UP TO .1
INCH) SOUTH OF I-20 DOWN TO THE MS/LA BORDER. THE 12Z GFS HAS ALSO
COME IN A BIT WETTER FOR THE SAME AREA.
BASED ON THESE TRENDS AND RECENT REPORTS OF SOME ACCUMULATIONS
BEGINNING ON BRIDGES NW OF ALEXANDRIA...WE HAVE OPTED TO POST A
WINTER WEATHER ADVISORY FOR PORTIONS AREAS SOUTH OF I-20 EASTWARD TO
AROUND HIGHWAY 49. OUR EXPECTATIONS OF LIGHT SNOW AND SLEET
ACCUMULATION BETWEEN A DUSTING TO LESS THAN AN INCH HAVE NOT
CHANGED...BUT WITH TEMPERATURES LINGERING NEAR OR BELOW FREEZING WE
ARE MORE CONCERNED ABOUT SLICK SPOTS DEVELOPING ON ELEVATED ROAD
SURFACES. IT IS POSSIBLE THE ADVISORY WOULD NEED TO LATER BE
EXPANDED FARTHER EASTWARD...BUT FOR NOW WE EXPECT TEMPERATURES TO BE
LESS FAVORABLE FOR ACCUMULATIONS AS PRECIP REACHES SOUTHEAST MS.
FORECAST UPDATES WILL BE SENT WITHIN THE NEXT HOUR.
NOTE: A SPECIAL 18Z UPPER AIR FLIGHT WILL BE CONDUCTED TODAY TO
ASSIST WITH TODAY`S WINTER WEATHER FORECAST. /DL/
&&
.PREV DISCUSSION... /ISSUED AT 432 AM CST THU FEB 6 2014/
SHORT TERM...TODAY THROUGH FRIDAY NIGHT...SOMEWHAT MORE POTENT
SHORTWAVE THAN MODELS HAVE BEEN HANDLING...CURRENTLY MOVING OUT OF
NORTHERN MEXICO...WILL BE THE MAIN FOCUS FOR TODAY. WV IMAGERY
SHOWING INCREASINGLY BACKED FLOW YIELDING INCREASED ISENTROPIC LIFT
AND COOLING CLOUD TOPS AT PRESENT OVER THE LOWER MS VALLEY. GFS BUFR
SOUNDINGS SHOWING SOME POTENTIAL FOR SNOW SHOWERS ACROSS MAINLY
CENTRAL AND SOUTH LATE MORNING INTO EARLY AFTERNOON. MODEL CROSS
SECTIONS CONFIRM THE CONVECTIVE THREAT WITH ELEVATED CAPE VALUES
AROUND 200 J/KG OVER SOUTH MS ALONG WITH 20 UB/S OF OMEGA. ALL THIS
OCCURRING IN THE -5 TO -15C PREFERRED DENDRITIC GROWTH ZONE.
DESPITE THE STRONG VERTICAL MOTION FOR GOOD SNOWFALL...THERE ARE
SOME ROADBLOCKS THAT WILL HAVE TO BE OVERCOME FOR DECENT
ACCUMULATIONS TO OCCUR. FIRST IS THE SPEED OF THE SYSTEM. THERE
LOOKS TO BE ONLY ABOUT A FOUR TO SIX HOUR PERIOD OF TIME WHEN THESE
CONDITIONS WILL EXIST OVER THE AREA. NEXT...BELOW THE ASCENT IS
A VERY DRY LAYER. BELIEVE IT WILL TAKE A COUPLE HOURS OF
PRECIPITATION THROUGH THE DRY LAYER TO SATURATE ENOUGH FOR
ACCUMULATING PRECIPITATION TO MAKE IT TO THE GROUND. BY THIS
TIME...THE MAJORITY OF VERTICAL MOTION WILL HAVE PUSHED EAST. THE
OTHER OBSTACLE WILL BE LOW LEVEL TEMPS. MODEL SOUNDINGS IN THE SOUTH
SHOW A GOOD POSSIBILITY OF SNOW MIXING WITH RAIN AS THERE ARE
SEVERAL BUMPS IN THE TEMPERATURE PROFILE ABOVE FREEZING BELOW THE
ASCENT LAYER. IN ADDITION...SURFACE TEMPS LOOK TO BE ABOVE FREEZING
AT MOST PLACE AT THE ONSET OF SNOW. ALTHOUGH ACCUMULATIONS CAN OCCUR
WHEN TEMPS ARE ABOVE FREEZING...ESPECIALLY WITH HEAVY SNOW...BELIEVE
LISTED LIMITATIONS ABOVE WILL PREVENT A HEAVY SNOW AND ONLY YIELD
LIGHT ACCUMULATIONS (< 1 INCH)...MAINLY ON GRASSY SURFACES...EXPOSED
OBJECTS AND BRIDGES/OVERPASSES. LATEST NAM AND SREF HAVE TRENDED
LIGHTER IN QPF AMOUNTS AS WELL. AFTER COORDINATING WITH SURROUNDING
SITES...WILL HOLD OFF ON ISSUING AN ADVISORY AT THE MOMENT GIVEN
RAISED QUESTION MARKS IN POSSIBLE ACCUMULATIONS.
THE FAST PACED PROGRESSIVE FLOW WILL QUICKLY EJECT TODAYS SYSTEM
EAST TONIGHT WITH NEXT SHORTWAVE POISED TO DROP IN FRIDAY NIGHT.
ONCE AGAIN SHORT TERM ISENTROPIC ASCENT WILL PRODUCE WIDESPREAD
LIGHT RAINS WITH SOMEWHAT WARMER COLUMN THIS TIME. SOME RISK OF
LIGHT FREEZING RAIN WILL EXIST OVER THE FAR NORTHERN SECTIONS NEAR
THE END OF THE EVENT AS SURFACE TEMPS DROP INTO THE LOWER 30S BY
EARLY SATURDAY MORNING./26/
LONG TERM...(SATURDAY THROUGH THURSDAY)...THE PRIMARY CONCERNS WILL
BE A RATHER ACTIVE PATTERN FOR THE PERIOD...SOME OF WHICH COULD BRING
SOME LIGHT WINTER PRECIPITATION IN THE NORTH FOR MONDAY NIGHT INTO
EARLY TUESDAY. THERE IS ANOTHER CHANCE OF RAIN FOR TUESDAY NIGHT INTO
WEDNESDAY THAT WILL BEAR WATCHING IN FUTURE MODEL RUNS. THIS FOLLOWED
BY TEMPS AND POPS IN THE PROGRESSIVE UPPER PATTERN.
FOR SATURDAY MORNING THE PATCHY LIGHT RAIN WILL DEPART FROM THE
REGION BEFORE DRY WEATHER SETS IN FOR SATURDAY AFTERNOON THROUGH
SUNDAY NIGHT WITH A PROGRESSIVE FLOW PATTERN ALOFT. OUR NEXT CHANCE
OF RAIN WILL COME MONDAY AFTERNOON AS WE GET SOME ISENTROPIC LIFT TO
BRING IN SOME SPOTTY LIGHT RAIN. A SOUTHERN STREAM SHORT WAVE WILL
APPROACH THE REGION DURING THE DAY MONDAY AND BRING BRING SOME
BETTER LIFT ACROSS THE REGION ON MONDAY NIGHT INTO TUESDAY. MODEL
SOUNDINGS SHOW THAT THERE WILL BE ENOUGH LOW LEVEL COLD AIR
ADVECTION TO BRING A MIXED BAG OF LIGHT WINTER PRECIPITATION ACROSS
THE NORTH. THIS WAS AGREED UPON BY THE EURO AND GFS MODELS...WHICH
JUST STARTED ON THIS MODEL RUN. BY LATE MONDAY NIGHT EXPECT ENOUGH
COLD AIR IN THE LOWER LEVELS TO MAKE IT ALL LIGHT SNOW IN THE NORTH
WITH LIGHT RAIN ELSEWHERE. AS WE GO INTO TUESDAY MORNING MODEL
SOUNDINGS ACROSS THE NORTH SHOWS THAT THE WARM NOSE WILL DIP FARTHER
TOWARD THE SURFACE...WHICH MAY BRING A LIGHT MIXTURE OF LIGHT
RAIN...LIGHT SLEET AND LIGHT FREEZING RAIN. TEMPS WILL RISE DURING
THE MORNING TO MAKE IT ALL RAIN BY THE AFTERNOON. AS WE GO INTO
TUESDAY NIGHT AND WEDNESDAY THE SOUTHERN STREAM SHORT WAVE WILL
CROSS INTO THE REGION. THE GFS AND EURO HAS SOME DIFFERENT OPINIONS
OF A DEEPENING WAVE ALONG A FRONTAL BOUNDARY. THE GFS HAS IT FARTHER
SOUTH OF THE REGION...THUS BRINGING COLDER AIR INTO THE
REGION...WHICH MAY BRING WINTER PRECIPITATION...WHILE THE EURO HAD
THE DEEPENING LOW CROSSING THE FORECAST AREA..THUS KEEPING IT A COLD
RAIN. SO OPTED TO GO TOWARD THE MILDER EURO SOLUTION. THUS WILL KEEP
IT A COLD RAIN FOR TUESDAY NIGHT INTO WEDNESDAY. THE RAINS WILL MOVE
OUT OF THE AREA BY WEDNESDAY NIGHT.
AS FAR AS TEMPS ARE CONCERNED WENT WITH A BLEND OF MEX AND GMOS FOR
MOST PERIODS. ALSO WENT CLOSE TO ENSEMBLE GUIDANCE FOR MONDAY NIGHT
AND TUESDAY. AS FAR AS POPS ARE CONCERN WENT CLOSE TO MEX GUIDANCE
FOR MOST PERIODS AND ADJUSTED MEN GUIDANCE FOR MONDAY NIGHT INTO
TUESDAY./17/
&&
.AVIATION...MVFR CEILINGS LOOK TO RISE TO VFR BY 18Z THEN CLEARING
ALTOGETHER AFTER 07/00Z. VISIBILITIES SHOULD REMAIN MOSTLY VFR. SOME
RESTRICTIONS MAY DEVELOP FROM KJAN/KHKS...KMEI AND KHBG FROM 16-22Z
IN RAIN AND SNOW SHOWERS AND BRIEFLY DROP TO MVFR./26/
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
DL/26/17
AREA FORECAST DISCUSSION
NWS RALEIGH NC
255 PM EST THU FEB 6 2014
.SYNOPSIS...A WEAK UPPER LEVEL DISTURBANCE WILL CROSS THE REGION
THIS EVENING. POLAR HIGH PRESSURE WILL OTHERWISE BUILD EAST ACROSS
THE MIDDLE ATLANTIC STATES THROUGH FRIDAY.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 100 PM THURSDAY...
REST OF TODAY: AS OF 17Z...BROKEN CLOUD COVER OVER THE CAROLINAS IS
ASSOCIATED WITH UPPER LEVEL MOISTURE ADVECTING INTO THE REGION VIA
SW FLOW ALOFT (DOWNSTREAM OF A SHORTWAVE TRACKING INTO LOUISIANA) IN
ADDITION TO A NARROW CORRIDOR OF MID-LEVEL (H7-H6) FRONTOGENESIS IN
VICINITY OF A LINE EXTENDING SW-NE FROM TROY-RALEIGH-TARBORO. 17Z
REGIONAL RADAR DATA INDICATED A NARROW BAND OF ECHOES (10-25 DBZ)
THAT CORRESPOND WELL WITH THE AFOREMENTIONED ZONE OF FGEN (MOST
PROMINENT BETWEEN 9000-15000 FT AGL). KRAX IS INDICATING FAINT
ECHOES (5-10 DBZ) AS LOW AS 4000 FT AGL OVER NORTHERN MOORE AND LEE
COUNTIES...IMPRESSIVE CONSIDERING THE DRY MID-LEVEL AIRMASS IN PLACE
AT 12Z THIS MORNING (12Z GSO/MHZ RAOBS). THE LATEST RAP GUIDANCE
INDICATES MID-LEVEL FGEN WANING ALONG/EAST OF HWY 1 BETWEEN 18-
21Z...AND THE BOUNDARY LAYER (SFC-4000 FT AGL) APPEARS DRY ENOUGH TO
PRECLUDE ANY CHANCE FOR PRECIP (ASIDE FROM VIRGA) THIS AFTERNOON.
PER OBSERVATION TRENDS AS OF 17-18Z...HIGH TEMPS APPEAR ON TRACK IN
THE LOWER/MID 40S...TEMPERED SLIGHTLY DUE TO DECREASED INSOLATION
ASSOCIATED WITH MID-LEVEL CLOUD COVER. -VINCENT
TONIGHT: THE SHORTWAVE TROUGH FROM THE RIO GRANDE WILL LIFT QUICKLY
NE ACROSS THE CENTRAL APPALACHIANS AND CAROLINAS THIS EVENING. NWP
GUIDANCE HAS CONTINUED TO TREND TOWARD MORE APPRECIABLE/DEEPER
SATURATION ALOFT...WHICH SHOULD SUPPORT WIDESPREAD VIRGA THIS
EVENING. HOWEVER...THE SUB-CLOUD LAYER WILL REMAIN DRY OWING TO
LITTLE OPPORTUNITY FOR MOISTURE RETURN IN THE WAKE OF THE FRONTAL
ZONE THAT PRESSED SOUTH OF OUR REGION DURING THE PAST 12 HOURS...SO
THE LOWERING MID LEVEL CEILINGS WILL HAVE A DIFFICULT TIME PRODUCING
MORE THAN SCATTERED SPRINKLES OR FLURRIES...PER FORECAST PARTIAL
THICKNESS VALUES THAT FALL IN THE WINTRY MIXTURE PORTION OF THE
NOMOGRAM. IF PRECIPITATION WERE TO FALL FOR A LONGER DURATION OR
WITH A GREATER INTENSITY...WET BULB THERMAL PROFILES IN THE BOUNDARY
LAYER WOULD SUPPORT SNOW...BUT AGAIN...NEITHER CRITERIA ARE EXPECTED
TO BE MET FOR THE REASONS OUTLINED ABOVE. WE WILL...HOWEVER...NEED
TO MONITOR THE MOISTURE RETURN SPREADING INLAND ALONG THE WESTERN
GULF COAST THIS MORNING...WHICH IF IT WERE TO LINK UP WITH THE
AFOREMENTIONED SHORTWAVE TROUGH AND ASSOCIATED MOISTURE...WOULD LEAD
TO A BETTER CHANCE OF LIGHT MEASURABLE PRECIPITATION. AT THIS
TIME...HOWEVER...THAT MOISTURE IS FORECAST TO BE SHUNTED EASTWARD
THROUGH CENTRAL GA/SC AND FAR SOUTHEASTERN NC...THEREBY LIMITING ANY
INTERACTION WITH THE APPROACHING LOWS IN THE UPPER 20S TO LOWER 30S.
FRIDAY: SOMEWHAT OF A REPEAT PERFORMANCE OF THE THE PREVIOUS 24
HOURS...AS YET A NEW SHORTWAVE TROUGH DEAMPLIFIES ON AN ALBEIT
SLIGHTLY MORE NORTHERLY TRACK FROM SW US...WHILE THE MODIFIED ARCTIC
HIGH CONTINUES TO RIDGE AROUND THE APPALACHIANS FROM THE WEST. NOT
AS COOL AS THE PARENT HIGH CONTINUES TO MODIFY...AND IS WEAKENED BY
A SURFACE TROUGH IN THE LEE OF THE APPALACHIANS. HIGHS IN THE UPPER
40S TO LOWER 50S. RIVEN LOWS MOSTLY IN THE LOWER 30S. -MWS
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/...
AS OF 255 AM THURSDAY...
FOR FRIDAY NIGHT INTO SATURDAY MORNING A 1030 MB SURFACE HIGH WILL
MOVE ACROSS OHIO AND PENNSYLVANIA WITH A RIDGE EXTENDING DOWN THE
EASTERN SIDE OF THE APPALACHIANS. WHAT BEGINS AS AN INVERTED TROUGH
OFF OF THE COAST OF FLORIDA DEVELOPS INTO A CLOSED LOW OFF OF THE
SC/GA COAST BY 12Z SATURDAY. MODELS DIFFER IN THE TRACK AND TIMING
OF THE LOW WITH THE GFS SLOWER AND FURTHER OFFSHORE AND THE ECMWF
QUICKER AND CLOSER TO THE COAST. THE QUICKER/CLOSER ECMWF CARRIES
THE MOST CONSEQUENCES FOR SENSIBLE WEATHER FOR CENTRAL NC.
THICKNESSES AND WETBULB ZERO TEMPERATURES SUGGEST THAT PRECIPITATION
COULD START OUT AS RAIN OR SNOW WITH THE BEST CHANCES FOR SNOW
FURTHER TO THE NORTH AND WEST...BUT ALSO FURTHER AWAY FROM THE MAIN
MOISTURE SOURCE WHICH WOULD CUT DOWN ANY ACCUMULATION/IMPACTS OF ANY
SNOW THAT DOES FALL INITIALLY. THE SLOWER GFS KEEPS THINGS DRY UNTIL
TEMPERATURES AND THICKNESS INCREASE ENOUGH TO THWART THE THREAT OF
ANY WINTER P-TYPE ISSUES. AFTER 12Z ANY FALLING PRECIP WILL BE
LIQUID WITH THE WETTER ECMWF CARRYING CLOSER TO A HALF AN INCH OF
PRECIP IN THE EAST AND 2 TENTHS OF AN INCH OF THE TRIANGLE WITH LESS
TO THE NORTHWEST. THE GFS ONLY CARRIES 1 TO 2 TENTHS OF AN INCH FROM
THE TRIANGLE EASTWARD. CONFIDENCE IS STILL BELOW AVERAGE ON WHICH OF
THESE SCENARIOS WILL OCCUR BUT WPC PREFERENCES CONTINUE TO BE
WEIGHTED TOWARD THE ECMWF AND THUS WILL INCLUDE THE CHANCE FOR RAIN
OR SNOW IN THE NW THROUGH MID MORNING...AND TRANSITION TO RAIN
THEREAFTER. ALL PRECIPITATION SHOULD EXIT THE EASTERN CWA JUST AFTER
00Z SUNDAY. HIGHS SATURDAY WILL REMAIN COOLER WITH WEDGE IN PLACE
INITIALLY AND THEN OVERCAST THROUGH THE DAY...LOW 40S NW TO NEAR 50
SE. LOWS SATURDAY NIGHT IN THE MID 30S. WITH LOW LEVEL SATURATION
HOLDING THROUGH THE OVERNIGHT HOURS...EXPECT SOME AREAS OF FOG
THROUGH SUNDAY MORNING.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
AS OF 255 PM THURSDAY...
SATURDAY NIGHT...SURFACE LOW OFF THE COAST WILL BE
LIFTING RAPIDLY NORTHEAST..WITH LINGERING LOW LEVEL MOISTURE LOCKED
IN PLACE OVERNIGHT = FOG. SKIES WILL REMAIN CLOUDY WITH PERHAPS SOME
PATCHES OF DRIZZLE WITH TEMPS FALLING INTO THE LOW TO MID 30S.
SUNDAY AND MONDAY FEATURE BROAD TROFFING OVER THE CENTRAL AND
EASTERN CONUS WITH STRONG HIGH PRESSURE BUILDING SOUTH INTO THE
UPPER MIDWEST AND ACROSS THE OHIO VALLEY. SUNDAY WILL BE OUR WARMEST
DAY WITH HIGHS REACHING 50 TO 55 DEGREES. A SHORTWAVE SKIRTS ACROSS
THE NORTHERN TIER OF THE AREA LATER SUNDAY...AND MAY PRODUCE SOME
LIGHT RAIN SHOWERS ACROSS THE NORTHERN TIER LATE IN THE DAY.
HOWEVER...ITS MAIN EFFECT WILL BE TO NUDGE THE LEADING EDGE OF THE
COLDER AIR ACROSS THE OHIO VALLEY SOUTH...EFFECTIVELY A DRY BACKDOOR
COLD FRONT SUNDAY NIGHT. SUNDAY NIGHTS LOWS WILL BE IN THE MID TO
UPPER 20S...AND MONDAYS HIGHS GRADUATED FROM LOW 40S ACROSS THE
NORTH TO NEAR 50 IN THE SOUTHERN TIER.
THE FRONTAL ZONE WILL SET UP SOUTH OF THE AREA AND OFFSHORE AS COLD
AIR CONTINUES TO RIDGE SOUTH THROUGH TUESDAY...REINFORCED BY THE
MIGRATORY 1035MB SURFACE HIGH WANDERING EAST ACROSS SOUTHERN NEW
ENGLAND. HIGHS WILL BE IN THE 40S WITH MOSTLY CLOUDY SKIES DUE TO
MID AND UPPER LEVEL MOISTURE RACING EAST IN FAST NEAR-ZONAL FLOW
ALOFT.
TUESDAY NIGHT THROUGH THURSDAY...OPERATIONAL GFS AND ECMWF DEPICTING
AN ACTIVE SOUTHERN STREAM WITH STRENGTHENING LOW LEVEL FLOW AS
CYCLOGENESIS TAKES PLACE ACROSS THE SOUTHERN GULF STATES. A STRONG
HYBRID/MILLER B DAMMING SCENARIO WILL EVOLVE...WITH WARM AIR
SPREADING PRECIP ACROSS THE COOL DOME LATER TUE NIGHT...BUT
ESPECIALLY WED AND WED NIGHT. INITIAL PRECIP COULD BE SNOW ACROSS
MUCH OF THE NORTH AND WEST AS THE COLUMN WILL BE LARGELY
SUBFREEZING...WITH RAIN ACROSS THE SOUTH. MODEL DIFFERENCES ARE
MINOR ENOUGH CONCLUDE THAT THE MILLER B SCENARIO CONTINUES TO
EVOLVE...AND WITH COLD AIR IN PLACE...A WIDE TRANSITION ZONE BETWEEN
RAIN AND SNOW IS POSSIBLE...EVEN LIKELY TO DEVELOP...ACROSS THE
PIEDMONT ON WEDNESDAY PER CLIMATOLOGY. AT THIS POINT WILL BE RAISING
POPS INTO THE LIKELY CATEGORY WITH RAIN OR SNOW AS PRIMARY WEATHER
TYPES AS DETAILS BECOME MORE CLEAR AND CONFIDENCE INCREASES IN
SUBSEQUENT MODEL RUNS. HIGHS WEDNESDAY WILL BE COOLER THAN
GUIDANCE...WITH THE NORTHWEST POSSIBLY NOT GETTING OUT OF THE MID
30S. MEANWHILE...THE SOUTHEAST COULD REACH 50. A COASTAL LOW IS
EXPECTED TO BECOME DOMINANT AND LIFT NORTH OF THE AREA WEDNESDAY
NIGHT...AND WITH THE LOSS OF THE DEEPER MOISTURE...THE NUCLEATION
ZONE COULD DE-SATURATE TO PRODUCE LIGHT FREEZING RAIN/FREEZING
DRIZZLE ACROSS THE NORTH AND WEST OVERNIGHT. LOWS WILL RANGE FROM 30
NORTHWEST TO 36 IN THE SOUTHEAST. ON THURSDAY...THERE WILL BE THE
POTENTIAL FOR LINGERING PRECIP...AND POSSIBLY SOME FREEZING
DRIZZLE...WITH HIGHER POPS NORTH AND WEST WHERE LOW LEVEL MOISTURE
WILL BE LOCKED IN PLACE BY THE NORTHERLY FLOW BEHIND THE DEPARTING
LOW. THURSDAYS HIGHS WILL BE MOSTLY IN THE 40S...REACHING THE LOW
40S LATE IN DAY (IF AT ALL) IN THE NORTHWEST.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 100 PM THURSDAY...
24-HR TAF PERIOD: VFR CONDITIONS WITH CEILINGS 12-18 KFT WILL
PREVAIL THROUGH 00Z THIS EVENING. A SHORTWAVE DISTURBANCE TRACKING
NORTHEAST THROUGH THE DEEP SOUTH THIS AFTERNOON WILL CROSS THE
CAROLINAS LATE THIS EVENING. A SHORT PERIOD (~3 HRS) OF MVFR
CEILINGS CANNOT BE RULED OUT IN THE 03-09Z TIME FRAME AT THE KFAY
TERMINAL...PERHAPS THE KRDU/KRWI TERMINALS AS WELL...AND HAVE
INCLUDED A TEMPO GROUP BETWEEN 04-08Z TO ACCOUNT FOR THIS
POSSIBILITY. NORTHERLY WINDS AT 5-10 KT WILL WEAKEN AND BECOME
LIGHT/VARIABLE THIS AFTERNOON...WITH LIGHT/VARIABLE WINDS PERSISTING
THROUGH THE DAY FRIDAY.
LOOKING AHEAD: VFR CONDITIONS AND LIGHT WINDS WILL PREVAIL ON
FRIDAY. SUB-VFR CONDITIONS AND PRECIPITATION WILL BE POSSIBLE DURING
THE DAY SATURDAY...LATE SUNDAY...AND AGAIN LATE MONDAY NIGHT THROUGH
TUESDAY AS A SERIES OF STORM SYSTEMS AFFECT THE CAROLINAS AND
VIRGINIA. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...MWS/VINCENT
SHORT TERM...ELLIS
LONG TERM...MLM
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
102 PM EST THU FEB 6 2014
.SYNOPSIS...A WEAK UPPER LEVEL DISTURBANCE WILL CROSS THE REGION
THIS EVENING. POLAR HIGH PRESSURE WILL OTHERWISE BUILD EAST ACROSS
THE MIDDLE ATLANTIC STATES THROUGH FRIDAY.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 100 PM THURSDAY...
REST OF TODAY: AS OF 17Z...BROKEN CLOUD COVER OVER THE CAROLINAS IS
ASSOCIATED WITH UPPER LEVEL MOISTURE ADVECTING INTO THE REGION VIA
SW FLOW ALOFT (DOWNSTREAM OF A SHORTWAVE TRACKING INTO LOUISIANA) IN
ADDITION TO A NARROW CORRIDOR OF MID-LEVEL (H7-H6) FRONTOGENESIS IN
VICINITY OF A LINE EXTENDING SW-NE FROM TROY-RALEIGH-TARBORO. 17Z
REGIONAL RADAR DATA INDICATED A NARROW BAND OF ECHOES (10-25 DBZ)
THAT CORRESPOND WELL WITH THE AFOREMENTIONED ZONE OF FGEN (MOST
PROMINENT BETWEEN 9000-15000 FT AGL). KRAX IS INDICATING FAINT
ECHOES (5-10 DBZ) AS LOW AS 4000 FT AGL OVER NORTHERN MOORE AND LEE
COUNTIES...IMPRESSIVE CONSIDERING THE DRY MID-LEVEL AIRMASS IN PLACE
AT 12Z THIS MORNING (12Z GSO/MHZ RAOBS). THE LATEST RAP GUIDANCE
INDICATES MID-LEVEL FGEN WANING ALONG/EAST OF HWY 1 BETWEEN 18-
21Z...AND THE BOUNDARY LAYER (SFC-4000 FT AGL) APPEARS DRY ENOUGH TO
PRECLUDE ANY CHANCE FOR PRECIP (ASIDE FROM VIRGA) THIS AFTERNOON.
PER OBSERVATION TRENDS AS OF 17-18Z...HIGH TEMPS APPEAR ON TRACK IN
THE LOWER/MID 40S...TEMPERED SLIGHTLY DUE TO DECREASED INSOLATION
ASSOCIATED WITH MID-LEVEL CLOUD COVER. -VINCENT
TONIGHT: THE SHORTWAVE TROUGH FROM THE RIO GRANDE WILL LIFT QUICKLY
NE ACROSS THE CENTRAL APPALACHIANS AND CAROLINAS THIS EVENING. NWP
GUIDANCE HAS CONTINUED TO TREND TOWARD MORE APPRECIABLE/DEEPER
SATURATION ALOFT...WHICH SHOULD SUPPORT WIDESPREAD VIRGA THIS
EVENING. HOWEVER...THE SUB-CLOUD LAYER WILL REMAIN DRY OWING TO
LITTLE OPPORTUNITY FOR MOISTURE RETURN IN THE WAKE OF THE FRONTAL
ZONE THAT PRESSED SOUTH OF OUR REGION DURING THE PAST 12 HOURS...SO
THE LOWERING MID LEVEL CEILINGS WILL HAVE A DIFFICULT TIME PRODUCING
MORE THAN SCATTERED SPRINKLES OR FLURRIES...PER FORECAST PARTIAL
THICKNESS VALUES THAT FALL IN THE WINTRY MIXTURE PORTION OF THE
NOMOGRAM. IF PRECIPITATION WERE TO FALL FOR A LONGER DURATION OR
WITH A GREATER INTENSITY...WET BULB THERMAL PROFILES IN THE BOUNDARY
LAYER WOULD SUPPORT SNOW...BUT AGAIN...NEITHER CRITERIA ARE EXPECTED
TO BE MET FOR THE REASONS OUTLINED ABOVE. WE WILL...HOWEVER...NEED
TO MONITOR THE MOISTURE RETURN SPREADING INLAND ALONG THE WESTERN
GULF COAST THIS MORNING...WHICH IF IT WERE TO LINK UP WITH THE
AFOREMENTIONED SHORTWAVE TROUGH AND ASSOCIATED MOISTURE...WOULD LEAD
TO A BETTER CHANCE OF LIGHT MEASURABLE PRECIPITATION. AT THIS
TIME...HOWEVER...THAT MOISTURE IS FORECAST TO BE SHUNTED EASTWARD
THROUGH CENTRAL GA/SC AND FAR SOUTHEASTERN NC...THEREBY LIMITING ANY
INTERACTION WITH THE APPROACHING LOWS IN THE UPPER 20S TO LOWER 30S.
FRIDAY: SOMEWHAT OF A REPEAT PERFORMANCE OF THE THE PREVIOUS 24
HOURS...AS YET A NEW SHORTWAVE TROUGH DEAMPLIFIES ON AN ALBEIT
SLIGHTLY MORE NORTHERLY TRACK FROM SW US...WHILE THE MODIFIED ARCTIC
HIGH CONTINUES TO RIDGE AROUND THE APPALACHIANS FROM THE WEST. NOT
AS COOL AS THE PARENT HIGH CONTINUES TO MODIFY...AND IS WEAKENED BY
A SURFACE TROUGH IN THE LEE OF THE APPALACHIANS. HIGHS IN THE UPPER
40S TO LOWER 50S. RIVEN LOWS MOSTLY IN THE LOWER 30S. -MWS
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/...
AS OF 255 AM THURSDAY...
FOR FRIDAY NIGHT INTO SATURDAY MORNING A 1030 MB SURFACE HIGH WILL
MOVE ACROSS OHIO AND PENNSYLVANIA WITH A RIDGE EXTENDING DOWN THE
EASTERN SIDE OF THE APPALACHIANS. WHAT BEGINS AS AN INVERTED TROUGH
OFF OF THE COAST OF FLORIDA DEVELOPS INTO A CLOSED LOW OFF OF THE
SC/GA COAST BY 12Z SATURDAY. MODELS DIFFER IN THE TRACK AND TIMING
OF THE LOW WITH THE GFS SLOWER AND FURTHER OFFSHORE AND THE ECMWF
QUICKER AND CLOSER TO THE COAST. THE QUICKER/CLOSER ECMWF CARRIES
THE MOST CONSEQUENCES FOR SENSIBLE WEATHER FOR CENTRAL NC.
THICKNESSES AND WETBULB ZERO TEMPERATURES SUGGEST THAT PRECIPITATION
COULD START OUT AS RAIN OR SNOW WITH THE BEST CHANCES FOR SNOW
FURTHER TO THE NORTH AND WEST...BUT ALSO FURTHER AWAY FROM THE MAIN
MOISTURE SOURCE WHICH WOULD CUT DOWN ANY ACCUMULATION/IMPACTS OF ANY
SNOW THAT DOES FALL INITIALLY. THE SLOWER GFS KEEPS THINGS DRY UNTIL
TEMPERATURES AND THICKNESS INCREASE ENOUGH TO THWART THE THREAT OF
ANY WINTER P-TYPE ISSUES. AFTER 12Z ANY FALLING PRECIP WILL BE
LIQUID WITH THE WETTER ECMWF CARRYING CLOSER TO A HALF AN INCH OF
PRECIP IN THE EAST AND 2 TENTHS OF AN INCH OF THE TRIANGLE WITH LESS
TO THE NORTHWEST. THE GFS ONLY CARRIES 1 TO 2 TENTHS OF AN INCH FROM
THE TRIANGLE EASTWARD. CONFIDENCE IS STILL BELOW AVERAGE ON WHICH OF
THESE SCENARIOS WILL OCCUR BUT WPC PREFERENCES CONTINUE TO BE
WEIGHTED TOWARD THE ECMWF AND THUS WILL INCLUDE THE CHANCE FOR RAIN
OR SNOW IN THE NW THROUGH MID MORNING...AND TRANSITION TO RAIN
THEREAFTER. ALL PRECIPITATION SHOULD EXIT THE EASTERN CWA JUST AFTER
00Z SUNDAY. HIGHS SATURDAY WILL REMAIN COOLER WITH WEDGE IN PLACE
INITIALLY AND THEN OVERCAST THROUGH THE DAY...LOW 40S NW TO NEAR 50
SE. LOWS SATURDAY NIGHT IN THE MID 30S. WITH LOW LEVEL SATURATION
HOLDING THROUGH THE OVERNIGHT HOURS...EXPECT SOME AREAS OF FOG
THROUGH SUNDAY MORNING.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 255 AM THURSDAY...
SATURDAY NIGHT...WIDESPREAD LOW LEVEL MOISTURE WILL MAINTAIN
OVERCAST SKIES ALONG WITH PATCHES OF DRIZZLE/FOG AND SOME LIGHT
RAIN. MIN TEMPS MID-UPPER 30S...AROUND 40 SE.
SUNDAY AND MONDAY: AS THE LOW EXITS TO THE NORTHEAST ON
SUNDAY...RESIDUAL LOW LEVEL MOISTURE WILL KEEP FOG AND LOW STRATUS
IN PLACE UNTIL AFTER SUNRISE BEFORE LIFTING TO 850 MB OR SO. DESPITE
THIS LIFTING THE BROKEN/OVERCAST CEILINGS SHOULD REMAIN IN PLACE
THROUGH THE DAY ON SUNDAY KEEPING HIGH TEMPERATURES DOWN. EXPECT
HIGHS ON SUNDAY IN THE UPPER 40S TO LOWER 50S. WHILE THE LOWER
CLOUDS WILL DISSIPATE BY SUNDAY NIGHT...UPPER LEVEL OVERCAST WILL
TAKE OVER AS A SHORTWAVE IN THE NORTHERN STREAM APPROACHES FROM THE
NW. DIFFERENCES IN THE 500 MB FLOW SHOW A SLIGHTLY DEEPER TROUGH IN
THE GFS VS A MORE ZONAL TRACK IN THE ECMWF. THIS ALLOWS THE NORTHERN
STREAM SHORTWAVE TO DIP INTO THE NORTHERN HALF OF OUR CWA ON THE GFS
NEAR 00Z MONDAY WHILE THE ECMWF IS LATER WITH THIS FEATURE AND
FURTHER TO THE NORTH...KEEPING CENTRAL NC DRY. EVEN IF PRECIPITATION
DOES MAKE IT INTO THE NORTHERN CWA...REINFORCING COLD AIR DOES NOT
ARRIVE UNTIL LATER AND ALL PRECIP SHOULD FALL AS LIQUID. WILL
INCLUDE SLIGHT CHANCES IN THE NORTH FROM 21Z SUNDAY THROUGH 3Z
MONDAY. ACCUMULATIONS GENERALLY LESS THAN A TENTH OF AN INCH.
TEMPERATURES MONDAY IN THE MID 40S. THICKNESSES SUGGEST TEMPERATURES
IN THE LOW TO MID 20S TUESDAY MORNING BUT SOME LATE ARRIVING UPPER
LEVEL CLOUDINESS COULD BUMP THESE UP TO MID TO UPPER 20S.
TUESDAY AND WEDNESDAY: VERY LOW CONFIDENCE FORECAST FOR TUESDAY AND
WEDNESDAY WILL BE DEPENDENT UPON THE EVOLUTION OF THE MERGING OF
PACIFIC AND GULF MOISTURE OVER TEXAS DURING THE DAY ON TUESDAY. A
SURFACE HIGH CROSSING THE GREAT LAKES ON TUESDAY WILL SET UP YET
ANOTHER HYBRID CAD SCENARIO OVER CENTRAL NC. AS THE AFOREMENTIONED
TEXAS MOISTURE MOVES NORTHEASTWARD IN THE SOUTHERN STREAM FLOW...IT
WILL MERGE WITH A THIRD SOURCE OF MOISTURE COMING OUT OF THE
SOUTHWEST ATLANTIC. THERE ARE LARGE DISPARITIES IN MODEL TIMING AT
THIS POINT WITH THE MOST LIKELY SCENARIO BETWEEN THE TWO
DETERMINISTIC MODELS. THE GFS HAS THE BETTER ISENTROPIC LIFT
BEGINNING AFTER 18Z TUESDAY AND PRECIPITATION BEGINNING BEFORE 00Z
WEDNESDAY. THE EC HOLDS OFF UNTIL CLOSER TO 12Z WEDNESDAY SO WE CAN
EXPECT PRECIP TO BEGIN SOMEWHERE IN THE EARLY MORNING WEDNESDAY
TIMEFRAME. TRACK OF THE LOW IS ALSO A LOW CONFIDENCE FORECAST AT
THIS POINT AND IT IS TOO EARLY TO TELL IF WE WILL HAVE ANY WINTER P-
TYPE ISSUES AT THIS POINT BUT IT IS CERTAINLY POSSIBLE IN THE
FAVORED NORTHWEST PIEDMONT WEDNESDAY MORNING. WILL MOST LIKELY LEAVE
OUT OF THE FORECAST AT THIS POINT AND WAIT FOR BETTER CONFIDENCE IN
SUBSEQUENT MODEL RUNS. REGARDLESS WE CAN EXPECT A WET DAY ON
WEDNESDAY. TEMPERATURES WILL REMAIN BELOW NORMAL FOR THIS TIMEFRAME
WITH HIGHS IN THE THE LOW TO MID 40S AND LOWS IN THE UPPER 20S TO
MID 30S.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 100 PM THURSDAY...
24-HR TAF PERIOD: VFR CONDITIONS WITH CEILINGS 12-18 KFT WILL
PREVAIL THROUGH 00Z THIS EVENING. A SHORTWAVE DISTURBANCE TRACKING
NORTHEAST THROUGH THE DEEP SOUTH THIS AFTERNOON WILL CROSS THE
CAROLINAS LATE THIS EVENING. A SHORT PERIOD (~3 HRS) OF MVFR
CEILINGS CANNOT BE RULED OUT IN THE 03-09Z TIME FRAME AT THE KFAY
TERMINAL...PERHAPS THE KRDU/KRWI TERMINALS AS WELL...AND HAVE
INCLUDED A TEMPO GROUP BETWEEN 04-08Z TO ACCOUNT FOR THIS
POSSIBILITY. NORTHERLY WINDS AT 5-10 KT WILL WEAKEN AND BECOME
LIGHT/VARIABLE THIS AFTERNOON...WITH LIGHT/VARIABLE WINDS PERSISTING
THROUGH THE DAY FRIDAY.
LOOKING AHEAD: VFR CONDITIONS AND LIGHT WINDS WILL PREVAIL ON
FRIDAY. SUB-VFR CONDITIONS AND PRECIPITATION WILL BE POSSIBLE DURING
THE DAY SATURDAY...LATE SUNDAY...AND AGAIN LATE MONDAY NIGHT THROUGH
TUESDAY AS A SERIES OF STORM SYSTEMS AFFECT THE CAROLINAS AND
VIRGINIA. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...MWS/VINCENT
SHORT TERM...ELLIS
LONG TERM...ELLIS
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
356 PM CST THU FEB 6 2014
.DISCUSSION...
THE UPPER LEVEL DISTURBANCE RESPONSIBLE FOR THE SNOW OVER THE
NORTHERN HALF OF THE CWA TODAY HAS MOVED QUICKLY OFF TO THE EAST
BUT THE NEXT ONE IS RIGHT ON ITS HEELS. THIS UPPER LEVEL SHORTWAVE
IS CURRENTLY LOCATED IN SOUTHERN CALIFORNIA AND WILL RAPIDLY
MOVE EAST AND MOVE ACROSS TEXAS DURING THE DAY TOMORROW. MOST
MODEL GUIDANCE DID NOT HANDLE THE STRENGTH OF THE FIRST SYSTEM
VERY WELL...BUT THE BETTER PERFORMERS WERE THE NAM AND RAP AND
THEREFORE WILL BE LEANING IN THEIR DIRECTION FOR THE FORECAST.
HOWEVER CONFIDENCE IN TOMORROWS FORECAST IS VERY LOW GIVEN OUR
FORECAST OF FREEZING AND FROZEN PRECIP IS NOT REALLY SUPPORTED IN
JUST ABOUT ALL OF THE MODEL GUIDANCE...BUT WE ARE WARY OF THE
STRENGTH OF THIS NEXT SYSTEM ALSO BEING UNDERESTIMATED.
ONCE AGAIN FORCING FOR ASCENT WILL BE STRONG BUT THE MAIN ISSUE IS
THE AMOUNT OF MOISTURE AVAILABLE FOR PRECIPITATION. THERE IS
ACTUALLY GOOD MODEL AGREEMENT THAT HIGH MOISTURE AND CONDITIONAL
SYMMETRIC INSTABILITY WILL BE AVAILABLE FOR SLANTWISE CONVECTION
AND BANDED SNOWFALL IN THE AREA OF THE ATMOSPHERE NEAR 500 TO
600MB OR NEAR 18-22 THOUSAND FEET. THIS BAND IS EXPECTED TO TRACK
ACROSS THE AREA ALONG AND NORTH OF INTERSTATE 20 DURING THE DAY
TOMORROW AND WILL LIKELY BE SEEN ON AREA RADARS. THE MODELS DIFFER
ON JUST HOW DRY THE AIRMASS WILL BE IN A LAYER NEAR 700 TO 850MB
OR ABOUT 5-10 THOUSAND FEET. WITH THE SOLE EXCEPTION OF THE ECMWF
AND ONE SREF MEMBER...ALL MODEL GUIDANCE INDICATES THE FALLING
SNOW WILL SUBLIMATE WHEN IT REACHES THIS DRY LAYER AND NOT REACH
THE SURFACE. HOWEVER AM NOT READY TO BUY INTO THIS JUST YET...AT
LEAST NOT UNTIL WE CAN SEE THE MOISTURE PROFILES FROM THE EVENING
RAOBS AT MAF AND DRT. OBVIOUSLY THERE WAS A LOT MORE MOISTURE
AVAILABLE IN THE AREA THAN WAS FORECAST TODAY AND IT IS LIKELY
STILL HANGING AROUND. SINCE MODEL SOUNDINGS FROM BOTH THE RAP AND
NAM INDICATE FAIRLY STEEP LAPSE RATES IN THE SNOW PRODUCING AREA
WHICH WOULD ENHANCE SNOWFALL INTENSITY...BELIEVE MORE SATURATION
WILL OCCUR FROM TOP DOWN THAN MODELS INDICATE. THUS WILL FORECAST
ANOTHER ROUND OF LIGHT SNOW ACROSS THE AREA NORTH OF I-20
TOMORROW...WITH POPS FOR MEASURABLE AMOUNTS OF SNOW AT 20 PERCENT
AND ACCUMULATIONS AT JUST A TENTH OF AN INCH OR LESS.
FARTHER SOUTH ACROSS CENTRAL TEXAS AND OUR SOUTHEAST ZONES...THE
SOUTHERLY WINDS AT 850MB WILL BE BRINGING WARMER AIR AND RICH GULF
MOISTURE NORTHWARD IN A HURRY AS THE SHORTWAVE APPROACHES. LOW
LEVEL ISENTROPIC CHARTS SHOW SUBTLE LIFT OCCURRING NEAR 925MB
WHICH WOULD CORRESPOND TO SOME LIGHT DRIZZLE DEVELOPING BEFORE DAY
BREAK. TEMPERATURES AT THIS TIME WOULD BE BELOW FREEZING.
PRECIPITATION WILL LIKELY INCREASE IN COVERAGE AND INTENSITY
ACROSS THE SOUTHEAST ZONES DURING THE AFTERNOON HOURS AS
ISENTROPIC LIFT RAMPS UP. HOWEVER TEMPERATURES MAY RISE ABOVE
FREEZING BEFORE THIS OCCURS. MODEL GUIDANCE MAY BE TOO QUICK TO
WARM TEMPS ABOVE FREEZING AS NORTH WINDS WILL HOLD IN THROUGH THE
MORNING HOURS AND THICK CLOUD COVER SHOULD KEEP TEMPS FROM RISING
MUCH IF ANY. HOWEVER WHEN THE PRECIP STARTS IT IS ASSOCIATED WITH
LOW LEVEL WARM ADVECTION...AND BELIEVE THAT TEMPS WILL TRY TO WARM
ABOVE FREEZING DURING THE AFTERNOON FROM SOUTHWEST TO NORTHEAST.
SO IT MAY START AS LIGHT FREEZING DRIZZLE/RAIN BUT SHOULD TRANSITION
TO REGULAR DRIZZLE OR RAIN DURING THE EVENT. AFTER A COUPLE OF
DAYS OF VERY COLD SUBFREEZING TEMPS...ROAD SURFACES ARE BELOW
FREEZING AND ANY FREEZING PRECIPITATION WOULD STICK ON IMPACT. DO
NOT EXPECT MUCH ACCUMULATION OF ICE AS PRECIPITATION INTENSITY
WILL BE LIGHT...BUT STILL THIS CAN BE A MAJOR TRAFFIC HAZARD
ESPECIALLY IF PEOPLE ARE NOT AWARE OF ICE ON ROADS. HAVE ISSUED A
WINTER WEATHER ADVISORY ACROSS THE SOUTHERN AND SOUTHEAST ZONES
FOR THE LIGHT FREEZING PRECIPITATION TO GET THE WORD OUT ABOUT
THE POTENTIAL TRAVEL ISSUES TOMORROW. THANKS TO WFO EWX/HGX/SHV
FOR THE COORDINATION.
THIS SYSTEM WILL CLEAR THE AREA FRIDAY NIGHT WITH SKIES CLEARING
SATURDAY. TEMPERATURES WILL REBOUND INTO THE 50S AND 60S BY
SATURDAY AFTERNOON AS DOWN SLOPE WESTERLY WINDS SPREAD ACROSS THE
REGION. THE WARM UP WILL BE SHORT LIVED AS ANOTHER FRONT SLIDES
SOUTH THROUGH THE AREA ON SUNDAY. HAVE SIDED WITH THE FASTER
ECMWF/GFS FORECASTS WITH THIS FRONT...AS IT IS LIKELY TO BE
SHALLOW AND WANT TO SPILL SOUTH DUE TO ITS HIGHER DENSITY.
THE EARLY NEXT WEEK FORECAST WILL FEATURE INCREASING CHANCES OF
PRECIPITATION. THE COLD AIR BEHIND THE SUNDAY FRONT WILL SETTLE IN
OVER THE AREA WITH HIGHS IN THE 40S AND LOWS IN THE 30S. AS
ANOTHER STRONG UPPER LEVEL SYSTEM MOVES IN FROM THE WEST...
ISENTROPIC LIFT WILL SET UP OVER THE TOP OF THE COLD DOME AND WE
SHOULD SEE CHANCES OF PRECIP STARTING MONDAY AND INCREASING INTO
TUESDAY. THE GFS AND CANADIAN ARE MOST AGGRESSIVE WITH QPF OUTPUT
WITH THIS SYSTEM BUT THE ECMWF CONTINUES TO BE RATHER TAME.
FURTHERMORE THE GFS/CANADIAN WOULD SUPPORT A WIDESPREAD WINTER MIX
EVENT FOR THE REGION...BUT AGAIN THE ECMWF DOES NOT SHOW THIS. FOR
NOW WE WILL CONTINUE TO ADVERTISE SOME WINTER PRECIP OVER THE
NORTHERN 2 ROWS OF COUNTIES TUESDAY AND TUESDAY NIGHT. THIS IS THE
REGION THAT IS MOST CLIMATOLOGICALLY FAVORED TO SEE WINTER PRECIP
AND WITH MODEL AGREEMENT LOW...IT MAKES SENSE TO KEEP THE WINTER
MIX UP THERE AND SPREAD IT SOUTH SHOULD THE ECMWF COME IN LINE
WITH THE OTHER GUIDANCE AND CONFIDENCE INCREASES.
TR.92
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 21 34 29 57 34 / 10 20 10 0 0
WACO, TX 23 35 29 64 38 / 20 20 10 0 0
PARIS, TX 21 33 25 53 33 / 10 20 20 0 0
DENTON, TX 19 33 26 56 30 / 10 20 10 0 0
MCKINNEY, TX 21 33 26 55 31 / 10 20 10 0 0
DALLAS, TX 22 34 30 57 37 / 10 20 10 0 0
TERRELL, TX 23 34 27 57 34 / 10 20 10 0 0
CORSICANA, TX 24 34 30 60 38 / 10 30 10 0 0
TEMPLE, TX 24 35 29 65 38 / 20 30 10 0 0
MINERAL WELLS, TX 19 37 26 60 31 / 10 20 10 0 0
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 5 AM TO 3 PM CST FRIDAY FOR
TXZ156>160-174-175.
WINTER WEATHER ADVISORY FROM 9 AM TO 6 PM CST FRIDAY FOR TXZ122-
135-146>148-161-162.
&&
$$
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1154 AM CST THU FEB 6 2014
.AVIATION...
MVFR CIGS ACROSS THE RIO GRANDE VALLEY WILL CONTINUE TO LIFT THIS
MORNING. OTHERWISE...VFR CONDITIONS WILL PREVAIL THROUGH MUCH OF
THE TAF PERIOD AS RIDGING PREVAILS AT THE SFC. AN UPPER LEVEL
SYSTEM WILL MOVE ACROSS THE AREA TONIGHT ENABLING A CHANCE FOR
PRECIPITATION. WITH THE COLD AIRMASS REMAINING AT THE SFC...A MIX
OF -FZDZ/-IP/-SN WILL BE POSSIBLE DURING THE OVERNIGHT HOURS.MODELS
CONTINUE TO SUGGEST ANY FROZEN ACCUMULATIONS WILL BE LIGHT. CIGS
ARE EXPECTED TO LOWER TO MVFR FROM WEST TO EAST ACROSS THE REGION
FRIDAY MORNING. MODELS ARE THEN UNDECIDED WHETHER TO KEEP BASES AT
MVFR LEVELS...LOWER TO IFR...OR RAISE TO VFR DURING THE LATE
MORNING/EARLY AFTERNOON HOURS. SFC WINDS WILL BE N-NERLY 10 TO 15
KTS THROUGH THIS EVENING. WINDS AT KDRT WILL GRADUALLY VEER TO THE
SE BY EARLY FRIDAY MORNING.
&&
.PREV DISCUSSION... /ISSUED 1131 AM CST THU FEB 6 2014/
UPDATE...
THE WINTER WEATHER ADVISORY HAS BEEN ALLOWED TO EXPIRE. SPOTTER
REPORTS AND RADAR DATA CONFIRM SOME VERY LIGHT SNOW IS FALLING
ACROSS PORTIONS OF THE WESTERN HILL COUNTRY. SOME OF THIS ACTIVITY
MAY BRIEFLY MOVE INTO THE I-35 CORRIDOR. HOWEVER... WE ARE NOT
EXPECTING ANY ACCUMULATION. HIGH TEMPERATURES HAVE BEEN LOWERED
ONCE AGAIN AS CLOUD COVER AND COLD AIR ADVECTION WILL REMAIN
INTACT TODAY.
PREV DISCUSSION... /ISSUED 942 AM CST THU FEB 6 2014/
UPDATE...
WE HAVE LOWERED TODAY/S HIGH TEMPERATURES BY A FEW DEGREES ACROSS
MOST OF THE REGION. THE LATEST RUC13 AND SREF MODEL DATA SUGGESTS
HIGHS WILL REMAIN IN THE 30S ACROSS MOST AREAS...WITH TEMPS
STRUGGLING TO REACH FREEZING OVER THE HILL COUNTRY. HIGHS ALONG
THE I-35 CORRIDOR WILL STRUGGLE TO REACH THE MID 30S. NO CHANGES
TO THE WINTER WEATHER ADVISORY JUST YET AS THE LATEST RADAR DATA
CONTINUES TO SHOW SOME LIGHT ECHOES ACROSS THE HILL COUNTRY SLOWLY
MOVING INTO THE I-35 CORRIDOR. WE COULD SEE SOME LIGHT SNOW OR
GRAUPEL FROM THIS ACTIVITY. GIVEN THE LIGHT RADAR RETURNS...WOULD
NOT EXPECT ANY SIGNIFICANT ACCUMULATIONS FROM THIS ACTIVITY.
PREV DISCUSSION... /ISSUED 547 AM CST THU FEB 6 2014/
AVIATION...
VFR CONDITIONS AT I-35 SITES WITH MVFR AT KDRT. EXPECT THIS TREND
TO CONTINUE WITH COLD HIGH PRESSURE IN CONTROL OVER THE REGION.
ALL SLEET AND LIGHT SNOW SHOULD BE OUT OF THE AREA BY 14Z. CLOUDS
SHOULD REMAIN IN THE 4-6 THOUSAND FOOT RANGE THIS AFTERNOON.
CEILINGS WILL LOWER TO 2-4 THOUSAND FEET AFTER 01Z FRIDAY. AFTER
08Z TONIGHT WILL SEE ANOTHER UPPER LEVEL SYSTEM MOVE ACROSS WITH
LOW CHANCES FOR LIGHT FREEZING DRIZZLE. CURRENTLY FEEL THAT ANY
ACCUMULATIONS WOULD BE MINOR. NORTHERLY WINDS WILL DECREASE TO 10
TO 15 KNOTS THIS MORNING AND NEAR 10 KNOTS THIS AFTERNOON AND
OVERNIGHT.
PREV DISCUSSION... /ISSUED 525 AM CST THU FEB 6 2014/
UPDATE...
HAVE ISSUED A WINTER WEATHER ADVISORY FOR A BAND OF SLEET AND SNOW
FROM NORTHERN SAN ANTONIO ACROSS THE NEW BRAUNFELS AND SAN MARCOS
AREAS...THEN EAST TO LA GRANGE AND LEXINGTON. SLEET AND SNOW
ACCUMULATIONS UP TO ONE HALF INCH ARE POSSIBLE. THE BAND WILL MOVE
EAST BY 11 AM.
PREV DISCUSSION... /ISSUED 424 AM CST THU FEB 6 2014/
UPDATE...
ADDED MENTION OF SLEET FOR A BAND FROM HONDO TO SAN ANTONIO TO
BASTROP TO GIDDINGS. A DUSTING MAY BE POSSIBLE WITH THIS BAND.
PREV DISCUSSION... /ISSUED 341 AM CST THU FEB 6 2014/
SHORT TERM (TODAY THROUGH FRIDAY)...
COLD ADVECTION CONTINUES ACROSS SOUTH CENTRAL TEXAS EARLY THIS
MORNING AS AN UPPER LEVEL TROUGH MOVES ACROSS THE BIG BEND REGION.
ISENTROPIC LIFT ASSOCIATED WITH THIS TROUGH WILL GENERATE VERY
LIGHT PRECIPITATION. CURRENT AND FORECAST SOUNDING DATA SHOW THAT
SNOW FLURRIES ARE THE LIKELY PRECIPITATION TYPE. NO ACCUMULATION
IS EXPECTED DUE TO A VERY DRY LOWER LEVEL AIRMASS. THE TROUGH WILL
MOVE NORTHEAST OF OUR AREA BY MIDDAY ENDING THE FLURRIES AS LIFT
ENDS. ANOTHER UPPER LEVEL TROUGH CURRENTLY SEEN APPROACHING THE
CALIFORNIA COAST WILL MOVE ACROSS TEXAS ON FRIDAY. ISENTROPIC LIFT
WILL DEVELOP LATE TONIGHT. A WARMER AND MORE MOIST AIRMASS ALOFT
WILL CREATE DRIZZLE OR FREEZING DRIZZLE. EVEN THOUGH MORE MOISTURE
WILL BE AVAILABLE...LITTLE OR NO ICE ACCUMULATION IS EXPECTED.
HOWEVER...A SLIGHTLY STRONGER SYSTEM WITH SLIGHTLY DEEPER MOISTURE
COULD PRODUCE LIGHT ICING ON BRIDGES...OVERPASSES AND OTHER
ELEVATED ROADS. SO...STAY TUNED FOR THE LATEST DEVELOPMENTS ON
THIS WEATHER EVENT. ISENTROPIC LIFT SLOWLY WANES WITH DRIZZLE
ENDING BY LATE FRIDAY EVENING. CLOUD COVER WILL MAKE TEMPERATURES
STRUGGLE TO REACH 40 MOST AREAS TODAY AND FRIDAY. AVERAGE HIGHS
ARE IN THE LOWER TO MID 60S.
LONG TERM (FRIDAY NIGHT THROUGH WEDNESDAY)...
SOUTHWESTERLY WINDS DEVELOP ON SATURDAY AS THE SURFACE HIGH MOVES
AWAY LEADING TO A WARM DAY WITH HIGHS NEAR OR JUST ABOVE AVERAGE.
THE MODELS HAVE BECOME MORE DISAGREEABLE FOR SUNDAY AND MONDAY.
THE GFS BRINGS A WEAK BACKDOOR COLD FRONT INTO OUR AREA SUNDAY AND
LIFTS IT BACK NORTH MONDAY WITH A STRONGER COLD FRONT TUESDAY
WHILE THE ECMWF BRINGS A MODERATELY COLD FRONT THROUGH SUNDAY
NIGHT WITH A STRONGER PUSH OF COLD AIR TUESDAY. BOTH MODELS SHOW
AN UPPER LEVEL TROUGH MOVING ACROSS TEXAS LATE TUESDAY INTO
TUESDAY NIGHT. FOR NOW...WILL SIDE WITH THE GFS ON THE FRONT.
WARM ADVECTION SHOWERS ARE POSSIBLE MONDAY INTO MONDAY NIGHT WITH
A SLIGHTLY BETTER CHANCE OF SHOWERS WITH THE UPPER LEVEL TROUGH
TUESDAY INTO TUESDAY NIGHT. COLD AND DRY AGAIN FOR WEDNESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 34 26 41 35 67 / 10 10 20 10 -
AUSTIN BERGSTROM INTL AIRPORT 34 24 39 33 66 / 10 10 20 10 -
NEW BRAUNFELS MUNI AIRPORT 35 27 38 33 68 / 20 10 20 10 -
BURNET MUNI AIRPORT 33 23 39 31 65 / 10 10 20 10 -
DEL RIO INTL AIRPORT 40 30 47 36 71 / 10 - - - -
GEORGETOWN MUNI AIRPORT 34 23 39 32 63 / 10 10 20 10 -
HONDO MUNI AIRPORT 37 28 42 34 70 / 10 10 20 10 -
SAN MARCOS MUNI AIRPORT 35 26 38 33 67 / 20 10 20 10 -
LA GRANGE - FAYETTE REGIONAL 36 29 39 35 63 / 20 10 20 20 10
SAN ANTONIO INTL AIRPORT 35 29 41 35 69 / 20 10 20 10 -
STINSON MUNI AIRPORT 36 30 40 34 69 / 10 10 20 10 -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...25
SYNOPTIC/GRIDS...24
PUBLIC SERVICE/DATA COLLECTION...33
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
1131 AM CST THU FEB 6 2014
.UPDATE...
THE WINTER WEATHER ADVISORY HAS BEEN ALLOWED TO EXPIRE. SPOTTER
REPORTS AND RADAR DATA CONFIRM SOME VERY LIGHT SNOW IS FALLING
ACROSS PORTIONS OF THE WESTERN HILL COUNTRY. SOME OF THIS ACTIVITY
MAY BRIEFLY MOVE INTO THE I-35 CORRIDOR. HOWEVER... WE ARE NOT
EXPECTING ANY ACCUMULATION. HIGH TEMPERATURES HAVE BEEN LOWERED
ONCE AGAIN AS CLOUD COVER AND COLD AIR ADVECTION WILL REMAIN
INTACT TODAY.
&&
.PREV DISCUSSION... /ISSUED 942 AM CST THU FEB 6 2014/
UPDATE...
WE HAVE LOWERED TODAY/S HIGH TEMPERATURES BY A FEW DEGREES ACROSS
MOST OF THE REGION. THE LATEST RUC13 AND SREF MODEL DATA SUGGESTS
HIGHS WILL REMAIN IN THE 30S ACROSS MOST AREAS...WITH TEMPS
STRUGGLING TO REACH FREEZING OVER THE HILL COUNTRY. HIGHS ALONG
THE I-35 CORRIDOR WILL STRUGGLE TO REACH THE MID 30S. NO CHANGES
TO THE WINTER WEATHER ADVISORY JUST YET AS THE LATEST RADAR DATA
CONTINUES TO SHOW SOME LIGHT ECHOES ACROSS THE HILL COUNTRY SLOWLY
MOVING INTO THE I-35 CORRIDOR. WE COULD SEE SOME LIGHT SNOW OR
GRAUPEL FROM THIS ACTIVITY. GIVEN THE LIGHT RADAR RETURNS...WOULD
NOT EXPECT ANY SIGNIFICANT ACCUMULATIONS FROM THIS ACTIVITY.
PREV DISCUSSION... /ISSUED 547 AM CST THU FEB 6 2014/
AVIATION...
VFR CONDITIONS AT I-35 SITES WITH MVFR AT KDRT. EXPECT THIS TREND
TO CONTINUE WITH COLD HIGH PRESSURE IN CONTROL OVER THE REGION.
ALL SLEET AND LIGHT SNOW SHOULD BE OUT OF THE AREA BY 14Z. CLOUDS
SHOULD REMAIN IN THE 4-6 THOUSAND FOOT RANGE THIS AFTERNOON.
CEILINGS WILL LOWER TO 2-4 THOUSAND FEET AFTER 01Z FRIDAY. AFTER
08Z TONIGHT WILL SEE ANOTHER UPPER LEVEL SYSTEM MOVE ACROSS WITH
LOW CHANCES FOR LIGHT FREEZING DRIZZLE. CURRENTLY FEEL THAT ANY
ACCUMULATIONS WOULD BE MINOR. NORTHERLY WINDS WILL DECREASE TO 10
TO 15 KNOTS THIS MORNING AND NEAR 10 KNOTS THIS AFTERNOON AND
OVERNIGHT.
PREV DISCUSSION... /ISSUED 525 AM CST THU FEB 6 2014/
UPDATE...
HAVE ISSUED A WINTER WEATHER ADVISORY FOR A BAND OF SLEET AND SNOW
FROM NORTHERN SAN ANTONIO ACROSS THE NEW BRAUNFELS AND SAN MARCOS
AREAS...THEN EAST TO LA GRANGE AND LEXINGTON. SLEET AND SNOW
ACCUMULATIONS UP TO ONE HALF INCH ARE POSSIBLE. THE BAND WILL MOVE
EAST BY 11 AM.
PREV DISCUSSION... /ISSUED 424 AM CST THU FEB 6 2014/
UPDATE...
ADDED MENTION OF SLEET FOR A BAND FROM HONDO TO SAN ANTONIO TO
BASTROP TO GIDDINGS. A DUSTING MAY BE POSSIBLE WITH THIS BAND.
PREV DISCUSSION... /ISSUED 341 AM CST THU FEB 6 2014/
SHORT TERM (TODAY THROUGH FRIDAY)...
COLD ADVECTION CONTINUES ACROSS SOUTH CENTRAL TEXAS EARLY THIS
MORNING AS AN UPPER LEVEL TROUGH MOVES ACROSS THE BIG BEND REGION.
ISENTROPIC LIFT ASSOCIATED WITH THIS TROUGH WILL GENERATE VERY
LIGHT PRECIPITATION. CURRENT AND FORECAST SOUNDING DATA SHOW THAT
SNOW FLURRIES ARE THE LIKELY PRECIPITATION TYPE. NO ACCUMULATION
IS EXPECTED DUE TO A VERY DRY LOWER LEVEL AIRMASS. THE TROUGH WILL
MOVE NORTHEAST OF OUR AREA BY MIDDAY ENDING THE FLURRIES AS LIFT
ENDS. ANOTHER UPPER LEVEL TROUGH CURRENTLY SEEN APPROACHING THE
CALIFORNIA COAST WILL MOVE ACROSS TEXAS ON FRIDAY. ISENTROPIC LIFT
WILL DEVELOP LATE TONIGHT. A WARMER AND MORE MOIST AIRMASS ALOFT
WILL CREATE DRIZZLE OR FREEZING DRIZZLE. EVEN THOUGH MORE MOISTURE
WILL BE AVAILABLE...LITTLE OR NO ICE ACCUMULATION IS EXPECTED.
HOWEVER...A SLIGHTLY STRONGER SYSTEM WITH SLIGHTLY DEEPER MOISTURE
COULD PRODUCE LIGHT ICING ON BRIDGES...OVERPASSES AND OTHER
ELEVATED ROADS. SO...STAY TUNED FOR THE LATEST DEVELOPMENTS ON
THIS WEATHER EVENT. ISENTROPIC LIFT SLOWLY WANES WITH DRIZZLE
ENDING BY LATE FRIDAY EVENING. CLOUD COVER WILL MAKE TEMPERATURES
STRUGGLE TO REACH 40 MOST AREAS TODAY AND FRIDAY. AVERAGE HIGHS
ARE IN THE LOWER TO MID 60S.
LONG TERM (FRIDAY NIGHT THROUGH WEDNESDAY)...
SOUTHWESTERLY WINDS DEVELOP ON SATURDAY AS THE SURFACE HIGH MOVES
AWAY LEADING TO A WARM DAY WITH HIGHS NEAR OR JUST ABOVE AVERAGE.
THE MODELS HAVE BECOME MORE DISAGREEABLE FOR SUNDAY AND MONDAY.
THE GFS BRINGS A WEAK BACKDOOR COLD FRONT INTO OUR AREA SUNDAY AND
LIFTS IT BACK NORTH MONDAY WITH A STRONGER COLD FRONT TUESDAY
WHILE THE ECMWF BRINGS A MODERATELY COLD FRONT THROUGH SUNDAY
NIGHT WITH A STRONGER PUSH OF COLD AIR TUESDAY. BOTH MODELS SHOW
AN UPPER LEVEL TROUGH MOVING ACROSS TEXAS LATE TUESDAY INTO
TUESDAY NIGHT. FOR NOW...WILL SIDE WITH THE GFS ON THE FRONT.
WARM ADVECTION SHOWERS ARE POSSIBLE MONDAY INTO MONDAY NIGHT WITH
A SLIGHTLY BETTER CHANCE OF SHOWERS WITH THE UPPER LEVEL TROUGH
TUESDAY INTO TUESDAY NIGHT. COLD AND DRY AGAIN FOR WEDNESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 34 26 41 35 67 / 10 10 20 10 -
AUSTIN BERGSTROM INTL AIRPORT 34 24 39 33 66 / 10 10 20 10 -
NEW BRAUNFELS MUNI AIRPORT 35 27 38 33 68 / 20 10 20 10 -
BURNET MUNI AIRPORT 33 23 39 31 65 / 10 10 20 10 -
DEL RIO INTL AIRPORT 40 30 47 36 71 / 10 - - - -
GEORGETOWN MUNI AIRPORT 34 23 39 32 63 / 10 10 20 10 -
HONDO MUNI AIRPORT 37 28 42 34 70 / 10 10 20 10 -
SAN MARCOS MUNI AIRPORT 35 26 38 33 67 / 20 10 20 10 -
LA GRANGE - FAYETTE REGIONAL 36 29 39 35 63 / 20 10 20 20 10
SAN ANTONIO INTL AIRPORT 35 29 41 35 69 / 20 10 20 10 -
STINSON MUNI AIRPORT 36 30 40 34 69 / 10 10 20 10 -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...25
SYNOPTIC/GRIDS...24
PUBLIC SERVICE/DATA COLLECTION...33