Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 11/23/14
AREA FORECAST DISCUSSION...UPDATED
NWS LITTLE ROCK AR
522 PM CST SAT NOV 22 2014
.AVIATION...
LOW PRESSURE OVER CENTRAL TEXAS WILL CONTINUE TO LIFT
NORTHEASTWARD OVER THE NEXT 24 HOURS. CEILINGS AND VISBYS WILL
GRADUALLY DIMINISH LATER TONIGHT...WITH PRECIPITATION
OVERSPREADING THE AREA. THERE WILL BE SOME ISOLATED THUNDERSTORMS
AS WELL. CONDITIONS WILL BECOME WIDESPREAD IFR BY LATE TONIGHT.
TAFS OUT ALREADY.
&&
.PREV DISCUSSION... /ISSUED 258 PM CST SAT NOV 22 2014/
SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT
WARM FNT WAS SITUATED WELL TO THE N OF AR THIS AFTN...WITH S/SELY
WINDS NOTED ACRS THE FA. WIDESPREAD SHRA/ISOLD TSRA HAS CONTD TO
AFFECT MUCH OF W-CNTRL AND NRN AR AS ANOTHER UPR LVL IMPULSE LIFTS
THRU THE REGION. PARTLY CLOUDY SKIES WERE NOTED OVR THE SERN HALF OF
THE AREA....WITH MID AFTN TEMPS IN THE 60S TO ARND 70.
THE PRIMARY WX MAKER OVR THE NEXT 24 TO 36 HRS WL BE THE MAIN UPR
LVL STORM SYS THAT WL CONT TO TRACK EWD INTO CNTRL TX TNGT AND
EVENTUALLY LIFT NEWD THRU AR ON SUN. SHRA/EMBEDDED TSRA WL BCM MORE
WIDESPREAD FM THE SW OVERNIGHT AND CONT ON SUN.
ONE FCST ISSUE CONTS TO BE THE ONSET/PROGRESS WITH THE MAIN WAVE OF
RAINFALL LATER TNGT AND SUN. THE HRRR MODEL HAS STAYED CONSISTENT
TODAY INDCG THE BULK OF THE RAIN WL NOT AFFECT THE FA FM THE SW
UNTIL AFT MIDNIGHT TNGT AND HAVE TRENDED POPS TOWARD THIS SOLUTION.
EXPECT WIDESPREAD SHRA/ISOLD TSRA SUN MRNG...SLOLY DCRSG FM THE SW
SUN AFTN AND EVENING AS THE STORM SYS LIFTS OUT OF THE AREA. LEFT
SOME SMALL RAIN CHCS IN FOR NRN AR SUN NGT AS THE MAIN UPR LVL TROF
SWINGS THRU THE AREA.
BREEZY WLY WINDS WL BRING COOLER AND MUCH DRIER AIR BACK TO THE MID
SOUTH FOR THE REST OF THE PD. SECONDARY CDFNT WL PASS THRU THE AREA
ON TUE...WITH A REINFORCING SHOT OF COOLER AIR.
LONG TERM...WEDNESDAY THROUGH SATURDAY
NEXT WEAK COLD FRONT IS DUE ON WEDNESDAY. AT THIS POINT...MOISTURE
LOOKS TOO LIMITED TO INCLUDE ANY POPS. ANOTHER WEAK FRONT IN THE
THURSDAY/FRIDAY TIME FRAME. WITH THESE REINFORCING SHOTS OF COOL
AIR...TEMPERATURES WILL REMAIN QUITE A BIT BELOW NORMAL THROUGH THE
END OF THE WEEK. JUST BEYOND THIS FORECAST PERIOD...THERE SHOULD BE
MORE CLOUDS AND PROBABLY SOME LOW POPS FOR AT LEAST A COUPLE OF DAYS.
&&
.LZK WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AVIATION...57
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
902 PM MST SAT NOV 22 2014
.UPDATE...
ISSUED AT 858 PM MST SAT NOV 22 2014
A QUICK SHOT OF SNOWFALL AHEAD OF THE FRONT CAUSED A QUICK INCH OF
SNOW IN THE TOWN OF VERNAL AND SURROUNDING COMMUNITIES. DO NOT
ANTICIPATE MUCH MORE ACCUMULATION BUT DECIDED TO ISSUE ADVISORY
FOR THAT ZONE AS LOCAL DISPATCH REPORTS NUMEROUS CAR ACCIDENTS
ACROSS THE AREA. THINK IT BETTER TO GET THE WORD OUT FOR THOSE
INDIVIDUALS CONSIDERING DRIVING TONIGHT. NO OTHER CHANGES TO
CURRENT WINTER HIGHLIGHTS.
UPDATE ISSUED AT 725 PM MST SAT NOV 22 2014
THE SURFACE COLD FRONT HAS ENTERED WRN WY AND IS DRAPED DOWN TO
THE SE THROUGH CENTRAL UTAH. A FEW LIGHTNING STRIKES ARE STILL
BEING OBSERVED ALONG THE FRONT BUT THE NUMBER HAS DROPPED
DRAMATICALLY IN THE LAST FEW HOURS. THIS TREND WILL CONTINUE
THROUGH THE EVENING HOURS. THE RADAR MOSAIC SHOWS WIDESPREAD
PRECIP ACROSS THE CWA THIS EVENING WITH MANY AREAS REPORTING...OR
HAVING REPORTED...SHOWERS OVER THE LAST FEW HOURS. THIS WILL
CONTINUE AS THE FRONT APPROACHES. BOTH THE HRRR AND NAM12
INITIALIZED WELL AND BRING THE FRONT THROUGH NRN AREAS BY ABOUT
MIDNIGHT...REACHING THE GRAND VALLEY AROUND 0300L AND THEN THE SAN
JUANS BY DAYBREAK. SNOTELS REPORTING A FEW INCHES OF SNOW FOR THE
PARK/GORE RANGES WHILE ONE SNOTEL IN ERN UT REPORTING AROUND 6
INCHES. CURRENT FORECAST CAPTURING CURRENT WEATHER WELL SO MADE NO
CHANGES.
&&
.SHORT TERM...(TONIGHT THROUGH SUNDAY NIGHT)
ISSUED AT 318 PM MST SAT NOV 22 2014
SATELLITE AND ANALYSIS SHOWS THE COLD FRONT OVER NW UT AND
NORTHERN NV ASSOCIATED WITH THE STORM SYSTEM TO MOVE THROUGH THE
AREA TONIGHT. RADAR SHOWS AN AREA OF LOWER CLOUDS AND SCATTERED
SHOWERS MOVING THROUGH CENTRAL CO WITH SOME SHOWERS REPORTED ALONG
INTERSTATE 70 EAST OF GRAND JUNCTION. THE FRONT SHOULD MOVE
THROUGH NORTHWEST CO BY ABOUT MIDNIGHT AND THEN DRAG THROUGH THE
REST OF THE AREA OVERNIGHT. THE BEST COLD ADVECTION AND DYNAMIC
SUPPORT SHOULD MOVE THROUGH BETWEEN ABOUT 04Z AND 12Z. FOLLOWING
FRONTAL PASSAGE...FROM NW TO SE ACROSS THE AREA TONIGHT...WINDS AT
MTN TOP LEVEL WILL SHIFT TO THE NW AND BECOME MORE NORTHERLY WITH
TIME SUNDAY. THIS WILL SHIFT THE FOCUS OF BEST SNOWFALL FROM WEST
TO NNW FACING SLOPES.
MOISTURE STEADILY ERODES SUNDAY...AS FORECAST SOUNDINGS SHOW ONLY
A SHALLOW SURFACE-BASED SATURATED LAYER REMAINING OVER THE
NORTHERN HALF OF THE AREA. TEMPERATURES IN THIS LAYER ARE IN THE
FAVORABLE RANGE FOR DENDRITIC GROWTH WITH A STRONG LAPSE RATE. IN
THESE CONDITIONS OROGRAPHIC SNOWFALL SHOULD CONTINUE IN THE
NORTHERN AND CENTRAL MOUNTAINS...BUT DIMINISH OVER THE VALLEYS AND
PLATEAUS. THE SOUNDING OVER THE SOUTHERN HALF OF THE AREA BECOMES
EVEN DRIER SO THERE A PAUSE IN SNOWFALL SHOULD OCCUR OVER MUCH OF
THE SOUTHERN MOUNTAINS SUNDAY NIGHT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 318 PM MST SAT NOV 22 2014
MONDAY IN NW FLOW A STRONG COLD DISTURBANCE DROPS THROUGH THE
REGION. AN ASSOCIATED -33C COLD CORE STEEPENS LAPSE RATES.
MOISTURE IS LIMITED AND WITH THE JET DIGGING THROUGH UTAH
DYNAMICS ARE NOT OVERLY IMPRESSIVE. BUT COLD ADVECTION...NW
OROGRAPHICS...AND THE SNOW PRODUCTION LAYER AT MTN TOP LEVEL
(-12C AT 700MB) WILL COMBINE TO PRODUCE ANOTHER ROUND OF
SIGNIFICANT SNOWFALL OVER THE NORTHERN AND CENTRAL MTNS. THE
CURRENT HIGHLIGHTS FOR MONDAY LOOK ON TRACK...THOUGH THE NW SAN
JUAN MTNS MAY NEED AN ADVISORY. HAVE RAISED POPS THERE. THE SNOW
SHOULD BE QUITE DRY FOR NOVEMBER...IN THE 20:1 RANGE.
SNOWFALL FINALLY DIMINISHES THROUGH MONDAY NIGHT AS THE TROUGH AND
ASSOCIATED JET SLIDES SE. THE MOIST MARGINALLY UNSTABLE LAYER
SHRINKS TOP DOWN INTO TUESDAY SO SOME SCATTERED SNOW SHOWERS ARE
EXPECTED IN THE EASTERN MTNS THROUGH TUESDAY AFTERNOON WITH LITTLE
ACCUMULATION EXPECTED.
TUESDAY NIGHT THROUGH SATURDAY...THE WEST COAST RIDGE SLOWLY
PROGRESSES INLAND BRINGING DRY CONDITIONS AND PERSISTENT VALLEY
INVERSIONS. UNDERCUT GUIDANCE TEMPERATURES INTO FRIDAY AS THE
RIDGE BUILDS OVER THE FORECAST AREA AND DEAMPLIFIES. THIS PROMISES
DRY CONDITIONS FOR THANKSGIVING. SATURDAY MODEL TIMING BREAKS
SOMEWHAT WITH THE GFS DIGGING THE NEXT TROUGH INTO WA-OR WHILE THE
EC HOLDS IT OFFSHORE. IF THE GFS VERIFIES WE MAY HAVE SHOWERS OVER
THE NORTH BY SUNDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY AFTERNOON)
ISSUED AT 355 PM MST SAT NOV 22 2014
A COLD FRONT WILL CONTINUE MOVING THROUGH THE AREA TONIGHT...
FOLLOWED BY A MOIST NORTHWEST FLOW THROUGH SUNDAY. SNOW IN THE
MOUNTAINS AND A MIX OF RAIN AND SNOW AT LOWER ELEVATIONS WILL
SPREAD FROM NORTHWEST TO SOUTHEAST TONIGHT...CHANGING TO SNOW AT
ALL ELEVATIONS BY ABOUT MIDNIGHT. SNOWFALL IN THE MOUNTAINS WILL
BE HEAVY AT TIMES...AND MOST MOUNTAINS WILL BECOME OBSCURED BY
MIDNIGHT. SNOW LEVELS WILL START AT ABOUT 6500 FEET THIS EVENING
THEN STEADILY DECREASE TO VALLEY BOTTOMS OVERNIGHT AND SUNDAY.
TAF SITES NORTH OF THE SAN JUAN MOUNTAINS WILL EXPERIENCE SHOWERS
THIS EVENING WITH OCCASIONAL IFR CIGS AND VSBYS AFFECTING
KASE...KEGE...KRIL AFTER 03Z AND CONTINUING OVERNIGHT AND SUNDAY.
MVFR CIGS AND VSBYS ARE EXPECTED AT ALL THE OTHER TAF SITES FROM
ABOUT 06Z THROUGH ABOUT 18Z SUNDAY...THEN GRADUALLY DECREASING.
ALSO...STRONG WEST TO NORTHWEST WINDS WILL CAUSE AREAS OF BLOWING
SNOW IN THE MOUNTAINS AND EXPOSED AREAS.
IN ADDITION...STRONG WINDS AT MOUNTAINTOP LEVEL WILL RESULT IN
MODERATE TO STRONG TURBULENCE...ESPECIALLY IN THE LEE OF HIGHER
TERRAIN.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER WEATHER ADVISORY UNTIL 6 AM MST SUNDAY FOR COZ002-003.
WINTER WEATHER ADVISORY UNTIL 3 PM MST SUNDAY FOR COZ007-008-011-
014-018-019.
WINTER STORM WARNING UNTIL 6 PM MST MONDAY FOR COZ004-005-009-
010-012-013.
UT...WINTER WEATHER ADVISORY UNTIL 5 AM MST SUNDAY FOR UTZ024.
WINTER WEATHER ADVISORY UNTIL 6 AM MST SUNDAY FOR UTZ023.
&&
$$
UPDATE...TGR
SHORT TERM...CC
LONG TERM...JOE
AVIATION...CC
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
736 PM MST SAT NOV 22 2014
.UPDATE...
ISSUED AT 725 PM MST SAT NOV 22 2014
THE SURFACE COLD FRONT HAS ENTERED WRN WY AND IS DRAPED DOWN TO
THE SE THROUGH CENTRAL UTAH. A FEW LIGHTNING STRIKES ARE STILL
BEING OBSERVED ALONG THE FRONT BUT THE NUMBER HAS DROPPED
DRAMATICALLY IN THE LAST FEW HOURS. THIS TREND WILL CONTINUE
THROUGH THE EVENING HOURS. THE RADAR MOSAIC SHOWS WIDESPREAD
PRECIP ACROSS THE CWA THIS EVENING WITH MANY AREAS REPORTING...OR
HAVING REPORTED...SHOWERS OVER THE LAST FEW HOURS. THIS WILL
CONTINUE AS THE FRONT APPROACHES. BOTH THE HRRR AND NAM12
INITIALIZED WELL AND BRING THE FRONT THROUGH NRN AREAS BY ABOUT
MIDNIGHT...REACHING THE GRAND VALLEY AROUND 0300L AND THEN THE SAN
JUANS BY DAYBREAK. SNOTELS REPORTING A FEW INCHES OF SNOW FOR THE
PARK/GORE RANGES WHILE ONE SNOTEL IN ERN UT REPORTING AROUND 6
INCHES. CURRENT FORECAST CAPTURING CURRENT WEATHER WELL SO MADE NO
CHANGES.
&&
.SHORT TERM...(TONIGHT THROUGH SUNDAY NIGHT)
ISSUED AT 318 PM MST SAT NOV 22 2014
SATELLITE AND ANALYSIS SHOWS THE COLD FRONT OVER NW UT AND
NORTHERN NV ASSOCIATED WITH THE STORM SYSTEM TO MOVE THROUGH THE
AREA TONIGHT. RADAR SHOWS AN AREA OF LOWER CLOUDS AND SCATTERED
SHOWERS MOVING THROUGH CENTRAL CO WITH SOME SHOWERS REPORTED ALONG
INTERSTATE 70 EAST OF GRAND JUNCTION. THE FRONT SHOULD MOVE
THROUGH NORTHWEST CO BY ABOUT MIDNIGHT AND THEN DRAG THROUGH THE
REST OF THE AREA OVERNIGHT. THE BEST COLD ADVECTION AND DYNAMIC
SUPPORT SHOULD MOVE THROUGH BETWEEN ABOUT 04Z AND 12Z. FOLLOWING
FRONTAL PASSAGE...FROM NW TO SE ACROSS THE AREA TONIGHT...WINDS AT
MTN TOP LEVEL WILL SHIFT TO THE NW AND BECOME MORE NORTHERLY WITH
TIME SUNDAY. THIS WILL SHIFT THE FOCUS OF BEST SNOWFALL FROM WEST
TO NNW FACING SLOPES.
MOISTURE STEADILY ERODES SUNDAY...AS FORECAST SOUNDINGS SHOW ONLY
A SHALLOW SURFACE-BASED SATURATED LAYER REMAINING OVER THE
NORTHERN HALF OF THE AREA. TEMPERATURES IN THIS LAYER ARE IN THE
FAVORABLE RANGE FOR DENDRITIC GROWTH WITH A STRONG LAPSE RATE. IN
THESE CONDITIONS OROGRAPHIC SNOWFALL SHOULD CONTINUE IN THE
NORTHERN AND CENTRAL MOUNTAINS...BUT DIMINISH OVER THE VALLEYS AND
PLATEAUS. THE SOUNDING OVER THE SOUTHERN HALF OF THE AREA BECOMES
EVEN DRIER SO THERE A PAUSE IN SNOWFALL SHOULD OCCUR OVER MUCH OF
THE SOUTHERN MOUNTAINS SUNDAY NIGHT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 318 PM MST SAT NOV 22 2014
MONDAY IN NW FLOW A STRONG COLD DISTURBANCE DROPS THROUGH THE
REGION. AN ASSOCIATED -33C COLD CORE STEEPENS LAPSE RATES.
MOISTURE IS LIMITED AND WITH THE JET DIGGING THROUGH UTAH
DYNAMICS ARE NOT OVERLY IMPRESSIVE. BUT COLD ADVECTION...NW
OROGRAPHICS...AND THE SNOW PRODUCTION LAYER AT MTN TOP LEVEL
(-12C AT 700MB) WILL COMBINE TO PRODUCE ANOTHER ROUND OF
SIGNIFICANT SNOWFALL OVER THE NORTHERN AND CENTRAL MTNS. THE
CURRENT HIGHLIGHTS FOR MONDAY LOOK ON TRACK...THOUGH THE NW SAN
JUAN MTNS MAY NEED AN ADVISORY. HAVE RAISED POPS THERE. THE SNOW
SHOULD BE QUITE DRY FOR NOVEMBER...IN THE 20:1 RANGE.
SNOWFALL FINALLY DIMINISHES THROUGH MONDAY NIGHT AS THE TROUGH AND
ASSOCIATED JET SLIDES SE. THE MOIST MARGINALLY UNSTABLE LAYER
SHRINKS TOP DOWN INTO TUESDAY SO SOME SCATTERED SNOW SHOWERS ARE
EXPECTED IN THE EASTERN MTNS THROUGH TUESDAY AFTERNOON WITH LITTLE
ACCUMULATION EXPECTED.
TUESDAY NIGHT THROUGH SATURDAY...THE WEST COAST RIDGE SLOWLY
PROGRESSES INLAND BRINGING DRY CONDITIONS AND PERSISTENT VALLEY
INVERSIONS. UNDERCUT GUIDANCE TEMPERATURES INTO FRIDAY AS THE
RIDGE BUILDS OVER THE FORECAST AREA AND DEAMPLIFIES. THIS PROMISES
DRY CONDITIONS FOR THANKSGIVING. SATURDAY MODEL TIMING BREAKS
SOMEWHAT WITH THE GFS DIGGING THE NEXT TROUGH INTO WA-OR WHILE THE
EC HOLDS IT OFFSHORE. IF THE GFS VERIFIES WE MAY HAVE SHOWERS OVER
THE NORTH BY SUNDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY AFTERNOON)
ISSUED AT 355 PM MST SAT NOV 22 2014
A COLD FRONT WILL CONTINUE MOVING THROUGH THE AREA TONIGHT...
FOLLOWED BY A MOIST NORTHWEST FLOW THROUGH SUNDAY. SNOW IN THE
MOUNTAINS AND A MIX OF RAIN AND SNOW AT LOWER ELEVATIONS WILL
SPREAD FROM NORTHWEST TO SOUTHEAST TONIGHT...CHANGING TO SNOW AT
ALL ELEVATIONS BY ABOUT MIDNIGHT. SNOWFALL IN THE MOUNTAINS WILL
BE HEAVY AT TIMES...AND MOST MOUNTAINS WILL BECOME OBSCURED BY
MIDNIGHT. SNOW LEVELS WILL START AT ABOUT 6500 FEET THIS EVENING
THEN STEADILY DECREASE TO VALLEY BOTTOMS OVERNIGHT AND SUNDAY.
TAF SITES NORTH OF THE SAN JUAN MOUNTAINS WILL EXPERIENCE SHOWERS
THIS EVENING WITH OCCASIONAL IFR CIGS AND VSBYS AFFECTING
KASE...KEGE...KRIL AFTER 03Z AND CONTINUING OVERNIGHT AND SUNDAY.
MVFR CIGS AND VSBYS ARE EXPECTED AT ALL THE OTHER TAF SITES FROM
ABOUT 06Z THROUGH ABOUT 18Z SUNDAY...THEN GRADUALLY DECREASING.
ALSO...STRONG WEST TO NORTHWEST WINDS WILL CAUSE AREAS OF BLOWING
SNOW IN THE MOUNTAINS AND EXPOSED AREAS.
IN ADDITION...STRONG WINDS AT MOUNTAINTOP LEVEL WILL RESULT IN
MODERATE TO STRONG TURBULENCE...ESPECIALLY IN THE LEE OF HIGHER
TERRAIN.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER WEATHER ADVISORY UNTIL 6 AM MST SUNDAY FOR COZ002-003.
WINTER WEATHER ADVISORY UNTIL 3 PM MST SUNDAY FOR COZ007-008-011-
014-018-019.
WINTER STORM WARNING UNTIL 6 PM MST MONDAY FOR COZ004-005-009-
010-012-013.
UT...WINTER WEATHER ADVISORY UNTIL 6 AM MST SUNDAY FOR UTZ023.
&&
$$
UPDATE...TGR
SHORT TERM...CC
LONG TERM...JOE
AVIATION...CC
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
936 PM EST SAT NOV 22 2014
...WIDESPREAD RAINFALL TONIGHT AND SUNDAY MORNING...
...SLIGHT RISK OF SEVERE STORMS SUNDAY AFTERNOON AND EVENING...
.UPDATE...HAVE SCALED BACK POPS FOR THIS EVE ACROSS NE FL...BUT
EXPECTING WIDESPREAD RAIN TO MOVE IN ACROSS THE REGION AFTER
MIDNIGHT WITH THE APPROACH OF A WARM FRONT. MODELS INDICATE THAT THE
HEAVIEST RAINFALL AMOUNTS WILL BE ACROSS THE UPPER SUWANNEE VALLEY
INTO SE GA WHERE THERE MAY BE LOCAL AMOUNTS OF 1 TO 2 INCHES BY LATE
TONIGHT. A FEW ISOLATED ELEVATED STORMS WILL ALSO BE POSSIBLE.
&&
.AVIATION...
LATEST HRRR AND NARRE SHOW VFR CONDITIONS REMAINING IN PLACE
THROUGH THIS EVENING BEFORE LOWERING INTO THE MVFR CATEGORY DURING
THE EARLY MORNING HOURS. STRONG ISENTROPIC LIFT WILL RESULT IN
NUMEROUS TO WIDESPREAD SHOWERS WITH EMBEDDED THUNDERSTORM
DEVELOPMENT AFTER MIDNIGHT. THIS AREA OF PRECIP WILL FIRST AFFECT
NORTHEAST FLORIDA TERMINALS DURING THE EARLY MORNING HOURS AND
THEN SHIFT TOWARDS SSI CLOSER TO SUNRISE WITH RAIN LINGERING THERE
INTO SUNDAY MORNING. NE FLORIDA TERMINALS WILL SEE A LULL IN THE
RAIN AROUND SUNRISE WITH THE WARM FRONT LIFTING NORTH AND WINDS
VEERING TO THE SOUTH AND TURNING GUSTY. ADDITIONAL MAINLY LIGHT
TO MODERATE SHOWERS WILL BE POSSIBLE AT THE TERMINALS SUNDAY
AFTERNOON BUT VFR CEILINGS (3K-5K FEET) ARE LARGELY EXPECTED TO
PREVAIL IN THE WARM SECTOR SUNDAY AFTERNOON.
&&
.MARINE...
SMALL CRAFT ADVISORY CONDITIONS WILL CONTINUE FOR ALL ADJACENT
COASTAL WATERS. EAST WINDS AVERAGING 20 TO 25 KNOTS WILL VEER TO
THE SOUTH ON SUNDAY AS A WARM FRONT LIFTS NORTH ACROSS THE AREA.
SEAS WILL AVERAGE 5 TO 7 FEET NEARSHORE AND 7 TO 10 FEET OFFSHORE
WITH OCCASIONALLY HIGHER BREAKERS EXPECTED. CURRENT FORECAST
REMAINS ON TRACK AND NO CHANGES WILL BE MADE WITH THE EVENING
UPDATE.
RIP CURRENTS: HIGH RISK WILL CONTINUE DUE TO 15 TO 25 KNOT ONSHORE
WINDS AND BREAKER HEIGHTS OF 4 TO 6 FEET.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 61 73 65 77 / 100 100 70 40
SSI 63 73 66 76 / 100 100 70 40
JAX 64 78 66 81 / 100 100 50 50
SGJ 69 79 68 79 / 90 90 40 50
GNV 64 79 65 79 / 90 80 50 50
OCF 67 82 66 81 / 80 60 50 50
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK THROUGH SUNDAY EVENING FOR DUVAL-FLAGLER-
NASSAU-ST JOHNS.
GA...HIGH RIP CURRENT RISK THROUGH SUNDAY EVENING FOR COASTAL CAMDEN-
COASTAL GLYNN.
AM...SMALL CRAFT ADVISORY UNTIL 10 AM EST MONDAY FOR ALTAMAHA SOUND
GA TO FERNANDINA BEACH FL 20 NM TO 60 NM OFFSHORE-
FERNANDINA BEACH TO ST AUGUSTINE FL 20 NM TO 60 NM OFFSHORE-
ST AUGUSTINE TO FLAGLER BEACH FL 20 NM TO 60 NM OFFSHORE.
SMALL CRAFT ADVISORY UNTIL 7 PM EST SUNDAY FOR ALTAMAHA SOUND GA
TO FERNANDINA BEACH FL OUT 20 NM-FERNANDINA BEACH TO ST
AUGUSTINE FL OUT 20 NM-ST AUGUSTINE TO FLAGLER BEACH FL OUT
20 NM.
&&
$$
PETERSON/SHULER/
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
905 PM EST SAT NOV 22 2014
.UPDATE...
TONIGHT...
NOT MUCH TO ADD TO PREVIOUS DISCUSSION AS STOUT ONSHORE WINDS
GRADUALLY VEER TO THE SOUTHEAST. WARM FRONT IS ILL-DEFINED DUE TO
THIS MODIFYING ONSHORE FLOW. SHOWERS HAVE BEEN ON THE LIGHT SIDE SO
FAR. HOWEVER THE EVENING SOUNDINGS WERE SATURATED FROM 925-700 MB
WITH MIAMI HAVING 2 INCHES OF PRECIPITABLE WATER. SO EXPECT A
LARGER AREA OF RAIN WITH EMBEDDED SHOWERS TO OVERSPREAD THE AREA
FROM SOUTH TO NORTH AS LARGE SCALE LIFT DEVELOPS OUT AHEAD OF
APPROACHING SHORTWAVE TROUGH. LATEST RADAR MOSAIC SHOWS THIS MAY
ALREADY BE UNDERWAY WITH AREA OF SHOWERS EXPANDING ACROSS THE
SOUTHERN PENINSULA.
THERE IS STILL A CHANCE FOR A CONVERGENCE LINE TO SET UP FROM THE
NORTHERN BAHAMAS TO THE COAST AND PRODUCE HEAVY DOWNPOURS. THE
LOCAL WRF HAS BEEN SUGGESTING THIS AS A POSSIBLY ACROSS OUR
SOUTHERN COAST BUT THE HRRR MODEL IS VERY UNIMPRESSIVE WITH ITS
PRECIP AREAWIDE. THE VERY HIGH MOISTURE AMOUNTS AND IMPRESSIVE LOW
LEVEL WINDS SHOULD WIN OUT THOUGH AND BRING A PERIOD OF RAIN TO MOST
OF THE AREA.
WILL NOT CHANGE THE CATEGORICAL POPS ACROSS THE NORTH WHERE A LITTLE
GREATER ISENTROPIC LIFT IS EXPECTED. HAVE NUDGED UP LOW SCATTERED
NUMBERS IN THE FAR SOUTH INTERIOR TO 50 PERCENT. RAINFALL AMOUNTS
STILL LOOK LESS THAN A HALF INCH EXCEPT NEAR THE COAST WHERE 1-2
INCH AMOUNTS COULD OCCUR IF A HEAVY PRECIP BAND SETS UP FOR A FEW
HOURS.
WITH ALL THE CLOUDS AND THE ONSHORE WIND FLOW...OVERNIGHT
TEMPERATURES LOOK TO REMAIN NEARLY STEADY...AGAIN. SO FAR TODAY...
VERO BEACH HAS ONLY HAD A 3 DEGREE TEMPERATURE RANGE WHILE DAYTONA
BEACH AND MELBOURNE HAD A 4 DEGREE RANGE.
MODIFIED PREVIOUS DISCUSSION...
SUN...WE WILL BE IN THE WARM SECTOR WITH MOSTLY CLOUDY SKIES BUT
THE BULK OF THE RAIN WILL BE TO OUR NORTH. HIGH TEMPS WILL BE ABOVE
NORMAL IN THE LOW TO MID 80S WITH BREEZY S/SE FLOW AND DEW POINTS
ELEVATED INTO THE UPPER 60S TO LOWER 70S. EXPECT SCATTERED SHOWERS
AND STORMS TO DEVELOP IN THIS WARM/STICKY AIR MASS DURING AFTERNOON
HEATING. GUSTY DOWNBURST WINDS UP TO 50 MPH WILL BE POSSIBLE IN A
FEW STORMS BUT THE SEVERE THREAT SHOULD STAY NORTH OF OUR AREA.
&&
.AVIATION...
CLOUD CEILINGS HAVE BEEN QUITE VARIABLE BUT IN GENERAL EXPECT
COASTAL SITES TO HAVE OCCASIONAL MVFR UNTIL MID-LATE MORNING
SUNDAY...WHILE INTERIOR SITES HAVE OCCASIONAL IFR IN RAIN/MIST...
ESPECIALLY KLEE TO KSFB. LOW LEVEL WIND SHEAR LOOKS TO BE A GOOD
BET FOR THE INTERIOR TERMINALS AS LOW LEVELS WILL BE RAIN
COOLED/STABILIZED BUT WINDS AT 2000 FT WILL BE AROUND 30 KNOTS.
BREEZY SOUTHERLY FLOW EXPECTED SUNDAY WITH GUSTS TO 25 KNOTS.
&&
.MARINE...
TONIGHT-SUN...STRONG SMALL CRAFT ADVISORY CONDITIONS THIS EVENING
AND OVERNIGHT WITH EAST WINDS 25 KNOTS AND SEAS 8-10 FEET. THESE
CONDITIONS WILL NOT IMPROVE MUCH ON SUNDAY WHEN WINDS VEER TO THE
SOUTHEAST/SOUTH AND REMAIN AROUND 20 KNOTS WHILE SEAS ONLY SUBSIDE
A FOOT OR TWO.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY UNTIL 4 PM EST SUNDAY FOR COASTAL WATERS
FROM FLAGLER BEACH TO VOLUSIA BREVARD COUNTY LINE OUT 20 NM-
COASTAL WATERS FROM SEBASTIAN INLET TO JUPITER INLET OUT 20
NM-COASTAL WATERS FROM VOLUSIA BREVARD COUNTY LINE TO
SEBASTIAN INLET OUT 20 NM.
SMALL CRAFT ADVISORY UNTIL 5 AM EST MONDAY FOR WATERS FROM
FLAGLER BEACH TO VOLUSIA BREVARD COUNTY LINE 20 TO 60 NM
OFFSHORE-WATERS FROM SEBASTIAN INLET TO JUPITER INLET 20 TO
60 NM OFFSHORE-WATERS FROM VOLUSIA BREVARD COUNTY LINE TO
SEBASTIAN INLET 20 TO 60 NM OFFSHORE.
&&
$$
FORECASTS...LASCODY
IMPACT WX...WIMMER
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1036 PM EST SAT NOV 22 2014
.SYNOPSIS...
MOISTURE WILL RETURN TO THE REGION TONIGHT THROUGH SUNDAY
NIGHT...WITH PLENTY OF RAINFALL EXPECTED TO OCCUR SUNDAY INTO
SUNDAY NIGHT. A FRONT WILL MOVE INTO THE REGION MONDAY AND IS
EXPECTED TO STALL NEAR THE COAST TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
DRY WEATHER WILL OCCUR FOR THE FIRST PART OF THE FORECAST
WITH RAIN OVERSPREADING THE AREA LATER TONIGHT AND INTO THE
OVERNIGHT PERIOD. HIGH PRESSURE WILL CONTINUE AT THE
SURFACE...ALTHOUGH THE CENTER OF THE HIGH WILL PUSH FURTHER OFF
THE COAST OVERNIGHT. VERY WEAK SURFACE WEDGE SHOULD REMAIN ACROSS
THE AREA THROUGH MUCH OF THE NIGHT. ALOFT...ALTHOUGH WE START OFF
DRY...CLOUDS AND MOISTURE WILL RAPIDLY BE ON THE INCREASE...ESPECIALLY
ACROSS THE SOUTHWESTERN CWA AS ISENTROPIC LIFT STRENGTHENS AND
MOVES OVER THE SURFACE WEDGE. REGIONAL RADAR LOOP SHOWS SHOWERS
ACROSS NORTHERN FLORIDA AND SOUTHEASTERN GEORGIA SHIFTING NORTHEAST
INTO THE FORECAST AREA. THE HRRR MODEL APPEARS TO BE ON TRACK
WITH CURRENT RADAR TRENDS...SO HAVE SPED UP THE TIMING OF THE
SHOWERS FILLING IN FROM SOUTHWEST TO NORTHEAST ACROSS THE FA.
TEMPERATURES MAY BE SOMEWHAT TRICKY TONIGHT. CLOUDS WILL CONTINUE
TO INCREASE AND TEMPERATURES SHOULD BECOME NEARLY STEADY OR EVEN
RISE SLIGHTLY FOR THE REMAINDER OF THE NIGHT. NORTHERN COUNTIES
SHOULD CONTINUE TO FALL UNTIL LATE TONIGHT BEFORE BECOMING STEADY
TOWARDS MORNING. FOR NOW...LOWS AROUND 50 ACROSS THE SOUTH...AND
AROUND 40 ACROSS THE NORTH STILL REASONABLE.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
BY SUNDAY...S/W WILL BE ACROSS THE LOWER MS RIVER VALLEY. LOW
PRESSURE DEVELOPING ACROSS THE SOUTHERN PLAINS. A WARM FRONT TO
OUR SOUTH WILL BEGIN TO TRY AND PUSH NORTHWARD THROUGH THE DAY ON
SUNDAY/SUNDAY NIGHT. LOOKING A MODEL LI FIELDS ALONG WITH SOME
WEAK SURFACE RIDING AND SFC WINDS FROM THE NE/E FOR MUCH OF THE
DAY ON SUNDAY. THIS INDICATES AT LEAST SOME WEAK WEDGE CONDITIONS
ACROSS MUCH OF THE CWA...ESPECIALLY ACROSS THE NORTHERN/CENTRAL
MIDLANDS ALONG WITH THE NRN CSRA. WITH INCREASING ISENTROPIC LIFT
AND MOISTURE FLUX INTO THE REGION. ANY RAINFALL SHOULD HELP
SUSTAIN WEDGE CONDITIONS. HOWEVER...BY LATE IN THE DAY SUNDAY AND
SUNDAY NIGHT...SURFACE FLOW WILL INCREASE FROM THE SE AND S AS 50
TO 60 KT LOW LEVEL JET APPROACHES. PW VALUES WILL RISE
DRAMATICALLY THROUGH THE PERIOD TO WELL ABOVE 1.5
INCHES...APPROACHING NEARLY 2.0 INCHES...BY SUNDAY AFTERNOON. THIS
IS MUCH HIGHER THAN CLIMATOLOGY FOR MID/LATE NOVEMBER. WITH SUCH
IMPRESSIVE ISENTROPIC LIFT AND MOISTURE FLUX...THE RAIN WILL BE
HEAVY AT TIMES DURING THE AFTERNOON AND EVENING HOURS
SUNDAY/SUNDAY NIGHT. AS THE WARM FRONT TRIES TO MOVE
NORTH/NORTHWEST ACROSS THE AREA LATE SUNDAY INTO SUNDAY
NIGHT...THE AIRMASS ACROSS THE AREA WILL BECOME MORE UNSTABLE.
THIS IS ESPECIALLY TRUE ACROSS THE EASTERN PORTION OF THE CWA
SOUTH OF I-20. SPC DAY TWO HAS THE SERN HALF OF THE PALMETTO STATE
IN A SLIGHT RISK FOR SEVERE THUNDERSTORMS. THIS IS WHERE THE BEST
SHEAR AND INSTABILITY WILL DEVELOP. HAVE MENTIONED ISOLATED TO
CHANCE OF THUNDERSTORMS FROM LATE SUNDAY AFTERNOON INTO SUNDAY
ACROSS MUCH OF THE AREA DEVELOPING FIRST IN THE SERN PORTION OF
THE CWA AND THEN NORTH/NORTHWEST INTO THE REMAINDER OF THE CWA.
RAINFALL AMOUNTS FROM 1.5 TO 2 INCHES...WITH LOCALLY HEAVIER
AMOUNTS...WILL BE POSSIBLE BY SUNDAY NIGHT.
ON MONDAY...THE COLD FRONT ASSOCIATED WITH THE LOW IN THE PLAINS
WILL TRY TO PUSH EASTWARD ACROSS THE AREA...BUT BY
AFTERNOON/EVENING BECOMES PARALLEL TO THE UPPER FLOW AND WILL
LIKELY SLOW/STALL ALONG THE COASTAL PLAIN OR NEAR THE COAST. THIS
IS WHERE MODELS BEGIN TO DISAGREE ON HOW FAR THE FRONT WILL PUSH
EASTWARD. AT THIS TIME...HAVE CONTINUE TO KEEP A CHANCE OF
SHRA/TSRA THROUGH MONDAY WITH FRONT IN THE VICINITY.
AS FOR TEMPERATURES...THEY WILL BE VERY TRICKY ON SUNDAY WITH
WEDGE AND APPROACHING WARM FRONT FROM THE SOUTH. HAVE STAYED ON
THE LOW SIDE OF GUIDANCE FOR SUNDAY WITH A TIGHT TEMPERATURE
GRADIENT FROM NW TO SE. THE HIGH FOR SUNDAY WILL MOST LIKELY OCCUR
DURING THE EVENING HOURS AS THE WARM FRONT PUSHES NWD.
TEMPERATURES WILL BE DRAMATICALLY WARMER ON MONDAY WITH BREEZY
SOUTH/SOUTHWEST WINDS AHEAD OF THE COLD FRONT WITH ALL OF THE
GUIDANCE IN THE MID/UPPER 70S.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
UNCERTAINTIES CONTINUE IN THE FORECAST THROUGH THE MIDDLE OF NEXT
WEEK. LATEST GFS/PREVIOUS ECMWF MODELS BEGIN TO SHIFT THE MAIN UPPER
TROUGH AXIS EASTWARD AS ENERGY DROPS INTO THE BASE OF THE TROUGH
ACROSS THE SOUTHERN PLAINS BY TUE/TUE NIGHT. BY TUE NIGHT...BOTH
MODELS BEGIN TO DEVELOP LOW PRESSURE IN THE GULF OF MEXICO AND
BRING A SYSTEM UP ALONG THE EAST COAST. THIS LOOKS SLIGHTLY MORE
WESTWARD WITH PRECIPITATION SHIELD AS WELL AS COOLER THAN PREVIOUS
RUNS. HAVE LOWERED HIGHS ON WEDNESDAY A COUPLE OF DEGREES FROM THE
PREVIOUS FORECAST. BY THURSDAY AND FRIDAY...BOTH MODELS HAVE TROFINESS
ACROSS THE EASTERN HALF OF THE COUNTRY...WITH HIGH PRESSURE
BUILDING INTO THE REGION AT THE SURFACE. DRY WEATHER THANKSGIVING
DAY THROUGH SATURDAY. EXPECT TEMPERATURES TO REMAIN BELOW NORMAL
THROUGH THE PERIOD.
&&
.AVIATION /04Z SUNDAY THROUGH THURSDAY/...
HIGH CONFIDENCE VFR CONDITIONS THROUGH 06Z...THEN MVFR/IFR
CEILINGS PUSHING INTO THE REGION BY 12Z.
LIGHT EASTERLY WINDS WILL ALLOW FOR SOME MOISTURE TO MOVE IN FROM
THE EAST OVERNIGHT. THE INCREASED MOISTURE AND APPROACHING WARM
FRONT MAY ALLOW FOR WIDESPREAD PRE-FRONTAL FOG IN THE EAST... WITH
THE LARGEST IMPACT ON OGB. AT THIS TIME CONFIDENCE IN WIDESPREAD
DENSE FOG IS STILL LOW HOWEVER THERE SEEMS TO BE AGREEMENT BETWEEN
MODELS THAT FOG WILL FORM AROUND 06Z AND POSSIBLY SPREAD INTO THE
COLUMBIA AREA BY 09Z.
STRONG MOISTURE ADVECTION WILL GET LIFTED ISENTROPICALLY OVER A WEAK
SURFACE WEDGE LATE TONIGHT. THIS WILL BRING CEILINGS DOWN INTO
MVFR/IFR AS THE NIGHT PROGRESSES. RAINFALL WILL AID IN DETERIORATING
THE CONDITIONS EVEN MORE TOWARDS MORNING...WITH LIFR BECOMING
POSSIBLE AFTER 12Z AT ALL SITES. RAINFALL MAY BE HEAVY AT TIMES
THROUGH THE DAY SUNDAY...WITH LOW CEILINGS AND VISIBILITIES EXPECTED
TO LAST THROUGH THE DAY.
THERE MAY BE A BRIEF PERIOD BETWEEN 21Z AND 00Z AFTER THE WARM
FRONTAL PASSAGE BUT BEFORE THE COLD FRONTAL PASSAGE WHERE CEILINGS
MAY RECOVER AND SHOWERS BECOME LIGHT. HOWEVER THE TAF SITES WILL BE
IN THE WARM SECTOR AND INSTABILITY WILL INCREASE POSSIBLY ALLOWING
FOR MORE SHOWERS TO FORM.
EXTENDED AVIATION OUTLOOK...CEILING AND VISIBILITY RESTRICTIONS
ARE LIKELY IN RAIN SHOWERS LATE SUNDAY THROUGH MONDAY AS A LOW
PRESSURE SYSTEM AFFECTS THE REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...FLASH FLOOD WATCH THROUGH MONDAY EVENING FOR SCZ030.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
651 PM EST SAT NOV 22 2014
.SYNOPSIS...
MOISTURE WILL RETURN TO THE REGION TONIGHT THROUGH SUNDAY
NIGHT...WITH PLENTY OF RAINFALL EXPECTED TO OCCUR SUNDAY INTO
SUNDAY NIGHT. A FRONT WILL MOVE INTO THE REGION MONDAY AND IS
EXPECTED TO STALL NEAR THE COAST TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
DRY WEATHER WILL OCCUR FOR THE FIRST PART OF THE FORECAST
THIS EVENING WITH RAIN OVERSPREADING THE AREA TONIGHT AND INTO
THE OVERNIGHT PERIOD. HIGH PRESSURE WILL CONTINUE AT THE
SURFACE...ALTHOUGH THE CENTER OF THE HIGH WILL CONTINUE PUSHING
OFF THE COAST OVERNIGHT. VERY WEAK SURFACE WEDGE SHOULD REMAIN
ACROSS THE AREA THROUGH MUCH OF THE NIGHT. ALOFT...ALTHOUGH WE
START OFF DRY...CLOUDS AND MOISTURE WILL RAPIDLY BE ON THE
INCREASE...ESPECIALLY ACROSS THE SOUTHWESTERN CWA AS ISENTROPIC
LIFT STRENGTHENS AND MOVES OVER THE SURFACE WEDGE. REGIONAL RADAR
LOOP SHOWS SHOWERS ACROSS NORTHERN FLORIDA AND SOUTHEASTERN
GEORGIA BEGINNING TO SHIFT NORTHEAST TOWARD THE FORECAST AREA THIS
EVENING. THE HRRR MODEL APPEARS TO BE ON TRACK WITH CURRENT RADAR
TRENDS...SO HAVE SPED UP THE TIMING OF THE SHOWERS MOVING INTO
THE CENTRAL MIDLANDS AND PEE DEE REGION. TEMPERATURES MAY BE
SOMEWHAT TRICKY TONIGHT. CLOUDS WILL CONTINUE TO INCREASE AND
TEMPERATURES SHOULD BECOME NEARLY STEADY OR EVEN RISE SLIGHTLY FOR
THE REMAINDER OF THE NIGHT. NORTHERN COUNTIES SHOULD CONTINUE TO
FALL UNTIL LATE TONIGHT BEFORE BECOMING STEADY TOWARDS MORNING.
FOR NOW...LOWS AROUND 50 ACROSS THE SOUTH...AND AROUND 40 ACROSS
THE NORTH STILL REASONABLE.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
BY SUNDAY...S/W WILL BE ACROSS THE LOWER MS RIVER VALLEY. LOW
PRESSURE DEVELOPING ACROSS THE SOUTHERN PLAINS. A WARM FRONT TO
OUR SOUTH WILL BEGIN TO TRY AND PUSH NORTHWARD THROUGH THE DAY ON
SUNDAY/SUNDAY NIGHT. LOOKING A MODEL LI FIELDS ALONG WITH SOME
WEAK SURFACE RIDING AND SFC WINDS FROM THE NE/E FOR MUCH OF THE
DAY ON SUNDAY. THIS INDICATES AT LEAST SOME WEAK WEDGE CONDITIONS
ACROSS MUCH OF THE CWA...ESPECIALLY ACROSS THE NORTHERN/CENTRAL
MIDLANDS ALONG WITH THE NRN CSRA. WITH INCREASING ISENTROPIC LIFT
AND MOISTURE FLUX INTO THE REGION. ANY RAINFALL SHOULD HELP
SUSTAIN WEDGE CONDITIONS. HOWEVER...BY LATE IN THE DAY SUNDAY AND
SUNDAY NIGHT...SURFACE FLOW WILL INCREASE FROM THE SE AND S AS 50
TO 60 KT LOW LEVEL JET APPROACHES. PW VALUES WILL RISE
DRAMATICALLY THROUGH THE PERIOD TO WELL ABOVE 1.5
INCHES...APPROACHING NEARLY 2.0 INCHES...BY SUNDAY AFTERNOON. THIS
IS MUCH HIGHER THAN CLIMATOLOGY FOR MID/LATE NOVEMBER. WITH SUCH
IMPRESSIVE ISENTROPIC LIFT AND MOISTURE FLUX...THE RAIN WILL BE
HEAVY AT TIMES DURING THE AFTERNOON AND EVENING HOURS
SUNDAY/SUNDAY NIGHT. AS THE WARM FRONT TRIES TO MOVE
NORTH/NORTHWEST ACROSS THE AREA LATE SUNDAY INTO SUNDAY
NIGHT...THE AIRMASS ACROSS THE AREA WILL BECOME MORE UNSTABLE.
THIS IS ESPECIALLY TRUE ACROSS THE EASTERN PORTION OF THE CWA
SOUTH OF I-20. SPC DAY TWO HAS THE SERN HALF OF THE PALMETTO STATE
IN A SLIGHT RISK FOR SEVERE THUNDERSTORMS. THIS IS WHERE THE BEST
SHEAR AND INSTABILITY WILL DEVELOP. HAVE MENTIONED ISOLATED TO
CHANCE OF THUNDERSTORMS FROM LATE SUNDAY AFTERNOON INTO SUNDAY
ACROSS MUCH OF THE AREA DEVELOPING FIRST IN THE SERN PORTION OF
THE CWA AND THEN NORTH/NORTHWEST INTO THE REMAINDER OF THE CWA.
RAINFALL AMOUNTS FROM 1.5 TO 2 INCHES...WITH LOCALLY HEAVIER
AMOUNTS...WILL BE POSSIBLE BY SUNDAY NIGHT.
ON MONDAY...THE COLD FRONT ASSOCIATED WITH THE LOW IN THE PLAINS
WILL TRY TO PUSH EASTWARD ACROSS THE AREA...BUT BY
AFTERNOON/EVENING BECOMES PARALLEL TO THE UPPER FLOW AND WILL
LIKELY SLOW/STALL ALONG THE COASTAL PLAIN OR NEAR THE COAST. THIS
IS WHERE MODELS BEGIN TO DISAGREE ON HOW FAR THE FRONT WILL PUSH
EASTWARD. AT THIS TIME...HAVE CONTINUE TO KEEP A CHANCE OF
SHRA/TSRA THROUGH MONDAY WITH FRONT IN THE VICINITY.
AS FOR TEMPERATURES...THEY WILL BE VERY TRICKY ON SUNDAY WITH
WEDGE AND APPROACHING WARM FRONT FROM THE SOUTH. HAVE STAYED ON
THE LOW SIDE OF GUIDANCE FOR SUNDAY WITH A TIGHT TEMPERATURE
GRADIENT FROM NW TO SE. THE HIGH FOR SUNDAY WILL MOST LIKELY OCCUR
DURING THE EVENING HOURS AS THE WARM FRONT PUSHES NWD.
TEMPERATURES WILL BE DRAMATICALLY WARMER ON MONDAY WITH BREEZY
SOUTH/SOUTHWEST WINDS AHEAD OF THE COLD FRONT WITH ALL OF THE
GUIDANCE IN THE MID/UPPER 70S.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
UNCERTAINTIES CONTINUE IN THE FORECAST THROUGH THE MIDDLE OF NEXT
WEEK. LATEST GFS/PREVIOUS ECMWF MODELS BEGIN TO SHIFT THE MAIN UPPER
TROUGH AXIS EASTWARD AS ENERGY DROPS INTO THE BASE OF THE TROUGH
ACROSS THE SOUTHERN PLAINS BY TUE/TUE NIGHT. BY TUE NIGHT...BOTH
MODELS BEGIN TO DEVELOP LOW PRESSURE IN THE GULF OF MEXICO AND
BRING A SYSTEM UP ALONG THE EAST COAST. THIS LOOKS SLIGHTLY MORE
WESTWARD WITH PRECIPITATION SHIELD AS WELL AS COOLER THAN PREVIOUS
RUNS. HAVE LOWERED HIGHS ON WEDNESDAY A COUPLE OF DEGREES FROM THE
PREVIOUS FORECAST. BY THURSDAY AND FRIDAY...BOTH MODELS HAVE TROFINESS
ACROSS THE EASTERN HALF OF THE COUNTRY...WITH HIGH PRESSURE
BUILDING INTO THE REGION AT THE SURFACE. DRY WEATHER THANKSGIVING
DAY THROUGH SATURDAY. EXPECT TEMPERATURES TO REMAIN BELOW NORMAL
THROUGH THE PERIOD.
&&
.AVIATION /23Z SATURDAY THROUGH THURSDAY/...
HIGH CONFIDENCE VFR CONDITIONS THROUGH 06Z...THEN MVFR/IFR
CEILINGS PUSHING INTO THE REGION BY 12Z.
LIGHT EASTERLY WINDS WILL ALLOW FOR SOME MOISTURE TO MOVE IN FROM
THE EAST OVERNIGHT. THE INCREASED MOISTURE AND APPROACHING WARM
FRONT MAY ALLOW FOR WIDESPREAD PRE-FRONTAL FOG IN THE EAST... WITH
THE LARGEST IMPACT ON OGB. AT THIS TIME CONFIDENCE IN WIDESPREAD
DENSE FOG IS STILL LOW HOWEVER THERE SEEMS TO BE AGREEMENT BETWEEN
MODELS THAT FOG WILL FORM AROUND 06Z AND POSSIBLY SPREAD INTO THE
COLUMBIA AREA BY 09Z.
STRONG MOISTURE ADVECTION WILL GET LIFTED ISENTROPICALLY OVER A WEAK
SURFACE WEDGE LATE TONIGHT. THIS WILL BRING CEILINGS DOWN INTO
MVFR/IFR AS THE NIGHT PROGRESSES. RAINFALL WILL AID IN DETERIORATING
THE CONDITIONS EVEN MORE TOWARDS MORNING...WITH LIFR BECOMING
POSSIBLE AFTER 12Z AT ALL SITES. RAINFALL MAY BE HEAVY AT TIMES
THROUGH THE DAY SUNDAY...WITH LOW CEILINGS AND VISIBILITIES EXPECTED
TO LAST THROUGH THE DAY.
THERE MAY BE A BRIEF PERIOD BETWEEN 21Z AND 00Z AFTER THE WARM
FRONTAL PASSAGE BUT BEFORE THE COLD FRONTAL PASSAGE WHERE CEILINGS
MAY RECOVER AND SHOWERS BECOME LIGHT. HOWEVER THE TAF SITES WILL BE
IN THE WARM SECTOR AND INSTABILITY WILL INCREASE POSSIBLY ALLOWING
FOR MORE SHOWERS TO FORM.
EXTENDED AVIATION OUTLOOK...CEILING AND VISIBILITY RESTRICTIONS
ARE LIKELY IN RAIN SHOWERS LATE SUNDAY THROUGH MONDAY AS A LOW
PRESSURE SYSTEM AFFECTS THE REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...FLASH FLOOD WATCH THROUGH MONDAY EVENING FOR SCZ030.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
210 PM MST FRI NOV 21 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 138 PM MST FRI NOV 21 2014
MAIN CONCERNS ARE EXTENT OF FOG TONIGHT FOLLOWED BY HOW MUCH TO
WARM UP THE TEMPERATURES ON SATURDAY. LARGE AREA OF STRATUS AND
SOME FOG TO OUR SOUTH AND SOUTHEAST AT THIS TIME. RETURN FLOW WILL
BE IN PLACE BY THE TIME SUN GOES DOWN AND THE LOW LEVEL INVERSION
STRENGTHENS. SO WOULD EXPECT THIS MOISTURE TO BE ABLE TO RETURN
NORTH AND MOVE INTO THE AREA BEFORE THE WINDS SHIFT TO A WEST TO
SOUTHWEST DIRECTION BY LATER TONIGHT AS A SURFACE TROUGH MOVES
THROUGH.
HRRR FOLLOWED BY RAP HAVE BEEN DOING VERY WELL IN THE DEPICTION OF
THIS LOW LEVEL MOISTURE FIELD. BASED ON THAT AND THE OBSERVATIONS
TO OUR SOUTH...WENT AHEAD AND FOLLOWED THE HRRR/RAP VERY CLOSELY
FOR THE CLOUD COVER AND FOG FOR TONIGHT. FOG/LOW CLOUDS SHOULD
STAY IN THE EASTERN HALF TO TWO THIRDS OF THE AREA. IF HRRR ENDS
UP BEING RIGHT THERE COULD BE SOME DENSE FOG POSSIBLE IN THE FAR
EASTERN PORTION.
FOG AND STRATUS DECREASE LATE TONIGHT AND EARLY TOMORROW AS
SURFACE TROUGH MOVES THROUGH AND SHIFTS/INCREASES THE WINDS FROM
THE WEST. AT THIS TIME THE FOG SHOULD END BY MID MORNING. ONCE THE
FOG/CLOUDS CLEAR OFF THERE WILL BE PLENTIFUL SUNSHINE AND
DOWNSLOPE WINDS THROUGH 700 MB. COMBINATION OF DRY AIR MASS AND
GROUND COMBINED WITH THE ABUNDANT SUNSHINE AND DOWNSLOPE WINDS
WILL ALLOW FOR A GOOD WARMUP.
QUESTION IS HOW MUCH. THE NWP AND ESPECIALLY THE 2 METER GUIDANCE
HAS BEEN RUNNING COOL DURING THE LAST WEEK. AT THIS TIME WENT
ABOVE GUIDANCE IN MOST PLACES WITH 60S...MOSTLY MIDDLE AND UPPER
60S....ACROSS THE ENTIRE AREA.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 210 PM MST FRI NOV 21 2014
FOR THE EXTENDED FORECAST PERIOD...VARIABLE WEATHER CONDITIONS ARE
EXPECTED THROUGHOUT DUE TO PASSING COLD FRONTS UNDER A NORTHWEST
FLOW REGIME. OVERALL...THE PATTERN REMAINS FAIRLY CONSISTENT WITH
LITTLE CHANCE OF MAJOR PRECIPITATION-PRODUCING SYSTEMS REACHING THE
REGION. PRIMARY CHANGE TO THIS EXTENDED PACKAGE WAS TO REMOVE
PRECIPITATION CHANCES FOR THANKSGIVING. MORE DETAILS ON THIS BELOW.
FOR SATURDAY NIGHT INTO SUNDAY MORNING...A STRONG COLD FRONT PASSAGE
IS ANTICIPATED. TEMPERATURES WILL BE SLOW TO FALL SATURDAY NIGHT DUE
TO INCREASING CLOUD COVER. THEN...A QUICK DROP IN TEMPERATURES AND
GUSTY NORTH WINDS ARE LIKELY IMMEDIATELY BEHIND THE FRONT. AS THE
FRONT PASSES THROUGH...THE ATMOSPHERE MOISTENS AT LOW LEVELS WHEN
THE COOLER AIR INTRUDES. THERE SHOULD BE ENOUGH MID-LEVEL LIFT AND
MOISTURE FOR RAIN/SNOW SHOWERS DEVELOPMENT BUT THE QUESTION OVER THE
PAST FEW FORECAST RUNS HAS BEEN WHETHER OR NOT THIS PRECIPITATION
REACHES THE GROUND. BASED ON LATEST GUIDANCE...THERE SHOULD BE A
SMALL WINDOW OF OPPORTUNITY FOR MEASURABLE PRECIPITATION TO REACH
THE GROUND AHEAD OF INCOMING POST-FRONTAL DRY AIR. THEREFORE...
PLACED A SLIGHT CHANCE FOR MEASURABLE PRECIPITATION INTO THE
FORECAST AND MAINTAINED SPRINKLES/FLURRIES MENTION SURROUNDING THE
SLIGHT CHANCE POPS.
MAIN STORY FOR THE REST OF SUNDAY THROUGH MONDAY SHOULD BE
BREEZY/WINDY CONDITIONS AND COOL TEMPERATURES. WITH PERSISTENT COLD
AIR ADVECTION AND POSSIBLE CLOUD COVER OVERHEAD...HAVE A HARD TIME
BELIEVING THAT THE REGION WILL BE ABLE TO REACH MEX/MET/ECE GUIDANCE
TEMPERATURES. WENT BELOW GUIDANCE FOR HIGH TEMPERATURES DUE TO THIS
THINKING. REGARDING THE WINDS...MODELS ARE NOT IN STRONG AGREEMENT
WITH RESPECT TO HOW STRONG THE WINDS WILL BE AND WHEN THE STRONGEST
WINDS WILL OCCUR. ANY POSSIBLE CLOUD COVER ALSO MESSES WITH
ANTICIPATED MIXING HEIGHTS SO HARD TO TELL HOW STRONG THE MIXED DOWN
GUSTS WILL BE AT THIS TIME. WITHOUT A STRONG CUT-OFF LOW PRESSURE
SYSTEM PRESENT...CURRENTLY DO NOT BELIEVE THAT THIS WILL BE A MAJOR
WIND EVENT. TYPICAL COLD/WINDY HIGH PLAINS DAYS ARE FORECAST WITH
NORTH WINDS 20-30 MPH...GUSTING TO 45 MPH AND HIGH TEMPERATURES IN
THE LOW TO UPPER 40S.
BEYOND MONDAY...A WEAK UPPER LEVEL DISTURBANCE MOVES THROUGH THE
HIGH PLAINS TUESDAY INTO TUESDAY NIGHT. THE CR INITIALIZATION
PROCEDURE DID NOT INCLUDE POPS AND WITH A DRY LAYER OF AIR AT THE
SURFACE...THOUGHT THIS WAS APPROPRIATE. POPS MAY NEED TO BE INCLUDED
AT A LATER TIME BUT MODEL CONSISTENCY WAS NOT STRONG ENOUGH FOR
INCLUSION WITH THIS RUN.
ANOTHER STRONG UPPER LEVEL DISTURBANCE SWINGS SOUTH OVER THE PLAINS
AND INTO THE MID-MISSISSIPPI VALLEY BY THURSDAY. THIS SYSTEM SHOULD
FORCE A BACKDOOR COLD FRONT INTO THE HIGH PLAINS. IT IS HARD TO TELL
HOW FAR SOUTHWEST THIS FRONT WILL REACH AND THERE IS A STRONG CHANCE
FOR A LARGE TEMPERATURE GRADIENT ACROSS THE REGION. CURRENT
THANKSGIVING FORECAST CALLS FOR A HIGH OF 38 DEGREES AT MCCOOK
NEBRASKA...44 AT GOODLAND KANSAS AND 52 AT KIT CARSON COLORADO.
MODELS TRENDED PRECIPITATION CHANCES FOR THANKSGIVING DOWN AND
BELIEVE THIS IS ACCURATE CONSIDERING A RIDGE OF HIGH PRESSURE WILL
BUILD IN FROM THE WEST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1026 AM MST FRI NOV 21 2014
AT THIS TIME VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. THE
ONE CAVEAT TO THIS IS LATER THIS AFTERNOON INTO THIS EVENING FOR
KMCK. A LOT OF LOW LEVEL MOISTURE/CLOUD COVER REMAINS TO THE SOUTH
OF OUR AREA AT THIS TIME. A FEW OF TH MODELS BRING MVFR CONDITIONS
OR LOWER INTO THE EASTERN PORTION OF THE AREA. HOWEVER...SOME OF
THE OUTPUT BRINGS IT FURTHER WEST...CLOSE TO KMCK...WHILE OTHERS
KEEP TO THE EAST OF THE SITE. SO INSERTED A SCATTERED LOW DECK AND
WILL CONTINUE MONITOR TRENDS FOR ANY ADJUSTMENTS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...RRH
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
150 PM MST FRI NOV 21 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 138 PM MST FRI NOV 21 2014
MAIN CONCERNS ARE EXTENT OF FOG TONIGHT FOLLOWED BY HOW MUCH TO
WARM UP THE TEMPERATURES ON SATURDAY. LARGE AREA OF STRATUS AND
SOME FOG TO OUR SOUTH AND SOUTHEAST AT THIS TIME. RETURN FLOW WILL
BE IN PLACE BY THE TIME SUN GOES DOWN AND THE LOW LEVEL INVERSION
STRENGTHENS. SO WOULD EXPECT THIS MOISTURE TO BE ABLE TO RETURN
NORTH AND MOVE INTO THE AREA BEFORE THE WINDS SHIFT TO A WEST TO
SOUTHWEST DIRECTION BY LATER TONIGHT AS A SURFACE TROUGH MOVES
THROUGH.
HRRR FOLLOWED BY RAP HAVE BEEN DOING VERY WELL IN THE DEPICTION OF
THIS LOW LEVEL MOISTURE FIELD. BASED ON THAT AND THE OBSERVATIONS
TO OUR SOUTH...WENT AHEAD AND FOLLOWED THE HRRR/RAP VERY CLOSELY
FOR THE CLOUD COVER AND FOG FOR TONIGHT. FOG/LOW CLOUDS SHOULD
STAY IN THE EASTERN HALF TO TWO THIRDS OF THE AREA. IF HRRR ENDS
UP BEING RIGHT THERE COULD BE SOME DENSE FOG POSSIBLE IN THE FAR
EASTERN PORTION.
FOG AND STRATUS DECREASE LATE TONIGHT AND EARLY TOMORROW AS
SURFACE TROUGH MOVES THROUGH AND SHIFTS/INCREASES THE WINDS FROM
THE WEST. AT THIS TIME THE FOG SHOULD END BY MID MORNING. ONCE THE
FOG/CLOUDS CLEAR OFF THERE WILL BE PLENTIFUL SUNSHINE AND
DOWNSLOPE WINDS THROUGH 700 MB. COMBINATION OF DRY AIR MASS AND
GROUND COMBINED WITH THE ABUNDANT SUNSHINE AND DOWNSLOPE WINDS
WILL ALLOW FOR A GOOD WARMUP.
QUESTION IS HOW MUCH. THE NWP AND ESPECIALLY THE 2 METER GUIDANCE
HAS BEEN RUNNING COOL DURING THE LAST WEEK. AT THIS TIME WENT
ABOVE GUIDANCE IN MOST PLACES WITH 60S...MOSTLY MIDDLE AND UPPER
60S....ACROSS THE ENTIRE AREA.
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 218 AM MST FRI NOV 21 2014
MONDAY...UPPER LOW ROTATES SLOWLY EAST TOWARD THE GREAT LAKES
DURING THE DAY LIFTING SLOWLY NORTHEAST TOWARD THE UPPER GREAT
LAKES OVERNIGHT. WE WILL CONTINUE TO SEE VARYING DEGREES OF
CLOUDINESS THROUGH MONDAY NIGHT. STILL LOOKING LIKE A WINDY DAY
WITH NORTHWEST WINDS GUSTING 35 TO 40 MPH. GFS/ECMWF STILL HAVE
SOME DISAGREEMENT ON TEMPERATURES WITH THE ECMWF SHOWING 850MB
TEMPS SUPPORTING MID 30S NEAR MCCOOK TO THE LOW 40S ACROSS THE
REST OF THE AREA. GFS A FEW DEGREES WARMER. NO MAJOR CHANGES MADE
AND WILL GO WITH LOW TO MID 40S ACROSS THE AREA FOR NOW. LOWS
TONIGHT MID/UPPER TEENS IN EASTERN COLORADO AND AROUND 20
ELSEWHERE. THIS IS CLOSE TO THE CONSMOS GUIDANCE WHICH HAS
PERFORMED THE BEST AT THIS TIME RANGE THE PAST 7 DAYS.
TUESDAY...FORECAST AREA REMAINS UNDER NORTHWEST FLOW BUT 500
HEIGHTS START TO RISE AS EAST COAST TROUGH STARTS TO MOVE AWAY
AND LOSE ITS INFLUENCE OVER THE AREA WHILE TO THE WEST UPPER RIDGE
AXIS STARTS TO MOVE ASHORE ALONG THE WEST COAST. ECMWF 850MB
TEMPERATURES SLOWER TO RESPOND AND MOVE INTO THE AREA FROM THE
WEST COMPARED TO THE GFS. THIS LEADS TO A LOW CONFIDENCE FORECAST
OF LOW TO MID 40S FOR HIGH TEMPERATURES. THESE TEMPERATURES ARE
CLOSE AGAIN TO THE CONSMOS GUIDANCE WHICH AT THIS TIMEFRAME HAS
PERFORMED THE BEST THE PAST 7 DAYS. LOWS UPPER TEENS TO MID
20S...CLOSE TO NORMAL FOR THIS TIME OF YEAR. PLENTY OF MID AND
HIGH CLOUDS MOVE IN FROM THE NORTHWEST DURING THE DAY LEADING TO
SOME PARTIAL SUNSHINE AND SLOWLY MOVE EAST ACROSS THE AREA DURING
THE NIGHT.
WEDNESDAY...00Z GFS/ECMWF IN BETTER AGREEMENT AT 850MB BRINGING
MUCH WARMER TEMPERATURES INTO THE AREA FROM THE WEST. FOR THE
EASTERN PART OF THE AREA (MCCOOK AND HILL CITY AREAS) PROXIMITY TO
VARIABLE OR EASTERLY WINDS MEANS FRONTAL BOUNDARY IN THE AREA AND
UNLIKELY TO SEE FULL MIXING AND HIGHS IN THE MID/UPPER 40S LOOKS
GOOD. FURTHER WEST ALONG AND WEST OF THE CO/KS BORDER BOTH
ECMWF/GFS HAVE 850MB TEMPERATURES IN THE 10C-13C RANGE WHICH WOULD
SUPPORT HIGHS CLOSER TO 60 VS CURRENT FORECAST OF AROUND 50/LOW
50S. WONT MAKE ANY CHANGES THIS GO-AROUND AS THE UPPER PATTERN
SHOWING DIFFERING SOLUTIONS WHICH COULD EVENTUALLY LEAD TO LARGER
DISCREPANCIES CLOSER TO THE SFC. LOWS UPPER TEENS TO MID 20S. WILL
ALSO BE CARRYING A LOW CHANCE OF PRECIPITATION WEDNESDAY NIGHT BUT
LOOKING AT 850-500 MOISTURE CONFIDENCE NOT ALL THAT HIGH.
THURSDAY/THANKSGIVING...LONG RANGE MODELS SHOWING LITTLE AGREEMENT
IN UPPER AND LOW LEVEL PATTERNS. EXTENDED PROCEDURE SEEMS TO
FAVOR THE COLDER GFS SOLUTION VS THE MUCH WARMER (850MB TEMPS)
ECMWF SOLUTION. NO CHANGES MADE AND WILL GO WITH HIGHS IN THE MID
30S TO AROUND 40 WITH PARTLY TO MOSTLY CLOUDY CONDITIONS AND A
CHANCE OF LIGHT PRECIPITATION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1026 AM MST FRI NOV 21 2014
AT THIS TIME VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. THE
ONE CAVEAT TO THIS IS LATER THIS AFTERNOON INTO THIS EVENING FOR
KMCK. A LOT OF LOW LEVEL MOISTURE/CLOUD COVER REMAINS TO THE SOUTH
OF OUR AREA AT THIS TIME. A FEW OF TH MODELS BRING MVFR CONDITIONS
OR LOWER INTO THE EASTERN PORTION OF THE AREA. HOWEVER...SOME OF
THE OUTPUT BRINGS IT FURTHER WEST...CLOSE TO KMCK...WHILE OTHERS
KEEP TO THE EAST OF THE SITE. SO INSERTED A SCATTERED LOW DECK AND
WILL CONTINUE MONITOR TRENDS FOR ANY ADJUSTMENTS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...99
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1219 PM CST FRI NOV 21 2014
...UPDATED AVIATION SECTION...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 316 AM CST FRI NOV 21 2014
AN EXTENDED EAST ASIAN JET WITH H25 WINDS IN EXCESS OF 150 KTS AROUND
40N IN THE EASTERN PACIFIC IS IMPINGING ON THE SPLIT FLOW REGIME NEAR
THE WEST COAST OF NORTH AMERICA. A PORTION OF THE JET IS DIVING SOUTH
NEAR THE CALIFORNIA COAST, AND A VIGOROUS UPPER LEVEL TROUGH IN
SOUTHERN CALIFORNIA WILL CONTINUE TO DIG INTO MEXICO TODAY BEFORE
TURNING EAST AND MOVING INTO WEST TEXAS DURING THE DAY SATURDAY.
ANOTHER MINOR UPPER LEVEL TROUGH IN EASTERN NEW MEXICO WILL RIPPLE
ACROSS THE CENTRAL PLAINS TO MISSOURI BY THIS EVENING. IN THE NORTHERN
BRANCH OF THE WESTERLIES, AN UPPER LEVEL TROUGH FROM ALBERTA INTO
MONTANA WILL MOVE INTO THE DAKOTAS TODAY, AND FALLING PRESSURES IN THE
NORTHERN PLAINS WILL RESULT IN VEERING LOW LEVEL WINDS IN KANSAS LATER
TODAY AND TONIGHT.
A WEAK SURFACE CYCLONE NEAR THE RED RIVER IN FAR SOUTHWEST OKLAHOMA
WILL MOVE INTO CENTRAL OKLAHOMA BY NOON AND DISSIPATE IN NORTHEAST
OKLAHOMA BY THIS EVENING AS THE NEW MEXICO UPPER LEVEL TROUGH MOVES
ALONG THE BAROCLINIC ZONE EXTENDING FROM THE TEXAS PANHANDLE INTO
EASTERN OKLAHOMA. A SURFACE WARM FRONT WAS EVIDENT EARLY THIS MORNING
NEAR THE SOUTHERN OKLAHOMA BORDER FROM THE SURFACE CYCLONE INTO
NORTHWEST LOUISIANA. LOW LEVEL MOISTURE WAS FLOWING ACROSS TEXAS OVER
THE WARM FRONT, AND AN EXTENSIVE AREA OF STRATIFORM CLOUDINESS WAS
EXPANDING NORTHWARD ACROSS OKLAHOMA INTO EXTREME SOUTHERN KANSAS. THE
AREA OF STRATUS WILL CONTINUE TO SPREAD INTO KANSAS DURING THE MORNING
HOURS AS THE MOIST TONGUE ADVANCES OVER THE SHALLOW COLD AIR COVERING
KANSAS. THE WEST EDGE OF THE CLOUD SHIELD IS SOMEWHAT UNCERTAIN, BUT
THE HRRR SOLUTION OF KEEPING MOST OF THE STRATUS EAST OF HIGHWAY 283
SEEMS REASONABLE AND LARGELY WAS FOLLOWED FOR THE FORECAST. LIGHT
UPSLOPE FLOW IN CENTRAL AND EASTERN KANSAS TODAY WILL KEEP THE LOW
LEVELS COOL, WHILE WARM AIR OVER THE STRATIFORM CLOUD DECK WILL
PRECLUDE MUCH MIXING. AS SUCH, THE CLOUDINESS WILL BE VERY SLOW TO
ERODE AND PROBABLY WILL PERSIST THROUGH AT LEAST LATE AFTERNOON.
TEMPERATURES WILL WARM INTO THE LOW TO MID 50S IN WESTERN KANSAS,
ALTHOUGH INCREASING CIRRIFORM CLOUDINESS LATER TODAY WILL REDUCE
INSOLATION A BIT. HIGHS UNDER THE STRATUS DECK PROBABLY WILL BE ONLY
IN THE LOWER 40S. THE MOIST LAYER APPEARS LIKELY TO REMAIN
SUFFICIENTLY SHALLOW THAT THE CHANCE FOR DRIZZLE IS MINIMAL.
LOW LEVEL WINDS WILL VEER THIS EVENING IN RESPONSE TO LOWERING
PRESSURES IN THE NORTHERN UNITED STATES, AND THE STRATUS SHOULD
ERODE LATE IN THE DAY. RADIATIONAL COOLING OF THE MOIST, COOL
BOUNDARY LAYER MAY SUPPORT FORMATION OF PATCHY FOG FRIDAY NIGHT,
ESPECIALLY IN AREAS THAT MAINTAIN CLOUD COVER THROUGH THE DAY.
LOWS TONIGHT SHOULD BE NEAR CLIMATOLOGICAL VALUES FROM THE MID 20S
TO LOWER 30S. SATURDAY WILL BE CONSIDERABLY WARMER WITH DOWNSLOPE
FLOW AND ABUNDANT SUNSHINE.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 249 AM CST FRI NOV 21 2014
STARTING WITH SATURDAY MORNING, THERE WILL BE A VIGOROUS SHORT WAVE
MOVING THROUGH THE SOUTHERN PLAINS OF NORTHERN TEXAS AND SOUTHERN
OKLAHOMA. THERE WILL A TROUGH EXTENDING NORTH INTO CENTRAL
KANSAS, WITH LOWER LAYERED MOISTURE ADVECTING NORTH INTO CENTRAL
KANSAS. THE STRONGER INSTABILITY WILL REMAIN SOUTH OF OUR
FORECAST AREA, BUT THERE WILL BE A SLIGHT CHANCE FOR SHOWERS IN
THE BARBER COUNTY AREA FROM SATURDAY MORNING THROUGH SATURDAY
AFTERNOON. THERE STILL LOOKS AS IF IT WILL WARM UP ON SATURDAY,
WITH THE ECMWF MODEL PROGGED 850MB TEMPS RANGING FROM +10C TO
+12C ACROSS OUR CWA SATURDAY AFTERNOON. THIS SHOULD RESULT IN
LOWER TO MID 60S FOR MAX TEMPS. THEN BY LATE SATURDAY NIGHT, A
RATHER STRONG COLD FRONT WILL PLUNGE SOUTHEAST THROUGH WESTERN
KANSAS, BRINGING SOME LOWER TO MID CLOUDS WITH IT AND COLDER
TEMPERATURES. SUNDAY WILL BE WINDY AS WELL WITH A TIGHT SURFACE
PRESSURE GRADIENT, AND NORTHWEST WINDS OF 25 MPH GUSTING TO 35
MPH.
MONDAY AND TUESDAY, WE WILL BE DEEPER INTO THE COLD AIR AND
ASSOCIATED HIGH PRESSURE, AND MAX TEMPERATURES WILL STRUGGLE TO GET
OUT OF THE 40S BOTH MONDAY AND TUESDAY. WEDNESDAY WILL WARM INTO THE
UPPER 40S IN THE HAYS AND LARNED AREAS, AND INTO THE MID 50S DOWN
SOUTHWEST NEAR ELKHART, AS A SOUTHWEST SURFACE FLOW RETURNS.
ANOTHER STRONG COLD FRONT WILL ARRIVE WEDNESDAY NIGHT, BRINGING
A COOL DOWN, WITH A CHANCE FOR SNOW NORTH OF I-70 WEDNESDAY
NIGHT. THE FRONT WILL DIVE SOUTH THROUGH ALL OF SOUTHWESTERN
KANSAS ON THURSDAY/THANKSGIVING, BRINGING A CHANCE FOR SNOW NORTH
OF I-70; A CHANCE FOR RAIN OR SNOW FROM SCOTT CITY TO PRATT; AND A
CHANCE FOR LIGHT RAIN SOUTH OF A LINE FROM LAKIN TO DODGE CITY TO
MEDICINE LODGE. ONLY LIGHT PRECIPITATION IS EXPECTED ON
THANKSGIVING, BUT IT WILL BE BREEZY AND RATHER COLD. MAX TEMPS
ON THURSDAY WILL ONLY REACH THE MID 30S IN THE WAKEENEY AND HAYS
AREAS, THE UPPER 30S TO AROUND 40F DEGREES FROM LAKIN TO GARDEN
CITY TO DODGE CITY TO MEDICINE LODGE, AND SHOULD REACH THE MID 40S
DOWN SOUTH ALONG THE OKLAHOMA BORDER. IN THE SNOW AREAS, ONLY
0.2 TO 0.3-INCH OF SNOW IS EXPECTED.
MINIMUM TEMPERATURES THROUGH THE EXTENDED WILL BE THE WARMEST ON
SUNDAY MORNING PRIOR TO THE FIRST COLD FRONTAL PASSAGE, THEN
AVERAGE IN THE LOWER TO MIDDLE 20S FOR THE PERIOD MONDAY THROUGH
THURSDAY MORNINGS, AND THEN TAKE A PLUNGE FRIDAY MORNING INTO THE
TEENS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1218 PM CST FRI NOV 21 2014
WEAK NORTHWARD BOUNDARY LAYER MOISTURE TRANSPORT INTO A MUCH COOLER
AIRMASS HAS LED TO LOWERED LIFR CEILINGS ACROSS THE AREA EARLY THIS
AFTERNOON. TRENDS FOR THE STRATUS WILL HAVE TO BE MONITORED FOR
TAF AMENDMENTS HOWEVER SOME IMPROVEMENT SHOULD OCCUR BY MID TO
LATE AFTERNOON AS INSOLATION DEEPENS THE BL. BY LATE EVENING AND
THE OVERNIGHT, WIDESPREAD STRATUS REDEVELOPMENT SHOULD AGAIN OCCUR
WITH VISIBILITIES FALLING TO AROUND A HALF MILE AFTER 9Z.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 32 60 37 52 / 0 10 10 10
GCK 27 61 33 52 / 0 0 10 10
EHA 32 64 35 50 / 0 0 10 10
LBL 28 62 34 52 / 0 10 10 10
HYS 29 58 37 51 / 0 10 10 10
P28 35 60 44 55 / 20 20 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RUTHI
LONG TERM...BURKE
AVIATION...RUSSELL
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1029 AM MST FRI NOV 21 2014
.UPDATE...
ISSUED AT 944 AM MST FRI NOV 21 2014
JUST COMPLETED AN UPDATE. FIRST THING WAS TO RAISE MAXES.
MESOSCALE GUIDANCE THAT DID WELL YESTERDAY IS CATCHING THE RISE IN
TEMPERATURES. GUIDANCE APPEARS TO RUNNING COOL AGAIN AS IT HAS
DONE HERE RECENTLY. SKY COVER AND POSSIBLE FOG FOR LATER THIS
AFTERNOON INTO TONIGHT WILL BE THE NEXT PROBLEM.
CURRENT MID DECK OF CLOUD COVER IS LEAVING AS EXPECTED. LARGE AREA
OF LOW CLOUD COVER TO OUR SOUTH AND SOUTHEAST. THE RAP AND HRRR
APPEAR TO BE CATCHING THIS BEST. THOSE MODELS BRING NOT ONLY
STRATUS BUT SOME FOG AND DRAMATICALLY REDUCED VISIBILITIES INTO
OUR EASTERN COUNTIES LATER THIS AFTERNOON INTO THIS EVENING. DID
INCREASE SKY COVER BUT HAVE NOT ADDED ANY FOG YET. WOULD LIKE TO
WATCH TRENDS FOR A LITTLE WHILE LONGER BEFORE ADDING THIS.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY NIGHT)
ISSUED AT 218 AM MST FRI NOV 21 2014
EARLY MORNING SATELLITE IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW
UPPER LEVEL TROUGH OVER NORTHEAST US WITH ZONAL PATTERN ACROSS THE
WESTERN US. A SHORTWAVE TROUGH IS ALONG THE CENTRAL ROCKIES WITH
HIGH LEVEL MOISTURE PLUME ASSOCIATED WITH 10-15KFT CLOUD DECK
ACROSS NW KANSAS.
REGARDING MORNING FOG POTENTIAL THIS MORNING...BEYOND SREF
PROBABILITIES CONTINUING TO HIGHLIGHT FOG ACROSS OUR SOUTHERN AND
EASTERN CWA NAM/SREF/HRRR NOT SHOWING REDUCED VIS OR MUCH IN THE
WAY OF SATURATION. TD VALUES HAVE INCREASED WITH SOUTHERLY
FLOW...HOWEVER CLOUD COVER HAS LIMITED DIURNAL COOLING KEEPING TD
DEPRESSIONS HIGHER THAN PREVIOUSLY ADVERTISED. AS THESE CLOUDS
SHIFT NORTH WE COULD START TO SEE LOW LEVELS SATURATE SO I DO NOT
WANT TO COMPLETELY RULE OUT FOG...AND HAVE LEFT PATCHY FREEZING
FOG MENTION IN PLACE.
TODAY...OPAQUE CIRRUS (AND ANY STRATUS THAT DEVELOPS) WILL
QUICKLY TRANSITION NORTH. GOOD WAA WITH SOUTHERLY FLOW ACROSS THE
REGION SHOULD SUPPORT HIGHS AT LEAST AS WARM AS WEDNESDAY FOR MOST
(MID 50S). CLOUD COVER COULD LINGER LONGER IN THE EAST...SO DID
NOT GO QUITE AS HIGH AS FULL MIXING WOULD SUGGEST.
SATURDAY...WAA INCREASES ACROSS THE REGION OVERNIGHT TONIGHT INTO
SATURDAY WITH H85 TEMPS WARMING TO AROUND 12C. ASSUMING SIMILAR
MIXING TO THE LAST 3 DAYS...AND CLEAR SKIES...WE SHOULD SEE TEMPS
IN THE 60S ACROSS OUR CWA...POSSIBLY INTO THE UPPER 60S AT A FEW
LOCATIONS. RH VALUES DO DROP BELOW 20 PERCENT...HOWEVER EVEN IF A
FEW LOCATIONS REACH 15 PERCENT THRESHOLD FOR RFW...WIND GUSTS WILL
REMAIN BELOW 25 MPH BASED ON CURRENT ADVERTISED WINDS ALOFT.
SATURDAY NIGHT-SUNDAY NIGHT...STRONG UPPER LEVEL LOW MOVES OUT OF
THE CANADIAN ROCKIES INTO THE NORTHERN PLAINS BY SUNDAY...KICKING
A COLD FRONT SOUTH SATURDAY. THIS WILL BRING SEASONAL HIGH TEMPS
IN THE UPPER 40S/AROUND 50 SUNDAY. WINDS WILL INCREASE BEHIND
THIS FRONT WITH GUSTS 30-40 MPH POSSIBLE...ESPECIALLY DURING THE
DAY SUNDAY.
JET STREAK ROTATES AHEAD OF MAIN CLOSED LOW CENTER ACROSS
NEBRASKA WITH LARGE SCALE FORCING INCREASING SATURDAY NIGHT AND
TRANSITIONING SOUTH AND EAST SUNDAY. GFS/ECMWF BOTH SHOWING LIGHT
QPF OVER OUR CWA...WHILE NAM KEEPS US DRY. THERE IS A SUB CLOUD
LAYER ABOUT 7-9KFT OF TD DEPRESSIONS AROUND 30F...WHICH LOWERS
CONFIDENCE OF ANY MEASURABLE PRECIP REACHING THE SURFACE. MODELS
ARE SATURATING THE MID LEVELS...WITH WEAK INSTABILITY WITHIN THIS
SATURATED LAYER...SO I DONT WANT TO COMPLETELY RULE OUT PRECIP. I
INTRODUCED FLURRY/SPRINKLES SATURDAY-SUNDAY MORNING FOR NOW...WITH
LOW CONFIDENCE ON MEASURABLE.
WINDY CONDITIONS AND THICK CLOUD COVER SHOULD CONTINUE THROUGH
SUNDAY NIGHT WHICH MAY KEEP LOW LEVELS MIXING AND HOLD UP
OVERNIGHT LOWS DESPITE COLDER AIR FILTERING INTO THE PLAINS.
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 218 AM MST FRI NOV 21 2014
MONDAY...UPPER LOW ROTATES SLOWLY EAST TOWARD THE GREAT LAKES
DURING THE DAY LIFTING SLOWLY NORTHEAST TOWARD THE UPPER GREAT
LAKES OVERNIGHT. WE WILL CONTINUE TO SEE VARYING DEGREES OF
CLOUDINESS THROUGH MONDAY NIGHT. STILL LOOKING LIKE A WINDY DAY
WITH NORTHWEST WINDS GUSTING 35 TO 40 MPH. GFS/ECMWF STILL HAVE
SOME DISAGREEMENT ON TEMPERATURES WITH THE ECMWF SHOWING 850MB
TEMPS SUPPORTING MID 30S NEAR MCCOOK TO THE LOW 40S ACROSS THE
REST OF THE AREA. GFS A FEW DEGREES WARMER. NO MAJOR CHANGES MADE
AND WILL GO WITH LOW TO MID 40S ACROSS THE AREA FOR NOW. LOWS
TONIGHT MID/UPPER TEENS IN EASTERN COLORADO AND AROUND 20
ELSEWHERE. THIS IS CLOSE TO THE CONSMOS GUIDANCE WHICH HAS
PERFORMED THE BEST AT THIS TIME RANGE THE PAST 7 DAYS.
TUESDAY...FORECAST AREA REMAINS UNDER NORTHWEST FLOW BUT 500
HEIGHTS START TO RISE AS EAST COAST TROUGH STARTS TO MOVE AWAY
AND LOSE ITS INFLUENCE OVER THE AREA WHILE TO THE WEST UPPER RIDGE
AXIS STARTS TO MOVE ASHORE ALONG THE WEST COAST. ECMWF 850MB
TEMPERATURES SLOWER TO RESPOND AND MOVE INTO THE AREA FROM THE
WEST COMPARED TO THE GFS. THIS LEADS TO A LOW CONFIDENCE FORECAST
OF LOW TO MID 40S FOR HIGH TEMPERATURES. THESE TEMPERATURES ARE
CLOSE AGAIN TO THE CONSMOS GUIDANCE WHICH AT THIS TIMEFRAME HAS
PERFORMED THE BEST THE PAST 7 DAYS. LOWS UPPER TEENS TO MID
20S...CLOSE TO NORMAL FOR THIS TIME OF YEAR. PLENTY OF MID AND
HIGH CLOUDS MOVE IN FROM THE NORTHWEST DURING THE DAY LEADING TO
SOME PARTIAL SUNSHINE AND SLOWLY MOVE EAST ACROSS THE AREA DURING
THE NIGHT.
WEDNESDAY...00Z GFS/ECMWF IN BETTER AGREEMENT AT 850MB BRINGING
MUCH WARMER TEMPERATURES INTO THE AREA FROM THE WEST. FOR THE
EASTERN PART OF THE AREA (MCCOOK AND HILL CITY AREAS) PROXIMITY TO
VARIABLE OR EASTERLY WINDS MEANS FRONTAL BOUNDARY IN THE AREA AND
UNLIKELY TO SEE FULL MIXING AND HIGHS IN THE MID/UPPER 40S LOOKS
GOOD. FURTHER WEST ALONG AND WEST OF THE CO/KS BORDER BOTH
ECMWF/GFS HAVE 850MB TEMPERATURES IN THE 10C-13C RANGE WHICH WOULD
SUPPORT HIGHS CLOSER TO 60 VS CURRENT FORECAST OF AROUND 50/LOW
50S. WONT MAKE ANY CHANGES THIS GO-AROUND AS THE UPPER PATTERN
SHOWING DIFFERING SOLUTIONS WHICH COULD EVENTUALLY LEAD TO LARGER
DISCREPANCIES CLOSER TO THE SFC. LOWS UPPER TEENS TO MID 20S. WILL
ALSO BE CARRYING A LOW CHANCE OF PRECIPITATION WEDNESDAY NIGHT BUT
LOOKING AT 850-500 MOISTURE CONFIDENCE NOT ALL THAT HIGH.
THURSDAY/THANKSGIVING...LONG RANGE MODELS SHOWING LITTLE AGREEMENT
IN UPPER AND LOW LEVEL PATTERNS. EXTENDED PROCEDURE SEEMS TO
FAVOR THE COLDER GFS SOLUTION VS THE MUCH WARMER (850MB TEMPS)
ECMWF SOLUTION. NO CHANGES MADE AND WILL GO WITH HIGHS IN THE MID
30S TO AROUND 40 WITH PARTLY TO MOSTLY CLOUDY CONDITIONS AND A
CHANCE OF LIGHT PRECIPITATION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1026 AM MST FRI NOV 21 2014
AT THIS TIME VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. THE
ONE CAVEAT TO THIS IS LATER THIS AFTERNOON INTO THIS EVENING FOR
KMCK. A LOT OF LOW LEVEL MOISTURE/CLOUD COVER REMAINS TO THE SOUTH
OF OUR AREA AT THIS TIME. A FEW OF TH MODELS BRING MVFR CONDITIONS
OR LOWER INTO THE EASTERN PORTION OF THE AREA. HOWEVER...SOME OF
THE OUTPUT BRINGS IT FURTHER WEST...CLOSE TO KMCK...WHILE OTHERS
KEEP TO THE EAST OF THE SITE. SO INSERTED A SCATTERED LOW DECK AND
WILL CONTINUE MONITOR TRENDS FOR ANY ADJUSTMENTS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...BULLER
SHORT TERM...DR
LONG TERM...99
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
954 AM MST FRI NOV 21 2014
.UPDATE...
ISSUED AT 944 AM MST FRI NOV 21 2014
JUST COMPLETED AN UPDATE. FIRST THING WAS TO RAISE MAXES.
MESOSCALE GUIDANCE THAT DID WELL YESTERDAY IS CATCHING THE RISE IN
TEMPERATURES. GUIDANCE APPEARS TO RUNNING COOL AGAIN AS IT HAS
DONE HERE RECENTLY. SKY COVER AND POSSIBLE FOG FOR LATER THIS
AFTERNOON INTO TONIGHT WILL BE THE NEXT PROBLEM.
CURRENT MID DECK OF CLOUD COVER IS LEAVING AS EXPECTED. LARGE AREA
OF LOW CLOUD COVER TO OUR SOUTH AND SOUTHEAST. THE RAP AND HRRR
APPEAR TO BE CATCHING THIS BEST. THOSE MODELS BRING NOT ONLY
STRATUS BUT SOME FOG AND DRAMATICALLY REDUCED VISIBILITIES INTO
OUR EASTERN COUNTIES LATER THIS AFTERNOON INTO THIS EVENING. DID
INCREASE SKY COVER BUT HAVE NOT ADDED ANY FOG YET. WOULD LIKE TO
WATCH TRENDS FOR A LITTLE WHILE LONGER BEFORE ADDING THIS.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY NIGHT)
ISSUED AT 218 AM MST FRI NOV 21 2014
EARLY MORNING SATELLITE IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW
UPPER LEVEL TROUGH OVER NORTHEAST US WITH ZONAL PATTERN ACROSS THE
WESTERN US. A SHORTWAVE TROUGH IS ALONG THE CENTRAL ROCKIES WITH
HIGH LEVEL MOISTURE PLUME ASSOCIATED WITH 10-15KFT CLOUD DECK
ACROSS NW KANSAS.
REGARDING MORNING FOG POTENTIAL THIS MORNING...BEYOND SREF
PROBABILITIES CONTINUING TO HIGHLIGHT FOG ACROSS OUR SOUTHERN AND
EASTERN CWA NAM/SREF/HRRR NOT SHOWING REDUCED VIS OR MUCH IN THE
WAY OF SATURATION. TD VALUES HAVE INCREASED WITH SOUTHERLY
FLOW...HOWEVER CLOUD COVER HAS LIMITED DIURNAL COOLING KEEPING TD
DEPRESSIONS HIGHER THAN PREVIOUSLY ADVERTISED. AS THESE CLOUDS
SHIFT NORTH WE COULD START TO SEE LOW LEVELS SATURATE SO I DO NOT
WANT TO COMPLETELY RULE OUT FOG...AND HAVE LEFT PATCHY FREEZING
FOG MENTION IN PLACE.
TODAY...OPAQUE CIRRUS (AND ANY STRATUS THAT DEVELOPS) WILL
QUICKLY TRANSITION NORTH. GOOD WAA WITH SOUTHERLY FLOW ACROSS THE
REGION SHOULD SUPPORT HIGHS AT LEAST AS WARM AS WEDNESDAY FOR MOST
(MID 50S). CLOUD COVER COULD LINGER LONGER IN THE EAST...SO DID
NOT GO QUITE AS HIGH AS FULL MIXING WOULD SUGGEST.
SATURDAY...WAA INCREASES ACROSS THE REGION OVERNIGHT TONIGHT INTO
SATURDAY WITH H85 TEMPS WARMING TO AROUND 12C. ASSUMING SIMILAR
MIXING TO THE LAST 3 DAYS...AND CLEAR SKIES...WE SHOULD SEE TEMPS
IN THE 60S ACROSS OUR CWA...POSSIBLY INTO THE UPPER 60S AT A FEW
LOCATIONS. RH VALUES DO DROP BELOW 20 PERCENT...HOWEVER EVEN IF A
FEW LOCATIONS REACH 15 PERCENT THRESHOLD FOR RFW...WIND GUSTS WILL
REMAIN BELOW 25 MPH BASED ON CURRENT ADVERTISED WINDS ALOFT.
SATURDAY NIGHT-SUNDAY NIGHT...STRONG UPPER LEVEL LOW MOVES OUT OF
THE CANADIAN ROCKIES INTO THE NORTHERN PLAINS BY SUNDAY...KICKING
A COLD FRONT SOUTH SATURDAY. THIS WILL BRING SEASONAL HIGH TEMPS
IN THE UPPER 40S/AROUND 50 SUNDAY. WINDS WILL INCREASE BEHIND
THIS FRONT WITH GUSTS 30-40 MPH POSSIBLE...ESPECIALLY DURING THE
DAY SUNDAY.
JET STREAK ROTATES AHEAD OF MAIN CLOSED LOW CENTER ACROSS
NEBRASKA WITH LARGE SCALE FORCING INCREASING SATURDAY NIGHT AND
TRANSITIONING SOUTH AND EAST SUNDAY. GFS/ECMWF BOTH SHOWING LIGHT
QPF OVER OUR CWA...WHILE NAM KEEPS US DRY. THERE IS A SUB CLOUD
LAYER ABOUT 7-9KFT OF TD DEPRESSIONS AROUND 30F...WHICH LOWERS
CONFIDENCE OF ANY MEASURABLE PRECIP REACHING THE SURFACE. MODELS
ARE SATURATING THE MID LEVELS...WITH WEAK INSTABILITY WITHIN THIS
SATURATED LAYER...SO I DONT WANT TO COMPLETELY RULE OUT PRECIP. I
INTRODUCED FLURRY/SPRINKLES SATURDAY-SUNDAY MORNING FOR NOW...WITH
LOW CONFIDENCE ON MEASURABLE.
WINDY CONDITIONS AND THICK CLOUD COVER SHOULD CONTINUE THROUGH
SUNDAY NIGHT WHICH MAY KEEP LOW LEVELS MIXING AND HOLD UP
OVERNIGHT LOWS DESPITE COLDER AIR FILTERING INTO THE PLAINS.
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 218 AM MST FRI NOV 21 2014
MONDAY...UPPER LOW ROTATES SLOWLY EAST TOWARD THE GREAT LAKES
DURING THE DAY LIFTING SLOWLY NORTHEAST TOWARD THE UPPER GREAT
LAKES OVERNIGHT. WE WILL CONTINUE TO SEE VARYING DEGREES OF
CLOUDINESS THROUGH MONDAY NIGHT. STILL LOOKING LIKE A WINDY DAY
WITH NORTHWEST WINDS GUSTING 35 TO 40 MPH. GFS/ECMWF STILL HAVE
SOME DISAGREEMENT ON TEMPERATURES WITH THE ECMWF SHOWING 850MB
TEMPS SUPPORTING MID 30S NEAR MCCOOK TO THE LOW 40S ACROSS THE
REST OF THE AREA. GFS A FEW DEGREES WARMER. NO MAJOR CHANGES MADE
AND WILL GO WITH LOW TO MID 40S ACROSS THE AREA FOR NOW. LOWS
TONIGHT MID/UPPER TEENS IN EASTERN COLORADO AND AROUND 20
ELSEWHERE. THIS IS CLOSE TO THE CONSMOS GUIDANCE WHICH HAS
PERFORMED THE BEST AT THIS TIME RANGE THE PAST 7 DAYS.
TUESDAY...FORECAST AREA REMAINS UNDER NORTHWEST FLOW BUT 500
HEIGHTS START TO RISE AS EAST COAST TROUGH STARTS TO MOVE AWAY
AND LOSE ITS INFLUENCE OVER THE AREA WHILE TO THE WEST UPPER RIDGE
AXIS STARTS TO MOVE ASHORE ALONG THE WEST COAST. ECMWF 850MB
TEMPERATURES SLOWER TO RESPOND AND MOVE INTO THE AREA FROM THE
WEST COMPARED TO THE GFS. THIS LEADS TO A LOW CONFIDENCE FORECAST
OF LOW TO MID 40S FOR HIGH TEMPERATURES. THESE TEMPERATURES ARE
CLOSE AGAIN TO THE CONSMOS GUIDANCE WHICH AT THIS TIMEFRAME HAS
PERFORMED THE BEST THE PAST 7 DAYS. LOWS UPPER TEENS TO MID
20S...CLOSE TO NORMAL FOR THIS TIME OF YEAR. PLENTY OF MID AND
HIGH CLOUDS MOVE IN FROM THE NORTHWEST DURING THE DAY LEADING TO
SOME PARTIAL SUNSHINE AND SLOWLY MOVE EAST ACROSS THE AREA DURING
THE NIGHT.
WEDNESDAY...00Z GFS/ECMWF IN BETTER AGREEMENT AT 850MB BRINGING
MUCH WARMER TEMPERATURES INTO THE AREA FROM THE WEST. FOR THE
EASTERN PART OF THE AREA (MCCOOK AND HILL CITY AREAS) PROXIMITY TO
VARIABLE OR EASTERLY WINDS MEANS FRONTAL BOUNDARY IN THE AREA AND
UNLIKELY TO SEE FULL MIXING AND HIGHS IN THE MID/UPPER 40S LOOKS
GOOD. FURTHER WEST ALONG AND WEST OF THE CO/KS BORDER BOTH
ECMWF/GFS HAVE 850MB TEMPERATURES IN THE 10C-13C RANGE WHICH WOULD
SUPPORT HIGHS CLOSER TO 60 VS CURRENT FORECAST OF AROUND 50/LOW
50S. WONT MAKE ANY CHANGES THIS GO-AROUND AS THE UPPER PATTERN
SHOWING DIFFERING SOLUTIONS WHICH COULD EVENTUALLY LEAD TO LARGER
DISCREPANCIES CLOSER TO THE SFC. LOWS UPPER TEENS TO MID 20S. WILL
ALSO BE CARRYING A LOW CHANCE OF PRECIPITATION WEDNESDAY NIGHT BUT
LOOKING AT 850-500 MOISTURE CONFIDENCE NOT ALL THAT HIGH.
THURSDAY/THANKSGIVING...LONG RANGE MODELS SHOWING LITTLE AGREEMENT
IN UPPER AND LOW LEVEL PATTERNS. EXTENDED PROCEDURE SEEMS TO
FAVOR THE COLDER GFS SOLUTION VS THE MUCH WARMER (850MB TEMPS)
ECMWF SOLUTION. NO CHANGES MADE AND WILL GO WITH HIGHS IN THE MID
30S TO AROUND 40 WITH PARTLY TO MOSTLY CLOUDY CONDITIONS AND A
CHANCE OF LIGHT PRECIPITATION.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 426 AM MST FRI NOV 21 2014
GUIDANCE HAS BACKED OFF ON FOG POTENTIAL. CLOUD COVER HAS LIMITED
COOLING AND KEPT LOW LEVELS FROM SATURATING DESPITE INCREASING LOW
LEVEL MOISTURE FROM THE SOUTH. WHILE CLEARING SKIES AT KGLD AROUND
SUNRISE MAY SUPPORT COOLING TEMPS...SURFACE WINDS AROUND 10KT
WOULD KEEP LOW LEVELS MIXED THIS MORNING LIMITING LOCALIZED FOG
DEVELOPMENT. I KEPT VFR CONDITIONS PREVAILING FOR BOTH KGLD AND
KMCK TAFS. WINDS DURING THE DAY MAY GUST TO 15-20KT WITH DAYTIME
MIXING...MAINLY AT KGLD. WINDS AROUND 10KT WILL BEGIN TO THE
SHIFT TO THE SOUTHWEST AT KGLD AFTER SUNSET AS SURFACE LOW
PRESSURE BEGINS TO SLIDE EAST.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...BULLER
SHORT TERM...DR
LONG TERM...99
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
426 AM MST FRI NOV 21 2014
.SHORT TERM...(TODAY THROUGH SUNDAY NIGHT)
ISSUED AT 218 AM MST FRI NOV 21 2014
EARLY MORNING SATELLITE IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW
UPPER LEVEL TROUGH OVER NORTHEAST US WITH ZONAL PATTERN ACROSS THE
WESTERN US. A SHORTWAVE TROUGH IS ALONG THE CENTRAL ROCKIES WITH
HIGH LEVEL MOISTURE PLUME ASSOCIATED WITH 10-15KFT CLOUD DECK
ACROSS NW KANSAS.
REGARDING MORNING FOG POTENTIAL THIS MORNING...BEYOND SREF
PROBABILITIES CONTINUING TO HIGHLIGHT FOG ACROSS OUR SOUTHERN AND
EASTERN CWA NAM/SREF/HRRR NOT SHOWING REDUCED VIS OR MUCH IN THE
WAY OF SATURATION. TD VALUES HAVE INCREASED WITH SOUTHERLY
FLOW...HOWEVER CLOUD COVER HAS LIMITED DIURNAL COOLING KEEPING TD
DEPRESSIONS HIGHER THAN PREVIOUSLY ADVERTISED. AS THESE CLOUDS
SHIFT NORTH WE COULD START TO SEE LOW LEVELS SATURATE SO I DO NOT
WANT TO COMPLETELY RULE OUT FOG...AND HAVE LEFT PATCHY FREEZING
FOG MENTION IN PLACE.
TODAY...OPAQUE CIRRUS (AND ANY STRATUS THAT DEVELOPS) WILL
QUICKLY TRANSITION NORTH. GOOD WAA WITH SOUTHERLY FLOW ACROSS THE
REGION SHOULD SUPPORT HIGHS AT LEAST AS WARM AS WEDNESDAY FOR MOST
(MID 50S). CLOUD COVER COULD LINGER LONGER IN THE EAST...SO DID
NOT GO QUITE AS HIGH AS FULL MIXING WOULD SUGGEST.
SATURDAY...WAA INCREASES ACROSS THE REGION OVERNIGHT TONIGHT INTO
SATURDAY WITH H85 TEMPS WARMING TO AROUND 12C. ASSUMING SIMILAR
MIXING TO THE LAST 3 DAYS...AND CLEAR SKIES...WE SHOULD SEE TEMPS
IN THE 60S ACROSS OUR CWA...POSSIBLY INTO THE UPPER 60S AT A FEW
LOCATIONS. RH VALUES DO DROP BELOW 20 PERCENT...HOWEVER EVEN IF A
FEW LOCATIONS REACH 15 PERCENT THRESHOLD FOR RFW...WIND GUSTS WILL
REMAIN BELOW 25 MPH BASED ON CURRENT ADVERTISED WINDS ALOFT.
SATURDAY NIGHT-SUNDAY NIGHT...STRONG UPPER LEVEL LOW MOVES OUT OF
THE CANADIAN ROCKIES INTO THE NORTHERN PLAINS BY SUNDAY...KICKING
A COLD FRONT SOUTH SATURDAY. THIS WILL BRING SEASONAL HIGH TEMPS
IN THE UPPER 40S/AROUND 50 SUNDAY. WINDS WILL INCREASE BEHIND
THIS FRONT WITH GUSTS 30-40 MPH POSSIBLE...ESPECIALLY DURING THE
DAY SUNDAY.
JET STREAK ROTATES AHEAD OF MAIN CLOSED LOW CENTER ACROSS
NEBRASKA WITH LARGE SCALE FORCING INCREASING SATURDAY NIGHT AND
TRANSITIONING SOUTH AND EAST SUNDAY. GFS/ECMWF BOTH SHOWING LIGHT
QPF OVER OUR CWA...WHILE NAM KEEPS US DRY. THERE IS A SUB CLOUD
LAYER ABOUT 7-9KFT OF TD DEPRESSIONS AROUND 30F...WHICH LOWERS
CONFIDENCE OF ANY MEASURABLE PRECIP REACHING THE SURFACE. MODELS
ARE SATURATING THE MID LEVELS...WITH WEAK INSTABILITY WITHIN THIS
SATURATED LAYER...SO I DONT WANT TO COMPLETELY RULE OUT PRECIP. I
INTRODUCED FLURRY/SPRINKLES SATURDAY-SUNDAY MORNING FOR NOW...WITH
LOW CONFIDENCE ON MEASURABLE.
WINDY CONDITIONS AND THICK CLOUD COVER SHOULD CONTINUE THROUGH
SUNDAY NIGHT WHICH MAY KEEP LOW LEVELS MIXING AND HOLD UP
OVERNIGHT LOWS DESPITE COLDER AIR FILTERING INTO THE PLAINS.
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 218 AM MST FRI NOV 21 2014
MONDAY...UPPER LOW ROTATES SLOWLY EAST TOWARD THE GREAT LAKES
DURING THE DAY LIFTING SLOWLY NORTHEAST TOWARD THE UPPER GREAT
LAKES OVERNIGHT. WE WILL CONTINUE TO SEE VARYING DEGREES OF
CLOUDINESS THROUGH MONDAY NIGHT. STILL LOOKING LIKE A WINDY DAY
WITH NORTHWEST WINDS GUSTING 35 TO 40 MPH. GFS/ECMWF STILL HAVE
SOME DISAGREEMENT ON TEMPERATURES WITH THE ECMWF SHOWING 850MB
TEMPS SUPPORTING MID 30S NEAR MCCOOK TO THE LOW 40S ACROSS THE
REST OF THE AREA. GFS A FEW DEGREES WARMER. NO MAJOR CHANGES MADE
AND WILL GO WITH LOW TO MID 40S ACROSS THE AREA FOR NOW. LOWS
TONIGHT MID/UPPER TEENS IN EASTERN COLORADO AND AROUND 20
ELSEWHERE. THIS IS CLOSE TO THE CONSMOS GUIDANCE WHICH HAS
PERFORMED THE BEST AT THIS TIME RANGE THE PAST 7 DAYS.
TUESDAY...FORECAST AREA REMAINS UNDER NORTHWEST FLOW BUT 500
HEIGHTS START TO RISE AS EAST COAST TROUGH STARTS TO MOVE AWAY
AND LOSE ITS INFLUENCE OVER THE AREA WHILE TO THE WEST UPPER RIDGE
AXIS STARTS TO MOVE ASHORE ALONG THE WEST COAST. ECMWF 850MB
TEMPERATURES SLOWER TO RESPOND AND MOVE INTO THE AREA FROM THE
WEST COMPARED TO THE GFS. THIS LEADS TO A LOW CONFIDENCE FORECAST
OF LOW TO MID 40S FOR HIGH TEMPERATURES. THESE TEMPERATURES ARE
CLOSE AGAIN TO THE CONSMOS GUIDANCE WHICH AT THIS TIMEFRAME HAS
PERFORMED THE BEST THE PAST 7 DAYS. LOWS UPPER TEENS TO MID
20S...CLOSE TO NORMAL FOR THIS TIME OF YEAR. PLENTY OF MID AND
HIGH CLOUDS MOVE IN FROM THE NORTHWEST DURING THE DAY LEADING TO
SOME PARTIAL SUNSHINE AND SLOWLY MOVE EAST ACROSS THE AREA DURING
THE NIGHT.
WEDNESDAY...00Z GFS/ECMWF IN BETTER AGREEMENT AT 850MB BRINGING
MUCH WARMER TEMPERATURES INTO THE AREA FROM THE WEST. FOR THE
EASTERN PART OF THE AREA (MCCOOK AND HILL CITY AREAS) PROXIMITY TO
VARIABLE OR EASTERLY WINDS MEANS FRONTAL BOUNDARY IN THE AREA AND
UNLIKELY TO SEE FULL MIXING AND HIGHS IN THE MID/UPPER 40S LOOKS
GOOD. FURTHER WEST ALONG AND WEST OF THE CO/KS BORDER BOTH
ECMWF/GFS HAVE 850MB TEMPERATURES IN THE 10C-13C RANGE WHICH WOULD
SUPPORT HIGHS CLOSER TO 60 VS CURRENT FORECAST OF AROUND 50/LOW
50S. WONT MAKE ANY CHANGES THIS GO-AROUND AS THE UPPER PATTERN
SHOWING DIFFERING SOLUTIONS WHICH COULD EVENTUALLY LEAD TO LARGER
DISCREPANCIES CLOSER TO THE SFC. LOWS UPPER TEENS TO MID 20S. WILL
ALSO BE CARRYING A LOW CHANCE OF PRECIPITATION WEDNESDAY NIGHT BUT
LOOKING AT 850-500 MOISTURE CONFIDENCE NOT ALL THAT HIGH.
THURSDAY/THANKSGIVING...LONG RANGE MODELS SHOWING LITTLE AGREEMENT
IN UPPER AND LOW LEVEL PATTERNS. EXTENDED PROCEDURE SEEMS TO
FAVOR THE COLDER GFS SOLUTION VS THE MUCH WARMER (850MB TEMPS)
ECMWF SOLUTION. NO CHANGES MADE AND WILL GO WITH HIGHS IN THE MID
30S TO AROUND 40 WITH PARTLY TO MOSTLY CLOUDY CONDITIONS AND A
CHANCE OF LIGHT PRECIPITATION.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 426 AM MST FRI NOV 21 2014
GUIDANCE HAS BACKED OFF ON FOG POTENTIAL. CLOUD COVER HAS LIMITED
COOLING AND KEPT LOW LEVELS FROM SATURATING DESPITE INCREASING LOW
LEVEL MOISTURE FROM THE SOUTH. WHILE CLEARING SKIES AT KGLD AROUND
SUNRISE MAY SUPPORT COOLING TEMPS...SURFACE WINDS AROUND 10KT
WOULD KEEP LOW LEVELS MIXED THIS MORNING LIMITING LOCALIZED FOG
DEVELOPMENT. I KEPT VFR CONDITIONS PREVAILING FOR BOTH KGLD AND
KMCK TAFS. WINDS DURING THE DAY MAY GUST TO 15-20KT WITH DAYTIME
MIXING...MAINLY AT KGLD. WINDS AROUND 10KT WILL BEGIN TO THE
SHIFT TO THE SOUTHWEST AT KGLD AFTER SUNSET AS SURFACE LOW
PRESSURE BEGINS TO SLIDE EAST.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...99
AVIATION...DR
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
511 AM CST FRI NOV 21 2014
...UPDATED FOR THE AVIATION DISCUSSION...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 316 AM CST FRI NOV 21 2014
AN EXTENDED EAST ASIAN JET WITH H25 WINDS IN EXCESS OF 150 KTS AROUND
40N IN THE EASTERN PACIFIC IS IMPINGING ON THE SPLIT FLOW REGIME NEAR
THE WEST COAST OF NORTH AMERICA. A PORTION OF THE JET IS DIVING SOUTH
NEAR THE CALIFORNIA COAST, AND A VIGOROUS UPPER LEVEL TROUGH IN
SOUTHERN CALIFORNIA WILL CONTINUE TO DIG INTO MEXICO TODAY BEFORE
TURNING EAST AND MOVING INTO WEST TEXAS DURING THE DAY SATURDAY.
ANOTHER MINOR UPPER LEVEL TROUGH IN EASTERN NEW MEXICO WILL RIPPLE
ACROSS THE CENTRAL PLAINS TO MISSOURI BY THIS EVENING. IN THE NORTHERN
BRANCH OF THE WESTERLIES, AN UPPER LEVEL TROUGH FROM ALBERTA INTO
MONTANA WILL MOVE INTO THE DAKOTAS TODAY, AND FALLING PRESSURES IN THE
NORTHERN PLAINS WILL RESULT IN VEERING LOW LEVEL WINDS IN KANSAS LATER
TODAY AND TONIGHT.
A WEAK SURFACE CYCLONE NEAR THE RED RIVER IN FAR SOUTHWEST OKLAHOMA
WILL MOVE INTO CENTRAL OKLAHOMA BY NOON AND DISSIPATE IN NORTHEAST
OKLAHOMA BY THIS EVENING AS THE NEW MEXICO UPPER LEVEL TROUGH MOVES
ALONG THE BAROCLINIC ZONE EXTENDING FROM THE TEXAS PANHANDLE INTO
EASTERN OKLAHOMA. A SURFACE WARM FRONT WAS EVIDENT EARLY THIS MORNING
NEAR THE SOUTHERN OKLAHOMA BORDER FROM THE SURFACE CYCLONE INTO
NORTHWEST LOUISIANA. LOW LEVEL MOISTURE WAS FLOWING ACROSS TEXAS OVER
THE WARM FRONT, AND AN EXTENSIVE AREA OF STRATIFORM CLOUDINESS WAS
EXPANDING NORTHWARD ACROSS OKLAHOMA INTO EXTREME SOUTHERN KANSAS. THE
AREA OF STRATUS WILL CONTINUE TO SPREAD INTO KANSAS DURING THE MORNING
HOURS AS THE MOIST TONGUE ADVANCES OVER THE SHALLOW COLD AIR COVERING
KANSAS. THE WEST EDGE OF THE CLOUD SHIELD IS SOMEWHAT UNCERTAIN, BUT
THE HRRR SOLUTION OF KEEPING MOST OF THE STRATUS EAST OF HIGHWAY 283
SEEMS REASONABLE AND LARGELY WAS FOLLOWED FOR THE FORECAST. LIGHT
UPSLOPE FLOW IN CENTRAL AND EASTERN KANSAS TODAY WILL KEEP THE LOW
LEVELS COOL, WHILE WARM AIR OVER THE STRATIFORM CLOUD DECK WILL
PRECLUDE MUCH MIXING. AS SUCH, THE CLOUDINESS WILL BE VERY SLOW TO
ERODE AND PROBABLY WILL PERSIST THROUGH AT LEAST LATE AFTERNOON.
TEMPERATURES WILL WARM INTO THE LOW TO MID 50S IN WESTERN KANSAS,
ALTHOUGH INCREASING CIRRIFORM CLOUDINESS LATER TODAY WILL REDUCE
INSOLATION A BIT. HIGHS UNDER THE STRATUS DECK PROBABLY WILL BE ONLY
IN THE LOWER 40S. THE MOIST LAYER APPEARS LIKELY TO REMAIN
SUFFICIENTLY SHALLOW THAT THE CHANCE FOR DRIZZLE IS MINIMAL.
LOW LEVEL WINDS WILL VEER THIS EVENING IN RESPONSE TO LOWERING
PRESSURES IN THE NORTHERN UNITED STATES, AND THE STRATUS SHOULD
ERODE LATE IN THE DAY. RADIATIONAL COOLING OF THE MOIST, COOL
BOUNDARY LAYER MAY SUPPORT FORMATION OF PATCHY FOG FRIDAY NIGHT,
ESPECIALLY IN AREAS THAT MAINTAIN CLOUD COVER THROUGH THE DAY.
LOWS TONIGHT SHOULD BE NEAR CLIMATOLOGICAL VALUES FROM THE MID 20S
TO LOWER 30S. SATURDAY WILL BE CONSIDERABLY WARMER WITH DOWNSLOPE
FLOW AND ABUNDANT SUNSHINE.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 249 AM CST FRI NOV 21 2014
STARTING WITH SATURDAY MORNING, THERE WILL BE A VIGOROUS SHORT WAVE
MOVING THROUGH THE SOUTHERN PLAINS OF NORTHERN TEXAS AND SOUTHERN
OKLAHOMA. THERE WILL A TROUGH EXTENDING NORTH INTO CENTRAL
KANSAS, WITH LOWER LAYERED MOISTURE ADVECTING NORTH INTO CENTRAL
KANSAS. THE STRONGER INSTABILITY WILL REMAIN SOUTH OF OUR
FORECAST AREA, BUT THERE WILL BE A SLIGHT CHANCE FOR SHOWERS IN
THE BARBER COUNTY AREA FROM SATURDAY MORNING THROUGH SATURDAY
AFTERNOON. THERE STILL LOOKS AS IF IT WILL WARM UP ON SATURDAY,
WITH THE ECMWF MODEL PROGGED 850MB TEMPS RANGING FROM +10C TO
+12C ACROSS OUR CWA SATURDAY AFTERNOON. THIS SHOULD RESULT IN
LOWER TO MID 60S FOR MAX TEMPS. THEN BY LATE SATURDAY NIGHT, A
RATHER STRONG COLD FRONT WILL PLUNGE SOUTHEAST THROUGH WESTERN
KANSAS, BRINGING SOME LOWER TO MID CLOUDS WITH IT AND COLDER
TEMPERATURES. SUNDAY WILL BE WINDY AS WELL WITH A TIGHT SURFACE
PRESSURE GRADIENT, AND NORTHWEST WINDS OF 25 MPH GUSTING TO 35
MPH.
MONDAY AND TUESDAY, WE WILL BE DEEPER INTO THE COLD AIR AND
ASSOCIATED HIGH PRESSURE, AND MAX TEMPERATURES WILL STRUGGLE TO GET
OUT OF THE 40S BOTH MONDAY AND TUESDAY. WEDNESDAY WILL WARM INTO THE
UPPER 40S IN THE HAYS AND LARNED AREAS, AND INTO THE MID 50S DOWN
SOUTHWEST NEAR ELKHART, AS A SOUTHWEST SURFACE FLOW RETURNS.
ANOTHER STRONG COLD FRONT WILL ARRIVE WEDNESDAY NIGHT, BRINGING
A COOL DOWN, WITH A CHANCE FOR SNOW NORTH OF I-70 WEDNESDAY
NIGHT. THE FRONT WILL DIVE SOUTH THROUGH ALL OF SOUTHWESTERN
KANSAS ON THURSDAY/THANKSGIVING, BRINGING A CHANCE FOR SNOW NORTH
OF I-70; A CHANCE FOR RAIN OR SNOW FROM SCOTT CITY TO PRATT; AND A
CHANCE FOR LIGHT RAIN SOUTH OF A LINE FROM LAKIN TO DODGE CITY TO
MEDICINE LODGE. ONLY LIGHT PRECIPITATION IS EXPECTED ON
THANKSGIVING, BUT IT WILL BE BREEZY AND RATHER COLD. MAX TEMPS
ON THURSDAY WILL ONLY REACH THE MID 30S IN THE WAKEENEY AND HAYS
AREAS, THE UPPER 30S TO AROUND 40F DEGREES FROM LAKIN TO GARDEN
CITY TO DODGE CITY TO MEDICINE LODGE, AND SHOULD REACH THE MID 40S
DOWN SOUTH ALONG THE OKLAHOMA BORDER. IN THE SNOW AREAS, ONLY
0.2 TO 0.3-INCH OF SNOW IS EXPECTED.
MINIMUM TEMPERATURES THROUGH THE EXTENDED WILL BE THE WARMEST ON
SUNDAY MORNING PRIOR TO THE FIRST COLD FRONTAL PASSAGE, THEN
AVERAGE IN THE LOWER TO MIDDLE 20S FOR THE PERIOD MONDAY THROUGH
THURSDAY MORNINGS, AND THEN TAKE A PLUNGE FRIDAY MORNING INTO THE
TEENS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 503 AM CST FRI NOV 21 2014
STRATUS AND LIGHT FOG WILL MOVE IN THIS MORNING, BRINGING MVFR
CONDITIONS. CIGS MAY REDUCE TO BELOW IFR CONDITIONS FOR A BRIEF
TIME JUST AFTER SUNRISE AT KDDC AND KHYS. MVFR CIGS AROUND OVC015
WILL PERSIST THROUGH THE EARLY AFTERNOON, AND START TO BREAK UP BY
20Z. VFR CONDITIONS ARE EXPECTED AFTER 20Z TO 21Z.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 47 31 60 37 / 0 0 10 10
GCK 53 26 61 33 / 0 0 0 10
EHA 56 32 64 35 / 0 0 0 10
LBL 53 28 62 34 / 0 0 10 10
HYS 44 28 58 37 / 0 0 10 10
P28 44 34 60 44 / 10 10 20 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RUTHI
LONG TERM...BURKE
AVIATION...BURKE
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
323 AM CST FRI NOV 21 2014
...UPDATED SHORT TERM SECTION...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 316 AM CST FRI NOV 21 2014
AN EXTENDED EAST ASIAN JET WITH H25 WINDS IN EXCESS OF 150 KTS AROUND
40N IN THE EASTERN PACIFIC IS IMPINGING ON THE SPLIT FLOW REGIME NEAR
THE WEST COAST OF NORTH AMERICA. A PORTION OF THE JET IS DIVING SOUTH
NEAR THE CALIFORNIA COAST, AND A VIGOROUS UPPER LEVEL TROUGH IN
SOUTHERN CALIFORNIA WILL CONTINUE TO DIG INTO MEXICO TODAY BEFORE
TURNING EAST AND MOVING INTO WEST TEXAS DURING THE DAY SATURDAY.
ANOTHER MINOR UPPER LEVEL TROUGH IN EASTERN NEW MEXICO WILL RIPPLE
ACROSS THE CENTRAL PLAINS TO MISSOURI BY THIS EVENING. IN THE NORTHERN
BRANCH OF THE WESTERLIES, AN UPPER LEVEL TROUGH FROM ALBERTA INTO
MONTANA WILL MOVE INTO THE DAKOTAS TODAY, AND FALLING PRESSURES IN THE
NORTHERN PLAINS WILL RESULT IN VEERING LOW LEVEL WINDS IN KANSAS LATER
TODAY AND TONIGHT.
A WEAK SURFACE CYCLONE NEAR THE RED RIVER IN FAR SOUTHWEST OKLAHOMA
WILL MOVE INTO CENTRAL OKLAHOMA BY NOON AND DISSIPATE IN NORTHEAST
OKLAHOMA BY THIS EVENING AS THE NEW MEXICO UPPER LEVEL TROUGH MOVES
ALONG THE BAROCLINIC ZONE EXTENDING FROM THE TEXAS PANHANDLE INTO
EASTERN OKLAHOMA. A SURFACE WARM FRONT WAS EVIDENT EARLY THIS MORNING
NEAR THE SOUTHERN OKLAHOMA BORDER FROM THE SURFACE CYCLONE INTO
NORTHWEST LOUISIANA. LOW LEVEL MOISTURE WAS FLOWING ACROSS TEXAS OVER
THE WARM FRONT, AND AN EXTENSIVE AREA OF STRATIFORM CLOUDINESS WAS
EXPANDING NORTHWARD ACROSS OKLAHOMA INTO EXTREME SOUTHERN KANSAS. THE
AREA OF STRATUS WILL CONTINUE TO SPREAD INTO KANSAS DURING THE MORNING
HOURS AS THE MOIST TONGUE ADVANCES OVER THE SHALLOW COLD AIR COVERING
KANSAS. THE WEST EDGE OF THE CLOUD SHIELD IS SOMEWHAT UNCERTAIN, BUT
THE HRRR SOLUTION OF KEEPING MOST OF THE STRATUS EAST OF HIGHWAY 283
SEEMS REASONABLE AND LARGELY WAS FOLLOWED FOR THE FORECAST. LIGHT
UPSLOPE FLOW IN CENTRAL AND EASTERN KANSAS TODAY WILL KEEP THE LOW
LEVELS COOL, WHILE WARM AIR OVER THE STRATIFORM CLOUD DECK WILL
PRECLUDE MUCH MIXING. AS SUCH, THE CLOUDINESS WILL BE VERY SLOW TO
ERODE AND PROBABLY WILL PERSIST THROUGH AT LEAST LATE AFTERNOON.
TEMPERATURES WILL WARM INTO THE LOW TO MID 50S IN WESTERN KANSAS,
ALTHOUGH INCREASING CIRRIFORM CLOUDINESS LATER TODAY WILL REDUCE
INSOLATION A BIT. HIGHS UNDER THE STRATUS DECK PROBABLY WILL BE ONLY
IN THE LOWER 40S. THE MOIST LAYER APPEARS LIKELY TO REMAIN
SUFFICIENTLY SHALLOW THAT THE CHANCE FOR DRIZZLE IS MINIMAL.
LOW LEVEL WINDS WILL VEER THIS EVENING IN RESPONSE TO LOWERING
PRESSURES IN THE NORTHERN UNITED STATES, AND THE STRATUS SHOULD
ERODE LATE IN THE DAY. RADIATIONAL COOLING OF THE MOIST, COOL
BOUNDARY LAYER MAY SUPPORT FORMATION OF PATCHY FOG FRIDAY NIGHT,
ESPECIALLY IN AREAS THAT MAINTAIN CLOUD COVER THROUGH THE DAY.
LOWS TONIGHT SHOULD BE NEAR CLIMATOLOGICAL VALUES FROM THE MID 20S
TO LOWER 30S. SATURDAY WILL BE CONSIDERABLY WARMER WITH DOWNSLOPE
FLOW AND ABUNDANT SUNSHINE.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 249 AM CST FRI NOV 21 2014
STARTING WITH SATURDAY MORNING, THERE WILL BE A VIGOROUS SHORT WAVE
MOVING THROUGH THE SOUTHERN PLAINS OF NORTHERN TEXAS AND SOUTHERN
OKLAHOMA. THERE WILL A TROUGH EXTENDING NORTH INTO CENTRAL
KANSAS, WITH LOWER LAYERED MOISTURE ADVECTING NORTH INTO CENTRAL
KANSAS. THE STRONGER INSTABILITY WILL REMAIN SOUTH OF OUR
FORECAST AREA, BUT THERE WILL BE A SLIGHT CHANCE FOR SHOWERS IN
THE BARBER COUNTY AREA FROM SATURDAY MORNING THROUGH SATURDAY
AFTERNOON. THERE STILL LOOKS AS IF IT WILL WARM UP ON SATURDAY,
WITH THE ECMWF MODEL PROGGED 850MB TEMPS RANGING FROM +10C TO
+12C ACROSS OUR CWA SATURDAY AFTERNOON. THIS SHOULD RESULT IN
LOWER TO MID 60S FOR MAX TEMPS. THEN BY LATE SATURDAY NIGHT, A
RATHER STRONG COLD FRONT WILL PLUNGE SOUTHEAST THROUGH WESTERN
KANSAS, BRINGING SOME LOWER TO MID CLOUDS WITH IT AND COLDER
TEMPERATURES. SUNDAY WILL BE WINDY AS WELL WITH A TIGHT SURFACE
PRESSURE GRADIENT, AND NORTHWEST WINDS OF 25 MPH GUSTING TO 35
MPH.
MONDAY AND TUESDAY, WE WILL BE DEEPER INTO THE COLD AIR AND
ASSOCIATED HIGH PRESSURE, AND MAX TEMPERATURES WILL STRUGGLE TO GET
OUT OF THE 40S BOTH MONDAY AND TUESDAY. WEDNESDAY WILL WARM INTO THE
UPPER 40S IN THE HAYS AND LARNED AREAS, AND INTO THE MID 50S DOWN
SOUTHWEST NEAR ELKHART, AS A SOUTHWEST SURFACE FLOW RETURNS.
ANOTHER STRONG COLD FRONT WILL ARRIVE WEDNESDAY NIGHT, BRINGING
A COOL DOWN, WITH A CHANCE FOR SNOW NORTH OF I-70 WEDNESDAY
NIGHT. THE FRONT WILL DIVE SOUTH THROUGH ALL OF SOUTHWESTERN
KANSAS ON THURSDAY/THANKSGIVING, BRINGING A CHANCE FOR SNOW NORTH
OF I-70; A CHANCE FOR RAIN OR SNOW FROM SCOTT CITY TO PRATT; AND A
CHANCE FOR LIGHT RAIN SOUTH OF A LINE FROM LAKIN TO DODGE CITY TO
MEDICINE LODGE. ONLY LIGHT PRECIPITATION IS EXPECTED ON
THANKSGIVING, BUT IT WILL BE BREEZY AND RATHER COLD. MAX TEMPS
ON THURSDAY WILL ONLY REACH THE MID 30S IN THE WAKEENEY AND HAYS
AREAS, THE UPPER 30S TO AROUND 40F DEGREES FROM LAKIN TO GARDEN
CITY TO DODGE CITY TO MEDICINE LODGE, AND SHOULD REACH THE MID 40S
DOWN SOUTH ALONG THE OKLAHOMA BORDER. IN THE SNOW AREAS, ONLY
0.2 TO 0.3-INCH OF SNOW IS EXPECTED.
MINIMUM TEMPERATURES THROUGH THE EXTENDED WILL BE THE WARMEST ON
SUNDAY MORNING PRIOR TO THE FIRST COLD FRONTAL PASSAGE, THEN
AVERAGE IN THE LOWER TO MIDDLE 20S FOR THE PERIOD MONDAY THROUGH
THURSDAY MORNINGS, AND THEN TAKE A PLUNGE FRIDAY MORNING INTO THE
TEENS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1150 PM CST THU NOV 20 2014
.AVIATION... AN UPPER LEVEL TROUGH EXTENDING FROM WESTERN WYOMING
INTO CENTRAL NEW MEXICO EARLY THIS MORNING WILL MOVE ACROSS THE
CENTRAL PLAINS INTO IOWA BY FRIDAY NIGHT. AT THE SURFACE, A WEAK LOW
CENTERED WEST OF WICHITA FALLS, TX WILL MOVE INTO CENTRAL OKLAHOMA
BY NOON AND DISSIPATE IN NORTHEAST OKLAHOMA THIS EVENING. LOW LEVEL
MOISTURE WILL SPREAD NORTH INTO KANSAS FRIDAY MORNING, AND STRATUS
WITH BASES BLO010 CAN BE EXPECTED TO MOVE INTO DDC 12-14Z AND INTO
HYS BY 15Z. PATCHY FREEZING FOG WITH LOCAL VSBYS NEAR 1 MILE CAN BE
EXPECTED FROM 12-14Z. THE STRATUS GRADUALLY WILL ERODE THIS
AFTERNOON WITH SCT-BKN CLOUDS 010-020 BY 21Z. PATCHY FOG MAY
REDEVELOP AFTER MIDNIGHT MAINLY EAST OF HIGHWAY 283.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 51 31 60 37 / 0 0 10 10
GCK 53 26 61 33 / 0 0 0 10
EHA 56 32 64 35 / 0 0 0 10
LBL 53 28 62 34 / 0 0 10 10
HYS 45 28 58 37 / 0 0 10 10
P28 45 34 60 44 / 10 10 20 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RUTHI
LONG TERM...BURKE
AVIATION...RUTHI
AREA FORECAST DISCUSSION
NWS GOODLAND KS
219 AM MST FRI NOV 21 2014
.SHORT TERM...(TODAY THROUGH SUNDAY NIGHT)
ISSUED AT 218 AM MST FRI NOV 21 2014
EARLY MORNING SATELLITE IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW
UPPER LEVEL TROUGH OVER NORTHEAST US WITH ZONAL PATTERN ACROSS THE
WESTERN US. A SHORTWAVE TROUGH IS ALONG THE CENTRAL ROCKIES WITH
HIGH LEVEL MOISTURE PLUME ASSOCIATED WITH 10-15KFT CLOUD DECK
ACROSS NW KANSAS.
REGARDING MORNING FOG POTENTIAL THIS MORNING...BEYOND SREF
PROBABILITIES CONTINUING TO HIGHLIGHT FOG ACROSS OUR SOUTHERN AND
EASTERN CWA NAM/SREF/HRRR NOT SHOWING REDUCED VIS OR MUCH IN THE
WAY OF SATURATION. TD VALUES HAVE INCREASED WITH SOUTHERLY
FLOW...HOWEVER CLOUD COVER HAS LIMITED DIURNAL COOLING KEEPING TD
DEPRESSIONS HIGHER THAN PREVIOUSLY ADVERTISED. AS THESE CLOUDS
SHIFT NORTH WE COULD START TO SEE LOW LEVELS SATURATE SO I DO NOT
WANT TO COMPLETELY RULE OUT FOG...AND HAVE LEFT PATCHY FREEZING
FOG MENTION IN PLACE.
TODAY...OPAQUE CIRRUS (AND ANY STRATUS THAT DEVELOPS) WILL
QUICKLY TRANSITION NORTH. GOOD WAA WITH SOUTHERLY FLOW ACROSS THE
REGION SHOULD SUPPORT HIGHS AT LEAST AS WARM AS WEDNESDAY FOR MOST
(MID 50S). CLOUD COVER COULD LINGER LONGER IN THE EAST...SO DID
NOT GO QUITE AS HIGH AS FULL MIXING WOULD SUGGEST.
SATURDAY...WAA INCREASES ACROSS THE REGION OVERNIGHT TONIGHT INTO
SATURDAY WITH H85 TEMPS WARMING TO AROUND 12C. ASSUMING SIMILAR
MIXING TO THE LAST 3 DAYS...AND CLEAR SKIES...WE SHOULD SEE TEMPS
IN THE 60S ACROSS OUR CWA...POSSIBLY INTO THE UPPER 60S AT A FEW
LOCATIONS. RH VALUES DO DROP BELOW 20 PERCENT...HOWEVER EVEN IF A
FEW LOCATIONS REACH 15 PERCENT THRESHOLD FOR RFW...WIND GUSTS WILL
REMAIN BELOW 25 MPH BASED ON CURRENT ADVERTISED WINDS ALOFT.
SATURDAY NIGHT-SUNDAY NIGHT...STRONG UPPER LEVEL LOW MOVES OUT OF
THE CANADIAN ROCKIES INTO THE NORTHERN PLAINS BY SUNDAY...KICKING
A COLD FRONT SOUTH SATURDAY. THIS WILL BRING SEASONAL HIGH TEMPS
IN THE UPPER 40S/AROUND 50 SUNDAY. WINDS WILL INCREASE BEHIND
THIS FRONT WITH GUSTS 30-40 MPH POSSIBLE...ESPECIALLY DURING THE
DAY SUNDAY.
JET STREAK ROTATES AHEAD OF MAIN CLOSED LOW CENTER ACROSS
NEBRASKA WITH LARGE SCALE FORCING INCREASING SATURDAY NIGHT AND
TRANSITIONING SOUTH AND EAST SUNDAY. GFS/ECMWF BOTH SHOWING LIGHT
QPF OVER OUR CWA...WHILE NAM KEEPS US DRY. THERE IS A SUB CLOUD
LAYER ABOUT 7-9KFT OF TD DEPRESSIONS AROUND 30F...WHICH LOWERS
CONFIDENCE OF ANY MEASURABLE PRECIP REACHING THE SURFACE. MODELS
ARE SATURATING THE MID LEVELS...WITH WEAK INSTABILITY WITHIN THIS
SATURATED LAYER...SO I DONT WANT TO COMPLETELY RULE OUT PRECIP. I
INTRODUCED FLURRY/SPRINKLES SATURDAY-SUNDAY MORNING FOR NOW...WITH
LOW CONFIDENCE ON MEASURABLE.
WINDY CONDITIONS AND THICK CLOUD COVER SHOULD CONTINUE THROUGH
SUNDAY NIGHT WHICH MAY KEEP LOW LEVELS MIXING AND HOLD UP
OVERNIGHT LOWS DESPITE COLDER AIR FILTERING INTO THE PLAINS.
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 218 AM MST FRI NOV 21 2014
MONDAY...UPPER LOW ROTATES SLOWLY EAST TOWARD THE GREAT LAKES
DURING THE DAY LIFTING SLOWLY NORTHEAST TOWARD THE UPPER GREAT
LAKES OVERNIGHT. WE WILL CONTINUE TO SEE VARYING DEGREES OF
CLOUDINESS THROUGH MONDAY NIGHT. STILL LOOKING LIKE A WINDY DAY
WITH NORTHWEST WINDS GUSTING 35 TO 40 MPH. GFS/ECMWF STILL HAVE
SOME DISAGREEMENT ON TEMPERATURES WITH THE ECMWF SHOWING 850MB
TEMPS SUPPORTING MID 30S NEAR MCCOOK TO THE LOW 40S ACROSS THE
REST OF THE AREA. GFS A FEW DEGREES WARMER. NO MAJOR CHANGES MADE
AND WILL GO WITH LOW TO MID 40S ACROSS THE AREA FOR NOW. LOWS
TONIGHT MID/UPPER TEENS IN EASTERN COLORADO AND AROUND 20
ELSEWHERE. THIS IS CLOSE TO THE CONSMOS GUIDANCE WHICH HAS
PERFORMED THE BEST AT THIS TIME RANGE THE PAST 7 DAYS.
TUESDAY...FORECAST AREA REMAINS UNDER NORTHWEST FLOW BUT 500
HEIGHTS START TO RISE AS EAST COAST TROUGH STARTS TO MOVE AWAY
AND LOSE ITS INFLUENCE OVER THE AREA WHILE TO THE WEST UPPER RIDGE
AXIS STARTS TO MOVE ASHORE ALONG THE WEST COAST. ECMWF 850MB
TEMPERATURES SLOWER TO RESPOND AND MOVE INTO THE AREA FROM THE
WEST COMPARED TO THE GFS. THIS LEADS TO A LOW CONFIDENCE FORECAST
OF LOW TO MID 40S FOR HIGH TEMPERATURES. THESE TEMPERATURES ARE
CLOSE AGAIN TO THE CONSMOS GUIDANCE WHICH AT THIS TIMEFRAME HAS
PERFORMED THE BEST THE PAST 7 DAYS. LOWS UPPER TEENS TO MID
20S...CLOSE TO NORMAL FOR THIS TIME OF YEAR. PLENTY OF MID AND
HIGH CLOUDS MOVE IN FROM THE NORTHWEST DURING THE DAY LEADING TO
SOME PARTIAL SUNSHINE AND SLOWLY MOVE EAST ACROSS THE AREA DURING
THE NIGHT.
WEDNESDAY...00Z GFS/ECMWF IN BETTER AGREEMENT AT 850MB BRINGING
MUCH WARMER TEMPERATURES INTO THE AREA FROM THE WEST. FOR THE
EASTERN PART OF THE AREA (MCCOOK AND HILL CITY AREAS) PROXIMITY TO
VARIABLE OR EASTERLY WINDS MEANS FRONTAL BOUNDARY IN THE AREA AND
UNLIKELY TO SEE FULL MIXING AND HIGHS IN THE MID/UPPER 40S LOOKS
GOOD. FURTHER WEST ALONG AND WEST OF THE CO/KS BORDER BOTH
ECMWF/GFS HAVE 850MB TEMPERATURES IN THE 10C-13C RANGE WHICH WOULD
SUPPORT HIGHS CLOSER TO 60 VS CURRENT FORECAST OF AROUND 50/LOW
50S. WONT MAKE ANY CHANGES THIS GO-AROUND AS THE UPPER PATTERN
SHOWING DIFFERING SOLUTIONS WHICH COULD EVENTUALLY LEAD TO LARGER
DISCREPANCIES CLOSER TO THE SFC. LOWS UPPER TEENS TO MID 20S. WILL
ALSO BE CARRYING A LOW CHANCE OF PRECIPITATION WEDNESDAY NIGHT BUT
LOOKING AT 850-500 MOISTURE CONFIDENCE NOT ALL THAT HIGH.
THURSDAY/THANKSGIVING...LONG RANGE MODELS SHOWING LITTLE AGREEMENT
IN UPPER AND LOW LEVEL PATTERNS. EXTENDED PROCEDURE SEEMS TO
FAVOR THE COLDER GFS SOLUTION VS THE MUCH WARMER (850MB TEMPS)
ECMWF SOLUTION. NO CHANGES MADE AND WILL GO WITH HIGHS IN THE MID
30S TO AROUND 40 WITH PARTLY TO MOSTLY CLOUDY CONDITIONS AND A
CHANCE OF LIGHT PRECIPITATION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1026 PM MST THU NOV 20 2014
FOR KGLD...VFR CONDITIONS THROUGH FORECAST PERIOD WITH SCT-
BKN150-250. WINDS WILL MEANDER FROM SSE TO THE S AT 5-10KTS OVER
THE NEXT COUPLE OF HOURS...BECOMING SSW 5-10KTS AFT 07Z.
FOR KMCK...VFR CONDITIONS THRU 09Z WITH BKN150-200...THEN 5SM IN
FOG POSSIBLE THROUGH 15Z TOMORROW MORNING. AFT 15Z FRIDAY...SCT-
BKN150. WINDS SE 5-10KTS BECOMING SOUTH BY 15Z THEN SW BY 00Z
SATURDAY AROUND 5KTS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...99
AVIATION...JN
AREA FORECAST DISCUSSION
NWS WICHITA KS
1130 PM CST THU NOV 20 2014
...UPDATED FOR 06Z AVIATION DISCUSSION...
.UPDATE...
ISSUED AT 1130 PM CST THU NOV 20 2014
REST OF TONIGHT:
TEMPERATURE/DEW POINT DIFFERENTIALS ACROSS THE NEIGHBORHOOD REMAIN
8-13F IN NEARLY ALL AREAS AND WITH MOISTURE ADVECTION EXTREMELY
LIMITED AT 11 PM. LOW CLOUDS HAVE DEVELOPED OVER PARTS OF EASTERN
OK AND AR AND ARE MIGRATING V-E-R-Y S-L-O-W-L-Y NORTH. RUC & HRRR
SOUNDINGS DEPICT A LATER ARRIVAL OF STRATUS INTO SOUTH-CENTRAL AND
SOUTHEAST KS UNTIL AROUND 5 AM. AS SUCH HAVE UPDATED ALL FORECASTS
TO DELAY THE ARRIVAL OF ANY DRIZZLE TIL AROUND 5 AM. THE POTENTIAL
FOR LIGHT FREEZING DRIZZLE IS LIKEWISE DIMINISHING (CERTAINLY THRU
6 AM). REMAINDER OF INHERITED FORECAST IS UNCHANGED.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 345 PM CST THU NOV 20 2014
LIGHT FREEZING DRIZZLE REMAINS A CONCERN DURING THE OVERNIGHT HOURS
AS LOW LEVEL MOISTURE IS DRAWN UP FROM CENTRAL/EASTERN OKLAHOMA. AS
FAR AS TIMING GOES, IT APPEARS THE ONSET OF DRIZZLE WILL BE 08-10Z
TIME FRAME ALONG/SOUTH OF KINGMAN-WICHITA-CHANUTE LINE. THE NORTHERN
EDGE OF THE DRIZZLE, AS IT MOVES NORTH DURING THIS TIME FRAME, WILL
BEGIN TO MOVE INTO AREAS WHERE SURFACE TEMPERATURE WILL BE ANYWHERE
FROM 28 TO 31F. THIS WILL UNDOUBTEDLY CAUSE A VERY LIGHT GLAZE ON
EXPOSED SURFACES AND UNTREATED ROADS/SIDEWALKS. AS THE AREA OF LIGHT
DRIZZLE EXPANDS NORTHWARD TO A GREAT BEND-MCPHERSON-EMPORIA LINE,
THE 32F SURFACE LINE WILL ALSO SHIFT NORTH AS SURFACE WARM ADVECTION
BEGINS TO INCREASE. AFTER DAYBREAK (INDIRECT) INSOLATION WILL ALLOW
TEMPERATURES TO INCREASE TO THE MID 30S JUST ABOUT EVERYWHERE
INCLUDING FARTHER NORTH ACROSS CENTRAL KANSAS. THE OFFICIAL FORECAST
CALLS FOR PLAIN DRIZZLE ESPECIALLY AFTER 15Z EXCEPT FOR PERHAPS THE
I-70 CORRIDOR WHERE IT MAY REMAIN AT OR BELOW 32F THROUGH 16 OR EVEN
17Z. IT WILL BE DIFFICULT FOR ANY FREEZING DRIZZLE TO REACH AS FAR
NORTHWEST AS RUSSELL, BUT WE WILL ALSO INCLUDE SOME PATCHY FREEZING
DRIZZLE GIVEN REMAINING PLACEMENT UNCERTAINTIES. FOR THE REMAINDER
OF THE DAY, AREAS OF DRIZZLE WILL CONTINUE PRIMARILY EAST OF KINGMAN
TO SALINA LINE, AND THE DRIZZLE/LOW STRATUS WILL RESULT IN
TEMPERATURES ONLY SLOWLY RISING TO A HIGH OF UPPER 30S FOR MUCH OF
CENTRAL KANSAS. THE EXCEPTION WILL BE SOUTHEAST KANSAS WHERE TEMPS
WILL LIKELY RISE TO THE MID TO UPPER 40S CLOSER TO THE SURFACE WARM
SECTOR. SOME SHOWERS WERE ADDED TO THE GRIDS IN ADDITION TO THE
DRIZZLE ACROSS SOUTHEAST KANSAS AS HIGH RESOLUTION MODELS ARE
SUGGESTING SOME CONVECTIVE QPF DEVELOPING IN THE GREATEST ZONE OF
LOW LEVEL MOIST ADVECTION FRIDAY.
UMSCHEID
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 345 PM CST THU NOV 20 2014
THE LOW LEVEL MOIST PLUME WILL REMAIN ACROSS SOUTHEAST KANSAS
THROUGH SUNDAY AS THE SHORTWAVE TROUGH BEGINS TO LIFT NORTHEAST
THROUGH THE OZARKS. A DEFORMATION ZONE AT 700MB IS SUGGESTED TO CLIP
SOUTHEAST KANSAS, AND THIS IS WHERE POPS WILL REMAIN HIGHEST
SATURDAY NIGHT INTO SUNDAY. THE WARMING LOWER TROPOSPHERE WILL
RESULT IN ALL PRECIPITATION BEING IN THE FORM OF RAIN. A FAIRLY
STRONG FRONTAL PASSAGE IS EXPECTED SUNDAY WITH NORTHWEST WINDS IN
THE WAKE OF THIS STORM SYSTEM AT ABOUT 25 TO 30 MPH DURING THE DAY.
THE AIRMASS BEHIND THIS WAVE WILL NOT BE OF ARCTIC ORIGIN, HOWEVER,
SO TEMPERATURES SUNDAY THROUGH TUESDAY OF NEXT WEEK WILL BE FAIRLY
SEASONAL FOR LATE NOVEMBER.
UMSCHEID
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1130 PM CST THU NOV 20 2014
WITH WIDE TEMP/DWPT DIFFERENTIALS PLUS SHORT-TERM MODEL SOUNDINGS
INDICATING STRATUS NOT REACHING SC & SE KS TIL ~12Z HAVE DELAYED
ONSET OF IFR CIGS TIL CLOSER TO DAYBREAK. ONCE THESE TERMINALS
DETERIORATE TO IFR/LIFR STATUS THEY WILL REMAIN SOCKED IN THROUGH
21/06Z & LIKELY BEYOND. THE -FZDZ POTENTIAL IS HOWEVER DIMINISHING
FOR THE REST OF THE TONIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 31 41 38 55 / 20 30 20 40
HUTCHINSON 28 38 36 54 / 10 20 10 20
NEWTON 29 40 37 52 / 20 30 20 30
ELDORADO 31 41 39 55 / 20 30 30 40
WINFIELD-KWLD 34 45 42 56 / 20 30 30 50
RUSSELL 26 42 31 53 / 0 10 10 10
GREAT BEND 27 42 32 54 / 0 10 10 10
SALINA 26 40 34 53 / 10 20 10 20
MCPHERSON 28 40 35 53 / 10 20 10 20
COFFEYVILLE 35 51 46 57 / 20 40 40 60
CHANUTE 32 46 44 55 / 20 40 40 60
IOLA 30 44 43 54 / 20 40 40 60
PARSONS-KPPF 33 49 45 56 / 20 40 40 60
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1202 AM CST FRI NOV 21 2014
.AVIATION...
SEVERAL AREAS OF LIGHT RAIN CONTINUED TO SPREAD NORTHEAST OVER THE
FOUR STATE REGION TONIGHT AS WEAK DISTURBANCES RACE OVERHEAD ACROSS
A LOW LEVEL FLOW OF GULF MOISTURE AND A SURFACE BOUNDARY
STRETCHING FROM NORTHEAST TEXAS INTO NORTHEAST LOUISIANA. CEILINGS
AND VISIBILITIES VFR FOR MUCH OF THE AREA WILL GIVE WAS TO
MVFR/IFR LATER DURING THE MORNING. PARTS OF NORTH CENTRAL
LOUISIANA AND SOUTH CENTRAL ARKANSAS SLOWER TO FALL AND MAY REMAIN
MORE VFR. SOUTHERLY WINDS LIGHT AND VARIABLE WINDS OVER NORTH
CENTRAL LOUISIANA AND SOUTH CENTRAL ARKANSAS WITH SOUTH TO
SOUTHEAST WINDS 4-9 KNOTS THROUGH 21/14Z WITH WINDS INCREASING
DURING THE DAY FRIDAY WITH SPEEDS HIGHER OVER THE WESTERN SECTIONS
OF THE ARKLATEX...10-15 KNOTS. /06/
&&
.PREV DISCUSSION... /ISSUED 1000 PM CST THU NOV 20 2014/
DISCUSSION...
AS OF 0345Z...WARM FRONT WAS LOCATED ROUGHLY FROM NEAR KPRX...TO
NEAR ATLANTA TX...TO BETWEEN KELD AND KCDH. SCT SHWRS HAVE BEEN
TRYING TO DEVELOP ALONG THE FRONT. AS THE FRONT CONTINUES
NWD...MOISTURE WILL CONTINUE TO STREAM NEWD AND LIFT FROM A
SHORTWAVE TROUGH APPROACHING FROM THE WEST SHOULD RESULT IN
INCREASING COVERAGE OF SHWRS AND POSSIBLY A COUPLE OF ISOLATED
TSTMS THROUGH THE OVERNIGHT AND EARLY MORNING HRS. ALREADY
BEGINNING TO SEE SOME SIGNS OF INCREASED SHWRS ACROSS E AND SE TX
AS DRY AIR ALOFT IS ERODED AND DISPLACED EWD.
HAVE ADJUSTED POPS BASED ON LATEST RADAR TRENDS. MAINLY TO FOCUS
HIGHEST RAIN CHANCES ACROSS E TX AND TO LOWER POPS ALONG THE NRN
AND ERN FRINGES OF THE CWA THROUGH MIDNIGHT. HRRR HAS HAD A
DECENT HANDLE ON THE SHWRS SO FAR THIS EVENING SO HAVE HAVE ALSO
LOWERED POPS IN THE FAR SE ZONES AFTER MIDNIGHT.
UPDATED PRODUCTS WILL BE SENT SHORTLY. /09/
PREV DISCUSSION... /ISSUED 304 PM CST THU NOV 20 2014/
DISCUSSION...
A LITTLE SHOWER ACTIVITY IS COOLING DOWN THE AFTERNOON READINGS
WITH SOUTHWEST ARKANSAS JUST ON THE FRINGE AND MUCH OF NORTHWEST
LA SEEING LIGHT RAIN SHOWERS MOVE ON THE NORTHEAST AT 20 MPH.
OVERALL...WE SEE LOTS OF 60S AND A FEW LOW 70S SOUTH WITH STILL A
FEW 50S NORTH OF THAT WEAK BACK DOOR WHERE NORTHEAST WINDS ARE
LIGHT. THE MODIFIED GULF AIR CONTINUES NORTHWARD ON S/SW WINDS
AROUND 10 MPH WITH A FEW GUSTS OVER NE TX. THE WATER VAPOR SOME
UPPER DIVERGENCE ALOFT OVER TEXAS ON APPROACH AND SHOULD BOOST THE
COVERAGE OF SHOWERS OVERNIGHT...SOME ISOLATED THUNDER IS POSSIBLE
BUT NOTHING EVEN STRONG EXPECTED.
THE OUTLOOK FOR SATURDAY IS WARMER...BUT LATER...SO MAYBE A WASH
CONSIDERING THE ENERGY IN THE NEGATIVE TILT. AS SCATTERED
THUNDERSTORMS QUICKLY DEVELOP MID TO LATE AFTERNOON OVER DEEP
EAST TEXAS COVERAGE WILL QUICKLY INCREASE WITH GOOD VERTICAL STORM
STRUCTURE. THIS IS WHERE SPC HAS A SLIGHT RISK FOR ISOLATED
TORNADOES...DAMAGING WIND AND HAIL. THESE STORMS WILL LIKELY
CONDENSE INTO A LARGE MCS DURING THE EVENING WITH A GOOD DEAL OF
ENERGY ALOFT. DAMAGING WINDS REMAIN A THREAT ALONG WITH SOME HAIL
AS THE SYSTEM RACES EASTWARD DURING THE OVERNIGHT.
SUNDAY AND MONDAY...WE CONTINUE WITH THE WARMER TREND UNTIL THE
COLD FRONT IN THE PATTERN SWEEPS IN WITH PERHAPS A FEW TUESDAY
SHOWERS...BUT MOISTURE WILL BE LIMITED AND WE ARE DRY AS FOR NOW.
OTHERWISE...THE REST OF THE WEEK WILL BE SEASONAL AND EVEN TRENDING
COOLER IF YOU LIKE THE EURO LATE WEEK. /24/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 54 67 53 71 60 / 50 50 40 60 90
MLU 48 67 49 72 59 / 40 40 20 30 90
DEQ 49 61 52 68 55 / 50 60 60 70 90
TXK 52 63 52 68 58 / 50 60 50 60 90
ELD 47 61 50 69 57 / 50 50 40 50 90
TYR 57 68 56 69 57 / 50 60 50 80 90
GGG 56 68 55 70 58 / 50 60 50 70 90
LFK 57 70 56 71 59 / 50 60 30 70 90
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
06
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
431 PM EST FRI NOV 21 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 406 PM EST FRI NOV 21 2014
WV IMAGERY AND RUC ANALYSIS INDICATED ZONAL MID/UPPER LEVEL FLOW
THROUGH THE NW AND N CNTRL CONUS WITH A WEAK SHORTWAVE TROUGH OVER
NORTH DAKOTA. A VIGOROUS SRN STREAM SHRTWV WAS SLIDING THROUGH SW
ARIZONA. AT THE SFC...SW FLOW WAS INCREASING FROM THE UPPER MS VALLEY
INTO THE NRN LAKES AS THE PRES GRADIENT TIGHTENS BETWEEN A 995 MB LOW
OVER MANITOBA AND 1034 MB HIGH OVER THE OH VALLEY. WAA INTO THE
REGION HAS BROUGHT AN INCREASE IN MID CLOUDS ACROSS UPPER MI WITH
ANOTHER BATCH UPSTREAM FROM MN INTO CNTRL WI. THE LOWER CLOUDS
REMAINED WELL TO THE SOUTH OVER MO AND SRN IA.
TONIGHT...EXPECT THAT THE STRONG SSW LOW LEVEL WAA PATTERN WILL
RAPIDLY BRING LOW LEVEL MOISTURE TOWARD THE AREA TO SUPPORT LOWER
CLOUDS INTO THE CWA. ALTHOUGH THE LOW LEVEL ISENTROPIC LIFT WILL BE
MARGINAL TO PRODUCE PCPN...UPSLOPE FLOW INTO MUCH OF THE AREA SHOULD
BE ENOUGH TO SUPPORT SOME LIGHT PCPN...ESPECIALLY OVER THE EAST HALF
WHERE ADDITIONAL MOISTURE FROM LAKE MICHIGAN IS AVAILABLE. MODEL
SOUNDINGS SUGGEST THAT THE 3K-8K DRY/WARM LAYER WILL BE STRONG ENOUGH
TO LIMIT/PREVENT ICE CRYSTAL AVAILABILITY INTO THE LOWER MOIST LAYER.
SO...EXPECT -FZDZ WILL BE THE PREDOMINANT PCPN TYPE. EVEN THOUGH
LITTLE IF ANY MEASURABLE PCPN IS EXPECTED...EVEN A VERY THIN COATING
OF -FZDZ COULD RESULT IN HAZARDOUS CONDITIONS ON UNTREATED ROADS.
SAT...THE COMBINATION OF DAYTIME HEATING AND ADDITIONAL WAA WILL
PUSH TEMPS ABOVE FREEZING IN MOST AREAS BY NOON CHANGING ANY
LINGERING FREEZING DRIZZLE TO DRIZZLE. EXPECT THE PCPN CHANCES TO
DIMINISH AS THE LOW LEVEL WAA WEAKENS DURING THE LATE MORNING AND
AFTERNOON. OTHERWISE...TEMPS SHOULD CLIMB TO READINGS AT OR ABOVE
NORMAL IN THE MID TO UPPER 30S.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 430 PM EST FRI NOV 21 2014
A VERY ACTIVE WEEK IS IN STORE ACROSS THE UPPER GREAT LAKES AS A
POTENT MID-LEVEL SYSTEM DIGS INTO THE NORTHERN ROCKIES/PLAINS. THIS
WILL BRING A DECENT SURGE OF WARM AIR ACROSS THE AREA BY LATE
WEEKEND...BRINGING THE AREA BACK INTO ABOVE-AVERAGE TEMPERATURES FOR
A SHORT PERIOD. WITH THIS WILL COME A DECENT ROUND OF RAIN ACROSS
MAINLY CENTRAL AND EASTERN UPPER MI SUNDAY NIGHT INTO MONDAY. A
QUICK TRANSITION BACK TO WINTER WILL THEN TAKE PLACE ON MONDAY AS
THE TROUGH AND ASSOCIATED STRONG SURFACE LOW MOVE NORTHEAST OF THE
REGION...BRINGING STRONG CAA AND THE POTENTIAL FOR A DECENT SNOWFALL
ACROSS THE WESTERN CWA.
SATURDAY NIGHT...AS WEAK MID-LEVEL RIDGING WORKS ACROSS THE UPPER
GREAT LAKES...THIS LOOKS TO BE THE QUIETEST PERIOD THROUGH AT LEAST
TUESDAY. SIGNIFICANTLY DRY AIR ABOVE 900 HPA AND THE LACK OF ANY
APPRECIABLE MID/UPPER-LEVEL FORCING SHOULD LIMIT ANY DEEPER PRECIP
POTENTIAL. THE ONLY CONCERN IS A CHANCE FOR DZ/FZDZ ASSOCIATED WITH
WEAK LOW-LEVEL WAA SOUTH LATE IN THE NIGHT.
SUNDAY AND MONDAY...SIGNIFICANT CHANGES ARE SET TO BEGIN SUNDAY AS
AN ACTIVE NORTHERN AND SOUTHERN STREAM TAKE AIM ON THE UPPER GREAT
LAKES. FIRST...A LOOK AT THE LARGE SCALE PICTURE. AS THE
AFOREMENTIONED TROUGH OVER THE NORTHERN ROCKIES TRACKS ESE TOWARD
THE UPPER MS VALLEY...ANOTHER TROUGH ACROSS TX SATURDAY EVENING WILL
EJECT NE INTO THE UPPER GREAT LAKES. THE MERGING PIECES OF ENERGY
COMBINED WITH A QUICKLY DEVELOPING 120KT UPPER JET STREAK WILL
INDUCE A SFC LOW SOMEWHERE FROM EASTERN UPPER MI TO NORTHERN LOWER
MI BY 12Z MONDAY.
UPPER MI FINDS ITSELF CAUGHT IN A CONVOLUTED PATTERN SUNDAY MORNING
BEFORE THE TWO SYSTEMS CONSOLIDATE OVER THE AREA. OVERALL SYNOPTIC
FORCING REMAINS LIMITED TO START THE DAY...BUT LOW-LEVEL MOISTURE
TRANSPORT RESULTING IN A DEEPENING MOIST LAYER WILL ALLOW FOR
INCREASING CHANCES OF FZDZ/DZ IN THE MORNING...AND RAIN THROUGHOUT
THE AFTERNOON. BEST CHANCES DURING THE DAY LOOK TO BE ACROSS THE
CENTRAL AND EASTERN CWA WITH UPSLOPE AND MOISTURE INFLUENCES FROM SE
WINDS OFF LAKE MI. TEMPS THROUGH THE MOIST LAYER WILL REMAIN WARM
ENOUGH FOR SUPER-COOLED LIQUID...INTRODUCING CONTINUED CONCERN FOR
FZDZ/FZRA IN THE MORNING. GIVEN OUR RECENT SUB-FREEZING
STRETCH...CLEARED ROADS MAY SEE SOME ICING EVEN AS TEMPS WARM INTO
THE 30S TO LOW 40S DURING THE DAY SUNDAY. LATEST MDOT ROAD SENSORS
ARE SHOWING SUB-FREEZING TEMPS DOWN AT LEAST 24 INCHES BELOW THE
ROAD AND SUB-20F TEMPS DOWN TO AT LEAST 6 INCHES FOR NEARLY ALL
UPPER MI HIGHWAYS. WILL THEREFORE EXTEND THE FZDZ/FZRA POTENTIAL
THROUGH SUNDAY MORNING UNTIL AIR TEMPS WARM WELL-ABOVE FREEZING
SUNDAY AFTERNOON.
SIGNIFICANT MOISTURE TRANSPORT/ISENTROPIC LIFT WILL FOCUS ACROSS THE
EAST HALF OF THE CWA LATE SUNDAY AFTERNOON THROUGH MUCH OF THE
NIGHT. MEANWHILE...DECENT LIFT UNDER THE RIGHT ENTRANCE OF THE UPPER
JET WILL SPREAD ACROSS THE AREA. THIS SHOULD BRING WIDESPREAD PRECIP
OVER THE ENTIRE CWA THROUGHOUT THE NIGHT. WARMING TEMPS THROUGHOUT
THE COLUMN WILL RESULT IN A PTYPE OF ALL RAIN FOR THE ENTIRE CWA
SUNDAY AFTERNOON AND EVENING...AND ALL BUT THE WESTERN CWA LATE
SUNDAY NIGHT. WITH THE DECENT FORCING AND SUFFICIENT
MOISTURE...RAINFALL AMOUNTS LATE SUNDAY AFTERNOON THROUGH MONDAY
MORNING ARE EXPECTED TO SURPASS 0.75IN ACROSS THE EAST HALF. THIS
MAY BE A LITTLE CONSERVATIVE...BUT WOULD LIKE TO SEE BETTER
MID-LEVEL SUPPORT IN CONJUNCTION WITH THE UPPER JET BEFORE
INCREASING PRECIP AMOUNTS ANY FURTHER.
LATE SUNDAY NIGHT INTO MONDAY STARTS THE TRANSITION BACK TO SNOW AS
THE SFC LOW REACHES EASTERN UPPER MI LATE SUNDAY NIGHT. AS THE
SOUTHERN AND NORTHERN STREAM MERGE...THE NEW DEEPER TROUGH NEARLY
STALLS OVER THE UPPER GREAT LAKES. AN IMPRESSIVE 140KT UPPER JET
OVER THE MID MS VALLEY COMBINED WITH THE DEPARTING 120KT JET MOVING
OVER QUEBEC WILL BE ENOUGH TO KEEP A DEEPER SFC LOW OVER
ONTARIO/QUEBEC. MEANWHILE...A COMPACT TROUGH NEAR SEATTLE SUNDAY
AFTERNOON WILL DIG INTO THE DEPARTING THE TROUGH...FURTHER SLOWING
ITS MOVEMENT. ALL OF THIS COMES TOGETHER TO PRODUCE A LAGGING
LOW-LEVEL TROUGH AND DEFORMATION ZONE OVER UPPER MI ON MONDAY AND
MONDAY NIGHT. WITH LAKE ENHANCEMENT KICKING IN WITH N/NNW
WINDS...THERE IS INCREASING POTENTIAL FOR MODERATE TO POSSIBLY HEAVY
SNOW ACROSS THE NORTHWEST HALF OF UPPER MI. THE 12Z NAM AND 12Z GFS
HAVE BOTH COME IN WITH MUCH HIGHER QPF ACROSS THE WESTERN AND
CENTRAL CWA ON MONDAY. THOUGH THE ECMWF TAKES THE LOW ACROSS
NORTHERN LOWER MI...THE MID/UPPER-LEVEL SUPPORT PAINTS HIGHER QPF
AMOUNTS ACROSS THE WESTERN CWA AS WELL. THE TRANSITION TO SNOW
SHOULD BE UNDERWAY ACROSS THE FAR WEST BY DAYBREAK MONDAY...THEN
CONTINUE PRESSING EASTWARD. BY EARLY AFTERNOON...ALL BUT SOME OF THE
SHORELINE LOCATIONS OF THE WEST HALF SHOULD CHANGE OVER TO SNOW.
WHILE THERE IS SOME UNCERTAINTY IN HOW QUICK SNOW RATIOS INCREASE
DURING THE DAY...SEVERAL INCHES OF SNOW SHOULD FALL FOR MOST OF THE
NW HALF OF THE CWA MONDAY AFTERNOON. DO NOT WANT TO COMPLETELY JUMP
ON BOARD WITH THE NEW GUIDANCE QUITE YET...BUT THERE IS ENOUGH
EVIDENCE TO AT LEAST INCREASE SNOW AMOUNTS A BIT. THE EASTERN CWA
SHOULD SEE AT LEAST SOME ACCUMULATIONS...BUT A LATER TRANSITION TO
ALL SNOW COMBINED WITH A LESS FAVORABLE LOCATION OF THE FORCING WILL
KEEP AMOUNTS LOWER. WILL NEED TO MONITOR THIS OVER THE NEXT COUPLE
DAYS AS AT LEAST SOME WINTER WX HEADLINES MAY BE NEEDED.
MONDAY NIGHT AND TUESDAY...MOISTURE CONTINUING TO WRAP AROUND
THE BACKSIDE OF THE DEPARTING LOW COMBINED WITH UPSLOPE AND LAKE
INFLUENCE WILL GENERATE SNOW FOR THE N TO NNW WIND SNOW BELTS.
ANOTHER SEVERAL INCHES OF SNOW WILL BE POSSIBLE MONDAY NIGHT. BY
TUESDAY...SOME DRIER AIR WILL BEGIN TO WORK IN FROM THE WEST AS
INVERSION HEIGHTS FALL BELOW 5KFT...CUTTING OFF MUCH OF THE RESIDUAL
LAKE EFFECT PRECIP.
WEDNESDAY THROUGH FRIDAY...ANOTHER TROUGH DIGGING OUT OF
NORTH-CENTRAL CANADA WILL MOVE SE ACROSS THE UPPER GREAT LAKES
TUESDAY NIGHT INTO WEDNESDAY. ACCUMULATING SNOW WILL BE POSSIBLE
WEDNESDAY WITH THIS SYSTEM...BUT ITS TRACK AND STRENGTH ARE TOO
VARIABLE IN THE MODELS TO PIN DOWN LOCATIONS AT THIS TIME. MUCH
COLDER AIR ARRIVES BEHIND THE LOW AND INDUCES LES FOR THE NNW WIND
SNOW BELTS WEDNESDAY NIGHT THROUGH THANKSGIVING. A SLOWLY MODERATING
850 HPA AIRMASS WITH TEMPS -15 TO -20C WILL RESULT IN THE WEATHER
FEELING MORE LIKE CHRISTMAS THAN THANKSGIVING AS HIGHS STRUGGLE TO
GET OUT OF THE TEENS FOR AT LEAST THE WEST AND CENTRAL. BY
FRIDAY...ANOTHER PATTERN CHANGE WILL BRING MODERATING CONDITIONS TO
END THE WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 246 PM EST FRI NOV 21 2014
MID CLOUDS WITH GUSTY SSW WINDS PREVAILED THIS AFTRNOON AS WARM
ADVECTION TAKES OVER BETWEEN LOW PRESSURE OVER THE PLAINS AND HIGH
PRES OVER THE OH VALLEY. LLWS IS EXPECTED AS THE LOW LEVEL JET
REALLY INCREASES 1-2KFT ABOVE THE SURFACE...ESPECIALLY AT KSAW. HAVE
LEFT GUSTS UP TO ACCOUNT FOR THIS. MVFR CLOUDS WILL BE PUSHING
NORTH-NORTHEAST INTO THE AREA TONIGHT. THIS WILL LEAD TO A QUICK
DROP IN CEILINGS LATE TONIGHT...WITH KSAW HAVING THE LOWEST VALUES
THAT SHOULD FALL INTO THE IFR RANGE LATE. WITH THESE LOW
CLOUDS...THERE IS THE POTENTIAL FOR LIGHT FREEZING DRIZZLE LATE
TONIGHT...ESPECIALLY AT KSAW.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 406 PM EST FRI NOV 21 2014
WINDS WILL CONTINUE TO INCREASE WITH A TIGHT PRES GRADIENT BETWEEN
LOW PRES OVER THE PLAINS AND A RIDGE OVER THE OH VALLEY.
WINDS TOT 30KTS WITH FREQUENT GALE FORCE GUSTS TO 35 KNOTS ARE
EXPECTED TONIGHT. THE PRESSURE GRADIENT WILL DECREASE SATURDAY INTO
SATURDAY NIGHT AS A TROUGH TRAILING THE CANADIAN LOW DROPS SOUTHEAST
OVER LAKE SUPERIOR. A DEVELOPING LOW IN THE CENTRAL/SOUTHERN PLAINS
ON SATURDAY NIGHT WILL LIFT NORTHEAST THROUGH THE GREAT LAKES REGION
TO NEAR THE STRAITS MONDAY MORNING AT AROUND 28.9 INCHES. AS THE LOW
LIFTS TO THE NORTHEAST ON MONDAY NORTHERLY GALES ARE LIKELY WHICH
COULD PERSIST THROUGH MONDAY NIGHT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 7 AM EST SATURDAY FOR LSZ266-267.
GALE WARNING UNTIL 7 AM EST /6 AM CST/ SATURDAY FOR LSZ162-263-
264.
LAKE MICHIGAN...
GALE WARNING UNTIL 10 AM EST SATURDAY FOR LMZ248.
&&
$$
SHORT TERM...JLB
LONG TERM...KLUBER
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
411 PM EST FRI NOV 21 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 406 PM EST FRI NOV 21 2014
WV IMAGERY AND RUC ANALYSIS INDICATED ZONAL MID/UPPER LEVEL FLOW
THROUGH THE NW AND N CNTRL CONUS WITH A WEAK SHORTWAVE TROUGH OVER
NORTH DAKOTA. A VIGOROUS SRN STREAM SHRTWV WAS SLIDING THROUGH SW
ARIZONA. AT THE SFC...SW FLOW WAS INCREASING FROM THE UPPER MS VALLEY
INTO THE NRN LAKES AS THE PRES GRADIENT TIGHTENS BETWEEN A 995 MB LOW
OVER MANITOBA AND 1034 MB HIGH OVER THE OH VALLEY. WAA INTO THE
REGION HAS BROUGHT AN INCREASE IN MID CLOUDS ACROSS UPPER MI WITH
ANOTHER BATCH UPSTREAM FROM MN INTO CNTRL WI. THE LOWER CLOUDS
REMAINED WELL TO THE SOUTH OVER MO AND SRN IA.
TONIGHT...EXPECT THAT THE STRONG SSW LOW LEVEL WAA PATTERN WILL
RAPIDLY BRING LOW LEVEL MOISTURE TOWARD THE AREA TO SUPPORT LOWER
CLOUDS INTO THE CWA. ALTHOUGH THE LOW LEVEL ISENTROPIC LIFT WILL BE
MARGINAL TO PRODUCE PCPN...UPSLOPE FLOW INTO MUCH OF THE AREA SHOULD
BE ENOUGH TO SUPPORT SOME LIGHT PCPN...ESPECIALLY OVER THE EAST HALF
WHERE ADDITIONAL MOISTURE FROM LAKE MICHIGAN IS AVAILABLE. MODEL
SOUNDINGS SUGGEST THAT THE 3K-8K DRY/WARM LAYER WILL BE STRONG ENOUGH
TO LIMIT/PREVENT ICE CRYSTAL AVAILABILITY INTO THE LOWER MOIST LAYER.
SO...EXPECT -FZDZ WILL BE THE PREDOMINANT PCPN TYPE. EVEN THOUGH
LITTLE IF ANY MEASURABLE PCPN IS EXPECTED...EVEN A VERY THIN COATING
OF -FZDZ COULD RESULT IN HAZARDOUS CONDITIONS ON UNTREATED ROADS.
SAT...THE COMBINATION OF DAYTIME HEATING AND ADDITIONAL WAA WILL
PUSH TEMPS ABOVE FREEZING IN MOST AREAS BY NOON CHANGING ANY
LINGERING FREEZING DRIZZLE TO DRIZZLE. EXPECT THE PCPN CHANCES TO
DIMINISH AS THE LOW LEVEL WAA WEAKENS DURING THE LATE MORNING AND
AFTERNOON. OTHERWISE...TEMPS SHOULD CLIMB TO READINGS AT OR ABOVE
NORMAL IN THE MID TO UPPER 30S.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 526 AM EST FRI NOV 21 2014
BIG CHANGES ARE STILL EXPECTED DURING THE LONG TERM PORTION OF THE
FCST. THE HIGHLY AMPLIFIED PATTERN THAT HAS BROUGHT PERSISTENTLY
MUCH BLO NORMAL TEMPS INTO THE UPPER GREAT LAKES WILL RELAX
SIGNIFICANTLY OVER THE NEXT COUPLE OF DAYS AS A STRONG WAVE PLOWS
INTO THE PAC NW FORCING THE TROUGH OUT FM ERN NORTH AMERICA. THIS
CHANGE OCCURS QUICKLY AS MODELS SHOW 220-240M 500MB HEIGHT RISES
OVER UPPER MI THIS MORNING AHEAD OF BUILDING RIDGE FM THE PLAINS.
SO...AFTER AN UNSEASONABLY LONG STRETCH OF COLD WEATHER FOR NOV
(RECORD BREAKING SUBFREEZING STREAK AT NWS MQT FOR NOV AND ALSO 6
CONSECUTIVE DAYS OF RECORD LOW MAX TEMPS)...EXPECT A QUICK
TRANSITION BACK TO NORMAL/ABOVE NORMAL TEMPS THIS WEEKEND. THE
STRONG PACIFIC SHORTWAVE SURGING INTO THE WRN CONUS WILL CARVE OUT A
SIGNIFICANT SRN STREAM TROF THIS WEEKEND LEADING TO THE DEVELOPMENT
OF A RAPIDLY DEEPENING SFC LOW LIFTING FROM NORTH TX SUN MORNING TO
NEAR THE MACKINAC STRAITS BY MONDAY WITH PRES BOTTOMING OUT IN THE
HIGH 970S MB OVER THE UPPER LAKES. WITH SIGNIFICANT WARMING
ANTICIPATED AHEAD OF THE DEEPENING SFC LOW...RAIN WILL OCCUR ON
SUNDAY AHEAD OF THE STORM SYSTEM WITH MODERATE PCPN AMOUNTS POSSIBLE
OVER THE CENTRAL AND ERN CWA. AS COLDER AIR WRAPS INTO THE AREA ON
THE BACKSIDE...THERE WILL BE A TRANSITION BACK TO SNOW ON MON WITH
THE POTENTIAL FOR MODERATE TO HEAVY SNOW ACCUMULATIONS INTO
TUE...MAINLY NEAR LAKE SUPERIOR. AFTER THIS WEEKENDS WARMUP...MODELS
POINT TOWARD A COLD PATTERN BECOMING RE-ESTABLISHED NEXT WEEK AS
HEIGHTS RISE AGAIN OVER WRN NORTH AMERICA/NE PACIFIC. THIS WILL
ALLOW FOR ARCTIC AIR TO SPILL S TOWARD THE CENTRAL CONUS/GREAT LAKES
REGION AGAIN. MANY OF THE MODELS CONTINUE TO INDICATE THE COLDEST
AIR OF THE SEASON (WELL BLO -20C 8H TEMPS) DROPPING SE INTO THE
UPPER GREAT LAKES TOWARD THE END OF NEXT WEEK. WHETHER THIS COLD
PATTERN WILL AGAIN BECOME PERSISTENT LIKE WHAT WE`VE SEEN THIS PAST
WEEK REMAINS TO BE SEEN...BUT THERE IS RECENT SUPPORT FROM THE NAEFS
AND CFSV2 RUNS THAT COLDER THAN NORMAL CONDITIONS COULD PERSIST INTO
EARLY DECEMBER.
BEGINNING SAT...WITH INCREASING ISENTROPIC ASCENT IN STRENGTHENING
WSW FLOW BETWEEN HIGH PRES MOVING OFF THE E COAST AND LOW PRES
MOVING ACROSS SCNTRL CANADA...SOME OF THE MODELS GENERATE SOME VERY
LIGHT PCPN OVER THE ERN FCST AREA ON SAT WHERE ISENTROPIC ASCENT IS
MAXIMIZED. HOWEVER...PERSISTENCE OF DRIER AIR IN THE 850-700MB LAYER
AS NOTED ON THE 00Z GFS/NAM BUFR SOUNDINGS WARRANTS NOTHING MORE
THAN SCHC POPS TO LOW CHC POPS SAT. GIVEN DRYNESS NOTED IN MID-LVLS
AND THE SFC BASED MOIST LAYER WARMER THAN -10C...PCPN MAY END UP
MOSTLY AS -DZ/-FZDZ IF ANY PCPN DOES OCCUR. EXPECT TEMPS ON SAT TO
RISE ABOVE FREEZING EVERYWHERE.
SAT NIGHT...WEAK HEIGHT RISES AND FAIRLY DRY AIRMASS SUGGEST MOSTLY
DRY CONDITIONS. WITH LIGHTER WINDS UNDER DRIER MID LEVELS...EXPECT
MIN TEMPS TO FALL INTO THE 20S TO AROUND 30F IN GENERAL.
SUN INTO MON...MODELS CONTINUE TO INDICATE LOW PRES DEVELOPING OVER
THE SRN PLAINS SAT NIGHT/SUN MORNING IN RESPONSE TO THE STRONG
PACIFIC SHORTWAVE DIGGING INTO THE BASE OF THE SRN STREAM TROUGH.
MEANWHILE...ADDITIONAL ENERGY MOVING OUT OVER THE NRN PLAINS WILL
HELP PULL THIS SYSTEM NORTH AND WITH THE SUBSEQUENT PHASING THE SFC
LOW IS EXPECTED TO DEEPEN INTO THE 970S MB BY THE TIME IT REACHES
THE UPPER LAKES MON MORNING. THE GFS HAS BEEN REMARKABLY CONSISTENT
FOR SEVERAL RUNS NOW SHOWING AROUND 980 MB SFC LOW TRACKING TO NEAR
MACKINAC STRAITS BY 12Z MON. THE 12Z ECMWF RUN HAD TRENDED FARTHER
EAST TOWARD THE GFS SOLN TRACK AND THE LATEST 00Z RUN SHOWS A
SIMILAR TRACK AND A BIT QUICKER SOLN SIMILAR TO THE 00Z GFS RUN. THE
GEM-NH HAS ALSO SHOWN A SIMILAR TRACK TO THE GFS BUT AGAIN WAS
SOMEWHAT SLOWER LIKE THE ECMWF BUT NOT QUITE AS DEEP. ALL MODELS
SUGGEST THAT PCPN ON THE FRONT SIDE OF THIS SYSTEM WILL BE ALL RAIN
FOR UPPER MI ON SUNDAY. HOWEVER...NOT OUT OF THE QUESTION THAT THERE
COULD BE A LITTLE -FZRA AT THE ONSET SUNDAY MORNING IF TEMPS ARE
STILL CLOSE TO FREEZING WHEN PCPN BEGINS. OTHERWISE...MODELS FAIRLY
CONSISTENT SHOWING BEST SURGE OF RAIN INTO UPPER MI LATE SUN
MORNING/AFTN AND CONTINUING SUN NIGHT. EXPECT AT LEAST MODERATE PCPN
RANGING FROM .25 FAR WEST TO AROUND AN INCH EAST AND SOUTH CENTRAL
WHERE MOISTURE TRANSPORT WILL BE STRONGER/MORE SUSTAINED NEAR TRACK
OF SFC LOW.
AS THE SYSTEM LIFTS NNE AND THE COLUMN COOLS UNDER FALLING
HEIGHTS...MODELS INDICATE DEFORMATION/COMMA HEAD PCPN SHIELD
DEVELOPING. THE FCST CHALLENGE WILL BE DETERMINING THE STRENGTH AND
PERSISTENCE OF THIS DEFORMATION PCPN SHIELD AND WHERE IT WILL SET
UP. 00Z MODELS STILL SHOW PLENTY OF DIFFERENCES IN THIS REGARD WHICH
WILL BE CRITICALLY IMPORTANT IN DETERMINING POTENTIAL FOR MODERATE
TO HEAVY SNOW BEHIND THE SYSTEM. THE 00Z ECMWF SHOWS A BETTER
DEFINED DEFORMATION PCPN SHIELD THAN EITHER THE GFS OR GEM-NH. WITH
850MB TEMPS COOLING TO AROUND -12C BY 00Z TUE...LAKE ENHANCEMENT
WILL ALSO COME INTO PLAY. SO AFTER THE RAIN ON SUN/SUN NIGHT...STILL
BELIEVE THERE WILL BE A POTENTIAL FOR MODERATE TO POTENTIALLY HEAVY
SNOW OVER WRN UPPER MI MON AFTN INTO MON NIGHT ALONG WITH BLUSTERY
NW WINDS AND WILL CONTINUE TO HIGHLIGHT IN HWO AND EHWO GRIDS. THE
SNOW/WIND WILL SPREAD INTO THE ERN FCST AREA AS WELL...BUT WITH
DEFORMATION PCPN TENDING TO LIFT NE...SNOWFALL WILL LIKELY BE
LIGHTER THAN OVER THE W.
WITH 850MB TEMPS AROUND -14C TUE...NW FLOW LAKE ENHANCEMENT WILL
TRANSITION TO PURE LES AS TROF SHIFTS E AND DEEP MOISTURE DEPARTS.
WITH A TREND TOWARD MORE ANTICYCLONIC FLOW...THERE WILL BE A
DIMINISHING OF LES THRU THE DAY NEAR THE LAKE.
HEADING INTO WED/THU...SOME OF THE MODELS...PARTICULARLY THE
ECMWF...SHOW INDICATIONS OF A CLIPPER TYPE SHORTWAVE BRINGING A
POTENTIAL PERIOD OF -SN...FOLLOWED BY A SURGE OF COLDER AIR AND
RENEWED LES HEADING INTO THANKSGIVING. HOWEVER...GIVEN THAT THERE
IS STILL INCONSISTENCY WITH THE MODELS REGARDING TIMING/TRACK OF
CLIPPER SYSTEM WILL CONTINUE TO UTILIZE A CONSENSUS APPROACH WHICH
KEEPS POPS HIGHEST NEAR LAKE SUPERIOR.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 246 PM EST FRI NOV 21 2014
MID CLOUDS WITH GUSTY SSW WINDS PREVAILED THIS AFTRNOON AS WARM
ADVECTION TAKES OVER BETWEEN LOW PRESSURE OVER THE PLAINS AND HIGH
PRES OVER THE OH VALLEY. LLWS IS EXPECTED AS THE LOW LEVEL JET
REALLY INCREASES 1-2KFT ABOVE THE SURFACE...ESPECIALLY AT KSAW. HAVE
LEFT GUSTS UP TO ACCOUNT FOR THIS. MVFR CLOUDS WILL BE PUSHING
NORTH-NORTHEAST INTO THE AREA TONIGHT. THIS WILL LEAD TO A QUICK
DROP IN CEILINGS LATE TONIGHT...WITH KSAW HAVING THE LOWEST VALUES
THAT SHOULD FALL INTO THE IFR RANGE LATE. WITH THESE LOW
CLOUDS...THERE IS THE POTENTIAL FOR LIGHT FREEZING DRIZZLE LATE
TONIGHT...ESPECIALLY AT KSAW.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 406 PM EST FRI NOV 21 2014
WINDS WILL CONTINUE TO INCREASE WITH A TIGHT PRES GRADIENT BETWEEN
LOW PRES OVER THE PLAINS AND A RIDGE OVER THE OH VALLEY.
WINDS TOT 30KTS WITH FREQUENT GALE FORCE GUSTS TO 35 KNOTS ARE
EXPECTED TONIGHT. THE PRESSURE GRADIENT WILL DECREASE SATURDAY INTO
SATURDAY NIGHT AS A TROUGH TRAILING THE CANADIAN LOW DROPS SOUTHEAST
OVER LAKE SUPERIOR. A DEVELOPING LOW IN THE CENTRAL/SOUTHERN PLAINS
ON SATURDAY NIGHT WILL LIFT NORTHEAST THROUGH THE GREAT LAKES REGION
TO NEAR THE STRAITS MONDAY MORNING AT AROUND 28.9 INCHES. AS THE LOW
LIFTS TO THE NORTHEAST ON MONDAY NORTHERLY GALES ARE LIKELY WHICH
COULD PERSIST THROUGH MONDAY NIGHT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 7 AM EST SATURDAY FOR LSZ266-267.
GALE WARNING UNTIL 7 AM EST /6 AM CST/ SATURDAY FOR LSZ162-263-
264.
LAKE MICHIGAN...
GALE WARNING UNTIL 10 AM EST SATURDAY FOR LMZ248.
&&
$$
SHORT TERM...JLB
LONG TERM...VOSS
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION...UPDATED
NWS TWIN CITIES/CHANHASSEN MN
628 PM CST SAT NOV 22 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 238 PM CST SAT NOV 22 2014
MAIN CONCERN DURING THE SHORT TERM PERIOD IS THE TREND OF STRATUS
AND THE POTENTIAL EXTENT OF FOG TONIGHT. A SECONDARY CONCERN IS WITH
PRECIP POTENTIAL TONIGHT INTO SUNDAY...THOUGH MODELS CONTINUE TO
SHOW PRECIP AMOUNTS BEING PRETTY UNDERWHELMING THROUGH SUNDAY ACROSS
THE ENTIRE MPX AREA...WITH DEEPER MOISTURE GOING ACROSS ERN WI AND
MICHIGAN.
EXTENSIVE STRATUS ACROSS ALL BUT THE NW PORTION OF THE MPX CWA HAS
HELD TEMPERATURES IN CHECK ALL DAY. LOOKING TO THE SOUTH...THERE ARE
A COUPLE OF MOISTURE SURGES HEADING OUR WAY. THE FIRST IS QUICKLY
MOVING INTO NRN IA AND WILL LIKELY BE TO THE I-90 CORRIDOR BY 00Z
THIS EVENING. IT IS CHARACTERIZED BY DEWPS IN THE 40S AND MORE
CONCERNING FOR THE CLOUD FORECAST TONIGHT...CLEAR SKIES. THE SECOND
MOISTURE SURGE IS JUST NOW GETTING TO I-80 AND IT IS ASSOCIATED WITH
DEWPS IN THE 50S...AND A RETURN TO LIFR STRATUS AND FOG. THE
ECMWF/GEM SHOW THIS SECOND MOISTURE SURGE AND ITS ASSOCIATED LOWER
50 DEWPS GETTING CLEAR UP TO I-90 SUNDAY MORNING BEFORE GETTING
SHUNTED OFF TO THE EAST. CERTAINLY DEWPS IN THE 40S WITH SNOW ON THE
GROUND FAVORS STRATUS CONTINUING THROUGH THE NIGHT AND THE CURRENT
FORECAST CERTAINLY READS THAT WAY...BUT WE WILL HAVE WATCH HOW THAT
CLEARING EVOLVES.
FOR FOG...ONE THING WE ARE POSITIVE ABOUT IS IT WILL BE HAZY TROUGH
THE NIGHT GIVEN DEWPS ABOVE FREEZING WITH SNOW ON THE GROUND. THERE
WAS TALK OF A DENSE FOG ADVISORY...BUT NOT CONFIDENT ENOUGH ON WHERE
TO PUT ONE OTHER THAN ANYONE UNDER STRATUS NOW...WHICH IS JUST ABOUT
OUR ENTIRE CWA AND DID NOT WANT TO ISSUE SUCH A LARGE ADVY AT THIS
POINT. ON TOP OF THAT...WE WILL BE MAINTAINING 8-12 KT WINDS THROUGH
THE NIGHT...SO THAT WILL SUPPLY A CERTAIN DEGREE OF MIXING AS WELL.
NOT TO MENTION WE HAVE THAT CLEARING RACING NORTH OUT OF IA. AT THIS
POINT...HIGHEST CONFIDENCE IN DENSE FOG IS WHERE OUR DEEPEST SNOW
RESIDES ACROSS THE NRN MPX CWA. THE HRRR WOULD SUPPORT THIS IDEA AS
IT DOES SHOW VSBYS IMPROVING THROUGH THE NIGHT ACROSS SRN MN AS THAT
SLUG OF SLIGHTLY DRIER AIR ACROSS IA WORKS INTO MN.
FOR TEMPERATURES...THEY MAY GO NOTHING BUT UP THROUGH THE NIGHT.
FIRST RUN OF THE HOURLY TEMPERATURE TOOL WITH THE LOCAL SUPERBLEND
BROUGHT A TEMPERATURE OF 53 TO ALBERT LEA BY 7Z TONIGHT. DID NOT GO
QUITE THAT AGGRESSIVE...BUT DO THINK MUCH OF THE AREA EAST OF A NEW
ULM TO MORA LINE WILL RISE INTO THE 40S OVERNIGHT. GIVEN THE MILD
START...ALSO GAVE HIGHS SUNDAY A BIT OF AN UPWARD NUDGE TO ABOUT A
50/50 BLEND BETWEEN THE PREVIOUS FORECAST AND THE 22.12 GEM/ECMWF.
THE GEM/ECMWF SHOW HIGHS IN THE LOW 50S FOR SE MN/WRN WI TOMORROW.
GIVEN THE EXTENSIVE CLOUD COVER...DO NOT THINK WE WILL GET THAT
HIGH...BUT DO HAVE HIGHS INTO THE MID/UPPER 40S FOR ALL BUT WRN AND
CENTRAL MN.
FOR PRECIP...THAT CONTINUES TO LOOK UNDERWHELMING. OUR BIGGEST
PROBLEM THROUGH TONIGHT CONTINUES TO BE THE FACT THAT THE ATMO CAN
NOT TAKE ON MUCH MORE MOISTURE BELOW 900 MB...BUT ABOVE THAT...ITS
BONE DRY. CONTINUED TO RUN WITH HIGHEST POPS SUNDAY OUT IN ERN AREAS
AS THEY WILL BE CLOSER TO THE H85 MOISTURE TRANSPORT...BUT LIKING
THE IDEA THE GFS/SREF/NMM/ARW SHOW OF A NARROW BAND OF RAIN CENTERED
ON FGEN IN THE H7-H6 LAYER COMING OUT OF SODAK TONIGHT AND WORKING
ACROSS SRN MN THROUGH SUNDAY MORNING. THE 22.18 HOPWRF MEMBERS ALSO
SHOW THIS BAND OF PRECIP BY 9Z /THE END OF THOSE RUNS/ MOVING INTO
THE WRN PORTION OF THE FSD FORECAST AREA...SIMILAR TO WHAT THE
MODELS MENTIONED ABOVE SHOW. DID BOOST POPS IN SW MN INTO THE HIGH
CHANCE CATEGORY SUNDAY MORNING FOR NOW. THIS MAY VERY WILL END UP
BEING THE BEST CHANCE AT SEEING MEASURABLE PRECIP WITH THIS SYSTEM
FOR MUCH OF OUR MN FORECAST AREA.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 238 PM CST SAT NOV 22 2014
SUNDAY NIGHT THROUGH MONDAY WILL BRING A PERIOD OF STRONG WINDS
AND LIGHT PRECIPITATION TO THE FORECAST AREA...IN THE WAKE OF A
DEEPENING MID LATITUDE CYCLONE. THE STRONGEST WINDS ARE EXPECTED
ACROSS THE WESTERN FORECAST AREA AND THE HIGHEST POTENTIAL FOR
ACCUMULATING SNOW REMAINS ACROSS FAR EASTERN MN...BUT ESPECIALLY
IN WEST CENTRAL WI.
BY 00Z MONDAY...RAPID CYCLOGENESIS WILL BE ONGOING IN THE MID
MISSISSIPPI RIVER VALLEY IN RESPONSE TO A DEEP TROUGH DIGGING IN
ACROSS THE CENTRAL CONUS AND A LARGE AREA OF 120-150M 500MB 12-HR
HEIGHTS FALLS MOVING ACROSS THE AREA. THE AMOUNT OF DEEPENING IS
STILL QUITE VARIABLE DEPENDING ON WHICH 12Z SOLUTION ONE CHOOSES TO
FOLLOW. THE 22.12Z GFS IS BY FAR AND AWAY THE MOST AGGRESSIVE IN
STRENGTHENING THE LOW OVER THE SOUTHERN HALF OF LAKE MICHIGAN BY
06Z MONDAY TO 975MB...969MB OVER NORTHERN MICHIGAN BY 12Z...AND
966MB AS IT MOVES NORTH OF THE GREAT LAKES BY 18Z. THE NAM AND
ECMWF SEEM MORE REASONABLE WITH A BIT MORE MODEST DEEPENING.
TYPICALLY...THE KIND OF DEEPENING THE GFS IS SHOWING ONLY OCCURS
WITH VERY STRONG BAROCLINICITY AND/OR A NEGATIVELY TILTED UPPER
TROUGH. WE REALLY DON`T HAVE EITHER. THERE IS STRONG COLD
ADVECTION AND A DECENT TEMPERATURE GRADIENT ACROSS THE MID/UPPER
MISSISSIPPI VALLEY...BUT THEY SEEM MORE IN LINE WITH THE NAM/ECMWF
THAT ARE BIT MORE PROGRESSIVE WITH THE LOW AND NOT AS WOUND UP.
THEREFORE...WE DID NOT JUMP ON THE GFS SNOWFALL FORECAST THAT
WOULD GIVE 6-8" TO PORTIONS OF WEST CENTRAL WI. WE THINK THE
HEAVIEST PRECIP SHOULD BE EAST OF THE FORECAST AREA AND THE
DYNAMIC COOLING ON THE BACK SIDE OF THE LOW WILL BE WEAKER THAN
THE GFS INDICATES. IT IS NOTABLE THAT THE 22.15Z SREF AND GEM ALSO
SHOW THE POTENTIAL FOR SEVERAL INCHES OF SNOW NEAR OR JUST EAST OF
THE FORECAST AREA. THIS IS SOMETHING TO FOLLOW OVER THE NEXT 12-18
HOURS...BUT WE SIMPLY DIDN`T HAVE ENOUGH CONFIDENCE TO ISSUE A
WINTER STORM WATCH AT THIS POINT. FURTHERMORE...EVEN WITH THE
EXPECTED STRONG WINDS...THE WARM TODAY HAS LIKELY LIMITED THE
AMOUNT OF SNOW AVAILABLE FOR BLOWING AND DRIFTING. THERE WERE A
LOT OF HIGHS IN THE UPPER 30S AND LOWER 40S IN WESTERN MN TODAY.
THE NEXT SYSTEM TO WATCH ARRIVES ON WEDNESDAY AND THERE IS AGAIN
SIGNIFICANT DIFFERENCES BETWEEN THE GFS AND ECMWF. THE ECMWF HAS A
POTENT CLIPPER SYSTEM WITH 1-4" OF SNOW...IMPRESSIVE COLD
ADVECTION AND A TIGHT PRESSURE GRADIENT ON THE BACK SIDE OF THE
SYSTEM. THE 22.12Z ECMWF HAS SUSTAINED 25-30KTS NEAR THE ND/SD/MN
BORDER EARLY WEDNESDAY MORNING - QUITE IMPRESSIVE GIVEN ITS
COARSER RESOLUTION. THE GFS HAS A WEAK SURFACE TROUGH AND MUCH
LESS LIFT. THIS MID WEEK SYSTEM PRETTY MUCH LOCKS IN OUR CHANCE
FOR A WELL BELOW NORMAL THANKSGIVING. IT LOOKS VERY COLD.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 559 PM CST SAT NOV 22 2014
IFR CONDITIONS OR LOWER EXPECTED AREAWIDE THIS EVENING...ALTHOUGH
CONDITIONS HAVE IMPROVED OVER CENTRAL IOWA/SOUTHWESTERN MN AND
THAT DRIER AIRMASS COULD WORK INTO THE REST OF SOUTHERN MINNESOTA
LATE THIS EVENING. MOST OF THE MODELS SHOW THIS DRIER AIR
PROGRESSION STALLING OVER EAST CENTRAL MN AND WEST CENTRAL WI
THROUGH SUNDAY MORNING...SO CONTINUED A PESSIMISTIC FORECAST FOR
MSP...STC...RNH...AND EAU THROUGH MUCH OF THE MORNING. SUCH DRIER
AIR HAS ALREADY REACHED RWF WHERE CIGS HAVE DISAPPEARED...AND MAY
SEE SOME IMPROVEMENT AT AXN LATE TONIGHT.
KMSP...IFR CONDITIONS WILL CONTINUE OVERNIGHT. MAY SEE SOME
INSTANCES OF LIFR CONDITIONS LATE THIS EVENING AND EARLY OVERNIGHT
IN ADVANCE OF THE IMPROVING CONDITIONS TO THE SOUTH. CONFIDENCE IS
LOW HOW FAR NORTH THE BETTER CONDITIONS WILL REACH SO MAINTAINED A
SIMILAR STORY FROM THE PREVIOUS TAF.
/OUTLOOK FOR KMSP/
MON...MVFR/IFR CIGS CHC -SN. WINDS NW 20G30 KT.
TUE...VFR. WINDS W 5-10 KT.
WED...MVFR/IFR CHC -SN. WINDS NW 10KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...CLF
AVIATION...BORGHOFF
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
434 PM CST FRI NOV 21 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 422 PM CST FRI NOV 21 2014
THERE ARE A COUPLE FORECAST CHALLENGES OVER THE NEXT FEW DAYS. THE
FIRST: IS THE SLIGHT CHANCE FOR LIGHT FREEZING RAIN OR FREEZING
DRIZZLE IN FAR EASTERN MN AND WEST CENTRAL WI TONIGHT. THE SECOND:
IS THE MIXED P-TYPE AND WIND EVENT SUNDAY INTO MONDAY.
THERE HAS BEEN A STEADY STREAM OF HIGH CLOUDS TODAY...BUT THERE IS A
LOW STRATUS DECK STREAMING NORTH ACROSS SOUTHERN NE/IA THIS
AFTERNOON. THESE CLOUDS ARE TIED TO LOW LEVEL MOISTURE ADVECTION OUT
AHEAD OF AN ADVANCING SHORTWAVE CURRENTLY TRANSVERSE THE NORTHERN
PLAINS THIS AFTERNOON. WE THINK THERE WILL BE DEEPER SATURATION AND
BETTER OMEGA TO THE SOUTH AND WEST OF THE FORECAST AREA THIS EVENING
AND TONIGHT /BASICALLY INN AREAS CURRENTLY UNDER A FREEZING RAIN
ADVISORY/. THE SREF PROBABILITIES OF FREEZING RAIN/DRIZZLE ARE ON
THE ORDER OF 40-80% IN THESE AREAS. LOCALLY...WE`RE NOT CONFIDENT IN
MUCH ELSE BESIDES A HEALTHY STRATUS DECK AND PERHAPS SOME LIGHT FOG
AS THE STRATUS LOWERS. WE MAINTAINED LOW PROBS OF PRECIP IN EASTERN
PORTIONS OF THE FORECAST AREA WITH A MIX...AND IT ONLY TAKES A SMALL
AMOUNT OF FREEZING RAIN/DRIZZLE TO CAUSE PROBLEMS...BUT AS OF RIGHT
NOW THE BETTER LIFT AND DEEPER MOISTURE IS SOUTHEAST OF THE FORECAST
AREA. WE FOLLOWED THE LATEST REFLECTIVITY TRENDS OF THE HRRR...WHICH
MATCH UP REASONABLY WELL WITH THE 0.5KM CONDENSATION PRESSURE
DEFICITS OFF THE 20Z-22Z RAP.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 422 PM CST FRI NOV 21 2014
SPLIT FLOW WILL KEEP THE AREA LARGELY DRY INTO SUNDAY AFTERNOON
AS THE SOUTHERN STREAM LIFTS A TROUGH NORTHWARD FROM THE SOUTHERN
PLAINS INTO THE MID MISSISSIPPI VALLEY ON SUNDAY WHILE A TROUGH
DIGS INTO THE NORTHERN HIGH PLAINS ALONG THE NORTHERN STREAM.
THE NEXT MOIST SURGE MOVES IN WITH A STRONG WARM FRONT SATURDAY
EVENING AND OVERNIGHT. MODEL SIGNALS OF WARM FRONTAL
LIFT...850MB MOISTURE TRANSPORT CONVERGENCE...AND MOISTURE
ADVECTION INDICATE A FAIRLY HIGH LIKELIHOOD OF RAIN...PROBABLY
HIGHER THAN GUIDANCE INDICATES. AT THIS TIME...IT APPEARS THE
MODEL CONSENSUS AGREES THAT ONLY MINOR PRECIPITATION WOULD GO INTO
SNOW SUNDAY NIGHT AS COLDER AIR MOVES IN. THE FORECAST
SOUNDINGS...ESPECIALLY OFF THE NAM SHOW 35-40KTS AT THE TOP OF THE
MIXED LAYER WITH STEEP LOW LEVEL LAPSE RATES FOR 12-15 HOURS
SUNDAY NIGHT AND MONDAY. THE CONDITION OF THE SNOWPACK WILL BE IN
QUESTION IN THE EAST WITH THE SLIGHTLY WARMER TEMPS AND CHANCE FOR
RAIN...BUT WESTERN MN WILL REMAIN MUCH COOLER AND WE COULD ALSO
PICK UP A HIGH RATIO 0.5-2.0" IN SPOTS...SO THE THREAT FOR BLOWING
SNOW IS STILL A CONCERN IN WESTERN MN. WINTER HEADLINES ARE STILL
POSSIBLE FOR THIS PERIOD. ANOTHER COLD PERIOD BEGINS MONDAY AND
CURRENT THANKSGIVING HIGHS ARE IN THE TEENS AS A COLD AIR MASS
SETTLES IN AFTER A WEAK SYSTEM WEDNESDAY. THIS AIR MASS IN THE
NAEFS AND GEFS IS ABOUT 2 STANDARD DEVIATIONS BELOW NORMAL FOR
THURSDAY. THE OPERATIONAL RUNS ARE ALSO QUITE COLD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 547 AM CST FRI NOV 21 2014
INITIALLY QUIET CONDITIONS WITH VFR ACROSS THE BOARD.
HOWEVER...THINGS WILL CHANGE AS THE DAY PROGRESSES THANKS TO
STRONG WARM AIR ADVECTION ON THE BACKSIDE OF THE HIGH PRESSURE
RIDGE. MOST LOCATIONS ACROSS MN AND WESTERN WI ARE NOW OBSERVING
SOUTHERLY WINDS WHICH WILL BE THE DOMINANT DIRECTION THROUGH THE
TAF PERIOD. RAP AND NAM INDICATE EXPANDING SATURATION AT 925H THIS
AFTERNOON AND TONIGHT...SO EXPECTING TO SEE EXPANDING LOW STRATUS
FROM LATE THIS MORNING THROUGH SATURDAY MORNING. VIS LIMITATIONS
LOOK MOST PROMISING IN EASTERN MN AND WESTERN WI. CEILINGS SHOULD
CONTINUE TO LOWER TONIGHT...ESPECIALLY ACROSS THE EAST...WITH IFR
LIKELY AND LIFR POSSIBLE. SOME LIGHT PRECIP IS POSSIBLE IN WESTERN
WI...BUT LOW CONFIDENCE EXPLAINS SLIGHT CHANCE WORDING AND LACK OF
MENTION IN THE ACTUAL TAFS AT THIS TIME.
KMSP...LATEST GUIDANCE SUGGESTS THE MVFR CIGS ARRIVE AFTER DARK
AND CONDITIONS LOOK TO WORSEN OVERNIGHT AS RELATIVELY WARM AND
MOIST LOW LEVEL AIR FLOWS OVER THE PRESENT SNOW PACK. ANY PRECIP
TONIGHT LOOKS TO REMAIN TO THE SOUTHEAST...MAINLY IN WI.
/OUTLOOK FOR KMSP/
SAT...IFR POSSIBLE EARLY. WINDS SSW 10G20 KT.
SUN...MVFR/IFR WITH FZDZ/RA POSSIBLE. WINDS SE 10 KT.
MON...MVFR/IFR WITH -SN/BLSN POSSIBLE. WINDS NW 25G30 KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...CLF
LONG TERM...CLF
AVIATION...SPD
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
600 AM CST FRI NOV 21 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 403 AM CST FRI NOV 21 2014
A RIDGE OF HIGH PRESSURE HAS MOVED EAST ACROSS MINNESOTA OVERNIGHT AND
IS NOW IN WISCONSIN. OVERNIGHT TEMPERATURES HAVE BOTTOMED OUT AT
MANY LOCATIONS UNDER PARTLY CLOUDY SKIES AND LIGHT WINDS. SUB-
ZERO READINGS WERE FAIRLY COMMON ACROSS CENTRAL MN THROUGH WESTERN
WI. NOW THAT THE RIDGE AXIS IS TO THE EAST...SOUTHERLY WINDS HAVE
BEGUN TO INCREASE. WARM AIR ADVECTION IS BEGINNING TO OCCUR ACROSS
SOUTHWESTERN MN...ESPECIALLY THANKS TO DOWNSLOPING OFF THE BUFFALO
RIDGE.
THE WARM AIR ADVECTION IS THE STORY IN THE SHORT TERM...WITH THE
SOUTHERLY WINDS EXPECTED TO INCREASE THROUGH THE DAY AND MODERATING
TEMPERATURES EXPECTED. TODAY WILL BE QUITE A BIT WARMER THAN
YESTERDAY AS HIGHS SHOULD THE UPPER 20S ACROSS MOST OF THE
REGION...WITH LOWER 30S EXPECTED IN SW MN. ASSOCIATED WITH THE
SOUTHERLY WINDS AND WAA...CLOUDS WILL BUILD IN THROUGH THE DAY FROM
THE SOUTH. LOW POPS ACROSS WESTERN WI AND FAR EASTERN MN REMAIN IN
THE FORECAST TONIGHT...WITH THE BEST FORCING LIMITED TO IOWA AND
SOUTHERN WI. HOWEVER...THERE IS STILL SOME CONCERN OF A LIGHT WINTRY
MIX BEING SCATTERED ACROSS WESTERN WI AND SOUTHEASTERN MN TONIGHT.
NON DIURNAL TEMPERATURE TREND FOR TONIGHT...AS STRONG WARM AIR
ADVECTION CONTINUES. LATE EVENING TEMPS WILL COMMONLY BE IN THE
UPPER 20S...BUT WILL INCREASE TO THE MID 30S FOR MUCH OF SOUTHERN MN
BY EARLY SATURDAY MORNING.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 403 AM CST FRI NOV 21 2014
FEW CHANGES WERE MADE IN THE LONG TERM FORECAST PERIOD...WITH A
CONTINUED FOCUS ON THE POTENTIAL FOR A WINTER STORM IN THE SUNDAY-
MONDAY TIMEFRAME.
FOR SATURDAY...IT STILL LOOKS LIKE THE BULK OF THE PRECIPITATION
WILL BE TO THE EAST/SOUTH OF THE FORECAST AREA...WHERE BETTER
FORCING AND MOISTURE TRANSPORT ARE PROGGED. WHILE CLOUD COVER IS
EXPECTED TO BE FAIRLY EXTENSIVE...SOUTH-SOUTHWEST LLVL FLOW AND
WARM AIR ADVECTION SHOULD YIELD NEAR NORMAL HIGHS IN THE MID/UPPER
30S...WHICH WILL BREAK THE STREAK FOR CONSECUTIVE SUB-FREEZING
DAYS. COULD SEE SOME LINGERING MORNING DRIZZLE GENERALLY EAST OF
INTERSTATE 35...BUT OVERALL A DRY AND MILD DAY IS EXPECTED.
SATURDAY NIGHT AND SUNDAY BOTH 21.00Z GFS AND ECMWF MODELS
FORECAST THE DEVELOPMENT OF A HIGH AMPLITUDE TROUGH OVER THE CENTRAL
CONUS...AS SOUTHERN AND NORTHERN STREAM TROUGHS MARRY. WARM AIR
AND MOISTURE ADVECTION WILL CONTRIBUTE TO VERY MILD LOW TEMPS ON
SATURDAY NIGHT...WITH READINGS IN THE UPPER 20S TO MID 30S.
CONTINUED MILD WEATHER IS EXPECTED FOR SUNDAY...WITH HIGHS
SNEAKING INTO THE 40S FOR A GOOD PORTION OF EAST CENTRAL AND SOUTH
CENTRAL MINNESOTA AND WEST CENTRAL WISCONSIN. COULD SEE SOME AREAS
OF DRIZZLE DEVELOPING UNDER THE LOW CLOUD DECK...PRIMARILY
ALONG/EAST OF THE INTERSTATE 35 CORRIDOR. THE GOOD NEWS IS THAT
TEMPERATURES IN THESE AREAS SHOULD STAY WILL ABOVE FREEZING
SATURDAY NIGHT AND SUNDAY...SO THE THREAT FOR FREEZING DRIZZLE IS
LOW.
SUNDAY IS THE DAY THAT SOUTHERN AND NORTHERN STREAM LOW PRESSURE
CENTERS MERGE. THE DRY SLOT IN BETWEEN LOOKS TO BE CENTERED OVER
THE AREA...SO WITH THE EXCEPTION OF FAR EASTERN MN AND WEST
CENTRAL WI...WE MAY NOT SEE MUCH PRECIP UNTIL LATER SUNDAY AND
MONDAY AS THE DEFORMATION AXIS SHIFTS OVER THE AREA. BY MIDNIGHT
MONDAY MORNING...LIGHT SNOW SHOULD BE FALLING AND WINDS SHOULD BE
ON THE INCREASE OVER WEST CENTRAL MN. BY AFTERNOON...SNOW SHOULD
BE FALLING AREA-WIDE WITH BLOWING SNOW BECOMING A BIG
CONCERN...ESPECIALLY ALONG/SOUTH OF THE MN RIVER VALLEY. SNOW
AMOUNTS DON/T APPEAR TO REACH WARNING CRITERIA AT THIS POINT...BUT
ANTICIPATED WINDS COULD NECESSITATE A HEADLINE FOR BLIZZARD
CONDITIONS.
A PAIR OF WEAK CLIPPER SYSTEMS ARRIVE FROM THE NORTHWEST ON
WEDNESDAY AND FRIDAY...WHEN A FEW SNOW SHOWERS WILL BE POSSIBLE.
THE MAIN HIGHLIGHT FOR THE THANKSGIVING HOLIDAY WILL BE THE BLAST
OF COLD AIR...WITH HIGHS RANGING FROM THE UPPER SINGLE DIGITS TO
THE MID TEENS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 547 AM CST FRI NOV 21 2014
INITIALLY QUIET CONDITIONS WITH VFR ACROSS THE BOARD.
HOWEVER...THINGS WILL CHANGE AS THE DAY PROGRESSES THANKS TO
STRONG WARM AIR ADVECTION ON THE BACKSIDE OF THE HIGH PRESSURE
RIDGE. MOST LOCATIONS ACROSS MN AND WESTERN WI ARE NOW OBSERVING
SOUTHERLY WINDS WHICH WILL BE THE DOMINANT DIRECTION THROUGH THE
TAF PERIOD. RAP AND NAM INDICATE EXPANDING SATURATION AT 925H THIS
AFTERNOON AND TONIGHT...SO EXPECTING TO SEE EXPANDING LOW STRATUS
FROM LATE THIS MORNING THROUGH SATURDAY MORNING. VIS LIMITATIONS
LOOK MOST PROMISING IN EASTERN MN AND WESTERN WI. CEILINGS SHOULD
CONTINUE TO LOWER TONIGHT...ESPECIALLY ACROSS THE EAST...WITH IFR
LIKELY AND LIFR POSSIBLE. SOME LIGHT PRECIP IS POSSIBLE IN WESTERN
WI...BUT LOW CONFIDENCE EXPLAINS SLIGHT CHANCE WORDING AND LACK OF
MENTION IN THE ACTUAL TAFS AT THIS TIME.
KMSP...LATEST GUIDANCE SUGGESTS THE MVFR CIGS ARRIVE AFTER DARK
AND CONDITIONS LOOK TO WORSEN OVERNIGHT AS RELATIVELY WARM AND
MOIST LOW LEVEL AIR FLOWS OVER THE PRESENT SNOW PACK. ANY PRECIP
TONIGHT LOOKS TO REMAIN TO THE SOUTHEAST...MAINLY IN WI.
/OUTLOOK FOR KMSP/
SAT...IFR POSSIBLE EARLY. WINDS SSW 10G20 KT.
SUN...MVFR/IFR WITH FZDZ/RA POSSIBLE. WINDS SE 10 KT.
MON...MVFR/IFR WITH -SN/BLSN POSSIBLE. WINDS NW 25G30 KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...SPD
LONG TERM...LS
AVIATION...SPD
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
646 PM CST Sat Nov 22 2014
.UPDATE:
Issued at 639 PM CST Sat Nov 22 2014
Have made some refinements to the POPS tonight into early Sunday
morning. The main axis of rain/showers this evening will reside
across southeast MO across southwest and south central IL within
the warm moist conveyor belt and ahead of a subtle impulse in the
southwest flow aloft. Further north and northwest across northeast
and central MO the chance of precipitation appears rather low
given the lack of any forcing, and if any occurs it will likely be
isolated or in the form of sprinkles or drizzle. The precipitation
threat will ramp up overnight however in central and northeast MO,
especially after 08-09z with large scale ascent associated with a
shortwave currently over TX moves northeastward into the area and
low level flow backs refocusing the lift westward. Lift and
showers/rain associated with this wave will overspread the entire
area early-mid Sunday morning.
Glass
&&
.SHORT TERM: (Through Late Tonight)
Issued at 347 PM CST Sat Nov 22 2014
Scattered showers are already moving across the southern half the
CWA this afternoon in an area of modest 925-850mb moisture
convergence ahead of the trough currently over the southern High
Plains. Expect rain to become more widespread late this afternoon
into the early evening hours over the southern two thirds of the CWA
as the showers currently over southwest Missouri continue to move
northeast into the area. This is being forced by an area of
stronger low level moisture convergence that the HRRR shows moving
across the area between 22-03Z. While there will still continue to
be scattered showers elsewhere behind this area through late
evening, it still appears that better chances for more widespread
rain will move in from the west after midnight. By that time, large
scale ascent and moisture convergence will be increasing ahead of the
aforementioned southern Plains trough that will be ejecting
northeastward ahead of longwave trough. With clouds and warm air
advection tonight, stayed with lows that were close to going
temperatures and MOS guidance.
Britt
.LONG TERM: (Sunday through Next Saturday)
Issued at 347 PM CST Sat Nov 22 2014
Rain and a few thunderstorms are expected on Sunday as a southern
stream, negatively tilted shortwave moves from eastern TX
northeastward into the TN and OH Valley regions, while a northern
stream upper level trough/low moves slowly east southeastward
through the northern Plains. The models were depicting upper level
divergence over our area between a strong upper level jet streak
across the southern Plains and a weaker upper level jet streak over
the Great Lakes region. The models have some discrepencies as to
the exact track of the deepening surface low, but at this time it
appears that it will move northeastward through or just north of the
STL area around 00z Monday. There will be ample instability for at
least isolated thunderstorms on Sunday into Sunday evening,
especially across southeast MO and southwest IL. Strong low level
cold air advection can be expected Sunday night after the passage of
the low and trailing cold front. The threat for precipitation will
continue Sunday night as shortwaves rotate through our area south of
the main upper level low/trough over the northern Plains. As the
colder air filters southeastward into the region the rain may change
over to light snow before ending late Sunday night/early Monday
morning across portions of northeast and central MO as well as west
central IL. Most of the precipitation will shift east of our
forecast area by Monday, although there may be some lingering light
snow or flurries mainly across west central IL. Much colder
temperatures can be expected for Monday, with nearly steady
temperatures, mainly in the middle 30s to lower 40s as the NAM and
ECMWF models drop the -8 degree C 850 mb isotherm southward to STL.
The GFS model is even colder and quicker bringing the colder air
southeastward into our forecast area. An unseasonably cold period
is expected through Tuesday night as a large amplitude positively
tilted upper level trough moves eastward through the central US.
The GFS and ECMWF models are still hinting at the possibility of a
northwest flow shortwave and associated weak surface low to bring a
quick shot of rain/snow to our area late Tuesday night and
Wednesday. The models, particularly the GFS are not as cold for
Thanksgiving Day with the coldest air remaining just north of our
forecast area, although a strong surface ridge is still forecast to
build southeastward into the region from the northern Plains on
Thanksgiving.
GKS
&&
.AVIATION: (For the 00z TAFs through 00z Sunday Evening)
Issued at 522 PM CST Sat Nov 22 2014
Specifics for KCOU, KUIN: Conditions may initially bounce between
MVFR and VFR early in the TAF period, but any improvement to VFR should
be temporary based on a broader cig/vis analysis and moisture
forecasts. An approaching low pressure system will bring
widespread rain to KCOU and KUIN on Sunday, and conditions are
expected to fall to IFR. Precipitation should end with the passage
of a cold front beyond the end of the 24-hr TAF period.
Specifics for KSTL, KSUS, KCPS: An area of rain showers was moving
northeastwards across the St. Louis metro area terminals at TAF
issuance. Ceilings will probably bounce between VFR and MVFR
before falling solidly into MVFR with the arrival of the rain.
Much more widespread rain is expected on Sunday ahead of a low
pressure system, and conditions will likely fall to IFR during
this time. Rain should end on Sunday night with the arrival of a
cold front.
Kanofsky
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
538 PM CST Sat Nov 22 2014
.SHORT TERM: (Through Late Tonight)
Issued at 347 PM CST Sat Nov 22 2014
Scattered showers are already moving across the southern half the
CWA this afternoon in an area of modest 925-850mb moisture
convergence ahead of the trough currently over the southern High
Plains. Expect rain to become more widespread late this afternoon
into the early evening hours over the southern two thirds of the CWA
as the showers currently over southwest Missouri continue to move
northeast into the area. This is being forced by an area of
stronger low level moisture convergence that the HRRR shows moving
across the area between 22-03Z. While there will still continue to
be scattered showers elsewhere behind this area through late
evening, it still appears that better chances for more widespread
rain will move in from the west after midnight. By that time, large
scale ascent and moisture convergence will be increasing ahead of the
aforementioned southern Plains trough that will be ejecting
northeastward ahead of longwave trough. With clouds and warm air
advection tonight, stayed with lows that were close to going
temperatures and MOS guidance.
Britt
.LONG TERM: (Sunday through Next Saturday)
Issued at 347 PM CST Sat Nov 22 2014
Rain and a few thunderstorms are expected on Sunday as a southern
stream, negatively tilted shortwave moves from eastern TX
northeastward into the TN and OH Valley regions, while a northern
stream upper level trough/low moves slowly east southeastward
through the northern Plains. The models were depicting upper level
divergence over our area between a strong upper level jet streak
across the southern Plains and a weaker upper level jet streak over
the Great Lakes region. The models have some discrepencies as to
the exact track of the deepening surface low, but at this time it
appears that it will move northeastward through or just north of the
STL area around 00z Monday. There will be ample instability for at
least isolated thunderstorms on Sunday into Sunday evening,
especially across southeast MO and southwest IL. Strong low level
cold air advection can be expected Sunday night after the passage of
the low and trailing cold front. The threat for precipitation will
continue Sunday night as shortwaves rotate through our area south of
the main upper level low/trough over the northern Plains. As the
colder air filters southeastward into the region the rain may change
over to light snow before ending late Sunday night/early Monday
morning across portions of northeast and central MO as well as west
central IL. Most of the precipitation will shift east of our
forecast area by Monday, although there may be some lingering light
snow or flurries mainly across west central IL. Much colder
temperatures can be expected for Monday, with nearly steady
temperatures, mainly in the middle 30s to lower 40s as the NAM and
ECMWF models drop the -8 degree C 850 mb isotherm southward to STL.
The GFS model is even colder and quicker bringing the colder air
southeastward into our forecast area. An unseasonably cold period
is expected through Tuesday night as a large amplitude positively
tilted upper level trough moves eastward through the central US.
The GFS and ECMWF models are still hinting at the possibility of a
northwest flow shortwave and associated weak surface low to bring a
quick shot of rain/snow to our area late Tuesday night and
Wednesday. The models, particularly the GFS are not as cold for
Thanksgiving Day with the coldest air remaining just north of our
forecast area, although a strong surface ridge is still forecast to
build southeastward into the region from the northern Plains on
Thanksgiving.
GKS
&&
.AVIATION: (For the 00z TAFs through 00z Sunday Evening)
Issued at 522 PM CST Sat Nov 22 2014
Specifics for KCOU, KUIN: Conditions may initially bounce between
MVFR and VFR early in the TAF period, but any improvement to VFR should
be temporary based on a broader cig/vis analysis and moisture
forecasts. An approaching low pressure system will bring
widespread rain to KCOU and KUIN on Sunday, and conditions are
expected to fall to IFR. Precipitation should end with the passage
of a cold front beyond the end of the 24-hr TAF period.
Specifics for KSTL, KSUS, KCPS: An area of rain showers was moving
northeastwards across the St. Louis metro area terminals at TAF
issuance. Ceilings will probably bounce between VFR and MVFR
before falling solidly into MVFR with the arrival of the rain.
Much more widespread rain is expected on Sunday ahead of a low
pressure system, and conditions will likely fall to IFR during
this time. Rain should end on Sunday night with the arrival of a
cold front.
Kanofsky
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
350 PM CST Fri Nov 21 2014
.SHORT TERM: (Through Late Tonight)
Issued at 349 PM CST Fri Nov 21 2014
Will continue the chance of light rain as low level moisture
convergence and large scale ascent increases ahead of shortwave
trough currently moving towards us across the central Plains. There
are two small areas of rain that have developed ahead of this
system...one over west central Missouri which will move into central
and northeast Missouri later this afternoon and a second over
northern Arkansas which will move into southeast Missouri. Rain
chances will increase areawide this evening as aforementioned trough
moves across Missouri and Illinois. Chances will continue through
the night as a 50kt low level jet sets up over the region which will
provide more low level moisture convergence. At this time it still
appears that precipitation from this event will be mostly liquid as
dewpoints are steadily rising as rain moves into the area. Both the
HRRR and RUC are showing that the surface wet-bulb temperatures will
be at or above freezing during the onset of precipitation through
early this evening with temperatures continuing to rise through the
late evening hours.
Britt
.LONG TERM: (Saturday through Next Friday)
Issued at 349 PM CST Fri Nov 21 2014
At least scattered light showers can be expected Saturday and
Saturday night due to low-mid level warm air advection and as a
southwesterly low level jet continues to bring low level moisture
into the area. The best chance of rain along with the highest
rainfall amounts should occur on Sunday as a southern stream
negatively tilted shortwave moves through the southern Plains and
into the TN Valley region, while an upper level low moves
southeastward into the northern Plains. There will be upper level
divergence over our area between an upper level jet streak across
the southern Plains and another upper level jet streak across the
Great Lakes region. A surface low will develop and deepen as it
moves northeastward through the St Louis area around 00z Monday.
There should be at least isolated thunderstorms across portion sof
central and southeast MO and southwest IL. Temperatures will be
much warmer this weekend and above normal for a change. Much of the
precipitation should shift east of our forecast area Sunday night as
colder and drier air filters southeastward into the region behind
the surface low and trailing cold front. There may be some
lingering precipitation Sunday night into Monday morning as
shortwaves move through the area south of the upper level low which
will progress slowly eastward into the Great Lakes region. The rain
may change over to some light snow across northeast MO and west
central IL late Sunday night and Monday as colder air continues to
advect into the region. Temperatures will return to below normal
values beginning Monday with both the GFS and ECMWF models dropping
the -8 degree C 850 mb isotherm down to STL by 18z Monday. Below
normal temperatures are expected from Monday through Thanksgiving
with little if any precipitation as a deep upper level trough moves
slowly eastward through the central US. The ECMWF model does drop a
northwest flow, clipper type shortwave and associated weak surface
low southeastward through our area which could bring the potential
for a brief period of snow on Wednesday, but the GFS is much weaker
with this feature and only has very light QPF. A strong surface
ridge will build southeastward into MO for Wednesday night and
Thanksgiving Day with unseasonably cold temperatures expected.
GKS
&&
.AVIATION: (For the 18z TAFs through 18z Saturday Afternoon)
Issued at 1230 PM CST Fri Nov 21 2014
Low based VFR or high MVFR will continue to move northeast across
the area this afternoon. Rain will begin to move into the area
later this afternoon into the evening hours, though the coverage
is not expected to great enough to warrant more than VCSH at this
point. Later this evening and overnight, a low level jet is
expected to develop over the region which will bring LLWS
conditions at all of the airports. These conditions will last
until around 14Z Saturday morning. Then low based VFR or high MVFR
are expected during Saturday with a low chance of rain.
Specifics for KSTL: Expect mainly low VFR conditions through the
day today until this evening when MVFR ceilings move into the area
with a chance of rain. Expect LLWS conditions overnight with
persistent MVFR ceilings before ceilings rise to VFR during the
day with a continued low chance of rain.
Britt
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS GLASGOW MT
806 PM MST SAT NOV 22 2014
.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH MONDAY...
EVENING UPDATE...
CHANGE FOR THIS EVENING WAS FOCUSED ON RAISING POPS ALONG THE LEE
OF THE LITTLE ROCKIES INTO THE SNOW BELTS OF GARFIELD COUNTY.
NAMDNG5... CMC REGIONAL... HRRR... AND RAP ARE ALL POINTING TOWARD
THIS AREA RECEIVING SOMETHING WITHIN THE NEXT 6 HOURS. LOOKING
UPSTREAM ON RADAR IN FERGUS AND BLAINE COUNTY DOES SHOW EVIDENCE
OF DEVELOPING SHOWERS. GAH
PREVIOUS SHORT TERM DISCUSSION...
THIS AFTERNOON...A STRONG SURFACE LOW PRESSURE SYSTEM HAS DRAWN A
COLD FRONT THROUGH NORTHEAST MONTANA. WEST WINDS BEHIND THE SYSTEM
HAVE BEEN QUITE STRONG...TOPPING 30 MPH IN PLACES NEAR THE WESTERN
EDGE OF THE CWA. 750MB WINDS ARE QUITE STRONG AND SOME CLEARING
SKIES OUT WEST HAVE ALLOWED SOMEWHAT BETTER MIXING IN THAT AREA.
WINDS SHOULD EASE A LITTLE BIT AFTER DARK...HOWEVER...STRONG
SURFACE PRESSURE GRADIENT WILL KEEP WINDS IN THE MODERATE TO
STRONG LEVEL TONIGHT AND THROUGH TOMORROW AFTERNOON. WINDS WILL
VEER MORE NORTHERLY TONIGHT WITH STRONGER COLD ADVECTION.
INITIAL ROUND OF LIGHT RAIN SHOWERS HAS MOVED OFF EAST OF THE
AREA WITH SNOW SHOWERS EXPECTED THIS EVENING COMING DOWN FROM THE
NORTH ALONG THE CANADIAN BORDER. CLEARING BEHIND THIS INITIAL WAVE
IS RELATED TO Q-VECTOR DIVERGENCE AND DRY SLOT BEHIND POSITIVE
VORTICITY ADVECTION AREA. SNOW SHOWERS ARE IN WRAP AROUND AREA
AND OCCUR WITH COLD AIR ADVECTION TONIGHT. SNOW AMOUNTS ARE NOT
EXPECTED TO BE GREAT...WITH ANYWHERE FROM A HALF INCH TO 2 INCHES
EXPECTED THROUGH SUNDAY. HIGH RESOLUTION MODELS HAVE LESS SNOW
THAN THE SYNOPTIC MODELS. THE HRRR HAS ALMOST NONE. THE NAM...ON
THE OTHER HAND...HAS SOME LOCALIZED AREAS OF MODERATE SNOW. WITH
STRONG WINDS...AN INCH OF SNOW COULD BLOW AROUND ENOUGH TO CAUSE
TRAVEL DIFFICULTIES...SO ISSUED AN ADVISORY FOR BLOWING SNOW.
SYSTEM PROGRESSES FAIRLY QUICKLY EASTWARD AND SHOWERS LOOK TO END
LATE SUNDAY AFTERNOON. MARTIN
.LONG TERM...MONDAY NIGHT THROUGH SATURDAY...
THE EXTENDED PERIOD WILL SEE A LONG-WAVE TROUGHS OVER THE EAST HALF
OF THE NATION AND CANADA. THESE TROUGHS WILL BE ANCHORED BY THE
PERSISTENT ARCTIC LOW OVER THE NUNAVUT TERRITORY OF CANADA. THIS
LOW WILL SEE SHORT-WAVE TROUGH ROTATE AROUND THE MAIN LOW CENTER.
THESE SHORT-WAVES WILL LARGELY DETERMINE TEMPERATURES FOR NORTHEAST
MONTANA THROUGH THE EXTENDED PERIOD. OFF TO THE WEST THERE WILL BE
AN EQUALLY PERSISTENT RIDGE THAT WILL LARGELY MAINTAIN NORTHWEST
FLOW ALOFT FOR OUR REGION.
TUESDAY EVENING NORTHEAST MONTANA WILL BE ON THE COLD SIDE OF THE
BOUNDARY BETWEEN THE WESTERN AND EASTERN AIR-MASSES. THERE WILL BE
MOVEMENT OF A SHORT-WAVE EXTENDING FROM THE CANADIAN LOW. IN
COINCIDENCE WILL BE A DISTURBANCE RIDGING OVER THE TOP OF THE RIDGE.
THE ACTION BETWEEN THESE TWO DISTURBANCES WILL AT FIRST BE A
SIGNIFICANT AMOUNT OF MOISTURE OVERRIDING THE LENGTH OF THE
BOUNDARY. THIS WILL PRODUCE RAIN OF THE WARM SIDE AND WINTRY MIX
ON THE EAST SIDE. THE MAIN FORECAST CHALLENGE OF THE EXTENDED
PERIOD WILL BE THE LOCATION OF THE BOUNDARY IN RELATION TO
NORTHEAST MONTANA. A DIFFERENCE OF JUST A FEW HUNDRED MILES WILL
MAKE A LARGE DIFFERENCE IN TEMPERATURES.
TUESDAY...BOTH THE GFS AND EC PLACE THE BOUNDARY JUST TO OUR WEST
WHICH WILL LEAD TO SLIGHTLY COOLER THAN NORMAL TEMPERATURES. THE
OVERRUNNING MOISTURE ALSO APPEARS TO BE RUNNING PRECIPITATION TO
OUR WEST.
TUESDAY NIGHT AND WEDNESDAY...THE BOUNDARY DRIFTS EAST AND
TIGHTENS PRECIPITATION SPREADS ACROSS NEMONT. THE PRECIPITATION
TYPE WILL BE DIFFICULT TO DETERMINE THIS FAR OUT...BUT IT WILL
LIKELY BE RAIN IN THE WEST AND SNOW IN THE NORTHEAST...WITH A
WINTRY MIX IN THE MIDDLE.
KEEPING IN MIND THAT THE MODELS HAVE BEEN GOING IN AND OUT OF
AGREEMENT...TEMPERATURES AND WX HAVE SOME UNCERTAINTY. BUT FOR
NOW SNOW AMOUNTS SUGGEST WINTER HEADLINES FOR THE MIDDLE OF NEXT
WEEK... WITH SNOW AMOUNTS RANGING FROM 1 TO 4 INCHES BY
THANKSGIVING MORNING.
THANKSGIVING DAY...BOTH MODELS SUGGEST ANOTHER COLD WAVE ROUNDING
THE ARCTIC LOW THAT WILL BACKDOOR ANOTHER COLD FRONT INTO NEMONT.
THIS WILL TURN THE PRECIPITATION TO ALL SNOW...MAINLY IN THE
SOUTHWEST PORTION OF THE CWA AND BRING ABOUT COLDER TEMPERATURES.
FRIDAY AND SATURDAY...THE BOUNDARY CONTINUES TO FLUCTUATE BUT WILL
LIKELY KEEP THE MAJORITY OF THE CWA IN THE COLD SECTION. THERE
WILL ALSO BE LESSOR AMOUNTS OF OVERRUNNING MOISTURE FOR ADDITIONAL
LIGHT SNOW.
SCT
PREVIOUS DISCUSSION...
MONDAY NIGHT THROUGH FRIDAY...PERSISTENT UPPER LOW OVER HUDSON
BAY AREA DURING PERIOD. UPPER LEVEL RIDGE OVER PACIFIC NW MONDAY
SLOWLY MOVES INTO NORTHERN ROCKIES AND FLATTENS OUT BY SATURDAY.
RIDGE AND ACCOMPANYING WEST WINDS PROVIDE SEASONABLY PLEASANT
TEMPERATURES TUESDAY.
WEDNESDAY SHORT WAVES SWEEPING DOWN THROUGH NORTHWEST FLOW WILL
BRING CHANCE OF RAIN AND SNOW TO NORTHEAST MONTANA. GFS40 AND
ECMWF/GFS13 BEGIN TO DIVERGE LATER WEDNESDAY HOWEVER. GFS40 DIGS
TROUGH SOUTHWARD ACROSS STATE WHILE ECMWF AND GFS13 TAKE SHORT WAVE
FURTHER EAST. WILL LEAN TOWARD MORE CONSISTENT AND DRIER ECMWF/GFS13
SOLUTIONS. BY THANKSGIVING DAY A RIDGE DEVELOPS OVER MONTANA WITH
A NORTHWEST FLOW ALOFT. EXPECT ONLY SLIGHT CHANCE RAIN AND SNOW
THROUGH REMAINDER OF PERIOD BENEATH WEAK RIDGE. TEMPERATURES WILL BE
SOMEWHAT COOLER AFTER TUESDAY AND WELL BELOW SEASONAL NORMALS.
EXPECT WINDS TO BE RELATIVELY LIGHT THROUGH THE PERIOD. BRITTON
&&
.AVIATION...
FLIGHT CATEGORY: VFR TO IFR
SYNOPSIS: A FAST MOVING CLIPPER WILL SWEEP ACROSS THE REGION
TONIGHT AND SUNDAY MORNING. BOTH THE UPPER AND LOWER LEVEL LOWS
CLOSE OFF AND STACK UP OVER SOUTHERN SASKATCHEWAN. THE RESULTING
COMPACT CYCLONE WILL BECOME RATHER EFFICIENT IN PRODUCING VERY
STRONG WINDS TONIGHT AND SUNDAY MORNING OVER NORTHEAST MONTANA.
WRAP-AROUND SNOW COULD INCREASE THE CHANCES FOR HEAVIER... MEASURABLE
SNOW ON SUNDAY MORNING...TAPERING OFF IN THE AFTERNOON.
AREA WINDS: NORTHWEST WINDS COULD RANGE FROM 20KT TO 30KT WITH
GUSTS TO 45KT. WIND WILL TAPER OFF TO AROUND 15KT SUNDAY
AFTERNOON.
VSBY: WITH LIGHT SNOW EXPECTED... AND EXISTING SNOW ON THE GROUND...
BLOWING SNOW COULD BECOME AN ANOTHER ISSUE AFFECTING VISIBILITY...
ALONG WITH SNOW DRIFTS ACROSS RUNWAYS. ANY TERMINAL WITH FALLING
SNOW COULD TEMPORARILY SEE MVFR/IFR VISIBILITY.
CEILINGS: EXPECT LOW-LEVEL OVERCAST WITH MVFR/IFR CEILINGS.
GAH
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY UNTIL 5 PM MST SUNDAY FOR CENTRAL AND
SOUTHEAST PHILLIPS...CENTRAL AND SOUTHERN VALLEY...GARFIELD...
MCCONE...PETROLEUM.
WINTER WEATHER ADVISORY UNTIL 2 PM MST SUNDAY FOR CENTRAL AND
SOUTHEAST PHILLIPS...CENTRAL AND SOUTHERN VALLEY...DANIELS...
DAWSON...EASTERN ROOSEVELT...GARFIELD...MCCONE...NORTHERN
PHILLIPS...NORTHERN VALLEY...PRAIRIE...RICHLAND...SHERIDAN...
SOUTHWEST PHILLIPS...WESTERN ROOSEVELT...WIBAUX.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1214 PM CST FRI NOV 21 2014
.UPDATE...
ISSUED AT 1145 AM CST FRI NOV 21 2014
UPDATED THE FORECAST FOR HIGH TEMPERATURES TODAY. THE MORNING 12Z
SOUNDING FROM KLBF SHOWED AN IMPRESSIVE INVERSION WITH
TEMPERATURES INCREASING FROM -6C AT THE SURFACE TO 6C AT 875MB.
FROM 875MB THROUGH 800MB TEMPERATURES WERE FAIRLY ISOTHERMAL. THE
QUESTION HAD BEEN HOW DEEP MIXING WOULD OCCUR TODAY AND FROM
OBSERVATIONS THIS MORNING SOUTHWEST WINDS ACROSS THE WESTERN TWO-
THIRDS OF THE FORECAST AREA HAVE HELPED THINGS ALONG WITH AS
TEMPERATURES HAVE WARMED QUICKER THAN HAD ANTICIPATED. THIS WOULD
INDICATE MIXING WILL BE A BIT DEEPER...PERHAPS TO 850-800MB FOR
MUCH OF THE AREA /MAYBE A LITTLE LOWER OVER NORTH CENTRAL NEBRASKA
WHERE SNOW COVER WILL HAMPER THE WARMING SOME. DUE TO THE TREND
THUS FAR TODAY HAVE WARMED TEMPERATURES UP TO 5 DEGREES IN SOME
AREAS. RAP AND HRRR MODELS ARE SHOWING POTENTIAL FOR 60 OVER FAR
SOUTHWEST NEBRASKA. HAVEN/T GONE THAT WARM...BUT UPPER 50S IS NOW
IN THE CURRENT FORECAST.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 338 AM CST FRI NOV 21 2014
ALL MODELS IN GOOD AGREEMENT IN THE NEAR TERM AND POINTING TOWARDS
A WARM UP TODAY. SOUTHERLY FLOW AND INCREASING MID CLOUDS WILL
HELP TO KEEP TEMPERATURES UP EARLY THIS MORNING WITH A WARM START
TO THE DAY. WARM FRONT WILL CONTINUE TO MOVE TO THE NORTHEAST
ACROSS THE NORTHERN PLAINS TODAY. STILL ABOUT AN INCH OF SNOW
ALONG AND NORTH OF HIGHWAY 20 TO THE SOUTH DAKOTA BORDER.
TEMPERATURE GRIDS WILL CONTINUE TO REFLECT THIS SNOW FIELD TODAY
AND TONIGHT. 850MB TEMPERATURES CLIMB TOWARDS 12C BY 22/18Z.
BELIEVE TEMPERATURE FORECAST MAY BE UNDER DONE AGAIN TODAY BUT
HAVE PUSHED THE ENVELOPE. HIGH TEMPERATURES YESTERDAY OUT DID
GUIDANCE BY A 1 CATEGORY AND BELIEVE THIS IS POSSIBLE AGAIN TODAY
WITH MODEL BIAS BASED ON SNOW COVER. PARTLY TO MOSTLY CLOUDY TODAY
WITH CLOUDS DECREASING THIS EVENING AND ANOTHER MILD EVENING WITH
GOOD WARM AIR ADVECTION. LOW TEMPERATURES IN THE 20S. DRY.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 338 AM CST FRI NOV 21 2014
12Z SATURDAY AND BEYOND. A LEE SIDE SFC TROUGH WILL DEEPEN THROUGH
THE DAY ON SATURDAY...ALLOWING FOR A SOUTHWEST TRAJECTORY OF THE
LOWER TROPOSPHERIC WIND ACROSS THE ENTIRE CWA. H85 TEMPERATURES BY
00Z SUNDAY WILL BE IN THE 9 TO 11 C RANGE...WHICH WOULD PROMOTE
HIGHS GENERALLY IN THE 50S AND 60S FOR MOST LOCATIONS. GUIDANCE AS
OF LATE HAS SHOWN A COOL BIAS WITH THE NAM IMPACTED STILL BY
PERCEIVED SNOWPACK...THUS THE HIGH TEMPERATURE FORECAST WILL TRENDED
TOWARD THE WARMER MAV...AND THEN MANUALLY ADJUSTED A FEW DEGREES
WARMER FROM THERE. THE FORECAST CALLS FOR LOWER 60S FOR ALL
LOCATIONS ALONG AND SOUTH OF INTERSTATE 80 NOW. A COLD FRONT
HOWEVER WILL COOL TEMPERATURES FOR SUNDAY SOME 10-15 DEGREES. LIGHT
PRECIPITATION...OR POSSIBLY FLURRIES/SPRINKLES WILL BE POSSIBLE
EARLY SUNDAY WITH THE PASSAGE OF THE UPPER TROUGH...HOWEVER BOTH THE
NAM AND THE GFS INDICATE A LESS THAN IDEAL MOISTURE PROFILE. FOR
THIS WOULD LIKE TO SEE ANOTHER SET OF MODEL RUNS BEFORE ADDING A QPF
MENTION. NOTE HOWEVER A LIGHT SNOW MENTION WAS CONTINUED EARLY
SUNDAY ACROSS NORTHWEST NEBRASKA AS THE MODELS CONTINUE TO SHOW
BETTER MOISTURE IN PLACE.
SNOW CHANCES REMAIN ACROSS NORTHERN NEBRASKA SUNDAY NIGHT INTO
MONDAY AS A CLOSED UPPER LEVEL LOW MOVES FROM THE EASTERN DAKOTAS
TOWARDS THE GREAT LAKES REGION. AT THIS POINT MODEL AGREEMENT IS
LACKING...THUS WILL MAINTAIN ONLY A SLIGHT CHANCE MENTION. NORTHWEST
FLOW ALOFT BEHIND THE PASSING UPPER LOW WILL KEEP CONDITIONS
SEASONAL FOR EARLY NEXT WEEK. HIGHS WILL BE COOL ON MONDAY WITH
UPPER 20S ANTICIPATED ACROSS OUR NORTHERN ZONES...LOWER 40S FOR THE
SOUTH. LOWS IN THE TEENS AND 20S SHOULD PREVAIL BOTH MONDAY AND
TUESDAY MORNING. TEMPERATURES WARM SLIGHTLY FOR TUESDAY AS A LEE
TROUGH DEEPENS OFF THE HIGH PLAINS ALLOWING FOR A RETURN OF LOWER
TROPOSPHERIC SOUTHWEST FLOW. MOST LOCATIONS SHOULD SEE HIGH IN THE
UPPER 30S TO LOW 40S...ACROSS SOUTHWEST NEBRASKA AND THE FAR EASTERN
PANHANDLE...MID 40S WILL BE POSSIBLE.
LATE TUESDAY AND BEYOND THE MODELS CONTINUE TO STRUGGLE WITH
CONSISTENCY AND GENERAL AGREEMENT. BOTH THE GFS AND ECMWF DEPICT
ANOTHER SLUG OF ARCTIC AIR ARRIVING ATOP THE CENTRAL PLAINS SOMETIME
MID-WEEK. IN ADDITION...BOTH MODELS GENERATE LIGHT QPF AT TIMES
ACROSS PORTIONS OF THE FORECAST AREA WITH FAVORABLE UPPER JET
DYNAMICS AND THE PASSAGE OF AN UPPER TROUGH/S/. BUT THE ECMWF HAS
FLOPPED FROM 24 HOURS AGO...NOW FAVORING A WARMER SOLUTION FOR
THURSDAY AND BEYOND...WHEREAS THE GFS IS DEPICTING SIGNIFICANTLY
COOLER TEMPERATURES /THIS IS A FLOP AS WELL/. FOR COMPARISON BY 00Z
FRIDAY...THE GFS AND ECMWF ARE UPWARDS TO 20C DIFFERENT AT H85 OVER
WESTERN PORTIONS OF THE FORECAST AREA AS THE ECMWF IS QUICK TO FORCE
THE COLD AIR EAST /BIG REVERSAL FROM 24 HOURS AGO/. THE GFS
SUGGESTS BELOW AVERAGE TEMPERATURES CONTINUING THROUGH THE REMAINDER
OF THE WEEK AND INTO THE WEEKEND...AGAIN AND CONTRADICTION TO 24
HOURS AGO BUT IS SLOWER WITH THE ARRIVAL OF THE ARCTIC INTRUSION.
GIVEN THE LONG RANGE MODELS ARE SHOWING LITTLE IF ANY
AGREEMENT...FELT THE BEST COURSE OF ACTION WAS TO EMPLOY THE BLENDED
FORECAST APPROACH /SUPERBLEND/. THE SUPERBLEND /POSSIBLY
COMPROMISED FROM THE PREVIOUS COLDER ECMWF FORECAST/ SEEMS TO FAVOR
A SLIGHTLY COOLER SOLUTION. THIS SUGGESTS HIGHS ON THURSDAY IN THE
20S FOR MUCH OF THE FORECAST AREA WITH THE POSSIBILITY OF LIGHT
SNOW. OBVIOUSLY IMPACTS TO HOLIDAY TRAVEL COULD BE GREAT GIVEN THE
TIMING OF THE POTENTIAL SNOW/ARCTIC INTRUSION...IT MUST BE STATED
THAT FORECAST CONFIDENCE IS LOW BEYOND TUESDAY EVENING...ANTICIPATE
FORECAST CHANGES AS THE MODELS EVENTUAL CONVERGE ON A SOLUTION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1214 PM CST FRI NOV 21 2014
LOOKING FOR VFR CONDITIONS THROUGH WESTERN AND NORTH CENTRAL
NEBRASKA TONIGHT AND SATURDAY MORNING. WILL BE MONITORING A LARGE
AREA OF STRATUS AND FOG CURRENTLY OVER PARTS OF KANSAS AND
OKLAHOMA AS IT IS EXPECTED TO LIFT NORTH AND EAST OVERNIGHT.
BELIEVE THE TRAJECTORY OF THE LOW LEVEL FLOW WILL KEEP IT EAST OF
THE LOCAL AREA SO HAVE NOT INCLUDED ANY RESTRICTIONS TO VISIBILITY
OR LOWERED CEILINGS IN THIS FORECAST. WINDS WILL STAY OUT OF THE
SOUTHWEST THROUGH SATURDAY AFTERNOON AND AFTER DIMINISHING TONIGHT
SHOULD INCREASE AGAIN TO AROUND 10-15KTS SATURDAY.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BROOKS
SHORT TERM...POWER
LONG TERM...JACOBS
AVIATION...BROOKS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1146 AM CST FRI NOV 21 2014
.UPDATE...
ISSUED AT 1145 AM CST FRI NOV 21 2014
UPDATED THE FORECAST FOR HIGH TEMPERATURES TODAY. THE MORNING 12Z
SOUNDING FROM KLBF SHOWED AN IMPRESSIVE INVERSION WITH
TEMPERATURES INCREASING FROM -6C AT THE SURFACE TO 6C AT 875MB.
FROM 875MB THROUGH 800MB TEMPERATURES WERE FAIRLY ISOTHERMAL. THE
QUESTION HAD BEEN HOW DEEP MIXING WOULD OCCUR TODAY AND FROM
OBSERVATIONS THIS MORNING SOUTHWEST WINDS ACROSS THE WESTERN TWO-
THIRDS OF THE FORECAST AREA HAVE HELPED THINGS ALONG WITH AS
TEMPERATURES HAVE WARMED QUICKER THAN HAD ANTICIPATED. THIS WOULD
INDICATE MIXING WILL BE A BIT DEEPER...PERHAPS TO 850-800MB FOR
MUCH OF THE AREA /MAYBE A LITTLE LOWER OVER NORTH CENTRAL NEBRASKA
WHERE SNOW COVER WILL HAMPER THE WARMING SOME. DUE TO THE TREND
THUS FAR TODAY HAVE WARMED TEMPERATURES UP TO 5 DEGREES IN SOME
AREAS. RAP AND HRRR MODELS ARE SHOWING POTENTIAL FOR 60 OVER FAR
SOUTHWEST NEBRASKA. HAVEN/T GONE THAT WARM...BUT UPPER 50S IS NOW
IN THE CURRENT FORECAST.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 338 AM CST FRI NOV 21 2014
ALL MODELS IN GOOD AGREEMENT IN THE NEAR TERM AND POINTING TOWARDS
A WARM UP TODAY. SOUTHERLY FLOW AND INCREASING MID CLOUDS WILL
HELP TO KEEP TEMPERATURES UP EARLY THIS MORNING WITH A WARM START
TO THE DAY. WARM FRONT WILL CONTINUE TO MOVE TO THE NORTHEAST
ACROSS THE NORTHERN PLAINS TODAY. STILL ABOUT AN INCH OF SNOW
ALONG AND NORTH OF HIGHWAY 20 TO THE SOUTH DAKOTA BORDER.
TEMPERATURE GRIDS WILL CONTINUE TO REFLECT THIS SNOW FIELD TODAY
AND TONIGHT. 850MB TEMPERATURES CLIMB TOWARDS 12C BY 22/18Z.
BELIEVE TEMPERATURE FORECAST MAY BE UNDER DONE AGAIN TODAY BUT
HAVE PUSHED THE ENVELOPE. HIGH TEMPERATURES YESTERDAY OUT DID
GUIDANCE BY A 1 CATEGORY AND BELIEVE THIS IS POSSIBLE AGAIN TODAY
WITH MODEL BIAS BASED ON SNOW COVER. PARTLY TO MOSTLY CLOUDY TODAY
WITH CLOUDS DECREASING THIS EVENING AND ANOTHER MILD EVENING WITH
GOOD WARM AIR ADVECTION. LOW TEMPERATURES IN THE 20S. DRY.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 338 AM CST FRI NOV 21 2014
12Z SATURDAY AND BEYOND. A LEE SIDE SFC TROUGH WILL DEEPEN THROUGH
THE DAY ON SATURDAY...ALLOWING FOR A SOUTHWEST TRAJECTORY OF THE
LOWER TROPOSPHERIC WIND ACROSS THE ENTIRE CWA. H85 TEMPERATURES BY
00Z SUNDAY WILL BE IN THE 9 TO 11 C RANGE...WHICH WOULD PROMOTE
HIGHS GENERALLY IN THE 50S AND 60S FOR MOST LOCATIONS. GUIDANCE AS
OF LATE HAS SHOWN A COOL BIAS WITH THE NAM IMPACTED STILL BY
PERCEIVED SNOWPACK...THUS THE HIGH TEMPERATURE FORECAST WILL TRENDED
TOWARD THE WARMER MAV...AND THEN MANUALLY ADJUSTED A FEW DEGREES
WARMER FROM THERE. THE FORECAST CALLS FOR LOWER 60S FOR ALL
LOCATIONS ALONG AND SOUTH OF INTERSTATE 80 NOW. A COLD FRONT
HOWEVER WILL COOL TEMPERATURES FOR SUNDAY SOME 10-15 DEGREES. LIGHT
PRECIPITATION...OR POSSIBLY FLURRIES/SPRINKLES WILL BE POSSIBLE
EARLY SUNDAY WITH THE PASSAGE OF THE UPPER TROUGH...HOWEVER BOTH THE
NAM AND THE GFS INDICATE A LESS THAN IDEAL MOISTURE PROFILE. FOR
THIS WOULD LIKE TO SEE ANOTHER SET OF MODEL RUNS BEFORE ADDING A QPF
MENTION. NOTE HOWEVER A LIGHT SNOW MENTION WAS CONTINUED EARLY
SUNDAY ACROSS NORTHWEST NEBRASKA AS THE MODELS CONTINUE TO SHOW
BETTER MOISTURE IN PLACE.
SNOW CHANCES REMAIN ACROSS NORTHERN NEBRASKA SUNDAY NIGHT INTO
MONDAY AS A CLOSED UPPER LEVEL LOW MOVES FROM THE EASTERN DAKOTAS
TOWARDS THE GREAT LAKES REGION. AT THIS POINT MODEL AGREEMENT IS
LACKING...THUS WILL MAINTAIN ONLY A SLIGHT CHANCE MENTION. NORTHWEST
FLOW ALOFT BEHIND THE PASSING UPPER LOW WILL KEEP CONDITIONS
SEASONAL FOR EARLY NEXT WEEK. HIGHS WILL BE COOL ON MONDAY WITH
UPPER 20S ANTICIPATED ACROSS OUR NORTHERN ZONES...LOWER 40S FOR THE
SOUTH. LOWS IN THE TEENS AND 20S SHOULD PREVAIL BOTH MONDAY AND
TUESDAY MORNING. TEMPERATURES WARM SLIGHTLY FOR TUESDAY AS A LEE
TROUGH DEEPENS OFF THE HIGH PLAINS ALLOWING FOR A RETURN OF LOWER
TROPOSPHERIC SOUTHWEST FLOW. MOST LOCATIONS SHOULD SEE HIGH IN THE
UPPER 30S TO LOW 40S...ACROSS SOUTHWEST NEBRASKA AND THE FAR EASTERN
PANHANDLE...MID 40S WILL BE POSSIBLE.
LATE TUESDAY AND BEYOND THE MODELS CONTINUE TO STRUGGLE WITH
CONSISTENCY AND GENERAL AGREEMENT. BOTH THE GFS AND ECMWF DEPICT
ANOTHER SLUG OF ARCTIC AIR ARRIVING ATOP THE CENTRAL PLAINS SOMETIME
MID-WEEK. IN ADDITION...BOTH MODELS GENERATE LIGHT QPF AT TIMES
ACROSS PORTIONS OF THE FORECAST AREA WITH FAVORABLE UPPER JET
DYNAMICS AND THE PASSAGE OF AN UPPER TROUGH/S/. BUT THE ECMWF HAS
FLOPPED FROM 24 HOURS AGO...NOW FAVORING A WARMER SOLUTION FOR
THURSDAY AND BEYOND...WHEREAS THE GFS IS DEPICTING SIGNIFICANTLY
COOLER TEMPERATURES /THIS IS A FLOP AS WELL/. FOR COMPARISON BY 00Z
FRIDAY...THE GFS AND ECMWF ARE UPWARDS TO 20C DIFFERENT AT H85 OVER
WESTERN PORTIONS OF THE FORECAST AREA AS THE ECMWF IS QUICK TO FORCE
THE COLD AIR EAST /BIG REVERSAL FROM 24 HOURS AGO/. THE GFS
SUGGESTS BELOW AVERAGE TEMPERATURES CONTINUING THROUGH THE REMAINDER
OF THE WEEK AND INTO THE WEEKEND...AGAIN AND CONTRADICTION TO 24
HOURS AGO BUT IS SLOWER WITH THE ARRIVAL OF THE ARCTIC INTRUSION.
GIVEN THE LONG RANGE MODELS ARE SHOWING LITTLE IF ANY
AGREEMENT...FELT THE BEST COURSE OF ACTION WAS TO EMPLOY THE BLENDED
FORECAST APPROACH /SUPERBLEND/. THE SUPERBLEND /POSSIBLY
COMPROMISED FROM THE PREVIOUS COLDER ECMWF FORECAST/ SEEMS TO FAVOR
A SLIGHTLY COOLER SOLUTION. THIS SUGGESTS HIGHS ON THURSDAY IN THE
20S FOR MUCH OF THE FORECAST AREA WITH THE POSSIBILITY OF LIGHT
SNOW. OBVIOUSLY IMPACTS TO HOLIDAY TRAVEL COULD BE GREAT GIVEN THE
TIMING OF THE POTENTIAL SNOW/ARCTIC INTRUSION...IT MUST BE STATED
THAT FORECAST CONFIDENCE IS LOW BEYOND TUESDAY EVENING...ANTICIPATE
FORECAST CHANGES AS THE MODELS EVENTUAL CONVERGE ON A SOLUTION.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 541 AM CST FRI NOV 21 2014
A WARM FRONT WILL MOVE EAST ACROSS NEBRASKA TODAY WITH SOUTH TO
SOUTHWEST WINDS LESS THAN 10KTS AND CEILINGS AOA 10KFT.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BROOKS
SHORT TERM...POWER
LONG TERM...JACOBS
AVIATION...POWER
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
438 AM PST FRI NOV 21 2014
.SYNOPSIS...A WEAKENING PACIFIC STORM SYSTEM WILL BRING CLOUDY SKIES
AND A FEW AREAS OF SHOWERS THROUGH THIS MORNING. CONDITIONS ARE
EXPECTED TO IMPROVE AREAWIDE BY THE AFTERNOON. A SECOND SYSTEM WILL
BRING GUSTY WINDS TO PORTIONS OF THE SOUTHERN GREAT BASIN AND
MOJAVE DESERT SATURDAY AND SUNDAY.
&&
.UPDATE...SCATTERED SHOWERS/THUNDERSTORMS OCCURRING IN SOUTHWEST SAN
BERNARDINO COUNTY AND WESTERN RIVERSIDE COUNTY UNDER CORE OF
SHORTWAVE. SHORTWAVE PROGGED TO SLIDE SOUTHEAST TOWARD YUMA THROUGH
THE REST OF THIS MORNING. SATELLITE SHOWS CLOUD TOPS WARMING AND
DISSIPATING ACROSS SOUTHERN NEVADA SO RAIN CHANCES NOT LOOKING GOOD
AROUND HERE SO HAVE LOWERED POPS.
&&
.SHORT TERM...TODAY THROUGH SUNDAY NIGHT...MID AND HIGH LEVEL CLOUDS
HAVE BEEN WIDESPREAD ACROSS THE REGION OVERNIGHT. HOWEVER
PRECIPITATION AND LOW CLOUD DECKS HAVE BEEN HARD TO COME BY. AS OF
10Z THERE WAS SOME PRECIPITATION AND EVEN A COUPLE WEAK
THUNDERSTORMS BEGINNING TO WANDER THROUGH SOUTHWESTERN SAN
BERNARDINO COUNTY AND THE HRRR HAS HAD THE BEST HANDLE ON THIS OVER
THE LAST COUPLE HOURS. THIS AREA OF PRECIPITATION IS ASSOCIATED WITH
AN UPPER LEVEL LOW CIRCULATION THAT WAS CENTERED JUST NORTH OF
BARSTOW. THIS LOW WILL PUSH SOUTHEAST TOWARDS YUMA AND FAR SOUTHERN
ARIZONA AS THE DAY GOES ON. THE MOST RECENT MODELS HAVE TRENDED MUCH
DRIER FOR THIS MORNING AND PRECIPITATION CHANCES WERE REDUCED ACROSS
THE BOARD. FOR LAS VEGAS I DID LEAVE IN A SLIGHT CHANCE OF
PRECIPITATION...WITH THE BEST CHANCES BETWEEN 4AM AND 8AM THIS
MORNING. IT`S BECOMING INCREASINGLY LIKELY THAT THERE WILL JUST BE A
FEW VIRGA SHOWERS AROUND THE VALLEY NEAR SUNRISE. PRECIPITATION
CHANCES LOOK TO END ACROSS THE FORECAST AREA BY 18Z AND POPS WERE
REMOVED FOR THIS AFTERNOON. EXPECT THE SUN TO COME OUT ACROSS MOST
OF THE REGION THIS AFTERNOON.
THE NEXT SHORTWAVE IS EXPECTED TO BRUSH THE GREAT BASIN LATE
SATURDAY THROUGH SUNDAY MORNING. THIS WAVE WILL BRING ADDITIONAL
CHANCES FOR PRECIPITATION FOR THE NORTHERN PORTIONS OF
INYO...ESMERALDA...NYE AND LINCOLN COUNTIES SATURDAY AND SATURDAY
NIGHT. ONE POINT OF CONCERN ARE WINDS ACROSS THE SIERRA SATURDAY
AFTERNOON/EVENING AND THE POTENTIAL FOR A BRIEF PERIOD OF DOWNSLOPE
WINDS. WHILE THE DOWNSLOPE SIGNATURE ISN`T ALL THAT IMPRESSIVE...
LOCAL HIGH RESOLUTION GUIDANCE DOES INDICATE THAT WINDS COULD REACH
ADVISORY [GUSTS OVER 58 MPH] OR EVEN WARNING [GUSTS OVER 70 MPH]
LEVELS DURING THIS TIMEFRAME...PRIMARILY ABOVE 6000 FEET. WE WILL
CONTINUE TO MONITOR THIS SITUATION OVER THE NEXT 12-24 HOURS AND MAY
NEED TO ISSUE WIND HIGHLIGHTS. THIS SYSTEM WILL ALSO BRING A DECENT
PUSH OF NORTHERLY WINDS ACROSS THE AREA SUNDAY...WITH THE STRONGEST
WINDS LIKELY ACROSS FAVORED AREAS SUCH AS CENTRAL NYE COUNTY AND THE
COLORADO RIVER VALLEY.
TEMPERATURES ARE EXPECTED TO BE AROUND TO SLIGHTLY ABOVE NORMAL
THROUGH THE SHORT TERM PERIOD...TRANSLATING INTO THE MID-UPPER 60`S
FOR THE LAS VEGAS VALLEY.
.LONG TERM...MONDAY THROUGH THURSDAY...A FINAL SHORTWAVE WILL BE
MOVING THROUGH THE FOUR CORNERS REGION MONDAY. THE SYSTEM LOOKS TO
BE DRY FOR LINCOLN AND MOHAVE COUNTIES BUT WILL BRING A CONTINUATION
OF BRISK NORTH WINDS, ESPECIALLY TO THE COLORADO RIVER VALLEY SOUTH
OF LAKE MOHAVE. TEMPERATURES WILL BE IN THE UPPER 40S TO LOWER 50S
FROM GOLDFIELD EAST TO CALIENTE. FOR THE MOJAVE DESERT HIGHS WILL
RANGE FROM THE UPPER 50S TO MID 60S.
00Z MODELS HAVE COME INTO GOOD AGREEMENT DEVELOPING A STRONG RIDGE
OVER THE AREA TUESDAY/WEDNESDAY WITH RIDGE STARTING TO FLATTEN/BREAK
DOWN ON THANKSGIVING DAY. BOTH THE GFS/EC MOS GUIDANCE SHOW HIGHS
FOR LAS VEGAS ON WEDNESDAY/THANKSGIVING DAY AROUND 70. AS VALLEY
INVERSIONS STRENGTHEN OVER TIME CHALLENGE WILL BECOME FORECASTING
HIGH TEMPERATURES AND FOR NOW UNDERCUTTING THOSE VALUES BY SEVERAL
DEGREES. A NORTH BREEZE WILL LINGER DOWN THE RIVER VALLEY THROUGH
WEDNESDAY BUT SHOULD WEAKEN FOR THANKSGIVING DAY FOR THOSE LOOKING
TO RECREATE ON THE LAKES.
&&
.AVIATION...FOR MCCARRAN...SCT-BKN CLOUDS BETWEEN 10-15 KFT THROUGH
MID MORNING BEFORE SKIES BEGIN TO CLEAR DURING THE AFTERNOON. THERE
IS A VERY SLIGHT CHANCE OF SOME RAIN/VIRGA SHOWERS AROUND THE LAS
VEGAS VALLEY THROUGH THE MORNING. WINDS ARE EXPECTED TO REMAIN
LIGHT...MAINLY UNDER 8 KTS FAVORING TYPICAL DIURNAL TRENDS.
ADDITIONAL CLOUDS MAINLY AOA 10KFT FRIDAY NIGHT.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...SCT-BKN CLOUDS BETWEEN 8-12 KFT THROUGH MID MORNING
BEFORE SKIES BEGIN TO CLEAR DURING THE AFTERNOON ACROSS MUCH OF THE
REGION. A FEW SHOWERS ARE POSSIBLE...PRIMARILY ACROSS SOUTHERN SAN
BERNARDINO COUNTY THIS MORNING. THERE WILL BE LESSER CHANCES FOR
SHOWERS ACROSS NYE...CLARK AND MOHAVE COUNTIES THROUGH THE MORNING.
WINDS WILL FAVOR TYPICAL DIURNAL PATTERNS THROUGH THE PERIOD.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTER ACTIVATION IS NOT EXPECTED.
$$
$$
UPDATE...PIERCE
SHORT TERM/AVIATION...WOLCOTT
LONG TERM.............PIERCE
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
226 AM PST FRI NOV 21 2014
.SYNOPSIS...A WEAKENING PACIFIC STORM SYSTEM WILL BRING CLOUDY SKIES
AND A FEW AREAS OF SHOWERS THROUGH THIS MORNING. CONDITIONS ARE
EXPECTED TO IMPROVE AREAWIDE BY THE AFTERNOON. A SECOND SYSTEM WILL
BRING GUSTY WINDS TO PORTIONS OF THE SOUTHERN GREAT BASIN AND
MOJAVE DESERT SATURDAY AND SUNDAY.
&&
.SHORT TERM...TODAY THROUGH SUNDAY NIGHT...MID AND HIGH LEVEL CLOUDS
HAVE BEEN WIDESPREAD ACROSS THE REGION OVERNIGHT. HOWEVER
PRECIPITATION AND LOW CLOUD DECKS HAVE BEEN HARD TO COME BY. AS OF
10Z THERE WAS SOME PRECIPITATION AND EVEN A COUPLE WEAK
THUNDERSTORMS BEGINNING TO WANDER THROUGH SOUTHWESTERN SAN
BERNARDINO COUNTY AND THE HRRR HAS HAD THE BEST HANDLE ON THIS OVER
THE LAST COUPLE HOURS. THIS AREA OF PRECIPITATION IS ASSOCIATED WITH
AN UPPER LEVEL LOW CIRCULATION THAT WAS CENTERED JUST NORTH OF
BARSTOW. THIS LOW WILL PUSH SOUTHEAST TOWARDS YUMA AND FAR SOUTHERN
ARIZONA AS THE DAY GOES ON. THE MOST RECENT MODELS HAVE TRENDED MUCH
DRIER FOR THIS MORNING AND PRECIPITATION CHANCES WERE REDUCED ACROSS
THE BOARD. FOR LAS VEGAS I DID LEAVE IN A SLIGHT CHANCE OF
PRECIPITATION...WITH THE BEST CHANCES BETWEEN 4AM AND 8AM THIS
MORNING. IT`S BECOMING INCREASINGLY LIKELY THAT THERE WILL JUST BE A
FEW VIRGA SHOWERS AROUND THE VALLEY NEAR SUNRISE. PRECIPITATION
CHANCES LOOK TO END ACROSS THE FORECAST AREA BY 18Z AND POPS WERE
REMOVED FOR THIS AFTERNOON. EXPECT THE SUN TO COME OUT ACROSS MOST
OF THE REGION THIS AFTERNOON.
THE NEXT SHORTWAVE IS EXPECTED TO BRUSH THE GREAT BASIN LATE
SATURDAY THROUGH SUNDAY MORNING. THIS WAVE WILL BRING ADDITIONAL
CHANCES FOR PRECIPITATION FOR THE NORTHERN PORTIONS OF
INYO...ESMERALDA...NYE AND LINCOLN COUNTIES SATURDAY AND SATURDAY
NIGHT. ONE POINT OF CONCERN ARE WINDS ACROSS THE SIERRA SATURDAY
AFTERNOON/EVENING AND THE POTENTIAL FOR A BRIEF PERIOD OF DOWNSLOPE
WINDS. WHILE THE DOWNSLOPE SIGNATURE ISN`T ALL THAT IMPRESSIVE...
LOCAL HIGH RESOLUTION GUIDANCE DOES INDICATE THAT WINDS COULD REACH
ADVISORY [GUSTS OVER 58 MPH] OR EVEN WARNING [GUSTS OVER 70 MPH]
LEVELS DURING THIS TIMEFRAME...PRIMARILY ABOVE 6000 FEET. WE WILL
CONTINUE TO MONITOR THIS SITUATION OVER THE NEXT 12-24 HOURS AND MAY
NEED TO ISSUE WIND HIGHLIGHTS. THIS SYSTEM WILL ALSO BRING A DECENT
PUSH OF NORTHERLY WINDS ACROSS THE AREA SUNDAY...WITH THE STRONGEST
WINDS LIKELY ACROSS FAVORED AREAS SUCH AS CENTRAL NYE COUNTY AND THE
COLORADO RIVER VALLEY.
TEMPERATURES ARE EXPECTED TO BE AROUND TO SLIGHTLY ABOVE NORMAL
THROUGH THE SHORT TERM PERIOD...TRANSLATING INTO THE MID-UPPER 60`S
FOR THE LAS VEGAS VALLEY.
.LONG TERM...MONDAY THROUGH THURSDAY...A FINAL SHORTWAVE WILL BE
MOVING THROUGH THE FOUR CORNERS REGION MONDAY. THE SYSTEM LOOKS TO
BE DRY FOR LINCOLN AND MOHAVE COUNTIES BUT WILL BRING A CONTINUATION
OF BRISK NORTH WINDS, ESPECIALLY TO THE COLORADO RIVER VALLEY SOUTH
OF LAKE MOHAVE. TEMPERATURES WILL BE IN THE UPPER 40S TO LOWER 50S
FROM GOLDFIELD EAST TO CALIENTE. FOR THE MOJAVE DESERT HIGHS WILL
RANGE FROM THE UPPER 50S TO MID 60S.
00Z MODELS HAVE COME INTO GOOD AGREEMENT DEVELOPING A STRONG RIDGE
OVER THE AREA TUESDAY/WEDNESDAY WITH RIDGE STARTING TO FLATTEN/BREAK
DOWN ON THANKSGIVING DAY. BOTH THE GFS/EC MOS GUIDANCE SHOW HIGHS
FOR LAS VEGAS ON WEDNESDAY/THANKSGIVING DAY AROUND 70. AS VALLEY
INVERSIONS STRENGTHEN OVER TIME CHALLENGE WILL BECOME FORECASTING
HIGH TEMPERATURES AND FOR NOW UNDERCUTTING THOSE VALUES BY SEVERAL
DEGREES. A NORTH BREEZE WILL LINGER DOWN THE RIVER VALLEY THROUGH
WEDNESDAY BUT SHOULD WEAKEN FOR THANKSGIVING DAY FOR THOSE LOOKING
TO RECREATE ON THE LAKES.
&&
.AVIATION...FOR MCCARRAN...SCT-BKN CLOUDS BETWEEN 6-10KFT THROUGH
MID MORNING BEFORE SKIES BEGIN TO CLEAR DURING THE AFTERNOON. THERE
IS A VERY SLIGHT CHANCE OF SOME RAIN/VIRGA SHOWERS AROUND THE LAS
VEGAS VALLEY THROUGH THE MORNING. WINDS ARE EXPECTED TO REMAIN
LIGHT...MAINLY UNDER 8 KTS FAVORING TYPICAL DIURNAL TRENDS.
ADDITIONAL CLOUDS MAINLY AOA 10KFT FRIDAY NIGHT.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...SCT-BKN CLOUDS BETWEEN 6-10KFT THROUGH MID MORNING
BEFORE SKIES BEGIN TO CLEAR DURING THE AFTERNOON ACROSS MUCH OF THE
REGION. A FEW SHOWERS ARE POSSIBLE...PRIMARILY ACROSS WESTERN AND
CENTRAL SAN BERNARDINO COUNTY THIS MORNING. THERE WILL BE LESSER
CHANCES FOR SHOWERS ACROSS INYO...NYE AND CLARK COUNTY THROUGH THE
MORNING. WINDS WILL FAVOR TYPICAL DIURNAL PATTERNS THROUGH THE
PERIOD.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTER ACTIVATION IS NOT EXPECTED.
$$
$$
SHORT TERM/AVIATION...WOLCOTT
LONG TERM.............PIERCE
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
943 PM EST SAT NOV 22 2014
.SYNOPSIS...
CLOUDS WILL INCREASE OVERNIGHT AHEAD OF A STORM SYSTEM TAKING
SHAPE IN THE GULF OF MEXICO. THIS SYSTEM WILL BRING MILD AND WET
WEATHER SUNDAY AND MONDAY AS IT LIFTS NORTHEAST. STRONG
THUNDERSTORMS WILL BE POSSIBLE LATE SUNDAY THROUGH EARLY MONDAY. A
COLD FRONT WILL CROSS THE COAST EARLY TUESDAY...STALLING OFFSHORE.
DEEPENING LOW PRESSURE WILL FORM ALONG THIS FRONT...BRINGING A COOL
WET CONDITIONS WEDNESDAY. CLEARING WEATHER IS EXPECTED THANKSGIVING
DAY WITH BELOW NORMAL TEMPERATURES THROUGH NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 640 PM SATURDAY...HIGH CLOUDS ARE OVERSPREADING THE CAROLINAS
WHILE MOISTURE ALSO INCREASES IN THE LOW LEVELS DUE TO
EAST-SOUTHEASTERLY FLOW OFF THE ATLANTIC OCEAN. IT SHOULD ONLY TAKE
ANOTHER 3-5 HOURS TO SEE MOSTLY CLOUDY TO CLOUDY SKIES IN PLACE
ACROSS THE ENTIRE FORECAST AREA...AND MORE IMPORTANTLY TO SEE RAIN
DEVELOPING ACROSS NE SOUTH CAROLINA. BASED ON THE LATEST RADAR
SUMMARY AND 23Z HRRR RUNS...I HAVE SPED UP THE INTRODUCTION OF RAIN
CHANCES TO THE FORECAST BY SEVERAL HOURS AND HAVE INCREASED POPS
THROUGH DAYBREAK AS WELL. EVEN ACROSS THE SANTEE RIVER RIVER AREA I
STILL ONLY THINK A FEW HUNDREDTHS OF AN INCH WILL FALL BEFORE
DAYBREAK. MORE SUBSTANTIAL MOISTURE ADVECTION AND SYNOPTIC FORCING
WILL ARRIVE DURING THE DAY TOMORROW.
TEMPERATURES SHOULD BE VERY NEAR THEIR LOWEST READINGS OF THE NIGHT
NOW. RADIATIONAL COOLING CONDITIONS SHOULD DETERIORATE FROM THIS
POINT FORWARD AS CLOUD COVERAGE INCREASES. AFTER DRAWING THE LATEST
HOURLY TEMPERATURE CURVES IN THE DIGITAL FORECAST I NOTED THE TEXT
FORMATTER USED THE "RISING TEMPERATURE" PHRASE FOR SOME COASTAL
ZONES TONIGHT. THIS IS GOOD AND DESCRIBES THE ANTICIPATED SHAPE OF
HOURLY TEMPERATURE CURVES NEAR THE COAST.
&&
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
AS OF 336 PM SATURDAY...PRIMARY HEADLINE THIS PERIOD...STRONG TO
SEVERE TSTM POTENTIAL LATE SUNDAY THROUGH EARLY MONDAY. LOW-LEVEL
SE WINDS WILL INTENSIFY...TRANSPORTING MOISTURE RICH GULF STREAM
AIR INTO THE COASTAL ZONES ELEVATING BOUNDARY LAYER DEWPOINTS.
A DEVELOPING AXIS OF POSITIVE MIXED-LAYERED CAPES WILL ORIENT
ITSELF ALONG OR JUST OFF THE COAST SUNDAY NIGHT THROUGH MONDAY
MORNING. THE HIGHEST HELICITY VALUES FAR PRECEDE THE MAXIMUM OF
ML-CAPE BUT SOME OVERLAP OF MODERATE CAPE/HELICITY EXISTS TO
WARRANT A CHANCE OF SEVERE STORMS...ALTHOUGH DIURNAL COOLING WILL
AND SLIGHT CHILLED INSHORE SST VALUES COULD OFFSET INCREASING
CONVECTIVE INTENSITY TRENDS.
NEXT NOTEWORTHY ITEM...PRECEDING THIS SEVERE POTENTIAL PLENTY
STRATIFORM RAIN APPEARS LIKELY...AND THE LATEST WPC QPF FORECAST
FOR SUNDAY AND MONDAY PAINTS 1.5-2.5 INCHES OF RAIN FOR OUR AREA
FOR THE 2-DAY PERIOD. STRATIFORM WILL TRANSITIONS TO CONVECTION AS
THE WARM FRONT LIFTS NORTH OF THE AREA INTO EARLY MONDAY.
EXCEPTIONALLY MILD MONDAY WITH MAXIMUM TEMPERATURES WELL INTO THE
70S IN A DEEP AND MOIST SW WIND FLOW ATOP THE AREA...AND FROPA
NEAR END OF THE PERIOD PRIOR TO DAYBREAK TUESDAY. COOLEST PORTION
OF PERIOD DAYBREAK SUNDAY WITH CLOUDS AND MIDDLE 40S. HIGHEST POP
VALUES SUNDAY NIGHT.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
AS OF 336 PM SATURDAY...LINGERING FRONT STALLED OFF THE EAST COAST
TUE INTO WED AND SHORTWAVE DROPPING INTO THE WESTERN GULF WILL
BRING RAIN TO THE AREA DURING THE MIDDLE OF NEXT WEEK. WEAK
SURFACE WAVE DEVELOPING ON THE BOUNDARY OVER SOUTHERN FL EARLY TUE
WILL BE ENHANCED BY THE AFOREMENTIONED SHORTWAVE. AS THE LOW
TRACKS NORTHEAST ALONG THE FRONT...JUST OFF THE SE COAST...RAIN
WILL SPREAD OVER MUCH OF THE CAROLINAS. WED LOOKS AS THOUGH IT
COULD BE A MISERABLE DAY WITH THE FORECAST AREA ON THE COOL SIDE
OF THE LOW AND PERIODS OF HEAVY RAIN POSSIBLE. HIGHS WED MAY STAY
IN THE MID 40S WITH AROUND 50 ALONG THE COAST AND HAVE TRENDED
HIGHS DOWN.
RAPID DRYING WILL COMMENCE LATE WED INTO WED NIGHT AS 5H TROUGH
AXIS LIFTS NORTHEAST AND DEEP DRY AIR ARRIVES. BY THU AM
PRECIPITABLE WATER VALUES WILL BE AROUND 0.40 INCH AND SOUNDINGS
SHOW STRONG DOWNWARD MOTION. LATER HALF OF THE PERIOD REMAINS A
QUESTION WITH LATEST GFS/ECMWF DISAGREEING ON THE
STRENGTH/AMPLITUDE OF THE NEXT MID LEVEL TROUGH. GFS DEVELOPS
ZONAL FLOW ALOFT FRI/SAT WHILE THE ECMWF MAINTAINS 5H TROUGHING
INTO THE START OF THE WEEKEND. BOTH SOLUTIONS WOULD RESULT IN A
DRY FORECAST BUT WITH DIFFERENCES IN TEMPERATURES AND POSSIBLY
AFTERNOON CLOUD COVER. GFS ENSEMBLES ARE NOT VERY HELPFUL WITH
ROUGHLY AN EQUAL SPLIT BETWEEN THE 2 SOLUTIONS. INHERITED FORECAST
IS BASICALLY A BLEND OF THE GFS/ECMWF AND WILL CONTINUE WITH THIS
THINKING UNTIL THERE IS BETTER AGREEMENT.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
AS OF 00Z...EXPECT VFR OVERNIGHT INTO THE MORNING HOURS ON
SUNDAY...WITH CONDITIONS GRADUALLY DETERIORATING TO MVFR AND THEN
IFR TOWARDS THE END OF THE PERIOD AS LOW CIGS AND SHRA/ISOLATED TSRA
ACCOMPANY THE NEXT APPROACHING WEATHER SYSTEM.
LIGHT WINDS WITH INCREASING HIGH CLOUDS WILL BE ON TAP FOR TONIGHT
AND THROUGH THE MORNING HOURS AHEAD OF THE NEXT APPROACHING WEATHER
SYSTEM. AS A RESULT...EXPECT VFR TO PREVAIL. ON SUNDAY...LOW TO MID
CLOUDS WILL SLOWLY INFILTRATE INTO THE AREA BY LATE MORNING...WITH
INCREASING CHANCES FOR RAIN THROUGHOUT THE DAY. HEAVY RAIN AT TIMES
AND LOWER CIGS WILL CREATE DETERIORATING CONDITIONS TO MVFR AND
EVENTUALLY IFR TOWARDS SUNDAY EVENING. THERE IS A POSSIBILITY OF
THUNDERSTORMS INTO THE EVENING HOURS...BUT GIVEN LOWER CONFIDENCE OF
TIMING AND WHILE CONTINUING TO MONITOR LATEST GUIDANCE
INFORMATION...HAVE OPTED TO NOT INTRODUCE ATTM. AS FOR
WINDS...EXPECT NORTHEAST WINDS TO BECOME SOUTHEAST BY THE
AFTERNOON/EVENING HOURS...WITH SUSTAINED WINDS AOB 10 KTS.
EXTENDED OUTLOOK...UNSETTLED WEATHER IS EXPECTED POSSIBLY THROUGH
TUESDAY...WITH OCCASIONAL SHOWERS AND MVFR/IFR CONDITIONS. VFR
TUESDAY AFTERNOON WITH POSSIBLE MVFR CONDITIONS WEDNESDAY. VFR
THURSDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 940 PM SATURDAY...NO SIGNIFICANT CHANGE ARE NEEDED TO THE
FORECAST LATE THIS EVENING. OBSERVATIONS SHOW VEERING WINDS ACROSS
THE WATERS...MAINLY E TO NE ALONG THE BEACHES WITH SE WINDS OUT AT
THE FRYING PAN SHOALS BUOY. THE WARM FRONT SHOULD MAKE RAPID
PROGRESS TOWARD THE BEACHES OVERNIGHT WITH RISING TEMPERATURES
EXPECTED. FORTUNATELY THE MASSIVE INCREASE IN WIND SPEEDS WILL HOLD
OFF UNTIL DURING THE DAY SUNDAY. SEAS 2-3 FEET (LOCALLY 4 FEET IN
THE OUTER PORTION OF THE COASTAL WATERS) SHOULD CONTINUE THROUGH THE
NIGHT.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 336 PM SATURDAY...DETERIORATING MARINE CONDITIONS SUNDAY AS SE
WINDS CRANK UP TO 15-25 KT AHEAD OF AN APPROACHING WARM FRONT. S
AND SW BLUSTERY FLOW TO FOLLOW FOR MONDAY 15-25 KT...WHILE SEAS
PEAK MAINLY SUNDAY NIGHT DURING MAXIMUM IN S-SE WIND OFFSHORE OF
6-10 FEET AND HIGHEST OUTER WATERS. STRONG TO SEVERE THUNDERSTORMS
POSSIBLE SUNDAY NIGHT THROUGH MONDAY...GULF STREAM LATE MONDAY.
VENTURING OFFSHORE IS DISCOURAGED FOR SMALL CRAFT VESSELS SUNDAY AND
MONDAY.
LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 336 PM SATURDAY...FRONT STALLED OFF THE COAST TUE WILL HELP
MAINTAIN LIGHT NORTHERLY FLOW. LOW PRESSURE DEVELOPING ON THE FRONT
LATE TUE WILL TRACK NORTHEAST WED...PASSING JUST EAST OF THE WATERS.
AS THE LOW DEVELOPS THE GRADIENT WILL TIGHTEN UP WITH SPEEDS
INCREASING TO 20 TO 25 KT WED. LOW EXITS NORTHEAST WED NIGHT WITH
WINDS BACKING TO WESTERLY AS THE LOW EXITS. GRADIENT DECREASES WITH
SPEEDS DROPPING TO 10 TO 15 KT BY THU MORNING. SEAS 2 TO 3 FT ON TUE
WILL BUILD TO 4 TO 7 FT LATE WED IN RESPONSE TO INCREASED NORTHERLY
FLOW. DEVELOPMENT OF OFFSHORE FLOW BEHIND THE EXITING LOW DROPS SEAS
TO 2 TO 4 FT WED NIGHT AND AROUND 2 FT THU.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 AM SUNDAY TO 6 AM EST TUESDAY
FOR AMZ250-252-254-256.
&&
$$
SYNOPSIS...MJC
NEAR TERM...TRA
SHORT TERM...MJC
LONG TERM...III
AVIATION...SGL
AREA FORECAST DISCUSSION
NWS RALEIGH NC
655 AM EST FRI NOV 21 2014
.SYNOPSIS...BEHIND A COLD FRONT...HIGH PRESSURE BUILDS OVER THE
REGION FOR TODAY AND SATURDAY. A STRONG LOW PRESSURE SYSTEM MOVING
FROM THE SOUTH PLAINS INTO THE GREAT LAKES SUNDAY SPREADS MOISTURE
OVER THE ENTIRE REGION DURING THE DAY SUNDAY. ANOTHER COLD FRONT
MOVES EAST ACROSS MUCH OF THE MID-ATLANTIC AND CAROLINAS ON MONDAY.
&&
.NEAR TERM /TODAY THROUGH SATURDAY NIGHT/...
AS OF 655 AM FRIDAY...
THE LATEST SURFACE ANALYSIS SHOWED THE COLD FRONT ALMOST THROUGH
CENTRAL NORTH CAROLINA WITH COOLER...DRIER AIR GRADUALLY MOVING
SOUTH. SURFACE OBSERVATIONS ALREADY SHOWED SOME DEW POINTS IN THE
NORTHWEST PIEDMONT HAVING FALLEN INTO THE TEENS...AND THESE SHOULD
CONTINUE TO MOVE SOUTH AND DRY EVEN MORE WITH SURFACE DEW POINTS
FALLING TO AROUND 10F TO THE TEENS DURING THE DAY. THE 00Z 850MB
ANALYSIS NOTED NOTICEABLE COOLING TO THE NORTHWEST...FROM 2C AT KGSO
AND -2C AT KRNK TO -11C AT KILN. 1000-850MB THICKNESSES WILL RISE
LITTLE IF AT ALL TODAY AND THE RESULT IS AROUND 10F OR SO OF COOLING
TODAY...DESPITE THE MANY TEMPERATURES IN THE 30S AS OF THIS WRITING.
SOME CIRRUS IN THE BASE OF THE BROAD UPPER TROUGH WILL BE NOTICED
ESPECIALLY THIS MORNING...BUT THE BUFR SOUNDINGS AND THE CANADIAN
CLOUD COVER MODEL SUGGEST ENOUGH DRYING ALOFT ALTHOUGH THE 300MB JET
AXIS WILL BE OVERHEAD THAT MUCH OF ANY CIRRUS SHOULD BE ABSENT BY
AFTERNOON. THE CIRRUS IS LIKELY DUE...IN PART...TO SOME UPSTREAM
ENHANCEMENT ON WATER VAPOR IMAGERY MOVING ACROSS THE OHIO VALLEY
COINCIDENT WITH A MID-LEVEL WAVE MOVING OVER THE APPALACHIANS. ONCE
THE WAVE PASSES DURING THE FIRST HALF OF THE DAY...THE HIGH CLOUDS
SHOULD START TO WANE. THE SURFACE GRADIENT IS A LITTLE TIGHTER THIS
MORNING AND BUFR SOUNDINGS ALONG WITH SOUNDINGS FROM THE RAP SUGGEST
A FEW GUSTS IN THE MIDDLE AND UPPER TEENS POSSIBLE WITH MIXING
BEFORE HIGH PRESSURE MOVING OVERHEAD TONIGHT REALLY LIGHTENS THE
WINDS.
OVERNIGHT...HIGH-LEVEL RELATIVE HUMIDITY FORECASTS FROM THE NAM AND
GFS SUGGESTS THE POTENTIAL FOR SOME THIN CIRRUS AS THE BROAD RIDGE
AXIS APPROACHES FROM THE WEST. THE CANADIAN CLOUD COVER MODEL
DEPICTS SIMILAR CONDITIONS TO THE MAV AND MET MOS...CLEAR TO FEW
CLOUDS WHICH...UNDER A LIGHT WIND AND DRY SURFACE DEW POINTS...
SHOULD ALLOW TEMPERATURES TO FALL QUICKLY TONIGHT. MAV AND MET
GUIDANCE ARE CLOSE AND TENDED TO STRAY COOLER ESPECIALLY FROM THE
TRIANGLE NORTH AND EAST WHERE ANY CIRRUS SHOULD BE EVEN THINNER AND
LESS NOTICEABLE. THINK SOME TEENS ARE QUITE POSSIBLE ESPECIALLY IN
THE TYPICALLY COOLER LOCATIONS NORTHEAST OF THE TRIANGLE. THE RECORD
LOWS AT KGSO AND KFAY APPEAR SAFE FOR SATURDAY...BUT IT WILL BE
CLOSE AT THE RELATIVELY WARM RECORD LOW AT KRDU. SATURDAY...AGAIN
WITH SOME MOSTLY THIN CIRRUS AROUND...1000-850MB THICKNESSES RISE
ABOUT 30M AND HIGHS SHOULD BE 3 TO 5 DEGREES WARMER THAN THOSE HIGHS
EXPECTED FOR TODAY.
SATURDAY NIGHT...THE 850MB THETA-E GRADIENT IS FORECAST BY THE NAM
AND GFS TO JUST BE MOVING INTO THE FAR SOUTHWEST PIEDMONT BY 12Z
SUNDAY. K INDICES ARE NEAR 0 OR NEGATIVE ON THE GFS THROUGH SATURDAY
NIGHT...AND THE NAM ONLY INCREASES VALUES INTO THE TEENS IN THE FAR
SOUTHWEST CLOSE TO 12Z SUNDAY. BUFR SOUNDINGS ARE DRY AND STABLE FOR
THE NIGHT...SAVE LATE AND MAINLY ON THE NAM WHERE THE MID-LEVEL
MOISTURE IN A SHALLOW VOLUME INCREASES A LITTLE EARLIER SOUTHWEST.
QPF IS ESSENTIALLY ZERO IN CENTRAL NORTH CAROLINA ON BOTH THE NAM
AND GFS...WITH THE 0.01 LINE ON THE NAM EDGING EVER SO CLOSE TO THE
SOUTHWEST PIEDMONT BY 12Z SUNDAY. WILL MAINTAIN A DRY FORECAST
OVERNIGHT SATURDAY ALTHOUGH A SPRINKLE IS POSSIBLE VERY LATE
SATURDAY NIGHT IN THE FAR SOUTHWEST IF ANY CAN WORK THROUGH WHAT
WILL BE A DRY SUB-CLOUD LAYER. OVERNIGHT LOWS WILL PROBABLY BE
REACHED EARLY IN THE OVERNIGHT...WITH TEMPERATURES FALLING QUICKLY
EARLY AND THEN INCREASING HIGH CLOUDS IN PARTICULAR SLOWING ANY FALL
AND WITH POSSIBLY A MINOR RISE IN TEMPERATURES LATE OVER THE WESTERN
PIEDMONT.
&&
.SHORT TERM /SUNDAY AND SUNDAY NIGHT/...
AS OF 235 AM FRIDAY...
SOUTHERN STREAM TROUGH AND ATTENDANT DEEPENING SURFACE LOW OVER THE
SOUTHERN PLAINS/LOWER MS VALLEY SUNDAY MORNING WILL LIFT NORTHWARD
INTO THE UPPER GREAT LAKES SUNDAY NIGHT. WHILE THE BEST TROUGH
DYNAMICS REMAINS WEST OF THE MOUNTAINS...STRONG/DEEP GULF MOISTURE
TRANSPORT WITHIN THE TRANSIENT EASTWARD PROPAGATING WARM CONVEYOR
BELT WILL RESULT IN A WET SUNDAY-SUNDAY EVENING PERIOD ACROSS THE
CAROLINAS. AS PWATS INCREASE TO 1.5-1.75"(2 SD ABOVE NORMAL)...LOOK
FOR POPS TO QUICKLY RAMP UP SW TO NE LATE SUNDAY MORNING THROUGH THE
AFTERNOON VIA SURGE OF ISENTROPIC LIFT/WAA ATTENDANT TO A NORTHWARD
LIFTING WARM FRONT...AND FURTHER AUGMENTED BY DPVA AHEAD OF
SHORTWAVE DISTURBANCES EJECTING NEWD AHEAD OF THE AFOREMENTIONED
PRIMARY TROUGH LIFTING THROUGH THE TN AND OHIO VALLEY. EXPECT
WIDESPREAD RAINFALL AMOUNTS OF A 0.50" TO AN 1.0". BULK OF PRECIP
LOOKS TO FALL OVER THE AREA BETWEEN 18Z SUNDAY TO 06Z MONDAY WITH
LIGHT RAIN...DRIZZLE AND/OR AREAS OF FOG THROUGH MONDAY MORNING AS
WE LOSE SATURATION ALOFT.
IMPRESSIVE LOW-LEVEL KINEMATIC WIND FIELDS FUELED BY A 60-65KT LOW-
LEVEL JET COUPLED WITH ENHANCED NEAR SURFACE HELICITY/SHEAR ALONG A
NORTHWARD RETREATING WEDGE FRONT LOOKS TO HAVE LIMITED BUOYANCY TO
WORK WITH MODELS KEEPING THE UNSTABLE PORTION OF THE WARM SECTOR
NEAR OR OFF THE SE COAST. WILL CONTINUE TO MONITOR FOR ANY INLAND
INTRUSION OF UNSTABLE AIR INTO INLAND AREAS...BUT BASED ON RECENT
TRENDS WILL KEEP THUNDER OUT OF THE FORECAST.
IN-SITU DAMMING FROM THE OFFSHORE HIGH AND WIDESPREAD RAIN WILL
RESULT IN A SLOW RISE IN TEMPERATURES DURING THE DAY ON
SUNDAY...UNTIL THE WARM FRONT LIFTS NORTH THROUGH THE AREA DURING
THE LATE AFTERNOON/EVENING HOURS. DAYTIME HIGHS WILL OCCUR AFTER
SUNSET IN MANY LOCATIONS WITH TEMPERATURES HOLDING STEADY OR QUITE
POSSIBLY WARM OVERNIGHT. DAYTIME TEMPERATURES HOLDING IN THE 50S
ACROSS THE NW PIEDMONT...WITH 60S ACROSS THE SE.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 235 AM FRIDAY...
MONDAY AND MONDAY NIGHT: IN THE MIDST OF THE UPSTREAM TROUGH OVER
THE CENTRAL US RELOADING...MID-LEVEL DRY AIR INTRUSION FROM THE WEST
AND THE LACK OF APPRECIABLE FORCING WILL RESULT IN MOSTLY DRY
CONDITIONS DURING THE DAY ON MONDAY. MODELS ARE STILL TRYING TO
GENERATE A LITTLE PRECIP UNTIL THE SFC COLD FRONT MOVES THE AREA
MONDAY EVENING/NIGHT...BUT RECENT MODEL TRENDS TO KEEP THE BULK OF
PRECIP EAST OF THE AREA. WILL HANG ON TO SLIGHT TO SMALL CHANCE POPS
WITH HIGHEST CHANCE IN THE EAST. LINGERING LOW-LEVEL MOISTURE
TRAPPED UNDERNEATH A STRONG MID-LEVEL CAP WILL RESULT IN CONTINUED
CLOUDY CONDITIONS ON MONDAY. EVEN WITH THIS OVERCAST/BROKEN CLOUD
DECK...TEMPERATURES IN THE WARM SECTOR WILL WARM INTO THE 60S NW TO
70S SE ON MONDAY.
TUESDAY THROUGH THURSDAY: TUESDAY IS SHAPING UP AS A DRY DAY ACROSS
THE AREA WITH THE STALLED FRONT EAST OF THE AREA WHILE WEAK HIGH
PRESSURE RIDGES IN FROM THE WEST WITH CAA IN THE WAKE OF MONDAY
NIGHT FROPA DROPPING TEMPERATURES BACK TO NEAR NORMAL. THERE IS THEN
A BIT OF UNCERTAINTY REGARDING THE APPROACH OF THE NEXT BATCH OF
SHORTWAVE ENERGY TRAVERSING EASTWARD WITHIN THE BASE OF THE LONGWAVE
TROUGH AND ASSOCIATED SFC CYCLOGENESIS ALONG THE OFFSHORE FRONTAL
ZONE. THE LATEST GFS AND EC HAVE TRENDED WETTER DURING THE TUESDAY
NIGHT-WEDNESDAY PERIOD...WITH PRECIP DEVELOPING INLAND IN THE COOL
SECTOR. FOR NOW...WILL ADD A SLIGHT CHANCE POPS TO COASTAL/EASTERN
PORTIONS OF THE FORECAST AREA...WITH TEMPERATURES RETURNING TO BELOW
NORMAL AS THE UPPER TROUGH MOVES INTO THE EASTERN US.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AS OF 655 AM FRIDAY...
FOR THE 12Z VALID TAF PERIOD...VFR CONDITIONS CONTINUE WITH MOSTLY
FEW-TO-SCATTERED HIGH CLOUDS. THIS MORNING...A BRIEF PERIOD OF
BROKEN HIGH CLOUDS IS POSSIBLE BEFORE CLEARING LATER IN THE MORNING.
THE SURFACE GRADIENT WILL INCREASE THIS MORNING HOURS SUCH THAT
MODEL SOUNDINGS SUGGEST A FEW NORTHERLY GUSTS INTO THE TEENS KNOTS
WITH MIXING THIS MORNING. AS THE SURFACE HIGH BUILDS OVERHEAD...
WINDS SHOULD BECOME LIGHTER AS THEY VEER LATER IN THE DAY WITH MANY
CALM OR VERY LIGHT SURFACE WINDS TAKING PLACE AFTER SUNSET.
BEYOND THE 12Z VALID TAF PERIOD...VFR CONDITIONS CONTINUE SATURDAY
THROUGH SATURDAY NIGHT. AS MOISTURE AND PRECIPITATION SPREAD
NORTHEAST OVER CENTRAL NORTH CAROLINA SUNDAY...CONDITIONS SHOULD
DETERIORATE THROUGH MVFR TO IFR IN MOST PLACES AND CONTINUE SUB-VFR
AT LEAST THROUGH SUNDAY NIGHT. AREAS OF MVFR CEILINGS ARE POSSIBLE
INTO MONDAY WITH GUSTY SOUTHWEST WINDS WHICH COULD REACH 40KT BY
2000FT ALOFT IF THE GFS MODEL VERIFIES. VFR CONDITIONS SHOULD RETURN
BY TUESDAY WITH SOME AREAS OF MID-LEVEL CLOUDS OVER A LIGHTER
SURFACE WIND VEERING NORTHERLY BEHIND A COLD FRONT THAT MOVES
THROUGH LATE MONDAY. THERE IS A CHANCE OF LIGHT RAIN MAINLY TOWARD
KFAY AND KRWI LATE TUESDAY ON THE WEST SIDE OF LOW PRESSURE THAT
MOVES ALONG THE FRONT WHICH WILL LOCATED THEN JUST OFF THE CAROLINA
COAST.
&&
.CLIMATE...
RECORD LOW: GSO RDUFAY
SAT 11/22 - 13 IN 1914 21 IN 2008 20 IN 2000
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...DJF
SHORT TERM...CBL
LONG TERM...CBL
AVIATION...DJF
CLIMATE...RAH
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
933 PM CST SAT NOV 22 2014
.UPDATE...
ISSUED AT 933 PM CST SAT NOV 22 2014
THE 635PM UPDATE IS ACTUALLY COMING TRUE FOR THE MOST PART. THE
ONE THING WE CONTINUE TO WATCH IS IF RAIN CAN FALL IN AREAS WHERE
THE TEMPERATURE IS BELOW FREEZING. THERE IS AN AREA OF BELOW
FREEZING TEMPERATURES FROM LANGDON TO CAVALIER TO GRAFTON...WHERE
THE CURRENT RADAR RETURNS ARE HEADED TOWARD. HOWEVER...AS THIS
RAIN WENT OVER HARVEY ONLY SCATTERED CLOUDS WHERE REPORTED...SO IT
MAY NOT EVEN BE ENOUGH TO WET THE GROUND. WILL CONTINUE TO MONITOR
CLOSELY (AND STILL THINK TEMPS WILL RISE A BIT IN THE NEXT HOUR OR
TWO). THE NEXT BATCH OF POSSIBLE RAIN IS DEVELOPING ACROSS
NORTHWEST SOUTH DAKOTA...AND SHOULD AFFECT WEST CENTRAL MINNESOTA
AFTER MIDNIGHT.
NEIGHBORING FORECAST OFFICES HAVE ISSUED A DENSE FOG ADVISORY ACROSS
OUR WEST CENTRAL MINNESOTA COUNTIES. THIS MAKES SENSE CONSIDERING
THAT THIS AREA HAS A DECENT SNOWPACK WITH MELTING TODAY.
CURRENTLY...THERE ARE NOT ANY 1/4SM VSBYS...AND THE 1/2SM VSBYS ARE
LIMITED TO THE AREAS SOUTH OF THIS FA.
UPDATE ISSUED AT 635 PM CST SAT NOV 22 2014
GAINING SOME CONFIDENCE IN THE FORECAST FOR TONIGHT. WATER VAPOR
IMAGERY INDICATES A FEATURE WITHIN CENTRAL NORTH DAKOTA...LIKELY
RESPONSIBLE FOR THE AREA OF RAIN SEEN ON RADAR. DID INCREASE POPS
ACROSS THE DEVILS LAKE BASIN TO 40% FOR THIS ACTIVITY...BUT STILL
DO NOT THINK IT WILL BE HEAVY OR WIDESPREAD. RAP INDICATES 925MB
TEMPS INCREASE THIS EVENING...AND WITH ALL SITES CURRENTLY AT OR
ABOVE FREEZING WILL GO ALL LIQUID FOR THIS ACTIVITY. IN
FACT...WHEREVER MODELS INDICATE QPF TONIGHT THEY ALSO INCREASE
925MB TEMPS...SO FEEL THAT THE FREEZING RAIN THREAT IS VERY
MINIMAL. THINKING THE ONLY REAL CHANCE FOR MIXED PRECIP WILL BE
THE LEADING EDGE OF THE DEFORMATION PRECIP LATER TOMORROW...BUT
EVEN THAT THREAT APPEARS MINIMAL. DID ADJUST THE GRIDS TO DECREASE
THE MIXED PRECIP THREAT.
THE OTHER CONCERN FOR TONIGHT WILL BE FOG POTENTIAL. LOW
CLOUDS/FOG HAVE ALREADY ARRIVED INTO THE SOUTHERN RED RIVER VALLEY
AND WADENA AREA. HRRR/RAP HANDLING THESE CIGS BEST...AND FOLLOWING
THEIR LEAD MOST AREAS ALONG AND EAST OF THE VALLEY WILL BE
AFFECTED BY MIDNIGHT. ADJUSTED THE SKY GRIDS...AND EXPANDED THE
PATCHY FOG MENTION. NOT SURE HOW DENSE FOG WILL BECOME...AND WILL
MONITOR.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 317 PM CST SAT NOV 22 2014
VERY TRICKY FCST TONIGHT INTO SUNDAY. WILL CONTINUE WITH SPS
MENTIONING SOME LIGHT MIXED PRECIP TONIGHT AND THEN WIND AND SNOW
POTENTIAL LATER SUNDAY INTO SUNDAY NIGHT.
WATER VAPOR SHOWS MAIN UPPER LOW WEST OF REGINA SASK AT MID
AFTN...AND THIS WILL MOVE EAST. MAIN SNOWS WITH THIS NORTH OF THE
UPPER LOW AND THIS WILL TRANSLATE EAST INTO CENTRAL MANITOBA
TONIGHT INTO SUNDAY. NOW JUST SOUTH AND EAST OF THE UPPER LOW
THERE ARE SEVERAL WEAK DISTURBANCES AND LIGHT PRECIP MOVING
THROUGH. THESE ARE NOT PICKED UP BY MODELS VERY WELL. ONE AREA OF
PRECIP IS IN SW MANITOBA INTO THE ROLLA AREA WITH LIGHT MIXED
PRECIP. MOST OF IT IS CANADA AND TEMPS ON THE U.S. SIDE JUST ABOVE
FREEZING. ANOTHER WAVE WITH SOME LIGHT RAIN AROUND DICKINSON.
UNSURE ABOUT THIS ONE AS SOME MODELS DRY IT UP BUT WOULD THINK
SOME CHANCES OF LIGHT PRECIP MAKING INTO PARTS OF ERN ND LATER
THIS EVE. TEMPS TOO A BIT TRICKY AS IN WARM SECTOR SO TEMP FALL
NOT GREAT BUT THEY COULD DROP INTO THE 30-34 RANGE MAKING FOR SOME
TRICKY PTYPE ISSUES. FOR NOW KEPT THE BROADBRUSH MIXED PRECIP
WORDING AS GIVEN BY TOP DOWN METHOD. CONFIDENCE IS LOW TONIGHT.
ALSO OVERNIGHT NORTHWESTERN EDGE OF LOW CLOUDS AND FOG MAY BRUSH
FAR SOUTHEASTERN FCST AREA AND SOME FOG MAY SPREAD INTO FAR
SOUTHEAST AND EAST CENTRAL AS WELL. 925 MB WINDS DO TURN A BIT
MORE SOUTHWEST TONIGHT AND SUGGEST MOST OF IT WILL STAY IN DLH/MPX
FCST AREA.
FOR SUNDAY...NOT EXPECTING TOO MUCH TO START BUT COULD BE SOME
GRUNGE AND FOG IN THE FAR EAST...BUT OVERALL EXPECT THAT VERY
MOIST AIRMASS TO BE EAST OF US WITH OUR AREA IN 850 MB DRY SLOT
SUNDAY MORNING. SFC LOW WILL MOVE INTO SOUTHWESTERN MANITOBA 15Z
SUN AND THEN EAST ALONG THE BORDER TOWARD WARROAD BY SUN EVE.
WINDS WILL TURN NORTHWEST AND INCREASE QUICKLY AS LOW PASSES BY
AND SOME LIGHT SNOW WILL SPREAD SOUTH. HOWEVER...LATEST 12Z AND
18Z MODEL RUNS KEEP BACKING OFF ON SNOW AMOUNTS IT SEEMS SOUTH OF
THE BORDER WITH IDEA OF 1-2 NORTH OF HWY 2 (IF THAT) AND THEN VERY
LIGHT AMOUNTS SOUTH OF THERE. WIND WITH SOME FALLING SNOW WILL
RESULT IN LOW VSBYS ISSUES. BUT WITH MODELS DOWNPLAYING SNOW
AMOUNTS NOW UNSURE HOW FAR SOUTH SNOW WILL GET AND SINCE MAIN
THREAT IS 21Z AND AFTER SUNDAY WILL LET SPS RIDE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 317 PM CST SAT NOV 22 2014
COLD AND WINDY MONDAY WITH LINGERING LIGHT SNOW EAST AND AREAS OF
BLOWING SNOW IN OPEN AREAS EVEN IF JUST A LIGHT SNOW COVER. HIGH
PRESSURE MOVES IN MON NIGHT. NEXT SHORT WAVE TO MOVE SOUTHEAST
INTO THE AREA LATER TUES AFTN/NIGHT. 06Z GFS AND 00Z ECMWF QUITE
BULLISH WITH PRECIP BUT 12Z GFS NOW WEAK AGAIN AND 12Z ECMWF
WEAKER BUT STILL SHOWS POTENTIAL FOR ACCUMS WITH SYSTEM MOSTLY
TUES NIGHT.
FOR TUE NIGHT THROUGH SATURDAY...BASICALLY STAY ENTRENCHED IN
NORTHWEST FLOW ALOFT. WILL HAVE TO DEAL WITH THE FIRST EXITING
SYSTEM TUE NIGHT. 12Z GFS HAS NOW BECOME THE WEAKEST MODEL WITH THE
ECMWF/GEM HANGING ONTO PCPN THE LONGEST OR INTO WED MORNING. THEN
THERE IS MODEL DISAGREEMENT IN HOW FAST THE NEXT SYSTEM SPREADS IN
WED NIGHT. ECMWF KEEPS SFC HIGH OVER THE AREA WHILE THE GFS SPREADS
A SWATH OF LIGHT SNOW ACROSS THE FAR SOUTHERN FA. HAVE GONE MORE
WITH THE GFS ROUTE FOR NOW BUT KEPT CHANCES QUITE LOW. SFC HIGH
STAYS IN CONTROL KEEPING IT QUIET BUT COLD THU/FRI. COULD BE A
LITTLE MORE LIGHT SNOW ACROSS THE FAR SOUTH ON FRI NIGHT OR SAT BUT
AGAIN IT LOOKS PRETTY MINIMAL.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 635 PM CST SAT NOV 22 2014
RAP/HRRR APPEAR TO BE HANDLING THE LOW CLOUD/FOG APPROACHING FROM
THE SOUTH. THIS GUIDANCE SUGGESTS THESE LOW CLOUDS/FOG WILL
CONTINUE TO RAPIDLY ADVECT NORTHWARD THROUGH THE EVENING
HOURS...AFFECTING SITES ALONG AND EAST OF THE RED RIVER VALLEY.
THUS...IFR/LIFR CONDITIONS EXPECTED TO MOVE INTO THE
KFAR/KGFK/KTVF/KBJI SITES THIS EVENING...WITH A PERIOD OF VFR
CONDITIONS FOR A GOOD PART OF THE DAY ON SUNDAY BEFORE A COLD
FRONT BRINGS WINDY CONDITIONS...SNOW SHOWERS...AND AT LEAST MVFR
CONDITIONS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...TG
SHORT TERM...RIDDLE
LONG TERM...GODON/RIDDLE
AVIATION...TG
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
635 PM CST SAT NOV 22 2014
.UPDATE...
ISSUED AT 635 PM CST SAT NOV 22 2014
GAINING SOME CONFIDENCE IN THE FORECAST FOR TONIGHT. WATER VAPOR
IMAGERY INDICATES A FEATURE WITHIN CENTRAL NORTH DAKOTA...LIKELY
RESPONSIBLE FOR THE AREA OF RAIN SEEN ON RADAR. DID INCREASE POPS
ACROSS THE DEVILS LAKE BASIN TO 40% FOR THIS ACTIVITY...BUT STILL
DO NOT THINK IT WILL BE HEAVY OR WIDESPREAD. RAP INDICATES 925MB
TEMPS INCREASE THIS EVENING...AND WITH ALL SITES CURRENTLY AT OR
ABOVE FREEZING WILL GO ALL LIQUID FOR THIS ACTIVITY. IN
FACT...WHEREVER MODELS INDICATE QPF TONIGHT THEY ALSO INCREASE
925MB TEMPS...SO FEEL THAT THE FREEZING RAIN THREAT IS VERY
MINIMAL. THINKING THE ONLY REAL CHANCE FOR MIXED PRECIP WILL BE
THE LEADING EDGE OF THE DEFORMATION PRECIP LATER TOMORROW...BUT
EVEN THAT THREAT APPEARS MINIMAL. DID ADJUST THE GRIDS TO DECREASE
THE MIXED PRECIP THREAT.
THE OTHER CONCERN FOR TONIGHT WILL BE FOG POTENTIAL. LOW
CLOUDS/FOG HAVE ALREADY ARRIVED INTO THE SOUTHERN RED RIVER VALLEY
AND WADENA AREA. HRRR/RAP HANDLING THESE CIGS BEST...AND FOLLOWING
THEIR LEAD MOST AREAS ALONG AND EAST OF THE VALLEY WILL BE
AFFECTED BY MIDNIGHT. ADJUSTED THE SKY GRIDS...AND EXPANDED THE
PATCHY FOG MENTION. NOT SURE HOW DENSE FOG WILL BECOME...AND WILL
MONITOR.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 317 PM CST SAT NOV 22 2014
VERY TRICKY FCST TONIGHT INTO SUNDAY. WILL CONTINUE WITH SPS
MENTIONING SOME LIGHT MIXED PRECIP TONIGHT AND THEN WIND AND SNOW
POTENTIAL LATER SUNDAY INTO SUNDAY NIGHT.
WATER VAPOR SHOWS MAIN UPPER LOW WEST OF REGINA SASK AT MID
AFTN...AND THIS WILL MOVE EAST. MAIN SNOWS WITH THIS NORTH OF THE
UPPER LOW AND THIS WILL TRANSLATE EAST INTO CENTRAL MANITOBA
TONIGHT INTO SUNDAY. NOW JUST SOUTH AND EAST OF THE UPPER LOW
THERE ARE SEVERAL WEAK DISTURBANCES AND LIGHT PRECIP MOVING
THROUGH. THESE ARE NOT PICKED UP BY MODELS VERY WELL. ONE AREA OF
PRECIP IS IN SW MANITOBA INTO THE ROLLA AREA WITH LIGHT MIXED
PRECIP. MOST OF IT IS CANADA AND TEMPS ON THE U.S. SIDE JUST ABOVE
FREEZING. ANOTHER WAVE WITH SOME LIGHT RAIN AROUND DICKINSON.
UNSURE ABOUT THIS ONE AS SOME MODELS DRY IT UP BUT WOULD THINK
SOME CHANCES OF LIGHT PRECIP MAKING INTO PARTS OF ERN ND LATER
THIS EVE. TEMPS TOO A BIT TRICKY AS IN WARM SECTOR SO TEMP FALL
NOT GREAT BUT THEY COULD DROP INTO THE 30-34 RANGE MAKING FOR SOME
TRICKY PTYPE ISSUES. FOR NOW KEPT THE BROADBRUSH MIXED PRECIP
WORDING AS GIVEN BY TOP DOWN METHOD. CONFIDENCE IS LOW TONIGHT.
ALSO OVERNIGHT NORTHWESTERN EDGE OF LOW CLOUDS AND FOG MAY BRUSH
FAR SOUTHEASTERN FCST AREA AND SOME FOG MAY SPREAD INTO FAR
SOUTHEAST AND EAST CENTRAL AS WELL. 925 MB WINDS DO TURN A BIT
MORE SOUTHWEST TONIGHT AND SUGGEST MOST OF IT WILL STAY IN DLH/MPX
FCST AREA.
FOR SUNDAY...NOT EXPECTING TOO MUCH TO START BUT COULD BE SOME
GRUNGE AND FOG IN THE FAR EAST...BUT OVERALL EXPECT THAT VERY
MOIST AIRMASS TO BE EAST OF US WITH OUR AREA IN 850 MB DRY SLOT
SUNDAY MORNING. SFC LOW WILL MOVE INTO SOUTHWESTERN MANITOBA 15Z
SUN AND THEN EAST ALONG THE BORDER TOWARD WARROAD BY SUN EVE.
WINDS WILL TURN NORTHWEST AND INCREASE QUICKLY AS LOW PASSES BY
AND SOME LIGHT SNOW WILL SPREAD SOUTH. HOWEVER...LATEST 12Z AND
18Z MODEL RUNS KEEP BACKING OFF ON SNOW AMOUNTS IT SEEMS SOUTH OF
THE BORDER WITH IDEA OF 1-2 NORTH OF HWY 2 (IF THAT) AND THEN VERY
LIGHT AMOUNTS SOUTH OF THERE. WIND WITH SOME FALLING SNOW WILL
RESULT IN LOW VSBYS ISSUES. BUT WITH MODELS DOWNPLAYING SNOW
AMOUNTS NOW UNSURE HOW FAR SOUTH SNOW WILL GET AND SINCE MAIN
THREAT IS 21Z AND AFTER SUNDAY WILL LET SPS RIDE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 317 PM CST SAT NOV 22 2014
COLD AND WINDY MONDAY WITH LINGERING LIGHT SNOW EAST AND AREAS OF
BLOWING SNOW IN OPEN AREAS EVEN IF JUST A LIGHT SNOW COVER. HIGH
PRESSURE MOVES IN MON NIGHT. NEXT SHORT WAVE TO MOVE SOUTHEAST
INTO THE AREA LATER TUES AFTN/NIGHT. 06Z GFS AND 00Z ECMWF QUITE
BULLISH WITH PRECIP BUT 12Z GFS NOW WEAK AGAIN AND 12Z ECMWF
WEAKER BUT STILL SHOWS POTENTIAL FOR ACCUMS WITH SYSTEM MOSTLY
TUES NIGHT.
FOR TUE NIGHT THROUGH SATURDAY...BASICALLY STAY ENTRENCHED IN
NORTHWEST FLOW ALOFT. WILL HAVE TO DEAL WITH THE FIRST EXITING
SYSTEM TUE NIGHT. 12Z GFS HAS NOW BECOME THE WEAKEST MODEL WITH THE
ECMWF/GEM HANGING ONTO PCPN THE LONGEST OR INTO WED MORNING. THEN
THERE IS MODEL DISAGREEMENT IN HOW FAST THE NEXT SYSTEM SPREADS IN
WED NIGHT. ECMWF KEEPS SFC HIGH OVER THE AREA WHILE THE GFS SPREADS
A SWATH OF LIGHT SNOW ACROSS THE FAR SOUTHERN FA. HAVE GONE MORE
WITH THE GFS ROUTE FOR NOW BUT KEPT CHANCES QUITE LOW. SFC HIGH
STAYS IN CONTROL KEEPING IT QUIET BUT COLD THU/FRI. COULD BE A
LITTLE MORE LIGHT SNOW ACROSS THE FAR SOUTH ON FRI NIGHT OR SAT BUT
AGAIN IT LOOKS PRETTY MINIMAL.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 635 PM CST SAT NOV 22 2014
RAP/HRRR APPEAR TO BE HANDLING THE LOW CLOUD/FOG APPROACHING FROM
THE SOUTH. THIS GUIDANCE SUGGESTS THESE LOW CLOUDS/FOG WILL
CONTINUE TO RAPIDLY ADVECT NORTHWARD THROUGH THE EVENING
HOURS...AFFECTING SITES ALONG AND EAST OF THE RED RIVER VALLEY.
THUS...IFR/LIFR CONDITIONS EXPECTED TO MOVE INTO THE
KFAR/KGFK/KTVF/KBJI SITES THIS EVENING...WITH A PERIOD OF VFR
CONDITIONS FOR A GOOD PART OF THE DAY ON SUNDAY BEFORE A COLD
FRONT BRINGS WINDY CONDITIONS...SNOW SHOWERS...AND AT LEAST MVFR
CONDITIONS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...TG
SHORT TERM...RIDDLE
LONG TERM...GODON/RIDDLE
AVIATION...TG
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
323 PM CST FRI NOV 21 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 323 PM CST FRI NOV 21 2014
SYSTEM TRACKING ACROSS SOUTHERN CANADA WILL CONTINUE EASTWARD
OVERNIGHT...RESULTING IN A WEAK COLD FRONT TO NEAR THE
INTERNATIONAL BORDER (MAIN RESULT WILL BE INCREASED CLOUD COVER).
THIS FEATURE WILL QUICKLY BE WASHED OUT AS THE NEXT SYSTEM
APPROACHES AND SOUTHERLY RETURN FLOW AGAIN DEVELOPS ON SATURDAY.
TEMPERATURES WILL BE THE MAIN CHALLENGE...WITH SATURDAY MAX TEMPS
SIMILAR OR EVEN SLIGHTLY WARMER (ESPECIALLY ACROSS THE SOUTHERN
FA) THAN TODAYS...BUT NOT SURE HOW MUCH WARMER.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 323 PM CST FRI NOV 21 2014
SATURDAY NIGHT-MONDAY...CONFIDENCE REMAINS LOW DURING THIS PERIOD
REGARDING HOW THE UPPER LOW WILL EVOLVE. MODELS ALL AGREE THAT THE
SOUTHERN SYSTEM WILL BE WELL EAST OF THE REGION...BUT COULD STILL
ACT TO SLOW DOWN THE NORTHERN WAVE THAT WILL AFFECT THIS REGION.
THE GFS IS SLIGHTLY QUICKER SATURDAY NIGHT AND INDICATES A BAND OF
PRECIP ASSOCIATED WITH 700MB CONVERGENCE/DEFORMATION. IF PRECIP
DOES OCCUR...IT COULD BE FREEZING RAIN/SLEET GIVEN THE WARM
TEMPERATURES ALOFT. DID INCLUDE A SCHC FOR MIXED PRECIP...BUT WITH
OTHER MODELS DRY (SLOWER) CANNOT GO WITH HIGHER POPS. THE UPPER
LOW THEN MOVES ACROSS THE REGION LATER SUNDAY INTO MONDAY. AS
THIS OCCURS...ANTICIPATE STRONG N/NW WINDS ALONG WITH SNOW
SHOWERS. AS OF NOW...WINDS ALONG AND WEST OF THE VALLEY SHOULD BE
30-40 MPH WITH HIGHER GUSTS (GIVEN EXPECTED COLD AIR
ADVECTION...SFC PRESSURE GRADIENT...AND WIND SPEEDS ALOFT). THESE
WINDS COMBINED WITH SNOW SHOWERS WOULD RESULT IN BRIEF PERIODS OF
SIGNIFICANTLY REDUCED VISIBILITY. ANY SNOW-PACK CURRENTLY ON THE
GROUND WILL NOT BE BLOW-ABLE WITH TEMPERATURES ABOVE FREEZING
DURING THE DAY TODAY...SATURDAY...AND POSSIBLY SUNDAY. SO...HOW
MUCH SNOW ACTUALLY FALLS WILL DETERMINE HOW WIDESPREAD THE BLOWING
SNOW IS DURING THIS PERIOD. STRONGEST FORCING WILL BE NORTH OF THE
INTERNATIONAL BORDER...AND GIVEN THE EXPECTED FORCING OVER THIS
REGION THINKING 1-2 INCHES AT MOST SOUTH OF THE INTERNATIONAL
BORDER (ALTHOUGH GFS INDICATES A STRONGER SYSTEM AND HIGHER QPF).
WILL CONTINUE TO MONITOR...BUT THE CURRENT MENTION IN THE HWO AND
WEATHER STORY SEEMS LIKE THE APPROPRIATE PRODUCTS AT THIS MOMENT
IN TIME.
MONDAY NIGHT-FRIDAY...500 MB TROUGH OVER THE GREAT LAKES REGION
MONDAY NIGHT INTO THURSDAY WITH FCST AREA ON THE COLD SIDE. CLOUDS
AND A CHANCE FOR SOME LIGHT SNOW WILL OCCUR TUESDAY INTO TUESDAY
NIGHT AHEAD OF A WEAK UPPER DISTURBANCE WHICH WILL MOVE THROUGH.
COLDEST AIRMASS AND HIGH PRESSURE SYSTEM TO ARRIVE WEDNESDAY-
THURSDAY. MODERATION OCCURS FRIDAY BUT LONG RANGE MODELS KEEP AREA
NEAR THE TIGHT BAROCLINIC ZONE BETWEEN COLD NORTH AND WARMER
SOUTHWEST. 12Z GFS/ECMWF SEEM IN GOOD AGREEMENT AND BLENDS WELL
WITH BLENDED MODEL DATA PROCEDURE. GOOD NEWS IS NO SIGNIFICANT
STORM SYSTEM FOR THE THANKSGIVING DAY TRAVEL PERIOD LOCALLY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1226 PM CST FRI NOV 21 2014
VFR CONDITIONS EXPECTED THRU 06Z WITH SOME PATCHY CIRRUS AND MID
CLOUD. SOUTH TO SOUTHWEST WIND OF 15 TO 25 KTS WITH A FEW HIGHER
GUSTS WILL OCCUR TODAY DIMINISHING SOME THIS EVENING. A WEAK COOL
FRONT WILL DROP SOUTH TO NEAR THE INTERNATIONAL BORDER OR A TAD
SOUTH OF IT BY 12Z SAT. RAP AND SHORT RANGE MODELS INDICATE SOME
MVFR CIGS PSBL NEAR THIS BOUNDARY OVER FAR NORTHEASTERN ND AND FAR
NORTHERN MN MOSTLY 12-18Z SATURDAY PERIOD. UNCERTAIN HOW FAR SOUTH
MVFR CIGS WILL GET HOWEVER. ANOTHER CONCERN IS LOWER CLOUDS IN
EASTERN HALF OF KANSAS. 859-925 MB WINDS WOULD SUGGEST THE TARGET
AREA FOR THOSE WILL BE IOWA....SOUTHEASTERN
MINNESOTA/WISCONSIN/ILLINOIS LATER TONIGHT INTO SATURDAY.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
SHORT TERM...TG
LONG TERM...TG/RIDDLE
AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1226 PM CST FRI NOV 21 2014
.UPDATE...
ISSUED AT 1226 PM CST FRI NOV 21 2014
TEMPERATURES ACROSS MUCH OF THE REGION (ESPECIALLY WHERE THERE IS
NO OR LIMITED SNOW COVER) ARE NEAR FORECASTED MAX TEMPS ALREADY.
WILL USE THE SHORT TERM MODELS FOR GUIDANCE AND RAISE MAX TEMPS
MOST AREAS (MID TO UPPER 30S WHERE THERE IS NO SNOW COVER...AND
NEAR FREEZING WHERE THERE IS SNOW COVER).
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 320 AM CST FRI NOV 21 2014
THE MAIN CHALLENGE WILL BE TEMPS INITIALLY...THEN THREAT FOR SOME
SNOW/BLOWING SNOW LATER SUNDAY INTO MONDAY. MODELS ARE IN VERY
GOOD OVERALL AGREEMENT...AND PREFER THE GFS THAT HAS BEEN
CONSISTENT...BUT NO REAL DIFFERENCES NOTED.
FOR TODAY...SOUTHERLY WINDS WILL BE BRISK THROUGH MOST OF THE
DAY...AND COULD GUST TO NEAR 30KT IN THE NORTHERN VALLEY AT
TIMES. THE MERCURY SHOULD CLIMB TO NEAR FREEZING ALONG AND WEST OF
THE VALLEY...AND WOULD BE THE FIRST TIME SINCE NOVEMBER 8 HITTING
32 FOR MOST AREAS. THERE WILL BE A BAND OF STRATUS MOVING NORTH
THIS MORNING...BUT EXPECT JUST HIGH CLOUDS FOR MOST. THERE COULD
BE SOME DRIFTING SNOW WHERE THERE IS SOME SNOW ON THE GROUND IN
THE NORTH VALLEY...MAINLY IN WESTERN MARSHALL/KITTSON AND POLK
COUNTIES...BUT WON/T MENTION ANY BLOWING SNOW WITH WINDS NOT QUITE
STRONG ENOUGH.
FOR TONIGHT...IT WILL BE MILD COMPARED TO RECENT NIGHTS...WITH
ZONAL FLOW ALOFT AND 850MB TEMPS ABOVE 0C.
ON SATURDAY...ANOTHER WARM DAY IS EXPECTED WITH MOST AREAS INTO
THE LOW AND PERHAPS MID 30S NEAR SNOW FREE AREAS. THERE WILL BE
MORE CLOUDS IN THE NORTH CLOSER TO DEEPER MOISTURE AHEAD OF NEXT
ALBERTA CLIPPER SYSTEM.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 320 AM CST FRI NOV 21 2014
FOR SAT NIGHT...THERE COULD BE SOME MIXED PRECIP...MAINLY FREEZING
RAIN PERHAPS ACCORDING TO TOP DOWN METHOD IN THE DEVILS LAKE
BASIN. MOST AREAS SHOULD REMAIN DRY...BUT MODELS ARE HINTING AT
THE POTENTIAL FOR LOWER LEVEL MOISTURE AND WILL HAVE TO MONITOR
FOR FREEZING DRIZZLE POTENTIAL AS WELL.
ON SUNDAY...SFC LOW PRESSURE WILL MOVE ALONG THE INTERNATIONAL
BORDER AREA. DEEPER LAYERED SATURATION AND MID LEVEL LIFT WILL
MOVE INTO THE NORTH AND WEST FIRST...THEN SPREAD EAST THROUGH THE
DAY. THERE WILL BE THE CHANCE FOR SOME LIGHT SNOW...MAINLY IN THE
NORTHERN AREAS LATER IN THE DAY. NORTHERLY WINDS WILL INCREASE
BEHIND A COLD FRONT...AND IF THERE IS ANY SNOW IN THE FAR NW LATER
SUNDAY THEN SOME BLOWING SNOW IS POSSIBLE.
FOR SUNDAY NIGHT...DEEPER MOISTURE WILL OVERSPREAD THE REGION NEAR
A TROWAL. THERE SHOULD BE SOME LIGHT SNOW FOR MOST AREAS...WITH
PERHAPS AN INCH FOR MOST AREAS POSSIBLE. NORTHERLY WINDS WILL
INCREASE AND THERE WILL BE 40KT TO MIX IN THE VALLEY AFTER 06Z
MONDAY. THIS SHOULD YIELD AT LEAST PATCHY BLOWING SNOW FOR AREAS
THAT GET AN INCH OF SNOW...AND THERE COULD BE MORE VISIBILITY
ISSUES WHERE A CURRENT SNOW PACK OF 2 INCHES OR MORE IS IN PLACE.
THERE COULD BE SOME MELTING/CRUSTING OF SNOW PACK THOUGH THIS
WEEKEND...SO EXPECT VSBY ISSUES TO BE HIGHLY DEPENDENT ON JUST
HOW MUCH SNOW FALLS. THE GFS GIVES THE NORTHERN AREAS ABOUT 2
INCHES...WITH AN INCH OR SO NEAR GFK...AND LIGHTER AMOUNTS TO THE
SOUTH. IF THIS WOULD VERIFY...THEN THE MONDAY MORNING COMMUTE
WOULD BE IMPACTED WITH BLOWING SNOW AND LOW VSBYS IN OPEN COUNTRY
...SO WILL START TO MENTION BLOWING SNOW IN THE VALLEY AND HIGHLIGHT
IN THE HWO.
MONDAY THROUGH THURSDAY...EXTENDED BEGINS WITH MODELS IN DECENT
AGREEMENT THAT DEPARTING LOW MAKES MONDAY A WINDY DAY. TROWAL SETUP
SUGGESTS WRAP AROUND SNOWFALL WILL BE OF A SUFFICIENT AMOUNT TO BE
BLOWN AROUND BY STRONG WINDS. HAVE USED THE MOS WINDS FOR MONDAY
INTO MONDAY EVENING AS LOCAL TOOLS INDICATE A FAVORABLE PATTERN FOR
SURFACE WIND GUSTS TO 35 KTS. HAVE KEPT PREVIOUS FCST OF BS WHERE
SNOWFALL OCCURS. TEMPERATURES WILL PROBABLY BE STEADY OF FALL SLOWLY
IN CAA.
AS SNOW ENDS LATE MONDAY FAST NORTHWEST FLOW DRIVES ANOTHER WAVE
ACROSS THE CWFA TUESDAY INTO WEDNESDAY. MODELS IN FAIR AGREEMENT
THAT ALBERTA CLIPPER SYSTEM/UPPER WAVE MOVES ALONG A TRACK FAVORABLE
FOR MEASURABLE SNOWFALL.
FOR WEDNESDAY AND THURSDAY SURFACE HIGH BUILDS INTO THE NORTHERN
PLAINS RETURNING THE REGION TO A TEMPERATURE REGIME MORE LIKE MID
JANUARY THAN LATE NOVEMBER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1226 PM CST FRI NOV 21 2014
VFR CONDITIONS EXPECTED THRU 06Z WITH SOME PATCHY CIRRUS AND MID
CLOUD. SOUTH TO SOUTHWEST WIND OF 15 TO 25 KTS WITH A FEW HIGHER
GUSTS WILL OCCUR TODAY DIMINISHING SOME THIS EVENING. A WEAK COOL
FRONT WILL DROP SOUTH TO NEAR THE INTERNATIONAL BORDER OR A TAD
SOUTH OF IT BY 12Z SAT. RAP AND SHORT RANGE MODELS INDICATE SOME
MVFR CIGS PSBL NEAR THIS BOUNDARY OVER FAR NORTHEASTERN ND AND FAR
NORTHERN MN MOSTLY 12-18Z SATURDAY PERIOD. UNCERTAIN HOW FAR SOUTH
MVFR CIGS WILL GET HOWEVER. ANOTHER CONCERN IS LOWER CLOUDS IN
EASTERN HALF OF KANSAS. 859-925 MB WINDS WOULD SUGGEST THE TARGET
AREA FOR THOSE WILL BE IOWA....SOUTHEASTERN
MINNESOTA/WISCONSIN/ILLINOIS LATER TONIGHT INTO SATURDAY.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...TG
SHORT TERM...DK
LONG TERM...EWENS/DK
AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
956 PM EST SAT NOV 22 2014
.SYNOPSIS...
MAINLY CLOUDY SKIES WITH EMBEDDED SHOWERS FROM TIME TO TIME
ARE IN STORE FOR TONIGHT IN A RELATIVELY MOIST AND MILD SOUTHWESTERLY
FLOW. FOR SUNDAY AND SUNDAY NIGHT...DEEPENING LOW PRESSURE WILL
PULL A LARGE SWATH OF MOISTURE NORTHWARD...RESULTING IN WIDESPREAD
RAIN SHOWERS. MORE SHOWERS AND WINDY CONDITIONS WILL ACCOMPANY A
COLD FRONT ON MONDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
LATEST 00Z NAM-WRF...HRRR AND RAP INDICATE THAT AREA OF SHOWERS
OVER EAST CENTRAL ILLINOIS/WEST CENTRAL INDIANA WILL EXPAND AND
PIVOT NORTHEAST OVERNIGHT. THIS PCPN IS IN RESPONSE TO AN
EMBEDDED S/WV AND LOW LEVEL JET WITHIN A MOIST SOUTHWEST PLUME.
HAVE INCREASED POPS TO LIKELY FOR NORTHWESTERN ZONES AFTER
MIDNIGHT WITH POPS RAPIDLY DECREASING AS ONE GOES TOWARD THE OHIO
RIVER. SKIES WILL BE MAINLY CLOUDY FOR MOST LOCATIONS.
TEMPERATURES HAVE ALREADY FALLEN OFF CONSIDERABLY IN SOUTH CENTRAL
OHIO AND NORTHEAST KENTUCKY WHILE IT REMAINS MILD ELSEWHERE. WE
SHOULD SEE A GRADUAL DECREASE IN TEMPERATURES NORTHERN/WESTERN
ZONES OVERNIGHT WITH SOME RECOVERY EXPECTED SOUTHEAST AS CLOUDS
THICKEN AND PERHAPS A LITTLE WIND PICKS UP.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
AN ELONGATED AREA OF LOW PRESSURE WILL BE STRENGTHENING TO THE
WEST ON SUNDAY. MOISTURE ARRIVING ON AN INCREASING SOUTHERLY FLOW
WILL OVERSPREAD THE AREA...BRINGING RAIN SHOWERS TO ALL LOCATIONS
BY SUNDAY EVENING. THE SHOWERS ARE LIKELY TO CONTINUE SUNDAY NIGHT
AND MONDAY AS THE LOW MOVES NORTH AND DEEPENS OVER THE GREAT
LAKES...WHILE DRAGGING A STRONG COLD FRONT FROM THE WEST. LOOKS
LIKE THE AREA COULD RECEIVE AROUND AN INCH OF RAINFALL ON AVERAGE
BY MONDAY AFTERNOON. SHOWERS SHOULD END MONDAY NIGHT AS THE SYSTEM
LIFTS NORTHEAST.
ANOTHER PROBLEM WILL INVOLVE STRONG WINDS...ESPECIALLY ON MONDAY IN
THE VICINITY OF THE COLD FRONT. CURRENT INDICATIONS ARE THAT
NUMEROUS GUSTS OF 35 TO 45 MPH ARE PROBABLE. IF CONDITIONS ARE
AS SUGGESTED BY THE WINDIER MAV GUIDANCE...THEN A WIND ADVISORY
MAY BE NEEDED.
WARM ADVECTION WILL BRING HIGHS INTO THE MID 50S TO AROUND 60 ON
SUNDAY. HIGHS ON MONDAY SHOULD STAY IN THE 50S WITH COLDER AIR
FILTERING IN FROM THE WEST MONDAY AFTERNOON.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
BELOW NORMAL HEIGHTS WITH MEAN TROF OVER THE NATIONS MID SECTION TO
START THE LONG TERM FORECAST PERIOD. PRECIPITATION SHOULD STAY NORTH
OF ILN/S FA WITH SFC HIGH PRESSURE BUILDING INTO THE OHIO VALLEY
TUESDAY. TEMPERATURES WILL BE CLOSE TO 15 DEGREES BELOW NORMAL...
WITH HIGHS FROM THE LOWER 30S NORTH TO THE LOWER 40S SE.
ILN/S FA BETWEEN SYSTEMS ON WED AS SFC HIGH PRESSURE SHIFTS EAST ON
WED. BELOW NORMAL TEMPERATURES TO CONTINUE WITH HIGHS RANGING FROM
THE MID 30S NORTH TO THE LOWER 40S SOUTH.
CLIPPER TYPE SYSTEM TO DROP SE THRU THE GREAT LAKES WITH ASSOCIATED
COLD FRONT SWEEPING EAST THRU ILN/S FA EARLY THURSDAY. WILL BRING
SNOW IN WED NIGHT AND CONTINUE INTO THURSDAY. SOME PCPN MIX WITH BE
POSSIBLE ACRS THE SOUTH. HAVE LEANED TOWARD THE COLDER ECMWF SOLN
AND HAVE LIMITED ANY MIX TO THE SE. BEST POPS ACRS THE NORTH CLOSER
TO THE SFC WAVE. EARLY HIGHS ON THURSDAY TO RANGE FROM THE LOWER 30S
NW TO NEAR 40 SE.
IN NORTHWEST FLOW AND CAA SOME LINGERING SNOW SHOWERS PSBL THURSDAY
NIGHT. SFC HIGH PRESSURE TO BUILD IN ON FRIDAY PROVIDING CONTD COLD
TEMPERATURES AND DRY CONDITIONS. HIGHS ON FRIDAY TO RANGE FROM THE
LOWER 30S NW TO THE UPR 30S SE.
SFC HIGH PRESSURE TO BUILD ACRS THE REGION AS MID LEVEL FLOW BACKS
WESTERLY. A QUICK RETURN LOW LEVEL FLOW TO DEVELOP ON THE BACK SIDE
OF THE RETREATING HIGH. WILL HOLD OFF ON ANY WAA PCPN UNTIL SATURDAY
NIGHT.
&&
.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
AN EMBEDDED DISTURBANCE WITHIN A MOIST SOUTHWEST FLOW ALOFT...ALONG
WITH A LOW LEVEL JET...WILL TEAM UP TO BRING SOME MORE SHOWERS TO
THE TAF SITES OVERNIGHT WITH THE HIGHEST PROBABILITY OCCURRING AT
THE NORTHERN TAF SITES OF KDAY...KCMH...AND KLCK. CEILINGS SHOULD
REMAIN VFR WITH PERHAPS SOME BRIEF MVFR VISIBILITIES WITH SHOWERS.
ON SUNDAY...A DECENT UPPER LEVEL DISTURBANCE WILL ROTATE NORTHWARD
FROM THE LOWER GULF COASTS STATES TO THE OHIO VALLEY BY SUNDAY
NIGHT. THIS FEATURE WILL EVENTUALLY BECOME ABSORBED BY STRONGER
UPPER LEVEL ENERGY TO THE WEST BY MONDAY MORNING. INCREASING MOIST
ASCENT WITH A SUBSTANTIAL LOW LEVEL JET ALONG WITH INCREASING
DIVERGENCE ALOFT WILL SPREAD WIDESPREAD SHOWERS INTO THE AREA FROM
SOUTH TO NORTH BETWEEN 18Z AND 00Z. MVFR CONDITIONS CAN BE
EXPECTED AT THE ONSET...FOLLOWED BY DETERIORATING CEILINGS AND
VISIBILITIES INTO THE IFR CATEGORY DUE TO LOCALLY MODERATE/HEAVY
SHOWERS. WINDS WILL INCREASE AS WELL AND WILL BACK WITH TIME FROM
A SOUTHERLY DIRECTION TO A SOUTHEAST DIRECTION AS LOW PRESSURE
DEEPENS OVER THE MID MISSISSIPPI VALLEY AND A WARM FRONT APPROACHES
FROM THE SOUTH. SHOWERY WEATHER...BUT NOT AS HEAVY...WILL CONTINUE
LATER INTO SUNDAY NIGHT AHEAD OF A STRONG COLD FRONT. CEILINGS
SHOULD REMAIN IN THE IFR CATEGORY.
OUTLOOK...MVFR/IFR CEILINGS AND MVFR VISIBILITIES TO CONTINUE INTO
MONDAY AS A STRONG COLD FRONT MOVES THROUGH THE REGION. GUSTY
SOUTHWEST WINDS AROUND 35 KNOTS LIKELY MONDAY INTO MONDAY NIGHT.
MVFR CEILINGS POSSIBLE MONDAY NIGHT INTO TUESDAY. MVFR/IFR
CONDITIONS POSSIBLE THURSDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...CONIGLIO
NEAR TERM...HICKMAN
SHORT TERM...CONIGLIO/HICKMAN
LONG TERM...AR
AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
954 PM EST SAT NOV 22 2014
.SYNOPSIS...
MAINLY CLOUDY SKIES WITH EMBEDDED SHOWERS FROM TIME TO TIME
ARE IN STORE FOR TONIGHT IN A RELATIVELY MOIST AND MILD SOUTHWESTERLY
FLOW. FOR SUNDAY AND SUNDAY NIGHT...DEEPENING LOW PRESSURE WILL
PULL A LARGE SWATH OF MOISTURE NORTHWARD...RESULTING IN WIDESPREAD
RAIN SHOWERS. MORE SHOWERS AND WINDY CONDITIONS WILL ACCOMPANY A
COLD FRONT ON MONDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
LATEST 00Z NAM-WRF...HRRR AND RAP INDICATE THAT AREA OF SHOWERS
OVER EAST CENTRAL ILLINOIS/WEST CENTRAL INDIANA WILL EXPAND AND
PIVOT NORTHEAST OVERNIGHT. THIS PCPN IS IN RESPONSE TO AN
EMBEDDED S/WV AND LOW LEVEL JET WITHIN A MOIST SOUTHWEST PLUME.
HAVE INCREASED POPS TO LIKELY FOR NORTHWESTERN ZONES AFTER
MIDNIGHT WITH POPS RAPIDLY DECREASE AS ONE GOES TOWARD THE OHIO
RIVER. SKIES WILL BE MAINLY CLOUDY FOR MOST LOCATIONS.
TEMPERATURES HAVE ALREADY FALLEN OFF CONSIDERABLY IN SOUTH CENTRAL
OHIO AND NORTHEAST KENTUCKY WHILE IT REMAINS MILD ELSEWHERE. WE
SHOULD SEE A GRADUAL DECREASE NORTHERN/WESTERN ZONES OVERNIGHT
WITH SOME RECOVER EXPECTED SOUTHEAST AS CLOUDS THICKEN AN PERHAPS
A LITTLE WIND PICKS UP.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
AN ELONGATED AREA OF LOW PRESSURE WILL BE STRENGTHENING TO THE
WEST ON SUNDAY. MOISTURE ARRIVING ON AN INCREASING SOUTHERLY FLOW
WILL OVERSPREAD THE AREA...BRINGING RAIN SHOWERS TO ALL LOCATIONS
BY SUNDAY EVENING. THE SHOWERS ARE LIKELY TO CONTINUE SUNDAY NIGHT
AND MONDAY AS THE LOW MOVES NORTH AND DEEPENS OVER THE GREAT
LAKES...WHILE DRAGGING A STRONG COLD FRONT FROM THE WEST. LOOKS
LIKE THE AREA COULD RECEIVE AROUND AN INCH OF RAINFALL ON AVERAGE
BY MONDAY AFTERNOON. SHOWERS SHOULD END MONDAY NIGHT AS THE SYSTEM
LIFTS NORTHEAST.
ANOTHER PROBLEM WILL INVOLVE STRONG WINDS...ESPECIALLY ON MONDAY IN
THE VICINITY OF THE COLD FRONT. CURRENT INDICATIONS ARE THAT
NUMEROUS GUSTS OF 35 TO 45 MPH ARE PROBABLE. IF CONDITIONS ARE
AS SUGGESTED BY THE WINDIER MAV GUIDANCE...THEN A WIND ADVISORY
MAY BE NEEDED.
WARM ADVECTION WILL BRING HIGHS INTO THE MID 50S TO AROUND 60 ON
SUNDAY. HIGHS ON MONDAY SHOULD STAY IN THE 50S WITH COLDER AIR
FILTERING IN FROM THE WEST MONDAY AFTERNOON.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
BELOW NORMAL HEIGHTS WITH MEAN TROF OVER THE NATIONS MID SECTION TO
START THE LONG TERM FORECAST PERIOD. PRECIPITATION SHOULD STAY NORTH
OF ILN/S FA WITH SFC HIGH PRESSURE BUILDING INTO THE OHIO VALLEY
TUESDAY. TEMPERATURES WILL BE CLOSE TO 15 DEGREES BELOW NORMAL...
WITH HIGHS FROM THE LOWER 30S NORTH TO THE LOWER 40S SE.
ILN/S FA BETWEEN SYSTEMS ON WED AS SFC HIGH PRESSURE SHIFTS EAST ON
WED. BELOW NORMAL TEMPERATURES TO CONTINUE WITH HIGHS RANGING FROM
THE MID 30S NORTH TO THE LOWER 40S SOUTH.
CLIPPER TYPE SYSTEM TO DROP SE THRU THE GREAT LAKES WITH ASSOCIATED
COLD FRONT SWEEPING EAST THRU ILN/S FA EARLY THURSDAY. WILL BRING
SNOW IN WED NIGHT AND CONTINUE INTO THURSDAY. SOME PCPN MIX WITH BE
POSSIBLE ACRS THE SOUTH. HAVE LEANED TOWARD THE COLDER ECMWF SOLN
AND HAVE LIMITED ANY MIX TO THE SE. BEST POPS ACRS THE NORTH CLOSER
TO THE SFC WAVE. EARLY HIGHS ON THURSDAY TO RANGE FROM THE LOWER 30S
NW TO NEAR 40 SE.
IN NORTHWEST FLOW AND CAA SOME LINGERING SNOW SHOWERS PSBL THURSDAY
NIGHT. SFC HIGH PRESSURE TO BUILD IN ON FRIDAY PROVIDING CONTD COLD
TEMPERATURES AND DRY CONDITIONS. HIGHS ON FRIDAY TO RANGE FROM THE
LOWER 30S NW TO THE UPR 30S SE.
SFC HIGH PRESSURE TO BUILD ACRS THE REGION AS MID LEVEL FLOW BACKS
WESTERLY. A QUICK RETURN LOW LEVEL FLOW TO DEVELOP ON THE BACK SIDE
OF THE RETREATING HIGH. WILL HOLD OFF ON ANY WAA PCPN UNTIL SATURDAY
NIGHT.
&&
.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
AN EMBEDDED DISTURBANCE WITHIN A MOIST SOUTHWEST FLOW ALOFT...ALONG
WITH A LOW LEVEL JET...WILL TEAM UP TO BRING SOME MORE SHOWERS TO
THE TAF SITES OVERNIGHT WITH THE HIGHEST PROBABILITY OCCURRING AT
THE NORTHERN TAF SITES OF KDAY...KCMH...AND KLCK. CEILINGS SHOULD
REMAIN VFR WITH PERHAPS SOME BRIEF MVFR VISIBILITIES WITH SHOWERS.
ON SUNDAY...A DECENT UPPER LEVEL DISTURBANCE WILL ROTATE NORTHWARD
FROM THE LOWER GULF COASTS STATES TO THE OHIO VALLEY BY SUNDAY
NIGHT. THIS FEATURE WILL EVENTUALLY BECOME ABSORBED BY STRONGER
UPPER LEVEL ENERGY TO THE WEST BY MONDAY MORNING. INCREASING MOIST
ASCENT WITH A SUBSTANTIAL LOW LEVEL JET ALONG WITH INCREASING
DIVERGENCE ALOFT WILL SPREAD WIDESPREAD SHOWERS INTO THE AREA FROM
SOUTH TO NORTH BETWEEN 18Z AND 00Z. MVFR CONDITIONS CAN BE
EXPECTED AT THE ONSET...FOLLOWED BY DETERIORATING CEILINGS AND
VISIBILITIES INTO THE IFR CATEGORY DUE TO LOCALLY MODERATE/HEAVY
SHOWERS. WINDS WILL INCREASE AS WELL AND WILL BACK WITH TIME FROM
A SOUTHERLY DIRECTION TO A SOUTHEAST DIRECTION AS LOW PRESSURE
DEEPENS OVER THE MID MISSISSIPPI VALLEY AND A WARM FRONT APPROACHES
FROM THE SOUTH. SHOWERY WEATHER...BUT NOT AS HEAVY...WILL CONTINUE
LATER INTO SUNDAY NIGHT AHEAD OF A STRONG COLD FRONT. CEILINGS
SHOULD REMAIN IN THE IFR CATEGORY.
OUTLOOK...MVFR/IFR CEILINGS AND MVFR VISIBILITIES TO CONTINUE INTO
MONDAY AS A STRONG COLD FRONT MOVES THROUGH THE REGION. GUSTY
SOUTHWEST WINDS AROUND 35 KNOTS LIKELY MONDAY INTO MONDAY NIGHT.
MVFR CEILINGS POSSIBLE MONDAY NIGHT INTO TUESDAY. MVFR/IFR
CONDITIONS POSSIBLE THURSDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...CONIGLIO
NEAR TERM...HICKMAN
SHORT TERM...CONIGLIO/HICKMAN
LONG TERM...AR
AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
657 PM EST SAT NOV 22 2014
.SYNOPSIS...
A WARM FRONT WILL CONTINUE TO MOVE NORTH OF THE AREA TONIGHT.
A RELATIVELY WARM AND MOIST SOUTHERLY FLOW OF AIR WILL CONTINUE
OVER THE AREA INTO MONDAY. DEEPENING LOW PRESSURE WILL TRACK
ACROSS THE GREAT LAKES SUNDAY NIGHT AND MONDAY SENDING A STRONG
COLD FRONT ACROSS THE AREA ON MONDAY. A TROUGH OF LOW PRESSURE
WILL LINGER ACROSS THE AREA THROUGH THE MIDDLE OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
CONTINUING TO SEE A FEW AREAS OF LIGHT SHOWERS DEVELOP WITHIN THE
MOIST SOUTHWEST FLOW. RAISED POPS TO LIKELY ALONG THE NORTHEAST
SHORELINE AND UP TOWARDS ERIE PA WHERE SHOWERS HAVE FILLED IN.
OTHERWISE...WE CONTINUE TO WATCH ENERGY AND DEEPER MOISTURE
STREAMING OUT OF THE SOUTHERN PLAINS ON WATER VAPOR IMAGERY. 18Z
NAM HAS TRENDED UPWARD WITH QPF ACROSS NW OHIO LATE TONIGHT AND IS
NOW MORE IN LINE WITH THE GFS. HRRR ALSO PRETTY AGGRESSIVE WITH
THIS AREA OF SHOWERS ARRIVING AROUND 08Z SO RAISED POPS IN NW OHIO
LATE TONIGHT. TEMPERATURES IN NW OHIO ARE IN THE UPPER 40S AND
MADE SOME ADJUSTMENTS TO HOURLY TEMPERATURES AND
DEWPOINTS...MAINLY TRENDING HIGHER THROUGH THE EVENING.
PREVIOUS DISCUSSION...A LEAD SHORT WAVE STREAKING OUT OF THE
LOWER MISSISSIPPI VALLEY WILL BRING AN INCREASING CHANCE OF
SHOWERS ACROSS THE LOWER OHIO VALLEY AND MIDWEST LATER TONIGHT
WHICH WILL LIKELY CLIP NORTHWEST OHIO LATER TONIGHT. ELSEWHERE
JUST A FEW SPRINKLES OR BRIEF SHOWERS TONIGHT AS WARM ADVECTION
AND A NICE LOW LEVEL JET CONTINUE.
THE AIR MASS IS SO WARM TO OUR SOUTH THAT I DOUBT WE WILL SEE MUCH
TEMPERATURE DROP TONIGHT. THE ONLY CONCERN FOR THE LOW TEMPERATURE
FORECAST IS THAT LOWER DEW POINT AIR IS STREAMING NORTHEAST AND
SHOULD AFFECT MUCH OF THE FORECAST AREA TONIGHT...ESPECIALLY
NORTHEASTERN OHIO AND NORTHWEST PENNSYLVANIA. DEW POINTS WILL LIKELY
DROP A FEW DEGREES IN THIS AREA. A FEW BREAKS IN THE CLOUDS MAY
TRACK ACROSS NE OH/NW PA TONIGHT. NIGHTS ARE LONG AND GIVEN ANY
CHANCE WE WILL GET SOME RADIATIONAL COOLING ESPECIALLY OVER AREAS
WHERE THERE IS SNOW ON THE GROUND. LOWS IN THE MID 30S IN THESE
AREAS WITH 40S ELSEWHERE.
SOUTH WINDS WILL STAY UP TONIGHT...GENERALLY 10-15 MPH WITH GUSTS
ESPECIALLY IN THE SOUTH DOWN SLOPE AREAS...IN PARTICULAR THE EAST
LAKESHORE EAST OF CLEVELAND THROUGH ERIE COUNTY PA WHERE GUSTS OF
30-35 STILL LIKELY.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
IN BETWEEN SYSTEMS FOR A WHILE SUNDAY. A FEW LEFTOVER SHOWERS SHOULD
BE EXITING ON SUNDAY MORNING. THE MAIN SHORT WAVE WILL LIFT OUT
SUNDAY AND SUNDAY NIGHT. RAIN SHOULD SPREAD NORTHEAST ACROSS THE
FORECAST AREA SUNDAY MID TO LATE AFTERNOON...PROBABLY SPREADING
NORTH TO ABOUT THE TURNPIKE BY DARK. THE RAIN WILL MOVE ACROSS THE
ENTIRE FORECAST AREA SUNDAY NIGHT. WENT A FEW DEGREES ABOVE
GUIDANCE BASED ON UPSTREAM TEMPS WITH HIGHS WELL IN THE 50S.
THE COLD FRONT WILL CROSS THE FORECAST AREA ON MONDAY. NOT SURE
HOW MUCH ADDITIONAL SHOWERS WILL OCCUR WITH THE FRONT...WHETHER IT
WILL BE A LINE OF SHOWERS OR SCATTERED SHOWERS. SOME CONCERN FOR
WIND ON MONDAY. THE SYNOPTIC WIND WILL PICK UP WITH THE FRONTAL
PASSAGE AND ONSET OF COLD ADVECTION. THERE COULD BE CONVECTIVE
WINDS IF WE CAN GET A LINE OF SHOWERS TO DEVELOP WITH THE FRONTAL
PASSAGE.
TEMPERATURES SHOULD REMAIN WARM ON MONDAY...IN THE 50S UNTIL THE
FRONT GOES THROUGH...THEN TEMPS SHOULD START TO DROP OFF. THE AIR
MASS BEHIND THE FRONT IS SEASONABLY COLD. LOWS MONDAY NIGHT NEAR
NORMAL.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
MODELS CONTINUE TO PUSH COASTAL LOW ALONG THE EAST COAST WEDNESDAY
WITH A RIDGE OVER FORECAST AREA. MODELS BEGIN TO DIVERGE WEDNESDAY
NIGHT. CLIPPER SYSTEM MOVES ACROSS CENTRAL LAKES DRAGGING ANOTHER
COLD FRONT ACROSS THE AREA AND KICKING OFF A QUICK SHOT OF SNOW.
ECMWF MOVES THE SNOW INTO THE AREA WEDNESDAY NIGHT WHILE THE GFS
HOLDS OFF UNTIL THANKSGIVING DAY. PREVIOUS FORECAST TRENDED TOWARD
THE GFS SO WITH SO WENT CHANCE POPS WEDNESDAY NIGHT WITH LIKELY POPS
ON THANKSGIVING. EITHER WAY IT LOOKS LIKE A QUICK SHOT OF SNOW WITH
HIGH PRESSURE BUILDING IN QUICKLY BEHIND.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
MAINLY VFR CONDITIONS WITH SCATTERED SHOWERS IN THE WARM SECTOR
FOR EARLY TONIGHT. SOME OF THE SHOWERS WILL HAVE MVFR CONDITIONS.
ALL MODELS INDICATE ANOTHER SURGE OF SHOWERS LATE TONIGHT. THIS
SEEMS REASONABLE BASED ON THE CURRENT RADAR WITH SOME SHOWERS OVER
SOUTHEAST MISSOURI. CONDITIONS WILL PROBABLY BE MVFR IN THOSE
SHOWERS. A DRY SLOT FOR LATE MORNING INTO THE AFTERNOON WITH SOME
VFR OR BARELY MVFR CEILINGS AND THEN MORE SHOWERS MOVING INTO NW
OHIO LATE IN THE AFTERNOON...SPREADING EAST IN THE EVENING.
.OUTLOOK...NON VFR AT TIMES SUNDAY NIGHT THROUGH TUESDAY AND THEN
AGAIN WEDNESDAY NIGHT INTO THURSDAY. SURFACE WINDS WILL BE STRONG
ESPECIALLY MONDAY AFTERNOON AND EVENING AROUND THE FRONTAL PASSAGE.
&&
.MARINE...
HAVE DROPPED THE SMALL CRAFT ADVISORY ON THE WEST END OF THE LAKE AS
THE WINDS HAVE DIMINISHED TO 10 TO 20 KNOTS. SMALL CRAFT ADVISORY
CONDITIONS WILL CONTINUE INTO THE OVERNIGHT ON THE EAST HALF OF THE
LAKE. MODELS CONTINUE TO MOVE STRONG FRONT ACROSS THE LAKE ON
MONDAY. THERE REMAINS A POTENTIAL FOR GALE FORCE WINDS MONDAY INTO
MONDAY NIGHT AS A DEEPENING LOW TRACKS ACROSS THE CENTRAL GREAT
LAKES. GFS IS DEEPER WITH LOW AND THUS ALSO HAS THE HIGHER WINDS.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EST SUNDAY FOR LEZ146>149.
&&
$$
SYNOPSIS...KOSARIK
NEAR TERM...KOSARIK
SHORT TERM...KOSARIK
LONG TERM...DJB
AVIATION...KIELTYKA
MARINE...DJB
AREA FORECAST DISCUSSION
NWS PORTLAND OR
942 AM PST FRI NOV 21 2014
.SYNOPSIS...MORE TYPICAL FALL WEATHER IN STORE FOR SOUTHWEST
WASHINGTON AND NORTHWEST OREGON TODAY. A FAIRLY STRONG AND MOIST
FRONTAL SYSTEM WILL BRING GUSTY COASTAL WINDS AND HEAVY RAIN TO THE
REGION TODAY AND TONIGHT. COOLER AIR BEHIND THIS SYSTEM WILL CAUSE
THE SNOW LEVELS TO LOWER BELOW THE CASCADE PASSES EARLY SATURDAY
WHILE STRONG ONSHORE FLOW CONTINUES THROUGH THE WEEKEND. AS A RESULT
SNOW MAY BECOME HEAVY AT TIMES ALL THE WAY DOWN TO PASS LEVELS THIS
WEEKEND. ANOTHER SYSTEM IS LIKELY TO AFFECT THE REGION EARLY NEXT
WEEK...THEN PERHAPS SOME DRIER WEATHER BY MIDWEEK.
&&
.SHORT TERM...A FAIRLY STRONG AND MOIST FRONTAL SYSTEM IS RAPIDLY
APPROACHING THE NW COAST TODAY...RIDING A ROBUST 160+ KT UPPER LEVEL
JET. A PRECIPITATION SHIELD ASSOCIATED WITH ISENTROPIC LIFT AHEAD OF
THE LEADING WARM FRONT IS MOVING ONSHORE THIS MORNING. THE STEADIER
PRECIPITATION IS MAINLY CONFINED TO THE COAST SO FAR...BUT WILL
PROCEED INLAND LATER THIS MORNING AND THIS AFTERNOON. THE LATEST
SURFACE OBSERVATIONS ARE STILL SHOWING SOME TEMPS AROUND FREEZING IN
THE CENTRAL COLUMBIA RIVER GORGE AND UPPER HOOD RIVER VALLEY...SO
THERE MAY BE SOME PATCHY FREEZING RAIN DURING THE ONSET OF PRECIP
THIS MORNING. HOWEVER...EXPECT TEMPS TO RISE ABOVE FREEZING OVER THE
NEXT FEW HOURS...EFFECTIVELY ENDING ANY ICING CONCERNS.
SOUTHERLY WINDS SHOULD BEGIN TO PICK UP ALONG THE COAST AROUND
MIDDAY. BASED ON THE LATEST SHORT TERM RAP AND HRRR MODEL
RUNS...DECIDED TO EXPAND THE EXISTING HIGH WIND WARNING FOR THE NORTH
AND CENTRAL OREGON COAST TO INCLUDE THE SOUTH WASHINGTON COAST AS
WELL. IT APPEARS THAT THE SURFACE LOW MIGHT BE TRACKING A BIT FURTHER
NORTH THAN PREVIOUSLY ANTICIPATED...WHICH MAY OPEN THE DOOR FOR AREAS
LIKE CAPE DISAPPOINTMENT TO PICK UP A FEW HIGH WIND CRITERIA GUSTS.
OVERALL...IT STILL LOOKS LIKE A FAIRLY MARGINAL WIND EVENT. SOME
BEACH AND EXPOSED HEADLAND LOCATIONS MAY SEE A FEW GUSTS AROUND 60 TO
65 MPH...BUT THE COASTAL COMMUNITIES WILL LIKELY SEE WINDS TOPPING
OUT AROUND 50 TO 55 MPH. THE COLD FRONT IS EXPECTED TO MOVE ONSHORE
AROUND 4 TO 6 PM...AFTER WHICH THE COASTAL WINDS SHOULD DROP OFF
RAPIDLY. THE INTERIOR LOWLANDS MAY ALSO EXPERIENCE A BRIEF PERIOD OF
GUSTY WINDS IN THE LATE AFTERNOON/EARLY EVENING AS THE COLD FRONT
MOVES THROUGH.
A BATCH OF HEAVY RAIN WILL PUSH INLAND DURING THE LATE AFTERNOON AND
EVENING...WITH 1.5 TO 2 INCHES OF RAIN LIKELY FOR THE
COAST...COAST RANGE AND CASCADES OVER ABOUT A 12 HR PERIOD ENDING
TONIGHT. THE INTERIOR LOWLANDS WILL BE CLOSER TO AN INCH. IT DOES NOT
APPEAR THAT RAINFALL TOTALS WILL BE ENOUGH TO CAUSE ANY FLOODING
CONCERNS.
SNOW LEVELS WILL INCREASE ABOVE ALL BUT THE HIGHEST PEAKS IN
THE AREA TODAY WITH THE WARM FRONT. SNOW LEVELS WILL CRASH
TO AROUND 3000 TO 4000 FT SATURDAY MORNING. OROGRAPHICS BECOME
FAVORABLE IN THIS COLDER AIR MASS. 850 MB WINDS ARE WESTERLY 25 TO
45 KT SAT ALONG WITH ABUNDANT SHOWERS. SNOW WILL BE HEAVIER AT TIMES
AS IMPULSES MOVE THROUGH. IT APPEARS THE PERIOD OF HIGHER SNOWFALL
ACCUMULATION WILL BE SAT INTO EARLY SUN. THIS PERIOD MAY END UP
NEEDING A WINTER WEATHER ADVISORY. CURRENT SPECIAL WEATHER
STATEMENT COVERS THIS UNTIL THEN.
500 MB TEMPERATURES DROP TO AROUND -25 TO -30 C ON SATURDAY. LIFTED
INDEX LOWERS TO AROUND 0 TO -2. THERE IS ALSO A WEAK VORT MAX THAT
MOVES THROUGH DURING THE DAY TO ASSIST IN THE INSTABILITY. SO HAVE
ADDED A SLIGHT CHANCE OF THUNDERSTORMS OVER THE WATERS AND INLAND TO
THE COAST RANGE. THE INTERIOR LOWLAND MAY NEED TO BE ADDED AS
WELL...BUT THREAT APPEARS TOO LOW AT THIS TIME. PYLE/26
.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY. THE MORE WESTERLY OR
ZONAL FLOW THAT SETS UP OVER THE WEEKEND DURING THE LATTER PART OF
THE SHORT TERM PERIOD BEGINS TO BUCKLE A BIT IN THE EARLY PART OF
THE LONG TERM PERIOD WITH SOME FLAT RIDGING DEVELOPING OVER THE
NORTHEAST PACIFIC. HAVE DECIDED TO CONTINUE TO STICK MORE WITH A
DIRTY RIDGE SCENARIO OF THE ECMWF VS THE HIGHER AMPLITUDE RIDGING OF
THE OPERATIONAL GFS MODEL. CONFIDENCE DECREASES THROUGHOUT THE LONG
TERM PERIOD AS MODEL VARIABILITY INCREASES...THOUGH THE TREND IS
TOWARD DRIER DURING THE MIDDLE TO LATTER PARTS OF NEXT WEEK. TOLLESON
&&
.AVIATION...MIX OF VFR AND MVFR CIGS TO CONTINUE THIS MORNING AS
WARM FRONT LIFTS ACROSS THE AREA. WINDS WILL PICK UP FROM THE
SOUTH BEHIND THIS FRONT...LIFTING MOST THE AREA TO VFR CIGS. MAY
BE SOME SPEED SHEAR JUST ABOVE THE GROUND...AS SOUTHERLIES
INCREASE FROM 10 TO 30 OR 40 KTS BELOW FL030. EXPECT MIX OF VFR
AND MVFR TO PERSIST ACROSS THE AREA...THOUGH STRONG LOW-LEVEL
WINDS MAY KEEP CIGS MAINLY VFR. COLD FRONT MOVES THROUGH AROUND
06Z TO 09Z WHICH WILL ALLOW WINDS TO DIE DOWN THIS
EVENING...BRINGING CIGS BACK DOWN TO MVFR AND SOME IFR TONIGHT.
KPDX AND APPROACHES...VFR CONTINUES THROUGH THIS MORNING...THOUGH
HEAVIER SHOWERS MAY CAUSE OCCASIONAL MVFR CIGS. SOUTHERLIES
INCREASE FROM 10 KTS AT THE SURFACE TO 30 OR 40 KTS BELOW FL030
THIS AFTERNOON...BUT WILL DECREASE BEHIND COLD FRONT AROUND 06Z TO
09Z THIS EVENING.
-MCCOY
&&
.MARINE...GALE WARNING IN EFFECT THROUGH THIS EVENING. SOUTHERLY
WINDS CURRENTLY 20 TO 25 KTS GUSTING TO 35 CURRENTLY...AND WILL
CONTINUE TO RAMP UP THROUGH THIS AFTERNOON. EXPECTING SOLID GALES
WITH SOME STORM FORCE GUSTS POSSIBLE...MAINLY IN THE INNER WATERS
WITH A COASTAL JET. STRONGEST WINDS WILL OCCUR DURING THE
AFTERNOON HOURS...BEFORE DECREASING THIS EVENING BEHIND THE COLD
FRONT.
SEAS 10 TO 12 FT THIS MORNING WILL BUILD QUICKLY THIS AFTERNOON TO
NEAR 20 FT BY 4-6PM THIS EVENING. SEAS WILL SUBSIDE BEHIND THE
FRONT...DROPPING TO 12 TO 14 FT BY MIDNIGHT. SMALL CRAFT ADVISORY
SEAS ABOVE 10 FT LOOK TO PERSIST THROUGH THIS WEEKEND.
-MCCOY
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...HIGH WIND WARNING UNTIL 7 PM PST THIS EVENING FOR CENTRAL
OREGON COAST-NORTH OREGON COAST.
WA...HIGH WIND WARNING UNTIL 7 PM PST THIS EVENING FOR SOUTH
WASHINGTON COAST.
PZ...GALE WARNING UNTIL 10 PM PST THIS EVENING FOR COASTAL WATERS
FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 10 PM
PST THIS EVENING.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
940 PM CST SAT NOV 22 2014
.UPDATE...
ISSUED AT 940 PM CST SAT NOV 22 2014
STRATUS CONTINUES TO MOVE BACK INTO THE REGION TONIGHT. HRRR AND
RAP SEEM TO HAVE A GOOD HANDLE ON THIS...KEEPING MOST OF THE
STRATUS ALONG AND EAST OF INTERSTATE 29. SIGNAL FOR DENSE FOG IN
THE MODELS IS LESS THAN LAST NIGHT AND CURRENTLY NOT SEEING MUCH
OUT THERE. WILL KEEP FOG IN THE FORECAST...BUT PROBABILITY OF
WIDESPREAD DENSE FOG SEEMS TO BE DECREASING...ALTHOUGH WILL NEED
TO CONTINUE TO MONITOR.
OTHERWISE WATCHING SOME LIGHT PRECIPITATION THAT WILL TRY TO MOVE
ACROSS THE REGION TONIGHT INTO TOMORROW ASSOCIATED WITH A PRETTY
GOOD AREA OF MID LEVEL FRONTOGENESIS. WILL HAVE TO OVERCOME QUITE
A BIT OF DRY AIR IN THE LOW LEVELS...BUT STILL COULD SEE SOME
LIGHT PRECIPITATION WORK FROM WEST TO EAST INTO EARLY TOMORROW
AFTERNOON. DID GO AHEAD AND CHANGE PRECIPITATION TYPE TO ALL RAIN
THOUGH. EXPECT SURFACE TEMPERATURES TO REMAIN ABOVE FREEZING...AND
MODEL SOUNDINGS SUGGEST PLAIN RAIN IS THE MOST LIKELY PRECIPITATION
TYPE. SREF PROBABILITIES ALSO BACK THIS UP...SO FELT COMFORTABLE
REMOVING MENTION OF SNOW. CAN NOT COMPLETELY RULE OUT A FEW FLAKES
MIXED IN...BUT SHOULD MAINLY BE A CHILLY LIGHT RAIN IF ANYTHING.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 415 PM CST SAT NOV 22 2014
ANOTHER DIFFICULT FORECAST IN THE SHORT TERM AS LOW CLOUDS AND
STRATUS STRUGGLING TO ERODE ACROSS THE EASTERN HALF OF THE FORECAST
AREA. WHERE THE STRATUS HAS ERODED...TEMPERATURES HAVE RECOVERED
NICELY IN THE 40S AND 50S...BUT ACROSS THE EAST UNDER THE BLANKET OF
LOW CLOUDS...TEMPERATURES HAVE REMAINED STEADY IN THE 30S. EXPECT
THE EAST TO FILL BACK IN WITH LOW CLOUDS AND FOG TONIGHT...AND MAY
HAVE TO ISSUE A DENSE FOG ADVISORY TONIGHT FOR PORTIONS OF THE
FORECAST AREA. BEST CHANCES APPEAR TO BE ALONG AND EAST OF A LINE
FROM VERMILLION TO MARSHALL AND EAST. EXPECT VISIBILITIES TO
IMPROVE AS SURFACE TROUGH SHIFTS EAST AND WINDS BECOME NORTHWEST
DRYING OUT THE LOW LEVELS. WITH THE PASSAGE OF THE TROUGH...COULD
HAVE A SMALL AMOUNT OF PRECIPITATION WITH STRONG 700 MB
FRONTOGENESIS COINCIDING WITH WEAK DIV Q ALOFT. PRECIP TYPE COULD
BE A REAL CONCERN THROUGH THE MORNING HOURS WITH TEMPERATURES AT
THE SURFACE NEAR FREEZING. TOUGH CALL IN TERMS OF PRECIP
TYPE...FOR NOW...KEPT PRECIP TYPES CONFINED TO RAIN OR SNOW...BUT
COULD BE POTENTIAL FOR FREEZING RAIN WITH WARM DRY LAYER IN THE
LOWEST 2000 FEET OF THE ATMOSPHERE. EXPECT PRECIP TO BE ALL RAIN
AS IT SHIFTS FURTHER EAST INTO LOCATIONS WHERE TEMPERATURES REMAIN
ABOVE FREEZING. HIGH TEMPERATURES A TOUGH CALL ON SUNDAY...WITH
925 HPA TEMPS COOLING FROM NEAR 10C DOWN CLOSER TO 5C BY 0Z
MONDAY. FURTHER BACK TO THE NORTHWEST...925 HPA TEMPS HOVER IN THE
LOWER SINGLE DIGITS LEADING TO A RELATIVELY SMALL DIURNAL
FLUCTUATION UNDER A MOSTLY CLOUDY SKY.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 415 PM CST SAT NOV 22 2014
BY SUNDAY NIGHT...NORTHWEST WINDS INCREASE TO 20 TO 30 MPH WITH
HIGHER GUSTS TO 45 MPH. COLDER AIR BEGINS RUSHING BACK INTO THE
REGION...WITH TEMPERATURES DROPPING BACK BELOW FREEZING IN THE
EVENING AND REACHING THE TEENS AND LOWER 20S BY DAYBREAK MONDAY. AS
THE NORTHERN STREAM UPPER TROUGH DIGS INTO THE NORTHERN PLAINS AND
MERGES WITH THE SOUTHERN STREAM WAVE TO OUR EAST...SOME SCATTERED
LIGHT SNOWFALL WILL TRACK SOUTHEAST ACROSS THE FORECAST
AREA...HOWEVER THE BETTER FORCING REMAINS TO OUR EAST AND WITHOUT A
GREAT DEAL OF MOISTURE...ANY SNOWFALL WILL BE ON THE LIGHT SIDE.
COULD SEE AROUND A HALF INCH TO INCH IN SOUTHWEST MINNESOTA...
OTHERWISE A FEW TENTHS OR TRACE AT BEST. ADDITIONALLY...WITH THE
GUSTY WINDS...THE LIGHT SNOW WILL BLOW AROUND A BIT...BUT AMOUNTS
WILL BE TOO LIGHT FOR ANY BLOWING SNOW MENTION. ANY EXISTING SNOW
PACK SHOULD HAVE ENOUGH OF A CRUST TO NOT CAUSE ANY BLOWING SNOW
ISSUES EITHER.
WITH THE DEEP UPPER LEVEL TROUGH SLIDING ACROSS THE WESTERN GREAT
LAKES AND SHARP RIDGING ALONG THE WEST COAST...UPPER LEVEL NORTHWEST
FLOW SETTLES INTO THE AREA. WHILE NOT PARTICULARLY A COLD
AIRMASS...TEMPERATURES REMAIN BELOW NORMAL IN THE MID 20S TO MID 30S
ON TUESDAY AND WEDNESDAY. MODELS TRACK A CLIPPER WAVE ALONG THE
UPPER FLOW...ALTHOUGH THE TIMING...TRACK AND STRENGTH OF THIS FAST
MOVING WAVE REMAINS IN POOR AGREEMENT. THE GFS IS QUITE A BIT FASTER
THAN THE OTHER MODELS...FOLLOWED BY THE ECMWF THEN THE NAM. BUT IT
SEEMS THE GENERAL CONSENSUS IS FOR THE BEST CHANCE OF LIGHT SNOW IN
OUR NORTHEASTERN COUNTIES ON TUESDAY NIGHT.
UNCERTAINTY FURTHER INCREASES WEDNESDAY AND WEDNESDAY NIGHT AS THE
BAROCLINIC ZONE SETS UP NEAR THE FORECAST AREA AND POTENTIALLY
BECOMES THE FOCUS MECHANISM OF ADDITIONAL LIGHT PRECIPITATION AS
WARM AIR ADVECTION LIFTS INTO CENTRAL SD AND THE MID MISSOURI
VALLEY. CONFIDENCE IS FAIRLY LOW WITH WHERE THIS WILL SET UP...BUT
WILL LEAVE SOME ISOLATED LIGHT SNOWFALL MENTION WEDNESDAY AND
WEDNESDAY NIGHT.
MODELS WAVER WITH BRINGING FURTHER WAVES ALONG THE FLOW...BUT NOT A
LOT OF CONFIDENCE IN THE TIMING. THANKSGIVING LOOKS TO BE THE
COLDEST DAY IN THE EXTENDED WITH HIGHS ONLY IN THE TEENS AND LOWER
20S FOLLOWED BY THURSDAY NIGHT LOWS IN THE SINGLE DIGITS. FRIDAY
TEMPERATURES MODERATE SOME INTO THE UPPER TEENS TO NEAR 30.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 553 PM CST SAT NOV 22 2014
EXPECT MVFR TO IFR CIGS AND VIS TO RETURN TO NORTHWEST IOWA AND
ADJACENT PORTIONS OF SOUTHWEST MINNESOTA TONIGHT...SO INCLUDED
MENTION IN THE KSUX TAF. STILL A POSSIBILITY WE SEE LIFR CIGS AND
AREAS OF DENSE FOG...SO SOMETHING TO WATCH. AGAIN KFSD WILL BE
NEAR THE EDGE OF THIS STRATUS AND FOG...BUT BASED ON LATEST MODEL
GUIDANCE LEANING TOWARDS THEM STAYING VFR...BUT WILL CONTINUE TO
MONITOR. EXPECT ANY STRATUS TO CLEAR EARLY TO MID MORNING AS A
FRONT SWITCHES WINDS TO THE WEST AND NORTHWEST. COULD BE A LITTLE
LIGHT RAIN...POSSIBLY MIXED WITH SNOW...AS THE FRONT CROSSES...BUT
NOT EXPECTING ANYTHING OF SIGNIFICANCE AT THIS TIME. WINDS WILL
INCREASE BEHIND THE FRONT...AND BY LATE MORNING AND AFTERNOON
EXPECTING GUSTS TO 30 KTS TO BE COMMON...AND COULD POTENTIALLY BE
HIGHER. ALSO SHOULD SEE STRATOCU DEVELOPMENT BEHIND THE FRONT IN
THE COLD AIR ADVECTION REGIME...WITH HEIGHTS LIKELY HIGH END MVFR
OR LOW END VFR.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...CHENARD
SHORT TERM...
LONG TERM...
AVIATION...CHENARD
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1158 AM CST FRI NOV 21 2014
.DISCUSSION...
UPDATED FOR 18Z AVIATION UPDATE
&&
.PREV DISCUSSION... /ISSUED 1030 AM CST FRI NOV 21 2014/
UPDATE...
AT 10 AM A WARM FRONT WAS LOCATED ACROSS CENTRAL
MISSISSIPPI...WHILE TEMPERATURES AROUND THE MIDSOUTH RANGED FROM
THE UPPER 30S TO THE MID 50S. SHOWERS WERE ONGOING MAINLY WEST OF
THE MISSISSIPPI RIVER AND WERE DIMINISHING EAST OF THE RIVER. THE
FORECAST LOOKS TO BE ON TRACK BASED ON THESE TRENDS AND THUS NO
UPDATES ARE NECESSARY.
ZDM
PREV DISCUSSION... /ISSUED 501 AM CST FRI NOV 21 2014/
A WARM FRONT WAS LOCATED JUST SOUTH OF THE MIDSOUTH EARLY THIS
MORNING...EXTENDING WEST TO EAST FROM SOUTHERN ARKANSAS INTO NORTH
CENTRAL MS. ISENTROPIC LIFT NORTH OF THIS FRONT WAS CAUSING AREAS OF
RAIN FROM EAST CENTRAL AR INTO NORTH MS. THE MIDSOUTH WAS IN THE
COOL SECTOR WITH TEMPERATURES IN THE 30S AND 40S ALONG WITH A LIGHT
EASTERLY WIND.
THE FRONT WILL LIFT SLOWLY NORTHWARD TODAY WITH RAIN CONTINUING TO
SPREAD INTO THE MIDSOUTH THIS MORNING...ESPECIALLY FROM EASTERN
AR ACROSS PORTIONS OF SOUTHWEST TN INTO NORTHWEST MS. INCREASED
THE POPS THIS MORNING BASED ON THE HRRR MODEL. AREAS TO THE NORTH
OF THE WARM FRONT WILL REMAIN UNSEASONABLY COOL TODAY WHILE
LOCATIONS FURTHER TO THE SOUTH WILL SEE HIGH TEMPERATURES CLIMBING
CLOSE TO NORMAL. THE BEST CHANCES FOR RAIN THIS AFTERNOON WILL BE
FROM PORTIONS OF EASTERN AR...THE MO BOOTHEEL...INTO PORTIONS OF
NORTHWEST TN.
BY SATURDAY...THE WARM FRONT WILL LIFT NORTH OF THE REGION WITH A
STRENGTHENING SOUTHEAST LOW LEVEL WIND FLOW. UPPER LEVEL RIDGING
WILL INCREASE ACROSS THE MIDSOUTH AS AN UPPER LEVEL TROUGH MOVES
THROUGH THE SOUTHERN PLAINS. MUCH OF THE MIDSOUTH WILL BE RAIN FREE
WITH THE BEST CHANCE FOR SHOWERS ACROSS PORTIONS OF NORTHEAST AR AND
THE MO BOOTHEEL. HIGH TEMPERATURES WILL CLIMB INTO THE 60S MAKING
FOR A NICE DAY ACROSS MUCH OF THE MIDSOUTH...AND RELATIVELY WARM
CONSIDERING THE RECENT COLD. LOW LEVEL DEW POINTS WILL CREEP UPWARD
BUT STILL REMAIN ON THE LOW SIDE WITH THE SOUTHEAST WIND FLOW.
SATURDAY NIGHT AND SUNDAY...STILL LOOKS LIKE A WET PERIOD
BEGINNING MAINLY AFTER MIDNIGHT SATURDAY NIGHT. THE UPPER LEVEL
TROUGH OVER THE SOUTHERN PLAINS WILL LIFT QUICKLY NORTHEASTWARD
ACROSS THE MIDSOUTH AS A STRONG AND VIGOROUS NEGATIVELY TILTED
SYSTEM. DEEPENING SURFACE LOW PRESSURE IN ASSOCIATION WITH THIS
SYSTEM WILL MOVE NEAR THE MIDSOUTH. 00Z MODELS WERE SLIGHTLY
SLOWER WITH THIS SYSTEM THAN EARLIER RUNS. LOOKS LIKE WIDESPREAD
SHOWERS AND SCATTERED THUNDERSTORMS WILL MOVE INTO THE MIDSOUTH
FROM THE SOUTHWEST MAINLY AFTER MIDNIGHT SATURDAY
NIGHT...CONTINUING ACROSS THE ENTIRE AREA SUNDAY MORNING...BEFORE
DIMINISHING FROM THE SOUTHWEST SUNDAY AFTERNOON. PRECIPITABLE
WATER VALUES WILL INCREASE TO AROUND 1.5 INCHES AS STRENGTHENING
SOUTHERLY WINDS TAP INTO GULF MOISTURE. THINK SOME LOCATIONS WILL
SEE HEAVY DOWNPOURS SO ADDED LOCALLY HEAVY RAINFALL TO THE
HAZARDOUS WEATHER OUTLOOK. MARGINAL INSTABILITY IS ELEVATED
SATURDAY NIGHT FROM EAST CENTRAL AR INTO NORTH MS. ELEVATED
INSTABILITY DOES INCREASE ACROSS THE REGION SUNDAY. IN
ADDITION...MODELS INDICATE INCREASING SURFACE BASED INSTABILITY
WORKING ITS WAY INTO THE REGION FROM THE SOUTH WITH THE HIGHEST
VALUES PUSHING INTO PORTIONS OF NORTH MS WHERE HIGH TEMPERATURES
ARE FORECAST TO REACH INTO THE LOWER 70S. CONTINUED TO MENTION A
FEW STRONG TO SEVERE THUNDERSTORMS IN THE HAZARDOUS WEATHER
OUTLOOK FOR SATURDAY NIGHT AND SUNDAY...THE BEST CHANCE LOOKS TO
BE ACROSS PORTIONS OF NORTH MS DURING THE DAY SUNDAY AND THIS WILL
DEPEND ON CONDITIONS WARMING AND DESTABILIZING FOLLOWING THE
WIDESPREAD RAIN THAT WILL MOVE THROUGH BEFOREHAND.
A COLD FRONT WILL MOVE THROUGH THE AREA SUNDAY NIGHT WITH A
CONTINUING THREAT OF SHOWERS FOR MUCH OF THE AREA...ENDING FROM THE
WEST MONDAY MORNING. CONTINUED WITH A DRY AND COOLER FORECAST FOR
MONDAY AFTERNOON INTO THURSDAY. THE ECMWF AND GFS CONTINUE TO
DISAGREE WEDNESDAY NIGHT WITH THE ECMWF SHOWING COLD HIGH PRESSURE
BUILDING INTO THE AREA WHILE THE GFS KEEPS THE COLDER AIR FURTHER
NORTH. CONTINUED WITH OUR CURRENT FORECAST...MORE OF A COMPROMISE.
BOTH MODELS SHOW DRY WEATHER FOR THANKSGIVING DAY.
JCL
&&
.AVIATION...
18Z TAF CYCLE
MVFR CIGS LIFTING NORTH ALONG WITH WARM FRONT. VFR CONDS WILL
PREVAIL AT KMEM...KMKL AND KTUP THROUGH THE PERIOD. MVFR CIGS
WILL REMAIN AT KJBR THROUGH 22/00Z...VFR THEREAFTER. EAST WINDS
AOB 8 KTS WILL VEER TO SOUTHEAST TONIGHT AND SOUTH ON SATURDAY.
SJM
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1030 AM CST FRI NOV 21 2014
.UPDATE...
AT 10 AM A WARM FRONT WAS LOCATED ACROSS CENTRAL
MISSISSIPPI...WHILE TEMPERATURES AROUND THE MIDSOUTH RANGED FROM
THE UPPER 30S TO THE MID 50S. SHOWERS WERE ONGOING MAINLY WEST OF
THE MISSISSIPPI RIVER AND WERE DIMINISHING EAST OF THE RIVER. THE
FORECAST LOOKS TO BE ON TRACK BASED ON THESE TRENDS AND THUS NO
UPDATES ARE NECESSARY.
ZDM
&&
.PREV DISCUSSION... /ISSUED 501 AM CST FRI NOV 21 2014/
A WARM FRONT WAS LOCATED JUST SOUTH OF THE MIDSOUTH EARLY THIS
MORNING...EXTENDING WEST TO EAST FROM SOUTHERN ARKANSAS INTO NORTH
CENTRAL MS. ISENTROPIC LIFT NORTH OF THIS FRONT WAS CAUSING AREAS OF
RAIN FROM EAST CENTRAL AR INTO NORTH MS. THE MIDSOUTH WAS IN THE
COOL SECTOR WITH TEMPERATURES IN THE 30S AND 40S ALONG WITH A LIGHT
EASTERLY WIND.
THE FRONT WILL LIFT SLOWLY NORTHWARD TODAY WITH RAIN CONTINUING TO
SRPEAD INTO THE MIDSOUTH THIS MORNING...ESPECIALLY FROM EASTERN AR
ACROSS PORTIONS OF SOUTHWEST TN INTO NORTHWEST MS. INCREASED THE
POPS THIS MORNING BASED ON THE HRRR MODEL. AREAS TO THE NORTH OF THE
WARM FRONT WILL REMAIN UNSEASONABLY COOL TODAY WHILE LOCATIONS
FURTHER TO THE SOUTH WILL SEE HIGH TEMPERATURES CLIMBING CLOSE TO
NORMAL. THE BEST CHANCES FOR RAIN THIS AFTERNOON WILL BE FROM
PORTIONS OF EASTERN AR...THE MO BOOTHEEL...INTO PORTIONS OF
NORTHWEST TN.
BY SATURDAY...THE WARM FRONT WILL LIFT NORTH OF THE REGION WITH A
STRENGTHENING SOUTHEAST LOW LEVEL WIND FLOW. UPPER LEVEL RIDGING
WILL INCREASE ACROSS THE MIDSOUTH AS AN UPPER LEVEL TROUGH MOVES
THROUGH THE SOUTHERN PLAINS. MUCH OF THE MIDSOUTH WILL BE RAIN FREE
WITH THE BEST CHANCE FOR SHOWERS ACROSS PORTIONS OF NORTHEAST AR AND
THE MO BOOTHEEL. HIGH TEMPERATURES WILL CLIMB INTO THE 60S MAKING
FOR A NICE DAY ACROSS MUCH OF THE MIDSOUTH...AND RELATIVELY WARM
CONSIDERING THE RECENT COLD. LOW LEVEL DEW POINTS WILL CREEP UPWARD
BUT STILL REMAIN ON THE LOW SIDE WITH THE SOUTHEAST WIND FLOW.
SATURDAY NIGHT AND SUNDAY...STILL LOOKS LIKE A WET PERIOD
BEGINNING MAINLY AFTER MIDNIGHT SATURDAY NIGHT. THE UPPER LEVEL
TROUGH OVER THE SOUTHERN PLAINS WILL LIFT QUICKLY NORTHEASTWARD
ACROSS THE MIDSOUTH AS A STRONG AND VIGOROUS NEGATIVELY TILTED
SYSTEM. DEEPENING SURFACE LOW PRESSURE IN ASSOCIATION WITH THIS
SYSTEM WILL MOVE NEAR THE MIDSOUTH. 00Z MODELS WERE SLIGHTLY
SLOWER WITH THIS SYSTEM THAN EARLIER RUNS. LOOKS LIKE WIDESPREAD
SHOWERS AND SCATTERED THUNDERSTORMS WILL MOVE INTO THE MIDSOUTH
FROM THE SOUTHWEST MAINLY AFTER MIDNIGHT SATURDAY
NIGHT...CONTINUING ACROSS THE ENTIRE AREA SUNDAY MORNING...BEFORE
DIMINISHING FROM THE SOUTHWEST SUNDAY AFTERNOON. PRECIPITABLE
WATER VALUES WILL INCREASE TO AROUND 1.5 INCHES AS STRENGTHENING
SOUTHERLY WINDS TAP INTO GULF MOISTURE. THINK SOME LOCATIONS WILL
SEE HEAVY DOWNPOURS SO ADDED LOCALLY HEAVY RAINFALL TO THE
HAZARDOUS WEATHER OUTLOOK. MARGINAL INSTABILITY IS ELEVATED
SATURDAY NIGHT FROM EAST CENTRAL AR INTO NORTH MS. ELEVATED
INSTABILITY DOES INCREASE ACROSS THE REGION SUNDAY. IN
ADDITION...MODELS INDICATE INCREASING SURFACE BASED INSTABILITY
WORKING ITS WAY INTO THE REGION FROM THE SOUTH WITH THE HIGHEST
VALUES PUSHING INTO PORTIONS OF NORTH MS WHERE HIGH TEMPERATURES
ARE FORECAST TO REACH INTO THE LOWER 70S. CONTINUED TO MENTION A
FEW STRONG TO SEVERE THUNDERSTORMS IN THE HAZARDOUS WEATHER
OUTLOOK FOR SATURDAY NIGHT AND SUNDAY...THE BEST CHANCE LOOKS TO
BE ACROSS PORTIONS OF NORTH MS DURING THE DAY SUNDAY AND THIS WILL
DEPEND ON CONDITIONS WARMING AND DESTABILIZING FOLLOWING THE
WIDESPREAD RAIN THAT WILL MOVE THROUGH BEFOREHAND.
A COLD FRONT WILL MOVE THROUGH THE AREA SUNDAY NIGHT WITH A
CONTINUING THREAT OF SHOWERS FOR MUCH OF THE AREA...ENDING FROM THE
WEST MONDAY MORNING. CONTINUED WITH A DRY AND COOLER FORECAST FOR
MONDAY AFTERNOON INTO THURSDAY. THE ECMWF AND GFS CONTINUE TO
DISAGREE WEDNESDAY NIGHT WITH THE ECMWF SHOWING COLD HIGH PRESSURE
BUILDING INTO THE AREA WHILE THE GFS KEEPS THE COLDER AIR FURTHER
NORTH. CONTINUED WITH OUR CURRENT FORECAST...MORE OF A COMPROMISE.
BOTH MODELS SHOW DRY WEATHER FOR THANKSGIVING DAY.
JCL
&&
.AVIATION...
12Z TAF CYCLE
MVFR CONDITIONS WILL DEVELOP ACROSS ALL TERMINALS THIS MORNING AS
LOWER DECKS...AROUND 2500 FT...MOVE INTO THE REGION. LIGHT SHOWER
ACTIVITY HAS ALSO BEEN NOTED WHICH WILL OVERSPREAD WESTERN
TERMINALS FIRST...THEN MKL TOWARD 14Z. DO EXPECT THE SHOWER
ACTIVITY TO END AROUND NOON TODAY AT ALL TERMINALS EXCEPT JBR
WHERE IT SHOULD BE PERSISTENT THROUGH THE VALID TAF PERIOD. CIGS
SHOULD RAISE AT MEM...MKL...AND TUP AS THE SHOWER ACTIVITY
DISSIPATES AND VFR CONDITIONS ARE EXPECTED THEREAFTER. JBR WILL
LIKELY REMAIN MVFR THROUGH MUCH OF THE PERIOD UNTIL AFTER 00Z
SATURDAY.
TVT
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
520 AM CST FRI NOV 21 2014
.UPDATE...
UPDATED FOR 12Z AVIATION DISCUSSION BELOW.
&&
.PREV DISCUSSION... /ISSUED 501 AM CST FRI NOV 21 2014/
A WARM FRONT WAS LOCATED JUST SOUTH OF THE MIDSOUTH EARLY THIS
MORNING...EXTENDING WEST TO EAST FROM SOUTHERN ARKANSAS INTO NORTH
CENTRAL MS. ISENTROPIC LIFT NORTH OF THIS FRONT WAS CAUSING AREAS OF
RAIN FROM EAST CENTRAL AR INTO NORTH MS. THE MIDSOUTH WAS IN THE
COOL SECTOR WITH TEMPERATURES IN THE 30S AND 40S ALONG WITH A LIGHT
EASTERLY WIND.
THE FRONT WILL LIFT SLOWLY NORTHWARD TODAY WITH RAIN CONTINUING TO
SRPEAD INTO THE MIDSOUTH THIS MORNING...ESPECIALLY FROM EASTERN AR
ACROSS PORTIONS OF SOUTHWEST TN INTO NORTHWEST MS. INCREASED THE
POPS THIS MORNING BASED ON THE HRRR MODEL. AREAS TO THE NORTH OF THE
WARM FRONT WILL REMAIN UNSEASONABLY COOL TODAY WHILE LOCATIONS
FURTHER TO THE SOUTH WILL SEE HIGH TEMPERATURES CLIMBING CLOSE TO
NORMAL. THE BEST CHANCES FOR RAIN THIS AFTERNOON WILL BE FROM
PORTIONS OF EASTERN AR...THE MO BOOTHEEL...INTO PORTIONS OF
NORTHWEST TN.
BY SATURDAY...THE WARM FRONT WILL LIFT NORTH OF THE REGION WITH A
STRENGTHENING SOUTHEAST LOW LEVEL WIND FLOW. UPPER LEVEL RIDGING
WILL INCREASE ACROSS THE MIDSOUTH AS AN UPPER LEVEL TROUGH MOVES
THROUGH THE SOUTHERN PLAINS. MUCH OF THE MIDSOUTH WILL BE RAIN FREE
WITH THE BEST CHANCE FOR SHOWERS ACROSS PORTIONS OF NORTHEAST AR AND
THE MO BOOTHEEL. HIGH TEMPERATURES WILL CLIMB INTO THE 60S MAKING
FOR A NICE DAY ACROSS MUCH OF THE MIDSOUTH...AND RELATIVELY WARM
CONSIDERING THE RECENT COLD. LOW LEVEL DEW POINTS WILL CREEP UPWARD
BUT STILL REMAIN ON THE LOW SIDE WITH THE SOUTHEAST WIND FLOW.
SATURDAY NIGHT AND SUNDAY...STILL LOOKS LIKE A WET PERIOD
BEGINNING MAINLY AFTER MIDNIGHT SATURDAY NIGHT. THE UPPER LEVEL
TROUGH OVER THE SOUTHERN PLAINS WILL LIFT QUICKLY NORTHEASTWARD
ACROSS THE MIDSOUTH AS A STRONG AND VIGOROUS NEGATIVELY TILTED
SYSTEM. DEEPENING SURFACE LOW PRESSURE IN ASSOCIATION WITH THIS
SYSTEM WILL MOVE NEAR THE MIDSOUTH. 00Z MODELS WERE SLIGHTLY
SLOWER WITH THIS SYSTEM THAN EARLIER RUNS. LOOKS LIKE WIDESPREAD
SHOWERS AND SCATTERED THUNDERSTORMS WILL MOVE INTO THE MIDSOUTH
FROM THE SOUTHWEST MAINLY AFTER MIDNIGHT SATURDAY
NIGHT...CONTINUING ACROSS THE ENTIRE AREA SUNDAY MORNING...BEFORE
DIMINISHING FROM THE SOUTHWEST SUNDAY AFTERNOON. PRECIPITABLE
WATER VALUES WILL INCREASE TO AROUND 1.5 INCHES AS STRENGTHENING
SOUTHERLY WINDS TAP INTO GULF MOISTURE. THINK SOME LOCATIONS WILL
SEE HEAVY DOWNPOURS SO ADDED LOCALLY HEAVY RAINFALL TO THE
HAZARDOUS WEATHER OUTLOOK. MARGINAL INSTABILITY IS ELEVATED
SATURDAY NIGHT FROM EAST CENTRAL AR INTO NORTH MS. ELEVATED
INSTABILITY DOES INCREASE ACROSS THE REGION SUNDAY. IN
ADDITION...MODELS INDICATE INCREASING SURFACE BASED INSTABILITY
WORKING ITS WAY INTO THE REGION FROM THE SOUTH WITH THE HIGHEST
VALUES PUSHING INTO PORTIONS OF NORTH MS WHERE HIGH TEMPERATURES
ARE FORECAST TO REACH INTO THE LOWER 70S. CONTINUED TO MENTION A
FEW STRONG TO SEVERE THUNDERSTORMS IN THE HAZARDOUS WEATHER
OUTLOOK FOR SATURDAY NIGHT AND SUNDAY...THE BEST CHANCE LOOKS TO
BE ACROSS PORTIONS OF NORTH MS DURING THE DAY SUNDAY AND THIS WILL
DEPEND ON CONDITIONS WARMING AND DESTABILIZING FOLLOWING THE
WIDESPREAD RAIN THAT WILL MOVE THROUGH BEFOREHAND.
A COLD FRONT WILL MOVE THROUGH THE AREA SUNDAY NIGHT WITH A
CONTINUING THREAT OF SHOWERS FOR MUCH OF THE AREA...ENDING FROM THE
WEST MONDAY MORNING. CONTINUED WITH A DRY AND COOLER FORECAST FOR
MONDAY AFTERNOON INTO THURSDAY. THE ECMWF AND GFS CONTINUE TO
DISAGREE WEDNESDAY NIGHT WITH THE ECMWF SHOWING COLD HIGH PRESSURE
BUILDING INTO THE AREA WHILE THE GFS KEEPS THE COLDER AIR FURTHER
NORTH. CONTINUED WITH OUR CURRENT FORECAST...MORE OF A COMPROMISE.
BOTH MODELS SHOW DRY WEATHER FOR THANKSGIVING DAY.
JCL
.AVIATION...
12Z TAF CYCLE
MVFR CONDITIONS WILL DEVELOP ACROSS ALL TERMINALS THIS MORNING AS
LOWER DECKS...AROUND 2500 FT...MOVE INTO THE REGION. LIGHT SHOWER
ACTIVITY HAS ALSO BEEN NOTED WHICH WILL OVERSPREAD WESTERN
TERMINALS FIRST...THEN MKL TOWARD 14Z. DO EXPECT THE SHOWER
ACTIVITY TO END AROUND NOON TODAY AT ALL TERMINALS EXCEPT JBR
WHERE IT SHOULD BE PERSISTENT THROUGH THE VALID TAF PERIOD. CIGS
SHOULD RAISE AT MEM...MKL...AND TUP AS THE SHOWER ACTIVITY
DISSIPATES AND VFR CONDITIONS ARE EXPECTED THEREAFTER. JBR WILL
LIKELY REMAIN MVFR THROUGH MUCH OF THE PERIOD UNTIL AFTER 00Z
SATURDAY.
TVT
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
501 AM CST FRI NOV 21 2014
.DISCUSSION...
A WARM FRONT WAS LOCATED JUST SOUTH OF THE MIDSOUTH EARLY THIS
MORNING...EXTENDING WEST TO EAST FROM SOUTHERN ARKANSAS INTO NORTH
CENTRAL MS. ISENTROPIC LIFT NORTH OF THIS FRONT WAS CAUSING AREAS OF
RAIN FROM EAST CENTRAL AR INTO NORTH MS. THE MIDSOUTH WAS IN THE
COOL SECTOR WITH TEMPERATURES IN THE 30S AND 40S ALONG WITH A LIGHT
EASTERLY WIND.
THE FRONT WILL LIFT SLOWLY NORTHWARD TODAY WITH RAIN CONTINUING TO
SRPEAD INTO THE MIDSOUTH THIS MORNING...ESPECIALLY FROM EASTERN AR
ACROSS PORTIONS OF SOUTHWEST TN INTO NORTHWEST MS. INCREASED THE
POPS THIS MORNING BASED ON THE HRRR MODEL. AREAS TO THE NORTH OF THE
WARM FRONT WILL REMAIN UNSEASONABLY COOL TODAY WHILE LOCATIONS
FURTHER TO THE SOUTH WILL SEE HIGH TEMPERATURES CLIMBING CLOSE TO
NORMAL. THE BEST CHANCES FOR RAIN THIS AFTERNOON WILL BE FROM
PORTIONS OF EASTERN AR...THE MO BOOTHEEL...INTO PORTIONS OF
NORTHWEST TN.
BY SATURDAY...THE WARM FRONT WILL LIFT NORTH OF THE REGION WITH A
STRENGTHENING SOUTHEAST LOW LEVEL WIND FLOW. UPPER LEVEL RIDGING
WILL INCREASE ACROSS THE MIDSOUTH AS AN UPPER LEVEL TROUGH MOVES
THROUGH THE SOUTHERN PLAINS. MUCH OF THE MIDSOUTH WILL BE RAIN FREE
WITH THE BEST CHANCE FOR SHOWERS ACROSS PORTIONS OF NORTHEAST AR AND
THE MO BOOTHEEL. HIGH TEMPERATURES WILL CLIMB INTO THE 60S MAKING
FOR A NICE DAY ACROSS MUCH OF THE MIDSOUTH...AND RELATIVELY WARM
CONSIDERING THE RECENT COLD. LOW LEVEL DEW POINTS WILL CREEP UPWARD
BUT STILL REMAIN ON THE LOW SIDE WITH THE SOUTHEAST WIND FLOW.
SATURDAY NIGHT AND SUNDAY...STILL LOOKS LIKE A WET PERIOD
BEGINNING MAINLY AFTER MIDNIGHT SATURDAY NIGHT. THE UPPER LEVEL
TROUGH OVER THE SOUTHERN PLAINS WILL LIFT QUICKLY NORTHEASTWARD
ACROSS THE MIDSOUTH AS A STRONG AND VIGOROUS NEGATIVELY TILTED
SYSTEM. DEEPENING SURFACE LOW PRESSURE IN ASSOCIATION WITH THIS
SYSTEM WILL MOVE NEAR THE MIDSOUTH. 00Z MODELS WERE SLIGHTLY
SLOWER WITH THIS SYSTEM THAN EARLIER RUNS. LOOKS LIKE WIDESPREAD
SHOWERS AND SCATTERED THUNDERSTORMS WILL MOVE INTO THE MIDSOUTH
FROM THE SOUTHWEST MAINLY AFTER MIDNIGHT SATURDAY
NIGHT...CONTINUING ACROSS THE ENTIRE AREA SUNDAY MORNING...BEFORE
DIMINISHING FROM THE SOUTHWEST SUNDAY AFTERNOON. PRECIPITABLE
WATER VALUES WILL INCREASE TO AROUND 1.5 INCHES AS STRENGTHENING
SOUTHERLY WINDS TAP INTO GULF MOISTURE. THINK SOME LOCATIONS WILL
SEE HEAVY DOWNPOURS SO ADDED LOCALLY HEAVY RAINFALL TO THE
HAZARDOUS WEATHER OUTLOOK. MARGINAL INSTABILITY IS ELEVATED
SATURDAY NIGHT FROM EAST CENTRAL AR INTO NORTH MS. ELEVATED
INSTABILITY DOES INCREASE ACROSS THE REGION SUNDAY. IN
ADDITION...MODELS INDICATE INCREASING SURFACE BASED INSTABILITY
WORKING ITS WAY INTO THE REGION FROM THE SOUTH WITH THE HIGHEST
VALUES PUSHING INTO PORTIONS OF NORTH MS WHERE HIGH TEMPERATURES
ARE FORECAST TO REACH INTO THE LOWER 70S. CONTINUED TO MENTION A
FEW STRONG TO SEVERE THUNDERSTORMS IN THE HAZARDOUS WEATHER
OUTLOOK FOR SATURDAY NIGHT AND SUNDAY...THE BEST CHANCE LOOKS TO
BE ACROSS PORTIONS OF NORTH MS DURING THE DAY SUNDAY AND THIS WILL
DEPEND ON CONDITIONS WARMING AND DESTABILIZING FOLLOWING THE
WIDESPREAD RAIN THAT WILL MOVE THROUGH BEFOREHAND.
A COLD FRONT WILL MOVE THROUGH THE AREA SUNDAY NIGHT WITH A
CONTINUING THREAT OF SHOWERS FOR MUCH OF THE AREA...ENDING FROM THE
WEST MONDAY MORNING. CONTINUED WITH A DRY AND COOLER FORECAST FOR
MONDAY AFTERNOON INTO THURSDAY. THE ECMWF AND GFS CONTINUE TO
DISAGREE WEDNESDAY NIGHT WITH THE ECMWF SHOWING COLD HIGH PRESSURE
BUILDING INTO THE AREA WHILE THE GFS KEEPS THE COLDER AIR FURTHER
NORTH. CONTINUED WITH OUR CURRENT FORECAST...MORE OF A COMPROMISE.
BOTH MODELS SHOW DRY WEATHER FOR THANKSGIVING DAY.
JCL
&&
.AVIATION...
06Z TAF CYCLE
VFR CONDITIONS WILL GRADUALLY DETERIORATE TO MVFR CONDITIONS
OVERNIGHT AND PERSIST DURING THE DAY FRIDAY WITH AN IMPROVEMENT TO
VFR CONDITIONS AFTER 22/00Z. A WARM FRONT WILL PUSH BACK NORTH
ACROSS THE AREA THROUGH THE PERIOD BRINGING A CHANCE OF RAIN TO
TAF SITES...ESPECIALLY JBR AND MEM. EAST WINDS ARE EXPECTED TO
AVERAGE BETWEEN 4-6 KTS TONIGHT THEN VEER ESE BETWEEN 4-8 KTS AT
SITES ON FRIDAY AND SSE AT TUP BY FRIDAY AFTERNOON.
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
938 PM CST SAT NOV 22 2014
.UPDATE... /CLEARING SVR WATCH COUNTIES FROM WEST...CONTINUE FFA/
AS A MINOR THREAT OF SEVERE WEATHER AND FLASH FLOODING CONTINUES
ACROSS SE COUNTIES...MUCH OF THE AREA HAS BEEN UPDATED TO REFLECT
A DECREASING CHANCE OF RAIN AND SEVERE WEATHER. THE FFA THREAT IS
LEFT IN PLACE...BUT MAY HAVE A POTENTIAL OF REMOVAL BEFORE THE END
OF THE EVENING. A FEW RIVERS AND STREAMS...MAINLY THOSE ALONG THE
EASTERN PART OF THE BALCONES ESCARPMENT...ARE OUT OF BANKS. SOME
SECONDARY ROADS WILL LIKELY REMAIN IMPASSABLE FOR A FEW MORE
HOURS. PRELIMINARY HIGHEST 2-DAY RAINFALL TOTALS APPEAR TO BE OUT
OF TRAVIS AND HAYS COUNTIES AT BETWEEN 4 AND 5.5 INCHES.
&&
.PREV DISCUSSION... /ISSUED 814 PM CST SAT NOV 22 2014/
UPDATE...
TO EXTEND SEVERE THUNDERSTORM WATCH.
DISCUSSION...
RISK OF SEVERE THUNDERSTORMS WILL CONTINUE WITH A LINE OF
THUNDERSTORMS MOVING TOWARD THE EAST. THE LINE CURRENTLY EXTENDS
FROM SAN ANTONIO TO PLEASANTON TO CROSS. AS THIS LINE MOVES TO THE
EAST THERE WILL BE A RISK FOR THUNDERSTORMS CAPABLE OF PRODUCING
LARGE HAIL AND DAMAGING WINDS. THERE IS ALSO A SLIGHT RISK FOR
TORNADOES. WE HAVE EXTENDED THE SEVERE THUNDERSTORM WATCH TO THE
COUNTIES EAST OF BEXAR AND ALONG AND SOUTH OF I-10.
PREV DISCUSSION... /ISSUED 715 PM CST SAT NOV 22 2014/
UPDATE... /SVR WATCH 557 EXTENSION INTO BEXAR...ATASCOSA/
A PROGRESSIVE SQUALL LINE IS QUICKLY SHIFTING THE SEVERE POTENTIAL
INTO THE SAN ANTONIO METRO AREA. APEX OF A CURVED SQUALL LINE
INCREASES THE POTENTIAL FOR SEVERE ACTIVITY ASSOCIATED WITH CELL
MERGERS AS NEW CONVECTION FORMS EAST OF THE LINE. CELL MERGERS
WILL ALSO BE POSSIBLE OVER PARTS OF ATASCOSA COUNTY BY 8 PM.
EXPECT TO SEE A HEAVY RAIN PRODUCING MCS TAKE SHAPE ONCE THE
MERGED CELLS MOVE EAST OF I-35...WITH DECREASING SEVERE POTENTIAL
BY 10 PM.
PREV DISCUSSION... /ISSUED 607 PM CST SAT NOV 22 2014/
UPDATE... /ISSUANCE OF FFA/
WITH THE MAJORITY OF HI-RES MODELS INDICATING LARGE AREAS OF 1-2
INCH RAINFALL STILL POSSIBLE OVER EASTERN COUNTIES...HAVE ISSUED A
FLASH FLOOD WATCH FOR COUNTIES ALONG AND EAST OF A LLANO TO SAN
ANTONIO LINE AND ALONG AND NORTH OF A SAN ANTONIO TO HALLETTSVILLE
LINE. THE FLASH FLOOD THREAT WILL PROBABLY BE ENHANCED THROUGH 9
PM OVER THE EASTERN HILL COUNTRY INTO AUSTIN METRO WITH SOME
TRAINING CELLS INCREASING FROM LAKE MEDINA TO BURNET. AFTER 9 PM...THE
FOCUS FOR FLOODING SHOULD BEGIN TO SHIFT EAST OF I-35. LCRA
HYDROMET INDICATES SEVERAL REPORTS OF 2 PLUS INCHES OF RAIN HAS
FALLEN STILL WITHIN THE PAST 6 HOURS OVER AREAS IN THE PATHS OF
NEW CONVECTION. ISOLATED MINOR RIVER RISES ARE EXPECTED...BUT
MODERATE FLOOD LEVELS ARE UNLIKELY. THE SEVERE THREAT CONTINUES
FOR MUCH OF THIS EVENING...ESPECIALLY OVER THE RIO GRANDE PLAINS.
HOWEVER...THE SEVERE THREAT SHOULD TREND TOWARD MORE ISOLATED
ACTIVITY LATE THIS EVENING.
PREV DISCUSSION... /ISSUED 551 PM CST SAT NOV 22 2014/
AVIATION...
MAIN CONCERN IS THE ONGOING CONVECTION ACROSS THE REGION. AN AREA
OF THUNDERSTORMS IS MOVING AWAY FROM DRT AND THERE WILL BE A
CHANCE FOR TSRA FOR THE NEXT COUPLE OF HOURS. THESE STORMS COULD
LOWER CIGS/VIS TO MVFR. SAN ANTONIO AIRPORTS WILL BE VFR AND RAIN
FREE FOR THE NEXT FEW HOURS. THEN THERE WILL BE A CHANCE FOR TSRA
TO LOWER CIGS/VIS TO IFR BETWEEN ABOUT 02Z AND 05Z. AT AUS CIGS
ARE IFR AND THERE WILL BE SHRA/TSRA AROUND FOR MUCH OF THE
EVENING. BY 06Z CONVECTION SHOULD END AND CONDITIONS WILL BE VFR AT
ALL TERMINALS THROUGH THE END OF THE PERIOD.
PREV DISCUSSION... /ISSUED 349 PM CST SAT NOV 22 2014/
THE RISK OF SEVERE WEATHER AND HEAVY RAIN CONTINUES
THROUGH THIS EVENING...
SHORT TERM (TONIGHT THROUGH SUNDAY NIGHT)...
STRONG STORMS AND HEAVY RAIN WILL CONTINUE TO AFFECT MAINLY THE
EASTERN HALF OF SOUTH CENTRAL TEXAS FOR THE NEXT SEVERAL HOURS.
THE THREAT FOR STRONG TO SEVERE WEATHER STILL EXISTS THROUGH THIS
EVENING. A SECOND ROUND OF SHOWERS AND STORMS CURRENTLY ONGOING
ACROSS THE SERRANIAS DEL BURRO (NORTHEAST MEXICO) IS FORECAST TO
PUSH EASTWARD AND ACROSS MOST OF SOUTH CENTRAL TEXAS THIS EVENING.
THE HRRR AND TECH-TECH HIRES MODELS DEVELOP AN MCS AROUND 23Z/5 PM
THIS AFTERNOON WHILE A LINE OF SHOWERS AND STORMS FORM AHEAD OF A
SURFACE CONVERGENCE ZONE (WARM SECTOR). IF THIS SCENARIO PANS
OUT...STRONG TO SEVERE STORMS ARE POSSIBLE ACROSS THE RIO
GRANDE...ESPECIALLY ALONG AND WEST OF ROCKSPRINGS TO HONDO TO
PEARSALL LINE. A SEVERE THUNDERSTORM WATCH IS IN EFFECT THROUGH 10
PM TONIGHT FOR THE AREA ABOVE MENTIONED. MAIN WEATHER THREATS WILL
BE LARGE HAIL AND DAMAGING WINDS. CAN`T RULE OUT AN ISOLATED
TORNADO OR TWO. SOME OF THESE STRONG STORMS WILL PRODUCE HEAVY
DOWNPOURS WITH RAINFALL ACCUMULATIONS UP TO ONE INCH PER HOUR.
THE MCS IS FORECAST TO COMBINE WITH THE SHOWERS AND STORMS
EXPECTED TO FORM ALONG THE CONVERGENCE ZONE AND MOVE EAST IN A
LINEAR FASHION...AFFECTING THE I-35 CORRIDOR AROUND 8 OR 9 PM THIS
EVENING. BY 9 PM...THE SYSTEM IS LIKELY TO TRANSITION TO A HEAVY
RAIN PRODUCER WITH STRONGER STORMS CAPABLE OF PRODUCING LARGE
HAIL. THE LINE OF STORMS WILL QUICKLY PUSH TO THE EAST BY MIDNIGHT
TONIGHT WITH RAIN CHANCES COMING TO AN END ACROSS THE ENTIRE AREA
BY 2 OR 3 AM SUNDAY. NEW RAINFALL AMOUNTS FOR THE TONIGHT PERIOD
COULD RANGE FROM 1 TO 2 INCHES AND UP TO 3 INCHES IN ISOLATED
PLACES.
ON SUNDAY...EXPECT MOSTLY SUNNY/CLEAR SKIES ACROSS SOUTH CENTRAL
TEXAS WITH BREEZY CONDITIONS. A PACIFIC COLD FRONT WILL PUSH
ACROSS THE REGION SUNDAY NIGHT INTO MONDAY.
LONG TERM (MONDAY THROUGH SATURDAY)...
THE WEATHER IS EXPECTED TO BE FAIRLY QUIET FOR MUCH OF NEXT WEEK. A
WEAK FRONT WILL MOVE THROUGH THE AREA OVERNIGHT SUNDAY. THIS FRONT
IS IN RESPONSE TO AN UPPER LEVEL TROUGH MOVING THROUGH THE PLAINS.
THE WEATHER FOR THANKSGIVING SHOULD BE PRETTY SEASONAL WITH HIGHS
IN THE 60S AND LOWS IN THE 30S/40S.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 55 78 45 64 40 / 40 0 - - -
AUSTIN BERGSTROM INTL AIRPORT 54 77 43 64 37 / 70 0 - - -
NEW BRAUNFELS MUNI AIRPORT 55 79 45 66 40 / 40 0 - - -
BURNET MUNI AIRPORT 52 75 42 62 38 / 20 0 - - -
DEL RIO INTL AIRPORT 50 78 46 65 38 / 10 0 - - -
GEORGETOWN MUNI AIRPORT 54 75 43 62 38 / 40 0 - - -
HONDO MUNI AIRPORT 49 77 42 65 37 / 10 0 - - -
SAN MARCOS MUNI AIRPORT 53 78 44 65 39 / 40 0 - - -
LA GRANGE - FAYETTE REGIONAL 57 78 46 64 40 / 90 0 - - -
SAN ANTONIO INTL AIRPORT 54 78 46 66 41 / 20 0 - - -
STINSON MUNI AIRPORT 54 79 46 66 41 / 20 0 - - -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL MIDNIGHT CST TONIGHT FOR THE FOLLOWING
COUNTIES: BASTROP...BEXAR...BLANCO...BURNET...CALDWELL...COMAL...
FAYETTE...GONZALES...GUADALUPE...HAYS...LAVACA...LEE...LLANO...
TRAVIS...WILLIAMSON.
&&
$$
MESOSCALE/AVIATION...05
SYNOPTIC/GRIDS...18
PUBLIC SERVICE/DATA COLLECTION...30
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
911 PM CST SAT NOV 22 2014
.DISCUSSION...
THE UPPER TROUGH WAS SWINGING THROUGH THE SOUTHERN PART OF THE
STATE AT 845 PM...WITH VERY GOOD DIFFLUENCE NOTED AT 300 MB
OVERHEAD OF SE TX. WITH A STATIONARY FRONT JUST WEST OF KCLL AND
CROCKETT...AM EXPECTING WIDESPREAD RAIN AND THUNDERSTORMS ACROSS
THE FORECAST AREA THROUGH MIDNIGHT. LIKE THE 01Z HRRR AND THE 00Z
NAM12 WHICH PUSHES THE BEST CHANCES FOR THUNDERSTORMS EAST OF
INTERSTATE 45 BETWEEN MIDNIGHT AND 2 AM. THIS TIMING WILL BE TIED
TO THE DEVELOPMENT AND EVOLUTION OF THE TWO DOMINATE LINES OF
CONVECTION WHICH WERE FORMING AT 9 PM. ONE WAS ALONG THE
INTERSTATE 35 CORRIDOR AND THE OTHER FROM NEAR FRIENDSWOOD AND
PEARLAND SOUTH TO JUST OFF THE MID TX COAST.
AGREE WITH SPC WITH THE UPDATED SLIGHT RISK FOR SEVERE STORMS
BEING MAINLY ALONG AND SOUTH OF A LINE FROM NEAR COLLEGE STATION
TO DAYTON IN SOUTHERN LIBERTY COUNTY. THIS MEANS THAT ISOLATED
SEVERE STORMS ARE POSSIBLE WITH THE MAIN THREATS STRONG WINDS AND
SMALL HAIL. WHERE TRAINING OF STORMS OCCUR...MINOR FLOODING IS
POSSIBLE. SOME LOCATIONS ACROSS WASHINGTON...GRIMES...AND INTO
WALKER COUNTIES HAVE ALREADY RECEIVED UP TO 3 INCHES OF RAIN.
WILL UPDATE THE FORECAST TO TWEAK THE BETTER RAIN CHANCES TO PAST
MIDNIGHT.
40
&&
.PREV DISCUSSION... /ISSUED 603 PM CST SAT NOV 22 2014/
DISCUSSION...
00Z TAF DISCUSSION IN AVIATION SECTION.
AVIATION...
WATER VAPOR IMAGERY SHOWS LEAD SHORT WAVE AHEAD OF MAIN UPPER LOW
OVER BIG BEND/RIO GRANDE VALLEY MOVING ACROSS SE TX. SFC ANALYSIS
HAS WARM FRONT DIAGONAL FROM NORTH OF KAUS TO KCLL DOWN TO THE
GOLDEN TRIANGLE. SECOND ROUND OF CONVECTION BASED ON HRRR/RAP
TRENDS IS EXPECTED TO PUSH ACROSS THE AREA AROUND 06Z. ALREADY
SEEING THE START OF A SQUALL LINE DEVELOPING UNDER UPPER LOW OVER
WEST HILL COUNTRY.
KCLL/KUTS/KCXO...FAIRLY STOUT CLUSTER OF TSRA W OF KUTS AND E OF
KCLL WILL MOVE THROUGH THE AREA OVER THE NEXT HR OR TWO. MAIN
IMPACT WILL BE FOR KUTS WITH CIGS DROPPING TO IFR WITH GUSTY
WINDS. THINK SQUALL LINE OF STORMS WILL REACH THESE TERMINALS
03-04Z AND MOVING OUT PAST 06-07Z. CIGS AND OVERALL AVIATION
CONDITIONS SHOULD IMPROVE AFTER THAT WITH SW WINDS TOMORROW.
KIAH/KHOU/KSGR...CURRENT AREA OF SHRA AND ISO TSRA WILL BE MOVING
THROUGH HOUSTON TERMINALS OVER THE NEXT HR. STORMS MAY DROP CIGS
TO IFR WITH SOME LIMITED VSBY AND GUSTY WINDS. SHOULD HAVE A BREAK
FOR A FEW HRS AHEAD OF NEXT ROUND OF STORMS WHICH SHOULD BE A
DEVELOPING SQUALL LINE. LOOK FOR STORMS TO REACH HOUSTON TERMINALS
05-07Z SO ADDED TEMPO FOR +TSRA AND GUSTY WINDS. ONCE LINE MOVES
THROUGH EXPECT CIGS TO IMPROVE ALONG WITH OVERALL AVIATION WEATHER
CONDITIONS. VFR TOMORROW WITH SW WINDS.
KLBX/KGLS...LINE OF SHRA CURRENTLY MOVING THROUGH TERMINALS SHOULD
BE SHORT LIVED AND MOVE OUT WITHIN THE NEXT HR. MAIN CONCERN WILL
BE LATER TONIGHT FROM 05-08Z WHEN A LINE OF STORMS MOVES THROUGH
THE AREA. MENTION +TSRA AND GUSTY WINDS FOR POSSIBLE SQUALL LINE
THAT WILL PUSH THROUGH. CIGS AND OVERALL CONDITIONS WILL IMPROVE
AFTER 08-09Z. VFR TOMORROW WITH SW WINDS.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 57 78 45 64 40 / 90 10 0 0 0
HOUSTON (IAH) 59 80 49 65 41 / 90 10 0 0 0
GALVESTON (GLS) 65 76 56 64 50 / 90 10 0 0 0
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION THROUGH SUNDAY AFTERNOON FOR
THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS
FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...
WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.
SMALL CRAFT ADVISORY UNTIL 6 PM CST SUNDAY FOR THE FOLLOWING
ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL
20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO
60 NM.
&&
$$
DISCUSSION...40
AVIATION/MARINE...39
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
814 PM CST SAT NOV 22 2014
.UPDATE...
TO EXTEND SEVERE THUNDERSTORM WATCH.
&&
.DISCUSSION...
RISK OF SEVERE THUNDERSTORMS WILL CONTINUE WITH A LINE OF
THUNDERSTORMS MOVING TOWARD THE EAST. THE LINE CURRENTLY EXTENDS
FROM SAN ANTONIO TO PLEASANTON TO CROSS. AS THIS LINE MOVES TO THE
EAST THERE WILL BE A RISK FOR THUNDERSTORMS CAPABLE OF PRODUCING
LARGE HAIL AND DAMAGING WINDS. THERE IS ALSO A SLIGHT RISK FOR
TORNADOES. WE HAVE EXTENDED THE SEVERE THUNDERSTORM WATCH TO THE
COUNTIES EAST OF BEXAR AND ALONG AND SOUTH OF I-10.
&&
.PREV DISCUSSION... /ISSUED 715 PM CST SAT NOV 22 2014/
UPDATE... /SVR WATCH 557 EXTENSION INTO BEXAR...ATASCOSA/
A PROGRESSIVE SQUALL LINE IS QUICKLY SHIFTING THE SEVERE POTENTIAL
INTO THE SAN ANTONIO METRO AREA. APEX OF A CURVED SQUALL LINE
INCREASES THE POTENTIAL FOR SEVERE ACTIVITY ASSOCIATED WITH CELL
MERGERS AS NEW CONVECTION FORMS EAST OF THE LINE. CELL MERGERS
WILL ALSO BE POSSIBLE OVER PARTS OF ATASCOSA COUNTY BY 8 PM.
EXPECT TO SEE A HEAVY RAIN PRODUCING MCS TAKE SHAPE ONCE THE
MERGED CELLS MOVE EAST OF I-35...WITH DECREASING SEVERE POTENTIAL
BY 10 PM.
PREV DISCUSSION... /ISSUED 607 PM CST SAT NOV 22 2014/
UPDATE... /ISSUANCE OF FFA/
WITH THE MAJORITY OF HI-RES MODELS INDICATING LARGE AREAS OF 1-2
INCH RAINFALL STILL POSSIBLE OVER EASTERN COUNTIES...HAVE ISSUED A
FLASH FLOOD WATCH FOR COUNTIES ALONG AND EAST OF A LLANO TO SAN
ANTONIO LINE AND ALONG AND NORTH OF A SAN ANTONIO TO HALLETTSVILLE
LINE. THE FLASH FLOOD THREAT WILL PROBABLY BE ENHANCED THROUGH 9
PM OVER THE EASTERN HILL COUNTRY INTO AUSTIN METRO WITH SOME
TRAINING CELLS INCREASING FROM LAKE MEDINA TO BURNET. AFTER 9 PM...THE
FOCUS FOR FLOODING SHOULD BEGIN TO SHIFT EAST OF I-35. LCRA
HYDROMET INDICATES SEVERAL REPORTS OF 2 PLUS INCHES OF RAIN HAS
FALLEN STILL WITHIN THE PAST 6 HOURS OVER AREAS IN THE PATHS OF
NEW CONVECTION. ISOLATED MINOR RIVER RISES ARE EXPECTED...BUT
MODERATE FLOOD LEVELS ARE UNLIKELY. THE SEVERE THREAT CONTINUES
FOR MUCH OF THIS EVENING...ESPECIALLY OVER THE RIO GRANDE PLAINS.
HOWEVER...THE SEVERE THREAT SHOULD TREND TOWARD MORE ISOLATED
ACTIVITY LATE THIS EVENING.
PREV DISCUSSION... /ISSUED 551 PM CST SAT NOV 22 2014/
AVIATION...
MAIN CONCERN IS THE ONGOING CONVECTION ACROSS THE REGION. AN AREA
OF THUNDERSTORMS IS MOVING AWAY FROM DRT AND THERE WILL BE A
CHANCE FOR TSRA FOR THE NEXT COUPLE OF HOURS. THESE STORMS COULD
LOWER CIGS/VIS TO MVFR. SAN ANTONIO AIRPORTS WILL BE VFR AND RAIN
FREE FOR THE NEXT FEW HOURS. THEN THERE WILL BE A CHANCE FOR TSRA
TO LOWER CIGS/VIS TO IFR BETWEEN ABOUT 02Z AND 05Z. AT AUS CIGS
ARE IFR AND THERE WILL BE SHRA/TSRA AROUND FOR MUCH OF THE
EVENING. BY 06Z CONVECTION SHOULD END AND CONDITIONS WILL BE VFR AT
ALL TERMINALS THROUGH THE END OF THE PERIOD.
PREV DISCUSSION... /ISSUED 349 PM CST SAT NOV 22 2014/
THE RISK OF SEVERE WEATHER AND HEAVY RAIN CONTINUES
THROUGH THIS EVENING...
SHORT TERM (TONIGHT THROUGH SUNDAY NIGHT)...
STRONG STORMS AND HEAVY RAIN WILL CONTINUE TO AFFECT MAINLY THE
EASTERN HALF OF SOUTH CENTRAL TEXAS FOR THE NEXT SEVERAL HOURS.
THE THREAT FOR STRONG TO SEVERE WEATHER STILL EXISTS THROUGH THIS
EVENING. A SECOND ROUND OF SHOWERS AND STORMS CURRENTLY ONGOING
ACROSS THE SERRANIAS DEL BURRO (NORTHEAST MEXICO) IS FORECAST TO
PUSH EASTWARD AND ACROSS MOST OF SOUTH CENTRAL TEXAS THIS EVENING.
THE HRRR AND TECH-TECH HIRES MODELS DEVELOP AN MCS AROUND 23Z/5 PM
THIS AFTERNOON WHILE A LINE OF SHOWERS AND STORMS FORM AHEAD OF A
SURFACE CONVERGENCE ZONE (WARM SECTOR). IF THIS SCENARIO PANS
OUT...STRONG TO SEVERE STORMS ARE POSSIBLE ACROSS THE RIO
GRANDE...ESPECIALLY ALONG AND WEST OF ROCKSPRINGS TO HONDO TO
PEARSALL LINE. A SEVERE THUNDERSTORM WATCH IS IN EFFECT THROUGH 10
PM TONIGHT FOR THE AREA ABOVE MENTIONED. MAIN WEATHER THREATS WILL
BE LARGE HAIL AND DAMAGING WINDS. CAN`T RULE OUT AN ISOLATED
TORNADO OR TWO. SOME OF THESE STRONG STORMS WILL PRODUCE HEAVY
DOWNPOURS WITH RAINFALL ACCUMULATIONS UP TO ONE INCH PER HOUR.
THE MCS IS FORECAST TO COMBINE WITH THE SHOWERS AND STORMS
EXPECTED TO FORM ALONG THE CONVERGENCE ZONE AND MOVE EAST IN A
LINEAR FASHION...AFFECTING THE I-35 CORRIDOR AROUND 8 OR 9 PM THIS
EVENING. BY 9 PM...THE SYSTEM IS LIKELY TO TRANSITION TO A HEAVY
RAIN PRODUCER WITH STRONGER STORMS CAPABLE OF PRODUCING LARGE
HAIL. THE LINE OF STORMS WILL QUICKLY PUSH TO THE EAST BY MIDNIGHT
TONIGHT WITH RAIN CHANCES COMING TO AN END ACROSS THE ENTIRE AREA
BY 2 OR 3 AM SUNDAY. NEW RAINFALL AMOUNTS FOR THE TONIGHT PERIOD
COULD RANGE FROM 1 TO 2 INCHES AND UP TO 3 INCHES IN ISOLATED
PLACES.
ON SUNDAY...EXPECT MOSTLY SUNNY/CLEAR SKIES ACROSS SOUTH CENTRAL
TEXAS WITH BREEZY CONDITIONS. A PACIFIC COLD FRONT WILL PUSH
ACROSS THE REGION SUNDAY NIGHT INTO MONDAY.
LONG TERM (MONDAY THROUGH SATURDAY)...
THE WEATHER IS EXPECTED TO BE FAIRLY QUIET FOR MUCH OF NEXT WEEK. A
WEAK FRONT WILL MOVE THROUGH THE AREA OVERNIGHT SUNDAY. THIS FRONT
IS IN RESPONSE TO AN UPPER LEVEL TROUGH MOVING THROUGH THE PLAINS.
THE WEATHER FOR THANKSGIVING SHOULD BE PRETTY SEASONAL WITH HIGHS
IN THE 60S AND LOWS IN THE 30S/40S.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 55 78 45 64 40 / 60 0 - - -
AUSTIN BERGSTROM INTL AIRPORT 54 77 43 64 37 / 70 0 - - -
NEW BRAUNFELS MUNI AIRPORT 55 79 45 66 40 / 60 0 - - -
BURNET MUNI AIRPORT 52 75 42 62 38 / 50 0 - - -
DEL RIO INTL AIRPORT 50 78 46 65 38 / 30 0 - - -
GEORGETOWN MUNI AIRPORT 54 75 43 62 38 / 60 0 - - -
HONDO MUNI AIRPORT 49 77 42 65 37 / 50 0 - - -
SAN MARCOS MUNI AIRPORT 53 78 44 65 39 / 70 0 - - -
LA GRANGE - FAYETTE REGIONAL 57 78 46 64 40 / 90 0 - - -
SAN ANTONIO INTL AIRPORT 54 78 46 66 41 / 50 0 - - -
STINSON MUNI AIRPORT 54 79 46 66 41 / 60 0 - - -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL MIDNIGHT CST TONIGHT FOR THE FOLLOWING
COUNTIES: BASTROP...BEXAR...BLANCO...BURNET...CALDWELL...COMAL...
FAYETTE...GONZALES...GUADALUPE...HAYS...LAVACA...LEE...LLANO...
TRAVIS...WILLIAMSON.
&&
$$
MESOSCALE/AVIATION...05
SYNOPTIC/GRIDS...18
PUBLIC SERVICE/DATA COLLECTION...30
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
715 PM CST SAT NOV 22 2014
.UPDATE... /SVR WATCH 557 EXTENSION INTO BEXAR...ATASCOSA/
A PROGRESSIVE SQUALL LINE IS QUICKLY SHIFTING THE SEVERE POTENTIAL
INTO THE SAN ANTONIO METRO AREA. APEX OF A CURVED SQUALL LINE
INCREASES THE POTENTIAL FOR SEVERE ACTIVITY ASSOCIATED WITH CELL
MERGERS AS NEW CONVECTION FORMS EAST OF THE LINE. CELL MERGERS
WILL ALSO BE POSSIBLE OVER PARTS OF ATASCOSA COUNTY BY 8 PM.
EXPECT TO SEE A HEAVY RAIN PRODUCING MCS TAKE SHAPE ONCE THE
MERGED CELLS MOVE EAST OF I-35...WITH DECREASING SEVERE POTENTIAL
BY 10 PM.
&&
.PREV DISCUSSION... /ISSUED 607 PM CST SAT NOV 22 2014/
UPDATE... /ISSUANCE OF FFA/
WITH THE MAJORITY OF HI-RES MODELS INDICATING LARGE AREAS OF 1-2
INCH RAINFALL STILL POSSIBLE OVER EASTERN COUNTIES...HAVE ISSUED A
FLASH FLOOD WATCH FOR COUNTIES ALONG AND EAST OF A LLANO TO SAN
ANTONIO LINE AND ALONG AND NORTH OF A SAN ANTONIO TO HALLETTSVILLE
LINE. THE FLASH FLOOD THREAT WILL PROBABLY BE ENHANCED THROUGH 9
PM OVER THE EASTERN HILL COUNTRY INTO AUSTIN METRO WITH SOME
TRAINING CELLS INCREASING FROM LAKE MEDINA TO BURNET. AFTER 9 PM...THE
FOCUS FOR FLOODING SHOULD BEGIN TO SHIFT EAST OF I-35. LCRA
HYDROMET INDICATES SEVERAL REPORTS OF 2 PLUS INCHES OF RAIN HAS
FALLEN STILL WITHIN THE PAST 6 HOURS OVER AREAS IN THE PATHS OF
NEW CONVECTION. ISOLATED MINOR RIVER RISES ARE EXPECTED...BUT
MODERATE FLOOD LEVELS ARE UNLIKELY. THE SEVERE THREAT CONTINUES
FOR MUCH OF THIS EVENING...ESPECIALLY OVER THE RIO GRANDE PLAINS.
HOWEVER...THE SEVERE THREAT SHOULD TREND TOWARD MORE ISOLATED
ACTIVITY LATE THIS EVENING.
PREV DISCUSSION... /ISSUED 551 PM CST SAT NOV 22 2014/
AVIATION...
MAIN CONCERN IS THE ONGOING CONVECTION ACROSS THE REGION. AN AREA
OF THUNDERSTORMS IS MOVING AWAY FROM DRT AND THERE WILL BE A
CHANCE FOR TSRA FOR THE NEXT COUPLE OF HOURS. THESE STORMS COULD
LOWER CIGS/VIS TO MVFR. SAN ANTONIO AIRPORTS WILL BE VFR AND RAIN
FREE FOR THE NEXT FEW HOURS. THEN THERE WILL BE A CHANCE FOR TSRA
TO LOWER CIGS/VIS TO IFR BETWEEN ABOUT 02Z AND 05Z. AT AUS CIGS
ARE IFR AND THERE WILL BE SHRA/TSRA AROUND FOR MUCH OF THE
EVENING. BY 06Z CONVECTION SHOULD END AND CONDITIONS WILL BE VFR AT
ALL TERMINALS THROUGH THE END OF THE PERIOD.
PREV DISCUSSION... /ISSUED 349 PM CST SAT NOV 22 2014/
THE RISK OF SEVERE WEATHER AND HEAVY RAIN CONTINUES
THROUGH THIS EVENING...
SHORT TERM (TONIGHT THROUGH SUNDAY NIGHT)...
STRONG STORMS AND HEAVY RAIN WILL CONTINUE TO AFFECT MAINLY THE
EASTERN HALF OF SOUTH CENTRAL TEXAS FOR THE NEXT SEVERAL HOURS.
THE THREAT FOR STRONG TO SEVERE WEATHER STILL EXISTS THROUGH THIS
EVENING. A SECOND ROUND OF SHOWERS AND STORMS CURRENTLY ONGOING
ACROSS THE SERRANIAS DEL BURRO (NORTHEAST MEXICO) IS FORECAST TO
PUSH EASTWARD AND ACROSS MOST OF SOUTH CENTRAL TEXAS THIS EVENING.
THE HRRR AND TECH-TECH HIRES MODELS DEVELOP AN MCS AROUND 23Z/5 PM
THIS AFTERNOON WHILE A LINE OF SHOWERS AND STORMS FORM AHEAD OF A
SURFACE CONVERGENCE ZONE (WARM SECTOR). IF THIS SCENARIO PANS
OUT...STRONG TO SEVERE STORMS ARE POSSIBLE ACROSS THE RIO
GRANDE...ESPECIALLY ALONG AND WEST OF ROCKSPRINGS TO HONDO TO
PEARSALL LINE. A SEVERE THUNDERSTORM WATCH IS IN EFFECT THROUGH 10
PM TONIGHT FOR THE AREA ABOVE MENTIONED. MAIN WEATHER THREATS WILL
BE LARGE HAIL AND DAMAGING WINDS. CAN`T RULE OUT AN ISOLATED
TORNADO OR TWO. SOME OF THESE STRONG STORMS WILL PRODUCE HEAVY
DOWNSPOURS WITH RAINFALL ACCUMULATIONS UP TO ONE INCH PER HOUR.
THE MCS IS FORECAST TO COMBINE WITH THE SHOWERS AND STORMS
EXPECTED TO FORM ALONG THE CONVERGENCE ZONE AND MOVE EAST IN A
LINEAR FASHION...AFFECTING THE I-35 CORRIDOR AROUND 8 OR 9 PM THIS
EVENING. BY 9 PM...THE SYSTEM IS LIKELY TO TRANSITION TO A HEAVY
RAIN PRODUCER WITH STRONGER STORMS CAPABLE OF PRODUCING LARGE
HAIL. THE LINE OF STORMS WILL QUICKLY PUSH TO THE EAST BY MIDNIGHT
TONIGHT WITH RAIN CHANCES COMING TO AN END ACROSS THE ENTIRE AREA
BY 2 OR 3 AM SUNDAY. NEW RAINFALL AMOUNTS FOR THE TONIGHT PERIOD
COULD RANGE FROM 1 TO 2 INCHES AND UP TO 3 INCHES IN ISOLATED
PLACES.
ON SUNDAY...EXPECT MOSTLY SUNNY/CLEAR SKIES ACROSS SOUTH CENTRAL
TEXAS WITH BREEZY CONDITIONS. A PACIFIC COLD FRONT WILL PUSH
ACROSS THE REGION SUNDAY NIGHT INTO MONDAY.
LONG TERM (MONDAY THROUGH SATURDAY)...
THE WEATHER IS EXPECTED TO BE FAIRLY QUIET FOR MUCH OF NEXT WEEK. A
WEAK FRONT WILL MOVE THROUGH THE AREA OVERNIGHT SUNDAY. THIS FRONT
IS IN RESPONSE TO AN UPPER LEVEL TROUGH MOVING THROUGH THE PLAINS.
THE WEATHER FOR THANKSGIVING SHOULD BE PRETTY SEASONAL WITH HIGHS
IN THE 60S AND LOWS IN THE 30S/40S.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 55 78 45 64 40 / 60 0 - - -
AUSTIN BERGSTROM INTL AIRPORT 54 77 43 64 37 / 70 0 - - -
NEW BRAUNFELS MUNI AIRPORT 55 79 45 66 40 / 60 0 - - -
BURNET MUNI AIRPORT 52 75 42 62 38 / 50 0 - - -
DEL RIO INTL AIRPORT 50 78 46 65 38 / 30 0 - - -
GEORGETOWN MUNI AIRPORT 54 75 43 62 38 / 60 0 - - -
HONDO MUNI AIRPORT 49 77 42 65 37 / 50 0 - - -
SAN MARCOS MUNI AIRPORT 53 78 44 65 39 / 70 0 - - -
LA GRANGE - FAYETTE REGIONAL 57 78 46 64 40 / 90 0 - - -
SAN ANTONIO INTL AIRPORT 54 78 46 66 41 / 50 0 - - -
STINSON MUNI AIRPORT 54 79 46 66 41 / 60 0 - - -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL MIDNIGHT CST TONIGHT FOR THE FOLLOWING
COUNTIES: BASTROP...BEXAR...BLANCO...BURNET...CALDWELL...COMAL...
FAYETTE...GONZALES...GUADALUPE...HAYS...LAVACA...LEE...LLANO...
TRAVIS...WILLIAMSON.
&&
$$
MESOSCALE/AVIATION...05
SYNOPTIC/GRIDS...18
PUBLIC SERVICE/DATA COLLECTION...30
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
607 PM CST SAT NOV 22 2014
.UPDATE... /ISSUANCE OF FFA/
WITH THE MAJORITY OF HI-RES MODELS INDICATING LARGE AREAS OF 1-2
INCH RAINFALL STILL POSSIBLE OVER EASTERN COUNTIES...HAVE ISSUED A
FLASH FLOOD WATCH FOR COUNTIES ALONG AND EAST OF A LLANO TO SAN
ANTONIO LINE AND ALONG AND NORTH OF A SAN ANTONIO TO HALLETTSVILLE
LINE. THE FLASH FLOOD THREAT WILL PROBABLY BE ENHANCED THROUGH 9
PM OVER THE EASTERN HILL COUNTRY INTO AUSTIN METRO WITH SOME
TRAINING CELLS INCREASING FROM LAKE MEDINA TO BURNET. AFTER 9 PM...THE
FOCUS FOR FLOODING SHOULD BEGIN TO SHIFT EAST OF I-35. LCRA
HYDROMET INDICATES SEVERAL REPORTS OF 2 PLUS INCHES OF RAIN HAS
FALLEN STILL WITHIN THE PAST 6 HOURS OVER AREAS IN THE PATHS OF
NEW CONVECTION. ISOLATED MINOR RIVER RISES ARE EXPECTED...BUT
MODERATE FLOOD LEVELS ARE UNLIKELY. THE SEVERE THREAT CONTINUES
FOR MUCH OF THIS EVENING...ESPECIALLY OVER THE RIO GRANDE PLAINS.
HOWEVER...THE SEVERE THREAT SHOULD TREND TOWARD MORE ISOLATED
ACTIVITY LATE THIS EVENING.
&&
.PREV DISCUSSION... /ISSUED 551 PM CST SAT NOV 22 2014/
AVIATION...
MAIN CONCERN IS THE ONGOING CONVECTION ACROSS THE REGION. AN AREA
OF THUNDERSTORMS IS MOVING AWAY FROM DRT AND THERE WILL BE A
CHANCE FOR TSRA FOR THE NEXT COUPLE OF HOURS. THESE STORMS COULD
LOWER CIGS/VIS TO MVFR. SAN ANTONIO AIRPORTS WILL BE VFR AND RAIN
FREE FOR THE NEXT FEW HOURS. THEN THERE WILL BE A CHANCE FOR TSRA
TO LOWER CIGS/VIS TO IFR BETWEEN ABOUT 02Z AND 05Z. AT AUS CIGS
ARE IFR AND THERE WILL BE SHRA/TSRA AROUND FOR MUCH OF THE
EVENING. BY 06Z CONVECTION SHOULD END AND CONDITIONS WILL BE VFR AT
ALL TERMINALS THROUGH THE END OF THE PERIOD.
PREV DISCUSSION... /ISSUED 349 PM CST SAT NOV 22 2014/
.THE RISK OF SEVERE WEATHER AND HEAVY RAIN CONTINUES
THROUGH THIS EVENING...
SHORT TERM (TONIGHT THROUGH SUNDAY NIGHT)...
STRONG STORMS AND HEAVY RAIN WILL CONTINUE TO AFFECT MAINLY THE
EASTERN HALF OF SOUTH CENTRAL TEXAS FOR THE NEXT SEVERAL HOURS.
THE THREAT FOR STRONG TO SEVERE WEATHER STILL EXISTS THROUGH THIS
EVENING. A SECOND ROUND OF SHOWERS AND STORMS CURRENTLY ONGOING
ACROSS THE SERRANIAS DEL BURRO (NORTHEAST MEXICO) IS FORECAST TO
PUSH EASTWARD AND ACROSS MOST OF SOUTH CENTRAL TEXAS THIS EVENING.
THE HRRR AND TECH-TECH HIRES MODELS DEVELOP AN MCS AROUND 23Z/5 PM
THIS AFTERNOON WHILE A LINE OF SHOWERS AND STORMS FORM AHEAD OF A
SURFACE CONVERGENCE ZONE (WARM SECTOR). IF THIS SCENARIO PANS
OUT...STRONG TO SEVERE STORMS ARE POSSIBLE ACROSS THE RIO
GRANDE...ESPECIALLY ALONG AND WEST OF ROCKSPRINGS TO HONDO TO
PEARSALL LINE. A SEVERE THUNDERSTORM WATCH IS IN EFFECT THROUGH 10
PM TONIGHT FOR THE AREA ABOVE MENTIONED. MAIN WEATHER THREATS WILL
BE LARGE HAIL AND DAMAGING WINDS. CAN`T RULE OUT AN ISOLATED
TORNADO OR TWO. SOME OF THESE STRONG STORMS WILL PRODUCE HEAVY
DOWNSPOURS WITH RAINFALL ACCUMULATIONS UP TO ONE INCH PER HOUR.
THE MCS IS FORECAST TO COMBINE WITH THE SHOWERS AND STORMS
EXPECTED TO FORM ALONG THE CONVERGENCE ZONE AND MOVE EAST IN A
LINEAR FASHION...AFFECTING THE I-35 CORRIDOR AROUND 8 OR 9 PM THIS
EVENING. BY 9 PM...THE SYSTEM IS LIKELY TO TRANSITION TO A HEAVY
RAIN PRODUCER WITH STRONGER STORMS CAPABLE OF PRODUCING LARGE
HAIL. THE LINE OF STORMS WILL QUICKLY PUSH TO THE EAST BY MIDNIGHT
TONIGHT WITH RAIN CHANCES COMING TO AN END ACROSS THE ENTIRE AREA
BY 2 OR 3 AM SUNDAY. NEW RAINFALL AMOUNTS FOR THE TONIGHT PERIOD
COULD RANGE FROM 1 TO 2 INCHES AND UP TO 3 INCHES IN ISOLATED
PLACES.
ON SUNDAY...EXPECT MOSTLY SUNNY/CLEAR SKIES ACROSS SOUTH CENTRAL
TEXAS WITH BREEZY CONDITIONS. A PACIFIC COLD FRONT WILL PUSH
ACROSS THE REGION SUNDAY NIGHT INTO MONDAY.
LONG TERM (MONDAY THROUGH SATURDAY)...
THE WEATHER IS EXPECTED TO BE FAIRLY QUIET FOR MUCH OF NEXT WEEK. A
WEAK FRONT WILL MOVE THROUGH THE AREA OVERNIGHT SUNDAY. THIS FRONT
IS IN RESPONSE TO AN UPPER LEVEL TROUGH MOVING THROUGH THE PLAINS.
THE WEATHER FOR THANKSGIVING SHOULD BE PRETTY SEASONAL WITH HIGHS
IN THE 60S AND LOWS IN THE 30S/40S.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 55 78 45 64 40 / 60 0 - - -
AUSTIN BERGSTROM INTL AIRPORT 54 77 43 64 37 / 70 0 - - -
NEW BRAUNFELS MUNI AIRPORT 55 79 45 66 40 / 60 0 - - -
BURNET MUNI AIRPORT 52 75 42 62 38 / 50 0 - - -
DEL RIO INTL AIRPORT 50 78 46 65 38 / 30 0 - - -
GEORGETOWN MUNI AIRPORT 54 75 43 62 38 / 60 0 - - -
HONDO MUNI AIRPORT 49 77 42 65 37 / 50 0 - - -
SAN MARCOS MUNI AIRPORT 53 78 44 65 39 / 70 0 - - -
LA GRANGE - FAYETTE REGIONAL 57 78 46 64 40 / 90 0 - - -
SAN ANTONIO INTL AIRPORT 54 78 46 66 41 / 50 0 - - -
STINSON MUNI AIRPORT 54 79 46 66 41 / 60 0 - - -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL MIDNIGHT CST TONIGHT FOR THE FOLLOWING
COUNTIES: BASTROP...BEXAR...BLANCO...BURNET...CALDWELL...COMAL...
FAYETTE...GONZALES...GUADALUPE...HAYS...LAVACA...LEE...LLANO...
TRAVIS...WILLIAMSON.
&&
$$
MESOSCALE/AVIATION...05
SYNOPTIC/GRIDS...18
PUBLIC SERVICE/DATA COLLECTION...30
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
551 PM CST SAT NOV 22 2014
.AVIATION...
MAIN CONCERN IS THE ONGOING CONVECTION ACROSS THE REGION. AN AREA
OF THUNDERSTORMS IS MOVING AWAY FROM DRT AND THERE WILL BE A
CHANCE FOR TSRA FOR THE NEXT COUPLE OF HOURS. THESE STORMS COULD
LOWER CIGS/VIS TO MVFR. SAN ANTONIO AIRPORTS WILL BE VFR AND RAIN
FREE FOR THE NEXT FEW HOURS. THEN THERE WILL BE A CHANCE FOR TSRA
TO LOWER CIGS/VIS TO IFR BETWEEN ABOUT 02Z AND 05Z. AT AUS CIGS
ARE IFR AND THERE WILL BE SHRA/TSRA AROUND FOR MUCH OF THE
EVENING. BY 06Z CONVECTION SHOULD END AND CONDITIONS WILL BE VFR AT
ALL TERMINALS THROUGH THE END OF THE PERIOD.
&&
.PREV DISCUSSION... /ISSUED 349 PM CST SAT NOV 22 2014/
..THE RISK OF SEVERE WEATHER AND HEAVY RAIN CONTINUES
THROUGH THIS EVENING...
SHORT TERM (TONIGHT THROUGH SUNDAY NIGHT)...
STRONG STORMS AND HEAVY RAIN WILL CONTINUE TO AFFECT MAINLY THE
EASTERN HALF OF SOUTH CENTRAL TEXAS FOR THE NEXT SEVERAL HOURS.
THE THREAT FOR STRONG TO SEVERE WEATHER STILL EXISTS THROUGH THIS
EVENING. A SECOND ROUND OF SHOWERS AND STORMS CURRENTLY ONGOING
ACROSS THE SERRANIAS DEL BURRO (NORTHEAST MEXICO) IS FORECAST TO
PUSH EASTWARD AND ACROSS MOST OF SOUTH CENTRAL TEXAS THIS EVENING.
THE HRRR AND TECH-TECH HIRES MODELS DEVELOP AN MCS AROUND 23Z/5 PM
THIS AFTERNOON WHILE A LINE OF SHOWERS AND STORMS FORM AHEAD OF A
SURFACE CONVERGENCE ZONE (WARM SECTOR). IF THIS SCENARIO PANS
OUT...STRONG TO SEVERE STORMS ARE POSSIBLE ACROSS THE RIO
GRANDE...ESPECIALLY ALONG AND WEST OF ROCKSPRINGS TO HONDO TO
PEARSALL LINE. A SEVERE THUNDERSTORM WATCH IS IN EFFECT THROUGH 10
PM TONIGHT FOR THE AREA ABOVE MENTIONED. MAIN WEATHER THREATS WILL
BE LARGE HAIL AND DAMAGING WINDS. CAN`T RULE OUT AN ISOLATED
TORNADO OR TWO. SOME OF THESE STRONG STORMS WILL PRODUCE HEAVY
DOWNSPOURS WITH RAINFALL ACCUMULATIONS UP TO ONE INCH PER HOUR.
THE MCS IS FORECAST TO COMBINE WITH THE SHOWERS AND STORMS
EXPECTED TO FORM ALONG THE CONVERGENCE ZONE AND MOVE EAST IN A
LINEAR FASHION...AFFECTING THE I-35 CORRIDOR AROUND 8 OR 9 PM THIS
EVENING. BY 9 PM...THE SYSTEM IS LIKELY TO TRANSITION TO A HEAVY
RAIN PRODUCER WITH STRONGER STORMS CAPABLE OF PRODUCING LARGE
HAIL. THE LINE OF STORMS WILL QUICKLY PUSH TO THE EAST BY MIDNIGHT
TONIGHT WITH RAIN CHANCES COMING TO AN END ACROSS THE ENTIRE AREA
BY 2 OR 3 AM SUNDAY. NEW RAINFALL AMOUNTS FOR THE TONIGHT PERIOD
COULD RANGE FROM 1 TO 2 INCHES AND UP TO 3 INCHES IN ISOLATED
PLACES.
ON SUNDAY...EXPECT MOSTLY SUNNY/CLEAR SKIES ACROSS SOUTH CENTRAL
TEXAS WITH BREEZY CONDITIONS. A PACIFIC COLD FRONT WILL PUSH
ACROSS THE REGION SUNDAY NIGHT INTO MONDAY.
LONG TERM (MONDAY THROUGH SATURDAY)...
THE WEATHER IS EXPECTED TO BE FAIRLY QUIET FOR MUCH OF NEXT WEEK. A
WEAK FRONT WILL MOVE THROUGH THE AREA OVERNIGHT SUNDAY. THIS FRONT
IS IN RESPONSE TO AN UPPER LEVEL TROUGH MOVING THROUGH THE PLAINS.
THE WEATHER FOR THANKSGIVING SHOULD BE PRETTY SEASONAL WITH HIGHS
IN THE 60S AND LOWS IN THE 30S/40S.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 55 78 45 64 40 / 60 0 - - -
AUSTIN BERGSTROM INTL AIRPORT 54 77 43 64 37 / 70 0 - - -
NEW BRAUNFELS MUNI AIRPORT 55 79 45 66 40 / 60 0 - - -
BURNET MUNI AIRPORT 52 75 42 62 38 / 50 0 - - -
DEL RIO INTL AIRPORT 50 78 46 65 38 / 30 0 - - -
GEORGETOWN MUNI AIRPORT 54 75 43 62 38 / 60 0 - - -
HONDO MUNI AIRPORT 49 77 42 65 37 / 50 0 - - -
SAN MARCOS MUNI AIRPORT 53 78 44 65 39 / 70 0 - - -
LA GRANGE - FAYETTE REGIONAL 57 78 46 64 40 / 90 0 - - -
SAN ANTONIO INTL AIRPORT 54 78 46 66 41 / 50 0 - - -
STINSON MUNI AIRPORT 54 79 46 66 41 / 60 0 - - -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL MIDNIGHT CST TONIGHT FOR THE FOLLOWING
COUNTIES: BASTROP...BEXAR...BLANCO...BURNET...CALDWELL...COMAL...
FAYETTE...GONZALES...GUADALUPE...HAYS...LAVACA...LEE...LLANO...
TRAVIS...WILLIAMSON.
&&
$$
MESOSCALE/AVIATION...05
SYNOPTIC/GRIDS...18
PUBLIC SERVICE/DATA COLLECTION...30
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1150 AM CST FRI NOV 21 2014
.AVIATION...
UPPER LOW LOWER COLORADO VALLEY AT 18Z WILL MOVE TO JUST WEST OF
THE TEXAS BIG BEND BY 18Z SATURDAY. FLOW WILL BACK WITH APPROACH
OF THIS LOW ALLOWING MOISTURE TO INCREASE LATER TODAY AND TONIGHT.
MODEST LIFT AND INSTABILITY WILL BEGIN TO OVERSPREAD KLBB DURING
THE NIGHT...AND KCDS LATE TONIGHT THROUGH SATURDAY MORNING. KLBB
LOOKS LIKE ON BORDERLINE WITH CHANCE OF THUNDER...BETTER CHANCE
TO THE EAST...SO WILL HOLD OFF ON A TEMPO OR PROB MENTION. PERHAPS
A HIGHER CHANCE OF LIGHT SHOWERS OR DRIZZLE THOUGH WHICH WILL NEED
ADDITIONAL ASSESSMENT. RETAINED PREVIOUS TEMPO THUNDER FOR KCDS
LATER TONIGHT INTO SATURDAY MORNING. MUST ALSO BE MENTIONED THAT
THE STORM PREDICTION CENTER HAS INDICATED A MARGINAL SEVERE RISK
FOR KCDS WITH LARGE HAIL THE MAIN CONCERN. BUT THE INITIAL PROBLEM
WILL BE A RISK FOR LIFR CEILINGS BY MID EVENING FOR BOTH SITES...
WHICH HAS BEEN EXPLICITLY MENTIONED. CANNOT RULE OUT GOING DOWN
HARD ON VISIBILITY FROM DENSE FOG AS WELL THOUGH CONFIDENCE NOT AS
HIGH. MENTION OF LIGHT FOG ONLY FOR NOW. STRATUS LAYER CURRENTLY
OVER KCDS APPEARS STARTING NOW TO BE SLOWLY ERODING FROM THE WEST
AND SOUTHWEST AS A HIGH LEVEL IMPULSE AND THICKER CLOUDS ALOFT
CLEAR AWAY. EXPECT IMPROVEMENT AT KCDS WITHIN THE NEXT HOUR OR TWO
BEFORE RETURNING BY MID-EVENING. RMCQUEEN
&&
.PREV DISCUSSION... /ISSUED 931 AM CST FRI NOV 21 2014/
UPDATE...
MID MORNING UPDATE FOR MORE EXTENSIVE CLOUD COVER AND ALSO
PERSISTENT FOG IN PARTS OF ROLLING PLAINS. RMCQUEEN
AVIATION...
KCDS HAS GONE DOWN HARD IN THE PAST HALF HOUR AS STRATUS LAYER HAS
MOVED IN. LATEST HRRR AND RAP SHORT TERM GUIDANCE INDICATE GOOD
CHANCE THIS WILL BE PERSISTENT LATE INTO THE MORNING. STRATUS
LAYER SOUTH OF KLBB...MEANTIME...HAS NOT MADE IT FAR ENOUGH NORTH
AND WE HAVE AMENDED KLBB TO REMOVE MENTION. RMCQUEEN
PREV DISCUSSION... /ISSUED 525 AM CST FRI NOV 21 2014/
AVIATION...
MVFR FOG AND IFR CLOUD DECKS WERE NOTED EAST OF KCDS EARLY THIS
MORNING...AND SLOWLY NEARING THE TAF SITE. SOME COMPUTER MODELS
ARE PESSIMISTIC IN THIS ACTIVITY MAKING IT TO KCDS GIVE A
NORTHWEST WIND HAS BECOME ESTABLISHED. HOWEVER...CURRENT TRENDS MAY
SEE OTHERWISE. HAVE THEREFORE INSERTED A SCT BELOW 1000 FT AGL DECK
AND MVFR FOG UNTIL LATE MORNING. LOW CLOUDS WELL SOUTH OF KLBB
GRADUALLY MOVING NORTHEAST VALIDATES AN INSERTION OF A FEW IFR DECK.
WILL OF COURSE AMEND AS NECESSARY. OTHERWISE...LIGHT AND VARIABLE
NORTH WINDS WILL VEER TO THE SOUTHEAST THIS AFTN. INCREASING VFR
DECKS WILL PASS OVERHEAD TOWARDS THE EVENING HOURS WHILE AN
APPROACHING UPPER LEVEL DISTURBANCE AIDS IN THE DEVELOPMENT OF
-TSRA. ONCE AGAIN...KCDS IS MOST FAVORED FOR STORM CHANCES AND HAVE
INSERTED A TEMPO COMMENCING LATE TONIGHT/EARLY TOMORROW MORNING.
COMPUTER MODELS HINT AT MVFR CLOUD DECKS MAKING A RETURN TOMORROW
EVENING.
PREV DISCUSSION... /ISSUED 245 AM CST FRI NOV 21 2014/
SHORT TERM...
A WEAK EMBEDDED DISTURBANCE IN THE NEAR ZONAL FLOW ALOFT...PASSED
ACROSS THE SOUTHERN PLAINS YESTERDAY AFTN/EVENING...THUS RESULTING
IN A NRLY WIND SHIFT WHICH PREVAILED EARLY THIS MORNING. AN AREA OF
STRATUS AND FOGGY CONDITIONS WERE NOTED ACROSS ERN TEXAS THIS
MORNING...AND COULD APPROACH THE FAR ROLLING PLAINS AOA SUNRISE AS
HINTED AT BY MODEL SOLUTIONS. HOWEVER IT MAY BE HARD-PRESSED TO
AFFECT THE SAID AREA GIVEN PROGGED SFC WINDS BACKING TO THE NW WHICH
IS NOT A FAVORABLE WIND COMPONENT THAT ENCOURAGES THE INCREASE OF
LOW LEVEL MOISTURE. NONETHELESS...WOULD NOT BE SURPRISED IF A FEW
LOCALES ACROSS THE FAR ROLLING PLAINS EXPERIENCE FOG AND/OR LOW
CLOUDS BEFORE IT SCOURS OUT BY MID-LATE MORNING. WILL THEREFORE
MAINTAIN A FOG MENTION ACROSS THE ROLLING PLAINS WITH THIS FORECAST
PACKAGE.
ATTENTION QUICKLY TURNS TO AN UA LOW THAT IS TRANSLATING ESE ACROSS
CNTRL/SRN CALI PER 08Z WATER VAPOR IMAGERY. FORECAST SOLUTIONS TRACK
THE DISTURBANCE ACROSS THE NRN BAJA THIS AFN...TO NWRN OLD MEXICO
BY THE END OF THE SHORT TERM PERIOD. MEANWHILE...THE WEAK SFC
BOUNDARY WILL HAVE WASHED OUT AND SFC WINDS WILL VEER TO THE S-SE
THUS AIDING IN TRANSPORTING GULF MOISTURE ACROSS THE REGION. IT IS
NO WONDER THAT PROGGED PWATS INCREASE TO 0.5 INCH-1.20 INCHES BY
TONIGHT...WITH HIGHEST PWATS OCCURRING OFF THE CAPROCK. AS THE
SYSTEM DRAWS NEAR TONIGHT...UL SUPPORT WILL BE ON THE INCREASE
ESPECIALLY OFF THE CAPROCK...AND THE LLJ WILL CRANK UP TO 25-35
KTS ACROSS THE SAID AREA. AN APPROACHING DISTURBANCE COUPLED WITH
A MOISTENING ATMOSPHERE AND AN INCREASING LLJ WILL RESULT IN
THUNDERSTORM CHANCES COMMENCING LATE THIS EVENING INTO
TONIGHT...WITH HIGHEST POPS OFF THE CAPROCK. AS PWATS RISE ABOVE
1.00 INCH...WILL NEED TO BE ON THE LOOK OUT FOR PERIODS OF
MODERATE-HEAVY RAINFALL. FURTHERMORE...CAN NOT OVERLOOK PROGGED
MID-LEVEL CAPE VALUES OF 1.0-1.5 KJ/KG...0-6 KM BULK SHEAR VALUES
AOA 40 KTS AND VEERING WIND PROFILES NOTED FOR AREAS OFF THE
CAPROCK...THUS SUGGESTING STORMS HAVING THE CAPABILITY OF
APPROACHING STRONG LEVELS WITH HAIL BEING THE PRIMARY THREAT.
THE APPROACHING UA LOW WILL CAUSE LOWERING 500 MB HEIGHT FIELDS AND
HENCE SLIGHTLY COOLER DAYTIME TEMPS...THOUGH STILL NEAR SEASONAL
NORMS /LOWER TO MIDDLE 60S/. OVERNIGHT LOWS WILL RANGE FROM THE
UPPER 30S ACROSS THE FAR SW TX PANHANDLE TO THE LOWER 50S ACROSS THE
LOW ROLLING PLAINS.
LONG TERM...
SHOWERS AND THUNDERSTORMS LIKELY ONGOING AT THE BEGINNING OF
SATURDAY PER THE DISCUSSION ABOVE. MAJORITY OF THE MODEL SOLUTIONS
KEEP AN OPEN AND PROGRESSIVE WAVE MOVING ACROSS WEST TEXAS WHICH
WILL CONTINUE TO FAVOR THE ROLLING PLAINS FOR PRECIPITATION
SATURDAY MORNING AND A POSSIBILITY OF SHOWERS LINGERING INTO THE
AFTN HOURS THERE. PREVIOUS FCST HANDLES WELL WITH ONLY SOME MINOR
MODIFICATION TO THE PRECIP RELATED FIELDS.
HEIGHT GRADIENT PROGGED TO TIGHTEN BEHIND THE DEPARTING UPPER
TROUGH AND AHEAD OF A LOW-AMPLITUDE TROUGH MOVING SEWD ACROSS THE
ROCKIES SATURDAY NIGHT. AS THAT WAVE MOVES CLOSER TO THE AREA
SUNDAY...PROGGED 700MB HEIGHTS AND WIND SPEEDS SUGGEST A PERIOD OF
WINDY CONDITIONS DURING THE MORNING AND POSSIBLY INTO THE
AFTERNOON HOURS FAVORING THE SWRN THIRD OF THE FCST AREA.
INCREASING MID LEVEL CLOUD COVER AHEAD OF THE WAVE AND A FRONT
MOVING INTO THE FCST AREA ARE EXPECTED TO LIMIT WIND SPEEDS BELOW
ADVISORY LEVELS.
REMAINDER OF THE FCST PERIOD LOOKS FAIRLY QUIET WITH THE SRN HIGH
PLAINS UNDERNEATH NWLY FLOW ALOFT AS A RIDGE WILL BE ANCHORED
ACROSS THE WRN CONUS AND A TROUGH TO THE EAST. MODELS SEEM TO BE
CONVERGING ON A SOLUTION OF THE RIDGE BEGINNING TO SHIFT EAST
TOWARD THE PLAINS AND COLD AIR SPILLING INTO MUCH OF THE ERN CONUS
WITH THE POSSIBILITY OF SOME OF THAT COLD AIR BACKING INTO THE
AREA BRIEFLY AROUND THURSDAY. THIS IS TRENDING AWAY FROM A MORE
PRONOUNCED COLD AIR MASS MOVING INTO THE AREA PER SOME PREVIOUS
RUNS...MOST NOTABLY THE ECMWF.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 64 38 66 36 54 / 0 10 10 0 10
TULIA 63 41 66 38 57 / 0 20 20 10 10
PLAINVIEW 63 43 66 39 59 / 0 20 20 10 0
LEVELLAND 64 43 66 40 61 / 0 30 20 10 0
LUBBOCK 65 45 66 41 62 / 0 30 30 10 0
DENVER CITY 67 45 66 43 65 / 0 30 20 10 0
BROWNFIELD 65 45 66 42 63 / 0 30 30 10 0
CHILDRESS 60 46 64 43 64 / 0 60 60 10 0
SPUR 64 46 66 43 65 / 0 60 60 10 0
ASPERMONT 64 50 67 47 69 / 10 80 80 10 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
99/99/05
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
931 AM CST FRI NOV 21 2014
.UPDATE...
MID MORNING UPDATE FOR MORE EXTENSIVE CLOUD COVER AND ALSO
PERSISTENT FOG IN PARTS OF ROLLING PLAINS. RMCQUEEN
&&
.AVIATION...
KCDS HAS GONE DOWN HARD IN THE PAST HALF HOUR AS STRATUS LAYER HAS
MOVED IN. LATEST HRRR AND RAP SHORT TERM GUIDANCE INDICATE GOOD
CHANCE THIS WILL BE PERSISTENT LATE INTO THE MORNING. STRATUS
LAYER SOUTH OF KLBB...MEANTIME...HAS NOT MADE IT FAR ENOUGH NORTH
AND WE HAVE AMENDED KLBB TO REMOVE MENTION. RMCQUEEN
&&
.PREV DISCUSSION... /ISSUED 525 AM CST FRI NOV 21 2014/
AVIATION...
MVFR FOG AND IFR CLOUD DECKS WERE NOTED EAST OF KCDS EARLY THIS
MORNING...AND SLOWLY NEARING THE TAF SITE. SOME COMPUTER MODELS
ARE PESSIMISTIC IN THIS ACTIVITY MAKING IT TO KCDS GIVE A
NORTHWEST WIND HAS BECOME ESTABLISHED. HOWEVER...CURRENT TRENDS MAY
SEE OTHERWISE. HAVE THEREFORE INSERTED A SCT BELOW 1000 FT AGL DECK
AND MVFR FOG UNTIL LATE MORNING. LOW CLOUDS WELL SOUTH OF KLBB
GRADUALLY MOVING NORTHEAST VALIDATES AN INSERTION OF A FEW IFR DECK.
WILL OF COURSE AMEND AS NECESSARY. OTHERWISE...LIGHT AND VARIABLE
NORTH WINDS WILL VEER TO THE SOUTHEAST THIS AFTN. INCREASING VFR
DECKS WILL PASS OVERHEAD TOWARDS THE EVENING HOURS WHILE AN
APPROACHING UPPER LEVEL DISTURBANCE AIDS IN THE DEVELOPMENT OF
-TSRA. ONCE AGAIN...KCDS IS MOST FAVORED FOR STORM CHANCES AND HAVE
INSERTED A TEMPO COMMENCING LATE TONIGHT/EARLY TOMORROW MORNING.
COMPUTER MODELS HINT AT MVFR CLOUD DECKS MAKING A RETURN TOMORROW
EVENING.
PREV DISCUSSION... /ISSUED 245 AM CST FRI NOV 21 2014/
SHORT TERM...
A WEAK EMBEDDED DISTURBANCE IN THE NEAR ZONAL FLOW ALOFT...PASSED
ACROSS THE SOUTHERN PLAINS YESTERDAY AFTN/EVENING...THUS RESULTING
IN A NRLY WIND SHIFT WHICH PREVAILED EARLY THIS MORNING. AN AREA OF
STRATUS AND FOGGY CONDITIONS WERE NOTED ACROSS ERN TEXAS THIS
MORNING...AND COULD APPROACH THE FAR ROLLING PLAINS AOA SUNRISE AS
HINTED AT BY MODEL SOLUTIONS. HOWEVER IT MAY BE HARD-PRESSED TO
AFFECT THE SAID AREA GIVEN PROGGED SFC WINDS BACKING TO THE NW WHICH
IS NOT A FAVORABLE WIND COMPONENT THAT ENCOURAGES THE INCREASE OF
LOW LEVEL MOISTURE. NONETHELESS...WOULD NOT BE SURPRISED IF A FEW
LOCALES ACROSS THE FAR ROLLING PLAINS EXPERIENCE FOG AND/OR LOW
CLOUDS BEFORE IT SCOURS OUT BY MID-LATE MORNING. WILL THEREFORE
MAINTAIN A FOG MENTION ACROSS THE ROLLING PLAINS WITH THIS FORECAST
PACKAGE.
ATTENTION QUICKLY TURNS TO AN UA LOW THAT IS TRANSLATING ESE ACROSS
CNTRL/SRN CALI PER 08Z WATER VAPOR IMAGERY. FORECAST SOLUTIONS TRACK
THE DISTURBANCE ACROSS THE NRN BAJA THIS AFN...TO NWRN OLD MEXICO
BY THE END OF THE SHORT TERM PERIOD. MEANWHILE...THE WEAK SFC
BOUNDARY WILL HAVE WASHED OUT AND SFC WINDS WILL VEER TO THE S-SE
THUS AIDING IN TRANSPORTING GULF MOISTURE ACROSS THE REGION. IT IS
NO WONDER THAT PROGGED PWATS INCREASE TO 0.5 INCH-1.20 INCHES BY
TONIGHT...WITH HIGHEST PWATS OCCURRING OFF THE CAPROCK. AS THE
SYSTEM DRAWS NEAR TONIGHT...UL SUPPORT WILL BE ON THE INCREASE
ESPECIALLY OFF THE CAPROCK...AND THE LLJ WILL CRANK UP TO 25-35
KTS ACROSS THE SAID AREA. AN APPROACHING DISTURBANCE COUPLED WITH
A MOISTENING ATMOSPHERE AND AN INCREASING LLJ WILL RESULT IN
THUNDERSTORM CHANCES COMMENCING LATE THIS EVENING INTO
TONIGHT...WITH HIGHEST POPS OFF THE CAPROCK. AS PWATS RISE ABOVE
1.00 INCH...WILL NEED TO BE ON THE LOOK OUT FOR PERIODS OF
MODERATE-HEAVY RAINFALL. FURTHERMORE...CAN NOT OVERLOOK PROGGED
MID-LEVEL CAPE VALUES OF 1.0-1.5 KJ/KG...0-6 KM BULK SHEAR VALUES
AOA 40 KTS AND VEERING WIND PROFILES NOTED FOR AREAS OFF THE
CAPROCK...THUS SUGGESTING STORMS HAVING THE CAPABILITY OF
APPROACHING STRONG LEVELS WITH HAIL BEING THE PRIMARY THREAT.
THE APPROACHING UA LOW WILL CAUSE LOWERING 500 MB HEIGHT FIELDS AND
HENCE SLIGHTLY COOLER DAYTIME TEMPS...THOUGH STILL NEAR SEASONAL
NORMS /LOWER TO MIDDLE 60S/. OVERNIGHT LOWS WILL RANGE FROM THE
UPPER 30S ACROSS THE FAR SW TX PANHANDLE TO THE LOWER 50S ACROSS THE
LOW ROLLING PLAINS.
LONG TERM...
SHOWERS AND THUNDERSTORMS LIKELY ONGOING AT THE BEGINNING OF
SATURDAY PER THE DISCUSSION ABOVE. MAJORITY OF THE MODEL SOLUTIONS
KEEP AN OPEN AND PROGRESSIVE WAVE MOVING ACROSS WEST TEXAS WHICH
WILL CONTINUE TO FAVOR THE ROLLING PLAINS FOR PRECIPITATION
SATURDAY MORNING AND A POSSIBILITY OF SHOWERS LINGERING INTO THE
AFTN HOURS THERE. PREVIOUS FCST HANDLES WELL WITH ONLY SOME MINOR
MODIFICATION TO THE PRECIP RELATED FIELDS.
HEIGHT GRADIENT PROGGED TO TIGHTEN BEHIND THE DEPARTING UPPER
TROUGH AND AHEAD OF A LOW-AMPLITUDE TROUGH MOVING SEWD ACROSS THE
ROCKIES SATURDAY NIGHT. AS THAT WAVE MOVES CLOSER TO THE AREA
SUNDAY...PROGGED 700MB HEIGHTS AND WIND SPEEDS SUGGEST A PERIOD OF
WINDY CONDITIONS DURING THE MORNING AND POSSIBLY INTO THE
AFTERNOON HOURS FAVORING THE SWRN THIRD OF THE FCST AREA.
INCREASING MID LEVEL CLOUD COVER AHEAD OF THE WAVE AND A FRONT
MOVING INTO THE FCST AREA ARE EXPECTED TO LIMIT WIND SPEEDS BELOW
ADVISORY LEVELS.
REMAINDER OF THE FCST PERIOD LOOKS FAIRLY QUIET WITH THE SRN HIGH
PLAINS UNDERNEATH NWLY FLOW ALOFT AS A RIDGE WILL BE ANCHORED
ACROSS THE WRN CONUS AND A TROUGH TO THE EAST. MODELS SEEM TO BE
CONVERGING ON A SOLUTION OF THE RIDGE BEGINNING TO SHIFT EAST
TOWARD THE PLAINS AND COLD AIR SPILLING INTO MUCH OF THE ERN CONUS
WITH THE POSSIBILITY OF SOME OF THAT COLD AIR BACKING INTO THE
AREA BRIEFLY AROUND THURSDAY. THIS IS TRENDING AWAY FROM A MORE
PRONOUNCED COLD AIR MASS MOVING INTO THE AREA PER SOME PREVIOUS
RUNS...MOST NOTABLY THE ECMWF.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 64 38 66 36 54 / 0 10 10 0 10
TULIA 63 41 66 38 57 / 0 20 20 10 10
PLAINVIEW 63 43 66 39 59 / 0 20 20 10 0
LEVELLAND 64 43 66 40 61 / 0 30 20 10 0
LUBBOCK 65 45 66 41 62 / 0 30 30 10 0
DENVER CITY 67 45 66 43 65 / 0 30 20 10 0
BROWNFIELD 65 45 66 42 63 / 0 30 30 10 0
CHILDRESS 60 46 64 43 64 / 0 60 60 10 0
SPUR 64 46 66 43 65 / 0 60 60 10 0
ASPERMONT 64 50 67 47 69 / 10 80 80 10 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
05/99/05
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
836 PM CST SAT NOV 22 2014
.UPDATE...
THE MAIN UPDATE THIS EVENING WAS TO LOWER POPS FOR THIS EVENING
INTO THE OVERNIGHT. BUT...LEFT THE HIGHER POPS TOWARD MORNING
ALONE. THE MOISTURE AND LOW LEVEL FLOW AHEAD OF THE APPROACHING
TROF OUT WEST...COUPLED WITH A MID LEVEL RIDGE MOVING OFF SHOULD
SUPPORT LIGHT PRECIP MOVING INTO THE AREA...MAYBE JUST A DRIZZLE
OUTBREAK. THERE JUST ISN/T MUCH SUPPORT FOR BETTER PRECIP
INTENSITIES. BASED ON SOUNDINGS AND SATELLITE IMAGERY RIGHT NOW...
THE MOISTURE IS LIMITED TO THE SURFACE UP TO 4KFT OR SO...BUT IT
DEEPENS TOWARD SUNRISE.
TEMPS HAVE BEEN RISING SLOWLY SINCE THIS AFTERNOON AND WILL
GENERALLY HOLD STEADY IN THE MID OR UPPER 40S THROUGH THE NIGHT.
DEWPOINTS ARE HIGH AS WELL AND THERE IS CONCERN FOR DENSE FOG. BUT
WINDS ARE BLOWING 20-30KTS JUST OFF THE DECK SO THIS SHOULD HELP
TO KEEP THE VISIBILITIES IN CHECK.
STILL LOOKS LIKE THE MAIN RAIN EVENT WILL BEGIN BY MID DAY SUNDAY
AND CONTINUE THROUGH THE NIGHT.
&&
.AVIATION/06Z TAFS/...
IFR CONDITIONS SHOULD BE WIDESPREAD ACROSS SOUTHERN WISCONSIN
THROUGH MUCH OF THE TAF PERIOD. THERE IS UNCERTAINTY FOR THE FAR
SOUTHEAST...SPECIFICALLY KMKE/KENW TAF SITES...WHERE SOME DRIER
AIR AND MIXING MAY KEEP CIGS BOUNCING BETWEEN IFR/MVFR TONIGHT
INTO SUNDAY MORNING. EVENTUALLY AS LOW PRESSURE APPROACHES FROM
THE SOUTH BY SUNDAY AFTERNOON...EVEN THESE TWO SITES WILL DROP TO
IFR LEVELS. WE MAY EVEN SEE LIFR CONDITIONS SUNDAY AFTERNOON INTO
SUNDAY EVENING.
TEMPERATURES WILL REMAIN WELL ABOVE FREEZING DURING THIS TAF CYCLE
SO NO WINTRY MIX OR ICING IS A CONCERN.
&&
.MARINE...WILL POST A SMALL CRAFT ADVISORY FROM LATE TONIGHT
THROUGH EARLY SUNDAY EVENING FOR BRISK SOUTHERLY WINDS AHEAD OF AN
APPROACHING LOW PRESSURE SYSTEM. THEN THE MAIN CONCERN WILL BE
ONCE THE LOW STRENGTHENS AND LIFTS NORTH OF THE AREA MONDAY INTO
MONDAY EVENING. RATHER GUSTY WEST WINDS DEVELOP AND BUFKIT
SOUNDINGS SUPPORT SOME GALE CONDITIONS IN THIS REGIME. SO HAVE
HOISTED A GALE WATCH FROM MID MORNING MONDAY THOUGH MIDNIGHT
MONDAY NIGHT. HIGHEST WAVES TOWARDS OPEN WATERS.
&&
.PREV DISCUSSION... /ISSUED 324 PM CST SAT NOV 22 2014/
SHORT TERM...
TONIGHT...FORECAST CONFIDENCE MEDIUM.
MAIN CONCERN WILL BE ON TIMING OF PRECIP AND HANDLING FOG TRENDS.
MILD AND MOIST FLOW WILL PERSIST ALL NIGHT. ISODROSOTHERM ANALYSIS
SHOWS THE MOIST AXIS POINTING RIGHT INTO SRN WI WITH A GRADUAL
ADVECTION PATTERN NOTED. MID LEVEL ACROSS HERE IS ZONAL WITH THE
MAIN UPPER LOW WELL SOUTH IN TX. LOWS WILL BE ESTABLISHED EARLY
THIS EVENING WITH POSITIVE TEMP ADVECTION LIKELY FOR MUCH OF THE
NIGHT. GUIDANCE HAS BEEN SENDING MIXED SIGNALS ON HOW DENSE FOG
GETS TONIGHT. WINDS INCREASE OFF THE DECK AND THAT MAY LIMIT
THINGS FROM GETTING OUT OF HAND IN A WIDESPREAD FASHION.
NEVERTHELESS EXPECT IT TO REMAIN FOGGY BUT WILL ELECT TO NOT ISSUE
A HEADLINE AT THIS TIME. OVERALL LOOKS CLOUDY...MILD...FOGGY WITH
SOME DRIZZLE AND PERHAPS A FEW SHOWERS. LATEST HRRR BRINGS A BAND
OF SHRA THROUGH HERE IN THE 03-07Z RANGE BUT THEN NOT MUCH AFTER
THAT THROUGH 12Z.
SUNDAY...FORECAST CONFIDENCE MEDIUM.
GRADUAL PROGRESSION AND AMPLIFICATION OF WESTERN TROUGH. THIS
KEEPS SRN WI IN A BROAD SSW UPPER FLOW. SHORTWAVE ACTION IN THIS
FLOW INCREASES ESP AFTER 18Z. WILL HAVE DEFINITE POPS. THERMAL
PROFILE SUPPORTS RAIN CWA WIDE. CLOUDS/RAIN WILL LIMIT TEMPS BUT
STILL EXPECT ENOUGH TEMP ADVECTION TO REACH AT LEAST THE LOW 50S
IN MANY LOCALES.
SUNDAY NIGHT THROUGH TUESDAY...FORECAST CONFIDENCE MEDIUM.
STRONG CYCLOGENESIS IS EXPECTED FROM SW IL TO FAR ERN UPPER MI...AS
A SHORTWAVE TROUGH MOVES NORTH THROUGH THE GREAT LAKES AND A LARGER
SCALE UPPER TROUGH APPROACHES FROM THE PLAINS. A CONSENSUS OF
MODELS DEEPEN THE LOW TO 980 MB BY 12Z MON OVER FAR ERN UPPER MI
AND TAKE IT TO THE ONTARIO AND QUEBEC BORDER BY 00Z TUE. THE UPPER
WAVE AND WARM CONVEYOR BELT WILL BRING PWS OF ONE INCH AND
WIDESPREAD MDT RAINFALL SUN NT. RAINFALL FORECAST FOR SUN AFT
THROUGH THE NIGHT IS AROUND 1 INCH. 850-700 MB FRONTOGENESIS WILL
BE ON THE TRAILING END OF THE SYSTEM FOR MON AND MON NT AS THE
LARGE UPPER TROUGH SLOWLY MOVES ACROSS THE AREA. THUS EXPECT SOME
LIGHT SNOW ACCUM AS THE CHANGE TO SNOW OCCURS FROM WEST TO EAST
MON AM AND THE SNOW CONTINUES MON NT. ANY LINGERING LGT SNOW WILL
COME TO AN END TUE AM WITH POLAR HIGH PRESSURE BUILDING INTO WI
FOR THE AFT AND NIGHT. SFC TEMPS TO DROP THROUGHOUT THE DAY ON
MON ON BRISK WLY WINDS AND COLD ADVECTION. WELL BELOW NORMAL TEMPS
THEN RETURN FOR THE NEW WEEK.
LONG TERM...WEDNESDAY THROUGH SATURDAY...FORECAST CONFIDENCE
MEDIUM.
A COUPLE SHORTWAVE TROUGHS WILL DIG SEWD FROM CANADA INTO THE
REGION FOR WED-THU AND ESTABLISH NW FLOW ALOFT FOR THE REMAINDER
OF THE WEEK. SFC LOW PRESSURE AND CHANCES OF LIGHT SNOW WILL
ACCOMPANY THE UPPER WAVES BUT THE TIMING IS UNCERTAIN. LIGHT SNOW
ACCUM IS LIKELY HOWEVER. VERY COLD TEMPS WILL CONTINUE DURING THIS
PERIOD.
AVIATION/00Z TAFS/...MAIN CONCERN WILL BE STRATUS/FOG TRENDS WITHIN
THE MILD AND MOIST REGIME THAT LASTS RIGHT INTO SUNDAY. PLENTY OF
WIND TAKES SHAPE UPSTAIRS WHICH RESULTS IN SOME LLWS CONDITIONS
OVERNIGHT. ATTM BELIEVE THIS WILL KEEP THE FOG FROM GETTING
PERSISTENTLY DENSE. BUT WILL HAVE SOME DENSE FOG POCKETS ACROSS THE
CWA...BUT CONFIDENCE LOW ON WIDESPREAD AT THIS TIME. LIFR CEILINGS
WILL PERSIST INTO SUNDAY AS RAIN BECOMES WIDESPREAD. THIS MAY HELP
TO FURTHER MIX VSBYS A BIT BUT STILL EXPECT IFR VSBYS WITH A FEW
LIFR VSBYS IN ANY DENSE FOG POCKETS.
MARINE...STILL LOOKING AT POTENTIAL FOR SOME HIGHER WAVES OFFSHORE
FROM SHEBOYGAN TOWARDS OPEN WATERS...SO WILL LET THE SMALL CRAFT GO
TIL THE 00Z END TIME THERE. NEXT CONCERN WILL BE INCREASING WINDS
FOR SUNDAY AND SUNDAY EVENING. APPEARS BORDERLINE SMALL CRAFT ATTM
AS SURFACE LOW MOVES INTO SRN IL BY 00Z. A SSE WIND DEVELOPS BUT
EXPECT WAVES/WINDS TO REMAIN JUST BELOW CRITERIA. MAIN CONCERN WILL
BE ONCE THE LOW STRENGTHENS AND LIFTS NORTH OF THE AREA MONDAY INTO
MONDAY EVENING. RATHER GUSTY WEST WINDS DEVELOP AND BUFKIT SOUNDINGS
SUPPORT SOME GALE CONDITIONS IN THIS REGIME. SO HAVE HOISTED A GALE
WATCH FROM MID MORNING MONDAY THOUGH MIDNIGHT MONDAY NIGHT. HIGHEST
WAVES TOWARDS OPEN WATERS.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...GALE WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING FOR
LMZ643>646.
SMALL CRAFT ADVISORY FROM 4 AM TO 7 PM CST SUNDAY FOR LMZ643>646.
&&
$$
UPDATE...DAVIS
TONIGHT/SUNDAY AND AVIATION/MARINE...COLLAR
SUNDAY NIGHT THROUGH SATURDAY...GEHRING
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
815 PM CST SAT NOV 22 2014
.UPDATED...
815 PM CST SAT NOV 22 2014
FOG HAS CONTINUED TO THICKEN - MOSTLY NORTH OF I-90 AT MID EVENING.
CALLS TO AREA DISPATCHES IN THESE LOCATIONS HAVE INDICATED DENSE FOG
WITH 1/4 MILE VSBYS. HAVE EXPANDED THE DENSE FOG ADVISORY SOUTHWARD
AS AS RESULT. HAVE ALSO EXTENDED IN TIME...UNTIL 8 AM...PER
COORDINATION WITH SOME SURROUNDING OFFICES.
JUST HOW WIDESPREAD THE DENSE FOG WILL BECOME IS NOT CLEAR.
NORTHWARD ADVANCING STRATUS LAYER OVER IA HAS RESULTED IN
IMPROVEMENT IN VISIBILITIES AS IT MOVED IN. TEMPERATURES WERE
WARMING AND DEW POINTS WERE CHASING THEM.
FOR NOW...WILL EXPAND ADVISORY AS NEEDED...PER SFC OBS AND LAW
ENFORCMENT CONTACTS.
EXPECTING SOME DRIZZLE TO DEVELOP LATER TONIGHT TOO...WITH
ISENTROPIC UPGLIDE AND SOME OMEGA IN THIS LOW CLOUD LAYER.
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 313 PM CST SAT NOV 22 2014
CURRENTLY AS OF 21Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED A POWERFUL TROUGH OVER THE PACIFIC NORTHWEST...NOTED
BY A 155 KT JET NEAR 300MB ON THE 12Z MEDFORD OREGON RAOB. OTHER
FEATURES OF NOTE WERE AN UPPER LOW OVER THE BIG BEND REGION OF TEXAS
AND AN UPPER RIDGE OVER THE DAKOTAS AND MN. BELOW THE UPPER
RIDGE...WEST TO SOUTHWEST WINDS OF 20-30 KT FROM 925-850MB PER
PROFILER/VWP DATA HAS BEEN ADVECTING WARMER AIR INTO THE REGION.
925MB TEMPS HAVE RISEN FROM -1 TO 2C AT 12Z TO 2-6C AT 21Z.
HOWEVER...TAMDAR SOUNDINGS SHOW MUCH OF THIS WARMING HAS BEEN
STRENGTHENING A STRONG LOW LEVEL INVERSION...TRAPPING MOISTURE
ADVECTING NORTHWARD ON SOUTHERLY WINDS. DEWPOINTS PRESENTLY RANGE IN
THE 30S TO LOW 40S ACROSS THE FORECAST AREA...BUT 40S TO MID 50S
WERE LURKING ACROSS CENTRAL AND SOUTHERN IOWA. THE INCREASED
WARMING AND MOISTURE AT THE SURFACE HAS ALSO ALLOWED THE SNOWPACK TO
BEGIN TO WARM AND MELT...ADDING ADDITIONAL MOISTURE. WE HAVE SEEN
DENSE FOG EARLIER IN THE DAY...BUT DAYTIME MIXING PLUS WARMER AIR
COMING UP FROM THE SOUTH HAS HELPED TO RAISE VISIBILITIES FOR NOW.
FOR TONIGHT...IMPRESSIVE SURFACE TO 925MB WARM AND MOIST AIR
ADVECTION REMAINS PROGGED TO OCCUR ACROSS THE FORECAST AREA...AIDED
BY THE 925MB WINDS INCREASING TO 30-40 KT. 925MB TEMPS AND
DEWPOINTS BY 12Z SUNDAY CLIMB TO 8-10C...WITH MUCH OF THE JUMP
HAPPENING BETWEEN 00-06Z. THESE DEWPOINTS ARE 2-3 STANDARD
DEVIATIONS ABOVE NORMAL. HAD TO DO SOME MAJOR TEMP/DEWPOINT
ADJUSTMENTS TO HANDLE THIS WARM/MOIST AIR ADVECTION...FOLLOWING
MORE OF THE ECMWF/CANADIAN WHICH ARE NOT AFFECTED AS MUCH BY
SNOWPACK LIKE THE NAM IS. WITH ALL OF THIS WARMING AND MOISTURE
COMING ACROSS THE SNOWPACK...ANTICIPATE FAIRLY RAPID MELTING...
THROWING MORE MOISTURE INTO THE BOUNDARY LAYER. GIVEN AN
INVERSION HOLDING IN PLACE BETWEEN 850-900MB THIS EVENING...BELIEVE
WE SHOULD GET MORE FOG TO DEVELOP...POSSIBLY DENSE...SIMILAR TO WHAT
IS GOING ON RIGHT NOW IN SOUTH CENTRAL IA ON I-35 ON THE NOSE OF
THE MOISTURE SURGE. CONSIDERED GOING WITH AN ADVISORY...BUT
AFTERNOON TRENDS HAS REDUCED CONFIDENCE. ADVISORIES ARE STILL
POSSIBLE...THOUGH. OVERNIGHT...ALL THE FOG COULD DISSIPATE AS
THAT INVERSION WEAKENS...AS INDICATED IN RAP/HIRESARW VISIBILITY
FORECASTS. IN FACT...WE SHOULD HAVE THE AIRMASS OVER MISSOURI IN
PLACE WHICH FEATURES NO VISIBILITY RESTRICTION. SINCE THERE STILL
IS SNOWPACK...HAVE KEPT SOME FOG MENTION...BUT WE MAY NOT HAVE
MUCH SNOWPACK EXCEPT IN OUR NORTH BY THE TIME 12Z ROLLS AROUND.
ALONG WITH THE FOG...THE STRONG INCREASE OF LOW LEVEL MOISTURE IS
LIKELY TO LEAD TO AREAS- WIDESPREAD DRIZZLE...ESPECIALLY
OVERNIGHT.
ON SUNDAY...GOOD MODEL CONSENSUS EXISTS FOR DEEP TROUGHING TO FORM
ACROSS THE PLAINS BY 00Z...WHICH HELPS TO PULL NORTHEASTWARD THE
UPPER LOW NEAR TEXAS INTO SOUTHERN ILLINOIS. THE 22.12Z NAM IS THE
ONLY MODEL WHICH DOESNT PULL THE UPPER LOW NORTHEASTWARD...WHICH
APPEARS TO BE AN OUTLIER AND HAS BEEN DISCOUNTED. WITH THE APPROACH
OF BOTH THE UPPER TROUGH AND LOW IN THE AFTERNOON...DPVA FOR
VERTICAL MOTION INCREASES. THIS VERTICAL MOTION COMBINED WITH
PRECIPITABLE WATER CLIMBING TO 0.75-1 INCH...HIGHEST OVER THE
SOUTHEAST HALF OF THE FORECAST AREA...WILL LEAD TO AN INCREASE IN
SHOWER ACTIVITY...ESPECIALLY IN THE AFTERNOON. NOTE THAT THERE ARE
SIGNS FOR A FRONTOGENETIC BAND TO FORM STRETCHING SOUTHWEST TO
NORTHEAST ACROSS THE FORECAST AREA...WHICH MAY LEAD TO LESS
PRECIPITATION OVER THE FAR NORTHWEST SIDE OF THE FORECAST AREA.
OTHERWISE...ANY FOG FROM TONIGHT LOOKS TO DISSIPATE WEST TO EAST
THROUGH THE AFTERNOON...IN RESPONSE TO A COLD FRONT COMING INTO THE
WESTERN FORECAST AREA AND THE RAIN MOVING IN.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 313 PM CST SAT NOV 22 2014
SUNDAY NIGHT AND MONDAY...THIS PERIOD IS BECOMING MORE INTERESTING.
THERE ARE SIGNS IN THE 22.12Z GFS AND CANADIAN OF PHASING TAKING
PLACE...BETWEEN THE OVERALL UPPER TROUGH ACROSS THE PLAINS AND THE
CURRENT STRONG JET STREAK AT MEDFORD OREGON LIFTING INTO THE OHIO
VALLEY. THE GFS EVEN TAKES IT ONCE STEP FURTHER AND PHASES IN THE
TEXAS UPPER LOW. THE RESULT OF THE PHASING IS RAPID DEEPENING OF A
SURFACE LOW BETWEEN 00-12Z MONDAY MARCHING FROM MISSOURI TO NORTHERN
LAKE MICHIGAN. PRESSURES FALL FROM THE UPPER 980S TO LOW 970S OR
UPPER 960S MB. THE 22.09Z SREF NMMB MEMBERS AND SOME OF THE
CANADIAN ENSEMBLES ARE ALSO QUITE DEEP...EVEN MORESO THAN THE
GFS/CANADIAN. THESE DEEPER MODELS WOULD RESULT IN A TROWAL
OVER THE FORECAST AREA...LEADING TO A HEAVY SNOW BAND AND STRONG
WINDS. ALTHOUGH THERE HAS BEEN A TREND OF DEEPENING IN THE
AFOREMENTIONED MODELS...THE 22.12Z ECMWF REMAINS CONSISTENT IN A
MORE PROGRESSIVE/LESS PHASED SCENARIO. THE MODEL STILL HAS SNOW FOR
THE FORECAST AREA AFTER SOME EVENING RAIN...BUT THE F-GEN BAND IS
NOT NEARLY AS IMPRESSIVE. GIVEN THE CONSISTENCY IN THE ECMWF
AND THE MODEL BEING GENERALLY ONE OF THE BEST AT SYNOPTIC
VERIFICATION...FEEL IT IS DIFFICULT TO JUMP ON THE DEEP SCENARIOS
YET. THUS...THE FORECAST FOR SUNDAY NIGHT/MONDAY REMAINS LARGELY
UNCHANGED. DID BACK OFF THE BLOWING SNOW A BIT SINCE THE SNOWPACK
WILL BE GONE...ALLOWING ANY FALLING SNOW TO ACCUMULATE IN DITCHES
AND THUS LIMIT BLOWING. TEMPERATURE WISE...EXPECT A CONTINUOUS
FALLING TREND FROM SUNDAY NIGHT THROUGH MONDAY.
SNOW SHOULD GRADUALLY TAPER OFF MONDAY NIGHT AS THE LOW LIFTS
OFF TO THE NORTHEAST...BUT CONTINUED COLD AIR ADVECTION IS
ADVERTISED. 925MB TEMPS PLUNGE TO -10 TO -12C...WHICH SHOULD BRING
TEMPS DOWN INTO THE TEENS. TUESDAY FINALLY LOOKS LIKE A DRY
DAY...ASSOCIATED WITH SURFACE RIDGING COMING ACROSS AND AHEAD OF A
POTENT SHORTWAVE DROPPING INTO THE DAKOTAS. PRECIPITABLE WATER IS
QUITE DRY TOO...AROUND 0.2 OF AN INCH...WHICH SHOULD ALLOW ANY LOW
CLOUDS TO CLEAR TUESDAY MORNING. MORE HIGH CLOUDS ARE LIKELY TO
ARRIVE IN THE AFTERNOON...THOUGH. WITH 925MB TEMPS OF -8 TO -10C AT
18Z...HIGHS ONLY LOOK TO TOP OUT IN THE 20S.
TUESDAY NIGHT AND WEDNESDAY COULD BE INTERESTING AS WELL WITH THE
22.12Z ECMWF REMAINING CONSISTENT IN DRIVING A STORM SYSTEM
FROM THE DAKOTAS THROUGH THE REGION. THE 22.12Z/18Z NAM ARE SIMILAR
TOO...THOUGH THERE REALLY IS NO RESEMBLANCE OF THE SYSTEM IN THE
22.12Z GFS. THE 22.12Z CANADIAN IS LIKE A WEAKER NAM/ECMWF. SHOULD
THE ECMWF/NAM VERIFY...WE COULD BE LOOKING AT A 1-2 INCH
SNOWFALL...WHICH COULD IMPACT THANKSGIVING TRAVEL. FOR NOW HAVE TO
KEEP THE CHANCES LOWER...20-40...UNTIL BETTER MODEL AGREEMENT OCCURS.
HOWEVER WEDNESDAY PANS OUT...GOOD MODEL AGREEMENT EXISTS FOR ANOTHER
COLD SURGE TO DIVE INTO THE REGION FOR THANKSGIVING. 925MB TEMPS OF
-14 TO -16C ARE PROGGED...WHICH WOULD RESULT IN HIGHS ONLY IN THE
MID TEENS TO LOW 20S AT BEST. THIS COLD AIR LOOKS TO LINGER INTO THE
EARLY PART OF THE WEEKEND AS CANADIAN HIGH PRESSURE BUILDS IN.
GENERALLY CONDITIONS SHOULD BE DRY...THOUGH CANNOT RULE OUT A FEW
LIGHT SNOW PERIODS THAT DO NOT ACCUMULATE UP TO MUCH.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 530 PM CST SAT NOV 22 2014
LIFR/IFR CONDITIONS LOOK TO BE PREDOMINANT TONIGHT THROUGH THE
BETTER PART OF SUNDAY. INCREASING LOW LEVEL MOISTURE TONIGHT WILL
KEEP CIGS LOW...WHILE WARMING CONTINUES TO MELT SNOW PACK AND HELPS
WITH MOISTENING OF THE BOUNDARY LAYER. CIGS SHOULD STAY SUB 1KFT.
EXPECT AREAS OF DRIZZLE TO DEVELOP LATER THIS EVENING...PERSISTING
THROUGH AT LEAST SUNDAY MORNING. FOG SHOULD REMAIN...AND COULD
BECOME DENSE AT TIMES. EXPECTING A SHIFT TO NORTHWEST WINDS WITH THE
PASSAGE OF A SFC FRONT MID/LATE SUN AFTERNOON.
ONE CAVEAT TO THE LOW CLOUDS IS LATEST SATELLITE FOG/STRATUS IMAGERY
AND SFC OBS SHOW AN AREA OF CLEARING OVER NORTHERN IA. QUESTION IS
WHETHER THIS SLOT WILL MOVE NORTHWARD TO KRST/KLSE OR STAY SOUTH.
MASS OF STRATUS JUST SOUTH OF THE SLOT...AND MAKING GOOD PROGRESS
NORTH. THIS COULD OVERTAKE THE CLEARING BEFORE IT MAKES KRST/KLSE.
FOR NOW...WILL STICK WITH KEEPING THE CLEARING SLOT SOUTH...STAYING
WITH THE LOW CLOUDS. WILL ADJUST FORECAST AS NECESSARY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...DENSE FOG ADVISORY UNTIL 8 AM CST SUNDAY FOR WIZ017-029-032>034.
MN...DENSE FOG ADVISORY UNTIL 8 AM CST SUNDAY FOR MNZ079.
IA...NONE.
&&
$$
UPDATED....RIECK
SHORT TERM...AJ
LONG TERM....AJ
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
530 PM CST SAT NOV 22 2014
.UPDATED...
530 PM CST SAT NOV 22 2014
FOG CONTINUES THICK ACROSS NORTH-CENTRAL WI...WITH CONTINUING
WARMING MELTING EXISTING SNOW PACK AND HELPING TO SATURATE THE
BOUNDARY LAYER. INCREASING WINDS WILL MOVE IN FROM THE WEST...AND
SHOULD HELP TO IMPROVE VSBYS A BIT. HAVE ISSUED A DENSE FOG ADVISORY
FOR TONIGHT FOR CLARK/TAYLOR COUNTIES IN RESPONSE TO THE THICK FOG.
MAY NEED TO CANCEL EARLY IF IMPROVEMENT IS REALIZED AND HOLDS.
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 313 PM CST SAT NOV 22 2014
CURRENTLY AS OF 21Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED A POWERFUL TROUGH OVER THE PACIFIC NORTHWEST...NOTED
BY A 155 KT JET NEAR 300MB ON THE 12Z MEDFORD OREGON RAOB. OTHER
FEATURES OF NOTE WERE AN UPPER LOW OVER THE BIG BEND REGION OF TEXAS
AND AN UPPER RIDGE OVER THE DAKOTAS AND MN. BELOW THE UPPER
RIDGE...WEST TO SOUTHWEST WINDS OF 20-30 KT FROM 925-850MB PER
PROFILER/VWP DATA HAS BEEN ADVECTING WARMER AIR INTO THE REGION.
925MB TEMPS HAVE RISEN FROM -1 TO 2C AT 12Z TO 2-6C AT 21Z.
HOWEVER...TAMDAR SOUNDINGS SHOW MUCH OF THIS WARMING HAS BEEN
STRENGTHENING A STRONG LOW LEVEL INVERSION...TRAPPING MOISTURE
ADVECTING NORTHWARD ON SOUTHERLY WINDS. DEWPOINTS PRESENTLY RANGE IN
THE 30S TO LOW 40S ACROSS THE FORECAST AREA...BUT 40S TO MID 50S
WERE LURKING ACROSS CENTRAL AND SOUTHERN IOWA. THE INCREASED
WARMING AND MOISTURE AT THE SURFACE HAS ALSO ALLOWED THE SNOWPACK TO
BEGIN TO WARM AND MELT...ADDING ADDITIONAL MOISTURE. WE HAVE SEEN
DENSE FOG EARLIER IN THE DAY...BUT DAYTIME MIXING PLUS WARMER AIR
COMING UP FROM THE SOUTH HAS HELPED TO RAISE VISIBILITIES FOR NOW.
FOR TONIGHT...IMPRESSIVE SURFACE TO 925MB WARM AND MOIST AIR
ADVECTION REMAINS PROGGED TO OCCUR ACROSS THE FORECAST AREA...AIDED
BY THE 925MB WINDS INCREASING TO 30-40 KT. 925MB TEMPS AND
DEWPOINTS BY 12Z SUNDAY CLIMB TO 8-10C...WITH MUCH OF THE JUMP
HAPPENING BETWEEN 00-06Z. THESE DEWPOINTS ARE 2-3 STANDARD
DEVIATIONS ABOVE NORMAL. HAD TO DO SOME MAJOR TEMP/DEWPOINT
ADJUSTMENTS TO HANDLE THIS WARM/MOIST AIR ADVECTION...FOLLOWING
MORE OF THE ECMWF/CANADIAN WHICH ARE NOT AFFECTED AS MUCH BY
SNOWPACK LIKE THE NAM IS. WITH ALL OF THIS WARMING AND MOISTURE
COMING ACROSS THE SNOWPACK...ANTICIPATE FAIRLY RAPID MELTING...
THROWING MORE MOISTURE INTO THE BOUNDARY LAYER. GIVEN AN
INVERSION HOLDING IN PLACE BETWEEN 850-900MB THIS EVENING...BELIEVE
WE SHOULD GET MORE FOG TO DEVELOP...POSSIBLY DENSE...SIMILAR TO WHAT
IS GOING ON RIGHT NOW IN SOUTH CENTRAL IA ON I-35 ON THE NOSE OF
THE MOISTURE SURGE. CONSIDERED GOING WITH AN ADVISORY...BUT
AFTERNOON TRENDS HAS REDUCED CONFIDENCE. ADVISORIES ARE STILL
POSSIBLE...THOUGH. OVERNIGHT...ALL THE FOG COULD DISSIPATE AS
THAT INVERSION WEAKENS...AS INDICATED IN RAP/HIRESARW VISIBILITY
FORECASTS. IN FACT...WE SHOULD HAVE THE AIRMASS OVER MISSOURI IN
PLACE WHICH FEATURES NO VISIBILITY RESTRICTION. SINCE THERE STILL
IS SNOWPACK...HAVE KEPT SOME FOG MENTION...BUT WE MAY NOT HAVE
MUCH SNOWPACK EXCEPT IN OUR NORTH BY THE TIME 12Z ROLLS AROUND.
ALONG WITH THE FOG...THE STRONG INCREASE OF LOW LEVEL MOISTURE IS
LIKELY TO LEAD TO AREAS- WIDESPREAD DRIZZLE...ESPECIALLY
OVERNIGHT.
ON SUNDAY...GOOD MODEL CONSENSUS EXISTS FOR DEEP TROUGHING TO FORM
ACROSS THE PLAINS BY 00Z...WHICH HELPS TO PULL NORTHEASTWARD THE
UPPER LOW NEAR TEXAS INTO SOUTHERN ILLINOIS. THE 22.12Z NAM IS THE
ONLY MODEL WHICH DOESNT PULL THE UPPER LOW NORTHEASTWARD...WHICH
APPEARS TO BE AN OUTLIER AND HAS BEEN DISCOUNTED. WITH THE APPROACH
OF BOTH THE UPPER TROUGH AND LOW IN THE AFTERNOON...DPVA FOR
VERTICAL MOTION INCREASES. THIS VERTICAL MOTION COMBINED WITH
PRECIPITABLE WATER CLIMBING TO 0.75-1 INCH...HIGHEST OVER THE
SOUTHEAST HALF OF THE FORECAST AREA...WILL LEAD TO AN INCREASE IN
SHOWER ACTIVITY...ESPECIALLY IN THE AFTERNOON. NOTE THAT THERE ARE
SIGNS FOR A FRONTOGENETIC BAND TO FORM STRETCHING SOUTHWEST TO
NORTHEAST ACROSS THE FORECAST AREA...WHICH MAY LEAD TO LESS
PRECIPITATION OVER THE FAR NORTHWEST SIDE OF THE FORECAST AREA.
OTHERWISE...ANY FOG FROM TONIGHT LOOKS TO DISSIPATE WEST TO EAST
THROUGH THE AFTERNOON...IN RESPONSE TO A COLD FRONT COMING INTO THE
WESTERN FORECAST AREA AND THE RAIN MOVING IN.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 313 PM CST SAT NOV 22 2014
SUNDAY NIGHT AND MONDAY...THIS PERIOD IS BECOMING MORE INTERESTING.
THERE ARE SIGNS IN THE 22.12Z GFS AND CANADIAN OF PHASING TAKING
PLACE...BETWEEN THE OVERALL UPPER TROUGH ACROSS THE PLAINS AND THE
CURRENT STRONG JET STREAK AT MEDFORD OREGON LIFTING INTO THE OHIO
VALLEY. THE GFS EVEN TAKES IT ONCE STEP FURTHER AND PHASES IN THE
TEXAS UPPER LOW. THE RESULT OF THE PHASING IS RAPID DEEPENING OF A
SURFACE LOW BETWEEN 00-12Z MONDAY MARCHING FROM MISSOURI TO NORTHERN
LAKE MICHIGAN. PRESSURES FALL FROM THE UPPER 980S TO LOW 970S OR
UPPER 960S MB. THE 22.09Z SREF NMMB MEMBERS AND SOME OF THE
CANADIAN ENSEMBLES ARE ALSO QUITE DEEP...EVEN MORESO THAN THE
GFS/CANADIAN. THESE DEEPER MODELS WOULD RESULT IN A TROWAL
OVER THE FORECAST AREA...LEADING TO A HEAVY SNOW BAND AND STRONG
WINDS. ALTHOUGH THERE HAS BEEN A TREND OF DEEPENING IN THE
AFOREMENTIONED MODELS...THE 22.12Z ECMWF REMAINS CONSISTENT IN A
MORE PROGRESSIVE/LESS PHASED SCENARIO. THE MODEL STILL HAS SNOW FOR
THE FORECAST AREA AFTER SOME EVENING RAIN...BUT THE F-GEN BAND IS
NOT NEARLY AS IMPRESSIVE. GIVEN THE CONSISTENCY IN THE ECMWF
AND THE MODEL BEING GENERALLY ONE OF THE BEST AT SYNOPTIC
VERIFICATION...FEEL IT IS DIFFICULT TO JUMP ON THE DEEP SCENARIOS
YET. THUS...THE FORECAST FOR SUNDAY NIGHT/MONDAY REMAINS LARGELY
UNCHANGED. DID BACK OFF THE BLOWING SNOW A BIT SINCE THE SNOWPACK
WILL BE GONE...ALLOWING ANY FALLING SNOW TO ACCUMULATE IN DITCHES
AND THUS LIMIT BLOWING. TEMPERATURE WISE...EXPECT A CONTINUOUS
FALLING TREND FROM SUNDAY NIGHT THROUGH MONDAY.
SNOW SHOULD GRADUALLY TAPER OFF MONDAY NIGHT AS THE LOW LIFTS
OFF TO THE NORTHEAST...BUT CONTINUED COLD AIR ADVECTION IS
ADVERTISED. 925MB TEMPS PLUNGE TO -10 TO -12C...WHICH SHOULD BRING
TEMPS DOWN INTO THE TEENS. TUESDAY FINALLY LOOKS LIKE A DRY
DAY...ASSOCIATED WITH SURFACE RIDGING COMING ACROSS AND AHEAD OF A
POTENT SHORTWAVE DROPPING INTO THE DAKOTAS. PRECIPITABLE WATER IS
QUITE DRY TOO...AROUND 0.2 OF AN INCH...WHICH SHOULD ALLOW ANY LOW
CLOUDS TO CLEAR TUESDAY MORNING. MORE HIGH CLOUDS ARE LIKELY TO
ARRIVE IN THE AFTERNOON...THOUGH. WITH 925MB TEMPS OF -8 TO -10C AT
18Z...HIGHS ONLY LOOK TO TOP OUT IN THE 20S.
TUESDAY NIGHT AND WEDNESDAY COULD BE INTERESTING AS WELL WITH THE
22.12Z ECMWF REMAINING CONSISTENT IN DRIVING A STORM SYSTEM
FROM THE DAKOTAS THROUGH THE REGION. THE 22.12Z/18Z NAM ARE SIMILAR
TOO...THOUGH THERE REALLY IS NO RESEMBLANCE OF THE SYSTEM IN THE
22.12Z GFS. THE 22.12Z CANADIAN IS LIKE A WEAKER NAM/ECMWF. SHOULD
THE ECMWF/NAM VERIFY...WE COULD BE LOOKING AT A 1-2 INCH
SNOWFALL...WHICH COULD IMPACT THANKSGIVING TRAVEL. FOR NOW HAVE TO
KEEP THE CHANCES LOWER...20-40...UNTIL BETTER MODEL AGREEMENT OCCURS.
HOWEVER WEDNESDAY PANS OUT...GOOD MODEL AGREEMENT EXISTS FOR ANOTHER
COLD SURGE TO DIVE INTO THE REGION FOR THANKSGIVING. 925MB TEMPS OF
-14 TO -16C ARE PROGGED...WHICH WOULD RESULT IN HIGHS ONLY IN THE
MID TEENS TO LOW 20S AT BEST. THIS COLD AIR LOOKS TO LINGER INTO THE
EARLY PART OF THE WEEKEND AS CANADIAN HIGH PRESSURE BUILDS IN.
GENERALLY CONDITIONS SHOULD BE DRY...THOUGH CANNOT RULE OUT A FEW
LIGHT SNOW PERIODS THAT DO NOT ACCUMULATE UP TO MUCH.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 530 PM CST SAT NOV 22 2014
LIFR/IFR CONDITIONS LOOK TO BE PREDOMINANT TONIGHT THROUGH THE
BETTER PART OF SUNDAY. INCREASING LOW LEVEL MOISTURE TONIGHT WILL
KEEP CIGS LOW...WHILE WARMING CONTINUES TO MELT SNOW PACK AND HELPS
WITH MOISTENING OF THE BOUNDARY LAYER. CIGS SHOULD STAY SUB 1KFT.
EXPECT AREAS OF DRIZZLE TO DEVELOP LATER THIS EVENING...PERSISTING
THROUGH AT LEAST SUNDAY MORNING. FOG SHOULD REMAIN...AND COULD
BECOME DENSE AT TIMES. EXPECTING A SHIFT TO NORTHWEST WINDS WITH THE
PASSAGE OF A SFC FRONT MID/LATE SUN AFTERNOON.
ONE CAVEAT TO THE LOW CLOUDS IS LATEST SATELLITE FOG/STRATUS IMAGERY
AND SFC OBS SHOW AN AREA OF CLEARING OVER NORTHERN IA. QUESTION IS
WHETHER THIS SLOT WILL MOVE NORTHWARD TO KRST/KLSE OR STAY SOUTH.
MASS OF STRATUS JUST SOUTH OF THE SLOT...AND MAKING GOOD PROGRESS
NORTH. THIS COULD OVERTAKE THE CLEARING BEFORE IT MAKES KRST/KLSE.
FOR NOW...WILL STICK WITH KEEPING THE CLEARING SLOT SOUTH...STAYING
WITH THE LOW CLOUDS. WILL ADJUST FORECAST AS NECESSARY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...DENSE FOG ADVISORY UNTIL 6 AM CST SUNDAY FOR WIZ017-029.
MN...NONE.
IA...NONE.
&&
$$
UPDATED....RIECK
SHORT TERM...AJ
LONG TERM....AJ
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1233 AM MST SUN NOV 23 2014
.UPDATE...
ISSUED AT 1233 AM MST SUN NOV 23 2014
UPDATED TO DROP WINTER WEATHER ADVISORY FOR THE EASTERN UINTA
BASIN. HEAVY SNOWFALL HAS SHIFTED TO THE SOUTHEAST WITH THE COLD
FRONT WHICH SWEPT ACROSS THE AREA DURING THE EVENING. SCATTERED
SNOWFALL WILL CONTINUE OVER PORTIONS OF THE VALLEY...HOWEVER
ADDITIONAL ACCUMULATIONS WILL BE LIGHT.
UPDATE ISSUED AT 858 PM MST SAT NOV 22 2014
A QUICK SHOT OF SNOWFALL AHEAD OF THE FRONT CAUSED A QUICK INCH OF
SNOW IN THE TOWN OF VERNAL AND SURROUNDING COMMUNITIES. DO NOT
ANTICIPATE MUCH MORE ACCUMULATION BUT DECIDED TO ISSUE ADVISORY
FOR THAT ZONE AS LOCAL DISPATCH REPORTS NUMEROUS CAR ACCIDENTS
ACROSS THE AREA. THINK IT BETTER TO GET THE WORD OUT FOR THOSE
INDIVIDUALS CONSIDERING DRIVING TONIGHT. NO OTHER CHANGES TO
CURRENT WINTER HIGHLIGHTS.
UPDATE ISSUED AT 725 PM MST SAT NOV 22 2014
THE SURFACE COLD FRONT HAS ENTERED WRN WY AND IS DRAPED DOWN TO
THE SE THROUGH CENTRAL UTAH. A FEW LIGHTNING STRIKES ARE STILL
BEING OBSERVED ALONG THE FRONT BUT THE NUMBER HAS DROPPED
DRAMATICALLY IN THE LAST FEW HOURS. THIS TREND WILL CONTINUE
THROUGH THE EVENING HOURS. THE RADAR MOSAIC SHOWS WIDESPREAD
PRECIP ACROSS THE CWA THIS EVENING WITH MANY AREAS REPORTING...OR
HAVING REPORTED...SHOWERS OVER THE LAST FEW HOURS. THIS WILL
CONTINUE AS THE FRONT APPROACHES. BOTH THE HRRR AND NAM12
INITIALIZED WELL AND BRING THE FRONT THROUGH NRN AREAS BY ABOUT
MIDNIGHT...REACHING THE GRAND VALLEY AROUND 0300L AND THEN THE SAN
JUANS BY DAYBREAK. SNOTELS REPORTING A FEW INCHES OF SNOW FOR THE
PARK/GORE RANGES WHILE ONE SNOTEL IN ERN UT REPORTING AROUND 6
INCHES. CURRENT FORECAST CAPTURING CURRENT WEATHER WELL SO MADE NO
CHANGES.
&&
.SHORT TERM...(TONIGHT THROUGH SUNDAY NIGHT)
ISSUED AT 318 PM MST SAT NOV 22 2014
SATELLITE AND ANALYSIS SHOWS THE COLD FRONT OVER NW UT AND
NORTHERN NV ASSOCIATED WITH THE STORM SYSTEM TO MOVE THROUGH THE
AREA TONIGHT. RADAR SHOWS AN AREA OF LOWER CLOUDS AND SCATTERED
SHOWERS MOVING THROUGH CENTRAL CO WITH SOME SHOWERS REPORTED ALONG
INTERSTATE 70 EAST OF GRAND JUNCTION. THE FRONT SHOULD MOVE
THROUGH NORTHWEST CO BY ABOUT MIDNIGHT AND THEN DRAG THROUGH THE
REST OF THE AREA OVERNIGHT. THE BEST COLD ADVECTION AND DYNAMIC
SUPPORT SHOULD MOVE THROUGH BETWEEN ABOUT 04Z AND 12Z. FOLLOWING
FRONTAL PASSAGE...FROM NW TO SE ACROSS THE AREA TONIGHT...WINDS AT
MTN TOP LEVEL WILL SHIFT TO THE NW AND BECOME MORE NORTHERLY WITH
TIME SUNDAY. THIS WILL SHIFT THE FOCUS OF BEST SNOWFALL FROM WEST
TO NNW FACING SLOPES.
MOISTURE STEADILY ERODES SUNDAY...AS FORECAST SOUNDINGS SHOW ONLY
A SHALLOW SURFACE-BASED SATURATED LAYER REMAINING OVER THE
NORTHERN HALF OF THE AREA. TEMPERATURES IN THIS LAYER ARE IN THE
FAVORABLE RANGE FOR DENDRITIC GROWTH WITH A STRONG LAPSE RATE. IN
THESE CONDITIONS OROGRAPHIC SNOWFALL SHOULD CONTINUE IN THE
NORTHERN AND CENTRAL MOUNTAINS...BUT DIMINISH OVER THE VALLEYS AND
PLATEAUS. THE SOUNDING OVER THE SOUTHERN HALF OF THE AREA BECOMES
EVEN DRIER SO THERE A PAUSE IN SNOWFALL SHOULD OCCUR OVER MUCH OF
THE SOUTHERN MOUNTAINS SUNDAY NIGHT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 318 PM MST SAT NOV 22 2014
MONDAY IN NW FLOW A STRONG COLD DISTURBANCE DROPS THROUGH THE
REGION. AN ASSOCIATED -33C COLD CORE STEEPENS LAPSE RATES.
MOISTURE IS LIMITED AND WITH THE JET DIGGING THROUGH UTAH
DYNAMICS ARE NOT OVERLY IMPRESSIVE. BUT COLD ADVECTION...NW
OROGRAPHICS...AND THE SNOW PRODUCTION LAYER AT MTN TOP LEVEL
(-12C AT 700MB) WILL COMBINE TO PRODUCE ANOTHER ROUND OF
SIGNIFICANT SNOWFALL OVER THE NORTHERN AND CENTRAL MTNS. THE
CURRENT HIGHLIGHTS FOR MONDAY LOOK ON TRACK...THOUGH THE NW SAN
JUAN MTNS MAY NEED AN ADVISORY. HAVE RAISED POPS THERE. THE SNOW
SHOULD BE QUITE DRY FOR NOVEMBER...IN THE 20:1 RANGE.
SNOWFALL FINALLY DIMINISHES THROUGH MONDAY NIGHT AS THE TROUGH AND
ASSOCIATED JET SLIDES SE. THE MOIST MARGINALLY UNSTABLE LAYER
SHRINKS TOP DOWN INTO TUESDAY SO SOME SCATTERED SNOW SHOWERS ARE
EXPECTED IN THE EASTERN MTNS THROUGH TUESDAY AFTERNOON WITH LITTLE
ACCUMULATION EXPECTED.
TUESDAY NIGHT THROUGH SATURDAY...THE WEST COAST RIDGE SLOWLY
PROGRESSES INLAND BRINGING DRY CONDITIONS AND PERSISTENT VALLEY
INVERSIONS. UNDERCUT GUIDANCE TEMPERATURES INTO FRIDAY AS THE
RIDGE BUILDS OVER THE FORECAST AREA AND DEAMPLIFIES. THIS PROMISES
DRY CONDITIONS FOR THANKSGIVING. SATURDAY MODEL TIMING BREAKS
SOMEWHAT WITH THE GFS DIGGING THE NEXT TROUGH INTO WA-OR WHILE THE
EC HOLDS IT OFFSHORE. IF THE GFS VERIFIES WE MAY HAVE SHOWERS OVER
THE NORTH BY SUNDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 955 PM MST SAT NOV 22 2014
WIDESPREAD PRECIPITATION HAS DEVELOPED ACROSS THE AREA EARLIER
THIS EVENING...WITH SNOW IN THE HIGHER VALLEYS AND MOUNTAINS...AND
RAIN IN THE LOWER WEST-CENTRAL AND SOUTHERN VALLEYS. SNOW LEVELS
ARE EXPECTED TO DROP INTO THE VALLEY BOTTOMS BY AROUND 09Z
TONIGHT. SNOW WILL DIMINISH FROM THE WEST ON SUNDAY. HOWEVER THE
COLORADO MOUNTAINS WILL CONTINUE TO SEE GOOD SNOWFALL RATES
THROUGH SUNDAY AFTERNOON AND EVENING. FLIGHT RESTRICTIONS ACROSS
MUCH OF THE AREA ARE EXPECTED TONIGHT AND INTO SUNDAY WITH
CIGS/VSBY DROPPING INTO THE MVFR/IFR CATEGORIES AT TIMES. TAF
SITES MOST AFFECTED WILL BE KASE...KTEX...KRIL...KEGE. ALSO
MOUNTAINS WILL BE OBSCURED IN SNOW AND LOW CLOUDS. STRONG WEST TO
NORTHWEST WINDS WILL CAUSE AREAS OF BLOWING SNOW IN THE MOUNTAINS
AND EXPOSED AREAS.
THESE STRONG WINDS AT MOUNTAINTOP LEVEL WILL ALSO RESULT IN
MODERATE TO STRONG TURBULENCE...ESPECIALLY IN THE LEE OF HIGHER
TERRAIN.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER WEATHER ADVISORY UNTIL 6 AM MST EARLY THIS MORNING FOR
COZ002-003.
WINTER WEATHER ADVISORY UNTIL 3 PM MST THIS AFTERNOON FOR COZ007-
008-011-014-018-019.
WINTER STORM WARNING UNTIL 6 PM MST MONDAY FOR COZ004-005-009-
010-012-013.
UT...WINTER WEATHER ADVISORY UNTIL 6 AM MST EARLY THIS MORNING FOR
UTZ023.
&&
$$
UPDATE...NL
SHORT TERM...CC
LONG TERM...JOE
AVIATION...EH
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
955 PM MST SAT NOV 22 2014
.UPDATE...
ISSUED AT 858 PM MST SAT NOV 22 2014
A QUICK SHOT OF SNOWFALL AHEAD OF THE FRONT CAUSED A QUICK INCH OF
SNOW IN THE TOWN OF VERNAL AND SURROUNDING COMMUNITIES. DO NOT
ANTICIPATE MUCH MORE ACCUMULATION BUT DECIDED TO ISSUE ADVISORY
FOR THAT ZONE AS LOCAL DISPATCH REPORTS NUMEROUS CAR ACCIDENTS
ACROSS THE AREA. THINK IT BETTER TO GET THE WORD OUT FOR THOSE
INDIVIDUALS CONSIDERING DRIVING TONIGHT. NO OTHER CHANGES TO
CURRENT WINTER HIGHLIGHTS.
UPDATE ISSUED AT 725 PM MST SAT NOV 22 2014
THE SURFACE COLD FRONT HAS ENTERED WRN WY AND IS DRAPED DOWN TO
THE SE THROUGH CENTRAL UTAH. A FEW LIGHTNING STRIKES ARE STILL
BEING OBSERVED ALONG THE FRONT BUT THE NUMBER HAS DROPPED
DRAMATICALLY IN THE LAST FEW HOURS. THIS TREND WILL CONTINUE
THROUGH THE EVENING HOURS. THE RADAR MOSAIC SHOWS WIDESPREAD
PRECIP ACROSS THE CWA THIS EVENING WITH MANY AREAS REPORTING...OR
HAVING REPORTED...SHOWERS OVER THE LAST FEW HOURS. THIS WILL
CONTINUE AS THE FRONT APPROACHES. BOTH THE HRRR AND NAM12
INITIALIZED WELL AND BRING THE FRONT THROUGH NRN AREAS BY ABOUT
MIDNIGHT...REACHING THE GRAND VALLEY AROUND 0300L AND THEN THE SAN
JUANS BY DAYBREAK. SNOTELS REPORTING A FEW INCHES OF SNOW FOR THE
PARK/GORE RANGES WHILE ONE SNOTEL IN ERN UT REPORTING AROUND 6
INCHES. CURRENT FORECAST CAPTURING CURRENT WEATHER WELL SO MADE NO
CHANGES.
&&
.SHORT TERM...(TONIGHT THROUGH SUNDAY NIGHT)
ISSUED AT 318 PM MST SAT NOV 22 2014
SATELLITE AND ANALYSIS SHOWS THE COLD FRONT OVER NW UT AND
NORTHERN NV ASSOCIATED WITH THE STORM SYSTEM TO MOVE THROUGH THE
AREA TONIGHT. RADAR SHOWS AN AREA OF LOWER CLOUDS AND SCATTERED
SHOWERS MOVING THROUGH CENTRAL CO WITH SOME SHOWERS REPORTED ALONG
INTERSTATE 70 EAST OF GRAND JUNCTION. THE FRONT SHOULD MOVE
THROUGH NORTHWEST CO BY ABOUT MIDNIGHT AND THEN DRAG THROUGH THE
REST OF THE AREA OVERNIGHT. THE BEST COLD ADVECTION AND DYNAMIC
SUPPORT SHOULD MOVE THROUGH BETWEEN ABOUT 04Z AND 12Z. FOLLOWING
FRONTAL PASSAGE...FROM NW TO SE ACROSS THE AREA TONIGHT...WINDS AT
MTN TOP LEVEL WILL SHIFT TO THE NW AND BECOME MORE NORTHERLY WITH
TIME SUNDAY. THIS WILL SHIFT THE FOCUS OF BEST SNOWFALL FROM WEST
TO NNW FACING SLOPES.
MOISTURE STEADILY ERODES SUNDAY...AS FORECAST SOUNDINGS SHOW ONLY
A SHALLOW SURFACE-BASED SATURATED LAYER REMAINING OVER THE
NORTHERN HALF OF THE AREA. TEMPERATURES IN THIS LAYER ARE IN THE
FAVORABLE RANGE FOR DENDRITIC GROWTH WITH A STRONG LAPSE RATE. IN
THESE CONDITIONS OROGRAPHIC SNOWFALL SHOULD CONTINUE IN THE
NORTHERN AND CENTRAL MOUNTAINS...BUT DIMINISH OVER THE VALLEYS AND
PLATEAUS. THE SOUNDING OVER THE SOUTHERN HALF OF THE AREA BECOMES
EVEN DRIER SO THERE A PAUSE IN SNOWFALL SHOULD OCCUR OVER MUCH OF
THE SOUTHERN MOUNTAINS SUNDAY NIGHT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 318 PM MST SAT NOV 22 2014
MONDAY IN NW FLOW A STRONG COLD DISTURBANCE DROPS THROUGH THE
REGION. AN ASSOCIATED -33C COLD CORE STEEPENS LAPSE RATES.
MOISTURE IS LIMITED AND WITH THE JET DIGGING THROUGH UTAH
DYNAMICS ARE NOT OVERLY IMPRESSIVE. BUT COLD ADVECTION...NW
OROGRAPHICS...AND THE SNOW PRODUCTION LAYER AT MTN TOP LEVEL
(-12C AT 700MB) WILL COMBINE TO PRODUCE ANOTHER ROUND OF
SIGNIFICANT SNOWFALL OVER THE NORTHERN AND CENTRAL MTNS. THE
CURRENT HIGHLIGHTS FOR MONDAY LOOK ON TRACK...THOUGH THE NW SAN
JUAN MTNS MAY NEED AN ADVISORY. HAVE RAISED POPS THERE. THE SNOW
SHOULD BE QUITE DRY FOR NOVEMBER...IN THE 20:1 RANGE.
SNOWFALL FINALLY DIMINISHES THROUGH MONDAY NIGHT AS THE TROUGH AND
ASSOCIATED JET SLIDES SE. THE MOIST MARGINALLY UNSTABLE LAYER
SHRINKS TOP DOWN INTO TUESDAY SO SOME SCATTERED SNOW SHOWERS ARE
EXPECTED IN THE EASTERN MTNS THROUGH TUESDAY AFTERNOON WITH LITTLE
ACCUMULATION EXPECTED.
TUESDAY NIGHT THROUGH SATURDAY...THE WEST COAST RIDGE SLOWLY
PROGRESSES INLAND BRINGING DRY CONDITIONS AND PERSISTENT VALLEY
INVERSIONS. UNDERCUT GUIDANCE TEMPERATURES INTO FRIDAY AS THE
RIDGE BUILDS OVER THE FORECAST AREA AND DEAMPLIFIES. THIS PROMISES
DRY CONDITIONS FOR THANKSGIVING. SATURDAY MODEL TIMING BREAKS
SOMEWHAT WITH THE GFS DIGGING THE NEXT TROUGH INTO WA-OR WHILE THE
EC HOLDS IT OFFSHORE. IF THE GFS VERIFIES WE MAY HAVE SHOWERS OVER
THE NORTH BY SUNDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 955 PM MST SAT NOV 22 2014
WIDESPREAD PRECIPITATION HAS DEVELOPED ACROSS THE AREA EARLIER
THIS EVENING...WITH SNOW IN THE HIGHER VALLEYS AND MOUNTAINS...AND
RAIN IN THE LOWER WEST-CENTRAL AND SOUTHERN VALLEYS. SNOW LEVELS
ARE EXPECTED TO DROP INTO THE VALLEY BOTTOMS BY AROUND 09Z
TONIGHT. SNOW WILL DIMINISH FROM THE WEST ON SUNDAY. HOWEVER THE
COLORADO MOUNTAINS WILL CONTINUE TO SEE GOOD SNOWFALL RATES
THROUGH SUNDAY AFTERNOON AND EVENING. FLIGHT RESTRICTIONS ACROSS
MUCH OF THE AREA ARE EXPECTED TONIGHT AND INTO SUNDAY WITH
CIGS/VSBY DROPPING INTO THE MVFR/IFR CATEGORIES AT TIMES. TAF
SITES MOST AFFECTED WILL BE KASE...KTEX...KRIL...KEGE. ALSO
MOUNTAINS WILL BE OBSCURED IN SNOW AND LOW CLOUDS. STRONG WEST TO
NORTHWEST WINDS WILL CAUSE AREAS OF BLOWING SNOW IN THE MOUNTAINS
AND EXPOSED AREAS.
THESE STRONG WINDS AT MOUNTAINTOP LEVEL WILL ALSO RESULT IN
MODERATE TO STRONG TURBULENCE...ESPECIALLY IN THE LEE OF HIGHER
TERRAIN.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER WEATHER ADVISORY UNTIL 6 AM MST SUNDAY FOR COZ002-003.
WINTER WEATHER ADVISORY UNTIL 3 PM MST SUNDAY FOR COZ007-008-011-
014-018-019.
WINTER STORM WARNING UNTIL 6 PM MST MONDAY FOR COZ004-005-009-
010-012-013.
UT...WINTER WEATHER ADVISORY UNTIL 5 AM MST SUNDAY FOR UTZ024.
WINTER WEATHER ADVISORY UNTIL 6 AM MST SUNDAY FOR UTZ023.
&&
$$
UPDATE...TGR
SHORT TERM...CC
LONG TERM...JOE
AVIATION...EH
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
231 AM EST SUN NOV 23 2014
.SYNOPSIS...
MOISTURE ALREADY RETURNING TO THE AREA AS SHOWERS CONTINUE TO PUSH
NORTHWARD ACROSS THE GA/SC. EXPECT PLENTY OF RAINFALL TO OCCUR
TODAY AND TONIGHT. A FRONT WILL MOVE INTO THE REGION MONDAY AND
IS EXPECTED TO STALL NEAR THE COAST TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
UPDATED THE FORECAST FOR THE REMAINDER OF THE OVERNIGHT PERIOD AS
88D REGIONAL SHOWS SHOWERS MOVING QUICKLY NORTHWARD ACROSS THE
PALMETTO STATE. MODELS CONTINUE TO SHOW IMPRESSIVE ISENTROPIC LIFT
DEVELOPING NORTHWARD THROUGH THE OVERNIGHT HOURS INTO THE DAYTIME
HOURS. THIS WILL HELP DEVELOP THE VERY WEAK SURFACE WEDGE THAT
WILL REMAIN IN PLACE THROUGH MOST OF THE DAY. THE HRRR MODEL
APPEARS TO BE ON TRACK WITH CURRENT RADAR TRENDS. AS THE RAIN
FILLS IN ACROSS THE STATE AND THE AIRMASS BECOMES NEARLY
SATURATED...EXPECT TEMPERATURES TO LEVEL OUT AND BE SLOW TO MOVE
UPWARD THROUGH THE DAY. EXPECT TEMPERATURES TO REMAIN IN THE
MIDDLE 40S TO LOWER 50S THROUGH THE REMAINDER OF THE NIGHT.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY NIGHT/...
BY SUNDAY...S/W WILL BE ACROSS THE LOWER MS RIVER VALLEY. LOW
PRESSURE DEVELOPING ACROSS THE SOUTHERN PLAINS. A WARM FRONT TO
OUR SOUTH WILL BEGIN TO TRY AND PUSH NORTHWARD THROUGH THE DAY ON
SUNDAY/SUNDAY NIGHT. LOOKING A MODEL LI FIELDS ALONG WITH SOME
WEAK SURFACE RIDING AND SFC WINDS FROM THE NE/E FOR MUCH OF THE
DAY ON SUNDAY. THIS INDICATES AT LEAST SOME WEAK WEDGE CONDITIONS
ACROSS MUCH OF THE CWA...ESPECIALLY ACROSS THE NORTHERN/CENTRAL
MIDLANDS ALONG WITH THE NRN CSRA. WITH INCREASING ISENTROPIC LIFT
AND MOISTURE FLUX INTO THE REGION. ANY RAINFALL SHOULD HELP
SUSTAIN WEDGE CONDITIONS. HOWEVER...BY LATE IN THE DAY SUNDAY AND
SUNDAY NIGHT...SURFACE FLOW WILL INCREASE FROM THE SE AND S AS 50
TO 60 KT LOW LEVEL JET APPROACHES. PW VALUES WILL RISE
DRAMATICALLY THROUGH THE PERIOD TO WELL ABOVE 1.5
INCHES...APPROACHING NEARLY 2.0 INCHES...BY SUNDAY AFTERNOON. THIS
IS MUCH HIGHER THAN CLIMATOLOGY FOR MID/LATE NOVEMBER. WITH SUCH
IMPRESSIVE ISENTROPIC LIFT AND MOISTURE FLUX...THE RAIN WILL BE
HEAVY AT TIMES DURING THE AFTERNOON AND EVENING HOURS
SUNDAY/SUNDAY NIGHT. AS THE WARM FRONT TRIES TO MOVE
NORTH/NORTHWEST ACROSS THE AREA LATE SUNDAY INTO SUNDAY
NIGHT...THE AIRMASS ACROSS THE AREA WILL BECOME MORE UNSTABLE.
THIS IS ESPECIALLY TRUE ACROSS THE EASTERN PORTION OF THE CWA
SOUTH OF I-20. SPC DAY TWO HAS THE SERN HALF OF THE PALMETTO STATE
IN A SLIGHT RISK FOR SEVERE THUNDERSTORMS. THIS IS WHERE THE BEST
SHEAR AND INSTABILITY WILL DEVELOP. HAVE MENTIONED ISOLATED TO
CHANCE OF THUNDERSTORMS FROM LATE SUNDAY AFTERNOON INTO SUNDAY
ACROSS MUCH OF THE AREA DEVELOPING FIRST IN THE SERN PORTION OF
THE CWA AND THEN NORTH/NORTHWEST INTO THE REMAINDER OF THE CWA.
RAINFALL AMOUNTS FROM 1.5 TO 2 INCHES...WITH LOCALLY HEAVIER
AMOUNTS...WILL BE POSSIBLE BY SUNDAY NIGHT.
ON MONDAY...THE COLD FRONT ASSOCIATED WITH THE LOW IN THE PLAINS
WILL TRY TO PUSH EASTWARD ACROSS THE AREA...BUT BY
AFTERNOON/EVENING BECOMES PARALLEL TO THE UPPER FLOW AND WILL
LIKELY SLOW/STALL ALONG THE COASTAL PLAIN OR NEAR THE COAST. THIS
IS WHERE MODELS BEGIN TO DISAGREE ON HOW FAR THE FRONT WILL PUSH
EASTWARD. AT THIS TIME...HAVE CONTINUE TO KEEP A CHANCE OF
SHRA/TSRA THROUGH MONDAY WITH FRONT IN THE VICINITY.
AS FOR TEMPERATURES...THEY WILL BE VERY TRICKY ON SUNDAY WITH
WEDGE AND APPROACHING WARM FRONT FROM THE SOUTH. HAVE STAYED ON
THE LOW SIDE OF GUIDANCE FOR SUNDAY WITH A TIGHT TEMPERATURE
GRADIENT FROM NW TO SE. THE HIGH FOR SUNDAY WILL MOST LIKELY OCCUR
DURING THE EVENING HOURS AS THE WARM FRONT PUSHES NWD.
TEMPERATURES WILL BE DRAMATICALLY WARMER ON MONDAY WITH BREEZY
SOUTH/SOUTHWEST WINDS AHEAD OF THE COLD FRONT WITH ALL OF THE
GUIDANCE IN THE MID/UPPER 70S.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
UNCERTAINTIES CONTINUE IN THE FORECAST THROUGH THE MIDDLE OF NEXT
WEEK. LATEST GFS/PREVIOUS ECMWF MODELS BEGIN TO SHIFT THE MAIN UPPER
TROUGH AXIS EASTWARD AS ENERGY DROPS INTO THE BASE OF THE TROUGH
ACROSS THE SOUTHERN PLAINS BY TUE/TUE NIGHT. BY TUE NIGHT...BOTH
MODELS BEGIN TO DEVELOP LOW PRESSURE IN THE GULF OF MEXICO AND
BRING A SYSTEM UP ALONG THE EAST COAST. THIS LOOKS SLIGHTLY MORE
WESTWARD WITH PRECIPITATION SHIELD AS WELL AS COOLER THAN PREVIOUS
RUNS. HAVE LOWERED HIGHS ON WEDNESDAY A COUPLE OF DEGREES FROM THE
PREVIOUS FORECAST. BY THURSDAY AND FRIDAY...BOTH MODELS HAVE TROFINESS
ACROSS THE EASTERN HALF OF THE COUNTRY...WITH HIGH PRESSURE
BUILDING INTO THE REGION AT THE SURFACE. DRY WEATHER THANKSGIVING
DAY THROUGH SATURDAY. EXPECT TEMPERATURES TO REMAIN BELOW NORMAL
THROUGH THE PERIOD.
&&
.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
DETERIORATING CONDITIONS THROUGH THE FORECAST PERIOD TODAY.
SURFACE HIGH PRESSURE RIDGE OVER THE AREA WILL WEAKEN TODAY AS LOW
PRESSURE DEVELOPS IN RESPONSE TO AN APPROACHING SHORTWAVE THAT
WILL CROSS THE AREA THIS EVENING. INCREASING SOUTHEASTERLY LOW
LEVEL FLOW WILL ALSO INCREASE MOISTURE AND RESULT IN THICKENING
AND LOWERING CLOUDS THROUGH THE MORNING HOURS. STRONG MOISTURE
ADVECTION WILL GET LIFTED ISENTROPICALLY OVER A WEAK SURFACE WEDGE
WITH MVFR CIGS EXPECTED AFTER 09Z. WIDESPREAD RAINFALL WILL MOVE
OVER THE REGION DURING THE MORNING HOURS AND CONTINUE THROUGH THE
DAY TODAY. DETERIORATING CONDITIONS WITH CIGS DROPPING TO IFR BY
12Z AGS/DNL AND CAE/CUB/OGB BY 15Z...WITH LIFR BECOMING POSSIBLE.
THERE MAY BE A BRIEF PERIOD BETWEEN 21Z AND 00Z AFTER THE WARM
FRONTAL PASSAGE BUT BEFORE THE COLD FRONTAL PASSAGE WHERE CEILINGS
MAY RECOVER AND SHOWERS BECOME LIGHT. HOWEVER THE TAF SITES WILL BE
IN THE WARM SECTOR AND INSTABILITY WILL INCREASE POSSIBLY ALLOWING
FOR MORE SHOWERS AND SOME THUNDERSTORMS TO FORM. WINDS WILL
GENERALLY BE FROM THE EAST AND GRADUALLY VEER TO THE SOUTHEAST AND
EVENTUALLY SOUTH AS THE WARM FRONT LIFTS NORTH THROUGH THE REGION.
EXTENDED AVIATION OUTLOOK...CEILING AND VISIBILITY RESTRICTIONS
ARE LIKELY IN RAIN SHOWERS THROUGH MONDAY AS A LOW PRESSURE
SYSTEM AFFECTS THE REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...FLASH FLOOD WATCH THROUGH MONDAY EVENING FOR SCZ030.
GA...NONE.
&&
$$
77
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1254 AM EST SUN NOV 23 2014
.SYNOPSIS...
MOISTURE WILL RETURN TO THE REGION TONIGHT THROUGH SUNDAY
NIGHT...WITH PLENTY OF RAINFALL EXPECTED TO OCCUR SUNDAY INTO
SUNDAY NIGHT. A FRONT WILL MOVE INTO THE REGION MONDAY AND IS
EXPECTED TO STALL NEAR THE COAST TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
DRY WEATHER WILL OCCUR FOR THE FIRST PART OF THE FORECAST
WITH RAIN OVERSPREADING THE AREA LATER TONIGHT AND INTO THE
OVERNIGHT PERIOD. HIGH PRESSURE WILL CONTINUE AT THE
SURFACE...ALTHOUGH THE CENTER OF THE HIGH WILL PUSH FURTHER OFF
THE COAST OVERNIGHT. VERY WEAK SURFACE WEDGE SHOULD REMAIN ACROSS
THE AREA THROUGH MUCH OF THE NIGHT. ALOFT...ALTHOUGH WE START OFF
DRY...CLOUDS AND MOISTURE WILL RAPIDLY BE ON THE INCREASE...ESPECIALLY
ACROSS THE SOUTHWESTERN CWA AS ISENTROPIC LIFT STRENGTHENS AND
MOVES OVER THE SURFACE WEDGE. REGIONAL RADAR LOOP SHOWS SHOWERS
ACROSS NORTHERN FLORIDA AND SOUTHEASTERN GEORGIA SHIFTING NORTHEAST
INTO THE FORECAST AREA. THE HRRR MODEL APPEARS TO BE ON TRACK
WITH CURRENT RADAR TRENDS...SO HAVE SPED UP THE TIMING OF THE
SHOWERS FILLING IN FROM SOUTHWEST TO NORTHEAST ACROSS THE FA.
TEMPERATURES MAY BE SOMEWHAT TRICKY TONIGHT. CLOUDS WILL CONTINUE
TO INCREASE AND TEMPERATURES SHOULD BECOME NEARLY STEADY OR EVEN
RISE SLIGHTLY FOR THE REMAINDER OF THE NIGHT. NORTHERN COUNTIES
SHOULD CONTINUE TO FALL UNTIL LATE TONIGHT BEFORE BECOMING STEADY
TOWARDS MORNING. FOR NOW...LOWS AROUND 50 ACROSS THE SOUTH...AND
AROUND 40 ACROSS THE NORTH STILL REASONABLE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY NIGHT/...
BY SUNDAY...S/W WILL BE ACROSS THE LOWER MS RIVER VALLEY. LOW
PRESSURE DEVELOPING ACROSS THE SOUTHERN PLAINS. A WARM FRONT TO
OUR SOUTH WILL BEGIN TO TRY AND PUSH NORTHWARD THROUGH THE DAY ON
SUNDAY/SUNDAY NIGHT. LOOKING A MODEL LI FIELDS ALONG WITH SOME
WEAK SURFACE RIDING AND SFC WINDS FROM THE NE/E FOR MUCH OF THE
DAY ON SUNDAY. THIS INDICATES AT LEAST SOME WEAK WEDGE CONDITIONS
ACROSS MUCH OF THE CWA...ESPECIALLY ACROSS THE NORTHERN/CENTRAL
MIDLANDS ALONG WITH THE NRN CSRA. WITH INCREASING ISENTROPIC LIFT
AND MOISTURE FLUX INTO THE REGION. ANY RAINFALL SHOULD HELP
SUSTAIN WEDGE CONDITIONS. HOWEVER...BY LATE IN THE DAY SUNDAY AND
SUNDAY NIGHT...SURFACE FLOW WILL INCREASE FROM THE SE AND S AS 50
TO 60 KT LOW LEVEL JET APPROACHES. PW VALUES WILL RISE
DRAMATICALLY THROUGH THE PERIOD TO WELL ABOVE 1.5
INCHES...APPROACHING NEARLY 2.0 INCHES...BY SUNDAY AFTERNOON. THIS
IS MUCH HIGHER THAN CLIMATOLOGY FOR MID/LATE NOVEMBER. WITH SUCH
IMPRESSIVE ISENTROPIC LIFT AND MOISTURE FLUX...THE RAIN WILL BE
HEAVY AT TIMES DURING THE AFTERNOON AND EVENING HOURS
SUNDAY/SUNDAY NIGHT. AS THE WARM FRONT TRIES TO MOVE
NORTH/NORTHWEST ACROSS THE AREA LATE SUNDAY INTO SUNDAY
NIGHT...THE AIRMASS ACROSS THE AREA WILL BECOME MORE UNSTABLE.
THIS IS ESPECIALLY TRUE ACROSS THE EASTERN PORTION OF THE CWA
SOUTH OF I-20. SPC DAY TWO HAS THE SERN HALF OF THE PALMETTO STATE
IN A SLIGHT RISK FOR SEVERE THUNDERSTORMS. THIS IS WHERE THE BEST
SHEAR AND INSTABILITY WILL DEVELOP. HAVE MENTIONED ISOLATED TO
CHANCE OF THUNDERSTORMS FROM LATE SUNDAY AFTERNOON INTO SUNDAY
ACROSS MUCH OF THE AREA DEVELOPING FIRST IN THE SERN PORTION OF
THE CWA AND THEN NORTH/NORTHWEST INTO THE REMAINDER OF THE CWA.
RAINFALL AMOUNTS FROM 1.5 TO 2 INCHES...WITH LOCALLY HEAVIER
AMOUNTS...WILL BE POSSIBLE BY SUNDAY NIGHT.
ON MONDAY...THE COLD FRONT ASSOCIATED WITH THE LOW IN THE PLAINS
WILL TRY TO PUSH EASTWARD ACROSS THE AREA...BUT BY
AFTERNOON/EVENING BECOMES PARALLEL TO THE UPPER FLOW AND WILL
LIKELY SLOW/STALL ALONG THE COASTAL PLAIN OR NEAR THE COAST. THIS
IS WHERE MODELS BEGIN TO DISAGREE ON HOW FAR THE FRONT WILL PUSH
EASTWARD. AT THIS TIME...HAVE CONTINUE TO KEEP A CHANCE OF
SHRA/TSRA THROUGH MONDAY WITH FRONT IN THE VICINITY.
AS FOR TEMPERATURES...THEY WILL BE VERY TRICKY ON SUNDAY WITH
WEDGE AND APPROACHING WARM FRONT FROM THE SOUTH. HAVE STAYED ON
THE LOW SIDE OF GUIDANCE FOR SUNDAY WITH A TIGHT TEMPERATURE
GRADIENT FROM NW TO SE. THE HIGH FOR SUNDAY WILL MOST LIKELY OCCUR
DURING THE EVENING HOURS AS THE WARM FRONT PUSHES NWD.
TEMPERATURES WILL BE DRAMATICALLY WARMER ON MONDAY WITH BREEZY
SOUTH/SOUTHWEST WINDS AHEAD OF THE COLD FRONT WITH ALL OF THE
GUIDANCE IN THE MID/UPPER 70S.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
UNCERTAINTIES CONTINUE IN THE FORECAST THROUGH THE MIDDLE OF NEXT
WEEK. LATEST GFS/PREVIOUS ECMWF MODELS BEGIN TO SHIFT THE MAIN UPPER
TROUGH AXIS EASTWARD AS ENERGY DROPS INTO THE BASE OF THE TROUGH
ACROSS THE SOUTHERN PLAINS BY TUE/TUE NIGHT. BY TUE NIGHT...BOTH
MODELS BEGIN TO DEVELOP LOW PRESSURE IN THE GULF OF MEXICO AND
BRING A SYSTEM UP ALONG THE EAST COAST. THIS LOOKS SLIGHTLY MORE
WESTWARD WITH PRECIPITATION SHIELD AS WELL AS COOLER THAN PREVIOUS
RUNS. HAVE LOWERED HIGHS ON WEDNESDAY A COUPLE OF DEGREES FROM THE
PREVIOUS FORECAST. BY THURSDAY AND FRIDAY...BOTH MODELS HAVE TROFINESS
ACROSS THE EASTERN HALF OF THE COUNTRY...WITH HIGH PRESSURE
BUILDING INTO THE REGION AT THE SURFACE. DRY WEATHER THANKSGIVING
DAY THROUGH SATURDAY. EXPECT TEMPERATURES TO REMAIN BELOW NORMAL
THROUGH THE PERIOD.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
DETERIORATING CONDITIONS THROUGH THE FORECAST PERIOD TODAY.
SURFACE HIGH PRESSURE RIDGE OVER THE AREA WILL WEAKEN TODAY AS LOW
PRESSURE DEVELOPS IN RESPONSE TO AN APPROACHING SHORTWAVE THAT
WILL CROSS THE AREA THIS EVENING. INCREASING SOUTHEASTERLY LOW
LEVEL FLOW WILL ALSO INCREASE MOISTURE AND RESULT IN THICKENING
AND LOWERING CLOUDS THROUGH THE MORNING HOURS. STRONG MOISTURE
ADVECTION WILL GET LIFTED ISENTROPICALLY OVER A WEAK SURFACE WEDGE
WITH MVFR CIGS EXPECTED AFTER 09Z. WIDESPREAD RAINFALL WILL MOVE
OVER THE REGION DURING THE MORNING HOURS AND CONTINUE THROUGH THE
DAY TODAY. DETERIORATING CONDITIONS WITH CIGS DROPPING TO IFR BY
12Z AGS/DNL AND CAE/CUB/OGB BY 15Z...WITH LIFR BECOMING POSSIBLE.
THERE MAY BE A BRIEF PERIOD BETWEEN 21Z AND 00Z AFTER THE WARM
FRONTAL PASSAGE BUT BEFORE THE COLD FRONTAL PASSAGE WHERE CEILINGS
MAY RECOVER AND SHOWERS BECOME LIGHT. HOWEVER THE TAF SITES WILL BE
IN THE WARM SECTOR AND INSTABILITY WILL INCREASE POSSIBLY ALLOWING
FOR MORE SHOWERS AND SOME THUNDERSTORMS TO FORM. WINDS WILL
GENERALLY BE FROM THE EAST AND GRADUALLY VEER TO THE SOUTHEAST AND
EVENTUALLY SOUTH AS THE WARM FRONT LIFTS NORTH THROUGH THE REGION.
EXTENDED AVIATION OUTLOOK...CEILING AND VISIBILITY RESTRICTIONS
ARE LIKELY IN RAIN SHOWERS THROUGH MONDAY AS A LOW PRESSURE
SYSTEM AFFECTS THE REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...FLASH FLOOD WATCH THROUGH MONDAY EVENING FOR SCZ030.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
115 AM EST SUN NOV 23 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 420 PM EST SAT NOV 22 2014
WV IMAGERY AND RUC ANALYSIS INDICATED ZONAL FLOW ACROSS THE NRN
CONUS WITH A STRONG 170 KNOT 250 MB JET MOVING INTO THE PAC NW. A
SHORTWAVE TROUGH WAS MOVING THROUGH SRN SASK AND NRN MT. A VIGOROUS
SRN SHORTWAVE TROUGH WAS LOCATED OVER WRN TEXAS. AT THE SFC...SRLY
FLOW PREVAILED FROM THE GULF TOWARD THE UPPER MS VALLEY AND NRN
LAKES BTWN HIGH PRES OVER THE MID ATLANTIC AND A 984 MB LOW INTO SRN
SASK. WAA HAS PUSHED TEMPS INTO THE MID AND UPPER 30S ACROSS UPPER
MI. ALTHOUGH THE LOW LEVEL MOISTURE THINNED OUT ENOUGH FOR SOME
SUNSHINE THIS AFTERNOON...ESPECIALLY IN DOWNSLOPE LOCATIONS...CLOUDS
OVER NRN WI AND WRN UPPER MI WERE FILLING IN AGAIN ACROSS THE AREA.
TONIGHT...ANY LINGERING DRY LOW LEVEL AIR WILL FILL IN TONIGHT WITH
STRONG LOW LEVEL MOISTURE ADVECTION THIS EVENING. SO...EXPECT BETTER
CHANCES FOR PCPN AS DRIZZLE OR POSSIBLY FREEZING DRIZZLE AS A
SUBSTANTIAL DRY LAYER REMAINS ABOVE 900 MB. SOME FOG WILL BE POSSIBLE
AS WELL AS DEWPOINTS CLIMB TO AROUND FREEZING OR SLIGHTLY ABOVE BY
LATE TONIGHT. EXPECT THE BEST CHANCE FOR DRIZZLE OVER CNTRL UPPER MI
WITH AN UPSLOPE LOW LEVEL WIND COMPONENT SUPPORT...AND OVER THE EAST
CWA WITH ADDED MOISTURE OFF OF LAKE MICHIGAN. TEMPS MAY DROP OFF TO
NEAR FREEZING THIS EVENING AND SLOWLY CLIMB OVERNIGHT.
HOWEVER...SINCE MANY ROAD SURFACES MAY STILL BE BELOW FREEZING...ANY
DRIZZLE THAT FALLS COULD CREATE ICY/SLIPPERY CONDITIONS ON UNTREATED
ROADS.
SUN...EXPECT PCPN CHANCES TO GRADUALLY INCREASE THROUGH THE DAY AS
THE STRONG MOISTURE ADVECTION CONTINUES AND 850-700 MB FGEN
INCREASES. THE GREATEST CHANCE IS EXPECTED OVER THE EAST IN
PROXIMITY TO THE STRONGER DYNAMICS AND BEST MOISTURE. AS THE DRY
LAYER FILLS IN ANY DRIZZLE WILL CHANGE OVER TO RAIN BY MID TO LATE
AFTERNOON. TEMPS WILL CLIMB ABOVE NORMAL INTO THE LOW TO MID 40S.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 426 PM EST SAT NOV 22 2014
QUITE AN ACTIVE START TO THE PERIOD AS THE PHASING OF NORTHERN AND
SOUTHERN ENERGY WILL BE UNDERWAY ACROSS THE UPPER GREAT LAKES.
MODERATE RAINFALL SUNDAY NIGHT WILL GIVE WAY TO A TRANSITION TO SNOW
ON MONDAY AS THE SYSTEM MOVES NE OF THE REGION. THE INGREDIENTS ARE
STILL THERE FOR MODERATE TO POSSIBLY HEAVY SNOW ACROSS AT LEAST THE
WESTERN CWA MONDAY AFTERNOON AND NIGHT. AFTER A REPRIEVE LATE
TUESDAY...A CLIPPER SYSTEM LOOKS TO BRING LIGHT TO POSSIBLY MODERATE
SNOWFALL WEDNESDAY AFTERNOON INTO THANKSGIVING.
SUNDAY NIGHT THROUGH MONDAY NIGHT...FIRST A LOOK AT THE OVERALL
SYNOPTIC PATTERN. TWO POTENT MID-LEVEL SHORTWAVES...ONE TRACKING
EASTWARD OVER THE NORTHERN PLAINS AND THE OTHER MOVING NORTHEASTWARD
NEAR SOUTHERN IL AT 00Z MONDAY WILL BEGIN TO MERGE ACROSS THE UPPER
GREAT LAKES. THE NORTHERN STREAM IS A BIT SLOWER REACHING THE REGION
THAN THE SOUTHERN STREAM...RESULTING IN A BROADENING OF THE TROUGH
BY MONDAY MORNING. MEANWHILE...A DEVELOPING MODEST COUPLED JET
PATTERN WILL DEVELOP OVER THE UPPER GREAT LAKES. THE SOUTHERN WAVE
WILL BE OF MOST INTEREST INITIALLY AS IT INDUCES A RAPIDLY DEEPENING
LOW OVER ILLINOIS AT THE START OF THE PERIOD. WITH THE 12/18Z NAM
RUNS COMING INTO BETTER AGREEMENT WITH THE OTHER MODELS...CONFIDENCE
IS NOW HIGHER REGARDING THE OVERALL EVOLUTION OF THE SYSTEM. THE SFC
LOW IS PROGGED TO TRACK NEAR THE STRAITS OF MACKINAC AROUND 12Z
MONDAY. THE GEM/NAM/ECMWF HINT AT A SLIGHT DEVIATION TO THE LEFT/NW
MONDAY MORNING...WITH THE LOW CROSSING NEAR SAULT STE MARIE. THIS
LOOKS REASONABLE AS THE INFLUENCE OF THE NORTHERN TROUGH APPROACHES.
A LINGERING TROUGH WILL THEN REMAIN ACROSS UPPER MI ON MONDAY AS THE
MID-LEVEL TROUGH AXIS REACHES THE REGION AND THE SFC LOW MOVES TO
JUST SE OF JAMES BAY.
NOW A LOOK AT THE OVERALL PRECIP TYPE AND INTENSITY. MID/UPPER-LEVEL
DYNAMICS AND LOW-LEVEL THERMODYNAMICS SUPPORT MODERATE RAIN ACROSS
MAINLY CENTRAL AND EASTERN UPPER MI SUNDAY NIGHT. THE RIGHT ENTRANCE
OF A DEVELOPING...ALBEIT ANTICYCLONICALLY CURVED...UPPER JET WILL
MAXIMIZE UPPER DIVERGENCE OVER CENTRAL AND EASTERN UPPER MI WHILE
MID-LEVEL Q-VECTOR CONVERGENCE PEAKS OVER NORTHERN LOWER MI.
MEANWHILE...LOW-LEVEL MOISTURE TRANSPORT WILL BE RATHER IMPRESSIVE
ACROSS THE EASTERN CWA...THEN QUICKLY DIMINISH TOWARD THE WESTERN
CWA. A SUFFICIENTLY DEEP LOW-LEVEL WARM LAYER WILL KEEP PRECIP ALL
RAIN ACROSS THE CWA...THOUGH A TRANSITION TO SNOW WILL BE UNDERWAY
LATE SUNDAY NIGHT ACROSS THE WEST AS CAA BEGINS BEHIND THE LOW. ALL
THIS TOGETHER FAVORS MODERATE RAIN ACROSS THE EAST HALF SUNDAY
NIGHT...WITH AN INITIALLY SHARP CUTOFF TO THE WEST BEFORE THE
NORTHERN WAVE APPROACHES OVERNIGHT.
CAA TAKING HOLD ON MONDAY WILL QUICKLY TRANSITION THE RAIN TO SNOW
FROM WEST TO EAST THROUGHOUT THE DAY. THERE ARE SOME INDICATIONS
THAT A LOW-LEVEL WARM LAYER MAY TRY TO WRAP AROUND THE BACK SIDE OF
THE LOW LATE MORNING MORNING INTO THE AFTERNOON. SOME SLEET MAY MIX
IN WITH THE RAIN/SNOW...BUT THE TRANSITION FROM ALL RAIN SNOW SHOULD
NOT TAKE MORE THAN AN HOUR OR TWO. THINK THAT EVEN THE SHORELINE
LOCATIONS SHOULD TRANSITION QUICKLY GIVEN THEN COLDER THAN AVERAGE
LAKE TEMPS. TRANSITION TIMES LOOK TO BE AROUND 09Z FOR IWD...12Z FOR
A LINE FROM HOUGHTON TO IRON RIVER...AND 15Z FOR A LINE FROM
MARQUETTE TO IMT. BY 21Z...ALL BUT POSSIBLY LUCE COUNTY SHOULD
TRANSITION TO SNOW.
A FAIRLY IMPRESSIVE MID-LEVEL FGEN/DEFORMATION ZONE WILL SET UP OVER
THE WESTERN CWA BY MONDAY AFTERNOON. WITH SOME SNOWFLAKE FRACTURING
FROM THE HIGHER WINDS AND THE MAX LIFT INITIALLY OCCURRING AT TEMPS
JUST A BIT WARMER THAN THE DGZ...SNOW RATIOS MAY REMAIN LOW /10 TO
1/ THROUGH MONDAY MORNING. AS TEMPS CONTINUE TO FALL IN TO THE
AFTERNOON SNOW RATIOS WILL BE ON THE RISE ACROSS THE WEST. LOW-LEVEL
WINDS AVERAGING OUT THE NORTH COMBINED WITH LAKE-850MB DELTA TEMPS
SURPASSING 10C SUPPORT DECENT LAKE-ENHANCEMENT FOR THE NORTH WIND
SNOW BELTS THROUGHOUT MONDAY. THIS PATTERN WILL CONTINUE INTO MONDAY
EVENING AS THE CONSOLIDATED TROUGH SLOWS OVER THE AREA AND KEEPS A
SFC TROUGH EXTENDED ACROSS MUCH OF EASTERN UPPER MI. ON TOP OF THE
SNOW...THE CAA WITH A STRONG WNW TO ESE ISALLOBARIC COMPONENT FROM
THE RAPIDLY DEEPENING LOW WILL YIELD A QUICK INCREASE IN WIND FROM
THE N/NNW.
WHEN ALL IS SAID AND DONE...SNOWFALL MONDAY AND MONDAY NIGHT IS
EXPECTED TO BE 6 TO 10 INCHES BASICALLY NORTH OF M-28 AND WEST OF
MARQUETTE. ELSEWHERE ACROSS THE CWA...2-4 INCHES IS EXPECTED.
HOWEVER...HIGHER AMOUNTS OF UP TO 6 INCHES WILL BE POSSIBLE FOR THE
NNW WIND SNOW BELTS FROM SHOT POINT TO GRAND MARAIS. THREW AROUND
THE IDEA OF A WINTER STORM WATCH FOR THE NW HALF...BUT DECIDED
AGAINST IT GIVEN SOME DETAILS IN QPF AND PLACEMENT OF FORCING THAT
NEED TO BE IRONED OUT. HOWEVER...WINTER WX ADVISORY CRITERIA SHOULD
BE MET. HAVE OPTED TO ISSUE A SPECIAL WX STATEMENT AT THIS TIME TO
HIGHLIGHT THE POTENTIAL...BUT ALSO NOTE THE UNCERTAINTY IN AMOUNTS.
MAIN IMPACTS WILL BE RATHER SLUSHY ROADS IN THE AFTERNOON FOLLOWED
BY BLOWING AND DRIFTING OF THE SNOW OVERNIGHT AS SNOW RATIOS
INCREASE.
TUESDAY THROUGH WEDNESDAY NIGHT...WEAK MID-LEVEL RIDGING...LOW-LEVEL
WAA AND INVERSION HEIGHTS FALLING BELOW 3KFT WILL PUT A QUICK END TO
THE LES FROM WEST TO EAST THROUGHOUT THE DAY. A CLIPPER SHORTWAVE
WILL TRACK SE INTO THE UPPER MS VALLEY LATE TUESDAY. THE SHORTWAVE
LOOKS TO GET CAUGHT UP IN A LARGER-SCALE TROUGH OVER HUDSON
BAY...ULTIMATELY SLOWING ITS PROGRESSING AND SHIFTING IT TO A ENE
TRACK. WHERE THIS TAKES PLACE WILL BE CRUCIAL FOR DETERMINING SNOW
PROBABILITY/AMOUNTS FOR THE CWA. THE GFS IS THE FASTEST...BRINGING
WIDESPREAD ACCUMULATING SNOW TO THE AREA LATE TUESDAY NIGHT INTO
WEDNESDAY AFTERNOON. THE ECMWF TAKES AN INITIALLY MORE AGGRESSIVE
EVOLUTION...RESULTING THE THE TROUGH DIGGING FARTHER SOUTHEAST
BEFORE PIVOTING ACROSS SOUTHERN LAKE/LOWER MI. WITH THIS
SCENARIO...MOST OF THE SNOW HOLDS OFF UNTIL WEDNESDAY NIGHT. THE GEM
FOLLOWS A SOLUTION IN THE MIDDLE...BUT LEANS MORE IN LINE WITH THE
GFS. ATTM...CANNOT REALLY PIN DOWN AMOUNTS AND EXACT TIMING...THOUGH
THE PROSPECTS FOR SEVERAL INCHES OF ACCUMULATING SNOW SOMETIME LATE
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT ARE GROWING.
THANKSGIVING...DEPENDING ON WHAT MODEL SOLUTION PANS
OUT...WIDESPREAD SNOW MAY LINGER THROUGH THE MORNING OR END BEFORE
DAYBREAK. EITHER WAY...CAA BEHIND THE CLIPPER SHOULD YIELD LES FOR
THE N/NNW WIND BELTS DURING THE DAY. IT STILL LOOKS COLD...WITH
TEMPS MORE IN LINE WITH CHRISTMAS RATHER THAN THANKSGIVING.
HOWEVER...WITH THE SLOWER SOLUTION...THE ECMWF HAS A HARDER TIME
BRINGING THE COLDEST AIR INTO THE REGION.
FRIDAY AND SATURDAY...LONG RANGE MODELS HAVE BACKED OFF SOMEWHERE ON
A TRANSITION TO A MORE ZONAL AND MILD PATTERN BEGINNING FRIDAY AND
DELAY IT UNTIL LATE IN THE WEEKEND. THE OVERALL PATTERN LOOKS QUIET
BESIDE SOME LES FOR THE WNW WIND SNOW BELTS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 112 AM EST SUN NOV 23 2014
MOISTURE CONTINUING TO FLOW INTO THE AREA SHOULD RESULT IN LOWERING
OF CIGS FALLING TO LIFR LATE TONIGHT AS THE MOIST LOW-LEVELS WILL BE
ONLY BE AIDED BY ADDITIONAL MOISTURE AND HELPED ALONG BY DEVELOPING
UPSLOPE FLOW AT KCMX AND KSAW. THESE SITES WILL PROBABLY SEE DRIZZLE
AND FOG AS WELL WITH VSBY LIKELY REACHING IFR LATE TONIGHT.
CONDITIONS WILL STAY LIFR/VLIFR THROUGH THE REST OF THE FORECAST
PERIOD AT ALL SITES. &&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 420 PM EST SAT NOV 22 2014
SOUTH WINDS WILL INCREASE ON SUNDAY...ESPECIALLY OVER EASTERN
SECTIONS...BUT SHOULD REMAIN 30 KTS OR LESS. WINDS WILL BE VARIABLE
SUNDAY NIGHT AS TROUGH CROSSES LAKE SUPERIOR. A DEEPENING LOW WILL MOVE
TO EAST OF LAKE SUPERIOR ON MONDAY. NORTHERLY WINDS WILL INCREASE TO
GALES 40-45 KTS MONDAY AFTN INTO MONDAY NIGHT. WINDS DIMINISH TO 25
KTS OR LESS LATER TUESDAY INTO WEDNESDAY...THEN INCREASE TO 30 KTS
ON THURSDAY AS COLD AIR POURS ACROSS LAKE SUPERIOR BETWEEN HIGH PRESSURE
BUILDING OVER THE NORTHERN PLAINS AND LOW PRESSURE CROSSING THE
LOWER GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM MONDAY AFTERNOON THROUGH LATE MONDAY NIGHT FOR
LSZ248>250-265-266.
GALE WATCH FROM MONDAY MORNING THROUGH LATE MONDAY NIGHT FOR
LSZ242>245-263-264.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KLUBER
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION...UPDATED
NWS TWIN CITIES/CHANHASSEN MN
1211 AM CST SUN NOV 23 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 238 PM CST SAT NOV 22 2014
MAIN CONCERN DURING THE SHORT TERM PERIOD IS THE TREND OF STRATUS
AND THE POTENTIAL EXTENT OF FOG TONIGHT. A SECONDARY CONCERN IS WITH
PRECIP POTENTIAL TONIGHT INTO SUNDAY...THOUGH MODELS CONTINUE TO
SHOW PRECIP AMOUNTS BEING PRETTY UNDERWHELMING THROUGH SUNDAY ACROSS
THE ENTIRE MPX AREA...WITH DEEPER MOISTURE GOING ACROSS ERN WI AND
MICHIGAN.
EXTENSIVE STRATUS ACROSS ALL BUT THE NW PORTION OF THE MPX CWA HAS
HELD TEMPERATURES IN CHECK ALL DAY. LOOKING TO THE SOUTH...THERE ARE
A COUPLE OF MOISTURE SURGES HEADING OUR WAY. THE FIRST IS QUICKLY
MOVING INTO NRN IA AND WILL LIKELY BE TO THE I-90 CORRIDOR BY 00Z
THIS EVENING. IT IS CHARACTERIZED BY DEWPS IN THE 40S AND MORE
CONCERNING FOR THE CLOUD FORECAST TONIGHT...CLEAR SKIES. THE SECOND
MOISTURE SURGE IS JUST NOW GETTING TO I-80 AND IT IS ASSOCIATED WITH
DEWPS IN THE 50S...AND A RETURN TO LIFR STRATUS AND FOG. THE
ECMWF/GEM SHOW THIS SECOND MOISTURE SURGE AND ITS ASSOCIATED LOWER
50 DEWPS GETTING CLEAR UP TO I-90 SUNDAY MORNING BEFORE GETTING
SHUNTED OFF TO THE EAST. CERTAINLY DEWPS IN THE 40S WITH SNOW ON THE
GROUND FAVORS STRATUS CONTINUING THROUGH THE NIGHT AND THE CURRENT
FORECAST CERTAINLY READS THAT WAY...BUT WE WILL HAVE WATCH HOW THAT
CLEARING EVOLVES.
FOR FOG...ONE THING WE ARE POSITIVE ABOUT IS IT WILL BE HAZY TROUGH
THE NIGHT GIVEN DEWPS ABOVE FREEZING WITH SNOW ON THE GROUND. THERE
WAS TALK OF A DENSE FOG ADVISORY...BUT NOT CONFIDENT ENOUGH ON WHERE
TO PUT ONE OTHER THAN ANYONE UNDER STRATUS NOW...WHICH IS JUST ABOUT
OUR ENTIRE CWA AND DID NOT WANT TO ISSUE SUCH A LARGE ADVY AT THIS
POINT. ON TOP OF THAT...WE WILL BE MAINTAINING 8-12 KT WINDS THROUGH
THE NIGHT...SO THAT WILL SUPPLY A CERTAIN DEGREE OF MIXING AS WELL.
NOT TO MENTION WE HAVE THAT CLEARING RACING NORTH OUT OF IA. AT THIS
POINT...HIGHEST CONFIDENCE IN DENSE FOG IS WHERE OUR DEEPEST SNOW
RESIDES ACROSS THE NRN MPX CWA. THE HRRR WOULD SUPPORT THIS IDEA AS
IT DOES SHOW VSBYS IMPROVING THROUGH THE NIGHT ACROSS SRN MN AS THAT
SLUG OF SLIGHTLY DRIER AIR ACROSS IA WORKS INTO MN.
FOR TEMPERATURES...THEY MAY GO NOTHING BUT UP THROUGH THE NIGHT.
FIRST RUN OF THE HOURLY TEMPERATURE TOOL WITH THE LOCAL SUPERBLEND
BROUGHT A TEMPERATURE OF 53 TO ALBERT LEA BY 7Z TONIGHT. DID NOT GO
QUITE THAT AGGRESSIVE...BUT DO THINK MUCH OF THE AREA EAST OF A NEW
ULM TO MORA LINE WILL RISE INTO THE 40S OVERNIGHT. GIVEN THE MILD
START...ALSO GAVE HIGHS SUNDAY A BIT OF AN UPWARD NUDGE TO ABOUT A
50/50 BLEND BETWEEN THE PREVIOUS FORECAST AND THE 22.12 GEM/ECMWF.
THE GEM/ECMWF SHOW HIGHS IN THE LOW 50S FOR SE MN/WRN WI TOMORROW.
GIVEN THE EXTENSIVE CLOUD COVER...DO NOT THINK WE WILL GET THAT
HIGH...BUT DO HAVE HIGHS INTO THE MID/UPPER 40S FOR ALL BUT WRN AND
CENTRAL MN.
FOR PRECIP...THAT CONTINUES TO LOOK UNDERWHELMING. OUR BIGGEST
PROBLEM THROUGH TONIGHT CONTINUES TO BE THE FACT THAT THE ATMO CAN
NOT TAKE ON MUCH MORE MOISTURE BELOW 900 MB...BUT ABOVE THAT...ITS
BONE DRY. CONTINUED TO RUN WITH HIGHEST POPS SUNDAY OUT IN ERN AREAS
AS THEY WILL BE CLOSER TO THE H85 MOISTURE TRANSPORT...BUT LIKING
THE IDEA THE GFS/SREF/NMM/ARW SHOW OF A NARROW BAND OF RAIN CENTERED
ON FGEN IN THE H7-H6 LAYER COMING OUT OF SODAK TONIGHT AND WORKING
ACROSS SRN MN THROUGH SUNDAY MORNING. THE 22.18 HOPWRF MEMBERS ALSO
SHOW THIS BAND OF PRECIP BY 9Z /THE END OF THOSE RUNS/ MOVING INTO
THE WRN PORTION OF THE FSD FORECAST AREA...SIMILAR TO WHAT THE
MODELS MENTIONED ABOVE SHOW. DID BOOST POPS IN SW MN INTO THE HIGH
CHANCE CATEGORY SUNDAY MORNING FOR NOW. THIS MAY VERY WILL END UP
BEING THE BEST CHANCE AT SEEING MEASURABLE PRECIP WITH THIS SYSTEM
FOR MUCH OF OUR MN FORECAST AREA.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 238 PM CST SAT NOV 22 2014
SUNDAY NIGHT THROUGH MONDAY WILL BRING A PERIOD OF STRONG WINDS
AND LIGHT PRECIPITATION TO THE FORECAST AREA...IN THE WAKE OF A
DEEPENING MID LATITUDE CYCLONE. THE STRONGEST WINDS ARE EXPECTED
ACROSS THE WESTERN FORECAST AREA AND THE HIGHEST POTENTIAL FOR
ACCUMULATING SNOW REMAINS ACROSS FAR EASTERN MN...BUT ESPECIALLY
IN WEST CENTRAL WI.
BY 00Z MONDAY...RAPID CYCLOGENESIS WILL BE ONGOING IN THE MID
MISSISSIPPI RIVER VALLEY IN RESPONSE TO A DEEP TROUGH DIGGING IN
ACROSS THE CENTRAL CONUS AND A LARGE AREA OF 120-150M 500MB 12-HR
HEIGHTS FALLS MOVING ACROSS THE AREA. THE AMOUNT OF DEEPENING IS
STILL QUITE VARIABLE DEPENDING ON WHICH 12Z SOLUTION ONE CHOOSES TO
FOLLOW. THE 22.12Z GFS IS BY FAR AND AWAY THE MOST AGGRESSIVE IN
STRENGTHENING THE LOW OVER THE SOUTHERN HALF OF LAKE MICHIGAN BY
06Z MONDAY TO 975MB...969MB OVER NORTHERN MICHIGAN BY 12Z...AND
966MB AS IT MOVES NORTH OF THE GREAT LAKES BY 18Z. THE NAM AND
ECMWF SEEM MORE REASONABLE WITH A BIT MORE MODEST DEEPENING.
TYPICALLY...THE KIND OF DEEPENING THE GFS IS SHOWING ONLY OCCURS
WITH VERY STRONG BAROCLINICITY AND/OR A NEGATIVELY TILTED UPPER
TROUGH. WE REALLY DON`T HAVE EITHER. THERE IS STRONG COLD
ADVECTION AND A DECENT TEMPERATURE GRADIENT ACROSS THE MID/UPPER
MISSISSIPPI VALLEY...BUT THEY SEEM MORE IN LINE WITH THE NAM/ECMWF
THAT ARE BIT MORE PROGRESSIVE WITH THE LOW AND NOT AS WOUND UP.
THEREFORE...WE DID NOT JUMP ON THE GFS SNOWFALL FORECAST THAT
WOULD GIVE 6-8" TO PORTIONS OF WEST CENTRAL WI. WE THINK THE
HEAVIEST PRECIP SHOULD BE EAST OF THE FORECAST AREA AND THE
DYNAMIC COOLING ON THE BACK SIDE OF THE LOW WILL BE WEAKER THAN
THE GFS INDICATES. IT IS NOTABLE THAT THE 22.15Z SREF AND GEM ALSO
SHOW THE POTENTIAL FOR SEVERAL INCHES OF SNOW NEAR OR JUST EAST OF
THE FORECAST AREA. THIS IS SOMETHING TO FOLLOW OVER THE NEXT 12-18
HOURS...BUT WE SIMPLY DIDN`T HAVE ENOUGH CONFIDENCE TO ISSUE A
WINTER STORM WATCH AT THIS POINT. FURTHERMORE...EVEN WITH THE
EXPECTED STRONG WINDS...THE WARM TODAY HAS LIKELY LIMITED THE
AMOUNT OF SNOW AVAILABLE FOR BLOWING AND DRIFTING. THERE WERE A
LOT OF HIGHS IN THE UPPER 30S AND LOWER 40S IN WESTERN MN TODAY.
THE NEXT SYSTEM TO WATCH ARRIVES ON WEDNESDAY AND THERE IS AGAIN
SIGNIFICANT DIFFERENCES BETWEEN THE GFS AND ECMWF. THE ECMWF HAS A
POTENT CLIPPER SYSTEM WITH 1-4" OF SNOW...IMPRESSIVE COLD
ADVECTION AND A TIGHT PRESSURE GRADIENT ON THE BACK SIDE OF THE
SYSTEM. THE 22.12Z ECMWF HAS SUSTAINED 25-30KTS NEAR THE ND/SD/MN
BORDER EARLY WEDNESDAY MORNING - QUITE IMPRESSIVE GIVEN ITS
COARSER RESOLUTION. THE GFS HAS A WEAK SURFACE TROUGH AND MUCH
LESS LIFT. THIS MID WEEK SYSTEM PRETTY MUCH LOCKS IN OUR CHANCE
FOR A WELL BELOW NORMAL THANKSGIVING. IT LOOKS VERY COLD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1202 AM CST SUN NOV 23 2014
IMPRESSIVE WARM FRONT HAS MARCHED WELL INTO SOUTHERN MINNESOTA
LATE THIS EVENING WITH CONDITIONS IMPROVING TO THE SOUTH OF
IT...IN SOME CASES TO MVFR OR VFR. THINK ALL THE TAF SITES WILL
IMPROVE SOME THROUGH THE NIGHT IF THE WARM FRONT CONTINUES TO PUSH
NORTH...BUT CAUTION IS ADVISED AS CONDITIONS ARE DETEIORATING
SLOWLY AGAIN ACROSS NORTHERN IOWA. THIS MOISTURE COULD KEEP CIGS
IN LONGER ACROSS ERN MN AND WRN WI. RWF AND AXN APPEAR TO BE IN
THE BEST LOCATIONS FOR GREATEST IMPROVMENTS WITH UPSTREAM OBS VFR.
RAIN WILL PUSH INTO WRN WI SYUNDAY AFTERNOON...WITH SNOW ON THE
WESTERN PERIPHERY...POSSIBLY AS FAR WEST AS MSP.
KMSP...CONDITIONS HAVE IMPROVED QUITE A BIT IN THE LAST COUPLE
HOURS...BUT THAT TREND MAY HAVE STALLED FOR THE REST OF THE NIGHT.
COULD SEE VIS AND CIGS FLUCTUATE UP AND DOWN FOR THE NEXT SEVERAL
HOURS AS SURROUNDING OBS INDICATE. CONDS SHOULD LARGELY BE
MVFR...HOWEVER.
/OUTLOOK FOR KMSP/
MON...MVFR/IFR CIGS CHC -SN. WINDS NW 20G30 KT.
TUE...VFR. WINDS W 5-10 KT.
WED...MVFR/IFR CHC -SN. WINDS NW 10KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...DENSE FOG ADVISORY UNTIL 8 AM CST THIS MORNING FOR MNZ041>045-
047>053-057>063-066-068>070-078.
WI...DENSE FOG ADVISORY UNTIL 8 AM CST THIS MORNING FOR WIZ014>016-
023>028.
&&
$$
SHORT TERM...MPG
LONG TERM...CLF
AVIATION...BORGHOFF
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1207 AM CST Sun Nov 23 2014
.UPDATE:
Issued at 639 PM CST Sat Nov 22 2014
Have made some refinements to the POPS tonight into early Sunday
morning. The main axis of rain/showers this evening will reside
across southeast MO across southwest and south central IL within
the warm moist conveyor belt and ahead of a subtle impulse in the
southwest flow aloft. Further north and northwest across northeast
and central MO the chance of precipitation appears rather low
given the lack of any forcing, and if any occurs it will likely be
isolated or in the form of sprinkles or drizzle. The precipitation
threat will ramp up overnight however in central and northeast MO,
especially after 08-09z with large scale ascent associated with a
shortwave currently over TX moves northeastward into the area and
low level flow backs refocusing the lift westward. Lift and
showers/rain associated with this wave will overspread the entire
area early-mid Sunday morning.
Glass
&&
.SHORT TERM: (Through Late Tonight)
Issued at 347 PM CST Sat Nov 22 2014
Scattered showers are already moving across the southern half the
CWA this afternoon in an area of modest 925-850mb moisture
convergence ahead of the trough currently over the southern High
Plains. Expect rain to become more widespread late this afternoon
into the early evening hours over the southern two thirds of the CWA
as the showers currently over southwest Missouri continue to move
northeast into the area. This is being forced by an area of
stronger low level moisture convergence that the HRRR shows moving
across the area between 22-03Z. While there will still continue to
be scattered showers elsewhere behind this area through late
evening, it still appears that better chances for more widespread
rain will move in from the west after midnight. By that time, large
scale ascent and moisture convergence will be increasing ahead of the
aforementioned southern Plains trough that will be ejecting
northeastward ahead of longwave trough. With clouds and warm air
advection tonight, stayed with lows that were close to going
temperatures and MOS guidance.
Britt
.LONG TERM: (Sunday through Next Saturday)
Issued at 347 PM CST Sat Nov 22 2014
Rain and a few thunderstorms are expected on Sunday as a southern
stream, negatively tilted shortwave moves from eastern TX
northeastward into the TN and OH Valley regions, while a northern
stream upper level trough/low moves slowly east southeastward
through the northern Plains. The models were depicting upper level
divergence over our area between a strong upper level jet streak
across the southern Plains and a weaker upper level jet streak over
the Great Lakes region. The models have some discrepencies as to
the exact track of the deepening surface low, but at this time it
appears that it will move northeastward through or just north of the
STL area around 00z Monday. There will be ample instability for at
least isolated thunderstorms on Sunday into Sunday evening,
especially across southeast MO and southwest IL. Strong low level
cold air advection can be expected Sunday night after the passage of
the low and trailing cold front. The threat for precipitation will
continue Sunday night as shortwaves rotate through our area south of
the main upper level low/trough over the northern Plains. As the
colder air filters southeastward into the region the rain may change
over to light snow before ending late Sunday night/early Monday
morning across portions of northeast and central MO as well as west
central IL. Most of the precipitation will shift east of our
forecast area by Monday, although there may be some lingering light
snow or flurries mainly across west central IL. Much colder
temperatures can be expected for Monday, with nearly steady
temperatures, mainly in the middle 30s to lower 40s as the NAM and
ECMWF models drop the -8 degree C 850 mb isotherm southward to STL.
The GFS model is even colder and quicker bringing the colder air
southeastward into our forecast area. An unseasonably cold period
is expected through Tuesday night as a large amplitude positively
tilted upper level trough moves eastward through the central US.
The GFS and ECMWF models are still hinting at the possibility of a
northwest flow shortwave and associated weak surface low to bring a
quick shot of rain/snow to our area late Tuesday night and
Wednesday. The models, particularly the GFS are not as cold for
Thanksgiving Day with the coldest air remaining just north of our
forecast area, although a strong surface ridge is still forecast to
build southeastward into the region from the northern Plains on
Thanksgiving.
GKS
&&
.AVIATION: (For the 06z TAFs through 06z Sunday Night)
Issued at 1136 PM CST Sat Nov 22 2014
Specifics for KCOU, KUIN: An approaching low pressure system will
bring widespread rainfall and IFR conditions to the area on
Sunday. Winds will become northwesterly behind a cold front
towards the end of the 24-hr TAF period at KUIN. Just beyond the
end of the TAF period, a brief period of light snow is possible
while precipitation is ending.
Specifics for KSTL, KSUS, KCPS: Despite several hours of
persistent light rainfall at night along with steadily increasing
surface dew points, ceilings have remained predominantly VFR at
the St. Louis metro area TAF sites over the last 6 hours. Most
perplexing. In any event, confidence in cig/vis trends is lower
during the first 0-6 hours of the TAF period compared to later,
when a strong low pressure system will bring widespread rainfall
and IFR conditions to the area. Conditions will deteriorate with
time, especially after 10-12z. Winds will become westerly to
northwesterly and increase behind a cold front towards the end of
the 30-hr TAF period.
Kanofsky
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
354 AM EST SUN NOV 23 2014
.SYNOPSIS...
A WARM FRONT WILL LIFT NORTH THROUGH THE REGION THIS AFTERNOON AND
TONIGHT. A COLD FRONT WILL APPROACH FROM THE WEST MONDAY AND PUSH
OFFSHORE BY EARLY TUESDAY. LOW PRESSURE WILL DEVELOP ALONG THE FRONT
LATE TUESDAY NIGHT AND MOVE NORTHEAST OFFSHORE OF THE COAST WEDNESDAY.
THE LOW WILL DEPART TO THE NORTHEAST WEDNESDAY NIGHT WITH HIGH PRESSURE
BUILDING OVER THE REGION LATE IN THE WEEK.
&&
.NEAR TERM /TODAY/...
AS OF 330 AM SUNDAY...A WARM FRONT WILL MOVE NORTH THROUGH THE
DAY WITH WIDESPREAD LIGHT TO MODERATE RAIN ARRIVING THIS MORNING.
THE RAIN SHOULD BECOME STEADY BY EARLY AFTERNOON PER LATEST 3KM
HRRR AND RUC MODELS. TEMPERATURES TRICKY WITH COASTAL TROUGH
CURRENTLY IN PLACE WITH 61 DEGREES AT CAPE LOOKOUT BUT 41 IN
MOREHEAD CITY. AS WARM FRONT SURGES NORTH...TEMPERATURES SHOULD
RECOVER TO HIGHS IN THE MID/UPPER 60S AREA-WIDE. DEWPOINTS
CURRENTLY IN THE 30S SHOULD RECOVER TO THE UPPER 50S BY AFTERNOON.
POPS INCREASE TO CATEGORICAL OVER ROUGHLY THE SOUTHWESTERN HALF OF
THE CWA BY EARLY AFTERNOON. RAIN CHANCES REMAIN LOWER OVER THE
NORTHEASTERN HALF AS DEWPOINT RECOVERY WILL TAKE A BIT LONGER.
&&
.SHORT TERM /TONIGHT/...
AS OF 330 AM SUNDAY...BY THIS EVENING...INSTABILITY INCREASES FROM
THE SOUTH AS STRONG WARM FRONT MOVES NORTH. VERY IMPRESSIVE LOW-
LEVEL SHEAR VALUES INDICATED BY FORECAST SOUNDINGS...WITH SRH
HELICITY VALUES UPWARDS OF 600-700 BY 00Z TONIGHT. THIS COINCIDES
WITH THE ARRIVAL OF THE INSTABILITY AND MOST OF THE CWA REMAINS IN
A SLIGHT RISK OF SEVERE TSTMS. THE PRIMARY THREAT WILL BE STRONG
DAMAGING WINDS AND THE RISK OF ISOLATED TORNADOES GIVEN THIS SHEAR
ENVIRONMENT. THE TORNADO/SEVERE THREAT SHOULD WANE AFTER 06Z AS
THE FLOW BECOMES MORE UNIDIRECTIONAL. IN ADDITION TO THE SEVERE
THREAT...QPF TOTALS OF 1 TO 2 INCHES WILL BE POSSIBLE AS DEEP
MOISTURE IS ADVECTED FROM THE ATLANTIC WITH VERY IMPRESSIVE LOW-
LEVEL MOISTURE TRANSPORT. GIVEN THE WARM SW WINDS...EXPECT
TEMPERATURES TO FALL VERY LITTLE TONIGHT...LIKELY REMAINING IN THE
LOWER 60S.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
AS OF 330 AM SUN...LARGE UPPER TROUGH OVER THE CENTRAL PART OF THE
COUNTRY WITH LOTS OF ENERGY ROTATING AROUND IT WILL MAKE FOR AN
ACTIVE PERIOD INTO THANKSGIVING WITH HIGH PRESSURE TAKING HOLD
THROUGH THE REMAINDER OF THE PERIOD. THIS ACTIVE WEATHER COULD
HAMPER HOLIDAY TRAVEL PLANS.
TROUGH WILL CONTINUE TO DIG INTO THE SOUTHERN TIER STATES THROUGH
MID WEEK THEN LIFT THROUGH THE SOUTHEAST AND MID ATLANTIC THROUGH
THE END OF THE WEEK. MOST OF THE PRECIPITATION CHANCES WILL END BY
MONDAY MORNING ASSOCIATED WITH A VIGOROUS SHRTWV MOVING THROUGH THE
AREA. KEPT SMALL CHANCE POPS IN ON MONDAY UNTIL THE FIRST COLD FRONT
MOVES THROUGH THE AREA TUESDAY NIGHT. WON`T GET MUCH OF A BREAK AS
STRONG UPPER LEVEL ENERGY WILL SWING THROUGH THE BASE OF THE UPPER
TROUGH HELPING TO FORM A WAVE ON THE SURFACE FRONT IN THE GULF
TUESDAY THAT WILL MOVE UP THE EAST COAST DURING THE NIGHT TUESDAY
NIGHT. CROSS SECTIONS SHOWING DEEP LAYER MOISTURE AND GOOD LIFT. AS
MENTIONED. THE 00Z GFS AND ECMWF ARE NOW CLOSER IN PHASE
WITH THEIR SOLUTIONS WITH DEEP THE TROUGH AND AREA OF LOW PRESSURE
DEEPENING ALONG THE COAST WEDNESDAY BUT STILL HAVE DIFFERENCES THAT
WILL AFFECT THE FCST...ESPECIALLY ON THE EXACT TRACK OF THE LOW AND
STRENGTH OF WINDS. MODELS DO BOTH PRODUCE A GOOD AMOUNT OF QPF WITH
HEAVY RAINS AND WINDY CONDITIONS DEVELOPING LATE TUESDAY NIGHT AND
CONTINUING THROUGH THE DAY WEDNESDAY WITH PRECIPITATION ENDING
WEDNESDAY NIGHT AS THE LOW PULLS AWAY FROM THE COAST. THE AREA WILL
LIKELY SEE 1 TO 2 INCHES OR RAIN FROM LATE TUESDAY NIGHT THROUGH THE
EVENING WEDNESDAY. INCREASED POPS TO LIKELY INLAND TO CATEGORICAL
ALONG THE COAST WEDNESDAY.
THE GFS SHOWS A CHANCE THERE WILL BE A BIT OF MOISTURE LEFT ACROSS
THE AREA AS A SURGE OF COLD AIR GETS USHERED IN BEHIND THE DEPARTING
SYSTEM WEDNESDAY NIGHT. THAT COULD RESULT IN A BRIEF RAIN SNOW MIX
OR PERHAPS FLURRIES. THE ECMWF SEEMS TO MORE LIKELY HAVE MOST OF THE
MOISTURE DEPART BEFORE COLDER AIR. NOT MUCH CONFIDENCE ON WHICH
SOLUTION WILL BE RIGHT AT THIS POINT BUT OPTED FOR MORE LIKELY
KEEPING PRECIPITATION ALL RAIN HERE. EVEN IF WE DID SEE A FEW FLAKES
WEDNESDAY NIGHT DO NOT EXPECT IT WOULD NOT AMOUNT TO ANYTHING.
THURSDAY INTO SATURDAY DRIER AND COOL HIGH PRESSURE BUILDS OVER THE
AREA WITH MOSTLY SUNNY SKIES BUT BELOW NORMAL TEMPERATURES.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
SHORT TERM /TODAY AND TONIGHT/...
AS OF 1250 AM SUNDAY...VFR CONDITIONS SHOULD PREVAIL OVERNIGHT
AND INTO THE AFTERNOON HOURS ON SUNDAY AS HIGH CLOUDS THICKEN.
WARM FRONT WILL SURGE NORTH DURING THE AFTERNOON WITH DEWPOINTS
INCREASING AND S/SE WINDS BECOMING GUSTY WITH SHOWERS BECOMING
WIDESPREAD. SOME LOCALLY STRONG TSTMS MAY BE POSSIBLE TONIGHT WITH
GUSTY WINDS. EXPECT CEILINGS AND VSBYS TO DROP TO MVFR BY LATE
AFTERNOON INTO TONIGHT WITH WIDESPREAD PRECIPITATION.
LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 330 AM SUN...MVFR/IFR CONDITIONS SHOULD IMPROVE TO MVFR TO VFR
ON MONDAY AFTER THE WARM FRONT AND VIGOROUS SHRTWV PASSES THROUGH
THE AREA. THERE WILL STILL BE A SMALL CHANCE OF RAIN WITH SUB VFR
CONDITIONS POSSIBLE IN THE PRECIPITATION MONDAY AND TUESDAY. A
STRONG LOW PRESSURE WILL MOVE UP THE COAST TUESDAY NIGHT WITH IFR
CONDITIONS LIKELY...IN ADDITION TO RAIN AND STRONG WINDS THROUGH THE
DAY WEDNESDAY. BY THU HIGH PRESSURE BUILDS IN AND VFR CONDITIONS
RETURN.
&&
.MARINE...
SHORT TERM /TODAY AND TONIGHT/...
AS OF 340 AM SUNDAY...WILL UPGRADE GALE WATCH TO A GALE WARNING
BEGINNING THIS EVENING AND RUNNING THROUGH LATE MONDAY. LIGHT
SOUTHWEST WINDS CURRENTLY WITH SEAS 1 TO 3 FEET. AS A STRONG WARM
FRONT SURGES NORTH LATER THIS AFTERNOON...SE/ S WINDS SHOULD
INCREASE TO 15 TO 20 KNOTS WITH SEAS BUILDING TO 3 TO 5 FEET. BY
TONIGHT...S/SW WINDS INCREASE TO 25 TO 35 KNOTS WITH A FEW GUSTS
TO 40 KNOTS LIKELY WITH SEAS BUILDING TO AS HIGH AS 15 FEET PER
LOCAL NWPS/SWAN MODEL. THESE GUSTY WINDS AND ROUGH SEAS WILL
ACCOMPANIED BY AREAS OF HEAVY RAIN AND EMBEDDED THUNDERSTORMS...SOME
STRONG.
LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 330 AM SUN...WILL HAVE A CONTINUED PERIOD OF STRONG GUSTY
SOUTHERLY WINDS CONTINUING INTO MONDAY SLOWLY DIMINISHING FROM WEST
TO EAST AS THE COLD FRONT APPROACHES THE AREA. GALE CONDITIONS WILL
END BY LATE MONDAY ACROSS THE CENTRAL WATERS BUT SEAS WILL REMAIN
TREACHEROUS THROUGH MONDAY NIGHT. A WEAK COLD FRONT MOVES THROUGH
MONDAY NIGHT WITH LIGHT NORTHERLY WINDS FOR THE DAY TUESDAY.
STRONG LOW PRESSURE WILL DEVELOP ALONG THE FRONT OFF THE COAST
TUESDAY NIGHT AND MOVE UP THE COAST WEDNESDAY. THE GFS AND ECMWF
DIFFER A BIT ON THE LOCATION AND TIMING OF THE FRONT WITH THE 00Z
ECMWF KEEPING IT RIGHT ALONG THE COAST WHICH RESULTS IN LIGHTER
WINDS ON WEDNESDAY. FAVORED PREVIOUS FCST AND GFS FOR KEEPING THE
LOW JUST OFF THE COAST WHICH MAY ALLOW GALE CONDITIONS TO DEVELOP
WEDNESDAY WITH THIS FEATURE. CURRENT FCST HAS GUSTS TO GALE FORCE ON
WED IN STRONG NORTHERLY FLOW. SEAS 10 TO 12 FEET ARE POSSIBLE
WEDNESDAY INTO WEDNESDAY NIGHT AS A RESULT. CONDITIONS ONLY SLOWLY
IMPROVE BY THANKSGIVING MORNING...WITH SEAS FALLING BELOW 6 FEET IN
THE CENTRAL WATERS LATE IN THE DAY ON THANKSGIVING. WINDS WILL
EVENTUALLY BECOME LIGHT BY THE WEEKEND AS HIGH PRESSURE BUILDS OVER
THE AREA.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...GALE WARNING FROM 10 PM THIS EVENING TO 4 PM EST MONDAY FOR
AMZ130-131-135-137-150-152-154-156-158.
&&
$$
SYNOPSIS...CTC
NEAR TERM...CTC
SHORT TERM...CTC
LONG TERM...RSB
AVIATION...RSB/CTC
MARINE...RSB/CTC
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
333 AM EST SUN NOV 23 2014
.SYNOPSIS...
A POTENT STORM SYSTEM WILL BRING WIND....RAIN AND POSSIBLY A FEW
STRONG THUNDERSTORMS TO THE AREA TODAY. RAIN WILL RETURN LATE
TUESDAY AND WEDNESDAY AFTER A BREAK MONDAY. THANKSGIVING DAY TO
THE END OF THE FORECAST PERIOD LOOKS DRY AND COLD.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 940 PM SATURDAY...HIGH CLOUDS ARE OVERSPREADING THE
CAROLINAS WHILE MOISTURE ALSO INCREASES IN THE LOW LEVELS DUE TO
EAST-SOUTHEASTERLY FLOW OFF THE ATLANTIC OCEAN. IT SHOULD ONLY
TAKE ANOTHER 3-5 HOURS TO SEE MOSTLY CLOUDY TO CLOUDY SKIES IN
PLACE ACROSS THE ENTIRE FORECAST AREA...AND MORE IMPORTANTLY TO
SEE RAIN DEVELOPING ACROSS NE SOUTH CAROLINA. BASED ON THE LATEST
RADAR SUMMARY AND 23Z HRRR RUNS...I HAVE SPED UP THE INTRODUCTION
OF RAIN CHANCES TO THE FORECAST BY SEVERAL HOURS AND HAVE
INCREASED POPS THROUGH DAYBREAK AS WELL. EVEN ACROSS THE SANTEE
RIVER RIVER AREA I STILL ONLY THINK A FEW HUNDREDTHS OF AN INCH
WILL FALL BEFORE DAYBREAK. MORE SUBSTANTIAL MOISTURE ADVECTION AND
SYNOPTIC FORCING WILL ARRIVE DURING THE DAY TOMORROW.
TEMPERATURES SHOULD BE VERY NEAR THEIR LOWEST READINGS OF THE NIGHT
NOW. RADIATIONAL COOLING CONDITIONS SHOULD DETERIORATE FROM THIS
POINT FORWARD AS CLOUD COVERAGE INCREASES. AFTER DRAWING THE LATEST
HOURLY TEMPERATURE CURVES IN THE DIGITAL FORECAST I NOTED THE TEXT
FORMATTER USED THE "RISING TEMPERATURE" PHRASE FOR SOME COASTAL
ZONES TONIGHT. THIS IS GOOD AND DESCRIBES THE ANTICIPATED SHAPE OF
HOURLY TEMPERATURE CURVES NEAR THE COAST.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
AS OF 330 AM SUNDAY...A BROAD SOUTHWEST FLOW ALOFT WILL CONTINUE
MONDAY AND TUESDAY WITH THE AFFECTS OF MASSIVE LOW PRESSURE OVER
THE GREAT LAKES LINGERING MONDAY. A WEAK PRESSURE TROUGH APPEARS
TO BE THE CATALYST FOR A FEW SHOWERS MONDAY WITH A DRY 24 HOURS OR
SO ENSUING.
THE SOUTHWEST FLOW WILL BE ENHANCED LATER TUESDAY AS A MID LEVEL
TROUGH MOVES INTO THE TENNESSEE VALLEY. A POTENT 300MB JET WITH THE
RIGHT ENTRANCE REGION BECOMING FAVORABLY PLACED LATER TUESDAY AND
EARLY WEDNESDAY WORKS IN TANDEM WITH A DEEP MOISTURE PLUME AND
WIDESPREAD RAIN DEVELOPS ONCE AGAIN. I HAVE INCREASED POPS FOR LATE
IN THE PERIOD TO ADDRESS. NO CHANGES TO THE TEMPERATURE FORECAST
WITH A WARM DAY IN STORE MONDAY COOLING SOME 10-15 DEGREES TUESDAY.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 330 AM SUNDAY...MEDIUM RANGE GUIDANCE CONTINUES TO PAINT A WET
SCENARIO FOR WEDNESDAY AS LOW PRESSURE...WELL OFFSHORE WITH
EXCELLENT UPPER LEVEL SUPPORT WORKS TOGETHER. IT HAS BEEN
INTERESTING SEEING HE 850MB ZERO ISOTHERM MOVING INTO THE AREA
WITH PRECIPITATION BUT SOUNDINGS SHOW THE LOWER LEVELS JUST A BIT
TOO WARM FOR ANY FROZEN PRECIPITATION. I RAISED POPS INCREMENTALLY
TO ADDRESS THE GOOD MODEL CONTINUITY AND INCREASED CONFIDENCE.
BEYOND THIS THE MID LEVEL PATTERN WILL BECOME ZONAL BY THE WEEKEND
WITH HIGH PRESSURE AT THE SURFACE FOR THE MOST PART. THERE WILL BE
A DRY COLD FRONT THAT MOVES ACROSS FRIDAY BUT LITTLE ELSE.
TEMPERATURES REMAIN BELOW CLIMATOLOGY THROUGHOUT.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
AS OF 06Z...EXPECT VFR CONDITIONS TO PERSIST OVERNIGHT INTO THE
DAYTIME SUNDAY MORNING HOURS...WITH CONDITIONS GRADUALLY
DETERIORATING TO MVFR AND THEN IFR/LIFR TOWARDS THE END OF THE
06Z ISSUANCE PERIOD. LOW CIGS AND REDUCED VSBY FROM PCPN AND
FOG...WITH CONVECTION POSSIBLE ALONG AND/OR AFTER THE WFP THIS
AFTERNOON AND NIGHT.
VFR EXPECTED AT ALL TERMINALS OVERNIGHT AS LIGHT WINDS AND
SCT/BKN MID TO HIGH LEVEL CLOUDS MOVE IN. AFTER DAYBREAK...LOW TO
MID LEVEL CLOUDS WILL FURTHER INFILTRATE WITH CEILINGS STEADILY
LOWERING THRUOUT THE DAY AS THE WARM FRONT/COASTAL FRONT EITHER
PUSHES INLAND BEFORE ALTOGETHER LIFTING TO THE NORTH LATE THIS
AFTERNOON THRU THIS EVENING. INCREASING CHANCES FOR STRATIFORM
RAINS THROUGHOUT THE DAY. MODERATE RAIN AT TIMES...LOWERING CIGS
AND REDUCED VSBY FROM BOTH PCPN AND FOG WILL COMBINE TO CREATE
DETERIORATING CONDITIONS THIS AFTERNOON THRU THE EVENING HOURS.
ISOLATED THUNDERSTORMS REMAIN POSSIBLE IN THE VICINITY OF THE
COASTAL FRONT AND LIFTING WARM FRONT. BUT GIVEN LOWER CONFIDENCE
OF TIMING...HAVE OPTED TO NOT INTRODUCE ATTM. AS FOR WINDS...
EXPECT A VEERING TREND COMMENCING WITH VARIABLE OR NORTHEAST WINDS
OVERNIGHT...BECOMING EAST TO SOUTHEAST AS THE COASTAL FRONT AND
WARM FRONT APPROACH THIS AFTERNOON...AND BECOMING SOUTHERLY AFTER
THE WFP THIS EVENING. INITIALLY...SUSTAINED WINDS AROUND 5
KT...INCREASING TO 10 KTS DAYTIME SUNDAY MORNING...FURTHER
INCREASING TO AROUND 15+ KTS LATE THIS AFTERNOON AND EVENING.
EXTENDED OUTLOOK...UNSETTLED WEATHER IS EXPECTED MONDAY AND
POSSIBLY THROUGH TUESDAY...WITH OCCASIONAL SHOWERS AND MVFR/IFR
CONDITIONS. VFR LATE TUESDAY AFTERNOON WITH POSSIBLE MVFR
CONDITIONS WEDNESDAY. VFR THURSDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 940 PM SATURDAY...NO SIGNIFICANT CHANGE ARE NEEDED TO THE
FORECAST LATE THIS EVENING. OBSERVATIONS SHOW VEERING WINDS ACROSS
THE WATERS...MAINLY E TO NE ALONG THE BEACHES WITH SE WINDS OUT AT
THE FRYING PAN SHOALS BUOY. THE WARM FRONT SHOULD MAKE RAPID
PROGRESS TOWARD THE BEACHES OVERNIGHT WITH RISING TEMPERATURES
EXPECTED. FORTUNATELY THE MASSIVE INCREASE IN WIND SPEEDS WILL HOLD
OFF UNTIL DURING THE DAY SUNDAY. SEAS 2-3 FEET (LOCALLY 4 FEET IN
THE OUTER PORTION OF THE COASTAL WATERS) SHOULD CONTINUE THROUGH THE
NIGHT.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 330 AM SUNDAY...SMALL CRAFT CONDITIONS WILL CONTINUE MONDAY VIA
A STRONG SOUTHWEST FLOW OF 20-25 KNOTS AND SEAS OF 5-8 FEET. THE
WINDS WILL DIMINISH TUESDAY MORNING AND TURN TO THE WEST AS A WEAK
COLD FRONT PASSES. SEAS SHOULD FALL TO BELOW THE SMALL CRAFT
THRESHOLD SETTLING NICELY INTO A RANGE OF 2-4 FEET. ELEMENTS WILL
REMAIN TRANQUIL FOR THE REMAINDER OF THE PERIOD.
LONG TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 330 AM SUNDAY...FAIRLY BRISK NORTHWEST WINDS WEDNESDAY AS LOW
PRESSURE MOVES WELL OFFSHORE. SPEEDS WILL BE 20-25 KNOTS. WINDS
DIMINISH DRAMATICALLY THURSDAY AS A WEAK WESTERLY FLOW DEVELOPS.
SEAS WILL BE HIGHEST WEDNESDAY WITH 3-7 FEET...HIGHEST OFFSHORE.
VALUES DROP TO 2-4 FEET THURSDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 6 AM EST
TUESDAY FOR AMZ250-252-254-256.
&&
$$
SYNOPSIS...SHK
NEAR TERM...TRA/MBB
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...DCH/SGL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
123 AM EST SUN NOV 23 2014
.SYNOPSIS...
CLOUDS WILL INCREASE OVERNIGHT AHEAD OF A STORM SYSTEM TAKING
SHAPE IN THE GULF OF MEXICO. THIS SYSTEM WILL BRING MILD AND WET
WEATHER SUNDAY AND MONDAY AS IT LIFTS NORTHEAST. STRONG
THUNDERSTORMS WILL BE POSSIBLE LATE SUNDAY THROUGH EARLY MONDAY. A
COLD FRONT WILL CROSS THE COAST EARLY TUESDAY...STALLING OFFSHORE.
DEEPENING LOW PRESSURE WILL FORM ALONG THIS FRONT...BRINGING A COOL
WET CONDITIONS WEDNESDAY. CLEARING WEATHER IS EXPECTED THANKSGIVING
DAY WITH BELOW NORMAL TEMPERATURES THROUGH NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 940 PM SATURDAY...HIGH CLOUDS ARE OVERSPREADING THE
CAROLINAS WHILE MOISTURE ALSO INCREASES IN THE LOW LEVELS DUE TO
EAST-SOUTHEASTERLY FLOW OFF THE ATLANTIC OCEAN. IT SHOULD ONLY
TAKE ANOTHER 3-5 HOURS TO SEE MOSTLY CLOUDY TO CLOUDY SKIES IN
PLACE ACROSS THE ENTIRE FORECAST AREA...AND MORE IMPORTANTLY TO
SEE RAIN DEVELOPING ACROSS NE SOUTH CAROLINA. BASED ON THE LATEST
RADAR SUMMARY AND 23Z HRRR RUNS...I HAVE SPED UP THE INTRODUCTION
OF RAIN CHANCES TO THE FORECAST BY SEVERAL HOURS AND HAVE
INCREASED POPS THROUGH DAYBREAK AS WELL. EVEN ACROSS THE SANTEE
RIVER RIVER AREA I STILL ONLY THINK A FEW HUNDREDTHS OF AN INCH
WILL FALL BEFORE DAYBREAK. MORE SUBSTANTIAL MOISTURE ADVECTION AND
SYNOPTIC FORCING WILL ARRIVE DURING THE DAY TOMORROW.
TEMPERATURES SHOULD BE VERY NEAR THEIR LOWEST READINGS OF THE NIGHT
NOW. RADIATIONAL COOLING CONDITIONS SHOULD DETERIORATE FROM THIS
POINT FORWARD AS CLOUD COVERAGE INCREASES. AFTER DRAWING THE LATEST
HOURLY TEMPERATURE CURVES IN THE DIGITAL FORECAST I NOTED THE TEXT
FORMATTER USED THE "RISING TEMPERATURE" PHRASE FOR SOME COASTAL
ZONES TONIGHT. THIS IS GOOD AND DESCRIBES THE ANTICIPATED SHAPE OF
HOURLY TEMPERATURE CURVES NEAR THE COAST.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY NIGHT/...
AS OF 336 PM SATURDAY...PRIMARY HEADLINE THIS PERIOD...STRONG TO
SEVERE TSTM POTENTIAL LATE SUNDAY THROUGH EARLY MONDAY. LOW-LEVEL
SE WINDS WILL INTENSIFY...TRANSPORTING MOISTURE RICH GULF STREAM
AIR INTO THE COASTAL ZONES ELEVATING BOUNDARY LAYER DEWPOINTS.
A DEVELOPING AXIS OF POSITIVE MIXED-LAYERED CAPES WILL ORIENT
ITSELF ALONG OR JUST OFF THE COAST SUNDAY NIGHT THROUGH MONDAY
MORNING. THE HIGHEST HELICITY VALUES FAR PRECEDE THE MAXIMUM OF
ML-CAPE BUT SOME OVERLAP OF MODERATE CAPE/HELICITY EXISTS TO
WARRANT A CHANCE OF SEVERE STORMS...ALTHOUGH DIURNAL COOLING WILL
AND SLIGHT CHILLED INSHORE SST VALUES COULD OFFSET INCREASING
CONVECTIVE INTENSITY TRENDS.
NEXT NOTEWORTHY ITEM...PRECEDING THIS SEVERE POTENTIAL PLENTY
STRATIFORM RAIN APPEARS LIKELY...AND THE LATEST WPC QPF FORECAST
FOR SUNDAY AND MONDAY PAINTS 1.5-2.5 INCHES OF RAIN FOR OUR AREA
FOR THE 2-DAY PERIOD. STRATIFORM WILL TRANSITIONS TO CONVECTION AS
THE WARM FRONT LIFTS NORTH OF THE AREA INTO EARLY MONDAY.
EXCEPTIONALLY MILD MONDAY WITH MAXIMUM TEMPERATURES WELL INTO THE
70S IN A DEEP AND MOIST SW WIND FLOW ATOP THE AREA...AND FROPA
NEAR END OF THE PERIOD PRIOR TO DAYBREAK TUESDAY. COOLEST PORTION
OF PERIOD DAYBREAK SUNDAY WITH CLOUDS AND MIDDLE 40S. HIGHEST POP
VALUES SUNDAY NIGHT.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 336 PM SATURDAY...LINGERING FRONT STALLED OFF THE EAST COAST
TUE INTO WED AND SHORTWAVE DROPPING INTO THE WESTERN GULF WILL
BRING RAIN TO THE AREA DURING THE MIDDLE OF NEXT WEEK. WEAK
SURFACE WAVE DEVELOPING ON THE BOUNDARY OVER SOUTHERN FL EARLY TUE
WILL BE ENHANCED BY THE AFOREMENTIONED SHORTWAVE. AS THE LOW
TRACKS NORTHEAST ALONG THE FRONT...JUST OFF THE SE COAST...RAIN
WILL SPREAD OVER MUCH OF THE CAROLINAS. WED LOOKS AS THOUGH IT
COULD BE A MISERABLE DAY WITH THE FORECAST AREA ON THE COOL SIDE
OF THE LOW AND PERIODS OF HEAVY RAIN POSSIBLE. HIGHS WED MAY STAY
IN THE MID 40S WITH AROUND 50 ALONG THE COAST AND HAVE TRENDED
HIGHS DOWN.
RAPID DRYING WILL COMMENCE LATE WED INTO WED NIGHT AS 5H TROUGH
AXIS LIFTS NORTHEAST AND DEEP DRY AIR ARRIVES. BY THU AM
PRECIPITABLE WATER VALUES WILL BE AROUND 0.40 INCH AND SOUNDINGS
SHOW STRONG DOWNWARD MOTION. LATER HALF OF THE PERIOD REMAINS A
QUESTION WITH LATEST GFS/ECMWF DISAGREEING ON THE
STRENGTH/AMPLITUDE OF THE NEXT MID LEVEL TROUGH. GFS DEVELOPS
ZONAL FLOW ALOFT FRI/SAT WHILE THE ECMWF MAINTAINS 5H TROUGHING
INTO THE START OF THE WEEKEND. BOTH SOLUTIONS WOULD RESULT IN A
DRY FORECAST BUT WITH DIFFERENCES IN TEMPERATURES AND POSSIBLY
AFTERNOON CLOUD COVER. GFS ENSEMBLES ARE NOT VERY HELPFUL WITH
ROUGHLY AN EQUAL SPLIT BETWEEN THE 2 SOLUTIONS. INHERITED FORECAST
IS BASICALLY A BLEND OF THE GFS/ECMWF AND WILL CONTINUE WITH THIS
THINKING UNTIL THERE IS BETTER AGREEMENT.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 06Z...EXPECT VFR CONDITIONS TO PERSIST OVERNIGHT INTO THE
DAYTIME SUNDAY MORNING HOURS...WITH CONDITIONS GRADUALLY
DETERIORATING TO MVFR AND THEN IFR/LIFR TOWARDS THE END OF THE
06Z ISSUANCE PERIOD. LOW CIGS AND REDUCED VSBY FROM PCPN AND
FOG...WITH CONVECTION POSSIBLE ALONG AND/OR AFTER THE WFP THIS
AFTERNOON AND NIGHT.
VFR EXPECTED AT ALL TERMINALS OVERNIGHT AS LIGHT WINDS AND
SCT/BKN MID TO HIGH LEVEL CLOUDS MOVE IN. AFTER DAYBREAK...LOW TO
MID LEVEL CLOUDS WILL FURTHER INFILTRATE WITH CEILINGS STEADILY
LOWERING THRUOUT THE DAY AS THE WARM FRONT/COASTAL FRONT EITHER
PUSHES INLAND BEFORE ALTOGETHER LIFTING TO THE NORTH LATE THIS
AFTERNOON THRU THIS EVENING. INCREASING CHANCES FOR STRATIFORM
RAINS THROUGHOUT THE DAY. MODERATE RAIN AT TIMES...LOWERING CIGS
AND REDUCED VSBY FROM BOTH PCPN AND FOG WILL COMBINE TO CREATE
DETERIORATING CONDITIONS THIS AFTERNOON THRU THE EVENING HOURS.
ISOLATED THUNDERSTORMS REMAIN POSSIBLE IN THE VICINITY OF THE
COASTAL FRONT AND LIFTING WARM FRONT. BUT GIVEN LOWER CONFIDENCE
OF TIMING...HAVE OPTED TO NOT INTRODUCE ATTM. AS FOR WINDS...
EXPECT A VEERING TREND COMMENCING WITH VARIABLE OR NORTHEAST WINDS
OVERNIGHT...BECOMING EAST TO SOUTHEAST AS THE COASTAL FRONT AND
WARM FRONT APPROACH THIS AFTERNOON...AND BECOMING SOUTHERLY AFTER
THE WFP THIS EVENING. INITIALLY...SUSTAINED WINDS AROUND 5
KT...INCREASING TO 10 KTS DAYTIME SUNDAY MORNING...FURTHER
INCREASING TO AROUND 15+ KTS LATE THIS AFTERNOON AND EVENING.
EXTENDED OUTLOOK...UNSETTLED WEATHER IS EXPECTED MONDAY AND
POSSIBLY THROUGH TUESDAY...WITH OCCASIONAL SHOWERS AND MVFR/IFR
CONDITIONS. VFR LATE TUESDAY AFTERNOON WITH POSSIBLE MVFR
CONDITIONS WEDNESDAY. VFR THURSDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 940 PM SATURDAY...NO SIGNIFICANT CHANGE ARE NEEDED TO THE
FORECAST LATE THIS EVENING. OBSERVATIONS SHOW VEERING WINDS ACROSS
THE WATERS...MAINLY E TO NE ALONG THE BEACHES WITH SE WINDS OUT AT
THE FRYING PAN SHOALS BUOY. THE WARM FRONT SHOULD MAKE RAPID
PROGRESS TOWARD THE BEACHES OVERNIGHT WITH RISING TEMPERATURES
EXPECTED. FORTUNATELY THE MASSIVE INCREASE IN WIND SPEEDS WILL HOLD
OFF UNTIL DURING THE DAY SUNDAY. SEAS 2-3 FEET (LOCALLY 4 FEET IN
THE OUTER PORTION OF THE COASTAL WATERS) SHOULD CONTINUE THROUGH THE
NIGHT.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 336 PM SATURDAY...DETERIORATING MARINE CONDITIONS SUNDAY AS SE
WINDS CRANK UP TO 15-25 KT AHEAD OF AN APPROACHING WARM FRONT. S
AND SW BLUSTERY FLOW TO FOLLOW FOR MONDAY 15-25 KT...WHILE SEAS
PEAK MAINLY SUNDAY NIGHT DURING MAXIMUM IN S-SE WIND OFFSHORE OF
6-10 FEET AND HIGHEST OUTER WATERS. STRONG TO SEVERE THUNDERSTORMS
POSSIBLE SUNDAY NIGHT THROUGH MONDAY...GULF STREAM LATE MONDAY.
VENTURING OFFSHORE IS DISCOURAGED FOR SMALL CRAFT VESSELS SUNDAY AND
MONDAY.
LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 336 PM SATURDAY...FRONT STALLED OFF THE COAST TUE WILL HELP
MAINTAIN LIGHT NORTHERLY FLOW. LOW PRESSURE DEVELOPING ON THE FRONT
LATE TUE WILL TRACK NORTHEAST WED...PASSING JUST EAST OF THE WATERS.
AS THE LOW DEVELOPS THE GRADIENT WILL TIGHTEN UP WITH SPEEDS
INCREASING TO 20 TO 25 KT WED. LOW EXITS NORTHEAST WED NIGHT WITH
WINDS BACKING TO WESTERLY AS THE LOW EXITS. GRADIENT DECREASES WITH
SPEEDS DROPPING TO 10 TO 15 KT BY THU MORNING. SEAS 2 TO 3 FT ON TUE
WILL BUILD TO 4 TO 7 FT LATE WED IN RESPONSE TO INCREASED NORTHERLY
FLOW. DEVELOPMENT OF OFFSHORE FLOW BEHIND THE EXITING LOW DROPS SEAS
TO 2 TO 4 FT WED NIGHT AND AROUND 2 FT THU.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 6 AM EST
TUESDAY FOR AMZ250-252-254-256.
&&
$$
SYNOPSIS...MJC
NEAR TERM...TRA/MBB
SHORT TERM...MJC
LONG TERM...III
AVIATION...DCH/SGL
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1258 AM EST SUN NOV 23 2014
.SYNOPSIS...
MAINLY CLOUDY SKIES WITH EMBEDDED SHOWERS FROM TIME TO TIME
ARE IN STORE FOR TONIGHT IN A RELATIVELY MOIST AND MILD SOUTHWESTERLY
FLOW. FOR SUNDAY AND SUNDAY NIGHT...DEEPENING LOW PRESSURE WILL
PULL A LARGE SWATH OF MOISTURE NORTHWARD...RESULTING IN WIDESPREAD
RAIN SHOWERS. MORE SHOWERS AND WINDY CONDITIONS WILL ACCOMPANY A
COLD FRONT ON MONDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
LATEST 00Z NAM-WRF...HRRR AND RAP INDICATE THAT AREA OF SHOWERS
OVER EAST CENTRAL ILLINOIS/WEST CENTRAL INDIANA WILL EXPAND AND
PIVOT NORTHEAST OVERNIGHT. THIS PCPN IS IN RESPONSE TO AN
EMBEDDED S/WV AND LOW LEVEL JET WITHIN A MOIST SOUTHWEST PLUME.
HAVE INCREASED POPS TO LIKELY FOR NORTHWESTERN ZONES AFTER
MIDNIGHT WITH POPS RAPIDLY DECREASING AS ONE GOES TOWARD THE OHIO
RIVER. SKIES WILL BE MAINLY CLOUDY FOR MOST LOCATIONS.
TEMPERATURES HAVE ALREADY FALLEN OFF CONSIDERABLY IN SOUTH CENTRAL
OHIO AND NORTHEAST KENTUCKY WHILE IT REMAINS MILD ELSEWHERE. WE
SHOULD SEE A GRADUAL DECREASE IN TEMPERATURES NORTHERN/WESTERN
ZONES OVERNIGHT WITH SOME RECOVERY EXPECTED SOUTHEAST AS CLOUDS
THICKEN AND PERHAPS A LITTLE WIND PICKS UP.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY NIGHT/...
AN ELONGATED AREA OF LOW PRESSURE WILL BE STRENGTHENING TO THE
WEST ON SUNDAY. MOISTURE ARRIVING ON AN INCREASING SOUTHERLY FLOW
WILL OVERSPREAD THE AREA...BRINGING RAIN SHOWERS TO ALL LOCATIONS
BY SUNDAY EVENING. THE SHOWERS ARE LIKELY TO CONTINUE SUNDAY NIGHT
AND MONDAY AS THE LOW MOVES NORTH AND DEEPENS OVER THE GREAT
LAKES...WHILE DRAGGING A STRONG COLD FRONT FROM THE WEST. LOOKS
LIKE THE AREA COULD RECEIVE AROUND AN INCH OF RAINFALL ON AVERAGE
BY MONDAY AFTERNOON. SHOWERS SHOULD END MONDAY NIGHT AS THE SYSTEM
LIFTS NORTHEAST.
ANOTHER PROBLEM WILL INVOLVE STRONG WINDS...ESPECIALLY ON MONDAY IN
THE VICINITY OF THE COLD FRONT. CURRENT INDICATIONS ARE THAT
NUMEROUS GUSTS OF 35 TO 45 MPH ARE PROBABLE. IF CONDITIONS ARE
AS SUGGESTED BY THE WINDIER MAV GUIDANCE...THEN A WIND ADVISORY
MAY BE NEEDED.
WARM ADVECTION WILL BRING HIGHS INTO THE MID 50S TO AROUND 60 ON
SUNDAY. HIGHS ON MONDAY SHOULD STAY IN THE 50S WITH COLDER AIR
FILTERING IN FROM THE WEST MONDAY AFTERNOON.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
BELOW NORMAL HEIGHTS WITH MEAN TROF OVER THE NATIONS MID SECTION TO
START THE LONG TERM FORECAST PERIOD. PRECIPITATION SHOULD STAY NORTH
OF ILN/S FA WITH SFC HIGH PRESSURE BUILDING INTO THE OHIO VALLEY
TUESDAY. TEMPERATURES WILL BE CLOSE TO 15 DEGREES BELOW NORMAL...
WITH HIGHS FROM THE LOWER 30S NORTH TO THE LOWER 40S SE.
ILN/S FA BETWEEN SYSTEMS ON WED AS SFC HIGH PRESSURE SHIFTS EAST ON
WED. BELOW NORMAL TEMPERATURES TO CONTINUE WITH HIGHS RANGING FROM
THE MID 30S NORTH TO THE LOWER 40S SOUTH.
CLIPPER TYPE SYSTEM TO DROP SE THRU THE GREAT LAKES WITH ASSOCIATED
COLD FRONT SWEEPING EAST THRU ILN/S FA EARLY THURSDAY. WILL BRING
SNOW IN WED NIGHT AND CONTINUE INTO THURSDAY. SOME PCPN MIX WITH BE
POSSIBLE ACRS THE SOUTH. HAVE LEANED TOWARD THE COLDER ECMWF SOLN
AND HAVE LIMITED ANY MIX TO THE SE. BEST POPS ACRS THE NORTH CLOSER
TO THE SFC WAVE. EARLY HIGHS ON THURSDAY TO RANGE FROM THE LOWER 30S
NW TO NEAR 40 SE.
IN NORTHWEST FLOW AND CAA SOME LINGERING SNOW SHOWERS PSBL THURSDAY
NIGHT. SFC HIGH PRESSURE TO BUILD IN ON FRIDAY PROVIDING CONTD COLD
TEMPERATURES AND DRY CONDITIONS. HIGHS ON FRIDAY TO RANGE FROM THE
LOWER 30S NW TO THE UPR 30S SE.
SFC HIGH PRESSURE TO BUILD ACRS THE REGION AS MID LEVEL FLOW BACKS
WESTERLY. A QUICK RETURN LOW LEVEL FLOW TO DEVELOP ON THE BACK SIDE
OF THE RETREATING HIGH. WILL HOLD OFF ON ANY WAA PCPN UNTIL SATURDAY
NIGHT.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AREA OF SHOWERS WILL SKIM KDAY AND KCMH/KLCK WITH A BRIEF MVFR
SHOWER POSSIBLE AT KDAY BEFORE DAYBREAK. AREA MOVES ENE AND
A BRIEF LULL IN SHOWERS OVER THE REGION IS FOUND UNTIL ABOUT NOON
WITH MVFR CIGS. SCATTERED SHOWERS IN THE AFTERNOON MAY PRECEDE
THE MAIN BODY OF HEAVIER RAIN WHICH SHOULD ENTER BEFORE NIGHTFALL.
PREVAILING RAIN WITH IFR CIGS/VSBYS AND A POTENTIAL FOR LIFR
CONDITIONS AT TIMES WILL BE FOUND THROUGH THE END OF THE VALID TAF
PERIOD WITH THE EXCEPTION OF A DRY PUNCH NOTED TO BEGIN AT
KCVG/KLUK 4-5Z. VFR SHOWERS WILL STILL BE POSSIBLE IN THE EXPECTED
LULL THAT SHOULD LAST THROUGH DAYBREAK IN MOST LOCATIONS. SOUTH
WINDS OVERNIGHT WILL SEE GUSTS TO 25 AND 30KT.
OUTLOOK...MVFR/IFR CEILINGS AND MVFR VISIBILITIES TO CONTINUE INTO
MONDAY AS A STRONG COLD FRONT MOVES THROUGH THE REGION. GUSTY
SOUTHWEST WINDS AROUND 35 KNOTS LIKELY MONDAY INTO MONDAY NIGHT.
MVFR CEILINGS POSSIBLE MONDAY NIGHT INTO TUESDAY. MVFR/IFR
CONDITIONS POSSIBLE THURSDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...CONIGLIO
NEAR TERM...HICKMAN
SHORT TERM...CONIGLIO/HICKMAN
LONG TERM...AR
AVIATION...FRANKS
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1057 PM CST SAT NOV 22 2014
.UPDATE...
ISSUED AT 940 PM CST SAT NOV 22 2014
STRATUS CONTINUES TO MOVE BACK INTO THE REGION TONIGHT. HRRR AND
RAP SEEM TO HAVE A GOOD HANDLE ON THIS...KEEPING MOST OF THE
STRATUS ALONG AND EAST OF INTERSTATE 29. SIGNAL FOR DENSE FOG IN
THE MODELS IS LESS THAN LAST NIGHT AND CURRENTLY NOT SEEING MUCH
OUT THERE. WILL KEEP FOG IN THE FORECAST...BUT PROBABILITY OF
WIDESPREAD DENSE FOG SEEMS TO BE DECREASING...ALTHOUGH WILL NEED
TO CONTINUE TO MONITOR.
OTHERWISE WATCHING SOME LIGHT PRECIPITATION THAT WILL TRY TO MOVE
ACROSS THE REGION TONIGHT INTO TOMORROW ASSOCIATED WITH A PRETTY
GOOD AREA OF MID LEVEL FRONTOGENESIS. WILL HAVE TO OVERCOME QUITE
A BIT OF DRY AIR IN THE LOW LEVELS...BUT STILL COULD SEE SOME
LIGHT PRECIPITATION WORK FROM WEST TO EAST INTO EARLY TOMORROW
AFTERNOON. DID GO AHEAD AND CHANGE PRECIPITATION TYPE TO ALL RAIN
THOUGH. EXPECT SURFACE TEMPERATURES TO REMAIN ABOVE FREEZING...AND
MODEL SOUNDINGS SUGGEST PLAIN RAIN IS THE MOST LIKELY PRECIPITATION
TYPE. SREF PROBABILITIES ALSO BACK THIS UP...SO FELT COMFORTABLE
REMOVING MENTION OF SNOW. CAN NOT COMPLETELY RULE OUT A FEW FLAKES
MIXED IN...BUT SHOULD MAINLY BE A CHILLY LIGHT RAIN IF ANYTHING.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 415 PM CST SAT NOV 22 2014
ANOTHER DIFFICULT FORECAST IN THE SHORT TERM AS LOW CLOUDS AND
STRATUS STRUGGLING TO ERODE ACROSS THE EASTERN HALF OF THE FORECAST
AREA. WHERE THE STRATUS HAS ERODED...TEMPERATURES HAVE RECOVERED
NICELY IN THE 40S AND 50S...BUT ACROSS THE EAST UNDER THE BLANKET OF
LOW CLOUDS...TEMPERATURES HAVE REMAINED STEADY IN THE 30S. EXPECT
THE EAST TO FILL BACK IN WITH LOW CLOUDS AND FOG TONIGHT...AND MAY
HAVE TO ISSUE A DENSE FOG ADVISORY TONIGHT FOR PORTIONS OF THE
FORECAST AREA. BEST CHANCES APPEAR TO BE ALONG AND EAST OF A LINE
FROM VERMILLION TO MARSHALL AND EAST. EXPECT VISIBILITIES TO
IMPROVE AS SURFACE TROUGH SHIFTS EAST AND WINDS BECOME NORTHWEST
DRYING OUT THE LOW LEVELS. WITH THE PASSAGE OF THE TROUGH...COULD
HAVE A SMALL AMOUNT OF PRECIPITATION WITH STRONG 700 MB
FRONTOGENESIS COINCIDING WITH WEAK DIV Q ALOFT. PRECIP TYPE COULD
BE A REAL CONCERN THROUGH THE MORNING HOURS WITH TEMPERATURES AT
THE SURFACE NEAR FREEZING. TOUGH CALL IN TERMS OF PRECIP
TYPE...FOR NOW...KEPT PRECIP TYPES CONFINED TO RAIN OR SNOW...BUT
COULD BE POTENTIAL FOR FREEZING RAIN WITH WARM DRY LAYER IN THE
LOWEST 2000 FEET OF THE ATMOSPHERE. EXPECT PRECIP TO BE ALL RAIN
AS IT SHIFTS FURTHER EAST INTO LOCATIONS WHERE TEMPERATURES REMAIN
ABOVE FREEZING. HIGH TEMPERATURES A TOUGH CALL ON SUNDAY...WITH
925 HPA TEMPS COOLING FROM NEAR 10C DOWN CLOSER TO 5C BY 0Z
MONDAY. FURTHER BACK TO THE NORTHWEST...925 HPA TEMPS HOVER IN THE
LOWER SINGLE DIGITS LEADING TO A RELATIVELY SMALL DIURNAL
FLUCTUATION UNDER A MOSTLY CLOUDY SKY.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 415 PM CST SAT NOV 22 2014
BY SUNDAY NIGHT...NORTHWEST WINDS INCREASE TO 20 TO 30 MPH WITH
HIGHER GUSTS TO 45 MPH. COLDER AIR BEGINS RUSHING BACK INTO THE
REGION...WITH TEMPERATURES DROPPING BACK BELOW FREEZING IN THE
EVENING AND REACHING THE TEENS AND LOWER 20S BY DAYBREAK MONDAY. AS
THE NORTHERN STREAM UPPER TROUGH DIGS INTO THE NORTHERN PLAINS AND
MERGES WITH THE SOUTHERN STREAM WAVE TO OUR EAST...SOME SCATTERED
LIGHT SNOWFALL WILL TRACK SOUTHEAST ACROSS THE FORECAST
AREA...HOWEVER THE BETTER FORCING REMAINS TO OUR EAST AND WITHOUT A
GREAT DEAL OF MOISTURE...ANY SNOWFALL WILL BE ON THE LIGHT SIDE.
COULD SEE AROUND A HALF INCH TO INCH IN SOUTHWEST MINNESOTA...
OTHERWISE A FEW TENTHS OR TRACE AT BEST. ADDITIONALLY...WITH THE
GUSTY WINDS...THE LIGHT SNOW WILL BLOW AROUND A BIT...BUT AMOUNTS
WILL BE TOO LIGHT FOR ANY BLOWING SNOW MENTION. ANY EXISTING SNOW
PACK SHOULD HAVE ENOUGH OF A CRUST TO NOT CAUSE ANY BLOWING SNOW
ISSUES EITHER.
WITH THE DEEP UPPER LEVEL TROUGH SLIDING ACROSS THE WESTERN GREAT
LAKES AND SHARP RIDGING ALONG THE WEST COAST...UPPER LEVEL NORTHWEST
FLOW SETTLES INTO THE AREA. WHILE NOT PARTICULARLY A COLD
AIRMASS...TEMPERATURES REMAIN BELOW NORMAL IN THE MID 20S TO MID 30S
ON TUESDAY AND WEDNESDAY. MODELS TRACK A CLIPPER WAVE ALONG THE
UPPER FLOW...ALTHOUGH THE TIMING...TRACK AND STRENGTH OF THIS FAST
MOVING WAVE REMAINS IN POOR AGREEMENT. THE GFS IS QUITE A BIT FASTER
THAN THE OTHER MODELS...FOLLOWED BY THE ECMWF THEN THE NAM. BUT IT
SEEMS THE GENERAL CONSENSUS IS FOR THE BEST CHANCE OF LIGHT SNOW IN
OUR NORTHEASTERN COUNTIES ON TUESDAY NIGHT.
UNCERTAINTY FURTHER INCREASES WEDNESDAY AND WEDNESDAY NIGHT AS THE
BAROCLINIC ZONE SETS UP NEAR THE FORECAST AREA AND POTENTIALLY
BECOMES THE FOCUS MECHANISM OF ADDITIONAL LIGHT PRECIPITATION AS
WARM AIR ADVECTION LIFTS INTO CENTRAL SD AND THE MID MISSOURI
VALLEY. CONFIDENCE IS FAIRLY LOW WITH WHERE THIS WILL SET UP...BUT
WILL LEAVE SOME ISOLATED LIGHT SNOWFALL MENTION WEDNESDAY AND
WEDNESDAY NIGHT.
MODELS WAVER WITH BRINGING FURTHER WAVES ALONG THE FLOW...BUT NOT A
LOT OF CONFIDENCE IN THE TIMING. THANKSGIVING LOOKS TO BE THE
COLDEST DAY IN THE EXTENDED WITH HIGHS ONLY IN THE TEENS AND LOWER
20S FOLLOWED BY THURSDAY NIGHT LOWS IN THE SINGLE DIGITS. FRIDAY
TEMPERATURES MODERATE SOME INTO THE UPPER TEENS TO NEAR 30.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY EVENING)
ISSUED AT 1055 PM CST SAT NOV 22 2014
EXPECT MVFR TO IFR CIGS AND VIS ACROSS NORTHWEST IOWA AND ADJACENT
PORTIONS OF SOUTHWEST MINNESOTA TONIGHT...SO INCLUDED MENTION IN THE
KSUX TAF. BASED ON OBS WILL KEEP KSUX MVFR...BUT IFR AND LIFR CIGS
ARE NOT TOO FAR AWAY AND COULD MOVE IN...SO SOMETHING TO WATCH.
COULD SEE SOME DENSE FOG FORM...ALTHOUGH LATEST GUIDANCE SUGGESTS
WIDESPREAD DENSE FOG IS PROBABLY BECOMING LESS LIKELY. AGAIN KFSD
WILL BE NEAR THE EDGE OF THIS STRATUS AND FOG...BUT BASED ON LATEST
MODEL GUIDANCE LEANING TOWARDS THEM STAYING VFR...BUT WILL CONTINUE
TO MONITOR. EXPECT ANY STRATUS TO CLEAR EARLY TO MID MORNING AS A
FRONT SWITCHES WINDS TO THE WEST AND NORTHWEST. COULD BE A LITTLE
LIGHT RAIN AS THE FRONT CROSSES...BUT NOT EXPECTING ANYTHING OF
SIGNIFICANCE AT THIS TIME. WINDS WILL INCREASE BEHIND THE
FRONT...AND BY LATE MORNING AND AFTERNOON EXPECTING GUSTS OF 30 TO
40 KTS TO BE COMMON AND LAST INTO THE OVERNIGHT. ALSO SHOULD SEE
STRATOCU DEVELOPMENT BEHIND THE FRONT IN THE COLD AIR ADVECTION
REGIME...WITH HEIGHTS LIKELY HIGH END MVFR OR LOW END VFR. ALSO
SHOULD BE SCATTERED FLURRIES OR SNOW SHOWERS INTO THE
OVERNIGHT...AND GIVEN THE STRONG WINDS COULD SEE BRIEF PERIODS OF
VISIBILITY REDUCTION...SO WILL HAVE TO WATCH FOR THAT AS WELL.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...CHENARD
SHORT TERM...
LONG TERM...
AVIATION...CHENARD
AREA FORECAST DISCUSSION
NWS AMARILLO TX
302 AM CST SUN NOV 23 2014
.DISCUSSION...
VIGOROUS UPPER LEVEL SHORT WAVE TROUGH CROSSING THE ROCKIES WILL
DRIVE A STRONG CANADIAN COLD FRONT THROUGH THE REGION THIS
MORNING. WINDS ARE EXPECTED TO REACH WIND ADVISORY CRITERIA
WITH THIS FRONT FROM LATE THIS MORNING INTO THE EARLY AFTERNOON.
SURFACE PRESSURE GRADIENT ALONG WITH 850MB AND 700 MB HEIGHT
GRADIENTS ALL POINT TO THE POTENTIAL OF SUSTAINED 35 MPH WINDS
WITH HIGHER GUSTS. HAVE ADDED THE MENTION OF BLOWING DUST WITH
THESE HIGHER WINDS AS WELL. MODELS HAVE ALSO COME IN WETTER WITH THIS
SYSTEM. LATEST TTU WRF AND HRRR MODELS SUGGEST THAT AT LEAST SOME
KIND OF BAND OF PRECIP WILL TRAVERSE THE PANHANDLES TODAY. HAVE GONE
AHEAD AND INCREASED THE POPS TO 30 PERCENT ACROSS THE PANHANDLES.
BELIEVE THAT THE PRECIP COULD BE RAIN OR SNOW. AS THE DAY WEARS ON
THE COLUMN COOLS QUITE A BIT. THE ENTIRE CLOUD LAYER REMAINS BELOW 0
DEGREES CELSIUS AND THERE IS MOISTURE IN THE -10 TO -20 DEGREE
CELSIUS RANGE TO HELP FORM SOME SNOW FLAKES. TEMPERATURES MAY
ACTUALLY HOLD STEADY OR FALL THIS AFTERNOON AS THICKNESSES CRASH. SO
WOULD NOT BE SURPRISED TO SEE SOME SNOW SHOWERS WITH TEMPERATURES IN
THE LOWER 40S.
A FEW SNOW SHOWERS MAY LINGER NEAR THE NEW MEXICO STATE LINE
TONIGHT IN THE BEST UPSLOPE AREA...BUT THEY WILL REMAIN LIGHT.
AFTER TONIGHT THIS SYSTEM MOVES OFF TO OUR EAST AND A NORTHWEST FLOW
ALOFT DOMINATES THE PANHANDLES FOR THE EARLY PART OF THE WEEK.
THE MODELS START TO DIFFER SOMEWHAT BY THANKSGIVING. THE GFS
BROADENS AN UPPER LEVEL RIDGE ACROSS THE SOUTHERN ROCKIES AND
SOUTHERN HIGH PLAINS. MEANWHILE...THE ECMWF TRIES TO CARVE OUT AN
UPPER LEVEL TROUGH FROM SOUTHWEST CANADA INTO THE CENTRAL
PLAINS...WHICH WOULD PUSH ANOTHER CANADIAN COLD FRONT THROUGH THE
AREA BY THANKSGIVING AFTERNOON LEAVING FRIDAY AND SATURDAY COLDER.
THE GFS DOES NOT BRING IN THE COLDER AIR UNTIL NEXT WEEKEND. FOR
NOW HAVE GONE WITH A COMPROMISE WITH THE TEMPERATURES. AT ANY RATE
THE MODELS REMAIN DRY AFTER TONIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMARILLO TX 46 28 51 22 51 / 30 20 0 5 0
BEAVER OK 48 23 53 21 53 / 30 10 0 0 0
BOISE CITY OK 46 21 51 19 52 / 30 20 0 0 0
BORGER TX 53 30 53 25 54 / 30 10 0 0 0
BOYS RANCH TX 49 27 52 22 53 / 30 20 0 5 0
CANYON TX 48 27 54 22 52 / 30 20 0 0 0
CLARENDON TX 52 31 55 28 52 / 30 10 0 0 0
DALHART TX 49 20 53 18 51 / 30 20 0 5 0
GUYMON OK 49 22 50 21 52 / 30 10 0 0 0
HEREFORD TX 49 25 53 21 53 / 30 20 0 0 0
LIPSCOMB TX 47 26 53 24 53 / 30 10 0 0 0
PAMPA TX 45 27 49 24 48 / 30 10 0 0 0
SHAMROCK TX 54 29 57 28 53 / 30 10 0 0 0
WELLINGTON TX 57 31 60 30 54 / 30 10 0 0 0
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...WIND ADVISORY FROM 9 AM THIS MORNING TO 6 PM CST THIS EVENING
FOR THE FOLLOWING ZONES: ARMSTRONG...CARSON...
COLLINGSWORTH...DALLAM...DEAF SMITH...DONLEY...GRAY...
HANSFORD...HARTLEY...HEMPHILL...HUTCHINSON...LIPSCOMB...
MOORE...OCHILTREE...OLDHAM...POTTER...RANDALL...ROBERTS...
SHERMAN...WHEELER.
OK...WIND ADVISORY FROM 9 AM THIS MORNING TO 6 PM CST THIS EVENING
FOR THE FOLLOWING ZONES: BEAVER...CIMARRON...TEXAS.
&&
$$
08/15
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1149 PM CST SAT NOV 22 2014
.AVIATION...
CONVECTION HAS MOVED OFF TO THE EAST AND CONDITIONS ARE RAPIDLY
IMPROVING. FOR THE NEXT COUPLE OF HOURS WINDS IN AUSTIN AND SAN
ANTONIO WILL BE FROM THE NORTH ON THE BACK SIDE OF AN AREA OF LOW
PRESSURE. AFTER ABOUT 07Z WINDS WILL BECOME WESTERLY AND WEAKEN.
SKIES WILL BECOME MAINLY CLEAR AND THE ONLY ISSUE WILL BE THE
WINDS. WIND SPEEDS WILL INCREASE TO 10 TO 15 KTS DAYTIME TOMORROW
AND THEN WEAKEN AND SHIFT TO NORTHWEST AFTER SUNSET.
&&
.PREV DISCUSSION... /ISSUED 938 PM CST SAT NOV 22 2014/
UPDATE... /CLEARING SVR WATCH COUNTIES FROM WEST...CONTINUE FFA/
AS A MINOR THREAT OF SEVERE WEATHER AND FLASH FLOODING CONTINUES
ACROSS SE COUNTIES...MUCH OF THE AREA HAS BEEN UPDATED TO REFLECT
A DECREASING CHANCE OF RAIN AND SEVERE WEATHER. THE FFA THREAT IS
LEFT IN PLACE...BUT MAY HAVE A POTENTIAL OF REMOVAL BEFORE THE END
OF THE EVENING. A FEW RIVERS AND STREAMS...MAINLY THOSE ALONG THE
EASTERN PART OF THE BALCONES ESCARPMENT...ARE OUT OF BANKS. SOME
SECONDARY ROADS WILL LIKELY REMAIN IMPASSABLE FOR A FEW MORE
HOURS. PRELIMINARY HIGHEST 2-DAY RAINFALL TOTALS APPEAR TO BE OUT
OF TRAVIS AND HAYS COUNTIES AT BETWEEN 4 AND 5.5 INCHES.
PREV DISCUSSION... /ISSUED 814 PM CST SAT NOV 22 2014/
UPDATE...
TO EXTEND SEVERE THUNDERSTORM WATCH.
DISCUSSION...
RISK OF SEVERE THUNDERSTORMS WILL CONTINUE WITH A LINE OF
THUNDERSTORMS MOVING TOWARD THE EAST. THE LINE CURRENTLY EXTENDS
FROM SAN ANTONIO TO PLEASANTON TO CROSS. AS THIS LINE MOVES TO THE
EAST THERE WILL BE A RISK FOR THUNDERSTORMS CAPABLE OF PRODUCING
LARGE HAIL AND DAMAGING WINDS. THERE IS ALSO A SLIGHT RISK FOR
TORNADOES. WE HAVE EXTENDED THE SEVERE THUNDERSTORM WATCH TO THE
COUNTIES EAST OF BEXAR AND ALONG AND SOUTH OF I-10.
PREV DISCUSSION... /ISSUED 715 PM CST SAT NOV 22 2014/
UPDATE... /SVR WATCH 557 EXTENSION INTO BEXAR...ATASCOSA/
A PROGRESSIVE SQUALL LINE IS QUICKLY SHIFTING THE SEVERE POTENTIAL
INTO THE SAN ANTONIO METRO AREA. APEX OF A CURVED SQUALL LINE
INCREASES THE POTENTIAL FOR SEVERE ACTIVITY ASSOCIATED WITH CELL
MERGERS AS NEW CONVECTION FORMS EAST OF THE LINE. CELL MERGERS
WILL ALSO BE POSSIBLE OVER PARTS OF ATASCOSA COUNTY BY 8 PM.
EXPECT TO SEE A HEAVY RAIN PRODUCING MCS TAKE SHAPE ONCE THE
MERGED CELLS MOVE EAST OF I-35...WITH DECREASING SEVERE POTENTIAL
BY 10 PM.
PREV DISCUSSION... /ISSUED 607 PM CST SAT NOV 22 2014/
UPDATE... /ISSUANCE OF FFA/
WITH THE MAJORITY OF HI-RES MODELS INDICATING LARGE AREAS OF 1-2
INCH RAINFALL STILL POSSIBLE OVER EASTERN COUNTIES...HAVE ISSUED A
FLASH FLOOD WATCH FOR COUNTIES ALONG AND EAST OF A LLANO TO SAN
ANTONIO LINE AND ALONG AND NORTH OF A SAN ANTONIO TO HALLETTSVILLE
LINE. THE FLASH FLOOD THREAT WILL PROBABLY BE ENHANCED THROUGH 9
PM OVER THE EASTERN HILL COUNTRY INTO AUSTIN METRO WITH SOME
TRAINING CELLS INCREASING FROM LAKE MEDINA TO BURNET. AFTER 9 PM...THE
FOCUS FOR FLOODING SHOULD BEGIN TO SHIFT EAST OF I-35. LCRA
HYDROMET INDICATES SEVERAL REPORTS OF 2 PLUS INCHES OF RAIN HAS
FALLEN STILL WITHIN THE PAST 6 HOURS OVER AREAS IN THE PATHS OF
NEW CONVECTION. ISOLATED MINOR RIVER RISES ARE EXPECTED...BUT
MODERATE FLOOD LEVELS ARE UNLIKELY. THE SEVERE THREAT CONTINUES
FOR MUCH OF THIS EVENING...ESPECIALLY OVER THE RIO GRANDE PLAINS.
HOWEVER...THE SEVERE THREAT SHOULD TREND TOWARD MORE ISOLATED
ACTIVITY LATE THIS EVENING.
PREV DISCUSSION... /ISSUED 349 PM CST SAT NOV 22 2014/
THE RISK OF SEVERE WEATHER AND HEAVY RAIN CONTINUES
THROUGH THIS EVENING...
SHORT TERM (TONIGHT THROUGH SUNDAY NIGHT)...
STRONG STORMS AND HEAVY RAIN WILL CONTINUE TO AFFECT MAINLY THE
EASTERN HALF OF SOUTH CENTRAL TEXAS FOR THE NEXT SEVERAL HOURS.
THE THREAT FOR STRONG TO SEVERE WEATHER STILL EXISTS THROUGH THIS
EVENING. A SECOND ROUND OF SHOWERS AND STORMS CURRENTLY ONGOING
ACROSS THE SERRANIAS DEL BURRO (NORTHEAST MEXICO) IS FORECAST TO
PUSH EASTWARD AND ACROSS MOST OF SOUTH CENTRAL TEXAS THIS EVENING.
THE HRRR AND TECH-TECH HIRES MODELS DEVELOP AN MCS AROUND 23Z/5 PM
THIS AFTERNOON WHILE A LINE OF SHOWERS AND STORMS FORM AHEAD OF A
SURFACE CONVERGENCE ZONE (WARM SECTOR). IF THIS SCENARIO PANS
OUT...STRONG TO SEVERE STORMS ARE POSSIBLE ACROSS THE RIO
GRANDE...ESPECIALLY ALONG AND WEST OF ROCKSPRINGS TO HONDO TO
PEARSALL LINE. A SEVERE THUNDERSTORM WATCH IS IN EFFECT THROUGH 10
PM TONIGHT FOR THE AREA ABOVE MENTIONED. MAIN WEATHER THREATS WILL
BE LARGE HAIL AND DAMAGING WINDS. CAN`T RULE OUT AN ISOLATED
TORNADO OR TWO. SOME OF THESE STRONG STORMS WILL PRODUCE HEAVY
DOWNPOURS WITH RAINFALL ACCUMULATIONS UP TO ONE INCH PER HOUR.
THE MCS IS FORECAST TO COMBINE WITH THE SHOWERS AND STORMS
EXPECTED TO FORM ALONG THE CONVERGENCE ZONE AND MOVE EAST IN A
LINEAR FASHION...AFFECTING THE I-35 CORRIDOR AROUND 8 OR 9 PM THIS
EVENING. BY 9 PM...THE SYSTEM IS LIKELY TO TRANSITION TO A HEAVY
RAIN PRODUCER WITH STRONGER STORMS CAPABLE OF PRODUCING LARGE
HAIL. THE LINE OF STORMS WILL QUICKLY PUSH TO THE EAST BY MIDNIGHT
TONIGHT WITH RAIN CHANCES COMING TO AN END ACROSS THE ENTIRE AREA
BY 2 OR 3 AM SUNDAY. NEW RAINFALL AMOUNTS FOR THE TONIGHT PERIOD
COULD RANGE FROM 1 TO 2 INCHES AND UP TO 3 INCHES IN ISOLATED
PLACES.
ON SUNDAY...EXPECT MOSTLY SUNNY/CLEAR SKIES ACROSS SOUTH CENTRAL
TEXAS WITH BREEZY CONDITIONS. A PACIFIC COLD FRONT WILL PUSH
ACROSS THE REGION SUNDAY NIGHT INTO MONDAY.
LONG TERM (MONDAY THROUGH SATURDAY)...
THE WEATHER IS EXPECTED TO BE FAIRLY QUIET FOR MUCH OF NEXT WEEK. A
WEAK FRONT WILL MOVE THROUGH THE AREA OVERNIGHT SUNDAY. THIS FRONT
IS IN RESPONSE TO AN UPPER LEVEL TROUGH MOVING THROUGH THE PLAINS.
THE WEATHER FOR THANKSGIVING SHOULD BE PRETTY SEASONAL WITH HIGHS
IN THE 60S AND LOWS IN THE 30S/40S.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 55 78 45 64 40 / 50 0 - - -
AUSTIN BERGSTROM INTL AIRPORT 54 77 43 64 37 / 70 0 - - -
NEW BRAUNFELS MUNI AIRPORT 55 79 45 66 40 / 50 0 - - -
BURNET MUNI AIRPORT 52 75 42 62 38 / 40 0 - - -
DEL RIO INTL AIRPORT 50 78 46 65 38 / 10 0 - - -
GEORGETOWN MUNI AIRPORT 54 75 43 62 38 / 50 0 - - -
HONDO MUNI AIRPORT 49 77 42 65 37 / 20 0 - - -
SAN MARCOS MUNI AIRPORT 53 78 44 65 39 / 50 0 - - -
LA GRANGE - FAYETTE REGIONAL 57 78 46 64 40 / 90 0 - - -
SAN ANTONIO INTL AIRPORT 54 78 46 66 41 / 40 0 - - -
STINSON MUNI AIRPORT 54 79 46 66 41 / 20 0 - - -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL MIDNIGHT CST TONIGHT FOR THE FOLLOWING
COUNTIES: BASTROP...BEXAR...BLANCO...BURNET...CALDWELL...COMAL...
FAYETTE...GONZALES...GUADALUPE...HAYS...LAVACA...LEE...LLANO...
TRAVIS...WILLIAMSON.
&&
$$
MESOSCALE/AVIATION...05
SYNOPTIC/GRIDS...18
PUBLIC SERVICE/DATA COLLECTION...30
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1140 PM CST SAT NOV 22 2014
.DISCUSSION...
06Z TAF DISCUSSION IN AVIATION SECTION...
&&
.AVIATION...
MAIN LINE OF STORMS STRETCHES FROM KGLS OUT INTO THE GULF AND
SHOULD BE MOVE OUT OF THE AREA OVER THE NEXT HOUR OR TWO. A SECOND
WEAKER LINE OF STORMS WAS LOCATED WEST OF KUTS/KCXO AND THEN
MOVING TOWARDS KUTS/KCXO/KIAH. WILL KEEP MENTION OF TSRA IN TAFS
THROUGH 08Z TO ACCOUNT FOR THESE STORMS. OVERALL STORMS SHOULD BE
MOVING OUT OF THE AREA 08Z-12Z WITH CIGS IMPROVING. MODELS SHOW
DENSE FOG DEVELOPING AFTER 08Z BUT DO NOT SEE THIS HAPPENING WITH
SKIES SLOW TO CLEAR AND WINDS REMAINING. WINDS TURN SW/W DURING
THE DAY WITH SOME GOOD GUSTS. COLD FRONT SHOULD REACH AREA BETWEEN
03Z/06Z MONDAY.
39
&&
.PREV DISCUSSION... /ISSUED 1119 PM CST SAT NOV 22 2014/
DISCUSSION...
UPDATED POPS AND WEATHER...MAINLY TO TAKE OUT THE SEVERE MENTION
AND TO TWEAK THE OVERNIGHT WEATHER REGARDING THE TIMING OF THE END
OF THE RAIN CHANCES.
40
PREV DISCUSSION... /ISSUED 911 PM CST SAT NOV 22 2014/
DISCUSSION...
THE UPPER TROUGH WAS SWINGING THROUGH THE SOUTHERN PART OF THE
STATE AT 845 PM...WITH VERY GOOD DIFFLUENCE NOTED AT 300 MB
OVERHEAD OF SE TX. WITH A STATIONARY FRONT JUST WEST OF KCLL AND
CROCKETT...AM EXPECTING WIDESPREAD RAIN AND THUNDERSTORMS ACROSS
THE FORECAST AREA THROUGH MIDNIGHT. LIKE THE 01Z HRRR AND THE 00Z
NAM12 WHICH PUSHES THE BEST CHANCES FOR THUNDERSTORMS EAST OF
INTERSTATE 45 BETWEEN MIDNIGHT AND 2 AM. THIS TIMING WILL BE TIED
TO THE DEVELOPMENT AND EVOLUTION OF THE TWO DOMINATE LINES OF
CONVECTION WHICH WERE FORMING AT 9 PM. ONE WAS ALONG THE
INTERSTATE 35 CORRIDOR AND THE OTHER FROM NEAR FRIENDSWOOD AND
PEARLAND SOUTH TO JUST OFF THE MID TX COAST.
AGREE WITH SPC WITH THE UPDATED SLIGHT RISK FOR SEVERE STORMS
BEING MAINLY ALONG AND SOUTH OF A LINE FROM NEAR COLLEGE STATION
TO DAYTON IN SOUTHERN LIBERTY COUNTY. THIS MEANS THAT ISOLATED
SEVERE STORMS ARE POSSIBLE WITH THE MAIN THREATS STRONG WINDS AND
SMALL HAIL. WHERE TRAINING OF STORMS OCCUR...MINOR FLOODING IS
POSSIBLE. SOME LOCATIONS ACROSS WASHINGTON...GRIMES...AND INTO
WALKER COUNTIES HAVE ALREADY RECEIVED UP TO 3 INCHES OF RAIN.
WILL UPDATE THE FORECAST TO TWEAK THE BETTER RAIN CHANCES TO PAST
MIDNIGHT.
40
PREV DISCUSSION... /ISSUED 603 PM CST SAT NOV 22 2014/
DISCUSSION...
00Z TAF DISCUSSION IN AVIATION SECTION.
AVIATION...
WATER VAPOR IMAGERY SHOWS LEAD SHORT WAVE AHEAD OF MAIN UPPER LOW
OVER BIG BEND/RIO GRANDE VALLEY MOVING ACROSS SE TX. SFC ANALYSIS
HAS WARM FRONT DIAGONAL FROM NORTH OF KAUS TO KCLL DOWN TO THE
GOLDEN TRIANGLE. SECOND ROUND OF CONVECTION BASED ON HRRR/RAP
TRENDS IS EXPECTED TO PUSH ACROSS THE AREA AROUND 06Z. ALREADY
SEEING THE START OF A SQUALL LINE DEVELOPING UNDER UPPER LOW OVER
WEST HILL COUNTRY.
KCLL/KUTS/KCXO...FAIRLY STOUT CLUSTER OF TSRA W OF KUTS AND E OF
KCLL WILL MOVE THROUGH THE AREA OVER THE NEXT HR OR TWO. MAIN
IMPACT WILL BE FOR KUTS WITH CIGS DROPPING TO IFR WITH GUSTY
WINDS. THINK SQUALL LINE OF STORMS WILL REACH THESE TERMINALS
03-04Z AND MOVING OUT PAST 06-07Z. CIGS AND OVERALL AVIATION
CONDITIONS SHOULD IMPROVE AFTER THAT WITH SW WINDS TOMORROW.
KIAH/KHOU/KSGR...CURRENT AREA OF SHRA AND ISO TSRA WILL BE MOVING
THROUGH HOUSTON TERMINALS OVER THE NEXT HR. STORMS MAY DROP CIGS
TO IFR WITH SOME LIMITED VSBY AND GUSTY WINDS. SHOULD HAVE A BREAK
FOR A FEW HRS AHEAD OF NEXT ROUND OF STORMS WHICH SHOULD BE A
DEVELOPING SQUALL LINE. LOOK FOR STORMS TO REACH HOUSTON TERMINALS
05-07Z SO ADDED TEMPO FOR +TSRA AND GUSTY WINDS. ONCE LINE MOVES
THROUGH EXPECT CIGS TO IMPROVE ALONG WITH OVERALL AVIATION WEATHER
CONDITIONS. VFR TOMORROW WITH SW WINDS.
KLBX/KGLS...LINE OF SHRA CURRENTLY MOVING THROUGH TERMINALS SHOULD
BE SHORT LIVED AND MOVE OUT WITHIN THE NEXT HR. MAIN CONCERN WILL
BE LATER TONIGHT FROM 05-08Z WHEN A LINE OF STORMS MOVES THROUGH
THE AREA. MENTION +TSRA AND GUSTY WINDS FOR POSSIBLE SQUALL LINE
THAT WILL PUSH THROUGH. CIGS AND OVERALL CONDITIONS WILL IMPROVE
AFTER 08-09Z. VFR TOMORROW WITH SW WINDS.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 57 78 45 64 40 / 90 10 0 0 0
HOUSTON (IAH) 59 80 49 65 41 / 90 10 0 0 0
GALVESTON (GLS) 65 76 56 64 50 / 90 10 0 0 0
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 6 AM CST SUNDAY FOR
THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA
SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO
FREEPORT OUT 20 NM.
SMALL CRAFT ADVISORY UNTIL 9 AM CST SUNDAY FOR THE FOLLOWING
ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL
20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO
60 NM.
&&
$$
DISCUSSION...40
AVIATION/MARINE...39
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1119 PM CST SAT NOV 22 2014
.DISCUSSION...
UPDATED POPS AND WEATHER...MAINLY TO TAKE OUT THE SEVERE MENTION
AND TO TWEAK THE OVERNIGHT WEATHER REGARDING THE TIMING OF THE END
OF THE RAIN CHANCES.
40
&&
.PREV DISCUSSION... /ISSUED 911 PM CST SAT NOV 22 2014/
DISCUSSION...
THE UPPER TROUGH WAS SWINGING THROUGH THE SOUTHERN PART OF THE
STATE AT 845 PM...WITH VERY GOOD DIFFLUENCE NOTED AT 300 MB
OVERHEAD OF SE TX. WITH A STATIONARY FRONT JUST WEST OF KCLL AND
CROCKETT...AM EXPECTING WIDESPREAD RAIN AND THUNDERSTORMS ACROSS
THE FORECAST AREA THROUGH MIDNIGHT. LIKE THE 01Z HRRR AND THE 00Z
NAM12 WHICH PUSHES THE BEST CHANCES FOR THUNDERSTORMS EAST OF
INTERSTATE 45 BETWEEN MIDNIGHT AND 2 AM. THIS TIMING WILL BE TIED
TO THE DEVELOPMENT AND EVOLUTION OF THE TWO DOMINATE LINES OF
CONVECTION WHICH WERE FORMING AT 9 PM. ONE WAS ALONG THE
INTERSTATE 35 CORRIDOR AND THE OTHER FROM NEAR FRIENDSWOOD AND
PEARLAND SOUTH TO JUST OFF THE MID TX COAST.
AGREE WITH SPC WITH THE UPDATED SLIGHT RISK FOR SEVERE STORMS
BEING MAINLY ALONG AND SOUTH OF A LINE FROM NEAR COLLEGE STATION
TO DAYTON IN SOUTHERN LIBERTY COUNTY. THIS MEANS THAT ISOLATED
SEVERE STORMS ARE POSSIBLE WITH THE MAIN THREATS STRONG WINDS AND
SMALL HAIL. WHERE TRAINING OF STORMS OCCUR...MINOR FLOODING IS
POSSIBLE. SOME LOCATIONS ACROSS WASHINGTON...GRIMES...AND INTO
WALKER COUNTIES HAVE ALREADY RECEIVED UP TO 3 INCHES OF RAIN.
WILL UPDATE THE FORECAST TO TWEAK THE BETTER RAIN CHANCES TO PAST
MIDNIGHT.
40
PREV DISCUSSION... /ISSUED 603 PM CST SAT NOV 22 2014/
DISCUSSION...
00Z TAF DISCUSSION IN AVIATION SECTION.
AVIATION...
WATER VAPOR IMAGERY SHOWS LEAD SHORT WAVE AHEAD OF MAIN UPPER LOW
OVER BIG BEND/RIO GRANDE VALLEY MOVING ACROSS SE TX. SFC ANALYSIS
HAS WARM FRONT DIAGONAL FROM NORTH OF KAUS TO KCLL DOWN TO THE
GOLDEN TRIANGLE. SECOND ROUND OF CONVECTION BASED ON HRRR/RAP
TRENDS IS EXPECTED TO PUSH ACROSS THE AREA AROUND 06Z. ALREADY
SEEING THE START OF A SQUALL LINE DEVELOPING UNDER UPPER LOW OVER
WEST HILL COUNTRY.
KCLL/KUTS/KCXO...FAIRLY STOUT CLUSTER OF TSRA W OF KUTS AND E OF
KCLL WILL MOVE THROUGH THE AREA OVER THE NEXT HR OR TWO. MAIN
IMPACT WILL BE FOR KUTS WITH CIGS DROPPING TO IFR WITH GUSTY
WINDS. THINK SQUALL LINE OF STORMS WILL REACH THESE TERMINALS
03-04Z AND MOVING OUT PAST 06-07Z. CIGS AND OVERALL AVIATION
CONDITIONS SHOULD IMPROVE AFTER THAT WITH SW WINDS TOMORROW.
KIAH/KHOU/KSGR...CURRENT AREA OF SHRA AND ISO TSRA WILL BE MOVING
THROUGH HOUSTON TERMINALS OVER THE NEXT HR. STORMS MAY DROP CIGS
TO IFR WITH SOME LIMITED VSBY AND GUSTY WINDS. SHOULD HAVE A BREAK
FOR A FEW HRS AHEAD OF NEXT ROUND OF STORMS WHICH SHOULD BE A
DEVELOPING SQUALL LINE. LOOK FOR STORMS TO REACH HOUSTON TERMINALS
05-07Z SO ADDED TEMPO FOR +TSRA AND GUSTY WINDS. ONCE LINE MOVES
THROUGH EXPECT CIGS TO IMPROVE ALONG WITH OVERALL AVIATION WEATHER
CONDITIONS. VFR TOMORROW WITH SW WINDS.
KLBX/KGLS...LINE OF SHRA CURRENTLY MOVING THROUGH TERMINALS SHOULD
BE SHORT LIVED AND MOVE OUT WITHIN THE NEXT HR. MAIN CONCERN WILL
BE LATER TONIGHT FROM 05-08Z WHEN A LINE OF STORMS MOVES THROUGH
THE AREA. MENTION +TSRA AND GUSTY WINDS FOR POSSIBLE SQUALL LINE
THAT WILL PUSH THROUGH. CIGS AND OVERALL CONDITIONS WILL IMPROVE
AFTER 08-09Z. VFR TOMORROW WITH SW WINDS.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 57 78 45 64 40 / 90 10 0 0 0
HOUSTON (IAH) 59 80 49 65 41 / 90 10 0 0 0
GALVESTON (GLS) 65 76 56 64 50 / 90 10 0 0 0
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 6 AM CST SUNDAY FOR
THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA
SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO
FREEPORT OUT 20 NM.
SMALL CRAFT ADVISORY UNTIL 9 AM CST SUNDAY FOR THE FOLLOWING
ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL
20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO
60 NM.
&&
$$
DISCUSSION...40
AVIATION/MARINE...39
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1111 PM CST SAT NOV 22 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 313 PM CST SAT NOV 22 2014
CURRENTLY AS OF 21Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED A POWERFUL TROUGH OVER THE PACIFIC NORTHWEST...NOTED
BY A 155 KT JET NEAR 300MB ON THE 12Z MEDFORD OREGON RAOB. OTHER
FEATURES OF NOTE WERE AN UPPER LOW OVER THE BIG BEND REGION OF TEXAS
AND AN UPPER RIDGE OVER THE DAKOTAS AND MN. BELOW THE UPPER
RIDGE...WEST TO SOUTHWEST WINDS OF 20-30 KT FROM 925-850MB PER
PROFILER/VWP DATA HAS BEEN ADVECTING WARMER AIR INTO THE REGION.
925MB TEMPS HAVE RISEN FROM -1 TO 2C AT 12Z TO 2-6C AT 21Z.
HOWEVER...TAMDAR SOUNDINGS SHOW MUCH OF THIS WARMING HAS BEEN
STRENGTHENING A STRONG LOW LEVEL INVERSION...TRAPPING MOISTURE
ADVECTING NORTHWARD ON SOUTHERLY WINDS. DEWPOINTS PRESENTLY RANGE IN
THE 30S TO LOW 40S ACROSS THE FORECAST AREA...BUT 40S TO MID 50S
WERE LURKING ACROSS CENTRAL AND SOUTHERN IOWA. THE INCREASED
WARMING AND MOISTURE AT THE SURFACE HAS ALSO ALLOWED THE SNOWPACK TO
BEGIN TO WARM AND MELT...ADDING ADDITIONAL MOISTURE. WE HAVE SEEN
DENSE FOG EARLIER IN THE DAY...BUT DAYTIME MIXING PLUS WARMER AIR
COMING UP FROM THE SOUTH HAS HELPED TO RAISE VISIBILITIES FOR NOW.
FOR TONIGHT...IMPRESSIVE SURFACE TO 925MB WARM AND MOIST AIR
ADVECTION REMAINS PROGGED TO OCCUR ACROSS THE FORECAST AREA...AIDED
BY THE 925MB WINDS INCREASING TO 30-40 KT. 925MB TEMPS AND
DEWPOINTS BY 12Z SUNDAY CLIMB TO 8-10C...WITH MUCH OF THE JUMP
HAPPENING BETWEEN 00-06Z. THESE DEWPOINTS ARE 2-3 STANDARD
DEVIATIONS ABOVE NORMAL. HAD TO DO SOME MAJOR TEMP/DEWPOINT
ADJUSTMENTS TO HANDLE THIS WARM/MOIST AIR ADVECTION...FOLLOWING
MORE OF THE ECMWF/CANADIAN WHICH ARE NOT AFFECTED AS MUCH BY
SNOWPACK LIKE THE NAM IS. WITH ALL OF THIS WARMING AND MOISTURE
COMING ACROSS THE SNOWPACK...ANTICIPATE FAIRLY RAPID MELTING...
THROWING MORE MOISTURE INTO THE BOUNDARY LAYER. GIVEN AN
INVERSION HOLDING IN PLACE BETWEEN 850-900MB THIS EVENING...BELIEVE
WE SHOULD GET MORE FOG TO DEVELOP...POSSIBLY DENSE...SIMILAR TO WHAT
IS GOING ON RIGHT NOW IN SOUTH CENTRAL IA ON I-35 ON THE NOSE OF
THE MOISTURE SURGE. CONSIDERED GOING WITH AN ADVISORY...BUT
AFTERNOON TRENDS HAS REDUCED CONFIDENCE. ADVISORIES ARE STILL
POSSIBLE...THOUGH. OVERNIGHT...ALL THE FOG COULD DISSIPATE AS
THAT INVERSION WEAKENS...AS INDICATED IN RAP/HIRESARW VISIBILITY
FORECASTS. IN FACT...WE SHOULD HAVE THE AIRMASS OVER MISSOURI IN
PLACE WHICH FEATURES NO VISIBILITY RESTRICTION. SINCE THERE STILL
IS SNOWPACK...HAVE KEPT SOME FOG MENTION...BUT WE MAY NOT HAVE
MUCH SNOWPACK EXCEPT IN OUR NORTH BY THE TIME 12Z ROLLS AROUND.
ALONG WITH THE FOG...THE STRONG INCREASE OF LOW LEVEL MOISTURE IS
LIKELY TO LEAD TO AREAS- WIDESPREAD DRIZZLE...ESPECIALLY
OVERNIGHT.
ON SUNDAY...GOOD MODEL CONSENSUS EXISTS FOR DEEP TROUGHING TO FORM
ACROSS THE PLAINS BY 00Z...WHICH HELPS TO PULL NORTHEASTWARD THE
UPPER LOW NEAR TEXAS INTO SOUTHERN ILLINOIS. THE 22.12Z NAM IS THE
ONLY MODEL WHICH DOESNT PULL THE UPPER LOW NORTHEASTWARD...WHICH
APPEARS TO BE AN OUTLIER AND HAS BEEN DISCOUNTED. WITH THE APPROACH
OF BOTH THE UPPER TROUGH AND LOW IN THE AFTERNOON...DPVA FOR
VERTICAL MOTION INCREASES. THIS VERTICAL MOTION COMBINED WITH
PRECIPITABLE WATER CLIMBING TO 0.75-1 INCH...HIGHEST OVER THE
SOUTHEAST HALF OF THE FORECAST AREA...WILL LEAD TO AN INCREASE IN
SHOWER ACTIVITY...ESPECIALLY IN THE AFTERNOON. NOTE THAT THERE ARE
SIGNS FOR A FRONTOGENETIC BAND TO FORM STRETCHING SOUTHWEST TO
NORTHEAST ACROSS THE FORECAST AREA...WHICH MAY LEAD TO LESS
PRECIPITATION OVER THE FAR NORTHWEST SIDE OF THE FORECAST AREA.
OTHERWISE...ANY FOG FROM TONIGHT LOOKS TO DISSIPATE WEST TO EAST
THROUGH THE AFTERNOON...IN RESPONSE TO A COLD FRONT COMING INTO THE
WESTERN FORECAST AREA AND THE RAIN MOVING IN.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 313 PM CST SAT NOV 22 2014
SUNDAY NIGHT AND MONDAY...THIS PERIOD IS BECOMING MORE INTERESTING.
THERE ARE SIGNS IN THE 22.12Z GFS AND CANADIAN OF PHASING TAKING
PLACE...BETWEEN THE OVERALL UPPER TROUGH ACROSS THE PLAINS AND THE
CURRENT STRONG JET STREAK AT MEDFORD OREGON LIFTING INTO THE OHIO
VALLEY. THE GFS EVEN TAKES IT ONCE STEP FURTHER AND PHASES IN THE
TEXAS UPPER LOW. THE RESULT OF THE PHASING IS RAPID DEEPENING OF A
SURFACE LOW BETWEEN 00-12Z MONDAY MARCHING FROM MISSOURI TO NORTHERN
LAKE MICHIGAN. PRESSURES FALL FROM THE UPPER 980S TO LOW 970S OR
UPPER 960S MB. THE 22.09Z SREF NMMB MEMBERS AND SOME OF THE
CANADIAN ENSEMBLES ARE ALSO QUITE DEEP...EVEN MORESO THAN THE
GFS/CANADIAN. THESE DEEPER MODELS WOULD RESULT IN A TROWAL
OVER THE FORECAST AREA...LEADING TO A HEAVY SNOW BAND AND STRONG
WINDS. ALTHOUGH THERE HAS BEEN A TREND OF DEEPENING IN THE
AFOREMENTIONED MODELS...THE 22.12Z ECMWF REMAINS CONSISTENT IN A
MORE PROGRESSIVE/LESS PHASED SCENARIO. THE MODEL STILL HAS SNOW FOR
THE FORECAST AREA AFTER SOME EVENING RAIN...BUT THE F-GEN BAND IS
NOT NEARLY AS IMPRESSIVE. GIVEN THE CONSISTENCY IN THE ECMWF
AND THE MODEL BEING GENERALLY ONE OF THE BEST AT SYNOPTIC
VERIFICATION...FEEL IT IS DIFFICULT TO JUMP ON THE DEEP SCENARIOS
YET. THUS...THE FORECAST FOR SUNDAY NIGHT/MONDAY REMAINS LARGELY
UNCHANGED. DID BACK OFF THE BLOWING SNOW A BIT SINCE THE SNOWPACK
WILL BE GONE...ALLOWING ANY FALLING SNOW TO ACCUMULATE IN DITCHES
AND THUS LIMIT BLOWING. TEMPERATURE WISE...EXPECT A CONTINUOUS
FALLING TREND FROM SUNDAY NIGHT THROUGH MONDAY.
SNOW SHOULD GRADUALLY TAPER OFF MONDAY NIGHT AS THE LOW LIFTS
OFF TO THE NORTHEAST...BUT CONTINUED COLD AIR ADVECTION IS
ADVERTISED. 925MB TEMPS PLUNGE TO -10 TO -12C...WHICH SHOULD BRING
TEMPS DOWN INTO THE TEENS. TUESDAY FINALLY LOOKS LIKE A DRY
DAY...ASSOCIATED WITH SURFACE RIDGING COMING ACROSS AND AHEAD OF A
POTENT SHORTWAVE DROPPING INTO THE DAKOTAS. PRECIPITABLE WATER IS
QUITE DRY TOO...AROUND 0.2 OF AN INCH...WHICH SHOULD ALLOW ANY LOW
CLOUDS TO CLEAR TUESDAY MORNING. MORE HIGH CLOUDS ARE LIKELY TO
ARRIVE IN THE AFTERNOON...THOUGH. WITH 925MB TEMPS OF -8 TO -10C AT
18Z...HIGHS ONLY LOOK TO TOP OUT IN THE 20S.
TUESDAY NIGHT AND WEDNESDAY COULD BE INTERESTING AS WELL WITH THE
22.12Z ECMWF REMAINING CONSISTENT IN DRIVING A STORM SYSTEM
FROM THE DAKOTAS THROUGH THE REGION. THE 22.12Z/18Z NAM ARE SIMILAR
TOO...THOUGH THERE REALLY IS NO RESEMBLANCE OF THE SYSTEM IN THE
22.12Z GFS. THE 22.12Z CANADIAN IS LIKE A WEAKER NAM/ECMWF. SHOULD
THE ECMWF/NAM VERIFY...WE COULD BE LOOKING AT A 1-2 INCH
SNOWFALL...WHICH COULD IMPACT THANKSGIVING TRAVEL. FOR NOW HAVE TO
KEEP THE CHANCES LOWER...20-40...UNTIL BETTER MODEL AGREEMENT OCCURS.
HOWEVER WEDNESDAY PANS OUT...GOOD MODEL AGREEMENT EXISTS FOR ANOTHER
COLD SURGE TO DIVE INTO THE REGION FOR THANKSGIVING. 925MB TEMPS OF
-14 TO -16C ARE PROGGED...WHICH WOULD RESULT IN HIGHS ONLY IN THE
MID TEENS TO LOW 20S AT BEST. THIS COLD AIR LOOKS TO LINGER INTO THE
EARLY PART OF THE WEEKEND AS CANADIAN HIGH PRESSURE BUILDS IN.
GENERALLY CONDITIONS SHOULD BE DRY...THOUGH CANNOT RULE OUT A FEW
LIGHT SNOW PERIODS THAT DO NOT ACCUMULATE UP TO MUCH.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY TONIGHT)
ISSUED AT 1111 PM CST SAT NOV 22 2014
VSBYS HAVE BEEN VERY CHALLENGING TONIGHT...AND WILL LIKELY STAY THIS
WAY THROUGH SUNDAY. VARIABILITY AND MULTIPLE WEATHER ELEMENTS ARE
KEEPING FORECAST CONFIDENCE SHAKY IN HOW LOW VSBYS WILL GO...AND HOW
LONG THEY WILL STAY THERE. DON/T THINK THEY WILL IMPROVE OUT OF
MVFR...AND LIKELY STAY IFR FOR A BULK OF THE NEXT 24
HOURS...ESPECIALLY AT KRST. LIFR ALSO A GOOD BET THROUGH THE
OVERNIGHT HOURS.
AS FOR DRIZZLE. STILL SIGNALS IN THE MODELS FOR LIFT THROUGH THE
STRATUS LAYER...WHICH SHOULD LEAD TO AREAS OF -DZ. THIS SHOULD HANG
AROUND THROUGH SUNDAY MORNING...WITH AN AREA OF RAIN THEN ADVANCING
NORTHEAST OUT OF IA AS AN AREA OF LOW PRESSURE TAKES AIM ON THE
REGION. LOOKING FOR A WIND SHIFT TO THE NORTHEAST AS THE LOW MOVES
IN/SLIDES EAST...AND A SIGNIFICANT INCREASE IN WIND SPEED FOR SUNDAY
EVENING.
FOR CIGS...GOING TO KEEP THEM UNDER 1KFT FOR NOW. BUFKIT SOUNDINGS
VIA ALL MODELS DON/T BUDGE ON THE LOW LEVEL SATURATION.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...DENSE FOG ADVISORY UNTIL 8 AM CST SUNDAY FOR WIZ017-029-032>034.
MN...DENSE FOG ADVISORY UNTIL 8 AM CST SUNDAY FOR MNZ079.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM....AJ
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS PUEBLO CO
454 AM MST SUN NOV 23 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 454 AM MST SUN NOV 23 2014
...SNOW CONTINUES FOR THE MOUNTAINS TODAY...QUICK BURST OF RAIN AND
SNOW SHOWERS FOR PORTIONS OF THE SE PLAINS THIS MORNING...
UPPER TROF IS MOVING THROUGH WESTERN CO WITH HEAVY SNOW FALLING
ALONG THE CONTDVD BASED ON WEB CAMS. HAVE EVEN SEEN PERIODS OF
MODERATE SNOW ACROSS NORTHERN PORTIONS OF THE SAN LUIS VALLEY AT
SAGUACHE AND JUST SOUTH VILLA GROVE IN CDOT CAMS. MEANWHILE...COLD
FRONT HAS CROSSED THE PALMER DIVIDE AND STARTING TO SEE SNOW FILL IN
ACROSS EL PASO COUNTY AS OF 4 AM.
AS UPPER TROF CONTINUES TO MOVE FROM NORTHWEST TO SOUTHEAST ACROSS
COLORADO THIS MORNING...SHOULD SEE RAIN/SNOW SPREAD SOUTHEASTWARD
ACROSS THE PLAINS. MODELS ARE A LOT HEAVIER HANDED WITH
PRECIPITATION ACROSS THE PLAINS THAN THE RUNS FROM LAST NIGHT...AND
THAT LOOKS REASONABLE AS THE UPPER TROF LOOKS A LITTLE SHARPER...AND
WINDS BEHIND THE FRONT LOOK MORE NORTHERLY...AND EVEN A TAD
NORTHEASTERLY THIS MORNING. COLD FRONT SHOULD RACE THROUGH THE
SOUTHEAST PLAINS BY 12-13Z...WITH STRONG NORTH WINDS GUSTING TO 40
MPH AT TIMES. RAIN AND SNOW SHOWERS RACE SOUTHWARD BEHIND THE
FRONT...WITH PRECIPITATION MOST WIDESPREAD ACROSS THE PALMER DIVIDE
THROUGH 15Z...THEN ACROSS THE NRN RATON RIDGE AND LOWER EAST FACING
SLOPES OF THE WETS AND SANGRES THROUGH ROUGHLY 18Z. NAM12 AND
ESPECIALLY ITS 06Z RUN HAS REALLY COME IN HOT WITH SNOWFALL AMOUNTS
FOR THE SE MTS...INDICATING 5-10 INCHES ACROSS WESTERN
HUERFANO...SOUTHERN CUSTER AND WESTERN LAS ANIMAS COUNTIES THROUGH
THIS AFTERNOON. GFS SHOWS GENERALLY 2-4 INCHES. RAP13 HAS AROUND 2-
4 INCHES ACROSS NRN EL PASO...AND 1-6 ACROSS THE SE MTS/SRN I-25
CORRIDOR. WITH LINGERING INSTABILITY THROUGH THE AFTERNOON...HIGH
RES MODELS ARE PROBABLY CORRECT IN KEEPING CONVECTIVE BANDS OF SNOW
SHOWERS GOING THROUGH THE AFTERNOON IN AND NEAR THE MOUNTAINS. ONCE
THE MAIN UPPER LIFT MOVES EAST OF THE AREA AFTER 18Z...AREAL
COVERAGE OF SHOWERS SHOULD DECREASE CONSIDERABLY. THAT SAID...HAVE
SEEN CASES LIKE THIS WHERE A PERSISTENT NARROW BAND CAN ACCUMULATE
LOCALLY HEAVY AMOUNTS OF SNOW...WHILE A COUPLE MILES EITHER SIDE GET
NEXT TO NOTHING. SO THE CONVECTIVE WILD CARD WILL BE A CHALLENGE
WITH SNOWFALL AMOUNTS TODAY. EITHER WAY...NAM12 SEEMS TO BE
SUFFERING FROM TOO MUCH CONVECTION IN THE MODEL RESULTING IN AMOUNTS
THAT LOOK TOO HEAVY AND WIDESPREAD. HAVE TRENDED GRIDS TOWARDS A
RAP AND HRRR BLEND FOR NOW.
MEANWHILE...SNOW WILL CONTINUE TO FALL HEAVY ALONG THE CONTINENTAL
DIVIDE THROUGH THE MORNING BEFORE TAILING BACK SOME DURING THE
AFTERNOON AS UPPER FORCING WEAKENS. NORTHWEST FLOW WILL KEEP
OROGRAPHIC SNOW CONTINUING ACROSS THE CENTRAL MOUNTAINS THROUGH
TONIGHT...BUT ACCUMULATIONS REMAIN ON THE LIGHTER SIDE UNTIL THE
NEXT WAVE MOVES IN LATE TONIGHT AND CONTINUES INTO MONDAY. CURRENT
SET OF HEADLINES PARES OUT THE SOUTHWEST MOUNTAINS AT 5 PM AND THE
LOWER ELEVATIONS OF LAKE COUNTY AND WESTERN CHAFFEE COUNTY BY 11 PM
THIS EVENING. SUSPECT THESE MAY BE ABLE TO BE TAKEN DOWN
SOONER...BUT WITH THE POSSIBILITY FOR CONVECTIVE SNOW BURSTS IN THE
AFTERNOON...AM HESITANT TO MODIFY ENDING TIMES JUST YET. CENTRAL
MOUNTAIN HEADLINES ABOVE 11KFT CONTINUE THROUGH MONDAY
AFTERNOON...AND THIS SEEMS THE BEST WAY TO HANDLE THE EVENT GIVEN
THE PERSISTENT SNOW EVEN THOUGH IT MAY DECREASE IN INTENSITY FOR A
TIME THIS AFTERNOON AND EVENING. MEANWHILE...CONVECTIVE SNOW SHOWERS
ACROSS THE SE MTS/ADJACENT I-25 CORRIDOR SHOULD DIMINISH DURING THE
EVENING HOURS WITH DRY CONDITIONS RETURNING TO THE SE MTS BY
MIDNIGHT. -KT
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 454 AM MST SUN NOV 23 2014
PRIMARY LONGER TERM METEOROLOGICAL ISSUES ARE TEMPERATURES...GUSTY
WINDS AT TIMES AND POPS(PRIMARILY OVER THE CENTRAL MOUNTAINS AT
TIMES).
OTHER THAN GUSTY WINDS AND SNOW OVER PORTIONS OF THE CONTINENTAL
DIVIDE AT TIMES(ESPECIALLY OVER THE CENTRAL MOUNTAINS)...EXPECT A
BASICALLY DRY AND MILD METEOROLOGICAL PATTERN TO GRACE THE
CWFA...ESPECIALLY FROM TUESDAY INTO THANKSGIVING WEEKEND.
INITIALLY...ACCUMULATING SNOW AS WELL AS GUSTY WINDS ARE PROJECTED
TO CONTINUE OVER THE CENTRAL MOUNTAINS INTO AT LEAST MONDAY AS
ADEQUATE ATMOSPHERIC MOISTURE IN COMBINATION WITH ANOTHER UPPER
DISTURBANCE IMPACTS THE REGION...THEREFORE WILL CONTINUE THE
WINTER STORM WARNING FOR PUBLIC ZONES 58 AND 60 THROUGH MONDAY
AFTERNOON.
ELSEWHERE OVER THE FORECAST DISTRICT...LOW-GRADE TO NIL POPS AS
WELL AS LOCALIZED GUSTY WINDS ARE ANTICIPATED FROM MONDAY INTO
TUESDAY. IN ADDITION...GENERALLY BELOW SEASONAL TEMPERATURES ARE
ALSO PROJECTED OVER SOUTHERN COLORADO FROM MONDAY INTO AT LEAST
TUESDAY MORNING.
THEN...AS BASICALLY DRY NORTHWESTERLY TO ZONAL UPPER FLOW DEVELOPS
OVER THE FORECAST DISTRICT FROM WEDNESDAY INTO THANKSGIVING
WEEKEND...PROJECT THAT DRY CONDITIONS WILL BE COMMON-PLACE IN
COMBINATION WITH MILD TEMPERATURES.
REGARDING TEMPERATURES...RECENT GFS40 AND DGEX SOLUTIONS INDICATE
WARMER TEMPERATURES THAN THE LATEST ECMWF SOLUTION OVER EASTERN
PORTIONS OF THE FORECAST DISTRICT...ESPECIALLY FROM FRIDAY INTO
SATURDAY AS THE ECMWF SOLUTION ALLOWS COOLER EASTERLY FLOW TO
DEVELOP OVER THESE LOCATIONS DURING THIS TIME-FRAME.
HOWEVER...THE DGEX...ECMWF AND GFS40 SOLUTIONS ALL SUGGEST THAT
THANKSGIVING DAY SHOULD EXPERIENCE THE WARMEST TEMPERATURES
DURING THE LONGER TERM IN COMBINATION WITH DRY CONDITIONS.
FINALLY...THE STRONGEST WINDS DURING THE LONGER TERM ARE
ANTICIPATED FROM TUESDAY INTO WEDNESDAY MORNING AND THEN AGAIN
DURING THANKSGIVING WEEKEND AT TIMES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 454 AM MST SUN NOV 23 2014
BAND OF -SHRASN WILL CONTINUE TO DROP SOUTHWARD ACROSS
PORTIONS OF THE SOUTHEAST PLAINS THIS MORNING BEHIND A COLD FRONT
PACKING NORTH WINDS 20-40 KT. THIS FRONT WILL DROP THROUGH ALL OF
SE CO BY 12-13Z. BRUNT OF SNOW SHOWER ACTIVITY WILL BE FOCUSED
ALONG THE NORTHERN SLOPES OF THE PALMER DIVIDE AND THE RATON
RIDGE...AND THE NORTHEAST FACING SLOPES OF PIKES PEAK/TELLER
COUNTY...THE WET MOUNTAINS AND SANGRE DE CRISTO MOUNTAINS AND SRN I-
25 CORRIDOR. IFR TO LIFR CIGS/VIS WILL BE POSSIBLE IN THESE AREAS
WITH SNOW SHOWERS...ESPECIALLY DURING THE MORNING HOURS. KCOS HAS
THE BEST CHANCE FOR SEEING SOME SNOW THIS MORNING...WITH
TEMPERATURES DROPPING QUICKLY THROUGH 15Z...AND THE POSSIBILITY FOR A
QUICK UP TO 1/2 INCH OF SNOW AT THE TERMINAL. KPUB MAY SEE A BRIEF -
SHRASN VCNTY OF THE AIRPORT AS WELL...THOUGH PROBABILITY LOOKS
LOWER. MVFR CIGS WILL BE POSSIBLE AT BOTH KCOS AND KPUB WITH
SHOWERS. THIS WILL BE A QUICK BLAST...WITH SHOWERS ENDING FOR THE
MOST PART BY 16Z. NORTH WINDS GUSTING TO 30-35 KTS WILL BE POSSIBLE
THIS MORNING FOR BOTH KCOS AND KPUB WITH GUSTS DROPPING BACK INTO
THE 25 KT RANGE IN THE AFTERNOON.
KALS WILL BE LESS LIKELY TO BE IMPACTED BY -SHSN TODAY SO WILL LEAVE
IT OUT OF THE TAFS FOR NOW. SHOULD SEE WINDS INCREASE AT KALS FROM
THE NORTHWEST BY LATE MORNING WITH GUSTS TO 25 KTS POSSIBLE THROUGH
THE DAY. CIGS WILL LIKELY REMAIN VFR.
WIDESPREAD MTN OBSCURATIONS CAN BE EXPECTED THIS MORNING ACROSS MOST
OF THE AREA. THE SOUTHEAST MTS AND THE EASTERN SAN JUANS WILL START
TO SEE SOME PARTIAL CLEARING IN THE AFTERNOON THOUGH CONVECTIVE SNOW
SHOWERS MAY CAUSE SOME LOCALIZED OBSCURATIONS AT TIMES THROUGH THE
AFTERNOON. CONDITIONS ARE EXPECTED TO REMAIN IFR TO LIFR ACROSS THE
CENTRAL MOUNTAINS WHERE OROGRAPHIC SNOW SHOWERS WILL CONTINUE INTO
TONIGHT. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 5 PM MST THIS AFTERNOON FOR COZ064-
066-068.
WINTER WEATHER ADVISORY UNTIL 11 PM MST THIS EVENING FOR COZ059-
061.
WINTER STORM WARNING UNTIL 5 PM MST MONDAY FOR COZ058-060.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
728 AM EST SUN NOV 23 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 523 AM EST SUN NOV 23 2014
MAIN FORECAST CONCERNS INCLUDE DENSE FOG THIS MORNING...TIMING THE
ONSET OF PCPN LATER TODAY AND THEN THE CHANGEOVER TO SNOW LATE
TONIGHT IN THE WEST.
WV IMAGERY AND RUC ANALYSIS SHOWS A VIGOROUS SRN STREAM SHORTWAVE
OFF THE TX GULF COAST WITH A STRONG SHORTWAVE AND ASSOC 150+ KNOT
250 MB JET MOVING OFF THE PAC NW INTO NRN NEVADA. ANOTHER SHORTWAVE
TROUGH WAS MOVING INTO WRN ND. AT THE SFC...SRLY FLOW PREVAILED FROM
THE GULF TOWARD THE UPPER MS VALLEY AND NRN GREAT LAKES REGION BTWN
HIGH PRES OVER THE MID ATLANTIC AND A 993 MB LOW OVER ND. WAA AND
LOW CLOUD COVER HAVE MAINTAINED TEMPS IN THE MID AND UPPER 30S
ACROSS UPPER MI EARLY THIS MORNING. THE WARM AIR MOVING OVER THE
MOSTLY SNOWPACKED GROUND HAS ALSO RESULTED IN DENSE FOG ACROSS MUCH
OF THE ERN TWO THIRDS OF UPPER MI THIS MORNING.
TODAY...EXPECT PCPN CHANCES TO GRADUALLY INCREASE THROUGH THE DAY AS
STRONG MOISTURE ADVECTION/TRANSPORT CONTINUES AND 850-700 MB FGEN
INCREASES. EXPECT THE BETTER CHANCE FOR RAIN OVER THE SOUTH CENTRAL
AND EAST IN PROXIMITY TO THE STRONGER DYNAMICS AND BEST MOISTURE. AS
THE MID-LVL DRY LAYER MOISTENS UP ANY DRIZZLE SHOULD CHANGE OVER TO
RAIN BY MID TO LATE AFTERNOON. EXPECT TEMPS WILL CLIMB ABOVE NORMAL
INTO THE LOW TO MID 40S. WARM AIR MOVING OVER THE COLD SNOW PACK HAS
RESULTED IN DENSE FOG THIS MORNING SO HAVE POSTED A DENSE FOG
ADVISORY THROUGH 16Z FOR ALL BUT THE FAR FOUR WESTERN COUNTIES OF
THE CWA.
TONIGHT...CONTINUED INCREASE IN DEEP LAYER Q-VECT
CONVERGENCE...DEVELOPMENT OF COUPLED UPPER JET STRUCTURE AND
ENHANCED 850-700 MB FGEN WILL LEAD TO WIDESPREAD RAINFALL ACROSS
MUCH OF THE CWA BY EVENING. MODEL AVERAGED QPF RANGES FROM .25 WEST
TO .75 SOUTHEAST. MODEL SNDGS AND CRITICAL 1000-850 MB THICKNESSES
SUGGEST RAIN WILL BEGIN TO SWITCH OVER TO SNOW FAR WEST AROUND 09Z
BUT WITH SNOW/WATER RATIOS RISING TO ONLY AROUND 6-7/1 BY 12Z MON
EXPECT SNOW ACCUMULATION TO BE LESS THAN AN INCH FOR THE FAR WEST BY
12Z MONDAY. THERE IS POTENTIAL FOR FOG TO BE AN ISSUE WITH RAIN OVER
THE SNOWPACK SO THIS WILL BE SOMETHING TO WATCH LATER TODAY. TEMPS WILL
RANGE FM THE LOWER 30S WEST TO UPPER 30S EAST.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 558 AM EST SUN NOV 23 2014
COMPLEX DEEPENING LOW PRESSURE SYSTEM AND ASSOCIATED SNOW/BLSN
MONDAY AND MONDAY NIGHT IS MAIN ISSUE.
WV LOOP AND 00Z RAOBS SHOW SPLIT FLOW OVER THE CONUS. STRONG
SHORTWAVE NOTED IN NORTHERN STREAM IS CROSSING SASKATCHEWAN WITH
VIGOROUS PAIR OF SHORTWAVES IN THE SOUTHERN STREAM OVER THE SOUTHERN
PLAINS AND INTO EAST TX. AT DAYBREAK ON MONDAY...SHORTWAVE CURRENTLY
OVER KS WILL BE LIFTING TOWARD UPPER GREAT LAKES. ASSOCIATED SFC LOW
WILL BE IN PROCESS OF DEEPENING TO AROUND 980MB VCTY OF NORTHERN
LOWER MICHIGAN OR EASTERN UPR MICHIGAN. WIDESPREAD PRECIPITATION
SHOULD BE ONGOING DUE TO LIFT FM H7-H5 Q-VECTOR CONVERGENCE FM LEAD
SHORTWAVE...RIGHT ENTRANCE FORCING FM JET STREAK OVER NORTHERN
ONTARIO...AND H85-H7 MOISTURE ADVECTION WRAPPING AHEAD OF SFC-H85
LOW. SOUNDINGS SHOW COOLING BLO 900MB LEADING TO INITIAL CHANGEOVER
FROM RAIN TO SNOW OVER WESTERN THIRD OF CWA. EXPECTED RAIN/SNOW LINE
FOLLOWS 925MB TEMP OF 0C PRETTY WELL.
SNOW AMOUNTS ON MONDAY DEPEND ON EXTENT OF MOISTURE INGESTED INTO
THE SFC LOW...AND MORE SPECIFICALLY HOW MUCH OF THIS DEEP MOISTURE
IS ADVECTED FARTHER TO THE WEST OF THE SFC LOW BACK INTO THE COLD
AIR. AT THIS TIME...ONLY MODEL THAT IS REALLY EMPHATIC WITH STRONGER
AND SLOWER SFC LOW AND THUS MORE DEEP MOISTURE TO WORK WITH IS THE
00Z/06Z NAM. OTHER MODELS AND ENSEMBLES...INCLUDING THE 00Z GFS AND
ECMWF AND 21Z SREF...AND TO A LESSER DEGREE THE 00Z GEM...ARE MORE
PROGRESSIVE WITH THE LOW AND ULTIMATELY HAVE LESS DEEPER MOISTURE
AND SYNOPTIC QPF LINGERING INTO MONDAY AFTN. USING MORE MIDDLE OF
ROAD APPROACH AS DO NOT HAVE ENOUGH CONFIDENCE TO TREND TOWARD
WETTER NAM IDEA. LESSER QPF ALONG WITH SNOW-LIQUID RATIOS THAT
BARELY RISE ABOVE 10:1 MOST OF MONDAY...RESULTED IN SOLID ADVISORY
LEVEL SNOWS OF 2-4 INCHES OR MAYBE 3-5 INCHES...HEAVIEST OVER FAR
WESTERN CWA WHERE PTYPE IS SNOW FOR LONGEST DURATION. LESS THAN 1
INCH OF SNOW DURING THE DAYTIME FOR EAST WITH A LATER CHANGEOVER.
GOING WITH PREFERRED GFS/ECMWF IDEA FOR MONDAY NIGHT...SHORTWAVE
MOVING NORTHEAST OVER THE WESTERN GREAT LAKES IS CAUGHT UP SOME BY
ANOTHER SHORTWAVE LEFT OVER THE CURRENT TROUGH OVER SASKATCHEWAN.
SWATH OF MODERATE SNOW SHOULD RESULT...MAINLY OVER NORTH AND EAST
CWA. ENOUGH COLD AIR WORKING IN BY THAT TIME TO LEAD TO LAKE
ENHANCEMENT OFF LK SUPERIOR. SIGNAL STILL THERE THAT SECONDARY AREA
OF SYNOPTIC FORCING/LIFT LINKS UP WITH MOST IDEAL LAKE ENHANCEMENT
VCNTY OF NNW WIND SNOW BELTS OF ALGER/NORTHERN SCHOOLCRAFT COUNTIES.
LATEST 12 HR SNOW AMOUNTS ARE PUSHING WARNING CRITERIA OF 6 INCHES
FOR THESE AREAS. MODERATE SNOW ACCUMULATIONS WILL CONTINUE ALONG
MUCH OF LK SUPERIOR...BUT SNOW AMOUNTS SHOULD BE ON THE DECLINE
ALONG THE WI BORDER AS BETTER FORCING MISSES THAT AREA TO THE EAST.
FROM AT STRICTLY SNOW AMOUNT CRITERIA...EVENT LOOKS TO BE SOLID ADVY
MONDAY INTO MONDAY NIGHT. SNOW ON TUESDAY SHOULD BE ON THE WANE AS
EVEN THOUGH IT IS BECOMING COLDER FOR LAKE EFFECT...SUPPLEMENTAL
LARGER SCALE FORCING IS ON THE WANE. SOUNDINGS INDICATE LESSENING
CYCLONIC FLOW WILL REALLY PUT THE KABOSH ON LINGERING LAKE EFFECT ON
TUESDAY. ONE ASPECT OF THE SYSTEM THAT CANNOT BE DISCOUNTED THOUGH
IS THE WIND. SFC LOW DEEPENS AS IT LIFTS EAST OF LK SUPERIOR AND ON
TO THE NORTHEAST ON MONDAY NIGHT TRACKING TOWARD JAMES BAY. AT THE
PEAK...PRESSURE GRADIENT WEST TO EAST FROM DLH TO SSM IS 20 MB LATE
MONDAY AFTN INTO MONDAY EVENING. SOUNDINGS INDICATE 35+ KT WINDS
ABOVE H9 WITH 40+ KTS ABOVE H8. GIVEN THE DEGREE OF MIXING WITH THE
COLD AIR ADVECTION EXPECTED...SEEMS REASONABLE THAT MOST AREAS WILL
SEE GUSTS 30-40 MPH. BLOWING SNOW/POOR VSBY MAY BECOME PRETTY BIG
FACTOR OVER MUCH OF THE AREA WITH THE STRONG WINDS.
SINCE THIS EVENT SEEMS TO BE HEADING TOWARD MORE OF AN ADVY EVENT
INSTEAD OF A WARNING...DECIDED TO NOT ISSUE A WATCH AND INSTEAD
ISSUE ANOTHER SPECIAL WEATHER STATEMENT. DID EXPAND THE SPS TO
INCLUDE ALL OF THE CWA WITH THE POTENTIAL FOR MODERATE SNOW AND BLSN
OVER MUCH OF THE AREA.
REST OF THE WEEK COULD FEATURE HIGHER IMPACT WEATHER FOR THE TRAVEL
TIME AROUND THANKSGIVING AND THE HOLIDAY ITSELF. DETAILS FAR FROM
CERTAIN BUT AFTER A LULL FOR MOST AREAS ON TUESDAY NIGHT /MINS
POSSIBLY NEAR 0F OVER INTERIOR CNTRL CWA WITH ENOUGH CLEARING TUE
NIGHT/...ANOTHER PAIR OF SHORTWAVES ARE FORECAST TO SLIDE SOUTHEAST
OVER THE GREAT LAKES WEDNESDAY INTO WEDNESDAY NIGHT. GFS WEAKER THAN
THE ECMWF WITH THE SFC TROUGH AND THAT AFFECTS THE DEGREE OF
CYCLONIC FLOW AND LAKE ENHANCED SNOW THAT DEVELOPS AS THE SYSTEM
MOVES BY. ALSO COULD SEE MORE STRONG WINDS DUE TO TIGHTER PRESSURE
GRADIENT...ESPECIALLY NEAR LK SUPERIOR OVER THE WEST. HAVE LIKELY
POPS ALONG MOST OF THE NORTHERN PART OF CWA LATER WEDNESDAY INTO
WEDNESDAY NIGHT AND ALSO FOR THANKSGIVING NEAR LK SUPERIOR FOR
NNW-NW FLOW LAKE EFFECT. OVER-WATER INSTABILITY NON-ISSUE AS H85
TEMPS FALL BLO -15C WED NIGHT AND TREND TOWARD -20C ON THANKSGIVING.
TEMPS WILL STRUGGLE THROUGH THE TEENS ON THANKSGIVING MAKING IT MORE
LIKE LATE DECEMBER OR JANUARY. RECORD LOW MAX AT NWS MQT FOR 27
NOVEMBER IS 18 SET IN 1967. COULD BE CLOSE TO THAT MARK.
COLD AIRMASS WILL KEEP LAKE EFFECT GOING TO CLOSE THE WEEK...MAINLY
FOR WNW-WSW FLOW REGIMES...SO MOSTLY LOOKING AT KEWEENAW AND ALONG
LK SUPERIOR TO EAST OF MARQUETTE. IF THERE IS ANY MODERATION IN
TEMPS IT PROBABLY WILL NOT BE UNTIL LATE IN THE WEEKEND OR EVEN
EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 723 AM EST SUN NOV 23 2014
MOISTURE CONTINUING TO FLOW INTO THE AREA WILL RESULT IN LOWERING OF
CIGS TODAY AS THE MOIST LOW-LEVELS WILL BE ONLY BE AIDED BY
ADDITIONAL MOISTURE AND HELPED ALONG BY DEVELOPING UPSLOPE FLOW AT
KCMX AND KSAW. EXPECT VLIFR VSBYS IN FOG AT KSAW AT LEAST THROUGH
THIS MORNING. DZ WILL GIVE WAY TO RAIN LATER TODAY INTO TONIGHT AS
CONDITIONS STAY LIFR/VLIFR THROUGH THE REST OF THE FORECAST PERIOD AT
ALL SITES. RAIN WILL CHANGE OVER TO SNOW AT KIWD AFT 09Z TONIGHT. &&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 523 AM EST SUN NOV 23 2014
SOUTH WINDS WILL INCREASE ON SUNDAY...ESPECIALLY OVER EASTERN
SECTIONS...BUT SHOULD REMAIN 30 KTS OR LESS. WINDS WILL BE VARIABLE
SUNDAY NIGHT AS TROUGH CROSSES LAKE SUPERIOR. A DEEPENING LOW WILL
MOVE TO EAST OF LAKE SUPERIOR ON MONDAY. NORTHERLY WINDS WILL
INCREASE TO GALES 40-45 KTS BY MONDAY MORNING INTO MONDAY NIGHT.
EXPECT WINDS TO DIMINISH TO 25 KTS OR LESS TUESDAY INTO
WEDNESDAY...THEN INCREASE TO 30 KTS ON THURSDAY AS COLD AIR POURS
ACROSS LAKE SUPERIOR BETWEEN HIGH PRESSURE BUILDING OVER THE
NORTHERN PLAINS AND LOW PRESSURE CROSSING THE LOWER GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
DENSE FOG ADVISORY UNTIL 11 AM EST /10 AM CST/ THIS MORNING FOR
MIZ004>007-010>014-085.
LAKESHORE FLOOD ADVISORY FROM 11 AM MONDAY TO 6 AM EST TUESDAY
FOR MIZ001-003-005>007.
LAKE SUPERIOR...
GALE WARNING FROM 3 PM MONDAY TO 4 AM EST TUESDAY FOR LSZ251-267.
GALE WARNING FROM 10 AM MONDAY TO 4 AM EST TUESDAY FOR
LSZ246>250-265-266.
GALE WARNING FROM 6 AM MONDAY TO 2 AM EST TUESDAY FOR LSZ242>245-
263-264.
GALE WARNING FROM NOON EST /11 AM CST/ TO 9 PM EST /8 PM CST/
MONDAY FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...JLA
AVIATION...VOSS
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
601 AM EST SUN NOV 23 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 523 AM EST SUN NOV 23 2014
MAIN FORECAST CONCERNS INCLUDE DENSE FOG THIS MORNING...TIMING THE
ONSET OF PCPN LATER TODAY AND THEN THE CHANGEOVER TO SNOW LATE
TONIGHT IN THE WEST.
WV IMAGERY AND RUC ANALYSIS SHOWS A VIGOROUS SRN STREAM SHORTWAVE
OFF THE TX GULF COAST WITH A STRONG SHORTWAVE AND ASSOC 150+ KNOT
250 MB JET MOVING OFF THE PAC NW INTO NRN NEVADA. ANOTHER SHORTWAVE
TROUGH WAS MOVING INTO WRN ND. AT THE SFC...SRLY FLOW PREVAILED FROM
THE GULF TOWARD THE UPPER MS VALLEY AND NRN GREAT LAKES REGION BTWN
HIGH PRES OVER THE MID ATLANTIC AND A 993 MB LOW OVER ND. WAA AND
LOW CLOUD COVER HAVE MAINTAINED TEMPS IN THE MID AND UPPER 30S
ACROSS UPPER MI EARLY THIS MORNING. THE WARM AIR MOVING OVER THE
MOSTLY SNOWPACKED GROUND HAS ALSO RESULTED IN DENSE FOG ACROSS MUCH
OF THE ERN TWO THIRDS OF UPPER MI THIS MORNING.
TODAY...EXPECT PCPN CHANCES TO GRADUALLY INCREASE THROUGH THE DAY AS
STRONG MOISTURE ADVECTION/TRANSPORT CONTINUES AND 850-700 MB FGEN
INCREASES. EXPECT THE BETTER CHANCE FOR RAIN OVER THE SOUTH CENTRAL
AND EAST IN PROXIMITY TO THE STRONGER DYNAMICS AND BEST MOISTURE. AS
THE MID-LVL DRY LAYER MOISTENS UP ANY DRIZZLE SHOULD CHANGE OVER TO
RAIN BY MID TO LATE AFTERNOON. EXPECT TEMPS WILL CLIMB ABOVE NORMAL
INTO THE LOW TO MID 40S. WARM AIR MOVING OVER THE COLD SNOW PACK HAS
RESULTED IN DENSE FOG THIS MORNING SO HAVE POSTED A DENSE FOG
ADVISORY THROUGH 16Z FOR ALL BUT THE FAR FOUR WESTERN COUNTIES OF
THE CWA.
TONIGHT...CONTINUED INCREASE IN DEEP LAYER Q-VECT
CONVERGENCE...DEVELOPMENT OF COUPLED UPPER JET STRUCTURE AND
ENHANCED 850-700 MB FGEN WILL LEAD TO WIDESPREAD RAINFALL ACROSS
MUCH OF THE CWA BY EVENING. MODEL AVERAGED QPF RANGES FROM .25 WEST
TO .75 SOUTHEAST. MODEL SNDGS AND CRITICAL 1000-850 MB THICKNESSES
SUGGEST RAIN WILL BEGIN TO SWITCH OVER TO SNOW FAR WEST AROUND 09Z
BUT WITH SNOW/WATER RATIOS RISING TO ONLY AROUND 6-7/1 BY 12Z MON
EXPECT SNOW ACCUMULATION TO BE LESS THAN AN INCH FOR THE FAR WEST BY
12Z MONDAY. THERE IS POTENTIAL FOR FOG TO BE AN ISSUE WITH RAIN OVER
THE SNOWPACK SO THIS WILL BE SOMETHING TO WATCH LATER TODAY. TEMPS WILL
RANGE FM THE LOWER 30S WEST TO UPPER 30S EAST.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 558 AM EST SUN NOV 23 2014
COMPLEX DEEPENING LOW PRESSURE SYSTEM AND ASSOCIATED SNOW/BLSN
MONDAY AND MONDAY NIGHT IS MAIN ISSUE.
WV LOOP AND 00Z RAOBS SHOW SPLIT FLOW OVER THE CONUS. STRONG
SHORTWAVE NOTED IN NORTHERN STREAM IS CROSSING SASKATCHEWAN WITH
VIGOROUS PAIR OF SHORTWAVES IN THE SOUTHERN STREAM OVER THE SOUTHERN
PLAINS AND INTO EAST TX. AT DAYBREAK ON MONDAY...SHORTWAVE CURRENTLY
OVER KS WILL BE LIFTING TOWARD UPPER GREAT LAKES. ASSOCIATED SFC LOW
WILL BE IN PROCESS OF DEEPENING TO AROUND 980MB VCTY OF NORTHERN
LOWER MICHIGAN OR EASTERN UPR MICHIGAN. WIDESPREAD PRECIPITATION
SHOULD BE ONGOING DUE TO LIFT FM H7-H5 Q-VECTOR CONVERGENCE FM LEAD
SHORTWAVE...RIGHT ENTRANCE FORCING FM JET STREAK OVER NORTHERN
ONTARIO...AND H85-H7 MOISTURE ADVECTION WRAPPING AHEAD OF SFC-H85
LOW. SOUNDINGS SHOW COOLING BLO 900MB LEADING TO INITIAL CHANGEOVER
FROM RAIN TO SNOW OVER WESTERN THIRD OF CWA. EXPECTED RAIN/SNOW LINE
FOLLOWS 925MB TEMP OF 0C PRETTY WELL.
SNOW AMOUNTS ON MONDAY DEPEND ON EXTENT OF MOISTURE INGESTED INTO
THE SFC LOW...AND MORE SPECIFICALLY HOW MUCH OF THIS DEEP MOISTURE
IS ADVECTED FARTHER TO THE WEST OF THE SFC LOW BACK INTO THE COLD
AIR. AT THIS TIME...ONLY MODEL THAT IS REALLY EMPHATIC WITH STRONGER
AND SLOWER SFC LOW AND THUS MORE DEEP MOISTURE TO WORK WITH IS THE
00Z/06Z NAM. OTHER MODELS AND ENSEMBLES...INCLUDING THE 00Z GFS AND
ECMWF AND 21Z SREF...AND TO A LESSER DEGREE THE 00Z GEM...ARE MORE
PROGRESSIVE WITH THE LOW AND ULTIMATELY HAVE LESS DEEPER MOISTURE
AND SYNOPTIC QPF LINGERING INTO MONDAY AFTN. USING MORE MIDDLE OF
ROAD APPROACH AS DO NOT HAVE ENOUGH CONFIDENCE TO TREND TOWARD
WETTER NAM IDEA. LESSER QPF ALONG WITH SNOW-LIQUID RATIOS THAT
BARELY RISE ABOVE 10:1 MOST OF MONDAY...RESULTED IN SOLID ADVISORY
LEVEL SNOWS OF 2-4 INCHES OR MAYBE 3-5 INCHES...HEAVIEST OVER FAR
WESTERN CWA WHERE PTYPE IS SNOW FOR LONGEST DURATION. LESS THAN 1
INCH OF SNOW DURING THE DAYTIME FOR EAST WITH A LATER CHANGEOVER.
GOING WITH PREFERRED GFS/ECMWF IDEA FOR MONDAY NIGHT...SHORTWAVE
MOVING NORTHEAST OVER THE WESTERN GREAT LAKES IS CAUGHT UP SOME BY
ANOTHER SHORTWAVE LEFT OVER THE CURRENT TROUGH OVER SASKATCHEWAN.
SWATH OF MODERATE SNOW SHOULD RESULT...MAINLY OVER NORTH AND EAST
CWA. ENOUGH COLD AIR WORKING IN BY THAT TIME TO LEAD TO LAKE
ENHANCEMENT OFF LK SUPERIOR. SIGNAL STILL THERE THAT SECONDARY AREA
OF SYNOPTIC FORCING/LIFT LINKS UP WITH MOST IDEAL LAKE ENHANCEMENT
VCNTY OF NNW WIND SNOW BELTS OF ALGER/NORTHERN SCHOOLCRAFT COUNTIES.
LATEST 12 HR SNOW AMOUNTS ARE PUSHING WARNING CRITERIA OF 6 INCHES
FOR THESE AREAS. MODERATE SNOW ACCUMULATIONS WILL CONTINUE ALONG
MUCH OF LK SUPERIOR...BUT SNOW AMOUNTS SHOULD BE ON THE DECLINE
ALONG THE WI BORDER AS BETTER FORCING MISSES THAT AREA TO THE EAST.
FROM AT STRICTLY SNOW AMOUNT CRITERIA...EVENT LOOKS TO BE SOLID ADVY
MONDAY INTO MONDAY NIGHT. SNOW ON TUESDAY SHOULD BE ON THE WANE AS
EVEN THOUGH IT IS BECOMING COLDER FOR LAKE EFFECT...SUPPLEMENTAL
LARGER SCALE FORCING IS ON THE WANE. SOUNDINGS INDICATE LESSENING
CYCLONIC FLOW WILL REALLY PUT THE KABOSH ON LINGERING LAKE EFFECT ON
TUESDAY. ONE ASPECT OF THE SYSTEM THAT CANNOT BE DISCOUNTED THOUGH
IS THE WIND. SFC LOW DEEPENS AS IT LIFTS EAST OF LK SUPERIOR AND ON
TO THE NORTHEAST ON MONDAY NIGHT TRACKING TOWARD JAMES BAY. AT THE
PEAK...PRESSURE GRADIENT WEST TO EAST FROM DLH TO SSM IS 20 MB LATE
MONDAY AFTN INTO MONDAY EVENING. SOUNDINGS INDICATE 35+ KT WINDS
ABOVE H9 WITH 40+ KTS ABOVE H8. GIVEN THE DEGREE OF MIXING WITH THE
COLD AIR ADVECTION EXPECTED...SEEMS REASONABLE THAT MOST AREAS WILL
SEE GUSTS 30-40 MPH. BLOWING SNOW/POOR VSBY MAY BECOME PRETTY BIG
FACTOR OVER MUCH OF THE AREA WITH THE STRONG WINDS.
SINCE THIS EVENT SEEMS TO BE HEADING TOWARD MORE OF AN ADVY EVENT
INSTEAD OF A WARNING...DECIDED TO NOT ISSUE A WATCH AND INSTEAD
ISSUE ANOTHER SPECIAL WEATHER STATEMENT. DID EXPAND THE SPS TO
INCLUDE ALL OF THE CWA WITH THE POTENTIAL FOR MODERATE SNOW AND BLSN
OVER MUCH OF THE AREA.
REST OF THE WEEK COULD FEATURE HIGHER IMPACT WEATHER FOR THE TRAVEL
TIME AROUND THANKSGIVING AND THE HOLIDAY ITSELF. DETAILS FAR FROM
CERTAIN BUT AFTER A LULL FOR MOST AREAS ON TUESDAY NIGHT /MINS
POSSIBLY NEAR 0F OVER INTERIOR CNTRL CWA WITH ENOUGH CLEARING TUE
NIGHT/...ANOTHER PAIR OF SHORTWAVES ARE FORECAST TO SLIDE SOUTHEAST
OVER THE GREAT LAKES WEDNESDAY INTO WEDNESDAY NIGHT. GFS WEAKER THAN
THE ECMWF WITH THE SFC TROUGH AND THAT AFFECTS THE DEGREE OF
CYCLONIC FLOW AND LAKE ENHANCED SNOW THAT DEVELOPS AS THE SYSTEM
MOVES BY. ALSO COULD SEE MORE STRONG WINDS DUE TO TIGHTER PRESSURE
GRADIENT...ESPECIALLY NEAR LK SUPERIOR OVER THE WEST. HAVE LIKELY
POPS ALONG MOST OF THE NORTHERN PART OF CWA LATER WEDNESDAY INTO
WEDNESDAY NIGHT AND ALSO FOR THANKSGIVING NEAR LK SUPERIOR FOR
NNW-NW FLOW LAKE EFFECT. OVER-WATER INSTABILITY NON-ISSUE AS H85
TEMPS FALL BLO -15C WED NIGHT AND TREND TOWARD -20C ON THANKSGIVING.
TEMPS WILL STRUGGLE THROUGH THE TEENS ON THANKSGIVING MAKING IT MORE
LIKE LATE DECEMBER OR JANUARY. RECORD LOW MAX AT NWS MQT FOR 27
NOVEMBER IS 18 SET IN 1967. COULD BE CLOSE TO THAT MARK.
COLD AIRMASS WILL KEEP LAKE EFFECT GOING TO CLOSE THE WEEK...MAINLY
FOR WNW-WSW FLOW REGIMES...SO MOSTLY LOOKING AT KEWEENAW AND ALONG
LK SUPERIOR TO EAST OF MARQUETTE. IF THERE IS ANY MODERATION IN
TEMPS IT PROBABLY WILL NOT BE UNTIL LATE IN THE WEEKEND OR EVEN
EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 112 AM EST SUN NOV 23 2014
MOISTURE CONTINUING TO FLOW INTO THE AREA SHOULD RESULT IN LOWERING
OF CIGS FALLING TO LIFR LATE TONIGHT AS THE MOIST LOW-LEVELS WILL BE
ONLY BE AIDED BY ADDITIONAL MOISTURE AND HELPED ALONG BY DEVELOPING
UPSLOPE FLOW AT KCMX AND KSAW. THESE SITES WILL PROBABLY SEE DRIZZLE
AND FOG AS WELL WITH VSBY LIKELY REACHING IFR LATE TONIGHT.
CONDITIONS WILL STAY LIFR/VLIFR THROUGH THE REST OF THE FORECAST
PERIOD AT ALL SITES.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 523 AM EST SUN NOV 23 2014
SOUTH WINDS WILL INCREASE ON SUNDAY...ESPECIALLY OVER EASTERN
SECTIONS...BUT SHOULD REMAIN 30 KTS OR LESS. WINDS WILL BE VARIABLE
SUNDAY NIGHT AS TROUGH CROSSES LAKE SUPERIOR. A DEEPENING LOW WILL
MOVE TO EAST OF LAKE SUPERIOR ON MONDAY. NORTHERLY WINDS WILL
INCREASE TO GALES 40-45 KTS BY MONDAY MORNING INTO MONDAY NIGHT.
EXPECT WINDS TO DIMINISH TO 25 KTS OR LESS TUESDAY INTO
WEDNESDAY...THEN INCREASE TO 30 KTS ON THURSDAY AS COLD AIR POURS
ACROSS LAKE SUPERIOR BETWEEN HIGH PRESSURE BUILDING OVER THE
NORTHERN PLAINS AND LOW PRESSURE CROSSING THE LOWER GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
DENSE FOG ADVISORY UNTIL 11 AM EST /10 AM CST/ THIS MORNING FOR
MIZ004>007-010>014-085.
LAKE SUPERIOR...
GALE WARNING FROM 3 PM MONDAY TO 4 AM EST TUESDAY FOR LSZ251-267.
GALE WARNING FROM 10 AM MONDAY TO 4 AM EST TUESDAY FOR
LSZ246>250-265-266.
GALE WARNING FROM 6 AM MONDAY TO 2 AM EST TUESDAY FOR LSZ242>245-
263-264.
GALE WARNING FROM NOON EST /11 AM CST/ TO 9 PM EST /8 PM CST/
MONDAY FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...JLA
AVIATION...07
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
525 AM EST SUN NOV 23 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 523 AM EST SUN NOV 23 2014
MAIN FORECAST CONCERNS INCLUDE DENSE FOG THIS MORNING...TIMING THE
ONSET OF PCPN LATER TODAY AND THEN THE CHANGEOVER TO SNOW LATE
TONIGHT IN THE WEST.
WV IMAGERY AND RUC ANALYSIS SHOWS A VIGOROUS SRN STREAM SHORTWAVE
OFF THE TX GULF COAST WITH A STRONG SHORTWAVE AND ASSOC 150+ KNOT
250 MB JET MOVING OFF THE PAC NW INTO NRN NEVADA. ANOTHER SHORTWAVE
TROUGH WAS MOVING INTO WRN ND. AT THE SFC...SRLY FLOW PREVAILED FROM
THE GULF TOWARD THE UPPER MS VALLEY AND NRN GREAT LAKES REGION BTWN
HIGH PRES OVER THE MID ATLANTIC AND A 993 MB LOW OVER ND. WAA AND
LOW CLOUD COVER HAVE MAINTAINED TEMPS IN THE MID AND UPPER 30S
ACROSS UPPER MI EARLY THIS MORNING. THE WARM AIR MOVING OVER THE
MOSTLY SNOWPACKED GROUND HAS ALSO RESULTED IN DENSE FOG ACROSS MUCH
OF THE ERN TWO THIRDS OF UPPER MI THIS MORNING.
TODAY...EXPECT PCPN CHANCES TO GRADUALLY INCREASE THROUGH THE DAY AS
STRONG MOISTURE ADVECTION/TRANSPORT CONTINUES AND 850-700 MB FGEN
INCREASES. EXPECT THE BETTER CHANCE FOR RAIN OVER THE SOUTH CENTRAL
AND EAST IN PROXIMITY TO THE STRONGER DYNAMICS AND BEST MOISTURE. AS
THE MID-LVL DRY LAYER MOISTENS UP ANY DRIZZLE SHOULD CHANGE OVER TO
RAIN BY MID TO LATE AFTERNOON. EXPECT TEMPS WILL CLIMB ABOVE NORMAL
INTO THE LOW TO MID 40S. WARM AIR MOVING OVER THE COLD SNOW PACK HAS
RESULTED IN DENSE FOG THIS MORNING SO HAVE POSTED A DENSE FOG
ADVISORY THROUGH 16Z FOR ALL BUT THE FAR FOUR WESTERN COUNTIES OF
THE CWA.
TONIGHT...CONTINUED INCREASE IN DEEP LAYER Q-VECT
CONVERGENCE...DEVELOPMENT OF COUPLED UPPER JET STRUCTURE AND
ENHANCED 850-700 MB FGEN WILL LEAD TO WIDESPREAD RAINFALL ACROSS
MUCH OF THE CWA BY EVENING. MODEL AVERAGED QPF RANGES FROM .25 WEST
TO .75 SOUTHEAST. MODEL SNDGS AND CRITICAL 1000-850 MB THICKNESSES
SUGGEST RAIN WILL BEGIN TO SWITCH OVER TO SNOW FAR WEST AROUND 09Z
BUT WITH SNOW/WATER RATIOS RISING TO ONLY AROUND 6-7/1 BY 12Z MON
EXPECT SNOW ACCUMULATION TO BE LESS THAN AN INCH FOR THE FAR WEST BY
12Z MONDAY. THERE IS POTENTIAL FOR FOG TO BE AN ISSUE WITH RAIN OVER
THE SNOWPACK SO THIS WILL BE SOMETHING TO WATCH LATER TODAY. TEMPS WILL
RANGE FM THE LOWER 30S WEST TO UPPER 30S EAST.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 426 PM EST SAT NOV 22 2014
QUITE AN ACTIVE START TO THE PERIOD AS THE PHASING OF NORTHERN AND
SOUTHERN ENERGY WILL BE UNDERWAY ACROSS THE UPPER GREAT LAKES.
MODERATE RAINFALL SUNDAY NIGHT WILL GIVE WAY TO A TRANSITION TO SNOW
ON MONDAY AS THE SYSTEM MOVES NE OF THE REGION. THE INGREDIENTS ARE
STILL THERE FOR MODERATE TO POSSIBLY HEAVY SNOW ACROSS AT LEAST THE
WESTERN CWA MONDAY AFTERNOON AND NIGHT. AFTER A REPRIEVE LATE
TUESDAY...A CLIPPER SYSTEM LOOKS TO BRING LIGHT TO POSSIBLY MODERATE
SNOWFALL WEDNESDAY AFTERNOON INTO THANKSGIVING.
SUNDAY NIGHT THROUGH MONDAY NIGHT...FIRST A LOOK AT THE OVERALL
SYNOPTIC PATTERN. TWO POTENT MID-LEVEL SHORTWAVES...ONE TRACKING
EASTWARD OVER THE NORTHERN PLAINS AND THE OTHER MOVING NORTHEASTWARD
NEAR SOUTHERN IL AT 00Z MONDAY WILL BEGIN TO MERGE ACROSS THE UPPER
GREAT LAKES. THE NORTHERN STREAM IS A BIT SLOWER REACHING THE REGION
THAN THE SOUTHERN STREAM...RESULTING IN A BROADENING OF THE TROUGH
BY MONDAY MORNING. MEANWHILE...A DEVELOPING MODEST COUPLED JET
PATTERN WILL DEVELOP OVER THE UPPER GREAT LAKES. THE SOUTHERN WAVE
WILL BE OF MOST INTEREST INITIALLY AS IT INDUCES A RAPIDLY DEEPENING
LOW OVER ILLINOIS AT THE START OF THE PERIOD. WITH THE 12/18Z NAM
RUNS COMING INTO BETTER AGREEMENT WITH THE OTHER MODELS...CONFIDENCE
IS NOW HIGHER REGARDING THE OVERALL EVOLUTION OF THE SYSTEM. THE SFC
LOW IS PROGGED TO TRACK NEAR THE STRAITS OF MACKINAC AROUND 12Z
MONDAY. THE GEM/NAM/ECMWF HINT AT A SLIGHT DEVIATION TO THE LEFT/NW
MONDAY MORNING...WITH THE LOW CROSSING NEAR SAULT STE MARIE. THIS
LOOKS REASONABLE AS THE INFLUENCE OF THE NORTHERN TROUGH APPROACHES.
A LINGERING TROUGH WILL THEN REMAIN ACROSS UPPER MI ON MONDAY AS THE
MID-LEVEL TROUGH AXIS REACHES THE REGION AND THE SFC LOW MOVES TO
JUST SE OF JAMES BAY.
NOW A LOOK AT THE OVERALL PRECIP TYPE AND INTENSITY. MID/UPPER-LEVEL
DYNAMICS AND LOW-LEVEL THERMODYNAMICS SUPPORT MODERATE RAIN ACROSS
MAINLY CENTRAL AND EASTERN UPPER MI SUNDAY NIGHT. THE RIGHT ENTRANCE
OF A DEVELOPING...ALBEIT ANTICYCLONICALLY CURVED...UPPER JET WILL
MAXIMIZE UPPER DIVERGENCE OVER CENTRAL AND EASTERN UPPER MI WHILE
MID-LEVEL Q-VECTOR CONVERGENCE PEAKS OVER NORTHERN LOWER MI.
MEANWHILE...LOW-LEVEL MOISTURE TRANSPORT WILL BE RATHER IMPRESSIVE
ACROSS THE EASTERN CWA...THEN QUICKLY DIMINISH TOWARD THE WESTERN
CWA. A SUFFICIENTLY DEEP LOW-LEVEL WARM LAYER WILL KEEP PRECIP ALL
RAIN ACROSS THE CWA...THOUGH A TRANSITION TO SNOW WILL BE UNDERWAY
LATE SUNDAY NIGHT ACROSS THE WEST AS CAA BEGINS BEHIND THE LOW. ALL
THIS TOGETHER FAVORS MODERATE RAIN ACROSS THE EAST HALF SUNDAY
NIGHT...WITH AN INITIALLY SHARP CUTOFF TO THE WEST BEFORE THE
NORTHERN WAVE APPROACHES OVERNIGHT.
CAA TAKING HOLD ON MONDAY WILL QUICKLY TRANSITION THE RAIN TO SNOW
FROM WEST TO EAST THROUGHOUT THE DAY. THERE ARE SOME INDICATIONS
THAT A LOW-LEVEL WARM LAYER MAY TRY TO WRAP AROUND THE BACK SIDE OF
THE LOW LATE MORNING MORNING INTO THE AFTERNOON. SOME SLEET MAY MIX
IN WITH THE RAIN/SNOW...BUT THE TRANSITION FROM ALL RAIN SNOW SHOULD
NOT TAKE MORE THAN AN HOUR OR TWO. THINK THAT EVEN THE SHORELINE
LOCATIONS SHOULD TRANSITION QUICKLY GIVEN THEN COLDER THAN AVERAGE
LAKE TEMPS. TRANSITION TIMES LOOK TO BE AROUND 09Z FOR IWD...12Z FOR
A LINE FROM HOUGHTON TO IRON RIVER...AND 15Z FOR A LINE FROM
MARQUETTE TO IMT. BY 21Z...ALL BUT POSSIBLY LUCE COUNTY SHOULD
TRANSITION TO SNOW.
A FAIRLY IMPRESSIVE MID-LEVEL FGEN/DEFORMATION ZONE WILL SET UP OVER
THE WESTERN CWA BY MONDAY AFTERNOON. WITH SOME SNOWFLAKE FRACTURING
FROM THE HIGHER WINDS AND THE MAX LIFT INITIALLY OCCURRING AT TEMPS
JUST A BIT WARMER THAN THE DGZ...SNOW RATIOS MAY REMAIN LOW /10 TO
1/ THROUGH MONDAY MORNING. AS TEMPS CONTINUE TO FALL IN TO THE
AFTERNOON SNOW RATIOS WILL BE ON THE RISE ACROSS THE WEST. LOW-LEVEL
WINDS AVERAGING OUT THE NORTH COMBINED WITH LAKE-850MB DELTA TEMPS
SURPASSING 10C SUPPORT DECENT LAKE-ENHANCEMENT FOR THE NORTH WIND
SNOW BELTS THROUGHOUT MONDAY. THIS PATTERN WILL CONTINUE INTO MONDAY
EVENING AS THE CONSOLIDATED TROUGH SLOWS OVER THE AREA AND KEEPS A
SFC TROUGH EXTENDED ACROSS MUCH OF EASTERN UPPER MI. ON TOP OF THE
SNOW...THE CAA WITH A STRONG WNW TO ESE ISALLOBARIC COMPONENT FROM
THE RAPIDLY DEEPENING LOW WILL YIELD A QUICK INCREASE IN WIND FROM
THE N/NNW.
WHEN ALL IS SAID AND DONE...SNOWFALL MONDAY AND MONDAY NIGHT IS
EXPECTED TO BE 6 TO 10 INCHES BASICALLY NORTH OF M-28 AND WEST OF
MARQUETTE. ELSEWHERE ACROSS THE CWA...2-4 INCHES IS EXPECTED.
HOWEVER...HIGHER AMOUNTS OF UP TO 6 INCHES WILL BE POSSIBLE FOR THE
NNW WIND SNOW BELTS FROM SHOT POINT TO GRAND MARAIS. THREW AROUND
THE IDEA OF A WINTER STORM WATCH FOR THE NW HALF...BUT DECIDED
AGAINST IT GIVEN SOME DETAILS IN QPF AND PLACEMENT OF FORCING THAT
NEED TO BE IRONED OUT. HOWEVER...WINTER WX ADVISORY CRITERIA SHOULD
BE MET. HAVE OPTED TO ISSUE A SPECIAL WX STATEMENT AT THIS TIME TO
HIGHLIGHT THE POTENTIAL...BUT ALSO NOTE THE UNCERTAINTY IN AMOUNTS.
MAIN IMPACTS WILL BE RATHER SLUSHY ROADS IN THE AFTERNOON FOLLOWED
BY BLOWING AND DRIFTING OF THE SNOW OVERNIGHT AS SNOW RATIOS
INCREASE.
TUESDAY THROUGH WEDNESDAY NIGHT...WEAK MID-LEVEL RIDGING...LOW-LEVEL
WAA AND INVERSION HEIGHTS FALLING BELOW 3KFT WILL PUT A QUICK END TO
THE LES FROM WEST TO EAST THROUGHOUT THE DAY. A CLIPPER SHORTWAVE
WILL TRACK SE INTO THE UPPER MS VALLEY LATE TUESDAY. THE SHORTWAVE
LOOKS TO GET CAUGHT UP IN A LARGER-SCALE TROUGH OVER HUDSON
BAY...ULTIMATELY SLOWING ITS PROGRESSING AND SHIFTING IT TO A ENE
TRACK. WHERE THIS TAKES PLACE WILL BE CRUCIAL FOR DETERMINING SNOW
PROBABILITY/AMOUNTS FOR THE CWA. THE GFS IS THE FASTEST...BRINGING
WIDESPREAD ACCUMULATING SNOW TO THE AREA LATE TUESDAY NIGHT INTO
WEDNESDAY AFTERNOON. THE ECMWF TAKES AN INITIALLY MORE AGGRESSIVE
EVOLUTION...RESULTING THE THE TROUGH DIGGING FARTHER SOUTHEAST
BEFORE PIVOTING ACROSS SOUTHERN LAKE/LOWER MI. WITH THIS
SCENARIO...MOST OF THE SNOW HOLDS OFF UNTIL WEDNESDAY NIGHT. THE GEM
FOLLOWS A SOLUTION IN THE MIDDLE...BUT LEANS MORE IN LINE WITH THE
GFS. ATTM...CANNOT REALLY PIN DOWN AMOUNTS AND EXACT TIMING...THOUGH
THE PROSPECTS FOR SEVERAL INCHES OF ACCUMULATING SNOW SOMETIME LATE
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT ARE GROWING.
THANKSGIVING...DEPENDING ON WHAT MODEL SOLUTION PANS
OUT...WIDESPREAD SNOW MAY LINGER THROUGH THE MORNING OR END BEFORE
DAYBREAK. EITHER WAY...CAA BEHIND THE CLIPPER SHOULD YIELD LES FOR
THE N/NNW WIND BELTS DURING THE DAY. IT STILL LOOKS COLD...WITH
TEMPS MORE IN LINE WITH CHRISTMAS RATHER THAN THANKSGIVING.
HOWEVER...WITH THE SLOWER SOLUTION...THE ECMWF HAS A HARDER TIME
BRINGING THE COLDEST AIR INTO THE REGION.
FRIDAY AND SATURDAY...LONG RANGE MODELS HAVE BACKED OFF SOMEWHERE ON
A TRANSITION TO A MORE ZONAL AND MILD PATTERN BEGINNING FRIDAY AND
DELAY IT UNTIL LATE IN THE WEEKEND. THE OVERALL PATTERN LOOKS QUIET
BESIDE SOME LES FOR THE WNW WIND SNOW BELTS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 112 AM EST SUN NOV 23 2014
MOISTURE CONTINUING TO FLOW INTO THE AREA SHOULD RESULT IN LOWERING
OF CIGS FALLING TO LIFR LATE TONIGHT AS THE MOIST LOW-LEVELS WILL BE
ONLY BE AIDED BY ADDITIONAL MOISTURE AND HELPED ALONG BY DEVELOPING
UPSLOPE FLOW AT KCMX AND KSAW. THESE SITES WILL PROBABLY SEE DRIZZLE
AND FOG AS WELL WITH VSBY LIKELY REACHING IFR LATE TONIGHT.
CONDITIONS WILL STAY LIFR/VLIFR THROUGH THE REST OF THE FORECAST
PERIOD AT ALL SITES.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 523 AM EST SUN NOV 23 2014
SOUTH WINDS WILL INCREASE ON SUNDAY...ESPECIALLY OVER EASTERN
SECTIONS...BUT SHOULD REMAIN 30 KTS OR LESS. WINDS WILL BE VARIABLE
SUNDAY NIGHT AS TROUGH CROSSES LAKE SUPERIOR. A DEEPENING LOW WILL
MOVE TO EAST OF LAKE SUPERIOR ON MONDAY. NORTHERLY WINDS WILL
INCREASE TO GALES 40-45 KTS BY MONDAY MORNING INTO MONDAY NIGHT.
EXPECT WINDS TO DIMINISH TO 25 KTS OR LESS TUESDAY INTO
WEDNESDAY...THEN INCREASE TO 30 KTS ON THURSDAY AS COLD AIR POURS
ACROSS LAKE SUPERIOR BETWEEN HIGH PRESSURE BUILDING OVER THE
NORTHERN PLAINS AND LOW PRESSURE CROSSING THE LOWER GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
DENSE FOG ADVISORY UNTIL 11 AM EST /10 AM CST/ THIS MORNING FOR
MIZ004>007-010>014-085.
LAKE SUPERIOR...
GALE WARNING FROM 3 PM MONDAY TO 4 AM EST TUESDAY FOR LSZ251-267.
GALE WARNING FROM 10 AM MONDAY TO 4 AM EST TUESDAY FOR
LSZ246>250-265-266.
GALE WARNING FROM 6 AM MONDAY TO 2 AM EST TUESDAY FOR LSZ242>245-
263-264.
GALE WARNING FROM NOON EST /11 AM CST/ TO 9 PM EST /8 PM CST/
MONDAY FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...KLUBER
AVIATION...07
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
652 AM EST SUN NOV 23 2014
.SYNOPSIS...
A POTENT STORM SYSTEM WILL BRING WIND...RAIN AND POSSIBLY A FEW
STRONG THUNDERSTORMS TO THE AREA TODAY. RAIN WILL RETURN LATE
TUESDAY AND WEDNESDAY AFTER A BREAK MONDAY. THANKSGIVING DAY TO
THE END OF THE FORECAST PERIOD LOOKS DRY AND COLD.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 635 AM SUNDAY...S/W UPPER RIDGE ACROSS THE AREA ATTM...WILL
GIVE WAY TO THE APPROACH OF A POTENT SOUTHERN STREAM MID-LEVEL S/W
TROF FROM THE GULF COAST STATES THIS AFTN. MODELS INDICATE A
NEGATIVE TILT TO THIS UPPER S/W TROF AS IT LIFTS FROM THE FL
PANHANDLE NORTHEASTWARD ACROSS THE CAROLINAS THIS EVENING AND
OVERNIGHT.
THE SFC WARM FRONT SOMEWHAT WELL DISPLACED FROM THE SFC LOW THAT
IS MOVING NNE ACROSS THE CENTRAL U.S. TO THE GREAT LAKES BY MONDAY
DAYBREAK...WILL BE THE FOCUS OF THIS FCST. WHATS LEFT OF A WEAK
WEDGE ACROSS THE INLAND CWA THIS MORNING...WILL GIVE WAY TO THE
APPROACHING WARM FRONT THIS AFTN...WHICH LIFTS NORTHWARD ACROSS
THE FA LATER THIS EVENING THROUGH THE EARLY PRE-DAWN MON HOURS.
STRATIFORM RAINS IE. EXCELLENT ISENTROPIC LIFT...AHEAD OF THE
WARM FRONT AS MOISTURE FROM BOTH THE ATLANTIC AND GULF OF MEXICO
SOURCE AREAS ARE UTILIZED. DECENT WIND DIRECTION VEERING PROFILE
FROM THE SFC TO 700 MB THIS AFTERNOON AND EVENING ALONG WITH WIND
SPEEDS RANGING FROM 20-30 KT AT THE SFC...UP TO 60 KT AT 925 MB.
WITH WIND SHEAR LIKE THIS...ANY CONVECTION THAT TAPS INTO THESE
WINDS MAY PRODUCE DAMAGING WIND GUSTS OR EVEN THE POSSIBILITY OF A
TORNADO DUE TO FAVORABLE HELICITIES. WILL CONTINUE TO MENTION THE
SEVERE CONVECTIVE THREAT IN THE HWO. OVERALL...THE AVBL INSTABILITY
IE. CAPE...WILL LIKELY BE THE DETERMINING FACTOR FOR POTENTIAL
CONVECTIVE DEVELOPMENT ACROSS THE FA.
AN ABNORMAL DIURNAL TEMP CURVE WILL BE FORECAST THIS PACKAGE...
WITH TODAYS HIGHS LIKELY OCCURRING LATE THIS AFTERNOON...AND
TONIGHTS LOWS LIKELY THIS EVENING WITH STEADY OR EVEN RISING TEMPS
LATE THIS EVENING AND OVERNIGHT. ROUGHLY THE FORECAST AREA WILL BE
LOOKING AT 1 TO 2 INCH RAINFALL AMOUNTS TODAY THROUGH DAYBREAK
MON.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 330 AM SUNDAY...A BROAD SOUTHWEST FLOW ALOFT WILL CONTINUE
MONDAY AND TUESDAY WITH THE AFFECTS OF MASSIVE LOW PRESSURE OVER
THE GREAT LAKES LINGERING MONDAY. A WEAK PRESSURE TROUGH APPEARS
TO BE THE CATALYST FOR A FEW SHOWERS MONDAY WITH A DRY 24 HOURS OR
SO ENSUING.
THE SOUTHWEST FLOW WILL BE ENHANCED LATER TUESDAY AS A MID LEVEL
TROUGH MOVES INTO THE TENNESSEE VALLEY. A POTENT 300MB JET WITH THE
RIGHT ENTRANCE REGION BECOMING FAVORABLY PLACED LATER TUESDAY AND
EARLY WEDNESDAY WORKS IN TANDEM WITH A DEEP MOISTURE PLUME AND
WIDESPREAD RAIN DEVELOPS ONCE AGAIN. I HAVE INCREASED POPS FOR LATE
IN THE PERIOD TO ADDRESS. NO CHANGES TO THE TEMPERATURE FORECAST
WITH A WARM DAY IN STORE MONDAY COOLING SOME 10-15 DEGREES TUESDAY.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 330 AM SUNDAY...MEDIUM RANGE GUIDANCE CONTINUES TO PAINT A WET
SCENARIO FOR WEDNESDAY AS LOW PRESSURE...WELL OFFSHORE WITH
EXCELLENT UPPER LEVEL SUPPORT WORKS TOGETHER. IT HAS BEEN
INTERESTING SEEING HE 850MB ZERO ISOTHERM MOVING INTO THE AREA
WITH PRECIPITATION BUT SOUNDINGS SHOW THE LOWER LEVELS JUST A BIT
TOO WARM FOR ANY FROZEN PRECIPITATION. I RAISED POPS INCREMENTALLY
TO ADDRESS THE GOOD MODEL CONTINUITY AND INCREASED CONFIDENCE.
BEYOND THIS THE MID LEVEL PATTERN WILL BECOME ZONAL BY THE WEEKEND
WITH HIGH PRESSURE AT THE SURFACE FOR THE MOST PART. THERE WILL BE
A DRY COLD FRONT THAT MOVES ACROSS FRIDAY BUT LITTLE ELSE.
TEMPERATURES REMAIN BELOW CLIMATOLOGY THROUGHOUT.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
AS OF 12Z...A SLOW DETERIORATION OF CONDITIONS IS EXPECTED THROUGH THE
MORNING HOURS AS ISENTROPIC LIFT SLOWLY INCREASES. FIRST BATCH OF
PRECIP IS MOVING THROUGH THE REGION...POORLY DEPICTED BY THE HRRR BY
THE WAY. A SECOND AND MORE WIDESPREAD WAVE WITH MOVE THROUGH LATER
THIS MORNING. MODERATE RAIN WILL BE LIKELY WITH PRECIPITATION
INDUCED CEILINGS LOWERING TO IFR THIS AFTERNOON. ONLY MODERATE
CONFIDENCE WITH THE TIMING OF CEILINGS. MOST OF THE PRECIP TODAY
WILL BE STRATIFORM...HOWEVER COULD NOT RULE OUT A RUMBLE TOWARD
EVENING.
THIS EVENING...AN UPPER VORT MAX WILL SWEEP THROUGH THE REGION.
STRONG HELICITY BUT LITTLE TO NO CAPE WILL HARD TO RECONCILE.
BELIEVE THERE WILL BE A NARROW BAND OF CONVECTION THAT SHOULD PUSH
TO THE COAST BY 05-06Z. BEHIND THE VORT EXPECT THE PRECIP TO SHUT
OFF WITH MAINLY MVFR CEILINGS REMAINING.
EXTENDED OUTLOOK...UNSETTLED WEATHER IS EXPECTED MONDAY AND
POSSIBLY THROUGH TUESDAY...WITH OCCASIONAL SHOWERS AND MVFR/IFR
CONDITIONS. VFR LATE TUESDAY AFTERNOON WITH POSSIBLE MVFR
CONDITIONS WEDNESDAY. VFR THURSDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM SUNDAY...THE LOCAL WATERS WILL BE SUBJECT TO AN
EXTENDED PERIOD OF SCA CONDITIONS COMMENCING LATER THIS MORNING
AND LASTING INTO THE SHORT TERM PERIOD. INCREASING ONSHORE E TO SE
WINDS DURING TODAY...WILL VEER TO THE SOUTH AS THE WARM FRONT
LIFTS NORTHWARD ACROSS THE LOCAL WATERS FROM LATE THIS AFTN
THROUGH MIDNIGHT TONIGHT. THE SFC PG WILL FURTHER TIGHTEN ACROSS
THE LOCAL WATERS AS THE PARENT LOW ACROSS THE CENTRAL U.S. DEEPENS
AS IT LIFTS TO THE GREAT LAKES BY MON DAYBREAK. LOOKING AT SPEEDS
IN THE 15 TO 25 KT RANGE WITH GUSTS TO 30 KT BY THIS AFTERNOON...
FURTHER INCREASING TO 20 TO 30 KT WITH FEW GUSTS TO GALE FORCE. IF
WATER TEMPS WERE SLIGHTLY WARMER IN THE 60S INSTEAD OF THE 50S...A
GALE WARNING WOULD PROBABLY HAVE BEEN ISSUED...ALTHOUGH STILL NOT
OUT OF THE QUESTION GIVEN THE PASSAGE OF A DECENT UPPER S/W TROF
ACROSS THE SE UNITED STATES. SIGNIFICANT SEAS WILL QUICKLY BUILD
AS ONSHORE WINDS MAKE SURE OF THAT. SIG. SEAS WILL PEAK THIS
EVENING AND OVERNIGHT...IN THE 8 TO 12 FOOT RANGE...FOLLOWED BY A
VERY SLOW SUBSIDING TREND THERE-AFTER IN SUBSEQUENT PERIODS. WIND
DRIVEN WAVES WILL DOMINATE SIGNIFICANT SEAS...WITH AVERAGE PERIODS
IN THE 5.0 TO 6.5 SECONDS RANGE.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 330 AM SUNDAY...SMALL CRAFT CONDITIONS WILL CONTINUE MONDAY VIA
A STRONG SOUTHWEST FLOW OF 20-25 KNOTS AND SEAS OF 5-8 FEET. THE
WINDS WILL DIMINISH TUESDAY MORNING AND TURN TO THE WEST AS A WEAK
COLD FRONT PASSES. SEAS SHOULD FALL TO BELOW THE SMALL CRAFT
THRESHOLD SETTLING NICELY INTO A RANGE OF 2-4 FEET. ELEMENTS WILL
REMAIN TRANQUIL FOR THE REMAINDER OF THE PERIOD.
LONG TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 330 AM SUNDAY...FAIRLY BRISK NORTHWEST WINDS WEDNESDAY AS LOW
PRESSURE MOVES WELL OFFSHORE. SPEEDS WILL BE 20-25 KNOTS. WINDS
DIMINISH DRAMATICALLY THURSDAY AS A WEAK WESTERLY FLOW DEVELOPS.
SEAS WILL BE HIGHEST WEDNESDAY WITH 3-7 FEET...HIGHEST OFFSHORE.
VALUES DROP TO 2-4 FEET THURSDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 6 AM EST
TUESDAY FOR AMZ250-252-254-256.
&&
$$
SYNOPSIS...SHK
NEAR TERM...DCH
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...HDL
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
635 AM EST SUN NOV 23 2014
.SYNOPSIS...
A WARM FRONT WILL LIFT NORTH THROUGH THE REGION THIS AFTERNOON AND
TONIGHT. A COLD FRONT WILL APPROACH FROM THE WEST MONDAY AND PUSH
OFFSHORE BY EARLY TUESDAY. LOW PRESSURE WILL DEVELOP ALONG THE FRONT
LATE TUESDAY NIGHT AND MOVE NORTHEAST OFFSHORE OF THE COAST WEDNESDAY.
THE LOW WILL DEPART TO THE NORTHEAST WEDNESDAY NIGHT WITH HIGH PRESSURE
BUILDING OVER THE REGION LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 630 AM SUNDAY...SHIELD OF MOSTLY LIGHT RAIN HAS ARRIVED IN
OUR FAR SOUTHERN CWA. HAVE ADJUSTED POPS TO BEGIN RAINFALL
EARLIER...ALTHOUGH HEAVIER RAIN IS NOT LIKELY TO ARRIVE UNTIL THE
AFTERNOON HOURS. THE WARM FRONT WILL CONTINUE TO PROGRESS NORTH
THROUGH THE DAY. THE 3KM HRRR STILL INDICATES THAT THE STEADIER
AND HEAVIER RAIN WILL ARRIVE AROUND MIDDAY AND CONTINUE INTO
TONIGHT. TEMPERATURES CONTINUE TO SLOWLY RISE...ESPECIALLY NEAR
THE COAST. AS WARM FRONT SURGES NORTH...TEMPERATURES SHOULD
RECOVER TO HIGHS IN THE MID/UPPER 60S AREA-WIDE THIS AFTERNOON.
DEWPOINTS SHOULD ALSO RECOVER TO THE UPPER 50S BY AFTERNOON. POPS
INCREASE TO CATEGORICAL OVER ROUGHLY THE SOUTHWESTERN HALF OF THE
CWA BY EARLY AFTERNOON. RAIN CHANCES REMAIN LOWER OVER THE
NORTHEASTERN HALF AS DEWPOINT RECOVERY WILL TAKE A BIT LONGER.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
AS OF 330 AM SUNDAY...BY THIS EVENING...INSTABILITY INCREASES FROM
THE SOUTH AS STRONG WARM FRONT MOVES NORTH. VERY IMPRESSIVE LOW-
LEVEL SHEAR VALUES INDICATED BY FORECAST SOUNDINGS...WITH SRH
HELICITY VALUES UPWARDS OF 600-700 BY 00Z TONIGHT. THIS COINCIDES
WITH THE ARRIVAL OF THE INSTABILITY AND MOST OF THE CWA REMAINS IN
A SLIGHT RISK OF SEVERE TSTMS. THE PRIMARY THREAT WILL BE STRONG
DAMAGING WINDS AND THE RISK OF ISOLATED TORNADOES GIVEN THIS SHEAR
ENVIRONMENT. THE TORNADO/SEVERE THREAT SHOULD WANE AFTER 06Z AS
THE FLOW BECOMES MORE UNIDIRECTIONAL. IN ADDITION TO THE SEVERE
THREAT...QPF TOTALS OF 1 TO 2 INCHES WILL BE POSSIBLE AS DEEP
MOISTURE IS ADVECTED FROM THE ATLANTIC WITH VERY IMPRESSIVE LOW-
LEVEL MOISTURE TRANSPORT. GIVEN THE WARM SW WINDS...EXPECT
TEMPERATURES TO FALL VERY LITTLE TONIGHT...LIKELY REMAINING IN THE
LOWER 60S.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
AS OF 330 AM SUN...LARGE UPPER TROUGH OVER THE CENTRAL PART OF THE
COUNTRY WITH LOTS OF ENERGY ROTATING AROUND IT WILL MAKE FOR AN
ACTIVE PERIOD INTO THANKSGIVING WITH HIGH PRESSURE TAKING HOLD
THROUGH THE REMAINDER OF THE PERIOD. THIS ACTIVE WEATHER COULD
HAMPER HOLIDAY TRAVEL PLANS.
TROUGH WILL CONTINUE TO DIG INTO THE SOUTHERN TIER STATES THROUGH
MID WEEK THEN LIFT THROUGH THE SOUTHEAST AND MID ATLANTIC THROUGH
THE END OF THE WEEK. MOST OF THE PRECIPITATION CHANCES WILL END BY
MONDAY MORNING ASSOCIATED WITH A VIGOROUS SHRTWV MOVING THROUGH THE
AREA. KEPT SMALL CHANCE POPS IN ON MONDAY UNTIL THE FIRST COLD FRONT
MOVES THROUGH THE AREA TUESDAY NIGHT. WON`T GET MUCH OF A BREAK AS
STRONG UPPER LEVEL ENERGY WILL SWING THROUGH THE BASE OF THE UPPER
TROUGH HELPING TO FORM A WAVE ON THE SURFACE FRONT IN THE GULF
TUESDAY THAT WILL MOVE UP THE EAST COAST DURING THE NIGHT TUESDAY
NIGHT. CROSS SECTIONS SHOWING DEEP LAYER MOISTURE AND GOOD LIFT. AS
MENTIONED. THE 00Z GFS AND ECMWF ARE NOW CLOSER IN PHASE
WITH THEIR SOLUTIONS WITH DEEP THE TROUGH AND AREA OF LOW PRESSURE
DEEPENING ALONG THE COAST WEDNESDAY BUT STILL HAVE DIFFERENCES THAT
WILL AFFECT THE FCST...ESPECIALLY ON THE EXACT TRACK OF THE LOW AND
STRENGTH OF WINDS. MODELS DO BOTH PRODUCE A GOOD AMOUNT OF QPF WITH
HEAVY RAINS AND WINDY CONDITIONS DEVELOPING LATE TUESDAY NIGHT AND
CONTINUING THROUGH THE DAY WEDNESDAY WITH PRECIPITATION ENDING
WEDNESDAY NIGHT AS THE LOW PULLS AWAY FROM THE COAST. THE AREA WILL
LIKELY SEE 1 TO 2 INCHES OR RAIN FROM LATE TUESDAY NIGHT THROUGH THE
EVENING WEDNESDAY. INCREASED POPS TO LIKELY INLAND TO CATEGORICAL
ALONG THE COAST WEDNESDAY.
THE GFS SHOWS A CHANCE THERE WILL BE A BIT OF MOISTURE LEFT ACROSS
THE AREA AS A SURGE OF COLD AIR GETS USHERED IN BEHIND THE DEPARTING
SYSTEM WEDNESDAY NIGHT. THAT COULD RESULT IN A BRIEF RAIN SNOW MIX
OR PERHAPS FLURRIES. THE ECMWF SEEMS TO MORE LIKELY HAVE MOST OF THE
MOISTURE DEPART BEFORE COLDER AIR. NOT MUCH CONFIDENCE ON WHICH
SOLUTION WILL BE RIGHT AT THIS POINT BUT OPTED FOR MORE LIKELY
KEEPING PRECIPITATION ALL RAIN HERE. EVEN IF WE DID SEE A FEW FLAKES
WEDNESDAY NIGHT DO NOT EXPECT IT WOULD NOT AMOUNT TO ANYTHING.
THURSDAY INTO SATURDAY DRIER AND COOL HIGH PRESSURE BUILDS OVER THE
AREA WITH MOSTLY SUNNY SKIES BUT BELOW NORMAL TEMPERATURES.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
SHORT TERM /TODAY AND TONIGHT/...
AS OF 630 AM SUNDAY...WIDESPREAD LIGHT RAIN NOW SPREADING INTO THE
REGION. THE RAIN IS FALLING FROM GENERALLY A MID CLOUD DECK BUT
CEILINGS SHOULD LOWER THROUGH THE MORNING WITH WIDESPREAD MVFR
CEILINGS THROUGH THE BALANCE OF THE DAY. AS THE ATMOSPHERE BECOMES
MORE UNSTABLE LATER THIS EVENING...EXPECT STRONG GUSTY S/SW WINDS
WITH LOCALLY STRONG TO SEVERE TSTMS POSSIBLE. EXPECT CEILINGS AND
VSBYS TO DROP TO MVFR BY TONIGHT WITH WIDESPREAD PRECIPITATION.
LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 330 AM SUN...MVFR/IFR CONDITIONS SHOULD IMPROVE TO MVFR TO VFR
ON MONDAY AFTER THE WARM FRONT AND VIGOROUS SHRTWV PASSES THROUGH
THE AREA. THERE WILL STILL BE A SMALL CHANCE OF RAIN WITH SUB VFR
CONDITIONS POSSIBLE IN THE PRECIPITATION MONDAY AND TUESDAY. A
STRONG LOW PRESSURE WILL MOVE UP THE COAST TUESDAY NIGHT WITH IFR
CONDITIONS LIKELY...IN ADDITION TO RAIN AND STRONG WINDS THROUGH THE
DAY WEDNESDAY. BY THU HIGH PRESSURE BUILDS IN AND VFR CONDITIONS
RETURN.
&&
.MARINE...
SHORT TERM /TODAY AND TONIGHT/...
AS OF 635 AM SUNDAY...LIGHT SE/S WINDS THIS MORNING WITH SEAS 1 TO
3 FEET. THIS WILL GIVE WAY TO INCREASING WINDS DURING THE
AFTERNOON AS STRONG WARM FRONT SURGES NORTH. A GALE WARNING WAS
POSTED EARLIER FROM THIS EVENING THROUGH LATE MONDAY AFTERNOON. BY
TONIGHT...S/SW WINDS INCREASE TO 25 TO 35 KNOTS WITH A FEW GUSTS
TO 40 KNOTS LIKELY WITH SEAS BUILDING TO AS HIGH AS 15 FEET PER
LOCAL NWPS/SWAN MODEL. THESE GUSTY WINDS AND ROUGH SEAS WILL
ACCOMPANIED BY AREAS OF HEAVY RAIN AND EMBEDDED THUNDERSTORMS...SOME
STRONG. NO CHANGES TO THE MARINE FORECAST WITH THIS UPDATE.
LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 330 AM SUN...WILL HAVE A CONTINUED PERIOD OF STRONG GUSTY
SOUTHERLY WINDS CONTINUING INTO MONDAY SLOWLY DIMINISHING FROM WEST
TO EAST AS THE COLD FRONT APPROACHES THE AREA. GALE CONDITIONS WILL
END BY LATE MONDAY ACROSS THE CENTRAL WATERS BUT SEAS WILL REMAIN
TREACHEROUS THROUGH MONDAY NIGHT. A WEAK COLD FRONT MOVES THROUGH
MONDAY NIGHT WITH LIGHT NORTHERLY WINDS FOR THE DAY TUESDAY.
STRONG LOW PRESSURE WILL DEVELOP ALONG THE FRONT OFF THE COAST
TUESDAY NIGHT AND MOVE UP THE COAST WEDNESDAY. THE GFS AND ECMWF
DIFFER A BIT ON THE LOCATION AND TIMING OF THE FRONT WITH THE 00Z
ECMWF KEEPING IT RIGHT ALONG THE COAST WHICH RESULTS IN LIGHTER
WINDS ON WEDNESDAY. FAVORED PREVIOUS FCST AND GFS FOR KEEPING THE
LOW JUST OFF THE COAST WHICH MAY ALLOW GALE CONDITIONS TO DEVELOP
WEDNESDAY WITH THIS FEATURE. CURRENT FCST HAS GUSTS TO GALE FORCE ON
WED IN STRONG NORTHERLY FLOW. SEAS 10 TO 12 FEET ARE POSSIBLE
WEDNESDAY INTO WEDNESDAY NIGHT AS A RESULT. CONDITIONS ONLY SLOWLY
IMPROVE BY THANKSGIVING MORNING...WITH SEAS FALLING BELOW 6 FEET IN
THE CENTRAL WATERS LATE IN THE DAY ON THANKSGIVING. WINDS WILL
EVENTUALLY BECOME LIGHT BY THE WEEKEND AS HIGH PRESSURE BUILDS OVER
THE AREA.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...GALE WARNING FROM 10 PM THIS EVENING TO 4 PM EST MONDAY FOR
AMZ130-131-135>137-150-152-154-156-158.
&&
$$
SYNOPSIS...CTC
NEAR TERM...CTC
SHORT TERM...CTC
LONG TERM...RSB
AVIATION...RSB/CTC
MARINE...RSB/CTC
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
605 AM EST SUN NOV 23 2014
.SYNOPSIS...
A POTENT STORM SYSTEM WILL BRING WIND...RAIN AND POSSIBLY A FEW
STRONG THUNDERSTORMS TO THE AREA TODAY. RAIN WILL RETURN LATE
TUESDAY AND WEDNESDAY AFTER A BREAK MONDAY. THANKSGIVING DAY TO
THE END OF THE FORECAST PERIOD LOOKS DRY AND COLD.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 345 AM SUNDAY...S/W UPPER RIDGE ACROSS THE AREA ATTM...WILL
GIVE WAY TO THE APPROACH OF A POTENT SOUTHERN STREAM S/W
TROF FROM THE GULF COAST STATES THIS AFTN. MODELS INDICATE A
NEGATIVELY TILT TO THIS UPPER S/W TROF AS IT LIFTS FROM THE FL
PANHANDLE NORTHEASTWARD ACROSS THE CAROLINAS THIS EVENING AND
OVERNIGHT.
THE SFC WARM FRONT SOMEWHAT WELL DISPLACED FROM THE SFC LOW THAT
IS MOVING NNE ACROSS THE CENTRAL U.S. TO THE GREAT LAKES BY MONDAY
DAYBREAK. WHATS LEFT OF A WEAK WEDGE ACROSS THE INLAND CWA THIS
MORNING WILL GIVE TO THE APPROACHING WARM FRONT THIS AFTN...WHICH
LIFTS NORTHWARD ACROSS THE FA LATER THIS EVENING THROUGH THE EARLY
PRE-DAWN MON HOURS. STRATIFORM RAINS IE. EXCELLENT ISENTROPIC LIFT
AHEAD OF THE WARM FRONT AS MOISTURE FROM BOTH THE ATLANTIC AND
GULF OF MEXICO ARE UTILIZED. DECENT WIND DIRECTION VEERING
PROFILE FROM THE SFC TO 700 MB THIS AFTERNOON AND EVENING WITH
WIND SPEEDS RANGING FROM 20-30 KT AT THE SFC...UP TO 60 KT AT 925
MB. WITH WIND SHEAR LIKE THIS...ANY CONVECTION THAT TAPS INTO
THESE WINDS MAY PRODUCE DAMAGING WIND GUSTS OR EVEN THE
POSSIBILITY OF A TORNADO DUE TO FAVORABLE HELICITIES. WILL
CONTINUE TO MENTION THE SEVERE CONVECTIVE THREAT IN THE HWO.
OVERALL...THE AVBL INSTABILITY...IE. CAPE...WILL LIKELY BE THE
DETERMINING FACTOR FOR POTENTIAL CONVECTIVE DEVELOPMENT ACROSS
THE FA.
AN ABNORMAL DIURNAL TEMP CURVE WILL BE FORECAST THIS
PACKAGE...WITH TODAYS HIGHS LIKELY OCCURRING LATE THIS
AFTERNOON...AND TONIGHTS LOWS LIKELY THIS EVENING WITH STEADY OR
EVEN RISING TEMPS LATE THIS EVENING AND OVERNIGHT. ROUGHLY THE
FORECAST AREA WILL BE LOOKING AT 1 TO 2 INCH RAINFALL AMOUNTS
TODAY THROUGH DAYBREAK MON.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 330 AM SUNDAY...A BROAD SOUTHWEST FLOW ALOFT WILL CONTINUE
MONDAY AND TUESDAY WITH THE AFFECTS OF MASSIVE LOW PRESSURE OVER
THE GREAT LAKES LINGERING MONDAY. A WEAK PRESSURE TROUGH APPEARS
TO BE THE CATALYST FOR A FEW SHOWERS MONDAY WITH A DRY 24 HOURS OR
SO ENSUING.
THE SOUTHWEST FLOW WILL BE ENHANCED LATER TUESDAY AS A MID LEVEL
TROUGH MOVES INTO THE TENNESSEE VALLEY. A POTENT 300MB JET WITH THE
RIGHT ENTRANCE REGION BECOMING FAVORABLY PLACED LATER TUESDAY AND
EARLY WEDNESDAY WORKS IN TANDEM WITH A DEEP MOISTURE PLUME AND
WIDESPREAD RAIN DEVELOPS ONCE AGAIN. I HAVE INCREASED POPS FOR LATE
IN THE PERIOD TO ADDRESS. NO CHANGES TO THE TEMPERATURE FORECAST
WITH A WARM DAY IN STORE MONDAY COOLING SOME 10-15 DEGREES TUESDAY.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 330 AM SUNDAY...MEDIUM RANGE GUIDANCE CONTINUES TO PAINT A WET
SCENARIO FOR WEDNESDAY AS LOW PRESSURE...WELL OFFSHORE WITH
EXCELLENT UPPER LEVEL SUPPORT WORKS TOGETHER. IT HAS BEEN
INTERESTING SEEING HE 850MB ZERO ISOTHERM MOVING INTO THE AREA
WITH PRECIPITATION BUT SOUNDINGS SHOW THE LOWER LEVELS JUST A BIT
TOO WARM FOR ANY FROZEN PRECIPITATION. I RAISED POPS INCREMENTALLY
TO ADDRESS THE GOOD MODEL CONTINUITY AND INCREASED CONFIDENCE.
BEYOND THIS THE MID LEVEL PATTERN WILL BECOME ZONAL BY THE WEEKEND
WITH HIGH PRESSURE AT THE SURFACE FOR THE MOST PART. THERE WILL BE
A DRY COLD FRONT THAT MOVES ACROSS FRIDAY BUT LITTLE ELSE.
TEMPERATURES REMAIN BELOW CLIMATOLOGY THROUGHOUT.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
AS OF 12Z...A SLOW DETERIORATION OF CONDITIONS IS EXPECTED THROUGH THE
MORNING HOURS AS ISENTROPIC LIFT SLOWLY INCREASES. FIRST BATCH OF
PRECIP IS MOVING THROUGH THE REGION...POORLY DEPICTED BY THE HRRR BY
THE WAY. A SECOND AND MORE WIDESPREAD WAVE WITH MOVE THROUGH LATER
THIS MORNING. MODERATE RAIN WILL BE LIKELY WITH PRECIPITATION
INDUCED CEILINGS LOWERING TO IFR THIS AFTERNOON. ONLY MODERATE
CONFIDENCE WITH THE TIMING OF CEILINGS. MOST OF THE PRECIP TODAY
WILL BE STRATIFORM...HOWEVER COULD NOT RULE OUT A RUMBLE TOWARD
EVENING.
THIS EVENING...AN UPPER VORT MAX WILL SWEEP THROUGH THE REGION.
STRONG HELICITY BUT LITTLE TO NO CAPE WILL HARD TO RECONCILE.
BELIEVE THERE WILL BE A NARROW BAND OF CONVECTION THAT SHOULD PUSH
TO THE COAST BY 05-06Z. BEHIND THE VORT EXPECT THE PRECIP TO SHUT
OFF WITH MAINLY MVFR CEILINGS REMAINING.
EXTENDED OUTLOOK...UNSETTLED WEATHER IS EXPECTED MONDAY AND
POSSIBLY THROUGH TUESDAY...WITH OCCASIONAL SHOWERS AND MVFR/IFR
CONDITIONS. VFR LATE TUESDAY AFTERNOON WITH POSSIBLE MVFR
CONDITIONS WEDNESDAY. VFR THURSDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 415 AM SUNDAY...THE LOCAL WATERS WILL BE SUBJECT TO AN
EXTENDED PERIOD OF SCA CONDITIONS COMMENCING LATER THIS MORNING
AND LASTING INTO THE SHORT TERM PERIOD. INCREASING ONSHORE E TO
SE WINDS DURING TODAY...WILL VEER TO THE SOUTH AS THE WARM FRONT
LIFTS NORTHWARD ACROSS THE LOCAL WATERS FROM LATE THIS AFTN TO
MIDNIGHT TONIGHT. THE SFC PG WILL FURTHER TIGHTEN ACROSS THE LOCAL
WATERS AS THE PARENT LOW ACROSS THE CENTRAL U.S. DEEPENS AS IT
LIFTS TO THE GREAT LAKES BY MON DAYBREAK. LOOKING AT SPEEDS IN THE
15 TO 25 KT RANGE WITH GUSTS TO 30 KT THIS AFTERNOON...FURTHER
INCREASING TO 20 TO 30 KT WITH FEW GUSTS TO GALE FORCE. IF WATER
TEMPS WERE SLIGHTLY WARMER IN THE 60S INSTEAD OF THE 50S...A GALE
WARNING WOULD PROBABLY HAVE BEEN ISSUED...ALTHOUGH STILL NOT OUT
OF THE QUESTION...GIVEN THE PASSAGE OF A DECENT UPPER S/W TROF
ACROSS THE SE U.S. SIGNIFICANT SEAS WILL QUICKLY BUILD AS ONSHORE
WINDS MAKE SURE OF THAT. SIG. SEAS WILL PEAK THIS EVENING AND
OVERNIGHT...IN THE 8 TO 12 FOOT RANGE...FOLLOWED BY A VERY SLOW
SUBSIDING TREND THERE-AFTER IN SUBSEQUENT PERIODS. WIND DRIVEN
WAVES WILL DOMINATE SIGNIFICANT SEAS...WITH AVERAGE PERIODS IN THE
5.0 TO 6.5 SECONDS RANGE.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 330 AM SUNDAY...SMALL CRAFT CONDITIONS WILL CONTINUE MONDAY VIA
A STRONG SOUTHWEST FLOW OF 20-25 KNOTS AND SEAS OF 5-8 FEET. THE
WINDS WILL DIMINISH TUESDAY MORNING AND TURN TO THE WEST AS A WEAK
COLD FRONT PASSES. SEAS SHOULD FALL TO BELOW THE SMALL CRAFT
THRESHOLD SETTLING NICELY INTO A RANGE OF 2-4 FEET. ELEMENTS WILL
REMAIN TRANQUIL FOR THE REMAINDER OF THE PERIOD.
LONG TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 330 AM SUNDAY...FAIRLY BRISK NORTHWEST WINDS WEDNESDAY AS LOW
PRESSURE MOVES WELL OFFSHORE. SPEEDS WILL BE 20-25 KNOTS. WINDS
DIMINISH DRAMATICALLY THURSDAY AS A WEAK WESTERLY FLOW DEVELOPS.
SEAS WILL BE HIGHEST WEDNESDAY WITH 3-7 FEET...HIGHEST OFFSHORE.
VALUES DROP TO 2-4 FEET THURSDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 6 AM EST
TUESDAY FOR AMZ250-252-254-256.
&&
$$
SYNOPSIS...SHK
NEAR TERM...DCH
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...43
AREA FORECAST DISCUSSION
NWS MEDFORD OR
420 AM PST SUN NOV 23 2014
UPDATED AVIATION AND MARINE DISCUSSIONS
.DISCUSSION...
SEVERAL SNOTELS NORTH OF HIGHWAY 140 FROM FOURMILE LAKE NORTH TO
SUMMIT LAKE RELIABLY INDICATE BETWEEN 3 AND 6 INCHES OF NEW SNOW
ACCUMULATED IN THE LAST 24 HOURS BETWEEN 5000 FOOT AND 6200 FOOT
ELEVATIONS. WE EXPECT TO HAVE A NEW REPORT FROM CRATER LAKE
NATIONAL PARK LATER THIS MORNING, WHICH MAY HAVE RECEIVED A LITTLE
MORE THAN TEHSE MENTIONED SNOTELS. FURTHER SOUTH, FROM LAKE OF
THE WOODS TO MOUNT ASHLAND, SNOW REPORTS ABOVE 5000 FEET WERE 1 TO
3 INCHES.
THIS MORNING A 100 TO 130 KNOTS JET STREAM IS STILL PRESENT OVER
THE FORECAST AREA AT 30,000 FT MSL. THIS JET IS STREAMING HIGH
CLOUDS ACROSS THE AREA, WITH LOWER CLOUDS AND SOME FOG BELOW AT
MANY LOCATIONS. WE EXPECT THAT THESE CLOUDS WILL CONTINUE ACROSS
THE FORECAST AREA THROUGH MUCH OF THE DAY AS THE JET STREAM
REMAINS NEARLY STATIONARY, AND ACTUALLY STRENGTHENS SOME TO
120-145 KNOTS.
TODAY AND THEN MORE SO TONIGHT THROUGH TUESDAY THERE SUBSTANTIAL
DISAGREEMENT AMONGST THE MODELS AS TO HOW MUCH PRECIPITATION WILL
FALL ACROSS THE AREA AND WHERE IT WILL FALL. THE HRRR IS
INDICATING PRECIPITATION ALONG THE COAST AND COAST RANGE TODAY.
THE NAM AND SREF MODELS SHOW WIDESPREAD LIGHT PRECIPITATION
BEGINNING THIS EVENING AND CONTINUING THROUGH TUESDAY AFFECTING
NEARLY ALL OF THE FORECAST AREA, AT TIMES, WHEREAS THE GFS AND
ECMWF SHOW LESSER AMOUNTS AND KEEP IT MORE IN THE CASCADES, UMPQUA
BASIN, AND THE OREGON CASCADES. THIS PATTERN IS A FAVORABLE ONE
FOR LIGHT OVERRUNNING PRECIPITATION. WE OFTEN TERM IT A `HIGH
PRECIPITATION PROBABILITY, BUT LOW QPF` TYPE OF EVENT WHEN THIS
PATTERN OCCURS. HOWEVER, GIVEN MODEL DIFFERENCES, WHILE POPS HAVE
BEEN INCREASED, THEY MAY NEED TO BE INCREASED A BIT MORE,
ESPECIALLY IN THE HIGHER CONFIDENCE AREAS MENTIONED. IT IS NOTABLE
THAT THE 06Z GFS HAS TRENDED MORE TOWARD THE NAM12 AND SREF AND
THE THE 06Z NAM12 STUCK TO THE SAME SOLUTION AS WAS DEPICTED ON
THE 00Z RUN. THIS LENDS INCREASING CONFIDENCE IN THE WETTER NAM12
AND SREF SOLUTIONS. WITH THIS LIGHT PRECIPITATION, SNOW LEVELS
WILL BE OF SOME CONCERN, THOUGH IT APPEARS THAT THE OVERRUNNING IS
WEAK ENOUGH THAT WE SHOULD BE LOOKING AT RAIN AND SNOW RATHER THAN
ANY FREEZING RAIN.
SUNDAY THROUGH WEDNESDAY TEMPERATURES WILL BE WARMING
SIGNIFICANTLY ALOFT. IN FACT, THEY WARM TO ABOVE FREEZING TO ABOUT
THE 11,000 FOOT LEVEL. LOW DEWPOINTS SHOULD HELP TO PROTECT THE
SNOW PACK FROM TOO MUCH LOSS, BUT IT WILL STILL BE VERY NOTABLY
WARM. DUE TO GENERALLY LIGHT WINDS, HAVE UNDERCUT MODEL
TEMPERATURES GUIDANCE FOR HIGHS AT INTERIOR VALLEY LOCATIONS FOR
THIS TIME PERIOD.
IT DOES STILL LOOK LIKE A RETURN TO WET WEATHER THIS UPCOMING
WEEKEND. DETAILS ARE STILL TO BE DETERMINED, BUT SNOW LEVELS
LOOK AS IF THEY ARE MOST LIKELY TO BE ON THE HIGH SIDE WITH THAT
FRONTAL SYSTEM. IT CURRENTLY APPEARS THESE SNOW LEVELS WILL
REMAIN ABOVE THE PRIMARY MOUNTAIN PASSES THROUGH NEXT WEEKEND. BTL
&&
.AVIATION...BASED ON THE 23/12Z TAF CYCLE...LOW LEVEL MOISTURE
COMBINED WITH HIGH CLOUDS AND WEAK STABILITY IS BRINGING A MIX OF
LOW CLOUDS AND FOG IN INLAND VALLEYS THIS MORNING. EXPECT IFR/LIFR
CIGS/FOG IN THE VALLEYS WEST OF THE SOUTHERN OREGON CASCADES,
INCLUDING KMFR AND KRBG AND POSSIBLY IN NORTHERN CALIFORNIA THIS
MORNING. EAST SIDE AREAS WILL HAVE A MIX OF VFR AND MVFR CIGS THIS
MORNING. ALONG THE COAST, EXPECT MAINLY VFR CONDITIONS WITH LOCAL
MVFR CIGS. CONDITIONS ARE EXPECTED TO IMPROVE TO VFR THIS AFTERNOON
AND CONTINUE INTO THIS EVENING. THEN OVERNIGHT, EXPECT AREAS OF
VALLEY IFR CIGS IN PATCHY FOG TO DEVELOP FOR AREAS WEST OF THE
CASCADES. /CC
&&
.MARINE...UPDATED 4AM PST SAT NOV 22 2014... STEEP WEST SWELL WILL
PERSIST TODAY INTO MONDAY, THEN SLOWLY DIMINISH MONDAY EVENING AND
TUESDAY. A WARM FRONT WILL LIFT NORTHWARD THROUGH THE WATERS SUNDAY
NIGHT AND MONDAY. WINDS ARE EXPECTED TO BE MAINLY LIGHT AND
SOUTHERLY AROUND 10 TO 20 KT ON MONDAY. ALTHOUGH AT LEAST ONE MODEL
SHOWS 25 KT SMALL CRAFT ADVISORY WINDS POSSIBLE MONDAY INTO MONDAY
EVENING. WEAK HIGH PRESSURE IS EXPECTED TUESDAY INTO WEDNESDAY.
THEN A COUPLE FRONTAL SYSTEMS WILL MOVE INTO THE WATERS WEDNESDAY
NIGHT THROUGH FRIDAY, BRINGING AN INCREASE IN SOUTH WINDS AND SEAS.
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
CA...NONE.
PACIFIC COASTAL WATERS...
- SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM PST MONDAY
FOR PZZ350-356-370-376.
$$
BTL/CC/MAS
AREA FORECAST DISCUSSION
NWS MEDFORD OR
406 AM PST SUN NOV 23 2014
.DISCUSSION...
SEVERAL SNOTELS NORTH OF HIGHWAY 140 FROM FOURMILE LAKE NORTH TO
SUMMIT LAKE RELIABLY INDICATE BETWEEN 3 AND 6 INCHES OF NEW SNOW
ACCUMULATED IN THE LAST 24 HOURS BETWEEN 5000 FOOT AND 6200 FOOT
ELEVATIONS. WE EXPECT TO HAVE A NEW REPORT FROM CRATER LAKE
NATIONAL PARK LATER THIS MORNING, WHICH MAY HAVE RECEIVED A LITTLE
MORE THAN TEHSE MENTIONED SNOTELS. FURTHER SOUTH, FROM LAKE OF
THE WOODS TO MOUNT ASHLAND, SNOW REPORTS ABOVE 5000 FEET WERE 1 TO
3 INCHES.
THIS MORNING A 100 TO 130 KNOTS JET STREAM IS STILL PRESENT OVER
THE FORECAST AREA AT 30,000 FT MSL. THIS JET IS STREAMING HIGH
CLOUDS ACROSS THE AREA, WITH LOWER CLOUDS AND SOME FOG BELOW AT
MANY LOCATIONS. WE EXPECT THAT THESE CLOUDS WILL CONTINUE ACROSS
THE FORECAST AREA THROUGH MUCH OF THE DAY AS THE JET STREAM
REMAINS NEARLY STATIONARY, AND ACTUALLY STRENGTHENS SOME TO
120-145 KNOTS.
TODAY AND THEN MORE SO TONIGHT THROUGH TUESDAY THERE SUBSTANTIAL
DISAGREEMENT AMONGST THE MODELS AS TO HOW MUCH PRECIPITATION WILL
FALL ACROSS THE AREA AND WHERE IT WILL FALL. THE HRRR IS
INDICATING PRECIPITATION ALONG THE COAST AND COAST RANGE TODAY.
THE NAM AND SREF MODELS SHOW WIDESPREAD LIGHT PRECIPITATION
BEGINNING THIS EVENING AND CONTINUING THROUGH TUESDAY AFFECTING
NEARLY ALL OF THE FORECAST AREA, AT TIMES, WHEREAS THE GFS AND
ECMWF SHOW LESSER AMOUNTS AND KEEP IT MORE IN THE CASCADES, UMPQUA
BASIN, AND THE OREGON CASCADES. THIS PATTERN IS A FAVORABLE ONE
FOR LIGHT OVERRUNNING PRECIPITATION. WE OFTEN TERM IT A `HIGH
PRECIPITATION PROBABILITY, BUT LOW QPF` TYPE OF EVENT WHEN THIS
PATTERN OCCURS. HOWEVER, GIVEN MODEL DIFFERENCES, WHILE POPS HAVE
BEEN INCREASED, THEY MAY NEED TO BE INCREASED A BIT MORE,
ESPECIALLY IN THE HIGHER CONFIDENCE AREAS MENTIONED. IT IS NOTABLE
THAT THE 06Z GFS HAS TRENDED MORE TOWARD THE NAM12 AND SREF AND
THE THE 06Z NAM12 STUCK TO THE SAME SOLUTION AS WAS DEPICTED ON
THE 00Z RUN. THIS LENDS INCREASING CONFIDENCE IN THE WETTER NAM12
AND SREF SOLUTIONS. WITH THIS LIGHT PRECIPITATION, SNOW LEVELS
WILL BE OF SOME CONCERN, THOUGH IT APPEARS THAT THE OVERRUNNING IS
WEAK ENOUGH THAT WE SHOULD BE LOOKING AT RAIN AND SNOW RATHER THAN
ANY FREEZING RAIN.
SUNDAY THROUGH WEDNESDAY TEMPERATURES WILL BE WARMING
SIGNIFICANTLY ALOFT. IN FACT, THEY WARM TO ABOVE FREEZING TO ABOUT
THE 11,000 FOOT LEVEL. LOW DEWPOINTS SHOULD HELP TO PROTECT THE
SNOW PACK FROM TOO MUCH LOSS, BUT IT WILL STILL BE VERY NOTABLY
WARM. DUE TO GENERALLY LIGHT WINDS, HAVE UNDERCUT MODEL
TEMPERATURES GUIDANCE FOR HIGHS AT INTERIOR VALLEY LOCATIONS FOR
THIS TIME PERIOD.
IT DOES STILL LOOK LIKE A RETURN TO WET WEATHER THIS UPCOMING
WEEKEND. DETAILS ARE STILL TO BE DETERMINED, BUT SNOW LEVELS
LOOK AS IF THEY ARE MOST LIKELY TO BE ON THE HIGH SIDE WITH THAT
FRONTAL SYSTEM. IT CURRENTLY APPEARS THESE SNOW LEVELS WILL
REMAIN ABOVE THE PRIMARY MOUNTAIN PASSES THROUGH NEXT WEEKEND. BTL
&&
.AVIATION...FOR THE 23/06Z TAF CYCLE...THERE IS LOW CONFIDENCE IN
WHETHER THERE ARE CIGS VERSUS FOG OVERNIGHT INTO SUNDAY MORNING DUE
TO UNCERTAIN STABILITY PARAMETERS. USUALLY AFTER A RAIN EVENT,
IT IS TOO UNSTABLE THE FIRST NIGHT FOR WIDESPREAD FOG TO FORM.
HOWEVER, MANY AREAS HAVE CLEARED THIS EVENING, AND THE BOUNDARY
LAYER IS VERY MOIST. THIS COULD SPELL FOG IN AREAS THAT STABILIZE.
THERE SHOULD BE AT LEAST SOME IFR/LIFR CIGS/FOG IN THE VALLEYS
WEST OF THE CASCADES, INCLUDING KMFR AND KRBG AND ALSO IN NORTHERN
CALIFORNIA. EAST SIDE AREAS AND THE COAST WILL HAVE A MIX OF VFR
AND MVFR CIGS, THOUGH PATCHY IFR CANNOT BE RULED OUT THERE EITHER.
SPILDE
&&
.MARINE...UPDATED 8PM PST SAT NOV 22 2014...
WESTERLY SWELL WILL PERSIST THE REMAINDER OF THIS WEEKEND THEN
SLOW DIMINISH INTO NEXT WEEK. A WARM FRONT WILL LIFT NORTHWARD
THROUGH THE WATERS SUNDAY NIGHT INTO MONDAY WITH LIGHT SOUTH WINDS
AND SOME LIGHT RAIN. MAINLY LIGHT SOUTH TO SOUTHWEST WINDS ARE
EXPECTED THROUGH MIDWEEK. A FRONTAL SYSTEM WILL MOVE IN WEDNESDAY
NIGHT INTO THURSDAY THAT MAY BRING AN INCREASE IN SOUTH WINDS AND
SEAS. UNSETTLED WEATHER IS EXPECTED LATE THIS WEEK INTO THE
WEEKEND. SPILDE
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
CA...NONE.
PACIFIC COASTAL WATERS...
- SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM PST MONDAY
FOR PZZ350-356-370-376.
$$
BTL/CC/MAS
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
530 AM CST SUN NOV 23 2014
.UPDATE...
UPDATED FOR 12Z AVIATION DISCUSSION BELOW.
&&
.PREV DISCUSSION... /ISSUED 438 AM CST SUN NOV 23 2014/
EARLY THIS MORNING...A MESOSCALE CONVECTIVE SYSTEM WAS MOVING
EASTWARD ALONG THE NORTHWEST GULF AHEAD OF A STRONG UPPER LEVEL
TROUGH. MOST OF THE MIDSOUTH REMAINED RAIN FREE WITH JUST SOME
PATCHY LIGHT RAIN. A WEAK FRONT EXTENDED ACROSS NORTHEAST AR AND THE
MO BOOTHEEL. SOUTHEAST WINDS WERE PUSHING MILDER AIR INTO THE AREA
TO THE SOUTHEAST OF THE FRONT WITH SOME TEMPERATURES NEAR THE 60
DEGREE MARK.
THE UPPER LEVEL TROUGH WILL MOVE EAST NORTHEASTWARD ACROSS THE
MIDSOUTH TODAY WITH A STRENGTHENING SURFACE LOW TO OUR WEST. THE GFS
INDICATES A 987 MB LOW OVER SOUTHWEST MO AT SUNSET WHILE THE ECMWF
HAS THE PRESSURE AT 992 MB. MODELS ARE STILL SHOWING WIDESPREAD
SHOWERS MOVING QUICKLY INTO THE MIDSOUTH FROM THE SOUTHWEST TODAY.
THE HRRR MODEL INDICATES THAT THE ENTIRE FORECAST AREA WILL HAVE
SOME RAIN BY NOON THAT WILL THEN PERSIST INTO THE AFTERNOON BEFORE
DIMINISHING FROM THE SOUTHWEST. SHOWERS WILL HELP TO HOLD
TEMPERATURES DOWN. THIS INITIAL UPPER LEVEL TROUGH IS FORECAST TO BE
MOVING TO THE NORTHEAST OF THE REGION BY 6 PM. PRECIPITABLE WATER
VALUES WILL CLIMB TO AROUND 1.5 INCHES TODAY AS SOUTHERLY WINDS
SURFACE AND ALOFT TAP INTO GULF MOISTURE. WILL CONTINUE TO MENTION
THE THREAT OF LOCALLY HEAVY RAINFALL IN THE HAZARDOUS WEATHER
OUTLOOK WITH SOME HEAVY DOWNPOURS. MOST SPOTS ARE EXPECTED TO PICK
UP AROUND AN INCH OF RAIN BUT SOME LOCATIONS MAY SEE 1 1/2 INCHES.
INSTABILITY WILL BE MARGINAL AT BEST WITH THIS SYSTEM FOR MOST OF
OUR AREA. HOWEVER...MODELS DO INDICATE SOME ELEVATED INSTABILITY AND
MAYBE A LITTLE SURFACE BASED INSTABILITY DEVELOPING OVER NORTHEAST
AR AND THE MO BOOTHEEL LATE THIS AFTERNOON AND EVENING. THIS WILL BE
AHEAD OF THE SURFACE LOW OVER MO AND A COLD FRONT TRAILING TO THE
SOUTH. IN ADDITION...DIFFLUENCE ALOFT DEVELOPS OVER THE REGION AHEAD
OF A TRAILING UPPER LEVEL TROUGH. WILL MENTION A FEW STRONG
THUNDERSTORMS FOR THIS AREA LATE THIS AFTERNOON AND EARLY EVENING
WITH STRONG GUSTY WINDS AND SMALL HAIL POSSIBLE...ALTHOUGH A
LIMITING FACTOR WILL BE THAT SURFACE DEW POINTS WILL STRUGGLE TO
EVEN REACH THE 60 DEGREE MARK.
THE COLD FRONT WILL MOVE QUICKLY THROUGH THE MIDSOUTH TONIGHT WITH A
CONTINUED CHANCE OF SHOWERS ACROSS THE AREA. THE BEST CHANCE WILL BE
FROM PORTIONS OF NORTHEAST AR AND THE MO BOOTHEEL INTO PORTIONS OF
NORTHWEST TN WHERE THE BEST UPPER LEVEL DYNAMICS WILL OCCUR WITH
THE SECONDARY UPPER LEVEL TROUGH. WINDS WILL INCREASE AND TURN TO
THE SOUTHWEST AND WEST TONIGHT INTO MONDAY. FOR NOW...HAVE THE WIND
SPEEDS JUST SHY OF NEEDING A WIND ADVISORY FOR A LARGE SECTION OF
THE AREA. WILL ADD TO THE HAZARDOUS WEATHER OUTLOOK THAT A WIND
ADVISORY MAY BECOME NECESSARY. NORTHEAST MS LOOKS TO BE THE AREA
LEAST LIKELY TO NEED A WIND ADVISORY.
COOLER AND DRIER AIR WILL SPREAD INTO THE AREA MONDAY ON BREEZY
WESTERLY WINDS. SKIES WILL BECOME PARTLY TO MOSTLY SUNNY.
TEMPERATURES WILL ONCE AGAIN DROP TO BELOW NORMAL LEVELS AND
CONTINUE THAT WAY FOR AT LEAST A FEW DAYS. KEPT THE FORECAST
PRECIPITATION FREE THROUGH SATURDAY. THE GFS DOES INDICATE A WEAK
CLIPPER TYPE SYSTEM MOVING ACROSS THE AREA WEDNESDAY BUT MOISTURE
LOOKS LIMITED WITH MAINLY JUST AN INCREASE IN MIDDLE LEVEL CLOUDS
EXPECTED.
THE ECMWF AND GFS ARE SIGNIFICANTLY DIFFERENT BEGINNING THANKSGIVING
DAY. THE ECMWF SHOWS MODIFIED ARCTIC AIR SLOWLY PUSHING INTO THE
AREA FROM THE NORTH THURSDAY AFTERNOON THROUGH SATURDAY. THE GFS
PUSHES THE COLD HIGH TO THE EAST WITH WINDS TURNING TO THE SOUTH
ACROSS THE MIDSOUTH. THIS RESULTS IN HUGH DIFFERENCES IN
TEMPERATURES FOR THE REGION...ALTHOUGH CHANCES FOR PRECIPITATION
LOOK SMALL WITH EITHER SCENARIO. FOR NOW...KEPT CLOSE TO THE
EARLIER FORECAST EXCEPT BLENDED THE TEMPERATURES A LITTLE BETTER
WITH SURROUNDING OFFICES.
JCL
.AVIATION...
12Z TAF CYCLE
CIGS WILL CONTINUE TO LOWER EARLY THIS MORNING TO MVFR CONDITIONS
AS A LARGE SHIELD OF RAINFALL APPROACHES FROM THE SOUTHWEST.
MODERATE RAINFALL WILL OVERSPREAD ALL TERMINALS BY
14/15Z...DEPENDING ON THE TERMINAL. INTERMITTENT IFR CONDITIONS
ARE LIKELY AS CIGS CONTINUE TO LOWER IN PRECIP. A GOOD SIGNAL
EXISTS FOR LOWERED VISBYS AS WELL...ESPECIALLY AT TUP WHERE BETTER
LOW LEVEL MOISTURE IS ALREADY IN PLACE. FOR THIS REASON...HAVE
INSERTED BR AT ALL TERMINALS THROUGH 00Z. BEST CHANCE FOR
THUNDERSTORMS EXISTS AT MKL AND TUP THROUGH THE EARLY
AFTERNOON. ATMOSPHERIC INSTABILITY AT MEM AND JBR DOES NOT LOOK
SUPPORTIVE OF THUNDER MENTION AT THIS TIME...BUT WILL WATCH TRENDS
THROUGH THE MORNING. SLOWLY RAISE CIGS AFTER 03-06Z AT ALL
TERMINALS AS WINDS INCREASE DRAMATICALLY FROM THE WEST WITH COLD
FRONTAL PASSAGE. THIS WILL OCCUR EARLIER AT WESTERN TERMINALS AND
LATER AT EASTERN TERMINALS. WINDS COULD GUST TOWARD 30KTS BEHIND
THE FRONT.
TVT
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
438 AM CST SUN NOV 23 2014
.DISCUSSION...
EARLY THIS MORNING...A MESOSCALE CONVECTIVE SYSTEM WAS MOVING
EASTWARD ALONG THE NORTHWEST GULF AHEAD OF A STRONG UPPER LEVEL
TROUGH. MOST OF THE MIDSOUTH REMAINED RAIN FREE WITH JUST SOME
PATCHY LIGHT RAIN. A WEAK FRONT EXTENDED ACROSS NORTHEAST AR AND THE
MO BOOTHEEL. SOUTHEAST WINDS WERE PUSHING MILDER AIR INTO THE AREA
TO THE SOUTHEAST OF THE FRONT WITH SOME TEMPERATURES NEAR THE 60
DEGREE MARK.
THE UPPER LEVEL TROUGH WILL MOVE EAST NORTHEASTWARD ACROSS THE
MIDSOUTH TODAY WITH A STRENGTHENING SURFACE LOW TO OUR WEST. THE GFS
INDICATES A 987 MB LOW OVER SOUTHWEST MO AT SUNSET WHILE THE ECMWF
HAS THE PRESSURE AT 992 MB. MODELS ARE STILL SHOWING WIDESPREAD
SHOWERS MOVING QUICKLY INTO THE MIDSOUTH FROM THE SOUTHWEST TODAY.
THE HRRR MODEL INDICATES THAT THE ENTIRE FORECAST AREA WILL HAVE
SOME RAIN BY NOON THAT WILL THEN PERSIST INTO THE AFTERNOON BEFORE
DIMINISHING FROM THE SOUTHWEST. SHOWERS WILL HELP TO HOLD
TEMPERATURES DOWN. THIS INITIAL UPPER LEVEL TROUGH IS FORECAST TO BE
MOVING TO THE NORTHEAST OF THE REGION BY 6 PM. PRECIPITABLE WATER
VALUES WILL CLIMB TO AROUND 1.5 INCHES TODAY AS SOUTHERLY WINDS
SURFACE AND ALOFT TAP INTO GULF MOISTURE. WILL CONTINUE TO MENTION
THE THREAT OF LOCALLY HEAVY RAINFALL IN THE HAZARDOUS WEATHER
OUTLOOK WITH SOME HEAVY DOWNPOURS. MOST SPOTS ARE EXPECTED TO PICK
UP AROUND AN INCH OF RAIN BUT SOME LOCATIONS MAY SEE 1 1/2 INCHES.
INSTABILITY WILL BE MARGINAL AT BEST WITH THIS SYSTEM FOR MOST OF
OUR AREA. HOWEVER...MODELS DO INDICATE SOME ELEVATED INSTABILITY AND
MAYBE A LITTLE SURFACE BASED INSTABILITY DEVELOPING OVER NORTHEAST
AR AND THE MO BOOTHEEL LATE THIS AFTERNOON AND EVENING. THIS WILL BE
AHEAD OF THE SURFACE LOW OVER MO AND A COLD FRONT TRAILING TO THE
SOUTH. IN ADDITION...DIFFLUENCE ALOFT DEVELOPS OVER THE REGION AHEAD
OF A TRAILING UPPER LEVEL TROUGH. WILL MENTION A FEW STRONG
THUNDERSTORMS FOR THIS AREA LATE THIS AFTERNOON AND EARLY EVENING
WITH STRONG GUSTY WINDS AND SMALL HAIL POSSIBLE...ALTHOUGH A
LIMITING FACTOR WILL BE THAT SURFACE DEW POINTS WILL STRUGGLE TO
EVEN REACH THE 60 DEGREE MARK.
THE COLD FRONT WILL MOVE QUICKLY THROUGH THE MIDSOUTH TONIGHT WITH A
CONTINUED CHANCE OF SHOWERS ACROSS THE AREA. THE BEST CHANCE WILL BE
FROM PORTIONS OF NORTHEAST AR AND THE MO BOOTHEEL INTO PORTIONS OF
NORTHWEST TN WHERE THE BEST UPPER LEVEL DYNAMICS WILL OCCUR WITH
THE SECONDARY UPPER LEVEL TROUGH. WINDS WILL INCREASE AND TURN TO
THE SOUTHWEST AND WEST TONIGHT INTO MONDAY. FOR NOW...HAVE THE WIND
SPEEDS JUST SHY OF NEEDING A WIND ADVISORY FOR A LARGE SECTION OF
THE AREA. WILL ADD TO THE HAZARDOUS WEATHER OUTLOOK THAT A WIND
ADVISORY MAY BECOME NECESSARY. NORTHEAST MS LOOKS TO BE THE AREA
LEAST LIKELY TO NEED A WIND ADVISORY.
COOLER AND DRIER AIR WILL SPREAD INTO THE AREA MONDAY ON BREEZY
WESTERLY WINDS. SKIES WILL BECOME PARTLY TO MOSTLY SUNNY.
TEMPERATURES WILL ONCE AGAIN DROP TO BELOW NORMAL LEVELS AND
CONTINUE THAT WAY FOR AT LEAST A FEW DAYS. KEPT THE FORECAST
PRECIPITATION FREE THROUGH SATURDAY. THE GFS DOES INDICATE A WEAK
CLIPPER TYPE SYSTEM MOVING ACROSS THE AREA WEDNESDAY BUT MOISTURE
LOOKS LIMITED WITH MAINLY JUST AN INCREASE IN MIDDLE LEVEL CLOUDS
EXPECTED.
THE ECMWF AND GFS ARE SIGNIFICANTLY DIFFERENT BEGINNING THANKSGIVING
DAY. THE ECMWF SHOWS MODIFIED ARCTIC AIR SLOWLY PUSHING INTO THE
AREA FROM THE NORTH THURSDAY AFTERNOON THROUGH SATURDAY. THE GFS
PUSHES THE COLD HIGH TO THE EAST WITH WINDS TURNING TO THE SOUTH
ACROSS THE MIDSOUTH. THIS RESULTS IN HUGH DIFFERENCES IN
TEMPERATURES FOR THE REGION...ALTHOUGH CHANCES FOR PRECIPITATION
LOOK SMALL WITH EITHER SCENARIO. FOR NOW...KEPT CLOSE TO THE
EARLIER FORECAST EXCEPT BLENDED THE TEMPERATURES A LITTLE BETTER
WITH SURROUNDING OFFICES.
JCL
&&
.AVIATION...
06Z TAF CYCLE
CIGS WILL GRADUALLY LOWER TO MVFR LEVELS TONIGHT
THEN TO IFR LEVELS AS STEADY RAIN BEGINS TOWARD MORNING.
THUNDERSTORMS ARE POSSIBLE AT MEM...MKL AND ESPECIALLY TUP
TOMORROW...ALTHOUGH NOT EXPECTED TO BE NUMEROUS. WILL INCLUDE VCTS
AT THESE 3 STATIONS AND KEEP AN EYE ON RADAR TO SEE IF PREVAILING
THUNDER IS NEEDED TOMORROW. ONCE RAIN BEGINS...IT SHOULD BE
RELATIVELY STEADY TOMORROW...MVFR VISIBILITY IS EXPECTED
THROUGHOUT THE DAY TOMORROW...POSSIBLE LOWERING TO IFR FOR BRIEF
PERIODS. SOUTHERLY WINDS WILL CONTINUE TOMORROW...INCREASING LATE
TOMORROW AFTERNOON TO 10-15KT WITH HIGHER GUSTS. WILL BRING
PREVAILING RAIN TO AN END AFTER SUNSET...BUT NOT COMFORTABLE WITH
AGGRESSIVELY IMPROVING CIGS AS SOME GUIDANCE SUGGESTS.
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS AMARILLO TX
546 AM CST SUN NOV 23 2014
.AVIATION...
12Z TAFS...A COLD FRONT WILL PUSH THROUGH THE PANHANDLES THIS
MORNING...WITH STRONG NORTH/NORTHWEST WINDS KICKING UP BEHIND IT.
WINDS WILL REACH SUSTAINED SPEEDS AROUND 30 KTS WITH GUSTS TO AROUND
40 KTS...BEFORE DISSIPATING LATE THIS AFTERNOON AS THE PRESSURE
GRADIENT BEGINS TO RELAX. AN AVIATION WEATHER WARNING WILL BE IN
EFFECT FOR KAMA FROM 14Z-22Z. A PERIOD OF MVFR CIGS IS EXPECTED
BEHIND THE FRONT...AND SOME LIGHT RAIN OR SNOW SHOWERS WILL ALSO BE
POSSIBLE FOR ABOUT A 4-HOUR PERIOD IN WAKE OF THE FRONT. COMBINATION
OF THE STRONG WINDS AND LIGHT PRECIPITATION...ALONG WITH POSSIBLE
BLDU...MAY RESULT IN SOME MVFR VSBYS. CONDITIONS WILL IMPROVE LATE
THIS AFTERNOON AS WINDS START TO DIMINISH AND VFR CONDITIONS RETURN
FOR THE REMAINDER OF THE TAF PERIOD.
KB
&&
.PREV DISCUSSION... /ISSUED 302 AM CST SUN NOV 23 2014/
DISCUSSION...
VIGOROUS UPPER LEVEL SHORT WAVE TROUGH CROSSING THE ROCKIES WILL
DRIVE A STRONG CANADIAN COLD FRONT THROUGH THE REGION THIS
MORNING. WINDS ARE EXPECTED TO REACH WIND ADVISORY CRITERIA
WITH THIS FRONT FROM LATE THIS MORNING INTO THE EARLY AFTERNOON.
SURFACE PRESSURE GRADIENT ALONG WITH 850MB AND 700 MB HEIGHT
GRADIENTS ALL POINT TO THE POTENTIAL OF SUSTAINED 35 MPH WINDS
WITH HIGHER GUSTS. HAVE ADDED THE MENTION OF BLOWING DUST WITH
THESE HIGHER WINDS AS WELL. MODELS HAVE ALSO COME IN WETTER WITH THIS
SYSTEM. LATEST TTU WRF AND HRRR MODELS SUGGEST THAT AT LEAST SOME
KIND OF BAND OF PRECIP WILL TRAVERSE THE PANHANDLES TODAY. HAVE GONE
AHEAD AND INCREASED THE POPS TO 30 PERCENT ACROSS THE PANHANDLES.
BELIEVE THAT THE PRECIP COULD BE RAIN OR SNOW. AS THE DAY WEARS ON
THE COLUMN COOLS QUITE A BIT. THE ENTIRE CLOUD LAYER REMAINS BELOW 0
DEGREES CELSIUS AND THERE IS MOISTURE IN THE -10 TO -20 DEGREE
CELSIUS RANGE TO HELP FORM SOME SNOW FLAKES. TEMPERATURES MAY
ACTUALLY HOLD STEADY OR FALL THIS AFTERNOON AS THICKNESSES CRASH. SO
WOULD NOT BE SURPRISED TO SEE SOME SNOW SHOWERS WITH TEMPERATURES IN
THE LOWER 40S.
A FEW SNOW SHOWERS MAY LINGER NEAR THE NEW MEXICO STATE LINE
TONIGHT IN THE BEST UPSLOPE AREA...BUT THEY WILL REMAIN LIGHT.
AFTER TONIGHT THIS SYSTEM MOVES OFF TO OUR EAST AND A NORTHWEST FLOW
ALOFT DOMINATES THE PANHANDLES FOR THE EARLY PART OF THE WEEK.
THE MODELS START TO DIFFER SOMEWHAT BY THANKSGIVING. THE GFS
BROADENS AN UPPER LEVEL RIDGE ACROSS THE SOUTHERN ROCKIES AND
SOUTHERN HIGH PLAINS. MEANWHILE...THE ECMWF TRIES TO CARVE OUT AN
UPPER LEVEL TROUGH FROM SOUTHWEST CANADA INTO THE CENTRAL
PLAINS...WHICH WOULD PUSH ANOTHER CANADIAN COLD FRONT THROUGH THE
AREA BY THANKSGIVING AFTERNOON LEAVING FRIDAY AND SATURDAY COLDER.
THE GFS DOES NOT BRING IN THE COLDER AIR UNTIL NEXT WEEKEND. FOR
NOW HAVE GONE WITH A COMPROMISE WITH THE TEMPERATURES. AT ANY RATE
THE MODELS REMAIN DRY AFTER TONIGHT.
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...WIND ADVISORY FROM 9 AM THIS MORNING TO 6 PM CST THIS EVENING
FOR THE FOLLOWING ZONES: ARMSTRONG...CARSON...
COLLINGSWORTH...DALLAM...DEAF SMITH...DONLEY...GRAY...
HANSFORD...HARTLEY...HEMPHILL...HUTCHINSON...LIPSCOMB...
MOORE...OCHILTREE...OLDHAM...POTTER...RANDALL...ROBERTS...
SHERMAN...WHEELER.
OK...WIND ADVISORY FROM 9 AM THIS MORNING TO 6 PM CST THIS EVENING
FOR THE FOLLOWING ZONES: BEAVER...CIMARRON...TEXAS.
&&
$$
08/15
YOU CAN SEE AN ILLUSTRATED VERSION OF THE FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1022 AM MST SUN NOV 23 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 454 AM MST SUN NOV 23 2014
...SNOW CONTINUES FOR THE MOUNTAINS TODAY...QUICK BURST OF RAIN AND
SNOW SHOWERS FOR PORTIONS OF THE SE PLAINS THIS MORNING...
UPPER TROF IS MOVING THROUGH WESTERN CO WITH HEAVY SNOW FALLING
ALONG THE CONTDVD BASED ON WEB CAMS. HAVE EVEN SEEN PERIODS OF
MODERATE SNOW ACROSS NORTHERN PORTIONS OF THE SAN LUIS VALLEY AT
SAGUACHE AND JUST SOUTH VILLA GROVE IN CDOT CAMS. MEANWHILE...COLD
FRONT HAS CROSSED THE PALMER DIVIDE AND STARTING TO SEE SNOW FILL IN
ACROSS EL PASO COUNTY AS OF 4 AM.
AS UPPER TROF CONTINUES TO MOVE FROM NORTHWEST TO SOUTHEAST ACROSS
COLORADO THIS MORNING...SHOULD SEE RAIN/SNOW SPREAD SOUTHEASTWARD
ACROSS THE PLAINS. MODELS ARE A LOT HEAVIER HANDED WITH
PRECIPITATION ACROSS THE PLAINS THAN THE RUNS FROM LAST NIGHT...AND
THAT LOOKS REASONABLE AS THE UPPER TROF LOOKS A LITTLE SHARPER...AND
WINDS BEHIND THE FRONT LOOK MORE NORTHERLY...AND EVEN A TAD
NORTHEASTERLY THIS MORNING. COLD FRONT SHOULD RACE THROUGH THE
SOUTHEAST PLAINS BY 12-13Z...WITH STRONG NORTH WINDS GUSTING TO 40
MPH AT TIMES. RAIN AND SNOW SHOWERS RACE SOUTHWARD BEHIND THE
FRONT...WITH PRECIPITATION MOST WIDESPREAD ACROSS THE PALMER DIVIDE
THROUGH 15Z...THEN ACROSS THE NRN RATON RIDGE AND LOWER EAST FACING
SLOPES OF THE WETS AND SANGRES THROUGH ROUGHLY 18Z. NAM12 AND
ESPECIALLY ITS 06Z RUN HAS REALLY COME IN HOT WITH SNOWFALL AMOUNTS
FOR THE SE MTS...INDICATING 5-10 INCHES ACROSS WESTERN
HUERFANO...SOUTHERN CUSTER AND WESTERN LAS ANIMAS COUNTIES THROUGH
THIS AFTERNOON. GFS SHOWS GENERALLY 2-4 INCHES. RAP13 HAS AROUND 2-
4 INCHES ACROSS NRN EL PASO...AND 1-6 ACROSS THE SE MTS/SRN I-25
CORRIDOR. WITH LINGERING INSTABILITY THROUGH THE AFTERNOON...HIGH
RES MODELS ARE PROBABLY CORRECT IN KEEPING CONVECTIVE BANDS OF SNOW
SHOWERS GOING THROUGH THE AFTERNOON IN AND NEAR THE MOUNTAINS. ONCE
THE MAIN UPPER LIFT MOVES EAST OF THE AREA AFTER 18Z...AREAL
COVERAGE OF SHOWERS SHOULD DECREASE CONSIDERABLY. THAT SAID...HAVE
SEEN CASES LIKE THIS WHERE A PERSISTENT NARROW BAND CAN ACCUMULATE
LOCALLY HEAVY AMOUNTS OF SNOW...WHILE A COUPLE MILES EITHER SIDE GET
NEXT TO NOTHING. SO THE CONVECTIVE WILD CARD WILL BE A CHALLENGE
WITH SNOWFALL AMOUNTS TODAY. EITHER WAY...NAM12 SEEMS TO BE
SUFFERING FROM TOO MUCH CONVECTION IN THE MODEL RESULTING IN AMOUNTS
THAT LOOK TOO HEAVY AND WIDESPREAD. HAVE TRENDED GRIDS TOWARDS A
RAP AND HRRR BLEND FOR NOW.
MEANWHILE...SNOW WILL CONTINUE TO FALL HEAVY ALONG THE CONTINENTAL
DIVIDE THROUGH THE MORNING BEFORE TAILING BACK SOME DURING THE
AFTERNOON AS UPPER FORCING WEAKENS. NORTHWEST FLOW WILL KEEP
OROGRAPHIC SNOW CONTINUING ACROSS THE CENTRAL MOUNTAINS THROUGH
TONIGHT...BUT ACCUMULATIONS REMAIN ON THE LIGHTER SIDE UNTIL THE
NEXT WAVE MOVES IN LATE TONIGHT AND CONTINUES INTO MONDAY. CURRENT
SET OF HEADLINES PARES OUT THE SOUTHWEST MOUNTAINS AT 5 PM AND THE
LOWER ELEVATIONS OF LAKE COUNTY AND WESTERN CHAFFEE COUNTY BY 11 PM
THIS EVENING. SUSPECT THESE MAY BE ABLE TO BE TAKEN DOWN
SOONER...BUT WITH THE POSSIBILITY FOR CONVECTIVE SNOW BURSTS IN THE
AFTERNOON...AM HESITANT TO MODIFY ENDING TIMES JUST YET. CENTRAL
MOUNTAIN HEADLINES ABOVE 11KFT CONTINUE THROUGH MONDAY
AFTERNOON...AND THIS SEEMS THE BEST WAY TO HANDLE THE EVENT GIVEN
THE PERSISTENT SNOW EVEN THOUGH IT MAY DECREASE IN INTENSITY FOR A
TIME THIS AFTERNOON AND EVENING. MEANWHILE...CONVECTIVE SNOW SHOWERS
ACROSS THE SE MTS/ADJACENT I-25 CORRIDOR SHOULD DIMINISH DURING THE
EVENING HOURS WITH DRY CONDITIONS RETURNING TO THE SE MTS BY
MIDNIGHT. -KT
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 454 AM MST SUN NOV 23 2014
PRIMARY LONGER TERM METEOROLOGICAL ISSUES ARE TEMPERATURES...GUSTY
WINDS AT TIMES AND POPS(PRIMARILY OVER THE CENTRAL MOUNTAINS AT
TIMES).
OTHER THAN GUSTY WINDS AND SNOW OVER PORTIONS OF THE CONTINENTAL
DIVIDE AT TIMES(ESPECIALLY OVER THE CENTRAL MOUNTAINS)...EXPECT A
BASICALLY DRY AND MILD METEOROLOGICAL PATTERN TO GRACE THE
CWFA...ESPECIALLY FROM TUESDAY INTO THANKSGIVING WEEKEND.
INITIALLY...ACCUMULATING SNOW AS WELL AS GUSTY WINDS ARE PROJECTED
TO CONTINUE OVER THE CENTRAL MOUNTAINS INTO AT LEAST MONDAY AS
ADEQUATE ATMOSPHERIC MOISTURE IN COMBINATION WITH ANOTHER UPPER
DISTURBANCE IMPACTS THE REGION...THEREFORE WILL CONTINUE THE
WINTER STORM WARNING FOR PUBLIC ZONES 58 AND 60 THROUGH MONDAY
AFTERNOON.
ELSEWHERE OVER THE FORECAST DISTRICT...LOW-GRADE TO NIL POPS AS
WELL AS LOCALIZED GUSTY WINDS ARE ANTICIPATED FROM MONDAY INTO
TUESDAY. IN ADDITION...GENERALLY BELOW SEASONAL TEMPERATURES ARE
ALSO PROJECTED OVER SOUTHERN COLORADO FROM MONDAY INTO AT LEAST
TUESDAY MORNING.
THEN...AS BASICALLY DRY NORTHWESTERLY TO ZONAL UPPER FLOW DEVELOPS
OVER THE FORECAST DISTRICT FROM WEDNESDAY INTO THANKSGIVING
WEEKEND...PROJECT THAT DRY CONDITIONS WILL BE COMMON-PLACE IN
COMBINATION WITH MILD TEMPERATURES.
REGARDING TEMPERATURES...RECENT GFS40 AND DGEX SOLUTIONS INDICATE
WARMER TEMPERATURES THAN THE LATEST ECMWF SOLUTION OVER EASTERN
PORTIONS OF THE FORECAST DISTRICT...ESPECIALLY FROM FRIDAY INTO
SATURDAY AS THE ECMWF SOLUTION ALLOWS COOLER EASTERLY FLOW TO
DEVELOP OVER THESE LOCATIONS DURING THIS TIME-FRAME.
HOWEVER...THE DGEX...ECMWF AND GFS40 SOLUTIONS ALL SUGGEST THAT
THANKSGIVING DAY SHOULD EXPERIENCE THE WARMEST TEMPERATURES
DURING THE LONGER TERM IN COMBINATION WITH DRY CONDITIONS.
FINALLY...THE STRONGEST WINDS DURING THE LONGER TERM ARE
ANTICIPATED FROM TUESDAY INTO WEDNESDAY MORNING AND THEN AGAIN
DURING THANKSGIVING WEEKEND AT TIMES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1013 AM MST SUN NOV 23 2014
MAIN AREA OF SNOW HAS SHIFTED SOUTH OF KCOS AND KPUB...AND WHILE
BOTH SITES MAY SEE SOME ISOLATED -SHSN REDEVELOP THIS
AFTERNOON...EXPECT CIGS/VIS TO REMAIN VFR THROUGH THE REMAINDER OF
THE DAY AND INTO TONIGHT. WINDS WILL CONTINUE OUT OF THE NORTH THE
NEXT 24 HRS...WITH OCCASIONAL GUSTS TO 25 KTS BOTH TERMINALS. AT
KALS...EXPECT VFR CONDITIONS AS THREAT OF -SHSN HAS JUST ABOUT
ENDED WITH MOST SNOWFALL REMAINING OVER THE MOUNTAINS DURING THE
AFTERNOON AND EARLY EVENING. OVER THE MOUNTAINS...AREAS OF
IFR/LIFR CONDITIONS DUE TO SNOW WILL PERSIST OVER THE
SANGRES/WETS/SRN I-25 CORRIDOR INTO THE EVENING...WITH MAINLY
SCATTERED SNOW SHOWERS AND PATCHY MVFR/IFR ELSEWHERE.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 5 PM MST THIS AFTERNOON FOR COZ064-
066-068.
WINTER WEATHER ADVISORY UNTIL 11 PM MST THIS EVENING FOR COZ059-
061.
WINTER STORM WARNING UNTIL 5 PM MST MONDAY FOR COZ058-060.
&&
$$
AVIATION...PETERSEN
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
416 PM CST SUN NOV 23 2014
.SHORT TERM...
244 PM CST
UNSEASONABLY WARM/MOIST AIRMASS CONTINUES TO ADVECT NORTH ACROSS THE
REGION THIS AFTN...AND LOOKS TO CONTINUE THROUGH TONIGHT. THE MAIN
CONCERN FOR THE OVERNIGHT WILL BE ON RAINFALL TOTALS AND IF THIS
WILL POSE ANY HYDRO CONCERNS.
STRONG WARM AIR ADVECTION THIS AFTERNOON HAS ALLOWED SFC TEMPS TO
WARM INTO THE 50S ACROSS MUCH OF THE FORECAST AREA WITH DEW POINTS
APPROACHING THE UPPER 40S/ARND 50. THE AXIS OF THE HEAVIER RAINFALL
THIS AFTN HAS SHIFTED TO THE NORTHWEST AND STRETCHES FROM CENTRAL
WISC SOUTHWEST THROUGH FAR EASTERN IOWA. HAVE NUDGED TEMPS OVERNIGHT
UP A TAD...AND EXPECT TEMPS TO REMAIN NEARLY CONSISTENT UNTIL CLOSER
TO DAYBREAK MON WHEN THE FRONTAL BOUNDARY BEGINS TO APPROACH THE
NORTHWEST CWFA. GUIDANCE CONTINUES TO SUGGEST THE LOW DROPPING
SOUTHEAST ACROSS THE UPPER MIDWEST AND THE SECONDARY ONE LIFTING
NORTH FROM THE SOUTHWEST...WILL CONVERGE ACROSS SOUTHWEST LOWER
MICHIGAN JUST BEFORE DAYBREAK MON. THE COLD FRONT WILL BE NEARING
THE WESTERN CWFA ARND DAYBREAK...AND STEADILY SLIDE EAST THRU THE
MORNING. ASSOCIATED WILL BE A SHARP THERMAL TROUGH THAT WILL CAUSE
TEMPS TO STEADILY FALL THROUGHOUT THE MORNING/AFTN. SO THE DAY MAY
START MILD...BUT BY MIDDAY THAT WILL CERTAINLY NOT BE THE CASE WITH
TEMPS GENERALLY IN THE UPR 20S/LOW 30S. PRECIP WILL BE QUICKLY
TRANSITIONING OVER FROM RAIN TO SNOW.
AS THE SNOW BEGINS MIDDAY ACROSS THE NORTHWEST...GUIDANCE HAS BEEN
RELATIVELY CONSISTENT THAT AT ONSET RATIOS WILL HOVER ARND 8:1 TO
9:1...THEN AS THE COLDER AIR ADVECTS IN THOSE RATIOS SHUD STEADILY
CLIMB TO 14:1-17:1 BY LATE MON AFTN/EARLY EVE. COMPOUNDING THE SETUP
WILL BE STEADILY INCREASING PRESSURE GRADIENT THAT WILL CREATE GUSTY
WINDS NEARING 30-35MPH. THERE IS A NARROW WINDOW WHERE SNOWFALL
RATES COULD NEAR 1-2"/HR FOR A COUPLE HOURS...MAINLY BETWEEN 2-4PM
CST AND MAINLY WEST OF A LASALLE TO CRYSTAL LAKE LINE. HAVE BUMPED
SNOW TOTALS UP TO 2-4" AND COULD SEE IN PORTIONS OF WINNEBAGO COUNTY
3-5" CLOSER TO THE WISC STATELINE IN NORTHERN WINNEBAGO COUNTY.
ELSEWHERE SNOW WILL BEGIN TO ACCUMULATE...BUT EXPECTING MUCH LESS
WITH PERHAPS AN INCH IN CHICAGO AND LESSER TOTALS FURTHER SOUTH.
500MB TROUGH AXIS PIVOTS OVERHEAD MON EVE...AND WILL SLOWLY BRING AN
END TO THE ACCUMULATING SNOW. THE BETTER MOISTURE WILL QUICKLY PEEL
OFF TO THE NORTHEAST LATE MON NGT...HOWEVER ENOUGH OMEGA/MOISTURE TO
KEEP MENTION OF LGT SNOW SHOWERS MON NGT.
OVERNIGHT LOWS MON DIP FALL TO THE LOW 20S TO MID 20S IN THE
SOUTHEAST.
BEACHLER
&&
.LONG TERM...
244 PM CST
TUESDAY THROUGH WEDNESDAY...
LARGE MID-LVL TROUGH WILL BE IN PLACE TUE/WED WITH A WEAK SFC RIDGE
LIFTING NORTH AND BRINGING A GRADUAL EROSION TO THE CLOUDS TUE
NGT/WED. UNFORTUNATELY THIS MAY BE SHORT LIVED AS GUIDANCE SUGGESTS
A QUICK SHORTWAVE WILL DROP SOUTH FROM CENTRAL CANADA INTO THE
NORTHERN PLAINS EARLY WED...AND APPROACH THE FORECAST AREA MIDDAY
WED. THIS SYSTEM COULD BRING ANOTHER PERIOD OF LIGHT SNOW WITH SOME
MINOR ACCUMULATIONS.
TEMPS TUE WILL REMAIN IN THE 20S...HOWEVER WITH SOME THINNING IN THE
CLOUDS FOR WED TEMPS COULD REBOUND INTO THE LOW/MID 30S. BUT IT WILL
HINGE UPON THE ARRIVAL OF THE NEXT MID-LVL WAVE AND CLOUD COVER.
THURSDAY THROUGH SATURDAY...
ENSEMBLES IN THE LONGER TERM CONTINUES TO POINT TOWARDS A TROUGH
CARVED OUT ACROSS THE GREAT LAKES/TENN VALLEY FOR THE SECOND HALF OF
THE WEEK...AND THEN BEGINS TO FLATTEN FOR THE SECOND HALF OF THE
WEEKEND. AT THIS TIME GUIDANCE SUGGESTS DRY AIR AND A SFC RIDGE
OVERHEAD FOR THANKSGIVING DAY. TEMPS WILL GENERALLY BE IN THE 20S
FOR THE BULK OF THE EXTENDED.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* RAIN WITH IFR CIGS AND VARIABLE 2-4SM VSBY THROUGH THE EVENING.
IFR LOWERS TOWARDS 500 FT EARLY EVENING. LIGHTER RAIN OR DRIZZLE
AND IFR CIGS/VSBY PERSISTS THROUGH THE NIGHT.
* SOUTHEAST WINDS TURN LIGHT SOUTHWEST OR EVEN VARIABLE LATE THIS
EVENING.
* WINDS VEERING SOUTHWEST TO WEST BY LATE TOMORROW MORNING AND
INCREASING TO 20G30KT BY AROUND NOON WITH OCCASIONAL HIGHER
GUSTS POSSIBLE.
* RAIN WILL TRANSITION TO SNOW DURG THE LATE MORNING TO EARLY
AFTERNOON HOURS...WITH LIGHT SNOW CONTINUING THROUGH THE
AFTERNOON.
MDB
//DISCUSSION...UPDATED 22Z...
NO MAJOR CHANGES IN FORECAST THINKING LATE THIS AFTERNOON WITH IFR
CIGS AND RAIN NOW SPREAD ACROSS THE TERMINALS. VSBY LOOKS TO
FLUCTUATE BETWEEN 2 AND 4SM WITH INTERMITTENT HIGHER VALUES AS
RAIN INTENSITY CHANGES. MOST INTENSE RAIN SHOULD FALL BETWEEN
ABOUT NOW AND MID EVENING. WIND TRENDS REMAIN ON TRACK BUT THERE
MAY BE A PERIOD OF LIGHT AND VARIABLE WINDS AS SURFACE LOW
PRESSURE PASSES NEARBY OR OVERHEAD EARLY TONIGHT.
MDB
FROM 18Z...
LATEST RADAR IMAGERY SHOWING AN AREA OF WIDESPREAD RAIN MOVING NWRN
ALG THE MISSISSIPPI RIVER AND OVER NWRN IL...WITH MORE SHOWERY
PCPN OVER NERN IL AND INTO NWRN IN. RFD WILL LIKELY SEE THE STEADY
RAIN INITIALLY...BUT BASED ON THE LATEST RADAR TRENDS...THE MORE
WIDESPREAD...STEADY RAIN SHOULD MOVE INTO THE CHICAGO AREA
TERMINALS THROUGH THE EARLY AFTERNOON HOURS. CIGS HAVE ALREADY
DROPPED TO MVFR AND ANTICIPATE THAT CIGS SHOULD CONTINUE TO LOWER
AS RAIN FALLS THROUGH THE STRATUS LAYER...SATURATING BASES
DOWNWARD AND ALLOWING CIGS TO DROP INTO IFR LEVELS THROUGH THE
AFTERNOON. AS THE STEADIER RAIN AND HIGHER DEWPOINTS CONTINUE TO
STREAM NEWD...VIS WILL BEGIN TO DROP S WELL...INITIALLY TO MVFR
LEVELS THROUGH THE EARLY AFTERNOON AND THEN TO IFR LEVELS BY LATE
AFTERNOON. IFR CONDITIONS SHOULD THEN PERSIST THROUGH THE EVENING
AND OVERNIGHT...AND POSSIBLE EVEN EXTEND THROUGH TOMORROW MORNING.
WINDS WILL START OUT SLY AT THE INITIAL TIME...BUT EXPECT
DIRECTION TO BECOME SELY BY LATE AFTERNOON AS A MID LEVEL IMPULSE
TRACKS NWD AND SFC LOW PRESSURE DEVELOPS OVER MISSOURI LATE
AFTERNOON INTO EARLY EVENING. THE LOW IS EXPECTED TO TRACK INTO
LOWER MICHIGAN BY MONDAY MORNING...CAUSING WINDS TO VEER TO SWLY
DURG THE MORNING HOURS. AN ASSOCIATED COLD FRONT SHOULD PASS
ACROSS THE REGION AS THE SFC LOW MOVES INTO LOWER MICHIGAN...AND
COLDER AIR WILL BEING TO FILTER ACROSS THE REGION THROUGH THE
MORNING AS WINDS CONTINUE TO VEER TO WLY BY EARLY AFTERNOON. THE
INFLUX OF COLDER AIR WILL CAUSE PCPN TO GRADUALLY SHIFT OVER TO A
RAIN/SNOW MIX BY LATE MORNING AND THEN CHANGE OVER TO ALL SNOW BY
ARND NOON. PCPN RATES WILL DECREASE FOLLOWING THE PASSAGE OF THE
COLD FRONT...BUT WINDS WILL QUICKLY INCREASE WITH GUSTS TO 30 KT
OR OR BY AROUND NOON AS WELL. THE COMBINATION OF LIGHT SNOW AND
STRONG WINDS WILL KEEP VIS RESTRICTED TO IFR LEVELS THROUGH MUCH
OF THE DAY TOMORROW.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* MEDIUM TO HIGH CONFIDENCE IN CIG/VIS TRENDS.
* HIGH CONFIDENCE IN PCPN TRENDS...BUT MEDIUM CONFIDENCE IN THE
TIMING OF THE TRANSITION FROM PREVAILING RAIN TO PREVAILING
SNOW.
* HIGH CONFIDENCE IN WIND TRENDS...BUT HAVE SOME CONCERN FOR GUSTS
HIGHER THAN 30-32KT TOMORROW AFTERNOON.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...SNOW SHOWERS LIKELY. GUSTY BUT DIMINISHING WEST WINDS.
TUESDAY...MVFR CIGS POSSIBLE WITH A FEW FLURRIES IN THE MORNING.
NORTHWEST WINDS.
WEDNESDAY...CHANCE OF SNOW. MVFR/IFR PSBL. SSE WINDS TURNING WEST.
THURSDAY...SCHC SNOW...OTHERWISE VFR. BREEZY NORTHWEST WINDS.
FRIDAY...SCHC SNOW.
SATURDAY...VFR.
KMD
&&
.MARINE...
237 PM...LOW PRESSURE OVER NORTHERN MINNESOTA WILL CONTINUE TO
WEAKEN AS IT REACHES WESTERN LAKE SUPERIOR THIS EVENING. LOW
PRESSURE OVER OKLAHOMA WILL MOVE NORTHEAST ACROSS THE LAKE TONIGHT
ABSORBING THE WEAKENING LOW OVER LAKE SUPERIOR. THE TRACK OF THIS
LOW HAS CONTINUED TO DRIFT A LITTLE FURTHER EAST WITH EACH RUN AND
THE LOW NOW PASSES EAST OF LAKE SUPERIOR...MOVING OVER EASTERN
ONTARIO MONDAY WITH A PRESSURE NEAR 28.8 INCHES. THIS WILL DELAY
THE ONSET OF GALES BY A FEW HOURS...UNTIL LATE MORNING ACROSS THE
SOUTHERN PART OF THE LAKE AND THEN TO LATE AFTERNOON ACROSS THE
NORTHERN PART. UPGRADED THE GALE WATCH TO A GALE WARNING FOR THE
SOUTH HALF BUT MAINTAINED THE WATCH ACROSS THE NORTHERN HALF.
GALES WILL DIMINISH BY DAYBREAK TUESDAY WITH WINDS STEADILY
DIMINISHING TUESDAY AS HIGH PRESSURE MOVES ACROSS THE SOUTHERN
LAKES AND OHIO VALLEY. ANOTHER LOW WILL MOVE ACROSS THE LAKES
REGION WEDNESDAY AFTERNOON INTO WEDNESDAY NIGHT. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER WEATHER ADVISORY...ILZ003-ILZ004-ILZ008-ILZ010-
ILZ011...NOON MONDAY TO MIDNIGHT TUESDAY.
WINTER WEATHER ADVISORY...ILZ005-ILZ006-ILZ012...3 PM MONDAY TO
MIDNIGHT TUESDAY.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-
LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ870-LMZ872-
LMZ874-LMZ876-LMZ878...9 AM MONDAY TO 3 AM TUESDAY.
GALE WATCH...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-LMZ567-
LMZ868...3 PM MONDAY TO 3 AM TUESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
[top]
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
314 PM CST Sun Nov 23 2014
.SHORT TERM...(Tonight)
ISSUED AT 313 PM CST SUN NOV 23 2014
Deepening 993 mb low pressure between Oklahoma City and Tulsa at mid
afternoon will strengthen further as it ejects northeast across
central IL near or east of I-55 during this evening, and into
northern lower MI overnight at it deepens to 979 mb. Widespread
light to moderate rain showers have spread NNE across central/se IL
early this afternoon. Still no reports of thunder over IL but will
continue to carry isolated thunderstorms over eastern IL into this
evening as deepening low pressure approaches.
Showers will break up later this evening and overnight east of the
IL river while deformation zone of precipitation lingers west of the
IL river. Strong cold front sweeps across central and eastern IL
during overnight, passing through the Wabash river valley early
Monday morning. Light rain to mix with light snow nw of the IL river
late tonight and change to snow early Monday morning as temps fall
into the mid 30s. Temperatures currently in the low to mid 50s and
dewpoints are in the upper 40s and lower 50s. Lows tonight to range
from mid 30s from Peoria and Springfield west, to the mid to upper
40s near the IN/IL border with temps continue to drop Monday
morning. Southeast winds 10-17 mph and gusts of 18-25 mph this
afternoon to subside this evening to around 10 mph or less as low
pressure moves in. But as low deepens and pulls away from central/se
IL overnight, winds will turn westerly behind the cold front and
increase to 15-25 mph and gust 25 to 30 mph later tonight. RUC model
shows even higher wind gusts of 35-40 mph going into southeast IL
behind cold front early Monday morning around sunrise. MET/MAV
guidance shows strongest winds during the day Monday (strongest in
eastern IL) after 15Z/9 am Monday.
&&
.LONG TERM...(Monday through Sunday)
ISSUED AT 313 PM CST SUN NOV 23 2014
The strong low pressure area will continue to lift northeast through
the Great Lakes area with a very strong pressure gradient behind the
system. In addition, gusty westerly winds and strong cold air
advection (CAA) will move into the area Monday. Expecting rain in
the eastern half of the CWA and a mix of rain and snow in the
western half,in the morning. Then as the CAA occurs, the all snow
line will move across the area from west to east, so that by early
afternoon, most of the CWA will be all snow, with the mix of rain
and snow only in the eastern parts of the CWA. By late afternoon,
the whole area will be cold enough for snow. As the system lifts
northeast through the day, the higher chances of pcpn will move from
southwest to northeast. So, the areas mostly likely to see any
accumulation of snow will be Northwest of I-55 during the morning and
then north of a Galesburg to Bloomington line during the afternoon.
Total snowfall accumulation expected tomorrow will be an inch or
more northwest of a Macomb to Pontiac line; and then lesser amounts
southeast of that line. Highest amounts are expected to be 1.5 to 2
inches north of a Galesburg to Lacon line.
The tight gradient behind this system will also bring very gusty
winds to the CWA tomorrow, beginning tomorrow morning and lasting
through the day. Sustained winds or around 25 mph with gusts between
35 and 40 mph will be possible across the whole area tomorrow. Will
not be issuing a wind advisory as it will be just below criteria.
However, would not be surprised if overnight shift issues one in the
morning. The gusty winds will also create blowing snow, mainly in
the northern parts of the CWA, so visibilities could be reduced at
times.
Pcpn will end by tomorrow night as the low pressure area lifts
northeast into Canada. After this system, dry weather is expected
for Monday night through Tue night as brief high pressure area moves
through the CWA. Then another clipper system is expected to move
through the area and bring another chance of rain and/or snow for
Wednesday. There will be some warm air ahead of this system so the
pcpn type could be a mix before it changes to all snow. Any
accumulations with this system will be confined to the north with a
half inch or less possible...at this time. The remainder of the
forecast should be dry with temps below normal, as Canadian high
pressure moves in and dominates the weather through the rest of the
week and into the weekend.
Temps will steady or slowly falling tomorrow due to the strong CAA
expected. Then temps will be cool/cold most of the rest of the
forecast, except for Wed, just ahead of the next clipper system.
&&
.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
ISSUED AT 1155 AM CST SUN NOV 23 2014
MVFR ceilings of 1-2k ft have developed over central IL airports late
this morning and expect ceilings to lower to IFR during the
afternoon and tonight. VFR visibilities at midday lower to 2-4
miles during mid and late afternoon and continue tonight as rain
showers become more widespread and heavier. Currently no
thunderstorms over IL and nearby states, but isolated
thunderstorms still expected to develop this afternoon and
evening, though coverage too limited to pin point donw in the
TAFS. Rain showers to mix with or change to light snow from west
to east during Monday morning with vsbys as low as 1-2 miles at
PIA and BMI, while 2-4 miles vsbys further south along I-72. SSE
winds 12-17 kts with gusts 18-24 kts this afternoon to diminish
closer to 10 kts this evening and then veer sw by overnight and
WSW later tonight into Monday morning and increase to 17-22 kts
and gusts 25-30 kts by 15Z/9 am Monday.
Deepening 994 mb low pressure just north of Oklahoma City in
central OK at midday to turn northeast and track into central IL
this evening as it deepens to 987 mb. Low pressure then tracks
into western lower MI late tonight as it deepens further to 980 mb
and pulls a strong cold front east across central IL between 08Z-
12Z. Very tight pressure gradient behing cold front to bring the
strong WSW winds by Monday morning along with the colder air
changing the light rain to light snow and more widespread over
northern airports of PIA and BMI.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...07
LONG TERM...Auten
AVIATION...07
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
445 PM EST SUN NOV 23 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 444 PM EST SUN NOV 23 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A COMPLEX MID/UPPER LEVEL
TROUGH ACROSS THE CENTRAL CONUS. THE MORE PROMINENT SHORTWAVE
TROUGHS WERE LOCATED OVER THE DAKOTAS...NEW MEXICO...AND NRN
MS. AT THE SFC...A TROUGH AND FRONTAL BOUNDARY EXTENDED FROM NE
MN THROUGH CNTRL IA TO LOW PRES OVER ERN OK. A BROAD SRLY FLOW OF
GULF MOISTURE INTO THE NRN LAKES HAS RESULTED IN AREAS OF DENSE FOG
OVER THE EXTENSIVE SNOW COVER. A WEAKER SHRTWV OVER WI AND
ASSOCIATED 850-700 MB FGEN SUPPORTED AN AREA OF RAIN THAT WAS
EXPANDING INTO SRN UPPER MI.
TONIGHT...EXPECT THAT THE RAIN WILL CONTINUE TO DEVELOP INTO UPPER
MI THIS EVENING...ESPECIALLY ACROSS THE SE HALF IN PROXIMITY TO THE
STRONGEST FGEN AND ISENTROPIC LIFT. ALTHOUGH AREAS OF DENSE FOG MAY
PERSIST INTO THIS EVENING...THE RAIN SHOULD HELP SCOUR OUT SOME OF
THE FOG FOR SLIGHTLY BETTER VSBY. BY LATE TONIGHT...THE RAIN IS
EXPECTED TO CONTINUE TO INCREASE IN COVERAGE/INTENSITY AS THE MID
LEVEL TROUGH DEEPENS...THE MS SHRTWV LIFTS TO THE GREAT LAKES WITH
INCREASING 700-500 MB QVECTOR CONV.
MONDAY...MODELS SUGGEST THAT THERE MAY BE A LULL IN THE PCPN
BETWEEN THE EXITING NRN LAKE SHRTWV AND THE MID LEVEL TROUGH MOVING
IN FROM THE UPPER MS VALLEY. AS THE DEEPENING SFC LOW NEAR THE
STRAITS AT 12Z/MON LIFTS QUICKLY TO THE NE THE COLDER AIR WILL ALSO
SLIDE QUICKLY THROUGH UPPER MI WITH THE RAIN CHANGING OVER TO SNOW
FROM 12Z-21Z FROM W TO EAST. THE PCPN CHANGEOVER WAS DELAYED
SLIGHTLY...PER MODEL TRENDS WITH A BLEND OF THE 12Z NAM AND REGIONAL
GEM 1000-850 LOW LEVEL THICKNESS USED FOR THE RAIN SNOW LINE. WITH
THE LOSS OF THE STRONGER LARGE SCALE FORCING/LIFT TIL AFTERNOON
MAINLY JUST LIGHT TO MODERATE LAKE ENAHANCED SNOW IS EXPECTED OVER
THE WEST HALF FOR NNW FLOW FAVORED LOCATIONS AS 850 MB TEMPS FALL TO
NEAR -8C WEST BY 18Z AND TO AROUND -12C ACROSS WEST AND CNTRL
LOCATIONS BY 00Z. SNOWFALL AMOUNTS IN THE 2 TO 4 RANGE WILL BE
POSSIBLE OVER THE WEST WITH ONLY AROUND AN INCH CENTRAL. A TIGHT
GRADIENT BEHIND THE LOW WILL BRING STRONG NRLY WINDS INTO THE AREA
PRODUCING SOME BLOWING AND DRIFTING SNOW.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 303 PM EST SUN NOV 23 2014
AT 00Z TUE...A SHORTWAVE WILL BE E OF THE CWA WITH THE ASSOCIATED
SFC LOW NEAR JAMES BAY. A WEAKENING UPPER TROUGH WILL BE OVER THE
FAR WRN CWA...WITH A RIDGE NW OF THE TROUGH. THE 12Z/23 NAM HAS COME
INTO BETTER AGREEMENT WITH 12Z/23 GFS AND 00Z/23 ECMWF IN SHOWING
LESS PHASING BETWEEN THE TWO FEATURES...AND THEREFORE HAVING MOST
/BUT NOT ALL/ OF THE SYNOPTIC SNOW NE OF THE CWA BY 00Z TUE. PRECIP
WILL BE ALL SNOW BY 00Z TUE AS 850MB TEMPS WILL FALL TO AOB -12C BY
12Z. WITH THE COLD AIRMASS...LAKE ENHANCEMENT WILL OCCUR IN NNW WIND
SNOWBELTS ALONG AND AHEAD OF THE TROUGH THAT WILL MOVE THROUGH THE
CWA BY 18Z TUE. BEHIND THE TROUGH...WINDS BECOME INCREASINGLY
ANTICYCLONIC...AND LOW LEVEL AIRMASS DRIER...AS THE RIDGE MOVES IN.
WILL CERTAINLY SEE DIMINISHING PRECIP COVERAGE/INTENSITY LATER TUE
INTO TUE NIGHT...BUT LES WILL NOT COMPLETELY END AS LOW LEVEL WINDS
FOCUS LES MORE OVER THE KEWEENAW PENINSULA. WNW WIND SNOWBELTS OF
THE NRN HURON MOUNTAINS AND OVER ALGER COUNTY WILL BE FAVORED FOR
THE GREATEST SNOWFALL AMOUNTS...WITH EXPECTATIONS OF 6-8 INCHES OF
SNOW MON NIGHT AND TUE IN THESE FAVORED LOCATIONS. ELSEWHERE NEAR
LAKE SUPERIOR AROUND 4 INCHES IS EXPECTED MON NIGHT/TUE...WITH LESS
AMOUNTS OF 1-3 INCHES INLAND. AFTER COORDINATION WITH SHORT TERM
SHIFT...LAKE EFFECT SNOW ADVISORIES HAVE BEEN ISSUED FOR ALL
COUNTIES ALONG LAKE SUPERIOR. AT LEAST FOR MON NIGHT/TUE...SNOW TO
LIQUID RATIOS SHOULD BE HIGH ENOUGH FOR THE LAKE EFFECT HEADLINE
INSTEAD OF WINTER WEATHER ADVISORIES. ALSO...BLOWING SNOW WILL OCCUR
ALONG LAKE SUPERIOR.
CONFIDENCE DECREASES SIGNIFICANTLY FOR WED THROUGH NEXT WEEKEND. FOR
WED INTO THU...MODELS AGREE IN SHOWING TWO SHORTWAVES MOVING INTO
THE CENTRAL CENTRAL U.S. WED...BUT DISAGREE ON THE
STRENGTH/TRACK/PHASING OF THE TWO WAVES...WHICH LEADS TO A WIDE
VARIETY OF SOLUTIONS FOR THE CWA. THE ECMWF PHASES THE WAVES OVER
THE REGION...WHICH LEADS TO A 1003MB SFC LOW MOVING FROM NEAR MPX AT
12Z WED TO LAKE HURON AT 12Z THU. THIS SOLUTION WOULD RESULT IN
SIGNIFICANT SNOWFALL AMOUNTS ACROSS THE CWA WED INTO THU. THE GFS
KEEP THE WAVES OUT OF PHASE AND THE SRN MOST WAVE MUCH FARTHER
S...LEAVING JUST A LITTLE LAKE ENHANCEMENT WED INTO WED NIGHT AS THE
NRN SHORTWAVE CROSSES THE AREA. OTHER MODELS HAVE VARYING SOLUTIONS
BETWEEN THESE TWO EXTREMES. NOT REALLY ABLE TO PICK BETWEEN THE
MODELS GIVEN THE NORMAL LOW CONFIDENCE WITH SHORTWAVE ENERGY AND
GENERALLY GOOD RUN TO RUN CONTINUITY OF THE GFS AND ECMWF WITH THIS
SYSTEM.
REGARDLESS OF SOLUTION...SHOULD SEE LES THU INTO THU NIGHT IN NW
WIND SNOWBELTS UNDER -18C TO -20C 850MB TEMPS. HOWEVER...THE GFS
THEN BRINGS WINDS OUT OF THE SW THU NIGHT AHEAD OF A STRONG CLIPPER
SYSTEM IT SHOWS MOVING INTO THE NRN PLAINS THU NIGHT AND ACROSS THE
CWA FRI NIGHT. ALL THE WHILE...THE ECMWF SHOWS A STRONG SFC HIGH
MOVING FROM THE NRN PLAINS TO THE MID MISSISSIPPI VALLEY. THE ECMWF
WOULD KEEP LES GOING IN NW-WNW SNOWBELTS THROUGH FRI...WHILE THE GFS
SOLUTION WOULD OBVIOUSLY NOT GIVEN THE CHANGE IN WINDS WITH THE SFC
LOW MOVING ACROSS THE CWA AND 850MB TEMPS INCREASE TO AROUND
0C...BUT DOES BRING LES BACK ON SAT BEHIND THE CLIPPER. MODELS DO
SHOW SOME AGREEMENT IN LOW LEVEL WINDS BECOMING FROM THE WSW BY SUN
WITH CONTINUED /BUT LIGHTER/ LES. WILL STICK CLOSER TO THE PREVIOUS
FORECAST GIVEN THE HIGH UNCERTAINTY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1258 PM EST SUN NOV 23 2014
WITH LOW LEVEL MOIST/WARM ADVECTION CONTINUING INTO THE AREA
SHOULD...PERSISTENT LOW CIGS AND FOG WILL CONTINUE INTO TONIGHT.
VLIFR CONDITIONS BELOW LANDING MINS ARE LIKELY TO PERSIST THIS
AFTERNOON AT KSAW WITH THE UPSLOPE FLOW HELPING TO MAINTAIN THE
DENSE FOG. SOME IMPROVEMENT MAY BE POSSIBLE WHEN RAIN MOVES IN THIS
EVENING AND OVERNIGHT. CONFIDENCE IN TIMING WHEN THE FOG MAY DIMINISH
IS UNCERTAIN. OTHERWISE...IFR/LIFR CIGS WILL ALSO PERSIST AT IWD AND
CMX BUT SHOULD NOT BE AS LOW WITH A MORE DOWNSLOPE SRLY WIND
COMPONENT. AS A DEEP LOW PRESSURE SYSTEM MOVES EAST OF THE AREA
MONDAY MORNING WINDS WILL BECOME NORTH AND QUICKLY STRENGTHEN WITH
ANY RAIN CHANGING TO SNOW.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 444 PM EST SUN NOV 23 2014
WINDS WILL BE VARIABLE TONIGHT AS TROUGH CROSSES LAKE SUPERIOR. A
DEEPENING LOW WILL MOVE TO EAST OF LAKE SUPERIOR ON MONDAY.
NORTHERLY WINDS WILL INCREASE TO GALES 35-45 KTS BY MONDAY MORNING
INTO MONDAY NIGHT. EXPECT WINDS TO DIMINISH TO 25 KTS OR LESS
TUESDAY INTO WEDNESDAY...THEN INCREASE TO 30 KTS ON THURSDAY AS COLD
AIR POURS ACROSS LAKE SUPERIOR BETWEEN HIGH PRESSURE BUILDING OVER
THE NORTHERN PLAINS AND LOW PRESSURE CROSSING THE LOWER GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY FROM 4 PM MONDAY TO 4 PM EST TUESDAY
FOR MIZ006-007-085.
DENSE FOG ADVISORY UNTIL 7 PM EST /6 PM CST/ THIS EVENING FOR
MIZ004>007-010>014-085.
LAKE EFFECT SNOW ADVISORY FROM 7 AM EST /6 AM CST/ MONDAY TO 7
AM EST /6 AM CST/ TUESDAY FOR MIZ001>003-009.
LAKESHORE FLOOD ADVISORY FROM 11 AM MONDAY TO 6 AM EST TUESDAY
FOR MIZ001-003-005>007.
LAKE EFFECT SNOW ADVISORY FROM 1 PM MONDAY TO 1 PM EST TUESDAY
FOR MIZ004-005.
LAKE SUPERIOR...
GALE WARNING FROM 3 PM MONDAY TO 4 AM EST TUESDAY FOR LSZ251-267.
GALE WARNING FROM 10 AM MONDAY TO 4 AM EST TUESDAY FOR
LSZ246>250-265-266.
GALE WARNING FROM 6 AM MONDAY TO 2 AM EST TUESDAY FOR LSZ242>245-
263-264.
GALE WARNING FROM NOON EST /11 AM CST/ TO 9 PM EST /8 PM CST/
MONDAY FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
304 PM EST SUN NOV 23 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 523 AM EST SUN NOV 23 2014
MAIN FORECAST CONCERNS INCLUDE DENSE FOG THIS MORNING...TIMING THE
ONSET OF PCPN LATER TODAY AND THEN THE CHANGEOVER TO SNOW LATE
TONIGHT IN THE WEST.
WV IMAGERY AND RUC ANALYSIS SHOWS A VIGOROUS SRN STREAM SHORTWAVE
OFF THE TX GULF COAST WITH A STRONG SHORTWAVE AND ASSOC 150+ KNOT
250 MB JET MOVING OFF THE PAC NW INTO NRN NEVADA. ANOTHER SHORTWAVE
TROUGH WAS MOVING INTO WRN ND. AT THE SFC...SRLY FLOW PREVAILED FROM
THE GULF TOWARD THE UPPER MS VALLEY AND NRN GREAT LAKES REGION BTWN
HIGH PRES OVER THE MID ATLANTIC AND A 993 MB LOW OVER ND. WAA AND
LOW CLOUD COVER HAVE MAINTAINED TEMPS IN THE MID AND UPPER 30S
ACROSS UPPER MI EARLY THIS MORNING. THE WARM AIR MOVING OVER THE
MOSTLY SNOWPACKED GROUND HAS ALSO RESULTED IN DENSE FOG ACROSS MUCH
OF THE ERN TWO THIRDS OF UPPER MI THIS MORNING.
TODAY...EXPECT PCPN CHANCES TO GRADUALLY INCREASE THROUGH THE DAY AS
STRONG MOISTURE ADVECTION/TRANSPORT CONTINUES AND 850-700 MB FGEN
INCREASES. EXPECT THE BETTER CHANCE FOR RAIN OVER THE SOUTH CENTRAL
AND EAST IN PROXIMITY TO THE STRONGER DYNAMICS AND BEST MOISTURE. AS
THE MID-LVL DRY LAYER MOISTENS UP ANY DRIZZLE SHOULD CHANGE OVER TO
RAIN BY MID TO LATE AFTERNOON. EXPECT TEMPS WILL CLIMB ABOVE NORMAL
INTO THE LOW TO MID 40S. WARM AIR MOVING OVER THE COLD SNOW PACK HAS
RESULTED IN DENSE FOG THIS MORNING SO HAVE POSTED A DENSE FOG
ADVISORY THROUGH 16Z FOR ALL BUT THE FAR FOUR WESTERN COUNTIES OF
THE CWA.
TONIGHT...CONTINUED INCREASE IN DEEP LAYER Q-VECT
CONVERGENCE...DEVELOPMENT OF COUPLED UPPER JET STRUCTURE AND
ENHANCED 850-700 MB FGEN WILL LEAD TO WIDESPREAD RAINFALL ACROSS
MUCH OF THE CWA BY EVENING. MODEL AVERAGED QPF RANGES FROM .25 WEST
TO .75 SOUTHEAST. MODEL SNDGS AND CRITICAL 1000-850 MB THICKNESSES
SUGGEST RAIN WILL BEGIN TO SWITCH OVER TO SNOW FAR WEST AROUND 09Z
BUT WITH SNOW/WATER RATIOS RISING TO ONLY AROUND 6-7/1 BY 12Z MON
EXPECT SNOW ACCUMULATION TO BE LESS THAN AN INCH FOR THE FAR WEST BY
12Z MONDAY. THERE IS POTENTIAL FOR FOG TO BE AN ISSUE WITH RAIN OVER
THE SNOWPACK SO THIS WILL BE SOMETHING TO WATCH LATER TODAY. TEMPS WILL
RANGE FM THE LOWER 30S WEST TO UPPER 30S EAST.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 303 PM EST SUN NOV 23 2014
AT 00Z TUE...A SHORTWAVE WILL BE E OF THE CWA WITH THE ASSOCIATED
SFC LOW NEAR JAMES BAY. A WEAKENING UPPER TROUGH WILL BE OVER THE
FAR WRN CWA...WITH A RIDGE NW OF THE TROUGH. THE 12Z/23 NAM HAS COME
INTO BETTER AGREEMENT WITH 12Z/23 GFS AND 00Z/23 ECMWF IN SHOWING
LESS PHASING BETWEEN THE TWO FEATURES...AND THEREFORE HAVING MOST
/BUT NOT ALL/ OF THE SYNOPTIC SNOW NE OF THE CWA BY 00Z TUE. PRECIP
WILL BE ALL SNOW BY 00Z TUE AS 850MB TEMPS WILL FALL TO AOB -12C BY
12Z. WITH THE COLD AIRMASS...LAKE ENHANCEMENT WILL OCCUR IN NNW WIND
SNOWBELTS ALONG AND AHEAD OF THE TROUGH THAT WILL MOVE THROUGH THE
CWA BY 18Z TUE. BEHIND THE TROUGH...WINDS BECOME INCREASINGLY
ANTICYCLONIC...AND LOW LEVEL AIRMASS DRIER...AS THE RIDGE MOVES IN.
WILL CERTAINLY SEE DIMINISHING PRECIP COVERAGE/INTENSITY LATER TUE
INTO TUE NIGHT...BUT LES WILL NOT COMPLETELY END AS LOW LEVEL WINDS
FOCUS LES MORE OVER THE KEWEENAW PENINSULA. WNW WIND SNOWBELTS OF
THE NRN HURON MOUNTAINS AND OVER ALGER COUNTY WILL BE FAVORED FOR
THE GREATEST SNOWFALL AMOUNTS...WITH EXPECTATIONS OF 6-8 INCHES OF
SNOW MON NIGHT AND TUE IN THESE FAVORED LOCATIONS. ELSEWHERE NEAR
LAKE SUPERIOR AROUND 4 INCHES IS EXPECTED MON NIGHT/TUE...WITH LESS
AMOUNTS OF 1-3 INCHES INLAND. AFTER COORDINATION WITH SHORT TERM
SHIFT...LAKE EFFECT SNOW ADVISORIES HAVE BEEN ISSUED FOR ALL
COUNTIES ALONG LAKE SUPERIOR. AT LEAST FOR MON NIGHT/TUE...SNOW TO
LIQUID RATIOS SHOULD BE HIGH ENOUGH FOR THE LAKE EFFECT HEADLINE
INSTEAD OF WINTER WEATHER ADVISORIES. ALSO...BLOWING SNOW WILL OCCUR
ALONG LAKE SUPERIOR.
CONFIDENCE DECREASES SIGNIFICANTLY FOR WED THROUGH NEXT WEEKEND. FOR
WED INTO THU...MODELS AGREE IN SHOWING TWO SHORTWAVES MOVING INTO
THE CENTRAL CENTRAL U.S. WED...BUT DISAGREE ON THE
STRENGTH/TRACK/PHASING OF THE TWO WAVES...WHICH LEADS TO A WIDE
VARIETY OF SOLUTIONS FOR THE CWA. THE ECMWF PHASES THE WAVES OVER
THE REGION...WHICH LEADS TO A 1003MB SFC LOW MOVING FROM NEAR MPX AT
12Z WED TO LAKE HURON AT 12Z THU. THIS SOLUTION WOULD RESULT IN
SIGNIFICANT SNOWFALL AMOUNTS ACROSS THE CWA WED INTO THU. THE GFS
KEEP THE WAVES OUT OF PHASE AND THE SRN MOST WAVE MUCH FARTHER
S...LEAVING JUST A LITTLE LAKE ENHANCEMENT WED INTO WED NIGHT AS THE
NRN SHORTWAVE CROSSES THE AREA. OTHER MODELS HAVE VARYING SOLUTIONS
BETWEEN THESE TWO EXTREMES. NOT REALLY ABLE TO PICK BETWEEN THE
MODELS GIVEN THE NORMAL LOW CONFIDENCE WITH SHORTWAVE ENERGY AND
GENERALLY GOOD RUN TO RUN CONTINUITY OF THE GFS AND ECMWF WITH THIS
SYSTEM.
REGARDLESS OF SOLUTION...SHOULD SEE LES THU INTO THU NIGHT IN NW
WIND SNOWBELTS UNDER -18C TO -20C 850MB TEMPS. HOWEVER...THE GFS
THEN BRINGS WINDS OUT OF THE SW THU NIGHT AHEAD OF A STRONG CLIPPER
SYSTEM IT SHOWS MOVING INTO THE NRN PLAINS THU NIGHT AND ACROSS THE
CWA FRI NIGHT. ALL THE WHILE...THE ECMWF SHOWS A STRONG SFC HIGH
MOVING FROM THE NRN PLAINS TO THE MID MISSISSIPPI VALLEY. THE ECMWF
WOULD KEEP LES GOING IN NW-WNW SNOWBELTS THROUGH FRI...WHILE THE GFS
SOLUTION WOULD OBVIOUSLY NOT GIVEN THE CHANGE IN WINDS WITH THE SFC
LOW MOVING ACROSS THE CWA AND 850MB TEMPS INCREASE TO AROUND
0C...BUT DOES BRING LES BACK ON SAT BEHIND THE CLIPPER. MODELS DO
SHOW SOME AGREEMENT IN LOW LEVEL WINDS BECOMING FROM THE WSW BY SUN
WITH CONTINUED /BUT LIGHTER/ LES. WILL STICK CLOSER TO THE PREVIOUS
FORECAST GIVEN THE HIGH UNCERTAINTY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1258 PM EST SUN NOV 23 2014
WITH LOW LEVEL MOIST/WARM ADVECTION CONTINUING INTO THE AREA
SHOULD...PERSISTENT LOW CIGS AND FOG WILL CONTINUE INTO TONIGHT.
VLIFR CONDITIONS BELOW LANDING MINS ARE LIKELY TO PERSIST THIS
AFTERNOON AT KSAW WITH THE UPSLOPE FLOW HELPING TO MAINTAIN THE
DENSE FOG. SOME IMPROVEMENT MAY BE POSSIBLE WHEN RAIN MOVES IN THIS
EVENING AND OVERNIGHT. CONFIDENCE IN TIMING WHEN THE FOG MAY DIMINISH
IS UNCERTAIN. OTHERWISE...IFR/LIFR CIGS WILL ALSO PERSIST AT IWD AND
CMX BUT SHOULD NOT BE AS LOW WITH A MORE DOWNSLOPE SRLY WIND
COMPONENT. AS A DEEP LOW PRESSURE SYSTEM MOVES EAST OF THE AREA
MONDAY MORNING WINDS WILL BECOME NORTH AND QUICKLY STRENGTHEN WITH
ANY RAIN CHANGING TO SNOW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 523 AM EST SUN NOV 23 2014
SOUTH WINDS WILL INCREASE ON SUNDAY...ESPECIALLY OVER EASTERN
SECTIONS...BUT SHOULD REMAIN 30 KTS OR LESS. WINDS WILL BE VARIABLE
SUNDAY NIGHT AS TROUGH CROSSES LAKE SUPERIOR. A DEEPENING LOW WILL
MOVE TO EAST OF LAKE SUPERIOR ON MONDAY. NORTHERLY WINDS WILL
INCREASE TO GALES 40-45 KTS BY MONDAY MORNING INTO MONDAY NIGHT.
EXPECT WINDS TO DIMINISH TO 25 KTS OR LESS TUESDAY INTO
WEDNESDAY...THEN INCREASE TO 30 KTS ON THURSDAY AS COLD AIR POURS
ACROSS LAKE SUPERIOR BETWEEN HIGH PRESSURE BUILDING OVER THE
NORTHERN PLAINS AND LOW PRESSURE CROSSING THE LOWER GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY FROM 4 PM MONDAY TO 4 PM EST TUESDAY
FOR MIZ006-007-085.
DENSE FOG ADVISORY UNTIL 7 PM EST /6 PM CST/ THIS EVENING FOR
MIZ004>007-010>014-085.
LAKE EFFECT SNOW ADVISORY FROM 7 AM EST /6 AM CST/ MONDAY TO 7
AM EST /6 AM CST/ TUESDAY FOR MIZ001>003-009.
LAKESHORE FLOOD ADVISORY FROM 11 AM MONDAY TO 6 AM EST TUESDAY
FOR MIZ001-003-005>007.
LAKE EFFECT SNOW ADVISORY FROM 1 PM MONDAY TO 1 PM EST TUESDAY
FOR MIZ004-005.
LAKE SUPERIOR...
GALE WARNING FROM 3 PM MONDAY TO 4 AM EST TUESDAY FOR LSZ251-267.
GALE WARNING FROM 10 AM MONDAY TO 4 AM EST TUESDAY FOR
LSZ246>250-265-266.
GALE WARNING FROM 6 AM MONDAY TO 2 AM EST TUESDAY FOR LSZ242>245-
263-264.
GALE WARNING FROM NOON EST /11 AM CST/ TO 9 PM EST /8 PM CST/
MONDAY FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...TITUS
AVIATION...JLB
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1259 PM EST SUN NOV 23 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 523 AM EST SUN NOV 23 2014
MAIN FORECAST CONCERNS INCLUDE DENSE FOG THIS MORNING...TIMING THE
ONSET OF PCPN LATER TODAY AND THEN THE CHANGEOVER TO SNOW LATE
TONIGHT IN THE WEST.
WV IMAGERY AND RUC ANALYSIS SHOWS A VIGOROUS SRN STREAM SHORTWAVE
OFF THE TX GULF COAST WITH A STRONG SHORTWAVE AND ASSOC 150+ KNOT
250 MB JET MOVING OFF THE PAC NW INTO NRN NEVADA. ANOTHER SHORTWAVE
TROUGH WAS MOVING INTO WRN ND. AT THE SFC...SRLY FLOW PREVAILED FROM
THE GULF TOWARD THE UPPER MS VALLEY AND NRN GREAT LAKES REGION BTWN
HIGH PRES OVER THE MID ATLANTIC AND A 993 MB LOW OVER ND. WAA AND
LOW CLOUD COVER HAVE MAINTAINED TEMPS IN THE MID AND UPPER 30S
ACROSS UPPER MI EARLY THIS MORNING. THE WARM AIR MOVING OVER THE
MOSTLY SNOWPACKED GROUND HAS ALSO RESULTED IN DENSE FOG ACROSS MUCH
OF THE ERN TWO THIRDS OF UPPER MI THIS MORNING.
TODAY...EXPECT PCPN CHANCES TO GRADUALLY INCREASE THROUGH THE DAY AS
STRONG MOISTURE ADVECTION/TRANSPORT CONTINUES AND 850-700 MB FGEN
INCREASES. EXPECT THE BETTER CHANCE FOR RAIN OVER THE SOUTH CENTRAL
AND EAST IN PROXIMITY TO THE STRONGER DYNAMICS AND BEST MOISTURE. AS
THE MID-LVL DRY LAYER MOISTENS UP ANY DRIZZLE SHOULD CHANGE OVER TO
RAIN BY MID TO LATE AFTERNOON. EXPECT TEMPS WILL CLIMB ABOVE NORMAL
INTO THE LOW TO MID 40S. WARM AIR MOVING OVER THE COLD SNOW PACK HAS
RESULTED IN DENSE FOG THIS MORNING SO HAVE POSTED A DENSE FOG
ADVISORY THROUGH 16Z FOR ALL BUT THE FAR FOUR WESTERN COUNTIES OF
THE CWA.
TONIGHT...CONTINUED INCREASE IN DEEP LAYER Q-VECT
CONVERGENCE...DEVELOPMENT OF COUPLED UPPER JET STRUCTURE AND
ENHANCED 850-700 MB FGEN WILL LEAD TO WIDESPREAD RAINFALL ACROSS
MUCH OF THE CWA BY EVENING. MODEL AVERAGED QPF RANGES FROM .25 WEST
TO .75 SOUTHEAST. MODEL SNDGS AND CRITICAL 1000-850 MB THICKNESSES
SUGGEST RAIN WILL BEGIN TO SWITCH OVER TO SNOW FAR WEST AROUND 09Z
BUT WITH SNOW/WATER RATIOS RISING TO ONLY AROUND 6-7/1 BY 12Z MON
EXPECT SNOW ACCUMULATION TO BE LESS THAN AN INCH FOR THE FAR WEST BY
12Z MONDAY. THERE IS POTENTIAL FOR FOG TO BE AN ISSUE WITH RAIN OVER
THE SNOWPACK SO THIS WILL BE SOMETHING TO WATCH LATER TODAY. TEMPS WILL
RANGE FM THE LOWER 30S WEST TO UPPER 30S EAST.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 558 AM EST SUN NOV 23 2014
COMPLEX DEEPENING LOW PRESSURE SYSTEM AND ASSOCIATED SNOW/BLSN
MONDAY AND MONDAY NIGHT IS MAIN ISSUE.
WV LOOP AND 00Z RAOBS SHOW SPLIT FLOW OVER THE CONUS. STRONG
SHORTWAVE NOTED IN NORTHERN STREAM IS CROSSING SASKATCHEWAN WITH
VIGOROUS PAIR OF SHORTWAVES IN THE SOUTHERN STREAM OVER THE SOUTHERN
PLAINS AND INTO EAST TX. AT DAYBREAK ON MONDAY...SHORTWAVE CURRENTLY
OVER KS WILL BE LIFTING TOWARD UPPER GREAT LAKES. ASSOCIATED SFC LOW
WILL BE IN PROCESS OF DEEPENING TO AROUND 980MB VCTY OF NORTHERN
LOWER MICHIGAN OR EASTERN UPR MICHIGAN. WIDESPREAD PRECIPITATION
SHOULD BE ONGOING DUE TO LIFT FM H7-H5 Q-VECTOR CONVERGENCE FM LEAD
SHORTWAVE...RIGHT ENTRANCE FORCING FM JET STREAK OVER NORTHERN
ONTARIO...AND H85-H7 MOISTURE ADVECTION WRAPPING AHEAD OF SFC-H85
LOW. SOUNDINGS SHOW COOLING BLO 900MB LEADING TO INITIAL CHANGEOVER
FROM RAIN TO SNOW OVER WESTERN THIRD OF CWA. EXPECTED RAIN/SNOW LINE
FOLLOWS 925MB TEMP OF 0C PRETTY WELL.
SNOW AMOUNTS ON MONDAY DEPEND ON EXTENT OF MOISTURE INGESTED INTO
THE SFC LOW...AND MORE SPECIFICALLY HOW MUCH OF THIS DEEP MOISTURE
IS ADVECTED FARTHER TO THE WEST OF THE SFC LOW BACK INTO THE COLD
AIR. AT THIS TIME...ONLY MODEL THAT IS REALLY EMPHATIC WITH STRONGER
AND SLOWER SFC LOW AND THUS MORE DEEP MOISTURE TO WORK WITH IS THE
00Z/06Z NAM. OTHER MODELS AND ENSEMBLES...INCLUDING THE 00Z GFS AND
ECMWF AND 21Z SREF...AND TO A LESSER DEGREE THE 00Z GEM...ARE MORE
PROGRESSIVE WITH THE LOW AND ULTIMATELY HAVE LESS DEEPER MOISTURE
AND SYNOPTIC QPF LINGERING INTO MONDAY AFTN. USING MORE MIDDLE OF
ROAD APPROACH AS DO NOT HAVE ENOUGH CONFIDENCE TO TREND TOWARD
WETTER NAM IDEA. LESSER QPF ALONG WITH SNOW-LIQUID RATIOS THAT
BARELY RISE ABOVE 10:1 MOST OF MONDAY...RESULTED IN SOLID ADVISORY
LEVEL SNOWS OF 2-4 INCHES OR MAYBE 3-5 INCHES...HEAVIEST OVER FAR
WESTERN CWA WHERE PTYPE IS SNOW FOR LONGEST DURATION. LESS THAN 1
INCH OF SNOW DURING THE DAYTIME FOR EAST WITH A LATER CHANGEOVER.
GOING WITH PREFERRED GFS/ECMWF IDEA FOR MONDAY NIGHT...SHORTWAVE
MOVING NORTHEAST OVER THE WESTERN GREAT LAKES IS CAUGHT UP SOME BY
ANOTHER SHORTWAVE LEFT OVER THE CURRENT TROUGH OVER SASKATCHEWAN.
SWATH OF MODERATE SNOW SHOULD RESULT...MAINLY OVER NORTH AND EAST
CWA. ENOUGH COLD AIR WORKING IN BY THAT TIME TO LEAD TO LAKE
ENHANCEMENT OFF LK SUPERIOR. SIGNAL STILL THERE THAT SECONDARY AREA
OF SYNOPTIC FORCING/LIFT LINKS UP WITH MOST IDEAL LAKE ENHANCEMENT
VCNTY OF NNW WIND SNOW BELTS OF ALGER/NORTHERN SCHOOLCRAFT COUNTIES.
LATEST 12 HR SNOW AMOUNTS ARE PUSHING WARNING CRITERIA OF 6 INCHES
FOR THESE AREAS. MODERATE SNOW ACCUMULATIONS WILL CONTINUE ALONG
MUCH OF LK SUPERIOR...BUT SNOW AMOUNTS SHOULD BE ON THE DECLINE
ALONG THE WI BORDER AS BETTER FORCING MISSES THAT AREA TO THE EAST.
FROM AT STRICTLY SNOW AMOUNT CRITERIA...EVENT LOOKS TO BE SOLID ADVY
MONDAY INTO MONDAY NIGHT. SNOW ON TUESDAY SHOULD BE ON THE WANE AS
EVEN THOUGH IT IS BECOMING COLDER FOR LAKE EFFECT...SUPPLEMENTAL
LARGER SCALE FORCING IS ON THE WANE. SOUNDINGS INDICATE LESSENING
CYCLONIC FLOW WILL REALLY PUT THE KABOSH ON LINGERING LAKE EFFECT ON
TUESDAY. ONE ASPECT OF THE SYSTEM THAT CANNOT BE DISCOUNTED THOUGH
IS THE WIND. SFC LOW DEEPENS AS IT LIFTS EAST OF LK SUPERIOR AND ON
TO THE NORTHEAST ON MONDAY NIGHT TRACKING TOWARD JAMES BAY. AT THE
PEAK...PRESSURE GRADIENT WEST TO EAST FROM DLH TO SSM IS 20 MB LATE
MONDAY AFTN INTO MONDAY EVENING. SOUNDINGS INDICATE 35+ KT WINDS
ABOVE H9 WITH 40+ KTS ABOVE H8. GIVEN THE DEGREE OF MIXING WITH THE
COLD AIR ADVECTION EXPECTED...SEEMS REASONABLE THAT MOST AREAS WILL
SEE GUSTS 30-40 MPH. BLOWING SNOW/POOR VSBY MAY BECOME PRETTY BIG
FACTOR OVER MUCH OF THE AREA WITH THE STRONG WINDS.
SINCE THIS EVENT SEEMS TO BE HEADING TOWARD MORE OF AN ADVY EVENT
INSTEAD OF A WARNING...DECIDED TO NOT ISSUE A WATCH AND INSTEAD
ISSUE ANOTHER SPECIAL WEATHER STATEMENT. DID EXPAND THE SPS TO
INCLUDE ALL OF THE CWA WITH THE POTENTIAL FOR MODERATE SNOW AND BLSN
OVER MUCH OF THE AREA.
REST OF THE WEEK COULD FEATURE HIGHER IMPACT WEATHER FOR THE TRAVEL
TIME AROUND THANKSGIVING AND THE HOLIDAY ITSELF. DETAILS FAR FROM
CERTAIN BUT AFTER A LULL FOR MOST AREAS ON TUESDAY NIGHT /MINS
POSSIBLY NEAR 0F OVER INTERIOR CNTRL CWA WITH ENOUGH CLEARING TUE
NIGHT/...ANOTHER PAIR OF SHORTWAVES ARE FORECAST TO SLIDE SOUTHEAST
OVER THE GREAT LAKES WEDNESDAY INTO WEDNESDAY NIGHT. GFS WEAKER THAN
THE ECMWF WITH THE SFC TROUGH AND THAT AFFECTS THE DEGREE OF
CYCLONIC FLOW AND LAKE ENHANCED SNOW THAT DEVELOPS AS THE SYSTEM
MOVES BY. ALSO COULD SEE MORE STRONG WINDS DUE TO TIGHTER PRESSURE
GRADIENT...ESPECIALLY NEAR LK SUPERIOR OVER THE WEST. HAVE LIKELY
POPS ALONG MOST OF THE NORTHERN PART OF CWA LATER WEDNESDAY INTO
WEDNESDAY NIGHT AND ALSO FOR THANKSGIVING NEAR LK SUPERIOR FOR
NNW-NW FLOW LAKE EFFECT. OVER-WATER INSTABILITY NON-ISSUE AS H85
TEMPS FALL BLO -15C WED NIGHT AND TREND TOWARD -20C ON THANKSGIVING.
TEMPS WILL STRUGGLE THROUGH THE TEENS ON THANKSGIVING MAKING IT MORE
LIKE LATE DECEMBER OR JANUARY. RECORD LOW MAX AT NWS MQT FOR 27
NOVEMBER IS 18 SET IN 1967. COULD BE CLOSE TO THAT MARK.
COLD AIRMASS WILL KEEP LAKE EFFECT GOING TO CLOSE THE WEEK...MAINLY
FOR WNW-WSW FLOW REGIMES...SO MOSTLY LOOKING AT KEWEENAW AND ALONG
LK SUPERIOR TO EAST OF MARQUETTE. IF THERE IS ANY MODERATION IN
TEMPS IT PROBABLY WILL NOT BE UNTIL LATE IN THE WEEKEND OR EVEN
EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1258 PM EST SUN NOV 23 2014
WITH LOW LEVEL MOIST/WARM ADVECTION CONTINUING INTO THE AREA
SHOULD...PERSISTENT LOW CIGS AND FOG WILL CONTINUE INTO TONIGHT.
VLIFR CONDITIONS BELOW LANDING MINS ARE LIKELY TO PERSIST THIS
AFTERNOON AT KSAW WITH THE UPSLOPE FLOW HELPING TO MAINTAIN THE
DENSE FOG. SOME IMPROVEMENT MAY BE POSSIBLE WHEN RAIN MOVES IN THIS
EVENING AND OVERNIGHT. CONFIDENCE IN TIMING WHEN THE FOG MAY DIMINISH
IS UNCERTAIN. OTHERWISE...IFR/LIFR CIGS WILL ALSO PERSIST AT IWD AND
CMX BUT SHOULD NOT BE AS LOW WITH A MORE DOWNSLOPE SRLY WIND
COMPONENT. AS A DEEP LOW PRESSURE SYSTEM MOVES EAST OF THE AREA
MONDAY MORNING WINDS WILL BECOME NORTH AND QUICKLY STRENGTHEN WITH
ANY RAIN CHANGING TO SNOW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 523 AM EST SUN NOV 23 2014
SOUTH WINDS WILL INCREASE ON SUNDAY...ESPECIALLY OVER EASTERN
SECTIONS...BUT SHOULD REMAIN 30 KTS OR LESS. WINDS WILL BE VARIABLE
SUNDAY NIGHT AS TROUGH CROSSES LAKE SUPERIOR. A DEEPENING LOW WILL
MOVE TO EAST OF LAKE SUPERIOR ON MONDAY. NORTHERLY WINDS WILL
INCREASE TO GALES 40-45 KTS BY MONDAY MORNING INTO MONDAY NIGHT.
EXPECT WINDS TO DIMINISH TO 25 KTS OR LESS TUESDAY INTO
WEDNESDAY...THEN INCREASE TO 30 KTS ON THURSDAY AS COLD AIR POURS
ACROSS LAKE SUPERIOR BETWEEN HIGH PRESSURE BUILDING OVER THE
NORTHERN PLAINS AND LOW PRESSURE CROSSING THE LOWER GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
DENSE FOG ADVISORY UNTIL 2 PM EST /1 PM CST/ THIS AFTERNOON FOR
MIZ004>007-010>014-085.
LAKESHORE FLOOD ADVISORY FROM 11 AM MONDAY TO 6 AM EST TUESDAY
FOR MIZ001-003-005>007.
LAKE SUPERIOR...
GALE WARNING FROM 3 PM MONDAY TO 4 AM EST TUESDAY FOR LSZ251-267.
GALE WARNING FROM 10 AM MONDAY TO 4 AM EST TUESDAY FOR
LSZ246>250-265-266.
GALE WARNING FROM 6 AM MONDAY TO 2 AM EST TUESDAY FOR LSZ242>245-
263-264.
GALE WARNING FROM NOON EST /11 AM CST/ TO 9 PM EST /8 PM CST/
MONDAY FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...JLA
AVIATION...JLB
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1145 AM CST SUN NOV 23 2014
.UPDATE...
ISSUED AT 1132 AM CST SUN NOV 23 2014
JUST EXTENDED THE DENSE FOG ADVY FOR AREAS EAST OF I-35 THROUGH
00Z. AT THE MOMENT...A COLD FRONT EXTENDS MORE OR LESS DOWN
I-35...FOG EAST OF IT AND MUCH IMPROVED CONDITIONS AND A BAND OF
DEFORMATION RAIN TO THE WEST. A QUICK TOURS OF WEBCAMS ACROSS THE
CITIES SHOWS QUITE THE IMPRESSIVE GRADIENT IN CONDITIONS...WITH
494 GOING FROM 1/4SM VISIBILITY AT MN-5 TO JUST HAZY CONDITIONS AT
MN-77 ALONG I-94 WE ARE SEEING THE SAME THING...WITH GOOD
VISIBILITIES IN MINNEAPOLIS...BUT DENSE FOG IN ST. PAUL...WITH
MN-280 ACTING AS THE DELINEATION LINE AT THIS POINT.
WITH THE HRRR SHOWING LOW VISBYS REMAINING ACROSS WRN WI THROUGH
AT LEAST 00Z...DECIDED TO EXTEND THE ADVY THROUGH THEN. WE WILL
REASSESS THE ADVY LATER THIS AFTERNOON TO PROBABLY KNOCK OF A FEW
OF THE COUNTIES ON THE WEST SIDE AND DECIDE IF WE NEED TO GO ANY
LONGER INTO THE NIGHT OF THE FAR ERN MPX CWA COUNTIES.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 400 AM CST SUN NOV 23 2014
THE SURFACE TROUGH NOSING INTO THE FORECAST AREA WILL CONTINUE TO
FOSTER AREAS OF DENSE FOG FOR AREAS GENERALLY NORTH OF INTERSTATE
94 THIS MORNING NORTH OF THE WARM FRONT THAT/S BISECTING THE
FORECAST AREA. HAVE EXTENDED THE DENSE FOG ADVISORY THROUGH THE
MORNING HOURS...WITH LITTLE IMPROVEMENT IN VISIBILITY EXPECTED
UNTIL THEN.
THE AFOREMENTIONED WARM FRONT WILL CONTINUE TO LIFT NORTH ACROSS
THE AREA TODAY...WITH ONGOING LIGHT PRECIPITATION POSSIBLE THROUGH
THE DAY. THE GOOD NEWS IS THAT TEMPERATURES HAVE CLIMBED ABOVE THE
FREEZING MARK ACROSS THE ENTIRE FORECAST AREA...THEREFORE
MINIMIZING THE CONCERN FOR FREEZING PRECIPITATION DURING THE
DAYTIME HOURS.
THIS EVENING...AS COLDER AIR INFILTRATES THE AIR IN RELATION TO THE
PASSING COLD FRONT...SHOULD SEE THE PRECIPITATION TYPE TRANSITION
TO ALL SNOW. WINDS BEHIND THE FRONT WILL BE SIGNIFICANT...WITH
SUSTAINED SPEEDS ACROSS WEST CENTRAL MN BETWEEN 25 MPH AND 30 MPH
WITH GUSTS TO AROUND 30 MPH. BLOWING SNOW CONCERNS HAVE DIMINISHED
A BIT GIVEN THE AFFECTS THE ANTECEDENT PRECIP AND SNOWMELT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 400 AM CST SUN NOV 23 2014
ONLY A FEW MINOR CHGS IN THE EXTENDED PERIOD WITH THE COLD THAN
NORMAL CONDS CONTINUING WITH SMALL CHC/S OF SNOW.
OVERALL...THE MEAN UPPER FLOW REMAINS FROM THE N/NW THIS WEEK.
THE 5-DAY 50H MEAN /GFS/GEM/EC/ IS CONSISTENT WITH THE UPPER LOW
PARKED NORTH OF HUDSON BAY THRU THIS WEEK. THE BIGGEST CHG IS
ASSOCIATED WITH THE BREAK DOWN OF THE UPPER RIDGE ACROSS THE
WEST...WHICH MAY LEAD TO A MORE PROGRESSIVE/ZONAL FLOW BY THE WEEK
OF DECEMBER 1ST. TEMPS WILL BE COLDEST MONDAY THRU THURSDAY...WITH
SOME MODIFICATIONS NEXT WEEKEND.
MONDAY WILL BE WINDY WITH SOME PATCHY BLOWING SNOW WHERE WINDS GUSTS
IN THE 30 TO 40 MPH RANGE. HOWEVER...SNOWFALL WILL BE LIMITED IN THE
TYPICAL AREAS OF WC/SW/SC MN MONDAY WITH ONLY A LIGHT DUSTING
EXPECTED. PLUS WARM TEMPS OVER THE PAST 24 TO 36 HRS HAS ALLOWED A
CREST TO FORM ON THE SNOW COVER...LIMITING BLOWING SNOW POTENTIAL.
FOR PRECIPITATION RELATED CHGS NEXT WEEK...A FAST MOVING SHRTWV AND
ASSOCIATED SFC LOW WILL MOVE ACROSS THE PLAINS/MIDWEST WED. THERE
REMAINS A FAIRLY STRONG JET STREAK WITH THIS SYSTEM...LEADING TO AN
ENHANCED AREA OF LARGE SCALE LIFT IN THE EXIT REGION OF THIS JET IN
THE UPPER MIDWEST. MOISTURE LEVELS REMAIN LIMITED...SO HEAVIER
SNOWFALL AMTS WILL BE BASED ON THE LOCATION OF THE SFC LOW AND MID
LEVEL FRONTOGENESIS. HAVE INCREASED TO 50% FOR WEDNESDAY BASED ON
THE STRONGER JET STREAK AND SFC LOW LOCATION.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 700 AM CST SUN NOV 23 2014
MVFR CIGS/VSBYS WILL PERSIST THIS MORNING AS A WARM FRONT LIFTS
ACROSS THE AREA. THE WORST CONDITIONS /AND LOWEST CIGS AND VSYS/
WILL OCCUR NORTH OF THE TAF SITES...BUT AN IMPROVEMENT SHOULD BE
SEEN THIS AFTERNOON AT THE MN SITES. A COLD FRONT WORKS ACROSS THE
AREA THIS EVE...WITH GUSTY NORTHWEST WINDS DEVELOPING IN ITS WAKE.
REAS OF DRIZZLE/RAIN OVER WI SITES/PRIMARILY KEAU/ WILL TRANSITION
TO SNOW AFTER SUNSET...WITH KMSP ON THE WESTERN EDGE OF THE SNOW/PRECIP.
KMSP...
VSBYS SHOULD REMAIN AROUND 5-6SM WITH AREAS OF FOG THROUGH THE
MORNING. TOUGH CALL ON THE TIMING FOR VFR CIGS...IF ANYTHING
EXPECT THE TAF IS TOO OPTIMISTIC IN GOING TO VFR BY 14Z. FROPA
OCCURS THIS AFTERNOON WITH WINDS SHIFTING TO THE NORTHWEST AROUND
21Z...AND GUSTS INTO THE MID/UPPER 20S DEVELOPING THIS EVE AND
PERSISTING INTO SUNDAY...WITH SUB-1800 FT CIGS RETURING.
/OUTLOOK FOR KMSP/
MON...MVFR/IFR CIGS CHC -SN. WINDS NW 20G30 KT.
TUE...VFR. WINDS W 5-10 KT.
WED...MVFR/IFR CHC -SN. WINDS NW 10KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...DENSE FOG ADVISORY UNTIL 6 PM CST THIS EVENING FOR MNZ053-
061>063.
WI...DENSE FOG ADVISORY UNTIL 6 PM CST THIS EVENING FOR WIZ014>016-
023-025-027-028.
&&
$$
UPDATE...MPG
SHORT TERM...LS
LONG TERM...JLT
AVIATION...LS
AREA FORECAST DISCUSSION...UPDATED
NWS WILMINGTON NC
447 PM EST SUN NOV 23 2014
.SYNOPSIS...
MILD AND UNSETTLED WEATHER CAN BE EXPECTED OVERNIGHT INTO MONDAY
AS A STORM SYSTEM RISES OUT OF THE GULF OF MEXICO. ISOLATED SEVERE
THUNDERSTORMS REMAIN POSSIBLE OVERNIGHT AND ON MONDAY. A COLD
FRONT WILL CROSS THE COAST AND STALL OFFSHORE TUESDAY. COOL AND
WET CONDITIONS ARE EXPECTED WEDNESDAY...AS DEEPENING LOW PRESSURE
MOVES NORTH ALONG THE STALLED FRONT AND SKIRTS THE COAST. SKIES
WILL BEGIN A CLEARING TREND ON THANKSGIVING...WITH TEMPERATURES
RUNNING SEVERAL DEGREES BELOW NORMAL THURSDAY INTO NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF 4 PM SUNDAY...WARM ADVECTION ZONE ALOFT HAS LIFTED TO OUR
NORTH EVEN AS SURFACE BOUNDARY LAGS WELL TO OUR SOUTH. AS A RESULT
THE ISENTROPIC UP-GLIDE ACROSS THE REGION APPEARS TO HAVE WEAKENED TO
THE POINT THAT RAINFALL MAY BE QUITE LIGHT FOR THE NEXT SEVERAL
HOURS. LOOKING FOR RADAR TO FILL LATER ON FROM SW TO NE AS ENERGY
FROM THE WEAKENING VORT NOW SEEN OVER MS IMPINGES UPON THE REGION.
IN THE MEANTIME TOUGH TO SAY HOW MUCH RAIN THE AREA SEES AND MODEL
GUIDANCE IS QUITE OVERDONE. THE UPPER WAVE WILL BE WEAKENING AND
THUS ACCELERATING...LOOKS LIKE ANY TIME SOON AFTER 03Z IT MAY START
AFFECTING THE REGION. LOW LEVEL WIND FIELDS CURRENTLY IN THE PROCESS
OF STRENGTHENING DRAMATICALLY ALTHOUGH CHS AND KLTX VWPS SHOW THAT
THE WRF IS TOO FAST AND TOO STRONG. ACCORD TO THE MORE TEMPERED GFS
A SOLID 50KT AT JUST 925MB CAN BE EXPECTED ALONG THE COAST BY 00Z
AND AREA-WIDE BY 06Z. PAIR THIS WITH STEADY OR RISING TEMPERATURES
AND THERE IS STILL A WIDOW OF OPPORTUNITY FOR SHALLOW CONVECTION
TORNADOES INVOF OF THE WARM FRONT.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
AS OF 4 PM SUNDAY...ODDLY MILD CONDITIONS TO ENGULF THE EASTERN
CAROLINAS MONDAY WITH STRONG WARM AIR ADVECTION PATTERN IN PLACE
AND A COLD FRONT AND UPPER TROUGH WEST OF THE FORECAST AREA. 65-70
TEMPERATURE RANGE TO GREET MOST AREAS DAYBREAK MONDAY...AS MAXIMUM
TEMPERATURES CLIMB INTO THE MIDDLE AND UPPER 70S...LIKELY UNDER A
CANOPY OF CLOUDS DUE TO EXTENT OF UPSTREAM CONVECTION. THE LOW-LVL
WIND FIELD REMAINS STRONG MONDAY...AND ANY SURFACE HEATING MONDAY
AFTERNOON COULD LEAD TO CONVECTION CAPABLE OF DAMAGING WIND...AND
EVEN SHOWERS WILL BRING LOCALLY STRONGER GUSTS. SPC MAINTAIN A LOW
END RISK NEAR THE COAST AHEAD OF A COLD FRONT.
TUESDAY A POST-FRONTAL DAY WHERE WEATHER HAZARDS WANE. THE UPSTREAM
TROUGH ALIGN HOWEVER WILL SUPPORT MORE IMPULSES RISING OUT OF THE
GULF. CYCLOGENESIS OFFSHORE OF NORTHERN FLORIDA OCCUR VERY LATE IN
THE PERIOD AND BECOME A WEATHER PLAYER BEYOND DAYBREAK WEDNESDAY AND
POP VALUES DO GRADUALLY RAMP UP TO THIS FEATURE LATE TUESDAY.
RECORD HIGH TEMPS MONDAY ARE ILM 79...FLO 83...CRE 76...LBT 78.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 4 PM SUNDAY...MAIN FOCUS FOR THE PERIOD REMAINS LOW PRESSURE
PASSING JUST OFF THE COAST WED. SHORTWAVE CROSSING THE WESTERN GULF
LATE TUE WILL ENHANCE SURFACE WAVE JUST OFF THE FL GULF COAST WED
MORNING. THIS LOW WILL TRAVEL NORTHEAST ALONG A STALLED BOUNDARY WED
INTO WED NIGHT WITH DEEP MOISTURE SPREADING OVER THE CAROLINAS. LOW
WILL REMAIN EAST OF THE COASTAL WATERS WITH INCREASING NORTHERLY
FLOW...CLOUD COVER...AND PERIODS OF HEAVY RAIN KEEPING TEMPERATURES
IN THE 40S FOR MUCH OF THE AREA. PRESENCE OF DEEP MOISTURE AND
STRONG LIFT/DIVERGENCE ALOFT WILL ENSURE PLENTY OF RAIN FALLS ACROSS
THE AREA WED. MID LEVEL TROUGH MOVES INTO THE AREA WED EVENING WITH
SIGNIFICANT AMOUNT OF DRY AIR MOVING IN...ENDING THE RAIN THREAT.
SUBTLE MID LEVEL TROUGHING IN THE WAKE OF THE EXITING SYSTEM REMAINS
OVER THE SOUTHEAST FRI...PUSHING A DRY COLD FRONT ACROSS THE AREA.
MID LEVEL PATTERN FLATTENS OUT FOR THE WEEKEND AND FLOW ALOFT
BECOMES PROGRESSIVE. HIGH PRESSURE BUILDING IN FOR THE WEEKEND
QUICKLY SHIFTS OFFSHORE WITH RETURN FLOW DEVELOPING AND TEMPS
CLIMBING BACK CLOSE TO CLIMO.
&&
.AVIATION /22Z SUNDAY THROUGH FRIDAY/...
AS OF 18Z...LOOKING FOR TWO MAIN AREAS OF HEAVIER PRECIP...THE
FIRST BATCH WITH A SLUG OF GULF MOISTURE AND ISENTROPIC LIFT THIS
AFTERNOON...THE SECOND BATCH TONIGHT WITH A VIGOROUS VORT MAX.
TONIGHT WILL BE INTERESTING WITH VERY STRONG HELICITY BUT NO CAPE
TO SPEAK OF. NEVERTHELESS AN ISOLATED SEVERE STORM IS POSSIBLE
MAINLY NEAR THE COAST. VORT WILL ROTATE THROUGH THE REGION BY
06-07Z. MODELS REALLY BRING CEILINGS/VIS DOWN ONCE THE VORT MOVES
THROUGH...WITH PRECIP SLOWLY SHUTTING OFF. THE MODELS REALLY WANT
TO KEEP VISIBILITIES LIFR THROUGH MOST OF THE BACK IN PERIOD...BUT
WITH WINDS OVER 10 KTS...THINK THIS MAY BE OVERDONE. LOOK FOR
GUSTY SOUTHWEST WINDS MONDAY WITH CEILINGS REMAINING IFR THROUGH
MOST IF NOT ALL THE FORECAST PERIOD.
EXTENDED OUTLOOK...UNSETTLED WEATHER IS EXPECTED MONDAY AFTERNOON
THROUGH WEDNESDAY NEAR THE COAST...WITH OCCASIONAL SHOWERS AND
MVFR/IFR CONDITIONS. BECOMING VFR WEDNESDAY NIGHT...THROUGH FRIDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 445 PM SUNDAY...A NON-CONVECTIVE WIND GUST TO 45 KNOTS
WITHIN THE PAST HOUR AT THE FRYING PAN SHOALS BUOY CERTAINLY
GRABBED MY ATTENTION. A GALE WARNING HAS THEREFORE BEEN ISSUED FOR
THE NC WATERS...VALID NOW THROUGH MIDNIGHT. VIRTUALLY ALL SHORT-
RANGE GUIDANCE (LATEST RRR AND RUC PLUS THE 18Z NAM) BRING A SWATH
OF EVEN STRONGER WINDS IN THE 1000-950 MB LAYER ACROSS THE COASTAL
WATERS BETWEEN NOW AND MIDNIGHT. THE ONLY FACTOR DIMINISHING WIND
SPEEDS DOWN HERE AT THE SURFACE IS STRONG BOUNDARY LAYER STABILITY
INDUCED BY COLD OCEAN SURFACE TEMPERATURES AND SUBSEQUENT
INHIBITED VERTICAL MIXING OF STRONGER WINDS FROM ALOFT. WATER
TEMPERATURES ARE IN THE 50S SOUTHWEST OF CAPE FEAR ALONG THE UPPER
SOUTH CAROLINA COAST... AND THIS SHOULD PREVENT WINDS FROM
INCREASING ABOVE 30 KNOTS EVEN AT 20 MILES DISTANCE FROM SHORE.
PREVIOUS DISCUSSION FROM 400 PM FOLLOWS...
DRAMATIC INCREASE IN MARINE WINDS LAST THREE HOURS AS 41013 NOW A
SOLID 29KT WITH OCCASIONAL GUSTS TO GALE FORCE. AND WHILE A SHORT-
FUSED GALE WARNING MAY BE PREFERRED BY THE NEXT SHIFT CURRENTLY
HOPING THAT COOLER SHELF WATERS WILL RETARD MANY GALE FORCE GUSTS
FROM MIXING DOWN TO THE SURFACE DESPITE THE SCREAMING LOW LEVEL
JET ALL NIGHT. ADDITIONAL CONCERN AFTER COLLAB WITH CHS THAT BUOYS
MAY BE EXPERIENCING STRONGER WINDS AND GUSTS THAN NEAR SHORE
WATERS ON ACCOUNT OF THE HEAVIER PRECIP OUT THERE AND THUS DEEPER
MIXING. A STRONG ADVISORY STILL IN EFFECT THROUGH THE PERIOD AND
BEYOND.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 4 PM SUNDAY...MONDAY MARINE CONDITIONS REMAIN DANGEROUS WITH
SEAS OF 5-9 FEET LIKELY AND HIGHEST AWAY FROM SHORE AND NEAR THE
FRYING PAN SHOALS. 20-30 KT SSW WINDS MONDAY...BECOMING WEST LATE
TUESDAY NIGHT OR EARLY MONDAY AS A SURFACE COLD FRONT MOVES ACROSS
THE WATERS. STRONG TSTMS REMAIN POSSIBLE MONDAY THROUGH TUESDAY
MORNING ON THE 0-20 NM WATERS. LARGE SSW-SE WAVES WILL MAKE UP THE
SEA SPECTRUM IN MIXED WAVE PERIODS OF 5-6 SECONDS AND 8-9 SECONDS.
IMPROVING CONDITIONS TUESDAY ALTHOUGH WAVE RECOVERY WILL STILL BE
UNDERWAY EARLY TUESDAY.
LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 4 PM SUNDAY...PERIOD OF HEADLINES SEEMS LIKELY WED INTO
WED NIGHT AS DEEPENING LOW PRESSURE PASSES JUST EAST OF THE
WATERS. WINDS WILL BACK FROM NORTH-NORTHEAST TO WEST WED INTO WED
NIGHT AS THE LOW LIFTS NORTHEAST. SPEEDS WILL PEAK IN THE 20 TO 25
KT RANGE WITH SEAS NEAR 20 NM FLIRTING WITH 6 TO 7 FT. OFFSHORE
FLOW WEAKENS LATE WED NIGHT INTO THU AS SURFACE HIGH TO THE WEST
BUILDS EAST. SPEEDS REMAIN CLOSE TO 15 KT THU WITH A SLIGHT
INCREASE FRI AS DRY COLD FRONT PASSES AND BRIEF COLD ADVECTION
DEVELOPS. AN OFFSHORE COMPONENT WILL KEEP SEAS WITHIN 20 NM IN THE
2 TO 4 FT RANGE THU AND FRI.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST TUESDAY FOR AMZ254-256.
SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 6 AM EST TUESDAY
FOR AMZ250-252.
GALE WARNING UNTIL MIDNIGHT EST TONIGHT FOR AMZ250-252.
&&
$$
SYNOPSIS...MJC
NEAR TERM...TRA/MBB
SHORT TERM...MJC
LONG TERM...III
AVIATION...MBB/DL
AREA FORECAST DISCUSSION
NWS TULSA OK
243 PM CST SUN NOV 23 2014
.DISCUSSION...
STRONG SHORTWAVE TROUGH COMING IN FROM THE NORTHWEST THIS
AFTERNOON. THE SURFACE FRONT IS WORKING ITS WAY EAST ACROSS
OKLAHOMA...ROUGHLY NEAR THE I-35 CORRIDOR. SOLID BAND OF RAIN
SHOWERS HAS DEVELOPED BEHIND THE FRONT WHERE THE BETTER LOW-MID
LEVEL COLD FRONTOGENETIC FORCING LIES. THE LATEST HRRR ALSO
DEVELOPS SHOWERS AND SOME THUNDER ALONG AND AHEAD OF THE SURFACE
FRONT LATE THIS AFTERNOON AND INTO THE EVENING ACROSS FAR NE OK
AND NW AR. WILL MAINTAIN HIGHEST POPS NEAR THE KS AND MO BORDERS
FOR THIS EVENING. AFTER THIS WAVE PASSES BY...THE REMAINDER OF THE
FORECAST WILL BE DRY. THERE WILL BE A NARROW WINDOW THIS EVENING
WHERE NORTHWEST WINDS BEHIND THE FRONT MAY GET GUSTY ENOUGH TO
FLIRT WITH ADVISORY CRITERIA ACROSS NE OK. NEVERTHELESS...EXPECT A
BREEZY NIGHT AHEAD.
AFTER A WARM DAY TODAY...TEMPS WILL TAIL OFF TO START THE WEEK.
THE COOLEST MORNING WILL PROBABLY BE TUESDAY MORNING. WARMING
TREND THEN KICKS IN BY THE MIDDLE OF THE WEEK AND CONTINUES INTO
THE HOLIDAY WEEKEND. POOR MODEL RUN TO RUN CONSISTENCY CONTINUES
FOR THE HOLIDAY WEEKEND...ESPECIALLY WITH THE ECMWF. THIS MODEL
HAS STRUGGLED WITH THE DEGREE OF UPPER RIDGING ACROSS THE WESTERN
CONUS FOR DAYS AND DAYS...LEAVING OUR AREA WITH DRASTICALLY
DIFFERENT FORECASTS FROM DAY TO DAY. AFTER SUGGESTING A FRONT FOR
NEXT WEEKEND...IT HAS NOW FLOPPED BACK TO A WARM...LESS
AMPLIFIED...MORE PROGRESSIVE REGIME. THE GFS SHOWS A FRONT
DROPPING IN BY THE LATTER PART OF THE WEEKEND...BUT CONFIDENCE IS
LOW...SO STAYED WITH A BLEND OF SOLUTIONS TOWARD DAY 7 AND WILL
MAINTAIN DRY FORECAST. THE BOTTOM LINE IS THAT IT STILL APPEAR
THAT HOLIDAY TRAVEL WILL BE A GO...WHICH IS GOOD NEWS FOR MANY OF
US.
LACY
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 36 56 30 51 / 40 0 0 10
FSM 39 56 31 53 / 20 0 0 10
MLC 37 58 31 54 / 20 0 0 10
BVO 35 55 24 50 / 50 0 0 10
FYV 34 50 25 47 / 50 0 0 10
BYV 35 47 26 46 / 70 10 0 10
MKO 36 57 29 51 / 30 0 0 10
MIO 34 51 26 47 / 80 0 0 10
F10 37 57 31 52 / 30 0 0 10
HHW 39 60 33 58 / 10 10 10 10
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
LONG TERM....30
AREA FORECAST DISCUSSION
NWS MEDFORD OR
913 AM PST SUN NOV 23 2014
.DISCUSSION...CURRENT VISIBLE IMAGE SHOWS CLOUD COVER THINING OUT
OVER THE NORTHERN PART OF THE FORECAST AREA AND IS GRADUALLY
PUSHING SOUTH. MEANWHILE LOW CLOUDS AND PATCHY FOG WILL PERSIST IN
THE WESTSIDE VALLEYS FOR A FEW MORE HOURS THEN WILL BE REPLACED BY
HIGH CLOUDS. DID NOT SEE ANY EVIDENCE OF PRECIPITATION THIS
MORNING, SO REMOVED ANY MENTION OF PRECIP FOR THIS MORNING AND
AFTERNOON. NEXT WE`LL TAKE A CLOSER LOOK AT PRECIPITATION CHANCES
FOR MONDAY. THE 12Z NAM CONTINUES TO TREND WET. THE GFS HAS ALSO
TRENDED WETTER THE PAST COUPLE OF RUNS, SO CONFIDENCE IS HIGHER
WE`LL HAVE A HIGH POP, LOW QPF EVENT, ESPECIALLY WEST OF THE
CASCADES. -PETRUCELLI
&&
.AVIATION...BASED ON THE 23/12Z TAF CYCLE...VFR CIGS HAVE
DEVELOPED AT KOTH AND KRBG AND EXPECT VFR CONDITIONS TO CONTINUE
INTO THIS AFTERNOON, BUT MOUNTAINS WILL REMAIN PARTLY OBSCURED.
IFR/LIFR CIGS/FOG IN THE ROGUE, ILLINOIS AND WESTERN SISKYOU
COUNTY VALLEYS WILL CONTINUE FOR A FEW MORE HOURS. VFR CIGS WITH
PARTIAL MOUNTAIN OBSCURATIONS ARE EXPECTED THIS AFTERNOON INTO
THIS EVENING. OVERNIGHT, EXPECT AREAS OF VALLEY IFR CIGS IN
PATCHY FOG TO DEVELOP FOR AREAS WEST OF THE CASCADES.
&&
.MARINE...UPDATED 4AM PST SAT NOV 22 2014... STEEP WEST SWELL WILL
PERSIST TODAY INTO MONDAY, THEN SLOWLY DIMINISH MONDAY EVENING AND
TUESDAY. A WARM FRONT WILL LIFT NORTHWARD THROUGH THE WATERS SUNDAY
NIGHT AND MONDAY. WINDS ARE EXPECTED TO BE MAINLY LIGHT AND
SOUTHERLY AROUND 10 TO 20 KT ON MONDAY. ALTHOUGH AT LEAST ONE MODEL
SHOWS 25 KT SMALL CRAFT ADVISORY WINDS POSSIBLE MONDAY INTO MONDAY
EVENING. WEAK HIGH PRESSURE IS EXPECTED TUESDAY INTO WEDNESDAY.
THEN A COUPLE FRONTAL SYSTEMS WILL MOVE INTO THE WATERS WEDNESDAY
NIGHT THROUGH FRIDAY, BRINGING AN INCREASE IN SOUTH WINDS AND
SEAS.
&&
.PREV DISCUSSION... /ISSUED 420 AM PST SUN NOV 23 2014/
DISCUSSION...
SEVERAL SNOTELS NORTH OF HIGHWAY 140 FROM FOURMILE LAKE NORTH TO
SUMMIT LAKE RELIABLY INDICATE BETWEEN 3 AND 6 INCHES OF NEW SNOW
ACCUMULATED IN THE LAST 24 HOURS BETWEEN 5000 FOOT AND 6200 FOOT
ELEVATIONS. WE EXPECT TO HAVE A NEW REPORT FROM CRATER LAKE
NATIONAL PARK LATER THIS MORNING, WHICH MAY HAVE RECEIVED A LITTLE
MORE THAN TEHSE MENTIONED SNOTELS. FURTHER SOUTH, FROM LAKE OF
THE WOODS TO MOUNT ASHLAND, SNOW REPORTS ABOVE 5000 FEET WERE 1 TO
3 INCHES.
THIS MORNING A 100 TO 130 KNOTS JET STREAM IS STILL PRESENT OVER
THE FORECAST AREA AT 30,000 FT MSL. THIS JET IS STREAMING HIGH
CLOUDS ACROSS THE AREA, WITH LOWER CLOUDS AND SOME FOG BELOW AT
MANY LOCATIONS. WE EXPECT THAT THESE CLOUDS WILL CONTINUE ACROSS
THE FORECAST AREA THROUGH MUCH OF THE DAY AS THE JET STREAM
REMAINS NEARLY STATIONARY, AND ACTUALLY STRENGTHENS SOME TO
120-145 KNOTS.
TODAY AND THEN MORE SO TONIGHT THROUGH TUESDAY THERE SUBSTANTIAL
DISAGREEMENT AMONGST THE MODELS AS TO HOW MUCH PRECIPITATION WILL
FALL ACROSS THE AREA AND WHERE IT WILL FALL. THE HRRR IS
INDICATING PRECIPITATION ALONG THE COAST AND COAST RANGE TODAY.
THE NAM AND SREF MODELS SHOW WIDESPREAD LIGHT PRECIPITATION
BEGINNING THIS EVENING AND CONTINUING THROUGH TUESDAY AFFECTING
NEARLY ALL OF THE FORECAST AREA, AT TIMES, WHEREAS THE GFS AND
ECMWF SHOW LESSER AMOUNTS AND KEEP IT MORE IN THE CASCADES, UMPQUA
BASIN, AND THE OREGON CASCADES. THIS PATTERN IS A FAVORABLE ONE
FOR LIGHT OVERRUNNING PRECIPITATION. WE OFTEN TERM IT A `HIGH
PRECIPITATION PROBABILITY, BUT LOW QPF` TYPE OF EVENT WHEN THIS
PATTERN OCCURS. HOWEVER, GIVEN MODEL DIFFERENCES, WHILE POPS HAVE
BEEN INCREASED, THEY MAY NEED TO BE INCREASED A BIT MORE,
ESPECIALLY IN THE HIGHER CONFIDENCE AREAS MENTIONED. IT IS NOTABLE
THAT THE 06Z GFS HAS TRENDED MORE TOWARD THE NAM12 AND SREF AND
THE THE 06Z NAM12 STUCK TO THE SAME SOLUTION AS WAS DEPICTED ON
THE 00Z RUN. THIS LENDS INCREASING CONFIDENCE IN THE WETTER NAM12
AND SREF SOLUTIONS. WITH THIS LIGHT PRECIPITATION, SNOW LEVELS
WILL BE OF SOME CONCERN, THOUGH IT APPEARS THAT THE OVERRUNNING IS
WEAK ENOUGH THAT WE SHOULD BE LOOKING AT RAIN AND SNOW RATHER THAN
ANY FREEZING RAIN.
SUNDAY THROUGH WEDNESDAY TEMPERATURES WILL BE WARMING
SIGNIFICANTLY ALOFT. IN FACT, THEY WARM TO ABOVE FREEZING TO ABOUT
THE 11,000 FOOT LEVEL. LOW DEWPOINTS SHOULD HELP TO PROTECT THE
SNOW PACK FROM TOO MUCH LOSS, BUT IT WILL STILL BE VERY NOTABLY
WARM. DUE TO GENERALLY LIGHT WINDS, HAVE UNDERCUT MODEL
TEMPERATURES GUIDANCE FOR HIGHS AT INTERIOR VALLEY LOCATIONS FOR
THIS TIME PERIOD.
IT DOES STILL LOOK LIKE A RETURN TO WET WEATHER THIS UPCOMING
WEEKEND. DETAILS ARE STILL TO BE DETERMINED, BUT SNOW LEVELS
LOOK AS IF THEY ARE MOST LIKELY TO BE ON THE HIGH SIDE WITH THAT
FRONTAL SYSTEM. IT CURRENTLY APPEARS THESE SNOW LEVELS WILL
REMAIN ABOVE THE PRIMARY MOUNTAIN PASSES THROUGH NEXT WEEKEND. BTL
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM PST MONDAY
FOR PZZ350-356-370-376.
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1156 AM CST SUN NOV 23 2014
.DISCUSSION...
UPDATED FOR 18Z AVIATION DISCUSSION
PREV DISCUSSION... /ISSUED 1027 AM CST SUN NOV 23 2014/
UPDATE...
WIDESPREAD RAIN CONTINUES TO SPREAD NORTHWARD OVER THE MIDSOUTH.
RAIN WILL BE AROUND FOR MUCH OF THE DAY. RIGHT NOW...ANY THUNDER
THAT IS OCCURRING IS TO THE SOUTH AND EAST OF THE CWA. CAN/T RULE
OUT A FEW EMBEDDED THUNDERSTORMS OCCURRING LATER THIS AFTERNOON.
CURRENT TEMPERATURES ARE IN THE UPPER 50S AND WILL LIKELY HOVER
AROUND THERE FOR MOST OF THE DAY. THERE IS A WARM FRONT LOCATED
ACROSS SOUTHERN MISSISSIPPI THAT WILL SURGE NORTHWARD LATE THIS
AFTERNOON INTO THE EARLY EVENING. TEMPERATURES COULD SHOOT UP
RIGHT BEFORE THE END OF THE DAY THUS AM RELUCTANT TO LOWER
FORECASTED HIGHS. CURRENT FORECAST LOOKS GOOD FOR NOW.
KRM
DISCUSSION.../ISSUED 438 AM CST SUN NOV 23 2014/
EARLY THIS MORNING...A MESOSCALE CONVECTIVE SYSTEM WAS MOVING
EASTWARD ALONG THE NORTHWEST GULF AHEAD OF A STRONG UPPER LEVEL
TROUGH. MOST OF THE MIDSOUTH REMAINED RAIN FREE WITH JUST SOME
PATCHY LIGHT RAIN. A WEAK FRONT EXTENDED ACROSS NORTHEAST AR AND THE
MO BOOTHEEL. SOUTHEAST WINDS WERE PUSHING MILDER AIR INTO THE AREA
TO THE SOUTHEAST OF THE FRONT WITH SOME TEMPERATURES NEAR THE 60
DEGREE MARK.
THE UPPER LEVEL TROUGH WILL MOVE EAST NORTHEASTWARD ACROSS THE
MIDSOUTH TODAY WITH A STRENGTHENING SURFACE LOW TO OUR WEST. THE GFS
INDICATES A 987 MB LOW OVER SOUTHWEST MO AT SUNSET WHILE THE ECMWF
HAS THE PRESSURE AT 992 MB. MODELS ARE STILL SHOWING WIDESPREAD
SHOWERS MOVING QUICKLY INTO THE MIDSOUTH FROM THE SOUTHWEST TODAY.
THE HRRR MODEL INDICATES THAT THE ENTIRE FORECAST AREA WILL HAVE
SOME RAIN BY NOON THAT WILL THEN PERSIST INTO THE AFTERNOON BEFORE
DIMINISHING FROM THE SOUTHWEST. SHOWERS WILL HELP TO HOLD
TEMPERATURES DOWN. THIS INITIAL UPPER LEVEL TROUGH IS FORECAST TO BE
MOVING TO THE NORTHEAST OF THE REGION BY 6 PM. PRECIPITABLE WATER
VALUES WILL CLIMB TO AROUND 1.5 INCHES TODAY AS SOUTHERLY WINDS
SURFACE AND ALOFT TAP INTO GULF MOISTURE. WILL CONTINUE TO MENTION
THE THREAT OF LOCALLY HEAVY RAINFALL IN THE HAZARDOUS WEATHER
OUTLOOK WITH SOME HEAVY DOWNPOURS. MOST SPOTS ARE EXPECTED TO PICK
UP AROUND AN INCH OF RAIN BUT SOME LOCATIONS MAY SEE 1 1/2 INCHES.
INSTABILITY WILL BE MARGINAL AT BEST WITH THIS SYSTEM FOR MOST OF
OUR AREA. HOWEVER...MODELS DO INDICATE SOME ELEVATED INSTABILITY AND
MAYBE A LITTLE SURFACE BASED INSTABILITY DEVELOPING OVER NORTHEAST
AR AND THE MO BOOTHEEL LATE THIS AFTERNOON AND EVENING. THIS WILL BE
AHEAD OF THE SURFACE LOW OVER MO AND A COLD FRONT TRAILING TO THE
SOUTH. IN ADDITION...DIFFLUENCE ALOFT DEVELOPS OVER THE REGION AHEAD
OF A TRAILING UPPER LEVEL TROUGH. WILL MENTION A FEW STRONG
THUNDERSTORMS FOR THIS AREA LATE THIS AFTERNOON AND EARLY EVENING
WITH STRONG GUSTY WINDS AND SMALL HAIL POSSIBLE...ALTHOUGH A
LIMITING FACTOR WILL BE THAT SURFACE DEW POINTS WILL STRUGGLE TO
EVEN REACH THE 60 DEGREE MARK.
THE COLD FRONT WILL MOVE QUICKLY THROUGH THE MIDSOUTH TONIGHT WITH A
CONTINUED CHANCE OF SHOWERS ACROSS THE AREA. THE BEST CHANCE WILL BE
FROM PORTIONS OF NORTHEAST AR AND THE MO BOOTHEEL INTO PORTIONS OF
NORTHWEST TN WHERE THE BEST UPPER LEVEL DYNAMICS WILL OCCUR WITH
THE SECONDARY UPPER LEVEL TROUGH. WINDS WILL INCREASE AND TURN TO
THE SOUTHWEST AND WEST TONIGHT INTO MONDAY. FOR NOW...HAVE THE WIND
SPEEDS JUST SHY OF NEEDING A WIND ADVISORY FOR A LARGE SECTION OF
THE AREA. WILL ADD TO THE HAZARDOUS WEATHER OUTLOOK THAT A WIND
ADVISORY MAY BECOME NECESSARY. NORTHEAST MS LOOKS TO BE THE AREA
LEAST LIKELY TO NEED A WIND ADVISORY.
COOLER AND DRIER AIR WILL SPREAD INTO THE AREA MONDAY ON BREEZY
WESTERLY WINDS. SKIES WILL BECOME PARTLY TO MOSTLY SUNNY.
TEMPERATURES WILL ONCE AGAIN DROP TO BELOW NORMAL LEVELS AND
CONTINUE THAT WAY FOR AT LEAST A FEW DAYS. KEPT THE FORECAST
PRECIPITATION FREE THROUGH SATURDAY. THE GFS DOES INDICATE A WEAK
CLIPPER TYPE SYSTEM MOVING ACROSS THE AREA WEDNESDAY BUT MOISTURE
LOOKS LIMITED WITH MAINLY JUST AN INCREASE IN MIDDLE LEVEL CLOUDS
EXPECTED.
THE ECMWF AND GFS ARE SIGNIFICANTLY DIFFERENT BEGINNING THANKSGIVING
DAY. THE ECMWF SHOWS MODIFIED ARCTIC AIR SLOWLY PUSHING INTO THE
AREA FROM THE NORTH THURSDAY AFTERNOON THROUGH SATURDAY. THE GFS
PUSHES THE COLD HIGH TO THE EAST WITH WINDS TURNING TO THE SOUTH
ACROSS THE MIDSOUTH. THIS RESULTS IN HUGE DIFFERENCES IN
TEMPERATURES FOR THE REGION...ALTHOUGH CHANCES FOR PRECIPITATION
LOOK SMALL WITH EITHER SCENARIO. FOR NOW...KEPT CLOSE TO THE
EARLIER FORECAST EXCEPT BLENDED THE TEMPERATURES A LITTLE BETTER
WITH SURROUNDING OFFICES.
JCL
&&
.AVIATION...
18Z TAF CYCLE
WIDESPREAD RAIN AND IFR CONDITIONS HAVE SPREAD ACROSS THE
MIDSOUTH. RAIN WILL END FROM SW TO NE LATE THIS AFTERNOON AS
SYSTEM LIFTS THROUGH. THERE IS A SMALL CHANCE OF A TSRA AT KTUP
BUT POTENTIAL TOO LOW TO MENTION. CONDITIONS WILL LIFT TO MVFR AS
THE RAIN ENDS. HOWEVER EXPECT LOW CLOUDS TO REMAIN OVERNIGHT INTO
MONDAY MORNING EXCEPT THEY MAY CLEAR FOR A SHORT TIME AT KTUP
LATER THIS EVENING BEFORE FILLING BACK IN. WINDS WILL VEER FROM
THE SE TO THE SSW AT 10-12 KTS BY THIS EVENING AND INCREASE
MARKEDLY AS THE COLD FRONT MOVES THROUGH WITH GUSTS TO 30 KTS.
SJM
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1150 AM CST SUN NOV 23 2014
.DISCUSSION...
UPDATED FOR 18Z AVIATION DISCUSSION
&&
PREV DISCUSSION... /ISSUED 1027 AM CST SUN NOV 23 2014/
UPDATE...
WIDESPREAD RAIN CONTINUES TO SPREAD NORTHWARD OVER THE MIDSOUTH.
RAIN WILL BE AROUND FOR MUCH OF THE DAY. RIGHT NOW...ANY THUNDER
THAT IS OCCURRING IS TO THE SOUTH AND EAST OF THE CWA. CAN/T RULE
OUT A FEW EMBEDDED THUNDERSTORMS OCCURRING LATER THIS AFTERNOON.
CURRENT TEMPERATURES ARE IN THE UPPER 50S AND WILL LIKELY HOVER
AROUND THERE FOR MOST OF THE DAY. THERE IS A WARM FRONT LOCATED
ACROSS SOUTHERN MISSISSIPPI THAT WILL SURGE NORTHWARD LATE THIS
AFTERNOON INTO THE EARLY EVENING. TEMPERATURES COULD SHOOT UP
RIGHT BEFORE THE END OF THE DAY THUS AM RELUCTANT TO LOWER
FORECASTED HIGHS. CURRENT FORECAST LOOKS GOOD FOR NOW.
KRM
DISCUSSION.../ISSUED 438 AM CST SUN NOV 23 2014/
EARLY THIS MORNING...A MESOSCALE CONVECTIVE SYSTEM WAS MOVING
EASTWARD ALONG THE NORTHWEST GULF AHEAD OF A STRONG UPPER LEVEL
TROUGH. MOST OF THE MIDSOUTH REMAINED RAIN FREE WITH JUST SOME
PATCHY LIGHT RAIN. A WEAK FRONT EXTENDED ACROSS NORTHEAST AR AND THE
MO BOOTHEEL. SOUTHEAST WINDS WERE PUSHING MILDER AIR INTO THE AREA
TO THE SOUTHEAST OF THE FRONT WITH SOME TEMPERATURES NEAR THE 60
DEGREE MARK.
THE UPPER LEVEL TROUGH WILL MOVE EAST NORTHEASTWARD ACROSS THE
MIDSOUTH TODAY WITH A STRENGTHENING SURFACE LOW TO OUR WEST. THE GFS
INDICATES A 987 MB LOW OVER SOUTHWEST MO AT SUNSET WHILE THE ECMWF
HAS THE PRESSURE AT 992 MB. MODELS ARE STILL SHOWING WIDESPREAD
SHOWERS MOVING QUICKLY INTO THE MIDSOUTH FROM THE SOUTHWEST TODAY.
THE HRRR MODEL INDICATES THAT THE ENTIRE FORECAST AREA WILL HAVE
SOME RAIN BY NOON THAT WILL THEN PERSIST INTO THE AFTERNOON BEFORE
DIMINISHING FROM THE SOUTHWEST. SHOWERS WILL HELP TO HOLD
TEMPERATURES DOWN. THIS INITIAL UPPER LEVEL TROUGH IS FORECAST TO BE
MOVING TO THE NORTHEAST OF THE REGION BY 6 PM. PRECIPITABLE WATER
VALUES WILL CLIMB TO AROUND 1.5 INCHES TODAY AS SOUTHERLY WINDS
SURFACE AND ALOFT TAP INTO GULF MOISTURE. WILL CONTINUE TO MENTION
THE THREAT OF LOCALLY HEAVY RAINFALL IN THE HAZARDOUS WEATHER
OUTLOOK WITH SOME HEAVY DOWNPOURS. MOST SPOTS ARE EXPECTED TO PICK
UP AROUND AN INCH OF RAIN BUT SOME LOCATIONS MAY SEE 1 1/2 INCHES.
INSTABILITY WILL BE MARGINAL AT BEST WITH THIS SYSTEM FOR MOST OF
OUR AREA. HOWEVER...MODELS DO INDICATE SOME ELEVATED INSTABILITY AND
MAYBE A LITTLE SURFACE BASED INSTABILITY DEVELOPING OVER NORTHEAST
AR AND THE MO BOOTHEEL LATE THIS AFTERNOON AND EVENING. THIS WILL BE
AHEAD OF THE SURFACE LOW OVER MO AND A COLD FRONT TRAILING TO THE
SOUTH. IN ADDITION...DIFFLUENCE ALOFT DEVELOPS OVER THE REGION AHEAD
OF A TRAILING UPPER LEVEL TROUGH. WILL MENTION A FEW STRONG
THUNDERSTORMS FOR THIS AREA LATE THIS AFTERNOON AND EARLY EVENING
WITH STRONG GUSTY WINDS AND SMALL HAIL POSSIBLE...ALTHOUGH A
LIMITING FACTOR WILL BE THAT SURFACE DEW POINTS WILL STRUGGLE TO
EVEN REACH THE 60 DEGREE MARK.
THE COLD FRONT WILL MOVE QUICKLY THROUGH THE MIDSOUTH TONIGHT WITH A
CONTINUED CHANCE OF SHOWERS ACROSS THE AREA. THE BEST CHANCE WILL BE
FROM PORTIONS OF NORTHEAST AR AND THE MO BOOTHEEL INTO PORTIONS OF
NORTHWEST TN WHERE THE BEST UPPER LEVEL DYNAMICS WILL OCCUR WITH
THE SECONDARY UPPER LEVEL TROUGH. WINDS WILL INCREASE AND TURN TO
THE SOUTHWEST AND WEST TONIGHT INTO MONDAY. FOR NOW...HAVE THE WIND
SPEEDS JUST SHY OF NEEDING A WIND ADVISORY FOR A LARGE SECTION OF
THE AREA. WILL ADD TO THE HAZARDOUS WEATHER OUTLOOK THAT A WIND
ADVISORY MAY BECOME NECESSARY. NORTHEAST MS LOOKS TO BE THE AREA
LEAST LIKELY TO NEED A WIND ADVISORY.
COOLER AND DRIER AIR WILL SPREAD INTO THE AREA MONDAY ON BREEZY
WESTERLY WINDS. SKIES WILL BECOME PARTLY TO MOSTLY SUNNY.
TEMPERATURES WILL ONCE AGAIN DROP TO BELOW NORMAL LEVELS AND
CONTINUE THAT WAY FOR AT LEAST A FEW DAYS. KEPT THE FORECAST
PRECIPITATION FREE THROUGH SATURDAY. THE GFS DOES INDICATE A WEAK
CLIPPER TYPE SYSTEM MOVING ACROSS THE AREA WEDNESDAY BUT MOISTURE
LOOKS LIMITED WITH MAINLY JUST AN INCREASE IN MIDDLE LEVEL CLOUDS
EXPECTED.
THE ECMWF AND GFS ARE SIGNIFICANTLY DIFFERENT BEGINNING THANKSGIVING
DAY. THE ECMWF SHOWS MODIFIED ARCTIC AIR SLOWLY PUSHING INTO THE
AREA FROM THE NORTH THURSDAY AFTERNOON THROUGH SATURDAY. THE GFS
PUSHES THE COLD HIGH TO THE EAST WITH WINDS TURNING TO THE SOUTH
ACROSS THE MIDSOUTH. THIS RESULTS IN HUGE DIFFERENCES IN
TEMPERATURES FOR THE REGION...ALTHOUGH CHANCES FOR PRECIPITATION
LOOK SMALL WITH EITHER SCENARIO. FOR NOW...KEPT CLOSE TO THE
EARLIER FORECAST EXCEPT BLENDED THE TEMPERATURES A LITTLE BETTER
WITH SURROUNDING OFFICES.
JCL
&&
.AVIATION...
18Z TAF CYCLE
WIDESPREAD RAIN AND IFR CONDITIONS HAVE SPREAD ACROSS THE
MIDSOUTH. RAIN WILL END FROM SW TO NE LATE THIS AFTERNOON AS
SYSTEM LIFTS THROUGH. THERE IS A SMALL CHANCE OF A TSRA AT KTUP
BUT POTENTIAL TOO LOW TO MENTION. CONDITIONS WILL LIFT TO MVFR AS
THE RAIN ENDS. HOWEVER EXPECT LOW CLOUDS TO REMAIN OVERNIGHT INTO
MONDAY MORNING EXCEPT THEY MAY CLEAR FOR A SHORT TIME AT KTUP
LATER THIS EVENING BEFORE FILLING BACK IN.
SJM
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1148 AM CST SUN NOV 23 2014
.UPDATE...
&&
.DISCUSSION...
&&
.PREV DISCUSSION... /ISSUED 1027 AM CST SUN NOV 23 2014/
UPDATE...
WIDESPREAD RAIN CONTINUES TO SPREAD NORTHWARD OVER THE MIDSOUTH.
RAIN WILL BE AROUND FOR MUCH OF THE DAY. RIGHT NOW...ANY THUNDER
THAT IS OCCURRING IS TO THE SOUTH AND EAST OF THE CWA. CAN/T RULE
OUT A FEW EMBEDDED THUNDERSTORMS OCCURRING LATER THIS AFTERNOON.
CURRENT TEMPERATURES ARE IN THE UPPER 50S AND WILL LIKELY HOVER
AROUND THERE FOR MOST OF THE DAY. THERE IS A WARM FRONT LOCATED
ACROSS SOUTHERN MISSISSIPPI THAT WILL SURGE NORTHWARD LATE THIS
AFTERNOON INTO THE EARLY EVENING. TEMPERATURES COULD SHOOT UP
RIGHT BEFORE THE END OF THE DAY THUS AM RELUCTANT TO LOWER
FORECASTED HIGHS. CURRENT FORECAST LOOKS GOOD FOR NOW.
KRM
DISCUSSION.../ISSUED 438 AM CST SUN NOV 23 2014/
EARLY THIS MORNING...A MESOSCALE CONVECTIVE SYSTEM WAS MOVING
EASTWARD ALONG THE NORTHWEST GULF AHEAD OF A STRONG UPPER LEVEL
TROUGH. MOST OF THE MIDSOUTH REMAINED RAIN FREE WITH JUST SOME
PATCHY LIGHT RAIN. A WEAK FRONT EXTENDED ACROSS NORTHEAST AR AND THE
MO BOOTHEEL. SOUTHEAST WINDS WERE PUSHING MILDER AIR INTO THE AREA
TO THE SOUTHEAST OF THE FRONT WITH SOME TEMPERATURES NEAR THE 60
DEGREE MARK.
THE UPPER LEVEL TROUGH WILL MOVE EAST NORTHEASTWARD ACROSS THE
MIDSOUTH TODAY WITH A STRENGTHENING SURFACE LOW TO OUR WEST. THE GFS
INDICATES A 987 MB LOW OVER SOUTHWEST MO AT SUNSET WHILE THE ECMWF
HAS THE PRESSURE AT 992 MB. MODELS ARE STILL SHOWING WIDESPREAD
SHOWERS MOVING QUICKLY INTO THE MIDSOUTH FROM THE SOUTHWEST TODAY.
THE HRRR MODEL INDICATES THAT THE ENTIRE FORECAST AREA WILL HAVE
SOME RAIN BY NOON THAT WILL THEN PERSIST INTO THE AFTERNOON BEFORE
DIMINISHING FROM THE SOUTHWEST. SHOWERS WILL HELP TO HOLD
TEMPERATURES DOWN. THIS INITIAL UPPER LEVEL TROUGH IS FORECAST TO BE
MOVING TO THE NORTHEAST OF THE REGION BY 6 PM. PRECIPITABLE WATER
VALUES WILL CLIMB TO AROUND 1.5 INCHES TODAY AS SOUTHERLY WINDS
SURFACE AND ALOFT TAP INTO GULF MOISTURE. WILL CONTINUE TO MENTION
THE THREAT OF LOCALLY HEAVY RAINFALL IN THE HAZARDOUS WEATHER
OUTLOOK WITH SOME HEAVY DOWNPOURS. MOST SPOTS ARE EXPECTED TO PICK
UP AROUND AN INCH OF RAIN BUT SOME LOCATIONS MAY SEE 1 1/2 INCHES.
INSTABILITY WILL BE MARGINAL AT BEST WITH THIS SYSTEM FOR MOST OF
OUR AREA. HOWEVER...MODELS DO INDICATE SOME ELEVATED INSTABILITY AND
MAYBE A LITTLE SURFACE BASED INSTABILITY DEVELOPING OVER NORTHEAST
AR AND THE MO BOOTHEEL LATE THIS AFTERNOON AND EVENING. THIS WILL BE
AHEAD OF THE SURFACE LOW OVER MO AND A COLD FRONT TRAILING TO THE
SOUTH. IN ADDITION...DIFFLUENCE ALOFT DEVELOPS OVER THE REGION AHEAD
OF A TRAILING UPPER LEVEL TROUGH. WILL MENTION A FEW STRONG
THUNDERSTORMS FOR THIS AREA LATE THIS AFTERNOON AND EARLY EVENING
WITH STRONG GUSTY WINDS AND SMALL HAIL POSSIBLE...ALTHOUGH A
LIMITING FACTOR WILL BE THAT SURFACE DEW POINTS WILL STRUGGLE TO
EVEN REACH THE 60 DEGREE MARK.
THE COLD FRONT WILL MOVE QUICKLY THROUGH THE MIDSOUTH TONIGHT WITH A
CONTINUED CHANCE OF SHOWERS ACROSS THE AREA. THE BEST CHANCE WILL BE
FROM PORTIONS OF NORTHEAST AR AND THE MO BOOTHEEL INTO PORTIONS OF
NORTHWEST TN WHERE THE BEST UPPER LEVEL DYNAMICS WILL OCCUR WITH
THE SECONDARY UPPER LEVEL TROUGH. WINDS WILL INCREASE AND TURN TO
THE SOUTHWEST AND WEST TONIGHT INTO MONDAY. FOR NOW...HAVE THE WIND
SPEEDS JUST SHY OF NEEDING A WIND ADVISORY FOR A LARGE SECTION OF
THE AREA. WILL ADD TO THE HAZARDOUS WEATHER OUTLOOK THAT A WIND
ADVISORY MAY BECOME NECESSARY. NORTHEAST MS LOOKS TO BE THE AREA
LEAST LIKELY TO NEED A WIND ADVISORY.
COOLER AND DRIER AIR WILL SPREAD INTO THE AREA MONDAY ON BREEZY
WESTERLY WINDS. SKIES WILL BECOME PARTLY TO MOSTLY SUNNY.
TEMPERATURES WILL ONCE AGAIN DROP TO BELOW NORMAL LEVELS AND
CONTINUE THAT WAY FOR AT LEAST A FEW DAYS. KEPT THE FORECAST
PRECIPITATION FREE THROUGH SATURDAY. THE GFS DOES INDICATE A WEAK
CLIPPER TYPE SYSTEM MOVING ACROSS THE AREA WEDNESDAY BUT MOISTURE
LOOKS LIMITED WITH MAINLY JUST AN INCREASE IN MIDDLE LEVEL CLOUDS
EXPECTED.
THE ECMWF AND GFS ARE SIGNIFICANTLY DIFFERENT BEGINNING THANKSGIVING
DAY. THE ECMWF SHOWS MODIFIED ARCTIC AIR SLOWLY PUSHING INTO THE
AREA FROM THE NORTH THURSDAY AFTERNOON THROUGH SATURDAY. THE GFS
PUSHES THE COLD HIGH TO THE EAST WITH WINDS TURNING TO THE SOUTH
ACROSS THE MIDSOUTH. THIS RESULTS IN HUGE DIFFERENCES IN
TEMPERATURES FOR THE REGION...ALTHOUGH CHANCES FOR PRECIPITATION
LOOK SMALL WITH EITHER SCENARIO. FOR NOW...KEPT CLOSE TO THE
EARLIER FORECAST EXCEPT BLENDED THE TEMPERATURES A LITTLE BETTER
WITH SURROUNDING OFFICES.
JCL
&&
.AVIATION...
WIDESPREAD RAIN AND IFR CONDITIONS HAVE SPREAD ACROSS THE
MIDSOUTH. RAIN WILL END FROM SW TO NE LATE THIS AFTERNOON AS
SYSTEM LIFTS THROUGH. THERE IS A SMALL CHANCE OF A TSRA AT KTUP
BUT POTENTIAL TOO LOW TO MENTION. CONDITIONS WILL LIFT TO MVFR AS
THE RAIN ENDS. HOWEVER EXPECT LOW CLOUDS TO REMAIN OVERNIGHT INTO
MONDAY MORNING EXCEPT THEY MAY CLEAR FOR A SHORT TIME AT KTUP
LATER THIS EVENING BEFORE FILLING BACK IN.
SJM
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1027 AM CST SUN NOV 23 2014
.UPDATE...
WIDESPREAD RAIN CONTINUES TO SPREAD NORTHWARD OVER THE MIDSOUTH.
RAIN WILL BE AROUND FOR MUCH OF THE DAY. RIGHT NOW...ANY THUNDER
THAT IS OCCURRING IS TO THE SOUTH AND EAST OF THE CWA. CAN/T RULE
OUT A FEW EMBEDDED THUNDERSTORMS OCCURRING LATER THIS AFTERNOON.
CURRENT TEMPERATURES ARE IN THE UPPER 50S AND WILL LIKELY HOVER
AROUND THERE FOR MOST OF THE DAY. THERE IS A WARM FRONT LOCATED
ACROSS SOUTHERN MISSISSIPPI THAT WILL SURGE NORTHWARD LATE THIS
AFTERNOON INTO THE EARLY EVENING. TEMPERATURES COULD SHOOT UP
RIGHT BEFORE THE END OF THE DAY THUS AM RELUCTANT TO LOWER
FORECASTED HIGHS. CURRENT FORECAST LOOKS GOOD FOR NOW.
KRM
&&
.DISCUSSION.../ISSUED 438 AM CST SUN NOV 23 2014/
EARLY THIS MORNING...A MESOSCALE CONVECTIVE SYSTEM WAS MOVING
EASTWARD ALONG THE NORTHWEST GULF AHEAD OF A STRONG UPPER LEVEL
TROUGH. MOST OF THE MIDSOUTH REMAINED RAIN FREE WITH JUST SOME
PATCHY LIGHT RAIN. A WEAK FRONT EXTENDED ACROSS NORTHEAST AR AND THE
MO BOOTHEEL. SOUTHEAST WINDS WERE PUSHING MILDER AIR INTO THE AREA
TO THE SOUTHEAST OF THE FRONT WITH SOME TEMPERATURES NEAR THE 60
DEGREE MARK.
THE UPPER LEVEL TROUGH WILL MOVE EAST NORTHEASTWARD ACROSS THE
MIDSOUTH TODAY WITH A STRENGTHENING SURFACE LOW TO OUR WEST. THE GFS
INDICATES A 987 MB LOW OVER SOUTHWEST MO AT SUNSET WHILE THE ECMWF
HAS THE PRESSURE AT 992 MB. MODELS ARE STILL SHOWING WIDESPREAD
SHOWERS MOVING QUICKLY INTO THE MIDSOUTH FROM THE SOUTHWEST TODAY.
THE HRRR MODEL INDICATES THAT THE ENTIRE FORECAST AREA WILL HAVE
SOME RAIN BY NOON THAT WILL THEN PERSIST INTO THE AFTERNOON BEFORE
DIMINISHING FROM THE SOUTHWEST. SHOWERS WILL HELP TO HOLD
TEMPERATURES DOWN. THIS INITIAL UPPER LEVEL TROUGH IS FORECAST TO BE
MOVING TO THE NORTHEAST OF THE REGION BY 6 PM. PRECIPITABLE WATER
VALUES WILL CLIMB TO AROUND 1.5 INCHES TODAY AS SOUTHERLY WINDS
SURFACE AND ALOFT TAP INTO GULF MOISTURE. WILL CONTINUE TO MENTION
THE THREAT OF LOCALLY HEAVY RAINFALL IN THE HAZARDOUS WEATHER
OUTLOOK WITH SOME HEAVY DOWNPOURS. MOST SPOTS ARE EXPECTED TO PICK
UP AROUND AN INCH OF RAIN BUT SOME LOCATIONS MAY SEE 1 1/2 INCHES.
INSTABILITY WILL BE MARGINAL AT BEST WITH THIS SYSTEM FOR MOST OF
OUR AREA. HOWEVER...MODELS DO INDICATE SOME ELEVATED INSTABILITY AND
MAYBE A LITTLE SURFACE BASED INSTABILITY DEVELOPING OVER NORTHEAST
AR AND THE MO BOOTHEEL LATE THIS AFTERNOON AND EVENING. THIS WILL BE
AHEAD OF THE SURFACE LOW OVER MO AND A COLD FRONT TRAILING TO THE
SOUTH. IN ADDITION...DIFFLUENCE ALOFT DEVELOPS OVER THE REGION AHEAD
OF A TRAILING UPPER LEVEL TROUGH. WILL MENTION A FEW STRONG
THUNDERSTORMS FOR THIS AREA LATE THIS AFTERNOON AND EARLY EVENING
WITH STRONG GUSTY WINDS AND SMALL HAIL POSSIBLE...ALTHOUGH A
LIMITING FACTOR WILL BE THAT SURFACE DEW POINTS WILL STRUGGLE TO
EVEN REACH THE 60 DEGREE MARK.
THE COLD FRONT WILL MOVE QUICKLY THROUGH THE MIDSOUTH TONIGHT WITH A
CONTINUED CHANCE OF SHOWERS ACROSS THE AREA. THE BEST CHANCE WILL BE
FROM PORTIONS OF NORTHEAST AR AND THE MO BOOTHEEL INTO PORTIONS OF
NORTHWEST TN WHERE THE BEST UPPER LEVEL DYNAMICS WILL OCCUR WITH
THE SECONDARY UPPER LEVEL TROUGH. WINDS WILL INCREASE AND TURN TO
THE SOUTHWEST AND WEST TONIGHT INTO MONDAY. FOR NOW...HAVE THE WIND
SPEEDS JUST SHY OF NEEDING A WIND ADVISORY FOR A LARGE SECTION OF
THE AREA. WILL ADD TO THE HAZARDOUS WEATHER OUTLOOK THAT A WIND
ADVISORY MAY BECOME NECESSARY. NORTHEAST MS LOOKS TO BE THE AREA
LEAST LIKELY TO NEED A WIND ADVISORY.
COOLER AND DRIER AIR WILL SPREAD INTO THE AREA MONDAY ON BREEZY
WESTERLY WINDS. SKIES WILL BECOME PARTLY TO MOSTLY SUNNY.
TEMPERATURES WILL ONCE AGAIN DROP TO BELOW NORMAL LEVELS AND
CONTINUE THAT WAY FOR AT LEAST A FEW DAYS. KEPT THE FORECAST
PRECIPITATION FREE THROUGH SATURDAY. THE GFS DOES INDICATE A WEAK
CLIPPER TYPE SYSTEM MOVING ACROSS THE AREA WEDNESDAY BUT MOISTURE
LOOKS LIMITED WITH MAINLY JUST AN INCREASE IN MIDDLE LEVEL CLOUDS
EXPECTED.
THE ECMWF AND GFS ARE SIGNIFICANTLY DIFFERENT BEGINNING THANKSGIVING
DAY. THE ECMWF SHOWS MODIFIED ARCTIC AIR SLOWLY PUSHING INTO THE
AREA FROM THE NORTH THURSDAY AFTERNOON THROUGH SATURDAY. THE GFS
PUSHES THE COLD HIGH TO THE EAST WITH WINDS TURNING TO THE SOUTH
ACROSS THE MIDSOUTH. THIS RESULTS IN HUGE DIFFERENCES IN
TEMPERATURES FOR THE REGION...ALTHOUGH CHANCES FOR PRECIPITATION
LOOK SMALL WITH EITHER SCENARIO. FOR NOW...KEPT CLOSE TO THE
EARLIER FORECAST EXCEPT BLENDED THE TEMPERATURES A LITTLE BETTER
WITH SURROUNDING OFFICES.
JCL
&&
.AVIATION...
12Z TAF CYCLE
CIGS WILL CONTINUE TO LOWER EARLY THIS MORNING TO MVFR CONDITIONS
AS A LARGE SHIELD OF RAINFALL APPROACHES FROM THE SOUTHWEST.
MODERATE RAINFALL WILL OVERSPREAD ALL TERMINALS BY
14/15Z...DEPENDING ON THE TERMINAL. INTERMITTENT IFR CONDITIONS
ARE LIKELY AS CIGS CONTINUE TO LOWER IN PRECIP. A GOOD SIGNAL
EXISTS FOR LOWERED VISBYS AS WELL...ESPECIALLY AT TUP WHERE BETTER
LOW LEVEL MOISTURE IS ALREADY IN PLACE. FOR THIS REASON...HAVE
INSERTED BR AT ALL TERMINALS THROUGH 00Z. BEST CHANCE FOR
THUNDERSTORMS EXISTS AT MKL AND TUP THROUGH THE EARLY
AFTERNOON. ATMOSPHERIC INSTABILITY AT MEM AND JBR DOES NOT LOOK
SUPPORTIVE OF THUNDER MENTION AT THIS TIME...BUT WILL WATCH TRENDS
THROUGH THE MORNING. SLOWLY RAISE CIGS AFTER 03-06Z AT ALL
TERMINALS AS WINDS INCREASE DRAMATICALLY FROM THE WEST WITH COLD
FRONTAL PASSAGE. THIS WILL OCCUR EARLIER AT WESTERN TERMINALS AND
LATER AT EASTERN TERMINALS. WINDS COULD GUST TOWARD 30KTS BEHIND
THE FRONT.
TVT
&&
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
1154 AM CST SUN NOV 23 2014
.UPDATE...
FOR THIS AFTERNOON...TWEAKED AFTERNOON TEMPERATURES FOR THE FRONTAL
PASSAGE. WE HAVE ALREADY REACHED MAXIMUMS ACROSS MUCH OF THE AREA AND
TEMPERATURES WILL CONTINUE DOWNWARD SPIRAL FOR REST OF AFTERNOON.
UPGRADED PRECIPITATION TO CATEGORICAL VALUES AS A LARGE AREA OF LIGHT
PRECIPITATION CONTINUES TO TRAVEL SOUTHEAST ACROSS THE PANHANDLES.
LIGHT RAIN...BUT WITH COLDER AIR...FLURRIES WILL BE POSSIBLE FOR THE
AFTERNOON HOURS. A POSSIBLE DUSTING OF SNOW IN A FEW LOCATIONS OF THE
WESTERN AND NORTHERN TEXAS PANHANDLE AND OKLAHOMA PANHANDLE ...BUT
OTHERWISE DO NOT EXPECT WIDESPREAD SIGNIFICANT ACCUMULATIONS. WINDS
WILL REMAIN GUSTY AND THE WIND ADVISORY WILL CONTINUE.
PRECIPITATION...CLOUDS AND WINDS SHOULD ALL BE ON THE DECREASE AFTER
SUNSET LEADING TO A COLD OVERNIGHT.
GARCIA
&&
.PREV DISCUSSION... /ISSUED 1117 AM CST SUN NOV 23 2014/
AVIATION...
18Z TAFS...A COLD FRONT CONTINUES TO RACE SOUTHWARD ACROSS THE
PANHANDLES. WINDS BEHIND THE FRONT WILL BE A SIGNIFICANT AVIATION
CONCERN THROUGH 00Z. WINDS OF 30 KNOTS WITH GUSTS TO 40 KNOTS ARE
FORECST AT KAMA...KDHT AND KGUY. LIGHT SHOWERS WITH SOME SNOW
FLURRIES ARE ALSO FORECAST FOR MUCH OF THE AFTERNOON. THESE SHOWERS
COULD TEMPORARILY REDUCE CIELINGS AND VISIBILTIES TO MVFR CONDITIONS
FOR A FEW HOURS. AFTER 00Z SHOWERS AND WINDS WILL BE ON THE DECREASE.
WINDS WILL LIGHTEN TO LESS THAN 15 KNOTS AND EXPECT CLOUDS WILL BE
DISSIPATING WITH CLEARING AFTER 06Z.
GARCIA
PREV DISCUSSION... /ISSUED 546 AM CST SUN NOV 23 2014/
AVIATION...
12Z TAFS...A COLD FRONT WILL PUSH THROUGH THE PANHANDLES THIS
MORNING...WITH STRONG NORTH/NORTHWEST WINDS KICKING UP BEHIND IT.
WINDS WILL REACH SUSTAINED SPEEDS AROUND 30 KTS WITH GUSTS TO AROUND
40 KTS...BEFORE DISSIPATING LATE THIS AFTERNOON AS THE PRESSURE
GRADIENT BEGINS TO RELAX. AN AVIATION WEATHER WARNING WILL BE IN
EFFECT FOR KAMA FROM 14Z-22Z. A PERIOD OF MVFR CIGS IS EXPECTED
BEHIND THE FRONT...AND SOME LIGHT RAIN OR SNOW SHOWERS WILL ALSO BE
POSSIBLE FOR ABOUT A 4-HOUR PERIOD IN WAKE OF THE FRONT. COMBINATION
OF THE STRONG WINDS AND LIGHT PRECIPITATION...ALONG WITH POSSIBLE
BLDU...MAY RESULT IN SOME MVFR VSBYS. CONDITIONS WILL IMPROVE LATE
THIS AFTERNOON AS WINDS START TO DIMINISH AND VFR CONDITIONS RETURN
FOR THE REMAINDER OF THE TAF PERIOD.
KB
PREV DISCUSSION... /ISSUED 302 AM CST SUN NOV 23 2014/
DISCUSSION...
VIGOROUS UPPER LEVEL SHORT WAVE TROUGH CROSSING THE ROCKIES WILL
DRIVE A STRONG CANADIAN COLD FRONT THROUGH THE REGION THIS
MORNING. WINDS ARE EXPECTED TO REACH WIND ADVISORY CRITERIA
WITH THIS FRONT FROM LATE THIS MORNING INTO THE EARLY AFTERNOON.
SURFACE PRESSURE GRADIENT ALONG WITH 850MB AND 700 MB HEIGHT
GRADIENTS ALL POINT TO THE POTENTIAL OF SUSTAINED 35 MPH WINDS
WITH HIGHER GUSTS. HAVE ADDED THE MENTION OF BLOWING DUST WITH
THESE HIGHER WINDS AS WELL. MODELS HAVE ALSO COME IN WETTER WITH THIS
SYSTEM. LATEST TTU WRF AND HRRR MODELS SUGGEST THAT AT LEAST SOME
KIND OF BAND OF PRECIP WILL TRAVERSE THE PANHANDLES TODAY. HAVE GONE
AHEAD AND INCREASED THE POPS TO 30 PERCENT ACROSS THE PANHANDLES.
BELIEVE THAT THE PRECIP COULD BE RAIN OR SNOW. AS THE DAY WEARS ON
THE COLUMN COOLS QUITE A BIT. THE ENTIRE CLOUD LAYER REMAINS BELOW 0
DEGREES CELSIUS AND THERE IS MOISTURE IN THE -10 TO -20 DEGREE
CELSIUS RANGE TO HELP FORM SOME SNOW FLAKES. TEMPERATURES MAY
ACTUALLY HOLD STEADY OR FALL THIS AFTERNOON AS THICKNESSES CRASH. SO
WOULD NOT BE SURPRISED TO SEE SOME SNOW SHOWERS WITH TEMPERATURES IN
THE LOWER 40S.
A FEW SNOW SHOWERS MAY LINGER NEAR THE NEW MEXICO STATE LINE
TONIGHT IN THE BEST UPSLOPE AREA...BUT THEY WILL REMAIN LIGHT.
AFTER TONIGHT THIS SYSTEM MOVES OFF TO OUR EAST AND A NORTHWEST FLOW
ALOFT DOMINATES THE PANHANDLES FOR THE EARLY PART OF THE WEEK.
THE MODELS START TO DIFFER SOMEWHAT BY THANKSGIVING. THE GFS
BROADENS AN UPPER LEVEL RIDGE ACROSS THE SOUTHERN ROCKIES AND
SOUTHERN HIGH PLAINS. MEANWHILE...THE ECMWF TRIES TO CARVE OUT AN
UPPER LEVEL TROUGH FROM SOUTHWEST CANADA INTO THE CENTRAL
PLAINS...WHICH WOULD PUSH ANOTHER CANADIAN COLD FRONT THROUGH THE
AREA BY THANKSGIVING AFTERNOON LEAVING FRIDAY AND SATURDAY COLDER.
THE GFS DOES NOT BRING IN THE COLDER AIR UNTIL NEXT WEEKEND. FOR
NOW HAVE GONE WITH A COMPROMISE WITH THE TEMPERATURES. AT ANY RATE
THE MODELS REMAIN DRY AFTER TONIGHT.
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR THE FOLLOWING
ZONES: ARMSTRONG...CARSON...COLLINGSWORTH...DALLAM...DEAF
SMITH...DONLEY...GRAY...HANSFORD...HARTLEY...HEMPHILL...
HUTCHINSON...LIPSCOMB...MOORE...OCHILTREE...OLDHAM...
POTTER...RANDALL...ROBERTS...SHERMAN...WHEELER.
OK...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR THE FOLLOWING
ZONES: BEAVER...CIMARRON...TEXAS.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
1117 AM CST SUN NOV 23 2014
.AVIATION...
18Z TAFS...A COLD FRONT CONTINUES TO RACE SOUTHWARD ACROSS THE
PANHANDLES. WINDS BEHIND THE FRONT WILL BE A SIGNIFICANT AVIATION
CONCERN THROUGH 00Z. WINDS OF 30 KNOTS WITH GUSTS TO 40 KNOTS ARE
FORECST AT KAMA...KDHT AND KGUY. LIGHT SHOWERS WITH SOME SNOW
FLURRIES ARE ALSO FORECAST FOR MUCH OF THE AFTERNOON. THESE SHOWERS
COULD TEMPORARILY REDUCE CIELINGS AND VISIBILTIES TO MVFR CONDITIONS
FOR A FEW HOURS. AFTER 00Z SHOWERS AND WINDS WILL BE ON THE DECREASE.
WINDS WILL LIGHTEN TO LESS THAN 15 KNOTS AND EXPECT CLOUDS WILL BE
DISSIPATING WITH CLEARING AFTER 06Z.
GARCIA
&&
.PREV DISCUSSION... /ISSUED 546 AM CST SUN NOV 23 2014/
AVIATION...
12Z TAFS...A COLD FRONT WILL PUSH THROUGH THE PANHANDLES THIS
MORNING...WITH STRONG NORTH/NORTHWEST WINDS KICKING UP BEHIND IT.
WINDS WILL REACH SUSTAINED SPEEDS AROUND 30 KTS WITH GUSTS TO AROUND
40 KTS...BEFORE DISSIPATING LATE THIS AFTERNOON AS THE PRESSURE
GRADIENT BEGINS TO RELAX. AN AVIATION WEATHER WARNING WILL BE IN
EFFECT FOR KAMA FROM 14Z-22Z. A PERIOD OF MVFR CIGS IS EXPECTED
BEHIND THE FRONT...AND SOME LIGHT RAIN OR SNOW SHOWERS WILL ALSO BE
POSSIBLE FOR ABOUT A 4-HOUR PERIOD IN WAKE OF THE FRONT. COMBINATION
OF THE STRONG WINDS AND LIGHT PRECIPITATION...ALONG WITH POSSIBLE
BLDU...MAY RESULT IN SOME MVFR VSBYS. CONDITIONS WILL IMPROVE LATE
THIS AFTERNOON AS WINDS START TO DIMINISH AND VFR CONDITIONS RETURN
FOR THE REMAINDER OF THE TAF PERIOD.
KB
PREV DISCUSSION... /ISSUED 302 AM CST SUN NOV 23 2014/
DISCUSSION...
VIGOROUS UPPER LEVEL SHORT WAVE TROUGH CROSSING THE ROCKIES WILL
DRIVE A STRONG CANADIAN COLD FRONT THROUGH THE REGION THIS
MORNING. WINDS ARE EXPECTED TO REACH WIND ADVISORY CRITERIA
WITH THIS FRONT FROM LATE THIS MORNING INTO THE EARLY AFTERNOON.
SURFACE PRESSURE GRADIENT ALONG WITH 850MB AND 700 MB HEIGHT
GRADIENTS ALL POINT TO THE POTENTIAL OF SUSTAINED 35 MPH WINDS
WITH HIGHER GUSTS. HAVE ADDED THE MENTION OF BLOWING DUST WITH
THESE HIGHER WINDS AS WELL. MODELS HAVE ALSO COME IN WETTER WITH THIS
SYSTEM. LATEST TTU WRF AND HRRR MODELS SUGGEST THAT AT LEAST SOME
KIND OF BAND OF PRECIP WILL TRAVERSE THE PANHANDLES TODAY. HAVE GONE
AHEAD AND INCREASED THE POPS TO 30 PERCENT ACROSS THE PANHANDLES.
BELIEVE THAT THE PRECIP COULD BE RAIN OR SNOW. AS THE DAY WEARS ON
THE COLUMN COOLS QUITE A BIT. THE ENTIRE CLOUD LAYER REMAINS BELOW 0
DEGREES CELSIUS AND THERE IS MOISTURE IN THE -10 TO -20 DEGREE
CELSIUS RANGE TO HELP FORM SOME SNOW FLAKES. TEMPERATURES MAY
ACTUALLY HOLD STEADY OR FALL THIS AFTERNOON AS THICKNESSES CRASH. SO
WOULD NOT BE SURPRISED TO SEE SOME SNOW SHOWERS WITH TEMPERATURES IN
THE LOWER 40S.
A FEW SNOW SHOWERS MAY LINGER NEAR THE NEW MEXICO STATE LINE
TONIGHT IN THE BEST UPSLOPE AREA...BUT THEY WILL REMAIN LIGHT.
AFTER TONIGHT THIS SYSTEM MOVES OFF TO OUR EAST AND A NORTHWEST FLOW
ALOFT DOMINATES THE PANHANDLES FOR THE EARLY PART OF THE WEEK.
THE MODELS START TO DIFFER SOMEWHAT BY THANKSGIVING. THE GFS
BROADENS AN UPPER LEVEL RIDGE ACROSS THE SOUTHERN ROCKIES AND
SOUTHERN HIGH PLAINS. MEANWHILE...THE ECMWF TRIES TO CARVE OUT AN
UPPER LEVEL TROUGH FROM SOUTHWEST CANADA INTO THE CENTRAL
PLAINS...WHICH WOULD PUSH ANOTHER CANADIAN COLD FRONT THROUGH THE
AREA BY THANKSGIVING AFTERNOON LEAVING FRIDAY AND SATURDAY COLDER.
THE GFS DOES NOT BRING IN THE COLDER AIR UNTIL NEXT WEEKEND. FOR
NOW HAVE GONE WITH A COMPROMISE WITH THE TEMPERATURES. AT ANY RATE
THE MODELS REMAIN DRY AFTER TONIGHT.
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR THE FOLLOWING
ZONES: ARMSTRONG...CARSON...COLLINGSWORTH...DALLAM...DEAF
SMITH...DONLEY...GRAY...HANSFORD...HARTLEY...HEMPHILL...
HUTCHINSON...LIPSCOMB...MOORE...OCHILTREE...OLDHAM...
POTTER...RANDALL...ROBERTS...SHERMAN...WHEELER.
OK...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR THE FOLLOWING
ZONES: BEAVER...CIMARRON...TEXAS.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS PORTLAND OR
256 PM PST SUN NOV 23 2014
.SYNOPSIS...A FRONT IS SHIFTING SOUTH ACROSS NW OREGON THIS
EVENING...AND SHOULD WEAKEN OVER THE AREA LATE TONIGHT. SOME
THUNDERSTORMS WILL ACCOMPANY THIS FRONT THROUGH THE EARLY EVENING.
VALLEY FOG SHOULD DEVELOP EARLY MONDAY MORNING. A WARMER FRONTAL
SYSTEM WILL BRING ADDITIONAL RAIN TO THE AREA MONDAY AFTERNOON
THROUGH THURSDAY NIGHT. A DRY DAY IS EXPECTED WEDNESDAY BEFORE
ANOTHER FRONT MOVES THROUGH ON THANKSGIVING DAY.
&&
.SHORT TERM...TODAY THROUGH WEDNESDAY...THE COLD FRONT THAT STALLED
OVER SW WASHINGTON THIS MORNING HAS MOVED SOUTH INTO OREGON EARLY THIS
AFTERNOON...GENERATING PLENTY OF LIGHTNING...THUNDER AND HEAVY RAIN
FOR NW OREGON. THE FRONT...AND THUNDERSTORMS WILL CONTINUE TO MOVE
SOUTH LATE THIS AFTERNOON AS WILL THE THREAT FOR THUNDERSTORMS.
THUNDERSTORMS MAY MAKE IT DOWN TO THE SALEM AREA AROUND 4 PM AND
POSSIBLY EVEN FURTHER SOUTH THAN THAT...DOWN TO ALBANY AROUND 5 PM.
HOWEVER THE FRONT IS EXPECTED TO WEAKEN AROUND SUNSET...AND THINK THE
THREAT FOR CONVECTION WILL WEAKEN AS WELL.
THE PRECIPITATION BAND WILL PUSH SOUTH OF THE WASHINGTON CASCADES
THIS AFTERNOON AND HAVE CANCELED THE WINTER WEATHER ADVISORY. THE
RAIN WILL DECREASE AS IT MOVES SOUTH THIS EVENING...AND AM NOT SURE
WHETHER ANY RAIN WILL MAKE IT TO EUGENE. IF SO...IT SHOULD BE BRIEF
WITH LIGHT ACCUMULATIONS. EXPECT THE RAIN TO END BY MIDNIGHT TONIGHT
WITH CLEARING SKIES LEADING TO FOG IN THE INTERIOR VALLEYS BY MONDAY
MORNING.
THE NEXT FRONTAL SYSTEM WILL APPROACH MONDAY. A WARM FRONT FROM THE
SOUTH WILL MERGE WITH A COLDER FRONT TO THE NORTH OFFSHORE BEFORE
PUSHING ONSHORE MONDAY AFTERNOON. THE WARMER PORTION OF THE FRONT
WILL FIRST MOVE ONSHORE MONDAY AFTERNOON...BEFORE THE COLDER FRONT
MOVES IN MONDAY NIGHT AND TUESDAY. THE SNOW LEVELS SHOULD RISE WELL
ABOVE THE CASCADE PASSES BY MONDAY AFTERNOON.
THE FRONT SHOULD MOVE NORTH TUESDAY AFTERNOON AND EVENING AS A AN
UPPER RIDGE BUILDS OVER THE AREA AND A LARGE UPPER LOW MOVES INTO THE
NE PACIFIC. THE RAIN SHOULD MAINLY BE CONFINED TO THE NORTHERN COAST
RANGE...COAST...AND NORTHERN CASCADES BY TUESDAY EVENING. BESIDES A
FEW MORNING SHOWERS OVER SW WASHINGTON EARLY WEDNESDAY MORNING...MOST
OF WEDNESDAY WILL BE DRY. SHOULD BE A RETURN OF VALLEY FOG WEDNESDAY
MORNING.
.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY...MODELS CONTINUE TO
SHOW A PACIFIC FRONTAL SYSTEM...ASSOCIATED WITH AN UPPER LEVEL
SHORTWAVE...MOVING ACROSS NW OREGON AND SW WASHINGTON ON
THANKSGIVING DAY. THERE ARE STILL SOME DISCREPANCIES OF WHEN THE
RAIN WILL START. THE ECMWF BRINGS THE FRONT ONSHORE DURING THE EARLY
MORNING HOURS WHILE THE GFS HOLDS OFF UNTIL DAYBREAK. EXPECT CHANCE
POPS THROUGH FRIDAY. THE MAIN UPPER LEVEL TROUGH MOVES ONSHORE OVER
THE WEEKEND AND WILL BRING A MUCH STRONGER AND WETTER SYSTEM. SNOW
LEVELS OVER THE WEEKEND COULD DROP TO THE PASSES. AS OF NOW...IT
LOOKS LIKE WE CAN EXPECT TO SEE HAZARDOUS TRAVEL CONDITIONS FOR
THOSE RETURNING AFTER THE THANKSGIVING HOLIDAY. TEMPERATURES IN THE
EXTENDED CONTINUE TO BE AT OR ABOVE SEASONAL NORMALS. DETAILS OF THE
IMPACTS EXPECTED FROM NEXT WEEKENDS SYSTEM WILL CONTINUE TO BE
REFINED WITH FUTURE UPDATES. /64
&&
.AVIATION...A BAND OF RAIN ASSOCIATED WITH A WEAKENING FRONTAL
BOUNDARY IS CURRENTLY DRAPED FROM JUST SOUTH OF TILLAMOOK THROUGH
THE NORTHERN AND CENTRAL WILLAMETTE VALLEY. THIS BOUNDARY WILL
PUSH SLOWLY SOUTH AND WEAKEN FURTHER LATER THIS AFTERNOON AND THIS
EVENING. EXPECT PRIMARILY VFR CONDITIONS DURING THIS TIME...WITH
AREAS OF MVFR FROM TIME TO TIME UNDERNEATH THE HEAVIER RAIN BAND.
THERE IS ALSO STILL ISOLATED THUNDER BEING DETECTED ALONG THE
FRONTAL BOUNDARY...BUT THIS THREAT SHOULD END BY EARLY EVENING.
EXPECT SOME CLEARING TO DEVELOP LATER THIS EVENING AND
OVERNIGHT AND THE ATMOSPHERE BEGINS TO STABILIZE. THIS SHOULD
ALLOW SOME PATCHY MVFR OR IFR FOG OR LOW STRATUS TO FORM
OVERNIGHT INTO EARLY MON MORNING. ANOTHER FRONT WILL BEGIN TO
SPREAD LIGHT RAIN AND POSSIBLY MVFR CIGS INTO THE COAST BETWEEN
21Z AND 00Z MON.
KPDX AND APPROACHES...A BAND OF RAIN ASSOCIATED WITH A WEAKENING
FRONT MAY TEMPORARILY REDUCE CIGS INTO MVFR THROUGH 00Z. SOME
CLEARING TONIGHT MAY ALLOW PATCHY FOG OR LOW STRATUS TO FORM
OVERNIGHT OR EARLY MON MORNING. PYLE
&&
.MARINE...A WEAKENING FRONT HAS MOVED SLOWLY FROM NORTH TO SOUTH
THROUGH THE WATERS TODAY...AND IS NOW LOCATED JUST SOUTH OF
TILLAMOOK. THERE IS STILL ISOLATED THUNDER BEING DETECTED ALONG
THE FRONT...BUT EXPECT THIS THREAT TO END BY LATE AFTERNOON OR
EARLY EVENING. WINDS HAVE DROPPED OFF THIS AFTERNOON AS THE FRONT
HAS WEAKENED...AND ARE NOW WESTERLY AT AROUND 10 TO 15 KT.
THUS...WILL ALLOW THE SMALL CRAFT ADVISORY FOR WINDS TO DROP OFF
AT 3 PM. EXPECT THE LULL IN THE WINDS TO LAST INTO EARLY MON. THEN
THE NEXT FRONT IS EXPECTED TO MOVE INTO THE WATERS TOMORROW. THE
LATEST FCST MODELS ARE INDICATING THAT LOW END GALE FORCE WINDS
ARE A POSSIBILITY TOMORROW...MAINLY DURING THE AFTERNOON AND EARLY
EVENING. DECIDED TO ISSUE A GALE WATCH STARTING AT 10 AM.
WINDS MAY STAY A BIT GUSTIER ACROSS THE NORTHERN WATERS THROUGH MID
WEEK BEFORE A SLOW MOVING LOW PRESSURE SYSTEM BEGINS TO IMPACT THE
WATERS MID TO LATE NEXT WEEK. LOW END GALE FORCE WIND GUSTS MIGHT
BE SQUEEZED OUT OF THIS SYSTEM AT SOME POINT...BUT THE SCENARIO
DOES NOT LOOK ALL THAT PROMISING FOR A SOLID GALE FORCE OR HIGHER
WIND EVENT FOR THE WATERS.
SEAS HAVE COME UP JUST A BIT TODAY...AND ARE NOW AROUND 12 TO 14
FT. EXPECT THEM TO REMAIN FAIRLY STEADY THROUGH THIS EVENING
BEFORE GRADUALLY DECREASING OVERNIGHT AND MON. HOWEVER...EXPECT
SEAS TO REMAIN ABOVE 10 FT INTO EARLY WED. PYLE
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...WINTER WEATHER ADVISORY UNTIL 3 PM PST THIS AFTERNOON FOR SOUTH
WASHINGTON CASCADES.
PZ...GALE WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING FOR
COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 AM PST MONDAY
FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60
NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 9 AM PST
MONDAY.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
[top]
Area Forecast Discussion
National Weather Service Spokane WA
231 PM PST SUN NOV 23 2014
.SYNOPSIS...
The north Idaho mountains will continue to receive snow this
evening, along with the Cascade crest near Stevens Pass. The
breezy winds will taper off overnight, and Monday will be a
relatively quiet and chilly day. More rain and heavy mountain snow
is expected Monday night into Tuesday. A breezy and wet but warm
Thanksgiving Day will give way to a colder weather pattern for the
holiday weekend with the mountains receiving several rounds of
snow. Snow levels will fall to valley floors by the weekend.
&&
.DISCUSSION...
Tonight and Monday: A temporary break in the wet weather can be
expected starting tonight. A moist and progressive cold front will
push south and east of Spokane and through north Idaho early this
evening. Somewhat drier air will move into the region from the
northwest, although enough residual moisture and favorable
orographic flow will keep the threat of mountain showers. This is
especially true along the Cascade crest near Stevens Pass where
hints of a PVCZ may linger and then Central Idaho panhandle
mountains. The only concern for accumulating valley snow would be
north of Bonners Ferry, but the front will quickly exit this area
and allow the threat of snow to taper off. Meanwhile, either the
valley locations will be done with snow for the evening, or have
warmed up and should just experience rain this evening especially
across the central and southern Idaho panhandle. Breezy winds will
continue into the early evening behind the front with gusts to 30
mph. These winds will decrease overnight and become light by
Monday as surface pressure gradients relax. Skies will clear for a
good chunk of eastern Washington. This coupled with lighter winds,
wet ground and radiational cooling will lead to rather chilly
temperatures overnight into the 20s. These sub freezing lows and
frozen ground will also raise the risk of icy roadways by early
Monday morning for the commute. Meanwhile, boundary layer moisture
remains high overnight especially across the Palouse and
Spokane/Coeur d`Alene area. Given the southwest winds and light
precipitation today, there is a good chance of seeing stratus and
patchy fog develop late tonight into Monday morning. This threat
will expand into the northern and Panhandle valleys as well. By
Monday, the low cloud deck will gradually erode but daytime
temperatures will be inhibited by the cloud cover. In addition,
mid and high level clouds will be on the increase as the next
weather system approaches. /rfox.
Monday night through Thursday morning...No major changes for the
mid forecast time frame. High pressure will build in the eastern
Pacific just off the coast. This will put the Inland Northwest in
a northwest flow...before coming around to westerly Wednesday
night. This flow will tap in deep Pacific moisture tap to move
over the ridge and drop through the region through the period. We
are looking at an extended wet and unsettled period through early
Wednesday evening.
* Precipitation: You bet. Precipitable water by Tuesday morning
will approach an inch which is around 270% of normal. Quite wet
indeed. Isentropic up-glide will get established over Pac NW
early Tuesday evening and remain in place through Wednesday
afternoon. A pretty substantial rain shadow will develop in the
lee of the Cascades keeping the lower east slopes and the deep
basin from getting much more than a few hundredths to maybe a
tenth of an inch. Outside of the basin the lower elevations and
northern mountains look to get from .25 to .55 if not slightly
more. The Panhandle mountains from .50 to .80 and the higher
elevation of the Cascades from .50 to well over an inch near the
crest.
* Snow: A much trickier questions. Southerly surface winds and
strong warm advection is what will cause the lifting procees to
squeeze out all the moisture. But this will also raise snow
levels rapidly Tuesday night. For all of the urban areas snow
levels will be high enough for precipitation as all rain. The
tricky parts will be the mountain valleys. By the time the
heaviest precipitation gets into these areas the snow should
turn to rain. At this time snow accumulations for all of the
mountain valleys remain below highlight criteria. An even
trickier snow forecast will be for northeast WA and ID Panhandle
mountains above 3-4k feet where the same processes will be at
work, but it will take a little longer to warm. 24 hour snow
amounts will range from 6-9 inches which would be the low end of
an advisory. I will hold off on any highlights...first because
we already have advisories out for the central Panhandle
mountains and second there is still a little uncertainty on just
how fast temperatures will increase.
* Temperatures and wind: As mentioned above there will be strong
warm air advection and breezy/gusty south-southwest winds.
Temperatures on Tuesday will increase with high from the mid 30s
across the north to the high 40s/lower 50s across the south.
Then add 4-5 more degrees for Wednesday putting highs well into
the 40s and 50s. South-southwest of 10-25 mph with gusts 25-35
mph will be common across the region. /Tobin
Thanksgiving Day through Sunday...Another day, another fight
between medium range models. Why can`t we just get along? The
00Z run of the ECMWF was showing an arctic front dropping south
across the forecast area Thanksgiving Day, leading to a much
colder forecast than the more consistent GFS. Surprise...the 12Z
EC is much closer to the GFS solution. There are still differences
in several of the details but the general consensus is for warmer
temperatures in southerly flow at least through Turkey Day. The
stream of shortwave energy riding over the forecast area will
bring some precipitation to the higher elevations of the Inland
Northwest but valley precip is one of those pesky details that
model are having a hard time deciding on, depending on the
location of the upper jet and associated areas of enhanced lift.
This jet will be directing a fetch of deep moisture into the
region with Pwats approaching 200 percent of normal. At least
there is agreement on liquid precip as snow levels will be quite
high. Breezy southerly winds will keep the atmosphere somewhat
mixed overnight, keeping low temperatures at or above freezing for
most of the valleys. The exceptions will be across the extreme
northern valleys where winds will start to shift to the north and
colder, drier air will infiltrate the valleys. For Friday and into
the weekend, models start to fight again. The general trend will
be a cooldown as an arctic front slides south but timing and
southern extent of the very cold air is still being debated.
/Kelch
&&
.AVIATION...
18Z TAFS: Radar trends and 15z HRRR model show most of the shower
activity today will develop just east of KGEG/KSFF with light
rain and snow showers spanning from extreme northeast Washington,
north Idaho. Strong low level warm advection has raised both temps
and dewpoints, making the precipitation type mainly rain at the
TAF sites. Airports north of the metro like Bonners Ferry and
Colville may see a slushy runway accumulations up to an inch will
be possible. Gusty westerly winds will develop from KEAT to KMWH
this afternoon and evening. Dry/downslope advection from the
west/northwest this evening should disperse stratus in the
evening, but fog and low stratus may crop up toward Monday
morning from KPUW to KGEG and KSFF. /rfox
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 27 37 33 42 39 47 / 10 10 50 60 50 50
Coeur d`Alene 28 38 34 40 40 45 / 20 10 60 80 60 70
Pullman 30 41 37 47 44 50 / 20 10 60 90 50 30
Lewiston 34 47 40 52 46 54 / 20 10 60 60 30 20
Colville 23 36 31 39 36 42 / 10 10 50 70 70 50
Sandpoint 28 36 31 38 36 41 / 40 10 70 80 80 80
Kellogg 28 36 33 37 37 40 / 70 10 80 90 80 70
Moses Lake 25 41 33 46 41 52 / 10 0 20 30 10 20
Wenatchee 31 40 35 44 42 49 / 10 10 30 50 30 30
Omak 24 35 30 38 36 43 / 10 10 30 50 70 50
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Winter Weather Advisory until 6 AM PST Monday for Central
Panhandle Mountains.
WA...None.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS PORTLAND OR
1012 AM PST SUN NOV 23 2014
.SYNOPSIS...CONVECTIVE SHOWERS WILL CONTINUE OVER SW WASHINGTON AND
NW OREGON THROUGH THIS MORNING. THESE SHOWERS ARE ASSOCIATED WITH A
SLOW MOVING FRONT THAT WILL STALL OVER NW WASHINGTON BEFORE FALLING
A PART OVER NW OREGON THIS AFTERNOON. RAIN AND MOUNTAIN SNOW IS
EXPECTED FOR WASHINGTON THIS MORNING WITH LESS ACCUMULATIONS FOR
OREGON THIS AFTERNOON. A FLAT UPPER RIDGE WILL BUILD
INTO CALIFORNIA AND OREGON MONDAY AND TUESDAY...BUT SHOULD REMAIN
WEAK ENOUGH FOR SYSTEMS TO CLIP OUR NORTHERN ZONES WITH OCCASIONAL
WET WEATHER. VALLEY INVERSIONS WILL LIKELY BUILD IN THE CENTRAL AND
SOUTH WILLAMETTE VALLEY...WITH FOG POSSIBLY BECOMING MORE PERSISTENT
BY THE MIDDLE OF NEXT WEEK. ANOTHER ORGANIZED FRONT IS EXPECTED FOR
THE THANKSGIVING WEEKEND.
&&
.UPDATE...THE LONE OF CONVECTIVE SHOWERS OVER THE NORTHERN EDGE OF
THE PORTLAND FORECAST AREA IS MOVING SLOWLY SOUTHWARD. A FEW CELLS
ARE SPROUTING UP AHEAD OF THIS LINE. ONE IN PARTICULAR...JUST OFF OF
LONG BEACH WA HAD STRONG ROTATION SIGNATURES INDICATIVE OF A TORNADO
AND A TORNADO WARNING WAS ISSUED AS THE STORM TRACKED INLAND. THE
STORM FINALLY WEAKENED OVER NASELLE WA. WE HAVE RECEIVED NO
OBSERVATIONS NEAR THIS STORM TO VERIFY OR DENY THE PRESENCE OF A
TORNADO. ONE SPOTTER JUST NORTH OF LONG BEACH HAD PEA-SIZE HAIL AND
LIGHTNING AND DID NOT SEE THE ROTATION. HOWEVER...THE BEST VIEWING OF
ANY ROTATION WOULD BE SOUTH OF THE STORM...AND SOUTH OF LONG BEACH.
VERTICAL SHEAR IN THE ATMOSPHERE WILL CONTINUE A THREAT FOR WEAKLY
ORGANIZED STORMS THROUGH NOON TODAY. MOST OF THESE STORMS WILL BE
OVER THE WATERS...BUT THEY MAY OCCASIONAL MOVE ONSHORE. WE WILL BE
MONITORING RADAR CLOSELY THIS MORNING.
THE FRONT HAS PRODUCED .3 TO .5 INCHES OF RAIN IN THE PAST 3 HOURS
NORTH OF OUR AREA. THE HIGHER AMOUNTS ARE MOST LIKELY ASSOCIATED WITH
THE CONVECTIVE BAND. HOWEVER STILL THINK THE SW WASHINGTON CASCADES
WILL SEE SOME SNOW ACCUMULATIONS ABOVE 4000 FEET AND HAVE NOT MADE
ANY CHANGES TO THE WINTER WEATHER ADVISORY WITH THE UPDATE.
ELSEWHERE...EXPECT COOL AND RAINY CONDITIONS THROUGH THIS EVENING.
HIGH PRESSURE BEGINS TO BUILD OVER THE EASTERN PACIFIC LATE TONIGHT
INTO MONDAY...WHICH SHOULD KEEP THE REGION FAIRLY DRY BUT CLOUDY. BUT
THE THREAT FOR VALLEY FOG INCREASES...ESPECIALLY FOR THE CENTRAL AND
SOUTH WILLAMETTE VALLEY AS WELL AS THE CENTRAL COAST. MODELS HAVE
BEEN CONSISTENT IN SHOWING A FEW DISTURBANCES RIDING OVER THE RIDGE
AND BRINGING SOME PRECIP MAINLY TO THE FAR NORTHERN FORECAST ZONES BY
MONDAY EVENING. EXPECT THIS PATTERN OF NORTHERN SHOWERS WITH SOUTHERN
VALLEY AND COASTAL FOG TO CONTINUE THROUGH WEDNESDAY. TJ/27
.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY...OVERALL MODELS ARE
ATTEMPTING TO FLATTEN THE UPPER LEVEL RIDGE LATE WEDNESDAY. BUT ONCE
WE GET TO THANKSGIVING MORNING...MODEL SOLUTIONS VARY CONCERNING THE
NEXT PACIFIC FRONTAL SYSTEM APPROACHING THE REGION THANKSGIVING DAY.
THE 06Z GFS SHOWS A RATHER WELL-ORGANIZED FRONTAL BAND REACHING THE
SW WASHINGTON/NW OREGON COAST IN THE MORNING...WITH RAIN SPREADING
INLAND BY THE AFTERNOON...RIGHT IN TIME FOR THANKSGIVING DINNER. WILL
HAVE TO SEE WHAT THE 12Z ECMWF DOES WITH THIS SYSTEM...AND WHETHER OR
NOT IT MAINTAINS ITS LIGHTER RAIN/RIDGY SOLUTION. A MUCH
STRONGER AND WETTER SYSTEM LOOKS TO MOVE IN OVER THE WEEKEND WHICH
COULD POSE A THREAT TO TRAVELERS RETURNING AFTER THE THANKSGIVING
HOLIDAY. DETAILS AT THIS POINT ARE STILL UNKNOWN AND WILL BE REFINED
WITH FUTURE UPDATES. THE GOOD NEWS IS THAT TEMPERATURES IN THE
EXTENDED WILL BE AT OR ABOVE SEASONAL NORMALS. /64/27
&&
.AVIATION...CONDITIONS ARE PRIMARILY VFR ACROSS THE REGION THIS
MORNING. A FRONT ALONG THE WASHINGTON COAST AND OVER THE COASTAL
WATERS IS PRODUCING SIGNIFICANT LIGHTNING AND GUSTY WINDS. THE
FRONT IS FCST TO WEAKEN AS IT PUSHES INTO NORTHWEST OREGON LATER
THIS MORNING...BUT IT MAY ALLOW FOR A PERIOD OF MVFR CONDITIONS
AT KAST LATER THIS MORNING AND THE KPDX METRO TAF SITES TOWARDS
MIDDAY. THERE IS A CHANCE MVFR CONDITIONS MAY PERSIST TOWARDS 12Z
MONDAY FOR THE PORTLAND METRO TAF SITES. FARTHER SOUTH WHERE
CLEARING THIS EVENING WILL BE MORE LIKELY TO OCCUR...IFR
CONDITIONS MAY DEVELOP AT KEUG...KSLE AND EVEN KHIO TOWARDS 12Z
MONDAY.
KPDX AND APPROACHES...A POST FRONTAL SHOWERY AIR MASS WILL LEAD
TO PREDOMINANTLY VFR CONDITIONS TODAY. A BAND OF RAIN ASSOCIATED
WITH A DYING FRONT MAY TEMPORARILY REDUCE CIGS INTO MVFR AROUND
MIDDAY. THERE IS A CHANCE THESE CONDITIONS COULD PERSIST WELL
INTO SUNDAY NIGHT...OR PERHAPS DETERIORATE INTO HIGH END IFR
CONDITIONS...BUT CONFIDENCE IN THESE DETAILS IS LOW AT THIS POINT.
PYLE/NEUMAN
&&
.MARINE...A SLOW MOVING FRONT BROUGHT A BAND OF STRONG
THUNDERSTORMS INTO THE W WASHINGTON COASTAL WATERS THIS MORNING.
BASED ON SEVERAL REPORTS OF WINDS IN EXCESS OF 40 MPH WITH SOME OF
THESE STORMS FURTHER NORTH ALONG THE WASHINGTON COAST...DECIDED TO
ISSUE A SPECIAL MARINE WARNING FOR THE WATERS AS FAR SOUTH AS THE
COLUMBIA RIVER BAR. EXPECT PERIODIC GUSTS IN EXCESS OF 34 KT ALONG
WITH FREQUENT LIGHTNING IN SOME OF THE STRONGER STORMS.
OTHERWISE...EXPECT GUSTY WINDS TO CONTINUE OVER THE NORTHERN
COASTAL WATERS INTO EARLY THIS AFTERNOON. THEN WINDS DROP OFF
CONSIDERABLY LATER THIS AFTERNOON AS THE FRONT WEAKENS. SEAS IN
THE 12 TO 13 FT RANGE AT CURRENT WILL LIKELY PEAK IN THE MID TEENS
LATER TODAY BEFORE DECREASING TONIGHT INTO MONDAY.
A WEAK FRONT WILL PUSH INTO THE WATERS LATE MONDAY...BUT ASIDE
FROM SOME SMALL CRAFT ADVISORY LEVEL WIND GUSTS OF 25 KT...NOT
EXPECTING MUCH IMPACT. WINDS MAY STAY A BIT GUSTIER ACROSS THE
NORTHERN WATERS EARLY TO MID WEEK BEFORE A SLOW MOVING LOW PRESSURE
SYSTEM IMPACTS THE WATERS MID TO LATE NEXT WEEK. LOW END GALE FORCE
WIND GUSTS MIGHT BE SQUEEZED OUT OF THIS SYSTEM AT SOME POINT...BUT
THE SCENARIO DOES NOT LOOK ALL THAT PROMISING FOR A SOLID GALE
FORCE OR HIGHER WIND EVENT FOR THE WATERS. PYLE/NEUMAN
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...WINTER WEATHER ADVISORY UNTIL 10 PM PST THIS EVENING FOR SOUTH
WASHINGTON CASCADES.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 3 PM PST THIS AFTERNOON FOR
COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR OUT
60 NM.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 9 AM PST MONDAY
FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT
60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 9 AM
PST MONDAY.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
Area Forecast Discussion
National Weather Service Spokane WA
938 AM PST SUN NOV 23 2014
.SYNOPSIS...
The mountains will receive another round of accumulating snow
this afternoon and evening. Most of the lower elevations will
experience light rain, but some wet snow is possible in the far
northern valleys. Monday will be a relatively quiet and chilly
day. More rain and heavy mountain snow is expected Monday night
into Tuesday. A breezy and wet weather pattern will persist for
much of the week with the mountains receiving several rounds of
snow.
&&
.DISCUSSION...
Updated the forecast on snow levels and temperatures this morning.
The incoming weather system seems to have slowed slightly,
meanwhile overnight lows were not as cool due to the thicking
clouds. The delayed arrival of the the precipitation has allowed
both temps and dewpoints to rise slightly and makes the
precipitation type a little tricky. But along and south of a line
south of Coeur d`Alene, Spokane, Ephrata and Wenatchee, expect
mostly rain as wetbulbs are above freezing. Expect snow at the
onset north of this line with accumulations of 1 to 2 inches.
Although increased southerly flow will allow valley temperatures
to rise this afternoon and lead to valley rain and mountain snow
across the north. /rfox
&&
.AVIATION...
18Z TAFS: Radar trends and 15z HRRR model show most of the shower
activity today will develop just east of KGEG/KSFF with light
rain and snow showers spanning from extreme northeast Washington,
north Idaho. Strong low level warm advection has raised both temps
and dewpoints, making the precipitation type mainly rain at the
TAF sites. Airports north of the metro like Bonners Ferry and
Colville may see a slushy runway accumulations up to an inch will
be possible. Gusty westerly winds will develop from KEAT to KMWH
this afternoon and evening. Dry/downslope advection from the
west/northwest this evening should disperse stratus in the
evening, but fog and low stratus may crop up toward Monday
morning from KPUW to KGEG and KSFF. /rfox
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 38 27 36 32 43 38 / 90 20 10 50 60 40
Coeur d`Alene 38 28 37 33 41 39 / 100 40 10 60 80 60
Pullman 41 29 40 36 46 42 / 80 60 10 60 70 30
Lewiston 50 33 47 39 50 44 / 50 60 10 60 60 20
Colville 36 25 35 30 39 36 / 90 10 10 60 60 50
Sandpoint 36 29 36 30 39 37 / 100 40 10 70 80 80
Kellogg 40 28 36 33 38 38 / 100 80 10 70 90 70
Moses Lake 46 25 40 32 48 40 / 20 10 10 20 20 10
Wenatchee 48 29 37 34 46 41 / 10 10 10 20 30 20
Omak 37 22 33 30 41 36 / 30 10 10 30 40 50
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Winter Weather Advisory until 6 AM PST Monday for Central
Panhandle Mountains.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
247 PM CST SUN NOV 23 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 247 PM CST SUN NOV 23 2014
COMPLEX SHORT TERM PERIOD WITH MANY ISSUES TO DEAL WITH.
CURRENTLY AS OF 21Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED A VERY ACTIVE PATTERN OVER THE WEST HALF OF THE COUNTRY.
UPPER LOWS WERE PRESENT OVER NORTHERN MISSISSIPPI AND NORTH
DAKOTA...WHILE POTENT SHORTWAVES WERE NOTED IN SOUTHWEST OKLAHOMA...
NORTHERN NEW MEXICO AND OVER WASHINGTON STATE. THE FORECAST AREA
LIES IN SOUTHWEST FLOW...WHERE WATER VAPOR IMAGERY SHOWS A NICE WARM
CONVEYOR BELT OVER THE EAST HALF OF THE AREA. THIS TRANSLATES TO A
BAND OF RAIN FROM EASTERN IA THROUGH SOUTHWEST WI TO THE GRB AREA.
RAP PRECIPITABLE WATER VALUES ARE AROUND 1 INCH ALONG AND SOUTH OF
THE BAND...COMPARED TO 0.75 INCHES OVER OUR NORTHWEST CWA WHERE
CONDITIONS ARE DRY. ALTHOUGH ITS DRIER IN PRECIPITABLE WATER...
DRIZZLE AND/OR LIGHT RAIN HAS BEEN PRESENT DUE TO SATURATED LOW
LEVELS AND WEAK ISENTROPIC LIFT ON THE 285-290K SURFACES. TO THE
WEST...A COLD FRONT WAS PRESENT ALONG I-35 WITH A WEAKENING BAND OF
RAIN RIGHT BEHIND IT...ASSOCIATED WITH MID LEVEL FRONTOGENESIS.
TEMPERATURES AHEAD OF THE FRONT ACROSS THE FORECAST AREA WERE MAINLY
IN THE 40S TO LOW 50S...COLDEST OVER THE DEEPER SNOWPACK IN TAYLOR
COUNTY. IN THE WAKE OF THE FRONT...READINGS WERE IN THE 30S AND
40S...UNTIL ONE GETS INTO NORTH DAKOTA BEHIND A SECONDARY COLD FRONT
WHERE READINGS ARE IN THE TEENS AND 20S. LAST ITEM OF NOTE IS THE
SEA LEVEL PRESSURE MAP WHERE A LOW EXISTS NEAR MEMPHIS ON THE NORTH
SIDE OF THE UPPER LOW THERE...ANOTHER LOW WAS OVER NORTHERN MN
AHEAD OF THE NORTH DAKOTA UPPER LOW...AND FINALLY A THIRD LOW WAS
OVER NORTHEAST OKLAHOMA AHEAD OF THE POTENT SHORTWAVES.
MODEL WISE...THERE ARE STILL SOME DIFFERENCES THAT HAVE SIGNIFICANT
FORECAST IMPLICATIONS. MUCH OF THE DIFFERENCES WE HAVE SEEN LATELY
THAT CONTINUE INTO TODAY REVOLVE AROUND HANDLING THOSE POTENT
SHORTWAVES IN SOUTHWEST OKLAHOMA AND NORTHERN NEW MEXICO. THE
STRONGER SURFACE LOW SCENARIOS THAT WOULD IMPACT THE FORECAST AREA
WITH MORE SNOW...LIKE OBSERVED IN THE 23.00Z NAM...BROUGHT THESE
SHORTWAVES INTO NORTHERN IL BY 12Z MONDAY. THOSE SHORTWAVE TRACKS
ALSO SHOWED IN A COUPLED UPPER JET STRUCTURE WITH ANOTHER JET STREAK
OVER ONTARIO AND LAKE SUPERIOR. HOWEVER...THE 23.12Z
NAM/GFS/CANADIAN/ECMWF SUGGEST THESE SHORTWAVES WILL TRACK THROUGH
CENTRAL IL. SO WHAT HAPPENS INSTEAD IS A DOUBLE SURFACE LOW...ONE
ASSOCIATED WITH THE NORTHERN MISSISSIPPI UPPER LOW LIFTING THROUGH
LOWER MI AND A SECOND LOW LIFTING TROUGH NORTHERN IL AT 12Z MONDAY.
WITH THE POTENT SHORTWAVES. THERE STILL ARE THE 2 JET STREAKS...BUT
THEY ARE FAR ENOUGH APART TO PREVENT COUPLING AND THUS PREVENTING A
SINGLE SURFACE LOW. THIS FORECAST LEANS TOWARDS THIS NEWER MODEL
GROUP. EVEN THIS GROUP HAS DIFFERENCES...PRIMARILY WITH THE CANADIAN
PRODUCING A LOT MORE SNOW ON MONDAY AROUND AND EAST OF THE
MISSISSIPPI RIVER.
FOR TONIGHT...THE WARM CONVEYOR BELT / FRONTOGENESIS BAND PRODUCING
THE ONGOING RAIN OVER THE SOUTHEAST HALF OF THE FORECAST AREA
REMAINS POISED TO SHIFT EASTWARD THROUGH THE EVENING. THIS EASTWARD
MOVEMENT IS DUE TO THE UPPER AND SURFACE LOWS NEAR THE MEMPHIS AREA
LIFTING INTO LOWER MICHIGAN. HOWEVER...DRIZZLE AND/OR LIGHT RAIN
SHOULD CONTINUE ELSEWHERE AS SOUNDINGS DEPICT PLENTIFUL LOW TO MID
LEVEL VERTICAL MOTION AND SATURATION...SIMILAR TO WHAT IS GOING ON
NOW. ADDITIONALLY...THAT WEAKENING BAND OF MID-LEVEL FRONTOGENESIS
SEEN ALONG I-35 IS POISED TO GRADUALLY CROSS THE FORECAST AREA WITH
THE SURFACE COLD FRONT...AIDING IN PRECIPITATION GENERATION. IT MAY
NOT BE UNTIL 09Z FOR THE FAR WESTERN FORECAST AREA TO SEE AN END TO
THE PRECIPITATION. NOTE THE TYPE SHOULD BEGIN TO CHANGE OVER TO SNOW
AS COLDER AIR IN THE DAKOTAS GETS PULLED INTO THE FORECAST AREA. ANY
ACCUMULATIONS TONIGHT SHOULD BE VERY LIGHT...DUE TO LATE CHANGE-OVER
TIME AND WARM GROUND...AND CONFINED TO MOSTLY WEST OF THE
MISSISSIPPI RIVER.
FOR MONDAY...ATTENTION FOCUSES ON THE LOW AND POTENT SHORTWAVES
LIFTING THROUGH ILLINOIS AT 12Z MONDAY. THERE IS A STRONG CONSENSUS
FOR PRECIPITATION IN THE WAKE OF THE LOW...CORRELATED WITH A LEFT
EXIT REGION OF A JET STREAK COMING INTO THE OHIO VALLEY.
ADDITIONALLY...A STRONG POCKET OF MID LEVEL FRONTOGENESIS WITH
NEGATIVE EPV ABOVE FOLLOWS IN THE WAKE OF THE LOW. THAT
FRONTOGENESIS STRENGTHENS AS THE COLD AIR FROM THE DAKOTAS MEETS UP
WITH THE POTENT SHORTWAVES LIFTING NORTHEASTWARD...ALSO CAUSING A
SWITCHOVER TO SNOW. CONSENSUS...OUTSIDE OF THE CANADIAN...SUGGESTS
THE HEAVIER SNOW TRACKING THROUGH NORTHERN IL AND SOUTHERN
WI...CLIPPING GRANT AND RICHLAND COUNTIES...POSSIBLY JUNEAU AND
ADAMS TOO. BOTH SNOWFALL AMOUNTS AND BLOWING POTENTIAL ARE GOING TO
BE KEPT DOWN QUITE A BIT WITH SOUNDINGS DEPICTING A DEEP AGGREGATION
LAYER AND ONLY 50 MB OR SO OF DENDRITIC GROWTH ZONE. ADDITIONALLY...
WARM GROUND AND LACK OF SNOW WILL HELP LIMIT BLOWING. IN
COLLABORATION WITH MKX AND DVN...HAVE ISSUED A WINTER WEATHER
ADVISORY FOR GRANT AND RICHLAND. ELSEWHERE...THERE SHOULD STILL BE
SOME LIGHTER SNOW WITH A WEAKER MID LEVEL FRONTOGENESIS ZONE
MARCHING WEST TO EAST...AND DEEP SATURATION. AMOUNTS DO NOT WARRANT
AN ADVISORY ELSEWHERE AT THIS TIME.
IN THE FOG DEPARTMENT...CONDITIONS HAVE YET TO IMPROVE ACROSS
TAYLOR/CLARK COUNTIES. HI RES MODEL VISIBILITY PROGS...WHICH
ARE HANDLING THE FOG THERE WELL...DO NOT SHOW ANY CLEARING UP UNTIL
THE 06-09Z PERIOD WHEN WINDS START TO INCREASE. THEREFORE...HAVE
EXTENDED THE ADVISORY UNTIL 06Z. VISIBILITIES HAVE ALSO BEEN LOW
OVER THE FAR WESTERN FORECAST AREA...THOUGH THESE SHOULD IMPROVE
SOON AS THE WINDS PICK UP. WILL NEED TO KEEP AN EYE ON VISIBILITIES
THROUGH NORTHEAST IOWA AND SOUTHWEST/CENTRAL WI AS THE HEAVIER RAIN
MOVES OUT...WITH SOME SIGNAL THEY COULD DROP TO WARRANT AN ADVISORY.
LASTLY...REGARDING WINDS...SHOULD SEE SUSTAINED SPEEDS OF 15-30 MPH
WITH GUSTS MAYBE UP TO 40 MPH ON MONDAY. DO NOT SEE ANY WIND
ADVISORY NEED AT THIS TIME...THOUGH. THESE NORTHWEST WINDS WILL
RESULT IN A FALLING TEMPERATURE TREND FROM NOW THROUGH MONDAY.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 247 PM CST SUN NOV 23 2014
NO MATTER WHAT SOLUTION PANS OUT FOR MONDAY...THE TREND CONTINUES TO
BE FOR SNOW TO DIMINISH MONDAY NIGHT AS THE ENTIRE STORM SYSTEM
EXITS EASTWARD INTO QUEBEC. THERE IS SOME UNCERTAINTY ON HOW QUICK
THE SNOW EXITS...MAINLY DUE TO ONE MORE WEAK SHORTWAVE PASSING. WITH
STRATUS LINGERING IN THE DENDRITIC GROWTH ZONE...IT MAKES SENSE TO
CONTINUE TO CARRY PRECIPITATION CHANCES LONGER TOO THAN WHAT MODEL
QPF WOULD SAY FOR ENDING SNOW. BETTER CHANCE FOR CLEARING COMES IN
TUESDAY AS A SURGE OF DRIER...SUBSIDENT AIR COMES IN AHEAD OF A
SURFACE LOW AND SHORTWAVE DROPPING THROUGH THE DAKOTAS. IN FACT...WE
SHOULD GET INTO A WARM ADVECTION REGIME LATER IN THE DAY TO ALLOW
TEMPERATURES TO CLIMB INTO THE MID TO UPPER 20S.
THE SHORTWAVE TROUGH AND SURFACE LOW DROPPING THROUGH THE DAKOTAS
FOR TUESDAY NIGHT AND WEDNESDAY HAS BEEN TRENDING SOUTHWARD IN THE
23.12Z ECMWF...FOLLOWING THE 23.06Z/12Z GFS/NAM. THE 23.12Z CANADIAN
IS ABOUT THE ONLY MODEL NOW WITH THE MORE NORTHERN TRACK. HAVE
ADJUSTED THE FORECAST FOR A MORE SOUTHERN TRACK. DPVA PLUS A SURGE
OF WARM AIR ADVECTION LOOKS TO RESULTS IN A BRIEF BUT HEAVY SNOW
BAND AHEAD OF THE SURFACE LOW. WITH THE SOUTHERN TREND BUT OVERALL
GOOD CONSENSUS TO HAVE THE SNOW BAND...RAISED CHANCES ON WEDNESDAY
TO 60 ACROSS THE SOUTHERN PORTION OF THE FORECAST AREA. MAY GET A
QUICK 1-2 INCHES OUT OF THE BAND...ENOUGH TO IMPACT TRAVEL.
A DRIER BUT COLDER FORECAST IS ON TAP FOR WEDNESDAY NIGHT AND
THANKSGIVING AS ARCTIC HIGH PRESSURE BUILDS INTO THE REGION. 925MB
TEMPS DOWN TO -12 TO -16C SHOULD RESULT IN HIGHS IN THE TEENS TO
MAYBE 20 AT BEST.
THE FORECAST AFTER THANKSGIVING BECAME MUCH MORE UNCERTAIN
TODAY. THERE ARE NOW INDICATIONS OF MORE TROUGHING DIGGING DOWN
THROUGH BRITISH COLUMBIA...WHICH HELPS TO TURN THE UPPER FLOW MORE
ZONAL...AND THUS SEND A WARMER PACIFIC AIRMASS TOWARDS US.
ADDITIONALLY...A WARM FRONT LOOKS TO MOVE THROUGH THE AREA ON
FRIDAY...WHICH COULD PRODUCE A LITTLE SNOW. NOW...THE 23.12Z
GFS/CANADIAN DRIVE A SHORTWAVE THROUGH THE REGION FRIDAY NIGHT AND
ALLOWS ARCTIC AIR TO RETURN FOR THE WEEKEND. THE 23.12Z ECMWF ALLOWS
THIS SHORTWAVE TO STAY FARTHER NORTH...KEEPING THE AREA IN THE WARM
SECTOR. FOR NOW...HAVE STAYED WITH THE CONSENSUS PRIOR TO THE NEW
ECMWF ARRIVAL...BUT THE WEEKEND TEMPS ARE DEFINITELY SUBJECT TO
CHANGE GREATLY. GENERALLY THE WEEKEND LOOKS DRY...THOUGH.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1225 PM CST SUN NOV 23 2014
LIFR /IFR/ CONDITIONS ARE EXPECTED TO CONTINUE AT KRST /KLSE/
THROUGH THE AFTERNOON UNTIL A COLD FRONT PROVIDES A WIND SHIFT AT
KRST LATER THIS AFTERNOON. CURRENTLY THIS FRONT HAS VFR CONDITONS
BEHIND IT...HOWEVER ABUNDANT LOW-LEVEL MOISTURE AND SUNSET SUGGEST
THAT IF THERE IS A BREAK IN THE LIFR CONDITIONS AT THE TAF SITES...IT
WILL BUILD BACK IN FOR THE OVERNIGHT WITH COOLING. A CHANGE FROM
RAIN TO SNOW THEN OCCURS LATER OVERNIGHT...WITH DEEPER MIXING AND
STRONGER WINDS MOVING IN BY DAYBREAK. THIS MIXING WILL HELP
FINALLY REMOVE THE LIFR/IFR CONDITIONS...IF THEY HAVE NOT LIFTED
ACROSS THE AREA. STRONG WINDS ARE EXPECTED MONDAY AND POSSIBLY
FLURRIES.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY FROM 6 AM MONDAY TO MIDNIGHT CST MONDAY
NIGHT FOR WIZ055-061.
DENSE FOG ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR WIZ017-029.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...BAUMGARDT
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
244 PM MST SUN NOV 23 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 300 PM MST SUN NOV 23 2014
MODELS IN GOOD AGREEMENT THROUGH TUESDAY...WITH WINDS AND HIGH
ELEVATION SNOWS THE PRIMARY FORECAST CONCERN OVER THE NEXT 48 TO
60 HOURS. FOR TONIGHT AND MONDAY...KEPT THE WIND ADVISORY GOING
FOR THE NEXT FEW HOURS WITH WINDS GUSTING TO 50 MPH ACROSS THE
WESTERN NEBRASKA PANHANDLE. THESE WINDS WILL DIMINISH AROUND
SUNSET WITH BREEZY CONDITIONS EXPECTED THROUGH MIDNIGHT. THE
MOUNTAIN SNOWFALL CONTINUING ACROSS THE REGION TODAY...AND SNOTEL
SITES REPORTING OVER ONE FOOT STORM TOTAL SNOW ALREADY...THE
WINTER STORM WARNING LOOKS GOOD AS WELL THROUGH MONDAY. DID ADJUST
SNOW ACCUMULATIONS A BIT ACROSS THE HIGHER RIDGES SINCE A FEW
PLACES MAY SEE CLOSE TO 30 INCHES BY LATE MONDAY. ADDED BLOWING
SNOW TO THE MOUNTAINS AND SURROUNDING VALLEYS INTO MONDAY AS THE
NEXT UPPER LEVEL DISTURBANCE MOVES INTO WYOMING LATE TONIGHT.
AFTER A BRIEF LULL IN THE SNOWFALL RATES THIS EVENING...SNOW
INTENSITY WILL QUICKLY INCREASE AFTER MIDNIGHT WITH AN ADDITIONAL
6 TO 12 INCHES EXPECTED THROUGH MONDAY AFTERNOON.
THE MAIN FORECAST CHALLENGE WILL BE TONIGHT AND THEN AGAIN ON
TUESDAY WITH STRONG WINDS ACROSS PORTIONS OF SOUTHEAST WYOMING.
THE NEXT UPPER LEVEL DISTURBANCE...CURRENTLY PUSHING SOUTHEAST
ACROSS IDAHO AND WESTERN MONTANA...WILL MOVE INTO WYOMING LATE
TONIGHT. LLVL WINDS WILL SHIFT INTO THE WEST BY MIDNIGHT AND
GRADUALLY INCREASE DUE TO A STRENGTHENING PRESSURE GRADIENT ALONG
THE CONTINENTAL DIVIDE AND THE LARAMIE RANGE. WIND GUSTS OVER 58
MPH ARE POSSIBLE OVER THE WIND PRONE AREAS ALONG I80.
THEREFORE...ISSUED A HIGH WIND WATCH FOR THE ARLINGTON AREA AND
THE I80 SUMMIT BETWEEN CHEYENNE AND LARAMIE. DO NOT BELIEVE I25
WILL SEE THE STRONGEST WINDS THIS TIME AROUND SINCE MODELS SHOW
SURFACE PRESSURE REMAINING STEADY OR INCREASING SLIGHTLY ACROSS
THE HIGH PLAINS. MODELS DO INDICATE PRESSURE FALLS FURTHER SOUTH
ACROSS NORTHERN COLORADO...SO EXPECT THE SOUTHERN LARAMIE RANGE TO
RECEIVE THE HIGHER GUSTS THIS TIME AROUND. OTHERWISE...EXPECT
ANOTHER ROUND OF ISOLATED TO SCATTERED SNOW SHOWERS ACROSS THE
VALLEYS AND HIGH PLAINS ON MONDAY AS THIS DISTURBANCE MOVES ACROSS
THE AREA AND INTO COLORADO.
FOR TUESDAY...A MORE WIDESPREAD HIGH WIND EVENT IS POSSIBLE AS A
140 KNOT JET MAX PUSHES ACROSS THE AREA WHILE THE JET STREAM
ITSELF TRANSLATES NORTHEASTWARD INTO TUESDAY NIGHT. MAY NEED A
HIGH WIND WATCH FOR MOST OF SOUTHEAST WYOMING ON TUESDAY ALONG
WITH WIND ADVISORIES ACROSS WESTERN NEBRASKA. THERE IS HIGH
CONFIDENCE THAT THE WIND PRONE AREAS WILL SEE GUSTS OVER 60 MPH BY
EARLY TUESDAY MORNING.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 300 PM MST SUN NOV 23 2014
WINDS ARE THE PRIMARY FORECAST CHALLENGE IN THE LONG
TERM...FOLLOWED BY TEMPERATURES LATE IN THE EXTENDED. NOT A GOOD
TRAVEL TIME TUESDAY NIGHT THROUGH WEDNESDAY ACROSS SOUTHEAST
WYOMING AHEAD OF THE THANKSGIVING HOLIDAY.
STARTING OFF TUESDAY EVENING...GOING TO BE REALLY WINDY ACROSS
SOUTHEAST WYOMING. GFS 700MB WINDS 75 TO 80KTS ACROSS SOUTHERN
ALBANY COUNTY AND THE SOUTH LARAMIE RANGE. ECMWF 700MB WINDS A
BIT LOWER...BUT STILL IN THE 50 TO 60KT RANGE...SO CHANCES ARE
STILL REALLY GOOD FOR HIGH WIND HIGHLIGHTS AT LEAST FOR OUR WIND
PRONE AREAS CONTINUING INTO TUESDAY NIGHT AND WEDNESDAY MORNING.
LATEST WRKHGT PRODUCT ENDS AT 00Z WEDNESDAY...BUT STILL SHOWS BOTH
850 AND 700MB CRAIG TO CASPER HEIGHT GRADIENTS WELL ABOVE 60MTRS.
ANOTHER UNCERTAINTY IN TUESDAY NIGHTS FORECAST...GFS SETS UP A
FAIRLY ROBUST BAND OF PRECIP OVER THE LARAMIE RANGE. COULD BE DUE
TO UPSLOPING OF NORTHWEST WINDS ON THE WEST SIDE OF THE LARAMIE
RANGE ALONG THE FRONTAL BOUNDARY THATS GOING TO LAY IN THE AREA.
ECMWF MUCH LESS ON QPF AMOUNTS. WE ARE GOING TO NEED TO WATCH THIS
DEVELOPMENT. SHOULD THE GFS SOLUTION COME TRUE...THIS SNOW
COMBINED WITH THE VERY STRONG WINDS WILL CREATE BLIZZARD
CONDITIONS FOR THE SOUTH LARAMIE RANGE OVER TO PROBABLY ARLINGTON
OR SO TUESDAY NIGHT INTO WEDNESDAY. DID ADD AREAS OF BLOWING SNOW
INTO THE FORECAST WEATHER GRIDS FOR THAT TIMEFRAME. LATER SHIFTS
WILL NEED TO DETERMINE WHAT WINTER HEADLINES TO ISSUE.
BOTH THE GFS AND ECMWF LIFT THE FRONTAL BOUNDARY NORTHEAST INTO
THE FAR NORTHERN NEBRASKA PANHANDLE BY WEDNESDAY AFTERNOON. WINDY
CONDITIONS WEST OF THE LARAMIE RANGE TO CONTINUE AS BOTH THE GFS
AND ECMWF SHOW 700MB WINDS WELL ABOVE 50KTS.
FOR THANKSGIVING...IT LOOKS DRY ACROSS SOUTHEAST WYOMING AND
NEBRASKA PANHANDLE. CONTINUED WINDY...BUT NOTHING NEAR WHAT WE
WILL SEE TUESDAY AND WEDNESDAY. WIND PRONE AREAS COULD STILL BE
FLIRTING WITH HIGH WIND CRITERIA...ESPECIALLY OUT BY ARLINGTON ON
INTERSTATE 80. FAIRLY WARM THURSDAY AFTERNOON WITH LOW TO MID 40S
COMMON.
STRONG WINDS LOOK TO RETURN FRIDAY INTO SATURDAY AS ANOTHER
FRONTAL BOUNDARY BEGINS TO SAG SOUTH OUT OF MONTANA. GFS MUCH
FASTER ON THE SOUTHERN MOVEMENT OF THIS BOUNDARY...DRIVING THE
FRONT INTO THE EAST SLOPES OF THE LARAMIE RANGE BY SATURDAY
MORNING. ECMWF HAS FRONT STILL UP OVER NORTHERN WYOMING BY 12Z
SATURDAY. SO WE COULD BE LOOKING AT A 15 TO 20 DEGREE TEMPERATURE
BUST DEPENDING ON WHICH SOLUTION PANS OUT. DID LOWER HIGH
TEMPERATURES SATURDAY SEVERAL DEGREES ACROSS THE PANHANDLE AND
EASTERN SECTIONS OF SOUTHEAST WYOMING AS A HEDGE FOR NOW.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 948 AM MST SUN NOV 23 2014
LATEST HRRR FORECAST USED FOR THE 18Z TAFS. SOME CONCERN FOR SOME
CONVECTIVE SNOW SHOWERS FOR KRWL AND KLAR AS SEEN IN THE HRRR
SOLUTION. BUT THESE BANDS ARE VERY NARROW AND IT WOULD BE ALMOST
IMPOSSIBLE TO NAIL DOWN TIMING OF THESE BANDS. DO BELIEVE MOST OF
THE SNOW SHOWERS WILL STAY SOUTH OF KLAR AND KRWL THIS
AFTERNOON...SO KEPT LOWER CONDITIONS OUT OF THE TAFS FOR BOTH
SITES. WILL CONTINUE TO MONITOR.
&&
.FIRE WEATHER...
ISSUED AT 110 PM MST SUN NOV 23 2014
ALTHOUGH WINDS WILL BE STRONG EARLY THIS WEEK...NO FIRE WEATHER
CONCERNS ARE ANTICIPATED DUE TO COOL TEMPERATURES AND HIGH
RELATIVE HUMIDITIES.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WARNING UNTIL 5 PM MST MONDAY FOR WYZ112-114.
HIGH WIND WATCH FROM MIDNIGHT MST TONIGHT THROUGH MONDAY MORNING
FOR WYZ110-116.
NE...WIND ADVISORY UNTIL 6 PM MST THIS EVENING FOR NEZ002-003-019>021-
054-055-095-096.
&&
$$
SHORT TERM...TJT
LONG TERM...GCC
AVIATION...GCC
FIRE WEATHER...TJT
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
952 AM MST SUN NOV 23 2014
.SHORT TERM...(TODAY THROUGH MONDAY NIGHT)
ISSUED AT 300 PM MST SAT NOV 22 2014
TODAY...MOIST NORTHWEST FLOW ALOFT CONTINUES TODAY WITH A FEW WEAK
SHORTWAVE TROUGHS IN THE FLOW. COLD AIR ADVECTION IN EARNEST TODAY
WITH PLENTY OF LOW AND MID LEVEL MOISTURE BEING ADVECTED ACROSS THE
SNOWY AND SIERRA MADRE RANGES...PRODUCING WIDESPREAD LIGHT
SNOW...AND THUS WE WILL CONTINUE THE WINTER STORM WARNING THERE. FOR
THE WESTERN NEBRASKA PANHANDLE...PROGGED GRADIENTS SUGGEST WIND
ADVISORY CRITERIA FROM LATE THIS MORNING THROUGH THIS AFTERNOON.
TONIGHT...MOIST NORTHWEST FLOW ALOFT CONTINUES PRODUCING OROGRAPHIC
SNOW SHOWERE ACROSS THE MOUNTAINS.
MONDAY...PROGRESSIVE LOW AMPLITUDE POSITIVELY TILTED SHORTWAVE MOVES
ACROSS OUR COUNTIES ON NORTHWEST FLOW ALOFT. MODERATE TO HEAVY
OROGRAPHIC SNOWS WILL CONTINUE ACROSS THE SNOWY AND SIERRA MADRE
RANGES IN FLOW ALOFT...DRY ELSEWHERE...EXCEPT FOR ISOLATED SHOWERS
OVER THE PLAINS.
MONDAY NIGHT...FAST NORTHWEST FLOW ALOFT CONTINUES. DECENT SURFACE
LEE TROUGH EXPECTED TO SCOUR THE COLD AIR OUT TO OUR EAST.
.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 300 PM MST SAT NOV 22 2014
TUESDAY THROUGH SATURDAY...NORTH/NORTHWEST FLOW EARLY IN THE PERIOD
WILL FLATTEN AND BECOME MORE ZONAL BY THE END OF THE WEEK AND NEXT
WEEKEND. 00Z MEDIUM RANGE SOLUTIONS ARE SIMILAR AT LEAST FOR TUESDAY
AND WEDNESDAY...BUT CONTINUE THEIR MASSIVE DISCREPENCIES THEREAFTER.
MORE ON THAT LATER. LETS TALK ABOUT THE PART OF THE FORECAST THAT
CARRIES THE GREATEST CONFIDENCE...TUESDAY AND WEDNESDAY.
NORTH/NORTHWEST FLOW WILL BE IN PLACE WITH WITH THE NOSE OF AN 160+
KNOT H3 JET MOVING OVERHEAD. TIGHT LLVL PRESSURE/HEIGHT GRADIENT AND
PROGD H7 WINDS OF OF 60-70 KNOTS WILL MAKE TUESDAY ANOTHER WIND DAY.
WILL UNDOUBTEDLY NEED WIND HIGHLIGHTS IN TIME ON TUESDAY ESPECIALLY
IN WIND PRONE AREAS. WIND SPEEDS OUTSIDE OF THESE AREAS WILL DEPEND
ON THE AMOUNT OF LENTICULAR CLOUD COVER AND CORRESPONDING MIXING.
OROGRAPHIC SNOWS WILL BE A NEAR CERTAINTY ON TUESDAY AFTERNOON AS
MOISTURE ADVECTION COMBINES WITH ACCELERATING LLVL FLOW. ANOTHER 4
TO 8 INCHES OF SNOW WILL BE POSSIBLE OVR THE SNOWY AND SIERRA MADRES
TUESDAY AND TUESDAY NIGHT. WILL UNDOUBTEDLY NEED ANOTHER WINTER
HEADLINE OVR THE SNOWY/SIERRA MADRE RANGES TUESDAY AND TUESDAY
NIGHT. TUESDAY WILL BE ABOUT 5 DEGREES MORE MILD AS WELL. FLOW
BECOMES MORE NORTHWEST ON WEDNESDAY...AS THE JET TRANSLATES EAST AND
BEGINS FLATTENING. OROGRAPHIC SNOW WILL DIMINISH ON WEDNESDAY AS
MOISTURE/LIFT DEPART.
AND NOW FOR THE UNCERTAINTY THAT CONTINUES FOR THANKSGIVING. IF YOU
RECALL MODEL SOLUTIONS FROM 24 HOURS SHOWED A COOLER/WETTER GFS
COMPARED TO MILD AND DRY ECMWF. WELL TONIGHTS RUNS HAVE COMPLETELY
FLIP FLOPED. NOW THE ECMWF SHOWS THE ARCTIC AIR MASS BACKING IN
EARLY THURSDAY AND SNOW DEVELOPING THURSDAY NIGHT AND FRIDAY.
COMPARATIVELY...THE GFS IS DRY AND SIGNIFICANTLY WARMER THRU THE
PERIOD. TO ILLUSTRATE THE UNCERTAINTY FURTHER...GFS MOS FORECASTS A
HIGH TEMPERATURE OF 63F FOR THANKSGIVING...WHILE THE ECMWF PROGS
34F. NEEDLESS TO SAY FORECAST CONFIDENCE REMAINS UNUSUALLY LOW FOR
THANKSGIVING AND FRIDAY. FOR NOW HAVE STEERED THE FORECAST TOWARDS A
COMPROMISE OF THE TWO FOR THANKSGIVING AND KEPT THINGS DRY. IN
EITHER CASE...COLD AIR RETREATS FOR THE WEEKEND AS THE PATTERN
BECOMES MORE ZONAL. STAY TUNED OVER THE NEXT FEW DAYS AS THE MODELS
HOPEFULLY GET A BETTER HANDLE ON THE HOLIDAY TIME PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 948 AM MST SUN NOV 23 2014
LATEST HRRR FORECAST USED FOR THE 18Z TAFS. SOME CONCERN FOR SOME
CONVECTIVE SNOW SHOWERS FOR KRWL AND KLAR AS SEEN IN THE HRRR
SOLUTION. BUT THESE BANDS ARE VERY NARROW AND IT WOULD BE ALMOST
IMPOSSIBLE TO NAIL DOWN TIMING OF THESE BANDS. DO BELIEVE MOST OF
THE SNOW SHOWERS WILL STAY SOUTH OF KLAR AND KRWL THIS
AFTERNOON...SO KEPT LOWER CONDITIONS OUT OF THE TAFS FOR BOTH
SITES. WILL CONTINUE TO MONITOR.
&&
.FIRE WEATHER...
ISSUED AT 209 PM MST SAT NOV 22 2014
MINIMAL CONCERNS DUE TO PROJECTED HUMIDITIES AND WINDS.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WARNING UNTIL 5 PM MST MONDAY FOR WYZ112-114.
NE...WIND ADVISORY UNTIL 6 PM MST THIS EVENING FOR NEZ002-003-019>021-
054-055-095-096.
&&
$$
SHORT TERM...RUBIN
LONG TERM...CAH
AVIATION...GCC
FIRE WEATHER...RUBIN