Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 12/08/14
AREA FORECAST DISCUSSION
NWS TUCSON AZ
212 AM MST SAT DEC 6 2014
.SYNOPSIS...ANOTHER WEATHER SYSTEM FROM THE EASTERN PACIFIC WILL
BRING A FEW SHOWERS TO THE AREA TODAY. OTHERWISE...EXPECT NEAR TO
ABOVE AVERAGE TEMPERATURES INTO NEXT WEEK WITH DRY CONDITIONS.
&&
.DISCUSSION...A WEATHER SYSTEM FROM THE EASTERN PACIFIC WILL TRACK
THROUGH THE WESTERN STATES TODAY. THE TAIL END OF THIS SYSTEM WAS
PROGGED TO PASS THROUGH SOUTHERN ARIZONA WITH LIMITED MOISTURE THIS
FAR SOUTH. THE NAM AND HRRR MODELS WERE REALLY THE ONLY SOLUTIONS
THAT SUGGESTED MEASURABLE PRECIPITATION WITH THE LATEST SREF SHOWING
THE BEST CHANCES ACROSS THE RIM COUNTRY AND MOUNTAINS. THUS...HAVE
DECIDED TO DECREASE PRECIPITATION CHANCES ACROSS MOST OF SOUTHEAST
ARIZONA FOR TODAY. OTHERWISE...MODELS SHOWED A SHORTWAVE RIDGE
BUILDING OVER THE DESERT SOUTHWEST SUNDAY AND MONDAY...THEN
FLATTENING A BIT TUESDAY AS A WEAK SYSTEM PASSES THROUGH THE CENTRAL
ROCKIES. MORE RIDGING WEDNESDAY INTO THURSDAY AHEAD OF ANOTHER
SYSTEM ENTERING THE WEST COAST. MEDIUM RANGE MODELS SHOWED THIS NEXT
SYSTEM BRINGING A GOOD CHANCE OF PRECIPITATION TO THE AREA BY FRIDAY
EVENING INTO SATURDAY. DAYTIME TEMPERATURES WILL REMAIN NEAR OR A
FEW DEGREES ABOVE NORMAL READINGS THROUGH NEXT WEEK.
&&
.AVIATION...VALID THRU 07/12Z.
BKN-OVC HIGH CLOUDS...MAINLY ABOVE 16K FT AGL...WITH FEW-SCT CLOUDS
AT 6-10K FT AGL DEVELOPING BY 06/18Z. SLIGHT CHANCE OF -SHRA MAINLY
OVER THE HIGHER TERRAIN AND MAINLY AFT 06/18Z. LOCAL AREAS OF BR
EARLY THIS MORNING...DIMINISHING BY 06/16Z. WINDS WILL REMAIN
LIGHT...GENERALLY LESS THAN 10 KTS THROUGH THE FORECAST PERIOD.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...A WEAK SYSTEM WILL MOVE NORTH OF THE REGION TODAY.
THIS SYSTEM WILL RESULT IN A SLIGHT CHANCE OF SHOWERS...MAINLY OVER
THE HIGHER TERRAIN TODAY AND TONIGHT. WINDS ARE EXPECTED TO BE LIGHT
INTO THE MIDDLE OF NEXT WEEK...GENERALLY LESS THAN 15 MPH. HIGH
TEMPERATURES WILL BE 2 TO 5 DEGREES ABOVE SEASONAL AVERAGES THROUGH
THE WEEKEND AND 4 TO 8 DEGREES ABOVE NORMAL NEXT WEEK.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS SAN JOAQUIN VALLEY - HANFORD CA
1155 PM PST FRI DEC 5 2014
.SYNOPSIS...
ANOTHER WEAK SYSTEM WILL BRING SOME LIGHT SHOWERS INTO THE AREA
MAINLY NORTH OF KERN COUNTY TONIGHT. DRY CONDITIONS ARE EXPECTED BY
SATURDAY NIGHT WITH NIGHTTIME AND MORNING VALLEY FOG AS HIGH
PRESSURE BRIEFLY RETURNS. ANOTHER WEAK SYSTEM IS EXPECTED TO SKIRT
ACROSS THE NORTHERN PORTION OF THE STATE ON MONDAY...WITH LIGHT RAIN
POSSIBLE NORTH OF FRESNO COUNTY.
&&
.DISCUSSION...
QUICK UPDATE TO THE FORECAST TO INCLUDE FOG FOR THE NORTHERN
ANTELOPE VALLEY/SOUTHEAST KERN COUNTY AND LOWER POPS CWA-WIDE.
POPS...FORCING IS FALLING APART WITH THE SYSTEM TRAVERSES OUR CWA.
HRRR AND OTHER HI-RES MODELS AGREE THAT SHOWERS WILL CONTINUE TO
DRASTICALLY DECREASE NEXT FEW HOURS THEREFORE HAVE REDUCED POPS
MOST AREAS.
NEXT UP IS FOG POTENTIAL FOR PARTS OF THE MOJAVE DESERT.
VISIBILITY SENSORS THERE ARE ALREADY TRENDING DOWN INTO THE 5-6SM
RANGE. BASED ON UPS METHOD/CROSSOVER TEMPERATURES FOG IS LIKELY TO
FORM. FOR EXAMPLE...THE XOVER TEMP AT KMHV IS 45F AND CURRENT TEMP
IS ALREADY DOWN TO 50 /WITH 100 PERCENT HUMIDITY/. THE FORECAST
LOW IS IN THE LOWER 40S. ADDITIONAL SUPPORT INCLUDES THE VEGAS
SOUNDING SHOWING A SATURATED BOUNDARY LAYER/INCREASING HUMIDITY
WITH HEIGHT. FINALLY...SEVERAL RUNS OF THE HRRR HAVE GENERATED FOG
IN THAT AREA OVER THE NEXT FEW HOURS. THEREFORE ADDED FOG TO
FORECAST. WILL MONITOR OVERNIGHT FOR POTENTIAL OF A DENSE FOG
ADVISORY BUT WILL COVER THE MESSAGE VIA OUR SOCIAL MEDIA CHANNELS
FOR NOW.
&&
.PREV DISCUSSION... /ISSUED 348 PM PST FRI DEC 5 2014/
DISCUSSION...IT HAS BEEN A RELATIVELY MILD DAY ACROSS CENTRAL
CALIFORNIA TODAY UNDER CLOUDY SKIES AHEAD OF THE NEXT APPROACHING
WEAK FRONTAL SYSTEM. RADAR SHOWS ASSOCIATED SHOWERS IMPACTING
COASTAL AREAS TO OUR WEST. HIGH RESOLUTION MODELS PROG THESE
SCATTERED SHOWERS TO PUSH EAST THROUGH OUR AREA THIS EVENING
LINGERING INTO EARLY SATURDAY MORNING...THOUGH THE BEST PRECIP
STAYS TO OUR NORTH WITH THE MAIN ENERGY. VALLEY QPF RANGES FROM
AROUND 1/10 OF AN INCH NORTH TO JUST A HUNDREDTH OR SO TOWARD
KERN COUNTY. HIGHER ELEVATION AMOUNTS SIMILARLY TAPER FROM AROUND
A QUARTER INCH NEAR YOSEMITE TO NOTHING IN KERN COUNTY.
BRIEF SHORTWAVE RIDGING BEHIND THE SYSTEM YIELDS DRY AND CONTINUED
MILD CONDITIONS SATURDAY AND SUNDAY. ANOTHER WEAK RIPPLE TRACKS BY
TO THE NORTH BY MONDAY...BRINGING JUST A SLIGHT CHANCE FOR PRECIP
NORTH OF FRESNO COUNTY. OTHERWISE...DRY AND MILD CONTINUES INTO
MIDWEEK.
A MORE SIGNIFICANT SYSTEM...REMNANTS OF A SUPER TYPHOON...IS
PROGGED TO SLAM INTO THE WEST COAST BY THURSDAY. MODELS OF COURSE
HAVE DIFFERENCES IN TIMING AND STRENGTH OF THIS SYSTEM...BUT
ENSEMBLES SUGGEST THERE IS A GOOD CHANCE THAT OUR AREA WILL BE
AFFECTED WITH RAIN AND MOUNTAIN SNOW AS WELL AS TYPICAL GUSTY
WINDS OVER MOUNTAIN RIDGES AND THROUGH AND BELOW PASSES. THIS WILL
BE A SOMEWHAT WARM STORM WITH RELATIVELY HIGH SNOW LEVELS. AS THE
EVENT APPROACHES WE WILL BE ABLE TO REFINE TIMING AND AMOUNTS.
&&
.AVIATION...
SCATTERED LIGHT RAIN SHOWERS THIS EVENING THRU 12Z SAT...MVFR
CEILINGS WITH LOCAL IFR POSSIBLE AT TIMES...MAINLY NORTH OF KERN
COUNTY. OTHERWISE EXPECT VFR CONDITIONS TO PREVAIL OVER THE CENTRAL
CALIFORNIA INTERIOR OVER THE NEXT 24 HOURS.
&&
.AIR QUALITY ISSUES...
NONE.
&&
.CERTAINTY...
THE LEVEL OF CERTAINTY FOR DAYS 1 AND 2 IS HIGH.
THE LEVEL OF CERTAINTY FOR DAYS 3 THROUGH 7 IS MEDIUM.
THIS INFORMATION IS PROVIDED AS PART OF A TRIAL PROJECT CONDUCTED
BY THE NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD.
CERTAINTY LEVELS INCLUDE LOW...MEDIUM...AND HIGH. PLEASE VISIT
WWW.WEATHER.GOV/HNX/CERTAINTY.PHP /ALL LOWER CASE/ FOR ADDITIONAL
INFORMATION AND/OR TO PROVIDE FEEDBACK.
&&
.CLIMATE...
RECORDS
SITE DATE HI_MAX:YEAR LO_MAX:YEAR HI_MIN:YEAR LO_MIN:YEAR
KFAT 12-05 72:1958 40:1963 52:2012 28:1903
KFAT 12-06 68:1995 42:1965 55:2012 28:1891
KFAT 12-07 69:1937 42:1965 52:1950 25:1978
KBFL 12-05 80:1918 43:1965 55:1966 23:1903
KBFL 12-06 77:1916 42:1965 60:1918 22:1903
KBFL 12-07 76:1907 41:1965 53:1950 24:1912
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
PUBLIC...INIGUEZ
AVN/FW...BSO
PREV DISCUSSION...JEB
SYNOPSIS...BSO
WEATHER.GOV/HANFORD
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1157 AM MST SAT DEC 6 2014
.UPDATE...
ISSUED AT 1149 AM MST SAT DEC 6 2014
LOTS OF MID/HIGH CLOUDINESS SPREADING ACROSS SOUTHERN CO AHEAD OF
THE NEXT UPPER TROF MOVING INTO THE SOUTHWEST US. THIS HAS
RESULTED IN A SLOW WARM UP FOR PORTIONS OF THE LOWER ARKANSAS
RIVER VALLEY...KPUB TO KLHX...WHERE TEMPERATURES HAVE HELD IN THE
UPPER 30S. HAVE DROPPED MAX TEMPERATURE FOR TODAY A DEGREE OR TWO
FOR KPUB AND KLHX...AS WINDS SHOULD STAY LIGHT LIMITING MIXING.
ELSEWHERE...SOUTHERLY WINDS ACROSS THE SOUTHERN AND EASTERN
PORTIONS OF THE PLAINS SHOULD HELP TEMPERATURES WARM INTO THE
LOWER 50S. MEANWHILE...STARTING TO SEE THE FIRST ROUNDS OF SNOW
VIA KCPW OBSERVATION. THIS SHOULD BECOME MORE WIDESPREAD THROUGH
LATE AFTERNOON AND INTO THE EVENING AS THE UPPER TROF APPROACHES.
HAVE DELAYED THE ONSET OF SNOW FOR THE SANGRES BASED ON THE
LATEST SOLUTIONS FROM HRRR AND RAP13...OTHERWISE...POP GRIDS LOOK
ON TARGET. -KT
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 339 AM MST SAT DEC 6 2014
...SOME LIGHT SNOW FOR THE MOUNTAINS LATER TODAY...
A BROAD EXPANSE OF THICK HIGH CLOUDS IS OVERSPREADING WRN CO THIS
MORNING. THIS IS ASSOCIATE WITH A TROUGH THAT IS CROSSING THE W
COAST. THIS WEAK SYSTEM WILL MOVE STEADILY THROUGH THE DESERT SW
THIS MORNING...THEN PASS THROUGH ERN CO THIS EVE. CLOUD COVER SHOULD
STAY WITH US THROUGH THIS AFTERNOON...THEN GRADUALLY CLEAR
OVERNIGHT FROM W TO E. CLOUDS AND SLIGHT COOLING ALOFT WILL HOLD MAX
TEMPS ABOUT 10 DEGREES BELOW ADIABATIC MAXES...OR AROUND 50 DEGREES
FOR THE PLAINS...AND 40S FOR THE HIGH VALLEYS.
NOT SEEING MUCH POTENTIAL FOR SNOWFALL WITH THIS SYSTEM GIVEN THE
GENERALLY WEAK DYNAMICS AND QUICK PROGRESSION. BEST CHANCE FOR SOME
LIGHT ACCUMS WILL BE OVER THE SW MTS...WHICH COULD SEE 2-4 INCHES BY
SUN MORNING...MAYBE A BIT HIGHER IN SPOTS. ELSEWHERE ALONG THE
CONTDVD...JUST AN INCH OR TWO. ERN RANGES WILL SEE SOME SCT SNOW
SHOWERS AND POSSIBLY SOME LIGHT ACCUMS FOR THE HIGHER ELEVATIONS.
LOOKS RELATIVELY MILD TONIGHT FOR THE PLAINS WITH TEMPS IN THE
UPPER 20S TO AROUND FREEZING. ROSE
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 339 AM MST SAT DEC 6 2014
GENERALLY MILD AND DRY CONDITIONS ARE FORECAST TO PREVAIL ACROSS
THE REGION THROUGH THE EXTENDED PERIOD.
A FAST MOVING UPPER LEVEL SHORTWAVE TROUGH WILL BE MOVING EAST OF
THE AREA SUNDAY MORNING WITH HIGH PRESSURE ALOFT BUILDING ACROSS
THE REGION BY SUNDAY AFTERNOON. MODELS HANG ON TO A FEW LIGHT SNOW
SHOWERS OVER THE MOUNTAINS SUNDAY MORNING...WITH ALL SHOWER
ACTIVITY COMING TO AN END BY MID TO LATE MORNING SUNDAY. MIGRANT
HIGH PRESSURE WILL MOVE ACROSS THE REGION THROUGH TUESDAY. DRY
CONDITIONS WILL PERSIST UNDER THIS HIGH PRESSURE. TEMPERATURES
WILL REMAIN MILD ACROSS THE REGION WITH 50S FOR THE PLAINS FOR
AFTERNOON HIGHS.
A WEAK SHORTWAVE TROUGH IS FORECAST TO MOVE ACROSS THE DESERT
SOUTHWEST ON WEDNESDAY. ALL MODEL GUIDANCE HAS THIS DISTURBANCE
MOVING TOO FAR TO THE SOUTH TO BRING ANY PRECIPITATION TO THE
AREA. A WEAK COLD FRONT WILL IMPACT THE PLAINS...WITH A FEW
DEGREES OF COOLING EXPECTED WEDNESDAY AFTERNOON.
HIGH PRESSURE IS FORECAST TO BUILD ACROSS THE AREA FOR LATE IN THE
WEEK AS A TROUGH STRENGTHENS ALONG THE WEST COAST. THE UPPER FLOW
ACROSS COLORADO WILL TRANSITION TO SOUTHWESTERLY BY THURSDAY WHICH
WILL AID IN AFTERNOON MIXING. EXPECT A NICE WARM UP THURSDAY AND
FRIDAY WITH LOWER 60S EXPECTED ACROSS THE PLAINS. THERE ARE SOME
MODEL DIFFERENCES FRIDAY INTO SATURDAY...THE GFS IS FASTER IN
BRINGING THE UPPER SYSTEM OFF THE WEST COAST AND ACROSS COLORADO.
THE GFS DEVELOPS WIDESPREAD PRECIPITATION ACROSS THE CONTINENTAL
DIVIDE BY FRIDAY NIGHT...AND SPREADING ACROSS THE AREA ON
SATURDAY. THE ECMWF IS ABOUT 24 HOURS SLOWER WITH THIS SYSTEM
KEEPING COLORADO DRY THROUGH SATURDAY. THIS SYSTEM WILL NEED TO BE
MONITORED...AS IT COULD BRING DECENT SNOWFALL TO THE CONTINENTAL
DIVIDE. MOZLEY
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1006 AM MST SAT DEC 6 2014
CIGS WILL LOWER THROUGH THE DAY AS A DISTURBANCE OUT WEST MOVES
ACROSS THE REGION. CIGS WILL REMAIN VFR AT KCOS AND KPUB WITH
WINDS INCREASING OUT OF THE SOUTH AT AROUND 10 KTS AT KCOS DURING
THE AFTERNOON. KPUB WILL SEE LIGHTER WINDS FROM THE EAST. SNOW
WILL REMAIN CONFINED TO THE MOUNTAIN AREAS TODAY. KALS MAY SEE A
PASSING SHOWER IN THE VICINITY OF THE TERMINAL THIS EVENING...BUT
PROBABILITY LOOKS TOO LOW AT THIS POINT TO WARRANT INCLUSION IN
THE TAF. MEANWHILE MOUNTAIN AREAS WILL SEE IFR TO LIFR
CONDITIONS...PARTICULARLY ALONG THE CONTDVD WHERE SNOW SHOWERS
WILL INCREASE THROUGH THE AFTERNOON AND CONTINUE THROUGH TONIGHT.
-KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KT
SHORT TERM...ROSE
LONG TERM...MOZLEY
AVIATION...KT
AREA FORECAST DISCUSSION
NWS MIAMI FL
313 AM EST SAT DEC 6 2014
.SYNOPSIS...
GENERALLY DRY CONDITIONS WILL PREVAIL INTO NEXT WEEK...WITH
SLIGHTLY COOLER TEMPERATURES ARRIVING BY TUESDAY.
&&
.SHORT TERM /TODAY THROUGH MONDAY/...
SURFACE HIGH PRESSURE THAT HAS BEEN WEDGED ON THE LEE SIDE OF THE
APPALACHIANS AND DOMINATING SOUTH FLORIDA WEATHER THIS WEEK WILL
FINALLY SPREAD OFFSHORE. THIS WILL RESULT IN LIGHTER WINDS FROM A
MORE NORTHERLY DIRECTION TODAY. LESS MOIST LOW-LEVELS SHOULD
PRECLUDE THE ISOLATED/SCATTERED SHOWER ACTIVITY THAT HAS PESTERED
THE ATLANTIC COAST MUCH OF THIS WEEK. A SHORTWAVE TROUGH WILL
CROSS THE NORTHEAST CONUS THIS WEEKEND...WITH THE ATTENDANT COLD
FRONT ENTERING NORTHERN FLORIDA LATE TONIGHT. THIS FRONT WILL
DISSIPATE AS IT PASSES CENTRAL FLORIDA...BUT HIGH PRESSURE WILL
STILL BUILD SOUTHWARD INTO SOUTH FLORIDA SUNDAY INTO MONDAY. THE
DRYING TREND WILL CONTINUE THIS WEEKEND...AND ABOVE NORMAL
TEMPERATURES TODAY WILL GRADUALLY DIP TO NEAR NORMAL BY
MONDAY...AS MODIFIED CANADIAN AIRMASS FILTERS IN.
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
A DEEPER SHORTWAVE TROUGH /PARTICULARLY IF THE ECMWF VERIFIES/
WILL CROSS NERN STATES LATE MONDAY INTO TUESDAY. ANOTHER...LIKELY
DRY FRONT...WILL ENTER NORTH FLORIDA AND THIS TIME CROSS THE
PENINSULA. THE MODEL DISCREPANCIES OF THE PAST SEVERAL DAYS HAVE
DIMINISHED...AND APPEAR TO BE CONVERGING ON NOTICEABLY COOLER AND
DRIER AIRMASS BEHIND THE FRONT FOR TUESDAY THROUGH THURSDAY.
TEMPERATURES WILL LIKELY BE SLIGHTLY BELOW NORMAL...WITH MAXIMA
MAINLY IN THE LOW 70S...MINIMA RANGING FROM UPPER 40S NW TO AROUND
60F ATLANTIC COAST. FLOW WILL REMAIN N OR NW UNTIL THURSDAY...THEN
MODERATING TEMPERATURES AND INCREASING MOISTURE COMMENCE AS WINDS
TURN NE. SHOWER CHANCES WILL REMAIN SLIGHT AT BEST THROUGH THE
PERIOD.
&&
.AVIATION...
LIGHT SHOWERS CONTINUE TO EXIT THE EAST COAST SITES...PUSHING OFF
TOWARD THE INTERIOR. LATEST HRRR KEEPS THE TAF SITES DRY THROUGH
THE REMAINDER OF THE NIGHT. THEREFORE REMOVED VCSH MENTION. WINDS
WILL CONTINUE TO BE GENERALLY EASTERLY AT AROUND 10 KNOTS OR LESS
THROUGH THE MORNING AND INTO THE AFTERNOON HOURS BEFORE DECREASING
AND BACKING MORE TO THE NORTHEAST INTO THE EVENING HOURS. KAPF
SHOULD SEE A NORTHWEST FLOW COMING IN FROM THE GULF OF MEXICO
TOWARD THE EARLY TO MID AFTERNOON HOURS.
&&
.MARINE...
AS THE CENTER OF HIGH PRESSURE MOVES N/E AWAY FROM WATERS
TODAY...WINDS WILL CONTINUE TO SUBSIDE. NE WINDS TODAY WILL TURN
NORTHERLY INTO EARLY NEXT WEEK AS WEAK COLD FRONT/NEW HIPRES
SPREAD OVER THE WATERS. A MORE SIGNIFICANT FRONT ON TUESDAY MAY
RESULT IN INCREASING WINDS AND SEAS FOR WEDNESDAY AND THURSDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 81 64 79 65 / 10 0 10 10
FORT LAUDERDALE 80 68 80 68 / 10 0 10 10
MIAMI 81 67 80 66 / 10 0 10 10
NAPLES 80 63 76 62 / 0 10 10 0
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK UNTIL 7 AM EST THIS MORNING FOR FLZ168-172-
173.
AM...HIGH RIP CURRENT RISK UNTIL 7 AM EST THIS MORNING FOR AMZ630.
GM...NONE.
&&
$$
SHORT TERM...23/SK
LONG TERM....23/SK
AVIATION...10/CD
AREA FORECAST DISCUSSION
NWS MIAMI FL
100 AM EST SAT DEC 6 2014
.AVIATION...
LIGHT SHOWERS CONTINUE TO EXIT THE EAST COAST SITES...PUSHING OFF
TOWARD THE INTERIOR. LATEST HRRR KEEPS THE TAF SITES DRY THROUGH
THE REMAINDER OF THE NIGHT. THEREFORE REMOVED VCSH MENTION. WINDS
WILL CONTINUE TO BE GENERALLY EASTERLY AT AROUND 10 KNOTS OR LESS
THROUGH THE MORNING AND INTO THE AFTERNOON HOURS BEFORE DECREASING
AND BACKING MORE TO THE NORTHEAST INTO THE EVENING HOURS. KAPF
SHOULD SEE A NORTHWEST FLOW COMING IN FROM THE GULF OF MEXICO
TOWARD THE EARLY TO MID AFTERNOON HOURS.
&&
.PREV DISCUSSION... /ISSUED 958 PM EST FRI DEC 5 2014/
UPDATE...
GUIDANCE SHOWS RELATIVELY DRIER AIR ARRIVING THROUGH THE LOW
LEVELS, BY SATURDAY MORNING, ACROSS SOUTH FLORIDA. THIS SHOULD
BRING AN END TO THE NEARLY PERPETUAL COASTAL AND OFFSHORE SHOWERS
BY LATE TONIGHT. OTHERWISE, THE OVERNIGHT WILL BE WARM AND HUMID.
PREV DISCUSSION... /ISSUED 303 PM EST FRI DEC 5 2014/
DISCUSSION...
THE UPPER LEVEL PATTERN CONSISTED OF HIGH PRESSURE OVER THE SOUTH
CENTRAL GULF OF MEXICO...AND A SHORTWAVE MOVING ACROSS THE
SOUTHERN PLAINS. AT THE SURFACE...STRONG HIGH PRESSURE WAS
CENTERED OVER NEW BRUNSWICK AND NOVA SCOTIA AND STRETCHED DOWN THE
EAST COAST. AN AREA OF LOW PRESSURE WAS BEGINNING TO DEVELOP OVER
NORTH TEXAS AND OKLAHOMA. EASTERLY FLOW WITH QUICK MOVING SHOWERS
WILL CONTINUE THROUGH THE AFTERNOON WITH HIGHS IN TEMPS IN THE LOW
80S.
TONIGHT...THE SHORTWAVE WILL PUSH EASTWARD AND SURFACE LOW
PRESSURE WILL MOVE QUICKLY NORTHEASTWARD INTO KENTUCKY. WINDS
WILL SHIFT TO THE NORTHEAST...AND DRIER AIR WILL BEGIN TO MOVE
INTO SOUTH FLORIDA. A FEW LIGHT SHOWERS IN THE EVENING SHOULD GIVE
WAY TO DRY CONDITIONS OVERNIGHT.
SATURDAY...AN AMPLIFIED PATTERN WILL TAKE PLACE ACROSS THE CONUS
AS A COUPLE SHORTWAVES PUSH INTO THE WEST COAST...WITH HIGH
PRESSURE EXTENDING FROM MEXICO INTO THE NORTHERN PLAINS AND
CANADA. AN UPPER LEVEL SHORTWAVE ACROSS THE SOUTHERN PLAINS WILL
DIG ACROSS THE SOUTHERN APPALACHIANS ON SATURDAY. A COLD FRONT
WILL PUSH INTO THE SOUTHEAST STATES. A LIGHTER NORTHEASTERLY FLOW
WITH MAINLY DRY CONDITIONS WILL PREVAIL. HIGHS ARE FORECAST TO BE
IN THE UPPER 70S TO LOWER 80S.
SUNDAY...A WEAK COLD FRONT WILL PUSH INTO NORTHERN AND CENTRAL
FLORIDA AS HIGH PRESSURE SURGES INTO THE EASTERN CONUS. THE FRONT
IS FORECAST TO BE MAINLY DRY AND BECOME DIFFUSE AS IT MOVES INTO
CENTRAL FLORIDA. A FEW SHOWERS MAY MOVE SOUTH AND SOUTHWEST OVER
THE ATLANTIC WATERS AND TOWARDS PALM BEACH COUNTY IN THE
AFTERNOON. OTHERWISE...DRY CONDITIONS WITH NEAR NORMAL
TEMPERATURES ARE EXPECTED.
MONDAY THROUGH THURSDAY...MODELS BEGIN TO DIVERGE BEGINNING ON
MONDAY. THE MODELS DIFFER ON THEIR HANDLING OF THE SHORTWAVES AND
THEIR PHASING AS THEY MOVE ACROSS THE GREAT LAKES AND SOUTHEAST ON
MONDAY. THE ECMWF KEEPS THE ACTIVITY MORE PHASED AND FURTHER NORTH
INITIALLY...AND THEN DEVELOPS A SURFACE LOW OVER THE GULF STREAM
AND MOVES IT UP THE EAST COAST. THIS PUSHES A STRONGER FRONT
THROUGH SOUTH FLORIDA ON TUESDAY...WITH NORTHWESTERLY FLOW THE
REST OF THE WEEK. THE GFS HAS A MUCH WEAKER LOW OVER THE EAST
COAST...AND HAS THE NORTHERN LOW OVER CANADA AS THE DOMINANT ONE.
THIS PUSHES THROUGH A MUCH WEAKER BOUNDARY...WITH HIGH PRESSURE
MOVING INTO THE SOUTHEAST BY THURSDAY. THIS WOULD RESULT IN
NORTHEASTERLY WINDS RETURNING TO THE REGION...ENDING THE COOLER
CONDITIONS. THE MOST RECENT RUN OF THE GFS HAS TRENDED
COOLER...BUT IS STILL WARMER THAN THE ECMWF. THE FORECAST WILL
LEAN MORE TOWARDS THE ECMWF SOLUTION...WITH HIGHS IN THE LOW 70S
AND LOWS MAINLY IN THE 50S.
MARINE...
HIGH PRESSURE WILL WEAKEN NORTH OF THE REGION ON SATURDAY AS A
COLD FRONT PUSHES INTO THE SOUTHEAST. WINDS WILL SHIFT TO THE
NORTHEAST. THE WEAK FRONT WILL PUSH INTO CENTRAL FLORIDA ON
SUNDAY...WITH WEAK NORTHEASTERLY FLOW CONTINUING. A FRONT IS
FORECAST TO PUSH THROUGH THE REGION EARLY NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 79 64 78 63 / 10 0 20 20
FORT LAUDERDALE 80 67 79 64 / 10 0 10 10
MIAMI 81 66 80 63 / 10 0 10 10
NAPLES 81 62 77 59 / 0 0 10 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK UNTIL 7 AM EST THIS MORNING FOR FLZ168-172-
173.
AM...HIGH RIP CURRENT RISK UNTIL 7 AM EST THIS MORNING FOR AMZ630.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
611 PM EST SUN DEC 7 2014
.SYNOPSIS...
MOISTURE IS EXPECTED TO SPREAD BACK INTO THE REGION LATE TONIGHT
AND MONDAY WITH WELL BELOW NORMAL TEMPERATURES AND CONSIDERABLE
CLOUDINESS. THERE WILL BE A CHANCE OF LIGHT RAIN BY MONDAY
AFTERNOON...ESPECIALLY EASTERN MIDLANDS AS WEAK LOW PRESSURE
DEVELOPS OFFSHORE. HIGH PRESSURE WILL BUILD INTO THE AREA MID WEEK
WITH TEMPERATURES SLIGHTLY BELOW NORMAL.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
A STRONG 1044MB SURFACE HIGH PRESSURE SYSTEM LOCATED OVER
SOUTHEASTERN CANADA CONTINUES TO RIDGE SOUTHWARD ALONG THE EAST
COAST THIS EVENING. LOWER CLOUDS FINALLY CLEARED OUT OF THE AREA
MID AFTERNOON ALLOWING FOR MOSTLY CLEAR SKIES BUT SATELLITE
IMAGERY SHOWS THE CLOUDS JUST OFFSHORE. AN APPROACHING SHORTWAVE
TROUGH CURRENTLY OVER THE PLAINS STATES WILL APPROACH LATE
TONIGHT AND INDUCE SURFACE LOW PRESSURE DEVELOPMENT
OFFSHORE...ALLOWING THE LOW LEVEL MOISTURE AND CLOUDS TO RETURN TO
THE AREA BY MORNING. WEAK ISENTROPIC LIFT WILL BEGIN LATE TONIGHT
BUT DRY AIR IN PLACE SHOULD PREVENT ANY PRECIPITATION. OVERNIGHT
LOWS WILL DROP INTO THE LOWER TO MID 30S ACROSS THE FORECAST AREA.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
UPPER TROUGH MOVING THROUGH THE GULF COAST AND SOUTHEASTERN STATES
MONDAY WILL RESULTING SOUTHWEST FLOW ALOFT OVER CAROLINAS. SURFACE
RIDGE EXTENDING FROM THE CANADIAN MARITIMES SOUTHWEST ACROSS THE
MID ATLANTIC TO THE CAROLINAS. WEAK SURFACE LOW WILL BE DEVELOPING
WELL EAST OF THE CAROLINA COAST BY MONDAY AFTERNOON. MODELS
CONTINUE TO INDICATE COLD AIR DAMMING IN THE CAROLINAS...ALTHOUGH
WEAK DUE TO LACK OF SIGNIFICANT ISENTROPIC LIFT AND SHALLOW
MOISTURE. EXPECT CONSIDERABLE CLOUDINESS PROBABLY OVERCAST BY LATE
MORNING WITH WEAK SOUTHEAST 850MB MOISTURE ADVECTION OFF ATLANTIC. AS
COASTAL LOW MOVES A LITTLE CLOSER TO THE NORTH CAROLINA COAST
MONDAY AFTERNOON AND EVENING IN RESPONSE TO APPROACHING MID LEVEL
SHORT WAVE TROUGH...WEAK LOW LEVEL CONVERGENCE NOTED IN THE NORTH
AND EAST AND ENOUGH LIFT FOR SOME PATCHY LIGHT RAIN/DRIZZLE. SO
RAISED POPS ESPECIALLY NORTH AND EAST MIDLANDS/PEE DEE THROUGH
EVENING...BUT QPF LIKELY QUITE LOW. TEMPERATURES...PREFER SREF MEAN
WHICH IS BELOW MOS AVERAGE/NEAR CURRENT FORECAST AND REASONABLE
BASED ON LOCAL WEDGE SCHEME. LINGERING CLOUDINESS MONDAY NIGHT MAY
RESULT IN OVERNIGHT TEMPERATURES ABOVE MOS MEAN. WEDGE ERODING
EARLY TUESDAY...SOME MORNING CLOUDS BUT EXPECT CLEARING THROUGH
DAY WITH DOWNSLOPE...CLOUDINESS LIKELY TO REMAIN MAINLY NORTH AND
WEST. GUIDANCE TEMPERATURES IN THE MID 50S ON TRACK.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
MODELS SHOW THE UPPER LOW CLOSING OFF AND BECOMING STACKED WITH
THE SURFACE LOW OVER THE NORTHEASTERN STATES ON WEDNESDAY.
SURFACE HIGH PRESSURE OVER THE CENTRAL CONUS WILL RIDGE INTO THE
SOUTHEASTERN STATES. THIS PATTERN WILL PROMOTE
WESTERLY/NORTHWESTERLY FLOW ACROSS THE FORECAST AREA. SURFACE HIGH
PRESSURE WILL CONTINUE TO DOMINATE THE PATTERN WEDNESDAY THROUGH
THE END OF THE LONG TERM PERIOD. STRONG NOCTURNAL COOLING WITH THE
RIDGE NEAR THE AREA SHOULD RESULT IN COLD LOW TEMPERATURES IN THE
UPPER 20S TO LOWER 30S WEDNESDAY THROUGH SUNDAY. MAX TEMPS ARE
FORECAST BELOW CLIMATOLOGY IN THE 50S EARLY IN THE PERIOD WITH
SLIGHT WARMING TREND INTO THE WEEKEND.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
CLOUDINESS...WITH MVFR CIGS...PUSHING SOUTH. TEMPO PERIODS OF MVFR
CIGS IN THE NEAR TERM AT OGB...OTHERWISE VFR CONDITIONS EXPECTED
THROUGH THIS EVENING. BREEZY NE WINDS INDICATING TREND TOWARDS
SLIGHTLY DECREASING SPEEDS.
SURFACE HIGH PRESSURE RIDGE WILL REMAIN ANCHORED ALONG THE EAST COAST
THROUGH MONDAY. MODELS INDICATING PREMISE FOR INCREASING CLOUDINESS
TO REENTER THE FORECAST AREA FROM THE SOUTH AND EAST LATE TONIGHT
DUE TO WEAK ISENTROPIC LIFT AHEAD OF AN APPROACHING UPPER
TROUGH...AND PERSIST THROUGH MUCH OF MONDAY. SOME MODEL DISCREPANCY
ON CEILING HEIGHTS...CHOSE TO LEAN TOWARDS RAP MODEL PROJECTION OF
MVFR CIGS...WHICH SEEMS PLAUSIBLE AT THIS TIME GIVEN THE SITUATION.
RAIN CHANCES APPEAR TOO LOW TO INCLUDE IN THE TAFS AT THIS TIME.
EXTENDED AVIATION OUTLOOK...MVFR RESTRICTIONS EXPECTED TO PERSIST
THROUGH TUESDAY MORNING. OTHERWISE...NO SIGNIFICANT IMPACTS TO
AVIATION EXPECTED LATE TUESDAY THROUGH THURSDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...FLASH FLOOD WATCH THROUGH TUESDAY EVENING FOR SCZ030.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
914 PM CST SUN DEC 7 2014
.UPDATE...
914 PM...EVENING UPDATE...OVERALL NO SIGNIFICANT CHANGES TO THE
FORECAST FOR OVERNIGHT OR MONDAY MORNING. FAIRLY NARROW BAND OF
PRECIP IS MOVING ACROSS EAST CENTRAL IA THIS EVENING. A FEW
LIGHTNING STRIKES OCCURRED EARLIER THIS EVENING NEAR KMCW IN
NORTHERN IA. AUTOMATED SITES HAVE REPORT UNKNOWN PRECIP...HEAVY IN
FEW OBS...WITH SURFACE TEMPS AT OR JUST ABOVE FREEZING.
DESPITE OBSERVED 00Z ILX/DVN SOUNDINGS SHOWING +8C AND +6C TEMPS
AROUND 900MB RESPECTIVELY...THERE REMAINS QUITE A BIT OF DRY AIR
THAT WILL NEED TO SATURATE...LIKELY VERY QUICKLY...AS PRECIP
ARRIVES. THUS THIS WARM LAYER WILL LIKELY BE COOLED SUFFICIENTLY
FOR A WINTRY MIX AT FIRST...THEN IF PRECIP INTENSITY BECOMES HEAVY
ENOUGH...A SHORT PERIOD OF SNOW. CONFIDENCE IS TOO LOW TO MAKE ANY
SIGNIFICANT CHANGES TO THE CURRENT FORECAST. ONLY MINOR CHANGE WAS
TO TWEAK TIMING TO SLOW PRECIP ONSET.
AIR TEMPS HAVE COOLED INTO THE UPPER 20S/NEAR 30 ACROSS MUCH OF
THE NORTHWEST CWA...WITH TEMPS STILL NEAR FREEZING OVER THE REST
OF THE CWA. SURFACE TEMPS MAY WARM A FEW DEGREES BUT WILL LIKELY
STAY NEAR FREEZING THRU DAYBREAK. SO REGARDLESS OF PRECIP TYPE...
SOME ICING OF UNTREATED SURFACES IS POSSIBLE...ESPECIALLY WHERE
TEMPS ARE NOW IN THE UPPER 20S. NO PLANS FOR ANY HEADLINES THIS
EVENING...BUT THAT POSSIBILITY WILL NEED TO BE MONITORED AS TRENDS
EMERGE OVERNIGHT. THUS NO PLANS TO MODIFIED CURRENT SPS WHICH
RUNS THROUGH 09Z. CMS
&&
.SHORT TERM...
TONIGHT THROUGH MONDAY... 314 PM CST
THE MAIN WEATHER CONCERN FOR TONIGHT INTO MONDAY IS THE QUICK HIT
OF A WINTERY MIX LATE TONIGHT INTO MONDAY MORNING...WITH THE
POTENTIAL OF BRIEF PERIOD OF A HEAVY BURST OF SNOW ACROSS FAR
NORTHERN ILLINOIS EARLY MONDAY MORNING DURING THE MORNING RUSH.
WATER VAPOR IMAGERY INDICATES OUR STORM SYSTEM OF INTEREST DIGGING
EAST-SOUTHEASTWARD ACROSS THE NORTHERN HIGH PLAINS. THE ASSOCIATED
AREA OF SURFACE LOW PRESSURE IS EXPECTED TO TRACK QUICKLY ALONG OR
NEAR THE CANADIAN BORDER THROUGH TUESDAY. WARM AIR
ADVECTION/ISENTROPIC ASCENT IS ALREADY RAMPING UP ACROSS THE AREA
OUT AHEAD OF THIS FEATURE...AND REGIONAL RADAR TRENDS ARE BEGINNING
TO SHOW PRECIPITATION DEVELOPING TO OUR WEST-NORTHWEST IN ASSOCIATION
WITH THE APPROACHING SURFACE FRONTAL BOUNDARY.
THE COMBINATION OF GOOD LARGE SCALE FORCING (Q-VECTOR CONVERGENCE)
ASSOCIATED WITH THE APPROACHING MID LEVEL SHORT WAVE ENERGY...ALONG
WITH WHAT APPEARS MAY END UP BEING A RATHER STOUT BAND OF MID LEVEL
FRONTOGENESIS...SHOULD PROVIDE A SHORT...BUT POTENTIALLY INTENSE
PERIOD OF PRECIPITATION ACROSS NORTHERN ILLINOIS/NORTHWESTERN
INDIANA EARLY MONDAY MORNING. MODEL SOUNDINGS ACROSS THE AREA ALL
INDICATE THE PRESENCE OF SOME VERY IMPRESSIVE MID LEVEL LAPSE RATES
(UP AROUND 7 DEGREES C/KM IN THE 700-500 MB LAYER) DURING THE PERIOD
OF MAXIMUM FORCING FOR ASCENT. IN ADDITION...CROSS SECTIONS ACROSS
NORTHERN ILLINOIS ALSO INDICATE THE PRESENCE OF NEGATIVE EPV...WITH
FOLDING THETA E SURFACES IN THE 500 TO 700 MB LAYER. THIS ALL
POINTS TO THE LIKELIHOOD OF A SHORT...BUT POTENTIALLY INTENSE BAND OF
PRECIPITATION DURING THE MORNING RUSH ACROSS NORTHERN
ILLINOIS/NORTHWESTERN INDIANA. THE CURRENT TIMING FOR THE CHICAGO
METRO AREA FOR THIS BAND OF HEAVY PRECIPITATION LOOKS TO BE IN THE
12 TO 15 UTC TIME FRAME...AND AN COUPLE HOURS EARLIER ACROSS NORTH
CENTRAL ILLINOIS.
MODEL GUIDANCE CONTINUES TO SUGGEST THERMAL PROFILES WILL BE
MARGINAL FOR SNOWFALL...WITH MAX LAYER WET BULB TEMPERATURES FROM
ZERO TO +1 CELSIUS. HOWEVER...GIVEN THE LIKELIHOOD OF AN INTENSE
PRECIPITATION RATES WITHIN THIS AREA OF PRECIP...I FEEL THAT
SNOW...WITH SLEET IS STILL LIKELY TO BE THE PRIMARY PRECIPITATION
TYPES...ESPECIALLY NORTH OF INTERSTATES 80 AND 88...WHERE THE
STRONG MESOSCALE FORCING...AND HENCE MOST INTENSE DYNAMIC COLUMN
COOLING WILL BE MOST LIKELY. HOWEVER...A VERY SHORT PERIOD OF
RAIN/FREEZING RAIN IS ALSO POSSIBLE AS THE PRECIPITATION INITIALLY
FIGHTS WITH A WARM BUT DRY LAYER AROUND 850 MB...BUT EVAPORATIVE
COOLING SHOULD LEAD TO A RATHER QUICK CHANGE OVER TO SNOW. A QUICK
INCH OF SNOW IS POSSIBLE...ESPECIALLY ALONG AND NORTH OF I88. WE
WILL ISSUE AN SPS TO HIGHLIGHT THIS...AS IT APPEARS IT WILL BE A
QUICK BURST OF SNOW DURING THE MONDAY MORNING RUSH.
SOUTH OF INTERSTATE 80 SOME SNOW AND SLEET IS STILL
POSSIBLE...BUT RAIN...AND EVEN A BRIEF PERIOD OF FREEZING RAIN IS
EXPECTED INTO MONDAY MORNING...DUE TO SLIGHTLY WARMER MID-LEVEL
TEMPERATURES. SURFACE TEMPERATURES WILL BE HOVERING RIGHT AROUND
FREEZING INTO EARLY MONDAY MORNING...SO SOME MINOR ICING IS
POSSIBLE...BUT I DONT SEE THIS AS MUCH OF FREEZING RAIN EVENT.
PRECIPITATION SHOULD BE QUICK TO MOVE EAST OF THE AREA...BY MIDDAY TO
EARLY AFTERNOON. GUIDANCE INDICATES THAT THE MID LEVELS WILL DRY OUT
IN A HURRY LATER MONDAY MORNING/EARLY AFTERNOON. THUS IT APPEARS ANY
LINGERING PRECIP WILL BE IN THE FORM OF VERY LIGHT RAIN OR
DRIZZLE...AND GIVEN THAT TEMPERATURES SHOULD WARM WELL INTO THE 30S
TOMORROW AFTERNOON AHEAD OF THE APPROACHING COLD FRONT...FREEZING
WILL NOT BE AN ISSUE DURING THE AFTERNOON.
KJB
&&
.LONG TERM...
258 PM CST
MONDAY NIGHT THROUGH NEXT WEEKEND...
AN EXTENSION OF THE UPPER LOW FROM THE AFOREMENTIONED SYSTEM WILL
MOVE OVER THE AREA MONDAY EVENING ALONG WITH REINFORCED LOW-LEVEL
COLD ADVECTION AS A SECONDARY MORE CONTINENTAL COLD FRONT MOVES
SOUTHWARD THROUGH THE AREA. FORECAST LIFT IS DISJOINTED SO NOT
EXPECTING MUCH IF ANY PRECIPITATION...BUT DID ADD A CHANCE OF
DRIZZLE AND FLURRIES MONDAY EVENING. VERTICAL SATURATION PROFILES
REMAIN IFFY FOR ICE PRESENCE SO FELT COMFORTABLE MENTIONING EITHER
OR. WITH TEMPERATURES COOLING CANT RULE OUT FREEZING DRIZZLE IF SOME
PATCHY DRIZZLE WERE TO OCCUR...BUT AGAIN A LOW CHANCE.
AS THE SYSTEM MOVES EAST-SOUTHEAST ON TUESDAY IT WILL ABSORB A
SOUTHERN STREAM SYSTEM PRESENTLY ACROSS THE SOUTHERN
PLAINS...FORMING A DEEP OCCLUDING LOW ACROSS THE NEW ENGLAND REGION.
LONG RANGE GUIDANCE IS IN GOOD AGREEMENT WITH THIS. WITH BLOCKED
FLOW OVER THE NORTHERN/MID ATLANTIC...THIS LOW WILL MOVE LITTLE
THROUGH MIDWEEK...WITH THE OVERALL PATTERN BECOMING BLOCKED AND
CONSIDERABLY SLOWER ACROSS THE COUNTRY. THIS MEANS QUIET WEATHER FOR
OUR AREA FROM TUESDAY ONWARD. TEMPERATURES LOOK TO BE NEAR
NORMAL...MAYBE SLIGHTLY BELOW...DURING MIDWEEK.
A BUILDING UPPER RIDGE ACROSS THE ROCKIES DURING MIDWEEK WILL
INCH/LEAN EASTWARD...HOWEVER THE LOW-LEVEL THERMAL RIDGE WILL LAG
THIS. WHILE HEIGHTS WILL BE WELL ABOVE NORMAL OVER THE AREA...THE
GREATEST HEIGHT AND THERMAL ANOMALIES LOOK TO REMAIN TO THE WEST AND
NORTHWEST OF THE AREA ON ENSEMBLE GUIDANCE AND THE TREND HAS BEEN
THIS WAY. TEMPERATURES ARE STILL ON THEIR WAY TO ABOVE NORMAL WITH
THE CHANCE OF HAVING NEXT WEEKEND IN THE 50S...BUT RIGHT NOW WITHOUT
STRONG LOW-LEVEL WARM ADVECTION THE MAGNITUDE MAY BE HINDERED SOME.
DO THINK THE GFS IS TOO ROBUST ON LOW-LEVEL MOISTURE OVER THE
WEEKEND SO HAVE LEANED MORE TOWARD THE MORE SUNNY ECMWF /ESPECIALLY
FOR SATURDAY/. THE ECMWF HAS HIGHS IN THE MID-UPPER 40S. GIVEN THE
PATTERN...ANY PRECIPITATION CHANCES ARE LIKELY TO SLOW FURTHER SO
HAVE BACKED ANY UP UNTIL SUNDAY NIGHT.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* PERIOD OF MIXED PRECIPITATION MONDAY MORNING. LIKELY BEGINNING AS
LIGHT -FZRA/IP MIX THEN CHANGING TO BRIEF SN/IP WITH SOME ACCUM
PSBL. CIGS/VIS TO DETERIORATE QUICKLY TO MVFR/IFR AFTER ONSET OF
PCPN. MVFR...PSBLY IFR CIG LIKELY TO LINGER THRU THE REMAINDER
OF THE DAY WITH OCNL LIGHT RAIN OR DRIZZLE.
* SOUTHEAST WINDS AROUND 10 KT THIS EVENING BECOMING SOUTH
OVERNIGHT. SOUTH WINDS BECOME SOUTHWEST EARLY AFTN...AND WEST
AFTER SUNSET WITH SOME GUSTS 15-20 KT.
RATZER
//DISCUSSION...UPDATED 00Z...
FAIRLY VIGOROUS WEATHER DISTURBANCE MOVING THROUGH THE NORTHERN
PLAINS EARLY THIS EVENING...AND THIS SYSTEM WILL CROSS THE UPPER
MIDWEST AND MOVE TO THE WESTERN GREAT LAKES THROUGH MONDAY MORNING.
THINKING REMAINS VERY CONSISTENT FROM EARLIER FORECAST ON
DEVELOPING SCENARIO OF GRADUALLY LOWERING VFR CEILINGS TONIGHT...
WITH PRECIPITATION EVENTUALLY DEVELOPING FROM THE WEST DURING THE
PRE-DAWN HOURS IN THE FORM OF A -FZRA/IP/SN MIX. THE STRENGTH OF
LIFT SUGGESTS A PERIOD OF MODERATE OR BRIEFLY HEAVIER PRECIP IN
THE FORM OF A SN/IP MIX IS POSSIBLE DURING THE EARLY MORNING
HOURS...BEFORE TAPERING OFF TO -RA/SN MIX AND THEN LINGERING
MAINLY AS -DZ THROUGH THE AFTERNOON WITH SURFACE TEMPS WARMING
ABOVE FREEZING.
MVFR/BRIEF IFR CIGS AND VIS EXPECTED TO DEVELOP AS PRECIPITATION
INTENSIFIES EARLY. MODEL FORECASTS INDICATE LOW LEVELS WILL REMAIN
FAIRLY MOIST AFTER LIFT/MID-LEVEL SATURATION WANES BY LATE
MORNING. SOME GUIDANCE HINTS AT IFR CIGS LINGERING THROUGH THE
AFTERNOON WHILE OTHERS IMPROVE TO LOW-END MVFR AFTER HEAVIER
PRECIPITATION ENDS. CONFIDENCE IS LOW SO HAVE MAINTAINED A
FORECAST CIG AT THE IFR/MVFR BREAK POINT AT THIS TIME...THOUGH IFR
CIGS LINGERING FOR SEVERAL HOURS INTO THE MIDDAY AND AFTERNOON
HOURS IS A POSSIBILITY.
SOUTHEAST WINDS AROUND 10 KT THIS EVENING WILL VEER TO THE SOUTH
TONIGHT AS LOW PRESSURE MOVES EAST ALONG THE CANADIAN BORDER.
WINDS ARE THEN EXPECTED TO SHIFT SOUTHWEST NEAR 10 KT AROUND MID-
DAY AS OCCLUDING WARM FRONT MOVES THROUGH...THEN BECOME WESTERLY
WITH SOME GUSTS 15-20 EARLY MONDAY EVENING BEHIND COLD FRONT.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* HIGH CONFIDENCE IN WIND TRENDS THROUGH PERIOD...AND WITH WITH
CIG/VIS CONDITIONS THROUGH MIDNIGHT/06Z TONIGHT.
* MEDIUM-HIGH CONFIDENCE IN BAND OF MIXED PCPN OCCURRING MONDAY
MORNING WITH A PERIOD OF IFR CONDITIONS. MEDIUM CONFIDENCE IN
DETAILS OF TIMING AND PCPN TYPE EVOLUTION. LOW CONFIDENCE WITH
SIGNIFICANT FZRA.
* MEDIUM-LOW CONFIDENCE IN CIG/VIS BEYOND LATE MORNING.
RATZER
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
TUESDAY...MVFR CIGS PSBL EARLY...THEN MAINLY VFR. LAKE EFFECT
RAIN/SNOW SHOWERS EAST OF ORD/MDW OVER LAKE. NW WINDS BECOMING N.
WEDNESDAY...VFR. N WINDS.
THURSDAY...VFR. W WINDS BECOMING WSW.
FRIDAY...MAINLY VFR...THOUGH MVFR CIGS PSBL. SW WINDS.
SATURDAY...MAINLY VFR...THOUGH MVFR CIGS PSBL. S WINDS.
RATZER
&&
.MARINE...
203 PM CST
SOUTHEAST TO SOUTH WINDS WILL CONTINUE TO INCREASE TONIGHT AHEAD OF
QUICK MOVING LOW PRESSURE ACROSS THE UPPER MIDWEST...INCLUDING
POSSIBLY TEMPORARY GALES ACROSS THE FAR NORTH. THE SOMEWHAT ONSHORE
FLOW TONIGHT INTO NORTHEAST ILLINOIS...MAINLY NORTH OF
CHICAGO...STILL LOOKS TO BRING SMALL CRAFT ADVISORY CONDITIONS THERE
INTO EARLY MONDAY MORNING. AS THE LOW TRACKS FROM LAKE SUPERIOR TO
LAKE HURON MONDAY AND MONDAY NIGHT...WINDS WILL TURN TO WEST ON
MONDAY EVENING AND THEN NORTHWEST LATE MONDAY NIGHT AND FINALLY TO
NORTH BY MIDDAY TUESDAY. WIDESPREAD 30 KT WINDS ARE EXPECTED
TUESDAY IN THIS COLD AIR ADVECTION. THE WEATHER PATTERN IS
FORECAST TO BECOME VERY BLOCKED FOR THE LATTER HALF OF THE
WEEK...WITH THE LAKE LOCKED BETWEEN A RIDGE TO ITS IMMEDIATE WEST
AND A LOW OVER THE NORTHEAST. THIS MEANS GENERALLY 10-15 KT
NORTHWEST TO WEST WINDS.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO NORTHERLY
IS UNTIL 10 AM MONDAY.
&&
$$
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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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[top]
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
844 PM CST Sun Dec 7 2014
.UPDATE...
ISSUED AT 835 PM CST SUN DEC 7 2014
Impressive shortwave seen on water vapor loop over eastern North
Dakota this evening tracking east-southeast. At the surface, a
large area of high pressure near Lake Erie will continue to drift
slowly away from our area. However, in its wake, there was quite
a bit of dry air in the lower levels as seen on the 00z ILX
sounding. As winds turn more southerly later tonight we do expect
a gradual increase in moisture at the mid and eventually lower
levels of the atmosphere, especially by dawn Monday. With the
stronger upper forcing expected to remain well north of our area
Monday morning, we expect the more significant wintry precip to
stay north of the forecast area as well. However, we will see a
brief period of rain develop after 1 or 2 am across the west and
then track east over the remainder of the area by dawn.
Except for the far northern counties, forecast soundings were
trending a bit warmer late tonight and first thing Monday morning
just ahead of a surface trof with temperatures expected to edge up
into the mid or upper 30s with the warmest readings over the
central and south. Soundings near Galesburg east thru Lacon and
southeast to just north of Bloomington indicate a narrow window of
opportunity for a little sleet or light freezing rain before going
over to rain by morning. Will continue to hold on to that idea
over the far north but based on the RAP, HRRR and latest NAM-WRF
soundings it appears the majority of the area will see mainly the
threat for rain overnight and into Monday morning ahead of the
surface trof/cold front.
Other than some minor adjustments to precip type over the far
north, the current forecast seems to be handling the situation
well for the overnight hours. We should have an updated ZFP out
by 900 pm.
&&
.SHORT TERM...(Tonight)
ISSUED AT 304 PM CST SUN DEC 7 2014
Mid and high clouds are expansive across the forecast area this
afternoon, although some patches of stratocumulus have been
developing. Larger shield of clouds around 1500 feet starting to
cross the Missouri/Illinois border as well. Water vapor imagery
showing the incoming clipper system quite nicely over the Dakotas.
Latest surface map shows the low center over northern North Dakota,
and its trailing cold front into central Nebraska and western
Kansas.
Main concern is with precipitation types across the north. Still
appears that the precipitation in our area will hold off until after
midnight, and not reach areas east of I-57 until sunrise. The
remainder of the morning model suite has arrived, and all are
generally trending warmer ahead of the incoming clipper. The NAM
and RAP are most prominent with the 850 mb warm nose, around +4 to
+5C, and suggest all rain even in the far north. The GFS, ECMWF and
Canadian models with a more modest +1 to +3C. These all indicate
surface temperatures above freezing as well, but would indicate a
bit of sleet potential as well. Have leaned a bit more on the warmer
side of the guidance and kept it mostly rain, but included a slight
chance of freezing rain from around Champaign northwest through
Bloomington to Minonk. Surface temperatures will remain borderline
with the ice potential, but lows around 33-34 degrees will be common
in much of the forecast area.
&&
.LONG TERM...(Monday through Sunday)
ISSUED AT 304 PM CST SUN DEC 7 2014
The initial shortwave feature associated with the clipper system
will cross the central IL forecast area by mid afternoon, bringing
the best lift and precipitation with the system. Models over the
past day have trended upward with precipitation amounts and now
yield a consensus of a few hundredths to a tenth of an inch.
Precipitation type could linger as freezing rain from around
Danville northwestward until around 8 a.m. but surface temperatures
will quickly rise above freezing to yield all rain through the day.
Subsidence aloft will follow the initial shortwave causing
precipitation to diminish from west to east late morning through
afternoon. Shallow stratus looks to continue into the evening as
cold advection in northwest winds push into the region. Model
soundings indicate the moisture trapped below a subsidence inversion
will be shallow enough that any precipitation would likely be
drizzle, although some potential for snow flurries with little
accumulation exists.
Below normal temperatures in NW flow will continue for midweek. A
deepening low over the east coast will likely cause a blocked
pattern with a slowly moving ridge over the plains. Models have been
inconsistent with handling next weekend but have trended forecast
toward the ECMWF solution which holds the ridge further west and
looks more reasonable. As a result, will hold drier and slightly
cooler temperatures longer into the weekend.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
ISSUED AT 520 PM CST SUN DEC 7 2014
Latest surface observations continue to indicate some patchy MVFR
cigs drifting slowly northwest from around AAA and south of BMI
to PIA. Short term models indicate the band will continue to shift
north-northwest thru the PIA area over the next several hours with
a decrease in the coverage further south and east thru 00z. Elsewhere,
expecting some mid and high level clouds thru 07z before our next
weather system brings in low MVFR cigs from west to east starting
at 08z and continuing thru most of Monday with periods of light
rain...especially during the morning hours. Forecast soundings
showing temperatures even across our northern TAF sites at or just
above freezing, so at this time expecting mainly rain to fall but
we could see a brief period of light sleet or freezing rain at KBMI
for about an hour after the precip begins, which looks to be in the
09z-11z time frame. Surface winds will be east to southeast tonight
at 7 to 12 kts, with winds veering into the southwest and west by
late Monday morning into the aftenoon hours as a cold front sweeps
across the forecast area. Wind speeds should range from 10 to 15 kts
during the day.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Smith
SHORT TERM...Geelhart
LONG TERM...Onton
AVIATION...Smith
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
549 PM CST SUN DEC 7 2014
.SHORT TERM...
TONIGHT THROUGH MONDAY... 314 PM CST
THE MAIN WEATHER CONCERN FOR TONIGHT INTO MONDAY IS THE QUICK HIT
OF A WINTERY MIX LATE TONIGHT INTO MONDAY MORNING...WITH THE
POTENTIAL OF BRIEF PERIOD OF A HEAVY BURST OF SNOW ACROSS FAR
NORTHERN ILLINOIS EARLY MONDAY MORNING DURING THE MORNING RUSH.
WATER VAPOR IMAGERY INDICATES OUR STORM SYSTEM OF INTEREST DIGGING
EAST-SOUTHEASTWARD ACROSS THE NORTHERN HIGH PLAINS. THE ASSOCIATED
AREA OF SURFACE LOW PRESSURE IS EXPECTED TO TRACK QUICKLY ALONG OR
NEAR THE CANADIAN BORDER THROUGH TUESDAY. WARM AIR
ADVECTION/ISENTROPIC ASCENT IS ALREADY RAMPING UP ACROSS THE AREA
OUT AHEAD OF THIS FEATURE...AND REGIONAL RADAR TRENDS ARE BEGINNING
TO SHOW PRECIPITATION DEVELOPING TO OUR WEST-NORTHWEST IN ASSOCIATION
WITH THE APPROACHING SURFACE FRONTAL BOUNDARY.
THE COMBINATION OF GOOD LARGE SCALE FORCING (Q-VECTOR CONVERGENCE)
ASSOCIATED WITH THE APPROACHING MID LEVEL SHORT WAVE ENERGY...ALONG
WITH WHAT APPEARS MAY END UP BEING A RATHER STOUT BAND OF MID LEVEL
FRONTOGENESIS...SHOULD PROVIDE A SHORT...BUT POTENTIALLY INTENSE
PERIOD OF PRECIPITATION ACROSS NORTHERN ILLINOIS/NORTHWESTERN
INDIANA EARLY MONDAY MORNING. MODEL SOUNDINGS ACROSS THE AREA ALL
INDICATE THE PRESENCE OF SOME VERY IMPRESSIVE MID LEVEL LAPSE RATES
(UP AROUND 7 DEGREES C/KM IN THE 700-500 MB LAYER) DURING THE PERIOD
OF MAXIMUM FORCING FOR ASCENT. IN ADDITION...CROSS SECTIONS ACROSS
NORTHERN ILLINOIS ALSO INDICATE THE PRESENCE OF NEGATIVE EPV...WITH
FOLDING THETA E SURFACES IN THE 500 TO 700 MB LAYER. THIS ALL
POINTS TO THE LIKELIHOOD OF A SHORT...BUT POTENTIALLY INTENSE BAND OF
PRECIPITATION DURING THE MORNING RUSH ACROSS NORTHERN
ILLINOIS/NORTHWESTERN INDIANA. THE CURRENT TIMING FOR THE CHICAGO
METRO AREA FOR THIS BAND OF HEAVY PRECIPITATION LOOKS TO BE IN THE
12 TO 15 UTC TIME FRAME...AND AN COUPLE HOURS EARLIER ACROSS NORTH
CENTRAL ILLINOIS.
MODEL GUIDANCE CONTINUES TO SUGGEST THERMAL PROFILES WILL BE
MARGINAL FOR SNOWFALL...WITH MAX LAYER WET BULB TEMPERATURES FROM
ZERO TO +1 CELSIUS. HOWEVER...GIVEN THE LIKELIHOOD OF AN INTENSE
PRECIPITATION RATES WITHIN THIS AREA OF PRECIP...I FEEL THAT
SNOW...WITH SLEET IS STILL LIKELY TO BE THE PRIMARY PRECIPITATION
TYPES...ESPECIALLY NORTH OF INTERSTATES 80 AND 88...WHERE THE
STRONG MESOSCALE FORCING...AND HENCE MOST INTENSE DYNAMIC COLUMN
COOLING WILL BE MOST LIKELY. HOWEVER...A VERY SHORT PERIOD OF
RAIN/FREEZING RAIN IS ALSO POSSIBLE AS THE PRECIPITATION INITIALLY
FIGHTS WITH A WARM BUT DRY LAYER AROUND 850 MB...BUT EVAPORATIVE
COOLING SHOULD LEAD TO A RATHER QUICK CHANGE OVER TO SNOW. A QUICK
INCH OF SNOW IS POSSIBLE...ESPECIALLY ALONG AND NORTH OF I88. WE
WILL ISSUE AN SPS TO HIGHLIGHT THIS...AS IT APPEARS IT WILL BE A
QUICK BURST OF SNOW DURING THE MONDAY MORNING RUSH.
SOUTH OF INTERSTATE 80 SOME SNOW AND SLEET IS STILL
POSSIBLE...BUT RAIN...AND EVEN A BRIEF PERIOD OF FREEZING RAIN IS
EXPECTED INTO MONDAY MORNING...DUE TO SLIGHTLY WARMER MID-LEVEL
TEMPERATURES. SURFACE TEMPERATURES WILL BE HOVERING RIGHT AROUND
FREEZING INTO EARLY MONDAY MORNING...SO SOME MINOR ICING IS
POSSIBLE...BUT I DONT SEE THIS AS MUCH OF FREEZING RAIN EVENT.
PRECIPITATION SHOULD BE QUICK TO MOVE EAST OF THE AREA...BY MIDDAY TO
EARLY AFTERNOON. GUIDANCE INDICATES THAT THE MID LEVELS WILL DRY OUT
IN A HURRY LATER MONDAY MORNING/EARLY AFTERNOON. THUS IT APPEARS ANY
LINGERING PRECIP WILL BE IN THE FORM OF VERY LIGHT RAIN OR
DRIZZLE...AND GIVEN THAT TEMPERATURES SHOULD WARM WELL INTO THE 30S
TOMORROW AFTERNOON AHEAD OF THE APPROACHING COLD FRONT...FREEZING
WILL NOT BE AN ISSUE DURING THE AFTERNOON.
KJB
&&
.LONG TERM...
258 PM CST
MONDAY NIGHT THROUGH NEXT WEEKEND...
AN EXTENSION OF THE UPPER LOW FROM THE AFOREMENTIONED SYSTEM WILL
MOVE OVER THE AREA MONDAY EVENING ALONG WITH REINFORCED LOW-LEVEL
COLD ADVECTION AS A SECONDARY MORE CONTINENTAL COLD FRONT MOVES
SOUTHWARD THROUGH THE AREA. FORECAST LIFT IS DISJOINTED SO NOT
EXPECTING MUCH IF ANY PRECIPITATION...BUT DID ADD A CHANCE OF
DRIZZLE AND FLURRIES MONDAY EVENING. VERTICAL SATURATION PROFILES
REMAIN IFFY FOR ICE PRESENCE SO FELT COMFORTABLE MENTIONING EITHER
OR. WITH TEMPERATURES COOLING CANT RULE OUT FREEZING DRIZZLE IF SOME
PATCHY DRIZZLE WERE TO OCCUR...BUT AGAIN A LOW CHANCE.
AS THE SYSTEM MOVES EAST-SOUTHEAST ON TUESDAY IT WILL ABSORB A
SOUTHERN STREAM SYSTEM PRESENTLY ACROSS THE SOUTHERN
PLAINS...FORMING A DEEP OCCLUDING LOW ACROSS THE NEW ENGLAND REGION.
LONG RANGE GUIDANCE IS IN GOOD AGREEMENT WITH THIS. WITH BLOCKED
FLOW OVER THE NORTHERN/MID ATLANTIC...THIS LOW WILL MOVE LITTLE
THROUGH MIDWEEK...WITH THE OVERALL PATTERN BECOMING BLOCKED AND
CONSIDERABLY SLOWER ACROSS THE COUNTRY. THIS MEANS QUIET WEATHER FOR
OUR AREA FROM TUESDAY ONWARD. TEMPERATURES LOOK TO BE NEAR
NORMAL...MAYBE SLIGHTLY BELOW...DURING MIDWEEK.
A BUILDING UPPER RIDGE ACROSS THE ROCKIES DURING MIDWEEK WILL
INCH/LEAN EASTWARD...HOWEVER THE LOW-LEVEL THERMAL RIDGE WILL LAG
THIS. WHILE HEIGHTS WILL BE WELL ABOVE NORMAL OVER THE AREA...THE
GREATEST HEIGHT AND THERMAL ANOMALIES LOOK TO REMAIN TO THE WEST AND
NORTHWEST OF THE AREA ON ENSEMBLE GUIDANCE AND THE TREND HAS BEEN
THIS WAY. TEMPERATURES ARE STILL ON THEIR WAY TO ABOVE NORMAL WITH
THE CHANCE OF HAVING NEXT WEEKEND IN THE 50S...BUT RIGHT NOW WITHOUT
STRONG LOW-LEVEL WARM ADVECTION THE MAGNITUDE MAY BE HINDERED SOME.
DO THINK THE GFS IS TOO ROBUST ON LOW-LEVEL MOISTURE OVER THE
WEEKEND SO HAVE LEANED MORE TOWARD THE MORE SUNNY ECMWF /ESPECIALLY
FOR SATURDAY/. THE ECMWF HAS HIGHS IN THE MID-UPPER 40S. GIVEN THE
PATTERN...ANY PRECIPITATION CHANCES ARE LIKELY TO SLOW FURTHER SO
HAVE BACKED ANY UP UNTIL SUNDAY NIGHT.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* PERIOD OF MIXED PRECIPITATION MONDAY MORNING. LIKELY BEGINNING AS
LIGHT -FZRA/IP MIX THEN CHANGING TO BRIEF SN/IP WITH SOME ACCUM
PSBL. CIGS/VIS TO DETERIORATE QUICKLY TO MVFR/IFR AFTER ONSET OF
PCPN. MVFR...PSBLY IFR CIG LIKELY TO LINGER THRU THE REMAINDER
OF THE DAY WITH OCNL LIGHT RAIN OR DRIZZLE.
* SOUTHEAST WINDS AROUND 10 KT THIS EVENING BECOMING SOUTH
OVERNIGHT. SOUTH WINDS BECOME SOUTHWEST EARLY AFTN...AND WEST
AFTER SUNSET WITH SOME GUSTS 15-20 KT.
RATZER
//DISCUSSION...UPDATED 00Z...
FAIRLY VIGOROUS WEATHER DISTURBANCE MOVING THROUGH THE NORTHERN
PLAINS EARLY THIS EVENING...AND THIS SYSTEM WILL CROSS THE UPPER
MIDWEST AND MOVE TO THE WESTERN GREAT LAKES THROUGH MONDAY MORNING.
THINKING REMAINS VERY CONSISTENT FROM EARLIER FORECAST ON
DEVELOPING SCENARIO OF GRADUALLY LOWERING VFR CEILINGS TONIGHT...
WITH PRECIPITATION EVENTUALLY DEVELOPING FROM THE WEST DURING THE
PRE-DAWN HOURS IN THE FORM OF A -FZRA/IP/SN MIX. THE STRENGTH OF
LIFT SUGGESTS A PERIOD OF MODERATE OR BRIEFLY HEAVIER PRECIP IN
THE FORM OF A SN/IP MIX IS POSSIBLE DURING THE EARLY MORNING
HOURS...BEFORE TAPERING OFF TO -RA/SN MIX AND THEN LINGERING
MAINLY AS -DZ THROUGH THE AFTERNOON WITH SURFACE TEMPS WARMING
ABOVE FREEZING.
MVFR/BRIEF IFR CIGS AND VIS EXPECTED TO DEVELOP AS PRECIPITATION
INTENSIFIES EARLY. MODEL FORECASTS INDICATE LOW LEVELS WILL REMAIN
FAIRLY MOIST AFTER LIFT/MID-LEVEL SATURATION WANES BY LATE
MORNING. SOME GUIDANCE HINTS AT IFR CIGS LINGERING THROUGH THE
AFTERNOON WHILE OTHERS IMPROVE TO LOW-END MVFR AFTER HEAVIER
PRECIPITATION ENDS. CONFIDENCE IS LOW SO HAVE MAINTAINED A
FORECAST CIG AT THE IFR/MVFR BREAK POINT AT THIS TIME...THOUGH IFR
CIGS LINGERING FOR SEVERAL HOURS INTO THE MIDDAY AND AFTERNOON
HOURS IS A POSSIBILITY.
SOUTHEAST WINDS AROUND 10 KT THIS EVENING WILL VEER TO THE SOUTH
TONIGHT AS LOW PRESSURE MOVES EAST ALONG THE CANADIAN BORDER.
WINDS ARE THEN EXPECTED TO SHIFT SOUTHWEST NEAR 10 KT AROUND MID-
DAY AS OCCLUDING WARM FRONT MOVES THROUGH...THEN BECOME WESTERLY
WITH SOME GUSTS 15-20 EARLY MONDAY EVENING BEHIND COLD FRONT.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* HIGH CONFIDENCE IN WIND TRENDS THROUGH PERIOD...AND WITH WITH
CIG/VIS CONDITIONS THROUGH MIDNIGHT/06Z TONIGHT.
* MEDIUM-HIGH CONFIDENCE IN BAND OF MIXED PCPN OCCURRING MONDAY
MORNING WITH A PERIOD OF IFR CONDITIONS. MEDIUM CONFIDENCE IN
DETAILS OF TIMING AND PCPN TYPE EVOLUTION. LOW CONFIDENCE WITH
SIGNIFICANT FZRA.
* MEDIUM-LOW CONFIDENCE IN CIG/VIS BEYOND LATE MORNING.
RATZER
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
TUESDAY...MVFR CIGS PSBL EARLY...THEN MAINLY VFR. LAKE EFFECT
RAIN/SNOW SHOWERS EAST OF ORD/MDW OVER LAKE. NW WINDS BECOMING N.
WEDNESDAY...VFR. N WINDS.
THURSDAY...VFR. W WINDS BECOMING WSW.
FRIDAY...MAINLY VFR...THOUGH MVFR CIGS PSBL. SW WINDS.
SATURDAY...MAINLY VFR...THOUGH MVFR CIGS PSBL. S WINDS.
RATZER
&&
.MARINE...
203 PM CST
SOUTHEAST TO SOUTH WINDS WILL CONTINUE TO INCREASE TONIGHT AHEAD OF
QUICK MOVING LOW PRESSURE ACROSS THE UPPER MIDWEST...INCLUDING
POSSIBLY TEMPORARY GALES ACROSS THE FAR NORTH. THE SOMEWHAT ONSHORE
FLOW TONIGHT INTO NORTHEAST ILLINOIS...MAINLY NORTH OF
CHICAGO...STILL LOOKS TO BRING SMALL CRAFT ADVISORY CONDITIONS THERE
INTO EARLY MONDAY MORNING. AS THE LOW TRACKS FROM LAKE SUPERIOR TO
LAKE HURON MONDAY AND MONDAY NIGHT...WINDS WILL TURN TO WEST ON
MONDAY EVENING AND THEN NORTHWEST LATE MONDAY NIGHT AND FINALLY TO
NORTH BY MIDDAY TUESDAY. WIDESPREAD 30 KT WINDS ARE EXPECTED
TUESDAY IN THIS COLD AIR ADVECTION. THE WEATHER PATTERN IS
FORECAST TO BECOME VERY BLOCKED FOR THE LATTER HALF OF THE
WEEK...WITH THE LAKE LOCKED BETWEEN A RIDGE TO ITS IMMEDIATE WEST
AND A LOW OVER THE NORTHEAST. THIS MEANS GENERALLY 10-15 KT
NORTHWEST TO WEST WINDS.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO NORTHERLY IS UNTIL 10 AM MONDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
523 PM CST Sun Dec 7 2014
.SHORT TERM...(Tonight)
ISSUED AT 304 PM CST SUN DEC 7 2014
Mid and high clouds are expansive across the forecast area this
afternoon, although some patches of stratocumulus have been
developing. Larger shield of clouds around 1500 feet starting to
cross the Missouri/Illinois border as well. Water vapor imagery
showing the incoming clipper system quite nicely over the Dakotas.
Latest surface map shows the low center over northern North Dakota,
and its trailing cold front into central Nebraska and western
Kansas.
Main concern is with precipitation types across the north. Still
appears that the precipitation in our area will hold off until after
midnight, and not reach areas east of I-57 until sunrise. The
remainder of the morning model suite has arrived, and all are
generally trending warmer ahead of the incoming clipper. The NAM
and RAP are most prominent with the 850 mb warm nose, around +4 to
+5C, and suggest all rain even in the far north. The GFS, ECMWF and
Canadian models with a more modest +1 to +3C. These all indicate
surface temperatures above freezing as well, but would indicate a
bit of sleet potential as well. Have leaned a bit more on the warmer
side of the guidance and kept it mostly rain, but included a slight
chance of freezing rain from around Champaign northwest through
Bloomington to Minonk. Surface temperatures will remain borderline
with the ice potential, but lows around 33-34 degrees will be common
in much of the forecast area.
&&
.LONG TERM...(Monday through Sunday)
ISSUED AT 304 PM CST SUN DEC 7 2014
The initial shortwave feature associated with the clipper system
will cross the central IL forecast area by mid afternoon, bringing
the best lift and precipitation with the system. Models over the
past day have trended upward with precipitation amounts and now
yield a consensus of a few hundredths to a tenth of an inch.
Precipitation type could linger as freezing rain from around
Danville northwestward until around 8 a.m. but surface temperatures
will quickly rise above freezing to yield all rain through the day.
Subsidence aloft will follow the initial shortwave causing
precipitation to diminish from west to east late morning through
afternoon. Shallow stratus looks to continue into the evening as
cold advection in northwest winds push into the region. Model
soundings indicate the moisture trapped below a subsidence inversion
will be shallow enough that any precipitation would likely be
drizzle, although some potential for snow flurries with little
accumulation exists.
Below normal temperatures in NW flow will continue for midweek. A
deepening low over the east coast will likely cause a blocked
pattern with a slowly moving ridge over the plains. Models have been
inconsistent with handling next weekend but have trended forecast
toward the ECMWF solution which holds the ridge further west and
looks more reasonable. As a result, will hold drier and slightly
cooler temperatures longer into the weekend.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
ISSUED AT 520 PM CST SUN DEC 7 2014
Latest surface observations continue to indicate some patchy MVFR
cigs drifting slowly northwest from around AAA and south of BMI
to PIA. Short term models indicate the band will continue to shift
north-northwest thru the PIA area over the next several hours with
a decrease in the coverage further south and east thru 00z. Elsewhere,
expecting some mid and high level clouds thru 07z before our next
weather system brings in low MVFR cigs from west to east starting
at 08z and continuing thru most of Monday with periods of light
rain...especially during the morning hours. Forecast soundings
showing temperatures even across our northern TAF sites at or just
above freezing, so at this time expecting mainly rain to fall but
we could see a brief period of light sleet or freezing rain at KBMI
for about an hour after the precip begins, which looks to be in the
09z-11z time frame. Surface winds will be east to southeast tonight
at 7 to 12 kts, with winds veering into the southwest and west by
late Monday morning into the aftenoon hours as a cold front sweeps
across the forecast area. Wind speeds should range from 10 to 15 kts
during the day.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Geelhart
LONG TERM...Onton
AVIATION...Smith
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
405 PM CST SAT DEC 6 2014
.SHORT TERM...
257 PM CST
NORTHEAST FLOW OVER THE REGION AHEAD OF HIGH PRESSURE HAS
CONTINUED TO EASE IN DRIER AIR. MID-AFTERNOON VISIBLE SATELLITE
IMAGERY REVEALS ONLY SOME DEPARTING STRATUS ACROSS THE FAR
SOUTHERN FORECAST AREA...AND SOME REMAINING RIBBONS OF LAKE EFFECT
CLOUDS INTO FAR NORTHEAST IL AND NORTHWEST IN. WATER VAPOR IMAGERY
CONFIRMS DRIER MID-LEVEL AIR AND SUPPRESSION MOVING OVERHEAD WHICH
SHOULD MITIGATE CLOUDS THIS EVENING...OUTSIDE OF A FEW LAKE
EFFECT CLOUDS INCHING WESTWARD OVER NORTHERN IL WITHIN THE
VEERING FLOW. A LIGHT WIND COMPONENT WILL REMAIN THIS EVENING
ALTHOUGH AS THE 1039 MB HIGH PASSES ACROSS WI...THE WINDS WILL
LIKELY BECOME LIGHT AND VARIABLE ALLOWING FOR FURTHER TEMPERATURE
DROP. DEW POINTS ARE SEVERAL DEGREES ABOVE THIS AT PRESENT...BUT
NOT REALLY A PATTERN WHERE WOULD EXPECT FOG...ESPECIALLY ANYTHING
OF NOTE.
SOUTHEAST WINDS WILL SETTLE IN ON SUNDAY WITH THE DEPARTING HIGH
AND LOW PRESSURE MARCHING EASTWARD NEAR THE NORTHERN CONUS BORDER.
HIGH CLOUDS LOOK TO GRADUALLY INCREASE/THICKEN DURING THE
AFTERNOON. GIVEN HIGHS TODAY REACHED THE UPPER 30S TO LOWER 40S
WOULD ENVISION SUNDAY BEING IN THE SAME ARENA IF CLOUDS DO NOT
THICKEN EARLIER THAN FORECAST.
MTF
&&
.LONG TERM...
315 PM CST
LONG TERM...SUNDAY NIGHT THROUGH SATURDAY...
OVERALL THE EXTENDED PERIOD WILL CONTINUE TO FEATURE A FAIRLY
PROGRESSIVE WEATHER PATTERN...WITH ONLY A QUICK HIT OF SOME COLDER
AIR FOR LATE TUESDAY INTO WEDNESDAY. THE MAIN FORECAST CONCERNS
DURING THE PERIOD WILL BE THE INCREASING POTENTIAL OF A QUICK HIT OF
WINTERY WEATHER LATE SUNDAY NIGHT INTO MONDAY MORNING.
WATER VAPOR IMAGERY INDICATES THE NEXT PACIFIC SYSTEM OF
INTEREST...NOW SHIFTING ONSHORE ACROSS WASHINGTON STATE. THIS
FEATURE...ALONG WITH AN ASSOCIATED AREA OF LOW PRESSURE IS EXPECTED
TO TRACK QUICKLY ALONG OR NEAR THE CANADIAN INTERNATIONAL
BORDER SUNDAY THROUGH TUESDAY. TYPICALLY THIS TYPE OF TRACK IS NOT
GOOD FOR MUCH PRECIPITATION FOR THE AREA...AND OVERALL THIS WILL BE
THE CASE. HOWEVER...IT APPEARS THAT QUICK HIT OF WINTRY PRECIPITATION
IS LIKELY LATE SUNDAY NIGHT INTO EARLY MONDAY MORNING.
A PERIOD OF INCREASING ISENTROPIC ASCENT COMBINED WITH SOME DECENT
Q-VECTOR CONVERGENCE...ASSOCIATED WITH ADDITIONAL SHORTWAVE ENERGY
DIGGING SOUTHEASTWARD TOWARDS THAT AREA LATER SUNDAY NIGHT...SHOULD
PROVIDE A SHORT PERIOD OF FORCING SUPPORTIVE OF PRECIPITATION ACROSS
NORTHERN ILLINOIS/NORTHWESTERN INDIANA. OVERALL...THIS STILL APPEARS
TO BE A SMALL EVENT FOR THE AREA. HOWEVER...IT APPEARS THAT A
STRENGTHENING BAROCLINIC ZONE ALONG AN OCCLUDED FRONTAL BOUNDARY MAY
PROVIDE A SHORT PERIOD OF ENHANCED MESOSCALE FORCING...SUPPORTIVE A
SHORT PERIOD OF HEAVIER PRECIPITATION...ESPECIALLY GIVEN THE PRESENCE
OF STEEP MID LEVEL LAPSE RATES INTO MONDAY MORNING. THUS...IT
APPEARS THAT BAND OF PRECIPITATION...POSSIBLY ONLY LASTING A COUPLE
HOURS AT ANY GIVEN LOCATION...IS LIKELY TO MOVE ACROSS THE AREA IN
TIME FOR THE MONDAY MORNING RUSH.
PRECIP TYPE STILL APPEARS TO BE TRICKY WITH THIS ACTIVITY EARLY
MONDAY. ASIDE FOR THE NAM SOLUTION...MOST MODEL DERIVED SOUNDINGS
ACROSS NORTHERN ILLINOIS INDICATE MAX LAYER TEMPERATURES OF ONLY +1
TO +1.5 DEGREES CELSIUS...WHICH WOULD SUGGEST ONLY PARTIAL MELTING OF
DENDRITES...POSSIBLY RESULTING IN SNOW AND SLEET PRECIP TYPES ACROSS
MOST OF FAR NORTHERN ILLINOIS. ALSO...GIVEN THAT THERE COULD BE SOME
ENHANCE PRECIP RATES WITH THIS ACTIVITY...AS WELL AS THE FACT THAT
EVAPORATIVE COOLING POTENTIAL SUNDAY NIGHT WILL BE HIGH...IT APPEARS
PRUDENT TO MENTION MORE OF A SNOW AND SLEET SCENARIO ACROSS FAR
NORTHERN ILLINOIS RATHER THAN FREEZING RAIN AT THIS POINT. THEREFORE...I
HAVE TRENDED THE FORECAST IN THIS DIRECTION.
ACCUMULATIONS ARE ALSO POSSIBLE WITH THIS ACTIVITY. IN FACT...SOME
AREAS COULD GET A QUICK INCH OF SNOW...IF IT FALLS PRIMARILY AS SUCH.
AT THIS TIME IT APPEARS THE BEST POTENTIAL FOR THIS APPEARS TO BE
ROUGHLY ALONG AND NORTH OF I-88 IN NORTHERN ILLINOIS. ALTHOUGH TOTAL
AMOUNTS WILL BE LIGHT...THE POSSIBILITY OF A QUICK HALF TO ONE INCH OF
SNOW RIGHT AROUND DAYBREAK MONDAY COULD CAUSE PROBLEMS FOR THE
MONDAY MORNING COMMUTE. AREAS SOUTH OF INTERSTATE 80 COULD SEE MORE
OF MIX BAG OF RAIN...FREEZING RAIN...SLEET AND SNOW GIVEN SLIGHTLY
WARMER MID LEVEL TEMPERATURES. SURFACE TEMPERATURES HERE MAY BE
HOVERING RIGHT AROUND FREEZING...SO QUESTIONS STILL RESIDE AROUND
HOW MUCH OF THIS PRECIP WILL BE FROZEN.
ONCE THIS BAND OF HEAVER PRECIP SHIFTS EAST OF THE AREA BY LATE
MORNING...IT APPEARS THAT THE MID LEVELS WILL DRY OUT
SUBSTANTIALLY...THUS ANY LINGERING PRECIP MONDAY AFTERNOON WOULD
LIKELY BE MORE DRIZZLY. THE COLDER SIDE OF THE STORM SYSTEM WILL
ARRIVE ACROSS THE REGION BY EARLY MONDAY EVENING...AS WINDS BECOME A
BIT GUSTY OUT OF THE WEST NORTHWEST. THIS SHOULD RESULT IN A COLDER
DAY ACROSS THE AREA ON TUESDAY. MOST AREAS WILL REMAIN DRY TUESDAY
AND TUESDAY NIGHT. HOWEVER...SOME LAKE EFFECT SNOW SHOWERS OR
FLURRIES ARE POSSIBLE ACROSS NORTHWESTERN INDIANA DURING THE DAY
TUESDAY. THEN AS THE LOWER LEVEL FLOW VEERS MORE NORTHERLY LATE
TUESDAY THESE LAKE EFFECT FLURRIES COULD GET INTO NORTHEASTERN
ILLINOIS TUESDAY EVENING. OVERALL...THIS DOES NOT APPEAR TO BE MUCH
OF A LAKE EFFECT EVENT AS LAKE INDUCED INVERSION HEIGHTS DO NOT
APPEAR VERY IMPRESSIVE...AND EVEN APPEAR TO REMAIN BELOW THE DENDRITIC
GROWTH ZONE.
THE WEATHER THE REST OF THE WEEK APPEARS TO BE FAIRLY QUIT...BUT ON
A WARMING TREND. MID LEVEL HEIGHT RISES ARE EXPECTED TO OVERSPREAD
MUCH OF THE CENTRAL CONUS LATER IN THE PERIOD IN RESPONSE TO THE
PERSISTENT NEGATIVE HEIGHT ANOMALIES ACROSS THE NORTHEASTERN PACIFIC
AND GULF OF ALASKA REGION SHIFTING EASTWARD TOWARDS THE WESTERN
NORTH AMERICAN COAST. THIS PARTICULARLY PATTERN STILL LOOKS TO BE
CONDUCE FOR A PERIOD OF MUCH ABOVE NORMAL TEMPERATURES NEXT FRIDAY
AND ESPECIALLY INTO SATURDAY. MODEL GUIDANCE HAS BEEN IN GOOD
AGREEMENT IN INDICATING THIS LARGER SCALE EL NINO-LIKE PATTERN
EVOLVING...AND GIVEN THAT THIS IS PATTERN KNOWN FOR PRODUCING MILD
CONDITIONS LOCALLY...CONFIDENCE IS ABOVE AVERAGE FOR THIS PERIOD TO
EXPERIENCE ABOVE AVERAGE TEMPERATURES. AT THIS TIME I HAVE REMAINED
A BIT CONSERVATIVE ON TEMPERATURES...ONLY WARMING THEM TO NEAR 50 FOR
SATURDAY. THIS COULD BE SEVERAL DEGREES TOO LOW IF THE CURRENT MODEL
FORECASTS PAN OUT. MOST GUIDANCE IS INDICATING 925 MB TEMPERATURES
ANYWHERE FROM +6 TO +10 DEGREES CELSIUS...WHICH COULD SUPPORT
TEMPERATURES INTO THE 50S BY NEXT SATURDAY UNDER A 570+ DM MID LEVEL
RIDGE.
KJB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* THIN SCT/BKN MVFR DECK 2500-2700 FT ERODING SHORTLY...WITH
MDW/GYY LIKELY TO OBSERVE A CIG THROUGH ABOUT 00Z.
* NORTH-NORTHEAST WINDS 10-15 KT GUSTING AROUND 20 KT WILL
DIMINISH QUICKLY THROUGH EARLY EVENING. WINDS BECOME SOUTHEAST
AT OR ABOVE 10 KT SUNDAY FROM MIDDAY ON.
RATZER
//DISCUSSION...UPDATED 18Z...
MVFR CLOUDS BEGINNING TO GO BROKEN OR SCATTER OUT IN PLACES THIS
AFTERNOON. EXPECT THAT CLOUDS WILL CONTINUE TO SPREAD ONSHORE FROM
THE LAKE THROUGH THE AFTERNOON AND EARLY EVENING HOURS. WITH THE
CLOUDS BREAKING UP SOME...WINDS WILL CONTINUE TO BE GUSTY OUT OF
THE NE. HIGH PRESSURE SLIDES BY TONIGHT WHICH WILL ALLOW SKIES TO
CLEAR QUITE A BIT MORE THIS EVENING AND WINDS WILL DIE DOWN AND
BECOME EASTERLY. WITH THE HIGH EAST OF THE AREA SUNDAY...EXPECT WINDS
TO SHIFT TO THE SOUTHEAST AND APPROACH OR EXCEED 10 KT SUNDAY
AFTERNOON. HIGH CLOUDS WILL BE SPREADING IN THROUGH THE DAY.
KMD
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* HIGH CONFIDENCE IN TRENDS OF ALL ELEMENTS.
RATZER
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...MAINLY VFR. SLGT CHANCE OF LIGHT SNOW/SLEET AND
MVFR SUNDAY. E WINDS BECOMING SE.
MONDAY...CHANCE RAIN/SLEET/SNOW. MVFR/BRIEF IFR POSSIBLE. S WINDS
BECOMING W.
TUESDAY...VFR. NW WINDS BECOMING N.
WEDNESDAY...VFR. NE WINDS BECOMING ESE.
THURSDAY...SLGT CHANCE LIGHT SNOW. VFR. S WINDS.
FRIDAY...VFR. SSE WINDS.
MDB
&&
.MARINE...
222 PM CST
TONIGHT THROUGH SUNDAY
THE STIFF NORTHERLY WINDS ACROSS THE LAKE TODAY WILL EASE THIS
EVENING AND VEER EASTWARD BY OVERNIGHT. WAVES WILL SUBSIDE BELOW 5
FT BY LATE TONIGHT. THE PROGRESSIVE PATTERN CONTINUES WITH HIGH
PRESSURE ADVANCING OVER THE LAKE QUICKLY OVERNIGHT FOLLOWED BY
INFLUENCE OF APPROACHING LOW PRESSURE ALREADY BY SUNDAY WITH WINDS
TURNING SOUTHEASTERLY.
SUNDAY NIGHT ONWARD
STRONG HIGH PRESSURE SHIFTING EASTWARD FROM QUEBEC AND WEAK LOW
PRESSURE TRACKING EAST ALONG THE CANADIAN BORDER WILL REALLY TIGHTEN
THE PRESSURE GRADIENT AND CAUSE SOUTHEAST WINDS TO TURN SOUTH AND
STRENGTHEN ON SUNDAY NIGHT INTO MONDAY MORNING. LOOKING AT GUSTS
PRIMARILY UP TO 25 TO 30 KT OVER THE OPEN WATERS...BUT COULD SEE A
FEW GALE FORCE GUSTS ON NORTH HALF. COLD FRONT TRAILING FROM THE
WEAK LOW PRESSURE WILL CROSS THE LAKE MONDAY EVENING AND
NIGHT...FOLLOWED BY ANOTHER EXPANSIVE HIGH PRESSURE. WINDS WILL TURN
WEST-NORTHWEST MONDAY NIGHT TO NORTHERLY BY TUESDAY MORNING.
CURRENTLY EXPECTING SPEEDS/GUSTS UP TO 30 KT LATE MONDAY NIGHT
THROUGH TUESDAY...BUT AGAIN CANNOT RULE OUT A PERIOD OF GALES ON THE
NORTH TUESDAY MORNING WHEN PRESSURE RISES MAXIMIZE. NORTHERLY WINDS
WILL GRADUALLY DIMINISH ON TUESDAY NIGHT INTO WEDNESDAY AS THE HIGH
TRAVERSES THE LAKE...SHIFTING TO SOUTHWEST ON THURSDAY INTO THURSDAY
NIGHT ON THE BACK SIDE OF THE HIGH.
FOR THE NEARSHORE WATERS...SMALL CRAFT ADVISORY CRITERIA IS POSSIBLE
SUNDAY NIGHT INTO MONDAY MORNING...ESPECIALLY FOR THE ILLINOIS
SHORE. SMALL CRAFT CONDITIONS ARE THEN LIKELY TUESDAY MORNING INTO
WEDNESDAY.
MTF/RC
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 3 AM SUNDAY.
&&
$$
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
321 PM CST Sat Dec 6 2014
.SHORT TERM...(Tonight)
ISSUED AT 308 PM CST SAT DEC 6 2014
Clearing trend has finally started to make some headway southward
this afternoon, with the edge of the stratocumulus deck generally
along a Macomb to Peoria to Pontiac line at 230 pm. AWIPS timing
tool would suggest a position along I-72 in the 530-6 pm time frame,
while the HRRR is a bit slower around 8 pm. Additional erosion from
the northeast is indicated by the HRRR late evening, although at the
same time cirrus clouds will be streaming east from the Plains.
Thus, have mainly gone with a partly cloudy sky for tonight`s
forecast.
North/northeast flow to prevail into tonight, as high pressure
currently over Lake Superior settles southeast across the Great
Lakes. Temperatures expected to drop into the mid to upper 20s
overnight.
&&
.LONG TERM...(Sunday through Saturday)
ISSUED AT 308 PM CST SAT DEC 6 2014
High pressure will shift eastward from Illinois Sunday as a clipper
system approaches from the WNW. This system will start bringing
increasingly thick high clouds through the day Sunday, but the air
mass will generally remain quite dry in a layer from around 2000 to
12000 feet. This dry layer will take some time to saturate
overnight, which means only a slight chance for precipitation NW of
the Illinois River before midnight. These layers will saturate
through the night allowing a better chance for precipitation
reaching the surface mainly during the morning. Dry air will start
to move in aloft during the day Monday as the system shifts east of
the area, ending deep enough saturation for precipitation processes
to take place. Precipitation type looks to be largely rain for
central Illinois given a deep warm layer just off the surface. Still
some chance for light freezing rain with temperatures hovering very
near the freezing mark at the surface. Farther to the north, the
warm layer off the surface is less pronounced, which could allow for
snow or a mix of rain and snow to reach the surface..
A high pressure ridge will develop over the plains for much of the
week with NW flow and dry conditions for central IL. Temperatures
will remain below normal for much of the week as a result. Friday
and Saturday may see a substantial warmup as the plains ridge shifts
over IL. Only chance for precipitation in the extended forecast at
this time appears to be around Friday morning as a few models hint
at a weak disturbance meandering through the region at this time.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
ISSUED AT 321 PM CST SAT DEC 6 2014
Clearing trend has made more substantial progress than earlier
thought, reaching KPIA at 21Z. Have updated the TAFs to scatter
out the clouds before 03Z. Some increase in mid and high cloudiness
is expected from the west after 06Z. Have kept conditions VFR
overnight, but will need to watch for some potential lower
visibilities in the areas that never had a chance to really clear
out before sunset.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Geelhart
LONG TERM...Onton
AVIATION...Geelhart
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
316 PM CST SAT DEC 6 2014
.SHORT TERM...
257 PM CST
NORTHEAST FLOW OVER THE REGION AHEAD OF HIGH PRESSURE HAS
CONTINUED TO EASE IN DRIER AIR. MID-AFTERNOON VISIBLE SATELLITE
IMAGERY REVEALS ONLY SOME DEPARTING STRATUS ACROSS THE FAR
SOUTHERN FORECAST AREA...AND SOME REMAINING RIBBONS OF LAKE EFFECT
CLOUDS INTO FAR NORTHEAST IL AND NORTHWEST IN. WATER VAPOR IMAGERY
CONFIRMS DRIER MID-LEVEL AIR AND SUPPRESSION MOVING OVERHEAD WHICH
SHOULD MITIGATE CLOUDS THIS EVENING...OUTSIDE OF A FEW LAKE
EFFECT CLOUDS INCHING WESTWARD OVER NORTHERN IL WITHIN THE
VEERING FLOW. A LIGHT WIND COMPONENT WILL REMAIN THIS EVENING
ALTHOUGH AS THE 1039 MB HIGH PASSES ACROSS WI...THE WINDS WILL
LIKELY BECOME LIGHT AND VARIABLE ALLOWING FOR FURTHER TEMPERATURE
DROP. DEW POINTS ARE SEVERAL DEGREES ABOVE THIS AT PRESENT...BUT
NOT REALLY A PATTERN WHERE WOULD EXPECT FOG...ESPECIALLY ANYTHING
OF NOTE.
SOUTHEAST WINDS WILL SETTLE IN ON SUNDAY WITH THE DEPARTING HIGH
AND LOW PRESSURE MARCHING EASTWARD NEAR THE NORTHERN CONUS BORDER.
HIGH CLOUDS LOOK TO GRADUALLY INCREASE/THICKEN DURING THE
AFTERNOON. GIVEN HIGHS TODAY REACHED THE UPPER 30S TO LOWER 40S
WOULD ENVISION SUNDAY BEING IN THE SAME ARENA IF CLOUDS DO NOT
THICKEN EARLIER THAN FORECAST.
MTF
&&
.LONG TERM...
315 PM CST
LONG TERM...SUNDAY NIGHT THROUGH SATURDAY...
OVERALL THE EXTENDED PERIOD WILL CONTINUE TO FEATURE A FAIRLY
PROGRESSIVE WEATHER PATTERN...WITH ONLY A QUICK HIT OF SOME COLDER
AIR FOR LATE TUESDAY INTO WEDNESDAY. THE MAIN FORECAST CONCERNS
DURING THE PERIOD WILL BE THE INCREASING POTENTIAL OF A QUICK HIT OF
WINTERY WEATHER LATE SUNDAY NIGHT INTO MONDAY MORNING.
WATER VAPOR IMAGERY INDICATES THE NEXT PACIFIC SYSTEM OF
INTEREST...NOW SHIFTING ONSHORE ACROSS WASHINGTON STATE. THIS
FEATURE...ALONG WITH AN ASSOCIATED AREA OF LOW PRESSURE IS EXPECTED
TO TRACK QUICKLY ALONG OR NEAR THE CANADIAN INTERNATIONAL
BORDER SUNDAY THROUGH TUESDAY. TYPICALLY THIS TYPE OF TRACK IS NOT
GOOD FOR MUCH PRECIPITATION FOR THE AREA...AND OVERALL THIS WILL BE
THE CASE. HOWEVER...IT APPEARS THAT QUICK HIT OF WINTRY PRECIPITATION
IS LIKELY LATE SUNDAY NIGHT INTO EARLY MONDAY MORNING.
A PERIOD OF INCREASING ISENTROPIC ASCENT COMBINED WITH SOME DECENT
Q-VECTOR CONVERGENCE...ASSOCIATED WITH ADDITIONAL SHORTWAVE ENERGY
DIGGING SOUTHEASTWARD TOWARDS THAT AREA LATER SUNDAY NIGHT...SHOULD
PROVIDE A SHORT PERIOD OF FORCING SUPPORTIVE OF PRECIPITATION ACROSS
NORTHERN ILLINOIS/NORTHWESTERN INDIANA. OVERALL...THIS STILL APPEARS
TO BE A SMALL EVENT FOR THE AREA. HOWEVER...IT APPEARS THAT A
STRENGTHENING BAROCLINIC ZONE ALONG AN OCCLUDED FRONTAL BOUNDARY MAY
PROVIDE A SHORT PERIOD OF ENHANCED MESOSCALE FORCING...SUPPORTIVE A
SHORT PERIOD OF HEAVIER PRECIPITATION...ESPECIALLY GIVEN THE PRESENCE
OF STEEP MID LEVEL LAPSE RATES INTO MONDAY MORNING. THUS...IT
APPEARS THAT BAND OF PRECIPITATION...POSSIBLY ONLY LASTING A COUPLE
HOURS AT ANY GIVEN LOCATION...IS LIKELY TO MOVE ACROSS THE AREA IN
TIME FOR THE MONDAY MORNING RUSH.
PRECIP TYPE STILL APPEARS TO BE TRICKY WITH THIS ACTIVITY EARLY
MONDAY. ASIDE FOR THE NAM SOLUTION...MOST MODEL DERIVED SOUNDINGS
ACROSS NORTHERN ILLINOIS INDICATE MAX LAYER TEMPERATURES OF ONLY +1
TO +1.5 DEGREES CELSIUS...WHICH WOULD SUGGEST ONLY PARTIAL MELTING OF
DENDRITES...POSSIBLY RESULTING IN SNOW AND SLEET PRECIP TYPES ACROSS
MOST OF FAR NORTHERN ILLINOIS. ALSO...GIVEN THAT THERE COULD BE SOME
ENHANCE PRECIP RATES WITH THIS ACTIVITY...AS WELL AS THE FACT THAT
EVAPORATIVE COOLING POTENTIAL SUNDAY NIGHT WILL BE HIGH...IT APPEARS
PRUDENT TO MENTION MORE OF A SNOW AND SLEET SCENARIO ACROSS FAR
NORTHERN ILLINOIS RATHER THAN FREEZING RAIN AT THIS POINT. THEREFORE...I
HAVE TRENDED THE FORECAST IN THIS DIRECTION.
ACCUMULATIONS ARE ALSO POSSIBLE WITH THIS ACTIVITY. IN FACT...SOME
AREAS COULD GET A QUICK INCH OF SNOW...IF IT FALLS PRIMARILY AS SUCH.
AT THIS TIME IT APPEARS THE BEST POTENTIAL FOR THIS APPEARS TO BE
ROUGHLY ALONG AND NORTH OF I-88 IN NORTHERN ILLINOIS. ALTHOUGH TOTAL
AMOUNTS WILL BE LIGHT...THE POSSIBILITY OF A QUICK HALF TO ONE INCH OF
SNOW RIGHT AROUND DAYBREAK MONDAY COULD CAUSE PROBLEMS FOR THE
MONDAY MORNING COMMUTE. AREAS SOUTH OF INTERSTATE 80 COULD SEE MORE
OF MIX BAG OF RAIN...FREEZING RAIN...SLEET AND SNOW GIVEN SLIGHTLY
WARMER MID LEVEL TEMPERATURES. SURFACE TEMPERATURES HERE MAY BE
HOVERING RIGHT AROUND FREEZING...SO QUESTIONS STILL RESIDE AROUND
HOW MUCH OF THIS PRECIP WILL BE FROZEN.
ONCE THIS BAND OF HEAVER PRECIP SHIFTS EAST OF THE AREA BY LATE
MORNING...IT APPEARS THAT THE MID LEVELS WILL DRY OUT
SUBSTANTIALLY...THUS ANY LINGERING PRECIP MONDAY AFTERNOON WOULD
LIKELY BE MORE DRIZZLY. THE COLDER SIDE OF THE STORM SYSTEM WILL
ARRIVE ACROSS THE REGION BY EARLY MONDAY EVENING...AS WINDS BECOME A
BIT GUSTY OUT OF THE WEST NORTHWEST. THIS SHOULD RESULT IN A COLDER
DAY ACROSS THE AREA ON TUESDAY. MOST AREAS WILL REMAIN DRY TUESDAY
AND TUESDAY NIGHT. HOWEVER...SOME LAKE EFFECT SNOW SHOWERS OR
FLURRIES ARE POSSIBLE ACROSS NORTHWESTERN INDIANA DURING THE DAY
TUESDAY. THEN AS THE LOWER LEVEL FLOW VEERS MORE NORTHERLY LATE
TUESDAY THESE LAKE EFFECT FLURRIES COULD GET INTO NORTHEASTERN
ILLINOIS TUESDAY EVENING. OVERALL...THIS DOES NOT APPEAR TO BE MUCH
OF A LAKE EFFECT EVENT AS LAKE INDUCED INVERSION HEIGHTS DO NOT
APPEAR VERY IMPRESSIVE...AND EVEN APPEAR TO REMAIN BELOW THE DENDRITIC
GROWTH ZONE.
THE WEATHER THE REST OF THE WEEK APPEARS TO BE FAIRLY QUIT...BUT ON
A WARMING TREND. MID LEVEL HEIGHT RISES ARE EXPECTED TO OVERSPREAD
MUCH OF THE CENTRAL CONUS LATER IN THE PERIOD IN RESPONSE TO THE
PERSISTENT NEGATIVE HEIGHT ANOMALIES ACROSS THE NORTHEASTERN PACIFIC
AND GULF OF ALASKA REGION SHIFTING EASTWARD TOWARDS THE WESTERN
NORTH AMERICAN COAST. THIS PARTICULARLY PATTERN STILL LOOKS TO BE
CONDUCE FOR A PERIOD OF MUCH ABOVE NORMAL TEMPERATURES NEXT FRIDAY
AND ESPECIALLY INTO SATURDAY. MODEL GUIDANCE HAS BEEN IN GOOD
AGREEMENT IN INDICATING THIS LARGER SCALE EL NINO-LIKE PATTERN
EVOLVING...AND GIVEN THAT THIS IS PATTERN KNOWN FOR PRODUCING MILD
CONDITIONS LOCALLY...CONFIDENCE IS ABOVE AVERAGE FOR THIS PERIOD TO
EXPERIENCE ABOVE AVERAGE TEMPERATURES. AT THIS TIME I HAVE REMAINED
A BIT CONSERVATIVE ON TEMPERATURES...ONLY WARMING THEM TO NEAR 50 FOR
SATURDAY. THIS COULD BE SEVERAL DEGREES TOO LOW IF THE CURRENT MODEL
FORECASTS PAN OUT. MOST GUIDANCE IS INDICATING 925 MB TEMPERATURES
ANYWHERE FROM +6 TO +10 DEGREES CELSIUS...WHICH COULD SUPPORT
TEMPERATURES INTO THE 50S BY NEXT SATURDAY UNDER A 570+ DM MID LEVEL
RIDGE.
KJB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* MVFR CIGS SCATTERING SOME TIME LATE THIS AFTERNOON.
* N-NNE WINDS 12-15 KT GUSTING TO 20-22 KT AT TIMES THROUGH THE
AFTERNOON. SE WINDS AT OR ABOVE 10 KT SUNDAY FROM MIDDAY ON.
KMD
//DISCUSSION...UPDATED 18Z...
MVFR CLOUDS BEGINNING TO GO BROKEN OR SCATTER OUT IN PLACES THIS
AFTERNOON. EXPECT THAT CLOUDS WILL CONTINUE TO SPREAD ONSHORE FROM
THE LAKE THROUGH THE AFTERNOON AND EARLY EVENING HOURS. WITH THE
CLOUDS BREAKING UP SOME...WINDS WILL CONTINUE TO BE GUSTY OUT OF
THE NE. HIGH PRESSURE SLIDES BY TONIGHT WHICH WILL ALLOW SKIES TO
CLEAR QUITE A BIT MORE THIS EVENING AND WINDS WILL DIE DOWN AND
BECOME EASTERLY. WITH THE HIGH EAST OF THE AREA SUNDAY...EXPECT WINDS
TO SHIFT TO THE SOUTHEAST AND APPROACH OR EXCEED 10 KT SUNDAY
AFTERNOON. HIGH CLOUDS WILL BE SPREADING IN THROUGH THE DAY.
KMD
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* LOW CONFIDENCE IN TIMING OF SCATTERING THE MVFR CLOUD DECK LATER
TODAY.
* HIGH CONFIDENCE IN WIND TRENDS.
KMD
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...MAINLY VFR. SLGT CHANCE OF LIGHT SNOW/SLEET AND
MVFR SUNDAY. E WINDS BECOMING SE.
MONDAY...CHANCE RAIN/SLEET/SNOW. MVFR/BRIEF IFR POSSIBLE. S WINDS
BECOMING W.
TUESDAY...VFR. NW WINDS BECOMING N.
WEDNESDAY...VFR. NE WINDS BECOMING ESE.
THURSDAY...SLGT CHANCE LIGHT SNOW. VFR. S WINDS.
FRIDAY...VFR. SSE WINDS.
MDB
&&
.MARINE...
222 PM CST
TONIGHT THROUGH SUNDAY
THE STIFF NORTHERLY WINDS ACROSS THE LAKE TODAY WILL EASE THIS
EVENING AND VEER EASTWARD BY OVERNIGHT. WAVES WILL SUBSIDE BELOW 5
FT BY LATE TONIGHT. THE PROGRESSIVE PATTERN CONTINUES WITH HIGH
PRESSURE ADVANCING OVER THE LAKE QUICKLY OVERNIGHT FOLLOWED BY
INFLUENCE OF APPROACHING LOW PRESSURE ALREADY BY SUNDAY WITH WINDS
TURNING SOUTHEASTERLY.
SUNDAY NIGHT ONWARD
STRONG HIGH PRESSURE SHIFTING EASTWARD FROM QUEBEC AND WEAK LOW
PRESSURE TRACKING EAST ALONG THE CANADIAN BORDER WILL REALLY TIGHTEN
THE PRESSURE GRADIENT AND CAUSE SOUTHEAST WINDS TO TURN SOUTH AND
STRENGTHEN ON SUNDAY NIGHT INTO MONDAY MORNING. LOOKING AT GUSTS
PRIMARILY UP TO 25 TO 30 KT OVER THE OPEN WATERS...BUT COULD SEE A
FEW GALE FORCE GUSTS ON NORTH HALF. COLD FRONT TRAILING FROM THE
WEAK LOW PRESSURE WILL CROSS THE LAKE MONDAY EVENING AND
NIGHT...FOLLOWED BY ANOTHER EXPANSIVE HIGH PRESSURE. WINDS WILL TURN
WEST-NORTHWEST MONDAY NIGHT TO NORTHERLY BY TUESDAY MORNING.
CURRENTLY EXPECTING SPEEDS/GUSTS UP TO 30 KT LATE MONDAY NIGHT
THROUGH TUESDAY...BUT AGAIN CANNOT RULE OUT A PERIOD OF GALES ON THE
NORTH TUESDAY MORNING WHEN PRESSURE RISES MAXIMIZE. NORTHERLY WINDS
WILL GRADUALLY DIMINISH ON TUESDAY NIGHT INTO WEDNESDAY AS THE HIGH
TRAVERSES THE LAKE...SHIFTING TO SOUTHWEST ON THURSDAY INTO THURSDAY
NIGHT ON THE BACK SIDE OF THE HIGH.
FOR THE NEARSHORE WATERS...SMALL CRAFT ADVISORY CRITERIA IS POSSIBLE
SUNDAY NIGHT INTO MONDAY MORNING...ESPECIALLY FOR THE ILLINOIS
SHORE. SMALL CRAFT CONDITIONS ARE THEN LIKELY TUESDAY MORNING INTO
WEDNESDAY.
MTF/RC
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 3 AM SUNDAY.
&&
$$
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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
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WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
308 PM CST Sat Dec 6 2014
.SHORT TERM...(Tonight)
ISSUED AT 308 PM CST SAT DEC 6 2014
Clearing trend has finally started to make some headway southward
this afternoon, with the edge of the stratocumulus deck generally
along a Macomb to Peoria to Pontiac line at 230 pm. AWIPS timing
tool would suggest a position along I-72 in the 530-6 pm time frame,
while the HRRR is a bit slower around 8 pm. Additional erosion from
the northeast is indicated by the HRRR late evening, although at the
same time cirrus clouds will be streaming east from the Plains.
Thus, have mainly gone with a partly cloudy sky for tonight`s
forecast.
North/northeast flow to prevail into tonight, as high pressure
currently over Lake Superior settles southeast across the Great
Lakes. Temperatures expected to drop into the mid to upper 20s
overnight.
&&
.LONG TERM...(Sunday through Saturday)
ISSUED AT 308 PM CST SAT DEC 6 2014
High pressure will shift eastward from Illinois Sunday as a clipper
system approaches from the WNW. This system will start bringing
increasingly thick high clouds through the day Sunday, but the air
mass will generally remain quite dry in a layer from around 2000 to
12000 feet. This dry layer will take some time to saturate
overnight, which means only a slight chance for precipitation NW of
the Illinois River before midnight. These layers will saturate
through the night allowing a better chance for precipitation
reaching the surface mainly during the morning. Dry air will start
to move in aloft during the day Monday as the system shifts east of
the area, ending deep enough saturation for precipitation processes
to take place. Precipitation type looks to be largely rain for
central Illinois given a deep warm layer just off the surface. Still
some chance for light freezing rain with temperatures hovering very
near the freezing mark at the surface. Farther to the north, the
warm layer off the surface is less pronounced, which could allow for
snow or a mix of rain and snow to reach the surface..
A high pressure ridge will develop over the plains for much of the
week with NW flow and dry conditions for central IL. Temperatures
will remain below normal for much of the week as a result. Friday
and Saturday may see a substantial warmup as the plains ridge shifts
over IL. Only chance for precipitation in the extended forecast at
this time appears to be around Friday morning as a few models hint
at a weak disturbance meandering through the region at this time.
&&
.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
ISSUED AT 1133 AM CST SAT DEC 6 2014
Challenging forecast with the low cloud deck that currently covers
the TAF sites. An area of clearing is moving southwest from
northern Illinois, and is timed to reach KPIA around 2030Z.
However, guidance indicates the remainder of the TAF sites will
stay with the lower ceilings through the evening. Ceilings in
eastern Illinois and western Indiana currently around 1500 feet,
and think that there will be gradual improvement to at least that
level this afternoon. HRRR and RAP models suggest any wholesale
clearing probably would be after 06Z, as some drier air is
advected southwest from lower Michigan. Northerly winds will
gradually trend clockwise this evening as high pressure builds
into the Great Lakes, then become more east-southeast on Sunday as
the high moves away.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Geelhart
LONG TERM...Onton
AVIATION...Geelhart
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1238 PM CST SAT DEC 6 2014
.UPDATE...1057 AM CST
MINOR ADJUSTMENTS HAVE BEEN MADE TO CLOUD TRENDS AND TEMPERATURES
THIS AFTERNOON. BROAD WEAK COLD AIR ADVECTION CONTINUES ACROSS THE
FORECAST AREA AS LOW PRESSURE OVER THE CENTRAL APPALACHIANS PULLS
AWAY AND HIGH PRESSURE OVER NORTHERN MN BUILDS EASTWARD. SYNOPTIC
STRATUS CLOUDS CONTINUE BASICALLY SOUTH OF I-80 WHILE LAKE INDUCED
CLOUDS PERSIST ACROSS MOST OF THE CHICAGO METRO AREA. VISIBLE
SATELLITE IMAGERY IS INDICATING BREAKS ACROSS THE LAKE AS DRIER
AIR FILTERS IN AND GIVEN THE SOMEWHAT WEAK COLD ADVECTION. ACARS
DATA INDICATES THE INVERSION IS STILL STOUT BUT WEAKENING AND THE
SATURATION IS ONLY ABOUT 1000 FT THICK. WITH THE UPSTREAM SATELLITE
TRENDS AND THE SOMEWHAT SHALLOW DEPTH OF THE CLOUDS...THINK MANY
AREAS ARE GOING TO GET SOME THINNING OR SCATTERING CLOUD
COVER BY MID-AFTERNOON...WITH THE EXCEPTION BEING THE FAR
SOUTHERN FORECAST AREA. HAVE ADJUSTED TEMPERATURES AS WELL AS CAN
FOR THE FLUCTUATING CLOUD COVER...THOUGH HIGHS FALL OUT SIMILARLY
TO FORECAST.
MTF
&&
.SHORT TERM...
409 AM CST
THROUGH SATURDAY NIGHT...
FOR THE REMAINDER OF THE NIGHT AND INTO SATURDAY MORNING...THE MAIN
FORECAST CONCERNS WILL FOCUS ON SKY COVER AND THE IMPACT ON
TEMPERATURE TRENDS. LATEST SURFACE ANALYSIS AND SATELLITE IMAGERY
INDICATE AN EXTENSIVE STRATUS DECK ACROSS THE REGION TRAPPED BENEATH
A STRONG INVERSION BASED AT AROUND 900MB. LATEST MODEL SOUNDINGS
INDICATE THAT THE INVERSION WILL HOLD FAST THROUGH THE REMAINDER OF
THE NIGHT AND MUCH OF THE DAY SATURDAY. ALSO...AS THE CENTER OF
HIGH PRESSURE MOVES ACROSS THE UPPER GREAT LAKES AND LOW PRESSURE
CONTINUES TO MOVE THROUGH THE OHIO VALLEY...WINDS WILL REMAIN NELY
OFF OF LAKE MICHIGAN...KEEPING MUCH OF NERN IL AND NWRN IN UNDER
CLOUD COVER A BIT LONGER THAN PREVIOUSLY ANTICIPATED. AS THE CENTER
OF THE HIGH SHIFTS TO THE EAST LATE THIS AFTERNOON AND THIS
EVENING...SFC FLOW WILL VEER MORE ELY-SELY...ALLOWING THE STRATUS
DECK TO FINALLY SCATTER OUT. NWRN PORTIONS OF THE CWA...GENERALLY
WEST OF THE FOX VALLEY COULD SCATTER OUT A BIT QUICKER THAN NERN
IL/NWRN IN AND LOCATION UNDER A FETCH OFF OF LAKE MICHIGAN. THIS
MAKES THE TEMPERATURE FORECAST FOR SATURDAY A BIT TRICKY AND WILL
ULTIMATELY DEPEND ON HOW QUICKLY CLOUD COVER CAN BREAK UP.
HOWEVER...THE REGION WILL STILL BE UNDER A COLD ADVECTIVE PATTERN AS
THE CENTER OF THE HIGH BUILDS ACROSS NRN MN AND LAKE SUPERIOR
TODAY...SO THE DIURNAL TEMPERATURE TREND SHOULD BE A LITTLE SLOWER
THAN...BUT AS THE CENTER OF THE HIGH SHIFT EAST OF LAKE SUPERIOR
LATE THIS AFTERNOON...THERE IS THE POTENTIAL FOR A LITTLE WARM
ADVECTION...AND WITH CLEARING SKIES...TEMPERATURES COULD SPIKE A FEW
DEGREES LATE THIS AFTERNOON...BEFORE THE SUN ANGLE GETS TOO LOW.
FOR THE REMAINDER OF SATURDAY NIGHT...EXPECT QUIET CONDITIONS AS SFC
RIDGING EXTENDS SOUTHWEST ACROSS THE AREA AND THROUGH THE MIDDLE
MISSISSIPPI VALLEY...WITH WINDS GRADUALLY VEERING TO SELY BY SUNDAY
MORNING. WITH DECREASING CLOUD COVER...DECREASING LOW LEVEL
MOISTURE...THE LOWER LEVELS SHOULD BE ABLE TO DECOUPLE OVERNIGHT
WITH WINDS DROPPING OFF AND RADIATIVE COOLING ALLOWING FOR
TEMPERATURES TO DROP INTO THE LOWER 20S FOR MOST AREAS...WITH THE
EXCEPTION OF THE URBAN HEAT ISLAND OF THE CHICAGO METRO AREA WHICH
SHOULD REMAIN IN THE UPPER 20S TO AROUND 30F.
KREIN
&&
.LONG TERM...
409 AM CST
SUNDAY THROUGH NEXT FRIDAY...
SUNDAY IS SHAPING UP TO BE A RELATIVELY PLEASANT DAY WITH SELY WINDS
PERSISTING THROUGH THE DAY AS THE HIGH MOVES INTO SERN CANADA AND A
LOW PRESSURE SYSTEM MOVES OUT OF THE SRN CANADIAN ROCKIES AND ACROSS
THE NRN PLAINS. THE EVOLUTION OF THIS SYSTEM HAS BEEN RELATIVELY
CONSISTENT OVER RECENT MODEL RUNS...IN TRACKING ACROSS THE NORTHERN
PLAINS AND DRAGGING A WEAK COLD FRONT AS IT TRACKS EWD. WINDS AHEAD
OF THE SYSTEM WILL VEER TO MORE SOUTHERLY ALLOWING SOME WARMER AIR
TO FILTER INTO THE REGION...BRINGING HIGHS IN THE UPPER 30S ACROSS
THE AREA. THE WEATHER PICTURE BECOMES A LITTLE MORE COMPLICATED AS
THE NEXT SYSTEM APPROACHES THE REGION. SINCE HIGH PRESSURE RIDGING
IS STILL EXPECTED TO EXTEND FROM NEW ENGLAND THROUGH THE LOWER
MISSISSIPPI VALLEY...THE GULF OF MEXICO WILL BE CUT OFF FROM THE
APPROACHING SYSTEM AND THE ONLY AVAILABLE MOISTURE FOR IT TO WORK
WITH WILL BE THE MEAGER AMOUNTS IN PLACE...PWATS AROUND A QUARTER OF
AN INCH AND WHAT MOISTURE IT CAN BRING AS A PACIFIC SOURCED MID
LEVEL SHORTWAVE. THROUGH THE EVENING ON SUNDAY...SFC TEMPERATURES
ARE EXPECTED TO DROP OFF INTO THE UPPER 20S TO THE LOWER 30S. MODEL
SOUNDING FOR SUNDAY NIGHT INTO MONDAY MORNING INDICATE WARMING ABOVE
THE BOUNDARY LAYER WITH TEMPS RISING TO 1-2C ABOVE A SUB-FREEZING
SFC LAYER. THE PCPN TYPE FORECAST FOR SUNDAY NIGHT INTO MONDAY
MORNING WILL BE COMPLICATED BY THE DEPTH AND DEGREE OF THE WARM
LAYER AND HOW FAR NORTH THE WARM LAYER CAN REACH. THE LATEST
GUIDANCE SUGGESTS THAT PCPN SHOULD START OUT AS A LITTLE LIGHT SNOW
OVER THE ROCKFORD AREA EARLY SUNDAY EVENING BEFORE THE WARM
INTRUSION REACHES INTO NCNTRL IL...WITH A TRANSITION OVER TO
FREEZING RAIN AND...PERHAPS...A LITTLE SLEET MIXING IN...WHICH WOULD
BE DEPENDENT ON THE DEPTH OF THE SURFACE-BASED FREEZING LAYER. AS
THE SYSTEM SLOWLY CROSSES THE AREA...MANY LOCATIONS COULD SEE A
PERIOD OF LIGHT FREEZING RAIN LATE SUNDAY NIGHT INTO EARLY MONDAY
MORNING...BEFORE CHANGING OVER TO ALL RAIN BY MIDDAY MONDAY. WITH
AVAILABLE DEEP LAYER MOISTURE STILL LIMITED...WITH PWATS ONLY OF A
HALF INCH OR SO...PCPN AMOUNTS SHOULD BE LIGHT...BUT EVEN A LIGHT
GLAZING OF FREEZING RAIN IN TIME FOR THE MONDAY MORNING RUSH HOURS
COULD CREATE TRAVEL DIFFICULTIES. HOWEVER...HIGH PRESSURE IS
EXPECTED TO QUICKLY BUILD ACROSS THE REGION FOLLOWING THE FRONTAL
PASSAGE...AND ANY PCPN SHOULD COME TO AN END BY LATE MONDAY
AFTERNOON OVER THE WRN PORTIONS OF THE CWA AND IN THE EARLY EVENING
FOR THE FAR SOUTHEAST. TEMPERATURES SHOULD BE HIGH ENOUGH DURG THE
LATE AFTERNOON HOURS THAT THE CHANCES FOR ANY FREEZING PCPN FOR THE
EVENING RUSH HOURS ARE LOW.
AS THE NEXT AREA OF HIGH PRESSURE BUILDS ACROSS THE REGION...A SHORT
PERIOD OF COOL...DRY CONDITIONS WILL PREVAIL THROUGH WEDNESDAY...WITH
HIGHS IN THE LOWER TO MIDDLE 30S AND OVERNIGHT LOWS IN THE UPPER
TEENS TO LOWER 20S. THE SYSTEM PASSING THROUGH THE AREA MONDAY
NIGHT IS EXPECTED TO DEVELOP INTO A DEEP UPPER LOW OVER THE MID
ATLANTIC REGION BY WEDNESDAY AND THEN SLOWLY MOVE UP THE EAST
COAST. BY WEDNESDAY NIGHT...THE DEEP UPPER LOW WILL MOVE OVER NEW
ENGLAND AS UPPER RIDING BUILDS FROM THE SRN ROCKIES THROUGH THE
UPPER MISSISSIPPI VALLEY. A WEAK SHORTWAVE IN THE NLY FLOW ALOFT
BETWEEN THESE TO LARGE SCALE SYSTEMS COULD BRING A BIT OF LIGHT SNOW
FOR WEDNESDAY NIGHT INTO THURSDAY...BUT ANY ASSOCIATED SNOWFALL
SHOULD BE LIGHT. TOWARDS THE END OF THE WEEK..THE UPPER RIDGING IS
EXPECTED TO BUILD ACROSS THE UPPER MIDWEST...BRINGING A WARMING
TREND FOR LATE NEXT WEEK...WITH TEMPS POSSIBLY REACHING THE LOWER TO
MIDDLE 40S BY NEXT FRIDAY.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* MVFR CIGS SCATTERING SOME TIME LATE THIS AFTERNOON.
* N-NNE WINDS 12-15 KT GUSTING TO 20-22 KT AT TIMES THROUGH THE
AFTERNOON. SE WINDS AT OR ABOVE 10 KT SUNDAY FROM MIDDAY ON.
KMD
//DISCUSSION...UPDATED 18Z...
MVFR CLOUDS BEGINNING TO GO BROKEN OR SCATTER OUT IN PLACES THIS
AFTERNOON. EXPECT THAT CLOUDS WILL CONTINUE TO SPREAD ONSHORE FROM
THE LAKE THROUGH THE AFTERNOON AND EARLY EVENING HOURS. WITH THE
CLOUDS BREAKING UP SOME...WINDS WILL CONTINUE TO BE GUSTY OUT OF
THE NE. HIGH PRESSURE SLIDES BY TONIGHT WHICH WILL ALLOW SKIES TO
CLEAR QUITE A BIT MORE THIS EVENING AND WINDS WILL DIE DOWN AND
BECOME EASTERLY. WITH THE HIGH EAST OF THE AREA SUNDAY...EXPECT WINDS
TO SHIFT TO THE SOUTHEAST AND APPROACH OR EXCEED 10 KT SUNDAY
AFTERNOON. HIGH CLOUDS WILL BE SPREADING IN THROUGH THE DAY.
KMD
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* LOW CONFIDENCE IN TIMING OF SCATTERING THE MVFR CLOUD DECK LATER
TODAY.
* HIGH CONFIDENCE IN WIND TRENDS.
KMD
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...MAINLY VFR. SLGT CHANCE OF LIGHT SNOW/SLEET AND
MVFR SUNDAY. E WINDS BECOMING SE.
MONDAY...CHANCE RAIN/SLEET/SNOW. MVFR/BRIEF IFR POSSIBLE. S WINDS
BECOMING W.
TUESDAY...VFR. NW WINDS BECOMING N.
WEDNESDAY...VFR. NE WINDS BECOMING ESE.
THURSDAY...SLGT CHANCE LIGHT SNOW. VFR. S WINDS.
FRIDAY...VFR. SSE WINDS.
MDB
&&
.MARINE...
256 AM CST
LOW PRESSURE CONTINUES TO MOVE NORTHEAST UP THE OHIO RIVER VALLEY
EARLY THIS MORNING WITH STRONG HIGH PRESSURE MOVING EASTWARD ACROSS
THE EASTERN DAKOTAS. WINDS ARE STARTING TO INCREASE AS THE PRESSURE
GRADIENT BETWEEN THESE TWO SYSTEMS TIGHTENS UP THROUGH THE MORNING.
AS A RESULT...EXPECT NORTH TO NORTHEAST WINDS TO RANGE FROM 20 TO 25
KT WITH GUSTS TO 30 KT ACROSS THE CENTRAL AND SOUTHERN PARTS OF THE
LAKE THIS MORNING/AFTERNOON WITH NORTHERN AREAS DIMINISHING THROUGH
THE AFTERNOON AS THE INFLUENCE OF THE HIGH ARRIVES. SPEEDS WILL
DIMINISH ACROSS THE LAKE THIS EVENING AND TONIGHT AS THE DIRECTION
TURNS EAST THEN SOUTHEAST AS THE HIGH SHIFTS TO THE EAST. WILL
CONTINUE WITH THE SMALL CRAFT ADVISORY INTO EARLY TONIGHT AS THE
LONG FETCH OF WIND WILL KEEP WAVES ELEVATED AFTER WINDS DIMINISH THIS
EVENING.
LOW PRESSURE WILL DEVELOP IN THE LEE OF THE NORTHERN ROCKIES SUNDAY
AND MOVE EASTWARD ALONG THE U.S./CANADIAN BORDER...CROSSING LAKE
SUPERIOR MONDAY EVENING. THE LOW WILL DRAG A COLD FRONT ACROSS THE
LAKE MONDAY EVENING. SOUTHERLY WINDS WILL INCREASE AHEAD OF THE LOW
SUNDAY AND SUNDAY NIGHT THEN SHIFT TO THE NORTHWEST BEHIND THE FRONT
MONDAY NIGHT. STRONG HIGH PRESSURE WILL BUILD IN BEHIND THE LOW INTO
TUESDAY WITH A FAIRLY STRONG PUSH OF COLDER AIR AND A TIGHT PRESSURE
GRADIENT SUPPORTING GUSTY NORTH TO NORTHWEST WINDS. WINDS WILL
DIMINISH WEDNESDAY AS THE HIGH MOVES OVERHEAD.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 3 AM SUNDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1133 AM CST Sat Dec 6 2014
.UPDATE...
ISSUED AT 939 AM CST SAT DEC 6 2014
Main concern for today is with cloud cover. Widespread stratus
covers the forecast area this morning, with ceilings east of I-57
managing to reach just above 1000 feet while they remain 500 feet
or less most areas west. This morning`s upper air sounding, plus
forecast soundings off the latest NAM and RAP models, show a
persistent inversion around 950 mb. There is some clearing that
has occurred over the northwest corner of Illinois, but visible
satellite loops showing only slow southern progress toward the
Quad Cities area. We`re in the time of year where low sun angle
makes it difficult to burn off the low clouds. Areas northwest of
Peoria most likely to see any sun this afternoon although there
will still be quite a few clouds around. The remainder of the CWA
should remain mainly cloudy.
Going forecast is in pretty good shape, and only required some
minor tweaks to incorporate current trends.
&&
.SHORT TERM...(Today)
ISSUED AT 323 AM CST SAT DEC 6 2014
The 08z/2am surface analysis has a 1015mb low in NC Kentucky moving
northeast along a stationary front. Rain showers on the NW flank of
the low are steadily progressing eastward out of our E-SE counties.
The back edge of precip should reach I-57 by 09z/3am and be
completely out of our IL counties by 13z/7am.
Despite dry air aloft flowing into Illinois on N-NW winds, a strong
subsidence inversion is indicated in all the short term models. That
will limit mixing of the dry air in to the low level moisture, and
work to keep clouds across our forecast area over the next 12 hours
if not well into tonight. The satellite images are showing a
clearing line progressing south toward IL across MN/WI, however,
that clearing should slow down with the intensification of the
inversion today. High temps will not climb appreciably under the
blanket of clouds, with readings topping out in the upper 30s toward
Galesburg and into the mid 40s toward Lawrenceville.
&&
.LONG TERM...(Tonight through Friday)
ISSUED AT 323 AM CST SAT DEC 6 2014
High pressure continues to build into the region, although the
inversion remains and will likely see a continuation of the clouds
until the incredibly dry air aloft finally works its way down into
the higher RH in the llvls. This same dry air is also the deciding
factor in the next issue for the forecast with an approaching wave
Sun night/Monday. Prev models had more disagreement and the NAM
with a more southerly track for the wave was the outlier. With this
run, both the GFS and ECMWF starting to look a lot more like the
prev NAM. A small system developing into a larger upper trof late
in the weekend...with the look of two smaller waves bringing pops
back into the region. Although the GFS and the ECMWF are more
consistent with the prev NAM, the NAM is far more scarce with the
QPF. Keeping the forecast chances low for shower activity after
midnight Sun night/Monday... not only for lack of continuity from
run to run, but the considerable amount of dry air will take a while
to overcome. Not convinced the best lift will coincide with the
eventual saturation of the column.
Beyond Monday and its cold front, temps cool briefly, then moderate
back into the 40s for highs through the end of the week. 00z ECMWF
completely pulls back on a small disturbance Wed night/Thursday, and
should this trend continue, will likely pull the pops altogether out
of the next couple runs. For now, slight pops in the forecast to
cover a brief disturbance diving into the Great Lakes region on the
retreating edge of the larger scale 500 mb trof exiting out to the
northeast. This difference btwn the GFS and the European also
delineates the break point in the extended between any agreement in
the midst of a small pattern shift. Depth of the thickness ridge
going into day 7 and 8 will definitely result in some blend issues
going into next weekend.
&&
.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
ISSUED AT 1133 AM CST SAT DEC 6 2014
Challenging forecast with the low cloud deck that currently covers
the TAF sites. An area of clearing is moving southwest from
northern Illinois, and is timed to reach KPIA around 2030Z.
However, guidance indicates the remainder of the TAF sites will
stay with the lower ceilings through the evening. Ceilings in
eastern Illinois and western Indiana currently around 1500 feet,
and think that there will be gradual improvement to at least that
level this afternoon. HRRR and RAP models suggest any wholesale
clearing probably would be after 06Z, as some drier air is
advected southwest from lower Michigan. Northerly winds will
gradually trend clockwise this evening as high pressure builds
into the Great Lakes, then become more east-southeast on Sunday as
the high moves away.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Geelhart
SHORT TERM...Shimon
LONG TERM...HJS
AVIATION...Geelhart
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1025 AM CST SAT DEC 6 2014
.SHORT TERM...
409 AM CST
THROUGH SATURDAY NIGHT...
FOR THE REMAINDER OF THE NIGHT AND INTO SATURDAY MORNING...THE MAIN
FORECAST CONCERNS WILL FOCUS ON SKY COVER AND THE IMPACT ON
TEMPERATURE TRENDS. LATEST SURFACE ANALYSIS AND SATELLITE IMAGERY
INDICATE AN EXTENSIVE STRATUS DECK ACROSS THE REGION TRAPPED BENEATH
A STRONG INVERSION BASED AT AROUND 900MB. LATEST MODEL SOUNDINGS
INDICATE THAT THE INVERSION WILL HOLD FAST THROUGH THE REMAINDER OF
THE NIGHT AND MUCH OF THE DAY SATURDAY. ALSO...AS THE CENTER OF
HIGH PRESSURE MOVES ACROSS THE UPPER GREAT LAKES AND LOW PRESSURE
CONTINUES TO MOVE THROUGH THE OHIO VALLEY...WINDS WILL REMAIN NELY
OFF OF LAKE MICHIGAN...KEEPING MUCH OF NERN IL AND NWRN IN UNDER
CLOUD COVER A BIT LONGER THAN PREVIOUSLY ANTICIPATED. AS THE CENTER
OF THE HIGH SHIFTS TO THE EAST LATE THIS AFTERNOON AND THIS
EVENING...SFC FLOW WILL VEER MORE ELY-SELY...ALLOWING THE STRATUS
DECK TO FINALLY SCATTER OUT. NWRN PORTIONS OF THE CWA...GENERALLY
WEST OF THE FOX VALLEY COULD SCATTER OUT A BIT QUICKER THAN NERN
IL/NWRN IN AND LOCATION UNDER A FETCH OFF OF LAKE MICHIGAN. THIS
MAKES THE TEMPERATURE FORECAST FOR SATURDAY A BIT TRICKY AND WILL
ULTIMATELY DEPEND ON HOW QUICKLY CLOUD COVER CAN BREAK UP.
HOWEVER...THE REGION WILL STILL BE UNDER A COLD ADVECTIVE PATTERN AS
THE CENTER OF THE HIGH BUILDS ACROSS NRN MN AND LAKE SUPERIOR
TODAY...SO THE DIURNAL TEMPERATURE TREND SHOULD BE A LITTLE SLOWER
THAN...BUT AS THE CENTER OF THE HIGH SHIFT EAST OF LAKE SUPERIOR
LATE THIS AFTERNOON...THERE IS THE POTENTIAL FOR A LITTLE WARM
ADVECTION...AND WITH CLEARING SKIES...TEMPERATURES COULD SPIKE A FEW
DEGREES LATE THIS AFTERNOON...BEFORE THE SUN ANGLE GETS TOO LOW.
FOR THE REMAINDER OF SATURDAY NIGHT...EXPECT QUIET CONDITIONS AS SFC
RIDGING EXTENDS SOUTHWEST ACROSS THE AREA AND THROUGH THE MIDDLE
MISSISSIPPI VALLEY...WITH WINDS GRADUALLY VEERING TO SELY BY SUNDAY
MORNING. WITH DECREASING CLOUD COVER...DECREASING LOW LEVEL
MOISTURE...THE LOWER LEVELS SHOULD BE ABLE TO DECOUPLE OVERNIGHT
WITH WINDS DROPPING OFF AND RADIATIVE COOLING ALLOWING FOR
TEMPERATURES TO DROP INTO THE LOWER 20S FOR MOST AREAS...WITH THE
EXCEPTION OF THE URBAN HEAT ISLAND OF THE CHICAGO METRO AREA WHICH
SHOULD REMAIN IN THE UPPER 20S TO AROUND 30F.
KREIN
&&
.LONG TERM...
409 AM CST
SUNDAY THROUGH NEXT FRIDAY...
SUNDAY IS SHAPING UP TO BE A RELATIVELY PLEASANT DAY WITH SELY WINDS
PERSISTING THROUGH THE DAY AS THE HIGH MOVES INTO SERN CANADA AND A
LOW PRESSURE SYSTEM MOVES OUT OF THE SRN CANADIAN ROCKIES AND ACROSS
THE NRN PLAINS. THE EVOLUTION OF THIS SYSTEM HAS BEEN RELATIVELY
CONSISTENT OVER RECENT MODEL RUNS...IN TRACKING ACROSS THE NORTHERN
PLAINS AND DRAGGING A WEAK COLD FRONT AS IT TRACKS EWD. WINDS AHEAD
OF THE SYSTEM WILL VEER TO MORE SOUTHERLY ALLOWING SOME WARMER AIR
TO FILTER INTO THE REGION...BRINGING HIGHS IN THE UPPER 30S ACROSS
THE AREA. THE WEATHER PICTURE BECOMES A LITTLE MORE COMPLICATED AS
THE NEXT SYSTEM APPROACHES THE REGION. SINCE HIGH PRESSURE RIDGING
IS STILL EXPECTED TO EXTEND FROM NEW ENGLAND THROUGH THE LOWER
MISSISSIPPI VALLEY...THE GULF OF MEXICO WILL BE CUT OFF FROM THE
APPROACHING SYSTEM AND THE ONLY AVAILABLE MOISTURE FOR IT TO WORK
WITH WILL BE THE MEAGER AMOUNTS IN PLACE...PWATS AROUND A QUARTER OF
AN INCH AND WHAT MOISTURE IT CAN BRING AS A PACIFIC SOURCED MID
LEVEL SHORTWAVE. THROUGH THE EVENING ON SUNDAY...SFC TEMPERATURES
ARE EXPECTED TO DROP OFF INTO THE UPPER 20S TO THE LOWER 30S. MODEL
SOUNDING FOR SUNDAY NIGHT INTO MONDAY MORNING INDICATE WARMING ABOVE
THE BOUNDARY LAYER WITH TEMPS RISING TO 1-2C ABOVE A SUB-FREEZING
SFC LAYER. THE PCPN TYPE FORECAST FOR SUNDAY NIGHT INTO MONDAY
MORNING WILL BE COMPLICATED BY THE DEPTH AND DEGREE OF THE WARM
LAYER AND HOW FAR NORTH THE WARM LAYER CAN REACH. THE LATEST
GUIDANCE SUGGESTS THAT PCPN SHOULD START OUT AS A LITTLE LIGHT SNOW
OVER THE ROCKFORD AREA EARLY SUNDAY EVENING BEFORE THE WARM
INTRUSION REACHES INTO NCNTRL IL...WITH A TRANSITION OVER TO
FREEZING RAIN AND...PERHAPS...A LITTLE SLEET MIXING IN...WHICH WOULD
BE DEPENDENT ON THE DEPTH OF THE SURFACE-BASED FREEZING LAYER. AS
THE SYSTEM SLOWLY CROSSES THE AREA...MANY LOCATIONS COULD SEE A
PERIOD OF LIGHT FREEZING RAIN LATE SUNDAY NIGHT INTO EARLY MONDAY
MORNING...BEFORE CHANGING OVER TO ALL RAIN BY MIDDAY MONDAY. WITH
AVAILABLE DEEP LAYER MOISTURE STILL LIMITED...WITH PWATS ONLY OF A
HALF INCH OR SO...PCPN AMOUNTS SHOULD BE LIGHT...BUT EVEN A LIGHT
GLAZING OF FREEZING RAIN IN TIME FOR THE MONDAY MORNING RUSH HOURS
COULD CREATE TRAVEL DIFFICULTIES. HOWEVER...HIGH PRESSURE IS
EXPECTED TO QUICKLY BUILD ACROSS THE REGION FOLLOWING THE FRONTAL
PASSAGE...AND ANY PCPN SHOULD COME TO AN END BY LATE MONDAY
AFTERNOON OVER THE WRN PORTIONS OF THE CWA AND IN THE EARLY EVENING
FOR THE FAR SOUTHEAST. TEMPERATURES SHOULD BE HIGH ENOUGH DURG THE
LATE AFTERNOON HOURS THAT THE CHANCES FOR ANY FREEZING PCPN FOR THE
EVENING RUSH HOURS ARE LOW.
AS THE NEXT AREA OF HIGH PRESSURE BUILDS ACROSS THE REGION...A SHORT
PERIOD OF COOL...DRY CONDITIONS WILL PREVAIL THROUGH WEDNESDAY...WITH
HIGHS IN THE LOWER TO MIDDLE 30S AND OVERNIGHT LOWS IN THE UPPER
TEENS TO LOWER 20S. THE SYSTEM PASSING THROUGH THE AREA MONDAY
NIGHT IS EXPECTED TO DEVELOP INTO A DEEP UPPER LOW OVER THE MID
ATLANTIC REGION BY WEDNESDAY AND THEN SLOWLY MOVE UP THE EAST
COAST. BY WEDNESDAY NIGHT...THE DEEP UPPER LOW WILL MOVE OVER NEW
ENGLAND AS UPPER RIDING BUILDS FROM THE SRN ROCKIES THROUGH THE
UPPER MISSISSIPPI VALLEY. A WEAK SHORTWAVE IN THE NLY FLOW ALOFT
BETWEEN THESE TO LARGE SCALE SYSTEMS COULD BRING A BIT OF LIGHT SNOW
FOR WEDNESDAY NIGHT INTO THURSDAY...BUT ANY ASSOCIATED SNOWFALL
SHOULD BE LIGHT. TOWARDS THE END OF THE WEEK..THE UPPER RIDGING IS
EXPECTED TO BUILD ACROSS THE UPPER MIDWEST...BRINGING A WARMING
TREND FOR LATE NEXT WEEK...WITH TEMPS POSSIBLY REACHING THE LOWER TO
MIDDLE 40S BY NEXT FRIDAY.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* CIGS AROUND 2000 FT SCATTERING SOME TIME LATE THIS AFTERNOON.
* N-NNE WINDS 12-15 KT GUSTING TO 20-22 KT AT TIMES THROUGH THE
AFTERNOON.
KMD
//DISCUSSION...UPDATED 12Z...
LOW PRESSURE CONTINUES TO MOVE NORTHEAST UP THE OHIO RIVER VALLEY
WHILE HIGH PRESSURE MOVES INTO THE UPPER MISSISSIPPI RIVER VALLEY.
STEADIER N TO NE WINDS HAVE SET UP IN THE 10-14 KT RANGE WITH
SPORADIC GUSTS ALSO APPEARING AT TIMES. GUSTS WILL LIKELY BECOME
MORE FREQUENT THIS AFTERNOON ESPECIALLY WHERE BREAKS CAN DEVELOP
IN THE CLOUD COVER. WINDS WILL GRADUALLY DIMINISH AND TURN
NORTHEAST THIS EVENING BEFORE SHIFTING SOUTHEAST TOWARD DAYBREAK
MONDAY.
CIGS WILL BE A CHALLENGE THROUGH THE MORNING. OBS SHOW BASE
HEIGHTS RANGING FROM 600-1100 FT ACROSS THE TERMINALS AND POINTS
UPSTREAM. A SLIGHT WIND COMPONENT OFF THE LAKE SEEMS TO BE KEEPING
BASES A LITTLE HIGHER WITHIN SEVERAL MILES INLAND OF THE SHORE
THANKS TO WARMER AIR OVER THE WATER. SATELLITE IMAGERY SHOWS A
WELL DEFINED BACK EDGE TO THE STRATUS ACROSS SOUTHERN WISCONSIN
WHICH IS MOVING SOUTHEAST. STRATUS IS ALSO EXTENSIVE ACROSS LAKE
MICHIGAN. THE BACK EDGE OF THIS STRATUS WILL LIKELY WORK ACROSS
MOST OF IF NOT ALL OF THE AREA THROUGH AROUND 16Z. HOWEVER...THERE
IS NOT SIGNIFICANT AMOUNTS OF DRY AIR WORKING INTO THE REGION SO
SCT-BKN STRATO CU MAY DEVELOP TOWARD MIDDAY....PROVIDED THE
CURRENT BAND DOES EXIT AND DOES NOT SLOW ITS SOUTHWARD PROGRESS.
IN OTHER WORDS THERE MAY BE A BREAK IN THE LOW CLOUDS BEFORE
DIURNAL CU DEVELOPS. ALSO...FLOW IN THE CLOUD LAYER WILL BE AIMED
FROM THE NORTHEAST RIGHT ACROSS THE LAKE SO LAKE PROCESSES MAY BE
SUFFICIENT TO KEEP STRATUS GOING AT LEAST WITHIN SEVERAL MILES OF
SHORE WELL INTO THE AFTERNOON. WILL GO AHEAD AND KEEP A LONGER
PERIOD OF STRATUS IN THE FORECAST FOR NOW WHICH COULD BE
PESSIMISTIC. OTHERWISE SKIES WILL CLEAR THIS EVENING IF THEY DO
NOT DO SO EARLIER. MORNING VSBY BETWEEN 2-5 SM WILL IMPROVE AS WE
GRADUALLY BEGIN TO WARM UP AFTER DAYBREAK.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* LOW CONFIDENCE IN TIMING OF SCATTERING THE MVFR CLOUD DECK LATER
TODAY.
* HIGH CONFIDENCE IN WIND TRENDS.
KMD
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...MAINLY VFR. SLGT CHANCE OF LIGHT SNOW/SLEET AND
MVFR SUNDAY. E WINDS BECOMING SE.
MONDAY...CHANCE RAIN/SLEET/SNOW. MVFR/BRIEF IFR POSSIBLE. S WINDS
BECOMING W.
TUESDAY...VFR. NW WINDS BECOMING N.
WEDNESDAY...VFR. NE WINDS BECOMING ESE.
THURSDAY...SLGT CHANCE LIGHT SNOW. VFR. S WINDS.
FRIDAY...VFR. SSE WINDS.
MDB
&&
.MARINE...
256 AM CST
LOW PRESSURE CONTINUES TO MOVE NORTHEAST UP THE OHIO RIVER VALLEY
EARLY THIS MORNING WITH STRONG HIGH PRESSURE MOVING EASTWARD ACROSS
THE EASTERN DAKOTAS. WINDS ARE STARTING TO INCREASE AS THE PRESSURE
GRADIENT BETWEEN THESE TWO SYSTEMS TIGHTENS UP THROUGH THE MORNING.
AS A RESULT...EXPECT NORTH TO NORTHEAST WINDS TO RANGE FROM 20 TO 25
KT WITH GUSTS TO 30 KT ACROSS THE CENTRAL AND SOUTHERN PARTS OF THE
LAKE THIS MORNING/AFTERNOON WITH NORTHERN AREAS DIMINISHING THROUGH
THE AFTERNOON AS THE INFLUENCE OF THE HIGH ARRIVES. SPEEDS WILL
DIMINISH ACROSS THE LAKE THIS EVENING AND TONIGHT AS THE DIRECTION
TURNS EAST THEN SOUTHEAST AS THE HIGH SHIFTS TO THE EAST. WILL
CONTINUE WITH THE SMALL CRAFT ADVISORY INTO EARLY TONIGHT AS THE
LONG FETCH OF WIND WILL KEEP WAVES ELEVATED AFTER WINDS DIMINISH THIS
EVENING.
LOW PRESSURE WILL DEVELOP IN THE LEE OF THE NORTHERN ROCKIES SUNDAY
AND MOVE EASTWARD ALONG THE U.S./CANADIAN BORDER...CROSSING LAKE
SUPERIOR MONDAY EVENING. THE LOW WILL DRAG A COLD FRONT ACROSS THE
LAKE MONDAY EVENING. SOUTHERLY WINDS WILL INCREASE AHEAD OF THE LOW
SUNDAY AND SUNDAY NIGHT THEN SHIFT TO THE NORTHWEST BEHIND THE FRONT
MONDAY NIGHT. STRONG HIGH PRESSURE WILL BUILD IN BEHIND THE LOW INTO
TUESDAY WITH A FAIRLY STRONG PUSH OF COLDER AIR AND A TIGHT PRESSURE
GRADIENT SUPPORTING GUSTY NORTH TO NORTHWEST WINDS. WINDS WILL
DIMINISH WEDNESDAY AS THE HIGH MOVES OVERHEAD.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 3 AM SUNDAY.
&&
$$
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
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
940 AM CST Sat Dec 6 2014
.UPDATE...
ISSUED AT 939 AM CST SAT DEC 6 2014
Main concern for today is with cloud cover. Widespread stratus
covers the forecast area this morning, with ceilings east of I-57
managing to reach just above 1000 feet while they remain 500 feet
or less most areas west. This morning`s upper air sounding, plus
forecast soundings off the latest NAM and RAP models, show a
persistent inversion around 950 mb. There is some clearing that
has occurred over the northwest corner of Illinois, but visible
satellite loops showing only slow southern progress toward the
Quad Cities area. We`re in the time of year where low sun angle
makes it difficult to burn off the low clouds. Areas northwest of
Peoria most likely to see any sun this afternoon although there
will still be quite a few clouds around. The remainder of the CWA
should remain mainly cloudy.
Going forecast is in pretty good shape, and only required some
minor tweaks to incorporate current trends.
&&
.SHORT TERM...(Today)
ISSUED AT 323 AM CST SAT DEC 6 2014
The 08z/2am surface analysis has a 1015mb low in NC Kentucky moving
northeast along a stationary front. Rain showers on the NW flank of
the low are steadily progressing eastward out of our E-SE counties.
The back edge of precip should reach I-57 by 09z/3am and be
completely out of our IL counties by 13z/7am.
Despite dry air aloft flowing into Illinois on N-NW winds, a strong
subsidence inversion is indicated in all the short term models. That
will limit mixing of the dry air in to the low level moisture, and
work to keep clouds across our forecast area over the next 12 hours
if not well into tonight. The satellite images are showing a
clearing line progressing south toward IL across MN/WI, however,
that clearing should slow down with the intensification of the
inversion today. High temps will not climb appreciably under the
blanket of clouds, with readings topping out in the upper 30s toward
Galesburg and into the mid 40s toward Lawrenceville.
&&
.LONG TERM...(Tonight through Friday)
ISSUED AT 323 AM CST SAT DEC 6 2014
High pressure continues to build into the region, although the
inversion remains and will likely see a continuation of the clouds
until the incredibly dry air aloft finally works its way down into
the higher RH in the llvls. This same dry air is also the deciding
factor in the next issue for the forecast with an approaching wave
Sun night/Monday. Prev models had more disagreement and the NAM
with a more southerly track for the wave was the outlier. With this
run, both the GFS and ECMWF starting to look a lot more like the
prev NAM. A small system developing into a larger upper trof late
in the weekend...with the look of two smaller waves bringing pops
back into the region. Although the GFS and the ECMWF are more
consistent with the prev NAM, the NAM is far more scarce with the
QPF. Keeping the forecast chances low for shower activity after
midnight Sun night/Monday... not only for lack of continuity from
run to run, but the considerable amount of dry air will take a while
to overcome. Not convinced the best lift will coincide with the
eventual saturation of the column.
Beyond Monday and its cold front, temps cool briefly, then moderate
back into the 40s for highs through the end of the week. 00z ECMWF
completely pulls back on a small disturbance Wed night/Thursday, and
should this trend continue, will likely pull the pops altogether out
of the next couple runs. For now, slight pops in the forecast to
cover a brief disturbance diving into the Great Lakes region on the
retreating edge of the larger scale 500 mb trof exiting out to the
northeast. This difference btwn the GFS and the European also
delineates the break point in the extended between any agreement in
the midst of a small pattern shift. Depth of the thickness ridge
going into day 7 and 8 will definitely result in some blend issues
going into next weekend.
&&
.AVIATION...(For the 12Z TAFS through 12Z Sunday morning)
ISSUED AT 600 AM CST SAT DEC 6 2014
The cloud forecast will continue to be challenging over the next
24 hours, as a clearing line approaches central IL from the north.
However, the HRRR and NAM keep low clouds entrenched until later this
evening, while the GFS dissipates the low clouds this morning.
The HRRR does show the brief small area of break in the low clouds
that drifted across the area the last 6 hours, but it also indicates
that break will fill in and the clearing line will barely graze our NW
counties this afternoon, but not reach all the way to PIA.
The NAM/SREF/RAP forecast soundings all show a strong subsidence
inversion trapping the low level moisture across our terminal
sites today. So confidence is moderate in keeping low clouds in
place through the day. Ceiling heights will start out LIFR at
BMI/DEC and IFR at PIA/CMI/SPI. All ceilings should at least climb
to MVFR after 18z with heating of the day and lifting of the LCL.
We went with some clearing eventually developing tonight with
advancing high pressure and a deeper layer of dry air.
Winds will remain north today at 10-14kt and shift to northeast
tonight as they diminish below 10kt.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Geelhart
SHORT TERM...Shimon
LONG TERM...HJS
AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
821 AM CST SAT DEC 6 2014
.SHORT TERM...
409 AM CST
THROUGH SATURDAY NIGHT...
FOR THE REMAINDER OF THE NIGHT AND INTO SATURDAY MORNING...THE MAIN
FORECAST CONCERNS WILL FOCUS ON SKY COVER AND THE IMPACT ON
TEMPERATURE TRENDS. LATEST SURFACE ANALYSIS AND SATELLITE IMAGERY
INDICATE AN EXTENSIVE STRATUS DECK ACROSS THE REGION TRAPPED BENEATH
A STRONG INVERSION BASED AT AROUND 900MB. LATEST MODEL SOUNDINGS
INDICATE THAT THE INVERSION WILL HOLD FAST THROUGH THE REMAINDER OF
THE NIGHT AND MUCH OF THE DAY SATURDAY. ALSO...AS THE CENTER OF
HIGH PRESSURE MOVES ACROSS THE UPPER GREAT LAKES AND LOW PRESSURE
CONTINUES TO MOVE THROUGH THE OHIO VALLEY...WINDS WILL REMAIN NELY
OFF OF LAKE MICHIGAN...KEEPING MUCH OF NERN IL AND NWRN IN UNDER
CLOUD COVER A BIT LONGER THAN PREVIOUSLY ANTICIPATED. AS THE CENTER
OF THE HIGH SHIFTS TO THE EAST LATE THIS AFTERNOON AND THIS
EVENING...SFC FLOW WILL VEER MORE ELY-SELY...ALLOWING THE STRATUS
DECK TO FINALLY SCATTER OUT. NWRN PORTIONS OF THE CWA...GENERALLY
WEST OF THE FOX VALLEY COULD SCATTER OUT A BIT QUICKER THAN NERN
IL/NWRN IN AND LOCATION UNDER A FETCH OFF OF LAKE MICHIGAN. THIS
MAKES THE TEMPERATURE FORECAST FOR SATURDAY A BIT TRICKY AND WILL
ULTIMATELY DEPEND ON HOW QUICKLY CLOUD COVER CAN BREAK UP.
HOWEVER...THE REGION WILL STILL BE UNDER A COLD ADVECTIVE PATTERN AS
THE CENTER OF THE HIGH BUILDS ACROSS NRN MN AND LAKE SUPERIOR
TODAY...SO THE DIURNAL TEMPERATURE TREND SHOULD BE A LITTLE SLOWER
THAN...BUT AS THE CENTER OF THE HIGH SHIFT EAST OF LAKE SUPERIOR
LATE THIS AFTERNOON...THERE IS THE POTENTIAL FOR A LITTLE WARM
ADVECTION...AND WITH CLEARING SKIES...TEMPERATURES COULD SPIKE A FEW
DEGREES LATE THIS AFTERNOON...BEFORE THE SUN ANGLE GETS TOO LOW.
FOR THE REMAINDER OF SATURDAY NIGHT...EXPECT QUIET CONDITIONS AS SFC
RIDGING EXTENDS SOUTHWEST ACROSS THE AREA AND THROUGH THE MIDDLE
MISSISSIPPI VALLEY...WITH WINDS GRADUALLY VEERING TO SELY BY SUNDAY
MORNING. WITH DECREASING CLOUD COVER...DECREASING LOW LEVEL
MOISTURE...THE LOWER LEVELS SHOULD BE ABLE TO DECOUPLE OVERNIGHT
WITH WINDS DROPPING OFF AND RADIATIVE COOLING ALLOWING FOR
TEMPERATURES TO DROP INTO THE LOWER 20S FOR MOST AREAS...WITH THE
EXCEPTION OF THE URBAN HEAT ISLAND OF THE CHICAGO METRO AREA WHICH
SHOULD REMAIN IN THE UPPER 20S TO AROUND 30F.
KREIN
&&
.LONG TERM...
409 AM CST
SUNDAY THROUGH NEXT FRIDAY...
SUNDAY IS SHAPING UP TO BE A RELATIVELY PLEASANT DAY WITH SELY WINDS
PERSISTING THROUGH THE DAY AS THE HIGH MOVES INTO SERN CANADA AND A
LOW PRESSURE SYSTEM MOVES OUT OF THE SRN CANADIAN ROCKIES AND ACROSS
THE NRN PLAINS. THE EVOLUTION OF THIS SYSTEM HAS BEEN RELATIVELY
CONSISTENT OVER RECENT MODEL RUNS...IN TRACKING ACROSS THE NORTHERN
PLAINS AND DRAGGING A WEAK COLD FRONT AS IT TRACKS EWD. WINDS AHEAD
OF THE SYSTEM WILL VEER TO MORE SOUTHERLY ALLOWING SOME WARMER AIR
TO FILTER INTO THE REGION...BRINGING HIGHS IN THE UPPER 30S ACROSS
THE AREA. THE WEATHER PICTURE BECOMES A LITTLE MORE COMPLICATED AS
THE NEXT SYSTEM APPROACHES THE REGION. SINCE HIGH PRESSURE RIDGING
IS STILL EXPECTED TO EXTEND FROM NEW ENGLAND THROUGH THE LOWER
MISSISSIPPI VALLEY...THE GULF OF MEXICO WILL BE CUT OFF FROM THE
APPROACHING SYSTEM AND THE ONLY AVAILABLE MOISTURE FOR IT TO WORK
WITH WILL BE THE MEAGER AMOUNTS IN PLACE...PWATS AROUND A QUARTER OF
AN INCH AND WHAT MOISTURE IT CAN BRING AS A PACIFIC SOURCED MID
LEVEL SHORTWAVE. THROUGH THE EVENING ON SUNDAY...SFC TEMPERATURES
ARE EXPECTED TO DROP OFF INTO THE UPPER 20S TO THE LOWER 30S. MODEL
SOUNDING FOR SUNDAY NIGHT INTO MONDAY MORNING INDICATE WARMING ABOVE
THE BOUNDARY LAYER WITH TEMPS RISING TO 1-2C ABOVE A SUB-FREEZING
SFC LAYER. THE PCPN TYPE FORECAST FOR SUNDAY NIGHT INTO MONDAY
MORNING WILL BE COMPLICATED BY THE DEPTH AND DEGREE OF THE WARM
LAYER AND HOW FAR NORTH THE WARM LAYER CAN REACH. THE LATEST
GUIDANCE SUGGESTS THAT PCPN SHOULD START OUT AS A LITTLE LIGHT SNOW
OVER THE ROCKFORD AREA EARLY SUNDAY EVENING BEFORE THE WARM
INTRUSION REACHES INTO NCNTRL IL...WITH A TRANSITION OVER TO
FREEZING RAIN AND...PERHAPS...A LITTLE SLEET MIXING IN...WHICH WOULD
BE DEPENDENT ON THE DEPTH OF THE SURFACE-BASED FREEZING LAYER. AS
THE SYSTEM SLOWLY CROSSES THE AREA...MANY LOCATIONS COULD SEE A
PERIOD OF LIGHT FREEZING RAIN LATE SUNDAY NIGHT INTO EARLY MONDAY
MORNING...BEFORE CHANGING OVER TO ALL RAIN BY MIDDAY MONDAY. WITH
AVAILABLE DEEP LAYER MOISTURE STILL LIMITED...WITH PWATS ONLY OF A
HALF INCH OR SO...PCPN AMOUNTS SHOULD BE LIGHT...BUT EVEN A LIGHT
GLAZING OF FREEZING RAIN IN TIME FOR THE MONDAY MORNING RUSH HOURS
COULD CREATE TRAVEL DIFFICULTIES. HOWEVER...HIGH PRESSURE IS
EXPECTED TO QUICKLY BUILD ACROSS THE REGION FOLLOWING THE FRONTAL
PASSAGE...AND ANY PCPN SHOULD COME TO AN END BY LATE MONDAY
AFTERNOON OVER THE WRN PORTIONS OF THE CWA AND IN THE EARLY EVENING
FOR THE FAR SOUTHEAST. TEMPERATURES SHOULD BE HIGH ENOUGH DURG THE
LATE AFTERNOON HOURS THAT THE CHANCES FOR ANY FREEZING PCPN FOR THE
EVENING RUSH HOURS ARE LOW.
AS THE NEXT AREA OF HIGH PRESSURE BUILDS ACROSS THE REGION...A SHORT
PERIOD OF COOL...DRY CONDITIONS WILL PREVAIL THROUGH WEDNESDAY...WITH
HIGHS IN THE LOWER TO MIDDLE 30S AND OVERNIGHT LOWS IN THE UPPER
TEENS TO LOWER 20S. THE SYSTEM PASSING THROUGH THE AREA MONDAY
NIGHT IS EXPECTED TO DEVELOP INTO A DEEP UPPER LOW OVER THE MID
ATLANTIC REGION BY WEDNESDAY AND THEN SLOWLY MOVE UP THE EAST
COAST. BY WEDNESDAY NIGHT...THE DEEP UPPER LOW WILL MOVE OVER NEW
ENGLAND AS UPPER RIDING BUILDS FROM THE SRN ROCKIES THROUGH THE
UPPER MISSISSIPPI VALLEY. A WEAK SHORTWAVE IN THE NLY FLOW ALOFT
BETWEEN THESE TO LARGE SCALE SYSTEMS COULD BRING A BIT OF LIGHT SNOW
FOR WEDNESDAY NIGHT INTO THURSDAY...BUT ANY ASSOCIATED SNOWFALL
SHOULD BE LIGHT. TOWARDS THE END OF THE WEEK..THE UPPER RIDGING IS
EXPECTED TO BUILD ACROSS THE UPPER MIDWEST...BRINGING A WARMING
TREND FOR LATE NEXT WEEK...WITH TEMPS POSSIBLY REACHING THE LOWER TO
MIDDLE 40S BY NEXT FRIDAY.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* CIGS AROUND 1500 FT LIFTING THROUGH MIDDAY AND SCATTERING SOME
TIME LATE THIS AFTERNOON.
* N-NNE WINDS 12-15 KT GUSTING TO 20-25 KT AT TIMES THROUGH THE
AFTERNOON.
KMD
//DISCUSSION...UPDATED 12Z...
LOW PRESSURE CONTINUES TO MOVE NORTHEAST UP THE OHIO RIVER VALLEY
WHILE HIGH PRESSURE MOVES INTO THE UPPER MISSISSIPPI RIVER VALLEY.
STEADIER N TO NE WINDS HAVE SET UP IN THE 10-14 KT RANGE WITH
SPORADIC GUSTS ALSO APPEARING AT TIMES. GUSTS WILL LIKELY BECOME
MORE FREQUENT THIS AFTERNOON ESPECIALLY WHERE BREAKS CAN DEVELOP
IN THE CLOUD COVER. WINDS WILL GRADUALLY DIMINISH AND TURN
NORTHEAST THIS EVENING BEFORE SHIFTING SOUTHEAST TOWARD DAYBREAK
MONDAY.
CIGS WILL BE A CHALLENGE THROUGH THE MORNING. OBS SHOW BASE
HEIGHTS RANGING FROM 600-1100 FT ACROSS THE TERMINALS AND POINTS
UPSTREAM. A SLIGHT WIND COMPONENT OFF THE LAKE SEEMS TO BE KEEPING
BASES A LITTLE HIGHER WITHIN SEVERAL MILES INLAND OF THE SHORE
THANKS TO WARMER AIR OVER THE WATER. SATELLITE IMAGERY SHOWS A
WELL DEFINED BACK EDGE TO THE STRATUS ACROSS SOUTHERN WISCONSIN
WHICH IS MOVING SOUTHEAST. STRATUS IS ALSO EXTENSIVE ACROSS LAKE
MICHIGAN. THE BACK EDGE OF THIS STRATUS WILL LIKELY WORK ACROSS
MOST OF IF NOT ALL OF THE AREA THROUGH AROUND 16Z. HOWEVER...THERE
IS NOT SIGNIFICANT AMOUNTS OF DRY AIR WORKING INTO THE REGION SO
SCT-BKN STRATO CU MAY DEVELOP TOWARD MIDDAY....PROVIDED THE
CURRENT BAND DOES EXIT AND DOES NOT SLOW ITS SOUTHWARD PROGRESS.
IN OTHER WORDS THERE MAY BE A BREAK IN THE LOW CLOUDS BEFORE
DIURNAL CU DEVELOPS. ALSO...FLOW IN THE CLOUD LAYER WILL BE AIMED
FROM THE NORTHEAST RIGHT ACROSS THE LAKE SO LAKE PROCESSES MAY BE
SUFFICIENT TO KEEP STRATUS GOING AT LEAST WITHIN SEVERAL MILES OF
SHORE WELL INTO THE AFTERNOON. WILL GO AHEAD AND KEEP A LONGER
PERIOD OF STRATUS IN THE FORECAST FOR NOW WHICH COULD BE
PESSIMISTIC. OTHERWISE SKIES WILL CLEAR THIS EVENING IF THEY DO
NOT DO SO EARLIER. MORNING VSBY BETWEEN 2-5 SM WILL IMPROVE AS WE
GRADUALLY BEGIN TO WARM UP AFTER DAYBREAK.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* HIGH CONFIDENCE IN CLOUD BASES LIFTING THROUGH MIDDAY...BUT LOW
CONFIDENCE IN TIMING OF SCATTERING.
* HIGH CONFIDENCE IN WIND TRENDS.
KMD
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...MAINLY VFR. SLGT CHANCE OF LIGHT SNOW/SLEET AND
MVFR SUNDAY. E WINDS BECOMING SE.
MONDAY...CHANCE RAIN/SLEET/SNOW. MVFR/BRIEF IFR POSSIBLE. S WINDS
BECOMING W.
TUESDAY...VFR. NW WINDS BECOMING N.
WEDNESDAY...VFR. NE WINDS BECOMING ESE.
THURSDAY...SLGT CHANCE LIGHT SNOW. VFR. S WINDS.
FRIDAY...VFR. SSE WINDS.
MDB
&&
.MARINE...
256 AM CST
LOW PRESSURE CONTINUES TO MOVE NORTHEAST UP THE OHIO RIVER VALLEY
EARLY THIS MORNING WITH STRONG HIGH PRESSURE MOVING EASTWARD ACROSS
THE EASTERN DAKOTAS. WINDS ARE STARTING TO INCREASE AS THE PRESSURE
GRADIENT BETWEEN THESE TWO SYSTEMS TIGHTENS UP THROUGH THE MORNING.
AS A RESULT...EXPECT NORTH TO NORTHEAST WINDS TO RANGE FROM 20 TO 25
KT WITH GUSTS TO 30 KT ACROSS THE CENTRAL AND SOUTHERN PARTS OF THE
LAKE THIS MORNING/AFTERNOON WITH NORTHERN AREAS DIMINISHING THROUGH
THE AFTERNOON AS THE INFLUENCE OF THE HIGH ARRIVES. SPEEDS WILL
DIMINISH ACROSS THE LAKE THIS EVENING AND TONIGHT AS THE DIRECTION
TURNS EAST THEN SOUTHEAST AS THE HIGH SHIFTS TO THE EAST. WILL
CONTINUE WITH THE SMALL CRAFT ADVISORY INTO EARLY TONIGHT AS THE
LONG FETCH OF WIND WILL KEEP WAVES ELEVATED AFTER WINDS DIMINISH THIS
EVENING.
LOW PRESSURE WILL DEVELOP IN THE LEE OF THE NORTHERN ROCKIES SUNDAY
AND MOVE EASTWARD ALONG THE U.S./CANADIAN BORDER...CROSSING LAKE
SUPERIOR MONDAY EVENING. THE LOW WILL DRAG A COLD FRONT ACROSS THE
LAKE MONDAY EVENING. SOUTHERLY WINDS WILL INCREASE AHEAD OF THE LOW
SUNDAY AND SUNDAY NIGHT THEN SHIFT TO THE NORTHWEST BEHIND THE FRONT
MONDAY NIGHT. STRONG HIGH PRESSURE WILL BUILD IN BEHIND THE LOW INTO
TUESDAY WITH A FAIRLY STRONG PUSH OF COLDER AIR AND A TIGHT PRESSURE
GRADIENT SUPPORTING GUSTY NORTH TO NORTHWEST WINDS. WINDS WILL
DIMINISH WEDNESDAY AS THE HIGH MOVES OVERHEAD.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 3 AM SUNDAY.
&&
$$
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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
610 AM CST Sat Dec 6 2014
.SHORT TERM...(Today)
ISSUED AT 323 AM CST SAT DEC 6 2014
The 08z/2am surface analysis has a 1015mb low in NC Kentucky moving
northeast along a stationary front. Rain showers on the NW flank of
the low are steadily progressing eastward out of our E-SE counties.
The back edge of precip should reach I-57 by 09z/3am and be
completely out of our IL counties by 13z/7am.
Despite dry air aloft flowing into Illinois on N-NW winds, a strong
subsidence inversion is indicated in all the short term models. That
will limit mixing of the dry air in to the low level moisture, and
work to keep clouds across our forecast area over the next 12 hours
if not well into tonight. The satellite images are showing a
clearing line progressing south toward IL across MN/WI, however,
that clearing should slow down with the intensification of the
inversion today. High temps will not climb appreciably under the
blanket of clouds, with readings topping out in the upper 30s toward
Galesburg and into the mid 40s toward Lawrenceville.
&&
.LONG TERM...(Tonight through Friday)
ISSUED AT 323 AM CST SAT DEC 6 2014
High pressure continues to build into the region, although the
inversion remains and will likely see a continuation of the clouds
until the incredibly dry air aloft finally works its way down into
the higher RH in the llvls. This same dry air is also the deciding
factor in the next issue for the forecast with an approaching wave
Sun night/Monday. Prev models had more disagreement and the NAM
with a more southerly track for the wave was the outlier. With this
run, both the GFS and ECMWF starting to look a lot more like the
prev NAM. A small system developing into a larger upper trof late
in the weekend...with the look of two smaller waves bringing pops
back into the region. Although the GFS and the ECMWF are more
consistent with the prev NAM, the NAM is far more scarce with the
QPF. Keeping the forecast chances low for shower activity after
midnight Sun night/Monday... not only for lack of continuity from
run to run, but the considerable amount of dry air will take a while
to overcome. Not convinced the best lift will coincide with the
eventual saturation of the column.
Beyond Monday and its cold front, temps cool briefly, then moderate
back into the 40s for highs through the end of the week. 00z ECMWF
completely pulls back on a small disturbance Wed night/Thursday, and
should this trend continue, will likely pull the pops altogether out
of the next couple runs. For now, slight pops in the forecast to
cover a brief disturbance diving into the Great Lakes region on the
retreating edge of the larger scale 500 mb trof exiting out to the
northeast. This difference btwn the GFS and the European also
delineates the break point in the extended between any agreement in
the midst of a small pattern shift. Depth of the thickness ridge
going into day 7 and 8 will definitely result in some blend issues
going into next weekend.
&&
.AVIATION...(For the 12Z TAFS through 12Z Sunday morning)
ISSUED AT 600 AM CST SAT DEC 6 2014
The cloud forecast will continue to be challenging over the next
24 hours, as a clearing line approaches central IL from the north.
However, the HRRR and NAM keep low clouds entrenched until later this
evening, while the GFS dissipates the low clouds this morning.
The HRRR does show the brief small area of break in the low clouds
that drifted across the area the last 6 hours, but it also indicates
that break will fill in and the clearing line will barely graze our NW
counties this afternoon, but not reach all the way to PIA.
The NAM/SREF/RAP forecast soundings all show a strong subsidence
inversion trapping the low level moisture across our terminal
sites today. So confidence is moderate in keeping low clouds in
place through the day. Ceiling heights will start out LIFR at
BMI/DEC and IFR at PIA/CMI/SPI. All ceilings should at least climb
to MVFR after 18z with heating of the day and lifting of the LCL.
We went with some clearing eventually developing tonight with
advancing high pressure and a deeper layer of dry air.
Winds will remain north today at 10-14kt and shift to northeast
tonight as they diminish below 10kt.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Shimon
LONG TERM...HJS
AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1137 AM EST SAT DEC 6 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 356 AM EST SAT DEC 6 2014
RAINFALL WILL COME TO AN END TODAY AS LOW PRESSURE GRADUALLY EXITS
THE REGION. CLOUD COVER WILL PERSIST HOWEVER AS AMPLE LOW LEVEL
MOISTURE REMAINS TRAPPED UNDER A STRONG INVERSION. DRY WEATHER
WILL CONTINUE THROUGH SUNDAY NIGHT AS HIGH PRESSURE DOMINATES THE
REGION. A SURFACE AND UPPER LEVEL TROUGH PASSING THROUGH THE GREAT
LAKES MONDAY AND MONDAY NIGHT MAY PRODUCE SOME LIGHT RAIN ACROSS
PORTIONS OF THE AREA. DRY WEATHER IS EXPECTED FOR THE REMAINDER OF
THE FORECAST PERIOD.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 948 AM EST SAT DEC 6 2014
RAINFALL HAS EXITED THE FORECAST AREA FOR THE MOST PART...SO WILL
TAKE OUT POPS FOR THE REST OF THE DAY.
SHORT TERM MODELS SUGGEST LITTLE CHANCE OF ANY SIGNIFICANT CLEARING
TODAY. THICK CLOUD COVER COMBINED WITH LOW LEVEL COLD ADVECTION
SUGGESTS ONLY SUBTLE TEMPERATURE RISES FOR THE REST OF THE DAY.
PREVIOUS DISCUSSION FOLLOWS.
BETWEEN HRRR AND EXTRAPOLATION FROM LATEST RADAR TRENDS...EXPECT
PRECIPITATION TO COME TO AN END ACROSS CENTRAL INDIANA BY
NOON...AND WILL RAPIDLY TAPER OFF POPS AS SUCH FROM WEST TO EAST.
STRONG LOW LEVEL INVERSION WILL REMAIN ACROSS THE AREA IN THE WAKE
OF THE LOW PRESSURE SYSTEM WITH MOISTURE TRAPPED...THUS IT APPEARS
THAT MODEL GUIDANCE IS CLEARING SKIES OUT FAR TOO QUICKLY. HAVE
DELAYED ANY CLEARING WHATSOEVER INTO THE AFTERNOON AND THERE IS
SOME CHANCE EVEN THIS IS TOO EARLY.
LEANED SLIGHTLY COOLER THAN GUIDANCE AS A RESULT OF THIS AMPLE
CLOUD COVER AND ONGOING COLD ADVECTION THROUGH THE DAY. MAY SEE
HIGH TEMPERATURES EARLY IN THE DAY IN SOME LOCATIONS WITH
TEMPERATURES STEADY OR SLOWLY FALLING LATE IN THE DAY.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
ISSUED AT 356 AM EST SAT DEC 6 2014
LATEST MODELS ARE COMING IN WETTER WITH THE SURFACE AND UPPER
LEVEL TROUGH PASSING THROUGH THE AREA MONDAY INTO MONDAY NIGHT.
WILL HAVE TO CARRY SOME POPS MONDAY AND INTO MONDAY EVENING...BUT
WITH SOUNDINGS ONLY BRIEFLY SATURATING MONDAY...AND DRYING QUICKLY
FROM ALOFT LATE MONDAY NIGHT...WILL GO NO FURTHER THAN LOW CHANCE
POPS AND WILL END PRECIP BY 06Z MONDAY NIGHT.
MONDAY EVENING...PRECIP MAY COME MORE IN THE FORM OF DRIZZLE AS
DRY AIR WORKS INTO THE AREA ALOFT BUT WITH WEAKLY POSITIVE OMEGA
NOTED IN MOIST LOW LEVELS. EXPECT THAT PRECIP WILL HAVE ENDED BY
THE TIME ANY FREEZING OR NEAR FREEZING TEMPERATURES MOVE INTO THE
AREA.
MODEL CONSENSUS APPEARED TO TRACK RELATIVELY WELL WITH LOW LEVEL
THICKNESS PROGS...ASIDE FROM A FEW MINOR TWEAKS.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 220 AM EST SAT DEC 6 2014
DRY WEATHER IS EXPECTED THIS PERIOD AS THE GFS SHOWS A DEPARTING
TROUGH OF LOW PRESSURE ON TUESDAY AND HIGH PRESSURE OVER THE
PLAINS STATES BEGINNING TO BUILD ACROSS THE AREA FOR THE MIDDLE OF
THE NEXT WORK WEEK.
AS THE SURFACE HIGH PUSHES EAST OF INDIANA ON THURSDAY THE GFS
DEPICTS ABUNDANT MOISTURE ALOFT IN THE RETURN FLOW. MEANWHILE THE
ECMWF IS MUCH LESS AGGRESSIVE. GIVEN THE LACK OF DYNAMICS
ALOFT...HAVE LEANED TOWARD THE DRYER ECMWF SOLUTION FOR NOW.
STRONG RIDGING BUILDS ALOFT AS THE WORK WEEK COMES TO AN END...AS
SOUTHERLY TO SOUTHWEST SURFACE WINDS KEEP COLDER ARCTIC AIR AT
BAY. THUS WILL CONTINUE THROUGH THE PERIOD WITH AT OR ABOVE NORMAL
TEMPERATURES.
&&
.AVIATION /DISCUSSION FOR THE 061800Z TAFS/...
ISSUED AT 1137 AM EST SAT DEC 6 2014
A LARGE AREA OF MVFR CEILINGS 015-025 CURRENTLY ACROSS THE AREA.
SHORT TERM MODELS SUGGEST THESE CONDITIONS WILL HOLD THROUGH THE
EVENING HOURS...WITH THE POTENTIAL FOR SCATTERING OUT OF THE
CEILINGS FROM NORTH TO SOUTH TOWARDS 070600Z.
SURFACE WIND GUSTS 20-22 KTS FROM 360-020 DEGREES SHOULD CONTINUE
FOR THE AFTERNOON HOURS...DIMINISHING AROUND SUNSET.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...NIELD
NEAR TERM...NIELD/JAS
SHORT TERM...NIELD
LONG TERM...PUMA
AVIATION...JAS
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AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
948 AM EST SAT DEC 6 2014
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 356 AM EST SAT DEC 6 2014
RAINFALL WILL COME TO AN END TODAY AS LOW PRESSURE GRADUALLY EXITS
THE REGION. CLOUD COVER WILL PERSIST HOWEVER AS AMPLE LOW LEVEL
MOISTURE REMAINS TRAPPED UNDER A STRONG INVERSION. DRY WEATHER
WILL CONTINUE THROUGH SUNDAY NIGHT AS HIGH PRESSURE DOMINATES THE
REGION. A SURFACE AND UPPER LEVEL TROUGH PASSING THROUGH THE GREAT
LAKES MONDAY AND MONDAY NIGHT MAY PRODUCE SOME LIGHT RAIN ACROSS
PORTIONS OF THE AREA. DRY WEATHER IS EXPECTED FOR THE REMAINDER OF
THE FORECAST PERIOD.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 948 AM EST SAT DEC 6 2014
RAINFALL HAS EXITED THE FORECAST AREA FOR THE MOST PART...SO WILL
TAKE OUT POPS FOR THE REST OF THE DAY.
SHORT TERM MODELS SUGGEST LITTLE CHANCE OF ANY SIGNIFICANT CLEARING
TODAY. THICK CLOUD COVER COMBINED WITH LOW LEVEL COLD ADVECTION
SUGGESTS ONLY SUBTLE TEMPERATURE RISES FOR THE REST OF THE DAY.
PREVIOUS DISCUSSION FOLLOWS.
BETWEEN HRRR AND EXTRAPOLATION FROM LATEST RADAR TRENDS...EXPECT
PRECIPITATION TO COME TO AN END ACROSS CENTRAL INDIANA BY
NOON...AND WILL RAPIDLY TAPER OFF POPS AS SUCH FROM WEST TO EAST.
STRONG LOW LEVEL INVERSION WILL REMAIN ACROSS THE AREA IN THE WAKE
OF THE LOW PRESSURE SYSTEM WITH MOISTURE TRAPPED...THUS IT APPEARS
THAT MODEL GUIDANCE IS CLEARING SKIES OUT FAR TOO QUICKLY. HAVE
DELAYED ANY CLEARING WHATSOEVER INTO THE AFTERNOON AND THERE IS
SOME CHANCE EVEN THIS IS TOO EARLY.
LEANED SLIGHTLY COOLER THAN GUIDANCE AS A RESULT OF THIS AMPLE
CLOUD COVER AND ONGOING COLD ADVECTION THROUGH THE DAY. MAY SEE
HIGH TEMPERATURES EARLY IN THE DAY IN SOME LOCATIONS WITH
TEMPERATURES STEADY OR SLOWLY FALLING LATE IN THE DAY.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
ISSUED AT 356 AM EST SAT DEC 6 2014
LATEST MODELS ARE COMING IN WETTER WITH THE SURFACE AND UPPER
LEVEL TROUGH PASSING THROUGH THE AREA MONDAY INTO MONDAY NIGHT.
WILL HAVE TO CARRY SOME POPS MONDAY AND INTO MONDAY EVENING...BUT
WITH SOUNDINGS ONLY BRIEFLY SATURATING MONDAY...AND DRYING QUICKLY
FROM ALOFT LATE MONDAY NIGHT...WILL GO NO FURTHER THAN LOW CHANCE
POPS AND WILL END PRECIP BY 06Z MONDAY NIGHT.
MONDAY EVENING...PRECIP MAY COME MORE IN THE FORM OF DRIZZLE AS
DRY AIR WORKS INTO THE AREA ALOFT BUT WITH WEAKLY POSITIVE OMEGA
NOTED IN MOIST LOW LEVELS. EXPECT THAT PRECIP WILL HAVE ENDED BY
THE TIME ANY FREEZING OR NEAR FREEZING TEMPERATURES MOVE INTO THE
AREA.
MODEL CONSENSUS APPEARED TO TRACK RELATIVELY WELL WITH LOW LEVEL
THICKNESS PROGS...ASIDE FROM A FEW MINOR TWEAKS.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 220 AM EST SAT DEC 6 2014
DRY WEATHER IS EXPECTED THIS PERIOD AS THE GFS SHOWS A DEPARTING
TROUGH OF LOW PRESSURE ON TUESDAY AND HIGH PRESSURE OVER THE
PLAINS STATES BEGINNING TO BUILD ACROSS THE AREA FOR THE MIDDLE OF
THE NEXT WORK WEEK.
AS THE SURFACE HIGH PUSHES EAST OF INDIANA ON THURSDAY THE GFS
DEPICTS ABUNDANT MOISTURE ALOFT IN THE RETURN FLOW. MEANWHILE THE
ECMWF IS MUCH LESS AGGRESSIVE. GIVEN THE LACK OF DYNAMICS
ALOFT...HAVE LEANED TOWARD THE DRYER ECMWF SOLUTION FOR NOW.
STRONG RIDGING BUILDS ALOFT AS THE WORK WEEK COMES TO AN END...AS
SOUTHERLY TO SOUTHWEST SURFACE WINDS KEEP COLDER ARCTIC AIR AT
BAY. THUS WILL CONTINUE THROUGH THE PERIOD WITH AT OR ABOVE NORMAL
TEMPERATURES.
&&
.AVIATION /DISCUSSION FOR THE 061500Z KIND TAF UPDATE/...
ISSUED AT 921 AM EST SAT DEC 6 2014
A LARGE AREA OF MAINLY MVFR VISIBILITY RESTRICTIONS IN LIGHT FOG
CONTINUES ACROSS THE AREA...SO IT WILL PROBABLY BE SEVERAL MORE
HOURS BEFORE VISIBILITIES IMPROVE. WILL LOWER THE VISIBILITY
FORECAST INTO THE MVFR CATEGORY INTO THE EARLY AFTERNOON ON THE
UPDATE.
PREVIOUS DISCUSSION FOLLOWS.
IFR CONDITIONS WILL IMPROVE TO MVFR LATE THIS MORNING BEFORE
IMPROVING TO VFR OVERNIGHT.
SATELLITE CONTINUES TO SHOW EXTENSIVE CLOUDINESS ACROSS
INDIANA...ILLINOIS..MISSOURI AND IOWA. SURFACE ANALYSIS EARLY THIS
MORNING SHOWS LOW PRESSURE OVER EASTERN KENTUCKY...PULLING
NORTHEAST. RADAR SHOWS THE BACK EDGE OF PRECIP ALONG A LAF/HUF
LINE...PUSHING EAST.
SHOWERS ARE EXPECTED TO END BY 14Z AT ALL THE TAF SITES...HOWEVER
EXTENSIVE CLOUDS WILL REMAIN AS TIME HEIGHTS SHOW LINGERING LOWER
LEVEL MOISTURE THROUGH THE DAY AND THE PREVIOUSLY MENTIONED
UPSTREAM OBS WITH PLENTIFUL CLOUDINESS. THUS WILL CONTINUE MVFR
CIGS THROUGH MUCH OF THE DAY AS SURFACE HIGH PRESSURE SLOWLY WORKS IN.
RIDGING ALOFT FINALLY BEGINS TO WORK IN OVERNIGHT...AND WILL
TREND TOWARD VFR AT THAT TIME AS ANTICYCLONIC FLOW BECOMES PREDOMINATE.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...NIELD
NEAR TERM...NIELD/JAS
SHORT TERM...NIELD
LONG TERM...PUMA
AVIATION...JP/JAS
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
921 AM EST SAT DEC 6 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 356 AM EST SAT DEC 6 2014
RAINFALL WILL COME TO AN END TODAY AS LOW PRESSURE GRADUALLY EXITS
THE REGION. CLOUD COVER WILL PERSIST HOWEVER AS AMPLE LOW LEVEL
MOISTURE REMAINS TRAPPED UNDER A STRONG INVERSION. DRY WEATHER
WILL CONTINUE THROUGH SUNDAY NIGHT AS HIGH PRESSURE DOMINATES THE
REGION. A SURFACE AND UPPER LEVEL TROUGH PASSING THROUGH THE GREAT
LAKES MONDAY AND MONDAY NIGHT MAY PRODUCE SOME LIGHT RAIN ACROSS
PORTIONS OF THE AREA. DRY WEATHER IS EXPECTED FOR THE REMAINDER OF
THE FORECAST PERIOD.
&&
.NEAR TERM /TODAY/...
ISSUED AT 356 AM EST SAT DEC 6 2014
BETWEEN HRRR AND EXTRAPOLATION FROM LATEST RADAR TRENDS...EXPECT
PRECIPITATION TO COME TO AN END ACROSS CENTRAL INDIANA BY
NOON...AND WILL RAPIDLY TAPER OFF POPS AS SUCH FROM WEST TO EAST.
STRONG LOW LEVEL INVERSION WILL REMAIN ACROSS THE AREA IN THE WAKE
OF THE LOW PRESSURE SYSTEM WITH MOISTURE TRAPPED...THUS IT APPEARS
THAT MODEL GUIDANCE IS CLEARING SKIES OUT FAR TOO QUICKLY. HAVE
DELAYED ANY CLEARING WHATSOEVER INTO THE AFTERNOON AND THERE IS
SOME CHANCE EVEN THIS IS TOO EARLY.
LEANED SLIGHTLY COOLER THAN GUIDANCE AS A RESULT OF THIS AMPLE
CLOUD COVER AND ONGOING COLD ADVECTION THROUGH THE DAY. MAY SEE
HIGH TEMPERATURES EARLY IN THE DAY IN SOME LOCATIONS WITH
TEMPERATURES STEADY OR SLOWLY FALLING LATE IN THE DAY.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
ISSUED AT 356 AM EST SAT DEC 6 2014
LATEST MODELS ARE COMING IN WETTER WITH THE SURFACE AND UPPER
LEVEL TROUGH PASSING THROUGH THE AREA MONDAY INTO MONDAY NIGHT.
WILL HAVE TO CARRY SOME POPS MONDAY AND INTO MONDAY EVENING...BUT
WITH SOUNDINGS ONLY BRIEFLY SATURATING MONDAY...AND DRYING QUICKLY
FROM ALOFT LATE MONDAY NIGHT...WILL GO NO FURTHER THAN LOW CHANCE
POPS AND WILL END PRECIP BY 06Z MONDAY NIGHT.
MONDAY EVENING...PRECIP MAY COME MORE IN THE FORM OF DRIZZLE AS
DRY AIR WORKS INTO THE AREA ALOFT BUT WITH WEAKLY POSITIVE OMEGA
NOTED IN MOIST LOW LEVELS. EXPECT THAT PRECIP WILL HAVE ENDED BY
THE TIME ANY FREEZING OR NEAR FREEZING TEMPERATURES MOVE INTO THE
AREA.
MODEL CONSENSUS APPEARED TO TRACK RELATIVELY WELL WITH LOW LEVEL
THICKNESS PROGS...ASIDE FROM A FEW MINOR TWEAKS.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 220 AM EST SAT DEC 6 2014
DRY WEATHER IS EXPECTED THIS PERIOD AS THE GFS SHOWS A DEPARTING
TROUGH OF LOW PRESSURE ON TUESDAY AND HIGH PRESSURE OVER THE
PLAINS STATES BEGINNING TO BUILD ACROSS THE AREA FOR THE MIDDLE OF
THE NEXT WORK WEEK.
AS THE SURFACE HIGH PUSHES EAST OF INDIANA ON THURSDAY THE GFS
DEPICTS ABUNDANT MOISTURE ALOFT IN THE RETURN FLOW. MEANWHILE THE
ECMWF IS MUCH LESS AGGRESSIVE. GIVEN THE LACK OF DYNAMICS
ALOFT...HAVE LEANED TOWARD THE DRYER ECMWF SOLUTION FOR NOW.
STRONG RIDGING BUILDS ALOFT AS THE WORK WEEK COMES TO AN END...AS
SOUTHERLY TO SOUTHWEST SURFACE WINDS KEEP COLDER ARCTIC AIR AT
BAY. THUS WILL CONTINUE THROUGH THE PERIOD WITH AT OR ABOVE NORMAL
TEMPERATURES.
&&
.AVIATION /DISCUSSION FOR THE 061500Z KIND TAF UPDATE/...
ISSUED AT 921 AM EST SAT DEC 6 2014
A LARGE AREA OF MAINLY MVFR VISIBILITY RESTRICTIONS IN LIGHT FOG
CONTINUES ACROSS THE AREA...SO IT WILL PROBABLY BE SEVERAL MORE
HOURS BEFORE VISIBILITIES IMPROVE. WILL LOWER THE VISIBILITY
FORECAST INTO THE MVFR CATEGORY INTO THE EARLY AFTERNOON ON THE
UPDATE.
PREVIOUS DISCUSSION FOLLOWS.
IFR CONDITIONS WILL IMPROVE TO MVFR LATE THIS MORNING BEFORE
IMPROVING TO VFR OVERNIGHT.
SATELLITE CONTINUES TO SHOW EXTENSIVE CLOUDINESS ACROSS
INDIANA...ILLINOIS..MISSOURI AND IOWA. SURFACE ANALYSIS EARLY THIS
MORNING SHOWS LOW PRESSURE OVER EASTERN KENTUCKY...PULLING
NORTHEAST. RADAR SHOWS THE BACK EDGE OF PRECIP ALONG A LAF/HUF
LINE...PUSHING EAST.
SHOWERS ARE EXPECTED TO END BY 14Z AT ALL THE TAF SITES...HOWEVER
EXTENSIVE CLOUDS WILL REMAIN AS TIME HEIGHTS SHOW LINGERING LOWER
LEVEL MOISTURE THROUGH THE DAY AND THE PREVIOUSLY MENTIONED
UPSTREAM OBS WITH PLENTIFUL CLOUDINESS. THUS WILL CONTINUE MVFR
CIGS THROUGH MUCH OF THE DAY AS SURFACE HIGH PRESSURE SLOWLY WORKS IN.
RIDGING ALOFT FINALLY BEGINS TO WORK IN OVERNIGHT...AND WILL
TREND TOWARD VFR AT THAT TIME AS ANTICYCLONIC FLOW BECOMES PREDOMINATE.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...NIELD
NEAR TERM...NIELD
SHORT TERM...NIELD
LONG TERM...PUMA
AVIATION...JP/JAS
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
553 AM EST SAT DEC 6 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 356 AM EST SAT DEC 6 2014
RAINFALL WILL COME TO AN END TODAY AS LOW PRESSURE GRADUALLY EXITS
THE REGION. CLOUD COVER WILL PERSIST HOWEVER AS AMPLE LOW LEVEL
MOISTURE REMAINS TRAPPED UNDER A STRONG INVERSION. DRY WEATHER
WILL CONTINUE THROUGH SUNDAY NIGHT AS HIGH PRESSURE DOMINATES THE
REGION. A SURFACE AND UPPER LEVEL TROUGH PASSING THROUGH THE GREAT
LAKES MONDAY AND MONDAY NIGHT MAY PRODUCE SOME LIGHT RAIN ACROSS
PORTIONS OF THE AREA. DRY WEATHER IS EXPECTED FOR THE REMAINDER OF
THE FORECAST PERIOD.
&&
.NEAR TERM /TODAY/...
ISSUED AT 356 AM EST SAT DEC 6 2014
BETWEEN HRRR AND EXTRAPOLATION FROM LATEST RADAR TRENDS...EXPECT
PRECIPITATION TO COME TO AN END ACROSS CENTRAL INDIANA BY
NOON...AND WILL RAPIDLY TAPER OFF POPS AS SUCH FROM WEST TO EAST.
STRONG LOW LEVEL INVERSION WILL REMAIN ACROSS THE AREA IN THE WAKE
OF THE LOW PRESSURE SYSTEM WITH MOISTURE TRAPPED...THUS IT APPEARS
THAT MODEL GUIDANCE IS CLEARING SKIES OUT FAR TOO QUICKLY. HAVE
DELAYED ANY CLEARING WHATSOEVER INTO THE AFTERNOON AND THERE IS
SOME CHANCE EVEN THIS IS TOO EARLY.
LEANED SLIGHTLY COOLER THAN GUIDANCE AS A RESULT OF THIS AMPLE
CLOUD COVER AND ONGOING COLD ADVECTION THROUGH THE DAY. MAY SEE
HIGH TEMPERATURES EARLY IN THE DAY IN SOME LOCATIONS WITH
TEMPERATURES STEADY OR SLOWLY FALLING LATE IN THE DAY.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
ISSUED AT 356 AM EST SAT DEC 6 2014
LATEST MODELS ARE COMING IN WETTER WITH THE SURFACE AND UPPER
LEVEL TROUGH PASSING THROUGH THE AREA MONDAY INTO MONDAY NIGHT.
WILL HAVE TO CARRY SOME POPS MONDAY AND INTO MONDAY EVENING...BUT
WITH SOUNDINGS ONLY BRIEFLY SATURATING MONDAY...AND DRYING QUICKLY
FROM ALOFT LATE MONDAY NIGHT...WILL GO NO FURTHER THAN LOW CHANCE
POPS AND WILL END PRECIP BY 06Z MONDAY NIGHT.
MONDAY EVENING...PRECIP MAY COME MORE IN THE FORM OF DRIZZLE AS
DRY AIR WORKS INTO THE AREA ALOFT BUT WITH WEAKLY POSITIVE OMEGA
NOTED IN MOIST LOW LEVELS. EXPECT THAT PRECIP WILL HAVE ENDED BY
THE TIME ANY FREEZING OR NEAR FREEZING TEMPERATURES MOVE INTO THE
AREA.
MODEL CONSENSUS APPEARED TO TRACK RELATIVELY WELL WITH LOW LEVEL
THICKNESS PROGS...ASIDE FROM A FEW MINOR TWEAKS.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 220 AM EST SAT DEC 6 2014
DRY WEATHER IS EXPECTED THIS PERIOD AS THE GFS SHOWS A DEPARTING
TROUGH OF LOW PRESSURE ON TUESDAY AND HIGH PRESSURE OVER THE
PLAINS STATES BEGINNING TO BUILD ACROSS THE AREA FOR THE MIDDLE OF
THE NEXT WORK WEEK.
AS THE SURFACE HIGH PUSHES EAST OF INDIANA ON THURSDAY THE GFS
DEPICTS ABUNDANT MOISTURE ALOFT IN THE RETURN FLOW. MEANWHILE THE
ECMWF IS MUCH LESS AGGRESSIVE. GIVEN THE LACK OF DYNAMICS
ALOFT...HAVE LEANED TOWARD THE DRYER ECMWF SOLUTION FOR NOW.
STRONG RIDGING BUILDS ALOFT AS THE WORK WEEK COMES TO AN END...AS
SOUTHERLY TO SOUTHWEST SURFACE WINDS KEEP COLDER ARCTIC AIR AT
BAY. THUS WILL CONTINUE THROUGH THE PERIOD WITH AT OR ABOVE NORMAL
TEMPERATURES.
&&
.AVIATION /DISCUSSION FOR THE 061200Z TAFS/...
ISSUED AT 529 AM EST SAT DEC 6 2014
IFR CONDITIONS WILL IMPROVE TO MVFR LATE THIS MORNING BEFORE
IMPROVING TO VFR OVERNIGHT.
SATELLITE CONTINUES TO SHOW EXTENSIVE CLOUDINESS ACROSS
INDIANA...ILLINOIS..MISSOURI AND IOWA. SURFACE ANALYSIS EARLY THIS
MORNING SHOWS LOW PRESSURE OVER EASTERN KENTUCKY...PULLING
NORTHEAST. RADAR SHOWS THE BACK EDGE OF PRECIP ALONG A LAF/HUF
LINE...PUSHING EAST.
SHOWERS ARE EXPECTED TO END BY 14Z AT ALL THE TAF SITES...HOWEVER
EXTENSIVE CLOUDS WILL REMAIN AS TIME HEIGHTS SHOW LINGERING LOWER
LEVEL MOISTURE THROUGH THE DAY AND THE PREVIOUSLY MENTIONED
UPSTREAM OBS WITH PLENTIFUL CLOUDINESS. THUS WILL CONTINUE MVFR
CIGS THROUGH MUCH OF THE DAY AS SURFACE HIGH PRESSURE SLOWLY WORKS IN.
RIDGING ALOFT FINALLY BEGINS TO WORK IN OVERNIGHT...AND WILL
TREND TOWARD VFR AT THAT TIME AS ANTICYCLONIC FLOW BECOMES PREDOMINATE.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...NIELD
NEAR TERM...NIELD
SHORT TERM...NIELD
LONG TERM...PUMA
AVIATION...JP
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
356 AM EST SAT DEC 6 2014
.UPDATE...
THE SYNOPSIS...NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN
UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 356 AM EST SAT DEC 6 2014
RAINFALL WILL COME TO AN END TODAY AS LOW PRESSURE GRADUALLY EXITS
THE REGION. CLOUD COVER WILL PERSIST HOWEVER AS AMPLE LOW LEVEL
MOISTURE REMAINS TRAPPED UNDER A STRONG INVERSION. DRY WEATHER
WILL CONTINUE THROUGH SUNDAY NIGHT AS HIGH PRESSURE DOMINATES THE
REGION. A SURFACE AND UPPER LEVEL TROUGH PASSING THROUGH THE GREAT
LAKES MONDAY AND MONDAY NIGHT MAY PRODUCE SOME LIGHT RAIN ACROSS
PORTIONS OF THE AREA. DRY WEATHER IS EXPECTED FOR THE REMAINDER OF
THE FORECAST PERIOD.
&&
.NEAR TERM /TODAY/...
ISSUED AT 356 AM EST SAT DEC 6 2014
BETWEEN HRRR AND EXTRAPOLATION FROM LATEST RADAR TRENDS...EXPECT
PRECIPITATION TO COME TO AN END ACROSS CENTRAL INDIANA BY
NOON...AND WILL RAPIDLY TAPER OFF POPS AS SUCH FROM WEST TO EAST.
STRONG LOW LEVEL INVERSION WILL REMAIN ACROSS THE AREA IN THE WAKE
OF THE LOW PRESSURE SYSTEM WITH MOISTURE TRAPPED...THUS IT APPEARS
THAT MODEL GUIDANCE IS CLEARING SKIES OUT FAR TOO QUICKLY. HAVE
DELAYED ANY CLEARING WHATSOEVER INTO THE AFTERNOON AND THERE IS
SOME CHANCE EVEN THIS IS TOO EARLY.
LEANED SLIGHTLY COOLER THAN GUIDANCE AS A RESULT OF THIS AMPLE
CLOUD COVER AND ONGOING COLD ADVECTION THROUGH THE DAY. MAY SEE
HIGH TEMPERATURES EARLY IN THE DAY IN SOME LOCATIONS WITH
TEMPERATURES STEADY OR SLOWLY FALLING LATE IN THE DAY.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
ISSUED AT 356 AM EST SAT DEC 6 2014
LATEST MODELS ARE COMING IN WETTER WITH THE SURFACE AND UPPER
LEVEL TROUGH PASSING THROUGH THE AREA MONDAY INTO MONDAY NIGHT.
WILL HAVE TO CARRY SOME POPS MONDAY AND INTO MONDAY EVENING...BUT
WITH SOUNDINGS ONLY BRIEFLY SATURATING MONDAY...AND DRYING QUICKLY
FROM ALOFT LATE MONDAY NIGHT...WILL GO NO FURTHER THAN LOW CHANCE
POPS AND WILL END PRECIP BY 06Z MONDAY NIGHT.
MONDAY EVENING...PRECIP MAY COME MORE IN THE FORM OF DRIZZLE AS
DRY AIR WORKS INTO THE AREA ALOFT BUT WITH WEAKLY POSITIVE OMEGA
NOTED IN MOIST LOW LEVELS. EXPECT THAT PRECIP WILL HAVE ENDED BY
THE TIME ANY FREEZING OR NEAR FREEZING TEMPERATURES MOVE INTO THE
AREA.
MODEL CONSENSUS APPEARED TO TRACK RELATIVELY WELL WITH LOW LEVEL
THICKNESS PROGS...ASIDE FROM A FEW MINOR TWEAKS.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 220 AM EST SAT DEC 6 2014
DRY WEATHER IS EXPECTED THIS PERIOD AS THE GFS SHOWS A DEPARTING
TROUGH OF LOW PRESSURE ON TUESDAY AND HIGH PRESSURE OVER THE
PLAINS STATES BEGINNING TO BUILD ACROSS THE AREA FOR THE MIDDLE OF
THE NEXT WORK WEEK.
AS THE SURFACE HIGH PUSHES EAST OF INDIANA ON THURSDAY THE GFS
DEPICTS ABUNDANT MOISTURE ALOFT IN THE RETURN FLOW. MEANWHILE THE
ECMWF IS MUCH LESS AGGRESSIVE. GIVEN THE LACK OF DYNAMICS
ALOFT...HAVE LEANED TOWARD THE DRYER ECMWF SOLUTION FOR NOW.
STRONG RIDGING BUILDS ALOFT AS THE WORK WEEK COMES TO AN END...AS
SOUTHERLY TO SOUTHWEST SURFACE WINDS KEEP COLDER ARCTIC AIR AT
BAY. THUS WILL CONTINUE THROUGH THE PERIOD WITH AT OR ABOVE NORMAL
TEMPERATURES.
&&
.AVIATION /DISCUSSION FOR THE 060900Z IND TAF UPDATE/...
RADAR TRENDS SUGGEST AT LAST THE END OF THE RAIN FALL IS NEAR.
BACK EDGE OF PRECIP APPEARS OVER EAST CENTRAL
ILLINOIS...PROGRESSING EASTWARD. OBS UPSTREAM STILL SHOW EXTENSIVE MVFR
TO IFR CONDITIONS. THUS BASED UPON LATEST TRENDS...EXPECT ONE MORE
PERIOD OF LIGHT RAIN AT IND AS THE BACK EDGE OF THE PRECIP WORKS
ACROSS THE STATE.
IMPROVEMENT TO VFR STILL APPEARS GRADUAL AND HEATING...MIXING AND
DRIER AIR ARRIVING ON NORTHERLY WINDS BY LATE THIS MORNING.
/DISCUSSION FOR THE 060600Z TAF ISSUANCE/...
ISSUED AT 1030 PM EST FRI DEC 5 2014
IFR AND WORSE CONDITIONS EXPECTED TO BE THE MOST PREVALENT FLIGHT
CATEGORIES THROUGH THE NIGHT.
RADAR TRENDS AND 02Z RAPID REFRESH REFLECTIVITY PROGS SUGGEST THE
RAIN WILL CONTINUE THROUGH THE NIGHT WITH MOSTLY A LIGHT INTENSITY
BEFORE ENDING AFTER 09Z AT LAF...11Z AT HUF...12Z AT IND AND 13Z AT
BMG. SHOULD SEE CONDITIONS IMPROVE TO MVFR AFTER 12Z FROM NORTHWEST
TO SOUTHEAST. DO NOT EXPECT MUCH CLEARING OVERNIGHT SATURDAY
NIGHT...BUT COULD SEE A FEW BREAKS.
WINDS WILL BE BRIEFLY EAST AND NORTHEAST NEAR 10 KNOTS AND THEN
BECOME NORTH AND INCREASE TO NEAR 15 KNOTS OVERNIGHT WITH GUSTS TO
AROUND 20 KNOTS. SPEED AND DIRECTION SHOULD BE SIMILAR DURING THE
DAY AND BECOME NORTHEAST 10 KNOTS OR LESS AFTER 00Z TONIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...NIELD
NEAR TERM...NIELD
SHORT TERM...NIELD
LONG TERM...PUMA
AVIATION...MK/JP
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
340 AM EST SAT DEC 6 2014
.UPDATE...
AVIATION SECTIONS UPDATED.
&&
.SYNOPSIS...
ISSUED AT 347 PM EST FRI DEC 5 2014
WIDESPREAD RAIN WILL CONTINUE THROUGH SATURDAY MORNING AS LOW
PRESSURE TRACKS THROUGH THE OHIO VALLEY. WITH THE EXCEPTION OF A FEW
SHOWERS MONDAY AS LOW PRESSURE PASSES THROUGH THE GREAT LAKES...DRY
AND SEASONABLY COOL WEATHER CAN BE EXPECTED THROUGH MUCH OF NEXT
WEEK.
&&
.NEAR TERM /REST OF TONIGHT/...
ISSUED AT 953 PM EST FRI DEC 5 2014
FORECAST IS IN GOOD SHAPE AND MADE NO MAJOR CHANGES. RAIN WILL
CONTINUE ACROSS THE AREA AS LOW PRESSURE MOVES SOUTH OF CENTRAL
INDIANA AND AN UPPER TROUGH MOVES INTO THE AREA. LATER TONIGHT AS
FORCING SHIFTS EAST...RAIN WILL DIMINISH SOME FROM NORTHWEST TO
SOUTHEAST. WARM AIR WILL REMAIN JUST SOUTH OF THE AREA.
PREVIOUS DISCUSSION FOLLOWS...
RAIN CONTINUES ACROSS THE FORECAST AREA THIS AFTERNOON...AND EXPECT
ONLY TO INCREASE FURTHER IN INTENSITY OVER THE NEXT SEVERAL HOURS
WITH THE APPROACH OF LOW PRESSURE. TEMPS RANGED FROM THE UPPER 30S
NORTH TO UPPER 40S ACROSS FAR SOUTHERN COUNTIES AT 20Z.
A RAW WET NIGHT UPCOMING AS LOW PRESSURE CURRENTLY OVER THE OZARKS
TRACKS E/NE ALONG THE OHIO RIVER TONIGHT. MODEL GUIDANCE IN
EXCELLENT AGREEMENT ON SPREADING ANOTHER WAVE OF HEAVIER CONVECTIVE
RAINFALL INTO THE FORECAST AREA LATE THIS AFTERNOON THROUGH THE
EVENING. FOCUS FOR THE HEAVIEST RAINS REMAINS ACROSS THE SOUTHERN
HALF OF THE FORECAST AREA BETWEEN 00-06Z AS STRONGER LOW LEVEL
CONVERGENCE ALIGNS ALONG THE 850MB BAROCLINIC ZONE AND AREA OF
ENHANCED ISENTROPIC LIFT. A LOW LEVEL JET OVER THE TENNESSEE VALLEY
WILL TRANSPORT DEEPER MOISTURE UP INTO THE REGION AS WELL. APPROACH
OF THE UPPER WAVE WILL PROMOTE DIFFLUENCE ALOFT...FURTHER ASSISTING
LIFT FOR EFFICIENT RAINFALL.
THERE IS SOME WEAK ELEVATED INSTABILITY PRESENT...BUT JUST DO NOT
SEE ENOUGH TO JUSTIFY AN ISOLATED THUNDER MENTION TONIGHT. BETTER
THREAT FOR A FEW STORMS WILL EXIST CLOSER TO THE SURFACE LOW TRACK
ALONG THE OHIO RIVER. POTENTIAL EXISTS FOR UP TO 1.5 INCHES ALONG
AND SOUTH OF I-70 BY SATURDAY MORNING. WILL CONTINUE WITH
CATEGORICAL POPS TONIGHT. HEAVIER RAINS WILL BEGIN TO SHIFT EAST
AFTER 06Z...BUT LINGERING MID LEVEL DEFORMATION BAND WILL MAINTAIN
LIGHTER RAIN FOR MUCH OF THE REST OF THE NIGHT. HRRR AND WRF-NMM/ARW
BRING BACK END OF THE RAIN INTO THE NORTHERN WABASH VALLEY AROUND OR
SHORTLY BEFORE DAYBREAK. WINDS WILL PICK UP LATE TONIGHT AS WELL AS
A BRISK NORTHERLY FLOW DEVELOPS BEHIND THE SURFACE LOW.
TEMPS...MOS APPEARS A BIT AGGRESSIVE IN BRINGING THE COLDER AIR IN
PRIOR TO 12Z. GENERALLY TRENDED A DEGREE OR TWO ABOVE MAVMOS
GUIDANCE WITH LOWS RANGING FROM THE MID 30S NORTH TO LOWER 40S
SOUTH.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY/...
ISSUED AT 347 PM EST FRI DEC 5 2014
FORECAST CHALLENGES FOCUS ON THE DEPARTURE OF THE RAIN SATURDAY
MORNING...AND POSSIBILITY FOR LIGHT PRECIP WITH A WEAK SYSTEM ON
MONDAY.
THE UPPER WAVE AND SURFACE LOW WILL CONTINUE TO MOVE AWAY TO THE
EAST WITH LIGHT RAIN ENDING FROM NORTHWEST TO SOUTHEAST DURING THE
MORNING. WRF DATA LOOKS VERY GOOD WITH RESPECT TO TIMING AND WAS
UTILIZED FOR MORNING POPS. EXPECT THE ENTIRE FORECAST AREA WILL BE
FREE OF PRECIP AROUND MIDDAY. DRIER AIR ALOFT WILL QUICKLY ADVECT
INTO THE REGION WITH STRONG HIGH PRESSURE SATURDAY AFTERNOON...BUT
RH PROGS AND MODEL SOUNDINGS INDICATE LINGERING LOW LEVEL MOISTURE
REMAINING TRAPPED BENEATH A SLOWLY WEAKENING INVERSION. EXPECT LOWER
CLOUDS TO LINGER AS A RESULT...WITH FULL CLEARING OF THE CLOUD DECK
NOT COMING UNTIL SATURDAY EVENING AS STRONGER SUBSIDENCE ENABLES
DRIER AIR TO INFILTRATE THE NEAR SURFACE LAYER.
HIGH PRESSURE RIDGE WILL DRIFT SLOWLY THROUGH THE GREAT LAKES
SATURDAY NIGHT AND SUNDAY...PROVIDING A DRY COOL E/NE FLOW ACROSS
CENTRAL INDIANA. EXPECT ABUNDANT SUNSHINE ON SUNDAY...WHICH
AMAZINGLY WOULD BE THE FIRST DAY WITH EXTENDED SUNSHINE AND BLUE
SKIES FOR MANY SINCE NOVEMBER 21.
MID AND HIGH LEVEL CLOUDS WILL INCREASE AGAIN BEGINNING SUNDAY NIGHT
WITH SKIES BECOMING FAIRLY CLOUDY MONDAY AS AN UPPER WAVE AND
ASSOCIATED LOW PRESSURE ASSOCIATED WITH THE NORTHERN JET STREAM
TRACK INTO THE GREAT LAKES. DESPITE INCREASING ISENTROPIC LIFT AND
HINT OF SOME DEVELOPING LOW LEVEL CONVERGENCE...MOISTURE PROFILES
LARGELY LOOK UNIMPRESSIVE AND FOCUSED PRIMARILY ABOVE 10KFT. HAVE A
HARD TIME JUSTIFYING MUCH HIGHER THAN LOW CHANCE POPS AS THE SYSTEM
PASSES THROUGH. ENOUGH COLD AIR PRESENT THAT MAY SEE A MIXTURE OF
LIGHT SNOW AND RAIN IN THE NORTHERN WABASH VALLEY MONDAY MORNING
BEFORE PRECIP TRANSITIONS TO ALL RAIN. REGARDLESS...QPF VALUES AT
THIS POINT LOOK NO HIGHER THAN A FEW HUNDREDTHS.
TEMPS...LEANED CLOSER TO COOLER METMOS FOR SATURDAY HIGHS WITH THE
LINGER LOW CLOUDS. WENT NEAR MOS FOR SUNDAY THEN UNDERCUT FOR MONDAY
AND LEANED CLOSER TO ECMWF ENSEMBLE MEAN TEMPS. DESPITE WARM
ADVECTION AHEAD OF THE SURFACE LOW...MEXMOS LOOKS TOO AGGRESSIVE
WITH WARMING TEMPS. LEANED TOWARDS WARMER METMOS FOR SATURDAY NIGHT
LOWS AND TOOK A MODEL BLEND FOR SUNDAY NIGHT.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 220 AM EST SAT DEC 6 2014
DRY WEATHER IS EXPECTED THIS PERIOD AS THE GFS SHOWS A DEPARTING
TROUGH OF LOW PRESSURE ON TUESDAY AND HIGH PRESSURE OVER THE
PLAINS STATES BEGINNING TO BUILD ACROSS THE AREA FOR THE MIDDLE OF
THE NEXT WORK WEEK.
AS THE SURFACE HIGH PUSHES EAST OF INDIANA ON THURSDAY THE GFS
DEPICTS ABUNDANT MOISTURE ALOFT IN THE RETURN FLOW. MEANWHILE THE
ECMWF IS MUCH LESS AGGRESSIVE. GIVEN THE LACK OF DYNAMICS
ALOFT...HAVE LEANED TOWARD THE DRYER ECMWF SOLUTION FOR NOW.
STRONG RIDGING BUILDS ALOFT AS THE WORK WEEK COMES TO AN END...AS
SOUTHERLY TO SOUTHWEST SURFACE WINDS KEEP COLDER ARCTIC AIR AT
BAY. THUS WILL CONTINUE THROUGH THE PERIOD WITH AT OR ABOVE NORMAL
TEMPERATURES.
&&
.AVIATION /DISCUSSION FOR THE 060900Z IND TAF UPDATE/...
RADAR TRENDS SUGGEST AT LAST THE END OF THE RAIN FALL IS NEAR.
BACK EDGE OF PRECIP APPEARS OVER EAST CENTRAL
INDIANA...PROGRESSING EASTWARD. OBS UPSTREAM STILL SHOW EXTENSIVE
MVFR TO IFR CONDITIONS. THUS BASED UPON LATEST TRENDS...EXPECT ONE
MORE PERIOD OF LIGHT RAIN AT IND AS THE BACK EDGE OF THE PRECIP
WORKS ACROSS THE STATE.
IMPROVEMENT TO VFR STILL APPEARS GRADUAL AND HEATING...MIXING AND
DRIER AIR ARRIVING ON NORTHERLY WINDS BY LATE THIS MORNING.
/DISCUSSION FOR THE 060600Z TAF ISSUANCE/...
ISSUED AT 1030 PM EST FRI DEC 5 2014
IFR AND WORSE CONDITIONS EXPECTED TO BE THE MOST PREVALENT FLIGHT
CATEGORIES THROUGH THE NIGHT.
RADAR TRENDS AND 02Z RAPID REFRESH REFLECTIVITY PROGS SUGGEST THE
RAIN WILL CONTINUE THROUGH THE NIGHT WITH MOSTLY A LIGHT INTENSITY
BEFORE ENDING AFTER 09Z AT LAF...11Z AT HUF...12Z AT IND AND 13Z AT
BMG. SHOULD SEE CONDITIONS IMPROVE TO MVFR AFTER 12Z FROM NORTHWEST
TO SOUTHEAST. DO NOT EXPECT MUCH CLEARING OVERNIGHT SATURDAY
NIGHT...BUT COULD SEE A FEW BREAKS.
WINDS WILL BE BRIEFLY EAST AND NORTHEAST NEAR 10 KNOTS AND THEN
BECOME NORTH AND INCREASE TO NEAR 15 KNOTS OVERNIGHT WITH GUSTS TO
AROUND 20 KNOTS. SPEED AND DIRECTION SHOULD BE SIMILAR DURING THE
DAY AND BECOME NORTHEAST 10 KNOTS OR LESS AFTER 00Z TONIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...RYAN/50
SHORT TERM...RYAN
LONG TERM....PUMA
AVIATION...MK/JP
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
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AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
243 AM EST SAT DEC 6 2014
.UPDATE...
THE LONG TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 347 PM EST FRI DEC 5 2014
WIDESPREAD RAIN WILL CONTINUE THROUGH SATURDAY MORNING AS LOW
PRESSURE TRACKS THROUGH THE OHIO VALLEY. WITH THE EXCEPTION OF A FEW
SHOWERS MONDAY AS LOW PRESSURE PASSES THROUGH THE GREAT LAKES...DRY
AND SEASONABLY COOL WEATHER CAN BE EXPECTED THROUGH MUCH OF NEXT
WEEK.
&&
.NEAR TERM /REST OF TONIGHT/...
ISSUED AT 953 PM EST FRI DEC 5 2014
FORECAST IS IN GOOD SHAPE AND MADE NO MAJOR CHANGES. RAIN WILL
CONTINUE ACROSS THE AREA AS LOW PRESSURE MOVES SOUTH OF CENTRAL
INDIANA AND AN UPPER TROUGH MOVES INTO THE AREA. LATER TONIGHT AS
FORCING SHIFTS EAST...RAIN WILL DIMINISH SOME FROM NORTHWEST TO
SOUTHEAST. WARM AIR WILL REMAIN JUST SOUTH OF THE AREA.
PREVIOUS DISCUSSION FOLLOWS...
RAIN CONTINUES ACROSS THE FORECAST AREA THIS AFTERNOON...AND EXPECT
ONLY TO INCREASE FURTHER IN INTENSITY OVER THE NEXT SEVERAL HOURS
WITH THE APPROACH OF LOW PRESSURE. TEMPS RANGED FROM THE UPPER 30S
NORTH TO UPPER 40S ACROSS FAR SOUTHERN COUNTIES AT 20Z.
A RAW WET NIGHT UPCOMING AS LOW PRESSURE CURRENTLY OVER THE OZARKS
TRACKS E/NE ALONG THE OHIO RIVER TONIGHT. MODEL GUIDANCE IN
EXCELLENT AGREEMENT ON SPREADING ANOTHER WAVE OF HEAVIER CONVECTIVE
RAINFALL INTO THE FORECAST AREA LATE THIS AFTERNOON THROUGH THE
EVENING. FOCUS FOR THE HEAVIEST RAINS REMAINS ACROSS THE SOUTHERN
HALF OF THE FORECAST AREA BETWEEN 00-06Z AS STRONGER LOW LEVEL
CONVERGENCE ALIGNS ALONG THE 850MB BAROCLINIC ZONE AND AREA OF
ENHANCED ISENTROPIC LIFT. A LOW LEVEL JET OVER THE TENNESSEE VALLEY
WILL TRANSPORT DEEPER MOISTURE UP INTO THE REGION AS WELL. APPROACH
OF THE UPPER WAVE WILL PROMOTE DIFFLUENCE ALOFT...FURTHER ASSISTING
LIFT FOR EFFICIENT RAINFALL.
THERE IS SOME WEAK ELEVATED INSTABILITY PRESENT...BUT JUST DO NOT
SEE ENOUGH TO JUSTIFY AN ISOLATED THUNDER MENTION TONIGHT. BETTER
THREAT FOR A FEW STORMS WILL EXIST CLOSER TO THE SURFACE LOW TRACK
ALONG THE OHIO RIVER. POTENTIAL EXISTS FOR UP TO 1.5 INCHES ALONG
AND SOUTH OF I-70 BY SATURDAY MORNING. WILL CONTINUE WITH
CATEGORICAL POPS TONIGHT. HEAVIER RAINS WILL BEGIN TO SHIFT EAST
AFTER 06Z...BUT LINGERING MID LEVEL DEFORMATION BAND WILL MAINTAIN
LIGHTER RAIN FOR MUCH OF THE REST OF THE NIGHT. HRRR AND WRF-NMM/ARW
BRING BACK END OF THE RAIN INTO THE NORTHERN WABASH VALLEY AROUND OR
SHORTLY BEFORE DAYBREAK. WINDS WILL PICK UP LATE TONIGHT AS WELL AS
A BRISK NORTHERLY FLOW DEVELOPS BEHIND THE SURFACE LOW.
TEMPS...MOS APPEARS A BIT AGGRESSIVE IN BRINGING THE COLDER AIR IN
PRIOR TO 12Z. GENERALLY TRENDED A DEGREE OR TWO ABOVE MAVMOS
GUIDANCE WITH LOWS RANGING FROM THE MID 30S NORTH TO LOWER 40S
SOUTH.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY/...
ISSUED AT 347 PM EST FRI DEC 5 2014
FORECAST CHALLENGES FOCUS ON THE DEPARTURE OF THE RAIN SATURDAY
MORNING...AND POSSIBILITY FOR LIGHT PRECIP WITH A WEAK SYSTEM ON
MONDAY.
THE UPPER WAVE AND SURFACE LOW WILL CONTINUE TO MOVE AWAY TO THE
EAST WITH LIGHT RAIN ENDING FROM NORTHWEST TO SOUTHEAST DURING THE
MORNING. WRF DATA LOOKS VERY GOOD WITH RESPECT TO TIMING AND WAS
UTILIZED FOR MORNING POPS. EXPECT THE ENTIRE FORECAST AREA WILL BE
FREE OF PRECIP AROUND MIDDAY. DRIER AIR ALOFT WILL QUICKLY ADVECT
INTO THE REGION WITH STRONG HIGH PRESSURE SATURDAY AFTERNOON...BUT
RH PROGS AND MODEL SOUNDINGS INDICATE LINGERING LOW LEVEL MOISTURE
REMAINING TRAPPED BENEATH A SLOWLY WEAKENING INVERSION. EXPECT LOWER
CLOUDS TO LINGER AS A RESULT...WITH FULL CLEARING OF THE CLOUD DECK
NOT COMING UNTIL SATURDAY EVENING AS STRONGER SUBSIDENCE ENABLES
DRIER AIR TO INFILTRATE THE NEAR SURFACE LAYER.
HIGH PRESSURE RIDGE WILL DRIFT SLOWLY THROUGH THE GREAT LAKES
SATURDAY NIGHT AND SUNDAY...PROVIDING A DRY COOL E/NE FLOW ACROSS
CENTRAL INDIANA. EXPECT ABUNDANT SUNSHINE ON SUNDAY...WHICH
AMAZINGLY WOULD BE THE FIRST DAY WITH EXTENDED SUNSHINE AND BLUE
SKIES FOR MANY SINCE NOVEMBER 21.
MID AND HIGH LEVEL CLOUDS WILL INCREASE AGAIN BEGINNING SUNDAY NIGHT
WITH SKIES BECOMING FAIRLY CLOUDY MONDAY AS AN UPPER WAVE AND
ASSOCIATED LOW PRESSURE ASSOCIATED WITH THE NORTHERN JET STREAM
TRACK INTO THE GREAT LAKES. DESPITE INCREASING ISENTROPIC LIFT AND
HINT OF SOME DEVELOPING LOW LEVEL CONVERGENCE...MOISTURE PROFILES
LARGELY LOOK UNIMPRESSIVE AND FOCUSED PRIMARILY ABOVE 10KFT. HAVE A
HARD TIME JUSTIFYING MUCH HIGHER THAN LOW CHANCE POPS AS THE SYSTEM
PASSES THROUGH. ENOUGH COLD AIR PRESENT THAT MAY SEE A MIXTURE OF
LIGHT SNOW AND RAIN IN THE NORTHERN WABASH VALLEY MONDAY MORNING
BEFORE PRECIP TRANSITIONS TO ALL RAIN. REGARDLESS...QPF VALUES AT
THIS POINT LOOK NO HIGHER THAN A FEW HUNDREDTHS.
TEMPS...LEANED CLOSER TO COOLER METMOS FOR SATURDAY HIGHS WITH THE
LINGER LOW CLOUDS. WENT NEAR MOS FOR SUNDAY THEN UNDERCUT FOR MONDAY
AND LEANED CLOSER TO ECMWF ENSEMBLE MEAN TEMPS. DESPITE WARM
ADVECTION AHEAD OF THE SURFACE LOW...MEXMOS LOOKS TOO AGGRESSIVE
WITH WARMING TEMPS. LEANED TOWARDS WARMER METMOS FOR SATURDAY NIGHT
LOWS AND TOOK A MODEL BLEND FOR SUNDAY NIGHT.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 220 AM EST SAT DEC 6 2014
DRY WEATHER IS EXPECTED THIS PERIOD AS THE GFS SHOWS A DEPARTING
TROUGH OF LOW PRESSURE ON TUESDAY AND HIGH PRESSURE OVER THE
PLAINS STATES BEGINNING TO BUILD ACROSS THE AREA FOR THE MIDDLE OF
THE NEXT WORK WEEK.
AS THE SURFACE HIGH PUSHES EAST OF INDIANA ON THURSDAY THE GFS
DEPICTS ABUNDANT MOISTURE ALOFT IN THE RETURN FLOW. MEANWHILE THE
ECMWF IS MUCH LESS AGGRESSIVE. GIVEN THE LACK OF DYNAMICS
ALOFT...HAVE LEANED TOWARD THE DRYER ECMWF SOLUTION FOR NOW.
STRONG RIDGING BUILDS ALOFT AS THE WORK WEEK COMES TO AN END...AS
SOUTHERLY TO SOUTHWEST SURFACE WINDS KEEP COLDER ARCTIC AIR AT
BAY. THUS WILL CONTINUE THROUGH THE PERIOD WITH AT OR ABOVE NORMAL
TEMPERATURES.
&&
.AVIATION /DISCUSSION FOR THE 060600Z TAF ISSUANCE/...
ISSUED AT 1030 PM EST FRI DEC 5 2014
IFR AND WORSE CONDITIONS EXPECTED TO BE THE MOST PREVALENT FLIGHT
CATEGORIES THROUGH THE NIGHT.
RADAR TRENDS AND 02Z RAPID REFRESH REFLECTIVITY PROGS SUGGEST THE
RAIN WILL CONTINUE THROUGH THE NIGHT WITH MOSTLY A LIGHT INTENSITY
BEFORE ENDING AFTER 09Z AT LAF...11Z AT HUF...12Z AT IND AND 13Z AT
BMG. SHOULD SEE CONDITIONS IMPROVE TO MVFR AFTER 12Z FROM NORTHWEST
TO SOUTHEAST. DO NOT EXPECT MUCH CLEARING OVERNIGHT SATURDAY
NIGHT...BUT COULD SEE A FEW BREAKS.
WINDS WILL BE BRIEFLY EAST AND NORTHEAST NEAR 10 KNOTS AND THEN
BECOME NORTH AND INCREASE TO NEAR 15 KNOTS OVERNIGHT WITH GUSTS TO
AROUND 20 KNOTS. SPEED AND DIRECTION SHOULD BE SIMILAR DURING THE
DAY AND BECOME NORTHEAST 10 KNOTS OR LESS AFTER 00Z TONIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...RYAN/50
SHORT TERM...RYAN
LONG TERM....PUMA
AVIATION...MK
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
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AREA FORECAST DISCUSSION...UPDATED
NWS QUAD CITIES IA IL
1141 AM CST SAT DEC 6 2014
.UPDATE...
ISSUED AT 1042 AM CST SAT DEC 6 2014
CURRENT SATELLITE SHOWS THE EXTENT OF THE CLOUD COVER FROM
PELLA...JUST SOUTH OF IOWA CITY TO PRINCETON. THIS CLOUD DECK HAD
SLOWED DOWN EARLIER WITH NE WINDS OFF THE LAKE. IN THE LAST COUPLE
OF HOURS THE CLEARING BEGAN TO INCREASE AND THE CLOUD DECK MOVED
SOUTH. HAD TO UPDATE THE CLOUD FORECAST TO TIME THE CURRENT DECK
BETTER. TIMING TOOL SUGGESTS SOUTHERN CWA WILL NOT CLEAR UNTIL MID
AFTERNOON. AS A RESULT TEMPS WILL BE WARMER IN THE NORTH THAN THE
SOUTH THIS AFTERNOON BY A COUPLE OF DEGREES. LOADED THE RUC HIGH
TEMPS AND THEN ADJUSTED CERTAIN SITES DOWN OR UP TO REPRESENT THE
CLOUD DECK ACROSS THE AREA. OTHERWISE...THE REST OF THE FORECAST
LOOKS GOOD.
UPDATE ISSUED AT 413 AM CST SAT DEC 6 2014
ADDED PATCHY DENSE FOG IN THE RIVER VALLEYS ACROSS THE NORTHERN
CWA. CLEARING HAS ALREADY ENTERED INTO NORTHERN IOWA AND CONTINUES
TO PUSH SOUTHWARD. FURTHER UPSTREAM...AREAS OF DENSE RADIATION FOG
HAVE DEVELOPED IN SOUTHERN MINNESOTA WITH SOME REPORTED
VISIBILITIES DOWN TO 1/4 SM. AGAIN...ANY DENSE FOG THAT DEVELOPS
OVER THE NEXT SEVERAL HOURS SHOULD BE FOCUSED IN LOW-LYING AREAS.
ALSO UPDATED SKY COVER THROUGH THE DAY WITH A FASTER NORTH TO
SOUTH BREAK UP OF THE STRATUS.
&&
.SYNOPSIS...
ISSUED AT 323 AM CST SAT DEC 6 2014
OVERVIEW...MID AND UPPER LEVEL FLOW BECOMES NORTHWESTERLY TODAY WITH
THE MIDWEST IN BETWEEN A SHORTWAVE TROUGH OVER BOTH THE EAST AND
WEST COASTS. 850 MB RIDGE AXIS WILL POSITION RIGHT ACROSS THE UPPER
MISSISSIPPI VALLEY REGION INTO SUNDAY MORNING. NO PRECIPITATION IS
FORECAST DURING THIS TIME AS THE NORTHWEST FLOW AND LARGE SCALE
SUBSIDENCE CONTINUE TO DRY OUT THE COLUMN.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 323 AM CST SAT DEC 6 2014
TODAY...CHALLENGE FOR TODAY WILL BE THE EXTENT AND PERSISTENCE OF
VERY LOW STRATUS CLOUDS. CURRENTLY...SFC OBSERVING STATIONS IN THE
DVN CWA ARE REPORTING CEILINGS BETWEEN 300-600 FT AGL WITH NO SIGNS
OF IMPROVEMENT SO FAR THROUGH THIS EVENING/OVERNIGHT. 11-3.9 MICRON
IR FOG PRODUCT DEPICTS THE CLEARING LINE TO NOW BE SOUTH OF KLSE
WITH A SLOW BUT STEADY SOUTHWARD PROGRESSION.
NAM/RAP FORECAST A VERY DRY COLUMN THROUGH THE DAY WITH THE
EXCEPTION OF A RESIDUAL MOIST LAYER THAT BECOMES TRAPPED AT AROUND
950-975 MB BENEATH A LARGE-SCALE SUBSIDENCE INVERSION. SOUNDINGS ARE
MORE SATURATED AT DAVENPORT AND POINTS SOUTHWARD AND LESS TO THE
N/NW. BEST CHANCES FOR CLEARING ARE N OF QUAD CITIES DURING THE
MORNING...THEN ALL BUT THE FAR SOUTHERN PORTION OF THE FORECAST AREA
DURING THE AFTN. NOT MUCH VARIATION IN SFC TEMPS TODAY WITH A SPREAD
OF ONLY MID TO UPPER 30S.
TONIGHT...LOW-LEVEL STRATUS SHOULD GET SCOURED OUT FOR MOST PLACES
BUT ANY CLEARING WILL BE BRIEF AS MID-LEVEL CLOUDS BEGIN TO STREAM
IN FROM THE SW AHEAD OF THE NEXT SHORTWAVE TROUGH SHIFTING EAST OF
THE ROCKIES. WEAK 1000-500 MB POSITIVE THICKNESS ADVECTION WILL
ENSUE AFTER 06Z/SUNDAY AS MID-LEVEL WINDS BACK FROM NW TO SW. LOWS
IN MID 20S WILL BE A FEW DEGREES ABOVE AVG.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 323 AM CST SAT DEC 6 2014
EARLY CHALLENGE IS THE SYSTEM MOVING INTO THE PACIFIC NW THAT WILL
BRING A GOOD POTENTIAL FOR LIGHT PRECIPITATION...POSSIBLY IN THE
FORM OF A WINTRY MIX...OVER THE AREA SUNDAY NIGHT INTO MONDAY
MORNING. DRY AND NEAR TO BELOW NORMAL TEMPERATURES WILL FOLLOW TUE
AND WED WITH PASSING HIGH PRESSURE. MODEL RUNS OVER THE PAST 24
HOURS HAVE TRENDED TOWARD A MORE AMPLIFIED UPPER LEVEL FLOW NEXT
WEEK RESULTING FROM A DEEPER UPPER LOW NOW DEPICTED OVER THE MID
ATLANTIC COAST AND THE NE U.S. LATE WED THROUGH FRI. THIS
SUGGESTS A LOWER CONFIDENCE LATE WEEK PERIOD WITH EVEN A POTENTIAL
FOR AT LEAST LIGHT PRECIPITATION AS THIS BLOCKING LOW MAY DELAY
THE EASTWARD PROGRESSION OF THE WESTERN U.S. UPPER RIDGE AND KEEP
A MORE ACTIVE...N-NW UPPER LEVEL FLOW IN PLACE OVERHEAD LATER INTO
THE WEEK.
SUNDAY THROUGH MONDAY...THE UPPER LEVEL SYSTEM OFF THE NW COAST IS
EXPECTED TO STRENGTHEN AND THEN PHASE WITH NORTHERN STREAM
ENERGY...DIGGING A LONGWAVE TROUGH OVER THE EASTERN U.S. TOWARD
MID WEEK. AS IT PASSES TO THE NORTH LATE SUNDAY NIGHT...IT
SENDS A ROUND OF MID LEVEL QG FORCING OVER THE FORECAST AREA ABOVE
LOW LEVEL WARM ADVECTION AND MODEST MOISTURE RETURN. TOP DOWN
APPROACH FROM FORECAST SOUNDINGS SUGGESTS A POSSIBLE RAIN/SNOW/SLEET
MIX ACROSS THE NORTHERN HALF OF THE FORECAST AREA...WITH RAIN/SNOW
CENTRAL AND MAINLY RAIN SOUTH...WHICH MAY CHANGE TO PRIMARILY RAIN
OVER ALL BUT THE FAR NORTHEAST WITH WARMING LOW LEVELS TOWARD
MORNING. CONFIDENCE REMAINS LOW IN THE MODEL DEPICTION OF
CRITICAL LOW LEVEL THERMAL PROFILES AND FURTHER ADJUSTMENTS TO
PRECIPITATION TYPES WILL LIKELY BE NEEDED. WITH THE SURFACE LOW
TRACKING WELL TO THE NORTH AND MODEST LIFT...QPF FOR THE EVENT
SHOULD BE LESS THAN A TENTH OF AN INCH WITH LITTLE IF ANY
ACCUMULATION OF SLEET OR SNOW NORTH. WITH THE SYSTEM SLOWING
SOME...HAVE EXTENDED POPS INTO MONDAY MORNING OVER THE EAST FOR
WHAT WOULD LIKELY BE RAIN OR RAIN/SNOW MIX. TEMPERATURES MAY
REACH INTO THE MID 40S IN THE SOUTH BEFORE THE COLD FRONT PUSHES
THROUGH IN THE AFTERNOON.
TUESDAY THROUGH TUE NIGHT...PASSING HIGH PRESSURE RIDGE WILL LIMIT
HIGHS TO THE 30S WITH OVERNIGHT LOWS IN THE UPPER TEENS TO LOWER
20S.
WEDNESDAY THROUGH FRIDAY...THE 00Z GFS...GEM AND ECMWF OFFER VARYING
SOLUTIONS WITH THE TIMING AND TRACK OF THE NEXT SHORTWAVE IN THE NW
FLOW AROUND MID WEEK...AND HOW FAST THE LARGE UPPER LOW EXITS THE
NORTHEAST. THE GFS AND GEM ARE IN ONE CAMP WITH LIGHT PRECIPITATION
DEVELOPING WITH THE NEXT SHORTWAVE IN THE NW FLOW AND ALONG A WARM
FRONT WED INTO WED NIGHT OVER ESPECIALLY THE SOUTH...THEN OVER THE
ENTIRE AREA WED NIGHT...WHEREAS THE ECMWF IS DRY WITH A SURFACE
RIDGE IN PLACE. RESULTING MODEL CONSENSUS BLENDS OF QPF AND POP FIELDS
SUGGESTED SEVERAL PERIODS OF LIGHT PRECIPITATION FROM WED THROUGH
FRI. WITH LOW CONFIDENCE IN THESE PERIODS DUE TO THE POOR
CONSISTENCY AND LACK OF AGREEMENT...HAVE KEPT ONLY SLIGHT CHANCES
FOR WHAT WOULD LIKELY BE LIGHT RAIN CONFINED TO ONLY WED NIGHT.
TEMPERATURES SHOULD STILL MODERATE WITH HIGHS BACK INTO THE 40S
THU AND FRI OVER ESPECIALLY THE SOUTH...BUT THE WELL ADVERTISED
TRANSITION TO MUCH ABOVE NORMAL TEMPERATURES MAY BE DELAYED TO
NEXT WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1132 AM CST SAT DEC 6 2014
MAIN CONCERN FOR AVIATION IN THE SHORT TERM ARE THE IFR CLOUD DECK
MOVING OUT OF THE AREA. THE ONLY TAF SITE AFFECTED BY THIS IS BRL
AND SHOULD SEE THE DECK OUT BY 2100Z AT THE LATEST. ONCE THE DECK
MOVES OUT VFR CONDITIONS WILL PERSIST DURING THE PERIOD. THE NAM
APPEARS TO HAVE PROBLEMS WITH BOUNDARY LAYER MOISTURE AGAIN AND
SUGGESTS THAT LOW CLOUDS WILL AFFECT THE TAF SITES TONIGHT. THAT
DOES NOT LOOK LIKELY AT ALL...SO DID NOT USE THE NAM DUE TO MODEL
ISSUES.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...GIBBS
SYNOPSIS...UTTECH
SHORT TERM...UTTECH
LONG TERM...SHEETS
AVIATION...GIBBS
AREA FORECAST DISCUSSION...UPDATED
NWS QUAD CITIES IA IL
1048 AM CST SAT DEC 6 2014
.UPDATE...
ISSUED AT 1042 AM CST SAT DEC 6 2014
CURRENT SATELLITE SHOWS THE EXTENT OF THE CLOUD COVER FROM
PELLA...JUST SOUTH OF IOWA CITY TO PRINCETON. THIS CLOUD DECK HAD
SLOWED DOWN EARLIER WITH NE WINDS OFF THE LAKE. IN THE LAST COUPLE
OF HOURS THE CLEARING BEGAN TO INCREASE AND THE CLOUD DECK MOVED
SOUTH. HAD TO UPDATE THE CLOUD FORECAST TO TIME THE CURRENT DECK
BETTER. TIMING TOOL SUGGESTS SOUTHERN CWA WILL NOT CLEAR UNTIL MID
AFTERNOON. AS A RESULT TEMPS WILL BE WARMER IN THE NORTH THAN THE
SOUTH THIS AFTERNOON BY A COUPLE OF DEGREES. LOADED THE RUC HIGH
TEMPS AND THEN ADJUSTED CERTAIN SITES DOWN OR UP TO REPRESENT THE
CLOUD DECK ACROSS THE AREA. OTHERWISE...THE REST OF THE FORECAST
LOOKS GOOD.
UPDATE ISSUED AT 413 AM CST SAT DEC 6 2014
ADDED PATCHY DENSE FOG IN THE RIVER VALLEYS ACROSS THE NORTHERN
CWA. CLEARING HAS ALREADY ENTERED INTO NORTHERN IOWA AND CONTINUES
TO PUSH SOUTHWARD. FURTHER UPSTREAM...AREAS OF DENSE RADIATION FOG
HAVE DEVELOPED IN SOUTHERN MINNESOTA WITH SOME REPORTED
VISIBILITIES DOWN TO 1/4 SM. AGAIN...ANY DENSE FOG THAT DEVELOPS
OVER THE NEXT SEVERAL HOURS SHOULD BE FOCUSED IN LOW-LYING AREAS.
ALSO UPDATED SKY COVER THROUGH THE DAY WITH A FASTER NORTH TO
SOUTH BREAK UP OF THE STRATUS.
&&
.SYNOPSIS...
ISSUED AT 323 AM CST SAT DEC 6 2014
OVERVIEW...MID AND UPPER LEVEL FLOW BECOMES NORTHWESTERLY TODAY WITH
THE MIDWEST IN BETWEEN A SHORTWAVE TROUGH OVER BOTH THE EAST AND
WEST COASTS. 850 MB RIDGE AXIS WILL POSITION RIGHT ACROSS THE UPPER
MISSISSIPPI VALLEY REGION INTO SUNDAY MORNING. NO PRECIPITATION IS
FORECAST DURING THIS TIME AS THE NORTHWEST FLOW AND LARGE SCALE
SUBSIDENCE CONTINUE TO DRY OUT THE COLUMN.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 323 AM CST SAT DEC 6 2014
TODAY...CHALLENGE FOR TODAY WILL BE THE EXTENT AND PERSISTENCE OF
VERY LOW STRATUS CLOUDS. CURRENTLY...SFC OBSERVING STATIONS IN THE
DVN CWA ARE REPORTING CEILINGS BETWEEN 300-600 FT AGL WITH NO SIGNS
OF IMPROVEMENT SO FAR THROUGH THIS EVENING/OVERNIGHT. 11-3.9 MICRON
IR FOG PRODUCT DEPICTS THE CLEARING LINE TO NOW BE SOUTH OF KLSE
WITH A SLOW BUT STEADY SOUTHWARD PROGRESSION.
NAM/RAP FORECAST A VERY DRY COLUMN THROUGH THE DAY WITH THE
EXCEPTION OF A RESIDUAL MOIST LAYER THAT BECOMES TRAPPED AT AROUND
950-975 MB BENEATH A LARGE-SCALE SUBSIDENCE INVERSION. SOUNDINGS ARE
MORE SATURATED AT DAVENPORT AND POINTS SOUTHWARD AND LESS TO THE
N/NW. BEST CHANCES FOR CLEARING ARE N OF QUAD CITIES DURING THE
MORNING...THEN ALL BUT THE FAR SOUTHERN PORTION OF THE FORECAST AREA
DURING THE AFTN. NOT MUCH VARIATION IN SFC TEMPS TODAY WITH A SPREAD
OF ONLY MID TO UPPER 30S.
TONIGHT...LOW-LEVEL STRATUS SHOULD GET SCOURED OUT FOR MOST PLACES
BUT ANY CLEARING WILL BE BRIEF AS MID-LEVEL CLOUDS BEGIN TO STREAM
IN FROM THE SW AHEAD OF THE NEXT SHORTWAVE TROUGH SHIFTING EAST OF
THE ROCKIES. WEAK 1000-500 MB POSITIVE THICKNESS ADVECTION WILL
ENSUE AFTER 06Z/SUNDAY AS MID-LEVEL WINDS BACK FROM NW TO SW. LOWS
IN MID 20S WILL BE A FEW DEGREES ABOVE AVG.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 323 AM CST SAT DEC 6 2014
EARLY CHALLENGE IS THE SYSTEM MOVING INTO THE PACIFIC NW THAT WILL
BRING A GOOD POTENTIAL FOR LIGHT PRECIPITATION...POSSIBLY IN THE
FORM OF A WINTRY MIX...OVER THE AREA SUNDAY NIGHT INTO MONDAY
MORNING. DRY AND NEAR TO BELOW NORMAL TEMPERATURES WILL FOLLOW TUE
AND WED WITH PASSING HIGH PRESSURE. MODEL RUNS OVER THE PAST 24
HOURS HAVE TRENDED TOWARD A MORE AMPLIFIED UPPER LEVEL FLOW NEXT
WEEK RESULTING FROM A DEEPER UPPER LOW NOW DEPICTED OVER THE MID
ATLANTIC COAST AND THE NE U.S. LATE WED THROUGH FRI. THIS
SUGGESTS A LOWER CONFIDENCE LATE WEEK PERIOD WITH EVEN A POTENTIAL
FOR AT LEAST LIGHT PRECIPITATION AS THIS BLOCKING LOW MAY DELAY
THE EASTWARD PROGRESSION OF THE WESTERN U.S. UPPER RIDGE AND KEEP
A MORE ACTIVE...N-NW UPPER LEVEL FLOW IN PLACE OVERHEAD LATER INTO
THE WEEK.
SUNDAY THROUGH MONDAY...THE UPPER LEVEL SYSTEM OFF THE NW COAST IS
EXPECTED TO STRENGTHEN AND THEN PHASE WITH NORTHERN STREAM
ENERGY...DIGGING A LONGWAVE TROUGH OVER THE EASTERN U.S. TOWARD
MID WEEK. AS IT PASSES TO THE NORTH LATE SUNDAY NIGHT...IT
SENDS A ROUND OF MID LEVEL QG FORCING OVER THE FORECAST AREA ABOVE
LOW LEVEL WARM ADVECTION AND MODEST MOISTURE RETURN. TOP DOWN
APPROACH FROM FORECAST SOUNDINGS SUGGESTS A POSSIBLE RAIN/SNOW/SLEET
MIX ACROSS THE NORTHERN HALF OF THE FORECAST AREA...WITH RAIN/SNOW
CENTRAL AND MAINLY RAIN SOUTH...WHICH MAY CHANGE TO PRIMARILY RAIN
OVER ALL BUT THE FAR NORTHEAST WITH WARMING LOW LEVELS TOWARD
MORNING. CONFIDENCE REMAINS LOW IN THE MODEL DEPICTION OF
CRITICAL LOW LEVEL THERMAL PROFILES AND FURTHER ADJUSTMENTS TO
PRECIPITATION TYPES WILL LIKELY BE NEEDED. WITH THE SURFACE LOW
TRACKING WELL TO THE NORTH AND MODEST LIFT...QPF FOR THE EVENT
SHOULD BE LESS THAN A TENTH OF AN INCH WITH LITTLE IF ANY
ACCUMULATION OF SLEET OR SNOW NORTH. WITH THE SYSTEM SLOWING
SOME...HAVE EXTENDED POPS INTO MONDAY MORNING OVER THE EAST FOR
WHAT WOULD LIKELY BE RAIN OR RAIN/SNOW MIX. TEMPERATURES MAY
REACH INTO THE MID 40S IN THE SOUTH BEFORE THE COLD FRONT PUSHES
THROUGH IN THE AFTERNOON.
TUESDAY THROUGH TUE NIGHT...PASSING HIGH PRESSURE RIDGE WILL LIMIT
HIGHS TO THE 30S WITH OVERNIGHT LOWS IN THE UPPER TEENS TO LOWER
20S.
WEDNESDAY THROUGH FRIDAY...THE 00Z GFS...GEM AND ECMWF OFFER VARYING
SOLUTIONS WITH THE TIMING AND TRACK OF THE NEXT SHORTWAVE IN THE NW
FLOW AROUND MID WEEK...AND HOW FAST THE LARGE UPPER LOW EXITS THE
NORTHEAST. THE GFS AND GEM ARE IN ONE CAMP WITH LIGHT PRECIPITATION
DEVELOPING WITH THE NEXT SHORTWAVE IN THE NW FLOW AND ALONG A WARM
FRONT WED INTO WED NIGHT OVER ESPECIALLY THE SOUTH...THEN OVER THE
ENTIRE AREA WED NIGHT...WHEREAS THE ECMWF IS DRY WITH A SURFACE
RIDGE IN PLACE. RESULTING MODEL CONSENSUS BLENDS OF QPF AND POP FIELDS
SUGGESTED SEVERAL PERIODS OF LIGHT PRECIPITATION FROM WED THROUGH
FRI. WITH LOW CONFIDENCE IN THESE PERIODS DUE TO THE POOR
CONSISTENCY AND LACK OF AGREEMENT...HAVE KEPT ONLY SLIGHT CHANCES
FOR WHAT WOULD LIKELY BE LIGHT RAIN CONFINED TO ONLY WED NIGHT.
TEMPERATURES SHOULD STILL MODERATE WITH HIGHS BACK INTO THE 40S
THU AND FRI OVER ESPECIALLY THE SOUTH...BUT THE WELL ADVERTISED
TRANSITION TO MUCH ABOVE NORMAL TEMPERATURES MAY BE DELAYED TO
NEXT WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 545 AM CST SAT DEC 6 2014
PATCHY DENSE RADIATION FOG MAY DEVELOP AT KCID AND KDBQ PRIOR TO
15Z TODAY AS STRATUS DECK BEGINS TO BREAK APART AND TEMPS FALL.
CONDITIONS WILL THEN SLOWLY IMPROVE THROUGH THIS MORNING FROM
NORTH TO SOUTH. BY MIDDAY...VFR IS ANTICIPATED AT ALL TERMINALS
EXCEPT KBRL WHERE PERIODS OF IFR/LIFR WILL LIKELY CONTINUE. A
STRONG SUBSIDENCE INVERSION WILL MAKE IT DIFFICULT TO MIX OUT
MOISTURE TRAPPED AROUND 950 MB OR BELOW 1 KFT AGL.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...GIBBS
SYNOPSIS...UTTECH
SHORT TERM...UTTECH
LONG TERM...SHEETS
AVIATION...UTTECH
AREA FORECAST DISCUSSION
NWS GOODLAND KS
710 PM MST SUN DEC 7 2014
.UPDATE...
ISSUED AT 705 PM MST SUN DEC 7 2014
ADDED PATCHY FOG TO NORTON/GRAHAM COUNTIES THROUGH MIDNIGHT PER
RUC BOUNDARY LAYER RH AND CURRENT NORTON OBSERVATION WHICH IS
REPORTING 5SM IN MIST. AFTER MIDNIGHT 00Z NAM/RUC/HRRR PUSH THE
HIGHER BOUNDARY LAYER RH OUT OF THE FORECAST AREA. ALSO TWEAKED
SKY COVER A BIT TO TRY AND REFLECT APPROACHING THIN LAYER OF
CIRRUS INTO THE AREA LATER TONIGHT.
&&
.SHORT TERM...(THIS AFTERNOON THROUGH MONDAY)
ISSUED AT 212 PM MST SUN DEC 7 2014
LATEST WV IMAGERY AND RAP ANALYSIS SHOW RIDGING BUILDING ACROSS
WESTERN US...WITH TROUGH CENTERED OVER NORTH DAKOTA AND ITS AXIS
EXTENDING ACROSS EASTERN NE/KS INTO THE SOUTHERN PLAINS. AT THE
SURFACE LOW PRESSURE HAS BUILD ACROSS NORTHERN COLORADO WITH A
WEAK SURFACE TROUGH OVER OUR CWA. STRATUS FOG HAS ERODED AND
CLEAR SKIES/DOWNSLOPE FLOW HAS LED TO TEMPS WARMING INTO THE
MIDDLE 60S ACROSS NW KANSAS AND PARTS OF NORTHEAST COLORADO.
SHORTWAVE RIDGE WILL TRANSITION OVER THE CWA TONIGHT AND MONDAY
WITH DRY CONDITIONS AND MILD TEMPS PERSISTING. THERE IS A WEAK
SHORTWAVE THAT MIGHT BRING SLIGHTLY COOLER TEMPS ALOFT AND HIGH
CLOUD COVER MONDAY AFTERNOON...OTHERWISE WE SHOULD SEE LITTLE
CHANGE IN SENSIBLE WEATHER OVER CWA. GOOD RADIATIONAL CONDITIONS
SHOULD BE IN PLACE AND DEPENDING ON HOW LOW THE TD VALUES WILL
DROP WE COULD SEE OVERNIGHT LOWS IN THE UPPER TEENS TO LOWER 20S.
MET GUIDANCE WAS HINTING AT LIGHT FOG DEVELOPMENT...HOWEVER ALL
OTHER 2M AND STATISTICAL GUIDANCE IS NOT SHOWING THIS...AND WITH
DRY AIR ADVECTING FROM THE WEST TO SOUTHWEST I DECIDED AGAINST FOG
MENTION. DESPITE SLIGHTLY COOLER TEMPS ALOFT MONDAY...THE TREND
HAS BEEN FOR MOST GUIDANCE TO HAVE A COOL BIAS WITH GOOD WARMING
OVER THE LAST FEW DAYS. CONSIDERING THESE BIASES I WOULD STILL
EXPECT DAYTIME HIGHS MONDAY TO BE AROUND 60 FOR MOST OF THE
CWA...WHICH IS A LITTLE LOWER THAN WHAT WE SAW TODAY.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 212 PM MST SUN DEC 7 2014
FOR THE EXTENDED PERIOD...BROAD H5 RIDGE WILL BE IN PLACE OVER THE
WESTERN HALF OF THE COUNTRY FOR MUCH OF THE UPCOMING WEEK. BY THE
TIME GOING INTO THE UPCOMING WEEKEND THOUGH...MODELS DO SHIFT THIS
RIDGE MORE EASTWARD AS A TROUGH APPROACHES THE WEST COAST...INTO THE
ROCKIES ON SATURDAY AND THEN OUT OVER THE CENTRAL/SOUTHERN PLAINS BY
NEXT SUNDAY AS A CUTOFF UPPER LOW. THE LATEST GFS/ECMWF RUNS DO
DIFFER ON TRACK AND PLACEMENT OF THIS SYSTEM AND WILL AFFECT
PRECIPITATION POTENTIAL FOR THE FORECAST AREA.
WITH THE LARGE AREA OF HIGH PRESSURE EXPECTED FOR MUCH OF THE
WEEK...THE CWA WILL BE LOOKING AT HIGH TEMPS 10-15 DEGREES ABOVE
NORMAL AND OVERNIGHT LOWS 5-10 DEGREES ABOVE NORMAL. 925MB TEMPS
RANGING FROM +10C TO +15C THRU THE WEEK BEFORE THE TROUGH ARRIVES
SATURDAY NIGHT/SUNDAY...THE AREA WILL SEE HIGHS 55-60F AND OVERNIGHT
LOWS IN THE MID 20S TO LOW 30S.
PRECIPITATION CHANCES FOR THE UPCOMING WEEK WILL BE NEAR ZERO AS A
RESULT OF HIGH PRESSURE OVER THE AREA. THERE IS A WEAK 700 MB
SHORTWAVE MOVING OFF THE ROCKIES TUESDAY NIGHT INTO WEDNESDAY THAT
TRAVERSES THE REGION. MODERATE 1000-500MB RH VALUES WILL ACCOMPANY
THE PASSAGE OF THIS TROUGH...BUT WITH SURFACE HIGH PRESSURE OVER
AREA...LOW LEVEL AIRMASS WILL BE TOO DRY SO HAVE CONTINUED PREVIOUS
FORECAST THINKING OF JUST MID LEVEL CLOUD COVER WITH THIS ONLY. THE
ONLY CHANCE WILL BE OVER THE UPCOMING WEEKEND WITH THE PASSAGE OF
THE UPPER LOW/TROUGH. LATEST GFS HAS THIS SYSTEM COMING OVER THE
AREA OFF THE ROCKIES...WHILE THE ECMWF HAS THIS SYSTEM DROPPING
OVER TEXAS. THIS WILL ALLOW FOR SYSTEM TO GRAB AMPLE MOISTURE TO
PRODUCE SOME PRECIP...WHILE THE GFS IS ALMOST DRY. WHILE THE BULK OF
THE ECMWF SCENARIO WILL REMAIN SOUTH OF THE CWA...STILL THINK SOME
OF THIS WILL IMPACT THE CWA SO HAVE KEPT IN UP TO CHANCE POPS FOR
LIGHT RAIN/SNOW. LOOKING FOR ANY LIGHT SNOW AT NIGHT SATURDAY INTO
SUNDAY MORNING...AND ANY LIGHT RAIN DURING THE DAY. THE CWA AFFECTED
WITH ANY OVERNIGHT LIGHT SNOW SHOULD BE LIGHT ON THE ORDER OF A
COUPLE TENTHS RIGHT NOW.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 400 PM MST SUN DEC 7 2014
FOR KGLD AND KMCK...VFR THROUGH THE PERIOD. LIGHT NORTHWEST WINDS
AT TAF ISSUANCE FORECAST TO BACK TO THE WEST AROUND 08Z THEN
SOUTHWEST AROUND 19Z...SPEEDS UNDER 10KTS. BY 23Z LIGHT/VARIABLE
WINDS EXPECTED. FAIR WEATHER CU POSSIBLE AFTER 19Z MONDAY
OTHERWISE SOME SLIGHT INCREASE IN HIGH CLOUDS MOVING IN FROM THE
NORTHWEST.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...99
SHORT TERM...DR
LONG TERM...JN
AVIATION...99
AREA FORECAST DISCUSSION
NWS GOODLAND KS
400 PM MST SAT DEC 6 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 207 PM MST SAT DEC 6 2014
EARLY AFTERNOON WV IMAGERY AND RAP H5 ANALYSIS SHOW PROGRESSIVE
TROUGH-RIDGE TROUGH PATTERN ACROSS US WITH RIDGE CURRENTLY
EXTENDING FROM SOUTH CENTRAL CANADA ACROSS THE CENTRAL PLAINS. SW
FLOW IS IN PLACE FROM THE FOUR CORNERS REGION AND INTO WESTERN KS
WITH SHORTWAVE TROUGH MOVING OUT OF THE GREAT BASIN TOWARDS THE
CENTRAL ROCKIES. AT THE SURFACE LEE TROUGH IS IN PLACE OVER
EASTERN COLORADO WITH SOUTHERLY FLOW ACROSS OUR CWA.
AS SHORTWAVE TROUGH TRANSITIONS EASTWARD STATIONARY
FRONT/BAROCLINIC ZONE WITH SHIFT NORTH AND EAST ALLOWING FOR
SOUTHEAST MOISTURE RETURN INTO THE EASTERN HALF OF OUR CWA.
MIDLEVEL MOISTURE/UPPER LEVEL FORCING COULD ALLOW FOR A BRIEF
PERIOD OF LIGHT RAIN SHOWERS LATE TONIGHT...HOWEVER MODEL
SOUNDINGS INDICATE A SIGNIFICANT DRY LAYER WOULD LIKELY PREVENT
ANY ELEVATED PRECIPITATION FROM REACHING THE SURFACE.
MAIN CONCERN WILL BE POTENTIAL FOR DENSE FOG DEVELOPMENT AND
POTENTIAL FOR DRIZZLE ACROSS EASTERN CWA LATE TONIGHT THROUGH
SUNDAY MORNING. NAM/RAP SHOW WEAK SURFACE CONVERGENCE IN PROXIMITY
OF BAROCLINIC ZONE WHICH COULD PROVIDE ENOUGH LIFT WITHIN SHALLOW
SATURATED LAYER TO ALLOW FOR DRIZZLE DEVELOPMENT. THIS COULD BE
MORE OF A STRATUS/DRIZZLE EVENT...THOUGH CONSIDERING THE GOOD
MOISTURE RETURN LOWER VISIBILITIES ARE CERTAINLY POSSIBLE. HIGH
CLOUDS HAVE ALREADY BEEN HAVING AN IMPACT ON MIXING THIS
AFTERNOON...AND WITH THICKENING/LOWERING CLOUDS THOUGH THE NIGHT
(ALONG WITH TD VALUES INCREASING TO MID/UPPER 30S IN THE
EAST)...RADIATIONAL COOLING WILL BE LIMITED. NOT ONLY COULD THIS
LIMIT DENSE FOG DEVELOPMENT...BUT THIS MAKES FREEZING
FOG/FREEZING DRIZZLE UNLIKELY AT THIS POINT. AT THIS POINT HOLDING
OFF ON HIGHLIGHTS SEEMS THE BEST COURSE.
WITH SHIFT BACK TO SW FLOW AS SHORTWAVE RIDGING BUILDS BACK INTO
THE ROCKIES THERE SHOULD BE RAPID IMPROVEMENT IN CONDITIONS
SUNDAY.CLEARING SKIES AND WAA THROUGH THE AFTERNOON SHOULD ALLOW
HIGHS TO WARM TO AROUND 60F...THOUGH STRATUS MAY HOLD ON A LITTLE
LONGER IN OUR EASTERN CWA LIMITING DAYTIME MIXING AND KEEPING
HIGHS IN THE LOW TO MID 50S.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 207 PM MST SAT DEC 6 2014
UPPER FLOW WILL BE NORTHWEST SUNDAY NIGHT AHEAD OF A RIDGE THAT WILL
BUILD INTO THE ROCKIES AND PLAINS MONDAY AND TUESDAY. SURFACE HIGH
PRESSURE WILL RESIDE OVER THE PLAINS THROUGH THIS TIME.
DRY CONDITIONS WILL CONTINUE ACROSS THE FA THROUGH TUESDAY.
SUBSIDENCE AND OR A LACK OF SIGNIFICANT FORCING ALONG WITH A LACK OF
LAYER MEAN RH WILL PROVIDE SUPPORT FOR THE DRY CONDITIONS. POPS
WILL BE NIL FROM SUNDAY NIGHT THROUGH TUESDAY.
MIN TEMPERATURES SHOULD BE IN THE MID AND UPPER 20S SUNDAY AND
MONDAY NIGHTS. MAX TEMPERATURES SHOULD RISE TO THE MID 50S MONDAY
AND TUESDAY.
IN THE EXTENDED...(TUESDAY NIGHT THROUGH SATURDAY)...
THIS PART OF THE FORECAST IS ALSO DRY. A RIDGE WILL RESIDE OVER THE
PLAINS THROUGH THURSDAY AND THEN SHIFT EAST FRIDAY AND SATURDAY WITH
FLOW BECOMING SOUTHWEST. SURFACE HIGH PRESSURE WILL CONTINUE OVER
THE CENTRAL PLAINS THROUGH WEDNESDAY FOLLOWED BY A TROUGH IN
EASTERN COLORADO FROM THURSDAY THROUGH SATURDAY.
MAX TEMPERATURES WILL GENERALLY BE IN THE MID TO UPPER 50S WEDNESDAY
AND SATURDAY. MAX TEMPERATURES THURSDAY AND FRIDAY SHOULD WARM TO
THE UPPER 50S WITH LOWER 60S IN THE WESTERN FA. MIN TEMPERATURES
SHOULD COOL TO THE UPPER 20S AND LOWER 30S.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 400 PM MST SAT DEC 6 2014
KGLD...SOUTHEAST WIND AROUND 12KT AT TAF ISSUANCE WITH A SMALL
WINDOW OF 15G23KTS FROM 02Z-05Z UNDER A VFR OVERCAST SKY.
STRATUS/BR REACHES THE TERMINAL FROM THE EAST AROUND 06Z WITH IFR
CIGS EXPECTED FROM 08Z-11Z WITH WINDS FROM THE SOUTH AROUND 10KTS.
AROUND 12Z WINDS VEER TO THE SOUTHWEST 5-10KTS PUSHING THE STRATUS
SLOWLY EAST ALLOWING FOR VFR CONDITIONS TO RETURN. WINDS THEN GO
WEST 5-10KTS AROUND 15Z THEN NORTHWEST 13G21KT IN THE 18Z-22Z
TIMEFRAME UNDER A FEW FAIR WEATHER CUMULUS CLOUDS. GUSTS DISSIPATE
AROUND 23Z WITH A FEW HIGH CLOUDS POSSIBLE.
KMCK...SOUTHEAST WIND 5-10KT AT TAF ISSUANCE UNDER A VFR OVERCAST
SKY. STRATUS/DRIZZLE/BR WITH IFR CONDITIONS REACH THE TERMINAL
FROM THE EAST AROUND 08Z AND CONTINUE THROUGH 17Z BEFORE WINDS
VEER AROUND TO THE NORTHWEST NEAR 10KTS BY 18Z. THIS WILL SCOUR
OUT THE STRATUS PRODUCING VFR CONDITIONS FROM 18Z THROUGH THE REST
OF THE TAF PERIOD.
IT SHOULD BE NOTED THAT IN THESE SCENARIOS THAT HIGH RESOLUTION
MODELS OCCASIONALLY DONT PUSH THE STRATUS FAR ENOUGH WEST...BY AT
LEAST ONE ROW OF COUNTIES. IF THIS VERIFIES STRATUS/BR (POSSIBLY
FG WITH VLIFR CONDITIONS) MAY TAKE UP TO AN ADDITIONAL 3 HOURS TO
MOVE OUT OF BOTH TERMINALS. WITH A THICK OVERCAST SKY HARD TO
WATCH STRATUS PROGRESSION ON SATELLITE IMAGERY SO WILL HAVE TO
WATCH METARS AND RUC/HRRR AND 00Z NAM MODEL DATA.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...FS
AVIATION...99
AREA FORECAST DISCUSSION
NWS GOODLAND KS
208 PM MST SAT DEC 6 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 207 PM MST SAT DEC 6 2014
EARLY AFTERNOON WV IMAGERY AND RAP H5 ANALYSIS SHOW PROGRESSIVE
TROUGH-RIDGE TROUGH PATTERN ACROSS US WITH RIDGE CURRENTLY
EXTENDING FROM SOUTH CENTRAL CANADA ACROSS THE CENTRAL PLAINS. SW
FLOW IS IN PLACE FROM THE FOUR CORNERS REGION AND INTO WESTERN KS
WITH SHORTWAVE TROUGH MOVING OUT OF THE GREAT BASIN TOWARDS THE
CENTRAL ROCKIES. AT THE SURFACE LEE TROUGH IS IN PLACE OVER
EASTERN COLORADO WITH SOUTHERLY FLOW ACROSS OUR CWA.
AS SHORTWAVE TROUGH TRANSITIONS EASTWARD STATIONARY
FRONT/BAROCLINIC ZONE WITH SHIFT NORTH AND EAST ALLOWING FOR
SOUTHEAST MOISTURE RETURN INTO THE EASTERN HALF OF OUR CWA.
MIDLEVEL MOISTURE/UPPER LEVEL FORCING COULD ALLOW FOR A BRIEF
PERIOD OF LIGHT RAIN SHOWERS LATE TONIGHT...HOWEVER MODEL
SOUNDINGS INDICATE A SIGNIFICANT DRY LAYER WOULD LIKELY PREVENT
ANY ELEVATED PRECIPITATION FROM REACHING THE SURFACE.
MAIN CONCERN WILL BE POTENTIAL FOR DENSE FOG DEVELOPMENT AND
POTENTIAL FOR DRIZZLE ACROSS EASTERN CWA LATE TONIGHT THROUGH
SUNDAY MORNING. NAM/RAP SHOW WEAK SURFACE CONVERGENCE IN PROXIMITY
OF BAROCLINIC ZONE WHICH COULD PROVIDE ENOUGH LIFT WITHIN SHALLOW
SATURATED LAYER TO ALLOW FOR DRIZZLE DEVELOPMENT. THIS COULD BE
MORE OF A STRATUS/DRIZZLE EVENT...THOUGH CONSIDERING THE GOOD
MOISTURE RETURN LOWER VISIBILITIES ARE CERTAINLY POSSIBLE. HIGH
CLOUDS HAVE ALREADY BEEN HAVING AN IMPACT ON MIXING THIS
AFTERNOON...AND WITH THICKENING/LOWERING CLOUDS THOUGH THE NIGHT
(ALONG WITH TD VALUES INCREASING TO MID/UPPER 30S IN THE
EAST)...RADIATIONAL COOLING WILL BE LIMITED. NOT ONLY COULD THIS
LIMIT DENSE FOG DEVELOPMENT...BUT THIS MAKES FREEZING
FOG/FREEZING DRIZZLE UNLIKELY AT THIS POINT. AT THIS POINT HOLDING
OFF ON HIGHLIGHTS SEEMS THE BEST COURSE.
WITH SHIFT BACK TO SW FLOW AS SHORTWAVE RIDGING BUILDS BACK INTO
THE ROCKIES THERE SHOULD BE RAPID IMPROVEMENT IN CONDITIONS
SUNDAY.CLEARING SKIES AND WAA THROUGH THE AFTERNOON SHOULD ALLOW
HIGHS TO WARM TO AROUND 60F...THOUGH STRATUS MAY HOLD ON A LITTLE
LONGER IN OUR EASTERN CWA LIMITING DAYTIME MIXING AND KEEPING
HIGHS IN THE LOW TO MID 50S.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 207 PM MST SAT DEC 6 2014
UPPER FLOW WILL BE NORTHWEST SUNDAY NIGHT AHEAD OF A RIDGE THAT WILL
BUILD INTO THE ROCKIES AND PLAINS MONDAY AND TUESDAY. SURFACE HIGH
PRESSURE WILL RESIDE OVER THE PLAINS THROUGH THIS TIME.
DRY CONDITIONS WILL CONTINUE ACROSS THE FA THROUGH TUESDAY.
SUBSIDENCE AND OR A LACK OF SIGNIFICANT FORCING ALONG WITH A LACK OF
LAYER MEAN RH WILL PROVIDE SUPPORT FOR THE DRY CONDITIONS. POPS
WILL BE NIL FROM SUNDAY NIGHT THROUGH TUESDAY.
MIN TEMPERATURES SHOULD BE IN THE MID AND UPPER 20S SUNDAY AND
MONDAY NIGHTS. MAX TEMPERATURES SHOULD RISE TO THE MID 50S MONDAY
AND TUESDAY.
IN THE EXTENDED...(TUESDAY NIGHT THROUGH SATURDAY)...
THIS PART OF THE FORECAST IS ALSO DRY. A RIDGE WILL RESIDE OVER THE
PLAINS THROUGH THURSDAY AND THEN SHIFT EAST FRIDAY AND SATURDAY WITH
FLOW BECOMING SOUTHWEST. SURFACE HIGH PRESSURE WILL CONTINUE OVER
THE CENTRAL PLAINS THROUGH WEDNESDAY FOLLOWED BY A TROUGH IN
EASTERN COLORADO FROM THURSDAY THROUGH SATURDAY.
MAX TEMPERATURES WILL GENERALLY BE IN THE MID TO UPPER 50S WEDNESDAY
AND SATURDAY. MAX TEMPERATURES THURSDAY AND FRIDAY SHOULD WARM TO
THE UPPER 50S WITH LOWER 60S IN THE WESTERN FA. MIN TEMPERATURES
SHOULD COOL TO THE UPPER 20S AND LOWER 30S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1004 AM MST SAT DEC 6 2014
VFR CONDITIONS WILL PERSIST AT KGLD AND KMCK AT LEAST THROUGH
08Z. AFTER 08Z LOW LEVEL MOISTURE WILL BEGIN TO ADVECT NORTH AND
EAST WITH LOW STRATUS...FOG...AND POSSIBLY DRIZZLE SPREADING INTO
KMCK. KGLD LOOKS TO BE FAR ENOUGH WEST THAT CONDITIONS SHOULD
REMAIN VFR THROUGH THE TAF PERIOD. IFR CIGS APPEAR
LIKELY...HOWEVER THE CUTOFF OF POTENTIAL DENSE FOG/DRIZZLE IS
DEPICTED VERY CLOSE TO KMCK TERMINAL. ITS TOO EARLY WITH LIMITED
CONFIDENCE TO ADD LOWER CONDITIONS TO KMCK AT THIS POINT...BUT I
PLAN ON KEEPING IFR CIG AND MVFR VIS GROUP IN THE 10-15Z PERIOD.
GUSTY WINDS AT KGLD WILL DIMINISH AROUND SUNSET TODAY...WITH WINDS
AT BOTH TERMINALS REMAINING BELOW 12KT THROUGH THE REST OF THE TAF
PERIOD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...FS
AVIATION...DR
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
917 AM CST SAT DEC 6 2014
...UPDATE TO SYNOPSIS...
.SYNOPSIS...
ISSUED AT 915 AM CST SAT DEC 6 2014
WV IMAGERY AND 12Z UPPER AIR ANALYSIS INDICATE A WEAK UPPER LEVEL
RIDGE OF HIGH PRESSURE MOVING EASTWARD ACROSS THE WESTERN HIGH
PLAINS. MEANWHILE, AN UPPER LEVEL SHORTWAVE TROUGH IS PUSHING ASHORE
INTO SOUTHERN CALIFORNIA. NEAR THE SURFACE, A BROAD AREA OF HIGH
PRESSURE EXTENDS FROM THE UPPER MIDWEST SOUTHWEST INTO THE CENTRAL
PLAINS OF KANSAS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 210 AM CST SAT DEC 6 2014
A SOUTHEASTERLY FLOW WILL DEVELOP BY LATE AFTERNOON AS A TROUGH
OF LOW PRESSURE BEGINS DEEPENS ALONG THE LEE OF THE ROCKIES AND A
SURFACE HIGH MOVES EAST TOWARDS THE MID MISSISSIPPI VALLEY. NAM,
RAP, NMM, AND ARW WERE ALL IN GOOD AGREEMENT WITH MORE HUMID AIR
IN LOWER LEVELS SPREADING BACK INTO SOUTHWEST KANSAS BY EARLY
TONIGHT AS THIS SOUTHEASTERLY FLOW DEVELOPS. BASED ON THE
AGREEMENT BETWEEN THE NEAR TERM MODELS AND EVEN RUN TO RUN
CONSISTENCY WILL EXPAND THE FOG POTENTIAL ACROSS ALL OF WESTERN
KANSAS TONIGHT BASED ON INCREASING LOW LEVEL MOISTURE AND UPSLOPE
FLOW. DENSE FOG ALSO MAY BE POSSIBLE AFTER MIDNIGHT EAST OF
HIGHWAY 283 GIVEN THE LIGHTER LOW LEVEL WINDS. DEPTH OF THIS LOW
LEVEL MOISTURE WILL STAY BELOW 3000FT AGL SO AM NOT ANTICIPATING
DRIZZLE DEVELOPMENT. HOWEVER WITH WARM AIR ADVECTION, MOISTURE,
AND WEAK ISENTROPIC LIFT DEVELOPING AHEAD OF AN UPPER LEVEL TROUGH
ACROSS SOUTH CENTRAL AND NORTH CENTRAL KANSAS WILL GO AHEAD AND
INSERT A CHANCE FOR SPRINKLES OR EVEN AN ISOLATED RAIN SHOWER. AS
FOR LOWS TONIGHT WENT ABOVE ALL GUIDANCE GIVEN THE MID TO UPPER 30
DEGREE DEWPOINTS RETURNING DURING THE OVERNIGHT HOURS.
AS FOR TODAY MID AND HIGH CLOUDS WILL INCREASE FROM THE WEST WITH
CLOUDY AFTERNOON SKIES LIKELY FOR ALL OF WESTERN KANSAS BY LATE
DAY. NET 24 HOUR TEMPERATURE TRENDS FROM 00Z SATURDAY TO 00Z
SUNDAY INDICATE AT 3 TO 5C COOL DOWN WHICH WOULD FAVOR THE WARMER
MAV/MOSGUIDE. HOWEVER GIVEN THE INCREASING CLOUD COVER WILL TREND
TOWARDS THE COOLER MET GUIDANCE FOR HIGHS WHICH ALSO WAS CLOSE TO
THE PREVIOUS FORECAST.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 407 AM CST SAT DEC 6 2014
A RELATIVELY CHALLENGING FORECAST LIES AHEAD IN THE 24 TO 60 HOUR
TIMEFRAME, PRIMARILY WITH RESPECT TO STRATUS DEVELOPMENT, FOG AND
POTENTIAL FOR VERY LIGHT SHOWERS. SUNDAY MORNING WILL LIKELY BEGIN
WITH WIDESPREAD LOW STRATUS AND AT LEAST SOME POTENTIAL FOR AREAS
OF...OR EVEN WIDESPREAD FOG EVEN IF NOT NECESSARILY DENSE.
BOUNDARY LAYER MOISTURE ADVECTION SHOULD BE DECREASING AS THE
SURFACE WINDS BECOME MORE SOUTHWEST TO WESTERLY AIDING IN DRYING
OUT THE CLOUD LAYER BY THE AFTERNOON. ADDITIONALLY, THE NMM/ARW
AND NAM INDICATE ANY LIGHT SHOWERS ASSOCIATED WITH THE MID LEVEL
WARM ADVECTION/ DEFORMATION AXIS SHOULD BE OVER BY NOON AS WELL.
ALTHOUGH SOME FOG DEVELOPMENT IS ALSO POSSIBLE ACROSS THE
EASTERNMOST COUNTIES MONDAY MORNING, THE BETTER BOUNDARY LAYER
MOISTURE WILL HAVE BEEN REMOVED WHICH WILL NOT FAVOR DEEPER
STRATUS DEVELOPMENT. THE PATTERN SUPPORTS FOG AND STRATUS BETTER
ONCE AGAIN BY MONDAY NIGHT AND TUESDAY MORNING WITH WHAT THE NAM
SHOWS AS AN UPTICK IN SURFACE LAYER MOISTURE ALONG A COLD FRONTAL
BOUNDARY. A CONVINCING SURFACE MOISTURE CONVERGENCE PATTERN
SOMEWHERE ROUGHLY FROM NORTHERN OKLAHOMA THROUGH EAST CENTRAL
COLORADO COULD RESULT.
DECENT AGREEMENT ACROSS MODEL DATA AND MOS EXISTS WITH RESPECT TO
THE DAILY HIGHS SUNDAY THROUGH TUESDAY, MAINLY IN THE MID 50S TO
AROUND 60 FAR WEST. TEMPERATURES WILL WARM FASTEST WEST OF HIGHWAY
283 AS THE STRATUS ERODES SUNDAY. TUESDAY MAY BRING COOLER
TEMPERATURES BEHIND THE COOL BOUNDARY ESPECIALLY IN LOCATIONS LIKE
HAYS AND STAFFORD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 559 AM CST SAT DEC 6 2014
IFR STRATUS WAS RAPIDLY ADVANCING WESTWARD ACROSS SOUTH CENTRAL
KANSAS THIS MORNING. THE HRRR HAD A REASIONABLE HANDLE ON THE
AREAL COVERAGE AND SPATIAL TRENDS. WITH SUCH UNCERTAINTY IN THE
IMPACTS FOR KDDC, WE`VE ADDED A TEMPO PERIOD FOR 500 FT CIELINGS
FOR THE NEXT 3 HOURS WHICH MIGHT BE AMENDED WITHIN THAT
TIMEFRAME. VFR CONDITIONS SHOULD THEN PREVAIL AT LEAST UNTIL THE
OVENIGHT HOURS WHEN STRATUS AND FOG MAY REDEVELOP.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 47 37 58 34 / 0 0 20 0
GCK 48 38 59 29 / 0 0 10 0
EHA 53 41 62 35 / 0 0 10 0
LBL 51 39 59 31 / 0 0 10 0
HYS 45 34 54 35 / 0 0 20 0
P28 47 37 54 35 / 0 0 20 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JJOHNSON
SHORT TERM...BURGERT
LONG TERM...RUSSELL
AVIATION...RUSSELL
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
601 AM CST SAT DEC 6 2014
...UPDATED AVIATION...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 210 AM CST SAT DEC 6 2014
A SOUTHEASTERLY FLOW WILL DEVELOP BY LATE AFTERNOON AS A TROUGH
OF LOW PRESSURE BEGINS DEEPENS ALONG THE LEE OF THE ROCKIES AND A
SURFACE HIGH MOVES EAST TOWARDS THE MID MISSISSIPPI VALLEY. NAM,
RAP, NMM, AND ARW WERE ALL IN GOOD AGREEMENT WITH MORE HUMID AIR
IN LOWER LEVELS SPREADING BACK INTO SOUTHWEST KANSAS BY EARLY
TONIGHT AS THIS SOUTHEASTERLY FLOW DEVELOPS. BASED ON THE
AGREEMENT BETWEEN THE NEAR TERM MODELS AND EVEN RUN TO RUN
CONSISTENCY WILL EXPAND THE FOG POTENTIAL ACROSS ALL OF WESTERN
KANSAS TONIGHT BASED ON INCREASING LOW LEVEL MOISTURE AND UPSLOPE
FLOW. DENSE FOG ALSO MAY BE POSSIBLE AFTER MIDNIGHT EAST OF
HIGHWAY 283 GIVEN THE LIGHTER LOW LEVEL WINDS. DEPTH OF THIS LOW
LEVEL MOISTURE WILL STAY BELOW 3000FT AGL SO AM NOT ANTICIPATING
DRIZZLE DEVELOPMENT. HOWEVER WITH WARM AIR ADVECTION, MOISTURE,
AND WEAK ISENTROPIC LIFT DEVELOPING AHEAD OF AN UPPER LEVEL TROUGH
ACROSS SOUTH CENTRAL AND NORTH CENTRAL KANSAS WILL GO AHEAD AND
INSERT A CHANCE FOR SPRINKLES OR EVEN AN ISOLATED RAIN SHOWER. AS
FOR LOWS TONIGHT WENT ABOVE ALL GUIDANCE GIVEN THE MID TO UPPER 30
DEGREE DEWPOINTS RETURNING DURING THE OVERNIGHT HOURS.
AS FOR TODAY MID AND HIGH CLOUDS WILL INCREASE FROM THE WEST WITH
CLOUDY AFTERNOON SKIES LIKELY FOR ALL OF WESTERN KANSAS BY LATE
DAY. NET 24 HOUR TEMPERATURE TRENDS FROM 00Z SATURDAY TO 00Z
SUNDAY INDICATE AT 3 TO 5C COOL DOWN WHICH WOULD FAVOR THE WARMER
MAV/MOSGUIDE. HOWEVER GIVEN THE INCREASING CLOUD COVER WILL TREND
TOWARDS THE COOLER MET GUIDANCE FOR HIGHS WHICH ALSO WAS CLOSE TO
THE PREVIOUS FORECAST.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 407 AM CST SAT DEC 6 2014
A RELATIVELY CHALLENGING FORECAST LIES AHEAD IN THE 24 TO 60 HOUR
TIMEFRAME, PRIMARILY WITH RESPECT TO STRATUS DEVELOPMENT, FOG AND
POTENTIAL FOR VERY LIGHT SHOWERS. SUNDAY MORNING WILL LIKELY BEGIN
WITH WIDESPREAD LOW STRATUS AND AT LEAST SOME POTENTIAL FOR AREAS
OF...OR EVEN WIDESPREAD FOG EVEN IF NOT NECESSARILY DENSE.
BOUNDARY LAYER MOISTURE ADVECTION SHOULD BE DECREASING AS THE
SURFACE WINDS BECOME MORE SOUTHWEST TO WESTERLY AIDING IN DRYING
OUT THE CLOUD LAYER BY THE AFTERNOON. ADDITIONALLY, THE NMM/ARW
AND NAM INDICATE ANY LIGHT SHOWERS ASSOCIATED WITH THE MID LEVEL
WARM ADVECTION/ DEFORMATION AXIS SHOULD BE OVER BY NOON AS WELL.
ALTHOUGH SOME FOG DEVELOPMENT IS ALSO POSSIBLE ACROSS THE
EASTERNMOST COUNTIES MONDAY MORNING, THE BETTER BOUNDARY LAYER
MOISTURE WILL HAVE BEEN REMOVED WHICH WILL NOT FAVOR DEEPER
STRATUS DEVELOPMENT. THE PATTERN SUPPORTS FOG AND STRATUS BETTER
ONCE AGAIN BY MONDAY NIGHT AND TUESDAY MORNING WITH WHAT THE NAM
SHOWS AS AN UPTICK IN SURFACE LAYER MOISTURE ALONG A COLD FRONTAL
BOUNDARY. A CONVINCING SURFACE MOISTURE CONVERGENCE PATTERN
SOMEWHERE ROUGHLY FROM NORTHERN OKLAHOMA THROUGH EAST CENTRAL
COLORADO COULD RESULT.
DECENT AGREEMENT ACROSS MODEL DATA AND MOS EXISTS WITH RESPECT TO
THE DAILY HIGHS SUNDAY THROUGH TUESDAY, MAINLY IN THE MID 50S TO
AROUND 60 FAR WEST. TEMPERATURES WILL WARM FASTEST WEST OF HIGHWAY
283 AS THE STRATUS ERODES SUNDAY. TUESDAY MAY BRING COOLER
TEMPERATURES BEHIND THE COOL BOUNDARY ESPECIALLY IN LOCATIONS LIKE
HAYS AND STAFFORD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 559 AM CST SAT DEC 6 2014
IFR STRATUS WAS RAPIDLY ADVANCING WESTWARD ACROSS SOUTH CENTRAL
KANSAS THIS MORNING. THE HRRR HAD A REASIONABLE HANDLE ON THE
AREAL COVERAGE AND SPATIAL TRENDS. WITH SUCH UNCERTAINTY IN THE
IMPACTS FOR KDDC, WE`VE ADDED A TEMPO PERIOD FOR 500 FT CIELINGS
FOR THE NEXT 3 HOURS WHICH MIGHT BE AMENDED WITHIN THAT
TIMEFRAME. VFR CONDITIONS SHOULD THEN PREVAIL AT LEAST UNTIL THE
OVENIGHT HOURS WHEN STRATUS AND FOG MAY REDEVELOP.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 47 37 58 34 / 0 10 20 0
GCK 48 38 59 29 / 0 10 10 0
EHA 53 41 62 35 / 0 10 10 0
LBL 51 39 59 31 / 0 10 10 0
HYS 45 34 54 35 / 0 10 20 0
P28 47 37 54 35 / 10 10 20 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BURGERT
LONG TERM...RUSSELL
AVIATION...RUSSELL
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1000 PM MST FRI DEC 5 2014
.SHORT TERM...(THIS AFTERNOON THROUGH SATURDAY)
ISSUED AT 1246 PM MST FRI DEC 5 2014
LATEST WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW RIDGING
BUILDING ACROSS INTER-MOUNTAIN WEST...WITH A SHORTWAVE TROUGH
CENTERED OVER EASTERN KANSAS. SUBSIDENCE/CLEARING IS IN PLACE
OVER OUR CWA. AT THE THE SURFACE...PRE FRONTAL LOW PRESSURE IS IN
PLACE ACROSS KANSAS AND EASTERN COLORADO WITH A WEAK COLD FRONT
OVER SOUTHERN NEBRASKA. AHEAD OF THE COLD FRONT TEMPERATURES HAVE
WARMED TO NEAR 60 DEGREES OVER MUCH OF THE CWA WITH A WELL MIXED
AIR MASS AND SURFACE TROUGH IN PLACE.
DRY FORECAST CONTINUES THROUGH SATURDAY AFTERNOON AS RIDGE
TRANSITIONS EASTWARD...AND SUBSIDENT/DRY AIR MASS LINGERS.
THIS AFTERNOON-TONIGHT...THE COLD FRONT OVER NEBRASKA WILL DROP
SOUTH THIS LATE THIS AFTERNOON AND EVENING WITH SURFACE HIGH
PRESSURE SETTLING IN FROM THE NORTHERN PLAINS. A COOLER/DRIER AIR
MASS WILL ACCOMPANY THIS HIGH PRESSURE SYSTEM...RETURNING
OVERNIGHT LOWS TO SEASONAL VALUES AROUND 20F. NAM/SREF CONTINUE TO
HINT AT SURFACE RH VALUES APPROACHING SATURATION AND POSSIBLE FOG
DEVELOPMENT. SOUNDINGS INDICATE THIS WILL BE VERY SHALLOW MOIST
LAYER...AND A DRY BL WILL GENERALLY INHIBIT FOG/STRATUS
DEVELOPMENT TONIGHT. HRRR/RAP CURRENTLY SHOWING NO FOG DEVELOPMENT
OVER OUR CWA. WHILE WE COULD SEE SOME SHALLOW FOG DEVELOPMENT...AT
THIS POINT CONFIDENCE IS JUST TOO LOW TO ADD.
SATURDAY...SHORTWAVE RIDING WILL TRANSITION THROUGH THE PLAINS ON
SATURDAY...WITH A SHORTWAVE TROUGH MOVING OUT OF THE GREAT BASIN
TOWARDS THE CENTRAL ROCKIES SATURDAY AFTERNOON. SW FLOW ALOFT WILL
DEVELOP BY SATURDAY AFTERNOON BETWEEN THESE FEATURES...WITH
INCREASING MID TO HIGH CLOUD COVER THROUGH THE DAY FROM THE WEST
TO THE EAST. LEE TROUGH AND SOUTHERLY FLOW WILL DEVELOP IN
RESPONSE TO THIS SHIFT IN FLOW ALOFT...SUPPORTING WAA ACROSS OUR
CWA AS THE SURFACE HIGH RETREATS EASTWARD.
NOT A LOT OF CONFIDENCE IN WHICH WILL WIN OUT: WAA WITH SOUTHERLY
FLOW OR LIMITED DIURNAL HEATING DUE TO INCREASING CLOUD COVER. I
ONLY MADE MINOR ADJUSTMENTS TO HIGH TEMP FORECAST...WHICH HAS
HIGHS NEAR 50 IN THE WEST AND THE MID 40S IN THE EAST. I COULD SEE
LOCATIONS IN THE WEST APPROACHING THE MID 50S IF CLOUD COVER HAS
MINIMAL IMPACT AND WE ACHIEVE FULL DAYTIME MIXING.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 222 PM MST FRI DEC 5 2014
AN UPPER TROUGH WILL MOVE INTO THE CENTRAL PLAINS SATURDAY NIGHT
FOLLOWED BY NORTHWEST FLOW SUNDAY. A RIDGE WILL MOVE EAST FROM THE
ROCKIES AND INTO THE PLAINS MONDAY. A SURFACE TROUGH WILL BE OVER
EASTERN COLORADO SATURDAY NIGHT AND THEN SHIFT EAST SUNDAY. SURFACE
HIGH PRESSURE WILL MOVE INTO THE CENTRAL PLAINS SUNDAY AND MONDAY.
THE UPPER TROUGH THAT COMES THROUGH THE FA SATURDAY NIGHT WILL BE
LACKING FOR MOISTURE. MOISTURE IMPROVES SOME AS THE SYSTEM EXITS
THE FAR EASTERN FA SUNDAY MORNING. FORECAST SOUNDINGS ACROSS THE FA
SATURDAY NIGHT SHOW CLOUD BASES FROM 8 TO 11KFT. FORECAST SOUNDINGS
SHOW SATURATION NEAR THE SURFACE EAST OF THE COLORADO LINE FOR
STRATUS/FOG AND LIGHT DRIZZLE WITH SURFACE TEMPERATURES ABOVE
FREEZING. SUBSIDENCE MOVES INTO THE FA LATE SUNDAY MORNING AND
CONTINUES THROUGH MONDAY. CONSEQUENTLY POPS WILL BE NIL FROM
SATURDAY NIGHT THROUGH MONDAY.
MIN TEMPERATURES SATURDAY AND SUNDAY NIGHTS WILL VARY FROM THE UPPER
20S TO AROUND 30. MAX TEMPERATURES SUNDAY SHOULD RANGE FROM 45 TO
50. MAX TEMPERATURES MONDAY SHOULD WARM TO THE MID AND UPPER 50S.
IN THE EXTENDED...(MONDAY NIGHT THROUGH FRIDAY)...A RIDGE WILL
PERSIST OVER THE CENTRAL PLAINS THROUGH THURSDAY AND THEN SHIFT EAST
FRIDAY WITH ZONAL FLOW EAST OF THE ROCKIES. SURFACE HIGH PRESSURE
WILL CONTINUE OVER THE CENTRAL PLAINS THROUGH TUESDAY. A TROUGH
MOVES INTO EASTERN COLORADO THURSDAY AND FRIDAY AS HIGH PRESSURE
DRIFTS EAST.
THE GFS BRINGS A SHORTWAVE THROUGH TUESDAY NIGHT WHILE THE ECMWF
KEEPS IT MUCH FURTHER NORTH. ALSO GFS SOUNDINGS SHOW VERY SHALLOW
MOISTURE WITH THE SYSTEM. FOR NOW WILL KEEP SILENT POPS FOR TUESDAY
NIGHT. AS A RESULT THE ENTIRE EXTENDED FORECAST WILL BE DRY WITH NO
OTHER SIGNIFICANT FORCING FOR THE REMAINING PERIODS.
MAX TEMPERATURES WILL VARY FROM THE MID 50S TO THE MID AND UPPER 50S
THURSDAY AND FRIDAY. MIN TEMPERATURES WILL COOL TO THE UPPER 20S TO
AROUND 30.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1000 PM MST FRI DEC 5 2014
FOR KGLD AND KMCK...VFR THROUGH THE PERIOD. SFC HIGH CURRENTLY
INFLUENCING THE AREAS WEATHER WILL SLOWLY MOVE EAST OVERNIGHT WITH
LOW PRESSURE DEEPENING ALONG THE FRONT RANGE. THE PRESSURE
GRADIENT BETWEEN THE TWO WILL SLOWLY STRENGTHEN DURING THE DAY
SATURDAY. LIGHT/VARIABLE WINDS AT TAF ISSUANCE THROUGH ROUGHLY
15Z. AFTER 15Z SOUTHEAST WINDS SLOWLY INCREASE DURING THE DAY
WITH GUSTS AROUND 20-25KTS AT KGLD BY 20Z...CONTINUING THROUGH
THE REST OF THE TAF PERIOD. AT KMCK ONLY 10KT WINDS FROM THE
SOUTHEAST EXPECTED AFTER 21Z. MID AND HIGH CLOUDS INCREASE FROM
THE SOUTHWEST AFTER 17Z.
WILL NEED TO MONITOR CIGS/VIS AT KMCK AT THE TAIL END OF THE TAF
PERIOD AS ABUNDANT BOUNDARY LAYER MOISTURE MOVES TOWARD THE
TERMINAL FROM THE EAST. CURRENT INDICATIONS SUGGEST MVFR/IFR
CONDITIONS POSSIBLE JUST AFTER 06Z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...FS
AVIATION...99
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1157 PM CST FRI DEC 5 2014
.AVIATION...
FOR THE 06/06Z TAFS...A FEW SHWRS CONTINUE TO FORM ALONG AND JUST
AHEAD OF A COLD FRONT WHICH IS JUST EAST OF A LINE FROM TXK...GGG
TO JSO. SHWRS AND POSSIBLY A FEW EMBEDDED TSTMS WILL LIKELY
INCREASE AFTER MIDNIGHT THROUGH EARLY SATURDAY MORNING WITH
FRONTAL FORCING. MVFR/IFR CIGS WILL GRADUALLY OVERTAKE THE REGION
BOTH AHEAD OF AND BEHIND THE FRONT...PERSISTING THROUGH THE
MORNING HOURS SATURDAY AND POSSIBLY EXTENDING INTO THE EARLY
AFTERNOON HOURS AT OUR ERN TERMINAL SITES. LIGHT SOUTH WINDS AHEAD
OF THE FRONT WILL QUICKLY SHIFT N/NW BEHIND THE FRONT WITH SPEEDS
NEAR 10 KTS IN ADDITION TO A FEW HIGHER GUSTS. /19/
&&
.PREV DISCUSSION... /ISSUED 856 PM CST FRI DEC 5 2014/
DISCUSSION...
FRONTAL BOUNDARY AS OF 8 PM WAS ORIENTED NEAR A FYV...FSM...
PRX...SEP LINE MOVING SLOWLY SOUTH AND EAST. A NARROW LINE OF
MOSTLY SHOWERS HAD DEVELOPED ALONG AND JUST AHEAD OF THIS BOUNDARY
ACROSS PORTIONS OF CENTRAL/SW AR INTO EXTREME SE OK AND PORTIONS
OF NE TX. THIS LINE LOOKED A LITTLE BETTER A COUPLE OF HOURS AGO
BUT WITH THE LOSS OF DAYTIME HEATING AND INSTABILITY LOOKING VERY
WEAK...NOT EXPECTING MUCH IN THE OF CONVECTION BUT CANNOT RULE
OUT AN ISOLATED LIGHTNING STRIKE THROUGHOUT THE NIGHT.
FRONT IS EXPECTED TO BE NEAR THE I-30 CORRIDOR BY MIDNIGHT AND
JUST EAST OF A LFK...SHV...ELD LINE BY 12Z IN THE MORNING. FOR THE
UPDATE...HAVE ORIENTED POPS HIGHEST ACROSS OUR EASTERN MOST ZONES
FOR THE REMAINDER OF THE NIGHT. THIS IS IN GOOD OVERALL AGREEMENT
WITH THE HRRR AND THE 00Z NAM OUTPUT WHICH PUTS THE BEST QPF
PROBABILITIES WHERE THE HIGHER MOISTURE CONTENT RESIDES.
ALSO ADDED THE LIKELIHOOD OF PATCHY DENSE FOG ACROSS ALL BUT OUR
EXTREME NW ZONES. TEMP/DEWPOINT DEPRESSIONS ARE VERY LOW ATTM AND
WITH THE VERY MOIST LOW LEVEL ATMOSPHERE PRESENT...UNTIL THE FRONT
COMES THROUGH...FOG IS A PRETTY GOOD BET OVERNIGHT.
NO ADDITIONAL CHANGES WERE NECESSARY THIS EVENING...UPDATE OUT
SHORTLY...13.
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 62 68 43 54 42 / 40 0 0 10 10
MLU 62 68 42 55 41 / 50 10 0 10 10
DEQ 52 61 39 49 38 / 10 0 0 10 10
TXK 55 64 41 51 39 / 30 0 0 10 10
ELD 58 68 41 51 39 / 50 0 0 10 10
TYR 55 66 45 55 42 / 20 0 0 20 20
GGG 57 68 43 54 42 / 20 0 0 10 10
LFK 62 71 48 57 46 / 20 10 10 20 20
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
19
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1156 AM EST SAT DEC 6 2014
.SYNOPSIS...
CROSSING LOW PRESSURE WILL CONTINUE TO SPREAD RAIN ACROSS THE
UPPER OHIO VALLEY REGION INTO THIS EVENING. HIGH PRESSURE WILL
GIVE A DRY DAY SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
MID MORNING UPDATE TO SLOW TIMING FOR RAIN TO END BASED ON LATEST
RADAR TRENDS AND INCOMING 12Z MODELS. STILL A CHANCE FOR SLEET TO
MIX IN FAR NORTH THIS AFTERNOON BUT NOTHING OF CONSEQUENCE. HOURLY
TEMPERATURES AND WINDS ADJUSTED TOWARD NEWEST LAMP GUIDANCE. WINDS
WERE INCREASED ESPECIALLY THIS EVENING AS SURFACE LOW PUSHES EAST.
PREVIOUS BELOW.
ADDITIONAL BASIN AVG FORECAST RAINFALL WAS GENLY PROGGED AT
APPROX A HALF TO THREE QUARTERS OF AN INCH USING SMOOTHED RFC
GUIDANCE AND MORE REASONABLE RAP AND GFS ASCENT FIELDS...A HEALTHY
AND PROLONGED RAINFALL THAT IS NOT EXPECTED TO CAUSE PROBLEMS.
PASSAGE OF THE LOW WL INITIATE THE COLD FRONTAL INVASION LTR TDA
AND INTO THE EVE. RESIDUAL RAIN WL THUS TURN TO SNOW LATE IN THE
DAY...BUT RAPIDLY INCRSG SBSDNC/LOW INVERSION LVLS WL ENSURE A
LACK OF ACCUMULATION POTENTIAL.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
RMNG SHWRS OF RAIN AND SNOW WL CONT TO DCRS IN COVERAGE THIS EVE.
BLDG HIGH PRES THEREAFTER WL MAINTAIN DRY WEA UNTIL THE APCH OF
THE NXT UPR TROF LATE ON MONDAY. SRN STREAM SHRTWV THROUGH THAT
TROF IS CURRENTLY PROGGED TO SPIN UP A COASTAL LOW BY MONDAY...NEWD
PROGRESS OF WHICH IS CURRENTLY PROGGED TO RMN SUFFICIENTLY E TO
FOREGO PROBLEM CONTRIBUTION FOR THE UPR OH REGION.
NEVERTHELESS...PCPN CHCS WL INCRS ON MON NGT INTO TUESDAY AS
ISENTROPIC LIFT...WARM MOIST ADVCTN DVLPS ON THE ERN FLANKS OF THE
HIGH AMPLITUDE ERN CONUS TROF.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
A DEEP ERN CONUS TROF IS PROGGED TO PERSIST THRU ERLY INTO THE
WKEND AS COASTAL SFC LOW PRES TRACKS UP THE E COAST. FCST SNW
SHWR CHCS INTO WED NGT UNTIL THE LOW AND UPR SPPRT EXITS THE RGN.
A WK SRTWV IS PROGGED TO ROTATE THRU THE GT LKS ARND THE MAIN TROF
FRI THOUGH WITH BLDG SFC HIGH PRES UNDER THE TROF KEPT A DRY FCST.
BLO SEASONAL TEMPS SHOULD RTN TO NR AVG BY LT WK.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
LATEST OBSERVATIONS BEGINNING TO SHOW IFR CONDITIONS IMPROVING TO
MVFR ACROSS WESTERN OHIO WHERE WINDS ALOFT VEER TO THE
WEST/NORTHWEST BEHIND THE AXIS OF THE MID-LEVEL TROUGH PASSING
ACROSS THE REGION. WINDS WILL INCREASE AND BE GUSTY THROUGH MID
AFTERNOON AS THE TROUGH PASSES THROUGH AND THE BOUNDARY LAYER
DEEPENS...TAPPING STRONGER WINDS ALOFT. WINDS GUSTS WILL RANGE
BETWEEN 15 AND 20KTS ON AVERAGE. MID AND UPPER LEVELS WILL QUICKLY
DRY OUT BEHIND THE TROUGH CLEARING OUT MID AND UPPER LEVEL CLOUDS
FROM WEST TO EAST STARTING LATER THIS AFTERNOON. THIS TREND WILL
CONTINUE TONIGHT AS HIGH PRESSURE BUILDS IN...WITH DRY CONDITIONS
AND LIMITED CLOUD COVERAGE EXPECTED ON SUNDAY.
OUTLOOK.../SUNDAY THROUGH WEDNESDAY/...
RESTRICTIONS ARE ANTICIPATED ON TUESDAY AS THE NEXT FRONTAL SYSTEM
TRANSITIONS OVER THE AREA.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1018 AM EST SAT DEC 6 2014
.SYNOPSIS...
CROSSING LOW PRESSURE WILL CONTINUE TO SPREAD RAIN ACROSS THE
UPPER OHIO VALLEY REGION INTO THIS EVENING. HIGH PRESSURE WILL
GIVE A DRY DAY SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
MID MORNING UPDATE TO SLOW TIMING FOR RAIN TO END BASED ON LATEST
RADAR TRENDS AND INCOMING 12Z MODELS. STILL A CHANCE FOR SLEET TO
MIX IN FAR NORTH THIS AFTERNOON BUT NOTHING OF CONSEQUENCE. HOURLY
TEMPERATURES AND WINDS ADJUSTED TOWARD NEWEST LAMP GUIDANCE. WINDS
WERE INCREASED ESPECIALLY THIS EVENING AS SURFACE LOW PUSHES EAST.
PREVIOUS BELOW.
ADDITIONAL BASIN AVG FORECAST RAINFALL WAS GENLY PROGGED AT
APPROX A HALF TO THREE QUARTERS OF AN INCH USING SMOOTHED RFC
GUIDANCE AND MORE REASONABLE RAP AND GFS ASCENT FIELDS...A HEALTHY
AND PROLONGED RAINFALL THAT IS NOT EXPECTED TO CAUSE PROBLEMS.
PASSAGE OF THE LOW WL INITIATE THE COLD FRONTAL INVASION LTR TDA
AND INTO THE EVE. RESIDUAL RAIN WL THUS TURN TO SNOW LATE IN THE
DAY...BUT RAPIDLY INCRSG SBSDNC/LOW INVERSION LVLS WL ENSURE A
LACK OF ACCUMULATION POTENTIAL.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
RMNG SHWRS OF RAIN AND SNOW WL CONT TO DCRS IN COVERAGE THIS EVE.
BLDG HIGH PRES THEREAFTER WL MAINTAIN DRY WEA UNTIL THE APCH OF
THE NXT UPR TROF LATE ON MONDAY. SRN STREAM SHRTWV THROUGH THAT
TROF IS CURRENTLY PROGGED TO SPIN UP A COASTAL LOW BY MONDAY...NEWD
PROGRESS OF WHICH IS CURRENTLY PROGGED TO RMN SUFFICIENTLY E TO
FOREGO PROBLEM CONTRIBUTION FOR THE UPR OH REGION. NEVERTHELESS...PCPN
CHCS WL INCRS ON MON NGT INTO TUESDAY AS ISENTROPIC LIFT...WARM
MOIST ADVCTN DVLPS ON THE ERN FLANKS OF THE HIGH AMPLITUDE ERN
CONUS TROF.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
A DEEP ERN CONUS TROF IS PROGGED TO PERSIST THRU ERLY INTO THE
WKEND AS COASTAL SFC LOW PRES TRACKS UP THE E COAST. FCST SNW
SHWR CHCS INTO WED NGT UNTIL THE LOW AND UPR SPPRT EXITS THE RGN.
A WK SRTWV IS PROGGED TO ROTATE THRU THE GT LKS ARND THE MAIN TROF
FRI THOUGH WITH BLDG SFC HIGH PRES UNDER THE TROF KEPT A DRY FCST.
BLO SEASONAL TEMPS SHOULD RTN TO NR AVG BY LT WK.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
WDSPRD IFR/OCNL LIFR CONDS ARE EXPD TO CONT TDA AS UPR OH VLY LOW
PRES BRINGS RAIN TO THE RGN. THE EXCEPTION IS MGW AND LBE WHERE
OCNL MVFR IS EXPD ERLY...WITH CONDS DCRG TO IFR BY MID TO LT MRNG
AS MORE FAVORABLE LLVL MOISTURE ADVECTS OVR THOSE SITES. INCRG
NRLY WNDS AND COND IMPROVEMENT TO LOW END MVFR ARE EXPD BY THIS
EVE AS THE SFC LOW SHIFTS E AND RAIN TAPERS OFF...WITH SKIES
EVENTUALLY SCT OUT TWD SUNRISE SUN MRNG.
OUTLOOK.../SUNDAY THROUGH WEDNESDAY/...
RSTRNS ARE EXPD MON NGT THRU WED AS LOW PRES BRINGS SNW SHWRS.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
638 AM EST SAT DEC 6 2014
.SYNOPSIS...
CROSSING LOW PRESSURE WILL CONTINUE TO SPREAD RAIN ACROSS THE
UPPER OHIO VALLEY REGION TODAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
NO MAJOR CHANGES WERE NEEDED FOR THE PRE DAWN UPDATE AS LOW PRES
MOVG UP THE OHIO VALLEY WL MAINTAIN RAIN ACROSS THE REGION INTO
THE AFTERNOON.
ADDITIONAL BASIN AVG FORECAST RAINFALL WAS GENLY PROGGED AT
APPROX A HALF TO THREE QUARTERS OF AN INCH USING SMOOTHED RFC
GUIDANCE AND MORE REASONABLE RAP AND GFS ASCENT FIELDS...A HEALTHY
AND PROLONGED RAINFALL THAT IS NOT EXPECTED TO CAUSE PROBLEMS.
PASSAGE OF THE LOW WL INITIATE THE COLD FRONTAL INVASION LTR TDA
AND INTO THE EVE. RESIDUAL RAIN WL THUS TURN TO SNOW LATE IN THE
DAY...BUT RAPIDLY INCRSG SBSDNC/LOW INVERSION LVLS WL ENSURE A
LACK OF ACCUMULATION POTENTIAL.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
RMNG SHWRS OF RAIN AND SNOW WL CONT TO DCRS IN COVERAGE THIS EVE.
BLDG HIGH PRES THEREAFTER WL MAINTAIN DRY WEA UNTIL THE APCH OF
THE NXT UPR TROF LATE ON MONDAY. SRN STREAM SHRTWV THROUGH THAT
TROF IS CURRENTLY PROGGED TO SPIN UP A COASTAL LOW BY MONDAY...NEWD
PROGRESS OF WHICH IS CURRENTLY PROGGED TO RMN SUFFICIENTLY E TO
FOREGO PROBLEM CONTRIBUTION FOR THE UPR OH REGION. NEVERTHELESS...PCPN
CHCS WL INCRS ON MON NGT INTO TUESDAY AS ISENTROPIC LIFT...WARM
MOIST ADVCTN DVLPS ON THE ERN FLANKS OF THE HIGH AMPLITUDE ERN
CONUS TROF.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
A DEEP ERN CONUS TROF IS PROGGED TO PERSIST THRU ERLY INTO THE
WKEND AS COASTAL SFC LOW PRES TRACKS UP THE E COAST. FCST SNW
SHWR CHCS INTO WED NGT UNTIL THE LOW AND UPR SPPRT EXITS THE RGN.
A WK SRTWV IS PROGGED TO ROTATE THRU THE GT LKS ARND THE MAIN TROF
FRI THOUGH WITH BLDG SFC HIGH PRES UNDER THE TROF KEPT A DRY FCST.
BLO SEASONAL TEMPS SHOULD RTN TO NR AVG BY LT WK.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
WDSPRD IFR/OCNL LIFR CONDS ARE EXPD TO CONT TDA AS UPR OH VLY LOW
PRES BRINGS RAIN TO THE RGN. THE EXCEPTION IS MGW AND LBE WHERE
OCNL MVFR IS EXPD ERLY...WITH CONDS DCRG TO IFR BY MID TO LT MRNG
AS MORE FAVORABLE LLVL MOISTURE ADVECTS OVR THOSE SITES. INCRG
NRLY WNDS AND COND IMPROVEMENT TO LOW END MVFR ARE EXPD BY THIS
EVE AS THE SFC LOW SHIFTS E AND RAIN TAPERS OFF...WITH SKIES
EVENTUALLY SCT OUT TWD SUNRISE SUN MRNG.
OUTLOOK.../SUNDAY THROUGH WEDNESDAY/...
RSTRNS ARE EXPD MON NGT THRU WED AS LOW PRES BRINGS SNW SHWRS.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
15/07
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
334 AM EST SAT DEC 6 2014
.SYNOPSIS...
CROSSING LOW PRESSURE WILL CONTINUE TO SPREAD RAIN ACROSS THE
UPPER OHIO VALLEY REGION TODAY.
&&
.NEAR TERM /THROUGH TODAY/...
NO MAJOR CHANGES WERE NEEDED FOR THE PRE DAWN UPDATE AS LOW PRES
MOVG UP THE OHIO VALLEY WL MAINTAIN RAIN ACROSS THE REGION INTO
THE AFTERNOON.
ADDITIONAL BASIN AVG FORECAST RAINFALL WAS GENLY PROGGED AT
APPROX A HALF TO THREE QUARTERS OF AN INCH USING SMOOTHED RFC
GUIDANCE AND MORE REASONABLE RAP AND GFS ASCENT FIELDS...A HEALTHY
AND PROLONGED RAINFALL THAT IS NOT EXPECTED TO CAUSE PROBLEMS.
PASSAGE OF THE LOW WL INITIATE THE COLD FRONTAL INVASION LTR TDA
AND INTO THE EVE. RESIDUAL RAIN WL THUS TURN TO SNOW LATE IN THE
DAY...BUT RAPIDLY INCRSG SBSDNC/LOW INVERSION LVLS WL ENSURE A
LACK OF ACCUMULATION POTENTIAL.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY/...
RMNG SHWRS OF RAIN AND SNOW WL CONT TO DCRS IN COVERAGE THIS EVE.
BLDG HIGH PRES THEREAFTER WL MAINTAIN DRY WEA UNTIL THE APCH OF
THE NXT UPR TROF LATE ON MONDAY. SRN STREAM SHRTWV THROUGH THAT
TROF IS CURRENTLY PROGGED TO SPIN UP A COASTAL LOW BY MONDAY...NEWD
PROGRESS OF WHICH IS CURRENTLY PROGGED TO RMN SUFFICIENTLY E TO
FOREGO PROBLEM CONTRIBUTION FOR THE UPR OH REGION. NEVERTHELESS...PCPN
CHCS WL INCRS ON MON NGT INTO TUESDAY AS ISENTROPIC LIFT...WARM
MOIST ADVCTN DVLPS ON THE ERN FLANKS OF THE HIGH AMPLITUDE ERN
CONUS TROF.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
A DEEP ERN CONUS TROF IS PROGGED TO PERSIST THRU ERLY INTO THE
WKEND AS COASTAL SFC LOW PRES TRACKS UP THE E COAST. FCST SNW
SHWR CHCS INTO WED NGT UNTIL THE LOW AND UPR SPPRT EXITS THE RGN.
A WK SRTWV IS PROGGED TO ROTATE THRU THE GT LKS ARND THE MAIN TROF
FRI THOUGH WITH BLDG SFC HIGH PRES UNDER THE TROF KEPT A DRY FCST.
BLO SEASONAL TEMPS SHOULD RTN TO NR AVG BY LT WK.
&&
.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
WDSPRD IFR/OCNL LIFR CONDS ARE EXPD TO CONT TDA AS UPR OH VLY LOW
PRES BRINGS RAIN TO THE RGN. INCRG NRLY WNDS AND COND IMPROVEMENT
TO LOW END MVFR ARE EXPD BY THIS EVE AS THE SFC LOW SHIFTS E AND
RAIN TAPERS OFF.
OUTLOOK.../SUNDAY THROUGH WEDNESDAY/...
RSTRNS ARE EXPD MON NGT THRU WED AS LOW PRES BRINGS SNW SHWRS.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
15/07
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1248 AM EST SAT DEC 6 2014
.SYNOPSIS...
CROSSING LOW PRESSURE WILL CONTINUE TO SPREAD RAIN ACROSS THE
UPPER OHIO VALLEY REGION TODAY.
&&
.NEAR TERM /THROUGH TODAY/...
NO MAJOR CHANGES WERE NEEDED FOR THE POST MIDNGT UPDATE AS LOW
PRES MOVG UP THE OHIO VALLEY WL MAINTAIN RAIN ACROSS THE REGION
INTO THE AFTERNOON.
ADDITIONAL BASIN AVG FORECAST RAINFALL WAS GENLY PROGGED AT
APPROX A HALF TO THREE QUARTERS OF AN INCH USING SMOOTHED RFC
GUIDANCE AND MORE REASONABLE RAP AND GFS ASCENT FIELDS...A HEALTHY
AND PROLONGED RAINFALL THAT IS NOT EXPECTED TO CAUSE PROBLEMS.
PASSAGE OF THE LOW WL INITIATE THE COLD FRONTAL INVASION LTR TDA
AND INTO THE EVE. RESIDUAL RAIN WL THUS TURN TO SNOW LATE IN THE
DAY...BUT RAPIDLY INCRSG SBSDNC/LOW INVERSION LVLS WL ENSURE A
LACK OF ACCUMULATION POTENTIAL.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY/...
RMNG SHWRS OF RAIN AND SNOW WL CONT TO DCRS IN COVERAGE THIS EVE.
BLDG HIGH PRES THEREAFTER WL MAINTAIN DRY WEA UNTIL THE APCH OF
THE NXT UPR TROF LATE ON MONDAY. SRN STREAM SHRTWV IS CURRENTLY
PROGGED TO SPIN UP A COASTAL LOW BY MONDAY...NEWD PROGRESS OF
WHICH IS CURRENTLY PROGGED TO RMN SUFFICIENTLY E TO FOREGO
PROBLEMS FOR THE UPR OH REGION. NEVERTHELESS...PCPN CHCS WL INCRS
ON MON NGT INTO TUESDAY AS ISENTROPIC LIFT...WARM MOIST ADVCTN
DVLPS ON THE ERN FLANKS OF THE HIGH AMPLITUDE ERN CONUS TROF.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
CHANGES TO THE EXTENDED WERE BASED ON A BLEND OF THE NEW WPC PROGS
AND 12Z GFS WHICH HAVE SHIFTED TOWARD THE 00Z ECMWF SOLUTION MID
WEEK WITH CLSOED LOW DEVELOPING OVER THE NORTHEAST AND A COASTAL
STORM POSSIBLE INTO NEW ENGLAND. MID WEEK TEMPERATURES ADJUSTED
COLDER WITH SNOW SHOWERS IN NORTHWEST FLOW. DRY AND SEASONAL LATE WEEK.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
WDSPRD IFR/OCNL LIFR CONDS ARE EXPD TO CONT TDA AS UPR OH VLY LOW
PRES BRINGS RAIN TO THE RGN. INCRG NRLY WNDS AND COND IMPROVEMENT
TO LOW END MVFR ARE EXPD BY THIS EVE AS THE SFC LOW SHIFTS E AND
RAIN TAPERS OFF.
OUTLOOK.../SUNDAY THROUGH WEDNESDAY/...
RSTRNS ARE EXPD MON NGT THRU WED AS LOW PRES BRINGS SNW SHWRS.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
15/07
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
652 PM EST SUN DEC 7 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 338 PM EST SUN DEC 7 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A WELL-DEFINED SHORTWAVE
MOVING ACROSS MT EARLY THIS MORNING. THIS WAVE WILL BE THE FEATURE
OF INTEREST IN THE SHORT TERM AS IT SHIFTS E...REACHING THE UPPER
GREAT LAKES MON. AT THE SFC...SHORTWAVE WAS SUPPORTING LOW PRES OVER
SRN SASKATCHEWAN. TO THE E...HIGH PRES CENTER HAS SLIPPED E OF LAKE
SUPERIOR/UPPER MI. STRONG WAA/ISENTROPIC ASCENT REGIME BTWN THE
SHORTWAVE AND DEPARTING HIGH PRES HAS LED TO QUITE A BIT OF MID
LEVEL CLOUDINESS SPREADING INTO UPPER MI DURING THE NIGHT. RADARS
ARE ALSO SHOWING RETURNS...BUT SO FAR...THE FARTHEST S ANY -SN HAS
BEEN REPORTED IN OBS IS AT THUNDER BAY ONTARIO AS DRY AIR NOTED
BELOW 750MB ON 00Z KINL SOUNDING IS WORKING TO LIMIT SOUTHWARD
EXTENT OF -SN REACHING THE GROUND.
TODAY...SHORTWAVE OVER MT WILL MOVE TO THE ERN DAKOTAS WITH
ASSOCIATED SFC LOW REACHING FAR SE MANITOBA BY EVENING. STRONG
WAA/ISENTROPIC ASCENT WHICH IS CURRENTLY FOCUSED INTO NRN MN WILL
SHIFT E TODAY...BUT MODELS CONTINUE TO INDICATE THAT LOW-LEVELS WILL
FAIL TO MOISTEN ACROSS UPPER MI DUE TO A PERSISTENT FEED OF
LOW-LEVEL DRY AIR FROM DEPARTING HIGH PRES. TO THE W...AXIS OF
850-700MB MOISTURE TRANSPORT AND LOWERING CONDENSATION PRES DEFICITS
AHEAD OF SHORTWAVE REMAINS JUST W OF THE AREA THRU THE AFTN. SO...
NOT EXPECTING ANY PCPN DURING THE DAYLIGHT HRS TODAY. TEMPS SHOULD
REACH THE UPPER 20S/LWR 30S.
TONIGHT...AS RIBBON OF 850-700MB MOISTURE TRANSPORT...ISENTROPIC
ASCENT ENHANCED BY 850MB WINDS OF 40-50KT AND DEEP LAYER QVECTOR
CONVERGENCE IN ADVANCE OF APPROACHING SHORTWAVE TRANSLATE W-E...
CATEGORICAL POPS STILL APPEAR ON TRACK...SPREADING INTO WRN UPPER MI
THIS EVENING AND INTO THE CNTRL OVERNIGHT. SNOW MAY NOT REACH THE
FAR E AROUND KERY UNTIL TOWARD 12Z. AVERAGED MODEL QPF INDICATES 0.1
TO 0.2 INCHES OF QPF TONIGHT...SUGGESTING 1-2 INCHES OF SNOW IN
GENERAL AS SNOW TO WATER RATIOS SHOULDN`T BE MUCH MORE THAN 10-12 TO
1. THESE NUMBERS APPEAR ON TRACK FROM AN ISENTROPIC STANDPOINT AS
MIXING RATIOS OF AROUND 3G/KG ARE AVBL WITH CLOSE TO 6HRS OF ASCENT.
SNOW ACCUMULATIONS WILL BE LIGHTEST OVER THE E SINCE SNOW DOESN`T
BEGIN UNTIL NEAR THE END OF THE TONIGHT PERIOD. CLOUDS/PCPN/WINDS
WILL KEEP TEMPS FROM FALLING MORE THAN ROUGHLY 2-4 DEGREES FROM
TODAYS HIGH TEMPS.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 323 PM EST SUN DEC 7 2014
GOOD AGREEMENT IN LARGER SCALE PATTERN THROUGH THE LENGTH OF THE
LONG TERM INTO NEXT WEEKEND. LOW PRESSURE THAT CROSSES THE AREA ON
MONDAY WILL BE WEAKENING AS IS SLIDES EAST OF LK SUPERIOR BY TUESDAY
MORNING. NNW FLOW LAKE ENHANCEMENT...AT LEAST IN DIMINISHING
STATE...EXPECTED MONDAY EVENING OVER WESTERN UPR MICHIGAN...ESPECIALLY
OVER THE KEWEENAW WHERE DEEPER MOISTURE TO H7 LINGERS AND H85 TEMPS
DROP TO AROUND -8C. LOW-LEVEL WINDS NOT TOO CYCLONIC SO CONVERGENCE
WILL BE WEAK. SNOW ACCUMS MONDAY EVENING SHOULD BE NOTHING MORE THAN
A COUPLE INCHES FOR NW CWA. DEPARTING DEEP MOISTURE AND LIMITED COLD
AIR /H9-H85 TEMPS -8C TO -10C/ IS MARGINAL FOR PURE LAKE EFFECT...SO
SNOW SHOWERS SHOULD DIMINISH SHARPLY AFTER MIDNIGHT ALL CWA. LIGHT
LES COULD CONTINUE INTO TUESDAY MORNING...BUT CONTINUED DRYING AND
SFC RIDGING WILL SPELL AN END TO LES TUE AFTN.
BEYOND MONDAY NIGHT...APPEARS QUIET WITH NO BIG STORMS OVER THE
UPPER GREAT LAKES. UPPER LEVEL FLOW FEATURES RIDGING BUILDING OVER
THE MID PORTION OF THE CONUS MID TO LATE WEEK. MEANWHILE...DEEPENING
TROUGH OVER THE EASTERN CONUS WILL RESULT IN STRONG EAST COAST STORM
THAT WILL BRING HEAVY SNOW TO INTERIOR PORTIONS OF THE NORTHEAST AND
NEW ENGLAND. THE BUILDING UPR RIDGE WILL LEAD TO SPRAWLING SFC RIDGE
FM CENTRAL PLAINS AND NORTHERN ONTARIO ON TUESDAY ONLY MOVING SLOWLY
TO NORTHERN QUEBEC TO LOWER MISSISSIPPI RIVER VALLEY BY FRIDAY.
COULD BE A COUPLE CHILLY NIGHTS INLAND ON TUESDAY NIGHT AND
WEDNESDAY NIGHT WITH THE RIDGE OVERHEAD AND AS PWATS ARE BLO 75 PCT
OF NORMAL. DEPENDING ON CLOUD COVER...MINS EITHER NIGHT MAY FALL
TOWARD ZERO. FOR NOW HAVE SOME SINGLE DIGITS ABOVE ZERO IN THERE
UNTIL CAN GET BETTER HANDLE ON EXTENT OF MID CLOUDS.
BY NEXT WEEKEND UPPER LEVEL RIDGE AXIS IS OVER THE WESTERN GREAT
LAKES. SW FLOW SFC-H85 WILL TRANSPORT HIGHER DWPNTS FM THE CNTRL
PLAINS INTO THE GREAT LAKES. YET IT IS NOT UNTIL SATURDAY NIGHT INTO
SUNDAY THAT SFC DWPNTS ARE FORECAST TO BE OVER 32F. SOUNDINGS FM GFS
INDICATE SHALLOWER MOISTURE THAN THEY SHOWED YDY FOR FRIDAY AND
SATURDAY...SO COULD HAVE AT LEAST SOME SUNSHINE WHICH WOULD ALLOW
TEMPS TO WARM INTO THE MID 30S TO LOWER 40S. SHOT UP SLIGHTLY HIGHER
THAN BLENDED GUIDANCE. ONCE DWPNTS RISE ABOVE FREEZING SATURDAY
NIGHT INTO SUNDAY...THERE WILL BE INCREASING PROSPECTS OF DRIZZLE
AND FOG AS THIS MOISTURE RIDES OVER GRADUAL MELTING SNOWPACK. ECMWF
AND GFS ALSO INDICATE MOISTURE DEPTH INCREASES WITH SOME WEAK LIFT
DEVELOPING DUE TO SHORTWAVE ENERGY WORKING OVER THE AREA OUT AHEAD
OF TROUGH AXIS OVER WESTERN CONUS. WILL HAVE SMALL POPS IN THERE FOR
RAIN LATE IN THE WEEKEND. ALSO WILL INCLUDE MENTION OF FOG SINCE
DWPNTS ARE FORECAST IN THE MID-UPR 30S.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 651 PM EST SUN DEC 7 2014
WITH LOW-LEVELS REMAINING DRY...VFR CONDITIONS WILL PREVAIL AT
KIWD/KCMX/KSAW THROUGH THE EARLY EVENING. THEN...LIGHT SNOW AHEAD OF
THE APPROACHING LOW PRES SYSTEM WILL SPREAD E INTO UPPER MI. ALL
TERMINALS ARE EXPECTED TO FALL TO MVFR. WITH SOMEWHAT HEAVIER SNOW
POSSIBLE...THERE MAY BE SOME PERIODS OF IFR VIS. LOOK FOR ALL SITES
TO LOWER TO IFR CIGS BY MON MORNING AS LOW-LVL MOISTURE GETS TRAPPED
UNDER A LOWERING SUBSIDENCE INVERSION. THE IFR CIGS SHOULD PERSIST
THROUGH THE AFTERNOON.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 338 PM EST SUN DEC 7 2014
TIGHTENING PRES GRADIENT AND PRES FALLS SHIFTING INTO THE UPPER
LAKES AHEAD OF AN APPROACHING LOW PRES WILL RESULT IN SOUTHERLY
GALES TONIGHT INTO MONDAY MORNING OVER THE EAST HALF OF LAKE
SUPERIOR. WINDS OVER THE W WL STAY MOSTLY BLO 30KT. AS LOW PRES/COLD
FRONT MOVE ACROSS THE UPPER LAKES LATE MON/MON EVENING...WINDS WILL
SHIFT TO THE NW-N. WITH SYSTEM TRENDING WEAKER AS IT
DEPARTS...EXPECT WINDS TO STAY BLO GALES MON NIGHT INTO TUE...NO
HIGHER THAN 30KT MAINLY CENTRAL AND EAST. HIGH PRES RIDGE ARRIVING
TUE NIGHT/WED MAY LINGER INTO THE END OF THE WEEK AND RESULT IN
WINDS UNDER 20KT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 10 AM EST MONDAY FOR LSZ267.
GALE WARNING UNTIL 10 AM EST MONDAY FOR LSZ266.
GALE WARNING UNTIL 3 AM EST MONDAY FOR LSZ248-249-265.
GALE WARNING UNTIL 3 AM EST MONDAY FOR LSZ250.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...JLA
AVIATION...JLB
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
314 PM CST Sat Dec 6 2014
.SHORT TERM: (Through Late Tonight)
Issued at 300 PM CST Sat Dec 6 2014
Low stratus located within the southern portion of a large high
pressure system continues to dominate the region at mid afternoon.
There has been a slow clearing trend to our north with the clearing
line located near the MO/IA border into northern IL. This high
pressure system will dominate tonight as it moves to the east with
low level flow gradually veering to easterly by mid evening and
then east-southeasterly overnight. Given the trends in the wind
field, there will probably be additional southward clearing into
the early evening then the northern edge will hold steady before
retreating back northwest overnight. The RAP H950 RH is the only
guidance that seems to have a decent handle on this evolution. The
abundance of clouds tonight would suggest MOS guadance is too low
on mins, with the coolest values expected across northeast MO and
west central IL.
Glass
.LONG TERM: (Sunday through Next Saturday)
Issued at 300 PM CST Sat Dec 6 2014
The high pressure system will continue to retreat on Sunday and
this will keep low clouds prevalent. Add in high clouds and it will
make for a mostly cloudy-cloudy day. There are some indications that
southern portions of the CWA could see some clearing from the
south of the low clouds, and hence warmer high temps are expected.
The next threat of precipitation will come Sunday night into
Monday morning. A short wave trof will dig into the mid-upper MS
valley. The large scale ascent associated with this wave along
increasing mid level moisture and low level warm advection should
be sufficient to generate some spotty/scattered precipitation
ahead of the attendant cold front. Temperature profiles indicate
the precipitation should be in the form of rain, with the highest
pops late Monday night across northeast MO and along and east of
the MS River on Monday morning. Monday should be milder with
decreasing clouds as first a prefrontal trof and then the cold
front then sweeps through the area. Another brief round of cold
air then dominates on Tuesday with expansive high pressure.
The upper air pattern will be in transition during the extended
period from Wednesday into next weekend. The eastern U.S. upper
trof/low will be progressive lifting northeast and eventually off
the Atlantic Seaboard. A northwest flow short wave in the wake of
the slowly retreating trof looks to impact our area sometime late
Wednesday into early Thursday, however present indications are any
precipitation threat should be confined to western MO. Heights
aloft then gradually rise in the wake of the shortwave trof and
high pressure departs, leading to southerly low level flow Friday
into the Saturday and a warming trend.
Glass
&&
.AVIATION: (For the 18z TAFs through 18z Sunday Afternoon)
Issued at 1147 AM CST Sat Dec 6 2014
Should see slow improvement in visibilities this afternoon but
only a slight gradual rise in ceiling heights, except at UIN where
the southward advancing clearing line across southern IA and
northwestern IL may make it to by late afternoon or early evening.
Elsewhere ceiling heights will likely only improve to around
1000 feet late this afternoon, then drop some late tonight along
with the redevelopment of at least light fog. Status clouds will
likely redevelop or advect back into UIN late tonight as the
surface/low level flow becomes easterly. For now will keep it
scattered in the UIN TAF tonight, but this may be too optimistic.
There should be more substantial improvement in the ceiling
heights at the other taf sites by late Sunday morning, possibly
into the MVFR catagory. Nly surface wind will gradually veer
around to an ely direction tonight, and a sely direction Sunday
morning as the surface ridge extending from MN southwest into the
TX panhandle moves eastward through our area.
Specifics for KSTL: The visibilities should become unrestricted by
late afternoon, but the ceiling height may only rise to around
1000 feet. The ceiling height may lower some late tonight along
with the redevelopment of at least light fog. Should see more
improvement on Sunday, possibly going VFR in the afternoon. Nly
surface wind will veer around to a nely direction this evening,
then to a sely direction by late Sunday morning.
GKS
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1146 PM CST FRI DEC 5 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 218 PM CST FRI DEC 5 2014
THE SHORT TERM FORECAST THROUGH SATURDAY IS RELATIVELY QUIET IN
TERMS OF MAJOR WEATHER ISSUES. MILD TEMPERATURES THIS AFTERNOON
WILL BE TEMPERED A BIT IN THE WAKE OF FRONTAL BOUNDARY PASSING
THROUGH THE FORECAST AREA AT THIS TIME. TEMPERATURES WILL ACTUALLY
BE NEAR NORMAL TONIGHT AND SATURDAY...THOUGH IT WILL FEEL QUITE A
BIT COOLER TONIGHT WITH UPPER TEENS AND 20S. DECENT MODEL AGREEMENT
WITH SOME LOWER CLOUDS TRYING TO SNEAK BACK WEST TONIGHT AND PUSH
INTO THE HIGHWAY 81 CORRIDOR AREA TOWARD DAWN SATURDAY AND LINGER
INTO THE MORNING. HAVE INCREASED CLOUDS IN THAT AREA...AND ADDED A
BIT OF PATCHY FOG FOG WHICH ALIGNS WELL WITH WFOS OMAHA AND TOPEKA
FORECAST. SOME CONCERN OF FOG IN THE NORTHWEST PART OF THE FORECAST
AREA...WHERE WINDS TURN NEARLY CALM. HRRR HINTS AT LOWER CLOUDS AND
VISIBILITY OVER PARTS OF THE SANDHILLS. WILL HOLD OFF FOR NOW BUT
WORTH NOTING HEADING INTO TONIGHT. BEYOND THAT...SATURDAY WILL SEE
MID/HIGH CLOUDS START TO INCREASE FROM THE WEST IN THE AFTERNOON AS
WARM ADVECTION INCREASES AHEAD OF NEXT WEATHER SYSTEM ON SUNDAY.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 218 PM CST FRI DEC 5 2014
GUIDANCE SUGGESTS THE LONG-TERM FORECAST PERIOD WILL START OFF WITH
UPPER TROPOSPHERIC RIDGING OVER THE CENTRAL CONUS AND A SUBTLE
TROUGH AXIS JUST WEST OF THE ROCKY MOUNTAINS AT 00Z SUNDAY. THIS
TROUGH AXIS IS EXPECTED TO SHIFT EAST SATURDAY NIGHT INTO
SUNDAY...WITH THIS TROUGH AXIS LIKELY CLEARING OUR AREA DURING THE
DAY SUNDAY. NORTHWESTERLY UPPER TROPOSPHERIC FLOW IS THEN EXPECTED
TO OVERTAKE THE CENTRAL CONUS THROUGH MUCH OF THE REMAINDER OF THE
LONG-TERM FORECAST PERIOD AS UPPER TROPOSPHERIC TROUGHING
STRENGTHENS OVER THE EASTERN CONUS AND RIDGING BUILDS ACROSS THE
WEST.
ALTHOUGH UNCERTAINTY REMAINS...THERE REMAIN HINTS AT A BRIEF PERIOD
OF PRECIPITATION PRODUCTION ACROSS THE CENTRAL PLAINS ON SUNDAY AS
TROPOSPHERIC MOISTURE AND UPPER TROPOSPHERIC THERMAL ADVECTION
INCREASES AHEAD OF THE APPROACHING TROUGH AXIS. QPF FIELDS FROM THE
NAM...OPERATIONAL GFS...EC AND SREF-MEAN ALL CONTINUE TO SUGGEST
LIGHT PRECIPITATION WILL BE REALIZED ACROSS PORTIONS OF OUR CWA ON
SUNDAY AND AS A RESULT...CONTINUED WITH POPS...ALBEIT LOW...ACROSS
MUCH OF THE AREA ON SUNDAY. UNFORTUNATELY PRECIPITATION TYPE REMAINS
QUESTIONABLE AS FORECAST PROXIMITY SOUNDINGS FROM ACROSS THE
CWA...PER THE NAM AND OPERATIONAL GFS...SUGGEST AN ELEVATED WARM
LAYER WILL LIKELY PROVIDE LIQUID PRECIPITATION WHILE SURFACE
TEMPERATURE READINGS FALL TO NEAR OR BELOW FREEZING AROUND DAYBREAK
SUNDAY. PREVIOUS SHIFT WENT AHEAD AND INSERTED A MENTION OF LIGHT
FREEZING RAIN FOR A TIME SUNDAY MORNING AND AT THIS TIME...SEE NO
REASON TO REMOVE THIS WORDING. GIVEN ALL THIS...A SLIGHT CHANCE FOR
LIGHT FREEZING RAIN REMAINS IN THE FORECAST FOR MUCH OF THE AREA FOR
A FEW HOURS SUNDAY MORNING AROUND DAYBREAK...WITH LIGHT RAIN THEN
FORECAST BY 14Z AS SURFACE TEMPERATURE READINGS CLIMB ABOVE FREEZING.
THERE MAY ALSO BE A PERIOD OF LIGHT DRIZZLE OR LIGHT FREEZING
DRIZZLE ACROSS PORTIONS OF THE CWA SUNDAY MORNING...WITH GUIDANCE
SUGGESTING 0-1KM RELATIVE HUMIDITY VALUES NEAR 100% WILL ACCOMPANY 0-
1KM BULK SHEAR VALUES OF 25-30KTS. GIVEN THE POTENTIAL FOR A
SATURATED LOWER TROPOSPHERE AS WELL AS SUFFICIENT TURBULENT
MIXING...OPTED TO KEEP A MENTION OF LIGHT DRIZZLE AND LIGHT FREEZING
DRIZZLE GOING IN THE FORECAST FOR SUNDAY MORNING.
AN OVERALL LACK IN OMEGA SHOULD THEN KEEP US DRY THROUGH MUCH OF THE
REST OF THE LONG-TERM FORECAST PERIOD...ALTHOUGH THERE ARE HINTS OF
AN UPPER TROPOSPHERIC SHORT WAVE PERHAPS BRINGING A ROUND OF LIGHT
PRECIPITATION TO THE REGION ON FRIDAY AND AS A RESULT...WENT WITH A
LOW POP ACROSS PORTIONS OF THE CWA ON FRIDAY.
LITTLE IF ANY CHANGE IN BOUNDARY-LAYER AIR MASS SHOULD PRESENT
SIMILAR TEMPERATURE READINGS FROM DAY TO DAY DURING THE LONG-TERM
FORECAST PERIOD...WITH HIGHS IN THE UPPER 40S TO MID 50S AND LOW IN
THE UPPER 20S TO LOWER 30S CURRENTLY FORECAST FOR THE MOST PART.
&&
.AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1129 PM CST FRI DEC 5 2014
FOR THE MOST PART...QUIET WEATHER IS EXPECTED DURING THE TAF
PERIOD. THAT BEING SAID...THERE IS A CONCERN THAT THE
TERMINALS...KGRI IN PARTICULAR...MAY BE ON THE EDGE OF STRATUS
WORKING WESTWARD AND IF LOW CLOUDS MAKE IT THIS FAR WEST...THEN
FOG MAY OCCUR ON THE EDGE OF THE STRATUS. AGAIN TOWARD THE END OF
THE TAF PERIOD...IN RETURN FLOW...LLVL MOISTURE WILL WORK TO THE
NORTH AND WEST AGAIN AND WILL NEED TO MONITOR FOR LOW CLOUD AND
FOG POTENTIAL.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...NOAA/NWS/MORITZ
LONG TERM...BRYANT
AVIATION...FAY
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1145 PM CST FRI DEC 5 2014
.SYNOPSIS...
ISSUED AT 322 PM CST FRI DEC 5 2014
WEAK COLD FRONT STALLING NEAR THE KS/NEB BORDER THIS AFTERNOON.
MOSTLY SUNNY SKIES AND SOME 10 TO 15 MPH NORTHERLY WINDS BEHIND THE
FRONT HAVE ALLOWED FOR GOOD MIXING WITH TEMPERATURES IN THE UPPER
40S AND 50S. MEANWHILE HIGH PRESSURE IS SETTLING ACROSS THE NORTHERN
PLAINS.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 322 PM CST FRI DEC 5 2014
TONIGHT HIGH PRESSURE WILL CONTINUE TO DRIFT ACROSS THE NORTHERN
PLAINS. THIS WILL CAUSE THE WINDS TO BECOME EASTERLY/SOUTHEASTERLY.
THIS WIND SWITCH WILL HELP TO USHER IN SOME LL MOISTURE. THIS WILL
COMBINE WITH MOSTLY CLEAR SKIES AND GOOD RADIATIONAL COOLING TO
PRODUCE LOWS IN THE TEENS AND MAYBE SOME PATCHY FOG. SOME CONCERNS
TOWARDS THE FOG DEVELOPMENT AS AFTERNOON TEMPS IN THE 50S MIXED THE
MOISTURE FAIRLY WELL. ALSO A VERY DRY SURFACE...LITTLE RAIN OVER THE
LAST MONTH ACROSS MOST OF THE AREA. THE NAM IS THE ONLY MODEL
SUGGESTING DEVELOPMENT...ALTHOUGH IT IS A LITTLE HIGH WITH CURRENT
DEW PTS. THE RUC IS LESS FAVORABLE...BUT IS CLOSER BUT IS A DEGREE
OR SO TO LOW WITH DEW PTS. THUS THE FORECAST DOES INCLUDE SOME
PATCHY FOG IN THE PLATTE RIVER VALLEY...WHICH IS LIKELY THE FIRST
PLACE FOR DEVELOPMENT ALTHOUGH CONFIDENCE IS LOW. HAVE ALSO INCLUDED
SOME FOG ACROSS THE FAR NORTHWEST...HOWEVER THERE IS BETTER GROUND
MOISTURE.
TOMORROW COOL HIGH PRESSURE CENTERED OVER MINNESOTA...HOWEVER WILL
SEE SOME COOLER TEMPS ALOFT /850 MB TEMPS AROUND 5C/ INTO THE HIGH
PLAINS. WILL KEEP TEMPS ABOUT 5 TO 10 DEGREES COOLER THAN TODAY.
LATELY THE WARMER MAV HAS BEEN CLOSER TO REALITY AND FAVORED THESE
WARMER NUMBERS FOR TOMORROW.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 322 PM CST FRI DEC 5 2014
...ABOVE NORMAL TEMPERATURES AND DRY CONDITIONS FORECAST SUNDAY
THROUGH FRIDAY...
MID RANGE PERIODS (SATURDAY NIGHT THROUGH MONDAY)...
THE UPPER TROUGH EXITING THE ROCKIES WILL MOVE ACROSS WESTERN
NEBRASKA SATURDAY NIGHT INTO SUNDAY. WHILE MOISTURE WILL BE AMPLE
FROM H7 TO H5...H85 TO H7 RELATIVELY DRY. CONCERN LIES IN
SATURATED LAYER BELOW 875 MB. WITH WEAK OMEGA PRESENT ALONG WITH
SUPERCOOLED DROPLETS OF -1C TO -3C...INTRODUCED PATCHY FREEZING
FRIZZLE WHICH IS POSSIBLE FROM 09Z TO 15Z SUNDAY. SURFACE
TEMPERATURES DURING THIS TIME SHOULD RANGE FROM 28 TO 32 DEGREES.
THE AREA MAY AFFECT SOUTHEASTERN AREAS MAINLY EAST OF A CURTIS
THROUGH CALLAWAY AND STUART LINE. OTHERWISE CLEARING SKIES FROM
WEST TO EAST ON SUNDAY WITH ANOTHER NICE WARMUP. DOWNSLOPING WEST
TO NORTHWEST WINDS 5 TO 15 MPH SHOULD PUSH HIGHS UP INTO THE LOWER
TO MID 50S...EXCEPT COOLER UPPER 40S NEAR ONEILL AND BARTLETT. A
WEAK COLD FRONT SUNDAY NIGHT. HIGHS MONDAY HOWEVER WILL REMAIN
VERY SIMILAR TO SUNDAY.
EXTENDED PERIODS (MONDAY NIGHT THROUGH FRIDAY)...
THE MILD CONDITIONS WILL PERSIST IN THE EXTENDED PERIODS AS UPPER
RIDGING DOMINATES THE CENTRAL CONUS. INCREASED TROUGHING ONTO THE
WEST COAST WILL ALSO HELP TO AMPLIFY DOWNSTREAM RIDGE.
UPPER RIDGING WILL BUILD INTO THE CENTRAL CONUS WEDNESDAY THROUGH
FRIDAY WITH HIGHS IN THE 50S. SOME HIGHS IN THE WEST COULD EXCEED
60 DEGREES WEDNESDAY AND BEYOND. BY FRIDAY...A STRONG UPPER
TROUGH WILL MOVE ONTO THE WEST COAST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1145 PM CST FRI DEC 5 2014
EXPECT MAINLY CLEAR SKIES OVERNIGHT ACROSS WESTERN AND NORTH
CENTRAL NEBRASKA. SOME PATCHY FOG IS POSSIBLE IN THE PLATTE RIVER
VALLEY TOWARD MORNING. VISBYS AT THE KLBF TERMINAL MAY DROP DOWN
TO 3SM AROUND 12Z SATURDAY. DURING THE DAY ON SATURDAY...HIGH
CLOUDS WILL BEGIN TO INCREASE ACROSS WESTERN AND NORTH CENTRAL
NEBRASKA AS A STORM SYSTEM MOVES INTO THE SOUTHWESTERN UNITED
STATES. BROKEN CIGS AROUND 20000 FT AGL ARE LIKELY AROUND 00Z
SUNDAY...WITH OVERCAST CIGS AROUND 10000 FT AGL EXPECTED FROM 00Z
TO 06Z SUNDAY. WINDS WILL BE FROM THE SOUTH OR SOUTHEAST AT AROUND
10 KTS ON SATURDAY.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MASEK
SHORT TERM...MASEK
LONG TERM...ROBERG
AVIATION...CLB
AREA FORECAST DISCUSSION
NWS BUFFALO NY
705 AM EST SAT DEC 6 2014
.SYNOPSIS...
LOW PRESSURE PASSING TO THE SOUTH OF THE REGION WILL BRING RAIN
WHICH WILL TAPER OFF FROM WEST TO EAST THIS AFTERNOON. HIGH PRESSURE
WILL THEN BUILD ACROSS THE REGION SUNDAY AND MONDAY WITH FAIR BUT
CHILLY WEATHER. LOW PRESSURE DEVELOPING ACROSS NEW ENGLAND IS LIKELY
TO BRING RAIN OR SNOW TO OUR REGION ON TUESDAY AND WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AT 700 AM...REGIONAL RADAR IMAGERY SHOWS A LARGE AREA OF
PRECIPITATION ACROSS MOST OF THE CWA...WITH THE ONLY DRY AREAS
NORTH OF A IAG-ART LINE. THERE WILL CONTINUE TO BE A SHARP CUT OFF
ON THE BACK OF THE SYSTEM...WITH AREAS NORTH OF NIAGARA FALLS TO
WATERTOWN LIKELY TO STAY DRY WHILE EVERYWHERE ELSE GETS A SOAKING
RAIN. IN TERMS OF MODEL GUIDANCE...THE HRRR IS IN LINE WITH MODEL
CONSENSUS AND PAINTS A PRETTY REASONABLE PICTURE OF HOW THE EVENT
IS LIKELY TO PLAY OUT. PRECIPITATION WILL TAPER OFF FROM WEST TO
EAST THIS AFTERNOON. THIS WILL BRING A DECENT AMOUNT OF RAIN TO
THE SOUTHERN TIER WITH A CONSENSUS OF HIGH-RES GUIDANCE BRINGING
HALF TO THREE-QUARTERS OF AN INCH OF RAIN. AMOUNTS WILL TAPER OFF
ABRUPTLY NORTH OF THIS...WITH BARELY MEASURABLE AMOUNTS NW OF
IAG/ART.
AS FOR PRECIPITATION TYPE...TEMPERATURES ARE ABOVE FREEZING IN MOST
AREAS WITH ONLY HIGHER TERRAIN IN LEWIS COUNTY STILL BELOW
FREEZING WHERE A WINTER WEATHER ADVISORY REMAINS IN PLACE.
ELSEWHERE...PRECIPITATION WILL FALL AS RAIN THROUGH THIS MORNING. COLDER
AIR (BOTH SURFACE AND ALOFT) WILL BUILD IN WHEN THE LOW PASSES TO
THE SOUTH AND SHIFTS WINDS TO THE NORTH THIS AFTERNOON. HOWEVER...THIS
WILL ONLY LEAVE A NARROW MARGIN FOR SNOW JUST AS PRECIPITATION IS
TAPERING OFF. LITTLE...IF ANY...ACCUMULATION IS EXPECTED BEFORE
PRECIPITATION ENDS.
THERE WILL ALSO BE AREAS OF FOG THIS MORNING...ESPECIALLY ACROSS
HIGHER TERRAIN IN THE SOUTHERN TIER.
HIGH PRESSURE WILL BUILD ACROSS THE UPPER LAKES THIS EVENING...THEN
GRADUALLY SHIFT INTO ONTARIO AND QUEBEC LATE TONIGHT. THIS WILL
BRING COOLER AND DRIER AIR INTO THE REGION TONIGHT. THE NORTHERLY
FLOW ACROSS THE LAKES MAY INITIALLY DELAY CLEARING...BUT WITH 850MB
TEMPERATURES ONLY -6C...LAKE INDUCED INSTABILITY WILL BE TOO SMALL TO
SUPPORT LAKE EFFECT PRECIPITATION AND MARGINAL TO RESULT IN LAKE
EFFECT CLOUDS. EXPECT CLOUDS TO LINGER THIS EVENING IN UPSLOPE
LOCATIONS...BUT EVENTUALLY SCATTER OUT LATE TONIGHT. EARLIER
CLEARING SHOULD ALLOW FOR LOWS 10 TO 15 EAST OF LAKE ONTARIO...WITH
UPPER TEENS TO LOWER 20S ELSEWHERE. THERE IS A SMALL CHANCE FOR
BLACK ICE IN SPOTS TONIGHT...BUT IT APPEARS WINDS LATE THIS
AFTERNOON AND EARLY EVENING SHOULD HELP DRY OUT ROADS IN MANY AREAS
BEFORE TEMPERATURES DROP BELOW FREEZING.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY/...
FAIR WEATHER IS EXPECTED SUNDAY THROUGH MONDAY NIGHT AS AN AREA OF
HIGH PRESSURE CROSSES SOUTHERN CANADA. THIS HIGH PRESSURE...STARTING
SUNDAY MORNING TO OUR WEST WILL BRING A LIGHT AND COOL NORTHERLY
FLOW ACROSS NEW YORK STATE. THOUGH A GOOD DEAL OF SUNSHINE IS
EXPECTED...THESE COOL NORTHERLY WINDS WILL KEEP MOST AREAS IN THE
20S THROUGH THE DAY. SUNDAY NIGHT OUR WINDS WILL VEER AROUND TO
EASTERLY AND THEN SOUTHEASTERLY ON MONDAY BEHIND THE BUBBLE OF HIGH
PRESSURE. A SEASONABLY COOL SUNDAY NIGHT WILL WARM TO THE MID 30S TO
LOWER 40S ACROSS THE REGION MONDAY WITH THE VEERING WINDS. AS
SOUTHERLY FLOW ALOFT INCREASES THROUGH THE DAY MONDAY EXPECT CLOUDS
TO THICKEN THROUGH THE DAY. A TIGHTENING PRESSURE GRADIENT BETWEEN
THE COOLER HIGH PRESSURE AIRMASS TO OUR SOUTHEAST AND A WARMING
AIRMASS AHEAD OF AN AREA OF LOW PRESSURE OVER THE WESTERN GREAT
LAKES WILL BRING A GUSTY BREEZE ACROSS THE WESTERN AND CENTRAL PART
OF NEW YORK STATE. SOUTHEAST WINDS MAY REACH GUSTS 25 TO 35
MPH...AND POSSIBLY NEAR 40 MPH ALONG THE LAKE ERIE SHORELINE.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AN INTERESTING WEATHER SYSTEM IS STILL ON TRACK TO EVOLVE MONDAY
NIGHT THROUGH WEDNESDAY. GLOBAL MODELS CONTINUE TO STRUGGLE WITH THE
FAIRLY COMPLEX EVOLUTION OF THIS SYSTEM. TO APPRECIATE THE
COMPLEXITY...THIS SYSTEM IS EXPECTED TO EVOLVE OUT OF A PACIFIC
SHORTWAVE CURRENTLY COMING ON SHORE IN THE PAC NORTHWEST ANOTHER
WEAK SOUTHERN STREAM SHORTWAVE NEAR SOUTHERN CALIFORNIA AND A HIGH
LATITUDE WAVE THAT IS PROGGED TO PHASE WITH BOTH SHORTWAVES OVER THE
NORTHEAST CONUS. MODEL TRENDS TODAY HAVE BEEN TOWARD CUTTING OFF AN
UPPER-LEVEL LOW OVER NEW ENGLAND RATHER THAN MAINTAINING AN OPEN
WAVE. HOWEVER...THIS IS WHERE THE SIMILARITIES IN THE MODELS END.
WHILE THE GFS HAS CAUGHT ONTO THE ECMWF TREND OF CUTTING OFF THE
LOW...IT REMAINS A FARTHER NORTH SOLUTION...WITH THE LOW CENTERED
OVER SOUTHERN CANADA JUST NORTH OF VERMONT BY WEDNESDAY MORNING. THE
FARTHER SOUTH ECMWF SOLUTION ACTUALLY CENTERS THE LOW OVER NEW
JERSEY BY WEDNESDAY MORNING. GIVEN THE CUT-OFF NATURE OF THIS
LOW...NEITHER SOLUTION CONTAINS SIGNIFICANT AMOUNTS OF COLD
AIR...BUT THE GFS REMAINS ON THE COOLER SIDE WITH 850MB TEMPS AROUND
-10 TO -12 C...COMPARED TO THE EC WHICH IS AROUND -6 TO -8 C.
SO WHAT DOES THIS ALL MEAN FOR THE FORECAST? THE OVERALL TREND HAS
BEEN TOWARD A WETTER SOLUTION FOR THE FORECAST AREA...AND THUS HAVE
INCREASED POPS TO LIKELY TUESDAY AND TUESDAY NIGHT. PRECIPITATION
WOULD LIKELY START AS EITHER RAIN OR A RAIN/SNOW MIX MONDAY
NIGHT...AND REMAINING A RAIN/SNOW MIX THROUGH THE DAY TUESDAY. THEN
WITH COOLER TEMPERATURES FILTERING INTO THE FORECAST AREA TUESDAY
INTO TUESDAY NIGHT MIXED PRECIPITATION SHOULD CHANGE OVER TO SNOW
WITH PERHAPS SOME LAKE ENHANCEMENT IF THE COLDER GFS SOLUTION
VERIFIES. BY WEDNESDAY A COOL...BRISK NORTHWEST FLOW WILL AGAIN KEEP
LIKELY SNOW SHOWERS ACROSS THE REGION...ESPECIALLY ACROSS THE
UPSLOPE HILLS OF SW NYS AND EASTERN LAKE ONTARIO REGION. WILL RAISE
POPS TO LIKELY HERE...AND SLOWLY TAPERING THEM OFF TO JUST CHANCE
POPS THURSDAY AS THE COMPLEX AREA OF LOW PRESSURE EXITS EASTWARD.
WEDNESDAY AND THURSDAY TEMPERATURES SHOULD AVERAGE JUST BELOW NORMAL
WITH THE COOL NW FLOW.
TIMING DIFFERENCES REMAIN ON HOW QUICKLY THE CUT OFF LOW WILL MOVE
EASTWARD WITH THE EC HOLDING THE LOW BACK THE LONGEST...AND THUS
DELAYING THE ONSET OF WARMER TEMPERATURES UNTIL THE START OF THE
FOLLOWING WEEK. THE GFS HOWEVER MOVES THE LOW OUT MORE QUICKLY...AND
THE AMPLIFYING PATTERN ACROSS THE CONUS WOULD RESULT IN MILD
TEMPERATURES ACROSS THE FORECAST AREA BY THE WEEKEND.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AT 12Z...LOW PRESSURE WAS TRACKING TO THE SOUTH OF THE
REGION...BRINGING WIDESPREAD RAIN TO AREAS SOUTH OF IAG/ART. CIGS
HAVE LOWERED CONSIDERABLY WITH A MIX OF MVFR AND IFR CONDITIONS IN
MOST AREAS. A SHIFT TO NORTHERLY WINDS SHOULD CAUSE CIGS TO
LOWER...WITH FAIRLY WIDESPREAD IFR CONDITIONS EXPECTED. EVEN LOWER
MOISTURE AND FOG IS EXPECTED ACROSS HIGHER TERRAIN SUCH AS
JHW. DRIER AIR WILL BUILD IN BEHIND THE LOW...FOLLOWED BY SURFACE
HIGH PRESSURE TONIGHT. IFR CIGS WILL GRADUALLY LIFT THIS
AFTERNOON...EVENTUALLY RETURNING TO VFR TONIGHT AS DRIER AIR
BUILDS IN TONIGHT.
OUTLOOK...
SUNDAY AND MONDAY...MAINLY VFR.
TUESDAY AND WEDNESDAY...MVFR WITH RAIN OR SNOW LIKELY.
&&
.MARINE...
WINDS WILL SHIFT TO THE NORTH ONCE LOW PRESSURE PASSES TO OUR SOUTH
TODAY. THIS WILL REQUIRE SMALL CRAFT ADVISORIES ON THE SOUTH SHORES
OF LAKE ONTARIO LATE TODAY THROUGH EARLY SUNDAY. HAVE ALSO ADDED
SMALL CRAFT ADVISORIES TO LAKE ERIE SOUTH OF DUNKIRK...WHERE THE 15
TO 20 KT FLOW SHOULD BE AMPLE TO BUILD WAVES TO 5 FT. HIGH PRESSURE
WILL BUILD IN ON SUNDAY.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR NYZ008.
MARINE...SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 7 AM EST
SUNDAY FOR LEZ040.
SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 10 AM
EST SUNDAY FOR LOZ043-044.
SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 7 AM EST
SUNDAY FOR LOZ042.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL
SHORT TERM...THOMAS
LONG TERM...CHURCH/THOMAS
AVIATION...APFFEL
MARINE...APFFEL/THOMAS
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1251 AM EST SAT DEC 6 2014
.SYNOPSIS...
LOW PRESSURE WILL PASS JUST SOUTH OF THE REGION TONIGHT INTO
SATURDAY WITH MODERATING TEMPERATURES AND WIDESPREAD LIGHT MIXED
PRECIPITATION EXPECTED. COLDER AND DRIER WEATHER RETURNS BEHIND THIS
SYSTEM BY SATURDAY NIGHT AND PERSISTS INTO MONDAY AS CANADIAN HIGH
PRESSURE BRIDGES ACROSS THE NORTHEAST. BY THE MIDDLE OF NEXT
WEEK...THERE IS INCREASING CONFIDENCE THAT A SIGNIFICANT WINTER
STORM MAY AFFECT THE REGION WITH MODERATE TO HEAVY RAIN AND SNOW.
&&
.NEAR TERM /UNTIL 7 AM THIS MORNING/...
AS OF 1233 AM EST SATURDAY...CURRENT FORECAST LOOKS TO BE ON
TRACK WITH ONLY CHANGE BEING TO BLEND IN CURRENT OBSERVATIONS.
LIGHT SNOW HAS BEGUN IN NORTHERN AND CENTRAL VT BUT THE STEADIEST
AREAS OF LIGHT SNOW HAS BEEN ACROSS SOUTHERN VT INTO ESSEX COUNTY
NY. ASSESSMENT OF KENX DUAL-POL DATA AND RAP THERMAL PROGS SUGGEST
MELTING LAYER ROUGHLY EXTENDS FROM NORTHWEST MA UP TO THE NORTH
SIDE OF THE ALBANY METRO THEN EASTWARD ALONG I-90. SO STILL SOME
TIME FOR SNOW TO ACCUMULATE FURTHER BEFORE AFOREMENTIONED WARM
NOSE LIFTS NORTH AND PRECIPITATION BECOMES MORE OF A MIX OF
SNOW...SLEET AND FREEZING RAIN. THIS IS ALREADY CAPTURED WELL IN
GOING FORECAST SO NO CHANGES TO THE WINTER WEATHER ADVISORY AT
THIS TIME.
PREVIOUS NEAR-TERM DISCUSSION ISSUED AT 1020 PM EST FRIDAY
FOLLOWS...
LIGHT PRECIPITATION IS RATHER WIDESPREAD ACROSS VERMONT THIS
EVENING. PRECIPITATION IS MOSTLY IN THE FORM OF SNOW...WITH A FEW
POCKETS OF FREEZING RAIN/FREEZING DRIZZLE. ACROSS NORTHERN NEW
YORK...SPOTTY COVERAGE OF PRECIPITATION WITH SOME AREAS OF LIGHT
SNOW OR MIXED PRECIPITATION. NO SIGNIFICANT CHANGES TO GOING
FORECAST...JUST A FEW ADJUSTMENTS TO POPS AND WEATHER OVER NEXT
FEW HOURS TO REFLECT LATEST CONDITIONS AND TRENDS. THERMAL
PROFILES STILL INDICATE LIGHT SNOW TURNS TO A WINTRY MIX
OVERNIGHT...AND TO RAIN IN SOME AREAS. HIGHEST POPS FOR THE
OVERNIGHT PERIOD ACROSS CENTRAL AND SOUTHERN SECTIONS OF VERMONT
WITH LOWEST POPS ACROSS SAINT LAWRENCE VALLEY. GOING FORECAST HAS
ALL OF THIS WELL COVERED. ALSO...NO CHANGES TO WINTER WEATHER
ADVISORIES WHICH ARE IN EFFECT FOR MUCH OF VERMONT OUTSIDE OF
CHAMPLAIN VALLEY AND PART OF ESSEX COUNTY NY. LOOK FOR A FEW
INCHES OF SNOW WITH LIGHT ICE ACCUMULATION.
EARLIER DISCUSSION...
FORECAST REMAINS MORE OR LESS ON TRACK FOR TONIGHT AS CLOUDS
CONTINUE TO THICKEN AND LOWER AS DEEP WARM THERMAL ADVECTION
OVERSPREADS THE REGION FROM THE SOUTH AND WEST. PRECIPITATION SEEN
ON RADAR LATE THIS AFTERNOON ACROSS EASTERN PORTIONS OF NY STATE
IS MAINLY IN VIRGA FORM...BUT STEADIER LIGHT PRECIPITATION STILL
ON TRACK TO ARRIVE LATER THIS EVENING/TONIGHT AS LEAD SURFACE WAVE
TRACKS ENE FROM THE OHIO VALLEY. LEANED TOWARD GFS THERMAL
PROFILES AS NAM SHOWING ITS TYPICAL COLDER BIAS ALOFT. LATEST CAM
TRENDS ALSO SUGGEST BULK OF STEADIER PRECIPITATION TO AFFECT AREAS
GENERALLY ALONG AND SOUTH OF A KART- KSLK-KBTV-K1V4 LINE LATER
TONIGHT WITH FAR NORTHERN COUNTIES SEEING ONLY SCT LIGHT
PRECIPITATION AT BEST. THAT SAID...I`M STILL EXPECTING A PERIOD OF
SHSN/LIGHT SNOWS TO OVERSPREAD A GOOD PORTION OF THE AREA LATER
THIS EVENING/TONIGHT BEFORE PRECIPITATION TRANSITIONS TO A MIX OF
PL/FZRA...ESP ACROSS EASTERN PORTIONS OF VT SOUTH OF ROUTE 2 OR
SO. ELSEWHERE...ESP IN THE CHAMPLAIN VALLEY AND ADIRONDACKS...MIX
WITH PL/FZRA SHOULD BE RELATIVELY BRIEF BEFORE TRANSITION TO LIGHT
RAIN GIVEN SOUTHERLY FLOW WILL CONTINUE TO WARM THE NEAR SFC
LAYERS. THUS MORE MINIMAL IMPACTS IN THESE LOCATIONS DESPITE ROADS
POSSIBLY BEING A LITTLE SLICK BY MORNING. TEMPERATURES TO REMAIN
STEADY OR SLOWLY RISE OVERNIGHT...MOST PRONOUNCED FROM THE WESTERN
SLOPES WEST ACROSS THE CHAMPLAIN VALLEY INTO OUR NRN NY COUNTIES.
SNOWFALL AMOUNTS BY SATURDAY MORNING GENERALLY A DUSTING TO 2
INCHES CHAMPLAIN VALLEY...A GOOD PORTION OF THE NRN ADIRONDACKS
AND SAINT LAWRENCE VALLEY. IN CURRENT WINTER WEATHER ADVISORY
AREA...1-3 INCHES OF SNOW EXPECTED ACROSS THE HIGH PEAKS REGION
AND MUCH OF VERMONT EAST OF THE GREENS WHERE THERMAL PROFILES WILL
BE SLIGHTLY COLDER. LOCALIZED HIGHER AMOUNTS...2-4 INCHES OR SO
POSSIBLE ACROSS PORTIONS OF NC/NE VT. AGAIN...SOME LIGHT TO TRACE
AMOUNTS OF ICE WILL ALSO BE POSSIBLE IN THESE AREAS
&&
.SHORT TERM /7 AM THIS MORNING THROUGH SUNDAY NIGHT/...
AS OF 326 PM EST FRIDAY...BY TOMORROW WIDESPREAD LIGHT TO
MODERATE PRECIPITATION CONTINUES AS SECONDARY AND MORE ROBUST SFC
WAVE RIDES ACROSS THE NORTHERN MID-ATLANTIC INTO SOUTHERN NEW
ENGLAND. THERMAL PROFILES CONTINUE TO SLOWLY WARM SUCH THAT MOST
AREAS EXCEPT THE FAR NORTH/NORTHWEST SHOULD FULLY TRANSITION TO
LIGHT RAIN BY MID TO LATE MORNING WITH PERHAPS A FEW POCKETS OF
LIGHT FZRA LINGERING ACROSS SHELTERED ERN VT HOLLOWS THROUGH NOON
OR SO. MODELS FAIRLY CONSISTENT IN SHOWING A RATHER SHARP CUTOFF
IN STEADIER PRECIPITATION NORTH AND WEST OF A KSLK-KBTV-KNPT LINE
TOMORROW. SO AREAS ACROSS FAR NW VT INTO FAR NRN NY/SAINT LAWRENCE
VALLEY STEADIER PRECIPITATION LESS LIKELY.
BY LATER IN THE AFTERNOON INTO EARLY EVENING THE APPROACH OF A
MODESTLY STRONG NORTHERN STREAM UPPER TROUGH WILL PUSH A COLD FRONT
THROUGH THE REGION WITH STEADIER PRECIPITATION EXITING SOUTH AND
EAST OVER TIME. AS POST-FRONTAL FLOW TRENDS
NORTH/NORTHWESTERLY...PRECIPITATION SHOULD TRANSITION BACK TO A
PERIOD OF LIGHT SNOW/SHSN FOR A FEW HOURS BEFORE ENDING AS DRIER
AIR FILTERS INTO THE REGION. THUS AN ADDITIONAL BACKSIDE D-2"
SNOWFALL WILL BE POSSIBLE IN THE 21-03Z TIME FRAME.
THEREAFTER...COLD FRONT EXITS SOUTHEAST OVERNIGHT SATURDAY AS
ANOMALOUSLY STRONG 1045 MB CANADIAN POLAR HIGH BUILDS ACROSS THE
REGION BY SUNDAY/SUNDAY NIGHT ON DIMINISHING NORTHWESTERLY FLOW.
THUS THE IDEA OF GRADUAL CLEARING FROM NORTHWEST TO SOUTHEAST
SATURDAY EVENING LOOKS ON TRACK AS TEMPERATURES TREND BACK TOWARD
SEASONALLY COLD VALUES. INDEED...AS HIGH CRESTS ATOP THE REGION
SUNDAY NIGHT WIDESPREAD VALUES IN THE SINGLE DIGITS ABOVE/BELOW ZERO
LOOK QUITE REALISTIC AS LIGHT WINDS/CLEAR SKIES LEAD TO OPTIMAL
LONGWAVE RADIATIVE PROCESSES.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 326 PM EST FRIDAY...DRY WEATHER IS EXPECTED THROUGH MONDAY
NIGHT AS A DOME OF HIGH PRESSURE CONTINUES BUILDING INTO THE AREA.
BY TUESDAY MORNING THE UPPER LEVEL TROUGH WILL DIG INTO THE GREAT
LAKES AND PUSH THE HIGH PRESSURE WELL OFF TO THE NORTHEAST OVER
NEWFOUNDLAND OPENING THE REGION UP FOR A EITHER A COASTAL LOW OR A
SHORTWAVE WITH THE UPPER LEVEL TROUGH DEPENDING ON THE MODEL TO
PUSH INTO THE REGION. RIGHT NOW THE GFS IS THE LONE LONG RANGE
MODEL WITH THE SHORT WAVE SOLUTION. THE ECMWF IS MUCH MORE ALIGNED
WITH THE UKMET, CANADIAN AND DGEX IN BRINGING IN A COASTAL LOW UP
THE EAST COAST THEN PHASING JUST OFF THE COAST OF NEW JERSEY. AS
THE PHASING OCCURS THERE IS AN INCREASING CHANCE OF RAIN/SNOW
SHOWER ON WEDNESDAY. THE OCCLUDED LOW REDEVELOPS JUST OFF OF CAPE
COD WHICH COULD BRING THE PORTIONS OF THE AREA HEAVY SNOWFALL AS
THE WINDS SHIFT AROUND AND DEVELOP A MORE NORTHERLY COMPONENT.
WITH HIGH PRESSURE TO THE NORTHWEST NEAR LAKE SUPERIOR A STRONG
PRESSURE GRADIENT WILL BRING STRONG NORTHEASTERLY WINDS ON
WEDNESDAY SHIFTING TO NORTHERLY BY THURSDAY. RIGHT NOW THE
FORECAST IS A BLEND OF THE MODELS WITH LIKELY RAIN/SNOW SHOWERS ON
TUESDAY WITH A CHANCE OF SNOW SHOWERS ON THURSDAY AS WE GET HIT BY
THE BACK SIDE OF THE LOW. MAX TEMPS WILL BE FOR THE MOST PART NEAR
NORMAL WITH MIN TEMPS RUNNING A FEW DEGREES ABOVE NORMAL.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
THROUGH 06Z SUNDAY...MVFR/VFR CEILINGS AND VISIBILITIES WILL
CONTINUE EARLY THIS MORNING AS FIRST AREA OF PRECIPITATION MOVES
ACROSS THE AREA. THE PRECIPITATION WILL GENERALLY BE LIGHT...BUT
WILL BE A MIX OF SNOW...SLEET...AND FREEZING DRIZZLE. THE
PRECIPITATION SHOULD END BY 12Z...THEN A SECONDARY AREA OF
PRECIPITATION WILL MOVE UP FROM THE OHIO VALLEY AND BE IN THE FORM
OF RAIN AND SOME SNOW FROM MID-MORNING THROUGH EARLY EVENING. IT
WILL BE DURING THIS PERIOD THAT CEILINGS AND VISIBILITIES WILL
LOWER INTO THE MVFR AND IFR CATEGORIES. THE WINDS WILL BECOME
NORTHWEST BETWEEN 18Z AND 20Z AND THE PRECIPITATION WILL GRADUALLY
COME TO AN END BETWEEN 20Z AND 02Z. VISIBILITIES WILL IMPROVE INTO
THE VFR CATEGORY AT THIS TIME...BUT CEILINGS WILL REMAIN MVFR/IFR
FOR THE REMAINDER OF THE PERIOD.
OUTLOOK 06Z SUNDAY THROUGH WEDNESDAY...
06Z SUN - 12Z TUES: VFR...THOUGH A CHANCE OF MVFR DEVELOPING
DURING THE DAY MONDAY.
12Z TUES - 00Z THURS: MVFR EXPECTED WITH PERIODS OF IFR AS A
SYSTEM DEVELOPS AND BRINGS PERIODS OF PRECIPITATION.
&&
.MARINE...
A LAKE WIND ADVISORY IS IN EFFECT FOR TONIGHT. LOW LEVEL SOUTHERLY
JET OVER THE REGION OVERNIGHT...SO EXPECT SOUTH WINDS 15 TO 25
KTS. WAVE HEIGHTS WILL RANGE FROM 2 TO 4 FEET ON THE BROAD LAKE.
WINDS ARE EXPECTED TO DROP BELOW ADVISORY CRITERIA SATURDAY
MORNING AND THEN SHIFT INTO THE NORTH SATURDAY AFTERNOON WITH THE
PASSAGE OF A COLD FRONT.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR VTZ003-
004-006>008-010>012-016>019.
NY...WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR NYZ034.
&&
$$
SYNOPSIS...JMG
NEAR TERM...RJS/LOCONTO
SHORT TERM...JMG
LONG TERM...DEAL
AVIATION...EVENSON/DEAL
MARINE...WFO BTV
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1234 AM EST SAT DEC 6 2014
.SYNOPSIS...
LOW PRESSURE WILL PASS JUST SOUTH OF THE REGION TONIGHT INTO
SATURDAY WITH MODERATING TEMPERATURES AND WIDESPREAD LIGHT MIXED
PRECIPITATION EXPECTED. COLDER AND DRIER WEATHER RETURNS BEHIND THIS
SYSTEM BY SATURDAY NIGHT AND PERSISTS INTO MONDAY AS CANADIAN HIGH
PRESSURE BRIDGES ACROSS THE NORTHEAST. BY THE MIDDLE OF NEXT
WEEK...THERE IS INCREASING CONFIDENCE THAT A SIGNIFICANT WINTER
STORM MAY AFFECT THE REGION WITH MODERATE TO HEAVY RAIN AND SNOW.
&&
.NEAR TERM /UNTIL 7 AM THIS MORNING/...
AS OF 1233 AM EST SATURDAY...CURRENT FORECAST LOOKS TO BE ON
TRACK WITH ONLY CHANGE BEING TO BLEND IN CURRENT OBSERVATIONS.
LIGHT SNOW HAS BEGUN IN NORTHERN AND CENTRAL VT BUT THE STEADIEST
AREAS OF LIGHT SNOW HAS BEEN ACROSS SOUTHERN VT INTO ESSEX COUNTY
NY. ASSESSMENT OF KENX DUAL-POL DATA AND RAP THERMAL PROGS SUGGEST
MELTING LAYER ROUGHLY EXTENDS FROM NORTHWEST MA UP TO THE NORTH
SIDE OF THE ALBANY METRO THEN EASTWARD ALONG I-90. SO STILL SOME
TIME FOR SNOW TO ACCUMULATE FURTHER BEFORE AFOREMENTIONED WARM
NOSE LIFTS NORTH AND PRECIPITATION BECOMES MORE OF A MIX OF
SNOW...SLEET AND FREEZING RAIN. THIS IS ALREADY CAPTURED WELL IN
GOING FORECAST SO NO CHANGES TO THE WINTER WEATHER ADVISORY AT
THIS TIME.
PREVIOUS NEAR-TERM DISCUSSION ISSUED AT 1020 PM EST FRIDAY
FOLLOWS...
LIGHT PRECIPITATION IS RATHER WIDESPREAD ACROSS VERMONT THIS
EVENING. PRECIP IS MOSTLY IN THE FORM OF SNOW...WITH A FEW POCKETS
OF FREEZING RAIN/FREEZING DRIZZLE. ACROSS NORTHERN NEW
YORK...SPOTTY COVERAGE OF PRECIPITATION WITH SOME AREAS OF LIGHT
SNOW OR MIXED PRECIP. NO SIGNIFICANT CHANGES TO GOING
FORECAST...JUST A FEW ADJUSTMENTS TO POPS AND WX OVER NEXT FEW
HOURS TO REFLECT LATEST CONDITIONS AND TRENDS. THERMAL PROFILES
STILL INDICATE LIGHT SNOW TURNS TO A WINTRY MIX OVERNIGHT...AND TO
RAIN IN SOME AREAS. HIGHEST POPS FOR THE OVERNIGHT PERIOD ACROSS
CENTRAL AND SOUTHERN SECTIONS OF VERMONT WITH LOWEST POPS ACROSS
SAINT LAWRENCE VALLEY. GOING FORECAST HAS ALL OF THIS WELL
COVERED. ALSO...NO CHANGES TO WINTER WEATHER ADVISORIES WHICH ARE
IN EFFECT FOR MUCH OF VERMONT OUTSIDE OF CHAMPLAIN VALLEY AND PART
OF ESSEX COUNTY NY. LOOK FOR A FEW INCHES OF SNOW WITH LIGHT ICE
ACCUMULATION.
EARLIER DISCUSSION...
FORECAST REMAINS MORE OR LESS ON TRACK FOR TONIGHT AS CLOUDS
CONTINUE TO THICKEN AND LOWER AS DEEP WARM THERMAL ADVECTION
OVERSPREADS THE REGION FROM THE SOUTH AND WEST. PRECIPITATION SEEN
ON RADAR LATE THIS AFTERNOON ACROSS EASTERN PORTIONS OF NY STATE
IS MAINLY IN VIRGA FORM...BUT STEADIER LIGHT PCPN STILL ON TRACK
TO ARRIVE LATER THIS EVENING/TONIGHT AS LEAD SURFACE WAVE TRACKS
ENE FROM THE OHIO VALLEY. LEANED TOWARD GFS THERMAL PROFILES AS
NAM SHOWING ITS TYPICAL COLDER BIAS ALOFT. LATEST CAM TRENDS ALSO
SUGGEST BULK OF STEADIER PCPN TO AFFECT AREAS GENERALLY ALONG AND
SOUTH OF A KART- KSLK-KBTV-K1V4 LINE LATER TONIGHT WITH FAR
NORTHERN COUNTIES SEEING ONLY SCT LIGHT PCPN AT BEST. THAT
SAID...I`M STILL EXPECTING A PERIOD OF SHSN/LIGHT SNOWS TO
OVERSPREAD A GOOD PORTION OF THE AREA LATER THIS EVENING/TONIGHT
BEFORE PCPN TRANSITIONS TO A MIX OF PL/FZRA...ESP ACROSS EASTERN
PORTIONS OF VT SOUTH OF ROUTE 2 OR SO. ELSEWHERE...ESP IN THE
CHAMPLAIN VALLEY AND DACKS...MIX WITH PL/FZRA SHOULD BE RELATIVELY
BRIEF BEFORE TRANSITION TO LIGHT RAIN GIVEN SOUTHERLY FLOW WILL
CONTINUE TO WARM THE NEAR SFC LAYERS. THUS MORE MINIMAL IMPACTS IN
THESE LOCATIONS DESPITE ROADS POSSIBLY BEING A LITTLE SLICK BY
MORNING. TEMPERATURES TO REMAIN STEADY OR SLOWLY RISE
OVERNIGHT...MOST PRONOUNCED FROM THE WESTERN SLOPES WEST ACROSS
THE CHAMPLAIN VALLEY INTO OUR NRN NY COUNTIES. SNOWFALL AMOUNTS BY
SATURDAY MORNING GENERALLY A DUSTING TO 2 INCHES CHAMPLAIN
VALLEY...A GOOD PORTION OF THE NRN DACKS AND SLV. IN CURRENT
WINTER WX ADVISORY AREA...1-3 INCHES OF SNOW EXPECTED ACROSS THE
HIGH PEAKS REGION AND MUCH OF VERMONT EAST OF THE GREENS WHERE
THERMAL PROFILES WILL BE SLIGHTLY COLDER. LOCALIZED HIGHER
AMOUNTS...2-4 INCHES OR SO POSSIBLE ACROSS PORTIONS OF NC/NE VT.
AGAIN...SOME LIGHT TO TRACE AMOUNTS OF ICE WILL ALSO BE POSSIBLE
IN THESE AREAS
&&
.SHORT TERM /7 AM THIS MORNING THROUGH SUNDAY NIGHT/...
AS OF 326 PM EST FRIDAY...BY TOMORROW WIDESPREAD LIGHT TO
MODERATE PRECIPITATION CONTINUES AS SECONDARY AND MORE ROBUST SFC
WAVE RIDES ACROSS THE NORTHERN MID-ATLANTIC INTO SOUTHERN NEW
ENGLAND. THERMAL PROFILES CONTINUE TO SLOWLY WARM SUCH THAT MOST
AREAS EXCEPT THE FAR NORTH/NORTHWEST SHOULD FULLY TRANSITION TO
LIGHT RAIN BY MID TO LATE MORNING WITH PERHAPS A FEW POCKETS OF
LIGHT FZRA LINGERING ACROSS SHELTERED ERN VT HOLLOWS THROUGH NOON
OR SO. MODELS FAIRLY CONSISTENT IN SHOWING A RATHER SHARP CUTOFF
IN STEADIER PCPN NORTH AND WEST OF A KSLK-KBTV-KNPT LINE TOMORROW.
SO AREAS ACROSS FAR NW VT INTO FAR NRN NY/SLV STEADIER PCPN LESS
LIKELY.
BY LATER IN THE AFTERNOON INTO EARLY EVENING THE APPROACH OF A
MODESTLY STRONG NORTHERN STREAM UPPER TROUGH WILL PUSH A COLD FRONT
THROUGH THE REGION WITH STEADIER PCPN EXITING SOUTH AND EAST OVER
TIME. AS POST-FRONTAL FLOW TRENDS NORTH/NORTHWESTERLY...PCPN SHOULD
TRANSITION BACK TO A PERIOD OF LIGHT SNOW/SHSN FOR A FEW HOURS
BEFORE ENDING AS DRIER AIR FILTERS INTO THE REGION. THUS AN
ADDITIONAL BACKSIDE D-2" SNOWFALL WILL BE POSSIBLE IN THE 21-03Z
TIME FRAME.
THEREAFTER...COLD FRONT EXITS SOUTHEAST OVERNIGHT SATURDAY AS
ANOMALOUSLY STRONG 1045 MB CANADIAN POLAR HIGH BUILDS ACROSS THE
REGION BY SUNDAY/SUNDAY NIGHT ON DIMINISHING NORTHWESTERLY FLOW.
THUS THE IDEA OF GRADUAL CLEARING FROM NORTHWEST TO SOUTHEAST
SATURDAY EVENING LOOKS ON TRACK AS TEMPERATURES TREND BACK TOWARD
SEASONALLY COLD VALUES. INDEED...AS HIGH CRESTS ATOP THE REGION
SUNDAY NIGHT WIDESPREAD VALUES IN THE SINGLE DIGITS ABOVE/BELOW ZERO
LOOK QUITE REALISTIC AS LIGHT WINDS/CLR SKIES LEAD TO OPTIMAL
LONGWAVE RADIATIVE PROCESSES.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 326 PM EST FRIDAY...DRY WEATHER IS EXPECTED THROUGH MONDAY
NIGHT AS A DOME OF HIGH PRESSURE CONTINUES BUILDING INTO THE AREA.
BY TUESDAY MORNING THE UPPER LEVEL TROUGH WILL DIG INTO THE GREAT
LAKES AND PUSH THE HIGH PRESSURE WELL OFF TO THE NORTHEAST OVER
NEWFOUNDLAND OPENING THE REGION UP FOR A EITHER A COASTAL LOW OR A
SHORTWAVE WITH THE UPPER LEVEL TROUGH DEPENDING ON THE MODEL TO
PUSH INTO THE REGION. RIGHT NOW THE GFS IS THE LONE LONG RANGE
MODEL WITH THE SHORT WAVE SOLUTION. THE ECMWF IS MUCH MORE ALIGNED
WITH THE UKMET, CANADIAN AND DGEX IN BRINGING IN A COASTAL LOW UP
THE EAST COAST THEN PHASING JUST OFF THE COAST OF NEW JERSEY. AS
THE PHASING OCCURS THERE IS AN INCREASING CHANCE OF RAIN/SNOW
SHOWER ON WEDNESDAY. THE OCCLUDED LOW REDEVELOPS JUST OFF OF CAPE
COD WHICH COULD BRING THE PORTIONS OF THE AREA HEAVY SNOWFALL AS
THE WINDS SHIFT AROUND AND DEVELOP A MORE NORTHERLY COMPONENT.
WITH HIGH PRESSURE TO THE NORTHWEST NEAR LAKE SUPERIOR A STRONG
PRESSURE GRADIENT WILL BRING STRONG NORTHEASTERLY WINDS ON
WEDNESDAY SHIFTING TO NORTHERLY BY THURSDAY. RIGHT NOW THE
FORECAST IS A BLEND OF THE MODELS WITH LIKELY RAIN/SNOW SHOWERS ON
TUESDAY WITH A CHANCE OF SNOW SHOWERS ON THURSDAY AS WE GET HIT BY
THE BACK SIDE OF THE LOW. MAX TEMPS WILL BE FOR THE MOST PART NEAR
NORMAL WITH MIN TEMPS RUNNING A FEW DEGREES ABOVE NORMAL.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
THROUGH 00Z SUNDAY...A GENERAL DETERIORATION OF FLIGHT CONDITIONS
IS EXPECTED OVER THE NEXT 24 HOURS. ALL SITES START VFR THIS
EVENING WITH A FEW BRIEF REDUCTIONS TO MVFR IN LIGHT SNOW
SHOWERS/FLURRIES FOR THE FIRST COUPLE OF HOURS.
AFTERWARD...CEILINGS WILL LOWER TO MVFR AREA-WIDE AND AREAS OF
LIGHT MIXED PRECIPITATION WILL CONTINUE TO DEVELOP AND BRING
PERIODS OF REDUCED VISIBILITIES (MAINLY TO MVFR ALTHOUGH SOME IFR
POSSIBLE AT SLK). MOST SITES WILL CHANGE TO RAIN LATE
TONIGHT/EARLY SATURDAY MORNING. SOUTHERLY FLOW TONIGHT (EXCEPT
NORTHEAST AT MSS) WILL TURN NORTH/NORTHWESTERLY BY SATURDAY
AFTERNOON USHERING IN AN ADDITIONAL LOWERING OF CEILINGS AND A
CHANGE BACK OVER TO SNOW...THUS EXPECTING WIDESPREAD MVFR/IFR BY
LATE SATURDAY.
OUTLOOK 00Z SUNDAY THROUGH WEDNESDAY...
00Z SUN - 06Z SUN: MVFR/IFR IN LIGHT SNOW...GRADUALLY ENDING FROM
WEST TO EAST.
06Z SUN - 12Z TUES: VFR...THOUGH A CHANCE OF MVFR DEVELOPING
DURING THE DAY MONDAY.
12Z TUES - 00Z THURS: MVFR EXPECTED WITH PERIODS OF IFR AS A
SYSTEM DEVELOPS AND BRINGS PERIODS OF PRECIPITATION.
&&
.MARINE...
A LAKE WIND ADVISORY IS IN EFFECT FOR TONIGHT. LOW LEVEL SOUTHERLY
JET OVER THE REGION OVERNIGHT...SO EXPECT SOUTH WINDS 15 TO 25
KTS. WAVE HEIGHTS WILL RANGE FROM 2 TO 4 FEET ON THE BROAD LAKE.
WINDS ARE EXPECTED TO DROP BELOW ADVISORY CRITERIA SATURDAY
MORNING AND THEN SHIFT INTO THE NORTH SATURDAY AFTERNOON WITH THE
PASSAGE OF A COLD FRONT.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR VTZ003-
004-006>008-010>012-016>019.
NY...WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR NYZ034.
&&
$$
SYNOPSIS...JMG
NEAR TERM...RJS/LOCONTO
SHORT TERM...JMG
LONG TERM...DEAL
AVIATION...DEAL/MUCCILLI
MARINE...
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
933 PM EST SUN DEC 7 2014
.SYNOPSIS...
LOW PRESSURE WILL DEVELOP EARLY MONDAY ALONG A STALLED FRONT
OFFSHORE. THIS WILL BRING COOL WEATHER MONDAY ALONG WITH A CHANCE
OF LIGHT RAIN. THE LOW WILL PULL AWAY FROM THE AREA TUESDAY WITH
DRIER AIR OVERSPREADING THE AREA. BELOW NORMAL TEMPERATURES AND
DRY WEATHER IS EXPECTED MUCH OF THE WEEK AS CANADIAN HIGH
PRESSURE SLOWLY APPROACHES FROM THE NORTHWEST.
&&
.NEAR TERM /THROUGH MONDAY/...
AS OF 930 PM SUNDAY...NO PRECIPITATION IS ANTICIPATED OVERNIGHT
AND CLOUDS ARE EXPECTED TO INCREASE OVERNIGHT. THE 18 UTC NAM IS
SHOWING THIS IN INCREASE IN CLOUDS BEING SUPPORTED BY A 90% RH
LAYER OF MOISTURE MOVING INLAND IN RESPONSE TO THE WINDS AT 850 MB
VEERING TO THE EAST OVERNIGHT. MINIMUM TEMPERATURES ARE EXPECTED
TO FALL INTO THE LOW TO MIDDLE 30S BUT INCREASING CLOUDS OVERNIGHT
WILL TEMPER THE TEMPERATURES DECREASE.
&&
.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
AS OF 300 PM SUNDAY...AN UPPER LEVEL TROUGH WILL APPROACH FROM THE
WEST TUESDAY...TURNING NEGATIVELY TILTED AT 500 MB AS MOVES ACROSS
THE AREA DURING THE EVENING HOURS. THE APPROACH OF THIS TROUGH
SHOULD INDUCE LOW PRESSURE TO DEVELOP ALONG THE STALLED FRONT
ABOUT 400 MILES EAST OF CAPE FEAR MONDAY. THE SURFACE LOW WILL BE
PULLED NORTHWESTWARD BY THE APPROACHING UPPER TROUGH TOWARD THE
NC OUTER BANKS. INCREASING EASTERLY WINDS BETWEEN 3000-6000 FEET
WILL BE FORCED TO ASCEND AS THEY RIDE UP OVER A COOL WEDGE AIR MASS
INLAND AND THIS SHOULD DEVELOP PATCHES OF MAINLY LIGHT RAIN DURING
THE AFTERNOON AND EVENING HOURS...ESPECIALLY ACROSS THE PEE DEE
REGION AND SAND HILLS WHERE THE 285K ISENTROPIC SURFACE HAS THE
MOST RELATIVE TILT. THE MAGNITUDE OF 285K ISENTROPIC LIFT MATCHES
EXPECTED COVERAGE AND INTENSITY OF RAIN. THIS SHOULD NOT BE A
MAJOR RAINFALL EVENT WITH ONLY A FEW HUNDREDTHS OF AN INCH
EXPECTED.
THE ECMWF CONTINUES TO BE OUR PREFERRED MODEL ALTHOUGH THE 12Z GFS
WASN`T TOO BAD. THE 12Z NAM WAS NOT USED. GIVEN DENSE CLOUD COVER
AND THE WEDGE PATTERN MY FORECAST HIGHS ARE BELOW GUIDANCE ACROSS
NE SOUTH CAROLINA AND THE LUMBERTON AREA MONDAY: MID 40S INLAND
TO 50-51 AT THE COAST. LOWS MONDAY NIGHT MID-UPPER 30S.
TUESDAY...DEEP WEST AND NW WINDS SHOULD DRY THE COLUMN OUT WITH
PLENTY OF SUNSHINE DEVELOPING DURING THE DAY. HIGHS SHOULD REACH
THE LOWER-MID 50S AND LOWS MID-UPPER 30S.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 300 PM SUNDAY...A STRONG OMEGA BLOCK WILL DEVELOP AT THE MID LEVELS
WITH THE FIRST VESTIGES SEEN THURSDAY. A POTENT MID LEVEL LOW WILL
BE MEANDERING ACROSS THE NORTHEAST STATES WITH A DEEP LONG WAVE
TROUGH CRASHING ASHORE ALONG THE WEST. RIDGING WILL BE TAKING PLACE
ACROSS THE CENTRAL U.S. THIS PATTERN WILL BECOME MORE AMPLIFIED IN
TIME. BY THE END OF THE PERIOD...THE FLOW/PATTERN IS STILL INTACT
BUT DOES SHOW SIGNS OF BREAKING DOWN AND MOVING EAST.
THE SURFACE FEATURES OF NOTE INCLUDE LOW PRESSURE ACROSS THE
NORTHEAST AND HIGH PRESSURE ACROSS THE MISSISSIPPI VALLEY. A
CYCLONIC/COLD AND DRY FLOW WILL BE IN PLACE WEDNESDAY THROUGH
SATURDAY WITH A COUPLE OF SURFACE TROUGHS MOVING ACROSS...THESE
ASSOCIATED WITH WEAKER MID LEVEL FEATURES. BY LATER SATURDAY AND
SUNDAY...HIGH PRESSURE WILL SLOWLY BEGIN TO MOVE EAST. NO POPS
THROUGH THE PERIOD.
TEMPERATURE GUIDANCE SHOWS A REASONABLE TREND WITH COLD READINGS
WEDNESDAY THROUGH FRIDAY...LOW TO MIDDLE 50S FOR HIGHS WITH LOWS AT
OR JUST BELOW FREEZING. THE COLDEST MORNING APPEARS TO BE FRIDAY
WITH LINGERING COLD AIR UPSTAIRS AND DECENT RADIATIONAL CONDITIONS.
AIR MASS MODIFICATION WILL BEGIN TO SLOWLY WARM THINGS UP FOR THE
WEEKEND.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
AS OF 00Z...VFR EXPECTED OVERNIGHT WITH LOW CIGS CREATING MVFR
LATE INTO MONDAY...WITH VARYING VFR/MVFR ON MONDAY DUE TO LOW CIGS
AS WELL AS ISOLATED TO SCATTERED -SHRA/-RA.
VFR PREVAILS THIS EVENING WITH NORTHERLY WINDS AOB 12 KTS...AND
GUSTS AROUND 20 KTS ALONG THE COAST...AS WELL AS NEARLY CLEAR SKIES
INLAND AND LOW CIGS AROUND 3KFT ALONG THE COAST. EXPECT GUSTS TO
SUBSIDE AND FOR VFR TO CONTINUE INTO THE OVERNIGHT HOURS...WITH LOW
CIGS GRADUALLY INFILTRATING INTO THE COASTAL AREAS AND THEN TO THE
INLAND SITES BY MORNING. ON MONDAY...EXPECT MVFR DUE TO LOW CIGS TO
CONTINUE WITH INCREASING RAIN CHANCES INTO THE AFTERNOON AND EVENING
HOURS...THOUGH WILL NOT RULE OUT BRIEF PERIODS OF IMPROVEMENT TO VFR
WHERE THERE ARE ANY BREAKS IN THE CLOUD DECK. GUSTY NORTH WINDS WILL
PERSIST.
EXTENDED OUTLOOK...MVFR CIGS/SHOWERS INTO TUESDAY. OTHERWISE EXPECT
VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 930 PM SUNDAY...A MARGINAL GALE WARNING CONTINUES FOR N
WINDS OF 25 TO 30 KT INTO TONIGHT AS GUSTS ARE STILL AROUND THE 35
KT LEVEL AT 41013. THE 00 UTC RUN OF THE HRRR CONTINUES TO SHOW THE
PRESSURE GRADIENT TIGHT OVERNIGHT AND IS MAINTAINING THE 25 TO 30
KT WINDS WITH HIGHER GUST OVERNIGHT. SEAS WILL CONTINUE AT 5 TO 7
FT...WITH HIGHER SEAS AT 20 MILES OFF THE COAST AND IN SOUTH
CAROLINA WATERS SOUTH OF MYRTLE BEACH. LOWER WAVE HEIGHTS ARE
EXPECTED NEARER THE COAST WHERE WIND DIRECTION WILL BE
OFFSHORE...MAINLY BETWEEN BALD HEAD AND NORTH MYRTLE BEACH.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 300 PM SUNDAY...1045 MB ARCTIC HIGH PRESSURE WILL BE MOVING
INTO THE CANADIAN MARITIME PROVINCES MONDAY MORNING WHILE LOW
PRESSURE DEVELOPS ABOUT 400 MILES EAST OF CAPE FEAR ALONG THE
STALLED FRONT. ALTHOUGH THE MODELS DIFFER IN DETAILS ALL GUIDANCE
SHOWS THE LOW MOVING NORTHWESTWARD TOWARD THE OUTER BANKS MONDAY
AFTERNOON AND EVENING...TURNING NORTHWARD BEFORE REACHING LAND
OVERNIGHT. FOR OUR PORTION OF THE CAROLINAS THIS MEANS A
CONTINUATION OF BRISK NORTHERLY WINDS THROUGH MONDAY NIGHT...
ALBEIT WITH GRADUALLY DIMINISHING WIND SPEEDS DUE TO LESSENING
INFLUENCE FROM THE CANADIAN HIGH.
AS THE LOW MOVES ALONG THE MID-ATLANTIC COAST TUESDAY...OUR WINDS
SHOULD BACK TO THE NORTHWEST ALLOWING DRIER AIR TO BUILD OFFSHORE.
LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 300 PM SUNDAY...EXPECT STEADY STATE CONDITIONS WEDNESDAY AND
EARLY THURSDAY WITH NORTHWEST WINDS OF 10-15 KNOTS AND SEAS OF 2-5
FEET WITH THE FIVE FOOTERS RELEGATED TO THE OUTERMOST WATERS. A
SURFACE TROUGH WILL MOVE ACROSS EARLY THURSDAY TO KICK UP WINDS A
COUPLE OF KNOTS BRIEFLY. LATER THURSDAY...WINDS DIMINISH TO AROUND
TEN KNOTS WHICH WILL CONTINUE THROUGH FRIDAY. SEAS DROP TO 1-3
FEET.
&&
.TIDES/COASTAL FLOODING...
AS OF 300 PM SUNDAY...STORM SURGE AT MYRTLE BEACH IS APPROACHING
1.0 FEET THIS AFTERNOON. ASTRONOMICAL TIDE PREDICTIONS SHOW WE
WILL NEED 1.6 FEET OF SURGE TO PRODUCE MINOR COASTAL FLOODING AT
MYRTLE BEACH WITH THE MONDAY MORNING (820 AM) HIGH TIDE. NO
COASTAL FLOODING ADVISORIES ARE PLANNED AT THIS TIME.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...GALE WARNING UNTIL 6 AM EST MONDAY FOR AMZ250-252-254-256.
&&
$$
SYNOPSIS...
NEAR TERM...DRH
SHORT TERM...TRA
LONG TERM...SHK
AVIATION...SGL
MARINE...
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
633 PM EST SUN DEC 7 2014
.SYNOPSIS...
LOW PRESSURE WILL DEVELOP EARLY MONDAY ALONG A STALLED FRONT
OFFSHORE. THIS WILL BRING COOL WEATHER MONDAY ALONG WITH A CHANCE
OF LIGHT RAIN. THE LOW WILL PULL AWAY FROM THE AREA TUESDAY WITH
DRIER AIR OVERSPREADING THE AREA. BELOW NORMAL TEMPERATURES AND
DRY WEATHER IS EXPECTED MUCH OF THE WEEK AS CANADIAN HIGH
PRESSURE SLOWLY APPROACHES FROM THE NORTHWEST.
&&
.NEAR TERM /THROUGH MONDAY/...
AS OF 630 PM SUNDAY...NO PRECIPITATION IS ANTICIPATED OVERNIGHT AND CLOUDS
ARE EXPECTED TO INCREASE OVERNIGHT. THE 18 UTC NAM IS SHOWING THIS
IN INCREASE IN CLOUDS BEING SUPPORTED BY A 90% RH LAYER OF
MOISTURE MOVING INLAND IN RESPONSE TO THE WINDS AT 850 MB VEERING TO
THE EAST OVERNIGHT. MINIMUM TEMPERATURES ARE EXPECTED TO FALL
INTO THE LOW TO MIDDLE 30S BUT INCREASING CLOUDS OVERNIGHT WILL
TEMPER THE TEMPERATURES DECREASE.
&&
.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
AS OF 300 PM SUNDAY...AN UPPER LEVEL TROUGH WILL APPROACH FROM THE
WEST TUESDAY...TURNING NEGATIVELY TILTED AT 500 MB AS MOVES ACROSS
THE AREA DURING THE EVENING HOURS. THE APPROACH OF THIS TROUGH
SHOULD INDUCE LOW PRESSURE TO DEVELOP ALONG THE STALLED FRONT
ABOUT 400 MILES EAST OF CAPE FEAR MONDAY. THE SURFACE LOW WILL BE
PULLED NORTHWESTWARD BY THE APPROACHING UPPER TROUGH TOWARD THE
NC OUTER BANKS. INCREASING EASTERLY WINDS BETWEEN 3000-6000 FEET
WILL BE FORCED TO ASCEND AS THEY RIDE UP OVER A COOL WEDGE AIR MASS
INLAND AND THIS SHOULD DEVELOP PATCHES OF MAINLY LIGHT RAIN DURING
THE AFTERNOON AND EVENING HOURS...ESPECIALLY ACROSS THE PEE DEE
REGION AND SAND HILLS WHERE THE 285K ISENTROPIC SURFACE HAS THE
MOST RELATIVE TILT. THE MAGNITUDE OF 285K ISENTROPIC LIFT MATCHES
EXPECTED COVERAGE AND INTENSITY OF RAIN. THIS SHOULD NOT BE A
MAJOR RAINFALL EVENT WITH ONLY A FEW HUNDREDTHS OF AN INCH
EXPECTED.
THE ECMWF CONTINUES TO BE OUR PREFERRED MODEL ALTHOUGH THE 12Z GFS
WASN`T TOO BAD. THE 12Z NAM WAS NOT USED. GIVEN DENSE CLOUD COVER
AND THE WEDGE PATTERN MY FORECAST HIGHS ARE BELOW GUIDANCE ACROSS
NE SOUTH CAROLINA AND THE LUMBERTON AREA MONDAY: MID 40S INLAND
TO 50-51 AT THE COAST. LOWS MONDAY NIGHT MID-UPPER 30S.
TUESDAY...DEEP WEST AND NW WINDS SHOULD DRY THE COLUMN OUT WITH
PLENTY OF SUNSHINE DEVELOPING DURING THE DAY. HIGHS SHOULD REACH
THE LOWER-MID 50S AND LOWS MID-UPPER 30S.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 300 PM SUNDAY...A STRONG OMEGA BLOCK WILL DEVELOP AT THE MID LEVELS
WITH THE FIRST VESTIGES SEEN THURSDAY. A POTENT MID LEVEL LOW WILL
BE MEANDERING ACROSS THE NORTHEAST STATES WITH A DEEP LONG WAVE
TROUGH CRASHING ASHORE ALONG THE WEST. RIDGING WILL BE TAKING PLACE
ACROSS THE CENTRAL U.S. THIS PATTERN WILL BECOME MORE AMPLIFIED IN
TIME. BY THE END OF THE PERIOD...THE FLOW/PATTERN IS STILL INTACT
BUT DOES SHOW SIGNS OF BREAKING DOWN AND MOVING EAST.
THE SURFACE FEATURES OF NOTE INCLUDE LOW PRESSURE ACROSS THE
NORTHEAST AND HIGH PRESSURE ACROSS THE MISSISSIPPI VALLEY. A
CYCLONIC/COLD AND DRY FLOW WILL BE IN PLACE WEDNESDAY THROUGH
SATURDAY WITH A COUPLE OF SURFACE TROUGHS MOVING ACROSS...THESE
ASSOCIATED WITH WEAKER MID LEVEL FEATURES. BY LATER SATURDAY AND
SUNDAY...HIGH PRESSURE WILL SLOWLY BEGIN TO MOVE EAST. NO POPS
THROUGH THE PERIOD.
TEMPERATURE GUIDANCE SHOWS A REASONABLE TREND WITH COLD READINGS
WEDNESDAY THROUGH FRIDAY...LOW TO MIDDLE 50S FOR HIGHS WITH LOWS AT
OR JUST BELOW FREEZING. THE COLDEST MORNING APPEARS TO BE FRIDAY
WITH LINGERING COLD AIR UPSTAIRS AND DECENT RADIATIONAL CONDITIONS.
AIR MASS MODIFICATION WILL BEGIN TO SLOWLY WARM THINGS UP FOR THE
WEEKEND.
&&
.AVIATION /00Z SUNDAY THROUGH FRIDAY/...
AS OF 00Z...VFR EXPECTED OVERNIGHT WITH LOW CIGS CREATING MVFR
LATE INTO MONDAY...WITH VARYING VFR/MVFR ON MONDAY DUE TO LOW CIGS
AS WELL AS ISOLATED TO SCATTERED -SHRA/-RA.
VFR PREVAILS THIS EVENING WITH NORTHERLY WINDS AOB 12 KTS...AND
GUSTS AROUND 20 KTS ALONG THE COAST...AS WELL AS NEARLY CLEAR SKIES
INLAND AND LOW CIGS AROUND 3KFT ALONG THE COAST. EXPECT GUSTS TO
SUBSIDE AND FOR VFR TO CONTINUE INTO THE OVERNIGHT HOURS...WITH LOW
CIGS GRADUALLY INFILTRATING INTO THE COASTAL AREAS AND THEN TO THE
INLAND SITES BY MORNING. ON MONDAY...EXPECT MVFR DUE TO LOW CIGS TO
CONTINUE WITH INCREASING RAIN CHANCES INTO THE AFTERNOON AND EVENING
HOURS...THOUGH WILL NOT RULE OUT BRIEF PERIODS OF IMPROVEMENT TO VFR
WHERE THERE ARE ANY BREAKS IN THE CLOUD DECK. GUSTY NORTH WINDS WILL
PERSIST.
EXTENDED OUTLOOK...MVFR CIGS/SHOWERS INTO TUESDAY. OTHERWISE EXPECT
VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 630 PM SUNDAY...A MARGINAL GALE WARNING CONTINUES FOR N
WINDS OF 25 TO 30 KT INTO TONIGHT AS GUSTS ARE STILL AROUND THE
35 KT LEVEL AT 41013. THE 21 UTC RUN OF THE HRRR CONTINUES TO SHOW
THE PRESSURE GRADIENT TIGHT OVERNIGHT AND IS MAINTAINING THE 25 TO 30
KT WINDS WITH HIGHER GUST OVERNIGHT. SEAS WILL CONTINUE AT 5 TO 7
FT...WITH HIGHER SEAS AT 20 MILES OFF THE COAST AND IN SOUTH
CAROLINA WATERS SOUTH OF MYRTLE BEACH. LOWER WAVE HEIGHTS ARE
EXPECTED NEARER THE COAST WHERE WIND DIRECTION WILL BE
OFFSHORE...MAINLY BETWEEN BALD HEAD AND NORTH MYRTLE BEACH.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 300 PM SUNDAY...1045 MB ARCTIC HIGH PRESSURE WILL BE MOVING
INTO THE CANADIAN MARITIME PROVINCES MONDAY MORNING WHILE LOW
PRESSURE DEVELOPS ABOUT 400 MILES EAST OF CAPE FEAR ALONG THE
STALLED FRONT. ALTHOUGH THE MODELS DIFFER IN DETAILS ALL GUIDANCE
SHOWS THE LOW MOVING NORTHWESTWARD TOWARD THE OUTER BANKS MONDAY
AFTERNOON AND EVENING...TURNING NORTHWARD BEFORE REACHING LAND
OVERNIGHT. FOR OUR PORTION OF THE CAROLINAS THIS MEANS A
CONTINUATION OF BRISK NORTHERLY WINDS THROUGH MONDAY NIGHT...
ALBEIT WITH GRADUALLY DIMINISHING WIND SPEEDS DUE TO LESSENING
INFLUENCE FROM THE CANADIAN HIGH.
AS THE LOW MOVES ALONG THE MID-ATLANTIC COAST TUESDAY...OUR WINDS
SHOULD BACK TO THE NORTHWEST ALLOWING DRIER AIR TO BUILD OFFSHORE.
LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 300 PM SUNDAY...EXPECT STEADY STATE CONDITIONS WEDNESDAY AND
EARLY THURSDAY WITH NORTHWEST WINDS OF 10-15 KNOTS AND SEAS OF 2-5
FEET WITH THE FIVE FOOTERS RELEGATED TO THE OUTERMOST WATERS. A
SURFACE TROUGH WILL MOVE ACROSS EARLY THURSDAY TO KICK UP WINDS A
COUPLE OF KNOTS BRIEFLY. LATER THURSDAY...WINDS DIMINISH TO AROUND
TEN KNOTS WHICH WILL CONTINUE THROUGH FRIDAY. SEAS DROP TO 1-3
FEET.
&&
.TIDES/COASTAL FLOODING...
AS OF 300 PM SUNDAY...STORM SURGE AT MYRTLE BEACH IS APPROACHING
1.0 FEET THIS AFTERNOON. ASTRONOMICAL TIDE PREDICTIONS SHOW WE
WILL NEED 1.6 FEET OF SURGE TO PRODUCE MINOR COASTAL FLOODING AT
MYRTLE BEACH WITH THE MONDAY MORNING (820 AM) HIGH TIDE. NO
COASTAL FLOODING ADVISORIES ARE PLANNED AT THIS TIME.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...GALE WARNING UNTIL 6 AM EST MONDAY FOR AMZ250-252-254-256.
&&
$$
NEAR TERM...HAWKINS
SHORT TERM...TRA
LONG TERM...SHK
AVIATION...SGL
AREA FORECAST DISCUSSION
NWS RALEIGH NC
708 AM EST SAT DEC 6 2014
.SYNOPSIS...A SHORTWAVE TROUGH INITIALLY OVER THE MID MS AND TN
VALLEYS WILL AMPLIFY ACROSS THE SOUTHERN APPALACHIANS AND CAROLINAS
THROUGH TONIGHT. AN ACCOMPANYING SURFACE LOW OVER THE LOWER OH AND
TN VALLEY WILL RE-DEVELOP OVER VA/NC TODAY...THEN BEGIN TO INTENSIFY
AS IT APPROACHES A COASTAL FRONT ALONG THE NC COAST THIS EVENING-
TONIGHT. MEANWHILE...ARCTIC HIGH PRESSURE WILL STRENGTHEN AS IT
MIGRATES FROM THE NORTHERN PLAINS TO NEW ENGLAND...THE SOUTHERN
PERIPHERY OF WHICH WILL RIDGE SOUTH INTO NC LATE TONIGHT THROUGH
SUNDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM SATURDAY...
A COASTAL FRONT ALONG THE SOUTHEAST AND MIDDLE ATLANTIC COASTS HAS
CAUSED A PIECE OF THE 1040 MB MODIFIED ARCTIC CENTERED NEAR
NEWFOUNDLAND TO BREAK OFF OVER THE CAROLINAS THIS MORNING...AND THIS
1027 MB HIGH WILL LIKELY ESTABLISH A SHORT-LIVED IN-SITU CAD EVENT
OVER AT LEAST THE WESTERN PIEDMONT TODAY. WHETHER OR NOT THE WEDGE
IS ESTABLISHED EAST ACROSS THE REMAINDER OF CENTRAL NC IS MORE IN
QUESTION...SINCE IT SEEMS THE UPSTREAM PRE-FRONTAL BAND OF RAIN NOW
CROSSING THE SOUTHERN-CENTRAL APPALACHIANS HAS BEEN FALLING MOSTLY
FROM MID LEVEL CEILINGS...AND AS SUCH...WOULD MAKE IT LESS LIKELY TO
FULLY SATURATE THE LOW LEVELS AND HELP ESTABLISH A WEDGE. IN
FACT...BOTH THE RAP AND HRRR SUGGEST THE INITIAL BAND OF IFR-MVFR
CEILINGS CENTERED FROM NEAR CAE TO RDU TO RIC THIS MORNING WILL
DRIFT EAST THROUGH MIDDAY...AND PROVIDE FOR A PERIOD OF MOSTLY MID-
HIGH LEVEL CLOUDS AND MODEST INSOLATION DURING THE MIDDAY-EARLY
AFTERNOON HOURS. THE MAIN SENSIBLE WEATHER IMPACT WITH THIS
UNCERTAINTY REGARDS TEMPERATURES...WHICH WOULD BE HELD IN THE MID-
UPPER 40S OVER THE NW PIEDMONT (SIMILAR TO FRI) TO GENERALLY MID 50S
ELSEWHERE IF IN-SITU WEDGING BECAME ESTABLISHED. HOWEVER...BASED ON
UPSTREAM OBSERVATIONS OF RAIN FROM MOSTLY MID CLOUDS...WILL TREND
HIGH TEMPS TOWARD SOME MODEST INSOLATION...WITH HIGHS RANGING FROM
THE MIDDLE 50S TO NEAR 60 DEGREES...EXCEPT AROUND 50 DEGREES OR SO
IN THE WESTERN PIEDMONT WHERE THE OPPORTUNITY FOR INSOLATION WILL BE
MORE LIMITED BETWEEN THE PRE-FRONTAL RAIN BAND...AND A TRAILING
SEPARATE AREA OF SHALLOW CONVECTIVE PRECIPITATION FORECAST TO MOVE
ACROSS THE AREA LATER THIS AFTERNOON AND EVENING.
THAT TRAILING PRECIPITATION WILL BE FUELED BY SUBSTANTIAL COOLING
ALOFT ACCOMPANYING A PARENT SHORTWAVE TROUGH ALOFT...ATOP A WARM AND
MOIST...40 KT LLJ. THE ASSOCIATED STRONG DIFFERENTIAL THERMAL
ADVECTION WILL CAUSE H85-5 LAPSE RATES TO STEEPEN IN EXCESS OF 6.5
C/KM OVER CENTRAL NC...COINCIDENT WITH 50-80 METER MID LEVEL HEIGHT
FALLS ACCOMPANYING THE PARENT SHORTWAVE TROUGH ALOFT. FORECAST
GUIDANCE CONTINUES TO SUGGEST THAT A POCKET OF UP TO A FEW HUNDRED
J/KG OF MUCAPE WILL CONSEQUENTLY DEVELOP OVER OUR AREA THIS
AFTERNOON...WHICH WILL SUPPORT THE EASTWARD PROGRESSION AND/OR RE-
DEVELOPMENT OF NUMEROUS TO WIDESPREAD SHOWERS AND ISOLATED
THUNDERSTORMS ACROSS CENTRAL NC THIS AFTERNOON.
THOUGH SHOWERS AND ISOLATED STORMS WILL MOVE EAST WITH THE PASSAGE
OF THE OCCLUDED/COLD FRONT THIS EVENING...THE DEEPENING OF A SURFACE
LOW AS IT ENCOUNTERS THE COASTAL FRONT WILL MAINTAIN A MOIST NNE
FLOW THAT WILL LIKELY RESULT IN CONSIDERABLE LOW OVERCAST AND AREAS
OF LIGHT RAIN OR DRIZZLE...WHICH WILL ONLY SLOWLY EDGE EASTWARD
THROUGH SUN MORNING...PARTICULARLY OVER THE EASTERN TWO THIRDS OF
THE CWFA. IT WILL ALSO BECOME NOTICEABLY BLUSTERY IN STRONG CAA AS
THE LOW LEVEL RIDGING BUILDS EAST OF THE APPALACHIANS...WITH LOWS
MOSTLY IN THE LOWER TO MIDDLE 40S.
&&
.SHORT TERM /SUNDAY AND SUNDAY NIGHT/...
AS OF 340 AM SATURDAY...
SUNDAY AND SUNDAY NIGHT: BRIEF SHORTWAVE RIDGING WILL BUILD EAST
ACROSS OUR REGION AND CAUSE STRONG ARCTIC HIGH PRESSURE CENTERED
OVER NEW ENGLAND TO RIDGE DOWN THE EAST COAST THIS PERIOD...IN
ADVANCE OF A PAIR OF PHASED (OR NEARLY SO) SHORTWAVE TROUGHS
FORECAST TO AMPLIFY FROM THE PLAINS TO THE MS VALLEY THROUGH SUN
NIGHT. DESPITE MAINLY CLEAR SKIES...EXCEPT SOME LINGERING LOW CLOUDS
OVER EASTERN NC...A BRISK AND GUSTY NE WIND WILL RESULT IN RATHER
CHILLY CONDITIONS...WITH HIGHS MOSTLY IN THE MID-UPPER 40S (TO NEAR
50 SOUTH). THE AMPLIFICATION OF THE AFOREMENTIONED TROUGHS ALOFT
WILL CAUSE THE LOW LEVEL FLOW (925 MB) TO ASSUME AN INCREASINGLY
EASTERLY COMPONENT (TOWARD THE PRESSURE FALLS ACCOMPANYING HE
APPROACHING TROUGH)...SUCH THAT THE LOW CLOUDS OVER THE EASTERN PART
OF THE STATE WILL DEVELOP/ADVECT WSW ACROSS CENTRAL NC THROUGH MON
MORNING. LOWS RANGING FROM THE UPPER 20S IN THE WEST TO MIDDLE 30S
EAST.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 335 AM SATURDAY...
CONFIDENCE IS LOWER THAN DESIRED FOR A DAY 3 (MONDAY) FORECAST DUE
TO MODEL DIFFERENCES REGARDING THE INTERACTION OF NORTHERN AND
SOUTHERN STREAM SHORTWAVES AS THEY CROSS THE CENTRAL AND EASTERN US.
MODELS HAVE BEEN COMING INTO A LITTLE BETTER AGREEMENT...SHOWING THE
LEAD SOUTHERN STREAM SHORTWAVE MOVING FROM THE DEEP SOUTH ACROSS THE
CAROLINAS ON MONDAY...WITH A NORTHERN STREAM WAVE TO DIVE SOUTH
ACROSS THE REGION ON TUESDAY. IN RESPONSE TO THE LEAD WAVE...A
SURFACE LOW OFF THE SOUTHEAST COAST WILL RE-INTENSIFY AND LIFT NORTH
ALONG THE EAST COAST. THE NAM AND CANADIAN ARE STRONG OUTLIERS
REGARDING THE STRENGTH OF THE LOW AND ASSOCIATED PRECEDING EASTERLY
FLOW...PRODUCING HEAVIER PRECIP EARLIER ON MONDAY. THE ECMWF IS A
LITTLE MORE AMPLIFIED WITH THE LEAD WAVE...RESULTING MORE PRECIP
THAN THE GFS...BUT STILL RELATIVELY LIGHT AND NOT UNTIL MONDAY
AFTERNOON. THIS HAS SOME SIGNIFICANCE...AS A STRONG 1040+ MB
SURFACE HIGH EXTENDING INTO THE NC FROM NEW ENGLAND WILL BE
RETREATING DURING THE DAY BUT WOULD OFFER SOME PTYPE CONCERNS IN THE
NORTHWEST PIEDMONT WITH PRECIP EARLY MONDAY MORNING...AS THE NAM
DEPICTS. HOWEVER THIS IS DISCOUNTED AT THIS TIME. WILL SHOW POPS
INCREASING BY MIDDAY...SLIGHT CHANCE WEST TO CHANCE IN THE
EAST...ENDING FROM SOUTHWEST TO NORTHEAST MONDAY NIGHT AS THE
SURFACE LOW MOVES OFF TO THE NORTHEAST. THE QPF FORECAST IS FOR LESS
THAN A TENTH OF AN INCH...BUT WOULDNT BE SURPRISED TO SEE MODELS
PRODUCE MORE PRECIP IN LATER RUNS. HAVE LOWERED HIGHS A FEW DEGREES
ACROSS THE PIEDMONT BASED ON INCREASING POTENTIAL FOR
PRECIP...RANGING FROM LOWER 40S NORTHWEST TO NEAR 50 SOUTHEAST.
LOWS MONDAY NIGHT IN THE LOWER 30S NORTHEAST TO UPPER 30S SOUTHEAST.
A STRONG NORTHERN STREAM SHORTWAVE WILL DIVE ACROSS NC ON
TUESDAY....FOLLOWED BY A REINFORCING SHOT OF COLD ADVECTION TUESDAY
NIGHT. THE ECMWF SPITS OUT SOME VERY LIGHT QPF ACROSS THE NORTH
TUESDAY AFTERNOON...BUT WILL HOLD OFF ON INTRODUCING POPS AS MOISTURE
WILL BE LIMITED. HIGH PRESSURE IS THEN FORECAST TO BUILD ACROSS
THEN BUILD SLOWLY ACROSS THE SOUTHEAST BETWEEN AN UPPER LOW THAT
CLOSES OFF OVER NEW ENGLAND AND RIDGING OVER THE CENTRAL US. TEMPS
MAY SLOWLY MODERATE BUT WILL REMAIN AT OR JUST BELOW NORMAL.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 700 AM SATURDAY...
COMPLEX FORECAST FOR THIS TAF PERIOD...AND BEYOND THROUGH EARLY THIS
UPCOMING WEEK.
AN AXIS OF IFR-MVFR STRATUS WILL LIKELY SHIFT EAST OF RDU/FAY/RWI
BETWEEN 15-18Z...AS THE FLOW IN THAT LAYER VEERS FROM SOUTHERLY TO
SOUTHWESTERLY...AFTER WHICH TIME A SEVERAL HOUR PERIOD OF VFR
CONDITIONS ARE PROBABLE DURING THE MIDDAY TO EARLY AFTERNOON HOURS.
MEANWHILE...A PRE-FRONTAL BAND OF RAIN...FALLING FROM MOSTLY VFR
CEILINGS BUT PRODUCING MVFR SURFACE VISIBILITY RESTRICTIONS...WILL
MOVE EAST AND ARRIVE AT RDU AND FAY BETWEEN 14-15Z AND RWI BETWEEN
16-18Z...BASICALLY ON THE HEELS OF THE DEPARTING INITIAL BAND OF
MVFR CEILINGS. THEN YET A THIRD REGIME OF IFR-MVFR CONDITIONS AND
NUMEROUS TO WIDESPREAD SHOWERS (AND ISOLATED THUNDERSTORMS) WILL
SWEEP EAST INTO OUR AREA BETWEEN 17-19Z AT WESTERN TERMINALS TO
BETWEEN 20-23Z AT EASTERN ONES. THE PASSAGE OF A COLD FRONT AND
FOLLOWING BRISK NW BREEZE WILL HELP SCOUR AND LIFT THE CLOUD
LAYER...PARTICULARLY AT TRIAD TERMINALS THIS EVENING...THOUGH SUB-
VFR CONDITIONS AND AREAS OF LIGHT RAIN OR DRIZZLE ARE APT TO LINGER
THROUGHOUT THE NIGHT...ESPECIALLY AT RDU/RWI/FAY.
OUTLOOK: IN THE WAKE OF THE AFOREMENTIONED COLD FRONT...BRISK NNE
WINDS...AND A THREAT OF MVFR CEILINGS AT EASTERN TERMINALS...ARE
EXPECTED ON SUNDAY. WHILE FORECAST CONFIDENCE IS BELOW AVERAGE...THE
DEVELOPMENT OF A COASTAL STORM NEAR THE SOUTH AND MIDDLE ATLANTIC
COAST MAY RESULT IN A REDEVELOPMENT/SOUTHWESTWARD EXPANSION OF MVFR
CEILINGS...AND POSSIBLY RAIN...LATE SUN NIGHT-MON NIGHT.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...MWS
SHORT TERM...MWS
LONG TERM...BLS
AVIATION...MWS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
706 AM EST SAT DEC 6 2014
.SYNOPSIS...A SHORTWAVE TROUGH INITIALLY OVER THE MID MS AND TN
VALLEYS WILL AMPLIFY ACROSS THE SOUTHERN APPALACHIANS AND CAROLINAS
THROUGH TONIGHT. AN ACCOMPANYING SURFACE LOW OVER THE LOWER OH AND
TN VALLEY WILL RE-DEVELOP OVER VA/NC TODAY...THEN BEGIN TO INTENSIFY
AS IT APPROACHES A COASTAL FRONT ALONG THE NC COAST THIS EVENING-
TONIGHT. MEANWHILE...ARCTIC HIGH PRESSURE WILL STRENGTHEN AS IT
MIGRATES FROM THE NORTHERN PLAINS TO NEW ENGLAND...THE SOUTHERN
PERIPHERY OF WHICH WILL RIDGE SOUTH INTO NC LATE TONIGHT THROUGH
SUNDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM SATURDAY...
A COASTAL FRONT ALONG THE SOUTHEAST AND MIDDLE ATLANTIC COASTS HAS
CAUSED A PIECE OF THE 1040 MB MODIFIED ARCTIC CENTERED NEAR
NEWFOUNDLAND TO BREAK OFF OVER THE CAROLINAS THIS MORNING...AND THIS
1027 MB HIGH WILL LIKELY ESTABLISH A SHORT-LIVED IN-SITU CAD EVENT
OVER AT LEAST THE WESTERN PIEDMONT TODAY. WHETHER OR NOT THE WEDGE
IS ESTABLISHED EAST ACROSS THE REMAINDER OF CENTRAL NC IS MORE IN
QUESTION...SINCE IT SEEMS THE UPSTREAM PRE-FRONTAL BAND OF RAIN NOW
CROSSING THE SOUTHERN-CENTRAL APPALACHIANS HAS BEEN FALLING MOSTLY
FROM MID LEVEL CEILINGS...AND AS SUCH...WOULD MAKE IT LESS LIKELY TO
FULLY SATURATE THE LOW LEVELS AND HELP ESTABLISH A WEDGE. IN
FACT...BOTH THE RAP AND HRRR SUGGEST THE INITIAL BAND OF IFR-MVFR
CEILINGS CENTERED FROM NEAR CAE TO RDU TO RIC THIS MORNING WILL
DRIFT EAST THROUGH MIDDAY...AND PROVIDE FOR A PERIOD OF MOSTLY MID-
HIGH LEVEL CLOUDS AND MODEST INSOLATION DURING THE MIDDAY-EARLY
AFTERNOON HOURS. THE MAIN SENSIBLE WEATHER IMPACT WITH THIS
UNCERTAINTY REGARDS TEMPERATURES...WHICH WOULD BE HELD IN THE MID-
UPPER 40S OVER THE NW PIEDMONT (SIMILAR TO FRI) TO GENERALLY MID 50S
ELSEWHERE. BASED ON UPSTREAM OBSERVATIONS OF RAIN FROM MOSTLY MID
CLOUDS...WILL TREND HIGH TEMPS TOWARD SOME MODEST INSOLATION...WITH
HIGHS RANGING FROM THE MIDDLE 50S TO NEAR 60 DEGREES...EXCEPT AROUND
50 DEGREES OR SO IN THE WESTERN PIEDMONT WHERE THE OPPORTUNITY FOR
INSOLATION WILL BE MORE LIMITED BETWEEN THE PRE-FRONTAL RAIN
BAND...AND A TRAILING SEPARATE AREA OF SHALLOW CONVECTIVE
PRECIPITATION FORECAST TO MOVE ACROSS THE AREA LATER THIS AFTERNOON.
THAT TRAILING PRECIPITATION WILL BE FUELED BY SUBSTANTIAL COOLING
ALOFT ACCOMPANYING A PARENT SHORTWAVE TROUGH ALOFT...ATOP A WARM AND
MOIST...40 KT LLJ. THE ASSOCIATED STRONG DIFFERENTIAL THERMAL
ADVECTION WILL CAUSE H85-5 LAPSE RATES TO STEEPEN IN EXCESS OF 6.5
C/KM OVER CENTRAL NC...COINCIDENT WITH 50-80 METER MID LEVEL HEIGHT
FALLS ACCOMPANYING THE PARENT SHORTWAVE TROUGH ALOFT. FORECAST
GUIDANCE CONTINUES TO SUGGEST THAT A POCKET OF UP TO A FEW HUNDRED
J/KG OF MUCAPE WILL CONSEQUENTLY DEVELOP OVER OUR AREA THIS
AFTERNOON...WHICH WILL SUPPORT THE EASTWARD PROGRESSION AND/OR RE-
DEVELOPMENT OF NUMEROUS TO WIDESPREAD SHOWERS AND ISOLATED
THUNDERSTORMS ACROSS CENTRAL NC THIS AFTERNOON.
THOUGH SHOWERS AND ISOLATED STORMS WILL MOVE EAST WITH THE PASSAGE
OF A THE OCCLUDED/COLD FRONT THIS EVENING...THE DEEPENING OF A
SURFACE LOW AS IT ENCOUNTERS THE COASTAL FRONT WILL MAINTAIN A MOIST
NNE FLOW THAT WILL LIKELY RESULT IN CONSIDERABLE LOW OVERCAST AND
AREAS OF LIGHT RAIN OR DRIZZLE...WHICH WILL ONLY SLOWLY EDGE
EASTWARD THROUGH SUN MORNING...PARTICULARLY OVER THE EASTERN TWO
THIRDS OF THE CWFA. IT WILL ALSO BECOME NOTICEABLY BLUSTERY IN STRONG
CAA AS THE LOW LEVEL RIDGING BUILDS EAST OF THE APPALACHIANS...WITH
LOWS MOSTLY IN THE LOWER TO MIDDLE 40S.
&&
.SHORT TERM /SUNDAY AND SUNDAY NIGHT/...
AS OF 340 AM SATURDAY...
SUNDAY AND SUNDAY NIGHT: BRIEF SHORTWAVE RIDGING WILL BUILD EAST
ACROSS OUR REGION AND CAUSE STRONG ARCTIC HIGH PRESSURE CENTERED
OVER NEW ENGLAND TO RIDGE DOWN THE EAST COAST THIS PERIOD...IN
ADVANCE OF A PAIR OF PHASED (OR NEARLY SO) SHORTWAVE TROUGHS
FORECAST TO AMPLIFY FROM THE PLAINS TO THE MS VALLEY THROUGH SUN
NIGHT. DESPITE MAINLY CLEAR SKIES...EXCEPT SOME LINGERING LOW CLOUDS
OVER EASTERN NC...A BRISK AND GUSTY NE WIND WILL RESULT IN RATHER
CHILLY CONDITIONS...WITH HIGHS MOSTLY IN THE MID-UPPER 40S (TO NEAR
50 SOUTH). THE AMPLIFICATION OF THE AFOREMENTIONED TROUGHS ALOFT
WILL CAUSE THE LOW LEVEL FLOW (925 MB) TO ASSUME AN INCREASINGLY
EASTERLY COMPONENT (TOWARD THE PRESSURE FALLS ACCOMPANYING HE
APPROACHING TROUGH)...SUCH THAT THE LOW CLOUDS OVER THE EASTERN PART
OF THE STATE WILL DEVELOP/ADVECT WSW ACROSS CENTRAL NC THROUGH MON
MORNING. LOWS RANGING FROM THE UPPER 20S IN THE WEST TO MIDDLE 30S
EAST.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 335 AM SATURDAY...
CONFIDENCE IS LOWER THAN DESIRED FOR A DAY 3 (MONDAY) FORECAST DUE
TO MODEL DIFFERENCES REGARDING THE INTERACTION OF NORTHERN AND
SOUTHERN STREAM SHORTWAVES AS THEY CROSS THE CENTRAL AND EASTERN US.
MODELS HAVE BEEN COMING INTO A LITTLE BETTER AGREEMENT...SHOWING THE
LEAD SOUTHERN STREAM SHORTWAVE MOVING FROM THE DEEP SOUTH ACROSS THE
CAROLINAS ON MONDAY...WITH A NORTHERN STREAM WAVE TO DIVE SOUTH
ACROSS THE REGION ON TUESDAY. IN RESPONSE TO THE LEAD WAVE...A
SURFACE LOW OFF THE SOUTHEAST COAST WILL RE-INTENSIFY AND LIFT NORTH
ALONG THE EAST COAST. THE NAM AND CANADIAN ARE STRONG OUTLIERS
REGARDING THE STRENGTH OF THE LOW AND ASSOCIATED PRECEDING EASTERLY
FLOW...PRODUCING HEAVIER PRECIP EARLIER ON MONDAY. THE ECMWF IS A
LITTLE MORE AMPLIFIED WITH THE LEAD WAVE...RESULTING MORE PRECIP
THAN THE GFS...BUT STILL RELATIVELY LIGHT AND NOT UNTIL MONDAY
AFTERNOON. THIS HAS SOME SIGNIFICANCE...AS A STRONG 1040+ MB
SURFACE HIGH EXTENDING INTO THE NC FROM NEW ENGLAND WILL BE
RETREATING DURING THE DAY BUT WOULD OFFER SOME PTYPE CONCERNS IN THE
NORTHWEST PIEDMONT WITH PRECIP EARLY MONDAY MORNING...AS THE NAM
DEPICTS. HOWEVER THIS IS DISCOUNTED AT THIS TIME. WILL SHOW POPS
INCREASING BY MIDDAY...SLIGHT CHANCE WEST TO CHANCE IN THE
EAST...ENDING FROM SOUTHWEST TO NORTHEAST MONDAY NIGHT AS THE
SURFACE LOW MOVES OFF TO THE NORTHEAST. THE QPF FORECAST IS FOR LESS
THAN A TENTH OF AN INCH...BUT WOULDNT BE SURPRISED TO SEE MODELS
PRODUCE MORE PRECIP IN LATER RUNS. HAVE LOWERED HIGHS A FEW DEGREES
ACROSS THE PIEDMONT BASED ON INCREASING POTENTIAL FOR
PRECIP...RANGING FROM LOWER 40S NORTHWEST TO NEAR 50 SOUTHEAST.
LOWS MONDAY NIGHT IN THE LOWER 30S NORTHEAST TO UPPER 30S SOUTHEAST.
A STRONG NORTHERN STREAM SHORTWAVE WILL DIVE ACROSS NC ON
TUESDAY....FOLLOWED BY A REINFORCING SHOT OF COLD ADVECTION TUESDAY
NIGHT. THE ECMWF SPITS OUT SOME VERY LIGHT QPF ACROSS THE NORTH
TUESDAY AFTERNOON...BUT WILL HOLD OFF ON INTRODUCING POPS AS MOISTURE
WILL BE LIMITED. HIGH PRESSURE IS THEN FORECAST TO BUILD ACROSS
THEN BUILD SLOWLY ACROSS THE SOUTHEAST BETWEEN AN UPPER LOW THAT
CLOSES OFF OVER NEW ENGLAND AND RIDGING OVER THE CENTRAL US. TEMPS
MAY SLOWLY MODERATE BUT WILL REMAIN AT OR JUST BELOW NORMAL.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 700 AM SATURDAY...
COMPLEX FORECAST FOR THIS TAF PERIOD...AND BEYOND THROUGH EARLY THIS
UPCOMING WEEK.
AN AXIS OF IFR-MVFR STRATUS WILL LIKELY SHIFT EAST OF RDU/FAY/RWI
BETWEEN 15-18Z...AS THE FLOW IN THAT LAYER VEERS FROM SOUTHERLY TO
SOUTHWESTERLY...AFTER WHICH TIME A SEVERAL HOUR PERIOD OF VFR
CONDITIONS ARE PROBABLE DURING THE MIDDAY TO EARLY AFTERNOON HOURS.
MEANWHILE...A PRE-FRONTAL BAND OF RAIN...FALLING FROM MOSTLY VFR
CEILINGS BUT PRODUCING MVFR SURFACE VISIBILITY RESTRICTIONS...WILL
MOVE EAST AND ARRIVE AT RDU AND FAY BETWEEN 14-15Z AND RWI BETWEEN
16-18Z...BASICALLY ON THE HEELS OF THE DEPARTING INITIAL BAND OF
MVFR CEILINGS. THEN YET A THIRD REGIME OF IFR-MVFR CONDITIONS AND
NUMEROUS TO WIDESPREAD SHOWERS (AND ISOLATED THUNDERSTORMS) WILL
SWEEP EAST INTO OUR AREA BETWEEN 17-19Z AT WESTERN TERMINALS TO
BETWEEN 20-23Z AT EASTERN ONES. THE PASSAGE OF A COLD FRONT AND
FOLLOWING BRISK NW BREEZE WILL HELP SCOUR AND LIFT THE CLOUD
LAYER...PARTICULARLY AT TRIAD TERMINALS THIS EVENING...THOUGH SUB-
VFR CONDITIONS AND AREAS OF LIGHT RAIN OR DRIZZLE ARE APT TO LINGER
THROUGHOUT THE NIGHT...ESPECIALLY AT RDU/RWI/FAY.
OUTLOOK: IN THE WAKE OF THE AFOREMENTIONED COLD FRONT...BRISK NNE
WINDS...AND A THREAT OF MVFR CEILINGS AT EASTERN TERMINALS...ARE
EXPECTED ON SUNDAY. WHILE FORECAST CONFIDENCE IS BELOW AVERAGE...THE
DEVELOPMENT OF A COASTAL STORM NEAR THE SOUTH AND MIDDLE ATLANTIC
COAST MAY RESULT IN A REDEVELOPMENT/SOUTHWESTWARD EXPANSION OF MVFR
CEILINGS...AND POSSIBLY RAIN...LATE SUN NIGHT-MON NIGHT.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...MWS
SHORT TERM...MWS
LONG TERM...BLS
AVIATION...MWS
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
634 AM EST SAT DEC 6 2014
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE CAROLINAS BRINGING SHOWERS TODAY
AND ISOLATED THUNDERSTORMS TONIGHT...BEFORE MOVING OFFSHORE INTO
VERY EARLY SUNDAY. STRONG HIGH PRESSURE WILL BUILD SOUTH SUNDAY
AND MONDAY...BRINGING GUSTY NORTH WINDS AND COLDER TEMPERATURES.
CANADIAN HIGH PRESSURE NEXT WEEK WILL MAINTAIN SEASONABLY COOL
TEMPERATURES AND DRY CONDITIONS.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 634 AM SATURDAY...OCEAN CONVECTION ON ITS WAY OUT AND NNE
OF THE AREA BUT LIGHTER RAINFALL KNOCKING ON OUR FAR INTERIOR DOOR
STEP. SMALL ADJUSTMENTS TO POPS TO MATCH RADAR FOR THE DAYBREAK
UPDATE AND EARLY MORNING HOURLY TEMPERATURE TRENDS WERE TWEAKED TO
REFLECT RECENT METARS...THE PREVIOUS DISCUSSION FOLLOWS WITH NO
MAJOR CHANGES TO THE FORECAST TO KICK-OFF SATURDAY.
SURFACE LOW PRECEDING AN UPPER TROUGH WAS APPROACHING THE CENTRAL
APPALACHIANS...HELPING TO LIFT A COASTAL TROUGH ONTO THE CAROLINA
COAST EARLY THIS MORNING. KLTX SENSING MODERATE CONVECTION
OFFSHORE OF CAPE FEAR MOVING NORTH TOWARD SURF CITY TO CARTERET
COUNTY TO CAPE LOOKOUT. ORGANIZED PRECIPITATION WAS ADVANCING INTO
THE WESTERN CAROLINAS. THE TRENDING WEATHER FEATURES OCEAN
CONVECTION MOVING N AND NE OF NE SC/SE NC THROUGH MORNING WHILE A
BROADER SHIELD OF -RA ENCROACHES FROM THE WEST.
A COLD FRONT WILL SWEEP OFF THE COAST LATE THIS EVENING. AHEAD OF
THE FRONT DESTABILIZATION MAY STRENGTHEN IN THE AFTERNOON IF CLOUD
BREAKS ALLOW SURFACE WARMING...OTHERWISE BEST MIXED LAYER CAPES
SPIKE AS DOES OMEGA AND COLUMN MOISTURE OVER THE AREA BETWEEN
00Z-04Z. LOW-LEVEL WINDS DO NOT APPEAR TO SUPPORT A SEVERE THREAT
AHEAD OF THE FRONT BUT WILL MAINTAIN ISOLATED TSTM MENTION.
MAXIMUM TEMPERATURES WILL NOT BE EASY SINCE BREAKS IN THE CLOUDS
COULD WARM LOCAL TEMPS QUICKLY IN THE GROWING WARM SECTOR. BREAKS
HOWEVER SHOULD NOT LAST LONG WITH PLENTIFUL UPSTREAM CLOUDS NOTED
CURRENTLY...UPPER 60S TO LOWER 70S MOST PLACES AND A LITTLE COOLER
BY THE SEA. COLD AIR ADVECTION ALREADY UNDERWAY PRIOR TO DAYBREAK
IN BRISK AND DEEP NORTH WIND FLOW...AND GUSTY. MINIMUMS BY FIRST
LIGHT SUNDAY IN THE 40S.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 AM SATURDAY...STRONG HIGH PRESSURE WILL BUILD DOWN
ACROSS THE CAROLINAS ON SUNDAY. A 1045 MB HIGH WILL MOVE ACROSS
CANADA FROM JUST NORTH OF THE GREAT LAKES TO THE CANADIAN
MARITIMES BY MONDAY. TIGHTENED GRADIENT FLOW WILL EXIST BETWEEN
THIS AREA OF HIGH PRESSURE AND LOW PRESSURE LINGERING OVER THE
DISTANT OFF SHORE WATERS OF THE CAROLINAS. EXPECT GUSTY NORTHERLY
WINDS WINDS THROUGH MUCH OF THE PERIOD. SHOULD SEE SOME CLEARING
OUT ON SUNDAY IN DRY NORTHERLY FLOW ESPECIALLY THROUGH INLAND
AREAS ALTHOUGH STRONG INVERSION COULD LOCK IN A DECENT LAYER OF
MOISTURE UNDERNEATH. CAA WILL BRING 850 TEMPS DOWN SEVERAL DEGREES
THROUGH SUNDAY INTO EARLY MONDAY. COASTAL AREAS MAY BE THE LAST
PLACE TO SEE SOME SUNSHINE ON SUNDAY AFTN. PCP WATER VALUES DROP
DOWN NEAR A QUARTER OF AN INCH INLAND WEST OF I95 BUT CLOSE TO THE
COAST VALUES REMAIN AROUND A HALF INCH UNTIL LATER ON SUNDAY.
OVERALL EXPECT TO SEE SOME SUNSHINE BY SUNDAY AFTERNOON WITH TEMPS
IN THE 50S.
MID TO UPPER TROUGH WILL DIG DOWN FROM THE GREAT LAKES ON MONDAY
PUSHING NEXT NORTHERN STREAM SYSTEM EAST. THIS WILL PUSH THE HIGH
PRESSURE OFF THE COAST OF THE CANADIAN MARITIMES LEAVING A WEDGE
OF HIGH PRESSURE DOWN THROUGH THE INLAND CAROLINAS. AT THE SAME
TIME LOW PRESSURE OFF SHORE WILL RETROGRADE BACK WEST TOWARD THE
CAROLINA COAST BEFORE LIFTING OFF TO THE NORTH MON NIGHT. THE LOW
LEVEL INVERSION WILL STRENGTHEN FURTHER AS WARMER AND MOISTER FLOW
DEVELOPS IN THE LOW LEVELS. EXPECT LOW CLOUDS AND CONTINUED COOL
CONDITIONS WITH GUSTY NORTHERLY WINDS AND TEMPS IN THE 50S ONCE
AGAIN. MOST PCP SHOULD REMAIN OFF THE COAST BUT MAY SEE SOME WORK
ITS WAY INLAND THROUGH THE DAY AS LOW MOVES UP ALONG THE CAROLINA
COAST TOWARD VA. BY MON NIGHT DIGGING MID TO UPPER TROUGH WILL
PUSH COLD FRONT EAST WHILE LOW PRESSURE LIFTS OFF TO THE NORTH.
THIS WILL SQUEEZE OUT ANY REMAINING WEDGE BY EARLY TUES.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 AM SATURDAY...DEEP MID TO UPPER TROUGH WILL PUSH
NORTHERN STREAM SYSTEM EAST AS LOW PRESSURE SYSTEM LIFTS NORTHEAST
AWAY FROM THE CAROLINAS UP ALONG THE EASTERN SEABOARD. ONCE THIS
SYSTEM SHIFTS OFF SHORE BY LATE TUES IT WILL DRY OUT THE COLUMN
IN DEEP NW FLOW. ALL THE RESIDUAL LOW LEVEL MOISTURE WILL DIMINISH
WITH DEEP DRY COLUMN IN PLACE BY WED THROUGH FRI. OVERALL EXPECT
CLEARING SKIES ON TUES WITH STRONG DRY HIGH PRESSURE BUILDING IN.
A REINFORCING SHOT OF COLD AIR WITH 850 TEMPS DROPPING DOWN BELOW
0C WILL KEEP COOL TEMPS THROUGH MID WEEK. EXPECT HIGHS IN THE 50S
MOST DAYS WITH WED BEING THE COOLEST DAY. SHOULD SEE PLENTY OF
SUNSHINE WED AND THURS.
HIGH PRESSURE WILL MOVE CLOSER OVERHEAD BY THURS INTO FRI WITH
WEAK GRADIENT MAINTAINING LIGHT WINDS ALLOWING AIR MASS TO MODIFY
AND BECOME SLIGHTLY WARMER. A SHORTWAVE IN THE MID LEVELS WILL PASS
THROUGH THURS NIGHT INTO FRI WHICH SHOULD GIVE US SOME PASSING HIGHER
CLOUDS. WILL KEEP POPS OUT OF FORECAST FOR NOW.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 00Z...RATHER LOW CONFIDENCE ON THE BACK END OF THE FORECAST
PERIOD WITH RESPECT TO CEILINGS AND THE TIMING OF PRECIP. LOOKS LIKE
THERE COULD BE TWO BATCHES OF RAIN/SHOWERS: THE FIRST AROUND SUNRISE
WITH A COASTAL TROUGH...THEN ANOTHER ROUND IN THE LATE AFTERNOON
AHEAD OF A COLD FRONT. MODELS ARE IN REASONABLE AGREEMENT
INTRODUCING IFR STRATUS/FOG AROUND DAYBREAK IF NOT BEFORE...AND THIS
MAKES SENSE GIVEN THE WEAK WARM AIR ADVECTION. THE HRRR MODEL THINKS
THAT ILM STANDS THE BEST CHANCE FOR MORNING PRECIP...BUT THE MYRTLES
COULD ALSO GET INTO THE ACT. THINK THE MORNING PRECIP WILL GIVE WAY
TO MVFR CEILINGS AND SOUTHWESTERLY FLOW AHEAD OF A COLD FRONT WHICH
WILL ARRIVE AT THE END OF THE FORECAST PERIOD.
EXTENDED OUTLOOK...PERIODS OF MVFR/IFR CIGS ARE LIKELY THROUGH THE
WEEKEND AND INTO EARLY NEXT WEEK. GUSTY NORTH WINDS SUN/MON BEHIND
THE COLD FRONT. BECOMING VFR DURING TUE. VFR WED.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 634 AM SATURDAY...WINDS AHEAD OF A COLD FRONT WILL REMAIN
RELATIVELY LIGHT TODAY...INCREASING MORE SHARPLY INTO EARLY SUNDAY
AS COLD AIR SPILLS ACROSS THE WATERS. ADVISORY SC WATERS AND GALE
WATCH NC TO BEGINS 11Z SUNDAY WITH THIS ISSUANCE. PRESENTLY NNE
WIND 10 KT AT MASONBORO BUOY AND SE 15G17KT FRYING PAN ILLUSTRATES
WELL THE COASTAL TROUGH BOUNDARY. WILL HAVE TO WATCH FOR ADVISORY
CONDITIONS EARLIER THAN PLANNED SINCE 41013 ALREADY APPROACHING 6
FT. ISOLATED TSTMS POSSIBLE TONIGHT ON THE 0-20 NM WATERS JUST
AHEAD OF THE COLD FRONT. BY DAYBREAK SUNDAY EXPECT 30 KT GUSTS.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 AM SATURDAY...GALE WATCH REMAINS IN EFFECT FOR THE NC
WATERS BEGINNING SUNDAY MORNING WITH A SMALL CRAFT ADVISORY OVER
SOUTH CAROLINA WATERS AS WINDS INCREASE THROUGH SUN INTO SUN NIGHT
20 TO 30 KTS WITH FREQUENT GUSTS TO 35 KTS OR GREATER AS STRONG
HIGH PRESSURE BUILDS DOWN INTO THE CAROLINAS. THIS TIGHTENED
GRADIENT FLOW WILL CONTINUE INTO MONDAY AS WEDGE STRENGTHENS DOWN
THROUGH INLAND CAROLINAS WHILE LOW PRESSURE LINGERS AND SHIFTS
CLOSER TO THE COAST BEFORE LIFTING OFF TO THE NORTH BY EARLY TUES.
THIS WILL MAINTAIN STRONG NORTHERLY WINDS AND HIGH SEAS. SEAS WILL
RAMP UP SUN MORNING ABOVE SCA THRESHOLDS AND PEAKING CLOSE TO 10
FT IN OUTER WATERS OVERNIGHT SUN INTO EARLY MON MORNING. OVERALL
SEAS WILL INCREASE UP TO 6 TO 10 FT SUN NIGHT SUBSIDING THROUGH
MON NIGHT AS WINDS BEGIN TO DIMINISH DOWN TO 10 TO 20 KTS.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 300 AM SATURDAY...HIGH PRESSURE WILL BUILD DOWN FROM THE
NORTHWEST THROUGH MID WEEK. THE WINDS WILL DIMINISH THROUGH TUES
INTO WED BUT DECENT COLD SURGE COULD KICK WINDS BACK UP TUES NIGHT
TO 15 TO 20 KTS AND OUTER SEAS NEAR 6 FT. OTHERWISE EXPECT WINDS
TO DROP DOWN TO 10 TO 15 KTS THROUGH THE PERIOD WITH SEAS CLOSER
TO SCA TUES BUT DROPPING DOWN THROUGH WED TO 2 TO 5 FT.
&&
.TIDES/COASTAL FLOODING...
AS OF 700 PM WEDNESDAY...THE FULL MOON IS TODAY. WE EXPECT
ELEVATED WATER LEVELS DURING THE TIME OF HIGH TIDE THROUGH THE
WEEKEND. THE MORNING HIGH TIDE WILL BE HIGHEST AND THIS IS WHEN WE
EXPECT THE TIDE TO COME UP WELL ONTO THE BEACH. STRONG NNE WINDS
SUNDAY AND SUNDAY NIGHT WILL HELP TO ENHANCE THE ASTRONOMICAL
EFFECTS. THE LOWER CAPE FEAR RIVER WILL ALSO EXPERIENCE HIGHER THAN
PREDICTED WATER LEVELS AND MAY REACH COASTAL FLOOD ADVISORY CRITERIA
DURING THE MORNING HIGH TIDE THROUGH THE WEEKEND.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM SUNDAY TO 6 AM EST MONDAY FOR
AMZ254-256.
GALE WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY NIGHT FOR
AMZ250-252.
&&
$$
NEAR TERM...MJC
SHORT TERM...RGZ
LONG TERM...RGZ
AVIATION...MJC
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
425 AM EST SAT DEC 6 2014
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE CAROLINAS BRINGING SHOWERS TODAY AND
ISOLATED THUNDERSTORMS TONIGHT BEFORE REACHING OFF SHORE OVERNIGHT. A
STRONG WEDGE OF HIGH PRESSURE WILL BUILD SOUTH SUNDAY AND
MONDAY...BRINGING GUSTY NORTH WINDS AND MUCH COOLER TEMPERATURES.
CANADIAN HIGH PRESSURE NEXT WEEK WILL MAINTAIN SEASONABLY COOL
TEMPERATURES AND DRY CONDITIONS.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 4 AM SATURDAY...SURFACE LOW PRECEDING AN UPPER TROUGH WAS
APPROACHING THE CENTRAL APPALACHIANS...HELPING TO LIFT A COASTAL
TROUGH ONTO THE CAROLINA COAST EARLY THIS MORNING. KLTX SENSING
MODERATE CONVECTION OFFSHORE OF CAPE FEAR MOVING NORTH TOWARD SURF
CITY TO CARTERET COUNTY TO CAPE LOOKOUT. ORGANIZED PRECIPITATION
WAS ADVANCING INTO THE WESTERN CAROLINAS. THE TRENDING WEATHER
FEATURES OCEAN CONVECTION MOVING N AND NE OF NE SC/SE NC THROUGH
MORNING WHILE A BROADER SHIELD OF -RA ENCROACHES FROM THE WEST.
A COLD FRONT WILL SWEEP OFF THE COAST LATE THIS EVENING. AHEAD OF
THE FRONT DESTABILIZATION MAY STRENGTHEN IN THE AFTERNOON IF CLOUD
BREAKS ALLOW SURFACE WARMING...OTHERWISE BEST MIXED LAYER CAPES
SPIKE AS DOES OMEGA AND COLUMN MOISTURE OVER THE AREA BETWEEN
00Z-04Z. LOW-LEVELS WIND DO NOT APPEAR TO SUPPORT A SEVERE THREAT
AHEAD OF THE FRONT BUT WILL MAINTAIN ISOLATED TSTM MENTION.
MAXIMUM TEMPERATURES WILL NOT BE EASY SINCE BREAKS IN THE CLOUDS
COULD WARM LOCAL TEMPS QUICKLY IN THE GROWING WARM SECTOR. BREAKS
HOWEVER SHOULD NOT LAST LONG WITH PLENTIFUL UPSTREAM CLOUDS NOTED
CURRENTLY...UPPER 60S TO LOWER 70S MOST PLACES AND A LITTLE COOLER
BY THE SEA. COLD AIR ADVECTION ALREADY UNDERWAY PRIOR TO DAYBREAK
IN BRISK AND DEEP NORTH WIND FLOW...AND GUSTY. MINIMUMS BY FIRST
LIGHT SUNDAY IN THE 40S.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 AM SATURDAY...STRONG HIGH PRESSURE WILL BUILD DOWN
ACROSS THE CAROLINAS ON SUNDAY. A 1045 MB HIGH WILL MOVE ACROSS
CANADA FROM JUST NORTH OF THE GREAT LAKES TO THE CANADIAN
MARITIMES BY MONDAY. TIGHTENED GRADIENT FLOW WILL EXIST BETWEEN
THIS AREA OF HIGH PRESSURE AND LOW PRESSURE LINGERING OVER THE
DISTANT OFF SHORE WATERS OF THE CAROLINAS. EXPECT GUSTY NORTHERLY
WINDS WINDS THROUGH MUCH OF THE PERIOD. SHOULD SEE SOME CLEARING
OUT ON SUNDAY IN DRY NORTHERLY FLOW ESPECIALLY THROUGH INLAND
AREAS ALTHOUGH STRONG INVERSION COULD LOCK IN A DECENT LAYER OF
MOISTURE UNDERNEATH. CAA WILL BRING 850 TEMPS DOWN SEVERAL DEGREES
THROUGH SUNDAY INTO EARLY MONDAY. COASTAL AREAS MAY BE THE LAST
PLACE TO SEE SOME SUNSHINE ON SUNDAY AFTN. PCP WATER VALUES DROP
DOWN NEAR A QUARTER OF AN INCH INLAND WEST OF I95 BUT CLOSE TO THE
COAST VALUES REMAIN AROUND A HALF INCH UNTIL LATER ON SUNDAY.
OVERALL EXPECT TO SEE SOME SUNSHINE BY SUNDAY AFTERNOON WITH TEMPS
IN THE 50S.
MID TO UPPER TROUGH WILL DIG DOWN FROM THE GREAT LAKES ON MONDAY
PUSHING NEXT NORTHERN STREAM SYSTEM EAST. THIS WILL PUSH THE HIGH
PRESSURE OFF THE COAST OF THE CANADIAN MARITIMES LEAVING A WEDGE
OF HIGH PRESSURE DOWN THROUGH THE INLAND CAROLINAS. AT THE SAME
TIME LOW PRESSURE OFF SHORE WILL RETROGRADE BACK WEST TOWARD THE
CAROLINA COAST BEFORE LIFTING OFF TO THE NORTH MON NIGHT. THE LOW
LEVEL INVERSION WILL STRENGTHEN FURTHER AS WARMER AND MOISTER FLOW
DEVELOPS IN THE LOW LEVELS. EXPECT LOW CLOUDS AND CONTINUED COOL
CONDITIONS WITH GUSTY NORTHERLY WINDS AND TEMPS IN THE 50S ONCE
AGAIN. MOST PCP SHOULD REMAIN OFF THE COAST BUT MAY SEE SOME WORK
ITS WAY INLAND THROUGH THE DAY AS LOW MOVES UP ALONG THE CAROLINA
COAST TOWARD VA. BY MON NIGHT DIGGING MID TO UPPER TROUGH WILL
PUSH COLD FRONT EAST WHILE LOW PRESSURE LIFTS OFF TO THE NORTH.
THIS WILL SQUEEZE OUT ANY REMAINING WEDGE BY EARLY TUES.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 AM SATURDAY...DEEP MID TO UPPER TROUGH WILL PUSH
NORTHERN STREAM SYSTEM EAST AS LOW PRESSURE SYSTEM LIFTS NORTHEAST
AWAY FROM THE CAROLINAS UP ALONG THE EASTERN SEABOARD. ONCE THIS
SYSTEM SHIFTS OFF SHORE BY LATE TUES IT WILL DRY OUT THE COLUMN
IN DEEP NW FLOW. ALL THE RESIDUAL LOW LEVEL MOISTURE WILL DIMINISH
WITH DEEP DRY COLUMN IN PLACE BY WED THROUGH FRI. OVERALL EXPECT
CLEARING SKIES ON TUES WITH STRONG DRY HIGH PRESSURE BUILDING IN.
A REINFORCING SHOT OF COLD AIR WITH 850 TEMPS DROPPING DOWN BELOW
0C WILL KEEP COOL TEMPS THROUGH MID WEEK. EXPECT HIGHS IN THE 50S
MOST DAYS WITH WED BEING THE COOLEST DAY. SHOULD SEE PLENTY OF
SUNSHINE WED AND THURS.
HIGH PRESSURE WILL MOVE CLOSER OVERHEAD BY THURS INTO FRI WITH
WEAK GRADIENT MAINTAINING LIGHT WINDS ALLOWING AIR MASS TO MODIFY
AND BECOME SLIGHTLY WARMER. A SHORTWAVE IN THE MID LEVELS WILL PASS
THROUGH THURS NIGHT INTO FRI WHICH SHOULD GIVE US SOME PASSING HIGHER
CLOUDS. WILL KEEP POPS OUT OF FORECAST FOR NOW.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 00Z...RATHER LOW CONFIDENCE ON THE BACK END OF THE FORECAST
PERIOD WITH RESPECT TO CEILINGS AND THE TIMING OF PRECIP. LOOKS LIKE
THERE COULD BE TWO BATCHES OF RAIN/SHOWERS: THE FIRST AROUND SUNRISE
WITH A COASTAL TROUGH...THEN ANOTHER ROUND IN THE LATE AFTERNOON
AHEAD OF A COLD FRONT. MODELS ARE IN REASONABLE AGREEMENT
INTRODUCING IFR STRATUS/FOG AROUND DAYBREAK IF NOT BEFORE...AND THIS
MAKES SENSE GIVEN THE WEAK WARM AIR ADVECTION. THE HRRR MODEL THINKS
THAT ILM STANDS THE BEST CHANCE FOR MORNING PRECIP...BUT THE MYRTLES
COULD ALSO GET INTO THE ACT. THINK THE MORNING PRECIP WILL GIVE WAY
TO MVFR CEILINGS AND SOUTHWESTERLY FLOW AHEAD OF A COLD FRONT WHICH
WILL ARRIVE AT THE END OF THE FORECAST PERIOD.
EXTENDED OUTLOOK...PERIODS OF MVFR/IFR CIGS ARE LIKELY THROUGH THE
WEEKEND AND INTO EARLY NEXT WEEK. GUSTY NORTH WINDS SUN/MON BEHIND
THE COLD FRONT. BECOMING VFR DURING TUE. VFR WED.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 4 AM SATURDAY...WINDS AHEAD OF A COLD FRONT WILL REMAIN
RELATIVELY LIGHT TODAY...INCREASING MORE SHARPLY INTO EARLY SUNDAY
AS COLD AIR SPILLS ACROSS THE WATERS. ADVISORY SC WATERS AND GALE
WATCH NC TO BEGINS 11Z SUNDAY WITH THIS ISSUANCE. PRESENTLY NNE
WIND 10 KT AT MASONBORO BUOY AND SE 15G17KT FRYING PAN ILLUSTRATES
WELL THE COASTAL TROUGH BOUNDARY. WILL HAVE TO WATCH FOR ADVISORY
CONDITIONS EARLIER THAN PLANNED SINCE 41013 ALREADY APPROACHING 6
FT. ISOLATED TSTMS POSSIBLE TONIGHT ON THE 0-20 NM WATERS JUST
AHEAD OF THE COLD FRONT. BY DAYBREAK SUNDAY EXPECT 30 KT GUSTS.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 AM SATURDAY...GALE WATCH REMAINS IN EFFECT FOR THE NC
WATERS BEGINNING SUNDAY MORNING WITH A SMALL CRAFT ADVISORY OVER
SOUTH CAROLINA WATERS AS WINDS INCREASE THROUGH SUN INTO SUN NIGHT
20 TO 30 KTS WITH FREQUENT GUSTS TO 35 KTS OR GREATER AS STRONG
HIGH PRESSURE BUILDS DOWN INTO THE CAROLINAS. THIS TIGHTENED
GRADIENT FLOW WILL CONTINUE INTO MONDAY AS WEDGE STRENGTHENS DOWN
THROUGH INLAND CAROLINAS WHILE LOW PRESSURE LINGERS AND SHIFTS
CLOSER TO THE COAST BEFORE LIFTING OFF TO THE NORTH BY EARLY TUES.
THIS WILL MAINTAIN STRONG NORTHERLY WINDS AND HIGH SEAS. SEAS WILL
RAMP UP SUN MORNING ABOVE SCA THRESHOLDS AND PEAKING CLOSE TO 10
FT IN OUTER WATERS OVERNIGHT SUN INTO EARLY MON MORNING. OVERALL
SEAS WILL INCREASE UP TO 6 TO 10 FT SUN NIGHT SUBSIDING THROUGH
MON NIGHT AS WINDS BEGIN TO DIMINISH DOWN TO 10 TO 20 KTS.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 300 AM SATURDAY...HIGH PRESSURE WILL BUILD DOWN FROM THE
NORTHWEST THROUGH MID WEEK. THE WINDS WILL DIMINISH THROUGH TUES
INTO WED BUT DECENT COLD SURGE COULD KICK WINDS BACK UP TUES NIGHT
TO 15 TO 20 KTS AND OUTER SEAS NEAR 6 FT. OTHERWISE EXPECT WINDS
TO DROP DOWN TO 10 TO 15 KTS THROUGH THE PERIOD WITH SEAS CLOSER
TO SCA TUES BUT DROPPING DOWN THROUGH WED TO 2 TO 5 FT.
&&
.TIDES/COASTAL FLOODING...
AS OF 700 PM WEDNESDAY...THE FULL MOON IS TODAY. WE EXPECT
ELEVATED WATER LEVELS DURING THE TIME OF HIGH TIDE THROUGH THE
WEEKEND. THE MORNING HIGH TIDE WILL BE HIGHEST AND THIS IS WHEN WE
EXPECT THE TIDE TO COME UP WELL ONTO THE BEACH. STRONG NNE WINDS
SUNDAY AND SUNDAY NIGHT WILL HELP TO ENHANCE THE ASTRONOMICAL
EFFECTS. THE LOWER CAPE FEAR RIVER WILL ALSO EXPERIENCE HIGHER THAN
PREDICTED WATER LEVELS AND MAY REACH COASTAL FLOOD ADVISORY CRITERIA
DURING THE MORNING HIGH TIDE THROUGH THE WEEKEND.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM SUNDAY TO 6 AM EST MONDAY FOR
AMZ254-256.
GALE WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY NIGHT FOR
AMZ250-252.
&&
$$
NEAR TERM...MJC
SHORT TERM...RGZ
LONG TERM...RGZ
AVIATION...MJC/DL
AREA FORECAST DISCUSSION
NWS RALEIGH NC
344 AM EST SAT DEC 6 2014
.SYNOPSIS...A SHORTWAVE TROUGH INITIALLY OVER THE MID MS AND TN
VALLEYS WILL AMPLIFY ACROSS THE SOUTHERN APPALACHIANS AND CAROLINAS
THROUGH TONIGHT. AN ACCOMPANYING SURFACE LOW OVER THE LOWER OH AND
TN VALLEY WILL RE-DEVELOP OVER VA/NC TODAY...THEN BEGIN TO INTENSIFY
AS IT APPROACHES A COASTAL FRONT ALONG THE NC COAST THIS EVENING-
TONIGHT. MEANWHILE...ARCTIC HIGH PRESSURE WILL STRENGTHEN AS IT
MIGRATES FROM THE NORTHERN PLAINS TO NEW ENGLAND...THE SOUTHERN
PERIPHERY OF WHICH WILL RIDGE SOUTH INTO NC LATE TONIGHT THROUGH
SUNDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM SATURDAY...
A COASTAL FRONT ALONG THE SOUTHEAST AND MIDDLE ATLANTIC COASTS HAS
CAUSED A PIECE OF THE 1040 MB MODIFIED ARCTIC CENTERED NEAR
NEWFOUNDLAND TO BREAK OFF OVER THE CAROLINAS THIS MORNING...AND THIS
1027 MB HIGH WILL LIKELY ESTABLISH A SHORT-LIVED IN-SITU CAD EVENT
OVER AT LEAST THE WESTERN PIEDMONT TODAY. WHETHER OR NOT THE WEDGE
IS ESTABLISHED EAST ACROSS THE REMAINDER OF CENTRAL NC IS MORE IN
QUESTION...SINCE IT SEEMS THE UPSTREAM PRE-FRONTAL BAND OF RAIN NOW
CROSSING THE SOUTHERN-CENTRAL APPALACHIANS HAS BEEN FALLING MOSTLY
FROM MID LEVEL CEILINGS...AND AS SUCH...WOULD MAKE IT LESS LIKELY TO
FULLY SATURATE THE LOW LEVELS AND HELP ESTABLISH A WEDGE. IN
FACT...BOTH THE RAP AND HRRR SUGGEST THE INITIAL BAND OF IFR-MVFR
CEILINGS CENTERED FROM NEAR CAE TO RDU TO RIC THIS MORNING WILL
DRIFT EAST THROUGH MIDDAY...AND PROVIDE FOR A PERIOD OF MOSTLY MID-
HIGH LEVEL CLOUDS AND MODEST INSOLATION DURING THE MIDDAY-EARLY
AFTERNOON HOURS. THE MAIN SENSIBLE WEATHER IMPACT WITH THIS
UNCERTAINTY REGARDS TEMPERATURES...WHICH WOULD BE HELD IN THE MID-
UPPER 40S OVER THE NW PIEDMONT (SIMILAR TO FRI) TO GENERALLY MID 50S
ELSEWHERE. BASED ON UPSTREAM OBSERVATIONS OF RAIN FROM MOSTLY MID
CLOUDS...WILL TREND HIGH TEMPS TOWARD SOME MODEST INSOLATION...WITH
HIGHS RANGING FROM THE MIDDLE 50S TO NEAR 60 DEGREES...EXCEPT AROUND
50 DEGREES OR SO IN THE WESTERN PIEDMONT WHERE THE OPPORTUNITY FOR
INSOLATION WILL BE MORE LIMITED BETWEEN THE PRE-FRONTAL RAIN
BAND...AND A TRAILING SEPARATE AREA OF SHALLOW CONVECTIVE
PRECIPITATION FORECAST TO MOVE ACROSS THE AREA LATER THIS AFTERNOON.
THAT TRAILING PRECIPITATION WILL BE FUELED BY SUBSTANTIAL COOLING
ALOFT ACCOMPANYING A PARENT SHORTWAVE TROUGH ALOFT...ATOP A WARM AND
MOIST...40 KT LLJ. THE ASSOCIATED STRONG DIFFERENTIAL THERMAL
ADVECTION WILL CAUSE H85-5 LAPSE RATES TO STEEPEN IN EXCESS OF 6.5
C/KM OVER CENTRAL NC...COINCIDENT WITH 50-80 METER MID LEVEL HEIGHT
FALLS ACCOMPANYING THE PARENT SHORTWAVE TROUGH ALOFT. FORECAST
GUIDANCE CONTINUES TO SUGGEST THAT A POCKET OF UP TO A FEW HUNDRED
J/KG OF MUCAPE WILL CONSEQUENTLY DEVELOP OVER OUR AREA THIS
AFTERNOON...WHICH WILL SUPPORT THE EASTWARD PROGRESSION AND/OR RE-
DEVELOPMENT OF NUMEROUS TO WIDESPREAD SHOWERS AND ISOLATED
THUNDERSTORMS ACROSS CENTRAL NC THIS AFTERNOON.
THOUGH SHOWERS AND ISOLATED STORMS WILL MOVE EAST WITH THE PASSAGE
OF A THE OCCLUDED/COLD FRONT THIS EVENING...THE DEEPENING OF A
SURFACE LOW AS IT ENCOUNTERS THE COASTAL FRONT WILL MAINTAIN A MOIST
NNE FLOW THAT WILL LIKELY RESULT IN CONSIDERABLE LOW OVERCAST AND
AREAS OF LIGHT RAIN OR DRIZZLE...WHICH WILL ONLY SLOWLY EDGE
EASTWARD THROUGH SUN MORNING...PARTICULARLY OVER THE EASTERN TWO
THIRDS OF THE CWFA. LOWS MOSTLY IN THE LOWER TO MIDDLE 40S.
&&
.SHORT TERM /SUNDAY AND SUNDAY NIGHT/...
AS OF 340 AM SATURDAY...
SUNDAY AND SUNDAY NIGHT: BRIEF SHORTWAVE RIDGING WILL BUILD EAST
ACROSS OUR REGION AND CAUSE STRONG ARCTIC HIGH PRESSURE CENTERED
OVER NEW ENGLAND TO RIDGE DOWN THE EAST COAST THIS PERIOD...IN
ADVANCE OF A PAIR OF PHASED (OR NEARLY SO) SHORTWAVE TROUGHS
FORECAST TO AMPLIFY FROM THE PLAINS TO THE MS VALLEY THROUGH SUN
NIGHT. DESPITE MAINLY CLEAR SKIES...EXCEPT SOME LINGERING LOW CLOUDS
OVER EASTERN NC...A BRISK AND GUSTY NE WIND WILL RESULT IN RATHER
CHILLY CONDITIONS...WITH HIGHS MOSTLY IN THE MID-UPPER 40S (TO NEAR
50 SOUTH). THE AMPLIFICATION OF THE AFOREMENTIONED TROUGHS ALOFT
WILL CAUSE THE LOW LEVEL FLOW (925 MB) TO ASSUME AN INCREASINGLY
EASTERLY COMPONENT (TOWARD THE PRESSURE FALLS ACCOMPANYING HE
APPROACHING TROUGH)..SUCH THAT THE LOW CLOUDS OVER THE EASTERN PART
OF THE STATE WILL DEVELOP/ADVECT WSW ACROSS CENTRAL NC THROUGH MON
MORNING. LOWS CENTERED IN THE MIDDLE 30S.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 335 AM SATURDAY...
CONFIDENCE IS LOWER THAN DESIRED FOR A DAY 3 (MONDAY) FORECAST DUE
TO MODEL DIFFERENCES REGARDING THE INTERACTION OF NORTHERN AND
SOUTHERN STREAM SHORTWAVES AS THEY CROSS THE CENTRAL AND EASTERN US.
MODELS HAVE BEEN COMING INTO A LITTLE BETTER AGREEMENT...SHOWING THE
LEAD SOUTHERN STREAM SHORTWAVE MOVING FROM THE DEEP SOUTH ACROSS THE
CAROLINAS ON MONDAY...WITH A NORTHERN STREAM WAVE TO DIVE SOUTH
ACROSS THE REGION ON TUESDAY. IN RESPONSE TO THE LEAD WAVE...A
SURFACE LOW OFF THE SOUTHEAST COAST WILL RE-INTENSIFY AND LIFT NORTH
ALONG THE EAST COAST. THE NAM AND CANADIAN ARE STRONG OUTLIERS
REGARDING THE STRENGTH OF THE LOW AND ASSOCIATED PRECEDING EASTERLY
FLOW...PRODUCING HEAVIER PRECIP EARLIER ON MONDAY. THE ECMWF IS A
LITTLE MORE AMPLIFIED WITH THE LEAD WAVE...RESULTING MORE PRECIP
THAN THE GFS...BUT STILL RELATIVELY LIGHT AND NOT UNTIL MONDAY
AFTERNOON. THIS HAS SOME SIGNIFICANCE...AS A STRONG 1040+ MB
SURFACE HIGH EXTENDING INTO THE NC FROM NEW ENGLAND WILL BE
RETREATING DURING THE DAY BUT WOULD OFFER SOME PTYPE CONCERNS IN THE
NORTHWEST PIEDMONT WITH PRECIP EARLY MONDAY MORNING...AS THE NAM
DEPICTS. HOWEVER THIS IS DISCOUNTED AT THIS TIME. WILL SHOW POPS
INCREASING BY MIDDAY...SLIGHT CHANCE WEST TO CHANCE IN THE
EAST...ENDING FROM SOUTHWEST TO NORTHEAST MONDAY NIGHT AS THE
SURFACE LOW MOVES OFF TO THE NORTHEAST. THE QPF FORECAST IS FOR LESS
THAN A TENTH OF AN INCH...BUT WOULDNT BE SURPRISED TO SEE MODELS
PRODUCE MORE PRECIP IN LATER RUNS. HAVE LOWERED HIGHS A FEW DEGREES
ACROSS THE PIEDMONT BASED ON INCREASING POTENTIAL FOR
PRECIP...RANGING FROM LOWER 40S NORTHWEST TO NEAR 50 SOUTHEAST.
LOWS MONDAY NIGHT IN THE LOWER 30S NORTHEAST TO UPPER 30S SOUTHEAST.
A STRONG NORTHERN STREAM SHORTWAVE WILL DIVE ACROSS NC ON
TUESDAY....FOLLOWED BY A REINFORCING SHOT OF COLD ADVECTION TUESDAY
NIGHT. THE ECMWF SPITS OUT SOME VERY LIGHT QPF ACROSS THE NORTH
TUESDAY AFTERNOON...BUT WILL HOLD OFF ON INTRODUCING POPS AS MOISTURE
WILL BE LIMITED. HIGH PRESSURE IS THEN FORECAST TO BUILD ACROSS
THEN BUILD SLOWLY ACROSS THE SOUTHEAST BETWEEN AN UPPER LOW THAT
CLOSES OFF OVER NEW ENGLAND AND RIDGING OVER THE CENTRAL US. TEMPS
MAY SLOWLY MODERATE BUT WILL REMAIN AT OR JUST BELOW NORMAL.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 145 AM SATURDAY...
COMPLEX FORECAST FOR THIS TAF PERIOD...AND BEYOND THROUGH EARLY THIS
UPCOMING WEEK.
AN AXIS OF IFR-MVFR STRATUS HAS DEVELOPED AND SPREAD DIRECTLY ACROSS
THE CENTRAL CAROLINAS THIS MORNING...CENTERED FROM NEAR CAE TO RDU
TO TDF...OR JUST EAST OF THE TRIAD TERMINALS AND JUST WEST OF FAY.
THIS CLOUD BAND IS FORECAST TO HOLD RELATIVELY STATIONARY THROUGH
12Z...BEFORE SHIFTING EAST TOWARD RWI THROUGH 18Z. MEANWHILE...A PRE-
FRONTAL BAND OF RAIN AND OCCASIONAL IFR-MVFR CONDITIONS...AMIDST
OTHERWISE LOW VFR CEILINGS...WILL ARRIVE FROM THE WEST BETWEEN 10-
12Z AT WESTERN TERMINALS TO 14-17Z AT EASTERN ONES...BASICALLY ON
THE HEELS OF THE DEPARTING INITIAL BAND OF MVFR CEILINGS. THEN YET A
THIRD REGIME OF IFR-MVFR CONDITIONS AND NUMEROUS TO WIDESPREAD
SHOWERS (AND ISOLATED THUNDERSTORMS) WILL SWEEP EAST INTO OUR AREA
BETWEEN 17-19Z AT WESTERN TERMINALS TO BETWEEN 20-22Z AT EASTERN
ONES. THE PASSAGE OF A COLD FRONT AND FOLLOWING WNW BREEZE WILL HELP
SCOUR AND LIFT THE CLOUD LAYER...PARTICULARLY AT TRIAD TERMINALS
THIS EVENING...THOUGH SUB-VFR CONDITIONS AND AREAS OF LIGHT RAIN OR
DRIZZLE ARE APT TO LINGER THROUGHOUT THE NIGHT...ESPECIALLY AT
RDU/RWI/FAY.
OUTLOOK: IN THE WAKE OF THE AFOREMENTIONED COLD FRONT...BRISK NNE
WINDS...AND A THREAT OF MVFR CEILINGS AT EASTERN TERMINALS...ARE
EXPECTED ON SUNDAY. WHILE FORECAST CONFIDENCE IS BELOW AVERAGE...THE
DEVELOPMENT OF A COASTAL STORM NEAR THE SOUTH AND MIDDLE ATLANTIC
COAST MAY RESULT IN A REDEVELOPMENT/SOUTHWESTWARD EXPANSION OF MVFR
CEILINGS...AND POSSIBLY RAIN...LATE SUN NIGHT-MON NIGHT.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...MWS
SHORT TERM...MWS
LONG TERM...BLS
AVIATION...MWS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
335 AM EST SAT DEC 6 2014
.SYNOPSIS...A SHORTWAVE TROUGH INITIALLY OVER THE MID MS AND TN
VALLEYS WILL AMPLIFY ACROSS THE SOUTHERN APPALACHIANS AND CAROLINAS
THROUGH TONIGHT. AN ACCOMPANYING SURFACE LOW OVER THE LOWER OH AND
TN VALLEY WILL RE-DEVELOP OVER VA/NC TODAY...THEN BEGIN TO INTENSIFY
AS IT APPROACHES A COASTAL FRONT ALONG THE NC COAST THIS EVENING-
TONIGHT. MEANWHILE...ARCTIC HIGH PRESSURE WILL STRENGTHEN AS IT
MIGRATES FROM THE NORTHERN PLAINS TO NEW ENGLAND...THE SOUTHERN
PERIPHERY OF WHICH WILL RIDGE SOUTH INTO NC LATE TONIGHT THROUGH
SUNDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM SATURDAY...
A COASTAL FRONT ALONG THE SOUTHEAST AND MIDDLE ATLANTIC COASTS HAS
CAUSED A PIECE OF THE 1040 MB MODIFIED ARCTIC CENTERED NEAR
NEWFOUNDLAND TO BREAK OFF OVER THE CAROLINAS THIS MORNING...AND THIS
1027 MB HIGH WILL LIKELY ESTABLISH A SHORT-LIVED IN-SITU CAD EVENT
OVER AT LEAST THE WESTERN PIEDMONT TODAY. WHETHER OR NOT THE WEDGE
IS ESTABLISHED EAST ACROSS THE REMAINDER OF CENTRAL NC IS MORE IN
QUESTION...SINCE IT SEEMS THE UPSTREAM PRE-FRONTAL BAND OF RAIN NOW
CROSSING THE SOUTHERN-CENTRAL APPALACHIANS HAS BEEN FALLING MOSTLY
FROM MID LEVEL CEILINGS...AND AS SUCH...WOULD MAKE IT LESS LIKELY TO
FULLY SATURATE THE LOW LEVELS AND HELP ESTABLISH A WEDGE. IN
FACT...BOTH THE RAP AND HRRR SUGGEST THE INITIAL BAND OF IFR-MVFR
CEILINGS CENTERED FROM NEAR CAE TO RDU TO RIC THIS MORNING WILL
DRIFT EAST THROUGH MIDDAY...AND PROVIDE FOR A PERIOD OF MOSTLY MID-
HIGH LEVEL CLOUDS AND MODEST INSOLATION DURING THE MIDDAY-EARLY
AFTERNOON HOURS. THE MAIN SENSIBLE WEATHER IMPACT WITH THIS
UNCERTAINTY REGARDS TEMPERATURES...WHICH WOULD BE HELD IN THE MID-
UPPER 40S OVER THE NW PIEDMONT (SIMILAR TO FRI) TO GENERALLY MID 50S
ELSEWHERE. BASED ON UPSTREAM OBSERVATIONS OF RAIN FROM MOSTLY MID
CLOUDS...WILL TREND HIGH TEMPS TOWARD SOME MODEST INSOLATION...WITH
HIGHS RANGING FROM THE MIDDLE 50S TO NEAR 60 DEGREES...EXCEPT AROUND
50 DEGREES OR SO IN THE WESTERN PIEDMONT WHERE THE OPPORTUNITY FOR
INSOLATION WILL BE MORE LIMITED BETWEEN THE PRE-FRONTAL RAIN
BAND...AND A TRAILING SEPARATE AREA OF SHALLOW CONVECTIVE
PRECIPITATION FORECAST TO MOVE ACROSS THE AREA LATER THIS AFTERNOON.
THAT TRAILING PRECIPITATION...WILL BE FUELED BY SUBSTANTIAL COOLING
ALOFT ACCOMPANYING A PARENT SHORTWAVE TROUGH ALOFT...ATOP A WARM AND
MOIST...40 KT LLJ. THE ASSOCIATED STRONG DIFFERENTIAL THERMAL
ADVECTION WILL CAUSE H85-5 LAPSE RATES TO STEEPEN IN EXCESS OF 6.5
C/KM OVER CENTRAL NC...COINCIDENT WITH 50-80 METER MID LEVEL HEIGHT
FALLS ACCOMPANYING THE PARENT SHORTWAVE TROUGH ALOFT. FORECAST
GUIDANCE CONTINUES TO SUGGEST THAT A POCKET OF UP TO A FEW HUNDRED
J/KG OF MUCAPE WILL CONSEQUENTLY DEVELOP OVER OUR AREA THIS
AFTERNOON...WHICH WILL SUPPORT THE EASTWARD PROGRESSION AND/OR RE-
DEVELOPMENT OF NUMEROUS TO WIDESPREAD SHOWERS AND ISOLATED
THUNDERSTORMS ACROSS CENTRAL NC THIS AFTERNOON.
THOUGH SHOWERS AND ISOLATED STORMS WILL MOVE EAST WITH THE PASSAGE
OF A THE OCCLUDED/COLD FRONT THIS EVENING...THE DEEPENING OF A
SURFACE LOW AS IT ENCOUNTERS THE COASTAL FRONT WILL MAINTAIN A MOIST
NNE FLOW THAT WILL LIKELY RESULT IN CONSIDERABLE LOW OVERCAST AND
AREAS OF LIGHT RAIN OR DRIZZLE...WHICH WILL ONLY SLOWLY EDGE
EASTWARD THROUGH SUN MORNING...PARTICULARLY OVER THE EASTERN TWO
THIRDS OF THE CWFA. LOWS MOSTLY IN THE LOWER TO MIDDLE 40S.
&&
.SHORT TERM /SUNDAY AND SUNDAY NIGHT/...
AS OF 220 PM FRIDAY...
SUNDAY AND SUNDAY NIGHT: THE LATEST RUN OF THE ECMWF AGREES WELL
WITH THE GFS IN REGARD TO THE LOW AND ITS ASSOCIATED COLD FRONT
MOVING OFF THE CAROLINA COAST PRIOR TO 12Z SUNDAY. AS SUCH...HAVE A
DRY FORECAST FOR SUNDAY AND SUNDAY NIGHT. THE BIG QUESTION WILL BE
HOW QUICKLY THE SKIES CLEAR AND HOW THAT WILL AFFECT TEMPERATURES.
FOR NOW...EXPECT HIGHS IN THE UPPER 40S NW TO 723MID 50S SOUTH AND
EAST...ALTHOUGH IF SKIES CLEAR QUICKER/SLOWER THAT COULD CHANGE BY A
COUPLE/FEW DEGREES. LOWS GENERALLY IN LOW 30S NW TO UPPER 30S SE.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 335 AM SATURDAY...
CONFIDENCE IS LOWER THAN DESIRED FOR A DAY 3 (MONDAY) FORECAST DUE
TO MODEL DIFFERENCES REGARDING THE INTERACTION OF NORTHERN AND
SOUTHERN STREAM SHORTWAVES AS THEY CROSS THE CENTRAL AND EASTERN US.
MODELS HAVE BEEN COMING INTO A LITTLE BETTER AGREEMENT...SHOWING THE
LEAD SOUTHERN STREAM SHORTWAVE MOVING FROM THE DEEP SOUTH ACROSS THE
CAROLINAS ON MONDAY...WITH A NORTHERN STREAM WAVE TO DIVE SOUTH
ACROSS THE REGION ON TUESDAY. IN RESPONSE TO THE LEAD WAVE...A
SURFACE LOW OFF THE SOUTHEAST COAST WILL RE-INTENSIFY AND LIFT NORTH
ALONG THE EAST COAST. THE NAM AND CANADIAN ARE STRONG OUTLIERS
REGARDING THE STRENGTH OF THE LOW AND ASSOCIATED PRECEDING EASTERLY
FLOW...PRODUCING HEAVIER PRECIP EARLIER ON MONDAY. THE ECMWF IS A
LITTLE MORE AMPLIFIED WITH THE LEAD WAVE...RESULTING MORE PRECIP
THAN THE GFS...BUT STILL RELATIVELY LIGHT AND NOT UNTIL MONDAY
AFTERNOON. THIS HAS SOME SIGNIFICANCE...AS A STRONG 1040+ MB
SURFACE HIGH EXTENDING INTO THE NC FROM NEW ENGLAND WILL BE
RETREATING DURING THE DAY BUT WOULD OFFER SOME PTYPE CONCERNS IN THE
NORTHWEST PIEDMONT WITH PRECIP EARLY MONDAY MORNING...AS THE NAM
DEPICTS. HOWEVER THIS IS DISCOUNTED AT THIS TIME. WILL SHOW POPS
INCREASING BY MIDDAY...SLIGHT CHANCE WEST TO CHANCE IN THE
EAST...ENDING FROM SOUTHWEST TO NORTHEAST MONDAY NIGHT AS THE
SURFACE LOW MOVES OFF TO THE NORTHEAST. THE QPF FORECAST IS FOR LESS
THAN A TENTH OF AN INCH...BUT WOULDNT BE SURPRISED TO SEE MODELS
PRODUCE MORE PRECIP IN LATER RUNS. HAVE LOWERED HIGHS A FEW DEGREES
ACROSS THE PIEDMONT BASED ON INCREASING POTENTIAL FOR
PRECIP...RANGING FROM LOWER 40S NORTHWEST TO NEAR 50 SOUTHEAST.
LOWS MONDAY NIGHT IN THE LOWER 30S NORTHEAST TO UPPER 30S SOUTHEAST.
A STRONG NORTHERN STREAM SHORTWAVE WILL DIVE ACROSS NC ON
TUESDAY....FOLLOWED BY A REINFORCING SHOT OF COLD ADVECTION TUESDAY
NIGHT. THE ECMWF SPITS OUT SOME VERY LIGHT QPF ACROSS THE NORTH
TUESDAY AFTERNOON...BUT WILL HOLD OFF ON INTRODUCING POPS AS MOISTURE
WILL BE LIMITED. HIGH PRESSURE IS THEN FORECAST TO BUILD ACROSS
THEN BUILD SLOWLY ACROSS THE SOUTHEAST BETWEEN AN UPPER LOW THAT
CLOSES OFF OVER NEW ENGLAND AND RIDGING OVER THE CENTRAL US. TEMPS
MAY SLOWLY MODERATE BUT WILL REMAIN AT OR JUST BELOW NORMAL.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 145 AM SATURDAY...
COMPLEX FORECAST FOR THIS TAF PERIOD...AND BEYOND THROUGH EARLY THIS
UPCOMING WEEK.
AN AXIS OF IFR-MVFR STRATUS HAS DEVELOPED AND SPREAD DIRECTLY ACROSS
THE CENTRAL CAROLINAS THIS MORNING...CENTERED FROM NEAR CAE TO RDU
TO TDF...OR JUST EAST OF THE TRIAD TERMINALS AND JUST WEST OF FAY.
THIS CLOUD BAND IS FORECAST TO HOLD RELATIVELY STATIONARY THROUGH
12Z...BEFORE SHIFTING EAST TOWARD RWI THROUGH 18Z. MEANWHILE...A PRE-
FRONTAL BAND OF RAIN AND OCCASIONAL IFR-MVFR CONDITIONS...AMIDST
OTHERWISE LOW VFR CEILINGS...WILL ARRIVE FROM THE WEST BETWEEN 10-
12Z AT WESTERN TERMINALS TO 14-17Z AT EASTERN ONES...BASICALLY ON
THE HEELS OF THE DEPARTING INITIAL BAND OF MVFR CEILINGS. THEN YET A
THIRD REGIME OF IFR-MVFR CONDITIONS AND NUMEROUS TO WIDESPREAD
SHOWERS (AND ISOLATED THUNDERSTORMS) WILL SWEEP EAST INTO OUR AREA
BETWEEN 17-19Z AT WESTERN TERMINALS TO BETWEEN 20-22Z AT EASTERN
ONES. THE PASSAGE OF A COLD FRONT AND FOLLOWING WNW BREEZE WILL HELP
SCOUR AND LIFT THE CLOUD LAYER...PARTICULARLY AT TRIAD TERMINALS
THIS EVENING...THOUGH SUB-VFR CONDITIONS AND AREAS OF LIGHT RAIN OR
DRIZZLE ARE APT TO LINGER THROUGHOUT THE NIGHT...ESPECIALLY AT
RDU/RWI/FAY.
OUTLOOK: IN THE WAKE OF THE AFOREMENTIONED COLD FRONT...BRISK NNE
WINDS...AND A THREAT OF MVFR CEILINGS AT EASTERN TERMINALS...ARE
EXPECTED ON SUNDAY. WHILE FORECAST CONFIDENCE IS BELOW AVERAGE...THE
DEVELOPMENT OF A COASTAL STORM NEAR THE SOUTH AND MIDDLE ATLANTIC
COAST MAY RESULT IN A REDEVELOPMENT/SOUTHWESTWARD EXPANSION OF MVFR
CEILINGS...AND POSSIBLY RAIN...LATE SUN NIGHT-MON NIGHT.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...MWS
SHORT TERM...WSS
LONG TERM...BLS
AVIATION...MWS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
330 AM EST SAT DEC 6 2014
.SYNOPSIS...A SHORTWAVE TROUGH INITIALLY OVER THE MID MS AND TN
VALLEYS WILL AMPLIFY ACROSS THE SOUTHERN APPALACHIANS AND CAROLINAS
THROUGH TONIGHT. AN ACCOMPANYING SURFACE LOW OVER THE LOWER OH AND
TN VALLEY WILL RE-DEVELOP OVER VA/NC TODAY...THEN BEGIN TO INTENSIFY
AS IT APPROACHES A COASTAL FRONT ALONG THE NC COAST THIS EVENING-
TONIGHT. MEANWHILE...ARCTIC HIGH PRESSURE WILL STRENGTHEN AS IT
MIGRATES FROM THE NORTHERN PLAINS TO NEW ENGLAND...THE SOUTHERN
PERIPHERY OF WHICH WILL RIDGE SOUTH INTO NC LATE TONIGHT THROUGH
SUNDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM SATURDAY...
A COASTAL FRONT ALONG THE SOUTHEAST AND MIDDLE ATLANTIC COASTS HAS
CAUSED A PIECE OF THE 1040 MB MODIFIED ARCTIC CENTERED NEAR
NEWFOUNDLAND TO BREAK OFF OVER THE CAROLINAS THIS MORNING...AND THIS
1027 MB HIGH WILL LIKELY ESTABLISH A SHORT-LIVED IN-SITU CAD EVENT
OVER AT LEAST THE WESTERN PIEDMONT TODAY. WHETHER OR NOT THE WEDGE
IS ESTABLISHED EAST ACROSS THE REMAINDER OF CENTRAL NC IS MORE IN
QUESTION...SINCE IT SEEMS THE UPSTREAM PRE-FRONTAL BAND OF RAIN NOW
CROSSING THE SOUTHERN-CENTRAL APPALACHIANS HAS BEEN FALLING MOSTLY
FROM MID LEVEL CEILINGS...AND AS SUCH...WOULD MAKE IT LESS LIKELY TO
FULLY SATURATE THE LOW LEVELS AND HELP ESTABLISH A WEDGE. IN
FACT...BOTH THE RAP AND HRRR SUGGEST THE INITIAL BAND OF IFR-MVFR
CEILINGS CENTERED FROM NEAR CAE TO RDU TO RIC THIS MORNING WILL
DRIFT EAST THROUGH MIDDAY...AND PROVIDE FOR A PERIOD OF MOSTLY MID-
HIGH LEVEL CLOUDS AND MODEST INSOLATION DURING THE MIDDAY-EARLY
AFTERNOON HOURS. THE MAIN SENSIBLE WEATHER IMPACT WITH THIS
UNCERTAINTY REGARDS TEMPERATURES...WHICH WOULD BE HELD IN THE MID-
UPPER 40S OVER THE NW PIEDMONT (SIMILAR TO FRI) TO GENERALLY MID 50S
ELSEWHERE. BASED ON UPSTREAM OBSERVATIONS OF RAIN FROM MOSTLY MID
CLOUDS...WILL TREND HIGH TEMPS TOWARD SOME MODEST INSOLATION...WITH
HIGHS RANGING FROM THE MIDDLE 50S TO NEAR 60 DEGREES...EXCEPT AROUND
50 DEGREES OR SO IN THE WESTERN PIEDMONT WHERE THE OPPORTUNITY FOR
INSOLATION WILL BE MORE LIMITED BETWEEN THE PRE-FRONTAL RAIN
BAND...AND A TRAILING SEPARATE AREA OF SHALLOW CONVECTIVE
PRECIPITATION FORECAST TO MOVE ACROSS THE AREA LATER THIS AFTERNOON.
THAT TRAILING PRECIPITATION...WILL BE FUELED BY SUBSTANTIAL COOLING
ALOFT ACCOMPANYING A PARENT SHORTWAVE TROUGH ALOFT...ATOP A WARM AND
MOIST...40 KT LLJ. THE ASSOCIATED STRONG DIFFERENTIAL THERMAL
ADVECTION WILL CAUSE H85-5 LAPSE RATES TO STEEPEN IN EXCESS OF 6.5
C/KM OVER CENTRAL NC...COINCIDENT WITH 50-80 METER MID LEVEL HEIGHT
FALLS ACCOMPANYING THE PARENT SHORTWAVE TROUGH ALOFT. FORECAST
GUIDANCE CONTINUES TO SUGGEST THAT A POCKET OF UP TO A FEW HUNDRED
J/KG OF MUCAPE WILL CONSEQUENTLY DEVELOP OVER OUR AREA THIS
AFTERNOON...WHICH WILL SUPPORT THE EASTWARD PROGRESSION AND/OR RE-
DEVELOPMENT OF NUMEROUS TO WIDESPREAD SHOWERS AND ISOLATED
THUNDERSTORMS ACROSS CENTRAL NC THIS AFTERNOON.
THOUGH SHOWERS AND ISOLATED STORMS WILL MOVE EAST WITH THE PASSAGE
OF A THE OCCLUDED/COLD FRONT THIS EVENING...THE DEEPENING OF A
SURFACE LOW AS IT ENCOUNTERS THE COASTAL FRONT WILL MAINTAIN A MOIST
NNE FLOW THAT WILL LIKELY RESULT IN CONSIDERABLE LOW OVERCAST AND
AREAS OF LIGHT RAIN OR DRIZZLE...WHICH WILL ONLY SLOWLY EDGE
EASTWARD THROUGH SUN MORNING...PARTICULARLY OVER THE EASTERN TWO
THIRDS OF THE CWFA. LOWS MOSTLY IN THE LOWER TO MIDDLE 40S.
&&
.SHORT TERM /SUNDAY AND SUNDAY NIGHT/...
AS OF 220 PM FRIDAY...
SUNDAY AND SUNDAY NIGHT: THE LATEST RUN OF THE ECMWF AGREES WELL
WITH THE GFS IN REGARD TO THE LOW AND ITS ASSOCIATED COLD FRONT
MOVING OFF THE CAROLINA COAST PRIOR TO 12Z SUNDAY. AS SUCH...HAVE A
DRY FORECAST FOR SUNDAY AND SUNDAY NIGHT. THE BIG QUESTION WILL BE
HOW QUICKLY THE SKIES CLEAR AND HOW THAT WILL AFFECT TEMPERATURES.
FOR NOW...EXPECT HIGHS IN THE UPPER 40S NW TO 723MID 50S SOUTH AND
EAST...ALTHOUGH IF SKIES CLEAR QUICKER/SLOWER THAT COULD CHANGE BY A
COUPLE/FEW DEGREES. LOWS GENERALLY IN LOW 30S NW TO UPPER 30S SE.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 220 PM FRIDAY...
MONDAY THROUGH FRIDAY: CONFIDENCE IS STILL NOT TERRIBLY HIGH FOR
NEXT WEEK...HOWEVER IT HAS INCREASED SOME OVERALL AS THE MODELS
APPEAR TO BE SLOWLY COMING INTO BETTER AGREEMENT. THE ECMWF SEEMS TO
BE TRENDING MORE TOWARD THE GFS WITH THE UPPER LEVEL LOW THAT MOVES
THROUGH THE GREAT LAKES AND NORTHEAST U.S. TOWARD THE END OF NEXT
WEEK. ALTHOUGH IT CONTINUES TO BE DEEPER WITH THE UPPER LEVEL TROUGH
AND STILL TRIES TO GENERATE A BIT OF PRECIPITATION OVER PORTIONS OF
THE CAROLINAS EARLY IN THE WEEK. THERE IS STILL SOME UNCERTAINTY
WITH RESPECT TO THAT LOW...AND GIVEN THE MODEL TREND...EXPECT IT TO
STAY MAINLY WELL NORTH OF THE REGION AND BE OF LITTLE CONSEQUENCE IN
THE PRECIPITATION DEPARTMENT FOR CENTRAL NC AT THIS TIME. WITH THAT
HYPOTHESIS IN MIND...EXPECT NEXT WEEK TO BE GENERALLY DRY...WITH
HIGH PRESSURE DOMINATING AT THE SURFACE. THE FIRST HIGH WILL RIDGE
IN FROM THE NORTHEAST AND RESULT IN A WEDGE OF A COLD AIR OVER THE
AREA. A REINFORCING SHOT OF COLD AIR WILL PUSH THROUGH THE AREA
TUESDAY NIGHT INTO WEDNESDAY...WITH ANOTHER AREA OF HIGH PRESSURE
SUBSEQUENTLY BUILDING IN THROUGH THE END OF THE WEEK. HIGHS ON
MONDAY WILL BE THE COOLEST OF THE PERIOD...MID 40S NW TO LOW 50S SE.
HIGHS WILL CONTINUE TO BE A LITTLE BIT OF A RO723LLER COASTER
THROUGH THE REST OF THE WEEK...WITH LOW TO MID 50S EXPECTED ON
TUESDAY AND FRIDAY...BUT UPPER 40S TO LOW 50S WEDNESDAY AND
THURSDAY. LOWS WILL GENERALLY DECREASE FROM THE LOW 30S NW TO UPPER
30S SE MONDAY NIGHT TO UPPER 20S ACROSS THE AREA BY WED AND THU
NIGHTS...MODERATING AGAIN INTO THE LOW 30S FRI NIGHT.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 145 AM SATURDAY...
COMPLEX FORECAST FOR THIS TAF PERIOD...AND BEYOND THROUGH EARLY THIS
UPCOMING WEEK.
AN AXIS OF IFR-MVFR STRATUS HAS DEVELOPED AND SPREAD DIRECTLY ACROSS
THE CENTRAL CAROLINAS THIS MORNING...CENTERED FROM NEAR CAE TO RDU
TO TDF...OR JUST EAST OF THE TRIAD TERMINALS AND JUST WEST OF FAY.
THIS CLOUD BAND IS FORECAST TO HOLD RELATIVELY STATIONARY THROUGH
12Z...BEFORE SHIFTING EAST TOWARD RWI THROUGH 18Z. MEANWHILE...A PRE-
FRONTAL BAND OF RAIN AND OCCASIONAL IFR-MVFR CONDITIONS...AMIDST
OTHERWISE LOW VFR CEILINGS...WILL ARRIVE FROM THE WEST BETWEEN 10-
12Z AT WESTERN TERMINALS TO 14-17Z AT EASTERN ONES...BASICALLY ON
THE HEELS OF THE DEPARTING INITIAL BAND OF MVFR CEILINGS. THEN YET A
THIRD REGIME OF IFR-MVFR CONDITIONS AND NUMEROUS TO WIDESPREAD
SHOWERS (AND ISOLATED THUNDERSTORMS) WILL SWEEP EAST INTO OUR AREA
BETWEEN 17-19Z AT WESTERN TERMINALS TO BETWEEN 20-22Z AT EASTERN
ONES. THE PASSAGE OF A COLD FRONT AND FOLLOWING WNW BREEZE WILL HELP
SCOUR AND LIFT THE CLOUD LAYER...PARTICULARLY AT TRIAD TERMINALS
THIS EVENING...THOUGH SUB-VFR CONDITIONS AND AREAS OF LIGHT RAIN OR
DRIZZLE ARE APT TO LINGER THROUGHOUT THE NIGHT...ESPECIALLY AT
RDU/RWI/FAY.
OUTLOOK: IN THE WAKE OF THE AFOREMENTIONED COLD FRONT...BRISK NNE
WINDS...AND A THREAT OF MVFR CEILINGS AT EASTERN TERMINALS...ARE
EXPECTED ON SUNDAY. WHILE FORECAST CONFIDENCE IS BELOW AVERAGE...THE
DEVELOPMENT OF A COASTAL STORM NEAR THE SOUTH AND MIDDLE ATLANTIC
COAST MAY RESULT IN A REDEVELOPMENT/SOUTHWESTWARD EXPANSION OF MVFR
CEILINGS...AND POSSIBLY RAIN...LATE SUN NIGHT-MON NIGHT.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...MWS
SHORT TERM...WSS
LONG TERM...KC
AVIATION...MWS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
145 AM EST SAT DEC 6 2014
.SYNOPSIS...A COLD FRONT WILL APPROACH FROM THE WEST TODAY...THEN
CROSS OUR REGION THIS EVENING. HIGH PRESSURE WILL FOLLOW FOR SUNDAY.
&&
.NEAR TERM /TONIGHT/...
AS OF 1010 PM FRIDAY...
TWO MAIN FORECAST PROBLEMS FOR THIS EVENING...THE FIRST...WILL THERE
BE FOG ACROSS THE SOUTHERN COUNTIES...AND SECOND...THE ARRIVAL TIME
OF THE PRECIPITATION ON SATURDAY. ADDRESSING THE FOG...MUCH OF
CENTRAL NC REMAINS ENSHROUDED IN CLOUD COVER WITH SOME CLEARING
ACROSS THE SOUTHWEST. VISIBILITIES FOR THE MOST PART HAVE REMAINED
ABOVE TEN MILES AS DEWPOINT DEPRESSIONS HAVE ALSO REMAINED PLUS OR
MINUS FIVE DEGREES. AS THE AREA OF CLEARING OVER THE SOUTHWEST MOVES
EASTWARD...THERE COULD BE A FEW HOURS BEFORE SUNRISE WHEN THE
TEMPERATURE DROPS TO THE DEWPOINT AND SOME PATCHY DENSE FOG WILL BE
POSSIBLE. FOR THE MOST PART HOWEVER...LOW STRATUS WILL BE THE MORE
LIKELY SCENARIO WITH SEVERAL SITES IN THE SANDHILLS ALREADY SHOWING
MVFR CEILINGS.
THE MAIN SYSTEM THAT IS EXPECTED TO GENERATE PRECIPITATION OVER THE
AREA ON SATURDAY REMAINS OVER THE TENNESSEE VALLEY AND SHORT TERM
MODELS ARE PROGGING THE ARRIVAL OF THE PRECIP TO BE A LITTLE BIT
LATER THAN PREVIOUSLY ANTICIPATED. HAVE CUT BACK ON POPS SATURDAY
MORNING AND BLEND INTO HIGHER POPS STILL EXPECTED FOR SATURDAY
AFTERNOON/EVENING. THE LATEST RAP MODEL ACTUALLY SHOWS PRECIP IN OUR
CWA BEGINNING FIRST IN THE EAST IN ASSOCIATION WITH A SMALLER WAVE
MOVING IN OFF OF THE SW ATLANTIC AFTER 9Z AND THEN PRECIPITATION
ASSOCIATED WITH THE WESTERN SYSTEM APPROACHING THE NW PIEDMONT AFTER
12Z SATURDAY.
LOWS TONIGHT WILL RANGE FROM THE LOW TO MIDDLE 40S.
&&
.SHORT TERM /SATURDAY AND SATURDAY NIGHT/...
AS OF 310 PM FRIDAY...
SATURDAY... S/W AND ASSOCIATED SURFACE FRONT WILL BE TO OUR WEST AT
18Z...CROSSING OUR REGION SATURDAY EVENING. LOW-MID LEVEL SOUTH-
SOUTHWEST FLOW WILL ADVECT ABUNDANT MOISTURE INTO OUR REGION.
MEANWHILE SUFFICIENT LIFT WILL BE PROVIDED BY: A.) DIVERGENCE ALOFT
DUE TO THE CAROLINAS BEING IN THE FAVORABLE POSITION OF TWO JETS
(ONE EXITING NEW ENGLAND WHILE THE OTHER DIVING SEWD ACROSS THE TN
VALLEY); B.) 40-60M/12 HOUR MID LEVEL HEIGHT FALLS; C.) AND LATER IN
THE DAY, CONVERGENCE ALONG THE SFC-850MB COLD FRONT. THIS FAVORABLE
ATMOSPHERE SHOULD CAUSE NUMEROUS SHOWERS TO OVERSPREAD THE PIEDMONT
AND THE NORTHERN COASTAL PLAIN DURING THE MORNING HOURS...AND INTO
THE SANDHILLS AND THE REMAINDER OF THE COASTAL PLAIN IN THE
AFTERNOON.
POTENTIAL EXISTS FOR A FEW THUNDERSTORMS TO OCCUR SATURDAY AFTERNOON-
EARLY EVENING AS MID LEVEL LAPSE RATES REACH AS HIGH AS 6.5-7 DEG
C/KM AND BULK SHEAR ACHIEVES FAVORABLE VALUES 30-35KTS. LOW LEVEL
INSTABILITY LACKING AS SBCAPE IS AOB 200 J/KG WHILE MUCAPE NO HIGHER
THAN 200-250 J/KG LATE SATURDAY-SATURDAY EVENING. THUS...EXPECT
CONVECTION TO BE ELEVATED WITH LITTLE IF ANY CHANCE OF STORMS
BECOMING STRONG/SEVERE.
HIGH TEMPS SATURDAY STILL A CHALLENGE...DEPENDENT UPON EXTENT OF
RAIN SHOWERS. STILL FAVOR MAX TEMPS SLIGHTLY COOLER THAN GUIDANCE
ACROSS THE PIEDMONT AS A SHORT-LIVED IN-SITU OR HYBRID CAD MAY SET
UP EARLY SATURDAY. CONVERSELY...IF SHOWERS HOLD OFF LONG
ENOUGH...TEMPS IN THE SANDHILLS AND SOUTHERN COASTAL PLAIN MAY WARM
INTO THE MID-UPPER 60S.
SATURDAY NIGHT... SURFACE COLD FRONT PROGRESSES EAST ACROSS CENTRAL
NC IN THE EVENING...EXITING OUR COASTAL PLAIN COUNTIES AROUND OR
SHORTLY AFTER MIDNIGHT. THE 850-700MB TROUGHS FOLLOW SHORTLY
AFTERWARDS. LOW-MID LEVEL N-NW FLOW IN THE WAKE OF THE TROUGH
PASSAGE WILL AID TO DIMINISH SHOWER COVERAGE IN THE WEST SATURDAY
EVENING...AND OVERNIGHT IN THE EAST. PARTIAL CLEARING SHOULD
INITIATE IN THE NORTH-NW AFTER MIDNIGHT. SURFACE FRONTAL PASSAGE
WILL BE NOTED BY WINDS VEERING TO THE N-NW AND INITIALLY GUSTING
AROUND 20KTS. MIN TEMPS LOW-MID 40S NORTH TO UPPER 40S SE.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
AS OF 220 PM FRIDAY...
SUNDAY AND SUNDAY NIGHT: THE LATEST RUN OF THE ECMWF AGREES WELL
WITH THE GFS IN REGARD TO THE LOW AND ITS ASSOCIATED COLD FRONT
MOVING OFF THE CAROLINA COAST PRIOR TO 12Z SUNDAY. AS SUCH...HAVE A
DRY FORECAST FOR SUNDAY AND SUNDAY NIGHT. THE BIG QUESTION WILL BE
HOW QUICKLY THE SKIES CLEAR AND HOW THAT WILL AFFECT TEMPERATURES.
FOR NOW...EXPECT HIGHS IN THE UPPER 40S NW TO 723MID 50S SOUTH AND
EAST...ALTHOUGH IF SKIES CLEAR QUICKER/SLOWER THAT COULD CHANGE BY A
COUPLE/FEW DEGREES. LOWS GENERALLY IN LOW 30S NW TO UPPER 30S SE.
MONDAY THROUGH FRIDAY: CONFIDENCE IS STILL NOT TERRIBLY HIGH FOR
NEXT WEEK...HOWEVER IT HAS INCREASED SOME OVERALL AS THE MODELS
APPEAR TO BE SLOWLY COMING INTO BETTER AGREEMENT. THE ECMWF SEEMS TO
BE TRENDING MORE TOWARD THE GFS WITH THE UPPER LEVEL LOW THAT MOVES
THROUGH THE GREAT LAKES AND NORTHEAST U.S. TOWARD THE END OF NEXT
WEEK. ALTHOUGH IT CONTINUES TO BE DEEPER WITH THE UPPER LEVEL TROUGH
AND STILL TRIES TO GENERATE A BIT OF PRECIPITATION OVER PORTIONS OF
THE CAROLINAS EARLY IN THE WEEK. THERE IS STILL SOME UNCERTAINTY
WITH RESPECT TO THAT LOW...AND GIVEN THE MODEL TREND...EXPECT IT TO
STAY MAINLY WELL NORTH OF THE REGION AND BE OF LITTLE CONSEQUENCE IN
THE PRECIPITATION DEPARTMENT FOR CENTRAL NC AT THIS TIME. WITH THAT
HYPOTHESIS IN MIND...EXPECT NEXT WEEK TO BE GENERALLY DRY...WITH
HIGH PRESSURE DOMINATING AT THE SURFACE. THE FIRST HIGH WILL RIDGE
IN FROM THE NORTHEAST AND RESULT IN A WEDGE OF A COLD AIR OVER THE
AREA. A REINFORCING SHOT OF COLD AIR WILL PUSH THROUGH THE AREA
TUESDAY NIGHT INTO WEDNESDAY...WITH ANOTHER AREA OF HIGH PRESSURE
SUBSEQUENTLY BUILDING IN THROUGH THE END OF THE WEEK. HIGHS ON
MONDAY WILL BE THE COOLEST OF THE PERIOD...MID 40S NW TO LOW 50S SE.
HIGHS WILL CONTINUE TO BE A LITTLE BIT OF A RO723LLER COASTER
THROUGH THE REST OF THE WEEK...WITH LOW TO MID 50S EXPECTED ON
TUESDAY AND FRIDAY...BUT UPPER 40S TO LOW 50S WEDNESDAY AND
THURSDAY. LOWS WILL GENERALLY DECREASE FROM THE LOW 30S NW TO UPPER
30S SE MONDAY NIGHT TO UPPER 20S ACROSS THE AREA BY WED AND THU
NIGHTS...MODERATING AGAIN INTO THE LOW 30S FRI NIGHT.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 145 AM SATURDAY...
COMPLEX FORECAST FOR THIS TAF PERIOD...AND BEYOND THROUGH EARLY THIS
UPCOMING WEEK.
AN AXIS OF IFR-MVFR STRATUS HAS DEVELOPED AND SPREAD DIRECTLY ACROSS
THE CENTRAL CAROLINAS THIS MORNING...CENTERED FROM NEAR CAE TO RDU
TO TDF...OR JUST EAST OF THE TRIAD TERMINALS AND JUST WEST OF FAY.
THIS CLOUD BAND IS FORECAST TO HOLD RELATIVELY STATIONARY THROUGH
12Z...BEFORE SHIFTING EAST TOWARD RWI THROUGH 18Z. MEANWHILE...A PRE-
FRONTAL BAND OF RAIN AND OCCASIONAL IFR-MVFR CONDITIONS...AMIDST
OTHERWISE LOW VFR CEILINGS...WILL ARRIVE FROM THE WEST BETWEEN 10-
12Z AT WESTERN TERMINALS TO 14-17Z AT EASTERN ONES...BASICALLY ON
THE HEELS OF THE DEPARTING INITIAL BAND OF MVFR CEILINGS. THEN YET A
THIRD REGIME OF IFR-MVFR CONDITIONS AND NUMEROUS TO WIDESPREAD
SHOWERS (AND ISOLATED THUNDERSTORMS) WILL SWEEP EAST INTO OUR AREA
BETWEEN 17-19Z AT WESTERN TERMINALS TO BETWEEN 20-22Z AT EASTERN
ONES. THE PASSAGE OF A COLD FRONT AND FOLLOWING WNW BREEZE WILL HELP
SCOUR AND LIFT THE CLOUD LAYER...PARTICULARLY AT TRIAD TERMINALS
THIS EVENING...THOUGH SUB-VFR CONDITIONS AND AREAS OF LIGHT RAIN OR
DRIZZLE ARE APT TO LINGER THROUGHOUT THE NIGHT...ESPECIALLY AT
RDU/RWI/FAY.
OUTLOOK: IN THE WAKE OF THE AFOREMENTIONED COLD FRONT...BRISK NNE
WINDS...AND A THREAT OF MVFR CEILINGS AT EASTERN TERMINALS...ARE
EXPECTED ON SUNDAY. WHILE FORECAST CONFIDENCE IS BELOW AVERAGE...THE
DEVELOPMENT OF A COASTAL STORM NEAR THE SOUTH AND MIDDLE ATLANTIC
COAST MAY RESULT IN A REDEVELOPMENT/SOUTHWESTWARD EXPANSION OF MVFR
CEILINGS...AND POSSIBLY RAIN...LATE SUN NIGHT-MON NIGHT.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...ELLIS
SHORT TERM...WSS
LONG TERM...KC
AVIATION...MWS
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
124 AM EST SAT DEC 6 2014
.SYNOPSIS...
HIGH PRESSURE WILL MOVE OFFSHORE TONIGHT. A COASTAL TROUGH WILL
LIFT NORTH AS A WARM FRONT ON SATURDAY...AHEAD OF A COLD FRONT
WHICH WILL MOVE ACROSS THE AREA SATURDAY NIGHT. THIS COLD FRONT
WILL BRING A PERIOD OF SHOWERS WITH AN ISOLATED THUNDERSTORM
POSSIBLE. A STRONG WEDGE OF HIGH PRESSURE WILL BUILD SOUTH SUNDAY
AND MONDAY...BRINGING GUSTY NORTH WINDS AND MUCH COOLER
TEMPERATURES. CANADIAN HIGH PRESSURE NEXT WEEK WILL MAINTAIN
SEASONABLY COOL TEMPERATURES AND DRY CONDITIONS.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 124 AM SATURDAY...A COASTAL TROUGH DEVELOPING ACROSS THE
WATERS IS EXPECTED TO DRIFT TO THE COAST OVERNIGHT. CONVERGENT
FLOW IN ASSOCIATION WITH THE TROUGH SHOULD HELP TO BRING SOME OF
THE OFFSHORE SHOWERS ONTO THE COAST LATE TONIGHT. THE HIGH
RESOLUTION HRRR IS MOST BULLISH WITH THIS SCENARIO...PRIMARILY FOR
THE CAPE FEAR AREA LATE TONIGHT. OTHERWISE AS CHILLY HIGH PRESSURE
DRIFTS OFFSHORE AND A TROUGH APPROACHES FROM THE W...A DEEP S TO
SW FLOW WILL ENVELOP THE EASTERN CAROLINAS. THE COLUMN WILL
CONTINUE TO SLOWLY MOISTEN...PRECIPITABLE WATER VALUES WILL REACH
NEAR 1.25 INCHES BY SUNRISE. SHOWERS ASSOCIATED WITH THE
AFOREMENTIONED TROUGH WILL REMAIN W OF THE FORECAST AREA INTO
EARLY SAT MORNING. A WARM AIR ADVECTION PATTERN AND INCREASING
MOISTURE CONTENT WILL BRING A GOOD DEAL OF CLOUDINESS THROUGH THE
NIGHT. THE CLOUDS SHOULD HELP TO FLATTEN THE TEMP CURVE WITH LOWS
MAINLY IN THE MID AND UPPER 40S INLAND AND LOWER 50S AT THE
COAST...SO LITTLE TEMP MOVEMENT THROUGH THE NIGHT. ALTHOUGH MODELS
ARE INDICATING A PRONOUNCED NEAR SURFACE INVERSION DEVELOPING...THEY
ARE RELUCTANT TO SATURATE THE LEVEL CLOSEST TO THE GROUND. ALSO...
USING A UPS FOG METHODOLOGY GRIDDED SMART TOOL...FOG IS EXPECTED TO
DEVELOP W OF THE FORECAST AREA AND ADVECT NORTHWARD WITH TIME.
THUS...STILL LOOKS AS THOUGH SIGNIFICANT FOG WILL HAVE A DIFFICULT
TIME DEVELOPING AND WILL FAVOR LOW STRATUS OVER FOG AT THIS
TIME...BUT CONTINUE TO MONITOR NEAR TERM TRENDS. THIS LOW STRATUS
MAY PRODUCE SOME SPOTTY DRIZZLE FROM TIME TO TIME AND HAVE ADDED
PATCHY DRIZZLE TO THE FORECAST TOWARD MORNING.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 PM FRIDAY...COASTAL TROUGH LIFTING NORTH AS A WARM
FRONT SATURDAY MORNING WILL CREATE A WARM DAY...ESPECIALLY ALONG
THE COAST...BUT RAIN CHANCES WILL INCREASE RAPIDLY LATE IN THE
DAY. AS THE COASTAL TROUGH LIFTS NORTH EARLY...WAA WILL FOLLOW
THROUGH THE AFTN...WITH 850MB TEMPS CLIMBING TO AROUND 10C BY
SATURDAY AFTN. AS THIS OCCURS HOWEVER...CLOUD COVER WILL BE ON THE
INCREASE THANKS TO MOIST ADVECTION AND PVA AHEAD OF A SHORTWAVE
WHICH WILL MOVE JUST NORTH OF THE AREA SATURDAY NIGHT. BENEATH
THIS SHORTWAVE...A SURFACE LOW WILL PUSH EAST NEAR THE NC/VA
BORDER...DRAGGING A COLD FRONT ACROSS THE CWA SATURDAY NIGHT. AS
PWATS RISE TO ABOUT 1.25 INCHES AND MID-LEVEL LAPSE RATES CLIMB
TOWARDS 7C/KM...SCATTERED SHOWERS WITH ISOLATED TSTMS ARE
EXPECTED. INSTABILITY REMAINS MINIMAL...BUT CANNOT RULE OUT A FEW
LIGHTNING STRIKES...AND THIS IS ECHOED BY THE GENERAL RISK
ENCOMPASSING THE ILM CWA IN THE SWODY2. TOTAL QPF WILL NOT BE VERY
HIGH...BUT BRIEF PERIODS OF HEAVY RAIN IS POSSIBLE WITHIN A FEW
HOURS EITHER SIDE OF SATURDAY EVENING. COOL ADVECTION BEGINS IN
EARNEST BEHIND THE COLD FRONT LATE SATURDAY NIGHT...SO TEMPS WHICH
WILL RISE TOWARDS 70 ALONG THE COAST SATURDAY AFTN...MID 60S WELL
INLAND...WILL DROP RAPIDLY INTO THE LOW 40S WELL NW...TO AROUND 50
AT THE COAST...BY SUNDAY MORNING.
A QUIETER BUT MUCH COOLER DAY ON SUNDAY AS A STRONG WEDGE OF HIGH
PRESSURE DEVELOPS BEHIND THE COLD FRONT FROM SATURDAY NIGHT. WITH
LOW-LEVEL MOISTURE PROGGED TO REMAIN HIGH BENEATH THE WEDGE...PARTLY
TO MOSTLY CLOUDY CONDITIONS WILL PERSIST MUCH OF SUNDAY. THIS
COMBINED WITH COOL ADVECTION WILL LIMIT WARMING...AND HIGHS MAY BE
REACHED VERY EARLY IN THE DAY...WITH LITTLE DIURNAL RANGE. EXPECT
HIGHS ONLY IN THE LOW 50S IN THE FAR NORTH...TO MID 50S IN THE
SOUTH. SOME CLEARING WILL OCCUR VERY LATE...AND CONTINUED CAA WILL
HELP MINS FALL INTO THE UPPER 30S SUNDAY NIGHT.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 300 PM FRIDAY...THE MID LEVEL PATTERN WILL BE QUITE
PROGRESSIVE THROUGH THE PERIOD WITH THE AREA REMAINING VOID OF ANY
SIGNIFICANT PRECIPITATION. INITIALLY A LINGERING LOW PRESSURE
SYSTEM OFF THE SOUTHEAST COAST MAY PROVIDE A FEW SHOWERS...MORESO
ALONG THE COAST MONDAY BEFORE A COLD FRONT...ASSOCIATED WITH
FAIRLY STRONG SHORTWAVE MOVING THROUGH THE MIDWEST SWEEPS THE AREA
CLEAN. BEYOND THIS A WEAKENING CYCLONIC FLOW ALOFT WILL PREVAIL
ACROSS THE AREA. AT THE SURFACE...HIGH PRESSURE WILL BUILD DOWN
FROM THE UPPER MIDWEST TO ESSENTIALLY OVER THE AREA BY FRIDAY THUS
A DRY FORECAST. TEMPERATURES TRENDS LOOK A LITTLE BELOW
CLIMATOLOGY WITH HIGHS MOSTLY IN THE 50S AND LOWS IN THE LOWER TO
MIDDLE 30S
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AS OF 00Z...RATHER LOW CONFIDENCE ON THE BACK END OF THE FORECAST
PERIOD WITH RESPECT TO CEILINGS AND THE TIMING OF PRECIP. LOOKS LIKE
THERE COULD BE TWO BATCHES OF RAIN/SHOWERS: THE FIRST AROUND SUNRISE
WITH A COASTAL TROUGH...THEN ANOTHER ROUND IN THE LATE AFTERNOON
AHEAD OF A COLD FRONT. MODELS ARE IN REASONABLE AGREEMENT
INTRODUCING IFR STRATUS/FOG AROUND DAYBREAK IF NOT BEFORE...AND THIS
MAKES SENSE GIVEN THE WEAK WARM AIR ADVECTION. THE HRRR MODEL THINKS
THAT ILM STANDS THE BEST CHANCE FOR MORNING PRECIP...BUT THE MYRTLES
COULD ALSO GET INTO THE ACT. THINK THE MORNING PRECIP WILL GIVE WAY
TO MVFR CEILINGS AND SOUTHWESTERLY FLOW AHEAD OF A COLD FRONT WHICH
WILL ARRIVE AT THE END OF THE FORECAST PERIOD.
EXTENDED OUTLOOK...PERIODS OF MVFR/IFR CIGS ARE LIKELY THROUGH THE
WEEKEND AND INTO EARLY NEXT WEEK. GUSTY NORTH WINDS SUN/MON BEHIND
THE COLD FRONT. BECOMING VFR DURING TUE. VFR WED.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 125 PM SATURDAY...A COASTAL TROUGH WILL BE IN CLOSE PROXIMITY
THROUGH TONIGHT AND LIKELY JUST ABOUT ON THE IMMEDIATE COAST AROUND
DAYBREAK SAT. NE WINDS ARE EXPECTED TO SHIFT TO THE E OR ESE
OVERNIGHT WITH ITS PASSAGE. WIND SPEEDS WILL BE UP TO 10 TO 15 KT
LATE THIS EVE...DECREASING TO 10 KT OR LESS OVERNIGHT. SEAS WILL BE
3 TO 4 FT WITH A 8 TO 10 SECOND EASTERLY SWELL PRESENT.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 PM FRIDAY...QUIET MARINE CONDITIONS TO START THE
PERIOD...BUT RAPID DETERIORATION IS EXPECTED ON SUNDAY. WEAK
COASTAL TROUGH WILL LIFT NORTH ON SATURDAY...WITH WINDS TURNING
FROM SE TO SW THROUGH THE AFTN...BUT AT LIGHT SPEEDS. LOW PRESSURE
MOVING NORTH OF THE AREA WILL DRAG A COLD FRONT ACROSS THE WATERS
SATURDAY NIGHT...AND WINDS WILL TURN ABRUPTLY TO THE NORTH AT
15-20 KTS BY SUNDAY MORNING. SEAS ON SATURDAY WILL BE GENERALLY
2-4 FT REGARDLESS OF WIND DIRECTION...BUT WILL BEGIN TO RISE LATE
BEHIND THE COLD FRONT.
GALE WATCH HAS BEEN HOISTED FOR THE NC WATERS BEGINNING SUNDAY
MORNING...AND THERE IS PRETTY HIGH CONFIDENCE IN A GALE OCCURRING
SUNDAY AS A STRONG WEDGE OF HIGH PRESSURE BUILDS DOWN THE COAST.
THIS WILL CAUSE A TIGHT GRADIENT OVER THE WATERS...AND WIND WILL
BECOME NE AT 20-30 KTS ON SUNDAY...WITH FREQUENT GUSTS TO 35 KTS OR
MORE EXPECTED ACROSS THE NC WATERS. THERE IS LOWER CONFIDENCE IN
GALE-FORCE WINDS ACROSS SC WATERS...BUT AT LEAST A STRONG SMALL
CRAFT ADVISORY IS EXPECTED. THESE STRONG WINDS WILL ALSO PUSH SEAS
UP TO TO 5-9 FT ON SUNDAY...WITH THE EXCEPTION BEING THE WAVE
SHADOWED REGION SW OF BRUNSWICK COUNTY.
LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 300 PM FRIDAY...NEXT WEEK WILL NOT BE THE BEST OF TIMES FOR
THE MARINE COMMUNITY AS BLUSTERY CONDITIONS AND ELEVATED SEAS WILL
CONTINUE. FOR MONDAY A POTENT NORTHERLY FLOW WILL CONTINUE AS LOW
PRESSURE MOVES WELL OFF TO THE NORTHEAST AND MASSIVE HIGH PRESSURE
BUILDS IN FROM THE NORTHWEST. EXPECT WINDS OF 20-25 KNOTS...POSSIBLY
HIGHER WITH CERTAIN SMALL CRAFT CONDITIONS AND POSSIBLY GALES. THE
WINDS DO DIMINISH THROUGHOUT THE DAY TO SETTLE AT 10-15 KNOTS BY
TUESDAY MORNING. HERE THE WINDS WILL REMAIN THROUGH WEDNESDAY. SEAS
WILL BE HIGHEST MONDAY WITH 3-6 FEET DROPPING TO 2-5 FEET TUESDAY
AND WEDNESDAY.
&&
.TIDES/COASTAL FLOODING...
AS OF 700 PM WEDNESDAY...THE FULL MOON IS ON SATURDAY. WE EXPECT
ELEVATED WATER LEVELS DURING THE TIME OF HIGH TIDE THROUGH THE
WEEKEND. THE MORNING HIGH TIDE WILL BE HIGHEST AND THIS IS WHEN WE
EXPECT THE TIDE TO COME UP WELL ONTO THE BEACH. STRONG NNE WINDS
SUNDAY AND SUNDAY NIGHT WILL HELP TO ENHANCE THE ASTRONOMICAL
EFFECTS. THE LOWER CAPE FEAR RIVER WILL ALSO EXPERIENCE HIGHER THAN
PREDICTED WATER LEVELS AND MAY REACH COASTAL FLOOD ADVISORY CRITERIA
DURING THE MORNING HIGH TIDE THROUGH THE WEEKEND.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...GALE WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY NIGHT
FOR AMZ250-252.
&&
$$
NEAR TERM...RJD/8
SHORT TERM...JDW
LONG TERM...SHK
AVIATION...DL
TIDES/COASTAL FLOODING...RJD
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1001 PM CST SUN DEC 7 2014
.UPDATE...
ISSUED AT 956 PM CST SUN DEC 7 2014
WILL CONTINUE TO MONITOR AVAILABLE GUIDANCE FOR PCPN PHASE
POTENTIAL REMAINDER OF THE OVERNIGHT. LATEST RUC SOUNDINGS
BECOMING MORE FAVORABLE FOR SNOW VS ZR AND METARS ACROSS THE NORTH
HAVE TRANSITIONED OVER TO -SN. SECONDARY NARROW DEF ZONE BAND
MOVING INTO THE WESTERN FA PRIMARILY SNOW ALTHOUGH COULD SEE A
BRIEF MIX. THIS FEATURE MOVING PRETTY QUICK SO NOT EVEN SURE AT
THIS POINT IF WE WILL SEE MEASURABLE PCPN WITH THIS UNLESS IT
EXPANDS.
UPDATE ISSUED AT 639 PM CST SUN DEC 7 2014
MAIN CONCERN WILL BE WHETHER ADDITIONAL HEADLINES WILL BE NEEDED
UNTIL COLUMN COOLS SUFFICIENTLY FOR ONLY SNOW. CURRENTLY A SMALL
AREA OF ENHANCED REFLECTIVITIES ALONG INTERNATIONAL BORDER AREA
FROM THE NORTHERN VALLEY INTO FAR NORTHERN MN. TEMPERATURES
CURRENTLY A FEW DEGREES ABOVE FREEZING HOWEVER AS TEMPERATURES
COOL WITH COLD ADVECTION NOSING IN ROADS COULD BECOME GLAZED. WILL
MONITOR PHASE AND TEMPERATURES AND IF NEEDED WILL ISSUE PROPER
HEADLINES. DID INCREASE POPS THIS AREA OTHERWISE NO REAL BIG
CHANGES AT THIS POINT.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 301 PM CST SUN DEC 7 2014
MIXED PRECIP WILL CONTINUE TO BE THE MAIN ISSUE THROUGH TONIGHT.
THE MAIN SHORTWAVE TROUGH CONTINUES TO MOVE THROUGH WESTERN ND SO
THE CWA WILL CONTINUE TO SEE SOME BROAD LIFT OVER THE REGION
THROUGH TONIGHT. THE WARM AIR ADVECTION FREEZING RAIN OVER OUR
EASTERN COUNTIES EARLIER TODAY HAS FINALLY MOVED OFF TO THE EAST
AND WILL LET THE ADVISORY GO BEFORE IT EXPIRES THIS AFTERNOON.
THERE HAS BEEN SOME WEAK PRECIP DEVELOPMENT OVER THE NORTHWESTERN
CWA AS THE CENTER OF THE SFC LOW BEGINS TO MOVE INTO THE AREA.
MODELS ALL BREAK OUT PERIODIC PRECIP OVER THE CWA AS THE LOW MOVES
ACROSS THE REGION THIS EVENING. THERE ARE SOME DIFFERENCES IN
EXACTLY WHERE THE PRECIP BREAKS OUT AND TIMING...SO WILL KEEP
MAINLY CHANCE POPS WITH SOME HIGHER LATER TONIGHT OVER
NORTHEASTERN COUNTIES AS THERE SEEMS TO BE SOME CONSOLIDATION OF
WRAP AROUND.
AS FAR AS TYPE...TEMPS IN THE NORTHWEST ARE JUST BELOW OR ABOVE
THE FREEZING MARK. SOME MIXED PRECIP WAS REPORTED IN LANGDON BUT
OTHER AREAS HAVE SEEN ONLY RAIN. THE POWT TOOL GIVES RAIN OVER
MUCH OF THE LOWER DEVILS LAKE BASIN WITH SOME IP AND FZRA MIXING
IN CLOSER TO THE CANADIAN BORDER. THIS SEEMS REASONABLE AT THIS
POINT. THE MIXED BAG OF PRECIP WILL SPREAD SOUTH AND EAST
THROUGHOUT THE EVENING...BUT WITH ONLY SOME CHANCE OF SCATTERED
ACTIVITY AND WHAT DOES OCCUR VERY LIGHT...WILL KEEP ANY HEADLINES
OUT FOR NOW. THE WARM LAYER ALOFT BEGINS TO BE ERODED AFTER
MIDNIGHT...AND PRECIP SHOULD SWITCH OVER TO ALL SNOW BY MORNING.
SOME LIGHT SNOW SHOWERS WILL LINGER OVER THE NORTHEASTERN CWA
THROUGHOUT THE DAY ON MONDAY...BUT ANY ACCUMULATIONS WILL BE AROUND
AN INCH OR LESS.
AS FOR TEMPERATURES...WITH A WARM START THIS EVENING AND THE TRUE
COLD AIR SURGE NOT REALLY COMING DOWN UNTIL WELL AFTER
MIDNIGHT...LOWS WILL REMAIN IN THE TEENS TO 20S. COLD AIR
ADVECTION WILL CONTINUE INTO MONDAY AS THE SFC HIGH SETTLES OVER
THE NORTHERN PLAINS. AFTERNOON TEMPS WILL ONLY TOP OUT IN THE 20S.
LOWS MONDAY NIGHT WILL DROP INTO THE SINGLE DIGITS AS WE BEGIN TO
SEE SOME CLEARING ON THE BACK SIDE OF THE SFC HIGH.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 301 PM CST SUN DEC 7 2014
TUESDAY AND WEDNESDAY...THE 500MB HEIGHTS RISE AND CONDITIONS WILL
BE FAIRLY QUIET ALTHOUGH THERE WILL BE A WEAK SHORTWAVE EMBEDDED
UNDER THE UPPER RIDGE OVER THE CENTRAL CONUS. THE NAM TRIES TO
BRING IN SOME LOW LEVEL MOISTURE AND LIGHT PRECIP INTO THE CWA ON
WEDNESDAY AS WINDS SHIFT TO THE SOUTH...BUT IT SEEMS TO BE AN
OUTLIER SO WILL JUST KEEP AN EYE ON IT FOR NOW. TEMPS ON TUESDAY
WILL REMAIN IN THE 20S BUT THERE SHOULD BE SOME GOOD WARMING ON
WEDNESDAY AS 850MB TEMPS NEARING 5 TO 8 C ARRIVE. HIGHS SHOULD BE
BACK UP INTO THE 30S IN MANY AREAS.
WEDNESDAY NIGHT-SUNDAY...MUCH OF THIS TIME PERIOD WILL BE MILD AND
DRY AS UPPER LEVEL RIDGING BUILDS ACROSS THE PLAINS. HIGH TEMPS
THROUGH SATURDAY SHOULD AT LEAST REACH THE 30S...AND POSSIBLY
WARMER. GLOBAL MODELS DEPICT THE RIDGE AXIS TO SHIFT EAST BY LATE
NEXT WEEKEND AS UPSTREAM ENERGY APPROACHES. HOWEVER...FORECAST
DETAILS LACK CLARITY BY THIS TIME...WITH MODELS DIFFERING ON THE
MOVEMENT OF THE CLOSED EASTERN CONUS UPPER LOW AND THE EVOLUTION OF
THE VARIOUS SHORTWAVES APPROACHING FROM THE WEST.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 639 PM CST SUN DEC 7 2014
CIGS VARY FROM IFR ACROSS THE FAR EAST WITH ZONE OF VFR CIGS
ACROSS THE CENTRAL FA AND MVFR CIGS MOVING INTO THE FAR WEST. MADE
BEST ATTEMPT TO TIME CHANGING CIGS FROM W-E THIS EVENING AS WELL
DEFINED MID LEVEL CIRCULATION CROSSES THE FA. BEST POTENTIAL FOR
MIXED PCPN WILL BE ALONG INTERNATIONAL BORDER AREA IN NW MN AND A
NARROW BAND OF SNOW MOVING EAST FROM N CENTRAL ND.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...VOELKER
SHORT TERM...JR
LONG TERM...JR/MAKOWSKI
AVIATION...VOELKER
AREA FORECAST DISCUSSION
NWS BISMARCK ND
333 PM CST SAT DEC 6 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 333 PM CST SAT DEC 6 2014
THE MAIN FORECAST ISSUE IN THE SHORT TERM PERIOD WILL BE POSSIBLE
FREEZING PRECIPITATION TONIGHT AND SUNDAY.
CURRENTLY A SHORTWAVE TROUGH IS LOCATED OVER EASTERN WASHINGTON. THE
WAVE WILL TRACK ALONG THE INTERNATIONAL BORDER OVERNIGHT AND DEVELOP
A SURFACE LOW IN THE LEE OF THE ROCKIES. THE SURFACE/UPPER LEVEL LOW
IS PROGGED TO BE OVER NORTHEAST MT/SOUTH CENTRAL SK BY 12 UTC
SUNDAY. WARM ADVECTION AHEAD OF THE LOW WILL RESULT IN WARM
TEMPERATURES ALOFT ENCOMPASSING ALL OF WESTERN AND CENTRAL NORTH
DAKOTA TONIGHT. THUS THE POTENTIAL FOR FREEZING PRECIPITATION
THROUGH SUNDAY AFTERNOON.
THE LATEST 20 UTC RAP DEPICTS A BAND OF LIGHT REFLECTIVITIES MOVING
INTO WESTERN NORTH DAKOTA AROUND 08 UTC SUNDAY. HOWEVER...ANY
MEASURABLE PRECIPITATION REMAINS CONFINED TO THE FAR NORTHWEST
CORNER OF NORTH DAKOTA. THE RAP MAINTAINS THE LIGHT REFLECTIVITIES
AS THEY CROSS THE CWA BUT KEEPS MAINLY TRACE AMOUNTS...AND MAINLY
CONFINED TO THE FAR NORTHERN TIER COUNTIES. THE GFS/EC/GEM ALL
BRING VERY LIGHT QPF INTO THE FAR NORTHWEST THROUGH 12 UTC. THE
EC/GEM ALSO TRACK SOME TRACE AMOUNTS ALONG THE NORTHERN TIER
COUNTIES THROUGH THE MORNING. THE GFS IS FARTHER SOUTH AND IS ON
THE SOUTHERN SIDE OF THE ENVELOPE OF DETERMINISTIC SOLUTIONS. THUS
HAVE KEPT BEST CHANCE FOR QPF IN THE FAR NORTHWEST 06-12 UTC
SUNDAY AND ACROSS THE FAR NORTHERN TIER COUNTIES 12-18 UTC SUNDAY.
WILL STILL HAVE A MENTION OF SOME FREEZING RAIN SOUTHWEST AND
SOUTH CENTRAL (MAINLY ALONG AND NORTH OF I-94) BUT WITH NO
SIGNIFICANT ACCUMULATIONS. EVEN ACROSS THE NORTH...DETERMINISTIC
MODEL QPF REMAINS AT OR BELOW A HUNDREDTH OF AN INCH. ONLY A
LITTLE FREEZING RAIN CAN CAUSE SIGNIFICANT TRAVEL ISSUES. BUT WITH
LOW MODEL QPF...WILL HOLD OFF ON ANY HIGHLIGHTS AT THIS TIME. WE
WILL STILL HAVE TIME TO WATCH THINGS DEVELOP ACROSS NORTHEAST
MONTANA AND SOUTHERN SASKATCHEWAN THIS EVENING AND OVERNIGHT.
COULD STILL SEE A VERY LIGHT MIX OVER THE NORTH CENTRAL MONDAY
AFTERNOON. BUT WESTERN NORTH DAKOTA WILL BE ON THE BACK SIDE OF THE
MID LEVEL TROUGH WITH COLD ADVECTION TRACKING SOUTHEAST ACROSS THE
CWA DURING THE AFTERNOON. THUS THE WEST WILL QUICKLY TRANSITION TO
SNOW AND THE SOUTH CENTRAL SHOULD WARM UP ENOUGH TO SEE ALL RAIN
WITH A QUICK CHANGE TO SNOW AS THE COLD ADVECTION ARRIVES.
IT WILL ALSO BECOME BREEZY TO WINDY SUNDAY AFTERNOON FROM WEST TO
EAST BEHIND THE TRACK OF THE LOW. STRONGEST WINDS 20-30 MPH WITH
GUSTS TO 35 MPH WILL SPREAD FROM THE SOUTHWEST SUNDAY AFTERNOON INTO
THE CENTRAL LATE AFTERNOON TO EARLY EVENING. HIGHS SUNDAY WILL
LIKELY BE REACHED IN THE MORNING NORTH TO EARLY AFTERNOON SOUTH WITH
TEMPERATURES FALLING MID TO LATE AFTERNOON EVERYWHERE.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 333 PM CST SAT DEC 6 2014
POST FRONTAL NORTHWEST WINDS OF 20 TO 30 MPH ALONG WITH ISOLATED TO
SCATTERED SNOW SHOWERS WILL DOMINATE SUNDAY NIGHT. THE ENTIRE SYSTEM
DEPARTS CENTRAL NORTH DAKOTA BY 12Z MONDAY WITH COLDER AIR REMAINING
IN PLACE FOR THE MORNING FOLLOWED BY WARM AIR ADVECTION MONDAY
AFTERNOON ESPECIALLY IN THE WEST. A PROGRESSIVE PATTERN CONTINUES
WITH A TRANSITORY RIDGE SHIFTING THROUGH MONDAY NIGHT FOLLOWED BY A
DRY SHORTWAVE TROUGH PASSING THROUGH TUESDAY. THEREAFTER...UPPER
RIDGING DOMINATES AND SHIFTS EAST BY MIDWEEK ALLOWING A SOUTHWEST
FLOW TO RETURN. HOWEVER NOTHING FORESEEN IN THE SOUTHWEST FLOW IN
TERMS OF SIGNIFICANT SHORTWAVES AT LEAST THROUGH SATURDAY PER
GFS/GEM GLOBAL/SUPERBLEND. HOWEVER THE LATEST ECMWF PUSHES A FAST
MOVING SHORTWAVE AND CONSEQUENTLY LIGHT PRECIPITATION/FAVORING RAIN
SHOWERS AT THIS POINT...ACROSS THE NORTH THURSDAY. HIGH TEMPERATURES
WILL WARM TO BETWEEN 35F AND 45F WEDNESDAY THROUGH FRIDAY...THEN A
BIT COOLER FOR SATURDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 333 PM CST SAT DEC 6 2014
VFR CONDITIONS THIS AFTERNOON AND TONIGHT. A LOW PRESSURE SYSTEM
WILL MOVE INTO THE AREA BY SUNDAY MORNING. COULD SEE A VERY BRIEF
PERIOD OF FREEZING RAIN AHEAD OF THE SYSTEM. ALTHOUGH WITH ONLY
SLIGHT CHANCES...WILL NOT ADD THE FZRA TO THE TAFS. SUNDAY WINDS
WILL SHIFT WEST TO NORTHWEST AND INCREASE...WITH INCREASING MVFR
CLOUDS AND A CHANCE OF SNOW SHOWERS...BUT MAINLY AFTER 18 UTC.
WILL BRING A SCATTERED MVFR LAYER INTO THE WEST AND NORTH LATE IN
THE FORECAST PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...TWH
LONG TERM...KS
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1249 PM CST SAT DEC 6 2014
.UPDATE...
ISSUED AT 1249 PM CST SAT DEC 6 2014
CLOUDS CONTINUE OVER MUCH OF THE REGION...WITH THE WESTERN EDGE OF
THE DECK NOT MOVING INTO OUR CWA UNTIL LATE AFTERNOON. MADE ONLY A
FEW MINOR TWEAKS TO CLOUDS. THERE CONTINUE TO BE A FEW RADAR
RETURNS OVER THE REGION...BUT NOTHING IS REACHING THE GROUND AND
ONLY MID LEVEL CLOUDS HAVE BEEN REPORTED. WILL LET FLURRY MENTION
GO AWAY FOR THE AFTERNOON AS PLANNED. WILL CONTINUE TO KEEP TEMPS
CLIMBING INTO THE 20S AS EVEN WITH CLOUDS WE ARE UPPER TEENS TO
LOW 20S AT THE CURRENT HOUR.
UPDATE ISSUED AT 950 AM CST SAT DEC 6 2014
CLOUDS CONTINUE TO SPREAD ACROSS THE CWA AS SEEN ON SATELLITE AND
WEB CAMS...SO INCREASED CLOUD COVER FOR MUCH OF THE DAY. WE COULD
START SEEING SOME BREAKS IN THE WEST LATE AS THE EDGE OF THE CLOUD
DECK APPROACHES. THERE HAS BEEN A FEW FLURRIES REPORTED NEAR THE
WESTERN CWA BORDER SO INCLUDED AN ISOLATED MENTION THROUGH THE
NEXT FEW HOURS. LOWERED HIGHS A DEGREE OR SO WITH INCREASED
CLOUDS...BUT STILL THINK WE SHOULD GET INTO THE 20S.
UPDATE ISSUED AT 655 AM CST SAT DEC 6 2014
THERE HAS BEEN PATCHY DENSE FOG DEVELOP OVER THE PAST FEW
HOURS...BUT QUICKLY DISSIPATE ONCE MID-HIGH CLOUDS COME OVERHEAD.
THE ONLY UPDATE IS FOR THE SKY GRID TO ACCOUNT FOR MID-LEVEL
CLOUDS SPREADING OVER THE REGION A BIT FASTER THAN ANTICIPATED
(FOLLOWED THE RAP 700MB RH FIELD).
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 400 AM CST SAT DEC 6 2014
FREEZING RAIN POTENTIAL ON SUNDAY WILL BE THE MAIN CONCERN FOR
THIS PERIOD. 00Z MODELS IN DECENT AGREEMENT...ALTHOUGH DIFFERENCES
IN THERMAL PROFILES WILL MAKE FOR A CHALLENGING FORECAST.
HIGH PRESSURE PROPAGATES ACROSS THE REGION TODAY WITH SOUTHERLY
RETURN FLOW SETTING UP THIS AFTERNOON. SATELLITE IMAGERY AND
OBSERVATIONS INDICATE PATCHY FOG DEVELOPING...AND WILL NEED TO
MONITOR (DID INCLUDE PATCHY FOG IN THE FORECAST FOR SOME
LOCATIONS). WEAK SYSTEM WILL BE PROPAGATING ACROSS SOUTHERN CANADA
TODAY...AND ALTHOUGH THE STRONGEST FORCING WILL BE NORTH OF THE
INTERNATIONAL BORDER...DO EXPECT AN AREA OF CLOUDS TO MOVE
THROUGH THE REGION. THE TEMPERATURE FORECAST IS A BIT TRICKY. MOST
AREAS SHOULD BE ABLE TO RISE INTO THE 20S THIS AFTERNOON...THEN
AFTER A BRIEF DIP IN VALUES...STRONGER WARM AIR ADVECTION
COMMENCES TONIGHT AND ANTICIPATE SLOWLY RISING VALUES.
MAJORITY OF MODEL GUIDANCE IS INDICATING A STRONGER SIGNAL FOR
FREEZING RAIN SUNDAY MORNING...ESPECIALLY THE SOUTHERN VALLEY INTO
WEST CENTRAL MINNESOTA AND PORTIONS OF NORTHWEST MINNESOTA (MAINLY
ALONG AND EAST OF A LINE FROM WAHPETON TO BAUDETTE). QPF AMOUNTS
LIKELY AROUND 0.10 INCHES. THE GENERAL IDEA IS THAT EVAPORATIVE
COOLING WILL TRANSITION A FREEZING RAIN/SLEET MIX TO SNOW...BUT
GIVEN THE SREF P-TYPE PROBABILITIES (VERY HIGH FREEZING RAIN
PROBABILITIES)...THE THOUGHT IS THAT THE OPERATIONAL MODELS MAY
BE EVAPORATIVELY COOLING TOO QUICKLY (WHICH DOES HAPPEN) AND/OR
TOO DRY ALOFT. IF CONFIDENCE INCREASES IN THE EXPECTED THERMAL
PROFILE...ALONG WITH SFC TEMPERATURES REMAINING BELOW
FREEZING...SOME SORT OF ADVISORY MAY BE NEEDED FOR THIS AREA.
OTHERWISE...AREAS TO THE WEST WILL LIKELY BE WELL INTO THE 30S ON
SUNDAY AND MOSTLY DRY.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 400 AM CST SAT DEC 6 2014
SUNDAY NIGHT-MONDAY NIGHT...DEFORMATION ZONE SNOW SHOWERS SUNDAY
NIGHT INTO THE EARLY PORTIONS OF MONDAY AS THE SYSTEM FROM THE
SHORT TERM PERIOD MOVES AWAY FROM THE REGION. HIGH PRESSURE BUILDS
INTO THE REGION BY LATER MONDAY. ANTICIPATE A COLDER AIRMASS WITH
TEMPERATURES NEAR NORMAL (THE HIGHS ON MONDAY MAY OCCUR IN THE
MORNING).
TUESDAY-FRIDAY...EXTENDED PERIOD BEGINS UNDER NORTHWEST FLOW AND
NEAR AVERAGE TEMPERATURES FOR THE FIRST HALF OF DECEMBER.
AFTERWARDS GUIDANCE DIFFERS ON TIMING AND PLACEMENT OF SHORT WAVE
ENERGY RIDING THROUGH UPPER RIDGE DURING THE MIDDLE OF THE WEEK.
ECMWF PREFERS TO KEEP WAVE OVER SOUTHERN CANADA WHILE GFS IS
FARTHER SOUTH CLOSER TO THE NORTHERN/CENTRAL PLAINS INTERFACE. GFS
IS TYPICALLY A BIT FASTER WITH THIS FEATURE AND THE WEAK SHORT
WAVE IS NOT EXPECTED TO HAVE A GREAT IMPACT ON FORECAST. THE EARLY
PERIOD AVERAGE TEMPERATURES WILL BEGIN TO WARM FROM WEDNESDAY
THROUGH FRIDAY AS RETURN FLOW/WARM ADVECTION INCREASES WITH A
SHORT WAVE RIDGE BUILDING INTO THE FORECAST AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1249 PM CST SAT DEC 6 2014
MID-LEVEL VFR CLOUD DECK IN THE 5-8 KFT RANGE WILL CLEAR FROM WEST
TO EAST LATE THIS AFTERNOON AND EVENING...WITH HIGH CIRRUS STREAMING
IN FROM THE WEST BY LATE TODAY. AS SFC LOW PRESSURE TO THE WEST
APPROACHES...SOUTH/SOUTHEAST WINDS WILL STRENGTHEN THIS
EVENING...PERHAPS A BIT GUSTY AT TIMES...DESPITE SHALLOW VERTICAL
MIXING. MOISTURE WILL SPREAD NORTHWARD BY EARLY SUNDAY...LIKELY
SPREADING LOW CLOUDS INTO THE REGION. FOR NOW TRENDED TO MVFR...BUT
BASED ON CURRENT OBS TO THE SOUTH AND MODEL GUIDANCE...IFR
CONDITIONS CERTAINLY A GOOD POSSIBILITY WITH PERHAPS SOME REDUCED
VSBYS AS WELL. EXACT TIMING OF ARRIVAL OF THE LOWER CEILINGS AT EACH
SITE REMAINS SOMEWHAT UNCERTAIN. SOME LIGHT SLEET/FZRA MAY AFFECT
ESPECIALLY KBJI BY LATE IN THE TAF PERIOD...WITH LOWER CONFIDENCE IN
PRECIP WESTWARD AT KFAR...KTVF...AND KGFK.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...JR
SHORT TERM...TG
LONG TERM...WJB/TG
AVIATION...MAKOWSKI
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
951 AM CST SAT DEC 6 2014
.UPDATE...
ISSUED AT 950 AM CST SAT DEC 6 2014
CLOUDS CONTINUE TO SPREAD ACROSS THE CWA AS SEEN ON SATELLITE AND
WEB CAMS...SO INCREASED CLOUD COVER FOR MUCH OF THE DAY. WE COULD
START SEEING SOME BREAKS IN THE WEST LATE AS THE EDGE OF THE CLOUD
DECK APPROACHES. THERE HAS BEEN A FEW FLURRIES REPORTED NEAR THE
WESTERN CWA BORDER SO INCLUDED AN ISOLATED MENTION THROUGH THE
NEXT FEW HOURS. LOWERED HIGHS A DEGREE OR SO WITH INCREASED
CLOUDS...BUT STILL THINK WE SHOULD GET INTO THE 20S.
UPDATE ISSUED AT 655 AM CST SAT DEC 6 2014
THERE HAS BEEN PATCHY DENSE FOG DEVELOP OVER THE PAST FEW
HOURS...BUT QUICKLY DISSIPATE ONCE MID-HIGH CLOUDS COME OVERHEAD.
THE ONLY UPDATE IS FOR THE SKY GRID TO ACCOUNT FOR MID-LEVEL
CLOUDS SPREADING OVER THE REGION A BIT FASTER THAN ANTICIPATED
(FOLLOWED THE RAP 700MB RH FIELD).
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 400 AM CST SAT DEC 6 2014
FREEZING RAIN POTENTIAL ON SUNDAY WILL BE THE MAIN CONCERN FOR
THIS PERIOD. 00Z MODELS IN DECENT AGREEMENT...ALTHOUGH DIFFERENCES
IN THERMAL PROFILES WILL MAKE FOR A CHALLENGING FORECAST.
HIGH PRESSURE PROPAGATES ACROSS THE REGION TODAY WITH SOUTHERLY
RETURN FLOW SETTING UP THIS AFTERNOON. SATELLITE IMAGERY AND
OBSERVATIONS INDICATE PATCHY FOG DEVELOPING...AND WILL NEED TO
MONITOR (DID INCLUDE PATCHY FOG IN THE FORECAST FOR SOME
LOCATIONS). WEAK SYSTEM WILL BE PROPAGATING ACROSS SOUTHERN CANADA
TODAY...AND ALTHOUGH THE STRONGEST FORCING WILL BE NORTH OF THE
INTERNATIONAL BORDER...DO EXPECT AN AREA OF CLOUDS TO MOVE
THROUGH THE REGION. THE TEMPERATURE FORECAST IS A BIT TRICKY. MOST
AREAS SHOULD BE ABLE TO RISE INTO THE 20S THIS AFTERNOON...THEN
AFTER A BRIEF DIP IN VALUES...STRONGER WARM AIR ADVECTION
COMMENCES TONIGHT AND ANTICIPATE SLOWLY RISING VALUES.
MAJORITY OF MODEL GUIDANCE IS INDICATING A STRONGER SIGNAL FOR
FREEZING RAIN SUNDAY MORNING...ESPECIALLY THE SOUTHERN VALLEY INTO
WEST CENTRAL MINNESOTA AND PORTIONS OF NORTHWEST MINNESOTA (MAINLY
ALONG AND EAST OF A LINE FROM WAHPETON TO BAUDETTE). QPF AMOUNTS
LIKELY AROUND 0.10 INCHES. THE GENERAL IDEA IS THAT EVAPORATIVE
COOLING WILL TRANSITION A FREEZING RAIN/SLEET MIX TO SNOW...BUT
GIVEN THE SREF P-TYPE PROBABILITIES (VERY HIGH FREEZING RAIN
PROBABILITIES)...THE THOUGHT IS THAT THE OPERATIONAL MODELS MAY
BE EVAPORATIVELY COOLING TOO QUICKLY (WHICH DOES HAPPEN) AND/OR
TOO DRY ALOFT. IF CONFIDENCE INCREASES IN THE EXPECTED THERMAL
PROFILE...ALONG WITH SFC TEMPERATURES REMAINING BELOW
FREEZING...SOME SORT OF ADVISORY MAY BE NEEDED FOR THIS AREA.
OTHERWISE...AREAS TO THE WEST WILL LIKELY BE WELL INTO THE 30S ON
SUNDAY AND MOSTLY DRY.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 400 AM CST SAT DEC 6 2014
SUNDAY NIGHT-MONDAY NIGHT...DEFORMATION ZONE SNOW SHOWERS SUNDAY
NIGHT INTO THE EARLY PORTIONS OF MONDAY AS THE SYSTEM FROM THE
SHORT TERM PERIOD MOVES AWAY FROM THE REGION. HIGH PRESSURE BUILDS
INTO THE REGION BY LATER MONDAY. ANTICIPATE A COLDER AIRMASS WITH
TEMPERATURES NEAR NORMAL (THE HIGHS ON MONDAY MAY OCCUR IN THE
MORNING).
TUESDAY-FRIDAY...EXTENDED PERIOD BEGINS UNDER NORTHWEST FLOW AND
NEAR AVERAGE TEMPERATURES FOR THE FIRST HALF OF DECEMBER.
AFTERWARDS GUIDANCE DIFFERS ON TIMING AND PLACEMENT OF SHORT WAVE
ENERGY RIDING THROUGH UPPER RIDGE DURING THE MIDDLE OF THE WEEK.
ECMWF PREFERS TO KEEP WAVE OVER SOUTHERN CANADA WHILE GFS IS
FARTHER SOUTH CLOSER TO THE NORTHERN/CENTRAL PLAINS INTERFACE. GFS
IS TYPICALLY A BIT FASTER WITH THIS FEATURE AND THE WEAK SHORT
WAVE IS NOT EXPECTED TO HAVE A GREAT IMPACT ON FORECAST. THE EARLY
PERIOD AVERAGE TEMPERATURES WILL BEGIN TO WARM FROM WEDNESDAY
THROUGH FRIDAY AS RETURN FLOW/WARM ADVECTION INCREASES WITH A
SHORT WAVE RIDGE BUILDING INTO THE FORECAST AREA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 655 AM CST SAT DEC 6 2014
AREA OF VFR CIGS WILL MOVE ACROSS THE REGION TODAY. LIGHT AND
VARIABLE WINDS WILL BECOME SOUTHERLY THIS AFTERNOON AND COULD BE A
BIT BREEZY THIS EVENING AND OVERNIGHT.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...JR
SHORT TERM...TG
LONG TERM...WJB/TG
AVIATION...TG
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
655 AM CST SAT DEC 6 2014
.UPDATE...
ISSUED AT 655 AM CST SAT DEC 6 2014
THERE HAS BEEN PATCHY DENSE FOG DEVELOP OVER THE PAST FEW
HOURS...BUT QUICKLY DISSIPATE ONCE MID-HIGH CLOUDS COME OVERHEAD.
THE ONLY UPDATE IS FOR THE SKY GRID TO ACCOUNT FOR MID-LEVEL
CLOUDS SPREADING OVER THE REGION A BIT FASTER THAN ANTICIPATED
(FOLLOWED THE RAP 700MB RH FIELD).
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 400 AM CST SAT DEC 6 2014
FREEZING RAIN POTENTIAL ON SUNDAY WILL BE THE MAIN CONCERN FOR
THIS PERIOD. 00Z MODELS IN DECENT AGREEMENT...ALTHOUGH DIFFERENCES
IN THERMAL PROFILES WILL MAKE FOR A CHALLENGING FORECAST.
HIGH PRESSURE PROPAGATES ACROSS THE REGION TODAY WITH SOUTHERLY
RETURN FLOW SETTING UP THIS AFTERNOON. SATELLITE IMAGERY AND
OBSERVATIONS INDICATE PATCHY FOG DEVELOPING...AND WILL NEED TO
MONITOR (DID INCLUDE PATCHY FOG IN THE FORECAST FOR SOME
LOCATIONS). WEAK SYSTEM WILL BE PROPAGATING ACROSS SOUTHERN CANADA
TODAY...AND ALTHOUGH THE STRONGEST FORCING WILL BE NORTH OF THE
INTERNATIONAL BORDER...DO EXPECT AN AREA OF CLOUDS TO MOVE
THROUGH THE REGION. THE TEMPERATURE FORECAST IS A BIT TRICKY. MOST
AREAS SHOULD BE ABLE TO RISE INTO THE 20S THIS AFTERNOON...THEN
AFTER A BRIEF DIP IN VALUES...STRONGER WARM AIR ADVECTION
COMMENCES TONIGHT AND ANTICIPATE SLOWLY RISING VALUES.
MAJORITY OF MODEL GUIDANCE IS INDICATING A STRONGER SIGNAL FOR
FREEZING RAIN SUNDAY MORNING...ESPECIALLY THE SOUTHERN VALLEY INTO
WEST CENTRAL MINNESOTA AND PORTIONS OF NORTHWEST MINNESOTA (MAINLY
ALONG AND EAST OF A LINE FROM WAHPETON TO BAUDETTE). QPF AMOUNTS
LIKELY AROUND 0.10 INCHES. THE GENERAL IDEA IS THAT EVAPORATIVE
COOLING WILL TRANSITION A FREEZING RAIN/SLEET MIX TO SNOW...BUT
GIVEN THE SREF P-TYPE PROBABILITIES (VERY HIGH FREEZING RAIN
PROBABILITIES)...THE THOUGHT IS THAT THE OPERATIONAL MODELS MAY
BE EVAPORATIVELY COOLING TOO QUICKLY (WHICH DOES HAPPEN) AND/OR
TOO DRY ALOFT. IF CONFIDENCE INCREASES IN THE EXPECTED THERMAL
PROFILE...ALONG WITH SFC TEMPERATURES REMAINING BELOW
FREEZING...SOME SORT OF ADVISORY MAY BE NEEDED FOR THIS AREA.
OTHERWISE...AREAS TO THE WEST WILL LIKELY BE WELL INTO THE 30S ON
SUNDAY AND MOSTLY DRY.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 400 AM CST SAT DEC 6 2014
SUNDAY NIGHT-MONDAY NIGHT...DEFORMATION ZONE SNOW SHOWERS SUNDAY
NIGHT INTO THE EARLY PORTIONS OF MONDAY AS THE SYSTEM FROM THE
SHORT TERM PERIOD MOVES AWAY FROM THE REGION. HIGH PRESSURE BUILDS
INTO THE REGION BY LATER MONDAY. ANTICIPATE A COLDER AIRMASS WITH
TEMPERATURES NEAR NORMAL (THE HIGHS ON MONDAY MAY OCCUR IN THE
MORNING).
TUESDAY-FRIDAY...EXTENDED PERIOD BEGINS UNDER NORTHWEST FLOW AND
NEAR AVERAGE TEMPERATURES FOR THE FIRST HALF OF DECEMBER.
AFTERWARDS GUIDANCE DIFFERS ON TIMING AND PLACEMENT OF SHORT WAVE
ENERGY RIDING THROUGH UPPER RIDGE DURING THE MIDDLE OF THE WEEK.
ECMWF PREFERS TO KEEP WAVE OVER SOUTHERN CANADA WHILE GFS IS
FARTHER SOUTH CLOSER TO THE NORTHERN/CENTRAL PLAINS INTERFACE. GFS
IS TYPICALLY A BIT FASTER WITH THIS FEATURE AND THE WEAK SHORT
WAVE IS NOT EXPECTED TO HAVE A GREAT IMPACT ON FORECAST. THE EARLY
PERIOD AVERAGE TEMPERATURES WILL BEGIN TO WARM FROM WEDNESDAY
THROUGH FRIDAY AS RETURN FLOW/WARM ADVECTION INCREASES WITH A
SHORT WAVE RIDGE BUILDING INTO THE FORECAST AREA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 655 AM CST SAT DEC 6 2014
AREA OF VFR CIGS WILL MOVE ACROSS THE REGION TODAY. LIGHT AND
VARIABLE WINDS WILL BECOME SOUTHERLY THIS AFTERNOON AND COULD BE A
BIT BREEZY THIS EVENING AND OVERNIGHT.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...TG
SHORT TERM...TG
LONG TERM...WJB/TG
AVIATION...TG
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1243 AM CST SAT DEC 6 2014
.UPDATE...
ISSUED AT 1242 AM CST SAT DEC 6 2014
CHANGES FOR THIS UPDATE INCLUDE...INCREASED OVERNIGHT LOW
TEMPERATURES...INCREASED CLOUD COVER.
LOW STRATUS CONTINUES TO BUILD EAST ACROSS NORTH DAKOTA. THIS
THICK STRATUS DECK HAS INHIBITED DIURNAL COOLING.
THEREFORE...INCREASED OVERNIGHT LOW TEMPERATURES FOR LOCATIONS
UNDER THIS CLOUD DECK. SPEAKING OF CLOUDS...INCREASED COVERAGE AND
DURATION OF THE CLOUD COVER THROUGH THE MORNING EARLY MORNING
HOURS. LATEST SATELLITE TRENDS AND SHORT-TERM GUIDANCE SUGGESTS
THIS THICK CLOUD COVER WILL REMAIN ENTRENCHED OVER NORTH DAKOTA
UNTIL LATER THIS MORNING WHEN WAA ADVECTION KICKS IN IN ERNEST.
A SCATTERED LIGHT WINTRY MIX CONTINUES ACROSS PORTIONS OF
SOUTHWEST NORTH DAKOTA WHERE WARMER AIR ALOFT HAS PUSHED NORTH.
WILL MONITOR THIS DEVELOPMENT AS ADJUSTMENTS MAY BE NEEDED TO THE
PRECIP FORECAST FOR THE EARLY MORNING HOURS.
UPDATE ISSUED AT 923 PM CST FRI DEC 5 2014
FOR LATE EVENING UPDATE MAIN CONCERN WAS PRECIPITATION OVER THE
FAR SOUTHWEST. LATEST HIGH-RES MODELS WERE HAVING SOME TROUBLE ON
PLACEMENT OF PRECIPITATION THIS EVENING...BUT REGIONAL RADAR
MOSAIC ALONG WITH BOWMAN ARB RADAR INDICATED VERY LIGHT
PRECIPITATION SHIFTING TOWARDS WEST CENTRAL AND SOUTHWEST NORTH
DAKOTA. THEREFORE...HAVE SPREAD LOW POPS THROUGH THE SOUTHWEST.
NEXT CONCERN WAS PRECIP TYPE AS SOME WARMER AIR ALOFT IS STARTING
TO PUSH TOWARDS THE FAR SOUTHWEST. WITH THIS...HAVE ADDED THE
MENTION OF POSSIBLE SLEET/FREEZING RAIN...ALTHOUGH CHANCES AND
COVERAGE WILL BE VERY LOW. ONLY OTHER CHANGE FOR UPDATE WAS
DROPPING LOW TEMPERATURES A BIT OVER THE NORTHWEST/NORTH CENTRAL
AS OBBS JUST NORTH OF THE CANADIAN BORDER HAVE ALREADY DIPPED DOWN
TOWARDS ZERO. UPDATES HAVE BEEN SENT.
UPDATE ISSUED AT 621 PM CST FRI DEC 5 2014
MAIN CHANGE FOR EARLY EVENING UPDATE WAS TO INCREASE CLOUD COVER
ACROSS ALL AREAS EXCEPT FAR SOUTH CENTRAL/JAMES RIVER VALLEY AS
BROAD AREA CONTINUES TO SHIFT SOUTHEAST. WILL HAVE TO KEEP AN
EYE ON TEMPERATURES THROUGH THE EVENING AS WHEREVER THERE ARE
BREAKS IN THE CLOUD COVER OVER THE NORTH...THE TEMPERATURE HAS
DROPPED QUICKLY. UPDATES HAVE BEEN SENT.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 322 PM CST FRI DEC 5 2014
CURRENTLY...HIGH PRESSURE OVER NORTHWEST NORTH DAKOTA THIS EARLY
AFTERNOON IS FORECAST TO MOVE EAST ACROSS THE FORECAST AREA
TONIGHT. IFR STRATUS REMAINS OVER NORTHWEST NORTH DAKOTA FROM
CROSBY AND WILLISTON...EAST TO STANLEY...BUT HAVING A HARD TIME
MAKING IT MUCH FARTHER EAST THIS AFTERNOON. TEMPERATURES RANGED
FROM THE UPPER TEENS-LOW 20S NORTH TO UPPER 20S-LOW 30S SOUTH.
MAIN CONCERN FOR THE SHORT TERM PERIOD IS STRATUS/FOG
POSSIBILITIES AND POSSIBLE LIGHT PRECIPITATION ACROSS THE NORTH.
THE 05 DEC 12 UTC NAM AND MESOSCALE MODELS HAVE BEEN HINTING AT A
BAND OF LIGHT PRECIPITATION MOVING ACROSS NORTHERN NORTH DAKOTA
LATE TONIGHT INTO SATURDAY MORNING. THE 18 UTC NAM HAS DISPLACED
THE PRECIPITATION FARTHER SOUTH...BUT RAP/HRRR HAVE BEEN PRETTY
CONSISTENT IN KEEPING VERY LIGHT PRECIPITATION ACROSS THE NORTH.
HAVE ADDED SOME SLIGHT CHANCE POPS NORTHWEST AND NORTH CENTRAL
LATER THIS EVENING INTO SATURDAY MORNING...TAPERING TO ONLY
FLURRIES AS PRECIPITATION MOVES FROM NORTH CENTRAL INTO NORTHEAST
ND. HAVE KEPT PRECIPITATION ALL SNOW AS IT LOOKS LIKE THE WARMER
TEMPERATURES ALOFT DO NOT ARRIVE UNTIL BEST FORCING HAS ALREADY
PASSED...THUS PRECIP SHOULD REMAIN ALL SNOW.
MESOSCALE MODELS CONTINUE TO SHOW INCREASING LOW LEVEL MOISTURE
ACROSS THE NORTH AND EAST THIS AFTERNOON AND THIS EVENING...THEN
POSSIBLY SHIFTING MORE TO THE SOUTHWEST LATER TONIGHT AS SOUTHEAST
FLOW KICKS IN ON THE BACK SIDE OF THE SURFACE HIGH. HAVE OPTED TO
MENTION PATCHY FOG TONIGHT AS RAP BUFR SOUNDINGS DO SUGGEST FOG
MOST AREAS. ALSO HAVE BUMPED UP SKY COVER LATE EVENING THROUGH
SATURDAY MORNING. TEMPERATURES ALSO TRICKY AS WE WILL LIKELY SEE A
QUICK DROP THIS EVENING EAST WITH RISING TEMPERATURES LATE.
PERHAPS A QUICK DROP CENTRAL/WEST WITH RISING TEMPERATURES LATE
EVENING INTO THE OVERNIGHT AND THEN DROPPING OFF BY MORNING.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 322 PM CST FRI DEC 5 2014
SATURDAY NIGHT THROUGH SUNDAY NIGHT...AN UPPER LEVEL LOW/SHARP
TROUGH WITH AN ASSOCIATED SURFACE COLD FRONT WILL PUSH ACROSS
WESTERN AND CENTRAL NORTH DAKOTA SUNDAY INTO SUNDAY NIGHT. SOUTH TO
SOUTHWESTERLY FLOW AHEAD OF THIS SYSTEM WILL ALLOW FOR WARMING
THROUGH SUNDAY MORNING. THE H85 BAROCLINIC ZONE BEGINS TO PUSH
ACROSS THE FAR WEST BY 18Z AND THEN SHIFTS INTO CENTRAL NORTH DAKOTA
SUNDAY AFTERNOON/EVENING. STILL SOME THREAT OF A WINTRY MIX ACROSS
NORTHERN NORTH DAKOTA...BUT IT APPEARS THE BETTER CHANCE FOR
PRECIPITATION MAY OCCUR SUNDAY EVENING INTO SUNDAY NIGHT ACROSS
NORTHERN NORTH DAKOTA...ASSOCIATED WITH A WEAK/NARROW TROWAL PER GFS
H7-H5 EQUIVALENT POTENTIAL TEMPERATURE. AMOUNTS LOOK VERY
LIGHT...PERHAPS A TENTH OR TWO OF AN INCH OF SNOW. WEST TO NORTHWEST
WINDS INCREASE IN THE WEST DURING THE AFTERNOON WITH THE STRONGEST
WINDS NOT ARRIVING UNTIL SUNDAY NIGHT FOR CENTRAL NORTH DAKOTA.
EXPECT 20 TO 35MPH WINDS DEVELOPING BEHIND THIS SYSTEM. WITH LIMITED
SNOW SHOWERS AND QPF...AT THIS TIME HAVE NOT MENTIONED ANY BLOWING
SNOW.
MONDAY THROUGH FRIDAY...BRISK NORTHWEST WINDS CONTINUE DURING THE
DAY MONDAY BUT ABATE MONDAY EVENING. COLDER MONDAY AFTERNOON WITH
HIGHS 20 NORTHEAST TO MID 30S FAR SOUTHWEST. THEREAFTER A
PROGRESSIVE PATTERN ENSUES WITH NO SIGNIFICANT SHORTWAVES FORECAST
THROUGH THE REMAINDER OF THE LONG TERM PERIOD. A WARMING TREND IS
STILL IN THE FORECAST WITH HIGHS 35F TO 45F WEDNESDAY THROUGH
FRIDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1242 AM CST SAT DEC 6 2014
IFR CIGS WILL CONTINUE OVER NORTH CENTRAL NORTH DAKOTA THROUGH
MUCH OF THE NIGHT...AFFECTING KMOT. ELSEWHERE VFR TO MVFR CIGS
CAN BE EXPECTED. PATCHY FOG MAY DEVELOP OVERNIGHT AT SOME OR ALL
TERMINALS...WITH KMOT/KJMS MOST LIKELY TO SEE FOG.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AJ
SHORT TERM...TWH
LONG TERM...KS
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
316 PM EST SAT DEC 6 2014
.SYNOPSIS...
LOW PRESSURE WAVE PASSES WITH COLDER AIR IN ITS WAKE TONIGHT.
HIGH PRESSURE SUNDAY. UPPER TROUGH MONDAY NIGHT/TUESDAY. COLDER
AIR TUESDAY NIGHT INTO WEDNESDAY.
&&
.NEAR TERM /THROUGH SUNDAY/...
AS OF 18Z THE FRONT HAS CLEARED CRW AND CKB WITH SURFACE LOW E OF
EKN. FRONT WILL CLEAR THE MOUNTAINS BY 21Z. AS THE FRONT
CROSSES...TEMPERATURE FALLS OF 7 TO 10 DEGREES CAN BE EXPECTED
WITH GRADUALLY LOWERING TEMPS THEREAFTER THROUGH THE EVENING. LOW
CIGS AND VSBY IN POST FRONTAL DZ CAN BE EXPECTED THRU THE
REMAINDER OF THE AFTERNOON...ALONG WITH GUSTY NW WINDS. WILL WATCH
-RA TO FILL BACK IN LATER THIS AFTERNOON AS THE UPPER LEVEL TROF
CROSSES. AREA WILL BEGIN TO DRY OUT WITH PASSAGE OF THE UPPER
LEVEL TROF...SAVE FOR SOME DZ HANGING ON ACROSS THE MOUNTAINS THIS
EVENING. ELECTED TO KEEP POSSIBILITY OF IT ENDING AS A LITTLE FRZ
DZ BUT NOT EXPECTING ANY IMPACTS.
WHAT WILL NOT CLEAR OUT THIS EVENING IS THE LOW STRATUS.
HOWEVER...DO EXPECT BASES TO LIFT A BIT TONIGHT. THINK SE OH WILL
SCT OUT DURING THE PREDAWN. HOWEVER...DEVELOPING SUBSIDENCE
INVERSION BENEATH THIS LINGERING MOISTURE WILL MAKE IT VERY
DIFFICULT FOR STRATUS TO BREAK UP E OF THE OH RIVER OVERNIGHT. WITH WEAK
CAA BENEATH THE INVERSION AND LOW LEVEL WINDS BECOMING MORE
NE...FELT IT NECESSARY TO HOLD THE STRATUS IN ALONG THE
CLIMATOLOGICAL FAVORED AREAS IN THIS SETUP....IE THE C LOWLANDS
AND COAL FIELDS THRU THE MORNING HOURS. CLOUDS WILL GRADUALLY SCT
OUT FROM NE TO SW...WITH AREAS ALONG AND S OF I64 CORRIDOR THE
LAST TO LOSE THE STRATUS...POSSIBLY HOLDING ON UNTIL LATE
AFTERNOON.
FOR TEMPS...USED A BLEND OF LAMP AND HRRR FOR TEMPS TONIGHT. FOR
SUNDAY...USED MET AS A BASE WHICH BETTER REFLECTED EXPECTED COOLER
READINGS ALONG AND ESPECIALLY S OF I64 CORRIDOR DUE TO CLOUDS.
FURTHER N...FELT LOCAL MOS WAS THE WAY TO GO WHERE READINGS SHOULD
REACH INTO THE MID OR UPPER 40S.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
STRONG MID LEVEL RIDGING AND HIGH PRESSURE INFLUENCES FROM EASTERN
CANADA DOMINATE SUNDAY...BUT SUNSHINE STILL LIMITED TO THE MORNING
HOURS WITH CIRRUS AHEAD OF THE UPPER LEVEL TROUGH DIGGING IN OVER
THE WESTERN GREAT LAKES. MODELS NOW SETTLING ON THE TROUGH AXIS
HOLDING THE DEVELOPING COASTAL SYSTEM OFFSHORE AND MAINLY AWAY FROM
OUR EASTERN MOST RIDGES...BUT WILL STILL ENTERTAIN SOME LOW END POPS
FOR THE FAR EASTERN PORTIONS OF RAND/POCA COUNTIES. SOME ICING IS
POSSIBLE IN THE SOUTHEAST UPSLOPE AREAS.
HAVE THE TRANSITION TO SNOW FOR THE LOWLAND UPSLOPE AREAS FROM RAIN
TO SNOW A BIT SLOWER...AND JUST BEGINNING BY THE END OF THE SHORT
TERM FORECAST AT 00Z WEDNESDAY. 925MB TEMPERATURES GO BELOW 0C JUST
AFTER 21Z TUESDAY FOR THE MOUNTAINS...MAKING THE 18Z TO 00Z PERIOD
THE RAIN/SNOW TRANSITION TIMES FOR THE MOUNTAINOUS AREAS. LOWLANDS
WILL TRANSITION TO SNOW LIKELY IN THE BEGINNING FEW HOURS OF THE
LONG TERM.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
USED A BLEND OF THE GFS...GEFS MEAN...ECMWF...ECMWF MEAN...AND
CONTINUITY WITH THE PREVIOUS FORECAST. THIS WOULD HAVE WRAP AROUND
MOISTURE OVER THE REGION FOR TUESDAY NIGHT INTO WEDNESDAY. 850 MB
TEMPERATURES ARE MARGINAL FOR UPSLOPE SNOW...SO COULD SEE DRIZZLE
INSTEAD OF SNOW IN MANY AREAS. A HIGH PRESSURE SYSTEM THEN MOVES IN
FOR THE END OF THE WORK WEEK AND INTO THE WEEKEND...ALLOWING
TEMPERATURES TO MODERATE SOME.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
SURFACE FRONT WAS E OF CRW/CKB AS OF 18Z. EXPECT IT TO CROSS KEKN
AND KBKW BY 20Z. CIGS AND VSBY WILL LOWER INTO IFR OR WORSE FOR A
TIME IN POST FRONTAL DZ ACROSS MUCH OF THE AREA. WINDS WILL ALSO
GUST IN THE 15 TO 20 KT RANGE...A BIT HIGHER WITH ACTUAL FROPA.
ANOTHER ROUND OF SHRA POSSIBLE LATER THIS AFTERNOON AND INTO THE
EARLY EVENING HRS WITH THE PASSAGE OF THE UPPER LEVEL TROF.
ALLOWED TO VSBY TO IMPROVE INTO MVFR AND EVENTUAL VFR OVERNIGHT AS
DRIER AIR ADVECTS IN NEAR THE SURFACE. ALSO ALLOWED CIGS TO LIFT A
BIT INTO MVFR...FOLLOWING PASSAGE OF THE UPPER TROF. STILL HAVE
CIGS BELOW 2 GRAND MARK THOUGH.
THE LOW STRATUS SHOULD SCT OUT ACROSS SE OH OVERNIGHT...BUT WILL
HANG TOUGH E OF THE OH RIVER TO AFFECT THE TAF SITES. THE LOW
LEVEL FLOW WILL BECOME MORE NE OVERNIGHT WITH SOME GUSTS
CONTINUING. THIS COMBINED WITH DEVELOPING SUBSIDENCE INVERSION
WILL KEEP THE LOW STRATUS IN PLACE FIRST HALF OF SUNDAY...WITH
KCRW AND KHTS PERHAPS NOT SCT OUT UNTIL AFTER END OF TAF PERIOD.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z SUNDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING AND EXTENT OF IFR CONDITIONS MAY VARY.
TIMING ERADICATION OF LOW STRATUS MAY VARY...POSSIBLY OCCURRING
MUCH SOONER THAN CURRENTLY FORECAST.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07
EST 1HRLY 15 16 17 18 19 20 21 22 23 00 01 02
CRW CONSISTENCY H M M H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H M M L L L L H H M
EKN CONSISTENCY H L L L L L L L L L L M
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H M M H H H H H M M M M
AFTER 18Z SUNDAY...
IFR POSSIBLE IN RAIN/SNOW MONDAY NIGHT INTO WEDNESDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...RPY/30/26
NEAR TERM...30
SHORT TERM...26
LONG TERM...RPY
AVIATION...30
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
149 PM EST SAT DEC 6 2014
.SYNOPSIS...
LOW PRESSURE WAVE PASSES WITH COLDER AIR IN ITS WAKE TONIGHT.
HIGH PRESSURE SUNDAY. LOW PRESSURE ALONG MID ATLANTIC COAST MONDAY
NIGHT. COLD FRONT TUESDAY WITH COLDER AIR TUESDAY NIGHT INTO WEDNESDAY.
&&
.NEAR TERM /THROUGH SUNDAY/...
AS OF 18Z THE FRONT HAS CLEARED CRW AND CKB WITH SURFACE LOW E OF
EKN. FRONT WILL CLEAR THE MOUNTAINS BY 21Z. AS THE FRONT
CROSSES...TEMPERATURE FALLS OF 7 TO 10 DEGREES CAN BE EXPECTED
WITH GRADUALLY LOWERING TEMPS THEREAFTER THROUGH THE EVENING. LOW
CIGS AND VSBY IN POST FRONTAL DZ CAN BE EXPECTED THRU THE
REMAINDER OF THE AFTERNOON...ALONG WITH GUSTY NW WINDS. WILL WATCH
-RA TO FILL BACK IN LATER THIS AFTERNOON AS THE UPPER LEVEL TROF
CROSSES. AREA WILL BEGIN TO DRY OUT WITH PASSAGE OF THE UPPER
LEVEL TROF...SAVE FOR SOME DZ HANGING ON ACROSS THE MOUNTAINS THIS
EVENING. ELECTED TO KEEP POSSIBILITY OF IT ENDING AS A LITTLE FRZ
DZ BUT NOT EXPECTING ANY IMPACTS.
WHAT WILL NOT CLEAR OUT THIS EVENING IS THE LOW STRATUS.
HOWEVER...DO EXPECT BASES TO LIFT A BIT TONIGHT. THINK SE OH WILL
SCT OUT DURING THE PREDAWN. HOWEVER...DEVELOPING SUBSIDENCE
INVERSION BENEATH THIS LINGERING MOISTURE WILL MAKE IT VERY
DIFFICULT FOR STRATUS TO BREAK UP E OF THE OH RIVER OVERNIGHT. WITH WEAK
CAA BENEATH THE INVERSION AND LOW LEVEL WINDS BECOMING MORE
NE...FELT IT NECESSARY TO HOLD THE STRATUS IN ALONG THE
CLIMATOLOGICAL FAVORED AREAS IN THIS SETUP....IE THE C LOWLANDS
AND COAL FIELDS THRU THE MORNING HOURS. CLOUDS WILL GRADUALLY SCT
OUT FROM NE TO SW...WITH AREAS ALONG AND S OF I64 CORRIDOR THE
LAST TO LOSE THE STRATUS...POSSIBLY HOLDING ON UNTIL LATE
AFTERNOON.
FOR TEMPS...USED A BLEND OF LAMP AND HRRR FOR TEMPS TONIGHT. FOR
SUNDAY...USED MET AS A BASE WHICH BETTER REFLECTED EXPECTED COOLER
READINGS ALONG AND ESPECIALLY S OF I64 CORRIDOR DUE TO CLOUDS.
FURTHER N...FELT LOCAL MOS WAS THE WAY TO GO WHERE READINGS SHOULD
REACH INTO THE MID OR UPPER 40S.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
STILL A TOUGH CLOUD AND TEMPERATURE FORECAST FOR SUNDAY...WITH LOW
LEVEL MOISTURE MOSTLY AOB 925 MB SUNDAY MORNING. WILL HOLD ONTO
THOSE CLOUDS A BIT LONGER IN SOUTHERN COAL FIELDS OF WV.
SURFACE HIGH PRESSURE QUICKLY PASSES OUR LONGITUDE SUNDAY AFTERNOON
WITH LOW LEVEL FLOW VEERING TO EAST AND SOUTHEAST SUNDAY NIGHT.
ANOTHER TOUGH TEMPERATURE FORECAST WITH 925 MB FLOW BLOWING AT 15 TO
25 KNOTS. SOME HIGH CLOUDS MAY ALSO BE AROUND SUNDAY NIGHT. WILL
TRY TO DROP TEMPERATURES A BIT LOWER...BUT NOT AS LOW AS NAM AND GFS
MOS GUIDANCE.
THE SURFACE WAVE ALONG THE MID ATLANTIC COAST...TRYING TO GET
ORGANIZED MONDAY INTO MONDAY NIGHT...MAY BRUSH OUR EASTERN MOUNTAIN
COUNTIES WITH DEEPER MOISTURE...BUT CURRENTLY WILL ONLY HAVE CHANCE
POPS THERE....BEFORE THAT DEEPER MOISTURE GETS SHUNTED EAST. THE
EASTERN LOW LEVEL FLOW SHOULD KEEP THOSE UPSLOPE AREAS A BIT COOLER
FOR MONDAY MAXIMUM TEMPERATURE. THE WESTERN
THE DIGGING UPPER/MID LEVEL TROUGH FROM THE UPPER MIDWEST STARTS
AFFECTING US TUESDAY WITH COLDER AIR BECOMING ESTABLISHED BY TUESDAY
NIGHT. INCREASED POPS FOR SNOW SHOWERS...ESPECIALLY FOR TUESDAY
NIGHT.
OVERALL...NO MAJOR STORMS FORESEEN...BUT A COLDER PATTERN
BY TUESDAY INTO WEDNESDAY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
USED A BLEND OF THE GFS...GEFS MEAN...ECMWF...ECMWF MEAN...AND
CONTINUITY WITH THE PREVIOUS FORECAST. THIS WOULD HAVE WRAP AROUND
MOISTURE OVER THE REGION FOR TUESDAY NIGHT INTO WEDNESDAY. 850 MB
TEMPERATURES ARE MARGINAL FOR UPSLOPE SNOW...SO COULD SEE DRIZZLE
INSTEAD OF SNOW IN MANY AREAS. A HIGH PRESSURE SYSTEM THEN MOVES IN
FOR THE END OF THE WORK WEEK AND INTO THE WEEKEND...ALLOWING
TEMPERATURES TO MODERATE SOME.
&&
.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
SURFACE FRONT WAS E OF CRW/CKB AS OF 18Z. EXPECT IT TO CROSS KEKN
AND KBKW BY 20Z. CIGS AND VSBY WILL LOWER INTO IFR OR WORSE FOR A
TIME IN POST FRONTAL DZ ACROSS MUCH OF THE AREA. WINDS WILL ALSO
GUST IN THE 15 TO 20 KT RANGE...A BIT HIGHER WITH ACTUAL FROPA.
ANOTHER ROUND OF SHRA POSSIBLE LATER THIS AFTERNOON AND INTO THE
EARLY EVENING HRS WITH THE PASSAGE OF THE UPPER LEVEL TROF.
ALLOWED TO VSBY TO IMPROVE INTO MVFR AND EVENTUAL VFR OVERNIGHT AS
DRIER AIR ADVECTS IN NEAR THE SURFACE. ALSO ALLOWED CIGS TO LIFT A
BIT INTO MVFR...FOLLOWING PASSAGE OF THE UPPER TROF. STILL HAVE
CIGS BELOW 2 GRAND MARK THOUGH.
THE LOW STRATUS SHOULD SCT OUT ACROSS SE OH OVERNIGHT...BUT WILL
HANG TOUGH E OF THE OH RIVER TO AFFECT THE TAF SITES. THE LOW
LEVEL FLOW WILL BECOME MORE NE OVERNIGHT WITH SOME GUSTS
CONTINUING. THIS COMBINED WITH DEVELOPING SUBSIDENCE INVERSION
WILL KEEP THE LOW STRATUS IN PLACE FIRST HALF OF SUNDAY...WITH
KCRW AND KHTS PERHAPS NOT SCT OUT UNTIL AFTER END OF TAF PERIOD.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z SUNDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING AND EXTENT OF IFR CONDITIONS MAY VARY.
TIMING ERADICATION OF LOW STRATUS MAY VARY...POSSIBLY OCCURRING
MUCH SOONER THAN CURRENTLY FORECAST.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EST 1HRLY 13 14 15 16 17 18 19 20 21 22 23 00
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY M M H H H H H H H H H H
BKW CONSISTENCY H H H H H M M L L L L H
EKN CONSISTENCY H H H L L L L L L L L L
PKB CONSISTENCY H M H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 18Z SUNDAY...
IFR POSSIBLE IN RAIN/SNOW MONDAY NIGHT INTO WEDNESDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...RPY/30/26
NEAR TERM...30
SHORT TERM...KTB
LONG TERM...RPY
AVIATION...30
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
147 PM EST SAT DEC 6 2014
.SYNOPSIS...
LOW PRESSURE WAVE PASSES WITH COLDER AIR IN ITS WAKE TONIGHT.
HIGH PRESSURE SUNDAY. LOW PRESSURE ALONG MID ATLANTIC COAST MONDAY
NIGHT. COLD FRONT TUESDAY WITH COLDER AIR TUESDAY NIGHT.
&&
.NEAR TERM /THROUGH SUNDAY/...
AS OF 18Z THE FRONT HAS CLEARED CRW AND CKB WITH SURFACE LOW E OF
EKN. FRONT WILL CLEAR THE MOUNTAINS BY 21Z. AS THE FRONT
CROSSES...TEMPERATURE FALLS OF 7 TO 10 DEGREES CAN BE EXPECTED
WITH GRADUALLY LOWERING TEMPS THEREAFTER THROUGH THE EVENING. LOW
CIGS AND VSBY IN POST FRONTAL DZ CAN BE EXPECTED THRU THE
REMAINDER OF THE AFTERNOON...ALONG WITH GUSTY NW WINDS. WILL WATCH
-RA TO FILL BACK IN LATER THIS AFTERNOON AS THE UPPER LEVEL TROF
CROSSES. AREA WILL BEGIN TO DRY OUT WITH PASSAGE OF THE UPPER
LEVEL TROF...SAVE FOR SOME DZ HANGING ON ACROSS THE MOUNTAINS THIS
EVENING. ELECTED TO KEEP POSSIBILITY OF IT ENDING AS A LITTLE FRZ
DZ BUT NOT EXPECTING ANY IMPACTS.
WHAT WILL NOT CLEAR OUT THIS EVENING IS THE LOW STRATUS.
HOWEVER...DO EXPECT BASES TO LIFT A BIT TONIGHT. THINK SE OH WILL
SCT OUT DURING THE PREDAWN. HOWEVER...DEVELOPING SUBSIDENCE
INVERSION BENEATH THIS LINGERING MOISTURE WILL MAKE IT VERY
DIFFICULT FOR STRATUS TO BREAK UP E OF THE OH RIVER OVERNIGHT. WITH WEAK
CAA BENEATH THE INVERSION AND LOW LEVEL WINDS BECOMING MORE
NE...FELT IT NECESSARY TO HOLD THE STRATUS IN ALONG THE
CLIMATOLOGICAL FAVORED AREAS IN THIS SETUP....IE THE C LOWLANDS
AND COAL FIELDS THRU THE MORNING HOURS. CLOUDS WILL GRADUALLY SCT
OUT FROM NE TO SW...WITH AREAS ALONG AND S OF I64 CORRIDOR THE
LAST TO LOSE THE STRATUS...POSSIBLY HOLDING ON UNTIL LATE
AFTERNOON.
FOR TEMPS...USED A BLEND OF LAMP AND HRRR FOR TEMPS TONIGHT. FOR
SUNDAY...USED MET AS A BASE WHICH BETTER REFLECTED EXPECTED COOLER
READINGS ALONG AND ESPECIALLY S OF I64 CORRIDOR DUE TO CLOUDS.
FURTHER N...FELT LOCAL MOS WAS THE WAY TO GO WHERE READINGS SHOULD
REACH INTO THE MID OR UPPER 40S.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
STILL A TOUGH CLOUD AND TEMPERATURE FORECAST FOR SUNDAY...WITH LOW
LEVEL MOISTURE MOSTLY AOB 925 MB SUNDAY MORNING. WILL HOLD ONTO
THOSE CLOUDS A BIT LONGER IN SOUTHERN COAL FIELDS OF WV.
SURFACE HIGH PRESSURE QUICKLY PASSES OUR LONGITUDE SUNDAY AFTERNOON
WITH LOW LEVEL FLOW VEERING TO EAST AND SOUTHEAST SUNDAY NIGHT.
ANOTHER TOUGH TEMPERATURE FORECAST WITH 925 MB FLOW BLOWING AT 15 TO
25 KNOTS. SOME HIGH CLOUDS MAY ALSO BE AROUND SUNDAY NIGHT. WILL
TRY TO DROP TEMPERATURES A BIT LOWER...BUT NOT AS LOW AS NAM AND GFS
MOS GUIDANCE.
THE SURFACE WAVE ALONG THE MID ATLANTIC COAST...TRYING TO GET
ORGANIZED MONDAY INTO MONDAY NIGHT...MAY BRUSH OUR EASTERN MOUNTAIN
COUNTIES WITH DEEPER MOISTURE...BUT CURRENTLY WILL ONLY HAVE CHANCE
POPS THERE....BEFORE THAT DEEPER MOISTURE GETS SHUNTED EAST. THE
EASTERN LOW LEVEL FLOW SHOULD KEEP THOSE UPSLOPE AREAS A BIT COOLER
FOR MONDAY MAXIMUM TEMPERATURE. THE WESTERN
THE DIGGING UPPER/MID LEVEL TROUGH FROM THE UPPER MIDWEST STARTS
AFFECTING US TUESDAY WITH COLDER AIR BECOMING ESTABLISHED BY TUESDAY
NIGHT. INCREASED POPS FOR SNOW SHOWERS...ESPECIALLY FOR TUESDAY
NIGHT.
OVERALL...NO MAJOR STORMS FORESEEN...BUT A COLDER PATTERN
BY TUESDAY INTO WEDNESDAY.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
MODELS INDICATE A HIGH PRESSURE MOVING OVER NEW ENGLAND...EXTENDING
SOUTHWEST INTO WV SUNDAY NIGHT. ALTHOUGH A COLD AIR MASS WILL BE IN
PLACE...THIS PATTERN WOULD BRING EAST TO SOUTHEAST FLOW...CAPABLE TO
PRODUCE DOWNSLOPING WARMING ACROSS THE LOWLANDS SUNDAY NIGHT.
INCREASED FEW DEGREES FROM HPC GUIDANCE ACCORDINGLY.
FOR MONDAY...BUFKIT SOUNDINGS SHOW DRY AIR ALOFT WITH LIMITED
MOISTURE IN THE VERY LOW LEVELS WHILE A H500 WEAK SHORTWAVE CROSSES
THE AREA. KEPT LOW CHANCE POPS WITH THIS FEATURE...MORE ALONG THE
GFS SOLUTION. THE ECMWF BRINGS STRONG COLD AIR ADVECTION FOR THE
SAME TIME PERIOD WITH SUCH A WEAK WAVE. BELIEVE ECMWF IS OVERDOING
CAA SO PREFERRED THE GFS.
BY MONDAY NIGHT FLOW IN THE LOW LEVELS TURN NORTHWEST WITH SOME CAA
FROM BOTH MODELS. FIGURE A GOOD SET UP FOR UPSLOPE PCPN. THE GFS
BRINGS THE 0C LEVEL AROUND THE NORTHEAST MOUNTAINS WHILE IN THE
ECMWF...THE 0C LINE GOES WAY SOUTH OF THE AREA. WENT WITH A BLEND
SOLUTION EXPECTING CHANCE POPS WITH FEW SNOW SHOWERS OR MIX PCPN
OVER THE MOST FAVORABLE UPSLOPE AREAS...AND RAIN ELSEWHERE. PCPN IS
EXPECTED TO TAMPER OFF ON TUESDAY KEEPING CHANCE POPS OVER THE
EASTERN MOUNTAINS ESPECIALLY WITH THE UPSLOPE COMPONENT AND DRY
WEATHER SPREADING FROM SOUTHEAST OH...EAST.
DRY WEATHER EXPECTED THROUGH THE REST OF THE PERIOD AS A HIGH
PRESSURE BUILDS IN.
WENT CLOSE TO HPC TEMPERATURES THROUGH THE PERIOD.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
SURFACE FRONT WAS E OF CRW/CKB AS OF 18Z. EXPECT IT TO CROSS KEKN
AND KBKW BY 20Z. CIGS AND VSBY WILL LOWER INTO IFR OR WORSE FOR A
TIME IN POST FRONTAL DZ ACROSS MUCH OF THE AREA. WINDS WILL ALSO
GUST IN THE 15 TO 20 KT RANGE...A BIT HIGHER WITH ACTUAL FROPA.
ANOTHER ROUND OF SHRA POSSIBLE LATER THIS AFTERNOON AND INTO THE
EARLY EVENING HRS WITH THE PASSAGE OF THE UPPER LEVEL TROF.
ALLOWED TO VSBY TO IMPROVE INTO MVFR AND EVENTUAL VFR OVERNIGHT AS
DRIER AIR ADVECTS IN NEAR THE SURFACE. ALSO ALLOWED CIGS TO LIFT A
BIT INTO MVFR...FOLLOWING PASSAGE OF THE UPPER TROF. STILL HAVE
CIGS BELOW 2 GRAND MARK THOUGH.
THE LOW STRATUS SHOULD SCT OUT ACROSS SE OH OVERNIGHT...BUT WILL
HANG TOUGH E OF THE OH RIVER TO AFFECT THE TAF SITES. THE LOW
LEVEL FLOW WILL BECOME MORE NE OVERNIGHT WITH SOME GUSTS
CONTINUING. THIS COMBINED WITH DEVELOPING SUBSIDENCE INVERSION
WILL KEEP THE LOW STRATUS IN PLACE FIRST HALF OF SUNDAY...WITH
KCRW AND KHTS PERHAPS NOT SCT OUT UNTIL AFTER END OF TAF PERIOD.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z SUNDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING AND EXTENT OF IFR CONDITIONS MAY VARY.
TIMING ERADICATION OF LOW STRATUS MAY VARY...POSSIBLY OCCURRING
MUCH SOONER THAN CURRENTLY FORECAST.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EST 1HRLY 13 14 15 16 17 18 19 20 21 22 23 00
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY M M H H H H H H H H H H
BKW CONSISTENCY H H H H H M M L L L L H
EKN CONSISTENCY H H H L L L L L L L L L
PKB CONSISTENCY H M H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 18Z SUNDAY...
IFR POSSIBLE IN RAIN/SNOW MONDAY NIGHT INTO TUESDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...RPY/30/26
NEAR TERM...30
SHORT TERM...KTB
LONG TERM...ARJ
AVIATION...30
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
304 PM CST SAT DEC 6 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 301 PM CST SAT DEC 6 2014
COMPLEX FORECAST OVER THE NEXT DAY AS AN UPPER WAVE MOVES ACROSS THE
AREA...ACCOMPANIED BY A LOW PRESSURE MOVING ACROSS THE CANADIAN
BORDER DRAGGING A COLD FRONT THROUGH THE REGION. AS OF THIS
AFTERNOON...LOW STRATUS HAS ERODED AND PUSHED OFF TO THE SOUTH OF
THE CWA. HOWEVER AS LOW LEVEL WINDS TURN MORE SOUTHEASTERLY AND
SOUTHERLY AHEAD OF THE APPROACHING FRONT...EXPECT THIS STRATUS TO
BEGIN STREAMING BACK INTO THE REGION. THE RAP SEEMS TO HAVE THE BEST
HANDLE ON THIS...AND THINK THIS LOW STRATUS SHOULD APPROACH SIOUX
CITY AROUND MIDNIGHT...PUSHING NORTH INTO THE EARLY MORNING
HOURS...LIKELY MAKING IT EVERYWHERE ALONG AND EAST OF THE JAMES
RIVER.
NEXT QUESTION IS FOG POTENTIAL. ONE THING GOING AGAINST WIDESPREAD
DENSE FOG IS THE STRONG SOUTHERLY BREEZE...WHICH WILL LIKELY BE
AVERAGING 15 TO 25 MPH...GUSTING 25 TO 35 MPH. PROBABLY EVEN A BIT
HIGHER ALONG THE BUFFALO RIDGE. HOWEVER MOISTURE IS SHALLOW AND NEAR
THE GROUND...SO STRATUS COULD COME IN LOW ENOUGH TO RESULT IN DENSE
FOG EVEN GIVEN THE WIND...WHICH THE RAP SUGGESTS. GIVEN THE
UNCERTAINTY WILL JUST INCLUDE PATCHY FOG IN THE GRIDS FOR NOW...AND
THE EVENING AND OVERNIGHT SHIFT WILL HAVE TO MONITOR TRENDS AND
ADJUST AS NEEDED.
THE NEXT QUESTION IS PRECIPITATION POTENTIAL. TWO ASPECTS TO
THIS...DRIZZLE WITH THE LOW LEVEL MOISTURE...AND RAIN WITH THE UPPER
LEVEL FEATURE AND FRONTOGENESIS. WITH REGARDS TO THE DRIZZLE
POTENTIAL...MOISTURE IS ORIGINALLY PRETTY SHALLOW WHICH WOULD SEEM
TO MAKE DRIZZLE UNLIKELY. BY LATER TONIGHT INTO TOMORROW MORNING
MOISTURE DEPTH BEGINS TO INCREASE...AS DOES LIFT IN THE MOISTURE
LAYER. THIS WOULD SEEM TO SUGGEST AN INCREASE IN THE DRIZZLE
POTENTIAL BY MID MORNING EAST OF THE JAMES RIVER. THE PASSAGE OF THE
FRONT WILL EVENTUALLY END THAT THREAT FROM WEST TO EAST THROUGH THE
AFTERNOON. THE UPPER LEVEL WAVE AND MID LEVEL FRONTOGENESIS WILL TRY
TO PRODUCE SOME LIGHT PRECIPITATION AS WELL FROM EARLY SUNDAY INTO
THE AFTERNOON. QUITE A BIT OF MID LEVEL DRY AIR FOR THIS
PRECIPITATION TO OVERCOME THOUGH...AND MOST MODELS ARE TRENDING
DRIER. SO DID CUT BACK QPF...WITH BEST CHANCE OF MEASURABLE
PRECIPITATION ALONG AND EAST OF INTERSTATE 29...WITH CHANCES
INCREASING AS YOU GO EAST.
LAST QUESTION IS PRECIPITATION TYPE. WITH QUITE A STRONG WARM NOSE
ALOFT...THINK ANYTHING WILL EITHER BE LIGHT RAIN OR FREEZING RAIN.
COULD SEE A BIT OF SLEET MIXED IN...BUT NOT EXPECTING IT TO BE A
PREDOMINANT TYPE. THUS PTYPE WILL PROBABLY COME DOWN TO SURFACE
TEMPERATURES. USED A BLEND OF RAW GUIDANCE...WEIGHTED TOWARDS THE
GEM...ECMWF AND WRF ARW FOR HOURLY TEMPERATURES TONIGHT INTO
TOMORROW. THIS WARMS SIOUX CITY ABOVE FREEZING BY 14Z...SIOUX FALLS
BY 16Z AND THE REMAINDER OF THE CWA BY 18Z. THUS I DO THINK A PERIOD
OF FREEZING DRIZZLE OR LIGHT FREEZING RAIN IS POSSIBLE. ALTHOUGH BY
THE TIME THE DRIZZLE INCREASES...WE COULD VERY WELL BE ABOVE
FREEZING...LIMITING THE FREEZING POTENTIAL. THE BEST CHANCE OF A
LIGHT COATING OF ICE SEEMS TO BE EAST OF INTERSTATE 29 WHERE COLD
AIR HOLDS ON A BIT LONGER. GIVEN THE UNCERTAINTY WILL HOLD OFF ON
ANY ADVISORY. BUT THOSE WITH MORNING TRAVEL PLANS SHOULD KEEP ALERT
OF THE FORECAST...AS EVEN JUST A LIGHT COATING OF ICE CAN CAUSE
IMPACTS. EVENING AND OVERNIGHT SHIFT WILL HAVE TO MONITOR
TRENDS...AND ISSUE ANY ADVISORY IF CONFIDENCE IN MORE WIDESPREAD
FREEZING DRIZZLE OR LIGHT FREEZING RAIN INCREASES.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 301 PM CST SAT DEC 6 2014
THE MAIN FOCUS IN THE MEDIUM AND EXTENDED FOCUSES ON TEMPERATURES.
WHILE MAJORITY OF PRECIPITATION WILL TAKE PLACE DURING THE DAY ON
SUNDAY...WILL HAVE TO WATCH FOR LOW STRATUS ROTATING BACK INTO THE
AREA BEHIND DEPARTING UPPER TROUGH SUNDAY NIGHT. SOUNDINGS SUGGEST
A VERY LIGHT PRECIPITATION POTENTIAL...IN THE FORM OF
FLURRIES/SPRINKLES/DRIZZLE.
COLDER AIR WILL NOT QUITE MAKE IT SOUTHWARD ON MONDAY...BUT THE
WESTERLY WIND AND LINGERING WARM AIR ALOFT WILL STILL ALLOW FOR
ABOVE NORMAL TEMPERATURES. A MORE DIRECT COOLDOWN WILL ARRIVE ON
TUESDAY AS SURFACE HIGH PRESSURE MOVES OVERHEAD. THE MISSOURI RIVER
VALLEY MAY STILL REACH THE MID 30S...BUT AREAS FURTHER NORTHEAST
COULD STRUGGLE TO CLIMB ABOVE FREEZING.
LOW LVL WARM ADVECTION BEGINS LATE TUESDAY AS MID-LVL HEIGHTS RISE
OVER THE CENTRAL CONUS. GFS/ECMWF CONSISTENT NOW IN BRINGING A
WEAK SHORTWAVE THROUGH THE AREA TUESDAY NIGHT AND WEDNESDAY...BUT
LITTLE IMPACT IS ANTICIPATED OTHER THAN CLOUD COVER.
THEN BEGINS A STRETCH OF ABOVE NORMAL TEMPERATURES...SOME THAT COULD
RIVAL SOME OF OUR WARMER TEMPERATURES RECORDED IN DECEMBER.
MODELS STILL DIFFERING TO SOME DEGREE ON MOISTURE RETURN AND
IMPACT ON STRATUS ACROSS THE REGION. ALOFT...TEMPERATURES ARE
SURELY IMPRESSIVE WITH 925MB TEMPERATURES BY SATURDAY APPROACHING
+10C...AND 850MB TEMPERATURES AROUND +15C...SOME OF THE WARMEST
READINGS RECORDED VIA SOUNDINGS IN DECEMBER AT ABERDEEN. MODEL
PREFERENCE CONTINUES TO FALL WITH THE ECMWF...WHICH DOES SHOW
STRATUS ADVECTING INTO THE AREA BY THURSDAY...BUT IS NOT NEARLY AS
AGGRESSIVE AS THE TYPICALLY OVERSATURATED GFS AND SUGGESTED A
SLIGHTLY MORE VEERED LOW LVL FLOW. THAT SAID...FOR TEMPERATURES
WED- SAT UTILIZED A BLEND OF WPC AND ECMWF...WHICH FALL ON THE
WARMEST SIDE OF GUIDANCE AND STILL MAY NOT BE WARM ENOUGH FOR
SATURDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1132 AM CST SAT DEC 6 2014
COMPLEX FORECAST OVER THE NEXT 24 HOURS. STRATUS NEAR KSUX
CONTINUES TO DISSIPATE AND MOVE OFF TO THE SOUTHWEST...AND EXPECT
THEM TO BE VFR BY 19 OR 20Z. HOWEVER...AS THE SOUTHERLY LOW LEVEL
JET INCREASES TONIGHT...EXPECT THIS STRATUS TO RETURN TO THE
AREA. TIMED THIS USING A MODEL CONSENSUS...WEIGHTED TOWARDS THE
RAP WHICH CURRENTLY HAS THE BEST HANDLE OF THINGS. UNCERTAINTY ON
HOW LOW THE CIGS GET...SO KEPT IFR FOR NOW...BUT WOULD NOT BE
SURPRISED TO SEE AREAS OF LIFR. ALSO THE SOUTHERLY BREEZE MAY KEEP
DENSE FOG FROM FORMING...ALTHOUGH STRATUS MAY COME IN LOW ENOUGH
THAT WE DO INDEED GET DENSE FOG. SO IN SUMMARY...CONFIDENCE ON AT
LEAST MVFR TO IFR CIGS IS HIGH TONIGHT INTO TOMORROW
MORNING...CONFIDENCE ON TIMING IS MODERATE...WITH LOW CONFIDENCE
ON EXACT CIG HEIGHT AND VISIBILITY.
OTHER CONCERN IS DRIZZLE OR FREEZING FRIZZLE. THIS IS CERTAINLY A
POSSIBILITY WITH THE STRATUS...ALTHOUGH WOULD LIKE TO SEE A
DEEPER LAYER OF SATURATION. THUS CONFIDENCE REMAINS LOW ON THIS
AND WILL KEEP OUT OF THE TAFS FOR NOW. ALSO MAY SEE A PERIOD OF
LIGHT RAIN OR FREEZING RAIN AS THE FRONT AND WAVE PASS ACROSS
TOMORROW MORNING. BUT BEST CHANCE OF THIS IS EAST OF INTERSTATE
29...SO WILL KEEP THE TAFS DRY. BUT WITH THE LIGHT FREEZING RAIN
OR DRIZZLE POTENTIAL...WILL NEED TO MONITOR TRENDS.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...CHENARD
LONG TERM...DUX
AVIATION...CHENARD
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1119 PM CST FRI DEC 5 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 304 PM CST FRI DEC 5 2014
ALTHOUGH VISIBILITY HAS IMPROVED...FOG CONTINUES TO RESIDE THROUGH
NORTHWEST IOWA THIS AFTERNOON...SO THE BIGGEST CHALLENGE TONIGHT
REMAINS HOW QUICKLY FOG ERODES AS DRIER AIR FILTERS IN BEHIND THE
SURFACE TROUGH PUSHING ACROSS THE REGION. WATCHING THE TRENDS
THROUGH THE AFTERNOON...VISIBILITIES HAVE QUICKLY IMPROVED AS THE
WINDS TRANSITIONED TO NORTHERLY BEHIND THE TROUGH AND THE DRIER AIR
DRAINED IN. USING THAT AND RAP 925 MB RH FIELDS WHICH HAVE ALSO
CORRELATED WELL WITH THE FOG...HAVE THE FOG LINGERING THROUGH
PORTIONS OF NORTHWEST IOWA THROUGH THE EVENING THEN SLOWLY ERODING
FROM THE NORTH AND WEST AS DRIER AIR TAKES OVER DURING THE NIGHT.
COLDER AIR WILL ALSO FILTER SOUTH OVERNIGHT...WITH LOWS BOTTOMING
OUT AROUND 10 THROUGH THE HIGHWAY 14 CORRIDOR TO THE UPPER TEENS
THROUGH THE MISSOURI RIVER VALLEY.
SURFACE HIGH PRESSURE SETTLES INTO THE REGION ON SATURDAY...SO
SHOULD SEE SOME SUN ALONG WITH RELATIVELY LIGHT WINDS DURING THE DAY
WITH A WEAK GRADIENT EXISTING ACROSS THE REGION. WITH THERMAL
PROFILES A LITTLE COOLER HIGHS WILL RANGE FROM THE LOWER 30S NORTH
TO UPPER 30S SOUTH.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 304 PM CST FRI DEC 5 2014
THE PRIMARY FORECAST CONCERNS IN THE MEDIUM AND SHORT RANGE CONTINUE
TO FOCUS ON LIGHT PRECIPITATION CHANCES SUNDAY AND WARMUP INTO
NEXT WEEK/WEEKEND.
SUNDAY...MODELS STILL ON TRACK BRINGING TWO PIECES OF SHORTWAVE
ENERGY INTO THE REGION LATE SATURDAY NIGHT AND INTO SUNDAY. THE
FIRST WAVE WILL LIFT NORTHWARD FROM THE SOUTHWESTERN US WITH THE
SECOND WAVE DIPPING SOUTHEAST FROM THE PACIFIC NORTHWEST.
AGAIN...MOISTURE REMAINS RATHER SHALLOW IN NATURE AS THESE WAVES
MOVE THROUGH BUT AM ANTICIPATING A NARROW CORRIDOR OF LIGHT FREEZING
RAIN/DRIZZLE DEVELOPING NEAR DAYBREAK ALONG AND WEST OF I-29. WHILE
THE ATMOSPHERIC PROFILE LACKS ICE CRYSTALS FOR MOST OF THE
EVENT...THERE COULD BE A BRIEF WINDOW OF SATURATION EARLY IN THE
AFTERNOON WHICH WOULD OWE TO SLEET INTRODUCTION ESPECIALLY IN THE NE
ZONES. THE PRECIPITATION SHOULD BE LIGHT ENOUGH TO AVOID ANY
MAJOR ICING CONCERNS...ESPECIALLY SINCE SFC TEMPERATURES WILL
CONTINUE TO RISE THROUGH THE MORNING AND SHOULD CLIMB ABOVE
FREEZING IN THE AFTERNOON.
NEXT WEEK...SLIGHT MODEL DIFFERENCES CONTINUE FOR MUCH OF NEXT WEEK
WITH BOTH MAJOR EXTENDED RANGE MODELS SHOWING INCREASED RIDGING
ACROSS THE CONUS INTO NEXT WEEKEND. TEMPERATURES WILL COOL SLIGHTLY
BEHIND SUNDAYS DEPARTING TROUGH...BUT STILL AVERAGE NEAR OR SLIGHTLY
ABOVE SEASONAL NORMALS. FAIRLY SUBSTANTIAL DIFFERENCES PERSIST IN
THE HANDLING OF SHORTWAVE ENERGY MOVING THROUGH THE PACIFIC
NORTHWEST ON MONDAY. ECMWF KEEPS THIS ENERGY WELL NORTH OF THE
CWA...MEANWHILE THE GFS PULLS THE WAVE THROUGH THE CENTRAL PLAINS.
THE END RESULTS COULD BE SUBSTANTIAL DIFFERENT FOR WEDNESDAY-
FRIDAY. SHOULD THE GFS SOLUTION VERIFY...THE RESULT WOULD BE
INCREASED CLOUD COVER...FOG...AND SLIGHTLY COOLER TEMPS IN THE
LOCAL AREA. ON THE FLIPSIDE...THE MORE AMPLIFIED ECMWF SOLN COULD
SUGGEST VERY WARM TEMPERATURES THURSDAY AND INTO THE WEEKEND. FOR
TODAY...PREFERENCES CONTINUE TO FALL TOWARDS THE ECMWF...BUT WILL
HEDGE A BIT TOWARDS THE OTHER CAMP OF SOLNS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1119 PM CST FRI DEC 5 2014
MONITORING A QUICK END ON KSUX AREA WEBCAMS TO THE VLIFR AND IFR
CONDITIONS AROUND KSUX WHICH ARE EXPECTED TO BE OUT OF THE KSUX
AREA BY ISSUANCE OF THE 06Z TAFS. MOISTURE WILL KEEP THREAT OF
SOME MVFR VISIBILITIES AROUND THE KSUX AREA INTO EARLY MORNING
AS NORTHERLY WINDS DIMINISH. FOR KFSD...MORE LIKELY TO GET ONLY
A PERIOD OF SHALLOW VALLEY FOG...WITH DEEPER DRY LAYER ALOFT.
TOWARD THE END OF THE TAF PERIOD...MAY SEE RESURGENCE IN THE LIFR
CEILINGS AS FLOW TURNS TO THE SOUTHEAST.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...JM
LONG TERM...DUX
AVIATION...CHAPMAN
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1011 PM MST FRI DEC 5 2014
.UPDATE...
ISSUED AT 725 PM MST FRI DEC 5 2014
STALLED LL BAROCLINIC ZONE ACROSS THE FAR NORTH WILL INTERACT
WITH A PASSING MID LEVEL IMPULSE THIS EVENING...POSSIBLY
SUPPORTING A FEW LIGHT SHOWERS ACROSS FAR NW SD. HAVE ADDED A
SLIGHT CHANCE FOR PRECIP THERE...OPTING FOR A WINTRY MIX GIVEN
WARM WEDGE ALOFT. OTHERWISE...SUFFICIENT LL MOISTURE AT THE SFC
MAY SUPPORT PATCHY AREAS OF FOG LATER TONIGHT ACROSS WESTERN SD.
HOWEVER...ENSUING SFC PRESSURE FALLS PER LEE SIDE TROUGHING WILL
SUPPORTING INCREASING LL FLOW...INCREASING TURBULENT MIX DOWN OF
DRY AIR. THIS WILL LIKELY LIMIT COVERAGE OF ANY FOG...ESP AWAY
FROM VALLEYS. HAVE TRIMMED DOWN FOG MENTION AND RELEGATED MENTION
TO PATCHY.
&&
.SHORT TERM...THIS EVENING THROUGH SATURDAY NIGHT
ISSUED AT 207 PM MST FRI DEC 5 2014
UPPER LEVEL ANALYSIS SHOWS A RIDGE OVER THE WESTERN
CONUS...WITH NORTHWEST FLOW OVER THE NORTHERN PLAINS. CANADIAN
SURFACE HIGH IS MOVING SOUTHWARD INTO MT/ND. SKIES ARE PARTLY
CLOUDY...WITH GENERALLY LIGHT WINDS AND TEMPS IN THE UPPER 30S AND
40S.
LIGHT WINDS WILL BECOME SOUTHEASTERLY TONIGHT AS THE SURFACE HIGH
CROSSES ND...BRINGING MOISTURE INTO THE AREA. SEVERAL MODELS ARE
STILL HINTING AT SOME FOG SETTING UP AROUND THE AREA. THE HRRR AND
RAP ARE SHOWING LOW CEILINGS ACROSS THE SD PLAINS DEVELOPING AFTER
MIDNIGHT...AND LATEST RUNS ALSO HAVE FOG WRAPPING AROUND THE
SOUTHERN HILLS INTO NORTHEAST WY. MEANWHILE THE NAM HAS THE BEST
CHANCES FOR FOG AROUND THE HILLS AND INTO NORTHEAST WY...NOT SO MUCH
ON THE SD PLAINS. THE NAM SEEMS TO BE OVERESTIMATING MOISTURE
LATELY...AND SINCE WINDS IN NORTHEAST WY LOOK A LITTLE STRONGER
OVERNIGHT...HAVE MORE UNCERTAINTY ABOUT FOG DEVELOPMENT THERE.
DECREASED AREAS OF FOG TO PATCHY ACROSS NORTHEAST WY...KEEPING AREAS
OF FOG JUST EAST OF THE HILLS. COULD ALSO BE SOME PATCHY FOG IN
SURROUNDING AREAS ACROSS THE SD PLAINS. AS THE SURFACE HIGH MOVES
SOUTHEAST OVERNIGHT...COLD AIR WILL ADVECT INTO THE EASTERN CWA.
LOWS WILL RANGE FROM THE TEENS ACROSS NORTH CENTRAL/NORTHWEST SD TO
THE UPPER 20S IN NORTHEAST WY.
SOUTHERLY WINDS WILL BECOME BREEZY BY LATE SATURDAY MORNING AS THE
PRESSURE GRADIENT TIGHTENS BETWEEN THE HIGH PRESSURE TO THE EAST AND
THE INCOMING LOW. EXPECT FOG TO DISSIPATE BY MID-MORNING. THERE IS
SOME UNCERTAINTY WITH TEMPS ON SATURDAY...AS MODELS HAVE A 10-DEGREE
SPREAD FOR HIGHS IN SOME PLACES. WITH SOUTHERLY BOUNDARY-LAYER WINDS
AND WARM AIR ADVECTION...KEPT TEMPS MILD...IN THE MID 30S NORTH AND
EAST TO THE UPPER 40S FARTHER WEST. LOWS SATURDAY NIGHT WILL BE IN
THE 20S TO LOWER 30S.
.LONG TERM...SUNDAY THROUGH FRIDAY
ISSUED AT 207 PM MST FRI DEC 5 2014
MODELS ARE IN GOOD AGREEMENT DURING THE EXTENDED
PERIOD...WITH RELATIVELY HIGH PREDICTABILITY THROUGH AT LEAST
WEDNESDAY. IN THE MEAN...THERE WILL BE A LONG-WAVE TROUGH OFF THE
WEST COAST WITH A LONG-WAVE RIDGE NEAR THE CNTRL CONUS.
ON SUNDAY A SHORT-WAVE TROUGH WILL MOVE ACROSS THE FAR NRN PLAINS
AND THROUGH THE L/W RIDGE...BRINGING A COLD FRONT AND NORTHWEST WIND
SHIFT ACROSS THE CWA. THIS WILL BRING SCT SHRASN TO THE BLKHLS. ON
MONDAY THROUGH WEDNESDAY THE RIDGE REBOUNDS...BUT WITH A WEAK SHORT-
WAVE TROUGH SLOWLY MOVING ACROSS THE NRN PLAINS. THIS IS NOT
EXPECTED TO BRING ANY PRECIP TO THE CWA GIVEN THE LIMITED FORCING
FOR ASCENT AND LACK OF LOW- TO MID-LEVEL MOISTURE.
ON THURSDAY AND FRIDAY...THE LONG-WAVE TROUGH MOVES INTO THE ERN
HALF OF THE CONUS WITH SOUTHWEST FLOW ALOFT DEVELOPING ACROSS THE
CWA IN RESPONSE TO A DEEP UPPER LOW COMING ONSHORE NEAR CA. THE GFS
SEEMS A BIT AGGRESSIVE WITH THIS LOW...SO HAVE KEPT THE FORECAST DRY
THROUGH FRIDAY. NEVERTHELESS...THERE ARE INDICATIONS THAT A BIG
STORM COULD BE LOOMING ON THE HORIZON FOR LATE NEXT WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1010 PM MST FRI DEC 5 2014
VFR CONDITIONS EXPECTED THROUGH THE PERIOD MOST PLACES. INCREASED
BL MOISTURE WITH A PERIOD OF LIGHT WINDS AND CLEAR SKIES MAY
SUPPORT PATCHY/AREAS OF FOG TONIGHT. HOWEVER...INCREASING LL
SOUTHERLY FLOW AND LIMITED MOISTURE ADVECTION SHOULD LIMIT
COVERAGE OF ANY FOG/STRATUS. GIVEN LOW PROBS/CONFIDENCE HAVE
OPTED TO LEAVE OUT OF TERMINALS.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
UPDATE...JC
SHORT TERM...POJORLIE
LONG TERM...BUNKERS
AVIATION...JC
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
630 PM CST SUN DEC 7 2014
.AVIATION...
/00Z TAFS/
Look for challenging flight weather conditions tonight. A line of
showers will continue to slowly drift south tonight. Also, patchy
fog will likely drop the visibility to near the MVFR range at some
terminals. In addition, satellite imagery shows some patchy stratus
still lingering. Thus, watch for MVFR ceilings tonight.
&&
.PREV DISCUSSION... /ISSUED 336 PM CST SUN DEC 7 2014/
SHORT TERM...
(Tonight and Monday)
The primary focus in the short term will be ongoing rain chances
and the return of fog and low visibilities to the forecast area.
Light rain showers will migrate east across the forecast area this
afternoon. Rainfall totals will remain low, though any precip will
assist in keeping the area moist. Inherited PoP grids are adequate
for expected weather this afternoon though new model data is
pessimistic about tonight and early tomorrow morning. Thus, removed
mention of PoPs for that time period.
NAM, GFS, and RAP model soundings are optimistic about bringing fog
back into West Central Texas tonight. At this time, fog is
expected to form sometime after midnight and lift shortly after 9
AM tomorrow. Areas of fog will likely be more widespread tonight
than they were early this morning, extending from south of
Interstate 10 to north of Throckmorton. Light winds tonight and
added moisture from today`s rain showers promote this solution.
Cloud cover kept temperatures from climbing too quickly this
morning resulting in afternoon highs near normal. Tonight, however,
added moisture and low cloud ceilings will insulate the forecast
area and keep temperatures 5-7 degrees above normal. Clearing
skies tomorrow afternoon will allow for unseasonably warm
temperatures with highs mainly in the mid 60s.
18
LONG TERM...
(Monday night through Sunday)
Shortwave ridging aloft Monday night will shift east as we head
into Tuesday as a weak shortwave trough moves across the
Rockies. This feature will move southeast into Plains by Wednesday
morning, slowing as it absorbs southern stream wave over the
southern Plains. Moisture will be slow to increase ahead of this
system, with dewpoints likely remaining in the lower 40s
throughout the day Tuesday. We should see ample high clouds,
keeping temperatures in the mid 60s Tuesday afternoon, but low
clouds are not expected until Tuesday night. This increasing
moisture and cloud cover will limit diurnal ranges and keep min
temps generally in the mid/upper 40s for Wednesday morning.
There are considerable differences in the midweek 500 mb pattern
between the GFS, ECMWF, and GEM, yielding low confidence in any
particular solution at this time. The GFS is the fastest of the
12z runs with the onset of isentropic ascent across West Central
TX with the ECMWF following suit 6-12 hours later. Given what has
been as progressive flow as of late, siding with a bit faster
solution seems reasonable. This broad, isentropic ascent will
result in an abundance of cloud cover Wednesday and Thursday with
a persistent southerly fetch at low-levels, maintaining modest
moisture advection. Rainfall is expected to be rather light,
similar to what we`re seeing today across the area, with amounts
typically under 1/10". The cloud cover and light precipitation
will also keep temps around 60 degrees, with the potential to be a
few degrees cooler if light rain showers are a bit more widespread
than anticipated. Low rain chances will hang around through
Thursday night as weak perturbations move through the flow aloft.
By Friday, we should see improving conditions as the shortwave
trough moves east and shortwave ridging returns. This should allow
a modest warm-up with dry weather anticipated heading into the
weekend. We are watching a rather strong trough setting course for
the west coast late in the week. The medium range models are
moving this trough across the Rockies over the weekend, backing
winds aloft to the southwest. The associated lee cyclogenesis will
enhance low-level winds and should promote increasing surface
moisture. The timing of this feature`s effects for West Central TX
is certainly up in the air at this time, but there is pretty
decent model consensus that a closed mid-level cyclone develops
and moves east-southeast into West TX around Sunday. This pattern
bears watching as it could provide the area with a good
opportunity for measurable rainfall. As usual, there is plenty of
time for things to change, but we`ll be watching!
Johnson
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 40 66 43 66 45 / 5 0 0 0 10
San Angelo 40 66 43 66 45 / 5 0 0 5 20
Junction 41 68 41 66 45 / 10 5 0 0 10
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
Aviation: Huber
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1158 PM CST FRI DEC 5 2014
.AVIATION...
A COLD FRONT HAS MOVED THROUGH NORTH AND CENTRAL TEXAS AS OF
0550Z. NORTH TO NORTHEAST WINDS AROUND 10 KNOTS WILL PREVAIL
THROUGH THE PERIOD. MVFR STRATUS HAS MOVED INTO THE METROPLEX AND
WILL MOVE INTO WACO AROUND 09Z. CEILINGS MAY FALL INTO THE IFR
CATEGORY 10-15Z. THE BROKEN TO OVERCAST CLOUDS ARE EXPECTED TO
BECOME SCATTERED AROUND 18Z SATURDAY. MVFR CEILINGS SHOULD
DEVELOP AGAIN AROUND 06Z SUNDAY.
58
&&
.UPDATE...
COLD FRONT IS ABOUT HALFWAY THROUGH THE CWA THIS EVENING BUT MOST
OF THE SHOWER ACTIVITY HAS DIMINISHED AS UPPER TROUGH PULLS
FARTHER AWAY TO THE EAST. OUTSIDE OF AN ISOLATED SHOWER RIGHT
ALONG THE FRONT...MOST AREAS WILL NOT SEE ANY RAIN. LOWERED POPS
FOR THE REMAINDER OF THE EVENING AND CONFINED THEM TO A NARROW
BAND RIGHT ALONG THE FRONT OVER THE EASTERN COUNTIES.
OTHERWISE...ONLY SOME MINOR DOWNWARD TWEAKS IN LOW TEMPERATURES
WERE NEEDED ACROSS THE NORTH AND NORTHWEST COUNTIES.
DUNN
&&
.PREV DISCUSSION... /ISSUED 339 PM CST FRI DEC 5 2014/
FOR TODAY...THE ONLY SIGNIFICANT CHANGE TO THE FORECAST FROM THE
MORNING UPDATE WAS TO INCREASE POPS SLIGHTLY ALONG AND SOUTHEAST
OF THE FORECAST POSITION OF THE COLD FRONT ACROSS THE CWA THROUGH
TONIGHT. EARLY AFTERNOON RUNS OF THE HRRR CONSISTENTLY ADVERTISE A
SCATTERED LINE OF SHOWERS DEVELOPING ALONG THE LEADING EDGE OF THE
COLD FRONT AS IT MOVES ACROSS THE CWA. AT 20Z/2PM...THE SURFACE
OBSERVATIONS INDICATED THAT THE LEADING EDGE OF THE COLD FRONT WAS
LOCATED ALONG A LINE FROM ARDMORE TO BOWIE TO BRECKENRIDGE. EARLY
AFTERNOON VISIBLE SATELLITE IMAGERY SHOWED A THIN LINE OF CUMULUS
ORGANIZING ALONG THE FRONT...SUPPORTING THE HRRR FORECAST FOR
STRONGER LIFT AND BETTER RAIN SHOWER CHANCES IN THE IMMEDIATE
VICINITY OF THE FRONT.
DESPITE THE INCREASE IN RAIN CHANCES IN THE SHORT TERM
FORECAST...CONTINUE TO THINK CHANCES OF LIGHTNING ARE LOW. 19Z
AIRCRAFT SOUNDINGS FROM KDFW AND KDAL AIRPORTS CONTINUE TO SHOW
MID-LEVEL LAPSE RATES THAT ARE TOO STABLE TO SUPPORT FREE
CONVECTION. LAPSE RATES HAVE INCREASED A BIT FROM 12Z...LIKELY DUE
FROM DYNAMIC LIFT ASSOCIATED WITH A SHORTWAVE TROUGH LOCATED OVER
OKLAHOMA EARLY THIS AFTERNOON ACCORDING TO WATER VAPOR SATELLITE
IMAGERY. HOWEVER DUE TO THE POSITION OF THE SHORTWAVE
TROUGH...THINK THAT THE EFFECTS OF DYNAMIC LIFT ON OUR MID-LEVEL
LAPSE RATES HAVE ALREADY OCCURRED. AS A RESULT...LEFT
PRECIPITATION ALONG THE FRONT THUNDERSTORM FREE THROUGH TONIGHT.
WILL CERTAINLY CONTINUE TO MONITOR AIRCRAFT OBSERVATIONS THROUGH
THIS EVENING...AND WILL UPDATE THE FORECAST IF IT LOOKS LIKE
THUNDER IS BECOMING MORE LIKELY.
SATURDAY...THE COLD FRONT IS EXPECTED TO MOVE ACROSS THE ENTIRE
FORECAST AREA BY SATURDAY MORNING...LEAVING COOLER AND MUCH DRIER
AIR IN PLACE ACROSS THE REGION. ALTHOUGH THE COLD FRONT DOES NOT
REPRESENT A STRONG CANADIAN AIRMASS...AFTER TODAY`S TEMPERATURES
IN THE MID TO UPPER 70S...IT WILL CERTAINLY BE NOTICEABLY COOLER
TOMORROW BEHIND THE FRONT. HIGHS ARE EXPECTED TO TOP OUT NEAR 60
DEGREES FOR MOST LOCATIONS...VERY CLOSE TO NORMAL HIGHS FOR THIS
TIME OF YEAR. BETWEEN LOW-LEVEL DRY AIR ADVECTION BEHIND THE FRONT
AND SHORTWAVE RIDGING ALOFT...MAINTAINED A DRY FORECAST FOR
SATURDAY.
SUNDAY...A RELATIVELY FAST MOVING SHORTWAVE TROUGH...CURRENTLY
LOCATED ABOUT 800 MILES WEST OF BAJA CALIFORNIA...IS EXPECTED TO
MOVE OVER THE SOUTHERN PLAINS SUNDAY AFTERNOON. WITH A LOW-LEVEL
COOL AIRMASS STILL IN PLACE ACROSS THE CWA BEHIND TODAY`S
FRONT...ALL MODEL GUIDANCE INDICATES THAT THIS SHORTWAVE TROUGH
WILL RESULT IN STRONG WARM AIR ADVECTION OVER THE CWA ON SUNDAY.
WARM AIR ADVECTION OVER THE COOL LOW-LEVEL AIRMASS DOES REPRESENT
PERSISTENT LIFT...HOWEVER PRECIPITATION PROSPECTS FOR THE REGION
LOOK VERY LIMITED AT THIS TIME. DESPITE NEARLY ALL MODELS SHOWING
THE PERSISTENT LIFT ON SUNDAY...THE PROSPECTS FOR MOISTURE RETURN
LOOK VERY LIMITED...AND FOCUSED ON LOCATIONS JUST WEST AND SOUTH
OF THE CWA. AS A RESULT...WENT AHEAD AND BUMPED POPS DOWN 10
PERCENT ACROSS THE ENTIRE AREA THROUGHOUT THE DAY ON SUNDAY.
THINK THAT OUR BEST CHANCES FOR LIGHT RAINFALL MAY BE WHEN THE
SHORTWAVE TROUGH MOVES DIRECTLY OVERHEAD SUNDAY AFTERNOON. MODELS
SHOW A BAND OF RELATIVELY STRONG MID-LEVEL FRONTOGENETIC FORCING
MOVING OVER THE CWA RIGHT OUT AHEAD OF THE SHORTWAVE ON SUNDAY.
THIS WILL LIKELY RESULT IN SOME ELEVATED PRECIPITATION...HOWEVER
THE LOW-LEVEL AIRMASS LOOKS DRY ENOUGH THAT MOST OF THIS SHOULD
EVAPORATE BEFORE REACHING THE SURFACE. AT ANY RATE...THE END
RESULT WAS THAT ISOLATED RAIN SHOWERS WERE INCLUDED IN THE
FORECAST EVEN WHERE POPS ARE AS LOW AS 10 PERCENT TO ACCOUNT FOR
THIS VIRGA/LIGHT RAIN POTENTIAL.
MONDAY INTO TUESDAY...IN GENERAL...A REINFORCING SHOT OF COOL AND
DRY AIR WILL BUILD INTO THE AREA BEHIND SUNDAY`S SHORTWAVE TROUGH
KEEPING US DRY ACROSS NORTH TEXAS FOR EARLY NEXT WEEK. THE LARGE
SCALE UPPER AIR PATTERN IS EXPECTED TO BE DOMINATED BY LARGE
TROUGHS OVER THE FAR EAST AND WEST COASTS...RESULTING IN BROAD
RIDGING OR NEARLY ZONAL FLOW OVER THE CENTRAL PORTION OF THE
COUNTRY. THIS PATTERN ALSO GENERALLY FAVORS DRY WEATHER FOR THE
CWA...HOWEVER PERSISTENT WESTERLY FLOW ALOFT OVER THE CONUS
ROCKIES WILL RESULT IN LEE-SIDE TROUGHING INCREASING IN INTENSITY
THROUGHOUT THE WEEK. WITH LEE-SIDE TROUGHING DEVELOPING AND A COOL
AIRMASS IN PLACE...WE WILL ONCE AGAIN HAVE A SITUATION WHERE WE
HAVE SOUTHERLY FLOW ALOFT IMPINGING ON A COOL LOW-LEVEL AIRMASS
NEAR THE SURFACE. THIS WILL RESULT IN PERSISTENT...ALBEIT
WEAK...LIFT AND MOISTURE RETURN BY TUESDAY AFTERNOON. BACKED OFF
ON POPS A BIT FROM THE PREVIOUS FORECAST ON TUESDAY...HOWEVER
MAINTAINED SOME 20 POPS OVER THE FAR WESTERN CWA TUESDAY
AFTERNOON...NEAREST TO THE LOW-LEVEL MOISTURE RETURN CONSISTENTLY
ADVERTISED IN MEDIUM RANGE GUIDANCE.
WEDNESDAY...MODELS ADVERTISE THAT THE UPPER LEVEL PATTERN WILL
AMPLIFY WITH RIDGING BUILDING OVER THE CONUS ROCKIES IN RESPONSE
TO A STRONG UPPER TROUGH BUILDING EASTWARD...FARTHER ON SHORE THE
WESTERN CONUS COAST. THIS RESULTS IN NORTHWEST FLOW ALOFT OVER THE
REGION ON WEDNESDAY...IN WHICH MODELS HAVE BEEN CONSISTENTLY
SENDING A STRONG BUT COMPACT SHORTWAVE TROUGH SOUTHEAST THROUGH
THE CWA OVER THE PAST COUPLE OF DAYS. THIS TROUGH IS EXPECTED TO
REMAIN WELL NORTH OF NORTH TEXAS...BUT SHOULD HELP SPREAD SOME OF
THE MOISTURE RETURN FROM WEST TEXAS EASTWARD OVER THE CWA ON
WEDNESDAY. IF MOISTURE DOES SPREAD EAST AS ADVERTISED AND LOW-
LEVEL WARM AIR ADVECTION AND ISENTROPIC LIFT CONTINUES... LIGHT
RAIN SHOWERS WILL LIKELY SPREAD ACROSS THE ENTIRE CWA ON
WEDNESDAY. BECAUSE LIFT IS EXPECTED TO REMAIN WEAK...RAIN SHOWERS
SHOULD BE SPOTTY/HIT-AND-MISS ON WEDNESDAY.
THURSDAY AND FRIDAY...MODELS INDICATE THAT LOW-LEVEL WARM AIR
ADVECTION PERSISTS...HOWEVER MODELS ARE ALSO BRINGING THE UPPER
LEVEL RIDGE OUT FROM THE CONUS ROCKIES AND OVER THE GREAT PLAINS
FOR THE LATTER PART OF THE WEEK. DESPITE PERSISTENT LOW-LEVEL
LIFT...WILL FAVOR THE UPPER LEVEL RIDGING IN THIS FORECAST AND
KEEP THURSDAY AND FRIDAY DRY FOR NOW AS MID AND UPPER LEVEL
FORCING SHOULD BE DOMINATED BY SUBSIDENCE.
NEXT WEEKEND...MODELS ARE DEFINITELY STRUGGLING WITH RUN TO RUN
AND MODEL TO MODEL CONSISTENCY WITH REGARDS TO THE EVOLUTION OF
THE STRONG WEST COAST UPPER TROUGH. HOWEVER...MODELS HAVE BEEN
CONSISTENTLY BRINGING THIS TROUGH OVER THE PLAINS NEXT
WEEKEND...WHICH MAY RESULT IN SOME DECENT RAIN CHANCES FOR THE
REGION. THIS IS CURRENTLY BEYOND THE VALID FORECAST PERIOD...BUT
IT IS A SYSTEM THAT WE WILL BE KEEPING A CLOSE EYE ON IN THE
COMING DAYS.
CAVANAUGH
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 49 61 44 57 43 / 5 5 5 10 10
WACO, TX 51 63 46 57 43 / 10 10 10 20 20
PARIS, TX 49 60 42 56 39 / 20 10 5 10 10
DENTON, TX 45 60 42 56 41 / 5 5 5 10 5
MCKINNEY, TX 45 60 42 57 40 / 5 5 5 10 10
DALLAS, TX 50 61 45 56 44 / 5 5 5 10 10
TERRELL, TX 49 62 44 58 40 / 10 5 5 10 10
CORSICANA, TX 52 63 45 59 43 / 20 10 10 20 20
TEMPLE, TX 51 64 46 58 44 / 10 10 10 20 20
MINERAL WELLS, TX 45 60 42 56 42 / 0 5 10 20 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
58/91
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
555 PM CST SUN DEC 7 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 221 PM CST SUN DEC 7 2014
WATER VAPOR SATELLITE IMAGERY SHOWING THE LEAD SHORT WAVE TROUGH
WAS WORKING ACROSS WESTERN MINNESOTA AND IOWA EARLY THIS
AFTERNOON. THE 07.12Z NAM AND GFS ALONG WITH THE 07.15Z RAP IN
PRETTY GOOD AGREEMENT IN SHOWING THIS WAVE BREAKING INTO TWO PARTS
AS THE AFTERNOON CONTINUES. THE NORTHERN PART OF THE WAVE EITHER
DISSIPATES AHEAD OF THE UPPER LEVEL LOW OVER NORTH DAKOTA OR MOVES
NORTHEAST TOWARD LAKE SUPERIOR. THE SOUTHERN PART OF THE WAVE IS
EXPECTED TO CONTINUE MOVING EAST/SOUTHEAST BUT GOING SOUTH OF THE
AREA ACROSS IOWA AND MISSOURI. AS THIS OCCURS...THE LINE OF RADAR
RETURNS TO THE WEST OF THE AREA IS EXPECTED TO GRADUALLY WEAKEN
AND IS NOT EXPECTED TO PRODUCE MUCH IF ANY PRECIPITATION...BUT
SHOULD HELP TO MOISTEN THE COLUMN. IT NOW APPEARS AS IF THE MAIN
PRECIPITATION BAND WILL OCCUR AHEAD OF THE SECOND AND STRONGER
SHORT WAVE TROUGH ROTATING AROUND THE UPPER LEVEL LOW. THE WAVE
WILL COME ACROSS CENTRAL AND NORTHERN MINNESOTA THIS EVENING AND
NORTHERN MINNESOTA OVERNIGHT. THIS WAVE SHOULD PRODUCE MODERATE
PV ADVECTION IN THE 500-300 MB LAYER AS IT COMES ACROSS THE REGION
WITH WEAK QG CONVERGENCE IN THE 1000-300 MB LAYER.
ISENTROPICALLY...THERE SHOULD BE 2 TO 3 UBAR/S OF UP GLIDE
OCCURRING ON THE 290K SURFACE. THIS SHOULD BE ENOUGH FORCING TO
PRODUCE A BAND OF LIGHT PRECIPITATION AHEAD OF THE SHORT WAVE
TROUGH AND WILL CONTINUE TO SHOW A BAND OF 60 TO 90 PERCENT
CHANCES WORKING WEST TO EAST ACROSS THE AREA TONIGHT. THE BIG
CONCERN WITH THIS PRECIPITATION IS WHAT TYPE IT WILL BE. THE
BUFKIT SOUNDINGS FROM BOTH THE NAM AND GFS CONTINUE TO SHOW A WARM
LAYER ALOFT WILL BE IN PLACE AS THE PRECIPITATION COMES IN TO
PRODUCE EITHER TOTAL OR PARTIAL MELTING FOR EITHER SOME FREEZING
DRIZZLE OR SLEET. EVAPORATIVE COOLING SHOULD WIPE OUT THIS WARM
LAYER WITHIN A COUPLE OF HOURS FOR A TRANSITION OVER TO LIGHT
SNOW. HOWEVER...THIS LIKELY WILL NOT CONTINUE VERY LONG BEFORE
THERE IS A LOSS OF ICE REINTRODUCING THE CHANCE FOR SOME FREEZING
DRIZZLE. THE ICE IN THE CLOUDS SHOULD MAINTAIN ITSELF LONGER OVER
THE NORTHERN SECTIONS TO KEEP THE PRECIPITATION AS LIGHT SNOW
UNTIL THE OVERNIGHT HOURS BEFORE POSSIBLY MIXING WITH SOME
FREEZING DRIZZLE. FORTUNATELY...WITH ONLY LIGHT PRECIPITATION
EXPECTED...ONLY SOME VERY LIGHT ICING MAY OCCUR. THE OTHER THING
THAT MAY MITIGATE THE ICING IS THE POTENTIAL FOR SURFACE
TEMPERATURES TO RISE AND REACH FREEZING OR ABOVE FOR AREAS
SOUTHWEST OF INTERSTATE 94. AT THIS POINT...DO NOT PLAN TO ISSUE A
WINTER WEATHER ADVISORY...BUT WILL SEND OUT A SPECIAL WEATHER
STATEMENT TO HEIGHTEN THE AWARENESS ALONG WITH A SHORT TERM
GRAPHIC CAST IMAGE.
A SECONDARY SHORT WAVE TROUGH WILL ROTATE AROUND THE UPPER LEVEL
LOW MONDAY AND PRODUCE WEAK PV ADVECTION IN THE 500-300 MB LAYER.
SOME WEAK QG CONVERGENCE SHOULD OCCUR IN THE 850-500 MB LAYER
ALONG WITH ABOUT 1 UBAR/S OF UP GLIDE ON THE 290K ISENTROPIC
SURFACE. THIS SHOULD BE ENOUGH TO MAINTAIN A CHANCE FOR SOME LIGHT
PRECIPITATION...ESPECIALLY IN THE INTERSTATE 94 CORRIDOR AND WILL
START THE DAY WITH 60 TO 70 PERCENT CHANCES GRADUALLY DECREASING
THROUGH THE DAY AS THE UPPER LEVEL LOW AND SHORT WAVE TROUGH MOVE
AWAY FROM THE AREA. STILL A CONCERN AS TO WHETHER THERE WILL BE
ICE IN THE CLOUDS AND WILL START WITH A LIGHT SNOW/FREEZING
DRIZZLE GOING TO EITHER FREEZING DRIZZLE OR DRIZZLE BASED ON
SURFACE TEMPERATURES. SOUTHWEST OF THIS AREA...THE LOW LEVEL LAPSE
RATES WILL BE INCREASING WITH VALUES OF 7 TO 10 KM/C BELOW 850 MB
BY AFTERNOON. THIS LOW LEVEL LAYER LOOKS TO BE SATURATED AND WITH
THE CYCLONIC FLOW...THERE SHOULD BE ENOUGH FORCING TO RING OUT
SOME LIGHT PRECIPITATION. FOR NOW...HAVE STAYED WITH FLURRIES AS
THE COLD AIR ADVECTION INCREASES...BUT CONCERNED THIS LAYER MAY
NOT BE COLD ENOUGH FOR ICE TO BE IN THE CLOUDS.
.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 221 PM CST SUN DEC 7 2014
RELATIVELY QUIET PERIOD EXPECTED AS HIGH PRESSURE SETS UP OVER THE
UPPER MIDWEST AND THEN REMAINS IN PLACE THROUGH THE END OF THE
WEEK. BOTH THE 07.12Z ECMWF AND GFS SHOW THE RIDGING WILL BEGIN TO
MOVE EAST OF THE REGION OVER THE UP COMING WEEKEND...BUT IT
REMAINS TO BE SEEN HOW FAST THIS WILL OCCUR. THE GFS IS QUICKER TO
DO THIS THAN EITHER THE ECMWF OR 07.12Z GEM. THE FASTER GFS THEN
ALLOWS A SHORT WAVE TROUGH TO COME OUT OF THE DEVELOPING SOUTHWEST
FLOW FOR SOME PRECIPITATION CHANCES SATURDAY NIGHT INTO SUNDAY.
WITH TEMPERATURES WARMING IN THE SOUTHWEST FLOW...THE BULK OF ANY
PRECIPITATION THAT FALLS MAY JUST BE RAIN.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 555 PM CST SUN DEC 7 2014
THE FOCUS IS ON THE DETERIORATING CONDITIONS AT RST/LSE TONIGHT. A
BAND OF RAIN AND SLEET SHOWERS IS TRACKING TO THE EAST ACROSS
SOUTHEAST MINNESOTA. FLIGHT CONDITIONS BEGIN TO DROP IMMEDIATELY
BEHIND THIS BAND TO THE WEST WITH AN INITIAL DROP TO MVFR CEILINGS
BEFORE IT DROPS DOWN TO IFR CIGS/VIS. EXPECT THAT THIS TRANSITION
WILL TAKE PLACE THIS EVENING AT RST/LSE WITH RST DROPPING DOWN
FIRST. SOME DRIZZLE WILL BE POSSIBLE AS WELL OVERNIGHT AS THESE
LOWER CEILINGS COME IN. SOME IMPROVEMENT LOOKS TO COME IN LATER
MONDAY MORNING BUT MVFR CEILINGS WILL LIKELY HOLD ON THROUGH THE
AFTERNOON.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS SAN JOAQUIN VALLEY - HANFORD CA
945 PM PST SUN DEC 7 2014
.SYNOPSIS...
HIGH PRESSURE WILL PREVAIL TODAY BEFORE ANOTHER WEAK WEATHER SYSTEM
SKIRTS ACROSS THE NORTHERN PORTION OF THE STATE ON MONDAY. A MUCH
STRONGER STORM IS EXPECTED BY LATE IN THE WEEK BRINGING A THREAT OF
PRECIPITATION TO MUCH OF THE AREA.
&&
.DISCUSSION...
FOG FORECAST REMAINS ON TRACK FOR TONIGHT. MERCED IS NOW DRIFTING
IN AND OUT OF DENSE FOG AND HRRR RUNS REMAINS STEADFAST IN
ADDITIONAL FOR FORMATION OVERNIGHT. ISSUED DENSE FOG ADVISORY IN
RESPONSE AND WILL RE-ITERATE MESSAGE ON SOCIAL MEDIA CHANNELS.
ALSO MADE SOME ADJUSTMENTS TO PRECIP CHANCES FOR THURSDAY/FRIDAY
STORM BASED ON RE-ASSESSMENT OF GFS/EC ENSEMBLE DATA AND
DETERMINISTIC FORCING PARAMETERS. IN SHORT...GIVEN VERY STRONG
MOISTURE FLUX WITH THE SYSTEM AND POTENTIAL RECORD STRENGTH FOR
DECEMBER /AS MEASURED BY MSLP/ SEEMED PRUDENT. WE ARE HIGHLY
CONFIDENT THAT IT WILL RAIN WITH THIS SYSTEM...QUESTION IS WHEN
AND HOW MUCH. BUT EVEN NOW THAT WHEN WINDOW IS SHRINKING TO
THURSDAY NIGHT AND FRIDAY. THE HOW... COULD BE A NOTABLE EVENT.
&&
.PREV DISCUSSION... /ISSUED 243 PM PST SUN DEC 7 2014/
DISCUSSION...
A WEAK FRONTAL BAND AND A COUPLE OF UPPER DISTURBANCES BRINGING
LOTS OF MID AND HIGH CLOUDS ACROSS CENTRAL CALIFORNIA. LITTLE
MEASURABLE PRECIPITATION EXPECTED. LIMITED AND PATCHY FOG
EXPECTED AS CLOUD COVER SHOULD MITIGATE FOG FORMATION. FOG MAY BE
A BIT MORE PREVALENT TUESDAY NIGHT WITH A SHORT WAVE RIDGE AND
CLEARER CONDITIONS.
MEDIUM RANGE MODELS ARE INDICATING A STRONG STORM SYSTEM WILL
AFFECT CALIFORNIA AT THE END OF THE WORKWEEK. FORECAST CONFIDENCE
IS MEDIUM AT THE MOMENT. DUE TO TIMING DIFFERENCES IN THE
OPERATIONAL MODELS. GFS IS ABOUT A DAY MORE PROGRESSIVE THAN THE
ECWF. THE ENSEMBLE MEANS OF BOTH MODELS FAVOR THE SLOWER SOLUTION
OF THE EC. THUS WILL SLOW THE ONSET OF PRECIPITATION TO LATE
THURSDAY INTO CENTRAL CALIFORNIA. MODELS ALSO DEVELOP STRONG N-S
SURFACE PRESSURE GRADIENTS ACROSS CENTRAL AND NORTH CALIFORNIA
AHEAD OF THE FRONT. HIGH WIND POTENTIAL WILL BE PROBABLE AHEAD OF
THE STORM ESPECIALLY ALONG THE WEST SIDE OF THE SAN JOAQUIN VALLEY
AND TEHACHAPIS ALONG THE GRAPEVINE AREA. BOTH OP MODELS PROG S
FLOW AROUND 50KT ALONG THE CENTRAL COAST. WIDESPREAD PRECIPITATION
WILL BE LIKELY WITH CURRENT MODELS ESTIMATING 1-2 FEET OF NEW
SNOW OVER THE SOUTHERN SIERRA NEVADA. RAINFALL AMOUNTS OVER THE
BURN SCARS NEAR YOSEMITE ARE FORECAST TO BE AROUND AN INCH...AND
ROCK AND DEBRIS FLOWS ARE POSSIBLE.
THE STORM IS FORECAST TO MOVE EAST OF CALIFORNIA SATURDAY NIGHT INTO
NEXT SUNDAY FOR A RETURN OF DRY WEATHER AND MORE CHANCES FOR NIGHT
AND MORNING SAN JOAQUIN VALLEY FOG.
&&
.AVIATION...
IN THE SAN JOAQUIN VALLEY...DENSE FOG WILL FORM OVERNIGHT FOR LIFR
CONDITIONS AT TIMES...DIFFICULT TO SAY THOUGH IF TERMINAL ON
PERIPHERY OF FOG BANK /FAT AND VIS/ WILL BE IMPACTED. BFL SHOULD
REMAIN RELATIVELY FINE. MVFR AND VFR CONDITIONS RETURN MONDAY
AFTERNOON.
&&
.AIR QUALITY ISSUES...
ON MONDAY DECEMBER 8 2014... FIREPLACE/WOOD STOVE BURNING STATUS
IS: NO BURNING UNLESS REGISTERED IN KERN AND KINGS COUNTIES.
FURTHER INFORMATION IS AVAILABLE AT VALLEYAIR.ORG
&&
.CERTAINTY...
THE LEVEL OF CERTAINTY FOR DAYS 1 AND 2 IS HIGH.
THE LEVEL OF CERTAINTY FOR DAYS 3 THROUGH 7 IS HIGH.
THIS INFORMATION IS PROVIDED AS PART OF A TRIAL PROJECT CONDUCTED
BY THE NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD.
CERTAINTY LEVELS INCLUDE LOW...MEDIUM...AND HIGH. PLEASE VISIT
WWW.WEATHER.GOV/HNX/CERTAINTY.PHP /ALL LOWER CASE/ FOR ADDITIONAL
INFORMATION AND/OR TO PROVIDE FEEDBACK.
&&
.CLIMATE...
RECORDS
SITE DATE HI_MAX:YEAR LO_MAX:YEAR HI_MIN:YEAR LO_MIN:YEAR
KFAT 12-07 69:1937 42:1965 52:1950 25:1978
KFAT 12-08 77:2006 42:1965 50:1897 25:1978
KFAT 12-09 70:1950 38:1972 53:1902 23:1972
KBFL 12-07 76:1907 41:1965 53:1950 24:1912
KBFL 12-08 83:1915 43:1965 52:1949 24:1903
KBFL 12-09 74:1979 36:1972 52:1955 24:1923
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 10 AM PST MONDAY CAZ089>092.
&&
$$
PUBLIC...INIGUEZ
AVN/FW...INIGUEZ
PREV DISCUSSION...MV
SYNOPSIS...BSO
WEATHER.GOV/HANFORD
AREA FORECAST DISCUSSION
NWS MIAMI FL
406 AM EST MON DEC 8 2014
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH TONIGHT...USHERING IN AN EXTENDED
PERIOD OF NORTHWEST WINDS AND BELOW NORMAL TEMPERATURES. HIGH
PRESSURE WILL DOMINATE.
&&
.SHORT TERM /TODAY THROUGH WEDNESDAY/ ...
BEHIND YESTERDAYS COLD FRONT...TEMPS EARLY THIS MORNING ARE QUITE
A BIT COOLER THAN PREV FEW MORNINGS...WITH LOW 60S ALONG THE
COASTS AND 50S ELSEWHERE. LOW STRATUS/SOME VSBY RESTRICTIONS IS
PUSHING SOUTHWARD INTO GLADES AND HENDRY COUNTIES. HOW FAR SOUTH
THIS CLOUD LAYER ADVANCES IS UNCERTAIN...BUT IT APPEARS THAT AT
LEAST NORTH OF A NAPLES TO BOCA RATON LINE...MOSTLY CLOUDY
CONDITIONS WILL PREVAIL INTO LATE MORNING. NW WINDS WILL TURN NE
THIS AFTERNOON...AND TEMPERATURES SHOULD RISE TO NEAR
NORMAL...MID/UPR 70S. NE FLOW WILL BRING SOME LOW-LEVEL MOISTURE
DOWN THE E FL COASTLINE...AND THIS COULD BE ENOUGH TO BRING INLAND
A FEW SHOWERS INTO PALM BEACH COUNTY. THESE MAY CONTINUE INTO
EARLY TUESDAY...BEFORE A COLD FRONT BRINGS MUCH DRIER AIR INTO THE
REGION. MINIMA TONIGHT WILL ALSO BE NEAR AVERAGE FOR EARLY
DECEMBER...MAINLY IN THE MID/UPR 50S...WITH SOME LOW 60S ACROSS
THE EASTERN METROPOLITAN AREAS.
A POTENT SHORTWAVE TROUGH WILL DIVE THROUGH THE GREAT LAKES TODAY
AND INTO THE CENTRAL APPALACHIANS TONIGHT. BEHIND THE
TROUGH...CANADIAN HIGH PRESSURE WILL EXPAND THROUGH THE PLAINS AND
EVENTUALLY THE MISSISSIPPI RIVER VALLEY. THE TROUGHS ATTENDANT
SURFACE CDFNT WILL MOVE THROUGH THE OHIO VALLEY TODAY...WHILE
SURFACE LOPRES DEVELOPS OFF CAROLINAS. THE LOW WILL ACCELERATE THE
ARRIVAL OF THE FRONT INTO SOUTH FLORIDA AND ALSO INCREASE THE
COLD-AIR ADVECTION ASSOCIATED WITH IT. SIGNIFICANT COOLING WILL
OCCUR BY TUESDAY NIGHT AS THE UPPER TROUGH AXIS QUIETLY PASSES
BY. MINIMAS SHOULD REACH 40S OVER THE INTERIOR...WITH LOW 50S ALL
THE WAY TO THE EAST COAST. WIND CHILL VALUES WILL BE A FEW DEGREES
LOWER THAN THE TEMPERATURE OVERNIGHT. WEDNESDAY...CANADIAN RIDGE
BECOMES MORE ENTRENCHED OVER SOUTH FLORIDA...AND MAXIMA WILL HOLD
IN THE 60S.
SIGNIFICANT NE SWELL BEING TO ARRIVE IN SOUTH FLORIDA WATERS
TODAY /SEE DETAILS IN THE MARINE DISCUSSION BELOW/. THIS WILL LEAD
TO SIGNIFICANT RIP CURRENTS ALONG ATLANTIC BEACHES THROUGH AT
LEAST MID-WEEK. IN ADDITION...HIGH SURF MAY WARRANT AN ADVISORY
TUESDAY OR WEDNESDAY...AND BEACH EROSION/MINOR COASTAL
FLOODING...ARE ALSO POTENTIAL HAZARDOUS.
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/ ...
AFOREMENTIONED SHORTWAVE TROUGH WILL DEEPEN FURTHER AND EVOLVED
INTO CLOSED H5 LOPRES OVER NE CONUS. THE FEATURE WILL THEN
STALL...AT LEAST INTO THE WEEKEND. MEANWHILE...EXPANSIVE SFC
RIDGE WILL REMAIN CENTERED NORTHWEST OF THE STATE. FOR SOUTH
FLORIDA...THIS MEANS EXPECT AN EXTENDED PERIOD OF NORTHWEST WINDS
WITH A COOL CANADIAN AIRMASS CONTINUING TO FILTER IN MUCH OF THE
WEEK. SKIES WILL BE MAINLY CLEAR. OVERNIGHT LOWS SHOULD MAINLY BE
IN 40S INTERIOR/50S METROPOLTIAN AREAS...WITH DAYTIME HIGHS IN THE
UPPER 60S TO LOW 70S. ALTHOUGH LONG-RANGE MODELS GENERALLY AGREE
ON THIS PATTERN CONTINUING INTO THE WEEKEND...LATEST ECMWF RUN
BRINGS ADDITIONAL REINFORCEMENTS OF COOL AIR DOWN THE PENINSULA.
IF THIS PANS OUT...FORECAST TEMPERATURES MAY BE SEVERAL DEGREES TO
WARM FOR THE END OF THE WEEK.
&&
.AVIATION...
STILL MONITORING A SHIELD OF LOW CIGS PUSHING SOUTH ACROSS THE
CENTRAL FLORIDA PENINSULA PER THE LATEST MICRON SATELLITE IMAGERY.
THE TIMING AND EXACT EXTENT OF THE SOUTHERN PROPAGATION OF THIS
SHIELD REMAINS IN QUESTION. LATEST HRRR AND SREF CIG HEIGHT
PROBABILITIES KEEP THE MAJORITY OF THE LOW CIGS ACROSS THE
INTERIOR WITH THE PERIPHERY OF WHICH EXTENDING TO BOTH THE
ATLANTIC AND GULF COASTS...POSSIBLY AFFECTING THE TAF SITES. KEPT
ANY MVFR/IFR CIGS OUT OF TAFS FOR NOW DUE TO UNCERTAINTY BUT WILL
CONTINUE TO MONITOR AND AMEND AS NECESSARY. OTHERWISE...LIGHT
NORTH-NORTHWESTERLY FLOW WILL PREVAIL AT THE EAST COAST SITES
THROUGH THE MORNING WITH NORTHEASTERLY FLOW AT KAPF.
&&
.MARINE...
IMPRESSIVE FETCH GENERATED BY LOPRES WEST OF BERMUDA IS BRINGING
NELY SWELL DOWN THE FLORIDA PENINSULA EARLY THIS MORNING. WAVE
HEIGHTS ARE ALREADY EXCEEDING 10 FT OFFSHORE THE MELBOURNE/CAPE
CANAVERAL AREA...AND WILL LIKELY REACH WATERS OFF PALM BEACH
COUNT THIS AFTERNOON...THEN THE REMAINDER OF ATLANTIC WATERS
TONIGHT. SMALL CRAFT ADVISORIES HAVE BEEN ISSUED ACCORDINGLY. THE
5 TO 8 FOOT SWELL WILL PERSIST TUESDAY INTO WEDNESDAY...LEADING TO
A CONTINUATION OF HAZARDOUS MARINE CONDITIONS. WAVES IN THE GULF
STREAM MAY EXCEED 13 FEET DURING THIS TIME.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 76 61 73 50 / 30 10 10 0
FORT LAUDERDALE 78 62 75 54 / 10 0 10 0
MIAMI 78 62 75 53 / 10 0 0 0
NAPLES 74 58 71 50 / 10 0 0 0
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 7 PM EST TUESDAY
FOR AMZ651-671.
SMALL CRAFT ADVISORY FROM 7 AM THIS MORNING TO 7 PM EST TUESDAY
FOR AMZ650-670.
GM...NONE.
&&
$$
SHORT TERM...23/SK
LONG TERM....23/SK
AVIATION...10/CD
AREA FORECAST DISCUSSION
NWS MIAMI FL
109 AM EST MON DEC 8 2014
.AVIATION...
STILL MONITORING A SHIELD OF LOW CIGS PUSHING SOUTH ACROSS THE
CENTRAL FLORIDA PENINSULA PER THE LATEST MICRON SATELLITE IMAGERY.
THE TIMING AND EXACT EXTENT OF THE SOUTHERN PROPAGATION OF THIS
SHIELD REMAINS IN QUESTION. LATEST HRRR AND SREF CIG HEIGHT
PROBABILITIES KEEP THE MAJORITY OF THE LOW CIGS ACROSS THE
INTERIOR WITH THE PERIPHERY OF WHICH EXTENDING TO BOTH THE
ATLANTIC AND GULF COASTS...POSSIBLY AFFECTING THE TAF SITES. KEPT
ANY MVFR/IFR CIGS OUT OF TAFS FOR NOW DUE TO UNCERTAINTY BUT WILL
CONTINUE TO MONITOR AND AMEND AS NECESSARY. OTHERWISE...LIGHT
NORTH-NORTHWESTERLY FLOW WILL PREVAIL AT THE EAST COAST SITES
THROUGH THE MORNING WITH NORTHEASTERLY FLOW AT KAPF.
&&
.PREV DISCUSSION... /ISSUED 819 PM EST SUN DEC 7 2014/
UPDATE...
A COLD FRONT WAS LOCATED OVER THE FLORIDA STRAITS THIS EVENING
WILL CONTINUE TO MOVE SOUTHWARD TONIGHT AS HIGH PRESSURE CONTINUES
TO BUILD INTO THE SOUTHEASTERN UNITED STATES FROM THE WEST.
THIS WILL KEEP THE WIND FLOW OVER SOUTH FLORIDA IN A NORTHERLY
DIRECTION TONIGHT OVER SOUTH FLORIDA ALONG WITH MOSTLY DRY
WEATHER. THE ONLY EXCEPTION IS FOR A FEW SHOWERS COULD WORK INTO
THE METRO AREAS OF PALM BEACH COUNTY FROM THE ATLANTIC WATERS
OVERNIGHT. THEREFORE...A SLIGHT CHANCE OF SHOWERS WILL REMAIN IN
THE FORECAST FOR METRO AREAS OF PALM BEACH COUNTY TONIGHT WITH
REST OF SOUTH FLORIDA REMAINING DRY.
REST OF THE FORECAST LOOKS GOOD AT THIS TIME AND NO OTHER CHANGES
ARE PLANNED.
UPDATED...54/BNB
PREV DISCUSSION... /ISSUED 250 PM EST SUN DEC 7 2014/
DISCUSSION...
THE PUBLIC HAS REPORTED SMOKE IN NORTHERN BROWARD COUNTY FROM THE
SUGAR CANE BURNS ACROSS SOUTHERN PALM BEACH COUNTY. STRATUS
CONTINUES ACROSS THE NORTHERN PORTION OF SOUTH FLORIDA EARLY THIS
AFTERNOON AS A WEAK FRONT MOVES SOUTHWARD TOWARDS LAKE OKEECHOBEE.
CLOUD COVER WAS BEGINNING TO ERODE...AND GUIDANCE INDICATES THAT
THE CLOUD COVER WILL BREAK UP BY MID/LATE AFTERNOON AS THE FRONT
PUSHES SOUTHWARD. OUTSIDE OF THE CLOUD COVER...THE FRONT WILL HAVE
LITTLE IMPACT ON SOUTH FLORIDA. THE CLOUD COVER ACROSS NORTHERN
FLORIDA WILL LIKELY KEEP TEMPS IN THE LOW 70S THIS
AFTERNOON...WITH TEMPS IN THE UPPER 70S AND LOW 80S SOUTH.
MONDAY AND TUESDAY...THE GFS AND ECMWF ARE IN GOOD AGREEMENT WITH
A SOUTHERN STREAM SHORTWAVE MOVING ACROSS THE NORTHERN GULF COAST
AND PUSHING THROUGH THE FLORIDA PENINSULA MONDAY INTO TUESDAY
MORNING. LIFT AHEAD OF THIS TROUGH ALONG WITH SUFFICIENT LOW LEVEL
MOISTURE IN THE NORTHERLY FLOW MAY ALLOW A FEW SHOWERS TO DEVELOP
AND MOVE ACROSS PALM BEACH COUNTY AND THE LAKE REGION LATE TONIGHT
THROUGH MONDAY NIGHT. THE NORTHERN STREAM TROUGH ACROSS THE UPPER
GREAT LAKES MONDAY MORNING WILL DIVE SOUTHEASTWARD...WITH RAPID
CYCLOGENESIS OCCURRING OFF THE NORTH CAROLINA COASTLINE. HIGH
PRESSURE WILL SURGE FROM CANADA INTO THE SOUTHERN PLAINS AND
SOUTHEAST...WITH SIGNIFICANT COOLING AND DRYING ACROSS SOUTH
FLORIDA ON TUESDAY. A SIGNIFICANT NORTHEASTERLY SWELL IS FORECAST
TO PUSH INTO SOUTH FLORIDA BEGINNING MONDAY AFTERNOON...WITH A
LARGE SWELL OF 5 TO 8 FEET PUSHING INTO THE ATLANTIC WATERS MONDAY
NIGHT AND TUESDAY. A HIGH SURF ADVISORY MAY BE REQUIRED FOR PALM
BEACH COUNTY ON TUESDAY. MINOR BEACH EROSION IS ALSO POSSIBLE.
SOUTH FLORIDA WILL BE MAINLY INFLUENCED BY EXPANSIVE CANADIAN
SURFACE RIDGE...WHOSE CENTER WILL REMAIN ANCHORED OVER THE
MISSISSIPPI VALLEY THROUGH THE LONG TERM PERIOD. AFOREMENTIONED
SHORTWAVE TROUGH WILL DEEPEN AND CLOSE OFF OVER NEW ENGLAND...AND
ALSO BECOME NEARLY STATIONARY DURING THIS TIME. FOR SOUTH
FLORIDA...THESE FEATURES WILL TRANSLATE TO PERSISTENT NNW
FLOW...WITH MODERATE CAA...LIKELY THROUGH THE END OF THE WORK-
WEEK. DEEP-LAYER DRY AIR WILL ENTRENCH OVER THE REGION. DESPITE
AMPLE SUN...TEMPERATURES WILL BE BELOW NORMAL. HIGHS WILL BE
MAINLY IN THE LOW 70S...ALTHOUGH WEDNESDAY MAXIMA EXPECTED TO ONLY
BE IN 60S. MINIMA OVER THE INTERIOR WED-FRI NIGHT WILL BE IN
40S...WITH 50S EXPECTED AT THE COASTS.
MARINE...
NORTHERLY WINDS WILL INCREASE THIS AFTERNOON AND EVENING ACROSS
THE REGIONAL WATERS AS A WEAK COLD FRONT MOVES THROUGH THE REGION.
A SIGNIFICANT NORTHEASTERLY SWELL WILL PUSH INTO THE ATLANTIC
WATERS BEGINNING MONDAY AFTERNOON...WITH SWELL HEIGHTS INCREASE TO
5 TO 8 FEET MONDAY NIGHT INTO TUESDAY. WAVE HEIGHTS ARE FORECAST
TO INCREASE TO 8 TO 12 FEET OVER THE GULF STREAM MONDAY NIGHT AND
TUESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 76 60 72 52 / 20 20 10 0
FORT LAUDERDALE 77 62 74 54 / 10 10 10 0
MIAMI 77 62 74 54 / 10 10 10 0
NAPLES 73 58 71 51 / 10 10 0 0
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1213 AM CST MON DEC 8 2014
.UPDATE...
914 PM...EVENING UPDATE...OVERALL NO SIGNIFICANT CHANGES TO THE
FORECAST FOR OVERNIGHT OR MONDAY MORNING. FAIRLY NARROW BAND OF
PRECIP IS MOVING ACROSS EAST CENTRAL IA THIS EVENING. A FEW
LIGHTNING STRIKES OCCURRED EARLIER THIS EVENING NEAR KMCW IN
NORTHERN IA. AUTOMATED SITES HAVE REPORT UNKNOWN PRECIP...HEAVY IN
FEW OBS...WITH SURFACE TEMPS AT OR JUST ABOVE FREEZING.
DESPITE OBSERVED 00Z ILX/DVN SOUNDINGS SHOWING +8C AND +6C TEMPS
AROUND 900MB RESPECTIVELY...THERE REMAINS QUITE A BIT OF DRY AIR
THAT WILL NEED TO SATURATE...LIKELY VERY QUICKLY...AS PRECIP
ARRIVES. THUS THIS WARM LAYER WILL LIKELY BE COOLED SUFFICIENTLY
FOR A WINTRY MIX AT FIRST...THEN IF PRECIP INTENSITY BECOMES HEAVY
ENOUGH...A SHORT PERIOD OF SNOW. CONFIDENCE IS TOO LOW TO MAKE ANY
SIGNIFICANT CHANGES TO THE CURRENT FORECAST. ONLY MINOR CHANGE WAS
TO TWEAK TIMING TO SLOW PRECIP ONSET.
AIR TEMPS HAVE COOLED INTO THE UPPER 20S/NEAR 30 ACROSS MUCH OF
THE NORTHWEST CWA...WITH TEMPS STILL NEAR FREEZING OVER THE REST
OF THE CWA. SURFACE TEMPS MAY WARM A FEW DEGREES BUT WILL LIKELY
STAY NEAR FREEZING THRU DAYBREAK. SO REGARDLESS OF PRECIP TYPE...
SOME ICING OF UNTREATED SURFACES IS POSSIBLE...ESPECIALLY WHERE
TEMPS ARE NOW IN THE UPPER 20S. NO PLANS FOR ANY HEADLINES THIS
EVENING...BUT THAT POSSIBILITY WILL NEED TO BE MONITORED AS TRENDS
EMERGE OVERNIGHT. THUS NO PLANS TO MODIFIED CURRENT SPS WHICH
RUNS THROUGH 09Z. CMS
&&
.SHORT TERM...
TONIGHT THROUGH MONDAY... 314 PM CST
THE MAIN WEATHER CONCERN FOR TONIGHT INTO MONDAY IS THE QUICK HIT
OF A WINTERY MIX LATE TONIGHT INTO MONDAY MORNING...WITH THE
POTENTIAL OF BRIEF PERIOD OF A HEAVY BURST OF SNOW ACROSS FAR
NORTHERN ILLINOIS EARLY MONDAY MORNING DURING THE MORNING RUSH.
WATER VAPOR IMAGERY INDICATES OUR STORM SYSTEM OF INTEREST DIGGING
EAST-SOUTHEASTWARD ACROSS THE NORTHERN HIGH PLAINS. THE ASSOCIATED
AREA OF SURFACE LOW PRESSURE IS EXPECTED TO TRACK QUICKLY ALONG OR
NEAR THE CANADIAN BORDER THROUGH TUESDAY. WARM AIR
ADVECTION/ISENTROPIC ASCENT IS ALREADY RAMPING UP ACROSS THE AREA
OUT AHEAD OF THIS FEATURE...AND REGIONAL RADAR TRENDS ARE BEGINNING
TO SHOW PRECIPITATION DEVELOPING TO OUR WEST-NORTHWEST IN ASSOCIATION
WITH THE APPROACHING SURFACE FRONTAL BOUNDARY.
THE COMBINATION OF GOOD LARGE SCALE FORCING (Q-VECTOR CONVERGENCE)
ASSOCIATED WITH THE APPROACHING MID LEVEL SHORT WAVE ENERGY...ALONG
WITH WHAT APPEARS MAY END UP BEING A RATHER STOUT BAND OF MID LEVEL
FRONTOGENESIS...SHOULD PROVIDE A SHORT...BUT POTENTIALLY INTENSE
PERIOD OF PRECIPITATION ACROSS NORTHERN ILLINOIS/NORTHWESTERN
INDIANA EARLY MONDAY MORNING. MODEL SOUNDINGS ACROSS THE AREA ALL
INDICATE THE PRESENCE OF SOME VERY IMPRESSIVE MID LEVEL LAPSE RATES
(UP AROUND 7 DEGREES C/KM IN THE 700-500 MB LAYER) DURING THE PERIOD
OF MAXIMUM FORCING FOR ASCENT. IN ADDITION...CROSS SECTIONS ACROSS
NORTHERN ILLINOIS ALSO INDICATE THE PRESENCE OF NEGATIVE EPV...WITH
FOLDING THETA E SURFACES IN THE 500 TO 700 MB LAYER. THIS ALL
POINTS TO THE LIKELIHOOD OF A SHORT...BUT POTENTIALLY INTENSE BAND OF
PRECIPITATION DURING THE MORNING RUSH ACROSS NORTHERN
ILLINOIS/NORTHWESTERN INDIANA. THE CURRENT TIMING FOR THE CHICAGO
METRO AREA FOR THIS BAND OF HEAVY PRECIPITATION LOOKS TO BE IN THE
12 TO 15 UTC TIME FRAME...AND AN COUPLE HOURS EARLIER ACROSS NORTH
CENTRAL ILLINOIS.
MODEL GUIDANCE CONTINUES TO SUGGEST THERMAL PROFILES WILL BE
MARGINAL FOR SNOWFALL...WITH MAX LAYER WET BULB TEMPERATURES FROM
ZERO TO +1 CELSIUS. HOWEVER...GIVEN THE LIKELIHOOD OF AN INTENSE
PRECIPITATION RATES WITHIN THIS AREA OF PRECIP...I FEEL THAT
SNOW...WITH SLEET IS STILL LIKELY TO BE THE PRIMARY PRECIPITATION
TYPES...ESPECIALLY NORTH OF INTERSTATES 80 AND 88...WHERE THE
STRONG MESOSCALE FORCING...AND HENCE MOST INTENSE DYNAMIC COLUMN
COOLING WILL BE MOST LIKELY. HOWEVER...A VERY SHORT PERIOD OF
RAIN/FREEZING RAIN IS ALSO POSSIBLE AS THE PRECIPITATION INITIALLY
FIGHTS WITH A WARM BUT DRY LAYER AROUND 850 MB...BUT EVAPORATIVE
COOLING SHOULD LEAD TO A RATHER QUICK CHANGE OVER TO SNOW. A QUICK
INCH OF SNOW IS POSSIBLE...ESPECIALLY ALONG AND NORTH OF I88. WE
WILL ISSUE AN SPS TO HIGHLIGHT THIS...AS IT APPEARS IT WILL BE A
QUICK BURST OF SNOW DURING THE MONDAY MORNING RUSH.
SOUTH OF INTERSTATE 80 SOME SNOW AND SLEET IS STILL
POSSIBLE...BUT RAIN...AND EVEN A BRIEF PERIOD OF FREEZING RAIN IS
EXPECTED INTO MONDAY MORNING...DUE TO SLIGHTLY WARMER MID-LEVEL
TEMPERATURES. SURFACE TEMPERATURES WILL BE HOVERING RIGHT AROUND
FREEZING INTO EARLY MONDAY MORNING...SO SOME MINOR ICING IS
POSSIBLE...BUT I DONT SEE THIS AS MUCH OF FREEZING RAIN EVENT.
PRECIPITATION SHOULD BE QUICK TO MOVE EAST OF THE AREA...BY MIDDAY TO
EARLY AFTERNOON. GUIDANCE INDICATES THAT THE MID LEVELS WILL DRY OUT
IN A HURRY LATER MONDAY MORNING/EARLY AFTERNOON. THUS IT APPEARS ANY
LINGERING PRECIP WILL BE IN THE FORM OF VERY LIGHT RAIN OR
DRIZZLE...AND GIVEN THAT TEMPERATURES SHOULD WARM WELL INTO THE 30S
TOMORROW AFTERNOON AHEAD OF THE APPROACHING COLD FRONT...FREEZING
WILL NOT BE AN ISSUE DURING THE AFTERNOON.
KJB
&&
.LONG TERM...
258 PM CST
MONDAY NIGHT THROUGH NEXT WEEKEND...
AN EXTENSION OF THE UPPER LOW FROM THE AFOREMENTIONED SYSTEM WILL
MOVE OVER THE AREA MONDAY EVENING ALONG WITH REINFORCED LOW-LEVEL
COLD ADVECTION AS A SECONDARY MORE CONTINENTAL COLD FRONT MOVES
SOUTHWARD THROUGH THE AREA. FORECAST LIFT IS DISJOINTED SO NOT
EXPECTING MUCH IF ANY PRECIPITATION...BUT DID ADD A CHANCE OF
DRIZZLE AND FLURRIES MONDAY EVENING. VERTICAL SATURATION PROFILES
REMAIN IFFY FOR ICE PRESENCE SO FELT COMFORTABLE MENTIONING EITHER
OR. WITH TEMPERATURES COOLING CANT RULE OUT FREEZING DRIZZLE IF SOME
PATCHY DRIZZLE WERE TO OCCUR...BUT AGAIN A LOW CHANCE.
AS THE SYSTEM MOVES EAST-SOUTHEAST ON TUESDAY IT WILL ABSORB A
SOUTHERN STREAM SYSTEM PRESENTLY ACROSS THE SOUTHERN
PLAINS...FORMING A DEEP OCCLUDING LOW ACROSS THE NEW ENGLAND REGION.
LONG RANGE GUIDANCE IS IN GOOD AGREEMENT WITH THIS. WITH BLOCKED
FLOW OVER THE NORTHERN/MID ATLANTIC...THIS LOW WILL MOVE LITTLE
THROUGH MIDWEEK...WITH THE OVERALL PATTERN BECOMING BLOCKED AND
CONSIDERABLY SLOWER ACROSS THE COUNTRY. THIS MEANS QUIET WEATHER FOR
OUR AREA FROM TUESDAY ONWARD. TEMPERATURES LOOK TO BE NEAR
NORMAL...MAYBE SLIGHTLY BELOW...DURING MIDWEEK.
A BUILDING UPPER RIDGE ACROSS THE ROCKIES DURING MIDWEEK WILL
INCH/LEAN EASTWARD...HOWEVER THE LOW-LEVEL THERMAL RIDGE WILL LAG
THIS. WHILE HEIGHTS WILL BE WELL ABOVE NORMAL OVER THE AREA...THE
GREATEST HEIGHT AND THERMAL ANOMALIES LOOK TO REMAIN TO THE WEST AND
NORTHWEST OF THE AREA ON ENSEMBLE GUIDANCE AND THE TREND HAS BEEN
THIS WAY. TEMPERATURES ARE STILL ON THEIR WAY TO ABOVE NORMAL WITH
THE CHANCE OF HAVING NEXT WEEKEND IN THE 50S...BUT RIGHT NOW WITHOUT
STRONG LOW-LEVEL WARM ADVECTION THE MAGNITUDE MAY BE HINDERED SOME.
DO THINK THE GFS IS TOO ROBUST ON LOW-LEVEL MOISTURE OVER THE
WEEKEND SO HAVE LEANED MORE TOWARD THE MORE SUNNY ECMWF /ESPECIALLY
FOR SATURDAY/. THE ECMWF HAS HIGHS IN THE MID-UPPER 40S. GIVEN THE
PATTERN...ANY PRECIPITATION CHANCES ARE LIKELY TO SLOW FURTHER SO
HAVE BACKED ANY UP UNTIL SUNDAY NIGHT.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* PERIOD OF MIXED PRECIPITATION STARTING AROUND 11/12Z. LIKELY
BEGINNING AS -FZRA/IP MIX THEN CHANGING TO SN/IP WITH SOME
ACCUMULATION POSSIBLE. MDW MAY BE WARM ENOUGH FOR -RA/IP BEFORE
SN/IP.
* CIGS QUICKLY LOWER TO MVFR/IFR AS PRECIP ARRIVES. VSBY ALSO
FALLS TO MVFR WITH PERIOD OF IFR POSSIBLE. MVFR AND POSSIBLY IFR
CONTINUES THROUGH THE AFTERNOON WITH LIGHT RAIN OR DRIZZLE.
* SOUTH WINDS BECOME SOUTHWEST BY EARLY AFTERNOON AND WEST-
NORTHWEST THIS EVENING. GUSTS 15-20 KT DEVELOP THIS EVENING.
MDB
//DISCUSSION...UPDATED 06Z...
PRECIPITATION TYPE REMAINS THE MAIN FORECAST CHALLENGE...FOLLOWED
BY CIG TRENDS. A BAND OF MIXED PRECIP CONTINUES TO WORK EASTWARD
ACROSS EASTERN IOWA AND WILL CROSS THE TERMINALS DURING THE
MORNING. HAVE MADE LITTLE CHANGE TO TIMING FROM THE PREVIOUS
FORECAST BUT MAY NEED TO SLOW THINGS SLIGHTLY...ESPECIALLY FURTHER
EAST AT MDW/GYY. A VERY WARM NOSE OF AIR IS POSITIONED ALOFT OF
THE AREA WITH A VERY DRY WEDGE OF AIR ALSO IN PLACE ABOVE THE
SURFACE. THIS WILL BE THE COMPLICATING FACTOR FOR BOTH TIMING AND
PRECIP TYPE. UPSTREAM OBS HAVE SHOWN RAIN...SLEET AND SOME
FREEZING RAIN SO FAR WITH NO SNOW NOTED. THE BAND MAY BETTER
ORGANIZE AS IT MOVES EAST WHICH WOULD GIVE AT LEAST SOME SUPPORT
FOR SNOW TO AT LEAST MIX IN BUT GIVEN THE MAGNITUDE OF THE WARM
AIR ALOFT IT MAY BE DIFFICULT FOR THIS TO OCCUR...DESPITE PLENTY
OF COOLING POTENTIAL THANKS TO THE DRY AIR. WILL STICK WITH THE
TEMPO FOR ALL SNOW WITH IFR VSBY FOR NOW AT ALL SITES BUT
GYY...BUT CONFIDENCE IN THIS OCCURRING IS LOWERING.
ULTIMATELY...RAIN/FREEZING RAIN/SLEET ARE LOOKING TO BE THE MAIN
PRECIP TYPES AT THE TERMINALS...THOUGH RFD MAY STILL HAVE A FAIR
CHANCE FOR SOME SNOW AS WELL. AS FAR AS FZRA...SURFACE AIR TEMPS
LOOK TO HOLD STEADY OR EVEN WARM A DEGREE OVERNIGHT SO FZRA IS
EXPECTED AT ORD/RFD/DPA FOR A TIME BEFORE WARMING OCCURS. PROVIDED
MDW HOLDS NEAR THEIR CURRENT 35 DEGREES THEN FZRA WOULD LIKELY NOT
BE AN ISSUE. WILL MONITOR THEIR TEMP THE NEXT FEW HOURS AND CHANGE
FZRA TO RA IF TEMP HOLDS.
CIGS WILL QUICKLY LOWER AS THE PRECIPITATION ARRIVES AND EXPECT
THERE WILL BE SOME PERIODIC IFR CIGS. IFR VSBY LOOKS TO OCCUR
PERIODICALLY BUT IF SNOW REMAINS MIXED OR DOES NOT OCCUR THEN SUB
1SM VSBY WOULD NOT BE LIKELY. THE BULK OF THE PRECIP WILL PASS
AFTER ABOUT 2-3 HOURS BUT SOME LIGHT RAIN...POSSIBLY MIXED WITH
SNOW NORTH...AND DRIZZLE LOOKS TO CONTINUE INTO MIDDAY KEEPING
VSBY REDUCED AT TIMES WHILE CIGS REMAIN LOW END MVFR AND POSSIBLY
IFR AT TIMES. SPOTTY AREAS OF LIGHT RAIN MAY PERSIST THROUGH THE
AFTERNOON.
SOUTH WINDS WILL TURN SOUTHWEST THROUGH THE MORNING THEN WEST-
NORTHWEST THIS EVENING AS A COLD FRONT PASSES. A FURTHER NORTHWEST
SHIFT IS EXPECTED EARLY TUESDAY MORNING. SPEEDS WILL INCREASE
MODESTLY THIS EVENING WITH GUSTS UP TO AROUND 20 KT DEVELOPING.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM-HIGH CONFIDENCE IN BAND OF MIXED PRECIPITATION OCCURRING
THIS MORNING. MEDIUM-HIGH CONFIDENCE IN TIMING THOUGH SLIGHT
SLOWING POSSIBLE. LOW CONFIDENCE THAT A PERIOD OF ALL SN OCCURS.
* HIGH CONFIDENCE IN FALLING CIGS/VSBY WITH PERIODIC IFR IN
PRECIPITATION. HIGH CONFIDENCE THAT MVFR PREVAILS THIS
AFTERNOON/EVENING. LOW CONFIDENCE IN POTENTIAL FOR IFR THIS AFTERNOON.
* HIGH CONFIDENCE IN WIND TRENDS THROUGH THE PERIOD.
MDB
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
TUESDAY...MVFR CIGS PSBL EARLY...THEN MAINLY VFR. LAKE EFFECT
RAIN/SNOW SHOWERS EAST OF ORD/MDW OVER LAKE. NW WINDS BECOMING N.
WEDNESDAY...VFR. N WINDS.
THURSDAY...VFR. W WINDS BECOMING WSW.
FRIDAY...MAINLY VFR...THOUGH MVFR CIGS PSBL. SW WINDS.
SATURDAY...MAINLY VFR...THOUGH MVFR CIGS PSBL. S WINDS.
RATZER
&&
.MARINE...
203 PM CST
SOUTHEAST TO SOUTH WINDS WILL CONTINUE TO INCREASE TONIGHT AHEAD OF
QUICK MOVING LOW PRESSURE ACROSS THE UPPER MIDWEST...INCLUDING
POSSIBLY TEMPORARY GALES ACROSS THE FAR NORTH. THE SOMEWHAT ONSHORE
FLOW TONIGHT INTO NORTHEAST ILLINOIS...MAINLY NORTH OF
CHICAGO...STILL LOOKS TO BRING SMALL CRAFT ADVISORY CONDITIONS THERE
INTO EARLY MONDAY MORNING. AS THE LOW TRACKS FROM LAKE SUPERIOR TO
LAKE HURON MONDAY AND MONDAY NIGHT...WINDS WILL TURN TO WEST ON
MONDAY EVENING AND THEN NORTHWEST LATE MONDAY NIGHT AND FINALLY TO
NORTH BY MIDDAY TUESDAY. WIDESPREAD 30 KT WINDS ARE EXPECTED
TUESDAY IN THIS COLD AIR ADVECTION. THE WEATHER PATTERN IS
FORECAST TO BECOME VERY BLOCKED FOR THE LATTER HALF OF THE
WEEK...WITH THE LAKE LOCKED BETWEEN A RIDGE TO ITS IMMEDIATE WEST
AND A LOW OVER THE NORTHEAST. THIS MEANS GENERALLY 10-15 KT
NORTHWEST TO WEST WINDS.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO NORTHERLY IS UNTIL 10 AM MONDAY.
&&
$$
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1113 PM CST Sun Dec 7 2014
.UPDATE...
ISSUED AT 835 PM CST SUN DEC 7 2014
Impressive shortwave seen on water vapor loop over eastern North
Dakota this evening tracking east-southeast. At the surface, a
large area of high pressure near Lake Erie will continue to drift
slowly away from our area. However, in its wake, there was quite
a bit of dry air in the lower levels as seen on the 00z ILX
sounding. As winds turn more southerly later tonight we do expect
a gradual increase in moisture at the mid and eventually lower
levels of the atmosphere, especially by dawn Monday. With the
stronger upper forcing expected to remain well north of our area
Monday morning, we expect the more significant wintry precip to
stay north of the forecast area as well. However, we will see a
brief period of rain develop after 1 or 2 am across the west and
then track east over the remainder of the area by dawn.
Except for the far northern counties, forecast soundings were
trending a bit warmer late tonight and first thing Monday morning
just ahead of a surface trof with temperatures expected to edge up
into the mid or upper 30s with the warmest readings over the
central and south. Soundings near Galesburg east thru Lacon and
southeast to just north of Bloomington indicate a narrow window of
opportunity for a little sleet or light freezing rain before going
over to rain by morning. Will continue to hold on to that idea
over the far north but based on the RAP, HRRR and latest NAM-WRF
soundings it appears the majority of the area will see mainly the
threat for rain overnight and into Monday morning ahead of the
surface trof/cold front.
Other than some minor adjustments to precip type over the far
north, the current forecast seems to be handling the situation
well for the overnight hours. We should have an updated ZFP out
by 900 pm.
&&
.SHORT TERM...(Tonight)
ISSUED AT 304 PM CST SUN DEC 7 2014
Mid and high clouds are expansive across the forecast area this
afternoon, although some patches of stratocumulus have been
developing. Larger shield of clouds around 1500 feet starting to
cross the Missouri/Illinois border as well. Water vapor imagery
showing the incoming clipper system quite nicely over the Dakotas.
Latest surface map shows the low center over northern North Dakota,
and its trailing cold front into central Nebraska and western
Kansas.
Main concern is with precipitation types across the north. Still
appears that the precipitation in our area will hold off until after
midnight, and not reach areas east of I-57 until sunrise. The
remainder of the morning model suite has arrived, and all are
generally trending warmer ahead of the incoming clipper. The NAM
and RAP are most prominent with the 850 mb warm nose, around +4 to
+5C, and suggest all rain even in the far north. The GFS, ECMWF and
Canadian models with a more modest +1 to +3C. These all indicate
surface temperatures above freezing as well, but would indicate a
bit of sleet potential as well. Have leaned a bit more on the warmer
side of the guidance and kept it mostly rain, but included a slight
chance of freezing rain from around Champaign northwest through
Bloomington to Minonk. Surface temperatures will remain borderline
with the ice potential, but lows around 33-34 degrees will be common
in much of the forecast area.
&&
.LONG TERM...(Monday through Sunday)
ISSUED AT 304 PM CST SUN DEC 7 2014
The initial shortwave feature associated with the clipper system
will cross the central IL forecast area by mid afternoon, bringing
the best lift and precipitation with the system. Models over the
past day have trended upward with precipitation amounts and now
yield a consensus of a few hundredths to a tenth of an inch.
Precipitation type could linger as freezing rain from around
Danville northwestward until around 8 a.m. but surface temperatures
will quickly rise above freezing to yield all rain through the day.
Subsidence aloft will follow the initial shortwave causing
precipitation to diminish from west to east late morning through
afternoon. Shallow stratus looks to continue into the evening as
cold advection in northwest winds push into the region. Model
soundings indicate the moisture trapped below a subsidence inversion
will be shallow enough that any precipitation would likely be
drizzle, although some potential for snow flurries with little
accumulation exists.
Below normal temperatures in NW flow will continue for midweek. A
deepening low over the east coast will likely cause a blocked
pattern with a slowly moving ridge over the plains. Models have been
inconsistent with handling next weekend but have trended forecast
toward the ECMWF solution which holds the ridge further west and
looks more reasonable. As a result, will hold drier and slightly
cooler temperatures longer into the weekend.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday night)
ISSUED AT 1105 PM CST SUN DEC 7 2014
Weather system out to our west will track over the forecast area
Monday morning bringing deteriorating conditions with VFR cigs
becoming MVFR and IFR for a time thru the morning hours along with
some light rain at times. Surface trof or wind shift line over the
Missouri River Valley has a band of MVFR and IFR cigs associated
with it as it tracks east late this evening and expect that to
start to affect PIA around 10z and points east by 12z-15z.
Initially, the atmosphere ahead of the trof will be quite dry at
the low levels, but eventually we should see enough saturation for
MVFR/IFR cigs and vsbys along with some scattered areas of rain.
Forecast soundings continue to indicate surface temps will rise
several more degrees ahead of the trof with little if any threat
for freezing precip Monday morning. Once the cigs drop to MVFR/IFR
Monday morning, expect only a gradual improvement to mostly MVFR
Monday afternoon and evening as the trof/wind shift passes to our
east.
Surface winds will be southeast at 8 to 13 kts overnight and then
veer into the southwest and then west early Monday afternoon across
the west and over the remainder of the area after 21z. Look for
northwest winds Monday evening. Wind speeds Monday and Monday
evening will be 10 to 15 kts. We may see some gusts around 20 kts
at times late Monday morning into the afternoon hours.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Smith
SHORT TERM...Geelhart
LONG TERM...Onton
AVIATION...Smith
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1000 PM MST SUN DEC 7 2014
.UPDATE...
ISSUED AT 705 PM MST SUN DEC 7 2014
ADDED PATCHY FOG TO NORTON/GRAHAM COUNTIES THROUGH MIDNIGHT PER
RUC BOUNDARY LAYER RH AND CURRENT NORTON OBSERVATION WHICH IS
REPORTING 5SM IN MIST. AFTER MIDNIGHT 00Z NAM/RUC/HRRR PUSH THE
HIGHER BOUNDARY LAYER RH OUT OF THE FORECAST AREA. ALSO TWEAKED
SKY COVER A BIT TO TRY AND REFLECT APPROACHING THIN LAYER OF
CIRRUS INTO THE AREA LATER TONIGHT.
&&
.SHORT TERM...(THIS AFTERNOON THROUGH MONDAY)
ISSUED AT 212 PM MST SUN DEC 7 2014
LATEST WV IMAGERY AND RAP ANALYSIS SHOW RIDGING BUILDING ACROSS
WESTERN US...WITH TROUGH CENTERED OVER NORTH DAKOTA AND ITS AXIS
EXTENDING ACROSS EASTERN NE/KS INTO THE SOUTHERN PLAINS. AT THE
SURFACE LOW PRESSURE HAS BUILD ACROSS NORTHERN COLORADO WITH A
WEAK SURFACE TROUGH OVER OUR CWA. STRATUS FOG HAS ERODED AND
CLEAR SKIES/DOWNSLOPE FLOW HAS LED TO TEMPS WARMING INTO THE
MIDDLE 60S ACROSS NW KANSAS AND PARTS OF NORTHEAST COLORADO.
SHORTWAVE RIDGE WILL TRANSITION OVER THE CWA TONIGHT AND MONDAY
WITH DRY CONDITIONS AND MILD TEMPS PERSISTING. THERE IS A WEAK
SHORTWAVE THAT MIGHT BRING SLIGHTLY COOLER TEMPS ALOFT AND HIGH
CLOUD COVER MONDAY AFTERNOON...OTHERWISE WE SHOULD SEE LITTLE
CHANGE IN SENSIBLE WEATHER OVER CWA. GOOD RADIATIONAL CONDITIONS
SHOULD BE IN PLACE AND DEPENDING ON HOW LOW THE TD VALUES WILL
DROP WE COULD SEE OVERNIGHT LOWS IN THE UPPER TEENS TO LOWER 20S.
MET GUIDANCE WAS HINTING AT LIGHT FOG DEVELOPMENT...HOWEVER ALL
OTHER 2M AND STATISTICAL GUIDANCE IS NOT SHOWING THIS...AND WITH
DRY AIR ADVECTING FROM THE WEST TO SOUTHWEST I DECIDED AGAINST FOG
MENTION. DESPITE SLIGHTLY COOLER TEMPS ALOFT MONDAY...THE TREND
HAS BEEN FOR MOST GUIDANCE TO HAVE A COOL BIAS WITH GOOD WARMING
OVER THE LAST FEW DAYS. CONSIDERING THESE BIASES I WOULD STILL
EXPECT DAYTIME HIGHS MONDAY TO BE AROUND 60 FOR MOST OF THE
CWA...WHICH IS A LITTLE LOWER THAN WHAT WE SAW TODAY.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 212 PM MST SUN DEC 7 2014
FOR THE EXTENDED PERIOD...BROAD H5 RIDGE WILL BE IN PLACE OVER THE
WESTERN HALF OF THE COUNTRY FOR MUCH OF THE UPCOMING WEEK. BY THE
TIME GOING INTO THE UPCOMING WEEKEND THOUGH...MODELS DO SHIFT THIS
RIDGE MORE EASTWARD AS A TROUGH APPROACHES THE WEST COAST...INTO THE
ROCKIES ON SATURDAY AND THEN OUT OVER THE CENTRAL/SOUTHERN PLAINS BY
NEXT SUNDAY AS A CUTOFF UPPER LOW. THE LATEST GFS/ECMWF RUNS DO
DIFFER ON TRACK AND PLACEMENT OF THIS SYSTEM AND WILL AFFECT
PRECIPITATION POTENTIAL FOR THE FORECAST AREA.
WITH THE LARGE AREA OF HIGH PRESSURE EXPECTED FOR MUCH OF THE
WEEK...THE CWA WILL BE LOOKING AT HIGH TEMPS 10-15 DEGREES ABOVE
NORMAL AND OVERNIGHT LOWS 5-10 DEGREES ABOVE NORMAL. 925MB TEMPS
RANGING FROM +10C TO +15C THRU THE WEEK BEFORE THE TROUGH ARRIVES
SATURDAY NIGHT/SUNDAY...THE AREA WILL SEE HIGHS 55-60F AND OVERNIGHT
LOWS IN THE MID 20S TO LOW 30S.
PRECIPITATION CHANCES FOR THE UPCOMING WEEK WILL BE NEAR ZERO AS A
RESULT OF HIGH PRESSURE OVER THE AREA. THERE IS A WEAK 700 MB
SHORTWAVE MOVING OFF THE ROCKIES TUESDAY NIGHT INTO WEDNESDAY THAT
TRAVERSES THE REGION. MODERATE 1000-500MB RH VALUES WILL ACCOMPANY
THE PASSAGE OF THIS TROUGH...BUT WITH SURFACE HIGH PRESSURE OVER
AREA...LOW LEVEL AIRMASS WILL BE TOO DRY SO HAVE CONTINUED PREVIOUS
FORECAST THINKING OF JUST MID LEVEL CLOUD COVER WITH THIS ONLY. THE
ONLY CHANCE WILL BE OVER THE UPCOMING WEEKEND WITH THE PASSAGE OF
THE UPPER LOW/TROUGH. LATEST GFS HAS THIS SYSTEM COMING OVER THE
AREA OFF THE ROCKIES...WHILE THE ECMWF HAS THIS SYSTEM DROPPING
OVER TEXAS. THIS WILL ALLOW FOR SYSTEM TO GRAB AMPLE MOISTURE TO
PRODUCE SOME PRECIP...WHILE THE GFS IS ALMOST DRY. WHILE THE BULK OF
THE ECMWF SCENARIO WILL REMAIN SOUTH OF THE CWA...STILL THINK SOME
OF THIS WILL IMPACT THE CWA SO HAVE KEPT IN UP TO CHANCE POPS FOR
LIGHT RAIN/SNOW. LOOKING FOR ANY LIGHT SNOW AT NIGHT SATURDAY INTO
SUNDAY MORNING...AND ANY LIGHT RAIN DURING THE DAY. THE CWA AFFECTED
WITH ANY OVERNIGHT LIGHT SNOW SHOULD BE LIGHT ON THE ORDER OF A
COUPLE TENTHS RIGHT NOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1000 PM MST SUN DEC 7 2014
FOR KGLD AND KMCK...VFR THROUGH THE PERIOD. LIGHT NORTH-NORTHWEST
WINDS AT TAF ISSUANCE FORECAST TO BACK TO THE SOUTHWEST AROUND
07KTS AROUND 16Z THEN BECOME LIGHT/VARIABLE FROM 19Z-22Z BEFORE
SHIFTING TO THE NORTHWEST/NORTHEAST AROUND 05Z FROM 23Z THROUGH
THE REST OF THE TAF PERIOD. FAIR WEATHER CU POSSIBLE AFTER 19Z
OTHERWISE AN INCREASE IN HIGH CLOUDS MOVING IN FROM THE
NORTHWEST FROM 19Z THROUGH 03Z OR SO BEFORE EXITING TO THE EAST.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...99
SHORT TERM...DR
LONG TERM...JN
AVIATION...99
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
342 AM EST MON DEC 8 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 1210 AM EST MON DEC 8 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A WELL-DEFINED SHORTWAVE
MOVING ACROSS ND THIS AFTERNOON WHICH WILL BE THE FEATURE OF
INTEREST IN THE SHORT TERM AS IT SHIFTS E ACROSS THE UPPER GREAT
LAKES MON. AT THE SFC...THE SHORTWAVE SUPPORTED LOW PRES OVER NCNTRL
ND. TO THE E...HIGH PRES HAS SLIPPED INTO WRN QUEBEC. STRONG
WAA/ISENTROPIC ASCENT REGIME BETWEEN THE APPROACHING SHORTWAVE AND
DEPARTED HIGH PRES HAS LED TO MID-LVL CLOUDS ACROSS MUCH OF THE
MIDWEST AND UPPER GREAT LAKES. RADARS ARE ALSO SHOWING RETURNS
UPSTREAM OVER MN AND NW WI...BUT SO FAR...ONLY NRN MN OBS WERE
REPORTING PCPN AT THE SFC.
TONIGHT...IN ADVANCE OF APPROACHING SHORTWAVE...MODELS
INDICATE RIBBON OF 850-700MB MOISTURE TRANSPORT IN CONCERT WITH
ISENTROPIC ASCENT ENHANCED BY 850MB WINDS OF 40-50KT AND DEEP LAYER
QVECTOR CONVERGENCE SPREADING W-E ACROSS THE FCST AREA TONIGHT.
CONSEQUENTLY...CATEGORICAL POPS STILL APPEAR ON TRACK...SPREADING
INTO WRN UPPER MI THIS EVENING AND INTO THE CNTRL OVERNIGHT. SNOW
MAY NOT REACH THE FAR E AROUND KERY UNTIL CLOSER TO 12Z. AVERAGED
MODEL QPF INDICATES 0.1 TO 0.2 INCHES OF QPF TONIGHT OVER WEST AND
CENTRAL UPPER MI...SUGGESTING 1-2 INCHES OF SNOW IN GENERAL AS SNOW
TO WATER RATIOS SHOULDN`T BE MUCH MORE THAN 10-12 TO 1. THESE
NUMBERS APPEAR ON TRACK FROM AN ISENTROPIC STANDPOINT AS MIXING
RATIOS OF 2-3G/KG ARE AVBL WITH CLOSE TO 3-6HRS OF ASCENT. SNOW
ACCUMULATIONS WILL BE LIGHTEST OVER THE E SINCE SNOW DOESN`T BEGIN
UNTIL NEAR THE END OF THE TONIGHT PERIOD. CLOUDS/PCPN/WINDS WILL
KEEP TEMPS FROM FALLING MORE THAN ROUGHLY 2-4 DEGREES FROM TODAYS
HIGH TEMPS.
MONDAY...MODERATE TO STRONG ISENTROPIC ASCENT WILL CONTINUE OVER THE
FAR ERN CWA FOR THE FIRST FEW HOURS OF THE MORNING BEFORE
TRANSITIONING TO WEAK ISENTROPIC ASCENT IN THE AFTERNOON. THIS
SHOULD LEAD TO AN ADDITIONAL 1.5-2 INCHES OF ACCUMULATION FOR ERN
ALGER...SCHOOLCRAFT AND LUCE COUNTIES. TRANSITION TO ISENTROPIC
DESCENT ACROSS MUCH OF THE WEST HALF OF THE CWA SHOULD RESULT IN SCT
LIGHT SHSN WITH ADDITIONAL ACCUMULATION AROUND HALF AN INCH. TOTAL
SNOW ACCUMULATION OVER THE FAR ERN CWA SHOULD REMAIN BLO ADVISORY
CRITERIA OF 3"/12 HRS SO WINTER WX ADVISORIES SHOULD NOT BE NEEDED.
EXPECT HIGHS IN THE LOWER TO MID 30S.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 340 AM EST MON DEC 8 2014
SHARP UPPER TROUGH WILL BE E OF THE CWA BY 12Z TUE AS A 1034MB SFC
RIDGE IS JUST W OF THE CWA. WINDS WILL START THE DAY TUE OUT OF THE
N WITH 850MB TEMPS AROUND -8C...WHICH IS NOT COLD ENOUGH FOR PURE
LES. HAVE QUICKLY DIMINISHING POPS ON TUE AS UPSLOPE PRECIP WILL
DIMINISH AS THE SFC RIDGE MOVES IN. DO NOT EXPECT MORE THAT A HALF
INCH OF ADDITIONAL SNOW ON TUE.
TUE NIGHT THROUGH SAT WILL SEE AN UPPER RIDGE BUILDING INTO THE
REGION...WHICH WILL LEAD TO MOSTLY DRY AND WARMER TEMPERATURES.
SHOULD STILL SEE COLD NIGHTS TUE NIGHT AND WED NIGHT AS LOWS
APPROACH 0F...ESPECIALLY WED NIGHT. HIGH TEMPS WILL BE WARMEST FRI
AND SAT /ESPECIALLY SAT/ AND WILL BE IN THE LOW 40S IN PLACES BOTH
DAYS. MODELS HAVE BEEN HINTING AT A SHORTWAVE MOVING INTO THE REGION
ON SAT. WHILE THIS IS NOT CERTAIN BY ANY MEANS...DID SHOW A SUBTLE
INCREASE IN POPS ON SUN. ALSO...KEPT FOG IN THE FORECAST FOR SAT
NIGHT AND SUN AS HIGHER DEW POINTS SPREAD INTO THE AREA OVER A
SLOWLY MELTING SNOW PACK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1210 AM EST MON DEC 8 2014
SNOW AHEAD OF AN APPROACHING LOW PRES SYSTEM WILL MOVE THROUGH THE
WEST HALF OF UPPER MI OVERNIGHT. ALL TERMINALS ARE EXPECTED TO FALL
TO MVFR. WITH A BRIEF PERIOD OF SOMEWHAT HEAVIER SNOW...THERE SHOULD
ALSO BE A PERIOD OF IFR VIS. LOOK FOR ALL SITES TO LOWER TO IFR CIGS
THIS MORNING AS LOW-LVL MOISTURE GETS TRAPPED UNDER A LOWERING
INVERSION. THE IFR CIGS SHOULD PERSIST THROUGH THE AFTERNOON. AS
WINDS VEER TO THE NW BEHIND THE LOW...SOME LAKE AND UPSLOPE ENHANCED
SNOW WILL BE POSSIBLE...MAINLY AT IWD/CMX. OTHERWISE...PERSISTENT LOW
LEVEL MOISTURE WILL MAINTAIN THE IFR CIGS THROUGH THE EVENING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 338 PM EST SUN DEC 7 2014
TIGHTENING PRES GRADIENT AND PRES FALLS SHIFTING INTO THE UPPER
LAKES AHEAD OF AN APPROACHING LOW PRES WILL RESULT IN SOUTHERLY
GALES TONIGHT INTO MONDAY MORNING OVER THE EAST HALF OF LAKE
SUPERIOR. WINDS OVER THE W WL STAY MOSTLY BLO 30KT. AS LOW PRES/COLD
FRONT MOVE ACROSS THE UPPER LAKES LATE MON/MON EVENING...WINDS WILL
SHIFT TO THE NW-N. WITH SYSTEM TRENDING WEAKER AS IT
DEPARTS...EXPECT WINDS TO STAY BLO GALES MON NIGHT INTO TUE...NO
HIGHER THAN 30KT MAINLY CENTRAL AND EAST. HIGH PRES RIDGE ARRIVING
TUE NIGHT/WED MAY LINGER INTO THE END OF THE WEEK AND RESULT IN
WINDS UNDER 20KT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 10 AM EST THIS MORNING FOR LSZ266-267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...TITUS
AVIATION...JLB
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1213 AM EST MON DEC 8 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 1210 AM EST MON DEC 8 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A WELL-DEFINED SHORTWAVE
MOVING ACROSS ND THIS AFTERNOON WHICH WILL BE THE FEATURE OF
INTEREST IN THE SHORT TERM AS IT SHIFTS E ACROSS THE UPPER GREAT
LAKES MON. AT THE SFC...THE SHORTWAVE SUPPORTED LOW PRES OVER NCNTRL
ND. TO THE E...HIGH PRES HAS SLIPPED INTO WRN QUEBEC. STRONG
WAA/ISENTROPIC ASCENT REGIME BETWEEN THE APPROACHING SHORTWAVE AND
DEPARTED HIGH PRES HAS LED TO MID-LVL CLOUDS ACROSS MUCH OF THE
MIDWEST AND UPPER GREAT LAKES. RADARS ARE ALSO SHOWING RETURNS
UPSTREAM OVER MN AND NW WI...BUT SO FAR...ONLY NRN MN OBS WERE
REPORTING PCPN AT THE SFC.
TONIGHT...IN ADVANCE OF APPROACHING SHORTWAVE...MODELS
INDICATE RIBBON OF 850-700MB MOISTURE TRANSPORT IN CONCERT WITH
ISENTROPIC ASCENT ENHANCED BY 850MB WINDS OF 40-50KT AND DEEP LAYER
QVECTOR CONVERGENCE SPREADING W-E ACROSS THE FCST AREA TONIGHT.
CONSEQUENTLY...CATEGORICAL POPS STILL APPEAR ON TRACK...SPREADING
INTO WRN UPPER MI THIS EVENING AND INTO THE CNTRL OVERNIGHT. SNOW
MAY NOT REACH THE FAR E AROUND KERY UNTIL CLOSER TO 12Z. AVERAGED
MODEL QPF INDICATES 0.1 TO 0.2 INCHES OF QPF TONIGHT OVER WEST AND
CENTRAL UPPER MI...SUGGESTING 1-2 INCHES OF SNOW IN GENERAL AS SNOW
TO WATER RATIOS SHOULDN`T BE MUCH MORE THAN 10-12 TO 1. THESE
NUMBERS APPEAR ON TRACK FROM AN ISENTROPIC STANDPOINT AS MIXING
RATIOS OF 2-3G/KG ARE AVBL WITH CLOSE TO 3-6HRS OF ASCENT. SNOW
ACCUMULATIONS WILL BE LIGHTEST OVER THE E SINCE SNOW DOESN`T BEGIN
UNTIL NEAR THE END OF THE TONIGHT PERIOD. CLOUDS/PCPN/WINDS WILL
KEEP TEMPS FROM FALLING MORE THAN ROUGHLY 2-4 DEGREES FROM TODAYS
HIGH TEMPS.
MONDAY...MODERATE TO STRONG ISENTROPIC ASCENT WILL CONTINUE OVER THE
FAR ERN CWA FOR THE FIRST FEW HOURS OF THE MORNING BEFORE
TRANSITIONING TO WEAK ISENTROPIC ASCENT IN THE AFTERNOON. THIS
SHOULD LEAD TO AN ADDITIONAL 1.5-2 INCHES OF ACCUMULATION FOR ERN
ALGER...SCHOOLCRAFT AND LUCE COUNTIES. TRANSITION TO ISENTROPIC
DESCENT ACROSS MUCH OF THE WEST HALF OF THE CWA SHOULD RESULT IN SCT
LIGHT SHSN WITH ADDITIONAL ACCUMULATION AROUND HALF AN INCH. TOTAL
SNOW ACCUMULATION OVER THE FAR ERN CWA SHOULD REMAIN BLO ADVISORY
CRITERIA OF 3"/12 HRS SO WINTER WX ADVISORIES SHOULD NOT BE NEEDED.
EXPECT HIGHS IN THE LOWER TO MID 30S.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 323 PM EST SUN DEC 7 2014
GOOD AGREEMENT IN LARGER SCALE PATTERN THROUGH THE LENGTH OF THE
LONG TERM INTO NEXT WEEKEND. LOW PRESSURE THAT CROSSES THE AREA ON
MONDAY WILL BE WEAKENING AS IS SLIDES EAST OF LK SUPERIOR BY TUESDAY
MORNING. NNW FLOW LAKE ENHANCEMENT...AT LEAST IN DIMINISHING
STATE...EXPECTED MONDAY EVENING OVER WESTERN UPR MICHIGAN...ESPECIALLY
OVER THE KEWEENAW WHERE DEEPER MOISTURE TO H7 LINGERS AND H85 TEMPS
DROP TO AROUND -8C. LOW-LEVEL WINDS NOT TOO CYCLONIC SO CONVERGENCE
WILL BE WEAK. SNOW ACCUMS MONDAY EVENING SHOULD BE NOTHING MORE THAN
A COUPLE INCHES FOR NW CWA. DEPARTING DEEP MOISTURE AND LIMITED COLD
AIR /H9-H85 TEMPS -8C TO -10C/ IS MARGINAL FOR PURE LAKE EFFECT...SO
SNOW SHOWERS SHOULD DIMINISH SHARPLY AFTER MIDNIGHT ALL CWA. LIGHT
LES COULD CONTINUE INTO TUESDAY MORNING...BUT CONTINUED DRYING AND
SFC RIDGING WILL SPELL AN END TO LES TUE AFTN.
BEYOND MONDAY NIGHT...APPEARS QUIET WITH NO BIG STORMS OVER THE
UPPER GREAT LAKES. UPPER LEVEL FLOW FEATURES RIDGING BUILDING OVER
THE MID PORTION OF THE CONUS MID TO LATE WEEK. MEANWHILE...DEEPENING
TROUGH OVER THE EASTERN CONUS WILL RESULT IN STRONG EAST COAST STORM
THAT WILL BRING HEAVY SNOW TO INTERIOR PORTIONS OF THE NORTHEAST AND
NEW ENGLAND. THE BUILDING UPR RIDGE WILL LEAD TO SPRAWLING SFC RIDGE
FM CENTRAL PLAINS AND NORTHERN ONTARIO ON TUESDAY ONLY MOVING SLOWLY
TO NORTHERN QUEBEC TO LOWER MISSISSIPPI RIVER VALLEY BY FRIDAY.
COULD BE A COUPLE CHILLY NIGHTS INLAND ON TUESDAY NIGHT AND
WEDNESDAY NIGHT WITH THE RIDGE OVERHEAD AND AS PWATS ARE BLO 75 PCT
OF NORMAL. DEPENDING ON CLOUD COVER...MINS EITHER NIGHT MAY FALL
TOWARD ZERO. FOR NOW HAVE SOME SINGLE DIGITS ABOVE ZERO IN THERE
UNTIL CAN GET BETTER HANDLE ON EXTENT OF MID CLOUDS.
BY NEXT WEEKEND UPPER LEVEL RIDGE AXIS IS OVER THE WESTERN GREAT
LAKES. SW FLOW SFC-H85 WILL TRANSPORT HIGHER DWPNTS FM THE CNTRL
PLAINS INTO THE GREAT LAKES. YET IT IS NOT UNTIL SATURDAY NIGHT INTO
SUNDAY THAT SFC DWPNTS ARE FORECAST TO BE OVER 32F. SOUNDINGS FM GFS
INDICATE SHALLOWER MOISTURE THAN THEY SHOWED YDY FOR FRIDAY AND
SATURDAY...SO COULD HAVE AT LEAST SOME SUNSHINE WHICH WOULD ALLOW
TEMPS TO WARM INTO THE MID 30S TO LOWER 40S. SHOT UP SLIGHTLY HIGHER
THAN BLENDED GUIDANCE. ONCE DWPNTS RISE ABOVE FREEZING SATURDAY
NIGHT INTO SUNDAY...THERE WILL BE INCREASING PROSPECTS OF DRIZZLE
AND FOG AS THIS MOISTURE RIDES OVER GRADUAL MELTING SNOWPACK. ECMWF
AND GFS ALSO INDICATE MOISTURE DEPTH INCREASES WITH SOME WEAK LIFT
DEVELOPING DUE TO SHORTWAVE ENERGY WORKING OVER THE AREA OUT AHEAD
OF TROUGH AXIS OVER WESTERN CONUS. WILL HAVE SMALL POPS IN THERE FOR
RAIN LATE IN THE WEEKEND. ALSO WILL INCLUDE MENTION OF FOG SINCE
DWPNTS ARE FORECAST IN THE MID-UPR 30S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1210 AM EST MON DEC 8 2014
SNOW AHEAD OF AN APPROACHING LOW PRES SYSTEM WILL MOVE THROUGH THE
WEST HALF OF UPPER MI OVERNIGHT. ALL TERMINALS ARE EXPECTED TO FALL
TO MVFR. WITH A BRIEF PERIOD OF SOMEWHAT HEAVIER SNOW...THERE SHOULD
ALSO BE A PERIOD OF IFR VIS. LOOK FOR ALL SITES TO LOWER TO IFR CIGS
THIS MORNING AS LOW-LVL MOISTURE GETS TRAPPED UNDER A LOWERING
INVERSION. THE IFR CIGS SHOULD PERSIST THROUGH THE AFTERNOON. AS
WINDS VEER TO THE NW BEHIND THE LOW...SOME LAKE AND UPSLOPE ENHANCED
SNOW WILL BE POSSIBLE...MAINLY AT IWD/CMX. OTHERWISE...PERSISTENT LOW
LEVEL MOISTURE WILL MAINTAIN THE IFR CIGS THROUGH THE EVENING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 338 PM EST SUN DEC 7 2014
TIGHTENING PRES GRADIENT AND PRES FALLS SHIFTING INTO THE UPPER
LAKES AHEAD OF AN APPROACHING LOW PRES WILL RESULT IN SOUTHERLY
GALES TONIGHT INTO MONDAY MORNING OVER THE EAST HALF OF LAKE
SUPERIOR. WINDS OVER THE W WL STAY MOSTLY BLO 30KT. AS LOW PRES/COLD
FRONT MOVE ACROSS THE UPPER LAKES LATE MON/MON EVENING...WINDS WILL
SHIFT TO THE NW-N. WITH SYSTEM TRENDING WEAKER AS IT
DEPARTS...EXPECT WINDS TO STAY BLO GALES MON NIGHT INTO TUE...NO
HIGHER THAN 30KT MAINLY CENTRAL AND EAST. HIGH PRES RIDGE ARRIVING
TUE NIGHT/WED MAY LINGER INTO THE END OF THE WEEK AND RESULT IN
WINDS UNDER 20KT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 10 AM EST THIS MORNING FOR LSZ266-267.
GALE WARNING UNTIL 3 AM EST EARLY THIS MORNING FOR LSZ248>250-
265.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...JLA
AVIATION...JLB
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
334 AM CST MON DEC 8 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 329 AM CST MON DEC 8 2014
CURRENT CONDITIONS SYNOPSIS...
LATEST SURFACE ANALYSIS SHOWS LOW PRESSURE NORTHWEST OF
INTERNATIONAL FALLS... WITH A COLD FRONT TRAILING SOUTH THROUGH
SOUTHWEST MINNESOTA. WATER VAPOR IMAGERY AND RAP UPPER AIR ANALYSIS
SHOW AN INITIAL SHORTWAVE PUSHING THROUGH EASTERN MINNESOTA AT THE
CURRENT TIME... WITH A SECONDARY WAVE DROPPING INTO EASTERN NORTH
DAKOTA. THIS SECOND WAVE WILL HELP PUSH THE AFOREMENTIONED SURFACE
LOW AND FRONTAL BOUNDARY EAST ACROSS THE AREA THIS MORNING... WITH
THE FRONT QUICKLY WORKING THROUGH WISCONSIN BY AFTERNOON. EXTENSIVE
LOW CLOUDS WERE PRESENT ACROSS THE STATE... WITH LAYERED CLOUDS
ASSOCIATED WITH THE UPPER WAVE HELPING TO PRODUCE SOMEWHAT MORE
MEANINGFUL RETURNS ON RADAR NORTH OF I-94 WHERE SOME LIGHT
ACCUMULATING SNOW HAS OCCURRED. LOW CLOUDS EXTEND WELL UPSTREAM
THROUGH NORTH DAKOTA AND INTO MANITOBA AND SASKATCHEWAN.
FORECAST ITEM/S/ OF CONCERN...
LINGERING LIGHT PCPN IS THE PRIMARY FORECAST CONCERN. SOME MIXED
PCPN CONTINUES ACROSS THE AREA GIVEN THE LACK OF SATURATION AND
PRESENCE OF ONLY LIQUID WATER WITHIN CLOUDS OVER MUCH OF THE CENTRAL
AND SOUTHERN PORTION OF THE AREA. THIS IS RESULTING IN SOME
MIST/DRIZZLE... WHICH IS LEADING TO SOME LIGHT ICING IN LOCATIONS
WHERE TEMPERATURES ARE BELOW FREEZING OR WHERE UNTREATED GROUND
TEMPERATURES ARE SUB-FREEZING. THE DEEPER MOISTURE AND LAYERED
CLOUDS OVER THE NORTHERN PART OF THE AREA ARE HELPING TO SEED THINGS
WITH ICE CRYSTALS AND ALLOWING FOR MORE IN THE WAY OF LIGHT SNOWFALL
ACROSS THE NORTHERN PART OF THE AREA. HOWEVER... THE BEST FORCING
ASSOCIATED WITH THE UPPER WAVE CONTINUES TO PUSH EAST... SO ANY
LINGERING PCPN TODAY WILL MAINLY BE DRIVEN BY LOW LEVEL CYCLONIC
FLOW AND A FAIRLY SHALLOW DEPTH OF LIFT. PCPN TYPE COULD REMAIN AN
ISSUE... ALTHOUGH THE NAM AND GFS SUGGEST WE SHOULD HAVE JUST ENOUGH
DEPTH OF MOISTURE THROUGH THE DAY FOR ANY PCPN TO BE MAINLY SNOW
GIVEN THE COLDER TEMPERATURES MOVING IN ALOFT. LOOKING UPSTREAM
THERE IS MINIMAL PCPN BEING REPORTED IN THE STRATOCU AREA... WITH
PCPN MAINLY BENEATH THE UPPER COLD POOL.
MODEL DISCUSSION/PREFERENCES...
DO NOT HAVE A STRONG PREFERENCE FOR ANY PARTICULAR SOLUTION IN THE
SHORT TERM... SO STUCK WITH A COMPROMISE OF HRRR... NAM... RAP...
AND HOPWRF SOLUTIONS. THESE ALL POINT TOWARD MAINLY CLOUDY SKIES
TODAY AND TONIGHT... WITH DRIER AIR TRYING TO WORK IN TOWARD THE END
OF THAT PERIOD TO SCOUR OUT THE LOWER CLOUDS.
SENSIBLE WEATHER EXPECTATIONS...
THE BULK OF THE PCPN SHOULD CONTINUE TO SHIFT EAST TODAY AS THE
INITIAL SHORTWAVE EXITS AND THE SECONDARY WAVE QUICKLY ROTATES
THROUGH THE AREA. HOWEVER... CYCLONIC BOUNDARY LAYER FLOW AND THE
PRESENCE OF THE UPPER TROUGH SHOULD KEEP SOME CHANCE OF PCPN GOING
FOR MUCH OF THE DAY OVER THE NORTHERN AND EASTERN PORTION OF THE
AREA. CAN/T RULE OUT SOME ADDITIONAL LIGHT MIXED PCPN... ALTHOUGH
THE GENERAL TENDENCY SHOULD BE FOR MORE IN THE WAY OF SNOWFLAKES
THAN ANYTHING ELSE WHERE PCPN OCCURS.
DETAILED DISCUSSION FOR ITEM/S/ OF CONCERN...
VERTICAL PROFILES WILL DETERMINE PCPN TYPE THROUGH THE DAY TODAY...
AND FORECAST SOUNDINGS SUGGEST SOME CHANCE FOR FZDZ OR LIGHT
FREEZING RAIN AT TIMES WITH DRIER AIR IN THE MID-LEVELS AND A LOSS
OF ICE CRYSTALS. HOWEVER... PCPN WILL CONTINUE TO BE ON THE
DOWNSWING... SO ANY ADDITIONAL ACTIVITY SHOULD BE LIMITED IN ITS
OCCURRENCE. HIGH PRESSURE WILL BUILD IN FROM THE NORTHWEST
TONIGHT... WORKING TO BRING ANY LINGERING PCPN TO AN END AS
SUBSIDENCE FINALLY WORKS TO SCOUR OUT THE CLOUD COVER FROM WEST TO
EAST.
FORECAST CONFIDENCE/UNCERTAINTY...
CONFIDENCE IS MODERATE TO HIGH IN THE PRESENCE OF CLOUDY SKIES TODAY
INTO THIS EVENING... WITH LOW TO MODERATE CONFIDENCE THAT CLOUDS
WILL BREAK UP LATER TONIGHT. THERE IS MODERATE TO HIGH CONFIDENCE
THAT LIGHT PCPN WILL CONTINUE TO IMPACT THE NORTHEAST AND EASTERN
PORTION OF THE AREA INTO THIS AFTERNOON... WITH CONFIDENCE OF PCPN
OCCURRENCE DECREASING TO THE SOUTH AND WEST. THERE IS LOW CONFIDENCE
IN THE EXACT TIMING AND LOCATION OF ADDITIONAL MIXED PCPN IN THE
FORM OF FREEZING DRIZZLE.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 329 AM CST MON DEC 8 2014
BIGGEST QUESTION DURING THE LONG TERM STILL REVOLVES AROUND HOW WARM
CAN WE GET FRIDAY AND SATURDAY...WHICH REALLY MEANS THAT QUESTION IS
HOW MUCH STRATUS DO WE SEE THEN. NO MAJOR PRECIP MAKERS LOOK TO
IMPACT THE AREA...WITH ONLY SOME LIGHT RAIN EXPECTED WITH A COLD
FRONT PASSING THROUGH THE AREA FOR THE SECOND HALF OF THE WEEKEND.
MEDIUM RANGE MODELS CONTINUE TO SHOW A SIGNIFICANT PATTERN SHIFT
COMMENCING THIS WEEK...AS THE DEEP UPPER LOWS AND ASSOCIATED ARCTIC
AIRMASSES SHIFT TO THE EAST BY ABOUT 60 DEGS OF LONGITUDE. THIS WILL
PUSH THE ARCTIC OFF INTO THE NORTH ATLANTIC AND EASTERN ASIA...WITH
MUCH OF THE NORTH AMERICAN LAND MASS REMAINING ARCTIC AIRMASS
FREE...WITH ABOUT THE ONLY COLD AIR OVER THE CONUS BY THE WEEKEND
BEING FOUND UNDER THE UPPER LOW THAT WILL BE CLOSING OFF OVER THE
EAST COAST BY THE END OF THE WEEK.
THE LONG TERM WILL START WITH A MOISTURE STARVED UPPER LOW WORKING
FROM NODAK INTO CENTRAL IOWA TUESDAY INTO TUESDAY NIGHT. AT THE
SFC... A BETTER THAN 1032MB SW-NE ORIENTED RIDGE WILL BE WORKING
ACROSS THE UPPER MS VALLEY...HENCE WHY THE UPPER WAVE IS MOISTURE
STARVED IN THE LOW LEVELS. TUESDAY WILL BE THE COLDEST DAY OF THE
WEEK BY FAR...WITH TEMPERATURES REMAINING IN THE 20S...BUT TUESDAY
NIGHT...WE GET ON THE BACKSIDE OF THE HIGH...WITH SRLY FLOW SETTING
UP FROM WEDNESDAY INTO SUNDAY. AS THESE SRLY WINDS BLOW...AN
IMPRESSIVE H5 RIDGE WILL BE BUILDING INTO THE UPPER MS VALLEY. BY
SATURDAY ALL MED RANGE MODELS SHOW H5 HEIGHTS EXCEEDING 570
DM...WHICH WOULD BE SOME OF THE HIGHEST H5 HEIGHTS EVER OBSERVED IN
THE MONTH OF DECEMBER IN THE COMBINED STC/MPX SOUNDING
HISTORY...WHICH DATES BACK TO 1948. TO GO WITH THAT...THE ECMWF
CONTINUES TO SHOW H85 TEMPS FRIDAY/SATURDAY BUILDING TO BETWEEN +12C
AND +16C. LIKE THE H5 HEIGHTS...H85 TEMPS THIS HIGH ARE BASICALLY AT
THE OBSERVED MAX IN DECEMBER FOR STC/MPX.
TO GO ALONG WITH THESE IMPRESSIVE H5 HEIGHTS AND H85 TEMPS...WE WILL
BE SEEING OUR DEWP TEMPS SURGE INTO AT LEAST THE 40S...WITH THE
ECMWF ACTUALLY BRINGING 50 DEGREE DEWPS ALL THE WAY UP TO I-94 ON
SATURDAY. EVEN IF WE ONLY SEE DEWPS IN THE MID 40S...THAT WOULD BE
ABOUT 15 DEGREES HIGHER THAN THE NORMAL HIGH. THE MAJORITY OF THE
TIME WHEN DEWPS IN THE WINTER EXCEED THE NORMAL HIGHS BY THAT MUCH
IT MEANS A DAY FULL OF FOG AND STRATUS...AND THAT CERTAINLY LOOKS TO
BE THE CASE ON SATURDAY. FRIDAY MAY AVOID THE STRATUS AND GO ABOUT
MOSTLY SUNNY...BUT SATURDAY NIGHT...WHEN THE 40+ DEWPS GET
HERE...THEY LOOK TO COME WITH PLENTY OF LOW STRATUS. WHAT DOES ALL
THAT MEAN...WELL IT WILL PROBABLY BE TOUGH TO REACH RECORD HIGH MAX
TEMPS /51 TO 53/...BUT WE SHOULD HAVE NO PROBABLY SETTING SOME NEW
RECORD WARM MINIMUMS OVER THE WEEKEND. SUNDAY...A COLD FRONT WILL
WORK ACROSS THE MPX AREA...BUT LOOKS TO COME THROUGH LATE ENOUGH TO
GIVE ALL BE WRN MN ONE MORE DAY WITH HIGHS IN THE 40S BEFORE
TEMPERATURES COOL BACK CLOSER TO NORMAL.
FOR PRECIP...THE ATMO LOOKS TO REMAIN TOO DRY FOR ANYTHING UNTIL THE
COLD FROM STARTS MOVING INTO WRN MN SATURDAY NIGHT. MOISTURE
TRANSPORT AND ISENTROPIC ASCENT AHEAD OF THE FRONT LOOK TO BE ENOUGH
TO GENERATE SOME LIGHT PRECIP. GFS FORECAST SOUNDINGS WOULD SAY WE
LACK ICE CRYSTALS...WITH PRIMARY TYPE BE DZ THROUGH THE
WEEKEND...THOUGH WITH TEMPERATURES AS WARM AS THEY ARE FORECAST TO
BE...P-TYPE LIKELY WILL NOT BE MUCH OF AN ISSUE...IT WILL BE ALL
DZ/RA UNTIL AFTER THE COLD FRONT PASSES.
ALTHOUGH IT DOES COOL DOWN BEHIND THE FRONT...BOTH THE GFS/ECMWF ARE
IN GOOD AGREEMENT WITH THE DOOR TO THE ARCTIC REMAINING FIRMLY SHUT
FOR US FOR THE NEXT 10 DAYS...WITH THE FIRST HALF OF DECEMBER
LOOKING TO START OFF ON A VERY MILD NOTE AFTER A VERY COLD DAY 1.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1151 PM CST SUN DEC 7 2014
IFR/LIFR CONDITIONS JUST AHEAD OF THE COLD FRONT LOCATED FROM AXN TO
RWF AT TAF ISSUANCE TIME WILL CONTINUE PUSHING EAST OVERNIGHT. A
PERIOD OF VFR CONDITIONS BEHIND OF THE FRONT WILL GRADUALLY FILL IN
WITH MVFR CIGS WITHIN ABOUT 3 HOURS FOLLOWING THE FROPA...AND THEY
WILL LIKELY PERSIST INTO MONDAY EVENING.
KMSP...IFR CONDITIONS EXPECTED FOR THE NEXT SEVERAL HOURS UNTIL
THE FROPA. MAY BRIEFLY GET DOWN TO LIFR CONDITIONS...BUT FOLLOWING
THE FROPA SOME IMPROVEMENT CAN BE EXPECTED AND COULD SEE A FEW
HOURS OF VFR BEFORE MVFR CIGS RETURN FOR MOST OF THE REST OF THE
PERIOD.
/OUTLOOK FOR KMSP/
TUE...VFR. LIGHT/VAR WINDS.
WED...VFR. WINDS SSE 5-10 KT.
THU...VFR. WINDS S 5 KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...
LONG TERM...MPG
AVIATION...BORGHOFF
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
1043 PM MST SUN DEC 7 2014
.AVIATION...
06Z TAF CYCLE
CONCERN REMAINS REGARDING LOW CLOUD AND FOG DEVELOPMENT ACROSS THE
NW/WC VALLEYS AS WELL AS THE PECOS RIVER VALLEY OVERNIGHT.
TEMP/DEWPT SPREADS ARE GENERALLY 2 DEG OR LESS ACROSS THE NW...BUT
MUCH THICKER HIGH CLOUDS WILL BE MOVING IN SHORTLY. THUS...THIS IS
NOT THE IDEAL SITUATION FOR LOW CLOUD AND/OR FOG DEVELOPMENT...BUT
QUITE A BIT OF THIS HAS ALREADY BEEN NOTED IN AZ. WITH CONFIDENCE
SHAKY...HAVE OPTED TO GO WITH A VCFG AT KFMN. MEANWHILE...LIFR
CIGS/VSBY ARE ONGOING AT KHOB...AND MOST HI-RES MODELS SHOW THESE
CONDITIONS EXPANDING UP THE PECOS VALLEY TOWARD KROW...BEFORE THE
BULK OF THE HIGH CLOUDS ARRIVE. THEREFORE CONFIDENCE IS HIGHER
THAT LOW CLOUDS/FOG WILL OCCUR AT KROW. THE HIGH CLOUDINESS WILL
STICK AROUND THRU MONDAY...BUT THE LOW CLOUDS SHOULD DISSIPATE BY
18Z. HOWEVER...THE LOW CLOUDS MAY REDEVELOP MONDAY NIGHT SE OF A
LINE FROM KTCC TO KROW.
34
&&
.PREV DISCUSSION...1013 PM MST SUN DEC 7 2014...
.UPDATE...
ADDED SOME PATCHY FOG TO NORTHWEST AND WEST CENTRAL NM FOR TONIGHT
ALTHOUGH CONFIDENCE NOT GREAT. LATEST RUC INDICATES DEWPOINTS TO
FALL SOMEWHAT AS TEMPERATURES CONTINUE TO COOL...AND A PERSISTENT
PATCH OF HIGH RH VALUES DEPICTED FROM THE FOUR CORNERS SOUTHEASTWARD
TOWARDS THE CUBA AREA. THERE IS ALSO A SLIVER OF MOISTURE SHOWN
WORKING UP THE PECOS VALLEY THROUGH KROW...SO INCREASED CLOUD
COVER THERE. TWEAKED A FEW OVERNIGHT LOW TEMPERATURES AS WELL.
UPDATED ZFP JUST TRANSMITTED.
&&
.PREV DISCUSSION...328 PM MST SUN DEC 7 2014...
.SYNOPSIS...
THE RECENT WARMING AND DRYING TREND WILL CONTINUE THROUGH MONDAY.
THEN...A WEAK UPPER LEVEL TROUGH CROSSING FROM THE UPPER BAJA
PENINSULA WILL BRING A CHANCE FOR SHOWERS MAINLY TO LOCATIONS
SOUTH OF INTERSTATE 40 TUESDAY THROUGH WEDNESDAY. AFTER ANOTHER
WARMER AND DRIER PERIOD DURING THE LATTER HALF OF THE WORK
WEEK...A STRONGER AND COLDER SYSTEM IS FORECAST TO CROSS SLOWLY
FROM THE WEST NORTHWEST WITH WIDESPREAD PRECIPITATION THIS WEEKEND.
&&
.DISCUSSION...
DESPITE A RIDGE OF HIGH PRESSURE THAT WILL ARRIVE OVERHEAD FROM
THE WEST...ABUNDANT HIGH CLOUDS WILL MOVE OVER CENTRAL AND
ESPECIALLY WESTERN AREAS FROM THE WEST TONIGHT. MODEL SURFACE RH
PROGS SUGGEST THERE IS ENOUGH MOISTURE FOR A RETURN OF LOW CLOUDS
AND POSSIBLY PATCHY FOG TO PARTS OF THE NORTHWEST AND WEST CENTRAL
PLATEAU...BUT THE HIGH CLOUDS ARE CURRENTLY EXPECTED TO INHIBIT
RADIATIONAL COOLING ENOUGH TO PREVENT SIGNIFICANT CONDENSATION OF
LOWER LEVEL MOISTURE. FARTHER SOUTHEAST...THE HIGH CLOUDS ARE NOT
EXPECTED TO BECOME THICK ENOUGH TO PREVENT THE FORMATION OF SOME
LATE NIGHT LOW CLOUDS AND/OR FOG ALONG THE PECOS RIVER IN CHAVES
COUNTY AND EASTWARD ACROSS CENTRAL/SOUTHERN ROOSEVELT COUNTIES.
MODELS MAKE TUESDAY/WEDNESDAYS UPPER TROUGH OUT TO BE A BIT MORE
ORGANIZED IN THE LATEST RUNS WITH SOME AGREEMENT ON PRECIPITATION
MAINLY IN THE FORM OF RAIN SHOWERS ACROSS SOUTHERN AREAS. WITH 700
MB TEMPERATURES EXPECTED TO BE IN THE PLUS 2 TO 4 DEGREE
RANGE...THE SNOW LEVEL SHOULD BE QUITE HIGH. THE MAIN WAVE OF
PRECIPITATION LOOKS TO FAVOR LOCATIONS ALONG AND EAST OF THE
SOUTH CENTRAL MOUNTAINS TUESDAY AFTERNOON AND NIGHT. AT THIS TIME
MODELS SUGGEST WETTING PRECIP COULD BE SPOTTY. THE LAST COUPLE
SYSTEMS CAME IN A BIT WETTER THAN ORIGINALLY EXPECTED. THIS ONE
DIFFERS IN THAT ITS MOISTURE TAP IS MORE POULTRY AND OUT OF THE
SOUTH RATHER THAN OUT OF THE SW AND OFF THE BAJA COAST.
LOOKING AHEAD TO NEXT WEEKENDS STORM...GFS AND ECMWF ARE AGREEING
ON A DEEP UPPER TROUGH APPROACHING THE FOUR CORNERS AREA FROM THE
WEST NW...BUT THEY DISAGREE ON WHETHER WETTING PRECIP WILL SPREAD
INTO WESTERN NM FRIDAY NIGHT OR SATURDAY. THE STORM IS PROGGED
TO STRENGTHEN AS IT MOVES OVERHEAD LATER IN THE WEEKEND...AND IT
MAY DRAW A STRONG COLD FRONT THROUGH THE AREA.
44
&&
.FIRE WEATHER...
A SHORT-WAVE RIDGE CRESTING OVER THE REGION TODAY IS PROVIDING
SUNNY SKIES...LIGHT WINDS...AND LOWER SURFACE HUMIDITIES THAN ON
SATURDAY. WETTING RAINFALL THAT IMPACTED PORTIONS OF THE RIO
GRANDE VALLEY WILL RELEGATE VERY GOOD TO EXCELLENT RECOVERIES
TONIGHT. SOME PATCHY FOG MAY DEVELOP WITHIN CENTRAL AND WESTERN NM
HOWEVER CONFIDENCE IS NOT GOOD AS THICKER HIGH CLOUDS APPROACH
FROM THE WEST. DESPITE THICKER HIGH CLOUD COVER MONDAY HUMIDITY
VALUES WILL TREND LOWER AGAIN AND TEMPS WILL REMAIN ABOVE NORMAL.
WIDESPREAD POOR VENTILATION WILL BE PROBLEMATIC AGAIN.
THE RIDGE WILL BREAK DOWN THROUGH MONDAY NIGHT AS A WEAK UPPER WAVE
SLIDES VERY SLOWLY EAST ALONG THE AZ/MEXICO BORDER. LIGHT SOUTHERLY
FLOW ALOFT AHEAD OF THIS SYSTEM WILL ENHANCE MOIST RETURN FLOW OVER
PORTIONS OF EASTERN NEW MEXICO TUESDAY THROUGH THURSDAY. A FEW LIGHT
SHOWERS ARE POSSIBLE OVER THE SOUTHERN TIER...BUT MOST AREAS WILL
REMAIN DRY AND MILD FOR EARLY DECEMBER. WIDESPREAD POOR VENTILATION
WILL REMAIN AN ISSUE WITH THE GENERALLY LIGHT WINDS BENEATH THE SLOW
MOVING UPPER WAVE FOR CENTRAL/WESTERN NM. THE EAST WILL SEE A FEW
HOURS OF GOOD VENTILATION DURING THE AFTERNOON HOURS.
A WEAK TRANSIENT RIDGE WILL SLIDE EAST INTO THE REGION THURSDAY AND
HELP SCOUR ANY REMNANT MOISTURE OVER THE EAST. THIS RIDGE WILL BREAK
DOWN QUICKLY FRIDAY AHEAD OF A LARGE SCALE STORM SYSTEM CRASHING ONTO
THE WEST COAST. RIDGE TOP AND EAST SLOPE WINDS WILL BEGIN INCREASING
FRIDAY MORNING THEN SPREAD INTO THE PLAINS FRIDAY AND SATURDAY AS LEE
TROUGHING DEEPENS. VENTILATION WILL IMPROVE MOST AREAS AND TEMPS WILL
AVERAGE 5 TO 15F ABOVE NORMAL...ESPECIALLY AT NIGHT. MIN HUMIDITY
VALUES STILL REMAIN ELEVATED WITH MOST LOCALES ABOVE 25 TO 30 PCT.
EXTENDED GUIDANCE STILL ADVERTISES A MORE ACTIVE STORM TRACK WITH A
POSSIBLY SIGNIFICANT SLOW-MOVING STORM SYSTEM SUNDAY THROUGH EARLY
NEXT WEEK.
GUYER
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
1013 PM MST SUN DEC 7 2014
.UPDATE...
ADDED SOME PATCHY FOG TO NORTHWEST AND WEST CENTRAL NM FOR TONIGHT
ALTHOUGH CONFIDENCE NOT GREAT. LATEST RUC INDICATES DEWPOINTS TO
FALL SOMEWHAT AS TEMPERATURES CONTINUE TO COOL...AND A PERSISTENT
PATCH OF HIGH RH VALUES DEPICTED FROM THE FOUR CORNERS SOUTHEASTWARD
TOWARDS THE CUBA AREA. THERE IS ALSO A SLIVER OF MOISTURE SHOWN
WORKING UP THE PECOS VALLEY THROUGH KROW...SO INCREASED CLOUD
COVER THERE. TWEAKED A FEW OVERNIGHT LOW TEMPERATURES AS WELL.
UPDATED ZFP JUST TRANSMITTED.
&&
.PREV DISCUSSION...511 PM MST SUN DEC 7 2014...
.AVIATION...
00Z TAF CYCLE
LOW CLOUDS/FOG FINALLY DISSIPATED THIS AFTERNOON SOUTH OF
KFMN...HOWEVER THERE IS SOME CONCERN THAT IT WILL REDEVELOP
OVERNIGHT...AND MAY IMPACT KFMN. CONFIDENCE IS NOT HIGH ENOUGH TO
INSERT INTO THE TAF ATTM...BUT WILL NEED TO BE MONITORRED. THE
REASON FOR THE LOW CONFIDENCE IS A SCT-BKN CIRRUS LAYER MOVING
EAST TO WEST OVER THE AREA. HI-RES MODELS ALSO SHOWING SOME LOW
CLOUD DEVELOPMENT ALONG THE PECOS RIVER VALLEY NEAR KROW. HAVE
SLIGHTLY HIGHER CONFIDENCE IN THIS SCENARIO AS IT WILL TAKE LONGER
FOR THE HIGH CLOUDS TO MOVE OVERHEAD.
34
&&
.PREV DISCUSSION...328 PM MST SUN DEC 7 2014...
.SYNOPSIS...
THE RECENT WARMING AND DRYING TREND WILL CONTINUE THROUGH MONDAY.
THEN...A WEAK UPPER LEVEL TROUGH CROSSING FROM THE UPPER BAJA
PENINSULA WILL BRING A CHANCE FOR SHOWERS MAINLY TO LOCATIONS
SOUTH OF INTERSTATE 40 TUESDAY THROUGH WEDNESDAY. AFTER ANOTHER
WARMER AND DRIER PERIOD DURING THE LATTER HALF OF THE WORK
WEEK...A STRONGER AND COLDER SYSTEM IS FORECAST TO CROSS SLOWLY
FROM THE WEST NORTHWEST WITH WIDESPREAD PRECIPITATION THIS WEEKEND.
&&
.DISCUSSION...
DESPITE A RIDGE OF HIGH PRESSURE THAT WILL ARRIVE OVERHEAD FROM
THE WEST...ABUNDANT HIGH CLOUDS WILL MOVE OVER CENTRAL AND
ESPECIALLY WESTERN AREAS FROM THE WEST TONIGHT. MODEL SURFACE RH
PROGS SUGGEST THERE IS ENOUGH MOISTURE FOR A RETURN OF LOW CLOUDS
AND POSSIBLY PATCHY FOG TO PARTS OF THE NORTHWEST AND WEST CENTRAL
PLATEAU...BUT THE HIGH CLOUDS ARE CURRENTLY EXPECTED TO INHIBIT
RADIATIONAL COOLING ENOUGH TO PREVENT SIGNIFICANT CONDENSATION OF
LOWER LEVEL MOISTURE. FARTHER SOUTHEAST...THE HIGH CLOUDS ARE NOT
EXPECTED TO BECOME THICK ENOUGH TO PREVENT THE FORMATION OF SOME
LATE NIGHT LOW CLOUDS AND/OR FOG ALONG THE PECOS RIVER IN CHAVES
COUNTY AND EASTWARD ACROSS CENTRAL/SOUTHERN ROOSEVELT COUNTIES.
MODELS MAKE TUESDAY/WEDNESDAYS UPPER TROUGH OUT TO BE A BIT MORE
ORGANIZED IN THE LATEST RUNS WITH SOME AGREEMENT ON PRECIPITATION
MAINLY IN THE FORM OF RAIN SHOWERS ACROSS SOUTHERN AREAS. WITH 700
MB TEMPERATURES EXPECTED TO BE IN THE PLUS 2 TO 4 DEGREE
RANGE...THE SNOW LEVEL SHOULD BE QUITE HIGH. THE MAIN WAVE OF
PRECIPITATION LOOKS TO FAVOR LOCATIONS ALONG AND EAST OF THE
SOUTH CENTRAL MOUNTAINS TUESDAY AFTERNOON AND NIGHT. AT THIS TIME
MODELS SUGGEST WETTING PRECIP COULD BE SPOTTY. THE LAST COUPLE
SYSTEMS CAME IN A BIT WETTER THAN ORIGINALLY EXPECTED. THIS ONE
DIFFERS IN THAT ITS MOISTURE TAP IS MORE POULTRY AND OUT OF THE
SOUTH RATHER THAN OUT OF THE SW AND OFF THE BAJA COAST.
LOOKING AHEAD TO NEXT WEEKENDS STORM...GFS AND ECMWF ARE AGREEING
ON A DEEP UPPER TROUGH APPROACHING THE FOUR CORNERS AREA FROM THE
WEST NW...BUT THEY DISAGREE ON WHETHER WETTING PRECIP WILL SPREAD
INTO WESTERN NM FRIDAY NIGHT OR SATURDAY. THE STORM IS PROGGED
TO STRENGTHEN AS IT MOVES OVERHEAD LATER IN THE WEEKEND...AND IT
MAY DRAW A STRONG COLD FRONT THROUGH THE AREA.
44
&&
.FIRE WEATHER...
A SHORT-WAVE RIDGE CRESTING OVER THE REGION TODAY IS PROVIDING
SUNNY SKIES...LIGHT WINDS...AND LOWER SURFACE HUMIDITIES THAN ON
SATURDAY. WETTING RAINFALL THAT IMPACTED PORTIONS OF THE RIO
GRANDE VALLEY WILL RELEGATE VERY GOOD TO EXCELLENT RECOVERIES
TONIGHT. SOME PATCHY FOG MAY DEVELOP WITHIN CENTRAL AND WESTERN NM
HOWEVER CONFIDENCE IS NOT GOOD AS THICKER HIGH CLOUDS APPROACH
FROM THE WEST. DESPITE THICKER HIGH CLOUD COVER MONDAY HUMIDITY
VALUES WILL TREND LOWER AGAIN AND TEMPS WILL REMAIN ABOVE NORMAL.
WIDESPREAD POOR VENTILATION WILL BE PROBLEMATIC AGAIN.
THE RIDGE WILL BREAK DOWN THROUGH MONDAY NIGHT AS A WEAK UPPER WAVE
SLIDES VERY SLOWLY EAST ALONG THE AZ/MEXICO BORDER. LIGHT SOUTHERLY
FLOW ALOFT AHEAD OF THIS SYSTEM WILL ENHANCE MOIST RETURN FLOW OVER
PORTIONS OF EASTERN NEW MEXICO TUESDAY THROUGH THURSDAY. A FEW LIGHT
SHOWERS ARE POSSIBLE OVER THE SOUTHERN TIER...BUT MOST AREAS WILL
REMAIN DRY AND MILD FOR EARLY DECEMBER. WIDESPREAD POOR VENTILATION
WILL REMAIN AN ISSUE WITH THE GENERALLY LIGHT WINDS BENEATH THE SLOW
MOVING UPPER WAVE FOR CENTRAL/WESTERN NM. THE EAST WILL SEE A FEW
HOURS OF GOOD VENTILATION DURING THE AFTERNOON HOURS.
A WEAK TRANSIENT RIDGE WILL SLIDE EAST INTO THE REGION THURSDAY AND
HELP SCOUR ANY REMNANT MOISTURE OVER THE EAST. THIS RIDGE WILL BREAK
DOWN QUICKLY FRIDAY AHEAD OF A LARGE SCALE STORM SYSTEM CRASHING ONTO
THE WEST COAST. RIDGE TOP AND EAST SLOPE WINDS WILL BEGIN INCREASING
FRIDAY MORNING THEN SPREAD INTO THE PLAINS FRIDAY AND SATURDAY AS LEE
TROUGHING DEEPENS. VENTILATION WILL IMPROVE MOST AREAS AND TEMPS WILL
AVERAGE 5 TO 15F ABOVE NORMAL...ESPECIALLY AT NIGHT. MIN HUMIDITY
VALUES STILL REMAIN ELEVATED WITH MOST LOCALES ABOVE 25 TO 30 PCT.
EXTENDED GUIDANCE STILL ADVERTISES A MORE ACTIVE STORM TRACK WITH A
POSSIBLY SIGNIFICANT SLOW-MOVING STORM SYSTEM SUNDAY THROUGH EARLY
NEXT WEEK.
GUYER
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1241 AM EST MON DEC 8 2014
.SYNOPSIS...
LOW PRESSURE WILL DEVELOP EARLY MONDAY ALONG A STALLED FRONT
OFFSHORE. THIS WILL BRING COOL WEATHER MONDAY ALONG WITH A CHANCE
OF LIGHT RAIN. THE LOW WILL PULL AWAY FROM THE AREA TUESDAY WITH
DRIER AIR OVERSPREADING THE AREA. BELOW NORMAL TEMPERATURES AND DRY
WEATHER IS EXPECTED FOR MUCH OF THE WEEK AS CANADIAN HIGH PRESSURE
SLOWLY APPROACHES FROM THE NORTHWEST.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 930 PM SUNDAY...NO PRECIPITATION IS ANTICIPATED OVERNIGHT
AND CLOUDS ARE EXPECTED TO INCREASE OVERNIGHT. THE 18 UTC NAM IS
SHOWING THIS IN INCREASE IN CLOUDS BEING SUPPORTED BY A 90% RH
LAYER OF MOISTURE MOVING INLAND IN RESPONSE TO THE WINDS AT 850 MB
VEERING TO THE EAST OVERNIGHT. MINIMUM TEMPERATURES ARE EXPECTED
TO FALL INTO THE LOW TO MIDDLE 30S BUT INCREASING CLOUDS OVERNIGHT
WILL TEMPER THE TEMPERATURES DECREASE.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 300 PM SUNDAY...AN UPPER LEVEL TROUGH WILL APPROACH FROM THE
WEST TUESDAY...TURNING NEGATIVELY TILTED AT 500 MB AS MOVES ACROSS
THE AREA DURING THE EVENING HOURS. THE APPROACH OF THIS TROUGH
SHOULD INDUCE LOW PRESSURE TO DEVELOP ALONG THE STALLED FRONT ABOUT
400 MILES EAST OF CAPE FEAR MONDAY. THE SURFACE LOW WILL BE PULLED
NORTHWESTWARD BY THE APPROACHING UPPER TROUGH TOWARD THE NC OUTER
BANKS. INCREASING EASTERLY WINDS BETWEEN 3000-6000 FEET WILL BE
FORCED TO ASCEND AS THEY RIDE UP OVER A COOL WEDGE AIR MASS INLAND
AND THIS SHOULD DEVELOP PATCHES OF MAINLY LIGHT RAIN DURING THE
AFTERNOON AND EVENING HOURS...ESPECIALLY ACROSS THE PEE DEE REGION
AND SAND HILLS WHERE THE 285K ISENTROPIC SURFACE HAS THE MOST
RELATIVE TILT. THE MAGNITUDE OF 285K ISENTROPIC LIFT MATCHES
EXPECTED COVERAGE AND INTENSITY OF RAIN. THIS SHOULD NOT BE A MAJOR
RAINFALL EVENT WITH ONLY A FEW HUNDREDTHS OF AN INCH EXPECTED.
THE ECMWF CONTINUES TO BE OUR PREFERRED MODEL ALTHOUGH THE 12Z GFS
WASN`T TOO BAD. THE 12Z NAM WAS NOT USED. GIVEN DENSE CLOUD COVER
AND THE WEDGE PATTERN MY FORECAST HIGHS ARE BELOW GUIDANCE ACROSS
NE SOUTH CAROLINA AND THE LUMBERTON AREA MONDAY: MID 40S INLAND
TO 50-51 AT THE COAST. LOWS MONDAY NIGHT MID-UPPER 30S.
TUESDAY...DEEP WEST AND NW WINDS SHOULD DRY THE COLUMN OUT WITH
PLENTY OF SUNSHINE DEVELOPING DURING THE DAY. HIGHS SHOULD REACH
THE LOWER-MID 50S AND LOWS MID-UPPER 30S.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 300 PM SUNDAY...A STRONG OMEGA BLOCK WILL DEVELOP AT THE MID
LEVELS WITH THE FIRST VESTIGES SEEN THURSDAY. A POTENT MID LEVEL LOW
WILL BE MEANDERING ACROSS THE NORTHEAST STATES WITH A DEEP LONG WAVE
TROUGH CRASHING ASHORE ALONG THE WEST. RIDGING WILL BE TAKING PLACE
ACROSS THE CENTRAL U.S. THIS PATTERN WILL BECOME MORE AMPLIFIED IN
TIME. BY THE END OF THE PERIOD...THE FLOW/PATTERN IS STILL INTACT
BUT DOES SHOW SIGNS OF BREAKING DOWN AND MOVING EAST.
THE SURFACE FEATURES OF NOTE INCLUDE LOW PRESSURE ACROSS THE
NORTHEAST AND HIGH PRESSURE ACROSS THE MISSISSIPPI VALLEY. A
CYCLONIC/COLD AND DRY FLOW WILL BE IN PLACE WEDNESDAY THROUGH
SATURDAY WITH A COUPLE OF SURFACE TROUGHS MOVING ACROSS...THESE
ASSOCIATED WITH WEAKER MID LEVEL FEATURES. BY LATER SATURDAY AND
SUNDAY...HIGH PRESSURE WILL SLOWLY BEGIN TO MOVE EAST. NO POPS
THROUGH THE PERIOD.
TEMPERATURE GUIDANCE SHOWS A REASONABLE TREND WITH COLD READINGS
WEDNESDAY THROUGH FRIDAY...LOW TO MIDDLE 50S FOR HIGHS WITH LOWS AT
OR JUST BELOW FREEZING. THE COLDEST MORNING APPEARS TO BE FRIDAY
WITH LINGERING COLD AIR UPSTAIRS AND DECENT RADIATIONAL CONDITIONS.
AIR MASS MODIFICATION WILL BEGIN TO SLOWLY WARM THINGS UP FOR THE
WEEKEND.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 06Z...TEMPO MVFR CIGS BECOMING WIDESPREAD LATER THIS MORNING
AND CONTINUING THROUGH THE VALID TAF PERIOD WITH INCREASING RAIN
CHANCES.
EXPECT MVFR CIGS TO GRADUALLY OVERSPREAD THE TAF SITES THIS MORNING
AND THEN TO PERSIST THROUGH THE REMAINDER OF THE TAF PERIOD. THE
RISK FOR LIGHT RAIN WILL BE ON THE INCREASE THIS AFTERNOON AND EVE
AND THEN ENDINIG FROM W TO E LATE TONIGHT. GUSTY NORTH WINDS FOR
MUCH OF THE PERIOD WILL SLOWLY DECREASE TONIGHT.
EXTENDED OUTLOOK...MVFR CIGS/LIGHT RAIN LATE TONIGHT. OTHERWISE
EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 930 PM SUNDAY...A MARGINAL GALE WARNING CONTINUES FOR N
WINDS OF 25 TO 30 KT INTO TONIGHT AS GUSTS ARE STILL AROUND THE 35
KT LEVEL AT 41013. THE 00 UTC RUN OF THE HRRR CONTINUES TO SHOW THE
PRESSURE GRADIENT TIGHT OVERNIGHT AND IS MAINTAINING THE 25 TO 30
KT WINDS WITH HIGHER GUST OVERNIGHT. SEAS WILL CONTINUE AT 5 TO 7
FT...WITH HIGHER SEAS AT 20 MILES OFF THE COAST AND IN SOUTH
CAROLINA WATERS SOUTH OF MYRTLE BEACH. LOWER WAVE HEIGHTS ARE
EXPECTED NEARER THE COAST WHERE WIND DIRECTION WILL BE
OFFSHORE...MAINLY BETWEEN BALD HEAD AND NORTH MYRTLE BEACH.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 300 PM SUNDAY...1045 MB ARCTIC HIGH PRESSURE WILL BE MOVING
INTO THE CANADIAN MARITIME PROVINCES MONDAY MORNING WHILE LOW
PRESSURE DEVELOPS ABOUT 400 MILES EAST OF CAPE FEAR ALONG THE
STALLED FRONT. ALTHOUGH THE MODELS DIFFER IN DETAILS ALL GUIDANCE
SHOWS THE LOW MOVING NORTHWESTWARD TOWARD THE OUTER BANKS MONDAY
AFTERNOON AND EVENING...TURNING NORTHWARD BEFORE REACHING LAND
OVERNIGHT. FOR OUR PORTION OF THE CAROLINAS THIS MEANS A
CONTINUATION OF BRISK NORTHERLY WINDS THROUGH MONDAY NIGHT...
ALBEIT WITH GRADUALLY DIMINISHING WIND SPEEDS DUE TO LESSENING
INFLUENCE FROM THE CANADIAN HIGH.
AS THE LOW MOVES ALONG THE MID-ATLANTIC COAST TUESDAY...OUR WINDS
SHOULD BACK TO THE NORTHWEST ALLOWING DRIER AIR TO BUILD OFFSHORE.
LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 300 PM SUNDAY...EXPECT STEADY STATE CONDITIONS WEDNESDAY AND
EARLY THURSDAY WITH NORTHWEST WINDS OF 10-15 KNOTS AND SEAS OF 2-5
FEET WITH THE FIVE FOOTERS RELEGATED TO THE OUTERMOST WATERS. A
SURFACE TROUGH WILL MOVE ACROSS EARLY THURSDAY TO KICK UP WINDS A
COUPLE OF KNOTS BRIEFLY. LATER THURSDAY...WINDS DIMINISH TO AROUND
TEN KNOTS WHICH WILL CONTINUE THROUGH FRIDAY. SEAS DROP TO 1-3
FEET.
&&
.TIDES/COASTAL FLOODING...
AS OF 300 PM SUNDAY...STORM SURGE AT MYRTLE BEACH IS APPROACHING
1.0 FEET THIS AFTERNOON. ASTRONOMICAL TIDE PREDICTIONS SHOW WE
WILL NEED 1.6 FEET OF SURGE TO PRODUCE MINOR COASTAL FLOODING AT
MYRTLE BEACH WITH THE MONDAY MORNING (820 AM) HIGH TIDE. NO
COASTAL FLOODING ADVISORIES ARE PLANNED AT THIS TIME.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...GALE WARNING UNTIL 6 AM EST MONDAY FOR AMZ250-252-254-256.
&&
$$
NEAR TERM...DRH
SHORT TERM...TRA
LONG TERM...SHK
AVIATION...SGL/RJD
TIDES/COASTAL FLOODING...TRA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
235 AM CST MON DEC 8 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 234 AM CST MON DEC 8 2014
THE MAIN FOCUS FOR THE SHORT TERM IS CLOUD COVER AND TEMPERATURES.
THE LOW PRESSURE RESPONSIBLE FOR THE LIGHT SNOW LAST NIGHT
CONTINUES TO PUSH OUT OF NORTH DAKOTA THIS MORNING. THE LOW IS
DRAGGING AN AREA OF LOW STRATUS IN ITS WAKE. THE STRATUS HAS BEEN
CONFINED TO ALONG AND EAST OF THE MISSOURI RIVER SO FAR. THERE IS
A POSSIBILITY THAT THE STRATUS WILL EXTEND A LITTLE FURTHER WEST
THIS MORNING BEFORE IT BEGINS CLEARING FROM WEST TO EAST BY THIS
AFTERNOON. THE LATEST HRRR RUN INDICATES CLOUD COVER COULD ENTER
WILLISTON WITHIN THE NEXT COUPLE OF HOURS.
THE STRATUS WILL WREAK HAVOC ON TEMPERATURES EARLY THIS
MORNING...INTO THE AFTERNOON HOURS. AREAS UNDER THE STRATUS WILL
SEE LITTLE CHANGE IN TEMPERATURES WITH SLIGHTLY WARMER READINGS
EARLY THIS MORNING AND SLIGHTLY COOLER READINGS FOR DAYTIME HIGHS.
WHILE AREAS UNDER CLEAR SKIES WILL HAVE AN EASIER TIME REBOUNDING
FROM OVERNIGHT LOWS. THIS IS REFLECTED IN THE HIGH TEMPERATURE
FORECAST FOR TODAY WITH 30S EXPECTED ACROSS THE CLEAR SOUTHWEST
AND TEENS/20S EXPECTED ACROSS THE NORTHERN JAMES VALLEY.
OVERALL A RATHER PLEASANT DAY IS EXPECTED AS WINDS WILL CONTINUE
TO DIMINISH AND SKIES SLOWLY CLEAR THROUGH THE DAY.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 234 AM CST MON DEC 8 2014
BROAD UPPER LEVEL RIDGING IS FORECAST BUILD INTO THE REGION
THROUGH THE END OF THE WEEK...THEN BEGIN TO BREAK DOWN OVER THE
WEEKEND.
FOR TUESDAY...A RIDGE-RUNNER SHORTWAVE IS FORECAST TO TRAVERSE
NORTH DAKOTA. EVEN THOUGH UPPER LEVEL SUPPORT SHOULD BE STRONG
ENOUGH TO GENERATE ELEVATED SNOW SHOWERS...THE MODEL SOUNDINGS
INDICATE THAT A DRY THERMODYNAMIC PROFILE UP TO 600MB WILL BE IN
PLACE. THEREFORE...VIRGA WILL LIKELY BE OBSERVED TUESDAY.
HOWEVER...WOULD NOT BE SURPRISED IF A FEW FLAKES REACHED THE
SURFACE SOUTHWEST OF THE MISSOURI RIVER TUESDAY. DUE TO THE STRONG
UPPER FORCING BUT DRY BOUNDARY LAYER CONDITIONS...HANDLED THIS
SCENARIO WITH SILENT POPS IN THE GRIDS FOR NOW.
THE UPPER RIDGE IS FORECAST TO SHARPEN OVER THE NORTHERN PLAINS
WEDNESDAY THROUGH FRIDAY...WITH FRIDAY FORECAST TO BE THE WARMEST
DAY OF THE EXTENDED. FRIDAY FORECAST HIGH TEMPERATURES RANGE FROM
THE UPPER 30S TO UPPER 40S.
THE UPPER RIDGE IS PROGGED TO BEGIN TO BREAK DOWN SATURDAY AS A
LONG WAVE TROUGH ENTERS THE ROCKIES. THE MAIN ENERGY FROM THE
TROUGH IS GENERALLY FORECAST TO MOVE EAST INTO NORTH DAKOTA
SATURDAY NIGHT INTO SUNDAY. WILL CONTINUE TO BROAD BRUSH A SLIGHT
CHANCE OF SNOW SATURDAY NIGHT/SUNDAY GIVEN THE MODEL TO MODEL AND
RUN TO RUN INCONSISTENCIES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1240 AM CST MON DEC 8 2014
WIDESPREAD MVFR WITH OCCASIONAL IFR CIGS WILL CONTINUE THROUGH
TONIGHT AT KMOT/KJMS/KBIS. KISN COULD MOVE IN AND OUT OF CLOUD
COVER TONIGHT AS A STRATUS DECK HOVERS NEARBY. KDIK SHOULD REMAIN
CLEAR THROUGH THE TAF PERIOD. OVER FAR WESTERN NORTH DAKOTA...LCL
FG MAY DEVELOP LATE TONIGHT AS SKIES CLEAR AND WIND DIMINISHES.
WITH THE LOW COVERAGE AND STILL SOME QUESTION ON WHETHER IT WILL
DEVELOP HAVE WITHHELD FROM MENTIONING IN INDIVIDUAL TERMINAL
FORECASTS. CONDITIONS WILL IMPROVE TO VFR BY MID-MORNING SUNDAY
OVER MOST LOCATIONS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...TM
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1143 PM CST SUN DEC 7 2014
.UPDATE...
ISSUED AT 1134 PM CST SUN DEC 7 2014
BACK EDGE OF LAST SNOW BAND MOVING THROUGH THE WESTERN FA AND WILL
CONTINUE TO PUSH EAST OVERNIGHT. FEEL FREEZING RAIN THREAT HAS
ENDED WITH COOLING COLUMN HOWEVER MAY STILL BE SOME POTENTIAL FOR
SOME FZDZ AS MID LEVELS DRY OVERNIGHT AND STRATUS HOLDS. MAIN PUSH
OF LOW LEVEL COLD ADVECTION WORKING THROUGH THE WESTERN FA WHICH
WILL START COOLING TEMPERATURES ACROSS THE SOUTH WHICH REMAIN
MILD.
UPDATE ISSUED AT 956 PM CST SUN DEC 7 2014
WILL CONTINUE TO MONITOR AVAILABLE GUIDANCE FOR PCPN PHASE
POTENTIAL REMAINDER OF THE OVERNIGHT. LATEST RUC SOUNDINGS
BECOMING MORE FAVORABLE FOR SNOW VS ZR AND METARS ACROSS THE NORTH
HAVE TRANSITIONED OVER TO -SN. SECONDARY NARROW DEF ZONE BAND
MOVING INTO THE WESTERN FA PRIMARILY SNOW ALTHOUGH COULD SEE A
BRIEF MIX. THIS FEATURE MOVING PRETTY QUICK SO NOT EVEN SURE AT
THIS POINT IF WE WILL SEE MEASURABLE PCPN WITH THIS UNLESS IT
EXPANDS.
UPDATE ISSUED AT 639 PM CST SUN DEC 7 2014
MAIN CONCERN WILL BE WHETHER ADDITIONAL HEADLINES WILL BE NEEDED
UNTIL COLUMN COOLS SUFFICIENTLY FOR ONLY SNOW. CURRENTLY A SMALL
AREA OF ENHANCED REFLECTIVITIES ALONG INTERNATIONAL BORDER AREA
FROM THE NORTHERN VALLEY INTO FAR NORTHERN MN. TEMPERATURES
CURRENTLY A FEW DEGREES ABOVE FREEZING HOWEVER AS TEMPERATURES
COOL WITH COLD ADVECTION NOSING IN ROADS COULD BECOME GLAZED. WILL
MONITOR PHASE AND TEMPERATURES AND IF NEEDED WILL ISSUE PROPER
HEADLINES. DID INCREASE POPS THIS AREA OTHERWISE NO REAL BIG
CHANGES AT THIS POINT.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 301 PM CST SUN DEC 7 2014
MIXED PRECIP WILL CONTINUE TO BE THE MAIN ISSUE THROUGH TONIGHT.
THE MAIN SHORTWAVE TROUGH CONTINUES TO MOVE THROUGH WESTERN ND SO
THE CWA WILL CONTINUE TO SEE SOME BROAD LIFT OVER THE REGION
THROUGH TONIGHT. THE WARM AIR ADVECTION FREEZING RAIN OVER OUR
EASTERN COUNTIES EARLIER TODAY HAS FINALLY MOVED OFF TO THE EAST
AND WILL LET THE ADVISORY GO BEFORE IT EXPIRES THIS AFTERNOON.
THERE HAS BEEN SOME WEAK PRECIP DEVELOPMENT OVER THE NORTHWESTERN
CWA AS THE CENTER OF THE SFC LOW BEGINS TO MOVE INTO THE AREA.
MODELS ALL BREAK OUT PERIODIC PRECIP OVER THE CWA AS THE LOW MOVES
ACROSS THE REGION THIS EVENING. THERE ARE SOME DIFFERENCES IN
EXACTLY WHERE THE PRECIP BREAKS OUT AND TIMING...SO WILL KEEP
MAINLY CHANCE POPS WITH SOME HIGHER LATER TONIGHT OVER
NORTHEASTERN COUNTIES AS THERE SEEMS TO BE SOME CONSOLIDATION OF
WRAP AROUND.
AS FAR AS TYPE...TEMPS IN THE NORTHWEST ARE JUST BELOW OR ABOVE
THE FREEZING MARK. SOME MIXED PRECIP WAS REPORTED IN LANGDON BUT
OTHER AREAS HAVE SEEN ONLY RAIN. THE POWT TOOL GIVES RAIN OVER
MUCH OF THE LOWER DEVILS LAKE BASIN WITH SOME IP AND FZRA MIXING
IN CLOSER TO THE CANADIAN BORDER. THIS SEEMS REASONABLE AT THIS
POINT. THE MIXED BAG OF PRECIP WILL SPREAD SOUTH AND EAST
THROUGHOUT THE EVENING...BUT WITH ONLY SOME CHANCE OF SCATTERED
ACTIVITY AND WHAT DOES OCCUR VERY LIGHT...WILL KEEP ANY HEADLINES
OUT FOR NOW. THE WARM LAYER ALOFT BEGINS TO BE ERODED AFTER
MIDNIGHT...AND PRECIP SHOULD SWITCH OVER TO ALL SNOW BY MORNING.
SOME LIGHT SNOW SHOWERS WILL LINGER OVER THE NORTHEASTERN CWA
THROUGHOUT THE DAY ON MONDAY...BUT ANY ACCUMULATIONS WILL BE AROUND
AN INCH OR LESS.
AS FOR TEMPERATURES...WITH A WARM START THIS EVENING AND THE TRUE
COLD AIR SURGE NOT REALLY COMING DOWN UNTIL WELL AFTER
MIDNIGHT...LOWS WILL REMAIN IN THE TEENS TO 20S. COLD AIR
ADVECTION WILL CONTINUE INTO MONDAY AS THE SFC HIGH SETTLES OVER
THE NORTHERN PLAINS. AFTERNOON TEMPS WILL ONLY TOP OUT IN THE 20S.
LOWS MONDAY NIGHT WILL DROP INTO THE SINGLE DIGITS AS WE BEGIN TO
SEE SOME CLEARING ON THE BACK SIDE OF THE SFC HIGH.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 301 PM CST SUN DEC 7 2014
TUESDAY AND WEDNESDAY...THE 500MB HEIGHTS RISE AND CONDITIONS WILL
BE FAIRLY QUIET ALTHOUGH THERE WILL BE A WEAK SHORTWAVE EMBEDDED
UNDER THE UPPER RIDGE OVER THE CENTRAL CONUS. THE NAM TRIES TO
BRING IN SOME LOW LEVEL MOISTURE AND LIGHT PRECIP INTO THE CWA ON
WEDNESDAY AS WINDS SHIFT TO THE SOUTH...BUT IT SEEMS TO BE AN
OUTLIER SO WILL JUST KEEP AN EYE ON IT FOR NOW. TEMPS ON TUESDAY
WILL REMAIN IN THE 20S BUT THERE SHOULD BE SOME GOOD WARMING ON
WEDNESDAY AS 850MB TEMPS NEARING 5 TO 8 C ARRIVE. HIGHS SHOULD BE
BACK UP INTO THE 30S IN MANY AREAS.
WEDNESDAY NIGHT-SUNDAY...MUCH OF THIS TIME PERIOD WILL BE MILD AND
DRY AS UPPER LEVEL RIDGING BUILDS ACROSS THE PLAINS. HIGH TEMPS
THROUGH SATURDAY SHOULD AT LEAST REACH THE 30S...AND POSSIBLY
WARMER. GLOBAL MODELS DEPICT THE RIDGE AXIS TO SHIFT EAST BY LATE
NEXT WEEKEND AS UPSTREAM ENERGY APPROACHES. HOWEVER...FORECAST
DETAILS LACK CLARITY BY THIS TIME...WITH MODELS DIFFERING ON THE
MOVEMENT OF THE CLOSED EASTERN CONUS UPPER LOW AND THE EVOLUTION OF
THE VARIOUS SHORTWAVES APPROACHING FROM THE WEST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1134 PM CST SUN DEC 7 2014
CIGS CONTINUE TO VARY SOME UNDER UPPER LOW NOW MOVING THROUGH
WESTERN MN. IN ITS WAKE MVFR CIGS FAIRLY WIDESPREAD. CONVECTIVE
TEMPERATURES TOMORROW LOW SO FEEL CLOUDS MVFR CIGS WILL HOLD MOST
OF THE DAY. SOME BREAKS SHOULD OCCUR TOMORROW AFTERNOON FROM WEST
TO EAST. WINDS WILL REMAIN BLUSTERY THROUGH MUCH OF THE DAY WITH
20 TO 30KTS THROUGH SHALLOW MIXED LAYER.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...VOELKER
SHORT TERM...JR
LONG TERM...JR/MAKOWSKI
AVIATION...VOELKER
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1155 PM CST SUN DEC 7 2014
.AVIATION...
/06Z TAFS/
Challenging flight weather continues tonight. Patchy fog and
stratus is producing areas of MVFR to IFR conditions. Satellite
imagery animation indicates the stratus and fog are moving,
developing, or dissipating randomly. Thus, confidence for dominate
VFR tonight isn`t high. Tomorrow, expect VFR conditions.
&&
.PREV DISCUSSION... /ISSUED 630 PM CST SUN DEC 7 2014/
AVIATION...
/00Z TAFS/
Look for challenging flight weather conditions tonight. A line of
showers will continue to slowly drift south tonight. Also, patchy
fog will likely drop the visibility to near the MVFR range at some
terminals. In addition, satellite imagery shows some patchy stratus
still lingering. Thus, watch for MVFR ceilings tonight.
PREV DISCUSSION... /ISSUED 336 PM CST SUN DEC 7 2014/
SHORT TERM...
(Tonight and Monday)
The primary focus in the short term will be ongoing rain chances
and the return of fog and low visibilities to the forecast area.
Light rain showers will migrate east across the forecast area this
afternoon. Rainfall totals will remain low, though any precip will
assist in keeping the area moist. Inherited PoP grids are adequate
for expected weather this afternoon though new model data is
pessimistic about tonight and early tomorrow morning. Thus, removed
mention of PoPs for that time period.
NAM, GFS, and RAP model soundings are optimistic about bringing fog
back into West Central Texas tonight. At this time, fog is
expected to form sometime after midnight and lift shortly after 9
AM tomorrow. Areas of fog will likely be more widespread tonight
than they were early this morning, extending from south of
Interstate 10 to north of Throckmorton. Light winds tonight and
added moisture from today`s rain showers promote this solution.
Cloud cover kept temperatures from climbing too quickly this
morning resulting in afternoon highs near normal. Tonight, however,
added moisture and low cloud ceilings will insulate the forecast
area and keep temperatures 5-7 degrees above normal. Clearing
skies tomorrow afternoon will allow for unseasonably warm
temperatures with highs mainly in the mid 60s.
18
LONG TERM...
(Monday night through Sunday)
Shortwave ridging aloft Monday night will shift east as we head
into Tuesday as a weak shortwave trough moves across the
Rockies. This feature will move southeast into Plains by Wednesday
morning, slowing as it absorbs southern stream wave over the
southern Plains. Moisture will be slow to increase ahead of this
system, with dewpoints likely remaining in the lower 40s
throughout the day Tuesday. We should see ample high clouds,
keeping temperatures in the mid 60s Tuesday afternoon, but low
clouds are not expected until Tuesday night. This increasing
moisture and cloud cover will limit diurnal ranges and keep min
temps generally in the mid/upper 40s for Wednesday morning.
There are considerable differences in the midweek 500 mb pattern
between the GFS, ECMWF, and GEM, yielding low confidence in any
particular solution at this time. The GFS is the fastest of the
12z runs with the onset of isentropic ascent across West Central
TX with the ECMWF following suit 6-12 hours later. Given what has
been as progressive flow as of late, siding with a bit faster
solution seems reasonable. This broad, isentropic ascent will
result in an abundance of cloud cover Wednesday and Thursday with
a persistent southerly fetch at low-levels, maintaining modest
moisture advection. Rainfall is expected to be rather light,
similar to what we`re seeing today across the area, with amounts
typically under 1/10". The cloud cover and light precipitation
will also keep temps around 60 degrees, with the potential to be a
few degrees cooler if light rain showers are a bit more widespread
than anticipated. Low rain chances will hang around through
Thursday night as weak perturbations move through the flow aloft.
By Friday, we should see improving conditions as the shortwave
trough moves east and shortwave ridging returns. This should allow
a modest warm-up with dry weather anticipated heading into the
weekend. We are watching a rather strong trough setting course for
the west coast late in the week. The medium range models are
moving this trough across the Rockies over the weekend, backing
winds aloft to the southwest. The associated lee cyclogenesis will
enhance low-level winds and should promote increasing surface
moisture. The timing of this feature`s effects for West Central TX
is certainly up in the air at this time, but there is pretty
decent model consensus that a closed mid-level cyclone develops
and moves east-southeast into West TX around Sunday. This pattern
bears watching as it could provide the area with a good
opportunity for measurable rainfall. As usual, there is plenty of
time for things to change, but we`ll be watching!
Johnson
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 40 66 43 66 45 / 5 0 0 0 10
San Angelo 40 66 43 66 45 / 5 0 0 5 20
Junction 41 68 41 66 45 / 10 5 0 0 10
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
Aviation: Huber
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1135 PM CST SUN DEC 7 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 221 PM CST SUN DEC 7 2014
WATER VAPOR SATELLITE IMAGERY SHOWING THE LEAD SHORT WAVE TROUGH
WAS WORKING ACROSS WESTERN MINNESOTA AND IOWA EARLY THIS
AFTERNOON. THE 07.12Z NAM AND GFS ALONG WITH THE 07.15Z RAP IN
PRETTY GOOD AGREEMENT IN SHOWING THIS WAVE BREAKING INTO TWO PARTS
AS THE AFTERNOON CONTINUES. THE NORTHERN PART OF THE WAVE EITHER
DISSIPATES AHEAD OF THE UPPER LEVEL LOW OVER NORTH DAKOTA OR MOVES
NORTHEAST TOWARD LAKE SUPERIOR. THE SOUTHERN PART OF THE WAVE IS
EXPECTED TO CONTINUE MOVING EAST/SOUTHEAST BUT GOING SOUTH OF THE
AREA ACROSS IOWA AND MISSOURI. AS THIS OCCURS...THE LINE OF RADAR
RETURNS TO THE WEST OF THE AREA IS EXPECTED TO GRADUALLY WEAKEN
AND IS NOT EXPECTED TO PRODUCE MUCH IF ANY PRECIPITATION...BUT
SHOULD HELP TO MOISTEN THE COLUMN. IT NOW APPEARS AS IF THE MAIN
PRECIPITATION BAND WILL OCCUR AHEAD OF THE SECOND AND STRONGER
SHORT WAVE TROUGH ROTATING AROUND THE UPPER LEVEL LOW. THE WAVE
WILL COME ACROSS CENTRAL AND NORTHERN MINNESOTA THIS EVENING AND
NORTHERN MINNESOTA OVERNIGHT. THIS WAVE SHOULD PRODUCE MODERATE
PV ADVECTION IN THE 500-300 MB LAYER AS IT COMES ACROSS THE REGION
WITH WEAK QG CONVERGENCE IN THE 1000-300 MB LAYER.
ISENTROPICALLY...THERE SHOULD BE 2 TO 3 UBAR/S OF UP GLIDE
OCCURRING ON THE 290K SURFACE. THIS SHOULD BE ENOUGH FORCING TO
PRODUCE A BAND OF LIGHT PRECIPITATION AHEAD OF THE SHORT WAVE
TROUGH AND WILL CONTINUE TO SHOW A BAND OF 60 TO 90 PERCENT
CHANCES WORKING WEST TO EAST ACROSS THE AREA TONIGHT. THE BIG
CONCERN WITH THIS PRECIPITATION IS WHAT TYPE IT WILL BE. THE
BUFKIT SOUNDINGS FROM BOTH THE NAM AND GFS CONTINUE TO SHOW A WARM
LAYER ALOFT WILL BE IN PLACE AS THE PRECIPITATION COMES IN TO
PRODUCE EITHER TOTAL OR PARTIAL MELTING FOR EITHER SOME FREEZING
DRIZZLE OR SLEET. EVAPORATIVE COOLING SHOULD WIPE OUT THIS WARM
LAYER WITHIN A COUPLE OF HOURS FOR A TRANSITION OVER TO LIGHT
SNOW. HOWEVER...THIS LIKELY WILL NOT CONTINUE VERY LONG BEFORE
THERE IS A LOSS OF ICE REINTRODUCING THE CHANCE FOR SOME FREEZING
DRIZZLE. THE ICE IN THE CLOUDS SHOULD MAINTAIN ITSELF LONGER OVER
THE NORTHERN SECTIONS TO KEEP THE PRECIPITATION AS LIGHT SNOW
UNTIL THE OVERNIGHT HOURS BEFORE POSSIBLY MIXING WITH SOME
FREEZING DRIZZLE. FORTUNATELY...WITH ONLY LIGHT PRECIPITATION
EXPECTED...ONLY SOME VERY LIGHT ICING MAY OCCUR. THE OTHER THING
THAT MAY MITIGATE THE ICING IS THE POTENTIAL FOR SURFACE
TEMPERATURES TO RISE AND REACH FREEZING OR ABOVE FOR AREAS
SOUTHWEST OF INTERSTATE 94. AT THIS POINT...DO NOT PLAN TO ISSUE A
WINTER WEATHER ADVISORY...BUT WILL SEND OUT A SPECIAL WEATHER
STATEMENT TO HEIGHTEN THE AWARENESS ALONG WITH A SHORT TERM
GRAPHIC CAST IMAGE.
A SECONDARY SHORT WAVE TROUGH WILL ROTATE AROUND THE UPPER LEVEL
LOW MONDAY AND PRODUCE WEAK PV ADVECTION IN THE 500-300 MB LAYER.
SOME WEAK QG CONVERGENCE SHOULD OCCUR IN THE 850-500 MB LAYER
ALONG WITH ABOUT 1 UBAR/S OF UP GLIDE ON THE 290K ISENTROPIC
SURFACE. THIS SHOULD BE ENOUGH TO MAINTAIN A CHANCE FOR SOME LIGHT
PRECIPITATION...ESPECIALLY IN THE INTERSTATE 94 CORRIDOR AND WILL
START THE DAY WITH 60 TO 70 PERCENT CHANCES GRADUALLY DECREASING
THROUGH THE DAY AS THE UPPER LEVEL LOW AND SHORT WAVE TROUGH MOVE
AWAY FROM THE AREA. STILL A CONCERN AS TO WHETHER THERE WILL BE
ICE IN THE CLOUDS AND WILL START WITH A LIGHT SNOW/FREEZING
DRIZZLE GOING TO EITHER FREEZING DRIZZLE OR DRIZZLE BASED ON
SURFACE TEMPERATURES. SOUTHWEST OF THIS AREA...THE LOW LEVEL LAPSE
RATES WILL BE INCREASING WITH VALUES OF 7 TO 10 KM/C BELOW 850 MB
BY AFTERNOON. THIS LOW LEVEL LAYER LOOKS TO BE SATURATED AND WITH
THE CYCLONIC FLOW...THERE SHOULD BE ENOUGH FORCING TO RING OUT
SOME LIGHT PRECIPITATION. FOR NOW...HAVE STAYED WITH FLURRIES AS
THE COLD AIR ADVECTION INCREASES...BUT CONCERNED THIS LAYER MAY
NOT BE COLD ENOUGH FOR ICE TO BE IN THE CLOUDS.
.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 221 PM CST SUN DEC 7 2014
RELATIVELY QUIET PERIOD EXPECTED AS HIGH PRESSURE SETS UP OVER THE
UPPER MIDWEST AND THEN REMAINS IN PLACE THROUGH THE END OF THE
WEEK. BOTH THE 07.12Z ECMWF AND GFS SHOW THE RIDGING WILL BEGIN TO
MOVE EAST OF THE REGION OVER THE UP COMING WEEKEND...BUT IT
REMAINS TO BE SEEN HOW FAST THIS WILL OCCUR. THE GFS IS QUICKER TO
DO THIS THAN EITHER THE ECMWF OR 07.12Z GEM. THE FASTER GFS THEN
ALLOWS A SHORT WAVE TROUGH TO COME OUT OF THE DEVELOPING SOUTHWEST
FLOW FOR SOME PRECIPITATION CHANCES SATURDAY NIGHT INTO SUNDAY.
WITH TEMPERATURES WARMING IN THE SOUTHWEST FLOW...THE BULK OF ANY
PRECIPITATION THAT FALLS MAY JUST BE RAIN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1135 PM CST SUN DEC 7 2014
MVFR TO LIFR CONDITIONS HAVE SPREAD ACROSS THE REGION WITH LSE AT
MVFR AND RST AT IFR AT THE MOMENT. CONDITIONS WILL STAY DOWN
OVERNIGHT AND SHOULD ACTUALLY GO DOWN A BIT WITH RST EXPECTED TO
BE LIFR AND LSE IFR. PRECIPITATION IS MAINLY OVER THOUGH SOME
DRIZZLE WILL BE POSSIBLE AHEAD OF A COLD FRONT THAT WILL MOVE
THROUGH LATER THIS MORNING. WINDS WILL COME AROUND TO THE
NORTHWEST AND BECOME GUSTY TO 20-25KTS WITH CIGS STAYING MVFR
THROUGH MONDAY EVENING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1039 PM CST SUN DEC 7 2014
.UPDATE...ISSUED A WINTER WEATHER ADVISORY FOR FREEZING RAIN AND
SLEET. THE COMBINATION OF COOLER AIR TEMPERATURES AND ROAD
TEMPERATURES BELOW FREEZING IN MOST LOCATIONS IN SOUTH CENTRAL
WISCONSIN MAKE THE POTENTIAL FOR WIDESPREAD GLAZING OF UNTREATED
ROADS HIGHER THAN POINTS WEST. RAP AND HRRR SOUNDINGS HAVE BEEN
LEANING MORE TOWARD A FREEZING RAIN/SLEET PROFILE VERSUS
SLEET/SNOW.
DID NOT ISSUE FOR SOUTHEAST AS RAP HAS BEEN TRENDING DOWNWARD WITH
QPF AS TROUGH MOVES EAST...FOCUSING MORE OVER EAST-CENTRAL WI...THEN
EXPANDS OVER SE WI BETWEEN 12Z AND 13Z. LOW CONFIDENCE AS TO
PCPN TYPE AND EXTENT SO NO HEADLINE...BUT WILL UPDATE SPS.
&&
.AVIATION/06Z TAFS/...LOOKING MORE LIKE A FREEZING RAIN/SLEET MIX
TO REACH KMSN BETWEEN 06Z AND 07Z AND LAST FOR 2-3 HOURS WITH MVFR
VSBYS AND IFR CIGS. THE MIXY PCPN WILL TRACK EAST REACHING KUES
BETWEEN 10Z AND 11Z...AND KMKE AND KENW TOWARD 12Z. UNCERTAINTY
WITH PCPN TYPE AT EASTERN SITES...BUT LOOKING MORE LIKE RAIN/SLEET
MIX WITH GLAZING POTENTIAL HINGING ON AIR AND SURFACE TEMPS AT
TIME OF PCPN...WITH WARMING AIR TEMPS JUST AHEAD OF THE SURFACE
TROUGH.
THE LOW CIGS WILL LINGER THROUGH THE FORECAST PERIOD AS MOISTURE
IS TRAPPED UNDER SUBSIDENCE INVERSION WITH CYCLONIC FLOW ALOFT.
NAM KEEPS CIGS AT IFR LEVELS WHILE GFS GUIDANCE RAISES THEM TO
MVFR DURING THE LATE AFTERNOON WEST AND EARLY EVENING EAST. WILL
TREND TOWARD THE MORE OPTIMISTIC SOLUTION.
&&
.MARINE...
NO CHANGE TO GOING SMALL CRAFT ADVISORY. STILL LOOKS LIKE WINDS
AND WAVES WILL BRIEFLY SUBSIDE FOR A TIME MONDAY AFTERNOON AND
EVENING...THEN NORTHWEST WINDS INCREASE LATER MONDAY EVENING
BUILDING WAVES BACK UP TO CRITERIA.
&&
.PREV DISCUSSION... /ISSUED 330 PM CST SUN DEC 7 2014/
TONIGHT AND MONDAY...CONFIDENCE - MEDIUM.
MAIN 500 MB SHORTWAVE TROUGH IS WELL DEFINED OVER NORTH DAKOTA...AND
IS EXPECTED TO SHIFT EASTWARD INTO NORTHERN MINNESOTA TONIGHT...THEN
TO THE NORTHEAST ON MONDAY. A VORTICITY MAXIMUM TO THE SOUTH OF THE
MAIN SHORTWAVE TROUGH WILL SLIDE EAST TOWARD THE AREA LATER
TONIGHT...THEN THROUGH THE AREA MONDAY MORNING. ANOTHER STRONGER
VORTICITY MAXIMUM WILL SHIFT SOUTHEAST THROUGH THE AREA DURING THE
AFTERNOON.
MODEST WARM AIR ADVECTION AREA...COMBINED WITH MODEST LOW TO MID
LEVEL FRONTOGENESIS RESPONSE BAND...IS EXPECTED TO COMBINE WITH THE
LEAD VORTICITY MAXIMUM TO PRODUCE A 4 TO 5 HOUR WINDOW OF MODERATE
TO STRONG UPWARD VERTICAL MOTION WEST TO EAST ACROSS THE AREA. THE
TIMING FOR THIS BAND WILL BE AROUND MIDNIGHT IN THE FAR WESTERN
COUNTIES...TO AROUND 09Z TO 10Z MONDAY FOR THE LAKESHORE COUNTIES.
AREA FORECAST SOUNDINGS ARE SHOWING SOME DIFFERENCES. THE GFS/ECMWF
ARE THE MOST CONSISTENT AND CONTINUE TO SUPPORT A PERIOD OF LIGHT
SNOW AND LIGHT SLEET MIX ACROSS THE AREA. THE NAM IS MILDER WITH ITS
WARM LAYER ABOVE THE SURFACE AND INDICATES SOME LIGHT FREEZING RAIN
MIXING IN AT TIMES. THE RAP SOUNDINGS ALSO LEAN IN THIS DIRECTION
SOMEWHAT. LEANED TOWARD THE MORE CONSISTENT GFS/ECMWF AND WENT WITH
PREVAILING LIGHT SNOW AND LIGHT SLEET LATER TONIGHT INTO EARLY
MONDAY. KEPT CHANCES FOR LIGHT FREEZING RAIN IN THE SOUTH...IN CASE
MILDER MODELS ARE CORRECT.
SHOULD SEE SNOW AND SLEET ACCUMULATIONS AROUND 1.0 INCH IN MOST
AREAS...A BIT MORE IN THE FAR NORTHERN COUNTIES AND LESS NEAR LAKE
MICHIGAN. HOURLY RATES OF 0.1 TO 0.3 INCHES PER HOUR ARE EXPECTED.
GIVEN TIMING DURING THE MORNING COMMUTE ON MONDAY...CONSIDERED A
WINTER WEATHER ADVISORY. AFTER COLLABORATION WITH NEIGHBORING
OFFICES...HELD OFF AND ISSUED A SPECIAL WEATHER STATEMENT. EVENING
SHIFT WILL NEED TO CONSIDER ONE...ESPECIALLY IF GFS LEANS TOWARD THE
NAM/RAP WITH LIGHT FREEZING RAIN POTENTIAL.
STRONGER 500 MB VORTICITY MAXIMUM DURING THE AFTERNOON WILL CONTINUE
TO BRING CHANCES FOR LIGHT RAIN AND LIGHT SNOW MONDAY. PERHAPS THE
PRECIPITATION WILL BECOME MORE LIGHT RAIN LATER IN THE DAY...AS
SURFACE TEMPERATURES WARM ABOVE FREEZING. LOWS TONIGHT SHOULD BE IN
THE UPPER 20S TO LOWER 30S...WITH MIDDLE TO UPPER 30S ON MONDAY.
MONDAY NIGHT THROUGH WEDNESDAY...CONFIDENCE - MEDIUM.
LINGERING WEAK LIFT AND LOW LEVEL RH MAY RESULT IN SOME LINGERING
FLURRIES OR DRIZZLE MONDAY EVENING BEFORE LOWER LEVELS FURTHER DRY.
WL CONTINUE LOW POPS FOR MEASUREABLE -RA/-SN IN THE EVE FOR THE FAR
EAST...CLOSER TO DEPARTING MID-LEVEL SHORT WAVE TROUGH.
OTHERWISE...SHORT WAVE RIDGING MOVES ACROSS WI LATER TUE INTO WED.
LOW LEVEL WINDS TURN MORE NORTHEAST FOR A TIME TUE/TUE NGT WITH
DELTA-T WITH DELTA-T INCREASING TO AROUND 6-7C. LOW LEVELS SLOWLY
WARM AT THIS TIME...AND SHORT TERM GUIDANCE IN DISAGREEMENT ON
AMOUNT OF VEERING OF WINDS DURING THIS PERIOD. HENCE WL HOLD OFF ON
ANY -SN OR FLURRY MENTION AT THIS TIME. TEMPERATURES REMAINING
CLOSE TO SEASONAL NORMAL THIS PERIOD.
WEDNESDAY NIGHT THROUGH SUNDAY...CONFIDENCE - MEDIUM.
A QUIET PERIOD EXPECTED THROUGH SATURDAY WITH SOME MODERATION IN
TEMPERATURES. 00Z ECMWF AND ECMWF MEAN TRENDING TOWARD SLOWER
NORTHWARD MOVEMENT OF LARGE LOW PRESSURE SYSTEM AFFECTING EAST COAST
EARLY IN THE PERIOD. IN FACT...APPEARS SYSTEM NOW TRENDING TOWARD
CUTOFF STATUS AND WILL SLOWLY WEAKEN OVER THE EAST COAST THRU THE
WEEKEND. OTHER MEDIUM RANGE GUIDANCE INCLUDING GFS AND GEM TRENDING
IN THIS DIRECTION. AS A RESULT...UPSTREAM LONG WAVE RIDGE OVER
CENTRAL CONUS INCLUDING WRN GTLAKES WL PERSIST A LITTLE LONGER...AT
LEAST THRU SAT. RIDGE LOOKS TO FINALLY SUCCUMB TO INTENSIFYING SHORT
WAVE FROM THE WRN CONUS LATE IN THE WEEKEND INTO MONDAY. HENCE BEST
THREAT FOR LIQUID PRECIP SUN NGT INTO MON. 925H TEMPS WARM FROM
AROUND -4C ON WED TO FLUCTUATE BTWN 2 AND 6C FROM THU THRU SUN.
LACK OF SNOW COVER HELPS...HOWEVER PENDING CLOUDS...DAYTIME TEMPS
LIKELY TO PEAK MOSTLY IN THE 40S...BEGINNING FRI.
ONE MINOR CONCERN EARLY IN THE PERIOD IS WHETHER ANY LAKE EFFECT
WOULD BE POSSIBLE AS CENTER OF HIGH PRESSURE PASSES BY TO THE NORTH.
ECMWF SHOWING MORE FAVORABLE ONSHORE FLOW IN THE LOW LEVELS WED NGT
BUT THEN BECOMES MORE NLY THU AND EVENTUALLY BACKS TO THE WEST TO
SOUTHWEST. DELTA-T LOOKS MARGINAL WED NGT SO WL HOLD OFF ON ANY
LAKE EFFECT PRECIP AT THIS TIME.
AVIATION/00Z TAFS/...
QUIET WEATHER CONTINUES INTO THIS EVENING...WITH MIDDLE TO HIGH
CLOUDS AND SOUTHEAST WINDS.
LIGHT SNOW AND LIGHT SLEET WILL MOVE THROUGH TAF SITES LATER TONIGHT
INTO EARLY MONDAY MORNING. MADISON SHOULD SEE THE PRECIPITATION
BETWEEN 07Z AND 08Z MONDAY...AND THE EASTERN TAF SITES BETWEEN 09Z
AND 10Z MONDAY. VISIBILITIES BELOW ALTERNATE MINIMUMS ARE
EXPECTED...WITH CEILINGS IN THE MVFR/IFR CATEGORY.
EXPECTING ABOUT A 4 TO 5 HOUR TIME PERIOD OF THIS LIGHT SNOW AND
LIGHT SLEET MIX...ENDING BY 14Z TO 15Z MONDAY. 1.0 TO 1.5 INCHES ARE
FORECAST AT MADISON...WITH 0.5 TO 1.0 INCH AT THE EASTERN SITES.
HOURLY RATES OF SNOW AND SLEET ACCUMULATION SHOULD RANGE FROM ABOUT
0.1 TO 0.3 INCHES. SOME LIGHT FREEZING RAIN MAY MIX IN AS WELL...BUT
LEFT OUT OF TAFS FOR NOW DUE TO LOWER CONFIDENCE.
AFTER THE MIX OF PRECIPITATION MOVES OUT OF THE AREA...THERE MAY BE
SOME LIGHT RAIN AND LIGHT SNOW LINGERING THROUGH THE REST OF THE
DAY. MVFR VISIBILITIES WITH CEILINGS BELOW ALTERNATE MINIMUMS ARE
ANTICIPATED. ANY ACCUMULATIONS LATER ON MONDAY WOULD BE A DUSTING AT
BEST. WINDS WILL GRADUALLY VEER FROM SOUTHWEST TO WEST.
MARINE...
TIGHTENING PRESSURE GRADIENT AHEAD OF APPROACHING SFC LOW PRESSURE
TROF WILL RESULT IN CONTINUED GUSTY SOUTHEAST WINDS TURNING TO THE
SOUTH TONIGHT INTO MONDAY. A LULL IN THE WINDS IS EXPECTED LATER
MON INTO MON EVE AS THE SFC TROF MOVES ACROSS THE NEAR SHORE WATERS.
EXPECT THE WINDS TO INCREASE ONCE AGAIN FROM THE NORTHWEST BEHIND
THE TROF MON NGT AS SOMEWHAT COLDER AIR SWEEPS ACROSS LAKE MICHIGAN
AND HIGH PRESSURE BUILDS INTO THE UPPER MIDWEST. HENCE STATUS QUO
ON ONGOING SMALL CRAFT ADVY THRU TUE.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY UNTIL 6 AM CST MONDAY FOR WIZ046-047-056-
057-062-063-067>069.
LM...SMALL CRAFT ADVISORY UNTIL 6 PM CST TUESDAY FOR LMZ643>646.
&&
$$
UPDATE...REM
TONIGHT/MONDAY AND AVIATION/MARINE...WOOD
MONDAY NIGHT THROUGH SUNDAY...MBK
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
915 AM EST MON DEC 8 2014
.DISCUSSION...
CURRENT-THIS AFTERNOON...EXPECTING LOW CLOUDS WITH SCATTERED LIGHT
TO MODERATE RAIN. CURRENT HIGHS LOOK GOOD GIVEN THE THICK AND LOW
CLOUDINESS PERSISTING ALL DAY.
PREVIOUS ZONES DISCUSSION
TODAY...MOSTLY CLOUDY AND DAMP WITH SCATTERED SHOWERS PRESSING
ONSHORE IN STOUT NE FLOW. GFS SHOWS EXPANDING AREA OF ISENTROPIC
LIFT OVER EC FL DURING THE DAY WHICH SUGGESTS PERSISTENT SHOWER
ACTIVITY OVER THE AREA SO WENT ABOVE GFS MOS POPS DRAWING 40-50
PERCENT ACROSS MOST OF THE AREA. CONDITIONS ARE NOT FAVORABLE FOR
DEEP CONVECTION (THUNDER). HIGH TEMPS WILL BE COOL ACROSS THE
NORTH INTERIOR IN THE UPPER 60S. MILDER CLOSER TO THE COAST IN
ONSHORE FLOW AND TO THE SOUTH IN THE LOW TO MID 70S.
LARGE LONG PERIOD NE SWELL WILL BE IMPACTING THE COAST TODAY AND
THIS HAS TRIGGERED A HIGH RISK OF RIP CURRENTS. THERE WILL BE
ROUGH SURF TOO ESP THIS MORNING ALONG THE VOLUSIA AND BREVARD
COASTS. BREAKING WAVES OF 5 TO 6 FEET MAY CAUSE MINOR BEACH
EROSION AROUND HIGH TIDE THIS MORNING. BUT HAVE DECIDED NOT TO
ISSUE A HIGH SURF ADVISORY SINCE THE WINDS WILL BE DECREASING THIS
AFTERNOON SOMEWHAT AND THE DIRECTION WILL BACK TO THE NORTH BY EVE
AND NW TONIGHT WHICH IS AN OFFSHORE FLOW. BUT THE DAY SHIFT WILL
REASSESS THIS.
TONIGHT...RAIN CHANCES WILL DIMINISH AS FLOW BACKS TO THE NORTH
AND SOME DRIER AIR ADVECTS INTO THE AREA BUT CLOUDS WILL BE SLOW
TO CLEAR. WILL KEEP A SLIGHT CHANCE FOR SHOWERS NEAR THE COAST
EARLY. LOW TEMPS REACHING THE UPPER 40S NORTH LAKE/VOLUSIA AND
50S ELSEWHERE.
TUE-WED...TROUGHING ALOFT WILL ENCOMPASS MUCH OF THE EASTERN
SEABOARD DURING THIS PERIOD. POST-FRONTAL CONDITIONS WITH NORTHWEST
WINDS NEAR 15 MPH DURING THE DAY ON TUE AND NEAR 10 MPH TUE NIGHT
WITH THE PRESSURE GRADIENT RELAXING A BIT BY WED. CONDITIONS LOOK TO
REMAIN DRY OVER LAND AND WILL NOT CARRY POPS...EXCEPT OVER THE
COASTAL WATERS EARLY IN THE PERIOD. HIGHS/LOWS WILL FALL TO BELOW
SEASONAL NORMALS. HIGHS MAINLY IN THE 60S ON TUE WITH 70 DEGREES
WITHIN REACH ALONG THE TREASURE COAST AND OKEECHOBEE COUNTY. MINS IN
THE 40S AREAWIDE TUE OVERNIGHT. TEMPERATURES ARE FORECAST TO REBOUND
INTO THE LOWER/MIDDLE 60S FOR WED. OVERNIGHT LOWS WED NIGHT WILL
FALL OFF INTO THE LOWER 40S MOST PLACES...EXCEPT UPPER 30S POSSIBLE
IN COOLER LOCATIONS ACROSS THE INTERIOR.
THU-SUN...ZONAL FLOW ALOFT OVER THE AREA WILL BECOME NORTHWEST LATE
SAT INTO SUN AHEAD OF SHORTWAVE RIDGING MOVING ACROSS THE GOMEX.
SURFACE HIGH PRESSURE WILL BUILD INTO THE AREA THROUGH THIS TIME.
INITIAL NORTHERLY FLOW WILL BECOME ONSHORE AGAIN THIS WEEKEND.
HIGHS/LOWS WILL REMAIN BELOW CLIMO THU-SAT WITH NEAR NORMAL
TEMPERATURES IN THE LOWER 70S FOR HIGHS AND 50S FOR LOWS RETURNING
AGAIN BY SUN. CONDITIONS MOSTLY DRY BUT MAY HAVE TO ENTERTAIN SOME
COASTAL SHOWERS LATER IN THE WEEKEND.
&&
.AVIATION...
CEILINGS/VISIBILITY BOUNCING ALL OVER THE PLACE. PREVAILING CEILINGS
HOVER AROUND THE MVFR/VFR BREAK POINT THE REST OF THE DAY WITH AN
OCCASIONAL/TEMPO IFR IN LIGHT RAIN AND/OR MIST/FOG ESPECIALLY ALONG
THE COAST WHERE THE PRECIPITATION IS COMING RIGHT OFF THE ATLANTIC.
OCCASIONAL MVFR/IFR VISIBILITY IN/VC SHOWERS/MIST/FOG.
PREVIOUS AVIATION DISCUSSION
EXPECT MAINLY MVFR/IFR CIGS THROUGH 15Z WITH SOME LIFR CIGS MCO
SOUTH. CIGS SHOULD LIFT TO VFR (040-060AGL) AFT 16Z ACROSS MUCH OF
THE AREA BUT SCATTERED SHRA MAY PRODUCE REPEATED LOWERING TO MVFR.
ANOTHER ROUND OF IFR CIGS EXPECTED AFT 06Z TONIGHT.
&&
.MARINE...
CURRENT MARINE CONDITIONS...
SAINT AUGUSTINE FISHING PIER CMAN SITE NORTH 32 KNOTS GUSTING TO 37
KNOTS 26KNOTS...BUOY 009 AT 20NM EAST OF CAPE CANAVERAL WAS
NORTHEAST AT 17 TO 21 KNOTS WITH 9 FOOT SEAS/7 FOOT NORTHEAST SWELL
WITH A 10 SECOND PERIOD. INSIDE PORT CANAVERAL TRIDENT PIER WAS
RECORDING NORTHEAST WINDS 5 TO 10 KNOTS 8AM/9AM. SEBASTIAN INLET WAS
RECORDING NORTH NORTHEAST AT 11 KNOTS AND THE TWO SCRIPPS BUOYS AT 4
AND 6NM OFF THE BEACH WERE RECORDING 5 TO 6 FOOT SEAS WITH 2 FOOT
SWELLS AND AN 11 SECOND PERIOD.
FOR THE AFTERNOON THE LATEST RUC RUN WAS INDICATING THAT THE WINDS
SHOULD DIMINISH FOR A WHILE THEN SHIFT TO THE NORTH AND INCREASE TO
20 KNOTS OR MORE AFTER MIDNIGHT AS THE NEXT WIND SURGE WORKS ITS WAY
DOWN THE COAST.
NOT PLANNING ANY SIGNIFICANT CHANGES TO THE ONGOING AFTERNOON
FORECAST.
PREVIOUS MARINE DISCUSSION
TODAY...LEADING EDGE OF NE WIND SURGE AND LONG PERIOD SWELL ARE
PUSHING S/SW ACROSS THE WATERS EARLY THIS MORNING. NOAA BUOY 009
RAMPED UP QUICKLY TO COMBINED SEAS OF 10 FT WITH 20-25 KNOTS.
THE WIND SURGE SHOULD REACH AT LEAST THE NORTHERN PORTION OF OUR
SOUTHERN (TREASURE COAST) MARINE ZONE BEFORE PRES GRAD RELAXES
THIS AFTN AND WINDS DECREASE SOME TEMPORARILY. BUT THE LARGE SWELL
COMPONENT...LIKELY ALREADY IMPACTING VOLUSIA COAST...WILL REACH
THE BREVARD AND TREASURE COASTS THIS MORNING AND PRODUCE HAZARDOUS
CONDITIONS NEAR INLETS FOR SMALL CRAFT. A SMALL CRAFT ADVISORY IS
IN EFFECT FOR ALL MARINE ZONES.
TONIGHT...LOW PRESSURE DEVELOPING WELL OFFSHORE THE CAROLINA COAST
TODAY WILL DEEPEN AS IT LIFTS NORTH. THIS WILL BACK THE WINDS OUT
OF THE NORTH BY THIS EVE AND N/NW OVERNIGHT WITH AN INCREASE IN
SPEED. SEAS WILL BUILD TO 11 FT IN THE GULF STREAM...6 TO 9 FEET
NEARSHORE.
TUE-WED...POOR TO HAZARDOUS BOATING CONDITIONS AS A SMALL CRAFT
ADVISORY FOR BOATERS GREETS THIS PERIOD. GUSTY NW WINDS BEHIND THE
LATEST FRONT WILL INCREASE SUSTAINED WIND SPEEDS TO AROUND 20 KTS
OVER THE OPEN ATLC TUE-TUE NIGHT WITH THE PRESSURE GRADIENT SLOWLY
RELAXING WED-WED NIGHT. SEAS 6-9 FT NEAR SHORE AND UP TO 12 FT
OFFSHORE. LOCAL MODELS CONTINUE TO INDICATE POSSIBLE 12-14 FT SEAS
OVER THE GULF STREAM WHICH COULD ALSO PROMPT A HIGH SURF ADVISORY
ALONG THE EAST COAST. FORTUNATELY THE WIND DIRECTION WILL BE
OFFSHORE (FROM THE NW) WHICH SHOULD HELP LIMIT THE BREAKING WAVES AT
THE COAST BUT MINOR BEACH EROSION WILL BE POSSIBLE.
THU-FRI...DECREASING WINDS AND SUBSIDING SEAS THROUGH THIS PERIOD AS
HIGH PRESSURE BUILDS BACK INTO THE AREA.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 69 51 65 44 / 30 10 10 0
MCO 72 52 68 45 / 40 10 10 0
MLB 73 58 69 45 / 50 20 10 0
VRB 74 58 71 47 / 50 20 10 0
LEE 68 48 65 44 / 20 10 10 0
SFB 71 51 68 45 / 30 10 10 0
ORL 71 52 67 47 / 40 10 10 0
FPR 74 58 71 48 / 50 20 10 10
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY UNTIL 10 PM EST TUESDAY FOR COASTAL WATERS
FROM FLAGLER BEACH TO VOLUSIA BREVARD COUNTY LINE OUT 20 NM-
COASTAL WATERS FROM VOLUSIA BREVARD COUNTY LINE TO
SEBASTIAN INLET OUT 20 NM.
SMALL CRAFT ADVISORY UNTIL 7 PM EST WEDNESDAY FOR COASTAL WATERS
FROM SEBASTIAN INLET TO JUPITER INLET OUT 20 NM-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.
&&
$$
IMPACT WX...GLITTO
PUBLIC SV...JOHNSON
FORECASTS...WIMMER
AREA FORECAST DISCUSSION
NWS MIAMI FL
627 AM EST MON DEC 8 2014
.AVIATION...
RECENTLY ANIMATED IR2 IMAGERY SHOWED A LARGE SHIELD OF LOW STRATUS
ACROSS MUCH OF SOUTH FLORIDA ACROSS THE INTERIOR AND GULF REGIONS.
AT THIS TIME...IT APPEARS THE MAIN ISSUE FROM THIS STRATUS DECK
WILL BE MVFR/IFR CIGS, ESPECIALLY OVER APF AND PBI. THIS DECK
SHOULD BEGIN TO LIFT AND BURN OFF THROUGH THE MID-MORNING PERIOD
WITH A RETURN OF VFR CONDITIONS. WINDS WILL REMAIN LIGHT OUT OF
THE NNW TODAY THEN NE AT SITE APF LATER TONIGHT INTO TUESDAY
MORNING. /85
&&
.PREV DISCUSSION... /ISSUED 406 AM EST MON DEC 8 2014/
SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH TONIGHT...USHERING IN AN EXTENDED
PERIOD OF NORTHWEST WINDS AND BELOW NORMAL TEMPERATURES. HIGH
PRESSURE WILL DOMINATE.
SHORT TERM /TODAY THROUGH WEDNESDAY/ ...
BEHIND YESTERDAYS COLD FRONT...TEMPS EARLY THIS MORNING ARE QUITE
A BIT COOLER THAN PREV FEW MORNINGS...WITH LOW 60S ALONG THE
COASTS AND 50S ELSEWHERE. LOW STRATUS/SOME VSBY RESTRICTIONS IS
PUSHING SOUTHWARD INTO GLADES AND HENDRY COUNTIES. HOW FAR SOUTH
THIS CLOUD LAYER ADVANCES IS UNCERTAIN...BUT IT APPEARS THAT AT
LEAST NORTH OF A NAPLES TO BOCA RATON LINE...MOSTLY CLOUDY
CONDITIONS WILL PREVAIL INTO LATE MORNING. NW WINDS WILL TURN NE
THIS AFTERNOON...AND TEMPERATURES SHOULD RISE TO NEAR
NORMAL...MID/UPR 70S. NE FLOW WILL BRING SOME LOW-LEVEL MOISTURE
DOWN THE E FL COASTLINE...AND THIS COULD BE ENOUGH TO BRING INLAND
A FEW SHOWERS INTO PALM BEACH COUNTY. THESE MAY CONTINUE INTO
EARLY TUESDAY...BEFORE A COLD FRONT BRINGS MUCH DRIER AIR INTO THE
REGION. MINIMA TONIGHT WILL ALSO BE NEAR AVERAGE FOR EARLY
DECEMBER...MAINLY IN THE MID/UPR 50S...WITH SOME LOW 60S ACROSS
THE EASTERN METROPOLITAN AREAS.
A POTENT SHORTWAVE TROUGH WILL DIVE THROUGH THE GREAT LAKES TODAY
AND INTO THE CENTRAL APPALACHIANS TONIGHT. BEHIND THE
TROUGH...CANADIAN HIGH PRESSURE WILL EXPAND THROUGH THE PLAINS AND
EVENTUALLY THE MISSISSIPPI RIVER VALLEY. THE TROUGHS ATTENDANT
SURFACE CDFNT WILL MOVE THROUGH THE OHIO VALLEY TODAY...WHILE
SURFACE LOPRES DEVELOPS OFF CAROLINAS. THE LOW WILL ACCELERATE THE
ARRIVAL OF THE FRONT INTO SOUTH FLORIDA AND ALSO INCREASE THE
COLD-AIR ADVECTION ASSOCIATED WITH IT. SIGNIFICANT COOLING WILL
OCCUR BY TUESDAY NIGHT AS THE UPPER TROUGH AXIS QUIETLY PASSES
BY. MINIMAS SHOULD REACH 40S OVER THE INTERIOR...WITH LOW 50S ALL
THE WAY TO THE EAST COAST. WIND CHILL VALUES WILL BE A FEW DEGREES
LOWER THAN THE TEMPERATURE OVERNIGHT. WEDNESDAY...CANADIAN RIDGE
BECOMES MORE ENTRENCHED OVER SOUTH FLORIDA...AND MAXIMA WILL HOLD
IN THE 60S.
SIGNIFICANT NE SWELL BEING TO ARRIVE IN SOUTH FLORIDA WATERS
TODAY /SEE DETAILS IN THE MARINE DISCUSSION BELOW/. THIS WILL LEAD
TO SIGNIFICANT RIP CURRENTS ALONG ATLANTIC BEACHES THROUGH AT
LEAST MID-WEEK. IN ADDITION...HIGH SURF MAY WARRANT AN ADVISORY
TUESDAY OR WEDNESDAY...AND BEACH EROSION/MINOR COASTAL
FLOODING...ARE ALSO POTENTIAL HAZARDOUS.
LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/ ...
AFOREMENTIONED SHORTWAVE TROUGH WILL DEEPEN FURTHER AND EVOLVED
INTO CLOSED H5 LOPRES OVER NE CONUS. THE FEATURE WILL THEN
STALL...AT LEAST INTO THE WEEKEND. MEANWHILE...EXPANSIVE SFC
RIDGE WILL REMAIN CENTERED NORTHWEST OF THE STATE. FOR SOUTH
FLORIDA...THIS MEANS EXPECT AN EXTENDED PERIOD OF NORTHWEST WINDS
WITH A COOL CANADIAN AIRMASS CONTINUING TO FILTER IN MUCH OF THE
WEEK. SKIES WILL BE MAINLY CLEAR. OVERNIGHT LOWS SHOULD MAINLY BE
IN 40S INTERIOR/50S METROPOLTIAN AREAS...WITH DAYTIME HIGHS IN THE
UPPER 60S TO LOW 70S. ALTHOUGH LONG-RANGE MODELS GENERALLY AGREE
ON THIS PATTERN CONTINUING INTO THE WEEKEND...LATEST ECMWF RUN
BRINGS ADDITIONAL REINFORCEMENTS OF COOL AIR DOWN THE PENINSULA.
IF THIS PANS OUT...FORECAST TEMPERATURES MAY BE SEVERAL DEGREES TO
WARM FOR THE END OF THE WEEK.
AVIATION...
STILL MONITORING A SHIELD OF LOW CIGS PUSHING SOUTH ACROSS THE
CENTRAL FLORIDA PENINSULA PER THE LATEST MICRON SATELLITE IMAGERY.
THE TIMING AND EXACT EXTENT OF THE SOUTHERN PROPAGATION OF THIS
SHIELD REMAINS IN QUESTION. LATEST HRRR AND SREF CIG HEIGHT
PROBABILITIES KEEP THE MAJORITY OF THE LOW CIGS ACROSS THE
INTERIOR WITH THE PERIPHERY OF WHICH EXTENDING TO BOTH THE
ATLANTIC AND GULF COASTS...POSSIBLY AFFECTING THE TAF SITES. KEPT
ANY MVFR/IFR CIGS OUT OF TAFS FOR NOW DUE TO UNCERTAINTY BUT WILL
CONTINUE TO MONITOR AND AMEND AS NECESSARY. OTHERWISE...LIGHT
NORTH-NORTHWESTERLY FLOW WILL PREVAIL AT THE EAST COAST SITES
THROUGH THE MORNING WITH NORTHEASTERLY FLOW AT KAPF.
MARINE...
IMPRESSIVE FETCH GENERATED BY LOPRES WEST OF BERMUDA IS BRINGING
NELY SWELL DOWN THE FLORIDA PENINSULA EARLY THIS MORNING. WAVE
HEIGHTS ARE ALREADY EXCEEDING 10 FT OFFSHORE THE MELBOURNE/CAPE
CANAVERAL AREA...AND WILL LIKELY REACH WATERS OFF PALM BEACH
COUNT THIS AFTERNOON...THEN THE REMAINDER OF ATLANTIC WATERS
TONIGHT. SMALL CRAFT ADVISORIES HAVE BEEN ISSUED ACCORDINGLY. THE
5 TO 8 FOOT SWELL WILL PERSIST TUESDAY INTO WEDNESDAY...LEADING TO
A CONTINUATION OF HAZARDOUS MARINE CONDITIONS. WAVES IN THE GULF
STREAM MAY EXCEED 13 FEET DURING THIS TIME.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 76 61 73 50 / 30 10 10 0
FORT LAUDERDALE 78 62 75 54 / 10 0 10 0
MIAMI 78 62 75 53 / 10 0 0 0
NAPLES 74 58 71 50 / 10 0 0 0
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 7 PM EST TUESDAY
FOR AMZ651-671.
SMALL CRAFT ADVISORY UNTIL 7 PM EST TUESDAY FOR AMZ650-670.
GM...NONE.
&&
$$
SHORT TERM...10/CD
LONG TERM....23/SK
AVIATION...10/CD
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1026 AM EST MON DEC 8 2014
.UPDATE...
ISSUED AT 1025 AM EST MON DEC 8 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW SHORTWAVE TROF MOVING INTO
THE WESTERN GREAT LAKES. RIBBON OF 850-700MB MOISTURE TRANSPORT IN
CONCERT WITH ISENTROPIC ASCENT ENHANCED BY 850MB WINDS OF 40-45KT
AND DEEP LAYER QVECTOR CONVERGENCE AHEAD OF TROF IS SUPPORTING A
BAND OF MODERATE TO HEAVY SNOW OVER THE EASTERN 4 COUNTIES OF THE
CWA. THE BAND IS MOVING ALONG FAIRLY RAPIDLY FROM WEST TO EAST
DRIVEN BY 40 KT WSW WINDS AT MID-LVLS AHEAD OF THE SHORTWAVE TROUGH
SO EXPECT PERIOD OF MODERATE TO HEAVY SNOW TO LAST LESS THAN AN HOUR
OVER MOST LOCATIONS. BUT AS THE SNOW BAND MOVES THROUGH IT COULD
DROP A QUICK 1-2 INCHES OF SNOW. AS A RESULT OF THIS HEAVIER SNOW
BAND DECIDED TO ISSUE STORM TERM WINTER WX ADVISORIES FOR THE 4 ERN
COUNTIES TO HIGHLIGHT THE BRIEF INTENSITY OF THE SNOW AND
SNOW-COVERED AND SLIPPERY ROADS INTO EARLY AFTERNOON. SNOW WILL
TAPER OFF QUICKLY TO FLURRIES BEHIND THIS MAIN BAND AS BEST MOISTURE
AND ISENTROPIC ASCENT SHIFTS EAST.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 534 AM EST MON DEC 8 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW SHORTWAVE TROF MOVING INTO
THE WESTERN GREAT LAKES. RIBBON OF 850-700MB MOISTURE TRANSPORT IN
CONCERT WITH ISENTROPIC ASCENT ENHANCED BY 850MB WINDS OF 40-45KT
AND DEEP LAYER QVECTOR CONVERGENCE AHEAD OF TROF IS SUPPORTING A
BAND OF SNOW THAT IS SHIFTING E ACROSS THE FCST AREA. AS OF 10Z...
BAND OF SNOW RUNS FROM MENOMINEE TO ESCANABA TO MUNISING. TO THE W
SNOW DIMINISHES...AND THERE MAY BE SOME PATCHY -FZDZ AS WELL THOUGH
WITH SNOW ALREADY ON THE ROADS...ANY -FZDZ SHOULDN`T CONTRIBUTE TO
MAKING ROADS ANY MORE SLIPPERY THAN THEY ALREADY ARE. CLOSE TO
APPROACHING VORT MAX...ANOTHER AREA OF SNOW IS SPREADING ACROSS NW
WI/WRN LAKE SUPERIOR INTO FAR WRN UPPER MI.
BAND OF HEAVIER SNOW CURRENTLY PUSHING INTO THE ERN FCST AREA WILL
CONTINUE TO SHIFT E IN CONCERT WITH TRANSLATING RIBBON OF MOISTURE
TRANSPORT/ISENTROPIC ASCENT. THIS BAND OF SNOW WILL LIKELY SHIFT OUT
OF THE FCST AREA LATE MORNING/EARLY AFTN...AND SNOW ACCUMULATIONS
WILL BE MOSTLY ON THE ORDER 1.5-2.5 INCHES. OTHERWISE...EXPECT AREAS
OF -SN TODAY (ACCUMULATIONS MOSTLY 1 INCH OR LESS) AS TROF MOVES
INTO THE UPPER LAKES. HOWEVER...SNOW WILL LIKELY BE MORE WIDESPREAD
DURING THE MORNING HRS IN ASSOCIATION WITH VORT MAX MOVING ACROSS
WRN UPPER MI. ALTHOUGH IT`S A MILD START TO THE DAY...CLOUDS WILL
KEEP TEMPS FROM RISING MUCH. HIGH WILL BE IN THE LOW TO MID 30S.
N TO NW WINDS STRENGTHEN BEHIND DEPARTING LOW PRES TONIGHT. COOLING
LOW-LEVEL AIR MASS WILL SUPPORT SOME LAKE ENHANCEMENT FOR A TIME.
HOWEVER...SNOWFALL IS ONLY EXPECTED TO BE LIGHT FOR SEVERAL REASONS.
850MB TEMPS ARE MARGINAL FOR ENHANCEMENT WHILE DEEPER MOISTURE IS
AROUND...LOW-LEVEL FLOW IS NOT STRONGLY CYCLONIC...AND DGZ IS ABOVE
THE UPWARD MOTION AND MOST OF THE DEEPER MOISTURE FOR THAT MATTER.
UPSLOPING WILL BE A MAIN COMPONENT AIDING SNOWFALL...AND WHERE THAT
IS MAXIMIZED...EXPECT 1-2 INCHES OF SNOW TONIGHT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 340 AM EST MON DEC 8 2014
SHARP UPPER TROUGH WILL BE E OF THE CWA BY 12Z TUE AS A 1034MB SFC
RIDGE IS JUST W OF THE CWA. WINDS WILL START THE DAY TUE OUT OF THE
N WITH 850MB TEMPS AROUND -8C...WHICH IS NOT COLD ENOUGH FOR PURE
LES. HAVE QUICKLY DIMINISHING POPS ON TUE AS UPSLOPE PRECIP WILL
DIMINISH AS THE SFC RIDGE MOVES IN. DO NOT EXPECT MORE THAT A HALF
INCH OF ADDITIONAL SNOW ON TUE.
TUE NIGHT THROUGH SAT WILL SEE AN UPPER RIDGE BUILDING INTO THE
REGION...WHICH WILL LEAD TO MOSTLY DRY AND WARMER TEMPERATURES.
SHOULD STILL SEE COLD NIGHTS TUE NIGHT AND WED NIGHT AS LOWS
APPROACH 0F...ESPECIALLY WED NIGHT. HIGH TEMPS WILL BE WARMEST FRI
AND SAT /ESPECIALLY SAT/ AND WILL BE IN THE LOW 40S IN PLACES BOTH
DAYS. MODELS HAVE BEEN HINTING AT A SHORTWAVE MOVING INTO THE REGION
ON SAT. WHILE THIS IS NOT CERTAIN BY ANY MEANS...DID SHOW A SUBTLE
INCREASE IN POPS ON SUN. ALSO...KEPT FOG IN THE FORECAST FOR SAT
NIGHT AND SUN AS HIGHER DEW POINTS SPREAD INTO THE AREA OVER A
SLOWLY MELTING SNOW PACK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 637 AM EST MON DEC 8 2014
LOW PRES SYSTEM SETTLING INTO THE UPPER GREAT LAKES WILL RESULT IN
POOR CONDITIONS WITH OCNL -SN AT KIWD/KCMX/KSAW THRU THIS FCST
PERIOD. WHILE CONDITIONS WILL INITIALLY VARY BTWN MVFR AND IFR...IFR
SHOULD BECOME THE PREVAILING CONDITION AT ALL TERMINALS BY AFTN. IFR
CONDITIONS SHOULD PERSIST TONIGHT WITH SNOW PICKING UP FOR A TIME
UNDER STRENGTHENING UPSLOPE N TO NW WINDS. THERE MAY BE SOME
IMPROVEMENT AT KCMX LATE AS USPLOPING DIMINISHES.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 534 AM EST MON DEC 8 2014
PRES GRADIENT WILL WEAKEN TODAY AS LOW PRES OVER FAR SE MANITOBA
MOVES E...PASSING ACROSS NORTHERN AND EASTERN LAKE SUPERIOR LATE
THIS AFTN AND EVENING. AS A RESULT...WINDS WILL DIMINISH ACROSS LAKE
SUPERIOR TODAY WITH GALES OVER THE ERN LAKE ENDING BY MID MORNING.
BEHIND THE LOW...N TO NW WINDS WILL RAMP UP TONIGHT...AIDED BY PRES
RISES APPROACHING FROM THE NW. MAGNITUDE OF PRES RISES SUGGESTS
POTENTIAL FOR A FEW HRS WHEN WINDS MAY GUST TO NEAR 35KT FROM NCNTRL
TO SCNTRL LAKE SUPERIOR. WINDS WILL DIMINISH FROM W TO E TUE AS HIGH
PRES RIDGE APPROACHES. WITH THE HIGH PRES RIDGE ARRIVING OVER THE
UPPER LAKES TUE NIGHT/WED...LIGHTER WINDS UNDER 20KT ARE EXPECTED...
AND THESE LIGHTER WINDS SHOULD LINGER ON THRU THU AND POSSIBLY FRI
AS WELL.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR MIZ006-014-085.
WINTER WEATHER ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR MIZ007.
WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR MIZ013.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...VOSS
SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
638 AM EST MON DEC 8 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 534 AM EST MON DEC 8 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW SHORTWAVE TROF MOVING INTO
THE WESTERN GREAT LAKES. RIBBON OF 850-700MB MOISTURE TRANSPORT IN
CONCERT WITH ISENTROPIC ASCENT ENHANCED BY 850MB WINDS OF 40-45KT
AND DEEP LAYER QVECTOR CONVERGENCE AHEAD OF TROF IS SUPPORTING A
BAND OF SNOW THAT IS SHIFTING E ACROSS THE FCST AREA. AS OF 10Z...
BAND OF SNOW RUNS FROM MENOMINEE TO ESCANABA TO MUNISING. TO THE W
SNOW DIMINISHES...AND THERE MAY BE SOME PATCHY -FZDZ AS WELL THOUGH
WITH SNOW ALREADY ON THE ROADS...ANY -FZDZ SHOULDN`T CONTRIBUTE TO
MAKING ROADS ANY MORE SLIPPERY THAN THEY ALREADY ARE. CLOSE TO
APPROACHING VORT MAX...ANOTHER AREA OF SNOW IS SPREADING ACROSS NW
WI/WRN LAKE SUPERIOR INTO FAR WRN UPPER MI.
BAND OF HEAVIER SNOW CURRENTLY PUSHING INTO THE ERN FCST AREA WILL
CONTINUE TO SHIFT E IN CONCERT WITH TRANSLATING RIBBON OF MOISTURE
TRANSPORT/ISENTROPIC ASCENT. THIS BAND OF SNOW WILL LIKELY SHIFT OUT
OF THE FCST AREA LATE MORNING/EARLY AFTN...AND SNOW ACCUMULATIONS
WILL BE MOSTLY ON THE ORDER 1.5-2.5 INCHES. OTHERWISE...EXPECT AREAS
OF -SN TODAY (ACCUMULATIONS MOSTLY 1 INCH OR LESS) AS TROF MOVES
INTO THE UPPER LAKES. HOWEVER...SNOW WILL LIKELY BE MORE WIDESPREAD
DURING THE MORNING HRS IN ASSOCIATION WITH VORT MAX MOVING ACROSS
WRN UPPER MI. ALTHOUGH IT`S A MILD START TO THE DAY...CLOUDS WILL
KEEP TEMPS FROM RISING MUCH. HIGH WILL BE IN THE LOW TO MID 30S.
N TO NW WINDS STRENGTHEN BEHIND DEPARTING LOW PRES TONIGHT. COOLING
LOW-LEVEL AIR MASS WILL SUPPORT SOME LAKE ENHANCEMENT FOR A TIME.
HOWEVER...SNOWFALL IS ONLY EXPECTED TO BE LIGHT FOR SEVERAL REASONS.
850MB TEMPS ARE MARGINAL FOR ENHANCEMENT WHILE DEEPER MOISTURE IS
AROUND...LOW-LEVEL FLOW IS NOT STRONGLY CYCLONIC...AND DGZ IS ABOVE
THE UPWARD MOTION AND MOST OF THE DEEPER MOISTURE FOR THAT MATTER.
UPSLOPING WILL BE A MAIN COMPONENT AIDING SNOWFALL...AND WHERE THAT
IS MAXIMIZED...EXPECT 1-2 INCHES OF SNOW TONIGHT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 340 AM EST MON DEC 8 2014
SHARP UPPER TROUGH WILL BE E OF THE CWA BY 12Z TUE AS A 1034MB SFC
RIDGE IS JUST W OF THE CWA. WINDS WILL START THE DAY TUE OUT OF THE
N WITH 850MB TEMPS AROUND -8C...WHICH IS NOT COLD ENOUGH FOR PURE
LES. HAVE QUICKLY DIMINISHING POPS ON TUE AS UPSLOPE PRECIP WILL
DIMINISH AS THE SFC RIDGE MOVES IN. DO NOT EXPECT MORE THAT A HALF
INCH OF ADDITIONAL SNOW ON TUE.
TUE NIGHT THROUGH SAT WILL SEE AN UPPER RIDGE BUILDING INTO THE
REGION...WHICH WILL LEAD TO MOSTLY DRY AND WARMER TEMPERATURES.
SHOULD STILL SEE COLD NIGHTS TUE NIGHT AND WED NIGHT AS LOWS
APPROACH 0F...ESPECIALLY WED NIGHT. HIGH TEMPS WILL BE WARMEST FRI
AND SAT /ESPECIALLY SAT/ AND WILL BE IN THE LOW 40S IN PLACES BOTH
DAYS. MODELS HAVE BEEN HINTING AT A SHORTWAVE MOVING INTO THE REGION
ON SAT. WHILE THIS IS NOT CERTAIN BY ANY MEANS...DID SHOW A SUBTLE
INCREASE IN POPS ON SUN. ALSO...KEPT FOG IN THE FORECAST FOR SAT
NIGHT AND SUN AS HIGHER DEW POINTS SPREAD INTO THE AREA OVER A
SLOWLY MELTING SNOW PACK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 637 AM EST MON DEC 8 2014
LOW PRES SYSTEM SETTLING INTO THE UPPER GREAT LAKES WILL RESULT IN
POOR CONDITIONS WITH OCNL -SN AT KIWD/KCMX/KSAW THRU THIS FCST
PERIOD. WHILE CONDITIONS WILL INITIALLY VARY BTWN MVFR AND IFR...IFR
SHOULD BECOME THE PREVAILING CONDITION AT ALL TERMINALS BY AFTN. IFR
CONDITIONS SHOULD PERSIST TONIGHT WITH SNOW PICKING UP FOR A TIME
UNDER STRENGTHENING UPSLOPE N TO NW WINDS. THERE MAY BE SOME
IMPROVEMENT AT KCMX LATE AS USPLOPING DIMINISHES.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 534 AM EST MON DEC 8 2014
PRES GRADIENT WILL WEAKEN TODAY AS LOW PRES OVER FAR SE MANITOBA
MOVES E...PASSING ACROSS NORTHERN AND EASTERN LAKE SUPERIOR LATE
THIS AFTN AND EVENING. AS A RESULT...WINDS WILL DIMINISH ACROSS LAKE
SUPERIOR TODAY WITH GALES OVER THE ERN LAKE ENDING BY MID MORNING.
BEHIND THE LOW...N TO NW WINDS WILL RAMP UP TONIGHT...AIDED BY PRES
RISES APPROACHING FROM THE NW. MAGNITUDE OF PRES RISES SUGGESTS
POTENTIAL FOR A FEW HRS WHEN WINDS MAY GUST TO NEAR 35KT FROM NCNTRL
TO SCNTRL LAKE SUPERIOR. WINDS WILL DIMINISH FROM W TO E TUE AS HIGH
PRES RIDGE APPROACHES. WITH THE HIGH PRES RIDGE ARRIVING OVER THE
UPPER LAKES TUE NIGHT/WED...LIGHTER WINDS UNDER 20KT ARE EXPECTED...
AND THESE LIGHTER WINDS SHOULD LINGER ON THRU THU AND POSSIBLY FRI
AS WELL.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 10 AM EST THIS MORNING FOR LSZ266-267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
534 AM EST MON DEC 8 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 534 AM EST MON DEC 8 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW SHORTWAVE TROF MOVING INTO
THE WESTERN GREAT LAKES. RIBBON OF 850-700MB MOISTURE TRANSPORT IN
CONCERT WITH ISENTROPIC ASCENT ENHANCED BY 850MB WINDS OF 40-45KT
AND DEEP LAYER QVECTOR CONVERGENCE AHEAD OF TROF IS SUPPORTING A
BAND OF SNOW THAT IS SHIFTING E ACROSS THE FCST AREA. AS OF 10Z...
BAND OF SNOW RUNS FROM MENOMINEE TO ESCANABA TO MUNISING. TO THE W
SNOW DIMINISHES...AND THERE MAY BE SOME PATCHY -FZDZ AS WELL THOUGH
WITH SNOW ALREADY ON THE ROADS...ANY -FZDZ SHOULDN`T CONTRIBUTE TO
MAKING ROADS ANY MORE SLIPPERY THAN THEY ALREADY ARE. CLOSE TO
APPROACHING VORT MAX...ANOTHER AREA OF SNOW IS SPREADING ACROSS NW
WI/WRN LAKE SUPERIOR INTO FAR WRN UPPER MI.
BAND OF HEAVIER SNOW CURRENTLY PUSHING INTO THE ERN FCST AREA WILL
CONTINUE TO SHIFT E IN CONCERT WITH TRANSLATING RIBBON OF MOISTURE
TRANSPORT/ISENTROPIC ASCENT. THIS BAND OF SNOW WILL LIKELY SHIFT OUT
OF THE FCST AREA LATE MORNING/EARLY AFTN...AND SNOW ACCUMULATIONS
WILL BE MOSTLY ON THE ORDER 1.5-2.5 INCHES. OTHERWISE...EXPECT AREAS
OF -SN TODAY (ACCUMULATIONS MOSTLY 1 INCH OR LESS) AS TROF MOVES
INTO THE UPPER LAKES. HOWEVER...SNOW WILL LIKELY BE MORE WIDESPREAD
DURING THE MORNING HRS IN ASSOCIATION WITH VORT MAX MOVING ACROSS
WRN UPPER MI. ALTHOUGH IT`S A MILD START TO THE DAY...CLOUDS WILL
KEEP TEMPS FROM RISING MUCH. HIGH WILL BE IN THE LOW TO MID 30S.
N TO NW WINDS STRENGTHEN BEHIND DEPARTING LOW PRES TONIGHT. COOLING
LOW-LEVEL AIR MASS WILL SUPPORT SOME LAKE ENHANCEMENT FOR A TIME.
HOWEVER...SNOWFALL IS ONLY EXPECTED TO BE LIGHT FOR SEVERAL REASONS.
850MB TEMPS ARE MARGINAL FOR ENHANCEMENT WHILE DEEPER MOISTURE IS
AROUND...LOW-LEVEL FLOW IS NOT STRONGLY CYCLONIC...AND DGZ IS ABOVE
THE UPWARD MOTION AND MOST OF THE DEEPER MOISTURE FOR THAT MATTER.
UPSLOPING WILL BE A MAIN COMPONENT AIDING SNOWFALL...AND WHERE THAT
IS MAXIMIZED...EXPECT 1-2 INCHES OF SNOW TONIGHT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 340 AM EST MON DEC 8 2014
SHARP UPPER TROUGH WILL BE E OF THE CWA BY 12Z TUE AS A 1034MB SFC
RIDGE IS JUST W OF THE CWA. WINDS WILL START THE DAY TUE OUT OF THE
N WITH 850MB TEMPS AROUND -8C...WHICH IS NOT COLD ENOUGH FOR PURE
LES. HAVE QUICKLY DIMINISHING POPS ON TUE AS UPSLOPE PRECIP WILL
DIMINISH AS THE SFC RIDGE MOVES IN. DO NOT EXPECT MORE THAT A HALF
INCH OF ADDITIONAL SNOW ON TUE.
TUE NIGHT THROUGH SAT WILL SEE AN UPPER RIDGE BUILDING INTO THE
REGION...WHICH WILL LEAD TO MOSTLY DRY AND WARMER TEMPERATURES.
SHOULD STILL SEE COLD NIGHTS TUE NIGHT AND WED NIGHT AS LOWS
APPROACH 0F...ESPECIALLY WED NIGHT. HIGH TEMPS WILL BE WARMEST FRI
AND SAT /ESPECIALLY SAT/ AND WILL BE IN THE LOW 40S IN PLACES BOTH
DAYS. MODELS HAVE BEEN HINTING AT A SHORTWAVE MOVING INTO THE REGION
ON SAT. WHILE THIS IS NOT CERTAIN BY ANY MEANS...DID SHOW A SUBTLE
INCREASE IN POPS ON SUN. ALSO...KEPT FOG IN THE FORECAST FOR SAT
NIGHT AND SUN AS HIGHER DEW POINTS SPREAD INTO THE AREA OVER A
SLOWLY MELTING SNOW PACK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1210 AM EST MON DEC 8 2014
SNOW AHEAD OF AN APPROACHING LOW PRES SYSTEM WILL MOVE THROUGH THE
WEST HALF OF UPPER MI OVERNIGHT. ALL TERMINALS ARE EXPECTED TO FALL
TO MVFR. WITH A BRIEF PERIOD OF SOMEWHAT HEAVIER SNOW...THERE SHOULD
ALSO BE A PERIOD OF IFR VIS. LOOK FOR ALL SITES TO LOWER TO IFR CIGS
THIS MORNING AS LOW-LVL MOISTURE GETS TRAPPED UNDER A LOWERING
INVERSION. THE IFR CIGS SHOULD PERSIST THROUGH THE AFTERNOON. AS
WINDS VEER TO THE NW BEHIND THE LOW...SOME LAKE AND UPSLOPE ENHANCED
SNOW WILL BE POSSIBLE...MAINLY AT IWD/CMX. OTHERWISE...PERSISTENT LOW
LEVEL MOISTURE WILL MAINTAIN THE IFR CIGS THROUGH THE EVENING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 534 AM EST MON DEC 8 2014
PRES GRADIENT WILL WEAKEN TODAY AS LOW PRES OVER FAR SE MANITOBA
MOVES E...PASSING ACROSS NORTHERN AND EASTERN LAKE SUPERIOR LATE
THIS AFTN AND EVENING. AS A RESULT...WINDS WILL DIMINISH ACROSS LAKE
SUPERIOR TODAY WITH GALES OVER THE ERN LAKE ENDING BY MID MORNING.
BEHIND THE LOW...N TO NW WINDS WILL RAMP UP TONIGHT...AIDED BY PRES
RISES APPROACHING FROM THE NW. MAGNITUDE OF PRES RISES SUGGESTS
POTENTIAL FOR A FEW HRS WHEN WINDS MAY GUST TO NEAR 35KT FROM NCNTRL
TO SCNTRL LAKE SUPERIOR. WINDS WILL DIMINISH FROM W TO E TUE AS HIGH
PRES RIDGE APPROACHES. WITH THE HIGH PRES RIDGE ARRIVING OVER THE
UPPER LAKES TUE NIGHT/WED...LIGHTER WINDS UNDER 20KT ARE EXPECTED...
AND THESE LIGHTER WINDS SHOULD LINGER ON THRU THU AND POSSIBLY FRI
AS WELL.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 10 AM EST THIS MORNING FOR LSZ266-267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...JLB
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
543 AM CST MON DEC 8 2014
.UPDATE...
ISSUED AT 536 AM CST MON DEC 8 2014
UPDATED TO INCLUDE 12Z AVIATION DISCUSSION BELOW.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 329 AM CST MON DEC 8 2014
CURRENT CONDITIONS SYNOPSIS...
LATEST SURFACE ANALYSIS SHOWS LOW PRESSURE NORTHWEST OF
INTERNATIONAL FALLS... WITH A COLD FRONT TRAILING SOUTH THROUGH
SOUTHWEST MINNESOTA. WATER VAPOR IMAGERY AND RAP UPPER AIR ANALYSIS
SHOW AN INITIAL SHORTWAVE PUSHING THROUGH EASTERN MINNESOTA AT THE
CURRENT TIME... WITH A SECONDARY WAVE DROPPING INTO EASTERN NORTH
DAKOTA. THIS SECOND WAVE WILL HELP PUSH THE AFOREMENTIONED SURFACE
LOW AND FRONTAL BOUNDARY EAST ACROSS THE AREA THIS MORNING... WITH
THE FRONT QUICKLY WORKING THROUGH WISCONSIN BY AFTERNOON. EXTENSIVE
LOW CLOUDS WERE PRESENT ACROSS THE STATE... WITH LAYERED CLOUDS
ASSOCIATED WITH THE UPPER WAVE HELPING TO PRODUCE SOMEWHAT MORE
MEANINGFUL RETURNS ON RADAR NORTH OF I-94 WHERE SOME LIGHT
ACCUMULATING SNOW HAS OCCURRED. LOW CLOUDS EXTEND WELL UPSTREAM
THROUGH NORTH DAKOTA AND INTO MANITOBA AND SASKATCHEWAN.
FORECAST ITEM/S/ OF CONCERN...
LINGERING LIGHT PCPN IS THE PRIMARY FORECAST CONCERN. SOME MIXED
PCPN CONTINUES ACROSS THE AREA GIVEN THE LACK OF SATURATION AND
PRESENCE OF ONLY LIQUID WATER WITHIN CLOUDS OVER MUCH OF THE CENTRAL
AND SOUTHERN PORTION OF THE AREA. THIS IS RESULTING IN SOME
MIST/DRIZZLE... WHICH IS LEADING TO SOME LIGHT ICING IN LOCATIONS
WHERE TEMPERATURES ARE BELOW FREEZING OR WHERE UNTREATED GROUND
TEMPERATURES ARE SUB-FREEZING. THE DEEPER MOISTURE AND LAYERED
CLOUDS OVER THE NORTHERN PART OF THE AREA ARE HELPING TO SEED THINGS
WITH ICE CRYSTALS AND ALLOWING FOR MORE IN THE WAY OF LIGHT SNOWFALL
ACROSS THE NORTHERN PART OF THE AREA. HOWEVER... THE BEST FORCING
ASSOCIATED WITH THE UPPER WAVE CONTINUES TO PUSH EAST... SO ANY
LINGERING PCPN TODAY WILL MAINLY BE DRIVEN BY LOW LEVEL CYCLONIC
FLOW AND A FAIRLY SHALLOW DEPTH OF LIFT. PCPN TYPE COULD REMAIN AN
ISSUE... ALTHOUGH THE NAM AND GFS SUGGEST WE SHOULD HAVE JUST ENOUGH
DEPTH OF MOISTURE THROUGH THE DAY FOR ANY PCPN TO BE MAINLY SNOW
GIVEN THE COLDER TEMPERATURES MOVING IN ALOFT. LOOKING UPSTREAM
THERE IS MINIMAL PCPN BEING REPORTED IN THE STRATOCU AREA... WITH
PCPN MAINLY BENEATH THE UPPER COLD POOL.
MODEL DISCUSSION/PREFERENCES...
DO NOT HAVE A STRONG PREFERENCE FOR ANY PARTICULAR SOLUTION IN THE
SHORT TERM... SO STUCK WITH A COMPROMISE OF HRRR... NAM... RAP...
AND HOPWRF SOLUTIONS. THESE ALL POINT TOWARD MAINLY CLOUDY SKIES
TODAY AND TONIGHT... WITH DRIER AIR TRYING TO WORK IN TOWARD THE END
OF THAT PERIOD TO SCOUR OUT THE LOWER CLOUDS.
SENSIBLE WEATHER EXPECTATIONS...
THE BULK OF THE PCPN SHOULD CONTINUE TO SHIFT EAST TODAY AS THE
INITIAL SHORTWAVE EXITS AND THE SECONDARY WAVE QUICKLY ROTATES
THROUGH THE AREA. HOWEVER... CYCLONIC BOUNDARY LAYER FLOW AND THE
PRESENCE OF THE UPPER TROUGH SHOULD KEEP SOME CHANCE OF PCPN GOING
FOR MUCH OF THE DAY OVER THE NORTHERN AND EASTERN PORTION OF THE
AREA. CAN/T RULE OUT SOME ADDITIONAL LIGHT MIXED PCPN... ALTHOUGH
THE GENERAL TENDENCY SHOULD BE FOR MORE IN THE WAY OF SNOWFLAKES
THAN ANYTHING ELSE WHERE PCPN OCCURS.
DETAILED DISCUSSION FOR ITEM/S/ OF CONCERN...
VERTICAL PROFILES WILL DETERMINE PCPN TYPE THROUGH THE DAY TODAY...
AND FORECAST SOUNDINGS SUGGEST SOME CHANCE FOR FZDZ OR LIGHT
FREEZING RAIN AT TIMES WITH DRIER AIR IN THE MID-LEVELS AND A LOSS
OF ICE CRYSTALS. HOWEVER... PCPN WILL CONTINUE TO BE ON THE
DOWNSWING... SO ANY ADDITIONAL ACTIVITY SHOULD BE LIMITED IN ITS
OCCURRENCE. HIGH PRESSURE WILL BUILD IN FROM THE NORTHWEST
TONIGHT... WORKING TO BRING ANY LINGERING PCPN TO AN END AS
SUBSIDENCE FINALLY WORKS TO SCOUR OUT THE CLOUD COVER FROM WEST TO
EAST.
FORECAST CONFIDENCE/UNCERTAINTY...
CONFIDENCE IS MODERATE TO HIGH IN THE PRESENCE OF CLOUDY SKIES TODAY
INTO THIS EVENING... WITH LOW TO MODERATE CONFIDENCE THAT CLOUDS
WILL BREAK UP LATER TONIGHT. THERE IS MODERATE TO HIGH CONFIDENCE
THAT LIGHT PCPN WILL CONTINUE TO IMPACT THE NORTHEAST AND EASTERN
PORTION OF THE AREA INTO THIS AFTERNOON... WITH CONFIDENCE OF PCPN
OCCURRENCE DECREASING TO THE SOUTH AND WEST. THERE IS LOW CONFIDENCE
IN THE EXACT TIMING AND LOCATION OF ADDITIONAL MIXED PCPN IN THE
FORM OF FREEZING DRIZZLE.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 329 AM CST MON DEC 8 2014
BIGGEST QUESTION DURING THE LONG TERM STILL REVOLVES AROUND HOW WARM
CAN WE GET FRIDAY AND SATURDAY...WHICH REALLY MEANS THAT QUESTION IS
HOW MUCH STRATUS DO WE SEE THEN. NO MAJOR PRECIP MAKERS LOOK TO
IMPACT THE AREA...WITH ONLY SOME LIGHT RAIN EXPECTED WITH A COLD
FRONT PASSING THROUGH THE AREA FOR THE SECOND HALF OF THE WEEKEND.
MEDIUM RANGE MODELS CONTINUE TO SHOW A SIGNIFICANT PATTERN SHIFT
COMMENCING THIS WEEK...AS THE DEEP UPPER LOWS AND ASSOCIATED ARCTIC
AIRMASSES SHIFT TO THE EAST BY ABOUT 60 DEGS OF LONGITUDE. THIS WILL
PUSH THE ARCTIC OFF INTO THE NORTH ATLANTIC AND EASTERN ASIA...WITH
MUCH OF THE NORTH AMERICAN LAND MASS REMAINING ARCTIC AIRMASS
FREE...WITH ABOUT THE ONLY COLD AIR OVER THE CONUS BY THE WEEKEND
BEING FOUND UNDER THE UPPER LOW THAT WILL BE CLOSING OFF OVER THE
EAST COAST BY THE END OF THE WEEK.
THE LONG TERM WILL START WITH A MOISTURE STARVED UPPER LOW WORKING
FROM NODAK INTO CENTRAL IOWA TUESDAY INTO TUESDAY NIGHT. AT THE
SFC... A BETTER THAN 1032MB SW-NE ORIENTED RIDGE WILL BE WORKING
ACROSS THE UPPER MS VALLEY...HENCE WHY THE UPPER WAVE IS MOISTURE
STARVED IN THE LOW LEVELS. TUESDAY WILL BE THE COLDEST DAY OF THE
WEEK BY FAR...WITH TEMPERATURES REMAINING IN THE 20S...BUT TUESDAY
NIGHT...WE GET ON THE BACKSIDE OF THE HIGH...WITH SRLY FLOW SETTING
UP FROM WEDNESDAY INTO SUNDAY. AS THESE SRLY WINDS BLOW...AN
IMPRESSIVE H5 RIDGE WILL BE BUILDING INTO THE UPPER MS VALLEY. BY
SATURDAY ALL MED RANGE MODELS SHOW H5 HEIGHTS EXCEEDING 570
DM...WHICH WOULD BE SOME OF THE HIGHEST H5 HEIGHTS EVER OBSERVED IN
THE MONTH OF DECEMBER IN THE COMBINED STC/MPX SOUNDING
HISTORY...WHICH DATES BACK TO 1948. TO GO WITH THAT...THE ECMWF
CONTINUES TO SHOW H85 TEMPS FRIDAY/SATURDAY BUILDING TO BETWEEN +12C
AND +16C. LIKE THE H5 HEIGHTS...H85 TEMPS THIS HIGH ARE BASICALLY AT
THE OBSERVED MAX IN DECEMBER FOR STC/MPX.
TO GO ALONG WITH THESE IMPRESSIVE H5 HEIGHTS AND H85 TEMPS...WE WILL
BE SEEING OUR DEWP TEMPS SURGE INTO AT LEAST THE 40S...WITH THE
ECMWF ACTUALLY BRINGING 50 DEGREE DEWPS ALL THE WAY UP TO I-94 ON
SATURDAY. EVEN IF WE ONLY SEE DEWPS IN THE MID 40S...THAT WOULD BE
ABOUT 15 DEGREES HIGHER THAN THE NORMAL HIGH. THE MAJORITY OF THE
TIME WHEN DEWPS IN THE WINTER EXCEED THE NORMAL HIGHS BY THAT MUCH
IT MEANS A DAY FULL OF FOG AND STRATUS...AND THAT CERTAINLY LOOKS TO
BE THE CASE ON SATURDAY. FRIDAY MAY AVOID THE STRATUS AND GO ABOUT
MOSTLY SUNNY...BUT SATURDAY NIGHT...WHEN THE 40+ DEWPS GET
HERE...THEY LOOK TO COME WITH PLENTY OF LOW STRATUS. WHAT DOES ALL
THAT MEAN...WELL IT WILL PROBABLY BE TOUGH TO REACH RECORD HIGH MAX
TEMPS /51 TO 53/...BUT WE SHOULD HAVE NO PROBABLY SETTING SOME NEW
RECORD WARM MINIMUMS OVER THE WEEKEND. SUNDAY...A COLD FRONT WILL
WORK ACROSS THE MPX AREA...BUT LOOKS TO COME THROUGH LATE ENOUGH TO
GIVE ALL BE WRN MN ONE MORE DAY WITH HIGHS IN THE 40S BEFORE
TEMPERATURES COOL BACK CLOSER TO NORMAL.
FOR PRECIP...THE ATMO LOOKS TO REMAIN TOO DRY FOR ANYTHING UNTIL THE
COLD FROM STARTS MOVING INTO WRN MN SATURDAY NIGHT. MOISTURE
TRANSPORT AND ISENTROPIC ASCENT AHEAD OF THE FRONT LOOK TO BE ENOUGH
TO GENERATE SOME LIGHT PRECIP. GFS FORECAST SOUNDINGS WOULD SAY WE
LACK ICE CRYSTALS...WITH PRIMARY TYPE BE DZ THROUGH THE
WEEKEND...THOUGH WITH TEMPERATURES AS WARM AS THEY ARE FORECAST TO
BE...P-TYPE LIKELY WILL NOT BE MUCH OF AN ISSUE...IT WILL BE ALL
DZ/RA UNTIL AFTER THE COLD FRONT PASSES.
ALTHOUGH IT DOES COOL DOWN BEHIND THE FRONT...BOTH THE GFS/ECMWF ARE
IN GOOD AGREEMENT WITH THE DOOR TO THE ARCTIC REMAINING FIRMLY SHUT
FOR US FOR THE NEXT 10 DAYS...WITH THE FIRST HALF OF DECEMBER
LOOKING TO START OFF ON A VERY MILD NOTE AFTER A VERY COLD DAY 1.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 536 AM CST MON DEC 8 2014
COLD FRONT IS CURRENTLY TRAVERSING THE FORECAST AREA. VISIBILITIES
ARE GENERALLY IMPROVING IN THE WAKE OF THE FRONT WITH DRIZZLE
ENDING IN MOST LOCATIONS AS WINDS SHIFT TO THE WEST AND NORTHWEST
AND PICK UP. HOWEVER... LOW CLOUDS EXTEND WELL TO THE WEST AND
NORTHWEST OF THE FRONT... SO WILL CONTINUE TO CONTEND WITH SOME
IFR AND LIFR CONDITIONS FOR A GOOD PART OF THE DAY. CEILINGS ARE
IMPROVING SOMEWHAT BACK ACROSS NORTH DAKOTA... AND EVENTUALLY
EXPECT TO SEE THAT OCCUR FROM WEST TO EAST ACROSS THE AREA. FEEL
THE NAM IS A BIT TOO PESSIMISTIC IN TERMS OF LOW LEVEL MOISTURE
AND CLOUD COVER LATER THIS AFTERNOON AND TONIGHT... AND TRENDED
MORE TOWARD THE GFS BEYOND 03Z. HOWEVER... CONFIDENCE IS FAIRLY
LOW OVERALL AND WOULD EXPECT IT TO BE A DAY WITH NO SHORTAGE OF
AMENDMENTS.
KMSP...OVERALL TREND HIGHLIGHTED IN THE TAF IS EXPECTED... BUT
TIMING OF CEILING AND VISIBILITY IMPROVEMENTS COULD CERTAINLY VARY
BY A FEW HOURS... AS COULD THE ACTUAL CEILING HEIGHTS LATER THIS
AFTERNOON INTO TONIGHT. MOST OF THE LIGHT PCPN SHOULD BE ENDING
SHORTLY... ALTHOUGH SOME SCATTERED FLURRIES WITH NO IMPACT ON
VISIBILITY COULD OCCUR THROUGH THE DAY.
/OUTLOOK FOR KMSP/
TUESDAY AFTERNOON THROUGH WEDNESDAY NIGHT...VFR. SOUTHEAST WIND
LESS THAN 10 KT BECOMING SOUTH WEDNESDAY.
THURSDAY THROUGH FRIDAY...MVFR OR IFR CEILINGS POSSIBLE. SOUTH TO
SOUTHWEST WIND 5 TO 15 KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
UPDATE...
SHORT TERM...
LONG TERM...MPG
AVIATION...
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1004 AM CST MON DEC 8 2014
.UPDATE...
ISSUED AT 1005 AM CST MON DEC 8 2014
MAIN CHALLENGE THIS MORNING WILL BE CLOUD COVER AND TEMPERATURES.
WIDESPREAD STRATUS BEHIND THE EXITING LOW PRESSURE SYSTEM
EXTENDING FROM NORTHWEST THROUGH CENTRAL AND EASTERN NORTH DAKOTA.
COLD HIGH PRESSURE BUILDING SOUTH IS CLEARING OUT THE STRATUS OVER
THE NORTH CENTRAL...AND WILL CONTINUE TO ERODE NORTH TO SOUTH
THROUGH THE DAY. WITH THE CLEAR SKIES NORTH...TEMPERATURES ARE
ACTUALLY FALLING WITH THE LOSS OF CLOUD COVER AND COLD ADVECTION.
UPDATED CLOUD COVER KEEPING CLOUDS THROUGH THE MORNING MOST AREAS
AND CLEARING FROM NORTH TO SOUTH. ALSO ADJUSTED TEMPERATURES WITH
STEADY OR FALLING TEMPERATURES NORTH TO RISING SLIGHTLY OVER THE
SOUTHWEST.
UPDATE ISSUED AT 640 AM CST MON DEC 8 2014
UPDATED THE FORECAST TO INDICATE OVERCAST SKIES OVER NORTHWESTERN
AND CENTRAL NORTH DAKOTA THIS MORNING. THE STRATUS SHOULD BEGIN TO
ERODE LATER THIS AFTERNOON. IN THE MEANTIME...TEMPERATURES UNDER
THE STRATUS DECK SHOULD HOLD STEADY THROUGH MID-DAY...THEN COULD
BEGIN TO INCREASE AS CLOUDS BREAK UP LATER THIS AFTERNOON. UPDATED
THE TEMPERATURE GRIDS TO REFLECT THIS SCENARIO AS A RESULT.
UPDATE ISSUED AT 522 AM CST MON DEC 8 2014
QUICK UPDATE TO INCREASE CLOUD COVER WEST AND REMOVE PATCHY FOG.
THE STRATUS DECK ACROSS SOUTHERN SASKATCHEWAN HAS TAKEN A MORE
SOUTHERLY JOG WITHIN THE PAST COUPLE OF HOURS. THIS WILL PUT MOST
OF WESTERN NORTH DAKOTA UNDER CLOUDY SKIES THROUGH THE EARLY
MORNING HOURS. DUE TO INCREASED CLOUD COVER AND PERSISTENT WEST
WINDS...REMOVED THE POTENTIAL FOR PATCHY FOG ACROSS THE WEST.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 234 AM CST MON DEC 8 2014
THE MAIN FOCUS FOR THE SHORT TERM IS CLOUD COVER AND TEMPERATURES.
THE LOW PRESSURE RESPONSIBLE FOR THE LIGHT SNOW LAST NIGHT
CONTINUES TO PUSH OUT OF NORTH DAKOTA THIS MORNING. THE LOW IS
DRAGGING AN AREA OF LOW STRATUS IN ITS WAKE. THE STRATUS HAS BEEN
CONFINED TO ALONG AND EAST OF THE MISSOURI RIVER SO FAR. THERE IS
A POSSIBILITY THAT THE STRATUS WILL EXTEND A LITTLE FURTHER WEST
THIS MORNING BEFORE IT BEGINS CLEARING FROM WEST TO EAST BY THIS
AFTERNOON. THE LATEST HRRR RUN INDICATES CLOUD COVER COULD ENTER
WILLISTON WITHIN THE NEXT COUPLE OF HOURS.
THE STRATUS WILL WREAK HAVOC ON TEMPERATURES EARLY THIS
MORNING...INTO THE AFTERNOON HOURS. AREAS UNDER THE STRATUS WILL
SEE LITTLE CHANGE IN TEMPERATURES WITH SLIGHTLY WARMER READINGS
EARLY THIS MORNING AND SLIGHTLY COOLER READINGS FOR DAYTIME HIGHS.
WHILE AREAS UNDER CLEAR SKIES WILL HAVE AN EASIER TIME REBOUNDING
FROM OVERNIGHT LOWS. THIS IS REFLECTED IN THE HIGH TEMPERATURE
FORECAST FOR TODAY WITH 30S EXPECTED ACROSS THE CLEAR SOUTHWEST
AND TEENS/20S EXPECTED ACROSS THE NORTHERN JAMES VALLEY.
OVERALL A RATHER PLEASANT DAY IS EXPECTED AS WINDS WILL CONTINUE
TO DIMINISH AND SKIES SLOWLY CLEAR THROUGH THE DAY.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 234 AM CST MON DEC 8 2014
BROAD UPPER LEVEL RIDGING IS FORECAST BUILD INTO THE REGION
THROUGH THE END OF THE WEEK...THEN BEGIN TO BREAK DOWN OVER THE
WEEKEND.
FOR TUESDAY...A RIDGE-RUNNER SHORTWAVE IS FORECAST TO TRAVERSE
NORTH DAKOTA. EVEN THOUGH UPPER LEVEL SUPPORT SHOULD BE STRONG
ENOUGH TO GENERATE ELEVATED SNOW SHOWERS...THE MODEL SOUNDINGS
INDICATE THAT A DRY THERMODYNAMIC PROFILE UP TO 600MB WILL BE IN
PLACE. THEREFORE...VIRGA WILL LIKELY BE OBSERVED TUESDAY.
HOWEVER...WOULD NOT BE SURPRISED IF A FEW FLAKES REACHED THE
SURFACE SOUTHWEST OF THE MISSOURI RIVER TUESDAY. DUE TO THE STRONG
UPPER FORCING BUT DRY BOUNDARY LAYER CONDITIONS...HANDLED THIS
SCENARIO WITH SILENT POPS IN THE GRIDS FOR NOW.
THE UPPER RIDGE IS FORECAST TO SHARPEN OVER THE NORTHERN PLAINS
WEDNESDAY THROUGH FRIDAY...WITH FRIDAY FORECAST TO BE THE WARMEST
DAY OF THE EXTENDED. FRIDAY FORECAST HIGH TEMPERATURES RANGE FROM
THE UPPER 30S TO UPPER 40S.
THE UPPER RIDGE IS PROGGED TO BEGIN TO BREAK DOWN SATURDAY AS A
LONG WAVE TROUGH ENTERS THE ROCKIES. THE MAIN ENERGY FROM THE
TROUGH IS GENERALLY FORECAST TO MOVE EAST INTO NORTH DAKOTA
SATURDAY NIGHT INTO SUNDAY. WILL CONTINUE TO BROAD BRUSH A SLIGHT
CHANCE OF SNOW SATURDAY NIGHT/SUNDAY GIVEN THE MODEL TO MODEL AND
RUN TO RUN INCONSISTENCIES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1005 AM CST MON DEC 8 2014
WIDESPREAD MVFR AND OCCASIONAL IFR CONDITIONS ARE LIKELY ACROSS
ALL TAF SITES THROUGH THE MORNING HOURS. PERSISTENT STRATUS AT
KISN/KDIK/KBIS/KJMS. CLEARING FROM NORTH TO SOUTH WITH KMOT
CLEARING SOON. REMAINING TAFS CLEARING DURING THE AFTERNOON.
HAS INCREASED
WESTWARD AND NOW ENCOMPASSES KISN AND KDIK. LOW CIGS WILL CLEAR
OUT OF KISN/KDIK LATER THIS MORNING AND KMOT/KBIS/KJMS LATER THIS
AFTERNOON.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TWH
SHORT TERM...AJ
LONG TERM...TM
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
641 AM CST MON DEC 8 2014
.UPDATE...
ISSUED AT 640 AM CST MON DEC 8 2014
UPDATED THE FORECAST TO INDICATE OVERCAST SKIES OVER NORTHWESTERN
AND CENTRAL NORTH DAKOTA THIS MORNING. THE STRATUS SHOULD BEGIN TO
ERODE LATER THIS AFTERNOON. IN THE MEANTIME...TEMPERATURES UNDER
THE STRATUS DECK SHOULD HOLD STEADY THROUGH MID-DAY...THEN COULD
BEGIN TO INCREASE AS CLOUDS BREAK UP LATER THIS AFTERNOON. UPDATED
THE TEMPERATURE GRIDS TO REFLECT THIS SCENARIO AS A RESULT.
UPDATE ISSUED AT 522 AM CST MON DEC 8 2014
QUICK UPDATE TO INCREASE CLOUD COVER WEST AND REMOVE PATCHY FOG.
THE STRATUS DECK ACROSS SOUTHERN SASKATCHEWAN HAS TAKEN A MORE
SOUTHERLY JOG WITHIN THE PAST COUPLE OF HOURS. THIS WILL PUT MOST
OF WESTERN NORTH DAKOTA UNDER CLOUDY SKIES THROUGH THE EARLY
MORNING HOURS. DUE TO INCREASED CLOUD COVER AND PERSISTENT WEST
WINDS...REMOVED THE POTENTIAL FOR PATCHY FOG ACROSS THE WEST.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 234 AM CST MON DEC 8 2014
THE MAIN FOCUS FOR THE SHORT TERM IS CLOUD COVER AND TEMPERATURES.
THE LOW PRESSURE RESPONSIBLE FOR THE LIGHT SNOW LAST NIGHT
CONTINUES TO PUSH OUT OF NORTH DAKOTA THIS MORNING. THE LOW IS
DRAGGING AN AREA OF LOW STRATUS IN ITS WAKE. THE STRATUS HAS BEEN
CONFINED TO ALONG AND EAST OF THE MISSOURI RIVER SO FAR. THERE IS
A POSSIBILITY THAT THE STRATUS WILL EXTEND A LITTLE FURTHER WEST
THIS MORNING BEFORE IT BEGINS CLEARING FROM WEST TO EAST BY THIS
AFTERNOON. THE LATEST HRRR RUN INDICATES CLOUD COVER COULD ENTER
WILLISTON WITHIN THE NEXT COUPLE OF HOURS.
THE STRATUS WILL WREAK HAVOC ON TEMPERATURES EARLY THIS
MORNING...INTO THE AFTERNOON HOURS. AREAS UNDER THE STRATUS WILL
SEE LITTLE CHANGE IN TEMPERATURES WITH SLIGHTLY WARMER READINGS
EARLY THIS MORNING AND SLIGHTLY COOLER READINGS FOR DAYTIME HIGHS.
WHILE AREAS UNDER CLEAR SKIES WILL HAVE AN EASIER TIME REBOUNDING
FROM OVERNIGHT LOWS. THIS IS REFLECTED IN THE HIGH TEMPERATURE
FORECAST FOR TODAY WITH 30S EXPECTED ACROSS THE CLEAR SOUTHWEST
AND TEENS/20S EXPECTED ACROSS THE NORTHERN JAMES VALLEY.
OVERALL A RATHER PLEASANT DAY IS EXPECTED AS WINDS WILL CONTINUE
TO DIMINISH AND SKIES SLOWLY CLEAR THROUGH THE DAY.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 234 AM CST MON DEC 8 2014
BROAD UPPER LEVEL RIDGING IS FORECAST BUILD INTO THE REGION
THROUGH THE END OF THE WEEK...THEN BEGIN TO BREAK DOWN OVER THE
WEEKEND.
FOR TUESDAY...A RIDGE-RUNNER SHORTWAVE IS FORECAST TO TRAVERSE
NORTH DAKOTA. EVEN THOUGH UPPER LEVEL SUPPORT SHOULD BE STRONG
ENOUGH TO GENERATE ELEVATED SNOW SHOWERS...THE MODEL SOUNDINGS
INDICATE THAT A DRY THERMODYNAMIC PROFILE UP TO 600MB WILL BE IN
PLACE. THEREFORE...VIRGA WILL LIKELY BE OBSERVED TUESDAY.
HOWEVER...WOULD NOT BE SURPRISED IF A FEW FLAKES REACHED THE
SURFACE SOUTHWEST OF THE MISSOURI RIVER TUESDAY. DUE TO THE STRONG
UPPER FORCING BUT DRY BOUNDARY LAYER CONDITIONS...HANDLED THIS
SCENARIO WITH SILENT POPS IN THE GRIDS FOR NOW.
THE UPPER RIDGE IS FORECAST TO SHARPEN OVER THE NORTHERN PLAINS
WEDNESDAY THROUGH FRIDAY...WITH FRIDAY FORECAST TO BE THE WARMEST
DAY OF THE EXTENDED. FRIDAY FORECAST HIGH TEMPERATURES RANGE FROM
THE UPPER 30S TO UPPER 40S.
THE UPPER RIDGE IS PROGGED TO BEGIN TO BREAK DOWN SATURDAY AS A
LONG WAVE TROUGH ENTERS THE ROCKIES. THE MAIN ENERGY FROM THE
TROUGH IS GENERALLY FORECAST TO MOVE EAST INTO NORTH DAKOTA
SATURDAY NIGHT INTO SUNDAY. WILL CONTINUE TO BROAD BRUSH A SLIGHT
CHANCE OF SNOW SATURDAY NIGHT/SUNDAY GIVEN THE MODEL TO MODEL AND
RUN TO RUN INCONSISTENCIES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 640 AM CST MON DEC 8 2014
WIDESPREAD MVFR AND OCCASIONAL IFR CONDITIONS ARE LIKELY ACROSS
ALL TAF SITES THROUGH THE EARLY MORNING HOURS. PERSISTENT STRATUS
AT KMOT/KBIS/KJMS HAS INCREASED WESTWARD AND NOW ENCOMPASSES KISN
AND KDIK. LOW CIGS WILL CLEAR OUT OF KISN/KDIK LATER THIS MORNING
AND KMOT/KBIS/KJMS LATER THIS AFTERNOON.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TM
SHORT TERM...AJ
LONG TERM...TM
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS BISMARCK ND
522 AM CST MON DEC 8 2014
.UPDATE...
ISSUED AT 522 AM CST MON DEC 8 2014
QUICK UPDATE TO INCREASE CLOUD COVER WEST AND REMOVE PATCHY FOG.
THE STRATUS DECK ACROSS SOUTHERN SASKATCHEWAN HAS TAKEN A MORE
SOUTHERLY JOG WITHIN THE PAST COUPLE OF HOURS. THIS WILL PUT MOST
OF WESTERN NORTH DAKOTA UNDER CLOUDY SKIES THROUGH THE EARLY
MORNING HOURS. DUE TO INCREASED CLOUD COVER AND PERSISTENT WEST
WINDS...REMOVED THE POTENTIAL FOR PATCHY FOG ACROSS THE WEST.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 234 AM CST MON DEC 8 2014
THE MAIN FOCUS FOR THE SHORT TERM IS CLOUD COVER AND TEMPERATURES.
THE LOW PRESSURE RESPONSIBLE FOR THE LIGHT SNOW LAST NIGHT
CONTINUES TO PUSH OUT OF NORTH DAKOTA THIS MORNING. THE LOW IS
DRAGGING AN AREA OF LOW STRATUS IN ITS WAKE. THE STRATUS HAS BEEN
CONFINED TO ALONG AND EAST OF THE MISSOURI RIVER SO FAR. THERE IS
A POSSIBILITY THAT THE STRATUS WILL EXTEND A LITTLE FURTHER WEST
THIS MORNING BEFORE IT BEGINS CLEARING FROM WEST TO EAST BY THIS
AFTERNOON. THE LATEST HRRR RUN INDICATES CLOUD COVER COULD ENTER
WILLISTON WITHIN THE NEXT COUPLE OF HOURS.
THE STRATUS WILL WREAK HAVOC ON TEMPERATURES EARLY THIS
MORNING...INTO THE AFTERNOON HOURS. AREAS UNDER THE STRATUS WILL
SEE LITTLE CHANGE IN TEMPERATURES WITH SLIGHTLY WARMER READINGS
EARLY THIS MORNING AND SLIGHTLY COOLER READINGS FOR DAYTIME HIGHS.
WHILE AREAS UNDER CLEAR SKIES WILL HAVE AN EASIER TIME REBOUNDING
FROM OVERNIGHT LOWS. THIS IS REFLECTED IN THE HIGH TEMPERATURE
FORECAST FOR TODAY WITH 30S EXPECTED ACROSS THE CLEAR SOUTHWEST
AND TEENS/20S EXPECTED ACROSS THE NORTHERN JAMES VALLEY.
OVERALL A RATHER PLEASANT DAY IS EXPECTED AS WINDS WILL CONTINUE
TO DIMINISH AND SKIES SLOWLY CLEAR THROUGH THE DAY.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 234 AM CST MON DEC 8 2014
BROAD UPPER LEVEL RIDGING IS FORECAST BUILD INTO THE REGION
THROUGH THE END OF THE WEEK...THEN BEGIN TO BREAK DOWN OVER THE
WEEKEND.
FOR TUESDAY...A RIDGE-RUNNER SHORTWAVE IS FORECAST TO TRAVERSE
NORTH DAKOTA. EVEN THOUGH UPPER LEVEL SUPPORT SHOULD BE STRONG
ENOUGH TO GENERATE ELEVATED SNOW SHOWERS...THE MODEL SOUNDINGS
INDICATE THAT A DRY THERMODYNAMIC PROFILE UP TO 600MB WILL BE IN
PLACE. THEREFORE...VIRGA WILL LIKELY BE OBSERVED TUESDAY.
HOWEVER...WOULD NOT BE SURPRISED IF A FEW FLAKES REACHED THE
SURFACE SOUTHWEST OF THE MISSOURI RIVER TUESDAY. DUE TO THE STRONG
UPPER FORCING BUT DRY BOUNDARY LAYER CONDITIONS...HANDLED THIS
SCENARIO WITH SILENT POPS IN THE GRIDS FOR NOW.
THE UPPER RIDGE IS FORECAST TO SHARPEN OVER THE NORTHERN PLAINS
WEDNESDAY THROUGH FRIDAY...WITH FRIDAY FORECAST TO BE THE WARMEST
DAY OF THE EXTENDED. FRIDAY FORECAST HIGH TEMPERATURES RANGE FROM
THE UPPER 30S TO UPPER 40S.
THE UPPER RIDGE IS PROGGED TO BEGIN TO BREAK DOWN SATURDAY AS A
LONG WAVE TROUGH ENTERS THE ROCKIES. THE MAIN ENERGY FROM THE
TROUGH IS GENERALLY FORECAST TO MOVE EAST INTO NORTH DAKOTA
SATURDAY NIGHT INTO SUNDAY. WILL CONTINUE TO BROAD BRUSH A SLIGHT
CHANCE OF SNOW SATURDAY NIGHT/SUNDAY GIVEN THE MODEL TO MODEL AND
RUN TO RUN INCONSISTENCIES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 522 AM CST MON DEC 8 2014
WIDESPREAD MVFR AND OCCASIONAL IFR CONDITIONS ARE LIKELY ACROSS
ALL TAF SITES THROUGH THE EARLY MORNING HOURS. PERSISTENT STRATUS
AT KMOT/KBIS/KJMS HAS INCREASED WESTWARD AND NOW ENCOMPASS KISN
AND KDIK. LOW CIGS WILL CLEAR OUT OF KISN/KDIK LATER THIS MORNING
AND KMOT/KBIS/KJMS LATER THIS AFTERNOON.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AJ
SHORT TERM...AJ
LONG TERM...TM
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS PORTLAND OR
412 AM PST MON DEC 8 2014
.SYNOPSIS...A BUSY WEATHER PATTERN WILL PREVAIL THIS WEEK FOR
SOUTHWEST WASHINGTON AND NORTHWEST OREGON...WITH WET AND WINDY
WEATHER AT TIMES. BROAD LOW PRESSURE OVER THE GULF OF ALASKA AND A
STRONG PACIFIC JET STREAM WILL ROTATE A SERIES OF INCREASINGLY STRONG
FRONTAL SYSTEMS INTO THE PACIFIC NORTHWEST THROUGH MIDWEEK. THE MAIN
UPPER LOW WILL OPEN UP AND MOVE ACROSS THE PACIFIC NORTHWEST AS AN
OPEN TROUGH...WITH THE FOCUS OF HEAVIEST RAIN SHIFTING SOUTHWARD INTO
CALIFORNIA BY THE END OF THE WEEK. COOLER AND SHOWERY WEATHER IS
EXPECTED THURSDAY NIGHT AND FRIDAY...WITH A DRYING TREND POSSIBLE FOR
THE WEEKEND.
&&
.SHORT TERM...TODAY THROUGH THURSDAY...WATER VAPOR IMAGERY AND
SATELLITE-DERIVED WINDS SHOW A POWERFUL JET STREAM SETTING UP ACROSS
THE PACIFIC...WITH WINDS ALREADY 180 KT+ WITHIN THE JET STREAM NEAR
300 MB. THIS POWERFUL JET STREAM WILL GUIDE A SERIES OF STRONG
FRONTAL SYSTEMS TOWARD THE WEST COAST THIS WEEK...WITH THE NEXT
SYSTEM SLATED TO ARRIVE TONIGHT AND TUESDAY MORNING.
THIS MORNING THE MOST IMMEDIATE CONCERN IS AREAS OF DENSE FOG IN THE
WILLAMETTE VALLEY SOUTH OF SALEM...WITH VISIBILITY DOWN TO A FEW
HUNDRED FEET AT TIMES IN PORTIONS OF CORVALLIS AND EUGENE. AREA
WEBCAMS SUGGEST THE DENSE FOG IS FAIRLY WIDESPREAD AT THE MOMENT...
SO DECIDED TO ISSUE A DENSE FOG ADVISORY UNTIL 9 AM. THE FOG MAY LIFT
AT TIMES DUE TO HIGH CLOUDS STREAMING OVER THE AREA AHEAD OF OUR NEXT
FRONTAL SYSTEM.
BACK TO THE ACTIVE PACIFIC STORM TRACK...MODELS ARE VARYING ON THE
DETAILS BUT IT DOES APPEAR THAT WE WILL HAVE AT LEAST TWO DISTINCT
STRONG FRONTAL SYSTEMS MOVE ONSHORE THE NEXT 2 DAYS. THE FIRST SYSTEM
IS TAKING SHAPE NEAR 135W AND WILL APPROACH THE COAST THIS AFTERNOON
AND EVENING...WITH SOUTH WINDS INCREASING MAINLY ON THE COASTAL
WATERS AS WELL AS THE BEACHES AND HEADLANDS. A HIGH WIND WATCH IS OUT
FOR THE BEACHES AND HEADLANDS WITH A STORM WATCH OUT FOR THE COASTAL
WATERS...AS THE 00Z/06Z NAM AND GFS CONTINUE TO SUGGEST WINDS 60-70
KT+ DEVELOPING AS LOW AS 950 MB BY THIS EVENING. THIS SHOULD BE
ENOUGH TO PRODUCE GUSTS 60-70 MPH FOR THE BEACHES AND HEADLANDS...BUT
WITH GRADIENTS HIGHLY OFFSHORE IT MAY TAKE SOME TIME FOR THESE WINDS
TO MATERIALIZE ON LAND. THE FIRST STAGES OF THIS EVENT ARE STARTING
TO FALL WITHIN THE WINDOW OF HRRR GUIDANCE...AND HRRR 10M WINDS ARE
FAIRLY UNIMPRESSIVE AS THE FIRST FRONTAL SYSTEM APPROACHES EARLY THIS
EVENING...SO WE OPTED TO KEEP THE HIGH WIND WATCH A WATCH FOR THE
TIME BEING. CONFIDENCE IN STRONG COASTAL WIND INCREASES WITH THE
SECOND FRONTAL SYSTEM EXPECTED TO MOVE THROUGH TUESDAY WITH 70 KT
WINDS DOWN TO 950 MB AND GRADIENTS SOMEWHAT MORE SOUTHERLY. WOULD NOT
BE SURPRISED TO SEE SOME OF OUR WINDIER BEACHES/HEADLANDS SITES GUST
TO 75 MPH EARLY TUE...BUT GUSTS SHOULD REMAIN 55 MPH OR LESS FOR THE
COASTAL COMMUNITIES WITH THIS FRONT AS WELL.
THESE FRONTAL SYSTEMS WILL DUMP A SIGNIFICANT AMOUNT OF RAIN ON
VANCOUVER ISLAND AND THE OLYMPIC PENINSULA...WITH PERIODS OF HEAVY
RAIN POSSIBLE FOR THE WILLAPA HILLS THROUGH TUESDAY. HOWEVER IT DOES
NOT APPEAR LIKELY THAT IT WILL BE ENOUGH TO CAUSE WIDESPREAD FLOODING
OF COASTAL DRAINAGES. WILL NEED TO WATCH THE GRAYS...AS IT TENDS TO
BE FAST-RESPONDING...BUT AT THIS POINT IT DOES NOT APPEAR ENOUGH FOR
THE GRAYS RIVER TO FLOOD EITHER. WITH SEAS APPROACHING 20 FEET OR
HIGHER DEVELOPING NEAR THE MOUTH OF WILLAPA BAY...HEAVY RAIN IN THE
WILLAPA HILLS...AND TIDES RUNNING HIGH DUE TO THE RECENT FULL
MOON...THERE IS A POSSIBILITY OF TIDAL OVERFLOW IN LOW-LYING AREAS
SURROUNDING WILLAPA BAY SUCH AS RAYMOND.
A DECENT PERIOD OF RAIN WILL SPREAD ACROSS THE FORECAST AREA
TUESDAY...AND 06Z NAM BUFR SOUNDINGS SUGGEST SOME INSTABILITY
ASSOCIATED WITH THE FRONT THROUGHOUT OUR CWA. NAM LIFTED INDICES GET
AS LOW AS -2 TO -4 DEG C WITH 500-750 J/KG OF CAPE...ALONG WITH
SIGNIFICANT LIFT ASSOCIATED WITH THE FRONT. SUSPECT THIS IS ENOUGH TO
WARRANT AT LEAST A SLIGHT CHANCE OF THUNDER TUESDAY AFTERNOON AND
EVENING. WITH STRONG WINDS JUST ABOVE THE SURFACE...HEAVIER SHOWERS
AND THUNDERSTORMS MAY HAVE THE ABILITY TO MIX STRONG WINDS DOWN TO
THE SURFACE...EVEN INLAND.
DUE TO THE VERY FAST AND DYNAMIC PACIFIC JET STREAM...DETAILS BEYOND
TUESDAY RAPIDLY BECOME MORE UNCERTAIN. BROAD PARENT LOW PRESSURE OVER
THE GULF OF ALASKA WILL LIKELY DRIFT EAST TOWARD BRITISH
COLUMBIA...PUSHING THE BAROCLINIC ZONE AND STRONGEST PORTION OF THE
JET STREAM CLOSER TO U.S. WEST COAST. THESE FACTORS COMING TOGETHER
COULD BE A POWDER KEG FOR STRONG LOW PRESSURE TO DEVELOP JUST
OFFSHORE SOMETIME WED/EARLY THU...OR NOT. MODEL SOLUTIONS HAVE VARIED
WILDLY ON WHERE AND WHEN LOW PRESSURE SYSTEMS WILL DEVELOP ALONG THE
BAROCLINIC ZONE AND HOW THEY WILL TRACK. FOR EXAMPLE...THE 00Z GFS
AND GEM BOTH DEVELOPED A SUB-980 MB LOW OFF THE OREGON COAST LATE
WED...TRACKING IT UP THE COAST THROUGH ASTORIA FOR WHAT WOULD BE A
SIGNIFICANT WIDESPREAD SOUTH WIND EVENT FOR NORTHWEST OREGON AND
SOUTHWEST WASHINGTON. HOWEVER THE 06Z GFS AND 00Z ECMWF SHOW LITTLE
TO NO SIGN OF THIS. SUSPECT THERE WILL BE ANOTHER PERIOD OF STRONG
WINDS ALONG THE COAST AND PROBABLY THE COAST RANGE AS WELL
MIDWEEK...WITH GUSTY WINDS LIKELY FOR THE WILLAMETTE VALLEY AS WELL.
JUST HOW STRONG IS HIGHLY UNCERTAIN AND PROBABLY WILL CONTINUE TO BE
THROUGH AT LEAST TOMORROW MORNING. THERE IS BETTER CONFIDENCE THAT
THE MIDWEEK PERIOD WILL BE FAIRLY WET...BUT THE AMOUNT OF RAINFALL
WILL HIGHLY DEPEND ON THE TRACKS OF ANY LOWS DEVELOPING ALONG THE
FRONTAL ZONE AS IT DRIFTS ONSHORE WED/THU. OROGRAPHIC ENHANCEMENT
JUST TO THE SOUTHEAST OF DEVELOPING LOWS COULD PROVIDE A PERIOD OF
VERY HEAVY RAIN TO THE COAST RANGE. THERE SEEMS TO BE DECENT MODEL
CONSENSUS THAT THE ATMOSPHERIC RIVER AND ITS FOCUS OF HEAVIEST RAIN
SHIFT SOUTHWARD INTO CALIFORNIA BY THURSDAY AFTERNOON. RAIN WILL
TAPER TO SHOWERS AS THE PARENT UPPER LOW OPENS UP AND STARTS TO MOVE
THROUGH THE PAC NW BY THE END OF THE WEEK. TEMPERATURES WILL BE MILD
DUE TO THE SUBTROPICAL AIR MASS THROUGH MIDWEEK...WITH COOLER
TEMPERATURES POSSIBLY LOWERING THE SNOW LEVEL BACK TO THE CASCADE
PASSES BY THURSDAY NIGHT. WEAGLE
.LONG TERM...FRIDAY THROUGH SUNDAY...AFTER A STORMY WEEK IT APPEARS
DRIER WEATHER WILL DEVELOP FOR THE WEEKEND AS THERE IS GOOD MODEL
CONSENSUS ON AN UPPER LEVEL RIDGE BUILDING ACROSS THE PAC NW. FRIDAY
COULD STILL BE SEASONABLY COOL AND SHOWERY AS THE WEAKENING UPPER
TROUGH PROGRESSES THROUGH THE PAC NW...WITH SNOW LEVELS NEAR THE
CASCADE PASSES. IF UPPER RIDGING DEVELOPS OVER THE WEEKEND...THERE
WILL LIKELY BE SIGNIFICANT VALLEY INVERSIONS WITH FOG BECOMING MORE
PERSISTENT FOR THE INLAND VALLEYS THROUGH THE PERIOD. WEAGLE
&&
.AVIATION...FOG CONTINUES TO DEVELOP IN THE CENTRAL AND SOUTH
WILLAMETTE VALLEY AS HIGH CLOUDS ARE MOVING OUT. COULD SEE SOME
ADDITIONAL FOG FORMATION IN THE NORTH WILLAMETTE VALLEY BEFORE
SUNRISE AS HIGH CLOUDS CLEAR THAT AREA AS WELL. CONDITIONS WILL GO
OSCILLATE BETWEEN VFR AND LIFR FOR THE CENTRAL AND SOUTH VALLEY AS
BANDS OF HIGH CLOUDS CONTINUE TO MOVE OVER THE AREA. FOG SHOULD
CLEAR FOR GOOD BY LATE MONDAY MORNING.
AS THE NEXT FRONT APPROACHES...LIGHT RAIN SHOULD BEGIN FALLING AT
THE COASTAL TAF SITES THIS AFTERNOON...WITH CIGS LOWERING TO LOW
VFR OR HIGH MVFR. THE FRONT SHOULD HOLD TOGETHER ENOUGH TO BRING
OCCASIONAL LIGHT RAIN TO THE INLAND TAF SITES OVERNIGHT AND EARLY
TUES MORNING...BUT EXPECT CONDITIONS TO REMAIN VFR.
OFFSHORE WINDS GUSTING 25 TO 35 KT WILL CONTINUE TO IMPACT AREAS
AROUND THE WEST END OF THE COLUMBIA RIVER GORGE...INCLUDING
KTTD...THROUGH MON. SOUTHERLY WINDS WILL ALSO BEGIN TO PICK UP
ALONG THE COAST DURING THE DAY AHEAD OF THE NEXT APPROACHING
FRONT.
KPDX AND APPROACHES...MAINLY VFR CONDITIONS EXPECTED THROUGH 06Z
TUE WITH SMALL POSSIBILITY OF IFR FOG AND/OR STRATUS WEST OF KTTD AS
HIGH CLOUDS CLEAR OUT. OFFSHORE WINDS WILL CONTINUE TO GUST 25 TO
35 KT AROUND THE WEST END OF THE COLUMBIA RIVER GORGE THROUGH MON.
BOWEN/PYLE
&&
.MARINE...WINDS AND SEAS ARE INCREASING THIS EVENING AHEAD OF AN
OCCLUDED FRONT THAT IS APPROACHING THE WATERS. EXPECT THE
STRENGTHENING WINDS AND BUILDING SEAS THROUGH THE DAY TODAY WITH
SEAS APPROACHING 20 FT BY THIS EVENING.
THE FRONTAL BOUNDARY WILL LIE OVER THE REGION FOR MON NIGHT AND
TUE. A SERIES OF DISTURBANCES WILL MOVE ALONG THE FRONT...LIFTING
IT BACK AND FORTH TO THE N AND S. THIS WILL MAINTAIN GUSTY S
WINDS AND STEADILY INCREASING SEAS. THE NEXT LOW APPROACHES LATER
MON...AND WINDS WILL INCREASE TO STRONG SOUTHERLY GALES WITH
INCREASING POTENTIAL FOR STORM WINDS...PARTICULARLY WITH THE
POSSIBILITY OF A COASTAL JET MONDAY NIGHT AND INTO TUESDAY
MORNING. HAVE ISSUED A STORM WATCH FOR THIS POTENTIAL. SEAS LOOK
LIKE THEY`LL PEAK LATE MONDAY NIGHT/EARLY TUESDAY MORNING (BEFORE
SUNRISE) AROUND 25 FT.
ANOTHER SYSTEM IS ON TAP FOR TUE...WITH MORE STRONG SOUTHERLY
GALES AND SEAS BUILDING HIGHER STILL. THE STRONGEST SYSTEM
ARRIVES ON WED...WITH STORM FORCE WINDS LIKELY. THE SYSTEM HAS
POTENTIAL TO BE STRONGER THAN CURRENTLY MODELED. WOULD NOT BE
SURPRISED IF WE GET HURRICANE FORCE WIND GUSTS SOMEWHERE ON THE
OREGON WATERS LATER WED AFTERNOON...POTENTIALLY IN A COASTAL JET.
SEAS WILL BUILD FURTHER...PEAKING AROUND 30 FT WED. BOWEN
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...DENSE FOG ADVISORY UNTIL 9 AM PST THIS MORNING FOR SOUTH
WILLAMETTE VALLEY.
HIGH WIND WATCH FROM THIS EVENING THROUGH TUESDAY MORNING FOR
CENTRAL OREGON COAST-NORTH OREGON COAST.
WA...HIGH WIND WATCH FROM THIS EVENING THROUGH TUESDAY MORNING FOR
SOUTH WASHINGTON COAST.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 8 AM PST THIS MORNING FOR
COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.
STORM WATCH FROM THIS EVENING THROUGH TUESDAY MORNING FOR
COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.
GALE WARNING FROM 8 AM THIS MORNING TO 6 PM PST THIS EVENING
FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT
60 NM.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 8 AM PST THIS
MORNING FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE
OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 4 AM
PST TUESDAY.
&&
$$
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 DENVER/BOULDER CO
1013 AM MST MON DEC 8 2014
.UPDATE...
ISSUED AT 1011 AM MST MON DEC 8 2014
FORECAST IS ON TRACK TODAY WITH HIGH CLOUDS AND SLIGHTLY COOLER
TEMPERATURES. 12Z DENVER SOUNDING SHOWS A FAIRLY SHALLOW INVERSION
SO WE SHOULD STILL BE ABLE TO REACH THE MID 50S ON MOST OF THE
PLAINS DESPITE THE CLOUDS. DID LOWER A COUPLE DEGREES IN VALLEY
LOCATIONS AND ADDED A BIT MORE SKY COVER PER LATEST SYNTHETIC
IMAGERY AND HRRR CLOUD COVER PRODUCT...BUT STILL SOME THIN SPOTS
IN HIGH LEVEL CLOUD DECK. THOSE WILL BREAK BY VERY LATE THIS
AFTERNOON/EARLY EVENING.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 359 AM MST MON DEC 8 2014
QUIET WEATHER WILL PREVAIL THROUGH TONIGHT AS AN UPPER LEVEL RIDGE
OVER THE GREAT BASIN SHIFTS EAST. THERE WILL BE AN INCREASE IN
MOISTURE AT UPPER LEVELS...SO EXPECT SCATTERED TO BROKEN HIGH CLOUD
COVER TO PREVAIL TODAY. A SURFACE HIGH WILL BE OVER THE STATE
TODAY...RESULTING IN A WEAK PRESSURE GRADIENT AND LIGHT WINDS. THE
INCREASE IN CLOUD COVER AND LACK OF MIXING DUE TO THE LIGHT WINDS
WILL RESULT IN SLIGHTLY COOLER TEMPERATURES FOR TODAY.
HOWEVER...HIGHS WILL STILL BE ABOUT 10 DEGREES ABOVE NORMAL.
SOME HIGHS CLOUDS MAY LINGER ACROSS FAR NORTHERN COLORADO TONIGHT...
OTHERWISE EXPECT MOSTLY CLEAR SKIES. THE LIGHT WINDS AND CLEAR SKIES
WILL ALLOW LOW LYING AREAS TO BE COOL TONIGHT...BUT MILD FOR
DECEMBER.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 359 AM MST MON DEC 8 2014
ON TUESDAY MODELS SHOW A WEAK NORTHERN STREAM SHORTWAVE TROUGH
PASSING TO THE NORTH OF COLORADO. STRONG PRES FALLS INDUCED BY THE
PASSING WAVE MAY ENHANCE SLY LOW-LEVEL WINDS ON THE PLAINS OF NERN
COLORADO DURING THE DAY. OTHERWISE LOOK FOR ANOTHER DAY OF WARMER
THAN AVERAGE TEMPERATURES AND PERIODS OF HIGH CLOUDINESS.
BY WEDNESDAY A STRONG UPPER LEVEL RIDGE GRADUALLY BUILDS OVER THE
REGION. LOOK FOR A STEADY WARMUP THROUGH FRIDAY. ATMOSPHERE ALSO
REMAINS QUITE DRY WITH AFTERNOON RH VALUES ALONG THE FRONT RANGE
LOWERING INTO THE TEENS ON THURSDAY AND FRIDAY WITH DOWNSLOPING WEST-
SWLY BOUNDARY LAYER FLOW. WARMEST AIR ALOFT IS PROGGED TO BE OVER
THE CWA ON FRIDAY COINCIDENT WITH THE 700-500MB RIDGE AXIS. THE GFS
700 MB TEMP OVER THE I-25 URBAN CORRIDOR AT 18Z FRI IS FCST TO BE
AROUND 7C...WHILE THE EC GIVES A 700MB CLOSER TO 9C. BROUGHT DOWN
DRY ADIABATICALLY...WHICH NORMALLY WOULD NOT BE A PROBLEM ON A SUNNY
DAY...DENVER COULD PRESUMABLY HIT A HIGH OF 74 F! KEEP IN MIND
DENVER`S CURRENT RECORD FOR THE 12TH IS 69 F. A STEADY INFLUX CIRRUS
THROUGH THE DAY WILL PROBABLY PREVENT MOST AREAS FROM REACHING THE
70 DEG MARK. THEREFORE WILL HOLD ONTO THE MID AND UPPER 60 F HIGHS
FOR THE PLAINS ON FRIDAY. HIGH COUNTRY READINGS WEDNESDAY-FRIDAY
ALSO LOOK QUITE WARM WITH ABOVE AVERAGE TEMPS THE NORM. LASTLY...
PRECIP CHANCES THROUGH FRIDAY ARE ESSENTIALLY NIL.
ON SATURDAY...THE UPPER RIDGE MOVES OUT MAKING WAY FOR A HIGH
AMPLITUDE UPPER TROUGH TO MOVE IN FROM THE GREAT BASIN. THE GFS...
EC...GEM AND FIM MODELS ALL CONTINUE TO SHOW THIS TROUGH MOVING OVER
COLORADO DURING THE WEEKEND. HOWEVER IN THE PAST 24 HOURS THESE SAME
MODELS HAVE TRENDED THE BUSINESS END OF THIS TROUGH FARTHER SOUTH.
A CLOSED 500 LOW OVER THE 4-CORNERS SAT NIGHT QUICKLY TRACKS SEWRD
TO OVER SERN NEW MEX BY MID-DAY SUNDAY ACCORDING TO THE LATEST MODEL
RUN. JUST 24-36 HRS AGO HALF OF THESE MODELS SHOWED THE UPPER LOW
MUCH CLOSER OVER SERN COLORADO. WITH PASSAGE OF THE UPPER TROUGH SAT
NIGHT/SUN MORNING THE HIGH COUNTRY SHOULD STILL PERIODS OF LIGHT
SNOWFALL BUT WITH ONLY LIGHT ACCUMULATION POSSIBLE. WHEREAS THE
PLAINS WILL ONLY HAVE A SLIGHT CHANCE OF RAIN OR A RAIN/SNOW MIX
MAINLY ON SUNDAY AS IT LOOKS NOW. EXPECT COOLER 50S ON THE PLAINS
SATURDAY DUE MAINLY TO GREATER CLOUD COVER AND ONLY UPPER 30S/LOWER
40S ON SUNDAY FOLLOWING PASSAGE OF A COLD FRONT SATURDAY NIGHT.
HIGHS IN THE 20S AND 30S WILL BE COMMON IN THE HIGH COUNTRY BOTH
DAYS. BY LATE ON SUNDAY...ITS POSSIBLE NORTHERN PORTIONS OF THE FCST
AREA WILL BEGIN TO CLEAR OUT WITH DRIER AIR SPREADING DOWN FROM
WYOMING ON GUSTY NLY WINDS. RIGHT NOW...THIS STORM SYSTEM DOES NOT
LOOK LIKE THE BIG SNOW MAKER IT ONCE DID. OH WELL...MODELS SHOW
ANOTHER MOISTURE PACKED PACIFIC STORM SYSTEM WAITING OFF THE WEST
COAST NEXT WEEK.
&&
.AVIATION...(FOR THE TAFS THROUGH 18Z TUESDAY MORNING)
ISSUED AT 1011 AM MST MON DEC 8 2014
LIGHT AND VARIABLE WINDS AROUND 6 KNOTS WILL TRANSITION TO LIGHT
DIURNAL EAST/NORTHEASTERLIES THIS AFTERNOON. BACK TO NORMAL
DRAINAGE WINDS TONIGHT BUT PERHAPS A BIT LATER TOWARD 02Z-04Z
GIVEN LATEST SHORT RANGE MODEL TRENDS. VFR CONDITIONS WILL
PERSIST WITH ONLY BKN HIGH CLOUDS ABOVE 14000 AGL.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BARJENBRUCH
SHORT TERM...MEIER
LONG TERM...BAKER
AVIATION...BARJENBRUCH
AREA FORECAST DISCUSSION
NWS NEW YORK NY
107 PM EST MON DEC 8 2014
.SYNOPSIS...
A NOR`EASTER WILL TAKE SHAPE OFF THE CAROLINA COAST TODAY AND
TRACK UP THE MID ATLANTIC COAST TOMORROW AND INTO SOUTHERN NEW
ENGLAND TUESDAY NIGHT. THE LOW WILL THEN BECOMING NEARLY
STATIONARY ACROSS THE NORTHEAST AND GRADUALLY WEAKEN THROUGH THE
END OF THE WEEK. HIGH PRESSURE THEN BUILDS IN FROM THE WEST ON
FRIDAY AND REMAINS IN CONTROL THROUGH THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LIGHT SNOW OVER SUFFOLK COUNTY SHOULD TRANSFER OVER TO LIGHT RAIN
WITH PERHAPS SOME POCKETS OF FREEZING DRIZZLE. DO NOT EXPECT THIS
TO MAKE IT MUCH PAST NASSAU COUNTY AS LOW LEVELS ARE STILL DRY
OVER NYC AND POINT WEST.
CLASSIC VEERING IN THE SFC TO 5000` SEEN IN VAD WIND PROFILE - SO
THINK WE`LL WARM TO SUPER COOLED LIQUID.
REGARDLESS ALL PCPN IS VERY LIGHT.
RAP SEEMS TO HAVE A GOOD HANDLE ON THIS PCPN AND HRRR IS CATCHING
ON.
TEMPS BASICALLY STEADY REST OF THE AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
HIGH CONFIDENCE IN A STRONG NOR`EASTER AS MODELS ARE IN STRONG AGREEMENT
OF RAPIDLY DEEPENING LOW PRESSURE ON TUESDAY ALONG THE DELMARVA
COAST THAT TRACKS INTO SOUTHERN NEW ENGLAND TUE NIGHT. FOR OUR AREA
THIS IS LOOKING TO BE PRIMARILY A HEAVY RAIN MAKER...ACCOMPANIED
BY COASTAL FLOODING AND STRONG WINDS. WHILE THERE IS STRONG HIGH
PRESSURE IN PLACE INITIALLY...IT RETREATS AND WEAKENS ACROSS THE
CANADIAN MARITIMES TONIGHT INTO TUE. THE LOW TRACK IS ALSO
FORECAST TO BE WELL WEST OF THE BENCHMARK OF 40N...70W THAT
TYPICALLY IS ASSOCIATED WITH HEAVY SNOW MAKERS FOR THIS AREA.
THE INGREDIENTS ARE THERE WITH STRONG FRONTAL BANDING TO THE NORTH
AND WEST OF THE LOW TRACK FOR MODERATE TO HEAVY RAINFALL FOR MOST
OF THE DAY TUE...TAPERING OFF IN THE LATE EVENING. RESIDUAL COLD
AIR IN THE INTERIOR VALLEYS OF ORANGE COUNTY MAY BE ENOUGH FOR A
LIGHT ACCUMULATION OF ICE. ELSEWHERE...PATCHY FREEZING RAIN/DRIZZLE
IS POSSIBLE ACROSS THE INTERIOR FOR A BRIEF OF TIME...BUT THERE
IS MORE UNCERTAINTY. ALL LOCATIONS WILL BE OVER TO RAIN BY MID
MORNING.
THE PRESSURE GRADIENT AHEAD OF THE LOW BECOMES VERY STRONG TUE
MORNING/AFT WITH A 60 TO 70 KT LOW-LEVEL JET NEAR THE BOUNDARY
LAYER. THIS COMBINED WITH THE HEAVY RAINFALL...RAISES THE
POTENTIAL FOR DOWNWARD TRANSFER MOMENTUM AND HIGH WINDS REACHING
THE SFC. A HIGH WIND WATCH HAS BEEN ISSUED FOR LI...NYC
METRO...SOUTHERN WESTCHESTER...AND COASTAL CT. THERE IS THE
POTENTIAL FOR GUSTS TO REACH 60 MPH IN THESE AREAS WITH SOME
PROPERTY DAMAGE AND POWER OUTAGES.
EXPECT RAINFALL AMOUNTS TO AVERAGE 2 TO 3 INCHES WITH LOCALIZED
HIGHER AMOUNTS. THESE AMOUNTS WERE ALSO PRECEDED BY 1 TO 2 INCHES
A COUPLE OF DAYS AGO. A FLOOD WATCH HAS BEEN ISSUED FOR THE ENTIRE
FORECAST AREA...PRIMARILY FOR URBAN/POOR DRAINAGE FLOODING.
HOWEVER...FFG GUIDANCE IS LOW ACROSS NE NJ AND SOME SMALL RIVERS
AND STREAMS COULD COME OUT OF THEIR BANKS.
AS FOR TEMPS...READINGS WILL GRADUALLY RISE TONIGHT WITH THE
POTENTIAL FOR THE COASTAL FRONT TO PUSH ONSHORE LI WITH HIGHS ON
TUE INTO THE LOWER 50S ACROSS EASTERN LI/SE CT. HIGHS INLAND WILL
BE AROUND 40.
RAIN IS EXPECTED TO GRADUALLY CHANGE OVER TO SNOW TUE NIGHT
ACROSS PORTIONS OF THE LOWER HUDSON VALLEY...INTERIOR SW CT AND NE
NJ. SINCE THERE IS STILL A LOT OF UNCERTAINTY WITH THIS
SYSTEM...THE TIMING OF CHANGEOVER AND SNOW/SLEET AMOUNTS REMAIN
LOW CONFIDENCE. ADVSY LEVEL SNOW IS POSSIBLE IN ORANGE COUNTY AND
POSSIBLY WESTERN PASSAIC. WARNING LEVEL SNOW AMOUNTS DO NOT APPEAR
LIKELY AT THIS TIME ALTHOUGH SOME LOCATIONS ACROSS NW ORANGE
COUNTY MAY COME CLOSE. RAIN EXPECTED FROM SE CT AND LONG
ISLAND...POSSIBLY ALL RAIN IN NYC AS WELL WITH A MIX IN BETWEEN.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS THE UPPER LOW MOVES OVERHEAD THE STEADY PCPN WILL SHIFT INLAND
AND LIGHTEN AT THE COAST. IT BECOMES MORE SHOWERY IN NATURE WED
THROUGH THU NIGHT WITH COVERAGE GRADUALLY DECREASING. COLDER AIR
WRAPPING AROUND THE STORM WILL CAUSE PTYPE TRANSITION TO MOSTLY
SNOW ACROSS MUCH OF THE AREA.
UNSETTLED WEATHER COULD REMAIN INTO THE WEEKEND IF THE ECMWF SOLN IS
CORRECT. OTHERWISE...HIGH PRES BUILDS FROM THE WEST WILL DRY AND
SEASONABLE CONDS.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
HI PRES REMAINS OVER THE CANADIAN MARITIMES THIS AFTERNOON. LOW PRES
DEVELOPS SE OF HATTERAS TNGT...AND TRACKS NWD TO A POINT OFF THE
NJ COAST BY TUE AFTN.
STRATUS SHIELD ADVANCING NWWD FROM THE OCEAN. SOME SN/PL OBSERVED
ALONG SOUTH COAST OF LONG ISLAND AND COULD AFFECT KISP EARLY THIS
AFTERNOON. CONFIDENCE IS LOW. CIGS AROUND 15-20K FT EVERYWHERE
REMAINDER OF THIS AFTERNOON. SOME LGT DZ POSSIBLE AT TIMES THIS
EVENING. IN THE INTERIOR...FZDZ DEVELOPS.
STEADY PCPN DEVELOPS TNGT...WITH -FZRA POSSIBLE KEWR KJFK AND
KSWF. THE RAIN GETS HEAVIER TUE MRNG FROM S TO N.
NE WINDS THRU THE TAF PERIOD. SPEEDS INCREASE DRAMATICALLY AFT 6Z
TNGT...WITH THE POTENTIAL FOR PEAK GUSTS FROM THE CITY EWD UP TO
50 KT AFT 12Z TUE.
...NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: IFR IN CIGS MAY ARRIVE EARLIER THAN
FORECAST AFTER 00Z. LIGHT FROZEN MIX POSSIBLE AT PRECIP ONSET.
KLGA FCSTER COMMENTS: IFR IN CIGS MAY ARRIVE EARLIER THAN
FORECAST AFTER 00Z. LIGHT FROZEN MIX POSSIBLE AT PRECIP ONSET AND
WILL AMEND IF NEEDED.
KEWR FCSTER COMMENTS: ADJUSTMENTS OF AN HOUR OR TWO MAY BE NEEDED
FOR THE ONSET OF IFR CIGS. LIGHT FROZEN MIX POSSIBLE AT PRECIP ONSET.
KTEB FCSTER COMMENTS: ADJUSTMENTS OF AN HOUR OR TWO MAY BE NEEDED
FOR THE ONSET OF IFR CIGS.
KHPN FCSTER COMMENTS: ADJUSTMENTS OF AN HOUR OR TWO MAY BE NEEDED
FOR THE ONSET OF IFR CIGS.
KISP FCSTER COMMENTS: ADJUSTMENTS OF AN HOUR OR TWO MAY BE NEEDED
FOR THE ONSET OF IFR CIGS.
.OUTLOOK FOR 18Z TUE THROUGH SAT...
.18Z TUE...IFR. RAIN TAPERING IN THE AFTERNOON. NE WINDS 20-30KT. GUSTS UP
TO 50KT POSSIBLE.
.TUE NIGHT-WED...IFR LIKELY. SNOW/RAIN SHOWERS AT KSWF. RAIN SHOWERS
ELSEWHERE. NW WINDS 15-20G25-30KT.
.THU...MVFR OR LOWER AT TIMES. RAIN AND/OR SNOW SHOWERS POSSIBLE.
.FRI AND SAT...VFR.
&&
.MARINE...
OCEAN SEAS WERE RAISED EARLIER ABOUT 2 FT AS WW3 GUIDANCE IS LOW.
SEAS ON THE SOUND WERE ALSO RAISED TO 3-4 FT.
WINDS LESSEN SLIGHTLY THIS AFTERNOON.
TONIGHT...WINDS INCREASE AND CONTINUE TO DO SUCH THROUGH TUESDAY WITH
THE APPROACH OF THE NOR`EASTER. A STRONG LLJ STILL FORECAST TO
PASS THROUGH DURING THIS PERIOD. GALE AND STORM WATCH IN EFFECT.
DUE TO THE CONTINUED UNCERTAINTY IN STRENGTH...TIMING AND TRACK OF
THE LOW AFFECTING THE WATERS DURING THE MIDDLE OF THE WEEK...THE
TYPE AND DURATION OF HAZARDS ON THE WATERS REMAINS QUESTIONABLE.
MODEL GUIDANCE IS IN GOOD AGREEMENT THAT THE LOW TRACKS OVER EASTERN
WATERS TUE NIGHT...BUT START TO DEVIATE WITH HOW LONG IT MEANDERS
ABOUT THIS LOCATION UNTIL LIFTING NORTH. IF THE LOW REMAINS DIRECTLY
OVER THE AREA...GALE FORCE WINDS WILL LIKELY SUBSIDE TUESDAY NIGHT
WITH ONLY SMALL CRAFT CONDITIONS BEING MET (POSSIBLY ONLY ON THE
OCEAN PORTIONS OF THE WATERS) THROUGH THURSDAY NIGHT AND POSSIBLY
INTO FRIDAY MORNING. THERE COULD BE OCCASIONAL GALE GUSTS WEDNESDAY
NIGHT INTO THURSDAY MORNING.
&&
.HYDROLOGY...
EXPECT RAINFALL AMOUNTS TO AVERAGE 2 TO 3 INCHES WITH LOCALIZED
HIGHER AMOUNTS. THESE AMOUNTS WERE ALSO PRECEDED BY 1 TO 2 INCHES
A COUPLE OF DAYS AGO. A FLOOD WATCH HAS BEEN ISSUED FOR THE ENTIRE
FORECAST AREA...PRIMARILY FOR URBAN/POOR DRAINAGE FLOODING.
HOWEVER...FFG GUIDANCE IS LOW ACROSS NE NJ AND SOME SMALL RIVERS
AND STREAMS COULD COME OUT OF THEIR BANKS.
&&
.TIDES/COASTAL FLOODING...
A PROLONGED PERIOD OF MODERATE TO HIGH EASTERLY SWELLS AND HIGH
STORM TIDES THROUGH MID WEEK WILL CAUSE SIGNIFICANT BEACH EROSION
AND LIKELY WASH-OVER ISSUES AT THE BARRIER BEACHES.
WIDESPREAD MINOR COASTAL FLOODING IS OCCURRED THIS MORNING INTO
EARLY AFTERNOON DUE TO THE PERSISTENT NE FLOW.
ANOTHER ROUND OF WIDESPREAD MINOR TO LOCALLY MODERATE COASTAL
FLOODING WILL OCCUR TUESDAY MORNING/AFTN HIGH TIDE CYCLE. THE
FLOODING WITH THIS TIDAL CYCLE COULD WELL BE EXACERBATED BY HEAVY
RAINFALL.
THIS FORECAST WILL HAVE TO BE FINE TUNED AS THE TIMING...TRACK AND
INTENSITY OF THE LOW PRESSURE SYSTEM BECOME FURTHER REFINED.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...FLOOD WATCH FROM TUESDAY MORNING THROUGH LATE TUESDAY NIGHT
FOR CTZ005>012.
COASTAL FLOOD ADVISORY FROM 10 AM TO 3 PM EST TUESDAY FOR
CTZ011-012.
HIGH WIND WATCH FROM TUESDAY MORNING THROUGH TUESDAY AFTERNOON
FOR CTZ009>012.
COASTAL FLOOD WATCH FROM TUESDAY MORNING THROUGH TUESDAY
AFTERNOON FOR CTZ009-010.
COASTAL FLOOD ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
CTZ009-010.
NY...FLOOD WATCH FROM TUESDAY MORNING THROUGH LATE TUESDAY NIGHT
FOR NYZ067>075-078>081-176>179.
COASTAL FLOOD ADVISORY FROM 10 AM TO 3 PM EST TUESDAY FOR
NYZ079-081.
HIGH WIND WATCH FROM TUESDAY MORNING THROUGH TUESDAY AFTERNOON
FOR NYZ071>075-078>081-176>179.
COASTAL FLOOD ADVISORY FROM 7 AM TO 11 AM EST TUESDAY FOR
NYZ072-074-075-080-178-179.
COASTAL FLOOD WATCH FROM TUESDAY MORNING THROUGH TUESDAY
AFTERNOON FOR NYZ071-073-078-176-177.
COASTAL FLOOD ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
NYZ071-073-078-176-177.
WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 9 AM EST
TUESDAY FOR NYZ067.
NJ...FLOOD WATCH FROM TUESDAY MORNING THROUGH LATE TUESDAY NIGHT
FOR NJZ002-004-006-103>108.
COASTAL FLOOD ADVISORY FROM 7 AM TO 11 AM EST TUESDAY FOR
NJZ006-106-108.
MARINE...GALE WATCH FROM LATE TONIGHT THROUGH TUESDAY AFTERNOON FOR
ANZ338-345.
STORM WATCH FROM LATE TONIGHT THROUGH TUESDAY AFTERNOON FOR
ANZ330-335-340-350-353-355.
SMALL CRAFT ADVISORY UNTIL 1 AM EST TUESDAY FOR ANZ350-353-355.
&&
$$
SYNOPSIS...BC/DW
NEAR TERM...TONGUE
SHORT TERM...TONGUE
LONG TERM...24
AVIATION...IRD
MARINE...BC/TONGUE
HYDROLOGY...DW
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS MIAMI FL
1256 PM EST MON DEC 8 2014
.AVIATION...
VFR CONDITIONS WILL PERSIST THROUGH THE BULK OF THE PERIOD WITH
LIGHT NW LOW-LEVEL FLOW CONTINUING. ALTHOUGH CONFIDENCE IS NOT AS
HIGH AS THIS MORNING...PATCHY FOG/LOW CIGS WILL BE POSSIBLE
TONIGHT INTO TUESDAY MORNING ACROSS PORTIONS OF THE AREA ONCE
AGAIN (MODEL PROBS OF REDUCED VSBYS REMAIN LOW). /85
&&
.PREV DISCUSSION... /ISSUED 1114 AM EST MON DEC 8 2014/
UPDATE...
AS NOTED IN THE MORNING DISCUSSION...THE COMBINATION OF STRONG
HIGH PRESSURE ALONG THE CANADIAN ATLANTIC COAST AND LOW PRESSURE
IN THE VICINITY OF BERMUDA HAS CREATED A STRONG AND PERSISTENT
PRESSURE GRADIENT AND WELL ESTABLISHED NORTHEAST FETCH ACROSS THE
WESTERN ATLANTIC EAST OF THE CAROLINAS WITH RECENT SCATTEROMETER
SATELLITE DERIVED WINDS INDICATING STRONG NORTHEASTERLY WINDS.
THESE CONDITIONS ARE FORECAST TO PRODUCE LONG-PERIOD
NORHTHEASTERLY SWELL THAT WILL CONTINUE TO ENTER THE ATLANTIC
WATERS EAST OF PALM BEACH COUNTY TODAY. THE LONG-PERIOD SWELL
WILL CONTINUE TO ENTER THE REGIONAL ATLANTIC WATERS TONIGHT INTO
TUESDAY AND FORECAST TO CONTINUE THROUGH AT LEAST WEDNESDAY. THIS
PROMPTED THE ISSUANCE OF A HIGH RISK OF RIP CURRENTS FOR THE
ATLANTIC COAST BEACHES THROUGH WEDNESDAY EVENING. IN ADDITION...A
HIGH SURF ADVISORY WILL LIKELY BE NECESSARY...MAINLY FOR THE
BEACHES EAST OF PALM BEACH COUNTY WITH CURRENT SURF HEIGHTS
FORECAST TO BE NEAR 10 FEET BY EARLY TUESDAY MORNING. A HIGH SURF
ADVISORY WILL LIKELY BE ISSUED THIS AFTERNOON FOR THE PALM BEACH
COUNTY BEACHES TONIGHT THROUGH WEDNESDAY EVENING.
60
PREV DISCUSSION... /ISSUED 627 AM EST MON DEC 8 2014/
AVIATION...
RECENTLY ANIMATED IR2 IMAGERY SHOWED A LARGE SHIELD OF LOW STRATUS
ACROSS MUCH OF SOUTH FLORIDA ACROSS THE INTERIOR AND GULF REGIONS.
AT THIS TIME...IT APPEARS THE MAIN ISSUE FROM THIS STRATUS DECK
WILL BE MVFR/IFR CIGS, ESPECIALLY OVER APF AND PBI. THIS DECK
SHOULD BEGIN TO LIFT AND BURN OFF THROUGH THE MID-MORNING PERIOD
WITH A RETURN OF VFR CONDITIONS. WINDS WILL REMAIN LIGHT OUT OF
THE NNW TODAY THEN NE AT SITE APF LATER TONIGHT INTO TUESDAY
MORNING. /85
PREV DISCUSSION... /ISSUED 406 AM EST MON DEC 8 2014/
SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH TONIGHT...USHERING IN AN EXTENDED
PERIOD OF NORTHWEST WINDS AND BELOW NORMAL TEMPERATURES. HIGH
PRESSURE WILL DOMINATE.
SHORT TERM /TODAY THROUGH WEDNESDAY/ ...
BEHIND YESTERDAYS COLD FRONT...TEMPS EARLY THIS MORNING ARE QUITE
A BIT COOLER THAN PREV FEW MORNINGS...WITH LOW 60S ALONG THE
COASTS AND 50S ELSEWHERE. LOW STRATUS/SOME VSBY RESTRICTIONS IS
PUSHING SOUTHWARD INTO GLADES AND HENDRY COUNTIES. HOW FAR SOUTH
THIS CLOUD LAYER ADVANCES IS UNCERTAIN...BUT IT APPEARS THAT AT
LEAST NORTH OF A NAPLES TO BOCA RATON LINE...MOSTLY CLOUDY
CONDITIONS WILL PREVAIL INTO LATE MORNING. NW WINDS WILL TURN NE
THIS AFTERNOON...AND TEMPERATURES SHOULD RISE TO NEAR
NORMAL...MID/UPR 70S. NE FLOW WILL BRING SOME LOW-LEVEL MOISTURE
DOWN THE E FL COASTLINE...AND THIS COULD BE ENOUGH TO BRING INLAND
A FEW SHOWERS INTO PALM BEACH COUNTY. THESE MAY CONTINUE INTO
EARLY TUESDAY...BEFORE A COLD FRONT BRINGS MUCH DRIER AIR INTO THE
REGION. MINIMA TONIGHT WILL ALSO BE NEAR AVERAGE FOR EARLY
DECEMBER...MAINLY IN THE MID/UPR 50S...WITH SOME LOW 60S ACROSS
THE EASTERN METROPOLITAN AREAS.
A POTENT SHORTWAVE TROUGH WILL DIVE THROUGH THE GREAT LAKES TODAY
AND INTO THE CENTRAL APPALACHIANS TONIGHT. BEHIND THE
TROUGH...CANADIAN HIGH PRESSURE WILL EXPAND THROUGH THE PLAINS AND
EVENTUALLY THE MISSISSIPPI RIVER VALLEY. THE TROUGHS ATTENDANT
SURFACE CDFNT WILL MOVE THROUGH THE OHIO VALLEY TODAY...WHILE
SURFACE LOPRES DEVELOPS OFF CAROLINAS. THE LOW WILL ACCELERATE THE
ARRIVAL OF THE FRONT INTO SOUTH FLORIDA AND ALSO INCREASE THE
COLD-AIR ADVECTION ASSOCIATED WITH IT. SIGNIFICANT COOLING WILL
OCCUR BY TUESDAY NIGHT AS THE UPPER TROUGH AXIS QUIETLY PASSES
BY. MINIMAS SHOULD REACH 40S OVER THE INTERIOR...WITH LOW 50S ALL
THE WAY TO THE EAST COAST. WIND CHILL VALUES WILL BE A FEW DEGREES
LOWER THAN THE TEMPERATURE OVERNIGHT. WEDNESDAY...CANADIAN RIDGE
BECOMES MORE ENTRENCHED OVER SOUTH FLORIDA...AND MAXIMA WILL HOLD
IN THE 60S.
SIGNIFICANT NE SWELL BEING TO ARRIVE IN SOUTH FLORIDA WATERS
TODAY /SEE DETAILS IN THE MARINE DISCUSSION BELOW/. THIS WILL LEAD
TO SIGNIFICANT RIP CURRENTS ALONG ATLANTIC BEACHES THROUGH AT
LEAST MID-WEEK. IN ADDITION...HIGH SURF MAY WARRANT AN ADVISORY
TUESDAY OR WEDNESDAY...AND BEACH EROSION/MINOR COASTAL
FLOODING...ARE ALSO POTENTIAL HAZARDOUS.
LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/ ...
AFOREMENTIONED SHORTWAVE TROUGH WILL DEEPEN FURTHER AND EVOLVED
INTO CLOSED H5 LOPRES OVER NE CONUS. THE FEATURE WILL THEN
STALL...AT LEAST INTO THE WEEKEND. MEANWHILE...EXPANSIVE SFC
RIDGE WILL REMAIN CENTERED NORTHWEST OF THE STATE. FOR SOUTH
FLORIDA...THIS MEANS EXPECT AN EXTENDED PERIOD OF NORTHWEST WINDS
WITH A COOL CANADIAN AIRMASS CONTINUING TO FILTER IN MUCH OF THE
WEEK. SKIES WILL BE MAINLY CLEAR. OVERNIGHT LOWS SHOULD MAINLY BE
IN 40S INTERIOR/50S METROPOLTIAN AREAS...WITH DAYTIME HIGHS IN THE
UPPER 60S TO LOW 70S. ALTHOUGH LONG-RANGE MODELS GENERALLY AGREE
ON THIS PATTERN CONTINUING INTO THE WEEKEND...LATEST ECMWF RUN
BRINGS ADDITIONAL REINFORCEMENTS OF COOL AIR DOWN THE PENINSULA.
IF THIS PANS OUT...FORECAST TEMPERATURES MAY BE SEVERAL DEGREES TO
WARM FOR THE END OF THE WEEK.
AVIATION...
STILL MONITORING A SHIELD OF LOW CIGS PUSHING SOUTH ACROSS THE
CENTRAL FLORIDA PENINSULA PER THE LATEST MICRON SATELLITE IMAGERY.
THE TIMING AND EXACT EXTENT OF THE SOUTHERN PROPAGATION OF THIS
SHIELD REMAINS IN QUESTION. LATEST HRRR AND SREF CIG HEIGHT
PROBABILITIES KEEP THE MAJORITY OF THE LOW CIGS ACROSS THE
INTERIOR WITH THE PERIPHERY OF WHICH EXTENDING TO BOTH THE
ATLANTIC AND GULF COASTS...POSSIBLY AFFECTING THE TAF SITES. KEPT
ANY MVFR/IFR CIGS OUT OF TAFS FOR NOW DUE TO UNCERTAINTY BUT WILL
CONTINUE TO MONITOR AND AMEND AS NECESSARY. OTHERWISE...LIGHT
NORTH-NORTHWESTERLY FLOW WILL PREVAIL AT THE EAST COAST SITES
THROUGH THE MORNING WITH NORTHEASTERLY FLOW AT KAPF.
MARINE...
IMPRESSIVE FETCH GENERATED BY LOPRES WEST OF BERMUDA IS BRINGING
NELY SWELL DOWN THE FLORIDA PENINSULA EARLY THIS MORNING. WAVE
HEIGHTS ARE ALREADY EXCEEDING 10 FT OFFSHORE THE MELBOURNE/CAPE
CANAVERAL AREA...AND WILL LIKELY REACH WATERS OFF PALM BEACH
COUNT THIS AFTERNOON...THEN THE REMAINDER OF ATLANTIC WATERS
TONIGHT. SMALL CRAFT ADVISORIES HAVE BEEN ISSUED ACCORDINGLY. THE
5 TO 8 FOOT SWELL WILL PERSIST TUESDAY INTO WEDNESDAY...LEADING TO
A CONTINUATION OF HAZARDOUS MARINE CONDITIONS. WAVES IN THE GULF
STREAM MAY EXCEED 13 FEET DURING THIS TIME.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 61 73 50 67 / 10 10 0 0
FORT LAUDERDALE 62 75 54 69 / 0 10 0 0
MIAMI 62 75 53 70 / 0 0 0 0
NAPLES 58 71 50 67 / 0 0 0 0
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK THROUGH WEDNESDAY EVENING FOR FLZ168-172-
173.
AM...SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 7 PM EST
WEDNESDAY FOR AMZ651-671.
SMALL CRAFT ADVISORY UNTIL 7 PM EST WEDNESDAY FOR AMZ650-670.
HIGH RIP CURRENT RISK THROUGH WEDNESDAY EVENING FOR AMZ630.
GM...NONE.
&&
$$
SHORT TERM...10/CD
LONG TERM....23/SK
AVIATION...10/CD
AREA FORECAST DISCUSSION
NWS MIAMI FL
1114 AM EST MON DEC 8 2014
.UPDATE...
AS NOTED IN THE MORNING DISCUSSION...THE COMBINATION OF STRONG
HIGH PRESSURE ALONG THE CANADIAN ATLANTIC COAST AND LOW PRESSURE
IN THE VICINITY OF BERMUDA HAS CREATED A STRONG AND PERSISTENT
PRESSURE GRADIENT AND WELL ESTABLISHED NORTHEAST FETCH ACROSS THE
WESTERN ATLANTIC EAST OF THE CAROLINAS WITH RECENT SCATTEROMETER
SATELLITE DERIVED WINDS INDICATING STRONG NORTHEASTERLY WINDS.
THESE CONDITIONS ARE FORECAST TO PRODUCE LONG-PERIOD
NORHTHEASTERLY SWELL THAT WILL CONTINUE TO ENTER THE ATLANTIC
WATERS EAST OF PALM BEACH COUNTY TODAY. THE LONG-PERIOD SWELL
WILL CONTINUE TO ENTER THE REGIONAL ATLANTIC WATERS TONIGHT INTO
TUESDAY AND FORECAST TO CONTINUE THROUGH AT LEAST WEDNESDAY. THIS
PROMPTED THE ISSUANCE OF A HIGH RISK OF RIP CURRENTS FOR THE
ATLANTIC COAST BEACHES THROUGH WEDNESDAY EVENING. IN ADDITION...A
HIGH SURF ADVISORY WILL LIKELY BE NECESSARY...MAINLY FOR THE
BEACHES EAST OF PALM BEACH COUNTY WITH CURRENT SURF HEIGHTS
FORECAST TO BE NEAR 10 FEET BY EARLY TUESDAY MORNING. A HIGH SURF
ADVISORY WILL LIKELY BE ISSUED THIS AFTERNOON FOR THE PALM BEACH
COUNTY BEACHES TONIGHT THROUGH WEDNESDAY EVENING.
60
&&
.PREV DISCUSSION... /ISSUED 627 AM EST MON DEC 8 2014/
AVIATION...
RECENTLY ANIMATED IR2 IMAGERY SHOWED A LARGE SHIELD OF LOW STRATUS
ACROSS MUCH OF SOUTH FLORIDA ACROSS THE INTERIOR AND GULF REGIONS.
AT THIS TIME...IT APPEARS THE MAIN ISSUE FROM THIS STRATUS DECK
WILL BE MVFR/IFR CIGS, ESPECIALLY OVER APF AND PBI. THIS DECK
SHOULD BEGIN TO LIFT AND BURN OFF THROUGH THE MID-MORNING PERIOD
WITH A RETURN OF VFR CONDITIONS. WINDS WILL REMAIN LIGHT OUT OF
THE NNW TODAY THEN NE AT SITE APF LATER TONIGHT INTO TUESDAY
MORNING. /85
PREV DISCUSSION... /ISSUED 406 AM EST MON DEC 8 2014/
SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH TONIGHT...USHERING IN AN EXTENDED
PERIOD OF NORTHWEST WINDS AND BELOW NORMAL TEMPERATURES. HIGH
PRESSURE WILL DOMINATE.
SHORT TERM /TODAY THROUGH WEDNESDAY/ ...
BEHIND YESTERDAYS COLD FRONT...TEMPS EARLY THIS MORNING ARE QUITE
A BIT COOLER THAN PREV FEW MORNINGS...WITH LOW 60S ALONG THE
COASTS AND 50S ELSEWHERE. LOW STRATUS/SOME VSBY RESTRICTIONS IS
PUSHING SOUTHWARD INTO GLADES AND HENDRY COUNTIES. HOW FAR SOUTH
THIS CLOUD LAYER ADVANCES IS UNCERTAIN...BUT IT APPEARS THAT AT
LEAST NORTH OF A NAPLES TO BOCA RATON LINE...MOSTLY CLOUDY
CONDITIONS WILL PREVAIL INTO LATE MORNING. NW WINDS WILL TURN NE
THIS AFTERNOON...AND TEMPERATURES SHOULD RISE TO NEAR
NORMAL...MID/UPR 70S. NE FLOW WILL BRING SOME LOW-LEVEL MOISTURE
DOWN THE E FL COASTLINE...AND THIS COULD BE ENOUGH TO BRING INLAND
A FEW SHOWERS INTO PALM BEACH COUNTY. THESE MAY CONTINUE INTO
EARLY TUESDAY...BEFORE A COLD FRONT BRINGS MUCH DRIER AIR INTO THE
REGION. MINIMA TONIGHT WILL ALSO BE NEAR AVERAGE FOR EARLY
DECEMBER...MAINLY IN THE MID/UPR 50S...WITH SOME LOW 60S ACROSS
THE EASTERN METROPOLITAN AREAS.
A POTENT SHORTWAVE TROUGH WILL DIVE THROUGH THE GREAT LAKES TODAY
AND INTO THE CENTRAL APPALACHIANS TONIGHT. BEHIND THE
TROUGH...CANADIAN HIGH PRESSURE WILL EXPAND THROUGH THE PLAINS AND
EVENTUALLY THE MISSISSIPPI RIVER VALLEY. THE TROUGHS ATTENDANT
SURFACE CDFNT WILL MOVE THROUGH THE OHIO VALLEY TODAY...WHILE
SURFACE LOPRES DEVELOPS OFF CAROLINAS. THE LOW WILL ACCELERATE THE
ARRIVAL OF THE FRONT INTO SOUTH FLORIDA AND ALSO INCREASE THE
COLD-AIR ADVECTION ASSOCIATED WITH IT. SIGNIFICANT COOLING WILL
OCCUR BY TUESDAY NIGHT AS THE UPPER TROUGH AXIS QUIETLY PASSES
BY. MINIMAS SHOULD REACH 40S OVER THE INTERIOR...WITH LOW 50S ALL
THE WAY TO THE EAST COAST. WIND CHILL VALUES WILL BE A FEW DEGREES
LOWER THAN THE TEMPERATURE OVERNIGHT. WEDNESDAY...CANADIAN RIDGE
BECOMES MORE ENTRENCHED OVER SOUTH FLORIDA...AND MAXIMA WILL HOLD
IN THE 60S.
SIGNIFICANT NE SWELL BEING TO ARRIVE IN SOUTH FLORIDA WATERS
TODAY /SEE DETAILS IN THE MARINE DISCUSSION BELOW/. THIS WILL LEAD
TO SIGNIFICANT RIP CURRENTS ALONG ATLANTIC BEACHES THROUGH AT
LEAST MID-WEEK. IN ADDITION...HIGH SURF MAY WARRANT AN ADVISORY
TUESDAY OR WEDNESDAY...AND BEACH EROSION/MINOR COASTAL
FLOODING...ARE ALSO POTENTIAL HAZARDOUS.
LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/ ...
AFOREMENTIONED SHORTWAVE TROUGH WILL DEEPEN FURTHER AND EVOLVED
INTO CLOSED H5 LOPRES OVER NE CONUS. THE FEATURE WILL THEN
STALL...AT LEAST INTO THE WEEKEND. MEANWHILE...EXPANSIVE SFC
RIDGE WILL REMAIN CENTERED NORTHWEST OF THE STATE. FOR SOUTH
FLORIDA...THIS MEANS EXPECT AN EXTENDED PERIOD OF NORTHWEST WINDS
WITH A COOL CANADIAN AIRMASS CONTINUING TO FILTER IN MUCH OF THE
WEEK. SKIES WILL BE MAINLY CLEAR. OVERNIGHT LOWS SHOULD MAINLY BE
IN 40S INTERIOR/50S METROPOLTIAN AREAS...WITH DAYTIME HIGHS IN THE
UPPER 60S TO LOW 70S. ALTHOUGH LONG-RANGE MODELS GENERALLY AGREE
ON THIS PATTERN CONTINUING INTO THE WEEKEND...LATEST ECMWF RUN
BRINGS ADDITIONAL REINFORCEMENTS OF COOL AIR DOWN THE PENINSULA.
IF THIS PANS OUT...FORECAST TEMPERATURES MAY BE SEVERAL DEGREES TO
WARM FOR THE END OF THE WEEK.
AVIATION...
STILL MONITORING A SHIELD OF LOW CIGS PUSHING SOUTH ACROSS THE
CENTRAL FLORIDA PENINSULA PER THE LATEST MICRON SATELLITE IMAGERY.
THE TIMING AND EXACT EXTENT OF THE SOUTHERN PROPAGATION OF THIS
SHIELD REMAINS IN QUESTION. LATEST HRRR AND SREF CIG HEIGHT
PROBABILITIES KEEP THE MAJORITY OF THE LOW CIGS ACROSS THE
INTERIOR WITH THE PERIPHERY OF WHICH EXTENDING TO BOTH THE
ATLANTIC AND GULF COASTS...POSSIBLY AFFECTING THE TAF SITES. KEPT
ANY MVFR/IFR CIGS OUT OF TAFS FOR NOW DUE TO UNCERTAINTY BUT WILL
CONTINUE TO MONITOR AND AMEND AS NECESSARY. OTHERWISE...LIGHT
NORTH-NORTHWESTERLY FLOW WILL PREVAIL AT THE EAST COAST SITES
THROUGH THE MORNING WITH NORTHEASTERLY FLOW AT KAPF.
MARINE...
IMPRESSIVE FETCH GENERATED BY LOPRES WEST OF BERMUDA IS BRINGING
NELY SWELL DOWN THE FLORIDA PENINSULA EARLY THIS MORNING. WAVE
HEIGHTS ARE ALREADY EXCEEDING 10 FT OFFSHORE THE MELBOURNE/CAPE
CANAVERAL AREA...AND WILL LIKELY REACH WATERS OFF PALM BEACH
COUNT THIS AFTERNOON...THEN THE REMAINDER OF ATLANTIC WATERS
TONIGHT. SMALL CRAFT ADVISORIES HAVE BEEN ISSUED ACCORDINGLY. THE
5 TO 8 FOOT SWELL WILL PERSIST TUESDAY INTO WEDNESDAY...LEADING TO
A CONTINUATION OF HAZARDOUS MARINE CONDITIONS. WAVES IN THE GULF
STREAM MAY EXCEED 13 FEET DURING THIS TIME.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 76 61 73 50 / 30 10 10 0
FORT LAUDERDALE 78 62 75 54 / 10 0 10 0
MIAMI 78 62 75 53 / 10 0 0 0
NAPLES 74 58 71 50 / 10 0 0 0
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK THROUGH WEDNESDAY EVENING FOR FLZ168-172-
173.
AM...SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 7 PM EST
WEDNESDAY FOR AMZ651-671.
SMALL CRAFT ADVISORY UNTIL 7 PM EST WEDNESDAY FOR AMZ650-670.
HIGH RIP CURRENT RISK THROUGH WEDNESDAY EVENING FOR AMZ630.
GM...NONE.
&&
$$
SHORT TERM...85/AG
LONG TERM....60/BD
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
323 PM CST MON DEC 8 2014
.SHORT TERM...
317 PM CST
THROUGH WEDNESDAY...
LIGHT RAIN OR DRIZZLE AND SOME PATCHY LIGHT SNOW ALL ARE LIKELY
TO MAKE AN APPEARANCE THIS EVENING...ALONG WITH AREAS OF FOG.
WATER VAPOR SATELLITE IMAGE SHOWS TWO UPPER CIRCULATIONS THAT WILL
CROSS THE AREA...AND MODEL VORTICITY FIELDS ALOFT AND RH FIELDS AT
LOWER LEVELS ALL SUPPORT THE IDEA OF PATCHY AREAS OF
PRECIPITATION. AS OF LATE AFTERNOON MOST AREAS ARE IN THE MIDDLE
TO UPPER 30S...AND PRECIP CHANCES SHOULD DIMINISH AS COLDER AIR
APPROACHES...SO LITTLE IF ANY FROZEN PRECIPITATION WOULD BE
EXPECTED TO ACCUMULATE.
BY MORNING THE AXIS OF THE UPPER LONGWAVE IS WELL TO OUR EAST...AND
UPPER SHORTWAVE ENERGY BEGINS TO EXIT THE AREA AS WELL. ONLY AT LOW
LEVELS DO RH FIELDS SUGGEST CONTINUED SATURATION...SO WILL TREND
POPS DOWNWARD TO BELOW MENTIONABLE LEVELS BY DAYBREAK EXCEPT
DOWNWIND FROM THE LAKE IN NORTHWEST INDIANA AT THE END OF A
NORTHWEST FETCH. EVEN THAT AREA APPEARS TO DRY OUT BY LATE
TOMORROW AS WINDS CONTINUE VEERING NORTHEASTERLY AND LOW LEVELS
DRY CONSIDERABLY.
CLOUDINESS PERSISTS SOUTH OF THE LAKE LATE TOMORROW INTO TOMORROW
NIGHT...BUT AREAS WEST CLEAR OUT A BIT. THIS ACCOUNTS FOR A FEW
DEGREE TEMPERATURE DIFFERENCE IN TUESDAY NIGHT LOWS BETWEEN MORE
CLEAR AND MORE OVERCAST AREAS. WEDNESDAY CONTINUES COOL...BUT NOT
UNSEASONABLY SO...WITH GRADUALLY CLEARING SKIES.
LENNING
&&
.LONG TERM...
317 PM CST
WEDNESDAY NIGHT THROUGH TUESDAY...
THE REMAINDER OF THE WEEK AND ESPECIALLY THE WEEKEND DO NOT LOOK
TOO BAD AT ALL FOR MID DECEMBER. COMPARED TO LAST MONTH...THE
STRETCH OF DAYS STARTING ON FRIDAY THE 12TH LOOKS TO BE FROM 10 TO
20 DEGREES WARMER THAN THE SAME PERIOD FROM LAST MONTH. SO THE
MIDDLE PORTIONS OF NOVEMBER AND DECEMBER APPEAR TO BE SWAPPED THIS
YEAR.
MODELS ARE IN REASONABLE THOUGH NOT PERFECT AGREEMENT THAT THE LARGE
UPPER TROUGH NOW OVERHEAD WILL MOVE INTO THE EASTERN CONUS AND ALLOW
A BROAD RIDGE FROM THE SFC TO UPPER LEVELS TAKE ITS PLACE. THIS
RIDGING WITH ITS DRY AND MILD WEATHER APPEARS TO PERSIST AT LEAST
INTO THE MIDDLE PART OF THE WEEKEND WHILE SLOWLY DRIFTING EAST.
BY EARLY SUNDAY MODELS START TO SUGGEST A RETURN OF BETTER MOISTURE
AHEAD OF AN APPROACHING FRONTAL ZONE ACROSS THE PLAINS AND WEST OF
THE RIDGE. CONFIDENCE ON THE TIMING OF THIS MOIST SOUTHERLY FLOW
INTO THE LOCAL AREA IS LOW...SO HAVE ELECTED TO INCLUDE INCREASED
POPS BY SUNDAY AND MONDAY BUT ALL IN THE FORM OF LIGHT RAIN.
LENNING
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* LIGHT DRIZZLE AND FOG REDUCING VIS TO MVFR/IFR THIS AFTERNOON.
* IFR CEILINGS BECOMING LOW END MVFR THIS EVENING...SLOWLY
IMPROVING THROUGH TUESDAY MORNING.
* SCATTERED SNOW SHOWERS POSSIBLE THIS EVENING/TONIGHT.
* SOUTHWEST WINDS BECOMING WEST THIS EVENING...AND NORTHWEST
TONIGHT.
RODRIGUEZ
//DISCUSSION...UPDATED 18Z...
AREA OF PRECIP WHICH MOVED ACROSS THE AREA THIS MORNING DEPARTING
TO THE EAST OF THE TERMINALS...WITH GYY STILL EXPERIENCING LIGHT
RAIN. WITH THE DEPARTURE OF THIS PRECIP...SATURATED CONDITIONS
WILL RESULT IN SOME DRIZZLE AND FOG THIS AFTERNOON. PATCHY DENSE
FOG ALREADY IN PLACE OVER NORTHERN ILLINOIS WILL LINGER FOR MOST
OF THIS AFTERNOON AND EARLY EVENING. SOME SLIGHT IMPROVEMENT WITH
VIS WILL BE POSSIBLE BUT WITH FOG NOT LIKELY CLEARING UNTIL FROPA
LATER THIS EVENING. SIMILAR TRENDS WILL OCCUR WITH THE CURRENT IFR
CEILINGS IN PLACE...NOT LIKELY OBSERVING A BETTER IMPROVING TREND
UNTIL FROPA LATER THIS EVENING. WITH THE ARRIVAL OF COLDER AIR
THIS EVENING AND A MID LEVEL DISTURBANCE...SCATTERED SNOW SHOWERS
DO APPEAR POSSIBLE ONCE AGAIN THROUGH A PORTION OF TONIGHT.
INCREASING NORTHWEST WINDS POST FROPA WILL OCCUR TONIGHT INTO
EARLY TUESDAY MORNING...WHILE AN IMPROVING TREND WITH CEILINGS
CONTINUES.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE WITH DRIZZLE/FOG THIS AFTERNOON...AND MEDIUM
HIGH CONFIDENCE WITH VIS TRENDS.
* HIGH CONFIDENCE WITH IFR CEILINGS...AND MEDIUM HIGH CONFIDENCE
WITH CEILING TRENDS THROUGH TUESDAY MORNING.
* MEDIUM HIGH CONFIDENCE OF SCATTERED SNOW SHOWERS THIS
EVENING...MEDIUM CONFIDENCE OF TIMING AND DURATION.
* HIGH CONFIDENCE WITH WIND SPEED/DIRECTION.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...VFR. NORTH WINDS.
WEDNESDAY...VFR. N WINDS.
THURSDAY...VFR. W WINDS BECOMING WSW.
FRIDAY...MAINLY VFR...THOUGH MVFR CIGS PSBL. SW WINDS.
SATURDAY...MAINLY VFR...THOUGH MVFR CIGS PSBL. S WINDS.
SUNDAY...MAINLY VFR. S WINDS.
MDB
&&
.MARINE...
227 PM CST
LOW PRESSURE IS OVER NORTHERN WISCONSIN AND IT WILL WEAKEN AS IT
MOVES ACROSS THE LAKE TONIGHT. WINDS TURN NORTHWEST BEHIND THE LOWS
COLD FRONT AND THEN THEY TURN NORTH AS HIGH PRESSURE BUILDS OVER
MINNESOTA. THE GRADIENT TIGHTENS BETWEEN THE HIGH AND LOW WITH 30 KT
NORTH WINDS EXPECTED ACROSS THE LAKE TOMORROW. WINDS AND WAVES WILL
INCREASE IN THE NEARSHORE WATERS SO HOISTED A SMALL CRAFT ADVISORY
BEGINNING EARLY TUESDAY MORNING. WINDS DIMINISH TUESDAY NIGHT AS
THE HIGH APPROACHES BUT LARGE WAVES WILL LINGER IN THE NSH ZONES.
HAVE MEDIUM CONFIDENCE IN HOW LONG THE HAZARDOUS WAVES WILL
LINGER...BUT HAVE THE SMALL CRAFT ADVISORY GOING INTO WEDNESDAY
NIGHT. NORTH WINDS BECOME NORTHWEST AS THE HIGH MOVES DOWN THE
MISSISSIPPI VALLEY WEDNESDAY NIGHT AND CONTINUE TO BACK TO SOUTHWEST
BY FRIDAY AFTERNOON. THE HIGH FINALLY SHIFTS EAST OVER THE OHIO
VALLEY SATURDAY WITH THE NEXT LOW FORMING OVER THE PLAINS SATURDAY
NIGHT.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...6 AM TUESDAY TO 9
PM WEDNESDAY.
SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742...9 AM TUESDAY TO 3
PM WEDNESDAY.
&&
$$
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[top]
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
249 PM CST Mon Dec 8 2014
.SHORT TERM...(Tonight)
ISSUED AT 248 PM CST MON DEC 8 2014
Cold front is pushing across central Illinois early this afternoon,
located just west of Peoria and Springfield as of 2 pm. Extensive
low cloud deck has been prevailing over the forecast area, with some
localized dense fog along and north of the I-74 corridor. Surface
observations showing visibilities and ceilings lifting behind the
front, and the back edge of the cloudiness covered about the eastern
third of Missouri. Well defined upper circulation evident on water
vapor imagery over northeast Iowa, and this is producing some light
rain and snow upstream from us.
Main question for this part of the forecast is how much clearing
will manage to take place. Lower clouds extend all the way back into
southern North Dakota. RAP model guidance and current trajectories
would suggest some clearing may take place over the far southwest
parts of the forecast area for a short period, but a secondary surge
of clouds is expected as the broad upper trough surrounding the
aforementioned circulation swings through the Midwest this evening.
Have kept the sky forecast on the pessimistic side and kept cloudy
skies in the grids for tonight. Much of the associated precipitation
should be just to our north, but will include some slight chance
PoP`s for the northeast CWA for this evening.
&&
.LONG TERM...(Tuesday through Monday)
ISSUED AT 248 PM CST MON DEC 8 2014
As the low pressure area weakens and gets absorbed into an east
coast system, a high pressure ridges will build into the area. This
ridge will dominate the weather over the area through Wednesday and
beyond. Some concern with lower level moisture remaining trapped
under the ridge Tue through Wed, so have increased cloud cover to go
mostly cloudy through Wed. As the center of the high pressure drops
south into the southern Miss river valley, the ridge will remain
over the area with dry weather through Thursday, the rest of the
week and into the weekend. The area will also remain dominated by
mid level cyclonic flow through the end of the week. Then mid level
ridging, that was building in the plains, will begin to dominate the
region for the weekend. Late in the weekend, the ridging will begin
to push east and this will allow a frontal system to move into the
area and bring rain to the region for Sun night and Monday.
With high pressure dropping into the area and cyclonic flow, temps
will remain cool for the next couple of days. But then as the high
pressure settles south and mid level ridging builds, temps will
begin to warm again. By the weekend, temps will warm to above
normal, with 50s expected Sat and Sun.
&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
ISSUED AT 1130 AM CST MON DEC 8 2014
Widespread IFR/LIFR conditions continue over the central Illinois
TAF sites at midday. Some modest improvement will take place this
afternoon as a cold front pushes east, reaching roughly KBMI/KDEC
around 20Z and KCMI around 21Z, at which point ceilings should
increase into MVFR range. RAP model showing some potential for
brief VFR conditions this evening, but ceilings should sink back
into MVFR range as a deep upper trough swings across the Midwest.
Have lingered these conditions through the end of the TAF period,
but humidity cross-sections off the NAM model suggest some
potential for the ceilings to break up from KSPI-KPIA late.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Geelhart
LONG TERM...Auten
AVIATION...Geelhart
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1211 PM CST MON DEC 8 2014
.SHORT TERM...
418 AM CST
THROUGH TONIGHT...
FOR THE REMAINDER OF THE NIGHT AND INTO THE MORNING HOURS...HAVE
BEEN TRACKING A BAND OF PCPN AHEAD OF A WEAK COLD FRONT TRACKING
ACROSS THE PLAINS AND INTO THE MIDWEST. PCPN AMOUNTS ASSOCIATED
WITH THE SYSTEM HAVE BEEN GENERALLY LIGHT WITH THE MOST STEADY AND
HEAVIER PCPN CONFINED TO A NARROW BAND WHICH IS APPROACHING THE I-39
CORRIDOR AS OF 4AM CST. THE PCPN BAND WILL BE STEADILY PROGRESSIVE
ACROSS THE CWA...WITH STEERING FLOW OF 35-40KT BEHIND THE ASSOCIATED
UPPER TROUGH. THE THERMAL PROFILE IS MAKING FOR A VERY DIFFICULT
PCPN TYPE FORECAST AS A VERY WARM LAYER ABOVE A SFC BASED INVERSION
IS +6 TO +7C PER THE 00Z SOUNDINGS FROM DVN AND ILX. MAKING MATTERS
EVEN MORE DIFFICULT IS A DRY LAYER COINCIDENT WITH THE WARM
LAYER...SO PCPN HAS BEEN HAVING A TOUGH TIME DEVELOPING OUT AHEAD OF
THE FORCING OF THE SFC FRONT AND UPPER LEVEL SHORT WAVE. SO...HAVE
BACKED OFF ON QPF AMOUNTS AS THE MEASURABLE PCPN WILL LIKELY BE
CONFINED TO A SHORT DURATION AS THE FRONT QUICKLY CROSSES THE
REGION. PCPN TYPE WILL BE THE MAIN FORECAST PROBLEM AS SFC TEMPS
HOVER RIDGE AROUND THE FREEZING MARK. SO...WILL CARRY A MIXED BAG
OF PCPN TYPES...INITIALLY SOLE LIGHT FREEZING RAIN...WHICH SHOULD
MIX WITH AND THEN TRANSITION OVER TO SLEET AND THEN MIXING WITH SOME
SNOW WITH THE STRONGEST MID LEVEL FORCING. FORECAST RH PROFILES AND
LATEST RADAR IMAGERY SHOW THAT THERE SHOULD BE A RELATIVELY SHARP
CUT-OFF TO THE MEASURABLE PCPN BEFORE TRANSITIONING OVER TO A PERIOD
OF DRIZZLE AS A SATURATED LAYER BELOW 8KFT BELOW A DRY LAYER ALOFT
LINGERS OVER THE AREA THROUGH THE AFTERNOON AND POSSIBLY INTO THE
EVENING. TEMPERATURES ARE EXPECTED TO CLIMB INTO THE MIDDLE 30S BY
LATE MORNING...FOLLOWING THE FROPA...SO FREEZING DRIZZLE WILL BE
LESS LIKELY AND ULTIMATELY ANTICIPATE THAT TEMPERATURES SHOULD TOP
OUT IN THE UPPER 30S THIS AFTERNOON. BY EARLY THIS EVENING...THE
SFC FRONT SHOULD PUSH EAST INTO INDIANA AND LOWER MICHIGAN WITH HIGH
PRESSURE BUILDING ACROSS THE NRN PLAINS AND UPPER MISSISSIPPI
VALLEY. NORTHERLY WINDS WILL SET UP...BRINGING SOME LAKE EFFECT
SNOW SHOWERS INTO NWRN INDIANA...BUT SINCE THE AIRMASS IS NOT VERY
COLD BEHIND THE FRONT...EXPECT ONLY LIGHT AMOUNTS OF LAKE EFFECT
SNOW WITH ONLY LIGHT ACCUMULATIONS LIKELY. AS THE HIGH PRESSURE
BUILDS ACROSS THE MISSISSIPPI VALLEY AND INTO THE UPPER
MIDWEST...SKIES SHOULD CLEAR OUT AND TEMPERATURES TONIGHT SHOULD
DROP INTO MIDDLE 20S TO AROUND 30F.
KREIN
&&
.LONG TERM...
418 AM CST
TUESDAY THROUGH SUNDAY...
FOR MUCH OF THE EXTENDED FORECAST PERIOD...A HIGH AMPLITUDE...SLOWLY
PROGRESSIVE PATTERN WILL SET UP WITH A BUILDING RIDGE OVER THE WRN
CONUS AND A DEEP UPPER TROUGH CARING OUT OVER THE ERN CONUS AND A
DEEP SFC LOW DEVELOPING OFF THE THE MID ATLANTIC COAST. THE GENERAL
TRENDS FOR THE NEXT SEVERAL DAYS SHOULD BE FOR THE UPPER TROUGH TO
DEEPEN TO A CLOSED LOW OVER NEW ENGLAND BY THURSDAY AS THE UPPER
RIDGE BUILDS OVER THE NRN PLAINS. A STRONG UPPER RIDGE OVER THE
ATLANTIC OCEAN WILL KEEP THE UPPER LOW FROM PROGRESSING
EASTWARD...WHILE THE UPPER RIDGE CONTINUES TO BUILD ACROSS THE
NORTHERN PLAINS AND TO THE UPPER MISSISSIPPI VALLEY AND WESTERN
GREAT LAKES BY FRIDAY. THIS WILL LEAD TO A WARMING TREND THROUGH
THE WEEK...WITH TEMPERATURES REACHING INTO THE LOWER 40S BY FRIDAY
AND THE MIDDLE TO UPPER 40S FOR THE WEEKEND. STILL FEEL THAT THE
GUIDANCE MAY BE A BIT TOO CONSERVATIVE WITH TEMPERATURES FOR THE
WEEKEND GIVEN THE STRENGTH OF THE RIDGE...BUT ON THE OTHER
HAND...THE LONGER RANGE MODELS HAVE BEEN PUSHING BACK THIS WARMING
TREND FARTHER INTO THE EXTENDED FORECAST PERIOD...SO...CONFIDENCE IS
NOT VERY HIGH THAT WE WILL SEE TEMPERATURES IN THE 50S FOR THE
WEEKEND...BUT IF THE DETERMINISTIC GUIDANCE WERE TO VERIFY...MAX
TEMPS FOR THE WEEKEND COULD BE IN THE 50S...OR AT THE VERY
LEAST...SHOULD BE WELL ABOVE NORMAL.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* LIGHT DRIZZLE AND FOG REDUCING VIS TO MVFR/IFR THIS AFTERNOON.
* IFR CEILINGS BECOMING LOW END MVFR THIS EVENING...SLOWLY
IMPROVING THROUGH TUESDAY MORNING.
* SCATTERED SNOW SHOWERS POSSIBLE THIS EVENING/TONIGHT.
* SOUTHWEST WINDS BECOMING WEST THIS EVENING...AND NORTHWEST
TONIGHT.
RODRIGUEZ
//DISCUSSION...UPDATED 18Z...
AREA OF PRECIP WHICH MOVED ACROSS THE AREA THIS MORNING DEPARTING
TO THE EAST OF THE TERMINALS...WITH GYY STILL EXPERIENCING LIGHT
RAIN. WITH THE DEPARTURE OF THIS PRECIP...SATURATED CONDITIONS
WILL RESULT IN SOME DRIZZLE AND FOG THIS AFTERNOON. PATCHY DENSE
FOG ALREADY IN PLACE OVER NORTHERN ILLINOIS WILL LINGER FOR MOST
OF THIS AFTERNOON AND EARLY EVENING. SOME SLIGHT IMPROVEMENT WITH
VIS WILL BE POSSIBLE BUT WITH FOG NOT LIKELY CLEARING UNTIL FROPA
LATER THIS EVENING. SIMILAR TRENDS WILL OCCUR WITH THE CURRENT IFR
CEILINGS IN PLACE...NOT LIKELY OBSERVING A BETTER IMPROVING TREND
UNTIL FROPA LATER THIS EVENING. WITH THE ARRIVAL OF COLDER AIR
THIS EVENING AND A MID LEVEL DISTURBANCE...SCATTERED SNOW SHOWERS
DO APPEAR POSSIBLE ONCE AGAIN THROUGH A PORTION OF TONIGHT.
INCREASING NORTHWEST WINDS POST FROPA WILL OCCUR TONIGHT INTO
EARLY TUESDAY MORNING...WHILE AN IMPROVING TREND WITH CEILINGS
CONTINUES.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE WITH DRIZZLE/FOG THIS AFTERNOON...AND MEDIUM
HIGH CONFIDENCE WITH VIS TRENDS.
* HIGH CONFIDENCE WITH IFR CEILINGS...AND MEDIUM HIGH CONFIDENCE
WITH CEILING TRENDS THROUGH TUESDAY MORNING.
* MEDIUM HIGH CONFIDENCE OF SCATTERED SNOW SHOWERS THIS
EVENING...MEDIUM CONFIDENCE OF TIMING AND DURATION.
* HIGH CONFIDENCE WITH WIND SPEED/DIRECTION.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...VFR. NORTH WINDS.
WEDNESDAY...VFR. N WINDS.
THURSDAY...VFR. W WINDS BECOMING WSW.
FRIDAY...MAINLY VFR...THOUGH MVFR CIGS PSBL. SW WINDS.
SATURDAY...MAINLY VFR...THOUGH MVFR CIGS PSBL. S WINDS.
SUNDAY...MAINLY VFR. S WINDS.
MDB
&&
.MARINE...
305 AM CST
STRONG HIGH PRESSURE IS POSITIONED OVER SOUTHERN QUEBEC THIS MORNING
AND WILL BE GRADUALLY MOVING OFFSHORE INTO THE NORTH ATLANTIC OVER
THE NEXT FEW DAYS. LOW PRESSURE IS MOVING EASTWARD ACROSS FAR
NORTHERN MINNESOTA AND WILL BE WEAKENING/BROADENING AS IT MOVES
ACROSS THE GREAT LAKES TODAY AND TONIGHT. IN THE MEANTIME...THE
PRESSURE GRADIENT HAS TIGHTENED UP ACROSS LAKE MICHIGAN AND
SOUTHERLY WINDS REMAIN AROUND 30 KT ACROSS CENTRAL AND NORTHERN
SECTIONS. STILL CANNOT RULE OUT SOME GALE FORCE GUSTS OVER THE NEXT
FEW HOURS. A COLD FRONT WILL APPROACH THE LAKE TODAY WITH WINDS
TURNING MORE SOUTHWESTERLY AND EASING THROUGH THE DAY AS THE
PRESSURE GRADIENT SLACKENS AHEAD OF IT. WILL GO AHEAD AND KEEP THE
SMALL CRAFT ADVISORY FOR THE NORTHERN TWO IL NEARSHORE ZONES THROUGH
MID MORNING WITH WAVES ON A DOWNWARD TREND LATER THIS MORNING.
THE COLD FRONT WILL CROSS THE LAKE LATE THIS AFTERNOON/EARLY THIS
EVENING TURNING WINDS NORTHWESTERLY AS SPEEDS INCREASE. HIGH
PRESSURE WILL BE APPROACHING SO WINDS WILL TURN NORTHERLY TUESDAY
MORNING AND REMAIN GUSTY BEFORE SLOWLY DIMINISHING WEDNESDAY NIGHT.
WILL LIKELY NEED A SMALL CRAFT ADVISORY FOR ALL AREAS
TUESDAY...THOUGH A LATER START MAY BE WARRANTED ACROSS THE ILLINOIS
WATERS AS IT WILL TAKE A BIT LONGER FOR WAVES TO BUILD. WILL HOLD
OFF ON THIS FOR NOW SO THAT TIMING CAN BE REFINED. THE HIGH WILL BE
SLOW TO MOVE AS IT CONSOLIDATES SOUTHWARD OVER THE LOWER OHIO VALLEY
INTO MID WEEK. BROAD RIDGING WILL CROSS THE LAKE INTO LATE WEEK
KEEPING WINDS ON THE LIGHT SIDE.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1132 AM CST Mon Dec 8 2014
.UPDATE...
ISSUED AT 943 AM CST MON DEC 8 2014
Back edge of the rain has reached a Bloomington to Pana line, and
AWIPS timing tool has it out of most of the state by noon except
along the Wabash River. Main cold front moving through eastern
Iowa and northern Missouri, and should be passing through our area
around mid afternoon. Bulk of the afternoon should be dry, but
higher resolution models are suggesting some light drizzle or rain
may occur along the front, so will need to keep an eye on that.
With extensive cloud cover, have lowered highs by a degree or two
across the board.
&&
.SHORT TERM...(Today)
ISSUED AT 303 AM CST MON DEC 8 2014
Satellite and radar images indicate the clipper is progressing into
the western Great Lakes as advertised, with a warm front extending
southeast into northern Illinois and a cold front extending
southwest into western Iowa/Nebraska. Ahead of the warm front, rain
showers have already developed all the way to I-57 in our forecast
area. Several bands of rain will move east across the forecast area
today. The primary period of lift seems focused in a 2-3 hour
window earlier this morning, with the leading edge of that band just
reaching GBG around 0830z/230am. Precip amounts will remain light up
to a tenth of an inch total. The cold front will move across IL this
afternoon, helping to keep scattered showers going into the
afternoon. However, colder air aloft will allow some of the precip
to possibly change over to snow north of I-74. No accumulation would
develop, but flakes of snow could develop. Soundings do not show
much in the way of ice crystals to feed into the lower layer of
moisture, so drizzle may result, but will introduce a slight chance
of a rain-snow mix this afternoon across the north.
Air temps at the sensors at 3am this morning are hovering at or
just above freezing across our northern counties, with GBG/CMI/DNV
our only primary OB sites still at freezing. Freezing temps do
extend north toward Pontiac, Princeton and Kankakee. Upstream OBS to
the west-northwest are showing a warm nose of air flowing northward
during the rain and just behind the primary line of rain. Despite
sensors showing mostly above freezing, we can not rule out some
icing of elevated surfaces and on cars or colder objects. Some
sidewalks or bridges and secondary roads could also get a thin layer
of ice tonight across our north from Galesburg to Lacon to
Champaign/Danville. We do not expect the need for any headlines for
ice, as the warmer air behind the rain should help to melt any ice
that does form in a short time.
Clouds will remain entrenched across the area today. The lack of sun
and only modest warming behind the warm front and line of showers,
highs will top out in the low 40s north with upper 40s south.
&&
.LONG TERM...(Tonight through Sunday)
ISSUED AT 303 AM CST MON DEC 8 2014
Upper low spinning over the upper Midwest will continue to affect
Central Illinois going into tonight, with drizzle and light snow
possible on the back end of the system, mainly east of I-57.
Although high pressure is building into the region behind the
exiting low, stratus stretching back west of the Missouri River
Basin an indicator that the significant llvl moisture is not going
anywhere quickly. Moisture getting trapped underneath a persistent
inversion may keep the clouds around at least through Tuesday, and
potentially a bit longer than that. Models have not had any luck
with handling the low level moisture and even more than the sky
cover, the stratus will have ramifications in the temperature
forecast as well. Pulling the highs down a degree or two for
Tuesday from prev forecast...and less aggressive with the adjust
for Wednesday as the forecast is already on the cooler side of
MOS.
Temps slowly moderate through the end of the week and by Friday, a
southerly push to the winds brings some WAA back into the region and
temps up above normals in the low to mid 40s, and even the upper
40s for Saturday. Pops showing up later in the weekend with the
next system approaching end of Day 7/8. ECMWF rather interesting
in breaking up the upper vort into two maxes whereas the energy in
the GFS is more elongated in a narrow trof, at least a little bit
longer before it also breaks. Both producing QPF, the ECMWF more
diffuse and widespread, but not completely sold on the handling
of the low. Current handling would trend to a gap in the QPF,
further complicating the forecast. Slights in for Sun night.
&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
ISSUED AT 1130 AM CST MON DEC 8 2014
Widespread IFR/LIFR conditions continue over the central Illinois
TAF sites at midday. Some modest improvement will take place this
afternoon as a cold front pushes east, reaching roughly KBMI/KDEC
around 20Z and KCMI around 21Z, at which point ceilings should
increase into MVFR range. RAP model showing some potential for
brief VFR conditions this evening, but ceilings should sink back
into MVFR range as a deep upper trough swings across the Midwest.
Have lingered these conditions through the end of the TAF period,
but humidity cross-sections off the NAM model suggest some
potential for the ceilings to break up from KSPI-KPIA late.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Geelhart
SHORT TERM...Shimon
LONG TERM...HJS
AVIATION...Geelhart
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
422 PM EST MON DEC 8 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 304 PM EST MON DEC 8 2014
LATEST WATER VAPOR IMAGERY AND RUC ANALYSIS THE SHOW SHORTWAVE TROF
MOVING ACROSS THE UPPER GREAT LAKES THIS AFTERNOON. MODELS INDICATE
BEST ISENTROPIC ASCENT...MOISTURE TRANSPORT AND DEEP LAYER Q-VECT
CONVERGENCE HAS SHIFTED EAST WITH MAIN SNOW BAND AHEAD OF THE SFC-8H
TROF OVER CENTRAL UPPER MI. IT/S POSSIBLE THERE MAY BE SOME PATCHY
-FZDZ LATE THIS AFTERNOON BEHIND THE SNOW BAND WITH MID-LVL DRYING
AND LOW-LVL MOISTURE TOO SHALLOW TO REACH THE -10C ISOTHERM...BUT
NOT SURE IF THE FZDZ WILL BE SIGNIFICANT ENOUGH TO INCLUDE IN FCST
GRIDS THIS EVENING.
MODELS INDICATE THAT N TO NW WINDS WILL STRENGTHEN TONIGHT BEHIND
DEPARTING LOW PRES TONIGHT. COOLING LOW-LEVEL AIR MASS MAY SUPPORT
SOME LAKE ENHANCED SNOW FOR A BRIEF TIME THIS EVENING.
HOWEVER...SNOWFALL IS EXPECTED TO BE LIGHT FOR THE FOLLOWING
REASONS...850MB TEMPS (AROUND -6C) ARE MARGINAL FOR ENHANCEMENT
WHILE DEEPER MOISTURE IS AROUND...LOW-LEVEL FLOW IS NOT STRONGLY
CYCLONIC...AND DGZ IS ABOVE THE UPWARD MOTION AND THE DEEPER
MOISTURE. UPSLOPE/OROGRAPHIC MOTION MAY BE THE DRIVING COMPONENT
AIDING SNOWFALL...AND WHERE THAT IS MAXIMIZED...EXPECT GENERALLY 1-2
INCHES OF SNOW TONIGHT OVER HIGHER TERRAIN NEAR LAKE SUPERIOR.
INCREASED SUBSIDENCE AND LOWERING OF INVERSION HGTS AHEAD OF THE
BUILDING MID-LVL RDG UPSTREAM MAY ALSO CONTRIBUTE TO A BRIEF PD OF
UPSLOPE FZDZ LATE TONIGHT OVER THE NRN TIER COUNTIES IN NRLY FLOW
LATE TONIGHT...BUT NAM SNDGS SHOW THE SHALLOW MOIST LAYER COOLING TO
-10C BY SUNRISE WHICH SHOULD AGAIN SUPPORT MAINLY LIGHT
SNOW/FLURRIES. SINCE FZDZ THREAT IS UNCERTAIN AND LOOKS TO BE BRIEF
IF IT DOES OCCUR WL LEAVE IT OUT OF GRIDS FOR NOW. LOOK FOR MIN
TEMPS RANGING FROM THE LOWER 20S INTERIOR WEST TO UPPER 20S EAST
HALF.
1034 MB SFC RIDGE BUILDING IN FROM THE WEST SHOULD WEAKEN THE PRES
GRADIENT AND THUS ALLOW NRLY WINDS TO DIMINISH ACROSS THE AREA BY
AFTERNOON. CONTINUED LOWERING OF INVERSION BASES BLO 3KFT WILL
QUICKLY DIMINISH ANY REMAINING LIGHT UPSLOPE SHSN TO FLURRIES BY
LATE MORNING. LOOK FOR HIGHS RANGING FROM THE LOWER TO MID 20S WEST
TO LOWER 30S EAST HALF.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 422 PM EST MON DEC 8 2014
DRY WEATHER WILL BE THE RULE THROUGH SATURDAY MORNING...WITH HIGH
PRESSURE FROM THE SFC-500MB. BOTH THE GFS AND ECMWF BRING SOME
MOISTURE BACK TO THE AREA DURING THE DAY SATURDAY...AS THE SFC RIDGE
EXITS E TO THE LOWER GREAT LAKES AND THE AXIS OF THE 500MB RIDGE
MOVES ACROSS THE UPPER GREAT LAKES. LOOK FOR SLOWLY INCREASING W-SW
WINDS DURING THE DAY SATURDAY WITH 850MB TEMPS WARMING TO 9 TO 12C.
THIS WILL BE QUITE A CHANGE FROM THE CURRENT VALUES WHICH ARE
HOVERING AROUND -4C.
THE MAIN CONCERN FOR THIS PERIOD WILL COME IN SATURDAY THROUGH
MONDAY. AS MOISTURE INCREASES...LIGHT WAA WILL LIKELY OVERSPREAD THE
CWA. KEPT THE MENTION OF PATCHY FOG AS WELL FOR THIS WILL BE IN
ADVANCE OF THE ELONGATED SFC LOW OVER THE N AND CENTRAL PLAINS AT
00Z SUNDAY WITH THE HIGH DEW POINTS OVER THE MELTING SNOWPACK. THE
12Z RUNS OF THE ECMWF AND GFS BOTH HAVE THE LOW OVER MN AT 12Z
SUNDAY...THEN SHIFTING ACROSS UPPER MI/LAKE SUPERIOR/CENTRAL ONTARIO
SUNDAY NIGHT. WITH LOW TEMPERATURES FALLING INTO THE MID 20S TO LOW
30S...THE POTENTIAL EXISTS FOR FREEZING RAIN OR FREEZING DRIZZLE.
WILL CONTINUE TO FOCUS ON THIS PERIOD...AND ADJUST AS NEEDED AS THE
TIME NEARS.
LOOK FOR THE COLD AIR TO SURGE IN BEHIND THE EXITING LOW/COLD FRONT
SUNDAY NIGHT INTO MONDAY...WITH PRECIP TURNING ALL BACK TO SNOW BY
MONDAY EVENING AT THE LATEST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1252 PM EST MON DEC 8 2014
LOW LEVEL MOISTURE ACCOMPANYING A LOW PRES SYSTEM MOVING THROUGH THE
AREA WILL RESULT IN IFR CIGS AND SCT -SHSN THIS AFTERNOON. IFR
CONDITIONS SHOULD PERSIST TONIGHT WITH SNOW PICKING UP FOR A TIME
UNDER STRENGTHENING UPSLOPE NNW-N WINDS. THERE MAY BE SOME
IMPROVEMENT AT KCMX LATE TONIGHT AS UPSLOPING DIMINISHES AND SOME
MINOR DIURNAL IMPROVEMENT AT KIWD AND KSAW TUE MORNING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 304 PM EST MON DEC 8 2014
BEHIND THE LOW...N TO NW WINDS RAMP UP TONIGHT...AIDED BY PRES RISES
APPROACHING FROM THE NW. MAGNITUDE OF PRES RISES SUGGESTS POTENTIAL
FOR A FEW HRS WHEN WINDS MAY GUST TO NEAR 35KT FROM NCNTRL TO SCNTRL
LAKE SUPERIOR. WINDS WILL DIMINISH FROM W TO E TUE AS HIGH PRES
RIDGE APPROACHES. WITH THE HIGH PRES RIDGE ARRIVING OVER THE UPPER
LAKES TUE NIGHT/WED...LIGHTER WINDS UNDER 20KT ARE EXPECTED... AND
THESE LIGHTER WINDS SHOULD LINGER ON THRU THU AND POSSIBLY FRI AS
WELL.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...KF
AVIATION...VOSS
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
353 PM EST MON DEC 8 2014
.SHORT TERM...THROUGH TONIGHT
19Z WATER VAPOR IMAGERY SHOWS WELL-DEFINED COMPACT MIDLEVEL WAVE
OVER THE MN/IA BORDER SPINNING SEWD. UPPER LEVEL MOISTURE WAS
PRESENT DOWNSTREAM OF THIS FEATURE OVER IN AND MI. MIDLEVEL
FRONTOGENESIS WAS SUPPORTING A NORTH/SOUTH ORIENTED SWATH OF LIGHT
TO MODERATE PRECIP OVER WESTERN MI AND NORTHERN IN...MOVING NEWD.
THERE WAS A SHARP LOW-LEVEL MOISTURE GRADIENT IN PLACE AS EVIDENCED
BY QUICKLY LOWERING CEILINGS AT THE ONSET OF PRECIPITATION. NWP IS
IN GOOD AGREEMENT OF THE AREA OF FGEN AND ASSOCIATED PRECIP SHIELD
TRANSLATING THROUGH THE LOCAL AREA BETWEEN AROUND 23-05Z /PERHAPS
WEAKENING SOMEWHAT/ WITH ANY ONE AREA SEEING AROUND 3-4 HOURS OF
PRECIP. QPF SHOULD BE GENERALLY LIGHT...AROUND .10-.15 INCHES.
PRECIP TYPE IS A BIT OF A CHALLENGE. TEMPERATURES THIS AFTERNOON
ARE IN THE UPPER 30S AND LOW 40S WITH DEWPOINTS STILL IN THE LOW/MID
20S OVER SE MI. RAP HAS A PRETTY GOOD HANDLE ON THIS WITH ASSOCIATED
WETBULB TEMPS 32-35F. NOT EXPECTING TEMPS TO DROP A WHOLE LOT IN
ADVANCE OF THE PRECIP WITH CLOUD COVER AND SOUTHERLY FLOW. DEWPOINTS
SHOULD EDGE UPWARD INTO THE UPPER 20S. WETBULB EFFECTS ONCE THE
PRECIP STARTS SHOULD DROP TEMPS INTO THE 33-37 DEGREE RANGE. WHILE
MUCH OF THE REGION COULD EXPERIENCE A MIX OF RAIN AND SNOW /WITH
SNOW MORE LIKELY IN THE AREAS OF EMBEDDED HEAVIER PRECIP/...HAVE
GONE WITH PREDOMINANTLY RAIN FOR METRO DETROIT AND SOUTH...MOSTLY
SNOW FOR THE SAGINAW VALLEY AND NORTHERN THUMB...AND A MIX
INBETWEEN. EXPECTING LOWS IN THE AREAS THAT EXPERIENCE SNOW TO
MAINLY REMAIN AOA FREEZING WITH LOW SNOW RATIOS SO ACCUMULATIONS ARE
NOT MUCH OF A CONCERN...WITH PERHAPS UP TO HALF AN INCH IN SPOTS
ALONG AND NORTH OF I-69.
ONCE THE UPPER MOISTURE STRIPS AWAY AFTER MIDNIGHT...THE SURFACE LOW
WILL TRANSLATE OVER THE REGION CAUSING WINDS TO BECOME LIGHT. LOW-
LEVEL MOISTURE WILL STILL BE AROUND. UPSTREAM OBS INDICATE
WIDESPREAD LOW CLOUDS WITH AREAS OF FOG AND DRIZZLE AND EXPECT THAT
WILL BE THE CASE OVER OUR AREA AS WELL. PATCHY AREAS OF FREEZING
DRIZZLE ARE POSSIBLE WHERE TEMPS GET CLOSER TO FREEZING...ESPECIALLY
OVER THE NORTHERN PARTS OF THE FORECAST AREA.
&&
.LONG TERM...TUESDAY THROUGH SUNDAY
THE EXTENDED FORECAST WILL START OFF WITH AN UPPER LEVEL TROUGH OVER
THE GREAT LAKES DRIFTING OFF TO THE MID ATLANTIC COAST AS IT BECOMES
A CLOSED MID LEVEL CIRCULATION. SE MI WILL BE UNDER THE UPPER LEVEL
COLD POOL AND BROAD LIFT FROM THE TROUGH DURING THE MID WEEK PERIOD
BEFORE LONGWAVE RIDGE BUILDING UP THROUGH THE CENTRAL CONUS TRIES TO
FORCE ITS WAY INTO THE REGION. A BLOCKING PATTERN LOOKS TO SET UP BY
THE END OF THE WEEK WITH THE INTERFACE BETWEEN THE RIDGE AND TROUGH
IN THE VICINITY OF EASTERN MI. THIS PRESENTS ONE OF THE MAIN
CHALLENGES IN THE LONG TERM AS THAT IS THE DIFFERENCE BETWEEN A MILD
SUNNY WEEKEND OR A CLOUDY WEEKEND WITH THE POSSIBILITY OF LIGHT
SNOWFALL.
WE START OFF TUESDAY WITH THE TROUGH AXIS OVER HEAD WHICH WILL
PRODUCE OVERCAST SKIES AND WINDS VEERING FROM SOUTHERLY TO NORTHERLY
THROUGH THE AFTERNOON. ADDITIONALLY...THE BROAD CYCLONIC FLOW AND
LIFT WITH A SATURATED COLUMN UP TO 8KFT WILL PRODUCE SOME LINGERING
SHOWERS THROUGH THE DAY AS THE FORCING PULLS OFF TO THE EAST. ONE
QUESTION REMAINS TO BE WHAT WILL THE PTYPE BE ON TUESDAY? THE TREND
WILL BE FOR THE COLUMN TO COOL AS THE -26C 500MB COLD POOL SLIDE
OVER THE AREA. 925MB TEMPS WILL BE CLOSE TO ZERO WITH 850MB TEMPS A
COUPLE DEGREES IN THE NEGATIVE. BUT THE SATURATION ONLY CLIMBS TO
AROUND 750MB OR SO WHICH MAY NOT QUITE BE ENOUGH FOR ALL ICE
CRYSTALS WITH TEMPS NEARING -9C. SO KEPT THE MENTION OF DRIZZLE
THROUGH THE FIRST HALF OF THE DAY POSSIBLY SWITCHING OVER TO ALL
SNOW CLOSER TO 00Z WEDNESDAY. TEMPERATURES ABOVE FREEZING UP TOWARD
950MB...ESPECIALLY ACROSS THE SOUTHERN HALF OF THE CWA SHOULD
PREVENT FREEZING DRIZZLE AS SFC TEMPS REACH INTO THE UPPER 30S.
THE NATURE OF THE PRECIP FORCING CHANGES OVERNIGHT TUESDAY INTO
WEDNESDAY AS THE DEEPER MOISTURE GETS PULLED EAST LEAVING A VERY
SHALLOW LAYER OF MOISTURE WITH NORTHERLY FLOW. THIS COLDER NORTHERLY
FLOW OFF LAKE HURON WILL LIKELY PRODUCE SOME LAKE EFFECT SNOW OVER
THE THUMB BUT MODELS DO NO INDICATE ANY STRONG CONVERGENT REGIONS
OVER THE LAKE AND DELTA T FROM THE SFC TO 850MB IS RATHER WEAK
AROUND 10C. WILL CONTINUE THE HIGHER POP...LOWER QPF FORECAST FOR
THE THUMB UNTIL WE SEE MORE DEFINITIVE SIGNATURES TO LOWER THE POPS
OR START THINKING IN TERMS OF POSSIBLE ACCUMULATIONS. TEMPERATURES
OVER LAND WEDNESDAY WILL HOLD AROUND THE FREEZING MARK AS THE
BACKSIDE OF THE COLD POOL ALOFT LINGERS OVER THE EASTERN GREAT
LAKES.
HIGH PRESSURE...AND DRY WEATHER...LOOKS TO REMAIN IN PLACE THROUGH
MUCH OF THE EXTENDED PERIOD. SOME RECENT MODEL RUNS INDICATE A
CHANCE OF SOME SNOW SHOWERS TRYING TO CREEP IN ON THURSDAY AS A LOW
PRESSURE SYSTEM DEVELOPS TO OUR EAST. CONFIDENCE IN THIS FEATURE AT
THIS TIME IS LOW AND HAVE ONLY INCLUDED A SLIGHT CHANCE OF SOME SNOW
FOR THE EXTREME EASTERN PORTION OF THE CWA /ST CLAIR SANILAC AND
EASTERN HURON COUNTIES/. OTHERWISE DRY CONDITIONS PREVAIL THROUGH
THE WEEKEND WITH THE NEXT DISTURBANCE ARRIVING LATE SUNDAY. CURRENT
MODEL GUIDANCE SHOWS TEMPERATURES WILL BE WARM ENOUGH FOR
PRECIPITATION WITH THIS SYSTEM TO BE ALL RAIN...HOWEVER...WOULD NOT
BE SURPRISED IF SOME SNOW MIXES IN ON SUNDAY NIGHT AS TEMPERATURES
BEGIN TO DROP. FOR NOW HAVE JUST LEFT THE PRECIPITATION AS ALL RAIN
BUT SNOW MAY HAVE TO BE ADDED LATER AS WE GET A BETTER SAMPLING OF
HOW THIS SYSTEM WILL PLAY OUT.
&&
.MARINE...
AN UPPER LEVEL TROUGH OF LOW PRESSURE AND ASSOCIATED WEAK SURFACE
REFLECTION WILL BRING UNSETTLED WEATHER TO THE GREAT LAKES FOR THE
NEXT COUPLE DAYS. SOUTHERLY FLOW AHEAD OF THE TROUGH IS BEGINNING TO
SETTLE ALLOWING US TO CANCEL THE SMALL CRAFT ADVISORY OVER SAGINAW
BAY A FEW HOURS EARLY BUT FLOW OVER LAKE HURON WILL WARRANT THE
CONTINUATION OF THE NEARSHORE SMALL CRAFTS THROUGH THE EVENING WITH
GUSTS AROUND 25 KNOTS AND ELEVATED WAVE HEIGHTS. THE TROUGH AXIS
WILL TRACK ACROSS THE AREA TUESDAY VEERING WINDS AROUND TO THE
NORTH. COLD AIR ADVECTION BEHIND A PASSING COLD FRONT OVER THE
SLIGHTLY WARMER WATERS...WITH A TIGHTENING PRESSURE GRADIENT BETWEEN
THE STALLING UPPER LEVEL TROUGH AND THE RIDGE TRYING TO BUILD IN
FROM THE WEST WILL HELP EXCITE THE WIND FIELD ONCE AGAIN. A MARGINAL
GALE WATCH CONTINUES FOR THE SOUTHERN LAKE HURON BASIN AS WINDS LOOK
TO GUST NEAR 35 KNOTS WITH THIS SETUP. THE UPPER LEVEL FEATURE MAY
TRY TO HEAD BACK WEST TOWARD THE AREA LATER IN THE WEEK WHICH WOULD
KEEP SOME SEMBLANCE OF THE INCREASED NORTHERLY FLOW THROUGH MID
WEEK.
&&
.AVIATION...ISSUED 106 PM EST MON DEC 8 2014
//DISCUSSION...
NORTH/SOUTH ORIENTED AREA OF PRECIP OVER NORTHERN/WESTERN LOWER MI
INTO NORTHWEST IN EDGING SLOWLY EASTWARD. SHARP MOISTURE GRADIENT
WILL ALLOW MID/HIGH CLOUDS TO DROP TO MVFR RATHER QUICKLY THIS
EVENING. THE FORCING WITH THIS SYSTEM IS EXPECTED TO WEAKEN A BIT
WITH EASTWARD EXTENT SO ONLY EXPECTING 3-4 HOURS OF LIGHT PRECIP
AT THE TERMINALS STARTING AROUND 23Z FOR MBS/FNT AND 00Z FOR PTK
SOUTHWARD. ENOUGH WARM AIR SHOULD BE AROUND TO KEEP PRECIP MOSTLY
RAIN FROM PTK SOUTHWARD. PRECIP TYPE SHOULD BE MOSTLY SNOW AT MBS
WITH BORDERLINE RAIN/SNOW EXPECTED FOR FNT.
WINDS WILL DIMINISH AS SURFACE LOW MOVES OVER THE AREA WITH
CONCERNS FOR IFR CIGS AND FOG DEVELOPING. VISIBILITY AOB 1 SM HAS
BEEN WIDESPREAD UPSTREAM OVER WI SO SOME DENSE FOG/DRIZZLE WILL
BE POSSIBLE. OMITTED LIFR FOR THIS ISSUANCE BUT POTENTIAL WILL BE
ADDRESSED AS THINGS DEVELOP. IMPROVING VIS WILL OCCUR AFTER 12Z
TUE AS NNW WINDS INCREASE.
FOR DTW...LIGHT RAIN SHOWERS ARE POSSIBLE 00-04Z. MID CLOUDS
WILL LOWER TO MVFR FROM 23-01Z. IFR CIGS AND FOG WILL BECOME
LIKELY AFTER 04Z WITH PERIODS OF DENSE FOG /LIFR/ POSSIBLE THROUGH
14Z.
//DTW THRESHOLD THREATS...
* HIGH CONFIDENCE IN CEILING BELOW 5000 FEET AFTER 00Z TONIGHT.
* HIGH CONFIDENCE IN RAIN AS PRECIPITATION TYPE
* MEDIUM CONFIDENCE IN VISIBILITY DROPPING BELOW 1/2 SM AND/OR
CIGS BELOW 200 FT.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...GALE WATCH FROM TUESDAY EVENING THROUGH WEDNESDAY MORNING FOR
LHZ441>443-462>464.
SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR LHZ441>443.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
SHORT TERM...DT
LONG TERM....DRK/RK
MARINE.......DRK
AVIATION.....DT
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
305 PM EST MON DEC 8 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 304 PM EST MON DEC 8 2014
LATEST WATER VAPOR IMAGERY AND RUC ANALYSIS THE SHOW SHORTWAVE TROF
MOVING ACROSS THE UPPER GREAT LAKES THIS AFTERNOON. MODELS INDICATE
BEST ISENTROPIC ASCENT...MOISTURE TRANSPORT AND DEEP LAYER Q-VECT
CONVERGENCE HAS SHIFTED EAST WITH MAIN SNOW BAND AHEAD OF THE SFC-8H
TROF OVER CENTRAL UPPER MI. IT/S POSSIBLE THERE MAY BE SOME PATCHY
-FZDZ LATE THIS AFTERNOON BEHIND THE SNOW BAND WITH MID-LVL DRYING
AND LOW-LVL MOISTURE TOO SHALLOW TO REACH THE -10C ISOTHERM...BUT
NOT SURE IF THE FZDZ WILL BE SIGNIFICANT ENOUGH TO INCLUDE IN FCST
GRIDS THIS EVENING.
MODELS INDICATE THAT N TO NW WINDS WILL STRENGTHEN TONIGHT BEHIND
DEPARTING LOW PRES TONIGHT. COOLING LOW-LEVEL AIR MASS MAY SUPPORT
SOME LAKE ENHANCED SNOW FOR A BRIEF TIME THIS EVENING.
HOWEVER...SNOWFALL IS EXPECTED TO BE LIGHT FOR THE FOLLOWING
REASONS...850MB TEMPS (AROUND -6C) ARE MARGINAL FOR ENHANCEMENT
WHILE DEEPER MOISTURE IS AROUND...LOW-LEVEL FLOW IS NOT STRONGLY
CYCLONIC...AND DGZ IS ABOVE THE UPWARD MOTION AND THE DEEPER
MOISTURE. UPSLOPE/OROGRAPHIC MOTION MAY BE THE DRIVING COMPONENT
AIDING SNOWFALL...AND WHERE THAT IS MAXIMIZED...EXPECT GENERALLY 1-2
INCHES OF SNOW TONIGHT OVER HIGHER TERRAIN NEAR LAKE SUPERIOR.
INCREASED SUBSIDENCE AND LOWERING OF INVERSION HGTS AHEAD OF THE
BUILDING MID-LVL RDG UPSTREAM MAY ALSO CONTRIBUTE TO A BRIEF PD OF
UPSLOPE FZDZ LATE TONIGHT OVER THE NRN TIER COUNTIES IN NRLY FLOW
LATE TONIGHT...BUT NAM SNDGS SHOW THE SHALLOW MOIST LAYER COOLING TO
-10C BY SUNRISE WHICH SHOULD AGAIN SUPPORT MAINLY LIGHT
SNOW/FLURRIES. SINCE FZDZ THREAT IS UNCERTAIN AND LOOKS TO BE BRIEF
IF IT DOES OCCUR WL LEAVE IT OUT OF GRIDS FOR NOW. LOOK FOR MIN
TEMPS RANGING FROM THE LOWER 20S INTERIOR WEST TO UPPER 20S EAST
HALF.
1034 MB SFC RIDGE BUILDING IN FROM THE WEST SHOULD WEAKEN THE PRES
GRADIENT AND THUS ALLOW NRLY WINDS TO DIMINISH ACROSS THE AREA BY
AFTERNOON. CONTINUED LOWERING OF INVERSION BASES BLO 3KFT WILL
QUICKLY DIMINISH ANY REMAINING LIGHT UPSLOPE SHSN TO FLURRIES BY
LATE MORNING. LOOK FOR HIGHS RANGING FROM THE LOWER TO MID 20S WEST
TO LOWER 30S EAST HALF.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 340 AM EST MON DEC 8 2014
SHARP UPPER TROUGH WILL BE E OF THE CWA BY 12Z TUE AS A 1034MB SFC
RIDGE IS JUST W OF THE CWA. WINDS WILL START THE DAY TUE OUT OF THE
N WITH 850MB TEMPS AROUND -8C...WHICH IS NOT COLD ENOUGH FOR PURE
LES. HAVE QUICKLY DIMINISHING POPS ON TUE AS UPSLOPE PRECIP WILL
DIMINISH AS THE SFC RIDGE MOVES IN. DO NOT EXPECT MORE THAT A HALF
INCH OF ADDITIONAL SNOW ON TUE.
TUE NIGHT THROUGH SAT WILL SEE AN UPPER RIDGE BUILDING INTO THE
REGION...WHICH WILL LEAD TO MOSTLY DRY AND WARMER TEMPERATURES.
SHOULD STILL SEE COLD NIGHTS TUE NIGHT AND WED NIGHT AS LOWS
APPROACH 0F...ESPECIALLY WED NIGHT. HIGH TEMPS WILL BE WARMEST FRI
AND SAT /ESPECIALLY SAT/ AND WILL BE IN THE LOW 40S IN PLACES BOTH
DAYS. MODELS HAVE BEEN HINTING AT A SHORTWAVE MOVING INTO THE REGION
ON SAT. WHILE THIS IS NOT CERTAIN BY ANY MEANS...DID SHOW A SUBTLE
INCREASE IN POPS ON SUN. ALSO...KEPT FOG IN THE FORECAST FOR SAT
NIGHT AND SUN AS HIGHER DEW POINTS SPREAD INTO THE AREA OVER A
SLOWLY MELTING SNOW PACK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1252 PM EST MON DEC 8 2014
LOW LEVEL MOISTURE ACCOMPANYING A LOW PRES SYSTEM MOVING THROUGH THE
AREA WILL RESULT IN IFR CIGS AND SCT -SHSN THIS AFTERNOON. IFR
CONDITIONS SHOULD PERSIST TONIGHT WITH SNOW PICKING UP FOR A TIME
UNDER STRENGTHENING UPSLOPE NNW-N WINDS. THERE MAY BE SOME
IMPROVEMENT AT KCMX LATE TONIGHT AS UPSLOPING DIMINISHES AND SOME
MINOR DIURNAL IMPROVEMENT AT KIWD AND KSAW TUE MORNING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 304 PM EST MON DEC 8 2014
BEHIND THE LOW...N TO NW WINDS RAMP UP TONIGHT...AIDED BY PRES RISES
APPROACHING FROM THE NW. MAGNITUDE OF PRES RISES SUGGESTS POTENTIAL
FOR A FEW HRS WHEN WINDS MAY GUST TO NEAR 35KT FROM NCNTRL TO SCNTRL
LAKE SUPERIOR. WINDS WILL DIMINISH FROM W TO E TUE AS HIGH PRES
RIDGE APPROACHES. WITH THE HIGH PRES RIDGE ARRIVING OVER THE UPPER
LAKES TUE NIGHT/WED...LIGHTER WINDS UNDER 20KT ARE EXPECTED... AND
THESE LIGHTER WINDS SHOULD LINGER ON THRU THU AND POSSIBLY FRI AS
WELL.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...TITUS
AVIATION...VOSS
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1259 PM EST MON DEC 8 2014
.UPDATE...
ISSUED AT 1025 AM EST MON DEC 8 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW SHORTWAVE TROF MOVING INTO
THE WESTERN GREAT LAKES. RIBBON OF 850-700MB MOISTURE TRANSPORT IN
CONCERT WITH ISENTROPIC ASCENT ENHANCED BY 850MB WINDS OF 40-45KT
AND DEEP LAYER QVECTOR CONVERGENCE AHEAD OF TROF IS SUPPORTING A
BAND OF MODERATE TO HEAVY SNOW OVER THE EASTERN 4 COUNTIES OF THE
CWA. THE BAND IS MOVING ALONG FAIRLY RAPIDLY FROM WEST TO EAST
DRIVEN BY 40 KT WSW WINDS AT MID-LVLS AHEAD OF THE SHORTWAVE TROUGH
SO EXPECT PERIOD OF MODERATE TO HEAVY SNOW TO LAST LESS THAN AN HOUR
OVER MOST LOCATIONS. BUT AS THE SNOW BAND MOVES THROUGH IT COULD
DROP A QUICK 1-2 INCHES OF SNOW. AS A RESULT OF THIS HEAVIER SNOW
BAND DECIDED TO ISSUE STORM TERM WINTER WX ADVISORIES FOR THE 4 ERN
COUNTIES TO HIGHLIGHT THE BRIEF INTENSITY OF THE SNOW AND
SNOW-COVERED AND SLIPPERY ROADS INTO EARLY AFTERNOON. SNOW WILL
TAPER OFF QUICKLY TO FLURRIES BEHIND THIS MAIN BAND AS BEST MOISTURE
AND ISENTROPIC ASCENT SHIFTS EAST.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 534 AM EST MON DEC 8 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW SHORTWAVE TROF MOVING INTO
THE WESTERN GREAT LAKES. RIBBON OF 850-700MB MOISTURE TRANSPORT IN
CONCERT WITH ISENTROPIC ASCENT ENHANCED BY 850MB WINDS OF 40-45KT
AND DEEP LAYER QVECTOR CONVERGENCE AHEAD OF TROF IS SUPPORTING A
BAND OF SNOW THAT IS SHIFTING E ACROSS THE FCST AREA. AS OF 10Z...
BAND OF SNOW RUNS FROM MENOMINEE TO ESCANABA TO MUNISING. TO THE W
SNOW DIMINISHES...AND THERE MAY BE SOME PATCHY -FZDZ AS WELL THOUGH
WITH SNOW ALREADY ON THE ROADS...ANY -FZDZ SHOULDN`T CONTRIBUTE TO
MAKING ROADS ANY MORE SLIPPERY THAN THEY ALREADY ARE. CLOSE TO
APPROACHING VORT MAX...ANOTHER AREA OF SNOW IS SPREADING ACROSS NW
WI/WRN LAKE SUPERIOR INTO FAR WRN UPPER MI.
BAND OF HEAVIER SNOW CURRENTLY PUSHING INTO THE ERN FCST AREA WILL
CONTINUE TO SHIFT E IN CONCERT WITH TRANSLATING RIBBON OF MOISTURE
TRANSPORT/ISENTROPIC ASCENT. THIS BAND OF SNOW WILL LIKELY SHIFT OUT
OF THE FCST AREA LATE MORNING/EARLY AFTN...AND SNOW ACCUMULATIONS
WILL BE MOSTLY ON THE ORDER 1.5-2.5 INCHES. OTHERWISE...EXPECT AREAS
OF -SN TODAY (ACCUMULATIONS MOSTLY 1 INCH OR LESS) AS TROF MOVES
INTO THE UPPER LAKES. HOWEVER...SNOW WILL LIKELY BE MORE WIDESPREAD
DURING THE MORNING HRS IN ASSOCIATION WITH VORT MAX MOVING ACROSS
WRN UPPER MI. ALTHOUGH IT`S A MILD START TO THE DAY...CLOUDS WILL
KEEP TEMPS FROM RISING MUCH. HIGH WILL BE IN THE LOW TO MID 30S.
N TO NW WINDS STRENGTHEN BEHIND DEPARTING LOW PRES TONIGHT. COOLING
LOW-LEVEL AIR MASS WILL SUPPORT SOME LAKE ENHANCEMENT FOR A TIME.
HOWEVER...SNOWFALL IS ONLY EXPECTED TO BE LIGHT FOR SEVERAL REASONS.
850MB TEMPS ARE MARGINAL FOR ENHANCEMENT WHILE DEEPER MOISTURE IS
AROUND...LOW-LEVEL FLOW IS NOT STRONGLY CYCLONIC...AND DGZ IS ABOVE
THE UPWARD MOTION AND MOST OF THE DEEPER MOISTURE FOR THAT MATTER.
UPSLOPING WILL BE A MAIN COMPONENT AIDING SNOWFALL...AND WHERE THAT
IS MAXIMIZED...EXPECT 1-2 INCHES OF SNOW TONIGHT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 340 AM EST MON DEC 8 2014
SHARP UPPER TROUGH WILL BE E OF THE CWA BY 12Z TUE AS A 1034MB SFC
RIDGE IS JUST W OF THE CWA. WINDS WILL START THE DAY TUE OUT OF THE
N WITH 850MB TEMPS AROUND -8C...WHICH IS NOT COLD ENOUGH FOR PURE
LES. HAVE QUICKLY DIMINISHING POPS ON TUE AS UPSLOPE PRECIP WILL
DIMINISH AS THE SFC RIDGE MOVES IN. DO NOT EXPECT MORE THAT A HALF
INCH OF ADDITIONAL SNOW ON TUE.
TUE NIGHT THROUGH SAT WILL SEE AN UPPER RIDGE BUILDING INTO THE
REGION...WHICH WILL LEAD TO MOSTLY DRY AND WARMER TEMPERATURES.
SHOULD STILL SEE COLD NIGHTS TUE NIGHT AND WED NIGHT AS LOWS
APPROACH 0F...ESPECIALLY WED NIGHT. HIGH TEMPS WILL BE WARMEST FRI
AND SAT /ESPECIALLY SAT/ AND WILL BE IN THE LOW 40S IN PLACES BOTH
DAYS. MODELS HAVE BEEN HINTING AT A SHORTWAVE MOVING INTO THE REGION
ON SAT. WHILE THIS IS NOT CERTAIN BY ANY MEANS...DID SHOW A SUBTLE
INCREASE IN POPS ON SUN. ALSO...KEPT FOG IN THE FORECAST FOR SAT
NIGHT AND SUN AS HIGHER DEW POINTS SPREAD INTO THE AREA OVER A
SLOWLY MELTING SNOW PACK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1252 PM EST MON DEC 8 2014
LOW LEVEL MOISTURE ACCOMPANYING A LOW PRES SYSTEM MOVING THROUGH THE
AREA WILL RESULT IN IFR CIGS AND SCT -SHSN THIS AFTERNOON. IFR
CONDITIONS SHOULD PERSIST TONIGHT WITH SNOW PICKING UP FOR A TIME
UNDER STRENGTHENING UPSLOPE NNW-N WINDS. THERE MAY BE SOME
IMPROVEMENT AT KCMX LATE TONIGHT AS UPSLOPING DIMINISHES AND SOME
MINOR DIURNAL IMPROVEMENT AT KIWD AND KSAW TUE MORNING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 534 AM EST MON DEC 8 2014
PRES GRADIENT WILL WEAKEN TODAY AS LOW PRES OVER FAR SE MANITOBA
MOVES E...PASSING ACROSS NORTHERN AND EASTERN LAKE SUPERIOR LATE
THIS AFTN AND EVENING. AS A RESULT...WINDS WILL DIMINISH ACROSS LAKE
SUPERIOR TODAY WITH GALES OVER THE ERN LAKE ENDING BY MID MORNING.
BEHIND THE LOW...N TO NW WINDS WILL RAMP UP TONIGHT...AIDED BY PRES
RISES APPROACHING FROM THE NW. MAGNITUDE OF PRES RISES SUGGESTS
POTENTIAL FOR A FEW HRS WHEN WINDS MAY GUST TO NEAR 35KT FROM NCNTRL
TO SCNTRL LAKE SUPERIOR. WINDS WILL DIMINISH FROM W TO E TUE AS HIGH
PRES RIDGE APPROACHES. WITH THE HIGH PRES RIDGE ARRIVING OVER THE
UPPER LAKES TUE NIGHT/WED...LIGHTER WINDS UNDER 20KT ARE EXPECTED...
AND THESE LIGHTER WINDS SHOULD LINGER ON THRU THU AND POSSIBLY FRI
AS WELL.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR MIZ007.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...VOSS
SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...VOSS
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1205 PM CST MON DEC 8 2014
.UPDATE...FOR 18Z AVIATION DISCUSSION BELOW
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 329 AM CST MON DEC 8 2014
CURRENT CONDITIONS SYNOPSIS...
LATEST SURFACE ANALYSIS SHOWS LOW PRESSURE NORTHWEST OF
INTERNATIONAL FALLS... WITH A COLD FRONT TRAILING SOUTH THROUGH
SOUTHWEST MINNESOTA. WATER VAPOR IMAGERY AND RAP UPPER AIR ANALYSIS
SHOW AN INITIAL SHORTWAVE PUSHING THROUGH EASTERN MINNESOTA AT THE
CURRENT TIME... WITH A SECONDARY WAVE DROPPING INTO EASTERN NORTH
DAKOTA. THIS SECOND WAVE WILL HELP PUSH THE AFOREMENTIONED SURFACE
LOW AND FRONTAL BOUNDARY EAST ACROSS THE AREA THIS MORNING... WITH
THE FRONT QUICKLY WORKING THROUGH WISCONSIN BY AFTERNOON. EXTENSIVE
LOW CLOUDS WERE PRESENT ACROSS THE STATE... WITH LAYERED CLOUDS
ASSOCIATED WITH THE UPPER WAVE HELPING TO PRODUCE SOMEWHAT MORE
MEANINGFUL RETURNS ON RADAR NORTH OF I-94 WHERE SOME LIGHT
ACCUMULATING SNOW HAS OCCURRED. LOW CLOUDS EXTEND WELL UPSTREAM
THROUGH NORTH DAKOTA AND INTO MANITOBA AND SASKATCHEWAN.
FORECAST ITEM/S/ OF CONCERN...
LINGERING LIGHT PCPN IS THE PRIMARY FORECAST CONCERN. SOME MIXED
PCPN CONTINUES ACROSS THE AREA GIVEN THE LACK OF SATURATION AND
PRESENCE OF ONLY LIQUID WATER WITHIN CLOUDS OVER MUCH OF THE CENTRAL
AND SOUTHERN PORTION OF THE AREA. THIS IS RESULTING IN SOME
MIST/DRIZZLE... WHICH IS LEADING TO SOME LIGHT ICING IN LOCATIONS
WHERE TEMPERATURES ARE BELOW FREEZING OR WHERE UNTREATED GROUND
TEMPERATURES ARE SUB-FREEZING. THE DEEPER MOISTURE AND LAYERED
CLOUDS OVER THE NORTHERN PART OF THE AREA ARE HELPING TO SEED THINGS
WITH ICE CRYSTALS AND ALLOWING FOR MORE IN THE WAY OF LIGHT SNOWFALL
ACROSS THE NORTHERN PART OF THE AREA. HOWEVER... THE BEST FORCING
ASSOCIATED WITH THE UPPER WAVE CONTINUES TO PUSH EAST... SO ANY
LINGERING PCPN TODAY WILL MAINLY BE DRIVEN BY LOW LEVEL CYCLONIC
FLOW AND A FAIRLY SHALLOW DEPTH OF LIFT. PCPN TYPE COULD REMAIN AN
ISSUE... ALTHOUGH THE NAM AND GFS SUGGEST WE SHOULD HAVE JUST ENOUGH
DEPTH OF MOISTURE THROUGH THE DAY FOR ANY PCPN TO BE MAINLY SNOW
GIVEN THE COLDER TEMPERATURES MOVING IN ALOFT. LOOKING UPSTREAM
THERE IS MINIMAL PCPN BEING REPORTED IN THE STRATOCU AREA... WITH
PCPN MAINLY BENEATH THE UPPER COLD POOL.
MODEL DISCUSSION/PREFERENCES...
DO NOT HAVE A STRONG PREFERENCE FOR ANY PARTICULAR SOLUTION IN THE
SHORT TERM... SO STUCK WITH A COMPROMISE OF HRRR... NAM... RAP...
AND HOPWRF SOLUTIONS. THESE ALL POINT TOWARD MAINLY CLOUDY SKIES
TODAY AND TONIGHT... WITH DRIER AIR TRYING TO WORK IN TOWARD THE END
OF THAT PERIOD TO SCOUR OUT THE LOWER CLOUDS.
SENSIBLE WEATHER EXPECTATIONS...
THE BULK OF THE PCPN SHOULD CONTINUE TO SHIFT EAST TODAY AS THE
INITIAL SHORTWAVE EXITS AND THE SECONDARY WAVE QUICKLY ROTATES
THROUGH THE AREA. HOWEVER... CYCLONIC BOUNDARY LAYER FLOW AND THE
PRESENCE OF THE UPPER TROUGH SHOULD KEEP SOME CHANCE OF PCPN GOING
FOR MUCH OF THE DAY OVER THE NORTHERN AND EASTERN PORTION OF THE
AREA. CAN/T RULE OUT SOME ADDITIONAL LIGHT MIXED PCPN... ALTHOUGH
THE GENERAL TENDENCY SHOULD BE FOR MORE IN THE WAY OF SNOWFLAKES
THAN ANYTHING ELSE WHERE PCPN OCCURS.
DETAILED DISCUSSION FOR ITEM/S/ OF CONCERN...
VERTICAL PROFILES WILL DETERMINE PCPN TYPE THROUGH THE DAY TODAY...
AND FORECAST SOUNDINGS SUGGEST SOME CHANCE FOR FZDZ OR LIGHT
FREEZING RAIN AT TIMES WITH DRIER AIR IN THE MID-LEVELS AND A LOSS
OF ICE CRYSTALS. HOWEVER... PCPN WILL CONTINUE TO BE ON THE
DOWNSWING... SO ANY ADDITIONAL ACTIVITY SHOULD BE LIMITED IN ITS
OCCURRENCE. HIGH PRESSURE WILL BUILD IN FROM THE NORTHWEST
TONIGHT... WORKING TO BRING ANY LINGERING PCPN TO AN END AS
SUBSIDENCE FINALLY WORKS TO SCOUR OUT THE CLOUD COVER FROM WEST TO
EAST.
FORECAST CONFIDENCE/UNCERTAINTY...
CONFIDENCE IS MODERATE TO HIGH IN THE PRESENCE OF CLOUDY SKIES TODAY
INTO THIS EVENING... WITH LOW TO MODERATE CONFIDENCE THAT CLOUDS
WILL BREAK UP LATER TONIGHT. THERE IS MODERATE TO HIGH CONFIDENCE
THAT LIGHT PCPN WILL CONTINUE TO IMPACT THE NORTHEAST AND EASTERN
PORTION OF THE AREA INTO THIS AFTERNOON... WITH CONFIDENCE OF PCPN
OCCURRENCE DECREASING TO THE SOUTH AND WEST. THERE IS LOW CONFIDENCE
IN THE EXACT TIMING AND LOCATION OF ADDITIONAL MIXED PCPN IN THE
FORM OF FREEZING DRIZZLE.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 329 AM CST MON DEC 8 2014
BIGGEST QUESTION DURING THE LONG TERM STILL REVOLVES AROUND HOW WARM
CAN WE GET FRIDAY AND SATURDAY...WHICH REALLY MEANS THAT QUESTION IS
HOW MUCH STRATUS DO WE SEE THEN. NO MAJOR PRECIP MAKERS LOOK TO
IMPACT THE AREA...WITH ONLY SOME LIGHT RAIN EXPECTED WITH A COLD
FRONT PASSING THROUGH THE AREA FOR THE SECOND HALF OF THE WEEKEND.
MEDIUM RANGE MODELS CONTINUE TO SHOW A SIGNIFICANT PATTERN SHIFT
COMMENCING THIS WEEK...AS THE DEEP UPPER LOWS AND ASSOCIATED ARCTIC
AIRMASSES SHIFT TO THE EAST BY ABOUT 60 DEGS OF LONGITUDE. THIS WILL
PUSH THE ARCTIC OFF INTO THE NORTH ATLANTIC AND EASTERN ASIA...WITH
MUCH OF THE NORTH AMERICAN LAND MASS REMAINING ARCTIC AIRMASS
FREE...WITH ABOUT THE ONLY COLD AIR OVER THE CONUS BY THE WEEKEND
BEING FOUND UNDER THE UPPER LOW THAT WILL BE CLOSING OFF OVER THE
EAST COAST BY THE END OF THE WEEK.
THE LONG TERM WILL START WITH A MOISTURE STARVED UPPER LOW WORKING
FROM NODAK INTO CENTRAL IOWA TUESDAY INTO TUESDAY NIGHT. AT THE
SFC... A BETTER THAN 1032MB SW-NE ORIENTED RIDGE WILL BE WORKING
ACROSS THE UPPER MS VALLEY...HENCE WHY THE UPPER WAVE IS MOISTURE
STARVED IN THE LOW LEVELS. TUESDAY WILL BE THE COLDEST DAY OF THE
WEEK BY FAR...WITH TEMPERATURES REMAINING IN THE 20S...BUT TUESDAY
NIGHT...WE GET ON THE BACKSIDE OF THE HIGH...WITH SRLY FLOW SETTING
UP FROM WEDNESDAY INTO SUNDAY. AS THESE SRLY WINDS BLOW...AN
IMPRESSIVE H5 RIDGE WILL BE BUILDING INTO THE UPPER MS VALLEY. BY
SATURDAY ALL MED RANGE MODELS SHOW H5 HEIGHTS EXCEEDING 570
DM...WHICH WOULD BE SOME OF THE HIGHEST H5 HEIGHTS EVER OBSERVED IN
THE MONTH OF DECEMBER IN THE COMBINED STC/MPX SOUNDING
HISTORY...WHICH DATES BACK TO 1948. TO GO WITH THAT...THE ECMWF
CONTINUES TO SHOW H85 TEMPS FRIDAY/SATURDAY BUILDING TO BETWEEN +12C
AND +16C. LIKE THE H5 HEIGHTS...H85 TEMPS THIS HIGH ARE BASICALLY AT
THE OBSERVED MAX IN DECEMBER FOR STC/MPX.
TO GO ALONG WITH THESE IMPRESSIVE H5 HEIGHTS AND H85 TEMPS...WE WILL
BE SEEING OUR DEWP TEMPS SURGE INTO AT LEAST THE 40S...WITH THE
ECMWF ACTUALLY BRINGING 50 DEGREE DEWPS ALL THE WAY UP TO I-94 ON
SATURDAY. EVEN IF WE ONLY SEE DEWPS IN THE MID 40S...THAT WOULD BE
ABOUT 15 DEGREES HIGHER THAN THE NORMAL HIGH. THE MAJORITY OF THE
TIME WHEN DEWPS IN THE WINTER EXCEED THE NORMAL HIGHS BY THAT MUCH
IT MEANS A DAY FULL OF FOG AND STRATUS...AND THAT CERTAINLY LOOKS TO
BE THE CASE ON SATURDAY. FRIDAY MAY AVOID THE STRATUS AND GO ABOUT
MOSTLY SUNNY...BUT SATURDAY NIGHT...WHEN THE 40+ DEWPS GET
HERE...THEY LOOK TO COME WITH PLENTY OF LOW STRATUS. WHAT DOES ALL
THAT MEAN...WELL IT WILL PROBABLY BE TOUGH TO REACH RECORD HIGH MAX
TEMPS /51 TO 53/...BUT WE SHOULD HAVE NO PROBABLY SETTING SOME NEW
RECORD WARM MINIMUMS OVER THE WEEKEND. SUNDAY...A COLD FRONT WILL
WORK ACROSS THE MPX AREA...BUT LOOKS TO COME THROUGH LATE ENOUGH TO
GIVE ALL BE WRN MN ONE MORE DAY WITH HIGHS IN THE 40S BEFORE
TEMPERATURES COOL BACK CLOSER TO NORMAL.
FOR PRECIP...THE ATMO LOOKS TO REMAIN TOO DRY FOR ANYTHING UNTIL THE
COLD FROM STARTS MOVING INTO WRN MN SATURDAY NIGHT. MOISTURE
TRANSPORT AND ISENTROPIC ASCENT AHEAD OF THE FRONT LOOK TO BE ENOUGH
TO GENERATE SOME LIGHT PRECIP. GFS FORECAST SOUNDINGS WOULD SAY WE
LACK ICE CRYSTALS...WITH PRIMARY TYPE BE DZ THROUGH THE
WEEKEND...THOUGH WITH TEMPERATURES AS WARM AS THEY ARE FORECAST TO
BE...P-TYPE LIKELY WILL NOT BE MUCH OF AN ISSUE...IT WILL BE ALL
DZ/RA UNTIL AFTER THE COLD FRONT PASSES.
ALTHOUGH IT DOES COOL DOWN BEHIND THE FRONT...BOTH THE GFS/ECMWF ARE
IN GOOD AGREEMENT WITH THE DOOR TO THE ARCTIC REMAINING FIRMLY SHUT
FOR US FOR THE NEXT 10 DAYS...WITH THE FIRST HALF OF DECEMBER
LOOKING TO START OFF ON A VERY MILD NOTE AFTER A VERY COLD DAY 1.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1215 PM CST MON DEC 8 2014
A FEW AREAS OF DRIZZLE/SNOW WILL PERSIST OVER WEST CENTRAL WI THIS
AFTERNOON...BUT OTHERWISE THE PRIMARY THREAT WILL BE THE
PERSISTENCE OF MVFR/IFR CIGS AREA-WIDE. THE MAIN CHANGE WITH THE 18Z
ISSUANCE WAS TO PROLONG THE LOW CLOUD COVER...AS IT LOOKS AS IF
MOST SITES WILL STAY SOCKED IN THROUGH TUESDAY MORNING. LOW-END
MVFR CIGS /CIRCA 1500-2000FT/ SHOULD BECOME PREVALENT THIS
AFTERNOON...BUT THEY WILL DEGRADE BACK BELOW 1000FT OVERNIGHT.
WESTERN SITES /KAXN AND KRWF/ MAY SCATTER OUT TONIGHT...BUT THEN
EXPECT REDEVELOPMENT OF FOG/STRATUS OVERNIGHT. GUSTY NORTHWEST WINDS
BECOME LIGHT TONIGHT...THEN VEER TO NORTHEASTERLY AROUND OR UNDER
5 KTS FOR TUESDAY.
KMSP...
CIGS EXPECTED TO REMAIN BELOW 1700 FT THROUGH TONIGHT...WITH
SCATTERING AND VFR CIGS NOT ARRIVING UNTIL AFTER DAYBREAK TUESDAY.
THERE IS A SLIM POSSIBILITY CIG HEIGHTS COULD BRIEFLY IMPROVE TO
1900 FT THIS AFTERNOON...BUT ODDS ARE LOW AND IT WOULD BE SHORT-
LIVED. GUSTY NORTHWEST WINDS DECREASE TO AROUND 9-12KTS FOR
TONIGHT...THEN VEER TO THE NORTHEAST FOR TUESDAY WITH SPEEDS
AROUND 5-6KTS.
/OUTLOOK FOR KMSP/
TUESDAY EVENING THROUGH WEDNESDAY NIGHT...VFR. SOUTHEAST WIND LESS THAN
10 KT BECOMING SOUTH WEDNESDAY.
THURSDAY THROUGH FRIDAY...MVFR OR IFR CEILINGS POSSIBLE. SOUTH TO
SOUTHWEST WIND 5 TO 15 KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...TRH
LONG TERM...MPG
AVIATION...LS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
321 PM CST MON DEC 8 2014
.SHORT TERM...(TONIGHT THROUGH THURSDAY)
ISSUED AT 320 PM CST MON DEC 8 2014
THE PRIMARY FORECAST CONCERNS FOR TONIGHT AND TUESDAY ARE CLOUD
COVER AND RESULTING TEMPERATURES. ATTENTION TURNS MORE TOWARD THE
POTENTIAL FOR LOW CLOUDS/FOG/DRIZZLE WEDNESDAY INTO THURSDAY.
LARGE SCALE 500 MB PATTERN AT 12Z HAD THE FOLLOWING MAIN FEATURES.
A TROUGH WAS LOCATED TO OUR EAST/NORTHEAST...A RIDGE STRETCHED
FROM THE SOUTHERN ROCKIES INTO ALASKA AND A BROAD TROUGH WAS OUT
OVER THE PACIFIC. A CLOSED LOW SHOULD DEVELOP OUT OF THE TROUGH TO
OUR EAST IN THE EAST CENTRAL PART OF THE UNITED STATES BY TUESDAY
NIGHT. THAT FEATURE WILL THEN LIKELY WOBBLE INTO THE NORTHEAST
STATES INTO SATURDAY. IN OUR AREA...GENERAL RIDGING OCCURS IN THE
MID LEVELS BUT THERE WILL BE SOME SHORTWAVE ENERGY TRACKING EAST
THROUGH THE MEAN RIDGE...MAKING THE PATTERN A BIT MESSY. THE TROUGH
IN THE PACIFIC WILL BE PROGRESSIVE..AND BRING VERY WET WEATHER TO
MUCH OF THE WEST COAST THIS WEEK.
TONIGHT...CLOUD COVER IS PROBLEMATIC. LOW CLOUDS CURRENTLY IN A BAND
FROM NORTHERN IOWA ACROSS PARTS OF SOUTH DAKOTA AND INTO WESTERN
NORTH DAKOTA. THESE MAY TRY TO SINK SOUTHWARD INTO OUR AREA. THE MOST
RECENT RAP AND HRRR MODEL RUNS TEND TO DISSIPATE THIS
CLOUDINESS...BUT 12Z HIGH RESOLUTION NAM AND GFS DID BRING THE LOW
LEVEL MOISTURE SOUTHWARD. EVENING SHIFT WILL NEED TO MONITOR. A
COLD FRONT WAS ALREADY TRACKING SOUTHWARD INTO NORTHEAST NEBRASKA
AS OF EARLY THIS AFTERNOON AND WILL CONTINUE TO PUSH SOUTHWARD
THIS EVENING. COLD HIGH PRESSURE SHOULD BUILD IN BEHIND THE FRONT
FOR TONIGHT. WE EXPECT LOWS TO RANGE FROM THE UPPER TEENS NORTH TO
THE LOWER 20S SOUTH.
TUESDAY SHOULD BE COLDER THAN TODAY...WITH ONLY POOR TO FAIR MIXING.
NORTHEAST WINDS EARLY TURNING TO THE EAST OR SOUTHEAST DURING THE
DAY...AND HIGHS SHOULD TOP OUT MAINLY IN THE 30S. AS LOW LEVEL
SOUTHERLY FLOW STRENGTHENS...WE WILL HAVE TO MONITOR FOR DEVELOPMENT
OF LOW CLOUDS AND POSSIBLE DRIZZLE. THE BEST CHANCE FOR LIGHT RAIN
STAYS TO OUR SOUTH IN KANSAS FOR WEDNESDAY/WEDNESDAY NIGHT...BUT
AFTER COORDINATION WITH BORDERING OFFICES...ADDED SOME DRIZZLE INTO
OUR SOUTHERN COUNTIES FOR WEDNESDAY. THIS COULD BE FREEZING DRIZZLE
EARLY WEDNESDAY UNTIL TEMPERATURES RISE ABOVE 32 F. KEPT SOME
MENTION OF DRIZZLE INTO WEDNESDAY NIGHT. BEST LIFT MOVES INTO
SOUTHERN IOWA/NORTHERN MISSOURI FOR THURSDAY SO DID NOT INCLUDE
MENTION OF DRIZZLE IN THAT PERIOD. HIGHS THURSDAY SHOULD REACH
INTO THE 40S...POSSIBLY WARMER IF CLOUD COVER IS LESS THAN EXPECTED.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 320 PM CST MON DEC 8 2014
PATTERN IS A BIT MORE ACTIVE IN THIS PERIOD. 500 MB RIDGE WILL BE IN
PLACE FROM NEW MEXICO ACROSS OUR AREA AND INTO ONTARIO AT 12Z FRIDAY
...WITH MODELS IN GOOD AGREEMENT WITH STRENGTH AND LOCATION OF A
STRONG TROUGH ALONG THE WEST COAST. THE PATTERN OF LOW CLOUDS AND
DRIZZLE MAY CONTINUE INTO FRIDAY. WENT SOMEWHAT CONSERVATIVE FOR
HIGHS FRIDAY AND SATURDAY...MAINLY LOWER/MID 50S FRIDAY AND MID/
UPPER 50S SATURDAY.
INCREASING SOUTHWEST FLOW WILL TRANSPORT MOISTURE AND EVEN SOME
INSTABILITY INTO THE CENTRAL PLAINS FOR THE WEEKEND. HAVE SOME
MENTION OF SHOWERS FOR AT LEAST PARTS OF THE AREA FROM SATURDAY INTO
MONDAY...WITH HIGHEST CHANCES FOR SOUTHEAST NEBRASKA AND SOUTHWEST
IOWA. ONE MAIN MID LEVEL LOW TRACKS ALONG THE CANADIAN BORDER WHILE
THE OTHER MOVES EAST ACROSS NORTH TEXAS. THAT SHOULD KEEP THE
HEAVIEST PCPN AMOUNTS OUT OF OUR AREA.
&&
.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1126 AM CST MON DEC 8 2014
VFR CONDITIONS ARE EXPECTED FOR MOST OF THE TAF PERIOD...BUT A
COLD FRONT WILL MOVE THROUGH ALL 3 TAF SITES THIS EVENING WITH
INCREASING NORTHWEST WINDS BEHIND THE FRONT. TRAILING BEHIND THE
COLD FRONT WE WILL LIKELY SEE AT LEAST A SCT SC DECK AT ALL
LOCATIONS...BUT THIS MAY BE A BKN MVFR DECK FOR A FEW HOURS AT
KOFK/KOMA DURING THE LATE EVENING INTO THE EARLY MRNG.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...MILLER
LONG TERM...MILLER
AVIATION...BOUSTEAD
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
315 PM EST MON DEC 8 2014
.SYNOPSIS...
LOW PRESSURE WILL MOVE NORTH A COUPLE HUNDRED MILES OFF THE NORTH
CAROLINA COAST TONIGHT. CLOUDS WITH AREAS OF LIGHT RAIN OR DRIZZLE
MAY CONTINUE INTO TUESDAY MORNING. CANADIAN HIGH PRESSURE WILL
BUILD SOUTH INTO THE CAROLINAS TUESDAY NIGHT THROUGH LATE IN THE
WEEK. DRY WEATHER AND BELOW-NORMAL TEMPERATURES ARE EXPECTED THE
LATTER HALF OF THE WEEK INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 PM MONDAY...WEDGE REMAINS IN PLACE THROUGH THE EARLY
PART OF THE PERIOD. SOME VERY WEAK WAA AND PVA WILL ALLOW FOR SOME
LIGHT RAIN TO BREAK OUT...CURRENTLY OVER FAR SWRN ZONES...AND THEN
BLOSSOMING AREA-WIDE AFTER SUNSET. 12ZWRF AND HRRR SEEM FAIRLY
WELL INITIALIZED AND WERE FOLLOWED RATHER CLOSELY. THESE MODELS
MAY JUST BE A TAD TOO FAST AND HIGH IN QPF SINCE THE COLUMN HAS
BEEN SLOW TO SATURATE...NOT SURPRISING GIVEN THE VERY DRY MID
LEVEL AIR SHOWING UP IN THIS MORNINGS RAOBS. LATTER PART OF THE
NIGHT SHOULD FEATURE A QUICK DOWNWARD TREND IN POPS AS THE WEDGE
ERODES...TAKING AWAY THE LAYER TO BE OVERRUN...AND THE WEAK
UPGLIDE SHUTS OFF. A LAST-MINUTE GLANCE AT THE 18Z WRF SEEMS TO
IMPLY THAT THE MEASURABLE RAINFALL HAS TROUBLE GETTING MUCH EAST
INTO THE CAPE FEAR REGION...POSSIBLY LOSING THE SATURATION BATTLE
TO THOSE AREAS WHERE IT GOT A BIT WARMER TODAY LEADING TO LOWER RH
VALUES.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 300 PM MONDAY...ONE SIGNIFICANT UPPER DISTURBANCE SHOULD BE
OUT OF THE AREA BY DAYBREAK TUESDAY...BUT A SECOND STRONG
DISTURBANCE SHOULD ARRIVE TUESDAY EVENING. THE STRONG CYCLONICALLY
CURVED UPPER PATTERN IS PROBABLY ONE WE SHOULD GET USED TO IF
RECENT WINTER OUTLOOKS ARE TO BE BELIEVED.
NW SURFACE WINDS BEHIND DEPARTING SURFACE LOW PRESSURE TUESDAY
MORNING WILL DRAIN THE OLD WEDGE AIRMASS SOUTHEASTWARD ACROSS THE
AREA. THERE SHOULD BE NO SIGNIFICANT SYNOPTIC LIFT REMAINING BUT
THE DEPTH OF LOW STRATUS CLOUDS (2500-3000 FT) IS SUFFICIENT FOR
AREAS OF DRIZZLE THROUGH THE MORNING. A LITTLE SUNSHINE IS
EXPECTED TO BREAK THROUGH DURING THE AFTERNOON WITH HIGHS
STRUGGLING TO APPROACH 50.
A STRONG UPPER DISTURBANCE WILL DIVE SE INTO THE AREA TUESDAY
EVENING. ALTHOUGH RELATIVELY MOISTURE STARVED...THERE IS A LOT OF
COLD AIR ALOFT WITH 500 MB TEMPS PROGGED TO FALL TO -26C TO -28C.
ISENTROPIC FIELDS ARE NEUTRAL BUT Q-VECTORS INDICATE DYNAMIC
PROCESSES WILL ATTEMPT TO SQUEEZE A LITTLE PRECIPITATION OUT GIVEN
ANY OPPORTUNITY...ESPECIALLY FROM COASTAL SC EASTWARD OFFSHORE.
FOR THIS REASON I HAVE INTRODUCED SOME SPRINKLES TO THE FORECAST
ALONG THE COAST TUESDAY EVENING...WITH INCREASING SHOWER CHANCES
OFFSHORE. ONCE THE UPPER TROUGH PUSHES ACROSS AND VORTICITY ADVECTION
GOES NEGATIVE...DOWNWARD MOTION SHOULD HELP SCOUR OUT CLOUDS.
DEEP NW FLOW AND A SUBSIDENCE INVERSION BUILDING DOWN FROM ALOFT
SHOULD GIVEN US SUNNY TO MOSTLY SUNNY SKIES AND COOL TEMPERATURES
WEDNESDAY. HIGHS MID 50S WITH LOWS WED NIGHT NEAR FREEZING.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 300 PM MONDAY...MEDIUM RANGE GUIDANCE IS STABLE WITH REGARDS TO A DRY
AND COOL FORECAST UNDER AN OMEGA BLOCK ALOFT. A COUPLE OF WEAKER
SURFACE TROUGHS WILL MOVE ACROSS THE AREA THURSDAY AND FRIDAY WHICH
WILL ONLY SERVE TO REINFORCE THE ANTECEDENT COLD AIR AND KICK UP
WINDS A BIT. THESE TROUGHS WILL BE ROTATING AROUND THE MASSIVE
STACKED LOW ACROSS THE NORTHEAST.
THE WEEKEND WILL BE NICER WITH LIGHTER WINDS AND SLOWLY MODERATING
TEMPERATURES AS HIGH PRESSURE SLOWLY MEANDERS OVERHEAD. WITH
BASICALLY NO WARM AIR ADVECTION AS THE WINDS WILL MAINTAIN A
NORTHERLY COMPONENT...AIR MASS MODIFICATION WILL BE THE PRIMARY
DRIVER OF WARMER TEMPERATURES. WE HAVE HIGHS IN THE 50S THURSDAY
THROUGH SATURDAY WITH 60S SLOWLY ENTERING THE FORECAST SUNDAY AND
MONDAY. SAME PROGRESSION WITH LOWS ALBEIT WITH A LOWER RANGE. NEAR
FREEZING FRIDAY MORNING WARMING TO THE MIDDLE TO UPPER 30S MONDAY
AM. NO POPS.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 18Z...THIS AFTERNOON TERMINALS ARE VFR WITH 3-5K CIGS AT
KMYR/KFLO AND 6-8K CIGS OR BETTER AT THE REMAINING TERMINALS. VERY
LIGHT RAIN IS INCREASING AND STREAMING N FROM SW OF KMYR TO KFLO.
MOST OF THIS IS PROBABLY NOT REACHING THE GROUND ATTM BUT COINCIDES
WITH LOWEST CIGS. WINDS ARE N-NE 10-15KT WITH OCCASIONAL 20K GUSTS
AT THE COASTAL TERMINALS.
AS A UPPER IMPULSE APPROACHES RAIN IS EXPECTED TO INCREASE AND
SPREAD ACROSS THE REMAINING TERMINALS. THE RAIN WILL SATURATE THE
LOW LEVELS AND CAUSE MVFR CIGS TO DEVELOP. GREATEST CONFIDENCE OF
MVFR CIGS THIS AFTERNOON WILL BE WHERE RAIN IS CURRENTLY
OCCURRING...FROM KMYR TO KFLO. CONFIDENCE IS MODERATE TO HIGH MVFR
CIGS WILL DEVELOP BUT THE TIMING OF THE ONSET IS LOW. WITH A COOL
AIRMASS IN PLACE THE LOW LEVELS SHOULD EVENTUALLY BECOME SATURATED
AND BR/IFR CIGS WILL BECOME MORE LIKELY IN THE EVENING. RAIN WILL
END FROM WSW TO ENE OVERNIGHT BUT LOW CIGS WILL REMAIN THROUGH
SUNRISE. EXPECT IMPROVEMENT TO MVFR BY MID MORNING AS NW DOWNSLOPE
WINDS BEGIN TO DRY OUT THE LOW LEVELS.
EXTENDED OUTLOOK...MVFR/IFR CIGS TUESDAY MORNING BECOMING VFR
TUESDAY AFTERNOON. OTHERWISE VFR THROUGH SAT.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 300 PM MONDAY...STRONG SMALL CRAFT ADVISORY IN EFFECT FOR THE
DURATION OF THE PERIOD. HIGH PRESSURE WEDGE AND A WELL OFFSHORE LOW
WORKING IN TANDEM TO KEEP STRONG PRESSURE GRADIENT IN PLACE.
OVERNIGHT THE WEDGE WEAKENS CONSIDERABLY AND THE LOW RETROGRADES
TOWARDS CAPE HATTERAS BEFORE TURNING TO THE NORTH. WIND WILL BACK IN
DIRECTION WHILE WINDS GRADUALLY RELAX IN RESPONSE TO THE GRADIENT
EASING...BUT NOT FAST ENOUGH FOR SUB-ADVISORY WIND OR WAVES.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 300 PM MONDAY...DEEPENING LOW PRESSURE OFF THE MID-ATLANTIC
COAST TUESDAY MORNING SHOULD MOVE NORTH TO COASTAL NEW ENGLAND
WEDNESDAY. THIS WILL ALLOW CANADIAN HIGH PRESSURE CENTERED JUST
NORTH OF THE GREAT LAKES WILL GRADUALLY BUILD SOUTHWARD ACROSS THE
EASTERN U.S. THROUGH MID-WEEK. NORTHWEST WINDS WILL CONTINUE
ACROSS THE WATERS THROUGH THE PERIOD...STRONGEST TUESDAY MORNING
AND SURGING AGAIN TOWARD 20 KNOTS TUESDAY EVENING AS A POOL OF
COLD AIR ALOFT MOVES ACROSS THE AREA.
RECENT MODEL TRENDS HAVE BEEN TOWARD SOMEWHAT STRONGER WINDS
LOCALLY AND ALSO STORMINESS ACROSS THE NORTHWESTERN ATLANTIC WITH
MORE BACKSWELL IMPACTING OUR WATERS. FOR THIS REASON WE HAVE
EXTENDED THE SMALL CRAFT ADVISORY INTO TUESDAY MORNING FOR THE SC
WATERS AND INTO EARLY WEDNESDAY MORNING FOR THE NC WATERS. SEAS
WILL BE SLOW TO IMPROVE WITH LATEST WAVEWATCH GUIDANCE INDICATING
AN IMPRESSIVE 12-13 SECOND EASTERLY SWELL FEEDING INTO THE AREA
THROUGH WEDNESDAY.
LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 300 PM MONDAY...COMPARATIVELY SPEAKING...WINDS AND SEAS WILL SEE
MARKEDLY IMPROVED CONDITIONS FOR LATE WEEK INTO THE WEEKEND. WINDS
WILL MAINTAIN A NORTHERLY COMPONENT...NORTHWEST FOR THE MOST PART
AROUND TEN KNOTS. SEAS WILL BE 1-3 FEET DUE PRIMARILY TO A WEAK WIND
WAVE AND A SLIGHTLY MORE SIGNIFICANT EASTERLY SWELL COMPONENT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EST TUESDAY FOR AMZ254-256.
SMALL CRAFT ADVISORY UNTIL 6 AM EST WEDNESDAY FOR AMZ250-252.
&&
$$
SYNOPSIS...TRA
NEAR TERM...FBB
SHORT TERM...TRA
LONG TERM...SHK
AVIATION...FBB/MRR
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
335 PM CST MON DEC 8 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 335 PM CST MON DEC 8 2014
CLOUD COVER TRENDS AND IF WE GET ANY FOG DEVELOPMENT TONIGHT ARE
THE MAIN FORECAST CONCERNS.
NORTHWESTERLY FLOW ALOFT CONTINUES AS THE UPPER TROUGH DIGS INTO
THE GREAT LAKES. THE SFC LOW HAS BEEN MOVING OFF OF THE ARROWHEAD
OF MN AND WILL CONTINUE TO HEAD EAST...ALLOWING HIGH PRESSURE TO
BUILD IN FROM ONTARIO INTO THE NORTHERN PLAINS TONIGHT. SOME
BREAKS IN THE CLOUDS HAVE STARTED IN THE NORTHERN AND WESTERN
CWA...WHICH THE RAP HAS A DECENT HANDLE ON. CLOUDS SHOULD
GRADUALLY CLEAR FROM NORTH TO SOUTH THIS EVENING...AND WE SHOULD
BE FAIRLY CLEAR BY MORNING. TEMPS WILL DROP INTO THE SINGLE
DIGITS...AND WINDS SHOULD BECOME FAIRLY LIGHT AS THE CENTER OF THE
HIGH MOVES OVER THE AREA. THE RAP AND HRRR HAVE SIGNS OF SOME
PATCHY FOG FORMATION...BUT ALONG WITH THE LIGHT WINDS AND CLEAR
SKIES WILL BE DRIER AIR AT THE SFC. THINK THAT CHANCES WILL NOT BE
HIGH ENOUGH FOR FOG TO INCLUDE IN THE GRIDS AT THIS POINT...BUT
WILL KEEP AN EYE ON IT.
TOMORROW...AN EMBEDDED SHORTWAVE WILL MOVE INTO SD...BUT
THE COLUMN WILL BE TOO DRY TO DO MUCH AND NONE OF THE MODELS ARE
PRODUCING ANY PRECIP. THE SFC HIGH WILL BEGIN TO MOVE OFF TO THE
EAST...AND RETURN FLOW WILL SET UP BY MORNING AND CONTINUE
THROUGHOUT THE DAY ON TUESDAY. WITH A COLD START AND 850MB TEMPS
STILL CLOSE TO ZERO EARLY IN THE DAY...TEMPS WILL STAY IN THE 20S
EVEN WITH WARM AIR ADVECTION. THE SOUTH WINDS AND WARM ADVECTION
WILL CONTINUE INTO TUESDAY NIGHT AS UPPER RIDGING BUILDS INTO THE
REGION. THERE SHOULD BE ENOUGH MIXING TO KEEP LOWS IN THE TEENS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 335 PM CST MON DEC 8 2014
WEDNESDAY THROUGH THURSDAY...UPPER RIDGING WILL CONTINUE TO BUILD
ACROSS THE NORTHERN PLAINS. SOUTHERN WINDS WILL CONTINUE AS THE
SFC TROUGH REMAINS TO OUR NORTHWEST...BRINGING 850MB TEMPS BACK UP
WELL ABOVE ZERO AND SOME CLOSE TO 10 C. THE SPOILER MAY BE IF WE
GET STRATUS COMING BACK UP AND REMAINING OVER THE REGION. THE NAM
WAS EVEN TRYING TO PUT SOME VERY LIGHT PRECIP OUT THURSDAY OVER
THE EASTERN COUNTIES. WILL LEAVE ANY DRIZZLE MENTION OUT FOR NOW
BUT BUMPED UP CLOUDS A BIT IN THE FAR EAST. HIGHS SHOULD SLOWLY
BECOME WARMER THROUGH WEDNESDAY AND THURSDAY...REACHING BACK
TOWARDS THE 30 MARK AND THEN INTO THE MID AND UPPER 30S ON
THURSDAY.
THURSDAY NIGHT TO MONDAY...MODELS CONTINUE TO AGREE ON 500MB RIDGING
ACROSS THE NORTHERN PLAINS FOR THE END OF THE WEEK. NAEFS SHOWS
850MB TEMPS RANGING FROM 2 TO 3 STANDARD DEVIATIONS ABOVE NORMAL
STARTING EARLY FRIDAY THROUGH LATE SATURDAY...AS 850MB TEMPS REACH
TO 12C TO 16C FRIDAY NIGHT. MODELS INDICATE WINDS FROM THE SOUTH
INSTEAD OF THE SFC WARMING SW OR WEST PLUS THE POTENTIAL FOR LOW
STRATUS LAYER ADVECTING NORTH KEEPING TEMPS COOLER SATURDAY. FOR NOW
WILL CONTINUE WITH A BLEND AS CLOUDS WILL MAKE OR BREAK TEMPS...EVEN
WITH LOW SUN ANGLE. UPR 30S TO 40 WITH CLOUDS...WITHOUT MID TO UPR
40S POSSIBLE FRIDAY AND SATURDAY. FROPA SUNDAY WILL BRING LIGHT PCPN
CHC TO THE FA AND BRING TEMPS DOWN TO NEAR NORMAL WITH HIGHS IN THE
LOW 20S BY MONDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1230 PM CST MON DEC 8 2014
SECONDARY COLD FRONT PUSHING ACROSS THE FA THIS MORNING WITH WINDS
TURNING TO THE NNW WITH GUSTS TO AROUND 25MPH. GUSTS TO CONTINUE FOR
2 TO 3 HOURS AFTER FROPA THEN WINDS WILL GRADUALLY DIMINISH AS SFC
HIGH PRESSURE BUILDS INTO THE NORTHERN PLAINS TONIGHT. CIGS WILL
IMPROVE FROM MFVR TO VFR AS CIGS LIFT AND SCT OUT THIS AFTN INTO THE
EVENING FROM WEST TO EAST WITH THE EXCEPTION BEING AT BJI WHERE MFVR
CIGS MAY LINGER INTO THE MORNING TOMORROW.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
SHORT TERM...JR
LONG TERM...JR/JK
AVIATION...JK
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1249 PM CST MON DEC 8 2014
.UPDATE...
ISSUED AT 1249 PM CST MON DEC 8 2014
NO SIGNIFICANT UPDATES TO THE GOING FORECAST OTHER THAN TO
POPULATE THE LATEST SIGNIFICANT WEATHER ELEMENTS. ALSO MADE SOME
MINOR ADJUSTMENTS BASED ON LATEST SATELLITE IMAGERY. SKIES
CONTINUE TO CLEAR ACROSS FROM NORTH TO SOUTH. HOWEVER A BAND OF
STRATUS REMAINS FROM WESTERN INTO SOUTH CENTRAL AND EASTERN NORTH
DAKOTA.
UPDATE ISSUED AT 1005 AM CST MON DEC 8 2014
MAIN CHALLENGE THIS MORNING WILL BE CLOUD COVER AND TEMPERATURES.
WIDESPREAD STRATUS BEHIND THE EXITING LOW PRESSURE SYSTEM
EXTENDING FROM NORTHWEST THROUGH CENTRAL AND EASTERN NORTH DAKOTA.
COLD HIGH PRESSURE BUILDING SOUTH IS CLEARING OUT THE STRATUS OVER
THE NORTH CENTRAL...AND WILL CONTINUE TO ERODE NORTH TO SOUTH
THROUGH THE DAY. WITH THE CLEAR SKIES NORTH...TEMPERATURES ARE
ACTUALLY FALLING WITH THE LOSS OF CLOUD COVER AND COLD ADVECTION.
UPDATED CLOUD COVER KEEPING CLOUDS THROUGH THE MORNING MOST AREAS
AND CLEARING FROM NORTH TO SOUTH. ALSO ADJUSTED TEMPERATURES WITH
STEADY OR FALLING TEMPERATURES NORTH TO RISING SLIGHTLY OVER THE
SOUTHWEST.
UPDATE ISSUED AT 640 AM CST MON DEC 8 2014
UPDATED THE FORECAST TO INDICATE OVERCAST SKIES OVER NORTHWESTERN
AND CENTRAL NORTH DAKOTA THIS MORNING. THE STRATUS SHOULD BEGIN TO
ERODE LATER THIS AFTERNOON. IN THE MEANTIME...TEMPERATURES UNDER
THE STRATUS DECK SHOULD HOLD STEADY THROUGH MID-DAY...THEN COULD
BEGIN TO INCREASE AS CLOUDS BREAK UP LATER THIS AFTERNOON. UPDATED
THE TEMPERATURE GRIDS TO REFLECT THIS SCENARIO AS A RESULT.
UPDATE ISSUED AT 522 AM CST MON DEC 8 2014
QUICK UPDATE TO INCREASE CLOUD COVER WEST AND REMOVE PATCHY FOG.
THE STRATUS DECK ACROSS SOUTHERN SASKATCHEWAN HAS TAKEN A MORE
SOUTHERLY JOG WITHIN THE PAST COUPLE OF HOURS. THIS WILL PUT MOST
OF WESTERN NORTH DAKOTA UNDER CLOUDY SKIES THROUGH THE EARLY
MORNING HOURS. DUE TO INCREASED CLOUD COVER AND PERSISTENT WEST
WINDS...REMOVED THE POTENTIAL FOR PATCHY FOG ACROSS THE WEST.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 234 AM CST MON DEC 8 2014
THE MAIN FOCUS FOR THE SHORT TERM IS CLOUD COVER AND TEMPERATURES.
THE LOW PRESSURE RESPONSIBLE FOR THE LIGHT SNOW LAST NIGHT
CONTINUES TO PUSH OUT OF NORTH DAKOTA THIS MORNING. THE LOW IS
DRAGGING AN AREA OF LOW STRATUS IN ITS WAKE. THE STRATUS HAS BEEN
CONFINED TO ALONG AND EAST OF THE MISSOURI RIVER SO FAR. THERE IS
A POSSIBILITY THAT THE STRATUS WILL EXTEND A LITTLE FURTHER WEST
THIS MORNING BEFORE IT BEGINS CLEARING FROM WEST TO EAST BY THIS
AFTERNOON. THE LATEST HRRR RUN INDICATES CLOUD COVER COULD ENTER
WILLISTON WITHIN THE NEXT COUPLE OF HOURS.
THE STRATUS WILL WREAK HAVOC ON TEMPERATURES EARLY THIS
MORNING...INTO THE AFTERNOON HOURS. AREAS UNDER THE STRATUS WILL
SEE LITTLE CHANGE IN TEMPERATURES WITH SLIGHTLY WARMER READINGS
EARLY THIS MORNING AND SLIGHTLY COOLER READINGS FOR DAYTIME HIGHS.
WHILE AREAS UNDER CLEAR SKIES WILL HAVE AN EASIER TIME REBOUNDING
FROM OVERNIGHT LOWS. THIS IS REFLECTED IN THE HIGH TEMPERATURE
FORECAST FOR TODAY WITH 30S EXPECTED ACROSS THE CLEAR SOUTHWEST
AND TEENS/20S EXPECTED ACROSS THE NORTHERN JAMES VALLEY.
OVERALL A RATHER PLEASANT DAY IS EXPECTED AS WINDS WILL CONTINUE
TO DIMINISH AND SKIES SLOWLY CLEAR THROUGH THE DAY.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 234 AM CST MON DEC 8 2014
BROAD UPPER LEVEL RIDGING IS FORECAST BUILD INTO THE REGION
THROUGH THE END OF THE WEEK...THEN BEGIN TO BREAK DOWN OVER THE
WEEKEND.
FOR TUESDAY...A RIDGE-RUNNER SHORTWAVE IS FORECAST TO TRAVERSE
NORTH DAKOTA. EVEN THOUGH UPPER LEVEL SUPPORT SHOULD BE STRONG
ENOUGH TO GENERATE ELEVATED SNOW SHOWERS...THE MODEL SOUNDINGS
INDICATE THAT A DRY THERMODYNAMIC PROFILE UP TO 600MB WILL BE IN
PLACE. THEREFORE...VIRGA WILL LIKELY BE OBSERVED TUESDAY.
HOWEVER...WOULD NOT BE SURPRISED IF A FEW FLAKES REACHED THE
SURFACE SOUTHWEST OF THE MISSOURI RIVER TUESDAY. DUE TO THE STRONG
UPPER FORCING BUT DRY BOUNDARY LAYER CONDITIONS...HANDLED THIS
SCENARIO WITH SILENT POPS IN THE GRIDS FOR NOW.
THE UPPER RIDGE IS FORECAST TO SHARPEN OVER THE NORTHERN PLAINS
WEDNESDAY THROUGH FRIDAY...WITH FRIDAY FORECAST TO BE THE WARMEST
DAY OF THE EXTENDED. FRIDAY FORECAST HIGH TEMPERATURES RANGE FROM
THE UPPER 30S TO UPPER 40S.
THE UPPER RIDGE IS PROGGED TO BEGIN TO BREAK DOWN SATURDAY AS A
LONG WAVE TROUGH ENTERS THE ROCKIES. THE MAIN ENERGY FROM THE
TROUGH IS GENERALLY FORECAST TO MOVE EAST INTO NORTH DAKOTA
SATURDAY NIGHT INTO SUNDAY. WILL CONTINUE TO BROAD BRUSH A SLIGHT
CHANCE OF SNOW SATURDAY NIGHT/SUNDAY GIVEN THE MODEL TO MODEL AND
RUN TO RUN INCONSISTENCIES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1249 PM CST MON DEC 8 2014
PERSISTENT STRATUS AT KISN/KDIK/KBIS/KJMS. CLEARING FROM NORTH TO
SOUTH WITH KMOT CLEARING SOON. REMAINING TAFS CLEARING DURING THE
AFTERNOON OR EARLY EVENING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TWH
SHORT TERM...AJ
LONG TERM...TM
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS PORTLAND OR
1020 AM PST MON DEC 8 2014
.SYNOPSIS...A BUSY WEATHER PATTERN WILL PREVAIL THIS WEEK FOR
SOUTHWEST WASHINGTON AND NORTHWEST OREGON WITH WET AND WINDY WEATHER
AT TIMES. BROAD LOW PRESSURE OVER THE GULF OF ALASKA AND A STRONG
PACIFIC JET STREAM WILL ROTATE A SERIES OF INCREASINGLY STRONG
FRONTAL SYSTEMS INTO THE PACIFIC NORTHWEST THROUGH MIDWEEK. THE MAIN
UPPER LOW WILL OPEN UP AND MOVE ACROSS THE PACIFIC NORTHWEST AS AN
OPEN TROUGH WITH THE FOCUS OF HEAVIEST RAIN SHIFTING SOUTHWARD INTO
CALIFORNIA BY THE END OF THE WEEK. COOLER AND SHOWERY WEATHER IS
EXPECTED THURSDAY NIGHT AND FRIDAY WITH A DRYING TREND POSSIBLE FOR
THE WEEKEND.
&&
.UPDATE...MINOR CHANGES FOR THE IMMEDIATE PERIOD WITH THE LEADING
BAND OF WARM PROCESS RAIN EASILY VISIBLE ON THE LANGLEY HILL RADAR.
EXPECT A SLOW PROGRESSION OF THE RAIN EASTWARD AS THE UPPER JET
BECOMES MORE ALIGNED WITH THE ADVANCING OCCLUDED FRONT. SO IT LOOKS
LIKE MOST INLAND AREAS WILL STAY DRY WITH THE RAIN REACHING THE
NORTH COAST IN EARNEST CLOSER TO NOON. WOULD EXPECT INLAND RAIN TO BE
IN PLACE ACROSS THE NORTH AROUND OR PERHAPS A BIT AFTER THE EVENING
COMMUTE. AMOUNTS ARE NOT TERRIBLY IMPRESSIVE WITH THIS FIRST WAVE.
FOG BEGAN LIFTING AROUND DAYBREAK BUT STILL SEE SOME BROADER AREAS
IN PLACE PER WEBCAMS. DON`T EXPECT MUCH IMPACT THOUGH SO CANCELLED
THE DENSE FOG ADVISORY EARLIER THIS MORNING.
WIND FORECAST STILL SOMEWHAT PROBLEMATIC TONIGHT. 15Z HRRR TIMING
GETS TO 06Z/10PM TONIGHT AND STILL DOESN`T QUITE REACH HIGH WIND
CRITERIA AND IS ALSO SUPPORTED BY THE CONTINUES WEAKLY OFFSHORE FLOW
FOR THE IMMEDIATE COAST. BETTER CHANCE FOR HIGHER COASTAL WIND
SPEEDS APPEARS TO BE LATER OVERNIGHT TONIGHT AND EVEN MORE SO AROUND
MIDDAY TUESDAY WITH WIND DIRECTIONS REACHING BETTER VERTICAL
ALIGNMENT AND PROMOTING BETTER POTENTIAL FOR TURBULENT EDDIES TO
REACH LOWER IN THE ATMOSPHERE. EVEN THEN, THIS IS LOOKING LIKE A
LOWER END EVENT WITH WIDESPREAD GUSTS MAYBE UP TO 65 MPH BUT MOST
LIKELY IN THE 55 TO 60 MPH RANGE. TYPICAL FAVORED LOCATIONS ALONG
THE HEADLANDS DO SEEM LIKE 65 MPH IS WELL WITHIN REACH. PLAN ON
ADDRESSING THE COASTAL HIGH WIND WATCH AROUND MIDDAY TODAY.
FINALLY...LOOKING AT EXPECTED INCOMING SEAS AND RAINS OVER THE NEXT
FEW DAYS PLUS TIDES NEARING THEIR PEAKS UNDER THE FULL MOON...COULD
LEND TOWARD SOME TIDAL OVERFLOW AND ESPECIALLY FOR THE WILLIPA BAY
SYSTEM. WILL BE ASSESSING FURTHER TODAY AS WELL. /JBONK
&&
.PREV DISC... /ISSUED 412 AM PST MON DEC 8 2014/
SHORT TERM...TODAY THROUGH THURSDAY...WATER VAPOR IMAGERY AND
SATELLITE-DERIVED WINDS SHOW A POWERFUL JET STREAM SETTING UP ACROSS
THE PACIFIC...WITH WINDS ALREADY 180 KT+ WITHIN THE JET STREAM NEAR
300 MB. THIS POWERFUL JET STREAM WILL GUIDE A SERIES OF STRONG
FRONTAL SYSTEMS TOWARD THE WEST COAST THIS WEEK...WITH THE NEXT
SYSTEM SLATED TO ARRIVE TONIGHT AND TUESDAY MORNING.
THIS MORNING THE MOST IMMEDIATE CONCERN IS AREAS OF DENSE FOG IN THE
WILLAMETTE VALLEY SOUTH OF SALEM...WITH VISIBILITY DOWN TO A FEW
HUNDRED FEET AT TIMES IN PORTIONS OF CORVALLIS AND EUGENE. AREA
WEBCAMS SUGGEST THE DENSE FOG IS FAIRLY WIDESPREAD AT THE MOMENT...
SO DECIDED TO ISSUE A DENSE FOG ADVISORY UNTIL 9 AM. THE FOG MAY LIFT
AT TIMES DUE TO HIGH CLOUDS STREAMING OVER THE AREA AHEAD OF OUR NEXT
FRONTAL SYSTEM.
BACK TO THE ACTIVE PACIFIC STORM TRACK...MODELS ARE VARYING ON THE
DETAILS BUT IT DOES APPEAR THAT WE WILL HAVE AT LEAST TWO DISTINCT
STRONG FRONTAL SYSTEMS MOVE ONSHORE THE NEXT 2 DAYS. THE FIRST SYSTEM
IS TAKING SHAPE NEAR 135W AND WILL APPROACH THE COAST THIS AFTERNOON
AND EVENING...WITH SOUTH WINDS INCREASING MAINLY ON THE COASTAL
WATERS AS WELL AS THE BEACHES AND HEADLANDS. A HIGH WIND WATCH IS OUT
FOR THE BEACHES AND HEADLANDS WITH A STORM WATCH OUT FOR THE COASTAL
WATERS...AS THE 00Z/06Z NAM AND GFS CONTINUE TO SUGGEST WINDS 60-70
KT+ DEVELOPING AS LOW AS 950 MB BY THIS EVENING. THIS SHOULD BE
ENOUGH TO PRODUCE GUSTS 60-70 MPH FOR THE BEACHES AND HEADLANDS...BUT
WITH GRADIENTS HIGHLY OFFSHORE IT MAY TAKE SOME TIME FOR THESE WINDS
TO MATERIALIZE ON LAND. THE FIRST STAGES OF THIS EVENT ARE STARTING
TO FALL WITHIN THE WINDOW OF HRRR GUIDANCE...AND HRRR 10M WINDS ARE
FAIRLY UNIMPRESSIVE AS THE FIRST FRONTAL SYSTEM APPROACHES EARLY THIS
EVENING...SO WE OPTED TO KEEP THE HIGH WIND WATCH A WATCH FOR THE
TIME BEING. CONFIDENCE IN STRONG COASTAL WIND INCREASES WITH THE
SECOND FRONTAL SYSTEM EXPECTED TO MOVE THROUGH TUESDAY WITH 70 KT
WINDS DOWN TO 950 MB AND GRADIENTS SOMEWHAT MORE SOUTHERLY. WOULD NOT
BE SURPRISED TO SEE SOME OF OUR WINDIER BEACHES/HEADLANDS SITES GUST
TO 75 MPH EARLY TUE...BUT GUSTS SHOULD REMAIN 55 MPH OR LESS FOR THE
COASTAL COMMUNITIES WITH THIS FRONT AS WELL.
THESE FRONTAL SYSTEMS WILL DUMP A SIGNIFICANT AMOUNT OF RAIN ON
VANCOUVER ISLAND AND THE OLYMPIC PENINSULA...WITH PERIODS OF HEAVY
RAIN POSSIBLE FOR THE WILLAPA HILLS THROUGH TUESDAY. HOWEVER IT DOES
NOT APPEAR LIKELY THAT IT WILL BE ENOUGH TO CAUSE WIDESPREAD FLOODING
OF COASTAL DRAINAGES. WILL NEED TO WATCH THE GRAYS...AS IT TENDS TO
BE FAST-RESPONDING...BUT AT THIS POINT IT DOES NOT APPEAR ENOUGH FOR
THE GRAYS RIVER TO FLOOD EITHER. WITH SEAS APPROACHING 20 FEET OR
HIGHER DEVELOPING NEAR THE MOUTH OF WILLAPA BAY...HEAVY RAIN IN THE
WILLAPA HILLS...AND TIDES RUNNING HIGH DUE TO THE RECENT FULL
MOON...THERE IS A POSSIBILITY OF TIDAL OVERFLOW IN LOW-LYING AREAS
SURROUNDING WILLAPA BAY SUCH AS RAYMOND.
A DECENT PERIOD OF RAIN WILL SPREAD ACROSS THE FORECAST AREA
TUESDAY...AND 06Z NAM BUFR SOUNDINGS SUGGEST SOME INSTABILITY
ASSOCIATED WITH THE FRONT THROUGHOUT OUR CWA. NAM LIFTED INDICES GET
AS LOW AS -2 TO -4 DEG C WITH 500-750 J/KG OF CAPE...ALONG WITH
SIGNIFICANT LIFT ASSOCIATED WITH THE FRONT. SUSPECT THIS IS ENOUGH TO
WARRANT AT LEAST A SLIGHT CHANCE OF THUNDER TUESDAY AFTERNOON AND
EVENING. WITH STRONG WINDS JUST ABOVE THE SURFACE...HEAVIER SHOWERS
AND THUNDERSTORMS MAY HAVE THE ABILITY TO MIX STRONG WINDS DOWN TO
THE SURFACE...EVEN INLAND.
DUE TO THE VERY FAST AND DYNAMIC PACIFIC JET STREAM...DETAILS BEYOND
TUESDAY RAPIDLY BECOME MORE UNCERTAIN. BROAD PARENT LOW PRESSURE OVER
THE GULF OF ALASKA WILL LIKELY DRIFT EAST TOWARD BRITISH
COLUMBIA...PUSHING THE BAROCLINIC ZONE AND STRONGEST PORTION OF THE
JET STREAM CLOSER TO U.S. WEST COAST. THESE FACTORS COMING TOGETHER
COULD BE A POWDER KEG FOR STRONG LOW PRESSURE TO DEVELOP JUST
OFFSHORE SOMETIME WED/EARLY THU...OR NOT. MODEL SOLUTIONS HAVE VARIED
WILDLY ON WHERE AND WHEN LOW PRESSURE SYSTEMS WILL DEVELOP ALONG THE
BAROCLINIC ZONE AND HOW THEY WILL TRACK. FOR EXAMPLE...THE 00Z GFS
AND GEM BOTH DEVELOPED A SUB-980 MB LOW OFF THE OREGON COAST LATE
WED...TRACKING IT UP THE COAST THROUGH ASTORIA FOR WHAT WOULD BE A
SIGNIFICANT WIDESPREAD SOUTH WIND EVENT FOR NORTHWEST OREGON AND
SOUTHWEST WASHINGTON. HOWEVER THE 06Z GFS AND 00Z ECMWF SHOW LITTLE
TO NO SIGN OF THIS. SUSPECT THERE WILL BE ANOTHER PERIOD OF STRONG
WINDS ALONG THE COAST AND PROBABLY THE COAST RANGE AS WELL
MIDWEEK...WITH GUSTY WINDS LIKELY FOR THE WILLAMETTE VALLEY AS WELL.
JUST HOW STRONG IS HIGHLY UNCERTAIN AND PROBABLY WILL CONTINUE TO BE
THROUGH AT LEAST TOMORROW MORNING. THERE IS BETTER CONFIDENCE THAT
THE MIDWEEK PERIOD WILL BE FAIRLY WET...BUT THE AMOUNT OF RAINFALL
WILL HIGHLY DEPEND ON THE TRACKS OF ANY LOWS DEVELOPING ALONG THE
FRONTAL ZONE AS IT DRIFTS ONSHORE WED/THU. OROGRAPHIC ENHANCEMENT
JUST TO THE SOUTHEAST OF DEVELOPING LOWS COULD PROVIDE A PERIOD OF
VERY HEAVY RAIN TO THE COAST RANGE. THERE SEEMS TO BE DECENT MODEL
CONSENSUS THAT THE ATMOSPHERIC RIVER AND ITS FOCUS OF HEAVIEST RAIN
SHIFT SOUTHWARD INTO CALIFORNIA BY THURSDAY AFTERNOON. RAIN WILL
TAPER TO SHOWERS AS THE PARENT UPPER LOW OPENS UP AND STARTS TO MOVE
THROUGH THE PAC NW BY THE END OF THE WEEK. TEMPERATURES WILL BE MILD
DUE TO THE SUBTROPICAL AIR MASS THROUGH MIDWEEK...WITH COOLER
TEMPERATURES POSSIBLY LOWERING THE SNOW LEVEL BACK TO THE CASCADE
PASSES BY THURSDAY NIGHT. WEAGLE
LONG TERM...FRIDAY THROUGH SUNDAY...AFTER A STORMY WEEK IT APPEARS
DRIER WEATHER WILL DEVELOP FOR THE WEEKEND AS THERE IS GOOD MODEL
CONSENSUS ON AN UPPER LEVEL RIDGE BUILDING ACROSS THE PAC NW. FRIDAY
COULD STILL BE SEASONABLY COOL AND SHOWERY AS THE WEAKENING UPPER
TROUGH PROGRESSES THROUGH THE PAC NW...WITH SNOW LEVELS NEAR THE
CASCADE PASSES. IF UPPER RIDGING DEVELOPS OVER THE WEEKEND...THERE
WILL LIKELY BE SIGNIFICANT VALLEY INVERSIONS WITH FOG BECOMING MORE
PERSISTENT FOR THE INLAND VALLEYS THROUGH THE PERIOD. WEAGLE
&&
.MARINE...WINDS AND SEAS CONTINUE TO INCREASE THIS MORNING AHEAD
OF AN OCCLUDED FRONT THAT IS APPROACHING THE WATERS. EXPECT THE
STRENGTHENING WINDS AND BUILDING SEAS THROUGH THE DAY TODAY WITH
SEAS APPROACHING 20 FT BY THIS EVENING.
THE FRONTAL BOUNDARY WILL LIE OVER THE REGION TONIGHT AND TUE. A
SERIES OF DISTURBANCES WILL MOVE ALONG THE FRONT...LIFTING IT BACK
AND FORTH TO THE N AND S. THIS WILL MAINTAIN GUSTY S WINDS AND
STEADILY INCREASING SEAS. THE NEXT LOW APPROACHES LATER THIS
EVENING...AND WINDS WILL INCREASE TO STRONG SOUTHERLY STORM FORCE
WINDS...PARTICULARLY WITH THE POSSIBILITY OF A COASTAL JET MONDAY
NIGHT AND INTO TUESDAY MORNING. HAVE UPGRADED THE STORM WATCH TO A
STORM WARNING GIVEN GOOD MODEL AGREEMENT WITH HIGHER WIND THREAT.
SEAS LOOK LIKE THEY WILL PEAK LATE TONIGHT/EARLY TUESDAY MORNING
(BEFORE SUNRISE) AROUND 25 FT.
ANOTHER SYSTEM IS ON TAP FOR TUE...WITH MORE STRONG SOUTHERLY
GALES AND SEAS BUILDING HIGHER STILL. THE STRONGEST SYSTEM
ARRIVES ON WED...WITH STORM FORCE WINDS LIKELY ONCE AGAIN. THE
SYSTEM HAS POTENTIAL TO BE STRONGER THAN CURRENTLY MODELED. WOULD
NOT BE SURPRISED IF WE GET HURRICANE FORCE WIND GUSTS SOMEWHERE ON
THE OREGON WATERS LATER WED AFTERNOON...POTENTIALLY IN A COASTAL
JET. SEAS WILL BUILD FURTHER...PEAKING AROUND 30 FT WED. BOWEN/27
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...HIGH WIND WATCH FROM 6 PM PST THIS EVENING THROUGH TUESDAY
MORNING FOR CENTRAL OREGON COAST-NORTH OREGON COAST.
WA...HIGH WIND WATCH FROM 6 PM PST THIS EVENING THROUGH TUESDAY
MORNING FOR SOUTH WASHINGTON COAST.
PZ...STORM WARNING FROM 6 PM THIS EVENING TO NOON PST TUESDAY FOR
COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.
GALE WARNING UNTIL 6 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 NOON
PST TUESDAY.
&&
$$
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
248 PM CST MON DEC 8 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 244 PM CST MON DEC 8 2014
THE MAIN QUESTION THROUGH THIS EVENING IS THE STATUS OF THE LOW
CLOUD COVER WHICH HAD BEEN SPREADING SOUTH OVER THE AREA. THAT
SPREAD HAS DONE A NEAR HALT AS THE MOISTURE ADVECTION RUNS INTO THE
HEATED AIR NEAR THE MISSOURI RIVER. IT SEEMS WITH THE START OF
EARLY EVENING COOLING THAT THE DECK WOULD AGAIN START SPREADING
SOUTH. CLEARING OF THE LOW CLOUDS HAS CONTINUED TO PROGRESS SOUTH
ACROSS NORTH DAKOTA AND WAS STARTING TO GET INTO FAR NORTHERN SOUTH
DAKOTA AT 20Z. BOTH THE NAM AND RAP SUGGEST THE 925 MB FLOW WILL
CONTINUE TO GO STRAIGHT NORTHERLY AND CONTINUE THUS OVER THE AREA
THROUGH 06Z/MIDNIGHT...THOUGH DECREASING SLOWLY DURING THE
EVENING. EXPECT THIS WILL GIVE THE DRYING CONTINUED TRANSPORT
SOUTH ACROSS THE AREA DURING THE EVENING AND NOT ALLOW THE SOLID
CLOUD COVER TO GET ALL THE WAY TO THE RIVER...OR OF IT BRIEFLY
DOES...IT SHOULD CLEAR OUT AGAIN FAIRLY QUICKLY. AM PLANNING FOR A
LITTLE INCREASE IN THE LOW CLOUDS THERE BUT WITH THE WARM AIR
THERE CURRENTLY AND DRYING FROM THE NORTH DURING THE
EVENING...HAVE KEPT THE INCREASE VERY MODEST BEFORE IT CLEARS OUT
EVERYWHERE TONIGHT.
TEMPERATURES WILL COOL STEADILY TONIGHT GIVEN THE CLEARING AND
DROPOFF IN WINDS...WITH LOWS BEING REACH ABOUT SUNRISE AT 8 AM.
WINDS BY THEN SHOULD BE PRETTY LIGHT THOUGH WITH A 5 TO 5 MPH
NORTHERLY BREEZE IN THE EAST LINGERING TO SUNUP.
TUESDAY WILL BRING AN INCREASE IN HIGH AND SOME MIDDLE CLOUDS WITH
UPPER LEVEL SHORT WAVE DRIFTING INTO THE AREA. HAVE GONE PRETTY
CONSERVATIVE IN CLOUD COVER AND IF THEY HIGHER CLOUDS ARE THICK
ENOUGH IT COULD GET MOSTLY CLOUDY FOR PART OF THE DAY. IN ANY EVENT
HEATING BY THE DECEMBER SUN WILL NOT BE ABLE TO TAKE ADVANTAGE OF
MUCH OF THE WARMING UPSTAIRS EVEN WITH NO SNOW COVER...AND FORECAST
HIGHS WILL REMAIN AROUND 30 NORTHEAST TO THE LOWER 40S SOUTHWEST.
WINDS WILL BE FAIRLY LIGHT THOUGH...WITH THE DEVELOPING
SOUTHEASTERLY SURFACE BREEZE PICKING TO 10 PLUS IN THE AFTERNOON
WEST OF THE JAMES RIVER.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 244 PM CST MON DEC 8 2014
MEDIUM AND EXTENDED FORECAST CONTINUES TO LOOK VERY WARM AND MOSTLY
DRY. TUESDAY NIGHT INTO WEDNESDAY...A MINOR SHORTWAVE WILL MOVE
ACROSS THE REGION. SOUNDINGS CONTINUE TO SHOW LIMITED MOISTURE WITH
THIS WAVE...WITH AN INCREASE IN MID-LVL CLOUDS AND VIRGA POSSIBLE
GIVEN DRY SUB-CLOUD LAYER.
THE WARMUP BEGINS TO BUILD ON WEDNESDAY BEHIND THIS SHORTWAVE
ENERGY. AS LOW LVL TEMPERATURES BUILD...SURFACE WINDS WILL SLOWLY
BEGIN TO VEER SOUTHWEST THROUGH THE DAY. WARM AIR WILL BE SLOW TO
MIX TO THE SURFACE ON WEDNESDAY...BUT NEAR 40 READINGS SHOULD BE
ATTAINABLE.
THURSDAY THROUGH SATURDAY LOOK TO BE VERY WARM AS DEEP
SOUTHWESTERLY FLOW PULLS BOTH MOISTURE AND WARM AIR OVER MUCH OF
THE CENTRAL CONUS. IT CONTINUES TO LOOK LIKE STRATUS WILL DEVELOP
AND MOVE NORTHWARD INTO THE REGION BY THURSDAY. TEMPERATURES WILL
PROGRESSIVELY WARM EACH AFTERNOON...WITH THE 40S LIKELY ON
THURSDAY AND 40S AND 50S ON FRIDAY. TEMPERATURES MAY NOT FALL VERY
FALL FRIDAY NIGHT INTO SATURDAY...AND CURRENT LOWS MAY STILL BE
TOO LOW. THE DEEP SOUTHERLY FLOW AND SUBSTANCIAL MOISTURE SHOULD
NOT ALLOW FOR ANY EXTREME JUMP ON SATURDAY...BUT A GRADUAL WARMING
INTO THE MID 50S AND POTENTIALLY EVEN DRIZZLE.
A COLD FRONT WILL SWING THROUGH THE AREA SATURDAY NIGHT INTO
SUNDAY...DROPPING TEMPERATURES BACK NEAR THEIR SEASONAL NORMALS. THE
CHANCES FOR PRECIPITATION AS THIS FRONT MOVES THROUGH CONTINUE TO
BE LOW.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1133 AM CST MON DEC 8 2014
FREQUENT CEILINGS 2-3K FEET MAINLY NORTHEAST OF A 9V9/YKN/SUX LINE
WITH GENERALLY VFR TO THE SW. THE LOW CEILINGS WILL DECREASE FROM
08/22Z TO 09/03Z WITH VFR FROM 09/03Z-18Z. NO VISIBILITY
RESTRICTIONS EXPECTED THROUGH THE PERIOD.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...
LONG TERM...DUX
AVIATION...
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
259 PM CST MON DEC 8 2014
.DISCUSSION...
LOW CLOUDS WEST AND NORTHWEST OF THE METROPLEX AND ALONG THE
RED RIVER WILL CONTINUE TO ERODE THIS AFTERNOON WITH CLEAR SKIES
EXPECTED BEFORE SUNSET. THIS WILL AGAIN LEAD TO A GOOD NIGHT FOR
STRONG RADIATIONAL COOLING WITH FOG FORMATION BEGINNING AFTER
MIDNIGHT. AREAS OF DENSE FOG ARE POSSIBLE IN THE PRE-DAWN HOURS
THROUGH THE EARLY MORNING COMMUTE. EXPECT THE FOG WILL BURN OFF IN
THE LATE MORNING HOURS. ONCE THE FOG BURNS OFF...THE REST OF
TUESDAY WILL BE SUNNY WITH HIGHS IN THE MID 60S.
WEDNESDAY AND THURSDAY...SEVERAL SHORT WAVES WILL BE AFFECTING
THE REGION DURING THE PERIOD WHILE MOISTURE OVER THE SOUTHERN
ROCKIES AND NORTHERN MEXICO SPREADS EASTWARD. THIS WILL RESULT A
RETURN OF CLOUDY SKIES AND A LOW CHANCE OF LIGHT SHOWERS OVER THE
WESTERN COUNTIES WEDNESDAY NIGHT AND THURSDAY. HIGHS WILL BE A
LITTLE COOLER DUE TO THE INCREASE IN CLOUD COVER.
FRIDAY AND SATURDAY...UPPER LEVEL RIDGING WILL BE MOVING ACROSS
THE REGION. THUS...A LITTLE MORE SUN...WARMER HIGHS AND AN
INCREASE IN SOUTH WINDS.
SUNDAY THROUGH MONDAY...CONFIDENCE IS BUILDING THAT A STRONG UPPER
CLOSED LOW WILL MOVE DIRECTLY ACROSS THE REGION WITH THE
POTENTIAL TO PRODUCE OUR FIRST GOOD RAIN EVENT OF DECEMBER. ALL
MODELS ARE NOW IN BETTER AGREEMENT WITH THE TRACK AND STRENGTH OF
THIS SYSTEM. THE ECMWF HAS A CORE THAT IS SLIGHTLY DEEPER AND SEVERAL
DEGREES COLDER THAN THE GFS DURING ITS PASSAGE THROUGH THE STATE.
AS IT COMES OUT OF THE SOUTHERN ROCKIES SUNDAY MORNING...STRONG
CYCLOGENESIS WILL TAKE PLACE IN WEST TEXAS WITH THE SURFACE LOW
MOVING ALONG I-20 AND INTO NORTHERN LOUISIANA BY MONDAY EVENING. A
COLD FRONT WILL MOVE ACROSS THE FORECAST AREA SUNDAY AFTERNOON AND
EVENING...AND THIS WILL BE THE BEST TIME PERIOD FOR STRONG
CONVECTION. RIGHT NOW...DYNAMICS AND INSTABILITY ON SUNDAY
AFTERNOON/EVENING DO JUSTIFY STRONG THUNDERSTORMS. IF THE SYSTEM
WAS NOT VERTICALLY STACK MOVING ACROSS THE CWA...THEN DIRECTIONAL
SHEAR WOULD BE MORE FAVORABLE FOR SEVERE STORMS. THERE COULD BE
SOME WRAP-AROUND PRECIPITATION LATE SUNDAY NIGHT INTO MONDAY AS
THE SYSTEM EXITS THE REGION. 75
&&
.AVIATION...
/ISSUED 1234 PM CST MON DEC 8 2014/
FOR THE 18Z TAFS...THE SHORT TERM FORECAST FOR MVFR STRATUS AND
THEN FOG POTENTIAL OVERNIGHT ARE THE PRIMARY AVIATION WEATHER
CONCERNS.
17Z AIRCRAFT SOUNDINGS SHOWED A SATURATED LAYER JUST A FEW HUNDRED
FEET THICK WITHIN THE MVFR STRATUS DECK IN PLACE OVER THE DFW
AREA. THE ONLY REASON THE CLOUDS HAVE BEEN HANGING AROUND SO LONG
WITHIN THIS THIN LAYER OF SATURATION IS BECAUSE THESE CLOUDS WERE
FOUND WITHIN A STEEP TEMPERATURE INVERSION. THIS INVERSION IS VERY
STABLE...AND AS A RESULT IS DAMPENING VERTICAL MOTIONS/MIXING THAT
WOULD HAVE OTHERWISE MIXED DRY AIR THROUGH THIS LAYER OF CLOUDS BY
NOW. AT ANY RATE...THESE CLOUDS ARE STILL EXPECTED TO MIX OUT THIS
AFTERNOON...AND VISIBLE SATELLITE IMAGERY SHOWS THAT THIS IS
FINALLY STARTING TO TAKE PLACE. EXPECT THAT MOST DFW AREA SITES
WILL SEE STRATUS SCATTER OUT AROUND 19Z...BECOMING CLEAR AT THE
LOW-LEVELS AFTER 21Z.
LATE MORNING SURFACE ANALYSIS INDICATED THAT A BROAD RIDGE OF HIGH
PRESSURE WAS IN PLACE ACROSS THE SOUTHERN PLAINS. THIS WILL KEEP
WINDS LIGHT AND NORTHERLY OVER ALL AREA TAF SITES THROUGH SUNSET.
WINDS WILL TEND TO BECOME LIGHT AND VARIABLE TONIGHT AS THE
NOCTURNAL INVERSION SETS UP...DECOUPLING THE BOUNDARY LAYER FROM
THE WEAK PRESSURE GRADIENT INDUCED WINDS ACROSS THE REGION. THIS
WILL SET UP AN IDEAL ENVIRONMENT FOR RADIATIONAL COOLING TONIGHT
INTO TOMORROW MORNING. NAM...RAP...AND HRRR FORECAST SOUNDINGS ALL
SEEM TO CAPTURE THIS ENVIRONMENT WELL...AND ADVERTISE A GOOD
CHANCE OF RADIATIONAL FOG DEVELOPMENT TONIGHT. WENT AHEAD AND
PLACED 1-2 SM VISIBILITY RESTRICTIONS IN ALL AREA TAFS FROM 10 TO
15Z TOMORROW MORNING AS A RESULT.
THE UPS RADIATIONAL FOG FORECAST/DETECTION METHOD STRONGLY
SUPPORTS FOG DEVELOPMENT TONIGHT. ONCE WE SEE HOW DEW POINTS
RESPOND AFTER CLOUDS DISSIPATE THIS AFTERNOON...MAY HAVE TO REDUCE
VISIBILITIES FURTHER IF THE CROSS OVER TEMPERATURE (THE
TEMPERATURE DURING THE PEAK HEATING PERIOD OF THE DAY) IS AS HIGH
AS MODELS ARE ADVERTISING. CAVANAUGH
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 42 66 44 63 48 / 0 0 5 5 5
WACO, TX 39 65 42 64 48 / 0 0 5 5 10
PARIS, TX 40 64 38 57 41 / 0 0 5 5 5
DENTON, TX 39 64 41 62 47 / 0 0 5 5 10
MCKINNEY, TX 38 64 40 61 45 / 0 0 5 5 5
DALLAS, TX 43 65 44 62 48 / 0 0 5 5 5
TERRELL, TX 41 66 42 61 45 / 0 0 5 5 5
CORSICANA, TX 42 67 43 63 46 / 0 0 5 5 5
TEMPLE, TX 41 67 44 64 49 / 0 0 5 5 10
MINERAL WELLS, TX 39 65 42 64 49 / 0 0 5 5 20
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/75
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
1234 PM CST MON DEC 8 2014
.AVIATION...
FOR THE 18Z TAFS...THE SHORT TERM FORECAST FOR MVFR STRATUS AND
THEN FOG POTENTIAL OVERNIGHT ARE THE PRIMARY AVIATION WEATHER
CONCERNS.
17Z AIRCRAFT SOUNDINGS SHOWED A SATURATED LAYER JUST A FEW HUNDRED
FEET THICK WITHIN THE MVFR STRATUS DECK IN PLACE OVER THE DFW
AREA. THE ONLY REASON THE CLOUDS HAVE BEEN HANGING AROUND SO LONG
WITHIN THIS THIN LAYER OF SATURATION IS BECAUSE THESE CLOUDS WERE
FOUND WITHIN A STEEP TEMPERATURE INVERSION. THIS INVERSION IS VERY
STABLE...AND AS A RESULT IS DAMPENING VERTICAL MOTIONS/MIXING THAT
WOULD HAVE OTHERWISE MIXED DRY AIR THROUGH THIS LAYER OF CLOUDS BY
NOW. AT ANY RATE...THESE CLOUDS ARE STILL EXPECTED TO MIX OUT THIS
AFTERNOON...AND VISIBLE SATELLITE IMAGERY SHOWS THAT THIS IS
FINALLY STARTING TO TAKE PLACE. EXPECT THAT MOST DFW AREA SITES
WILL SEE STRATUS SCATTER OUT AROUND 19Z...BECOMING CLEAR AT THE
LOW-LEVELS AFTER 21Z.
LATE MORNING SURFACE ANALYSIS INDICATED THAT A BROAD RIDGE OF HIGH
PRESSURE WAS IN PLACE ACROSS THE SOUTHERN PLAINS. THIS WILL KEEP
WINDS LIGHT AND NORTHERLY OVER ALL AREA TAF SITES THROUGH SUNSET.
WINDS WILL TEND TO BECOME LIGHT AND VARIABLE TONIGHT AS THE
NOCTURNAL INVERSION SETS UP...DECOUPLING THE BOUNDARY LAYER FROM
THE WEAK PRESSURE GRADIENT INDUCED WINDS ACROSS THE REGION. THIS
WILL SET UP AN IDEAL ENVIRONMENT FOR RADIATIONAL COOLING TONIGHT
INTO TOMORROW MORNING. NAM...RAP...AND HRRR FORECAST SOUNDINGS ALL
SEEM TO CAPTURE THIS ENVIRONMENT WELL...AND ADVERTISE A GOOD
CHANCE OF RADIATIONAL FOG DEVELOPMENT TONIGHT. WENT AHEAD AND
PLACED 1-2 SM VISIBILITY RESTRICTIONS IN ALL AREA TAFS FROM 10 TO
15Z TOMORROW MORNING AS A RESULT.
THE UPS RADIATIONAL FOG FORECAST/DETECTION METHOD STRONGLY
SUPPORTS FOG DEVELOPMENT TONIGHT. ONCE WE SEE HOW DEW POINTS
RESPOND AFTER CLOUDS DISSIPATE THIS AFTERNOON...MAY HAVE TO REDUCE
VISIBILITIES FURTHER IF THE CROSS OVER TEMPERATURE (THE
TEMPERATURE DURING THE PEAK HEATING PERIOD OF THE DAY) IS AS HIGH
AS MODELS ARE ADVERTISING.
CAVANAUGH
&&
.UPDATE...
WILL BE ISSUING A QUICK MIDDAY UPDATE TO EXTEND THE CLOUD
COVER INTO THE EARLY TO MID AFTERNOON ALONG AND WEST OF THE
I-35/I-35W CORRIDOR AND NORTHEAST OF THE METROPLEX. THESE CLOUDS
WILL ALSO AFFECT EARLY AFTERNOON WARMING AND RESULTING HIGHS. ITS
POSSIBLE THAT AREAS ALONG THE RED RIVER AND NORTHWEST OF FORT
WORTH MIGHT REMAIN UNDER THICK CLOUDS UNTIL LATE AFTERNOON OR
SUNSET. THE EARLY MORNING DENSE FOG AROUND COMANCHE AND
STEPHENVILLE HAS THINNED WITH VISIBILITY BETTER THAN 2 MILES AT
11 AM. 75
&&
.PREV DISCUSSION... /ISSUED 333 AM CST MON DEC 8 2014/
MID AND HIGH LEVEL CLOUDS ASSOCIATED WITH AN UPPER LEVEL TROUGH
ARE EXITING TO THE EAST OF THE REGION AS THE SYSTEM HEADS FOR THE
MISSISSIPPI VALLEY. CLOSER TO THE SURFACE...SHALLOW MOISTURE
CONTINUES TO LINGER OVER NORTH TEXAS...LEADING TO THE DEVELOPMENT
OF LOW CLOUDS AND FOG AS TEMPERATURES FALL INTO THE 40S /WITH A
FEW UPPER 30S/. FOG HAS REMAINED PATCHY IN NATURE THUS FAR..BUT WE
HAVE SEEN A FEW SPOTS DROP BELOW A MILE VISIBILITY. WE WILL KEEP
AN EYE ON SURFACE OBSERVATIONS AND IF SIGNIFICANT VISIBILITY
REDUCTIONS BECOME MORE WIDESPREAD...A DENSE FOG ADVISORY COULD BE
CONSIDERED LATER IN THE MORNING.
CLOUDS WILL SCATTER AND FOG WILL DISSIPATE AROUND MID DAY AS
TEMPERATURES CLIMB INTO THE 50S AND 60S. LIGHT WINDS ASSOCIATED
WITH A SURFACE RIDGE OVERHEAD WILL LEAD TO GOOD RADIATIVE COOLING
AND POTENTIALLY MORE FOG DEVELOPMENT AGAIN LATE TONIGHT/TUESDAY
MORNING. HIGH RESOLUTION MODEL DATA HAS ALREADY PICKED UP ON THIS
AND WE HAVE SUBSEQUENTLY ADDED PATCHY FOG TO THE LATE
TONIGHT/TOMORROW MORNING PERIOD.
DRY NORTHWEST FLOW ALOFT WILL BE IN PLACE TODAY AS THE TROUGH
DEEPENS EAST OF THE REGION AND A RIDGE AMPLIFIES TO OUR WEST. THE
RIDGE WILL BUILD IN FROM THE WEST TOMORROW...WHICH SHOULD LEAD TO
GOOD SURFACE HEATING AND HIGHS IN THE MID 60S TUESDAY. SOUTHEAST
WINDS OF 5 TO 10 MPH WILL DEVELOP TUESDAY NIGHT AS THE SURFACE RIDGE
SHIFTS TO OUR EAST. THIS WILL LEAD TO SOME LOW CLOUD COVER WEDNESDAY
MORNING AS STRATUS DEVELOPS TO OUR SOUTH AND SPREADS NORTHWARD...BUT
THE WIND SPEEDS SHOULD HOPEFULLY KEEP VISIBILITIES IN CHECK.
A SOUTHERN STREAM SHORTWAVE CURRENTLY WEST OF BAJA CALIFORNIA
WILL APPROACH FROM THE WEST ON WEDNESDAY AND CROSS NORTH TEXAS
THURSDAY. LEE SURFACE TROUGHING WILL DEEPEN A LITTLE IN RESPONSE
TO THE DISTURBANCE...AND SOUTHERLY LOW LEVEL FLOW WILL INCREASE
TO 15-20 MPH. THIS SHOULD GENERATE ENOUGH UPGLIDE TO PRODUCE SOME
LIGHT SHOWERS WEDNESDAY NIGHT AND THURSDAY. IT APPEARS THAT
COVERAGE OF MEASURABLE PRECIPITATION WOULD REMAIN LOW AND WE HAVE
KEPT POPS AT SLIGHT CHANCE.
CONFIDENCE IS INCREASING THAT MUCH BETTER RAIN CHANCES WILL OCCUR
LATE IN THE WEEKEND INTO EARLY NEXT WEEK...AS MEDIUM RANGE MODEL DATA
CONTINUES TO INDICATE A POTENT UPPER TROUGH DEEPENING INTO A CUT-
OFF LOW OVER THE SOUTHERN PLAINS. THE SYSTEM SHOULD HAVE
SUFFICIENT TIME TO TAP INTO GULF MOISTURE AS RETURN FLOW PERSISTS
THURSDAY THROUGH THE WEEKEND. AT THIS TIME...THE BEST RAIN CHANCES
WOULD BEGIN SUNDAY AS LIFT FROM THE SYSTEM SPREADS
OVERHEAD...GENERATING SCATTERED SHOWERS AND THUNDERSTORMS. THE
DURATION OF THE CONVECTION WILL DEPEND ON THE EXACT TRACK OF THE
SYSTEM...BUT AT THIS TIME IS LOOKS LIKES WE WILL HAVE A DAY OR TWO
TO BENEFIT FROM SOME MUCH NEEDED RAINFALL CENTERED AROUND OUR DAY
7 FORECAST PERIOD.
30
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 42 66 44 63 46 / 0 0 5 5 5
WACO, TX 39 65 42 64 46 / 0 0 5 5 10
PARIS, TX 40 64 38 57 39 / 0 0 5 5 5
DENTON, TX 38 65 40 62 45 / 0 0 5 5 10
MCKINNEY, TX 38 64 39 61 43 / 0 0 5 5 5
DALLAS, TX 43 65 45 62 46 / 0 0 5 5 5
TERRELL, TX 41 66 41 61 43 / 0 0 5 5 5
CORSICANA, TX 42 67 44 63 44 / 0 0 5 5 5
TEMPLE, TX 41 67 43 64 47 / 0 0 5 5 10
MINERAL WELLS, TX 39 65 40 64 47 / 0 0 5 5 20
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/